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http://docs.lucedaphotonics.com/examples/plot_gdsii_import.html | # Creating a Cell from an Existing GDSII file¶
This sample illustrates how to import an existing GDSII file into a PCell, and assign ports and a circuit model to it.
There are cases when you want to integrate an existing old design into a new Ipkiss design, but where only the GDSII output is available. Ipkiss can wrap this GDSII file into an Ipkiss cell, and then you can manually add the ports, netlist and model so you can use it into a larger circuit.
Note that all the layers used in the GDSII must first be defined in the Technology file. This may not always be the case. (see example Creating a Cell from an Existing GDSII file with a new Technology).
Importing from GDSII
Illustrates
1. Write a Cell to a GDSII file
2. Import a GDSII file into an IPKISS component
3. Assign a CircuitModel to the imported component
## Export a grating coupler to GDSII¶
We first write a fiber coupler to gdsii so we can import it again later. Note that all the layers used in the gdsii must be defined in the technology file.
In this example we will use technologies.silicon_photonics, which is an example TECH shipped with IPKISS.
from technologies import silicon_photonics
from ipkiss3 import all as i3
import numpy as np
import pylab as plt
Then, we instantiate a grating coupler, and write it to my_grating.gds:
from picazzo3.fibcoup.curved.cell import FiberCouplerCurvedGrating # Here we use a fiber_coupler from Picazzo
my_grating = FiberCouplerCurvedGrating(name="unique_grating_name_used_in_GDSII") # We give a unique name to the cell that will be used in the gdsii file.
my_grating_layout = my_grating.Layout()
my_grating_layout_ports = my_grating_layout.ports
my_grating_layout.visualize()
my_grating_layout.write_gdsii("my_grating.gds")
We now define a grating coupler simulation model. It is a simple gaussian model with a fixed reflection parameter (which is useful to model light that reflects back and forth in the circuit because of the grating coupler).
class GratingModel(i3.CompactModel):
parameters = [
'bandwidth_3dB',
'peak_transmission',
'center_wavelength',
'reflection'
]
terms = [
i3.OpticalTerm(name='in'),
i3.OpticalTerm(name='vertical_in'),
]
def calculate_smatrix(parameters, env, S):
sigma = parameters.bandwidth_3dB / 2.35482 # fwhm => sigma
power_S = parameters.peak_transmission * np.exp(-(env.wavelength - parameters.center_wavelength)**2.0 / (2.0 * (sigma**2.0)))
S['vertical_in', 'in'] = S['in', 'vertical_in'] = np.sqrt(power_S)
S['in', 'in'] = parameters.reflection
## Importing the GDSII file¶
We use i3.GDSCell to import the GDSII file. In addition, we also
• Assign it ports
• Assign it a simulation model based on GratingModel that we defined in the code above.
class ImportedGrating(i3.GDSCell):
def _default_filename(self):
return 'my_grating.gds' # path to the gdsii file that contains the cell to be imported
def _default_cell_name(self):
return 'unique_grating_name_used_in_GDSII' # name of the cell to be imported inside the gdsii file.
class Layout(i3.GDSCell.Layout):
def _generate_ports(self, ports):
ports += i3.OpticalPort(name='in', position=(20.0, 0.0), angle=0.0) # We have to manually set the ports as this info is not in the gdsii file yet
ports += i3.VerticalOpticalPort(name="vertical_in",
position=(0.0,0.0),
inclination=90.0,
angle=0.0) # For the fiber a vertical port is used.
return ports
# Here we use our compact model. The netlist is automatically inferred from the layout.
class CircuitModel(i3.CircuitModelView):
center_wavelength = i3.PositiveNumberProperty(default=1.55, doc="center wavelength [um]")
bandwidth_3dB = i3.PositiveNumberProperty(default=0.060, doc="3dB bandwidth [um]")
peak_transmission = i3.NonNegativeNumberProperty(default=1.0, doc="peak transmission (0 to 1)")
reflection = i3.ComplexFractionProperty(default=0.0, doc="Complex reflection back into the waveguide")
def _generate_model(self):
return GratingModel(center_wavelength=self.center_wavelength,
bandwidth_3dB=self.bandwidth_3dB,
peak_transmission=self.peak_transmission,
reflection=self.reflection)
Instantiate the imported cell with its Layout view
im_cell = ImportedGrating()
im_layout = im_cell.Layout()
im_layout.visualize()
Instantiate the CircuitModel view and do a simulation
wavelengths = np.arange(1.5, 1.6, 0.001)
im_caphemodel = im_cell.CircuitModel(bandwidth_3dB=0.1, peak_transmission=0.6)
S = im_caphemodel.get_smatrix(wavelengths=wavelengths)
plt.figure()
plt.plot(wavelengths, np.abs(S['in', 'vertical_in'])**2)
plt.show() | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.45787712931632996, "perplexity": 8591.364332774296}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141189038.24/warc/CC-MAIN-20201127015426-20201127045426-00506.warc.gz"} |
http://export.arxiv.org/list/gr-qc/1106?300 | # General Relativity and Quantum Cosmology
## Authors and titles for Jun 2011
[ total of 370 entries: 1-25 | 26-50 | 51-75 | 76-100 | ... | 351-370 ]
[ showing 25 entries per page: fewer | more | all ]
[1]
Title: A new approach in stability analysis: case study: tachyon cosmology with non-minimally coupled scalar field-matter
Comments: 21 pages, 30 figures; accepted for publication in Phys. Rev. D
Journal-ref: Phys.Rev.D83:124042,2011
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[2]
Title: $f(T)$ Theories and Varying Fine Structure Constant
Comments: 12 pages, 4 figures, 1 table, revtex4; v2: discussions added, Phys. Lett. B in press; v3: published version
Journal-ref: Phys.Lett.B703:74-80,2011
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
[3]
Title: OSS (Outer Solar System): A fundamental and planetary physics mission to Neptune, Triton and the Kuiper Belt
Comments: 43 pages, 10 figures, Accepted to Experimental Astronomy, Special Issue Cosmic Vision. Revision according to reviewers comments
Journal-ref: Experimental Astronomy 34:2 (2012) 203-242
Subjects: General Relativity and Quantum Cosmology (gr-qc); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Detectors (physics.ins-det)
[4]
Title: R^n gravity and the chameleon
Authors: Valerio Faraoni (Bishop's University)
Comments: 5 pages, latex, 1 figure, to appear in Phys. Rev. D
Journal-ref: Phys.Rev.D83:124044,2011
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[5]
Title: Type III and N solutions to quadratic gravity
Journal-ref: Phys.Rev.D84:024047,2011
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
[6]
Title: Systematic solution-generation of five-dimensional black holes
Comments: Invited review for Prog. Theor. Phys. Suppl., 33 pages, 13 figures. v2: References added v3: published version
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
[7]
Title: On the Meaning of the Principle of General Covariance
Authors: Alberto Chamorro
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[8]
Title: Dust in the York Canonical Basis of ADM Tetrad Gravity: the Problem of Vorticity
Authors: David Alba, Luca Lusanna (INFN, Firenze)
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
[9]
Title: Dirac spinors in Bianchi-I f(R)-cosmology with torsion
Journal-ref: J. Math. Phys. 52, 112502 (2011)
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[10]
Title: Intrinsic and extrinsic geometries of a tidally deformed black hole
Journal-ref: Class. Quantum Grav. 28 175006, 2011
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[11]
Title: Hawking radiation via Landauer transport model
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[12]
Title: Landauer transport model for Hawking radiation from a Reissner-Nordstrom black hole
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[13]
Title: Hawking radiation from a BTZ black hole viewed as Landauer transport
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[14]
Title: Relativistic Cosmological Perturbation Theory and the Evolution of Small-Scale Inhomogeneities
Authors: P.G.Miedema
Comments: 37 pages including Maxima CAS files and R file. Textual improvements. Section VI on the standard Newtonian perturbation equation rewritten. Conclusions unchanged. Any comments, reviews, critiques, or objections are invited and should be send to the author by e-mail
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[15]
Title: Could the real (not virtual) static observer exist outside a Schwarzschild black hole?
Authors: Victor Berezin
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[16]
Title: Poincaré Gauge Theory With Coupled Even And Odd Parity Dynamic Spin-0 Modes: Dynamic Equations For Isotropic Bianchi Cosmologies
Journal-ref: Int. J. Mod. Phys. D 20, 2125 (2011)
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[17]
Title: Black Hole Entropy and the Modified Uncertainty Principle: A heuristic analysis
Authors: Barun Majumder
Comments: 8 pages, accepted for publication in Physics Letters B
Journal-ref: Phys. Lett. B 703 (2011) 402-405
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
[18]
Title: Highly covariant quantum lattice gas model of the Dirac equation
Authors: Jeffrey Yepez
Comments: 5 pages, 2 figures; 66 ABW review on 01 Dec 2010: Ref. No. RVB10.015-198, Case No. 66ABW-2010-1430
Subjects: General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)
[19]
Title: New Generic Ringdown Frequencies at the Birth of a Kerr Black Hole
Comments: 17 pages, 8 figures. Numerical analysis corrected, references added; reflects published version
Journal-ref: Phys. Rev. D 84, 084012 (2011)
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[20]
Title: Accretion processes in magnetically and tidally perturbed Schwarzschild black holes
Comments: to be published in Phys. Rev. D, 13 pages, 7 figures, 1 table
Journal-ref: Phys.Rev.D84:024018,2011
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[21]
Title: Background-Independence
Authors: Gordon Belot
Comments: Forthcoming in General Relativity and Gravitation
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[22]
Title: The Graviton Propagator in de Donder Gauge on de Sitter Background
Comments: 39 pages, no figures, uses LaTeX2e
Journal-ref: J.Math.Phys.52:122301,2011
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
[23]
Title: Comment on `Spinning loop black holes' [arXiv:1006.0232]
Journal-ref: Class. Quantum Grav. 28 (2011) 148001 (2pp)
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[24]
Title: Inspiral-merger-ringdown multipolar waveforms of nonspinning black-hole binaries using the effective-one-body formalism
Comments: 26 pages, 25 figures, published Phys. Rev. D version
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[25]
Title: Towards Loop Quantum Supergravity (LQSG)
Comments: 9 pages. v2: minor improvements in presentation, virtually identical to published version
Journal-ref: Phys. Lett. B 711: 205-211 (2012)
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)
[ total of 370 entries: 1-25 | 26-50 | 51-75 | 76-100 | ... | 351-370 ]
[ showing 25 entries per page: fewer | more | all ]
Disable MathJax (What is MathJax?) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.16953927278518677, "perplexity": 7780.626257398106}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-18/segments/1555578602767.67/warc/CC-MAIN-20190423114901-20190423140901-00456.warc.gz"} |
http://mathhelpforum.com/advanced-algebra/122662-dimension.html | # Math Help - dimension
1. ## dimension
hello
what's the dimension of the subspace $F$ of $\mathfrak{F}(\mathbb{R},\mathbb{R})$ spanned by $f_1(x)=\sin^2(x),f_2(x)=\cos^2(x),f_3(x)=\sin(2x)$ and $f_4(x)=\cos(2x)$
thanks.
2. Originally Posted by Raoh
hello
what's the dimension of the subspace $F$ of $\mathfrak{F}(\mathbb{R},\mathbb{R})$ spanned by $f_1(x)=\sin^2(x),f_2(x)=\cos^2(x),f_3(x)=\sin(2x)$ and $f_4(x)=\cos(2x)$
thanks.
you should explain very clearly what your vector space is. just using a non-standard and weird notation such as $\mathfrak{F}(\mathbb{R},\mathbb{R})$ is not good enough. i guess your vector space is the $\mathbb{R}$-vector space of
all real-valued functions defined on $\mathbb{R}$. then $\dim_{\mathbb{R}}F=2$ and $\{\sin^2 x, \sin (2x) \}$ is a basis for $F.$
Edit: i meant $\dim_{\mathbb{R}} F=3$ and $\{1,\sin^2x, \sin(2x) \}$ is a basis for $F.$ sorry for the mistake.
3. Originally Posted by NonCommAlg
you should explain very clearly what your vector space is. just using a non-standard and weird notation such as $\mathfrak{F}(\mathbb{R},\mathbb{R})$ is not good enough. i guess your vector space is the $\mathbb{R}$-vector space of
all real-valued functions defined on $\mathbb{R}$. then $\dim_{\mathbb{R}}F=2$ and $\{\sin^2 x, \sin (2x) \}$ is a basis for $F.$
your guess was right,anyway would you show me how you got that basis.
thank you.
4. Originally Posted by NonCommAlg
you should explain very clearly what your vector space is. just using a non-standard and weird notation such as $\mathfrak{F}(\mathbb{R},\mathbb{R})$ is not good enough. i guess your vector space is the $\mathbb{R}$-vector space of
all real-valued functions defined on $\mathbb{R}$. then $\dim_{\mathbb{R}}F=2$ and $\{\sin^2 x, \sin (2x) \}$ is a basis for $F.$
I don't think this is right since assume there exist $a,b \in \mathbb{R}$ such that $\cos ^2 (x)= a\sin (2x) + b\sin ^2 (x)=2a \sin (x) \cos (x) + b\sin ^2 (x)$ then evaluation in $0$ gives $1=0$. Thus $A= \{ \sin ^2 (x), \cos ^2 (x) , \sin (2x) \}$ is l.i. and since $\cos ^2 (x) - \sin ^2 (x) = \cos (2x)$ we get that $A$ is a basis for $F$.
5. Originally Posted by Jose27
I don't think this is right since assume there exist $a,b \in \mathbb{R}$ such that $\cos ^2 (x)= a\sin (2x) + b\sin ^2 (x)=2a \sin (x) \cos (x) + b\sin ^2 (x)$ then evaluation in $0$ gives $1=0$. Thus $A= \{ \sin ^2 (x), \cos ^2 (x) , \sin (2x) \}$ is l.i. and since $\cos ^2 (x) - \sin ^2 (x) = \cos (2x)$ we get that $A$ is a basis for $F$.
hi "Jose27" would you please explain the method you used to find that basis.
thanks.
6. Assume $\sin ^2(x) = a \sin (2x)$ for some $a\in \mathbb{R}$ then evaluation in $\frac{\pi }{2}$ will give $1=0$ so these two functions are l.i. Then by my previous post we get that $\cos ^2 (x) \notin span \{ \sin ^2 (x), \sin (2x) \}$ so it must be that these three are l.i. but again by my previous post $\cos (2x) \in span(A)$ so $A$ is a basis for $F$.
7. Originally Posted by Jose27
Assume $\sin ^2(x) = a \sin (2x)$ for some $a\in \mathbb{R}$ then evaluation in $\frac{\pi }{2}$ will give $1=0$ so these two functions are l.i. Then by my previous post we get that $\cos ^2 (x) \notin span \{ \sin ^2 (x), \sin (2x) \}$ so it must be that these three are l.i. but again by my previous post $\cos (2x) \in span(A)$ so $A$ is a basis for $F$.
one final question
what is the first step to do to answer this kind of questions ?
thanks "Jose27"
8. I guess trying to determine if they're l.i. To do this pick one vector then add another, see if it's l.i then add another etc.
9. Originally Posted by Jose27
I guess trying to determine if they're l.i. To do this pick one vector then add another, see if it's l.i then add another etc.
Got that,thanks "Jose27"
10. Originally Posted by Jose27
I don't think this is right since assume there exist $a,b \in \mathbb{R}$ such that $\cos ^2 (x)= a\sin (2x) + b\sin ^2 (x)=2a \sin (x) \cos (x) + b\sin ^2 (x)$ then evaluation in $0$ gives $1=0$. Thus $A= \{ \sin ^2 (x), \cos ^2 (x) , \sin (2x) \}$ is l.i. and since $\cos ^2 (x) - \sin ^2 (x) = \cos (2x)$ we get that $A$ is a basis for $F$.
i actually had $\{1,\sin^2x, \sin(2x) \}$ in my mind but i wrote something else. thanks for noticing that. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 70, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9952516555786133, "perplexity": 174.70958709725707}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-41/segments/1410657104131.95/warc/CC-MAIN-20140914011144-00274-ip-10-196-40-205.us-west-1.compute.internal.warc.gz"} |
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Advances in Difference EquationsJournal Prestige (SJR): 0.539 Citation Impact (citeScore): 1Number of Followers: 3 Open Access journal ISSN (Print) 1687-1839 - ISSN (Online) 1687-1847 Published by SpringerOpen [226 journals]
• On ideal convergence Fibonacci difference sequence spaces
• Abstract: The Fibonacci sequence was firstly used in the theory of sequence spaces by Kara and Başarir (Casp. J. Math. Sci. 1(1):43–47, 2012). Afterward, Kara (J. Inequal. Appl. 2013(1):38, 2013) defined the Fibonacci difference matrix F̂ by using the Fibonacci sequence $$(f_{n})$$ for $$n\in{\{0, 1, \ldots\}}$$ and introduced new sequence spaces related to the matrix domain of F̂. In this paper, by using the Fibonacci difference matrix F̂ defined by the Fibonacci sequence and the notion of ideal convergence, we introduce the Fibonacci difference sequence spaces $$c^{I}_{0}(\hat {F})$$ , $$c^{I}(\hat{F})$$ , and $$\ell^{I}_{\infty}(\hat{F})$$ . Further, we study some inclusion relations concerning these spaces. In addition, we discuss some properties on these spaces such as monotonicity and solidity.
PubDate: 2018-05-25
• Dynamical analysis of a ratio-dependent predator–prey model with Holling
III type functional response and nonlinear harvesting in a random
environment
• Abstract: The objective of this paper is to study the dynamics of the stochastic ratio-dependent predator–prey model with Holling III type functional response and nonlinear harvesting. For the autonomous system, sufficient conditions for globally positive solution and stochastic permanence are established. Then, applying comparison theorem for stochastic differential equation, sufficient conditions for extinction and persistence in the mean are obtained. In addition, we prove that there exists a unique stationary distribution and it has ergodicity under certain parametric restrictions. For the periodic system, we obtain conditions for the existence of a nontrivial positive periodic solution. Finally, numerical simulations are carried out to substantiate the analytical results.
PubDate: 2018-05-24
• Allee effect increasing the final density of the species subject to the
Allee effect in a Lotka–Volterra commensal symbiosis model
• Abstract: A Lotka–Volterra commensal symbiosis model with first species subject to the Allee effect is proposed and studied in this paper. Local and global stability property of the equilibria are investigated. An amazing finding is that with increasing Allee effect, the final density of the species subject to the Allee effect is also increased. Such a phenomenon is different from the known results, and it is the first time to be observed. Numeric simulations are carried out to show the feasibility of the main results.
PubDate: 2018-05-22
• Meromorphic functions that share a polynomial with their difference
operators
• Abstract: In this paper, we prove the following result: Let f be a nonconstant meromorphic function of finite order, p be a nonconstant polynomial, and c be a nonzero constant. If f, $$\Delta _{c}f$$ , and $$\Delta_{c}^{n}f$$ ( $$n\ge 2$$ ) share ∞ and p CM, then $$f\equiv \Delta_{c}f$$ . Our result provides a difference analogue of the result of Chang and Fang in 2004 (Complex Var. Theory Appl. 49(12):871–895, 2004).
PubDate: 2018-05-22
• A fractional Fourier integral operator and its extension to classes of
function spaces
• Abstract: In this paper, an attempt is being made to investigate a class of fractional Fourier integral operators on classes of function spaces known as ultraBoehmians. We introduce a convolution product and establish a convolution theorem as a product of different functions. By employing the convolution theorem and making use of an appropriate class of approximating identities, we provide necessary axioms and define function spaces where the fractional Fourier integral operator is an isomorphism connecting the different spaces. Further, we provide an inversion formula and obtain various properties of the cited integral in the generalized sense.
PubDate: 2018-05-22
• Weak order in averaging principle for stochastic differential equations
with jumps
• Abstract: In this paper, we deal with the averaging principle for a two-time-scale system of jump-diffusion stochastic differential equations. Under suitable conditions, we expand the weak error in powers of timescale parameter. We prove that the rate of weak convergence to the averaged dynamics is of order 1. This reveals that the rate of weak convergence is essentially twice that of strong convergence.
PubDate: 2018-05-22
• New results on positive almost periodic solutions for first-order neutral
differential equations
• Abstract: In this paper, a class of first-order neutral differential equations with time-varying delays and coefficients is considered. Some results on the existence of positive almost periodic solutions for the equations are obtained by using the contracting mapping principle and the differential inequality technique. In addition, an example is given to illustrate our results.
PubDate: 2018-05-21
• Oscillation results for a fractional order dynamic equation on time scales
with conformable fractional derivative
• Abstract: In this paper, we investigate oscillatory and asymptotic properties for a class of fractional order dynamic equations on time scales, where the fractional derivative is defined in the sense of the conformable fractional derivative. Based on the properties of conformable fractional differential and integral, some new oscillatory and asymptotic criteria are established. Applications of the established results show that they can be used to research oscillation for fractional order equations in various time scales such as fractional order differential equations, fractional order difference equations, and so on.
PubDate: 2018-05-21
• Stability analysis of a single species logistic model with Allee effect
and feedback control
• Abstract: A single species logistic model with Allee effect and feedback control \begin{aligned}& \frac{dx}{dt} = rx(1-x)\frac{x}{\beta+x}-axu, \\& \frac{du}{dt} = -bu+cx, \end{aligned} where β, r, a, b, and c are all positive constants, is for the first time proposed and studied in this paper. We show that, for the system without Allee effect, the system admits a unique positive equilibrium which is globally attractive. However, for the system with Allee effect, if the Allee effect is limited ( $$\beta<\frac{b^{2}r^{2}}{ac(ac+br)}$$ ), then the system could admit a unique positive equilibrium which is locally asymptotically stable; if the Allee effect is too large ( $$\beta>\frac{br}{ac}$$ ), the system has no positive equilibrium, which means the extinction of the species. The Allee effect reduces the population density of the species, which increases the extinction property of the species. The Allee effect makes the system “unstable” in the sense that the system could collapse under large perturbation. Numeric simulations are carried out to show the feasibility of the main results.
PubDate: 2018-05-18
• Dynamic behaviors of a nonlinear amensalism model
• Abstract: A nonlinear amensalism model of the form \begin{aligned} &\frac{dN_{1}}{dt}= r_{1}N_{1} \biggl(1- \biggl( \frac{N_{1}}{P_{1}} \biggr)^{\alpha _{1}}-u \biggl(\frac{N_{2}}{P_{1}} \biggr)^{\alpha_{2}} \biggr), \\ &\frac{dN_{2}}{dt}= r_{2}N_{2} \biggl(1- \biggl( \frac{N_{2}}{P_{2}} \biggr)^{\alpha_{3}} \biggr), \end{aligned} where $$r_{i}, P_{i}, u, i=1, 2, \alpha_{1}, \alpha_{2}, \alpha_{3}$$ are all positive constants, is proposed and studied in this paper. The dynamic behaviors of the system are determined by the sign of the term $$1-u (\frac{P_{2}}{P_{1}} )^{\alpha_{2}}$$ . If $$1-u (\frac {P_{2}}{P_{1}} )^{\alpha_{2}}>0$$ , then the unique positive equilibrium $$D(N_{1}^{*},N_{2}^{*})$$ is globally attractive, if $$1-u (\frac{P_{2}}{P_{1}} )^{\alpha_{2}}<0$$ , then the boundary equilibrium $$C(0, P_{2})$$ is globally attractive. Our results supplement and complement the main results of Xiong, Wang, and Zhang (Advances in Applied Mathematics 5(2):255–261, 2016).
PubDate: 2018-05-18
• Design disturbance attenuating controller for memristive recurrent neural
networks with mixed time-varying delays
• Abstract: This paper investigates the design of disturbance attenuating controller for memristive recurrent neural networks (MRNNs) with mixed time-varying delays. By applying the combination of differential inclusions, set-valued maps and Lyapunov–Razumikhin, a feedback control law is obtained in the simple form of linear matrix inequality (LMI) to ensure disturbance attenuation of memristor-based neural networks. Finally, a numerical example is given to show the effectiveness of the proposed criteria.
PubDate: 2018-05-18
• Existence and attractivity of solutions for fractional difference
equations
• Abstract: In this paper, we study a kind of difference equations with Riemann–Liouville-like fractional difference. The results on existence and attractivity are obtained by using the Picard iteration method and Schauder’s fixed point theorem. Examples are provided to illustrate the main results.
PubDate: 2018-05-18
• Adaptive neural network synchronization for uncertain strick-feedback
chaotic systems subject to dead-zone input
• Abstract: In this paper, an adaptive neural network (NN) synchronization controller is designed for two identical strict-feedback chaotic systems (SFCSs) subject to dead-zone input. The dead-zone models together with the system uncertainties are approximated by NNs. The dynamic surface control (DSC) approach is applied in the synchronization controller design, and the traditional problem of “explosion of complexity” that usually occurs in the backstepping design can be avoided. The proposed synchronization method guarantees the synchronization errors tend to an arbitrarily small region. Finally, this paper presents two simulation examples to confirm the effectiveness and the robustness of the proposed control method.
PubDate: 2018-05-18
• Positive solutions of fractional differential equations involving the
Riemann–Stieltjes integral boundary condition
• Abstract: In this article, the following boundary value problem of fractional differential equation with Riemann–Stieltjes integral boundary condition $$\textstyle\begin{cases} D_{0+}^{\alpha}u(t)+\lambda f(t, u(t),u(t))=0, \quad0< t< 1, n-1< \alpha \leq n, \\ u^{(k)}(0)=0,\quad 0\leq k\leq n-2, \qquad u(1)= \int_{0}^{1}u(s)\,dA(s) \end{cases}$$ is studied, where $$n-1 < \alpha\le n$$ , $$\lambda>0$$ , $$D_{0+}^{\alpha}$$ is the Riemann–Liouville fractional derivative, A is a function of bounded variation, $$\int_{0}^{1}u(s)\,dA(s)$$ denotes the Riemann–Stieltjes integral of u with respect to A. By the use of fixed point theorem and the properties of mixed monotone operator theory, the existence and uniqueness of positive solutions for the problem are acquired. Some examples are presented to illustrate the main result.
PubDate: 2018-05-16
• Parisian ruin probability for Markov additive risk processes
• Abstract: In this paper, we consider a spectrally negative Markov additive risk process. Using the theory of Jordan chain, a compact formula of Parisian ruin probability is given. The formula depends only on the scale matrix of spectrally negative Markov additive risk processes and the transition rate matrix $$\Lambda^{q}$$ .
PubDate: 2018-05-16
• Monotone iterative method for two-point fractional boundary value problems
• Abstract: In this work, we deal with two-point Riemann–Liouville fractional boundary value problems. Firstly, we establish a new comparison principle. Then, we show the existence of extremal solutions for the two-point Riemann–Liouville fractional boundary value problems, using the method of upper and lower solutions. The performance of the approach is tested through a numerical example.
PubDate: 2018-05-16
• Positive solutions of higher-order Sturm–Liouville boundary value
problems with fully nonlinear terms
• Abstract: In this paper we consider the existence of positive solutions of nth-order Sturm–Liouville boundary value problems with fully nonlinear terms, in which the nonlinear term f involves all of the derivatives $$u',\ldots, u^{(n-1)}$$ of the unknown function u. Such cases are seldom investigated in the literature. We present some inequality conditions guaranteeing the existence of positive solutions. Our inequality conditions allow that $$f(t, x_{0}, x_{1},\ldots, x_{n-1})$$ is superlinear or sublinear growth on $$x_{0}, x_{1},\ldots, x_{n-1}$$ . Our discussion is based on the fixed point index theory in cones.
PubDate: 2018-05-16
• The effect of parameters on positive solutions and asymptotic behavior of
an unstirred chemostat model with B–D functional response
• Abstract: This paper deals with the effect of parameters on properties of positive solutions and asymptotic behavior of an unstirred chemostat model with the Beddington–DeAngelis (denote by B–D) functional response under the Robin boundary condition. Firstly, we establish some a priori estimates and a sufficient condition for the existence of positive solutions (see (Feng et al. in J. Inequal. Appl. 2016(1):294, 2016)). Secondly, we study the effect of the small parameter $$k_{1}$$ and sufficiently large $$k_{2}$$ in B–D functional response, which shows that the model has at least two positive solutions. Thirdly, we investigate the case of sufficiently large $$k_{1}$$ . The results show that if $$k_{1}$$ is sufficiently large, then the positive solution of this model is determined by a limiting equation. Finally, we present an asymptotic behavior of solutions depending on time. The main methods used in this paper include the fixed point index theory, bifurcation theory, perturbation technique, comparison principle, and persistence theorem.
PubDate: 2018-05-16
• Existence of positive solutions for two-point boundary value problems of
nonlinear fractional q -difference equation
• Abstract: This paper is concerned with the two-point boundary value problems of a nonlinear fractional q-difference equation with dependence on the first order q-derivative. We discuss some new properties of the Green function by using q-difference calculus. Furthermore, by means of Schauder’s fixed point theorem and an extension of Krasnoselskii’s fixed point theorem in a cone, the existence of one positive solution and of at least one positive solution for the boundary value problem is established.
PubDate: 2018-05-16
• Dynamical behaviors of a food-chain model with stage structure and time
delays
• Abstract: Incorporating two delays ( $$\tau_{1}$$ represents the maturity of predator, $$\tau_{2}$$ represents the maturity of top predator), we establish a novel delayed three-species food-chain model with stage structure in this paper. By analyzing the characteristic equations, constructing a suitable Lyapunov functional, using Lyapunov–LaSalle’s principle, the comparison theorem and iterative technique, we investigate the existence of nonnegative equilibria and their stability. Some interesting findings show that the delays have great impacts on dynamical behaviors for the system: on one hand, if $$\tau_{1}\in (m_{1},m_{2})$$ and $$\tau_{2}\in(m_{4}, +\infty)$$ , then the boundary equilibrium $$E_{2}(x^{0}, y_{1}^{0}, y_{2}^{0}, 0, 0)$$ is asymptotically stable (AS), i.e., the prey species and the predator species will coexist, the top-predator species will go extinct; on the other hand, if $$\tau_{1}\in(m_{2}, +\infty)$$ , then the axial equilibrium $$E_{1}(k, 0, 0, 0, 0)$$ is AS, i.e., all predators will go extinct. Numerical simulations are great well agreement with the theoretical results.
PubDate: 2018-05-16
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https://link.springer.com/article/10.1007%2Fs10623-018-0569-z | Designs, Codes and Cryptography
, Volume 87, Issue 7, pp 1673–1697
# Equiangular tight frames from group divisible designs
• Matthew Fickus
• John Jasper
Article
## Abstract
An equiangular tight frame (ETF) is a type of optimal packing of lines in a real or complex Hilbert space. In the complex case, the existence of an ETF of a given size remains an open problem in many cases. In this paper, we observe that many of the known constructions of ETFs are of one of two types. We further provide a new method for combining a given ETF of one of these two types with an appropriate group divisible design (GDD) in order to produce a larger ETF of the same type. By applying this method to known families of ETFs and GDDs, we obtain several new infinite families of ETFs. The real instances of these ETFs correspond to several new infinite families of strongly regular graphs. Our approach was inspired by a seminal paper of Davis and Jedwab which both unified and generalized McFarland and Spence difference sets. Our main result is a combinatorial analog of their algebraic results.
## Keywords
Equiangular tight frames Group divisible designs Strongly regular graphs
42C15
## Notes
### Acknowledgements
We thank the editors and the three anonymous reviewers for their comments, all of which were helpful. The views expressed in this article are those of the authors and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the United States Government. This work was partially supported by the Summer Faculty Fellowship Program of the United States Air Force Research Laboratory.
## References
1. 1.
Abel R.J.R., Greig M.: BIBDs with small block size. In: Colbourn C.J., Dinitz J.H. (eds.) Handbook of Combinatorial Designs, 2nd edn, pp. 72–79. CRC Press, Boca Raton (2007).Google Scholar
2. 2.
Abel R.J.R., Colbourn C.J., Dinitz J.H.: Mutually orthogonal Latin squares (MOLS). In: Colbourn C.J., Dinitz J.H. (eds.) Handbook of Combinatorial Designs, 2nd edn, pp. 160–193. CRC Press, Boca Raton (2007).Google Scholar
3. 3.
Azarija J., Marc T.: There is no (75,32,10,16) strongly regular graph. arXiv:1509.05933.
4. 4.
Azarija J., Marc T.: There is no (95,40,12,20) strongly regular graph. arXiv:1603.02032.
5. 5.
Bajwa W.U., Calderbank R., Mixon D.G.: Two are better than one: fundamental parameters of frame coherence. Appl. Comput. Harmon. Anal. 33, 58–78 (2012).
6. 6.
Bandeira A.S., Fickus M., Mixon D.G., Wong P.: The road to deterministic matrices with the Restricted Isometry Property. J. Fourier Anal. Appl. 19, 1123–1149 (2013).
7. 7.
Barg A., Glazyrin A., Okoudjou K.A., Yu W.-H.: Finite two-distance tight frames. Linear Algebra Appl. 475, 163–175 (2015).
8. 8.
Bodmann B.G., Elwood H.J.: Complex equiangular Parseval frames and Seidel matrices containing $$p$$th roots of unity. Proc. Am. Math. Soc. 138, 4387–4404 (2010).
9. 9.
Bodmann B.G., Paulsen V.I., Tomforde M.: Equiangular tight frames from complex Seidel matrices containing cube roots of unity. Linear Algebra Appl. 430, 396–417 (2009).
10. 10.
Bracken C., McGuire G., Ward H.: New quasi-symmetric designs constructed using mutually orthogonal Latin squares and Hadamard matrices. Des. Codes Cryptogr. 41, 195–198 (2006).
11. 11.
Brouwer A.E.: Strongly regular graphs. In: Colbourn C.J., Dinitz J.H. (eds.) Handbook of Combinatorial Designs, 2nd edn, pp. 852–868. CRC Press, Boca Raton (2007).Google Scholar
12. 12.
Brouwer A.E.: Parameters of strongly regular graphs. http://www.win.tue.nl/~aeb/graphs/srg/.
13. 13.
Chang K.I.: An existence theory for group divisible designs. Ph.D. Thesis, The Ohio State University (1976).Google Scholar
14. 14.
Chen Y.Q.: On the existence of abelian Hadamard difference sets and a new family of difference sets. Finite Fields Appl. 3, 234–256 (1997).
15. 15.
Corneil D., Mathon R. (eds.): Geometry and Combinatorics: Selected Works of J. J. Seidel. Academic Press, New York (1991).Google Scholar
16. 16.
Coutinho G., Godsil C., Shirazi H., Zhan H.: Equiangular lines and covers of the complete graph. Linear Algebra Appl. 488, 264–283 (2016).
17. 17.
Davis J.A., Jedwab J.: A unifying construction for difference sets. J. Comb. Theory Ser. A 80, 13–78 (1997).
18. 18.
Ding C., Feng T.: A generic construction of complex codebooks meeting the Welch bound. IEEE Trans. Inf. Theory 53, 4245–4250 (2007).
19. 19.
Fickus M., Mixon D.G.: Tables of the existence of equiangular tight frames. arXiv:1504.00253 (2016).
20. 20.
Fickus M., Mixon D.G., Tremain J.C.: Steiner equiangular tight frames. Linear Algebra Appl. 436, 1014–1027 (2012).
21. 21.
Fickus M., Mixon D.G., Jasper J.: Equiangular tight frames from hyperovals. IEEE Trans. Inf. Theory 62, 5225–5236 (2016).
22. 22.
Fickus M., Jasper J., Mixon D.G., Peterson J.D.: Tremain equiangular tight frames. J. Comb. Theory Ser. A 153, 54–66 (2018).
23. 23.
Fickus M., Jasper J., Mixon D.G., Peterson J.D.: Hadamard equiangular tight frames. arXiv:1703.05353.
24. 24.
Fickus M., Jasper J., Mixon D.G., Peterson J.D., Watson C.E.: Equiangular tight frames with centroidal symmetry. Appl. Comput. Harmon. Anal. (to appear).Google Scholar
25. 25.
Fickus M., Jasper J., Mixon D.G., Peterson J.D., Watson C.E.: Polyphase equiangular tight frames and abelian generalized quadrangles. Appl. Comput. Harmon. Anal. (to appear).Google Scholar
26. 26.
Fuchs C.A., Hoang M.C., Stacey B.C.: The SIC question: history and state of play. Axioms 6, 21 (2017).
27. 27.
Ge G.: Group divisible designs. In: Colbourn C.J., Dinitz J.H. (eds.) Handbook of Combinatorial Designs, 2nd edn, pp. 255–260. CRC Press, Boca Raton (2007).Google Scholar
28. 28.
Godsil C.D.: Krein covers of complete graphs. Aust. J. Comb. 6, 245–255 (1992).
29. 29.
Goethals J.M., Seidel J.J.: Strongly regular graphs derived from combinatorial designs. Can. J. Math. 22, 597–614 (1970).
30. 30.
Gordon D.: La Jolla covering repository. https://www.ccrwest.org/diffsets.html.
31. 31.
Grassl M., Scott A.J.: Fibonacci-Lucas SIC-POVMs. J. Math. Phys. 58, 122201 (2017).
32. 32.
Holmes R.B., Paulsen V.I.: Optimal frames for erasures. Linear Algebra Appl. 377, 31–51 (2004).
33. 33.
Iverson J.W., Jasper J., Mixon D.G.: Optimal line packings from nonabelian groups. arXiv:1609.09836.
34. 34.
Jasper J., Mixon D.G., Fickus M.: Kirkman equiangular tight frames and codes. IEEE Trans. Inf. Theory 60, 170–181 (2014).
35. 35.
Jungnickel D., Pott A., Smith K.W.: Difference sets. In: Colbourn C.J., Dinitz J.H. (eds.) Handbook of Combinatorial Designs, 2nd edn, pp. 419–435. CRC Press, Boca Raton (2007).Google Scholar
36. 36.
Lamken E.R., Wilson R.M.: Decompositions of edge-colored complete graphs. J. Comb. Theory Ser. A 89, 149–200 (2000).
37. 37.
Lemmens P.W.H., Seidel J.J.: Equiangular lines. J. Algebra 24, 494–512 (1973).
38. 38.
Mathon R., Rosa A.: $$2-(v, k,\lambda )$$ designs of small order. In: Colbourn C.J., Dinitz J.H. (eds.) Handbook of Combinatorial Designs, 2nd edn, pp. 25–58. CRC Press, Boca Raton (2007).Google Scholar
39. 39.
MacNeish H.F.: Euler squares. Ann. Math. 23, 221–227 (1922).
40. 40.
McFarland R.L.: A family of difference sets in non-cyclic groups. J. Comb. Theory Ser. A 15, 1–10 (1973).
41. 41.
McGuire G.: Quasi-symmetric designs and codes meeting the Grey-Rankin bound. J. Comb. Theory Ser. A 78, 280–291 (1997).
42. 42.
Mohácsy H.: The asymptotic existence of group divisible designs of large order with index one. J. Comb. Theory Ser. A 118, 1915–1924 (2011).
43. 43.
Renes J.M.: Equiangular tight frames from Paley tournaments. Linear Algebra Appl. 426, 497–501 (2007).
44. 44.
Renes J.M., Blume-Kohout R., Scott A.J., Caves C.M.: Symmetric informationally complete quantum measurements. J. Math. Phys. 45, 2171–2180 (2004).
45. 45.
Seidel J.J.: A survey of two-graphs. Coll. Int. Teorie Combin., Atti dei Convegni Lincei, vol. 17, pp. 481–511. Accademia Nazionale dei Lincei, Rome (1976).Google Scholar
46. 46.
Spence E.: A family of difference sets. J. Comb. Theory Ser. A 22, 103–106 (1977).
47. 47.
Strohmer T.: A note on equiangular tight frames. Linear Algebra Appl. 429, 326–330 (2008).
48. 48.
Strohmer T., Heath R.W.: Grassmannian frames with applications to coding and communication. Appl. Comput. Harmon. Anal. 14, 257–275 (2003).
49. 49.
Sustik M.A., Tropp J.A., Dhillon I.S., Heath R.W.: On the existence of equiangular tight frames. Linear Algebra Appl. 426, 619–635 (2007).
50. 50.
Szöllősi F.: All complex equiangular tight frames in dimension 3. arXiv:1402.6429.
51. 51.
Tropp J.A.: Complex equiangular tight frames. Proc. SPIE 5914, 591401/1–11 (2005).Google Scholar
52. 52.
Tropp J.A., Dhillon I.S., Heath Jr. R.W., Strohmer T.: Designing structured tight frames via an alternating projection method. IEEE Trans. Inf. Theory 51, 188–209 (2005).
53. 53.
Turyn R.J.: Character sums and difference sets. Pac. J. Math. 15, 319–346 (1965).
54. 54.
van Lint J.H., Seidel J.J.: Equilateral point sets in elliptic geometry. Indag. Math. 28, 335–348 (1966).
55. 55.
Waldron S.: On the construction of equiangular frames from graphs. Linear Algebra Appl. 431, 2228–2242 (2009).
56. 56.
Welch L.R.: Lower bounds on the maximum cross correlation of signals. IEEE Trans. Inf. Theory 20, 397–399 (1974).
57. 57.
Wilson R.M.: An existence theory for pairwise balanced designs I. Composition theorems and morphisms. J. Comb. Theory Ser. A 13, 220–245 (1972).
58. 58.
Xia P., Zhou S., Giannakis G.B.: Achieving the Welch bound with difference sets. IEEE Trans. Inf. Theory 51, 1900–1907 (2005).
59. 59.
Zauner G.: Quantum designs: foundations of a noncommutative design theory. Ph.D. Thesis, University of Vienna (1999).Google Scholar | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8222346305847168, "perplexity": 10452.76762001643}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027317339.12/warc/CC-MAIN-20190822172901-20190822194901-00248.warc.gz"} |
https://ltwork.net/what-is-the-wavelength-of-a-1-528e-13-j-wave--63 | # What is the wavelength of a 1.528e-13 J wave?
###### Question:
What is the wavelength of a 1.528e-13 J wave?
### Pls help...what is the answer?:(
Pls help...what is the answer?:( $Pls help...what is the answer?:($...
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### Can someone plz solve this one too?
Can someone plz solve this one too?... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5887190699577332, "perplexity": 4390.4830847998155}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571911.5/warc/CC-MAIN-20220813081639-20220813111639-00734.warc.gz"} |
https://wiki.melvoridle.com/index.php?title=Signet_Ring_Half_(b) | # Signet Ring Half (b)
Signet Ring Half (b)
No Description
Item ID: 646
Category: Misc
Type: Misc
Sells For: 850,000
Item Sources:
Item Uses:
The Signet Ring Half (b) is a rare drop that can be combined with to create .
## Item Sources
The Signet Ring Half (b) can be found by killing monsters in combat and slayer areas, or by killing dungeon bosses while the player has a Gold Topaz Ring currently equipped in their active armour slot and the enemy dropped an item other than or another similar guaranteed drop. When found, the Signet Ring Half (b) will be added automatically to the Bank rather than appearing in the 'Loot to Collect' panel.
### Drop Chance Per Kill
The chance for a Signet Ring Half (b) roll to succeed is X in 500,000, where X is the combat level of the monster defeated. As the roll is only made on a loot-generating drop, the chance of a given kill giving the ring half is
$\text{Drop Chance} = \text{Monster Loot Chance} * \frac{\text{Monster Combat Level}}{500,000}$
For example, the has a Combat Level of 101 and a 5% chance to drop loot so the chance per kill of getting the Signet Ring Half (b) is 0.05 * 101 / 500,000 = 0.00101%. Killing a , which has a 100% chance to drop loot and a Combat Level of 100 would give a 1 * 100 / 500,000 = 0.02%.
Players seeking to optimize their drop chance should find a monster that always drops loot and is a good balance between high combat level and short kill time.
### Drop Chance Per Hour
The easiest way to compare monsters is through killing several (or using a combat simulator Extension) to establish an average number of kills per hour and then using the following formula:
$\text{Chance Per Hour} = 1 - (1 - \text{Per Kill Drop Chance})^\text{Kills Per Hour}$
Calculating drop chance over several hours is very similar:
$\text{Total Chance} = 1 - (1 - \text{Per Kill Drop Chance})^{(\text{Kills Per Hour} * \text{Hours})}$
## Uses
Item Created Type Requirements XP Ingredients
Aorpheat's Signet Ring Upgrade None N/A
1,000,000
Melvor Idle version v0.16.3 (Released: 14th September 2020)
Combat:
Skills: Alt Magic
Other: Beginners Guide FAQ Bank Combat Mastery Money Making Shop Easter Eggs Pets Golbin Raid
Reference Tables: Items, Equipment, Experience Table, Upgrading Items, Dungeons, Chest Loot Tables, Monsters, Monster Loot Tables | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.43332111835479736, "perplexity": 9627.186236316182}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107890586.57/warc/CC-MAIN-20201026061044-20201026091044-00300.warc.gz"} |
https://support.bioconductor.org/p/111924/ | Search
Question: The discrepancy between the mean of extracted fitted value and calculated mean and SE based on LFC.
0
9 weeks ago by
Hello, I have a question regarding the discrepancy between the mean of extracted fitted value and calculated mean based on LFC.
First, I want to plot some of our fitted results in barplot, and I tried below code to extract fitted value and plot.
fittedval <- t( t( assays(results)[["mu"]] ) / sizeFactors(results) )
fittedval[gene1,group1]
fittedval[gene1,group2]
Next, I plotted mean and standard error based on the log2foldchange and lfcse from result table, like below.
normalized.count <- counts(results, normalized=T)
std <- function(x) sd(x)/sqrt(length(x))
# Mean, SE of reference level.
m1 <- mean(normalized.count[gene1, group1])
s1 <- std(normalized.count[gene1, group1])
upper.limit <- m1+s1
lower.limit <- m1-s1
# Mean, SE of compared level, based on LFC and LFC-SE.
m2 <- m1 * 1/2^results[i,"log2FoldChange"]
upper.limit2 <- m1 * 1/2^(results[i,"log2FoldChange"]-results[i,"lfcSE"])
lower.limit2 <- m1 * 1/2^(results[i,"log2FoldChange"]+results[i,"lfcSE"])
Now I got mean, upper limit, lower limit of reference level, and group1.
However, when I plotted, the barplot represents different results between those based on fitted value and those based on log2FoldChange. How can this happen? Thank you very much in advance.
ADD COMMENTlink
modified 9 weeks ago • written 9 weeks ago by blastzone.heimerdinger0
1
9 weeks ago by
Michael Love19k
United States
Michael Love19k wrote:
Is this a simple two group comparison or do you have other covariates? Are you using LFC shrinkage? What does it say at the top when you print the DESeqResults object?
The LFC should be close to the log ratio of mean of normalized counts. Are you saying it is not? Can you give the actual values of these?
ADD COMMENTlink modified 9 weeks ago • written 9 weeks ago by Michael Love19k
Hello, Thank you very much for the prompt help! I'm sorry now I can't show you the actual values of these, as I'm away from my workstation, but I have many other covariates like six, and I do not use LFC shrinkage.
ADD REPLYlink written 9 weeks ago by blastzone.heimerdinger0
1
If you have more than a simple single factor design then the LFC is not necessarily equal to the log ratio of the means, because it takes into account the other factors.
ADD REPLYlink modified 9 weeks ago • written 9 weeks ago by Michael Love19k
I understand, thank you very much!
Could you please tell me are there any way to extract fitted full model including other factors for the gene, so I can predict expression values considering other factors to reproduce LFC change?
ADD REPLYlink written 9 weeks ago by blastzone.heimerdinger0
1
This is outside the scope of what DESeq2 provides.
ADD REPLYlink written 9 weeks ago by Michael Love19k
fittedval <- t( t( assays(results)[["mu"]] ) / sizeFactors(results) )
Thank you for the reply, and I'm sorry for the late response. I understand. If I somehow model (like linear model) the above fittedval data with my six independent variables, can I possibly reproduce the similar LFC? I wonder if there is a hint as LFC got promising results and i want to extract matrix that reproduce these, and when I digged in the code, I got lost in fitBeta function...
ADD REPLYlink modified 9 weeks ago • written 9 weeks ago by blastzone.heimerdinger0
You can’t get the same GLM LFC for an arbitrary design with simple operations on the above data. For example, the GLM uses information about the count and the offset which is missing from the above data.
ADD REPLYlink modified 9 weeks ago • written 9 weeks ago by Michael Love19k
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http://mathhelpforum.com/algebra/218083-simplify-expression-isolating-q.html | # Thread: Simplify expression, isolating Q
1. ## Simplify expression, isolating Q
Thank you i advance :-)
2. ## Re: Simplify expression, isolating Q
Hey mrtn.
Hint: Take the -dS/Q^2 term to the RHS side and then take the reciprocal of both sides which will give Q^2/dS = blah. After this you multiply both sides by dS and take the square root.
Show us your attempts so we can guide you through them.
3. ## Re: Simplify expression, isolating Q
Originally Posted by mrtn
Thank you i advance :-)
Question: What is the subscript on h for?
I would move the fraction with Q^2 to the right hand side of the equation to start.
$\frac{h}{2} - \frac{dh}{2p} = \frac{ dS}{Q^2}$
Combine fractions on the left
$\frac{h(p - d)}{2p} = \frac{dS}{Q^2}$
Divide both terms in the parenthesis by p
$\frac{h(1 - \frac{d}{p})}{2} = \frac{Q^2}{dS}$
Invert both sides
$\frac{2}{h(1 - \frac{d}{p})} = \frac{Q^2}{dS}$
Multiply by dS
$\frac{2Sd}{h(1 - \frac{d}{p})} = Q^2$
Extract the root
$Q = \pm \sqrt{\frac{2Sd}{h(1 - \frac{d}{p})}}$
Question: What is the subscript on h for?
4. ## Re: Simplify expression, isolating Q
Hey chiro.
Thank you for your hints.
This is what I can come up with:
I still cant get there.
Sorry about the h / hl thing - they are the same
5. ## Re: Simplify expression, isolating Q
Originally Posted by mrtn
Hey chiro.
Thank you for your hints.
This is what I can come up with:
I still cant get there.
Sorry about the h / hl thing - they are the same
You cannot invert before you combine because it doesn't work COMBINE FIRST , then invert.
$2 + 3 = 5$ but $\frac{1}{2} + \frac{1}{3} \ne \frac{1}{5}$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 8, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9400479197502136, "perplexity": 4015.8645394004634}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-40/segments/1474738660916.37/warc/CC-MAIN-20160924173740-00211-ip-10-143-35-109.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/21377/on-the-convergence-of-sum-mun-ns | # On the convergence of $\sum \mu(n)/n^s$
I arrived at something during my maths ponderings which is really exciting for me.
It is clearly stated in the book on Riemann Hypothesis by Borwein that the convergence of $\sum_{n=1}^{\infty} \frac{\mu(n)}{n^s}$ for $\Re(s) > 1/2$ is necessary and sufficient for RH. This is ofcourse valid since, $\sum \mu(n)/n^s = 1/\zeta(s)$ for $\Re(s) > 1$
Having said that, I have reached a point where I got, for $\Re(s) > 1/2$ $$\left| \frac{\eta(s)}{s} \sum_{n=1}^{\infty} \frac{\mu(n)}{n^s} - \frac{1-2^{1-s}}{s} \right| < \infty$$ $\eta(s)$ is the Dirichlet eta function.
My question is,
What do I interpret out of this formula. Does this result imply RH, or falls short of it?
I believe the second option might be more correct, because this result does not say anything about the zeros of the eta function. But at least it is clear that if $\sum \mu(n)/n^s$ blows up then $\eta(s)$ also must have a zero to bring it down.
Any elaborated answer will be highly appreciated, because it is a current work in progress. :)
-
Let me make sure I understand what you mean by the formula $$\left| \frac{\eta(s)}{s} \sum_{n=1}^{\infty} \frac{\mu(n)}{n^s} - \frac{1-2^{1-s}}{s} \right| < \infty.$$
Do you actually mean that you have proven that this sum is convergent for $s$ in the critical strip and that, for such $s$, this inequality holds? Because, if you have shown that this sum converges in that range, you have already shown RH.
I can think of other interpretations of your statement, but I will wait for clarification before elaborating on them. Here is a basic point to remember: The statement that $\sum_{n=1}^{\infty} a_n$ converges is a statement about the partial sums $\sum_{n=1}^N a_n$. (Namely, that they form a Cauchy sequence.) If you never say anything about these partial sums, it is unlikely you have proved convergence.
Thanks David. I followed on similar lines as by Beurling. Basically, I showed, that this expression satisfies: $$\left| \frac{\eta(s)}{s}\sum_{k=1}^{\infty} \frac{\mu(n)}{n^s} - \frac{1 - 2^{1-s}}{s} \right| \leq || 1 + f_\mu||_2 . || x^{s-1} ||_2$$ where $f_\mu(1/x) = \sum \mu(n)\nu(1/nx)$, $\nu(n) = \rho(x/2) + 1/2 - \rho(x/2 + 1/2)$ where $\rho(x)$ is the fractional part of $x$, and the norm is on $L^2(0,1/2)$ . Then I proceeded to show that $$\lim_{n\to\infty} \left( \int_{0}^{1/2} \left|1 + \sum_{k=1}^{n} \mu(k) \nu(1/kx)\right|^2 dx \right)^{1/2} < \infty$$ – Roupam Ghosh Feb 10 '11 at 23:11
That part is ready, and it does form a Cauchy sequence and this time the result shows that the expression in the main question is zero for $\Re(s) > 1/2$. :) ( I am saying this with a pessimistic voice since the implications are huge and hence the chances of having a unseen bug in my calculations are high :P ) – Roupam Ghosh Feb 11 '11 at 7:50 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9122626185417175, "perplexity": 215.543835167079}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-27/segments/1435375097861.54/warc/CC-MAIN-20150627031817-00183-ip-10-179-60-89.ec2.internal.warc.gz"} |
https://shop.cbmaplefarm.com/products/maple-club-vermont-maple-syrup-club-gift-sets | # Maple Club - Vermont Maple Syrup Gift Sets
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Price includes shipping. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9939879179000854, "perplexity": 16567.32999485004}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514575674.3/warc/CC-MAIN-20190922201055-20190922223055-00323.warc.gz"} |
http://link.springer.com/article/10.1007/s00244-012-9815-y | , Volume 64, Issue 1, pp 52-64
Date: 06 Nov 2012
Contaminants in Stream Sediments From Seven United States Metropolitan Areas: Part II—Sediment Toxicity to the Amphipod Hyalella azteca and the Midge Chironomus dilutus
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Abstract
Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were toxic to amphipods and 12 % of the samples were toxic to midge based on comparisons with reference conditions within each study area. Significant correlations were observed between toxicity end points and sediment concentrations of trace elements, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine (OC) pesticides; however, these correlations were typically weak, and contaminant concentrations were usually below sediment-toxicity thresholds. Concentrations of the pyrethroid bifenthrin exceeded an estimated threshold of 0.49 ng/g (at 1 % total organic carbon) in 14 % of the samples. Of the samples that exceeded this bifenthrin toxicity threshold, 79 % were toxic to amphipods compared with 25 % toxicity for the samples below this threshold. Application of mean probable effect concentration quotients (PECQs) based on measures of groups of contaminants (trace elements, total PAHs, total PCBs, OC pesticides, and pyrethroid pesticides [bifenthrin in particular]) improved the correct classification of samples as toxic or not toxic to amphipods compared with measures of individual groups of contaminants. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9055697917938232, "perplexity": 16099.433125715927}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413507445299.20/warc/CC-MAIN-20141017005725-00358-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/maclaurin-series.229471/ | # Maclaurin Series
• #1
270
1
1. Homework Statement
find the Maclaurin Series:
f(x)=(e^x - cos(x))/x
2. Homework Equations
3. The Attempt at a Solution
I'm not really sure what to do I do know the Maclaurin series of cos(x) I was thinking that using this known series then doing e^x - the known series then dividinig the entire thing by x. I'm just not sure if this is allowed. Do you have to do the known series of e^x - the cos(x) series ? Someone please let me know.
## Answers and Replies
Related Calculus and Beyond Homework Help News on Phys.org
• #2
1,703
5
you know i didn't expect that to work but it does. [series(exp(x))-series(cos(x))]/x is the right answer
• #3
Gib Z
Homework Helper
3,344
4
Either your question wanted you to derive the series for Taylors theorem straight, or more likely not, show that each of those functions are analytic, as you can only do that trick for analytic functions. Most functions studied in analysis, however, are analytic =]
• #4
HallsofIvy
Homework Helper
41,738
899
1. Homework Statement
find the Maclaurin Series:
f(x)=(e^x - cos(x))/x
2. Homework Equations
3. The Attempt at a Solution
I'm not really sure what to do I do know the Maclaurin series of cos(x) I was thinking that using this known series then doing e^x - the known series then dividinig the entire thing by x. I'm just not sure if this is allowed. Do you have to do the known series of e^x - the cos(x) series ? Someone please let me know.
Are you saying you don't know the Maclaurin series for ex? Surely not! The crucial point here is that the first (constant) term of the Maclaurin series for both ex and cos(x) is 1- subtracting them cancels the constant term so that you can then divide by x and still have a Maclaurin series left!
• #5
270
1
I do know the maclaurin series for e^x and for cos(x) :) oh yes you are right; but I do not know if it is acceptable to leave my answer in a form with just like the terms of the series or if it is standard to put the answer into a summation. I can't really figure out the pattern:( because the x^4 terms cancel out and then I am left with 0+ 1 + x + x^2/3! + x^5/^6! so what I did and I do not know if this is correct is subtracted the general terms and then divided by x to get: (x^(n-1))/n!)-((-1)^n*(x^2n-1))/(2n)!
• #6
1,703
5
Either your question wanted you to derive the series for Taylors theorem straight, or more likely not, show that each of those functions are analytic, as you can only do that trick for analytic functions. Most functions studied in analysis, however, are analytic =]
1/x isn't analytic
• #7
270
1
well theres an example in the book with (1-cos(x^2))/x and they did it the same way. I don't really know what an "analytic function is" but I am pretty sure you can do it by subtracting the two series I just don't know if I subtract the general terms or should subtract like the first 5 terms from each series? Because when I subtracted the first 5 terms from each I was left with something kind of odd that I couldn't see a pattern in to put into a summation form.
the terms I end up getting are:
1 + x + (x^2 / 3!) + (x^5 / 6!) - (x^7/ 8!)
Last edited:
• #8
HallsofIvy
Homework Helper
41,738
899
1/x isn't analytic
No, it isn't. However, since all of the functions in this problem are I don't see how that is relevant!
• #9
HallsofIvy
Homework Helper
41,738
899
You know that the general term of the Maclaurin series for ex is 1/n! xn and that the general term of the Maclaurin series for cos(x) is (-1)n/(2n)!x2n or: "0 if n is odd (-1)n/2/n! xn if n is even". The general term of the Maclaurin series for ex- cos(x) is "(1/n!)xn if n is odd, [1/n!- (-1)n/2/(2n+1)!]xn if n is even". Notice that when n is 0 (even), that is 1- 1= 0. Dividing each term by x gives "(1/n!)xn-1 if n is odd, [1/n!- (-1)n/2/(2n+1)!]xn-1 if n is even"
• #10
270
1
ah yes I understand what you are saying here would it be acceptable to write it like that though ? I do not understnad how you got (2n +1) however how did it go from (2n)! to (2n+1)! Since the cos part will be 0 for odd terms can you just say the series is the series you wrote for the even terms since when its odd the cos part will drop out anyway and will give you basically the odd series?
Last edited:
• #11
1,703
5
No, it isn't. However, since all of the functions in this problem are I don't see how that is relevant!
how is the function in question analytic if it is (expx - cosx)*1/x? are you saying simply because it is (expx - cosx ) divided by x f(x) is analytic?
• #12
Hootenanny
Staff Emeritus
Gold Member
9,598
6
how is the function in question analytic if it is (expx - cosx)*1/x? are you saying simply because it is (expx - cosx ) divided by x f(x) is analytic?
What I believe Halls is saying is that if each of the individual functions are analytic, then one can find a series representation of the entire function, whether the entire function is analytic or not.
• #13
270
1
well this is definitely the way to do it we went over it today in class I asked for help as I was still a little confused but thanks guys I sorta get it now? lol i know that you need two summations one for the even and one for the odd getting to them is a little weird
• #14
1,703
5
What I believe Halls is saying is that if each of the individual functions are analytic, then one can find a series representation of the entire function, whether the entire function is analytic or not.
no i understand that but my question still stands.
• #15
Dick
Homework Helper
26,258
618
no i understand that but my question still stands.
I'm not sure what the question is, but (exp(x)-cos(x))/x only has a removable singularity at x=0. Once you plug that whole the resulting function is analytic.
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2K | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9365617036819458, "perplexity": 589.436553037407}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575541308149.76/warc/CC-MAIN-20191215122056-20191215150056-00458.warc.gz"} |
https://physics.stackexchange.com/questions/207604/why-didnt-accelerator-mass-spectrometry-greatly-improve-the-accuracy-of-carbon | # Why didn't accelerator mass spectrometry greatly improve the accuracy of carbon dating?
My understanding of the limitation of radiometric dating is that background radiation swamps the radiation from C14 once the remaining atoms get few enough in number. Accelerator mass spectrometry seems to actually count every atom in the sample, meaning background radiation doesn't matter. Yet the advantage of AMS dating stated here is "can use smaller sample size", not "can give dates much farther into the past using the same sample size". Are the machines too expensive to build one that can test larger samples?
• Reducing the sample size doesn't reduce systematic errors and it doesn't make any sense to improve statistical errors past the point of no-return in any experiment. If the reasonable dating limit is given by e.g. contamination, increasing the count of atoms won't help, either. There is, of course, also the component of cost and experimental complexity. For most research the cost of such a measurement is most likely simply not in the budget. Sep 17 '15 at 22:42
• Isotope separation is pretty expensive, even because a big improvement in the field can be really dangerous at political-military level. Lawrence during WWII used calutrons to separate Uranium 238 and 235, but it was really expensive and inefficient. Sep 17 '15 at 22:46
• To back up @CuriousOne - the detection limits are pretty darn small (Purdue's lab lists detecting one part in 3E14 of C14 vs C12). For a given ion source current, you will get a few C14 ions onto your detector, but your detector has a noise limit. Increasing the ion current tends to make focusing harder by increasing the apparent source size, which reduces your ability to separate the isotopes. So you can count longer, but if you are below the noise floor you aren't doing anything worthwhile. Sep 17 '15 at 22:52
In the end, the ability to accurately count small amounts of sample only gets you logarithmic gains in how far back you can date materials, due to the exponential nature of radioactive decay.
Suppose you have a material with mass $m$, a mass fraction $\chi_\mathrm{C/tot}$ of which is carbon. Then a fraction $\chi_\mathrm{C-14/C} = 10^{-12}$ of its carbon will initially be C-14. We can convert masses to atom counts with the factor $N_A/M$, where $N_A = 6\times10^{23}\ \mathrm{atoms/mol}$ is Avogadro's number and $M = 12\ \mathrm{g/mol}$ is the molar mass of carbon. Suppose also that your detection method is only reliable with a minimum of $N_\mathrm{min}$ C-14 atoms. Then the maximum age you can date is $$T_\mathrm{max} = \tau \log_2\left(\frac{N_A\chi_\mathrm{C/tot}\chi_\mathrm{C-14/C}m}{MN_\mathrm{min}}\right),$$ where $\tau = 5700\ \mathrm{years}$ is the half-life of C-14.
If you decrease $N_\mathrm{min}$ by a factor of $500$ (which seems to be the claim in the link), you increase $T_\mathrm{max}$ by $9$ half-lives, or $50{,}000\ \mathrm{years}$. This isn't too impressive, and the returns are only diminishing. Not only that, but here is a hard limit on how small $N_\mathrm{min}$ can be (you can't detect fractions of an atom!). Certainly by the time $N_\mathrm{min}$ is $10$, the results are statistically unreliable even if your counting is perfect. For $N_\mathrm{min} = 1$, the results are garbage.
On the other hand, decreasing $N_\mathrm{min}$ by $500$ allows you to get the same $T_\mathrm{max}$ with $1/500$ the sample size $m$. This allows for far more things to be tested.
If you want to date something older, you should probably be looking for a different isotope, not a more accurate counting device.
After accepting an answer, I found an answer with a more experimental focus at talkorigins.org.
Why would the instrument reading be noisy if it counts every atom?
The second contribution, laboratory contamination, is largely due to sample chemistry (pretreatment, hydrolysis or combustion to CO2, and reduction to graphite), which generally introduces a small amount of modern carbon, typically at least 1 microgram [8, 12, 13, 14]. Thus a 1 mg sample of infinitely old carbon would measure at least 0.1 pMC (percent modern carbon) before background subtraction...
The third contribution, instrument background, has a number of sources. The main sources are generally the following:
1. ion source “memory” of previous samples, due to radiocarbon sticking to the walls of the ion source, thermally desorbing, and then sticking to another sample
2. mass spectrometer background, non-radiocarbon ions that are misidentified as radiocarbon, sometimes through unexpected mechanisms [16]
3. detector background, including cosmic rays and electronics noise
Why can't the sample size be bigger?
The maximum allowed sample size is typically about 10 mg of carbon. Larger samples produce excessive CO2 pressure in the sealed tubes used in the process, causing tubes to explode and samples to be lost. Thus, even if larger samples like RATE’s “on the order of 100 mg” [6] are submitted to an AMS laboratory, only about 1 mg of carbon will actually undergo analysis. Though Baumgardner calls a 1 mg sample “tiny” [6], it is generally considered “large” by AMS laboratories [e.g., 5, 7, 8], with enough carbon to provide ion source current for about a day.
• The second quote is basically just a design choice. There is nothing inherently limiting in the sizing of experimental volume. Nobody will, of course, give you 100 days of instrument time when an hour is sufficient to do a good measurement and there are, most likely, rather strict limits on that in place. Sep 18 '15 at 1:46 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6720680594444275, "perplexity": 1145.1808040574974}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585504.90/warc/CC-MAIN-20211022084005-20211022114005-00589.warc.gz"} |
https://bioconductor.github.io/BiocWorkshops/ | # 1 Introduction
Editors: Levi Waldron1 Sean Davis2 Marcel Ramos3 Lori Shepherd4. Martin Morgan5.
Welcome to Bioc2018. This year’s conference includes a wide array of workshops for audiences ranging from beginner to advance users and developers. Workshop materials are available as a book in html, pdf, and eBook format at https://bioconductor.github.io/BiocWorkshops/. Workshops are organized by level and topic according to numbers, as described below. Every workshop starts with a syllabus that will help you to decide whether it matches your learning goals.
## 1.1 The Workshops
This book contains workshops for R / Bioconductor training. The workshops are divided into 3 sections:
• Learn (100-series chapters) contains material for beginning users of R and Bioconductor. However, even experienced R and Bioconductor users may find something new here.
• 100: R and Bioconductor for everyone: an introduction
• 101: Introduction to Bioconductor annotation resources
• 102: Solving common bioinformatic challenges using GenomicRanges
• 103: Public data resources and Bioconductor
• Use (200-series chapters) contains workshops emphasizing use of Bioconductor for common tasks, e.g., RNA-seq differential expression, single-cell analysis, gene set enrichment, multi’omics analysis, genome analysis, network analysis, and pharmacogenomics.
• 200: RNA-seq analysis is easy as 1-2-3 with limma, Glimma and edgeR
• 201: RNA-seq data analysis with DESeq2
• 202: Analysis of single-cell RNA-seq data: Dimensionality reduction, clustering, and lineage inference
• 210: Functional enrichment analysis of high-throughput omics data
• 220: Workflow for multi-omics analysis with MultiAssayExperiment
• 230: Cytoscape automation in R using Rcy3
• 240: Fluent genomic data analysis with plyranges
• 250: Working with genomic data in R with the DECIPHER package
• 260: Biomarker discovery from large pharmacogenomics datasets
• Develop (500-series chapters) contains workshops to help expert users hone their skills and contribute their domain-specific knowledge to the Bioconductor community. These workshops are presented on “Developer Day”.
• 500: Effectively using the DelayedArray framework to support the analysis of large datasets
• 510: Maintaining your Bioconductor package
## 1.2 How to use these workshops
These workshops have a lot of package dependencies, and some use data that you must have on disk. There are several ways to run the code from these workshops yourself.
### 1.2.1 Install on your own computer
These workshops were developed for Bioconductor 3.8 (development branch) to allow teaching the most up-to-date methods. Some, but not all, workshop materials will work on Bioconductor 3.7, and (almost?) all should work after the release of Bioconductor 3.8 in October 2018. To run the workshops on your own computer, you should install Bioconductor >= 3.8 (which is the development version before October 2018, and the release version thereafter). The following commands should then install all needed dependencies, at least for Linux:
if (!require("BiocManager"))
install.packages("BiocManager")
BiocManager::install("Bioconductor/BiocWorkshops")
We have noticed that on Windows and Mac, this may not install the required annotation and experimental data packages. If you get errors about missing dependencies, you can install these with additional calls to the BiocManager::install() function.
### 1.2.2 Use the exact same AMI as the workshop
Each participant in the Bioc2018 workshops was provided with their own machine image (called an Amazon Machine Image [AMI]) that contained up-to-date versions of R, required R packages, all necessary operating system libraries, and all workshop materials. This image has been tested by the organizers and more than 100 workshop participants, so if you use it, everything will just work. Using this image is the most hassle-free way to work through these workshops yourself without having to worry about setup.
To use this image yourself (including the AMI image #)… (Lori/Sean)
To offer this image to numerous students in a workshop… (Lori/Sean)
### 1.2.3 Make your own Docker image and AMI
If you want to alter the image in some way, you can rebuild it using packer, a toolkit that enables for the AMI creation process. Clone the GitHub repo:
https://github.com/Bioconductor/BiocWorkshops
Navigate to its packer subdirectory, then you should be able to do packer build bioc_2018.json (after packer is installed and AWS keys sorted out) to create a new AMI based on the Bioc R 3.5.1 devel AMI. You can see the “provision” section for details of the build process (Rscripts, basically). Of course, the json file can be altered for customization, including pegging to specific BiocWorkflow tags, if interested.
1. City University of New York, New York, NY
2. Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
3. City University of New York and Roswell Park Comprehensive Cancer Center, NY
4. Roswell Park Comprehensive Cancer Center, Buffalo, NY
5. Roswell Park Comprehensive Cancer Center, Buffalo, NY | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.1791069656610489, "perplexity": 9533.852939181967}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027313536.31/warc/CC-MAIN-20190818002820-20190818024820-00027.warc.gz"} |
https://math.stackexchange.com/questions/536404/proof-by-induction-for-a-recursive-sequence-and-a-formula | # Proof by Induction for a recursive sequence and a formula
So I have a homework assignment that has brought me great strain over the past 2 days. No video or online example have been able to help me with this issue either and I don't know where to turn.
I’m given
$a_0=0$
$a_n=2a_{n-1}+1$
After writing the first 6 terms of the series: 0, 1, 3, 7, 15, 31, 63 I come up with an alternate formula of
$a_n=2^n-1$
I then have to prove these formulas are the same using Induction in 3 parts:
• Proving the base case
• Stating my Inductive Hypothesis
• Showing the Inductive Step
I have done Inductive proofs before but I don’t know how to show cases or do manipulations on a recursive formula. I don’t know how to represent when n = k then n = k + 1 or showing the approach by using n = k – 1 then n = k.
Any ideas?
For the setup, we need to assume that $a_n = 2^n - 1$ for some $n$, and then show that the formula holds for $n + 1$ instead. That is, we need to show that $$a_{n + 1} = 2^{n + 1} - 1$$
Let's just compute directly:
\begin{align*} a_{n + 1} &= 2a_n + 1 \hspace{1.55in}\text{// recursion relation} \\ &= 2 \cdot (2^n - 1) + 1 \hspace{1in} \text{// induction hypothesis} \\ &= 2^{n + 1} - 2 + 1 \hspace{1.15in} \text{// arithmetic} \\ &= 2^{n + 1} - 1 \end{align*}
which is exactly what we wanted to be true.
• +1, great answer. Just as an aside to this fine answer, I'm not sure what your background is @Chris, but what you've observed here falls under the more general problem of solving linear recurrence relations. Here is a nice resource which describes how you can generally solve recurrence relations of this kind: eecs.yorku.ca/course_archive/2008-09/S/1019/Website_files/…. You can find many more like this by simply searching "solving linear recurrence relations." – Alex Wertheim Oct 23 '13 at 1:37
• You had an oops with your arithmetic when you distributed the 2. But anyway, thank you very much, I can't believe it was so simple or that you could represent things that way. The challenge comes when trying to figure out what side to prove and which side I can manipulate to look like the other side. – Chris Oct 23 '13 at 1:48
Proving the base case should be rather simple.
For the inductive hypothesis, we'll assume that for $k\geq1$, $$a_{k-1}=2^{k-1}-1$$ From this you need to prove that $a_k=2^k-1$. It shouldn't be too tough to get it from here just by following the recurrence relation. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9968653917312622, "perplexity": 172.2883873624854}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046154163.9/warc/CC-MAIN-20210801061513-20210801091513-00470.warc.gz"} |
https://www.atlantis-press.com/proceedings/iciep-20/125966828 | # The Effect of Cooperative Learning in Blended Learning Environment on Students’ Learning Achievement: A True-Experimental Study
Authors
Ridwan1, *
Teacher Training and Education Faculty of Borneo Tarakan University, Tarakan, North Kalimantan Province, Indonesia
*Corresponding Author Email: [email protected]
Corresponding Author
Ridwan
Available Online 23 December 2021.
DOI
10.2991/assehr.k.211219.029How to use a DOI?
Keywords
Cooperative Learning (CL); Blended Learning (BL); e-learning; Learning Achievement
Abstract
The combined blended learning with other teaching strategies has become a considerable concern for educators around the world nowadays. The characteristics of such a blend that can be retrieved at any time, in any place, multi-users, and all its simplicity have made it a very appropriate pedagogical medium for the development of education. This study was conducted to investigate the effect of Cooperative Learning in Blended Learning (CLBL) environment on teaching. The students’ learning achievement by comparing CLBL environment and teacher-led instruction in BL environment and the students’ responses to such learning environment were analyzed. A true-experimental study was employed at the English Education Department of Teacher Training and Education Faculty of Borneo Tarakan University in the 2019-2020 academic year. Sixty-four of fifth-semester students were matched and chosen at random to be a half of them as the experimental class and control class for another half. The main instruments used to gain the intended data were a pretest, a posttest, and an interview guide. The results of the independent samples t-test indicated that the CLBL environment yielded a significant effect on the students’ learning achievement. The students who learned through the CLBL environment far outperformed those who studied through teacher-led instruction in BL environment. This was proved by the probability value of the t-test on the posttest (0.025), which was smaller than the level of significance (0.050). In addition, the students were positive about the productiveness of the CLBL environment, and they found that it really helped them learn.
Open Access
This is an open access article under the CC BY-NC license.
Volume Title
Proceedings of the 2nd International Conference on Innovation in Education and Pedagogy (ICIEP 2020)
Series
Advances in Social Science, Education and Humanities Research
Publication Date
23 December 2021
ISBN
10.2991/assehr.k.211219.029
ISSN
2352-5398
DOI
10.2991/assehr.k.211219.029How to use a DOI?
Open Access
This is an open access article under the CC BY-NC license.
TY - CONF
AU - Ridwan
PY - 2021
DA - 2021/12/23
TI - The Effect of Cooperative Learning in Blended Learning Environment on Students’ Learning Achievement: A True-Experimental Study
BT - Proceedings of the 2nd International Conference on Innovation in Education and Pedagogy (ICIEP 2020)
PB - Atlantis Press
SP - 157
EP - 164
SN - 2352-5398
UR - https://doi.org/10.2991/assehr.k.211219.029
DO - 10.2991/assehr.k.211219.029
ID - 2021
ER - | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.47397416830062866, "perplexity": 6906.515934386694}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296943809.22/warc/CC-MAIN-20230322082826-20230322112826-00690.warc.gz"} |
http://www.gradesaver.com/persepolis-the-story-of-a-childhood/q-and-a/-what-gives-marji-doubts-about-the-notion-of-a-maternal-instinct-246922 | # . What gives Marji doubts about the notion of a “maternal instinct”?
. What gives Marji doubts about the notion of a “maternal instinct”? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9647127389907837, "perplexity": 8320.84222391868}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891812841.74/warc/CC-MAIN-20180219211247-20180219231247-00228.warc.gz"} |
http://mathhelpforum.com/advanced-statistics/195197-weighted-adjusted-average-sound-method.html | # Math Help - weighted/adjusted average - is this a sound method?
1. ## weighted/adjusted average - is this a sound method?
I have been presented with the following challenge in a software program that I am changing. Among other things, the software reads in records that contain four scores, let’s label these scores ‘A’, ‘B’, ‘C’, and ‘D’, (each score can range from 000 to 100). The program calculates the average of these four scores and if the average is greater or equal to 076, it will pass or fail the record. The milestone of 076 had been chosen because based on various other factors, it lead to the fairest outcomes in terms of whether or not these records 'truly' deserved to pass or fail, all other things being considered.
Choosing a milestone that is less than 076 caused too many records to be passed (when they really deserve to fail); and choosing a milestone that is greater than 076, caused too many records to be inappropriately failed.
So for example, if a record contained these values: Score 'A' => 065, Score 'B' => 079, Score 'C' => 090 and Score 'D' => 070, well the average of these scores would be: [(065 + 079 + 090 + 070 ) / 4] = 076. Since 076 is greater or equal to the milestone of: 076, then the record would pass.
Recent changes have caused my customer to re-assess the program's scoring criteria. They stated that due to their nature, scores 'A' and 'B' should be given 'double' the weight in determining the combined average that is compared to the '076' milestone to determine a pass or fail. In English what they are saying, is that when scores ‘A’ and ‘B’ contain high values or low values, that is a greater indicator that the record deserves to pass or fail, then when scores ‘B’ and ‘D’ contain high or low values. So in light of that, the customer simply requested that the formula give scores ‘A’ or ‘B’, double the weight. Without researching the matter, I ‘intuitively’ interpreted the customer’s request as exemplified in the following formula (using the previous example). Note how I am achieving the ‘double weight’ affect by double counting scores ‘A’ and ‘B’. But to equalize things I am using ‘6’ (instead of ‘4’) in the denominator:
[(065 + 065 + 079 + 079 + 090 + 070 ) / 6] = 074.6. Since 074.6 is less than 076, the record would fail under these new rules.
When I ran tests using this formula, the results were favorable and it appeared that the new formula was achieving the desired results.
But I still felt the above formula looked a little ‘dorky’ and unprofessional. I then discovered that I could arrive at the same value by
expressing this way. Note that the ‘double weight’ affect is achieved by adjusting scores ‘A’ and ‘B’ by 67%, and scores ‘C’ and ‘D’ by ‘33%’.
However, I am using ‘2’ in the denominator. Here is the more professional version: [ (.67 * (065 + 079 )) + (.33 * (090 + 070)) ] / 2 = 074.6.
My question is: Is my interpretation of ‘double the weight’ correct, and consistent with sound statistical or mathematical theory ? After all, it is leading to good results. If not, what would be a better formula to use? And if my interpretation is correct, then is there a better way to express the formula?
2. ## Re: weighted/adjusted average - is this a sound method?
Originally Posted by dcs48
My question is: Is my interpretation of ‘double the weight’ correct, and consistent with sound statistical or mathematical theory ? After all, it is leading to good results. If not, what would be a better formula to use? And if my interpretation is correct, then is there a better way to express the formula?
I think what you have done is sound, you have thought about the problem and tested your theory.
I would use $\frac{2A+2B+C+D}{6}$ as $\frac{0.67(A+B)+0.33(C+D)}{2}$ contains a slight error as 0.67 is not exactly double 0.33 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 2, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5619707107543945, "perplexity": 940.6555868424479}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-40/segments/1443737899086.53/warc/CC-MAIN-20151001221819-00020-ip-10-137-6-227.ec2.internal.warc.gz"} |
http://hub.darcs.net/ertes/netwire | # hub.darcs.net :: ertes -> netwire -> files
Functional reactive programming library
# Netwire
Netwire is a functional reactive programming (FRP) library with signal
inhibition. It implements three related concepts, wires, intervals
and events, the most important of which is the wire. To work with
wires we will need a few imports:
import FRP.Netwire
import Prelude hiding ((.), id)
The FRP.Netwire module exports the basic types and helper functions.
It also has some convenience reexports you will pretty much always need
when working with wires, including Control.Category. This is why we
need the explicit Prelude import.
In general wires are generalized automaton arrows, so you can express
many design patterns using them. The FRP.Netwire module provides a
proper FRP framework based on them, which strictly respects continuous
time and discrete event semantics. When developing a framework based on
Netwire, e.g. a GUI library or a game engine, you may want to import
Control.Wire instead.
## Introduction
The following type is central to the entire library:
data Wire s e m a b
Don't worry about the large number of type arguments. They all have
very simple meanings, which will be explained below.
A value of this type is called a wire and represents a reactive
value of type $b$, that is a value that may change over time. It may
depend on a reactive value of type $a$. In a sense a wire is a function
from a reactive value of type $a$ to a reactive value of type $b$, so
whenever you see something of type Wire s e m a b your mind should
draw an arrow from $a$ to $b$. In FRP terminology a reactive value is
called a behavior.
A constant reactive value can be constructed using pure:
pure 15
This wire is the reactive value 15. It does not depend on other
reactive values and does not change over time. This suggests that there
is an applicative interface to wires, which is indeed the case:
liftA2 (+) (pure 15) (pure 17)
This reactive value is the sum of two reactive values, each of which is
just a constant, 15 and 17 respectively. So this is the constant
reactive value 32. Let's spell out its type:
myWire :: (Monad m, Num b) => Wire s e m a b
myWire = liftA2 (+) (pure 15) (pure 17)
This indicates that $m$ is some kind of underlying monad. As an
application developer you don't have to concern yourself much about it.
Framework developers can use it to allow wires to access environment
values through a reader monad or to produce something (like a GUI)
The wires we have seen so far are rather boring. Let's look at a more
interesting one:
time :: (HasTime t s) => Wire s e m a t
This wire represents the current local time, which starts at zero when
execution begins. It does not make any assumptions about the time type
other than that it is a numeric type with a Real instance. This is
enforced implicitly by the HasTime constraint.
The type of this wire gives some insight into the $s$ parameter. Wires
are generally pure and do not have access to the system clock or other
run-time information. The timing information has to come from outside
and is passed to the wire through a value of type $s$, called the state
delta
executing wires.
Since there is an applicative interface you can also apply fmap to a
wire to apply a function to its value:
fmap (2*) time
This reactive value is a clock that is twice as fast as the regular
local time clock. If you use system time as your clock, then the time
type $t$ will most likely be NominalDiffTime from Data.Time.Clock.
However, you will usually want to have time of type Double or some
other floating point type. There is a predefined wire for this:
timeF :: (Fractional b, HasTime t s, Monad m) => Wire s e m a b
timeF = fmap realToFrac time
If you think of reactive values as graphs with the horizontal axis
representing time, then the time wire is just a straight diagonal line
and constant wires (constructed by pure) are just horizontal lines.
You can use the applicative interface to perform arithmetic on them:
liftA2 (\t c -> c - 2*t) time (pure 60)
This gives you a countdown clock that starts at 60 and runs twice as
fast as the regular clock. So it after two seconds its value will be
56, decreasing by 2 each second.
## Testing wires
Enough theory, we wanna see some performance now! Let's write a simple
program to test a constant (pure) wire:
import Control.Wire
import Prelude hiding ((.), id)
wire :: (Monad m) => Wire s () m a Integer
wire = pure 15
main :: IO ()
main = testWire (pure ()) wire
This should just display the value 15. Abort the program by pressing
Ctrl-C. The testWire function is a convenience to examine wires. It
just executes the wire and continuously prints its value to stdout:
testWire ::
(MonadIO m, Show b, Show e)
=> Session m s
-> (forall a. Wire s e Identity a b)
-> m c
The type signatures in Netwire are known to be scary. =) But like most
of the library the underlying meaning is actually very simple.
Conceptually the wire is run continuously step by step, at each step
increasing its local time slightly. This process is traditionally
called stepping.
As an FRP developer you assume a continuous time model, so you don't
observe this stepping process from the point of view of your reactive
application, but it can be useful to know that wire execution is
actually a discrete process.
The first argument of testWire needs some explanation. It is a recipe
for state deltas. In the above example we have just used pure (),
meaning that we don't use anything stateful from the outside world,
particularly we don't use a clock. From the type signature it is also
clear that this sets s = ().
The second argument is the wire to run. The input type is quantified
meaning that it needs to be polymorphic in its input type. In other
words it means that the wire does not depend on any other reactive
value. The underlying monad is Identity with the obvious meaning that
this wire cannot have any monadic effects.
The following application just displays the number of seconds passed
since program start (with some subsecond precision):
wire :: (HasTime t s) => Wire s () m a t
wire = time
main :: IO ()
main = testWire clockSession_ wire
Since this time the wire actually needs a clock we use clockSession_
as the second argument:
clockSession_ ::
=> Session m (Timed NominalDiffTime ())
It will instantiate $s$ to be Timed NominalDiffTime (). This type
indeed has a HasTime instance with $t$ being NominalDiffTime. In
simpler words it provides a clock to the wire. At first it may seem
weird to use NominalDiffTime instead of something like UTCTime, but
this is reasonable, because time is relative to the wire's start time.
Also later in the section about switching we will see that a wire does
not necessarily start when the program starts.
## Constructing wires
Now that we know how to test wires we can start constructing more
complicated wires. First of all it is handy that there are many
convenience instances, including Num. Instead of pure 15 we can
simply write 15. Also instead of
liftA2 (+) time (pure 17)
we can simply write:
time + 17
This clock starts at 17 instead of zero. Let's make it run twice as
fast:
2*time + 17
If you have trouble wrapping your head around such an expression it may
help to read a*b + c mathematically as $a(t) b(t) + c(t)$ and read
time as simply $t$.
So far we have seen wires that ignore their input. The following wire
uses its input:
integral 5
It literally integrates its input value with respect to time. Its
argument is the integration constant, i.e. the start value. To supply
an input simply compose it:
integral 5 . 3
Remember that 3 really means pure 3, a constant wire. The integral
of the constant 3 is $3 t + c$ and here $c = 5$. Here is another
example:
integral 5 . time
Since time denotes $t$ the integral will be $\frac{1}{2} t^2 + c$,
again with $c = 5$. This may sound like a complicated, sophisticated
wire, but it's really not. Surprisingly there is no crazy algebra or
complicated numerical algorithm going on under the hood. Integrating
over time requires one addition and one division each frame. So there
is nothing wrong with using it extensively to animate a scene or to move
objects in a game.
Sometimes categorical composition and the applicative interface can be
inconvenient, in which case you may choose to use the arrow interface.
The above integration can be expressed the following way:
proc _ -> do
t <- time -< ()
integral 5 -< t
Since time ignores its input signal, we just give it a constant signal
with value (). We name time's value $t$ and pass it as the input
signal to integral.
## Intervals
Wires may choose to produce a signal only for a limited amount of time.
We refer to those wires as intervals. When a wire does not produce,
then it inhibits. Example:
for 3
This wire acts like the identity wire in that it passes its input signal
through unchanged:
for 3 . "yes"
The signal of this wire will be “yes”, but after three seconds it will
stop to act like the identity wire and will inhibit forever.
When you use testWire inhibition will be displayed as “I:” followed by
a value, the inhibition value. This is what the $e$ parameter to
Wire is. It's called the inhibition monoid:
for :: (HasTime t s, Monoid e) => t -> Wire s e m a a
As you can see the input and output types are the same and fully
polymorphic, hinting at the identity-like behavior. All predefined
intervals inhibit with the mempty value. When the wire inhibits, you
don't get a signal of type $a$, but rather an inhibition value of type
$e$. Netwire does not interpret this value in any way and in most cases
you would simply use e = ().
Intervals give you a very elegant way to combine wires:
for 3 . "yes" <|> "no"
This wire produces “yes” for three seconds. Then the wire to the left
of <|> will stop producing, so <|> will use the wire to its right
instead. You can read the operator as a left-biased “or”. The signal
of the wire w1 <|> w2 will be the signal of the leftmost component
wire that actually produced a signal. There are a number of predefined
interval wires. The above signal can be written equivalently as:
after 3 . "no" <|> "yes"
The left wire will inhibit for the first three seconds, so during that
interval the right wire is chosen. After that, as suggested by its
name, the after wire starts acting like the identity wire, so the left
side takes precedence. Once the time period has passed the after wire
will produce forever, leaving the “yes” wire never to be reached again.
However, you can easily combine intervals:
after 5 . for 6 . "Blip!" <|> "Look at me..."
The left wire will produce after five seconds from the beginning for six
seconds from the beginning, so effectively it will produce for one
second. When you animate this wire, you will see the string “Look at
me…” for five seconds, then you will see “Blip!” for one second, then
finally it will go back to “Look at me…” and display that one forever.
## Events
Events are things that happen at certain points in time. Examples
include button presses, network packets or even just reaching a certain
point in time. As such they can be thought of as lists of values
together with their occurrence times. Events are actually first class
signals of the Event type:
data Event a
For example the predefined never event is the event that never occurs:
never :: Wire s e m a (Event b)
As suggested by the type events contain a value. Netwire does not
export the constructors of the Event type by default. If you are a
framework developer you can import the Control.Wire.Unsafe.Event
module to implement your own events. A game engine may include events
for key presses or certain things happening in the scene. However, as
an application developer you should view this type as being opaque.
This is necessary in order to protect continuous time semantics. You
cannot access event values directly.
There are a number of ways to respond to an event. The primary way to
do this in Netwire is to turn events into intervals. There are a number
of predefined wires for that purpose, for example asSoonAs:
asSoonAs :: (Monoid e) => Wire s e m (Event a) a
This wire takes an event signal as its input. Initially it inhibits,
but as soon as the event occurs for the first time, it produces the
event's last value forever. The at event will occur only once after
the given time period has passed:
at :: (HasTime t s) => t -> Wire s e m a (Event a)
Example:
at 3 . "blubb"
This event will occur after three seconds, and the event's value will be
“blubb”. Using asSoonAs we can turn this into an interval:
asSoonAs . at 3 . "blubb"
This wire will inhibit for three seconds and then start producing. It
will produce the value “blubb” forever. That's the event's last value
after three seconds, and it will never change, because the event does
not occur ever again. Here is an example that may be more
representative of that property:
asSoonAs . at 3 . time
This wire inhibits for three seconds, then it produces the value 3 (or a
value close to it) forever. Notice that this is not a clock. It does
not produce the current time, but the time at the point in time when
the event occurred.
To combine multiple events there are a number of options. In principle
you should think of event values to form a semigroup (of your choice),
because events can occur simultaneously. However, in many cases the
actual value of the event is not that interesting, so there is an easy
way to get a left- or right-biased combination:
(at 2 <& at 3) . time
This event occurs two times, namely once after two seconds and once
after three seconds. In each case the event value will be the
occurrence time. Here is an interesting case:
at 2 . "blah" <& at 2 . "blubb"
These events will occur simultaneously. The value will be “blah”,
because <& means left-biased combination. There is also &> for
right-biased combination. If event values actually form a semigroup,
then you can just use monoidal composition:
at 2 . "blah" <> at 2 . "blubb"
Again these events occur at the same time, but this time the event value
will be “blahblubb”. Note that you are using two Monoid instances and
one Semigroup instance here. If the signals of two wires form a monoid,
then wires themselves form a monoid:
w1 <> w2 = liftA2 (<>) w1 w2
There are many predefined event-wires and many combinators for
manipulating events in the Control.Wire.Event module. A common events
is the now event:
now :: Wire s e m a (Event a)
This event occurs once at the beginning.
## Switching
We still lack a meaningful way to respond to events. This is where
switching comes in, sometimes also called dynamic switching. The
most important combinator for switching is -->:
w1 --> w2
The idea is really straightforward: This wire acts like w1 as long as
it produces. As soon as it stops producing it is discarded and w2
takes its place. Example:
for 3 . "yes" --> "no"
In this case the behavior will be the same as in the intervals
section, but with two major differences: Firstly when the first
interval ends, it is completely discarded and garbage-collected, never
to be seen again. Secondly and more importantly the point in time of
switching will be the beginning for the new wire. Example:
for 3 . time --> time
This wire will show a clock counting to three seconds, then it will
start over from zero. This is why we usually refer to time as local
time
.
Recursion is fully supported. Here is a fun example:
netwireIsCool =
for 2 . "Once upon a time..." -->
for 3 . "... games were completely imperative..." -->
for 2 . "... but then..." -->
for 10 . ("Netwire 5! " <> anim) -->
netwireIsCool
where
anim =
holdFor 0.5 . periodic 1 . "Hoo..." <|>
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http://blekko.com/wiki/Paper_size?source=672620ff | # Paper size
A size chart illustrating the ISO A series and a comparison with American letter and legal formats.
Comparison of some paper and photographic paper sizes close to the A4 size.
Many paper size standards conventions have existed at different times and in different countries. Today there is one widespread international ISO standard (including A4, B3, C4, etc.) and a local standard used in North America (including letter, legal, ledger, etc.). The paper sizes affect writing paper, stationery, cards, and some printed documents. The standards also have related sizes for envelopes.
## The international standard: ISO 216
### A series
The international paper size standard, ISO 216, is based on the German DIN 476 standard for paper sizes. ISO paper sizes are all based on a single aspect ratio of square root of 2, or approximately 1:1.4142. The base A0 size of paper is defined to have an area of 1 m2. With this definition and the given aspect ratio of square root of two, one can calculate the sides of an A0 sheet as follows: The long side is 1 metre multiplied by the square root of the square root (that is, the fourth root) of 2 and the short side is 1 metre divided by the same. Rounded to millimetres, the A0 paper size is 841 by 1,189 millimetres (33.1 in × 46.8 in).
Successive paper sizes in the series A1, A2, A3, and so forth, are defined by halving the preceding paper size along the larger dimension. The most frequently used paper size is A4 210 by 297 millimetres (8.3 in × 11.7 in).
The significant advantage of this system is its scaling: if a sheet with an aspect ratio of $\sqrt{2}$ is divided into two equal halves parallel to its shortest sides, then the halves will again have an aspect ratio of $\sqrt{2}$. Folded brochures of any size can be made by using sheets of the next larger size, e.g. A4 sheets are folded to make A5 brochures. The system allows scaling without compromising the aspect ratio from one size to another—as provided by office photocopiers, e.g. enlarging A4 to A3 or reducing A3 to A4. Similarly, two sheets of A4 can be scaled down and fit exactly 1 sheet without any cutoff or margins. Weights are easy to calculate as well: a standard A4 sheet made from 80 gram/m2 paper weighs 5 grams (as it is one 16th of an A0 page, measuring 1 m2), allowing one to easily compute the weight—and associated postage rate—by counting the number of sheets used.
The advantages of basing a paper size upon an aspect ratio of $\sqrt{2}$ were already noted in 1786 by the German scientist and philosopher Georg Christoph Lichtenberg.[1] Early in the 20th century, Dr Walter Porstmann turned Lichtenberg's idea into a proper system of different paper sizes. Porstmann's system was introduced as a DIN standard (DIN 476) in Germany in 1922, replacing a vast variety of other paper formats. Even today the paper sizes are called "DIN A4" (pronounced: "deen-ah-fear") in everyday use in Germany and Austria. The term Lichtenberg ratio has recently been proposed for this paper aspect ratio.
The main disadvantage of the system is type does not scale the same way; therefore, when a page is resized, the type set on it loses legibility as the proportion between the type's x-height, page margins, and leading are distorted. When trim is involved, as in the manufacture of books, ISO 216 sizes are generally too tall and narrow for book production (see: Canons of page construction). The distortion is even more pronounced with printed sheet music. European book publishers typically use metricated traditional page sizes for book production.
The DIN 476 standard spread quickly to other countries. Before the outbreak of World War II, it had been adopted by the following countries:
Belgium (1924)Netherlands (1925)Norway (1926) Finland (1927)Switzerland (1929)Sweden (1930) Soviet Union (1934)Hungary (1938)Italy (1939)
During World War II, the standard was adopted by Uruguay (1942), Argentina (1943) and Brazil (1943); and afterwards spread to other countries:
Spain (1947)Austria (1948)Iran (1948)Romania (1949)Japan (1951)Denmark (1953)Czechoslovakia (1953)Israel (1954)Portugal (1954)Yugoslavia (1956)India (1957) Poland (1957)United Kingdom (1959)Republic of Ireland (1959)Venezuela (1962)New Zealand (1963)Iceland (1964)Mexico (1965)South Africa (1966)France (1967)Peru (1967)Turkey (1967) Chile (1968)Greece (1970)Rhodesia (now Zimbabwe) (1970)Singapore (1970)Bangladesh (1972)Thailand (1973)Barbados (1973)Australia (1974)Ecuador (1974)Colombia (1975)Kuwait (1975)
### A4
By 1975 so many countries were using the German system that it was established as an ISO standard, as well as the official United Nations document format. By 1977 A4 was the standard letter format in 88 of 148 countries. Today the standard has been adopted by all countries in the world except the United States and Canada. In Mexico, Costa Rica, Colombia, Venezuela, Chile and the Philippines the US letter format is still in common use, despite their official adoption of the ISO standard.
### B series
A size chart illustrating the ISO B series.
In addition to the A series, there is a less common B series. The area of B series sheets is the geometric mean of successive A series sheets. So, B1 is between A0 and A1 in size, with an area of 0.707 m2 ($\sqrt{1/2}$ m2). As a result, B0 is 1 metre wide, and other sizes in the B series are a half, a quarter or further fractions of a metre wide. While less common in office use, it is used for a variety of special situations. Many posters use B-series paper or a close approximation, such as 50 cm × 70 cm; B5 is a relatively common choice for books. The B series is also used for envelopes and passports. The B-series is widely used in the printing industry to describe both paper sizes and printing press sizes, including digital presses. B3 paper is used to print two US letter or A4 pages side by side using imposition; four pages would be printed on B2, eight on B1, etc.
### C series
A size chart illustrating the ISO C series.
The C series is used only for envelopes and is defined in ISO 269. The area of C series sheets is the geometric mean of the areas of the A and B series sheets of the same number; for instance, the area of a C4 sheet is the geometric mean of the areas of an A4 sheet and a B4 sheet. This means that C4 is slightly larger than A4, and B4 slightly larger than C4. The practical usage of this is that a letter written on A4 paper fits inside a C4 envelope, and a C4 envelope fits inside a B4 envelope.
ISO paper sizes (plus rounded inch values)
FormatA seriesB seriesC series
Sizemm × mmin × inmm × mmin × inmm × mmin × in
0841 × 118933.11 × 46.811000 × 141439.37 × 55.67917 × 129736.10 × 51.06
1594 x 84123.39 × 33.11707 × 100027.83 × 39.37648 × 91725.51 × 36.10
2420 × 59416.54 × 23.39500 × 70719.69 × 27.83458 × 64818.03 × 25.51
3297 × 42011.69 × 16.54353 × 50013.90 × 19.69324 × 45812.76 × 18.03
4210 × 2978.27 × 11.69250 × 3539.84 × 13.90229 × 3249.02 × 12.76
5148 × 2105.83 × 8.27176 × 2506.93 × 9.84162 × 2296.38 × 9.02
6105 × 1484.13 × 5.83125 × 1764.92 × 6.93114 × 1624.49 × 6.38
774 × 1052.91 × 4.1388 × 1253.46 × 4.9281 × 1143.19 × 4.49
852 × 742.05 × 2.9162 × 882.44 × 3.4657 × 812.24 × 3.19
937 × 521.46 × 2.0544 × 621.73 × 2.4440 × 571.57 × 2.24
1026 × 371.02 × 1.4631 × 441.22 × 1.7328 × 401.10 × 1.57
The tolerances specified in the standard are
• ±1.5 mm (0.06 in) for dimensions up to 150 mm (5.9 in),
• ±2 mm (0.08 in) for lengths in the range 150 to 600 mm (5.9 to 23.6 in) and
• ±3 mm (0.12 in) for any dimension above 600 mm (23.6 in).
### German extensions
The German standard DIN 476 was published in 1922 and is the original specification of the A and B sizes. It differs in two details from its international successor:
DIN 476 provides an extension to formats larger than A0, denoted by a prefix factor. In particular, it lists the two formats 2A0, which is twice the area of A0, and 4A0, which is four times A0:
DIN 476 overformats
Namemm × mmin × in
4A01682 × 237866.22 × 93.62
2A01189 × 168246.81 × 66.22
DIN 476 also specifies slightly tighter tolerances:
• ±1 mm (0.04 in) for dimensions up to 150 mm (5.9 in),
• ±1.5 mm (0.06 in) for lengths in the range 150 mm to 600 mm (5.9 to 23.6 in) and
• ±2 mm (0.08 in) for any dimension above 600 mm (23.6 in).
### Swedish extensions
Comparison of ISO 216 and Swedish standard SIS 014711 paper sizes between A4 and A3 sizes.
The Swedish standard SIS 014711 generalized the ISO system of A, B, and C formats by adding D, E, F, and G formats to it. Its D format sits between a B format and the next larger A format (just like C sits between A and the next larger B). The remaining formats fit in between all these formats, such that the sequence of formats A4, E4, C4, G4, B4, F4, D4, H4, A3 is a geometric progression, in which the dimensions grow by a factor 21/16 from one size to the next. However, the SIS 014711 standard does not define any size between a D format and the next larger A format (called H in the previous example). Of these additional formats, G5 (169 × 239 mm) and E5 (155 × 220 mm) are popular in Sweden for printing dissertations,[citation needed] but the other formats have not turned out to be particularly useful in practice and they have not been adopted internationally.
### Japanese B-series variant
The JIS defines two main series of paper sizes. The JIS A-series is identical to the ISO A-series, but with slightly different tolerances. The area of B-series paper is 1.5 times that of the corresponding A-paper (instead of the factor 1.414... for the ISO B-series), so the length ratio is approximately 1.22 times the length of the corresponding A-series paper. The aspect ratio of the paper is the same as for A-series paper. Both A- and B-series paper is widely available in Japan, Taiwan and China, and most photocopiers are loaded with at least A4 and either one of A3, B4 and B5 paper.
There are also a number of traditional paper sizes, which are now used mostly only by printers. The most common of these old series are the Shiroku-ban and the Kiku paper sizes.
JIS paper sizes (plus rounded inch values)
FormatB seriesShiroku banKiku
Sizemm × mmin × inmm × mmin × inmm × mmin × in
01030 × 145640.55 × 57.32
1728 × 103028.66 × 40.55
2515 × 72820.28 × 28.66
3364 × 51514.33 × 20.28
4257 × 36410.12 × 14.33264 × 37910.39 × 14.92227 × 3068.94 × 12.05
5182 × 2577.17 × 10.12189 × 2627.44 × 10.31151 × 2275.94 × 8.94
6128 × 1825.04 × 7.17127 × 1885.00 × 7.40
791 × 1283.58 × 5.04
864 × 912.52 × 3.58
945 × 641.77 × 2.52
1032 × 451.26 × 1.77
1122 × 320.87 × 1.26
1216 × 220.63 × 0.87
### Colombian common sizes naming
The most common paper sizes used for commercial and industrial printing in Colombia are close to the ISO B1, B2 and B3 and are referred to as pliego, ¹⁄₂ pliego and ¹⁄₄ pliego respectively. The "Super-B" size is known as extratabloide.
Colombian paper sizes
Sizemm × mm
Pliego700 x 1000
¹⁄₂ pliego500 x 700
¹⁄₄ pliego350 x 500
Extratabloide440 x 380
## North American paper sizes
### Loose sizes
Current standard sizes of U.S., Canadian and Mexican paper are a subset of the traditional inch-based sizes described below. "Letter", "legal", "ledger", and "tabloid" are by far the most commonly used of these for everyday activities. The origins of the exact dimensions of "letter" size paper (812 in × 11 in or 215.9 mm × 279.4 mm) are lost in tradition and not well documented. The American Forest and Paper Association argues that the dimension originates from the days of manual paper making, and that the 11 inch length of the page is about a quarter of "the average maximum stretch of an experienced vatman's arms."[2] However, this does not explain the width or aspect ratio. Outside of North America, Letter size is also known as "American Quarto"[3] and the size is indeed almost exactly a quarter of the old Imperial (British) paper size known as Demy 4to (17½"×22½"), allowing ½" for trimming.[4]
North American paper sizes
Sizein × inmm × mm
Letter8.5 × 11215.9 × 279.4
Legal8.5 × 14215.9 × 355.6
Junior Legal8.0 × 5.0203.2 × 127
Ledger[5]17 × 11432 × 279
Tabloid11 × 17279 × 432
There is an additional paper size, to which the name "government-letter" was given by the IEEE Printer Working Group: the 8 in × 1012 in (203.2 mm × 266.7 mm) paper that is used in the United States and Canada for children's writing. It was prescribed by Herbert Hoover when he was Secretary of Commerce to be used for U.S. government forms, apparently to enable discounts from the purchase of paper for schools, but more likely due to the standard use of trimming books (after binding) and paper from the standard letter size paper to produce consistency and allow "bleed" printing. In later years, as photocopy machines proliferated, citizens wanted to make photocopies of the forms, but the machines did not generally have this size paper in their bins. Ronald Reagan therefore had the U.S. government switch to regular letter size (812 in × 11 in/215.9 mm × 279.4 mm).[2] The 8 in × 1012 in (203.2 mm × 266.7 mm) size is still commonly used in spiral-bound notebooks and the like, a result of trimming from the current letter dimensions.
U.S. paper sizes are currently standard in the United States, the Philippines and Chile. The latter two use U.S. "letter", but the Philippine and Chilean "legal" size is 812 in × 13 in (215.9 mm × 330.2 mm).[6] ISO sizes are available, but not widely used, in both the U.S. and the Philippines.
In Canada, U.S. paper sizes are a de facto standard. The government, however, uses a combination of ISO paper sizes, and CAN 2-9.60M "Paper Sizes for Correspondence" specifies P1 through P6 paper sizes, which are the U.S. paper sizes rounded to the nearest 5 mm.[7]
Mexico has adopted the ISO standard, but U.S. "letter" format is still the system in use throughout the country. It is virtually impossible to encounter ISO standard papers in day-to-day uses, with "Carta 216 mm × 279 mm" (letter), "Oficio 216 mm × 330 mm" (Government-Legal) and "Doble carta" (ledger/tabloid) being nearly universal. U.S. sizes are also widespread and in common use in Colombia.[8]
#### ANSI paper sizes
A size chart illustrating the ANSI sizes.
In 1996, the American National Standards Institute adopted ANSI/ASME Y14.1 which defined a regular series of paper sizes based upon the de facto standard 812 in × 11 in (215.9 mm × 279.4 mm) "letter" size which it assigned "ANSI A". This series also includes "ledger"/"tabloid" as "ANSI B". This series is somewhat similar to the ISO standard in that cutting a sheet in half would produce two sheets of the next smaller size. Unlike the ISO standard, however, the arbitrary aspect ratio forces this series to have two alternating aspect ratios. The ANSI series is shown below.
With care, documents can be prepared so that the text and images fit on either ANSI or their equivalent ISO sheets at 1:1 reproduction scale.
Namein × inmm × mmRatioAliasSimilar ISO A size
ANSI A8½ × 11216 × 2791.2941LetterA4
ANSI B17 × 11
11 × 17
432 × 279
279 × 432
1.5455Ledger[5]
Tabloid
A3
ANSI C17 × 22432 × 5591.2941A2
ANSI D22 × 34559 × 8641.5455A1
ANSI E34 × 44864 × 11181.2941A0
Other, larger sizes continuing the alphabetic series illustrated above exist, but it should be noted that they are not part of the series per se, because they do not exhibit the same aspect ratios. For example, Engineering F size (28 in × 40 in or 711.2 mm × 1,016.0 mm) also exists, but is rarely encountered, as are G, H, ... N size drawings. G size is 2212 in (571.5 mm) high, but variable width up to 90 in (2,286 mm) in increments of 812 in (215.9 mm), i.e., roll format. H and larger letter sizes are also roll formats. Such sheets were at one time used for full-scale layouts of aircraft parts, wiring harnesses and the like, but are slowly being phased out, due to widespread use of computer-aided design (CAD) and computer-aided manufacturing (CAM). Some visual arts fields also continue to use these paper formats for large-scale printouts, such as for displaying digitally painted character renderings at life-size as references for makeup artists and costume designers, or to provide an immersive landscape reference.
#### Architectural sizes
A size chart illustrating the Architectural sizes.
In addition to the ANSI system as listed above, there is a corresponding series of paper sizes used for architectural purposes. This series also shares the property that bisecting each size produces two of the size below.[9] It may be preferred by North American architects because the aspect ratios (4:3 and 3:2) are ratios of small integers, unlike their ANSI (or ISO) counterparts. Furthermore, the aspect ratio 4:3 matches the traditional aspect ratio for computer displays.[9] The architectural series, usually abbreviated "Arch", is shown below:
Namein × inmm × mmRatio
Arch A9 × 12229 × 3053:4
Arch B12 × 18305 × 4572:3
Arch C18 × 24457 × 6103:4
Arch D24 × 36610 × 9142:3
Arch E36 × 48914 × 12193:4
Arch E130 × 42762 × 10675:7
Arch E226 x 38660 x 96513:19
Arch E327 x 39686 x 9919:13
#### Other sizes
Namein × inmm × mmRatiodot x dot
Organizer J2.75 × 570 × 127~1.8142
Compact4.25 × 6.75108 × 1711.5833
Organizer L, Statement, Half Letter, Memo, Jepps*5.5 × 8.5140 × 2161.54
Executive, Monarch7.25 × 10.5184 × 267~1.4483
Government-Letter8 × 10.5203 × 2671.3125
Foolscap, Folio[5]8.27 × 13210 × 3301.625
Letter, Organizer M8.5 × 11216 × 279~1.2941
Fanfold 12x8.5, German Std Fanfold8.5 × 12216 × 3041.407612 × 864
Government-Legal, Folio8.5 × 13216 × 330~1.5294
Legal8.5 × 14216 × 3561.6481
Quarto9 × 11229 × 2791.2
US Std Fanfold11 × 14.875279 × 377~1.3513792 × 1071
Ledger, Tabloid, Organizer K, Bible11 × 17279 × 4321.54
Super-B13 × 19330 × 483~1.4615
Post15.5 × 19.5394 × 489~1.2581
Crown15 × 20381 × 5081.3
Large Post16.5 × 21419 × 5331.27
Demy17.5 × 22.5445 × 572~1.2857
Medium18 × 23457 × 5841.27
Royal20 × 25508 × 6351.25
Elephant23 × 28584 × 711~1.2174
Double Demy22.5 × 35572 × 8891.5
Quad Demy35 × 45889 × 1143~1.2857
Personal Organizers and Other Corporations[10][11]
CompanyNamePaper Size in x in (Various hole sizes)
FilofaxM2103 x 64 mm with 3 holes
Mini105 x 67 mm with 5 holes
Pocket120 x 81 mm with 6 holes
Personal171 x 95 mm with 6 holes
Slimline171 x 95 mm with 6 holes
A5210 x 148 mm with 6 holes
Deskfax (B5)250 × 176 mm with 9 holes
A4297 x 210 mm with 4 holes
Franklin Planner
Micro2⅝ x 4¼ (66.675 x 108 mm)
Pocket3½ x 6 (89 x 152 mm)
Compact4¼ x 6¾ (108 x 171 mm)
Classic5½ x 8½ (140 x 216 mm)
Monarch8½ x 11 (216 x 280 mm)
*Jeppesen Aeronautical ChartsJeppesen Chart5½ x 8½ (140 x 216 mm) 7 holes
FAA Aeronautical ChartsFAA Chart5½ x 8½ (140 x 216 mm) 3 holes at top
Namein × inmm × mmRatio
Index card3 × 576 × 1271.6
Index card4 × 6102 × 1521.5
Index card5 × 8127 × 2031.6
International business card *2⅛ × 3.3753.98 × 85.61.586
US business card2 × 3.551 × 891.75
Japanese business card~2.165 × ~3.58355 × 91~1.65
Hungarian business card~1.969 × ~3.54350 × 901.8
* This is the same size as the smallest rectangle containing a credit card. However, credit card size, as defined in ISO/IEC 7810, also specifies rounded corners and thickness.
Photographic paper sizes
Namein × inmm × mmRatio
2R2.5 × 3.564 × 891.4
-3 × 576 × 1271.6
LD, DSC3.5 × 4.6789 × 1191.3 (4:3)
3R, L3.5 × 589 × 127~1.4286
LW3.5 × 5.2589 × 1331.5 (3:2)
KGD4 × 5.33102 × 1361.3 (4:3)
4R, KG4 × 6102 × 1521.5 (3:2)
2LD, DSCW5 × 6.67127 × 1691.3 (4:3)
5R, 2L5 × 7127 × 1781.4
2LW5 × 7.5127 × 1901.5 (3:2)
6R6 × 8152 × 2031.3 (4:3)
8R, 6P8 × 10203 × 2541.25
S8R, 6PW8 × 12203 × 3051.5 (3:2)
11R11 × 14279 × 3561.27
A3+, Super B13 × 19330 × 483~1.46154
Postcard size limitations
DimensionMinimum (inch)Maximum (inch)
Height3.54.25
Width5.06.0
Thickness0.0070.016
### Tablet sizes
The sizes listed above are for paper sold loosely in reams. There are many sizes of tablets of paper, that is, sheets of paper bound at one edge, usually by a strip of plastic or hardened PVA adhesive. Often there is a pad of cardboard (also known as chipboard or greyboard) at the bottom of the stack. Such a tablet serves as a portable writing surface, and the sheets often have lines printed on them, usually in blue, to make writing in a line easier. An older means of binding is to have the sheets stapled to the cardboard along the top of the tablet; there is a line of perforated holes across every page just below the top edge from which any page may be torn off. Lastly, a pad of sheets each weakly stuck with adhesive to the sheet below, trademarked as "Post-It" or "Stick-Em" and available in various sizes, serve as a sort of tablet.
"Letter pads" are 812 by 11 inches (215.9 by 279.4 mm), while the term "legal pad" is often used by laymen to refer to pads of various sizes including those of 812 by 14 inches (215.9 by 355.6 mm). There are "steno pads" (used by stenographers) of 6 by 9 inches (152.4 by 228.6 mm).
In countries where the ISO sizes are standard, most notebooks and tablets are sized to ISO specifications (for example, most newsagents in Australia stock A4 and A3 tablets).
Traditionally, a number of different sizes were defined for large sheets of paper, and paper sizes were defined by the sheet name and the number of times it had been folded. Thus a full sheet of "royal" paper was 25 × 20 inches, and "royal octavo" was this size folded three times, so as to make eight sheets, and was thus 10 by 6¼ inches.
Imperial sizes were used in the United Kingdom and its territories. Some of the base sizes were as follows:
Namein × inmm × mmRatio
Emperor48 × 721219 × 18291.5
Antiquarian31 × 53787 × 13461.7097
Grand eagle28.75 × 42730 × 10671.4609
Double elephant26.75 × 40678 × 10161.4984
Atlas*26 × 34660 × 8641.3077
Colombier23.5 × 34.5597 × 8761.4681
Double demy22.5 × 35.5572 × 9021.5(7)
Imperial*22 × 30559 × 7621.3636
Double large post21 × 33533 × 8381.5713
Elephant*23 × 28584 × 7111.2174
Princess21.5 × 28546 × 7111.3023
Cartridge21 × 26533 × 6601.2381
Royal*20 × 25508 × 6351.25
Sheet, half post19.5 × 23.5495 × 5971.2051
Double post19 × 30.5483 × 7621.6052
Super royal19 × 27483 × 6861.4203
Medium*17.5 × 23470 × 5841.2425
Demy*17.5 × 22.5445 × 5721.2857
Large post16.5 × 21419 × 5331.(27)
Copy draught16 × 20406 × 5081.25
Large post15.5 × 20394 × 5081.2903
Post*15.5 × 19.25394 × 4891.2419
Crown*15 × 20381 × 5081.(3)
Pinched post14.75 × 18.5375 × 4701.2533
Foolscap*13.5 × 17343 × 4321.2593
Small foolscap13.25 × 16.5337 × 4191.2453
Brief13.5 × 16343 × 4061.1852
Pott12.5 × 15318 × 3811.2
* The sizes marked with an asterisk are still in use in the United States.
Traditional sizes for writing paper in the United Kingdom. These sizes are no longer commonly used since the UK switched to ISO sizes:[12]
Namein × in
Quarto11 × 9
Foolscap13 × 8
Imperial9 × 7
Kings8 × 6.5
Dukes7 × 5.5
The common divisions and their abbreviations include:
NameAbbr.FoldsLeavesPages
Foliofo, f124
Quarto4to248
Sexto, sixmo6to, 6mo3612
Octavo8vo3816
Duodecimo, twelvemo12mo41224
Sextodecimo, sixteenmo16mo41632
Foolscap folio is often referred to simply as "folio" or "foolscap". Similarly, "quarto" is more correctly "copy draught quarto".
Many of these sizes were only used for making books (see bookbinding), and would never have been offered for ordinary stationery purposes.[13]
### Demitab
The demitab or demi-tab (from the French "demi" or half tabloid) is 5.5 in × 8.5 in (140 mm × 216 mm), equal to one quarter of a sheet of 11 in × 17 in (279 mm × 432 mm) tabloid size paper. In actual circulation, the size 8 in × 10.5 in (203 mm × 267 mm) is common for a demitab.[14] Tabloid newspapers, which are "generally half the size of a broadsheet", also vary in size. To add to the lack of uniformity, broadsheets also vary in size.
Most industry standards express the direction of the grain last (e.g. 17×11 is short grain paper and 11×17 is long grain paper). See switching costs, network effects and standardization for possible reasons for differing regional adoption rates of the ISO standard sizes.
## Transitional paper sizes
### PA series
A transitional size called PA4 (210 mm × 280 mm/8.27 in × 11.02 in) was proposed for inclusion into the ISO 216 standard in 1975. It has the height of Canadian P4 paper (215 mm × 280 mm, about 8½ in × 11 in) and the width of international A4 paper (210 mm × 297 mm/8.27 in × 11.69 in). The table to the right, shows how this format can be generalized into an entire format series.
The PA formats did not end up in ISO 216, because the committee felt that the set of standardized paper formats should be kept to the minimum necessary. However, PA4 remains of practical use today. In landscape orientation, it has the same 4:3 aspect ratio as the displays of traditional TV sets, some computer displays and data projectors. PA4, with appropriate margins, is therefore a good choice as the format of presentation slides.
PA4 is also a useful compromise between A4 and US/Canadian Letter sizes. Hence it is used today by many international magazines, because it can be printed easily on equipment designed for either A4 or US Letter.
PA4-based series
Namemm × mmRatio
PA0840 × 11203:4
PA1560 × 8402:3
PA2420 × 5603:4
PA3280 × 4202:3
PA4210 × 2803:4
PA5140 × 2102:3
PA6105 × 1403:4
PA770 × 1052:3
PA852 × 70≈3:4
PA935 × 52≈2:3
PA1026 × 35≈3:4
### Antiquarian
Although the movement is towards the international standard metric paper sizes, on the way there from the traditional ones there has been at least one new size just a little larger than that used internationally. British architects and industrial designers once used a size called "Antiquarian" as listed above, but given in the New Metric Handbook (Tutt & Adler 1981) as 813 mm × 1,372 mm (32 in × 54 in) for board size. This is a little larger than the A0 size. So for a short time, a size called A0a (1,000 mm × 1,370 mm/39.4 in × 53.9 in) was used in Britain.
## Other metric sizes
Namemm × mmin × inNotes
DL99 × 2103.7 × 8.3common flyer 1/3 of an A4
DLE110 × 2204.3 × 8.7common envelope size as it fits an A4 sheet folded to 1/3 height.
F4210 × 3308.3 × 13.0common in Southeast Asia and Australia. Sometimes called "foolscap" there.
RA0841 × 118933.0125 × 46.75
RA1610 × 86024.0 × 33.9
RA2430 × 61016.9 × 24.0
RA3305 × 43012.0 × 16.9
RA4215 × 3058.5 × 12.0
SRA0900 × 128035.4 × 50.4
SRA1640 × 90025.2 × 35.4
SRA2450 × 64017.7 × 25.2
SRA3320 × 45012.6 × 17.7
SRA4225 × 3208.9 × 12.6
A3+329 × 48313.0 × 19.0
## Newspaper sizes
Newspapers have a separate set of sizes.
In a recent trend[15] many newspapers have been undergoing what is known as "web cut down", in which the publication is redesigned to print using a narrower (and less expensive) roll of paper. In extreme examples, some broadsheet papers are nearly as narrow as traditional tabloids.
## References
1. ^ "Lichtenberg’s letter to Johann Beckmann". Cl.cam.ac.uk. 2006-02-07. Retrieved 2012-01-30.
2. ^ a b American Forest and Paper Association. "Why is the standard paper size in the U.S. 8½" x 11"?". Retrieved 2009-08-04.
3. ^
4. ^ Fyffe, Charles (1969). Basic Copyfitting. London: Studio Vista. p. 74. ISBN 0-289-79705-5.
5. ^ a b c Adobe Systems Incorporated (February 9, 1996). "PostScript Printer Description File Format Specification". San Jose, California. p. 191. Retrieved 2008-03-06
6. ^ Rally de Leon. "Request for inclusion of Page Size 8.5"x13"". Retrieved 2008-08-11.
7. ^ Kuhn, Markus. "International standard paper sizes". Retrieved 2008-03-06.
8. ^ "Armada mil". Retrieved 2010-12-12.
9. ^ a b except for size Arch E1
10. ^
11. ^
12. ^ "Traditional sizes for writing paper in the United Kingdom". atsyn.com. Retrieved 2011-06-30.
13. ^
14. ^ Max Image Area. Horizon Publications.
15. ^ "Press web". Naa.org. Retrieved 2010-12-12. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 4, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6547918319702148, "perplexity": 7353.303483208455}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413507444312.8/warc/CC-MAIN-20141017005724-00271-ip-10-16-133-185.ec2.internal.warc.gz"} |
http://montrealpoutine.com/new-south-wales/find-how-to-find-q-given.php | ## Find How To Find Q Given
write shell script to find maximum and minimum number
Here is one way: there are many others. Let the desired image point be $(a,b)$. Then you want two conditions: 1) The midpoint of the line segment between the given point and the image point is on the given …... 15/08/2010 · Best Answer: To start we need to set up a profit function with the help of the given information. Since Profit is revenue minus costs (Profit = Revenue-Cost) we need to set up the cost function and the revenue function.
How to find each file size in the given folder via SSIS?
There are (combinations of) OpenCV functions/methods to find the difference between two frames of a video. After finding such areas I would then like to know the rate of change of brightness for those locations (between different frames)....
7/09/2015 · 1. The problem statement, all variables and given/known data A large cube has its bottom face on the x-z plane and its back face on the x-y plane. The corners on the x-axis are at (7.93 m,0,0) and (15.9 m,0,0). The cube is immersed in an electric field pointing in the positive x-direction,...
How To Find Q1 And Q3 For A Given Set Of Numbers? Math
how to find the given date is a first sunday or monday and so onsuppose declare @date datetime set @date ='09/21/2010' I need to find the above date falls under first week tuesday or second week tuesday or third week or fourth week or fifth week... how to get rid of hip dips in one day Moreover, it is often not known that systematic mathematical methods to identify Q and R exist. In fact, a recent one is called the Autocovariance least-squares method, and its development started. How to find all sales of a steam game
## Find How To Find Q Given
### Question Question 1 Use the given data to find the best
• How to find brightness of given area OpenCV Q&A Forum
• How To Find Q1 And Q3 For A Given Set Of Numbers? Math
• Question Question 1 Use the given data to find the best
• Given that P = (7 16) and Q = (-1 7) find the component
## Find How To Find Q Given
### Stack Exchange network consists of 174 Q&A communities including Stack Overflow, How do I find the angle given the mass, the acceleration and the force acted on a body? Ask Question 1. My Issue. I have the mass, the horizontal acceleration and a force that acts on a body. The force forms an angle $\alpha$ of unknown degrees with the x-axis. I would like to know how I can find the angle
• Hello. I have the following problem to solve. Suppose I have a reference image consisting of some geometric objects and numbers on a homogeneous background.
• 1/06/2009 · If M (5, 2) is the midpoint of segment PQ and the coordinates of Q are (3, -3), find the coordinates of P.? More questions Find the coordinates of Q given that M is the midpoint of line segment PQ:P(-4, 3) and M(0, 0?
• 4) Know how to find the change in internal energy, D U, of an object given the object does work, W, and absorbs heat, Q. D U = W + Q where work done by an …
• Numbers with 3 identical digits are multiples of 111, which is equal to 3 * 37. 3 * PQR = 3 * x * 37 = XXX This means that (x*37) must have a last digit equal to x. That will only happen for X= 0 or X= 5. X= 0 is a trivial result, so we are left with X=5
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http://chinaxiv.org/user/search.htm?field=keywords&value=GUT | • ### SU(7) Unification of SU(3)CxSU(4)WxU(1)B?LSU(3)CxSU(4)WxU(1)B?LSU(3)_C x SU(4)_W x U(1)_{B-L}
分类： 分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-12-28
摘要：We propose the SUSY SU(7) unification of the SU(3)_C* SU(4)_W* U(1)_{B-L} model. Such unification scenario has rich symmetry breaking chains in a five-dimensional orbifold. We study in detail the SUSY SU(7) symmetry breaking into SU(3)_C* SU(4)_W* U(1)_{B
• ### Realistic flipped SU(5) from orbifold SO(10)
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-05-15
摘要：We propose a realistic flipped SU(5) model derived from a five-dimensional orbifold SO(10) model. The Standard Model (SM) fermion masses and mixings are explained by combining the traditional Froggatt-Nielsen mechanism with the five-dimensional wave function profiles of the SM fermions. Employing tree-level spontaneous R-symmetry breaking in the hidden sector and extra( ordinary) gauge mediation, we obtain realistic supersymmetry breaking soft mass terms with non-vanishing gaugino masses. Including the messenger fields at the intermediate scale and Kaluza-Klein states at the compactification scale, we study gauge coupling unification. We show that the SO(10) unified gauge coupling is very strong and the unification scale can be much higher than the compactification scale. We briefly discuss proton decay as well.
• ### Low-scale SU(4)(W) unification
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-05-15
摘要：We embed the minimal left-right model SU(2) L x SU(2) R x U(1)B-L into an SU(4) W gauge group, and break the unified group via five-dimensional S-1/(Z(2) x Z2) orbifolding. Leptons are fitted into SU(4)(W) multiplets and located on a symmetry preserving O brane, while quarks are placed onto an O' brane where the symmetry is broken. This approach predicts sin(2) theta(W) = 0.25 for the weak mixing angle at tree level and leads to a rather low weakly ( strongly) coupled unification scale of order 3 x 10(2) TeV (several TeV) with supersymmetry, or as low as several TeV in the non-supersymmetric case. Another symmetry breaking chain with the low-energy gauge group SU(2)(L) x U(1)(3R) x U(1)(B-L) can also give rise to a weak mixing angle sin 2. W = 0.25 at tree level after gauge symmetry breaking by orbifolding. Such theories with low-scale unification have interesting phenomenological consequences.
• ### Innate Lymphoid Cells Control Early Colonization Resistance against Intestinal Pathogens through ID2-Dependent Regulation of the Microbiota
分类： 生物学 >> 生物物理学 >> 免疫学 提交时间： 2016-05-11
摘要：Microbiota-mediated effects on the host immune response facilitate colonization resistance against pathogens. However, it is unclear whether and how the host immune response can regulate the microbiota to mediate colonization resistance. ID2, an essential transcriptional regulator for the development of innate lymphoid cell (ILC) progenitors, remains highly expressed in differentiated ILCs with unknown function. Using conditionally deficient mice in which ID2 is deleted from differentiated ILC3s, we observed that these mutant mice exhibited greatly impaired gut colonization resistance against Citrobacter rodentium. Utilizing gnotobiotic hosts, we showed that the ID2-dependent early colonization resistance was mediated by interleukin-22 (IL-22) regulation of the microbiota. In addition to regulating development, ID2 maintained homeostasis of ILC3s and controlled IL-22 production through an aryl hydrocarbon receptor (AhR) and IL-23 receptor pathway. Thus, ILC3s can mediate immune surveillance, which constantly maintains a proper microbiota, to facilitate early colonization resistance through an ID2-dependent regulation of IL-22. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9085529446601868, "perplexity": 12047.063343422258}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296945381.91/warc/CC-MAIN-20230326013652-20230326043652-00667.warc.gz"} |
https://bytepawn.com/calibration-curves-for-delivery-prediction-with-scikit-learn.html | # Calibration curves for delivery prediction with Scikit-Learn
Marton Trencseni - Thu 21 November 2019 - Machine Learning
## Introduction
In a previous post about Machine Learning at Fetchr, I mentioned several families of models we have in production. The latest is Operational Choice, which we use for delivery prediction. The idea is simple: we have a large number of features (essentially columns in our data warehouse) available for our historic dispatches:
• sender's information
• recipient’s information (address, etc.)
• recipient’s historic information
• geography
• scheduling channel
• timing
• etc.
For each dispatch, we know whether it was successfully delivered or not (True/False). Given our historic data, we can build a binary classifier which predicts which orders will be delivered (or not) tomorrow, of all orders scheduled for dispatch. After one-hot encoding, our feature vector length is in the 1000s, and we can achieve 90%+ accuracy with out-of-the-box Scikit-Learn models. In other words, perhaps not too surprisingly, it is possible to predict the chances of delivery success quite well.
When using this in production, we don’t primarily look at the absolute value of the delivery probability itself. What we care about is the relative ordering: out of 1,000 orders, which are the least likely to be delivered successfully tomorrow? Operational Choice is about treating these orders differently. So while in standard ML classification tasks usually the most important metric is accuracy (assuming a balanced dataset), ie. the ratio of test data that is predicted correctly by the predictor, here we also care about calibration: that the relationship between predicted and actual delivery probability should be monotonic, and as close to the x=y line as possible.
As a reminder, the way the binary (delivered or not) predictor models discussed here work is that given a feature vector, they return a probability of delivery, like 0.67 (SKL’s model.predict_proba() functions. If we want to get a True/False prediction, we cut the probability at 0.5, so for 0.67 we would predict True (SKK’s model.predict() function). Accuracy is the ratio of test data (historic dispatches) where the True/False prediction matches the actual True/False historic delivery outcome. To get the calibration curve, we need to convert the True/False historic ground truth to probabilities, so we need to bucket the data and count the ratio of successful deliveries.
Below I show the calibration results for 4 Scikit-Learn models:
The first left chart show the predicted probability on the x-axis, by deciles, as a bar chart; so the first bar is test data points where the model predicted between 0-10% delivery probability, and so on. The y axis is the ratio of test data in the bucket that was actually delivered (ratio of Trues). The right chart shows the number of data points in each decile; since the deciles are fixed, the counts are unbalanced, which leads to inbalanced statistics, ie. the error varies between bars. The lower, third chart shows the same thing, but with equal bucket sizes (total 10 buckets).
To get these results, I used 100,000 randomly chosen training points from our real delivery data and 100,00 test points. Both sets were randomly chosen, so the test distribution matches the training distribution. Both are balanced 50-50 between successful and unsuccessful deliveries.
## LogisticRegression
LogisticRegression is the simplest model, it takes 4 seconds to train. It has an accuracy of 87.9% on the balanced dataset. Both the unbalanced and balanced calibration curves look very good.
## DecisionTree(max_depth=10)
The DecisionTree model, after 13 seconds of training, has an accuracy of 90.1%. The decile calibration curve is beautiful, although the deciles are very unbalanced, so this could be misleading. The balanced calibration curve has an inversion between the 7th and 8th buckets.
## RandomForest(max_depth=10)
The RandomForest model, after 7 seconds of training, has an accuracy of 87.5%. The decile calibration curve is more like a sigmoid, and it’s interesting that the decile counts are skewed torwards the middle. The balanced calibration curve has an inversion between the 7th and 8th buckets, like the DecisionTree.
The GradientBoosting model, after 1,679 seconds of training (!), has an accuracy of 91.1%. Both the balanced and unbalanced calibration curves are very close to the ideal x=y. The decile counts are heavily skewed towards the two ends.
If training time is not an issue, the GradientBoosting model is the best choice, both in terms of accuracy and in terms of calibration. Note how the subsequent gradient boosting steps push the predicted probabilities towards 0 and 1, resulting in the highly skewed decile counts. As a reminder, this is an ensemble of trees, trained and applied in sequence, where each subsequent tree is attempting to correct mistakes made so far; it's this construction which results in the skewed distribution.
It’s also interesting to see how well the LogisticRegression model performs. It’s (i) only 3% off in terms of accuracy from GradientBoosting (ii) in terms of calibration it’s very close to GradientBoosting (iii) it takes only 4 seconds to train, 400x faster than GradientBoosting.
The DecisionTree and the RandomForest models are not very appealing for this use-case. Note how the averaging between the trees in the RandomForest ensemble pulls the predicted probabilities towards 0.5. As a reminder, a DecisionTree cuts along a feature dimension at each step; when predicting, it travels down to a leaf, and returns the ratio of True training points in the leaf bucket. A RandomForest is an ensemble of such trees, with the final prediction being the average of the ensemble trees’ predictions.
Accuracy is usually the primary indicator of how good a classification model is performing. However, in thise case our primary goal is to extract the probabilities, so we can use them for Operational Choice, ie. ranking orders. An imaginary perfect predictor would return p=0 and p=1 at 100% accuracy (so ROC AUC=1). This would be valuable because then we could not dispatch the p=0 orders, since we could be 100% sure they wouldn't be delivered—but this is unrealistic. We actually prefer a model which nicely "stretches" the orders by the actual probability of delivery with a monotonic calibration curve, following the x=y diagonal, like the GradientBoosting model. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6247666478157043, "perplexity": 1529.4284813616518}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178347321.0/warc/CC-MAIN-20210224194337-20210224224337-00561.warc.gz"} |
https://rd.springer.com/article/10.1186/s13662-020-02778-8?error=cookies_not_supported&code=1028499f-86fb-4ab3-9881-6485a27cfec2 | # Some results on degenerate Daehee and Bernoulli numbers and polynomials
## Abstract
In this paper, we study a degenerate version of the Daehee polynomials and numbers, namely the degenerate Daehee polynomials and numbers, which were actually called the degenerate Daehee polynomials and numbers of the third kind and recently introduced by Jang et al. (J. Comput. Appl. Math. 364:112343, 2020). We derive their explicit expressions and some identities involving them. Further, we introduce the multiple degenerate Daehee numbers and higher-order degenerate Daehee polynomials and numbers which can be represented in terms of integrals on the unitcube. Again, we deduce their explicit expressions and some identities related to them.
## Introduction
The degenerate versions of Bernoulli and Euler polynomials, namely the degenerate Bernoulli and Euler polynomials, were studied by Carlitz in [1]. In recent years, studying various degenerate versions of some special polynomials and numbers drew attention of some mathematicians and many arithmetic and combinatorial results were obtained [4, 5, 8, 12, 13, 1517, 19, 20]. They can be explored by using various tools like combinatorial methods, generating functions, differential equations, umbral calculus techniques, p-adic analysis, and probability theory.
The aim of this paper is to study a degenerate version of the Daehee polynomials and numbers, namely the degenerate Daehee polynomials and numbers, in the spirit of [1]. They were actually called the degenerate Daehee polynomials and numbers of the third kind and recently introduced by Jang et al. in [4]. We derive their explicit expressions and some identities involving them. Further, we introduce the multiple degenerate Daehee numbers and higher-order degenerate Daehee polynomials and numbers. Again, we deduce their explicit expressions and some identities related to them.
This paper is organized as follows. In Sect. 1, we state what we need in the rest of the paper. These include the Stirling numbers of the first and second kinds, the higher-order Bernoulli polynomials, the higher-order Daehee polynomials, the higher-order degenerate Bernoulli polynomials, the degenerate exponential functions, and the degenerate Stirling numbers of the first and second kinds. In Sect. 2, we recall the degenerate Daehee polynomials and numbers (of the third kind) from [4] whose generating functions can be expressed in terms of integrals on the unit interval. We find their explicit expressions and some identities involving them. We also introduce the multiple degenerate Daehee numbers, the generating function of which can be expressed in terms of a multiple integral on the unitcube or of the modified polyexponential function [7]. We deduce an explicit expression of them and some identities involving them. In Sect. 3, we introduce the higher-order degenerate Daehee polynomials and numbers whose generating function can be represented as a multiple integral on the unitcube. We derive their explicit expressions and some identities relating to them. Finally, we conclude this paper in Sect. 4.
For $$n \ge 0$$, the Stirling numbers of the first kind are defined by
$$(x)_{n} = \sum _{l=0}^{n}S_{1}(n,l)x^{l} \quad \bigl(\mbox{see [8, 14]}\bigr),$$
(1.1)
where $$(x)_{0} = 1$$, $$(x)_{n} = x(x-1)\cdots (x-n+1)$$, $$(n \geq 1)$$.
As an inversion formula of (1.1), the Stirling numbers of the second kind are defined as
\begin{aligned} x^{n} = \sum _{l=0}^{n}S_{2}(n,l) (x)_{l}, (n \ge 0) \quad \bigl(\mbox{see [8, 14, 16]}\bigr). \end{aligned}
(1.2)
For $$\alpha \in \mathbb{N}$$, the Bernoulli polynomials of order α are defined as
\begin{aligned} \biggl(\frac{t}{e^{t}-1} \biggr)^{\alpha }e^{xt} = \sum_{n=0}^{ \infty }B_{n}^{(\alpha )}(x) \frac{t^{n}}{n!} \quad \bigl(\mbox{see [4, 16]}\bigr). \end{aligned}
(1.3)
$$B_{n}(x) = B_{n}^{(1)}(x)$$ are called the Bernoulli polynomials and $$B^{(\alpha )}_{n} = B^{(\alpha )}_{n}(0)$$ the Bernoulli numbers of order α.
The Daehee polynomials are defined by
\begin{aligned} \biggl( \frac{\log (1+t)}{t} \biggr) (1+t)^{x} = \sum_{n=0}^{ \infty }D_{n}(x) \frac{t^{n}}{n!}\quad \bigl(\mbox{see [2, 3, 6, 9--11, 14, 15, 18, 21--34]} \bigr). \end{aligned}
(1.4)
For $$x=0$$, $$D_{n} = D_{n}(0)$$ are called the Daehee numbers.
Recently, Jang–Kim–Kwon–Kim studied some new results on degenerate Daehee polynomials and numbers of the third kind (see [4]).
That is, they derived a new integral representation for the degenerate Daehee number and polynomials, the higher-order λ-Daehee numbers and polynomials, and the higher-order twisted λ-Daehee numbers and polynomials (see [4]).
The Daehee polynomials of order k are defined by
\begin{aligned} \biggl(\frac{\log (1+t)}{t} \biggr)^{k}(1+t)^{x} = \sum _{n=0}^{ \infty }D_{n}^{(k)}(x) \frac{t^{n}}{n!} \quad \bigl(\mbox{see [4, 10]}\bigr). \end{aligned}
(1.5)
In [9], we note that
\begin{aligned} D_{m}^{(k)}(z) = m!\sum_{n=0}^{m}\binom{z }{m-n}b_{m}^{(-k)}, \end{aligned}
(1.6)
where $$b_{n}^{(x)}$$ are the higher-order Bernoulli numbers of the second kind given by
$$\biggl(\frac{t}{\log (1+t)} \biggr)^{x}=\sum _{n=0}^{\infty }b_{n}^{(x)}t^{n}.$$
(1.7)
Recently, Daehee numbers and polynomials have been studied by many researchers in various areas (see [2, 3, 6, 911, 14, 15, 18, 2134]).
In [1], Carlitz considered the degenerate Bernoulli polynomials given by
\begin{aligned} \frac{t}{(1+\lambda t)^{\frac{1}{\lambda }}-1}(1+ \lambda t)^{\frac{x}{\lambda }} = \sum_{n=0}^{\infty } \beta _{n, \lambda }^{(x)}\frac{t^{n}}{n!} \quad(\lambda \in \mathbb{R}). \end{aligned}
(1.8)
When $$x=0$$, $$\beta _{n,\lambda } = \beta _{n,\lambda }(0)$$ are called the degenerate Bernoulli numbers. For $$r \in \mathbb{N}$$, he also defined the higher–order degenerate Bernoulli polynomials as
\begin{aligned} \biggl(\frac{t}{(1+\lambda t)^{\frac{1}{\lambda }}-1} \biggr)^{r}(1+\lambda t)^{\frac{x}{\lambda }} = \sum _{n=0}^{\infty } \beta _{n,\lambda }^{(r)}(x) \frac{t^{n}}{n!} \quad \bigl(\mbox{see [16]}\bigr). \end{aligned}
(1.9)
When $$x=0$$, $$\beta _{n,\lambda }^{(r)} = \beta _{n,\lambda }^{(r)}(0)$$ are called the degenerate Bernoulli numbers of order r.
The degenerate exponential functions are given by
$$e^{x}_{\lambda }(t) = (1+\lambda t)^{\frac{x}{\lambda }}, e_{\lambda }(t) = e^{1}_{\lambda }(t) = (1+\lambda t)^{ \frac{1}{\lambda }} \quad \bigl(\mbox{see [7--9, 12--14, 16--20]}\bigr).$$
(1.10)
We note that
$$e^{x}_{\lambda }(t) = \sum_{n=0}^{\infty } \frac{(x)_{n,\lambda }}{n!}t^{n} \quad \bigl(\mbox{see [8]}\bigr),$$
(1.11)
where $$(x)_{0,\lambda } = 1$$, $$(x)_{n,\lambda } = x(x-\lambda )\cdots (x-(n-1)\lambda )$$$$(n \ge 1)$$.
Note that $$\lim_{\lambda \to 0} e_{\lambda }^{x}(t) = e^{xt}$$, $$\lim_{\lambda \to 0}\beta ^{(r)}_{n,\lambda }(x) = B_{n}^{(r)}(x)$$.
Recently, Kim considered the degenerate Stirling numbers of the second kind given by
\begin{aligned} (x)_{n,\lambda } = \sum _{l=0}^{n}S_{2,\lambda }(n,l) (x)_{l}, (n \ge 0) \quad \bigl(\mbox{see [8]}\bigr). \end{aligned}
(1.12)
Note that $$\lim_{\lambda \to 0}S_{2,\lambda }(n,l) = S_{2}(n,l)$$.
From (1.12), we note that
\begin{aligned} \frac{1}{k!} \bigl(e_{\lambda }(t)-1\bigr)^{k} = \sum _{n=k}^{ \infty }S_{2,\lambda }(n,k) \frac{t^{n}}{n!}\quad (k \ge 0) \bigl(\mbox{see [8]}\bigr). \end{aligned}
(1.13)
As an inversion formula of (1.12), the Stirling numbers of the first kind are defined by
\begin{aligned} (x)_{n} = \sum _{l=0}^{n}S_{1,\lambda }(n,l) (x)_{l, \lambda }\quad (n \ge 0) \bigl(\mbox{see [8]}\bigr). \end{aligned}
(1.14)
We see that $$\log _{\lambda }(t)=\frac{1}{\lambda }(t^{\lambda }-1)$$ is the compositional inverse of $$e_{\lambda }(t)$$ satisfying $$\log _{\lambda }(e_{\lambda }(t)) = e_{\lambda }(\log _{\lambda }(t)) = t$$.
By (1.14), we get
\begin{aligned} \frac{1}{k!} \bigl(\log _{\lambda }(1+t) \bigr)^{k} = \sum _{n=k}^{\infty }S_{1,\lambda }(n,k) \frac{t^{n}}{n!} \quad \bigl(\mbox{see [8]}\bigr). \end{aligned}
(1.15)
Note that $$\lim_{\lambda \to 0}\log _{\lambda }(1+t) = \log (1+t)$$.
## Degenerate Daehee numbers and polynomials
The degenerate Daehee polynomials are defined by (see [4])
\begin{aligned} \frac{\log _{\lambda }(1+t)}{t}(1+t)^{x} = \sum_{n=0}^{ \infty }D_{n,\lambda }(x) \frac{t^{n}}{n!}, \quad(\lambda \in \mathbb{R}). \end{aligned}
(2.1)
When $$x=0$$, $$D_{n,\lambda } = D_{n,\lambda }(0)$$ are called the degenerate Daehee numbers.
From (1.4) and (2.1), we note that $$\lim_{\lambda \to 0}D_{n,\lambda }(x) = D_{n}(x)$$$$(n \ge 0)$$.
We observe that
\begin{aligned} \frac{\log (1+t)}{t} \int _{0}^{1}(1+t)^{\lambda y+x}\,dy = \frac{\log _{\lambda }(1+t)}{t}(1+t)^{x} = \sum_{n=0}^{\infty }D_{n, \lambda }(x) \frac{t^{n}}{n!}. \end{aligned}
When $$x=0$$, we have
\begin{aligned} \frac{\log (1+t)}{t} \int _{0}^{1}(1+t)^{\lambda y} \,dy = \sum _{n=0}^{\infty }D_{n,\lambda } \frac{t^{n}}{n!}. \end{aligned}
(2.2)
On the other hand,
\begin{aligned}[b] &\frac{\log (1+t)}{t} \int _{0}^{1}(1+t)^{\lambda y}\,dy\\ &\quad = \frac{\log (1+t)}{t}\sum_{m=0}^{\infty } \frac{\lambda ^{m}(\log (1+t))^{m}}{(m+1)!} \\ & \quad = \frac{1}{t}\sum_{m=0}^{\infty } \frac{(\log (1+t))^{m+1}}{(m+1)!}\lambda ^{m} = \frac{1}{t}\sum _{m=1}^{ \infty }\lambda ^{m-1} \frac{1}{m!}\bigl(\log (1+t)\bigr)^{m} \\ &\quad = \frac{1}{t}\sum_{m=1}^{\infty } \lambda ^{m-1}\sum_{n=m}^{ \infty }S_{1}(n,m) \frac{t^{n}}{n!} = \frac{1}{t}\sum_{n=1}^{\infty } \Biggl(\sum_{m=1}^{n}\lambda ^{m-1}S_{1}(n,m) \Biggr) \frac{t^{n}}{n!} \\ & \quad = \sum_{n=0}^{\infty } \Biggl( \frac{1}{n+1}\sum_{m=1}^{n+1} \lambda ^{m-1}S_{1}(n+1,m) \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(2.3)
Therefore, by (2.2) and (2.3), we obtain the following theorem.
### Theorem 2.1
For$$n\ge 0$$, we have
\begin{aligned} D_{n,\lambda } = \frac{1}{n+1}\sum _{m=1}^{n+1}\lambda ^{m-1}S_{1}(n+1,m). \end{aligned}
By replacing t by $$e_{\lambda }(t)-1$$ in (2.1), we get
\begin{aligned}[b] \frac{t}{e_{\lambda }(t)-1}e_{\lambda }^{x}(t) & = \sum_{m=0}^{ \infty }D_{m,\lambda }(x) \frac{1}{m!}\bigl(e_{\lambda }(t)-1\bigr)^{m} \\ & = \sum_{m=0}^{\infty }D_{m,\lambda }(x) \sum_{n=m}^{\infty }S_{2, \lambda }(n,m) \frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty } \Biggl(\sum _{m=0}^{n}D_{m,\lambda }(x)S_{2, \lambda }(n,m) \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(2.4)
On the other hand,
$$\frac{t}{e_{\lambda }(t)-1}e_{\lambda }^{x}(t) = \sum_{n=0}^{ \infty }\beta _{n,\lambda }(x)\frac{t^{n}}{n}.$$
(2.5)
Therefore, by (2.4) and (2.5), we obtain the following theorem.
### Theorem 2.2
For$$n \ge 0$$, we have
$$\beta _{n,\lambda }(x) = \sum _{m=0}^{n} D_{m,\lambda }(x)S_{2, \lambda }(n,m).$$
Note that
$$B_{n}(x) = \lim_{\lambda \to 0} \beta _{n,\lambda }(x) = \sum_{m=0}^{n}D_{m}(x)S_{2}(n,m) \quad (n \ge 0).$$
To find the inversion formula of Theorem 2.2, we replace t by $$\log _{\lambda }(1+t)$$ in (1.8) and get
\begin{aligned}[b] \frac{\log _{\lambda }(1+t)}{t}(1+t)^{x}& = \sum_{m=0}^{ \infty }\beta _{m,\lambda }(x)\frac{1}{m!} \bigl(\log _{\lambda }(1+t) \bigr)^{m} \\ & = \sum_{m=0}^{\infty }\beta _{m,\lambda }(x)\sum_{n=m}^{\infty }S_{1, \lambda }(n,m) \frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty } \Biggl(\sum _{m=0}^{n}\beta _{m,\lambda }(x)S_{1, \lambda }(n,m) \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(2.6)
Therefore, by (2.1) and (2.6), we obtain the following theorem.
### Theorem 2.3
For$$n \ge 0$$, we have
\begin{aligned} D_{n,\lambda }(x) = \sum _{m=0}^{n}\beta _{m,\lambda }(x)S_{1, \lambda }(n,m). \end{aligned}
Note that
\begin{aligned} D_{n}(x) = \lim_{\lambda \to 0}D_{n,\lambda }(x) = \sum_{m=0}^{n}B_{m}(x)S_{1}(n,m) \quad (n \ge 0). \end{aligned}
From (1.10), we can derive the following equation:
\begin{aligned} \sum_{n=0}^{\infty }D_{n,\lambda }(x) \frac{t^{n}}{n!} =& \frac{\log _{\lambda }(1+t)}{t}(1+t)^{x} = \frac{\log _{\lambda }(1+t)}{t}e_{\lambda }^{x}\bigl(\log _{\lambda }(1+t)\bigr) \\ =& \frac{\log _{\lambda }(1+t)}{t} \sum_{m=0}^{\infty }(x)_{m, \lambda } \frac{(\log _{\lambda }(1+t))^{m}}{m!} \\ =& \frac{1}{t}\sum_{m=0}^{\infty }(m+1) (x)_{m,\lambda } \frac{1}{(m+1)!} \bigl(\log _{\lambda }(1+t) \bigr)^{m+1} \\ =& \frac{1}{t}\sum_{m=0}^{\infty }(m+1) (x)_{m,\lambda }\sum_{n=m+1}^{ \infty }S_{1,\lambda }(n,m+1) \frac{t^{n}}{n!} \end{aligned}
(2.7)
\begin{aligned} = &\sum_{m=0}^{\infty }(m+1) (x)_{m,\lambda }\sum_{n=m}^{ \infty } \frac{S_{1,\lambda }(n+1,m+1)}{n+1}\frac{t^{n}}{n!} \\ = &\sum_{n=0}^{\infty } \Biggl\{ \frac{1}{n+1}\sum_{m=0}^{n}(m+1) (x)_{m, \lambda }S_{1,\lambda }(n+1,m+1) \Biggr\} \frac{t^{n}}{n!}. \end{aligned}
(2.8)
Therefore, by (2.7), we obtain the following theorem.
### Theorem 2.4
For$$n \ge 0$$, we have
$$D_{n,\lambda }(x) = \frac{1}{n+1}\sum _{m=0}^{n}(m+1) (x)_{m, \lambda }S_{1,\lambda }(n+1,m+1).$$
For $$s \in \mathbb{C}$$, the polyexponential function is defined by Hardy as
\begin{aligned} e(x,a|s) = \sum _{n=0}^{\infty } \frac{x^{n}}{(n+a)^{s}n!}, \bigl( \operatorname{Re}(a) > 0\bigr) \quad \bigl(\mbox{see [16]}\bigr). \end{aligned}
(2.9)
In [7], the modified polyexponential function is introduced as
\begin{aligned} \mathrm{Ei}_{k}(x) = \sum _{n=1}^{\infty } \frac{x^{n}}{(n-1)!n^{k}}\quad (k \in \mathbb{Z}). \end{aligned}
(2.10)
Note that x$$e(x,1|k) = \mathrm{Ei}_{k}(x)$$.
We observe that
\begin{aligned} \frac{\partial }{\partial x_{1}}(1+t)^{\lambda x_{1}x_{2} \cdots x_{k}} = x_{2}\cdots x_{k}\lambda \log (1+t) (1+t)^{\lambda x_{1}x_{2} \cdots x_{k}}. \end{aligned}
(2.11)
Thus, by (2.11), we get
\begin{aligned}[b] &\frac{\log (1+t)}{t} \int _{0}^{1}(1+t)^{\lambda x_{1}x_{2} \cdots x_{k}}\,dx_{1}\\ &\quad = \frac{1}{x_{2}x_{3}\cdots x_{k}} \frac{\log _{\lambda }(1+t)^{x_{2}\cdots x_{k}}}{t} \\ & \quad = \frac{1}{t}\frac{1}{x_{2}x_{3}\cdots x_{k}}\sum _{m=1}^{ \infty }\lambda ^{m-1} \frac{(\log (1+t))^{m}}{m!}x_{2}^{m}x_{3}^{m} \cdots x_{k}^{m} \\ & \quad = \frac{1}{t}\sum_{m=1}^{\infty } \frac{\lambda ^{m-1}(\log (1+t))^{m}}{(m-1)!m} x_{2}^{m-1}x_{3}^{m-1} \cdots x_{k}^{m-1}. \end{aligned}
(2.12)
From (2.12), we can derive the following equation:
\begin{aligned}[b] & \frac{\log (1+t)}{t} \int _{0}^{1}\cdots \int _{0}^{1}(1+t)^{ \lambda x_{1}x_{2}\cdots x_{k}}\,dx_{1}\,dx_{2} \cdots \,dx_{k} \\ & \quad = \frac{1}{t}\sum_{m=1}^{\infty } \frac{\lambda ^{m-1}(\log (1+t))^{m}}{(m-1)!m^{k}} = \frac{1}{\lambda t}\mathrm{Ei}_{k}\bigl( \lambda \log (1+t)\bigr). \end{aligned}
(2.13)
Now, we define the multiple degenerate Daehee numbers as the multiple integral on the unitcube given by
$$\frac{\log (1+t)}{t} \int _{0}^{1}\cdots \int _{0}^{1}(1+t)^{ \lambda x_{1}x_{2}\cdots x_{k}}\,dx_{1}\,dx_{2} \cdots dx_{k} = \sum_{n=0}^{\infty } \widehat{D}_{n,\lambda }^{(k)} \frac{t^{n}}{n!}.$$
(2.14)
Then, by (2.13) and (2.14), we get
$$\frac{1}{\lambda t} \mathrm{Ei}_{k}\bigl(\lambda \log (1+t)\bigr) = \sum _{n=0}^{ \infty }\widehat{D}_{n,\lambda }^{(k)} \frac{t^{n}}{n!}.$$
(2.15)
Note that $$\widehat{D}_{n,\lambda }^{(1)} = D_{n,\lambda }$$$$( n \ge 0)$$.
We observe that
\begin{aligned}[b] \frac{1}{\lambda t} \mathrm{Ei}_{k}\bigl(\lambda \log (1+t)\bigr) &= \frac{1}{\lambda t} \sum_{m=1}^{\infty } \frac{\lambda ^{m}(\log (1+t))^{m}}{(m-1)!m^{k}} \\ & = \frac{1}{\lambda t} \sum_{m=1}^{\infty } \frac{\lambda ^{m}}{m^{k-1}}\frac{1}{m!}\bigl(\log (1+t)\bigr)^{m}\\ &= \frac{1}{\lambda t}\sum_{m=1}^{\infty } \frac{\lambda ^{m}}{m^{k-1}} \sum_{n=m}^{\infty }S_{1}(n,m) \frac{t^{n}}{n!} \\ & = \frac{1}{t}\sum_{n=1}^{\infty } \sum_{m=1}^{n} \frac{\lambda ^{m-1}}{m^{k-1}} S_{1}(n,m)\frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty } \Biggl( \frac{1}{n+1}\sum_{m=1}^{n+1} \frac{\lambda ^{m-1}}{m^{k-1}}S_{1}(n+1,m) \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(2.16)
Therefore, by (2.15) and (2.16), we obtain the following theorem.
### Theorem 2.5
For$$n \ge 0$$, we have
\begin{aligned} \widehat{D}_{n,\lambda }^{(k)} = \frac{1}{n+1}\sum_{m=1}^{n+1} \frac{\lambda ^{m-1}}{m^{k-1}}S_{1}(n+1,m). \end{aligned}
By replacing t by $$e^{t}-1$$ in (2.15), we get
\begin{aligned}[b] \sum_{m=0}^{\infty } \widehat{D}_{m,\lambda }^{(k)} \frac{1}{m!} \bigl(e^{t}-1\bigr)^{m} & = \frac{1}{\lambda (e^{t}-1)} \mathrm{Ei}_{k}( \lambda t) \\ & = \frac{t}{e^{t}-1}\frac{1}{\lambda t}\mathrm{Ei}_{k}( \lambda t) = \sum_{l=0}^{\infty }B_{l} \frac{t^{l}}{l!}\sum_{m=0}^{\infty } \frac{\lambda ^{m}}{(m+1)^{k}}\frac{t^{m}}{m!}. \\ & = \sum_{n=0}^{\infty } \Biggl(\sum _{l=0}^{n}\binom{n }{l} \frac{\lambda ^{n-l}B_{l}}{(n-l+1)^{k}} \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(2.17)
On the other hand,
\begin{aligned}[b] \sum_{m=0}^{\infty } \widehat{D}_{m,\lambda }^{(k)} \frac{1}{m!} \bigl(e^{t}-1\bigr)^{m}& = \sum _{m=0}^{\infty }\widehat{D}_{m, \lambda }^{(k)} \sum_{n=m}^{\infty }S_{2}(n,m) \frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty } \Biggl(\sum _{m=0}^{n}\widehat{D}_{m, \lambda }^{(k)}S_{2}(n,m) \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(2.18)
Therefore, by (2.17) and (2.18), we obtain the following theorem.
### Theorem 2.6
For$$n \ge 0$$, we have
$$\sum_{m=0}^{n} \widehat{D}_{m,\lambda }^{(k)}S_{2}(n,m) = \sum _{l=0}^{n}\binom{n }{l} \frac{\lambda ^{n-l}B_{l}}{(n-l+1)^{k}}.$$
From (2.17), we note that
\begin{aligned}[b] \frac{1}{\lambda t} \mathrm{Ei}_{k}(\lambda t) & = \frac{1}{t} \bigl(e^{t}-1\bigr) \sum_{m=0}^{\infty } \widehat{D}_{m,\lambda }^{(k)}\frac{1}{m!} \bigl(e^{t}-1\bigr)^{m} \\ & = \frac{1}{t}\sum_{m=1}^{\infty }m \widehat{D}_{m-1,\lambda }^{(k)} \frac{1}{m!} \bigl(e^{t}-1\bigr)^{m} \\ & = \frac{1}{t}\sum_{m=1}^{\infty }m \widehat{D}_{m-1,\lambda }^{(k)} \sum_{n=m}^{\infty }S_{2}(n,m) \frac{t^{n}}{n!} \\ & = \frac{1}{t}\sum_{n=1}^{\infty } \sum_{m=1}^{n}m\widehat{D}_{m-1, \lambda }^{(k)}S_{2}(n,m) \frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty } \Biggl( \frac{1}{n+1}\sum_{m=1}^{n+1}m \widehat{D}_{m-1,\lambda }^{(k)}S_{2}(n+1,m) \Biggr) \frac{t^{n}}{n!}. \end{aligned}
(2.19)
On the other hand,
\begin{aligned} \frac{1}{\lambda t} \mathrm{Ei}_{k}(\lambda t) = \frac{1}{\lambda t}\sum _{n=1}^{\infty } \frac{\lambda ^{n}t^{n}}{(n-1)!n^{k}} = \sum _{n=0}^{\infty } \frac{\lambda ^{n}}{(n+1)^{k}} \frac{t^{n}}{n!}. \end{aligned}
(2.20)
Therefore, by (2.19) and (2.20), we obtain the following theorem.
### Theorem 2.7
For$$n \ge 0$$, we have
\begin{aligned} \frac{\lambda ^{n}}{(n+1)^{k}} &= \frac{1}{n+1}\sum _{m=1}^{n}m \widehat{D}_{m-1,\lambda }^{(k)}S_{2}(n+1,m) \\ & = \frac{1}{n+1}\sum_{m=0}^{n-1}(m+1) \widehat{D}_{m,\lambda }^{(k)}S_{2}(n+1,m+1). \end{aligned}
## Higher-order degenerate Daehee numbers and polynomials
As an additive version of (2.14), we consider the degenerate Daehee polynomials of order r given by the following multiple integral on the unit cube:
\begin{aligned}[b] \sum_{n=0}^{\infty }D_{n,\lambda }^{(r)}(x) \frac{t^{n}}{n!} & = \biggl(\frac{\log (1+t)}{t} \biggr)^{r} \int _{0}^{1} \cdots \int _{0}^{1}(1+t)^{\lambda (x_{1}+\cdots +x_{r})+x}\,dx_{1} \cdots dx_{r} \\ & = \biggl(\frac{\log _{\lambda }(1+t)}{t} \biggr)^{r}(1+t)^{x}\quad (r \in \mathbb{N}). \end{aligned}
(3.1)
When $$x=0$$, $$D_{n,\lambda }^{(r)} = D_{n,\lambda }^{(r)}(0)$$$$(n \ge 0)$$, are called the degenerate Daehee numbers of order r.
From (3.1), we note that
\begin{aligned}[b] \sum_{n=0}^{\infty }D_{n,\lambda }^{(r)} \frac{t^{n}}{n!} & = \biggl(\frac{\log _{\lambda }(1+t)}{t} \biggr)^{r} = \frac{r!}{t^{r}}\frac{1}{r!}\bigl(\log _{\lambda }(1+t) \bigr)^{r} \\ & = \frac{r!}{t^{r}}\sum_{n=r}^{\infty }S_{1,\lambda }(n,r) \frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty }S_{1,\lambda }(n+r,r) \frac{r!n!}{(n+r)!} \frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty } \frac{S_{1,\lambda }(n+r,r)}{\binom{n+r }{n}}\frac{t^{n}}{n!}. \end{aligned}
(3.2)
Therefore, by comparing the coefficients on both sides of (3.2), we obtain the following theorem.
### Theorem 3.1
For$$n \ge 0$$, we have
\begin{aligned} D_{n,\lambda }^{(r)} = \frac{1}{{n+r \choose n}}S_{1, \lambda }(n+r,r)\quad (r \in \mathbb{N}). \end{aligned}
By replacing t by $$e_{\lambda }(t)-1$$ in (3.1), we get
\begin{aligned}[b] \sum_{k=0}^{\infty }D_{k,\lambda }^{(r)}(x) \frac{1}{k!}\bigl(e_{ \lambda }(t)-1\bigr)^{k} & = \biggl(\frac{t}{e_{\lambda }(t)-1} \biggr)^{r}e_{ \lambda }^{x}(t) \\ & = \sum_{n=0}^{\infty }\beta _{n,\lambda }^{(r)}(x)\frac{t^{n}}{n!}. \end{aligned}
(3.3)
On the other hand,
\begin{aligned}[b] &\sum_{k=0}^{\infty }D_{k,\lambda }^{(r)}(x) \frac{1}{k!}\bigl(e_{\lambda }(t)-1\bigr)^{k} \\ &\quad = \sum_{k=0}^{\infty }D_{k,\lambda }^{(r)}(x) \sum_{n=k}^{ \infty }S_{2,\lambda }(n,k) \frac{t^{n}}{n!} \\ & \quad = \sum_{n=0}^{\infty } \Biggl(\sum _{k=0}^{\infty }D_{k, \lambda }^{(r)}(x)S_{2,\lambda }(n,k) \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(3.4)
Therefore, by (3.3) and (3.4), we obtain the following theorem.
### Theorem 3.2
For$$n \ge 0$$, we have
$$\beta _{n,\lambda }^{(r)}(x) = \sum _{k=0}^{n}D_{k, \lambda }^{(r)}(x)S_{2,\lambda }(n,k).$$
By replacing t by $$\log _{\lambda }(1+t)$$ in (1.9), we get
\begin{aligned}[b] \biggl(\frac{\log _{\lambda }(1+t)}{t} \biggr)^{r}(1+t)^{x} & = \sum _{k=0}^{\infty }\beta _{k,\lambda }^{(r)}(x) \frac{1}{k!}\bigl( \log _{\lambda }(1+t)\bigr)^{k} \\ & = \sum_{k=0}^{\infty }\beta _{k,\lambda }^{(r)}(x)\sum_{n=k}^{ \infty }S_{1,\lambda }(n,k) \frac{t^{n}}{n!} \\ & = \sum_{n=0}^{\infty } \Biggl(\sum _{k=0}^{n}\beta _{k,\lambda }^{(r)}(x)S_{1, \lambda }(n,k) \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(3.5)
On the other hand,
$$\biggl(\frac{\log _{\lambda }(1+t)}{t} \biggr)^{r}(1+t)^{x} = \sum _{n=0}^{\infty }D_{n,\lambda }^{(r)}(x) \frac{t^{n}}{n!}.$$
(3.6)
Therefore, by (3.5) and (3.6), we obtain the following theorem.
### Theorem 3.3
For$$n \ge 0$$, we have
$$D_{n,\lambda }^{(r)}(x) = \sum _{k=0}^{n}\beta _{k, \lambda }^{(r)}(x)S_{1,\lambda }(n,k).$$
From (3.1), we note that
\begin{aligned}[b] \sum_{n=0}^{\infty }D_{n,\lambda }^{(r)} \frac{t^{n}}{n!}& = \underbrace{ \biggl(\frac{\log _{\lambda }(1+t)}{t} \biggr)\times \cdots \times \frac{\log _{\lambda }(1+t)}{t}}_{r\text{- times}} \\ & = \sum_{n=0}^{\infty } \biggl(\sum _{l_{1}+\cdots +l_{r}= n}\binom{n }{l_{1},\ldots l_{r}}D_{l_{1},\lambda }\cdots D_{l_{r},\lambda } \biggr)\frac{t^{n}}{n!}. \end{aligned}
(3.7)
By (3.7), we get
\begin{aligned} D_{n,\lambda }^{(r)} = \sum_{l_{1}+\cdots +l_{r}= n} \binom{n }{l_{1},\ldots l_{r}}D_{l_{1},\lambda } \cdots D_{l_{r},\lambda } \quad (n \ge 0). \end{aligned}
(3.8)
On the other hand, by (3.2), we get
\begin{aligned} \sum_{n=0}^{\infty }D_{n,\lambda }^{(r)} \frac{t^{n}}{n!} =& \biggl(\frac{\log (1+t)}{t} \biggr)^{r} \int _{0}^{1} \cdots \int _{0}^{1}(1+t)^{\lambda (x_{1}+\cdots +x_{r})}\,dx_{1} \cdots dx_{r} \\ = &\biggl(\frac{\log (1+t)}{t} \biggr)^{r}\sum _{m=0}^{\infty } \lambda ^{m} \frac{(\log (1+t))^{m}}{m!} \int _{0}^{1}\cdots \int _{0}^{1}(x_{1}+ \cdots +x_{r})^{m}\,dx_{1}\cdots dx_{r} \\ = & \frac{1}{t^{r}}\sum_{m=0}^{\infty } \lambda ^{m}\sum_{l_{1}+ \cdots +l_{r}= m} \binom{m }{l_{1},\ldots ,l_{r}} \frac{1}{(l_{1}+1)\cdots (l_{r}+1)}\frac{(\log (1+t))^{m+r}}{m!} \\ = & \frac{1}{t^{r}}\sum_{m=0}^{\infty } \lambda ^{m}\sum_{l_{1}+ \cdots +l_{r}= m} \binom{m }{l_{1},\ldots ,l_{r}} \frac{1}{(l_{1}+1)\cdots (l_{r}+1)}\frac{(m+r)!}{m!} \\ &{} \times \sum_{n=m+r}^{\infty }S_{1}(n,m+r) \frac{t^{n}}{n!} \\ = & \sum_{m=0}^{\infty }\lambda ^{m}\sum_{l_{1}+\cdots +l_{r}= m}\binom{m }{l_{1},\ldots ,l_{r}} \frac{1}{(l_{1}+1)\cdots (l_{r}+1)} \frac{(m+r)!}{m!} \\ &{} \times \sum_{n=m}^{\infty }S_{1}(n+r,m+r) \frac{t^{n}}{(n+r)!} \\ = & \sum_{n=0}^{\infty } \Biggl(\sum _{m=0}^{n}\lambda ^{m} \sum _{l_{1}+\cdots + l_{r}= m} \frac{{n \choose l_{1},\ldots ,l_{r}}}{(l_{1}+1)\cdots (1_{r}+1)} S_{1}(n+r,m+r) \frac{{m+r\choose r}}{{n+r \choose r}} \Biggr)\frac{t^{n}}{n!}. \end{aligned}
(3.9)
Therefore, by comparing the coefficients on both sides of (3.9), we obtain the following theorem.
### Theorem 3.4
For$$n \ge 0$$, we have
\begin{aligned}D_{n,\lambda }^{(r)} &= \sum _{l_{1}+\cdots +l_{r}= m}\binom{n }{l_{1},\ldots ,l_{r}}D_{l_{1},\lambda }\cdots D_{l_{r}, \lambda } \\ & = \sum_{m=0}^{n}\lambda ^{m}\sum_{l_{1}+\cdots +l_{r}= m}\binom{m }{l_{1},\ldots , l_{r}} \frac{S_{1}(n+r,m+r)}{(l_{1}+1)\cdots (1_{r}+1)} \frac{{m+r\choose r}}{{n+r \choose r}}. \end{aligned}
## Conclusion
In the spirit of [1], we studied the degenerate Daehee polynomials and numbers which were actually called the degenerate Daehee polynomials and numbers of the third kind and recently introduced by Jang et al. in [4]. We derived their explicit expressions and some identities involving them. Further, we introduced the multiple degenerate Daehee numbers and higher-order degenerate Daehee polynomials and numbers and deduced their explicit expressions and some identities related to them.
The possible applications of our results are as follows. The first one is their applications to identities of symmetry. For example, in [13] many symmetric identities in three variables, related to degenerate Euler polynomials and alternating generalized falling factorial sums, were obtained. The second one is their applications to differential equations from which we can derive some useful identities. For example, in [12] an infinite family of nonlinear differential equations, having the generating function of the degenerate Bernoulli numbers as a solution, were derived. As a result, an identity, involving the degenerate Bernoulli and higher-order degenerate Bernoulli numbers, were obtained. Similar things had been done for the degenerate Euler numbers. The third one is their applications to probability theory. Indeed, in [19] it was shown that both the degenerate λ-Stirling polynomials of the second and the r-truncated degenerate λ-Stirling polynomials of the second kind appear in certain expressions of the probability distributions of appropriate random variables.
Finally, it is one of our future projects to continue to study various degenerate versions of some special polynomials and their applications to mathematics, science and engineering.
We studied the degenerate Daehee polynomials and numbers which are different from the degenerate Daehee polynomials and numbers of the third kind introduced by Jang et al. [4].
## References
1. 1.
Carlitz, L.: Degenerate Stirling, Bernoulli and Eulerian numbers. Util. Math. 15, 51–88 (1979)
2. 2.
Dolgy, D.V., Jang, G.-W., Kim, D.S., Kim, T.: Explicit expressions for Catalan–Daehee numbers. Proc. Jangjeon Math. Soc. 20(1), 1–9 (2017)
3. 3.
EI-Desouky, B.S., Mustafa, A.: New results on higher-order Daehee and Bernoulli numbers and polynomilas. Adv. Differ. Equ. 2016, 206 (2016)
4. 4.
Jang, L.-C., Kim, W., Kwon, H.-I., Kim, T.: On degenerate Daehee polynomials and numbers of the third kind. J. Comput. Appl. Math. 364, Article ID 112343 (2020)
5. 5.
Jang, L.-C., Kim, D. S., Kim, T., Lee, H.: p-Adic integral on $$\Bbb {Z}_{p}$$ associated with degenerate Bernoulli polynomials of the second kind. Adv. Differ. Equ. 2020, Article ID 278 (2020)
6. 6.
Kim, D., Kim, T.: Idntities arising from higher-order Daehee polynomial bases. Open Math. 13(1), 196–208 (2015)
7. 7.
Kim, D.S., Kim, T.: A note on polyexponential and unipoly functions. Russ. J. Math. Phys. 26(1), 40–49 (2019)
8. 8.
Kim, D.S., Kim, T.: A note on a new type of degenerate Bernoulli numbers. Russ. J. Math. Phys. 27(2), 227–235 (2020)
9. 9.
Kim, D.S., Kim, T., Kwon, J., Lee, H.: A note on λ-Bernoulli numbers of the second kind. Adv. Stud. Contemp. Math. (Kyungshang) 30(2), 187–195 (2020)
10. 10.
Kim, D.S., Kim, T., Ryoo, C.S.: Generalized type 2 degenerate Euler numbers. Adv. Stud. Contemp. Math. (Kyungshang) 30(2), 165–169 (2020)
11. 11.
Kim, T., Jang, L.-C., Kim, D.S., Kim, H.Y.: Some identities on type 2 degenerate Bernoulli polynomials of the second kind. Symmetry 12(4), Article ID 510 (2020)
12. 12.
Kim, T., Kim, D.S.: Identities involving degenerate Euler numbers and polynomials arising from non-linear differential equations. J. Nonlinear Sci. Appl. 9, 2086–2098 (2016)
13. 13.
Kim, T., Kim, D.S.: Identities of symmetry for degenerate Euler polynomials and alternating generalized falling factorial sums. Iran. J. Sci. Technol. Trans. A, Sci. 41(4), 939–949 (2017)
14. 14.
Kim, T., Kim, D.S.: A note on type 2 Changhee and Daehee polynomials. Rev. R. Acad. Cienc. Exactas Fís. Nat., Ser. A Mat. 113(3), 2783–2791 (2019)
15. 15.
Kim, T., Kim, D.S.: Extended Stirling numbers of the first kind associated with Daehee numbers and polynomials. Rev. R. Acad. Cienc. Exactas Fís. Nat., Ser. A Mat. 113(2), 1159–1171 (2019)
16. 16.
Kim, T., Kim, D.S.: Degenerate polyexponential functions and degenerate Bell polynomials. J. Math. Anal. Appl. 487(2), 124017 (2020)
17. 17.
Kim, T., Kim, D.S.: Degenerate binomial coefficients and degenerate hypergeometric functions. Adv. Differ. Equ. 2020, Article ID 115 (2020)
18. 18.
Kim, T., Kim, D.S.: A note on central Bell numbers and polynomials. Russ. J. Math. Phys. 27(1), 76–81 (2020)
19. 19.
Kim, T., Kim, D.S., Kim, H.Y., Kwon, J.: Degenerate Stirling polynomials of the second kind and some applications. Symmetry 11(8), 1046 (2019)
20. 20.
Kim, T., Kim, D.S., Kwon, J., Lee, H.: Degenerate polyexponential functions and type 2 degenerate poly-Bernoulli numbers and polynomials. Adv. Differ. Equ. 2020, 168 (2020)
21. 21.
Kwon, J., Kim, T., Kim, D.S., Kim, H.Y.: Some identities for degenerate complete and incomplete r-Bell polynomials. J. Inequal. Appl. 2020, Article ID 23 (2020)
22. 22.
Kwon, J., Kim, W.J., Rim, S.-H.: On the some identities of the type 2 Daehee and Changhee polynomials arising from p-adic integrals on $$Z_{p}$$. Proc. Jangjeon Math. Soc. 22(3), 487–497 (2019)
23. 23.
Liu, C., Wuyungaowa, B.: Application of probabilistic method on Daehee sequences. Eur. J. Pure Appl. Math. 11(1), 69–78 (2018)
24. 24.
Liu, G.-D., Srivastava, H.M.: Explicit formulas for the Nörlund polynomials $$B_{n}^{(x)}$$ and $$b_{n}^{(x)}$$. Comput. Math. Appl. 51, 1377–1384 (2006)
25. 25.
Luo, Y.-N., Wuyungaowa, B.: Some combinatorial identities about Daehee sequences. J. Comb. Math. Comb. Comput. 108, 75–87 (2019)
26. 26.
Moon, E.-J., Park, J.-W., Rim, S.-H.: A note on the generalized q-Daehee numbers of higher order. Proc. Jangjeon Math. Soc. 17(4), 557–565 (2014)
27. 27.
Park, J.-W.: On the q-analogue of Daehee numbers and polynomials. Proc. Jangjeon Math. Soc. 19(3), 537–544 (2016)
28. 28.
Park, J.-W., Rim, S.-H., Kwon, J.: The twisted Daehee numbers and polynomials. Adv. Differ. Equ. 2014, 1 (2014)
29. 29.
Pyo, S.-S., Kim, T., Rim, S.-S.: Degenerate Daehee numbers of the third kind. Mathematics 6(11), 239 (2018)
30. 30.
Roman, S.: The Umbral Calculus. Pure and Applied Mathematics, vol. 111. Acsdemic Press, New York (1984)
31. 31.
Saif, M., Nadeem, R.: Evaluation of Apostol–Euler based poly Daehee polynomials. Int. J. Appl. Comput. Math. 6, Article ID 1 (2020)
32. 32.
Seo, J.J., Rim, S.H., Kim, T., Lee, S.H.: Sums products of generalized Daehee numbers. Proc. Jangjeon Math. Soc. 17(1), 1–9 (2014)
33. 33.
Simsek, Y.: Apostol type Daehee numbers and polynomials. Adv. Stud. Contemp. Math. (Kyungshang) 26, 555–566 (2016)
34. 34.
Simsek, Y.: Identities on the Changhee numbers and Apostol-type Daehee polynomials. Adv. Stud. Contemp. Math. (Kyungshang) 27, 199–212 (2017)
### Acknowledgements
We would like to thank the referees for their valuable comments and suggestions. Also, we would like to thank Jangjeon Institute for Mathematical Science for the support of this research.
Not applicable.
## Funding
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2017R1E1A1A03070882).
## Author information
Authors
### Contributions
TK and DSK conceived of the framework and structured the whole paper; DSK and TK wrote the paper; JK and HYK checked the results of the paper; DSK and TK completed the revision of the article. All authors have read and agreed to the published version of the manuscript.
### Corresponding author
Correspondence to Jongkyum Kwon.
## Ethics declarations
### Competing interests
The authors declare that they have no conflicts of interest.
## Rights and permissions
Reprints and Permissions
Kim, T., Kim, D.S., Kim, H.Y. et al. Some results on degenerate Daehee and Bernoulli numbers and polynomials. Adv Differ Equ 2020, 311 (2020). https://doi.org/10.1186/s13662-020-02778-8
• Accepted:
• Published:
• 11B83
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### Keywords
• Degenerate Daehee polynomials and numbers
• Multiple degenerate Daehee numbers
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https://www.physicsforums.com/threads/simplifying-complex-numbers.236204/ | # Simplifying complex numbers
• #1
908
0
## Homework Statement
Simplify $(1+i\sqrt{2})^5-(1-i\sqrt{2})^5$
## Homework Equations
$$z=a+bi$$
$$z=r(cos\varphi+isin\varphi)$$
$$tg\varphi=\frac{b}{a}$$
$$r=\sqrt{a^2+b^2}$$
## The Attempt at a Solution
$$(\sqrt{3}(arccos\frac{\sqrt{3}}{3}+iarcsin\frac{\sqrt{6}}{3}))^5-(\sqrt{3}(arccos\frac{\sqrt{3}}{3}+iarcsin\frac{-\sqrt{6}}{3}))^5$$
How will I get integer angle out of here?
$$arccos\frac{\sqrt{3}}{3} \approx 54.74^\circ$$
$$arcsin\frac{\sqrt{-6}}{3} \approx -54.74^\circ$$
Related Precalculus Mathematics Homework Help News on Phys.org
• #3
908
0
Yes, I know de Moivre's theorem, but I don't know how will I get integer at the end...
• #4
63
0
Why do you need an integer at the end? Is this a part of the question that hasn't been specified? ???
• #5
908
0
Ok.
$$\sqrt{3^5}(cos5*54.74^\circ+isin5*54.74^\circ)-\sqrt{3^5}(cos5*54.74^\circ-isin5*54.74^\circ)$$
$$9\sqrt{3}(0.065-0.997i)-9\sqrt{3}(0.065+0.997i)=9\sqrt{3}(0.065-0.997i-0.065-0.997i)=9\sqrt{3}(-2*0.997i)=-i17.946\sqrt{3} \approx -31.08i$$
And in my text book results: $-22i\sqrt{2}$, we both get same result, but the question is how they get integer numbers?
• #6
Defennder
Homework Helper
2,591
5
I can think of one possible way to get that: Expand the complex numbers out by binomial theorem and then simplify the expression. This would be very tedious, no doubt.
• #7
908
0
Defennder, I know that I can solve it like that, but it is far more complicated, and the possibility that you may miss some value is very big...
• #8
Hootenanny
Staff Emeritus
Gold Member
9,621
6
I think it was be best to put the two complex numbers into exponential form for the powers and then convert back to Cartesian to perform the subtraction.
• #9
tiny-tim
Homework Helper
25,832
251
Simplify $(1+i\sqrt{2})^5-(1-i\sqrt{2})^5$
Oh come on, guys!
(a + b)^5 - (a - b)^5 = … ?
• #10
86
0
By binom formula?
• #11
HallsofIvy
Homework Helper
41,833
961
Have you tried it?
• #12
Defennder
Homework Helper
2,591
5
Well actually he's asking for a quicker way to get the answer in terms of radicals apart from the binomial theorem or de Moivre's theorem
• #13
63
0
Oh come on, guys!
(a + b)^5 - (a - b)^5 = … ?
Tiny Tim is right to point this out. But the explanation for a general rule of a difference of this sort is in line, for learning purposes of course ;)
If you have an equation of the above kind e.g. (a+b)^n - (a-b)^n , an expansion shows that there will be n+1 terms for (a+b)^n and (a-b)^n. The difference of the two, however, eliminates all but the even terms: for these terms, the coefficients are doubled.
Let's look at an easier example, (a+b)^3 - (a-b)^3 .
Using the binomial theorem (by writing the coefficients as they would appear in Pascale's triangle and by ordering terms by increasing exponents of b and decreasing of a) we get
[a^3 + 3(a^2)(b)+3(a)(b^2) + b^2] - [a^3 - 3(a^2)(b)+3(a)(b^2) -b^3]
= 6 (a^2)(b)+ 2 b^3
As you can see, this is just twice the even-numbered terms in the expansion of (a+b)^3.
The case for (a+b)^5 is analogous.
This is a succinct way of arriving at the result.
• #14
86
0
Ahh... I understand now. So I should also use the binom formula, right?
• #15
tiny-tim
Homework Helper
25,832
251
Ahh... I understand now. So I should also use the binom formula, right?
Theofilius , you keep answering questions with a question …
(a + b)^5 - (a - b)^5 = … ?
… and don't answer with a question … !
• #16
86
0
$$-22i\sqrt{2}$$. I know that, but I should have do that with De Moivre's formula.
• #17
tiny-tim
Homework Helper
25,832
251
$$-22i\sqrt{2}$$. .
erm … no.
… I know that, but I should have do that with De Moivre's formula
eh? … but this is Physicsissuef's question, not yours!
What makes you think he has to use de Moivre?
• #18
86
0
Since I have same problem in my book. And I solve it correctly, why you say no?
• #19
908
0
Yes, since logically we need to solve this problem as simple as possible, but no problem.
• #20
tiny-tim
Homework Helper
25,832
251
oops! it is -22i√2. Sorry!
If you must do it by de Moivre, just put (1 + i√2) = r(cosθ + i sinθ), but leave putting the numbers in until the end.
Then you want r^5[(cos5θ + i sin5θ) - (cos5θ - i sin5θ)], = 2 i r^5 sin5θ.
You know r = √3, and tanθ = √2, so it's fairly easy to work out from that what sin5θ is.
(But the binomial method is probably a more straightforward way of calculating sin5θ, sin 7θ, etc)
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http://archive.org/stream/bioenglishcyclop06kniguoft/bioenglishcyclop06kniguoft_djvu.txt | # Full text of "English cyclopaedia, a new dictionary of universal knowledge"
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THE
ENGLISH CYCLOPAEDIA.
BIOGRAPHY.
The names of those living at the time of the continuous publication of the 'Unglith Cyclopaedia of Biography,' are preceded hy an asterisk.
THIRTY TYRANTS (OF ATHENS).
THIRTY TYRANTS (OF ROME).
THIRTY TYRANTS (of Athens). lu the year B.C. 404, when,
after the Peloponnesian war, Athens had fallen into the hands of
Sparta, through the treacherous designs of the oligarchical party, the
Spartans themselves did not interfere in any direct way with the
political constitution of Athens (Diodorus, xiv. 4), but , their negocia-
tions with Theramenes and others of the same party had convinced
them that even without their interference the democracy would soon
be abolished. In this expectation they were not disappointed, as this
was really the object of the oligarchical party. But as this party did
to Samos, was invited to attend the Assembly at Athens, in which the
question of reforming the constitution was to be considered. The
presence of Lysander and other Spartan generals with their armies,
and the threats that were uttered, silenced all opposition on the side
of the popular party, and on the proposition of Theramenes a decree
was passed that thirty men should be elected to draw up a new con-
stitution. (Xenophon, ' Hellen.,' ii. 3, 2.) Lysias (* in Eratosth.,' p.
126, cd. Steph.) gives a more satisfactory account of the proceedings
on that memorable day than Xenophon. These thirty individuals
were invested with the sovereign power of the republic. Theramenes
himself nominated ten, the Athenian ephors ten others, and the
election of the remaining ten was left to the people. The names of
the Thirty are preserved in Xenophon (* Hellen.,' ii. 3, 2). Their
government, a real reiga of terror, which fortunately did not last
more than one year, was called in Athenian history the year of anarchy,
or the reign of the Thirty Tyrants. From the moment that they had
thus acquired an apparently legal power, they filled the vacancies in
the senate and the magistracies with their own friends and creatures.
The new code of laws which they were to draw up was never made,
that they might not put any restraints upon themselves, and might
always be at liberty to act as they pleased. A similar board, consist-
ing of ten men, perhaps appointed by Lysander himself, was intrusted
•with the government of Piraaeus. The object of the tyrants was to
reduce Athens to the condition of an unimportant town, and to make
the people forget the greatness to which it had been raised by Themis-
tocles and Pericles. The splendid arsenal of Athena was sold and
pulled down, and several of the fortresses of Attica were destroyed.
To establish their tyranny the Thirty found it necessary to get rid
of a number of persons obnoxious to them. The fii'st that were put
to death were the sycophants, who during the time of the democracy
had contributed most towards its overthrow by their shameful prac-
tices ; and the senate, as well as every well-meaning citizen, was glad
to see the republic delivered of such a pestilence. The senate acted
in these trials as the supreme court of j ustice, and the Thirty pre-
sided in it. All the votes of the senators however were given openl/,
that the tyrants might be able to see which way each senator voted.
This mode of proceeding, though it was at first only directed against
individuals equally obnoxious to all parties, became alarming when all
the distinguished men, who had been imprisoned before the day on
which the new constitution was established, in order that they might
not frustrate the plans of the oligarchs by their opposition, were in like
manner sentenced to death. The apprehensions of the people were
but too well founded, and Critias, the most cruel among the Thirty,
gave sufficient indications that the Tyrants did not mean to go on
with the same moderation. That they might always have at hand an
armed force to support them, they sent an embassy to Sparta to ask
for a garrison to occupy the Acropolis. This was granted, and came
BIOG. DIV. VOL. VI.
under the comman i of Callibius as harmostes. His arrival rendered
the Thirty secure. They courted the Spartan harmostes in the most
obsequious manner, and he in return placed his troops at their dis-
posal for whatever purpose they might wish to employ them in estab-
lishing their dominion more firmly. The assistance to the senate in
the trials for political ofiences began to be dispensed with, and the
number of the unhappy victims increased at a fearful rate. Not only
persons who opposed or showed any dissatisfaction with the rule of
the Tyrants, but all who by their merits had gained favour with the
people, were regarded as dangerous persons, who, if they could choose,
would prefer a popular government, and were condemned to death in
a very summary manner. The reign of the Thirty now began to
display all its horrors, and no one could feel safe. To be possessed
of wealth, especially in the case of aliens, was sufficient to bring a man
to ruin, for the tj rants, independent of all political considerations,
began to murder for no other purpose than that of enriching them-
selves by the confiscation of the property of their victims. The
remonstrances of Theramenes against this reckless system of blood-
shed were not followed by any other consequences than that the
Thirty selected 3000 Athenians who wore to enjoy a kind of franchise,
and who could not be put to death without a trial before the senate.
The rest of the citizens were compelled to give up their arms, and
were treated as outlaws. By this expedient the Thirty hoped to
strengthen themselves, and to become more independent of the Spartan
garrison. The opposition of Theramenes to this arrangement involved
his own destruction. [Theramenes.] The horrors which were now
perpetrated became every day more numerous and fearful, and
numbers of Athenians fled from their native country to seek refuge at
Argos, Megara, Thebes, and other places, where they met with an
hospitable and kind reception. The tyrants soon began to be uneasy
at the crowds of exiles who thus gathered round the frontiers of
Attica, and applied to Sparta to interfere. The Spartans issued a
proclamation empowei'ing the Thirty to arrest the exiles in any part
of Greece, and forbidding any Greek state to interfere on their behalf.
This command was entirely disregarded by the Greeks, especially the
Thebaos, who even declared that the Athenian fugitives should be
received and protected in all the towns of Bojotia. Thebes, whose
mode of action was not dictated by a generous and humane feeling
towards the unhappy Athenians, but rather arose from jealousy of
Sparta, thus became the rallying point for a great number of exiles,
among whom Thrasybulus was the most enterprising. In what
manner the rule of the Thirty Tyrants was at last overthrown, and
the democratical constitution was restored at Athens, is related in the
article Thrasybulus.
(Xenophon, Hellen., ii. 8 ; Diodorus, xiv. 3, &c. ; Thirlwall ; Grote.)
THIRTY TYRANTS (under the Roman Empire). This name has
been given to a set of usurpers who sprung up in various parts of the
Roman empire in the reigns of Valerian 7a. D. 253-60) and Gallienus
(261-68). This appellation of the Thirty Tyrants, in imitation of the
Thirty Tyrants of Athens, is highly improper, and bears no analogy to
the Thirty of Athens. They rose in different parts, assuming the title
of emperor, in irregular succession, and were put down one after
another. Their number moreover does not amount to thirty, unless
women and children, who were honoured with the imperial title, are
included. Trebellius Pollio, who, in his work on the ' Triginta
Tyranni,' describes the adventures of each of them, has taken great
pains to make out that their number was thurty : there were however
B
THOLUCK, PRIEDRICH AUGUST.
THOMA.S.
only niaeteen real usurpers — Cyriades, Maorianus, Balista, Odenathus,
and Zenobia, in the eastern provinces ; Poethumus, Lollianus, Victori-
niis and hia mother Victoria, Marius, and Totricus, in Qaul, Britain,
and the western provinces in general ; Ingenuus, Regillianus, and
BureoluR, in Illyricum and the countries about the Danube ; Satumi-
nus, in Pontus ; Trebellianus, in Isauria ; Piso, in Thossaly ; ValenB,
in Acbaia; ^mihanus, in E^ypt : and Celsus, in Africa. The majority
of these usurpers were persons of low birth, without any talent or
virtue, and scarcely any one of them died a natural death. The best
among them wore Piso and Odenathus, and the latter, who maintained
himself at Palmyra, received the title of Augustus from the Roman
senate, and was enabled to bequeath his empire to his widow, the
celebrated Zenobia. (Trebellius Pollio, Trigiiita Tyranni ; Gibbon,
Uial. of the Decline and Fall, chap. x. ; Manso, Leben Constantin'a dot
Grouen, p. 433, &c.)
•THOLUCK. FRIEDRICH-AUGUST-GOTTTREU, ono of the
most distinguished of modem German theologians, was bom at Bi-es-
lau, on tho 30th of March 1799. It was at first intended that he
developed inclination for science led to his being placed in the uni-
versity of his native town, whence be removed in a short time to that
of Berlin. At Berlin, under the orientalist Von Diez, he diligently
studied the eastern languages, and, partly from association with a
circle of religious fiiends, and partly from the influence of Neander,
he devoted himself to theological studies, of which the first fruit was
' Wahre Weihe des Zweiflers,' which has been translated into English
by Ryland, and into French, Danish, Swedish, and Dutch, and of
which the seventh German edition, in 1851, changes the title to ' Die
Lehre vom Siinder und vom Versohncr * (The Doctrine of the Sinner
and of the Mediator). In 1824 he was made professor extraordinary
of theology in Berlin University. In 1825 he travelled at the expense
of the Prussian government to England and Holland, and on his return
in 1826 was made professor of theology iu the University of Halle.
Within a twelvemonth, his health failing, he was forced to quit Halle,
and received the appointment of chaplain to the embassy at Rome,
where be entirely recovered, and in 1829 returned to his professional
duties at Halle. Ha has ever since been indefatigably occupied by
bis lectures, by his personal intercourse with the students, and by his
writings ; and as a preacher in promoting a warm and truly devotional
Christianity united with a tempered and wise philosophy. His
writings have been very numerous, and are conbidered of great value,
not only by his own countrymen, but by English authors. Among
them are — ' Praktischen Commentar zu den Psalmen,' and ' Ueberset-
zung tmd Auslegung der Psalmen ' (Translation and Exposition of the
Psalms) ; ' Commentar zum Briefe an die Hebriier ;' ' Commentar zum
Romerbrief;' ' Philosophisch-Theologische Auslegung der Bergpre-
dicht ' (Exposition of the Sermon on the Mount) ; ' GlaubwUrdigkeit
der evangelische Geschichte' (Authenticity of the Evangelical History),
u work written in opposition to tho ' Leben Jesu ' of Strauss ; ' Pre-
digten iiber die Hauptstiicke dea Christlichen Glaubens und Lebens'
(Sermons on the Chief Phases of the Christian Faith and Life), ' Stun-
den der Andacht ' (Hours of Devotion) ; and ' Literarischen Anzeiger
iVir Christlicbe Theologie und Wissenschaft iiberhaupt' (Literary
Guide for Christian Theology and Science in General), in which he has
most clearly stated his theological views. Several of the preceding
works have been translated into English. His labours in the Oriental
tongues have also enabled him to produce ' Ssufismus, sive theosophia
Persarum pantheistica,' in 1821 ; the ' Bliitensammlung aus der Mor-
gonlandischen Mystiker' (Collection of Flowers from the Eastern
Mystics), 1825; and ' Speculative Triuitiitslehre des spatem Orients'
(Speculative Doctrines of a Trinity of the later Orientals), in 1826.
He has also contributed to theological history in his • Vfermischten
Schriften, grosstentheils apologetischen Inhalts,' 1839 ; 'Der Geist der
Lutherauischen Theologen Wittenbergs im 17 Jahrhundert,' 1852 ;
and ' Das akadomische Leben dea 17 Jahrhundert,' 1853-54, the last
forming at the same time the first division of a ' Vorgeschichte der
Rationalismus.'
THOM, JAMES, who acquired consi^ierable temporary celebrity as
a sculptor, was born in Ayrshire in 1799. He was brought up as a
stone-mason, and taught himself the art of sculpture. Some small
figures which he carved illustrative of the poetry of Bums secured
him a local fame, and he was tempted to try his chisel on others of
life-size. He accordingly produced in sandstone statues of Tam
O'Shanter and Souter Johnnie, which had a surprising ran of popu-
larity. After being successfully exhibited in Scotland they were
brought to London, where they proved equally attractive, and the
self-taught sculptor found himself for a time ' a lion.' He was com-
missioned to carve more than one repetition of these figures, and
small plaster models of them were produced in great numbers. There
is undoubtedly a good deal of humour and spirit in the figures, but
they are rude and iuartistiral in conception and execution, and their
excessive popularity was of evil influence upon the sculptor himself.
He afterwards executed a statue of ' Old Mortality ' and several other
works ; but he appeared to be falling into comparative obscurity
when, about 1836, the misconduct of an agent whom he had employed
to manage an itinerant exhibition of his 'Tam OShanter' and *01d
Mortality ' in the United States, led Thom to proceed to America.
Eventually he determined to remain in New York, where he found
considerable professional employment He also devoted some time to
architecture ; took a farm, on which he erected a house from his own
designs, and became a tolerably prosperous man ; but he seems to
have gradually abandoned the use of his chisel. He died at New
York on the 24th of April 1850. The original figures of Tam
O'Shanter and Souter Johnnie are placed in a building attached to
the Bums monument on the banks of the Doon ; there are copies of
them in England, and at Mr. Colt's, Paterson, New Jersey. His group
of ' Old Mortality ' stands at the chief entrance of the Laurel Hill
THOM, WILLIAM, the weaver-poet of Inverary, was born at
Aberdeen in 1799. At ten yeai-s of age, with barely the elements of
education, he was bound for four years apprentice to a weaver, and
during this time, as he narrates himself, " picked up a little reading
and writing," trying at the same time to acquire Latin, but being
" defeated for want of time." At the end of his apprenticeship he
was engaged at another factory, where he worked for seventeen years,
learned to play the German flute, and to know " every Scotch song
that is worth singing." He married about 1829, had a family, and after
some other removals settled for a time at Newtyle, near Cupar- Angus
in Forfarshire. He was there when the great commercial failures in
America occun-ed, one consequence of which was the cessation of
employment for the poor hand-loom weavers. With a wife and four
children, without work, in a neighbourhood where nearly all were as
poor as himself, and in a country where the poor-laws were not yet
mtroduced, the sufferings of the family were extreme, and in a cold
spring day of 1837 they resolved to set off to walk to Aberdeen, in
hopes that there he might procure employment. Of this journey
he has given a vivid and pathetic narrative. One child died on the
way. To obtain the means of progressing he had recourse to his flute,
which sometimes brought him a trifling gift, and he made his first
attempt at song-making in an address to his flute. This he had
printed, and by presenting a copy of it at the genteeler hou.ses pro-
cured sufficient to enable the family to i-each Aberdeen. He obtained
work, first in that town, and then at Inverury. In November 1840 his
wife, whose health had been weakened by her late sufferings, died in
childbed. His new affliction again drove him to poetry, realising
Shelley's assertion, that poets " learn in suffering what they teach in
song." He sent one of his compositions, * The Blind Boy's Pranks,' t-o
the ' Aberdeen Herald,' where it was inserted with much commenda-
tion. It attracted the notice of Mr. Gordon, of Knockespoch, a gentleman
in the neighbourhood, who relieved and patronised him. He had other
poems by him, which were produced and admired, and he was brought
to London, feasted at a public dinner, and received that sort of
patronage which had so injurious an influence in the case of Burns, a
patronage that only enhances the bitterness of the fate to which its
objects are almost inevitably consigned. Thom returned to Inverury,
resolving, he said, not to be too much elated by the applause he had
received, but it is difficult to withstand the seductions to which it
leads. He published in 1841 at Aberdeen, a small volume of poems,
' Rhymes and Recollections of a Hand-loom AVeaver,' which had but a
moderate success. His poetical powers were not great : the chief merit
of bis verses consists in the exact reproduction of feelings he had
himself experienced, with a melody of versification and a correctness
of taste remarkable in one of so extremely limited an education. He
married a second wife, was often subjected to the extremest need, and
at last died in great poverty in March 1850. His widow died in the
July following, and a subscription was raised of about 250^. for his
destitute children.
THOMAS, 0a>;uas, S^MH (in Greek Al^vfios : John, xi, 16 ; xx. 24),
one of the twelve apostles of Christ. (Matt. x. 3.) The Hebrew and
Greek names both signify a twin. St. Thomas is presumed to have
been a Galilean ; but no particulars of his birth-place or call to the
apostleship are given, and the first notice of him individually is iu
John xi. 40. Christ having expressed an intention of returning to
Judaea, in order to raise his friend Lazarus from the dead, Thomas
encouraged the other apostles to attend him, although he regarded
death as the certain consequence of this step. The impulsiveness of
character thus indicated was not long after very differently displayed.
Thomas happened to be absent when Chi'ist, after his resurrection,
first appeared to the apostles ; and when made acquainted with the
fact, he expressed an incredulity which could only be satisfied by tho
manual evidence of inserting his finger in the holes which the spear
and nails had made in the body of hjs crucified master. Eight days
after, when Christ again appeared, Thomas was present ; and the re-
action in his mind was very strongly expressed by him, when ho
was pointedly called upon by Jesus to stretch forth his hand and take
the desired proof. (John xxi. 24-29.) Thomas is not again mentioned
in the New Testament. Doubtless he laboured, like the other apostles,
in the propagation of the Christian doctrines : and ecclesiastical
traditions make him one of the apostles of tho Gentiles. It is alleged
that he travelled eastward, and laboured among the various nations
which then composed the Parthian empire. (Euseb., iii. 1 ; Rufin., x.
9 ; * Recognit.,' ix. 29.) There is a singular concurrence of Oriental
and Western testimony (which may be seen in Assemanni and Baro-
uius), to the effect that St. Thomas extended his labours farther east-
ward, and then southward, until he reached the coast of India and
Malabar, where, having exercised his apostolic labours with success.
THOMAS A KEMPIS.
THOMASIN.
he passed on to the ooaat of Coromandel ; and having made great
conversions to the faith in those parts, he proceeded over to some
coast on the east, called China (which may possibly have been the
country now called Cochin-China), and afterwards returned to Coro-
mandel, where, having suffered martyrdom, he was buried in the
mount since called St. Thomas's Mount.
In the quarters indicated there are Christian churches which bear
the name of St. Thomas, and claim him for their founder. If they
derive their existence as a church uninterrupted from the apostolic
age, this fact may be taken as a corroboration of the above traditions.
But if the effects which resulted among them from the labours of Mar
Thoma and other Nestorian missionaries, at the commencement of the
sixteenth century, were really an original conversion, or at least a re-
conversion, and not, as is often supposed, the revival of a fallen but
not extinct church — then this claim is to be regarded only as an echo
of the tradition which has always prevailed in the Syrian churches,
and which must be estimated by its intringic probability and value.
(Besides Assemanni and Baronius, see Tillemont, i. 397, sq. ; Cave's
Antiq. AjiostoUcce ; Winer's BiUisches Realworterhuch, art. Thomas;
Buchanan's Christian Researches ; Yeate's Indian Church History ; and
Principal Mill's Letter to the Society for the Propagation of the Gospel
(July 29, 1822). inserted in Christian Ilememhrancer for Nov., 1823.)
THOMAS A KEMPIS. [Kempis.]
THOMAS AQUI'NAS. [Aquinas.]
THOMAS, ANTOINE LE'ONARD, was born at Clermont in
Auvergne, on the 1st of October 1732. His father, it has been gene-
rally believed, died while Thomas was an infant, leaving a widow with
three sons and a daughter. The eldest son, Joseph Thomas, who
embraced the clerical profession, died in 1741 : he composed a
dramatic piece, entitled ' Le Plaisir,' which was acted with success in
1740. The second, Jean Thomas, died in 1755, professor in the
college of Beauvais : he published some Latin verses, and introduced
into his college an improved method of teaching Latin. It appears
therefore that the taste for literature was common to the whole
family.
Antoine Leonard was educated at home till he had completed his
ninth year, and was then sent to prosecute his studies at Paris, where
his brotliers preceded him. In a letter which he addressed, in 1767,
great pains with his education. They were an attached family :
Antoine retained all his early devotion for his mother till her death
in 1782 ; and his sister, the only member of the family who survived
him, lived with him till his death.
Antoine Leonard Thomas distinguished himself at the university.
In 1747 he carried off two of the prizes distributed in his class in the
college of Duplesf ia : in 1748 and 1749 he studied rhetoric in the
College of Lisieux, and obtained four prizes : from October 1749 to
August 1761, he studied philosophy with equal distinction, at first in
the College of Lisieux, subsequently in that of Beauvais. AVhen he
finished his university career, bis friends wished him to study for the
bar, and he did so far comply with their desire as to attend law classes
and the office of a solicitor. This continued till the death of his
second brother, 1755, at which time he had retired, apparently on
account of his health, which was always infirm, to his native district.
A short time after he accepted the offer of a professorship in the
College of Beauvais. He continued to discharge the duties of his
appointment till 17G1, when, finding them injurious to his health,
ho resigned, and was appointed private secretary to the Due de
Prasliu.
Thomas commenced his career as author in 1756 by publishing
'Reflexions Philosophiques et Littdraires sur le Poeme de la Religion
Naturelle.' This was throwing down the gauntlet to the whole school
of Voltaire : the patriarch himself took no notice of the publication,
and Grimm spoke of it as the work of ' a silly lad just escaped from
the school of the Jesuits.' In the same year Thomas addressed an
ode, full of hyperbolical compliments, to Sechelles, controller-general
of fiuiince : the flattery was successful; it obtained from the minister
an addition to the revenues of the college. In 1757 Thomas composed,
on the occasion of the great earthquake at Lisbon, a ' Memoire sur les
Causes des Tremblemens de Terre,' which was crowned by the
Academy of Rouen. In 1759 he published ' Jumarville,' a poem in
four cantos, on the death of a French officer, killed, as the French
alleged, under circumstances of peculiar atrocity, in the war between
the French and English, in the backwoods of America. Freron praised
this poem in the ' Annee Litteraire,' a tribute of thanks to the young
author who had ventured to attack Voltaire. These early works of
Thomas are remarkable only for their turgid style, commonplace ideas,
and for the eagerness of the author to avail himself of the popular
topic of the day.
prize-essays of its members more popular, began to propose the dloges
of great men as the subjects. Thomas entered the lists three suc-
cessive years, and was successful every time. His 'Eloge de Maurice,
Comte de Saxe,' was crowned in 1759; his 'Eloge de Henri Frangois
d'Aguesseau,' in 1760; and his 'Eloge de Rdnd du Quay-Trouin,' in
1761. In 1760 he also competed for the prize of poetry: his 'Epitre
an Peuple ' was declared next in merit to the poem of Marmontel, to
which the medal was assigned. In these compositions a marked
improvement can be traced. There is no greater originality of thought
than in his first productions — nothing of genius in them ; but more
matter, more of artibtical finish, and less of boyish inflation of style.
The connection with the Due de Praslin was less advantaceous to
Thomas than it promised to be at the outset The duke procured for
him the sinecure appointment of secretary-interpreter to the Swifs
cantons, But a vacancy occurring soon after in the Academy, this
minister, who had a personal quarrel witli Marmontel, sought to
obtain it for hia secretary. Thomas had the magnanimity to refuse
the appointment, urging the superior claims of Marmontel. This act
of honesty lost him the favour of the Duo de Praslin, and closed the
career of office which was opening to him. The admission to the
Academy was not however long deferred. He delivered his inaugural
address to that body on the 22nd of January 1767.
Between 1761 and 1767 he composed — ' Eloge de Sully,' crowned in
1763; 'Eloge de Descartes,' crowned in 1765; in 1766, 'Eloge de
Louis, Dauphin de France,' composed and published at the request of
the Comte d'Angiviller ; and his inaugural discourse. In October
1767, his opera of 'Amphion ' was brought out, but without success.
Thes» works are all characterised by a progressive improvement in
execution. They differ also from his juvenile productions in an
attempt to adopt the sparkling and antithetical style of the Encyclo-
pasdists, and in the complete approbation of their bold satirical tone
in respect to politics, although much of the author's juvenile respect
for religion remained with him to the last. As a natural consequence
of the change, Grinm had by this time begun to praise Thomas, and
complimentary letter on the 'Eloge de Descartes,' but had on the
other hand remarked to his friends that they ought now to substitute
the word galithomas for galimathias : Diderot continued implacable.
It was rumoured that the court, enraged at the free strain of the
' Epitre au Peuple,' and the sarcasms laimched against itself and the
feudal system in the ' Eloge du Dauphin,' threatened the liberty of
Thomas.
The principal publications of Thoma.?, from the time of his admit'
sion into the Academy till his death, are — ' Eloge de Marc Aur61e,'
director of the Academy, to the inaugural discourse of the archbishop
of Toulouse, also in 1770. 'Essai sur le Caract&re, lea ^locurs, et
I'Efiprit des Fommes, dans tons les Siecles,' 1772. 'Essai sur les
Eloges ; ou I'Histoire de la Littdrature et de I'Eloquence appliqudes ^
ce genre d'Ouvrage,' published in 1773, in an edition of his collected
works. Ho commenced a poem on the Czar Peter I.; but only four
books and part of a fifth were completed at the time of his death.
The increased technical skill of the author continues to show itself
in these works; but the increased boldness of hia attempts serves
also to show the natural meagreness and feebleness of his genius. Ho
was utterly devoid of impassioned imagination. His ' Eloge de Marc
Aurele ' is an attempt to personify a Stoic of the age of that emperor :
it is alike deficient in interest and dramatic truth. His essay on the
character and manners of women is a collection of passages which
would have swelled his didactic essay on 'dloges' to too great a bulk.
It was said at the time that this panegyrical essay on the sex pleased
them leas than the vituperations of Rousseau. No wonder the treatise
of Thomas is cold and uuimpassioned ; it was forced work ; but the
ravings of Rousseau are the scoldings of a jealous man who has been
anxious but unable to please. The treatise on ' dloges ' is a worthy
consummation of the authors labours in that empty and artificial
branch of literature which has all the falsehood of oratory, without
the interest which attaches to the eloquence of the bar or senate from
its power of producing great practical effects. The partially completed
poem of ' Tne Czar' is sensible and the versification smooth, but the
four books are four separate jioems, ia the manner (though not so
good) of Goldsmith's 'Traveller.' They never cculd have been made
parts of an epic.
Thomas died on the 17th of September 1785. His health, always
delicate, had been undermined by incessant study. Thomas was a
mere echo of the society by which he was surrounded. He took hia
colouring in youth from his preceptors, most of whom were eccle-
siastics ; in after-lifo, from the sceptical literary conversation of the
saloons of Paris. His dloges are his most characteristic works, a kind
of composition too inaccurate to have value as history, too cold and
remote from the real business of life to impress as oratory. Ho stands
however high among his class of writers. The high finish and some
of the brilliancy of the French school cannot be denied him ; though
for this he was indebted quite as much to the company he kept as to
natural talent, or even hia unquestionable painstaking.
{CEuvres de M. Thomas, Paris, 1792; (Euvres Posthumes de M.
Thomas, Paris, An x. (1802) ; ' Sketch of Thomas,' by Saint Sunn, in
the Biographic Universelle.)
THOMASIN, or TOMASIN, surnamed Tirkeliire, Cliir, or Zerkler,
a German poet of the 13th century. He was a native of the Italian
province of Friuli, now the Austrian province of Udine, and was born
about 1186. Being thus an Italian by birth, he wrote in his earlier
days an Italian work, probably a didactic poem, ' On Courteous
Manners,' which is no longer extant In the course of 1216, when ho
had just reached his thirtieth year, he wrote in the space of ten
months a great didactic poem in German, which from his native
THOMASIUS, CHRISTIAN.
THOMASIUS, CHRISTIAN.
country he colled 'The lUlian Guest' (Der Wclscbe QastV and which
consiHts of ten books. This poem, of which there exist many excellent
manuBcripts, ia one of the moat splendid productions of German
literature during the 13th centurj', and, although the author is a
foreigner, the work breathes throughout a pure German spirit, and
displays all the depth and intensity of German thought and feeling.
In the beginning of bis poem Thomasiu admits that be is not a perfect
master of the language which be used ; but still the peculiarities are
so few and slight, that it requires a profound knowledge of the old
German language to discover the foreigner. Eschenburg therefore
supposes that tho author's statement respecting bis native country is
a mere fiction. But this supposition, as well as another, that the
' Italian Guest' is merely a German translation of the Italian work
' On Courteouj> Manners,' is without foundation, and contradicted by
numerous passagc.s of the former work. The object of this poem is
to sliow in what virtue, piety, and good conduct consist, and why man
should strive after them. It shows that a remarkable progre.-s bad
taken place in the mind of Thomasiu during the interval between the
composition of tbo Italian and that of the German work. In the
former, as he himself states, bo b<ad proceeded from the idea that
courteous conduct and nobility of birth were always combined with a
noble mind, or, in other words, that the changeable rules respecting
good manners were of greater value tbau the eternal law of morality
which is implanted in every man's heart. This prejudice is altogether
given up in his German poem, where he declares that a man is foolisli
who tliioks himself great because he is of noble birth and possesses
courteous manners, and that it is only a man's heart and real
character that make him worth anything. Virtue with him is now a
fundamental principle, and not a mere expedient. He describes virtues
and vices, and their respective consequences, with a truly Socratic
spirit and dignity. Thomasiu was well acquainted with the history
of antiquity, and it is among the ancients that he found his best
models of really virtuous men. The whole poem is a sublime and
altogether practical system of morality : it is a philosophy iu the garb
of poetry and occasionally embellished by figurative language. But
he does not write in the spirit of any particular school; his object is
iu general to instruct man on matters concerning bis physical and
spiritual welfare.
This masterpiece of early German poetry and philosophy has never
yet been published entire. Fragments of it are printed in Escben-
burg's 'Denkmaler Altdeutscber Dichtkunst,' p. 121, &c. ; compare
Gervinus, ' Gescbichte der Poetischen National Literatur der Deut-
Bchen,' vol. i. p. 456, &c.
THOMA'SIUS, CHRISTIAN. The real name of this author is
Thomas, and in the works which be published in his mother tongue
he always calls himself Christian Thomas. He was born at Leipzig,
on the 12th of January 1655, and was the son of Jacob Thomasius
(1622-1684), a diRtiuguished professor of philosophy, and some time
rector of the celebrated Thomasschule at Leipzig, under whose
auspices Leibnitz was educated. The education of Christian Thoma-
sius was conducted by his father, whose knowledge of philosophy and
its history gave bis mind at an early age a decided turn. Christian
had scarcely attained bis fourteenth year when be was found suffi-
ciently prepared to enter the university. In his sixteenth year be
obtained the degree of Bachelor of Arts, and the year after that of
Master of Arts. The chief subjects of his studies were philosophy
and law, more especially the law of nature, which he regarded as the
basis of all other laws. Tho instruction of his father and bis own
experience at the university bad convinced him that the methods
of teacbmg then followed were pedantic and deficient, and be deter-
mined to remedy these defects as much as was in his power. In 1675
he went to Frankfurt-on-the-Oder, where be began a course of lectures
on law, but they do not appear to have been well received by his
colleagues, and iu 1679, after having obtained the degree of Doctor of
Laws, he left Frankfurt, and made a literary journey to Holland. Ou
returning to Leipzig he commenced the practice of the law. But
this occupation did not ofiFer suflScient scope for him, and he again
most beneficial reforms. The law of nature, which had until then been
almost entirely neglected in the universities, continued to be the prin-
cipal subject of bis studies. The older professors, who found them-
selves disturbed in their routine of teaching by the energy and
boldness of the young man, began to clamour against him. So long
as his father lived, violent outbreaks were prevented, partly because
he restrained his son's eagerness for reforms, and partly because the
other professors esteemed him too much to hurt bis feelings by open
attacks upon bis son. When however bis father died, in 1684, the
bitterness and boldness with which young Thomasius attacked anti-
quated prejudices of all kinds together with their champions, involved
him in numerous disputei?. The enmity was not only provoked by
the matter and the manner of bis teaching, but also by several publi-
cations which tended to destroy established opinions. One of them,
on polygamy, especially gave great offence ; and he asserted that poly-
gamy was at least not contrary to any law of nature.
Up to this time it had been the general custom in all German
universities to deliver lectures in Latin, and to make all public
announcements of them in the same language. In the year 1687
ThomasiuB published his programme in German, and announced that
he would deliver a course of lectures in German, and on a subject which
appeared altogether foreign to a university— viz. on the manner in
which the Germans should follow tho example of the French (' Dis-
cours, welcher Gestalt man donen Franzosen im gemeinen Leben und
Wandel nachahmen soil,' 4to, published at Leipzig, 1687.) This
daring innovation was regarded by his colleagues as a perfect heresy,
though, after the example was once set, it was gradually followed by
other professors, until it became the universal practice in all German
universities to lecture in German. It was a necessary consequence of
this that books of a scientific character now began to be written in
German. Notwithstanding both the open and secret attacks to
which Thomasius had thus exposed himself, he continued to combat
prejudice, pedantry, and whatever be regarded as error. He was un-
sparing in his censure, which was usually combined with wit and satire,
and even bis former teachers did not escape. In tbo year after, 1688, he
established a German Monthly Review, under the title ' Freimiithige,
jedoch vernunft- und gesetzmiissige Gedanken iiber allerhand, fiirnem-
lich aber neue Biicher,' which he conducted from 1688 till 1690, and
which gave him immense influence in all parts of Germany, and the
means of chastising his enemies. His enemies in their turn tried
every means to avenge themselves ; and although Thomasius at first
succeeded in averting the danger that was gathering around him, yet
the disputes became daily more vehement and serious, especially with
two divines, Pfeifer and Carpzovius, who charged him with atheism.
The theological faculty of Leipzig was likewise gained over to their
side. H. G. Masius, court preacher to the king of Denmark, who had
been rather severely dealt with by Thomasius in his Journal, and who
manner, persuaded the king of Denmark to have all the published
parts of Thomasius's Journal burnt in the market-place of Copen-
hagen by the hangman, 1689. Such proceedings in a foreign country
were treated by Thomasius with contempt ; but the storm was gather-
ing over his bead. In the same year he became involved in disputes
with the Pietists, and also came forward to justify marriages between
two persons of different religions, which enraged the divines of Witten-
berg to such a degree, that the chief consistory was induced by
various charges which were made against him to issue an order for the
apprehension of Thomasius, He escaped the danger and fled to
Berlin, where be met with a kind reception and the protection of
Frederick III., the great elector of Brandenburg (afterwards King
Frederick I.) who not only permitted him to settle at Halle, but also
place. He began bis lectures here in 1690, and met with the same
approbation on the part of the students as at Leipzig ; and the increase
in the number of students induced the elector in 1694 to found the
University of Halle, in which he appointed Thomasius professor of juris-
prudence, and conferred upon him the title of councillor, with a salary
of 500 thalers. In this new position too Thomasius continued to be
annoyed by numerous disputes, partly with his former adversaries
and partly with others. In the year 1709 he had the satisfaction to
receive an invitation to the chair of jurisprudence iu the University of
Leipzig, which however be refused. King Frederick I. of Prussia,
pleased with the determination of Thomasius not to leave his service,
rewarded him with the title of privy-councillor. In 1710 Thomasius
was elected rector of the University of Halle, and dean of the faculty
of jurisprudence. He died on the 23rd of September 1728, in the
seventy-third year of his age.
If ever a man exercised an influence upon his age and country
which will extend to the latest posterity, it is Thomasius. He was
one of the few men, like Luther and Lessing, who now and then rise
up iu a nation, give it an impulse, and determine its course. At the
time when Thomasius began to make himself known, philosophy and
theology were studied and taught in such a manner that it was evident
that the spirit which had been created by the Reformation would soon
vanish altogether. All philosophical and scientific works were written
in Latin, which formed an inadequate medium for communicating
new thoughts and ideas, which were frequently crippled aud imperfect
on that account, or the language itself was barbarous. In the uni-
versities also Latin was the ordinary language for communicating
knowledge, which thus remained in the exclusive possession of a small
number, and without influence upon the nation at large. Thomasius
prepared the way for better things, first by communicating knowledge
in bis native language, and by extending the sphere within which
speculation had until then been carried on. At the same time he
urged the necessity of writing in a clear and intelligible style, which
many of his countrymen in recent times have greatly neglected. His
own style, though not often pure, is precise and vigorous. As in
places of learning Thomasius destroyed old prejudices and pedantry,
he also boldly combated superstition and hypocrisy in the affairs of
common life, such as the belief in ghosts, spectres, and witchcraft ;
and it is almost entirely owing to his exertions that trials for witch-
craft and torture were abolished iu Germany. In reference to this
Frederick the Great says of Thomasius, "He denounced trials for
witchcraft so loudly, that persons began to be ashamed of them, and
from that time tho female sex has been permitted to grow old and die
in peace." All this would alone be sufficient to immortalise bis name,
even if he had no claim to it by what he did in philosophy. Here he
indeed found things in such a state, that it required all his energy to
D
TflOMOND, THOMAS.
THOMPSOir, WILLIAW.
10
clear the field from the weeds with which it was overgrown, before it
was fit to receive the seed, and accordingly his philosophy is more of a
destructive than of a constructive character. But in tliia negative
■way he lias done incalculable service to his nation, and Frederick the
Great justly says, that among all the philosophers of Germany, none
have contributed more to render its name illustrious than Leibnitz
and Thomasius.
The number of works of Thomasius is considerable. Besides those
mentioned above, the following must bo noticed : — ' Einleitung zu der
Vemunftlehre, worinnen durch eine leichte, und alien verniinftigen
Menschen, waserlei Standes oder Geschlechts sie seyn, verstiindliche
Mauler, der Weg gezeiget wird, ohne die Syllogistica, das Walire,
Wahrseheinliche und Falsche von einander zu entscheiden und
neue Wahrhoiten zu erfinden.' 8vo, Halle, 1691. The fifth and lost
edition of this work appeared at Halle, 8vo, 1719 ; it was tho first
readable book that had ever been produced in Qermauy on logic. ' Von
der Kunst verniinftig und tugendhaft zu lieben, als dem einzigen Mittel
zu einem gliickseligen, galanteu, und vergniigten Leben zu galangen,
oder Einleitung der Sittenlehre,' &o., 8vo, Halle, 1G92 ; an eighth edition
of it appeared in 1726. This work contains a system of ethics better
than any that had appeared before him. ' Historic der Weisheit und
Thorheit,' in three parts, Svo, Halle, 1693. 'Weitere Erliiuterung
durch unterschiedene Exempel, anderer Menschen Gemiither kennen
zn lernen,' Svo, Halle, 1693, reprinted in 1711. ' Der Kern wahrer und
niitzlicher Weltweisheit,' 8vo, Halle, 1693 : this is a translation of
Xenophon's ' Memorabilia of Socrates,' which Thomasius strangely
enough took from the French translation of Charpentier, although he
himself was well acquainted with the Greek. ' Versuch vom Wesen
des Geistes, oder Grundlehren die einem Studioso Juris zu wissen und
auf Universitaten zu lernen nothig sind,' 8vo, Halle, 1699, reprinted in
1709. ' Ernsthafte aber doch muntere und verniinftige Gedanken und
Erinnerungen iiber allerhand auserlesene juristische Hiindel,' 4 vols.,
Halle 1720-21. His miscellaneous and smaller essays appeared in a
collection under the title ' Kleine Deutsche Schriften mit Fleiss zusam-
mengetragen,' 8vo, Halle, 1701. A complete list of his works is given
in Luden's ' Christian Thomasius nach seinen Schicksalen und Schriften
dargestellt,' with a preface by Johannes von Miiller, Svo, Berlin, 1805 ;
and in Jorden's ' Lexikon Deutscher Dichter und Prosaisten, vol. v.,
p. 37—69.
THOMOND, THOMAS, an architect who practised at St. Petersburg,
and held the rank of a major in the Russian service, was a native of
France, and born at Nancy, on the 21st of December 1759. Scarcely
had he completed his professional education at Paris when the
revolution rendered it unsafe for him (he and his family being
royalists) to remain in the country, and he accordingly emigrated to
llussia, where he at first supported himself by the productions of his
pencil, which not only found purchasers, but made him favourably
known to the St. Petersburg public. The taste he displayed in archi-
tectural subjects led at length to his being employed by the govern-
ment in that branch of art which he had originally intended to follow,
and one of the first works of any importance intrusted to him was
the Great Theatre (erected by tho German architect Tischbein,
1782-83), which he was commissioned to improve and partly remodel
in 1804. Although not altogether free from the peculiarities of the
.to that structure is one of the noblest pieces of architecture in the
northern capital of Russia, and, of its kind and date, in Europe. Had
he executed nothing else, that alone would have entitled him to rank
higher in his profession as an artist than many who owe their celebrity
as much to the number as to the merit of their works. But he had
also the opportunity of displaying his taste and ability in another very
striking public edifice at St. JPetersburg, namely, the Imperial Birzha,
or Exchange, erected by him between the years 1804 and 1810, which
is an insulated structure (about 256 feet by 300 feet) of the Roman
Doric order, peripteral and decastyle at each end, although without
pediments, and having altogether 44 columns. Situated at the
southern point of the Vassilievskii Island, immediately facing the
Neva, it stands in the centre of a spacious plotchad, or ' place,' upon a
rich architectural terrace, which sweeps out so as to form a semicir-
cular esplanade in front, at each extremity of which is a flight of
steps leading down to the river, and a massive rostral column 120 feet
high. Taken altogether, the architectural combination thus produced
is exceedingly picturesque, and may be said to be unique.
Thomond also erected some private mansions and other buildings at
St. Petersburg, the mausoleum of the Emperor Paul at Pavlovska, the
theatre at Odessa, and the Pultava monument. In 1808 he published
some of his buildings and architectural designs in a quarto volume,
very unsatisfactorily executed however ; and he also wrote a treatise
on painting, an art to which he was greatly attached. He died on the
23rd of August 1813. (Kukolnik, in Khudozhedvennya Oazeta, 1837.)
THOMPSON, SIR BENJAMIN. [Rumford, Count.]
* THOMPSON, MAJOR-GENERAL THOMAS PERRONET, was
born in 1783, at Hull in Yorkshire. He received his early education
at the Hull grammar-school, of which the Rev. Joseph Milner was
then head-master. In October 1798 he was entered of Queen's College,
Cambridge, and in 1802 took his degree of B.A. He soon afterwards
entered the navy as a midshipman, but left it for the army, in which
he became a second lieutenant, Januaiy 23, 1806, and in 1807 served
in the Rifle Brigade in the attack on Buenos Ayrea. On the 2lBt of
January 1808 he became lieutenant, and in the same year was sent out
to the colony of Sierra Leone as governor. In 1812 he returned to
active service in the array. In 1814 he served with the 14th Light
Dragoons, and was engaged in the battles of Nivelle, Nive, Orthes, and
Toulouse, for his services in which ho received the war-medal with
four clasps. He attained the rank of captain on the 7th of July 1814,
and from 1815 to 1819 was engaged in the Pindaree and other cam-
paigns in India as captain of the 17th Light Dragoons. In 1819 be
served in the expedition to the Persian Gulf, under Sir William Grant
Keir, as secretary and Arabic interpreter, and was for a time political
agent there.
In 1821 Captain Thompson returned to England, and attained the
rank of major on the 9th of June 1825. In the meantime be had
become acquainted with Jeremy Bentham and Dr. Bowring (now Sir
John Bowring), and was a contributor to the ' Westminster Review,'
of which he afterwards became one of the proprietors. He soon dis-
tinguished himself as one of the most powerful of the opponents of
the system of protection of native industry, and in his ' Corn-Law
Catechism," first published in 1827, stated with great clearness of
reasoning and vivacity of illustration the leading arguments which
were afterwards successfully employed by the Anti-Corn-Law League
to overthrow the restrictive laws on the importation of wheat and other
grain. [Cobden, Richard.] The Catechism was published under the
title of ' Catechism on the Corn-Laws, with a List of the Fallacies
the " Westminster Review," No. 23, with a Collection of Objections
and Answers; by a Member of the University of Cambridge,' Svo,
15th edition, 1831. He also published a 'Catechisrn on the Currency,
by the Author of the Catechism on the Corn-Laws,' 8vo, 3rd edit.,
1848. On the 24th of Februaiy 1829 Captain Thompson became
lieutenant-colonel, unattached, and was placed on half-pay. He con-
tinued the assiduous and unflinching advocate of liberal policy in the
' Westminster Review,' in pamphlets, and in newspapers, and was an
active supporter of the parliamentary reform movement by speeches
as well as by his writings. Colonel Thompson's investigations how-
ever were not confined to questions of political and social reform. In
1829 he published an * Enharmonic Theory of Music,' which be repub-
lished in 1850 under the title of 'Theory and Practice of Just Intona-
tion, with a View to the Abolition of Temperament, as illustrated in
the Description and Use of the Enharmonic Organ, presenting the
Power of executing Avith the simple Ratios in Twenty Keys, with a
Correction for Changes of Temperature ; built by Messrs. Robson for
the Exhibition of 1851 ; with an Appendix tracing the Identity of
Design with the Enharmonic of the Ancients,' 12mo. In 1830 Colonel
Thompson published a small work entitled ' Geometry without
Axioms.'
Colonel Thompson was returned to parliament as member for the
borough of Hull on the 20th of June 1835. He was not returned in
the next election, and was out of parliament till he was returned for
Bradford in Yorkshire. He was not returned to the last parliament,
but was returned to the present, in March 1857, when he was again
elected for Bradford. He attained the rank of major-general on the
20th of June 1854.
Colonel Thompson has published an edition of his collected works,
under the title of * Exercises, Political and Others, by Lieut-Colonel
T. Pcrronet Thompson, consisting of Matter previously published
with and without the Author's name, and some not published before,'
6 vols. 12mo, 1843.
THOMPSON, WILLIAM, a celebrated Irish naturalist. His father
was an Irish linen merchant at Belfast, and William, his eldest son,
was born on the 2nd of November 1805. As his father destined him
for a commercial life, he received such an education as was supposed
to fit him for that pursuit. In 1821 he was apprenticed to a firm in
the linen business at Belfast. Although at this time he had acquired
no taste for natural history, he soon took an interest in this subject
from making excursions with a fellow apprentice who possessed a
copy of Bewick's 'British Birds,' and a passion for collecting and
stuffing birds. For several years he was hardly more than an amateur;
but in 1832 circumstances occurred which induced him to give up
business, and from that time he devoted himself in earnest to natural
history. Although birds were his favourite study, he took an
interest in all kinds of animals and plants, and eventually there
were few Irish minerals, plants, and animals, with which he was not
cognisant. He first became known as a naturalist by his contribu-
tions to the ' Proceedings ' of the Zoological Society of London, on
the natural history of Ireland. The names of some of tliese early
contributions indicate the direction of his mind ; 'Catalogue of Birds
new to the Irish Fauna;' 'On some Vertebrata new to the Irish
Fauna;' 'On some rare Irish Birds;' 'On the Natural History of
Ireland, with a description of a new Genus of Fishes ; ' ' On the Irish
Hare.' He also prepared to lay before the meeting of the British
Association for the Advancement of Science, held at Glasgow in 1840,
a ' Report on the Fauna of Ireland, Division Vertebrata.' This was
not a mere enumeration of the vertebrate animals of Ireland, or an
account of their comparative scarcity and abundance, but an ^^PO^i-
tion of the number of species in Ireland, the most western la°d cf
Europe, compared with other British and European species. In 1841
11
THOMS, WILLIAM J.
THOMSON, JAMES.
12
Mr. Thompson accompanied the late Professor Edward Forbes on a
Toyago in the Mge&n in H.M.S. Beacon, commanded by the late
Captain Graves, ll.N., during which ho made a large number of obser-
vatious on the natural hibtory of the countries which he visited.
Some of these he subsequently made use of in his works on the
natural history of Ireland. From 1841 to 1843 he was a frequent
contributor to the ' Annid* of Natural History,' and also engaged in
collecting materials for bis further report to the British Association
on the Invertebrate Fauna of Ireland. This report was read at the
meeting of the association at Cork in 1843, and is remarkable for the
large amount of minute information it contains on the natural history
of Ireland. From this time his papers on Irish natural history
became more numerous ; a list of above seventy is given in the
Kay Society's ' Bibliography,' and these were preparations for a great
work which he had projected on the natural history of his native
country. The first volunio of this work appeared in 1849, the second
in 1650, the third in 1851. These three were devoted to the birds.
He did not live to complete his work. He had been mainly instru-
mental in inducing the British A!=80oiation to meet in 1852 in Belfast,
lu promoting this object he came to London in the January of that
year, when lie was seized with paralysis, and died in the course of a
few hours. The manuscript of another volume on the ' Natural History
of Ireland ' was found after his death in a sufficiently advanced state
to be given to the public, and this was published with a short memoir
of the author iu 1856. He took an active interest in all the local
institutions of his native town. He was president of the Natural His-
tory and rhilosophioal Society of Belfast, member of the Royal Irish
Academy, and honorary fellow and member of several foreign scientific
societies. William Thompson is a remarkable instance of a man who,
by the devotion of average talents to one great object, succeeded in
his work on the natural history of Ireland in achieving for himself a
lasting reputation, and giving to science one of its most valuable mono-
graphs on the distribution of animals iu Europe.
* THOMS, WILLIAM J., was born iu Westminster, on Nov. 10,
1803, his father being Nathaniel Thorns, the secretary of the first
Commission of Revenue Inquiry. After a careful education he
became a clerk in the secretary's office at Chelsea Hospital, and has
subsequently been made one of the clerks of the Printed Papers
Department in the House of Lords. His leisure was employed in
writing articles for the ' Foreign Quarterly Review,' and other periodi-
cal works. In 1823 he published in three volumes ' A Collection of
Ivarly Prose Romances;' in 1834, 'Lays and Legends of Various
Nations;' and in 1838 the 'Book of the Court.' In this year he was
elected a Fellow of the Society of Antiquaries, and he is also a member
of those of Edinburgh and Copenhagen. In 1839 he edited ' Anecdotes
and Tiaditions ;' in 1842, ' Stow's Survey of London,' adding many
valuable notes and verifications, and a notice of the life and writings
of Stow; and in 1844, Caxton's * Reynard the Fox :' he has likewise
published a translation of Worsaae's 'Primeval Antiquities of Den-
mark,' 8vo, 1849, of which he considerably increased the value by a
preface and notes, pointing out the extent and the manner in which
tiie researches of the author on the primeval remains of Denmark
throw light upon those of this country. For a considerable time he
has held the office of secretary to the Camden Society. His most
noticeable effort however has been the originating of the publication
of ' Notes and Queries,' of which he has been the editor since the com-
mencement in Nov. 1849; a work which has been most successfully
carried on under his management, and which has collected an amount
of curious and valuable inlorcQatiou scarcely paralleled by any publica-
tion with which we are acquainted; and to the contributions of Mr.
Thome, as well as to his editorial supervision, has the value and
success of ' Notes and Queries ' been essentially indebted.
THOMSON, ANTHONY TODD, was born in Edinburgh on the
7th of January 1778. His father, by birth a Scotchman, had settled
in America, where he held two lucrative appointments under the
Erifidh government, being Postmaster-General for the province of
Georgia, and Collector of Customs for the town of Savannah. Having
refused to take the oath of allegiance to the American government, on
the breaking out of the Revolution he was compelled to relinquish
his appointments, and returned to Edinburgh. Anthony Todd was
born previous to this whilst his mother was on a visit to Edinburgh.
He received his education at the High School, Edinburgh. When a
boy he formed an intimacy with Henry, afterwards Lord Cockburn,
which lasted till his death. His father destined him for business, but
having obtained a clerkship in the Post-office, he was enabled by the
leisure it afforded him to gratify a wish he had always entertained to
study medicine. He attended the lectures of Munro, Gregory, Black,
and Dugald Stewart. In 1798 he became a member of the Speculative
Society, and the companion of Jefi^rey, Horner, Brougham, and Lord
Tjansdowne. In 1799 ho became a member of the Royal Medical
Society. Having graduated in 1799, he left Edinburgh, and established
himself in London about the year 1800. He commenced the practice
of his profession in Sloane-street, Chelsea, as a general practitioner.
His progress was at first slow, but when once commenced it was never
interi upted. In the midst of a large general practice, he found time
to cultivate science and literature. He was mainly instrumental in
procuring the enactment of the Apothecai-ies Act in 1814, His first
literary work was published in 1810, and entitled ' Conspectus Pharma-
oopisQ.' He sold the copyright of this book for twenty pounds. In 1833
it was bought by the Messrs. Longman for two hundred pounds. It
has gone through fourteen editions. In 1811 he published the * London
Dispensatory,' which was a work of great labour. It contained a
critical account of all the medicines and their compounds which were
in use in Great Britain. It has been translated into several European
languages, and ten editions have been published in England. During
his researches into the materia medica he was impressed with the
importance of the study of botany, and he was one of the first
to give a course of lectures on this subject in London. In 1821 he
published a first volume of his ' Lectures on Botany.' This work con-
tained many very valuable observations on the structure and functions
of plants which have since become a part of the science of botany.
In his observations, he made extensive \ise of the microscope, and may
fairly claim to be one of those who appreciated the value of this
instrument, when its use was generally neglected. In 1826 he became
a member of the Royal College of Physicians of London, and com-
menced practice as a consulting physician. In 1828 he was elected
professor of Materia Medica to the then London University, now
University College. In this position he worked with great ardour at
the subject of Therapeutics, and was one of the first to introduce the
new substances discovered by the chemist into the practice of medi-
cine. He formed here a very fine collection of specimens of materia
medica, but the college had not the means of purchasing it after his
death, and it has been lost to the country. In 1832 he was appointed
professor of Medical Jurisprudence. The lectures delivered from
this chair were published in the 'Lancet' in 1836-7. In 1832 Dr.
Thomson published his ' Elements of Materia Medica,' a work of a
more scientific character than his ' London Dispensatory,' and entering
more fully into the subject of Therapeutics. Three editions of this
work had been published at the time of his death. In 1839 he
edited ' Bateman on Cutaneous Diseases,' and at the time of his death,
he was engaged in preparing 'A practical Treatise on Diseases afiecting
the Skin,' which has since been completed and edited by Dr. Parkes.
In 1848 his health first began to fail. He continued to give his lec-
tures, with considerable interruptions, till tlie following summer, when
he was obliged to retire into the country, and died of bronchitis at
Ealing on the 3rd of July 1849.
Dr. Thomson was a man of unwearied industry, and throughout
his long career, pursued his labours with lew or no interruption'^.
He was a man of varied attainments, cultivating literature as
well as science, and was not an unfrequent contributor of literary
article! to the Magazines and Reviews. He translated from tho
French, and e Jited, a work by Mon.". Salvarte, entitled ' The Philosophy
of Magic, Omens, and apparent Miracles.' His notes to this work are
full of curious and interesting matter. He edited also an edition of
Thomson's ' Seasons ;' to which he appended a large number of notes,
and a life of the author, lie contributed many articles to the* Cyclo-
pffidia'of Practical Medicine.' He was for many years editor of tho
'Medical Repository;' to which journal he also extensively con-
tributed. One of his last works was entitled ' Domestic Management of
the Sick-room,' of which several editions have been printed. A sketch
of his life, from which the materials of this notice have been prin-
cipally obtained, is published with his posthumous work on ' Diseases
of the Skin.'
* Mu3. A. T. Thomson, the wife of Dr. Thomson, has contributed
rather largely to literature, chiefly in tho department of historical
biography. She has published ' Memoirs of the Court of Henry Vlll.,'
2 vols. 8vo, 1826; 'Memoirs of Sarah, Duchess of Marlborough, and
of the Court of Queen Anne,' 2 vols. 8vo, 1839; 'Memoirs of the
Jacobites of 1715 and 1745,' 3 vols. 8vo, 1845; and 'Memoirs of
Viscountess Sundon, Mistress of the Robes to Queen Caroline, Consort
of George II., including Letters from the most celebrated Persons of
her Time, now first published from their Originals,' 2 vols. 8vo, 1847.
She has also written several romances and novels. Her latest publica-
tion is * Recollections of Literary Characters and Celebrated Places,'
2 vols. 8vo. This work consists chiefly of a series of articles which
appeared originally in ' Bentley's Miscellany ' and * Eraser's Magazine,'
with the signature of ' A Middle- Aged Man,' an appellation which she
assumed, as she states, " in order that by better disguising myself, I
might at that time express myself the more unreservedly."
THOMSON, JAMES, was born at Ednam in Roxburghshire on the
11th September 1700. His father was clergyman of the place, and
distinguished for his piety and pastoral character. James was first
sent to the grammar-school at Jedburgh, and completed his education
at the University of Edinburgh, where in 1719 he was admitted as
a student of divinity.
Thomson turned from divinity to poetry owing to the following
incident : — The Rev. Mr. Hamilton, who then tilled the chair of
divinity, gave as a subject for an exercise a psalm in which the majesty
and power of God are described. Of this psalm Thomson gave a para-
phrase and illustration as the exercise required, but in so poetical and
figurative a style as to astonish the audience. Mr. Hamilton compli-
mented the performance, and pointed out to the audience its most
striking points; but, turning to Thomson, he suggested that if he
intended to become a minister he must keep a stricter rein over his
imagination, and learn to be intelligible to an ordinary congregation.
Some encouragement held out to him by Lady Grisel-Baillie following
13
THOMSON, JAMES.
THORBURN, ROBERT, A-R.A.
14
thi8 intimation of the Professor, he determined to give up divinity and
try bis fortune in London. Slender as this pretext of * encouragement '
was, there have been many poets who have thus sought their fortune
from no stronger reason. The truth is, Thomson wanted to try his
capacity in London, and seized on this as a pretext.
Arrived in London, eays Dr. Johnson, he was one day loitering
about " with the gaping curiosity of a new-comer, his attention upon
everything rather than upon his pocket," when his handkerchief, con-
taining his letters of recommendation to several persona of consequence,
was stolen from him. And now the lonely poet in the vast city first
felt his inexperience and his poverty. A pair of shoes was his first
want; his manuscript of 'Winter' his only propertj'. A purchaser for
this poem was found with great difficulty ; but Mr. Millar consented to
give a trifle for it, and it was published in 1726. It was little read till
Mr. Whately and Mr. Spence spoke so favourably of it that attention
was attracted, and it rose rapidly into popularity, and one edition very
speedily followed another. This success procured him many friends,
among whom was Dr. Kundle, who introduced him to the lord chan-
cellor Talbot, and some years after, when the eldest son of that
nobleman made a tour on the continent, Thomson was appointed his
travelling companion. Meanwhile his poetical powers were fully
employed, and in 1727 appeared his ' Summer,' in 1728 his ' Spring,'
and in 1730 his 'Autumn.' Besides these, he published, in 1727,
' A Poem sacred to the memory of Sir Isaac Newton,' and ' Britannia,'
a poetical invective against the ministry for the indifference they
showed to the depredations of the Spaniards in America. By this
piece he declared himself a favourer of the opposition, and therefore
could expect nothing from the court.
The tragedy of 'Sophonisba' was acted in 1727, Wilks taking the
part of Masinissa, and Mrs. Oldfield that of Sophonisba. So high
were the expectations raised, that every rehearsal was dignified with a
splendid audience collected to anticipate the pleasure that was pre-
paring for the public. Its success however was very equivocal.
" There is," says Johnson, " a feeble line in the play : —
' O, Sophonisba, Sophonisba, O ! '
This gave occasion to a waggish parody,
' O, Jemmy Thomson, Jemmy Thomson, O ! '
which for awhile was echoed through the town."
At this time long opposition to Sir Robert Walpole had filled the
nation with clamours for liberty, and Thomson, instinctively seizing
the poet's office to utter in verse the wants of the nation, determined
on writing a poem on 'Liberty.' He spent two years on.this under-
taVicg, and viewed it as his noblest work, probably because it had
cost him the most trouble. It was divided into five parts, which were
published separately, thus : ' Ancient and Modern Italy compared,
being the first part of " Liberty," a poem,' 1735; ' Greece, being the
second part, &c.,' 1735 ; * Eome, being the third part, &c.,' 1735 ;
'Britain, being the fourth part, &c.,' 1736 ; ' The Prospect, being the
fifth part, &c.,' 1736. The poem of 'Liberty' does not now appear
in its original state, having been shortened by Sir George (afterwards
Lord) Lyttelton. Of all Thomson's poems this is the least read, and
deservedly so, for, independent of the feebleness of its execution, it is
obvious, as Johnson remarked, that " the recurrence of the same images
must tire in time ; an enumeration of examples to prove a position
which nobody denied must quickly grow disgusting."
His friend Talbot appointed him secretary of briefs, a place requiring
little attendance, suiting his retired indolent way of life, and equal to
all his wants. When his patron died Lord Hardwicke succeeded him,
and kept the office vacant for some time, probably till Thomson should
apply for it ; but either his modesty, pride, or depression of spirits
prevented his asking, and the new chancellor would not give him
what he would not request. This reverse of fortune increased his
literary activity. In 1738, besides editing his own works in two
volumes and writing a preface to Milton's ' Areopagitica,' he produced
the tragedy of ' Agamemnon,' with Quin for his hero. For this he
got " no inconsiderable sum," though it had but poor success. John-
son says that on the first night Thomson seated himself in the upper
gallery, and was so interested in its performance, that "he accompanied
the players by audible recitation, till a friendly hint frighted him to
silence." Thomson's next tragedy was ' Edward and Eleonora,' which
was not allowed to be represented on account of certain pretended
allusions. He then wrote, conjointly with Mallet, the masque of
'Alfred,' which was represented before the Prince and Princess of
Wales at Clifden in 1740. This masque contains the national song of
'Rule Britannia,' which Mr. Bolton Corney ascribes, "on no slight
evidence," to Mallet. Thomson's next work was another tragedy,
* Tancred and Sigismunda,' which, being taken from the interesting
story in ' Gil Bias,' instead of the Grecian mythology, as were his
other pieces, had more success. Garrick and Mrs. Gibber played the
principal parts. His friend Sir George Lyttelton now appointed him
surveyor-general of the Leeward Islands, from which, after paying a
The ' Castle of Indolence,' which was many years under his hands,
was now finished and published (1748). It was at first little more
than a few detached stanzas, in the way of raillery on himself, and on
some of his friends who reproached him with indolence, while he
thought them at least as indolent as himself. But the (mbjoct grew
under his hands till it became his masterpiece.
A violent cold, which from inattention became worse, at last carried
him oflP, on the 27th of August 1748. He left behind him a tragedy
of ' CoriolanuB,' which was brought on the stage by Sir George Lyttel-
ton for the benefit of his family. A contiiderable sum was gained
which paid his debts and relieved his sisters. The remains of the poet
are deposited in Richmond Churchyard.
Thomson was " more fat than bard beseems; " of a simple, unaffected,
indolent, sensual character ; silent in company, but cheerful among
friends, of whom he had many and true. This character is discern-
ible in his writings. His simplicity is seen in the purity and warmth
of his sentiments, sometimes oven childish; his indolence in the
slovenliness of his versification, and the inappropriateness of so many
of his epithets : ho never seems to have thought anything worth the
toil of polishing, and hence the perpetual use of pompous glittering
diction substituted for thought or description ; his sensuality appears
in the gusto with which he describes all luxuries of the senses, and
the horrors of deprivation. Amidst much that is truly exquisite both
in feeling and expression, he mingles the absurdities of a schoolboy's
trite commonplaces and mechanical contrivances to piece out his verse.
A sweet line of almost perfect beauty is followed by a bombastic
allusion, or some feeble personification as tiresome as the first was
bewitching. A touch of nature is overloaded by superfluous epithets
— a picturesque description is often marred by pedantry or by careless-
ness. In spite of these drawbacks, Thomson is a charming poet, and
one whose works hive always been the delight of all classes. The
popularity of his * Seasons ' equals that of any poem in the language,
and it is said that some one, finding a shabby copy of it lying on the
window-seat of a countiy ale-house, exclaimed " That's true fame ! "
Thoinson's beauties are genuine : his descriptions of nature often
come with the force of reality upon the mind ; and no one ever
painted more successfully the ' changing scene ' and the ' rustic joys '
of England.
His ' Castle of Indolence ' may be regarded as his best-sustained
effort ; for, although separate passages of the ' Seasons ' may be supe-
rior, yet on the whole it has fewer defects, while some of the stanzas,
especially in the first canto, fill the mind with lazy luxury. Of his
tragedies we need say little : their neglect has been so signal, that we
may accept so unanimous a verdict without further examination ;
indeed the genius of Thomson was eminently undramatic.
THOMSON, THOMAS, M.D., a celebrated chemist, was bom April
12, 1773, at Crieff, Perthshire, and received his early education at the
parish school of that place. He afterwards studied at St. Andrews
and Edinburgh, and was a pupil of the celebrated Dr. Black. lu
1802 he delivered a course of lectures on chemistry, and continued to
lecture on this science for nearly fifty years. He was one of the
editors of the 'Encyclopedia Britannica' from 1796 to 1800, and
wrote the articles * Chemistry,' ' Mineralogy,' &c. in that work. In
1802 he published his 'System of Chemistry.' He first suggested
the use of symbols in chemistry, which have since become so generally
employed. He was one of the first chemists who recognised the
value of Dalton's atomic theory, and devoted himself to its elucida-
tion. He also at this time conducted for the Board of Excise a series
of investigations on brewing, which formed the basis of Scottish legis-
lation on that subject. In 1813 Dr. Thomson came to London, and
started the ' Annals of Philosophy,' a scientific joui"nal, which he edited
till the year 1822, when he resigned it to his friend Mr. Richard Phillips.
In 1827 this journal became merged in the 'Philosophical Magazine.'
In 1817 he was elected lecturer on chemistry in the University of
Glasgow, and the following year received the title of professor. This
chair he held till his death, assisted in his later years by his nephew
and son-in-law Dr. R. D. Thomson. In 1835 he published a work,
entitled ' Outlines of Mineralogy, Geology, and Mineral Analysis,'
and in 1849 a work on ' Brewing and Distillation.' He died on the
2nd of July 1852. His son. Dr. Thomas Thomson, is celebrated for
his botanical knowledge ; he has published an account of his ti'avels
in Thibet, and is now the superintendent of the East India Company's
botanic gardens at Calcutta.
•THORBURN, ROBERT, A.R.A., was born at Dumfries, Scotland,
in 1818, and entered in 1833 as a student in the Scottish Academy,
Edinburgh, where he gained the highest honours. Having chosen
miniature-painting as his special province, he in 1836 came to London,
and quickly succeeded in securing a considerable measure of patronage
among the leading members of the court and ai'istocracy. He has
adopted a largeness of size as well as of style unusual with miniature-
painters, and he has endeavoured to superadd something of the depth
of tone and breadth of chiaroscuro usually found only in oil-paintings
to the brilliancy and transparency belonging to painting on ivory.
He has succeeded to a great extent in raising the style of painting on
ivory; but under his hands, and still more in the hands of his imitators,
the miniature has lost something of the gaiety whic'n seems essential
to that class of paintings, Mr. Thorbum's likenesses are usually good
and characteristic, but there may often be seen a too evident attempt
to impart historical elevation to the countenances and figures of his
sitters, and this is sometimes sought to be increased by the adaptation
of the forms and arrangement of well-known compositions of the great
Italian masters. For many years, from the rank or eminence of his
15
THORDO.
THORILD, THOMAS.
16
sitters, and the size and beauty of his paintings, his miniatures have
been among the most attractive of those annually exhibited in the
rooms of the Royal Academy. The Queen, the Prince Consort, and
several of the royal children, many members of the royal families of
France, Belgium, and Qermany, with an almost endless atray of the
female aristocracy of England, have been painted by him, and seldom
indeed have female loveliness and dignity been more happily por-
trayed. Mr. Thorburn was elected an associate of the Royal Academy
in 1848, immediately after he exhibited his large miniature of ' the
Queen and the Princess Helena and I'rince Alfred.'
THORDO is the Latinised name of a celebrated Danish lawyer,
whose real name was Thobd, or, more completely, Thokd Deohn.
He lived in tho reign of Waldemar III., king of Denmark, and was
descended from an ancient family of that country. Concerning his
life, little is known beyond the fact that he was chief judge of tho
province of Jutland. His name has come down to us through a
collection of Danish laws which he formed into a kind of code. It
contains the earliest Danish laws, to which no historical origin can be
assigned, as well as the subsequent laws which were passed between
the years 1200 and 1377 by the Danish parliament, and sanctioned by
the kings. They are not arranged in chronological order, but sys-
tematically, and comprise civil as well as constitutional laws. They
are of very great value to the student of the social and political
history of Denmark. Danish editions of this small code appeared at
Ripen, ito, 1504, and at Copenhagen, 4to, 1508. Ludewig, in his
' Reliquiae Manuscriptorum omnis sevi diplomatum ac momentorum
ineditorum,' vol. xiL, pp. 166-216, has published a Latin transla-
tion of this code of laws. In the title to them Thordo calls himself
"Thordo legifer Daciae," where Dacia} must mean Danise, that is,
Denmark.
THORDSON", STURLA, belonged to the celebrated Icelandic family
of the Sturla ; his name Thordson indicates that he was a son of
Thordo. He was a nephew of Snorri Sturluson, and born about a.d.
1218. Being a man of high rank and great knowledge, he was appointed
to the most important offices by the Danish kings Hacon aud Magnus,
and it was at their command that he wrote the history of Iceland,
Denmark, and Norway, from the time when the work of Snorri Stur-
luson broke off. This history bears the title of ' Historia Sturlungo-
rum,' but the work which is now extant under that name is only an
abridgment of the original history, and the latter part is altogether
lost. The substance of the work is given in Torfaeus, * Historia
Rerum Norvegicarum,' who, in his Prolegomena, also pives an account
of the ' Historia Sturlungorum.' Thordson died in 1288, at the age of
seventy.
THORER, ALBAN. [Torinus, Albancs.]
THORESBY, RALPH, a virtuoso and antiquary, and an early
Fellow of the Royal Society, was the son of a merchant of Leeds, and
born in that town in 1658. He had his early education in the Leeds
grammar-school, but, being intended by his father for commercial life,
he did not pass to any of the higher seats of learning. He had how-
ever what may be called a liberal commercial education, being sent by
his father to Holland for the purpose of becomiug acquainted with the
mode of conducting business in that country, and of acquiring the
modern languages ; and afterwards to London for a similar purpose.
He settled in his native town, where his family was connected with
some of the principal persons who then formed the society of Leeds,
successfully conducted by his father, who died when the son was just
twenty-one.
Thoresby possessed from a very early period of life an eager curiosity
respecting the things and persons around him which presented any
features of historical interest, and a desire of collecting objects of
curiosity, natural or artificial. His father had something of the
same taste, having purchased the collection of coins and medals
which had been formed by the family of Lord Fairfax, the parlia-
mentary general, and this collection was the basis of the museum
formed in a few years by the son. This museum was a means of
bringing him acquainted with all the celebrated antiquaries and
naturalists of the time, and was a perpetual attraction to persons of
curiosity, who often visited Leeds for no other purpose than to see it.
It is not too much to say of it that it was the best museum that had
been formed in England by a gentleman of private and rather small
fortune; containing, it is true, eome things which would now be
esteemed of not the smallest value, but also many objects of very
high value, especially in the two grand departments of manuscripts
and coins. As he advanced in life, the curiosity which had at first
been directed upon the objects more immediately around him became
expanded so as to comprehend objects of more general interest, and
in fact the whole range of what is generally understood to be com-
prehended in the term antiquarian literature. In the department of
natural history he was also not merely a collector, but an observer, and
he made many communications, esteemed of value, to his private
friends or to the Royal Society.
With this turn of mind, it will hardly be supposed that he was
very successful in his mercantile affairs. He liad however the good
sense to withdraw from business before his fortune was entirely lost
to him, and about the forty-sixth year of his age he seems to have
wholly retired from it, and to have formed the determination of living
on the little income which the portion of his property that remained
would afford him.
Besides amassing such manuscript matter as he could by any means
become possessed of, he was himself a laborious transcriber, and was
also accustomed to commit to writing notes of things which he
observed, or information collected from his friends or the old people
of his time. When released from the cares of business, he had leisure
to make use of these notes, and he entered upon the preparation for
the press of two works, which it was intended by him should contain
all that he had gathered in what had been from the first his favourite
subject, the illustration of the history, and whatever belonged to it,
of his native town. One of them was to be in the form of a topo-
graphical survey of the whole of the large parish of Leeds, and of a
few of the smaller parishes which are supposed to have been com-
prehended under the very ancient local term ' Elmete : ' the other, a
history of the various transactions of which that district had been tho
scene, of its more eminent inhabitants, of the public benefactors, and
of the changes which had taken place in the state or fortunes of its
inhabitants. The first of these designs only was accomplished. Tho
work appeared in a folio volume in 1715, under the title of * Ducatus
Leodiensi^, or the Topography of the Town and Parish of Leeds.*
This work leaves little for the inhabitants of the town to desire in
this kind, except that he had prepared the ' historical part ' also, to
which the author is perpetually referring the reader. The work is more
than its title promises, since it contains a large body of genealogical
information, comprehending the descents of nearly all the families of
consequence who inhabited the central parts of the West Riding. There
is also a very large descriptive catalogue of the treasures deposited in
his museum.
The ' Ducatus ' is the principal literary work for which we are
indebted to him. As a kind of supplement to it, he published, in
1724, a history of the Church of Leeds, under the title ' Vicaria Leo-
diensis,' which, like his foi'mer work, has many things not strictly
belonging to his subject, but in themselves valuable. A new edition
of the * Ducatus,' containing also all the matter of the ' Vicaria ' which
Whitaker, LL.D., in 1816. The writings of Bishop Kicolson, Bishop
Gibson, Obadiah Walker, Calamy, Strype, Hearne, and many other
persons, show how willing Thoresby was to give assistance to any of
his literary friends in their various publications. He died in 1725.
Thoresby kept during the greater part of his life an exact diary of
each day's occurrences. Large extracts from the portions which
remain of it were published in two octavo volumes in 1830, and two
more volumes were published at the same time of selections from the
letters of his various friends ; these were published under the care of
Mr. Hunter. They exhibit the peculiar features of a somewhat remark-
able character, and the particular incidents of his life. An ample
account of Thoresby may be found in the 'Biographia Britannica,' aud
another prefixed to Dr. Whitaker's edition of his topographical work.
THORILD, THOMAS, an eccentric Swedish poet and political
speculator, the author of several works not only in Swedish but in
English and German, to some of which his countrymen ascribe a high
value, was born on the 18th of April 1759, in the parish of Svarteborg
in Bohusliin. His father's name was Thorou, which the son, after
bearing for some time, changed to that of Thorild, for what reason is
not apparent. After studying at Lund he took up his residence in
Stockholm, and his first work ' Passionerna,' an Ode on the Passions,
was criticised with some severity by Kellgren (Kellgeen), and in con-
sequence a lengthy paper war took place between th"e two which
brought Thorild's name into notice. In 1786 he addressed a pair
of memorials, one to the king, the other to the people, in favour of
liberty of the press, and was so disgusted at the little effect they
produced, that for that and other reasons he determined to transfer
himself to England. " England," he declared, " was the fatherland of
his soul, he was born for it, if not in it." Before going however, he
wished to obtain the degree of doctor at the University of Upsal, with
the view of inspiring more respect. His public disputation for a
degree on the 22nd of IVIarch 1783 was the most remarkable ever
known at that university. The king, Gustavus III., and all his court
were present, and among the opponents of Thorild on his theme,
which was * A Criticism on Montesquieu,' were fifteen of the courtiers,
one of whom was the minister Schroderheim, another the poet
Leopold, at that time the leading poet of Sweden. The king was, it is
said, struck with admiration at the talents of Thorild, and testified a
desire to take him under his patronage ; but much of this rests on
Thorild's own testimony, and he was throughout life remarkable for
inordinate self-conceit. If an offer was really made it did not prevent
him from coming to England. His object in doing so, as appears
from some private letters to his patron Tham, a dry antiquary,
who supplied him with money, was to effect a * World Revo-
lution.' "To understand and to act were," Thorild said, "the two
great attributes of humanity. He who excels in one is called a
Genius, in the other a Hero. The legislative power ought to be in the
possession of Genius, and as mankind requires an armed executive
also, that power ought to be in the possession of Heroes. Scoundrels
—that is, kings, ministers, and priests — should receive a warning, and
if any did not attend to it, the sentence should then be passed on
them — 'Feriendus' (To be Struck)." "This is a hero-worship," says
17
TFIORKELIN, GRIM JONSSON.
THORLAKSSON, JON.
is
Pamblad, in bis Swedish biography of Thorild, "resembliDg that of
Thomas Carlyle, who iu mind is near akin to Thorild." Tho ideas
however of Tliorild, which include, among other things, the destruc-
tion by fire of all great cities, as " nests of folly and tyranny," have a
far more striking resemblance to those of the wildest of the French
revolutionists, which they have the merit, such as it is, of anticipating.
It was in September 1788 that Thorild came to England, where he
remained a year and a half, so that he must have been in London at
the time of the outbreak of -the French revolution, yet he seems to
have made no movement to transfer himself to Paris. At first he was
delighted with England, and wrote from Scarborough, " Almost every-
thing here is of its kind the best I have seen, the beer, the theatre, the
letters, the sermons." As might be expected his opinions soon changed,
and for the rest of hia life he wrote of the country with great con-
tempt. " The whole government of England," he told Tham in 1790,
" is a balance of violence and justice, of sense and nonsense, of truth
and falsehood, which is indeed necessary in the idea of a balance."
While here he published two pamphlets in English, ' The Sermon of
Sermons on the Impiety of Priests and the Fall of Religion,' London,
1789 ; and ' Pure Heavenly Religion restored,' London, 1790 ; the
one an attack on religion in general, the other, not very consistently,
a defence of the docti-ines of Swedenbdrg. Both of them fell still-bom
from the press. Some others, ' On the Dignity of a free Death, with a
view to state that grand right of man, by a Druid,' and ' The Royal
Moon, or on Insanity in Politics,' appear not to have been printed,
and ' Cromwell, a sketch of an epic poem,' was left unfinished, but was
afterwards printed in Sweden by Geijer. It begins —
" Great is the man I sins', and bold my theme,
A dread to feeble souls as lightning's gleam
In midnight, or loud thunderings* solemn roar,"
and shows, amid occasional incorrectness, a power over English poetical
language very rarely attained by a foreigner. Cromwell was Thorild's
favourite hero — another point of resemblance to Carlyle. The Swede,
as might be anticipated, hailed with delight the outbreak of the
French revolution, though, as we have seen, he kept at a safe distance
from it. He continued to express his warm admiration of its progress,
and his detestation of those who thought otherwise, for some years, till
he was suddenly converted to an anti-revolutionist by the Reign of
Terror. On his return to Sweden iu 1790 ho resumed his literary
labours, and not long after the death of Gustavus III., who was always
his admirer, issued a new edition of a former publication, an ' Essay
on the Freedom of the Public Mind,' with a dedication to the Duke
of Sudermania, then regent, afterwards Charles XIII., in which these
words occurred, " Give us then the freedorn of the public mind,
honestly and fairly, before it is taken with blood and violence." For
this passage and some otiiers of similar tendency Thorild was brought
to trial on a capital charge, but was finally only sentenced to four
years' banishment. Tliis trial, which terminated in February 1739,
was at once the most conspicuous and the most honourable incident in
Thorild's life, he showed great coolness during its progress, and wrote
a series of poems in prison. He removed to Greifswald, then part of
Swedish Pomerania, and before his years of banishment were over,
was appointed by tho Swedish government librarian of the university
there, and afterwards a professor. The rest of his life was spent
quietly at Greifswald, where he died on the 1st of October 1808.
A collection of the works of Thorild, ' Thomas Thorild's Simlade
Skrifter ' was published in 3 vols, at Upsal and Stockholm, between
1819 and 1824, under the editorship of Geijer, who took the objection-
able liberty of leaving out such passages as he thought ought not to have
been written. One volume consists of poems, the two others of
literary criticism and essays on general subjects. As a literary critic
the most striking peculiarity of Thorild was his boundless admiration
of Ossian. Those who feel a curiosity as to his philosophical opinions
in general, may find ample information in the 'Svenskt Pantheon,'
and in Atterbom's 'Svenska Siare och Skalder' (Swedish Seers and
Bards). While at Greifswald he became the friend of Herder, the
German philosopher, whose works were left to him to edit.
THORKELIN, GRIM JONSSON, a learned Icelander, was born in
1749, according to a life in the 'Monthly Magazine' for 1803, in
1750, according to Jens Worm, and on the 8th of October 1752,
according to Erslew, who refers to the accounts in the ' Monthly
Magazine,' and Worm, as "autobiographies of Thorkelin." Many
similar discrepancies occur in the accounts of other circumstances of
his early life, but they are hardly worth the trouble of pointing out.
According to a resci-ipt of the King of Denmark, issued in 1759, one
of the best scholars in Iceland was to be selected every year to be sent
to Denmark, and editcated at the public expense, and the choice of
Bishop Finn Jonsson [Jonsson] fell in 1770 upon Thorkelin. As his
chest was too weak to allow him to become a preacher, he took to the
study of law, and combined with it that of antiquities. He soon dis-
tinguished himself by the publication of several Icelandic works
which he edited, among others of the ' Eyrbiggia-Saga,' of which an
various posts in connection with the Ama-Magna3an Commission, the
Secret Archives, and other learned establishments of Copenhagen ;
received in 1783 the title of Professor Extraordinary, and in 1786 he
was sent to England, mainly at the King of Denmark's expense, on a
PIOG. DIV. VOL. VI.
tour of antiquarian research, which was to laat for four yearn, and
ultimately extended to five. In England he made himself acquainted
with many of tho distinguished literary men of the time, Pinkerton,
Horace Walpole, and Macpherson, the transLitor of ' Osaiaa ' included.
He was presented to King George III., and at his deaire, made a
selection of Danish literature for the library then at Buckingham
House, now in the British Museum. The 389th volume in the manu-
scripts of that library is a ' Catalogue consisting of 2085 books relative
to tbe Danish, Swedish, Norwegian, and Icelandic Literature and
Philosophy, written by the natives, and published within the borders
of Scandinavia. A collection made for purpose [on purpose (?) or for a
purpose (?)] during a time of more than twenty years.' Both the col-
lection and catalogue were made by Thorkelin, and most of the books
were acquired for the royal library. He made a tour in Ireland, and
also a tour on the Scottish coast, of which he published an account in
English in 1790, in some letters to the ' Public Advertiser.' This was
not his only contribution to English literature. In 1788 he published
an * Essay on the Slave Trade,' and also ' Fragments of English and Irish
history in the ninth and tenth century, translated from the original
Icelandic, and illustrated with some notea,' the latter work forming the
48th number of Nichols's ' Bibliotheca Topographica Britanuica.' The
selections from the Icelandic sagas are interesting, but the translation
is far from clear, and is vague and inflated in style. Another English
work by Thorkelin which ran to a second edition, a ' Sketch of the
character of his royal highness the Princo of Denmark, to which is
added a short view of tho present state of literature and the polite
arts in that country ,' London, 1791, was translated into Danish, and
led to a paper war with other Danish writers, who complained of
some of its statements. The most important result of Thorkelin's visit
to England however was the copy that he took of an ancient Anglo-
Saxon poem in the Cottonian library, to which attention had been
called nearly a hundred years before, in Wanley's 'Catalogue,'
published in Hickes's ' Thesaurus,' but which had remained all the
time unedited by the learned of Britain. When in 1791 ho re-
turned to Denmark on his nomination as Geheime-Archivarius, or
Keeper of the Secret Archives, it seems to have been his intention to
publish this work without delay, but his biographer in the ' Monthly
Magazine' for 1803, concludes his narrative by the statement that
" in the course of a year after his return, he married a rich widow in
the brewing line, wbicli he conducts at this day," and business seems
to have interfered with literature. Thorkelin had however prepared
it for publication at the time of the unexpected attack on Copenhagen,
in 1807, when his translation of tbe poem perished with his house and
library under the English bombardment. He was encouraged to take
up the work again by Counsellor von Biilow, and finally the poem and
translation were published together in one quarto volume at Copen-
hagen in 1815, at von Billow's expense, under the singular title of
' De Danorum Rebus Gestis Seoul. III., IV,, Poema Danicum Dialecto
AngloSaxonica.' This is the poem which has since become so cele-
brated under the name of * Beowulf.' It will be seen that in the title
Thorkelin calls it a Danish poem in the Anglo-Saxon dialect, and in
his preface his language would lead a reader to conclude that the
poem was in Icelandic. W^hat he can have meant by this it is not
easy to say, but the only merit of his edition is that of having called
attention to this very interesting relic of ancient literature. " I am
most reluctantly compelled to state," says Kemble in his edition of
Beowulf (London, 1833), "that not five lines of Thorkelin's edition can
be found in succession in which some gross fault either in the tran-
script or the translation does not betray the editor's utter ignorance
of the Anglo-Saxon language." Thorkelin died on the 4th of March
1829, at Copenhagen, alter long suffering from ill health. A full and
accurate list of his works is given in Erslew's ' Forfalter Lexikon.'
Among them we find a "Proof that the Irish at the time of the
Eastmen's arrival in Ireland in the 8th century, deserve a distin-
guished place among the most enlightened nations of Europe at that
period," written in Danish, and published in the Transactions of the
Royal Society for the Sciences in 1794.
THORLAKSSON, JON, the Icelandic translator of 'Paradise Lost,'
was born on the 13th of December 1744, at Selardal, near Arnarfjord,
the son of a priest who was afterwards dismissed from the priesthood.
Thorlaksson himself incurred a similar punishment in 1772; a second
bastard child having been sworn to him he was dismissed from being
priest of Grunnarik, and deprived of holy orders. Fortunately for
him, Olaf Olafsson obtained in the following year from the king of
Denmark the privilege of establishing a printing office at Hrappsey in
Iceland, and Thorlaksson, who would otherwise probably have been
reduced to starvation, procured employment as corrector of the press.
classical education during three years spent at the school of Skalholt,
then the Icelandic capital ; and he assisted in translating into Latin
the Annals of Biorn of Skardso, perhaps the moat distinguished pro-
duction of the Hrappsey press. His learning won him favour : he
married the daughter of a peasant, who was partner with Olafsson in
the printing-oflSce, and in 1780 he was restored to the priesthood, but
with the reservation that ho was never to officiate in the diocese of
Skalholt. It was eight years later before he was presented to the
living of Bcegisa in the north of Iceland, the value of which was some-
what under seven pounds sterling a year, and reduced by his having
c
19
THORNHILL, SIB JAMES.
THORNHILL, SIR JAMES.
20
to pay a curate. The north of Iceland is tiill more uncultivated than
the other parts of the island. Hia wife refused to aocompany him to
his living, and died, separated from him, in 1808. In 1791 Halldor
Hjiilluiardsou, one of his parishioners, wrote to the Icelandic Literary
Society to say, that having acquired the year before a Danish trans-
lation of ' Paradise Lost,' he hod put it into the hands of a "gifted
friend," who had turned into Icelandic some specimeus which he sub-
mitted to their notice. The translation was so remiu-kably excellent,
that the society, on learning from whom it came, elected Thorlaksson an
honorary member, and undertook to supply him with a set of their
works, on condition of his supplying them with a translation of one
book of tlie poem every year. Before they had published three books
however the society itself came to a stop tor want of funds, and Thor-
laksson completed his translation in manuscript. The fame of it was
spread widely by the English travellers who came to Iceland, espe-
cially Sir Qeorge Mackenzie and the Rev. Ebenezer Henderson ; but
Thorlakssou's desire to see it iu print was never gratified in his life-
time. One of his poems, some verses addressed to the British and
Foreign Bible Society on the occasion of their publishing an Icelandic
Bible, having been inserted iu their Ileports, had a very wide circu-
lation, and was even reprinted at Calcutta. Henderson, who visited
him at Boegisa in 1 814, and who was the first Englishman be had ever
seen, found the old man of fieveuty out iu the fields, assisting in hay-
making, and accompanied him home to ^ house of which ho gives an
interesting description : — " The door is not quite four feet in height,
and the room may be about eight feet in length by six in breadth. At
the inner end is the poet's bed, and close to the door over against a
small window not exceeding two feet square is a table where he com-
mits to paper the efifusions of his muse." In this cottage Thorlaksson
died on the 21st of October 1819, at the age of seventy-four. He had
received not long before a subscription of 'SOL, collected by Henderson
from friends and admirers in England, and the King of Denmark had
conferred upon him a pension of about 61. a year.
The collected poems of Thorlaksson fill about 1100 pages in the
'Islenzk Lj6dabok Jons Thorlakssonar prests ad Boegisa,' 2 vols.,
Copenhagen, 1842-43. These volumes comprise all his shorter poems,
composed from the age of twelve to over seventy, gathered from
seven Icelandic periodicals in which they had appeared, and several
translations, among others one of Pope's ' Essay on Man,' rendered
through the Danish, which had been printed at Leyra in Iceland in
1798. The fame of Thorlaksson rests however on his version of
* Paradise Lost.' That this, iu the shape in which he gives it, is a fine
Icelandic poem, is established by the testimony of all Icelanders. Its
value as a correct representation of the original is less clear. The
versification adopted, the * fornyrda-lag,' or * antique verse ' of Iceland,
with short lines and alliterative correspondences, is as different as
possible from the blank verse of Milton, being in fact very nearly
the metre of Piers Plowman. The translation is made from two
versions, one in Danish, the other in German, and Thorlaksson, it
is said, had never even seen the original. When, at the outset of
his task, the Icelandic Literary Society offered to send him a copy,
together with a German translation, he accepted the offer of the
German with thanks, but remarked, " with the English original I can
have little to do, though once, in my early years, I bad some acquaint-
ance with easy English prose." The translation is about twice the
length of the original, from the necessity of explaining to the com-
mon Icelandic reader not only the classical allusions with which
Milton abounds, but even various allusions which to an Englishman
need no explanation. Finn Magnusson, himself an Icelander, in a
review of the poem, observes that the passage in the description of
Paradise, " fniit with golden rind," has been rendered by Thorlaksson,
" med gyllnum ny ttum " (with golden nuts), probably from his having
no notion of rind, having never seen an apple or any fruit that had
any. The ' Paradise Lost' was finally prmted at Copenhagen in 1828,
at the expense of an English gentleman named Heath, who presented
most of the copies to the Icelandic Literary Society. The society sold
them in Iceland at a very low price, and it is now a household book in
many of the poorest cottages. A translation of Klopstock's ' Messiah '
from his pen was printed by the society itself in 1834-38 ; but it was
the work of his old age, and seems to be generally recognised as
inferior to the Milton.
THORNHILL, SIR JAMES, an eminent painter during the reigns
of Queen Anne and George I., and, says Walpole, "a man of much
note in his time, who succeeded Verrio, and was the rival of Laguerre
in the decorations of our palaces and public buildings," was descended
of a very ancient family in Dorsetshire, and was born at Weymouth
in 1676. Through the extravagance of his father, who disposed of
the family estate, Thornhill was compelled to support himself by bis
own exertions. He adopted the profession of a painter, and, by the
liberality of an uncle. Dr. Sydenham, the eminent physician, he was
enabled to pursue his studies in London, where he placed himself
with a painter, whose name is not known, with whom however he did
not remain long. Thornhill appears to have made rapid progress in
the public favour, for in hia fortieth year, when he made a tour
through Flanders, Holland, and France, he was sufficiently wealthy to
purchase many valuable pictures of the old masters and others.
Upon his return he received the commission froni Queen Anne to
paint the interior of the cupola of St. Paul's cathedral, in which he
executed eight pictures illustrating the history of St. Paul, painted in
chiaroscuro, with the lights hatched in gold : for this work he was
appointed historical painter to tho queen, yet was paid only forty
shillings the square yard for his production. Thornhill's reputation
was now established, and, through the favour of the Earl of Halifax,
be received the commission to paint the princess's apartment at
Hampton Court, which the lord chamberlain, the Duke of Shrews-
bury, had intended should be painted by Sebastiano Ricci, then in
great favour with tho court in England ; but tho Earl of Halifax, who
was then first commissioner of the treasury, declared that if Ricci
painted it he would not pay him. Sir James executed many other
great works, as the staircase, the gallery, and several ceilings in the
palace at Kensington, a hall at Blenheim, the chapel at Lord Oxford's
at \\'impole in Cambridgeshire, a saloon for Mr. Styles at Moor Park
in Hertfordshire, and the ceiling of the great hall at Greenwich Hospi-
tal. Sir James commenced the last work in 1703, and was occupied
upon it for several subsequent years, but it was not entirely painted
by his own hands. The paintings are allegorical : on the ceiling of
the lower hall, which is 112 feet by 56, are represented the founders
of the institution, William III. and Queen Mary, in the centre, sur-
rounded by the attributes of national prosperity ; in the other com-
partments are figtires which represent the zodiac, the four seasons
and the four elements, with naval trophies and emblems of science,
among which are introduced the porti'aits of famous mathemati-
Copernicus, Newton, and others. On the ceiling of the upper hall
are represented Queen Anne and her husband Prince George of Den-
mark ; other figures represent the four quarters of the world ; on the
side walls of the same apartment are the landing of William III. at
Torbay, and the arrival of George I. at Greenwich ; on the end wall
facing the entrance are portrait groups of George I. and two genera-
tions of hia family, with accessories, and Sir James Thornhill's own
portrait. These works, which are executed in oil, have little to recom-
mend them besides their vastness ; yet in invention and arrangement
they are equal to the majority of such works in the great buildings on the
continent : in design and colouring however they are perhaps inferior.
Walpole has preserved some interesting details respecting the remu-
neration Thornhill received for some of his works : he says, " High
as his reputation was, and laborious as his works, he was far from
being generously rewarded for some of them, and for others he found
it difficult to obtain the stipulated prices. His demands were con-
tested at Greenwich; and though La Fosse received 2000?. for his
work at Montague House, and was allowed 5001. for his diet besides,
Sir James could obtain but forty shillings a square yard for the cupola
of St. Paul's, and I think no more for Greenwich. When the affairs
of the South Sea Company were made up, Thornhill, who had painted
their staircase and a little hall, by order of Mr. Knight, their ca.shier,
demanded 1600?., but the directors learning that he had been paid but
twenty-five shillings a yard for the hall at Blenheim, they would
allow no more. He had a longer contest with Mr. Styles, who had
agreed to give him 3500?., but, not being satisfied with the execution,
a lawsuit was commenced, and Dahl, Richardson, and others were
appointed to inspect the work. They appeared in court bearing testi-
mony to the merit of the performance ; Mr. Styles was condemned to
pay the money, and, by their arbitration, 500?. more, for decorations
about the house, and for Thornhill's acting as surveyor of the build-
ing." Thornhill obtained permission, through the Earl of Halifax, to
copy the Cartoons of Raffaelle at Hampton Court, upon which he
bestowed three years' labour ; he made also a smaller set, one-fourth
the size of the originals, and distinct studies of the heads, hands, and
feet, intending to publish an exact account of the whole for the use of
students, but the work never appeared. These two sets of the
Cartoons were sold the year after his death, with his collection of
pictures, among which were a few capital specimens of the great
masters : the smaller set sold for seventy-five guineas, the larger for
200?. only, a price, says Walpole, which can have been owing solely to
the circumstance of few persons having spaces in their houses largo
enough to receive them. They were purchased by the Duke of
Bedford, and were^ placed in his gallery at Bedford House in Blooms-
bury Square, where they remained until that house was pulled down,
when they were presented by the owner to the Royal Academy.
Thornhill painted also several portraits and some altiir-pieces : he
painted the altar-piece of the chapel of All Souls at Oxford : and one
which he presented to the church of his native town, Weymouth.
There is also at Oxford, according to Dallaway, a good portrait of Sir
Christopher Wren by Thornhill ; and in the hall of Greenwich
Hospital there is by him the portrait of John Worley, in his ninety-
eighth year, one of the first pensioners admitted into the hospital ; it
is painted in a bold careless style, and was presented to the hospital
by Thornhill himself. In 1724 he opened an academy for drawing at
his house in Covent Garden. He had previously proposed to the Earl
of Halifax the foundation of a Royal Academy^ of the Arts, with
apartments for professors, but without result : Sir James estimated
the cost at 3139?. ; for, amongst his other occupations, he occasionally
' dabbled ' in architecture. At the end of his life he was afflicted with
the gout, and in the spring of 1734 he retired to his paternal seat at
Thornhill, near Weymouth, which he had the satisfaction of repurchas-
ing ; but his period of repose was extremely short, for, says Walpole,
21
THORNTON, BONNELL.
THORWALDSEN, BERTEL.
i»
(* Anecdotes of Painting in England ') " four days after bis arrival, he
expired in his chair, May 4, 1734, aged fifty-seven, leaving one son
named James, whom he had procured to be appointed seijeant-painter
and painter to the navy ; and one daughter, married to that original
and unequalled genius, Hogarth."
Sir James Thornhill amassed considerable property, was a man of
agreeable manners, was a Fellow of the Royal Society, and rcprespnttd
his native town, Weymouth, in parliament for several years until his
death. He was knighted by, George I. : his widow, Lady Thornbill,
died at Chiswick in 1757.
THORNTON, BONNELL, was born in London, in the year 1724.
He was educated at Westminster School, and at Christchurch, Oxford.
In compliance with the wish of his father, who was an apothecary in
Maiden-lane, ho studied medicine, but he seems not to have liked the
profession, and left it for literature. George Colman the Elder was
his fellow-student both at Westminster School and at Christchurch,
tliough about nine years younger than Thornton. Similarity of taste
led to friendship, and they commenced in conjunction the series of
periodical essays called ' The Connoisseur,' which was continued from
January 31, 1754, till September 30, 1756. The papers are chiefly of a
humorous character, and the wit and shrewd observation of life which
they display well entitle them to th« place which they still retain
among the works of British Essayists. Thornton contributed largely to
' The St. James's Chronicle,' of which he was one of the original pro-
prietors along with Colman ; ' The Public Advertiser,' and started a
periodical called 'Have at ye all, or the Drury Lane Journal,' in rivalry
of Fielding's * Covent Garden Journal' He published separately ' An
Ode on St. Cecilia's Day, adapted to the antient British music, viz.
the salt-box, the Jews'-harp, the marrow-bones and cleavers, the hum-
strum or hurdy-gurdy, &c., with an Introduction giving an account of
those truly British instruments,' 4to, London, 1762 ; and he carried
out the jest. Dr. Burney having set the ode to music it was per-
formed on the instruments named, at Rauelagh, to a crowded audi-
tory. He was indeed singularly fond of these somewhat elaborate
drolleries. He was one of the members of the famous Nonsense Club,
and was the chief agent in getting up an exhibition of the London
street signs in burlesque of the annual exhibition of the Royal
Academy. Thornton opened his exhibition on the same day as that
and in the catalogues (which exhibited genuine though somewhat
broad humour) as ' The Exhibition of the Society of Sign Painters of
all the curious signs to be met with in town or country, together with
such original designs as might be transmitted to them as specimens of
the native genius of the nation.' Hogarth, who entered into the spirit
of the fun, added to some of the signs a few touches to heighten the
absurdity, and the exhibition proved remarkably attractive.
In 1767, in conjunction with Colman and Richard Warner, he pub-
lished two volumes of an English translation of Plautus, ' The Comedies
of Plautus, translated into familiar Blank Verse.' Of the plays con-
tained in these two volumes, Thornton translated 'Amphitryon,'
' The Braggart Captain,' ' The Treasure,' ' The Miser,' and ' The
Shipwreck;' 'The Merchant' was translated by Colman, and 'The
Captives' by Warner. The rest of the p]ays were translated by
Warner, and were published after Thornton's death, in two additional
volumes. Thornton's translations are incomparably the best. In
1768 Thornton published ' The Battle of the Wigs, an additional
Canto to Dr. Garth's Poem of The Dispensary,' 4to, London.
Thornton, who appears to have injured his constitution by habitual
indulgence in drinking, but who was of a thoroughly kind and gene-
rous disposition, died May 9, 1768, at the age of forty-four. There is
an inscription to his memory, by Thomas Warton, in the cloisters of
AVestminster Abbey.
THORWALDSEN, BERTEL (ALBERT), was born November 19,
1770, at Copenhagen. He was the son of Gottschalk Thorwaldsen, a
carver in wood, and his wife Karon Gronlund, the daughter of a priest
of Jutland. Gottschalk was a native of Iceland, and was in very poor
circumstances when his son Bertel was born. Bertel assisted his father
in his work at a very early age, and when only eleven years old he
attended the free school of the Academy of Arts at Copenhagen, and
made such progress in two years that he was enabled tc improve his
father's carvings ; and himself undertook to execute the head-pieces
of ships. At the age of seventeen he obtained the silver medal of the
academy, for a bas-reUef of Cupid reposing; and in 1791, when he
was only twenty years of age, the small gold medal for a sketch of
Heliodorus driven from the temple. Two years later he obtained the
principal gold medal of the academy, and with it the privilege of
studying for three years abroad at the government expense. Before
setting out however he devoted a year or two to preliminary general
study, for scholarship was not one of his acquirements, and he had
much' to read and much to learn. On the 20th of May 1796, he set
out for Italy in the Danish frigate Thetis, and he arrived at Naples in
the end of January of the following year, in the packet-boat from
Palermo. The Thetis cruised in the North Sea until September ; in
October it touched at Algiers ; it then performed quarantine at Malta,
made a voyage to Tripoli to protect Danish commerce, and performed
quarantine a second time at Malta, when Thorwaldsen left it in a small
Bailing boat for Palermo, where he took the packet-boat to Naples.
At Naples, wholly unacquainted with the Italian languags, and for
the first time entirely separated from bis owu countrymen, Tbor-
waldseu's heart failed bim, and he longed to return to Denmark, which
according to bis own account he would have done if he had found a
Danish vessel about to leave the port at tlie time. However, in a
little time lie found courage to engage a place iu the coach of a
vetturino for Rome, where he arrived March 8, 1797.
Thorwaldsen brouglit letters of introduction to his diBtiQgui«bed
countryman Zocga, who however did not give the young sculptor
much encouragement, nor did be estimate his ability very bigli.
When Zoiiga was once asked what lie thought of biro, three years after
bis arrival, he answered, with a shake of the head, " There is much
to find fault with, little to be contented with, and he wants induHtry."
Up to this time Zoiiga was right, except in the la«t particular. Thor-
waldsen was industrious, but fastidious, and often destroyed what bad
cost him much labour. This was the fate of a statue of Jason with
the Golden Fleece which be had modelled to take back with bim to
Copenhagen at the expiration of bis term of three years allowed by
the academy. He however made a second attempt at the same figure,
and this statue satisfied even the difficult Zocga, with whom Tlior-
" This work of the young Dane is ia a new and grand style." By the
assistance of a Danish lady, Frederika Brun, who gave him the
necessary funds, which be had not, and praised the statuo in song,
it was cast in plaster, and Thorwaldsen prepared for his return home :
but when on the point of starting and about to step into the vehicle
of the vetturino, one of his companions, the Prussian sculptor Hage-
mann, found that hii passport was not in order, and be was obliged
to put off his journey until the next day. Thorwaldsen determined
to wait with him, the vetturino started without them, this delay was
followed by another, and it eventually happened that Thorwaldsen
did not return to his native country until 1819, after an absence of
twenty-three years. The liberality of Thomas Hope was the imme-
diate cause of Thorwaldsen's finally settling in Rome. The words of
Canova upon the statue of Jason were repeated in the artistic circles
of Rome, and echoed by the professional ciceroni of the place. One of
these ciceroni took Mr. Thomas Hope in the year 1803 to the studio of
the young Dane to see the statue which the great sculptor had praised.
The English connoisseur stood long before the plaster figure, then
inquired what Thorwaldsen required for a marble copy of it : " 600
ducats," was the answer ; " You shall have 800," was the generous
From this time the star of Thorwaldsen was in the ascendant; the
statue was however not finished until many years afterwards, but
many celebrated works were done in the meanwhile ; as the bas-reliefs
of Summer and Autumn, and the dance of the Muses on Helicon ;
Cupid and Psyche ; and Venus with the apple. His fame spread far
and wide, and Christian VIII, (then crown-prince), of Denmark, wrote
the same time the discovery of a white marble quarry in Norwaj'.
Thorwaldsen was eager to return, but commission upon commission
rendered it difficult if not impossible, and he remained in the papal
city. During this busy time Thorwaldsen recreated himself in the
summer seasons at Leghorn, in the beautiful villa of Baron Schubart,
the Danish minister at Florence : he executed also some of his works
here. In 1812, when arrangements were making for Napoleon's visit
to Rome, the architect Stern, who superintended the preparations,
happened to sit next to Thorwaldsen at one of the assemblies of the
frieze for one of the large apartments of the Qniiinal Palace, iu three
months. Thorwaldsen undertook the commission, and in three
months the plaster sketch of his celebrated bas-relief of the Triumph
of Alexander was completed. The immediate subject was Alexander's
triumphal entry into Babylon : the length of the frieze is 160 Roman
palms, its height five palms : it has been twice executed in marble,
with slight variations, and is engraved in a series of plates by S.
Amsler, of Munich, after drawings by Overbeck and others. In 1815
Thorwaldsen modelled, in a single day, two of his most popular works,
the bas-reliefs of Night and Day ; but he had done nothing whatever
for weeks and months before.
In July 1819, he started in the company of two friends on his first
visit to his native land, and he arrived at Copenhagen on the 3rd of
October in the same year : his parents had died some years before.
His fame was now so well estabhshed, that even through Italy and
Germany his journey was a species of triumphal passage, and at its
termination he was lodged in the palace of Charlottenbxxrg and euter-
taiued with public feasts. In about a year he left Copenhagen and
returned to Rome through Berlin, Dresden, and Warsaw, \vhere he
Alexander.
Christ and the Twelve Apostles; the group of St. John m the Wilder-
ness; and the monuments to Copernicus, Pius VIL, Maximilian of
Bavaria, the Poniatowski monument, and others. In 1823 he had a
narrow escape of his life : a boy, the son of his landlady, contrived to
get hold of one of his pistols, which he had carelessly hung up loaded ;
the boy, ignorant of the danger, pointed it and discharged it at Thor-
waldsen, but the ball, after grazing two of bis fingers, lodged in bis
dress without doing bim any further injury.
23
THORWALDSEN, BERTEL.
THOU, JACQUES-AUGUSTE DE.
24
In 1838 the ChriBt, the St. John preaching, and the Apostles, — the
principal works for the cathedral or church of Our Lady at Copen-
hagen—and other works for the palace of Christiansburg, on which
Thorwaldsen hod been many years engaged, were completed, and the
Danish government sent the frignte Rota to carry them and the
sculptor to Copenhagen. Thorwaldson was received with enthusiasm
by his countrymen. He remained among them on this occasion
about three years, and chiefly at Nyso, the seat of his friend the
Baron Stampe, whero a studio was built for him ; and be finished
here some of his last works — the frieze of tho Procession to Golgotha,
for the cathedral; the Entrance into Jerusalem; Rebecca at the
Well ; his own statue ; and the busts of the poets Oehlenschlager and
Holberg.
In 1»41, finding the climate disagree with him, he felt compelled
to return to Italy, and ho executed at this time his group of the
Graces for the King of Wurtemburg. He returned however to Den-
mark and Nyso in the following year, and executed two other works,
bas-reliefs, which aro among his last productions — Christmas Joy in
Heaven ; and the Genius of Poetry, which he presented to his friend
1844, but h« died suddenly in the theatre of Copenhagen, on March
24tb, in that year, aged seventy-three : he died of disease of the heart.
He lay in state in the Academy, and was buried with extraordinary
ceremony beneatii his own greatest productions in the cathedral
church of Copenhagen.
Thorwaldseu's will beai-s much resemblance to Sir F. Chantrey's :
he bequeathed all works of art in his possession, including casts of his
own works, to tho city of Copenhagen, to form a distinct museum,
which was to bear bis name, on the condition that the city furnished
an appropriate building for their reception. This building was nearly
completed before the death of Thorwaldsen ; it now forms one of the
prime attractions of the city. Besides casts of the numerous works
of Thorwaldsen, which would alone constitute an imposing collection
of its class, it contains many works of ancient and modern sculpture,
numerous paintings by old and recent masters, casts, vases, engraved
gems, cameos, terracottas, bronzes, medals, curiosities, engravings,
prints of all descriptions, books on the fine arts, and drawings. With
the exception of 12,000 dollars to each of his grandchildren, and the
life-interest of 40,000 dollars to their mother, Madame Poulseu, his
natural daughter, to descend to her children, the whole of his personal
estate was directed to be converted into capital, and to be added to
tho 25,000 dollars already presented for the purpose by Thorwaldsen,
to form a museum perpetual fund, for the preservation of the museum
and for the purchase of the works of Danish artists, for the encourage-
ment of Danish art, and to add to the collections of the museum.
Thorwaldsen is considered by his admii-ers the greatest of modern
8Culptori<, and many have not hesitated to compare hitn with the
antique. This is however hardly the rank he will hold with posterity ;
his style is uniform to monotony, though many individual figures are
bold, solid, and of beautiful proportions. His beau-id^al appears to
have been something between the Antinous and the Discobolus of
Nancydes, as it is sometimes called ; but as his subjects are seldom
heroic, he seldom required more than a moderate expression of heroic
vigour or robust strength and activity : in this respect, and in execu-
tion generally, he was much surpassed by Canova ; but still more
so in the grace of the female form, in which Thorwaldsen certainly did
not excel. His females are much too square in the frame, the head
and shoulders being generally heavy ; and in no instance do we find in
his female figures, in full relief, that beautiful undulation of line and
development of form characteristic of the female, which is displayed in
the antique, in the works of Canova, and in those of some other
modern sculptors ; as, for instance, the Ariadne of Dannecker. Basso-
rilievo was a favourite style with Thorwaldsen, and a great proportion
of his works are executed in this style. Of this class some of his
minor works are the most expressive; but the principal are — the
Triumph of Alexander, and the Procession to Golgotha, which is
the frieze of the cathedral church of Copenhagen, immediately below
the numerous group of John preaching in the Wilderness, in foil
relief, in the pediment : in the vestibule are the four great Prophets;
Christ and the Twelve Apostles are above and around the altar.
The Triumph of Alexander, of which there is a copy in marble in
the palace of Christiansburg (the first marble copy was made for
Count Somariva's villa on the Lake of Como), is a long triumphal
procession in two divisions, one meeting the other. In the centre,
Alexander, in the chariot of Victory, and followed by his army, is met
by the goddess of Peace, followed by MazsBus and Bagophanes with
presents for the conqueror. The subject is taken from the work of
Quintus Curtius. Much of the frieze is symbolical : perspective is
nowhere introduced. The whole arrangement is beautiful, especially
that portion which comes from Babylon, comprising the General
MazJcus with bis family ; female figures strewing flowers ; Bagophanes
placing silver altars with burning incense, musicians, and attendants
leading horses, sheep, wild animals, and other presents for the con-
queror ; next to these are symbolic representations of the river Eu-
phrates, and the peaceful occupations of the Babylonians. The human
figures of this work are admirable, as is also the management of the
costumes, but the horses are below mediocrity both in design aud
modelling, especially that of Alexander himself, Bucephalus, which is
led following the chariot of Alexander; it is a complete distortion.
None of the horses of Thorwaldsen are successful. The colossal
animal of the Poniatowski monument at Warsaw, and that (of smaller
proportions) of the mommieut to Maximilian of Bavaria at Munich, are
heavy and graceless, and wanting in the finer characteristics of form
which belong to the horse.
Many years ago some admirers of Lord Byron raised a subscription
for a monument to the poet, to be placed in Westminster Abbey.
Chantrey was requested te execute it, but on account of the smallneas
of the sum subscribed, he declined, and Thorwaldsen was then applied
to, and cheerfully undertook the work. In about 1833 the finished
statue arrived at the custom-house in London, but, to the astonishment
of the subscribers, the Dean of Westminster, Dr. Ireland, declined to
give permission to have it set up in tho Abbey, and owing to this
difiiculty, which proved insurmountable, for Dr. Ireland's successor
was of the same opinion, it remained for upwards of twelve years
in the customhouse ; when (1846) it was removed to the library of
Trinity College, Cambridge. The poet is represented of the size of
life, seated on a ruin, with his left foot resting on the fragment of a
column ; in his right hand he holds a style up to his mouth ; in his
left is a book, inscribed ' Childe Harold :' he is dressed in a frock-coat
and cloak. Beside him on the left is a skull, above which is tho
Athenian owL The execution is not of the highest order; both
face and hands are squarely modelled; thus fineness of expression is
precluded through want of elaboration. The likeness is of courso
posthumous. Some of the finest of Thorwaldseu's imaginative works
are in private collections in this country. At the Crystal palace,
Sydenham, are casts of several of his most celebrated statues and bassi-
rilievi, including his famous ' Triumph of Alexander.'
THOU, JACQUES- AUGUSTEDE (or, as he caUed himself in Latin,
Jacobus Augustus Thuanus), was born at Paris, on the 8th of October
1553 : he was the third son of Christophe de Thou, first president of
the parlement de Paris, and of his wife Jacqueline Tuellen de Cell.
Besides their three sons aud four daughters, who grew to be men and
women, De Thou's parents lost six children in infancy ; and he him-
self was so weak and sickly a child till he reached his fifth year, that
he was not expected to live. In the exemption which this state
of health procured him in his childhood and early boyhood from
severer taskwork, he amused himself in cultivating a turn for drawing,
which was hereditary in his family; and in this way, he tells us
himself, he learned to write before he had learned to read. Although
originally intended for the church, he went in his early studies the
whole round of litei-ature and science as then taught; and while yet
only in his eighteenth year he had conceived from the perusal of
some of his writings so great an admiration of the celebrated jurist
Cujacius, that he proceeded to Valence in Dauphind, aud attended his
lectures on Papinian. Here he met with Joseph Scaliger, with whom
he contracted an iutimate friendship, which was kept up for the
thirtyei<?ht remaining years that Scaliger lived.
In 1572, after he had been a year at Valence, he was recalled home
by his father ; and he arrived in Paris in time to be present at the
marriage of Henry, the young king of Navarre, and to witness tho
horrors of the massacre of St. Bartholomew which followed. He
relates that he saw the dead body of Coligny hanging from the gibbet
of Montmartre. The next year he embraced an opportunity of viaiting
Italy, in the suite of Paul de Foix, who was sent by Charles IX. on a
mission to certain of the Italian courts; and he remained in that
country till the death of Charles, in May, 1574, and the accession of
Henry III., the news of which reached them at Rome, recalled De
Foix home. In 1576 he made a journey to Flanders and Holland.
In 1578 he succeeded Jean de la Garde, Sieur de Saigne, as one of the
ecclesiastical counsellors of the parlement de Paris — an entrance into
public life which, he says, he made with reluctance, as withdrawing
him in part from the society of his books and the cultivation of
literature, in which he would have been much better pleased to spend
his days. The next year he lost his eldest brother ; and from this
time it began to be proposed that, for the better chance of continuing
the family, his original destination should be changed, and that he
should quit his ecclesiastical for a civil career. Some years elapsed
however before this scheme was finally determined upon. Meanwhile
he continued to pursue his usual studies ; and he states that he had
already conceived the project of his great historical work, and began
industriously to collect materials for it wherever he went.
It was in the year 1582, while on a visit to Bordeaux, that he made
the acquaintance of Montaigne, whose character as well as genius ho
has warmly eulogised. The same year his father died : and having
also by this time lost his second brother, he, in 15S4, resigned his
rank as an ecclesiastical counsellor, and on the 10th of April was
appointed by the king to the office of master of requests, which then
was wont to be held indifierently by ecclesiastics or laymen. Two
years after he obtained the reversion of the place held by his uncle, of
one of the prdsidents au mortier in the parlement de Paris ; and in
1587 he married Marie, daughter of Francois Barbanson, Sieur de
CauL When, in the next year, in the increasing distractions of the
state, Henry III. found himself obliged to leave Paris, De Thou, who,
the troubles of the time to the royal party, accompanied his majesty
o Normandy, and afterwards to Ficardy. At Chartres, in August 1588,
26
THOU, JACQUES-AUGUSTE DE.
THOUARS, LOUIS-MARIE.
26
he was admitted a councillor of state ; and from this date he took a
leadiug part in all the principal public transactions which followed.
When the estates df the kingdom were assembled at Blois, in October
of this year, De Thou, as ho tells, was there courted with much bland-
ishment by the Duke of Guise, but steadily resisted the attempt to
seduce him from his loyalty. He had left Blois and was in Paris
when the news of the murders of the Duke of Quiso and his brother
the cardinal (on the 23rd and 24th of December^ reached the capital ;
and ho had great difficulty in effecting his escape from the popular
fury. He succeeded however in rejoining the king at Blois; and
having soon after been despatched on a mission into Germany and
Italy to raise succours of men and money for the royal cause, he was
at Venice when he heard of the death of Henry, in August 1689. He
immediately set out by the way of Switzerland for France, and met
the King of Navarre, now calling himself Henry IV., at Chateaudun.
He was received very graciously ; and for some years from this time
he was constantly with Henry, or employed on missions to diflferent
quarters in his service.
In 1591, while Henry was at Nantes, he received accounts of the
death of Amyot, bishop of Auxerre (renowned for his translations of
Plutarch and other Greek authors) ; upon which his majesty imme-
diately bestowed his office of keepeu of the royal library on De
Thou. It was in the year 1593, as he has noted, that he at last
actually commenced the composition of his ' History,' which he now
states he had conceived in his mind so long as fifteen years before. In
1594 the death of his uncle opened to him his reversionary office of
one of the presidents of the parlement de Paris.
Among other important transactions in which he had a part after
this, was that of the Edict of Nantes, published in 1598, which he
was greatly instrumental in arranging. He has left an account of his
own life, in ample detail, down to the year 1601, in which the last
event he notices is the death of bis wife, in August of that year. In
1604 he published the first eighteen books of his 'History.' The
work was received with general applause by the literdry public through-
out Europe, and, although some things in it gave umbrage to the
more zealous friends of the Roman Catholic faith, it was not till
several years afterwards, when a second portion of it had been pub-
lished, that it was formally stigmatised by being inserted in the
' Index Expurgatorius.' De Thou however severely felt this authori-
tative condemnation of his performance, when it did take place, in
November 1609. The death of Henry IV., in 1610, did not deprive
De Thou of his place in the ministry; but he had no longer the
same influence as before; and a new appointment, which he received
the following year, of one of the three directors charged with the
management of the finances, on the retirement of the great Sully, was
felt by himself to be not so much an accession of power or honour, as
a burdensome and obnoxious office forced upon him, for which he was
fitted neither by tastes, habits, nor qualifications. In this same year
his brother-in-law, Archille de Harlay, resigned his office of first presi-
dent of the parlement de Paris, in the hope that De Thou would be
nominated his successor ; but the place was given to another. These
disappointments and disgusts, together with the loss of a second wife,
are supposed to have shortened the life of De Thou, who died at Paris
on the 7th of May 1617, in his sixty-fourth year. By his second wife,
whose family name was de Bourdeilles, he left three sons and three
daughters, one of the former of whom, Frangois Auguste de Thou,
the inheritor of his father's virtues and of a considerable share of his
talents, fell a sacrifice to the inexorable revenge of Cardinal Richelieu,
one of whose last acts was his putting this unfortunate young man to
death for his alleged participation in what was called the conspiracy
of Cinqmars : — he was executed at Lyon, in his thirty-fifth year, on
the 12th of September 1642, not three months before Richelieu's own
death.
The president De Thou is the author of a number of Latin poems,
one of the principal of which, entitled ' De Re Accipitraria ' (on
Hawking), was published in 1584 ; but his fame rests upon his * Histo-
ria Bui Temporis,' or ' History of his own Time,' written also in Latin,
in 138 books, of which the first 80 appeared in his lifetime, the
remainder not till 1620. The space over which it extends is from the
year 1544 to 1607, comprehending the closing years of the reign of
Francis I., the entire reigns of Henry II., Francis II., Charles IX.,
and Henry III., and nearly the whole of that of Henry IV. For about
one-half of this period of sixty-three years it has the value belonging
to the narrative of one who was himself a principal actor in many of
the affairs which he relates, and who with regard to many others was
so placed as to have an opportunity of seeing much that was concealed
■ from the co-mmon eye ; but in truth, from the author's family connec-
tions, and his extended acquaintance among the eminent and remark-
able persons of his time, this is an advantage which belongs in some
degree to the earlier as well as to the later part of the work. It is
also admitted to have throughout the merit of a rare impartiality :
with no deficiency of patriotic feeling, and perfect steadiness to his
own jiolitical principles, De Thou is always ready frankly to recognise
the high qualities, of whatever kind, that may have belonged either
to the citizen of a rival state or a party opponent. As for religious
prejudice, he shows so little of that, as to have exposed himself to the
imputation of having no religion, or at least of not being really a
believer in the form of Christianity, the Roman Catholic, which he
professed. But for either of these charges there seems to be do
ground. The reputation of his ' HiBtory ' however stands not so much
upon the facts contained in it that are not elsewhere to be found,
as upon the skill displayed in its composition— not so much upon the
material as upon the workmanship ; and it ia very evident that with
all the pains be took in the collecting of information, this was tbo
praise of which he was the most ambitious, as indeed may perhaps be
said to have been the case with the most famous hietoriana of every
age and country, from Herodotus and Thucydidea among the Greeks,
and Livy and Tacitus among the Latins, to Hume and Gibbon— not
to speak of contemporaries — among ourselves. But De Thou's manner
of writing, though flowing and eloquent, is not very picturesque ; and
of course he also loses something in raciness and natural grace, ease,
and expressiveness, by writing in a dead language. De Thou's Latin
style, with all its merit, is not admitted to be faultless, though he has
taken great pains to give it as uniformly classical an air as possible,
not only by metamorphosing all his modern names, both of places
and persons, so as to give them antique forms, often to tbo no small
perplexity and hindrance of the reader, but, what sometimes produces
still more obscurity or ambiguity, by generally endeavouring to
describe modern proceedings and transactions in the established legal,
political, and military phraseology of the old Romans. The best
edition of De Thou's ' History ' is that published at London in 1733,
in seven volumes, folio, under the superintendence of Samuel Buckley,
Esq., and at the expense of Dr. Mead. The last volume of this
edition contains De Thou's autobiographical memoir (first published
in 1620, and also written in Latin), in six books, together with a
mass of additional materials illustrative of the history of his life and
works.
THOUARS, LOUIS-MARIE-AUBERT-DU-PETIT, an eipinent
French botanist, was born at the chUteau de Boumois, in Anjou, 1756.
His family was wealthy and noble, and being destined for the army,
he was early sent to the school of La Fl6che. He was made a lieu-
tenant of infantry at the age of sixteen. This was in a time of peace,
and he occupied his leisure in studying the science of botany and its
literature. At the time of the loss of La Perouse and his companions,
Aristide du Petit Thouars proposed to his brother Aubert that tiiey
should go in search of him. To this he willingly consented, hoping to
add to his stock of plants and his fame by the voyage. The two
brothers sold their patrimony, raised a subscription, and having
secured the patronage of Louis XVI., were ready to start on their
voyage, when a curious accident separated them. The ship that was
to have taken them lay at Brest, and Aubert, with his vasculum (the
tin box which botanists carry to put their plants in) at his back,
intended to botanise on his way from the capital to the port. He
was however found by some gens d'armes in the woods, and being sus-
pected as an enemy of his country in those days of disorder, he was
arrested and thrown into prison at Quimper. He was however soon
released, but too late, as his brother had sailed. He followed him to
the Isle of France, but his brother had again departed; and being
here without money and without friends, his only resource was his
botanical knowledge, and he accordingly applied for employment to
some of the rich planters of that island. He quickly obtained an
engagement, and remained in the island for nearly ten years. On this
spot he was very favourably placed for making those observations for
which his previous studies had so well prepared him ; and during his stay
here he collected most of the materials for the numerous works which
he published on his return. Whilst a resident in the Isle of France
island. He returned to Paris in 1802. Many of the results of his
researches in the Isle of France and Madagascar were communicated
to the Institute and other scientific bodies in Paris. His first work on
the botany of the islands which he had visited, wiis published at Paris
in 1804, with the title ' Plantes des lies de I'Afrique Australe formant
des Genres nouveaux,' &c., 4to. He also published on the same
subject the * Histoire des Vig^taux des ties de France, de Bourbon, et
de Madagascar,' 4to, 1804. In the same year Bory St. Vincent gave
an account of the vegetation of the African islands, in his ' Voyage dans
les quatre principales lies des Mers I'Afrique,' 4to, Paris, although he
did not go out till Du Petit Thouars had returned. In 1 806 Du Petit
Thouars was appointed director of the royal nursery-ground at Paris,
which office he held till the closing of the institution a short time
before his death. In 1806 he published another work on the plants of
Africa, with the title ' Histoire des Vdg^taux recueillies dans les lies
Australes d'Afrique,' 4to, Paris. In 1810 his 'Genera nova Madagas-
cariensia' appeared, in which the Madagascar plants were arranged
according to the system of Jussieu. His latest work on systematic
botany was one on the Orchidaceas of the African islands, ' Historie
des Plantes Orchid^es recueilles dans les trois lies Australes d'Afrique,'
8yo, Paris 1822. His publications on vegetable physiology are equally
numerous. Most of these had their foundation in observations and
experiments which he made while in the Isle of France. In 1805 he
published his ' Essai sur I'Organisation des Plantes,' 8vo, Paris ; in
1809, another essay on the vegetation of plants ; in 1811, ' Melanges de
Botanique et de Voyages,' 8vo, Paris; in 1819, a kind of botanical
miscellany, passing in review his own labours, under the title ' Revue
g^ndrale des Matdriaux de Botanique' et autres, fruit de trente-cinq
anndes d'observations,' 8vo, Paris. He died in May 1831.
tt
THOURET, MICHEL-AUatJSTIN.
THRASYBULUS.
28
Ab a Bystamatio botanist the views of Du Petit Thours were uncer-
tain and Bpoculative, and the delay in the pabliuation of his works on
African botany deprived him of the merit of introducing to the world
many new species. In hia physiological works his views are ingenious,
but in most cases wanting in sufficient data to edtablish them. His
views on tho formation of buds, the motion of the sap, and tbe origin
of wood, are those which have excited most attention. But each of
these is perhaps more indebted to the speciousuess of its reasoning
than to the correctness of the facta, for tho importance that botauiata
have attached to it. But at the same time hia great activity of mind,
his extensive erudition and original observation, have had a great
iuduence on the progress of botany in the present century. He was a
contributor to the 'Biographie Univei-selle/ and wrote tho lives of
many of tiie botanists in that work. The genus of plants Thouarea
was named after him, and Bory St. Yiuceut named Aubertia in
honour of him.
THOUUET, MICHELAUGUSTIN, an eminent French physician,
was born in 1748, at Pont I'Evfique, in the ancient province of Nor-
mandy and the modern department of Calvados, where his father was
royal notary (notaire royal). His education was commenced in his
native town, and finished at the University of Caen. He afterwards
went to Paris, and in 1774 was admitted gratuitously by the Faculty
of Medicine in that city to the degree of M.D., an honour which was
gained by public competition (concours). A few years later, upon
the foundation of tho lioyal Society of Medicine, Thouret became one
of its earliest members, and enriched the Memoirs of the Society by
several valuable essays. The most important public work in which he
took part was the exhumation of the bodies in the cemetery of the
Holy Innocents, of which he drew up a most interesting report. This
cemetery, together with a church of the same name, stood on the spot
now occupied by the March^ des Inuocens, and had become in process
of time so unhealthy from being the principal burial-ground in Paris,
that it was absolutely necessary to destroy it. This great work had
been several times attempted, but as often abandoned on account of
the dangers and difficulties of the undertaking ; at last however, in
1785, a committee was named for directing the works, which were
carried on without intermission by night and by day for more than six
months, and which were at length completely successful. Thouret
afterwards filled several public situations with equal zeal and integrity ;
and in the midst of the labours of his numerous employments was
carried off, after a few days' illness, by a cerebral affection, at Meudon,
near Paris, June 19, 1810. Great honours were paid him after his
death by the Faculty of Medicine at Paris, of which body he was dean.
His works consist almost entirely of essays published in the ' Histoire
et Mdmoires de la Socidtd Royale,' of which perhaps the most interest-
ing are the ' Rapports sur les Exhumations du Cimetiere des SS.
Innocens,' mentioned above. These were afterwards published in a
separate form at Paris, 12mo, 1789. {Biographie Medicale.)
THRA'SEA PAETUS. His prsenomen is uncertain ; some writers
call him Lucius, and others Publius, but he is generally called simply
Thrasea Paetus or Thrasea. He was a native of Patavium, Padua (Tacitus
* Annal.,' xvL 21 : Dion. Cass., Ixii. 26), and, like most men of talent at
the time, he went to Rome, where he afterwards became a senator and
a member of the priestly college of the quindecimviri. The first time
that Thrasea came prominently forward in the senate was in a.d. 59,
when a senatus-consultum was passed by which the city of Syracuse
obtained permission to employ a greater number of gladiators in the
public games than had been fixed by a law passed in tho time of
J. Caesar. (Tacitus, 'Annal.,' xiii. 49; Dion. Cass., hv. 2; Sueton.,
*Caes.,' 10.) Although the matter was of no importance, Thrasea
took an active part in the deliberation, merely to impress upon his
colleagues the necessity of paying attention even to the smallest
matters belonging to the administration of the senate. In the same
year Nero determined to carry into efiect his design of getting rid of
his mother Agrippina. [Nkro ; AoRipriNA.] When the crime was
committed, and when the emperor sent a letter to the senate in which
he endeavoured to exculpate himself, the degraded senators con-
gratulated him upon having got rid of so dangerous a woman.
The only man who on that occasion had the courage to show his detes-
tation of the crime was Thrasea. (Dion. Cass., Ixi 15 : Tacit,, * Annal.,
xiv. 12.)
In the year a.d. 62, when the praetor Antistius was charged by
Cossutianus Capito with high treason for having composed and read at
a numerous party of friends some libellous verses upon the emperor,
and when the emperor showed au inclination to interfere in the trial,
Thrasea boldly claimed for the senate the right to try the case accord-
ing to the existing laws. The firmness of Thrasea induced most of the
senators to follow his example and to voto with him. Cossutianus
was thwarted in his hope of getting Autistius sentenced to death, and
the emperor, though highly annoyed, endeavoured to disguise his
anger. (Tacitus, 'Annal.,' xiv. 48, 49.) A shoi-t time afterwards
Thrasea again attracted general attention in the senate by a speech
against the assumption and insolence of wealthy provincials. It had
at that time become customary with the provincials to request the
Roman senate, by embassies, to offer public thanks to the proconsuls
• nistration to their satisfaction. The ambition to gain this distinction
often deprived the proconsiila of then: independence, and degraded
them into flatterers of influential provincials, who thus obtained an
improper power. Thrasea proposed to the senate a measure to remedy
the evil, but although it met with general appro^bation, he did not
succeed in making the senate pass a decree, which was however done
shortly after on the proposal of Nero himself. (Tacitus, * Annal.,* xv.
20-22.) Nero already hated Thrasea, and envy now began to increase
the hatred. When therefore in 63, Poppaoa, the wife of Nero, was
expecting her confinement at Antiam, and all the senators flocked
thither to wait for the event, Thrasea was forbidden to go there. The
Stoic philofiopher bore this insult with his usual calmness. Nero
afterwards indeed declared to Seneca that he was reconciled to
Thrasea, but this was probably no more than an expression of his fear.
The inflexible character of Thrasea, his refusal to take any part in the
degrading proceedings of tho senate, and the esteem which he enjoyed
among his contemporaries, increased the hatred of Nero, who only
waited for a favourable opportunity to get rid of him. It appears that
from the year 63 Thrasea never attended the meetings of the senate.
Three years thus passed away, when at length, in 66, his old
enemy Cossutianus brought forward a number of charges against
Thrasea, the substance of which was, that he took little or no part in
public affairs, and that when he did so, it was only to oppose the
measures of the government; that he was a secret enemy of the
emperor, and fulfilled neither his political duties as a senator nor
his religious duties as a priest. Thrasea first requested a personal
interview with tho emperor, which was refused. He then wrote to
him, asking for a statement of tho charges against him, and declaring
of which he had expected a confession of guilt and an humble petition
for pardon, he convoked the senate, to decide upon the charges against
Thrasea and others. Some of Thrasea's friends advised him to attend
the meeting, but most dissuaded him from it. One young and spirited
friend, Rusticus Arulenus, who was tribune of the people, offered to
put his veto upon the senatus-consultum, which however Thrasea pre-
vented. The philosopher now withdrew to his country-house. In the
senate, which was surrounded by armed bands, the quajstor of the
emperor read his oration, whereupon Cossutianus and othei-s began
their attacks upon Thrasea. The wishes of Nero, and the presence of
armed soldiers ready to enforce them, left the senators no choice, and
it was decreed that Thrasea, Soranus, and Servilia should choose their
mode of death, and that Helvidius, *he son-in-law of Thrasea, and
Paconius, should be banished from Italy. The accusers were muni-
ficently rewarded. Towards the evening of this day the quosstor of
the consul was sent to Thrasea, who had assembled around him a
numerous party of friends and philosophers; but before he arrived, a
friend, Domitius Caecilianus, came to inform him of the decree of the
senate, which spread consternation among all who were present.
Thrasea's wife Arria, who was a relative of Persius the poet (' Vita A,
Persii Flacci ') was on the point of making away with herself, but her
husband entreated her not to deprive her daughter of the last support
which now remained to her. When at length the qusstor arrived
and officially announced the decree, Thrasea took Helvidius and his
friend Demetrius to his bed-room, and had the veins of both his arma
opened; and when the blood gushed forth, he called out, "Jove, my
deliverer, accept this libation." (Tacitus, 'Annal.,' xvi. 21-35; Dion.
*Cass., Ixii. 26.)
Thus died Thrasea, according to the unanimous consent of the
ancients a man who professed the genuine and stem virtues of the
olden time in the midst of a degenerate age. Tacitus calls him virtue
itself, and even Nero is reported to have said, " I would that Thrasea
liked me as much as he is a just judge." (Plutarch, • Rei PublicaB
gerendae Praecepta,' p, 810, A. ed. Frankf. comp. Martial, i. 9;
Juvenal, v. 36 ; Plmy, ' Epist.,' viii. 22.) Tho principles which guided
him through life he had imbibed from the Stoic philosophy. Cato tho
Younger was his favourite character in the history of the Roman
republic; he wrote a Life of Cato, which Plutarch made use of in his
biography, and thus we probably still possess the substance of it.
(Plutarch, *Cato Min.,' 25 and 37; compai-e Heereu, 'De Fontibus
Plutarchi,' p. 1 68.) Rusticus Arulenus wrote a work on Thrasea and
Helvidius, in which he characterised them as men of tho purest inte-
grity — an expression which became fatal to the author. (Sueton.,
' Domit.,' 10; Tacitus, 'Agric.,' 2 and 45.)
THRASYBU'LUS (@pa(7v0ov\os}, the son of Lycus, was bom at
Steiria in Attica. In the year B.C. 411 the oligarchical party at Athena
gained the ascendancy, and formed a new senate of 400 members.
The oligarchs in tho fleet stationed at Samos, endeavoured to bring
about a similar revolution there, but their efforts failed ; and among
the men who exerted themselves to maintain the democratical consti-
tution, Thrasybulus, who then had the command of a trireme, was
foremost. He and his friend Thrasyllus compelled the oligarchs to
swear to keep quiet, and not to attempt any alteration in the constitu-
tion. The generals who were known to belong to the oligarchs were
removed, and Thrasybulus and Thrasyllus were appointed in their
stead. The army under their command assumed the rights and power
of the people of Athens, aud in an assembly of the camp Thrasybulus
got a decree passed, by which Alcibiades, wlio had lately been the
chief support of the democratical party, and who was living in exile
with Tissapheruos, should be recalled. Thrasybulus set out to fetch
him to the oamp. (Thucydides, viii. 8L) In s.c. 410 he greatly con-
29
THRASYBULUS.
THRASYBULUS,
W
tributed to the victory which the Athenians gained in the battle of
Cyzicus. In B.C. 408, when Alcibiades returned to Athena from
Byzantium, Thrasybulus was sent with a fleet of eighty galleys to the
coast of Thrace, where he restored the Athenian sovereignty in most
of the revolted towns ; and while he was engaged here he was elected
at Athens one of the generals, together with Alcibiades and Conon. In
B.C. 406 Thrasybulus was engaged as one of tho inferior officers in tlie
Athenian fleet during the battle of Arginusa} ; and after the battle he
and Theramenes wei-e commissioned by tho generals to save tho men
on tho wrecks; but a storm prevented their executing this order.
Respecting the fate of the generals and the conduct of Theramenes on
this occasion, see Theramenes. Thrasybulus is not charged with any
improper act during the proceedings against the generals, and for two
years after his name does not occur in the history of Attica.
During the government of the Thirty Tyrants at Athens, he was
sent into exile, and took refuge at Thebes, The calamities under
which hia country was suffering roused him to exertion. The spirit
which prevailed at Thebes against Sparta, and against its partisans at
Athens, emboldened him to undertake the deliverance of his country.
With a band of about seventy, or, according to others, of only thirty
fellow-exiles, he took possession of the ^fortress of Phyle, in the north
of Attica. The Thirty, sure of victory over so insignificant a garrison,
sent out the 3000 Athenians whom they had left in the enjoyment of
a kind of franchise, and the knights, the only part of the population
of Athens who were allowed to bear arms. On tbeir approach to
Phyle some of the younger men, eager to distinguish themselves, made
an assault upon the place, but were repelled with considerable loss.
The oligarchs then determined to reduce the fortress by blockade ; but
a heavy fall of snow compelled them to return to Athens. During
their retreat the exiles sallied forth, attacked the rear, and cut down
a great number of them. The Thirty now sent the greater part of
the Lacedaemonian garrison of Athens and two detachments of cavalry
to encamp at the distance of about fifteen stadia (nearly two miles)
from Phyle, for the purpose of keeping the exiles in check. The small
baud of Thrasybulus had in the meantime increased to 700, as the
Athenian exiles flocked to him from all parts. With this increased
force he one morning descended from Phyle, surprised the enemy, and
slew upwards of 120 hoplites and a few horsemen, and put the rest to
flight. Thx-asybulus erected a trophy, took all the arms and military
implements which he found in the enemy's camp, and returned to
Phyle.
The Thirty now began to be alarmed at the success of the exiles,
and thought it necessary to secure a place of refuge in case the exiles
should succeed in getting possession of Athens. For this purpose
they, or rather Critias, devised a most atrocious plan. By force and
fraud he contrived to secure 300 citizens of Eleusis and Salamia capable
of bearing arms ; and after they were conveyed to Athens he compelled
the 3000 and the knights to condemn them to death. All were accord-
ingly executed, and Eleusis was deprived of that part of its population
to which it might have looked for protection. In tlio meantime the
number of exiles at Phyle had continued to increase, and now
amounted to one thousand. With these Thrasybulus marched by
night to Piraeus, where he was joyfully i-eceived, and great numbers of
other exiles immediately increased his army. The Thirty no sooner
heard of this movement than they marched against Peirseus with all
their forces. Thrasybulus by a skilful mancEuvre obliged the enemy,
who was superior in numbers, to occupy an unfavourable position at
the foot of the hill of Munychia. In the ensuing battle the army of
the tyrants was put to flight and diiven back to the city. Critias fell
in the contest.
The consequences of this success showed that there had been little
unity among tho oligarchs, and that an open breach had only been
prevented by fear of Critias. Some of the Thirty and a great many of
the 3000 were in their hearts opposed to the atrocities which had been
committed, and had avoided, as much as they could, taking part in
the rapine and bloodshed. They also were aware that the hatred and
contempt under which they were labouring were owing mainly to the
violence of their colleagues j and for the purpose of maintaining their
own power they now resolved to sacrifice their colleagues. An assem-
bly was held, in which the Thirty were deposed, and a college of ten
men, one from each tribe, was appointed to conduct the government.
Two of these ten had formerly belonged to the Thirty, and the rest of
the Thirty withdrew to Eleusis. As regards the army of exiles under
Thrasybulus, the new government of Athens was no less determined
to put them down than the Thirty had been. Thrasybulus therefore
continued to strengthen himself, and to prepare for further operations.
for he engaged aliens in his service, and promised them, in case of their
success, the same immunities at Athens as those enjoyed by the citizens
(lo-oTeAeia). Arms, of which ho was still in want, were generally sup-
plied by the wealthy citizens of Peirseus and other places, and by the
ingenuity of his own men. As the danger from the exiles became at
last very imminent, the Ten of Athens applied to Sparta for assistance.
At the same time the faction at Eleusis also sent envoys to Sparta ;
but the government of Sparta refused to send an army for an under-
taking from which it could reap no advantages. However Lysander,
as harmostes, obtained leave to levy an army, and his brother Libys
and got together a numerous army. Being thu« enclosed by land and
by sea, Thrasybulus and bis army had no proHpect except to aurrender.
But their deliverance came from a quarter whence it could have
least been expected. The power and influence which Lysander bad
even of the ephors and kings, and they were now bent upon thwarting
hia plans. King Pausanias was accordingly sent out with an army to
Attica, avowedly to assist Lysander in hia operations, but in reality
for the purpoaa of preventing the accomplishment of hia designs. He
encamped near Piraoua, as if ho designed to besiege the place in con-
junction with Lysander. After several aham manoeuvres against tho
exiles, Pausaniaa gained a victory over them without following it up.
He now aent aecretly an embassy to them, requesting them to send a
deputation to him and the ophors; and he also suggested the langtiage
which the deputies ahould use. At the eame time he invited the
pacific party at Athena to meet and make a public declaration of their
sentiments. Hereupon a truce waa concluded with the exiles, and a
deputation of them, as well as of the pacific party at Athens, was
sent to Sparta to negociato a general settlement of affairs. A« soon as
the Ten of Athens heard of this, they also sent envoys to Sparta to
oppose the other embassy. But this attempt failed, and the ephors
appointed fifteen commissioners with full powers, in conjunction with
King Pausaniaa, to settle all the difierences between the parties in
Attica. In accordance with the wishes of the exiles and the peaceful
party of the city, the commissioners proclaimed a general amnesty,
from which none we'-e to be excluded except the Thirty, the Eleven,
and the Ten who had formed the government of I'eiraeus. Any one
who might not think it safe to return to Athena was permitted to take
up his residence at Eleusis. This clause is unintelligible, unless we
suppose that the Spartans still wished to see Eleusis in the hands of
a party which might check the reviving spirit of independence among
the Athenians. Sparta guaranteed the execution of the proclamation.
Pausaniaa withdrew his forces, and Thrasybulus at the head of the
exiles entered Athens in triumph, and marched up the Acropolis to
offer thanks to Athena : an assembly was then held, in which Thrasy-
bulus impressed upon all parties the necessity of stx-ictly observing
the conditions of the peace.
Eleusis was now the seat of the most violent of the oligarchical
party, and they still indulged some hope of i-ecovering what was lost.
They assembled a body of mercenaries to renew the civil war ; but
Athens sent out a strong force against them. Xenophon says that the
leaders of the Eleusinian party were drawn to a conference and then
put to death. This isolated statement is rather surprising, as in all
other respects the popular party showed the greatest moderation, and
immediately after the quelling of the Eleusinian rebelUon Thrasybulus
induced the Athenians to proclaim a second amnesty, from which no
one was to be excluded. This amnesty was faithfully observed. The
first step after the abolition of the oligarchy was the passing of a
decree which restored the democratic form of government.
Thi'asybulus acquired the eateem of his fellow-citizens by the
courage and perseverance which he had shown in the deliverance of
his country, and although for many years he does not come forth very
prominently in the history of Attica, he waa no less active in restoring
Athens to her former greatness than he had been in wresting her from
the hands of her enemies. His last military undertaking belongs to
the year B.C. 389, when the government of Athens placed a fleet of
40 galleys at his command, with which he was to support the demo-
cratieal party in the island of Rhodes. On his arrival there he found
that no protection was needed, and he sailed to the north part of the
JEigea,n. In Thrace he settled a dispute between two princes, and
gained them as allies for Athens. At Byzantium and Chalcedon alao
the influence of Athena was restored, and with it new sources of
revenue to the republic were opened. After this he Bailed to Mitylene,
the only town in the island of Lesbos in which the Spartan party had
not gained the ascendancy. Thrasybulus here fought a battle with
Therimaohus, the Spartan harmostes, who waa defeated and slain.
Several towns were now reduced, and after he had plundered the
lands of those who refused to submit to Athens, he prepared to sail
to Rhodes ; but before he lauded there he sailed along the southern
coast of Asia Minor to levy some contributions there. His fleet cast
anchor in the mouth of the river Eurymedon in Pamphylia, near
Aspendus. In consequence of some outrage committed by his soldiera
on land, the Aspendians were exasperated, and during the night they
surprised and killed Thrasybulus in his tent, B.c, 889.
(Thucydides, viii. ; Xenophon, Edlen., i. 1, 12; i. 6, 36; ii, 3, 42;
ii. 4, 2, &c. ; iv. 8, 25, &c. ; Diodorus Sic, xiv. 32, &c, ; 94 and 99 ;
C, Nepos, Thrasybulus; compare E. Ph. Hinrichs, J)e Theramenis,
Critice, et Thrasyhuli Rebus et Ingenio, 4to, Hamburg, 1820; Thirlwall ;
Grote.)
THRASYBU'LUS, of Collytus in Attica, was a contemporary of
Thrasybulus the delivei-er of Athens, from whom he is usually distin-
guished by the epithet of the Collytian. He waa one of the Athenian
exiles who joined hia namesake at Phyle, and afterwards at Peirajus.
(Demosthenes, in ' Timocrat.,' p. 742.) lu the war against Antalcidas
he commanded eight Athenian galleys, with which he was taken
prisoner by the Spartan admiral. (Xenophon, Hellen., v. 1, 26, &c. ;
compare iEschines, in Ctesiphont., p. 73, ed. Steph.)
THRASYBU'LUS, a tyrant of Syracuse. He was a son of Qelo,
81
THROCMORTON, SIR NICHOLAS.
THUCYDIDES.
32
and brother of Hicro tho Elder, who ruled over Syracuse till the year
B.C. 46G. Hiero was succeeded by his brother Tlirasybulus, who was
a bloodthirsty tyraut, and oppressed tbe people still more than Hiero :
great numbers of citizens were put to death and others sent into
exile, and their property filled the private coffers of the tyrant. In
order to protect himself against the exasperated citizens, he got
together a large force of mercoDiiries, and relying on this new support,
he carried his reckless cruelties so far that at last the Syracusans
determined to rid themselves of their tyrant. They choso leaders to
give them a military organisation, that they might bo enabled to resist
the mercenaries of Thrasybulus. The tyrant at first endeavoured to
stop the insurrection by persuasion, but this attempt failing, he drew
reinforcements from Catana and other places, and also engaged new
mercenaries. With this army, consisting of about 15,000 men, he
occupied that part of the city which was called Achradina, arid the
fortified island, and harassed by frequent sallies the citizens, who
fortified themselves in a quarter of their city called Ityce. The Syra-
cusans sent envoys to several Greek towns in the interior of Sicily,
BoUciting their aid. The request was readily complied with, and they
soon had an army and a fleet at their disposal. Thrasybulus attacked
them both by sea and land, but his fleet was compelled to sail back to
the islajid after the loss of several triremes, and his army was obliged
to retreat to Achi-adina. Seeing no possibility of maintaining himself,
he sent ambassadors to the Syracusans with offers of terms of peace,
which was granted on condition of his quitting Syracuse. Thrasy-
bulus submitted to these terms, after having scarcely reigned one year,
and weut to Locri in Southern Italy, in B.C. 466, in exile. After the
Syracusans had thus delivered themselves of the tyrant, they granted
to his mercenaries free departure, and also assisted other Greek towns
in Sicily in recovering their freedom, (Diodorus Sic, xi. 67 and 68.)
THROCMOllTON, SIR NICHOLAS, was descended from an
ancient family in Warwickshire, and his ancestors had been employed
in the higher oflfices of state for some centuries. His father. Sir
George Throcmorton, had been in favour with Henry VIII., but being
a zealous papist, he incurred the king's displeasure by refusing to take
the oath of supremacy, and about 1538 was imprisoned in the Tower
of London, where he remained several years.
Nicholas, who was Sir George's fourth son, was bom about the year
1513. Having been appointed page to the Duke of Richmond, the
king's natural son, he accompanied his master to France, and remained
in his service till the duke's death in 1536. Sir George Throcmorton
was released from the Tower in 1543. His son Nicholas was then
appointed sewer to the king. In 1544 he headed a troop in the arma-
ment against France which Henry VIII. commanded in person ; he
assisted at the siege of Boulogne, and after his return received a
pension from the king as a reward for his services. After the king's
death he attached himself to the queen-dowager Catherine Parr, and
to the Princess Elizabeth. In 1547 he distinguished himself in the
campaign in Scotland under the Protector Somerset ; he was present
at the battle of Pinkey (or Musselburgh), and Somerset sent him to
London with the news of the victory. He was soon afterwards created
a knight, appointed to a place in the privy-chamber, and admitted to
great intimacy with Edward VI. The king bestowed iipon him some
valuable manors, and made him under-treasurer of the Mint. He sat
in parliament during Edward's reign as member for Northampton.
A short time before the king's death, Sir Nicholas married the
daughter of Sir Nicholas Carew, and on taking his wife to visit his
father at Goughton in Warwickshire, he was received with coldness by
the old knight ; partly perhaps on account of his Protestant principles,
but chiefly because he had been knighted before his eldest brother.
To remove this cause of offence, he took his brother back with him to
court, and, at the request of Sir Nicholas, the king raised him to the
dignity of a knight.
Sir Nicholas Throcmorton was present when Edward VI. died at
Greenwich in 1553. He was aware of the designs of the partisans of
Lady Jane Grey, but, though a Protestant, he was too much attached
to law and legitimacy to give any sanction to them. He therefore came
immediately to London, and despatched Mary's goldsmith to announce
to her the king's demise. On the 2nd of February 1554, Sir Nicholas
Throcmorton was arrested and committed to the Tower on a charge
of being concerned in the rebellion of Sir Thomas Wyatt. On the
17th of April he was brought to trial at Guildhall, London. This
trial is the most important and interesting event in his life. It is
certain that he was acquainted with Wyatt's intentions, and there is
little doubt that he was to some extent implicated in the rebellion.
He was tried before commissioners, some of whom were bitterly inimi-
cal to him, and who seemed to regard his triul as merely a form ueoes-
sary to be gone through previous to his execution. Sir Nicholas how-
ever conducted his own defence; and this he did with such ailmirable
mixed with retorts spirited, fearless, and reiterated, in answer to the
partial remarks of the lord chief justice and other commissioners, and
followed up by an impassioned earnestness of appeal to the jury, that,
in defiance of the threats of the chief justice and the attorney-general,
he obtained a verdict of acquittal. Sir Nicholas was directed to be
discharged, but was remanded, and kept in prison till the 18th of
January 1555. The jury were made to suffer ssverely for their inde-
pendent verdict. Two were fined 2000t each, six were fined 1000
mai'ks each, and four, who expressed contntion, were not fined. All
were remanded to prison, where they remained till the 12th of Decem-
ber, when five were discharged on payment of the reduced fine of 220^,
each, three on payment of 601. each, and four without fine.
Sir Nicholas Throcmorton, after his release, avoided the approaching
storm of persecution by going to France, where he remained till 1556.
Though he afterwards served in Queen Mary's army under the Earl of
Pembroke, he devoted himself chiefly to the Princess Elizabeth, whom
he visited privately at Hatfield. When Queen Mary died, he was
admitted to see her corpse, and, as Elizabeth had requested, took from
her finger the wedding-ring which had been given to her by Philip,
and delivered it to Elizabeth. Elizabeth gave him the office of chief
butler of England, a situation of some dignity, but inconsiderable
emolument, and afterwards made him chamberlain of the exchequer.
In 1559 he was sent on an embassy to France, and remained at the
French court as resident ambassador till the beginning of 1563. Dr.
Forbes has published the greater part of Tiirocmorton's correspondence
with his own government while he was in this confidential situation.
It displays great diplomatic skill and management, but perhaps rather
too much tendency to intrigue ; and he supported the cautious and
somewhat doubtful policy of Cecil with zeal and discretion. Indeed
he was on the most confidential terms with Cecil during the whole of
this period, but after his return a coolness arose between the two
statesmen, which increased till it became a strong personal animosity.
In 1565 Throcmorton was sent on a special embassy to Scotland, to
remonstrate with Mary Queen of Scots against her intended marriage
with Darnley ; and when Mary was imprisoned at Lochleven in 1567,
Throcmorton was commissioned by Elizabeth to uegociate with the
rebel lords for her release.
In 1569 Throcmorton was sent to the Tower on a charge, which
indeed appears to have been well founded, of having been engaged in
the intrigue for a marriage between Mary Queen of Scots and the
Duke of Norfolk. Though he was not kept long in confinement, he
never afterwards regained the confidence of Elizabeth, and the distress
of mind occasioned by the loss of her favour has been thought to have
hastened his death, which took place at the house of the Earl of
Leicester, February 12, 1571, in his fifty-eighth year.
Sir Francis Walsingham, in a letter to the Earl of Leicester on tlie
occasion of Throcmorton's death, says of him that " for counsel in
peace and for conduct in war he hath not left of like sufi&ciency that
I know." Camden says he was '•' a man of large experience, piercing
judgment, and singular prudence ; but he died very luckily for himself
and his family, his life and estate being in great danger by reason of
his turbulent spirit."
THUA'NUS, J. A. [Tnou, De.]
THUCY'DIDES (0ou/cu5t5r?s), the son of Olorus, or Orolus, and
Hegesipyle, was a native of the deraus of Alimus in Attica. He was
connected by his mother's side with tlie family of the great Miltiades,
and the name of his father was a common one among the Thracian
princes. If he was forty years old at the commencement of the Pelo-
ponnesian war, according to the statement of Pamphila (Gellius, xv.
23), he was born in B.C. 471. In his own work he nowhere mentions
his age or the time of his birth, but he says that he lived through the
whole of the Peloponnesian war, and that he was of the proper age
for observing its progress (v. 26).
Our principal information respecting the life of Thucydides is a
biography of him written by Marcellinus, which is however full of
contradictions and doubtful stories. There is also an anonymous
biography of him prefixed to many editions of his works, which is
still worse than that of Marcellinus. Thucydides mentions inci-
dentally a few facts concerning himself, which is almost all that we
know with ceitainty about his life.
There is a well-known story that when a boy he heard Herodotus
i-ead his History at Olympia, and was so much moved that he burst
into tears. But there is good reason for believing that this recitation
of the History of Herodotus never took place at the Olympic games
[Herodotus] ; and if there is any foundation for the story of Thucy-
dides having heard him read it, we would rather refer it to a later
recitation at Athens, which is mentioned by Plutarch and Eusebius.
Suidas is the only writer who says that Thucydides heard Herodotus
at Olympia; Marcellinus and Photius relate the same tale without
mentioning where the recitation took place.
There seems nothing improbable in the accounts of the ancient
biographers that Thucydides was taught philosophy by Anaxagoras
and rhetoric by Antiphon ; but their statement that he accompanied
the Athenian colony to Thurii is probably a mistake arising from their
confounding him with Herodotus, who, we know, was of the colonists.
But whether he went to Thurii or not, it it certain that he was in
Athens in the second year of the Peloponnesian war, B.C. 430, when
ho was one of those who had the plague. (Thucyd., ii. 48.) In the
eighth year of the war, B.C. 424, he was in command of an Athenian
fleet of seven ships, which lay off Thasos. Brasidas, the Lacedaemo-
nian commander, made an attempt to obtain possession of Amphipolis
on the Strymon, which then belonged to Athens ; and Thucydides, aa
soon as he heard of it, sailed to protect Amphipolis, but was only in
sufficient time to save Eion, a seaport at the mouth of the Strymon.
Amphipolis had fallen before he could arrive there, (Thucyd., iv.
102, &c.) For this he was either condemned to death or banished by
33
THUCYDIDES.
THULDEN, THEODOR VAN.
34
the Athenians in the year following, B.C. 423 ; and in consequence of
the sentence passed upon him be spent twenty years in exile, namely,
till B.C. 403. (Thucyd., v. 2G.) This year coincides exactly with the
restoration of the democracy by Thrasybulus, when a general amnesty
was granted, of which Thucydidea seems to have availed himself.
Where ho passed tho time of his exile is not mentioned by himself.
Maroellinus says that he first went to ^giua, and afterwards to Scapte-
Hyle in Tlirace, opposite the island of Tliasos, where he had some
valuable gold-mines. (Compare Plutarch, ' De Exilio,' p. 605.) It
appears however not improbable that he visited several places during
Jiis exile : the intimate knowledge which he shows respecting the
history of the Italiotes and Sicoliotes almost inclines one to suppose
that he may have visited Italy and Sicily after the failure of the
Athenian expedition in the latter island. His property in Thrace
would however naturally lead him to pass the greater part of his time
in that country. This property, which was very considerable (Thucyd.,
iv. 105), was probably derived from his family, which came from
Thrace, though Marcellinus says that he obtained it by marrying a
Thracian heiress.
How long he lived after his return from exile, and whether he
continued at Athens till the time of his death, is quite uncertain.
According fo some accounts he was assassinated at Athens, according
to others he died at Thasos, and his bones were carried to Athens.
He is said to have been buried in the sepulchre of the family of
The Peloponnesian war forms the subject of the History of Thucy-
dides. He tells us that he foresaw it would be the most importaut
war that Greece had ever known, and that he therefore began collect-
ing materials for its history from its very commencement; that,
where he had to rely upon the testimony of others, he carefully
weighed and examined the statements that were made to him ; and that
he spared neither time nor trouble to arrive at the truth, and that in
consequence of his exile he was enabled to obtain information from
the Peloponnesians as well as his own countrymen (i. 22 ; v. 26).
Though he was engaged in collecting materials during the whole of
the war, he does not appear to have reduced them into the form of a
regular history till after his return from exile, since he alludes in
many parts of it to the conclusion of the war (i. 13 ; v. 26, &c.). He
did not however live to complete it : the eighth book ends abruptly
in the middle of the year B.C. 411, seven years before the termination
of the war. Eveu the eighth book itself does not seem to have
received the last revision of the author, although there is no reason at
all for doubting its genuineness, as it bears on every page indubitable
traces of his style and mode of thought. Some ancient writers how-
ever attributed it to his daughter, others to Theopompus or Xenophon.
As the work of Thucydides is evidently incomplete, it would appear
that it was not published in his lifetime; and there is therefore great
probability that the statement is correct which attributes the publica-
tion of it to Xenophon. ZSTiebuhr has brought forward reasons which
Beem to render it almost certain that Xenophon's ' Hellenics ' consist
of two distinct works, and that the last five books were not pviblished
till long after the first two. The first two, which seem to have borne
the title of the ' Paralipomena ' of Thucydides, complete the history
Xenophon, together with the eight books of Thucydides. (Niebuhr,
in ' Philological Museum,' i. 485, &c.)
The first book of Thucydides is a kind of introduction to the
history. He commences by observing that the Peloponnesian war
was more important than any that had been known before ; and to
prove this, he reviews the state of Greece from the earliest times
down to the commencement of the war (c. 1-21). He then proceeds
to investigate the causes which led to it, of which the real one was
tho jealousy which the Peloponnesians entertained of the power of
Athens ; and interrupts his narrative to give an account of the rise
and progress of the Athenian empire down to the commencement of
the war (c. 89-118). He had an additional reason for making this
digression, since this history had either been passed over by previous
writers altogether, or had been treated briefly, without attention to
chronology (c. 97). He resumes the thread of his narrative at c. 119,
with the ne^ociations of the Peloponnesian confederacy previous to
the declaration of the war ; but the demand of the Lacedaemonians,
that the Athenians should drive out the accused, which was answered
by the Athenians requiring the Lacedaemonians to do the same, leads
to another digression respecting the treason and death of Pausanias '
(c. 128-134); and as proofs were found implicating Themistocles
in the designs of the Spartan king, he continues the digression
in order to give an account of the exile and death of Themistocles (c.
135-138). He then resumes the narrative, and concludes the book
with the speech of Pericles which induced the Athenians to refuse
compliance with the demands of the Peloponnesians. The history of
the war does not therefore begin till the second book ; but it would
be out of place to give here an abstract of the remainder of the
work.
Thucydides had formed a high opinion of the value and importance
of the work he had undertaken. It was not his object to afford
amusement, like former writers, but to give such a faithful representa-
tion of the past as would serve as a guide for the future (i. 22), His
observation of human character was profound; he penetrates with
■ BIOQ. DIV. VOL. VI.
extraordinary clearsightedness into the motivet and policy of the
leading actors of the war ; and he draws from the events ho reUtes
those lessons of political wisdom which have always made his work a
favourite study with thoughtful men of all countries.
He claims for himself the merit of the strictest accuracy, and it i%
impossible to read his History without being convinced of the trust-
worthiness of his statements. Hia impartiality also is conspicuous :
although he had been banished from his native city, he does not, like
Xenophon, turn renegade, and try to misrepreeent the conduct and
motives of hia own countrymen. Although a contemporary, and one
who had taken an active part in public affiiirs, he writes as free from
prejudice and party-feeling as if he hud lived at a time long sub-
sequent to the events ho narrates.
His History is constructed on entirely different principles from
those of his predeceesora. He confines himself strictly to his subject,
and seldom makes any digressions. He feels deeply the importance of
his work, and constantly strives to impress the same feeling upon his
readers. He had proposed to himself a noble subject, and wntes with
the consciousness of the value of hia labours, and the presentiment
that his work will be read in all future ages. There is consequently a
moral elevation in his style and mode of treating a subject, which Li
scarcely to be found in any other writer except Tacituf.
In narrating the events of the war, Thucydides pays particular
attention to chronology. He divides each year into two portions, the
summer and the winter, and is careful to relate under each the events
that took place respectively during that time. The speeches which he
introduces are not mei 3 inventions of his own, but contain the general
sense of what the speakers actually delivered, although the style and
the aiTangement are his (i. 22).
The style of Thucydides is marked by great strength, and energy.
Not only his expressions, but even single words seem to have been
well weighed before they were used ; each has its proper force and
significance, and none are used merely for the sake of ornament and
effect. The style is not easy, and it is probable that Thucydides never
intended it should be so, even to his own countrymen : his work was
not to be read without thought. Still his style is open to serious
objections. He does not sufficiently consult perspicuity, which is the
first virtue in all writing. His sentences too are frequently unneces-
sarily long, and the constructions harsh and involved. These remarks
are more especially applicable to the speeches inserted in the History,
which Cicero found as difficult as we do. (' Orator.,' 9.)
The Greek text was first published by Aldus, Venice, 1502, and the
scholia in the following year. The first Latin translation, which was
made by Laurentius Valla, appeared at Paris in fol., 1513. The first
Greek and Latin edition was that of Henry Stephens, the Latin being
the translation of Valla, with corrections by Stephens, fol. 1564.
Among the modern editions, those most worthy of notice are Bekker's,
3 vols., 8vo, Berlin, 1821 ; Poppo's, which contains two volumes of pro-
legomena, with the scholia and numerous notes, 1 1 vols. 8vo., Leipzig,
1821-1840 ; Haack's, with selections from the Greek "scholia and
short notes, which the student will find very useful, 2 vols. 8vo,
Leipzig, 1820, reprinted in London, in 3 vols. 8vo, 1823; GoUer's,
2 vols. 8vo, Leipzig, 1836, 2nd edition, reprinted in London ; Arnold's,
3 vols. 8vo, Oxford, 1st edition, 1830-1835; and Haase's, Paris, 1845.
There are translations of Thucydides into most of the modern
European languages. In English the first translation was made by
Thomas Nicolls, from the French version of Seysel, and was
published in London, fol., 1550. This was succeeded by the transla-
tions of Hobbes and William Smith, which have been frequently
reprinted. The most recent are by S. T. Bloomfield, 3 vols. Svo,
London, 1829, and by Dale, published in Bohn's * Classical Library.'
A recent translation in German is by Klein, 8vo, Miinchen, 1826 :
and in French one of the best is said to be by Gail.
Respecting the life of Thucydides, the reader may consult Dod-
well, ' Annales Thucydidei et Xenophonteii,' &c., 4to, Oxford, 1702 ;
and Kruger, ' Untersuchungen iiber das Leben dea Thucydides/
Berlin, 1832.
THULDEN, THEODOR VAN, born at Bois-le-Duc in 1607, was
one of the most distinguished scholars and assistants of Rubens, with
whom he was also a favourite. He was with Rubens in Paris, and is
raid to have executed the greater part of the celebrated series of the
so-called Gallery of the Luxembourg, painted in honour of Mary de'
Medici. Van Thulden is distinguished both as a painter and as an
etcher. As a painter he excelled in various styles. There are several
large pictures, both historical and allegorical, by him, dispersed over
Germany and the Netherlands; he painted also small pictures from
common life in the manner of Teniers, such as markets, fairs, and the
like ; and he was frequently employed by architectural and landscape
painters to embellish their pictures with small appropriate figures, in
which he was excellent; he painted many such in the pictures of
Neefs and Steenwyck. , , t.\ l e
Van Thulden's style in his greater works is altogether that ot
Rubens, and, although inferior in boldness of design and colouring, his
works may easily be mistaken for those of Rubens; the ' Martyrdom
of St. Andrew,' in St-^Michael's church at Ghent, was long thought to
be a work of Rubens. In chiar'oscuro. Van Thulden was nearly if not
quite equal to his master. A ' St. Sebastian,' in the churchy ot tne
Bernardines at Mechlin, and an ' Assumption of the Virgin, m tne
D
S6
TUUMMEL, MORITZ AUGUST VON.
THUNBERQ, CARL FETTER.
S«
church of the Jesuits at Bi-uges, were confiidered two of his beet altar-
piecfS. While at Paris he painted twenty-four pictures of the Life of
St. John of Hatha in the church of the Mathurius, which he himself
etched on copper in 1633 ; the pictures have since been painted over.
Van Thulden's etchings are numerous, and in a masterly style : he
piibliiihed a set of fifty-eight plates from the paintings of Nicol6
Abati at Fontainebleau, after the designs of Priinaticcio, which are
greatly valued, for as the paintings were destroyed in 1738, they arc
all that remaius of the original designs. They have been copied
seveial times : the original set appeared under the following title :
' LesTravaux d'Ulysse, dosseignez par le Sieur de Saiuct-Martin, do la
fayon qu'ils se voyent dans la liaison lloyale de Fontainebleau, peint
par lo Sieur Nicolas, et gravds au cuivre par Theodore van Thulden,
avec lo Buject et I'explication morale de chaque figure.' He etched
also forty-two plates after Rubens, of the entrance of Ferdinand the
Cardinal-Infant into Antwerp : 'Pompa introitus Ferdinandi,' &c. The
eight plates of the Hbtory of the Prodigal Son, to which he put
Rubens' name, are considered to be from his own designs ; they are
entitled, ' De verlooren Soon, door P. P. Rubens. Th. Van Thulden
fee' Van Thulden died in his native place, Bois-le-Duc, in 1676.
THOmMEL, MORITZ AUGUST VON, a German writer who was
greatly admired by his contemporaries, and who still continues to hold
a high literary rank with his own countrymen. He was born at
Schonfeld, near Leipzig, May 27th 1738, where his father possessed
considerable property, but lost much of it by the plundering of the
Prussian troops in Saxony, 1745. Moritz, who was the second son of
a family of nineteen, was sent to the university of Leipzig in 1756.
There he found in Qellert not only an instructor, but a friend ; and
he also formed an acquaintance with Weisse, Rabener, von Kleist, &c.,
and, among others, with au old advocate named Balz, who at his
death, in 1776, left him the whole of his fortune, 24,000 dollars. This
accession of wealth enabled Moritz to give up the places he held under
Duke Ernest of Saxe-Coburg. first as Kammer-junker, and, from 1768,
as privy councillor and minister, and to retire in 1783 to Sonneborn,
an estate of his wife, at which place and at Qotha he continued chiefly
to reside until his death, which happened while he was on a visit at
Coburg, October 26th 1817. Thiimmel's literary reputation was
established by his ' Wilhelmine,' a ' comic poem in prose,' first pub-
lished in 1764. This short production, for it is in only five cantos or
chapters, was received as something altogether new in German litera-
ture, and as a masterpiece of polished humour and playful satire. It
was translated not only into Freuch, but Dutch, Italian, and Russian;
and it has been reprinted entire in Wolff's ' Encyclopiidie ' (1842).
His poetical tale, ' Die Inoculation der Liebe,' 1771, and other pieces
in verse, did not add much to his fame ; but his last and longest work
• Reise in den Mittaglichen Provinzen von Frankreich ' (Travels in the
Southei-n Provinces of France), in 9 vols., 1799-1805, is also his literary
chef-d'oeuvre. Instead of being, as its title would import, the mere
record of his tours in that country, it is, like Sterne's ' Sentimental
Journey,' to a great extent, a work of fiction, interspersed with frag-
ments in verse, which breathe more of poetry than his other produc-
tions of that kind. It abounds with satiric humour and pleasantry,
with witty and shrewd observations, and shows the author to have been
an accomplished man of the world, intimately acquainted with human
nature. That it is a work of no ordinary merit and pretension may
be supposed from the notice it has obtained from Schiller, in his essay
'Ueber Naive und Sentimentalvsche Dichtung;' who, if he praises it
with greater reserve than other critics, admits that, as a work of
amusement, it is one of a superior kind, and will as such continue to
enjoy the character it has obteined. A portrait of Thiimmel, after
Oeser, is prefixed to the 6th volume of the ' Neue Bibliothek der
Schonen Wissenschaften,' a complete edition of his works, in six
volumes.
THUNBERG, CARL PETTER, an eminent Swedish traveller and
botanist, and professor of natural history in the University of Upsal,
was born on the 11th of November 1743, at Jonkoping in Sweden,
where his father was a clergyman. He was early sent to the Univer-
sity of Upsal for the purpose of studying medQcine, and became a
pupil of the great Linnajus, Under his instruction he acquired that
taste for natural history which so remarkably distinguished the school
of Linnaeus, and which has given to the world so many famous natu-
ralists. Having completed his course of study, he graduated in 1770,
and was honoured by having bestowed upon him the Kohrean
pension for the space of three years. Although the sum was small,
about fifteen pounds per annum, he determined to use it for the pur-
poses of improvement, and accordingly left Upsal for the purpose of
visiting Paris and the universities of Holland. Whilst in Amsterdam
he became acquainted with the botanists and florists of that city, and
they suggested to him the desirableness of some person visiting Japan
for the purpose of exploring its vegetable treasures. Thunberg imme-
diately oSered his services, and a situation as surgeon to one of the
Dutch East India Company's vessels having been obtained for him, he
left Amsterdam for Japan in the year 1771. He landed at the Cape
of Good Hope for the purpose of learning amongst the Dutch settlers
there the Dutch language, which is the only European language
spoken extensively in Japan, and also in the hope of adding to his
knowledge of natural objects by researches in Africa. Here he made
several excursions into the interior, visiting various of the native tribes.
and after having remained three winters at the Cape, where he col-
lected much valuable information, he set sail in 1773 for Java and the
Japan Isles. He remained in these islands five years, n;aking large
collections of the plants of these countries, as well as observations on
the habits, manners, and language of their inhabitants. His ability to
labour however during his residence both in Africa and Asia, was
very much diminished by a frightful accident which he met with on
first leaving Holland. The keeper of the stores in the ship, having
flour and used for making pancakes, of which the whole crew partook.
All were ill, and many suffered severely at the time, but none was so
bad as Thunberg ; he only gradually recovered his health, and through
his long life always laboured under the debility and derangement his
1779, making first a short stay in England. Here he formed the
acquaintance of Sir Joseph Banks, Dryander, and Solander, and
availed himself of the extensive collection of plants from all parts of
the world, and valuable library of Sir Joseph, for the purpose of
made demonstrator of botany at Up-sal in 1777, and in 1784 was
installed in the chair of the great Linnaeus as professor of botany.
In 1785 he was made a knight of the order of Waea, and in 1815
commander of the same order.
On gaining his home, Thunberg immediately commenced arranging
the vast mass of materials he had collected in his travels for the pur-
pose of publication. His first important work was a description of
the Japanese plants, which was published at Leipzig in 1784, with
the title 'Flora Japonica, sistens Plantas Insularum Japonic;irum,
secundum Sjstema Sexuale emendatum,' 8vo, and illustrated with
thirty-nine engravings. In this work a great number of new plants
were described and arranged according to the Linnaoan system, in
which he ventured to dispense with the three classes called Monoecia,
DioQcia, and Polygamia. He subsequently published some botanical
observations on this ' Flora,' in the second volume of the ' Transac-
tions ' of the Linnaean Society.
In 1788 he commenced the publication of an account of his travels,
under the title, 'Resa uti Europa, Africa, Asia, forattad aren 1770-79,'
8vo, Upsal. This work was completed in four volumes, and contains
a full account of his eventful life, from the time he started from Upsal
with his Kohrean pension, till he returned to the same place laden
with treasures from a hitherto unexplored region. In these volumes
he has taken great pains to collect all possible information on the
medicinal and dietetic properties of plants in the countries he visited,
as well as their uses in rural and domestic economy. He recommends
several new plants for cultivation in Europe as substitutes for those
in present use. This work also gives a simple and pleasing account of
the original natives of the places in which he sojourned, as well as of
the European settlers. It has been translated into German by Gros-
kund, and published at Berlin in 1792. It appeared in English at
London in 1793, and in French at Paris in 1796.
His next work was a 'Prodromus Plantarum Capensium, Annis
1772-75 collectarum,' Upsalise, 1794-1800 : being an account of the
plants he had collected at the Cape. From 1794 to 1805 he pub-
lished in folio, under the title ' Icones Plantarum Japouicarum,'
Upsalise, a series of plates illustrative of the botany of the Japan
Isles. "These were followed by the ' Flora Capensis,' 8vo, Upsalite,
1807-13. In this work the most complete view of the botany of the
Cape of Good Hope is given that has hitherto been published. In
1807, in conjunction with Billberg, he published the 'Plantarum
Brasiliensium Decas Prima,' 4to, Upsalise. In this work the plants
collected by Freireiss and Sauerlandcr, in the province of Minas
Geraes in Brazil, are described; but the subsequent parts were
Besides the above works, on which the reputation of Thunberg as a
traveller and a botanist mainly rests, he was the author of almost
countless memoirs and academical dissertations. The subjects of
these were chiefly those which his long residence in Africa and Asia
afforded. The majority of them are upon botanical topics; not a few
however are devoted to a consideration of zoological subjects.
Although botany was his primary object in his travels, he yet lost
no opportunity of obtaining a knowledge of the new animals he met
with, and several of his papers are descriptions of these. He pub-
lished several memoirs in the Londou 'Philosophical Transactions,'
and the 'Transactions' of the Linnaoan Society, also in the Trans-
actions of Russian, German, French, and Dutch scientific societies and
journals, and a much greater number in those of Sweden. The aca-
demical dissertations bearing his name, and presented at the University
of Upsal, are nearly 100 in number, and were published between the
years 1789 and 1813.
Thunberg was elected an honorary member of sixty-six learned
societies. Ho died at the advanced age of eighty-five, on the 8th of
August 1828.
Retzius named a genus of plants in the natural order A canthacece,
in honour of him, Thunbergia. The following genera of plants have
species named after him : — Ixia, Isolepis, Cyperus, Jmperata, SpataUa,
Convolvidus, Campanula, Gardenia, Atriplex, Ilydrocotyle, Jihus, Cras-
I' sula, Bcrberis, Erica, Passerina, Thalictrum, Cocculiis, Equisetum,
Hypnvm, Fiisidens, Cystoseira, QyaUcta, and Endocarpon. Of insects,
37
THURLOE, JOHN.
THURLOE, JOHK.
the genera Harpalus, Lygceue, Pyralia, and Tinea have specific oanieB
after Thunberg.
Thunberg was an amiable kind man, and highly esteemed by his
friends and pupils. The great additions that he has made to our
knowledge of the plants of the world, as well as their uses to man,
place him amongst the most distinguished botanists of the last and
present century. He was not great as a vegetable physiologist, nor
did he attempt anything more in systematic botany than a slight emen-
dation of the system of Linnaeus. As a traveller, Thunberg is remark-
able for the accuracy of bis observations on the manners, habits, and
domestic economy of the people that he visited.
THURLOE, JOHN, who held the office of secretary of state during
the Commonwealth, was born in 1616, at Abbots Roding, in Essex, of
which place his father, the Rev. Thomas Thurloe, was rector. He was
designed for the profession of the law. Through the interest of Oliver
St. John, who was his patron through life, he was appointed, in 1645,
one of the secretaries to the parliament commissioners for conducting
the treaty of Uxbridge. He was called to the bar after this, in 1647,
by the society of Lincoln's Inn; and in March 1648 he received the
appointment of receiver or clerk of the cursitor's fines, "worth at
least 350/. per annum," says Whitelocke ; " and in this place was Mr.
Thurloe servant to Mr. Solicitor St. John." (' Memorials,' p. 296.)
Thurloe has left behind him a distinct denial of knowledge of or
participation in King Charles's death, which took place, as is well
known, in January 1649. Writinp: to Sir Harbottle Grimston for the
counsellor on that and on other occasions, and "that I was the medium
or hand between them by which their counsels were communicated to
each other," he says, " I was altogether a stranger to that fact and to
all the counsels about it, having not had the least communication with
any person whatsoever therein." (Thurloe's * State Papers,' vol. vii.,
p. 914.) It was very unlikely that a person in Thurloe's subordinate
position at that time should have been consulted ; and if it were a
question of any importance whether he approved of the king's death
or not, his subsequent continual identification with the authors of that
event is more than sufficient to fix him with responsibility.
On the 11th of February 1650 Thurloe was appointed one of the
officers of the treasury of the company of undertakers for draining
Bedford Level, a new efibrt to drain this tract of country having been
set on foot the year before. In a letter from St. John to Thurloe,
dated April 13, 1652 (' State Papers,' vol. i., p. 205), which is interest-
ing as showing the terms on which Thurloe and St. John were, we find
that Thurloe was then on an official tour of inspection : " Now you
are upon the place, it would be well to see all the works on the north
of Bedford river to be begun. Pray by the next let me know whether
Bedford river be finished as to the bottoming." In the same letter
are directions from St. John, now loi'dchief-justice, for the purchase
of a place for him in the neighbourhood of London, from which it
would appear that Thurloe was in the habit of managing St. John's
private affairs for him. The same letter contains St. John's congratu-
lations to Thurloe on his appointment as seci'etary to the council of
state, which appointment had just taken place : " I hear from Sir
Hen. Vayne, and otherwise, of your election into Mr. PVost's place,
with the circumstances. God forbid I should in the least repine at
any of his works of Providence, much more at those relating to your
own good, and the good of many. No, I bless him. As soon as I
heard the news, in what concerned you, I rejoiced in it upon those
grounds. No, go on and prosper : let not your hands faint : wait
upon Him in his ways, and He that hath called you will cause his
presence and blessing to go along with you." In the course of the
previous year, 1651, Thurloe had been to the Hague, as secretary
to St. John and Strickland, ambassadors to the states of the United
Provinces.
When Cromwell assumed the Protectorship, in December 1653,
Thurloe was appointed his secretary of state. In consequence of his
attaining to this distinction, he was, in the February succeeding,
elected a bencher of the society of Lincoln's Inn. Thurloe was
elected member for the Isle of Ely in Cromwell's second parliament,
called in June 1054, and framed on the model prescribed by the
Instrument of Government. He was re-elected for the Isle of Ely in
the next parliament, called in September 1656. Cromwell obtained
from this parliament an act settling the office of post of letters, both
inland and foreign, in the state for ever, and granting power to the
Protector to let it for eleven years at such rent as he should jufige
reasonable ; and it was let by him to Thurloe, at a rent of 4000Z.
a year, as we learn from a memorandum drawn up by him when the
Rump Parliament had cancelled the grant. ('State Paper?,' vol. vii.,
p. 788.) It is to be inferred that he made much profit by this farming
of the postage. The salary of his secretaryship of state was 800/.
a year. He is described in a 'Narrative of the Late Parliament,'
reprinted in the 'Harleian Miscellany' (vol. iii., p. 453), as "secretary
of state and chief postmaster of England, places of a vast income."
There is the following entry in VVhitelocke's 'Memorials,' under
the date of April 9, 1657:— "A plot discovered by the vigilancy of
Thurloe, of an intended insurrection by Major-Qeneral Harrison and
many of the Fifth-Monarchy Men" (p. 655). Thurloe afterwards, by
Cromwell's desire, reported on the subject of this plot to the parlia-
jnent, and received in his place the thankis of the house, through the
speaker, for his detection of the plot, and " for the great services done
by him to the commonwealth and to the parliament, boUi ia this and
many other particulars." On the 13th of July 1657 he was twoni one
of the privy council to the Protector, appointed in accordaoce with
the ' Humble Petition and Advice.' Honours now came thick upon
him. In the year 1658 he was elected one of the governors of the
Charter-House and chancellor of the University of Glasgow.
In September 1658 Cromwell died, and his son Richard was pro*
claimed in his stead. In the parliament that was called in December,
Thurloe was solicited to sit for Tewkabury, in a letter which u worth
extracting, as showing liis estimation and position at tiiis time, and the
spirit of constituencies : — " Noble Sir, We undei^tand that you are
pleased bo much to honour this poor corporation as to accept of our
free and unanimous electing you one of our burgesses in the next
parliament, and to sit a member for this place. Sir, we are so sensible
of the greatness of the obligation, that we know not by what expres-
sions sufficiently to demonstrate our acknowledgements ; only at
present we beseech you to accept of this for an earnest, that whom-
soever you shall think worthy to be your partner shall have tho
second election; and our zeal and hearty affections to serve and
honour you whilst we are, as we shall ever strive to be, Sir, your
most humble and obliged servants," &c. : signed by the bailifiCj and
justices of Tewksbury. ('State Papers,' vol. vii., p. 572.) He was
not after all chosen for Tewksbury. He was elected for Wisbech,
Huntingdon, and the University of Cambridge. His election for the
last was communicatt d to him in a letter from the celebrated Dr.
Cudworth, who wrote to him in this strain : — " We being all very glad
that there was a person of so mnch worth and so good a friend to the
university and learning as yourself, whom we might betrust with the
care of our privileges and concernments." (' State Papers,' vol. vii.,
p. 587) Thurloe made his election to sit for the University of
Cambridge.
The meeting of this parliament was the beginning of discontents
and of Richard Cromwell's fall. We find Thurloe, in a letter to
Henry Cromwell, viewing the complaints of the army and of tho
opposition in parliament as pointed principally against himself, and
stating that he had asked the Protector's permission to retire from his
office. " I trust," he adds, " other honest men will have their oppor-
tunity, and may do the same thing with myaelf with better acceptance,
having not been engaged in many particulars, as I have, in your father's
lifetime, which must be the true reason of these stirrings ; for they
were all set on foot before his now highness had done or refused one
ever." Thurloe remained however seci'etary of state. It was one of
the objects set before themselves by the royalists in this parliament,
who, by uniting with the republican party, formed a most troublesome
opposition to Richard Cromwell's government, to impeach Thurloe ;
but this object was yet undeveloped when the parliament was dissolved.
Thui'loe appears to have given strong counsel against the dissolution,
though it is generally stated otherwise, on the authority of the follow-
ing passage in Whitelocke: — "Richard advised with the Lord Broghill,
Fiennes, Thurloe, Wolsey, myself, and some others, whether it were
not fit to dissolve the present parliament : most of them were for it ;
I doubted the success of it " (p. 677). Those mentioned are very few
of the council, and, even if there had been no others, it would be
quite consistent with the words of this passage that Thurloe should
have sided with Whitelocke. That Thurloe strenuously opposed the
dissolution is distinctly stated, and with circumstantial mention of the
authority, in Calamy's Life of Howe, prefixed to Howe's \Vorkg, p. 9,
ed. 1724, fol. We know further that the dissolution was urged on
Richard Cromwell by the repubhcan and royalist parties, which were
united against Thurloe. Whitelocke says, a little afterwards, of the
dissolution, that it "caused much trouble in the minds of many honest
men; the cavaliers and republicans rejoiced at it." One of the "many
Papers,' vol. iii., pp. 420-60.) The immediate consequence of the
dissolution was the summoning, by Fleetwood and the council of
officers, of the Rump of the Long Parliament, and Richard Cromwell's
deposition.
The letters written during Richard Cromwell's short Protectorate,
in the third volume of Clarendon's ' State Papers,' arc full of acknow-
ledgments of Thurloe's influence with Richard Cromwell, and of the
importance attached to him by tho intriguing Royalists. Thus,
Cooper, one of Hyde's spies, writes to him, February 13, 1659, "Crom-
well is governed by Thurloe, whether for fear or love I know not ; but
sure it is, he hath power to dispose him against the sense of right,
or indeed his own interests. Thurloe's malice, I doubt, will never
sufi"er him to do us good" (p. 425). Again Hyde writes to another of
his agents, Brodrick, " There is nothing we have thought of more
importance, or have given moro in charge to our friends since tho
beginning of the parliament, than that they should advance all charges
and accusations against Thurloe and St. John, who will never think of
serving the king ; and if they two were thoroughly prosecuted, and
some of the members of the High Court of Justice, Cromwell's spirits
would fall apace " (p. 428). " It is strange," Hyde writes a month
after, March 10, 1659, "they have not in all this time fell upon Thurloe
and those other persons who advanced Cromwell's tyranny" (p. 436).
Then overtures to Thurloe to aid the king are thought of. " I do
39
THURLOE, JOHN.
THUELOW, LORD.
40
confess to you," Flydo writes, "I cannot comprehend why Thurloe,
and even his master St. John, should not be very ready to dispose
Cromwell to join with the king, and why they should not reasonably
promise themselves more particular advantages from thence than from
anything eUe that ia like to fall out" (p. 449). After the dissolution
of the parliament, serious thoughts seem to have been entertained of
soliciting Thurloe's and St. John's aid (p. 477). But Thurloe after-
wards becomes again au object of fear to Hyda During the govern-
ment by the army, he writes, " I do loss understand how Thurloe
shapes, and is iu danger to bo exempted out of the Act of Oblivion,
and at the satne time employed in the greatest secrets of the govern-
ment, for I have some reason to believe that he meddles as much as
ever in the foreign intelligence " (p. 532).
On the 14th of January 1660, Thurloe was succeeded in his office of
secretary of state by Scot, one of the republican party ; but he was
reappointed on the 27th of February. His patent as chief postmaster
hiwi been cancelled in the interval, on the 2nd of February. (' Com-
mons' Journals,' vol. vii. p. 533.) In the movements that followed for
the restoration of Charles II., Thurloe made an offer of his services to
those who were bringing about that event. Sir E. Hyde writes to
Sir John Grenville, April 23rd, 1660, " We have since I saw you,
received very frank overtures from Secretary Thurloe, with many great
professions of resolving to serve the king, and not only in his own
endeavours, but by the services of his friends, who are easily enough
guessed at. This comes through the hands of a person who will not
deceive us, nor is easily to be deceived himself, except by such bold
dissimulation of the other", which cannot be at first discerned. . . . The
kiug returned such answers as are fit, and desires to see some effects of
his good affection, and then he will find his service more acceptable."
(Thurloe's 'State Papere,' voL vii., p. 897.) And Hyde goes ou to in-
struct his correspondent to consult Monk as to Thurloe's character,
and as to his power to be of use, supposing he were sincerely willing.
Ou the 15 th of May Thurloe was accused by the parliament of high
treason, and ordered to be secured ; but on the 29th of June a vjste
was passed " allowing him liberty to attend the secretary of state, at
such times as they [the House] shall appoint, and for so long a time as
they shall own his attendance for the service of the state, without any
trouble or molestation during such attendance, and in his going and
returning to and from the secretary of state, any former order of this
House notwithstanding,"
After his release from imprisonment, he retired to Great Milton in
Oxfordshire, where he generally resided except in term-time, when he
occupied his chambers in Lincoln's Inn. It is said that he was often
solicited by Charles II. to resume public business, and always refused,
telling the king that he despaired of serving him as he had served
Cromwell, whose rule was to seek out men for places, and not places
for men. (Birch's 'Life of Thurloe,' prefixed to 'State Papers,'
p. xix ) Thurloe died at Lincoln' s-Inn on the 2l8t of February, 1668.
He had been twice married, and left four sons and two daughters,
all by his second wife, a sister of Sir Thomas Overbury. He was
possessed, during the days of power, of the manors of Whittlesey
St. Mary's and Whittlesey St. Andrew's, and the rectory of Whittle-
sey St. Mary's, in the Isle of Ely, and of Wisbech Castle which
he rebuilt. But after the Restoration they reverted to the Bishop
of Ely. There is an entry in the Commons' Journals of the 18th
of May 1660 : "Mr. Secretary Thurloe put out of the ordinance for
assessment of the Isle of Ely " (vol. viii. p. 36). Dr. Birch says he had
au estate of about 400Z. a-year at Astwood in Buckinghamshire. In a
monumental inscription to the memory of his son-in-law in St Paul's
Church, Bedford ('Cole's MSS.,' vol. iii., p. 43), Thurloe is described as
of Astwood, Bucks.
Thurloe does not appear to have possessed any striking qualities,
either moral or intellectual, to impress the minds of his contempo-
raries; and we know little else of him than that he had great powers of
business. Burnet describes him as " a very dexterous man at getting
intelligence." (' Hist, of his own Times,' i. 66.) From a story in
Burnet relative to Syndercomb's conspiracy against Cromwell, and
from what is said by Pepys of Morland, when assistant to Thurloe,
who played his master false, and gained a baronetcy from Charles II.
for his treachery, it might appear that he was not of a very generous
disposition, or much liked by those who were under him. Morland
attiibuted his misconduct to " Thurloa's bad usage of him." (Pepys,
' Diary' under May 13, and August 14, 1660. [Morland, Sir Samuel.]
Burnet's story is, that Thurloe treated lightly information which had
been given him of the design on Cromwell's life, and that when, on the
subsequent discovery of the design, Cromwell became aware that
information had been given to Thurloe, on which he had not acted,
and blamed Thurloe for his conduct, Thurloe availed himself of his
influence with the Protector to malign his informant ; " So he (the
informant) found," says Burnet, "how dangerous it was even to pre-
serve a prince (so he called him), when a minister was wounded in the
doing of it, and that the minister would be too hard for the prince,
even though his own safety was concerned iu it " (vol. i., p. 79).
Thurloe's | State Papers,' 7 vols, folio, 1742, contain a large mass of
rftcords of his official transactions, together with a number of private
letters and papers. They were edited by Dr. Birch, who gives the
following history of Thurloe's papers : " The principal part of this
qpUectiou consists of a series of papers discovered in the roign of King
William, in a false ceiling in the garrets belonging to Secretary
Thurloe's chambers. No. xiil, near the chapel in Lincoln's-Inn, by a
clergyman who had borrowed those chambers, during the long vacation,
of his friend Mr. Tomlinson, the owner of them. This clergyman
soon after disposed of the papers to the Right Honourable John Lord
Somers, then lord high chancellor of England, who caused them to be
bound up in 67 volumes in folio. These afterwards descended to Sir
Joseph Jekyll, master of the rolls ; upon whose decease they were pur-
chased by the late Mr. Fletcher Gyles, bookseller." They were published
by Mr. Gyles's executoi-s. Dr. Birch, the editor, received many other
papers from different individuals, especially from Lord Shelburne and
tho then Archbishop of Canterbury, which he has incorporated in the
collection. For historical purposes this is an invaluable collection.
THURLOW, EDWARD, LORD, was born in 1732, at Little Ash-
field near Stowmarket, in Suffolk. His father, Thomas Thurlow, was
a clergyman, and held successively the livings of Little Ashfield, and
of Stratton St. Mary's in Norfolk. After receiving the rudiments of
his education from his father, young Thurlow was sent to the gram-
mar-school at Canterbury at the suggestion of Dr. Donne, who sought
(as Southey states in his * Life of Cowper' upon the authority of Sir
Egerton Brydges) to gratify a malignant feeling towards the head-
master, by placing under his care '"a daring, refractory, clever boy,
who would be sure to torment him." The motive ascribed to Donne
is far-fetched, and seems improbable ; but there is no doubt that
Thurlow was educated at the Canterbury school, and that he continued
there several years, and until he was removed to Caius College, Cam-
bridge. His character and conduct at the university did not promise
any meritorious eminence in future life. He gained no academical
honours, and was compelled to leave Cambridge abruptly iu con-
sequence of turbulent and indecorous behaviour towards the dean of
his college. Soon after he quitted Cambridge he was entered as a
member of the ^ociety of the Inner Temple. In Michaelmas Term,
1754, he was called to the bar, and joined the Western Circuit in the
ensuiug spring.
Thurlow immediately applied himself to the practice of his profession
with great assiduity; and although he brought with him an indifferent
character from the university, he attained unusually early to reputa-
tion and employment both in Westminster Hall and on the circuit.
His name appears frequently iu the Law Reports soon after he was
called to the bar ; and his success in the profession he had chosen was
clearly ascertained in less than seven years from the commencement of
his practice. In 1761 he obtained the rank of king's counsel ; and it
may perhaps be inferred from an anecdote which is related by his
early friend and associate Cowper, in one of his letters (Cowper's
'Works,' vol. v., p. 254, Southey's edit), and which refers to this
period, that Thurlow had then acquired a degree of reputation which
suggested the prediction that he would eventually rise to the highest
office in his profession. A more convincing proof of his position in the
law is however recorded in the Reports, fx'om which it appears that
immediately after his appointment as king's counsel his practice in
the courts rapidly increased, and during ten years preceding his
appointment as solicitor-general, was exceeded only by that of Sir
Fletcher Norton, and one or two others of the most eminent advo-
cates of his tinie. To have succeeded so early and to so great an
extent, without adventitious aid from influence or connection, and in
competition with advocates of unquestioned ability and learning, ia
a substantial argument of professional merit. His employment iu
preparing and arranging the documentary evidence for the trial of the
appeal in the House of Lords against the decision of the Court of
Session in the Great Douglas Cause (which, according to professional
bringing his talents, industry, and legal acquirements under the imme-
diate notice of persons of power and influence, and of thus opening the
way to his subsequent elevation.
In the new parliament called in 1768 he was returned as member for
the borough of Tamworth, and became a constant and useful supporter
of Lord North's administration. Upon Dunning's resignation of the
office of solicitor-general in March 1770, and Blackstone's refusal to
accept it (' Life of Sir William Blackstone,' prefixed to Blackstone's
' Reports'), Thurlow received the appointment, and iu January 1771,
he succeeded Sir William De Grey as attorney-general. Soon after hia
introduction to office, he attracted the particular notice of George III.
by the zeal and energy displayed by him in supporting the policy of
Lord North's government respecting America, and in which the king
is known to have taken the warmest interest. Thurlow'a strenuous
and steady support of the minister in the great parliamentary contest
which ensued respecting that policy, procured for him a degree of con-
fidence and even of personal regard on the part of the king, which
continued unabated for upwards of twenty years, and had unquestion-
ably great influence in the remarkable vicissitudes of party which
occurred in that period.
In the summer of 1778 lord chancellor Bathurst resigned his oflSce ;
and on the 2nd of June in that year Thurlow was appointed his suc-
cessor, and raised to the peerage with the title of Baron Thurlow of
Ashfield in the county of Suffolk. Four years afterwards, in March
1782, when Lord North was removed from power, and the ephemeral
Rockingham administration was formed, Thurlow remained in posses-
sion of the great seal by the express command of the king, and in
41
THURLOW, LOKD.
THDRNEYSSER, LEONARD.
spite of Mr. Fox's opposition to bis continuance in office ; thus
furnishing au instance without a parallel in the history of English
party, of a lord chancellor retaining office under an administration to
all the leading features of whose policy he was resolutely opposed.
Nor was he content in this incousittent association to differ from his
colleagues in opinion only; on the contrary, he took no pains to
conceal his.hoatility to their principles, and even opposed in tho House
of Lords with all his characteristic energy the measures which they
unanimously supported. Thus, after the bill for preventing govel-n-
mcnt contractors from sitting in the House of Commons had been
introduced into the House of Lords, where it was supported by Lord
Shelburne and all the ministers in that house, tho lord chancellor loft
the woolsack, and himself moved that " the bill be not committed,"
denouncing the measure as " an attempt to deceive and betray the
people," and designating it " a jumble of contradictions." (Hansard's
'Pari. Hist.' vol. xxii. pp. 1356-1379.) The inconvenience produced
by this embarrassing disunion of councils was deeply fclb, and was one
of the principal reasons for Mr. Fox's retirement from administration,
on the death of the Marquis of llockinghum ; and when the admi-
nistration was dissolved in February 1783, upon the coalition formed
between Lord North and Mr. Fox, Lord Thurlow was compelled to
retire from office, notwithstanding the exertions of the king to retain
him. But though no longer chancellor, lie still continued to be one of
those who were described by Junius as " the king's friends," and was
supposed to have been his secret and confidential adviser during the
short reign of the Coalition ministry. Upon the dissolution of that
ministry at the end of the same year in which it was formed, the
great seal was restored to Lord Thurlow by Mr. Pitt, who then became
prime minister. He continued to hold the office of lord chancellor
for nine yesu-s after his reappointment : and until the occurrence of
the king's madness in 1788, appeared to act cordially with the rest of
the cabinet; but when that event rendered a change of councils by
means of a regency probable, he was suspected, with good reason, of
some intriguing communications with the Prince of Wales and the
Whigs (Moore's ' Life of Sheridan,' vol. ii. chap, xiii.), and was always
subsequently regarded with distrust by Pitt and his colleagues. On
the other hand. Lord Thurlow took no pains to conceal his dislike of
Pitt; and that minister felt himself so embarrassed by the chancellor's
personal hostility to him, that in 1789 he complained to the king, who
immediately wrote to Thurlow upon the subject, and obtained from
him a satisfactory answer. His angry feeling however still continued,
until at length, in 1792, probably relying upon his personal influence
with the king, he ventured to adopt a similar course to that which he
had followed in very different circumstances under the Rockingham
administration, and actually opposed several measures brought into
parliament by the government. In particular he violently opposed
Mr. Pitt's favourite scheme for continuing the Sinking Fund, and
voted against it in the House of Lords, though he had never expressed
his dissent from the measure in the cabinet. This kind of opposition,
- though submitted to from necessity by a weak government like that
of the Marquis of Rockingham, could not be endured by so powerful
a minister as Pitt ; and on the next day he informed the king that
either the lord chancellor or himself must retire from the administra-
tion. The king, without any struggle or even apparent reluctance, at
once consented to the removal of Lord Thurlow, who was acquainted
by command of his majesty that he mu.st resign the great seal upon
the prorogation of parliament. Lord Thurlow is said to have been
deeply mortified by this conduct on the part of the king; and he is
related to have declared in conversation that "no man had a right to
treat another as the king had treated him." Subsequently to his
notice of dismissal, and before he quitted office, his ill humour was
displayed by his opposition to another measure prepared and supported
by Mr. Pitt, the object of which was the encouragement of the growth
of timber in the New Forest. On this occasion he reflected severely
upon those who advised the king upon this measure, and went so far
as to say that his majesty had been imposed upon. (Tomline's ' Life
of Pitt,' vol. iii. p. 398-99.) One of his latest acts as lord chancellor
was to sign a protest in the House of Lords against Mr. Fox's Libel
Act. The opportunity of his retirement from office was taken to
grant him a new patent, by which he was created Baron Thurlow, of
Thurlow, in the county of Suffolk, with remainder, failing his male
issue, to his three nephews, one of whom afterwards succeeded to the
title under this limitation.
After his retirement from office in 1792, Lord Thurlow ceased to
take any hading part in politics, and havicg little personal influence
with any party, became insignificant as a public character. He occa-
sioually spoke in the House of Lords on the subjects of interest which
were discussed at the period of the French revolution; and it is
worthy of remark that he frequently opposed the measures adopted
by the Tory government at that time for the suppression of popular
disturbances. Instances of this occur with respect to the Treasonable
Practices Bill and the Seditious Meetings Bill, in 1795; and a com-
parison of the sentiments expressed by him on these occasions, with
his speeches respecting America during Lord North's administration,
affords a striking example of political inconsistency. A circumstance
is recorded in the 'Memoirs of Sir Samuel Romilly' (vol. ii. p. 124),
which proves that within a few months of his death Lord Thurlow
was still confidentially consulted by members of the royal family.
On occasion of the first communication of the charges made by Ladj
Douglas against the priucesH of Walea in 1805, the priace (afterward*
George IV.) directed that Thurlow should be coDBulted, and the [jar-
ticulars of the interview between him and Sir Samuel Itomilly are
characteristic and interesting. Lord Thurlow died at BrigbtoD on the
12th of September 1826, after an illneu of two yean.
THURMER, JOSEPH, a German architect of some note, waa bom
at Miinich, November 3, 1789, but did not begin to apply himself to
architecture professionally until 1817, when be became a pupil of
Professor Fischer's, and had for his fellow-students Gaertner, 2^blaiid,
OhlmuUcr [Gaf.rtneii; Oulmulleb], and many others who have
since rendered tbemsolvea more or lees diiitinguished. At the end of
the following year (after a previous visit to Rome at the commence-
ment of it) he joined Hubich, Heger (died 1837), and Koch, in a pro-
fessional excursion to Greece, where he spent five months in studying
and drawing the remains of buildings at Athens, some few of which
he published on his return, with the title of * Ansichtcn von Athen
und seine Denkmaler,' 1823-26. He did not however confine himself
to the study of tlie Grecian style, nor was he such a prt-judiced
admirer of it as to have no relish for any other; on the contrary, he
considered the Italian style of the time of Leo X. to be equally
worthy of the architect's attention, and to deserve to bo far better,
more faithfully and tastefully, represented by means of engraving*
than it had previously been. He accordingly joined with Gutensoba
in bringing out a ' Sammlung von Denkmaler,' &c., ' Collection of
Architectural Studies, and Decorations from Buildings at Itome, of
the fifteenth and sixteenth centuries,' the first number of which ap-
peared in 1826 ; but, unfortunately, it did not meet with the encourage-
ment it deserved, and was therefore given up, when very little progree*
to Thurmer, since it recommended him to notice, and led to hi*
receiving (1827) at the same timo two different invitations, one from
Frankfurt, the other from Dresden, to which last he gave the pre-
ference. He was there made professor-extraordinary at the school of
architecture, and in 1832 was promoted to be first professor of
architecture, in which capacity he did much for the advancement of
the art and the improvement of taste. Though he has left very little
executed by himself in that city, the only public building in it entirely
by him being the post-office (for though the ' Hauptwachc,' or guard-
house, was erected by him, it was after Schinkel's designs), his
opinions had a very beneficial influence. That he should have had so
few opportunities for displaying his ability, is not very surprising, nor
does it detract from his reputation, since he did not long survive the
completion of his first edifice : he died November 13th, 1833, while
staying at Miinich. What he might have done, had a longer life been
granted him, is shown by the number of designs he left, all more or
less stamped by originality and artistical feeling. That the grateful
regard expressed for his memory and his talents by his friends and
pupils was not a mere temporary effusion, is proved by their having
erected a bronze bust and monument to him, in 1838, at the Academy
of Arts.
THURNEYS3ER ZUM THUIIN, LEONARD, a celebraf«d alche*
mist and astrologer, was born in 1530 at Basle, where his father
carried on the trade of a goldsmith. He was himself brought up to
this employment, but he was obliged to leave his native place when
eighteen years of age, on account of having sold to a Jew a piece of
gilt lead for pure gold. He first went to England, thence to France,
and afterwards to Germany, where he enlisted among the troops of
the margrave of Brandenburg. The following year he was taken
prisoner ; from that time he gave up a military life, and having visited
the mines and foundries of Germany and the north of Europe, he
came back in 1551 to Nurnberg, Strasburg, and Kostnitz. Here he
again carried on the trade of a goldsmith, and made much money by
it, till on account of his reputation for skill in the art of mining, he
was sent for to the Tyrol to superintend different mineral works.
Accordingly in 1558 he went to Tarenz in Upper Innthal, and esUb-
lished on his own account in that place, as well as at St. Leonard,
foundries for the purifving of sulphur, the success of which contributed
still more to his celebrity. The Archduke Ferdinand had so much
confidence in him that he sent him to travel in Scotland, the Orkney
Islands, Spain, and Portugal. Thumeysser also visited the coasts of
Barbary, Ethiopia, Egypt, Ambia, Syria, and Palestine, and retimied
to the Tyrol in 1567. Two vears afterwards, at the request of the
same prince, he again visited the mines of Hungary and Bohemia.
Tho publication of his works made him determme to go to Munster
and Frankfurt on the Oder, at which latter place he became acquamted
with the elector of Brandenburg, whoso wife he cured of a dangerous
illness, and who reBolved to attach him to his sei-vice m the hope that
he might discover in his estates some unknown mineral treasures.
Thurneysser accepted the office of physician to the pnnce, and accom-
panied him to Berlin, where, from his skill in profiting by the pr^
judices and weaknesses of his contemporaries, andfrom being acquaintea
with all the resources of charlatanism, he soon succeeded not only in
acquiring considerable wealth, but also in passing himself off for one
of the most learned and scientific men of his age. At length however,
by the envy of others, and still more by his own imprudence, h^^ decep-
tions were discovered, and he was, in 1584, obliged to lea^^i>erhu^
He went to Prague, Cologne, and Rome ; and after having thus led a
43
TIARINI, ALES3ANDR0.
TIBERIUS CLAUDIUS NERO.
4i
wandering life for some years, he died at last in a convent at Cologne,
at the age of sixty-six, in 1596. He was an advocate for the pretended
sciences of alchemy and uromancy, and his whole history (like that of
most similar characters) is a proof of tho influenco that may be
acquired in an ignorant age by a bold and enterprising man, when he
possesses soma little iufurmation above the generality of his contem-
poraries. His writings were numerous, but of little worth, and they
are now very seldom looked into. Tho titles of twelve of them are
given in the ' Biographie M«$dicale,' from which work the preceding account is taken. TIARl'NI, ALESSANDRO, one of the most celebrated painters of tho Bolo^neso school, was born at Bologna in 1577. Ho first studied under Prospcro Fontana, and, after Fontana's death in 1597, under IJartolomeo Cesi ; but having in a quarrel discharged a pistol or similar weapon at a fellow-scholar, without however doing him any injury, he was obliged to fly from Bologna. He went to Florence, and there engaged himself with a portrait-painter, for whom he painted hands and draperies, and some of his performances having attracted the notice of Domenico da Passignano, ho was admitted by that painter into his studio as a scholar. Tiarini remained with Passignano seven years, and by that time acquired so great a reputation, that he received invitations from Bologna to return to that city. In Bologna his works excited universal admiration for their invention and earnestness of character, and for their boldness of foreshortening, correctness of design, and propriety of colouring : the tone of Tiarini's pictures is sombre; he used little red, and avoided gay colours generally. His works, which are very numerous, consist, chiefly in oil-paintings; he executed com- paratively little in fresco : those in public places alone, in Bologna and its vicinity, and in Mantua, Modena, Reggio, Parma, Cremona, and Pavia, amount to upwards of two hundred : their subjects are gene- rally of a melancholy or serious nature. The following are the most celebrated : — A Miracle of St. Dominic, in the Capella del Rosario, iu the church of San Domenico at Bologna, painted in competition with LioncUo Spada, in which the saint restores a dead child to life; tho exhumation of a dead monk, in the convent of San Michele in Bosco ; and St. Peter repenting his Denial of Christ, standing out- side the door of the house of the high priest, with the Mocking of Clirist iu the background, illuminated by torchlight. Ludovico Caracci, whose style Tiarini ultimately adopted, was a great admirer of his works : when he first saw Tiarini's picture of the Miracle of San Domenico, he is reported to have exclaimed that he knew no living master that could be compared with Tiaiini. Many of Tiarini's pictures, out of Bologna, have been attributed to one or other of tho Caracci : such was the case with the celebrated Deposi- tion from the Cross, now in the Gallery of the Academy of Bologna, formerly in the church of the college of Montalto : it is engraved iu the work of Kosaspini, ' La Pinacoteca della Ponteficia Accademia dcllo Belle Arti in Bologna.' Several of Tiarini's jjictures have lost their colour, owing to his practice of gLizing ; in some tlio colouring consists entirely of glazed tints, the design being executed in grey. He opened a life academy in Bologna, and had many scholars. Malvasia has preserved the nama of a famous model that he used frequently to engage, Valstrago. Tiarini died in 1G68, aged ninety-one. TIBALDEO. [Tebaldeo.] TIBALDI, PELLEGRI'NO, otherwise called Pelligrino Pellegrini, or sometimes Pellogrino da Bologna, distinguished himself both iu painting and in architecture. He was born in 1527, at Bologna, where his father, who originally came from Valsolda in the Mdanese territory, was only a common mason. How, so circumstanced, the fatl)er was able to bring up his son to a profession requiring means beyond those of his own condition in life, does not appear; neither is it known from whom Tibaldi received his first instruction in painting. In 1547 he visited Rome, with tho intention, it is said, of studying under Pierino del Vaga, but as the latter died in that same year, he could hardly have received any lessons from him. Whether he became a pupil of Michael Agnolo is unknown : he certainly studied his works very successfully, for while he caught from them grandeur of style and energy of forms, he so attempered their severity by the freedom and grace of his pencil, that he afterwards acquired from the Caracci the name of ' Michelagnolo Riformato,' and may be considered as the originator of that style which they perfected. We must how- ever conclude that although he was employed tliere in the church of 8. Lodovico di Francesi, he did not display any great ability with his pencil during his residence at Rome, it being related of him that he felt so discouraged as to have determined to starve himself to death, from which desperate resolution he was withheld only by Ottaviano Mascherino, who advised him to give up painting and devote himself entirely to architecture, for which he had shown considerable taste. In all probability this anecdote has been strangely exaggerated, nor are we informed how he set about putting Mascherino's advice into practice. That he partly adopted it, is certain, and equally certain that if he renounced painting for a while, ho returned to it : in fact, not very long after the circumstance just spoken of, he was sent to Bologna by Cardinal Poggio to adorn his palace (afterwards occupied by the Academia Clementina), where he painted the history of Ulysses. For the same prelate he also painted the Poggi Chapel, which had been erected after Tibaldi'a own designs, and it was those productions which excited tho admiration of the Caracci. He was next employed at Loretto and Ancona, where ho executed several works in fresco, and among them those with which he adorned the Sala de' Mercanti, or Exchange, in the last-mentioned city. His reputation as an architect in the meanwhile increased, and after being employed to design, if not to execute, several buildings at Bologna, and the Palazzo della Sapiensa, or Collegio Borromeo, at Pavia (which last was begun by Cardinal Carlo Borromeo in 1564), he restored the Archiepiscopal Palace at Milan, and was appointed chief architect of the Duomo, or cathedral, in that city (1570). He suggested the idea or firat design of the modern facade attached to that celebrated Gothic structure, — a design which has obtained him both praise and censure in almost equal degree. Among other buildings by him at Milan are the church of San Lorenzo, that of S. Fedele, and that of the Jesuits. But the work which, if less cele- brated than some of his others, is considered by one of his critics his chef-d'oeuvre, and a masterpiece for the contrivance and ability shown in it, is the ' Casa Profcssa,' or that of the Jesuits at Genoa, with its church, &c., where he completely mastered all the difiiculties arising from the inconvenience of the site. Neither his fame nor his works were confined to Italy, for the former caused him to be invited to Spain in 1586, by Philip II., where he was employed both in his capacity of architect and in that of painter, in which last he executed many atlmirable frescoes in the Escurial. Liberally rewarded by Philip, who also conferred on him the title of Marquis of Valsolda (his birthplace), Tibaldi returned to Italy after passing about nine years in Spain, and died at Milan in 1593; such at least is the date assigned by Tiraboschi, though some make it much earlier, 1590 or 1591, and others about as much later, viz. 1606. (Tiraboschi ; Lanzi ; Milizia ; Zanotti ; Nagler.) TIBALDI, DOMENICO, younger brother, not son of the preceding, as he is sometimes called, was born in 1541, and was, if not equally celebrated, like him both a painter and architect, but ranks far higher in the latter than in the other character. He executed many buildings at Bologna, the principal among which are the Palazzo Magnani, the Dogana, or custom-house, the chapel in the cathedral, so greatly admired by Clement VIII. as being superior to anything of the kind at Rome, and the small church of the Madonna del Borgo, Domenico also practised engraving with success, and in that branch of art w.^s the instructor of Agostino Caracci. He died at Bologna in 1583. TIBE'RIUS CLAU'DIUS NERO was born in Rome, on the 16th November, B.C. 42, according to Suetonius. He belonged to the gens Claudia, an old patrician family of great distinction, which was known for its aristocratical pride. Tiberius belonged to this house by the side of his father, Tiberius Claudius Nero, as well as his mother, Livia Drusilla, who was the niece of her husband, being the daughter of Appius Pulcher. Tliis Appius Pulcher was a brother of Tiberius Claudius Nero the elder, and they were both sons of Appius Ctecua. His father was qusostor to C. Julius Caesar, and distinguished himself as commander of the fleet in the Alexandrian v^ar. He became succes- sively prajtor and pontifex, and in the civil troubles during the triumvirate he followed the party of M. Antonius. Being compelled by Octavianus to fly from Rome, he escaped by sea, and hastened to M. Antonius, who "was then in Greece. His wife and his infant son accompanied him in his flight, and they happily escaped. Tiberius the elder soon made his peace with Octavianus ; he gave up to him his wife, Livia Drusilla, who was then pregnant with Nero Claudius Drusus, and he died shortly afterwards (b.c. 38). Thus Tiberius the younger and his brother Nero Claudius Drusus became stepsons of Octavianus, who from the year B.C. 27 was Augustus. The great talents of Tiberius were developed at a very early age. In his ninth year he delivered a public speech in honour of his father ; in B.C. 29 he accompanied Octavianus in his triumph after the battle of Actium, and rode on his left side, Marcellus being on the right. After having assumed the toga virilis, he distinguished himself by splendid entertainments which he gave to the people. He married Vipsania Agrippina, the daughter of Agrippa, and the granddaughter of Cicero's friend T. Pomponius Atticus. She brought him a son, Drusus, and she was again with child when Tiberius was obliged to sacrifice her to the policy of Augustus, who compelled him ,to marry his daughter Julia, the widow of Marcellus and of Agrippa, and the mother of Caius and Lucius Csesar. (b.c. 12.) Tiberius obeyed reluctantly, but he never ceased to love Vipsania. Such was his affection for her, that whenever he saw his repudiated wife he would follow her with tears ; and accordingly an order was given that Agrippina should never appear in sight of Tiberius. For some time Tiberius lived in hai-mony with Julia, and had a son by her, who died young. But the scanda- lous conduct of Julia soon disgusted him, and he withdrew from all intimate intercourse with her. During this time Tiberius took an active part in public affairs. He defended the interests of King Archelaus (of Judaea, or of Cappadocia), of the Tralliani, and of the Thessalians ; he was active in obtaining relief for the inhabitants of Laodicea, of Thyatira, and of Chios, who, having suff'ered from an earthquake, had implored the assistance of the senate : he pleaded against Fannius Cccpio, who had conspired against Augustus, and who was condemned for high treason; and he was twice intrusted with the ' cura annonrc.' Tiberius made his first campaign as Tribunus militum in the Cantabriaa war. From Spain 45 TIBERIUS CLAUDIUS NERO. TIBERIUS CLAUDIUS NERO. be went to Asia Minor, and succeeded in restoring Tigranes to tbe I throne of Armenia, and in forcing the Parthiana to aurreuder the eagles which they liad taken from M. Crassus. He returned to Rome ill B.C. 18. During a year he had the commaud in Gallia Comata, the peace of which province was troubled by disputes between the princes and by incursions of the barbarians. In n.c. 15 he and his brother Drusus brought the Alpine nations of Rhactia to obedience. He also put an end to the war in Pannonia, which had lasted since B.C. 18, and which ho terminated by subduing the Breuci, the Scordisci, aud the Dalmata?, who were allied with the Pannonians. (b.c. 14.) The Germani having defeated M. Lollius and taken the eagle of the fifth legion in B.C. 16. (Velleius Paterculus, ii, 97), Drusus was sent to the Rhine, and Tiberius returned to Rome, where he celebrated his first triumph. In the llhrotian war Tiberius had shown great military skill, but tbe Romans carried on the war with unheard-of cruelties against the inhabitants, of whom the majority were killed or carried ofif as slaves. In memory of his victories, a monument was erected at Torba (now Monaco, in the neighbourhood of Nizza), on which the names of forty-five llha3tian tribes were inscribed. (Plinius, ' Hist. Nat.,' iii. 24.) In B.C. 13 Tiberius was appointed consul, together with P. Quintilius Varus. Meanwhile Drusus carried on the war in Germany with great success ; but in B.C. 9, on his retreat from the banks of the Elbe to the Rhine, he had a fall from his horse, wLicb proved fatal. Tiberius was then at Pavia, but as soon as he was informed of this accident, he hastened to Germany, and arrived in the camp of bis brother, near the Yssel and the Rhine, just before he died. I'iberius led thu army to Mainz (Moguntiacum). He ordered the body of his brother to be carried to Rome, and he accompanied it on foot. After discharging this pious duty, be returned to Germany. In the new war with the Germani, Tiberius at first defeated them, and transplanted 40,000 Sigambri from the right bank of the lower Rhine to the left bank ; but he afterwards employed peaceable measures, and by negociation he obtained more influence over them than bis brother Drusus by all his victories. (Velleius Paterculus, iL 97 ; Tacitus, ' Annal.,' ii. 26.) He left the command in Germany in B.C. 7, and returned to Rome, where he celebrated his second triumph, and be was consul for the second time in tbe same year. Tiberius was now at the height of his fame ; he was respected by the army, and admired by the people ; and be enjoyed the confidence of the emperor. He nevertheless suddenly abandoned his important functions, left Rome, and, without communicating his motives to anybody, retired to the island of Rhodes. So firm was bis resolution to retire from public afiairs, that be refused to take any nourishment for four days, in order to show his mother that her prayers and tears could not keep him any longer in Rome. (Suetonius, * Tiberius,' c. 10.) During eight years he led a private life at Rhodes, renouncing all honours, and living in the Greek style, and on terms of equality with those around him, with whom he kept up a friendly intercourse, especially Greek philo.'^ophers and poets. The Romans were surprised to see tbe step-son of their emperor retire to a distant island ; Sknd various hypotheses were raised to explain the motive of his voluntary exile. The disgusting conduct of his wife Julia was supposed to be a sufficient cause for this extraordinary resolution ; but Tiberius him- self afterwards avowed that Le bad renounced public business in order to escape all charges of having formed ambitious schemes against his step-sons Caius and Lucius Caesar, who were created ' principes juven- tutis,' and appointed successors of Augustus in tbe very year in which Tiberius went to Rhodes. It seems that be was dissatisfied with the elevation of these two young men, and that there was discord between him and them ; for when he afterwards wished to go back to Rome, Augustus would not allow it until Caius Caesar had consented, and it was also on condition that he should take no part in the government of the state. From all this we may conclude that Tiberius and his mother Livia bad perhaps been intriguing to exclude Caius and Lucius Csesar from the succession, and that he preferred a voluntary exile to a compulsory banishment, such as was inflicted by Augustus upon his own daughter Julia. But this is mere supposition, and there are no facts on which a direct accusation against Tiberius can be sustained. With regard to his banished wife Julia, Tiberius acted with great delicacy, notwithstanding her conduct, and he besought Augustus to leave her all those presents which he had formerly given her. (Sue- tonius, 'Tiberius,' c. 12, 13.) At last Tiberius returned to Rome (a.d. 2), and was received by the people with demonstrations of great joy. In the same year Lucius Csesar died at Massilia (Marseille), and his death was followed by that of his brother, who died in a.d. 4, in consequence of a wound which he had received in the Parthian war. Augustus then adopted Tiberius as his future successor, in a.d. 4, and Tiberius in his turn was compelled by Augustus to adopt Drusus Germanicus, the son of his late brother Drusus Nero. Augustus also adopted M. Agrippa, the posthumous son of Agrippa and Julia, but he did not designate him as a successor in the empire. The imperial throne was thus secured to the house of the Claudii. In the same year (a.d. 4) Tiberius was appointed commander-in-chief in Germany, and he was accompanied by the historian Velleius Paterculus, who was prsefectus equitum. After having subdued the Bructeri, and renewed the alliance with the Chatti, Tiberius iu a.d. 5 made a cam- paign against the Longobards, who were defeated ; and he obliged the whole north-west of Oermnny to acknowledge tbe Boman authoritj. In the following year (a.d. 6) he led 70,000 foot and 4000 horae againat Maroboduua, the king of the Marcomanni, who wiu aaved from ruio by a rising of the inhabitante of Pannonia and northern Illyricum, who intercepted the communicutions of the Roman army with Italy. Tiberius employed fifteen legions and an equal uumbor of auxiliariea, against these nations, and, in spite of difiiculti*-* of every descriptioo, ho quelled the outbreak within three years. Thin war wua t^si>eoially dangerous becauEe the Germani threatened to join tbe Panuoniaua, but Tiberius prevented their junction by negociation« and by the success of his arms. After having celebrated his third triumph, he was again sent against the Germani, who had alain Varus aud hia army (a.d. 9). Tiberius, who was accompanied by Germanicus, auo- ceeded in preventing the Germani from invading the countries on the left bauk of the Rhine, and he then celebrated hia fourth triumph. Velleius Paterculus, an able judge of military talents, gives us a moat favourable idea of him as a general. Suetonius says al*o that, siiaring in all the hardships of the common soldiers, be maintained a aevere disciplme, but at the same time he carefully watched over the aecority and the comfort of the soldiers. Augustus died at Nola on his return from Naplea, where he bad accompanied Tiberius, who was going to conduct the war in Illyria (29th of August, a.d. 14). Anxious to sec her son at that critical moment in Rome, Livia concealed the emperor's death until Tiberius, who was informed of it by messengers, had arrived at Nola. (Dio. Casnius, vL 30, 31.) Tiberius became enc peror in his fifty-fifth year, at an age when both the virtues and the vices have acquired strength from habit, and when a man's character seldom changes. Until that time he was generally supposed to be a virtuous man; his virtues were imbued with tbe severe gravity of his character. Among his biographers none haa blamed his early life; yet no sooner was he emperor, than he was charfied with crimes the most dreadful and disgusting. Hia former life is represented as dissimulation and hypocrisy. An example 4jf such dissimulation is known in history. Sixtua V. concealed bis real intentions for thirty years ; however it was not his real character which he thus concealed ; but by retiring from affairs, and by simu- lating disease and infirmity, he made the cardinals believe that by choosing him pope they would make him their instrument, because hi infirmities would not allow him to act with energy. Tiberius however, except the eight years that he spent in Rhodes, was con8tant4y employed in matters which, although they would have allowed him to conceal his real disposition, he could never have managed with such success, unless his conduct had been directed by the force of his real character. Augustus succeeded in making himself master of the republic by accumulating in his person the different high functions of the state. Tiberius, proud and energetic, abolished even the shadow of the sovereignty of a nation which he despised. The Romans being suffi- ciently disposed to obedience, the only obstacles in his way were the worn-out institutions of the ancient republic. Immediately upon the accession of Tiberius, Agrippa Postumus was put to death, probably by order of Tiberius (Suetonius, ' Tiberius,' c. 22 ; Tacitus, ' Annal.,' i. 6.) About this time the supreme power was offered by the troops on the Lower Rhine to Germanicus, who however refused it ; and the mutiny was quelled by him and by Drusus, the son of Tiberius, who commanded in Pannonia. Tiberius began by some enactments which tended to ameliorate the state of morals ; he abolished the comitia for the election of the various officers of the state, and transferred the election to the senate, the members of which were subservient to him. It has been already said that Tiberius intended to destroy the last remnants of the ancient sovereignty of the people, and to supplant the majesty of the Roman nation by the majesty of the emperor. Augustus had already employed the Lex Julia Majestatis to punish the authors of libels against his person (Tacitus, ' Annal.,' i. 72) ; and his example was followed by Tiberius, who established the Judicia Majestatis, by which all those who were suspected of having impugned the majesty of the emperor either by deeds or words, were prosecuted with the utmost severity. The number of the delatores, or denouncers of such crimes, daily increased, and a secret police was gradually established in Rome, as well organised and as well supported by spies as the secret police of Napoleon. The property, honour, and life of the citizens were exposed to the most imfounded calumnies, and a general feeling of anxiety and moral disease pi-evailed throughout the empire. The natural severity of Tiberius gradually degenerated into cruelty, and he showed symptoms of that misanthropy and that gloomy state of mind which increased with years. In the meantime Germani- cus, the favourite of the army, had avenged the defeat of Varus, but Tiberius recalled him from Germany, and sent him into the East (a.d. 17). Germanicus conquered Cilicia and Commagene, and he renewed the alliance with the Parthians, but he died suddenly at Antioch (a.d. 1 9.) Public opinion accused Cneius Piso, the commander in Syria, of having poisoned Germanicus by order of the emperor ; but before Piso could be sent to trial, he was found dead. Sejanus, the son of a Praefectus Prsetorio, succeeded in obtaining the confidence of the emperor (a.d. 19-22), who henceforth gradually abandoned to him the direction of public affairs, of which Sejanus became the absolute master from the year a.d. 22. [Sejanus, a TIBERIUS II. TIBERIUS II. 18 Ldoitjs M.'\ Drusus, the eon of Tiberius, who bad governed the Roman part of Germany with great ability, was poisoned by Sejanus (a.d. 23), and this crime was followed by a great many others, with which it is possible that the emperor was very imperfectly acquainted. His practice was to shut himself up within his palace, and to speud his time in the most revolting debauchery. After the death of Drusus, Tiberius recommended to the senate as his successors Nero and Drusus, the sons of the unfortunate Germanicus and of Agrippina, who was still alive. In a.d. 26 Sejanus at last persuaded him to retire from public affaire. Tiberius followed his advice, and went to Capua and Nola, until at last he fixed his residence on the island of Capreso in the Gulf of Naples, The life which he led at Caprese was a series of infamous pleasures. From this time all public affairs were directed by Sejanus : the emperor was inaccessible. T. Sabinus, a friend of Nero, was put to death ; statues were erected to Sejanus, and received divine honours. After the death of Livia, in a.d. 29, the authority of Sejanus was at its height; but at last Antonio, the aged mother of Germanicus, penetrated through the barriers of Caprese, and informed the aged Tiberius that Sejanus had left him only the name of emperor. She was supported by Macro, the commander of the Praetorian guard. In consequence of this information, Tiberius ordered the senate to con- demn Sejanus ; and the senate obeyed : Sejanus, his family, and his friends, were put to death in a.d. 31. Some time after this event, Tiberius retired from Caprese, and took up his residence at a villa near Misenum, which had formerly belonged to LucuUus. (Suetonius, 'Tiberius,' c. 73.) On the 16th of March a.d, 37, he fell into a lethargy, and everybody believing him to be dead, Caligula, the third son of Germanicus, the favourite of old Tiberius, was proclaimed emperor. However, Tiberius recovered, and Macro, in order to save himself and the new emperor, ordered hira to be suffocated in his bed. Thus died Tiberius, at the age of seventy-eight, after a reign of twenty-three years. (Tacitus, ' Annal.,' vi. 50 ; Suetonius, ' Tiberius,' c. 73.) There is little doubt that the crimes said to have been committed during the reign of Tiberius, either by himself or by others in his name, are real facts. But the question is whether they are all to be imputed as crimes to Tiberius. His insanity is a fact which can hardly be doubted; a dark melancholy, disgust of life, and misan- thropy, had taken possession of him, and his struggle with the idea of self-destruction often threw him into wild despair. He found consolation in the sufferings of others, and thus gave those bloody orders which he afterwards regretted. The unnatural pleasures to which he was addicted were only another mode of soothing the despair of his soul. It is probable that his insanity was complete when he retired to Caprese. Sometimes he had lucid intervals, in which he wrote those letters of which Suetonius gives some extracts (' Tiberius,' c. 67), and in which he confesses the wretched state of his soul. His physical health was excellent, until some days before his death. Tiberius loved the arts and literature. According to Suetonius, he wrote a lyric poem, * Conquestio de L. Csesai'is Morte ; ' he also wrote poems in Greek, choosing for his models Euphorion, Rhianus, and Parthenius, the author of an erotic poem which has come down to us. (Suetonius, Tiberius; Velleius Paterculus, ii., c. 94, &c. ; Tacitus, Annal., lib. L-vi. ; Dion Cassius, lib. xlvL-xlviii. ; Horn, Tiberius, cin Historisches Gemcilde. The character of Tiberius has been defended by Buchholz, Philosophische Untersuchungen, vol. ii., p. 49, &c.) TIBK'RIUS II., ANI'CIUS THRAX, FLA'VIUS CONSTAX- TI'NUS, one of the greatest and most vii-tuous emperors of the east. He was born in Thrace towards the middle of the 6th century, and belonged to a rich and very distinguished family, the history of which is unknown to us. He was educated at the court of Justinian, whose successor, Justin II. (565-78), loved him as his eon, and employed him in various civil and military offices. In 573 Tiberius, who was then general of the imperial guards, commanded the army against the Avars, who were powerful north of the Save and the Danube. His lieutenant having neglected to watch the passages of the Danube, Tiberius was surprised by the Avars and lost a battle. However, he recovered this loss, and concluded a peace, by which the possession of the important fortress of Sirmium, now Mitrowicz, on the Save, near its junction with the Danube, was secured to the Romans. This was one of the few advantages obtained by the Greek armies during the unfortunate reign of Justin II. Italy, which had been conquered by Justinian, was overrun by the Longobards ; the Berbers ravaged the kingdom of Carthage, which had been taken from the Vandals ; and on the Persian frontier Chosroes (Kliosrew) made various conquests. Justin, feeling his incompetency, and having lost his son, looked for a regent, and his choice fell upon Tiberius. The great talents of Tibe- rius, his amiable character, his generosity and love of justice, and his .sincere piety, had won him the hearts of the nation, and the esteem of the emperor and his ministers. Justin was confirmed in his choice by the empress Sophia, whose private views on this occasion harmo- nised with the interest of the state. Tiberius was the handsomest man at the court, and it seems that Sophia intended to marry him en the death of Justin. However this may be, before she declared in his favour she asked him whether he was married. Tiberius imme- diately guessed the motive of the question, and answered that he was not, although he was secretly married to a lady named Anastasia. He thus gained the protection of the empress, and was proclaimed Csesar by Justin on the 7th of December 574, in a most solemn assembly of the civil and military officers, and of the clergy under the presidency of the patriarch Eutychius, by whom Tiberius was crowned with the imperial diadem. In this assembly the emperor Justin addressed to his future successor the remarkable speech (Theophylactus, iii. 11), which Gibbon translates thus : — " You behold the ensigns of supreme power. You are about to receive them, not from my hand, but from the hand of God. Honour them, and from them you will derive honour. Respect the empress your mother — you are now her son — before, you were her servant. Delight not in blood, abstain from revenge, avoid those actions by which I have incurred the public hatred, and consult the experience rather than the example of your predecessor. As a man, I have sinned ; as a sinner, even in this life I have been severely punished : but these servants (his ministers), who have abused my confidence and inflamed my passion, will appear with me before the tribunal of Christ. I have been dazzled by the splendour of the diadem : be thou wise and modest ; remember what you have been, remember what you are." To this speech of a dying sinner, Tiberius answered, " If you consent, I live ; if you command, I die : may the God of heaven and earth infuse into your heart what- ever I have neglected or forgotten." The burden of government devolved upon Tiberius, whose authority was never checked by Justin. The war with Persia prevented Tibe- rius from expelling the Longobards from Italy ; but he sent there all the troops he could dispose of, and succeeded in maintaining the imperial authority in the exarchate of Ravenna, on the Ligurian coast, in the fortified places in the Cottian Alps, in Rome, in Naples, and in the greater part of Campania and of Lucauia. He saved Rome and Pope Pelagius II. from the Longobards by sending a fleet laden with provisions (775). Some years later he concluded an alliance with the Frankish king Chilperic, who checked the Longobards in the north of Italy, and Tiberius succeeded in bribing several of the thirty Longo- bardian dukes, who, after the murder of King Clepho (573-74) and during the minority of Antharis, imitated in Italy the Thirty Tyrants of Athens. The daughter of King Alboin and Rosamond, who had fled from Italy, was then living at the court of Constantinople. The most important event in the reigns of Justin and Tiberius was the war with Persia. Khosrew, the king of Persia, had made extensive conquests in Asia Minor during the reign of Justin, In 575 Tiberius concluded a partial truce for three years with him, on condition that hostilities should cease except on the frontiers of Armenia, where the war was still carried on. These frontiers being easily defended on account of the great number of defiles in the Armenian Mountains, Tiberius levied a strong army while Khosrew lost time iu forcing passages or in besieging small fortified places. For several centuries the Eastern empire had not seen such an army as was then raised by Tiberius. A hundred and fifty thousand men, among whom were many Teutonic and Slavonic barbarians, crossed the Bosporus in 576, under the command of Justinian, and advanced to the relief of Theodosiopolis, the key of Armenia. Theodore, the Byzantine general, defended the fortress against the whole army of Khosrew. At the approach of Justinian the Persian king left the siege and advanced to meet the Greeks. The encounter took place near Melitene (in the district of Melitene in Armenia Minor). The Persians were routed, and many of them were drowned in their retreat across the Euphrates; twenty-four elephants, loaded with the treasures of Kliosrew and the spoil of his camp, were sent to Constantinople. Justinian then advanced as far as the Persian Gulf, and a peace was about to be concluded in 577; but Khosrew broke off the negociations on account of a victory which his general Tamchosroes (Tam-khosrew) unexpectedly obtained over Justinian by surprising him in Armenia. Tiberius now recalled Justinian, and appointed in his place Mauritius, who was afterwards emperor. ISIauritius restored the old Roman pre- caution of never passing the night except in a fortified camp; he advanced to meet the Persians, who had broken the truce of 575, and attacked the empire on the side of Mesopotamia (577). The Persians retired at the approach of Mauritius, who took up his winter quarters in Mesopotamia (577-78). On the 26th of September 578 Tiberius became sole emperor by the solemn abdication of Justin, who died on the 6th of October next. After the funeral of Justin, when the new emperor appeared in the Hippodrome, the people became impatient to see the empress. The widow of Justin, who was in the Hippodrome, expected to be pre- sented to the people as empress ; but she was soon undeceived by the sight of Anastasia, who suddenly appeared at the side of Tiberius. In revenge, Sophia formed a plot against Tiberius, and persuaded Justinian, the former commander in the Persian war, to put himself at the head of the conspiracy. Tiberius however was informed of this design. Justinian was arrested, and the emperor, by pardoning him, made him for ever his faithful friend. Sophia was deprived of her imperial pension and palaces, and she died in neglect and obscurity. A quarrel broke out between Eutychius, the patriarch, and Grego- rius, the apocrisiarius of Constantinople, who could not agree on the state of the soul after death. The Greeks were then the most disputa- tious people in the world about religious matters, and their disputes often led to serious trouble. The emperor accordingly undertook to d9 TIBERIUS ALEXANDER. TIBERIUS AB8IMARUS. «3 settle this dispute. Adhering to the opinion of Qregorius, ho con- vinced the patriarch that he was wrong, and he persuaded him to burn a book which ho had written on the corporeal nature of the soul after death. Khosrew died in 579, after a reign of forty-eight years. He had entered into negociations with the Greeks, but his successor, Hormisdas (Ormuz) broke them oflF and recommenced the war. Hormisdas was defeated by Mauritius and his lieutenant, Narses, a groat captain, who must not be confounded with Narses, the victor of the Ostro-Goths, They overran Persia in one campaign in 579, and in 580 they routed the army of Hormisdas in a bloody battle on the banks of the Euphrates, and took up their winter-quarters in Mesopotamia. At the same time the Greeks obtained great advantages in Africa. Qasmul, king of the Mauritani, or Berbers, had defeated and killed three Greek generals— Theodore, Theoctistes, and Amabilis; but in 680 he was defeated by the exarch Gennadius, and put to death. Tiberius was less fortunate in Europe, the Avars having surprised and taken the town of Sirmium. But in the following year (581) Mau- ritius destroyed the Persian army in the plain of Constantine, and tlieir general, Tam-Khosrew, lost his life. Mauritius had a triumph in Constantinople, and on the 5th of August he was created Caesar by Tiberius, who was then worn out by illness, and who had no male issue. After having given his daughter Constantina in marriage to Mauritius, Tiberius died on the 14th of August 582, and since the time of the great Theodosius no emperor's death caused regret so universal. It is a remarkable circumstance in the reign of this emperor, that he was always provided with money without oppressing the people by taxation ; and yet his liberality was so great that the people used to say that he had an inexhaustible treasure. But all these resources did not enable him to save Italy, which may bo accounted for thus : — During the invasions of Italy and other parts of the Koman empire by the barbarians, many rich men saved great quantities of gold and silver, which they carried to Constantinople, then the only safe place in Europe. This city being the centre of the arts, and the commerce and industry of the East being very extensive, even the money which fell into the hands of the barbarians gradually found its way into the Greek empire, where the barbarians purchased all those articles which they had not skill enough to fabricate them- selves. This view is corroborated by the fact, that notwithstanding the immense tribute which the Greek emperors often paid to the bar- barians, there was always a want of coin in the barbarian kingdoms. On the other hand, the Greeks having lost their martial habits, the emperors were obliged to recruit their armies among the barbarians. These people however w^re as ready to fight against the emperors as for them ; and it would have endangered the existence of the empire if too large a number had been engaged in its service. Thus Tiberius preferred bribing the Longobardian dukes to raising a large army of barbarians, who would probably have joined the Longobards as soon as they had got their pay. (Cedrenus ; Theophanes ; Theophylactus ; Zonaras ; Gregorius Turonensis; Paulus Diaconus; Gibbon, Decline and Fall; Le Beau, Ilistoire du Bas Empire.) _ TIBE'llIUS ALEXANDER, prefect of Egypt, was the son of Tibe- rius Alexander who was alabarcha of Alexandria, and the brother of Philo Judseus, the well-known writer. Tacitus calls him an Egyptian, but this only means that he was a native of Alexandria ; for he was a Jew, though he afterwards adopted paganism. Nero appointed him governor of Judaea, where he succeeded Cuspiua Fadus, and he made him a Roman eques. In the last campaign of Corbulo against the Parthians, Tiberius Alexander and Vinianus Annius, the son-in-law of Corbulo, were given as hostages to King Tiridates, who came to the Roman camp for the purpose of settling his differences with the Romans (a.d. 63). Tiberius Alexander was afterwards appointed prefect of Egypt, in which capacity he quelled a dangerous insurrec- tion of the Jews of Alexandria, who were jealous of the favour which Nero showed the Greek inhabitants of that town. The resistance of the Jews was so obstinate, that Tiberius was obliged to employ two legions and five thousand Libyan soldiers against them ; and it is said that more than fifty thousand Jews perished on this occasion. On the 1st of July, A.D. 69, Tiberius Alexander proclaimed Vespasian emperor, pursuant to a scheme which had been concerted by Vespasian, Titus, and Mucianus, the proconsul of Syria. In consequence of this event, the Ist of July 69 is regarded as the beginning of the reign of Ves- pasian, who showed great regard for his governor of Egypt. When Titus, the successor of Vespasian, was about to undertake the siege of Jerusalem, which resulted in its capture, he was accompanied by Tib^ius Alexander. (Josephus, Antiq. Jud. and De Bello Jtid,; Suetonius, Vespasianus ; Tacitus, Annal, xv. 28 ; Hist. i. 11 ; ii. 74, 79 ; the notes of Ernesti to Suetonius and Tacitus.) TIBERIUS, an Alexandrine grammarian, who probably lived in the 4th century of our era. Suidas (s. v. TtfitpLos), who calls him a philo- sopher and a sophist, ascribes to him a long list of rhetorical works, all of which are lost, with the exception of one, which formerly used to be called riepl tcov napa Aij/xoo-fleVet ffX'i]f'-<i-T<^v, and which is one of the best works of the kind that were produced at the time. The editio princeps of it, which is ascribed to Leo Allatius, appeared at Rome in 1643. The next edition is that of Gale, who incorporated . BIOG. DIV. VOL. VI. the work of Tiberius in hi« 'Rhetorei Select!,' 8vo, Oxford, 1676. A reprint of this collection of rhetoriciani was edited by J. F. Fiacher, 8vo, Leipzig, 1773. In all these editions the work of Tiberius contains only 22 short chapters, which treat on Schemata, that is, those forma of expression which are not the natural forms, but are adopted for ornament or use. In 1815 J. F. Boissonade published at London « new edition, in 8vo, from a Vatican manuscript, in which the work is called \lfp\ axnt^Tov f,r)ToptK(iu, and in which there are 26 chapter* more than had ever before been published ; and this second part of the work treats on the so-called * figurse elocutionis,' or the ornamental forms of elocution. This edition of Boissonade also contains a work of RufuB, entitled Ttxv'nh'^opiK-fi, the author of which has only become known through the Vatican manuscript containing the complete work of Tiberius ; in the editions of Gale and Fischer it was called the work of an anonymous writer. A few fragments of other works of Tiberius are preserved in the scholiast on Hermogenes, ii., pp. 886 and 401, edit. Aldus. (Groddeck, Initta Jlislorice Orcecorum LUerarice, ii 178; Wcster- mann, Geschichte der Griech. Beredtgamkeit, p. 251, &c.) TIBE'RIUS ABSI'MARUS became emperor of the East, m a.d. 698, under the following circumstances : — Leontius dethroned and banished the tyrant Justinian IL, and having assumed the imperial title in 695, continued the war with the Arabs in Africa. Notwithstanding the Greeks were assisted by the Berbers, they lost Carthage in 697 ; they reconquered it shortly afterwards, but in 698 the Arabs retook the town from the Greeks and entirely destroyed it. A powerful fleet, commi nded by the patrician John, was then off" Car- thage ; but although John entered the harbour with a division of bis fleet, and landed a body of troops, his measures had only a partial effect, and he was obliged to leave Carthago to her fate. The destruc- tion of this famous town was attributed by the Greek officers to the incompetency of John, and they were afraid to return to Constanti- nople without having prevented the ruin of Carthage. Absimaros, the commander of the Cibyrata), or the troops of the province of Cibyra, then the collective name of Caria and Lycia, turned the dis- content of the soldiei-s to his own profit. He persuaded hia men that the emperor would punish them severely for not having obtained some advantage over the Arabs, and that they ran the risk of suffering for the faults of their commander-in-chief. When the fleet was off Crete, a mutiny broke out. Qhe Cibyratae proclaimed Absimarus emperor, the rest of the fleet followed their example, and John was massacred. Absimarus having arrived at Constantinople, cast anchor in the bay of Ceras (now the Golden Horn), between this city and the suburb of Sycae. Leontius prepared a vigorous resistance ; but the courage of his soldiers and of the inhabitants was weakened by an epidemic disease, and at last Absimarus found his way into the town by bribing some sentinels. Absimarus assumed the name of Tiberius and was acknowledged emperor : his rival Leontius had his nose and his ears cut off, and was confined in a monastery. Tiberius Absimarus continued the war with the Arabs, and appointed his brother Heraclius commander-in-chiefl This experienced general conquered Syria in 699 and 700, and treated the Mohammedan inhabitants most barbarously: it is said that 200,000 of them lost their lives by the sword of the Greeks. This war continued during the years 701, 702, and 703 ; and, although the Greeks did not recover Carthage, they obtained many signal advan- tages. Tiberius Absimarus had great influence in Italy, where Popes Sergius and John VI. were continually harassed by John Platys, and afterwards by Theophylact, the Greek exarch of Ravenna. Tiberius Absimarus lost his crown by a sudden revolution. When Leontius dethroned Justinian II., this prince had his nose cut off, and was banished to tlio town of Cherson, in the present Crimea. Some years after, he fled to the khaghan, or khan, of the Khazars, who received him respectfully, and assigned for hia residence Phanagoria, once an opulent city, on the island of Tamatarcha. The khaghan, whose name was Busirus, gave him in marriage his sister Theodora ; but Tiberius Absimarus bribed the khan with a large sum of gold, and Justinian was only saved by the affection of Theodora, who discovered to him the treacherous design of her brother. After strangling with his own hands the two emissaries of the khaghan, Justinian rewarded the love of his wife by repudiating her and sending her back to her brother Busirus ; and he fled to Terbelis, or Terbellus, the king of the Bulgarians. He now formed the plan of recovering his throne, and he purchased the aid of Terbelis by promising him his daughter and a part of the imperial treasury. At the head of 15,000 horse, they set out for Constantinople. Tiberius Absimarus was dismayed by the sudden appearance of his rival, whose head had been promised by the khaghan, and of whose escape he was yet ignorant. Justinian had still some adherents in Constantinople, who introduced his troops into the city, by means of an aqueduct. Tiberius escaped from Constantinople, but he was seized at ApoUonia on the Pontus Euxinus (705), and Justinian ordered him, his brother Heraclius, and the deposed Leontius, who was still alive, to be dragged into the Hippodrome. Before their exe- cution, the two usurpers were led in chains to the throne, and forced to prostrate themselves before Justinian, who had sworn not to spare one of his enemies. Planting his feet on their necks, the tyrant watched the chariot-race for more than an hour, while the people 61 TIBULLUS, ALBIUS, TICKNOR, GEORGE.' 63 shouted out the words of the Psalmifit, " Thou shalt trample on the asp and basilisk, and on the lion and dragon shalt thou set thy foot." He then gave orders to behead Tiberius, Leontius, and Heraclius. Jus- tinian II. reigned till 711. The Greeks gave him the surname of Ebiuotmetus, that is, ' he whose nocie is cut ofif.' Tiberius Absimarus had two sons, Theodore and Constantine, who probably perished with their father. It is said however that Theodore, who is also called Theodosius, survived his father, and became bishop of Ephesus, and one of the leaders of the Iconoclasts; but this is doubtful. (Theophanes ; Cedrenus ; Zonaras ; Gibbon, Decline and Fall ; Le Beau. Ilistoire du Baa Empire.) TIBULLUS, A'LBIUS, lived in the time of Augustus, and was a friend and contemporary of Horace. He was of equestrian rank, and originally possessed considerable property, of which he lost the greater part (Tibull., L 1, 19, &c. ; iv. 1, 128, &c.), probably, as it is conjectured, in consequence of the assignments of lands among the veterans of Augustus ; and this supposition is rendered still more probable by the circumstance that Tibullus never celebrates the praises of Augus- tus, like the other poets of his time. Ho was not however reduced to absolute poverty ; the estate on which he resided at Pedum (Horace, ' Ep.,' i. 4), a town between Prseueste and Tibur, appears to have been his own, and to have descended to him from his ancestors. (Tibull., i. 10, 15, &c.) Here he passed the greater part of his time in the enjoyment of a quiet country-life, which had for him the greatest charms. He left it however to accompany his patron, Valerius Mes- salla, into Aquitania, and was present with him through the campaign, either in B.C. 28 or 27. (Tibull., i. 7, 9.) He afterwards set out with him to Asia, but was taken ill at Corcyra ; but that he died at Corcyra, as is stated by some modern writers, is only a conjecture, unsupported by any ancient authority, and is directly contradicted by what Ovid says. It appears from an epigram of Domitius Marsus (in Tibull., iv. 15), who lived in the ago of Augustus, that Tibullus died soon after Virgil ; and as Virgil died in B.C. 19, we may perhaps place the death of Tibullus in the following year, B.C. 18. It has been already men- tioned that Tibullus was the friend of Horace ; two poems have come down to us addressed to him by the latter (' Carm., i. 33 ; * Epist.,' L 4). Ovid too laments his death in a beautiful elegy, from which it appears that his mother and sister were present at his death (' Amor.,' iii. 9). It is diflficult to determine at what time Tibullus was born ; and we can but at best make some approximation to it. In the epigram of Domitius Marsus, already referred to, he is called juvenis, and Ovid deplores his untimely death. We must not however be misled by the expression juvenis into supposing that he was quite a young man, in our sense of the word, at the time of his death, since the ancients extended the meaning of juvenis to a time which we consider to be that of mature manhood. Several circumstances tend to show that he could not be much less than forty at his death. Ovid speaks of Tibullus as preceding Propertius, and of Propertius as preceding himself; and as Ovid was born B.C. 43, we must place the birth of Tibullus a few years at least before that time. Again, Horace in the first book of his Odes addressed Tibullus as an intimate friend, which hardly allows us to suppose that Tibullus was a mere youth at the time. If Bentley's supposition is correct, that the first book of the Odes was published about B.C. 30 or 28, Horace was then about 35, and Tibullus may have been a few years younger. Moreover he does not appear to have been a very young man when he accompanied Messalla into Aquitania in B.C. 28 or 27. We may therefore perhaps place his birth at about B.C. 57. There are indeed two lines in Tibullus (iii. 5, 17, 18), which expressly assign his birth to B.C. 43, the same year in which Ovid was born ; but these are, without doubt, an inter- polation derived from one of Ovid's poems ('Trist.,' iv. 10, 6). We have thirty-six poems of Tibullus, written, with one exception, in elegiac metre, and divided into four books. The first two books are admitted by all critics to have been written by Tibullus, but of the genuineness of the last two, considerable doubts have been raised. J. H. Voss and others attribute the third book to a poet of the name of Lygdamis, but the style and mode of treating the nubjects resemble the other elegies of Tibullus, and there do not appear suflScient reason for doubting that it is his composition. There are however stronger grounds for supposing the first poem in the fourth book, written in hexameters, not to be genuine. It difiera considerably in style and expression from the other poems, and is attributed by some writers to Sulpicia, who lived under Domitian, by others to a Sulpicia of the age of Augustus ; but we know nothing with certainty respecting its author. Of the other poems in this book, almost all bear traces of being the genuine works of Tibullus. The elegies of Tibullus are chiefly of an amatory kind. In the earlier period of his life Delia seems to have been his favourite, and afterwards Nemesis, and their names occur most frequently in hia poems. Several of his elegies are devoted more or less to celebrating the praises of his patron Messalla, but these are the least pleasing parts of his works, for he does not appear to have excelled in panegyric. Tibullus is placed by Quinctilian at the head of the Roman elegiac poets ('Inst. Orat.,' x. 1). His poems are distinguished by great ten- derness of feeling, which sometimes degenerates into effeminacy, but they at the eame time excite our warmest sympathies. He seems to have been of a melancholy temperament, and to have looked at things from a gloomy point of view ; hence we find the subject of death frequently introduced, and the enjoyment of the present interrupted by dark forebodings of the future. He constantly describes the pleasures of a country-life and the beauties of nature, for which he bad the most exquisite relish; and there is in these descriptions a naturalness and truthfulness which place him above his contemporary Pi'opertius. His style too is not of the artificial character which distinguishes the elegies of Propertius ; and his subjects are not, like the latter, mere imitations or translations of the Greek poets, but essentially original works. Tibullus was formerly edited together with Catullus and Proper- tius, the earlier editions of which are mentioned under Propertius. The principal sepai-ate editions are hy Brockhusius (Amst., 4to, 1708), Vulpius (Padua, 4to, 1749), Heyne (Leipz. 8vo, 1777, often reprinted, of which the fourth edition, containing the notes of Wunderlicb and Dissen, appeared in 1817-19, 2 vols. 8vo, Leipz.), J. H. Voss (Heidel- berg, 8vo, 1811), Bach, (Leipz., 8vo, 1819), Goldb^ry (Paris, 8vo, 182C), Lachmann (Berlin, 8vo, 1829), and Dissen (Gottingen, 2 vols. 8vo, 1835), of which the two last contain the best text. Tibullus has been translated into English by Dart (1720), and Grainger (1759). There are modem German translations by J. H. Voss (Tubingen, 1810), Giinther (Leipz., 1825), and Richter (Magde- burg, 1831). There are also French and Italian translations. Respecting the life of Tibullus and the Roman elegy in general, the reader may consult with advantage Gruppe'a ' Die Romische Elegie,' Leipzig, 1838. TICKELL, THOMAS, an English poet of unblemished mediocrity, was born in 1686, at Bridekirk in Cumberland. He was sent to Queen's College, Oxford, and he took his degree of Master of Arts in 1708. Two years afterwards he was chosen fellow of his college, and as he did not comply with the statutes by taking orders, he obtained a dispensation from the crown for holding his fellowship, till ho vacated it by marrying in 1726. His praises of Addison were so acceptable that they procured him the patronage of that writer, who "initiated him," says Johnson, " into public affairs." When the queen was negociating with France, Tickell published * The Prospect of Peace,' in which he raised hia voice to reclaim the nation from the pride of conquest to the pleasures of tranquillity. This, owing perhaps to Addison's friendly praises of it in ' The Spectator,' had a rapid sale, and six editions were speedily exhausted. On the arrival of King George I. Tickell wrote ' The Royal Progress,' which wa.i printed in the ' Spectator.' Johnson says of it that " it is neither high nor low," a very equivocal criticism, considering Johnson's habitual tastes. The translation of the first book of the 'Iliad' was the most im- portant thing in Tickell's poetical career, having been published in opposition to Pope's ; both appeared at the same time. Addison declared that the rival versions were both excellent, but that Tickell's was the best that was ever made. Strong suspicions of Addison him- self being the translator have been thrown out by Pope, Young, and Warburton. Dr. Johnson says, *'To compare the two translations would be tedious ; the palm is now universally given to Pope. But I think the first lines of Tickell's were rather to be preferred; and Pope seems since to have borrowed something from them in connection with his own." During the dispute on the Hanoverian succession Tickell assisted the royal cause with his ' Letter to Avignon,' of which five editions were sold. Addison now employed him in important public business, and when, in 1717, Addison himself rose to be secretary of state, he made Tickell under secretarj^ On Addison's death, Tickell published his works, to which he prefixed an elegy on the author, which Johnson pronounces to be equal for sublimity and elegance to any funeral poem in the English language. Considering that we have the ' Lycidas ' of Milton, this sounds oddly : on turning to this elegy, we are forced to admit, with Steele, that it is only " prose in rhyme," and occasionally very bad prose too. In 1725 Tickell was made secretary to the Lords Justices of Ireland, a place of honour in which he continued till hia death, on the 23rd April 1740. * TICKNOR, GEORGE, a distinguished American scholar and writer, was born on the 1st of August 1791, at Boston, Massachusetts, and was educated at Dartmouth College, New Hampshire, where he graduated in 1807. He entered upon the study of the law, and was called to the bar in 1813 ; but his' time and thoughts continued to be mainly given to literature, and in 1815 he finally abandoned the law and proceeded to Europe in order to fit himself for the more con- genial occupation to which he now fully devoted himself. After remaining a couple of years in the University of Gottingen he visited successively the cities of Paris, Rome, Madrid (where he spent several months in the year 1818), Lisbon, Edinburgh, and London. During the four years which he stayed in Europe Mr. Ticknor had zealously prosecuted his philological studies, his chief attention being given to the living languages of Europe, and he had made himself intimately acquainted with the literature of the middle ages. Among the many eminent literary men whose friendship he at this time acquired, were Southey and Sir Walter Scott, both of whom were delighted with his stores of old Spanish reading — Scott in writing to Southey in April 1819 (Lockhart'a 'Life,' c. xliv.), calls him a "wondrous 63 TICOZZI, STEFANO. TIECK, LUDWIO.$i
fellow for romantic lore and antiquarian research, considering bis
country." The fame of his attainments had during his absence
pecured his election to the chair of modern languages in Harvard
University, and on his return to America in 1819 he entered with
energy upon the duties of his office. His lectures uj^on the great
writers of Italy, France, Spain, and England excited, as Mr. Prescott
has testified, a remarkable amount of interest, and Mr. Ticknor's
labours are acknowledged to have been largely instrumental in stimu-
lating among his contemporaries the study of the modern langUHges
and literature of Europ&. Mr. Ticknor retained his professorship for
iifteeu year?. He then returned in 1835 with his family to Europe,
and spent there some three years in extending and verifying his in-
vestigations, and in collecting, with the assistance of Professor Pascual
do GiiyangOH of Madrid, rare and valuable Spanish books, of which he
succeeded in forming an almost unrivalled collection. Whilst largely
assisting other literary men and students, Mr. Ticknor had himself
published nothing more than an occasional essay, but he was now
concentrating his attention upon Spanish literature. "With a rare
amount of industry and intelligence he laboured on for years, and at
length in 1849 produced his ' History of Spanish Literature : with
Criticisms on the particular Works and Biographical Notices of Pro-
minent Writers,' 3 vols. 8vo. The work is by general consent the
most comijlete historj' of Spanish literature in any language, full,
minute, and precise in information, and eminently fair and candid in
spirit. The author appears in his researches almost to have exhausted
existing materials whether bibliographical or biographical — over-
looking nothing and neglecting nothing. However other students of
the poets and imaginative writers of Spain may differ from Mr.
Ticknor in his critical estimates of particular authors or books, all
willingly admit the immens'e benefit tbey derive from his labours,
and with entire unanimity his work has been accepted by European as
well as American scholars as the standard book of reference on the
history of Spanish literature. It has been translated into both the
Spanish and German languages.
TICO'ZZI, STE'I ANO, was born in 1762, in the Val Sassina, in the
province of Como. He studied at Milan, and afterwards at Pavia,
took priest's orders, and afterwards was appointed incumbent of a
country parish near Lecco, in his native province. When the French
invaded Lombardy in 1796, he and his brother Cesare Fi-ancesco, who
was an advocate, favoured the revolutionary movement; but when
the Austrians came back in 1799, Ticozzi was obliged to emigrate into
France, and his brother was seized and sent prisoner to Cattaro.
Ticozzi returned with the victorious French in the following year,
and was appointed to several political offices under the Italian repub-
lic, and in 1806 was' made sub-prefect of the department of the Piave
under Napoleon's administration. In 1810 he published some dis-
quisitions on monastic institutions : ' Degli Istituti Claustrali Dialoghi
Tre,' 8vo, Belluno. He lost his situation on the fall of Napoleon, and
retired to Milan, where he lived mainly by literary labour. He trans-
lated into Italian Sismondi's 'History of the Italian Republics,' Llorente's
'History of the Inquisition,' Agincourt's 'History of the Arts,' and
other works. In 1818 he published his 'Dizionario dei Pittori dal
Ilinnovamento delle Arti fino al 1800,' which he afterwards merged
in his larger work, ' Dizionario degli Architetti, Scultori, Pittori,
Intagliatori in rame e in pietra, Coniatori di Medaglie, Musaicisti,
Niellatori, Intarsiatori d'ogni Etd e d'ogni Nazione,' 4 vols. 8vo, Milan.
This is a really useful compilation, although not always exact about
dates. He also published — 1, ' Memorie Storiche,' 12 vols. 8vo,
Florence, being a series of historical tales taken from the history of
Italy in the Middle Ages ; 2, * Viaggi di Messer Francesco Novello da
Carrara, Signore di Padova, e di Taddea d'Este, sua consorte, a diverse
parti d'Europa,' 2 vols. 8vo, a work also illustrative of the same
period ; 3, a continuation of Corniani's biographical work, ' I Secoli
della Letteratura Italiana,' down to our own times, and also a con-
tinuation of Bottari's collection of letters concerning the arts : * Rac-
colta di Lettere sulla Pittura, Scultura, ed Architettura, scritti dai
pill celebri Personaggi dei Secoli xv., xvi., e xvii., continuata fino ad
nostri Giorni,' 8 vols. 8vo ; and likewise a continuation of Verri's
'History of Milan: ' 'Storia di Milano del Conte Pietro Verri, dai suoi
piii rimoti Tempi fino al 1525, continuata fino alia presente Eta,'
6 vols. 12mo, Milan, besides several dissertations upon various paint-
ings and other minor works. He left inedited and unfinished a Life
of Goreggio, and 'A Treatise on the Art of distinguishing Copies from
the Originals in Paintings.'
Ticozzi died in 1836. He married a grand-daughter of the historian
Gianuone, by whom he had several children.
TIDEMAN, PHILIP, was a native of Niirnberg, where he was
born in the year 1657. He studied first under a painter named
Nicholas Raes, with whom he remained eight years, and was distin-
guished by his diligent application to his art, in which he attained
great proficiency. Desiring however to improve his knowledge and
taste, he went to Amsterdam to study the capital works of the great
masters in the collections in that city.
Lairesse being at that time in great esteem at Amsterdam, Tideman
resolved to place himself under his direction ; and so gained the good
opinion of his teacher by his pleasing manners and his talents, that
Lairesse conceived a great affection for him, and not only gave him
the best instmction in the art, but employed him to assist in some
important works on which be wa» engaged. In executing thcec works
Tideman gave such evident proof of hii» abilitiea, that bo soon obtained
sufficient employment independent of Laire-ne.
His compositions of fabulous history and allegory indicate a lively
fancy, genius, and invention ; insomuch that in tbiu re«pect hi« denigna
have been recommended as models to succeeding artists. Two of bis
capital compositions were Venus complaining to Jupiter of Judo's
persecution of .^neas, and Juno applying to .£olus to destroy tbo
Trojan fleet. He died in 1715, at the age of fifty -eight, leaving a very
great number of sketclics and designs, which afford proofs both of bis
industry and the fertility of bis invention.
TIECK, CHRISTIAN FRIEDRICH, a celebrated sculptor, brother
of Ludwig Tieck, wiis bom in Berlin on the 14tb of August 1776.
Having studied awhile under Schadow, be in 1798 proceeded to Paris,
where ho became a pupil of David. In 1801 bo returned to Berlin,
and afterwards went to Weimar, then a great centre of literary and
artistic activity. Here be found in Gothe a warm and most valuable
friend and adviser, and whilst hero he not only assisted in the execu-
tion of the sculptural decorations of the new palace, but executed
busts of Gothe, Voss, and Wolff, besides many of members of princely
and noble families. In 1805 he went with his brother Ludwig to
Italy, and carefully studied the great works of art there, maintaining
at the same time by his numerous busts, &c., his manual dexterity.
Here he found friends and patrons in Madame de Stael, and the
crown-prince, afterwards King Ludwig, of Bavaria. For the former
he executed a rilievo for the family sepulchre at Coppet, and subse-
quently a life-size statue of Necker, and buets of herself, the Due de
Broglie, Augustus &;hlegel, and M. Rocca. For Ludwig of Bavaria
he executed at various times busts of Ludwig himself, Jacobi, Schelling,
Ludwig Tieck, Lessing, Erasmus, Grotius, Herder, Wallenstein, and
several others, chiefly for the Walhalla. On his second visit to Italy
(1812) he became acquainted with Rauch, and the two great sculptors
ever after remained fast friends. He returned in 1819 to Berlin, where
he established his atdlier, and was elected a member of the aoidemy.
During the remainder of his life he was employed upon, many of the
public works, and was a prominent actor in the artistic movements in
the Prussian capital. Among his productions were the friezes, the
sculptures in the pediment, and other external decorations of the
Theatre Royal, the gates, and the statue of the angel in the porch of
the Cathedral in Berlin ; a series of fifteen seated marble statues of
classical personages for the royal palace ; a bronze equestrian statue
of Frederick William at Ruppin, besides several monumental works
and numerous busts and rilievi. He was also during many years
extensively employed on the restoration of ancient works for the
Royal Museum, in which institution he was director of the depart-
ment of sculpture. He died at Berlin on the 14th of June 1851.
Tieck was not possessed of much imaginative power; be executed
some good statues and rilievi, but his chief strength lay in his memo-
rial busts, many of which display great elevation of style and admirable
chiselling. In his studio several eminent sculptors have been formed,
among whom perhaps the best known is Kiss, the sculptor of the
Amazon.. There are casts of some of Tieck's works in the Cijstal
Palace at Sydenham.
TIECK, LUDWIG, one of the most influential actors upon the
modern literature of Germany, was born in Berlin, on May 31, 1773.
At the universities of Halle, Gottingen, and Erlangen, he studied with
great ardour ; history and the poetical literature of both the ancients
and the moderns being his favourite pursuits. His poetical powers
developed themselves early, but they took a direction opposite to the
usual classical models, and exercised themselves on the feelings and
opinions of what may be termed the Christian chivalry or romance of
the Middle Ages, although his first efforts, ' Almansur,' a prose idyll,
in 1790, and 'Alia Moddin,' a prose play, in three acts, in 1790-1,
assumed an eastern locality. Both displayed great poetical ability, but
he did not attempt verse, except in a few short pieces introduced amid
the prose. In 1792 he produced the tragedy of 'Der Abschied' (The
Parting), also in prose, which, like most of his other dramatic pieces,
is more fitted for the closet than the stage. He probably himself
began to perceive that his true strength lay in narrative, and in the
same year he produced ' Das griine Band,' a mediaeval tale of consider-
able pathos, with great truth of characterisation and much interest;
and ' Abdallah,' an oriental tale, with little of oriental colouring, and
the study of English literature, particularly the drama, and the result
was, in 1793, a compressed translation, or rather paraphrase, of Ben
Jonson's ' Volpone,' in three acts, in which it is remarkable how care-
fully he has omitted all the more poetical passages which ornament
the original, and in which, for the scene where Volpone plays the
mountebank, he substitutes a satirical one between an Englishman and
a German author come to England for a few weeks to write volumes
on the character of the country and its inhabitants. To the same
period belongs also his novel of ' William Lovell,' of which the cha-
racters and scenery are intended to be English, but tbey have a very
foreign air, and the tone of the whole is more gloomy than most of
Tieck's productions. • a e
The six yetirs, from 1795 to 1800, both inclusive, was a period of
incessant activity. During it he travelled ; visited Jena, where be
formed an intimate friendship with the two Schl^els, ^ovall8, and
65
TIECK, LUDWia.
TIEDEMANN, DIETRICH.
66
Sohelliag; Weimar, where he became aoquomted with Herder; and
Hamburg, where he married the daughter of a clergytnaa named
Alberti. The iutercourse with the above-named literary celebrities had
much influence on hia future courne. While still adhering to the roman-
tic school, his productions embraced a wider field. He continued to
write tales, novels, tragedies, and comedies ; but in embodying nursery
tales, as in his * Blaubart,' a play in five acts, ' Die Sieben Weiber des
Blaubarts' (Seven Wives of Bluebeard), a talo, and the 'Leben utid Tod
des kleioen llothkiippchen' (Life and Death of Little Ked liiding Hood),
a tragedy in three acts, he united much of the simplicity of the old tradi-
to the story, and occasional passages of pathos or of humour. Occa-
sionally he took for his subject legends of a higher character, as in his
'Leben nnd Tod der heiligen Genoveva;' and in 1804, in 'Kaiser Octa-
vianus,' a work which had been long expected, and which his country-
men consider as one of the most successful of his romantic productions.
To this ho has prefixed a long prologue, in which various characters are
introduced to display the prosaic element, and a poet, to whom comes
Romance, a female, who describes herself as infusing joy throughout
the world, and says that her father is Faith, and Love her mother.
In this prologue, and in the following play, which is partly in
prose, is found the most favourable specimen of Tieck's versification.
It is not of the most careful construction ; and it is singular that
though his conceptions were highly poetical, the best examples of
them are found in his prose. This line was followed out in subse-
quent works, as in 'Fortuniit,' which however embodies a considerable
amount of good-humoured satire on the various conditions of the
existing state of society. Another class comprises, what are styled by
the Germans Art-Novels, to which belong 'Franz Sternbald's Wan-
derungCD,' ' Phantasien uber die Kuust,' and ' Herzensergiessungen
eines Kunatliebcnden Klosterbruders' (Heart-outpourings of an Art-
loving Monk), written in conjunction with his friend Wackenroder, in
all of which he displays a love and knowledge of the beautiful and
elevated in art, a contempt for the self-complacency of afi'ected cou-
noisseurship, and a manifestation of Roman Catholic feeling, to which
tinctive as a class, as his previous tales had much of a similar character,
were his ' Volksmiihrchen ' (Popular Legends), such as the history of
Heymon's Children, the Fair Magelone, Melusina, &c., legends which
are European, and the ' Denkwiirdige Geschichtschronik der Schild-
biirger' (Memorable History of the Simpletons), a sort of German
version of our Men of Gotham ; tales in prose, abounding in pleasant
fancy, interspersed with picturesque descriptions or strokes of broad
humour, and told with a simplicity and an apparent childish belief
in the wonders related that give an indescribable charm to the whole.
Upon yet another class he evidently bestowed more thought and
labour. In the dramas, for they assume that form, ' Der gestiefelter
Kater' (Puss in Boots); in 'Prinz Zerbino, oder die Reise nach
dem guten Geschmack' (Travels in search of Good Taste); 'Die ver-
kehrte Welt' (The World turned upside down); and 'Leben und
Thaten desKleinen Thomas, genanntDaumchen' (Tom Thumb); in all
of which he attacked with keen irony the low, material, anti-poetical
notions of poetry advocated by learned pedants, and defended by
implication, by example, and by occasional parodies on the classicists,
the theory of the romantic school. A key to 'Zerbino,' by one
thoroughly acquainted with the peculiarities of all the authors alluded
to in that drama, would possess much intereist for the English student.
These pieces, independent of their critical merits, have an interest of
their own from the wit and humour of the dialogue. Many of the
productions of this period, including most of those above-mentioned,
were subsequently published together, under the title of ' Phantasus,'
in a frame-work of a conversational party, to whom or by whom
they are related. An excellent translation of ' Don Quixote/ a very
good one of Ben Jonson's ' Epicccne, or the Silent Woman,' and a
remarkably successful one of Sbakspere's ' Tempest,' also belong to
this period.
In 1801-2, while residing in Dresden, he assisted F. Schlegel in
bringing.out the ' Musen-AJmanach,' to which he contributed some of
his tales. He then lived for a time at Berlin, and next at Ziebingeu
near Frankfurt-on-the-Oder, seeming to enjoy a poetical leisure,
during which he produced nothing but ' Kaiser Octavianus ' of which
we have already spoken, in 1804 ; and in the same year he made a
journey to Italy, returning from thence in 1806 to Munich, where he
had tlie first attack of gout, from which he was ever after an extreme
sufTtrer. This attack was so violent, that he produced little for
several years. He occupied himf elf, when able, in revising and adding
to his previous works, publishing the 'Phantasus' as above stated,
and a collection of his poems; in studying and collecting the early
poetry of his own country, of which in 1803 ho had published 'Minne-
lieder aus dem Schwabiscben Zeitalter' ( Love Songs of the Swabian
period), and in 1815 * Ulrioh's von Lichtenstein Frauendienst ' ( Worth
of Woman) ; and in extending his acquaintance with the English
drama. In 1812 he published the ' Alt-englisches Theater,' containing
translations of the old King John, the Pindar of Wakefield,
Pericles, Locrine, the Merry Devil of Edmonton, and the old
Lear, all of which he contends are the genuine, though chiefly early,
productions of Shakspere. In 1817 he published two volumes of
specimens of the early German drama, and in the same year visited
England for the purpose of acquainting himself with the literature
connected with the drama which he could not procure in Germany.
He laboured diligently ; the treasures of the British Museum as well
as those of many private collections were opened to him ; and it is
probable that no foreigner ever attained so wide and so exact an
acquaintance as Tieok with the English literature of the great Eli/.a-
bethan period, or so just an appreciation of Shakspere, although his
enthusiasm has led him .to the discovery of beauties hidden from
Englishmen in the apocryphal or rejected works attributed to Shak-
spere, in the genuineness of nearly all of which he is a stedfast believer,
but of which his countryman and follower Ulrici has formed a more
and for some time his literary publications were chiefly novels and tales
for the pocket-books and similar [annuals. In 1823 he published the
first volume of ' Shiikspeare's Vorschule' containing translations of
Green's ' Friar Bacon,' 'Arden of Feversham,' of which he has doubts
whether it is a production of Green's or an early work of Skakspere,
and Hey wood's ' Lancashire Witches ;' this was followed by a second
volume in 1829 containing ' Fair Em,' ' The second Maid's Tragedy,'
by MuBsingen, translated from one of the three manuscript plays
saved fi-om the fire by Warburton the herald, and ' The Birth of
Merlin :' the first he considers to be more probably an early effort of
Sbakspere's than of any of the other names to which it has been
assigned, grounding his opinion of this and other of the doubtful
plays on the belief that Shakspere commenced writing for the stage
many years earlier than had at that time been admitted; a belief
which the investigations of Mr. C. Knight in his ' Pictorial Shakspere '
has shown to be very probable, though not leading always to the con-
clusions at which Tieck has arrived regarding the particular plays. In
1828 he published his ' Dramaturgische Bliitter,' chiefly written in
1817, a collection of reviews or criticisms of modern German plays,
including notices of Schiller's ' Piccolomini,' and * Wallenstein's Tod;'
Qothe's ' Jery und Batelei,' and ' Clavigo ; ' and Sbakspere's ' Romeo
and Juliet,' 'Lear,' 'Henry VIII.,' ' Macbeth,' and ' Hamlet ; ' all con-
taining much genial criticism, with a delicate and true apprehension of
their poetical feeling and harmony ; with notices of the acting of Kcmble
and Kean ; and Appendices on the German and English stage. About
the same time he took an active part in the continuation and
completion of the translation of Sbakspere's acknowledged plays,
which had been begun by Schlegel, and of which the first volume
appeared in 1825. The merits of this translation, of which many
were entirely from Lis own hands, and all were subjected to his
revision, are universally acknowledged. Less literal, but more spirited
and equally true to the sense of the author, than the previous trans-
lation by the Vosses, they are illustrated by a number of notes which
display a vast amount of reading, and many ingenious conjectures as
to various disputed readings, and they now form the recognised text
of Sbakspere's plays iu Germany. Tne work was completed in 1829.
But his labours were not confined to this work, he continued to write
tales for periodical publications, and in 1828 he produced his novel
of ' Dichtersleben,' ( Life of a Poet ) in which Shakspere and several
of his contemporaries are introduced, and in which the death of
Marlow is vividly described. In 1829 he published 'Der Tod des
Dichters,' (the Poet's Death) in which the unhappy fate of Camoens
is pathetically related. In 1826 he also produced one of his most
picturesque narratives, ' Der Aufruhr in den Cevennes,' in which the
insurrection in the Cevennes is graphically told, but unfortunately
was left incomplete. While residing at Dresden his evening circles
became celebrated, at which his readings and the relation of his
tales formed a principal charm, and which were attended by all
the literary celebrities who were in the vicinity and could gain admis-
sion. In 1836 and 1840 he published his two latest novels — 'Der
Tiscblermeister ' ( The Cabinet-maker) and ' Victoria Accorombona,'
both of which are very inferior to most of his previous works of a
similar character. He also took an active part in the management of
the Dresden theatres. In 1840, on the accession of Friedrich Wilhelm
IV. to the throne of Prussia, Tieck was invited to Berlin, an invitation
which he accepted. He was then created a privy-councillor, and passed
the remainder of his life partly in Berlin and partly at Potsdam, occu-
pied cbiefly with some theatrical productions, and in revising and
correcting his works, which were published iu 20 volumes at Berlin
between 1828 and 1846. At various times he also edited 'Novalis's
Schriften,' in conjunction with Friedrich Schlegel, 1802 ; Heinrich von
Kleist's ' Nachgelassenen Schriften' (Posthumous Works, 1826;
Solger's 'Nachlasa und Brief wechsel ' (Remains and Correspondence)
with Friedrich von Raumer, 1826 ; and Reiuhard Lena's ' Gesam-
melte Schriften,' (Collected Works) in 1828. After sufiering for some
years from continued illness, borne- with wonderful patience and
cheerfulness, he died at Berlin, April 28, 1853, leaving a name which
may rank with the highest in his native country, and which English-
men may reverence as that which in Germany is most connected with
the popularising of the fame of the great dramatic poet of England.
TlEDEMANJSr, DIETRICH, a German philosopher, was born on
the 3rd of April 1748, at Bremervorde, near Bremen, where his father
was burgomaster. He received his earliest education at home, and as
he was scarcely allowed to have any intercourse with other children,
his leisure hours were spent in reading. His father sent him in 1763
to Ytrden, where he was chiefly engaged in acquiring a knowledge of
57
TIEDEMANN, DIETRICH.
TIEDGB, CHRISTOPH AUGUST.
6S
the ancient and some modern languages. After a stay of two ycare
he entered the Athenrcum of Bremen. The system of education and
the distinguished masters of this institution had great InQuence on
young Tiedemann. It was here that he first conceived a love for
philosophy and its history, and he began his philosophical studies by
reading the works of Descartes, Locke, Helvetius, and Malebranche.
After spending eighteen months at Bremen, he entered the University
of Gottingen, with the intention of studying theology pursuant to his
father's wish ; but he continued the study of classical literature,
mathematics, and philosophy. The study of philosophy raised in his
mind strong doubts respecting certain main points of the Christian
religion, which he was unable to overcome, and this led him to aban-
don the study of theology. He now tried jurisprudence, but not-
withstanding the entreaties of hft father to devote himself to some
profession, he abandoned the study of the law also, and at last deter-
mined to follow his own inclinations, and to give himself up entirely
to philosophy and its history. His father, dissatisfied with his son's
conduct, refused to send him further means of subsistence. After
having spent two years and a half at Gottingen, Professor Eyring
proposed to him to take the place of tutor in a nobleman's family
in Livonia, which Tiedemann accepted very reluctantly. In 1769 he
entered his new situation, in which he remained four years, although
he was shut out from all means of prosecuting his own studies, and
had to devote almost all his time to his pupils. Nevertheless, he
found time to write a little work on the origin of language, a favourite
topic with the philosophers of that time. It was published under the
title, * Versuch einer Erkliirung des Ursprungs der Sprache,' 8vo, Riga,
1772. In the year following he returned to his native place, and after
having spent a year there in studying various subjects which he had
neglected in Livonia, he again went to Gottingen. His friend Meiners,
who was now a professor in the university, introduced him to Heyne,
wljo immediately made him a member of the philological seminary.
The small income derived from this institution, and from private
instruction, together with what he got by writing, enabled him to live
in independence. His work on the Stoic philosophy appeared under
the title of 'System der Stoischeri Philosophic,' 8vo, Leipzig, 1776.
with a preface by Heyne, who had recommended the publication. In
this year Heyne was applied to in order to recommend a competent
person for the professorship of ancient literature at the Carolinum in
Cassel. Heyne recommended Tiedemann, and accepted the place for
him without telling him of it. Tiedemann was delighted with the
place, as it did not occupy too much of his time, and put him in con-
nection with some of the most distinguished men in Germany. The
study of philosophy .and its histoi-y was now prosecuted with fresh
zeal and vigour. The philosophical views which he had imbibed from
the authors whom he had most studied tended towards materialism ;
but his friend Tetens vigorously counteracted them, and at length
succeeded in turning his mind in a different direction. In the year
1786, when the Carolinum was brpken up, Tiedemann was transferred
with the other professors to Marburg. Here he lectured at different
times on logic, metaphysics, the law of nature, on moral philosophy,
psychology, universal history, history of philosophy, and sometimes
also on some classical Greek writer. His lectures were very popular,
and his kind disposition made his hearers look upon him moi"e as a
friend than as a master. Sometimes, especially during the last period
of his life, he did not conduct himself with the calmness and dignity
of a philosopher in combating the philosophy of Kant, to which he
was opposed. He died in tiie midst of literary undertakings, after a
short illness, on the 24th of May 1803.
Tiedemann was beloved and esteemed by all who knew him. His
life was spent in intellectual occupations and bodily exercise, of which
he was very fond. His striking qualities were great self-control,
cheerfulness, and a total absence of all pretension to hterary supe-
riority, although his works were extremely popular. Besides the works
already mentioned, the following deserve notice : — * Untersuchungen
iiber den Menscheu,' 3 vols. 8vo, Leipzig, 1777, &c. ; ' Griechenlands
erste Philosophen, oder Leben und Systeme des Orpheus, Pherecydes,
Thales, und Pythagoras,' 8vo, Leipzig, 1780 ; * Hermes Trismegists
Poemander, oder von der gottlichen Macht und Weishiet,' 8vo, Berlin
and Stettin, 1781. This work is a translation from the Greek of
Hermes Trismegistus. 'Geist der Speculativen Philosophie,' 6 vols.
8vo, Marburg, 1791-97. This work is a history of philosophy from the
time of Thales down to Leibnitz and Christian Wolff, and is still
useful for the materials which it contains. In style and arrangement
it is deficient, and the author did not possess that critical and profound
knowledge of philosophy which would have enabled him to perceive
the organic connection and the necessary succession of the various
philosophical systems. ' Thtaetet, oder iiber das menschliche Wissen,'
8vo, Frankfurt, 1794; 'Handbucli der Psychologic.' This work was
edited after the author's death (8vo, Leipzig, 1804) by L. Wachler,
who has prefixed to it a biographical memoir of Tiedemann. Besides
these greater works, Tiedemann wrote numerous smaller treatises and
made many translations from the French : he also contributed papers
to several periodicals. He is the author of some Latin dissertations,
among which we may mention three programs : ' De Antiquis quibus-
dam Musei Fridericiani Simulacris,' 4to, Cassel, 1778-80 ; 'Dialogorum
Platonis Argumenta exposita et illustrata,' 8vo, Bipont, 1786 ; 'Disser-
tatio de Qucestione : quse fuerit artium magicarum origo, quomodo
ilia) ab Asito populis arl Gracos atquo Romanos et ab his ad csetenw
gentes sint propagata),' &c., 4to, Marburg, 1787.
(L. Wachler'a Memoir of Tiedemann, in his Ilandbuch der Ptycho-
logie; Creuzer, Memoria Diterici Tiedemanni, 4to, Marburg, 1803;
and JordcD, Lexikon Beutscher Dichler und ProsaUlen. voL v'
pp. 70-86.) ■*
♦ TIEDEMANN, FRIEDRICH, a celebrated German anatomist, was
the sou of the celebrated philosophical writer, Dietrich Tiedemann,
and was born at Cassel on the 23rd of August 1781. He received hit
early education at the gymnasium at Marburg, where he also com-
menced the study of anatomy and physiology. He subsequently
studied in the hospitals of Bamberg and Wiirzburg, and took his
degree in 1804. At this time he took up the study of phrenplogy,
and pursued it with great, earnestness. He visited Frankfurt, and
made the friendship of the celebrated Sommering. He also attended
a course of Schelling's lectures on natural philosophy at Wiirzburg,
and afterwards repaired to Paris. In 1805 he was appointed professor
of anatomy and physiology at Landshut. Here he published his first
work on ' Zoology,' the first volume of which appeared in 1808 and the
third in 1810. In 1809 he aleo published a work on the 'Anatomy ot
the Heart of Fishes,' which was the result of a journey in Italy and the
Tyrol. In 1811 he published his * Anatomy of the Flying Lizard or
Dragon.' In 1813 appeared an essay on the * Anatomy of Headless
Monsters.' He obtained the prize offered by the Institute of France
in 1811 for the best essay on the ' Structure and Relations of the
Radiate Animals.' In order to qualify himself for this work he made
a journey to the coas"-. of the Adriatic. This essay was published in
1820. In 1816 he was called to the chair of comparative anatomy and
zoology at Heidelberg. In this position he not only gained a great
reputation as a teacher, but published a large number of works upon
human anatomy and zoology, which have contributed greatly to the
advancement of those sciences during the present century. Amongst
these the best known are his two great illustrated anatomical works
on the * Nerves of the Uterus ' and the ' Arteries of the B^uman Body.'
These were published in folio in 1822. In the same year he also pub-
lished * Plates of the Brain of Monkeys.' In 1830 he commenced the
publication of a ' Physiology of Man,' which was finished in 1836. As
a physiologist he devoted great attention to the physiology of digestion,
and in conjunction with Leopold Gmelin, professor of chemistry in
Heidelberg, he made many original researches and observations on this
subject. In conjunction with L. C. Treviranus he edited five volumes
of the 'Zeitschrift fiir Physiologie.' He has also published numerous
papers in journals, &c., both on anatomy and zoology, of great value.
In 1849 he retired from his chair at Heidelberg on the occasion of the
death of his eldest son, who was commander of the castle of Rastadt,
and who was condemned to death for having sided with the revolu-
tionary party.
TIEDGE, CHRISTOPH AUGUST, 'The Nestor of German
Poetry,' and one who has now taken his place among the German
classics, was born at Gardelegen in Altmark, December 14th 1752.
His early prospects in life were by no means flattering, for the death
of his father (Conrector at the Magdeburg gymnasium), in 1772, left
him and a family of young children in a very destitute situation. He
completed however his legal studies at Halle; but notwithstanding
the favourable opinion his talents had acquired for him, he soon
abandoned the profession for which he had prepared himself, and in
1776, accepted the situation of private teacher in the Arnstadt family
at Elrich in Hohenstein. The choice he had made proved a fortunate
one, since it eventually led to connections and friendships that proved
adopted was an intimacy with Gokingk, Gleim, and other literary
persons of that day, including the Baroness von der Recke. The
friendships thus formed, laid the foundation of the prosperous and
unrufiled tenour of his after-life. On quitting Elrich he was invited
by Gleim to reside with him at Halberstadt, which he continued to do
until 1792, when he became private secretary to Domherr von Stedern;
and though he died in the following year, Tiedge remained in the
family upon the same footing during the life of Madame von Stedern,
who, at her death, in 1799, secured to him a handsome competency.
Being thus placed perfectly at ease in his circumstances, he travelled
through the north of Germany, and visited Berlin, where it was hia
good fortune again to meet with Madame von der Recke, and the
intimacy thus resumed continued for life. Though not in accordance
Viith. the ordinary usages of society, it was as entirely free from the
slightest suspicion of impropriety, as was the similar domestication of
Cowper with Mrs. Unwin. This union, of a kind so exceedingly rare
that no name has been invented for it, was that of two noble and pure
minds, congenial in their tastes, and equally inspired with a feeling
for poetry and those pursuits which, while they refine, also elevate our
nature. The author of 'Urania' was as well shielded from scandal as
was the author of the * Task ; ' for although very different in form,
the first-mentioned poem is, like the other, deeply tinged by religious
sentiment; and its merits were more immediately recognised, for it
went through several editions within a very short time from its first
appearance in 1801.
In 1804 Tiedge and his female friend visited Italy, where they
remained about two years ; and of this journey we have an account
from the pen of Madame von der Recke herself, 'Tagebuch einer
M
TIEPOLO, GIOVANNI BATTISTA.
TIGRANES.
60
B«w<>,' tie, A ToU. 8vo, with a preface and notes by Bottiger, which,
betidea being very superior to the general class of tour-books, affords
•TideDCO of ber being a zealous though candid Protestant, and a
der Kecke made Berlin, and afterwards (1819) Dresden, her chief place
of residence, paaaing the summer months at Teplitz or Carlsbad. The
only change Tiedge henceforth experienced was that occasioned by the
loss of his companion and benefactress, for she had taken care that
her death (1833) should cause no change whatever in his outward
circumstances, not even that of his residence ; as she directed that her
establishment should be kept up for him precisely as before, and that
be should continue to enjoy the luxuries and comforts he had bo long
been accustomed to. Nor was her anxious solicitude for her friend's
welfare useless; for so pre eminently was Tiedge favoured beyond the
ordinary lot, that he not only attained an unusual age, but remained
nearly free from all infirmities of cither body or mind. In hid eighty-
ninth year, says one who appears to have known him personally, he
did not seem to be much more than sixty : the only alteration in him
was, that for some years be could not take exercise on foot, or stir out
except in a carriage or a wheel-chair. Even but a week before his
death (March 8th 1841) he was at the birth-day fdte of one of his
friends.
Soon after his death, his ' Life and Literary Remains ' were given to
the world by Dr. K. Falkenstein, in 4 vols. ; and a complete edition
of his works has been published in 10 vols. 8vo. After his ' Urania,'
his moat original production is perhaps his ' Wandenmgen durch den
Markt des Lebens,' 1836, which, like the other, may be said to be
lyric-didactic, and similar in tendency, though of a less decidedly
religious character, the seriousness of its moral precepts being relieved
by the tone of playful irony which pervades many parts of the poem.
Hi* principal other productions are his ' Poetical Epistles,' his
' Elegies,' and his ' Frauenspiegel,' all of which have contributed to
his reputation. The esteem in which the poet of ' Urania ' is held is
proved by the fact that, in honour of his memory, a ' Tiedge Verein,'
or Tiedge Institution, was after his death established at Dresden, one
object of which is to give a literary prize every five years, and another
to make some provision in their declining years for meritorious writers
who may have fallen into adversity in consequence of age and
infirmities.
TIE'POLO, GIOVANNI BATTISTA, a celebrated Italian painter
of the 18th century, was born of a good family at Venice in 1693.
Ticpolo, says Lanzi, was the last of the Venetians who acquired a
European fame; celebrated in Italy, in Germany, and in Spain. He
studied as a boy under Gregorio Lazzarini, painted at first in his
manner, then imitated the style of Piazzetta, but attached himself
eventually to that of Paul Veronese. Already at the age of sixteen
he was known even out of Venice, and when still young he received
invitations from various Italian cities to decoi-ate their churches and
their public buildings. His works in the north of Italy, both in oil
and in fresco, are numerous : one of his first works of note was the
Shipwreck of San Satiro, in the church of St. Ambrose, at Milan : he
excelled chiefly in fresco, and his colouring and the folds of his
draperies bear great resemblance to those of Paul Veronese. In Ger-
many also Tiepolo executed several works : at Wiirzburg he painted
the staircase and the saloon of the bishop's palace and two altar-pieces.
He was afterwards invited by Charles III. to Spain, where, in Madrid,
be painted the ceiling of the saloon in the new palace of the king, and
the hall of the royal guard, by which he is said to have excited the
jealousy of Mengs : he executed also the chief altar-piece in oil for the
convent church of St Paschal, at Aranjuez. He died in Madrid in
1769 or 1770.
Tiepolo's style was slight and brilliant, yet his colouring was not
glaring : the effect of his paintings was not produced by a recourse to
bright colours, b»it by a judicious contrast of tints : his drawing was
however feeble, thout,'h this weakness was nearly concealed by the
gracefulness of his attitudes. One of his best pictures in oil is the
Martyrdom of St Agathia, in the church of St Antonio, at Padua.
He etched several plates in a very free and spirited manner. He left
two sons, Giovanni Domenico and Lorenzo, who were both painters :
the elder etched some of his father's designs.
TIGHE, MUa MARY, was bom in 1773, the daughter of the Rev.
William Blachford, by Theodoaia, the daughter of William Tighe of
Bosanna, in Wicklow county, Ireland. She married in 1793 her rela-
tive Henry Tighe of Woodstock, in the county of Wicklow. In 1805
she printed for private circulation her poem of 'Psyche,' a work
founde<l on the story of Cupid and Psyche, as told in the 'Golden
Ass' of Apuleius. The poem is remarkable for the beauty of its
descriptions, the tenderness and purity of its sentiments, the ingenious
manner in which the writer has completed the story, the poetical
imagery, and the musical flow of the versification, which is in the Spen-
serian stanza, managed *ith great skill. After six years of continued
ill-health she died on March 24, 1810, and in 1811 ' Psyche' was pub-
lished with a collection of miscellaneous poems, many of them written
during her illness, and breathing a deep religious feeling. All of them
show the same virtuous tendencies as are developed in her principal
work, but they do not on the whole display the same amount of
poetic power.
TIQRA'NES, king of Armenia, the ally of Mithridates the Great,
who gave him his daughter Cleopatra in marriage. He was master of
the largo tract between Egypt iu the south-west, and the Caspian Sea
in the north-east, which was bounded by Assyria and Media on the
east, and by the kingdoms of Pontus and Cappadocia on the west and
north-west. The earlier history of Tigranes is little known; Strabo
(p. 532, Cas.) and Justin (xxviii. 3) state that ho was sent in his youth
as a hostage to the king of the Parthians, who afterwards restored
him to liberty. He conquered Gordyene and Mesopotamia, and the
Syrians chose him for their king in B.C. 84, or, according to Appian
(' De Reb. Syr.,' 70), in B.C. 80. Before B.C. 74 he concluded au
alliance with Mithridates, who was then about to begin his third war
with the Romans. The conditions of this alliance were, that Mith-
ridates should be master of the countiies which they hoped to
conquer, and that Tigranes should have the inhabitants and all the
moveable property that he could carry off. Plutarch states (' LucuUus,'
p. 509, Xyland.) that the army of Tigranes was composed of 2(50,000
men, — 20,000 archers, 55,000 horse, 150,000 foot, and 35,000 pioneers
and train, — and that Arabs and warlike Albani from the Caucasus
abounded in the Armenian camp. The campaign was opened in
B.C. 74. Cappadocia and Bithynia were conquered, and Mithridates
laid siege to Cyzicus in Bithynia, but LucuUus came to relieve it, and
after various reverses Mithridates was compelled to fly to Tigranes
(B.C. 69). The conduct of the Armenian king had been insincere
during these events, and the Romans being now victorious, he not
only refused to receive his father-in-law, but set a prize of a hundred
son, who was likewise called Tigranes, to rebel against his father and
to join the Romans. Mithridates nevertheless succeeded in pacifying
his son-in-law, and they joined their armies to meet LucuUus, who had
crossed the Euphrates and the Tigris, and had laid siege to Tigrano-
certa, the new capital of the Armenian kingdom. A battle ensued
near this town, in which Tigranes was completely defeated (6th
October, B.C. 69), and his capital fell into the hands of the Romans.
Tigranes and Mithridates having entered into negociation with Phraatea
HI., king of the Parthians, for the purpose of drawing him into their
alliance, LucuUus, who had now carried his conquest in Armenia as
far as Artaxata on the upper part of the Araxes, marched to Mesopo-
tamia to attack the Parthians. But a mutiny of his soldiers compelled
him to retreat to Cappadocia, where they dispersed, as it seems, by
the instigation of Pompey, who aimed at the supreme command in
the war (B.C. 67). The Romans lost Cappadocia, and Tigranes carried
off a great number of the inhabitants of this province, as well aa of
Cilicia and Galatia. Pompey entered Asia Minor in B.C. 66, and in the
same year he defeated Mithridates in a great battle on the Euphrates.
Mithridates, having experieuced the faithless character of his son-in-
law, fled to Phanagoria in the island of Taman, while Tigranes
humiliated himself before the Romans, then encamped in the neigh-
bourhood of Artaxata. He went to the tent of Pompey, and, kneeling
before his victorious enemy, took off his royal diadem, which Pompey
however would not accept. The policy of the Romans reqmred an
independent kingdom between their dominions and the dangerous
power of the Parthians. Tigranes therefore was reinstated in Armenia,
except the districts of Gordyene and that of Sophene, or the western-
most part of Armenia Magna, which he was obliged to cede to his
rebellious son Tigranes, then an ally of the Romans. Besides these
districts, he ceded to the Romans his kingdom of Syria, including
Phoenicia and all his conquests in Cilicia, Galatia, and Cappadocia ; he
paid six thousand talents, and he gave half a mina to each Roman
soldier, ten minaj to each centurion, and sixty minse, or one talent, to
each tribune. (Plutarch, ' LucuUus,' p. 637, Xyland. ; comp. Appian,
'De BeUo Mithrid.,' c. 104.) It seems that after this humiliation
Tigranes led an obtcure and tranquil life, for his name disappears from
history, and the year of his death is unknown. His successor was
Artavasdes. [Mithkidates ; Pompeids; Lucullus.]
(Valerius Maximus, v. 1, 9 ; Velleius Paterculus, iL 33, 1, and c.
37; Cicero, Pro Lege Manilia; Woltersdorf, Commentatio Vilain
Mithridalis M.per annos diyestam siatens, Goettingaj, 1812.)
Coin of Tigranes.
British Museum. Actual size. Silver, Weight 245 J grains.
TIGRA'NES, prince of Armenia and lord of Sophene, was the son
of Tigranes, king of Armenia. During the last war between the
Romans and Mithridates aided by his ally king Tigranes, prince
Tigranes forsook his father and went over to the Romans. \Vhen his
father humUiated himself before Pompey, he sat by the side of tho
Roman general, but he did not rise before his father, nor did he show
61
TILLEMONT, SEBASTIEN-LENAIN-DE.
TILLEMONT, SEBASTIEN-LENAIN-DE.
62
him tho slightest degree of filial respect. Having been created lord of
Sophene and Gordyene, he refused to surrender the treasures of
Sophene to Pompey, who suspected him of being in secret communi-
cation with Phraates, the king of the Parthians, whose daughter he
had married. Tigranes also became suspected of having formed a
l)Ian for seizing or putting to death his father, and accordingly he was
arrested by order of Pompey, who sent him to Rome. He figured in
the triumph of Pompey.
Appian (' De Bello Mithrid.,' c. 105 and 117) states that Tigranes
was afterwards put to death in his prison. [Tigranes.]
TILLEMONT, SEBASTIEN-LENAIN-DE, an historical writer of
considerable note, was born at Paris on the 30th of November 1637.
He was the son of Jean Lenain, master of the requests, and his wife
Marie le Ragois. His excellence of character was manifested very
early; and even as a child he always abstained from those mischievous
pranks in which children commonly indulge. When between nine and
ten years of age he was pluced under the charge of the members of the
religious society then established in the vacant abbey of Port Royal,
and under these instructors he devoted himself to the exercises of
learning and piety. His favourite author, while at school, was Livy :
a preference indicative of the bias of his mind to historical studies.
He studied logic and ecclesiastical history under Nicole ; and his
questions on the latter subject at once evinced the earnestness with
which be pursued it, and put the knowledge of his instructor to a
severe test. He studied the theology of Estius, from which, when
about eighteen years of age, he turned with much satisfaction to the
Btudy of the Scriptures themselves, and of the Fathers ; and while
thus engaged he began to collect the historical notices of the Apostles
and Apostolical Fathers, and to arrange them after the plan of Usher's
♦ Annales.'
The tenderness of his conscience, and the strictness of his notions of
duty, kept him for some time undetermined as to the choice of a pro-
fession. At the age of twenty-three he entered the Episcopal seminary
of Beauvais, where he was received with such respect from his reputa-
tion for historical knowledge, that fearing it might be a snare to
his humility, he contemplated leaving it, but was persuaded to remain
by Isaac de Sacy, one of the members of the Society of Port Royal,
whom he had chosen for his spiritual guide. He remained three or
four years iu the seminary of Beauvais, and then spent five or six
with Godefroi Hermant, canon of that city. He was much respected
and beloved by the bishop of Beauvais, Choart de Buzanval, and
fearing still' that this estimation would make him vain, he suddenly
left the place and returned to Pari?, where he remained two years
with his intimate friend and school-fellow at Port Royal, Thomas du
Fosse ; but not finding in Paris that retirement which he desired, he
withdrew to St. Lambert, a country parish in the neighbourhood of
that city.
In September 1672, at the mature age of thirty-five, he became sub-
deacon, and fifteen months after deacon. The following extract from
a letter addressed to his brother (Pierre Lenain, then or afterwards
subprior of La Trappe) evinces at once his pifty and his humility.
After stating that it was at the desire of Isaac de Sacy, his friend and
guide, that he had become subdeacon and was about to take on him
the deaconship, he goes on, " I assure you, my dearest brother, that it
is with great agitation and fear that I have resolved to comply with
his wish, for I feel that I am far from those dispositions which I
myself see to be necessary for entering upon this office ; and above all,
I am obliged to confess that I have profited little from the grace
which I might have received from the order and duties of the sub-
deaconship. But on the other hand I could not resist one whom I
believe I ought to obey in evei'y thing, and who, I am well aware, has
the greatest love for me. I beg of you then, my dearest brother, to
pray to God for me, and to ask him either to cause M. de Sacy to see
things in a different light, or to give to me such dispositions that the
advice of my friend may be for my salvation, and not for my con-
demnation."
In 1676 he received priest's orders, at the further persuasion of De
Sacy, who contemplated making him his successor in the office of
spiritual director of the Bernardine nuns, now re- established in their
original seat, the abbey of Port Royal, to the immediate neighbour-
hood of which establishment Tillemont removed. He was however,
iu 1679, obliged to remove, and he took up his residence at the estate
of Tillemont, a short distance from Paris, near Vincennes, which
belonged to his family, and from which he took his name. In 1681 he
visited Flanders and Holland; and in 1682 undertook the charge of
the parish of St. Lambert, where he had formerly resided, but soon
gave it up at the desire of his father, to whom he ever paid the
greatest respect and obedience.
Having prepared the first volume of his great work on ecclesiastical
history, he was about to publish it when it was stopped by the censor,
under whose notice, as a work connected with theology, it had to pas;*,
and who raised some objections of the most frivolous character.
Tillemont refused to alter the parts specified, deeming them not justly
within the censor's province ; and chose rather to suppress the work,
upon which however he continued to labour diligently, though without
any immediate intention of publishing it.
This exorcise of the censorship led to an alteration of his plan : he
determined to separate from the rest of his work the history of the
Roman emperors and other princes whose actions were interwoven
with the afiairs of the Christian church, and to publish it separately :
the first volume of this work, which, as not being theological, was
exempt from the censorship, appeared in 1690, and was received with
general approbation. It excited a desire for the appearance of his
Church history, and the chancellor Boucherat, in order to remove the
obstacle to its pubUcation, appointed a new censor. Thus encouraged,
he brought out the first volume in 1693, under the title of 'Mdmoires
pour servir b, I'Histoire Ecclesiastique des Six Premiers Sicicles.'
A note to this volume, on the question whether Jesus Christ cele-
brated the Passover the evening before his death, in which he
examined the views of Bernard Lami, a learned priest of the Oratory,
on that question, involved him in a controversy with that writer, who
read Tillemout's note before publication, and examined the arguments
contained in it in a subsequent work of his own. Tillemont in con-
sequence addressed to Lami a letter, which is printed at the close of
the second volume of his ' Mdmoires,' and is remarkable for its spirit
of modesty and meekness. Lami replied, but Tillemont declined to
continue the discussion, thinking he had said enough to enable those
interested in the question to form a judgment, Faydit de Riom, an
ecclesiastic whom the Congregation of the Oratory had expelled from
their body, a man of considerable talent, but of jealous disposition,
published at Bale, in 1695, the first number (28 pp. 4to.) of a work, to
be continued every fortnight, entitled ' Mdmoires centre lea Memoires
de M. Tillemont.' It contained several violent and unjust strictures
on the work, to which Tillemont did not reply, though some of his
friends with needless apprehension procured the stopping of Faydit's
work, which never proceeded beyond the first number. Faydit
repeated his attack in a subsequent work, but it produced little
effect.
The remainder of Tillemont's life was passed in the quiet pursuit of
his studies. He waa attacked by a slight cough at the end of Lent,
1697, and in the course of the summer was seized with fainting,
owing to a sudden chill while hearing mass in the chapel of Notre
Dame des Anges : toward the end of September his illness increased
go as to excite the anxiety of his friends. He consequently removed
to Pai'is for the sake of medical advice ; and there, after an illness
which rendered his piety and submissiveness to the divine will more
conspicuous, he breathed his last, on Wednesday, 10th January 1698,
aged sixty years. He was buried in the abbey of Port Royal, in
which the Bernardine or Cistertian nuns, to whom the abbey had
originally belonged, were now again established.
The works by which Tillemont is known are, his'Histoire des
Empereurs,' and his ' Memoires pour servir h, I'Histoire Eccle'siastique.'
The first was published in 6 vols. 4to; the first four during the
author's life, at intervals from 1690 to 1697 : the remaining two after
his death, in 1701 and 1738. The earlier volumes were reprinted
at Brussels in 12 mo, in 1707, et seq., and a new edition appeared at
Paris, in 4to, iu 1720-23, with the author's latest corrections. He
explains his plan in the ' Avei-tissemcnt' to the first volume: his
intention was to illustrate the history of the Church for the first six
centuries ; but instead of commencing with the first persecutor, Nero,
he goes back to Augustus, whose edict occasioned the journey of
Joseph and Mary to Bethlehem, and thus determined the place of our
Lord's nativity. The history ends with the Byzantine emperor
Anastasius (a.d. 518). The style is unpretending, and consists for the
most part of a translation of the original writers with slight modifica-
tions, and with such additions (marked by brackets) as were needed to
form the whole into one continuous narrative, or such reflections as
the author deemed requisite to correct the false morality of heathen
writers. To each volume are appended notes relating to difficulties of
history or chronology which require discussion of a kind or extent
unsuited for insertion iu the body of the work. " There is nothing,"
says Dupin, " which has escaped the exactness of M. Tillemont ; and
there is nothing obscure or intricate which his criticism has not
cleared up or disentangled."
The 'Memoires,' &c., extend to 16 vols. 4to, of which the first
appeared in 1693; three volumes more during the author's lifetime, in
1694-5-6 ; and the fifth was in the press at the time of his death.
These five volumes camo to a second edition in 1701-2, and were
followed in 1702-11 by the remaining eleven, which the author had
teft in manuscript. This great work is on the same plan as the former,
being composed of translations from the original writers, connected by
pijragraphs or sentences in brackets. Dupin characterises it as being
not a continuous and general history of the Church, but an assemblage
of particular histories of saints, persecutions, and heresies, a description
accordant with the modest title of the work, * Memoires pour servir h,
I'Histoire,' &c. The author concerns himself chiefly with facts, with-
out entering into questions of doctrine and discipline ; and notices not
all the saints in the calendar, but only those of whom there are some
ancient and authentic records. Each volume has notes of similar
character to those given in ' L'Histoire des Empereurs.'
as for the Life of St. Louis, begun by De Sacy and finished and pub-
lished by La Chaise ; for the lives of St. Athanasius and St. Basil, by
Godefroi Hermant; of TertuUian and Origen, by Du Fossd, under the
name of La Mothe, &c.
( Vie de M. Lemain de Tillemont, by his friend Trouchay, afterwards
63
TILLOCH, ALEXANDER, LL-D.
TILLY, JOHN TSERCLAS.
64
eanon of Laval, Cologne, 1711 ; Dupin, BilliotMqw da Auteui'B EccU-
ritutiqutt du JJixseptidme Siicle ; liiograpMe UniverteUe.)
TILLOCH, ALEXANDKH, LL.D., was born at Glaagow, on the
28th of February 1759, and was educat«d with a view to followiug the
bunincM of bia father, who waa a tobacconist, and for many years
filled the office of magistrate in that city. He was however more
inclined to the pursuit of scientific knowledge than to the routine of
businesa. His biographer states that in early life his attention was
Ctly attracted by the occult sciences, and that although he was not
subject to their delusions, he never was inclined to treat judicial
astrology with contempt One of the earliest subjects to which
Tilloch applied himself was the improvement of the art of printing ;
his experiments enabled him, in connection with Foulia, the celebrated
printer of Glasgow, to carry farther the process invented by Ged of
Edinburgh, of printing from casts of whole pages of typej but he
stopped short of arriving at a practical application of stereotype
printing, though to his communications to Earl Stanhope, nearly
thirty years later, may be ascribed its eventual application. \iiQT
carrying on the tobacco business for a time in his native city in con-
nection with his brother and brotherin-law, Tilloch abandoned it, and
for several years exercised that of printing, either singly or in partner-
ship with others.
In 1787 he removed to London, where he subsequently resided ;
and in 1789 he, in connection with other parties, purchased the 'Star,'
a daily evening newspaper, of which he became editor. This office he
continued to hold until within a few years of his death, when bodily
infirmities and the pressure of other engagements compelled him to
relinquish it. The political opinions of Tilloch were temperate. For
many years ho devoted attention to means for the prevention of the
forgery of bank-notes, and in 1790 he made a proposal to the British
ministry on the subject, which met witli an unfavourable reception.
He then offered bia invention to the French government, who were
anxious to apply it to the printing of assignats ; but, after some expe-
the French authorities, all communication on the subject was cut
short by the pas-iing of the Treasonable Correspondence Bill. In
1797 he presented to the Bank of England a specimen note, produced
by block or relief printing, which was certified by the most eminent
engravers to be impossible of imitation ; yet nothing was done towards
the adoption of his or of any similar plan.
Considering that there waa room for a new scientific journal, in
1797, the first number of the ' Philosophical Magazine,' a periodical
which has ever since maintained a high reputation as a record of the
progress of science, and a digest of the proceedings of learned societies
at home and abroad. Of this work he was sole proprietor and editor
until a few years before his death, when Mr. Richard Taylor, who suc-
ceeded him in its management, became associated with him. In the
earlif r numbers of the * Star,' Tilloch published several essays on
theological subjects, some of which, relating to the prophecies, were
subsequently collected into a volume by another person, and published
with the name 'Biblicus;' and in 1823 he issued an octavo volume
entitled ' Dissertations introductory to the study and right under-
standing of the language, structure, and ;3ontents of the Apocalypse,'
in which he endeavours to prove that that portion of Scripture was
written much earlier than is usually supposed, and before most of the
apostolical epistle?. His views on this and other points are discussed
at length in a notice of this work, published soon after his death, in
the ' Eclectic Review.' The last work undertaken by Tilloch was a
weekly periodical entitled the ' Mechanic's Oracle,' devoted principally
to the instruction and improvement of the working classes. The first
number appeared in July 1824, and it was discontinued soon after his
death, which took place at his residence at Islington, on the 26th of
January 1825.
Tilloch married early in life. Ilia wife died in 1783, leaving a
daughter, who became wife of Mr. John Gait. His religious opinions
were peculiar, and he was one of the elders who acted as ministers of
a small body who took the name of Christian Dissenters, and met for
worship in a private house in Goswell Street Road. He was a member
of many learned societies in Great Britain and elsewhere, and was pro-
posed, about twenty years before his death, as a Fellow of the Royal
Society of London ; but his name was withdrawn before coming t6
the ballot, in consequence of an intimation that he would be objected
to, not on account of any deficiency in talent or character, but solely
because he was the proprietor of a newspaper. A memoir of Dr.
Tilloch appeared in the 'Imperial Magazine' for March 1825, from
wliich, with the assistance of other obituary notices, the above account
is condensed. This was reprinted in the last number of the ' Mechanic's
Oracle,' with a portrait.
TILLOTSON, JOHN, D.D. (died 1694), a prelate and one of the
moat celebrated divinea of the Church of England, was born in 1630
at Sowerby in Yorkshire, a member of the great parish of Halifax, of
a Puritan family. His father, who was engaged in the clothiLg trade
belonged to that extreme section of the Puritans who were for estab-
lisbiog a general system of Independency, and he belonged himself to
an Independent church, of which Mr. Root was the pastor. After
having been a pupil in the grammar-schools in the country, the writers
of his Life not having told us what schools they mean, but doubtless
the grammar-school at Halifax was one, he became a pensioner of
Clare Hall, Cambridge, in 1047, and a Fellow of the college in 1651.
It appears that he remained in the University till 1657. Puritanism
was at that period in the ascendancy at Cambridge ; but Tillotson very
early freed liimself from his educational prejudices, became a great
admirer of the writings of Chilhngworth, and soon showed himself
one of a class of persons who were then beginning to be considerable
in England, who, taking their stand on the Scriptures, opposed them-
selves at once to Romanism on the one hand and to Calvinism on the
other. This position he ever after maintained, and his celebrity arises
principally from the ability with which he illustrated and defended,
both from the pulpit and the press, the principles of Protestantism,
and of a rational and moderate orthodoxy. It may be added also,
that po much of the eflfects of his original Puritan education remained
with him, that he was in politics a Whig, although it must be owned
that he entertained and occasionally expressed notions of the duty of
submission, which, if acted upon, would have maintained the House of
Stuart on the throne.
Before he entered holy orders, he was tutor in the family of Pri-
deaux, the attorney-general to Cromwell. This led to his residence in
London, and brought him into acquaintance with several eminent
persons. He was thirty years of age before he received ordination,
and the service appears to have been performed with some degree of
privacy, as it is, we believe, not known when or where it was performed,
and only that the bishop from whose hands he received it was not a
bishop of the English Church, but the bishop of Galloway in Scotland,
Dr. Thomas Sydserf. All the supposed irregularities and imperfections
of his early religious history — for amongst other things it was even
asserted that he had never been baptised — were brought before the
public by the non-juring party, when they saw him elevated to the
primacy from which Bancroft had retired.
It is said by his biographer, Dr. Thomas Birch, that he was not per-
fectly satisfied with the terms of ministerial conformity required by
the Act of 1662, which restored the Episcopal Church of England;
yet on the whole he judged it proper to accept of the terms, and to
become a regular and conformable minister of that Church.
He was for a short time curate at Cheshunt, and also for a short
time rector at Ketton in Suffolk, a living to which he was presented
by Sir Thomas Barnardistou, one of hia Puritan friends. But he was
soon called to a wider sphere of duty, being appointed in 1664 the
preacher at Lincoln's Inn, and lecturer at St. Lawrence's church in
the Jewry. Here it was that those sermons were preached which
attracted crowds of the most accomplished and the learned of the
time, and which have been since read and studied by many succeeding
divines of eminence, and are at this day the basis of his fame.
The course of his preferment in the Church during the reign of
Charles II. was — 1669, a prebendary in the church of Canterbury ;
1072, dean of Canterbury; 1675, a prebendary in the church of St.
Paul; and 1677, a canon residentiary in the same cathedral. But as
soon as King William was established on the throne he was made dean
of St. Paul's and clerk of the closet; and in April 1691, he was
nominated by the king to the archbishopric of Canterbury, an appoint-
ment which appears to have been really received by him with reluct-
ance, aud which' exposed him to no small share of envy from very
different parties. The truth is, that besides his eminent merits as
having been the ablest opposer both of popery and UTcligion, in a
reign when the tendencies of too many persons in exalted stations
were in one or other of these directions, he had a strong personal
interest in the new king's afiections, who is said, on credible authority,
to have declared that there was no honester man than Dr. Tillotson,
nor had he ever a better friend. He was archbishop only three
years and a half, dying at the age of sixty-four. He was interred in
the church of St. Lawrence Jewry, which had been the chief scene of
his high popularity.
Tillotson died poor. He had survived both his children ; but he
left a widow, who was a niece of Cromwell and the stepdaughter of
Bisliop Wilkins, without any provision except the copyright of hia
works, which it is said produced 2500^. The king granted her a
pension, first of 400^., and afterwards of 200/. more, which she enjoyed
till her death in 1702.
An account of the Life of Dr. Tillotson was published in 8vo, 1717.
There is a much larger Life of him by Dr. Birch, prefixed to an edition
of the works of Tillotson, and published also in an Svo volume, the
second edition of which was printed in 1753, containing additional
matter. There is also an accovmt of him in Le Neve's ' Lives of the
Protestant Archbishops of England.' Birch's edition of the \Vorks is
in 3 vols, folio, 1752.
TILLY, or TILLI, JOHN TSERCLAS, Count of, was the son of
Martin Tserclas, of Tilly. The Tserclas, whose name is also written
T'Serclaes, were an old patrician family of Brussels ; John, a member
of this family, acquired, in 1448, the lordship of Tilly, in South Bra-
bant. John Tilly was born in 1559, at the castle of Tilly, and he early
entered the order of Jesuits, from whom he acquired that spirit of
fanaticism, of blind obedience, and of absolute command, which
distinguished him during hia whole life. He soon abandoned his
ecclesiastical profession, and entered the army of Philip II., king of
Spain and lord of the Netherlands, and he learned the principles of
war uoder Alba, Bequesens, the governor of tho Netherlands, Don
6S
TILLY, JOHN TSERCLAS,
TIM^US.
63
Junn of Austria, and Alexander Farnese. In the war of the Spaniards
against the Protestant inhabitants of the northern Netherlands ho
acquired that hatred of heretics and that warlike enthusiasm for the
Roman Catholic religion, which became one of the most prominent
features of his character. Towards the end of the 16th century he
entered tho service of the Emperor Rudolph II., and distinguished
himself, first as lieutenant-colonel, and afterwards as colonel and com-
mander of a regiment of Walloons, in the wars against the Hungarian
insurgents and the .Sultans Murad III. and Ahmed I. After the peace
of Sitvatorok in 1606, between Rudolph II. and Ahmed I., he was
appointed commander-in-chief of the army of Maximilian, duke of
Bavaria, which was in a very disorganised state. In 1609 Tilly com-
manded the expedition against Donauwerth, an imperial town which
had been put under the ban for having persecuted the Roman Catho-
lics, and which surrendered to Tilly without defence. The Liga, or
the union of the Roman Catholic states in Germany, appointed him
commander-in-chief of their troops, and he held this high office until
his death. Tilly gained the first great victory in the Thirty Years'
War, which broke out in 1618. After having conquered the Upper
Palatinate with the troops of the Liga and those of the Duke of
Bavaria, he proposed to the Imperial generals to pursue the army of
Frederick, king of Bohemia, instead of taking winter-quarters and
thus losing all the fruits of their conquests. Warfare in winter was,
in the 17th century, a very uncommon thing, and Tilly met with
much opposition to his plan ; but at last the Imperial generals con-
sented to continue the war. Tilly attacked the Bohemians, who had
taken up a fortified position on the Weisse Berg, near Prague, and in
a few hours the Bohemian army was nearly destroyed (8th of Novem-
ber 1620), while only some hundreds of the Bavarians were killed.
Several of the Bohemian nobles, who lived at Prague or resided in
their castles, were warned by Tilly to fly if they would avoid the
vengeance of the emperor ; but they paid no attention to this generous
After the brilliant victory on the Weisse Berg, Tilly hastened to the
Rhine for the purpose of preventing the Count of Mansfield from
joining the margrave of Baden. He succeeded in his object by his
skilful manoeuvres. The margrave of Baden-Durlach was attacked in
the defiles of Wimpfen, and defeated, after an heroic resistance (1622).
On the 2nd of June 1622, he defeated Christian of Halberstadt at
Hochst ; he pursued Christian and Mansfield to Westphalia ; defeated
them at Stadt-Loo, near Miinster, in a battle which lasted three days
(4th to the 6th of August 1623), and forced them both to disband
their troops and to take refuge in England. For this victory at Stadt-
Loo, Tilly was created a count of the empire. With extraordinary
skill Tilly first weakened and then destroyed the army of King
Christian IV. of Denmark ; but the principal glory of this campaign
was earned by Waldstein, who after having joined Tilly on the banks
of the Lower Elbe, persuaded Tilly to turn his arms against Holland,
and to leave him the conquest of Denmark. After Waldstein had been
deprived of his command in 1630, and Gustavus Adolphus, king of
Sweden had landed in Germany, Tilly was appointed field-marshal and
commander-in-chief of the imperial army. He appreciated so justly
the military talents of his new opponent, that in the assembly of the
electors of Ratisbon he declared Gustavus Adolphus to be so great a
commander, that not to be beaten by him was as honourable as to
gain victories over other generals.
The first great event of the new campaign was the capture of
Magdeburg, on the 10th of May 1631. The Croats and the Walloons in
the imperial army committed unheard-of cruelties against the unhappy
inhabitants ; 30,000 of them were killed, and the town was entirely
destroyed after three days' plunder. It has generally been believed
that some imperial officers besought Tilly to stop the atrocities of the
soldiers, and that he coolly answered, " Let them alone, and come back
in an hour." But this appears to be a mere invention, and however
severe Tilly was, he cannot be charged with having urged the commis-
sion of cruelty, although he considered the plunder of a conquered
town as the fair reward of the soldier. On the 14 th of May Tilly
made his enti-ance into the smoking ruins of Magdeburg. In a letter
to the emperor he said that since tbe destruction of Troy and Jerusa-
lem there had been no such spectacle as that which Magdeburg pre-
sented. Six months later Tilly, who was in a fortified camp at
Breitenfield near Leipzig, was forced, by the impetuosity of his lieu-
tenant, Pappenheim, to engage in battle with Gustavus Adolphus
before his reinforcements had arrived. Tilly himself was successful
in his attack on the left wing of the Swedes, which was broken, and the
elector of Saxony, who commanded it, fled as far as Eilenburg. But
under the command of Pappenheim, stopped the progress of Tilly, and
after a long and bloody struggle the imperial army was routed. When
Tilly saw the flight of his soldiers, he swore that he would not survive
the day on which he, the victor in thirty-six battles, was to fly for tho
first time in his life. Alone on the field the old field-marshal, bleeding
from three wounds, shed tears of despair, and looked for death as his
only consolation. However Duke Rudolph of Saxe-Lauenburg per-
suaded him to withdraw; and Tilly, putting himself at the head of
four regiments of veterans, fought his way through the main body of
the Swedish army. He narrowly escaped from the bold attack of a
Swedish captain, called ' Long-Fritz,' who was killed by a pistol-shot
> BIOG. DIV. VOL. VI.
at the moment when he was seizing the field-marshal (17th of Septem-
ber 1631). After the loss of the battle of Leipzig, fortune abandoned
Tilly for ever. Although he afterwards succeeded in driving the
Swedes from Franconia, Gustavus Adolphus compelled him to retire
beyond the Lech. In order to prevent the Swedes from penetrating
into Bavaria, Tilly took up a very strong position near liain, on the
right bank of that river. Gustavus Adolphus, having arrived on tho
left bank opposite Rain, opened a fire from all his batteries upon the
Bavarian camp, while his pontooniers endeavoured to construct a
bridge over the river (5th of April 1632). Tilly made a most active
resistance, but a ball broke his thigh, and he was removed from the
field and carried to Ingolstadt. After the fall of Tilly, the elector of
Bavaria abandoned his invincible position, and the Swedes crossed the
river. Tilly died on the day after the battle, in his seventy-third
year, without leaving any issue.
Tilly was a little ugly man, with red hair, large whiskers, a pale
face, and piercing eyes. He continued to lead a monastic life in the
midst of the noise and the licence of his camp ; he boasted that he had
never touched wine nor women ; he spoke little, but thought much ;
he despised honours and money ; the emperor wished to confer the
duchy of Brunswick-Calenberg upon him, but Tilly refused it, and he
died poor.
(Julius Bellus, Laurea Austriaca ; Breyer, Geschichte des Breissig-
jahrigen Krieges ; Schiller, Geschichte des Dreissigjdhrigen Kriegei ;
Leo, Universal-Geschichte.)
TIM.iEUS (Ti/jiaios), the son of Andromachus, was bom at Taurome-
nium in Sicily, whence he is sometimes called a Tauromenian, and
sometimes a Sicilian, to distinguish him from other persons of the
same name. The year of his birth was B.C. 352. He was a disciple of
Philiscus of Miletus, who had himself been instructed by Isocrates.
He was driven from his native country by Agathocles, the tyrant of
Syracuse, whereupon he went to Athens. This seems to have hap-
pened in B.C. 310, when Agathocles, after the battle of Himera, and
before taking his army over to Africa, confiscated under, various pre-
texts the property of his wealthy subjects, and endeavoured to secure
his possessions in Sicily by putting to death or sending into exile such
as he thought ill-disposed towards him. (Diodorus Siculus, xx. 4.)
Timseus spent fifty years at Athens in reading and studying, (Polybius,
xii. 25.) About B.C. 260, when Athens was taken by Antigonus, Timseus
returned to his native country, either to Tauromenium or to Syracuse,
where he spent the remainder of his life, and died (B.C. 256) at the
Timseus wrote a great historical woi-k, the main subject of which
was a history of Sicily. It began at the earliest times, and brought
the events down to Olympiad 129 (b.c. 264), where the work of Poly-
bius begins. (Polybius, i. 5.) How many books the history contained
is uncertain, though we know that there were more than forty. It
appears to have been divided into large sections, each of which formed
in itself a separate work, whence they are spoken of by several writers
as so many independent works. Thus one section bore the title of
St/ceAtKia ical 'IraXiKa, and contained the early history of Sicily in con-
nection with that of Italy ; another was called Si/ceAt/ca koI 'EWrjviKci,
and oontained the history of Sicily and Greece during the time of the
Athenian expeditions to Sicily. Another part again contained the
history of Agathocles ; and the last the history of PyiThus, especially
his campaigns in Italy and Sicily. This last section was, according to
the testimony of Cicero (' Ad. Fam.,' v. 12), a separate work, though,
as regards the period which it comprehended, it may be viewed as a
continuation of the great historical work.
The history of Timajus, which, with the exception of a considerable
number of fragments, is now lost, was commenced by him during his
exile at Athens, and at a very advanced age, but he did not complete
it till after his return to his own country ; and it was here that he
added the history of the last years of the reign of Agathocles, and
wrote the history of Pyrrhus. As regards the character and value of
the work the ancients do not agree. Polybius is a vehement opponent
of Timseus, and complains of his ignorance of political as well as mili-
tary affairs; he further states that Timseus made blunders in the
geography even of places and countries which he himself had visited.
His knowledge, he says, was altogether derived from books ; his judg-
ment was puerile ; and the whole work bore strong marks of credulity
and superstition. But this is not all that Polybius blames : he even
charges him with wilfully perverting the truth. The fondness which
Titnseus himself had for censuring others is said to have drawn upon
him the nickname of Epitimseus (' fault-finder'). (Athenseus, vL 272.)
Most parts of this severe criticism of Polybius may be perfectly just ;
but in regard to others we should remember that these two historians
wrote their works with such totally different views, that the work of
Timseus, who knew the world only from his books, must in many
respects have appeared absurd to the author of a * pragmatical ' history,
and to a statesman and general like Polybius. But the loss of the
work of *TimsGus, even if he did no more than make an uncritical com-
pilation of what others had told before him, is one of the greatest in
ancient history. Other ancient writers, such as Diodorus, Agathar-
chides, Cicero, and others judge far more favourably of Timseus. ^ The
style of the work, as far as we can judge from the fragments, is justly
censured by some ancient critics for its rhetorical and declamatory
character ; although others, like Ciceio (' De Orat.,' ii. 1 4 ; ' Brutus,' 95),
•7
TIMiEUa
TIMB3, JOHN.
63
•peak of it with praue. Timeoua is the first Greek historian who intro- 1
duoed a regular eystem of obronology— that is, he regularly recorded |
events aocordiug to Olympiads and the archons of Athens ; and
although in the early period of his history his want of criticism
led him into gross chronological errors, he set the example which
othera found very useful and oouvenient. It must have been with a
vi.:w to an accurate study of chronology that he wrote a work on the
victors in the Olympian Games, of which we still possess a few
iragmenta.
The fragments of Timojus are collected in GoUer's work, ' De Situ
•t Origine Syraousanim,' p. 207, &a, which also contains (pp. 179-206)
an elaborate dissertation on the life and writings of Timaeus. The
fragmento are also contained in C. and T. Miiller, • FragmenU Histori-
oorum Grajcorum,' Paris, 1841, pp. 193-233. Compare Vossius, Be
Hiitoricit Oracit, p. 117, edit. Westermanu; Clmtou, Fast. Udlen., iiL,
p. 489, fte.
TlMiEUS (Tlfiaios), of Locri, a Pythagorean philosopher, was a con-
temporary of Plato, who is mentioned among his pupils, and is said to
have been connected with him by friendship. (Cicero, ♦ De Finibus,'
T. 29 ; ' De Re Publ.,' I 10.) There exists a work, Xltpl rris rod K6(Tfiov
'j'l'X^i (' I>* Anima Mundi,' or on the Soul of the Universe), written in
the Doric dialect, which is usually ascribed to Timrous the Locrian. It
contains a brief exposition of the same ideas which are developed in
the ' Dialogue ' of Plato, which is called after hira Timaeus. (Tenne-
mann, ' System der Platonischen Philosophie,' i. 93, &c) Separate
editions of it have been published by D'Argens, 8vo, Berlin, 1762, with
a French translation; and by J. J. de Gelder, 8vo, Leyden, 1836.
This Timseus of Locri is said by Suidas to have also written the
Life of Pythagoras; but the usual carelessness of Suidas renders this
a doubtful point, as he may possibly have confounded the Locrian with
the Sicilian Timajus, who in his great liistorical work must have treated
of the History of Pythagoras at considerable length.
(Fabricius, Bihlioth. Grac, iii. 94, &c. ; Goller, De Situ ct Origine
Syracuiarum, p. 200, &c.)
TIM.^US, a Greek sophist, who, according to the supposition of
Ruhuken, lived in the 3rd century of the Christian era. Concerning
his life nothing is known ; his name has only come down to us in con-
nection with a vocabulai-y containing the explanation of words and
phrases which occur in the writings of Plato. It bears the title
iK rHy rov IWdruvos Ae'feaii', and is dedicated to one Gentianus, of
whom likewise nothing is known. Whether we possess the genuine
aod complete Vocabulary of Timaeus is doubtful ; and from the title,
as well as from certain articles in it which have no reference to Plato,
and must undoubtedly be regarded as interpolations, one might feel
inclined to consider the work as it now stands as an abridgment of
the Glossary of Timaeus, if Photius, who must have had the genuine
work before him, did not describe it as a very little work {fipaxv
■woyrfixdrioy iv ivl ^6y<i>). But notwithstanding its brevity, the work is
very valuable ; and Kuhnken owns that he has not discovered in it a
single instance of a word or a phrase being explained incorrectly.
There is only one manuscript of this Glossary, which appears to have
been made in the 1 0th century of our era, and which was unknown
until Montfaucon drew attention to it. It was first edited, with an
excellent commentary, by Ruhnken, at Loyden, 8vo, 1754 ; a second
and much improved edition appeared in the same place, 8vo, 1789.
Two other editions have since been published in Germany, with
additional notes by Q. A. Koch (8vo, Leipzig, 1828 and 1833).
Suidas («. V. Tifiaios) ascribes to Timaeus, the Sicilian historian, a
rhetorical work, called 'SvWoyif {n\TopMmv a(popfiwv, in 68 books, which
Ruhuken, with great probability, ascribes to Timseus the Sophist, who
wrote the Glossary to Plato.
(Ruhnken, Prcefalio ad Timaei Glossarium Platonicum.)
TIMANTHES, a native of Sicyon or of Cythnos, was one of the
most celebrated painters of Greece ; he was contemporary with Zeuxis
and Parrhasius, and lived about B.C. 400. The works of Timanthes
were distinguished particularly for their invention and expression, and
one of the chief merits of his invention was, that he left much to be
supplied by the imagination of the spectator. There is a remark in
Pliny (' Hist. Nat.,' xxxv. 36), probably a quotation, which bestows the
highest praise upon Timanthes : it says, though in execution always
excellent, the execution is invariably surpassed by the conception.
As an instance of the ingenuity of Timanthes' invention, the same
writer tells us of a picture of a sleeping Cyclops, painted upon a small
panel, but in which the painter had conveyed a perfect idea of the
giant's huge size, by adding a few satyrs measuring his thumb vrith a
thyrsus.
Though Timanthes was evidently one of the greatest painters of
antiquity, ancient authors have mentioned only five of his works :
Pausanias makes no mention of him at all, and Cicero classes him
among the painters who used only four colours. He painted a cele-
brated picture of the stoning to death of the unfortunate Palamedes,
the victim of the ignoble revenge of Ulysses for having proclaimed his
apparent insanity to be feigned — a subject worthy of the pencil of a
great master. This picture is said to have made Alexander shudder
when he saw it at Ephcsus, (Tzetzes, ' Chil.,' viii. 198 ; Junius, ' Cat.
Artif.,' V. 'Timanthes.') Timanthes entered into competition with
Parrhasius at Samos, and gained the victory ; the subject of the paint-
ings was the cqnteat of Ajax and Ulysses for the arms of Achilles
[Pabbhasius.] His most celebrated work however was that with
which he bore away the palm from Colotes of Teos; the subject was
the Sacrifice of Iphigenia ; and perhaps no other work of ancient art
has been the object of so much criticism, for and against, as this
painting, on account of the concealment of the face of Agamemnon in
his mantle. The ancients have all given the incident their unqualified
approbation, but its propriety has been questioned by several modern
critics, especially by Falconet and Sir Joshua Reynolds; Fuseli, how-
ever, in an elaborate and excellent criticism in his first lecture, has
amply j ustified the conception of the painter. The Sacrifice of Iphi-
genia was given as the subject of a prize-picture to the.studenta of
the Royal Academy in 1778, and all the candidates imitated the 'trick'
of Timanthes, as Sir Joshua Reynolds terms it, which was the origin
of his criticism upon the subject in his eighth lecture : he Fays,
" Supposing this method of leaving the expression of grief to the
imagination to be, as it was thought to be, the invention of the
painter, and that it deserves all the praise that has been given it, still
it is a trick that will serve but once ; whoever does it a second time
will not only want novelty, but be justly suspected of using artifioe to
The shallow remark of Falconet about Timanthes' exposing his own
ignorance by concealing Agamemnon's face, is scarcely worthy of an
allusion. It may be questioned whether Agamemnon, under such
circumstances as he was placed, could have been well or even natu-
rally represented in any other way : although many things might
combine to render his presence at the sacrifice absolutely necessary,
still it is not to be supposed that he could calmly stand by and be un
eye-witness of his own daughter's immolation ; notwithstanding his
firm conviction that his attendance was necessary to sanction the
deed, he could not look upon it, it would be unnatural. The criticism
of Quintilian, Cicero, and others, that the painter, having represented
Calchas sorrowful, Ulysses much more so, and having expressed extreme
sorrow in the countenance of Menelaus, was in consequence compelled
to conceal the face of the father, is not mora pertinent than that of the
modern critics. "They were not aware," says Fuseli, "that by making
Timanthes waste expression on inferior actors at the expense of a
principal one, they call him an improvident spendthrift, and not a wise
economist." Falconet observes that Timanthes had not even the
merit of inventing the incident, but that he copied it from Euripides :
upon this point J'useli remarks, " It is observed by an ingenious critic
that in the tragedy of Euripides the procession is described; and
upon Iphigenia's looking back upon her father, he groans and hides
his face to conceal his tears; whilst the picture gives the moment
that precedes the sacrifice, and the hiding has a different object, and
ari-sea from another impression " (v. 1650).
" I am not prepared with chronologic proofs to decide whether
Euripides or Timanthes, who were contemporaries about the period
of the Peloponnesian war, fell first on this expedient; though the
silence of Pliny and Quintilian on that head seems to be in favour of
the painter, neither of whom could be ignoi"ant of the celebrated
drama of Euripides, and would not willingly have suffered the honour
of this master-stroke of an art they were so much better acquainted
with than painting, to be transferi-ed to another from its real author,
had the poet's claim been prior." As far as regards priority, the
' expedient ' was made use of by Polygnotus long before either Timan-
thes or Euripides; in the Destruction of Troy, in the Lesche at
Delphi, an infant is holding his hands over his eyes, to avoid the
horrors of the scene. (Pausanias, ' Phoc.,' x. 26.)
The fifth work of Timanthes mentioned by the ancients was the
picture of a hero, preserved in the time of Pliny in the Temple of
Peace at Rome, an admirable performance.
There was another ancient painter of the name of Timanthes ; he
was contemporary with Aratus, and distinguished himself for a
painting of the battle of Pellene, in Arcadia, in which Aratus gained
a victory over the yEtolians, Olym. 185.1 (b.c. 240). Plutarch praises
the picture ; he terms it an exact and animate representation.
('Aratus,' 32.)
* TIMBS, JOHN, was bom in 1801, at Clerkenwell, London. He
was educated under the Rev. Joseph Hamilton, D.D., and his brother,
Mr. Jeremiah Hamilton, at New Marlows, Hemel Hempstead, where
he issued a manuscript newspaper for the edification of his school-
fellows. At the age of fourteen he was articled to a druggist and
printer at Dorking, in Surrey, where, at his master's table, he first
met Sir Richard Phillips, the publisher, who kindly encouraged him to
contribute to his ' Monthly Magazine,' and he furnished to that work
' A Picturesque Promenade round Dorking,' in 1822. In 1821 John
Timbs came to London, and for some years served as amanuensis to
became acquainted with Mr, Britton, F.S.A., with whom he long main-
tained an unbroken friendship. In 1825-26 Mr. Timbs published
anonymously ' Laconics,' an excellent selection of moral passages, the
result of a course of ethical reading. In 1827 he became editor of
' The Mirror,' and so continued until 1838; compiling also an annual
volume of records of Discoveries in Science and Art. This design
he improved as ' The Year-Book of Facts ' in 1839, fitly characterised
as "a laborious production of patient industry." Besides contributing
to periodicals, Mr. Timbs has written, compiled, and edited at least a
hundred volumes. His most recent and most successful works are —
60
TIMOLEON.
TIMON.
70
* Curiosities of London,' 800 pp., 1855 ; * Things not generally known
familiarly Explained,' and ' Curiosities of History,' 1856: of the two
latter works, more than 20,000 copies were sold within twenty months.
His 'Arcana of Science' was published yearly from 1828 to 1839 inclu-
sive, and his ' Year-Book of Facts ' from 1839 to 1857. Soon after the
establishment of the ' Illustrated London News,' in 1842, Mr. Timbs
became one of its editors, in which position he has ever since con-
tinued. In 1854 be was elected Fellow of the Society of Antiquaries.
TIMO'LEON, a Greek general and statesman. He was a native of
Corinth, and the son of Timodemus and Timariste. Respecting his
youth we know nothing, except that he was no less distinguished by
his noble character and his love of freedom than by his illustrious
descent. When he had grown up to manhood, his elder brother
Timophanes, who had been elected general by the Corinthians, assumed
the tyrannis in his native city by the help of his friends and his
mercenaries. Timoleon at first only renaonstrated with his brother,
but when this was usoleis, he formed a plot against him, and Timo-
phanes was killed. Soon after this event, which threw all Corinth
into a state of violent agitation, some extolling the conduct of Timo-
leon as magnanimous and worthy of a real patriot, others cursing and
condemning him as a fratricide, there arrived at Corinth ambassadors
from Syracuse soliciting the aid of tho Corinthians against its op-
pressors. This was a favourable opportunity for the party hostile to
Timoleon to get rid of his followers, while at the same time it opened
to Timoleon a field of action in Sicily, where he might act according
to his principles and deliver the island from its oppressors. Timoleon
was accordingly sent to Syracuse with a small band of mercenaries,
which he himself had raised, B.C. 844. Syracuse was then divided
into three parties : the popular party, which had engaged the service
of Timoleon ; a Carthaginian party ; and the party of Dionysius, the
already been driven out of a part of the city by Hicetas, the tyrant of
Leontini, who supported the Carthaginian party. On the arrival of
Timoleon, Hicetas was compelled to withdraw to Leontini, and
Dionysius, who was reduced to surrender himself and the citadel to
Timoleon, was allowed to quit the island in safety, and he withdrew
to Corinth, in B c. 343. [Dionysius.] Syracuse had almost become
desolate by the successive revolutions and party warfare. During the
winter and the spring following his victory over Dionysius, Timoleon
endeavoured as much as was in his power to restore the prosperity of
the city by recalling those who had been exiled, and by inviting
colonists from other parts of Sicily and assigning lands to them. After
this he continued to carry on petty warfare partly against the Cartha-
ginians and partly against Hicetas. The Carthaginians in the mean-
time collected a new army, which is said to have consisted of 70,000
foot and 10,000 horse, and which was conveyed to Sicily by a large
fleet. Timoleon could muster no more than 3000 Syracusans and
9000 mercenaries, but in order to strengthen himself he concluded a
peace with Hicetas, some of whose troops now joined his army. He
marched out against the enemy, and by his superior generalship he
succeeded in gaining a brilliant victoiy over the Carthaginians on the
banks of the river Crimessus, and confined them to the part of Sicily
between the river Halycus and the western coast, B.C. 339. After this
victory and the conclusion of a peace with Carthage he directed his
arms against the tyrants in other towns of Sicily, whom he compelled
to surrender or withdraw, partly by the terror of his name and partly
by force of arms. Hicetas was made prisoner, and condemned to
death by the Syracusans, with his wife and family.
After freedom and the ascendancy of Syracuse were thus restored in
the greater part of Sicily, Timoleon directed his attention to the
restoration of the prosperity of the towns and the country. The
former, especially Syracuse, were still thinly peopled, and he invited
colonists from Corinth and other parts to settle there, and distributed
lands among them. He himself, with the consent of the Syracusans,
undertook to revise and amend their constitution and laws, and to
adapt them to the altered wants and circumstances of the state.
Although it would have been easy for him to establish himself as
tyrant and to secure to his descendants the kingly power at Syracuse,
he fulfilled the duties of the office entrusted to him with a fidelity
which has rarely been equalled. He had no other end in view but the
establishment of popular liberty, for which he prepared and trained
the people. Some acts of cruelty and apparent injustice with which
he is charged, find their excuse in the character of those whom he had
to deal with, for the Syracusans at that time were a motley and
demoi-alised people, who could not be managed without Timoleon's
assuming at times the very power which it was his wish to destroy.
But Syracuse and Sicily felt the benefits of his institutions for many
years after his death, and continued to enjoy increasing prosperity.
During the latter part of his life Timoleon was blind and lived in
retirement, respected and beloved by the SiciliaiiB as their liberator
and benefactor. He died in the year B.C. 337, and was buried in the
Agora of Syracuse, where subsequently his grave was surrounded by
porticoes and adorned with a gymnasium called the Timoleonteum.
(Plutarch, and C. Nepos, life of Timoleon; and Diodorus Siculus,
lib. xvi.)
TIMO'MACHUS, a celebrated ancient painter, a native of Byzan-
tium, and said to have been the contemporary of Julius Caesar. Pliny
(' Nat. Hist.,' XXXV. 40) informs us that Csesar purchased two pictures
in encaustic by Timomachus, for eighty Attic talents, about 17,280i. ;
one representing Ajax the sou of Telamon brooding over hia mis-
fortunes ; the other, Medea about to destroy her children : he dedi-
cated them in the temple of Venus Qenetrix. These pictures have
been much celebrated by the poets ; there are several epigrams upon
them in the Greek anthology, and they are alluded to by Ovid iij the
two following lines : —
"Utque sedet vultu fassus Telamonius iram,
Inque oculis facinuB barbara mater habet." (' Trist.,' ii. 525.)
(Ajax, the son of Telamon, is seated, showing his anger by hiB countenance ;
and the barbarous mother betrays by her eyes her intended crime.)
We learn from Pliny also that the picture of Medea was not finished ;
its completion was interrupted apparently by the death of the painter,
yet it was admired, he says, more than any of the finished works of
Timomachus, as was the case likewise with the Iris of Aristides, the
Tyndaridse of Nicomachus, and a Venus by Apelles, which were more
admired than any of the finished works of their respective masters.
This picture is noticed also by Plutarch ('De Aud. Poet.,' 3) in a
passage where he speaks of the representation of improper subjects,
but which we admire on account of the excellence of the execution.
In the common text of Pliny, Timomachus is said to be the con-
temporary of Csesar (' Julii Caesaris setate '), but Durand, in his
' Histoire de la Peinture Ancienne,' &c., expresses an opinion that the
word 'setate* is an addition of the copyist, for which he assigns
several reasons. The conjecture has much in its favour; the price of
these pictures (17,28tZ.) is enormous, if we suppose it to have been
paid to a living painter ; but on the contrary it is a case with many
parallels if we suppose the money to have been paid for two of the
reputed masterpieces of ancient painting. The fact of the Medea
being unfinished puts it beyond a doubt that the picture was not
purchased of the painter himself ; and from a passage in Cicero (' In
Verr.,' 1. iv., c. 60) it seems equally clear that both pictures were
purchased of the city of Cyzicus ; and from the manper in which
they are mentioned with many of the most celebrated productions of
the ancient Greek artists, it would appear that they were works of
similar renown, and were likewise the productions of an artist long
since deceased. Timomachus was therefore most probably a contem-
porary of Pausias, Nicias, and other encaustic painters, about B.C. 300.
Pliny himself, elsewhere speaking of Timomachus, mentions him
together with the more ancient and most celebrated painters of Greece,
with Nicomachus, Apelles, and Aristides, as in the passage above quoted.
Pliny mentions also the following works of Timomachus : an
Orestes; and Iphigenia in Tauris; Lecythion, a gymnasiast; a *cog-
natio nobilium;' two philosophers or others, with the pallium, about
to speak, one standing, the other sitting; and a very celebrated
picture of a Gorgon.
TIMON (Tijucoi'), a Greek poet and philosopher who lived in the
reign of PtoleraEeus Philadelphus, about B.C. 270. He was the son of
Timarchus, and a native of Phlius in the territory of Sicyon. He
studied philosophy under Stilpo, at Megara, and under Pyrrho, in
Elis. He subsequently spent some time in the countries north of the
JSgean, and thence went to Athens, where he passed the remainder of
his life, and died in the ninetieth year of his age.
Diogenes Laertius, who has written an account of Timon (ix., c. 12),
ascribes to him epic poems, sixty tragedies, satyric dramas, thirty
comedies, silli {aiWoi), and cinsedi (/ciVaiSoi) or licentious songs. The
silli however appear to have been the kind of poetry in which he
excelled. They were satires directed against the arrogance and pedantry
of the learned. Timon wrote three books of silli (Athenasus, vi., p.
251 ; vii., p. 279), in which he parodied all the dogmatic philosophers
of Greece : he himself was a Sceptic. The metre of these poems was
the hexameter, and it appears that sometimes he took whole passages
from Homer which he applied as parodies. In the first book Timon
spoke in his own person ; in the second and third the form of the
poems was that of a dialogue, in which he conversed with Xenophanes
of Colophon, who was supposed to have been the inventor of the
silli. (Diogenes Laert., ix. 111.) We now only possess a few fragments
of these poems, which show that in their way they must have been
admirable productions. They are collected in H. Stephanus, ' Poesis
Philosophica ;' and by Wolke in *De Graecorum Syllis,' Warsaw, 1820;
in F. Paul, ' De Sillis Graecorum,' Berlin, 1821, p. 41, &c. ; in Brunck's
' Analecta,' ii. 67; and iv. 139. Respecting the other works ascribed
to him we possess no information.
(J. F. Langheinrich, De Timone SUlographo, in 3 parts, Lipsise,
1720-23.)
TIMON, surnamed the Misanthrope, was a son of Echecratides, and
a native of Colyttus, a demos in Attica. (Lucian, 'Timon,' c. 7;
Tzetzes, ' Chil.,' vii. 273.) He lived during the Peloponnesian war, and
is said to have been disappointed in the friendships he had formed,
in consequence of which he conceived a bitter hatred of all mankind.
His conduct during the period that his mind was in this state was
very extraordinary. He lived almost entirely secluded from society,
and hia eccentricities gave rise to numerous anecdotes, which were
current in antiquity. The sea is said to have separated even his
grave, which was on the sea-coast, from the mainland, by forming it
into an island and thus rendering it inaccessible. (Plutarch, 'Anton.,
70 ; Suidas, a. v. a.itop^u>ya.s.) The comic poets, such aa Phrynichus
TIMOTEO DA URBINO.
TIMOTHEUS.
72
(Bekker. ' Anecdota,' p. 844), Aristophanes (' LysUtr., 809, &c. ;
'Avea,' 1548), Plato, and Antiphanes, ridiculed him in their comedies.
Anliiihanes wrote a comedy culled ' Timon,' which perhaps furnished
Lucian with the groundwork for hia dialogue in which this misantlirope
acts the moat prominent part. Hia name has remained proverbial to
designate a misanthrope down to the present day, and is immortalised
by the Kenius of Shakspere.
TIMOTE'O DA URBI'NO, or DELLA VITE, a celebrated Italian
pointer of the Roman school, was born at Urbino in 1470, or rather
1480. In about his 20th year, by the advice of a brother living in
Bologna, he repaired to that city to learn the busineas of a jeweller,
&c. ; but diaplayinga power of deaign worthy of a greater purpose, he
dovoted himself to painting, and according to Malvasia attended the
school of Fraucia in Bologna for about five years : Vasaii however
says that Timoteo was his own master. At tho ago of twenty-six he
returned to Urbino, where in a short time he so far distinguished
himself, says Vaaari, as to recive an invitation from his cousin
Itaffaelle in Rome to repair thither aud assist him in some of hia
extensive works. This statement creates a difficulty not easy to be
cleared up : Vaaari says that Timoteo died in 1524, aged fifty-four ;
yet we find him in his twenty-seventh or twenth-eighth year, conse-
quently in 1497 or 1498, going to Rome to assist RafTaelle, who
however did not go to Rome himself until 1508 : 1524 was very pro-
bably therefore a misprint for 1534 in the original edition of Vasari,
and the error has found its way into all the later works. By this
supposition aud by allowing a year or two to have elapsed between
hia return to Urbino and hia visit to Rome, the various dates may be
easily reconciled, and what Vasari says about Timoteo's assisting
Rafiaelle to paint the Sibyls in the Chiesa della Pace, which were
painted in 1511, becomes quite consistent. He did not remain long
in Rome, but returned to hia native place at the solicitation of his
mother, much to the displeasure of Raffaelle. He remained however
long enough to learn to appreciate and to imitate the beauties of
Raffaelle's style, and to become one of the most distinguished painters
of the Roman school; yet there are in all his works traces of the
style of Fraucia, a certain tiinidity of design, a delicacy of execution,
aud a richnesa of colouring. Hia chief works are at Urbino, at Forli,
and in the neighbourhood ; he executed many of them in company
with Girolamo Qenga, as a chapel at Forli and part of the paintings iu
the chapel of San Martino in the Cathedral of Urbino ; the altar-piece
was painted entirely by Timoteo : he executed also some excellent
works iu fresco at Castel Durante. Further, in Urbino there are — in
the Cathedral, a Magdalen ; in San Bernardino, outside the city, a
celebrated picture of the Annunciation of the Virgin ; and another
fine picture with several figures in Santa Agata ; also in the residence
of the Dukes of Urbino, an Apollo and two of the Musea, extremely
beautiful ; besides many other works. Vasari remarks that he left
some works unfinished at his death, which were afterwards completed
by others, and he adds that there could not be a more satisfactory
evidence of the general superiority of Timoteo. He was of a cheerful
disposition, and used to play every kind of instrument, but especially
the lyre, which he accompanied with his voice, with extraordinary
grace and feeling. Lanzi says that the Conception at the Observau-
tines at Urbino, and a ' Noli me tangere ' in the church of Sant'
Angelo at Cagli, are perhaps the best of his works that remain. The
same writer observes that Pietro della Vite, the brother of Timoteo,
also a painter, was probably the priest of Urbino mentioned by Baldi-
uucci (vol. V.) as Raffaelle's cousin and heir.
TIMO'THEUS (Tifx6efos) of Miletus, a Greek musician and lyric
poet. The time when his reputation had reached its height was
about the year b.c. 398. (Diodorus Sic, xiv. 46.) He was a contem-
poi-ary of Euripides, and spent the last year of his life at the court of
Macedonia, where he died in B.C. 357, at the advanced age of 97. He
increased the number of the strings of the lyre to eleven, an innova-
tion which was considered by the Spartans, who would not go beyond
the number of seven strings, to be a corruption of music, and a decree
was passed at Sparta, which is still extant in Bocthius, condemnatory
of his innovation. (Plutarch, • De Mus.,' p. 1141, ed. Fraukf. ; Athe-
nseus, xiv. p. 636.) Suidas mentions a great number of poetical com-
positions of Timotheus, which were in their time very popular in
Greece ; among them are nineteen nomes, thirty-six proojmia, eighteen
dithyrambs, and twenty-one hymns. All these works are now lost,
witli the exception of a few fragments which are preserved in Athe-
n^eus and the grammarians.
(Vobsius, De Poetis Cb-cecis, p. 46 ; Bode, Oeachichte der I/yrisclien
Dichtlcunst der Hellenen, vol. ii. p. 305, &c.)
TIMO'THEUS {Tiixddfos), an Athenian poet of the so-called middle
comedy. Suidas mentions the titles of several of his plays, and
Athenaeus (vi. p. 243) has preserved a fragment of one which bore the
title 'The Little Dog.' (Compare A. Meineke, Historia CHtica Comi-
corum Qrcecorum, p. 428.)
TIMO'THEUS, son of Couon of Athens. He inherited from his
father a considerable fortune, and if we may judge from his intimacy
with laocrates, Plato, and other men of talent, and from the manner
in which others speak of him, he received a moat excellent education ;
but no important particulars are known respecting his earlier life.
The first time that he comes prominently forward iu the history of
his country, was during the war between Thebes and Sparta. In the
year b.c. 375, after the battle of Naxos, the Thebans, who were
threatened with an invasion by the Lacedromonians, requested the
Athenians to avert this danger by sending a fleet round Peloponnesus,
as they had done at the beginning of the Peloponnesian war. The
request was readily complied with, and Timotheus was appointed
commander of a fleet of sixty ships, with which he was to sail round
Peloponnesus and along the western coast of Greece. In this expe-
dition he first took Corcyra, which he treated with the utmost mild-
ness and without making any use of his right as conqueror. The con-
sequence was, that ho had very easy work with Cephalouia and Acar-
nania, and that even Alcetas, king of the Molossians, was induced to
join the Athenian alliance. But while Timotheus waa thus reviving
the power of Athens in that part of Greece, the Lacedajmonians sent
out a fleet against him, under the command of Nicolochus. A battle
was fought near the bay of Alyzia, in which the Spartans were
defeated. Soon after Nicolochus ofiered another battle, but as the
fleet of Timotheus had suffered too much to allow him to accept it,
Nicolochus raised a trophy. But Timotheus soon restored his fleet,
which was increased by reinforcements of the allies to seventy ships,
against which Nicolochus could not venture anything. The original
object of the expedition however was now accomplished, as the
Spartans had not been able to make their projected invasion of Boootia,
and Thebes was thus enabled to direct her forces against the Boeotian
towns which asserted their independence. Timotheus at the head of
hia large fleet had no means of maintaining it, for Thebes herself had
contributed nothing towards it, and Athens, which waa not iu a very
prosperous condition, had been obliged to bear all the expenses of the
fleet, with the exception of what Timotheus himself had furnished
from his private purse. Athens therefore concluded a sepai'ate peace
with Sparta, and sent orders to Timotheus to i*eturn home. On his
way thither he landed at Zacjnthus a body of exiles who probably
belonged to the democratieal party of the place, and who had sought
his protection. He provided them with the means of opposing and
annoying their enemies, the oligarchical party of Zacyntbus, which
was in alliance with Sparta. The oligarchs sent envoys to Sparta
to complain, and Sparta sent envoys to Athens to remonstrate
against the conduct of her admiraL But no satisfaction waa given, as
the Athenians would not sacrifice the Zacynthian exiles for the purpose
of maintaining the peace. The Spartans therefore looked upon the
peace as broken, and prepared for new hostilities.
Soon after these occurrencea Corcyra was hard pressed by the
Peloponnesian fleet, and implored the Atheniana for protection. Timo-
theus, who, on hia former expedition, had given such great proofs of
skill and talent, was again entrusted with the command of sixty ships.
But Athens, which was itself in great financial difficulties, had not the
means to equip them, and Timotheus in the spring of B.C. 373 sailed
to the coasts and islands of the ^gean to request the Athenian
allies to provide him with the means of assisting the Corcyrajans. He
appears to have received some support from Boeotia (Demosth. ' in
Timoth,,' p. 1188), and in Macedonia he formed friendly relations with
King Amyntas. His proceedings however went on very slowly, and
apparently without much success, for he was of too gentle a disposi-
tion to force the allies to furnish what they could not give conveniently.
At last however he had sailed as far as the island of Calaurea, where
his men began to murmur because they were not paid. The state of
affairs in Corcyra had grown worse every day. His enemies at Athena
seized upon the slowness of his progress as a favourable opportuuity
for aiming a blow at him. Iphicratea and Callistratus came forward
to accuse him, whereupon he was recalled, and the command of his
fleet given to his accusers and Chabrias. His trial was deferred till
late in the autumn ; but he was acquitted, not indeed on account of
his innocence, though it was well attested, but on account of tho inter-
ference of Alcetas, the Molossian, and Jason of Pherae, who had come
to Athens to protect him.
In B.C. 361, after the removal of his rival Iphicrates, Timotheus
received the command of the fleet on the coast of Macedonia. He
took Potidsea and Torone from Olynthus, and these conquests were
followed by the reduction of all the Chalcidian towns. From thence
he proceeded to the Hellespont, where, with the assistance of Ario-
barzanes, he again gained possession of several towns. In the year
following he commenced his operations against Amphipolis, in which
however he had no success at all, probably on account of the inter-
ference of the Macedonians, who supported the town, and Timotheus
was nearly compelled to take to flight.
In the year B.c. 357 Timotheus and Iphicrates, who had for some
time been reconciled to each other through the marriage between a
daughter of the former and a son of the latter, obtained the command
of a fleet of 60 sail against the rebellious allies of Athens, especially
against Samos. But the Athenian arms were unsuccessful, and a
treaty was concluded between the belligerents, which put an end to
the Social War. The Athenian generals however, Timotheus, Iphi-
crates, and Menestheus, were charged with having caused the ill-luck
of the Athenians, and brought to trial. Timotheus in particular was
accused of having received bribes from the Chians and Rhodians.
His colleagues, who were themselves in the greatest danger, were so
convinced of his innocence, that they declared they were willing to
take all the responsibility upon themselves. But he was nevertheless
condemned to pay a fine of 100 talents. As he was unable to pay the
73
TIMOTHY.
TIMOTHY.
74
sum, he withdrew to Chalois in Euboea, where he died soon after, in
B.C. 354. The injustice of this sentence was tacitly acknowledged by
the Athenians after the death of Timotheus, by the manner in which
his son Conon was allowed to settle the debt of his father : nine-tenths
of the penalty were remitted, and the other tenth Conon was per-
mitted to expend in repairing the city walls.
Timotheus was no less distinguished as a man than as a general.
He was of a very humane and disinterested character. He sacrificed
all his property in the service of his country, while other men of his
age used public offices only as a means of enriching themselves.
When Alcetas and Jason came to Athens to protect him, they lodged
in his house, at which time he was so poor, that he was obliged to
borrow furniture to receive his illustiious friends in a manner worthy
of their station. Even his enemies, when they came to know him,
could not help feeling attachment and esteem for him.
(Xenophon, Bellen., v, 4, 63, &c., vi. 2, 11, &c,; Isocrates, De Per-
mutatione ; C. Nepos, Timotheus ; Diodorus Sic, xv. and xvi. ; com-
pare Thirlwall and Qrote, Histories of Greece.)
TIMOTHY, to whom the Epistles of St. Paul, known by his name,
are addressed, was a native of Lystra, a city of Lycaonia, in Asia
Minor. His father was a Greek, or Gentile, but his mother, Eunice,
was a Jewess. Both his mother and grandmother Lois were Christian
believers (2 Timoth., i. 5), who were probably converted to the faith
by the preaching of Paul and Barnabas on the occasion of their first
apostolical journey among the Gentiles. Whether Timothy was him-
self converted by St. Paul or by the teaching of his mother does not
appear ; but it is certain that she had taken great pains with her son's
education, for from a child, as St. Paul says, " he had known the
Holy Scriptures." (2 Timoth., iii. 1 5.) His devotion to his new faith
was so ardent, and the progress he made in the knowledge of the
gospel so great, that he gained the esteem and good word of all his
Christian acquaintance. Accordingly when St. Paul paid his second
visit to Lystra, the believers both of that city and Iconium commended
him so highly to Paul, that he " would have Timothy go forth with
him " as the companion of his travels. Previously to commencing
them however St. Paul circumcised Timothy, " because of the Jews,"
who were numerous and powerful in those parts and likely to take
offence at the preaching and ministration of an uncircumcised teacher.
(Acts, xvi. 1-3.) He was then solemnly admitted and set apart to the
office of an evangelist, or preacher of the gospel, by the elders of
Lystra and St. Paul himself laying their hands upon him (1 Tim., iv.
14 ; 2 Tim. i. 6), though he was probably not more than twenty years
of age at the time. From this period (a.d. 46) mention is frequently
made of Timothy as the companion of St. Paul in his journeys, as
assisting him in preaching the gospel, and in conveying his instructions
to the different Christian churches. His first mission was in company
with St. Paul and Silas, when they visited the churches of Phrygia
and delivered to them the decrees of the council of elders at Jerusa-
lem, by which the Gentiles were released from the obedience to the
law of Moses as a requisite for salvation. From Phrygia he proceeded
in the same company to Troas, and thence to Macedonia, where he
assisted in founding the churches of Philippi, Thessalonica, and Beroea,
at the last of which cities he and Silas were left when St. Paul was
driven from Macedonia by the persecution of the Jews in that country
and retired to Athens. In this city St. Paul was subsequently joined
by Timothy (1 Thess., iii. 1), who gave him such an account of the
afflicted state of the Thessalonian Christians as induced him to send
Timothy back to " establish and comfort them, concerning their faith :"
a charge both of difficulty and danger. From Athens St. Paul went
to Corinth, where he was joined by Timothy and Silvanus, who both
assisted him in converting the Corinthians and establishing the
Corinthian church, for a period of a year and a half. (2 Cor., i.)
When St. Paul left Corinth, Timothy appears to have accompanied
him on his return to Asia, where they resided nearly three years,
without interruption, except during the visit of St. Paul to Jerusalem,
to keep the feast there, in which however it does not appear that he
was accompanied by Timothy. Towards the expiration of their
i-esidence at Ephesus, St. Paul despatched Timothy and Erastus
together to precede himself on a journey to Macedonia. (Acts, xix.
22.) It would also seem (1 Cor., iv. 17) that St. Paul at the same time
charged Timothy to visit the church of Corinth. On returning from
Corinth to Macedonia, Timothy was joined by St. Paul from Ephesus,
and henceforward they were frequently together, till Timothy was
appointed by St. Paul to govern the Church of Ephesus. In the in- '
terval between St. Paul's joining Timothy in Macedonia and the
appointment of the latter to the superintendence of the Church at
Ephesus, Timothy appears either to have accompanied St. Paul on his
first journey to Rome, or to have visited him there. St. Paul, as is
well known, was a prisoner at Rome, though under but little restraint,
and from Hebrews (xiii. 23) we may conclude that Timothy also suf-
fered imprisonment either at Rome or elsewhere in Italy; and that
he was released before St. Paul left that city. The subsequent history
of St. Paul and Timothy is not clearly given either in the Acts of the
Apostles or the Epistles of the New Testament ; but it is reasonable
to suppose that when they were both set at liberty, they renewed the
journeys made for founding new churches and revisiting old. (See
Hebrews, xiii. 23; Philipp., i. 1 ; ii. 19; 1 Tim., i. 3.)
Timothy was eventually left with the charge of the Church at
long Timothy exercised this office is not known, nor can we determine
the time of his death. An ecclesiastical tradition relates that he
suffered martyrdom, being killed with stones and cluba (a.d. 97) while
he was preaching against idolatry in the neighbourhood of the temple
of Diana at Ephesus. His supposed relics were removed to CoDBtau-
tinople, with great pomp, in 356, in the reign of the Emperor Con-
stantine. Shortly after Timothy's appointment to the superintendence
of the Church of Ephesus, St. Paul wrote to him his first Epistle ;
the date of which was probably about a.d. 64, after St. Paul's first
imprisonment at Rome. Some critics indeed assign to it as early a
date as 66, supporting their opinion by 1 Tim. L 3, from which it
appears (1.) that Timothy was in Ephesus when the Apostle wrote his
first letter to him ; (2.), that he had been left there when Paul was
going from Ephesus into Macedonia. A careful examination however
of the narrative in the Acts will convince the reader that the contem-
plated journey into Macedonia, of which the Apostle speaks (1 Tim.
i. 3), is some journey not mentioned in the Acts, and therefore subse-
quent to St. Paul's release from his first confinement at Rome. But
whatever doubt there may be as to the date of the first, there is none
about the genuineness of either of the two Epistles to Timothy.
They have always been acknowledged to be the undisputed production
of the Apostle Paul. The object and design of the First Epistle to
Timothy were such as we might have expected from the relation
between St. Paul the writer, and Timothy, to whom it was addiessed.
It was written with the view of guiding and directing Timothy in hia
responsible and difficult ministry as the head of the Church at Ephe-
sus, to instruct in the choice and ordination of proper officers, and to
warn him against the false teachers (Michaelis thinks they were
Esseues) wh o had " turned aside " from the simplicity of the gospel,
to idle controversies and " endless genealogies," and who, setting them-
selves up as teachers of the Law of Moses, had insisted upon the
necessity of obedience to it as a requisite for salvation.
The Epistle was written from Nicopolis in Macedonia (' Titus,' iii.
12), and not from Laodicea, as the subscription informs us. The
undesigned coincidences between it and the Acts of the Apostles are
given in Paley's ' Horse Pauliuae,' p. 323-338.
The Second Epistle of Paul to Timothy appears from chap, i., vera.
8, 12, 17, to have been written by St. Paul while he was a prisoner at
Rome; but whether he wrote it during his first imprisonment,
recorded in Acts, xxviii., or during a second imprisonment, has been
much questioned. According to the uniform tradition of the ancient
church, it was written during the second confinement. The modern
critics, who refer it to the time of the first, are for the most part anti-
episcopalians or Romanists : the former being concerned to deny the
permanency of Timothy's charge at Ephesus ; the latter not knowing
how to account for the omission of Peter's name in the salutations
from Rome. The arguments adduced by Macknight (Preface to 2
Timothy) in support of the opinion of the ancient church are, we
think, conclusive. St. Paul, it is generally agreed, returned to Rome
after his first imprisonment, early in 65 ; where, after being kept in
bonds as an * evil-doer ' for more than a year, he is believed to have
sufi"ered martyrdom, in 66. As therefore the Apostle requests
Timothy (iv. 21) to come to him at Rome before winter, it was pro-
bably written in July or August, a.d. 65 ; and it is generally supposed
that Timothy was at Ephesus when St. Paul addressed it to him.
The immediate design of St. Paul in writing this Epistle was, it
would seem, to apprise Timothy of the circumstances that had recently
happened to himself at Rome, and to request his immediate presence
there. Accordingly we gather from the last chapter of this Epistle,
that St. Paul was closely confined as a malefactor for some crime laid
to his charge ; that when he was brought before the Roman magis-
trates to make his first answer, " no man stood by him, but all men
forsook him; " that only Luke was with him : that being thus deserted
by almost all, he was greatly desirous of seeing Timothy, " his dearly
beloved son in the gospel," before the " time of his departure," which
he knew " was at hand." He therefore requested him to come to
Rome immediately, but being uncertain whether he should live to see
Timothy again, he gave him in this Epistle a variety of admonitions,
charges, and encouragements. This Epistle in fact is an appropriate
and affecting sequel to the first, the principal injunctions and warnings
of which it repeats, but with additional earnestness and fervour. St.
Paul, as if for the last time (chap, i.), conjures Timothy to apply him-
self with all his gifts of grace to his holy work, to hold fast the
doctrine which he had received from him, and not to be ashamed
either of the testimony of the Lord or of St. Paul's own sufferings.
In chnp. iii. St. Paul gives a description of the " perilous times which
should come," and which were to be anticipated by every possible
exertion in performing the duties of a Christian minister. To this .
work, in chap, iv., he exhorted him by a solemn charge before " God
and the Lord Jesus Christ, the judge of the quick and the dead." He
then depicted his own present state, and his presentiment of an
approaching martyrdom ; and after requesting the immediate presence
of Timothy, concluded by sending to him the greeting of some of the
brethren of the Church at Rome. Whether Timothy arrived at Rome in
time to find St. Paul alive, does not anywhere appear : the latest authen-
tic information we have concerning him being given in this letter.
The Epistles to Timothy, in conjunction with those to the Thessa-
76
TIMOR, SULTAN".
TIMUR, SULTAN.
76
lonians and Titus, are extremely valuable, as furniahing very strong
evidence to the truth of many of the facts related in the Acts of the
Apoatles. The undesigned coiDoideuces between the Second Epistle
to Timothy and the Acta are given by Puley, in his ' Hor» Paulinse,'
pp. 339-356. Their value iu another respect is thus described by
Macknight, Preface to 1 Timothy—" These Epistles are likewise of
great use in the church, as they exhibit to Chriatian bishops and
deacons in every age the most perfect idea of the duties of their
functions : teach the manner in which these duties should be per-
formed : describe the qualifications necessary in those who aspire to
■uoh offices, and explain the ends for which they were instituted, and
are still continued iu tlie church."
Tl'MUH, SULTAN, KIAMRAM KOTB-ED-DI'N GURQAN
SA'HEB-KIRA'N JIHA'NGIK, that is "Sultan Timur, the fortunate,
the axis of the faith, the great wolf, the master of time, the conqueror
of the world." Timur, a name which frequently occurs among the
princes of tho Eastern Turks, signifies ' iron ' in the Jagata'i dialect,
and corresponds to the Osmanli ' demur.' Timur was born on the
6th or 25th of Sha'bdn, 736 A.H. (a.d. 1335), at Sebz, a suburb of
Kesh, a town south-east of Samarkand. He was the son of Tdrdghai-
Nowian, who was chief of the Turkish tribe of tho Berlas, which
inhabited the district of Kesh. Timur was descended from a younger
son of Bardam-Khan Behadir, or Baghatur, whose eldest son, Yessugai,
was the father of Genghis-Rlian, and he was a direct descendanrt of
Qenghis-Khan on the female side. He was consequently of Mongol
origin, and, being of royal blood, he held a high rank among that
Mongol nobility which w«a founded by Genghis-Khan among the
Eastern Turks. This rank is expressed by the title Nowian, which
was added to the name of his father. Yet the power of his family
was not great. Timur was a soldier at the age of twelve year.^, and
he spent his youth in the continental feuds between the nobles of
those different kingdoms and principalities into which the empire of
Genghis-Khan was divided by his successors. After the death of his
father, his uncle Seifeddin became chief of the Berlas, being the eldtst
of the family ; but a war having broken out between Husein, khan of
Northern Khorrfsrfa, and Mawerainnehr (Mawar-el-nahr), or Jagatai,
and Timur-Togluk, khan of the Getes (Getse), in Northern Turkistau,
young Timur actively supported Husein, and was appointed chief of
the tribe of the Berlas in A.H. 763 (a.d. 1361). In this war Timur
received a wound in the thigh, in consequence of which he became
lame. From this he was called Timur-lenk, or the lame Timur, which
has been corrupted by Europeans into Tamerlane, by which name
Timur is as wtU known in Europe as by his real name. Husein
rewarded him also with the hand of his sister Turkan, a.h. 765 (a.d.
1363). Notwithstanding these favours Timur intrigued against his pro-
tector ; and after the death of his wife he openly rebelled against him,
A.H. 767 (a.d. 1365). With a body of only 250 horsemen he surprised
and took Nakhshab, a town which was defended by a garrison of
12,000 men, among whom there were most probably a great number
of traitors. In a.h. 768 (a.d. 1366) he defeated Husein near his
capital, Balkh, and this prince was murdered by some emirs, who,
seeing their former master forsaken by fortune, endeavoured to obtain
the favour of Timur by putting his rival to death. Balkh, which
was defended by the adherents of Husein, was taken by storm and
destroyed by fire after a siege of three years, a.h. 771 (a.d. 1369), and
Timur was proclaimed khan of Jagatai in the same year by the Kurul-
tai, or the general assembly of the people. He chose Samarkand for
his capital, Husein-Sofi, khan of Kowaresm (Khiwa), having im-
prisqped Timur's ambassadors, was attacked by Timur, who, after five
campaigns, at last succeeded in taking the town of Kowaresm, in a.h.
781 (A.D. 1379). The town was destroyed, and the principal inhabi-
tants, especially artists and scholars, were transplanted to Kesl), which
became the second capital of Timur's empire. Previously to this the
khan of the Getes, who was master of the country between the Sihun,
or Jaxartes, and the Irtish, had likewise been compelled to pay
homage to Timur, who thus became master of a part of Siberia and
of the whole country which we now call Turkistan, and which was
formerly known by the name of Great Tartary. After these conquests
Timur thought himself strong enough to carry into effect the plan of
making himstlf master of all those countries which had once obeyed
his ancestor Genghis-Khan. He first attacked Khordsdn, on the
north-eastern part of Persia, which was then divided between Gaiyjtth-
ed-din-Pir-'Ali, who resided at Herat, and Kojah-'Ali-Murjid, whose
capital was Sebsewftr. Kojah-'Ali Murjid, whose dominions were on
the boundaries of Jagatai, paid homage to Timur as soon as he was
summoned, but the master of Herat prepared a vigorous resistance.
Timur took Herat by storm, but did not destroy it. He carried off as
his only trophy the iron gates of this town, which were noted for their
• beautiful workmanship, and which he ordered to be transported to his
birthplace, Kesh. The larger towns of Khorstsiln surrendered without
resistance, and Timur was only checked by several strong fortresses,
such as Shabnrkiin, Kabushdn, and especially Kdhktlha, between
Balkh and Kelat, in the mountains of the Hicdu-Kush. When these
fortresses fell, all Khordsiin was under his yoke. The inhabitants of
Sebsewdr having revolted, Timur took the town by storm : two thou-
sand of the inhabitants were placed alive one upon the other, till they
formed a mass like a tower, and each layer of human beings was
fastened to the rest by mortar, as if they were so many bricks.
Beginning his career at an age when other conquerors are satisfied
with their laurels, Timur had employed twenty years in reflecting on
the principles of warfare. He led his armies with the prudent bold-
ness of an experienced general, but not with the superiority of genius.
The differences between the numerous successors of Genghis-Khan
enabled Timur to attack them one after another, and each was pleased
with the fall of his rivals. He employed the same policy in his war
against Persia. This country was governed by several princes. Shah-
Sneja, of the dynasty of Mozaffer, who reigned in Pars and Southern
Irdk, or in that part of Persia which was most exposed to any army
from the east, submitted to Timur without resistance. The Sultan
Ahmed, of the house of the Ilkhans, the master of Northern Irdk and
Azerbijan, or Western Persia, had alone to sustain the attacks of the
Tatars, a.h. 788 (a.d. 1386). Timur entered the dominions of Ahmed
by following the coast of the Caspian Sea. In one campaign he con-
quered the provinces of Mazanderdn, Rei, and Rustemdar, and took
the towns of Sultania, Tabris, and Nakhshiwdn. He crossed the
Araxes at Julfa on a magnificent bridge, which was strongly fortified
on both sides, but which is now destroyed. Kars, now the key of
Eastern Turkey, fell into his hands ; Tiflis surrendered, and the Prince
of Georgia purchased his protection by adopting the Mohammedan
faith. The prince of Shirwdn sent tribute to the camp of Timur, nine
pieces of each thing sent (nine was a holy number among the Mongol
princes), but only eight slaves; the ninth was himself. On these
terms be was allowed to remain in possession of his dominions.
Taherten, king of Armenia, submitted to Timur without any resist-
ance ; but Kdrd-Ytisuf, prince of Diyarbekir, and master of the country
round Lake Wan, prepared to defend himself. A body of Timur's
army marched against him, and took the fortresses of Akhlat and
Adiljuwdz by storm ; and Timur himself conducted the siege of Wan.
This famous fortress fell after a siege of twenty days, the garrison was
cast from the steep rock on which this town is situated, and the forti-
fications were razed by ten thousand miners and pioneers. Ready to
cross the Carduchian Mountains and to descend into the valley of the
Upper Tigris, Timur was obliged, by a revolt of the inhabitants of
Ispahan, to march suddenly to Southern Persia. He took Ispahan by
a general assault : he spared the lives and the houses of artists and
scholars, but the remainder of the city was destroyed, and the
inhabitants were massacred. More than 70,000 heads were laid at
the feet of the conqueror, who ordered his soldiers to pile them up
on the public places of the town, a.h, 789 (a.d. 1387).
Satisfied with having conquered the greater part of Persia, Timur
turned his arms towards the north, and overran the kingdom of Kipt-
ahak, which was then governed by Toktamish-Khan. Tliis war lasted
from A.H. 789 to 799 (a.d. 1387 to 1396), We shall here only mention
the march of Timur in the campaign of a.h. 793 (a.d. 1391). Accord-
ing to Sheref-ed-din, Timur started from Tashkend, on the Jaxartes,
on the 13th of Safer, a.h. 793 (19th of January 1391). He marched in
a northern direction, and passed by Kdrd-suma, Ydzi, Kdrd-chuk, and
Sabrdn, until he reached Sdrik-Uzen, on the river Arch : thence he
proceeded as far as Mount Kuchuk-dagh, and subsequently crossed
Movmt Ulu-dngh, or the range of the Altai. He then took a north-
western direction until he reached the upper part of the river Tobol
in Siberia, and thfence proceeded westward, crossing the Ural Moun-
tains, and the upper part of the river Ural, or Yaik, where he drew
up his army on the banks of the Bielaya, a southern tributary of the
Kama, which flows into the Wolga, Toktamish, who awaited Timur
in the environs of Orenburg, was not a little astonished to find Idm so
far advanced towards the north ; but being informed of his having
taken that direction, ho hastened to the country of the Bielaya (Bash-
kiria), and fought that dreadful battle which took place on the loth
of Rejeb, a.h. 793 (18th of June 1391), in which his whole army was
slaughtered.
In the following year (a.h, 794 ; a.d. 1392) Timur returned to his
residence at Samarkand, and he left the war with Kiptshak to his
lieutenants; he only appeared in the field in a.h. 797 (a.d. 1315) in
order to stop the progress of Toktamish in the Caucasian countries.
Meanwhile troubles broke out in northern Persia, which were put down
by Timur's generals, who committed unheard-of cruelties, especially
in the town of Amul, where the whole tribe of the Fedayis was mas-
sacred. Timur himself attacked Southern Persia after his first return
from Kiptshak. The country of Fars was governed by several princes
of the dynasty of Mozaffer, vassals of Timur, who aimed at independ-
ence. After having occupied Loristdn, Timur entered Fars by the
mountain-pasees east of Shiraz, which were defended by the stronghold
of Kalai-zefid ; but this fortress an<i the capital Shiraz were taken, the
princes were put to death or fell in battle, and Timur's son MirtJn-Shah
was invested with the government of Far.s and Khuzistdu. From
Shiraz Timur marched westwards to attack the King of Baghdad, Ahmed
Jelair, of the house of llkhan. Baghdad surrendered without resistance,
and Sultan Ahmed and his family fled towards the Euphrates, accom-
panied by a small body of cavalry, Timur and forty-five emirs
mounted on the swiftest Arabian horses pursued the Sultan, and came
up with him before he had reached the Euphrates. In the engagement
which ensued Ahmed was again defeated and compelled to fly, leaving
his harem and one of his sons in the hands of the victor. The scholars
and artists of Baghdad were transplanted to Samarkand ; Timur
remained at Baghdad for two months, allowing bo little licence to his
>,^JL
77
TIMUB, SULTAN.
TIMUE, SULTAN.
71
Boldiers that he ordered all the wine which was found in the town to
be thrown into the Tigris.
During this time Kdrfi-Yuauf, prince of Diyarbekir, had recovered
part of those districts round Lake Wan which Timur had taken from
him in a former campaign; and several princes in Armenia and
Oeorgia were still independent. Timur resolved to bring them to
submission, and after having succeeded in this, to attack the king-
dom of Kiptshak on its boundaries in the Caucasus. Starting from
Baghdad in a.u. 797 (a.d. 1394), he marched to the Upper Tigris by
Tekrit, Koha or Edessa, Ho-su, and Keif, all situated in Mesopotamia.
He laid siege to Mardin, a strong place in the mountain-passes south-
east of Diyarbekir, but not being able to take it, he contented himself
with the promise of an annual tribute which Sultan Iza, the master of
Mardin, engaged to pay, and he marched to Diyarbekir. This town
was taken and plundered. From Diyarbekir Timur marched to
Akhlat, north of Lake Wan, crossing the mountains, as it seems, by
the passes of the Bedlis, or Centrites. . After having subdued all
Armenia and Georgia, Timur reached the river Terek in the Caucasus,
and there fought another bloody battle with the Khan of Kiptshak.
In A.D. 1395 and 1396 Timur conquered all Kiptshak, and penetrated
as far as Moscow, whereupon he left the command of these countries
to his lieutenants, and returned to Samarkand, in order to prepare for
a campaign against India.
Alter the death of Firus-Shah, the master of India between the
Indus and the Ganges, several pretenders made claim to the vacant
throne. At last Mahmud succeeded in making himself master of
Delhi, and in establishing his authority over all the empire of Firus-
.Shah. Under the pretext of supporting the rivals of MahmuH,
Timur declared war against India ; and such was the renown of his
name, that ambassadors from all the countries of the East arrived at
Samarkand and congratulated him on his new conquests before he had
obtained any triumph. Timur left his capital in A.n. 801 (a.d. 1398).
He took his way through the passes in the Ghur Mountains, or the
western part of the Hiudu-Kush ; and on the 8th of Moharrem, a.h.
801 (19th of September 1398), he crossed the Indus at Attock, where
pelled to give up his plan of advancing farther. Timur traversed the
Punjab in a direction from north-west to south-east, crossing the
rivers Behut, Chunab, Ravee, the Beeah, the Hyphasis of the ancients,
where Alexander terminated his conquests, and the Sutlej, the eastern-
most of the five great rivers of the Punjab. Although no great battle
soners ; aud as their number daily increased, Timur ordered them all
to be massacred, to prevent any mutiny, which might have become
fatal to him in case of a defeat. At last the Indian army was defeated
in a battle near Delhi, aud this town, with all its immense treasures,
fell into the hands of the conqueror. Delhi was plundered, and a part
of it was destroyed, the inhabitants having set fire to their houses,
and thrown themselves and their wives and children into the flames.
Several thousands of artists and skilful workmen were transplanted to
Samarkand, Timur pursued the army of Mahmud as far as the
sources of the Ganges, and after having established his authority in
the conquered countries, returned to Samarkand in the same year in
which he had set out for the conquest of India.
Meanwhile troubles had broken out between the vassal princes in
Persia and the countries west of it; and Timur's own sous, who were
governors of this part of the empire, had attacked each other, and one
of them was accused of having made an attempt to poison his brother.
These events became as many occasions of new conquests for Timur,
who overran the whole country between Persia and Syria. Siwas
(Sebaste), one of the strongest towns of Asia Minor, which belonged to
the Oamanlis, was taken after a siege of eighteen days. The Moham-
medan inhabitants were spared; the Christians, I among whom were
uiord than 4000 Armenian horsemen, were interred alive, (a.h. 803 ;
A.D. 1400.) Among the prisoners was Ertoghrul, the son of Bayazid,
sultan of the Osmaulis, who defended the town for his fathei', and
who was put to death after a short captivity. The fall of Siwas aud
the murder of Ertoghrul were the signals for war between Timur and
Bayazid, who had filled Europe with the terror of his name, and who
was then besieging Constantinople. The rapidity of his marches and
the impetuosity of his chai'ges had procured him the surname of
' llderim,' or the ' Lightning ; ' and accustomed to victories over the
knights of Hungary, Poland, France, and Germany, he did not dread
the Tatars of Timur. Previously to the siege of Siwas, he had,
negociated with Timur about some Turkish emirs in Asia Minor, aud
especially about Taherten, king of Armenia, a vassal of Timur, who
had been deprived by Bayazid of several of their best towns, and
whom Timur protected. To humble his pride, Bayazid imprisoned
the Tatarian ambassadors, and Timur in revenge carried devastation
into the dominions of the Osmanlis.
Before Bayazid had crossed the Bosporus, Timur, offended by
Ferruj, sultan of Egypt, overran Syria, then a dependence of Egypt.
The army of Ferruj was routed with dreadful slaughter at Haleb, aud
this populous town was taken by the Tatars, who entered it with the
flying Egyptians. Plunder, bloodshed, and cruelties signalised this
new conquest (11th to 14th of Rebuil-ewwal, a.h. 803; 30th of Octo-
ber to 2nd November, a.d. 1400), which was followed by the fall of
Damascus (9th of Sha'b^n, a.h. 803; 25th of March 1401). Artists
and workmen were as usual carried off to Samarkand and other towns
of Turkistan. Ferruj became a vassal of the Tatars, Baghdad having
revolted, Timur took it by storm on the 27th of Zilkide, a.h. 803 (9th
of July A.D, 1401), and 90,000 human heads were piled up on the
public places of the town.
Hitherto negociations had still been carried on between Timur and
although not very numerous army. But Bayazid having discovered
that Timur had bribed several regiments of Turkomans that were in
the army of the Osmanlis, the negociations were broken off, and the
two greatest conquerors of their time advanced to meet each other in
the field.
bled his army near Haleb, aud, crossing the range of the Taurus, he had
proceeded north-westward, to the northern part of Anatolia. At
Angora he met with Bayazid. The battle, one of the most eventful
which have ever been fought, took place on the 19th of Zilhije, a.h.
804 (20th of July, a.d. 1402). After an obstinate resistance the
Osmanlis, who were much less numerous than the Tatars, were
routed. Old Bayazid, to whom flight was unknown, despised every
opportunity of saving himself, and so strong was the habit of victory
in him, that he could not conceive his defeat even when he saw the
general rout of his warriors. At the head of his janissaries, Bayazid
maintained himself on the top of a hill ; his soldiers died of thirst or
fell by the sword and the arrows of the Tatars ; at last he was almost
alone. When the night came he tried to escape ; his horse fell, and
Bayazid was made a prisoner by the hand of Mahmud Khan, a
descendant of Genghis Khan, and who was under-khan of Jagataii,
One of bis sons, Muza, was likewise made prisoner ; another, Mustafa,
fell most probably in the battle, for he was never more heard of;
three others, Soliman, Mohammed, and Iza, escaped with part of their
troops. Timur received his royal prisoner with kindness and gene-
rosity. Afterwards, when some faithful Osmanlis tried to save their
master, he was put into chains, but only at night. Accompanying
Timur on his march, he sat in a ' kafes,' that is, in* a sedan hanging
between two horses, and this was probably the origin of the story that
Timur had put Bayazid in an iron ' cage' like a wild beast, a story
which has chiefly been propagated by Arabshah aud the Byzantine
Phranzes (i., c, 26). Bayazid died in his captivity at Akshehr, about
a year [after the battle of Angora (14th of Sha'ban, a.h. 805 (8th of
March, a.d. 1403), and Timur allowed Prince Muza to carry the body
of his father to Brusa.
The sons of Timur pursued the sons of Bayazid as far as the Bospo-
rus, but having no fleet, they did not cross this channel. They ravaged
the country, and afterwards joined their father Timur, who with the
main body of his army took Ephesus and laid siege to Smyrna. This
town, which belonged to the Knights of St. John at Rhodes, fell after a
gallant resistance, in the month of December 1402. However, the
conquest of Asia Minor from the Osmanlis was only a temporary
triumph, for a short time afterwards it was recovered by Mohammed I.,
the son and successor of Bayazid, After having thus carried his arms
as far as the shore of the Ionian Sea, Timur withdrew to Persia to
quell an insurrection, and then retired to Samarkand, He was pre-
paring for the conquest of China, but he died on his march to that
country, at Oti'ar on the Jaxartes, on the 17th of Sha'bfln, a.h. 807
(19th of February 1405), in his seventy-first year, after a reign of
thirty-six years, leaving thirty-six sons and grandsons, and seventeen
grand-daughters. A considerable part of Timur's western and northern
conquests, Asia Minor, Baghdad, Syria, Georgia, Armenia, and the whole
kingdom of Kiptshak, were lost by his successors almost immediately
after his death. In Persia and Jagata'i his descendants reigned for a
century ; and for three centuries they ruled over Northern India
under the name of the Great Moguls.
Timur has been compared with Alexander, but he is far below him.
It is true, that except in India, Alexander found only effeminate
nations on his way, while Timur fought with the most warlike nations
of the world ; but the enemies of Alexander formed great political
bodies which were governed by one absolute master, while the warlike
nations which were subdued by Timur were divided into a multitude
of tribes and governed by numerous princes, each of whom was
jealous of his neighbour. Timur overran the territory of two mighty
nations, the Turks-Osmanlis, and the Tatars of Kiptshak, but he was
not able to subdue them. Both Alexander and Timur protected the
arts and sciences, but Timur could only transplant them by force
from one place to another, while poets and scholara flocked to
Alexander because he could appreciate their talents. Timm-'s cruelty
was the consequence of his savage and barbarous temper; Alexander
only forgot the laws of humanity when he was overpowered by wine
or by passion. Timur was a man of extraordinary talents, who accom-
plished great things after long experience and severe struggles;
Alexander, a true genius, came, saw, and vanquished. The greatness
of Timur inspires awe, and we shrink from it with horror ; the great-
ness of Alexander attracts us because it is adorned with the amiable
qualities of his character.
The life of Timur is the subject of many valuable works. Sheref-
ed-din-'Ali wrote the history of Timur in Persian, which has been
translated into French by P^tis de la Croix, under the title ' Histoire
de Timur-Bec, connu sous le nom du Grand Tamerlan,' &a, Paris,
79
TINDAL, MATTHEW, LL.D.
TINDAL, MATTHEW, LL.D.
80
1722. This is the best work concemiug Timur, although the author
often flatters. Arabshah, a Syrian, on the contrary, depreciates the
character of Timur; his history, or rather Ids epic, has been trans-
lated under the title •Ahmedis Arabsiadae Vitao et Rerum Gestarum
Timuri qui vulgo Tamerlanes dicitur, Historia,' Lugduni-Batavorum,
1636. Longdit, Argote de Molina, Petrus Perundinus Pratensis,
Boekler, Richerius, &c. have also written the life of Timur. Among
the Byzantines, Ducas, Chalcondylas, and Phranzos contain many
valuable accountB, though Phranzes is less critical than the others. A
very interesting book is ' Scbildtberger eino Wunderbarliche und
Kurzweilige Histoire,' Ac, 4to. The same book was translated into
modem German by Penzel, Munchen, 1813. Scbildtberger, a German
Boldier, wan made prisoner by the Turks in the battle of Nicopolis
(1396), when he was only sixteen years old. In the battle of Angora
he was taken by the Tatars, and became a kind of secretary to Shah-
rokh and Miran-Shah, the sons of Timur. He finally returned to
Germany in 1427, after a captivity of thirty years, and then wrote the
Gibbon gives a splendid view of Timur's conquests in the ' Decline
and Fall,' chap. Ixv. Another most valuable work is Clavijo, ' Historia
del gran Tamerlan, e Itinerario,' &c, Clavijo, ambassador of King
Henry III. of Castile at the court of Timur, was present at the battle
of Angora. (Desguignes, ' Histoire des Huns,' vol. ii.) Timur may
be considered as the author of the * Tufukat, or the Code of Laws.'
This work was originally written in the East-Turkish language, and was
translated into Persian. The Persian version, with the English trans-
lation and a most valuable index, was published by Major Davy and
Professor White, 4 to, Oxford, 1783 ; another version with a full biblio-
Stewart, late professor of Oriental languages in the East India Com-
pany's College, under the title of * The Mulfuzat Timur, or Autobio-
graphical Memoirs of the Moghul Emperor Timur,' 8vo, 1830; and
the late Professor Langles translated the Persian version into French,
under the title, * Instituts Politiques et Militaires de Tamerlan,' Pari?,
1787. This work is of great importance for the history of Timur; we
see that this Tatarian conqueror was provided with maps and works
concerning geography, which were composed by his order.
TINDAL, MATTHEW, LL.D., was the son of the Rev. John
Tindal, parish clergyman at Beer-Ferres in Devonshire, where Matthew
was bom about the year 1657. In 1672 he was admitted of Lincoln
College, Oxford, where Dr. Hickes was his tutor ; but he afterwards
removed to Exeter College, and he was finally elected to a law fellow-
ship at All Souls, soon after he had taken his degree of B.A. in 1676.
He proceeded LL.B. in 1679, and was created LL.D. in 1685. If we
naay believe certain charges which were long afterwards made in print
by the opponents of his theological opinions, his debaucheries while
he resided at Oxford were so scandalous as to have drawn down upon
him on one occasion a public reprimand from his college. Soon after
he obtained his Doctor's degree he went over to the Church of Rome,
not without subjecting himself to the imputation of having an eye to
the worldly advantages which such a step might seem to promise
under the popish king just come to the throne. It does not appear
however that he actually obtained any court favour or patronage by
his change of religion ; and, according to his own account, given in a
pamphlet he published in his own defence in 1708, he reverted to the
Church of England some months before the revolution, having attended
mass for the last time at Candlemas 1688, and publicly received the
sacrament in his college chapel at Easter following. He asserts that
his mind, which cauje a tabula rasa to the university, had been
prepared for being seduced by James's Romish emissaries by the
notions as to the high and independent powers of the clergy which
Accordingly, when he threw off Popery, he abandoned his high church
principles at the same time; or rather, as he puts it, he discovered
that these principles were unfounded, and that at once cured him of
his Popery. " Meeting," he says, " upon his going into the world,
with people who treated that notion of the independent power as it
deserved, and finding the absurdities of Popery to be much greater at
hand than they appeared at a distance, he began to examine the whole
matter with all the attention he was capable of ; and then he quickly
found, and was surprised at the discovery, that all his till then
undoubted maxims were so far from having any solid foundation, that
they were built on as great a contradiction as can be, that of two
independent powers in the same society. Upon this he returned, as
ho had good reason, to the Church of England, which he found, by
examining into her constitution, disclaimed all that independent power
he had been bred up to the belief of." The revolution having taken
place, he now also, naturally enough, became a zealous partisan of that
settlement. The history of the rest of his life, during which he
appears to have resided mostly in London, consists almost entirely of
that of his successive publications and of the controversies in which
they involved him.
He first appeared as an author in November 1693, by the publi-
cation, in 4to, of ' An Essay concerning Obedience to the Supreme
Powers, and the Duty of Subjects in all Revolutions, with some con-
siderations concerning the present juncture of afiairs.' This was
followed in March 1694 by ' An Essay concerning the Law of Nations
and the Rights of Sovereigns,' a second edition of which, with addi-
tions, was brought out in the same year. This year also he published
'A Letter to the Clergy of both Universities,' in recommendation of
certain alterations which there was then some talk of making in the
Liturgy ; and in 1695 another pamphlet in support of the same
views. But the first work by which he attracted general attention
was an 8vo volume which he published in 1706, entitled ' The Rights
of the Christian Church Asserted, against the Romish and all other
priests who claim an independent power over it.' This work, which is
an elaborate attack upon the theory of hierarchical supremacy, or
what are commonly called high-church principles, immediately raised
a vast commotion. It is related that to a friend who found him one
day engaged upon it, pen in hand, he said that he was writing a book
which would make the clergy mad. Replies to it were immediately
old college tutor), and others ; the controversy continued to rage for
several years. A bookseller and his shopman were indicted for selling
the book. In 1707 Tindal published ' A Defence ' of his work, and a
few months after, ' A Second Defence,' both of which he republished
together, with additions, in 1709 : the same year he also reprinted his
two Essays on Obedience and the Law of Nations, along with 'A
Discourse for the Liberty of the Press, and an Essay concerning the
Rights of Mankind in matters of Religion.' About the same time he
came forth with a fresh pamphlet, entitled ' New High Church turned
Old Presbyterian,' in exposure of the pretensions put forward by
Sacheverell and his party ; upon which the House of Commons, which
the day before had condemned Sacheverell's sermons to be burned, on
the 25th of March 1710 impartially ordered Tindal's 'Rights of the
Christian Church,' and the second edition of his two ' Defences,' to be
committed to the flames at the same time. This proceeding drew
from Tindal the same year three more pamphlets— the first entitled
'A High-Church Catechism;' the second, 'The Jacobitism, Perjury,
and Popery of the High-Church Priests;' the third, 'The Merciful
Judgments of High Church triumphant, on Ofi'euding Clergymen and
others, in the reign of Charles I.' The next year, on the Lower House
of Convocation having drawn up and printed 'A Representation of the
present state of Religion, with regard to the late excessive growth of
Infidelity, Heresy, and Profaneness,' Tindal forthwith replied in ' The
Nation Vindicated from the Aspersions cast on it' in the said repre-
sentation. The second part of this performance is occupied with an
explanation and defence of what has since been called the doctrine of
philosophical necessity, in opposition to the assertion of the Convo-
cation, that such views went to overturn the foundations of all
morality, and of all religion, natural as well as revealed. For some
years from this date Tindal's active pen was exclusively occupied with
the politics of the day ; but his performances do not appear to have
been very efiective at the time, and have been long forgotten. It is
remarkable however that in so voluminous a work as Coxe's ' Memoirs
of Sir Robert Walpole,' no notice should be taken of a personal con-
troversy in which Tindal became involved with that minister after his
resignation in 1717, and which produced various pamphlets on both
sides. Tindal considered himself to have been ill-used by Walpole,
who, according to his account, had first courted his alliance, and then
suddenly dropped him after he had so far committed himself in
writing that it was imagined his hostility in print was not to be
dreaded, Walpole, on the other hand, or his friends, accused Tindal
of a treacherous desertion to the opposite faction as soon as he found
that Walpole had been or was about to be deprived of power. It is
probable that there was some misunderstanding on both sides. In
any case this ministerial rupture was merely a personal quarrel, in
which little or no public principle was involved ; and it implies there-
fore no political versatility or inconsistency in Tindal that a few years
after this, in 1721, 1722, and 1723, when Walpole was at the head of
the ministry, he came forward as a strenuous defender of bis govern-
ment in a succession of pamphlets. He did not return to his original
field of theological polemics till 1728, when he published 'An Address
to the Inhabitants of the two great Cities of London and Westminster,'
in reply to a pastoral letter which the Bishop of London, Dr. Gibson,
had addressed to the people of his diocese on the subject of Anthony
Collins's ' Scheme of Literal Prophecy Considered,' and other recent
deistical writings. A ' Second Pastoral Letter,' soon after published
by the bishop, called forth a ' Second Address' from Tindal; and both
addresses were reprinted the same year, in an 8vo volume, with altera-
From this date Tindal seems to have remained quiet till the year
1 730, when he produced, in a 4to volume, the work by which he is
now chiefly remembered, his ' Christianity as Old as the Creation, or
the Gospel a Republication of the Religion of Nature.' The object
of this work, as is indeed sufficiently declared in its title, is to contend
that there is nothing more in Christianity, properly underetood, than
what the human reason is quite capable of discovering for itself, and
by implication to deny that any special revelation has ever been made
by the Deity to man. It did not however contain any express denial
of the truth of Christianity ; of which indeed the author and his
partii'ans rather professed to think that he had found out a new
defence stronger than any that had been previously thought of.
" Tindal," says Warburton, some years after, " a kind of bastard
Socrates, had brought our speculations from heaven to earth ; and,
under pretence of advancing the antiquity of Christianity, laboured to
81
TINDAL, REV. NICHOLAS.
TINTORETTO, JACOPO.
sa
undermine its original." The book made a great noise, and various
answers to it soon appeared, tho most noted of which were — Dr.
Waterland's 'Scripture Vindicated,' 1730; 'The Usefulnocs, Truth,
and Excellency of the Christian Revelation defended,' by Mr. (afterwards
Dr.) James Foster (the eminent Dissenting clergyman), 1731 ; 'A
Defence of Revealed Religion,' by Dr. Conybeare (afterwards bishop of
Bristol), 1732 ; and ' An Answer to Christianity as Old as the Creation,'
by the Rev. John (afterwards Dr.) Leland (another learned and distin-
guished Dissenting divine), 1733. The book ia also discussed iq the
last-mentioned writer's more celebrated work, his 'View of the Prin-
cipal Deistical Writers,' published in 1764. Tindal defended himself
in ' Remarks on Scripture Vindicated, and some other late Writings,'
published along with a new edition of his ' Second Address to the
Inhabitants of London and Westminster,' in 1730, But this was his
last publication : his health now began to give way, and he expired on
the 16th of August 1733, at a lodging in Cold-bath Fields, to which
he had been prevailed upon to remove' a few days before fi'om his
chambers in Gray's Inn. Tindal never held any preferment except
his fellowship ; but it is stated, in the ' Biographia Britaunica,' that in
the reign of King William he frequently sat as judge in the Court of
Delegates, and had a pension of 200^. a year granted to him by the
crown for his services in that capacity. It is added that he " rarely, if
ever, practised as an advocate in the courts of civil or ecclesiastical
law," which would seem to imply that he had been called to the bar,
fact is not mentioned. A new edition of his * Essay on the Law of
Nations' was published the year after his death ; but the publication
of a second part of his ' Christianity as Old as the Creation,' which he
left ready for the press, is said to have b^en prevented by the inter-
ference of Bishop Gibson. A will, in which he left nearly all he had
to Eustace Budgell, in whose hands he was for some time before his
decease, was contrsted by his nephew, the Rev. Nicholas Tindal, and
was at last set aside. The will was printed in a pamphlet, with a
detail of circumstances connected with it, in 1733.
Of the amount of talent and learning shown in Tindal's writings
very different estimates have been formed by his admirers and his
opponents. Waterland, in the Introduction to his ' Scripture Vindi-
cated,' characterises his antagonist in the following tei'ms : — " His
attacks are feeble, his artillery contemptible; he has no erenius or taste
for literature, no acquaintance with the original languages, nor so
much as with common critics or commentators ; several of his
objections are pure English objections, such as affect only our trans-
lation : the rest are of the lowest and most trifling sort." Dr. Conyers
IVIiJdleton, on the other hand, in a letter which he addressed to Water-
land iuimediately after the latter had published his book, says, " For
my own part, to observe our English proverb, and give the devil his
due, I cannot discover any such want of literature as you object to him;
but, on the contrary, see plainly that his work has been the result of
much study and reading; his materials collected from a great variety
of the best writers ; his pages decently crowded with citations ; and
his indt X of authors as numerous as that of most books which have
lately appeared." Tindal's English style is unaffected and perspicuous,
TINDAL, REV. NICHOLAS, was the son of a brother of Dr.
Matthew Tindal, and was born in 1687. Having studied at Exeter
College, Oxford, and taken his degree of M.A. in 1713, he was after-
wards elected a Fellow of Trinity College in that university. In 1722
he was presented by his college to the vicarage of Great Waltham in
Essex ; in 1738 Sir Charles Wager, then first lord of the admiralty, with
whom he appears to have some years before sailed for a short time as
chaplain, appointed him chaplain to Greenwich Hospital ; in 1740 he
is said to have been presented to the rectory of Colbourne in the Isle
of Wight, upon which he resigned Great Waltham ; and very soon
after he appears to have obtained his last preferment, the rectory of
Alverstoke in Hampshire, from the bishop of Winchester (Hoadley).
He died at Greenwich Hospital on the 27th of June 1774.
Mr. Tindal's first literary attempt was a work published in monthly
numbers in 1724, under the title of * Antiquities, Sacred and Profane,
being a Dissertation on the excellency of the History of the Hebrews,'
&c., which is described as a translation from the French of Calmet.
This was followed by two numbers of a History of Essex, which was
then dropped. He then engaged in his most memorable undertaking,
the translation, from the French, of Rapin's ' History of England,'
which appeared in a succession of octavo volumes in 1726 and follow-
ing years, and was reprinted in two volumes folio in 1732. This
second edition was dedicated to Frederick, prince of Wales, who in
return presented the translator with a gold medal of the value of
forty guineas. In 1744 a Continuation of Rapin, by Tindal, began to
be published in weekly folio numbers, which was completed in two
volumes (commonly bound in three), in 1747, the history being
brought down to the end of the reign of George I. A second folio
edition of this Continuation appeared in 1751, and a third, in 21 vols.
8vo, in 1757, with the addition of the reign of George II. down to
that date. The translation and continuation of Rapin were very
successful speculations ; and the publishers, tho Messrs. Knapton, of
Ludgate Street, evinced their gratitude by making Tindal a present of
200^. It is generally stated that he was assisted in both undertakings
by Mr. Philip Morant, to whom solely is attributed the Abridgment or
Summary of the History and Continuation given at the end of the
Bloa. DIV. VOL. VI. 1
latter, and also printed in 3 vols. 8vo, in 1747; but it does not appear
upon what authority it is asserted by Coxe, in the Preface to hia
'Memoirs of Sir Robert Walpole,' that the Continuation, though
published under the name of Tindal, " was principally written by
Dr. Birch." There is no hint of this in the very full and elaborate
Life of Birch, in the second edition of the ' Biographia Britannica, '
which is stated to be compiled from his own papers and the communi-
cations of surviving relations and friends. " His papers," Coxe pro-
ceeds, "in the Museum and in the Hardwicke Collection, which I
have examined with scrupulous attention, and various other documents
which were submitted to his inspection, and to which I have had
access, prove great accuracy of research, judgment in selection, and
fidelity in narration. He derived considerable assistance from persons
of political eminence, particularly the late Lord Walpole, the late earl
of Hardwicko, and the Honourable Charles Yorke. The account of
the Partition Treaty was written by the late earl of Hardwicke. The
account of Lord Somers's argument in Barker's case was written by hia
great-nephew the late Mr. C. Yorke. I can also trace numerous com-
munications by Horace Walpole, though they cannot be so easily
specified. Birch was a stanch Whig, but his political opinions have
never led him to forget his duty as an historian. He has not garbled
or falsified debates, or mis-stated facts ; he has not wantonly traduced
characters, or acrimoniously reviled individuals because they espoused
the cause which he disapproved; but in his whole work, whether he
praises or blames, there is a manly integrity and candid temperance,
which must recommend him to the discerning leader." This is a
sufiiciently just character of the Continuation of Rapin : but, although
in some parts the work has a claim to be considered as an original
authority, it is in the greater part not only a compilation, but a mere
transcription from preceding writers. The authors indeed frankly
state in their prefatory notice that they have not scrupled to copy
or imitate any part of the several authors they have made use of,
when conducive to the usefulness of the work, or where there was no
occasion to alter or abridge. The numerous documents inserted at
full length make the Continuation a convenient repertory of authentic
information ; and the notes which accompany the translation of the
preceding part of the work add greatly to the value of the original
text. Tindal's other publications were — the pamphlet relating to hia
uncle's will, an abridgment of Spence's ' Polymetis,' under the title of
'A Guide to Classical Learning for Schools,' and a translation, from
the Latin, of Prince Cantemir's History of the Growth and Decay of
the Othman Empire, which appeared in a folio volume in 1734.
TINTORETTO, JA'COPO, one of the most celebrated painters of
modern times, and one of the heads of the Venetian school, was the
son of a dyer (Tiiitore), >» hence the agnomen of Tintoretto : his family
name was Robusti ; and he was born at Venice in 1512. He exhibited a
reinarkable facility for drawing at a very early age, which iuduced his
parents to place him in the school of Titian. Ten days however after
young Tintoretto had entered the school of the great painter, he was
sent home again to his parents ; Titian's attention being attracted by
some very spirited drawings he saw in his studio, he inquired who did
them, and upon Tintoretto's acknowledging himself the author,
Titian ordered one of his scholars to conduct the boy home.
This remarkable rebuff in the career of the young painter seems to
have added vigour to his energies, and he commenced a course of
indefatigable application. He purchased some casts from the antique
and some from the models of Daniel da Volterra, from the statues of
Michel Angelo of Morning, Twilight, Night, and Day, at the tomb of
the Medici, in San Lorenzo at Florence, resolving to follow the style
of Michel Angelo in design, and to combine with it the colouring of
Titian, — which intention he proclaimed to his visitors by the following
line, which he wrote upon the wall of his apartment : —
" II disegno di Michel Angelo, e '1 colorito di Tiziano."
By day he copied pictures by Titian ; and by night he made draw-
ings upon coloured paper, with chalk, from his casts, lighted merely
by a candle ; by which means he acquired a taste for strong con-
trasts of light and shade, a peculiarity for which all his works are
conspicuous. To these studies he added the occasional study of the
living model and of anatomy ; and to attain a still greater mastery of
chiar'oscuro, he used to make models of figures in wax, and place them
in pasteboard cases, making apertures for the light as he required it :
he also suspended models and casts from the ceiling, for tho purpose
of becoming familiar with various perspective views of the figure. In
addition to these studies, he is said to have received much gratuitous
assistance fi'om Schiavone in colouring. Tintoretto's first picture
which attracted notice was one containing poi traits of himself and his
brother, by candle-light, himself holding a cast in his hand, and his
brother playing the guitar. He exhibited this picture in public, and
shortly afterwards he exhibited a large historical piece upon the
Rialto, which gave him a rank amongst the great painters of Venice.
It would be impossible to enumerate all his works here; they
amounted to many hundreds. One of his first great works in fresco
wasafagade in the Arsenal, which he painted in 1546, representing
Balshazzar's Feast and the Writing upon the VVaU. Of his first oil
pictures, the following were most remarkable : — The Tiburtine Sibyl,
for the church of Santa Anna ; the Last Supper, and the Washing of
the Disciples' Feet, for the church of Santa Marcola ; for San Severe,
o
83
TINTORETTO, JACOPO.
TIPPOO SAla
84
a Crucifixion, very large; and in the church of the Triuitii, the
Temptation of Eve and the Death of Abel, besides some others.
Tintoretto was so eager for employment, and so desirous of public
notice and applause, that he undertook every commission which
ofif<-red itself, and rather than be inactive or unoccupied with any
public work, he frequently volunteered his services, or at most
required no futher outlay from his employers than would cover the cost
of the materials. He painted upon such terms the facade in fresco of
ft large house near the Ponte dell' Angelo ; on the lower part of the
house he painted a very spirited represf niation of a cavalry battle,
above which be placed an ornamental cornice in bronze ) over this he
painted a large historical composition containing many figures;
between the windows he introduced various figures of women ; and at
the top a rich frieze : the groat extent and the boldness of these paint-
ings astonished the Venetian painters of that period. Upon very
■imilar terms he executed two of his greatest works, at Santa Maria
deir Orto, where he painted, for 100 ducats, two immense pictures
fifty feet high. In one was the Procession of tho Jews with the
Golden Calf, and Moses upon a rock in the background receiving the
Tables of the Law, which were supported by a group of naked angels ;
the other was a representation of the Last Judgment, containing an
immense number of figures; an extraordinary work, which, in the
opinion of Vasari, would have been perhaps without its rival as a
work of art, if the execution of the parts had been equal to tho con-
ception of the whole.
The following works also are accounted amongst Tintoretto's master-
pieces: — Saint Agnes restoring to life the son of the Praefect, painted
for the chapel of Cardinal Contarino ; the Miracle of St. Mark, called
'IlMiracolo dello Schiavo,' where the saint delivers a Venetian, who
had become a Turkish slave, from a punishment ordered by his master,
by rendering him invulnerable, so that hammers and other instruments
of torture were broken upon his body without hurting him; this
picture, which is generally considered the best of all Tintoretto's
works, was painted in his thirty-seventh year, for the brotherhood of
St. Mark, and when it was finished and put up, the worthy friars
disputed with one another about the price, a dispute which Tinto-
retto settled by ordering the picture to be taken down and sent home,
and telling the brotherhood that they should not have it at any price.
He however, after some entreaty, restored it to its place and received
his own price, and the friars further gratified him by ordering him to
paint three other subjects from the life of the same saint, — the Ex-
humation of the Body of the Saint at Alexandria, through the two
Venetian merchants Buono da Malamocco and Rustioo da Torcello ;
the Transport of the Body to the Ship ; and the Miraculous Preserva-
tion at Sea of a Saracen Sailor through the Saint : the miracle of the
slave is in the Academy of Venice ; it has been engraved by J. Nathan ;
the other three are in the Scuola di San Marco. Pietro di Cortona is
reported to have said, that if he lived in Venice, he would never pass
a holiday without going to see these works ; he admired chiefly the
drawing. The pictures he painted for the Scuola di San Rocco are
equally celebrated : they consist of the famous Crucifixion, which was
engraved by Agostino Caracci, to the greatest satisfaction of Tinto-
retto; the Resurrection of Christ, engraved by E. Sadeler; the
Slaughter of the Innocents and the Miracle of the Loaves and Fishes,
engraved by L. Kilian; and several others of less note. To these
must be added three painted for the Padri Crociferi, an Assumption of
the Virgin, and the Circumcision of the Infant Christ, painted in
competition with Schiavone ; and a Marriage at Cana, now in the
church of Santa Maria della Salute. The Miracolo dello Schiavo, the
Crucifixion at San Rocco, and the Marriage at Cana, are said to be the
only pictures to which Tintoretto put his name. There is an engraving
of the Marriage at Cana, by Volpato, and a spirited etching by E.
Fialetti.
Tintoretto executed many great works for the government of Venice,
both in oil and fresco ; and such was his activity, perseverance, and
success, that ho left little to be done by othera. He was always
occupied, and he worked with such unexampled rapidity that he used
to be called II Furioso, Sebastian del Piombo said that Tintoretto
could do as much in two days as he could do in two years. He
painted for the senate, in the council-hall, the Coronation of Frederick
Barbarossa, by Pope Adrian IV., at Rome ; and in consequence of
Paul Veronese painting a picture in the same hall, Tintoretto procured
permission to paint another, in which he represented Pope Alexander
III. surrounded by cardinals and prelates, excommunicating the same
emperor : the pope was represented throwing the extinguished candle
amongst the populace, and a crowd of people was rushing forward to
endeavour to catch it. He painted also for the senate, in the hall
dello Scrutinio, the celebrated naval victory of the Venetians over the
Turks in 1571. Ho painted many other works in the ducal palace,
historical and allegorical, commemorating the history of Venice, of
which the most famous are the capture of Zara by storm ; and the
great picture of Paradise, upon canvas, 74 feet by 34, containing a
surprising number of figures. This was his last great work ; he com-
menced it in several pieces in the Scuola Vecchia della Misericordia,
and finished it, with the help of his son, in its place on the ceiling of
the great council-hall of the Senate, now the library.
Tintoretto painted at Venice eight friezes for the Duke of Mantua,
recording the duke's feats, to be placed in his castle, and he visited
the duke at Mantua, witli all his family, and was splendidly entertained
by him. He painted also the portrait of Henri III. of France aud
Poland, when that king visited Venice; of which picture Ridolfi
relates a curious history. Tintoretto was engaged with Paul Veroueso
in painting some figures in chiar'oscuro upon the arch of triumph
erected by Palladio at Venice in honour of the landing of Henri III.,
king of France and Poland ; but wishing to take a portrait of the
king as he landed, he prevailed upon Paul Veronese to complete the
arch; and he dressed himself as one of the doge's attendants, and
went in the Buciutoro, the state barge, with the others to receive the
king, whose portrait he drew in small, in crayons, unknown to the
king, whilst he was proceeding in the barge to the landing-place. This
portrait he afterwards enlarged in oils, and procured permission from
the king to retouch it from life. The king expressed himself very
much pleased with the portrait, and accepted it from the painter,
whom he wished to create a cavaliere ; but Tintoretto declined the
honour, upon the plea that to bear a title was inconsistent with his
habits. Henri III. afterwards presented the portrait to the doge
Luigi Mocenigo. Tintoretto painted many portraits, all in a remark-
ably bold style ; he painted several of the series of doges' portraits
along the frieze of the great council-hall.
It has been said above that Tintoretto was a remarkably rapid
painter : he was however as careless about the execution of the parts
as he was bold. There are pictures by him painted in his youth that
are extremely carefully finished, but these are very few : Susanna at
the Bath with the two Elders, is of this class ; several of hia large
pictures are merely dead coloured, and many of them were painted
off without the slightest previous preparation. His rapidly-executed
and low-priced productions were a frequent source of complaint to
his fellow-artists. Upon one occasion, when the brotherhood of San
Rocco requested Paul Veronese, Salviati, Zuccaro, Schiavone, and Tinto-
retto to send them designs for a picture of the Apotheosis of San Rocco,
that they might select the best of them, Tintoretto sent his finished
picture as soon as the others sent in their designs, affirming that he
had no other way of drawing ; and to ensure its being fixed in its
destined place, he made the institution a present of tho work.
Although Tintoretto professed to draw in the style of Michel Angelo,
and to colour like Titian, there are few traces of either quality in the
great majority of his works ; they are however all conspicuous for
his own peculiar style of chiar'oscuro, which is frequently both heavy
and cold. In his larger compositions a principal characteristic is the
number of figures, which are often crowded aud confused, and the
spectator looks in vain for a spot of repose to relieve the mind ; this
is however not the case with such pictures as the Miracolo dello
Schiavo and other earlier productions. Annibal Caracci has well
expressed the inequality of this great painter — that if he was some-
times equal to Titian, he was often inferior to Tintoretto. The Vene-
tians used to say that he had three pencils, one of gold, one of silver,
and the other of iron. lu his design Tintoretto was muscular, but
lean, and often incorrect ; and in the cast of his draperies frequently
mean and confused ; his colouring was not gaudy, like that of many
of the Venetians, but was often even cold, and shadow predominates
in perhaps all his pictures. He was once asked which were the pret-
tiest colours, and he answered " black and white." It was also a
maxim of his that none but experienced artists should draw from the
living model, as they were alone capable of distinguishing between the
beauties and the imperfections of an individual model. Tintoretto
painted Aretin's portrait, and Ridolfi relates the following anecdote
connected with it : — Aretin was a great friend of Titian's and was in
the habit of abusing Tintoretto occasionally : the latter one day
meeting the poet, invited him to come and sit to him for his porti-ait,
to which Aretin assented ; but he had no sooner seated himself in
the painter's studio, than Tintoretto pulled out with great violence a
pistol from underne.ith his vest and came towards him : up jumped
Aretin in a great fright, aud cried out " Jacopo, what are you about ?"
" Oh ! don't alarm yourself," said Tintoretto, " I am only going to
measure you ; " and suiting the action to the word, he said, "you are
just two pistols and a half." " What a mountebank you are ! "
returned Aretin ; " you are always up to some frolic." The poet was
afterwards more cautious, aud they became friends. Ridolfi records a
few other whimsical feats of Tintoretto's. He died at Venice in 1594,
aged eighty-two. He had two children — a son, Domenico, and a
daughter, Marietta — who both practised painting. Domenico was born
in 1562, and died in 1637. He followed in the steps of his father
both in history and portrait ; but, says Lanzi, as Ascanius did those
of .tineas, non passibus sequis. Marietta was born in 1560, and died
before her father, in 1590. She painted very excellent portraits. The
only picture by Tintoretto in the National Gallery is one of no great
merit, ' St. George destroying the Dragon.'
(Ridolfi, Le Maraviglie dell' Arte, ovvero l« Vite degli Illuatri Pittori
Veneli, e dello Stato ; Zauetti, Delia PiUura Veneziana, e delle Opere
puhbliche de' Veneziaiii Maestri, t&c.)
TIPPOO SAIB, sultan of Mysore, was born in the year 1749. His
father Hyder Aly Khan [Hyder Aly], sensible of the disadvantages
under which he hims^elf laboured from want of education, procured
for his son the best masters in all the sciences which are cultivated
by the Mohammedans. But Tippoo, although he had acquired a
taste for reading, did not make any considerable progress, and he
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TIPPOO SAIB.
TIPPOO SAIB.
88
preferred martial exercises, into which he was initiated at an early age.
The French officers in the employment of his father instructed him
in tactics; and iu 1767, when Hyder Aly overran the Carnatic, Tippoo
was entrusted with the command of a corps of cavalry. He was at
that time nineteen years of ago ; but the success with which he carried
on tlie war in the neighbourhood of Madras sufficiently proved how
much he had profited by his European teachers. During the war
with the Mahrattas, which lasted from 1775 to 1779, Tippoo acquired
the universal esteem of the army ; and he rose bo high in the favour
of his father and hia counsellors, that the left division of the Mysore
army, consisting of 18,000 cavalry and 6000 regular infantry, was put
under his command. With this force Tippoo attacked Colonel Bailey
in the neighbourhood of Perimbakum, on the 6th of September 1780.
He was obliged to retire; but on the 10th of the same month an
engagement, in which Tippoo Saib is said to have taken an active part,
ended iu the entire defeat of the English army. The whole of the
war in the Carnatic gave him opportunities of perfecting himself in
the art of war ; and on the 18th of February 1782, he showed his
skill in the attack and complete defeat of Colonel Braithwaite, on the
banks of the Kolerun. This was undoubtedly his greatest stroke of
generalship, yet the disproportion of force was very great. Tippoo
had 400 Europeans, 10,000 native infantry, and 10,000 cavalry, besides
20guDs; while the entire force under Colonel Braithwaite consisted
of 100 European soldiers, 1,500 sepoys, and 300 native cavalry. A
few months afterwards Tippoo was obliged to move towards the south,
in order to meet the English troops in the provinces of Tanjore and
Malwa, under the command of Colonel Humbertson. On the 20th of
November Tippoo found the English at Paniany. He made a vigorous
attack, but was repulsed and compelled to retreat. He crossed the
river Paniany, and prepared himselt for another engagement, when on
the 11th of December 1782, he received intelligence of the death of
his father. On the 20th he was at Seringapatam, where he mounted
the niusnud without much display or ceremony. He had scarcely per-
formed the funeral rites of his father when he returned to Arcot, and
assumed the command of his army. But whilst he was engaged in
the Carnatic General Matthews took Onore, and the country of Bed-
nore was in the hands of the English. In order to regain these more
valuable possessions, Tippoo was obliged to relinquish his conquest in
the Carnatic, and by the end of March 1783, scarce a Mysorean was
left in that country. His operations were so rapid and successful,
that on the 28th of April Tippoo Saib had already reduced the garri-
son of Bednore to the necessity of capitulating. General Matthews
and several of the principal ofBcers were barbarously put to death.
After the reduction of this city, it was Tippoo's object to repossess
himself of Mangalore, the principal seaport in his dominions. But
the place was well -defended; and in the midst of his preparations for
the assault accounts were received in the camp of peace having been
concluded between England and France, It was early iu July 1783
when M. de Bussy, in consequence of this news, declined to act any
longer against the English. He -quitted the camp with his detach-
ment. A considerable reinforcement having arrived under General
Macleod, Tippoo agreed to a suspension of arms; and early in the
year 1784 Sir George Staunton and two other ambassadors from
Madras arrived in the camp, and on the 11th of March a treaty of
peace, which stipulated for the liberation of all the prisoners and the
restitution of all places taken by either party during the war, was
concluded. About the end of the same year Tippoo concluded a
treaty of peace with the court of Poonah. He then returned to Serin-
gapatam, and assumed the title of Sultan, thereby throwing off all
dependence on or allegiance to the captive Eajah (imprisoned by his
father) or the Great Mogul.
In 1786 he occupied himself with internal regulations; and from
an inventory made at this period we find that the treasure, jewels, and
other valuable articles were estimated at eighty millions sterling. He
had also 700 elephants, 6000 camels, 11,000 horses, 400,000 bullocks
and cows, 100,000 buffaloes, 600,000 sheep, 300,000 firelocks, 300,000
matchlocks, 200,000 swords, and 2000 pieces of cannon, and an
immense quantity of gunpowder and other military stores. His
regular army consisted of 19,000 cavalry, 10,000 artillery, and
70,000 infantry. He had also 6000 rocket-men, and 40,000 irregular
infantry.
During the years 1787 and 1788 the attention of the sultan was
principally engaged in the conversion and subjection of the Nairs, or
chiefs of Malabar. He is said to have carried away from that province
70,000 Christians, and to have made Mussulmans of 100,000 Hindus.
This he effected by forcible circumcision, and compelling them to
eat beef.
of all the Hindoo temples iu his dominions, exceptin^those of Seringa-
patam and Mail Cottah. Fortunately his officers did not enforce this
barbarous regulation.
Although Tippoo Saib did not show any overt hostility toward the
English after he had signed the treaty of 1784, yet in 1787 he sent an
embassy to France, to enter into an offensive and defensive alliance,
and to stimulate the court of Versailles to a speedy renewal of hostili-
ties with England. The ambassadors returned to Seringapatam in the
month of May 1789, without having obtained their object. The dis-
appointed sultan vented his rage by putting two of them to death as
having betrayed his interests. Tippoo hated the British power in
India, and he took every opportunity to annoy such of the native
kings as were under its protection. The Rajah of Travancore had by
the treaty of Mangalore stipulated for the security of his territories.
In April 1790 Tippoo invaded the country and subjected the whole of
the northern district. The reasons assigned by Tippoo for the infrac-
tion of the terms of the treaty were, that two forts, Cranganagore and
Jyacotta, which were on the northern boundaries of the raja's pos-
session, had belonged to his father. This aggression was considered
by the English equivalent to a declaration of war, and Colonel Hartley
was sent with a considerable detachment to the assistance of the raja.
At this intelligence Tippoo withdrew his army from Travancore, and
returned to Seringapatam, when, to his dismay, he heard that the
Mahrattas and the Nizam had promised the English a zealous co-opera-
tion with their forces.
On the 15th of June 1790 the English troops, under the command
of General Meadows, entered the sultan's territory, and took possession
of the fort of Carur without resistance. Daraporam and Coimbatore
were shortly afterwards reduced. About the same time a detachment,
under Colonel Stuart, captured Dindigul and Paligautchery. The
movements and operations of the English forces were so wdl con-
ducted that Tippoo found himself unable to oppose them, and he
of defending his own territories, to lay waste those of his enemy.
This he did with considerable ability ; for in the beginning of 1791
the English, instead of being masters of great part of Mysore, as they
had expected, found themselves attacked and annoyed in the very
On the 29th of January 1791, Lord Cornwallis assumed the command
of the army, and on the 11th of the same month he was at Vellore.
On the 21st of March the fort of Bangalore was taken by storm. On
this event Tippoo retired to some distance, and wrote to Lord Corn-
wallis, requesting a truce. This was refused, and he proceeded to
Seriugapatam, leaving his army under the command of one of his gene-
rals, to watch the motions of the English. On the 3rd of May Lord
Cornwallis was at Arakery, within sight of the sultan's capital ; but
his troops had suffered a great deal frocft want of food and forage, and
he was compelled to retreat towards Bangalore. The Mahrattas came
however to his assistance, and the warfare was carried on with great
success.
However, whilst the English were carrying on their successful
operations in the north-west part of Mysore, the sultan made a diver-
sion towards Coimbatore, situated to the south of Seringapatam ; and
Lieutenant Chalmers with the whole of his party were made prisoners.
The skill of Tippoo Sultan enabled him to protract the war till the
month of Februai-y 1792, when the allies (the English, the Mahrattas,
and the troops of the Nizam) encamped in sight of the capital. But
it was not until General Abercromby bad united his forces to those of
Lord Cornwallis, and had determined to take the town by storm, that
the haughty mind of the sultan was humbled. He agreed to give the
allies one-half of his dominions, and to pay them in the course of
twelve months the sum of three krores and thirty lacs of rupees
(3,030,000Z.), to restore all the prisoners, and to deliver up as hostages
two of his eons. Abdul-khalik and Moaz Addeen were the names of
the two princes, and the attention and kindness evinced by Lord
Cornwallis towards them, were such as to afford the highest gratifica-
tion to the sultan their father. By signing the definitive treaty of the
16th of March 1792, the sultan lost one-half of his dominions. Soon
after this the allies quitted the neighbourhood of Seringapatam, and
Tippoo sought the means of replenishing his treasury. This was soon
done by imposing exorbitant and extraordinary taxes, which were
chiefly levied upon the agriculturists.
Notwithstanding this seeming tranquillity from 1792 to 1796, the
sultan was engaged in inciting all the native chiefs against the British
power in India; but it was not until 1798 that the whole extent of
his secret machinations and intrigues became known. At the com-
mencement of this year ambassadors were sent from Seringapatam to
the Mauritius. Their object was to renew the sultan's relations with
France, and to solicit the aid of 10,000 European and 30,000 negro
troops. The proceedings of the embassy were first made known in
the month of June to the Marquis Wellesley, the goveruorgeneraL
About the same time intelligence was received in India of the opera-
tions of the French in Egypt. Circumstances like these left no doubt
as to the intentions of the sultan, and on the 3rd of Febraary 1799,
orders were issued for the British armies and those of the allies imme-
diately to invade the dominions of Tippoo. Hostilities commenced on
the 5th of March; and on the 5th of April General Harris took a
strong position opposite the west side of Seringapatam. After be-
sieging the place some time, a general attack was made on the 4th of
May 1799. The sultan had scarcely finished his repast when he heard
the noise of the assault. He instantly repaired towards a breach which
the English had succeeded in making a few days before. His troops
fled ; he endeavoured to rally them ; and so long as any of his men
remained firm, he continued to dispute the ground against an English
column which had forced the breach and gained the ramparts. Finding
all his efforts against the enemy fruitless, he mounted his horse, and,
in endeavouring to effect his retreat, arrived at a bridge leading to the
inner fort ; but the place was already occupied by the English, and in
87
TIRABOSCHI, GIROLAMO.
TIRABOSCHI, GIROLAMO.
his attempts to proceed he was met by a party of Europeans from
witbinside the gate, by whom he was attacked. Owing to two wounds
which he received iu his breast he fell from his horse ; his attendants
placed him upon a palankeen in one of the recesses of the gateway,
and entreated him to make himself known to the English. Tliis he
disdainfully refused to do. A short time afterwards some European
aoldiera entered the gateway, and one of them attempting to take off
the sultan's sword-belt, the wounded prince, who still held his sword,
made a thrust at him and wounded him in the knee; upon which the
soldier levelled his musket aud shot him through the head. On the
afternoon of the 5th of May he was buried in the mausoleum of Hyder
Aly. Fuur companies of European troops escorted the funeral pro-
ces'iion, which was strikingly solemn.
When Tippoo met his death he was in his fiftieth year. Although
after his misfortunes in 1792 he oppressed tlie people more than they
had ever been in the time of his father, he was nevertheless popular ;
and tlie Mysoreans considered hiui as a martyr to the faith, and as a
prince who fell gloriously in the cause of his religion. He used to
pass a great portion of his day in x-eading, and his library, consisting
collection is preserved at the East India House, London ; the other
half was left at Fort William for the use of the college. The museum
and library of the East India House contain many articles both of
value and curiosity which once belonged to Tippoo Saib.
(' Memoirs of Ti(>poo Sultan,' in Stewart's Deicriptive Catalogue of the
Oriental Library of the late Tippoo Sultan of Mysore, Cambridge, 1809.)
TIliA-BOSCHI, GIRO'LAMO, was born at Bergamo in 1731. He
studied in the college of Mouza, and afterwards entered the order of
the Jesuits. About 1766 he was made professor of rhetoric in the
University of Milan, where he wrote Lis first work, the history of a
moonstic order long siuce suppressed, under peculiar circumstances :
'Vetera Huujiliatorum Monumenta,' Milan 1766. In 1770 he was
appointed by tiie Duke of Modena librarian of his rich library, in the
place of Father Granelli, deceased. He now applied himself to the
und<-rtaking of his great work, ' Storia della Letteratura Italiana,'
published at Modena 1772-1783, which he completed in eleven years.
The subject was -vast and intricate ; the only author who had yet
attempted to writs a general history of Italian literature, Gimma of
Naples, had only sketched a rough and very defective outline of it in
his 'Storia dell' Italia Letterata.' There were however local histories
and biographies concerning particular towns and districts, and the rest
of the materials had to be souglit among the archives and libraries of
Italy. Tiraboschi undertook to write the history of the literature of
ancient and modern Italy in the most extended sense of the word,
including most of, if not all, the individuals deserving of mention in
every department of learning, who have flourished in Italy, from the
oldest times on record, beginning from the Etruscans and the Greek
colonies of Magna Grrecia and Sicily, and then proceeding with the
history of Roman literature through its rise, progress, and decay,
down to the invasion of the northern tribes, with which the second
volume concludes. Theauthor distributes the great divisions of learning
in separate chapters; poetry, grammar, oratory, history, philosophy,
medicine, jurisprudence, and the arts; he gives an account of the
principal libraries, aud of the great patrons of learning, and although
he does not profess to write biography, properly speaking, yet he gives
bio>;raphical notic.-s of the more illustrious writers and of their pro-
ductions. The third volume comprises the literary history of Italy
during the dark ages, as they are commonly called, from the 5th to the
12th cvntury. The author makes his way through the scanty and
obscure records of those times, and brings to light much curious
information concerning the intellectual state of Italy under the Goths,
the Longobards, and the Franks. The ecclesiastical writers come in
for a gr- at share of this part of the work. The fourth volume includes
the period from 1183 to the year 1300. The revival of studies, the
formation of the Italian language, the foundation of universities,
notices of the civilians and canonists who flourished in that age, an
account of tiie Italian troubadours, of the earliest Italian poets, and
of the Italian Latinists, and a view of the splendid architectural
works of Arnolfo di Lapo, of Niccol5 and Giovanni of Pisa, and other
artists, impart a cheering aspect to this period. The fifth volume
embraces the 14th century, the age of Dante, Petrarca, and Boccaccio.
The author is particularly difl'use in speaking of Petrarca. The
sixth volume concerns the 15th century, an age of classical studies,
the age of Cosmo and Lorenzo de' Medici, of Poggio, Filelfo, Niccoli,
Palla Strozzi, Coluccio, Salutati, Paolo Manetti, Cardinal Bessarion,
and other collectors of manuscripts, founders of libraries, and encou-
ragers of learning, and the age also of distinguished jurists and eccle-
siastical writers. This volume is very large, and is divided into three
parts, whilst the preceding volumes are divided each into two parts,
each part being subdivided into books and chapters. We cannot help
thinking that this mode of division is too formal and cumbersome,
and that it might have been simplified and made clearer.
The seventh volume of Tiraboschi's history treats of the 16th
century, the age of Leo X., the Augustan age, as it is sometimes called,
of Italian literature. This volume, which is still more bulky than
the one preceding, U divided into four parts. After giving a sketch of
the general condition of Italy during that period, of the encourage-
ment to learning affurdod by the various princes, of the universities,
academies, libraries, and museums, the author treats first of the
theological polemics which arose with the Reformation, then of the
philosophical and mathematical studies, of natural history and medi-
cine, of civil and ecclesiastical jurisprudence, of historical writing, and
of the Italian Hellenists and Orientaliste. He passes next in review
the Italian poete, among whom Ariosto and Tasso hold a conspicuous
place, and afterwards the Latin poete, the grammarians, rhetoricians,
and pulpit orators, and lastly tho artists, among whom Michel Angelo,
Raffaelle, Tiziano, and Correggio stend prominent. It is impossible to
peruse this long list of illustrious names without being struck with the
seemingly inexhaustible fertility of the Italian mind in almost every
branch of knowledge.
The eighth volume embraces the 17th century, which in Italy is
scornfully styled the age of the " seicentisti,' or the age of bad taste, a
reproach however which applies mainly to tho poets, and not even to
the whole of them. The department of history is filled with good
names, as well as that of the mathematical sciences, in which Galileo
holds the first rank. With the 17th century Tiraboschi concludes his
work. Various reasons prevented his entering the field of contem-
porary history. This however has been done of late years by Lombardi,
in his continuation of Tiraboschi's work: 'Storia della Letteratura
Italiana nel Secolo xviii.'
Tiraboschi's work was highly esteemed, and went through numerous
editions in various parts of Italy. The author himself superintended
the second edition of 'Modena,' 1787-94, in which he made corrections
and additions, chiefly iu the shape of notes to the text. Antonio
Landi made an abridgment of the work in French, which was pub-
lished at Paris, and at Bern, in 1784; and J. Retzer made a similar
abridgment of it iu the German language. When the work of Tira-
boschi appeared, no other country iu Europe had a general history of
its own literature. The learned Benedictines of St. Maur had bt-gun a
work of this kind concerning the literature of France, which however
they left imp'-rfect. The work of Tiraboschi does not give all the
information that one might wish, but contains probably as much
information as could be collected and compressed together by any one
man upon the subject. It has been said to be deficient in criticism, and in
the analysis of conspicuous works, of which he has not given extracte ;
but this, as he says in his preface, did not form part of his plan, which
was already extensive enough, or the work would have had no end.
His accuracy and conscientiousness are undisputed. The tone of his
remarks, especially on religious matters, is perhaps as temperate as
could be expected from a man of his profession, times, and country,
who was a sincere believer in the tenets of his church, though not a
bigot. For a proof of this we might refer the reader to Tiraboschi's
letter to Father Mamachi, a Dominican, who edited at Rome an
edition of Tiraboschi's great work with corrections and notes to those
passages which were not consonant with his own high notions of Papal
prerogative and Roman supremacy, both spiritual and temporal. Tira-
boschi's letter was published at Modena in 1785, and was afterwards
inserted at the end of the last volume of the second Modena edition of
the ' History of Italian Literature.' A tone of refined cutting irony,
half veiled, under a most courteous style of language, pervades the
whole of the letter. The French writer Ginguen^ has followed closely
Tiraboschi's footsteps in his ' Histoire Litt^raire d'ltalie,' which how-
ever contains only the modem part, or the history of the literature of
the Italian language. [Ginguene.]
The Duke of Modena, Ercole III. of Este, in consideration of Tira-
boschi's useful labours, made him a knight, and appointed him member
of his council in 1780. By the suppression of the order of Jesuits,
Tiraboschi had become a secular priest. In 1781 he began to publish
another work of bibliography and biography : * Biblioteca Modenese, o
Notizia della Vita e delle Opere degli Scrittori natii degli Stati del
Serenissimo Duca di Modena,' 6 vols. 4to, Modena, 1781-86; to which
he afterwards added a seventh volume, containing notices of the artists
who were born in the dominions of the house of Este. Having thus
illustrated the literary history of Modena, and of the other territories
of the house of Este, he afterwards wrote the political history of the
same country, in his ' Memorie Storiche Modenesi, col codico diplo-
matico, illustrato con note,' 3 vols. 4to, Modena, 1793. He also
published the history of the ancient monastery and abbey of Nonan-
tola in the duchy of Modena, founded about the middle of the 8th
century by Anselmus, Duke of Friuli, and afterwards greatly enriched
by Charlemagne and other princes, and which became a powerful com-
munity during the Middle Ages ; ' Steria dell' augusta Badia di S.
Silvestro di Nonantola, aggiuntovi il codice diplomatico della mede-
sima, illustrato con note,' 2 vols, folio, Modena, 1784. The other
works of Tiraboschi are : 1, ' Vita del Conte D. Fulvio Testi.' Testi
was a lyric poet of tlie 17th century, and enjoyed for a time a high
ofi&ce at the court of Modena, but ended his days in prison for state
reasons ; 2, ' Lettere intorno ai viaggi del Sigr. Bruce,' inserted in the
'Notizie Letterarie' of Cesena, 1792; 3, 'Memoria delle cognizioni
che si avevano delle sorgenti del Nilo prima del Viaggio del Sigr.
Jacopo Bruce,' inserted in the 1st vol. of the ' Memorie dell' Acca-
demia delle Scienze di Mantova ; ' 4, Two memoirs on Galileo, his
discoveries, and his condemnation by the Inquisition, inserted in the
last vol. of the second Modena edition of the ' History of Italian
Literature;' 5, 'Notizie della Confrateruith, di S Pietro Martire;'
6, ' Vita di Sant' Olimpia, Vedova e Diaconessa della Chiesa di Costan-
89
TIRIDATES.
TISCHBEIN, JOHN HENRY,
90
tinopoli;' 7, 'Elogio Storico di Ratnbaldo de Conti Azzoni Avo-
garo;' besides other minor writiugs, especially in answer to the
critics of his ' History of Italian Literature ' He left unpublished : 1,
'Dizionario Topografico degli Stati Estensi,' published since atModena,
1824-5 ; 2, ' Catalogo ragionato dei Libri del gib, Collegio dei Gesuiti
di Brera;' 3, ' Lettera suUa Venuta di Gustavo Adolfo in Italia;'
4, ' Vita di Giannandrea Barotti Ferrarese ; ' 5, 'Notizie suUa Zecca di
Brescello, tsopra alcuni Luoghi del Modenese, ed Albero della casa
Montecuccoli;' besides several dissertations and orations. His volu-
minous correspondence is preserved in the Modena Library.
Tiraboschi died at Modena, in June 1794, of a disease brought on by
sedentary life and constant application. He was buried in the church
of SS. Faustino e Qiovita, outside of the city, and a Latin inscription
was placed on his tomb, written by Father Pozzetti, who succeeded
him as librarian, commemorative of his labours and his virtues, among
which modesty and charity were most conspicuous.
(Elof/io di Girolamo Tirahoschi, by Pozzetti, prefixed to the later
editions of the 'Histoire of Italian Literature;' Ugoni, Storia delta
Lettcratura Italiana nella seconda meta del Secolo X VIII. ; Lombardi,
Storia della Letteratura Italiana net Secolo XVIII.)
TIRIDA'TKS, prince of Media, and afterwards king of Armenia,
was the brother of Vologeses, king of the Parthians, that is, of Media.
Ho first appears in history in a.d. 53, in the first war of Corbulo
against Vologeses (Tacitus, ' Hist.,' xii. 50), who was compelled to
desist from his schemes upon Armenia in 54. In 58 however the
Parthians ajjain overran Armenia, having been invited by the inhabit-
ants of that country, and Vologeses ceded his conquest to his brother
Tiridates, who thus became king of Armenia. As the Romans would
not allow this country to become a possession of the Parthians, Cor-
bulo directed his forces against the royal brothers, knowing that
Vologeses was prevented from employing his army against him in
consequence of an insurrection of tlie province of Hyrcania. Corbulo
therefore soon persuaded Tiridates to submit to the emperor Nero,
and to prefer a moderate dependence to an imcertain and dangerous
independence. ■ When they were about to meet, in order to settle the
conditions of the peace, Tiridates suddenly became afraid of some
treacherous design on the part of the Romans, and he therefore
broke off the negociations and renewed the war. Corbulo however
defeated him at Artaxata on the Araxes, took and destroyed this old
capital of Armenia, and forced the new capital, Tigranocerta, to sur-
render after a short siege. (Tacitus, ' Hist.,' xiv. 24 ; Frontinus,
* Stratag.,' ii, 9, exempl. 6.)
Tiridates fled to his brother, who had taken the field against the
Hyrcanians, and who entrusted him with the command of a new army,
with which Tiridates hoped to expel the Romans from Armenia. He
attacked them on the side of Mesopotamia, but the strong position
which the Romans kept at Tigranocerta, aud the care which they
showed in watching the passages of the Euphrates, prevented him
from either penetrating into the valley of the Upper Tigris, or from
invading Syria, a mauoDuvre by which Corbulo would have been
obliged to hasten to the relief of this province, and to leave Armenia
to the incursions of Vologeses. Tiridates therefore listened once
more to the pacific proposals of the Romans, who were anxious to
avoid any war with the Parthians if they could do so on conditions
which would secure their influence over Armenia. Their intention
was not to make a Roman province of Armenia. Ambassadors from
Tiridates arrived in the camp of Corbulo, and they declared, in the
name of Tiridates and his brother Vologeses, that Tiridates was ready
to submit to Nero, as a vassal-king, and that Vologeses would keep in
future a better understanding with the Romans than before. In order
to settle the peace, a day was fixed on which Tiridates was to appear
in the camp of Corbulo, who sent Tiberius Alexander [Tiberids
Alexander] and his son-in law Vivianus Annius as hostages into the
canjp of Tiridates (a.d. 63). When Tiridates entered the tent of
Corbulo, he took off his royal diadem, and placed it at the foot of a
portrait of the emperor Nero, taking an oath that he would not exer-
cise any right of sovereignty in Armenia till he had again received the
same diadem from the hands of the emperor in Rome. (Tacitus,
' Hist.,' XV. 28, 29.) Tiridates arrived in Rome in 66, and when he
approached the city a great number of people came out from the
gates to behold the entrance of an oriental king descended from the
mighty sovereigns of the Parthians. In Zumpt, 'Annales veterum
Regnorum et Populorum, imprimis Romanorum,' the Armenian king
who entered Rome in 66 is called Tigranes, but this is a typographical
error. (Tacitus, * Hist.,' xvi. 23.) The latter circumstances of the
life of Tiridates are unknown.
TISCHBEIN, JOHN HENRY, called the Elder, one of the most
celebrated painters of the 18th century, was the fifth son of a baker
of Hayna, near Gotha, where he was born in 1722. He was first
apprenticed to an uncle on the mother's side, who was a locksmith ;
but he displayed so much talent in drawing, that an elder brother,
John Valentine, took him away from his uncle and placed him, in his
fourteenth year, with a paper-stainer and decorator in Cassel of the
name of Zimmermann. He received also some instniction from Van
Freese, the court painter at Cassel, and soon gave proof of his ability.
Tischbein met with an early and a valuable patron in Count Stadion,
through whose assistance he was enabled, in 1743, to visit Paris,
where he remained five years with Charles Vanloo, and acquired, his
style of painting. From Paris he went to Venice, and there studied
eight months with Piazzetta. From Venice he went to Rome, where
he remained two years. He again visited Piazzetta in Venice, and
after a short time, in 1751, he returned to Cassel, where, in 1752, he
was appointed cabinet painter to the landgrave.
Tischbein excelled in historical and mythological subjects, in which
lines are his best pictures, painted from about 1762 until 1785. He
died in 1789, as director of the Academy of Caasel, and a member of
the Academy of Bologna. A biographical notice of Tischbein, with
criticisms upon his works, was published in Niirnberg in 1797, eight
years after his death, by J. F. Engelschall, entitled ' J. H. Tischbein,
als Mensch und Kunstler dargestellt.' In that work there is a list of
144 historical pieces by Tischbein, of which the following have been
considered the best : — the Resurrection of Christ, very large figures,
painted in 1763, for the altar of St. Michael's church at Hamburg;
the Transfiguration, in the Lutheran church at Cassel, 1765; Her-
mann's Trophies after his Victory over Varus in the year 9, in the
palace of Pyrmont, 1768 ; ten pictures of the life of Cleopatra, painted
in the palace of Weissenstein, 1769-70 ; sixteen from the Life of
Telemachus, in the palace of Wilhelmsthal ; an Ecce Homo, in the
Roman Catholic chapel at Cassel, 1778 ; a Deposition from the Cross,
and an Ascension, altar-pieces in the principal church of Stralsund,
1787; Christ on the Mount of Olives, an altar piece presented by
him to the church of his native place, Hayna, 1788 ; the Death of
Alcestis, 1780; and the Restoration of Alcestis to her Husband by
Hercules, 1777.
Tischbein painted many pictures from the ancient poets, and some
from Tasso, several of which are now in the Picture-Gallery at Cassel.
He painted also a collection of female portraits, selected chiefly for
their beauty, which is now at the palace of Wilhelmsthal near Cassel.
He also frequently copied his own pictures. Nearly all his works
remain in his own country, on which account he is little known out of
it. It is remarkable that of all the great galleries of Germany, Miinich
is the only one that possesses a specimen of his works, and that is only
a portrait.
Tischbein painted very slowly, but he was very industrious : he was
generally at his easel by five in the morning in the summer time, and
he painted until four in the afternoon. He painted in the French
style ; his colouring was a mixture of the French and the Venetian,
and in large compositions very gaudy, but his drawing and chiar'-
oscuro were very good ; in costume however he was incorrect, and,
according to the critics, he generally contrived in his ancient pieces to
make his actors look much more like Frenchmen and Germans than
Greeks or Romans. In his religious pieces he was more successful :
he was no follower of Lessing's theory of beauty ; he considered
beauty of little consequence. He etched several plates after his own
pictures : — Venus aud Cupid, Women Bathing, Hercules and
Omphale, Menelaus and Paris, Thetis aud Achilles, and his great
picture of the Resurrection of Christ, at Hamburg.
Tischbein's elder daughter Amalia was a clever painter : she was
elected, in 1780, a member of the Academy of Cassel; she used to
sit to her father for many of the females in his historical works. After
Tischbein's death, the Landgrave of Cassel purchased all the works
that were in his house, and placed them together in the palace of
Wilhelmshohe.
(Meusel, Miscellaneen Artistischen Inhalts; FvlsbH, AUgemeines Kilntt-
LG7* JjCOCICOTI ' oSC ^
TISCHBEIN,' JOHN HENRY WILLIAM, called the Younger, the
youngest son of John Conrad Tischbein, and nephew of the preceding,
with whom he is sometimes confounded, was born at Hayna in 1751.
He was instructed by his uncle John Henry at Cassel in historical
painting, and he afterwards studied landscape painting three years
with his uncle John Jacob at Hamburg; in 1770 he went to Holland,
where he remained two years, and in 1772 returned to Cassel and
painted portraits and landscapes ; he visited also Hanover and Berlin,
and painted many portraits in both places. In 1779 he left Cassel, by
the desire of the Landgrave, for Italy, but he spent about two years
in Zurich, where he painted many portraits and made the design of
his celebrated picture of 'Conradin of Suabia, playing, after his
sentence to death, a game at draughts with Frederick of Austria,' In
1781 Tischbein arrived in Rome, and his first studies were some
copies in oil after Raffaelle and Guerciuo, and some drawings after
Raffaelle, Domenicbino, and Lionardo da Vinci. His first original
picture was ' Hercules choosing between Vice and Virtue, after which
he painted his picture of Conradin of Suabia, now in the palace of
Pyrmont. In 1787 he went to Naples, and the next year painted the
portrait of the crown-prince for the queen, who presented Tischbein
with a valuable snuff-box and 200 ducats, expressing her complete
satisfaction with the picture. In Naples he appears to have acquired
laurels rapidly, for in 1790 he was appointed director of the Academy
with a salary of 600 ducats per annum, which however he lost again
in 1799, at the breaking out of the revolution at Naples, but he
found no difficulty in obtaining permission from the French authori-
ties to return to Germany with what property he chose to take with
him. He accordingly embarked, with the painter Hackert and another,
for Leghorn, taking with him the plates of his illustrations to Homer,
his designs for Sir W. Hamilton's second collection of vases, and some
other works of art : but the ship was driven by a storm upon the
01
TISSOT, SIMON ANDREW.
TITI, SANTI DI,
coast of Corsica, and was captured by a French ship of war ; it was
however set at liberty again, and after a troublesome journey of four
months Tischbein at last reached Cassel in safety. During his resi-
dence in Naples he published there in 1796, a remarkable work upon
animals, in two parts, folio, entitled ' T6tes des difWrents Aniraaux,
dessinds d'aprfes Nature, pour donner une id<5e plus exacte de leurs
caractcres.' Tiie firHt part contains sixteen designs of animals, and
the first plate of this part is the celebrated design called iu Italy Tisch-
bein's Laocoon ; it represents a large snake attacking and df stroying a
lioness and her young in their den : the second part contains eight
plates only, consisting of characteristic heads of men and gods, as —
Correggio, Salvator Rosa, Michel Angelo, Raffaelle, Soipio Africanus,
lived principally at Hamburg and at Eutin in Oldenburg near Liibeck ;
the majority of his works arc in the possession of the grand-duke of
Oldenburg : the following paintings are three of his most celebrated
works : — Ajax and Cassandra, painted in 1805 ; ' SuflFer the Little
Children to come unto me,' painted in 1806, for the altar of the
church of St. Angari at Bremen ; and Hector taking leave of Andro-
mache, painted in 1810. He painted also the portraits of Klopstock,
of Heyne, and of Blucher.
In Gottingen in 1801-4 he published in royal folio his favourite
Work on Homer, with explanations by Heyne — 'Homer, nach Antiken
gezeichnet von Heinrich Tischbein, Direcktor, &c., mit erliiuterungeu
von Chr. Gottl. Heyne.' i.-vi., each number containing six plates : the
portraits of the Homeric heroes were engraved by R. Morghen. Tisch-
bein's drawings for Sir W. Hamilton's second collection of vases,
publiched at Naples from 1791, in 4 vols, folio, amount to 214 : the
work is entitled ' A Collection of Engravings from Ancient Vases,
mostly of pure Greek workmanship, discovered in Sepulchres in the
Kingdom of the Two Sicilies, but principally in the environs of
Naples, during the years 1789 and 1790; now in the possession of
Royal Academy of Painting at Naples.' The text, which is iu French
and I'^nglish, is by Italinsky. Tischbein published other works, and
etched also several plates, after Paul Potter, Roos, Rosa di Tivoli,
Rembrandt, &c. As a painter his drawing was correct, and his
expression and colouring good, and he excelled in drawing animals.
He died in 1829. There were many other artists of this family, of
various degrees of merit, but they are imknown beyond their own
circles.
TISSOT, SIMON ANDREW, au eminent Swiss physician, was born
at Lausanne, in the canton de Vaud, in 1728. He studied first at
Geneva, and then at Montpellier, fi-om 1746 to 1749, where he took
his deijree of Doctor of Medicine. He then returned to Switzerland
and settled at Lausanne, where he joined to an extensive practice a
considerable degree of theoretical knowledge. His reputation spread
rapidly through Europe in consequence of his medical publications,
and caused him to be consulted from all parts. He was also offered
at various times several important situations at different foreign
courts and universities, all of which he declined, and remained satis-
fied with the respect and comfort which he enjoyed at home, and
with the ofiice of professor of medicine at the college of Lausanne.
However in 1780, he could not resist the warm solicitations of the
Emperor Joseph II., who conferred on him the professorship of clinical
medicine at the university of Pavia. Being thrown thus late in life
into so difficult a post, and being naturally of a modest and shy dis-
position, he did not at first answer the expectations formed of him.
However there soon after broke out in the province an epidemic bilious
fever, as to the treatment of which the physicians of the place were
not agreed. On this occasion the Count de Firmian, the celebrated
minister under the archduke, gave orders that Tissot's directions
should be followed, as he bad treated a similar disorder with great
success in the canton of Le Valais in 1755, His system was again
successful, and the students not only celebrated his triumph with fStes,
but, wishing to render the memory of it more durable, they caused a
marble inscription, beginning with the words ' Immortali Prseceptori,'
to be placed under the portico of the school. After holding his pro-
fessorship for three years, Tissot obtained permission to retire from
office. During his stay in Italy he had made use of the vacations to
travel through the finest parts of that country, and was everywhere
received with the most marked and flattering attention. Pope
Pius VI. signified his desire of seeing so estimable and eminent a
man ; he accordingly received him with much kindness, excused him
(as being a Protestant) from the ceremonial customary at presenta-
tions at the Papal court, and made him a present of a set of the gold
medals struck during his pontificate.
Having always lived economically and without any display, Tissot
had saved while in Italy a sum of money sufficient for the purchase
of a country-seat, which he intended to be the retreat of his old age.
He had only engaged himself in the Austrian service for a very limited
period ; he had now finished the medical education of a favourite
nephew; and, lastly, as he himself with characteristic playfulness
expressed it, having received the title of ' Immortal,' he thought it
prudent not to run any risk of descending from such a height, and
of outliving (as he might easily do) his apotheosis. He was succeeded
in his professorship at Pavia by the celebrated J. P. Frank, and died
unmarried, on the 16th of June 1797, in his native land, at the age
of sixty-nine. A complete list of his works is given in the ' Biographie
Mddicale,* from which work the above account is taken : of these the
following are the most interesting : ' Tentamen de Morbis ex Manu-
stupratione Ortis,' 8vo, Louvain, 1760; which was translated into
French, and has been frequently republished. * Dissertatio de Febri-
bus Biliosis, seu Historia Epidemisc Lausanensis anni 1755,' 8vo, Lau-
sanne, 1758, 'Avis au Peuple sur sa Santd,' 12mo, Lausanne, 1761,
which was translated into no less than seven different languages, and
in less than six years reached the tenth edition. It has since been
frequently reprinted, and contributed more than any of his other
works to make the author's name known throughout Europe, It
served also as the model and foundation for many similar popular
works in more recent times. ' De Valetudine Litteratorum,' 8vo,
Lausanne, 1766, which was translated into French, and frequently
reprinted, and of which the latest and best edition is that by F. G.
Boisseau, 18mo, Paris, 1826, with notes by the editor, and a memoir
of the author. ' Essai sur les Maladies des Gens du Monde,' which
has also gone through several editions. There is a complete edition
of his works by J. N, Halld, in 11 vols. 8vo, Paris, 1811, with notes
by the editor and a memoir of the author. Besides those original
works Tissot edited at Yverdun, 1779, in three volumes 4to, the
treatise of Morgagni, ' De Sedibus et Causis Morborum per Anatomen
Indagatis,' to which he prefixed a history of the Life and Works of
the author,
♦TITE, WILLIAM, M.P., F.R.S., &c„ architect, was bom in London
near the close of the last century. Although possessing a very exten-
sive city connection, and carrying on a large business, Mr, Tite had not
had opportunities of making his name very generally known by any
important public work prior to the erection of the new Royal
Exchange, His chief work perhaps was the Scotch Church, Regent-
square, London, erected in 1828. In the first open competition of
designs for the Royal Exchange, Mr. Tite was not among the successful
competitors; but it having been decided that neither of the three
designs to which prizes wore awarded was suitable for the purpose
contemplated, the committee resolved to abandon the principle of
open competition, and to name five architects who should be requested
to send in designs. Three of these — Sir R. Smirke, Mr, (now Sir
Charles) Barry, and Mr. Gwilt — declined to compete, leaving the
field to the other two, Mr. Tite and Mr. Cockerell ; and ultimately tho
committee decided in favour of Mr, Tite. The building was com-
pleted in the short space of three years from its commencement near
the close of 1841, at a cost within the estimate of 150,000^, and opened
in state by her Majesty, October 28, 1844. On so well known a
structure it is unnecessary to offer any remarks : it may suffice to say
that its chief architectural feature, the portico of eight Corinthian
columns at the western end, is undoubtedly one of the very finest
porticoes in the metropolis. The work placed the architect in the
foremost rank of his profession, but it remains his only grand work.
His subsequent works have been artistically of a comparatively
unimportant character. The chief are the London and Westminster
bank, Lothbury, executed by him in conjunction with Mr. Cockerell ;
the Vauxhall (original) terminus of the London and South-Western
railway, the terminus at Southampton, and the stations along the line
of the same railway ; the Blackwall terminus of the London and
Blackwall railway; and termini and stations on the Caledonian,
Scottish Central, and various other railways; the London station
of the Woking Cemetery Company, and other buildings for com-
mercial purposes, Mr, Tite has been himself a good deal connected
with commercial undertakings, and lately with political matters.
He is chairman of the North-Devon railway; a director (having
first been for ten years deputy-chairman and managing director)
of the Globe Assurance Company, &c. He was also fur awhile vice-
president of the Administrative Reform Association, under whose
auspices he unsuccessfully contested the borough of Barnstaple, and
in August 1854 was returned as member for Bath, for which place he
was re-elected in April 1857. He is a vice-president of the Institute of
British Architects; he was elected a Fellow of the Royal Society in 1835,
and he is a Fellow of the Society of Antiquaries and of the Geological
Society, Mr. Tite is the author of a ' Report of a Visit to the Estates
of the Hon. Irish Society in Londonderry and Coleraine in the year
1834;' and of the Introduction to a 'Catalogue of Roman Anti-
quities found in the site of the Royal Exchange.'
TITI, SANTI DI, an Italian painter and architect, was bom of a
noble family at Borgo San Sepolcro in Tuscany in 1538, He was a
scholar of Bronzino, and, according to Lanzi, also studied under
Cellini. While at Rome he was employed upon some subjects in the
chapel of the Palazzo Salviati, and painted a St. Jerome in San Gio-
vanni de' Fiorentini, besides executing several works in the Belvedere
of the Vatican. He returned to Florence in 1566, with a reputation
for great ability iu design ; nor was his reputation at all diminished
by the works he there produced, for among them are some of his best,
including his Resurrection and Supper at Emmaus, in Santa Croce ;
of which, and of his other performances, a full accoimt is given by
Borghiui, in his 'Reposo,' It was also at Florence that he chiefly
exercised his profession of architect. The Casa Dardanelli, the Villa
Spini at Peretoln, and his own house at Florence, ai-e enumerated
among his works of that class, but without much commendation. He
ia said however to have displayed much taste in some of his archi-
03
TITIAN.
TITIAN.
M
tectural backgrounds ia painting, in which he also showed groat
knowledge of perspective. His pencil was frequently employed on
merely temporary decorations, either on occasions of solemn funeral
obsequies or splendid festivities, of which latter kind were those wliicli
he painted at the celebration of thv nuptials of the Duke of Brac-
ciano. Sauti died in 1603, leaving a son named Tiberio, who was also
an artist, and who did not long survive him.
TITIAN. TIZIA'NO VECE'LLIO, commonly called TITIAN,
one of the greatest painters of modern times, was born at Capo del
Cadore, a small place on the river Piave in the Venetian state, in 1477,
[the common accounts say 1480]. He was of the ancient family of
Vecellio, of which was San Tiziano, bishop of Uderzo. At the age of
about ten young Titian was sent by his father to Venice to an uncle,
to be placed with some competent painter. He was first placed with
Sebastiauo Zuccati, and shortly afterwards with Gentile Bellini, whom
however he also soon left for Giovanni his brother, the most eminent
painter of his time at Venice. Titian soon surpassed his master.
His early works, in themselves extraordinary, are infinitely more so
when compared with the works of the leading artists of Venice of his
time. His early portraits are finished with remarkable care, drawn
iu excellent taste, and some of his pictures rival the works of the
Dutch and old~ German artists iu finish : there is iu the gallery of
Dresden a picture of the Tribute Money of this description. The
great improvement in the works of Titian upon those of Giovanni
Bellini and his school has been considered to be in a great degree
derived from the works of Giorgione di Castel Franco who had appro-
priated much of the style of Lionardo da Vinci. [Giorgione.]
Giorgione was two years the senior of Titian, and their works were so
much alike that they could not always be distiuguisbed ; but the
merit of introducing the new style into Venice belongs to Giorgione.
These two painters were fellow-pupils, and for some time friends,
until, upon an occasion when Titian was appointed, or Giorgione
employed him, to assist him in some frescoes for the new foudaco de'
Tedeschi (German warehouse), the portion executed by Titian was
preferred to that of Giorgione by some of his own friends, and a jealousy
arose between them.
At the death of Giovanni Bellini in 1512, Titian was employed by
the state to complete a work in the Sala del Gran Consiglio of the
Homage of Frederic Barbarossa to Pope Alexander III., which he had
left unfinished. Titian completed the picture, but he made many
alterations in it ; the senate was however so well satisfied with the
work, that they presented him with the ofiice of La Senseria, with a
salary of about 300 crowns per annum, by which he was obliged to
paint for eight crowns the portrait of every doge created in his time,
to be placed in the palace of St. Mark. He painted by virtue of this
place the portraits ■ of Pietro Lando, Francesco Donate, Marcantouio
Trevisano, and the Venieri : he was unable to paint the portraits of
the last two doges of his time on account of the infirmities of age.
In 1514 Titian painted his Bacchus and Ariadne, and other Baccha-
nalian and similar works in the palace of Alfonso I., duke of Ferrara,
which display his extraordinary power of seeing and imitating nature
to a remarkable degree. It was upon a door in an apartment of this
palace that he painted his celebrated picture of the Tribute Money
noticed above : it represents a Pharisee showing Christ a piece of
money, who appears to be asking h^m the question, " Whose is this
image and superscription ? " The figures are half-length and of the
natural size. He painted also at the same time the portrait of the
duke with his hand resting upon a cannon, and one of the Signora
Laura, who afterwards was married to the duke. All these pictures
are amongst Titian's finest works; and Michel Angelo, when he first
saw the duke's portrait, is said to have exclaimed, " Titian alone is
worthy of the name of a painter." Titian became acquainted at
Ferrara with Ariosto, and painted his portrait. The poet compliments
the painter iu his ' Orlando Furioso ' (c. xxxiii. 2) : —
'* Bastiano, liafael, Tizian, ch'onora
Non men Cadore, che quel Venezia e Urbino."
In 1516, shortly after he returned from Ferrara to Venice, he painted
in oil his famous picture of the Assumption of the Virgin, for the
great altar of the church of Santa Maria gloriosa de' Frari : it is now
in the Academy of the Fine Arts at Venice. This picture is very
large, and the figures are larger than life : in the highest part is God
the Father between two angels ; in the middle the Virgin ascending,
accompanied by angels ; and on the ground are the twelve apostles
witnessing the miracle. It is certainly one of the finest pictures in
the world, grand in composition and design, and in colouring wonder-
ful. Titian never surpassed it in these respects by any of his later
works.
This and the works Titian painted at Ferrara so spread his reputa-
tion, that he was invited by Leo X. to Home. Kaffaelle also entreated
him to make the -journey ; the deaths however of the pope and
EafFaelle in 1520, put an end for a time to the project. He was invited
likewise about the same time by Francis I., whose portrait he painted,
to France ; an invitation which he showed no disposition to accept.
In 1528 he painted his celebrated picture of St. Peter Martyr, for
the chapel of that saint, in the church of SS, Giovanni e Paolo. This
work has been extravagantly praised by many critics, both for its
arrangement and execution ; the landscape is particularly excellent.
Algarotti calls it a picture without a fault : its general truth and
appearance of reality are not its least remarkable properties. This
picture, as well as the Assumption already mentioned are painted in
a much freer style than Titian's earlier works. Aretin wrote in 1536
a letter to Tribolo, the sculptor, iu praise of the St Peter Martyr, by
which we learn that this sculptor and Benvenuto Cellini were strongly
impressed with its extraordinary excellence. It is full 16.^ feet high,
by nearly 10 wide, was painted upon wood, but was transferred to
canvas by M. Haquin, at Paris, in 1799, whither it had been taken
with many other fine works : it was sent back to Venice in 1815.
In consequence of the St. Peter Martyr, Titian received a commis-
sion to paint the Victory of the Venetians over the Janissaries in the
great council-chamber at Venice, which was considered the best
picture there : it perished by fire, but there is a print of it by Fontana.
Another celebrated picture which Titian painted about the same time
was his St. Sebastian, for the church of San Nicolo de' Frari, at
Venice, but now in the Vatican at Rome. This work also has been
the subject of much eulogy, especially for its colouring : it has been
engraved by Lefevre.
Notwithstanding Titian's great reputation, he lived in a very humble
way until he obtained, through his friend Aretin, the notice and the
patronage of the emperor Charles V. In 1530 Charles sent for him to
Bologna to paint his portrait : he painted that of Ippolito de' Medici
at the same time, besides portraits of many other distinguished person-
ages ; and he received also several other commissions from the
emperor. Titian went from Bologna to Mantua with the Duke
Fx'ederico Gonzaga, for whom he executed many works ; amongst
them eleven of the twelve Caisars. Domitian was painted by Bernar-
dino Campi : they were lost in 1630 at the plundering of Mantua, but
they have been often copied. In 1532 Titian went again to Bologna,
appears to have accompanied Charles into Spain, and remained there
three years, during which time he executed many celebrated works ;
but there will be occasion to mention this subject lower down. In
1536 al.-o Titian appears to have met Charles at Asti, after his return
from Africa.
In 1537 he painted for the church of Santa Maria degl' Angeli, at
Murano, an Annunciation, which was rejected on account of the price,
500 crowns (about 100 guineas); and he presented the picture to
Charles V., who sent him 2000 crowns in return. In 1541 he painted
the Descent of the Holy Ghost upon the Apostles for the altar of the
church of Santo Spirito ; and three others, in oil, for the ceiling, the
Sacrifice of Abraham, David and Goliah, and the Death of Abel.
Copies were afterwards substituted for these works, which were re-
moved to Santa Maiia della Salute ; and in 1543 he painted a picture
of the Virgin and San Tiziano for his native place, in which ho intro-
duced his own portrait. In the same year he was invited by Pope
Paul III. to Bologna, and painted his portrait there, a celebrated
picture, with which the pope was so much pleased, that he requested
Titian to go with him to Home ; but the painter was obliged to decline,
on account of an engagement with the Duke of Urbino, for whom he
painted several pictures.
A letter from Aretin to Titian, of the year 1645, shows in what
great favour Titian stood with the government of Venice : it speaks of
his large pension, and the many imposts from which he was exempted.
In the same year there was a false report of his death, which appears
to have distressed the emperor, from a letter which Titian himself
wrote to Charles to contradict it. In this year also Titian visited
Rome, and painted Paul III. again, with the Cardinal Famese and
Duke Octavio Famese in one group. Northcote terms this picture
one of the finest examples of portrait in the world; and he relates that
he and Fuseli saw it together at Capo di Monte, at Naples, and the
latter exclaimed upon seeing it, " That is true history."
Aretin wrote several letters to Titian whilst he was at Rome, one of
which, dated October, 1545, he finishes by requesting him not to be so
lost in contemplation of the Last Judgment, in the Sistine chapel, as
to forget to make haste back, and be absent from him and Sansoviuo
all the winter. Michel Angelo visited Titian with Vasari in the
Belvedere, whilst he was painting a picture of Jupiter and Danae, and
Vasari says he praised the picture very much in the presence of
Titian : and he afterwards spoke very highly of his colouring and
execution ; but he observed that it was a pity that the Venetian
painters had not a better mode of study, and were not early initiated
in sound principles of drawing: and he added, that if Titian had
been as much assisted by art as. he was by nature, nothing could
surpass him.
Titian appears to have left Rome in May 1546 ; and he visited
Florence on his return to Venice. Vasari however says that after the
death of Sebastian del Piombo, in 1547, Pope Paul III. offered his
office of keeper of the seals of lead to Titian, which however Titian
declined, and this has led some writers to suppose that Titian must
have been then in Home, but it is most probable that the oflTer, if
1547 he was invited by the emperor to Augsburg, whither he went in
the beginning of 1548. In 1650 he went again to Charles to Augsburg
and in 1553 is said to have accompanied him into Spain, where accord-
ing to some accounts, he remained three years, but this is certainly
incorrect. It was at Barcelona that Charles created Titian count
95
TITIAN.
TITSINQH, ISAAC.
palatine of the empire and mode him knight of the order of St. lago.
In the patent of nobility given at Barcelona, as Ridolfi eays, in 1553,
which ought probably to be 1535, Titian is styled besides count pala-
tine, knight, and count of the sacred Lateran palace, and of the
imperial court and consistory. Charles left Barcelona in 1542, and did
not return until 1556 : for this reason Bermudez concludes that 1553
in llidolh has originated from an error of the copyist for 1636. Ber-
mudez supposes that Titian left Spain in May 1535, when Charles
went to Africa, and that he went to that country in 1532, after he
painted Charles for a second time at Bologna. Titian painted several
works in Spain; but of those which were in the royal galleries it is
not exactly known which were painted in Spain, or which were sent
there from lUly, both to Charles and to Philip, or which were
purchase.! after the death of Titian. There are however in Spain
several of Titian's masterpieces: a Sleeping Venus, "a matchless
deity," as Cumberland terms it, which was saved from the conflagra-
tion of the Prado, in the time of Philip IV., by which several of
Titian's and other valuable pictures were destroyed; also two cele-
brated groups from the Ludovisi palace at Rome, one of Bacchanals,
the other of Cupids ; a Last Supper in the refectory of the Escurial,
painted for Philip II. ; Christ in the Garden, and St. Margaret with
the Dragon. The Last Supper was sent by Titian to Philip in 155-1 ;
and in an accompanying letter he states that he had been occupied
seven years over it, during wliich time, to use his own words, he had
liiboured almost continually upon it : this is another testimony tliat
Titian was not in Spain so late as 1553 and the following years. In
this letter Titian complains of the irregularity with which two grants
made to him by the emperor, in 1541 and 1548, were paid, amounting
to 400 crowns per annum. Philip answered it in 1558, and gave
peremptory orders that the sums should be duly paid, with the follow-
ing admonition, in his own handwriting, to the governor of Milan :
" You know how I am interested in this order, as it affects Titian;
comply with it therefore in such a manner as to give me no occasion to
repeat it." These 400 crowns, together with the 300 granted by the
state were alone suflBcient to support Titian in a comfortable manner ;
and the income derived from his works enabled him to live in great
affluence : his house was a place of resort to the nobles of Venice.
He painted many pictures for Philip. In a letter addressed by Titian
to Philip, shortly after Philip married Queen Mary of England, Titian
mentions a Venus and Adonis, which he sent him at the same time,
also a DanaiJ, which he had previously sent, and a Perseus and Andro-
meda, and a Medea and Jason, which he was about to send ; likewise
a religious piece, which he had bad ten years in hand. He does not
picture of the Martyrdom of San Lorenzo for Philip II. : it is a night
scene, and the whole light of the picture is from the fire, two torches,
and a ray of light from heaven. In this picture, though he was then
old, Titian has displayed a power of composition and design equal to
his colouring, and has much surpassed every other master who has
painted this subject : he repeated the picture, with some slight
alterations in the background, for the church of the Jesuits at Venice.
Titian often repeated his pictures; but the principal part of the
copies were painted by his scholars : he finished them only, but he
generally introduced some alterations in the backgrounds.
In 1566 Vasari visited Titian, and, although he was then eighty-nine
years of age, he found him with his pencil in his baud, and derived
great pleasure from his conversation. T?he pencil of Titian however was
active for still ten years, although the pictures he produced at this
time were not calculated to add to his reputation : they are extremely
careless and slight in their execution. He died of the plague in 1576,
aged ninety-nine, with the reputation of the greatest colourist and
one of the greatest painters that ever lived ; and having himself
enjoyed a European fame for upwards of seventy years. He was
buried, by express permission of the senate (which, as he died of the
plague, was necessary), without pomp in the church of Santa Maria
gloriosa de' Frari, where his famous picture of the Assumption of the
Virgin stood before it was removed to the Academy ; but no monument
has yet been raised to him, though a splendid one was projected in
Canova's time.
Much has been said by the Florentines, and some recent critics of
different schools, in disparagement of the design of Titian ; yet, as far
as regards propriety of design, there can be no comparison between
the earlier and best works of Titian and those of the anatomical
school of Florence in the latter half of the sixteenth century. In the
works of Titian there is no ostentation of any kind whatever; no
artifice. In composition, in design, in chiar'oscuro, and in colouring,
he sought truth only, and that according to his own perception of it.
It is generally allowed that for the pictoiial imitation of nature,
without any addition or selection, Titian has surpassed all the other
great painters of Italy ; but in invention, composition, and design he
was inferior to many of the great painters of Home and of Florence;
yet in design he has had no superior in the Venetian school. His works
are purely historical, or simple pictures of recorded facts, and ho is
said to have always painted from nature. It is in colouring that Titian
is pre-eminent : the same grandeur of colour and effect characterise
everything that he painted — whether in the figure, in the landscape, in
the draperies, or in other accessories. His chiar'oscuro is true, because
in his works it is a part of the colouring, but it never constitutes, as
in some of the works of Correggio, an independent object. Titian's
object appears, from his works, to have been to produce a faithful
imitation of every appearance of nature in what he represented —
thus we find in all his best pictures that infinite variety of local tones
which appear in nature. He was one of the first who commenced the
practice of glazing. He excelled in women and in children : his
numerous Venuses, as they are called, are well known : of these
perhaps the most richly and transparently coloured is that at Dresden ;
there is a duplicate of this picture in the Fitzwilliam Museum at
Cambridge. In his naked men he was not so successful : perhaps of
these the best is his John the Baptist, in the Academy at Venice,
formerly in the church of Santa Maria Maggiore, There are two
other remarkable pictures by Titian in the collection of the Venetian
Academy which have not been mentioned — a Presentation in the
Temple and a Deposition from the Cro'S. The former, originally
belonging to the old church della Carith,, is an aduiirable example of
Titian's simple and natural style of composition ; it contains many
portraits: the latter is a remarkable specimen of the surprising bold-
ness of touch, yet truth and brilliancy of colouring, which distinguish
the best of his latest works.
There is no list of the works of Titian, and it would not be an easy
task to make one. His portraits are extremely numerous, and in this
department he is almost universally considered to have surpassed all
other painters, not excepting Vandyck. There is at Windsor a picture
said to be the portrait of Titian and Aretin, or some senator, by
Titian, which cannot be too highly praised : it is certainly, for
colouring, one of the first pictui-es in the world. There are several
other admirable pieces by Titian in England : two in the Bridgewater
Gallery, of Acta3on and Calisto ; the Princess Eboli with Philip II., at
Cambridge, from the Orleans Gallery, the repetition of the Dresden
Venus mentioned above; and the Coruaro Family, at Northumber-
land Hous3. There is alt^o in the Louvre at I'aris a remarkably fine
picture for the composition of colour, representing the Entombment
of Christ : it is a repetition of the picture of the same subject iu the
Manfrini palace at Venice. The National Gallery contains seven
pictures attributed to Titian, of, which the Bacchus and Ariadne, and
Venus and Adonis are brilliant examples of his manner of painting
mythological subjects.
Titian, Aretin, and Sansovino the architect, were great friends, and
were almost inseparable when at Venice. Titian painted Aretin
several times; he is also said to have painted several portraits of
Ariosto, who was likewise his fi'iend : there is one in the Manfrini
palace at Venice. Considering Titian's great reputation, little is
known concerning his private life, but he appears to have been of
an amiable disposition and agreeable conversation : he seems however
to have been particularly susceptible of jealousy. He is said to have
been even so jealous of his own brother Francesco Vecellio, that he
induced him to give up painting and to follow the occupation of a
merchant; his reputed jealousy of Tintoretto as a boy has been
mentioned. [Tintoretto.]
His biographers Ridolfi and others relate several anecdotes showing
his intimacy with Charles V., and the respect that the emperor had
for him. Upon one occasion, when Charles was present, whilst he
was painting, Titian let his brush fall, and the emperor immediately
picked it up and gave it to Titian, saying, " Titian is worthy of being
served by Csesar " (" Titiano e degno essere servito da Cesare").
Northcote the painter wrote a Life of Titian, or, as some say, got
Hazlitt to write it for him: 'The Life of Titian, with Anecdotes of
the Distinguished Persons of his Time,' 2 vols. 8vo, London, 1830.
This book of 784 pages is a mass of matter thrown together without
judgment or arrangement, and it contains several inaccuracies and
some contradictions. It consists of two reviews of Titian's life, which
are distinct lives; the second review, 'from Ridolfi, Ticozzi, and
others,' beginning with ch. xxviii. or page 73 of the second volume, is
the better portion of the work, but does not appear to have been
written by the same hand that wrote the other portion.
To be enabled to appreciate fully the powers of Titian it is neces-
sary to examine his works at Venice; after Venice he is seen to most
advantage in Madrid. Bermudez has given a kind of list of his public
works in Spain, in his 'Dictionary of Spanish Artists;' he enumerates
about eighty. Titian's scholars were not very numerous : the best
were Paris Bordone, Bonifazio Veneziano, Qirolamo di Tiziauo, and his
son Orazio Vecellio. His imitators were more so, for they include to a
certain extent all the great painters of Venice of his time, who
acquired a reputation subsequently to his own. Titian is said to
have engraved on copper and on wood.
There were several other painters of the family of the Vecelli, for
whom see Veceltjo.
TITSINGH, ISAAC, one of the most able civilians in the Dutch
East Indian service during the last century, was born at Amsterdam
in 1740. He entered the service of the East India Company of Hol-
land at an early age, and rose to the rank of counsellor. His naturally
vigorous constitution defied the pestilential effects of the climate of
Batavia, where in the course of seventeen years he saw the entire body
of his colleagues twice renewed. He was sent as supercargo to Japan
in 1778. The war which then raged prevented the despatch of the
ship sent annually from Batavia to the Dutch factory at Desima, and
Titsingh was in consequence detained there for several years. He did
97
TITTMA.NN, JOHANN AUGUST.
TITUS, FLAVIUS VESPASIANUS.
98
tot quit Japan till 1784. After his return to Batavia he was appointed
governor of the Dutch factory in tho vicinity of Chandernagore : how
long he filled this office is uncertain.
In 1794 Titsingh was appointed by the government at Batavia chief
of the embiissy which Van Braam, hoping to be himself appointed
mission left Canton on the 22nd of November 1794, and reached that
city on its return on the 11th of May 1795. The ill-health of Titsingh
during the greater part of his residence at Pekin caused t,he discharge
of the functions of ambassador to devolve in great measure on Van
Braam. Not long after the termination of this mission Titsingh
returned to Holland, after a residence of about thirty-one years in
the East. The involuntary prolongation of his residence in Japan had
enabled him to obtain a greater amount of information relative to
those islands than his predecessors, and the friendships he had con-
tracted with several of the nobles enabled him to procure, at a later
date, by their good offices, material additions to the collections he had
made himself He was acknowledged both by the Japanese and
Chinese to possess a knowledge of their customs and manners rare in
a European. He was esteemed by his colleagues for his business
talents ; and the literati of Europe who had applied to him for infor-
mation had ever found him as courteous and liberal as he was intel-
ligent : consequently great additions to our knowledge of Japan were
ever in a great measure disappointed. With the exception of infor-
mation which he supplied to Marsden, De Guignes and others, nothing
appeared during his life ; and after his death, by a fever which he
neglected, in February 1812, his collections were dispersed; only a
portion of his manuscripts, maps, and curiosities were ultimately
recovered. M. Nepven, who had become the purchaser of the frag-
ments, published in 1819, in two vols. 8vo, ' C^r^monies usitdes au
Japon pour les Manages et les Fun^railles, suivies de Details sur la
Poudre Doxia, et de la Preface d'un livre de Confoutzde sur la Pi^t^
Filiale,"traduit du Japonais par feu M. Titsingh.' In the introduction
to the Memoirs the author states that many of the most distinguished
Japanese are fully aware of the advantage their country would derive
from an extended intercourse with foreigners. In 1820 M. Abel
Rdmusat published in 8vo, from the manuscripts of Titsingh, M^moires
et Anecdotes de la Dynastie regnante des Djogouns, souverains du
Japon, avec la Description des Fetes et Cdr^monies observees aux
differentes dpoques de I'annee Ji la cour de ces Princes, et un Appendice
contenant des Details sur la Poesie dea Japonais, leur Mani^re de
diviser I'Ann^e, &c.' An English translation of these two works, by
Frederic Shoberl, was published in 1822. The volumes edited by M.
R^musat, and the English translation, contain a catalogue of the books,
printed and in manuscript, the maps, plans, coins, &c., collected by
Titsingh. Among the manuscripts are his journal of travels from
Canton to Pekin ; copies of letters addressed by him to various
persons during the years 1790 to 1797.; forty-six autograph letters
addressed to him by Japanese functionaries and Roman Catholic mis-
sionaries; thirty- five autograph letters addressed to him by Volney,
De Guignes, senior, and other eminent literary characters; and an
exposition of the official conduct of M. Titsingh. The twenty-fourth
volume of the ' Annales des Voyages ' contains an account of the island
of Yesso, translated from the Japanese by Titsingh, and a ' Notice sur
Japon,' in Charpentier Cossigny's 'Journey to Bengal,' contains a
rather inaccurate report of the substance of conversations with him
respecting that country. The important work the * Japanese Ency-
clopaedia,' in the ' Biblioth&que du Roi,' at Paris, was obtained from
Titsingh.
TITTMANN, JOHANN AUGUST HEINRICH, one of the most
distinguished German theologians of modern times, was born on the
1st of August 1773, at Langensalza, whei'e his father, Carl Christian
Tittmann, was then preacher. Young Tittmann was originally of a
very weakly constitution, but he gained strength as he grew older,
especially from the time thathe lived at Wittenberg, where his father
was appointed praepositus and professor in the year 1775. His extra-
ordinary talents enabled him to enter upon the study of theology and
philosophy at Wittenberg as early as 1788, after he had the year
before published a Latin essay, ' Do Virgilio Homerum imitante,'
Wittenberg 1787. On completing his studies there, he went to
Leipzig in 1792, where he began his career as academical teacher on
the 15th of May 1793. His talents and the extensive knowledge he
possessed at this early age would have made him the first theologian
of his time, if he had not been frequently drawn away from his regular
studies, and occupied with different subjects. Nevertheless he dis-
tinguished himself so much, that in 1795 he was appointed morning
preacher (Friihprediger) to the university, and the year after professor
extraordinary of philosophy, and in 1800 professor of theology. In
1805 he was made a doctor of divinity, and obtained the fourth ordinary
professorship of theology, and in 1818 he became first professor of
theology in the university of Leipzig. During the last year of his life
he was dean of the cathedral of Meissen. He died, in consequence of
a cold he took in 1828, and of which he never recovered, on the 31st
of December 1831.
As an academical teacher Tittmann distinguished himself by his
acuteness, sound judgment, and by the simplicity and clearness with
which he treated his subject. It was perhaps owing to the variety of
BIGG. DIV. VOL. VI.
subjects on which he had tried his strength, that iu his later years he
was competent to undertake the most varied busineBS in which he was
employed by his government. At the congress of Vienna, which he
attended for some time, he spoke with great frankness, and particularly
exerted himself to realise his favourite plan of uniting the German
Protestants, and giving to their body a new ecclesiastical constitution.
But his object was not attained. During the last years of his life he
was a member of the first chamber of the Saxon deputies, in which
he represented the university of Leipzig, and often exercised great
influence by his ability and his powers as a speaker.
The numerous writings of Tittmann are distinguished by great
clearness of style, those written in German, as well as those in Latin.
The following are the most important for the theological student :— •
' Encyclopiidie der Theologischen Wissenschaften,' Leipzig, Svo, 1798 ;
'Theocles, ein Gesprach iiber den Glauben an Gott,' Leipzig, Svo,
1799; ' Ideen zu einer Apologie des Glaubens,' Leipzig, Svo, 1799;
' Theon, oder fiber unsere Hoffnungen nach dem Tode,' Leipzig,
1801; 'Lehrbuch der Homiletik,' Breslau, Svo, 1804; ' Pragmatische
Gesohichte der Theologie und Religion in der Protestantischen Kirche
wiihrend der zweiten Halfte deslSten Jahrhunderts ' (of this excellent
work only the first volume appeared, Breslau, Svo, 1805) ; ' Ueber
Supranaturalismus, Rationalismus, und Atheismus,' Svo, Leipzig, 1816 ;
' Ueber Vereinigung der Evangelischen Kirchen,' Leipzig, 1818; 'Die
Evangelische Kirche im Jahre 1530 und 1830,' Leipzig, Svo, 1830.
Tittmann also edited the Greek text of the New Testament, Leipzig,
12mo, 1824, which has often been reprinted, and Zonaras and Photius's
Greek Lexicon, Leipzig, 4to, 1808 ; but of this work only two volumes
appeared, which contain the Lexicon of Zonaras. He also wrote' a great
number of Latin dissertations in programmes and on other occasions,
which were edited after his death by Hahn, under the title, ' Opuscula
varii Argumenti, maximam partem dogmatici, apologetic!, et historici,*
Leipzig, Svo, 1833. Another Latin work, 'De Synonymis in Novo
Testamento,' was edited by Becher, Leipzig, 8vo, 1832.
TITUS, FLA'VIUS VESPASIA'NUS, the son of the Emperor
Vespasianus, was born on the 29th of December, a.d. 40. He received
his education together with young Britannicus, who was poisoned by
Nero in a.d. 55, and &8 Titus fell dangerously ill after the death of his
unfortunate friend, it was said and believed that he had drunk a part
of that deadly potion by which Britannicus perished. Titus after-
wards erected two statues to the memory of the companion of his
youth. Possessed of uncommon beauty and vigour, and extraordinary
talents, Titus distinguished himself at an early age. The first cam-
paigns which he made as tribunus militum were in Britannia and
Germany. He first married Aricidia Tertulla, the daughter of a
Roman knight, and after her death, Marcia Furnilla, who was of a
noble family, but from whom he was divorced some time after she had
borne him a daughter. Titus became afterwards quajstor. The Jews,
having been oppressed by Gessius Florus, i-evolted in a.d. 66, and
defeated Cestius Gallus, the proconsul of Syria, but they were beaten
by M. Licinius Mucianus, the new proconsul of Syria, and T. Ves-
pasianus, the father of Titus, who was the commander of the Roman
army, which consisted of three legions. One of these legions was
commanded by Titus, who showed as much military skill as personal
courage, especially in the siege and capture of the towns of Taricheae
and Gamala (a.d. 67). During his sojourn iu Palestine he fell in love
with Berenice, the daughter of Herod Agrippa. [Berenice (6).]
In the mean time the Emperor Nero was murdered, and Galba suc-
ceeded (a.d. 69). In consequence of this event, T. Vespasianus sent
his son Titus to Rome, iu order to gain the favour of the new emperor.
Perhaps also A^'espasianus wished to be informed of Galba's intention
with regard to the war in Palestine, the command of the forces
employed there being an office by which Vespasianus had acquired
great influence in the East. (Tacitus, ' Hist.,' ii. 1, and the notes to
this passage in the edition of Gronovius, ii., p. 127-) The people said
that Titus had some hope of being adopted by Galba, who was old and
without issue; but although this motive of his going to Rome is
rejected by Tacitus, the mere existence of such a rumour proves that
at Corinth he was informed that Galba had been murdered (15th of
January, 69), and that the imperial power was disputed by Vitellius
and Otho. This event perplexed him. His commission being to con-
gratulate Galba, he could not expect, to be well received by Vitellius,
by whose instigation Galba had been massacred; nor did he deem it
prudent to adhere to either of the imperial rivals before he had taken
the advice of his father. He therefore returned to Judaea. There
was a rumour that his love for Berenice was the secret cause of his
return ; but however strong his passion was, it never prevented him
from doing his duty. On his way from Greece to Syria he landed on
Cyprus, and there consulted the oracle in the temple of Venus of
Paphos, The answer was favourable with regard to his voyage, and
highly flattering to his ambition : Sostratus, the priest of the temple
and the reporter of the oracle, promised him the empire. (Tacitus,
' Hist.,' ii. 2-4 ; Suetonius, ' Titus,' c. 6.)
Titus was one of the leaders of the new revolution by which
Vitellius lost his power a short time after his victory over his com-
petitor Otho at Brixellum. Full of filial admiration for the character
of his father, Titus endeavoured to remove the only obstacle to his
succession, which might have frustrated their plans, notwithstanding
H
99
TITUS, FLAVIUS VESPASIANDS.
TITUS.
100
VespasiatiuB was at the bead of three legions and a strong body of
auxiliaries. This obstacle was a serious miBUuderstanding whicli
existed between Vespasianus and Muscianus, the proconsul of Syria.
Titus succeeded in reconciling them. Their differeuce had chiefly a
political character, yet Titus, by the mildness of his wanner and by the
modesty of his persuasion, brought together two highly-gifted men
who were divided by tho most iutractablo of passions. Supported by
Mucianus, by Tiberius Alexander, and by Titus, Vespasianus was pro-
claimed emperor by tho army in the East, while his brother Flavins
Sabinus occupied for him the Capitol in Home, and compelled Vitel-
lius to lay down the imperial diadem. [Vesi'asiancs ; Txbeuius
Alexakoeb ; VxTKLLius.] Vespasianus left Judaea for Rome, and the
command of the army of Juda;a and the continuation of the war
devolved upon Titus, Domitianus, tho younger brother of Titus,
having incurred the displeasure of his lather, Titus interceded for
him with brotherly aifection. (Tacitus, 'Hist,' iv. ol, 62.)
The army in Judaea, of which Titus w.os now tho commander, con-
sisted of six legions, twenty cohorts of allies, eight corps of cavalry,
the troops of the Kings Agrippa and Sohemus, the auxiliaiies of King
Autioohus of Commagene, and a small body of Arabs. After a long
siege, Jerusalem was taken by storm ; the whole population, more
than 600,000 men, was massacred; and the remainder of the Jews
were dispersed over the world (2nd of September, a.d. 70). In this
memorable siege Titus distinguished himself both as a general and as
a soldier, and it is said that he killed twelve men of the garrison with
his own hand. In the same year Titus was created Cassar by Ves-
pasianus, whose colleague he was in his first consulship ; and he was
again consul in the years 72, 74, 75, 76, 77, and 79. Vespasianus
however recalled his son from Judsea. A rumour was spread that
Titus secretly aimed at making himself master of the East, and this
So universally was Titus beloved, that the army implored him
either to stay with them, or at least not to go without them ; but he
obeyed the commaud of his father, and by Lis speedy return proved
that those rumours were entirely unfounded. He celebrated a triumph
together with Vespasianus, for their victories over the Jews, in com-
memoration of which a triumphal arch was erected, which is still one
of the finest monuments of that kind existing in Rome. Titus was
likewise tribune with his father, who esteemed him so much, that he
allowed him not only to write letters in his name, but also to draw up
the imperial edicts. (Suetonius 'Titus,' 6.) During the reign of
Vespasianus, various high functions were successively conferred upon
Titus, whose character however seems to have been somewhat altered
by the influence of the general corruption of the capital. He was
charged with acting rashly : he subjected himself to the reproach of
having ordered the murder of Caecina, which was an act of cruelty, for
though Caecina was guilty of treason, he had not been legally sentenced
(Suetonius, 'Titus,' 6); and he was generally reproached for taking
money from those who solicited his intercession with the emperor.
On the other side however he remonstrated with his father on those
measures which this very economical prince adopted for the purpose
of improving the finances, which were exhausted by the dissipation of
VitelliuB. He was also charged with love of women. But he ordered
Berenice, who had followed him to Rome, to go back to Judaea, and he
thua proved once more that his passion for lier did not prevent him
from doing his duty. The consequence of this was, that the Romans,
who, by the example of Tiberius, Caligula, and Nero, knew that the
virtue of exalted men is exposed to great temptations and strange
changes, feared that Titus would become a new proof of the truth of
their experience.
But no sooner did Titus become emperor by the death of Ves-
pasianus in A.D. 79, than he showed that all these fears were unfounded.
His virtuous conduct was the subject of general admiration. During
bis short reign the empire was visited by great calamities. An erup-
tion of Vesuvius destroyed the towns of Herculaneum, Stabiae, and
Pompeii, and carried ruin over the fertile coast of Campania (August,
79) [Flint] : in the year 80 a conflagration broke out in Rome, which
lasted three days, and destroyed a great part of this city ; the build-
ings on the Campus Martins, the Capitol, the library of Octavianus,
were laid in ruins, and the Pantheon was damaged; and no sooner
had the people recovered from their consternation than the plague
broke out, of which 10,000 persons died every day. Titus supported
bis unhappy subjects with the greatest liberality; he exhausted his
treasures, and he ordered the property and estates of those who had
perished without leaving heirs, to be distributed among the sufferers,
although the property of such persons belonged to the fiscus, or the
emperor's private purse. His liberality was so great that his friends
reproached him for it; he answered, that it was not just that any-
body should leave the emperor mth a sorrowful eye. He punished
severely and exiled to the small barren islands in the Mediterranean
those who followed the profession of false accusers [Tibekius Claudius
NehoJ ; and he dislikcfl the punishment of death so much, that he
used to say that he would rather die than cause the death of others.
Two patricians conspired against him, but he did not punish them : be
only said, " Do not do it again ; Providence alone distributes crowns"
(Suetonius, 'Titus,' 9); and he theu invited them to accompany him
to the amphitheatre. He acted with the same generosity towards his
brother Domitianus, who was guilty of more than one conspiracy
against his brother. Ho gained all hearts by his extreme affability,
which however was always accompanied by dignity ; and ho delighted
the Roman people with splendid entertainments, giving them amongst
others the spectacle of five thousand wild beasts fighting witii each
other in the Colosseum, or Flavian amphitheatre, which was finished
by his order, the construction of it having been commenced under
Vespasianus.
During the r^igQ of Titus, Agricola restored tranquillity to Britain,
and penetrated as far as the Frith of Tay. (a.d. 80.) In the following
year he constructed the wall between the rivers Qlota and Bodotria
(the Frith of Clyde and the Frith of Forth), in order to protect
Britain against the invasions of the Caledonians.
In order to recover his broken health Titus retired, in a.d. 81, to a
villa in the neighbourhood of Reate, which belonged to his family,
and where Vespasianus had died. Here he was attacked by acute
fever, and died on the 13th of September 81. It was said that bis
cause of his death by advising the use of improper remedies. On his
death-bed Titus exclaimed that he died without regret, except fur one
act, which however he did not specify. The news of his death reached
Rome in the evening, and the senators assembled in the same night,
anxious to know each other's hopes and fears with regard to tho
unworthy successor of Titus, Domitianus. The consternation of the
people was general, for they had lost him to whom they had given the
name of " the delight of the human race."
(Josephus, Jewiih War, vi. 6, &c. ; Dion Cassius, IxvL 18, &c. ;
Aurelius Victor, De Cwsaribv^, 10 j Eutropius, vii. 14.)
British Museum.
Coin of Titus.
Actual size. Copper.
Weight 398-7 grains.
TITUS. Little is known of the personal history of Titus, to whom
the epistle of St. Paul is addressed. His name is not even mentioned
in the Acts of the Apostles, and all authentic information about him
is derived from the Epistles of St. Paul. From these it appears that
Titus was converted by St. Paul, by whom he is called " his own son
after the common faith" (i. 4), but when and where is not recorded.
Accordingly there are various conjectures on this subject. This we
know for certain, that Titus was (Acts, xv. ; Gal., ii.) with St. Paul in
Antioch before the first Council was holden at Jerusalem, and that he
was one of the party sent by the Church at Antioch to consult the
Apostles at Jerusalem, op the question whether it was necessary for
the Gentile converts to submit to circumcision " after the manner of
Moses." To this rite the Judaising Christians at Jerusalem were
anxious that Titus should submit ; but St. Paul (Gal,, ii.) informs us
that he firmly refused to do so. After the Council it would seem that
Titus returned with St. Paul to Antioch, and subsequently accom-
panied him on some of his travels.
At any rate, from the expression in 2 Cor., viii, 23, it appears almost
certain that Titus assisted St. Paul in preaching the Gospel at Corinth.
From 1 Cor., xvi. 8, compared with 2 Cor., vii., it is not improbable
that Titus was also with St. Paul during his long residence at Ephesua
(Acts, xix. 10), and that he was selected to be the bearer of the first
Epistle to the Corinthians, which was written by St. Paul at Ephesus.
On his return from Corinth, whatever might be the occasion of the
visit alluded to in 2 Cor. vii., Titus met St. Paul in Macedonia, and
gave him such an account of the Corinthian Church, and of the eSect
produced by his first letter to it, as gave him the highest satisfaction.
(2 Cor., vii. 6-13.) Titus also appears to have been the bearer of the
apostle's second letter to the Corinthians, when he was charged to
excite them to finish their collections for the poor converts in Judtea,
which they had begun during his former visit. From 58, when we
suppose him to have been the bearer of St. Paul's second epistle to
the Corinthians, to 62, we hear nothing of him ; in the latter year, in
all probability, he was left by St. Paul in Crete, " to set in order the
things that were wanting, and to ordain elders in every city." (Titus,
i. 4.) This year was the date of St. Paul's release from his first con-
finement at Rome, when he is supposed to have touched at Crete, and
made some converts there, on his way from Italy to Judaea. Subse-
quently to this, Titus was requested by St. Paul (iii. 12) to visit him
at Kicopolis in Epirus, and it seems that he was also with him during
his second residence at Rome. (2 Timothy, iv. 10.) We have no
certain information as to the time and place of Titus's death ; but
according to an ancient tradition, ho lived to the age of ninety-four
years, and died and was buried in Crete. The date of the epistle has
101
TOALDO, aiUSEPPE.
TOCQUEVILLE, COUNT DE
102
been a subject of much controversy, some placing it as early as 62,
aud others as late as 65. From the striking verbal resemblances
between it and tho first epistle to Timothy, it is not improbable that
they were written about the same time, and while the same ideas
and phrases were present to the author's mind. The genuineness
and authenticity of the epistle have never been disputed.
St. Paul's design in writing it was to instruct Titus in the discharge
of the duties of his ministry as head of the church in Crete. Accord-
ingly, in chap. L he gives Titus instructions concerning the ordination
of elders, who were to be appointed for every city, and describes
what qualifications they should possess, and also directs him to oppose
the Judaising teachers of Christianity, who seem to have been numerous
in the island. In chap. iL St. Paul informs TituS what precepts he was
to inculcate, according to the age and circumstances of those whom he
had to teach, and admonishes him how to show himself a pattern of all
good works, and an example of the doctrines which he taught. In
chap. iii. he teaches Titus to inculcate obedience to principalities and
powers, in opposition to the Jews, who thought it an indignity to sub-
mit to idolatrous magistrates ; and also that he should enforce gentle-
ness and meekness towards all men. He thien concludes with a request
that Titus would inculcate the necessity of good works, and avoid
foolish questions ; an injunction of the same kind as St. Paul gave to
Timothy.
For the undesigned coincidences between this epistle and the Acts
Home's ' Introduction to the Critical Study of the Scriptures,' vol. iv.,
p. 387; Macknight on the New Testament, vol. iii.; Collyet's 'Sacred
Interpreter.'
TOALDO, GIUSEPPE, a celebrated Italian geographer and meteoro-
logist, was born in 1719 at a small village near Vicenza. After halving
received the usual rudiments of education, he was sent to the Uni-
versity of Padua, in order to qualify himself for the priesthood by
the study of literature and theology ; and while there, a taste for
natural philosophy, and particularly for astronomy, induced hiin to
devote a considerable portion of his time to the pursuit of those
branches of science ; this pursuit he continued, during the intervals
which his pastoral duties afforded, after he had quitted the university
and become the curate of a village in the neighbourhood.
In 1762 he was appointed professor of physical geography and
astronomy in the same university, aud he immediately availed himself
of the influence which his appointment gave him to obtain the grant
of a building which might be occupied as an observatory ; in this he
succeeded, and being allowed the use of an ancient tower, he placed
in it all the instruments which he could collect. In this building he
made a series of astronomical observations, in continuation of those
first thunder-rod erected in the Venetian states was one which Toaldo
applied to the same building.
He died suddenly at Padua, in. December 1798, in consequence of a
fit of apoplexy, which was supposed to have been brought on by a
domestic calamity.
The Abbd Toaldo applied himself to the study of mathematics only
as far as that branch of science is applicable to geography. In 1769
he published at Padua a treatise on plane and spherical trigonometry,
with a collection of tables; and at Venice, in 1773, a tract entitled
' Compendio della Sfera e di Geographia.' In 1782 he published his
'Saggio di Studi Veneti nell' Astronomia e nella Marina;' aud two
years afterwards, his method of finding the longitude of a place by
an observed transit of the moon. In 1789 appeared his ' Trattato di
Gnomonica,' and in 1791 a work entitled ' Schediasmata Astronomica.'
In 1776 he gave, in a letter to Mr. Strange, the British resident at
Venice, an account of the tides in the Adriatic, which he drew from
the. observations of Siguier Temanza, an Italian architect and engineer.
(' Phil. Trans.,' vol. Ixvii.)
The attention of Toaldo was strongly directed tO nieteorology at a
time when this branch of natural philosophy was but little studied ;
and he is the first who took notice of the supposed connection of
atmospherical phenomena with the movement of the moon in her
orbit. . Having observed that those phenomena return in nearly the
same order at the end of eveiy eighteen years, he drew up tables
exhibiting the state of the weather during three such periods; and an
account of his system was given in a paper entitled 'Le Saros M^t^oro-
logique,' &c., which is contained in the ' Journal de Rosier' for 1782.
In 1770 Toaldo published a tract entitled 'Saggio Meteorologico sulla
vera Influenza degli Astri ;' and two years afterwards, a tract concern-
ing the method of protecting buildings from the effects of lightning.
He also published, in 1775, a work on the application of meteorology
to agriculture.
Toaldo wrote a life of the Abb^ Conti, which was prefixed to an
edition of the works of that philosopher and poet, who had been his
instructor.
TOBIN, JOHN. The author of one play which still holds possession
of the stage — a play of considerable merit, although displaying little
of what may be termed original genius — would scarcely be entitled to
notice in a work which does not profess to include the minor adven-
turers in literature, were it not for the peculiar circumstances under
which he devoted a life to dramatic writing. John Tobin was born at
Salisbury in 1770. His father had property in the Islo of Nevis, and
from the political circumstances of the period, thinking his presence
necessary upon his plantation, he took up his residence there, leaving
three sons under the care of their maternal grandfather. They were
placed at the free-school at Southampton, where John discovered some
precocious talents. His father, returning to England, settled at Bristol
in a mercantile employment, where his sons became pupils of the Rev.
Mr. Lee. John, who was the third son, was in 1785 placed in the
house of a London solicitor, in which house he eventually became a
partner. His ambition was however early directed to dramatic com-
position, arid for fifteen years he persevered in offering to the theatres
play after play, each of which was uniformly rejected by the managers.
Tobin had perhaps more real talent than the greater number of those
who had possession of the stage, at a period when a successful
dramatic performance was not only highly paid, according to any
commercial estimate of literary merit, but was very often a little
fortune to its author. But the stage was then also in the hands of
three or four writers, who perfectly understood the taste of the town,
and especially adapted themselves to the peculiarities of the actors
who were to represent their characters. It was a necessary conse-
quence of this system that whilst no drama was composed upon a
principle of aft — whilst no attempt was made to sustain a plot by
consistent and natural character, wit or humour, pathos or poetry —
whilst the author modelled his jokes according to his conception of
this comedian's flexibility of face, and his sentiment with a due
reverence for that tragedian's stride and intonation, — there was still
something produced which was perfect in its way, through the power
of the machinery by which it was worked ; a thing to move laughter
or tears upon the stage, but singularly provocative of sleep in the
closet. This was the day when the drama existed upon slang and
clap-trap, miscalled comedy. Tragedy had died out in its dullness ;
and farce — not legitimate farce — demanded the five acts of Reynolds,
Morton, and George Colman the younger. At this period Tobin
essayed to become a writer of comedy. He produced ' The Faro-
Table,' ' The Undertaker,' and ' The School for Authors :' these were
all rejected. He then tried his hand at the romantic drama, and
wrote, with equal ill success, * The Curfew ' and * The Indians.' The
latter piece was called forth by the success of Sheridan's melo-drama
of ' Pizarro.' Some one, it is said, proposed this question to Tobin at
a social meeting where the state of the drama was a subject of dis-
cussion : " Would a revival of the dramatic spirit which produced the
plays of Shakspere and Fletcher be relished by the public ? " Tobin
thought it would, and he wrote ' The Honeymoon.' This play was
presented to the managers of Covent Garden, and refused. It was
finally accepted at Drury Lane, and it was acted with a success which
has attended very few dramatic compositions. In the meantime its
author, who had a tendency to consumption, was obliged to leave
London, seeking the recovery of his health. He had worked for
many years at his profession by day, and at his dramatic compositions
by night. He died on the 8th of December 1804 ; and ' The Honey-
moon' was produced at Drury Lane on the 81st of January 1805.
Those who cater for the public taste have often an alacrity in dis-
covering the merits of a man when he is dead ; and so Tobin's
rejected pieces were eventually brought upon the stage. They are
forgotten. 'The Honeymoon' is exactly such a piece as might have
been calculated upon, looking at the theory which is said to have
suggested it. It is throughout an imitation of the old dramatists;
clever indeed — but as an automaton compared to a man, for the
breath of poetical life has not been breathed into what moves before
us in the attitudes of humanity. The dialogue is skilful, the chief
situations are interesting, there is a proper quantity of simile and
other embroidery which looks like poetry. But the high art with
which the old dramatists worked is not there. Tobin did the best he
could as an imitator ; but the Shaksperian drama is not a thing for
imitation. The great and essential spirit of poetry is ever the same ;
but it only becomes original as it puts on new forms, the elements of
which are to be found in the aggregate thought of its own age. The
memoirs of John Tobin, with several of his unacted dramas, were
* TOCQUEVILLE, HENRI- ALEXIS, COUNT DE, French states-
man and philosophical historian, was born in 1805, and received a
careful education. In 1831 he went on a government mission to North
America, along with M. Gustavo de Beaumont ; and the fruit of this
visit was his well-known work 'De la Democratic en Am(5rique,' pub-
lished in 1835, in which the political institutions of the United States
were described in a masterly manner, and their bearings philosophi-
cally investigated. The work immediately attracted attention, and
tran.-lations of it were executed in England and America. In 1839,
M, de Tocqueville began active political life as a member of the Cham-
ber of Deputies, and attached himself to the ranks of the opposition.
In the same year a 'Report' on the subject of slavery came from his
pen. But it is since 1848 that M. de Tocqueville has been most heard
of as a politician. He was one of the ministry which Count MoM
proposed to form during the revolution of February, before it had
gone the length of the declaration of the republic. In the early days
of tho republic he figured as a moderate liberal opposed to extreme
views. He wrote and spoke against the Right to Labour and othet
measures of the socialists and vehement republicans. In 1849 he was
elected vice-president of the Assembly, and from June to October he
103
TOD, JAMES.
TODD, REV. HENRY JOHN.
101
was one of the ministers under the presidency of Louis-Napoleon.
His conduct ia relation to tho French expedition to Rome was the
theme of much reprobatiun on the part of the Italian patriots. Since
the coupd'6tat, which made Louis- Napoleon emperor, he has been one
of that band of French constitutionalists and men of letters, who,
" divested of all authority, yet still not unattended by reverence, have
been permitted by the power which has triumphed over them to
record tbeir implied protest against its supremacy, and to found on
their cherished remembrances aspirations for better days." Before the
revolution of 1848 M. do Tocqueville had given to the world bis second
important historical work, entitled ' Histoire philosophique du R&gne
de Louis XV.,' 2 vols., 1847 ; this was followed in 1850 by a sequel
entitled ' Coup-d'ocil sur le R^gne de Louis XVI. depuis son av^nement
jI la Couronne jusqu'Ji la stance royale du 23 Juin 1789;' and since
then M. de Tocqueville has published ' L'Ancien Edgime et la R(Svo-
lution,' 1856. His views of the state of society in France prior to the
great revolution are the result of laborious and minute investigations
into a great variety of materials, and are, in some respects, novel and
peculiar. These views are now accessible to the English reader in
Mr. Henry Reeve's translation, entitled ' On the State of Society in
France before the Revolution of 1789, and on the causes which led to
that event." M. de Tocqueville is still devoting his powers of histo-
rical research and speculation to this great topic. He is a member of
TOD, JAMES, Lieutenant-Colonel in the service of tho East India
Company, was born in England in 1782, but educated in Scotland.
He went out to India in 1800, and obtained a commission in the
2nd Bengal European regiment ; thence he volunteered for the Mo-
luccas, was transferred to the marines, served as a marine on board
the Momington, and in 1805, when in the subsidiary force at Gwalior,
in Hindustan, was attached, under his friend Mr. Graeme Mercer, to the
embassy sent at the close of the Mahratta war to the camp of Sindia in
Mewar, where the embassy arrived in the spring of 1806. Rajpootana,
of which Mewar -is one of the states, thenceforward became the scene
of his official labours, as well as of the geographical, historical," and
antiquarian investigations by which he distinguished himself. He
began to make surveys of Rajpootana soon after his arrival in the
country, and the result of those surveys was the magnificent map
which is given at the commencement of his ' Annals of Rajast'han."
The map was completed in 1815, and was presented to the Marquis of
Hastings, then governor-general of India, and it was of great use in
forming the plan of operations in 1817, tho previous maps of the
country having been very imperfect and erroneous. In 1817 he was
appointed political agent, with the entire control of five of the states
which had just then placed themselves under British protection —
Mewar, Marwar, Jessulmeer, Kotah, and Boondee. The results of
his investigations into the geography, history, and antiquities of
Rajpootana are given in bis ' Annals of Rajast'han.'
In 1822 the impaired state of his health rendered it necessary that
he should return to the more congenial climate of his native country.
Previously however to his departure from India he made a circuit of
nearly the whole of Rajpootana, including Qujerat, which he com-
pleted at the close of 1822, and in the beginning of 1823 he sailed from
Bombay, and arrived safely in England.
After his return to England his time was chiefly devoted to literary
pursuits. He officiated for awhile as librarian to the Royal Asiatic
Society. In 1834 he went to the Continent for the relief of a complaint
in the chest, and remained abroad twelve mouths. He returned to
England in September 1835. While at Rome he was occupied with a
work to be entitled 'Travels in Western India,' the result of the
cially his observations in Gujerat. The last chapters of the work were
written in October 1835, while residing with his mother in Hampshire,
and the manuscript was left nearly fit for publication. On the 16th of
November, while transacting business with his bankers in London, he
had an attack of apoplexy, and lay without consciousness for twenty-
seven hours. He died November 17, 1835, at the age of fifty-three.
He left a widow, the daughter of Dr. Clutterbuck, and a young family.
Bishop Heber, who travelled through Mewar and the adjoining
Rajpoot states in 1825, on his way to Gujerat, bears testimony to the
affection and respect borne to Colonel Tod by the upper and middling
classes of society in various towns through which the bishop passed.
He says — " Here and in our subsequent stages we were continually
asked by the cutwals, &c. after ' Tod Sahib ' (Captain Tod), whether
his health was better since he returned to England, and whether there
was any chance of seeing him again. On being told it was not likely,
they all expressed much regret, saying that the country had never
known quiet till he came among them, and that everybody, whether
rich or pooi-, except thieves and Pindarees, loved him. He, in fact,
Br. Smith told me, loved the people of this country, and understood
their language and manners in a very unusual degree." Bheelwara, a
entirely ruined by the depredations of the Mahrattas at the time when
Colonel Tod was appointed political agent. He set himself to restore
it, and in less than a year there were 700 prosperous and peaceful
families in it. Colonel Tod, in a letter to a friend, say s—" Regarding
Bhilwarra, the work of my hands, in February 1818 there was not a
dog in it; in 1822 I left 3000 houses, of which 1200 were bankers and
merchants. An entire street, arcaded, was built under my directions
and with my means. The merchants from Calcutta, Jessulmdr, Delhi,
Surat, from every mart in India, had their correspondents, and in fact
it was becoming the chief mart of Rajaet'han. The affection of these
people a thousand times repaid my cires." Bishop Heber, after
describing the prosperous state in which he found the town in 1825,
says, " The place had been entirely ruined by Jumsheed Khan, and
deserted by all its inhabitants, when Captain Tod persuaded tho Rana
to adopt measures for encouraging the owners of land to return, and
foreign merchants to settle. He himself drew up a code of regulations
for them, and obtained them an immunity from taxes for a certain
number of years, and sent them patterns of different articles of English
manufacture for their imitation. He also gave money liberally to the
beautifying of their town. In short, as one of the merchants who
called on me said, ' It ought to be called Todgunge, but there is no
need, for we shall never forget him.' "
The 'Annals of Rajast'han' were published in London in 2 vols,
royal 4to, vol. i. in 1829, and voL ii. in 1832. The ' Travels in Western
India, embracing a Visit to the Sacred Mounts of the Jains and the
most celebrated Shrines of Hindu faith between Rajpootana and the
Indus, with an Account of the ancient city of Nehrwalla,' was pub-
lished in 1839 in a handsome 4to volume.
TODD, REV. HENRY JOHN, was bom in 1763, and educated at
Hertford College, Oxford, where he proceeded M.A. in 1786. He
became a minor canon of Canterbury Cathedral soon after being
ordained. In 1792 he was presented by the Dean and Chapter of
Canterbury to the vicarage of Milton, near that city ; and some years
after, by the same body, to the rectory of AUhallows, Lombard-street,
London, on which he fixed his residence in the metropolis. In
November 1803, he was appointed, by the archbishop. Keeper of the
Manuscripts ab Lambeth. In 1820 he was withdrawn from Loudon,
by being presented by the Earl of Bridgewater to the rectory of
Settiington, in Yorkshire, of the value of 1045Z. ; in 1830 he was
collated by the Archbishop of York to the prebend of Husthwaite,
in that cathedral church ; and, finally, in 1832 he was appointed
Archdeacon of Cleveland.
His first publication was 'Some Account of the Deans of Canter-
bury, from the new foundation of the Church by Henry VIII.,' 8vo,
1793. This was followed by an edition of Milton's 'Masque of
Comus,' with notes and illustrations, from a manuscript belonging to
the Duke of Bridgewater, 1798; 'The Poetical Works of John Milton,'
with notes and a life, 6 vols. 8vo, 1801, for which he received 200^.
from the booksellers, and of which there was a second edition in 1809,
a third in 1826, and a fourth in 1843, and the portion of which con-
sisting of the Life and the Verbal Index has also been published
separately ; ' A Catalogue of the Library of Christchurch, Canterbury,'
8vo, 1802 ; ' The Works of Edmund Spenser,' with notes and a Life,
8 vols. 8vo, 1805, reprinted in 1845; 'Illustrations of the Lives and
Writings of John Gower and Geoffrey Chaucer,' 8vo, 1810; 'A Cata-
logue of the Archiepiscopal Manuscripts in the Library at Lambeth
Palace,' fol., 1812 (100 copies privately printed) ; a new edition of
' Dr. Johnson's Dictionary of the English Language, with corrections
and additions,' 4 vols. 4to, 1814, &c., and again in 3 vols. 4to, 1827;
'The History of the College of Bonhommes, at Ashridge,' folio, 1823
(privately printed for the Earl of Bridgewater) ; * Original Sin, Free
Will, Regeneration, Faith, Good Works, and Universal Redemption, as
maintained in certain Declarations of our Reformers,' &c., 8vo, 1S18;
' A Vindication of our Authorised Translation and Translators of the
Bible' (in reference to Bellamy's new translation), 8vo, 1819 ; 'Obser-
vations on the Metrical Version of the Psalms, by Sternhold, Hopkins,
and others,' 8vo, 1819; 'Memoirs of the Life and Writings of the
Right Rev. Brian Walton, Bishop of Chester,' 2 vols. 8vo, 1821 ; 'An
Account of Greek Manuscripts of the late Professor Carlyle, now at
Lambeth,' 8vo, 1823 (privately printed); a new edition of 'Arch-
bishop Cranmer's Defence of the Doctrine of the Sacrament,' Svo,
1825, with a Vindication of Cranmer, reprinted in 12mo in 1826 ; 'A
Letter to the Archbishop of Canterbury, concerning the Authorship
of Icon Basilik^,' 8vo, 1825 (assigning the work to Bishop Gauden) ;
' A Reply to Dr. Lingard's Vindication of his History of England, as
far as respects Archbishop Cranmer,' Svo, 1827 ; ' Bishop Gauden the
Author of Icon Basilik^ further shown, in answer to Dr. Wordsworth,'
Svo, 1829; 'Life of Archbishop Cranmer,' 2 vols. Svo, 1831 (an en-
largement of the ' Vindication ') ; 'Authentic Account of our Autho-
rised Version of the Bible,' 12mo, Malton, 1834. We have omitted a
few theological pieces of inferior importance. He was also, in the
early part of his literary career, a frequent contributor to the ' Gentle-
man's Magazine;' and he is stated, in Hasted's History of Kent, to
have assisted largely in the preparation of that work.
Archdeacon Todd, who was a Chaplain in Ordinary to her Majesty,
died at Settrington, on the 24th of December 1845. From his will,
an abstract of which is given in the ' Gentleman's Magazine ' for June
1846, he appears to have left several daughters.
Archdeacon Todd, though the editor of Milton and Spenser, had no
pretensions to either poetical talent or poetical taste ; nor was even
his acquaintance with our old poetrj', or with our old literature in
general, very extensive or intimate. His annotations, accordingly, are
rather dry. At the same time, if they do not overflow with much
variety of knowledge, and rarely display any remarkable ingenuity.
TODD, ROBERT BENTLEY.
TOLAND, JOHN.
103
they do not annoy the reader by any kind of superfluous disquisition.
He is certainly not a very animated narrator ; but his facts may gene-
rally be depended upon. Hia most useful services, perhaps, have been
rendered in the field of bibliography.
*TODD, ROBERT BENTLEY, M.D., F.R.S., an eminent physician
and physiologist, was born and educated in Ireland. On the opening
of King's College, London, he was appointed Professor of Physiology.
He is a Fellow of the Royal College of Surgeons of Dublin, and a grad-
uate in medicine of the University of Oxford. On settling in London
he became a licentiate and afterwards a fellow of the Royal College
of Physicians. On the opening of King's College Hospital he was
appointed physician to that institution, a post which he holds at the
present day. In 183G, in conjunction with Dr. Grant, he became
editor of the ' Cylopscdia of Anatomy and Physiology,' au extensive
work which is only just completed. Latterly Dr. Todd was the sole
editor, and he has himself contributed several articles, more espe-
cially those on the Heart, Brain, and Nervous System. He has besides
published many works, which have given him a wide reputation as a
practical physician. One of his earliest works was ' On Gout, Rheu-
matic Fever, and Chronic Rheumatism of the Joints.' His clinical
lectures on various subjects have been published in the ' Medical
Gazette ' and 'Medical Times.' Two volumes of these lectures on
diseases of the nervous system and urinary organs were published
in 1857. In conjunction with Mr. Bowman, who was for many years
joint professor of physiology with him in King's College, he published
the ' Physiological Anatomy and Physiology of Man.' He has also
published a work on the ' Anatomy of the Brain, Spinal Cord, and
Ganglions.' In addition to these works he has published many sepai'ate
papers in the * Medico-Chirui'gical Transactions,' and in the medical
journals. He has now resigned his professorship at King's College, and
is enjoying the fruit of his numerous labours in an extensive practice.
*TODLEBEN, FRANCIS EDWARD, Russian General of Engineers,
was born May 25, 1818, at Mitau, in the Russian province of Courland.
He studied at Riga, and was afterwards admitted into the College of
Engineers at St. Petersburg. When the Russian army entered the
Danubian Principalities in 1853 he was 2nd captain in the corps of
engineers, and he served under General Schilders in the campaign on
the Danube. In August 1854 the Russian armies crossed the Pruth
on their retreat from the Principalities, and on the 14th of September
the Fi'ench and English troops were landed in the Crimea. Having
gained the victory of the Alma, the allies made a flank march round
the head of the harbour of Sebastopol, and occupied the heights on
the south side of the city. An elevated ridge with commanding
eminences and deep ravines covered the city and docks ; and the position
was thus eminently defensible, but little had then been done to improve
it by art, for an attack on that side was quite unexpected. Prince
Menschikoff, by sinking some of his great ships at the mouth of the
harbour, having effectually prevented the allied fleet from entering,
the allied armies were at the same time prevented from taking advan-
tage of the undefended state of the city, and carrying it by a sudden
attack ; for they would then have been exposed to the batteries of the
ships in the harbour, far more powerful than any artillery which they
then possessed, and would have risked the loss of their own position
on the southern plateau. A siege was therefore resolved upon; but
no sooner did the allies begin to cut their trenches and prepare for a
bombardment, than earth-works and massive ramparts armed with
formidable batteries began to rise up in opposition with incredible
rapidity. The genius of Todleben seems to have been early discovered,
and the fortifications were placed under his direction. When the city
was ultimately taken, the defences, interior as well as exterior, were
found to be far above as well as different from the works of ordinary
engineering. The extent, completeness, and strength of the Flagstaff,
the Malakhoff, the Redan, and other batteries smaller but connected,
which had so long protracted the siege and rendered the capture so
difficult, filled the spectators with astonishment and admiration.
Todleben was advanced rapidly in the grades of his profession, till at
the termination of the war he had attained the rank of General of
Engineers, and was decorated with the clasps of the order of St.
George. At the latter part of the siege he was wounded in the leg,
but air his great works of defence had then been completed.
TOGRAI, or TOGHRAI, the surname of Abu Ismail Hosein Ben
'Ali Ben Mohammed Mowayyed ed-Din al-Issfahani, and the name by
which he is commonly known. He was descended from Abu'l-Aswad
ad-Doioli, one of the most celebrated of the companions of Mohammed,
and was born at Ispahan in the 5th century of the Hejra, or the
11th of the Christian era, and gained great reputation as a poet. He
was at first in the service of the celebrated Melek Shah (a.h. 465-485 ;
A.D. 1073-92) and his son Mohammed, the third and fifth sultans of
Persia of tho Seljukian dynasty ; and he afterwards became vizir to
Mas'oud, the son of Mohammed, and sultan of Mosul. When this
prince revolted from his brother Mahmud, the seventh Seljukian Sultan
of Persia, and was conquered in the battle at Esterabad near Hama-
dan, A.n. 614 (a.d. 1120), Tograi was taken prisoner, and was at first
kindly treated by the conqueror. This however excited the jealousy
of hia vizir, Abu Talib 'Ali Ben Ahmed as-Semiremi, who caused
Tograi to be secretly put to death, a.h. 515 (a.d. 1121), under the
pretence of his being a heretic who believed the doctrines of the Mola-
heds or Ismaolites, but in reality from fear of hia talents. This is
the acoount of his death given by Abulfeda (' Annal. Moslem.,' vol. iiL,
p. 417) and Ibn Khallekan (« Vit. Illustr. Viror.,' § 196, ed. Wiistenf.);
that given by Leo Africanus (' De Vir. Illustr. Arab.,' cap. 13) ia some-
what different. He was rather more than sixty lunar, or fifty-eight
solar, years old at the time of his death. He appears to have enjoyed
a great reputation, and was distinguished by several titles or surnames.
The word ' Tograi ' is tho name given to the person employed by the
sultan to write on all the imperial decrees and proclamations his name
and titles in a peculiarly large and flourishing character, which is
called, from a Persian work, the * togra ; ' and from Tograi's skill in
writing this, or perhaps from his celebrity as an author, he derived
the title of ' Fakhr al Cottab,' or the Glory of Writers. His surname
' Al-monshi ' signifies a person employed to draw up the letters written
in the name of the prince ; and that of * Alostad ' means the master or
doctor.
The most celebrated of his poems, and the only one which has
been published, is that entitled ' Lamiato 'l-'Ajam,' which he composed
in Arabic at Baghdad, a.h. 505 (a.d. 1111-12). It derives its name
' Lamiat ' from the circumstance that all the verses end with the letter
lam, or I ; and ' al-' Ajam,* that is, ' of the Persians,' is added to dis-
tinguish it from a celebrated Arabic poem written by Shanfara, and
entitled ' Lamiato l-'Arab.' It is a poem of the elegiac kind, written
in a plaintive style, and composed of distichs ; and has been frequently
published and translated. The first edition is that by the elder
Pococke, 8vo, Oxford, 1661, with a Latin translation, and copiou.s
elementary note?. At the end of the volume is a treatise on Arabic
prosody by Samuel Clerk, the University printer. - There is an edition
by Matthias Ancherseji, with an unedited Latin translation by Golius,
published in 1707, Utrecht, which is now exceedingly scarce, as almost
all the copies were lost at sea. Tograi's poem was also published in
Arabic, together with that by Shanfara, by H. A. Friihn, 8vo, Casan,
1814. It was translated into English by Leon Chappilow, 4to, Cam-
bridge, 1758 ; into French by Pierre Vattier, 8vo, Paris, 16G0 ; into
German by Reiske, Friedrichstadt, 4to, (Dresden), 1756. A fuller
account of the editions and translations of this poem may be found in
Schnurrer's 'Bibliotheca Arabica,' and Zenker's 'Bibliotheca Orien-
talis,' 8vo, Leipzig, 1840. Tograi also wrote a work on alchemy,
entitled ' Directio in Usum Filiorum,' which title has been the occasion
of D'Herbelot's making a great mistake as to the contents of the book.
(Schnurrer, Bihlioth. Arab. ; De Sacy's article on Tograi in the
Biograph. Univers. ; Wiistenfeld, Gesckichte der Ardbischen Aei'zte und
Naturforscher, Gottingen, 1840, § 151, p. 87.)
TOLAND, JOHN, was born on the 30th of November 1669 or
1670 (it is not certain which), in the most northern part of the county
of Londonderry, in the peninsula called Inis-Eogan, whence in one of
his works, published with a Latin title, he called himself ' Eoganesius.*
Though it is not known who his parents were, it is known that they
were Roman Catholics. He tells us of himself, " Being educated from
to make my own reason, and such as made use of theirs, the happy
instruments of my conversion." (' Christianity not Mysterious,' Pre-
face, p. viii.) And again, alluding, in his ' Apology ' (p. 16), to a
charge made against him that he was a Jesuit, he says that " he was
not sixteen years old, when he became as zealous against Popery as he
has ever since continued. . . . Yet in Ireland that malicious report
gained upon some few, because his relations were Papists, and that he
happened to be so brought up himself in his childhood." He was sent
first to a school at Redcastle near Londonderry, where, we are told,
that, having been christened Janus Junius, he was laughed out of this
name by the boys, and took the name of John, which he ever after
kept. He went in 1687 to the University of Glasgow, and after being
there three years, to the University of Edinburgh, where he got a
diploma as Master of Arts, in June 1690. Shortly after this he went
into England, where managing to gain the favour of some influential
dissenters, he was sent by them to the University of Leyden to study,
and prepare himself for the duties of a minister.
He stayed at Leyden about two years, and made the friendship of
Le Clerc, Leibnitz, and other learned men, with whom he afterwards
corresponded. On his retui'n to England he went for some time to
Oxford, where he employed himself chiefly in collecting materials on
various subjects in the Bodleian library. The vanity of his character,
and the ostentatious avowal of free-thinking on religion, appear to
have made him conspicuoiis at Oxford, as they did everywhere else
through the whole of his life. But in a reply to a letter of advice
which he received here, he denied his being either an atheist or a deist.
(' Collections of Several Pieces of Mr. John Toland, &c.,' vol. ii. p. 302.)
At Oxford he began his ' Christianity not Mysterious,' which was
published in London in 1696, the year after his leaving Oxford. The
remainder of the title, viz., ' A Treatise showing that there is nothing
in the Gospel contrary to reason nor above it, and that no Christian
doctrine can be called a Mystery,' more fully explained the object of
the publication. The work created a very considerable sensation, and
elicited much attack and some persecution.
In 1697 Toland returned to his native country. Mr. Molyneux
wrote to Locke, April 6th, 1697, from Dublin: "In my last to you,
there was a passage relating to the author of * Christianity not Myste-
rious.' I did not then think that he was so near me as within the
bounds of this city •, but I find since that he is come over hither, and
107
TOLAND, JOHN.
TOLAND, JOHN.
108
have had tho favour of a visit from him. I now understand, as I
intimated to you, that he was bom in this country, but tbat he hath
been a great while abroad, and bis education was for some time under
the great Le Clerc. But that for which I can never honour him too
much is his acquaintance and friendship to you, and the respect which
on all occasions he expresses for you. I propose a great deal of satis-
faction in his conversation — I take him to be a candid free-thiuker,
and a good scholat. But there is a violent sort of spirit that reigns
here, which begins already to show itself against him, and I believe
will increase daily ; for I find the clergy alarmed to a mighty degree
against him; and last Sunday he had his welcohie to this city,
in hearing himself harangued against out of the pulpit by a
prelate of this county." (Locke's 'Works,' vol. viil. p. 405, 8vo,
ed. 1 799.) Toland appears to have become acquainted with Locke ;
and this acquaintance he made tho most of in conversation at Dublin.
In Locke's reply to the Bishop of Worcestei-, who, in defending the
doctrine of the Trinity against Toland, had connected Locke with
him, he showed that he did not reciprocate in an equal degree Toland's
friendship and esteem for him. Mr. Molyneux wrote tif him after-
wards, May 27, 1697 : " Trhly, to be free, I do not think his manage-
ment, since he came into this city, has been so prudent. He has raised
against him the clamour 6f all parties, and this not so iliuch by his
dilitrence in opinion, as by his unreasonable way of discoursing, pro-
pagating, and maintaining it. . . . Mr. Toland also takes here a
great liberty on all occasions, tti vouch yoar patronage and friendship,
which makes many that rail at him rail also at you, I believe you will
not approve of this, as far, as I am able to judge, by your shaking him
off, in your letter to the Bishop of Worcester" (p. 421). And Locke,
on June 15, wrote what is worth quoting for itself, as well as for the
opinion implied of Toland : "As to the gentleman to whom you think
hereafter, I must tell you that he is a man to whom I never wrote in
toy life, and I think I shall not now begin ; and as to his conduct, it is
what I never so much as Spoke to him of : that is a liberty to be taken
only with friends and intimates, for whose conduct one is mightily
concerned, and in whose affairs one interests himself. I cannot but
wish well to all men of parts and learning, and be ready to afford
thein all the civilities and good offices in my power; but there must
be other qualities to bring me to a friendship, and unite me in those
stricter ties of concern ; for I put a great deal of difference between
those whom I thus receive into my heart and affection and those
whom I receive into my chamber, and do not treat them with a
perfect strangeness " (p. 425). Pecuniary difficulties and persecu-
tions together obliged Toland to leave Ireland in a very short time.
The parliament at Dublin voted that the book should be burnt by the
common hangman. Mr, Molyneux gives an account of his departure
in another letter written to Locke.
Ho went to London, and, nothing daunted, published 'An Apology
for Mn Toland, in a Letter from himself to a Member of the House
of Commons in Ireland, written the day before his book was resolved
to be burnt by the Committee of Religion : to which is prefixed a
Narrative containing the occasion of the said Letter.' He now
devoted himself very vigorously to book-making of all sorts, in politics,
theology, literature : showing alwiiys, even in the pamphlets which
the mere passing occasions called forth, a degree of genius and erudi-
tion deserving of a better fate than his Very scanty and precarious
earnings. He published in 1698 a pamphlet, just after the Peace of
Ryswick, when there arose the question what forces should be kept
on foot, entitled, ' The Militia Reformed, or an easy scheme of fur-
nishing England with a constant Land Force, capable to prevent or
to subdue any foreign power, and to maintain perpetual quiet at
home, without endangering the public liberty ; ' and in the same year
his ' Life of Milton,' which Was prefixed to ' Milton's Prose Works,'
in 3 vols, folio. Then came, in 1699, the ' Amyntor, or a Defence of
Milton's Life,' in answer to a criticism of Dr. Blackall, bishop of
Exeter, on some incidental remarks made by him in his ' Life of
Milton' on the genuineness of some parts of Scripture, There
followed in rapid succession his editions of Holles's * Memoirs,' and of
Harrington's Works, with a life of Harrington prefixed ; ' Clito,' a
poem on the force of eloquence ; ' Anglia Libera, ot the Limitation
tod Succession of the Crown of England explained and asserted,* and
other political pamphlets. The 'Anglia Libera' was published in
1701, on the passing of the act which settled the crown on the Princess
Sophia of Hanover and her heirs, after the death of William, and of
Anne without issue ; and Toland Went over to Hanover and managed
to get presented to the electress by the Earl of Macclesfield, who liad
been sent on a special mission to carry the act to the electress, and then
Jjreseuted his 'Anglia Libera' to her with his o'si-n hands. He after-
wards stayed in HaUover for some short time, and went from thence
to the court of Berlin, acting at these courts apparently as a sort of
political agent, and making the most of the recommendations which
he carried from the EngLsh government to extend his reputation for
literature and learning. He won the good opinion both of the Princess
Sophia and of the Queen of Prussia; they both courted his conversa-
tion, and afterwards his correspondence. On the occasion of his first
visit to Berlin he held a theological discussion with Beausobre in the
presence of the queeti, who acted as a sort of moderator, and closed
it, on observing that the disputants were beginning to lo30 their
temper. His letters to Serena, published in 1704, were addressed to
the queen of Prussia.
In 1702, in an interval of his residence abroad, he published
' Vindicus Liberius, or Mr. Toland's Defence of himself against the
Lower House of Convocation and others.' In this work his opinions
have assumed a very subdued tone, which is perhaps to be accounted
for in a great measure by the prospect of political advancement which
seemed to be opening for him. " Being now arrived to years that will
not wholly excuse inconsiderateness in resolving, or precipitance in
acting, I firmly hope that my persuasion and practise will show me to
be a true Christian, that my due conformity to tho public worship
may prove me to bo a good churchman, and that my untainted loyalty
to King William will argue me to be a staunch commonwealth's man."
Subsequent theological works showed this to have been a moderation
merely assumed for the time.
The mask of orthodoxy was thrown off in a pamphlet which he
published in 1705, in the title of which he did not scruple to dfesi;^nate
himself a Pantheist : ' Socinianism truly stated, being an example of
fair dealing in theological controversies ; to which is preBxed Indif-
ference in disputes recommended by a Pantheist to an orthodox friend.'
But he was now enjoying the zealous patronage of Harley, afterwards
earl of Oxford, who had in the previous year become secretary of state,
and he probably thought he could again afford to be a freethinker,
Harley employed him to write several political pamphlets, and sent
him abroad again in 1707, to Germany and Holland. The nature of
his connection with Harley may be gathered from the foUovdng extract
from one of his ' Memorials to the Earl of Oxford,' which are printed
in a posthumous collection of his pieces written at a time when the
zeal of his patron had cooled : — " I laid an honester scheme of serving
my country, your lordship, and myself; for seeing it was neither con-
venient for you nor a thing at all desired by me, that I should appear
in any public post, I sincerely proposed, as occasions should offer, to
communicate to your lordship my observations on the temper of the
ministry, the dispositions of the people, the condition of our enemies
or allies abroad, and what I might think most expedient in every con-
juncture ; which advice you were to follow in whole, or in part, or
not at all, as your own superior wisdom should direct. ... As
much as I thought myself fit, or was thought so by others, for such
general observations, so much have I ever abhorred, my lord, those
particular observers we call spies ; but I despise the calumny no less
than I detest the thing." (vol, ii, p, 223.) Toland was abroad on this
occasion for about three years, acting as a sort of political spy for
Harley, though he disavowed the name, and eking out his subsistence
by his pen, and apparently in any way that presented itself He mado
a trip from Holland to Vienna, commissioned by a wealthy banker to
procure for him from the imperial ministers the rank of a count of
the empire ; but he did not succeed in attaining the object of his
mission. He managed in Holland to ingratiate himself with Prince
Eugene, who was very .attentive and liberal to him. In the ' Memo-
rial' to the Earl of Oxford, which has been before quoted, Toland
mysteriously connects tliis prince with his mission to Vienna, and
cunningly tries to give this foolish journey a character of great dignity
and honour. " My impenetrable negociation at Vienna, hid under the
pretence of curiosity, was not only applauded by the prince that
employed me, but also proportiouably rewarded " (p. 225). In due
time he quarrelled with Harley, and then wrote pamphlets against
him, Asa Whig pamphleteer, he had the honour of Swift's notice in
' Toland's Letter to Dismal.'
The principal publications of Toland which remain to be mentioned
are the following, with the dates of their appearance : — a volume pxib-
lished at the Hague in 1709, containing two Latin essays, with the titles
'Adeisida?raon, sue Titus Livius, h, Superstitione Vindicatus,' and
' Origines Judaicfo, seu Strabonis de Moyse et Rehgione Judiaca His-
toria brevitJsr illustrata ; ' ' The Art of Restoring, or the Piety and
Probity of General Monk in bringing about the last Restoration, evi-
denced from his own Authentic Letters, with a just account of Sir
Roger, who runs the parallel as far as he can' (by Sir Roger was
meant the Earl of Oxford, his former patron, who was then plotting
the restoration of the Pretender) ; and * A Collection of Letters by
General Monk, relating to the Restoration of the Royal Family,' both
published in 1714: 'Reasons for Naturalising the Jews in Great
Britain and Ireland, on the same footing with all other nations, with a
Defence of the Jews against all Vulgar Prejudices in all Countries,'
published in 1714 ; 'The State Anatomy of Great Britain, containing
a particular account of its several Interests and Parties, their bent
and genius, and what each of them, with all the rest of Europe, may
hope or fear from the reign and family of King George,' which work
called forth several answers, that led Toland to publish a second part;
' Nazarenus, or Jewish Gentile, or Mahometan Christianity, containing
the History of the Antient Gospel of Barnabas, and the Modern
Gospel of the Mahometans, attributed to the same Apostle, this last
gospel being now first made known among Christians: also the
original plan of Christianity, occasionally explained in the Nazarenes,
institution may be happily terminated ; with the relation of an Irish
manuscript of the four gospels, as likewise a summary of the antient
Irish Christianity, and the reality of the Keldees (an order of lay
religious), against the two last bishops of Worcester,' which appeared
109
TOLEDO, DON PEDRO DE.
TOLEDO, DON PEDRO DE.
110
in 1718; ' Pantheisticon, sive Formula celebrandaj Sodalitatis Socra-
ticao, iu tres partes divisa, quao Pantheistarum eive sodalium continent,
1, Mores et axiomata; 2, Nutnen et philosophiam ; 3, Libertatcm et
non fallenfcem legem neque fallendam : Praemittitur de antiquis et
novis eruditorum sodalifcatibus, ut et de universo infinito et ajterno,
diatriba. Subjicitur de duplici Pantheistarum philosophia sequenda, ac
de viri optimi et ornatissimi idea, disseitatiuricula,' published in 1720;
and in the same year, ' Tetradymus ; ' and in 1721, ' Letters from the
Right Honourable the late Earl of Shaftesbury to Robert Molesvvorth,
Esq., now Lord Viscount of that name ; with two letters written by
the late Sir John Cropley,'
Some of these titles show at once the learning and the fantastical
pedantry of Toland. The ' Tetradymus ' consists of four treatises,
which bear the names Hodegus, Clydophorus, Hypatia, and llango-
neutes, and have for their respective subjects the pillar of cloud and
fire which led the Israelites, and which Toland argues was no miracle ;
the exoteric and esoteric philosophy of the ancients ; an account of the
female philosopher Hypatia, " who was murdered at Alexandria, as
was supposed, at the instigation of the clergy ; " and an answer to Dr.
Mangey, who had attacked his 'Nazaronus.' The 'Nazarenus' and the
'Pantheisticon' had again evoked the anger of the church. Dr. Hare,
dean of Worcestei-, in a treatise against Hoadley, spoke of Toland as
often quoting Locke to support notions he never dreamed of. Toland
even named Locke in his writings. Hare issued a counter-advertise-
ment, in which he directs " makes great use of Mr. Locke's principles"
to be read instead of " is often quoted to support notions he never
dreamed of" Toland then published a pamphlet, with the title ' A
Short Essay upon Lying, or a Defence of a Reverend Dignitary, who
suffers under the Persecution of Mr. Toland, for a lapsus calami.' This
' Tetradymus.' Hare returned to the charge, and, in the preface to a
new edition of his work, speaks of "downright Atheists," such as the
impious author of the * Pantheisticon.'
Towards the close of his life, Toland, whom all his literary industry
could not keep from pecuniary difficulties, found a benefactor in Lord
Molesv/orth. Mr. Disraeli, who has devoted a chapter to Toland in his
' Calamities of Authors,' mentions from Toland's papers which he has
seen, the paltry sums which he generally I'eceived for his writings.
" For his description of Epsom he was to receive only four guineas in
case 1000 were sold. He received ten guineas for his pamphlet on
Naturalising the Jews, and ten guineas more in case Bernard Lintott
sold 2000." And in another place, in the ' Quarrels of Authors,' in
the chapter headed 'Lintott's Account-Book,' he says, "It appears that
Toland never got above 51., 101., or 20^. for his publications. . . .
All this author seems to have reaped from a life devoted to literary
enterprise, and philosophy, and patriotism, appears not to have
exceeded 200Z." This last statement must be a great exaggeration.
Further details as to Toland's literary gains, derived also from Lin-
tott's Account-Book, are to be found in Nichols's * Literary Anecdotes,'
vol. v., p. 302.
Toland died at Putney, where he had lodged for about four years
previous, choosing that place on account of its convenient distance
from London, on the 11th of March 1722. " Never," says Mr. Disraeli,
" has author died more in character than Toland : he may be said to
have died with a busy pen in his hand. Having suffered from an
unskilful physician, he avenged himself in his own way ; for there was
found on his table an 'Essay on Physic without Physicians.' The
dying patriot trader was also writing a preface for a political pamphlet
on the danger of mercenary parliaments ; and the philosopher was
composing his own epitaph, one more proof of the ruling passion pre-
dominating in death ; but why should a Pantheist be solicitous
to perpetuate his genius and his fame ?"
Toland's posthumous works were published in 1726, in 2 vols. 8vo,
with a Life by Des Maizeaux prefixed, and were republished in 1747.
The contents of these two volumes are an additional proof of the ver-
satility of his powers : they contain, together with many other essays,
the Memorials to the Earl of Oxford which have been referred to, and
several private letters : an account of Giordano Bruno ; the Secret
History of the South-Sea Scheme, in which Toland had been con-
cerned; a Plan for a National Bank; and a proposal, in Latin, for a
new complete edition of Cicero. * An Historical Account of the Life
and Writings of the late eminently famous Mr. John Toland, by one
of his most intimate friends, in a letter to the Lord ■ ,' was pub-
lished in 1722; and is attributed to Curll. This is not so minute a
biography as Des Maizeaux's and is rather a sketch of his writings and
opinions. There is appended to it a complete list of Toland's works,
Toland's works have never been collected, and the notoriety which
attended him during his life having soon died away, they are now
little known. But they are almost all of some worth, and his political
writings may throw some little light on the history of the times.
TOLE'DO, DON PEDRO DE, a younger son of Frederic of Toledo,
duke of Alba, was born at Alba de Tormes, near Salamanca, in 1484.
After going through his early studies he was placed as a page in the
court of King Ferdinand the Catholic, who took him into particular
favour; and it was by the king's influence that young Pedro obtained
the hand of Donna Maria Osorio, heiress of the house of Villafranca,
in consequence of which he took the titlo of Marquis of Villafranca,
and the possession of the rich estates attached to it. He afterwards
served with distinction in the expedition against Jean d'Albret, king
of Navarre, and after King Ferdinand's death he continued in the
service of his successor Charles I. of Spain, afterwards Charles V. of
Qermany. He served against the revolted communeros of Castile,
and afterwards followed the court of Charles V., whom he accompanied
in his journeys through Flanders, Qermany, and Italy. In 1532,
being at Ratisbo^ with the emperor, the news arrived of the death of
Cardinal Colonna, viceroy of Naples, when Charles V. appointed for
his successor Don Pedro de Toledo, marquis of Villafranca, who
immediately set ojit to take possession of his government. He found
the kingdom suffering from the consequences of the preceding foreign
and civil wars, and especially of the recent French invasion of 1527-29,
and the revolt of many of the barons and the subsequent conQscation
of their property; of the plague, which, originating in the French
camp, had desolated the city of Naples; and the state of confusion,
bordering upon anarchy, which prevailed in the provinces. The first
care of the new viceroy was to enforce the rigorous administration of
justice without respect for persons, and he sent to the scaffold the
commendator Pignatelli, the count of Policastro, and other noblemen,
who had been guilty of oppression and other crirpes. He pulled
down the old dark arcades and other places which were the resort of
thieves and murderers ; he abolished the abuse of making the palaces
of the barons a place of asylum for criminals ; forbade the use of
weapons, except the side sword, then worn by gentlemen; he sen-
tenced duellists to death, prescribed regulations for restraining the
disorders that took place at funerals and paarriages; and, lastly, by a
' bando,' or public edict, he inflicted the penalty of death on any one
found in the night with ladders scaling the windows of houses, a
practice which had become frequent among dissolute men, who thus
introduced themselves into ladies' apartments. Don Pedro reformed
the courts of justice, increased the number of judges, and made
several regulations for the more humane treatment of prisoners and
debtors; and also for the prevention of bribery and perjury. He
raised an extensive building near Porta Capuana, where he placed all
the higher courts of justice, civil and criminal.
When Charles V., on his return from the Tunis expedition in 1535,
visited Naples, where he remained till March, 1636, amidst the
festivals and rejoicings with which he was greeted, he received hints
and suggestions from several of the nobility against Toledo, but
Charles stood firm in his good opinion of the viceroy, especially after
having heard the deputies of the people, who explained to him that
the nobility disliked Don Pedro because he would not permit them to
oppress the lower orders, and to put themselves above the law, as
they had been wont to do. It is reported that Charles, when he
lauded at Naples, on meeting the viceroy, said to him, " Welcome,
marquis ; I find that you are not become so large as I was told you
were;" to which Toledo replied, smiling, "Sire, I am aware that you
have been told that I was grown a monster, which I am not."
Toledo greatly embellished Naples ; he enlarged the city, extended
the walls, cleared, widened, and paved the streets, and made new
drains and sewers; he built the royal palace near Castel Nuovo,
which is now called ' Palazzo Vecchio,' and constructed the handsome
street which still bears his name. He adorned the city with fountains,
enlarged the dockyard, fortified the castle of S. Elmo, built new
hospitals and churches, and, in short, he quite altered the appearance
of Naples, He also drained the marshes by opening the wide canal
called dei Lagni, which carries the superfluous waters into the sea.
In 1537, the Turks having landed at Castro and other places of the
province of Otranto, Toledo summoned the barons with their militia,
and marched with them and the regular Spanish troops against the
enemy, who, finding the country prepared for defence, took again to
their ships and sailed away. Toledo fortified the maritime towns of
Apulia, built towers of defence along the coast, restored Pozzuoli,
which was nearly depopulated in consequence of the earthquakes and
volcanic eruptions, and enlarged the ' Qrotta,' which leads to it from
Naples. For all these and other services to the Neapolitans, as well as
for the just though severe tenor of his general administration, Don
Pedro de Toledo had become very popular, until the year 1547, when
his ill-judged attempt to establish the tribunal of the Inquisition after
the fashion of his own country, Spain, rendered him nniversally
obnoxious. The cause of this attempt was that the doctrines of the
even among priests and monks. Charles V., who was at that time
struggling in Germany with the religions and political dissensions
arising out of the Reformation, dreaded a similar explosion in his
Italian dominions, and the viceroy Toledo wished to save his master
the additional trouble. Pope Paul III. was anxious to assist them in
repressing the spread of heresy to Italy : but the Neapolitans, a lively,
communicative people, had conceived a great horror of that gloomy
and arbitrary court and its secret proceedings; they had heard of its
deeds in Spain, and they determined to resist its introduction into
their country, even by force of arms if necessary. The tumult began
about the middle of May, when the people tore down the placards
containing the edict which sanctioned the establishment of the Inqui-
sition, from the gates of the archbishop's palace. A cry of " To arms ! "
resounded through the streets and squares ; most of the nobles, who
Ill
TOLETANUS, RODERICUS.
TOLLENS, HENDRIK CORNELISZOON.
112
bated Toledo for their own reasons, joined the citizens in their
resistance. The people turned out some of their municipal magis-
trates whom they Buapect«d of being for the viceroy, and elected
others without the viceroy's sanction; and Toledo having resented
this proceeding, the people took up arms, and attacked the Spanish
soldiers who garrisoned the castles. The Spaniards fired with cannon
into the city, and the people cut down all Spaniards whom they found
straggling. The viceroy, having seized some of the head rioters,
caused them to be summarily executed, which added fuel to the
flame, and the citizens and nobles formed themselves into a union or
patriotic convention, taking for their motto, " For the service of God,
the emperor, and the city of Naples ; " stigmatising as traitoi's to
their country tho.»e who did not join the union. The.^ union sent as
envoys to Charles V. the prince Sanseverino and another nobleman,
refusing meantime obedience to the viceroy, who remained in the
castle with his Spanish soldiers and a few Neapolitan adherents, and
the town was without any regular government. Frequent skirmishes
took place in the streets between the viceroy's men and the people ;
many individuals were killed, and houses were plundered. At last
the answer came from Charles V., commanding the citizens to lay
down their arms, with secret instructions to the viceroy to proceed
leniently and prudently in the matter.
On the 12th of August Toledo signified to the deputies of the city
the will of the emperor that the Inquisition should not be established
in Naples ; that the past should be forgotten, except as to some of the
principal leaders of the insurrection, who were obliged to emigrate ;
and that the city should pay one hundred thousand crowns as a fine.
And thus this serious affair was hushed up, but the Neapolitans
gained their point, and the tribunal of the Inquisition was never
established at Naples, though persons accused of heresy were tried by
the common ecclesiastical court, and several of them were put to
death by the concurrence of the lay power. The prince Sanseverino,
France, and was outlawed. [Tasso, Beknardo.]
In July, 1552, a large Turkish fleet, under Dragut Rais and Sinan
Pasha, anchored near Procida, at the entrance of the Bay of Naples,
■when the emigrant prince Sanseverino of Salerno was to have joined
them with a Fi'ench squadron ; but the viceroy, it is said, by means
of a large bribe, induced the "Turkish commanders to leave the coast
before the arrival of the French.
Toward the end of the same year the viceroy, although old and
infirm, was desired by Charles V. to march to Siona in Tuscany,
which republic had thrown oQ' the protection of the emperor and
admitted a French garrison. Don Pedro having sent most of the
troops by land, embarked with the rest for Leghorn. On arriving
there he fell seriously ill, and was removed to Florence. The duke
Cosmo de Medici had married his daughter Eleonora. He expired at
Florence, in February, 1553, after having administered the kingdom of
Naples for more than twenty years. He is by far the most dis-
tinguished in the long list of the Spanish governors of Naples, and
one of the few who are still remembered with feelings of respect by
the Neapolitans.
(Giannone, Storia Civile del Regno di Napoli; Botta, Storia d! Italia.)
TOLETA'NUS, RODERl'CUS, or RODRI'GO DE TOLE'DO, an
eminent ecclesiastic and historian, was born at Kada, in Navarre,
about 1170. His name was Rodrigo Simonis, commonly Ximeuez;
but he is better known as Rodericus Tolefcanus. On his return
from Paris, where his parents sent him to complete his education,
he attached himself to Sancho V., king of Navarre, by whom he
was employed to negociate a peace with Alfonso VIII. of Castile.
The manner in which he discharged this mission procured him the
favour of Alfonso, by whom, in 1192, he was appointed bishop of
Siguenza, and on the death of Don Martin, archbishop of Toledo, he
was raised to the vacant see. He showed great zeal in the frequent
wars with the Moora, and at the battle of Las Navas, where the
Almohades, under Mohammed Annilsir, were defeated by Alfonso, his
pennon was the first that entered the dense ranks of the enemy.
Indeed such were his courage and martial disposition, that even when
the king was at peace with the Moors, he would, at the head of his
ow.n vassals, make frequent inroads into the Mohammedan territory.
He enjoyed so much favour with the kings of his time, especially
with San Fernando, that nothing was undertaken without consulting
him. His zeal for learning was no less ardent than his hatred of the
infidel. He persuaded Alfonso to found the university of Palencia,
and thereby avoid the necessity of sending youths to be educated in
foreign countries. At the fourth Lateran council he is said not only
to have harangued the fathers in elegant Latin, but to have gained
over the secular nobles and ambassadors by conversing with each of
them in his mother tongue. He died in France, in 1247, after attend-
ing the council of Lyon, convoked by Innocent IV. His body was
carried to Castile, and interred in the Cistercian monastery of Huerta.
To him the history of his native country is more indebted than to
any other man. He wrote several historical works, most of which are
still inedited. His * Rerum in Hispania Gestarum Ohronicon,' which
contains a history of the Peninsula from the most remote period to his
own time, is an invaluable production. It was printed for the first
time at Granada, in 1545, together with tho chronicle of Antouius
Nebrissenbis, and was subsequently published in the collection entitled
'Hispania lUustrata,' by Andreas Schott, 4 vols, fol., Frankfurt,
1603-8. His ' Historia Arabum,' or history of the western Arabs from
the birth of the Mohammedan prophet to the invasion of Spain by
the Almoravides, shows him to have been well versed in the language
and history of the Arabs. This valuable work was firt^t published, in
1603, in the second volume of Andreas Schott, ' Hispania lUustrata,'
and subsequently, in 1625, by Erpennius, as an appendix to his ' His-
toria Sarracenica ' of Georgius El macin. There is a third edition. He
also wrote a history of the Ostro-Goths, another of the Huns, Vandals,
in the collection entitled ' Rerum Hispanicarum Scriptores aliquot,'
3 vols, fol., Frankfurt, 1579, and subsequently by Schott ; a history
of the Old and New Testament, entitled ' Breviarium Ecclesiae Catho-
lic£o,' still inedited, and other works, the list of which may be seen in
Nicolas Antonio.
(Mariana, Hist. Gen. de JSspaiia, lib. ii., cap. 22; Zurita, Annales de
Aragon, lib. ii., cap. 67 ; Nicolas Antonio, Bibl. Hist. Vetus, ii. 50.)
TOLLENS, HENDRIK CORNELISZOON, long the most popular
living poet of Holland, was born at Rotterdam on the 24th of Sep-
tember 1780. His father carried on a thriving business, founded by
his grandfather, as a dealer in colours, and Hendrik was taken from
school at the age of fourteen to assist behind the counter. The year
after was that of the French entry into Holland, when many of the
Dutch were disposed to look on them as deliverers, and young ToUens
became the secretary of a " Vaderlandsche Bijeenkomst," or Patriotic
Society, to whose purposes he soon contributed some songs, which
son's reputation, soon grew alarmed that poetry would lead him away
from business, though that alarm might surely have been spared in
Holland. When Tollens, at the age of seventeen, made the acquaint-
ance of two poets," one of them, Helmers [Helmers], was a merchant,
the other-, Loots, a book-keeper in a counting-house, and Uylenbroek,
a third, to whom they introduced him, a respectable bookseller.
now studied English and German, and thus enlarged his ideas ; but he
followed Uylenbroek's example in occupying himself with rendering
French tragedies into Dutch verse. He afterwards ventured on
original dramas, and his ' Lucretia,' written in 1805, had, at all events,
sufficient spirit to be prohibited by the government. Another tragedy,
' De Hoekschen en Kabeljaauwschen ' (The Hooks and the Codfish),
had at least the merit of a national subject, being founded on the
quarrels of the rival factions of these names, the Guelphs and Ghibel-
ines of Dutch mediajval history, whose hostilities, which lasted a
century and a half, are said to have arisen in 1350 from a jocose dis-
pute between some nobles at a banquet as to whether the codfish
could be said to take the hook, or the hook the codfish. ToUens's
powers however did not lie in tragedy. In two contests with his
friend Loots on subjects offered for prizes, one on the theme Hugo
Qrotius, and the other the death of Egmont and Hoorn, he won the
second prize on the first occasion, and the first on the second ; and in
1807 a short poem by him ' To a Fallen Girl,' attracted attention by
its simple pathos. From that time his subjects were almost univer-
sally taken from national history and from domestic scenes, and
though even his admirers did not place him on a level in point of
genius with Bilderdijk, he became decidedly the most popular poet
of his country, and had the honour of forming a school of poets — " the
school of Rotterdam." In 1817 the third edition of his poems had
10,000 subscribers; not long afterwards his fellow-townsmen pro-
posed to erect his bust in a public place, and it was only the reluct-
ance of Tollens himself which prevented the intention from being
carried out when the subscription was already full. This popularity
increased as he grew more advanced in life. On his seventieth birth-
day, the 24th of September 1850, the minister of justice Mr. Neder-
meijer van Rosenthal waited on him at his house at Rijswijk to bring
him the congratulations of the King of Holland, and present to him
the insignia of commander of the order of the Dutch Lion, a very
unusual honour for a literary man. A committee waited on him the
same day to ofier him a gold medal struck in his honour, with the
inscription "Nederland zijnen geliefdeu Volksdichter ' (Netherland to
its beloved national poet), and to inform him that a subscription had
been organised, without his knowledge, for the formation of a ' Tollens
Fund,' to commemorate his name by a charitable institution, the
nature of which was to be left to his own choice. He died in 1856,
surrounded by universal respect.
The shorter poems of Tollens, lyrical and narrative, are his chief
title to remembrance. One narrative poem, 'De Overwintering der
Hollanders op Nova Zembla ' (The Wintering of the Hollanders at
Nova Zembla), commemorative of the celebrated voyage of Barends in
1596-97, is very popular and has often been reprinted, on one occa-
sion in an illustrated edition. His ' Vierdaagsche Zeeslag,' or Four
Days' Sea-Fight, commemorative of one of the desperate contests
between the Dutch and English in the reign of Charles II., may be
compared for spirit to his friend Loots's ' Overwinning bij Chattam '
(Victory at Chatham), a favourite bubject of allusion with the Dutch
poets. Tollens is a fertile author of ballads on subjects of Dutch his-
tory, among which his ' Jan Van Schafl'elaar,' ' Keuau Hasselaar,' &c.,
are conspicuous. His ' Wapenkreet ' (Call to Arms), written on occasion
of Napoleon's return from Elba, is one of his best productions.
113
TOLLIUS, CORNELIUS.
TOMLINE, GEORGE.
114
ToUens translated much from the Qerman and English as well as the
French, but often adapted the pieces he borrowed to Dutch subjects
that his 'Jonker van 't Sticht' was taken from Scott's 'Young
Lochinvar,' which has also beou done into Dutch by Van Lennep,
under the title of * Do Heer van Culemborg.' Tollens's works, of
which a new edition is now publishing, are of some extent ; his shorter
poems alone occupy about ten 8vo volumes, not very closely printed.
TO'LLIUS, CORNE'LIUS, a Dutch philologer, was born at Utrecht
about 1620. His father, who had two other sons, Jacob and Alex-
ander, possessed no means of giving his children a good education,
but he had in G. J. Vossius a friend who gratuitously supplied the
want. After Cornelius had for some years enjojed the private
instructions of Vossius, he entered the academy of Amsterdam, and
continued his philological studies under the auspices of his bene-
factor, who bad formed a strong attachment to him, and made him
his private secretary (famulus). In 164S Tollius obtained the pro-
fessorship of eloquence and of the Greek language at the academy of
Harderwyk. The year after this event Vossius died, and Tollius
delivered on the occasion the customary eulogy, which was printed
under the title 'Oratio in orbitum G. J. Vossi:,' 4to, Amsterdam,
lGi9. During his stay at Harderwyk Tollius exercised great influence
on the affairs of the academy, for the curators are said to have had
such confidence in him that they never appointed a professor without
his previous sanction. The year of his death is not certain, but it
appears to have been soon after 1652; this year at least is the last in
which any work of his appeared.
The works of Tollius are not numerous, but he had formed the
plans for an edition of Valerius Maximus and Phurnutus, which his
early death prevented him from executing. There is an edition of
the work of J. P. Valerianus, 'De Infelicitate Literatorum,' 12mo,
Amsterdam, 1647, v,'ith supplements by Tollius, which give some
interesting accounts of literary men, and was in its time very popular.
The Supplements were translated into French by Coup^, and inserted
in his ' Soirdes Littdraires,' vol. xvi. p. 56, &c. He also edited Pala;-
phatus, ' De Incredibilibus,' 12mo, Amsterdam, 1649, with notes and
a Latin translation ; Joannes Cinnaraus, *De Rebus Joannis et Manuelis
Comneuorum Libri iv.,' with emencfatious and a Latin translation,
4to, Amsterdam, 1652.
Tollius has been charged by his biographers with having appro-
priated numerous remarks and emendations on ancient authors which
he found among the papers of his benefactor Vossius, but how far
this is true cannot now be ascertained.
(Gasp. Burmann, Tivjecium Erudittim, p. 367, &c. ; Saxius, Onomas-
ticum Liter m-ium, vol. iv., p. r>28.)
TOLLIUS, JACOB, a brother of Cornelius, was born about 1630,
fit Utrecht, He received his first education at Deventer, and after-
wards studied under G. J. Vossius, who showed him the same kindness
which he had before shown to his brother Cornelius. The younger
Tollius is charged, and apparently with justice, with having been very
ungrateful towards his benefactor, inasmuch as he appropriated to
himself much which Vossius had written iu illustration of the ancient
writers. After the death of Vossius, Tollius returned to Utrecht, and
became a coi-rector of the press in the printing establishment of J.
Blaeuw, at Amsterdam. He gave perfect satisfaction to his employer,
both by his great knowledge and the conscientious discharge of hia
duties. In the meantime D. Heinsius, who was staying at Stockholm,
and preparing for a journey to Italy under a commission from Queen
Christina, offered to Tollius the place of secretary to the commission.
Tollius accepted the offer, and set out for Stockholm in 1662.
Being entrusted with the various papers and manuscripts of Hein-
sius, his old piratical inclination revived ; when Heinsius discovered
this, and, it would seem, some additional and more serious offences,
Tollius was dismissed, and returned to Holland, where after a short
time the influence of his friends procured him the office of rector of the
gymnasium at Gouda. Here he devoted all his leisure hours to the
study of medicine, and in 1669 he obtained the degree of Doctor of
Physic. Some dispute between him and the curators of the gymna-
sium, and his free and unreserved mode of dealing with them, became
the cause of his being deprived of his office at Gouda in 1673. After
this he for some time practised medicine, and gave private lessons in
Latin and Greek at Nordwyk. Finding that he could not gain a sub-
sistence, he again obtained an appointment as teacher at Leyden, but
in 1679 he gave up his place for that of professor of history and elo-
quence in the University of Duisburg. His reputation as a mineralo-
gist was also great; and in the jear 1687 the elector of Brandenburg
commissioned him to travel through Germany and Italy for the pur-
pose of examining the mines of those countries. It appears that he
faithfully discharged this commission. In Italy he was most hos-
not been promoted iu his own country as he thought he deserved,
secretly embraced the Roman Catholic religion. His long stay in
Italy created in Germany some suspicion of his having renounced
Protestantism; and on hearing this he hastened, in 1690, from Rome
to Berlin. His reception by the elector however was of such a nature
Tollius, being now again without means and employment, opened a
school at Utrecht, but it waa closed by order of ihe city authorities.
Bioa. DIV. VOL. VI.
His friends were displeased with his conduct, and forsook him one
after another; he sank into deep poverty, and died June 22, 1696.
Tho works of Tollius are rather numerous, and are partly philolo-
gical, partly alchymistical, and partly on hia travels. Among bis
alchymistical works are hia ' Fortuita, in quibus pKcter critica non-
nuUa, tota fabularis historia, Grajca, Phoenicia, Aigy [it'inca, ad chemiam
pertinere asseritur,' Amsterdam, 8vo, 1688. He published an edition
of Ausonius, Amsterdam, 1671, which is the Variorum edition of
Ausoniua, and is still very useful; and also an edition of Lon-
ginus, Utrecht, 4to, 1694, with notes and a Latin translation. Tolliu«
translated into Latin the Itnlian work of Bacchini, 'De Sistrj^,'
Utrecht, 1696, and the account of ancient Rome, by Nardini, both of
which are incorporated in Graevius, 'Thesaurus Antiquitatum Roma-
narum,' vols. iv. and vi. He is also the author of ' Gustus Animad-
versionum Criticarum ad Longinum cum Observatis in Ciceronis
Orationem pro Archia,' Leyden, 8vo, 1667. The works relating to his
travels are : — ' Insignia Itinerarii Italic!, quibus continentur Antiqui-
tates Sacrae,' Utrccht, 4to, 1696, and ' Kpistolse Itineraria?, observatio-
nibus et figuris adornataj.' This work was edited, after the author's
death, by H. C. Hennin, Amsterdam, 4to, 1700, and is of greater use
and interest than the former. Tbere are also some dissertations on
ancient poeta, by Tollius, in Berkelius, * Dissertationes selectaj criticse
de Poetis,' Leyden, 8vo, 1704,
TOLOME'I, CLAU'DIO, born at Siena, of a noble family, in 1492,
studied the law in his native town, and afterwards went to Rome,
where he founded an academy called ' Delia Virtti,' of which Caro,
Molza, Flaminio, and other learned men of Rome became memberi",
and one of the purpi ses of which was the illustration of Vitruvius
and the encouragement of architecture. Tolomei afterwards conceived
the idea of introducing into the Italian poetry the Latin metre of the
hexameters and pentameters, and he published rules and specimens
for the purpose : ' Versi e Regole della nuova Poesia Toscaua,' Rome,
Leone Battista Alberti, did not succeed, and the Italian hexameters
and pentameters soon fell into oblivion.
Tolomei was for a time in the service of the Cardinal Ippolito
d'Este, who sent him on a mission to Vienna in 1532. He afterwards
attached himself to the court of Pier Luigi Farntse, son of Pope
Paul III., and duke of Castro, and followed him to Piacenza, when
Pier Luigi waa created duke of Parma and Piacenza. After tho
tragical death of Pier Luigi, in 1547, Tolomei returned to Rome,
where he lived in straitened circumstances, until his countrymen of
Siena chose him, in 1552, for their ambassador to Henri II. of France,
who protected the independence of that republic, thre&tened by the
Medici and by Charles V. Tolomei repaired to Compi^gne, where he
delivered an oration to the king in presence of his court, which was
afterwards published : 'Orazione recitata dinanzi al lid di Fraucia
Enrico II. h, Compiegne,' Paris 1553. He died soon after his return to
Rome, in 1554. He wrote several other orations in Italian, one of
which, entitled ' Oraziono della Pace,' Rome, 1534, has ben most
praised; a dialogue upon the Italian language; and several volumes
of letters, which are the most interesting part of his writings —
'Lettere di Claudio Tolomei, libri vii.,' 4to, Venice, 1547, afterwards
repeatedly reprinted. He is one of the best letter-writers in the
Italian language ; his letters embrace a variety of subjects, scientific
and philosophical, and his style is comprehensive and full of meaning.
His correspondence was choice, and yet exteusive. The edition of
1547 contains an important letter to his friend Gabriele Cesano, about
the manner of making the government of a state durable and perma-
nent, which letter has been left out in the subsequent editions. la
another letter, addressed to Count Lando, he suggests the plan of
several philological and archajological works for the illustration of
Vitruvius. (Corniani, (S'ecoZi della Letleratura Italiana ; Tiraboschi,
Storia della Letleratura Italiana.)
TOMASIN. [Thomasin.]
TOMLINE, GEORGE, eldest son of George and Susan Pretyman,
was born on the 9th of October 1750, at Bury St. Edmund's, Suffolk,
and was educated at the grammar-school in that town, which was the
place of education at that time of most of the gentlemen's families in
Suffolk. At the age of eighteen he was sent to Pembroke Hall, Cam-
bridge. He took his degree of A.B. in January 1772, and obtained the
high honour of senior wrangler, and at the same time the first of Dr.
Smith's mathematical prizes. In the year 1773 he was elected Fellow
of his college, and was immediately appointed tutor to Mr. Pitt. He
was ordained deacon by Dr. Younge, bishop of Norwich, and priest
by Di". Hinchliffe, bishop of Peterborough. In 1775 he proceeded
M.A., and in 1781 was moderator in the university. He resided in
college till 1782, when he left it for the purpose of acting as private
secretary to Mr. Pitt, on his appointment to the chancellorship of the
exchequer. When Mr. Pitt was made first lord of the treasury, Tom-
line became his secretary, and he continued with him till he became
bishop of Lincoln and dean of St. Paul's. Dr. Pretyman's first pre-
ferment was a sinecure rectory of Corwen in Merionethshire, to which
he was collated in 1782 ; and in 1784 he was appointed to a prebendal
stall in Westminster, the first preferment of which Mr. Pitt had the
disposal. In 1785 he was presented by the king to the rectory of
Sudbourn-cum-Offord, in his native county of Suffolk. In January
1787 he was advanced to the bishopric of Lincoln and the deanery of
115
TOMMASEO, NICCOLO.
TONSTALL, CUTHBERT.
116
St Paul's, which were vacated by the promotion of Dr. Thurlow to
the see of Durham, the first bishopric which became vacant after Mr.
Pitt was minister. In 1813 he refused the see of London, and con-
tinued bishop of Lincoln 324 years, in which time he performed the
visitation of that most extensive diocese in the kingdom eleven times,
at the regular interval of three years, which was never done by any of
his predecessors. In July 1820 he was translated to the sec of Win-
chester, in which he continued till September 1827, the time of his
death. His publications, besides single sermons, are ' The Elements
of Christian Theology,' in 2 vols , now a standard work; 'A Refutation
of Calvinism,' in 1 vol.; and *^[emoirs of Mr. Pitt,' in 3 vols. 8vo.
Bishop Pretyman in 1803 assumed the name of Tomline, Marmaduko
Tomline, Esq., having, without any relationship or connection, left him
the valuable estate of Riby Grove in Lincolnshire.
•TOMMASEO, NICCOLO, was born at Sebenico, in Dalmatia, but
was educated in Italy. He became early an author, and for several
years resided at Florence, where he was one of the most able con-
tributors to the ' Antologia.' In 1833, in consequence of having taken
an active part in the revolutionary movements, he was forced to quit
Italy, and resided for several years in France, chiefly in Paris, but also
in several provincial towns, and in Corsica. In 1838, under an
amnesty granted by the Austrian government, he returned to Italy,
where he lived chiefly at Venice, occasionally visiting his birthplace.
Towards the end of 1847, when another movement was commenced
for the freedom of Italy, Tommaseo, in conjunction with Manin, pre-
sented a petition to the Emperor of Austria for a milder exercise of the
censorship of the press. For this act he and Manin were committed to
prison on the 18th of January 1848, but were liberated on the 17th of
March, when the inhabitants of Venice rose against the Austrian govern-
ment. A few days subsequently he was elected a member of the provi-
sional government, but resigned in June on account of a difference of
opinion respecting the proposed union of Lombardy with Piedmont.
In August however he rejoined the government, as minister of religious
affairs and education, in order to resist the hostilities of the Austrians.
To obtain assistance he visited Paris twice, but returned in January
1849 with the conviction that no help was to be looked for in that
quarter. The comparative moderation of Tommaseo lost him much
of his influence during the investment of Venice ; but when the city
was forced to capitulate he was one of those who were obliged to quit
Italy, and he has since resided at Corfu. Notwithstanding the keen
interest he has taken in the political affairs of Italy, his life has been
one of great literary activity ; and since his youthful ardour has
become moderated in expression, his opinions and statements have
become more philosophical and more truly patriotic, uniting a frank
liberalism with devout Roman Catholicism. The learning he has dis-
played, and the variety of subjects of which he has treated, are
remarkable. Of his numerous productions, perhaps the most notice-
able are — * Nuovo dizionario dei sinonimi,' 1832, a work remarkable
for its learning, acuteness, and critical accuracy ; ' Delia educazione,'
1834; 'Nuovi scritti,' in 4 vols., 1839-40, the contents of which are
philosophical and cesthetic ; • Studj critici,' 2 vols., 1843 ; and his
Commentary on Dante contains many happy explanatory references to
the Scriptures and the writinps of the early fathers of the Church.
He has also written ' II Duca d'Atene,' 1836, a romantic history, por-
traying in very dazzling colours that Grecian sovereignty ; a history
of France during the 1 6th century, from materials furnished by the
despatches of the Venetian ambassadors, published at Paris in 1838 ;
and * Lettere di Pasquale de' Paoli,' with an excellent introductory
account of the war for independence in Corsica. In 1839 he published
in 4 vols, a collection of popular poetry, which includes ppecimens of
Tuscan, Coreican, Dalmatian, and Grecian productions, with historical
introductions. Most of his works have gone through seyeral editions.
He has also written some original poetry, which is clever and natural,
but of no great excellence.
TOMMA'SI, GIUSEPPE MARI'A, was born of a noble family at
Alicata in Sicily, in 1649, and entered the congregation of the Teatini
at Palermo in 1664. He was sent to finish his studies at Rome, where
he became acquainted with Cardinal Francesco Barberiui, who, per-
ceiving in him a particular disposition for the study of ecclesiastical
history and antiquities, encouraged him in this pursuit, and obtained
for him access to the archives of the Vatican and other repositories of
church history. In 1680 Tommasi published the collection ' Codices
Sacramentorum nongentis Annis Vetustiores,' which he illustrated
with introductory notices. In 1683 he published an edition of the
' Psalterium,' and in 1686 a collection of ' Antiphouaries ' and
' Responaoriales ' of the Roman Church, illustrated with learned com-
ments and valuable documents. He afterwards edited the ancient
mass-books, a Latin version of the Greek ritual for Good-Friday, a new
edition of the ' Psalterium,' a collection of minor works of the fathers
in three volumes, to serve as an introduction to theological studies,
and another book also to assist the students of divinity, entitled
' Indiculus Institutionum Theologicarum.' Tommasi and his contem-
porary Cardinal Bona of Mondovi, author of Rerum Liturgicarum
Libri duo,' and ' De Divina Psalmodia,' are among the principal illus-
trators and expounders of the liturgy and ceremonies of the Church
of Rome. In 1712 Tommasi was made a cardinal, a dignity which
he at first declined, until the pope expressly commanded him to accept
it. He died in the beginning of the following year.
TONSTALL, or TUNSTALL, CUTHBERT, was bom at Hatch-
ford, in Yorkshire, in 1474 or 1475. It has been commonly stated
that he was a natural son of a gentleman of ancient family, who,
according to one account, was Sir Richai-d Tonstall. His mother is
said to have been a lady of the Conyers family. It has been doubted
however whether there be any foundation for this story. About 1491
he was sent to the University of Oxford, where, according to some
authorities, he was entered a student of Balliol College ; but the plague
soon drove him to Cambridge, where ho is known to have eventually
become a Fellow of King's Hall (now incorporated with Trinity
having taken the degree of Doctor of Laws, returned to England with
the highest reputation for classical, legal, and scientific, as well as
theological learning. His first patron was Warham, archbishop of
Canterbury, who, in 1511, made him his vicar-general, collated him to
the rectory of Harrow-on-the-Hill, and also introduced him at court.
In 1514 he was promoted to a prebend in the cathedral of Lincoln ; in
1515 he was admitted archdeacon of Chester; and in May 1516, he
was appointed master of the rolls, an office at this date often held by
clergymen.
Towards the close of this same year he was sent to Brussels as chief
commissioner to Charles, the young king of Spain and the Low
Countries (afterwards the Emperor Charles V.), with whom he con-
cluded two treaties of alliance and commerce ; and here he made the
acquaintance of Erasmus, who describes him, in one of his letters, as
not only the most eminent Greek and Latin scholar among his country-
men, but also a pei-son of the most comprehensive judgment and the
nicest taste, and withal of remarkable modesty and the most agreeable
and cheerful manners, yet without going beyond the bounds of a
becoming gravity. Erasmus adds that, much to his delight, he
boarded at the same table with TonstalL In 1517, within ten days
after his return home, he was sent on a second embassy to Charles.
In 1519 he was collated to a prebend in the cathedral of York ; and in
1521 to another in that of Salisbury, of which diocese he was also at
the same time elected dean. The next year he was promoted to the
bishopric of London : his consecration took place on the 9th of Octo-
ber, his enthronization on the 22nd. He now resigned his office as
master of the rolls; but in May 1523, he was introduced into the
government by being made lord privy seal. After this he was em-
ployed in various diplomatic missions : having been sent to Spain on
an embassy to the emperor in 1525 ; having accompanied Cardinal
Wolsey in his embassy to France in 1527 ; and having along with Sir
Thomas More represented the English king at the negociation of the
treaty of Cam bray in 1529. At Antwerp, on his return from Cam bray,
Tonstall, as the story is related by the old chronicler Hall, purchased
from an English merchant named Packington all the copies that
remained unsold of Tyudal's translation of the New Testament, and
bringing them home with him, made a bonfire of them in Cheapaide —
the effect of which was to enable Tyndal to publish next year a
second and more correct edition with the bishop's money.
In 1530 Tonstall was translated to the bishopric of Durham; and
now, or soon after this, he appears to have resigned the privy seal.
In the religious changes that now began to be enforced by the royal
authority, his mild and compliant temper carried him nearly as far as
Henry himself went; he supported the divorce of Queen Catherine
(although it has been supposed that he latterly somewhat changed his
opinion on that question) ; he preached and wrote in favour of the
king's assumption of ecclesiastical supremacy ; and, along with Heath,
bishop of Rochester, he revised the English translation of the Bible
scientious belief, or love of quiet, he appears to have retained to the
last an attachment to most of the doctrinal theology of the ancient
church. Yet, like the generality of the other bishops, he acquiesced
in the additional innovations of all kinds that were made in religion
on the accession of Edward VI., in 1547 ; and accordingly he not only
preserved his seat in the privy council, but was also made a member
of the king's council in the north. In May 1551, however, he was
accused belore the council of being privy to the design of an iniur-
rection in the north ; upon which he was in the first instance com-
manded to keep his house ; and afterwards, on a letter in his hand-
writing, deemed to be confirmatory of the charge, being found among
the papers of the Duke of Somerset, which were seized in December of
that year, he was committed to the Tower, and a bill was brought into
the House of Lords to deprive him of his bishopric. But, although
the bill was passed by that House, all the influence of the new head of
the government, tho Duke of Northumberland, proved insufficient to
satisfy the objections of the Commons, and they i-efused to proceed
with iL The precise nature of the charge is not known ; and it seems
highly improbable, from Tonstall's character, that he should have
involved himself in any insurrectionary or other treasonable scheme.
In the Lords the bill was strongly opposed by Cranmer, who " spoke
so freely against it," says Burnet, " that the Duke of Northumberland
and he were never after that in friendship together." The duke how-
ever was not to be cheated of his prey : the parliament was dissolved
in April 1552; but on the 2lBt of September ther^^after a commission
was issued to the chief justice of the King's Bench and seven others,
empowering them to call Tonstall before them, to examine him touch-
ing all manner of conspiracies, &c., and, if they found him guilty, to
117
TOOKE, JOHN HORNE.
TOOKE, JOHN IIORNE,
118
deprive him of bis bishopric ; and by this tribunal he was in fact
deprived ou the 14th of October.
lie remained a prisoner iu the Tower for the remainder of King
Edward's reign ; and the bishopric of Durham having been dissolved
by act of parliament, in April 1553, Northumberland obtained a grant
of the greater part of its jurisdiction and revenues, with the title and
dignity of Count Palatine. In a few months liowover the accession of
Mary again changed everything; and Tonstall, released from prison, was
reinstated in his bishopric, which the queen erected anew by letters-
patent. His own sufferings had not given Tonstall any taste for perse-
cution; and ho principally distinguished himself throughout this reign
by the moderation of his conduct and the aversion he showed to the
violent courses urged by the court and followed with little reluctance
by most of his right reverend brethren. No burning of heretics took
place in his diocese ; and, suspected on this account to be half a Pro-
testant at heart, he lived under a cloud in so far as regarded the
favour of the court. Nevertheless when Elizabeth came to the
throne he refused to take the oath of supremacy ; and he was deprived
on that account, in July 1559. Being committed to the charge of his
Canterbury, and in possession of Lambeth, Tonstall "lived there,"
says Lloyd (in his ' State Worthies'), "in sweet chambers, warm beds,
by warm tires, with plentiful and wholesome diet, at the archbishop's
own table : differing nothing from his former grandeur, save that
that was at his own charges, and this at another's ; and that he
had not Ids former suite of superfluous servants — that long train, that
doth not warm, but weary the wearer thereof." Tonstall only enjoyed
Parker's hospitality for a few months : he died on the 18th of
November 1559.
The character of Tonstall may be collected from this sketch of his
liistory. He will scarcely be allowed the credit of principle by the
more severe class of moralists : but although not made to be a martyr,
he had evidently many excellent moral qualities. Intellectually he
was rated very high in his own day : Erasmus, More, Warham, Gran-
mer, and Parker, were all among his admirers and attached friends.
Besides various scattered letters, speeches, and other short composi-
tions, some in print, some in manuscript, for a list of which we must
refer to the 'Biographia Britannica,' Bishop Tonstall is the author of the
&c. (a Latin Oration pronounced at the betrothment of the Princess
Mary and Francis, eldest son of the king of France), 4to, London,
1518 ; 2, * De Arte Supputandi Libri Quatuor' (a treatise on Arithme-
tic), 4to, London, 1522, and frequently reprinted at Paris, Strasburg,
and elsewhere on the Continent, as well as in England. The writer of
' Notices of English Mathematical and Astronomical Writers between
the Norman Conquest and the year 1600,' in the ' Companion to the
Almanac for 1837,' says, " In point of simplicity this work stands
alone in its age, and is perfectly free from all the extraneous matter
which was often introduced into the scientific works of the day." 3,
A Sermon preached on Palm-Sunday, 1538, before King Henry VIII.
on Philippians, ii. 5- 12 (in support of the royal supremacy), 4to,
London, 1539, and again 1633 ; 4, *De Veritate Corporis et Sanguinis
Domini Nostri Jesu Christi in Eucharistia" (in defence of Transubstan-
tiation), 4to, Paris, 1554 ; 5, ' Compendium et Synopsis,' &c., an
abridgment of Aristotle's Ethics, 8vo, Paris, 1554; 6, 'Contra Impios
Blasphematores,' &c., a defence of Predestination, 4to, Antwerp, 1555;
7, ' Godly and Devout Prayers in English and Latin,' 8vo, 1558.
TOOKE, JOHN HORNE, was the son of John Home, a poulterer
in Newport-street, Westminster, where he was born on the 25th of
June, 1736. The name of Tooke he assumed afterwards for reasons
mentioned below. He was educated at Westminster and Eton schools,
at the former of which he remained two, and at the latter five years.
In 1755 he went to St. John's College, Cambridge, and took his degree
of B.A. in 1758. After leaving Cambridge he officiated for a short
time as usher in a school at Blackheath, and in 1760 took deacon's
orders, and obtained a curacy in Kent. He entered the church
through the wishes of his father, but" against his own inclinations.
He had wished himself to study for the bar, and with this view
had entered his name at the Inner Temple iu 1756, In 1760 he
received priest's orders ; and in the course of the same year was
inducted to the chapelry of New Brentford, which his father had
purchased for him. He was however never happy in discharging the
duties of his profession, and gladly embraced the opportunity of
leaving New Brentford for more than a year upon two different
occasions, in order to travel on the Continent as tutor to the sons of
gentlemen in his neighbourhood. What he thought of his profession
may be seen from a letter of his to Wilkes, whose acquaintance he
made in Paris in 1765, and to whom he thus writes : " You are now
entering into correspondence with a parson, and I am greatly appre-
hensive lest that title should disgust : but give me leave to assure you,
I am not ordained a hypocrite. It is true I have suffered the in-
fectious hand of a bishop to be waved over me ; whose imposition,
like the sop given to Judas, is only a signal for the devil to enter. I
hope I have escaped the contagion; and, if I have not. if you should
at any time discover the black spot under the tongue, pray kindly
assist me to conquer the prejudices of education and profession."
Yet he continued for eight years longer to hold the benefice he thus
coarsely acknowledged himself utterly unjustified in holding.
On his second return from the continent in 1767, Horno took an
active part in the political contests of the day, and it was greatly owing
to his exertions that Wilkes was returned as member for the county
of Middlesex in 1768. Home's opposition to the ministry was un-
ceasing, and he soon became one of the most popular men of tlie day.
He was the founder of the ' Society for supporting the Bill of Rights,'
in 1769, in which he was closely associated with Wilkes : but in the fol-
lowing year a quarrel took place between them, which led to an angry
paper war, in consequence of which Home lost much of his popularity.
In 1771 he took his degree of M.A,, which was granted to him,
notwithstanding the opposition of many of the members of tlie
university, and among others of Dr. Paley. His quarrel with Wilkes
drew upon him in the same year the attack of Junius, whom he
His occupations were now so entirely opposed to the clerical pro-
fession, and his dislike to it, as well as the gross inconsistency of
remaining in it with his avowed principles, had become so great, tliat
he resigned his living in 1773 with the view of studying for the bar.
That he might not want the means of doing so, four of his friends
presented him with joint bonds to the amount of 400^ a year, which
were to continue in force till he was called to the bar. While pro-
secuting his legal studies, he afforded great assistance to Mr. William
Tooke, an old friend of his, in resisting an inclosure bill, which would
have greatly deteriorated the value of some property which Tooke had
purchased at Purley, near Godstone in Surrey. In return for his
services Mr. William Tooke made him his heir ; and it was upon this
occasion or shortly afterwards that he assumed the name of Tooke, by
which he is commonly known.
On the breaking out of the American War, Tooke vehemently
attacked the conduct of the ministry, and opened a subscription for
the widows and orphans of the Americans, " murdered," as he said,
" by the king's troops at Lexington and Concord." The ministry
prosecuted him for a libel in 1777; he was found guilty, condemned
to pay a fine of 200?., and to be imprisoned for twelve mouths. While
in prison he published his letter to Mr. Dunning, which is occupied
with a critical examination of the case of ' The King and Lawley,'
which had been quoted as a precedent against him in his trial : this
examination leads him to explain the conjunctions and prepositions of
the English language. This letter formed the basis of a considerable
part of the first volume of the ' Diversions of Purley.'
Shortly after his release from prison, he applied in 1779 to bo
called to the bar, but he was rejected by the benchers on the ground
of his being a clergyman. This blighted all his prospects in life, and
he soon afterwards retired from London to a farm in Huntingdon-
shire. He had however previously published, in conjunction with
Dr. Price, a pamphlet against the American War, entitled ' Facts '
addressed to the landholders, stockholders, &c. of Great Britain.
Tooke did not remain long in Huntingdonshire, and on his return to
London he took an active part in advocating the cause of parlia-
mentary reform, which Mr. Pitt then espoused. He published a letter
in favour of it in 1782, addressed to his friend Mr. Dunning, then Lord
some years, and when Mr. Fox came into power by the coalition
ministry, as it was called, he published his celebrated ' Two Pairs of
Portraits,' 1788, in which he contrasts the character and conduct of
Lord Chatham and Lord Holland, and of Mr. Pitt and Mr. Fox
respectively. Two years previously to this he published the first
volume of his * Eirea. nrepoei/To,' or the ' Diversions of Purley,' in
octavo, the latter of which names was given to the work in compli-
ment to the residence of his friend Mr. William Tooke.
In 1790 Tooke became a candidate to represent the city of West-
minster in parliament; and though he spent nothing upon the
contest, he polled nearly 1700 votes. In 1794 he was arrested on a
charge of high treason, mainly as it appears on account of his con-
nection with the ' Constitutional Society.' Nothing however of a
treasonable nature could be proved against him, and he was accord-
ingly acquitted after a trial which lasted six days, during which he
distinguished himself by his calmness, intrepidity, and presence of
mind. His domestic affairs having become very much embarrassed,
his friends came forward to his assistance and settled on him a pension
of 600?. a year. In 1796 he again offered himself as a candidate for
Westminster, and polled on this occasion upwards of 2800 votes. His
desire of obtaining a seat in parliament was at length gratified, though
not exactly in a way which best accorded with the principles of a
reform. He was returned in 1801 for the borough of Old Sarum by
Lord Camelford. Ho retained his seat till the dissolution of parlia-
ment in the following year, but was disqualified from sitting again in
consequence of an act of parliament, which was passed while he was
in the house, enacting that in future no one in priest's orders should
be a member of the House of Commons.
Mr. Tooke now retired into private life, and passed the remainder of
his life at Wimbledon, where he had already resided for many years.
He had published a second edition of the ' Diversions of Purley' in
1798, in one volume, quarto, and this was now followed by the second
volume in 1805, He died on the 18th of March, 1812, in the seventy-
seventh year of his age. He was never married, but had several
illegitimate children, to one of whom he left his property.
119
TOOKE, REV. WILLIAM, F.R.S.
TORDENSKIOLD.
120
Mr. Tooke was a man of great powers and coQsiderable attainments.
He was well read in English, French, and Italian literature, possessed a
tolemblc knowledge of Latin and Greek, and had studied Anglo-
Saxon with some diligence. In private he was much beloved, and his
conversational powers are particularly celebrated by all who knew
him. He is however principally known in the present day by the
'Diversions of Purley,' a work whicli has exercised considerable
influence upon the works on the English language published since its
appearance. It is written in the form of a dialogue : the principal
speakei-s in the first volume are Mr. Tooke himself, and his frieud
Dr. Beadon, the Master of Jesus College, Cambridge ; Mr. William
Tooke is occasionally admitted to take part in the dialogue : in the
second volume the only speakers are the author and Sir Francis
Burdett Tiie firt^t volume is divided into ten chapters :. the first
treats ' Of the Division and Distribution of Language ; ' the second
contaios ' Some Considerations < f Mr. Locke's Essay on the Human
Understiinding;' the third treats 'Of the Parts of Speech,' in which
nil words necessary for the great purposes of speech are resolved into
" words necessary for the communication of our thoughts," and
"abbreviations employed for the sake of despatch;" in respect to the
former we are told that in English and in all languages there are only
two sets of words necessary for the communication of our thoughts,
and tliat these are nouns and verbs. The fourth chapter treats ' Of
the Noun,' and the fifth ' Of the Article and Interjection.' The
substance of the three next chapters, 'On the word That,' 'Of Con-
jonctions,' and 'Etymology of English Conjunctions,' had been pre-
viously given in the letter to Mr. Dunning. The tenth chapter speaks
' Of Adverbs.' In the second volume, the first chapter treats ' Of the
Rights of Man ; ' the second, third, fourth, and fifth, ' Of Abstraction;'
and the sixth, seventh, and eighth, ' Of Adjectives and Participles.'
It is impossible to read this work without deriving information from
it. It contains many happy explanations and conjectures, but the
young student cannot be cautioned too strongly against receiving all
the conclusions of the author. The great fault of the book is the
love of hypothesis, and the absence to a great extent of that historical
mode of investigation without which etymological studies are worse
than useless. A useful edition of the work has been published by
Richard Taylor, with notes, London, 1840.
TOOKE, REV. WILLIAM, F.R.S., was bom on the 18th of January
1744, and educated at a private academy at Islington, kept by Mr.
Shield, where he had for schoolfellows the indefatigable and amiable
antiquarian Mr. John Nichols, and Dr. Ed. Gray, of the British
Museum, Sec. R.S., with each of whom he kept up a cordial intimacy
during their lives. He was ordained a clergyman of the Church of
England in 1771, by the then Bishop of London, and shortly after-
wards obtained the situation of minister of the English church at
Cronstadt, the naval arsenal and commercial port of St. Petersburg.
In 1774 he was appointed chaplain to the factory of the Russia
Company at St. Petersburg, in which situation he remained for
eighteen years. He often preached in the chapel of the French Pro-
testants at St. Petersburg in the French language, of which he was
a complete master; and after his return to London he preached on
several occasions in that language on behalf of the French Protestant
School and Workhouse in London. He returned to England in 1792,
in consequence of succeeding to a considerable property by the death
of his maternal uncle, which enabled him to dispense with all profes-
sional exertion. He died in London, November 17, 1820, in his
seventy-seventh year, much esteemed by a large circle of literary
friends. By his wife Elizabeth, daugther of Thomas Eyton, Esq., of
Llangynhavil in Denbighshire, he had a daughter and two sons, who
survived him.
Mr. Tooke was the author of several works, of which the most
important are those relating to Russia, namely, a ' Life of Catherine
II.,' 3 vols. 8vo; 'A View of the Russian Empire,' 3 vols.; and 'A
History of Russia, from the Foundation of the Empire to the Acces-
sion of Catherine II.' Mr. Tooke was also a joint editor with Arch-
deacon Nares and Mr. Beloe, of the * General Biographical Dictionary,'
in 15 vols. 8vo, 1798; his portion of the work was the first five
volumes. Besides this he published, early in life, ' Othniel and
Achsah,' an Oriental tale from the Chaldee, in 2 vols., and long after-
wards four volumes of miscellaneous essays under the title of
'Varieties of Literature,' and 'Selections from various Foreign Literary
Journals.' He translated Zollikofer's sermons from the German, in
10 vols. 8vo, and Lucian's works, in 2 vols. 4to, with the notes of
Wieland. The Lucian however is not a translation from the original
Greek, but from Wieland's version ; and where the latter did not give
the meaning of the Greek, recourse was had to the original.
{1^ ichoW a Literary Anecdotes ; and Gentleman's Magazine for May,
1816 ; November 1820; and December 1839.)
* Tooke, Thomas, one of the two sons of the Rev. William Tooke,
published in 1838 ' A History of Prices and of the State of the Cir-
culation from 1793 to 1837, preceded by a brief Sketch of the State
of the Corn-Trade in the last Two Centurif s,' 2 vols. 8vo. The treatise
comprised in these two volumes, though appai-ently an enlargement
and continuation of one published about fifteen years previously under
the title of ' Thoughts and Details on the High and Low Prices of the
last Thirty Years,' embracing, as it does, the same line of argument
and establishing tlie same conclusions, is yet essentially different both
in its arrangement and details, and is in fact, with slight exceptions,
entirely new. It forms the first two volumes of the valuable work
now well known to political economists as the * History of Prices,*
perhaps the first really scientific attempt to elucidate by inferences
legitimately deduced from actual experience the complicated facts of
this branch of political economy. The first two volumes were followed
in 1840 by another volume, in continuation of the two former, to which
were added 'Remarks on the Corn Laws and on some of the Alterations
proposed in our Banking System.' The fourth volume was entitled
'A History of Prices and the State of the Circulation from 1839 to
1847 inclusiye; with a General Review of the Currency Question, and
Remarks on the Operation of the Act 7 & 8 Vict., c. 32,' 8vo, 1848.
Mr. Tooke afterwards published a tract, in which he was a.ssisted by
Mr. Newmarch, 'On the Bank-Charter of 1844, its Principles and
Operation, with Suggestions for an Improved Administration of the
Bank of England,' 8vo. The last two volumes of his great work are
entitled 'A History of Prices and the State of the Circulation during
the Nine Years 1848-1856, in Two Volumes, forming the Fifth and
Sixth Volumes of the History of Prices from 1792 to the Present
Time, by Thomas Tooke, F.R.S., Corresponding Member of the Insti-
tute of France, and William Newmarch,' 8vo, 1857. The 5th and
6th volumes, besides being a continuation and completion of the
work, arranged under the heads Prices of Corn, Prices of Produce
other than Corn, and the State of the Circulation, contains discussions
on the connected topics of Railways and the Railway System, the
Origin and Progress of the Free-Trade Movement, the State of Finance
and Banking in France, and the New Discoveries of Gold.
* Tooke, William, F.R.S., the younger son of the Rev. William
Tooke, was born in 1777, at St. Petersl)urg. He was bred to the law,
and continued many years in practice as a solicitor in London. Ho
published in 1804 anonymously 'The Poetical Works of Charles
Churchill, with explanatory Notes and an authentic Account of his
Life,' 2 vols. 8vo, which was republished in 1844, with his name, as
one of the 'Aldine Poets,' under the title of 'The Poetical Works
of Charles Churchill, with copious Notes and a Life of the Author,'
3 vols. Mr. William Tooke was influential in the establishment of the
Society for the Diffusion of Useful Knowledge, of which he became
the Treasurer. He has since published ' The Monarchy of France,
its Rise, Progress, and Fall,' 8vo, 1855.
TORDENSKIOLD, Vice-Admiral in the Danish navy. His name
was Peter Wessel before he was ennobled by King Frederick IV.
Bom on the 28th of October 1691, at Trondheim in Norway, of
obscure parents, he was at an early age bound apprentice to a barber,
but his strong desire for a seafaring life induced him to leave his
master and go to Copenhagen as cabin-boy. There he entered the
service of the East India Company as a common sailor, and in his
third voyage distinguished himself so much, that by the recommenda-
tion of his captain he obtained an appointment as midshipman in the
royal navy. In the year 1709, immediately after the battle of Pultawa,
Denmark declared war against Sweden, and from that time Wessel's
brilliant career commenced. From 1709 to 1711 he commanded a
small privateer, and made many prizes. He was promoted to the rank
of lieutenant in 1712, and shoi-tly afterwards had the command of a
small frigate, in which he cruised against the Swedish traders with
such effect, that it is said that the Gothenburg and Calmar merchants
offered him a hundred thousand crowns if he would resign his com-
mand. On the 5th of June 1712 he met a Swedish frigate of nearly
double the size of his own, under English colours. Tordenskiold
hoisted the Dutch flag, and by a skilful manoeuvre laid alongside the
enemy within hailing distance, and the Swedish captain, still believing
him to be Dutch, hailed him. The answer was a destructive broad-
side. A most obstinate engagement ensued, in which Tordenskiold
ammunition was exhausted. Upon this he hailed the Swedish captain,
telling him the roughness of the sea alone prevented him from board-
ing the frigate and taking her ; but that if he either would lend him
some powder or pledge his word to await his return within three days
off the Drammen, he would promise to carry him as a prize to Copen-
hagen. Both proposals were declined, but the Swedish captain express-
ing a lively wish to become personally acquainted with his gallant
adversary, Tordenskiold went on board to him, and drank to the King
by a court-martial, but honourably acquitted ; and King Frederick,
pleased with his chivalrous conduct, promoted him to the rank of
captain. During his stay in Copenhagen, he submitted to the king
personally a plan for attacking the Swedish coast, which the Admi-
ralty however, being annoyed at the young man's rapid promotion and
increasing favour, rejected with great disdain. He left Copenhagen oil
the 24th of April 1715, his frigate being then attached to the fleet
xinder Admiral Gabel, who despatched him for the purpose of recon-
noitring the Swedish fleet, commanded by Admiral Wachtmeister, on
the coast of Norway. Here, by his extraordinary seamanship and
boldness, he was principally instrumental in destroying four ships of
the line and three frigates, besides a large frigate which he captured,
and in which, as a due reward for his eminent services, ho was sent to
Copenhagen as bearer of the glorious tidings. For this exploit he
was raised to the rank of commodore, and a short time afterwai'ds he
was appointed to the command of a squadron destined to cruise in
121
TORELLI, GIUSEPrE.
TORENO, DON JOS^>, COUNT OF.
122
the Baltio for the purpose of intercepting transports with frqsk
supplies of troops for Charles XII., then in Pomerania.
On the 7th of August 1716, off the island of Riigen, ho came in
sight of the Swedish fleet commanded by Wachtmeister. Charles XII.
himself stood on an eminence on the island to see the victory of his
flag, as to which there could scarcely be a doubt, as the Swedish fleet
amounted to more than double the number of ships of Tordenskiold's
squadron. But better acquainted with the bearings and the ground
he was on, and much more skilful in seamanship, Tordenskiold soon
gained the weather-side of the enemy, and then kejit up his fii-e witli
such precision and rapidity, that in an hour three of the Swedish
ships of the line and two frigates had struck ; and the Swedish loss in
killed and wounded, besides one vice-admiral, amounted to more than
three times that of the Danes. A gold medal was struck in comme-
moration of this victory, which the king permitted him to wear sus-
pended by the blue ribbon of the Order of the Elephant, a distinction
only twice grautod before.
In the battle of Dyneskiln, July 17, 1717, and in that of Stroem-
staedt, he fought with the same gallantry and success. In December
1717 the king raised him to noble rank by the name of Tordenskiold
(shield against thunder). The immediate cause of this new honour
was characteristic. On a very cold day Tordenskiold went on shore
with a party of oflScers to dine with the king. By a sudden pitch of
the boat he lost a golden snuff-box, with the king's portrait set in
dian^ouds, and presented to him by his majesty. He immediately ex-
claimed, "Rather die than lose that which my sovereign has given me ! "
and before his friends could prevent it, he threw himself overboard,
and dived several times after it, till he at last was taken up senseless.
On the 26th of July 1717 he took Marstrand, one of the most
important Swedish fortifications in the Kattegat, The peace of
Fredriksborg having been signed (July 23, 1720), Tordenskiold had a
great desire to visit foreign countries. King Frederick gave his con-
sent very reluctantly. At Hamburg, where he was received with
princely honours, his travelling companion, a wealthy young man
from Copenhagen, lost large sums at play to a Swedish colonel, De
Stahl ; and after his ready cash was exhausted, gave drafts upon his
father to the amount of 30,000 crowns. Tordenskiold, upon being
informed of it, declared his intention to call the gambler to a strict
account; but the colonel having left Hamburg, Tordenskiold went to
Hanover to be presented to George II. There, the '^''y after his
arrival, he met Colonel Stahl at a dinner-party with one of the
ministers. He immediately expressed his indignation and reluctance
to dine at the same table with him. A violent quarrel ensued, and a
hostile meeting was appointed for the following day at a place some
miles distant from the capital. Tordenskiold went without a second,
and only armed with a light dress-sword. Colonel Stahl used a heavy
sword, with which he shivered his adversary's blade at the first onset,
and then ran him through the heart. Tordenskiold expired in a few
minutes, recommending his soul to Heaven, and charging his faithful
valet to take his body to Copenhagen, where it was deposited in a
chapel of ' the navy church (Holmeus Kirke) : the king himself
attended the funeral. The general impression in Denmark at the
time was that foul play had been practised by instigation from a
higher quarter.
{Peter Tordenskiolds lAv, og Levnet, 3 vols. 4to, Kiobenhavn, 1747 ;
Peter Suhm's Ilistorie af Dannemark, Norge, &c., 1 vol. 8vo, Kioben-
haven, 1787 ; Histoirede Bannemarc, par M. P. H. Mallet, 9 vols. 8vo,
Paris and Geneva, 1788.)
TORELLI, GIUSEPPE, an Italian mathematician, was born at
Verona, in 1721. Having received the rudiments of education in that
city, he was sent to the University of Padua, where he distinguished
himself by his assiduity in cultivating both literature and science, and
where he obtained a Doctor's degree. Engaging in no profession, he
prosecuted the study of the ancient and modern languages, and at the
same time he applied himself particularly to the writings of the Greek
geometers. He is chiefly distinguished by his edition in Greek and
Latin of all the works of Archimedes, in the preparation of which he
was engaged during the greater part of his life, and for which his
talents as a mathematician, as well as the extent of his classical attain-
ments, particularly qualified him : he had not however the satisfaction
of enjoying the fruits of his labours, for he died in 1781, almost at
the moment of the completion of the work. The manuscript was
sold after hjs death to the University of Oxford, and, under the
superintendence of Dr. Abram Robertson, the work was published in
1792 by the curators of the Clarendon Press. This splendid edition
contains the notes of the ancient commentators, and the observations
of Torclli himself on the tract ' De Conoidibus et Spheroidibus ;' and
to these are added the various readings which occur in the manuscript
copies of Archimedes in Paris and Floi-ence, together with a commen-
tary by the Oxford editor on the tract relating to floating bodies.
TORELLI, LAELIO, was born at Fano, on the 28th of October
1489. His family was noble, and had settled in that town about the
beginning of the 14th century. While yet a mere boy he was
entrusted to the care of his maternal uncle, Jacopo Costanzi, a pro-
fessor in the University of Ferrara, under whom he made a respectable
progress in the Greek and Latin languages. He subsequently studied
law in the University of Perugia, and obtained the degree of Doctor in
his twenty-second year.
' . From 1511 to 1631 Torelli remained in the civil service of the Roman
government. Soon after taking his degree he was appointed podestb.
of Fossombrone, and in a short time chief magistrate of his native
town. Scanderbeg Comnena, who had lost his hereditary states by
becoming a convert to the Romish faith, received from the pope by
way of compensation the seignorage of Fano. By his insolent abuse of
power he rendered himself odious to his new subjects, and was
expelled by a conspiracy, of which Laelio Torelli was the chief.
Clement VIII. was at first much irritated, regarding the rebellion as
directed against the papal government; but Laelio, by explaining its
real object, succeeded in pacifying him, and was soon after appointed
governor of Benevento. This post h« occupied for eighteen months,
at the end of which, returning to Fano, ho became involved in the con-
test between that town and the Malatesti family ; and about 1527 or
1628, found it advisable to seek an asylum in Florence.
In 1531 he was appointed one of the five auditors of the Rota of
Floi-ence, and he continued from that time till his death in the service
of the Medici family. During far the greater part of this time he was
attached to Cosmo, the first grand-duke of Tu.scany, who became Duke
of Florence six years after the first appointment of Torelli, and died
only two years before him (in 1574). From being a member of the
Rota, Torelli rose to be podesth. of Florence; he was subsequently
appointed chancellor by the grand-duke, and in 1546 his principal
secretary. His official duties did not entirely withdraw him from
literary pursuits. He was an active member of the Florentine Aca-
demy, and in 1557 was elected into its council. His reputation as a
statesman and man of letters procured him the honour of being
elected a senator : his name was inscribed in the register of the
patricians of Florence in 1576. He died in the same year, in the
month of March, having survived all his children.
Torelli published, in 1545, three legal tracts, entitled 'Laelii Taurelli
Paulum Enarrationes ; ejusdem de Militiis ex" casu, ad Ant. Augus-
tinum epistola,' dedicated to his son Francesco. They were printed
at Lyon ; the Antonius Augustinus (bishop of Tarragona), to whom
the third is addressed, printed it in 1544 as an appendix to his
* Emendationes ; ' and Zilettus included them in bis great collection,
' Tractatus Tractatuum ' (1633-42), A Latin eulogium of Duke
Alexander de' Medici, delivered by Laelio in 1536, and a panegyric of
Count Ugo, the founder of an abbey at Florence, in Italian, are said to
have been printed. But the work which has preserved the name of
Laelio Torelli is his edition of the Florentine manuscript of the Pan-
dects. It was printed at Florence by Lorenzo Torrentino, printer to
the grand-duke, in 1553. From the dedication to Cosmo I., which is
written by Francesco Torelli, we learn that the preparation of the
transcript and the supervision of the press had occupied all his own
and his father's leisure hours for the ten preceding years. Francesco
claims for his father the honour of projecting the edition, and gives
Cosmo the credit of defraying the expense of the sumptuous pub-
lication. The orthography and all the little peculiarities of the
manuscript are said to have been strictly adhered to. The Greek
passages were revised by Peter Victor. The translations of these
passages are taken from Antonius Augustus Haloander, and Her-
vagius. This edition is a fine specimen of typography, and worthy
of the important monument it was the means of rendering more
accessible to the public. The pope, the emperor, and the king of
France gave the printer letters of protection against any piracy of the
work for ten years, and Edward VI., the king of England, for seven.
With regard to the Florentine (or Pisan) manuscript, the inquiries of
Savigny, Blume, and others have established this to be the oldest
copy of the entire Pandects of Justinian that exists. Leaving out of
view the story of its discovery at Amalfi, the assertion of Odofredus
that it waa transmitted to Pisa by Justinian, and the statement of
Bartolus that it was "always" at Pisa (semper enim fuit totum volu-
men Pandectarum Pisis et adhuc est), established for this manuscript
of the Pandects an antiquity beyond what can be claiined for any
other. Borgo dal Borgo has produced evidence to the extraordinary
care taken for its preservation by the government of Pisa; and the
government of Florence has watched no less anxiously for its safety
since it was transferred to that city in 1406, after the capture of Pisa
by the Florentines under Gino CaponL The Florentine manuscript
must always remain one of the most important authorities for the
text of this portion of the Corpus Juris, and Torelli .appears to have
discharged the oSice of editor with a full sense of the importance
The contemporaries of Laelio Torelli are unanimous in their testi-
mony to the integrity and disinterestedness of his character.
(Manni, Vita di L, Torelli ; Savigny, Geschichte des Eomiscken RecMs
im Mittclalter ; Laelii Taurelli Jurisconsulti .Fanensis, ad Oallum et
Legem Velleam, ad Catonem et Paulum Enarrationes; ejusdem de
Militiis ex casu, Lugduni, 1545 ; Digesforum, sen Pandectarum LihH
Quinquaginta ex Pandectis Florentinis reprcesentati : Plorentim in
officina Laurentii Torrentini Ducalis Tqpograj)hi, 1553.)
TORENO, DON JOSfi MARIA QUEIPO DE LL.\NO, Count of,
a Spanish statesman and writer, was born at Oviedo on the 26th of
November 1786, of one of the first families of the Asturias. In 1797
his parents, of whom he was the only son, fixed their residence at
123
TORENO, DON JOSfi, COUNT OF.
TORFAEUS.
124
uDcomtnon at that time ia Spain; as it included the study of Euglish
and even German aa well as French and Italian. After the national
insurrection of the 2nd of May 1808, in which he took a part, he
returned to Oviedo where, as Viscount of Matarrosa,he held an heredi-
tary seat in the Junta, and when the city rose against Napoleon he
was selected, from his knowledge of English, to make his way to
London to ask the assistance of England. In company with Don
Angel de la Vega he got on board of a Jersey privateer, and was
received at London with open arms by Canning. After spending
some months in England, where he made the acquaintance of Wilber-
force, Windham, and Sheridan, he returned to Spain in December,
and, having lost his father in the interval, he succeeded to the title of
Count of Toreno. He was sent to the Cortes as a member for the
Asturias when a year too young to be able legally to take his seat,
but by a vote of the Cortes on the 11th February 1811 he enjoyed
the distinction of being specially exempted from the operation of the
law. Young as he was he took a prominent part in the discussions on
the constitution of 1812, and advocated with success two of the
measures which most contributed to its subsequent downfall — one,
that the Cortes should coneist of a single chamber instead of two,
and the other that the power of the king should be so restricted that
all legislation should depend on the decision of the Cortes only. On
the return of Ferdinand he was a marked man ; when the celebrated
decree of Valencia came forth, by which the Cortes was dissolved and
many of its members thrown into prison, he was fortunately on bis
estates in the country and had time to escape to Portugal. As he
found there was no hope of resistance in Spain, he came to London
where he was the first emigrant from the tyranny of Ferdinand, as he
had been the herald of resistance to Napoleon L He received in
London the intelligence that his estates had been confiscated and him-
8elf condemned to death. His brother-in-law Porlier, who had married
one of his four sisters, made an ineffectual attempt at insurrection,
and was taken and executed. Toreno, who in 1816 was living in
France, was thrown into prison for a time on suspicion by the Decazes
ministry, who interrogated him if he was not in habits of intercourse
with the Duke of Wellington and General Alava, two persons whom
it appeal's that the king of Spain then regarded as enemies. The
Spanish revolution of 1820 recalled Toreno to Madrid, but be was
now older and cooler than ho had been, and saw with disapprobation
many of the measures of the liberal party. His life was in con-
sequence threatened in the Cortes, his house in which his sister, the
widow of Porlier, resided, was attacked and, says Cueto his biographer,
" levelled to the ground." The king, on the other hand, pressed him
to become prime-minister, and when he declined named his friend
Martinez de la Rosa whom Toreno had recommended. Finally, when
the second French invasion had re-established the absolute king,
Toreno found himself again a banished man, in favour with neither
party, and this time his exile lasted nearly ten years. Most of it was
passed in France and England, some in Germany and Switzerland, in
the execution of a plan he had conceived of writing the history of
the war of independence, for which he had begun collecting materials
during his first emigration. He commenced the composition in 1827
at Paris, and finished the tenth book in the same city on the qight of
the 28th of July 1830, in the midst of the insurrection which raged
around.
The amnesty of 1832 restored him to Spain, but he was not per-
mitted to reside in Madrid till after the death of King Ferdinand. In
1834, on the promulgation of the ' Estatute Real ' by Queen Christina,
on the recommendation of his friend Martinez de la Rosa, he was
named minister of finance. The measures he proposed for liquidating
the foreign debt occupied his attention almost exclusively for some
time, and prevented his sharing the unpopularity of his chief, so that,
when in 1835 Martinez de la Rosa was compelled to retire, Toreno
succeeded to his place as minister of foreign affairs and president of
the council. Unfortunately for himself he admitted to his own post
of minister of finance Mendizabal, who, with his dazzling schemes,
soon threw him into the shade. Toreno, who was now decidedly a
" Moderado," grew more and more unpopular ; insurrections burst
forth, which he wished to repress by forcible means, but his colleague
thwarted him, and the country was not with him. In September
1835 he was driven to resign, and Mendizabal succeeded as head of
the cabinet. On a dissolution of the Cortes, Mendizabal was returned
by the electors of seven different places, and Toreno and Martinez de
la Rosa were left without a seat. The disgraceful revolution of La
Granja followed, the constitution of 1812 was proclaimed, and Toreno,
now its declared opponent, found it expedient to resume his historical
studies in Paris and London, where he brought bis history to a con-
clusion, at the time that in Madrid he was sentenced to forfeit all his
honours and estates. In a few months however he was again allowed
to return to Spain, and in the Cortes of subsequent years he vindicated
his character against an accusation of corruption brought against him
by General Seoaue. The revolution of Barcelona drove him into
banishment yet another time, and it was the last. Toreno, after a
tour in Germany and Italy, was in Paris, on his return, it is said, to
Spain, when seized with a cerebral disease which carried him off in a
few days. He died at Paris on the 16th of September 1843 ; but his
remains were conveyed to his country and deposited in the church of
Toreno's ' Histoiy of the Insurrection, War, and Revolution of Spain'
(' Historia del Levantamiento Guerra y Revolucion de Espana '), is
the great Spanish work on that interesting subject. That it is a model
of Spanish composition is affirmed by the best critics of that country.
Its merits as a narrative are more liable to question, for there appears
a languor and general want of spirit in its details, which surprise the
reader who is aware that its author was not only an eye-witness of
many of the events he describes, but also an actor in some of them.
The editor of the edition of 1848, published after the author's death,
speaks of the " carefulness and preciseness" of the history "in which,"
he remarks, "the most insignificant French detachment is never men-
tioned without specifying the name of the chief who commanded it."
A merit of more importance which Toreno's history possesses is that
of a calm judicial tone, which favourably contrasts with the arrogant
impetuosity of some English historians of that memorable contest. On
the whole, it can only be considered like Southey's ' History of the
Peninsular War,' as a temporary substitute and a collection of mate-
rials for the great work on the subject, with which it may be hoped
that some future historian will enrich the literature of his country.
The * Historia del Levantamiento ' has been translated into French
and German, and a Spanish edition of it was printed by Baudry of
Paris in his collection of the Spanish classics. The best edition of it
is that published in four octavo volumes at Madrid in 1848, after the
author's death, with his additions and corrections.
TORFAEUS, or TORMO'DUS, the assumed literary names after
having been introduced to the learned world as a Latin author, of
Thormod Thorveson. Little or nothing is known about his early life.
He was born at Engoe, a small island on the southern coast of Iceland,
of poor parents, who however were in sufficiently good circumstances
to give him an outfit (for the institution, like all public schools in
Iceland, was a free-school) for the Latin school at Skalholdt, where
according to Iceland custom, he became a good classical scholar ; so
much so, that upon his arrival in Copenhagen, his choice and fluent
Latin surprised the professors there. In 1654 he was entered as a
free student at the university of Copenhagen, where he remained till
1657. In 1659 he was captured and made prisoner by a Swedish
privateer on his return from Christiansand in Norway. This circum-
stance appears to have given him some notoriety, for immediately after
him interpreter of Icelandic manuscripts, and a short time afterwards
sent him to Iceland for the purpose of collecting manuscripts, which
with the assistance of his warm friend and patron, Brynhjulf Swend-
eon, bishop of Skalholdt, he accomplished so well, that the collection
which he brought back, and which in still preserved in the Royal
Library in Copenhagen, is considered the best in the world for ancient
Scandinavian history and literature. The king gave him, shortly
after his return, as a reward for his zeal, and to enable him to pursue
bis studies, a small appointment at Stawanger in Norway. This
office however he resigned in 1667, upon being appointed keeper of
the king's collection of antiquities. He made soon afterwards another
voyage to Iceland, for the purpose of taking poss- ssion of some little
property, to which he had succeeded after the death of his father and
of his elder brother; and after his return the same year, he went to
Amsterdam for some literary purpose. During his voyage back ho
was shipwrecked at Skagen ; and on his journey by land to Copen-
hagen, he was insulted and attacked in a small town in Sealand by one
of his countrymen, whom, iu defending himself, he accidentally killed.
This circumstance caused great excitement. He surrendered himself
immediately, was tried, and sentenced to death. However by an
appeal to a superior court, and an " appellatio ad tronum," or appeal
to the throne, as it is termed in Danish jurisprudence, his sentence
was commuted into a fine, which he paid, and was released ; but as it
was impossible for the king to retain a man in his service with a
blemish on his reputation, he was dismissed, and lost his salary. Ho
then retired to a small farm in Norway, the property of his wife,
where he lived without any official employment till the year 1682,
when Christian V., having succeeded to the Danish throne, recalled
him, and appointed him royal historiographer, and an assessor in the
consistory, or board of education, with a salary sufficient to enable
him to live independently and to pursue his studies. This appoint-
ment he kept till his death. He commenced his most important work
the ' History of Norway,' and finished it as far as the Union of Calmar,
when, unfortunately, ill health compelled him to surrender his favourite
task to his fiiend Professor Reitzer, He was married twice : his first
wife died in 1695 : he married again in 1709 ; and in 1719 he died,
very far advanced in years, without issue. His works, printed, as
well as in manuscript, are very numerous, and exhibit deep know-
ledge and indefatigable research into ancient Scandinavian history.
The manuscripts he left are preserved at the Royal Library in Copen-
hagen : as to his published works, it will be sufficient to mention the
most important, which are : — ' Historia Rerum Orcadensium, libri iii.,'
fol., Hafniae, 1715; 'Series Dynastarum et Regum Danife h, Skialdo
ad Gormum Grandovem,' 4to, Hafnigo, 1712 ; ' Histona Rerum Norve-
gicarum ad Annum 1387,' 4 vols, fol., Hafniaj, 1711. A very accurate
account of his later works, together with a collection of private letters,
which show at least that he wrote elegant Latin, is to be found in a
work publLshed by the celebrated Danish historian Peter Suhm, under
the title, ' In Effigiem Thormodi Torfaei, una cum Torfaeanis,' &c.,
126
TORINUS, ALB ANUS.
TORRENTIUS, LiEVINQS.
126
4to, Hafuiro, 1777. (Peter Snhm, Smaae Skrifter og Afhandlinger,
KiobeuhavD, 1788; Kber, JJibliograpJiisches Lexicon, Leipzig, 1819;
AUycmeines Ilistorisches Lexicon, Leipzig, 1747.)
TOKl'NUS, ALBA'NUS, the Latinised uame of Alban Tuorer, a
Swiss physician, who was born in 1489 at Winterthur, in the canton of
Zurich. He studied polite literature at Basel with zeal and assiduity,
and, after teaching rhetoric for some years, he at last determined on
taking the degree of Doctor of Medicine at Montpellier. Upon his
medicine, and soon acquired an extensive practice. He died February
23, 1550, at the age of sixty-one. Like several of his contemporaries,
he employed himself in translating the works of the Greek medical
writers into Latin, of which he published the following : — ' Polybi
Opuscula aliquot nunc primum o Grseco in Latinum conversa nempe
de Tuenda Valetudiue, sive de Ratione Victus Sanoruiu lib. i., De
Seminis llumani Natura lib. i., De Morbis, sive Affectibus Corporis
libri ii.,' 4to, Basil., 1544. Alexander Tralliauus, Lat., folio, Basil.,
1538. The first Latin ti-anslation of Paulus iEgineta, folio, Basil.,
1532, which was afterwards improved and several times reprinted.
This translation was severely criticised by Wiuther of Andernach
(• Guinterus Andernacus'), which drew from Thorer a very angry aud
somewhat abusive answer entitled ' Epistola Apologetica, qua Calom-
uias Impudentis&imas refellit,' 8vo, Basil., 1539. The first Latin trans-
lation of two works of Theophilus Protospatharius, with the title,
'Philareti de Pulsuum Scientia Libellus, item Theophili de Exacta
Retrimentorum Vesica) Coguitione Commentariolus,' &c., 8vo, Basil.,
1563. In his translation of Theophilus 'De Urinis,' he is charged by
Guidot (Not. in Theoph. ' De Urin.,' p. 234 ; et ' Alloq. ad Lect'.) with
having altogether omitted the pious epilogue to the work, and with
having altered two other passages (in the Preface, and in cap. 8) so as
to destroy the acknowledgment of our Lord's Divinity contained in
them. Fabricius mentions also (' Biblioth. Graca,' vol. xiii., p. 44, ed.
Vet.) a translation of 'J'heophilus's' Commentary on the Aphorisms of
Hippocrates,' but this is probably a mistake. (See Fabric, 'Biblioth.
Graoca,' vol. xii., p. 649, ed. Vet.; Choulant, 'Handbuch der Biicher-
kunde fiir die Aeltere Medicin.') He also retouched the old Latin
translation of Yahia Ibn Serapion Ben Ibrahim [Serapion], and pub-
lished it with the title ' Jani Damasceui Therapeuticse Methodi libri
vii., partim Albano Torino, partim Gerardo Cremonensi Metaphraste,'
folio, Basil., 1543. He published a Greek edition, in one volume, of
several of Hippocrates's works, viz., ' Prognose.,' ' De Nat. Horn.,'
'De Loc. in Hom.,' 'Jusjur.,' 8vo, Basil., 1636, and prefixed a Life of
the author. He inserted a Latin translation of the Letter of Diodes
Carystius to King Antiochus, •* De Secunda Valetudine Tuenda,' in the
second edition of his translation of Alexander Trallianus, folio, Basil.,
1541. He also edited a collection of medical works with the following
title : — 'De Re Medica huic Volumini insunt, Sorani Ephesii Peripate-
tici in Artem Medeudi Isagoge hactenus non visa. Oribasii Sardiani
Fragmentum de Victus Ratione, quolibeb Anni Tempore Utili, autea
nuuquam editum. C. Plinii Secuudi de Re Medica libri v. accuratius
Recogniti, eb Nothis ac Pseudepigraphis Semotis, ab Innumeris Min-
darum Millibus Fide Vetustissimi Codicis Repurgati. Lc. Apuleji
Madauren^is, Philosophi Platonici, de Herbarum Virtutibus Historia.
Accessit his Libellus Utilissimus de Betonica, quern quidam Antonio
Musce, nonnuUi Lc. Apulejo adscribendum autumant, nuper Excusus,'
folio, Basil., 1525. Besides these medical works he edited also Apicius,
'De Re Culinaria,' 4to, Basil., 1541 ; S. Epiphanius, 'De Prophetarum
Vitis,' 4to, Basil.,, 1529; Agapeti 'Scheda Regia,' Lat., 8vo, Basil.,
1541, at the end of Onosandri ' Strategicus ; ' and Emmanuel Chryso-
loraj, 'Epitome GrammaticesGrsecaj.' (See Fabric, Bihliotheca Qrceca,
vol. xiii., p. 44, ed vet. ; Biogr. Med. ; Choulant, Handh. der Bilcher-
Tcuvdefiir die Aeltere Medicin.)
TORPORLEY, NATHANIEL, was born about 1573, was entered at
Christchurch, Oxford, and after taking his degree was in France for
several years. Wood says it is notorious that during that time he
was amanuensis to the celebrated mathematician Francis Vieta. This
fact has been mentioned by the French historians, in speaking of
Harriot, when hard pressed to defend Des Cartes from the imputation
of being Harriot's plagiarist ; and the idea seems to be that as Tor-
porley was afterwards under the patronage and in the house of Henry
Percy, earl of Northumberland, as also were Harriot and others, he
must have been in habits of intimate communication with Harriot, to
whom he might have taught what he learnt from Vieta. With regard
to the fact itself, it is almost certain, for not only does Wood mention
it as notorious, but Sherburne, in the list at the end of his ' Manilius '
(1675), published before Wood wrote, says that Torporhy was " some-
time amanuensis to the famous Vieta." Nothing is more likely than
that Harriot learnt from Torporley many ideas of Vieta; but Harriot's
discoveries in algebra most distinctly bear the mark of a new mind.
Torporley afterwards wrote his 'Diclides CoelometricEe, seu Valva3
Universales,' &c., London, 1602, aud other works which we have never
seen. Wood also says he wrote something against Vieta, under the
name of Poulterey, a transposition (not, perfect however) of his own
name, but which he (Wood) had never seen. In looking through the
' Diclides,' &c., which is mostly on spherical trigonometry, we only
found two very slight notices of Vieta's name, which looks as if there
had been a coolness between them ; but we found, to our surprise,
that Torporley had preceded Napier by twelve years in the publication
of the greater part of the rule of Circular Parts, not indeed in Napier's
convenient form, but with a complete reduction of the six cases to
two, and rules, such as they were, by which to assimilate the con-
nected cases. For more account of Torporley 's process, which is the
greatest burlesque on mnemonics we ever saw, we refer to the
' Philosophical Magazine ' for May, 1843. We have only to add that
Torporley obtained church preferment, was a member of Sion College
(to which he left his books and manuscripts), and died in April,
1632. In the Catalogue of Sion Library it is said he was a chemist
who left a large number of chemical and other books ; but wo cannot
find one of his works in the second catalogue, aud we have not bad the
opportunity of examining the first. The firo of London occurred
between the publication of the two, and the books which were then
consumed are not mentioned in the second.
TORRE, FILIPPO DEf., born at Cividale in the Friuli, in 1657,
studied at Padua, and afterwards went to Rome in 1687, where he
was employed in several offices, and at last was appointed bishop of
Adria by Clement XL, in 1702. He died in 1717. While at Rome he
published a work of great research on the antiquities of Antium,
' Monumenta veteris Antii,' which was much esteemed by the learned.
He wrote some other works in illustration of ancient medals, and
also upon subjects of natural history. Qirolamo Lioni wrote a
biography of Filippo del Torre.
TORRE, FILOMARI'NO, DUKE DELLA, a Neapolitan noble-
man who lived in the second half of the 18th century, and applied
himself strenuously to the study of physics. His name is known in
history chiefly for hid melancholy end. In the first insurrection of
the populace of Naples, who, being forsaken by the king and court
and all the principal authorities on the advance of the French invad-
ing armj', rose tumultuously in January 1799 to defend the town
and at the same time to destroy those whom they suspected of being
favourably inclined towards the French, the Duke della Torre, who
lived in great retirement and does not appear to have meddled with
politics, was denounced to the popular committee by a menial who
had seen a letter written to the duke by a noble relative of his at
Rome, informing him that he had recommended him to the French
general for protection in the event of Naples being stormed by the
French army. This was suflicient to persuade the ignorant lazzaroni
that the duke was a secret Jacobin, and his doom was fixed at once.
The mob went to his palace, pillaged it, destroyed his library, his
collection of natural history, and his cabinet of physics, threw the
furniture out of the window, seized the duke and his brother the
Cavaliere Clemente Filomarino, known for his poetical talent, and
dragged them to the Marina of the Carmine, where they killed both of
them. At the same time it must be observed that the leaders of the
mob showed some regard for the women aud children ; they ordered
one of the duke's carriages out, put the duke's wife and her children in
it, aud told them to drive to some friend's or relative's, after which
they set fire to the palace. The two brothers Filomarino were the
most distinguished victims of the first or Lazzaroni insurrection of
1799. (CoUetta, Storia del Reame di Napoli; Cuoco, Saggio Storico
sidla Rivoluzione di Napoli; Sketches of Popular Ttimidts, 1837.)
TORRE, GIAMMARFA DELLA, was born at Rome of a Genoese
family, at the beginning of the 18th century. After studying in the
college Nazareno, he entered the order of the Somaschi, and having
shown great aptitude for physical and mathematical studies, was suc-
cessively professor in several colleges at Rome, Venice, and Naples.
At Naples he became known to King Charles V. of Naples (afterwards
Charles III. of Spain), who employed him in several scientific experi-
ments, and made him his head librarian and keeper of the Museum of
Capo di Monte. He published a history of Vesuvius, ' Storia e Feno-
meni del Vesuvio esposti dal P. Gio. Maria della Torre, Somasco,' foL,
Naples, 1755. He also wrote a ' Course of Physics,' in Italian and
Latin, which has gone through several editions ; a volume of micro-
scopical observations, and numerous memoirs on scientific subjects.
He applied himself particularly to improve the microscope. He also
contributed to illustrate the newly discovered towns of Herculaneum
and Pompeii. He was one of the most distinguished members of the
Academy of Sciences of Naples, and was also corresponding member
of the Academies of Sciences of Paris and Berlin, and of the Royal
Society of London. Father della Torre died at a very advanced age,
in March 1782. (Lombard!, Storia della Letteratura Italiana nel
Secolo X VIII.)
TORRE'NTIUS, L^VI'NUS, whose original name was Van der
Beken, was born at Ghent in 1525. He studied at Louvain, and was
in the town when it was besieged by the celebrated Martin van
Rossem. To commemorate the successful defence of the inhabitants,
Torrentius composed a Latin poem, which was highly thought of at
the time. He subsequently travelled to Italy, and spent some time at
Bologna; at Rome however he remained many years, and studied
Roman antiquities there with great diligence. He enjoyed the friend-
ship of the Cardinal Baronius, Antonius Augustinus, Fulvius Ursinus,
and other celebrated scholars during his residence at Rome ; and he
also made there a fine collection of ancient coins and works of art.
various ecclesiastical dignities, and was at length appointed to the
bishopric of Antwerp, where he laboured with great zeal in discharging
the duties of his office. He is eaid to have been also e mployed in
127
TORRICELLI, EVANQELTSTA.
TORRIGIANO, PIETRO.
128
various embassies and political negociations. In 1595 he was appointed
Archbishop of Mecbliu, but before the documents arrived from Rome
which were necessary to enable him to enter upon his now dignity, he
died at Brussels in the seventieth year of his age. He was buried in
the cathedral-church of Antwerp. He left his library and collection
of antiquities to the college of Jesuits at Louvain.
Torrentius was an accurate scholar, and well acquainted with
Roman antiquities, but he did not write much. The only work of
his which was published in his lifetime is a Commentary on Suetonius,
which originally appeared at Antwerp in 1578, and was reprinted in
1592 : it is also contained in Grasvius's edition, published in 1G72.
This Commentary is also interesting from the many wood-cuts it con-
tains, representing coins of the Roman emperors and their families.
Torrentius's Commentary on Horace was not published till after his
death : it appeared at Antwerp in 1608, 4to, together with a small
treatise of his entitled ' Commentariolus ad Legem Juliam et Papiam
de Matrimoniis Ordinaudis.' Besides these Commentaries, Torrentius
also published in his lifetime several Latin poems, of which a collec-
tion appeared at Antwerp in 1576, 8vo, under the title of Poemata
Sacra.* Torrentius was called by his contemporaries the Christian
Horace ; and his poems ai-e distinguished by great ease of versifica-
tion. He also edited the posthumous works of J. Goropius Becanus,
Antwerp, 1580, with an apology for Becanus, who had been attacked
by Scaliger. (Foppens, Bibliotheca Belgica; Saxii, Onomasticon.)
TORRICELLI, EVANGELISTA, a learned Italian mathematician
and philosopher, was born October 15, 1608, at Piancaldoli in
Romagna, and being, probably at an early age, an orphan, he was
supported by an uncle who resided at Faecza. At this place, and in a
school of the Jesuits, the youth received a mathematical education,
and he speedily distinguished himself by the progress which he made
in acquiring a knowledge of the sciences.
At twenty years of age his uncle sent him to Rome where he
became intimately acquainted with Benedict Castelli, who was then
professor of mathematics in that city, and by whom his studies were
directed. The Dialogues of Galileo appear to have particularly
engaged Torricelli's attention, and he composed two tracts, one on the
subject of mechanics, and the other on the motion of fluids, which
were published with the rest of his mathematical works in 1643.
Torricelli seems to have been the fii-st who established the principle,
that when two weights are so connected together, that being placed in
any position their common centre of gravity neithcT ascends nor
descends, those weights are in equilibrio ; and on this principle he
investigated the ratio between two weights when they are in equilibrio
on a double inclined plane. He also investigated the motions of
falling bodies and projectiles ; and among the results of his researches
is the remarkable fact, that the paths of any number of projectiles
(in a non-resisting medium) when discharged from the same point
with equal velocities, but at different angles of elevation, are parabolas
situated within one curve which is a tangent to all of them, and is
itself a parabola. In the tract on the motion of fluids he assumes
that water will flow through an orifice at the bottom of a vessel with
a velocity equal to that which woiild be acquired by a body falling
through the height of the fluid in the vessel, and he endeavours to
establish the principle by the supposed fact that water so flowing
ascends in a vertical tube connected with the vessel at the orifice (the
resistance of the air being abstracted) to the level of the upper
surface of that which is in the vessel : he hence concludes that the
velocities of effluent water must vary with the square-roots of the
pressures.
Galileo, having received copies of the tracts above mentioned, was
desirous of becoming acquainted with the author, and he pressed the
latter to join him at Florence. Torricelli, having formed connections
at Rome, at first hesitated, but at length decided to accept the invita-
tion : he was kindly received by Galileo, and it is said that his society
and conversation contributed to soothe the last days of the venerable
philosopher, who was then infirm and blind, and who died at the end
of three months from his arrival. Having been honoured by the
grand-duke with the appointment of professor of mathematics in the
Accademia, Torricelli became the successor of Galileo in the institution,
and he resided at Florence till his death, which happened in 1647,
when he was thirty-nine years of age.
About the year 1637 Roberval, in Franco, discovered a method of
determining the area of a cycloid, and seven years later Torricelli
published a solution of the problem in an appendix to the collection
of his works. As the Italian mathematician appeared to consider
himself to be the discoverer of the rule, Roberval's jealousy was
excited, and he accused Torricelli of plagiarism ; asserting that the
latter had taken the solution from some papers which had been sent
to Galileo, and which had fallen into his hands on the death of that
philosopher : Torricelli however, in a letter to Roberval, denies that
assertion, and there seems no reason to doubt that he made the
France. He subsequently gave rules for finding the volumes of the
solids formed by the revolution of a cycloid about its base and about
its axis ; that which is applicable to the first case is correct, but the
other is only approximate, so that it may be doubted whether or not
Torricelli was in possession of an accurate solution of the problem.
But the discovery which has immortalised the name of Torricelli is
that of the barometer. Galileo had occasion, some time previously, to
observe that a column of water exceeding 18 cubits (about 33 feet,
Engli.sh) in height could not be raised in a pump ; and, though he had
reason why that limit could not be exceeded remained unknown to
him. Torricelli, in 1643, wishing to find, in a more convenient
manner, the weight of the quantity of fluid which could be supported
above its general level, performed an expeiiment similar to that which
is exhibited when a pump is in action; and, instead of water, he used
mercury, which is about fourteen times as heavy. He filled with
mercury a glass tube which at one end was hermetically closed, and
having inverted it, he brought its open extremity under the surface of
mercury in a vessel ; when he observed that the top of the column
descended till it stood at a height equal to between 29 and 30 inches
(English) above the level of the mercury in the vessel, leaving what ia
considered as a perfect vacuum between the upper extremity of the
column and that of the tube. The specific gravity of mercury being
known, the weight of the supported column could, of course, be found.
By this experiment the opinion that a vacuum was contrary to a
law of nature was immediately proved to be unfounded, but it is
uncertain whether or not Torricelli was aware of the true cause of the
column of mercury being so supported, and the honour of having been
the first to prove decisively that it was the piessure of the atmosphere
on the surface of the mercury in the vessel, is ascribed to Pascal, who,
in 1648, on conveying a tube so filled to stations at different heights
above the level of the plains, found that the column of mercury dimi-
nished in length as the statiou was more elevated ; that is, as the
weight of the column of atmosphere above the vessel diminished.
It may be easily conceived that Torricelli would communicate his
ideas to his friends before he actually made the experiment above men-
tioued ; and such a circumstance may account for the pretensions of
Valerianus Magnus, Honoratus Fabri, and others, to priority in the dis-
covery of what is called the Torricellian vacuum. It ought to be
observed however that in one of the letters of Descartes, dated 1631,
that is, twelve years before the experiment of Tori'icelli was made,
this philosopher mentions the support of a column of mercury in a
tube, and expressly ascribes the cause to the weight of a column of
air extending upwai'ds beyond the clouds.
Torricelli published at Florence, in 1644, a volume in 4to, entitled
' Opera Geometrica.' A paper which he wrote on the course of the
Chiana is in the collection of writings on the movement of fluids
(Florence, 1768). His discovery of the barometer is given in his own
work on mathematical and physical subjects, entitled ' Ldzione Acca-
demiche' (Florence, 1715). And his letter to Roberval on the cycloid
is in the third volume of the ' M cmoires ' of the Academy of Sciences at
Paris. He is said to have been the inventor of the small simple micro-
scopes of short focus, which consist of a globule of glass melted in the
flame of a lamp. His manuscripts are preserved in the Medicean
Palace, and in the same edifice there are some object-glasses for
telescopes, of considerable dimensions, which bear his name.
TOKRIGIA'NO, PIE'TRO, an Italian sculptor, whose name is con-
nected with the history of art in this country, he being one of the
foreign artists employed by Henry VIII., was hardly less remarkable
for the ferociousness of his tempei", the singularity of his conduct, and
the strangeness of his fate, than for his ability in his profession. He was
a native of Florence, and though the time of his birth is not mentioned,
it was probably about the same as that of Michel Angelo (1474), as they
studied together from the antiquities in the gardens of Lorenzo do'
Medici, il Magnifico ; a circumstance which Michel had good cause to
remember, for such was Torrigiano's jealousy of and spite towards him,
that he one day assaulted him, and inflicted so severe a blow upon his
nose as to crush and disfigure it for ever. Being obliged to leave
Florence in consequence of this affair, Torrigiano went to Rome, where
he was employed by Pope Alexander VI., and afterwards enlisted and
served as a soldier, first under the Duke Valentino in Romagna, next
under Vitelli and Piero de' Medici. Strange as this change was, he was
well suited to his new profession, and that to him ; for, as described both
by Vasari and Cellini, he was a large, handsome, and powerful man ;
was gifted with great "audacity, and had more the air of a rough
soldier than of an artist." But though he distinguished himself by his
prowess, and obtained the rank of ensign, he saw no chance of speedily
advancing higher, and therefore returned to his former profession,
which he practised for awhile, but only, it would seem, in small
bronze figures, executed for some Florentine merchants, whom he
afterwards accompanied to England. His talents, and perhaps his
personal qualities also, recommended him to the favour of Henry VIII.,
for whom he executed a variety of things, but his chief work was the
tomb of Henry VII. in Westminster Abbey, which he completed in
1519, and for which he received the sum of 1000/. The tomb of
Margaret, countess of Richmond, in Henry VII.'s chapel, is also
supposed to have been by him.
While engaged upon Henry's tomb he returned to Italy, in order to
carry back with him other assistants, and endeavoured to persuade
Benvenuto Cellini, then only eighteen, to accompany him ; but the
latter tells us he was so disgusted with Torrigiano, on learning from
him how brutally he had treated Michel Angelo, that so far from
associating with him in any way, he could not even endure the sight
of him.
129
TORRIJOS, JOS^ MARIA.
TOTT, BARON DE.
130
After finally quitting England in 1519, Torrigiano visited Spain,
where he executed several pieces of sculpture for convents, &c,, and
among others a Virgin and Child, so beautiful that the Duke d'Arcos
commissioned bim to make a copy of it. The payment promised for
it seemed such an immense sum, that the artist fancied he was about
to be rendered wealthy for the rest of his days ; so great therefore
was his indignation on discovering that the vast heap of maravedis
sent home to him amounted to no more in value than thirty ducats,
that he went and broke the statue to pieces. On this, the duke
caused him to be imprisoned in the Inquisition as a sacrilegious
heretic who had impiously destroyed a figure of the Holy Virgin. He
was accordingly condemned by that tribunal, but avoided the execu-
tion of his sentence by refusing to take any food ; preferring starving
himself to death to the more ignominious end which else awaited him.
Thus perished, in 1522, an artist of more than ordinary talent: a
Tictim partly to his own violence and imprudence, and partly to the
mercilessness of a most odious and sanguinary tribunal.
TORRIJOS, JOSli; MARIA, a Spanish general and patriot, was
born at Madrid on the 20th of May 1791, and at the age of ten was
made one of the pages of King Charles IV., a position which brought
him into familiar contact with the young prince, who afterwards
became King Ferdinand VII. It was the custom for the royal pages
to receive early rank in the army, and Torrijos at the age of sixteen
was a captain in the regiment of Ultonia or Ulster in the Irish brigade
in the service of Spain. On the great outbreak of the 2nd of May
1808, and in the subsequent war of independence, Torrijos distin-
guished himself by his bravery; in 1811 he was already colonel of a
regiment, he took part in the battle of Vittoria, and at the conclusion
of the war he was general of brigade. His early acquaintance with
the court had strengthened his aspirations for liberty, he declined the
command of a force under Morilla against the South-American insur-
gents, and in 1817 was thrown into the prison of the Inquisition on a
charge of conspiracy against the government. The constitutional
outbreak of 1820 liberated him, and as Captain General of Valencia
he was ardent in his services to the the constitutional cause. After the
French invasion of 1823 he took refuge in England, for which country
he always manifested a strong partiality. He partly employed him-
self in translating books into Spanish for the South- American market,
among others the ' Memoirs of General Miller,' an Englishman who
had been in the. Peruvian service. The French revolution of 1830
awakened his hopes for a speedy change in Spain and he set off for
Gibraltar to take the lead. Moreno, the governor of Malaga, treacher-
ously enticed him to a landing by false intelligence and promises of
support, and he left Gibraltar, at the head of a party of fifty, on the
30th November 1831, with full confidence of success. On the 5th of
December the whole of the party were taken prisoners by Moreno,
who sent to Madrid for orders how to act. It was till then believed
that King Ferdinand had a special kindness for Torrijos, whom he had
known so long, but the only reply received was in the laconic form
" Que los fusilen. Yo el Rey," (" Let them be shot. I the King.")
Torrijos and his companions, fifty-one in number, were accordingly
shot at Malaga on the 11th of December. The subsequent death of
Ferdinand changed the whole face of affairs, a little more patience
would have brought Torrijos peaceably back to Spain, with his friends
in power, and the infamous treachery of Moreno ruined his own
career. Queen Christina, the widow of Ferdinand, ennobled the
widow of Torrijos with the title of countess, and his bust was erected
at Madrid at the house in which he was born in the Calle de
TORTI, FRANCIS, an eminent Italian physician, was born at
Modena, December 1st 1658. Having finished his preliminary studies
in 1675, he was originally intended for the legal profession; this
however he soon abandoned, and embraced that of medicine, which
he studied under Antonio Frassoni. He took the degree of Doctor
of Medicine at Bologna in 1678, and upon his return to Modena, at
the early age of twenty-three, he obtained one of the medical pro-
fessorships founded by the Duke Frauds II. Soon afterwards he was
chosen to be one of the physicians in ordinary to the duke, an appoint-
ment which he owed partly to his accomplishments in music and
literature, as he was the composer of several oi-atorios, and also wrote
a Latin letter under the assumed name of L. A. Cotta, in defence of
Tasso against Bouhours. Upon the death of Francis in 1694, his suc-
cessor continued Torti in his place of physician in ordinary ; he was
also prevailed upon by his representations to found an anatomical
amphitheatre at Modena, in which Torti was entrusted with the oflBce
of demonstrator in 1698. He had previously joined with Ramazzini
in carrying on some researches concerning the barometer, the results
of which were published by the latter under the title ' Ephemerides
BarometricEc Mutinenses.' Modena, 1694 ; and again 'Dissertatio altera
Triceps circh, Mercurii Motiones in Barometro,' Modena, 1698. But
Torti's most important and celebrated work did not appear till 1709,
under the title ' Therapeutice Specialis ad Febres quasdam Perniciosas,
inopinato ac repente Lethales, una ver5 China China Peculiari Methodo
ministrata,' 8vo, Modena. This work placed him at once in the first
rank among practical physicians, and still continues to be highly
esteemed. It has been several times reprinted. The publication of
this work gained him the friendship and applause of various learned
men, and also the title of corresponding member of the Royal Society
BIOG. DIY. VOL. YI.
of London, and of the Academy of Valentia in Spain. It also drew
forth some criticisms from Manget and Ramazzini, to whose remarks
he replied with some degree of bitterness and warmth. In 1717 he
was offered the professorship of Practical Medicine at Turin, and in
1720 he had a shnilar offer at Padua, but he refused them both, and
preferred living at Modena, where he had honours and emoluments
heaped upon him by the duke. An incurable trembling of the hands
having rendered him unable to feel the pulse of his patients with
sufficient accuracy, he gave up practice some years before his death,
and passed the remainder of his life in honourable repose, often con-
sulted by patients from all parts, and spending much of his leisure
time in the pleasures of the chase, to which he had always been much
addicted. Having been summoned by the Prince of Parma, in 1731,
to attend Henrietta d'Este, he was, upon his return to Modena, seized
while in a church with a sudden attack of hemiplegia, brought on
probably by heat and over-exertion. For some time afterwards he
lost the use of his right side, but gradually recovered, and lived for
ten years after the attack. He latterly became dropsical, and died in
March 1741, at the age of eighty-two. He was twice married, but
having no children, he left part of his fortune to found another
medical professorship at Modena, and directed the rest to be given
away in charity.
TOTT, FRANCOIS BARON DE, the son of an Hungarian nobleman,
who, obliged to leave his country in consequence of his connections
with Prince Rogotzky, had entered the French service, was bom at
ITerte-sous-Jouarre, on the 17th of August 1733. Young De Tott
obtained at an early age a commission in the hussar regiment of
Berchiny, which his father had been instrumental in raising and
disciplining. In 1755 the senior De Tott, who spoke the Turkish and
Polish languages fluently, and had been more than once employed in
missions to the Crimea, was appointed to accompany M. de Vergennes
to Constantinople. He took his son with him, intending that he
should study the language and render himself familiar with the
manners of the Turks. The father died of a fever in September of
the year 1757, but M. de Vergennes conferred upon the son an
appointment in the embassy, which he continued to hold along with
his commission in the regiment of Berchiny. De Tott remained at
Constantinople till 1763, when he returned to France.
In 1766 the Baron de Tott presented a memorial to the Due de
Choiseul, pointing out the means of concluding a treaty of commerce
with the Khan of the Crimea, and extending the commerce of France
in the Black Sea. The French consul in the Crimea dying about the
same time, the Due de Choiseul appointed the memorialist his suc-
cessor. De Tott repaired to his post by the way of Poland. He does
not appear to have done anythiug towards realising his projects for
placing the commercial intercourse of France with the Crimea on a
better footing ; but he contrived to involve himself so deeply in the
intrigues of the court, that the vizir sought and obtained his removal
by the French government in 1769.
The Baron de Tott returned to Constantinople, entered the service
of the Ottoman Porte, and continued in it till the year 1776. If his
own account may be believed, he was during that period one of the
moving spirits of the Ottoman empire. He presented the sultan with
a map of the theatre of war between the Turks and Russians imme-
diately after his arrival at Constantinople ; and suggested the advance
of the Pasha of Bender into the Ukrain. He proposed an entire reform
in the Turkish artillery, and was appointed to carry it into effect. In
1770 he was charged with the defence of the Dardanelles, menaced by
the Russian fleet. In 1771 he devised a plan of defence for the
Turkish frontiers towards Oczakow; taught the Turkish artillerists
to make bombs, and brought them to an unprecedented dexterity in
working their guns. In 1772 he organised a new cannon- foundry. In
1773 he gave directions for the fortification of the Black Sea mouth
of the Bosporus. In 1773, 1774, and 1775 he was busy improving
the fortifications and artillery of the Turks. All these statements
have some foundation in fact; but the tone of exaggeration which
pervades all the baron's account of his own exploits rendera it im-
possible to decide how much of them is to be believed. It is evident
that he did not think his services sufficiently appreciated, for in 1776
he tendered his resignation in disgust ; and it is equally evident that
they were not so highly esteemed by the Turks as by himself, for the
re^ignation was readily accepted, and the baron dismissed with some
cold compliments.
He was despatched by the French government in 1777 on a tour
of inspection of the consular establishments in the ports of the Medi-
terranean from the Archipelago to the Barbary States. At the request
of Buffon, Sonnini was allowed to accompany the expedition.
With this mission the diplomatic services of the Baron de Tott
upon him, one from the ministry of the marine, the other from that
of foreign affairs, and, retiring from public life, occupied himself with
preparing for the press the observations made during upwards of
twenty years of active life. The work appeared in 1784 under the
title ' Mdmoires sur les Turcs et Tartares.' It met with great success :
the original French version was frequently reprinted, and translations
of it into English, German, Dutch, and Swedish appeared in the
course of a few years.
De Tott was raised to the rank of Marechal-de-Camp in 1781. In
K
181
TOULMIN, JOSHUA, D.D.
TOUR, MAURICE QUENTIN DE LA.
133
1786 or 1787 ho was appointed governor of Douai. He Leld that
office till 1790, but opposiug liimBelf to the republican fervour of the
parrison, was nearly murdered and obliged to fly. He took refuge in
Switzerland, where he resided for a year, and then proceeded to
Vienna. He died in obscurity at Tatzmansdorf in Hungary, in 1793.
TOULMIN, JOSHUA, D.D., was born in London, on the 11th
of May 1740, and was educated at St. Paul's school, whence he was
removed to what was then called the Dissenting Academy, the classes
constituting which were taught in Wellclose Square, in the house of
his relation Dr. Samuel Morton Savage, who was the classical and
mathematical tutor; the only other teacher being Dr. David Jen-
nings, who was theological tutor or professor, and presided over the
seminary. (' History of Dissenters,' by Bogue and Bennett, iv. 261,
262.) On being licensed to preach, he was in the first instance settled
as minister of a dissenting congregation at Colyton in Devonshire. At
this time his principles appear to have been what are commonly called
orthodox; but he soon became a convert to the opinions of the
Baptists; upon which, in 1765, he transferred himself to Taunton,
where, besides having the charge of a Baptist congregation, he taught
a school, and also, it is said, kept a bookseller's shop. It was while
resident here likewise that he wrote and published most of the literary
works which have made his name known. He had not been long at
Taunton before his theology underwent a further change; but,
both of Gloucester and Yarmouth, he remained where he was till 1804,
when he accepted the situation of one of the pastors of the Unitarian
congregation at Birmingham, formerly presided over by Dr. Priestley,
and then assembling in what was called the New Meeting-House.
This appointment he continued to hold, discharging its duties with
much acceptance, till his death at Birmingham, after a sliort illness,
on the 23rd of July 1815, leaving five children, out of a family of
twelve, by his wife Jane, youngest daughter of Mr, J. Smith, of
Taunton, whom he married in 1764.
Dr. Toulmin received his diploma of D.D. from Harvard University,
in the United States, in 1794. His first publication appears to have
been an octavo volume, entitled * Sermons addressed to Youth, with a
Translation of Isocrates's Oration to Demonicus,' which appeared in
1770, and was reprinted in 1789 : this was followed by ' Two Letters
on the Address of the Dissenting Ministers on Subscription,' Svo,
1774 ; ' Memoirs of Socinus,' Svo, 1777 ; * Letters to Dr. John Sturges
on the Church Establishment,' Svo, 1782; 'Dissertations on the
Internal Evidences of Christianity,' 8vo, 1785; 'Essay on Baptism,'
Svo, 1786; a new edition (the third) of 'Mr. William Foot's Account
of the Ordinance of Baptism,' Svo, 1787; 'Review of the Life, Cha-
racter, and Writings of John Biddle, M.A.,' Svo, 1789; ' History of
the Town of Taunton,' 4to, 1791 ; a new edition of Neal's * History of
the Puritans,' with notes and additions, 5 vols. Svo, 1794-97, reprinted
in 3 vols. Svo, 1837; 'Biographical Tribute to the Memory of Dr.
Priestley,' Svo, 1804; 'Address to Young Men,' 12mo, 1804;
' Memoirs of the Rev. Samuel Bourne ' (his colleague at Birmingham),
Svo, 1809; 'Sermons on Devotional Subjects,' Svo, 1810; 'Historical
View of the State of the Protestant Dissenters in England,' Svo,
1814; besides a number of single sermons and other pamphlets : and
he was also an occasional contributor to the * Theological Repository,'
' The ^Nonconformists' Memorial,' ' The Monthly Magazine,' and other
periodical publications. Dr. Toulmin's writings, without much either
of learning or power of thought, display generally an agreeable per-
spicuity and neatness of style, rising sometimes to considerable energy
and animation ; and although steady, and even eager, in the defence of
his own opinions, he states what he has to say without any bitterness
or discourtesy to his opponents.
TOULONGEON, FRANCOIS E'MANUEL, VISCOUNT OF, a
French historian of the last and present century, was born in 1748, at
the castle of Champlitte, in La Franche Comtd, and belonged to one
of the oldest families in that province. He was destined by his
parents for the church, and was sent at an early age to the Seminary
of St. Sulpice at Paris ; but having evinced a decided repugnance to
theological studies, he was permitted to follow his own inclination,
and to enter the army. He was a great admirer of Voltaire, to whom,
in 1776, he paid a visit at Ferney, and whose favour he gained. He
was admitted a member of the Acaddmie of Besangon, in 1779, having
previously manifested a degree of poetical talent which gained for
him some local celebrity. He rose to the rank of colonel of chasseurs,
and his regiment was remarked for its discipline and good condition ;
but he quitted the service previous to the wars which arose out of the
French revolution. At the commencement of the revolution he
embraced the popular side, and defended it against the majority of
the nobles of La Franche Comtd in the assembly of the states of that
pamphlet, under the title of ' Principes Naturels et Constitutifs des
Assemblees Nationales,' which appears to have been his first publica-
tion. It gained him considerable popularity, and led to his appoint-
ment as one of the deputies of the nobility of the province in the
States-General of 1789. He was one of those nobles who separated
themselves from their order to unite with the tiers-4tat, or commons,
in one chamber, which assumed the title of the National Assembly,
• In the years 1790-91 he acted with the moderate revolutionists; and
at the close of the session, presaging the approaching troubles, he
quitted public life, and retired to an estate which he possessed in Le
Nivernais, the sole ramain of his patrimonial inheritance, and which
was considerably diminished in value by the loss of the feudal services
which had been suppressed by the revolution. His early retirement
preserved him from the perils of the reign of terror. His subsequent
life was devoted to literary and to agricultural pursuits. He was
elected a member of the Institute, in 1797, in the class of the moral
sciences (a class suppressed at the reorganisation of the Institute, in
1803) ; and, in the same year, brought out a periodical, entitled
' Esprit Public,' with the view of calming the violence of party spirit ;
but only six numbers of the work appeared. He was chosen, in 1802
and 1809, deputy for the department of Ni^^'re in the legislative body;
and was subsequently made a commander of the Legion of Honour.
He died suddenly, 23rd December 1812, and was buried in the ceme-
tery of Montmartre, where his children have raised a monument to
his memory.
The principal works of Toulongeon are: — 'Histoire de France
depuis la Rdvolution de 1789;' 'Manuel du Musdum Francis;'
' Manuel R6volutionnaire, ou Pensdes Morales sur I'Etat Politique des
Peuples en Rdvolution ; ' a poem, entitled ' Recherches Historiques
et Pbilosophiques sur 1' Amour et le Plaisir ; ' and a translation of
Cffisar's 'Commentaries.' He published some smaller works; and
some of his papers read at the Institute were published either in the
'Mdmoires de I'lnstitut,' or separately, by himself. His 'Histoire
de France ' never appears to have attained a high reputation, and has
been superseded by later histories of the s^pae period : but the exact-
ness of its military details gives it some value. The first edition was
without date, in 2 vols. Svo ; the second edition (1801-10) was pub-
lished in 4 vols. 4to, or 7 vols. Svo, with maps and plans of battles.
The ' Manuel du Museum' is a catalogue raisonnd of the paintings of
the ancient masters : it was published in ten thin volumes, Svo, 1802-
1808 : the first nine volumes have the initials of Toulongeon on the
title-pages; the tenth volume is by another hand. The 'Manuel
Revolutionnaire' (1795) went through two editions, and was trans-
lated into German. The translation of Coosar was published after
Toulongeon's decease, 2 vols. ISmo, 1813, with plans and military
notes on the text. A new edition, interpaged with the original text,
was published in 1826: part of a collection (by M. A. Pommier) of
the Latin classics, interpaged with French veraions.
TOUP, JONATHAN, was born at St. Ives in Cornwall, in December
1713, and was partly educated at a grammar-school in that town. He
was afterwards entered at Exeter College, Oxfoid, where he took his
bachelor's degree, but his master of arts degree he took at Cambridge.
Toup entered the Church, and obtained successively the rectory of
St. Martin's, Exeter, and a prebend's stall in Exeter cathedral. He
died on the 19th of January 1785, in his 72nd year, and was bm-ied in
St. Martin's church.
Toup was an accurate scholar, and one of the best English critics
in the middle of last century. The work by which he is best known
is his ' Emendations of Suidas ; ' the first volume of which was pub-
lished in 1760, under the title of ' Emendationes in Suidam, in quibus
plurima loca veterum Grsecornm, Sophoclis et Aristophanis imprimis,
cum explicantur tum emendantur.' This was followed by two volumes
more in 1764 and 1766, and by a fourth in 1775, under the title of
' Appeudiculum Notarum in Suidam.' This work gained for him the
friendship of Bishop Warburton, to whose influence Toup was mainly
indebted for his church preferment. In 1767 Toup published his
'Epistola Critica ad virum celeberrimum Gulielmum episcopum
Glocestriensem,' containing various corrections and explanations of
many passages in the Greek authors. Toup was also a large contri-
butor to the Oxford edition of Theocritus edited by Wharton, which
was published in 1770. A note of his upon the fourteenth Idyl wag
cancelled by the vice-chancellor on the ground of its indecency, prin-
cipally, it is said, at the wish of Dr. Lowth. Toup however was
highly displeased at this, and published the objectionable note in 1772
in his ' Curaj Posteriores, sive Appendicula Notarum atque emenda-
tionum in Theocritum, Oxonii nuperrime publicatum,' in which he
attacks the taste and the learning of those who had it omitted.
Toup's last work was an edition of Longinus, published at Oxford in
1778, and reprinted in 1789, which is still one of the best editions we
have of this writer. (Nichols's Bowyer.)
TOUR, MAURICE QUENTIN DE LA, an eminent French portrait
painter, was born at St. Quentin in 1704. De la Tour was distin-
guished for his portraits in ci'ayons, which he executed the sine of
life ; he painted very slowly and finished very highl}', but gave his
pictures the appearance of having been executed with great ease by
adding a few bold and effective touches to the already finished work.
He painted many portraits, and was much in fashion in the time of
Louis XV., with whom he was a favourite, and whose portrait he
painted. The following are among his best pictures : — a large full-
length of Madame de Pompadour ; the portrait of Louis, Dauphin of
France; one of Prince Charles, the Pretender; the portraits of
Restout, the king's painter, pi-esented to the Academy of Arts of
Paris in 1746, when De la Tour was elected a member of the Academy;
of Rend Fremin, the king's sculptor ; of J. B. S. Chardin, the painter ;
of the Marechal de Saxe, and others ; and his own portrait, which
was engraved by G. F. Schmidt in 1742.
De la Tour was a man of very eccentric habits, and towards the
133
TOURNEFORT, JOSEPH PITTON DE.
TOURNEFORT, JOSEPH PITTON DE.
184
end of his life he spoiled many of his works by painting out the
beautiful accessories which he had oiigiually introduced, upon the
principle that in portrait everything should be sacrificed to the head —
the portrait of llestout was one that suffered in this way ; he turned
his brilhant silk vest into one of simple brown stuff. He died in
1788, aged eighty-four. He gave 10,000 francs to the Academy of
Paris to found an annual prize of 500 francs for the best picture in
perspective, aiirial and linear alternately ; he gave also an equal anm
for the foundation of an annual prize for the most useful discovery for
the arts, to be awarded by the Academy of Amiens ; and he founded a
TOURNEFORT, JOSEPH PITTON UE, a celebrated botanist, was
born June 5, 1656, of a noble family at Aix, in Provence, in the
present department of Pouches du Rhone. Having a great taste for
observation, the study of nature soon disgusted him with scholastic
philosophy and theology, in which ho wjis engaged, in order to please
his relations, who wished him to enter holy orders. The death of his
father, in 1677, enabled him to follow his own inclination ; and having
exhausted the fields of his own country and the garden of an
apotliccary, he went to the Alps, iu order more fully to satisfy his
curiosity. At Montpellier, whither he had gone to study medicine,
and where he was received by Magnol, and became the friend of
Chirac, ho found fresh stores of information; and he collected still
richer from the Cdvennes, the Pyrenees, and from Catalonia, to which
places his zeal carried him. In these excursions he was twice robbed
by the Spanish miquelets (or foot soldiers), who left him nothing but
his plants ; he was buried also for two hours under the ruins of a hut
where he was passing the night; and thus he seemed to be inuring
himself to the fatigues he was one day to undergo in longer travels.
He was already possessed of rich collections and numerous observa-
tions, when he repaired to Paris, where Fagon, chief physician to the
queen, and curator of the Jardin du Roi, was the sole patron of
botanical studies. Fagon knew how to appreciate both knowledge and
merit; his character, as well as his rank, placed him above jealousy ;
and Tournefort found in him a disinterested protector. In 1683 he
was appointed assistant professor with Fagon at the Jardin du Roi,
whose numerous other occupations allowed him but little time for
teaching. The way in which Tournefort fulfilled this office soon
made him known, and attracted from all parts a crowd of students to
his lectures and herborising excursions. In 1688 he was commissioned
to travel through Spain and Portugal, and shortly after through
Holland and England, in order to enrich the Jardin du Roi with the
plants of these countries. These travels made him acquainted with
the most distinguished scientific men of the countries he visited, and
gained him their friendship and esteem. Being made, in 1692, a
member of the Acaddmie des Sciences, he proved by his ' Elemens de
Botanique,' which was published shortly afterwards, how well he
deserved that honour. The title of Doctor of Medicine was conferred
upon him by the Faculty of Paris iu 1698. He again left France in
1700, being sent by the king to the East to collect plants and make
observations of all kinds. In company with the German botanist
Gundelsheimer, and the celebrated artist Aubriet, he spent two years in
travelling through the islands of Greece, the borders of the Black Sea,
Georgia and the environs of Mount Caucasus, Asia Minor, and Arme-
nia. He was preparing to go to Egypt, when, hearing that the plague
was ravaging tbat country, and that his patron Fagon was dangerously
ill, he hastened back to his own country, to which he was called both
by gratitude and friendship. Having resumed his duties at the
Jardin du Roi, and being also appointed professor to the Faculty, he
spent the little spare time he had in arranging his numerous collections
and in drawing up different works, especially the account of his
travels in the Levant. The fatigues of work and his travels had much
weakened his originally robust constitution, and a violent blow which
he received on the breast from the axletree of a carriage tended still
more to impair it ; so that after lingering some mouths, ho ended his
laborious life the 28th day of November 1708. By his will he left
to the king the valuable zoological museum which he had formed, and
his library to the Abbd Bignon.
A judicious and lively mind, and a natural gaiety of disposition,
rendered Tournefort equally fitted to succeed in scientific investiga-
tions and to form the charm of his friends in society. His attach-
ment to his own country made him refuse the solicitations of Paul
Hermann, who wished to have him for his successor, and offered him,
in the name of the states of Holland, the situation of professor of
botany at Leyden, with a salary of 4000 francs (160^.)
The system of Tournefort was an advance on those of Cesalpino,
Morison, Hermann, Ray, and Rivinus, but has since been displaced by
those of Jussieu, De Candolle, and others. Authors had previously
only employed themselves in grouping plants into classes ; the much
moi-e important determination of the genera was still almost entirely
wanting. It is this subdivision of the subject which Tournefort
executed with such admirable acuteness, and which distinguishes his
labours from all that had preceded him; and it is this, joined to a
classification simple, easy, and almost always natural, which caused
his method to be afterwards adopted by the botanists of all countries.
Tournefort adopted the principle that genera should be constructed
on characters derived from both the fructification and organs of
vegetation. In seeking for order he had the good sense not t^ pretend
to an absolute regularity, which nature nowhere presents ; and felt
(which has been too often forgotten in our day, and which has intro-
duced into natural history so many useless genera, and so many
parasitical denominations) that the generic charactera must admit of
exceptions which are commanded by nature itself. Linnaous, when
again reforming the science, adopted the greater part of the genera of
Tournefort ; but having constructed his genera on characters derived
from the fructification alone, he was obliged to reject many of Toume-
fort's genera. The plates which Tournefort has given characteristic of
the genera are, even to the present day, for the most part, among the
best means of understanding them : they are well executed, and upon
a plan at that time quite new, and are a proof of his taste, as well as
of his spirit of order and obsei'vation.
Although he did not think that the consideration of the natural
relations of plants (of which the first glimpses were to be met with in
the works of Lobel and Magnol) could serve as the basis of an easy
classification, still he generally observes the most marked of these
relations, and the greater part of hia classes form one or more large
families. The separation of the woody from the herbaceous plants,
which nature frequently offers together in the same genus, and which
was admitted by the botanists of Tournefort's time, is in his system a
defect which an increased knowledge of the structure and functions of
plants has long since caused botanists entirely to abandon in their
systems of classification, however much advantage may be derived
from it for practical purposes.
Tournefort did not do for the species what he had so well accom-
plished for the genera; as he left confounded with them simple
varieties, even those which are evidently only the result of cultivation.
Neither did he think of giving them names more convenient than
those which were then in use, and which were commonly vague, and
often very long and complicated. These inconveniences Linnaeus got
rid of; and at the same time he arranged the vegetable kingdom
according to his celebrated sexual system, in which plants were placed
in classes and orders according to the number of their stamens and
pistils. But the system of Tournefort was never abandoned in France,
and the study of its principles resulted in the labours of Adanson,
Jussieu, and Do Candolle, to whom we are so greatly indebted for the
present position of systematic botany.
The ' Institutiones Rei Herbaria)' is distinguished for its clearness
and precision, and for a number of very just observations. The
historical part of this work, which is the most considerable, displays
much solid learning, which has been of great use to those who have
since his time written on the history of botanical science. The dif-
ferent travels of Tourneforb enriched botany with a great number of
species, and even of genera. He brought back from his travels in
the East, more than thirteen hundred plants, the greater part of
which were in the Herbarium of Gundelsheimer, his companion ; and
have been since examined by Willdenow, who has mentioned them in
his ' Species Plantarum.' If the history of the plants in the environs of
Paris, by Tournefort, divided into six herborisations, is of little
importance as to the number of species described (which is only four
hundred and twenty-seven), still it is a very valuable work in other
respects. By the exactness of the synonymes, and by the skill with
which the plants are referred to the nomenclature and to the i^lates of
the ancient botanists, whose errors Tournefort correct?, this work
furnishes an excellent model of criticism. There is also to be found
in it a faithful description of some rare plants, which are omitted in
his other works. Haller however rather over-estimates its value,
when he is inclined to regard it as the chief of Tournefort's writings
Cprsocipium fortd Tournefortii opus'). One may judge of Tourne-
fort's reputation, and of the value that was put upon whatever he
wrote, from the fact of his lectures on Materia Medica having been
collected by his pupils, and translated and published in English
before they appeared in French, which was not till some years after
his death. The account of Tournefort's travels was for a long time the
source of our most accurate information about the countries which he
visited. The simplicity of the style does not lessen the interest of the
narrative. To the observation of nature he joins everywhere that of
men, manners, and customs, and shows an extensive knowledge both
of history and antiquity.
Among the manuscripts left by Tournefort was a botanicfil topo-
graphy of all the places which he had visited, and a large collection of
critical and other observations, which has never been published,
though it was entrusted to Reudaulme to arrange for that purpose.
The genus of American shrubs, to which Plumier, out of honour to his
master's memory, gave the name of ' Tournefortia,' derives its chief
interest from this celebrated name.
The following is a list of Tournefort's principal works : — * Eldmens
de Botanique, ou Methode pour connattre les Plantes,' 3 vols. Svo,
with 451 plates, Paris, 1694. Some imperfections in this wprk were
pointed out by Ray, to whom Tournefort replied in a Latin work,
entitled 'De Optima Methodo Instituendd in Re Herbaria ad Sapientera
Virum G. Sherardura Epistola, in qua respondetur Dissertation! D.
Rail de variis Plantarum Methodis,' Svo, Paris, 1697. In 1700 he
published a Latin version of his 'Elements of Botany,' with many
additions, and a learned preface, containing the history of the s^cience ;
it was entitled ' Institutiones Rei Herbaria;, ed. altera, Gallica, long6
auctior,' 3 vols. 4to, with 476 plates, Paris. After his expedition to
136
TOURNEMINE, LE PfiRE.
TOURNEUR, PIERRE LE.
136
the East he published ' Corollarium Institutionum Rei Herbaria}, in
quo Planta;, 1356 . . . . ia Regiouibus Orientalibus observatse, recen-
aentur . . . . et ad sua Genera revocantur,' 4 to, with 13 plates, Pario,
1703. This was afterwards added to Aut. de Jussieu's edition of the
'Elements,' in 1719, 3 vols. 8vo, Lyons. 'Histoire des Plan tes qui
naissent aux Environs de Paris, avec leurs Usages dans la Mddecine,'
12 mo, Paris, 1693. An improved edition of it was given by Bernard
de Jussieu, in 2 vols. 12mo, 1725; and an English translation was
published by Martyn, 2 vols. 8vo, London, in 1732. ' Relation d'un
Voyage du Ldvant, fait par Ordre du Roi, contenant I'Histoire Ancienne
et Moderno de plusieurs lies de I'Arcliipel, les Plans des Villes et des
Lieux les plus considdrables, et enrichie do Descriptions et de Figui'es
de Plantes, d'Animaux, et d'Observations singulidres touchant I'His-
toire Naturelle.' The first volume of this work was printed at the
Louvre before his death ; the second was completed from his manu-
scripts; and both were published in 1717, in 2 vols. 4to. There have
been several French editions, and it has been translated into English,
3 vols. 8vo, London, 1741. ' Traitd de la Mati6re M(\$dicale, ou I'Histoire
et rUsage des Mddicamens et leur Analyse Chimique, Ouvrage post-
hume de M. Tournefort, mis au jour par M. Besnier,' 2 vols. 12mo,
Paris, 1717. This work, which was not published in French until
after the death of the author, had been already translated and pub-
lished in Eng;lish, 8vo, London, 1708 and 1716.
TOURNEMINE, LE PE'RE RENE' JOSEPH, Jesuit, occupies a
subordinate but useful and honourable position in the literary history
of France. He belonged to an ancient family in Bi'etagne, and was
born at Rennea on the 26th of April 1661. In 1C80, he entered the
Society of the Jesuits. His superiors thought that his peculiar talents
qualified him for a teacher, and his subsequent career showed the
correctness of their opinion. For about twenty years he taught in
different colleges of the Order, with eminent success, humanity,
rhetoric, philosophy, and theology ; and while thus instructing others
he was accumulating information in the belles-lettres, — physical,
moral, and metaphysical science — theology, history, geography, and
numismatics — that was to fit him for the employment of neax'ly
twenty years of his matured intellect.
In 1701 Tournemine was called to Paris to take the management of
the ' Journal de Trevoux,' a periodical publication, which, although at
times disfigured by the narrow views and unamiable temper of secta-
rianism, has I'endered services to literature that entitle it to a better
reputation than the equivocal one in which it is held by the mass of
readers who know it ouly from the sarcasms of Voltaire. Tourne-
mine was the principal editor of this work for nineteen years, from
1701 to 1720. He contributed to the journal during this time a
number of curious dissertations and analyses which procured for it a
high reputation throughout Europe. Superior to the partisan spirit of
many of his brethren, he was sufficiently impartial to combat the
systems of Hardouin and Panel ; and free from bigotry, although sin-
cerely religious, he praised highly the ' Merope ' of Voltaire, and even
when engaged in controversy with its great author always treated him
with respect.
In 1720 he was freed from the laborious task of editorship, but still
continued to contribute largely to the pages of the ' Journal de Tre-
voux.' Indeed the variety of studies to which, as teacher, and editor
of a critical journal, he had found it necessary to turn his .attention,
appears to have produced in him desultory habits of thought, and
prevented the concentration of his powers tipon any one topic, so as
to enable him to exhaust it. The Order, regretting that his time aud
talents should be thus wasted, appointed him librarian to the residence
of professed Jesuits (maison de professe) at Paris, and after the death
of Bonami (1725) employed him to continue the literary history of
the society from the period to which it had been brought down by
Southwell. Tournemine entered with enthusiasm upon his new task.
He called upon all the provinces to supply him with memoirs, and
instituted researches in the archives of the society at Rome. The
habits of thought however which he had contracted led him to under-
fake the work on a scale beyond what it was possible to accomplish,
and unfitted him at the s-ame time for persevering routine labour.
The over-minute investigation of details, and the episodical inquiries
into which he was continually seduced, diverted him from the com-
pletion of the work he had undertaken, and he failed to perform his
engagements.
Tournemine died at Paris on the 16th of May 1739, in the seventy-
ninth year of his age, regretted by all who knew him. He has left no
work worthy of his talents and opportunities, yet he has not been
without influence upon literature. As a teacher and journalist, and in
the conversation of private society, he prompted aud encouraged many
young writers. His knowledge was at the service of every one who
asked it, and the information which he did not himself elaborate into
any enduring work was yet of material service to others. Ho
belonged to a class of minds which, although they leave little or no
permanent trace of their individuality, are indispensable to the
creation of a national literature — those who go to form a literary
public, animating and instructing writers by its sympathy and subor-
dinate co-operation.
A list of Tournemino's writings is given in the 42nd volume of the
' Mcmoires de Niceron,' and in the Dictionary of Chaufpid. They
consist chiefly of his contributions to the * Journal de Trevoux.' He
contributed the chronological tables to the edition of the Bible pub-
lished by Duhamel in 1706. He published in 1719 an edition of
Menochius's ' Scriptural Commentaries,' to which he appended a
system of chronology and twelve dissertations on different points of
the chronology of the Bible. In 1726 he published an edition of
Prideaux's ' History of the Jews,' and added to it a dissertation on
the books of Scripture not recognised as canonical by Protestant?, aud
some remarks upon the ruins of Nineveh and the destruction of the
Assyrian empire. Tournemine's ' Reflexions sur rAth(5i8me ' were
printed as an introduction to two editions of FiSndlon'a • Traitd sur
i'Existence de Dieu;' and in reply to Voltaire, who had invited him
to clear up his doubts, he published in the 'Journal de Trevoux'
(October 1735) a letter on the immateriality of the soul, which does
not appear to have convinced the philosopher. Sketches of the life of
Tournemine are contained in the 'Journal de Trevoux' for September
1739, and in Belingan's ' Observations sur les Ecrivains Modernes,'
vol. xviii. There is also a well-executed memoir of him by M. Weiss
in the ' Biographic Universelle.'
TOURNEUR, PIERRE LE, was bom at Valognes in 1736, He
studied in the college Des Grassins at Coutances, where he distin-
guished himself, and appears to have repaired to Paris about the year
1767 or 1768, with a view to earn his subsistence by literary labour.
His history from that time till his death, in 1788, ia little more than
an account of his publications and the reception they met with.
He published in 1768 a thin octavo containing a few prize essays
in the years 1766 and 1767; and an 'Eloge de Charles V., Roi
de France,' which had been unsuccessful in the competition of the
French Academy in the latter year. This seems to have been his
only attempt at original publication, with the exception of a number
of prefaces and some verses in two little volumes, entitled ' Jardina
Anglais, ou Varidtes tant originales que traduites,' which appeared in
1788. His original composition betrays an entirely common-place
mind.
In 1769 Le Tourneur published a collection of tales translated from
the English, of no importance in itself, and which attracted little or
no attention. Towards the close of the same year, or in the beginning
of 1770, he brought out a translation of ' Young's Night Thoughts '
and miscellaneous poems, which was more successful. He has taken
great liberties with the ' Night Thoughts,' omitting several passages,
and altering the whole arrangement of the poem, with a view to
render it less startling to French taste. Grimm sneei-ed at the work,
but Diderot and Laharpe declared themselves warmly in its favour.
The success of the translation of the ' Night Thoughts ' appears to
Lave decided Le Tourneur to confine himself in future to that kind of
employment. His first undertaking was a complete translation of
the dramatic works of Shakspere. In this enterprise he was associated
at first with the Comte de Catuelan and Fontaine Malherbe, both of
whose names are subscribed along with his in the dedication to the
king, prefixed to the first volume. But his associates deserted him
after the publication of the second volume, and the remaining
eighteen were the unaided work of Le Tourneur. The first volume
appeared in 1776 ; the last in 1782. It is difficult for an Englishman
to do justice to the merits of a translation of Shakspere into any
foreign language. Ho feels the unavoidable defects too strongly.
Thus much however may be said of Le Tourneur's, that it honestly
aims at giving Shakspere as he is. The translator has evidently bene-
fited by his knowledge of the German translation by Eschenburg
(Ziirich, 1775-87), and has prefixed the remarks of that critic to
several of the plays. The version is in prose, and by a prosaical
mind, yet enough of Shakspere remains to impress minds which know
him through no other medium with some sense of his greatness. It
is still the best French translation of Shakspere, and as such was
the prefatory discourse excited the anger of Voltaire, who thought he
saw in it an attempt to decry the merits of the great French drama-
tists. The controversy to which Voltaire's denunciations gave rise
was of advantage to the work by creating a public interest in it. Le
Tourneur seems to have taken no part in the discussion : in an adver-
tisement prefixed to the ninth volume, he quietly observes, "This
work has triumphed over the absurd hostility declared against it at ita
first appearance, and the extraordinary wrath of a great poet the
most ardent panegyrist of Shakspere so long as he was unknown, his
unaccountable enemy since he has been translated." Of the original
subscribers to the quarto edition a large proportion were English : the
sale however increased as the work advanced ; a quarto and an octavo
edition were published simultaneously ; and Le Tourneur, who seems
to have become publisher as well as author, adventured on the specu-
lation of publishing in numbers, by subscription, pictorial illustrations
of Shakspere.
The translation of Shakspere was far from being the only employ-
ment of its author during the time he was engaged upon it. In 1770
he published a translation of Hervey's ' Meditations among the
Tombs ; ' in 1771 a translation of Johnson's * Life of Savage,' together
with au abridgment of the same author's 'Life of Thonison ; ' in 1777
he published a translation of Macpherson's 'Ossian;' in the same
year a translation of Soame Jenyns's ' View of the Evidences of
Christianity;' in 1784-87, a translation of 'Clarissa Harlowe;'in
137
TOURRETTE, MARC-ANTOINE.
TOUSSAINT LOUVERTURE.
133
1788, a tranfelation of ' Interesting Memoirs of a Lady; ' and his trans-
lation of Pennant's ' Description of the Arctic Regions ' appeared the
year after his death. He also revised the translation of the ' Universal
History ' begun by Psalmanazar, which some young authors had under-
taken at his suggestion.
These are his most important publications. They deserve a place
in the history of letters, inasmuch as they contributed to nourish that
taste for English literature which was then growing in France, and
which has contributed so much to modify not only the taste, but the
character of the nation. Diderot, the first to recognise the merits of
Le Tourneur as a translator, was the first eminent author of France
who really felt the merits of English imaginative writing ; his sanction
encouraged others to feel, or affect to feel, its beauties. Le Tourneur
had the principal share in enabling merely French readers to judge in
some measure for themselves. The literary taste of France has not
become assimilated to England since the time of Diderot and Le
Tourneur, but it has been since their publications entirely revolu-
tionised. Gothe, in his ' Dichtung und Wahrheit,' and in his
' llameau's Neffe,' has explained the influence which Diderot exercised
over the modern literature of Germany, both by his own writings and
by directing attention to English authors. It was in part through
the medium of French literature that the English literature was
made to exercise so strong an influence over that of Germany, The
part which Le Tourneur played in this intellectual revolution was an
humble but still an important one.
It has been intimated above that Le Tourneur in translating Shak-
spere was indebted to Eschenburg, and this of itself would imply that
he was acquainted with the German as well as with the English lan-
guage. He published some translations from the German: in 1787
one of Sparmann's 'Journey to the Cape of Good Hope;' in 1788,
one of the 'Memoirs of Baron Trenck.' In 1785 he translated and
published a selection from the elegies of Ai'iosto.
The persevering industry displayed in this brief recapitulation of
what was accomplished by Le Tourneur in the space of eighteen
years, would lead to the inference that he must have secured an
independence by his labour^j. In addition to this source of income,
he held for a number of years the appointment of private secretary
to Monsieur, afterwards Louis XVIII, ; and for a short time before
his death that of censeur-royal. An anc«iymous biography is prefixed
to his ' Jardins Anglais ; ' and M, Weiss has contributed a correct
outline of its leading incidents to the ' Biographie Universelle.' Le
Tourneur had not the slightest pretension to the character of a man
of genius, but he was a respectable and useful labourer in the field
TOURRETTE, MARC-ANTOINE -LOUIS CLARET DE LA,
naturalist, was born in August 1729, at Lyon, where his father was
commandant of the city, Pr^vot des Marchands, and President h, la
Cour des Monnaies. He commenced his elementary studies at a
college of Jesuits in Lyon, and vias afterwards sent to the College de
Harcourt at Paris. He was early admitted a member of the Academy
of Sciences at Lyon, and during the last twenty-five years of his life
acted as secretary to that body. On returning to his native city he
was appointed a Conseiller h, la Cour des Monnaies, but he pursued
the study of the belles-lettres with great assiduity. Dissatisfied how-
ever with the tendency of these studies, he engaged in that of natural
history. He commenced with zoology and mineralogy, and soon
formed a large collection of insects and minerals. The establishment
of a school of veterinary medicine, by Bourgelat, at Lyon, directed his
attention to botany. In conjunction with the Abbd Rozier, he was
appointed to superintend the formation of a botanical garden, and
the giving instruction to the pupils in botany. The result of these
exertions was the publication, in 1766, of an elementary work on
botany, entitled 'Demonstrations dldmentaires de Botanique,' 8vo.
This work, at first in two volumes, contained a general introduction
to a knowledge of the structure of plants and their arrangement,
with descriptions of the most useful and curious. In the first edition
fhe introductory matter was entirely drawn up by Tourrette, the
description of the plants by Rozier. In a second edition nearly the
whole was rewritten by Tourette. This work has since gone through
other editions. The fourth consists of four volumes of letter-press in I
8vo, and two volumes of engravings in 4to, containing notices of the
lives of both Tourrette and Rozier.
In 1770 Tourrette published a voyage to Mount Pilat, giving a geo-
graphical account of the district, and a list of the plants which he
discovered there. In 1795 he published the 'Chloris Lugdunensis'
(8vo), in which he described the plants of the neighbourhood of Lyon,
and paid especial attention to those belonging to the class Crypto-
gamia. He published numerous papers on various departments of
natural history, in the Transactions of Societies and Journals, Those
most worthy of mention were on the origin of Belemnites, on vegetable
monstrosities, and on the Helminthocorton, or Corsican moss. He made
numerous excursions for the purpose of collecting plants in various
parts of France and Italy. In some of these herborisings he was accom-
panied by Jean Jacques Rousseau, with whom he was intimate ; and
in the published correspondence of that philosopher are several letters
written to Tourrette. He took great pains in introducing foreign
trees and shrubs, which he cultivated in his father's park near Lyon,
and at his own residence in the city he had a garden containing 3000
species of plants. Ho was a correspondent of most of the great
botanists of his day, as Linnoius, Adanson, Jussieu, and others.
During the siege of Lyon he was exposed to fatigue, anxiety, and
hardship, which brought on an attack of inflammation of the lungs
that terminated his existence in 1793. Tourrette, like most of the
botanists who adopted the system of Linnajus, mistook its object, and
made it assume a position and importance of which it was utterly
unworthy. The consequence was that in his ' D(^mon8tration8 ' and
other works he sought more anxiously to add to our knowledge of
existing species than to elucidate the structure and functiona of the
vegetable kingdom.
{Notice sur la Vie de M. Tourrette, in the fourth edition of the
Demonstrations Mementaires de Botanique.)
* TOUSSAINT, ANNA LUIZE QEERTRUIDE, the maiden name
of the most popular living authoress of Holland, and that by which
she is still most generally known, though she has since 1851 been
married to Mr. Bosboom, a painter of some reputation at the Hague,
since which she writes her name A. L. G. Bosboom Toussaint. She
was born on the 16th of September 1812, at the town of Alkmaar, in
North Holland, the daughter of an apothecary, who was descended, as
his name suggests, from a family of French refugees. Always of a
weakly constitution, she was nevertheless strongly attached to study,
and though her compositions, exclusive of magazine articles, consist
entirely of novels and romances, she is said to have expended on the
details of one of them no less than two years' research, an amount
of investigation which would have qualified her for writing a
history. She has always shown a strong predilection for English
subjects. Her first romance in 1838 was 'De Graaf van Devonshire,'
or ' the Earl of DevouBhire,' founded on the adventures of that Courte-
nay who was supposed to have engaged the affections of the two sister-
queens, Mary and Elizabeth. ' Engelschen te Rome,' or ' The English
at Rome,' succeeded, in looking at which the English reader can hardly
forbear a smile to find that the authoress's Scotch bighlander swears
by St. Patrick, sings ballads beginning with ' From mighty Odin's
airy hall,' and bears the singular name of Hugh Mac-o-Daunt. A
series of three romances from the time of Dudley earl of Leicester's
inglorious career in the Netherlands, runs up to ten volumes in all,
and at the conclusion of the last of them, 'Gideon Florensz,' the
authoress in 1855 announced her intention of laying down the pen.
Though all these works are very popular in the Netherlands, no
translation or account of any of them has as yet appeared in English.
The only notice of Madame Bosboom Toussaint that we are aware of
is an article in the 40th volume of the 'Westminster Review,' on a
tale entitled ' Lauernesse House,' in which the controversies of the
Roman Catholic faith and the Protestant are embodied in the hero
and- heroine. The historical romances of this popular authoress appear
to be those of her works which are held in most esteem, but her novel
of ' Don Abbondio 11,' a delineation of modern Dutch manners, in
which one of the characters is nick-named ' Abbondio,' from the well-
known curate of that name in Manzoni's ' Betrothed,' is written in a
lively vein and would probably be more likely to secure in a trans-
lated shape, the interest of the English reader.
TOUSSAINT LOUVERTURE, one of the most extraordinary men
known to have been born of the negro race, was born at Breda, a
property which then belonged to the Count de Noi5, near Cape Town
in St. Domingo, in 1743. His father and mother were both African
slaves. During the prosperity of Toussaint, a genealogy was compiled,
it is insinuated with his privity, which made his father the younger son
of an African king. This may be true or not; it is of little consequence.
The first employment of Toussaint-Breda (so called from the place
of his birth) was to take care of the cattle on the estate. He received
the elements of education from a negro of the name of Pierre-Baptiste.
As soon as he could read and write his name, he was promoted by M.
Bayon de Libertat, manager of the estate, to be his coachman. He
gained the confidence of his master, and was appointed to exercise a
kind of superintendence over the other negroes. In this position the
Revolution found him. He took no part in the first insurrections, and
is said to have expressed himself violently against the perpeti'ators of
the massacres of 1791.
The negroes not unnaturally made attachment to the royal cause
the pretext for rising in arms against masters who, with equality and
the rights of men in their mouths, still sought to keep them slaves.
Toussaint, from 1791 and till the appearance of the proclamation of
the 4th of February 1794, which declared all slaves free, was alike
conspicuous for his zeal in the cause of the Roman Catholic religion
and of royalty. He held at first the title of ' Mddecin des Armdes du
Roi,' in the bands of Jean Frangais, but soon exchanged it for a military
appointment. Though placed under arrest by the chief just named,
and delivered by the other negro leader, Biassou, the ferocity of the
latter determined Toussaint to ally himself most closely with Jean
Frangais. He became his aide-de-camp. At this time Toussaint was
high in the confidence of the Spanish president, Don Joachim Garcia,
and apparently entirely guided by his confessor, the curd of Laxabon.
When the negroes rejected the first overtures of the French commis-
sioners, Toussaint assigned as his reason, that they had always been
governed by a king ; could only be governed by a king ; and having
lost the king of France, had betaken themselves to the protection of
the king of Spain.
180
TOUSSAINT LOUVERTURE.
TOWEns, JOSEPH, LL.D.
HO
The proclamation of the 4th of February 1794, emancipating the
slaves, worked a cliauge in his sentiments. Ho opened a communiua-
tion with General Laveaux ; and receiving the assurance that ho would
be recognised as a general of brigade, occupied the Spanish posts in
his neighbourhood, and repaired to the camp of the French general.
His defection was followed by the surrender of Marmalade and other
strong places, and throw confusion into the Spanish ranks. An
exclamation of Laveaux on learning the consequences of Toussaint's
joining his standard ("Comment, maia cet homme fait 'ouvcrture'
partout") is said to have been the origin of the name Toussaint sub-
sequently adopted. Laveaux, left by the departure of the commis-
sioners governor of the colony, treated him at first with coldness and
distrust ; and Toussaint, now past his fiftieth yeai-, reduced to inaction
and jealously watched, had reached to all appearance the close of his
political career.
In 1795, in consequence of a conspiracy of three of the Mulatto
generals, Laveaux was arrested at Cape Town. Toussaint Louverture
assembled his negroes ; soon found himself, by the support of the
partisans of France, at the head of ten thousand men ; marched upon
the capital, and released the governor. Lateaux in the enthusiasm of
his gratitude, proclaimed his deliverer the protector of tlie whites and
the avenger of the constituted authorities. " He is," runs the governor's
proclamation, "tho black Spartacus, who, Raynal predicted, would
arise to avenge his race." Toussaint Louverture was created a
general of division, and became in fact the supreme arbiter of the
fortunes of the colony. When the peace between France and Spain
was concluded, Jean Fran§ai8 repaired to Madrid, leaving Toussaint
the only powerful negro leader in St. Domingo. He reduced the
whole of the northern part of the island to the dominion of Franco,
with the exception of the Mole of St. Nicholas, of which the PJuglish
retained possession. He was the first who succeeded in establishing
discipline among the armed negroes.
Tho arrival of the commissioners sent by the Directory to pro-
claim the constitution of the year 3, confirmed the credit of Toussaint.
In April 1796, Sonthonax appointed him commander-in-chief of the
armies of St. Domingo. In the month of August Toussaint proceeded
to the Cape at the head of a large body of cavalry on a visit to Sontho-
nax. The day alter his arrival he propose(l, at a meeting of the civil
and military chiefs, that the commissioners should be sent back to
France. Kaymond, a Mulatto, was the only commissoner allowed to
remain. The civil admiuistration of the colony was confided to Ray-
mond in the first instance, but lie soon resigned the charge into the
hands of Toussaint. Fully aware of the boldness of the step he had
taken, Toussaint hastened to remove any suspicions that might arise
in the minds of the Directory. He sent two of his children to receive
their education at Paris ; and along with them Vincent, a chef de bri-
satisfaction. The Directors prafes3od to bo perfectly satisfied, and
appointed a new commission, at the head of which was placed General
Hddouville.
Hddouville, on his anival at St. Domingo showed his suspicions of the
negro general by landing within the Spanish territory. Toussaint was
at this time engaged in negoclations with General Maitland for tho
surrender of tlie strong places held by the English. It was generally
known that Hddouville's staff spoke openly in the most hostile and
insulting terms of Toussaint ; nevertheless he visited the commissioner
with scarcely any attendants, and professed the utmost devotion to
the French government. Hddouville asserted his right as agent of the
republic to reserve the power of ratifying or refusing to ratify any
, convention between Toussaint and the British commanders. The
negro chief nevertheless i-eceived the capitulation of Port-au-Prince,
St Marc, Jerdmie, and the Mole of St. Nicholas without consulting
Hddouville. On the day when the British troops marched out, a public
exchange of civilities took place between Toussaint Louverture and
General Maitland. All this increased the distrust of the commissioner,
who showed it by seeking to thwart the St. Domingo chief in every-
thing. Toussaint Louverture persuaded his countrymen to resume
their agricultural occupations. Hddouville soon after issued a procla-
mation denouncing the dmigrds and professing to regulate the political
relations of whites and negroes. Toussaint immedintely issued another
proclamation declaring that there were no dmigrds among the natives
of tho island ; and that the negroes were de facto free, but that it was
desirable they should continue during five years to labour for their
old masters, receiving one-fourth of the produce. His partisans were
in the mean time industriously spreading the opinion that Hddouville
was an enemy to the negroes and to the tranquillity of the colony.
An insurrection broke out at the Cape, which was suppressed by
Toussaint ; but the commissioner with all his adherents, to the num-
ber of twelve or fifteen hundred men, took refugo on board three
French frigates which wore lying off the islaud, and sailed for France.
Their departure was the signal for the breaking out of the animosity
between the mulattoes and the negroes into acts of open violence.
Bigaud, the mulatto chief, sanctioned the massacres committed by his
partisans; Toussaint did all in his power to repress the ferocity of his.
One strong place was taken from the umlattoos by the negroes after
another, until Iligaud was shut up in Cayes, tho only hold that
remained to him. This was towards the close of 1799, aud Bonaparte
had already assumed tho reins of government in France. One of the
first steps of the new ruler was to send a deputation to Toussuint,
composed of his personal friends Raymond and Vincent, and General
Michel. They brought tho intelligence that Toussaint was confirmed
in his authority ; and Rigaud, seeing himself abandoned even by his
own partisans, embarked with a few of his retainers to seek an asylum
in France.
Toussaint Louverture was now at the summit of hb prosperity. He
assumed much state ; affected to cast a shade of mystery round the
circumstances of his earlier career; and took pride in proclaiming himself
the negro deliverer foretold by Rajrnal, He preserved great simplicity
in his own person, but surrounded himself with a brilliant staff. In
January 1801, ho conquered the Spanish part of St. Domingo, He
presented to a central meeting of his partisans] a scheme of a colonial
constitution, by which he was appointed governor for life, authorised
to name his successor, and to nominate to all offices under govern-
ment. He exercised this authority to the full extent. He quelled an
insurrection of the negroes, and did not hesitate to punish with death
his own nephew, who was at the head of it. Under his strict but just
sway the agriculture and commerce of St. Domingo flourished.
Bonaparte in the meantime preserved an ominous silence towards
all Toussaint's overtures of friendship. The mind of the latter, dis-
quieted by the coldness of the First Consul, was not tranquillised by
the proclamation issued immediately after the peace with England,
declaring that slavery was to continue in Martinique and Cayenne, and
St. Domingo to be restored to order. Toussaint met it by a counter-
proclamation, issued on tho 18th of December 1801, in which he pro-
fessed obedience to the republic, but at the same time appealed to the
soldiers in language which left no doubt as to his resolution to repel
force by force. Bonaparte despatched a sqrmdron of fifty-four sail,
under tlie command of General Le Clerc, his brother-in-law, to reduce
St, Domingo.
The first view of this force discouraged Toussaint himself. He soon
rallied, but his followers were intimidated and divided. The flattery
of the First Consul, and the solicitations of his own childi'en, were
bi'ought to bear on the negro chief in v.ain. He retired to the Morue of
Chaos, and entombed his treasures where the enemy might seek for
them in vain. On February 17th, 1802, he was proclaimed an outlaw.
The negroes who remained in arms were defeated in all parts of the
island ; Toussaint continued nevertheless to defend himself, making a
desert around him to obstruct the progress of the enemy. At last the
defection of Christophe and Dessalines obliged him to listen to terms.
The sentence of outlawry pronounced against him was reversed. He
was received with military honoura on paying a visit to Le Clerc, and
General Brunei took his advice on the imposition of taxes, and the
selection of cantonments.
Brunet invited Toussaint to a conference mid-way between Sancey
and Gonaives, on the lOfch of June; and when the generals retired to hold
a consultation, the negro guard was disarmed, and their chief arrested
and sent on board the Crdole, which immediately set sail for Cape
Town, where he was transferred to the Heres, a vessel of the line.
After a voyage of twenty-five days he was landed at Brest, and without
delay sent to Paris. He was for a short time lodged in the Temple,
but soon after conveyed to the castle of Joux, near Besan5on, where
he was subjected to a close and sevei-e confinement. His faithful
attendant Mars Plaisir was removed from him. After ten months of
rigorous imprisonment, he died on the 27th of April 1803.
Toussaint, like all eminent and successful politicians, wa^ marked
by a strong inclination and power to conceal his sentiments and inten-
tions. There was a good deal of imagination or romance in his com-
position. He had strong devotional feelings and a nice sense of domestic
morality. His reserved and energetic nature commanded the respect of
the negroes, enabled him to restrain them from excesses and keep
them to steady labour, aud he thus restored confidence to the whites.
He loved splendour in his attendants, but was plain in his personal
habits. St. Domingo was peaceable and prosperous imder his govern-
ment. These facts are proved by the concurring testimony of friends
aud enemies ; and they entitle him to be classed among great men.
More it would be imprudent to say positively, considering how con-
flicting are the witnesses respecting him, and how biassed by passion
their evidence. Of the injustice and selfish meanness of Bonaparte's
conduct towards him there can be scarcely two opinions.
After the death of Toussaint Louverture, his family were confined at
Brienne-en-Agen, where one of his sous died. The survivors were set
at liberty after the restoration of tho Bourbons. The widow died in
1816, in the arms of her sons Placide and Isaac. M. du Broias has
published a sketch of the life of Toussaint Louverture.
TOWERS, JOSEPH, LL.D., was born in Southwark, on tho 13th
of March 1737. His education was much neglected, but being fond of
reading, he picked up a good deal of knowledge in a miscellaneous
way. He was apprenticed to a printer at Sherborne in Dorsetshire,
and returned to London in 1764, where at firat he got his living as a
journeyman printer, and afterwards set up a bookseller's shop in Fore
Street. During this time he was also actively engaged in writing for
the press, and, in addition to other publications, wrote the first seven
volumes of ' British Biography,' of which the first was published in
1766. As his business did not answer,— a thing not surprising, con-
sidering his literary engagements, — ho relinquished it in 1774, and
became the minister of a Dissenting chapel at High gate. His theolo-
Itl
TOWNLEY, EEV. JAMES.
TOWNSHEND, VISCOUNT.
142
gical opinions were Aiian, though he was closely connected with the
Unitarian body. In 1778 he was chosen forenoon preacher at a chapel
prietors of the ' Biographia Britannica ' to write several lives for the
new edition of the work edited by Dr. Kippis, of which however only
five volumes appeared (1777-83, down to the letter F). Towers
received the degree of LL.D. from the University of Edinburgh in
1779. 'He died on the 20th of May 1799, in his sixty-third year. His
pamphlets and smaller works were collected and published in 1796, in
3 vols. 8vo. They are of a miscellaneous nature, but most of them
on political subjects. (Lindsay's Funeral Sermon.)
TOWNLEY, REV. JAMES, the second son of a merchant, was
born in London in 1715. He was educated at Merchant Tailors'
School, elected thence to St. John's College, Oxford, and took orders.
After having held two lectureships in London, he was appointed,
through the interest of his wife's family, to the living of St. Bennet,
Gracechurch Street. Afterwards he was grammar-master in Christ's
Hospital, and in 1759 was appointed head master of Merchant Tailors'
School and held that office till his death in 1778, which happened soon
after he had been presented to a living in Wales. He is said to have
been admired as a preacher : and some single sermons of his are in
print. But he is chiefly known on account of his intimacy with
Hogarth and Garrick. To the former he and Morell gave material
assistance in the composition of his 'Analysis of Beauty;' and he
got the credit of having much assisted the latter in his dramatic works.
The popular farce of ' High Life Below Stairs,' first played in 1759,
was at length owned by him. He was also the author of two other
farces, which were unsuccessful ; but one of them, ' False Concord,'
contains both characters and dialogue which were borrowed in Garrick
and Colman's comedy of ' The Clandestine Marriage.' The closeness
of Townley's connection with Garrick is further evidenced by the
fact that he received from Garrick, and held for some years, the living
of Hendon.
TOWNSHEND, _ CHARLES, VISCOUNT TOWNSHEND, an
eminent statesman in the reigns of George 1. and George II., was the
second viscount of that name, and was born in the year 1676. The
family of the Townshends was a very ancient family in Norfolk, and
had been settled at Rainham from the middle of the 16th century.
been one of the leading members of the Presbyterian party previous
to the Restoration, and having zealously co-operated to bring about
that event, was rewarded by Charles II. with the title of Baron
Townshend in 1661, and was, in 1682, raised to the rank of viscount.
He died in 1686, when his son was only ten years old. On the latter's
taking his seat in tlie House of Lords, when he became of age in
1697, he first acted with the Tories, but very soon attached himself to
the Whigs, and especially to Lord Somers. When William III., just
before his death, in the beginning of 1702, was endeavouring to form
tical consequence to be named for. the Lord Privy Seal. (Coxe's
♦Memoirs of Sir Robert Walpole,' vol. i. p. 113, 8vo ed.). During the
reign of Anne, Lord Townshend was appointed, in 1705, one of the
commissioners to treat for the union with Scotland; in 1707, captain
of the yeomen of the queen's guard ; in 1709, joint plenipotentiary
with the Duke of Marlborough in the negociation for peace at Gertruy-
denberg, and in the same year ambai=Eador extraordinary to the States-
General of the United Provinces. In this last capacity he concluded
the treaty known by the name of the Barrier treaty, which secured the
assistance of the States-General for carrying out the Hanoverian suc-
cession, and engaged the endeavours of England to procure in a treaty
of peace the Spanish Low Countries as a barrier for the States- General
against France. On the dismissal of the Whig and the formation of
the Oxford ministry in 1710, Lord Townshend lost bis appointment of
captain of the yeomen of the queen's guard.
In the session of 1712 the Commons fell violently on the Barrier
treaty, and voted that "the Lord Viscount Townshend, and all who
negociated and signed, and all who advised the ratifying of the said
treaty, are enemies to the queen and kingdom." This vote was
followed up by the Representation to the queen, in which the treaty
was discussed very severely and at length. The Representation may
be read in the 'Parliamentary History,' vol. vi. p. 1095 ; or in Swift's
' History of the Four last Years of the Queen,' (' Works,' Scott's edition,
vol. v. p. 269.)
With the accession of George I., in 1714, there came a complete
change of foreign policy ; and the persecuted negociator of the Barrier
treaty was now,selected to be chief minister of the new king. Lord
Townshend had been one of the Lords Justices named by George I.,
in pursuance of the Act passed in 1706 for securing the succession ;
and while George was yet at the Hague, on his way to England, he
appointed Lord Townshend secretary of state, with the power to
name his colleague. On the recommendation of Horace (afterwards
Lord) Walpole, his brother-in-law, Lord Townshend named as his
colleague General (afterwards Earl) Stanhope. [Stanhope, James,
Earl.] Lord Townshend had been recommended to George by
Bothmar, his agent in England, and with Bothmar's recommendation
the praises of all the principal statesmen at the Hague had concurred.
Lord Townshend had now been twice married. His first wife was
Elizabeth, the second daughter of Thomas, Lord Pelham, and half-
sister of the subsequent Duke of Newcastle. After her death ho
married, in 1713, Dorothy, sister to Sir Robert Walpole.
The administration formed under Lord Townshend was entirely
Whig. Charles II. on the Restoration, and William and Anne, on
their respective accessions to the throne, had pursued the plan of
combining the leading members of opposite parties in the ministry :
but during Anne's reign party warfare assumed a more determined
character, and her last ministry, that of Lord Oxford, had consisted
exclusively of Tories. This monopolising precedent was now turned
to the advantage of the Whigs. Lord Townshend was prime minister,
though l)is name had not yet come to be estabhshed ; and Walpole,
who in a short time approached him in influence in the ministry, held
at firet only the subordinate post of paymaster of the forces, but after
the death of Lord Halifax, in the next year, became chancellor of the
exchequer and first lord of the treasury. [Walpole, Sir Robert.]
The principal acts of Lord Townshend's ministry were the impeach-
ments of the principal members of that which had preceded, and the
Septennial Bill. The latter measure is a standing reproach against
its Whig authors ; and though the objection, so often urged, to the
power of parliament to prolong the existence of the then sitting
House of Commons is on the face of it absurd, the reproach is in
other respects deserved. Archdeacon Coxe states that Lord Towns-
hend and Walpole were opposed to the impeachment of Lord Oxford
for high treason, and strongly recommended the more judicious course
of charging him with high crimes and misdemeanours. (' Memoirs of
Sir Robert Walpole,' vol. i. p. 126.)
The Scotch rebellion took place at the latter end of 1715. When
the participation of Sir William Wyndham in the preparatory intrigues
was discovered, his relationship to the Duke of Somerset, an influential
Whig nobleman, and a member of the cabinet, caused a difficulty
about arresting him, which the firmness of Townshend surmounted.
The scene in the council on this occasion is minutely described by
Archdeacon Coxe. (Id., p. 128.) "As the king retired into his closet
he took hold of Lord Townshend's hand, and said, ' You have done
me a great service to-day.' "
In the summer of 1716 George visited Hanover, and was accom-
panied by Stanhope : Lord Townshend remained in England. He had
sti'ongly opposed the king's wish of revisiting his native dominions ;
and even after the repeal of the restraining clause in the Act of Settle-
ment, had reiterated his objections to the king's departure from
England. While the king was in Hanover various causes combined to
estrange him from the minister in whom hitherto his confidence had
been unbounded, and the ultimate result was Lord Townshend's
dismissal from office. The causes of this event have been considered
at some length by Archdeacon Coxe, in his ' Memoirs of Sir Robert
Walpole;' and by Lord Mahon, in his ' History of England from the
Peace of Utrecht to the Peace of Aix-la-Chapelle ' (vol. i., ch. 7, 8).
Lord Mahon has made it his object to vindicate the conduct of his
ancestor Lord Stanhope in the transactions that led to Lord Towns-
hend's dismissal, and has succeeded in this objec(<, and has also
corrected some misstatements in Coxe's account.
mistresses and favourites, whose schemes of avarice and ambition ho
resisted. His temper was impetuous, and his manner of speaking and
writing frank and abrupt, so that if the king was predisposed to take
offence, there would be no lack of opportunity. Lord Sunderland,
who had aspired to be premier on George's accession, and had deeply
resented the precedence given to Townshend in the ministry, joined
the king after a time in Hanover, and was too well disposed to join
with the German clique in undermining Lord Townshend's influence.
Subjects of diSerence between the king and Lord Townshend occurred
after the former's going to Hanover. The king, with Hanoverian
objects, was eager to declare war against Peter the Great of Russia, a
measure which Townshend vehemently resisted. A negociation was
proceeding at the Hague between England, France, and the States-
General, for a treaty to secure the successions to the English and
French thrones, and for the expulsion of the Pretender from France,
which the king and Lord Stanhope in Hanover were anxious to accele-
rate ; and some delays occurred through Lord Townshend, which were
attributed to design, owing to disapproval of the way in which the
treaty was to be concluded. The king was greatly offended at this,
and ordered Stanhope to write a strong reproof to Townshend. He
was however appeased by Townshend's reply, in which he fully vindi-
cated himself from the charge of wilful delay. But though this storm
blew over, another soon succeeded. The king, anxious to continue in
Hanover during the whole winter, had directed Townshend to transmit
to him the sentiments of the cabinet on what was to be done in the
next session, and on the means of carrying on the business of the
country witliout his own presence. Townshend, to gratify the king's
inclination, did not press his return, but strongly urged that a discre-
tionary power should be given to the Prince of Wales. The king's
jealousy of his son took fright at this recommendation ; and it
seemed ,to him to confirm stories which Sunderland had been
assiduously spreading of intrigues carried on by Townshend with the
Duke of Argyll and others for placing the Prince of Wales on the
throne. The king immediately formed the determination of dismissing
Townshend; and it was with much difficulty that Stanhope prevailed
upon him to offer the lord-lieutenancy of Ireland by way of breaking
143
TOWNSHEND, VISCOUNT.
TOWNSHEND, VISCOUNT.
HI
the fall. This offer, conveyed by Stanhope, together with the announce-
ment of his dismissal from the secretaryahip, was indignantly refused.
•'I am highly sensible," Lord Townshend wrote to the king, "of the
honour which your majesty confers on me by condescending to appoint
me lord-lieutenant of Ireland ; but as my domestic affairs do not permit
me to reside out of England, I should hold myself to be totally
unworthy of the choice which your majesty has been pleased to make,
if I were capable of enjoying the large appointments annexed to that
honourable office without doing the duty." (Coxe's ' Memoirs of Sir
R Walpole,' vol. i., p. 191.) This was irony aimed at Sunderland,
visited Ireland. Sir Robert Walpole wrote to Stanhope, who had
urgently solicited his mediation with Townshend, to prevail on him
to accept the lord-lieutenancy — "When you desired me to prevail with
my Lord Townshend to acquiesce in what is carved out for him, I
cannot but say you desired an impossibility ; and 'tis fit you should
know that there is not one of the cabinet council with whom you and
Lord Sunderland have agreed in all things for so many years, but
think that, considering all the circumstances and manner of doing
this, nobody could advise him to accept of the lieutenancy of Ireland.
And be assured that whosoever sent over the account of any
intrigues or private correspondence betwixt us and the two brotliers,
or any management in the least tending to any view or purpose but
the service, honour, and interest of the king — I must repeat it, be
assured, they will be found, pardon the expression, confounded liars
from the beginning to the end." ('Id.,' vol. i., p. 310.) And in
another letter to Stanhope, whose conduct on this occasion was mis-
apprehended, not perhaps unnaturally, by Townshend and Walpole,
the latter made this pointed appeal : — " What could pi-evail on you to
enter into such a scheme as this, and appear to be the chief actor in
it, and undertake to carry it through in all events, without which it
would not have been undertaken, is unaccountable. I do swear to
you that Lord Townshend has no way deserved it of you
Believe me, Stanhope, he never thought you could enter into a combi-
nation with his enemies." (* Id.,' p. 3 1 0.) Stanhope had concurred in
the king's resentment against Tow^nsheud, when he was supposed to be
purposely delaying the French treaty, and had showed his feeling by
immediately tendering his resignation, which the king refused. But
having been satisfied that his suspicions against Townshend on this
occasion had been unjust, he now had borne no other part than to
transmit the king's commands, and to endeavour to conciliate him
towards Townshend, and soften his determination. The king had
conceived a disgust. Stanhope wrote in his first letter on the subject
to Sir Robert Walpole, at Townshend's temper. The falsehoods told
him of Townshend's intrigues with the prince, of which Stanhope
naturally said nothing, but with which there is no evidence to connect
him, drove the king into a fury. And the determination which the
king had come to under the influence of those violent personal feelings
it was impossible to alter. Stanhope wrote to Methuen, who sided
with Townshend and Walpole, though he had been destined to succeed
Townshend: — "If you have any interest or credit with them, for God's
sake make use of it upon this occasion. They may possibly unking
their master, or (which I do before God think very possible) make
him abdicate England, but they will certainly not force him to make
my Lord Townshend secretary." (' Id.') The king's desire to consult
the interests of the Whig party had led him, though with some
reluctance, to adopt Stanhope's suggestion of offering Townshend the
lord-lieutenancy ; and now, when he found the degree of resentment
felt by Walpole and many of the leading Whigs, led him also to keep
the appointment open till his return to England, in the hope that
Townshend might yield. Stanhope saw a gleam of Townshend's
return to his former post if he would first accept the lord-lieutenancy,
and he wrote to Walpole, January 16, 1717 : — " Believe me, dear AVal-
pole, when I swear it to you, that I do not think it possible for all the
men in England to prevail upon the king to re-admit my Lord Towns-
hend into his service, upon any other terms than of complying with
the offer made of Ireland. The king will exact from him this mark
of duty and obedience." ('Id.,' p. 319.) It was not unnatural that
Townshend and Walpole, at a distance from the scene of the intrigues
against them, indignant at the false charges of which they had heard,
and astounded at the strong step to which the king had, without
giving any notice, had recourse, should attribute to Stanhope a share
in the cabal against them ; and such was the opinion of the public.
The effect of Lord Townshend's dismissal, when it was made known,
on the public mind and on the Whig party, was such, that the king
took fright, and on his arrival in England sent Count Bernsdorf to
Lord Townshend to tell him, that having taken away the seals, though
perhaps on false reports and too hastily, he yet could not with due
regard to his own character at once restore them to him, and to beg
Townshend to accept the lord-lieutenancy as a temporary office, to be
exchanged hereafter for another more influential one. Townshend
now yielded, and those who had sided with him in the ministry were
Batisfied. But the union ihus effected did not last long. Stanhope
and Sunderland had acquired an ascendancy with the king, from which
they were not now to be deposed by Townshend and Walpole. These
showed their mortification by cold support in parliament of the minis-
terial measures. On the motions for granting a supply against
Sweden, on the 9th of April 1717, almost all Townshend's personal
friends voted against the ministry, which narrowly escaped a defeat
by a majority of four. The next day Townshend received a dismis-sal
from his office of lord-lieutenant of Ireland. Walpole immediately
tendered his resignation, which, it is said, the king received with so
much surprise and sorrow, that he returned the seals to him ten times
before he would finally accept them. [Walpole, Sie Robert.] The
example of Walpole was followed by Methuen, Pulteney, the secretary
at war. Lord Otfurd, and the Duke of Devonshire.
Lord Townshend now went into opposition, and, like Walpole, is
open to the charge of having out of office opposed principles and
measures which he had previously supported. In the differences
between the king and the Prince of Wales, he and Walpole were now
the friends of the latter. A reconciliation having been brought about
between the king and Prince of Wales, in April 1720, Lord Towns-
hend was admitted a few days after, with the Duke of Devonshire,
Lord Cowper, Walpole, Methuen, and Pulteney, to kiss the king'u
hands ; and received more decided proofs of restoration to the king's
favour by being appointed in June one of the lords justices, on tho
king's going to Hanover, and president of the council. Walpole was
appointed at the same time paymaster of the forces. The breaking
up of the South Sea scheme and the deaths of Lords Stanhope and
Sunderland, led in 1721 to a reconstruction of the ministry, in which
Lord Townshend became again secretary of state, and Walpole also
resumed his old posts of first lord of the treasury and chancellor of
the exchequer. Walpole had now attained to a more influential
position in the country, and was considered prime minister.
Townshend and Walpole had now again complete influence with the
king. Lord Carteret, who was the other secretary of state, beginning
together with Count Bernsdorf, to intrigue against Townshend, did
not find success, as Lord Sunderland had done in former days.
When the king went again to Hanover, Townshend now took care to
accompany him, and Lord Carteret accompanied him also. "The
superior influence of Townshend and Walpole," says Archdeacon
Coxe, " was not solely gained by court intrigues, or by the corruption
of German favourites, and was not prostituted by a preference of
Hanoverian interests to those of England. In the midst of these
cabals, the conduct of the brother ministers was firm and manly,
moving in direct opposition to the king's prejudices and the wishes
of the German junta. Townshend prevented tlie adoption of violent
measures against Russia, proposed by Bernsdorf and seconded by
Carteret, which, if pursued, must have involved England with the
czar; and he exultingly informed Walpole that the king continued
true to his resolution of signing no paper relating to British affairs but
in Lis presence." ('Memoirs of Sir R. Walpole,' vol. ii., p. 166.)
Lord Cartei'et was removed from the secretaryship of state in 1724,
and made lord-lieutenant of Ireland. The Duke of Newcastle, the
brother of Townshend's first wife, succeeded him ; and eventually
became, what Carteret had been, Townshend's rival. There soon
arose also a coolness between Townshend and his other brother-in-
law, and old friend and colleague, Walpole, owing, it is supposed, to
their altered positions and Townshend's jealousy of Walpole's growing
superiority. It was not until 1730 that tho breach between the two
brother ministers, aud Lord Townshend's resignation, took place:
but there were symptoms of a rising misunderstanding as early as
1725, two years before the death of George I. Walpole does not
appear to have been to blame in the beginning.
On Qeorge II.'s accession, in June 1727, Walpole's pre-eminence
was fully established. During this year Townshend had a dangez'ous
illness, which was expected to be fatal ; and when he was supposed
to be dying, Walpole wrote, that he considered him " the bulwark of
the constitution," aud that he trusted " Providence would interfere to
save the man without whom all must fall to the ground." (Coxe's
' Memoirs of Sir R. Walpole,' vol. ii., p. 382.) But Walpole's generous
conduct was destined to be fruitless.
In the year 1729 Walpole and Townshend had become determined
opponents in the ministry, and Walpole, having the support of Queen
Caroline, who was all-powerful with the king, had no difficulty in
always gaining the victory over Townshend. Almost every question
that arose became a subject of dispute. The Duke of Newcastle and
Walpole endeavoured to bring Lord Harrington into the cabinet:
Lord Townshend brought forward a rival candidate in Lord Stan-
hope, afterwards the celebrated Earl of Chesterfield. Lord Towns-
hend's object was defeated. Dr. Maty has related the following
anecdote in his 'Memoirs of Lord Chesterfield' (p. 112): "The firet
London, Sir Robert Walpole took him aside and told him, ' I find you
are come to be secretary of state.' ' Not I,' said his lordship, ' I have
as yet no pretensions, and wish for a place of more ease. But I
claim the garter I am a man of pleasure, and the blue riband
would add two inches to my size.' ' Then I see how it is,' replied Sir
Robert, * it is Townshend's intrigue, in which you have no share ; but
it will be fruitless, you cannot be secretary of state, nor shall you
be beholden for tho gratification of your wishes to anybody but
myself.' " Disputes arose also between Townshend and Newcastle on
strong measures against the emperor, and had obtained the consent
of the king to a despatch directing an invasion of the Austrian
Netherlancfi. He went out of town to Norfolk for a short time, and
li->
TOWNSHEND, RIGHT HON. CHARLES.
TOWNSHEND, RIGHT HON. CHARLES.
14}
ia his absence Newcastle, witla the aid of Wnlpole and the queen, bad
brought the king to approve of a contrary pohcy. Townshend now
determined to resign. Angry words, and even blows, passed between
him and Walpole before he did so. A particular accovint of their
quarrel ia given by Archdeacon Coxe, in hia ' Memoirs of Sir Robert
Walpole,'
Lord Townshend's resignation took placo on the 15th of May 1730.
He retired immediately to his seat at Rainham, and, never again
returning to London, devoted himself to agricultural pursuits for the
remainder of his life. Ho introduced the cultivation of the turnip
from Germany into this country. Lord Chesterfield visited him in
his retirement, to press his coming to London to be present at an
important debate, and Lord Townshend refused, saying that he
remembered Lord Cowper, though a staunch Whig, had been
betrayed by personal pique into voting with the Tories, and he added,
"I know I am extremely warm, and I am apprehensive, if I should
attend the House of Lords, I also may be hurried away by the impe-
tuosity of my temper to adopt a line of conduct which, in my cooler
moments, I may regret." " He left office," says Lord Mahon, " with
a most unblemished character, and — what is still less common — a
most patriotic moderation. Had he gone into opposition, or even
steered a neutral course, he must have caused great embarrassment
and difficulty to his triumphant rival. I'ut he must thereby have
thwarted a policy of which he approved, and hindered measures
which he wished to see adopted. In spite of the most flattering
open arms, he nobly resolved to retire altogether from public life.
He withdrew to his paternal acres at Rainham, where he passed the
eight remaining years of his life in well-earned leisure or in agricul-
tural improvements." (' History of England from the Peace of
Utrecht,' &c., vol. ii., c. xv.)
Lord Townshend died on the 21st of June 1738, in his sixty-third
year. He was an able and honest minister, but his ability and honesty
Were unfortunately uncontrolled by temper or prudent tact. He
was not conspicuous as an orator. Lord Cbesterfield has left a
description of his speaking which is not altogether flattering. " The
late Lord Townshend alw.ays spoke materially, with argument and
knowledge, but never pleased. Why? His diction was not only
inelegant, but frequently ungrammatical, and always vulgar; his
cadences false, his voice unharmonious, and his action ungraceful.
Nobody heard him with patience; and the young fellows used to
joke upon him, and repeat his inaccuracies." ('Letters,' vol. ii.,
p. 318.)
TOWNSHEND, RIGHT HONOURABLE CHARLES, was the
second son of the third Viscount Townshend, by Audrey, only child of
Edward Harrison, Esq., governor of Madras, and grandson of the
subject of the preceding article. He was born in 1725. He entered
the House of Commons in 1747, and very soon gave earnest of his
future distinction. He supported the Pelham administration, and was
selected to move the address on the opening of the session in Novem-
ber 1749, after the full establishment of peace by the treaty of Aix-la-
Chapelle. I'he Marriage Bill, introduced in 1753, was opposed by
Townshend in a speech of singular power and beauty, which, happily
combining humour, argument, and eloquence, fixed his reputation as
a debater. An excellent report of the speech has been preserved, and
is printed in the ' Parliamentary History,' vol. xv., p. 58. Lord Hills-
borough, who replied to Townshend, began his speech by remarking,
" I am very sensible of the danger I am in, when I rise up to speak
after the honourable gentleman who spoke last ; his manner of speaking
is so engaging, there is such a music in his voice, that it pleases the
ear, though it does not inform the understanding : at the same time
he expresses his sentiments in such beautiful terms, is so ingenious in
finding out arguments for supporting his opinion, and states those
arguments in so strong a light, that he is always most deservedly heard
with attention, and even with a sort of prejudice in favour of every-
thing he says." (Id., p. 62.) This is a clear and decisive testimony to
the position which Townshend had now taken in the house, and to that
eloquence, of which Flood, comparing Townshend with Barr6, Conway,
and others, towards the end of his career, observed, " He is the orator;
the rest are speakers." (' Charlemont Correspondence,' p. 27.)
Townshend's speech on the Marriage Bill has been commemorated
by another contemporary, Horace Walpole, earl of Orford. " A second
adversary appeared against the bill. This was Charles Townshend,
second son of my lord Townshend, a young man of unbounded ambi-
tion, of exceeding application, and, as it now appeared, of abilities
capable of satisfying that ambition, and of not wanting that applica-
tion ; yet to such parts and such industry he was fond of associating
all the little arts and falsehoods that always depreciate, though so
often thought necessary by a genius. He had been an early favourite
trade, and in drawing plans and papers for that province ; but not
I'ising in proportion to his ambition, he comforted himself with
employing as many stratagems as had ever been imputed to the most
successful statesman. His figure vvas tall and advantageous, his action
vehement, his voice loud, his laugh louder. He had art enough to
disguise anything but his vanity. He spoke long, and with much wit,
and drew a picture with much humour at least, if not with much
humility, of himself and hia own situation, as the younger son of a
BIOG. DIV, VOL. Vr.
match. ' Were new shackles to be forged to keep young men of abili-
ties from mounting to a level with their elder brothers ? ' " Lord
Orford proceeds to draw a comparison between Townshend and Con-
way, who also distinguished himself on the same side in this debate,
and to speculate on their future careers. " What will be their fatea
I know not, but this Mr. Townshend and Mr. Conway seemed marked
by nature for leaders, perhaps for rivals, in the government of their
country. Tho quickness of genius is eminently with the first, and a
superiority of application ; tho propriety and amiabloncss of character
with the latter. One grasps at fortune ; tho other only seems pleased
to accept fortune when it advances to him. The one foresees himself
equal to everything ; the other finds himself so whenever he essays.
Charles Townsl\end seems to have no passion but ambition ; Harry
Conway not even to have that. The one is impetuous .and unsteady ;
the other cool and determined. Conway is indolent, but can bo
assiduous; Charles Townshend can only be indefatigable. The latter
would govern mankind for his own sake ; the former, for theirs."
(* Last Ten Years of the Reign of George III.,' vol. L, p. 296.)
In the changes in the administration which followed tho Duke of
Newcastle's death in 1754, Townshend received the appointment of a
lord of the Admiralty. On the Duke of Newcastle's resignation in
November 1756, and the formation of a ministry by the Duke of
Devonshire, with Mr. Pitt as secretary of state, Townshend was
appointed to the lucrative post of treasurer of the chamber. There
are some lettei's in the 'Correspondence of Lord Chatham' which
show the importance that was attached at this time to Charles Town-
shend's support, and the trouble taken to secure him (vol. i., pp. 181,
seq.). Townshend demanded the place of cofferer, a lucrative post in
the household. This was already engaged. The treasurership of the
chamber was then offered, and represented as '' in every respect exactly
equal to the cofferer." Lord Bute went to Townshend, and, not finding
him, to Townshend's brother, afterwards Marquis of Townshend, to
press his acceptance of this office, and with the aid of the Prince of
Wales's name, succeeded in satisfying him. This ministry was but
short lived, Pitt resigned in the spring of next year, in consequence
of tho dismissal of Lord Temple, and Townshend resigned also.
Townshend refused offers to join the new ministry, which Lord Walde-
grave had been commissioned to form. After some months of fruitless
negociations the king was obliged to i-eturn to Pitt, and in the ministry
formed by him as premier in June 1757, Townshend resumed his post
of treasurer of the chamber.
In March 1761, Townshend was appointed secretary-at-war. The
next year, Lord Bute's ascendancy having led to the resignations of
Pitt and Lord Temple in the first instance, and shortly aftsr of the
Dukes of Newcastle and Devonshire, an offer was made to Townshend
of the secretaryship of the plantations, which he refused. Mr. Nuthall
writes to Lady Chatham, October 14, 1762 : — " My countryman the
right honourable Charles Townshend was yesterday sent for by the
Earl of Bute, who opened to him this new system, and offered him
the secretaryship of the plantations and board of trade, which he not
only refused, but refused all connection and intercourse whatsoever
with the new counsellor, and spoke out freely. He was afterwards
three times with the king, to whom he was more explicit, and said
things that did not a little alarm. On his coming out of the closet,
Mr. Fox met him and gave him joy : he asked, ' For what ? ' Mr. Fox
replied, * Of your being secretary of state for the plantations.' Mr.
T. answered, 'Don't believe that, sir, till you hear it from me.' Mr. Fox
was struck, and said he was greatly astonished, for he had understood
that this had been settled." (' Correspondence of the Earl of Chatham/
vol. iii., p. 183.) Townshend however supported in parliament the
preliminaries for the peace, but soon after was among the opposition
to Lord Bute's ministry. On Lord Bute's resignation, in 1763, it was
rumoured that Townshend was to be offered the place of first lord of
the plantations. In the fruitless negociations which took place with
Mr. Pitt towards the close of the year, Townshend was one of those
named by Pitt to the king. (' Chatham Correspondence,' vol. iii.,
p. 265.)
Mr. Grenville's Stamp Act, introduced early in 1765, was zealously
supported by Charles Townshend in a speech which elicited from
Colonel Barr^, in reply, one of his most successful parliamentary
efforts. Townshend had concluded with the words, "And these
Americans, children planted by our care, nourished by our indulgence,
protected by our arms until they are grown to a good degree of
strength and opulence, will they grudge to contribute their mite to
relieve us from the heavy load of national expense which we lie
under ?'' " They planted by your care !" cried Colonel Barr^ : "No,
your oppressions planted them in America;" and so he went on, over-
throwing each clause of the peroration. Under Lord Rockingham's
administration, formed in July 1765, Townshend held the place of
paymaster of the forces. It appears from a letter of Mr. Conway's,
who was secretary of state ancl leader of the House of Commons in
to Townshend, and refused by him. Afterwards, with a vacillation
characteristic of him, and by which he acquired the name of the
weathercock, he repented hi.s refusal, and was willing to sacrifice the
superior profits of paymaster for the greater honour of secretary and
147
TOWNSHEND, RIGHT HON. CHARLES.
TOWNSON, THOMAS, D.D.
148
leader. "C. T., with all bis cordiality, fixes conditions to his good
will : 'confidence and the cabinet' were the words a little while ago;
now bo wishes to be ixseful, and the way in which be can be so most is
as loader of the House. I closed at once, with the addition that he
should then be secretary of state too To-day I liave privately
beard that he bas said ia a letter that things were chaaged since he
refused." (' The Companion to the Newspaper,' 1835, p. 365, where
there are several extracts from Conway's unpublished letters.) Towns-
hend, wbo carried his vacillation into his public conduct, and the
effect of whose brilliant talents bas been lessened, both for his time
and for posterity, by the versatility of his politics, now supported the
repeal of the Stamp Act, which he had helped the previous session to
introduce. Shortly after the formation of the Rockingham adminis-
tration, he had been detained in the country by illness, which many
supposed to be a cloak for dissatisfaction with the new airangcments,
and with the position in which he found himself. A pleasant news-
paper skit upon this circumstance has been preserved by Lord
Chesterfield (' Letters,' vol. iv., p, 2<53) :— " We hear that the Right
Honourable Charles Townshend is indisposed, at his house, in Oxford-
shire, of a pain in his side ; but it is not said in which side."
The Rockingham administration died in July 1766, "having lasted,"
as Burke has chronicled it, in his 'Short Account of a late Short
nistration formed by Pitt, now created Lord Chatham, Townshend
was chancellor of the exchequer and leader of the House of Commons.
There had been difficulty, as before, in prevailing upon him to give up
his lucrative post of paymaster : he first said he would do so, and then
said he would not ; but the firmness of Lord Chatham kept him to his
first statement. The letters which passed on the subject between
Lord Chatham, the Duke of Grafton, the king, and Townshend, may
be seen in the 'Chatham Correspondence,' vol. iii., pp, 458-63,
The course of this Chatham administration is well known. Lord
Chatham was soou too ill to transact any business or exercise any con-
trol over his colleagues, who quarrelled with one another, and among
whom Townshend was looked upon as presuming and contumacious.
Townshend insisted, as chancellor of the exchequer, on a tax being
laid on the American ports. If this were not done, he declared, the
Duke of Grafton wrote to Lord Chatham, March 13, 1767, "he would
not remain chancellor of the exchequer." " His behaviour on the
whole," adds the duke, " was such as no cabinet will, I am confident,
submit to." {' Chatham Correspondence,' vol. iii., p. 232.) And on the
same day Lord Shelburne writes to Lord Chatham, — " I was surprised
at Mr. Townshend's conduct, which really continues excessive on every
occasion, till I afterwards understood in conversation that he declared
he knew of Lord North's refusal, and from himself. .... It appears
to me quite impossible that Mr. T. can mean to go on in the king's
service." (Id., p. 235.) The policy of Townshend prevailed, and on
the 2iid of June he introduced into the House of Commons those
unfortunate resolutions imposing duties upon glass, paper, tea, and
certain other articles imported into America, which rekindled rebel-
lion in the colonies, and eventually led to their separation from the
mother-country. This was done under the nominal premiership of
Lord Chatham, the determined opponent of American taxation, but
who was now kept by illness aloof from business, and had not been
consulted. Soon the necessity of constructing a new administration
with an efficient head was perceived, and a negociation between the
Marquis of Rockingham, the Duke of Bedford, and the Duke of New-
castle having failed, it was understood that Charles Townshend was
to be entrusted with the formation of a ministry. When the highest
power in the state was then just within his grasp, he was suddenly
carried away by a putrid fever, on the 4th of September 1767.
The talents and character of Charles Townshend have been embalmed
in a splendid passage in Mr. Burke's celebrated speech on American
his Stamp Act, and the repeal of that act during Lord Rockingham's
ministry, and having come to Lord Chatham's administration, and the
policy of Charles Townshend, so abhon-ent to the tenor of Lord Chat-
ham's principles, he proceeds : — " For even then, sir, even before this
splendid orb was entirely set, and while the western horizon was iu a
blaze with his descending glory, on the opposite quarter of the
heavens arose another luminary, and for his hour became lord of the
ascendant. This light too is passed and set for ever. You understand,
to be sure, that I speak of Charles Townshend, officially the repro-
ducer of the fatal scheme, whom I cannot even now remember without
some degree of sensibility. Iu truth, sir, he was the delight and orna-
ment of this House, and the chai*m of every private society which he
honoured with his presence. Perhaps there never arose in this
country, nor ia any country, a man of a more pointed and finished
wit, and (where his passions were not concerned) of a more refined,
exquisite, and penetrating judgment. If he had not so great a stock
aa some have had, who flourished formerly, of knowledge long
treasured up, he knew better by far than any man I ever was
acquainted with how to bring together within a short time all that
was necessary to establish, to illustrate, and to decorate that side of the
question he supported. He stated bis matter skilfully and powerfully.
He particularly excelled in a most luminous explanation and display
of his subject. His style of argument was neither trite and vulgar nor
subtle and abstruse. He hit the House just between wind and water;
and not being troubled with too anxious a zeal for any matter in
question, he was never more tedious or more earnest than the precon-
ceived opinions and present temper of his hearers required, to whom
bo was always in perfect unison. He conformed exactly to the
temper of the House ; and he seemed to guide, because he was always
sure to follow it There are many young members in the House
(such of late has been the rapid succession of public men) who never
saw that prodigy Charles Townshend, nor of course know what a
ferment he was able to excite in everything by the violent ebullition of
his mixed virtues and failings, — for failings he had undoubtedly ; many
of us remember them ; we are this day considering the eSect of them.
But he had no failings which were not owing to a noble cause ; to an
ardent, generous, perhaps an immoderate passion for fame ; a passion
which is the instinct of all great souls. He woi-shipped that goddess
wheresoever she appeared ; but he paid bis particular devotions to her
in her favourite habitation, in her chosen temple, the House of Com- M
mons He was truly the child of the House. He never thought, ■
did, or said anything, but with a view to you. He every day adapted
himself to your disposition, and adjusted himself before it as at a
looking-glass." r_
Townshend had married Caroline, the daughter and heiress of John, ■
second Duke of Argyll and Greenwich, and widow of the Earl of Dal- Y
keith, eldest son of the Duke of Buccleuch. Just before his death,
while his influence was in the ascendant, he obtained for his wife the
title of Baroness Greenwich. Townshend selected Adam Smith as
tutor and travelling companion for his step-son the yoimg Duke of
Buccleuch [Smith, Adam], having been first led to this choice, we
are informed by a letter of Mr. Hume's, by his admiration of the
* Theory of Moral Sentiments.*
TOWNSON, THOMAS, D.D., was the eldest son of the Rev. John
Townson, rector of Much Lees, in Essex, where he was born in 1715.
After the usual preparatory education, conducted partly at home,
partly at school, he was sent to the University of Oxford, where he
was entered a commoner of Christchurch in March 1733, In July
1735 he was elected a demy (or scholar) of Magdalen College ; in 1736
he was admitted to the degree of B,A. ; in 1737 he was elected a
Fellow of Magdalen; and in June 1739 he commenced M.A. In
December 1741 he was ordained deacon, and in September 1742,
priest, by Dr, Seeker, bishop of Oxford. Immediately after this he
set out, accompanied by Mr. Dawkins, Mr. Drake, and Mr. Houlds-
worth, on a tour through Italy, Germany, and Holland, from which he
did not return till 1745. Having resumed his residence at the uni-
versity, he was in 1746 presented by his college to the living of
Hatfield Peverell, in Essex, which he retained till 1749, when he
resigned it on being presented by Sir Walter Wagstaife Bagot, Bart.,
to the rectory of Blithfield in Staffordshire. This year he was senior
proctor of the university ; soon after bis quitting which office ho was
admitted to the degree of B.D. He resigned his fellowship in January
1751, on being instituted to the living of the lower mediety of Malpas,
in Cheshire, to which be was presented by bis friend Mr. Drake, but
v/hich be did not accept without some reluctance, arising principally
from his unwillingness to leave Oxford.
In 1758, having received, under the will of the Rev, William Bar-
croft, rector of Fairsted and vicar of Kelvedon in Essex, a bequest of
above 8000^., together with his library, he resigned Blithfield, and
having now more leisure, he began to apply himself with greater assi-
duity to literary pursuits in connection with bis profession. The first
work which he finished was an Exposition of the Apocalypse, which m
however was never printed. His first publication was an anonymous "
pamphlet, entitled ' Doubts concerning the Authenticity of the last
Publication of the Confessional, addressed to [Dr. Blackburue] the
author of that learned Work,' 8vo, 1767. This was followed in 1768
by ' A Defence ' of the * Doubts,' and by another pamphlet entitled
' A Dialogue between Izaac Walton and Homologistes ; in which the
Character of Bishop Sanderson is defended against the Author of the ■
Confessional,' ^
Iu 1768 he made a second tour to the Continent with Mr, Drake's
eldest son, Mr. William Drake, of Brasenose College. In 1778 he pub-
lished his principal work, his ' Discoui'ses on the Four Gospels,' 4 to,
which immediately attracted great attention ; and in testimony of the
merit of which the University of Oxford conferred upon the author in
February 1779 the degree of D,D. by diploma. A German translation
of this work appeared at Leipzig, in 2 vols. 8vo, in 1783, In 17S0
Dr. Porteus, then bishop of Chester, bestowed upon Dr. Townson the
archdeaconry of Richmond. In 1783 the divinity chair at Oxford was
offered to him by Lord North, the chancellor, but his advanced time
of life induced him to decline accepting it. He died April 15, 1792.
Dr. Towuson's collected works were published in 2 vols. 8vo in
1810, under the care of Mr. (afterwards Archdeacon) Charton, together
with a Memoir of the author, from which the above facts are extracted.
In addition to the productions that have been mentioned above, this
collection contains some single sermons, and a portion of a treatise on
the Resurrection, entitled ' A Discourse on the Evangelical Histories
of the Resurrection and First Appearance of our Lord and Saviour
Jesus Christ,' a few copies of which, in 4to, had been printed by the
author in 1784, and distributed among his friends. Dr. Townson was
as highly distinguished by the virtues of his i^rivate character aa for
his professional learning and ability.
119
TRAJANUS, MARCUS ULPIUS NERVA.
150
TRADESCANT, JOHN, the name of two naturalists, father and sod,
who lived in England during the seventeenth century. John Tradescaut,
the elder, is generally supposed to have been a Dutchman, but no record
occurs of the time of his birth or of his arrival in England. He does
not appear to have been known to Gcrarde, who wrote his Herbal in
1597; but in Johnson's edition of this work, published in 1633, he is
frequently alluded to : hence Pulteney concludes that ho arrived in
England between these periods, but various minute circumstances that
have come to light render it probable that ho was really an English-
man. A note in that invaluable storehouse of out-of-the-way in-
formation, ' Notes and Queries' (in several of the earlier volumes of
which a great deal of new matter concerning the Tradescauts is
collected), shows that he was certainly resident at Meopham in Kent,
in 1608, there being in the pai'ish register under August 3, an entry of
the baptism of his son John (' Notes and Queries,' vol. v. 266), and the
wick in Sufiblk, in a way that would imply that they were his kinsmen
as well as namesakes. Early in life he had travelled in Europe and Asia,
and he occupied some position in the suite of Sir Dudley Diggs, am-
bassador to Russia in 1618. During a voyage up the Mediterranean, he
made collections of plants in Barbary and on the coasts of the Mediterra-
nean. In 1629 he was appointed gardener to Charles I., having pre-
viously been gardener to the lord-treasurer Salisbury, the Duke of Buck-
ingham, and other noblemen. He died in 1638. He left behind him a
large collection of specimens of natural history, coins, medals, and
* rai'ities,' the first of the kind it is believed foi-med in this country,
and a garden well-stored with rare and curious plants. In the Ash-
molean Library at Oxford is preserved a folio manuscript, entitled
' Tradescant's Orchard, illustrated in sixty-five coloured drawings of
fruits, exhibiting various kinds of the apple, cherry, damson, date,
gooseberry, pears, peaches, plums, nectarines, grape, hasell-nut, quince,
strawberry, with the times of their ripening,' which is supposed to be in
John Tradescant, the Younger, son of the above, was born in
August 1608, and inherited his fathers's taste for natural history. In
the early part of his life he made a voyage to Virginia, and brought
from that country a collection of dried plants and seeds. In 1656 he
published in 12mo a little work entitled ' Museum Tradescantium,' or
'A Collection of Rarities preserved at South Lambeth near London.'
It contaius a descriptive catalogue of his father's museum, which he
had by his own exertions greatly augmented. This museum contained
not only stuffed animals and dried plants, but also minerals, instru-
ments of war and domestic use of various nations, also a collection of
coins and medals. This museum is remarkable as containing one of
the few specimens ever known of the Dodo, a bird now supposed to
be extinct. The catalogue of the museum is accompanied with good
engravings of the two Tradescants, and is sought after by print-
collectors on this account. I'he younger Tradescant was intimate
with most of the celebrated men of his time, and his collection of
natural objects was visited and aided by the most distinguished
persons of the day. In 1650 he became acquainted with Mr. Elias
Ashmolo, who, with his wife, lived in his house during the summer of
1652. The result of this was so close a friendship, that Tradescant,
by a deed of gift, dated December 15, 1657, made over his museum of
natural history to Ashmole, the gift to take effect after his death. He
died April 22, 1662 ; leaving a will in which his museum was be-
queathed to his wife Hester Tradescaut during her life, " and after her
decease to the Universities of Oxford or Cambridge, to which of them
she shall think fit." No mention is made of Ashmole in this will, but
that zealous antiquary was little disposed to forego his claim to the
" closet of rarities." Accordingly we find this entry in bis ' Diary,'
Easter term I preferred a bill in Chancery against Mrs. Tradescant, for
the rarities her husband had settled on me." From the documents of
this Chancery suit (which Dr-. Hamel of St. Petersburg, who had
become interested in the history of the Tradescants, and with rare
patience investigated the obscurer portions of it, has in a visit to
England succeeded in examining), it appears that Ashmole was unable
to produce the deed of gift, which he avers Mrs. Tradescant, to whom
he entrusted it, had "burned or otherwise destroyed;" and Mrs.
Tradescant on the other hand, without apparently denying that such
a deed had been executed, pleaded that by her husband's will, dated
May 4, 1661, all previous dispositions of his property were annulled,
aud the museum left expressly to her alone, with the stipulation
already-mentioned, which she intended to fulfil by bequeathing it to
the University of Oxford. The Lord Chancellor (Clarendon) in his
judgment set aside the bequest, and gave etl'ect to the asserted terms
of the deed of gift, adjudging Ashmolo to " have and enjoy " the
entire contents of the museum, "subject to the trust for the de-
fendant during her life." Mrs. Tradescant was found drowned in the
pond in her husband's garden, Api-il 3, 1678. Ashmole considerably
increased the museum and added to it his library, and having after-
wards bequeathed it to the university of Oxford, it iinj ustly bears the
name of the Ashmolean Museum. [Ashmole, Elias.] The remains
of the garden of the Tradescauts were still at Lambeth in 1749, when
it ^vas visited by Sir W. Watson and described by him in the 46th
volume of the ' Philosophical Transactions.' The widow of the younger
Tradescant erected a singular and handsome tomb to the memory of
father and son, which is still to be seen iu the churchyard at Lambeth :
it was restored by subscription two or three years back. The Tra-
descants introduced a great number of new plants into Great Britain.
Amongst others a species of spider-wort thua brought over was called
Tradescant's Spider-wort. It has since been formed into the type
of a genus with the name Tradescantia, and has a large number of
species.
TRAGUS HIERO'NYMUS (whoso German name wa-s Bock, and
whom the French call Le Boucq), a Gennan botanist of the sixteenth
century. He was born at Heidesbach in 1498. In early life ho
received a good education, and became well acquainted with the
ancient languages. He was appointed master of a school at Zwei-
briioken ; after this he studied medicine, but having embraced the
reformed religion, he became a preacher, and was till his death
minister at Hornbach. His medical studies directed his attention to
the subject of botany, which he pursued with great ardour throughout
botany from the times of Pliny and Dioscorides. The Arabian
writers had satisfied themselves with copying Greek and Roman
observations. Tragus was born at a time when the human mind was
beginning to emancipate itself from the thraldom of authority both in
science and religion. Instead of taking for granted all that had been
wi'itten about plants, he commenced observing for himself. The same
spirit also manifested itself in his contemporaries, Brunfels, Fuchs, and
Gessner ; with these great naturalists he was on terms of intimacy,
and the first result of his labours in botany was published in 1531, in
a work entitled ' Herbarium,' by Brunfels, with the name * Disserta-
tiones de Herbarium Nomenclaturis ad Brunfelsiam.'
In 1539 Tragus published his great work on which his reputation
depends. It was written in German, and entitled ' Neu-ICi-eiiter-
buch vom Unterschiede, Wurkung und Nahmen der Kreiiter, so in
Deutschland wachsen,' folio, Strasburg. In all previous modern works
on botany the plants had been arranged alphabetically, but in this
work Tragus adopted a natural classification, which, whatever may be
its defects, has the merit of being the first modern attempt at the
classification of plants. He divided the vegetable kingdom into three
classes: — 1, wild plants with odoriferous flowers; 2, trefoils, grains,
potherbs, and creeping plants ; 3, trees and shrubs. This classification
is of course exceedingly imperfect; it however served to open the
way to better systems. He commences his work with a description of
the nettle, and for this two reasons are assigned : — 1, That he wished
to teach persons engaged in the practice of medicine not to despise
the meanest plants ; and 2, that the nettle was his family badge. Tho
first edition of this work was published without illustrations, but in
1546 an edition was published containing upwards of 300 wood-cuts.
To Tragus, Fuchs, and Brunfels belongs the merit of having com-
menced the illustration of works of natural history with wood-
engravings. Haller says that he was ' homo jocularis,' and in hie
figures illustrative of their medicinal effects. Thus Pyramus and
Thisbe are stationed at the foot of the mulberry- tree ; ^sop is
demonstrating his innocence under a fig-tree ; and Noah surrounded
by his three sous is chosen as an illustration of the effects of the vine.
Many of the wood-cuts were good, and most of them were copied
into the various herbala that were published in the 16th and 17th
centuries. The descriptions of the plants are short and some-
what obscure ; they were however original, and the structure of plants
was but very imperfectly understood in the time of Tragus. He has
given the Hebrew and Arabic names of the plants, as well as the
Greek and Latin, but in these synonyms he exerted too little care in
the identification of the German plants with those of ancient writers.
Two editions of the engravings of this work with the names of the
plants were published at Strasburg by Trew, in 1550 and 1553, under
the title, * Vivse atque ad Vivum ExpressEC Imagines omnium Herba-
rum in Bock Herbario depictarum Icones solae,' 4to.
1552. This edition has a learned preface Avritten by Conrad Gessner.
It is sometimes spoken of as a separate work of Tragus. It has for
its title, ' Hieronymi Tragi de Stirpium maxime earum quaj in Ger-
manuia nostra nascuntur, &o. libri tres in Latiuam linguam conversi,
interprete David Kyber Argentinensi, Argent.,' 4to. Several editions
of the German book have been published ; the best of these is that of
1695, which was edited by Melchior Sebitz and Nicolas Agerius.
Tragus died at Hornbach in 1554.
TRAJA'NUS, MA'RCUS U'LPIUS NE'RVA, was most probably
born in 62 or 53 a.d., at Italica, the present Alcalh, del Rio, on the
Guadalquivir, not far from Seville in Spain. He was the son of one
Trajan, who was descended from an old Spanish or Iberian family, aud
who is said to have been a consul (Eutropius, viii. c. 2) ; but his name
Trajanus the surname of ' Crinitus,' perhaps because he wore his hair
long, as did his countrymen the Iberians. Trajan the elder having
obtained a command in Asia Minor, went there, accompanied by his
son, who distinguished himself at an early age in the wars against the
Parthians and the Jews. He became consul in a.d. 91, together with
Acilius Glabrio. After he had discharged his function he went to
Spain, and he afterwards commanded the legions on the Lower Rhine.
151
TR A JANUS, MARCUS ULPIUS NERVA.
TRAPP, JOSEPH, D.D.
162
His military talents and hia amiable character made him popular with
the troops : and though we know very little about his early life, we
must suppose that his merits were gi-eat. This we may conclude from
the circumstance that the Emperor Nerva, an old man without issue,
adopted him in a.d. 97, and chose him for his successor, although
there were several relations of Nerva who had perhaps more claims
to the throne than Trajan. But, eays Diou Cassius (Isviii. c. 4), Nerva
was exclusively led in his choice by his care for the welfare of the
empire ; and he considered Trajan's Iberian origin as a matter of
indiflference. Yet Trajan's nomination as Cacear was a new thing in
Koman history, the imperial throne having hitherto been exclusively
occupied by members of the old Roman aristocracy, so that Trajan
was tho first emperor who was born beyond the limits of Italy.
Trajan received tho news of his nomination in Cologne, and three
months later (Aurclius Victor, • Epitome,' c. 12) the death of Nerva,
which took plice on the 27th of Januaiy, 98, made him master of the
Roman empire. On his arrival at Rome the people received him with
great demonstrations of joy, and Trajan soon pi'oved that he deserved
his high station. He appointed distinguished and honest men as
public functionaries ; he curbed the turbulent body of the Prajtorians;
he issued an edict against false accusers, and banished those who were
convicted of this crime to the barren islands of the Mediterranean.
Corn being dear in Rome, he allowed its entrance duty-free, and he
thus won the hearts of the people, while those whom he honoured
with his intercourse were delighted by his affability. Yet the emperor
never forgot his dignity. His virtues and eminent qualities became
conspicuous in tlie first years of his reign, as we may see from the
panegyric of Trajan, which Pliny the younger read in the senate as
early as 100, after he had been made consul. In 103 Pliny, who was
a personal friend of the emperoi", was appointed proconsul of Bithjnia
and Pontus ; and having inquired into the fatate of the Christians, he
recommended them to the emperor, and thus mitigated the persecu-
tions to which they had hitherto been exposed by Piiny himself. The
letters that passed between Pliny and Trajan are the best sources with
regard to the private character of this emperor.
As early as 100 Trajan was engaged in a war with Decebalus, king of
the Dacians ; at the head of a numerous carmy Trajan crossed the
Danube, defeated the enemy, and in 101 took their capital, Zermize-
gethusa (Dion Cassius, Ixviii. c. 9), which was most probably situated
on the Bite of the present village of Varhely, not far from the pass of
the 'Iron Porte,' in Transylvania. In 102 Decebalus was compelled
to purchase peace by the cession of a part of his territoiy ; and on his
with the name Dacicus. Lucius Quiatus and Hadrianus, afterwards
emperor, distinguished themselves in this war. Annoyed by his de-
pendence on Rome, Decebalus violated the peace as early as 104, and
Trajan hastened to the Danube, resolved to finish the war by the
conquest of Dacia. He ordered a bridge to be constructed over the
Danube, which was the largest work of this kind mentioned by the
ancients. According to Dion Cassius it consisted of twenty piers,
150 feet high, 60 wide, and 170 feet apart; the piers were united by
wooden arches. (Dion Cass., Ixviii. c. 13. ed. Reimar, and the note.)
The whole length cf it has been calculated at 4770 Roman feet. If
the statement of Dion Cassius is true, this bridge seems not only to
have served for the passage of the river, but the immense height of
the pillars, of which scarcely more than seventy feet can have been
under water, leads to the supposition that it was at the same time a
strong fortification desthied to command the navigation. At a height
of eighty feet above the water, soldiers were protected against the
missiles of the Dacian ships, while the fleet of the enemy in passing
that bridge ran the ri^k of destruction. This bridge was either at
Szernccz in Hungary, or five leagues above the junction of the Alt
with the Danube, in Wallachia, not far from Nicopolis, where ruins of
the Roman colonics of Komula and Castra Nova, and a Roman road,
•which is pretty well preserved, still exist. The war proved fatal to
Decebalus. Defeated wherever ho encountered the Romans, he
killed himself in despair (105); and in 106 all Dacia was conquered
and made a Roman province by Trajan, who sent there numerous
colonists. Trajan returned to Rome in the same year, and celebrated
hia second Dacian triumph. In memory of his victories over the
Dacians a column was erected, in- 114, by tho architect ApoUodorus,
on the Forum Trajani, which, having been preserved from ruin, is still
admired as one of the finest remnants of ancient art. The column
was 144 Roman feet high, according to Eutropius (viii. c. 2). Another
column, which is likewise extant, was erected in honour of Trajan by
the inhabitants of Beneventum after his victories over the Parthians.
After the conquest of Dacia, eight years of peace elapsed, which
with beautiful buildings; he also founded a library, the Bibliotheca
Ulpia, and an institution for the education of poor children of Italian
parents. (Fr. A. Wolf, ' Von einer milden Stiftung Trajan's,' Berlin,
ito, 1808.) In 114 Trajan left Rome to lead hia armies against the
Parthians.
In tho Asiatic part of the empire peace had already several times
been disturbed, principally by the Arabs, who however were subdued
by Cornelius Palma, the proconsul of Syria, who, in 105, conquered
Arabia Petrsea, and made it a Roman province. Some years later
Cosrhoes, or Khosrew, king of the ParthiauB, deprived Exedares, king
of Armenia, of his dominions, and created his brother Parthamaspes,
or Parthamasiris, king of Armenia. The Romans havuig always been
anxious to maintain their influence in Armenia — tho independence, or
rather dependence of this country on Rome was necessary for the
security of the East — Trajan declared war against Khosrew. The
Parthians were defeated, and in one campaign 1'rajan conquered
Mesopotamia and delivered Armenia. He took up his winter-quarters
at Antioch, relieved the Syrians, who were suffering from the conse-
quences of a violent earthquake, and in the following year, 115, opened
a new campaign. He crossed tho Tigris, in the province of Adiabeue,
and the Parthians having again been defeated, he took the towns of
Nisibis, Edessa, Ctesiphon, and Seleucia ; Babylonia, Assyria, Armenia,
and Mesopotamia became Roman provinces; a rebellion of the Jews
in Ezypt and Cyrenaica was quelled ; Khosrew was deposed, and his
brother Parthamasiris was put by Trajan on the throne of Parthia.
After the conquest of these extensive provinces Trajan sailed with his
fleet on the Tigris to the Persian Gulf, and took up his winter-quarters
in the town of Spasinus. When he had reached the sea, the example
of Alexander suggested to him the idea of conquering India, but
remembering his advanced age, he renounced that scheme. (Dion
Cassius, Ixviii. c. 29.) In 117 Trajan made an incursion into Arabia,
and ordered a fleet to be kept on the lied Sea. Suffering from dropsy,
he set out for Rome, but he died on his way at Selinus, a town in
Cilicia, in the month of August 117, at the age of sixty-three years
nine months and four days, according to Eutropius (viii. c. 2).
Trajan was one of the gieatest emperors of Rome. He is said to
have been addicted to women and wine ; but his public character was
without reproach, except his passion for warfare and conquest. How-
ever he undertook no war for frivolous motives. He deserved the
title of ' Optimus,' which the senate conferred on him. The memory
of hia name lasted for centuries, and two hundred years later the
senators used to receive the emperors with the acclamation, " Be
happier than Augustus, and better than Trajan ! "
The body of Trajan was transported to Rome, where it was deposited
under the Columna Trajani. His successor was Hadrian.
(Aurelius Victor, De Ccesaribus, c. 13; Epitome, c. 13; Sextus
Rufus, Brcviarium, c, 8, 14, 20; H. Francke, Zur Geschichte Trojans
und seiner Zeiigenossen, 1837, is a very valuable book.)
I
Coin of Trajan, witli Reverse.
British Museum. Actual Size. Bronze.
Reverse of Coin of Trajan.
British Museum. Actual Size. Bronze.
TRAPP, JOSEPH, D.D., was born at Chcrriogton in Gloucester-
shire, in November 1079. He was entered at Wadham College,
Oxford, in 1695, took his degree of Master of Arts in 1702, and was
chosen a Fellow of his college in 1704. In 1708 he was appointed
the first professor of poetry at Oxford, and at the expiration of his
term of office published the lectures he had delivered on the subject,
under the title of ' Proelectiones Poeticse,' in 3 vols. 8vo, 1718. Dr.
Trapp was warmly attached to the Tory party in the government, and
took an active part in the political disputes of the time. He acted as
manager for Dr. Sacheverell on his trial in 1710, and upon the Tories
coming into power in the autumn of the same year he was appointed
chaplain to Sir Constantine Phipps, lord chancellor of Ireland. He
was afterwards appointed chaplain to Lord Boliugbroke, and wrote
several papers in the ' Examiner ' in defence of his administration.
He obtained the living of Dauntsey in AViltshire in 1720, but
resigned it in the following year upon obtaining the vicarage of the
united parishes of £!hrist Church, Newgate-street, and St. Leonard's,
153
TRAVERS, JOHN.
TREDIAKOVSKY, VASSILI KIUILOVICH.
IM
Forster-lano, Loudon. la 1733 he was presented to the living of
Harliugtoa in Middlesex by Lord Boliugbroke, and in the following
year was elected ono of the joint lecturers of St. Martin's-in-the-Fields.
He died November 22, 1747, at the age of sixty -eight, and was buried
in llarlingtou church.
Dr. Trapp was a hard student, and published numerous works,
which acquired for him considerable reputation in his own day, but
would now scarcely repay the trouble of reading. One of his best
works is said to be ' Notes upon the Gospels,' first published in 17-17.
He published several sermons, which he preached upon various occa-
Bions, and also numerous pamphlets against the Whigs, but these
generally appeared without his name. His translation of Virgil into
blank verse, published in 1717, in 2 vols. 4to, generally succeeds in
giving the meaning of the original, but is a complete failure as a
work of art. His Latin poetry is said to be better than his English ; he
published a Latin translation of ' Anacreou ' and of Milton's ' Paradise
Lost.'
TRAVERS, JOHN. The author of musical compositions so popu-
lar, elegant, and charming as ' Haste, my Nanette,' ' I, my dear, was born
today,' ' When Bibo thought fit,' 'Soft Cupid,' is fairly entitled to a
few lines in our biographical department, though his life was void of
any remarkable incident. He was educated first in St. George's
Chapel, Windsor, afterwards under the celebrated Dr. Greene
[Gueene]. About the year 1725 he followed Kelway as organist of
St. Paul's, Covent Garden, and subsequently filled the same situation
also at Fulhani. In 1737 he was appointed organist to the Chapels
Royal. He died in 175S, and was succeeded iu the latter office by
Dr. Boyce.
Travers composed much cathedral music, but except an anthem,
' Ascribe unto the Lord,' and a ' Te Deum,' his productions for the
church have fallen into disuse. We will only add that Dr. Burney's
notice of him is neither discriminating nor just.
TRAVERSA 'RI, AMBRO'GIO, called also Ambrosius Camaldu-
lensis, a great scholar and public character of the 15th century, was
born in the village of Patico near Forli, in 13S6. Some assert that his
family was a branch of the Traversari who once ruled over Ravenna. At
fourteen years of age Ambrogio entered the order of the Camaldulenses
at Florence. He is said to have studied Greek under Chrysoloras,
and afterwards under Demetrius Scarani of Constantinople, who
became a Camaldulensian monk at Florence about 1417. Traversari
became a good Greek and Latin scholar, and applied himself entirely to
classical studies till 1431, when he was made general of his order. He
was intimate with Cosmo de' Medici, Niccolo Niccoli, Francesco
Barbaro, Leonardo Giustiuiaui, and other learned men and patrons
of learning of that age. Wiien Cosmo and his brother Lorenzo the
elder were in banishment at Venice, in 1433, Traversari, who was in
that town, often visited them, and he speaks of them iu his lettei-s with
esteem and afiection. He instructed several pupils, and among others
Giannozzo Manetti, v.'ho became a distinguished scholar. Traversari
travelled much for the afiuirs of his order, and he collected in his
travels materials for his ' Hodajporicon,' which is a description of
what he had seen, containing many particulars concerning the literary
history of that time, and the various libraries then existing in Italy.
The ' Hodajporicon ' was first edited at Lucca by Bartolini, in 1681.
He also collected valuable manuscripts which helped Cosmo to form
the public library in the convent of St. Marco, together with the
collection of Niccolo Niccoli and those of Peruzzi and Salutati. In
1435 Pope Eugenius IV. sent Traversari to the stormy council of
Basel, where he exerted himself with much ability in favour of Euge-
nius, and was instrumental in wiimiug over to the pope's party the
learned Cardinal Cesarini, the president of the council, who suddenly
left Basel and repaired to Ferrara, whither the pope had transferred
the council in January 1438. Traversari was sent from Basel into
Germany on a mission from the pope to the Emperor Sigismund, and
on returning to Italy he was deputed to Venice to receive the
Emperor Palacologus and the patriarch of Constantinople, and to con-
duct them to Ferrara, from whence the council was soon after
removed to Florence. 'Traversari acted in that assembly^as interpreter
between the Greeks and the Latins, and he had the satisfaction of
seeing the reunion of the two churches. He soon after died at
Florence, in October 1439. He left Latin translations of many Greek
works, especially of ecclesiastical writers, such as Chrysostom, Basi-
lius, Athanasius, Ephrem Syrus, Johannes Climachus, and others, of
which, as well as of other inedited works of Traversari, his biographers
Mehus, Cateni, Ginanni, and Zeuo have given catalogues. His trans-
lation of the Lives of Diogenes Laertius, dedicated by him to his
friend Cosmo de* Medici, was printed at Venice iu 1475. Some of his
Orations delivered in the council of Basel are also printed. His nume-
rous letters were collected by Father Canneti, and published, with
the addition of learned notes and a biography of Traversari, by
Lorenzo Mehus : ' Traversarii Ambrosii Epistolse Latinse et aliorum
ad ipsum, curante P. Canneto, cum Ambrosii Vita, studio L, Mehus,'
2 vols, fol., Florence, 1769, an important work for the literary history
of Italy during the 14th and loth centuries.
TREDGOLD, THOMAS, was born in the little village of Brandon,
about three miles west of the city of Durham, on the 22nd of August
1788. At an early age he was sent to a small school in his native
village, where he received what must have been a very limited edu-
cation, as he says in the preface to his first publication that he had
written that work " without the advantage of any other education
than that of which my own industry had made me master." At the
age of fourteen he was apprenticed to a cabinet-maker at Durham for
six years, during which period he was i)articularly noticed for hig
attention to business and his devoting all his leisure hours to books
and mathematical or architectural studies. He informed the writer
of this notice that, instead of going to see the races, as apprenticeB
were then allowed to do in the afternoons of the race-days, he taught
himself perspective.
Soon after the expiration of bis apprenticeship, in 1808, he went to
work as a journeyman carpenter and joiner in Scotland, where he
remained for five years, in no way distinguished from his fellow-work-
men except by his continued life of study. It was during these years
that, by depriving himself of the necessary hours of repose, and not
taking that relaxation which the human frame requires, he impaired
his naturally weak constitution. He rose early, hastily took his meals,
and sat up late, in order that every spare moment might be given to
the acquirement of knowledge, while the chief hours of the day were
spent in laborious manual employment. On leaving Scotland he
repaired to London, where he entered the office of his relative William
Atkinson, Esq., architect to the Ordnance, in whose house he lived for
six years, and remained in his service some years after quitting his
house. At this time it may be said that his studies combined all the
sciences connected in any degree with architecture and engineering;
and in order that he might be able to read the best scientific works on
the latter subject, he taught himself the French language. He also
paid great attention to chemistry, mineralogy, and geology, and per-
fected his knowledge of the higher branches of mathematics. Before
the- publication of his first work he had occasionally contributed
articles to several periodical publications, and he continued to do so for
some time afterwards. These contributions extend over a wide range
of subjects, comprising papers on the elasticity of air; the velocity of
sound ; the causes, laws, &c., of heat ; gases ; the nature of curves ; the
flexure of astronomical instruments ; and the principles of beauty in
colouring. They are chiefly to be found in Tilloch's ' Philosophical
Magazine,' Thomson's ' Annals of Philosophy,' &c., and besides these
he was the author of several articles in the ' Encyclopaedia Britannica.'
In the year 1820 he published his valuable work ' The Elementary
Principles of Carpentry, a treatise on the pressure of beams and
timber frames, the i-esistance of timber, the construction of floors,
roofs, centres, and bridges.' This work contains many practical rules
and useful tables, and is illustrated by 22 platen. It was printed in
quarto, and went through a second edition in 1828. His essay on the
'Strength of Cast Iron,' published in 1821, reached a second edition
in 1824, and a third in 1831.
Before the appearance of his next work, owing to the great increase of
his private business and literary labours, he resigned his situation in Mr.
Atkinson's office, and in 1823 commenced practice as a civil engineer
on his own account. In 1824 he published his ' Principles of Warming
and Ventilating Public Buildings, Dwelling-Houses, Manufactories,
Hospitals, Hothouses, Conservatories, &c.,' which was so favourably
received that a second edition was very soon required. In the course
of the following year appeared his ' Pi'actical Treatise on Railroads
and Carriages,' which was immediately followed by a pamphlet
and entitled ' Remarks on Steam Navigation, 'and its Protection,
Regulation, and Encouragement.' This letter, which contained many
valuable suggestions for the prevention of accidents, has been for
some time out of print. The last important work published by Tred-
gold was a thin quarto volume, with numerous illustrations, entitled
' The Steam-Engine,' containing an account of its invention and pro-
gressive improvement, with an investigation of its principles and the
proportion of its parts for efficiency, strength, &c. The first edition
came out in 1827, and so highly was it appreciated that when it was
nearly sold out the copyright was purchased by its present possessor
at a very much higher price than the author originally received for it.
A posthumous edition, greatly extended by the contributions of
several scientific men, especially in the department of steam-navi-
gation, was published in 1838. This beautiful edition is in two large
4to volumes, illustrated by 125 plates and numerous wood-cuts. It
was edited by W. S. B. Woolhouse, and a portrait of Tredgold is pre-
fixed to the first volume. Mr. Tredgold died on the 28th of January
1829, in his forty-first year, completely worn out by his devotion to
study. He left, besides a widow, three daughters (of whom only one
survives) and a sou, who was brought up to his own profession, and
inherited his father's abilities, as well as, unfortunately, his delicate
constitution. He was engineer in the Office of Stamps of the East
India Company at Calcutta, where he died in April 1853.
TREDIAKOVSKY, VASSILI KIRILOVICH, a Russian poet of
great but unfortunate celebrity, was born February 22nd, 1703. The
place of his birth is not stated, but he is said to have received his first
education in a school kept by a foreigner at Archangel, where he
attracted the notice of Peter the Great, who, visiting the school, and
ordering the boys to be drawn up for his inspection, after attentively
looking at Trediakoveky, exclaimed, "He will prove a most capital
journeyman in his profession, but no master in it ! " in allusion to
which incident the poet remarks— "The emperor was exceedingly
IBS
TREMBECKI, STANISLAW.
TRENCHARD, JOHN.
156
shrewd, but waa greatly mistaken in bis opinion of myself." On leaving
the school at Archangel he studied at Moscow; and then, by tho
liberality of Prince Alexander Kurakiu, was enabled to visit France,
England, and Holland, for the purpose of completing hia education.
While at Paris he attended RoUin's lectures, and made himself master
of some of the modern languages. In 1730 he returned to Russia, in
1733 was appointed secretary to the St. Petersburg Academy of
Sciences, and in 1745 was made professor of eloquence on that office
being first created. He died August Cth, 1769. Without talent for
any one department of literature, Trediakovsky attempted all, from
idyls and fable to tragedy and epic or heroic poetry. Of the last-
mentioned kind is his * Telemachida,' which is a versified paraphrase
of Fc'ndlon's ' Telemachus,' a production so dull that Catherine II.
used to inflict the task of getting a hundred lines of it by heart as a
penalty upon those who infringed the rules established for her private
parties in tho Hermitage. Numerous as they were, his own poetical
productions were but the smaller portion of his literary labours ; for
ho translated several historical works, and among others RoUin's
'Ancient History,' in 26 volumes, twice over, the manuscript of the
first translation having been destroyed by fire ; than which there is not
perhaps a more singular instance of literary industry and perseverance
upon record.
(Bantiesh-Kamensky, Slovar DostopamiatniJch Liudei.)
TREMBECKI, STANISLAW, one of the best Polish poets of the
age of Stanislaus Augustus, was born about 1724, in the district of
Cracow. Notwithstanding his eminence as a writer, and that during
the greater part of his long life he moved in the higher circles of
society, very few particulars have been preserved or collected respecting
him. In his youth he spent many years in visiting various parts of
Europe, and resided for a considerable time at the court of Louis XV.
Afterwards ho was for a long time at tho court of Stanislaus, where he
held the post of chamberlain. Later in life he withdrew almost
entirely from society, rarely seeing any strangers, although he resided
in the family of Felix Potocki at Tulczyn. At one time he had been
remarkably abstemious, never touching either animal food or wine for
thirty years, on which account Stanislaus used to call him his Pythago-
ras. Latterly he abandoned that rigorous system, which however does
not seem to have had much influence upon his temperament, for he is
said to have been engaged in no fewer than thirty duels, all of them
arising out of some afl'air of gallantry, and in every one of which he
came oflF conqueror. He died Dec. 12, 1812, after very little previous
indisposition, at nearly ninety years of age. Among his poetical
works, all of which exhibit great mastery of style and beauty of lan-
guage, that entitled 'Zofijowka' is considered his chef-d'oeuvre. This
production belongs to a species of poetry now in little esteem, it being
a description of the gardens at Zofijowka, an estate in the Ukraine
belonging to the Potocki family ; but though the subject itself is not
of the highest order, it is treated with great ability, and the whole
abounds with striking beauties ; nor is the reader's admiration at all
lessened by its having been written when its author was between tho
age of seventy and eighty. The work however which would probably
have most of all contiibuted to his reputation, namely, his ' History of
Poland,' has never seen the light. The manuscript, consisting of two
hundred sheets, was given in trust by him to a friend, that it should
not bo published until after his death ; but what became of it has not
been ascertained. There is a portrait of Trembecki prefixed to the
two volumes of his poems, forming a part of Bobrowicz's ' Biblioteka
Klassykow Polskich,' from which work tho account here given is
derived.
* TRENCH, REV. RICHARD CHENEVIX, Dean of Westminster,
is tho son of Richard, brother of the first Lord Ashtown, by Melesina,
grand-daughter of Dr. Richard Chenevix, formerly Bishop of Waterford.
He was born September 9, 1807, and graduated at Trinity College,
Cambridge, in 1829, without obtaining honours however either in
classics or mathematics. Having taken orders, he served a country
curacy. His name first became known as a poet in 1838, whilst
holding the incumbency of Curdridge, a chapelry in the parish of
Bishop's Waltham in Hants, by the publication of two volumes of poems,
written in something of the simple style of Wordsworth. They were
respectively entitled ' Sabbation, Honor Neale, and other Poems,' and
' The stoi-y of Justin Martyr.' Attracting tho favourable notice of the
press, these volumes were shortly afterwards followed by his ' Geuo-
Teva,' ' Elegiac Poems,' and ' Poems from Eastern Sources.' In 1841
Mr. Trench resigned the charge of Curdridge, and became curate to
Archdeacon (now Bishop) Wilberforcc at Alverstoke, near Qosport ; in
1845 he was presented by Lord Ashbui-ton to the rectory of Itchen-
Stoke near Alresford ; and on Archdeacon Wilberforco's promotion to
the see of Oxford, he became his examining chaplain. In 1846 and
1846 ho was Hulsean lecturer at Cambridge, and for a short time
also one of the select preachers of the University. His chief publica-
tions during the last few years are : — ' Notes on the Miracles ; ' * Notes
on the Parables;' 'Lessons in Proverbs;' all of which have been
more than once reprinted; 'The Sermon on the Mount, illustrated
from St. Augustine;' 'Sacred Latin Poetry;' 'Synonyms of the New
Testament;' ' St. Augustine as an Interpreter of Scripture;' and a
remarkably useful treatise on the 'Study of Words,' being the
Bubstance of some lectures delivered to the Diocesan Training College
at Winchester.
In 1847 Mr. Trench was appointed theological professor and
examiner at King's College, London, and more recently one of the
examinere for engineer and artillery appointments at Woolwich. In
1852, he was an unsuccessful candidate for the representation of the
archdeaconry of Winchester in convocation, the revival of whoso
active powers he is understood to advocate. In 1856, on the death of
the late Rev. Dr. Buckland [Buckland, Rev. William], he was nomi-
nated by Lord Palmerston to the deanery of Westminster, as a token
of the general appreciation of his services to the cause of religion,
education, and literature.
TRENCHARD, SIR JOHN, Knight, a secretary of state in the
reign of William III., was born in 1650, and was the second son of
Thomas Trenchard, Esq., of Wolverton in Dorsetshire, the then head
of the ancient and wealthy family of the Trencharda. Anthony ii
Wood gives the following account of Sir John Trenchard's birth and
education : " was borne of puritanical parents in Dorsetshire, became
probationary fellow of New College in a civilian's place an. 1665, aged
fifteen years or more, entered in the public library as a student in the
civil law, 22nd October, 1668, went to the Temple before he took a
degree, became barrister and councillour." ('Athenas Oxonienses,'
vol. iv., p. 405, Bliss's edition.) The account characteristically pro-
ceeds, " busy to promote Oates his plot, busy against papists, the
prerogative, and all that way." Trenchard was elected member for
Taunton in Charles II.'s third parliament, which met on the 6th
March, 1679, and was dissolved on the 12th of July in the same year.
Anthony h, Wood erroneously states that ho was first elected in the
succeeding parliament, which, having been called on the 1st October,
1 679, was not allowed to assemble until the same day and month in 1680.
In this last-mentioned parliament Trenchard took a prominent part in
support of the Exclusion Bill, and was generally a zealous member of
the opposition party. He was among those apprehended in 1683, on
the suspicion of the Protestant plot, of which Lord Russell and
Sydney were made the victims. It was told against him that he had
engaged to raise a body of men from Taunton. He denied this on
examination, and Lord Russell also denied all knowledge of it ; but
he was committed to prison. " One part of his guilt," says Burnet,
"was well known : he was the first man who had moved the exclusion
in the House of Commons : so he was reckoned a lost man" (' History
of His Own Time,' vol. ii., p. 357, 8vo, ed. 1823). He was afterwards
however discharged from prison for want of a second witness against
him. (Evelyn's 'Diary,' vol. iii., p. 106.)
After the accession of James II., Trenchard engaged to support the
duke of Monmouth in his foolish invasion, and on the almost im-
mediate failure of the duke's attempt he fled into France. (Dalrymple's
'Memoirs of Great Britain and Ireland,' vol. i., p. 173.) He is said to
have been dining with his relative, Mr. W. Speke, at Ilminster, when
he received intelligence of the defeat of the duke of Monmouth's army
at Sedgemoor ; he immediately mounted his horse and advised Mr.
Speke to do the same ; he succeeded in making his way to Weymouth,
where he took ship for France ; and tho story goes on to say, that at
the moment ho was embarking, his friend Mr. Speke was hanging
before his own door at Ilminster (Burke's 'History of the Com-
moners,' vol. iv., p. 78). He remained abroad till things had ripened
for the Revolution of 1688.
Trenchard was member for Dorchester in the convention parliament
which placed William and Mary on the throne. His services to
William were rewarded by his being made first, serjeant, then chief
justice of Chester and a knight, and lastly, in the spring of 1693,
secretary of state. He received this last appointment at the same
time that Somers was elevated from the attorney-generalship to be
lord keeper; and these two appointments were held of great im-
portance, as being signs of William's desire to return to the Whigs,
from whom he had for a time alienated himself. In the spring of the
next year Lord Shrewsbury returned to the other secretaryship of
state, and the fgovernment was made completely Whig. Sir John
Trenchard died on the 20th of April, 1695.
Opposite characters have been drawn of him by Anthony h Wood
and Bishop Burnet. The former calls him " a man of turbulent and
aspii'ing spirit." Burnet's character of him is as follows : " Ho had
been engaged far with the Duke of Monmouth, as was told formerly.
He got out of England, and lived some years beyond sea, and had a
right understanding of affairs abroad. Ho was a calm and sedate
man, and was much more moderate than could have been expected,
since he was a leading man in a party. He had too great a regard to
the stars and too little to religion." The last feature in the character
which Burnet has drawn is illustrated by a story of Wood's. "An
astrologer told him formerly that he should such a year be im-
prisoned, such a year like to be hanged, such a year be promoted to a
great place in the law, such a year higher, and such a year die, which
all came to pass, as he told Dr. Gibbons on his death-bed."
TRENCHARD, JOHN, a political writer of some celebrity in his
day, was bom in 1662, He was a member of a junior branch of the
same family as the subject of the preceding article, and was the eldest
son of William Trenchard, Esq., of Cutteridge in Dorsetshire, by Ellen,
daughter of Sir George Norton, of Abbots Leigh in Somersetshire. On
Sir George Norton's death in 1715, Mr. Trenchard, his grandson,
inherited his property.
The writer of the life of Trenchard, in the 'Biographia Britannica
\
157
TRENCK, BAHON FllANZ VON.
TRENCK, BARON FREDERIC VON DER.
158
has fallen into the error of making him the son of Sir John Tren-
chard, to whom he was but distantly related. The actual degree of
relationship may be seen iu Burke's * History of the Commoners,' vol.
iv., pp. 78, 79. This error has led to others. For instance, the
■writer represents him as having been born in 1669, instead of
1662, Sir John Trenchard himself having been born in 1650. These
mistakes have been copied in Chalmers's ' Biographical Dictionary ' and
tho * Biograpliie Universelle."
Mr. Trenchard was educated for the law, and was called to the bar.
But his fortune not requiring that he should follow a profession, he
left tho bar for what was to him the more congenial pursuit of
politics. The author of tlie Life in the 'Biographia Britannica' says,
" By tho decease of an uncle, and a marriage to a gentlewoman with a
considerable fortune, he came into the possession of a good estate, and
the prospect of a much better, which also fell into his hands on the
demise of his father in 1695, whom he succeeded likewise in the
House of Commons, being elected a burgess for Taunton in 1695." A
great deal of this is incDrrect. Sir John Trenchard died in 1695, but
Mr. Trenchard's father did not die till 1710. Mr. Trenchard was
elected for the parliament that met in 1695, but sat, not for Taunton,
but for Wareham. And it is probable that the account of the fortune
acquired by marriage, and by the death of an uncle, is a mistake
arising out of Mr. Trenchard's inheriting, after his father's death,
from his maternal grandfather. Sir George Norton.
In 1698 Mr. Trenchard published, in conjunction with Mr. Moyle, a
pamphlet entitled ' An Argument showing that a Standing Army is
inconsistent with a Free Government, and absolutely destructive to
the Constitution of the English Monarchy.' The question of a standing
army being at that time seriously agitated, this pamphlet is said to
have produced a considerable effect. It was followed almost im-
mediately by *A Short History of Standing Armies iu England.' In
1692 Mr. Trenchard was chosen by the House of Commons one of
seven commissioners for taking an account of the forfeited estates iu
Ireland; and he was one of the four who signed the report including
the pi'ivate estate, or that which had belonged to James II. in right
Orkney. A warm debate arose out of this report in the House of
Commons, which is to be read in the * Parliamentary History.' The
report was approved of by the House, but gave great offence to the
king.
In 1709 Mr. Trenchard published * A Natural History of Supersti-
tion;' 'Considerations on the Public Debts ; ' and 'A Comparison of
the Proposals of the Bank and South Sea Company.' He published,
in 1719, two additional pamphlets entitled ' Thoughts on the Peerage
Bill,' aad 'Reflections on the Old Whig.' In 1720 he began, in con-
junction with Mr. Thomas Gordon, a Scotchman, whom he had taken
some time before into his house, and employed as an amanuensis, .i
series of letters on political qusstions, under the signatures of Cato
and Diogenes, which appeared first in the London, and then in tho
British, Journal; and in the .same year; in conjunction with the same
gentleman, ho began a paper called the 'Independent Whig,' which
was devoted to the subjects of religion and church government.
[GoiiDON, Thomas.] These two series of letters went on till 1723, on
the 17th of December in which year, Mr. Trenchard died.
After Mr. Trenchard's death, Mr. Gordon collected Cato's letters,
and published them in 4 vols. 12mo. In the preface to the Work, he
has eketched the character of his friend and benefactor, justifying his
eulogy by saying "that he has set him no higher than his own great
abilities and many virtues set him ; that his failings were small, his
talents extraordinary, his probity equal to his talents, and that he was
one of the ablest and one of the most useful men that ever any couati-y
was blessed withal." Mr. Gordon also published, after Mr. Tren-
chard's death, the papers which had appeared of the ' Independent
Whig,' in 2 vols. 12mo; and at the end of the second volume is
printed a long Latin inscription on Mr. Trenchard's tomb, which had
proceeded from Mr. Gordon's pen. This inscription is printed also in
the notes to the life in the ' Biographia Britannica.' Mr. Gordon con-
tinued the ' Independent Whig' after the death of his coadjutor, and
Whig,' and ' Cato's Letters,' have both passed through several editions.
They both excited much interest when they were first published and
for some time after; but are now little read or known.
Mr. Trenchard had married a daughter of Sir ^Villiam Blackett, of
Northumberland, but had no children. Of his widow we are told,
that, " finding Mr. Gordon very useful in managing her aflixirs, she
continued him in her service, was much pleased with his company,
and, having paid a decent tribute of tears to the memory of her
deceased husband, entered some time after into a second mai-riage
with this ingenious friend and companion, who had several children
by her." (Biogra-phia Britannica.)
TRENCK, BARON FRANZ VON, was born at Reggio in Calabria,
on the Ist of January 1711. His father was a general in the Austrian
service, and took him_ when only eleven years old to serve in the war
against Spain. At this tender age he was present and actually fought
at the battle of Melazio. He was afterwards sent to the military
academy at Vienna, and having passed his examination with great
distinction, he was appointed corne't in the regiment, Palfy. His extra-
ordinary physical strength, united with an uncommon degree of ferocity,
manifested itself very early, and brought him into many difficulties.
When only seventeen, his father having refused to supply him with moro
money for his extravagances, he applied to a farmer in the neighbour-
hood, and upon receiving a refusal there also, he cut the man's head
off. This affair was hushed up with great difficulty, and he waa sent
to Russia, where by his military talents and dauntless courage he soon
gained the friendship of Marshal Miinnich, and was made captain of
attacked a whole Turkish regiment near Bucharest, contrary to the
express orders of his colonel, with his small troop, and gained a
decided victory. Upon his return the colonel reprimanded him for
his disobedience ; he answered by a blow, which felled his superior
officer to the ground. For this offence he was sentenced by a court-
martial to be whipped out of the regiment, a punishment at that
period still inflicted in Russia upon commissioned officers. While he
waa awaiting the execution of this sentence in his tent, he heard that
a brisk engagement with the Turks was taking place, and Marshal
Miinnich being near, he called out to the marshal, and asked him if
he would pardon him, provided he brought back within an hour three
Turks' heads. The marshal assented, and Trenck immediately leaped
upon the first horse he saw, galloped into the midst of the enemy, and
returned to the camp within half an hour with four Turks' heads
suspended from the pommel of his saddle. But shortly after he was
sentenced to death for a still greater violation of discipline, and it was
only through Miinnich's influence that his sentence was commuted
first into banishment toJSiberia, and at last to six montlis' hard labour.
This punishment he had to undergo at Kiew, and immediately after
he retired to his estates in Croatia. The Austrian provinces on the
Turkish frontiers being, after the war, infested with numerous and
well-organised bands of robbers, Trenck voluntarily levied a force of
a thousand men among his own tenants, and succeeded in a very short
time in clearing the country of these dangerous enemies. A short
time afterwards disturbances breaking out in Hungary on the occasion
of Maria Theresa's succession to the throne, Trenck offered his own
and the services of his men, his regiment of Pandours, as he called
tliem, to the young empress. This offer was accepted, and Trenck
went to Vienna. The disturbances were however soon pacified by
Maria Theresa's heroic conduct at Presburg, and he was sent to the
army on the Rhine and in the Netherlands under the command of
Prince Charles. Here he again distinguished himself by his bravery
and military skill, but at the same time by his rapacity and brutal
ferocity. It was principally Trenck who covered Prince Charles's
celebrated retreat into IJohemia, and on his march through Bavaria
he took five fortified places in leas than three weeks. It would lead
too far here to relate the well-authenticated acts of plunder and
cruelty which he committed, but he and his Pandonrs were as much
dreaded over tho whole empire, as Tilly and his men in the Thirty
Years' War. In the following year he joined the army against
Frederic the Great, and after the battle of Sorau (September 14,
1745) he undertook to take the king by surprise at Collin, and to
carry him off prisoner. In this he failed with great loss of men ; but
he got a large booty, as he captured Frederic's tent and all that it
him, some of his own officers accusing him of having received bribes
from the enemy, besides unexampled cruelty and avarice. At his first
examination one of tho judges used some disrespectful expressions
towards Prince Charles; Trenck, with the fury and strength of a tiger,
jumped at him, nearly throttled him, and would have thrown him out
of a high window if the guard had not hastened to interfere. He was
confined at Vienna for upwards of a year, when Baroness Lestock, a
lady to whom he was betrothed, effected his escape by large bribes to
his jailers, who connived at his feigning to be dead. He was carried
in a coffin to be buried, but as soon as the funeral procession had got
outside the town gates, he jumped out of it, covered himself with a
cloak, mounted a horse which stood prepared, and made his way to
Bruges in the Netherlands, where he was however soon arrested again,
and was taken, heavily loaded with chains, to Graetz. Here in a fit of
despondency he took poison, and died October 4, 1747, leaving his
great wealth to his cousin Frederic, who however did not derive much
tsnefit from the bequest,
{Memoir es du Baron Franz de Trenck, dcrits par F. de Trenck, 1
vol. 8vo, Paris, 1787 ; Lcben und Tliaten der Trencke, von Watermann,
2 vols. 8vo, Leipzig, 1837; Mcmoires du Prince de Ligne, 2 vols. S'^o,
Vienne, 1816.)
TRENCK, BARON FREDERIC VON DER, born at Kbnigsberg,
February 16, 1726. His mother was a vonDershau, and both parents
belonged to the most ancient and wealthy houses in East Prussia.
His father had served with distinction as major-general in the Prussian
army. The young baron distinguished himself very early by extra-
ordinary precocity ; in his thirteenth year he was entered as a student
of law and belles lettres at the university of his native place, and
passed the usual examination with great distinction. One year later he
fought a duel with one of the most celebrated swordsmen at Koniga-
berg, whom he wounded and disarmed. In his sixteenth year Count
Lottum, one of his relations, and adjutant-general to Frederic (after-
watds the Great), took him to Berlin, where the king immediately
appointed him cadet, and soon afterwards, having himself upon one
occasion been surprised at the young man's talents, he promoted him
169
TFwENCK, BARON FREDERIC VON DER.
TRENTOWSKI, BRONISLA.W PERDYNAND.
160
to a cornetcy in his body-guard, at that time considered the most
splendid and gallant regiment in Europe, in which the rank of every
officer was three degreos higher than in other regiments. The king's
favour and his own amiable manners procured him many friends at
court, but at the same time excited envy and malice. The foundation
of his cruel fate is said to have been laid about two years afterwards at
a ball given at the royal castle at Stettin, in celebration of the marriage
of the Piincess Ulrike, the king's eldest Bister, with the king of
Sweden. The youngest sister, the Princess Amalie, is said to have
noticed liim, to have invited him to see her at her private apartments,
and to have cherished a violent passion for him ever afterwards. In
an unguarded moment he is said to have boasted of the favours shown
him by his royal misttess. This was reported to the king, who,
although he did not think proper to punish his indiscretion, took a
decided dislike to him, and watched every opportunity of visiting him
moat severely for trifling faults in military discipline. This story,
embellished with many romantic incidents, originates principally with
French writers, who in many instances contradict themselves as to
dates and other mutters. That an imprudent attachment between
Trenck and the princess existed cannot be doubted ; but that Frederic,
violent and passionate as he was in all his private concerns, should
have pretended blindness in so important a matter, and should even
have continued to bestow favours upon the man who had dishonoured
his sister's name, is difficult to credit.
During the war between Prussia and Austria he was placed on the
kings staff, and distinguished himself on several occasions, particularly
when his cousin, Franz Trenck, attempted to take the king prisoner
by surprise at Collin. A short time afterwards his cousin addressed
him a letter, returning him some of his horses which his Pandours had
taken upon one of their foraging expeditions. This circumstance he
mentioned in presence of a Colonel Jaachinsky, who owed him a
considerable sum of money, and who at Beilin was known to be his
secret enemy. This man artfully persuaded him to a correspondence
with his cousin, he himself undertaking to forward the letters by
means of his mistress, the wife of the Saxon resident, Madame de
Brossat. Several letters passed in this way open through Jaschinsky's
hands, until he got possession of one in which some highly imprudent
expressions were found, which he immediately caused to be laid
before the king. The result was, that Trenck was cashiered and sent
prisoner to the fortification of Glatz, not by a formal sentence, but by
an order from the king, who expressed his intention at the same time
to keep him there for one year ; evidence enough it would seem, that
he only meant to punish Lis correspondence with the enemy, and no
other or greater crime. At first he was treated according to his
rank, and with all possible indulgence; but when it was discovered
that he had several times, by bribts, attempted and nearly effected his
escape, he was placed in close confinement. Ou the 24th of December
1746, he nevertheless succeeded in making his escape, by the assistance
of and together with Major Schell. With great fatigue and danger he
reached his mother's residence in Brandenburg, whence he proceeded
to Vienna, amply furnished with money. A strict investigation was
ordered by the king, for the purpose of finding out how he had
effected his escape ; the result of which was the discovery that large
sums had been remitted to him by the Princess Amalie. It is highly
probable that this was the first time that Frederic knew of his sister's
attachment; and from this period must be dated his intense and obdu-
rate hatred of Trenck. In the mean time Trenck had got into fresh
troubles at Vienna, which ho himself principally attributes to the intri-
gues of his cousin Franz, notwithstanding he was in prison at the time
ou a criminal charge. He left Vienna in disgust, and went to Russia,
where, through the recommendation of the English ambassador (to
whom Frederic himself had introduced him at Berlin, under the
flattering title of ' Matador de ma jeunesse'), he was well received, and
appointed captain of a troop of hussars. Here he might have lived
peaceably and content, being in high favour with the empress, and
having acquired considerable wealth through a legacy of a Russian
princess; but the Prussian ambassador. Count Goltz, left nothing
undone to injure him, pi'etending that he acted thus in accordance
with instructions from the king his master. His cousin at Vienna,
to leave Russia; and after having visited Sweden, Denmark, and Hol-
land, he returned to Vienna to take possession of his inheritance. Fresh
difficulties awaited him there. His cousin's estates were under seques-
tration, and after expensive and vexatious suits, he agreed to a com-
promise, by which ho received 75,000 florins, and the appointment of
a captaincy in a regiment of hussars. In 1748 he went to Prussia to
visit his family; and at Dantzig, when on the point of embarking for
Sweden, owing to some hints of impending danger which he had
received, he was arrested by a party of hussars, and taken prisoner to
Berlin. He was at first ti-eated well, but his intemperate language,
and even threats against the king, hurried on his fate. He was taken
to Magdeburg, and confined in a cell under-ground, and almost with-
out light. His sufferings, and his bold, desperate, and almost success-
ful attempts to escape, may be read in his own Memoirs. After two
soldiers had suffered death for conniving at his attempts to regain his
liberty, and several other plots had been discovered, a prison was at
last built on purpose for him, in which he was chained to the walls
ivith fetters of sixty-seven pounds weight. Here he remained above four
years more, till at last his relations succeeded in softening Frederic's
obduracy ; and on the 24th December 1763, he was released upon con-
dition of leaving the kingdom. He went first to Vienna, where he
was again arrested on account of his violent language against Frederic
The emperor however having convinced himself by a personal inter-
view that his words were tho mere outbreak of unmeaning rage after
his dreadful sufferings, set him free, paid him the arrears of his salary
as a captaiu, and advised him to retire in order to recover his health
and his spirits. Ho settled at Aix-la-Chapelle, married a daughter of
the burgomaster De Broe, and commeuced business as a wiue-raer-
chant. He went several times to England upon commercial affairs,
but notwithstanding all his exertions his affairs did not prosper, and
he became a bankrupt. After this new misfortune ho wrote articles
of rather a democratic tendency for several periodical publicatious;
and in 1787, after the death of Frederic the Great, he published his
Memoirs, for the copyright of which he received a very large sum. From
that time he became for a time a distinguished person in the world.
His book was translated into almost all European languages; the
ladies at Paris, Berlin, and Vienna wore rings, necklaces, bonnets, and
gowns h, la Treuck, and not less than seven different theatrical pieces
in which he was the hero were brought out ou the French stage. The
3'ear following he once more visited Berlin; but although he was
kindly received by the king, it seems that he was disappointed iu his
expectations, and he returned to Aix-la Chapelle, where he commenced
the publication of a weekly paper, under the title of ' L'Ami dcs
Horames,' in which he proclaimed himself a champion of the new
French doctrines. Meeting with little encouragement, he went to
Paris iu 1792, joined a Jacobin club, and was afterwards a zealous adhe-
rent to the Mountain party, which nevertheless betrayed, accused
him, and brought him to the guillotine on the 25th July 1794. Yet
on the scaffold, and in his sixty-eighth ye;ir, he gave proof of his
ungovernable passions. Ho harangued the surrounding multitude,
and when his head was on the block he once more attempted to give
utterance to his vehemence, and the executioner had to hold him by
his silver locks to meet the fatal stroke.
(Friedrich Trenk's Merkwurdige Lebcnsgeschlchle von ihm sdbst
besckrieben, 2 vols. Svo, Berlin, 1787 ; Meditations du, Baron de Trenck
dans sa Prison d Magdebourg, avec un precis histonqne de sea mal-
heiirs, 1 vol. 8vo, Paris, 1788; DenJcwiirdigheiten von Freyherrn von
Dokm, Berlin, 1812 ; D. Thi^bault, Frederic le Grand, ou Souvenirs de
vingt ans de scj'our d, Berlin, 2 vols, Svo, Paris, 1801 ; Leben und
Thaetcn der Trcnke von Watermann, 2 vols, 8vo, Leipzig, 1837.)
TRENTO, ANTONIO DA, supposed to be the same person as
Antonio Fantuzzi. He was born at Ti-ente about tho commencement
of the 10th century; and was, according to Vasari, the pupil of Par-
migiano at Parma, Parmigiano employed Antonio to engrave his
works in wood, and he was one of the first and most eminent of the
Italian wood-engravers ; he appears to have imitated the cuts of Hugo
da Carpi, Antonio Fantuzzi lived with Parmigiano, but apparently
unwillingly, for about 1530 he decamped from his master, taking with
him many of his drawings, plates, and wood-cuts, and went, it is
supposed, to France, where he appeared again under the name of
Antonio da Trento. He attached himself iu France to Primaticcio,
who employed him to engrave or etch some of his works in copper:
he executed also etchings after some other masters while in France.
Batsch describes thirty-seven etchings by him, but he is more cele-
brated for his wood-cuts which he engraved in chiaroscuro. Tho time
of his death is not known, but it happened probably about 1550 : the
dates on his prints reach to 1545. Some of the wood-cuts of Antonio
are printed with three, others with two blocks ; they are chiefly after
Parmigiano, as The Twelve Apostles ; St. John in the Wilderness ; the
Martyrdom of St. Peter and St, Paul; St. Cecilia; the Tiburtine Sibyl;
and others. Among his etchings is one of Regulus in the Cask, after
Giulio Romano,
(Yasari, Vite cZe' Pittori, &e. ; Bartsch, PeintreQraveur ; Nagler,
Allgemeines Kiinstler Lexicon.)
* TRENTO WSKI,BRONISL AW FERDYNAND, a Polish philoso-
phical writer of high reputation, was born, in 1803, near Warsaw,
received his education at the Piarist College of Lukow and at the
University of Warsaw, and was appointed in 1829 teacher of the
Latin language, of history, and of Polish literature, at the college, or
grammar-school, of Szczuczyn. Having taken part in the insurrection
of 1830, he was in consequence obliged to leave Poland, aud fixed
himself after one or two changes of residence at Freiburg in the
Breisgau, where he, in 1836, published an academical dissertation,
'De vita hominis roterna' (On human immortality), and afterwards
wrote two works in German, 'Grundlage der imiversellen Philosophie'
Carlsruhe, 1S37 (Basis of universal Philosophy), and 'Vorstudieu zur
W^issenschaft der Natur,' 2 vols, Leipzig, 1840 (Preliminary Studies to
the Science of Nature). In the preface to the 'Grundlage' he men-
tions that " five years before he understood hardly any German, nay,
he could not even dream that ever in his life he should be compelled
to speak and to write in German." " But thou, my beloved, my
unspeakably beloved country," he continues, "thou tho Paradise
from which I am banished, be not indignant with thy son that he
writes not in thy language. Unhappy, oppressed, and weeping
orphan, I could be of more use to thee than to this foreign land, so"
rich in genius — but who is master of his destiny ?" Some Poles who
I
161
TEESCHOW, NIELS.
TREVOR, SIR JOHN.
163
were aroused by this appeal, provided Trentowski with means to
follow out his wishes, and he wrote a series of works ia Polish, which
were jjublished iu Posen, and produced a considerable sensation. The
first, 'Chowiinna czyli System Pedagogiki,' 2 vols., 1842 (Education on
a System of Pedagogics), reached a second edition iu 1846, but was to
have been completed by a tbird volume which does not seem to have
yet appeared. ' My.slini czyli Logika,' 2 vols., 1844 (Logic), aud
'Stosunek filozofii do Cybernitiki,' 1843 (The Relation of Philosophy
to the Science of Government), are two of the most important of the
remainder. ' Demonomania,' Posen, 1844, is a collection of narratives
of supernatural appearances, with an attempt at explanation connected
with a theory of the supernatural, Mftny essays by Trentow-ki
appeared in the Polish periodicals 'Rok' and ' Oredownik naukowy,'
published at Poseu. In 1848 Trentowski took advantage of the state
of affairs in general to return to Cracow, where he gave public lectures,
but he afterwards returned to Freiburg, where he lives in retirement
married to a German lady. As a philosopher, he seeks, while still a
disciple of Kant, to unite empiricism with speculation, and to introduce
a sort of Polish practicality into a philosophy fundamentally German ;
and as an author, either iu German or Polish, he is brilliant and
attractive in style, and shows a desire to accompany every step of
speculation with illustrations of an intelligible character.
TRESCHOW, NIELS, a Danish philosophical and theological
writer, was the son of a shopkeeper or tradesman at Drammen in
Norway, where he was born September 5th, 1751. From his parents,
who were serious and I'eligious persons, he received a careful education,
which, seconded by his natural abilities and love of reading, sufficiently
prepared him for the university iu his fifteenth year, when he was sent
to Copenhagen to study theology. Though he did not neglect divinity,
he showed a preference for philosophy, history, mathematics, and the
physical sciences, iu which studies he found companions in Edward
Stox-m [Storm] and Nordal Brun, who were also natives of Norway.
After spending five years at Copenhagen, he became corrector or sub-
master of the classical school at Drontheim ; and it was there that he
first took up his pen as an author. In 1780 he was appointed to suc-
ceed the celebrated Jacob Baden as rector of the academy of Helsingor,
at which time he studied Kant's writings, and explained his philosophy
in a series of able papers in the * Minerva.' Not many years afterw"ards
(1789) he obtained the appointment to the head-mastership of the
cathedral school at Christiania, which, besides being valuable for its
emoluments, brought him into intercourse with mauy individuals dis-
tinguished not only by their wealth and station, but by their patriotism
aud philanthropy, aud their zeal in promoting the spread of intelli-
gence. Encouraged by them, he turned his attention to the improve-
ment of the system of education in Denmark, but, owing to the oppo-
sition they met with in other quarters, his plans were only very
partially carried into effect. In 1796 his dissertation ' De Anthropo-
morphismo ' obtained for him the degree of doctor of theology from
the university of Copenhagen, at which he was afterwards (1303)
appointed professor in ordiuary of philosophy, an ofEce filled by him
with honour to himself and satisfaction and advantage to the students.
In 1813 he quitted Copenhagen for Christiania, in order to accept the
chair of philosophy in the new Frederick's University, an institution
which he had been mainly instrumental in founding. On the union
of Norway with Sweden, he was made by the new king superintendent
of public instruction and church affairs, which office he held for twelve
years, when he retired to a small estate in the neighbourhood of
Christiania, and resided there till his death, September 22, 1833.
Among his chief works are — ' Morality in Connection with the State,'
&c. ; ' Principles of Legislation ; ' ' Spirit of Christianity ; ' ' Transla-
tion of the Gospel of St, John ; ' and the ' Philosophical Testament,
or God, Nature, and Revelation ; ' all of which were the productions
of his studious retirement after relinquishing public duties in 1826.
TREVI'GL or TREVI'SI, GIRO'LAMO DA, was born at Trevigi in
1508. He was apparently the son of the painter Piermaria Pennacchi,
who was doubtless his instructor in painting. Girolamo however, not
wholly satisfied with the accuracy of the Venetian painters, became
an imitator of the style of Raffaelle, and combined to a considerable
extent the qualities of both schools. He lived some time in Bologna,
where he painted some excellent works, especially from the stoiy of
Sant' Antonio of Padua, in oil, in the cathedral. He left Bologna in
consequence of the superior fame of Perino del Vaga, then at Bologna.
After painting several works in fresco at Venice, Trent, and some
other places, he came to England and entered the service of Henry VIII.,
who employed him as architect and engineer, with a fixed salary of
nearly lOQl. per annum. He was engaged in the capacity of engineer
in the year 1544 before Boulogne, and was there killed by a cannon-
shot, iu his thirty-sixth year.
There are some excellent portraits by Girolamo; they are well
coloured and in an elaborate but broad manner, much in the style of
the portraits by Raffaelle. There is a fine specimen in the Colonna
palace at Rome ; it is a half-length of a man in the picturesque cos-
tume of the period, holding a ring or signet in his hand. There are,
or were, other pictures by Girolamo in this palace. A picture of the
Madonna with various saints, which, according to Vasari, was Giro-
lamo's masterpiece, is now in the collection of Lord Northwick, at
Thirlstane House, Cheltenham ; it was formerly ia the church of San
Domenico, at Bologna.
BIOG.DIV. VOL. VI.
There was an earlier painter called Girolamo da Trevigi, by whom
there are still works bearing dates from 1470 to 1492 : his Burname,
according to Federici, was Aviano.
TREVISA'NI, A'NGELO, of Venice, was an excellent portrait-
painter, and painted also some good historical pieces : he excelled in
chiar'oscuro. There is a fine altar-piece by him in the church Delia
Carith, at Venice. Neither the date of his birth nor death is known ;
accounts differ, but he was living in 1753. There are portraits of both
the Trevisani in the painters' portrait gallery at Florence.
TREVISA'NI, FRANCESCO, CAVALIERE, an eminent Italian
painter, was born at Capo d'Istria near Trieste, in 1656. He is called
by the Venetians, Roman Trevisani, to distinguish him from Angelo
Trevisani of Venice. Francesco acquired the first principles of design
from his father Antonio Trevisani, an architect, and learnt painting of
a Fleming, whose name is not mentioned, who was remarkable for his
pictures of spectres, incantations, and such subjects ; and young Tre-
visani executed a very good picture in the same style in his eleventh
year. He afterwards became the scholar of Antonio Zanchi at Venice,
and painted in his style for some time : he then studied the works of
the great Venetian masters, and distinguished himself by several fine
pictures in the Venetian manner, which he painted at Venice whilst
still young. Being a man of striking personal appearance, and very
accomplished in several polite arts, he went much into society, and he
won the affections of a noble young Venetian lady, with whom he
eloped and married, and he went with her to Rome, to avoid the con-
sequences of the resentment of her family. At Rome, Trevisani was
fortunate enough to find a valuable patron in the Cardinal Flavio
Chigi, nephew of Pope Alexander VII., for whom he executed several
works, and who procured him the title of Cavaliere from the pope.
He was much employed also by the Duke of Modena, then Spanish
ambassador at the court of Rome, for whom he made several copies
after celebrated pictures by Correggio, Parmegiano, and Paul Veronese.
After the death of Cardinal Chigi he was much patronised by Cardinal
Ottobuoni, for whom he painted an excellent picture of the Slaughter
of the Innocents. Trevisani's works are numerous in Rome; he
painted also for many other cities, and for foreign countries ; he exe-
cuted some pictures for Peter the Great of Russia. He died in 1746,
aged ninety.
After his arrival in Rome he forsook the Venetian manner of
painting, and adopted that which prevailed in Rome at that period,
which consisted chiefly in the imitation of Guido, Domenichino, and
others of the Carracci school. But Trevisani painted in many styles,
and iu almost every line — history in large and small figures, portraits,
animals, sea pieces, landscapes, architecture, and flowers; he could
imitate well a picture by any master. His best pictures are a good
deal in the style of Guido ; his composition is grand, and his chiar'-
oscuro forcible, his execution free and bold, and his drawing generally
correct and graceful; but bin chief excellence consisted in a pui'ity
and brilliancy of colouring. His best pictures are, a Crucifixion, in
the church of San Silvestro in Capite ; a San Francesco, in the church
of San Francesco delle Sagre Stimate ; Saint Joseph dying, in the
church of the CoUegio Reale ; and a Prophet, in the church of Sau
Giovanni Laterano ; and the cupola of the cathedral of Urbino,
painted for Clement XI. The Albicini family at Forli possessed in
the time of Lanzi various specimens of his different styles, amongst
them a Crucifixion, in which the figures were very small but elaborately
painted, which Trevisani is said to have considered his best picture,
and to have offered a lai-ge sum for its re-purchase.
TREVOR, SIR JOHN, Knight, a secretary of state in the reign of
Charles II., was born in 1626, and was the eldest son of Sir John
Trevor, Knight, of Trevallin in Denbighshire, and descended from an
ancient Welsh family. Anthony Wood, in recording his appointment
as secretary of state, says of him and his father that they were both
"halters in the rebellion, and adherers to the usurper." ('Athena)
Oxonienses,' | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4157174825668335, "perplexity": 13897.924379453387}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610703514046.20/warc/CC-MAIN-20210117235743-20210118025743-00222.warc.gz"} |
http://math.stackexchange.com/users/21783/raymond-manzoni?tab=reputation | # Raymond Manzoni
less info
reputation
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bio website location age member for 2 years, 2 months seen 3 hours ago profile views 4,899
Contact: raymman (at) free (dot) fr
# 22,847 Reputation
20 Mar 6
+10 21:39 upvote Where can i find resourses to study this algebraic number theory? +10 05:22 upvote Conjecture $_2F_1\left(\frac14,\frac34;\,\frac23;\,\frac13\right)=\frac1{\sqrt{\sqrt{\frac4{\sqrt{2-\sqrt[3]4}}+\sqrt[3]{4}+4}-\sqrt{2-\sqrt[3]4}-2}}$
10 Mar 3
+10 21:06 upvote Demystify integration of $\int \frac{1}{x} dx$ 18:08 upvote Examples of apparent patterns that eventually fail
15 Mar 2
+15 13:35 accept Complex integration help
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15 Jan 11 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.40726009011268616, "perplexity": 11195.233728112793}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-10/segments/1394011112269/warc/CC-MAIN-20140305091832-00066-ip-10-183-142-35.ec2.internal.warc.gz"} |
http://ezyexamsolution.com/jee-mains-temperature-of-heat/ | # JEE Mains Temperature of Heat
mains mathematics Basic Advanced Physics, IIT JEE Mains Physics, Motion Elasticity, Current Elasticity, Fluids, Thermal Properties of Matter, The Ideal Gas Law of Kinetic Theory of Gases, Laws of Thermodynamics, Calorimetry Heat
### Subtopic of
(i) Heat, (ii) Temperature, (iii) Scales of temperature, (iv) Thermometry, (v) Thermometers, (vi) Thermal expansion, (vii) Variation of density with temperature, (viii) Expansion of liquid, (ix) Effect of temperature on upthrust, (x) Anomalous expansion of water, (xi) Expansion of gases, (xii) Application of thermal expansion, (xiii) Thermal capacity and water equivalent, (xiv) Specific heats of solids, water, (xvi) Latent heats, (xvii) Principle of caloriemetry, (xviii) Heating curve
# Heat
The energy associated with configuration and random motion of the atoms and molecules within a body is called internal energy and the part of this internal energy which is transferred from one body to the other due to temperature difference is called heats.
As heat is a form of energy it can be transformed into others and vice-versa.
e.g. Thermocouple converts heat energy into electrical energy, resistor converts electrical energy into heat energy. Friction converts mechanical energy into heat energy. Heat engine converts heat energy into mechanical energy.
Here it is important that whole of mechanical energy i.e. work can be converted into heats but the whole of heats can never be converted into work.
Generally, the temperature of a body rises when the heat’s supplied to it. However, the following two situations are also found to exist.
(i) When heat is supplied to a body either at its melting point or boiling point, the temperature of the body does not change. In this situation, heat supplied to the body is used up in changing its state.
(ii) When the liquid in a thermos flask is vigorously shaken or gas in a cylinder is suddenly compressed, the temperature of liquid or gas gets raised even without supplying heat. In this situation, work done on the system becomes a source of heats energy.
## 01. Temperature and Heat JEE Mains pattern MCQ Paper (Download here PDF.)
### 02. Temperature and Heat JEE Mains pattern MCQ Paper (Download here PDF.)
Joint Entrance Exam Aircraft Maintenance Engineering
#### Thermometry
An instrument used to measure the temperature of a body is called a thermometer.
The linear variation in some physical property of a substance with the change of temperature is the basic principle of thermometry and these properties are defined as a thermometric property (x) of the substance.
x may be (i) Length of liquid in the capillary
(ii) The pressure of gas at constant volume.
(iii) The volume of gas at constant pressure.
(iv) The resistance of a given platinum wire.
In old thermometry, two arbitrarily fixed points ice and steam point (freezing point and the boiling point at 1 atm) are taken to define the temperature scale. In Celsius scale freezing point of water is assumed to be 0°C while boiling point 100°C and the temperature interval between these is divided into 100 equation.
#### Thermal Expansion
When matter is heated without any change in state, it usually expands. According to atomic theory of matter, asymmetry in potential energy curve is responsible for thermal expansion. As with rising in temperature the amplitude of vibration and hence the energy of atoms increases, hence the average distance between the atoms increases. So the matter as a whole expands.
(1) Thermal expansion is minimum in case of solids but maximum in case of gases because the intermolecular force is maximum in solids but minimum in gases.
(2) Solids can expand in one dimension (linear expansion), two dimensions (superficial expansion) and three dimensions (volume expansion) while liquids and gases usually suffer the change in volume only.
### Latent Heat
(1) When a substance changes from one state to another state (say from solid to liquid or liquid to gas or from liquid to solid or gas to liquid) then energy is either absorbed or liberated. This heat energy is called latent heat.
(2) No change in temperature is involved when the substance changes its state. That is, phase transformation is an isothermal change. Ice at 0°C melts into water at 0°C. Water at 100°C boils to form steam at 100°C.
Freezing mixture : If salt is added to ice, then the temperature of mixture drops down to less than 0°C. This is so because, some ice melts down to cool the salt to 0°C. As a result, salt gets dissolved in the water formed and saturated solution of salt is obtained, but the ice point (freezing point) of the solution formed is always less than that of pure water. So, ice cannot be in the solid state with the salt solution at 0°C. The ice which is in contact with the solution starts melting and it absorbs the required latent heat from the mixture, so the temperature of the mixture falls down.
#### The principle of Calorimetry:
When two bodies (one being solid and other liquid or both being liquid) at different temperatures are mixed, heat will be transferred from a body at higher temperature to a body at lower temperature till both acquire the same temperature. The body at higher temperature releases heat while the body at lower temperature absorbs it, so that
i.e. the principle of calorimetry represents the law of conservation of heat energy.
Conduction: Transfer of energy due to vibration and collision of medium particles without dislocation from their equilibrium position.
Updated: July 20, 2018 — 2:08 pm
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http://www.physicsforums.com/showthread.php?t=487868 | # Probability problem - birthdays
by Char. Limit
Tags: birthdays, probability
PF Gold
P: 1,951
1. The problem statement, all variables and given/known data
44. What is the probability that at least two people in your class (assume a class of 30 students) have the same birthday?
2. Relevant equations
I'm not sure, to be honest.
3. The attempt at a solution
I was helping out my roommate with his probability homework, and this question came up. I'm not sure how to answer it. How is this done? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.811499297618866, "perplexity": 532.1267789634916}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1409535922871.14/warc/CC-MAIN-20140901014522-00121-ip-10-180-136-8.ec2.internal.warc.gz"} |
https://software.broadinstitute.org/gatk/guide/article?id=3225 | ## I am unable to use VQSR (recalibration) to filter variantsCommon Problems | Created 2013-09-11 | Last updated 2016-07-29
### The problem:
Our preferred method for filtering variants after the calling step is to use VQSR, a.k.a. recalibration. However, it requires well-curated training/truth resources, which are typically not available for organisms other than humans, and it also requires a large amount of variant sites to operate properly, so it is not suitable for some small-scale experiments such as targeted gene panels or exome studies with fewer than 30 exomes. For the latter, it is sometimes possible to pad your cohort with exomes from another study (especially for humans -- use 1000 Genomes or ExAC!) but again for non-human organisms it is often not possible to do this.
### The solution: hard-filtering
So, if this is your case and you are sure that you cannot use VQSR, then you will need to use the VariantFiltration tool to hard-filter your variants. To do this, you will need to compose filter expressions using JEXL as explained here based on the generic filter recommendations detailed below. There is a tutorial that shows how to achieve this step by step. Be sure to also read the documentation explaining how to understand and improve upon the generic hard filtering recommendations.
### But first, some caveats
Let's be painfully clear about this: there is no magic formula that will give you perfect results. Filtering variants manually, using thresholds on annotation values, is subject to all sorts of caveats. The appropriateness of both the annotations and the threshold values is very highly dependent on the specific callset, how it was called, what the data was like, what organism it belongs to, etc.
HOWEVER, because we want to help and people always say that something is better than nothing (not necessarily true, but let's go with that for now), we have formulated some generic recommendations that should at least provide a starting point for people to experiment with their data.
In case you didn't catch that bit in bold there, we're saying that you absolutely SHOULD NOT expect to run these commands and be done with your analysis. You absolutely SHOULD expect to have to evaluate your results critically and TRY AGAIN with some parameter adjustments until you find the settings that are right for your data.
In addition, please note that these recommendations are mainly designed for dealing with very small data sets (in terms of both number of samples or size of targeted regions). If you are not using VQSR because you do not have training/truth resources available for your organism, then you should expect to have to do even more tweaking on the filtering parameters.
### Filtering recommendations
Here are some recommended arguments to use with VariantFiltration when ALL other options are unavailable to you. Be sure to read the documentation explaining how to understand and improve upon these recommendations.
Note that these JEXL expressions will tag as filtered any sites where the annotation value matches the expression. So if you use the expression QD < 2.0, any site with a QD lower than 2 will be tagged as failing that filter.
#### For SNPs:
• QD < 2.0
• MQ < 40.0
• FS > 60.0
• SOR > 3.0
• MQRankSum < -12.5
• ReadPosRankSum < -8.0
If your callset was generated with UnifiedGenotyper for legacy reasons, you can add HaplotypeScore > 13.0.
#### For indels:
• QD < 2.0
• ReadPosRankSum < -20.0
• InbreedingCoeff < -0.8
• FS > 200.0
• SOR > 10.0
### And now some more IMPORTANT caveats (don't skip this!)
• The InbreedingCoeff statistic is a population-level calculation that is only available with 10 or more samples. If you have fewer samples you will need to omit that particular filter statement.
• For shallow-coverage (<10x), it is virtually impossible to use manual filtering to reliably separate true positives from false positives. You really, really, really should use the protocol involving variant quality score recalibration. If you can't do that, maybe you need to take a long hard look at your experimental design. In any case you're probably in for a world of pain.
• The maximum DP (depth) filter only applies to whole genome data, where the probability of a site having exactly N reads given an average coverage of M is a well-behaved function. First principles suggest this should be a binomial sampling but in practice it is more a Gaussian distribution. Regardless, the DP threshold should be set a 5 or 6 sigma from the mean coverage across all samples, so that the DP > X threshold eliminates sites with excessive coverage caused by alignment artifacts. Note that for exomes, a straight DP filter shouldn't be used because the relationship between misalignments and depth isn't clear for capture data.
### Finally, a note of hope
Some bits of this article may seem harsh, or depressing. Sorry. We believe in giving you the cold hard truth.
HOWEVER, we do understand that this is one of the major points of pain that GATK users encounter -- along with understanding how VQSR works, so really, whichever option you go with, you're going to suffer. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3944457173347473, "perplexity": 1442.9129652819706}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-40/segments/1474738661213.28/warc/CC-MAIN-20160924173741-00265-ip-10-143-35-109.ec2.internal.warc.gz"} |
http://codeforces.com/problemset/problem/918/B | B. Radio Station
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
As the guys fried the radio station facilities, the school principal gave them tasks as a punishment. Dustin's task was to add comments to nginx configuration for school's website. The school has n servers. Each server has a name and an ip (names aren't necessarily unique, but ips are). Dustin knows the ip and name of each server. For simplicity, we'll assume that an nginx command is of form "command ip;" where command is a string consisting of English lowercase letter only, and ip is the ip of one of school servers.
Each ip is of form "a.b.c.d" where a, b, c and d are non-negative integers less than or equal to 255 (with no leading zeros). The nginx configuration file Dustin has to add comments to has m commands. Nobody ever memorizes the ips of servers, so to understand the configuration better, Dustin has to comment the name of server that the ip belongs to at the end of each line (after each command). More formally, if a line is "command ip;" Dustin has to replace it with "command ip; #name" where name is the name of the server with ip equal to ip.
Dustin doesn't know anything about nginx, so he panicked again and his friends asked you to do his task for him.
Input
The first line of input contains two integers n and m (1 ≤ n, m ≤ 1000).
The next n lines contain the names and ips of the servers. Each line contains a string name, name of the server and a string ip, ip of the server, separated by space (1 ≤ |name| ≤ 10, name only consists of English lowercase letters). It is guaranteed that all ip are distinct.
The next m lines contain the commands in the configuration file. Each line is of form "command ip;" (1 ≤ |command| ≤ 10, command only consists of English lowercase letters). It is guaranteed that ip belongs to one of the n school servers.
Output
Print m lines, the commands in the configuration file after Dustin did his task.
Examples
Input
2 2main 192.168.0.2replica 192.168.0.1block 192.168.0.1;proxy 192.168.0.2;
Output
block 192.168.0.1; #replicaproxy 192.168.0.2; #main
Input
3 5google 8.8.8.8codeforces 212.193.33.27server 138.197.64.57redirect 138.197.64.57;block 8.8.8.8;cf 212.193.33.27;unblock 8.8.8.8;check 138.197.64.57;
Output
redirect 138.197.64.57; #serverblock 8.8.8.8; #googlecf 212.193.33.27; #codeforcesunblock 8.8.8.8; #googlecheck 138.197.64.57; #server | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.23225949704647064, "perplexity": 4101.981723152609}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540487789.39/warc/CC-MAIN-20191206095914-20191206123914-00285.warc.gz"} |
http://www.maa.org/press/books/exploring-advanced-euclidean-geometry-with-geogebra | Exploring Advanced Euclidean Geometry with GeoGebra
By Gerard Venema
Catalog Code: EAEG
Print ISBN: 978-0-88385-784-7
Electronic ISBN: 978-1-61444-111-3
129 pp., Hardbound, 2013
List Price: $52.00 Member Price:$39.00
Series: Classroom Resource Materials
This book provides an inquiry-based introduction to advanced Euclidean geometry. It utilizes dynamic geometry software, specifically GeoGebra, to explore the statements and proofs of many of the most interesting theorems in the subject. Topics covered include triangle centers, inscribed, circumscribed, and escribed circles, medial and orthic triangles, the nine-point circle, duality, and the theorems of Ceva and Menelaus, as well as numerous applications of those theorems. The final chapter explores constructions in the Poincaré disk model for hyperbolic geometry.
The book can be used either as a computer laboratory manual to supplement an undergraduate course in geometry or as a stand-alone introduction to advanced topics in Euclidean geometry. The text consists almost entirely of exercises (with hints) that guide students as they discover the geometric relationships for themselves. First the ideas are explored at the computer and then those ideas are assembled into a proof of the result under investigation. The goals are for the reader to experience the joy of discovering geometric relationships, to develop a deeper understanding of geometry, and to encourage an appreciation for the beauty of Euclidean geometry.
Quick Review of Elementary Euclidean Geometry
1. The Elements of GeoGebra
2. The Classical Triangle Centers
4. Circumscribed, Inscribed, and Escribed Circles
5. The Medial and Orthic
7. The Nine-Point Circle
8. Ceva's Theorem
9. The Theorem of Menelaus
10. Circles and Lines
11. Applications of the Theorem of Menelaus
12. Additional Topics in Triangle Geometry
12.1. Napoleon's theorem and the Napoleon point
13. Inversions in Circles
14. The Poincare Disk
Textbook Solution Manual
Gerard Venema earned an A.B. in mathematics from Calvin College and a Ph.D. from the University of Utah. After completing his education he spent two years in a postdoctoral position at the University of Texas at Austin and another two years as a Member of the Institute for Advanced Study in Princeton, NJ. He then returned to his alma mater, Calvin College, and has been a faculty member there ever since. While on the Calvin College faculty he has also held visiting faculty positions at the University of Tennessee, the University of Michigan, and Michigan State University. He spent two years as a Program Director in the Division of Mathematical Sciences at the National Science Foundation.
Venema is a member of the American Mathematical Society and the Mathematical Association of America. He served for ten years as an Associate Editor of The American Mathematical Monthly and currently sits on the editorial board of MAA FOCUS. Venema has served the Michigan Section of the MAA as chair and is the 2013 recipient of the section’s distinguished service award. He currently holds the position of MAA Associate Secretary and is a member of the Association’s Board of Governors.
Venema is the author of two other books. One is an undergraduate textbook, Foundations of Geometry, published by Pearson Education, Inc., which is now in its second edition. The other is a research monograph coauthored by Robert J. Daverman. It is titled Embeddings in Manifolds and was published by the American Mathematical Society as volume 106 in its Graduate Studies in Mathematics series. In addition to these books, Venema is author of over 30 research articles in geometric topology.
MAA Review
Discovery learning (or inquiry-based learning, or Moore method, or many other related variants) de-emphasizes lecture and reading in favor of allowing students to develop on their own as much of the material as possible. Euclidean geometry is an excellent playground for this because you can start with a few comprehensible common notions and postulates and run with them.
One step that is sometimes missing from the discovery learning process is the computer. Really understanding a result requires not just proof but probing deeply into the assumptions and finding examples that illustrate what is happening. In geometry in particular, there is software available to help students find the examples that lead to understanding, proofs, and new conjectures. Gerard A. Venema’s Exploring Advanced Euclidean Geometry with GeoGebra is a discovery learning text that embraces this approach. Continued... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.25532323122024536, "perplexity": 1254.846834034826}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501171620.77/warc/CC-MAIN-20170219104611-00646-ip-10-171-10-108.ec2.internal.warc.gz"} |
http://tailieu.vn/doc/kalman-filtering-and-neural-networks-chapter-1-kalman-filters-211170.html | # Kalman Filtering and Neural Networks - Chapter 1: KALMAN FILTERS
Chia sẻ: Dph Dph | Ngày: | Loại File: PDF | Số trang:21
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## Kalman Filtering and Neural Networks - Chapter 1: KALMAN FILTERS
Mô tả tài liệu
The celebrated Kalman filter, rooted in the state-space formulation of linear dynamical systems, provides a recursive solution to the linear optimal filtering problem. It applies to stationary as well as nonstationary environments. The solution is recursive in that each updated estimate of the state is computed from the previous estimate and the new input data, so only the previous estimate requires storage.
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Lưu | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9489732384681702, "perplexity": 3274.814974427363}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891813602.12/warc/CC-MAIN-20180221083833-20180221103833-00166.warc.gz"} |
http://www.emathzone.com/tutorials/geometry/area-of-irregular-figures/ | # Area of Irregular Figures
• ### Introduction to Irregular Figures
A figure which is not uniform and regular in shape is where an irregular figure. There are several practical situations where it is necessary to estimate the area of the irregular figures. For example, the areas of plots of land, areas of indicator diagrams of steam engines and area of ships by naval architects, etc. […]
• ### Trapezoidal Rule
To find the area of the as shown in the figure, the base is divided into number of equal intervals of width . The ordinates are accurately measured. The approximation used in this rule is to assume that each strip is equal to the area of a trapezium. Therefore Area of a Trapezium (Sum of […]
• ### Simpsons Rule
The most important rule, in practice, is the Simpson’s Rule, because of its simplicity and accuracy. When more accuracy is required, this rule should be used. To find the area as shown in figure, the base must be divided into an even number of strips of equal width , producing an odd number of ordinates. […] | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9257878065109253, "perplexity": 442.5505435407912}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501173866.98/warc/CC-MAIN-20170219104613-00048-ip-10-171-10-108.ec2.internal.warc.gz"} |
https://www.gradesaver.com/textbooks/math/algebra/college-algebra-6th-edition/chapter-p-prerequisites-fundamental-concepts-of-algebra-exercise-set-p-2-page-33/3 | College Algebra (6th Edition)
$64$
An exponential expression has a base (the bottom) and an exponent (the top). The exponent indicates how many factors of the base are multiplied together. When the exponent is even, the solution will be positive, even if you start with a negative base. $$(-2)^{6}$$ $$=(-2)\times(-2)\times(-2)\times(-2)\times(-2)\times(-2)$$ $$=4\times(-2)\times(-2)\times(-2)\times(-2)$$ $$=(-8)\times(-2)\times(-2)\times(-2)$$ $$=16\times(-2)\times(-2)$$ $$=(-32)\times(-2)$$ $$=64$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9076613187789917, "perplexity": 202.33560256779776}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267155942.15/warc/CC-MAIN-20180919063526-20180919083526-00076.warc.gz"} |
http://mathhelpforum.com/trigonometry/126608-prove-following-trigonometrical-identity.html | # Math Help - Prove the following trigonometrical identity-
1. ## Prove the following trigonometrical identity-
(1- tan x + sec x)/(1+tan x + sec x) = cos x/(1+sin x)
2. ## Hii
quick question, are you allowed to manipulate the right side of the equation? Some teachers don´t appreciate that..
What have you tried so far?
Have you tried writing $tan(x)= \frac{sin(x)}{cos(x)}$
and $sec(x) = \frac{1}{cos(x)}$
Doing so will easily give you a common denominator on the left side of the = sign...
3. well i'm afraid i've never tried that....if u know some other method to get this done then plz try that out...
4. Hello, snigdha!
If you know this identity: . $\sec^2\!x - \tan^2\!x \:=\:1$, here's another approach.
Prove: / $\frac{1- \tan x + \sec x)}{1+\tan x + \sec x} \:=\: \frac{\cos x}{1+\sin x}$
We have: . $\frac{1 + \sec x - \tan x}{1 + \sec x +\tan x}$
Multiply by $\frac{\sec x + \tan x}{\sec x + \tan x}\!:\qquad \frac{\sec x + \tan x}{\sec x + \tan x} \cdot\frac{1 + \sec x - \tan x}{1 + \sec x + \tan x}$ . $\;\;=\;\; \frac{(\sec x + \tan x) + (\sec x + \tan x)(\sec x - \tan x)}{(\sec x + \tan x)(1 + \sec x + \tan x)}$
. . . . . $=\; \frac{(\sec x + \tan x) + \overbrace{(\sec^2\!x - \tan^2\!x)}^{\text{This is 1}}}{(\sec x+\tan x)(1 + \sec x +\tan x)}$ . $=\;\;\frac{\overbrace{\sec x + \tan x + 1}^{\text{These cancel}}}{(\sec x + \tan x)\underbrace{(1 + \sec x +\tan x)}_{\text{These cancel}}}$
. . . . . $=\; \frac{1}{\sec x + \tan x} \;\;=\;\;\frac{1}{\frac{1}{\cos x} + \frac{\sin x}{\cos x}}$
Multiply by $\frac{\cos x}{\cos x}\!:\qquad \frac{\cos x}{\cos x}\cdot \frac{1}{\frac{1}{\cos x} + \frac{\sin x}{\cos x}} \;=\; \frac{\cos x}{1 + \sin x}$
5. Hello snigdha
Originally Posted by snigdha
(1- tan x + sec x)/(1+tan x + sec x) = cos x/(1+sin x)
... and here's an approach that just uses sines and cosines.
$\frac{1-\tan x +\sec x}{1+\tan x + \sec x}=\frac{1-\tan x +\sec x}{1+\tan x + \sec x}\times\frac{\cos^2x}{\cos^2x}$
$=\frac{\cos x(\cos x-\sin x +1)}{\cos^2x+\cos x(\sin x + 1)}$
$=\frac{\cos x(\cos x-\sin x +1)}{1-\sin^2x+\cos x(\sin x + 1)}$
$=\frac{\cos x(\cos x-\sin x +1)}{(1+\sin x)(1-\sin x)+\cos x(\sin x + 1)}$
$=\frac{\cos x(\cos x-\sin x +1)}{(1+\sin x)(1-\sin x+\cos x)}$
$=\frac{\cos x}{1+\sin x}$
6. Soroban and Grandad did it again wih EASE, wow!
!
7. Originally Posted by pacman
Soroban and Grandad did it again wih EASE, wow!
!
... That's what comes of a lifetime of useless activity! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 17, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9861385822296143, "perplexity": 3167.722930980416}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1409535923940.4/warc/CC-MAIN-20140909030308-00011-ip-10-180-136-8.ec2.internal.warc.gz"} |
https://asmedigitalcollection.asme.org/ICONE/proceedings-abstract/ICONE16/48175/817/331799 | The amendment of nuclear reactors regulation law was established and the clearance system was introduced in 2005 in Japan.
This content is only available via PDF. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8496190309524536, "perplexity": 1431.2534704107284}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662556725.76/warc/CC-MAIN-20220523071517-20220523101517-00760.warc.gz"} |
http://mathhelpforum.com/calculus/214130-integrate-e-x-1-e-2x-1-2-dx-print.html | # Integrate e^x(1-e^2x)^(1/2)dx
• March 2nd 2013, 10:25 PM
verasi
Integrate e^x(1-e^2x)^(1/2)dx
Hi, I was wondering if you guys could check my work for indefinite integral of (e^x)(sqrt{1-e^2x)
Let u=e^x
The integral becomes:
integral of sqrt(1-u^2)
Then I do trigonometric substitution where I let u=sinx, and I get:
1/2sin^-1(x) + (x/2)*(1 - x^2)^1/2 + c.
However, the answer in my textbook is -1/3(1-e^(2x))^(3/2).
I was just wondering what I did wrong for the question.
If my complete process is wrong, what should I have done to solve the question?
• March 2nd 2013, 11:51 PM
JJacquelin
Re: Integrate e^x(1-e^2x)^(1/2)dx
Hi !
there is a mishmash in your answer because the same symbol x is used for two different variables :
u=e^x
u=sinx
leading to e^x=sinx which is false.
• March 3rd 2013, 02:18 AM
ibdutt
Re: Integrate e^x(1-e^2x)^(1/2)dx
You are just right put e^x=u that gives e^x dx = du
the question becomes integral of (1-u^2)^1/2 du and that is a standard for for which the integral is given by
(a^2-x^2)^1/2 = x/2 (a^2-x^2)^1/2 + 1/2 a^2 sin^-1 (x/a) + C
• March 3rd 2013, 07:48 AM
Soroban
Re: Integrate e^x(1-e^2x)^(1/2)dx
Hello, verasi!
Quote:
$\int e^x \sqrt{1-e^{2x}}\,dx$
We have: . $\int \sqrt{1-e^{2x}}\,(e^x\,dx)$
Let $u = e^x \quad\Rightarrow\quad du = e^x\,dx$
Substitute: . $\int \sqrt{1-u^2}\,du$
Let $u = \sin\theta \quad\Rightarrow\quad du = \cos\theta\,d\theta$
Substitute: . $\int \sqrt{1-\sin^2\!\theta}\,\cos\theta\,d\theta \;=\;\int\cos^2\!\theta\,d\theta \;=\;\tfrac{1}{2}\int(1 + \cos2\theta)\,d\theta$
. . . . . . . . $=\;\tfrac{1}{2}\left(\theta + \tfrac{1}{2}\sin2\theta\right) + C \;=\;\tfrac{1}{2}(\theta + \sin\theta\cos\theta) + C$
Back-substitute: . $\tfrac{1}{2}\left(\arcsin u + u\sqrt{1-u^2}\right) + C$
Back-substitute: . $\tfrac{1}{2}\left(\arcsin e^x + e^x\sqrt{1-e^{2x}}\right) + C$
• March 3rd 2013, 03:28 PM
verasi
Re: Integrate e^x(1-e^2x)^(1/2)dx
Thanks for the reply, I guess my initial answer was right then. Apparently the textbook has a different answer. It's -1/3(1-e^(2x))^(3/2).
I'm guessing the textbook used a different method then (integrate by part maybe? I didn't try it seemed way too complicated).
T.T wasted 30min on this question trying to figure out what I did wrong
• March 3rd 2013, 10:14 PM
JJacquelin
1 Attachment(s)
Re: Integrate e^x(1-e^2x)^(1/2)dx
Quote:
Originally Posted by verasi
Thanks for the reply, I guess my initial answer was right then. Apparently the textbook has a different answer. It's -1/3(1-e^(2x))^(3/2).
I'm guessing the textbook used a different method then (integrate by part maybe? I didn't try it seemed way too complicated).
T.T wasted 30min on this question trying to figure out what I did wrong
Hi!
Fortunately, any different method leads to the same result ! The results are different if there is a mistake somewhere (in calculus or if the integrals are not the same) See attachment : | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 9, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9897642731666565, "perplexity": 2315.672615991238}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464049282327.67/warc/CC-MAIN-20160524002122-00217-ip-10-185-217-139.ec2.internal.warc.gz"} |
http://openstudy.com/updates/55aae122e4b0ce1056595f9a | Here's the question you clicked on:
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anonymous one year ago PRE-CALCULUS: Find the exact value of cos-1 the quantity square root of three divided by two. Delete Cancel Submit
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1. anonymous
• one year ago
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$\cos^{-1} \left( \frac{ \sqrt{3} }{ 2} \right)$
2. anonymous
• one year ago
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we know that the range arccos(x) is 0 ≤ x ≤ π/2 ==> 0° ≤ x ≤ 180°. So we need to find the solution to cos(x) = -√3/2 this in the range of [0°, 180°]. If we construct a 30-60-90 triangle, we see that the 30° angle corresponds to this and so the angle required is x = 180° - 30° = 150°. Thus, arccos(-√3/2) = 150° = 5π/6. Answer provided by Yahoo Answers :)
3. anonymous
• one year ago
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The answer amber provided was for $\sf \large-\frac{\sqrt{3}}{2}$ by the way
4. anonymous
• one year ago
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I think your answer is wrong, but the way you explain it is right.
5. anonymous
• one year ago
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6. anonymous
• one year ago
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The easiest way to go about this sort of problem is simply to utilize the unit circle.
7. anonymous
• one year ago
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For cos, the range is 0<y<pi, right?
8. anonymous
• one year ago
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Yes, I actually based my answer on the unit circle. My answer is $\frac{ \pi }{ 6 }$
9. campbell_st
• one year ago
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here is a triangle |dw:1437262431290:dw| so the cosine of which angle is $\cos(?) = \frac{\sqrt{3}}{2}$
10. anonymous
• one year ago
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It is 30 degrees.
11. anonymous
• one year ago
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right @campbell_st ?
12. campbell_st
• one year ago
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that's correct...
13. campbell_st
• one year ago
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you just need to remember the exact value triangles... I always think about the longest side is opposite the largest angle 2 = 90 1 = 30 shortest and smallest angle
14. anonymous
• one year ago
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@campbell_st Oh, I don't that one. It is Geometry. Thanks for the help! :)
15. campbell_st
• one year ago
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it is a property from geometry that can be applied to any triangle.. so its handy to know for trig... seeing trig is about triangle measurements
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Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9994408488273621, "perplexity": 5999.032037092235}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988719908.93/warc/CC-MAIN-20161020183839-00099-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://openmdao.org/newdocs/versions/latest/features/core_features/working_with_components/units.html | # Specifying Units for Variables¶
As we saw in Declaring Continuous Variables, we can specify units for inputs, outputs, and residuals. There is a units argument to add_input to specify input units, and there are units and res_units arguments on add_output to specify output and residual units, respectively. A complete listing of all available units is given here.
Note
Residual units, if not specified, default to the same units as the output variable. res_units is very rarely specified.
Specifying units has the following result:
1. Unit conversions occur during data passing. For instance, let’s say we have a TimeComp component that outputs time1 in hours and a SpeedComp component takes time2 as an input but in seconds. If we connect TimeComp.time1 to SpeedComp.time2 with hours/seconds specified during the corresponding add_output/add_input calls, then OpenMDAO automatically converts from hours to seconds.
2. The user always gets/sets the variable in the specified units. Declaring an input, output, or residual to have certain units means that any value ‘set’ into the variable is assumed to be in the given units and any time the user asks to ‘get’ the variable, the value is return in the given units. This is the case not only in <Component> methods such as compute, apply_nonlinear, and apply_linear, but everywhere, including the user’s run script.
3. In add_input and add_output, all arguments are assumed to be given in the specified units. In the case of add_input, if units is specified, then val is assumed to be given in those units. In the case of add_output, if units is specified, then val, lower, upper, ref, and ref0 are all assumed to be given in those units. Also in add_output, if res_units is specified, then res_ref is assumed to be given in res_units.
## Units syntax¶
Units are specified as a string that adheres to the following syntax. The string is a composition of numbers and known units that are combined with multiplication (*), division (/), and exponentiation (**) operators. The known units can be prefixed by kilo (k), Mega (M), and so on. The list of units and valid prefixes can be found in the units library.
For example, each of the following is a valid unit string representing the same quantity:
• N
• 0.224809 * lbf
• kg * m / s ** 2
• kg * m * s ** -2
• kkg * mm / s ** 2
Note
If units are not specified, or are specified as None then the variable is assumed to be unitless. If such a variable is connected to a variable with units, the connection will be allowed, but a warning will be issued.
## Example¶
This example illustrates how we can compute speed from distance and time given in km and h using a component that computes speed using m and s.
We first define the component.
import openmdao.api as om
class SpeedComp(om.ExplicitComponent):
"""Simple speed computation from distance and time with unit conversations."""
def setup(self):
def compute(self, inputs, outputs):
outputs['speed'] = inputs['distance'] / inputs['time']
In the overall problem, the first component, c1, defines distance and time in m and s. OpenMDAO handles the unit conversions when passing these two variables into c2, our ‘SpeedComp’. There is a further unit conversion from c2 to c3 since speed must be converted now to m/s.
import openmdao.api as om
from openmdao.core.tests.test_units import SpeedComp
prob = om.Problem()
prob.model.set_input_defaults('c1.distance', val=1., units='m')
prob.model.set_input_defaults('c1.time', val=1., units='s')
prob.model.connect('c1.speed', 'c2.speed')
prob.setup()
prob.run_model()
print(prob.get_val('c1.distance')) # units: km
[0.001]
print(prob.get_val('c1.time')) # units: h
[0.00027778]
print(prob.get_val('c1.speed')) # units: km/h
[3.6]
print(prob.get_val('c2.f')) # units: m/s
[1.] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8472608923912048, "perplexity": 3092.2369948174914}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320305420.54/warc/CC-MAIN-20220128043801-20220128073801-00282.warc.gz"} |
https://aviation.stackexchange.com/questions/26479/what-is-the-status-of-notes-in-icao-annexes | # What is the status of “Notes” in ICAO Annexes?
As per the forward to ICAO Annex 11, the status of a "NOTE" in any annex is - "Notes included in the text, where appropriate, to give factual information or references bearing on the Standards or Recommended Practices in question, but not constituting part of the Standards or Recommended Practices." So, does it mean, a note given in the Annex does not hold any authority as it is not a part of the SARPs ? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8473207950592041, "perplexity": 2160.630775016607}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987835748.66/warc/CC-MAIN-20191023173708-20191023201208-00427.warc.gz"} |
https://stats.stackexchange.com/questions/291242/how-do-i-get-the-hazard-rate-from-a-cox-proportional-hazard-model | # How do I get the hazard rate from a Cox Proportional Hazard model?
I'm using the lifelines Python package to learn Cox Proportional Hazard (CPH) model. What I need now is to feed it new examples and generate the predicted hazard rate (the probability of the event occuring at time t, given that the person has survived up to time t). (BTW, sorry if I'm getting my terms mixed up between hazard rate and hazard function, but either way, I need a probability of the event happening from the CPH model).
I tried the CoxPHFitter.predict_partial_hazard(), but the values coming back are exceeding the range of [0, 1]. For example, I'm seeing values as high as 11.028 or 60,326.305. This leads me to believe that this value being returned is not the hazard rate (of course, the code documents that this is just the partial hazard). As I stated before, the hazard rate is a probability, and obviously, this value exceeds the bounds of [0, 1]. Anyone know if I get the the hazard rate using this Python package?
Additionally, if there's anyway to do this in R, I'm willing to try that too.
There is a similar question here, but it focuses on R and also the accepted answer did not even answer the question, IMO.
Author of the lifelines library here. Here is the details as of v0.14.4.
To help, let's review the from the the CoxPH model in lifelines:
$$\lambda(t | x) = \overbrace{b_0(t)}^{\text{baseline}}\underbrace{\exp \overbrace{\left(\sum_{i=1}^n \beta_i x_i \right)}^{\text{log-partial hazard}}}_ {\text{partial hazard}}$$
The partial hazard in the CoxPH model is the $\exp(...)$ part, so I don't expect it to be between 0 and 1.
As I stated before, the hazard rate is a probability
This is the case in some discrete model (Nelson Aalen model for example), but not true in the Cox model.
What I need now is to feed it new examples and generate the predicted hazard rate (the probability of the event occuring at time t, given that the person has survived up to time t).
To do this, here is what I am thinking. Each individual will have a survival curve sf = predict_survival_function(individual), and we can produce the conditional survival function for an individual and compute the delta probability between two points to answer "what is the probability the event occurs in this time period?".
• Could you please clarify? A data frame is passed back; are the values under the 0 column the survival probabilities and the row indexes the time intervals (e.g. years)? If I had the survival passed back for an individual who's in his 1st year, could I filter for the closest points in time e.g. indices = [index for index in scurve.index if 0.95 <= index <= 1.01] and take the difference of the last 2 survival probabilities as the probability of the event in this time period? – Jane Wayne Jul 12 '17 at 21:27
• And also, if I needed to get his survival probability 2 years out (e.g. 3 years), I would filter out again indices = [index for index in scurve.index if 2.95 <= index <= 3.01] and take the difference between the last 2 probabilities. What I am trying to produce is, what is the current probability of the event now, and 1, 2, 3, etc... years out? Does these approaches make sense? – Jane Wayne Jul 12 '17 at 21:31
• Now that I'm thinking about it and doing some code, if I wanted to know the probability of failure at year 1, 2, 3, etc... can't I just find the closest row index value, take its corresponding survival probability, and do 1 - survival_probability to get event probability? – Jane Wayne Jul 12 '17 at 22:00
• Your comments are all reasonable. For your latest comment, yes, but now your interpretation of " if I wanted to know the probability of failure at year 1, 2, 3..." is "the probability of the event before year 1, 2, 3...". It's not necessarily the probability of event on year 1, 2, 3. – Cam.Davidson.Pilon Jul 13 '17 at 0:32 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6807406544685364, "perplexity": 508.8112160666946}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038076819.36/warc/CC-MAIN-20210414034544-20210414064544-00413.warc.gz"} |
https://zbmath.org/?q=ai%3Alukashevich.n-a+cc%3A65 | ×
# zbMATH — the first resource for mathematics
Investigation of an approximate solution of the second Painlevé equation. (Russian) Zbl 0692.34010
The equation (1) $$y''=2x^ 3+xy+\alpha$$, $$y(x_ 0)=y_ 0$$, $$y'(x_ 0)=y_ 1$$ is studied. There is given a method for numerical evaluation of singular points of (1).
Reviewer: M.Bartušek
##### MSC:
65J99 Numerical analysis in abstract spaces 65L05 Numerical methods for initial value problems
##### Keywords:
numerical evaluation of singular points | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8707522749900818, "perplexity": 1512.9818913922063}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610703581888.64/warc/CC-MAIN-20210125123120-20210125153120-00043.warc.gz"} |
https://physicsfromplanetearth.wordpress.com/2016/09/ | # Gravitational Radiation 3: GW151226, Encore from LIGO
LIGO (Laser Interferometer Gravitational-Wave Observatory) consists of two gargantuan Michelson-like interferometers, with arms 4 km long, located 3000 km apart in Livingston LA and Hanford WA. Its first observing session began on September 12, 2015. Incredibly, just two days later, it captured the fleeting signal (designated GW150914) produced by the merger of two inspiraling black holes more than 1 billion light years from Earth. (Ref. 1) That groundbreaking discovery, announced on February 11, 2016, ended a 60 year race to directly detect gravitational waves, and came 100 years after the phenomenon was first predicted by Albert Einstein.
On Christmas Day (in the USA), LIGO scientists detected a second event, GW151226 (Ref. 3), proving that the earlier discovery was not a fluke, and that black hole mergers are frequent events. (Ref. 4,5) Since January, LIGO’s sensitivity has been improved, and it will begin a new observing run in Autumn, 2016. This time, the two US detectors will be joined by VIRGO, a similar instrument with arms 3 km long, located near Pisa, Italy. The addition of VIRGO will greatly assist in localizing – by triangulation – the sources of gravitational radiation. In the near future, when LIGO and VIRGO reach their full design sensitivities, they may be capable of detecting one or more black hole collisions daily! Indeed, the 21st Century seems destined to become the era of gravitational wave astronomy.
In this brief post, we will use the mathematical treatment outlined in Ref. 2 to analyze the published data given in Ref. 3 for GW151226. Our educational goal is to add to the collection of homework exercises related to gravitational waves that are suitable for first year physics students. In this way, we hope to inspire instructors to include this exciting topic in their mechanics syllabi.
## Analyzing GW151226
In Ref. 2, the chirp mass of the binary black hole system was defined as $\large \mathfrak{M}=\frac{(m_{1}m_{2})^{3/5}}{(m_{1}+m_{2})^{1/5}}$, where $\large m_{1}$ and $\large m_{2}$ are the masses of the black holes. This quantity is important because it can be found directly from the time dependence of the gravitational wave’s (GW) frequency (Eqn. 10 of Ref. 2):
$\large \mathfrak{M}=\frac{c^{3}}{G}\left ( \frac{5}{96}\: \pi ^{-8/3}f^{-11/3}\: \frac{df}{dt} \right )$ .
(1)
Following Ref. 2, define $\large A=\frac{c^{5}}{G^{5/3}}\: \frac{5}{96}\: \pi ^{-8/3}=5.45\times 10^{56}$ (SI units), and integrate Eqn. 1 over the time interval $\large \Delta t=t_{2}-t_{1}$ to obtain
$\large \mathfrak{M}^{5/3}\Delta t=A\int_{t_{1}}^{t^{_{2}}}f^{-11/3}df=-\frac{3}{8}Af^{-8/3}\mid _{t_{1}}^{t_{2}}$ .
(2)
1. Referring to Fig. 1 above, at 0.80 s before the two black holes coalesce, the frequency of the GW was 39.2 Hz. Later, 0.40 s before the merger, the frequency was 50.3 Hz. (Ref. 6) Calculate the chirp mass and express your answer in terms of $\large M_{Sun}$. (Ans: $\large 9.7\: M_{Sun}$.)
2. Show that the total mass $\large M=m_{1}+m_{2}$ of the binary system before coalescence was at least $\large 22\: M_{Sun}$. (Hint: Let $\large m_{2}=\alpha m_{1}$. Express $\large M$$\large \mathfrak{M}$, and $\large M/\mathfrak{M}$ in terms of $\large m_{1}$ and $\large \alpha$. Show that the ratio is a minimum when $\large \alpha=1$.)
3. The GW frequency at the moment of coalescence of the two black holes was 420 Hz. (See Fig. 1.) Recall from Ref. 2 that the orbital frequency of the binary system is half the frequency of the GW. Use the total mass given in Ref. 3, $\large M=22\: M_{Sun}$, to find the distance between the bodies just before they merged. (Ans: 120 km)
4. Assume that one black hole was twice as massive as the other, i.e., $\large m_{2}=2m_{1}$, which is about what the LIGO team concluded. If the orbits were circular, what were their radii just before coalescence? What were their speeds? Ignore relativity. (Ans: 40 and 80 km; $\large v_{1}=0.35\, c$)
References:
1. B. P. Abbott et al, “Observation of Gravitational Waves from a Binary Black Hole Merger,”, Phys. Rev. Lett. 116, 061102 (2016)
2. this blog: “Gravitational Radiation 2: The Chirp Heard Round the World”
3. B. P. Abbott et al, “Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence,”, Phys. Rev. Lett. 116, 241103 (2016)
4. A. Cho, “LIGO Detects Another Black Hole Crash,” Science 352, 1374, 17 June 2016
5. D. Castelvecchi, “LIGO Sees a Second Black Hole Crash,” Nature 534, 448, 23 June 2016
6. We thank Jonah Kanner at the LIGO Open Science Center for providing these numbers, which were calculated using the tutorial on the Center’s webpage: https://losc.ligo.org. The numbers obtained from the tutorial differ slightly from those reported in Ref. 3 because the analysis is not identical to the one used for the paper. (In Ref. 3, $\large \mathfrak{M}=8.9\pm 0.3\: M_{Sun}$.) The LIGO Open Science Center is a service of LIGO Laboratory and the LIGO Scientific Collaboration. LIGO is funded by the U.S. National Science Foundation.
# Proxima Centauri b: An Earth-like Neighbor in our Galactic backyard
In August (2016), astronomers at the European Southern Observatory in Chile announced the discovery of an Earth-sized exoplanet orbiting the red dwarf Proxima Centauri, the nearest star to our Sun (Ref. 1, 2). The planet, called Proxima Centauri b, was detected by the radial velocity method: the orbiting planet causes the star to execute a much smaller orbit of its own (as required by momentum conservation), and light from the star is Doppler-shifted due to its radial motion relative to Earth. The discovery of Proxima Centauri b is exciting because its orbit lies within the “Goldilocks,” or temperate, zone of the star, where the planet’s surface temperature would allow water to exist in liquid form – a likely prerequisite for life. Red dwarfs are the most common stars in our galaxy, so if this particular red dwarf harbors a life-supporting planet, it is likely that the Milky Way, which contains over 100 billion stars, is brimming with life.
In this post, we will use the data reported in Reference 1, plus the strategy presented in Section 8.12 of PPE, to calculate the mass and orbital radius of the exoplanet Proxima Centauri b. Our goal is to help students share the excitement of this new discovery through their understanding of introductory mechanics.
## A. Calculating the exoplanet’s mass and orbital radius
In the following, we will assume $\large m\ll M$, where $\large m$ and $\large M$ are the masses of the planet and star, respectively. We will also assume that their orbits are circular, which is consistent with observations, and begin by treating the simplest case where the orbits are viewed edge-on from Earth. (Later, we’ll relax this restriction.) Radial velocity measurements of Proxima Centauri collected over the past 16 years are compiled in Figure 2. Careful analysis indicates that the period $\large T$ of the star’s orbit is 11.186 ± .002 d, and its orbital speed $\large v$ is 1.38 ± 0.02 m/s.
Kepler’s 3rd law states that
$\large \frac{T^{2}}{r^{3}}=\frac{4\pi ^{2}}{GM}$,
where $\large r$ is the orbital radius of the planet. Observations of the star’s luminosity and color indicate that its mass $\large M=0.120\pm .015\, M_{Sun}$.
1. Find the planetary orbit radius $\large r$ (in AU). Hint: use $\large T=11.186/365.25=.03063\, \mathrm{yr}$ and $\large r^{3}\propto MT^{2}$ to compare this orbit to Earth’s orbit about the Sun. (Ans: $\large 0.048 \: \mathrm{AU} = 7.24\times 10^{9}\: \mathrm{m}$.
2. The orbital radius of the star $\large R$ can be found from its period and radial velocity $\large v$$\large vT=2\pi R$. Using $\ 1\: \mathrm{d}=8.64\times 10^{4}\: \boldsymbol{\mathrm{s}}$, find $\large R$. (Ans: $\large 2.12\times 10^{5}\: \mathrm{m}$)
3. The planet and star co-orbit their center of mass. Find the mass of the exoplanet. (Ans: $\large m=MR/r=2.93\times 10^{-5}\, M=6.99\times 10^{24}\, \mathrm{kg}=1.18\, m_{Earth}$)
If the orbit is not viewed edge-on, but is inclined to the line of sight (LOS), the measured radial speed of the star is less than the actual orbital speed $\large v$ used in the above analysis: $\large v_{meas}=vsin(i)$, where i, the angle of inclination, is unmeasurable. See Figure 3. In this case, $\large 2\pi R=Tv=Tv_{meas}/sin(i))$.
4. Prove that, in the general case, the radial velocity measurements are only sufficient to determine $\large msin(i)$. Is the exoplanet mass you found in Question 3 the maximum, or minimum, mass of the planet?
5. Because red dwarfs are much cooler than the Sun, their temperate zones are much closer to them than the Earth is to the Sun. In addition, red dwarfs are less massive than the Sun. Explain why both of these factors favor the detection of small habitable exoplanets. (See Ref. 2 for a brief discussion.)
6. Proxima Centauri subtends an angle of 1.02 ± .08 mas (milliarcseconds) when viewed from Earth. (See PPE, Section 1.7) Find its radius $\large R_{s}$. (Ans: $\large 1.0\times 10^{8}\: \mathrm{m}=0.14\, R_{\mathrm{Sun}}$)
If Proxima centauri b transits, or passes in front of, its star, as viewed from Earth, it will intercept some of the starlight and allow its radius to be determined. Additionally, if the planet has an atmosphere, it will absorb certain wavelengths of light preferentially, enabling astronomers to detect the presence of atmospheric gases such as water, oxygen, carbon dioxide, and methane. Methane (CH4), in particular, is often associated with the presence of life.
The probability of transit is found from the geometric argument outlined in Figure 4. In the figure, the horizontal dotted line is the LOS from Earth, and the vertical line represents the plane perpendicular to the LOS passing through the star’s center. For an orbit to be transiting, its normal (shown as a red line for each of the two orbits depicted) must lie within $\large \pm \theta _{max}=\pm R_{s}/r$ of the vertical plane, where $\large R_{s}$ is the star’s radius. But the normal to the orbit does not need to lie in the plane of the figure: any transiting orbit rotated by any angle (0 – 2π) about the LOS would remain a transiting orbit. The total solid angle available for transiting orbits is therefore $\large 2\pi \cdot 2\theta _{max}=4\pi R_{s}/r$, whereas the total solid angle associated with all possible orientations is $\large 4\pi$. Therefore, the probability of a transiting orbit is $\large R_{s}/r$. (Check: if $\large r=R_{s}$, then the probability equals 1.) For a fuller discussion, see http://kepler.nasa.gov/Science/about/characteristicsOfTransits/ .
7. How probable is it that Proxima Centauri b transits its star? (Ans: 1.5%)
## B. How Warm is Proxima Centauri b?
The following questions are only suitable for students who have studied blackbody radiation in a course of thermal physics.
8. The luminosity of a star (its total radiated power) is proportional to its surface area and the fourth power of its surface temperature: $\large L_{star}\propto R_{star}^{2}T_{star}^{4}$. Proxima Centauri’s surface temperature is about 3050 K, whereas the Sun’s is 5780 K. Show that $\large L_{Proxima}\simeq 0.0015\, L_{Sun}$. This indicates that the temperate zone lies much closer than 1 AU to the star.
9. The fraction of the star’s radiation that is intercepted by a planet is equal to the solid angle subtended by the planet divided by 4π: $\large \pi R_{p}^{2}/4\pi r^{2}$. The absorbed radiation warms the planet, which reaches a steady state temperature $\large T_{p}$ when the blackbody radiation emitted by the planet equals the radiation absorbed from the star:
$\large 4\pi R_{p}^{2}\sigma _{B}T_{p}^{4}=L_{Proxima}\pi R_{p}^{2}/4\pi r^{2}$, where $\large \sigma _{B}$ is called the Stefan-Boltzmann constant. (Its value is not needed to answer this question.) Use this information to compare the surface temperature of Proxima Centauri b to that of the Earth, assuming both planets are perfect black bodies (or have the same albedo). (Ans: $\large T_{p}/T_{Earth}=0.90$)
References
1. G. Anglada-Escudé et al, Nature 536, 437 (25 August, 2016)
2. A. P. Hatzes, Nature 536, 408 (25 August, 2016) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 60, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8541509509086609, "perplexity": 2746.6967839462477}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891814311.76/warc/CC-MAIN-20180223015726-20180223035726-00730.warc.gz"} |
https://utsv.net/solid-mechanics/4-stress/cauchy-equation-of-motion | Cauchy Equation of Motion
The equation of motion can be expressed in terms of the applied stress, body forces, mass, and acceleration:
(1)
In index notation: ;
or
(2)
Eq. 2 is the continuum mechanics version of Newton’s Second Law, often called the balance of linear momentum.
Note that the step from eq. 1 to eq. 2 is not trivial, since both and do in fact change with time. The complete derivation, starting with eq. 1 and concluding with eq. 2, is given in Appendix B.2. [Holzapfel] calls this derivation (operation) the “material time derivative of a spatial field.”
Thus,
(3)
Note that the “localization theorem” states that , if and are arbitrary.
(4)
Eq. 4 are the Cauchy Equations of Equilibrium. It may not yet be clear which term contains the applied forces and which term contains the quantities analogous to “.” It turns out that the term will contain applied forces and prescribed displacements, along with all of the internal force and displacement quantities that constitute “” for the element. When an entire system is analyzed, which includes many elements, the global equation of motion should be satisfied, naturally, so long as the geometry is accurately represented by the elements, the stiffness and strength properties of the material are defined for each element, and the boundary conditions are correctly assigned for each element. There could be other issues that arise as well, due to simplifications inherent (but quite necessary) in the finite element analysis method (FEA), but these issues will be left to texts that cover FEA in detail. In fact, among the aforementioned element-related issues, this text will only cover material elastic stiffness in detail. Material behavior at the limit state (failure) is covered in texts on plasticity, for example, and topics relating to element geometries, prescribed degrees of freedom or prescribed forces at “nodes” (i.e. boundary conditions), or other issues related to the “assembly” of finite elements will be left to texts devoted to the topic of FEA implementation.
. then eq. 4 reduces to static equilibrium. An alternative derivation of stress equilibrium, which doesn’t use index notation, can be found in [Ugural].
note: This is the basic differential equation used in FEA, though the connection to FEA will not really be clear until we start developing constitutive equations relating stresses and strains (along with the above equation and strain-displacement relationships previously presented). | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8828898668289185, "perplexity": 635.3041654347481}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547583874494.65/warc/CC-MAIN-20190122202547-20190122224547-00105.warc.gz"} |
https://www.eevblog.com/forum/blog/eevblog-1218-1ghz-oscilloscope-spec-shootout/25/?PHPSESSID=ffb59t0occ8978osuvmkea1i27 | ### Author Topic: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout (Read 12950 times)
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#### Dubbie
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #25 on: June 13, 2019, 03:40:41 am »
Anything less was practically unheard of except on portable devices.
Like a scope for example?
#### EEVblog
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #26 on: June 13, 2019, 08:27:36 am »
Dave mentioned something in the video about zone triggers. When I bought my scope I didn’t think I would get much use from them. Turns out I use them all the time. One thing they are great for is a really fast way to set up a trigger hold off. Just draw an exclude box to the left of your trigger point. The are tons of dumb tricks like that which can be done the “proper” way with other triggers, but when you’re in the flow you can do a ton with on-the-fly zone triggers. Anyone else use them like this?
Guilty!
It's almost the equivalent of the lazy man's AutoSet button
#### EEVblog
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #27 on: June 13, 2019, 08:32:01 am »
One problem may be the data mapping system.
Keysight for example have a fixed 800x600 in the ASIC, and map samples to the screen all inside the ASIC.
So you'd have to have 1080p built into the mapping system from the get-go with a fast data path
Limiting an ASIC to an ancient 800x600 seems to be a big overlook in future planning? If I were designing it, I would probably pick 1080p or 2.5K as the limit since LCDs with those resolutions are very common. Maybe even 4K to really be futureproof - ASICs are expensive to design but (relatively) cheap to manufacture.
The Megazoon IV ASIC was released in Feb 2011
https://www.embedded.com/electronics-news/4213152/Agilent-uses-new-ASIC-in-MSO-market-attack
I think I once calculated that the Megazoom chips had been released every 6 years before that (so we are well overdue now BTW).
That puts the original development starting probably around 2005-2006
So 800x600 would have been plenty for that time period.
#### EEVblog
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #28 on: June 13, 2019, 08:38:28 am »
It doesn't matter when you do the comparison, it's always going to be "unfair" to someone.
True, but
It's true so therefore you don't get any buts!
If I did it tomorrow there'll be another but, and another after that and another after that.
Quote
at this very point, only the 1GHz model of the RTM3K is drastically discounted. Actually, while many of us dream of a >= 1GHz scope, very few hobbyists will be willing to invest >= 10k-20k USD/€.
Who said it was aimed at hobbyists?
Quote
So a 500MHz shootout would have been probably more interesting for the target audience and also a logical step when including the MSO7000. And when comparing the 500MHz models right now, even the base model RTM3k-54 (without MSO option) costs more than twice as much as an SDS5054X.
So 500MHz is hobbyist price friendly but 1GHz is not?
Sorry, not buying it.
Why 500Mhz? Why not 350MHz so we can include the popular R&S RTB2000?
The shootout options will always be endless, my video is what it is.
Quote
Besides, the current Rigol discount for the DS7000/MSO7000 doesn't only include all options, but also a frequency upgrade for the 250MHz and 300MHz models.
https://www.rigol.eu/promos/
So buying a MSO7054 ($11299) instead of an MSO7034 ($8299) would make as much sense as buying the RTM3K base model right now.
Sure, like I said in the videos, there are always differences in pricing and deals and countries etc. Always re-do your own local price evaluation!
#### EEVblog
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #29 on: June 13, 2019, 08:42:08 am »
That ASIC’s specs were probably set almost 15 years ago. 800x600 probably seemed extravagant at the time.
1024x768 was a common resolution for laptops back then, with 1280x1024 being common on desktops and higher end laptops. Anything less was practically unheard of except on portable devices.
But nobody was doing that on a small screen which is what all bench scopes were using back then. Only very recently, almost 15 years later have we started getting large screen bench scopes like the Tek 3&4 Series. And even then they are essentially creating a different market segment to the smaller screen bench scopes.
#### nctnico
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #30 on: June 14, 2019, 06:17:03 am »
The Keysight DSO/MSO7000 series, some Lecroys and Tektronix TDS5000/TDS7000 all have 10" (-ish) screens.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #31 on: June 14, 2019, 03:37:09 pm »
The Agilent 7000 series had a 12.1" XGA (1024x768) screen around 2009.
LeCroy had 12.1" WXGA (1280 x 800) screens in their medium range models (6Zi) back in 2011. They had 10" screens with lower resolutions way before that. E.g. Wavepro 950 had a 10.4" LCD but only with VGA (640x480) resolution.
Trying is the first step towards failure - Homer J. Simpson
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #32 on: June 15, 2019, 01:43:29 am »
The Agilent 7000 series had a 12.1" XGA (1024x768) screen around 2009.
LeCroy had 12.1" WXGA (1280 x 800) screens in their medium range models (6Zi) back in 2011. They had 10" screens with lower resolutions way before that. E.g. Wavepro 950 had a 10.4" LCD but only with VGA (640x480) resolution.
Yes, but I was really referring to lower end scopes.
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #33 on: June 15, 2019, 09:27:10 am »
The Agilent 7000 series had a 12.1" XGA (1024x768) screen around 2009.
LeCroy had 12.1" WXGA (1280 x 800) screens in their medium range models (6Zi) back in 2011. They had 10" screens with lower resolutions way before that. E.g. Wavepro 950 had a 10.4" LCD but only with VGA (640x480) resolution.
Yes, but I was really referring to lower end scopes.
To be fair, lower end (digital) scopes 15 years ago didn't even have LCD screens. E.g. the infamous Agilent 54600 series from around 2004 still had a 7" tube.
« Last Edit: June 15, 2019, 09:31:17 am by 0xdeadbeef »
Trying is the first step towards failure - Homer J. Simpson
#### jfedison741
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #34 on: May 11, 2021, 10:28:56 pm »
Has anyone else noticed the higher Keysight oscilloscope pricing recently? Maybe it's just my region but Keysight scope prices appear to be about 45% higher these days compared to June 2019 when Dave posted his excellent 1GHz scope comparison.
#### Fungus
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #38 on: May 12, 2021, 07:49:57 pm »
To be fair, pricing for Tektronix Series 3 didn't change at all the last two years (except at 1GHz).
Yeah, but Tek has profit margins to spare on all their stuff.
#### utogaria
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##### Re: EEVblog #1218 - 1GHz Oscilloscope Spec Shootout
« Reply #39 on: June 13, 2021, 08:30:54 pm »
To be fair, pricing for Tektronix Series 3 didn't change at all the last two years (except at 1GHz). But 500MHz still costs above US\$10k. Not surprising now how pricing (Keysight 3000X, Tektronix 3 Series) are now almost perfectly aligned. I guess we have Tektronix to "thank".
According to the latest Tekronix campaign, you can get the MDO34 350MHz (upgraded to 500MHz for free) for 4770 euros.
No measure, no truth.
Smf | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.17790789902210236, "perplexity": 14388.655375203254}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296949701.56/warc/CC-MAIN-20230401063607-20230401093607-00633.warc.gz"} |
https://brilliant.org/problems/estimating-zeta/ | # Estimating Zeta
The Riemann zeta function is defined as <br />
$$\zeta(s) = \sum_{n=1}^{\infty}\frac{1}{n ^ s} = \frac{1}{1 ^ s} + \frac{1}{2 ^s} + \frac{1}{3^s} + ...$$ <br />
We can estimate Riemann zeta values by using large numbers in place of infinity as the upper limit of the series.
Let Z be an estimation of $$100\sqrt{6\zeta(2)}$$, calculated using 1000000 as infinity.
What is Z, rounded to the nearest integer?
× | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9963352084159851, "perplexity": 1615.678237119505}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549427749.61/warc/CC-MAIN-20170727062229-20170727082229-00632.warc.gz"} |
http://www.intmath.com/blog/learning/trends-in-learning-with-technology-635 | # Trends in learning with technology
By Murray Bourne, 22 May 2007
The 2007 Horizon Report (from Educause and New Media Consortium) provides interesting insights into developing trends in educational technology.
Things are changing so quickly - and many educational institutions are not even aware of what is happening, let alone being ahead of the game, where they should be.
The 6 highlights of this year's report revolve around Web 2.0, which is not surprising.
## User-Created Content
Thinks blogs, wikis, Flickr, YouTube, etc etc. Has your school done something effective with these today?
## Social Networking
Amazon was among the first with this concept. The "user review" proved to be a powerful sales technique and spawned a huge social network that is unstoppable.
An interesting example in the education sphere is RateMyProfessor.com, which gives an insight into who relates best to students, and why.
## Mobile Phones
In Japan, it seems mobile phones are more pervasive than PCs, especially for Web connectivity. Think "just in time" learning.
## Virtual Worlds
This has huge implications for education. I remember hearing that 10 years ago, but the technology wasn't up to it then. The potential for simulation-based learning now is big.
## New Scholarship
The students are more familiar with Wikipedia than Britannica. Now that anyone can publish, skills in determining validity become essential.
## Massively Multiplayer Educational Gaming
As for virtual worlds, there is huge potential - especially across institutions, across countries and across the world.
The 2007 Horizon Report is worth a read.
So students, how do you feel about all this? Do you still prefer lectures?
Be the first to comment below.
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https://www.lmfdb.org/EllipticCurve/Q/33800d/ | # Properties
Label 33800d Number of curves 1 Conductor 33800 CM no Rank 1
# Related objects
Show commands for: SageMath
sage: E = EllipticCurve("33800.u1")
sage: E.isogeny_class()
## Elliptic curves in class 33800d
sage: E.isogeny_class().curves
LMFDB label Cremona label Weierstrass coefficients Torsion structure Modular degree Optimality
33800.u1 33800d1 [0, 1, 0, -1408, 313] [] 27648 $$\Gamma_0(N)$$-optimal
## Rank
sage: E.rank()
The elliptic curve 33800d1 has rank $$1$$.
## Modular form 33800.2.a.u
sage: E.q_eigenform(10)
$$q + q^{3} + 3q^{7} - 2q^{9} - 3q^{11} + 3q^{17} - 5q^{19} + O(q^{20})$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8933061361312866, "perplexity": 22892.938315859552}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347396495.25/warc/CC-MAIN-20200528030851-20200528060851-00174.warc.gz"} |
https://www.physicsforums.com/threads/networks-on-a-torus.51359/ | # Networks on a Torus
1. Nov 4, 2004
### Zurtex
I'm asked to consider regular networks on a torus. I'm given that V - E + F = 0. I need to show it is impossible to have a regular network on a torus where the faces are pentagons; I don't understand that at all. Surely it is easy to have pentagons as faces… All you would need to is draw a pentagon on it, please tell me where I am not getting this.
2. Nov 4, 2004
### HallsofIvy
Staff Emeritus
I suspect that what they mean is a network that completely covers the torus: every point on the torus in on or inside some pentagon.
Suppose your network consisted of n pentagons. Then there are n faces. How many edges are there? (Each pentagon has 5 edges, but each edge is shared by two pentagons.) How many vertices are there? (Each pentagon has 5 vertices but each vertex is shared by 3 pentagons.)
Now plug those numbers into the Euler equation.
3. Nov 4, 2004
Thanks
4. Nov 7, 2004
### Zurtex
Erm writing this out, I'm confused again. How can all shapes be a pentagon in a regular network anyway? Pentagons don't tessellate. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8199779987335205, "perplexity": 739.4419311359001}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501170569.99/warc/CC-MAIN-20170219104610-00479-ip-10-171-10-108.ec2.internal.warc.gz"} |
http://yuezhuang.me/2018/07/24/llvm/2018-07-24/ | Now, let us look inside CBMC and figure out how cbmc works and how does it generate VC. We first download the slides explaining the first version (v1.0) of cbmc given by Daniel. That will help us understand cbmc’s structure.
## cbmc
### 前端处理 frontend
cbmc 的目标是分析 C/C++ 或者 JAVA 程序。CBMC 的第一步是输入程序，生成 CFG。关于如何生成 CFG，是编译原理的基础课程（我们可以用 CIL 来初步处理程序获得 CFG，另外，frama-c 平台也提供了现成的模块，可以直接获取）。
cbmc aims at the analysis of programs given in a commodity
programming language such as C, C++, or Java As the first step, it transforms the program into a control flow graph (CFG)
When we have the cfg, that means we have the execution paths of the programs. Thus, we can obtain the conjunction ($\phi_{i}$) of the condition in each joint point for each path $\phi_{i}$. The path will be executed if $\phi_{i}$ is valid.
let us look at the example in the above graph. We select one path and obtain the corresponding formula. This formula should be passed to a decision procedure and we obtain a satisfying assignment or the formula is invalid.
### SAT
SAT 的求解技术能力已经有了明显的提升。目前的很多研究是提高 word-level reasoningarray decision procedures 的效率。
## Transition System
A transition system $(S, T, I)$ is defined as follows:
• a set of states $S$;
• a transition relation $T: S \rightarrow S$;
• a set of initial states $S_{0}\subseteq S$.
A program is modelled as a transition system. Each state of the program is an evaluation of all variables in the program. Each state may has many possible successors, i.e., the transition relation is non-deterministic.
Example1 : $S = \{a,b,c\}$, $I = \{a\}$ and $T = \{ \langle a,b\rangle, \langle b,b\rangle, \langle b,c\rangle\}$
## 总结
cbmc 的步骤总共有三步：
1. 前端处理，获得程序的 cfg
2. 展开 unwind cfg，获得路径的公式
3. 利用 SAT/SMT 求解公式 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 22, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9105541110038757, "perplexity": 2344.583039534158}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-43/segments/1539583510998.39/warc/CC-MAIN-20181017044446-20181017065946-00194.warc.gz"} |
http://www.analyzemath.com/Geometry/sector_circle.html | # Sectors and Circles Problems
Problems on sectors and circles with detailed solutions.
Problem 1: In the figure below, the length of arc AB is equal to twice the length of radius r of the circle. Find the area of sector OAB in terms of the radius r. Solution to Problem 1: The formula for the arc length is given by arc length AB = r * angle AOB arc length AB is given and is equal to 2r, hence 2r = r * angle AOB Solve for angle AOB to obtain angle AOB = 2 radians The area of the sector is given by Area = (1/2) * angle AOB * r 2 = (1/2) * 2 * r 2 = r 2 Problem 2: The angle of a sector in a given circle is 40 degrees and the area of the sector is equal to 20 cm 2. Calculate the arc length of the sector. Solution to Problem 2: The formula for the area of a sector is Area = (1 / 2) * angle of sector * r 2 The area and the angle are given. The angle is given in degrees and has to be converted into radians. 20 = (1 / 2) * (40 * Pi / 180) * r 2 Solve for radius r to obtain r = square root [ 2 * 20 * 180 / (40 Pi) ] = square root [ 180 / Pi ] The arc length is given by arc length of sector = angle of sector * r = [ 40 * Pi / 180 ] * square root [ 180 / Pi ] = [ Pi / 4.5 ] * square root [ 180 / Pi ] = 5.3 cm (rounded to 1 decimal place) Problem 3: In the figure below, AB and DC are arcs of concentric circles with center O. The perimeter of figure ABCD is 22 cm. Calculate a) angle AOB b) The area of figure ABCD. Solution to Problem 3: The perimeter of ABCD is given by perimeter = arc AB + 6 + arc DC + 6 = 22 If we let x be the size of the sector central angle, arc AB and arc DC are given by (formula for arc length of sector) arc AB = 2 * x and arc DC = 8 * x Substitute in the above perimeter formula 2x + 6 + 8x + 6 = 22 Solve for x x = 1 radian The area of figure ABCD is found by subtracting the area of the small sector from the area of the larger sector area of ABCD = (1 / 2) 8 2 * 1 - (1 / 2) 2 2 * 1 = 30 cm 2 More references on geometry tutorials and problems. Geometry Tutorials, Problems and Interactive Applets. Triangle Problems | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8867814540863037, "perplexity": 249.0545543247318}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-51/segments/1512948521188.19/warc/CC-MAIN-20171213030444-20171213050444-00157.warc.gz"} |
https://cs.stackexchange.com/questions/66498/prims-algorithm-on-graph-with-weights-of-only-1-and-2-on-each-edge | # Prim's algorithm on graph with weights of only $1$ and $2$ on each edge
I have this version of Prim's algorithm
Prim$(G=(V,E),s\in V,w)\\ 1.\ d(s)\leftarrow 0;\forall u \neq s:d(u)\leftarrow \infty\quad \color{red}{O(|V|)}\\ 2.\ \forall u \in V:p(u)\leftarrow \text{null}\quad \color{red}{O(|V|)}\\ 3.\ s\leftarrow \emptyset,T\leftarrow \emptyset\quad \color{red}{O(1)}\\ 4.\ Q \leftarrow \text{Makeheap}(V)\quad \color{red}{O(|V|)}\\ 5.\ \text{while}\ Q\neq \emptyset\\ 6.\qquad u\leftarrow Q.\text{ExtractMin()}\quad \color{red}{O(\log(|V|))}\\ 7.\qquad S\leftarrow S\cup\{u\},\ T\leftarrow T\cup\{(u,p(u))\}\quad \color{red}{O(1)}\\ 8.\qquad \text{for each}\ (u,z)\in E,z\in Q\\ 9.\qquad\qquad \text{if}\ d(z)>w(u,z)\ \text{then}\\ 10.\qquad\qquad\qquad Q.\text{Remove}(z);Q.\text{Insert}(z,w(u,z))\quad \color{red}{O(\log(|V|))}\\ 11.\qquad\qquad\qquad d(z)\leftarrow w(u,z),\ p(z)\leftarrow \quad \color{red}{O(1)}\\ 12.\ \text{return }T$
Total time: $O(|E|\log(|V|))$
Given a weighted, connected, simple undirected graph $G$ with weights of only $1$ and $2$ on each edge, why in this case the running time of the algorithm is $O(|E|+|V|\log(|V|))$?
I really not understand why the running time is not the same in this case, any help? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5190281271934509, "perplexity": 208.93691502159214}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875145708.59/warc/CC-MAIN-20200222150029-20200222180029-00234.warc.gz"} |
https://www.physicsforums.com/threads/a-question-on-goldstein-and-dalemberts-principle.834084/ | # A Question on Goldstein and D'Alembert's Principle
1. Sep 23, 2015
### coca-cola
Hey all,
I am reading Goldstein and I am at a point where I can't follow along. He has started with D'Alembert's Principle and he is showing that Lagrange's equation can be derived from it. He states the chain rule for partial differentiation:
$$\frac{d\textbf{r}_i}{dt}=\sum_k \frac{\partial \mathbf{r}_i}{\partial q_k}\dot{q}_k+\frac{\partial \mathbf{r}_i}{\partial t}$$
Then he states, by the equation above, that:
$$\frac{d}{dt}\frac{d\mathbf{r}_i}{dq_j}=\sum_k \frac{\partial^2 \textbf{r}_i}{\partial q_j \partial q_k}\dot{q}_k+\frac{\partial^2 \mathbf{r}_i}{\partial q_j\partial t}$$
He further states from the first equation that:
$$\frac{\partial \mathbf{v}_i}{\partial \dot{q}_j}=\frac{\partial \mathbf{r}_i}{\partial q_j}$$
I have tried to connect the dots but I cannot succeed. Any insight is greatly appreciated. Thanks!
2. Sep 23, 2015
### lautaaf
Think the first relation as a definition for an operator
$$\frac{d}{dt}=\sum_k \frac{\partial}{\partial q_k}\dot{q}_k+\frac{\partial }{\partial t}$$
The second equation follows immdiately from applying $\frac{d}{dt}$ to $\frac{d\mathbf{r}_i}{dq_j}$ and the last one from applying $\frac{\partial}{\partial \dot q_j}$ to the first equation.
3. Sep 23, 2015
### coca-cola
Thanks!
So is the definition simply the chain rule of a function that depends on q_1, q_2,...q_N, and t? If the function had no explicit dependence on t, even though the generalized coordinates did, would you simply drop the partial with respect to t?
4. Sep 24, 2015
### lightarrow
Yes, certainly.
--
lightarrow
Similar Discussions: A Question on Goldstein and D'Alembert's Principle | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9566865563392639, "perplexity": 796.5259902296297}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084892059.90/warc/CC-MAIN-20180123171440-20180123191440-00241.warc.gz"} |
https://mathematica.stackexchange.com/questions/176420/regionintersection-of-regions | # RegionIntersection of Regions
This code does what I expected: It displays the region of intersection between two disks:
Region[
RegionIntersection[
Disk[{0, 0}, 1],
Disk[{3/2, 1/4}, 3/4]
]
]
I expected this to do the same, but it does not:
R1 = Region[Disk[{0, 0}, 1]];
R2 = Region[Disk[{3/2, 1/4}, 3/4]];
Region[
RegionIntersection[R1, R2]
]
It runs for a long time, and I've not had the patience to see if it ever displays the lune intersection.
Can anyone explain the difference?
Update. @HenrikSchumacher's comments showed that the problem is that there was a Region bug in version 11.1.1, which I was using, a bug fixed by version 11.3.
• No explanation here. It executes quickly and returns the same result exactly as the first example in my copy of version 11.3 for macOS. But Mathematica cuts off the two tips. I guess, Region is meant to represent exact regions while the visual return of a Region is a coarse discritization solely meant for a quick preview. Jul 1, 2018 at 16:58
• You can always convert to a MeshRegion or a BoundaryMeshRegion with customized resolution by DiscretizeRegion and BoundaryDiscretizeRegion. For example, the latter two have the option MaxCellMeasure that allows you to adjust how fine the discretization should be done. In total, all Region-related functionalities are rather new and a bit buggy; this is true in particular for BooleanRegion which is used under the hood (as you can see by inspecting FullForm[RegionIntersection[R1, R2]]). Jul 1, 2018 at 16:59
• @HenrikSchumacher: Perhaps the difference is that I am using 11.1.1.0 MacOS. Time to update! Jul 1, 2018 at 17:46
• @HenrikSchumacher: That was it---Works just as you describe in 11.3.0.0. Thanks! Jul 1, 2018 at 18:14
• Glad to hear that! You're welcome. Jul 1, 2018 at 18:51
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http://science.sciencemag.org/content/334/6062/news-summaries | # News this Week
Science 16 Dec 2011:
Vol. 334, Issue 6062, pp. 1478
1. # Around the World
1 - Washington, D.C.
FDA Decision on Emergency Contraceptive Overruled
2 - Brasília
Controversial Changes to Forest Law Pass Brazilian Senate
3 - Durban, South Africa
Climate Negotiators Agree to Pursue New Treaty
4 - Beijing
## Beijing
### Merck Commits $1.5 Billion to Build in Beijing Merck has made the largest single research investment by a giant pharmaceutical company in China to date. The New Jersey-based firm, known as MSD outside the United States, last week said it plans to spend$1.5 billion over the next 5 years on R&D, under the direction of a pioneer staff of 260 now in rented offices in Beijing.
Zhang Ming-Qiang, vice president and head of MSD R&D Asia, says Merck anticipates that China's pharma market—currently second in the world—will become the world's largest in 10 to 15 years. Two significant challenges lie ahead, according to Zhang. First, China has many talented young researchers, but is short on scientists experienced in drug R&D who can serve as mentors. Second, China's regulatory landscape is unclear, and companies often have trouble discerning a clear process to follow when they apply for new drug registration.
Merck previously established a commercial headquarters in Shanghai and manufacturing facilities in other parts of China. The first phase of construction is expected to be completed in 2014; it will house about “600 employees working in the areas of drug discovery, translational research, clinical development, regulatory affairs and external scientific research programs,” according to a company announcement.
## London
### Courtroom Neuroscience Not Ready for Prime Time
Using brain scanners to determine whether a witness is lying is premature and unrealistic, notes a 13 December report by the Royal Society. However, the report's authors say, brain scientists might eventually be able to help answer other legal questions, such as whether a violent offender is likely to strike again and at what age children's brains are developed sufficiently that they should be tried as adults; the report suggests that the United Kingdom's current cutoff, 10, is too low.
At best, functional magnetic resonance imaging might be able to detect deliberate lies, but not if a witness believed he was telling the truth, said experimental psychologist Nicholas Mackintosh of the University of Cambridge, who headed the Royal Society's working group on neuroscience and the law, at a press briefing 9 December.
Still, neuroscience can potentially provide “hard evidence” in other areas, Mackintosh said, such as identifying the presence of a gene that codes for monoamine oxidase, which is present in many violent criminals who were abused as children, and could signal an increased risk of recidivism. Researchers are also studying whether brain scans could one day be used to determine if a person is actually experiencing pain or is malingering to obtain government benefits. http://scim.ag/courtneuro
## Atacama Desert, Chile
### Big Step for Extremely Large Telescope
What will be the largest optical-infrared telescope ever built took a big step forward on 9 December. The European Southern Observatory (ESO) gave the green light to start bulldozing roads on the site of the European Extremely Large Telescope (E-ELT), to be erected at Cerro Armazones in northern Chile. Engineers will also begin developing the instrument's adaptive optics.
“The E-ELT is starting to become reality,” ESO Director General Tim de Zeeuw said in a statement. The move did not represent full approval for the €1.1 billion behemoth, however, because some of ESO's 15 member states have not yet secured needed funding.
Still, planners expect construction to begin in 2012 and observations to start in 2022. When finished, the E-ELT will have a main mirror 39.2 meters across, dwarfing today's largest telescope, the Large Binocular Telescope, which is equivalent to an 11.9-meter instrument. Meanwhile, two rival telescope efforts in the United States—the Giant Magellan Telescope and the Thirty Meter Telescope—are struggling to secure funding. http://scim.ag/E-ELT
2. # Random Sample
## Cannibalism on Ice
Inuit hunters in Greenland and Canada have long known that polar bears—usually adult males—might kill younger polar bears for food. But until this August 2008 photograph was taken, such events had been reported only on land, not on sea ice, and no one had photographed it before. In the December issue of Arctic, photographer Jenny Ross and arctic biologist Ian Stirling of Environment Canada in Edmonton note that there have now been three documented sightings of adult male polar bears on sea ice feeding on younger bear kills. They suggest that given the dwindling sea ice and the scarcity of seals nearby at that time of year, young polar bears may simply be the most available prey. But, they add, it might also be a sign of things to come: A warming climate and less and less sea ice will send seals northward even earlier in the summer, and the frequency of intraspecies predation could increase.
## Grand Canyon Too Crowded? Blame Climate Change
Climate change has altered the timing of plants blooming, insects hatching, and birds migrating—and it may be altering human vacation plans. A team analyzing attendance data at U.S. national parks from 1979 through 2008 found that of nine national parks showing increases in their average spring temperatures, seven also showed that peak tourist attendance occurred earlier in the season, by an average of 4 days. At Grand Canyon National Park, for example, peak attendance shifted from 4 July in 1979 to 24 June in 2008, the researchers report in an upcoming issue of International Journal of Biometeorology. Of 18 national parks that didn't experience climate change, only three showed shifts in peak attendance. Other major factors likely to influence park visitations—including population growth, economic trends, and travel costs—would tend to affect the total number of park visits but not their timing within the year, the researchers say.
## Tracking Contaminants in Whales—Using Their Earwax
Hold the giant Q-tip: The waxy buildup in a whale's ears may contain interesting data about its exposure to contaminants. A wall of blubber and muscle protects whales' ears from seawater, sealing the wax inside. The wax plugs are made up of laminated layers that can be matched roughly to a whale's age, like tree rings—and those layers can also be the repository of chemicals from the surrounding ocean.
Graduate student Eleanor Robinson, with environmental scientist Sascha Usenko and biologist Stephen Trumble, all at Baylor University in Texas, have worked out an analytical method to quantify the compounds sequestered in each wax layer. They use earplugs taken from dead whales (the earwax harvesting must be done posthumously, because marine mammals are protected by U.S. law).
Last month at the North American meeting of the Society of Environmental Toxicology and Chemistry in Boston, Robinson reported the team's first data, from an earwax plug from a whale that died in 1969 along the California coast; the plug ended up in the Smithsonian Institution's collection. The 6-centimeter-long earplug included a decade's worth of data and yielded small amounts of the pesticide chlordane, banned in the United States in 1988, as well as PCBs. The concentrations of chlordane decreased over the years, whereas the levels of PCBs remained relatively steady throughout the whale's life.
Unfortunately, the analytical method destroys the sample, Robinson says. And although the team may eventually be able to extrapolate earwax data to a whale's total “body burden” of chemical contaminants, determining when and where the animal picked those contaminants up, and whether they affected its health, will be an entirely different ball of wax.
## By the Numbers
655,000 — Estimated number of worldwide malaria deaths in 2010, a 5% reduction over 2009, according to the World Health Organization's World Malaria Report issued this week.
10% — The amount by which Cancer Research UK will cut its annual £330 million research budget over each of the next 3 years in response to declining donations.
$388,375 — Amount paid at an auction for the Apollo 13 checklist of commander James Lovell, which includes his handwritten calculations. It's the second most expensive space item on record, after a$2.9 million Vostok 3KA spacecraft sold last April.
3. # Newsmakers
## New Chief for HHS's Research Misconduct Office
David E. Wright, a science historian at Michigan State University (MSU) in East Lansing, will soon lead U.S. government efforts to guard against misdeeds in biomedical research. The Department of Health and Human Services (HHS) announced last week that Wright will become chief of its Office of Research Integrity (ORI) in January.
Wright, 66, now chairs MSU's department of community, agriculture, recreation, and resource studies. He served as MSU's research integrity officer from 1993–2004 and he has consulted for ORI since 2001. That led to his interest in leading ORI: “I have done it [research integrity] at the institutional level and consulted with the feds. I have a great deal of respect for the work [ORI] does,” Wright says.
ORI has lacked a permanent director since September 2009, when former director Chris Pascal retired after 13 years. http://scim.ag/HHSORI
4. Infectious Disease
# Taking a New Shot At a TB Vaccine
1. Kai Kupferschmidt*
Eager to replace the current tuberculosis vaccine, scientists hope to push a slew of promising candidates through clinical trials—if the money can be found.
When Barry Bloom, a veteran of tuberculosis research, wants to illustrate how far he and other scientists have gotten fighting the disease, the Harvard University immunologist shows a picture of a man holding a small saw in front of a huge redwood tree. The photograph usually gets a laugh out of the audience, but it illustrates a public health challenge that is far from funny: About one-third of the world's population is infected with the pathogen Mycobacterium tuberculosis. And although the bacterium is dormant in most of those people, they have a lifetime chance of 1 in 10 that the pathogen will wake up and cause tuberculosis.
Antibiotics can usually stop an active TB infection, but the needed drugs are too costly for many developing countries, and compliance is a problem because they need to be taken for months. The pathogen is also becoming increasingly antibiotic-resistant, requiring ever-more-expensive cocktails of drugs. And even though the World Health Organization reported this year that the number of TB cases is going down, the disease still kills 4000 people every day.
For many people around the globe, there's only one line of defense against the bacterium: a shot of a 90-year-old problematic vaccine that they get shortly after birth. That could soon change. “Ten years ago, not a single tuberculosis vaccine was in clinical development. Now there are a dozen,” says Stefan Kaufmann, an immunologist at the Max Planck Institute for Infection Biology in Berlin.
The emergence and rapid spread of multidrug-resistant strains of M. tuberculosis and the United Nations's declaration of halving TB deaths by 2015 as a Millennium Development Goal have led to an influx of private and public money, with product-development partnerships such as the Aeras Global TB Vaccine Foundation and independent nonprofit foundations such as the Europe-based Tuberculosis Vaccine Initiative (TBVI) leading the way. Now, after years of lab work and initial safety testing in humans, the most advanced of these candidates are entering their first human efficacy trials. “This is a real turning point,” says Jelle Thole, director of TBVI.
But with this new hope come challenges. Researchers are wrestling with how to select the best candidates to advance to much larger trials—and they are wondering how to pay for those final rounds of testing. Nor are there any guarantees of success at the end of this road. A human trial of one new tuberculosis vaccine was halted at the end of September because of apparent side effects.
## Out with the old, in with the new
The only currently available TB vaccine was developed between 1906 and 1919 by French scientists Albert Calmette and Camille Guérin. They cultured M. bovis, a relative of M. tuberculosis that mainly infects cows, for so long that it lost numerous genes and with them its virulence. The weakened, or attenuated, strain, dubbed Bacillus Calmette-Guérin (BCG), would become the world's most widely used vaccine. It has been given more than 4 billion times, and although there's no definitive evidence that it can actually prevent an initial infection, the vaccine can help the body limit the growth of the mycobacteria enough to protect many children from developing severe forms of tuberculosis. “It saves up to 60,000 lives every year,” says Willem Hanekom of the University of Cape Town in South Africa.
But a childhood BCG shot does not protect adults or adolescents against pulmonary tuberculosis, the most prevalent form of the disease nowadays. For unknown reasons, the vaccine also seems to work better for children in some places than in others.
More troubling, there is no evidence that the vaccine prevents tuberculosis in children already infected with HIV, and the vaccine itself is unsafe for many. An estimated 1% of these children cannot control the vaccine bacterium and develop disseminated BCG disease. Many of them die. “If it were proposed for use today, no one would allow such a vaccine to be used in an HIV-endemic country,” Bloom says. “But it does prevent meningitis and disseminated tuberculosis in healthy children, so no one wants to pull it out.”
To build a new vaccine that is at least safer, if not actually better at preventing disease, than BCG, researchers are pursuing numerous strategies: adding certain genes to BCG, taking specific genes out of natural, unattenuated mycobacteria, expressing M. tuberculosis genes in viruses, or combining proteins from the pathogen with new adjuvants. In general, the first generation of candidates can be divided into those intended to directly replace BCG as an infant vaccine or those intended as a booster of BCG. But researchers are also examining “vaccines” that could help people with dormant TB infections by stimulating the immune system to flush out mycobacteria.
The first replacement candidate to show substantially greater protection than BCG in various animal models was rBCG30, developed at the University of California, Los Angeles. The vaccine is a BCG strain overexpressing the M. tuberculosis protein Ag85A, believed to be important for stimulating a strong immune reaction to the bacterium. A phase I clinical trial, completed last year in the United States, suggested it was safe.
Another potential replacement is VPM1002, a new BCG strain developed at Kaufmann's lab. The scientists took BCG and added the gene for a protein called listeriolysin from the bacterium Listeria monocytogenes. Making this enzyme enables the proteins from the bacteria, which an infected cell normally traps inside a special compartment, to escape into the cytosol—boosting the vaccine's ability to rouse the immune system. In early animal tests, the new strain showed better protection than BCG. A phase II trial to establish safety and dosing in infants started 3 weeks ago.
A third replacement candidate, Aeras-422, employs a similar strategy, but it has run into trouble. The vaccine is a BCG strain genetically modified to overexpress three proteins and to make perfringolysin, an enzyme from yet another bacterium, so that it, like VPM1002, perforates the cell's encapsulating membrane and spills BCG proteins into the cytosol. But administration of this vaccine to people has recently been halted because of safety concerns that arose in a phase I trial in the United States: Two vaccinated people developed shingles, a painful skin rash caused by reactivation of a dormant virus.
Many scientists see perfringolysin as the most likely culprit, but Aeras is still investigating. “There is no obvious explanation at the moment,” Kaufmann says. “We hope that Aeras will follow this up to see whether there is a more general mechanism at work.” But there are no data to indicate that VPM1002 has similar problems. Unlike perfringolysin, listeriolysin is rapidly degraded in the cell and is not cytotoxic. “The safety of VPM1002 has already been assessed in clinical trials in Germany and South Africa without any problems,” Kaufmann says.
Some of the proposed booster vaccines are a combination of specific M. tuberculosis proteins, which on their own don't generate disease symptoms, and adjuvants. The two booster candidates that have advanced furthest use a different strategy: equipping harmless viruses with genes for mycobacterial proteins so that they can infect cells and produce the proteins, stimulating an immune response against the pathogen. Crucell Ad35/Aeras-402, for example, is an adenovirus producing three proteins naturally made by the TB bacterium: Ag85A, Ag85B, and TB10.4, a protein that is not present in BCG. The vaccine is currently being tested for efficacy in clinical trials in HIV-positive adults and infants. And MVA85A, developed at the University of Oxford, is a modified vaccinia virus that has been engineered to express Ag85A. It is currently being test ed in two phase IIb proof-of-concept trials in South Africa and Senegal in 2784 infants and in 1400 HIV-infected adults.
Initial data from the infant MVA85A trial are expected next year. This will be the first time efficacy data on one of the new vaccine candidates become available—and a pivotal moment, Kaufmann says: “If the first efficacy data is positive, it will push the whole field ahead, but if it is negative, it could make funding our efforts even more difficult.”
The MVA85A study is designed to detect whether the vaccine boosts BCG's normal protection rate by 60%. If that goal is achieved, the next step would be a phase III trial, the last step before a vaccine could be put on the market. And that is where money becomes a major issue.
## Whittling down the field
Results from the phase II trials of various other vaccine candidates will begin to trickle out later next year, potentially forcing hard decisions. A lot of money has been poured into tuberculosis research recently from sources such as the U.S. National Institutes of Health, the European Commission, the Bill & Melinda Gates Foundation, and the Wellcome Trust. Kaufmann estimates that about half a billion dollars is available every year for tuberculosis research, about a fourth of which goes into vaccine research and development.
But vaccine developers fear that there won't be enough to launch the critical, large phase III clinical trials, especially if multiple candidates need to be evaluated. Whereas a phase I vaccine trial costs between $1 million and$5 million, and a phase II trial, between $5 million and$20 million, up to $200 million is needed for a phase III trial. “The field needs more money,” says Kaufmann, who estimates that$1 billion a year is needed for the next 10 years to fund TB vaccine research and development.
TBVI is among those trying to raise that money. At a recent meeting in Madrid, its officials unveiled an ambitious plan to finance numerous vaccine trials, including two phase III trials, with the aim of having two TB vaccines on the market in 2020. TBVI's Thole estimates that the organization would need $750 million over the next 10 years to pull that off. The initiative is seeking money from the European Investment Bank, with European governments supporting the “loans” with guarantees. “That money is an investment that will be paid back by revenue from the royalties paid on the two successful vaccines,” says Thole, who contends that several governments have already shown interest in the plan. Aeras, a U.S.-based nonprofit organization that was founded in 2003 to develop a TB vaccine, is taking a slightly different route: “We think commercial partners are crucial,” says Thomas Evans, chief scientific officer of Aeras. Any phase III vaccine trial of its candidates would likely be funded by a consortium that included the pharmaceutical industry, he notes. “What TBVI is doing is very innovative, and we are supportive of them going ahead with this because more money is badly needed,” Evans says. “But they will have to deal with the issue of getting the pharmaceutical industry on board while also needing to recoup the money.” Everybody in the field agrees that there won't be enough money for all of the vaccine candidates to move into phase III trials. Aeras alone is supporting six TB candidates in phase I or II clinical trials. And there are another six vaccines backed by other sponsors and many more pushing into clinical trials. So the big issue now is to identify those vaccines that are most likely to succeed. “It is ironic,” Kaufmann says. “We used to have no candidates; now we have too many.” To address that problem, scientists from Aeras and TBVI are working to establish clear criteria for choosing the most promising candidates that should advance to the next stage of clinical testing. Their blueprint is due out next spring. Overall, there's a lack of tools to evaluate potential tuberculosis vaccines in both animal studies and human trials. It is unclear, for example, how well the animal models predict the effectiveness of a vaccine in people. “We are looking for a vaccine that works where BCG does not, but our animal models are designed to show where BCG works,” Ann Rawkins, an expert on animal models of tuberculosis at the Health Protection Agency in Porton Down, U.K., said at the conference in Madrid. For those candidates ready for advanced clinical trials, other questions loom large. What populations should be tested, for example? At the moment, phase I and II TB vaccine trials are performed mostly in infants and HIV-positive adults. Because these groups develop tuberculosis more often, fewer subjects are needed to see a significant effect of the vaccine. “But even in areas with high prevalence of HIV, it is the HIV-negative adults who are most likely to transmit TB,” says Hanekom, who contends that these people should be the first to be studied in clinical trials. “Otherwise, there is a possibility that a negative trial in HIV-positive adults may compromise development of a candidate that might work in HIV-uninfected persons.” To help evaluate all the TB vaccine candidates, some researchers have begun grappling with the idea of so-called challenge trials. For malaria and cholera, scientists have the option of deliberately infecting volunteers with the relevant pathogen to see whether a vaccine works, because both diseases can be readily treated. These challenge trials can save a lot of time and money, but researchers agree that directly infecting humans with the TB bacterium would be unethical because treatment currently requires a 6-month regimen with three or four antibiotics, and there is a risk of not eradicating the pathogen entirely. Yet Helen McShane has proposed challenge trials in which people would receive a candidate TB vaccine before being injected with BCG, the current vaccine but also a live, replicating mycobacterium. She argues that if the candidate, for example, helps the body more quickly eliminate BCG, it should also protect against TB. But others are skeptical. “We would only find out whether we are protecting against the current TB vaccine and not against the real pathogen,” Kaufmann says. “We are in the very early days, but a challenge model would be game-changing in some ways, so we need to find out whether it is possible to get a challenge model,” Evans says. ## Looking ahead Even if scientists surmount all these difficulties and deliver a new vaccine by 2020, the fight against tuberculosis would be far from over. “This is just the first generation of candidates, and they are all far from perfect,” Kaufmann says. They are, with respect to Bloom's redwood picture, just a slightly bigger saw. A different tool that may one day be wielded is a tuberculosis vaccine designed to eliminate or better control dormant infections; even the current, rigorous antibiotic regimen often leaves some mycobacteria untouched. Just 2 weeks ago, Aeras announced the first phase I clinical trial of a vaccine, SSI H56-IC31, specifically intended to target those dormant bacteria. Developed at the Statens Serum Institut in Copenhagen, the vaccine consists of an adjuvant and recombinant versions of proteins known to be made more often by dormant forms of the TB bacterium. All these candidate vaccines have scientists reconsidering whether it's realistic to develop an ultimate vaccine that truly stops M. tuberculosis from ever initially establishing an infection in a person. At first, Evans says, “the feeling was that bar is too high; let us try to prevent disease first. But we need to start looking at vaccine candidates now that could prevent infection.” That could be the tool that finally fells Bloom's colossal tree. • * Kai Kupferschmidt is a science writer in Berlin. 5. Traditional Medicine # Piercing the Veil of Ayurveda 1. Pallava Bagla Enthusiasts hope that clinical trials of Ayurvedic medicines will buff the ancient art's tarnished reputation. BANGALORE, INDIA—At a gleaming new facility here in India's biomedical research hub, chemists and Ayurvedic practitioners are teaming up to breathe new life—and instill scientific rigor—into an ancient art of healing. At the$10 million Institute of Ayurveda and Integrative Medicine (IAIM), several dozen researchers scour ancient manuscripts for therapeutic recipes, cultivate rare medicinal plants, and attempt to isolate active compounds. Meanwhile, healers use modern diagnostics to refine treatments at IAIM's 100-bed hospital.
The new institute is part of a concerted effort to buff Ayurveda's reputation. Last May, the European Union, concerned about mercury and other heavy metals in preparations, banned the sale of nonauthorized Ayurvedic products. Since then, no preparations have passed muster. Even in India, where Ayurvedic medicine has been practiced for 3500 years, “today most people turn to Ayurveda literally as a last resort,” says Vaidya Balendu Prakash, director of the VCPC Research Foundation, an Ayurvedic treatment center in Dehradun.
Hoping to turn the tide, India's Council for Scientific and Industrial Research (CSIR) in New Delhi has embarked on a $25 million initiative to modernize a discipline practiced by 500,000 registered healers in India alone. The initiative will subject concoctions—from benign herbs to bona fide poisons—to modern analysis. Proponents face an uphill struggle. “Ayurveda has been demonized by modern science,” says Rajiv Kumar, a chemist at Tata Chemicals Innovation Centre in Pune. Kumar lays the blame on healers, who he says are “closed and secretive about what and how they practice.” Healers say that secrecy is necessary to protect intellectual property. They aim to balance three “energies” that roughly correlate to vata, or wind; pitta, or bile; and kapha, or phlegm. According to ancient texts, all doshas, or ailments, arise when the energies are off kilter. Putting Ayurvedic medicine on a firmer scientific footing won't be easy, as Prakash attests. A second-generation healer, he is promoting a silver- and mercury-based treatment called “Navjeevan” that he has refined for acute promyelocytic leukemia. At the U.S. National Institutes of Health in Bethesda, Maryland, in June 2010, Prakash presented positive results from his Dehradun lab and from others on Ayurvedic anticancer treatments. But he acknowledges that some data were ambiguous; few in the audience were swayed. To tamp down toxicity concerns, Prakash invited Kumar to vet Navjeevan in 2005. Kumar was astonished. “It's scary to see how callously mercury is handled by the pharmacists” in the preparation of some medicines, he says. But to his surprise, Kumar found that Navjeevan's months-long preparation had converted liquid mercury to a complex or polysulfide form of mercury, blunting its toxicity, he says. The faith that healers place in poisons has tended to undermine Ayurveda's reputation. The field took a hit in August 2008, when Robert Saper of Boston Medical Center and colleagues reported that one-fifth of 193 Ayurvedic medicines they tested after purchase over the Internet contained detectable levels of lead, mercury, or arsenic. Writing in The Journal of the American Medical Association, the researchers called for “strictly enforced, government-mandated daily dose limits for toxic metals in all dietary supplements.” “This led to a severe backlash and growing distrust in Ayurveda,” says IAIM founder Darshan Shankar. Some experts are dubious that Ayurveda can navigate the path to respectability offered by standard clinical trials. “The use of controls and placebos, so central to clinical trials, sits ill with Ayurveda,” says Marthanda Varma Sankaran Valiathan, a cardiac surgeon and former vice chancellor of Manipal University. Ayurveda, he explains, “regards every individual as unique and the package of therapeutic measures, including virtuous conduct, lifestyle, diet, and drugs, as inseparable.” Others argue that Ayurveda's relevance will fade if concoctions don't pass standard tests. One formulation used to treat rheumatoid arthritis did well in a double-blind, randomized match-up against a Western drug. In the first trial of this kind involving a total of 43 patients, people were assigned the unnamed Ayurvedic preparation, the Western drug methotrexate, both, or a placebo. “All three treatments were equivalent in efficacy, but adverse events were fewer in patients treated with the Ayurvedic medicine,” a team led by Daniel Furst of the University of California, Los Angeles, reported in the June issue of the Journal of Clinical Rheumatology. “This marriage of a traditional medicine system with modern inquiry augurs well and is probably the best way forward,” says microbiologist Padma Venkat, IAIM director. Ayurveda may soon make its debut in Western apothecaries. A herbal preparation mentioned in Ayurvedic texts and extracted from the weedy Mexican poppy (Argemone mexicana) led to the discovery of a possible treatment for psoriasis, a skin disorder that afflicts 2% of people around the world. Desoris, developed by Lupin Laboratories in Mumbai, is now in clinical trials. And last year, following leads from Ayurveda, CSIR researchers discovered what they claim is a memory-enhancing compound derived from brahmi (Bacopa monnieri), a marsh plant in northern India. To Venkat, the findings herald the emergence of a new discipline: Ayur-biology. But restoring the ancient art's reputation, she acknowledges, will not happen overnight. 6. U.S. Science Policy # Suresh Expects Low-Cost Ideas Will Mean a Big Payoff for NSF 1. Jeffrey Mervis The director of the National Science Foundation has hit the ground running with a flurry of new programs aimed at leveraging precious federal dollars. One year into his 6-year term as director of the National Science Foundation (NSF), Subra Suresh is pushing the 60-year-old basic research agency in new directions. The most visible evidence is a quartet of new initiatives intended to promote entrepreneurship, accelerate the review process, foster international collaborations, and improve conditions for women. The soft-spoken former Massachusetts Institute of Technology dean of engineering says he's simply trying to get more out of NSF's$6.8 billion budget. But his modesty hides a keen political sensibility.
It's no accident that each of the initiatives meshes with one of the Obama Administration's priorities for bolstering U.S. science, and none requires a big investment. That latter feature is especially pleasing to congressional appropriators as they struggle to keep agencies healthy while trimming overall federal spending. In fact, NSF's reputation for sound fiscal stewardship helped it obtain a 2.5% budget increase in 2012, a rare boost in the current era of austerity (Science, 25 November, p. 1041).
The new Innovation Corps (I-Corps) program, for example, reflects that combination of frugality and fresh thinking. The frist round awarded $50,000 to 21 scientists to test the waters for a product based on their NSF-funded research. The new wrinkle is that the scientists are teamed with an experienced entrepreneur and a graduate student, and each trio gets a 3-month crash course to square their idea with what potential customers want before seeking funding from venture capitalists or a government-funded program for start-ups. “I picked it because we could do it without a lot of extra dollars,” Suresh says. “And I knew that the issue resonated with Congress and the Administration, and with industry and the community.” A second initiative, Science Across Virtual Institutes (SAVI), leverages something NSF is already doing—helping U.S. scientists collaborate with their peers abroad—by attracting even larger investments from other countries. By requiring buy-in from not only the discipline-based program but also NSF's international office, SAVI also advances Suresh's goal of One NSF, a management concept aimed at breaking down some of the walls between NSF's seven discipline-based directorates and two offices. It's not that Suresh doesn't think about money. He faces the chronic problem of balancing support for individual researchers against the need for expensive new facilities used by an entire discipline. NSF's decision to pull out of the proposed Deep Underground Science and Engineering Laboratory in South Dakota (Science, 17 December 2010, p. 1596) will relieve some of the immediate budget pressure, but the community's ravenous appetite for new infrastructure will test Suresh's management skills. Suresh is also looking inward. One major effort involves fine-tuning NSF's vaunted merit-review system; the challenge will be to prevent success rates on applications from dipping too low in an era of flat or declining budgets. This week, NSF's oversight body, the National Science Board (NSB), may adopt a new definition of its controversial second criterion for assessing grant proposals, relating to the broader impacts of the research apart from its scientific merit (Science, 14 October, p. 169). An internal working group is also reviewing every aspect of NSF merit review. The timing is not coincidental: In May, Suresh will chair an international summit on merit review hosted by the U.S. government. A global perspective comes easily to the Indian-born Suresh. But as a naturalized U.S. citizen, he's thoroughly American when he comes to assessing the likelihood of China surpassing the United States in his lifetime (he's 55). “Well, it's clear that they are increasing their investment in infrastructure,” he says. “But I also believe in the nimbleness and resilience of the American enterprise. So I'm not willing to concede that we will lose our scientific preeminence and become number 2 or number 3 [in the world]. The competition has never been as severe as we face now. But it may still not be too late to stay on top.” On 7 December, Science sat down with Suresh in his Arlington, Virginia, office to talk about these and other issues. Here are excerpts from that interview. Q:Why did you launch the Innovation Corps initiative? S.S.:Our mission is basic research, and that's not going to change. But how do we take that basic research output and get the biggest bang for the buck without diverting precious basic research dollars? There are many models for that. I-Corps tries to make use of NSF's reach, scope, and statute, and also bring in private partnerships. … The idea is to do something new, leverage something significant, and also improve our internal processes. If we want to give an award for 6 months, it doesn't make any sense to have a review process that takes 9 months. So we wanted to accelerate that review process. And that's exactly what we did in the first round of awards. We made them 4 weeks after the solicitation. Q:What do you hope SAVI will accomplish? S.S.:SAVI has a couple of objectives. In the spirit of One NSF, how do we make sure that people can work better together? For example, in mathematics we have an NSF-funded center at Brown University and three institutions in North Carolina, and we got them together and collectively they began to think of international partners. But here's the thing. A program director can do some things, but if NSF as a whole does something, our leveraging power is significantly higher. So we set up a common policy for all SAVI activities. It has to be supported by the program and division director and have the endorsement of the assistant director and the international office. And that's not just, “Yes, it's a good idea. Go do it.” It also has to come with dollars. And that's a real endorsement. Brown and the North Carolina institutions decided they wanted to work with a group of Indian institutions. So NSF put up$6 million, and the Indian government put up \$20 million. That's real leverage. Now we deal directly with the secretary for science and technology for India, and that gives us tremendous leveraging power.
Q:How do you feel when elected officials and candidates deny the scientific evidence for climate change caused by increasing CO2 levels from human activity?
S.S.:Well, my reaction is, there should be room for different interpretations and disagreements. But facts are facts. NSF doesn't do any internal research. We support research through a transparent and open process. Let the scientists publish and let people interpret, some one way and some another way. And my belief is that, in the end, whatever is the truth will prevail.
Q:NSF managed to boost success rates by using most of its stimulus money to fund proposals already in the pipeline. Can you sustain current success rates with the 2012 budget?
S.S.:The success rate depends on a lot of factors. It's not just the number of proposals and the dollars available. It also depends on how we process the proposals, including how many times the same idea gets resubmitted. If an idea has no chance of getting through the process, does it make sense to have it be reviewed over and over again?
Within NSF, the success rates for particular programs vary by a factor of 4. So another question is whether we are setting up the right expectations for the community. … It's also field-specific. There may not be one magic solution for all of NSF.
Q:Some people have suggested that NSF should require universities to show evidence of their success in broadening participation—one of the criteria under the “broader impacts” of a research activity—as a condition for continued funding. Is that an appropriate role for NSF?
S.S.:One thing the NSB task force on broader impacts has looked at closely is metrics for success. And these are inherently long term. The time frame in which you assess the impact is much longer than the duration of the grant itself. That makes it much harder to say, at the end of 3 years, whether you've had an impact or not. So one thing we've been grappling with is how to put quantifiable, verifiable, and accessible metrics into everything we do, including broader impacts.
Q:Is having a separate account still the best way to fund new large facilities?
S.S.:We now have an MREFC account. If all the costs come out of [research], it will be a completely different discussion. So one of the in-between things we are trying to do is to look at a longer time horizon. We also are looking at different [budget] scenarios. One is reasonably optimistic, one is flat, and one is highly pessimistic. And then we're asking the question: What is the minimum level at which we can do [a particular project]? And is that good enough? Is it worth it? And if the answer is no, then it falls off the list. …
We're looking at a number of criteria. What's the overall value of the science? How large is the community that will be impacted? How much money has already been spent? It's project-based, and it's not just 1 year. If we fund fewer projects this year and do more next year, it may seem like a convenient solution to an immediate budget crunch. But you may end up wasting money in the long run because costs will go up. …
The flexibility that Congress has given us [to shift money from other NSF accounts] is good. But it also eats into basic research. It's a fine line to walk. If you have a separate account for facilities, as we do now, then sometimes you don't realize the cost impact. In a zero-sum game, it's not coming out of someone else's pocket. It's coming out of our pocket.
Q:Why did NSF pull out of the proposed Deep Underground Science and Engineering Laboratory?
S.S.:NSF is always interested in funding the best science. But the question is, “Can we afford it in the current climate?” The science board also wondered if NSF has the capacity to run a major facility like this. NSF doesn't run national labs. We're still interested in supporting the basic science. But maybe we'll be able to partner with other federal agencies.
Q:Did Congress make a mistake by prohibiting NASA and OSTP from scientific collaborations with China?
S.S.:[Congress] didn't say anything about NSF. … [Presidential science adviser] John [Holdren] can speak for OSTP. None of the things we do are proprietary or classified. We are a basic science agency, and we are in a different place than other mission agencies.… So far, we have not seen any impact from the congressional language. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.16077665984630585, "perplexity": 4042.0004007063844}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187822488.34/warc/CC-MAIN-20171017200905-20171017220905-00315.warc.gz"} |
https://docs.scipy.org/doc/scipy-1.5.3/reference/generated/scipy.special.pro_rad2.html | scipy.special.pro_rad2(m, n, c, x) = <ufunc 'pro_rad2'>
Prolate spheroidal radial function of the second kind and its derivative
Computes the prolate spheroidal radial function of the second kind and its derivative (with respect to x) for mode parameters m>=0 and n>=m, spheroidal parameter c and |x| < 1.0.
Returns
s
Value of the function
sp
Value of the derivative vs x | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6885190606117249, "perplexity": 2473.1333489384388}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243991557.62/warc/CC-MAIN-20210517023244-20210517053244-00247.warc.gz"} |
https://www.oreilly.com/radar/the-game-of-business-its-time-to-rewrite-the-rules/ | # The game of business: It’s time to rewrite the rules
Our current economic rules encourage the allocation of gains to consumers and financial shareholders, and the losses to workers and taxpayers. It doesn’t have to be that way.
August 4, 2016
Photograph of mural "Sorting the Mail" by Reginald Marsh at the Ariel Rios Federal Building, Washington, D.C.
Modern economics likes to think of itself as a science, and too often, its practitioners have attempted to uncover its “laws,” as if they were modern Isaac Newtons uncovering the laws of motion. But many of the laws of economics are far more like the rules of a game than like the laws of nature. Some of the rules represent what appear to be fundamental constraints—the availability of resources, say, or the absorptive capacity of the environment, or even the behavioral patterns of human nature—while others are arbitrary and subject to change, such as tax policy, government entitlements, and minimum wage requirements.
An economy has untold possible outcomes. Its complexity comes both from the near infinite variety that can come from permutations of simple rules, and from the fact that billions of humans are playing the game simultaneously, each affecting the outcomes for each other. Many of the rules are written down nowhere, controlled by no one, and constantly evolving. Individuals, businesses, and governments are all players, and none of them can know the full consequences of their decisions.
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Even the simplest and most definitive of the “rules” of an economy are far more complex to apply than they appear on paper. As an Internet wag noted many years ago, “The difference between theory and practice is always greater in practice than it is in theory.” This difference between theory and practice is driven by complex interactions, not only between rules but between multiple players with competing incentives.
This complexity came to mind last year in a conversation I had with Uber’s economists. I was arguing that just as Google’s search algorithm takes many factors into account in producing the “best” results, Uber’s algorithm would benefit if it took drivers’ wages, job satisfaction, and turnover into account, and not just passenger pickup time, which is its current fitness function. (Uber aims to have enough drivers on the road in a given location that the average pickup time is no more than three minutes.)
The economists explained to me that Uber’s wages were, by definition, optimal, because they simply represent a demand curve, one of the most basic laws of economics.
Uber’s real-time matching algorithm satisfies two overlapping demand curves. If there are not enough passengers, the price must go down to stimulate passenger demand. That’s the essence of Uber’s frequent price cuts. But if there are not enough drivers to satisfy that demand, the price has to go up to encourage more drivers to come on the road. That’s the essence of surge pricing.
Uber’s argument is that the algorithmically determined cost of a ride is at the sweet spot that will drive the most passenger demand while also providing sufficient incentive to produce the number of drivers to meet that demand. And because driver income is the product of both the number of trips and the rate paid, that sweet spot will also maximize driver income. Any attempt to set rates to specifically raise driver income would suppress rider demand, and so reduce utilization, and thus wages. Of course, if too many drivers show up, this will also reduce utilization, but the economists seem confident, based on data that they were not authorized to share with me, that they have generally found that sweet spot.
If Uber had the courage of its convictions, it would be doing completely algorithmic pricing (including surging prices in a negative direction, below the base price), much as Google sets ad prices with an auction. Why don’t they? Because they believe that customers are more comfortable with a known base price. That is, the difference between theory and practice is greater in practice than it is in theory.
I do believe that labor marketplace algorithms can be game changers for business and society if they are used to model and satisfy more and more complex conditions. There’s no question that even in their current state, Uber’s real-time marketplace algorithms allow for far better matching of supply and demand than the previous structure of the taxicab and limousine industry. But Uber can do better. Algorithms such as these can be a real advance in the structure of our economy, but only if they take into account the needs of workers as well as those of consumers, businesses, and investors.
Here’s the rub in the real world: Uber isn’t just satisfying the two simultaneous demand curves of customer and driver needs, but also competitive business needs. Their desire to crush the incumbent taxi industry and to compete with rivals like Lyft in the U.S. market and Didi in China also affects their pricing. Under the rules of the venture-backed startup game, they must grow at a rate that will allow them to utterly dominate the new industry that they have created in order to satisfy the enormous valuation placed on them by their investors.
Drivers are also not playing a simple game in which they can just go home if the wages aren’t sufficient. They have bills to pay, and may have to work far more hours than they would like in order to meet them. They may know in theory that they are depreciating the value of their vehicle and running up expenses that undermine their hourly earnings, but they don’t feel they have any choice. Alternative jobs may be even worse, with less flexibility and even lower pay.
I suspect that over time, driver wages will need to increase at some rate that is independent of the simple supply and demand curves that characterize Uber’s algorithm today. Even if there are enough drivers, the quality of drivers deeply influences the customer experience.
Driver turnover is a key metric. As long as there are a lot of people willing to try working for the service, it is possible to treat drivers as a disposable commodity. But this is short-term thinking. What you want are drivers who love the job and are good at it, are paid well, and as a result, keep at it. Over the long term, I predict that Uber and Lyft will be engaged in as fierce a contest to attract and keep drivers as they are to attract and keep customers today. And that competition may well provide further evidence that higher wages can pay for themselves by inducing productivity and greater consumer satisfaction.
Many simplistic apologists for the capitalist system celebrate disruption and assume that while messy, it will all work out for the best if we just let “the invisible hand” do its work. This is true, if we correctly understand the invisible hand. The law of supply and demand is not describing some invisible force, but the way that players of the game fight for competitive advantage. There are games within games. As Adam Smith put it:
It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity but to their self-love, and never talk to them of our own necessities but of their advantages.
The “law” emerges from the contest between players. As labor organizer David Rolf said to me, “God did not make being an auto worker a good job!” Those middle class jobs that we look back at with such nostalgia were the result of a fierce competition between companies and labor as to who would set the rules of the game. The invisible hand became very visible indeed by way of bitter strikes, and then transcended the market into the political process with the National Labor Relations Act of 1935 (the Wagner Act), the Labor Management Relations Act of 1947 (Taft-Hartley), and state “right to work laws.” Over the past 80 years, these acts have tilted the rules first one way, then the other.
Right now, we’re at an inflection point, where many rules are being profoundly rewritten. Much as happened during the industrial revolution, new technology is obsoleting whole classes of employment while making untold new wonders possible. It is making some people very rich, and others much poorer. It is giving companies new ways to organize; those new forms of organization are gradually being matched by labor.
I am confident that the invisible hand will do its work. But not without a lot of struggle. The political convulsions we’ve seen in the U.K. and now in the U.S. are a testament to the difficulties we face if we let the invisible hand struggle through normal channels! We are heading into a very risky time.
These discussions are more than theoretical. Rising global inequality is triggering a political backlash that could lead to profound destabilization of both society and the economy. Alas, as my friend Bill Janeway wrote to me in an email, “The supposed laws of welfare economics assert that the optimal distribution of wealth is achieved when (1) no one can be made better off if done so by making someone worse off and (2) the winners compensate the losers. It is also rarely that such compensation is rendered ‘from the benevolence’ of the winners! Unfortunately, the winners rarely do, except as the result of political coercion.” That political coercion may be at hand.
Many discussions of our technological future assume that the fruits of productivity will be distributed to the benefit of all. And that is clearly not the case. Right now, the economic game is enormously fun for far too few players, and an increasingly miserable experience for many others.
“Between the end of World War II and 1968, the minimum wage tracked average productivity growth fairly closely,” wrote economist John Schmitt. “Since 1968, however, productivity growth has far outpaced the minimum wage. If the minimum wage had continued to move with average productivity after 1968, it would have reached $21.72 per hour in 2012—a rate well above the average production worker wage. If minimum-wage workers received only half of the productivity gains over the period, the federal minimum would be$15.34.”
Meanwhile, the vast bulk of the value created by increasing productivity has been allocated to corporate profits. Contrary to what you might expect, this is not because companies need those higher profits to grow and sustain themselves, investing in new products and hiring more people in the process. It is because of the unintended consequences of rules designed to align the interests of management and shareholders that instead made management prioritize growth of the stock price above all other considerations. As Rana Foroohar, author of the book Makers and Takers and one of the speakers at this year’s Next:Economy Summit, put it in a recent Time magazine cover story, “the single biggest unexplored reason for long-term slower growth is that the financial system has stopped serving the real economy and now serves mainly itself.”
Another huge swath of value has been allocated to consumer surplus—the difference between what goods sell for and what customers might have been willing to pay. (A huge amount of the value that new technology brings has been provided to consumers free of charge, creating consumer surplus that is difficult to measure.) Free trade and depressed wages have also led to fierce competition by companies to expand their market share by offering goods at lower prices (much as Uber has done with taxi fares.) This is also a powerful kind of consumer surplus, and one of many strategies that economic game players employ to gain advantage.
I like to use Walmart as an example of the complexity of the game play and the tradeoffs that players ask us to make as a society. Walmart has built an enormously productive business that has vastly reduced the cost of the goods that it supplies. A large part of the value goes to consumers in the form of lower prices. Another large part goes to corporate profits, which benefits both company management and outside shareholders. But meanwhile, Walmart workers are paid so little that most need government assistance to live—by coincidence, the difference between Walmart wages and a $15 minimum wage for their U.S. workers (approximately$5 billion/year) is not that far off from the $6 billion/year that Walmart workers are subsidized via Federal supplemental nutrition assistance (SNAP, formerly known as “food stamps”). You can see here that there is a five-player game in which gains (or losses) can be allocated in different proportion to consumers, the company itself, financial markets, workers, or taxpayers. The current rules of our economy have encouraged the allocation of gains to consumers and financial shareholders (now including top company management), and the losses to workers and taxpayers. But it doesn’t have to be that way. We can wait for the invisible hand (i.e., the push and pull of the many players in the game) to work things out, or we can try out different strategies for getting to optimal outcomes more quickly. We can rewrite the rules. In professional sports, leagues concerned about competitive play often establish new rules. Football (soccer) has changed its rules many times over the past 150 years. NBA basketball added the 3-point shot in 1979 to make the game more dynamic; rule changes are being proposed again after the game-changing play of Golden State Warriors star Stephen Curry. Many sports use salary caps to keep teams in large markets from buying up the best talent and making it impossible for smaller markets to compete. And so on. The “fight for 15,” the movement toward a national$15 minimum wage, is one way to rewrite the rules. Businesses and free market fundamentalists argue that raising minimum wages will simply cause businesses to eliminate jobs, making workers even worse off. The evidence shows that this isn’t the case. As Nick Hanauer said during the Q&A at last year’s Next:Economy Summit, “That’s an intimidation tactic masquerading as an economic theory.”
The key question, expressed in the true language of Adam Smith’s “invisible hand,” is who gets more, and who gets less. Capital, labor, consumers, taxpayers.
As noted above, a $15 minimum wage might cost Walmart on the order of$5 billion/year. This is no small number. It represents about a quarter of Walmart’s annual profits, and about 1.25% of its annual U.S. revenues. But it might save taxpayers $6 billion per year (and that’s just the amount used to subsidize Walmart; including all the other low-wage employers in America, the number is far larger.) If Walmart weren’t able to pass off part of its true costs onto taxpayers, the company would have to cut its profits or raise its prices. But is that really such a bad thing? Let’s do some back-of-the-napkin math. If Walmart were to reduce its profits by$5 billion (approximately 20%), its market cap might fall, a loss to shareholders. But leaving aside the shock of a sudden drop in earnings due to a change in the rules, would the owners of Walmart really not have wanted to own it if it generated $20 billion a year in profit instead of$25 billion?
If Walmart were to pass along the additional costs to consumers, prices would have to go up by 1.25% (or $1.25 for every$100 spent at Walmart). If the costs were split between capital and consumers, that would require only a 10% drop in Walmart profits and an additional 62 cents per \$100 spent by consumers. Would people really stop shopping at Walmart if they had to spend little more than an additional half cent for every dollar?
Those higher prices might discourage some customers, but the higher incomes of workers might encourage them to spend more. So, it’s not inconceivable that Walmart and its shareholders would come out whole.
And of course, raising the minimum wage is only one way to address the way that the current rules of our economy favor owners of capital over human workers. Tax rates really do need some rethinking! Why do we have preferential rates for taxes on capital when it is so abundant that much of it is sitting on the sidelines rather than at work in our economy? Why do we tax labor income when one of the problems in our economy is lack of aggregate demand due to insufficient consumer spending?
We could change these relative tax rates, and even institute a “Wealth tax” such as proposed by Thomas Piketty and use the proceeds to help fund a Universal Basic Income! In fact, why not tax carbon rather than labor, substituting a carbon tax for social security taxes, among the most regressive of all taxes imposed? These rule changes might be even more costly to capital owners but might well benefit society overall.
These are political decisions as much as they are purely economic or business decisions. And that is appropriate. Economic policy shapes the future not just for one person or one company, but for all of us.
Throughout history and across continents, economies have played the game using different rules: all land belongs to kings and aristocrats. No one can own the land. All property should be held in common. Property should be private. Property is entailed and cannot be sold by the owners or heirs. Labor belongs to kings and aristocrats and must be supplied on demand. A man’s labor is his own. Women belong to men. Women are independent economic actors. Children are a great source of cheap labor. Child labor is a violation of human rights. Humans can be the property of other humans. No human can be enslaved by another.
We look back at some of these rules as barbaric, and others as utopian dreams. But we also can see that some rules have led to golden periods when society flourished.
Here is one of the failed rules of today’s economy: humans are expendable. Their labor should be eliminated as a cost whenever possible. This will increase the profits of a business, and richly reward investors. These profits will trickle down to the rest of society.
The evidence is in. This rule doesn’t work.
It’s time to rewrite the rules. We need to play the game of business as if people matter.
Post topics: Next Economy
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https://www.physicsforums.com/threads/rectilinear-motion-of-particle.288126/ | # Rectilinear Motion of Particle
1. Jan 28, 2009
1. The problem statement, all variables and given/known data
3. The acceleration of a particle is directly proportional to the time t. At t=0, the velocity of a particle = -12 m/s. Knowing that v=0 and x = 15 when t=4s, write the equation of the motion.
Here is my solution, could Somebody check it?
Text is in Polish, sorry for that
2. Jan 28, 2009
### turin
I'm still waiting for the attachment approval. In the meantime, dzien dobry.
3. Jan 29, 2009
Dzien dobry Attachment approval? So you cannot look into it?
4. Jan 29, 2009
### turin
You have explained the problem well enough, and I believe I can solve it, but it is against forum rules for me to provide any help until I see your attempt at a solution. Is there a reason why you need to put it into pdf format? I understand that using the tex feature on this forum is a bit frustrating, but you can just try to write out your solution in plane text here, and I will try to follow it.
5. Jan 30, 2009
### turin
When you integrated v to find x as a function of t, you did something wrong. I advise you to put limits on your integration, and put explicitly what is the differential quantity over which you're integrating.
6. Jul 6, 2009
### RyaniC
do you have any other simplier sulotion for rectilinear motion??
7. Jul 6, 2009
### turin
adashiu's approach is the simplest approach that I'm aware of. In fact, off the top of my head, I can't think of another way to do it.
Similar Discussions: Rectilinear Motion of Particle | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8870030641555786, "perplexity": 736.9492928669363}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320823.40/warc/CC-MAIN-20170626152050-20170626172050-00486.warc.gz"} |
http://tex.stackexchange.com/questions/102084/annoying-paragraph-spacing-issue-with-memoir | # Annoying paragraph spacing issue with memoir
I have a spacing issue while using the memoir class. The main problem is that after the first paragraph there is a line skip and an indentation and afterwards, all the paragraphs are indented properly and there is no line skip. Here is a MWE:
\documentclass[11pt,twoside,openright]{memoir}
\usepackage[size=pocket,trim,bleed]{createspace}
%\usepackage[paperwidth=4.25in, paperheight=6.875in,bindingoffset=.75in]{geometry}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{tgtermes}
\usepackage{mathpazo}
\usepackage[protrusion=true,expansion=true]{microtype}
\usepackage{lipsum}
%\usepackage{type1cm}
%\usepackage{lettrine}
%\checkandfixthelayout
% See the Memoir customise'' template for some common customisations
% Don't forget to read the Memoir manual: memman.pdf
%\title{TITLE OF BOOK}
%\author{NAME OF AUTHOR}
%\date{} % Delete this line to display the current date
%% BEGIN TITLE
\makeatletter
\def\maketitle{%
\null
\thispagestyle{empty}%
\vfill
\begin{center}\leavevmode
\normalfont
{\LARGE\raggedleft \@author\par}%
\hrulefill\par
{\huge\raggedright \@title\par}%
\vskip 1cm
% {\Large \@date\par}%
\end{center}%
\vfill
\null
\cleardoublepage
}
\makeatother
\author{AUTHOR}
%\author{NAME OF AUTHOR}
\title{TITLE}
%\date{}
%%% BEGIN DOCUMENT
\begin{document}
\pdftitle{TITLE}
\pdfauthor{AUTHOR}
\pdfsubject{SUBJECT}
\chapterstyle{bianchi}
\let\cleardoublepage\clearpage
\maketitle
\frontmatter
\null\vfill
\begin{flushleft}
Copyright \copyright
%\textit{TITLE}
All rights reserved.
ISBN:
ISBN--13:
\bigskip
\end{flushleft}
\let\cleardoublepage\clearpage
\clearpage
\tableofcontents
\chapter{Introduction}
\lipsum[1]
\lipsum[2]
\lipsum[3]
\mainmatter
\sloppy
%Input all of the chapter here
\backmatter
\end{document}
I also get an underfull \vbox which is something I do not know how to fix. Maybe the two are related?
EDIT:
I changed the document to fit createspace's guidelines but now the \vbox is back. I have attempted to use \vfil option but that is not working. What could be the issue?
\documentclass[11pt,twoside,openright]{memoir}
\usepackage{geometry}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{lipsum}
\geometry{
paperheight=8.00in,
top=.75in,
bottom=.75in,
paperwidth=5.25in,
inner=.38in,
outer=.75in,
bindingoffset=.75in,
}
\begin{document}
\chapterstyle{bianchi}
\tableofcontents*
\let\cleardoublepage\clearpage
\clearpage
\pagenumbering{roman}
\chapter{Introduction Chapter}
\vfil
\lipsum[1-10]
\mainmatter
\sloppy
%Input all of the chapter hermane
\pagenumbering{arabic}
\chapter{Awesome chapter}
\vfil
\lipsum[1-20]
\end{document}
UPDATE
I used \raggedbottom in the preamble as suggested before and that seems to have rid me of all of \vbox errors. I will look through the entire file and update again.
UPDATE 2
\raggedbottom fixed 99.99% of the issues except I get 1 overfull \vbox. The exact error is:
Overfull \vbox (13.59999pt too high) has occurred while \output is active []
-
## 1 Answer
The problem is that your settings and packages define a stretchable dimension for \parskip, i.e. a dimension which can increase or decrease (within some limits) in order of producing always a completely filled page (which is the \vbox).
TeX had troubles finding the point at which to end your first page. At some point, there was not enough space to put another line, but if he breaks the page at that point, there is not enough material to produce a completely filled page (i.e: the last line will not be aligned with the bottom). So it uses the stretchable space he can find in the page. Apparently the only stretchable space he found was \parskip. Even using that, the stretchabilty allowed by \parskip was not enough, so TeX had to stretch it beyond its limit (hence the Underful box message).
The "problem" has an easy solution:
1. Set \parskip=0pt. This disables its stretchability and the distance between paragraphs will be always zero, so when TeX cannot fill the page completely, it will insert space at the bottom and complain about Underfill vbox.
2. Put \raggedbottom in the preamble. This adds an infinitely stretchable space at the end of each page. This solution produces the same results than 2, but no Underfull messages will be produced, because that infinite glue will "absorb" all deficit.
Anyway, I suspect that the problem is that createspace style is trying to set all settings so that all pages have lines in a "grid", i.e. the baselines of all text are the same page after page. Probably first page breaks somehow the layout because of the title.
If I'm right, then you won't get more underfull boxes nor extra parskips in the remaining of the document, until the next chapter heading, which can break the layout again.
If this is the case, the better solution would be to insert stretchable space around the chapter heading. This way in those problematic pages TeX would choose that space to "absorb" the deficit, instead of choosing parskip. To do so:
\chapter{Introduction}
\vfil
For more information about stretchable glue you can read my answer to another question.
# Update
I did some experiments, and I concluded that I guessed correctly the causes and best solution of the problem.
The cause is that createspace tries to typeset all pages on the same grid, by enforcing the alignment of the bottom line of each page. However, the first page is different because of the chapter title, which introduces an spacing which is not multiple of baselineskip, and causes problems of alignment.
The following screenshot shows how, in your original document, the baselines of the first and second page do not match:
Using \raggedbottom technique makes the gap between paragraph to disappear, but worsens the problem of the baseline matching, because now the bottom page is not uniform (and the middle lines still do not match correctly):
Using \vfil after \chapter solves all the issues:
-
Thanks for the fantastic answer! However, I have one question. In the preamble, I should add \raggedbottom and then after the chapter heading, I should add \vfil right? – Jeel Shah Mar 12 '13 at 10:43
@gekkostate Updated answer, use only the \vfil trick and forget about \raggedbottom. – JLDiaz Mar 12 '13 at 10:56
Thanks for the response, it's working now! – Jeel Shah Mar 12 '13 at 11:10
After inserting the original text, the problem is back. With ipsum, it's working perfectly but with the new text it is not. It's evident that there is a problem with my text but what could it be? I have 1 \begin{quote} and that's it. – Jeel Shah Mar 12 '13 at 17:43
@gekkostate quote will introduce glue for example \setlength\partopsep{2\p@ \@plus 1\p@ \@minus 1\p@} in 10pt article class. – David Carlisle Mar 13 '13 at 1:34 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9129487872123718, "perplexity": 2061.051383177418}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-07/segments/1454701158609.98/warc/CC-MAIN-20160205193918-00141-ip-10-236-182-209.ec2.internal.warc.gz"} |
https://www.qb365.in/materials/stateboard/11th-business-maths-differential-calculus-model-question-paper-4832.html | #### Differential Calculus Model Question Paper
11th Standard
Reg.No. :
•
•
•
•
•
•
Business Maths
Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. Let $f\left( x \right) =\begin{cases} { x }^{ 2 }-4x\quad ifx\ge 2 \\ x+2\quad ifx<2 \end{cases}$, then f(5) is
(a)
-1
(b)
2
(c)
5
(d)
7
2. The graph of y = ex intersect the y-axis at
(a)
(0,0)
(b)
(1,0)
(c)
(0,1)
(d)
(1,1)
3. Which one of the following functions has the property f (x) = $f\left( \frac { 1 }{ x } \right)$
(a)
$f\left( x \right) =\frac { { x }^{ 2 }-1 }{ x }$
(b)
$f\left( x \right) =\frac { 1-{ x }^{ 2 } }{ x }$
(c)
f(x) = x
(d)
$f\left( x \right) =\frac { { x }^{ 2 }+1 }{ x }$
4. The graph of f(x) = ex is identical to that of
(a)
f(x) = ax, a > 1
(b)
f(x) = ax, a < 1
(c)
f(x) = ax, 0 < a < 1
(d)
y = ax +b, a $\ne$ 0
5. $\lim _{ x\rightarrow 0 }{ \frac { { e }^{ x }-1 }{ x } } =$
(a)
e
(b)
nx(n-1)
(c)
1
(d)
0
6. 5 x 2 = 10
7. Determine whether the following functions are odd or even?
f(x)=x+x2
8. Let f be defined by f(x) =x3-kx2+2x,x ∈ R,Find k,if 'f' is an odd function.
9. For $f(x)=\frac { x-1 }{ 3x+1 }$ ,write the expression of $f\left( \frac { 1 }{ x } \right)$ and $\frac { 1 }{ f(x) }$
10. Evaluate $\underset { h\rightarrow 0 }{ lim } \frac { \sqrt { x+h } -\sqrt { x } }{ h }$
11. Differentiate (sec x -1) (sec x +1)
12. 5 x 3 = 15
13. Differentiate sin2 x with respect to x2.
14. Evaluate the following $\lim _{ x\rightarrow \infty }{ \frac { 2x+5 }{ { x }^{ 2 }+3x+9 } }$
15. Find y2 of the following function x = a cos $\theta$, y = a sin $\theta$
16. Find $\frac{dy}{dx}$ if x = 15(t - sin t); y = 18(1 - cos t).
17. If ey (x + 1) = 1, show that $\frac { { d }^{ 2 }y }{ { dx }^{ 2 } } ={ \left( \frac { dy }{ dx } \right) }^{ 2 }$
18. 4 x 5 = 20
19. Draw the graph of the following function f(x)=e2x
20. Draw the graph of the following function f(x)=e-2x
21. If $\begin{matrix} \underset { x\rightarrow 1 }{ lim } & \frac { { x }^{ 4 }-1 }{ x-1 } \end{matrix}=\begin{matrix} \underset { x\rightarrow k }{ lim } & \frac { { x }^{ 3 }-{ k }^{ 3 } }{ { x }^{ 2 }-{ k }^{ 2 } } \end{matrix}$,then find the value of K
22. If $x=a\left( t+\frac { 1 }{ t } \right) ;y=a\left( t-\frac { 1 }{ t } \right)$ show that $\frac { dy }{ dx } =\frac { x }{ y }$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8682140111923218, "perplexity": 2323.599239209901}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540508599.52/warc/CC-MAIN-20191208095535-20191208123535-00442.warc.gz"} |
https://mathematica.stackexchange.com/questions/19638/why-doesnt-mathematica-make-an-obvious-simplification/19643 | # Why doesn't Mathematica make an obvious simplification?
I am doing some calculation with summation and the Kronecker symbol. Here are my steps :
$Assumptions = k1 ∈ Reals && k2 ∈ Reals && k3 ∈ Reals && p1 ∈ Reals && p2 ∈ Reals && p3 ∈ Reals k = {k1, k2, k3}; p = {p1, p2, p3}; d[i_, j_] := KroneckerDelta[i, j] proj[i_, j_, k1_, k2_, k3_] := d[i, j] - (d[i, 1]*k1 + d[i, 2]*k2 + d[i, 3]*k3)* (d[j, 1]*k1 + d[j, 2]*k2 + d[j, 3]*k3)/ (k1^2 + k2^2 + k3^2) test1 = proj[i, j, k1, k2, k3]*proj[i, j, p1, p2, p3]; test2 = Sum[Sum[test1, {i, 1, 3}], {j, 1, 3}] test2 // Expand To explain the steps: 1) I define$\vec{k}$and$\vec{p}$with real components. 2) I define a projector$P_{ij} \left( \vec{k} \right) = \delta_{ij} - \frac{k_i k_j}{k^2}$. 3) I compute a summation on the repeated subscript. After the last step, I have a relatively big expression, the product of k and p components. It looks like $$3-\frac{a}{a+b+c} - \frac{b}{a+b+c} - \frac{c}{a+b+c} +...-...$$ The a, b and c stands for k1, k2 and k3 (or p1, 2, 3). Now the question: why doesn't Mathematica make the simplification because, as anyone can see, the preceding expression can be simplified to$2 +...-...$Is the problem linked to the Expand operation? How can I make the simplification I want?. I thought of using /. to do it, but that doesn't work either. I hope someone will understand my question! • You can try using Simplify and related, but what you think it's a simpler expression will not necessarily match Mathematica's. – b.gates.you.know.what Feb 15 '13 at 10:23 • +1 just for formatting your code:) Simplify@test2 works nicely and returns (2 k2 k3 p2 p3 + 2 k1 p1 (k2 p2 + k3 p3) + k1^2 (2 p1^2 + p2^2 + p3^2) + k2^2 (p1^2 + 2 p2^2 + p3^2) + k3^2 (p1^2 + p2^2 + 2 p3^2))/((k1^2 + k2^2 + k3^2) (p1^2 + p2^2 + p3^2)) – Ajasja Feb 15 '13 at 10:34 ## 4 Answers You have to explicitly tell Mathematica to simplify expressions. You can do this using Simplify or FullSimplify Simplify@test2 (2 k2 k3 p2 p3 + 2 k1 p1 (k2 p2 + k3 p3) + k1^2 (2 p1^2 + p2^2 + p3^2) + k2^2 (p1^2 + 2 p2^2 + p3^2) + k3^2 (p1^2 + p2^2 + 2 p3^2))/((k1^2 + k2^2 + k3^2) (p1^2 + p2^2 + p3^2)) • Thank you for your answers. The problem when I use Simplify is that the form of the result is not "usable". I mean in the sense I want to use it. Because the calculation must lead to$1 - (\vec{k}.\vec{p})^2/(k^2*p^2)$. And with simplify, Mathematica doesn't do the factorization I want. I think I have to find an other way to do it, I may already have an idea. I thought I forget an assumption to enable Mathematica to do automatically this simplification. But it won't do what I didn't ask ! – Lalylulelo Feb 15 '13 at 10:52 I would use symbolic tensors instead of explicit tensors. First, let's reformulate your question using symbolic tensors: proj[k_] /; TensorRank[k] == 1 := With[{d = First @ TensorDimensions[k]}, Inactive[IdentityMatrix][d] - TensorProduct[k, k]/k.k ]$Assumptions = (k|p) ∈ Vectors[3];
test = TensorContract[TensorProduct[proj[k], proj[p]], {{1, 3}, {2, 4}}];
test //TeXForm
$\operatorname{TensorContract}\left[\left(\operatorname{IdentityMatrix}[3]-\frac{k\otimes k}{k.k}\right)\otimes \left(\operatorname{IdentityMatrix}[3]-\frac{p\otimes p}{p.p}\right),\left( \begin{array}{cc} 1 & 3 \\ 2 & 4 \\ \end{array} \right)\right]$
Note that TeXForm doesn't yet support Inactive, which is why it doesn't appear above. Also, I've overriden the default TeXForm formatting of \[TensorProduct] so that it looks like \otimes.
Mathematica doesn't (yet) have a symbolic identity tensor, so I use Inactive[IdentityMatrix][3] as a substitute. This means that TensorReduce can't really be used to simplify the output since it doesn't have support for my identity tensor substitute. I've written a package that helps augment TensorReduce to work with these identity tensors, which can be found here:
PacletInstall[
"TensorSimplify",
"Site" -> "http://raw.githubusercontent.com/carlwoll/TensorSimplify/master"
]
Once installed, you can load the package with:
<<TensorSimplify
Let's see this package in action on the above expression. First we need to use TensorReduce (TensorExpand would also work):
r1 = TensorReduce[test];
r1 //TeXForm
$-\frac{\operatorname{TensorContract}\left[k\otimes k\otimes \operatorname{IdentityMatrix}[3],\left( \begin{array}{cc} 1 & 3 \\ 2 & 4 \\ \end{array} \right)\right]}{k.k}-\frac{\operatorname{TensorContract}\left[p\otimes p\otimes \operatorname{IdentityMatrix}[3],\left( \begin{array}{cc} 1 & 3 \\ 2 & 4 \\ \end{array} \right)\right]}{p.p}+\operatorname{TensorContract}\left[\operatorname{IdentityMatrix}[3]\otimes \operatorname{IdentityMatrix}[3],\left( \begin{array}{cc} 1 & 3 \\ 2 & 4 \\ \end{array} \right)\right]+\frac{\operatorname{TensorContract}\left[k\otimes p,\left( \begin{array}{cc} 1 & 2 \\ \end{array} \right)\right]^2}{k.k p.p}$
Using TensorReduce causes the symbolic identity tensor to be contracted. The package function IdentityReduce can then be used to eliminate these contracted identity tensors:
r2 = IdentityReduce[r1];
r2 //TeXForm
$\frac{\operatorname{TensorContract}\left[k\otimes p,\left( \begin{array}{cc} 1 & 2 \\ \end{array} \right)\right]^2}{k.k p.p}-\frac{\operatorname{TensorContract}\left[k\otimes k,\left( \begin{array}{cc} 1 & 2 \\ \end{array} \right)\right]}{k.k}-\frac{\operatorname{TensorContract}\left[p\otimes p,\left( \begin{array}{cc} 1 & 2 \\ \end{array} \right)\right]}{p.p}+3$
Finally, the above expression is a mix of equivalent Dot and TensorContract objects. Using a common form will enable further simplifications. The less verbose version is obtained using the Dot representation (obtained by using the package function FromTensor):
FromTensor[r2]
1 + (k.p)^2/(k.k p.p)
I believe this is the form you're looking for. The package function TensorSimplify does all of the above steps:
TensorSimplify[test]
1 + (k.p)^2/(k.k p.p)
• Impressive! It was exactly the form I was looking for. I will have to test it. I think I figured out a solution by using replacements but yours is much more elegant. Thanks! – Lalylulelo Nov 12 '17 at 9:04
Not sure precisely what you want, but maybe it's this:
x = test2 // Expand;
x1 = PolynomialReduce[
Numerator[Together[x]], {Denominator[Together[x]]}, Variables[x]];
x2 = PolynomialReduce[x1[[2]], {k1^2 + k2^2 + k3^2}, Variables[x]];
x3 = PolynomialReduce[x2[[2]], {p1^2 + p2^2 + p3^2}, Variables[x]];
y = x1[[1, 1]] + x2[[1, 1]]/(p1^2 + p2^2 + p3^2) +
x3[[1, 1]]/(k1^2 + k2^2 + k3^2) +
x3[[2]]/((p1^2 + p2^2 + p3^2) (k1^2 + k2^2 + k3^2))
Here's the output in reverse order; there's an issue with copy/paste:
$\frac{2 \text{k1} \text{k2} \text{p1} \text{p2}+2 \text{k1} \text{k3} \text{p1} \text{p3}+2 \text{k2}^2 \text{p2}^2+\text{k2}^2 \text{p3}^2+2 \text{k2} \text{k3} \text{p2} \text{p3}+\text{k3}^2 \text{p2}^2+2 \text{k3}^2 \text{p3}^2}{\left(\text{k1}^2+\text{k2}^2+\text{k3}^2\right) \left(\text{p1}^2+\text{p2}^2+\text{p3}^2\right)}+\frac{-\text{k2}^2-\text{k3}^2}{\text{k1}^2+\text{k2}^2+\text{k3}^2}+\frac{-\text{p2}^2-\text{p3}^2}{\text{p1}^2+\text{p2}^2+\text{p3}^2}+2$
If you know approximately what denominators are obtained, you coud use command Collect[expression, factor]`. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8146632313728333, "perplexity": 4738.26158984011}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496669431.13/warc/CC-MAIN-20191118030116-20191118054116-00233.warc.gz"} |
https://muratbuffalo.blogspot.com/2018/01/ | ## Posts
Showing posts from January, 2018
### Paxos derived
Lamport's fault-intolerant state machine replication algorithm In 1978, Lamport published his classic "Time, Clocks, and the Ordering of Events in a Distributed System". As an application of logical clocks, he presented a distributed replicated state machine algorithm (and then he instantiated that algorithm to solve mutual exclusion as an example). Lamport complains that no one seemed to be aware of the distributed replicated state machine algorithm introduced in the paper: "This is my most often cited paper. Many computer scientists claim to have read it. But I have rarely encountered anyone who was aware that the paper said anything about state machines. People seem to think that it is about either the causality relation on events in a distributed system, or the distributed mutual exclusion problem. People have insisted that there is nothing about state machines in the paper. I’ve even had to go back and reread it to convince myself that I really did remember
Maurice Herlihy's paper: "Blockchains from a distributed computing perspective" explains the DAO attack as follows: "Figure 1 shows a fragment of a DAO-like contract, illustrating a function that allows an investor to withdraw funds. First, the function extracts the client's address (Line 2), then checks whether the client has enough funds to cover the withdrawal (Line 3). If so, the funds are sent to the client through an external function call (Line 4), and if the transfer is successful, the client’s balance is decremented (Line 5). This code is fatally flawed. In June 2016, someone exploited this function to steal about $50 million funds from the DAO. As noted, the expression in Line 3 is a call to a function in the client's contract. Figure 2 shows the client's code. The client's contract immediately calls withdraw() again (Line 4). This re-entrant call again tests whether the client has enough funds to cover the withdrawal (Line 3), and b ### Spring 18 Distributed Systems Seminar I considered doing a blast from the past edition of the seminar focusing only on classical papers published before 2000 . But, nah, I decided, I am doing a blockchain seminar instead. There has been many interesting papers on blockchains and this will be a good chance to catch up with those and look at the distributed systems, concurrency and coordination issues there. Here is the list. I thank Adem Efe Gencer for suggesting several interesting papers for this list. Blockchain papers: Blockchains from a Distributed Computing Perspective Blockstack: A Global Naming and Storage System Secured by Blockchains IPFS Bitcoin-NG: A Scalable Blockchain Protocol A Secure Sharding Protocol For Open Blockchains Enhancing Bitcoin Security and Performance with Strong Consistency via Collective Signing Service-Oriented Sharding for Blockchains The stellar consensus protocol: A federated model for internet-level consensus Smart contracts papers: Step by Step Towards Creating ### Erasable pens for editing papers I recently discovered the Pilot Frixion pens and I like them a lot. (I am not getting any advertisement money from them I swear :-) The pens have erasable ink, so they are great for marking your comments/edits on a paper while reading. They erase via heat. Each pen comes with a plastic nub, and if you apply friction to the page with the plastic nub at the top, and it erases the writing --mostly clean. A word of caution though, this means if you leave your writing in a hot car, you will find it erased, which you can remedy by putting it in a freezer. I am not kidding. So, don't use it for writing you want to keep permanently, but it is great for writing comments and marking on a paper when you are reading. I print the research paper I am reading and I do a lot of marking on paper. If I use a regular pen, I cross over some of my guesswork, nonsensical questions, or misinformed comments, and it messes up the paper. But using Frixion pens, I erase and modify my comments without ### Remember peer-to-peer systems? Traditionally computer systems use client server model. This is more of a centralized approach; server sits there and responds to clients requests. If one server is not enough for computation/analysis, a "hierarchical" organization of servers model is adopted in datacenter and cloud computing. One node becomes the master, other nodes act as workers. This is called the master-worker model. This simple model make sense if you have an infrastructure. Centralized control architecture is simple, so you can keep the coordination simple and efficient. Peer-to-peer model is on the other end of the spectrum: it calls for a fully decentralized system model. There is no distinguished master. Each node acts as both server and client, each node is a peer. This model does not require stable infrastructure and it can self-organize with what is presently available. As such, they are great for circumventing laws, bans, and censorship. In 2000s, peer-to-peer systems were all the craze ### Paper summary. A Berkeley view of systems challenges for AI This position paper from Berkeley identifies an agenda for systems research in AI for the next 10 years. The paper also serves to publicize/showcase their research, and steer interest towards these directions, which is why you really write position papers. The paper motivates the systems agenda by discussing how systems research/development played a crucial role in fueling AI’s recent success. It says that the remarkable progress in AI has been made possible by a "perfect storm" emerging over the past two decades, bringing together: (1) massive amounts of data, (2) scalable computer and software systems, and (3) the broad accessibility of these technologies. The rest of the paper talks about the trends in AI and how those map to their systems research agenda for AI. Trends and challenges The paper identifies 4 basic trends in the AI area: Mission-critical AI: Design AI systems that learn continually by interacting with a dynamic environment in a timely, robust, and ### The Lambda and the Kappa Architectures This article, by Jimmy Lin, looks at the Lambda and Kappa architectures, and through them considers a larger question: Can one size fit all? The answer, it concludes, is it depends on what year you ask! The pendulum swings between the apex of one tool to rule them all , and the other apex of multiple tools for maximum efficiency . Each apex has its drawbacks: One tool leaves efficiency on the table, multiple tools spawns integration problems. In the RDBMS world, we already saw this play out. One size RDBMS fitted all, until it couldn't anymore. Stonebraker declared "one size does not fit all", and we have seen a split to dedicated OLTP and OLAP databases connected by extract-transform-load (ETL) pipelines. But these last couple years we are seeing a lot of one size fits all "Hybrid Transactional/Analytical Processing (HTAP)" solutions being introduced again. Lambda and Kappa OK, back to telling the story from the Lambda and Kappa architectures perspecti ### Paper summary. TFX: A TensorFlow-Based Production-Scale Machine Learning Platform This paper from Google appeared at KDD 2017 Applied Data Science track. The paper discusses Google's quality assurance extensions to their machine learning (ML) platforms, called TensorFlow Extended (TFX). (Google is not very creative with names, they should take cue from Facebook.) TFX supports continuous training and serving pipelines and integrates best practices to achieve production-level reliability and scalability. You can argue that the paper does not have a deep research component and a novel insight/idea. But you can argue the same thing for the checklist manifesto by Atul Gowande, which nevertheless does not decrease from its effectiveness, usefulness, and impact. On the other hand, the paper could definitely have been written much succinctly. In fact, I found this blog post by Martin Zinkevich, the last author of the paper, much easier to follow than the paper. (Are we pushed to make papers artificially obfuscated to be publication-worthy?) This blog post on serv ### Why you should use modeling [with TLA+/PlusCal] I recently gave a two day seminar on "debugging your designs with TLA+/PlusCal" at Dell. So I wanted to write some of the motivation for modeling and debugging your models while this is still fresh in my mind. You need modeling No, not that kind of modeling! Actually the naming clash is not accidental after all: fashion designers need models to test/showcase their designs. You need modeling because: Failing to plan is planning to fail Everything is a distributed system The corner cases ... they are so many Do it for the development process Being smart does not scale Failing to plan is planning to fail This is from the paper, " Use of formal methods at Amazon Web Services , 2014". "Before launching any complex service, we need to reach extremely high confidence that the core of the system is correct. We have found that the standard verification techniques in industry (deep design reviews, code reviews, static code analysis, stress testing, ### Salute to Prof. Mohamed Gouda: Elegance in computing A couple months ago, I attended a special half-day workshop organized honoring Prof. Mohamed Gouda's contributions to computer science, and particularly the self-stabilizing systems community. Mohamed is the Mike A. Myers Centennial Professor at University of Texas at Austin . He has been at Austin Texas since 1980, for almost 40 years. His research contributions to the distributed systems has been phenomenal (borrowing a word Mohamed likes to use for things that excite him.) I am proud that Mohamed is my academic grandfather; he was the PhD advisor of my PhD advisor, Prof. Anish Arora. I wrote about "how to find your advisor" in my previous post, I hope elegance/rigor from Mohamed and Anish rubbed off on me a bit. At the workshop, there were about 10 talks technical in nature, but at the end of the talks, each speaker mentioned how their research and career has been enriched by Mohamed's contributions/help. I talked about my technical report on " Does t ### How to find your advisor I had tweeted this earlier about "Rocking your PhD": Find a hardworking advisor Get a senior PhD student mentor Read a lot of papers critically Write a lot, get feedback Publish your first paper early to build confidence Publish your 2nd, 3rd, 4th papers To sustain, exercise regularly It is that simple. This is actually a concise version of a longer advice I provided earlier. Since I haven't talked about it before, I like to now write some suggestions on finding an advisor. How to find your advisor Ask around and get advice from senior PhD students in the department about faculty as potential advisors. In the first semester of your graduate studies, take 3-4 classes you are interested in. This provides a good opportunity to meet and impress your prospective advisor. If there is a class project, go overboard and exceed expectations. Try to improve on an algorithm mentioned in the class, and discuss this with the prospective advisor. Before you ### Logical clocks and Vector clocks modeling in TLA+/PlusCal In a distributed system, there is no shared state, counter, or any other kind of global clock. So we can not implicitly associate an event with its time, because one node may have a different clock than another. Time synchronization is not easy to achieve, and failures complicate things. It turns out we care about time because of its utility in ordering of the events. Using this observation, in 1978, Leslie Lamport offered a time-free definition for "happens before": Event A happens before event B (denoted as A hb B) if and only if A can causally affect B. In the context of distributed systems, A hb B iff 1. A and B are on the same node and A is earlier in computation than B 2. A is the send of a message and B is the receive event for that message 3. There is some third event C, which A hb C, and C hb B. This also suggest the definition for "concurrent" relation. Events A and B are concurrent iff$\neg( A ~hb~ B) \land \neg( B ~hb~ A)\$ To capture the hb
I am a very curious natured person. Every child starts asking lots of questions around 3-4, but according to my mom, I took that to another level constantly asking "but why?" and drove her crazy. On the other hand, I believe I owe my being curious to my mom. She was an elementary school teacher (a damn good one), and was instrumental in my development. She was (and still is) a very curious person, and she taught me how to ask more and better questions. For example, while traveling, she would notice different plants and would ask me why the landscape is different here? And we would make guesses. The Turkish education system was not big on asking questions (these days it is waaaay waaaaay worse). Since the lazy path is to memorize and regurgitate answers, that is what it demanded from the students. But I think my questioning skills mostly survived. Among my friends, I was famous for replying questions with questions of my own, and if not, my answer was often "I don't | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6083565950393677, "perplexity": 1493.838529474049}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178375274.88/warc/CC-MAIN-20210306162308-20210306192308-00178.warc.gz"} |
https://stats.stackexchange.com/questions/246463/what-is-the-relationship-between-covariance-matrix-and-contour-plot | # What is the relationship between covariance matrix and contour plot?
From this video,
I deduced that here, $a==b$ and $c<0$.
Here are my questions,
(1) What does it mean by "equal loss values of errors"?
(2) What happens when a-priori probabilities of $C_1$ and $C_2$ are equal or unequal?
• Can you describe or copy the description of the plot/image? What do the ellipses we are seeing represent? Also, my guess for "equal loss values of errors" would be an output that gives the same error-value regardless of the actual label. So if $o$ is our output and $E$ is our error-function/cost-function: $E(o, C_1)==E(o,C_2)$ Nov 17 '16 at 11:27
• @dimpol, see the edit. Nov 17 '16 at 11:36
• If the horizontal and vertical axes are assumed to be drawn on the same scale, then it is not the case that $a=b$, because these describe the spreads of the data along those axes and the spreads clearly differ.
– whuber
Nov 17 '16 at 20:10
Assuming that both axes are on the same scale, you have $$a and $$c<0$$. The contour plot for a bivariate normal distribution with the specified covariance matrix is an ellipse of the form:
\begin{align} \text{const} &= \begin{bmatrix} x_a - \mu_a & x_b - \mu_b \end{bmatrix} \begin{bmatrix} a & c \\ c & b \end{bmatrix}^{-1} \begin{bmatrix} x_a - \mu_a \\ x_b - \mu_b \end{bmatrix} \\[12pt] &= \frac{1}{ab-c^2} \begin{bmatrix} x_a - \mu_a & x_b - \mu_b \end{bmatrix} \begin{bmatrix} b & -c \\ -c & a \end{bmatrix} \begin{bmatrix} x_a - \mu_a \\ x_b - \mu_b \end{bmatrix} \\[12pt] &= \frac{b (x_a - \mu_a)^2 - 2c (x_a - \mu_a) (x_b - \mu_b) + a (x_b - \mu_b)^2}{ab-c^2}, \\[6pt] \end{align}
where $$\mu_a$$ and $$\mu_b$$ are the means of the two variables. You can tell that $$c<0$$ because the ellipse slopes in the negative direction (i.e., from top-left to bottom-right). You can tell that $$a because the ellipse is narrower on the horizontal axis (for variable $$x_a$$) than on the vertical axis (for variable $$x_b$$).
• Kindly, write something on the relationship between $P(C_1)$ and $P(C_2)$. What happens when they are equal or unequal? Jul 22 at 17:02 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 9, "wp-katex-eq": 0, "align": 1, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7410582900047302, "perplexity": 465.4790314149777}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585280.84/warc/CC-MAIN-20211019171139-20211019201139-00362.warc.gz"} |
http://physics.stackexchange.com/questions/6936/a-water-drop-in-a-falling-lift | # A water drop in a falling lift
Consider a lift, which is at rest in an homogeneous gravity field. There is a thin layer(with thickness $h$) of water on the floor of the lift. At some moment a single cable, supporting the lift, breaks and the lift begins free falling(forever). It is easy to describe qualitatively what happens with water, i think: the formation of a drop begins. During this process the drop jumps up from the floor and once the total kinetic energy of the drop is dissipated into the heat, the center of the drop stands at some height $H$ from the floor. (All the kinetic energy of the drop is coming from the difference in surface tension energy of water between initial and end moments.)
Question: How to determine(approximately) $H$ ?
For simplicity let's assume that the cross-section of the lift is a disc-shaped with radius $R$. $(h<<R)$
Remark: A key point is to determine how the total kinetic energy distributes between internal kinetic energy and translational kinetic energy of the drop, i think. With this the problem will be solved.
So it is convenient at the early stage of formation of the drop ignore viscosity effects of water and air resistance.
Edit:
I would like to clarify that by internal kinetic energy i mean the kinetic energy of macroscopic motion of water inside the drop. At early stage there is no energy loss assumed, for simplicity.
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Downvoted because the question is much too vague. Even if a drop formed and started moving, why would it stop? The answer depends on knowing about the surface of the floor of the elevator, the air in the elevator, and requires taking into account thermodynamics effects. – Mark Eichenlaub Mar 15 '11 at 17:18
The only reason the water would form into a drop is the surface tension. You can work out the reduction in the energy stored in the surface tension in being a drop rather than a flat surface using a simple calc of the surface area. There's no particular reason I can see that the drop would float off the floor at all.
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You said it looses energy, well this has to go somewhere, so most likely into translation kinetic energy. – user1708 Mar 15 '11 at 10:29
@kakemonsteret: If the energy goes into translation kinetic energy then it will move and continue moving until it hits an obstacle. It will not float to a certain height and then stop. – delete Mar 15 '11 at 10:53
@mast Its in contact with air, and there is a temperature difference due to that kinetic energy, so as its coming into thermal equilibrium with the air its slowing down. This could take a while and it may never come to a full stop. Infact it could be in thermal equilibirum and still ahve translation kinetic energy, like rivers. – user1708 Mar 15 '11 at 10:56
@Master: The drop must stop because of air resistance. We neglect this resistance for simplicity during the formation of the drop only. – Martin Gales Mar 15 '11 at 11:22
Unless there is some inital temperature difference, its total kinetic energy is just its translational kinetic energy, which is the energy gained from its change in shape due to surface tension, from which you can get its temperature and also its velocity $v_0$.
You have the surface area, temperatures, conductivities, so you can get the heat transfer per time from fourier's law.
From which you can get the energy E(t), which gives you v(t), a solution to v(t)=0, if it exists, is T, then integrate v(t) from 0 to T to get H.
Most likely it wont come to a full stop, it could be in thermal equilibrium and still have translation kinetic energy, and even more likely it approaches velocity 0 asymptotically.
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Temperature is irrelevant in the problem, i think. At the early stage we ignore viscosity and assume that energy does not dissipate. By internal kinetic energy i meant macroscopic motion of water inside the drop. The translational motion of the drop decelerates by Stoke's law and it stops certainly. – Martin Gales Mar 15 '11 at 11:44 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5863131880760193, "perplexity": 468.7536267019433}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1414637898644.9/warc/CC-MAIN-20141030025818-00139-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://astronomy.stackexchange.com/questions/10952/photometer-vs-ccd-camera/10955 | # Photometer vs. CCD-camera
The Wikipedia article on photometry says that
These have largely been replaced with CCD cameras that can simultaneously image multiple objects, although photoelectric photometers are still used in special situations, such as where fine time resolution is required. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.485647976398468, "perplexity": 4541.30620739113}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400210616.36/warc/CC-MAIN-20200923081833-20200923111833-00208.warc.gz"} |
https://www.sarthaks.com/109050/using-crystal-theory-energy-level-diagram-write-electronic-configuration-central-metal | # Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion
+1 vote
9.8k views
Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following :
(i) [CoF6]3–, [Co(H2O)6]2+ , [Co(CN)6]3–
(ii) [FeF6]3–, [Fe(H2O)6]2+, [Fe(CN)6]4–
by (63.6k points)
selected by
No unpaired electron so diamagnetic
Since CN is strong field ligand all the electrons get paired.
No unpaired electron so diamagnetic. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8671435117721558, "perplexity": 17664.92713237282}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178357984.22/warc/CC-MAIN-20210226205107-20210226235107-00239.warc.gz"} |
http://mirlab.org/jang/books/dcpr/prExercise.asp?title=Chapter%205:%20Exercises&chapterTitle=Pattern%20Recognition%20(%E6%A8%A3%E5%BC%8F%E8%BE%A8%E8%AA%8D) | ## Chapter 5: Exercises
1. (*)Function for KNN search: Write a function knnSearch.m with the following usage:
[index, distance]=knnSearch(x, X, k)
where
• x: an input column vector of $d$-dimension
• X: a dataset matrix of $d$ by $n$, with each column being an observation
• k: no. of nearest neighbors to be retrieved
• index: a vector of k integers, representing the indices of the first k nearest neighbors (starting from the nearest one to the farthest one)
• distance: a vector of k element, representing the distances to these k nearest neighbors
(You can simply assume there is no ties in sorting the distance.)
Test case (You don't need to create the plots):
• Input: x=[7;8], X=[10 10 8 6 3 0 -3 -6 -8 -10 -10 -10 -8 -6 -3 0 3 6 8 10;0 3 6 8 10 10 10 8 6 3 0 -3 -6 -8 -10 -10 -10 -8 -6 -3], k=5.
• Output: index=[4 3 5 2 6], distance=[1 2.23606797749979 4.47213595499958 5.8309518948453 7.28010988928052].
• Input: x=[40;50], X=[13 51 36 79 68 74 81 90 37 82 77 58 48 69 95 91 81 71 29 79 23 90 34 14 74 8 57 60 15 58;99 12 5 2 31 61 95 24 57 49 49 16 20 47 40 43 76 41 59 77 34 51 93 9 54 87 54 49 94 71], k=5.
• Output: index=[9 19 27 28 21], distance=[7.61577310586391 14.2126704035519 17.464249196573 20.0249843945008 23.3452350598575].
1. What is the full name for KNNC?
2. Please describe the basic principle of KNNC.
3. Give the major strength and drawback of KNNC.
3. (*)Voronoi diagram:
1. Given 3 points in a plane, draw its Voronoi diagram.
2. Given 4 points in a plane, draw its Voronoi diagram.
4. (*)Single-layer perceptrons:
1. What is the equation for computing the output of a 2-input single-layer perceptron?
2. What are the learning rules of the 3 parameters in the above equation?
5. (**)Surface and contour plots of 2D Gaussian distributions: Write a script to draw both surface and contour plots of a 2D Gaussian distributions with the following parameters:
1. m = [0, 0]T, S = [1 0; 0 1] (an identity matrix).
2. m = [0, 0]T, S = [1 0; 0 5] (a diagonal matrix).
3. m = [0, 0]T, S = [1 2; 2 5] (a positive-definite matrix).
4. m = [0, 0]T, S = [-1 2; 2 -5]*50 (an arbitrary matrix).
Your plots should be similar to the one shown next:
You should choose a range that can display important characteristics of these plots. Please explain why the plots of (d) are very different from those of the other cases.
(Hint: You can follow the self demo part of gaussian.m.)
1. Why the classifier is named "quadratic"?
2. How do you train a quadratic classifier?
3. How do you evaluate (test) a quadratic classifier?
4. What is the major strength of a quadratic classifier?
5. What is the major weakness of a quadratic classifier?
6. If a quadratic classifier has a diagonal covariance matrix, does it fall back to a naive Bayes classifier? Why?
7. (*)Naive Bayes classifier:
1. How do you train a naive Bayes classifier?
2. How do you evaluate (test) a naive Bayes classifier?
3. What is the major strength of a naive Bayes classifier?
4. What is the major weakness of a naive Bayes classifier?
8. (**)KNNC on IRIS: recognition rates w.r.t. number of clusters: Please modify the example in order to test the recognition rates of KNNC with respect to the numbers of clusters.
1. Write a script knncIrisRrVsClusterNum01.m to display the recognition rates for both inside and outside tests. Your plot should be similar to the one shown next:
This is an example of exhaustive search that can be used to find the best number of clusters for KNNC.
2. Write a script knncIrisRrVsClusterNum02.m that repeats the previous subproblem but reverse the roles of training and test sets. Your plots should be similar to the one shown next:
3. Write a script knncIrisRrVsClusterNum03.m that combine previous two subproblems to plot the average recognition rates for both inside and outside tests. Your plot should be similar to the one shown next:
This method of switching the role of training and test sets for identify the average recognition rates are referred to as two-fold cross validation. We can extend the concept to K-fold cross validation in which at K-th iteration, only 1/K of the data is for test while the others are for training. This is a more robust method for estimating the performance of the constructed classifier. In general, the inside-test recognition rate should increase with the number of clusters. On the other hand, the outside-test recognition rate should increase initially and then decrease eventually. Usually we take the number of clusters that can maximize the out-side recognition rate for the construction of KNNC classifier.
9. (**)KNNC on WINE: recognition rates w.r.t. number of clusters: Use prData.m to obtain the WINE dataset and repeat the previous exercise to get 3 plots.
10. (*)Various classifiers on WINE dataset: Use prData.m to obtain the WINE dataset. Use the following classifiers to obtain the recognition rates of both inside and outside tests. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5656598806381226, "perplexity": 803.2834341681513}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-22/segments/1495463607813.12/warc/CC-MAIN-20170524112717-20170524132717-00477.warc.gz"} |
http://arblib.org/overview.html | # Feature overview¶
Arb builds upon FLINT, which deals with efficient computation over exact domains such as the rational numbers and finite fields. Arb extends FLINT to cover computations with real and complex numbers. The problem when computing with real and complex numbers is that approximations (typically floating-point numbers) must be used, potentially leading to incorrect results.
Ball arithmetic, also known as mid-rad interval arithmetic, is an extension of floating-point arithmetic in which an error bound is attached to each variable. This allows computing rigorously with real and complex numbers.
With plain floating-point arithmetic, the user must do an error analysis to guarantee that results are correct. Manual error analysis is time-consuming and bug-prone. Ball arithmetic effectively makes error analysis automatic.
In traditional (inf-sup) interval arithmetic, both endpoints of an interval $$[a,b]$$ are full-precision numbers, which makes interval arithmetic twice as expensive as floating-point arithmetic. In ball arithmetic, only the midpoint m of an interval $$[m \pm r]$$ is a full-precision number, and a few bits suffice for the radius r. At high precision, ball arithmetic is therefore not more expensive than plain floating-point arithmetic.
Joris van der Hoeven’s paper [Hoe2009] is a good introduction to the subject.
Other implementations of ball arithmetic include iRRAM and Mathemagix. Arb differs from earlier implementations in technical aspects of the implementation, which makes certain computations more efficient. It also provides a more comprehensive low-level interface, giving the user full access to the internals. Finally, it implements a wider range of transcendental functions, covering a large portion of the special functions in standard reference works such as [NIST2012].
Arb is designed for computer algebra and computational number theory, but may be useful in any area demanding reliable or precise numerical computing. Arb scales seamlessly from tens of digits up to billions of digits. Efficiency is achieved by low level optimizations and use of asymptotically fast algorithms.
Arb contains:
• A module (arf) for correctly rounded arbitrary-precision floating-point arithmetic. Arb’s floating-point numbers have a few special features, such as arbitrary-size exponents (useful for combinatorics and asymptotics) and dynamic allocation (facilitating implementation of hybrid integer/floating-point and mixed-precision algorithms).
• A module (mag) for representing magnitudes (error bounds) more efficiently than with an arbitrary-precision floating-point type.
• A module (arb) for real ball arithmetic, where a ball is implemented as an arf midpoint and a mag radius.
• A module (acb) for complex numbers in rectangular form, represented as pairs of real balls.
• Modules (arb_poly, acb_poly) for polynomials or power series over the real and complex numbers, implemented using balls as coefficients, with asymptotically fast polynomial multiplication and many other operations.
• Modules (arb_mat, acb_mat) for matrices over the real and complex numbers, implemented using balls as coefficients. At the moment, only rudimentary linear algebra operations are provided.
• Functions for high-precision evaluation of various mathematical constants and special functions, implemented using ball arithmetic with rigorous error bounds.
Arb 1.x used a different set of numerical base types (fmpr, fmprb and fmpcb). These types had a slightly simpler internal representation, but generally had worse performance. All methods for the Arb 1.x types have now been ported to faster equivalents for the Arb 2.x types. The last version to include both the Arb 1.x and Arb 2.x types and methods was Arb 2.2. As of Arb 2.9, only a small set of fmpr methods are left for fallback and testing purposes.
Arb uses GMP / MPIR and FLINT for the underlying integer arithmetic and various utility functions. Arb also uses MPFR for testing purposes and internally to evaluate some functions. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.472004234790802, "perplexity": 2029.0038750860115}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-09/segments/1487501171043.28/warc/CC-MAIN-20170219104611-00600-ip-10-171-10-108.ec2.internal.warc.gz"} |
https://brilliant.org/problems/placing-satellites/ | # Placing satellites
In a geostationary orbit around the earth satellites are to be placed at equal distances from each other in such a manner that each satellite can see every other during any instant of its motion.Find the maximum no of satellites that can be placed in such a manner.Assume that the space station cant send more than 10 satellites.Assume that the orbits are circular.
× | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8236696124076843, "perplexity": 486.08652891439107}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281746.82/warc/CC-MAIN-20170116095121-00015-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://asmedigitalcollection.asme.org/OMAE/proceedings-abstract/OMAE2016/49989/V007T06A017/281050 | In this study, numerical computation was carried out for evaluating the effects of the design parameter variations on the added resistance of Aframax tanker in head seas. The design of experiments (DOE) was used to efficiently conduct the numerical simulations with the hull form variations and save computational resources. A computational fluid dynamics (CFD) code based on the continuity and Reynolds averaged Navier-Stokes (RANS) equation was used for the numerical simulation. The simulation was performed in a short wave condition where the wave length was half of the ship length, which is expected to be most frequent in the vessel operation. Five design parameters of fore-body hull form were selected for the variations: design waterline length (DWL), bulbous bow height (BBH), bulbous bow volume (BBV), bow flare angle (BFA) and bow entrance angle (BEA). Each parameter had two levels in the variations, thus total 32 cases were designed initially. The results of the numerical simulations were analyzed statistically to determine the main effects and correlations in the five design parameters variations. Among them, the most significant parameter that influences on the added resistance in waves was DWL, followed by BBV and BEA. The other parameters had little effects on the added resistance in waves. By the computations, it was revealed that Extending DWL and decreasing BEA promoted the reflection of waves more toward the side than forward. In addition, there existed two-way interactions for the following two-factor combinations: DWL-BFA, DWL-BEA, DWL-BBV, BBH-BBV.
This content is only available via PDF. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8514020442962646, "perplexity": 1794.9767924695589}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571987.60/warc/CC-MAIN-20220813202507-20220813232507-00374.warc.gz"} |
https://www.physicsforums.com/threads/intergration-1-x-2-0-5.135112/ | # Intergration (1-(X^2))^0.5
1. Oct 6, 2006
### Sink41
EDIT: my tex is a little broken trying to fix
So i want to intergrate
$$\int (1 - x^2)^\frac{1}{2} dx$$
i start off by saying
$$\sin u = x$$
so
$$\frac {dx} {du} = \cos u$$
then
$$\int (1 - x^2)^\frac{1}{2} \cos u du$$
which is
$$\int \cos^2 u du$$
and
$$\cos2u = 2cos^2 u - 1$$
so therefore
$$\frac {1} {2} \cos2u + \frac {1} {2}= cos^2 u$$
so you intergrate
$$\int \frac {1} {2} \cos 2u + \frac {1} {2} du$$
which is
$$\frac {1} {4} \sin 2u + \frac {u} {2}$$
and
$$\sin 2u = 2\sin u \cos u = 2\sin u(1 - sin^2 u)^\frac {1} {2}$$
putting x into u gets
$$\frac {x} {2} (1 - x^2)^\frac {1} {2} + \frac {\sin^-1 x} {2}$$
which im pretty sure is wrong. So can someone show me how to intergrate (1-(X^2))^0.5 ? i think that using x = sinu is wrong but u = sinx doesnt get me far either. Probably something simple ive overlooked.
Last edited: Oct 6, 2006
2. Oct 6, 2006
### arildno
Absolute Values...
3. Oct 6, 2006
thats correct
4. Oct 6, 2006
### Sink41
Is that a subtle hint to stick the natural log function in there? because if you say
$$u = 1 - x^2$$
then
$$\int \frac{u^\frac{1}{2}}{(4 - 4u)^\frac{1}{2}} du$$
which looks sort of f'(x)/f(x) ish... ok tbh i have no clue why you said absolute value except it means always positive and is often in log when intergrating for some reason?
5. Oct 6, 2006
### arildno
$$\sqrt{x^{2}}=???$$
6. Oct 6, 2006
### Sink41
EDIT: tex is a work in progress... again :\
I'm guessing due to the fact -x and x give the same answer
$$\sqrt{x^{2}}=|x|$$
So
$$(1-(X^2))^\frac {1}{2} = (1-(|x| ^2))^\frac {1}{2}$$
$$\frac {x} {2} (1 - |x| ^2)^\frac {1} {2} + \frac {\cosec x} {2}$$
I'm worried about the fact trig has appeared in the intergral because f(x) didnt have any? And differential of cosec x is -cosecx cotx ???
Last edited: Oct 6, 2006
7. Oct 6, 2006
### arildno
No..according to your (correct guess we must have:
$$(\cos^{2}(u))^{\frac{1}{2}}=|\cos(u)|$$
agreed?
8. Oct 6, 2006
### Sink41
OK... so when i change cosu to sinu... since i have
$$(\cos^{2}(u))^{\frac{1}{2}}=(1 - \sin^{2}(u))^{\frac{1}{2}}$$
then i get
$$(|1 - sin{2}(u)|)^\frac{1}{2}$$ out of it?
$$\frac {x} {2} (|1 - x^{2}|)^\frac {1} {2} + \frac {\sin^{-1}(x)} {2}$$
Last edited: Oct 6, 2006
9. Oct 6, 2006
### arildno
10. Oct 6, 2006
### Sink41
instead of $$\int \cos^2 u du$$
i should have
$$\int \cos(u) | \cos(u) | du$$
???
11. Oct 6, 2006
### arildno
That is correct!
12. Oct 7, 2006
### Sink41
Ok so how do i intergrate
$$\int \cos(u) | \cos(u) | du$$
???
btw i found a trial of a program called "Derive 6" on a demo disk i got from a maths course. It intergrated
$$\int (1 - x^2)^\frac{1}{2} dx$$
like this (click on thumbnail for bigger picture):
Using that method can you avoid absolute values? I tried putting
$$\int \cos(u) | \cos(u) | du$$
into it and it didnt like it much. Got stuck if you tried to get it to do it step by step. This is what it got if you went straight to the answer.
I don't think it likes or uses absolute values much. When i told it to intergrate tanx it didnt use absolute values in the answer unlike my text book. So i'm hoping intergrating |cosx| isnt hard or complicated and the programs messing up?
13. Oct 7, 2006
### arildno
Well, the maximal domain of your x-integrand is -1 to 1.
Divide your u-interval into those regions where the cosine is negative, and those where it is positive.
You lose no generality by assumin $0\leq{u}\leq{\pi}$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9437602758407593, "perplexity": 6116.816351571291}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988722951.82/warc/CC-MAIN-20161020183842-00205-ip-10-171-6-4.ec2.internal.warc.gz"} |
http://mathoverflow.net/users/20746/jan-vesel%c3%bd | # Jan Veselý
less info
reputation
19
bio website location age member for 2 years, 7 months seen Nov 20 '13 at 19:50 profile views 359
# 7 Questions
10 C*-algebras with bizzarre structure of projections 5 Left ideals vs right ideals 4 Density character of $\ell_\infty(\kappa, S)$ 3 When an AW*-algebra is a W*-algebra 3 Polar decomposition in C*-algebras
# 312 Reputation
+25 C*-algebras with bizzarre structure of projections +70 An extreme point of the ball of the space of compact operators +10 Density character of $\ell_\infty(\kappa, S)$ -2 Almost isometric subspaces of $\ell_p$
7 An extreme point of the ball of the space of compact operators
# 13 Tags
7 banach-spaces × 3 0 von-neumann-algebras × 2 7 operator-norms 0 set-theory × 2 7 hilbert-spaces 0 banach-algebras 0 fa.functional-analysis × 4 0 abstract-algebra 0 c-star-algebras × 3 0 local-rings
# 2 Accounts
MathOverflow 312 rep 19 Mathematics 288 rep 19 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6020664572715759, "perplexity": 4600.497848373956}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1408500835699.86/warc/CC-MAIN-20140820021355-00115-ip-10-180-136-8.ec2.internal.warc.gz"} |
https://socratic.org/questions/what-is-the-vertex-form-of-3y-2x-3-x-3 | Algebra
Topics
# What is the vertex form of 3y=(2x − 3)(x - 3) ?
Nov 23, 2017
$y = \frac{2}{3} {\left(x - \frac{9}{4}\right)}^{2} - \frac{3}{8}$
#### Explanation:
$\text{the equation of a parabola in "color(blue)"vertex form}$ is.
$\textcolor{red}{\overline{\underline{| \textcolor{w h i t e}{\frac{2}{2}} \textcolor{b l a c k}{y = a {\left(x - h\right)}^{2} + k} \textcolor{w h i t e}{\frac{2}{2}} |}}}$
$\text{where "(h,k)" are the coordinates of the vertex and a}$
$\text{is a multiplier}$
$\text{to express "3y=(2x-3)(x-3)" in this form}$
$\Rightarrow 3 y = 2 {x}^{2} - 9 x + 9$
• " the coefficient of the "x^2" term must be 1"
$\Rightarrow 3 y = 2 \left({x}^{2} - \frac{9}{2} x + \frac{9}{2}\right)$
• " add/subtract "(1/2"coefficient of x-term")^2
$\text{to } {x}^{2} - \frac{9}{2} x$
$3 y = 2 \left({x}^{2} + 2 \left(- \frac{9}{4}\right) x \textcolor{red}{+ \frac{81}{16}} \textcolor{red}{- \frac{81}{16}} + \frac{9}{2}\right)$
$\textcolor{w h i t e}{3 y} = 2 {\left(x - \frac{9}{4}\right)}^{2} - \frac{9}{8} \leftarrow \textcolor{b l u e}{\text{divide by 3}}$
$\Rightarrow y = \frac{2}{3} {\left(x - \frac{9}{4}\right)}^{2} - \frac{3}{8} \leftarrow \textcolor{red}{\text{in vertex form}}$
##### Impact of this question
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http://freneticarray.com/painting-gabriels-horn/ | Frenetic Array
The intersection of logic and imagination.
There are many things in the world of mathematics that are really quite wonderful — however, I am not sure there will be anything more wonderful yet unintuitive than Gabriel's Horn.
Gabriel's Horn is thus: suppose you have the function $y = \frac{1}{x}$ where $x \in \mathbb{R}^+, 1 \leq x \leq \infty$, rotated around the $x$ axis; not too difficult to conceptualize, it looks like a horn of sorts. But here's the paradox.
Suppose we want to calculate the volume. Simple enough, using solids of revolution, we can show the volume to be:
$$V = \pi \lim_{t \rightarrow \infty} \int _1 ^t \frac{1}{x^2} dx = \pi \lim _{t \rightarrow \infty} ( 1 - \frac{1}{t} ) = \pi$$
A simple, elegant solution; we can expect the volume to be exactly $\pi$. So, let's see about the surface area.
We know the general definition of the arc length to be $\int _a ^b \sqrt{1 + f'(x)^2}$, so combining this with our solids of revolution, we should get
$$A = 2\pi \lim _{t \rightarrow \infty} \int _1 ^t \frac{1}{x} \sqrt{1 + \left( -\frac{1}{x^2} \right)^2 } dx$$
However, this is not a trivial integral; however, there is a trick we can do. Suppose we take the integral $$2\pi \lim _{t \rightarrow \infty} \int _1 ^t \frac{dx}{x}$$ instead, and we can prove this integral will always be equal to or smaller than the former integral (because of the disappearance of $\sqrt{1 + (-\frac{1}{x^2})}$). So, taking this rather trivial integral, we can see that
$$A \geq 2\pi \lim _{t \rightarrow \infty} \int _1 ^t \frac{dx}{x} \implies A \geq \lim _{t \rightarrow \infty} 2\pi \ln(t)$$
Wait a minute; it's divergent! So we know the volume $V = \pi$, but the surface area $A \geq \infty$. This is no mistake, the math is valid. And that is simply wonderful.
A horn you can fill with paint, but you can't paint the surface. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9873320460319519, "perplexity": 330.1100098910929}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-13/segments/1552912203947.59/warc/CC-MAIN-20190325112917-20190325134917-00067.warc.gz"} |
http://nrich.maths.org/6127/index?nomenu=1 | 'Randomness and Brownian Motion' printed from http://nrich.maths.org/
Randomness and Brownian Motion
In Classical times the Pythagorean philosophers believed that all things were made up from a specific number of tiny indivisible particles called 'monads'. Each object contained a different number of particles, and so they believed that 'everything was number'. Other philosophers held similar views, and today we call them 'atomists'.
The Roman Poet Titus Lucretius Carus (c.99-c.55 BCE) the author of On the Nature of Things
The Roman poet and philosopher Lucretius wrote On the Nature of Things (c. 60 CE) where he described the motion of dust particles dancing in the light of a sunbeam, and attributed their motion to the invisible blows of atoms. Nowadays we might explain this by the small currents of air moving the dust, but there are other situations where we can see this happening. For example, in the school laboratory, it is possible to see this kind of motion with Lycopodium Powder [see note 1] floating on water and viewed under a microscope.
What is moving the particles of powder?
Robert Brown (1773-1858) The 'jiggling' of pollen grains he saw is now called 'Brownian Motion'
In 1827 the botanist Robert Brown noticed that if you looked at pollen grains in water through a microscope, the pollen jiggles about. He called this jiggling 'Brownian motion', but Brown couldn't understand what was causing it. He thought at first the pollen must be alive, but after testing the phenomenon with fine dust particles, he confirmed that the movement was not due to any living organism.
Interestingly, much earlier, the Dutch Physician Jan Ingenhousz had investigated a number of chemical and physical phenomena and described similar irregular motion of coal dust particles on the surface of alcohol in 1785, but as with Brown, the phenomenon did not attract much scientific attention.
John Dalton (1766-1844) Often called the 'Father of Modern Chemistry'. He was the principal proponent of an atomic theory and published the first table of relative atomic weights.
In 1800, John Dalton (1766-1844), a Quaker from Cumbria became the Secretary of the Manchester Literary and Philosophical Society [see note 2]. Dalton became one of the most important chemists of his time and through his experimental work promoted the first systematic ideas of an atomic theory. As with all scientific theories, there were many people who contributed their views, and Dalton's achievements rested on those of a number of scientists from France and England [see note 3].
The first person to describe the mathematics behind Brownian motion was the Danish astronomer Thorvald Thiele in 1880, and later, in 1900, Louis Bachelier a French mathematician, wrote his PhD thesis on the 'Theory of Speculation', which was the first ever mathematical analysis of the stock and option markets. Bachelier's work also provided a mathematical account of Brownian Motion.
The curious thing was, that while most scientists were convinced that atoms existed, because the atomic theory was able to explain many physical and chemical processes, having a mathematical account does not prove that atoms exist and by the beginning of the 20th century, nobody had been able to produce an experimental proof of their existence.
A portrait of Albert Einstein in 1905. During this year he was working as a clerk in the Swiss Patent Office where he produced his four famous papers on The Nature of Light, Brownian Motion, Special Relativity and Mass-Energy Equivalence [see note 4].
In 1905, Einstein became interested in the phenomenon of Brownian Motion, and in the same year he published three papers which finally came up with an explanation.
Einstein realised that the jiggling of the pollen grains seen in Brownian motion was due to molecules of water hitting the tiny pollen grains, like children randomly kicking a ball in a playground. The pollen grains were visible but the water molecules were not, which was why it looked like the pollen was bouncing around on its own.
Einstein also showed that it was possible to work out how many molecules were hitting a single pollen grain and how fast the water molecules were moving - all by looking at the pollen grains.
The Polish Physicist Marian Smoluchowski (1872-1917) In 1906 he produced the mathematical equations that described the Random Processes in Brownian Motion.
Einstein's papers together with the independent work of the Polish scientist Marian Smoluchowski (1872-1917) in 1906 brought the solution of the problem to the attention of physicists, and presented it as a way to indirectly confirm the existence of atoms and molecules.
At last scientists had made predictions about the properties of atoms that could actually be tested. The French physicist Jean Perrin (1870-1942) then used Einstein's predictions to work out the size of atoms and remove any remaining doubts about their existence.
Relative Molecule Sizes
Now think of the pollen particle you can see under the microscope swimming randomly in water.
One molecule of water is about 0.1 to 0.2 nano-metres ($10^{-9}$ metres), (a hydrogen-bonded cluster of 300 atoms has a diameter of approximately 3 nano-metres) where the pollen particle is roughly 1 micro-metre ($10^{-6}$ metres)in diameter, roughly 10,000 times larger than a water molecule. So, the pollen particle can be considered as a very large balloon constantly being pushed by water molecules. The Brownian motion of particles in a liquid is due to the instantaneous imbalance in the force exerted by the small liquid molecules on the particle.
The Mathematics of Randomness now applies to many aspects of our everyday life, though we may not be aware of it. Not only to the movement of atoms, but also to anything that has irregular movement or irregular appearance like the stock market, the identification of images, analysis of fingerprints, testing forgery of paintings and other art objects, tracking animals, gambling, gene mutation, signal communication, computer simulations, the list goes on. It is one of the exciting things about being a mathematician that the same piece of mathematics can get modified and applied to some of the most unexpected aspects of our lives.
Notes
1. Lycopodium powder is a fine yellow powder derived from the spores of Lycopodium clavatum (stag's horn club moss, running ground pine).
2. In the later 18th Century, a number of 'Literary and Philosophical' societies existed in England to promote literacy and technical education for working people, and to develop new industrial processes.
3. In particular, Joseph Priestly (1733-1804) in England, and Antoine Lavoisier (1743-2794), and Joseph Luis Gay-Lusac (1778-1850) in France.
4. $E =mc^2$
References
Einstein, A. (1956) Investigations on the Theory of the Brownian Motion. New York Dover Books
Nott, M. (2005) Association for Science Education School Science Review "Molecular reality: the contributions of Brown, Einstein and Perrin" (39 - 46) .
The story of Brownian motion and its importance in modern science | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6523560881614685, "perplexity": 1565.2593809687792}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398447881.87/warc/CC-MAIN-20151124205407-00138-ip-10-71-132-137.ec2.internal.warc.gz"} |
https://kb.osu.edu/dspace/handle/1811/11547 | SPECTRAL CHARACTERIZATION OF MATRIX ISOLATED MOLECULAR IONS
Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/11547
Files Size Format View
1981-MF-04.jpg 79.74Kb JPEG image
Title: SPECTRAL CHARACTERIZATION OF MATRIX ISOLATED MOLECULAR IONS Creators: Kelsall, Benuel L.; Andrews, Lester Issue Date: 1981 Publisher: Ohio State University Abstract: Matrix isolation has proven to be a very useful technique for the characterization of molecular ions. Ions produced by photoionization techniques are trapped in the an excess of an inert gas such as argon for study with conventional spectroscopic instrumentation. Sharp spectra for matrix isolated ions in the infrared, visible and ultraviolet regions of the spectrum provide information pertaining to molecular geometry, bonding and photochemistry which cannot be obtained by other commonly employed techniques for ion study. Various methods for ion production including an electric are technique and a multiphoton ionization process will be discussed. In addition, the application of high resolution ($0.2 cm^{-1}$) Fourier-transform infrared spectroscopy, as it pertains to the study of molecular ions, will be discussed. Description: Author Institution: URI: http://hdl.handle.net/1811/11547 Other Identifiers: 1981-MF-4 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4914551079273224, "perplexity": 3937.132836794192}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560282631.80/warc/CC-MAIN-20170116095122-00273-ip-10-171-10-70.ec2.internal.warc.gz"} |
http://physics.stackexchange.com/questions/78524/boltzmann-distribution-with-interaction-between-particles | # Boltzmann distribution with interaction between particles?
First of all, I would like to apologize in advance if I make stupid mistakes. I am a mathematician and I am trying to apply the Boltzmann distribution to places where I am not sure if it is applicable (albeit I have no choice).
The situation is: I have a system which consists in a discrete line of $M$ positions in which $N$ elements are distributed with a separation of at least $D$ positions between them. The state of each element should be its position in the line. Finally, (here's the fun part) each position in the line has an associated potential (so putting an element in the position $i$ means spending $\epsilon_{i}$ units of Energy). The usual approach to this problem as far as I have seen is just assigning $p_{i} = e^{-\epsilon_{i}/kT}$, where $p_{i}$ is the probability that there is an element in the position $i$.
I don't understand this approach and I am trying to derive that new one, but I am stuck when trying to force the particles to be separated. Any insight or reference would be very much appreciated.
Edit: If it is needed, we can also say that the particles might have a velocity (i.e. they can oscillate), but they should not be able to pass through each other.
-
Sure, it's no problem to do this. The thing that has to change is that $i$ should index over all possible configurations of the $N$ elements, and the energy in the Boltzmann distribution has to be the total energy of the system.
So if $M=10$, $N=3$ and $D=2$ then, for example, $$p([1,0,0,1,0,0,1,0,0,0]) = \frac{1}{Z}e^{-\frac{\epsilon_1 + \epsilon_4 + \epsilon_7}{kT}},$$ but $$p([1,0,1,0,0,0,1,0,0,0]) = 0$$ because it's not allowed by the constraint.
To calculate the normalising factor (or "partition function") $Z$, you have to sum over all allowed configurations of the system. It isn't immediately obvious (to me) how to do that analytically in this case, but you're the mathematician so I'm sure you can find an elegant way.
Incidentally, you should be able to see that if there are no interactions between the $M$ positions then this reduces to the formula you originally quoted.
I'm glad to help. Yes, no interactions means that the probability of each of the $M$ slots being occupied is independent of whether any of the other slots are occupied. That means no restriction on the distances $D$ or on the total number of particles $N$. – Nathaniel Sep 26 '13 at 0:42 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8102367520332336, "perplexity": 116.48337270206305}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042992543.60/warc/CC-MAIN-20150728002312-00137-ip-10-236-191-2.ec2.internal.warc.gz"} |
https://converter.ninja/volume/uk-tablespoons-to-centiliters/290-brtablespoon-to-cl/ | # 290 UK tablespoons in centiliters
## Conversion
290 UK tablespoons is equivalent to 435 centiliters.[1]
## Conversion formula How to convert 290 UK tablespoons to centiliters?
We know (by definition) that: $1\mathrm{brtablespoon}\approx 1.5\mathrm{centiliter}$
We can set up a proportion to solve for the number of centiliters.
$1 brtablespoon 290 brtablespoon ≈ 1.5 centiliter x centiliter$
Now, we cross multiply to solve for our unknown $x$:
$x\mathrm{centiliter}\approx \frac{290\mathrm{brtablespoon}}{1\mathrm{brtablespoon}}*1.5\mathrm{centiliter}\to x\mathrm{centiliter}\approx 435.0\mathrm{centiliter}$
Conclusion: $290 brtablespoon ≈ 435.0 centiliter$
## Conversion in the opposite direction
The inverse of the conversion factor is that 1 centiliter is equal to 0.00229885057471264 times 290 UK tablespoons.
It can also be expressed as: 290 UK tablespoons is equal to $\frac{1}{\mathrm{0.00229885057471264}}$ centiliters.
## Approximation
An approximate numerical result would be: two hundred and ninety UK tablespoons is about four hundred and thirty-five centiliters, or alternatively, a centiliter is about zero times two hundred and ninety UK tablespoons.
## Footnotes
[1] The precision is 15 significant digits (fourteen digits to the right of the decimal point).
Results may contain small errors due to the use of floating point arithmetic. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 6, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7536624073982239, "perplexity": 2923.2334112943213}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487586390.4/warc/CC-MAIN-20210612193058-20210612223058-00027.warc.gz"} |
http://llvm.org/doxygen/EHStreamer_8h_source.html | LLVM 7.0.0svn
EHStreamer.h
Go to the documentation of this file.
1 //===- EHStreamer.h - Exception Handling Directive Streamer -----*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains support for writing exception info into assembly files.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_EHSTREAMER_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_EHSTREAMER_H
16
17 #include "AsmPrinterHandler.h"
19 #include "llvm/Support/Compiler.h"
20
21 namespace llvm {
22
23 class AsmPrinter;
25 class MachineInstr;
26 class MachineModuleInfo;
27 class MCSymbol;
28 template <typename T> class SmallVectorImpl;
29
30 /// Emits exception handling directives.
32 protected:
33 /// Target of directive emission.
35
36 /// Collected machine module information.
38
39 /// How many leading type ids two landing pads have in common.
40 static unsigned sharedTypeIDs(const LandingPadInfo *L,
42
43 /// Structure holding a try-range and the associated landing pad.
45 // The index of the landing pad.
47
48 // The index of the begin and end labels in the landing pad's label lists.
49 unsigned RangeIndex;
50 };
51
53
54 /// Structure describing an entry in the actions table.
55 struct ActionEntry {
56 int ValueForTypeID; // The value to write - may not be equal to the type id.
58 unsigned Previous;
59 };
60
61 /// Structure describing an entry in the call-site table.
62 struct CallSiteEntry {
63 // The 'try-range' is BeginLabel .. EndLabel.
64 MCSymbol *BeginLabel; // Null indicates the start of the function.
65 MCSymbol *EndLabel; // Null indicates the end of the function.
66
69
70 unsigned Action;
71 };
72
73 /// Compute the actions table and gather the first action index for each
75 void computeActionsTable(const SmallVectorImpl<const LandingPadInfo *> &LPs,
77 SmallVectorImpl<unsigned> &FirstActions);
78
81
82 /// Compute the call-site table. The entry for an invoke has a try-range
83 /// containing the call, a non-zero landing pad and an appropriate action.
84 /// The entry for an ordinary call has a try-range containing the call and
85 /// zero for the landing pad and the action. Calls marked 'nounwind' have
86 /// no entry and must not be contained in the try-range of any entry - they
87 /// form gaps in the table. Entries must be ordered by try-range address.
88 void computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
90 const SmallVectorImpl<unsigned> &FirstActions);
91
92 /// Emit landing pads and actions.
93 ///
94 /// The general organization of the table is complex, but the basic concepts
95 /// are easy. First there is a header which describes the location and
96 /// organization of the three components that follow.
97 /// 1. The landing pad site information describes the range of code covered
98 /// by the try. In our case it's an accumulation of the ranges covered
99 /// by the invokes in the try. There is also a reference to the landing
100 /// pad that handles the exception once processed. Finally an index into
101 /// the actions table.
102 /// 2. The action table, in our case, is composed of pairs of type ids
103 /// and next action offset. Starting with the action index from the
104 /// landing pad site, each type Id is checked for a match to the current
105 /// exception. If it matches then the exception and type id are passed
106 /// on to the landing pad. Otherwise the next action is looked up. This
107 /// chain is terminated with a next action of zero. If no type id is
108 /// found the frame is unwound and handling continues.
109 /// 3. Type id table contains references to all the C++ typeinfo for all
110 /// catches in the function. This tables is reversed indexed base 1.
111 void emitExceptionTable();
112
113 virtual void emitTypeInfos(unsigned TTypeEncoding, MCSymbol *TTBaseLabel);
114
115 // Helpers for identifying what kind of clause an EH typeid or selector
116 // corresponds to. Negative selectors are for filter clauses, the zero
117 // selector is for cleanups, and positive selectors are for catch clauses.
118 static bool isFilterEHSelector(int Selector) { return Selector < 0; }
119 static bool isCleanupEHSelector(int Selector) { return Selector == 0; }
120 static bool isCatchEHSelector(int Selector) { return Selector > 0; }
121
122 public:
124 ~EHStreamer() override;
125
126 // Unused.
127 void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {}
128 void beginInstruction(const MachineInstr *MI) override {}
129 void endInstruction() override {}
130
131 /// Return true' if this is a call to a function marked nounwind'. Return
132 /// `false' otherwise.
133 static bool callToNoUnwindFunction(const MachineInstr *MI);
134 };
135
136 } // end namespace llvm
137
138 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_EHSTREAMER_H
Structure describing an entry in the call-site table.
Definition: EHStreamer.h:62
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
#define LLVM_LIBRARY_VISIBILITY
LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked into a shared library...
Definition: Compiler.h:105
void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override
For symbols that have a size designated (e.g.
Definition: EHStreamer.h:127
Collects and handles AsmPrinter objects required to build debug or EH information.
Structure describing an entry in the actions table.
Definition: EHStreamer.h:55
static bool isFilterEHSelector(int Selector)
Definition: EHStreamer.h:118
Definition: EHStreamer.h:68
MachineModuleInfo * MMI
Collected machine module information.
Definition: EHStreamer.h:37
Emits exception handling directives.
Definition: EHStreamer.h:31
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
This structure is used to retain landing pad info for the current function.
void beginInstruction(const MachineInstr *MI) override
Process beginning of an instruction.
Definition: EHStreamer.h:128
static bool isCatchEHSelector(int Selector)
Definition: EHStreamer.h:120
static bool isCleanupEHSelector(int Selector)
Definition: EHStreamer.h:119
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:78
AsmPrinter * Asm
Target of directive emission.
Definition: EHStreamer.h:34
void endInstruction() override
Process end of an instruction.
Definition: EHStreamer.h:129
Representation of each machine instruction.
Definition: MachineInstr.h:60
constexpr char Size[] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.15878775715827942, "perplexity": 19273.822530545232}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125946077.4/warc/CC-MAIN-20180423144933-20180423164933-00578.warc.gz"} |
https://www.science.gov/topicpages/a/aerosol+particles+pbap.html | #### Sample records for aerosol particles pbap
1. Organic tracers of primary biological aerosol particles at subtropical Okinawa Island in the western North Pacific Rim
Zhu, Chunmao; Kawamura, Kimitaka; Kunwar, Bhagawati
2015-06-01
Primary biological aerosol particles (PBAPs) play an important role in affecting atmospheric physical and chemical properties. Aerosol samples were collected at Cape Hedo, Okinawa Island, Japan, from October 2009 to February 2012 and analyzed for five primary saccharides and four sugar alcohols as PBAP tracers. We detected high levels of sucrose in spring when blossoming of plants happens and prolifically emits pollen to the air. Concentrations of glucose, fructose, and trehalose showed levels higher than the other saccharides in spring in 2010. In comparison, primary saccharide levels were mutually comparable in spring, summer, and autumn in 2011, indicating the interannual variability of their local production in subtropical forests, which is driven by local temperature and radiation. High trehalose events were found to be associated with Asian dust outflows, indicating that Asian dust also contributes to PBAPs at Okinawa. Sugar alcohols peaked in summer and correlated with local precipitation and temperature, indicating high microbial activities. Positive matrix factorization analysis confirmed that the PBAPs are mainly derived from local vegetation, pollen, and fungal spores. A higher contribution of PBAP tracers to water-soluble organic carbon (WSOC) was found in summer (14.9%). The annual mean ambient loadings of fungal spores and PBAPs were estimated as 0.49 µg m-3 and 4.12 µg m-3, respectively, using the tracer method. We report, for the first time, year-round biomarkers of PBAP and soil dust and their contributions to WSOC in the subtropical outflow region of the Asian continent.
2. Biological aerosol particles as a key determinant of ice nuclei populations in a forest ecosystem
Tobo, Yutaka; Prenni, Anthony J.; DeMott, Paul J.; Huffman, J. Alex; McCluskey, Christina S.; Tian, Guoxun; Pöhlker, Christopher; Pöschl, Ulrich; Kreidenweis, Sonia M.
2013-09-01
primary biological aerosol particles (PBAPs) are known to have very high ice nucleating ability under mixed-phase cloud conditions. However, since the abundances of ice nucleation active PBAPs in the atmosphere are generally thought to be extremely small, their importance has remained uncertain. Here we present evidence for the role of PBAPs as atmospheric ice nuclei (IN) active at temperatures ranging from about -34°C to -9°C in a midlatitude ponderosa pine forest ecosystem in summertime. Our measurements show that the number concentrations of IN active at these temperatures were positively correlated with number concentrations of ambient fluorescent biological aerosol particles (FBAPs). Notably, the number concentrations of IN active at warmer temperatures increased quite rapidly in response to increases in the number concentrations of FBAPs. Moreover, we show that a newly-proposed parameterization related to the number concentrations of FBAPs can better reproduce the number concentrations of IN active over the entire temperature range examined, as compared with parameterizations related solely to the number concentrations of total aerosol particles with diameters larger than 0.5 µm as proposed previously. These results suggest that certain PBAPs released from forest biota can indeed play a key role in determining atmospheric IN populations in this ecosystem, especially at warmer temperatures, potentially leading to ice initiation in nearby mixed-phase clouds.
3. Fluorescent Biological Aerosol Particle Concentrations and Size Distributions Measured with an Ultraviolet Aerodynamic Particle Sizer (UV-APS) in Central Europe
Huffman, J. A.; Treutlein, B.; Pöschl, U.
2009-12-01
Primary biological aerosol particles (PBAPs), including bacteria, spores and pollen, are essential for the spread of organisms and disease in the biosphere, and numerous studies have suggested that they may be important for atmospheric processes, including the formation of clouds and precipitation. The atmospheric abundance and size distribution of PBAPs, however, are largely unknown. At a semi-urban site in Mainz, Germany, we used an ultraviolet aerodynamic particle sizer (UV-APS) to measure fluorescent biological aerosol particles (FBAPs), which can be regarded as viable bioaerosol particles representing a lower limit for the actual abundance of PBAPs. Fluorescence of non-biological aerosol components are likely to influence the measurement results obtained for fine particles (< 1 µm), but not for coarse particles (1 - 20 µm). Averaged over the four-month measurement period (August - December 2006), the mean number concentration of coarse FBAPs was ~3x10-2 cm-3, corresponding to ~4% of total coarse particle number [1]. The mean mass concentration of FBAPs was ~1 µg m-3, corresponding to ~20% of total coarse particle mass. The FBAP number size distributions exhibited alternating patterns with peaks at various diameters. A pronounced peak at ~3 µm was essentially always observed and can be described by the following campaign-average lognormal fit parameters: geometric mean diameter 3.2 µm, geometric standard deviation 1.3, number concentration 1.6 x 10-2 cm-3. This peak is likely due to fungal spores or agglomerated bacteria, and it exhibited a pronounced diel cycle with maximum intensity during early/mid-morning. FBAP peaks around ~1.5 µm, ~5 µm, and ~13 µm were also observed, but less pronounced and less frequent. These may be explained by single bacterial cells, larger fungal spores, and pollen grains, respectively. The observed number concentrations and characteristic sizes of FBAPs are consistent with microscopic, biological and chemical analyses of
4. Fluorescent biological aerosol particle concentrations and size distributions measured with an ultraviolet aerodynamic particle sizer (UV-APS) in Central Europe
Huffman, J. A.; Treutlein, B.; Pöschl, U.
2009-08-01
Primary biological aerosol particles (PBAPs), including bacteria, spores and pollen, are essential for the spread of organisms and disease in the biosphere, and numerous studies have suggested that they may be important for atmospheric processes, including the formation of clouds and precipitation. The atmospheric abundance and size distribution of PBAPs, however, are largely unknown. At a semi-urban site in Mainz, Germany, we used an ultraviolet aerodynamic particle sizer (UV-APS) to measure fluorescent biological aerosol particles (FBAPs), which can be regarded as viable bioaerosol particles representing a lower limit for the actual abundance of PBAPs. Fluorescence of non-biological aerosol components are likely to influence the measurement results obtained for fine particles (<1 μm), but not for coarse particles (1-20 μm). Averaged over the four-month measurement period (August-December 2006), the mean number concentration of coarse FBAPs was ~3×10-2 cm-3, corresponding to ~4% of total coarse particle number. The mean mass concentration of FBAPs was ~1 μg m-3, corresponding to ~20% of total coarse particle mass. The FBAP number size distributions exhibited alternating patterns with peaks at various diameters. A pronounced peak at ~3 μm was essentially always observed and can be described by the following campaign-average lognormal fit parameters: geometric mean diameter 3.2 μm, geometric standard deviation 1.3, number concentration 1.6×10-2 cm-3. This peak is likely due to fungal spores or agglomerated bacteria, and it exhibited a pronounced diel cycle with maximum intensity during early/mid-morning. FBAP peaks around ~1.5 μm, ~5 μm, and ~13 μm were also observed, but less pronounced and less frequent. These may be explained by single bacterial cells, larger fungal spores, and pollen grains, respectively. The observed number concentrations and characteristic sizes of FBAPs are consistent with microscopic, biological and chemical analyses of PBAPs in
5. Fluorescent biological aerosol particle concentrations and size distributions measured with an Ultraviolet Aerodynamic Particle Sizer (UV-APS) in Central Europe
Huffman, J. A.; Treutlein, B.; Pöschl, U.
2010-04-01
Primary Biological Aerosol Particles (PBAPs), including bacteria, spores and pollen, are essential for the spread of organisms and disease in the biosphere, and numerous studies have suggested that they may be important for atmospheric processes, including the formation of clouds and precipitation. The atmospheric abundance and size distribution of PBAPs, however, are largely unknown. At a semi-urban site in Mainz, Germany we used an Ultraviolet Aerodynamic Particle Sizer (UV-APS) to measure Fluorescent Biological Aerosol Particles (FBAPs), which provide an estimate of viable bioaerosol particles and can be regarded as an approximate lower limit for the actual abundance of PBAPs. Fluorescence of non-biological aerosol components are likely to influence the measurement results obtained for fine particles (<1 μm), but not for coarse particles (1-20 μm). Averaged over the four-month measurement period (August-December 2006), the mean number concentration of coarse FBAPs was ~3×10-2 cm-3, corresponding to ~4% of total coarse particle number. The mean mass concentration of FBAPs was ~1μg m-3, corresponding to ~20% of total coarse particle mass. The FBAP number size distributions exhibited alternating patterns with peaks at various diameters. A pronounced peak at ~3 μm was essentially always observed and can be described by the following campaign-average lognormal fit parameters: geometric mean diameter 3.2 μm, geometric standard deviation 1.3, number concentration 1.6×10-2 cm-3. This peak is likely due to fungal spores or agglomerated bacteria, and it exhibited a pronounced diel cycle (24-h) with maximum intensity during early/mid-morning. FBAP peaks around ~1.5 μm, ~5 μm, and ~13 μm were also observed, but less pronounced and less frequent. These may be single bacterial cells, larger fungal spores, and pollen grains, respectively. The observed number concentrations and characteristic sizes of FBAPs are consistent with microscopic, biological and chemical
6. Ambient measurements of biological aerosol particles near Killarney, Ireland: a comparison between real-time fluorescence and microscopy techniques
Healy, D. A.; Huffman, J. A.; O'Connor, D. J.; Pöhlker, C.; Pöschl, U.; Sodeau, J. R.
2014-08-01
Primary biological aerosol particles (PBAPs) can contribute significantly to the coarse particle burden in many environments. PBAPs can thus influence climate and precipitation systems as cloud nuclei and can spread disease to humans, animals, and plants. Measurement data and techniques for PBAPs in natural environments at high time- and size resolution are, however, sparse, and so large uncertainties remain in the role that biological particles play in the Earth system. In this study two commercial real-time fluorescence particle sensors and a Sporewatch single-stage particle impactor were operated continuously from 2 August to 2 September 2010 at a rural sampling location in Killarney National Park in southwestern Ireland. A cascade impactor was operated periodically to collect size-resolved particles during exemplary periods. Here we report the first ambient comparison of a waveband integrated bioaerosol sensor (WIBS-4) with a ultraviolet aerodynamic particle sizer (UV-APS) and also compare these real-time fluorescence techniques with results of fluorescence and optical microscopy of impacted samples. Both real-time instruments showed qualitatively similar behavior, with increased fluorescent bioparticle concentrations at night, when relative humidity was highest and temperature was lowest. The fluorescent particle number from the FL3 channel of the WIBS-4 and from the UV-APS were strongly correlated and dominated by a 3 μm mode in the particle size distribution. The WIBS FL2 channel exhibited particle modes at approx. 1 and 3 μm, and each was correlated with the concentration of fungal spores commonly observed in air samples collected at the site (ascospores, basidiospores, Ganoderma spp.). The WIBS FL1 channel exhibited variable multimodal distributions turning into a broad featureless single mode after averaging, and exhibited poor correlation with fungal spore concentrations, which may be due to the detection of bacterial and non-biological fluorescent
7. Transition metal associations with primary biological particles in sea spray aerosol generated in a wave channel.
PubMed
Guasco, Timothy L; Cuadra-Rodriguez, Luis A; Pedler, Byron E; Ault, Andrew P; Collins, Douglas B; Zhao, Defeng; Kim, Michelle J; Ruppel, Matthew J; Wilson, Scott C; Pomeroy, Robert S; Grassian, Vicki H; Azam, Farooq; Bertram, Timothy H; Prather, Kimberly A
2014-01-21
In the ocean, breaking waves generate air bubbles which burst at the surface and eject sea spray aerosol (SSA), consisting of sea salt, biogenic organic species, and primary biological aerosol particles (PBAP). Our overall understanding of atmospheric biological particles of marine origin remains poor. Here, we perform a control experiment, using an aerosol time-of-flight mass spectrometer to measure the mass spectral signatures of individual particles generated by bubbling a salt solution before and after addition of heterotrophic marine bacteria. Upon addition of bacteria, an immediate increase occurs in the fraction of individual particle mass spectra containing magnesium, organic nitrogen, and phosphate marker ions. These biological signatures are consistent with 21% of the supermicrometer SSA particles generated in a previous study using breaking waves in an ocean-atmosphere wave channel. Interestingly, the wave flume mass spectral signatures also contain metal ions including silver, iron, and chromium. The nascent SSA bioparticles produced in the wave channel are hypothesized to be as follows: (1) whole or fragmented bacterial cells which bioaccumulated metals and/or (2) bacteria-derived colloids or biofilms which adhered to the metals. This study highlights the potential for transition metals, in combination with specific biomarkers, to serve as unique indicators for the presence of marine PBAP, especially in metal-impacted coastal regions.
8. Ambient measurements of biological aerosol particles near Killarney, Ireland: a comparison between real-time fluorescence and microscopy techniques
Healy, D. A.; Huffman, J. A.; O'Connor, D. J.; Pöhlker, C.; Pöschl, U.; Sodeau, J. R.
2014-02-01
Primary biological aerosol particles (PBAP) can contribute significantly to the coarse particle burden in many environments, may thus influence climate and precipitation systems as cloud nuclei, and can spread disease to humans, animals, and plants. Measurements of PBAP in natural environments taken at high time- and size- resolution are, however, sparse and so large uncertainties remain in the role that biological particles play in the Earth system. In this study two commercial real-time fluorescence particle sensors and a Sporewatch single-stage particle impactor were operated continuously from 2 August to 2 September 2010 at a rural sampling location in Killarney National Park in south western Ireland. A cascade impactor was operated periodically to collect size-resolved particles during exemplary periods. Here we report the first ambient comparison of the waveband integrated bioaerosol sensor (WIBS-4) with the ultraviolet aerodynamic particle sizer (UV-APS) and also compare these real-time fluorescence techniques with results of fluorescence and optical microscopy of impacted samples. Both real-time instruments showed qualitatively similar behaviour, with increased fluorescent bioparticle concentrations at night when relative humidity was highest and temperature was lowest. The fluorescent particle number from the FL3 channel of the WIBS-4 and from the UV-APS were strongly correlated and dominated by a 3 μm mode in the particle size distribution. The WIBS FL2 channel exhibited particle modes at approx. 1 and 3 μm, and each were correlated with the concentration of fungal spores commonly observed in air samples collected at the site (ascospores, basidiospores, Ganoderma spp.). The WIBS FL1 channel exhibited variable multi-modal distributions turning into a broad featureless single mode after averaging and exhibited poor correlation with fungal spore concentrations, which may be due to the detection of bacterial and non-biological fluorescent particles
9. Composition and formation of organic aerosol particles in the Amazon
Pöhlker, C.; Wiedemann, K.; Sinha, B.; Shiraiwa, M.; Gunthe, S. S.; Artaxo, P.; Gilles, M. K.; Kilcoyne, A. L. D.; Moffet, R. C.; Smith, M.; Weigand, M.; Martin, S. T.; Pöschl, U.; Andreae, M. O.
2012-04-01
We applied scanning transmission X-ray microscopy with near edge X-ray absorption fine structure (STXM-NEXAFS) analysis to investigate the morphology and chemical composition of aerosol samples from a pristine tropical environment, the Amazon Basin. The samples were collected in the Amazonian rainforest during the rainy season and can be regarded as a natural background aerosol. The samples were found to be dominated by secondary organic aerosol (SOA) particles in the fine and primary biological aerosol particles (PBAP) in the coarse mode. Lab-generated SOA-samples from isoprene and terpene oxidation as well as pure organic compounds from spray-drying of aqueous solution were measured as reference samples. The aim of this study was to investigate the microphysical and chemical properties of a tropical background aerosol in the submicron size range and its internal mixing state. The lab-generated SOA and pure organic compounds occurred as spherical and mostly homogenous droplet-like particles, whereas the Amazonian SOA particles comprised a mixture of homogeneous droplets and droplets having internal structures due to atmospheric aging. In spite of the similar morphological appearance, the Amazon samples showed considerable differences in elemental and functional group composition. According to their NEXAFS spectra, three chemically distinct types of organic material were found and could be assigned to the following three categories: (1) particles with a pronounced carboxylic acid (COOH) peak similar to those of laboratory-generated SOA particles from terpene oxidation; (2) particles with a strong hydroxy (COH) signal similar to pure carbohydrate particles; and (3) particles with spectra resembling a mixture of the first two classes. In addition to the dominant organic component, the NEXAFS spectra revealed clearly resolved potassium (K) signals for all analyzed particles. During the rainy season and in the absence of anthropogenic influence, active biota is
10. Regional-scale simulations of fungal spore aerosols using an emission parameterization adapted to local measurements of fluorescent biological aerosol particles
Hummel, M.; Hoose, C.; Gallagher, M.; Healy, D. A.; Huffman, J. A.; O'Connor, D.; Pöschl, U.; Pöhlker, C.; Robinson, N. H.; Schnaiter, M.; Sodeau, J. R.; Toprak, E.; Vogel, H.
2014-04-01
Fungal spores as a prominent type of primary biological aerosol particles (PBAP) have been incorporated into the COSMO-ART regional atmospheric model, using and comparing three different emission parameterizations. Two literature-based emission rates derived from fungal spore colony counts and chemical tracer measurements were used as a parameterization baseline for this study. A third, new emission parameterization was adapted to field measurements of fluorescent biological aerosol particles (FBAP) from four locations across Northern Europe. FBAP concentrations can be regarded as a lower estimate of total PBAP concentrations. Size distributions of FBAP often show a distinct mode at approx. 3 μm, corresponding to a diameter range characteristic for many fungal spores. Previous studies have suggested the majority of FBAP in several locations are dominated by fungal spores. Thus, we suggest that simulated fungal spore concentrations obtained from the emission parameterizations can be compared to the sum of total FBAP concentrations. A comparison reveals that parameterized estimates of fungal spore concentrations based on literature numbers underestimate measured FBAP concentrations. In agreement with measurement data, the model results show a diurnal cycle in simulated fungal spore concentrations, which may develop partially as a consequence of a varying boundary layer height between day and night. Measured FBAP and simulated fungal spore concentrations also correlate similarly with simulated temperature and humidity. These meteorological variables, together with leaf area index, were chosen to drive the new emission parameterization discussed here. Using the new emission parameterization on a model domain covering Western Europe, fungal spores in the lowest model layer comprise a fraction of 15% of the total aerosol mass over land and reach average number concentrations of 26 L-1. The results confirm that fungal spores and biological particles may account for a
11. Nozzles for Focusing Aerosol Particles
DTIC Science & Technology
2009-10-01
control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE ( DD -MM-YYYY) October 2009 2. REPORT TYPE Final 3. DATES...Figures Figure 1. The design of the first-generation aerodynamic focusing nozzle for aerosol particles used for SPFS and TAOS instrument prototypes...Some nozzles were fabricated in aluminum and some in steel. It has been used for SPFS and TAOS measurement technologies both in the laboratory and
12. AEROSOL PARTICLE COLLECTOR DESIGN STUDY
SciTech Connect
Lee, S; Richard Dimenna, R
2007-09-27
A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.
13. Test-Aerosol Generator For Calibrating Particle Counters
NASA Technical Reports Server (NTRS)
Mogan, Paul A.; Adams, Alois J.; Schwindt, Christian J.; Hodge, Timothy R.; Mallow, Tim J.; Duong, Anh A.; Bukauskas, Vyto V.
1996-01-01
Apparatus generates clean, stable aerosol stream for use in testing and calibrating laser-based aerosol-particle counter. Size and concentration of aerosol particles controlled to ensure accurate calibration. Cheap, widely available medical nebulizers used to generate aerosols.
14. Regional-scale simulations of fungal spore aerosols using an emission parameterization adapted to local measurements of fluorescent biological aerosol particles
Hummel, M.; Hoose, C.; Gallagher, M.; Healy, D. A.; Huffman, J. A.; O'Connor, D.; Pöschl, U.; Pöhlker, C.; Robinson, N. H.; Schnaiter, M.; Sodeau, J. R.; Stengel, M.; Toprak, E.; Vogel, H.
2015-06-01
Fungal spores as a prominent type of primary biological aerosol particles (PBAP) have been incorporated into the COSMO-ART (Consortium for Small-scale Modelling-Aerosols and Reactive Trace gases) regional atmospheric model. Two literature-based emission rates for fungal spores derived from fungal spore colony counts and chemical tracer measurements were used as a parameterization baseline for this study. A third, new emission parameterization for fluorescent biological aerosol particles (FBAP) was adapted to field measurements from four locations across Europe. FBAP concentrations can be regarded as a lower estimate of total PBAP concentrations. Size distributions of FBAP often show a distinct mode at approx. 3 μm, corresponding to a diameter range characteristic for many fungal spores. Previous studies for several locations have suggested that FBAP are in many cases dominated by fungal spores. Thus, we suggest that simulated FBAP and fungal spore concentrations obtained from the three different emission parameterizations can be compared to FBAP measurements. The comparison reveals that simulated fungal spore concentrations based on literature emission parameterizations are lower than measured FBAP concentrations. In agreement with the measurements, the model results show a diurnal cycle in simulated fungal spore concentrations, which may develop partially as a consequence of a varying boundary layer height between day and night. Temperature and specific humidity, together with leaf area index (LAI), were chosen to drive the new emission parameterization which is fitted to the FBAP observations. The new parameterization results in similar root mean square errors (RMSEs) and correlation coefficients compared to the FBAP observations as the previously existing fungal spore emission parameterizations, with some improvements in the bias. Using the new emission parameterization on a model domain covering western Europe, FBAP in the lowest model layer comprise a
15. Concentrations, size distributions and temporal variations of fluorescent biological aerosol particles in southern tropical India
Valsan, Aswathy; Krishna R, Ravi; CV, Biju; Huffman, Alex; Poschl, Ulrich; Gunthe, Sachin
2015-04-01
Biological aerosols constitute a wide range of dead and alive biological materials and structures that are suspended in the atmosphere. They play an important role in the atmospheric physical, chemical and biological processes and health of living being by spread of diseases among humans, plants, and, animals. The atmospheric abundance, sources, physical properties of PBAPs as compared to non-biological aerosols, however, is poorly characterized. The Indian tropical region, where large fraction of the world's total population is residing, experiences a distinctive meteorological phenomenon by means of Indian Summer Monsoon (IMS). Thus, the properties and characteristics of biological aerosols are also expected to be very diverse over the Indian subcontinent depending upon the seasons. Here we characterize the number concentration and size distribution of Fluorescent Biological Aerosol Particles (FBAP) at a high altitude continental site, Munnar (10.09 N, 77.06 E; 1605 m asl) in South India during the South-West monsoon, which constitute around 80 percent of the annual rainfall in Munnar. Continuous three months measurements (from 01 June 2014 to 21 Aug 2104) FBAPs were carried out at Munnar using Ultra Violet Aerodynamic Particle Sizer (UVAPS) during IMS. The mean number and mass concentration of coarse FBAP averaged over the entire campaign was 1.7 x 10-2 cm-3 and 0.24 µg m-3 respectively, which corresponds to 2 percent and 6 percent of total aerosol particle number and mass concentration. In agreement to other previous measurements the number size distribution of FBAP also peaks at 3.2 micron indicating the strong presence of fungal spores. This was also supported by the Scanning Electron Microscopic analysis of bioaerosols on filter paper. They also displayed a strong diurnal cycle with maximum concentration occurring at early morning hours. During periods of heavy and continuous rain where the wind is consistently blowing from South-West direction it was
16. The Life Cycle of Stratospheric Aerosol Particles
NASA Technical Reports Server (NTRS)
Hamill, Patrick; Jensen, Eric J.; Russell, P. B.; Bauman, Jill J.
1997-01-01
This paper describes the life cycle of the background (nonvolcanic) stratospheric sulfate aerosol. The authors assume the particles are formed by homogeneous nucleation near the tropical tropopause and are carried aloft into the stratosphere. The particles remain in the Tropics for most of their life, and during this period of time a size distribution is developed by a combination of coagulation, growth by heteromolecular condensation, and mixing with air parcels containing preexisting sulfate particles. The aerosol eventually migrates to higher latitudes and descends across isentropic surfaces to the lower stratosphere. The aerosol is removed from the stratosphere primarily at mid- and high latitudes through various processes, mainly by isentropic transport across the tropopause from the stratosphere into the troposphere.
17. Electronic cigarette aerosol particle size distribution measurements.
PubMed
Ingebrethsen, Bradley J; Cole, Stephen K; Alderman, Steven L
2012-12-01
The particle size distribution of aerosols produced by electronic cigarettes was measured in an undiluted state by a spectral transmission procedure and after high dilution with an electrical mobility analyzer. The undiluted e-cigarette aerosols were found to have particle diameters of average mass in the 250-450 nm range and particle number concentrations in the 10(9) particles/cm(3) range. These measurements are comparable to those observed for tobacco burning cigarette smoke in prior studies and also measured in the current study with the spectral transmission method and with the electrical mobility procedure. Total particulate mass for the e-cigarettes calculated from the size distribution parameters measured by spectral transmission were in good agreement with replicate determinations of total particulate mass by gravimetric filter collection. In contrast, average particle diameters determined for e-cigarettes by the electrical mobility method are in the 50 nm range and total particulate masses calculated based on the suggested diameters are orders of magnitude smaller than those determined gravimetrically. This latter discrepancy, and the very small particle diameters observed, are believed to result from almost complete e-cigarette aerosol particle evaporation at the dilution levels and conditions of the electrical mobility analysis. A much smaller degree, ~20% by mass, of apparent particle evaporation was observed for tobacco burning cigarette smoke. The spectral transmission method is validated in the current study against measurements on tobacco burning cigarette smoke, which has been well characterized in prior studies, and is supported as yielding an accurate characterization of the e-cigarette aerosol particle size distribution.
18. Characterizing Biological Particles in the Atmosphere at two Sites in Colorado
Garcia, E.; Prenni, A. J.; Prenni, J.; Rivest, J.; Demott, P. J.; Kreidenweis, S. M.
2010-12-01
The composition and distribution of primary biological aerosol particles (PBAPs) in the atmosphere is constantly changing due to both natural and anthropogenic activities. In this presentation, we will describe measurements aimed at better characterizing this population at Manitou Experimental Forest, in Pike National Forest in Colorado and in Fort Collins, CO. This work is part of the larger Biosphere-atmosphere Exchange of Aerosols within Cloud, Carbon and Hydrologic cycles, including Organics and Nitrogen (BEACHON) field study program, which is aimed at studying the connections between the biogeochemical cycling of carbon and water in semi-arid regions of the Western U.S. To this end, we are collecting PBAP with SKC impingers into water, which are subsequently analyzed by flow cytometery to determine the atmospheric biological particle concentration. Further, we are generating a gene library of the small subunit RNA genes to speciate the PBAPs in our collected samples using Sanger sequencing. These experiments are performed throughout the year to better understand seasonal variability of atmospheric microbial communities at the selected sites. A small handful of PBAPs have been found to be some of the best ice nucleators in the atmosphere, inducing ice nucleation as high as -2oC; these particles may play pivotal roles in influencing ice formation in cold clouds and, thereby, climate. Preliminary data will be presented aimed at better characterizing this important subset of biological particles.
19. Fungal spores overwhelm biogenic organic aerosols in a midlatitudinal forest
Zhu, Chunmao; Kawamura, Kimitaka; Fukuda, Yasuro; Mochida, Michihiro; Iwamoto, Yoko
2016-06-01
Both primary biological aerosol particles (PBAPs) and oxidation products of biogenic volatile organic compounds (BVOCs) contribute significantly to organic aerosols (OAs) in forested regions. However, little is known about their relative importance in diurnal timescales. Here, we report biomarkers of PBAP and secondary organic aerosols (SOAs) for their diurnal variability in a temperate coniferous forest in Wakayama, Japan. Tracers of fungal spores, trehalose, arabitol and mannitol, showed significantly higher levels in nighttime than daytime (p < 0.05), resulting from the nocturnal sporulation under near-saturated relative humidity. On the contrary, BVOC oxidation products showed higher levels in daytime than nighttime, indicating substantial photochemical SOA formation. Using tracer-based methods, we estimated that fungal spores account for 45 % of organic carbon (OC) in nighttime and 22 % in daytime, whereas BVOC oxidation products account for 15 and 19 %, respectively. To our knowledge, we present for the first time highly time-resolved results that fungal spores overwhelmed BVOC oxidation products in contributing to OA especially in nighttime. This study emphasizes the importance of both PBAPs and SOAs in forming forest organic aerosols.
20. Vapor scavenging by atmospheric aerosol particles
SciTech Connect
Andrews, E.
1996-05-01
Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particles hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.
1. The hygroscopicity of indoor aerosol particles
SciTech Connect
Wei, L.
1993-07-01
A system to study the hygroscopic growth of particle was developed by combining a Tandem Differential Mobility Analyzer (TDMA) with a wetted wall reactor. This system is capable of mimicking the conditions in human respiratory tract, and measuring the particle size change due to the hygroscopic growth. The performance of the system was tested with three kinds of particles of known composition, NaCl, (NH{sub 4}){sub 2}SO{sub 4}, and (NH{sub 4})HS0{sub 4} particles. The hygroscopicity of a variety of common indoor aerosol particles was studied including combustion aerosols (cigarette smoking, cooking, incenses and candles) and consumer spray products such as glass cleaner, general purpose cleaner, hair spray, furniture polish spray, disinfectant, and insect killer. Experiments indicate that most of the indoor aerosols show some hygroscopic growth and only a few materials do not. The magnitude of hygroscopic growth ranges from 20% to 300% depending on the particle size and fraction of water soluble components.
2. Fatty Acids as Surfactants on Aerosol Particles
Tervahattu, H.; Juhanoja, J.; Niemi, J.
2003-12-01
Fatty acids (n-alcanoic acids) are common compounds in numerous anthropogenic and natural emissions. According to Rogge et al. (1993), catalyst-equipped automobiles emitted more than 600 μg km-1 of fatty acids which was over 50% of all identified organics in fine aerosol emissions. Coal burning produces fatty acids ranging from about 1700 mg kg-1 for bituminous coal to over 10000 mg kg-1 for lignite (Oros and Simoneit, 2000). Similarly, biomass burning is an important source for aerosol fatty acids. They are the major identified compound group in deciduous tree smoke, their total emission factor being measured as 1589 mg kg-1 which was 56% of all identified organic compounds (Oros and Simoneit, 2001a). Large amounts of fatty acid are also emitted from burning of conifer trees and grass (Oros and Simoneit, 2001a; Simoneit, 2002). Fatty acids have been reported to be major constituents of marine aerosols in many investigations (Barger and Garrett, 1976; Gagosian et. al, 1981; Sicre et al., 1990; Stephanou, 1992). It has been suggested that as the marine aerosol particles form, they acquire a coating of organic surfactants (Blanchard, 1964; Gill et al., 1983; Middlebrook et al., 1998; Ellison et al., 1999). Amphiphilic molecules, including lipids, can be assembled as monomolecular layers at air/water interfaces as well as transported to a solid support. Recently, we could show by time-of-flight secondary ion mass spectrometry that fatty acids are important ingredients of the outermost surface layer of the sea-salt aerosol particles (Tervahattu et al., 2002). In their TOF-SIMS studies on the surface composition of atmospheric aerosols, Peterson and Tyler (2002) found fatty acids on the surface of Montana forest fire particles. In this work we have studied by TOF-SIMS the surface chemical composition of aerosol particles emitted from field fires in the Baltic and other East European countries and transported to Finland as well as aerosol particles transported from
3. Particle size distribution of indoor aerosol sources
SciTech Connect
Shah, K.B.
1990-10-24
As concern about Indoor Air Quality (IAQ) has grown in recent years, it has become necessary to determine the nature of particles produced by different indoor aerosol sources and the typical concentration that these sources tend to produce. These data are important in predicting the dose of particles to people exposed to these sources and it will also enable us to take effective mitigation procedures. Further, it will also help in designing appropriate air cleaners. A new state of the art technique, DMPS (Differential Mobility Particle Sizer) System is used to determine the particle size distributions of a number of sources. This system employs the electrical mobility characteristics of these particles and is very effective in the 0.01--1.0 {mu}m size range. A modified system that can measure particle sizes in the lower size range down to 3 nm was also used. Experimental results for various aerosol sources is presented in the ensuing chapters. 37 refs., 20 figs., 2 tabs.
4. Differentiation of hydrophobic from hydrophilic submicrometer aerosol particles
SciTech Connect
Juozaitis, A.; Ulevicius, V.; Girgzdys, A. ); Willeke, K. )
1993-02-01
A method has been developed that differentiates hydrophobic from hydrophilic submicrometer aerosol particles in air environments containing polydisperse aerosols composed of different chemical species. First, a narrow particle size range is extracted from the polydisperse aerosol by an electrostatic aerosol classifier. Then the monodisperse aerosols of different origins are exposed to preselected supersaturation levels and are size-classified again by a second electrostatic classifier. Hydrophobic aerosol particles pass through the second classifier when its size window matches that of the first classifier. Hydrophilic aerosol particles grow to a larger size and are removed by the second classifier. The method has been applied in the field by measuring the fraction of hydrophobic atmospheric particles in a suburb of Vilnius, Lithuania, during a period of high emission of hydrophobic soot particles from residential coal and industrial oil burning in winter. 33 refs., 4 figs.
5. Spatial Variability of CCN Sized Aerosol Particles
Asmi, A.; Väänänen, R.
2014-12-01
The computational limitations restrict the grid size used in GCM models, and for many cloud types they are too large when compared to the scale of the cloud formation processes. Several parameterizations for e.g. convective cloud formation exist, but information on spatial subgrid variation of the cloud condensation nuclei (CCNs) sized aerosol concentration is not known. We quantify this variation as a function of the spatial scale by using datasets from airborne aerosol measurement campaigns around the world including EUCAARI LONGREX, ATAR, INCA, INDOEX, CLAIRE, PEGASOS and several regional airborne campaigns in Finland. The typical shapes of the distributions are analyzed. When possible, we use information obtained by CCN counters. In some other cases, we use particle size distribution measured by for example SMPS to get approximated CCN concentration. Other instruments used include optical particle counters or condensational particle counters. When using the GCM models, the CCN concentration used for each the grid-box is often considered to be either flat, or as an arithmetic mean of the concentration inside the grid-box. However, the aircraft data shows that the concentration values are often lognormal distributed. This, combined with the subgrid variations in the land use and atmospheric properties, might cause that the aerosol-cloud interactions calculated by using mean values to vary significantly from the true effects both temporary and spatially. This, in turn, can cause non-linear bias into the GCMs. We calculate the CCN aerosol concentration distribution as a function of different spatial scales. The measurements allow us to study the variation of these distributions within from hundreds of meters up to hundreds of kilometers. This is used to quantify the potential error when mean values are used in GCMs.
6. The Impact of Aerosol Particle Mixing State on the Hygroscopicity of Sea Spray Aerosol.
PubMed
Schill, Steven R; Collins, Douglas B; Lee, Christopher; Morris, Holly S; Novak, Gordon A; Prather, Kimberly A; Quinn, Patricia K; Sultana, Camille M; Tivanski, Alexei V; Zimmermann, Kathryn; Cappa, Christopher D; Bertram, Timothy H
2015-06-24
Aerosol particles influence global climate by determining cloud droplet number concentrations, brightness, and lifetime. Primary aerosol particles, such as those produced from breaking waves in the ocean, display large particle-particle variability in chemical composition, morphology, and physical phase state, all of which affect the ability of individual particles to accommodate water and grow into cloud droplets. Despite such diversity in molecular composition, there is a paucity of methods available to assess how particle-particle variability in chemistry translates to corresponding differences in aerosol hygroscopicity. Here, an approach has been developed that allows for characterization of the distribution of aerosol hygroscopicity within a chemically complex population of atmospheric particles. This methodology, when applied to the interpretation of nascent sea spray aerosol, provides a quantitative framework for connecting results obtained using molecular mimics generated in the laboratory with chemically complex ambient aerosol. We show that nascent sea spray aerosol, generated in situ in the Atlantic Ocean, displays a broad distribution of particle hygroscopicities, indicative of a correspondingly broad distribution of particle chemical compositions. Molecular mimics of sea spray aerosol organic material were used in the laboratory to assess the volume fractions and molecular functionality required to suppress sea spray aerosol hygroscopicity to the extent indicated by field observations. We show that proper accounting for the distribution and diversity in particle hygroscopicity and composition are important to the assessment of particle impacts on clouds and global climate.
7. Phase transition behaviour of sodium oleate aerosol particles
Nájera, Juan J.
Field measurements have shown that organic surfactants are significant components of atmospheric aerosols. While fatty acids, among other surfactants, are prevalent in the atmosphere, the influence of these species on the chemical and physical properties of atmospheric aerosols remains not fully characterized. In order to assess the phase in which particles may exist, a detailed study of the deliquescence of a model surfactant aerosol has been carried out. Sodium oleate was chosen as a surfactant proxy relevant in atmospheric aerosol. Sodium oleate micelle aerosol particles were generated nebulizing a sodium oleate aqueous solution. In this study, the water uptake and phase transition of sodium oleate aerosol particles have been studied in a room temperature aerosol flow tube system (AFT) using Fourier transform infrared (FTIR) spectroscopy. Aerosol morphology and elemental composition were also analysed using scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) techniques. The particles are homogeneously distributed as ellipsoidal-shape aggregates of micelles particles with an average size of ˜1.1 μm. The deliquescence by the sodium oleate aerosol particles was monitored by infrared extinction spectroscopy, where the dried aerosol particles were exposed to increasing relative humidity as they passed through the AFT. Observations of the infrared absorption features of condensed phase liquid water enable to determine the sodium oleate deliquescence phase transition at 88±2%.
8. Workplace aerosol mass concentration measurement using optical particle counters.
PubMed
Görner, Peter; Simon, Xavier; Bémer, Denis; Lidén, Göran
2012-02-01
Direct-reading aerosol measurement usually uses the optical properties of airborne particles to detect and measure particle concentration. In the case of occupational hygiene, mass concentration measurement is often required. Two aerosol monitoring methods are based on the principle of light scattering: optical particle counting (OPC) and photometry. The former analyses the light scattered by a single particle, the latter by a cloud of particles. Both methods need calibration to transform the quantity of scattered light detected into particle concentration. Photometers are simpler to use and can be directly calibrated to measure mass concentration. However, their response varies not only with aerosol concentration but also with particle size distribution, which frequently contributes to biased measurement. Optical particle counters directly measure the particle number concentration and particle size that allows assessment of the particle mass provided the particles are spherical and of known density. An integrating algorithm is used to calculate the mass concentration of any conventional health-related aerosol fraction. The concentrations calculated thus have been compared with simultaneous measurements by conventional gravimetric sampling to check the possibility of field OPC calibration with real workplace aerosols with a view to further monitoring particle mass concentration. Aerosol concentrations were measured in the food industry using the OPC GRIMM® 1.108 and the CIP 10-Inhalable and CIP 10-Respirable (ARELCO®) aerosol samplers while meat sausages were being brushed and coated with calcium carbonate. Previously, the original OPC inlet had been adapted to sample inhalable aerosol. A mixed aerosol of calcium carbonate and fungi spores was present in the workplace. The OPC particle-size distribution and an estimated average particle density of both aerosol components were used to calculate the mass concentration. The inhalable and respirable aerosol fractions
9. Initial size distributions and hygroscopicity of indoor combustion aerosol particles
SciTech Connect
Li, W.; Hopke, P.K.
1993-10-01
Cigarette smoke, incense smoke, natural gas flames, propane fuel flames, and candle flames are contributors of indoor aerosol particles. To provide a quantitative basis for the modeling of inhaled aerosol deposition pattern, the hygroscopic growth of particles from these five sources as well as the source size distributions were measured. Because the experiments were performed on the bases of particles of single size, it provided not only the averaged particles hygroscopic growth of each source, but also the detailed size change for particles of different sizes within the whole size spectrum. The source particle size distribution measurements found that cigarette smoke and incense smoke contained particles in the size range of 100-700 nm, while the natural gas, propane, and candle flames generated particles between 10 and 100 nm. The hygroscopic growth experiments showed that these combustion aerosol particles could grow 10% to 120%, depending on the particle sizes and origins. 18 refs., 15 figs., 3 tabs.
10. Autofluorescence of atmospheric bioaerosols - fluorescent biomolecules, biological standard particles and potential interferences
Pöhlker, C.; Huffmann, J. A.; Pöschl, U.
2012-04-01
Primary biological aerosol particles (PBAP) such as pollen, fungal spores, bacteria, biogenic polymers and debris from larger organisms are known to influence atmospheric chemistry and physics, the biosphere and public health. PBAP account for up to ~30% of fine and up to ~70% of coarse particulate matter in urban, rural and pristine environment and are released with estimated emission rates of up to ~1000 Tg/a [1]. Continuous measurements of the abundance, variability and diversity of PBAP have been difficult until recently, however. The application of on-line instruments able to detect autofluorescence from biological particles in real-time has been a promising development for the measurement of PBAP concentrations and fluxes in different environments [2,3]. The detected fluorescent biological aerosol particles (FBAP) can be regarded as a subset of PBAP, although the exact relationship between PBAP and FBAP is still being investigated. Autofluorescence of FBAP is usually a superposition of fluorescence from a mixture of individual fluorescent molecules (fluorophores). Numerous biogenic fluorophores such as amino acids (e.g., tryptophan, tyrosine), coenzymes (e.g., NAD(P)H, riboflavin) and biopolymers (e.g., cellulose) emit fluorescent light due to heterocyclic aromatic rings or conjugated double bonds within their molecular structures. The tryptophan emission peak is a common feature of most bioparticles because the amino acid is a constituent of many proteins and peptides. The influence of the coenzymes NAD(P)H and riboflavin on the autofluorescence of bacteria can be regarded as an indicator for bacterial metabolism and has been utilized to discriminate between viable and non-viable organisms [4]. However, very little information is available about other essential biofluorophores in fungal spores and pollen. In order to better understand the autofluorescence behavior of FBAP, we have used fluorescence spectroscopy and fluorescence microscopy to analyze standard
11. Particle size distributions of several commonly used seeding aerosols
NASA Technical Reports Server (NTRS)
Crosswy, F. L.
1985-01-01
During the course of experimentation, no solid particle powder could be found which produced an aerosol with a narrow particle size distribution when fluidization was the only flow process used in producing the aerosol. The complication of adding particle size fractionation processes to the aerosol generation effort appears to be avoidable. In this regard, a simple sonic orifice is found to be effective in reducing the percentage of agglomerates in the several metal oxide powders tested. Marginally beneficial results are obtained for a 0.5/99.5 percent by weight mixture of the flow agent and metal oxide powder. However, agglomeration is observed to be enhanced when the flow agent percentage is increased to 5 percent. Liquid atomization using the Collison nebulizer as well as a version of the Laskin nozzle resulted in polydispersed aerosols with particle size distributions heavily weighted by the small particle end of the size spectrum. The aerosol particle size distributions produced by the vaporization/condensation seeder are closer to the ideal monodispersed aerosol than any of the other aerosols tested. In addition, this seeding approach affords a measure of control over particle size and particle production rate.
12. Laser velocimeter seed particle sizing by the whisker particle collector and laser aerosol spectrometer methods
Crosswy, F. L.; Kingery, M. K.; Schaefer, H. J.; Pfeifer, H. J.
1989-07-01
Two different aerosol particle sizing systems, the Whisker Particle Collector (WPC) and the Laser Aerosol Spectrometer (LAS), were evaluated for sizing aerosol particles in the size range of 0.1 to 3.0 micrometers. The evaluation tests were conducted using an aerosol of alumina (Al2O3) particles, an aerosol commonly used to provide light scattering particles for laser velocimeter measurements in high temperature flows. The LAS and WPC measurements were then compared for samples taken from the alumina particle aerosols. Some difficulty was encountered in directly comparing these measurements. Other operational aspects of the two systems were also compared including on-line/off-line data presentation capabilities, field portability and measurement limitations at the small particle end of the size range of interest.
13. Microphysical processing of aerosol particles in orographic clouds
Pousse-Nottelmann, S.; Zubler, E. M.; Lohmann, U.
2015-01-01
An explicit and detailed treatment of cloud-borne particles allowing for the consideration of aerosol cycling in clouds has been implemented in the regional weather forecast and climate model COSMO. The effects of aerosol scavenging, cloud microphysical processing and regeneration upon cloud evaporation on the aerosol population and on subsequent cloud formation are investigated. For this, two-dimensional idealized simulations of moist flow over two bell-shaped mountains were carried out varying the treatment of aerosol scavenging and regeneration processes for a warm-phase and a mixed-phase orographic cloud. The results allowed to identify different aerosol cycling mechanisms. In the simulated non-precipitating warm-phase cloud, aerosol mass is incorporated into cloud droplets by activation scavenging and released back to the atmosphere upon cloud droplet evaporation. In the mixed-phase cloud, a first cycle comprises cloud droplet activation and evaporation via the Wegener-Bergeron-Findeisen process. A second cycle includes below-cloud scavenging by precipitating snow particles and snow sublimation and is connected to the first cycle via the riming process which transfers aerosol mass from cloud droplets to snow flakes. In the simulated mixed-phase cloud, only a negligible part of the total aerosol mass is incorporated into ice crystals. Sedimenting snow flakes reaching the surface remove aerosol mass from the atmosphere. The results show that aerosol processing and regeneration lead to a vertical redistribution of aerosol mass and number. However, the processes not only impact the total aerosol number and mass, but also the shape of the aerosol size distributions by enhancing the internally mixed/soluble accumulation mode and generating coarse mode particles. Concerning subsequent cloud formation at the second mountain, accounting for aerosol processing and regeneration increases the cloud droplet number concentration with possible implications for the ice
14. Microphysical processing of aerosol particles in orographic clouds
Pousse-Nottelmann, S.; Zubler, E. M.; Lohmann, U.
2015-08-01
An explicit and detailed treatment of cloud-borne particles allowing for the consideration of aerosol cycling in clouds has been implemented into COSMO-Model, the regional weather forecast and climate model of the Consortium for Small-scale Modeling (COSMO). The effects of aerosol scavenging, cloud microphysical processing and regeneration upon cloud evaporation on the aerosol population and on subsequent cloud formation are investigated. For this, two-dimensional idealized simulations of moist flow over two bell-shaped mountains were carried out varying the treatment of aerosol scavenging and regeneration processes for a warm-phase and a mixed-phase orographic cloud. The results allowed us to identify different aerosol cycling mechanisms. In the simulated non-precipitating warm-phase cloud, aerosol mass is incorporated into cloud droplets by activation scavenging and released back to the atmosphere upon cloud droplet evaporation. In the mixed-phase cloud, a first cycle comprises cloud droplet activation and evaporation via the Wegener-Bergeron-Findeisen (WBF) process. A second cycle includes below-cloud scavenging by precipitating snow particles and snow sublimation and is connected to the first cycle via the riming process which transfers aerosol mass from cloud droplets to snowflakes. In the simulated mixed-phase cloud, only a negligible part of the total aerosol mass is incorporated into ice crystals. Sedimenting snowflakes reaching the surface remove aerosol mass from the atmosphere. The results show that aerosol processing and regeneration lead to a vertical redistribution of aerosol mass and number. Thereby, the processes impact the total aerosol number and mass and additionally alter the shape of the aerosol size distributions by enhancing the internally mixed/soluble Aitken and accumulation mode and generating coarse-mode particles. Concerning subsequent cloud formation at the second mountain, accounting for aerosol processing and regeneration increases
15. Fluorescent biological aerosol particle measurements at a tropical high-altitude site in southern India during the southwest monsoon season
Valsan, A. E.; Ravikrishna, R.; Biju, C. V.; Pöhlker, C.; Després, V. R.; Huffman, J. A.; Pöschl, U.; Gunthe, S. S.
2016-08-01
fact that the ratio of PBAPs to TAP is strongly dependent on particle size and location and thus may constitute a significant proportion of total aerosol particles.
16. Optimized sparse-particle aerosol representations for modeling cloud-aerosol interactions
Fierce, Laura; McGraw, Robert
2016-04-01
Sparse representations of atmospheric aerosols are needed for efficient regional- and global-scale chemical transport models. Here we introduce a new framework for representing aerosol distributions, based on the method of moments. Given a set of moment constraints, we show how linear programming can be used to identify collections of sparse particles that approximately maximize distributional entropy. The collections of sparse particles derived from this approach reproduce CCN activity of the exact model aerosol distributions with high accuracy. Additionally, the linear programming techniques described in this study can be used to bound key aerosol properties, such as the number concentration of CCN. Unlike the commonly used sparse representations, such as modal and sectional schemes, the maximum-entropy moment-based approach is not constrained to pre-determined size bins or assumed distribution shapes. This study is a first step toward a new aerosol simulation scheme that will track multivariate aerosol distributions with sufficient computational efficiency for large-scale simulations.
17. Laboratory Experiments and Instrument Intercomparison Studies of Carbonaceous Aerosol Particles
SciTech Connect
Davidovits, Paul
2015-10-20
Aerosols containing black carbon (and some specific types of organic particulate matter) directly absorb incoming light, heating the atmosphere. In addition, all aerosol particles backscatter solar light, leading to a net-cooling effect. Indirect effects involve hydrophilic aerosols, which serve as cloud condensation nuclei (CCN) that affect cloud cover and cloud stability, impacting both atmospheric radiation balance and precipitation patterns. At night, all clouds produce local warming, but overall clouds exert a net-cooling effect on the Earth. The effect of aerosol radiative forcing on climate may be as large as that of the greenhouse gases, but predominantly opposite in sign and much more uncertain. The uncertainties in the representation of aerosol interactions in climate models makes it problematic to use model projections to guide energy policy. The objective of our program is to reduce the uncertainties in the aerosol radiative forcing in the two areas highlighted in the ASR Science and Program Plan. That is, (1) addressing the direct effect by correlating particle chemistry and morphology with particle optical properties (i.e. absorption, scattering, extinction), and (2) addressing the indirect effect by correlating particle hygroscopicity and CCN activity with particle size, chemistry, and morphology. In this connection we are systematically studying particle formation, oxidation, and the effects of particle coating. The work is specifically focused on carbonaceous particles where the uncertainties in the climate relevant properties are the highest. The ongoing work consists of laboratory experiments and related instrument inter-comparison studies both coordinated with field and modeling studies, with the aim of providing reliable data to represent aerosol processes in climate models. The work is performed in the aerosol laboratory at Boston College. At the center of our laboratory setup are two main sources for the production of aerosol particles: (a
18. A conceptual framework for mixing structures in individual aerosol particles
Li, Weijun; Sun, Jiaxing; Xu, Liang; Shi, Zongbo; Riemer, Nicole; Sun, Yele; Fu, Pingqing; Zhang, Jianchao; Lin, Yangting; Wang, Xinfeng; Shao, Longyi; Chen, Jianmin; Zhang, Xiaoye; Wang, Zifa; Wang, Wenxing
2016-11-01
This study investigated the particle size- and age-dependent mixing structures of individual particles in clean and polluted air. Aerosols were classified into eight components: sea salt, mineral dust, fly ash, metal, soot, sulfates, nitrates, and organic matter (OM). Based on our aerosol classification, a particle that consists of two or more aerosol components can be defined as an internally mixed particle. Otherwise, it is considered to be an externally mixed particle. Within the internally mixed particle class, we identified four heterogeneous mixing structures: core-shell, dumbbell, OM coating, and dispersed OM, as well as one homogeneous-like mixing structure. Homogeneous-like mixing mainly occurred in fine particles (<1 µm), while the frequency of heterogeneously mixed particles increased with particle size. Our study demonstrated that particle mixing structures depend on particle size and location and evolve with time. OM-coating and core-shell structures are important indicators for particle aging in air as long as they are distant from specific emission sources. Long-range transported particles tended to have core-shell and OM-coating structures. We found that secondary aerosol components (e.g., sulfates, nitrates, and organics) determined particle mixing structures, because their phases change following particle hydration and dehydration under different relative humidities. Once externally mixed particles are transformed into internally mixed particles, they cannot revert to their former state, except when semivolatile aerosol components are involved. Categorizing mixing structures of individual particles is essential for studying their optical and hygroscopic properties and for tracing the development of their physical or chemical properties over time.
19. The optical manipulation and characterisation of aerosol particles
Reid, Jonathan P.
2008-08-01
Aerosols play a crucial role in many areas of science, ranging from atmospheric chemistry and physics, to pharmaceutical aerosols and drug delivery to the lungs, to combustion science and spray drying. The development of new methods for characterising the properties and dynamics of aerosol particles is of crucial importance if the complex role that particles play is to be more fully understood. Optical tweezers provide a valuable new tool to address fundamental questions in aerosol science. Single or multiple particles 1-15 μm in diameter can be manipulated for indefinite timescales. Linear and non-linear Raman and fluorescence spectroscopies can be used to probe particle composition, phase, component mixing state, and size. In particular, size can be determined with nanometre accuracy, allowing accurate measurements of the thermodynamic properties of aerosols, the kinetics of particle transformation and of light absorption. Further, the simultaneous manipulation of multiple particles in parallel optical traps provides a method for performing comparative measurements on particles of different composition. We will present some latest work in which optical tweezers are used to characterise aerosol dynamics, demonstrating that optical tweezers can find application in studies of hygroscopicity, the mixing state of different chemical components, including the phase separation of immiscible phases, and the kinetics of chemical transformation.
20. Equilibrium absorptive partitioning theory between multiple aerosol particle modes
Crooks, Matthew; Connolly, Paul; Topping, David; McFiggans, Gordon
2016-10-01
An existing equilibrium absorptive partitioning model for calculating the equilibrium gas and particle concentrations of multiple semi-volatile organics within a bulk aerosol is extended to allow for multiple involatile aerosol modes of different sizes and chemical compositions. In the bulk aerosol problem, the partitioning coefficient determines the fraction of the total concentration of semi-volatile material that is in the condensed phase of the aerosol. This work modifies this definition for multiple polydisperse aerosol modes to account for multiple condensed concentrations, one for each semi-volatile on each involatile aerosol mode. The pivotal assumption in this work is that each aerosol mode contains an involatile constituent, thus overcoming the potential problem of smaller particles evaporating completely and then condensing on the larger particles to create a monodisperse aerosol at equilibrium. A parameterisation is proposed in which the coupled non-linear system of equations is approximated by a simpler set of equations obtained by setting the organic mole fraction in the partitioning coefficient to be the same across all modes. By perturbing the condensed masses about this approximate solution a correction term is derived that accounts for many of the removed complexities. This method offers a greatly increased efficiency in calculating the solution without significant loss in accuracy, thus making it suitable for inclusion in large-scale models.
1. New mass measurement method of aerosol particle using vibrating probe particle controlled by radiation pressure
Hariyama, Tatsuo; Takaya, Yasuhiro; Miyoshi, Takashi
2005-11-01
Aerosol particles with sub-micro meter size inhaled into respiratory systems cause serious damage to human body. In order to evaluate the health effects of the particles, classification methods of the particles with size and mass are needed. Several measurement methods of the particle size are established. However, conventional mass measurement methods are not enough to measure the particles with sub- pico gram. We propose a new mass measurement method of the aerosol particles based on laser trapping. In this method, an optically trapped silica particle is used as a measuring probe particle. The probe particle is trapped at a beam waist of the focused laser light and is forced to vibrate by deflecting the beam waist using AOD. The vibrating probe particle has a resonance frequency because it is governed by the spring-mass-damper system. When an aerosol particle is attached to the probe particle, the resonance frequency shifts according to the increase of the total mass. The mass of the aerosol particle can be measured from the shift of the resonance frequency. Experimentally, it is confirmed that the probe particle is governed by the spring-mass-damper system and has a resonance frequency. When a silica fine particle of 3pg in mass used as an aerosol particle is attached to the probe particle, the resonance frequency shift occurs as expected in the dynamic system and the fine particle mass can be measured based on the proposed method.
2. Thermophoretic separation of aerosol particles from a sampled gas stream
DOEpatents
Postma, Arlin K.
1986-01-01
A method for separating gaseous samples from a contained atmosphere that includes aerosol particles uses the step of repelling particles from a gas permeable surface or membrane by heating the surface to a temperature greater than that of the surrounding atmosphere. The resulting thermophoretic forces maintain the gas permeable surface clear of aerosol particles. The disclosed apparatus utilizes a downwardly facing heated plate of gas permeable material to combine thermophoretic repulsion and gravity forces to prevent particles of any size from contacting the separating plate surfaces.
3. Measurement of mass distribution of chemical species in aerosol particles
NASA Technical Reports Server (NTRS)
Sinha, M. P.; Friedlander, S. K.
1984-01-01
Aerosols may be generated through the nebulizing of solutions and the evaporation of their solvent, leaving the dry solute particles. Attention is presently given to a method for the direct determination of the masses of chemical species in individual aerosol particles on a continuous, real-time basis, using mass spectrometry. After the aerosol particles are introduced into the ion source of a quadrupole mass spectrometer, the particles impinge on a hot rhenium filament in the mass spectrometer's ion source. The resulting vapor plume is ionized by electron bombardment, and a pulse of ions is generated by each particle. The intensities of different masses in the ion pulses can then be measured by the mass spectrometer.
4. Carbonaceous aerosol particles from common vegetation in the Grand Canyon
SciTech Connect
Hallock, K.A.; Mazurek, M.A. ); Cass, G.R. . Dept. of Environmental Engineering Science)
1992-05-01
The problem of visibility reduction in the Grand Canyon due to fine organic aerosol particles in the atmosphere has become an area of increased environmental concern. Aerosol particles can be derived from many emission sources. In this report, we focus on identifying organic aerosols derived from common vegetation in the Grand Canyon. These aerosols are expected to be significant contributors to the total atmospheric organic aerosol content. Aerosol samples from living vegetation were collected by resuspension of surface wax and resin components liberated from the leaves of vegetation common to areas of the Grand Canyon. The samples were analyzed using high-resolution gas chromatography/mass spectrometry (GC/MS). Probable identification of compounds was made by comparison of sample spectra with National Institute of Standards and Technology (NIST) mass spectral references and positive identification of compounds was made when possible by comparison with authentic standards as well as NIST references. Using these references, we have been able to positively identify the presence of n-alkane and n-alkanoic acid homolog series in the surface waxes of the vegetation sampled. Several monoterpenes, sesquiterpenes, and diterpenes were identified also as possible biogenic aerosols which may contribute to the total organic aerosol abundance leading to visibility reduction in the Grand Canyon.
5. Regional signatures in the organic composition of marine aerosol particles
Frossard, Amanda A.; Russell, Lynn M.; Keene, William C.; Kieber, David J.; Quinn, Patricia K.; Bates, Timothy S.
2013-05-01
Marine aerosol particles play an important role in the earth's radiative balance, yet the sources and composition of the organic fraction remain largely unconstrained. Recent measurements have been made in order to characterize the sources, composition, and concentration of aerosol particles in the marine boundary layer. The organic composition of submicron particles derived from multiple seawater regions have been measured using Fourier Transform Infrared (FTIR) spectroscopy. Cluster analysis of FTIR organic spectra suggest different spectral signatures based on collection location, seawater composition, and ambient conditions. Measurements including non-refractory aerosol composition from a high-resolution time of flight aerosol mass spectrometer (HR-ToF-AMS), seawater composition, and wind speed were used to interpret the cluster results, depending on the availability from each campaign. FTIR spectra of ambient particles are compared to FTIR spectra of primary marine particles generated from model ocean systems to infer the ambient particle production mechanisms and aging processes. Recent measurements used in the comparison include ambient and generated marine aerosol particles measured off the coast of California during CalNex in May and June 2010. Remote ambient marine aerosol particles were collected 100 miles off the coast of Monterey in the eastern Pacific during the EPEACE experiment in July 2011. Ambient and generated marine particles were measured in two different seawater types during WACS 2012 including colder, more productive water off the coast of the northeastern United States and warmer, oligotrophic water in the Sargasso Sea. These particles are also compared with those measured in the southeastern Pacific during VOCALS and the north Atlantic during ICEALOT.
6. Polarization resolved angular optical scattering of aerosol particles
Redding, B.; Pan, Y.; Wang, C.; Videen, G.; Cao, Hui
2014-05-01
Real-time detection and identification of bio-aerosol particles are crucial for the protection against chemical and biological agents. The strong elastic light scattering properties of airborne particles provides a natural means for rapid, non-invasive aerosol characterization. Recent theoretical predictions suggested that variations in the polarization dependent angular scattering cross section could provide an efficient means of classifying different airborne particles. In particular, the polarization dependent scattering cross section of aggregate particles is expected to depend on the shape of the primary particles. In order to experimentally validate this prediction, we built a high throughput, sampling system, capable of measuring the polarization resolved angular scattering cross section of individual aerosol particles flowing through an interrogating volume with a single shot of laser pulse. We calibrated the system by comparing the polarization dependent scattering cross section of individual polystyrene spheres with that predicted by Mie theory. We then used the system to study different particles types: Polystyrene aggregates composed 500 nm spheres and Bacillus subtilis (BG, Anthrax simulant) spores composed of elongated 500 nm × 1000 nm cylinder-line particles. We found that the polarization resolved scattering cross section depends on the shape of the constituent elements of the aggregates. This work indicates that the polarization resolved scattering cross section could be used for rapid discrimination between different bio-aerosol particles.
7. Characteristics of aerosolized ice forming marine biogenic particles
Alpert, Peter A.
Ice particles are ubiquitous in the atmosphere existing as the sole constituents of glaciated cirrus clouds or coexisting with supercooled liquid droplets in mixed-phase clouds. Aerosol particles serving as heterogeneous ice nuclei for ice crystal formation impact the global radiative balance by modification of cloud radiative properties, and thus climate. Atmospheric ice formation is not a well understood process and represents great uncertainty for climate prediction. The oceans which cover the majority of the earth's surface host nearly half the total global primary productivity and contribute to the greatest aerosol production by mass. However, the effect of biological activity on particle aerosolization, particle composition, and ice nucleation is not well established. This dissertation investigates the link between marine biological activity, aerosol particle production, physical/chemical particle characteristics, and ice nucleation under controlled laboratory conditions. Dry and humidified aerosol size distributions of particles from bursting bubbles generated by plunging water jets and aeration through frits in a seawater mesocosm containing bacteria and/or phytoplankton cultures, were measured as a function of biological activity. Total particle production significantly increases primarily due to enhanced aerosolization of particles ≤100 nm in diameter attributable to the presence and growth of phytoplankton. Furthermore, hygroscopicity measurements indicate primary organic material associated with the sea salt particles, providing additional evidence for the importance of marine biological activity for ocean derived aerosol composition. Ice nucleation experiments show that these organic rich particles nucleate ice efficiently in the immersion and deposition modes, which underscores their importance in mixed-phase and cirrus cloud formation processes. In separate ice nucleation experiments employing pure cultures of Thalassiosira pseudonana, Nannochloris
8. New apparatus of single particle trap system for aerosol visualization
Higashi, Hidenori; Fujioka, Tomomi; Endo, Tetsuo; Kitayama, Chiho; Seto, Takafumi; Otani, Yoshio
2014-08-01
Control of transport and deposition of charged aerosol particles is important in various manufacturing processes. Aerosol visualization is an effective method to directly observe light scattering signal from laser-irradiated single aerosol particle trapped in a visualization cell. New single particle trap system triggered by light scattering pulse signal was developed in this study. The performance of the device was evaluated experimentally. Experimental setup consisted of an aerosol generator, a differential mobility analyzer (DMA), an optical particle counter (OPC) and the single particle trap system. Polystylene latex standard (PSL) particles (0.5, 1.0 and 2.0 μm) were generated and classified according to the charge by the DMA. Singly charged 0.5 and 1.0 μm particles and doubly charged 2.0 μm particles were used as test particles. The single particle trap system was composed of a light scattering signal detector and a visualization cell. When the particle passed through the detector, trigger signal with a given delay time sent to the solenoid valves upstream and downstream of the visualization cell for trapping the particle in the visualization cell. The motion of particle in the visualization cell was monitored by CCD camera and the gravitational settling velocity and the electrostatic migration velocity were measured from the video image. The aerodynamic diameter obtained from the settling velocity was in good agreement with Stokes diameter calculated from the electrostatic migration velocity for individual particles. It was also found that the aerodynamic diameter obtained from the settling velocity was a one-to-one function of the scattered light intensity of individual particles. The applicability of this system will be discussed.
9. LASER DESORPTION IONIZATION OF ULTRAFINE AEROSOL PARTICLES. (R823980)
EPA Science Inventory
On-line analysis of ultrafine aerosol particle in the 12 to 150 nm size range is performed by
laser desorption/ionization. Particles are size selected with a differential mobility analyzer and then
sent into a linear time-of-flight mass spectrometer where they are ablated w...
10. Aerosol particle microphotography and glare-spot absorption spectroscopy.
PubMed
Arnold, S; Holler, S; Li, J H; Serpengüzel, A; Auffermann, W F; Hill, S C
1995-04-01
The relative intensities of glare spots in the image of an electrodynamically trapped aerosol droplet are measured experimentally with an aerosol particle microscope and calculated theoretically. The theoretical calculations are in good agreement with these experiments and indicate that the intensities of these spots are extremely sensitive to the imaginary part of the refractive index. Experimentally, we obtain the molecular absorption spectrum of an impurity within a droplet by recording the spectrum of an individual glare spot produced by broadband illumination.
11. SAGE II aerosol validation - Selected altitude measurements, including particle micromeasurements
NASA Technical Reports Server (NTRS)
Oberbeck, Verne R.; Russell, Philip B.; Pueschel, Rudolf F.; Snetsinger, Kenneth G.; Ferry, Guy V.; Livingston, John M.; Rosen, James N.; Osborn, Mary T.; Kritz, Mark A.
1989-01-01
The validity of particulate extinction coefficients derived from limb path solar radiance measurements obtained during the Stratospheric Aerosol and Gas Experiment (SAGE) II is tested. The SAGE II measurements are compared with correlative aerosol measurements taken during January 1985, August 1985, and July 1986 with impactors, laser spectrometers, and filter samplers on a U-2 aircraft, an upward pointing lidar on a P-3 aircraft, and balloon-borne optical particle counters. The data for July 29, 1986 are discussed in detail. The aerosol measurements taken on this day at an altitude of 20.5 km produce particulate extinction values which validate the SAGE II values for similar wavelengths.
12. Reactions and mass spectra of complex particles using Aerosol CIMS
Hearn, John D.; Smith, Geoffrey D.
2006-12-01
Aerosol chemical ionization mass spectrometry (CIMS) is used both on- and off-line for the analysis of complex laboratory-generated and ambient particles. One of the primary advantages of Aerosol CIMS is the low degree of ion fragmentation, making this technique well suited for investigating the reactivity of complex particles. To demonstrate the usefulness of this "soft" ionization, particles generated from meat cooking were reacted with ozone and the composition was monitored as a function of reaction time. Two distinct kinetic regimes were observed with most of the oleic acid in these particles reacting quickly but with 30% appearing to be trapped in the complex mixture. Additionally, detection limits are measured to be sufficiently low (100-200 ng/m3) to detect some of the more abundant constituents in ambient particles, including sulfate, which is measured in real-time at 1.2 [mu]g/m3. To better characterize complex aerosols from a variety of sources, a novel off-line collection method was also developed in which non-volatile and semi-volatile organics are desorbed from particles and concentrated in a cold U-tube. Desorption from the U-tube followed by analysis with Aerosol CIMS revealed significant amounts of nicotine in cigarette smoke and levoglucosan in oak and pine smoke, suggesting that this may be a useful technique for monitoring particle tracer species. Additionally, secondary organic aerosol formed from the reaction of ozone with R-limonene and volatile organics from orange peel were analyzed off-line showing large molecular weight products (m/z > 300 amu) that may indicate the formation of oligomers. Finally, mass spectra of ambient aerosol collected offline reveal a complex mixture of what appears to be highly processed organics, some of which may contain nitrogen.
13. Complete chemical analysis of aerosol particles in real-time
SciTech Connect
Yang, Mo; Reilly, P.T.A.; Gieray, R.A.; Whitten, W.B.; Ramsey, J.M.
1996-12-31
Real-time mass spectrometry of individual aerosol particles using an ion trap mass spectrometer is described. The microparticles are sampled directly from the air by a particle inlet system into the vacuum chamber. An incoming particle is detected as it passes through two CW laser beams and a pulsed laser is triggered to intercept the particle for laser ablation ionization at the center of the ion trap. The produced ions are analyzed by the ion trap mass spectrometer. Ions of interest are selected and dissociated through collision with buffer gas atoms for further fragmentation analysis. Real-time chemical analyses of inorganic, organic, and bacterial aerosol articles have been demonstrated. It has been confirmed that the velocity and the size of the incoming particles highly correlate to each other. The performance of the inlet system, particle detection, and preliminary results are discussed.
14. Observations of fluorescent aerosol-cloud interactions in the free troposphere at the High-Altitude Research Station Jungfraujoch
Crawford, I.; Lloyd, G.; Herrmann, E.; Hoyle, C. R.; Bower, K. N.; Connolly, P. J.; Flynn, M. J.; Kaye, P. H.; Choularton, T. W.; Gallagher, M. W.
2016-02-01
The fluorescent nature of aerosol at a high-altitude Alpine site was studied using a wide-band integrated bioaerosol (WIBS-4) single particle multi-channel ultraviolet - light-induced fluorescence (UV-LIF) spectrometer. This was supported by comprehensive cloud microphysics and meteorological measurements with the aims of cataloguing concentrations of bio-fluorescent aerosols at this high-altitude site and also investigating possible influences of UV-fluorescent particle types on cloud-aerosol processes. Analysis of background free tropospheric air masses, using a total aerosol inlet, showed there to be a minor increase in the fluorescent aerosol fraction during in-cloud cases compared to out-of-cloud cases. The size dependence of the fluorescent aerosol fraction showed the larger aerosol to be more likely to be fluorescent with 80 % of 10 μm particles being fluorescent. Whilst the fluorescent particles were in the minority (NFl/NAll = 0.27 ± 0.19), a new hierarchical agglomerative cluster analysis approach, Crawford et al. (2015) revealed the majority of the fluorescent aerosols were likely to be representative of fluorescent mineral dust. A minor episodic contribution from a cluster likely to be representative of primary biological aerosol particles (PBAP) was also observed with a wintertime baseline concentration of 0.1 ± 0.4 L-1. Given the low concentration of this cluster and the typically low ice-active fraction of studied PBAP (e.g. pseudomonas syringae), we suggest that the contribution to the observed ice crystal concentration at this location is not significant during the wintertime.
15. Thermophoretic separation of aerosol particles from a sampled gas stream
DOEpatents
Postma, A.K.
1984-09-07
This disclosure relates to separation of aerosol particles from gas samples withdrawn from within a contained atmosphere, such as containment vessels for nuclear reactors or other process equipment where remote gaseous sampling is required. It is specifically directed to separation of dense aerosols including particles of any size and at high mass loadings and high corrosivity. The United States Government has rights in this invention pursuant to Contract DE-AC06-76FF02170 between the US Department of Energy and Westinghouse Electric Corporation.
16. FTIR Analysis of Functional Groups in Aerosol Particles
Shokri, S. M.; McKenzie, G.; Dransfield, T. J.
2012-12-01
Secondary organic aerosols (SOA) are suspensions of particulate matter composed of compounds formed from chemical reactions of organic species in the atmosphere. Atmospheric particulate matter can have impacts on climate, the environment and human health. Standardized techniques to analyze the characteristics and composition of complex secondary organic aerosols are necessary to further investigate the formation of SOA and provide a better understanding of the reaction pathways of organic species in the atmosphere. While Aerosol Mass Spectrometry (AMS) can provide detailed information about the elemental composition of a sample, it reveals little about the chemical moieties which make up the particles. This work probes aerosol particles deposited on Teflon filters using FTIR, based on the protocols of Russell, et al. (Journal of Geophysical Research - Atmospheres, 114, 2009) and the spectral fitting algorithm of Takahama, et al (submitted, 2012). To validate the necessary calibration curves for the analysis of complex samples, primary aerosols of key compounds (e.g., citric acid, ammonium sulfate, sodium benzoate) were generated, and the accumulated masses of the aerosol samples were related to their IR absorption intensity. These validated calibration curves were then used to classify and quantify functional groups in SOA samples generated in chamber studies by MIT's Kroll group. The fitting algorithm currently quantifies the following functionalities: alcohols, alkanes, alkenes, amines, aromatics, carbonyls and carboxylic acids.
17. Heterogeneous particle deaggregation and its implication for therapeutic aerosol performance.
PubMed
Xu, Zhen; Mansour, Heidi M; Mulder, Tako; McLean, Richard; Langridge, John; Hickey, Anthony J
2010-08-01
Aerosolization performance of dry powder blends of drugs for the treatment of asthma or chronic obstructive pulmonary diseases have been reported in three previous articles. In vitro aerosolization was performed at defined shear stresses (0.624-13.143 N/m(2)). Formulations were characterized aerodynamically and powder aerosol deaggregation equations (PADE) and corresponding linear regression analyses for pharmaceutical aerosolization were applied. Particle deaggregation is the result of overcoming fundamental forces acting at the particle interface. A new method, PADE, describing dry powder formulation performance in a shear stress range has been developed which may allow a fundamental understanding of interparticulate and surface forces. The application of PADE predicts performance efficiency and reproducibility and supports rational design of dry powder formulations. The analogy of aerosol performance with surface molecular adsorption has important implications. Expressions describing surface adsorption were intended to allow elucidation of mechanisms involving surface heterogeneity, lateral interaction, and multilayer adsorption of a variety of materials. By using a similar expression for drug aerosolization performance, it is conceivable that an analogous mechanistic approach to the evaluation of particulate systems would be possible.
18. Accelerated simulation of stochastic particle removal processes in particle-resolved aerosol models
SciTech Connect
Curtis, J.H.; Michelotti, M.D.; Riemer, N.; Heath, M.T.; West, M.
2016-10-01
Stochastic particle-resolved methods have proven useful for simulating multi-dimensional systems such as composition-resolved aerosol size distributions. While particle-resolved methods have substantial benefits for highly detailed simulations, these techniques suffer from high computational cost, motivating efforts to improve their algorithmic efficiency. Here we formulate an algorithm for accelerating particle removal processes by aggregating particles of similar size into bins. We present the Binned Algorithm for particle removal processes and analyze its performance with application to the atmospherically relevant process of aerosol dry deposition. We show that the Binned Algorithm can dramatically improve the efficiency of particle removals, particularly for low removal rates, and that computational cost is reduced without introducing additional error. In simulations of aerosol particle removal by dry deposition in atmospherically relevant conditions, we demonstrate about 50-times increase in algorithm efficiency.
19. Unique DNA-barcoded aerosol test particles for studying aerosol transport
SciTech Connect
Harding, Ruth N.; Hara, Christine A.; Hall, Sara B.; Vitalis, Elizabeth A.; Thomas, Cynthia B.; Jones, A. Daniel; Day, James A.; Tur-Rojas, Vincent R.; Jorgensen, Trond; Herchert, Edwin; Yoder, Richard; Wheeler, Elizabeth K.; Farquar, George R.
2016-03-22
Data are presented for the first use of novel DNA-barcoded aerosol test particles that have been developed to track the fate of airborne contaminants in populated environments. Until DNATrax (DNA Tagged Reagents for Aerosol eXperiments) particles were developed, there was no way to rapidly validate air transport models with realistic particles in the respirable range of 1–10 μm in diameter. The DNATrax particles, developed at Lawrence Livermore National Laboratory (LLNL) and tested with the assistance of the Pentagon Force Protection Agency, are the first safe and effective materials for aerosol transport studies that are identified by DNA molecules. The use of unique synthetic DNA barcodes overcomes the challenges of discerning the test material from pre-existing environmental or background contaminants (either naturally occurring or previously released). The DNATrax particle properties are demonstrated to have appropriate size range (approximately 1–4.5 μm in diameter) to accurately simulate bacterial spore transport. As a result, we describe details of the first field test of the DNATrax aerosol test particles in a large indoor facility.
20. Unique DNA-barcoded aerosol test particles for studying aerosol transport
DOE PAGES
Harding, Ruth N.; Hara, Christine A.; Hall, Sara B.; ...
2016-03-22
Data are presented for the first use of novel DNA-barcoded aerosol test particles that have been developed to track the fate of airborne contaminants in populated environments. Until DNATrax (DNA Tagged Reagents for Aerosol eXperiments) particles were developed, there was no way to rapidly validate air transport models with realistic particles in the respirable range of 1–10 μm in diameter. The DNATrax particles, developed at Lawrence Livermore National Laboratory (LLNL) and tested with the assistance of the Pentagon Force Protection Agency, are the first safe and effective materials for aerosol transport studies that are identified by DNA molecules. The usemore » of unique synthetic DNA barcodes overcomes the challenges of discerning the test material from pre-existing environmental or background contaminants (either naturally occurring or previously released). The DNATrax particle properties are demonstrated to have appropriate size range (approximately 1–4.5 μm in diameter) to accurately simulate bacterial spore transport. As a result, we describe details of the first field test of the DNATrax aerosol test particles in a large indoor facility.« less
1. Selection of quasi-monodisperse super-micron aerosol particles
Rösch, Michael; Pfeifer, Sascha; Wiedensohler, Alfred; Stratmann, Frank
2014-05-01
Size-segregated quasi monodisperse particles are essential for e.g. fundamental research concerning cloud microphysical processes. Commonly a DMA (Differential Mobility Analyzer) is used to produce quasi-monodisperse submicron particles. Thereto first, polydisperse aerosol particles are bipolarly charged by a neutralizer, and then selected according to their electrical mobility with the DMA [Knutson et al. 1975]. Selecting a certain electrical mobility with a DMA results in a particle size distribution, which contains singly charged particles as well as undesired multiply charged larger particles. Often these larger particles need to either be removed from the generated aerosol or their signals have to be corrected for in the data inversion and interpretation process. This problem becomes even more serious when considering super-micron particles. Here we will present two different techniques for generating quasi-monodisperse super-micron aerosol particles with no or only an insignificant number of larger sized particles being present. First, we use a combination of a cyclone with adjustable aerodynamic cut-off diameter and our custom-built Maxi-DMA [Raddatz et al. 2013]. The cyclone removes particles larger than the desired ones prior to mobility selection with the DMA. This results in a reduction of the number of multiply charged particles of up to 99.8%. Second, we utilize a new combination of cyclone and PCVI (Pumped Counterflow Virtual Impactor), which is based on purely inertial separation and avoids particle charging. The PCVI instrument was previously described by Boulter et al. (2006) and Kulkarni et al. (2011). With our two setups we are able to produce quasi-monodisperse aerosol particles in the diameter range from 0.5 to 4.4 µm without a significant number of larger undesired particles being present. Acknowledgements: This work was done within the framework of the DFG funded Ice Nucleation research UnIT (INUIT, FOR 1525) under WE 4722/1-1. References
2. Time Resolved Measurements of Primary Biogenic Aerosol Particles in Amazonia
Wollny, A. G.; Garland, R.; Pöschl, U.
2009-04-01
Biogenic aerosols are ubiquitous in the Earth's atmosphere and they influence atmospheric chemistry and physics, the biosphere, climate, and public health. They play an important role in the spread of biological organisms and reproductive materials, and they can cause or enhance human, animal, and plant diseases. Moreover, they influence the Earth's energy budget by scattering and absorbing radiation, and they can initiate the formation of clouds and precipitation as cloud condensation and ice nuclei. The composition, abundance, and origin of biogenic aerosol particles and components are, however, still not well understood and poorly quantified. Prominent examples of primary biogenic aerosol particles, which are directly emitted from the biosphere to the atmosphere, are pollen, bacteria, fungal spores, viruses, and fragments of animals and plants. During the Amazonian Aerosol Characterization Experiment (AMAZE-08) a large number of aerosol and gas-phase measurements were taken on a remote site close to Manaus, Brazil, during a period of five weeks in February and March 2008. This presented study is focused on data from an ultraviolet aerodynamic particle sizer (UVAPS, TSI inc.) that has been deployed for the first time in Amazonia. In this instrument, particle counting and aerodynamic sizing over the range of 0.5-20 µm are complemented by the measurement of UV fluorescence at 355 nm (excitation) and 420-575 nm (emission), respectively. Fluorescence at these wavelengths is characteristic for reduced pyridine nucleotides (e.g., NAD(P)H) and for riboflavin, which are specific for living cells. Thus particles exhibiting fluorescence signals can be regarded as "viable aerosols" or "fluorescent bioparticles" (FBAP), and their concentration can be considered as lower limit for the actual abundance of primary biogenic aerosol particles. Data from the UVAPS were averaged over 5 minute time intervals. The presence of bioparticles in the observed size range has been
3. Individual-Particle Analysis of Aerosols From Southern Africa
Li, J.; Posfai, M.; Hobbs, P. V.; Buseck, P. R.
2001-12-01
Aerosol samples were collected on the University of Washington Convair-580 research aircraft over southern Africa during the Safari 2000 Experiment. Individual aerosol particles were analyzed using transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FESEM) with energy-dispersive x-ray spectrometry (EDS). The objective of the study is to characterize the major aerosol emissions from biomass burning over southern Africa, with emphasis on the sizes, shapes, compositions, mixing states, and surface coatings of the aerosols. Aging and reaction of smoke aerosols with plume transport were investigated. Particulate emissions from combustion of different vegetation types and at different burning phases were compared. Preliminary results show that aerosols from biomass burning mainly consist of amorphous carbonaceous spherules ("tar balls"); soot; K salts including KCl, K2SO4, and probably KNO3 mixed with organic particles; and Ca-bearing particles including Ca carbonate, phosphate, and sulfate. Minor amounts of sea salt and minerals such as quartz, mica, smectite, and gypsum are also present. The relative concentrations of tar balls increase with distance from the fires. More KCl particles occur in fresh smoke plumes close to fire sources, whereas more K2SO4 and KNO3 particles are present in aged smoke. This change indicates that KCl forming from the fire was converted to K2SO4 and KNO3 through reactions with S- and N-bearing species emitted from biomass burning. The conversion of KCl resembles that of NaCl in sea salt particles, suggesting similar reaction mechanisms with the aging of smoke. More soot is present in smoke from flaming grass fires than bush and wood fires, which is probably related to the high fraction of flaming combustion of grass fires. The high abundance of organic particles and soluble salt may affect the hygroscopic properties of biomass burning aerosols and influence their role as cloud condensation nuclei
4. Novel Measurements of Aerosol Particle Interfaces Using Biphasic Microfluidics
Metcalf, A. R.; Dutcher, C. S.
2014-12-01
Secondary organic aerosol (SOA) particles are nearly ubiquitous in the atmosphere and yet there remains large uncertainties in their formation processes and ambient properties. These particles are complex microenvironments, which can contain multiple interfaces due to internal aqueous-organic phase partitioning and to the external liquid-vapor surface. These aerosol interfaces can profoundly affect the fate of condensable organic compounds emitted into the atmosphere by altering the way in which organic vapors interact with the ambient aerosol. Aerosol interfaces affect particle internal structure, species uptake, equilibrium partitioning, activation to cloud condensation or ice nuclei, and optical properties. For example, organic thin films can shield the core of the aerosol from the ambient environment, which may disrupt equilibrium partitioning and mass transfer. To improve our ability to accurately predict the fate of SOA in the atmosphere, we must improve our knowledge of aerosol interfaces and their interactions with the ambient environment. Few technologies exist to accurately probe aerosol interfaces at atmospherically-relevant conditions. In this talk, a novel method using biphasic microscale flows will be introduced for generating, trapping, and perturbing complex interfaces at atmospherically relevant conditions. These microfluidic experiments utilize high-speed imaging to monitor interfacial phenomena at the microscale and are performed with phase contrast and fluorescence microscopy on a temperature-controlled inverted microscope stage. From these experiments, interfacial thermodynamic properties such as surface tension, rheological properties such as interfacial moduli, and kinetic properties such as mass transfer coefficients can be measured or inferred. Chemical compositions of the liquid phases studied here span a range of viscosities and include electrolyte and water soluble organic acid species often observed in the atmosphere, such as mixtures
5. Processing of aerosol particles within the Habshan pollution plume
Semeniuk, T. A.; Bruintjes, R.; Salazar, V.; Breed, D.; Jensen, T.; Buseck, P. R.
2015-03-01
The Habshan industrial site in the United Arab Emirates produces a regional-scale pollution plume associated with oil and gas processing, discharging high loadings of sulfates and chlorides into the atmosphere, which interact with the ambient aerosol population. Aerosol particles and trace gas chemistry at this site were studied on two flights in the summer of 2002. Measurements were collected along vertical plume profiles to show changes associated with atmospheric processing of particle and gas components. Close to the outlet stack, particle concentrations were over 10,000 cm-3, dropping to <2000 cm-3 in more dilute plume around 1500 m above the stack. Particles collected close to the stack and within the dilute plume were individually measured for size, morphology, composition, and mixing state using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy. Close to the stack, most coarse particles consisted of mineral dust and NaCl crystals from burning oil brines, while sulfate droplets dominated the fine mode. In more dilute plume, at least 1500 m above the stack, the particle spectrum was more diverse, with a significant increase in internally mixed particle types. Dilute plume samples consisted of coarse NaCl/silicate aggregates or NaCl-rich droplets, often with a sulfate component, while fine-fraction particles were of mixed cation sulfates, also internally mixed with nanospherical soot or silicates. Thus, both chloride and sulfate components of the pollution plume rapidly reacted with ambient mineral dust to form coated and aggregate particles, enhancing particle size, hygroscopicity, and reactivity of the coarse mode. The fine-fraction sulfate-bearing particles formed in the plume contribute to regional transport of sulfates, while coarse sulfate-bearing fractions locally reduced the SO2 loading through sedimentation. The chloride- and sulfate-bearing internally mixed particles formed in the plume markedly changed the
6. Magnetic targeting of aerosol particles for cancer therapy
2005-05-01
An in vitro model was developed to study and demonstrate the potential and feasibility of magnetically targeted deposition of aerosols for potential applications in lung cancer treatment. Also, a numerical particle tracing model was developed to predict the targeting behavior of the in vitro system; the results from the numerical and experimental studies were in agreement.
7. Ice Nucleation Activity of Various Agricultural Soil Dust Aerosol Particles
Schiebel, Thea; Höhler, Kristina; Funk, Roger; Hill, Thomas C. J.; Levin, Ezra J. T.; Nadolny, Jens; Steinke, Isabelle; Suski, Kaitlyn J.; Ullrich, Romy; Wagner, Robert; Weber, Ines; DeMott, Paul J.; Möhler, Ottmar
2016-04-01
Recent investigations at the cloud simulation chamber AIDA (Aerosol Interactions and Dynamics in the Atmosphere) suggest that agricultural soil dust has an ice nucleation ability that is enhanced up to a factor of 10 compared to desert dust, especially at temperatures above -26 °C (Steinke et al., in preparation for submission). This enhancement might be caused by the contribution of very ice-active biological particles. In addition, soil dust aerosol particles often contain a considerably higher amount of organic matter compared to desert dust particles. To test agricultural soil dust as a source of ice nucleating particles, especially for ice formation in warm clouds, we conducted a series of laboratory measurements with different soil dust samples to extend the existing AIDA dataset. The AIDA has a volume of 84 m3 and operates under atmospherically relevant conditions over wide ranges of temperature, pressure and humidity. By controlled adiabatic expansions, the ascent of an air parcel in the troposphere can be simulated. As a supplement to the AIDA facility, we use the INKA (Ice Nucleation Instrument of the KArlsruhe Institute of Technology) continuous flow diffusion chamber based on the design by Rogers (1988) to expose the sampled aerosol particles to a continuously increasing saturation ratio by keeping the aerosol temperature constant. For our experiments, soil dust was dry dispersed into the AIDA vessel. First, fast saturation ratio scans at different temperatures were performed with INKA, sampling soil dust aerosol particles directly from the AIDA vessel. Then, we conducted the AIDA expansion experiment starting at a preset temperature. The combination of these two different methods provides a robust data set on the temperature-dependent ice activity of various agriculture soil dust aerosol particles with a special focus on relatively high temperatures. In addition, to extend the data set, we investigated the role of biological and organic matter in more
8. A dual-wavelength single particle aerosol fluorescence monitor
Kaye, Paul H.; Stanley, Warren R.; Foot, Virginia; Baxter, Karen; Barrington, Stephen J.
2005-10-01
Laser diodes and light-emitting diodes capable of continuous sub-300 nm radiation emission will ultimately represent optimal excitation sources for compact and fieldable bio-aerosol monitors. However, until such devices are routinely available and whilst solid-state UV lasers remain relatively expensive, other low-cost sources of UV can offer advantages. This paper describes one such prototype that employs compact xenon discharge UV sources to excite intrinsic fluorescence from individual particles within an ambient aerosol sample. The prototype monitor samples ambient air via a laminar sheathed-flow arrangement such that particles within the sample flow column are rendered in single file as they intersect the beam from a continuous-wave 660nm diode laser. Each individual particle produces a scattered light signal from which an estimate of particle size (down to ~1 um) may be derived. This same signal also initiates the sequential firing (~10 us apart) of two xenon sources which irradiate the particle with UV pulses centred upon ~280 nm and ~370 nm wavelength, optimal for excitation of bio-fluorophores tryptophan and NADH respectively. For each excitation wavelength, fluorescence is detected across two bands embracing the peak emissions of the same bio-fluorophores. Thus, for each particle, a 2-dimensional fluorescence excitation-emission matrix is recorded together with an estimate of particle size. Current measurement rates are up to ~125 particles/s (limited by the xenon recharge time), corresponding to all particles for concentrations up to ~2 x 104 particles/l. Developments to increase this to ~500 particles/s are in hand. Analysis of results from aerosols of E.coli, BG spores, and a variety of non-biological materials are given.
9. Single particle multichannel bio-aerosol fluorescence sensor
Kaye, P. H.; Stanley, W. R.; Hirst, E.; Foot, E. V.; Baxter, K. L.; Barrington, S. J.
2005-05-01
We describe a prototype low-cost multi-channel aerosol fluorescence sensor designed for unattended deployment in medium to large area bio-aerosol detection networks. Individual airborne particles down to ~1μm in size are detected and sized by measurement of light scattered from a continuous-wave diode laser (660nm). This scatter signal is then used to trigger the sequential firing of two xenon sources which irradiate the particle with UV pulses at ~280 nm and ~370 nm, optimal for excitation of bio-fluorophores tryptophan and NADH (nicotinamide adenine dinucleotide) respectively. For each excitation wavelength, fluorescence is detected across two bands embracing the peak emissions of the same bio-fluorophores. Current measurement rates are up to ~125 particles/s, corresponding to all particles for concentrations up to 1.3 x 104 particles/l. Developments to increase this to ~500 particles/s are in hand. Device sensitivity is illustrated in preliminary data recorded from aerosols of E.coli, BG spores, and a variety of non-biological materials.
10. Ambient particle characterization by single particle aerosol mass spectrometry in an urban area of Beijing
Li, Lei; Li, Mei; Huang, Zhengxu; Gao, Wei; Nian, Huiqing; Fu, Zhong; Gao, Jian; Chai, Fahe; Zhou, Zhen
2014-09-01
To investigate the composition and possible sources of aerosol particles in Beijing urban area, a single particle aerosol mass spectrometer (SPAMS) was deployed from April 22 to May 4, 2011. 510,341 particles out of 2,953,200 sized particles were characterized by SPAMS in combination with the ART-2a neural network algorithm. The particles were classified as rich-K (39.79%), carbonaceous species (32.7%), industry metal (19.2%), dust (5.7%), and rich-Na (1.76%). Industrial emissions related particles, rich-Fe, rich-Pb, and K-nitrate, were the major components of aerosol particles during haze periods, which were mainly from the steel plants and metal smelting processes around Beijing. Under stagnant meterological conditions, these regional emissions have a vital effect on haze formation. Organic carbon (OC) particles were attributed to biomass burning. NaK-EC was likely to come from local traffic emissions. Internally mixed organic and elemental carbon (OCEC) was found to be from possible sources of local traffic emission and biomass burning. It was found that coarse dust particles were mainly composed of four different types of dust particles, dust-Si, dust-Ca, dust-Al, and dust-Ti. It is the first time that SPAMS was used to study a dust storm in Beijing. Our results showed that SPAMS could be a powerful tool in the identification and apportionment of aerosol sources in Beijing, providing useful reference information for environmental control and management.
11. Dispersion of aerosol particles in the atmosphere: Fukushima
Haszpra, Tímea; Lagzi, István; Tél, Tamás
2013-04-01
Investigation of dispersion and deposition of aerosol particles in the atmosphere is an essential issue, because they have an effect on the biosphere and atmosphere. Moreover, aerosol particles have different transport properties and chemical and physical transformations in the atmosphere compared to gas phase air pollutants. The motion of a particle is described by a set of ordinary differential equations. The large-scale dynamics in the horizontal direction can be described by the equations of passive scalar advection, but in the vertical direction a well-defined terminal velocity should be taken into account as a term added to the vertical wind component. In the planetary boundary layer turbulent diffusion has an important role in the particle dispersion, which is taken into account by adding stochastic terms to the deterministic equations above. Wet deposition is also an essential process in the lower levels of the atmosphere, however, its precise parameterization is a challenge. For the simulations the wind field and other necessary data were taken from the ECMWF ERA-Interim database. In the case of the Fukushima Daiichi nuclear disaster (March-April 2011) radioactive aerosol particles were also released in the planetary boundary layer. Simulations (included the continuous and varying emission from the nuclear power plant) will be presented for the period of 14-23 March. Results show that wet deposition also has to be taken into consideration in the lower levels of the atmosphere. Furthermore, dynamical system characteristics are evaluated for the aerosol particle dynamics. The escape rate of particles was estimated both with and without turbulent diffusion, and in both cases when there was no wet deposition and also when wet deposition was taken into consideration.
12. Characterization of aerosol particles at the forested site in Lithuania
Rimselyte, I.; Garbaras, A.; Kvietkus, K.; Remeikis, V.
2009-04-01
Atmospheric particulate matter (PM), especially fine particles (particles with aerodynamic diameter less than 1 m, PM1), has been found to play an important role in global climate change, air quality, and human health. The continuous study of aerosol parameters is therefore imperative for better understanding the environmental effects of the atmospheric particles, as well as their sources, formation and transformation processes. The particle size distribution is particularly important, since this physical parameter determines the mass and number density, lifetime and atmospheric transport, or optical scattering behavior of the particles in the atmosphere (Jaenicke, 1998). Over the years several efforts have been made to improve the knowledge about the chemical composition of atmospheric particles as a function of size (Samara and Voutsa, 2005) and to characterize the relative contribution of different components to the fine particulate matter. It is well established that organic materials constitute a highly variable fraction of the atmospheric aerosol. This fraction is predominantly found in the fine size mode in concentrations ranging from 10 to 70% of the total dry fine particle mass (Middlebrook et al., 1998). Although organic compounds are major components of the fine particles, the composition, formation mechanism of organic aerosols are not well understood. This is because particulate organic matter is part of a complex atmospheric system with hundreds of different compounds, both natural and anthropogenic, covering a wide range of chemical properties. The aim of this study was to characterize the forest PM1, and investigate effects of air mass transport on the aerosol size distribution and chemical composition, estimate and provide insights into the sources and characteristics of carbonaceous aerosols through analysis ^13C/12C isotopic ratio as a function of the aerosol particles size. The measurements were performed at the Rugšteliškis integrated
13. Aerosol growth in Titan's ionosphere through particle charging
Lavvas, P.; Yelle, R. V.; Koskinen, T.; Bazin, A.; Vuitton, V.; Vigren, E.; Galand, M. F.; Wellbrock, A.; Coates, A. J.; Wahlund, J.; Crary, F.; Snowden, D. S.
2012-12-01
Observations of Titan's lower thermosphere and ionosphere by Cassini instruments demonstrate the presence of large mass negative ions of a few thousand amu, and the presence of positive ions up to a few hundred amu [1,2]. The mechanisms though responsible for the production of these large ions have so far remained elusive. A recent Titan flyby that probed deeper layers of Titan's thermosphere than usual, revealed a discrepancy in the observed positive ion and electron density, with the electron density lower than the abundance required to satisfy charge balance [3]. The remaining electron density was found in the form of the large mass negative ions. Aerosols can be charged on interaction with electrons and ions, while this charge can affect the particle coagulation, thus, their subsequent growth. Given the above observations we investigate here the potential role of aerosols in Titan's ionosphere and how this interaction affects the aerosol evolution. This investigation is performed with the use of a model that couples between the ionospheric photochemical evolution and the microphysical growth of aerosols in a self-consistent approach. Our results show that particle charging has an important role in the ionosphere. Most of the produced particles in the ionosphere attain a negative charge. Thus, they act as a sink for the free electrons with the remaining free electron densities consistent with the recent Cassini observations. Being negatively charged, the particles repel each other reducing in this way the coagulation rates and the growth of the aerosols. On the other hand, the negatively charged particles attract the abundant positive ions, which results to enhanced collisions between them. The mass added to the particles by the ions leads to an increase in their size and an increase in the resulting mass flux of the aerosols. Our simulated mass per charge spectra provide excellent fits to the observed positive and negative ion spectra from the Cassini Plasma
14. Aerosol particles and the formation of advection fog
NASA Technical Reports Server (NTRS)
Hung, R. J.; Liaw, G. S.; Vaughan, O. H., Jr.
1979-01-01
A study of numerical simulation of the effects of concentration, particle size, mass of nuclei, and chemical composition on the dynamics of warm fog formation, particularly the formation of advection fog, is presented. This formation is associated with the aerosol particle characteristics, and both macrophysical and microphysical processes are considered. In the macrophysical model, the evolution of wind components, water vapor content, liquid water content, and potential temperature under the influences of vertical turbulent diffusion, turbulent momentum, and turbulent energy transfers are taken into account. In the microphysical model, the supersaturation effect is incorporated with the surface tension and hygroscopic material solution. It is shown that the aerosol particles with the higher number density, larger size nuclei, the heavier nuclei mass, and the higher ratio of the Van't Hoff factor to the molecular weight favor the formation of the lower visibility advection fogs with stronger vertical energy transfer during the nucleation and condensation time period.
15. Surface Chemistry at Size-Selected Nano-Aerosol Particles
Roberts, Jeffrey
2005-03-01
A method has been developed to conduct surface chemistry and extract surface kinetic rates from size-selected aerosol nanoparticles. The measurements encompass broad ranges of particle size, phase, and composition. Results will be presented on the uptake of water by aerosolized soot nanoparticles of radius between 10 and 40 nm. Water uptake was monitored by tandem differential mobility analysis (T-DMA), which is capable of measuring changes in particle diameter as little as 0.2 nm. Soot particles were produced in an ethene diffusion flame and extracted into an atmospheric pressure aerosol flow tube reactor. The particles were subjected to various thermal and oxidative treatments, and the effects of these treatments on the ability of soot to adsorb monolayer quantities of water was determined. The results are important because soot nucleates atmospheric cloud particles. More generally, the results represent one of the first kinetic and mechanistic studies of gas-phase nanoparticle reactivity. Co-author: Henry Ajo, University of Minnesota
16. Study of primary biological aerosols to characterize their diversity in particulate matter over the Indian tropical region: assessment for climatic and health impact
Priyamvada R, H.; Muthalagu, A.; R, R.; Verma, R. S.; Philip, L.; Desprès, V.; Poeschl, U.; Gunthe, S. S.
2015-12-01
Primary Biological Aerosol Particles (PBAPs) are ubiquitous in the Earth's atmosphere and can influence the biosphere, climate, and public health (Després et al., 2012).To study the importance of the PBAPs, it is important to have an understanding about their origin, seasonal abundance and diversity. The study of PBAPs over the Indian tropical region becomes important as it hosts ~ 18% of the world population and has a distinct climate with a systematic and cyclic monsoon season which is different from the continental climates in Europe and America. In this study, the PBAPs were characterized by the application of molecular genetic techniques involving DNA extraction, PCR amplifications, cloning and DNA sequencing. In addition, characterization of the fungal source emissions was performed to better understand the diversity, abundance, and relative contribution of the fungal aerosols. For the present study, DNA analysis was performed on a one-year air filter set of PM10 (particulate matter ≤10 mm) covering three distinct meteorological seasons, i.e. summer, monsoon, and winter. The results from DNA analysis revealed the presence of bacteria and fungi in the filter samples. The fungal source characterization performed by the DNA analysis revealed the ratio of Basidiomycota to Ascomycota to be 96:4, which is consistent with previously reported studies from airborne fungal communities in the European continental boundary layer air (Fröhlich-Nowoisky et al., 2009). In the study region, the highest species richness was found to be present in the family Agaricaceae (25.3%) followed by Polyporaceae (15.3%) and Marasmiaceae (10.81%). Agaricaceae, Polyporaceae and Psathyrellaceae were dominant families in the study region and the families like Clavariaceae, Nectriaceae, Phanerochaetachae, Pleurotaceae and Strophariaceae were found to be rare. The results will next be compared with the diversity and types of the fungi found in ambient PM10. More details will be presented.
17. Chemical evolution of multicomponent aerosol particles during evaporation
Zardini, Alessandro; Riipinen, Ilona; Pagels, Joakim; Eriksson, Axel; Worsnop, Douglas; Switieckli, Erik; Kulmala, Markku; Bilde, Merete
2010-05-01
Atmospheric aerosol particles have an important but not well quantified effect on climate and human health. Despite the efforts made in the last decades, the formation and evolution of aerosol particles in the atmosphere is still not fully understood. The uncertainty is partly due to the complex chemical composition of the particles which comprise inorganic and organic compounds. Many organics (like dicarboxylic acids) can be present both in the gas and in the condensed phase due to their low vapor pressure. Clearly, an understanding of this partition is crucial to address any other issue in atmospheric physics and chemistry. Moreover, many organics are water soluble, and their influence on the properties of aqueous solution droplets is still poorly characterized. The solid and sub-cooled liquid state vapor pressures of some organic compounds have been previously determined by measuring the evaporation rate of single-compound crystals [1-3] or binary aqueous droplets [4-6]. In this work, we deploy the HTDMA technique (Hygroscopicity Tandem Differential Mobility Analyzer) coupled with a 3.5m laminar flow-tube and an Aerosol Mass Spectrometer (AMS) for determining the chemical evolution during evaporation of ternary droplets made of one dicarboxylic acid (succinic acid, commonly found in atmospheric samples) and one inorganic compound (sodium chloride or ammonium sulfate) in different mixing ratios, in equilibrium with water vapor at a fixed relative humidity. In addition, we investigate the evaporation of multicomponent droplets and crystals made of three organic species (dicarboxylic acids and sugars), of which one or two are semi-volatile. 1. Bilde M. and Pandis, S.N.: Evaporation Rates and Vapor Pressures of Individual Aerosol Species Formed in the Atmospheric Oxidation of alpha- and beta-Pinene. Environmental Science and Technology, 35, 2001. 2. Bilde M., et al.: Even-Odd Alternation of Evaporation Rates and Vapor Pressures of C3-C9 Dicarboxylic Acid Aerosols
18. Thermophoretic motion of large heated aerosol spherical particles
Malai, N. V.; Limanskaya, A. V.; Shchukin, E. R.
2016-03-01
The stationary motion of a large spherical aerosol particle in the external field of a temperature gradient in zero gravity is theoretically described using the Stokes approximation and the assumption that the average temperature of the particle surface differs considerably from the temperature of the surrounding gaseous medium. The gas dynamics equations are solved taking into account the power-law temperature dependence of the molecular transport coefficients (viscosity, thermal conductivity) and the density of the gaseous medium. Numerical estimates show that the dependence of the thermophoretic force and velocity on the average temperature of the particle surface is nonlinear.
19. Comparison of the DiSCmini aerosol monitor to a handheld condensation particle counter and a scanning mobility particle sizer for submicrometer sodium chloride and metal aerosols
PubMed Central
Mills, Jessica B.; Park, Jae Hong; Peters, Thomas M.
2016-01-01
We evaluated the robust, lightweight DiSCmini (DM) aerosol monitor for its ability to measure the concentration and mean diameter of submicrometer aerosols. Tests were conducted with monodispersed and polydispersed aerosols composed of two particle types (sodium chloride, NaCl, and spark generated metal particles, which simulate particles found in welding fume) at three different steady-state concentration ranges (Low, <103; Medium, 103–104; and High, >104 particles/cm3). Particle number concentration, lung deposited surface area (LDSA) concentration, and mean size measured with the DM were compared to those measured with reference instruments, a scanning mobility particle sizer (SMPS) and a handheld condensation particle counter (CPC). Particle number concentrations measured with the DM were within 21% of those measured by reference instruments for polydisperse aerosols. Poorer agreement was observed for monodispersed aerosols (±35% for most tests and +130% for 300-nm NaCl). LDSA concentrations measured by the DM were 96% to 155% of those estimated with the SMPS. The geometric mean diameters measured with the DM were within 30% of those measured with the SMPS for monodispersed aerosols and within 25% for polydispersed aerosols (except for the case when the aerosol contained a substantial number of particles larger than 300 nm). The accuracy of the DM is reasonable for particles smaller than 300 nm but caution should be exercised when particles larger than 300 nm are present. PMID:23473056
20. Continuous measurements of aerosol particles in Arctic Russia and Finland
Asmi, Eija; Kondratyev, Vladimir; Brus, David; Lihavainen, Heikki; Laurila, Tuomas; Aurela, Mika; Hatakka, Juha; Viisanen, Yrjö; Reshetnikov, Alexander; Ivakhov, Victor; Uttal, Taneil; Makshtas, Alexander
2013-04-01
The Arctic and northern boreal regions of Eurasia are experiencing rapid environmental changes due to pressures by human activities. The largest anthropogenic climate forcings are due to aerosol particles and greenhouse gases (GHGs). The Arctic environment is highly sensitive to changes in aerosol concentrations or composition, largely due to the high surface reflectance for the most part of the year. Concentrations of aerosols in winter and spring Arctic are affected by 'Arctic Haze', a phenomenon suggested to arise from the transport of pollutants from lower latitudes and further strengthened by the strong stratification of the Arctic wintertime atmosphere. Sources and transport patterns of aerosols into the Arctic are, however, not fully understood. In order to monitor the changes within the Arctic region, as well as to understand the sources and feedback mechanisms, direct measurements of aerosols within the Arctic are needed. So far, direct year-round observations have been inadequate especially within the Russian side of the Arctic. This is the reason why a new climate observatory was founded in Tiksi, Russia. Tiksi meteorological observatory in northern Siberia (71o 36' N; 128o 53' E) on the shore of the Laptev Sea has been operating since 1930s. Recently, it was upgraded and joint in the network of the IASOA, in the framework of the International Polar Year Activity project. The project is run in collaboration between National Oceanic and Atmospheric Administration (NOAA) with the support of the National Science Foundation (NSF), Roshydromet (AARI and MGO units), government of the Republic of Sakha (Yakutia) and the Finnish Meteorological Institute (FMI). The research activities of FMI in Tiksi include e.g. continuous long-term measurements of aerosol physical properties, which have been successfully continued since summer 2010. These, together with the FMI measurements in Pallas station in northern Finland since 1999, provide important information on the
1. Mass absorption indices of various types of natural aerosol particles in the infrared.
PubMed
Fischer, K
1975-12-01
The mass absorption index of aerosol particles has been measured in the 2-17-microm wavelength region. The measurements were performed on films of aerosol particles that were collected by an automatic jet impactor at polluted and various uncontaminated remote sites. All but marine aerosols possess strong absorption bands in the transparent part of the atmospheric long-wave spectrum, indicating marked influence of aerosol particles on the radiation budget of the atmosphere.
2. Reconciling satellite aerosol optical thickness and surface fine particle mass through aerosol liquid water
Nguyen, Thien Khoi V.; Ghate, Virendra P.; Carlton, Annmarie G.
2016-11-01
Summertime aerosol optical thickness (AOT) over the southeast U.S. is sharply enhanced over wintertime values. This seasonal pattern is unique and of particular interest because temperatures there have not warmed over the past 100 years. Patterns in surface fine particle mass are inconsistent with satellite reported AOT. In this work, we attempt to reconcile the spatial and temporal distribution of AOT over the U.S. with particle mass measurements at the surface by examining trends in aerosol liquid water (ALW), a particle constituent that scatters radiation and affects satellite AOT but is removed in mass measurements at routine surface monitoring sites. We employ the thermodynamic model ISORROPIAv2.1 to estimate ALW mass concentrations at Interagency Monitoring of PROtected Visual Environments sites using measured ion mass concentrations and North American Regional Reanalysis meteorological data. Excellent agreement between Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations AOT and estimated ALW provides a plausible explanation for the discrepancies in the geographical patterns of AOT and aerosol mass measurements.
3. PARTICLE SIZE DISTRIBUTIONS FOR AN OFFICE AEROSOL
EPA Science Inventory
The article discusses an evaluation of the effect of percent outdoor air supplied and occupation level on the particle size distributions and mass concentrations for a typical office building. (NOTE: As attention has become focused on indoor air pollution control, it has become i...
4. Neural networks for aerosol particles characterization
Berdnik, V. V.; Loiko, V. A.
2016-11-01
Multilayer perceptron neural networks with one, two and three inputs are built to retrieve parameters of spherical homogeneous nonabsorbing particle. The refractive index ranges from 1.3 to 1.7; particle radius ranges from 0.251 μm to 56.234 μm. The logarithms of the scattered radiation intensity are used as input signals. The problem of the most informative scattering angles selection is elucidated. It is shown that polychromatic illumination helps one to increase significantly the retrieval accuracy. In the absence of measurement errors relative error of radius retrieval by the neural network with three inputs is 0.54%, relative error of the refractive index retrieval is 0.84%. The effect of measurement errors on the result of retrieval is simulated.
5. Glyoxal and Methylglyoxal in Atlantic Seawater and marine Aerosol Particles
van Pinxteren, Manuela; Herrmann, Hartmut
2014-05-01
The two α-dicarbonyls glyoxal (CHOCHO; GLY) and methylglyoxal (CH3COCHO; MGLY) have attracted increasing attention over the past years because of their potential role in secondary organic aerosol formation. Recently Sinreich et al. (2010) suggested the open ocean as an important (so far unknown) source for GLY in the atmosphere. To date, there are few available field data of these compounds in the marine area. In this study we present measurements of GLY and MGLY in seawater and marine aerosol particles sampled during a transatlantic Polarstern cruise in spring 2011. In seawater we especially investigated the sea surface microlayer (sampled with the glass plate technique) as it is the direct interface between ocean and atmosphere. Analytical measurements were based on derivatisation with o-(2,3,4,5,6-Pentafluorobenzyl)-hydroxylamine reagent, solvent extraction and GC-MS (SIM) analysis. The results show that GLY and MGLY are present in the sea surface microlayer of the ocean and corresponding bulkwater with average concentrations of 228 ng L-1 (GLY) and 196 ng L-1 (MGLY). Significant enrichment (factor of 4) of GLY and MGLY in the sea surface microlayer was found implying photochemical production of the two carbonyls though a clear connection to global radiation was not observed. On aerosol particles, both carbonyls were detected (average concentration 0.2 ng m-3) and are strongly connected to each other, suggesting similar formation mechanisms. Both carbonyls show a very good correlation with particulate oxalate, supporting the idea of a secondary formation of oxalic acid via GLY and MGLY. A slight correlation of the two carbonyls in the sea surface microlayer and in the aerosol particles was found at co-located sampling areas. In summary, the results of GLY and MGLY in marine aerosol particles and in the oceanic water give first insights towards interaction processes of these alpha dicarbonyls between ocean and atmosphere (van Pinxteren and Herrmann (2013
6. Morphology and Optical Properties of Mixed Aerosol Particles
Fard, Mehrnoush M.; Krieger, Ulrich; Rudich, Yinon; Marcolli, Claudia; Peter, Thomas
2015-04-01
Experiments and modeling studies have shown that deliquesced aerosols can be present not only as one-phase system containing organics, inorganic salts and water, but often as two-phase systems consisting of a predominantly organic and a predominantly inorganic aqueous phase 1,2. Recent laboratory studies conducted with model mixtures representing tropospheric aerosols1,2,3, secondary organic aerosol (SOA) from smog chamber experiments4, and field measurements5 suggest that liquid- liquid phase separations (LLPS) is indeed a common phenomenon in mixed organic/ ammonium sulfate (AS) particles. During LLPS, particles may adopt different morphologies mainly core- shell and partially engulfed. A core- shell configuration will have consequences for heterogeneous chemistry and hygroscopicity and as a result will alter the optical properties of the particles since the aqueous inorganic-rich phase will be totally enclosed by a probably highly viscous organic coating with low diffusivity for reactants and water. The primary objective of this project is to establish a method for investigating the morphology of mixed inorganic and absorbing organic compounds of atmospheric relevance and study their radiative properties before, during, and after phase transitions mainly during LLPS. This will be the first study looking into the radiative effect of LLPS in detail. In this first experiment, the behavior of single droplets of carminic acid (CA)/ AS/ H2O mixture was monitored during relative humidity (RH) cycles using optical microscopy. The same mixture particle was levitated in an electrodynamic balance (EDB) and the change in its absorption properties was measured at varying RH. We also intend to determine the occurrence of LLPS in accumulation- sized particles and the change in their absorption using a cavity ring down aerosol spectrometer. If LLPS alters the absorptive properties of the suggested model aerosols significantly, absorption measurements of accumulation mode
7. Accommodation coefficient of HOBr on deliquescent sodium bromide aerosol particles
Wachsmuth, M.; Gäggeler, H. W.; von Glasow, R.; Ammann, M.
2002-06-01
Uptake of HOBr on sea salt aerosol, sea salt brine or ice is believed to be a key process providing a source of photolabile bromine (Br2) and sustaining ozone depletion cycles in the Arctic troposphere. In the present study, uptake of HOBr on sodium bromide (NaBr) aerosol particles was investigated at an extremely low HOBr concentration of 300 cm-3 using the short-lived radioactive isotopes 83-86Br. Under these conditions, at maximum one HOBr molecule was taken up per particle. The rate of uptake was clearly limited by the mass accommodation coefficient, which was calculated to be 0.6 ± 0.2. This value is a factor of 10 larger than estimates used in earlier models. The atmospheric implications are discussed using the box model "MOCCA'', showing that the increase of the accommodation coefficient of HOBr by a factor of 10 only slightly affects net ozone loss, but significantly increases chlorine release.
8. Tracking Water Diffusion Fronts in a Highly Viscous Aerosol Particle
Bastelberger, Sandra; Krieger, Ulrich; Peter, Thomas
2016-04-01
Field measurements indicate that atmospheric secondary aerosol particles can be present in a highly viscous, glassy state [1]. In contrast to liquid state particles, the gas phase equilibration is kinetically limited and governed by condensed phase diffusion. In recent water diffusion experiments on highly viscous single aerosol particles levitated in an electrodynamic balance (EDB) we observed a characteristic shift behavior of the Mie whispering gallery modes (WGM) indicative of the changing radial structure of the particle, thus providing us with an experimental method to track the diffusion process inside the particle. When a highly viscous, homogeneous particle is exposed to an abrupt increase in relative humidity, the rapid gas phase diffusion and strong concentration dependence of the diffusion coefficient in the condensed phase lead to extremely steep water concentration gradients inside the particle, reminiscent of diffusion fronts. The resulting quasi step-like concentration profile motivates the introduction of a simple core-shell model describing the morphology of the non-equilibrium particle during humidification. The subsequent particle growth and reduction of the shell refractive index can be observed as red and blueshift behavior of the WGM, respectively. The shift pattern can be attributed to a core-shell radius ratio and particle radius derived from model calculations [2]. If supplemented with growth information obtained from the WGM redshift and thermodynamic equilibrium data, we can infer a comprehensive picture of the time evolution of the diffusion fronts in the framework of our core-shell model. The measured time dependent concentration profile is then compared with simulations solving the non-linear diffusion equation [3] [1] Virtanen, A., et al., Nature, 467, 824-827, 2010 [2] Kaiser, T., Schweiger, G., Computers in Physics, Vol. 7, No. 6, 682-686, Nov/Dec 1993 [3] Zobrist, B., Soonsin, V., Luo, B.P., Peter, T. et al., Phys. Chem. Chem
9. An amorphous solid state of biogenic secondary organic aerosol particles.
PubMed
Virtanen, Annele; Joutsensaari, Jorma; Koop, Thomas; Kannosto, Jonna; Yli-Pirilä, Pasi; Leskinen, Jani; Mäkelä, Jyrki M; Holopainen, Jarmo K; Pöschl, Ulrich; Kulmala, Markku; Worsnop, Douglas R; Laaksonen, Ari
2010-10-14
Secondary organic aerosol (SOA) particles are formed in the atmosphere from condensable oxidation products of anthropogenic and biogenic volatile organic compounds (VOCs). On a global scale, biogenic VOCs account for about 90% of VOC emissions and of SOA formation (90 billion kilograms of carbon per year). SOA particles can scatter radiation and act as cloud condensation or ice nuclei, and thereby influence the Earth's radiation balance and climate. They consist of a myriad of different compounds with varying physicochemical properties, and little information is available on the phase state of SOA particles. Gas-particle partitioning models usually assume that SOA particles are liquid, but here we present experimental evidence that they can be solid under ambient conditions. We investigated biogenic SOA particles formed from oxidation products of VOCs in plant chamber experiments and in boreal forests within a few hours after atmospheric nucleation events. On the basis of observed particle bouncing in an aerosol impactor and of electron microscopy we conclude that biogenic SOA particles can adopt an amorphous solid-most probably glassy-state. This amorphous solid state should provoke a rethinking of SOA processes because it may influence the partitioning of semi-volatile compounds, reduce the rate of heterogeneous chemical reactions, affect the particles' ability to accommodate water and act as cloud condensation or ice nuclei, and change the atmospheric lifetime of the particles. Thus, the results of this study challenge traditional views of the kinetics and thermodynamics of SOA formation and transformation in the atmosphere and their implications for air quality and climate.
10. Hydrolysis of organonitrate functional groups in aerosol particles
SciTech Connect
Liu, Shang; Shilling, John E.; Song, Chen; Hiranuma, Naruki; Zaveri, Rahul A.; Russell, Lynn M.
2012-10-19
Organonitrate (ON) groups are important substituents in secondary organic aerosols. Model simulations and laboratory studies indicate a large fraction of ON groups in aerosol particles, but much lower quantities are observed in the atmosphere. Hydrolysis of ON groups in aerosol particles has been proposed recently. To test this hypothesis, we simulated formation of ON molecules in a reaction chamber under a wide range of relative humidity (0% to 90%). The mass fraction of ON groups (5% to 20% for high-NOx experiments) consistently decreased with increasing relative humidity, which was best explained by hydrolysis of ON groups at a rate of 4 day-1 (lifetime of 6 hours) for reactions under relative humidity greater than 20%. In addition, we found that secondary nitrogen-containing molecules absorb light, with greater absorption under dry and high-NOx conditions. This work provides the first evidence for particle-phase hydrolysis of ON groups, a process that could substantially reduce ON group concentration in the atmosphere.
11. Aerosol particles from tropical convective systems: 2. Cloud bases
Kojima, Tomoko; Buseck, Peter R.; Reeves, J. Michael
2005-05-01
Aerosol particles were collected at the altitudes of cloud bases during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) and analyzed using transmission electron microscopy. The particles consist of ammonium sulfate (45-90% by number), sea salt (5-45%), mineral dust (1-20%), and anthropogenic materials such as soot and fly ash (<3%). Ammonium sulfate particles have rather uniform, submicron sizes (mostly 0.5 μm across). Sea-salt particles are larger, apparently having been deliquesced. However, submicron particles are also common. Many contain Na and mixed cation sulfates in addition to NaCl. Mineral dust consists largely of tabular clay particles. Samples from the 28 July flight contain much mineral dust, probably because of transport from the Saharan Desert. Aggregates of sea salt and mineral dust, ammonium sulfate, and soot particles are common. Such mixed aggregates are especially abundant in in-cloud samples. Cirrus samples from CRYSTAL-FACE contain many H2SO4 droplets (Kojima et al., 2004), but acidic sulfate particles are rare at the altitudes of cloud bases. H2SO4 probably formed at higher altitudes through oxidation of SO2 in cloud droplets. Sea salt and mineral dust have been reported to be abundant in cloud particles collected using a counterflow virtual impactor (Cziczo et al., 2004), suggesting that these particles were incorporated into the convective systems from the cloud bases and akted as ice nuclei while being vertically transported.
12. Individual aerosol particles from biomass burning in southern Africa: 2, Compositions and aging of inorganic particles
Li, Jia; Pósfai, MiháLy; Hobbs, Peter V.; Buseck, Peter R.
2003-07-01
Individual aerosol particles collected over southern Africa during the SAFARI 2000 field study were studied using transmission electron microscopy and field-emission scanning electron microscopy. The sizes, shapes, compositions, mixing states, surface coatings, and relative abundances of aerosol particles from biomass burning, in boundary layer hazes, and in the free troposphere were compared, with emphasis on aging and reactions of inorganic smoke particles. Potassium salts and organic particles were the predominant species in the smoke, and most were internally mixed. More KCl particles occur in young smoke, whereas more K2SO4 and KNO3 particles were present in aged smoke. This change indicates that with the aging of the smoke, KCl particles from the fires were converted to K2SO4 and KNO3 through reactions with sulfur- and nitrogen-bearing species from biomass burning as well as other sources. More soot was present in smoke from flaming grass fires than bush and wood fires, probably due to the predominance of flaming combustion in grass fires. The high abundance of organic particles and soluble salts can affect the hygroscopic properties of biomass-burning aerosols and therefore influence their role as cloud condensation nuclei. Particles from biomass burning were important constituents of the regional hazes.
13. Aerosol Particle Property Comparisons Between MISR and AERONET Retrieved Values
Gaitley, B. J.; Kahn, R. A.
2005-12-01
Aerosol optical depth (AOT) data from the Multi-angle ImagingSpectroRadiometer (MISR) instrument aboard the NASA Earth Observing System's Terra satellite have already been systematically compared with ground-based data from the AERONET network. As a result of that study, MISR data are now being reprocessed with improved aerosol algorithms and aerosol models. The follow-on study reported here systematically compares MISR and AERONET particle micro-physical properties. This project is currently underway. Our goal is to use the statistical power of numerous AERONET measurements to map the behavior of the MISR property retrievals, identify strength and surprises in the MISR data, and use this information both to refine further the MISR retrieval algorithms and to assess the likely error envelopes in the MISR products. Multi-year data from 36 carefully chosen sites having good long-term measurement records are stratified by broad classes of aerosol air mass types: maritime, biomass burning, desert dust, pollution, and continental aerosols. Available AERONET spectral AOT measurements for two-hour windows around MISR overpass times are interpolated to MISR wavelengths and averaged, and AOT variability over the two-hour window is noted. Sky-scan AERONET data, taken only once an hour, are also were interpolated to MISR wavelengths, and are averaged over a four-hour window provided the variability is smaller than MISR sensitivity to particle properties based on previous work. MISR retrievals over the 17.6 km standard retrieval regions that include the AERONET sites are preferentially used for the comparison. The MISR measurements are averages of over all "successful" aerosol type models in the MISR algorithm climatology, where success is measured by the degree to which multi-angle, multi-spectral top-of-atmosphere radiances match modeled radiances, using several chi-squared tests. Angstrom exponent, single scattering albedo, and size distribution mean values and variance
14. The relation between aerosol particles and lightning in Mexico
Kucienska, B.; Cervantes Villa, J. S.; Raga, G. B.
2013-05-01
The analysis of lightning activity registered by the World Wide Lightning Location Network and aerosol optical depth (AOD) derived from the Moderate Resolution Imaging Spectroradiometer indicate that spatial and temporal variations in cloud-to-ground lightning density over Mexico are linked to variations in aerosol amounts. Average lightning activity registered on days with moderate AOD is higher than that registered on days with low AOD for most of the continental areas and coastal maritime regions. This finding could be explained either by the aerosol effect on thunderstorms electrical activity or by a similar influence of meteorological conditions on both lightning and AOD. Analysis of temporal variations of electrical activity show that over large continental areas a significant lightning density is observed during spring, at the very beginning of rainy seasons. In May, when rainfall is relatively low, an exceptionally high lightning activity is also registered over the Pacific, in the region located south to Isthmus of Tehuantepec. This signal of high lightning density propagates hundreds of kilometers away from the coast. We hypothesize that high lightning activity during spring observed over both continental and oceanic regions is linked to the presence of aerosol particle generated by biomass burning which peaks in April and May.
15. Measurements of Primary Biogenic Aerosol Particles with an Ultraviolet Aerodynamic Particle Sizer (UVAPS) During AMAZE-08
Wollny, A. G.; Garland, R.; Pöschl, U.
2008-12-01
Biogenic aerosols are ubiquitous in the Earth's atmosphere and they influence atmospheric chemistry and physics, the biosphere, climate, and public health. They play an important role in the spread of biological organisms and reproductive materials, and they can cause or enhance human, animal, and plant diseases. Moreover, they influence the Earth's energy budget by scattering and absorbing radiation, and they can initiate the formation of clouds and precipitation as cloud condensation and ice nuclei. The composition, abundance, and origin of biogenic aerosol particles and components are, however, still not well understood and poorly quantified. Prominent examples of primary biogenic aerosol particles, which are directly emitted from the biosphere to the atmosphere, are pollen, bacteria, fungal spores, viruses, and fragments of animals and plants. During the AMazonian Aerosol CharacteriZation Experiment (AMAZE-08) a large number of aerosol and gas-phase measurements were taken on a remote site close to Manaus, Brazil, during a period of five weeks in February and March 2008. The presented study is focused on data from an ultraviolet aerodynamic particle sizer (UVAPS, TSI inc.) that has been deployed for the first time in Amazonia. In this instrument, particle counting and aerodynamic sizing over the range of 0.5-20 μm are complemented by the measurement of UV fluorescence at 355 nm (excitation) and 420-575 nm (emission), respectively. Fluorescence at these wavelengths is characteristic for reduced pyridine nucleotides (e.g., NAD(P)H) and for riboflavin, which are specific for living cells. Thus particles exhibiting fluorescence signals can be regarded as 'viable aerosols' or 'fluorescent bioparticles' (FBAP), and their concentration can be considered as lower limit for the actual abundance of primary biogenic aerosol particles. First data analyses show a pronounced peak of FBAP at diameters around 2-3 μm. In this size range the biogenic particle fraction was
16. Scanning Transmission X-ray microscopy Imaging of Aerosol Particles
Gilles, M. K.; Kilcoyne, A.; Tyliszczak, T.; Shuh, D. K.; Fakra, S.; Robinson, M.; Chase, K.
2003-12-01
Scanning transmission x-ray microscopes (STXM) are used to image a diversity of carbon and metal containing items such as biofilms in soils, magnetic materials, polymers and meteorites. Studies on particles collected on SiO2 filters from biomass burns in Flagstaff, Arizona and individual aerosols collected in South Africa on TEM grids are underway at beamlines 5.3.2 and 11.0.2 at the Advanced Light Source of Lawrence Berkeley National Laboratory. Sub micron particles are imaged in the transmission mode over the energy range of 280 - 1900 eV. Spectromicroscopic studies on individual particles using near edge x-ray absorption fine structure (NEXAFS) probe multiple species within or on the same particle. In (STXM) an X-ray beam is focused with a zone plate onto a sample and the transmitted radiation is detected. Since the signal is obtained in the transmission mode, optically thin samples are required. Hence, atmospheric aerosols with submicron thickness and diameter are well suited for this method. Near edge spectra of various elements were scanned in step sizes from 0.1-0.5 eV around characteristic absorption edges, creating 2 dimensional images at each energy. While STXM images are taken with a lower spatial resolution (currently 40 nm) than microscopies such as scanning electron microscopy, transmission electron microscopy, and atomic force microscopy, detailed chemical information with spatial distributions, and oxidation states is obtained. A particular focus of this work is to obtain more detailed information on the type of carbons, multiply, or singly bonded and whether or not carbon is bonded to oxygen. The ultimate goal is discrimination between organic and black carbon within individual aerosol particles and determining if organic carbon, black carbon, and metal species are distributed homogeneously throughout aerosol particles. Initial scans of the samples from Flagstaff show spectral evidence of aromatic carbon, without distinct C=O signatures. NEXAFS
17. Individual Aerosol Particle Types Produced by Savanna Burning
Posfai, M.; Simonics, R.; Li, J.; Hobbs, P. V.; Buseck, P. R.; Buseck, P. R.
2001-12-01
We used analytical transmission electron microscopy (TEM) to study individual aerosol particles that were collected on the University of Washington Convair-580 research aircraft over southern Africa during the Safari2000 Dry Season Experiment. Our goals were to study the compositions, morphologies, and mixing states of carbonaceous particles, in order to better understand the physical and chemical properties of biomass smoke on the individual-particle level. The compositions of single particles were determined using energy-dispersive x-ray spectrometry (EDS) and electron energy-loss spectroscopy (EELS). Energy-loss maps obtained with the TEM are useful for studying the spatial distribution of light elements such as carbon within the particles; thus, they provide a detailed picture of complex particles. Carbonaceous particles were assigned into three main groups on the basis of morphology and composition: "organic particles with inorganic inclusions," "tar balls," and "soot." Soot is recognized by its characteristic morphology and microstructure. The distinction between "organic particles with inorganic inclusions" and "tar balls" is somewhat arbitrary, since the two criteria that are used for their distinction (composition and aspect ratio) change continually. The relative concentrations of the three major particle types vary with the type of fire and distance from fire. In the plume of a smoldering fire west of Beria (August 31) the relative concentration of tar balls increased with aging of the plume. Tar balls have a fairly narrow size distribution with a maximum between 100 and 200 nm (diameter). The inorganic K-salt inclusions (KCl, K2SO4, KNO3) within "organic particles" should make these particles hygroscopic, regardless of the properties of the organic compounds. Aging causes the conversion of KCl into K2SO4, KNO3. Aerosol production from flaming and smoldering fires was compared over Kruger National Park on August 17; more soot and more Cl-rich inclusions
18. Physicochemical characterization of Capstone depleted uranium aerosols I: uranium concentration in aerosols as a function of time and particle size.
PubMed
Parkhurst, Mary Ann; Cheng, Yung Sung; Kenoyer, Judson L; Traub, Richard J
2009-03-01
During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing DU were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol sample was first quantified by radioanalytical methods, and selected samples, primarily those from the cyclone separator grit chambers, were analyzed radiochemically. Deposition occurred inside the vehicles as particles settled on interior surfaces. Settling rates of uranium from the aerosols were evaluated using filter cassette samples that collected aerosol as total mass over eight sequential time intervals. A moving filter was used to collect aerosol samples over time, particularly within the first minute after a shot. The results demonstrate that the peak uranium concentration in the aerosol occurred in the first 10 s after perforation, and the concentration decreased in the Abrams tank shots to about 50% within 1 min and to less than 2% after 30 min. The initial and maximum uranium concentrations were lower in the Bradley vehicle than those observed in the Abrams tank, and the concentration levels decreased more slowly. Uranium mass concentrations in the aerosols as a function of particle size were evaluated using samples collected in a cyclone sampler, which collected aerosol continuously for 2 h after perforation. The percentages of uranium mass in the cyclone separator stages ranged from 38 to 72% for the Abrams tank with conventional armor. In most cases, it varied with particle size, typically with less uranium associated with the smaller particle sizes. Neither the Abrams tank with DU armor nor the Bradley vehicle results were specifically correlated with particle size and can best be represented by their average uranium mass concentrations of 65
19. Relationship between aerosol oxidation level and hygroscopic properties of laboratory generated secondary organic aerosol (SOA) particles
Massoli, P.; Lambe, A.; Ahern, A.; Williams, L. R.; Ehn, M.; Mikkila, J.; Canagaratna, M.; Brune, W. H.; Onasch, T. B.; Jayne, J.; Petdjd, T. T.; Kulmala, M. T.; Laaksonen, A.; Kolb, C. E.; Davidovits, P.; Worsnop, D. R.
2010-12-01
Laboratory experiments investigated the relationship between degree of oxidation and hygroscopic properties of secondary organic aerosol (SOA) particles. The hygroscopic growth factor (HGF), the CCN activity (κCCN) and the degree of aerosol oxidation (represented by the atomic O:C ratio) were measured for α-pinene, 1,3,5-trimethylbenzene (TMB), m-xylene and α pinene/m-xylene mixture SOA generated via OH radical oxidation in an aerosol flow reactor. Our results show that both HGF and κCCN increase with O:C. The TMB and m-xylene SOA were, respectively, the least and most hygroscopic of the system studied. An average HGF of 1.25 and a κCCN of 0.2 were measured at O:C of 0.65, in agreement with results reported for ambient data. The HGF based κ(κHGF) under predicted the κCCN values of 20 to 50% for all but the TMB SOA. Within the limitations of instrumental capabilities, we define the extent to which the hygroscopic properties of SOA particles can be predicted from their oxidation level and provide parameterizations suitable for interpreting ambient data.
20. Susceptibility of Tribolium confusum (Coleoptera: Tenebrionidae) to pyrethrin aerosol: effects of aerosol particle size, concentration, and exposure conditions
Technology Transfer Automated Retrieval System (TEKTRAN)
A series of laboratory studies were conducted to assess effect of droplet size on efficacy of pyrethrin aerosol against adults of Tribolium confusum Jacqueline DuVal, the confused flour beetle. A vertical flow aerosol exposure chamber that generated a standardized particle size diameter was used for...
1. Atmospheric Condensational Properties of Ultrafine Chain and Fractal Aerosol Particles
NASA Technical Reports Server (NTRS)
Marlow, William H.
1997-01-01
The purpose for the research sponsored by this grant was to lay the foundations for qualitative understanding and quantitative description of the equilibrium vapor pressure of water vapor over the irregularly shaped, carbonaceous particles that are present in the atmosphere. This work apparently was the first systematic treatment of the subject. Research was conducted in two complementary components: 1. Calculations were performed of the equilibrium vapor pressure of water over particles comprised of aggregates of spheres in the 50-200 nm radius range. The purposes of this work were two-fold. First, since no systematic treatment of this subject had previously been conducted, its availability would be directly useful for quantitative treatment for a limited range of atmospheric aerosols. Second, it would provide qualitative indications of the effects of highly irregular particle shape on equilibrium vapor pressure of aggregates comprised of smaller spheres.
2. A New Electrospray Aerosol Generator with High Particle Transmission Efficiency
PubMed Central
Fu, Huijing; Patel, Anand C.; Holtzman, Michael J.; Chen, Da-Ren
2012-01-01
A new single-capillary electrospray (ES) aerosol generator has been developed for monodisperse particle production with maximal transmission efficiency. The new generator consists of both a spray chamber in a point-to-orifice-plate configuration and a charge reduction chamber that can hold up to 4 Nuclespot ionizers (Model P-2042, NRD Inc.). The 2 chambers are partitioned by an orifice plate. To optimize the particle transmission efficiency of the prototype, a systematic study was performed on the generator by varying the system setup and operation. Two key dimensions of the generator setup, the orifice diameter and the distance from the capillary tip to the orifice plate, were varied. Fluorescence analysis was applied to characterize the loss of ES-generated particles at different locations of the prototype. It was found that particle loss in the generator could be reduced by either increasing the orifice diameter or decreasing the distance between the capillary tip and the orifice plate. Increasing either the total radioactivity of the ionizers or the flowrate of the particle carrier gas also further decreased the particle loss in the system. The maximum particle transmission efficiency of 88.0% was obtained with the spray chamber fully opened to the charge reduction chamber, the capillary tip at the same level as the orifice plate, and 4 bipolar ionizers installed. PMID:22829715
3. Method and apparatus for aerosol particle absorption spectroscopy
DOEpatents
Campillo, Anthony J.; Lin, Horn-Bond
1983-11-15
A method and apparatus for determining the absorption spectra, and other properties, of aerosol particles. A heating beam source provides a beam of electromagnetic energy which is scanned through the region of the spectrum which is of interest. Particles exposed to the heating beam which have absorption bands within the band width of the heating beam absorb energy from the beam. The particles are also illuminated by light of a wave length such that the light is scattered by the particles. The absorption spectra of the particles can thus be determined from an analysis of the scattered light since the absorption of energy by the particles will affect the way the light is scattered. Preferably the heating beam is modulated to simplify the analysis of the scattered light. In one embodiment the heating beam is intensity modulated so that the scattered light will also be intensity modulated when the particles absorb energy. In another embodiment the heating beam passes through an interferometer and the scattered light reflects the Fourier Transform of the absorption spectra.
4. Comparison of the DiSCmini aerosol monitor to a handheld condensation particle counter and a scanning mobility particle sizer for submicrometer sodium chloride and metal aerosols.
PubMed
Mills, Jessica B; Park, Jae Hong; Peters, Thomas M
2013-01-01
We evaluated the robust, lightweight DiSCmini (DM) aerosol monitor for its ability to measure the concentration and mean diameter of submicrometer aerosols. Tests were conducted with monodispersed and polydispersed aerosols composed of two particle types (sodium chloride [NaCl] and spark-generated metal particles, which simulate particles found in welding fume) at three different steady-state concentration ranges (Low, <10(3); Medium, 10(3)-10(4); and High, >10(4) particles/cm(3)). Particle number concentration, lung deposited surface area (LDSA) concentration, and mean size measured with the DM were compared with those measured with reference instruments, a scanning mobility particle sizer (SMPS), and a handheld condensation particle counter (CPC). Particle number concentrations measured with the DM were within 16% of those measured by the CPC for polydispersed aerosols. Poorer agreement was observed for monodispersed aerosols (±35% for most tests and +101% for 300-nm NaCl). LDSA concentrations measured by the DM were 96% to 155% of those estimated with the SMPS. The geometric mean diameters measured with the DM were within 30% of those measured with the SMPS for monodispersed aerosols and within 25% for polydispersed aerosols (except for the case when the aerosol contained a substantial number of particles larger than 300 nm). The accuracy of the DM is reasonable for particles smaller than 300 nm, but caution should be exercised when particles larger than 300 nm are present. [Supplementary materials are available for this article. Go to the publisher's online edition of the Journal of Occupational and Environmental Hygiene for the following free supplemental resources: manufacturer-reported capabilities of instruments used, and information from the SMPS measurements for polydispersed test particles.].
5. Morphology and Optical Properties of Mixed Aerosol Particles
Fard, Mehrnoush M.; Krieger, Ulrich; Rudich, Yinon; Marcolli, Claudia; Peter, Thomas
2016-04-01
Experiments and modeling studies have shown that deliquesced aerosols can exist not only as one-phase system containing organics, inorganic salts and water, but often as two-phase systems consisting of a predominantly organic and a predominantly inorganic aqueous phase (1,2). Recent laboratory studies conducted with model mixtures representing tropospheric aerosols (1,2,3), secondary organic aerosol (SOA) from smog chamber experiments (4), and field measurements (5) suggest that liquid-liquid phase separations (LLPS) is indeed a common phenomenon in mixed organic/ inorganic particles. During LLPS, particles may adopt different morphologies mainly core-shell and partially engulfed. A core-shell configuration will have consequences for heterogeneous chemistry and hygroscopicity and as a result will alter the optical properties of the particles in particular for organic phases containing absorbing molecules, e.g. brown carbon. The primary objective of this project is to establish a method for investigating the morphology of mixed inorganic and absorbing organic compounds of atmospheric relevance and study their radiative properties before, during, and after phase transitions mainly during LLPS. This will be the first study looking into the radiative effect of LLPS in detail. Our ternary model system consist of ammonium sulfate (AS)/ Polyethylene Glycol (PEG)/ and water (H2O). Carminic acid (CA) was added as a proxy for an absorbing organic compound to the system. The behavior of single droplets of above ternary mixture was monitored during relative humidity (RH) cycles using optical microscopy. The same ternary mixture particle was levitated in an electrodynamic balance (EDB) and the change in its absorption properties was measured at varying RH. In addition, Mie-code modeling is used to predict the absorption efficiency of the same ternary system and the result will be compared with the data obtained from EDB experiment. We also intend to determine the occurrence of
6. Gas uptake and chemical aging of semisolid organic aerosol particles.
PubMed
Shiraiwa, Manabu; Ammann, Markus; Koop, Thomas; Pöschl, Ulrich
2011-07-05
Organic substances can adopt an amorphous solid or semisolid state, influencing the rate of heterogeneous reactions and multiphase processes in atmospheric aerosols. Here we demonstrate how molecular diffusion in the condensed phase affects the gas uptake and chemical transformation of semisolid organic particles. Flow tube experiments show that the ozone uptake and oxidative aging of amorphous protein is kinetically limited by bulk diffusion. The reactive gas uptake exhibits a pronounced increase with relative humidity, which can be explained by a decrease of viscosity and increase of diffusivity due to hygroscopic water uptake transforming the amorphous organic matrix from a glassy to a semisolid state (moisture-induced phase transition). The reaction rate depends on the condensed phase diffusion coefficients of both the oxidant and the organic reactant molecules, which can be described by a kinetic multilayer flux model but not by the traditional resistor model approach of multiphase chemistry. The chemical lifetime of reactive compounds in atmospheric particles can increase from seconds to days as the rate of diffusion in semisolid phases can decrease by multiple orders of magnitude in response to low temperature or low relative humidity. The findings demonstrate that the occurrence and properties of amorphous semisolid phases challenge traditional views and require advanced formalisms for the description of organic particle formation and transformation in atmospheric models of aerosol effects on air quality, public health, and climate.
7. Method for determining aerosol particle size, device for determining aerosol particle size
SciTech Connect
Novick, Vincent J.
1997-12-01
A method for determining the mass median diameter D of particles contained in a fluid is provided wherein the data of the mass of a pre-exposed and then a post-exposed filter is mathematically combined with data concerning the pressure differential across the same filter before and then after exposure to a particle-laden stream. A device for measuring particle size is also provided wherein the device utilizes the above-method for mathematically combining the easily quantifiable data.
8. SAGE II aerosol validation: selected altitude measurements, including particle micromeasurements.
PubMed
Oberbeck, V R; Livingston, J M; Russell, P B; Pueschel, R F; Rosen, J N; Osborn, M T; Kritz, M A; Snetsinger, K G; Ferry, G V
1989-06-20
Correlative aerosol measurements taken at a limited number of altitudes during coordinated field experiments are used to test the validity of particulate extinction coefficients derived from limb path solar radiance measurements taken by the Stratospheric Aerosol and Gas Experiment (SAGE) II Sun photometer. In particular, results are presented from correlative measurement missions that were conducted during January 1985, August 1985, and July 1986. Correlative sensors included impactors, laser spectrometers, and filter samplers aboard an U-2-airplane, an upward pointing lidar aboard a P-3 airplane, and balloon-borne optical particle counters (dustsondes). The main body of this paper focuses on the July 29, 1986, validation experiment, which minimized the many difficulties (e.g., spatial and temporal inhomogeneities, imperfect coincidences) that can complicate the validation process. On this day, correlative aerosol measurements taken at an altitude of 20.5 km agreed with each other within their respective uncertainties, and particulate extinction values calculated at SAGE II wavelengths from these measurements validated corresponding SAGE II values. Additional validation efforts on days when measurement and logistical conditions were much less favorable for validation are discussed in an appendix.
9. Experimental Determination of Chemical Diffusion within Secondary Organic Aerosol Particles
SciTech Connect
Abramson, Evan H.; Imre, D.; Beranek, Josef; Wilson, Jacqueline; Zelenyuk, Alla
2013-02-28
Formation, properties, transformations, and temporal evolution of secondary organic aerosols (SOA) particles strongly depend on particle phase. Recent experimental evidence from a number of groups indicates that SOA is in a semi-solid phase, the viscosity of which remained unknown. We find that when SOA is made in the presence of vapors of volatile hydrophobic molecules the SOA particles absorb and trap them. Here, we illustrate that it is possible to measure the evaporation rate of these molecules that is determined by their diffusion in SOA, which is then used to calculate a reasonably accurate value for the SOA viscosity. We use pyrene as a tracer molecule and a-pinene SOA as an illustrative case. It takes ~24 hours for half the pyrene to evaporate to yield a viscosity of 10^8 Pa s for a-pinene. This viscosity is consistent with measurements of particle bounce and evaporation rates. We show that viscosity of 10^8 Pa s implies coalescence times of minutes, consistent with the findings that SOA particles are spherical. Similar measurements on aged SOA particles doped with pyrene yield a viscosity of 10^9 Pa s, indicating that hardening occurs with time, which is consistent with observed decrease in water uptake and evaporation rate with aging.
10. EVALUATION OF ACOUSTIC FORCES ON A PARTICLE IN AEROSOL MEDIUM
SciTech Connect
Lee, S; Richard Dimenna, R
2007-09-27
The acoustic force exerted on a solid particle was evaluated to develop a fundamental understanding of the critical physical parameters or constraints affecting particle motion and capture in a collecting device. The application of an acoustic force to the collection of a range of submicron-to-micron particles in a highly turbulent airflow stream laden with solid particles was evaluated in the presence of other assisting and competing forces. This scoping estimate was based on the primary acoustic force acting directly on particles in a dilute aerosol system, neglecting secondary interparticle effects such as agglomeration of the sub-micron particles. A simplified analysis assuming a stable acoustic equilibrium with an infinite sound speed in the solid shows that for a solid-laden air flow in the presence of a standing wave, particles will move toward the nearest node. The results also show that the turbulent drag force on a 1-{micro}m particle resulting from eddy motion is dominant when compared with the electrostatic force or the ultrasonic acoustic force. At least 180 dB acoustic pressure level at 1 MHz is required for the acoustic force to be comparable to the electrostatic or turbulent drag forces in a high-speed air stream. It is noted that particle size and pressure amplitude are dominant parameters for the acoustic force. When acoustic pressure level becomes very large, the acoustic energy will heat up the surrounding air medium, which may cause air to expand. With an acoustic power of about 600 watts applied to a 2000-lpm air flow, the air temperature can increase by as much as 15 C at the exit of the collector.
11. Relationship between aerosol oxidation level and hygroscopic properties of laboratory generated secondary organic aerosol (SOA) particles
Massoli, P.; Lambe, A. T.; Ahern, A. T.; Williams, L. R.; Ehn, M.; Mikkilä, J.; Canagaratna, M. R.; Brune, W. H.; Onasch, T. B.; Jayne, J. T.; Petäjä, T.; Kulmala, M.; Laaksonen, A.; Kolb, C. E.; Davidovits, P.; Worsnop, D. R.
2010-12-01
Laboratory experiments investigated the relationship between oxidation level and hygroscopic properties of secondary organic aerosol (SOA) particles generated via OH radical oxidation in an aerosol flow reactor. The hygroscopic growth factor at 90% RH (HGF90%), the CCN activity ($\\kappa$ORG,CCN) and the level of oxidation (atomic O:C ratio) of the SOA particles were measured. Both HGF90% and $\\kappa$ORG,CCN increased with O:C; the HGF90% varied linearly with O:C, while $\\kappa$ORG,CCN mostly followed a nonlinear trend. An average HGF90% of 1.25 and $\\kappa$ORG,CCN of 0.19 were measured for O:C of 0.65, in agreement with results reported for ambient data. The $\\kappa$ORG values estimated from the HGF90% ($\\kappa$ORG,HGF) were 20 to 50% lower than paired $\\kappa$ORG,CCN values for all SOA particles except 1,3,5-trimethylbenzene (TMB), the least hygroscopic of the SOA systems. Within the limitations of instrumental capabilities, we show that differences in hygroscopic behavior among the investigated SOA systems may correspond to differences in elemental composition.
12. Multiphase OH oxidation kinetics of organic aerosol: The role of particle phase state and relative humidity
Slade, Jonathan H.; Knopf, Daniel A.
2014-07-01
Organic aerosol can exhibit different phase states in response to changes in relative humidity (RH), thereby influencing heterogeneous reaction rates with trace gas species. OH radical uptake by laboratory-generated levoglucosan and methyl-nitrocatechol particles, serving as surrogates for biomass burning aerosol, is determined as a function of RH. Increasing RH lowers the viscosity of amorphous levoglucosan aerosol particles enabling enhanced OH uptake. Conversely, OH uptake by methyl-nitrocatechol aerosol particles is suppressed at higher RH as a result of competitive coadsorption of H2O that occupies reactive sites. This is shown to have substantial impacts on organic aerosol lifetimes with respect to OH oxidation. The results emphasize the importance of organic aerosol phase state to accurately describe the multiphase chemical kinetics and thus chemical aging process in atmospheric models to better represent the evolution of organic aerosol and its role in air quality and climate.
13. Dynamics of Aerosol Particles in Stationary, Isotropic Turbulence
NASA Technical Reports Server (NTRS)
Collins, Lance R.; Meng, Hui
2004-01-01
A detailed study of the dynamics of sub-Kolmogorov-size aerosol particles in stationary isotropic turbulence has been performed. The study combined direct numerical simulations (DNS; directed by Prof. Collins) and high-resolution experimental measurements (directed by Prof. Meng) under conditions of nearly perfect geometric and parametric overlap. The goal was to measure the accumulation of particles in low-vorticity regions of the flow that arises from the effect commonly referred to as preferential concentration. The grant technically was initiated on June 13, 2000; however, funding was not available until July 11, 2000. The grant was originally awarded to Penn State University (numerical simulations) and SUNY-Buffalo (experiments); however, Prof. Collins effort was moved to Cornell University on January 2002 when he joined that university. He completed the study there. A list of the specific tasks that were completed under this study is presented.
14. Real-Time Detection Method And System For Identifying Individual Aerosol Particles
DOEpatents
Gard, Eric Evan; Fergenson, David Philip
2005-10-25
A method and system of identifying individual aerosol particles in real time. Sample aerosol particles are compared against and identified with substantially matching known particle types by producing positive and negative test spectra of an individual aerosol particle using a bipolar single particle mass spectrometer. Each test spectrum is compared to spectra of the same respective polarity in a database of predetermined positive and negative spectra for known particle types and a set of substantially matching spectra is obtained. Finally the identity of the individual aerosol particle is determined from the set of substantially matching spectra by determining a best matching one of the known particle types having both a substantially matching positive spectrum and a substantially matching negative spectrum associated with the best matching known particle type.
15. Measurement of the nucleation of atmospheric aerosol particles.
PubMed
Kulmala, Markku; Petäjä, Tuukka; Nieminen, Tuomo; Sipilä, Mikko; Manninen, Hanna E; Lehtipalo, Katrianne; Dal Maso, Miikka; Aalto, Pasi P; Junninen, Heikki; Paasonen, Pauli; Riipinen, Ilona; Lehtinen, Kari E J; Laaksonen, Ari; Kerminen, Veli-Matti
2012-09-01
The formation of new atmospheric aerosol particles and their subsequent growth have been observed frequently at various locations all over the world. The atmospheric nucleation rate (or formation rate) and growth rate (GR) are key parameters to characterize the phenomenon. Recent progress in measurement techniques enables us to measure atmospheric nucleation at the size (mobility diameter) of 1.5 (±0.4) nm. The detection limit has decreased from 3 to 1 nm within the past 10 years. In this protocol, we describe the procedures for identifying new-particle-formation (NPF) events, and for determining the nucleation, formation and growth rates during such events under atmospheric conditions. We describe the present instrumentation, best practices and other tools used to investigate atmospheric nucleation and NPF at a certain mobility diameter (1.5, 2.0 or 3.0 nm). The key instruments comprise devices capable of measuring the number concentration of the formed nanoparticles and their size, such as a suite of modern condensation particle counters (CPCs) and air ion spectrometers, and devices for characterizing the pre-existing particle number concentration distribution, such as a differential mobility particle sizer (DMPS). We also discuss the reliability of the methods used and requirements for proper measurements and data analysis. The time scale for realizing this procedure is 1 year.
16. Phosphorus-bearing Aerosol Particles From Volcanic Plumes
Obenholzner, J. H.; Schroettner, H.; Poelt, P.; Delgado, H.; Caltabiano, T.
2003-12-01
Particles rich in P or bulk geochemical data of volcanic aerosol particles showing high P contents are known from many volcanic plumes (Stanton, 1994; Obenholzner et al., 2003). FESEM/EDS analysis of individual particles obtained from the passively degassing plume of Popocatepetl volcano, Mx. (1997) and from the plume of Stromboli (May 2003) show P frequently. Even at the high resolution of the FESEM, euhedral apatite crystals could not be observed. At Popocatepetl (1997) spherical Ca-P-O particles are common. Fluffy, fractal or botryoidal particles also can contain EDS-detectable amounts of P. The EDS spectrum of such particles can comprise various elements. However most particles show P, S and Cl. P-S and P-S-metal species are known in chemistry but do they occur in volcanic plumes? Stoichiometric considerations had been made in the past suggesting the existence of P-S species in plumes (Stanton 1994), gas sampling and remote gas monitoring systems have not detected yet such molecules in plumes. The particle spectrum of the reawakened Popocateptel volcano might be related to accumulation of volatiles at the top of a magma chamber during the phase of dormancy. P-Fe rich, Ca-free aggregates are also known from the eruption of El Chichon 1982 (SEM/EDS by M. Sheridan, per. comm. 08-24-2003). Persistently active volcanoes (i.e. Stromboli) represent a different category according to continuous degassing and aerosol particle formation. A particle collector ( ca. 90 ml/min) accompanied a COSPEC helicopter flight at Stromboli (May 15, 2003) after one of the rare types of sub-plinian events on April 5 2003. P-bearing particles are very common. For instance, an Fe oxide grain (diam. = 2 æm) is partially covered by fluffy and euhedral P-bearing matter. The elements detected are P, Cl, Na, Mg, Al, Si, K, Ca, Ti and (Fe). The fluffy and the euhedral (rhombohedral?) matter show in SE-BSE-mix image almost identical grey colors. At Stromboli and Popocatepetl particles on which
17. Investigate the relationship between multiwavelength lidar ratios and aerosol size distributions using aerodynamic particle sizer spectrometer
Zhao, Hu; Hua, Dengxin; Mao, Jiandong; Zhou, Chunyan
2017-02-01
The real aerosol size distributions were obtained by aerodynamic particle sizer spectrometer (APS) in China YinChuan. The lidar ratios at wavelengths of 355 nm, 532 nm and 1064 nm were calculated using Mie theory. The effective radius of aerosol particles reff and volume C/F ratio (coarse/fine) Vc/f were retrieved from the real aerosol size distributions. The relationship between multiwavelength lidar ratios and particle reff and Vc/f were investigated. The results indicate that the lidar ratio is positive correlated to the particle reff and Vc/f. The lidar ratio is more sensitive to the coarse particles. The short wavelength lidar ratio is more sensitive to the particle Vc/f and the long wavelength lidar ratio is more sensitive to the particle reff. The wavelength dependency indicated that the lidar ratios decrease with increasing the wavelength. The lidar ratios are almost irrelevant to the shape and total particles of aerosol size distributions.
18. Aerosol particle properties in a South American megacity
Ulke, Ana; Torres-Brizuela, Marcela; Raga, Graciela; Baumgardner, Darrel; Cancelada, Marcela
2015-04-01
The subtropical city of Buenos Aires is located on the western shore of Río de la Plata, on the southeastern coast of Argentina. It is the second largest metropolitan area in South America, with a population density of around 14 thousand people per km2. When all 24 counties of the Great Buenos Aires Metropolitan Area are included it is the third-largest conurbation in Latin America, with a population of around fifteen million inhabitants. The generalized worldwide trend to concentrate human activities in urban regions that continue to expand in area, threatens the local and regional environment. Air pollution in the Buenos Aires airshed is due to local sources (mainly the mobile sources, followed by the electric power plants and some industries) and to distant sources (like biomass burning, dust, marine aerosols and occasionally volcanic ash) whose products arrive in the city area due to the regional transport patterns. Previous research suggests that ambient aerosol particle concentrations should be considered an air quality problem. A field campaign was conducted in Buenos Aires in 2011 in order to characterize some aerosol particles properties measured for the first time in the city. Measurements began in mid- April and continued until December. The field observations were done in a collaborative effort between the Universities of Mexico (UNAM) and Buenos Aires (UBA). A suite of instruments was installed on the roof of an UBA laboratory and classroom buildings (34.54° S, 58.44° W) at an altitude of approximately 30 m above sea level. The measurements included the number concentration of condensation nuclei (CN) larger than approximately 50 nm, the mass concentration of particle-bound polycyclic aromatic hydrocarbons (PPAH), the scattering (Bscat) and absorption (Babs) coefficients at 550 nm and the vertical profiles of backscattered light from aerosols at a wavelength of 910 nm using a ceilometer. In addition, a weather station recorded the meteorological
19. Review: engineering particles using the aerosol-through-plasma method
SciTech Connect
Phillips, Jonathan; Luhrs, Claudia C; Richard, Monique
2009-01-01
For decades, plasma processing of materials on the nanoscale has been an underlying enabling technology for many 'planar' technologies, particularly virtually every aspect of modern electronics from integrated-circuit fabrication with nanoscale elements to the newest generation of photovoltaics. However, it is only recent developments that suggest that plasma processing can be used to make 'particulate' structures of value in fields, including catalysis, drug delivery, imaging, higher energy density batteries, and other forms of energy storage. In this paper, the development of the science and technology of one class of plasma production of particulates, namely, aerosol-through-plasma (A-T-P), is reviewed. Various plasma systems, particularly RF and microwave, have been used to create nanoparticles of metals and ceramics, as well as supported metal catalysts. Gradually, the complexity of the nanoparticles, and concomitantly their potential value, has increased. First, unique two-layer particles were generated. These were postprocessed to create unique three-layer nanoscale particles. Also, the technique has been successfully employed to make other high-value materials, including carbon nanotubes, unsupported graphene, and spherical boron nitride. Some interesting plasma science has also emerged from efforts to characterize and map aerosol-containing plasmas. For example, it is clear that even a very low concentration of particles dramatically changes plasma characteristics. Some have also argued that the local-thermodynamic-equilibrium approach is inappropriate to these systems. Instead, it has been suggested that charged- and neutral-species models must be independently developed and allowed to 'interact' only in generation terms.
20. New aerosol particles formation in the Sao Paulo Metropolitan Area
Vela, Angel; Andrade, Maria de Fatima; Ynoue, Rita
2016-04-01
The Sao Paulo Metropolitan Area (SPMA), in the southeast region of Brazil, is considered a megalopolis comprised of Sao Paulo city and more 38 municipalities. The air pollutant emissions in the SPMA are related to the burning of the fuels: etanol, gasohol (gasoline with 25% ethanol) and diesel. According to CETESB (2013), the road vehicles contributed up to about 97, 87, and 80% of CO, VOCs and NOx emissions in 2012, respectively, being most of NOx associated to diesel combustion and most of CO and VOCs from gasohol and ethanol combustion. Studies conducted on ambient air pollution in the SPMA have shown that black carbon (BC) explains 21% of mass concentration of PM2.5 compared with 40% of organic carbon (OC), 20% of sulfates, and 12% of soil dust (Andrade et al., 2012). Most of the observed ambient PM2.5 mass concentration usually originates from precursors gases such as sulphur dioxide (SO2), ammonia (NH3), nitrogen oxides (NOx) and VOCs as well as through the physico-chemical processes such as the oxidation of low volatile hydrocarbons transferring to the condensed phase (McMurry et al., 2004). The Weather Research and Forecasting with Chemistry model (WRF-Chem; Grell et al. 2005), configured with three nested grid cells: 75, 15, and 3 km, is used as photochemical modeling to describe the physico-chemical processes leading to evolution of particles number and mass size distribution from a vehicular emission model developed by the IAG-USP laboratory of Atmospheric Processes and based on statistical information of vehicular activity. The spatial and temporal distributions of emissions in the finest grid cell are based on road density products compiled by the OpenStreetMap project and measurements performed inside tunnels in the SPMA, respectively. WRF-Chem simulation with coupled primary aerosol (dust and sea-salt) and biogenic emission modules and aerosol radiative effects turned on is conducted as the baseline simulation (Case_0) to evaluate the model
1. Single-particle Analyses of Compositions, Morphology, and Viscosity of Aerosol Particles Collected During GoAmazon2014
Adachi, K.; Gong, Z.; Bateman, A. P.; Martin, S. T.; Cirino, G. G.; Artaxo, P.; Sedlacek, A. J., III; Buseck, P. R.
2014-12-01
Single-particle analysis using transmission electron microscopy (TEM) shows composition and morphology of individual aerosol particles collected during the GoAmazon2014 campaign. These TEM results indicate aerosol types and mixing states, both of which are important for evaluating particle optical properties and cloud condensation nuclei activity. The samples were collected at the T3 site, which is located in the Amazon forest with influences from the urban pollution plume from Manaus. Samples were also collected from the T0 site, which is in the middle of the jungle with minimal to no influences of anthropogenic sources. The aerosol particles mainly originated from 1) anthropogenic pollution (e.g., nanosphere soot, sulfate), 2) biogenic emissions (e.g., primary biogenic particles, organic aerosols), and 3) long-range transport (e.g., sea salts). We found that the biogenic organic aerosol particles contain homogeneously distributed potassium. Particle viscosity is important for evaluating gas-particle interactions and atmospheric chemistry for the particles. Viscosity can be estimated from the rebounding behavior at controlled relative humidities, i.e., highly viscous particles display less rebound on a plate than low-viscosity particles. We collected 1) aerosol particles from a plate (non-rebounded), 2) those that had rebounded from the plate and were then captured onto an adjacent sampling plate, and 3) particles from ambient air using a separate impactor sampler. Preliminary results show that more than 90% of non-rebounded particles consisted of nanosphere soot with or without coatings. The coatings mostly consisted of organic matter. Although rebounded particles also contain nanosphere soot (number fraction 64-69%), they were mostly internally mixed with sulfate, organic matter, or their mixtures. TEM tilted images suggested that the rebounded particles were less deformed on the substrate, whereas the non-rebounded particles were more deformed, which could
2. Laboratory and Ambient Studies Using an Automated Semi-Continuous Single-Particle Aerosol Raman Spectrometer
Doughty, D., III; Hill, S. C.
2015-12-01
Single-particle Raman spectra can yield extensive information about in-situ ambient particulate composition. However, Raman spectral measurements of individual aerosol particles typically require collection of samples in the field followed by offline Raman spectral measurements in a laboratory. The process requires considerable operator time. We report results obtained with an automated, single-particle Aerosol Raman Spectrometer built by Battelle, which is the core of Battelle's Resource Effective Bioidentification System (REBS). This instrument collects aerosol particles onto a metallized polymer tape and simultaneously measures Raman spectra of particles obtained during the previous collection period. At the end of each collection period (typically 15 minutes), the tape is advanced and the next collection and measurement period is begun. In this way, particles are semi-continuously sampled and their Raman spectra are measured. We show laboratory data from different sizes of polystyrene latex spheres. We also show results from calcium sulfate particles, vehicular emission soot, and other particles. We discuss the influence of imaging time on the quality of the Raman spectra measured and on the ability of the instrument to resolve aerosol particles. Finally, we present results from an outdoor sampling period during the summer of 2015 where the instrument ran unattended for more than one week collecting particles and measuring their Raman spectra. We suggest that the routine use of such an automated particle-sampling instrument should increase our understanding of inorganic and organic aerosols including biological aerosols and sources and fates of these particles.
3. Composition and hygroscopicity of aerosol particles at Mt. Lu in South China: Implications for acid precipitation
Li, Weijun; Chi, Jianwei; Shi, Zongbo; Wang, Xinfeng; Chen, Bin; Wang, Yan; Li, Tao; Chen, Jianmin; Zhang, Daizhou; Wang, Zifa; Shi, Chune; Liu, Liangke; Wang, Wenxing
2014-09-01
Physicochemical properties of aerosol particles were studied at Mt. Lu, an elevated site (115°59‧E, 29°35‧N, 1165 m) within the acid precipitation area. Northeast winds transport copious amounts of air pollutants and water vapor from the Yangtze River Delta into this acid precipitation area. NH4+ and SO42- are the dominant ions in PM2.5 and determine aerosol acidity. Individual particle analysis shows abundant S-rich and metals (i.e. Fe-, Zn-, Mn-, and Pb-rich) particles. Unlike aerosol particles in North China and urban areas, there are little soot and mineral particles at Mt. Lu. Lack of mineral particles contributed to the higher acidity in precipitation in the research area. Nano-sized spherical metal particles were observed to be embedded in 37% of S-rich particles. These metal particles were likely originated from heavy industries and fired-power plants. Hygroscopic experiments show that most particles start to deliquesce at 73-76% but organic coating lowers the particle deliquescence relative humidity (DRH) to 63-73%. The DRHs of these aerosol particles are clearly smaller than that of pure ammonium sulfate particles which is 80%. Since RH in ambient air was relatively high, ranging from 65% to 85% during our study period, most particles at our sampling site were in liquid phase. Our results suggest that liquid phase reactions in aerosol particles may contribute to SO2 to sulfuric acid conversion in the acid precipitation area.
4. A combined particle trap/HTDMA hygroscopicity study of mixed inorganic/organic aerosol particles
Zardini, A. A.; Sjogren, S.; Marcolli, C.; Krieger, U. K.; Gysel, M.; Weingartner, E.; Baltensperger, U.; Peter, T.
2008-03-01
Atmospheric aerosols are often mixtures of inorganic and organic material. Organics can represent a large fraction of the total aerosol mass and are comprised of water-soluble and insoluble compounds. Increasing attention was paid in the last decade to the capability of mixed inorganic/organic aerosol particles to take up water (hygroscopicity). We performed hygroscopicity measurements of internally mixed particles containing ammonium sulfate and carboxylic acids (citric, glutaric, adipic acid) in parallel with an electrodynamic balance (EDB) and a hygroscopicity tandem differential mobility analyzer (HTDMA). The organic compounds were chosen to represent three distinct physical states. During hygroscopicity cycles covering hydration and dehydration measured by the EDB and the HTDMA, pure citric acid remained always liquid, adipic acid remained always solid, while glutaric acid could be either. We show that the hygroscopicity of mixtures of the above compounds is well described by the Zdanovskii-Stokes-Robinson (ZSR) relationship as long as the two-component particle is completely liquid in the ammonium sulfate/citric acid and in the ammonium sulfate/glutaric acid cases. However, we observe significant discrepancies compared to what is expected from bulk thermodynamics when a solid component is present. We explain this in terms of a complex morphology resulting from the crystallization process leading to veins, pores, and grain boundaries which allow for water sorption in excess of bulk thermodynamic predictions caused by the inverse Kelvin effect on concave surfaces.
5. Size distribution and scattering phase function of aerosol particles retrieved from sky brightness measurements
Kaufman, Y. J.; Gitelson, A.; Karnieli, A.; Ganor, E.; Fraser, R. S.; Nakajima, T.; Mattoo, S.; Holben, B. N.
1994-05-01
Ground-based measurements of the solar transmission and sky radiance in a horizontal plane through the Sun are taken in several geographical regions and aerosol types: dust in a desert transition zone in Israel, sulfate particles in Eastern and Western Europe, tropical aerosol in Brazil, and mixed continental/maritime aerosol in California. Stratospheric aerosol was introduced after the eruption of Mount Pinatubo in June 1991. Therefore measurements taken before the eruption are used to analyze the properties of tropospheric aerosol; measurements from 1992 are also used to detect the particle size and concentration of stratospheric aerosol. The measurements are used to retrieve the size distribution and the scattering phase function at large scattering angles of the undisturbed aerosol particles. The retrieved properties represent an average on the entire atmospheric column. A comparison between the retrieved phase function for a scattering angle of 120°, with phase function predicted from the retrieved size distribution, is used to test the assumption of particle homogeneity and sphericity in radiative transfer models (Mie theory). The effect was found to be small (20%±15%). For the stratospheric aerosol (sulfates), as expected, the phase function was very well predicted using the Mie theory. A model with a power law size distribution, based on the spectral dependence of the optical thickness, a, cannot estimate accurately the phase function (up to 50% error for λ = 0.87 μm). Before the Pinatubo eruption the ratio between the volumes of sulfate and coarse particles was very well correlated with α. The Pinatubo stratospheric aerosol destroyed this correlation. The aerosol optical properties are compared with analysis of the size, shape, and composition of the individual particles by electron microscopy of in situ samples. The measured volume size distributions before the injection of stratospheric aerosol consistently show two modes, sulfate particles with rm
6. Formation of highly porous aerosol particles by atmospheric freeze-drying in ice clouds.
PubMed
Adler, Gabriela; Koop, Thomas; Haspel, Carynelisa; Taraniuk, Ilya; Moise, Tamar; Koren, Ilan; Heiblum, Reuven H; Rudich, Yinon
2013-12-17
The cycling of atmospheric aerosols through clouds can change their chemical and physical properties and thus modify how aerosols affect cloud microphysics and, subsequently, precipitation and climate. Current knowledge about aerosol processing by clouds is rather limited to chemical reactions within water droplets in warm low-altitude clouds. However, in cold high-altitude cirrus clouds and anvils of high convective clouds in the tropics and midlatitudes, humidified aerosols freeze to form ice, which upon exposure to subsaturation conditions with respect to ice can sublimate, leaving behind residual modified aerosols. This freeze-drying process can occur in various types of clouds. Here we simulate an atmospheric freeze-drying cycle of aerosols in laboratory experiments using proxies for atmospheric aerosols. We find that aerosols that contain organic material that undergo such a process can form highly porous aerosol particles with a larger diameter and a lower density than the initial homogeneous aerosol. We attribute this morphology change to phase separation upon freezing followed by a glass transition of the organic material that can preserve a porous structure after ice sublimation. A porous structure may explain the previously observed enhancement in ice nucleation efficiency of glassy organic particles. We find that highly porous aerosol particles scatter solar light less efficiently than nonporous aerosol particles. Using a combination of satellite and radiosonde data, we show that highly porous aerosol formation can readily occur in highly convective clouds, which are widespread in the tropics and midlatitudes. These observations may have implications for subsequent cloud formation cycles and aerosol albedo near cloud edges.
7. Formation of highly porous aerosol particles by atmospheric freeze-drying in ice clouds
PubMed Central
Adler, Gabriela; Koop, Thomas; Haspel, Carynelisa; Taraniuk, Ilya; Moise, Tamar; Koren, Ilan; Heiblum, Reuven H.; Rudich, Yinon
2013-01-01
The cycling of atmospheric aerosols through clouds can change their chemical and physical properties and thus modify how aerosols affect cloud microphysics and, subsequently, precipitation and climate. Current knowledge about aerosol processing by clouds is rather limited to chemical reactions within water droplets in warm low-altitude clouds. However, in cold high-altitude cirrus clouds and anvils of high convective clouds in the tropics and midlatitudes, humidified aerosols freeze to form ice, which upon exposure to subsaturation conditions with respect to ice can sublimate, leaving behind residual modified aerosols. This freeze-drying process can occur in various types of clouds. Here we simulate an atmospheric freeze-drying cycle of aerosols in laboratory experiments using proxies for atmospheric aerosols. We find that aerosols that contain organic material that undergo such a process can form highly porous aerosol particles with a larger diameter and a lower density than the initial homogeneous aerosol. We attribute this morphology change to phase separation upon freezing followed by a glass transition of the organic material that can preserve a porous structure after ice sublimation. A porous structure may explain the previously observed enhancement in ice nucleation efficiency of glassy organic particles. We find that highly porous aerosol particles scatter solar light less efficiently than nonporous aerosol particles. Using a combination of satellite and radiosonde data, we show that highly porous aerosol formation can readily occur in highly convective clouds, which are widespread in the tropics and midlatitudes. These observations may have implications for subsequent cloud formation cycles and aerosol albedo near cloud edges. PMID:24297908
8. Particle size distribution of ambient aerosols in an industrial area.
PubMed
Rao, B Padma; Srivastava, A; Yasmin, F; Ray, S; Gupta, N; Chauhan, C; Rao, C V C; Wate, S R
2012-05-01
Aerosol samples of PM(10) and PM(2.5) were collected from 38 sampling locations in and around the industrial area. The 24 h average mass concentration of PM(10) and PM(2.5) was 137.5 and 61.5 μg/m(3) respectively during summer, 122 and 97.5 μg/m(3) respectively in winter and 70 and 54 μg/m(3) respectively during post monsoon season. The relative contribution of coarse, fine and ultrafine particle to ambient air was analyzed for its temporal and seasonal variability in an industrialized area. This paper aims to establish baseline between PM(10) and PM(2.5) mass concentration levels.
9. Size distribution and scattering phase function of aerosol particles retrieved from sky brightness measurements
NASA Technical Reports Server (NTRS)
Kaufman, Y. J.; Gitelson, A.; Karnieli, A.; Ganor, E. (Editor); Fraser, R. S.; Nakajima, T.; Mattoo, S.; Holben, B. N.
1994-01-01
Ground-based measurements of the solar transmission and sky radiance in a horizontal plane through the Sun are taken in several geographical regions and aerosol types: dust in a desert transition zone in Israel, sulfate particles in Eastern and Western Europe, tropical aerosol in Brazil, and mixed continental/maritime aerosol in California. Stratospheric aerosol was introduced after the eruption of Mount Pinatubo in June 1991. Therefore measurements taken before the eruption are used to analyze the properties of tropospheric aerosol; measurements from 1992 are also used to detect the particle size and concentration of stratospheric aerosol. The measurements are used to retrieve the size distribution and the scattering phase function at large scattering angles of the undisturbed aerosol particles. The retrieved properties represent an average on the entire atmospheric column. A comparison between the retrieved phase function for a scattering angle of 120 deg, with phase function predicted from the retrieved size distribution, is used to test the assumption of particle homogeneity and sphericity in radiative transfer models (Mie theory). The effect was found to be small (20% +/- 15%). For the stratospheric aerosol (sulfates), as expected, the phase function was very well predicted using the Mie theory. A model with a power law distribution, based on the spectral dependence of the optical thickness, alpha, cannot estimate accurately the phase function (up to 50% error for lambda = 0.87 microns). Before the Pinatubo eruption the ratio between the volumes of sulfate and coarse particles was very well correlated with alpha. The Pinatubo stratospheric aerosol destroyed this correlation. The aerosol optical properties are compared with analysis of the size, shape, and composition of the individual particles by electron microscopy of in situ samples. The measured volume size distribution before the injection of stratospheric aerosol consistently show two modes, sulfate
10. Evidence of formation of submicrometer water-soluble organic aerosols at a deciduous forest site in northern Japan in summer
Miyazaki, Yuzo; Jung, Jinsang; Fu, Pingqing; Mizoguchi, Yasuko; Yamanoi, Katsumi; Kawamura, Kimitaka
2012-10-01
Semicontinuous measurements of submicrometer water-soluble organic aerosols and particle size distributions were conducted at a deciduous forest site in northern Japan in August 2010. Increases in particle number concentration were frequently observed in daytime, accompanied by an increase in the concentrations of water-soluble organic carbon (WSOC). We found that daily averaged WSOC concentrations positively correlated with gross primary production of CO2 by the forest ecosystem (r2 = 0.63) and ambient temperature during daytime. These relations suggest that the formation of WSOC is closely linked to photosynthetic activity by the forest ecosystem, which depends on both temperature and solar radiation. Off-line chemical analysis of samples of particles with aerodynamic diameter smaller than 1 μm collected during a 2 day event of elevated WSOC levels suggests that photochemical aging of both α- andβ-pinene and isoprene oxidation products contributes to the particle growth and the WSOC mass. Organic tracers of primary biological aerosol particles (PBAPs) showed distinct diurnal variations with a maximum around noontime, also indicating that higher temperature and light intensity induce emissions of PBAPs. However, their contribution to the submicrometer WSOC mass was likely insignificant. During the day, the concentrations of 3-methyl-1,2,3-butanetricarboxylic acid (3-MBTCA) showed a strong dependence on temperature, and the ratios of WSOC to particle volume concentration increased with an increase in the concentration ratios of 3-MBTCA to pinonic acid (PA). This result supports a previous proposal that the 3-MBTCA/PA ratios in submicrometer particles can be a useful tracer for chemical aging of biogenic secondary organic aerosol from forest vegetation.
11. Real-time detection method and system for identifying individual aerosol particles
DOEpatents
Gard, Eric E.; Coffee, Keith R.; Frank, Matthias; Tobias, Herbert J.; Fergenson, David P.; Madden, Norm; Riot, Vincent J.; Steele, Paul T.; Woods, Bruce W.
2007-08-21
An improved method and system of identifying individual aerosol particles in real time. Sample aerosol particles are collimated, tracked, and screened to determine which ones qualify for mass spectrometric analysis based on predetermined qualification or selection criteria. Screening techniques include one or more of determining particle size, shape, symmetry, and fluorescence. Only qualifying particles passing all screening criteria are subject to desorption/ionization and single particle mass spectrometry to produce corresponding test spectra, which is used to determine the identities of each of the qualifying aerosol particles by comparing the test spectra against predetermined spectra for known particle types. In this manner, activation cycling of a particle ablation laser of a single particle mass spectrometer is reduced.
12. Effects of Hydrodynamic Interaction in Aerosol Particle Settling: Mesoscopic Particle-level Full Dynamics Simulations
Li, Shuiqing; Yang, Mengmeng; Marshall, Jeffrey
2014-11-01
A new mesoscopic particle-level approach is developed for the full dynamics simulation (FDS) of the settling of systems of aerosol micro-particles. The approach efficiently combines an adhesive discrete-element method for particle motions and an Oseen dynamics method for hydrodynamic interactions. Compared to conventional Stokeslet and Oseenlet simulations, the FDS not only accounts for the cloud-scale fluid inertia effect and the particle inertia effect, but also overcomes the singularity problem using a soft-sphere model of adhesive contact. The effect of hydrodynamic interactions is investigated based on FDS results. The particle inertia is found to reduce the mobility of particle clouds and to elongate the cloud on vertical direction. Meanwhile, the fluid inertia decreases the settling velocity by weakening the hydrodynamic interaction and tends to flatten the cloud, leading to breakup. Expressions for the settling velocity of particle cloud are proposed with consideration of fluid inertia effect and the cloud shape. Finally, the transformation in settling behavior from a finite particle cloud to an unbounded uniform suspension is explained. This work has been funded by the National Natural Science Funds of China (No. 50976058), and by the National Key Basic Research and Development Program (2013CB228506).
13. A recirculation aerosol wind tunnel for evaluating aerosol samplers and measuring particle penetration through protective clothing materials.
PubMed
Jaques, Peter A; Hsiao, Ta-Chih; Gao, Pengfei
2011-08-01
A recirculation aerosol wind tunnel was designed to maintain a uniform airflow and stable aerosol size distribution for evaluating aerosol sampler performance and determining particle penetration through protective clothing materials. The oval-shaped wind tunnel was designed to be small enough to fit onto a lab bench, have optimized dimensions for uniformity in wind speed and particle size distributions, sufficient mixing for even distribution of particles, and minimum particle losses. Performance evaluation demonstrates a relatively high level of spatial uniformity, with a coefficient of variation of 1.5-6.2% for wind velocities between 0.4 and 2.8 m s(-1) and, in this range, 0.8-8.5% for particles between 50 and 450 nm. Aerosol concentration stabilized within the first 5-20 min with, approximately, a count median diameter of 135 nm and geometric standard deviation of 2.20. Negligible agglomerate growth and particle loss are suggested. The recirculation design appears to result in unique features as needed for our research.
14. METHODS OF CALCULATINAG LUNG DELIVERY AND DEPOSITION OF AEROSOL PARTICLES
EPA Science Inventory
Lung deposition of aerosol is measured by a variety of methods. Total lung deposition can be measured by monitoring inhaled and exhaled aerosols in situ by laser photometry or by collecting the aerosols on filters. The measurements can be performed accurately for stable monod...
15. Resuspension of Aerosol Particles from Evaporated Rain Drops to the Coarse Mode
Wang, H.; Easter, R. C.; Ganguly, D.; Singh, B.; Rasch, P. J.
2015-12-01
Precipitation scavenging (i.e., wet removal) has long been recognized as one of the major removal processes for tropospheric aerosol particles, and the dominant one for accumulation-mode size particles. When rain drops evaporate, the aerosol material contained in drops is resuspended, and this process has received much less attention. Unlike the resuspension from evaporated cloud droplets, the aerosol particles resuspended from evaporated rain drops have much larger sizes than most of the aerosol particles that acted as cloud condensation nuclei (CCN), became cloud borne, and then were collected by rain drops, because each rain drop generally collects thousands of cloud droplets. Here we present some aspects of this resuspension process obtained from modeling studies. First, we investigate some details of the process using a simple drop-size resolved model of raindrop evaporation in sub-saturated air below cloud base. Using these results, we then investigate different treatments of this process in a global aerosol and climate model that employs a modal aerosol representation. Compared to the model's original treatment of this process in which rain-borne aerosol is resuspended to the mode that it came from with its original size, the new treatment that resuspends to the coarse mode produces notable reductions in global CCN concentrations, as well as sulfate, black carbon, and organic aerosol mass, because the resuspended aerosol particles have much shorter lifetimes due to their larger sizes. Somewhat surprisingly, there are also notable reductions in coarse-mode sea salt and mineral dust burdens. These species are resuspended to the coarse mode in both the original and new treatments, but these resuspended particles are fewer in number and larger in size in the new treatment. This finding highlights some issues of the modal aerosol treatment for coarse mode particles.
16. Improved Tandem Measurement Techniques for Aerosol Particle Analysis
Rawat, Vivek Kumar
Non-spherical, chemically inhomogeneous (complex) nanoparticles are encountered in a number of natural and engineered environments, including combustion systems (which produces highly non-spherical aggregates), reactors used in gas-phase materials synthesis of doped or multicomponent materials, and in ambient air. These nanoparticles are often highly diverse in size, composition and shape, and hence require determination of property distribution functions for accurate characterization. This thesis focuses on development of tandem mobility-mass measurement techniques coupled with appropriate data inversion routines to facilitate measurement of two dimensional size-mass distribution functions while correcting for the non-idealities of the instruments. Chapter 1 provides the detailed background and motivation for the studies performed in this thesis. In chapter 2, the development of an inversion routine is described which is employed to determine two dimensional size-mass distribution functions from Differential Mobility Analyzer-Aerosol Particle Mass analyzer tandem measurements. Chapter 3 demonstrates the application of the two dimensional distribution function to compute cumulative mass distribution function and also evaluates the validity of this technique by comparing the calculated total mass concentrations to measured values for a variety of aerosols. In Chapter 4, this tandem measurement technique with the inversion routine is employed to analyze colloidal suspensions. Chapter 5 focuses on application of a transverse modulation ion mobility spectrometer coupled with a mass spectrometer to study the effect of vapor dopants on the mobility shifts of sub 2 nm peptide ion clusters. These mobility shifts are then compared to models based on vapor uptake theories. Finally, in Chapter 6, a conclusion of all the studies performed in this thesis is provided and future avenues of research are discussed.
17. Molecular Characterization of Brown Carbon in Biomass Burning Aerosol Particles
SciTech Connect
Lin, Peng; Aiona, Paige K.; Li, Ying; Shiraiwa, Manabu; Laskin, Julia; Nizkorodov, Sergey A.; Laskin, Alexander
2016-11-01
Emissions from biomass burning are a significant source of brown carbon (BrC) in the atmosphere. In this study, we investigate the molecular composition of freshly-emitted biomass burning organic aerosol (BBOA) samples collected during test burns of selected biomass fuels: sawgrass, peat, ponderosa pine, and black spruce. We characterize individual BrC chromophores present in these samples using high performance liquid chromatography coupled to a photodiode array detector and a high-resolution mass spectrometer. We demonstrate that both the overall BrC absorption and the chemical composition of light-absorbing compounds depend significantly on the type of biomass fuels and burning conditions. Common BrC chromophores in the selected BBOA samples include nitro-aromatics, polycyclic aromatic hydrocarbon derivatives, and polyphenols spanning a wide range of molecular weights, structures, and light absorption properties. A number of biofuel-specific BrC chromophores are observed, indicating that some of them may be used as potential markers of BrC originating from different biomass burning sources. On average, ~50% of the light absorption above 300 nm can be attributed to a limited number of strong BrC chromophores, which may serve as representative light-absorbing species for studying atmospheric processing of BrC aerosol. The absorption coefficients of BBOA are affected by solar photolysis. Specifically, under typical atmospheric conditions, the 300 nm absorbance decays with a half-life of 16 hours. A “molecular corridors” analysis of the BBOA volatility distribution suggests that many BrC compounds in the fresh BBOA have low volatility (<1 g m-1) and will be retained in the particle phase under atmospherically relevant conditions.
18. Electron mean free path from angle-dependent photoelectron spectroscopy of aerosol particles
SciTech Connect
Goldmann, Maximilian; Miguel-Sánchez, Javier; West, Adam H. C.; Yoder, Bruce L.; Signorell, Ruth
2015-06-14
We propose angle-resolved photoelectron spectroscopy of aerosol particles as an alternative way to determine the electron mean free path of low energy electrons in solid and liquid materials. The mean free path is obtained from fits of simulated photoemission images to experimental ones over a broad range of different aerosol particle sizes. The principal advantage of the aerosol approach is twofold. First, aerosol photoemission studies can be performed for many different materials, including liquids. Second, the size-dependent anisotropy of the photoelectrons can be exploited in addition to size-dependent changes in their kinetic energy. These finite size effects depend in different ways on the mean free path and thus provide more information on the mean free path than corresponding liquid jet, thin film, or bulk data. The present contribution is a proof of principle employing a simple model for the photoemission of electrons and preliminary experimental data for potassium chloride aerosol particles.
19. Apparatus having reduced background for measuring radiation activity in aerosol particles
DOEpatents
Rodgers, John C.; McFarland, Andrew R.; Oritz, Carlos A.; Marlow, William H.
1992-01-01
Apparatus having reduced background for measuring radiation activity in aerosol particles. A continuous air monitoring sampler is described for use in detecting the presence of alpha-emitting aerosol particles. An inlet fractionating screen has been demonstrated to remove about 95% of freshly formed radon progeny from the aerosol sample, and approximately 33% of partially aged progeny. Addition of an electrical condenser and a modified dichotomous virtual impactor are expected to produce considerable improvement in these numbers, the goal being to enrich the transuranic (TRU) fraction of the aerosols. This offers the possibility of improving the signal-to-noise ratio for the detected alpha-particle energy spectrum in the region of interest for detecting TRU materials associated with aerosols, thereby enhancing the performance of background-compensation algorithms for improving the quality of alarm signals intended to warn personnel of potentially harmful quantities of TRU materials in the ambient air.
20. A combined particle trap/HTDMA hygroscopicity study of mixed inorganic/organic aerosol particles
Zardini, A. A.; Sjogren, S.; Marcolli, C.; Krieger, U. K.; Gysel, M.; Weingartner, E.; Baltensperger, U.; Peter, T.
2008-09-01
Atmospheric aerosols are often mixtures of inorganic and organic material. Organics can represent a large fraction of the total aerosol mass and are comprised of water-soluble and insoluble compounds. Increasing attention was paid in the last decade to the capability of mixed inorganic/organic aerosol particles to take up water (hygroscopicity). We performed hygroscopicity measurements of internally mixed particles containing ammonium sulfate and carboxylic acids (citric, glutaric, adipic acid) in parallel with an electrodynamic balance (EDB) and a hygroscopicity tandem differential mobility analyzer (HTDMA). The organic compounds were chosen to represent three distinct physical states. During hygroscopicity cycles covering hydration and dehydration measured by the EDB and the HTDMA, pure citric acid remained always liquid, adipic acid remained always solid, while glutaric acid could be either. We show that the hygroscopicity of mixtures of the above compounds is well described by the Zdanovskii-Stokes-Robinson (ZSR) relationship as long as the two-component particle is completely liquid in the ammonium sulfate/glutaric acid system; deviations up to 10% in mass growth factor (corresponding to deviations up to 3.5% in size growth factor) are observed for the ammonium sulfate/citric acid 1:1 mixture at 80% RH. We observe even more significant discrepancies compared to what is expected from bulk thermodynamics when a solid component is present. We explain this in terms of a complex morphology resulting from the crystallization process leading to veins, pores, and grain boundaries which allow for water sorption in excess of bulk thermodynamic predictions caused by the inverse Kelvin effect on concave surfaces.
1. Identification of characteristic mass spectrometric markers for primary biological aerosol particles and comparison with field data from submicron pristine aerosol particles
Freutel, F.; Schneider, J.; Zorn, S. R.; Drewnick, F.; Borrmann, S.; Hoffmann, T.; Martin, S. T.
2009-04-01
The contribution of primary biological aerosol (PBA) to the total aerosol particle concentration is estimated to range between 25 and 80%, depending on location and season. Especially in the tropical rain forest it is expected that PBA is a major source of particles in the supermicron range, and is also an important fraction of the submicron aerosol. PBA particles like plant fragments, pollen, spores, fungi, viruses etc. contain chemical compounds as proteins, sugars, amino acids, chlorophyll, and cellular material as cellulose. For this reason we have performed mass spectrometric laboratory measurements (Aerodyne C-ToF and W-ToF AMS, single particle laser ablation instrument SPLAT) on pure submicron aerosol particles containing typical PBA compounds in order to identify typical mass spectral patterns of these compounds and to explain the observed fragmentation patterns on the basis of molecular structures. These laboratory data were compared to submicron particle mass spectra obtained during AMAZE-08 (Amazonian Aerosol CharacteriZation Experiment, Brazil, February/March 2008). The results indicate that characteristic m/z ratios for carbohydrates (e.g., glucose, saccharose, levoglucosan, mannitol) can be identified, for example m/z = 60(C2H4O2+) or m/z = 61(C2H5O2+). Certain characteristic peaks for amino acids were also identified in the laboratory experiments. In the field data from AMAZE-08, these characteristic peaks for carbohydrates and amino acids were found, and their contribution to the total organic mass was estimated to about 5%. Fragment ions from peptides and small proteins were also identified in laboratory experiments. Larger proteins, however, seem to become oxidized to CO2+ to a large extend in the vaporizing process of the AMS. Thus, detection of proteins in atmospheric aerosol particles with the AMS appears to be difficult.
2. MATRIX-ASSISTED LASER DESORPTION IONIZATION OF SIZE AND COMPOSITION SELECTED AEROSOL PARTICLES. (R823980)
EPA Science Inventory
Matrix-assisted laser desorption/ionization (MALDI) was performed on individual,
size-selected aerosol particles in the 2-8 mu m diameter range, Monodisperse aerosol droplets
containing matrix, analyte, and solvent were generated and entrained in a dry stream of air, The dr...
3. MATHEMATICAL MODEL FOR GAS/PARTICLE PARTITIONING OF SECONDARY ORGANIC AEROSOLS. (R824970)
EPA Science Inventory
A dynamic model is developed for gas-particle absorptive partitioning of semi-volatile organic aerosols. The model is applied to simulate a pair of m-xylene/NOx outdoor smog chamber experiments. In the presence of an inorganic seed aerosol a threshold ...
4. A Micro Aerosol Sensor for the Measurement of Airborne Ultrafine Particles
PubMed Central
Zhang, Chao; Zhu, Rong; Yang, Wenming
2016-01-01
Particle number concentration and particle size are the two key parameters used to characterize exposure to airborne nanoparticles or ultrafine particles that have attracted the most attention. This paper proposes a simple micro aerosol sensor for detecting the number concentration and particle size of ultrafine particles with diameters from 50 to 253 nm based on electrical diffusion charging. The sensor is composed of a micro channel and a couple of planar electrodes printed on two circuit boards assembled in parallel, which thus integrate charging, precipitating and measurement elements into one chip, the overall size of which is 98 × 38 × 25 mm3. The experiment results demonstrate that the sensor is useful for measuring monodisperse aerosol particles with number concentrations from 300 to 2.5 × 104 /cm3 and particle sizes from 50 to 253 nm. The aerosol sensor has a simple structure and small size, which is favorable for use in handheld devices. PMID:26999156
5. [Factors influencing particle measurement of aerosols and their retention in the lung].
PubMed
Le Bouffant, L
1977-01-01
The dimensional characteristics of the particles of an aerosol depend on the means used for producing them. Mechanical spray and ultrasonic dispersion give polydispersed particles. On the other hand, centrifugal atomization produces a monodispersed aerosol. Particle retention in the lung system depends on the particle diameter. In addition, retention varies according to the respiratory characteristics: it is minimal for about 15 inspirations per minute. Using iron-59 labeled particles, it was shown that the degree of retention varies considerably from one individual to the other and accessibility to the depths of the lungs is decreased under the effect of certain lesions. Bronchial retention appears to be increased in smokers.
6. Hygroscopicity and chemical composition of Antarctic sub-micrometre aerosol particles and observations of new particle formation
Asmi, E.; Frey, A.; Virkkula, A.; Ehn, M.; Manninen, H. E.; Timonen, H.; Tolonen-Kivimäki, O.; Aurela, M.; Hillamo, R.; Kulmala, M.
2009-12-01
The Antarctic near-coastal sub-micrometre aerosol particle features in summer were characterised based on measured data on aerosol hygroscopicity, size distributions, volatility and chemical ion and organic carbon mass concentrations. Hysplit model was used to calculate the history of the air masses to predict the particle origin. Additional measurements of meteorological parameters were utilised. The hygroscopic properties of particles mostly resembled those of marine aerosols. The measurements took place at 130 km from the Southern Ocean, which was the most significant factor affecting the particle properties. This is explained by the lack of additional sources on the continent of Antarctica. The Southern Ocean was thus a likely source of the particles and nucleating and condensing vapours. The particles were very hygroscopic (HGF 1.75 at 90 nm) and very volatile. Most of the sub-100 nm particle volume volatilised below 100 °C. Based on chemical data, particle hygroscopic and volatile properties were explained by a large fraction of non-neutralised sulphuric acid together with organic material. The hygroscopic growth factors assessed from chemical data were similar to measured. Hygroscopicity was higher in dry continental air masses compared with the moist marine air masses. This was explained by the aging of the marine organic species and lower methanesulphonic acid volume fraction together with the changes in the inorganic aerosol chemistry as the aerosol had travelled long time over the continental Antarctica. Special focus was directed in detailed examination of the observed new particle formation events. Indications of the preference of negative over positive ions in nucleation could be detected. However, in a detailed case study, the neutral particles dominated the particle formation process. Freshly nucleated particles had the smallest hygroscopic growth factors, which increased subsequent to particle aging.
7. Hygroscopicity and chemical composition of Antarctic sub-micrometre aerosol particles and observations of new particle formation
Asmi, E.; Frey, A.; Virkkula, A.; Ehn, M.; Manninen, H. E.; Timonen, H.; Tolonen-Kivimäki, O.; Aurela, M.; Hillamo, R.; Kulmala, M.
2010-05-01
The Antarctic near-coastal sub-micrometre aerosol particle features in summer were characterised based on measured data on aerosol hygroscopicity, size distributions, volatility and chemical ion and organic carbon mass concentrations. Hysplit model was used to calculate the history of the air masses to predict the particle origin. Additional measurements of meteorological parameters were utilised. The hygroscopic properties of particles mostly resembled those of marine aerosols. The measurements took place at 130 km from the Southern Ocean, which was the most significant factor affecting the particle properties. This is explained by the lack of additional sources on the continent of Antarctica. The Southern Ocean was thus a likely source of the particles and nucleating and condensing vapours. The particles were very hygroscopic (HGF 1.75 at 90 nm) and very volatile. Most of the sub-100 nm particle volume volatilised below 100 °C. Based on chemical data, particle hygroscopic and volatile properties were explained by a large fraction of non-neutralised sulphuric acid together with organic material. The hygroscopic growth factors assessed from chemical data were similar to measured. Hygroscopicity was higher in dry continental air masses compared with the moist marine air masses. This was explained by the aging of the marine organic species and lower methanesulphonic acid volume fraction together with the changes in the inorganic aerosol chemistry as the aerosol had travelled long time over the continental Antarctica. Special focus was directed in detailed examination of the observed new particle formation events. Indications of the preference of negative over positive ions in nucleation could be detected. However, in a detailed case study, the neutral particles dominated the particle formation process. Freshly nucleated particles had the smallest hygroscopic growth factors, which increased subsequent to particle aging.
8. Estimating Marine Aerosol Particle Volume and Number from Maritime Aerosol Network Data
NASA Technical Reports Server (NTRS)
Sayer, A. M.; Smirnov, A.; Hsu, N. C.; Munchak, L. A.; Holben, B. N.
2012-01-01
As well as spectral aerosol optical depth (AOD), aerosol composition and concentration (number, volume, or mass) are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN) cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET) inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS) data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The average solution MODIS dataset agrees more closely with MAN than the best solution dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data.
9. Ambient measurement of fluorescent aerosol particles with a WIBS in the Yangtze River Delta of China: potential impacts of combustion-related aerosol particles
Yu, Xiawei; Wang, Zhibin; Zhang, Minghui; Kuhn, Uwe; Xie, Zhouqing; Cheng, Yafang; Pöschl, Ulrich; Su, Hang
2016-09-01
Fluorescence characteristics of aerosol particles in a polluted atmosphere were studied using a wideband integrated bioaerosol spectrometer (WIBS-4A) in Nanjing, Yangtze River Delta area of China. We observed strong diurnal and day-to-day variations of fluorescent aerosol particles (FAPs). The average number concentrations of FAPs (1-15 µm) detected in the three WIBS measurement channels (FL1: 0.6 cm-3, FL2: 3.4 cm-3, FL3: 2.1 cm-3) were much higher than those observed in forests and rural areas, suggesting that FAPs other than bioaerosols were detected. We found that the number fractions of FAPs were positively correlated with the black carbon mass fraction, especially for the FL1 channel, indicating a large contribution of combustion-related aerosols. To distinguish bioaerosols from combustion-related FAPs, we investigated two classification schemes for use with WIBS data. Our analysis suggests a strong size dependence for the fractional contributions of different types of FAPs. In the FL3 channel, combustion-related particles seem to dominate the 1-2 µm size range while bioaerosols dominate the 2-5 µm range. The number fractions of combustion-related particles and non-combustion-related particles to total aerosol particles were ˜ 11 and ˜ 5 %, respectively.
10. Calf Lung Surfactant Recovers Surface Functionality After Exposure to Aerosols Containing Polymeric Particles
PubMed Central
Farnoud, Amir M.
2016-01-01
Abstract Background: Recent studies have shown that colloidal particles can disrupt the interfacial properties of lung surfactant and thus key functional abilities of lung surfactant. However, the mechanisms underlying the interactions between aerosols and surfactant films remain poorly understood, as our ability to expose films to particles via the aerosol route has been limited. The aim of this study was to develop a method to reproducibly apply aerosols with a quantifiable particle dose on lung surfactant films and investigate particle-induced changes to the interfacial properties of the surfactant under conditions that more closely mimic those in vivo. Methods: Films of DPPC and Infasurf® were exposed to aerosols containing polystyrene particles generated using a Dry Powder Insufflator™. The dose of particles deposited on surfactant films was determined via light absorbance. The interfacial properties of the surfactant were studied using a Langmuir-Wilhelmy balance during surfactant compression to film collapse and cycles of surface compression and expansion at a fast cycling rate within a small surface area range. Results: Exposure of surfactant films to aerosols led to reproducible dosing of particles on the films. In film collapse experiments, particle deposition led to slight changes in collapse surface pressure and surface area of both surfactants. However, longer interaction times between particles and Infasurf® films resulted in time-dependent inhibition of surfactant function. When limited to lung relevant surface pressures, particles reduced the maximum surface pressure that could be achieved. This inhibitory effect persisted for all compression-expansion cycles in DPPC, but normal surfactant behavior was restored in Infasurf® films after five cycles. Conclusions: The observation that Infasurf® was able to quickly restore its function after exposure to aerosols under conditions that better mimicked those in vivo suggests that particle
11. Influence of particle size and chemistry on the cloud nucleating properties of aerosols
Quinn, P. K.; Bates, T. S.; Coffman, D. J.; Covert, D. S.
2008-02-01
The ability of an aerosol particle to act as a cloud condensation nuclei (CCN) is a function of the size of the particle, its composition and mixing state, and the supersaturation of the cloud. In-situ data from field studies provide a means to assess the relative importance of these parameters. During the 2006 Texas Air Quality - Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS-GoMACCS), the NOAA RV Ronald H. Brown encountered a wide variety of aerosol types ranging from marine near the Florida panhandle to urban and industrial in the Houston-Galveston area. These varied sources provided an opportunity to investigate the role of aerosol sources and chemistry in the potential activation of particles to form cloud droplets. Measurements were made of CCN concentrations, aerosol chemical composition in the size range relevant for particle activation in warm clouds, and aerosol size distributions. Variability in aerosol composition was parameterized by the mass fraction of Hydrocarbon-like Organic Aerosol (HOA) for particle diameters less than 200 nm (vacuum aerodynamic). The HOA mass fraction in this size range was lowest for marine aerosol and highest for aerosol sampled close to anthropogenic sources. Combining all data from the experiment reveals that composition (defined by HOA mass fraction) explains 40% of the variance in the critical diameter for particle activation at the instrumental supersaturation (S) of 0.44%. Correlations between HOA mass fraction and aerosol mean diameter show that these two parameters are essentially independent of one another for this data set. We conclude that, based on the variability of the HOA mass fraction observed during TexAQS-GoMACCS, variability in particle composition played a significant role in determining the fraction of particles that could activate to form cloud droplets. Using a simple model based on Köhler theory and the assumption that HOA is insoluble, we estimate the degree to which calculated CCN
12. Molecular Characterization of Brown Carbon in Biomass Burning Aerosol Particles.
PubMed
Lin, Peng; Aiona, Paige K; Li, Ying; Shiraiwa, Manabu; Laskin, Julia; Nizkorodov, Sergey A; Laskin, Alexander
2016-11-01
Emissions from biomass burning are a significant source of brown carbon (BrC) in the atmosphere. In this study, we investigate the molecular composition of freshly emitted biomass burning organic aerosol (BBOA) samples collected during test burns of sawgrass, peat, ponderosa pine, and black spruce. We demonstrate that both the BrC absorption and the chemical composition of light-absorbing compounds depend significantly on the type of biomass fuels. Common BrC chromophores in the selected BBOA samples include nitro-aromatics, polycyclic aromatic hydrocarbon derivatives, and polyphenols spanning a wide range of molecular weights, structures, and light absorption properties. A number of biofuel-specific BrC chromophores are observed, indicating that some of them may be used as source-specific markers of BrC. On average, ∼50% of the light absorption in the solvent-extractable fraction of BBOA can be attributed to a limited number of strong BrC chromophores. The absorption coefficients of BBOA are affected by solar photolysis. Specifically, under typical atmospheric conditions, the 300 nm absorbance decays with a half-life of ∼16 h. A "molecular corridor" analysis of the BBOA volatility distribution suggests that many BrC compounds in the fresh BBOA have low saturation mass concentration (<1 μg m(-3)) and will be retained in the particle phase under atmospherically relevant conditions.
13. Influence of crustal dust and sea spray supermicron particle concentrations and acidity on inorganic NO3− aerosol during the 2013 Southern Oxidant and Aerosol Study
DOE PAGES
Allen, H. M.; Draper, D. C.; Ayres, B. R.; ...
2015-09-25
Inorganic aerosol composition was measured in the southeastern United States, a region that exhibits high aerosol mass loading during the summer, as part of the 2013 Southern Oxidant and Aerosol Study (SOAS) campaign. Measurements using a Monitor for AeRosols and GAses (MARGA) revealed two periods of high aerosol nitrate (NO3−) concentrations during the campaign. These periods of high nitrate were correlated with increased concentrations of supermicron crustal and sea spray aerosol species, particularly Na+ and Ca2+, and with a shift towards aerosol with larger (1 to 2.5 μm) diameters. We suggest this nitrate aerosol forms by multiphase reactions of HNO3more » and particles, reactions that are facilitated by transport of crustal dust and sea spray aerosol from a source within the United States. The observed high aerosol acidity prevents the formation of NH4NO3, the inorganic nitrogen species often dominant in fine-mode aerosol at higher pH. In addition, calculation of the rate of the heterogeneous uptake of HNO3 on mineral aerosol supports the conclusion that aerosol NO3− is produced primarily by this process, and is likely limited by the availability of mineral cation-containing aerosol surface area. Modeling of NO3− and HNO3 by thermodynamic equilibrium models (ISORROPIA II and E-AIM) reveals the importance of including mineral cations in the southeastern United States to accurately balance ion species and predict gas–aerosol phase partitioning.« less
14. Mixing state of ambient aerosols in Nanjing city by single particle mass spectrometry
Wang, Honglei; An, Junlin; Shen, Lijuan; Zhu, Bin; Xia, Li; Duan, Qing; Zou, Jianan
2016-05-01
To investigate the mixing state and size-resolved aerosol in Nanjing, measurements were carried out for the period 14th January-1st February 2013 by using a Single Particle Aerosol Mass Spectrometer (SPAMS). A total of 10,864,766 particles were sized with vacuum aerodynamic diameter (dva) in the range of 0.2-2.0 μm. Of which, 1,989,725 particles were successfully ionized. Aerosol particles employed for analyzing SPAMS data utilized 96% of the hit particles to identify 5 main particle groups. The particle classes include: K-rich particles (K-CN, K-Nitrate, K-Sulfate and K-Secondary), sodium particles, ammonium particles, carbon-rich particles (OC, EC and OCEC) and heavy-metal particles (Fe-Secondary, Pb-Nitrate, Cu-Mn-Secondary and V-Secondary). EC was the largest contributor with a fraction of 21.78%, followed by K-Secondary (17.87%), K-Nitrate (12.68%) and K-CN (11.25%). High particle level and high RH (relative humidity) are two important factors decreasing visibility in Nanjing. Different particle classes have distinct extinction effects. It anti-correlated well with visibility for the K-secondary, sodium, ammonium, EC, Fe-Secondary and K-Nitrate particles. The proportion of EC particles at 0.65-1.4 μm was up to 25% on haze days and was below 10% on clean days.
15. Aerosol reduction/expansion synthesis (A-RES) for zero valent metal particles
DOEpatents
Leseman, Zayd; Luhrs, Claudia; Phillips, Jonathan; Soliman, Haytham
2016-04-12
Various embodiments provide methods of forming zero valent metal particles using an aerosol-reductive/expansion synthesis (A-RES) process. In one embodiment, an aerosol stream including metal precursor compound(s) and chemical agent(s) that produces reducing gases upon thermal decomposition can be introduced into a heated inert atmosphere of a RES reactor to form zero valent metal particles corresponding to metals used for the metal precursor compound(s).
16. Size matters in the water uptake and hygroscopic growth of atmospherically relevant multicomponent aerosol particles.
PubMed
Laskina, Olga; Morris, Holly S; Grandquist, Joshua R; Qin, Zhen; Stone, Elizabeth A; Tivanski, Alexei V; Grassian, Vicki H
2015-05-14
Understanding the interactions of water with atmospheric aerosols is crucial for determining the size, physical state, reactivity, and climate impacts of this important component of the Earth's atmosphere. Here we show that water uptake and hygroscopic growth of multicomponent, atmospherically relevant particles can be size dependent when comparing 100 nm versus ca. 6 μm sized particles. It was determined that particles composed of ammonium sulfate with succinic acid and of a mixture of chlorides typical of the marine environment show size-dependent hygroscopic behavior. Microscopic analysis of the distribution of components within the aerosol particles show that the size dependence is due to differences in the mixing state, that is, whether particles are homogeneously mixed or phase separated, for different sized particles. This morphology-dependent hygroscopicity has consequences for heterogeneous atmospheric chemistry as well as aerosol interactions with electromagnetic radiation and clouds.
17. Particle size distribution of the stratospheric aerosol from SCIAMACHY limb measurements
Rozanov, Alexei; Malinina, Elizaveta; Rozanov, Vladimir; Hommel, Rene; Burrows, John
2016-04-01
Stratospheric aerosols are of a great scientific interest because of their crucial role in the Earth's radiative budget as well as their contribution to chemical processes resulting in ozone depletion. While the permanent aerosol background in the stratosphere is determined by the tropical injection of SO2, COS and sulphate particles from the troposphere, major perturbations of the stratospheric aerosol layer result form an uplift of SO2 after strong volcanic eruptions. Satellite measurements in the visible spectral range represent one of the most important sources of information about the vertical distribution of the stratospheric aerosol on the global scale. This study employs measurements of the scattered solar light performed in the limb viewing geometry from the space borne spectrometer SCIAMACHY, which operated onboard the ENVISAT satellite, from August 2002 to April 2012. A retrieval approach to obtain parameters of the stratospheric aerosol particle size distribution will be reported along with the sensitivity studies and first results.
18. Mass Spectrometric Analysis of Pristine Aerosol Particles During the wet Season of Amazonia - Detection of Primary Biological Particles?
Schneider, J.; Zorn, S. R.; Freutel, F.; Borrmann, S.; Chen, Q.; Farmer, D. K.; Jimenez, J. L.; Flores, M.; Roldin, P.; Artaxo, P.; Martin, S. T.
2008-12-01
The contribution of primary biological aerosol (POA) particles to the natural organic aerosol is a subject of current research. Estimations of the POA contribution to the total aerosol particle concentration range between 25 and 80%, depending on location and season. Especially in the tropical rain forest it is expected that POA is a major source of supermicron, possibly also of submicron particles. During AMAZE (Amazonian Aerosol CharacteriZation Experiment), a field project near Manaus, Brazil, in February/March 2008, an Aerodyne ToF-AMS was equipped with a high pressure aerodynamic lens. This high pressure lens (operating pressure 14.6 torr) is designed with the objective to extend the detectable size range of the AMS into the supermicron size range where primary biological particles are expected. Size distribution measured by the AMS were compared with size distribution from an optical particle counter and indicate that the high pressure lens has a 50% cut-off at a vacuum aerodynamic diameter of about 1 μm, but still has significant transmission up to a vacuum aerodynamic diameter of about 2 μm, thus extending the detectable size range of the AMS into the coarse mode. The measuring instruments were situated in a container at ground level. The aerosol was sampled through a 40 m vertical, laminar inlet, which was heated and dried to maintain a relative humidity between 30 and 40%. The inlet was equipped with a 7 μm cut-off cyclone. Size distributions recorded with an optical particle counter parallel to the AMS show that the inlet transmitted aerosol particles up to an optically detected diameter of 10 μm. POA particles like plant fragments, pollen, spores, fungi, viruses etc. contain chemical compounds as proteins, sugars, amino acids, chlorophyll, and cellular material as cellulose. Laboratory experiments have been performed in order to identify typical mass spectral patterns of these compounds. These laboratory data were compared to size resolved particle
19. Formation and growth of indoor air aerosol particles as a result of D-limonene oxidation
Vartiainen, E.; Kulmala, M.; Ruuskanen, T. M.; Taipale, R.; Rinne, J.; Vehkamäki, H.
Oxidation of D-limonene, which is a common monoterpene, can lead to new aerosol particle formation in indoor environments. Thus, products containing D-limonene, such as citrus fruits, air refresheners, household cleaning agents, and waxes, can act as indoor air aerosol particle sources. We released D-limonene into the room air by peeling oranges and measured the concentration of aerosol particles of three different size ranges. In addition, we measured the concentration of D-limonene, the oxidant, and the concentration of ozone, the oxidizing gas. Based on the measurements we calculated the growth rate of the small aerosol particles, which were 3-10 nm in diameter, to be about 6300nmh-1, and the losses of the aerosol particles that were due to the coagulation and condensation processes. From these, we further approximated the concentration of the condensable vapour and its source rate and then calculated the formation rate of the small aerosol particles. For the final result, we calculated the nucleation rate and the maximum number of molecules in a critical cluster. The nucleation rate was in the order of 105cm-3s-1 and the number of molecules in a critical-sized cluster became 1.2. The results were in agreement with the activation theory.
20. Aerosolization, Chemical Characterization, Hygroscopicity and Ice Formation of Marine Biogenic Particles
Alpert, P. A.; Radway, J.; Kilthau, W.; Bothe, D.; Knopf, D. A.; Aller, J. Y.
2013-12-01
The oceans cover the majority of the earth's surface, host nearly half the total global primary productivity and are a major source of atmospheric aerosol particles. However, effects of biological activity on sea spray generation and composition, and subsequent cloud formation are not well understood. Our goal is to elucidate these effects which will be particularly important over nutrient rich seas, where microorganisms can reach concentrations of 10^9 per mL and along with transparent exopolymer particles (TEP) can become aerosolized. Here we report the results of mesocosm experiments in which bubbles were generated by two methods, either recirculating impinging water jets or glass frits, in natural or artificial seawater containing bacteria and unialgal cultures of three representative phytoplankton species, Thalassiosira pseudonana, Emiliania huxleyi, and Nannochloris atomus. Over time we followed the size distribution of aerosolized particles as well as their hygroscopicity, heterogeneous ice nucleation potential, and individual physical-chemical characteristics. Numbers of cells and the mass of dissolved and particulate organic carbon (DOC, POC), TEP (which includes polysaccharide-containing microgels and nanogels >0.4 μm in diameter) were determined in the bulk water, the surface microlayer, and aerosolized material. Aerosolized particles were also impacted onto substrates for ice nucleation and water uptake experiments, elemental analysis using computer controlled scanning electron microscopy and energy dispersive analysis of X-rays (CCSEM/EDX), and determination of carbon bonding with scanning transmission X-ray microscopy and near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Regardless of bubble generation method, the overall concentration of aerosol particles, TEP, POC and DOC increased as concentrations of bacterial and phytoplankton cells increased, stabilized, and subsequently declined. Particles <100 nm generated by means of jets
1. The effect of aerosol vertical profiles on satellite-estimated surface particle sulfate concentrations
SciTech Connect
Liu, Yang; Wang, Zifeng; Wang, Jun; Ferrare, Richard A.; Newsom, Rob K.; Welton, Ellsworth J.
2011-02-15
The aerosol vertical distribution is an important factor in determining the relationship between satellite retrieved aerosol optical depth (AOD) and ground-level fine particle pollution concentrations. We evaluate how aerosol profiles measured by ground-based lidar and simulated by models can help improve the association between AOD retrieved by the Multi-angle Imaging Spectroradiometer (MISR) and fine particle sulfate (SO4) concentrations using matched data at two lidar sites. At the Goddard Space Flight Center (GSFC) site, both lidar and model aerosol profiles marginally improve the association between SO4 concentrations and MISR fractional AODs, as the correlation coefficient between cross-validation (CV) and observed SO4 concentrations changes from 0.87 for the no-scaling model to 0.88 for models scaled with aerosol vertical profiles. At the GSFC site, a large amount of urban aerosols resides in the well-mixed boundary layer so the column fractional AODs are already excellent indicators of ground-level particle pollution. In contrast, at the Atmospheric Radiation Measurement Program (ARM) site with relatively low aerosol loadings, scaling substantially improves model performance. The correlation coefficient between CV and observed SO4 concentrations is increased from 0.58 for the no-scaling model to 0.76 in the GEOS-Chem scaling model, and the model bias is reduced from 17% to 9%. In summary, despite the inaccuracy due to the coarse horizontal resolution and the challenges of simulating turbulent mixing in the boundary layer, GEOS-Chem simulated aerosol profiles can still improve methods for estimating surface aerosol (SO4) mass from satellite-based AODs, particularly in rural areas where aerosols in the free troposphere and any long-range transport of aerosols can significantly contribute to the column AOD.
2. Vertical Transport of Aerosol Particles across Mountain Topography near the Los Angeles Basin
Murray, J. J.; Schill, S.; Freeman, S.; Bertram, T. H.; Lefer, B. L.
2015-12-01
Transport of aerosol particles is known to affect air quality and is largely dependent on the characteristic topography of the surrounding region. To characterize this transport, aerosol number distributions were collected with an Ultra-High Sensitivity Aerosol Spectrometer (UHSAS, DMT) during the 2015 NASA Student Airborne Research Program (SARP) in and around the Los Angeles Basin in Southern California. Increases in particle number concentration and size were observed over mountainous terrain north of Los Angeles County. Chemical analysis and meteorological lagrangian trajectories suggest orographic lifting processes, known as the "chimney effect". Implications for spatial transport and distribution will be discussed.
3. Identifying Metals as Marker for Waste Burning Aerosol Particles in New Delhi
Kumar, Sudhanshu
2012-07-01
{Identifying Metals as Marker for Waste Burning Aerosol Particles in New Delhi } Tracing of aerosol sources is an important task helpful for making control strategy, and for climate change study. However, it is a difficult job as aerosols have several sources, involve in complex atmospheric processing, degradation and removal processes. Several approaches have been used for this task, e.g., models, which are based on the input of chemical species; stable- and radio-isotope compositions of certain species; chemical markers in which trace metals are the better options because they persist in atmosphere until the life of a particle. For example, K and Hg are used for biomass and coal burning tracings, respectively. Open waste burning has recently been believed to be a considerable source of aerosols in several mega cities in India and China. To better understand this source contribution in New Delhi aerosols, we have conducted aerosol sampling at a landfill site (Okhla), and in proximity (within 1 km distance) of this site. Aerosol filter samples were acid digested in microwave digestion system and analyzed using inductively coupled plasma -- high resolution mass spectrometry (ICP-HRMS) for getting metal signatures in particles. The metals, e.g., Sn, Sb and As those are found almost negligible in remote aerosols, are maximized in these waste burning aerosols. Sample collected in other location of New Delhi also shows the considerable presence of these metals in particles. Preliminary studies of isotopic ratios of these metals suggested that these metals, especially Sn can be used as marker for tracing the open waste burning sources of aerosols in New Delhi.
4. Physicochemical characterization of Capstone depleted uranium aerosols II: particle size distributions as a function of time.
PubMed
Cheng, Yung Sung; Kenoyer, Judson L; Guilmette, Raymond A; Parkhurst, Mary Ann
2009-03-01
The Capstone Depleted Uranium (DU) Aerosol Study, which generated and characterized aerosols containing DU from perforation of armored vehicles with large-caliber DU penetrators, incorporated a sampling protocol to evaluate particle size distributions. Aerosol particle size distribution is an important parameter that influences aerosol transport and deposition processes as well as the dosimetry of the inhaled particles. These aerosols were collected on cascade impactor substrates using a pre-established time sequence following the firing event to analyze the uranium concentration and particle size of the aerosols as a function of time. The impactor substrates were analyzed using proportional counting, and the derived uranium content of each served as input to the evaluation of particle size distributions. Activity median aerodynamic diameters (AMADs) of the particle size distributions were evaluated using unimodal and bimodal models. The particle size data from the impactor measurements were quite variable. Most size distributions measured in the test based on activity had bimodal size distributions with a small particle size mode in the range of between 0.2 and 1.2 microm and a large size mode between 2 and 15 microm. In general, the evolution of particle size over time showed an overall decrease of average particle size from AMADs of 5 to 10 microm shortly after perforation to around 1 microm at the end of the 2-h sampling period. The AMADs generally decreased over time because of settling. Additionally, the median diameter of the larger size mode decreased with time. These results were used to estimate the dosimetry of inhaled DU particles.
5. Contrasting the Evaporation and Condensation of Water from Glassy and Amorphous Aerosol Particles
Reid, J. P.; Bones, D. L.; Power, R.; Lienhard, D.; Krieger, U. K.
2012-04-01
The partitioning of water between the condensed and gas phases in atmospheric aerosol is usually assumed to occur instantaneously and to be regulated by solution thermodynamics. However, the persistence of high viscosity, glassy and amorphous aerosol to low relative humidity without crystallisation occurring is now widely recognised, suggesting that the timescale for water transport to or from the particle during condensation or evaporation may be significant. A kinetic limitation on water transport could have important implications for understanding hygroscopic growth measurements made on ambient particles, the ability of particles to act as ice nuclei or cloud condensation nuclei, the kinetics of chemical aging/heterogeneous chemistry, and the rate or condensation/evaporation of semi-volatile organic components. In this study we will report on measurements of the timescale of water transport to and from glassy aerosol and ultra-high viscosity solution droplets using aerosol optical tweezers to investigate the time-response of single particles to changes in relative humidity. As a benchmark system, mixed component aerosol particles containing sucrose and sodium chloride have been used; varying the mole fractions of the two solutes allows a wide range of solution viscosities to be studied. We will show that coarse particles can take many thousands of seconds to equilibrate in size and that the timescale correlates with the estimated bulk viscosity of the particle. We will also confirm that significant inhomogeneities in particle composition can be established during evaporation or condensation. Using the experimental data to benchmark a model for equilibration time, predictions can be made of the timescale for the equilibration of accumulation mode particles during water condensation or evaporation and these predictions will be described and their significance explored. Finally, the coalescence dynamics of highly viscous aerosol particles will be reported
6. Physicochemical Characterization of Capstone Depleted Uranium Aerosols II: Particle Size Distributions as a Function of Time
SciTech Connect
Cheng, Yung-Sung; Kenoyer, Judson L.; Guilmette, Raymond A.; Parkhurst, MaryAnn
2009-03-01
The Capstone Depleted Uranium (DU) Aerosol Study, which generated and characterized aerosols containing depleted uranium from perforation of armored vehicles with large-caliber DU penetrators, incorporated a sampling protocol to evaluated particle size distributions. Aerosol particle size distribution is an important parameter that influences aerosol transport and deposition processes as well as the dosimetry of the inhaled particles. These aerosols were collected on cascade impactor substrates using a pre-established time sequence following the firing event to analyze the uranium concentration and particle size of the aerosols as a function of time. The impactor substrates were analyzed using beta spectrometry, and the derived uranium content of each served as input to the evaluation of particle size distributions. Activity median aerodynamic diameters (AMADs) of the particle size distributions were evaluated using unimodal and bimodal models. The particle size data from the impactor measurements was quite variable. Most size distributions measured in the test based on activity had bimodal size distributions with a small particle size mode in the range of between 0.2 and 1.2 um and a large size mode between 2 and 15 um. In general, the evolution of particle size over time showed an overall decrease of average particle size from AMADs of 5 to 10 um shortly after perforation to around 1 um at the end of the 2-hr sampling period. The AMADs generally decreased over time because of settling. Additionally, the median diameter of the larger size mode decreased with time. These results were used to estimate the dosimetry of inhaled DU particles.
7. Size Resolved Measurements of Springtime Aerosol Particles over the Northern South China Sea
NASA Technical Reports Server (NTRS)
Atwood, Samuel A.; Reid, Jeffrey S.; Kreidenweis, Sonia M.; Cliff, Stephen S.; Zhao, Yongjing; Lin, Neng-Huei; Tsay, Si-Chee; Chu, Yu-Chi; Westphal, Douglas L.
2012-01-01
Large sources of aerosol particles and their precursors are ubiquitous in East Asia. Such sources are known to impact the South China Sea (henceforth SCS), a sometimes heavily polluted region that has been suggested as particularly vulnerable to climate change. To help elucidate springtime aerosol transport into the SCS, an intensive study was performed on the remote Dongsha (aka Pratas) Islands Atoll in spring 2010. As part of this deployment, a Davis Rotating-drum Uniform size-cut Monitor (DRUM) cascade impactor was deployed to collect size-resolved aerosol samples at the surface that were analyzed by X-ray fluorescence for concentrations of selected elements. HYSPLIT backtrajectories indicated that the transport of aerosol observed at the surface at Dongsha was occurring primarily from regions generally to the north and east. This observation was consistent with the apparent persistence of pollution and dust aerosol, along with sea salt, in the ground-based dataset. In contrast to the sea-level observations, modeled aerosol transport suggested that the westerly flow aloft (w700 hPa) transported smoke-laden air toward the site from regions from the south and west. Measured aerosol optical depth at the site was highest during time periods of modeled heavy smoke loadings aloft. These periods did not coincide with elevated aerosol concentrations at the surface, although the model suggested sporadic mixing of this free-tropospheric aerosol to the surface over the SCS. A biomass burning signature was not clearly identified in the surface aerosol composition data, consistent with this aerosol type remaining primarily aloft and not mixing strongly to the surface during the study. Significant vertical wind shear in the region also supports the idea that different source regions lead to varying aerosol impacts in different vertical layers, and suggests the potential for considerable vertical inhomogeneity in the SCS aerosol environment.
8. Micro-physical properties of carbonaceous aerosol particles generated by laser ablation of a graphite target
Ajtai, T.; Utry, N.; Pintér, M.; Tápai, Cs.; Kecskeméti, G.; Smausz, T.; Hopp, B.; Bozóki, Z.; Szabó, G.
2014-09-01
In this work the authors propose laser ablation as a highly versatile tool for carbonaceous aerosol generation. The generated carbonaceous particles can be used as a model aerosol for atmospheric black carbon. Various microphysical properties including mass concentration, size distribution and morphology of aerosol particles generated by laser ablation of a high purity graphite sample were investigated in detail. These measurements proved that the proposed method can be used to generate both primary particles and fractal aggregates with a high yield. As a further advantage of the method the size distribution of the generated aerosol can cover a wide range, and can be tuned accurately with laser fluence, the ambient composition or with the volumetric flow rate of the carrier gas.
9. Particle Characterization and Ice Nucleation Efficiency of Field-Collected Aerosol Particles
Wang, B.; Gilles, M. K.; Laskin, A.; Moffet, R.; Nizkorodov, S.; Roedel, T.; Sterckx, L.; Tivanski, A.; Knopf, D. A.
2011-12-01
Atmospheric ice formation by heterogeneous nucleation is one of the least understood processes resulting in cirrus and mixed-phase clouds which affect the global radiation budget, the hydrological cycle, and water vapor distribution. In particular, how organic aerosol affect ice nucleation is not well understood. Here we report on heterogeneous ice nucleation from particles collected during the CalNex campaign at the Caltech campus site, Pasadena, on May 19, 2010 at 6am-12pm (A2) and 12pm-6pm (A3) and May 23 at 6am-12pm (B2) and 6pm-12am (B4). The ice nucleation onsets and water uptake were determined as a function of temperature (200-273 K) and relative humidity with respect to ice (RHice). The ice nucleation efficiency was related to the particle chemical composition. Single particle characterization was provided by using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). The STXM/NEXAFS analysis indicates that the morning sample (A2) constitutes organic particles and organic particles with soot and inorganic inclusions. The afternoon sample (A3) is dominated by organic particles with a potentially higher degree of oxidation associated with soot. The B2 sample shows a higher number fraction of magnesium-containing particle indicative of a marine source and ~93% of the particles contained sulfur besides oxygen and carbon as derived from CCSEM/EDX analysis. The B4 sample lacks the strong marine influence and shows higher organic content. Above 230 K, we observed water uptake followed by condensation freezing at mean RH of 93-100% and 89-95% for A2 and A3, respectively. This indicates that the aged A3 particles are efficient ice nuclei (IN) for condensation freezing. Below 230 K A2 and A3 induced deposition ice nucleation between 125-155% RHice (at mean values of 134-150% RHice). The B2 and B4
10. Cloud droplet activation through oxidation of organic aerosol influenced by temperature and particle phase state
Slade, Jonathan H.; Shiraiwa, Manabu; Arangio, Andrea; Su, Hang; Pöschl, Ulrich; Wang, Jian; Knopf, Daniel A.
2017-02-01
Chemical aging of organic aerosol (OA) through multiphase oxidation reactions can alter their cloud condensation nuclei (CCN) activity and hygroscopicity. However, the oxidation kinetics and OA reactivity depend strongly on the particle phase state, potentially influencing the hydrophobic-to-hydrophilic conversion rate of carbonaceous aerosol. Here, amorphous Suwannee River fulvic acid (SRFA) aerosol particles, a surrogate humic-like substance (HULIS) that contributes substantially to global OA mass, are oxidized by OH radicals at different temperatures and phase states. When oxidized at low temperature in a glassy solid state, the hygroscopicity of SRFA particles increased by almost a factor of two, whereas oxidation of liquid-like SRFA particles at higher temperatures did not affect CCN activity. Low-temperature oxidation appears to promote the formation of highly-oxygenated particle-bound fragmentation products with lower molar mass and greater CCN activity, underscoring the importance of chemical aging in the free troposphere and its influence on the CCN activity of OA.
11. Uptake of HNO3 to Deliquescent Sea-Salt and Mineral Dust Aerosol Particles
Guimbaud, C.; Vlassenko, A.; Gaggeler, H.; Ammann, M.
2002-12-01
Uptake of HNO3 to aerosol particles is an important removal pathway of nitrogen oxides in the troposphere. Uptake of HNO3 to deliquescent sea-salt aerosol particles was studied in an aerosol flow reactor. Submicron sea-salt particles were used to avoid diffusion limitation in the gas-phase at atmospheric pressure. To overcome the sensitivity problems associated with low amount of reactants processed in such low aerosol masses, we used the short-lived radioactive tracer 13N to label the trace gas molecules at very low concentration. Uptake of HNO3 to deliquescent sea-salt particles was studied under a wide range of HNO3 concentration. Between 1 and 60 ppbv, the uptake coefficient was constant at 0.5+/-0.2 within the first few seconds, whereas at higher concentrations of about 600ppbv, the uptake coefficient rapidly dropped to 0.1 after about 1 second. This drop was due to complete release of chloride as HCl. The equilibrium conditions for these experiments were explored using the North American Aerosol Inorganics (AIM) model, which accounts for the activities of the concentrated solution of the deliquescent aerosol. It is concluded that the rates of uptake at low concentration were limited by the mass accommodation coefficient as both the diffusion in the liquid phase or the rate of release of HCl were not rate limiting. Using an identical approach, we started to investigate the uptake of HNO3 to mineral dust aerosol particles in a similar flow reactor, and first results will be presented. References Ammann, M, Using 13N as tracer in heterogeneous atmospheric chemistry experiments, Radiochim. Acta., 89, 831-838, 2001 Guimbaud, C., F., Arens, L., Gutzwiller, H.W, Gäggeler, and M. Ammann, Uptake of HNO3 to Deliquescent Sea-Salt Aerosol Particles, Atmos. Chem. Phys. Discuss., 2, 739-763, 2002
12. Hygroscopic growth of urban aerosol particles during the 2009 Mirage-Shanghai Campaign
Ye, Xingnan; Tang, Chen; Yin, Zi; Chen, Jianmin; Ma, Zhen; Kong, Lingdong; Yang, Xin; Gao, Wei; Geng, Fuhai
2013-01-01
The hygroscopic properties of submicrometer urban aerosol particles were studied during the 2009 Mirage-Shanghai Campaign. The urban aerosols were composed of more-hygroscopic and nearly-hydrophobic particles, together with a trace of less-hygroscopic particles. The mean hygroscopicity parameter κ of the more-hygroscopic mode varied in the range of 0.27-0.39 depending on particle size. The relative abundance of the more-hygroscopic particles at any size was ca. 70%, slightly increasing with particle size. The number fraction of the nearly-hydrophobic particles fluctuated between 0.1 and 0.4 daily, in accordance with traffic emissions and atmospheric diffusion. The results from relative humidity dependence on hygroscopic growth and chemical analysis of fine particles indicated that particulate nitrate formation through the homogenous gas-phase reaction was suppressed under ammonia-deficient atmosphere in summer whereas the equilibrium was broken by more available NH3 during adverse meteorological conditions.
13. Middle East measurements of concentration and size distribution of aerosol particles for coastal zones
Bendersky, Sergey; Kopeika, Norman S.; Blaunstein, Natan S.
2005-10-01
Recently, an extension of the Navy Aerosol Model (NAM) was proposed based on analysis of an extensive series of measurements at the Irish Atlantic Coast and at the French Mediterranean Coast. We confirm the relevance of that work for the distant eastern Meditteranean and extend several coefficients of that coastal model, proposed by Piazzola et al. for the Meditteranean Coast (a form of the Navy Aerosol Model), to midland Middle East coastal environments. This analysis is based on data collected at three different Middle East coastal areas: the Negev Desert (Eilat) Red Sea Coast, the Sea of Galilee (Tiberias) Coast, and the Mediterranean (Haifa) Coast. Aerosol size distributions are compared with those obtained through measurements carried out over the Atlantic, Pacific, and Indian Ocean Coasts, and Mediterranean, and Baltic Seas Coasts. An analysis of these different results allows better understanding of the similarities and differences between different coastal lake, sea, and open ocean zones. It is shown that in the coastal regions in Israel, compared to open ocean and other sea zones, larger differences in aerosol particle concentration are observed. The aerosol particle concentrations and their dependences on wind speed for these coastal zones are analyzed and discussed. We propose to classify the aerosol distribution models to either: 1. a coastal model with marine aerosol domination; 2. a coastal model with continental aerosol domination (referred to as midland coast in this work); or 3. a coastal model with balanced marine and continental conditions.
14. Modeling of microphysics and optics of aerosol particles in the marine environments
2013-05-01
We present a microphysical model for the surface layer marine and coastal atmospheric aerosols that is based on long-term observations of size distributions for 0.01-100 μm particles. The fundamental feature of the model is a parameterization of amplitudes and widths for aerosol modes of the aerosol size distribution function (ASDF) as functions of fetch and wind speed. The shape of ASDF and its dependence on meteorological parameters, height above sea level (H), fetch (X), wind speed (U) and relative humidity (RH), are investigated. At present, the model covers the ranges H = 0 - 25 m, U = 3 - 18 km s-1, X ≤ 120 km and RH = 40 - 98%. The latest version of the Marine Aerosol Extinction Profiles model (MaexPro) is described and applied for the computation and analysis of the spectral profiles of aerosol extinction coefficients α(λ) in the wavelength band λ = 0.2-12 μm. MaexPro is based on the aforementioned aerosol model assuming spherically shaped aerosol particles and the well-known Mie theory. The spectral profiles of α(λ) calculated by MaexPro are in good agreement with observational data and the numerical results. Moreover, MaexPro was found to be an accurate and reliable tool for investigating the optical properties of atmospheric aerosols.
15. Formation of highly porous aerosol particles by atmospheric freeze-drying in ice clouds
Rudich, Yinon; Adler, Gabriela; Koop, Thomas; Taraniuk, Ilya; Moise, Tamar; Koren, Ilan; Heiblum, Reuven; Haspel, Carynelisa
2014-05-01
In cold high altitude cirrus clouds and anvils of high convective clouds in the tropics and mid-latitudes, ice partciles that are exposed to subsaturation conditions with respect to ice can sublimate, leaving behind residual modified aerosols. This freeze-drying process can occur in various types of clouds. In this talk we will describe experiements that simulate the atmospheric freeze-drying cycle of aerosols. We find that aerosols with high organic content can form highly porous particles (HPA) with a larger diameter and a lower density than the initial homogenous aerosol following ice subliation. We attribute this morphology change to phase separation upon freezing followed by a glass transition of the organic material that can preserve a porous structure follwoing ice sublimation. We find that the highly porous aerosol scatter solar light less efficiently than non-porous aerosol particles. A porous structure may explain the previously observed enhancement in ice nucleation efficiency of glassy organic particles. These observations may have implications for subsequent cloud formation cycles and aerosol albedo near cloud edges.
16. The PBAP remodeling complex is required for histone H3.3 replacement at chromatin boundaries and for boundary functions.
PubMed
Nakayama, Takahiro; Shimojima, Tsukasa; Hirose, Susumu
2012-12-01
Establishment and maintenance of epigenetic memories are essential for development. Replacement of canonical histone H3 by its variant H3.3 has been implicated in cellular memory. Drosophila sequence-specific DNA-binding protein GAGA factor and a chromatin factor FACT direct H3.3 replacement in conjunction with H3.3-specific chaperone HIRA at chromatin boundaries to counteract the spreading of silent chromatin. However, little is known about which ATP-driven chromatin remodeling factor is responsible for the H3.3 replacement at chromatin boundaries. Here, we report that GAGA factor associates with the Polybromo-associated Brm (PBAP) remodeling complex, which consists of many Trithorax group proteins, and recruits this complex to chromatin boundaries d1 (which is downstream of w), the Fab-7 DNase-hypersensitive site (HS) 1 of Abd-B and the bxd region of Ubx. Trl-encoding GAGA factor, brm and polybromo/bap180 mutations compromise the H3.3 replacement and boundary functions in a synergistic manner. Furthermore, Polybromo is necessary for generation of the DNase HS at d1, and HIRA functions to restore the alteration. Taken together, we propose that FACT and PBAP complexes are recruited to chromatin boundaries in a GAGA factor-dependent manner, and are needed for H3.3 replacement to execute boundary functions. Our results provide new insight into the function of the trithorax group during development.
17. Evidence for chromatin-remodeling complex PBAP-controlled maintenance of the Drosophila ovarian germline stem cells.
PubMed
He, Jie; Xuan, Tao; Xin, Tianchi; An, Hongbo; Wang, Jinye; Zhao, Gengchun; Li, Mingfa
2014-01-01
In the Drosophila oogenesis, germline stem cells (GSCs) continuously self-renew and differentiate into daughter cells for consecutive germline lineage commitment. This developmental process has become an in vivo working platform for studying adult stem cell fate regulation. An increasing number of studies have shown that while concerted actions of extrinsic signals from the niche and intrinsic regulatory machineries control GSC self-renewal and germline differentiation, epigenetic regulation is implicated in the process. Here, we report that Brahma (Brm), the ATPase subunit of the Drosophila SWI/SNF chromatin-remodeling complexes, is required for maintaining GSC fate. Removal or knockdown of Brm function in either germline or niche cells causes a GSC loss, but does not disrupt normal germline differentiation within the germarium evidenced at the molecular and morphological levels. There are two Drosophila SWI/SNF complexes: the Brm-associated protein (BAP) complex and the polybromo-containing BAP (PBAP) complex. More genetic studies reveal that mutations in polybromo/bap180, rather than gene encoding Osa, the BAP complex-specific subunit, elicit a defect in GSC maintenance reminiscent of the brm mutant phenotype. Further genetic interaction test suggests a functional association between brm and polybromo in controlling GSC self-renewal. Taken together, studies in this paper provide the first demonstration that Brm in the form of the PBAP complex functions in the GSC fate regulation.
18. Formation characteristics of aerosol particles from pulverized coal pyrolysis in high-temperature environments.
PubMed
Chen, Wei-Hsin; Du, Shan-Wen; Yang, Hsi-Hsien; Wu, Jheng-Syun
2008-05-01
The formation characteristics of aerosol particles from pulverized coal pyrolysis in high temperatures are studied experimentally. By conducting a drop-tube furnace, fuel pyrolysis processes in industrial furnaces are simulated in which three different reaction temperatures of 1000, 1200, and 1400 degrees C are considered. Experimental observations indicate that when the reaction temperature is 1000 degrees C, submicron particles are produced, whereas the particle size is dominated by nanoscale for the temperature of 1400 degrees C. Thermogravimetric analysis of the aerosol particles stemming from the pyrolysis temperature of 1000 degrees C reveals that the thermal behavior of the aerosol is characterized by a three-stage reaction with increasing heating temperature: (1) a volatile-reaction stage, (2) a weak-reaction stage, and (3) a soot-reaction stage. However, with the pyrolysis temperature of 1400 degrees C, the volatile- and weak-reaction stages almost merge together and evolve into a chemical-frozen stage. The submicron particles (i.e., 1000 degrees C) are mainly composed of volatiles, tar, and soot, with the main component of the nanoscale particles (i.e., 1400 degrees C) being soot. The polycyclic aromatic hydrocarbons (PAHs) contained in the aerosols are also analyzed. It is found that the PAH content in generated aerosols decreases dramatically as the pyrolysis temperature increases.
19. [Hygroscopic Properties of Aerosol Particles in North Suburb of Nanjing in Spring].
PubMed
Xu, Bin; Zhang, Ze-feng; Li, Yan-weil; Qin, Xin; Miao, Qing; Shen, Yan
2015-06-01
The hygroscopic properties of submicron aerosol particles have significant effects on spectral distribution, CCN activation, climate forcing, human health and so on. A Hygroscopic Tandem Differential Mobility Analyzer (HTDMA) was utilized to analyze the hygroscopic properties of aerosol particles in the northern suburb of Nanjing during 16 April to 21 May, 2014. At relative humidity (RH) of 90%, for particles with dry diameters 30-230 nm, the probability distribution of GF (GF-PDF) shows a distinct bimodal pattern, with a dominant more-hygroscopic group and a smaller less-hygroscopic group. A contrast analysis between day and night suggests that, aerosol particles during day time have a stronger hygroscopicity and a higher number fraction of more-hygroscopic group than that at night overall. Aerosol particles during night have a higher degree of externally mixed state. Backward trajectory analysis using HYSPLIT mode reveals that, the sampling site is mainly affected by three air masses. For aitken nuclei, northwest continental air masses experience a longer aging process and have a stronger hygroscopicity. For condensation nuclei, east air masses have a stronger hygroscopicity and have a higher number fraction of more-hygroscopic group. Aerosol particles in local air masses have a high number fraction of more-hygroscopic group in the whole diameter range.
20. Hygroscopicity of aerosol particles and CCN activity of nearly hydrophobic particles in the urban atmosphere over Japan during summer
Ogawa, Shuhei; Setoguchi, Yoshitaka; Kawana, Kaori; Nakayama, Tomoki; Ikeda, Yuka; Sawada, Yuuki; Matsumi, Yutaka; Mochida, Michihiro
2016-06-01
We investigated the hygroscopicity of 150 nm particles and the number-size distributions and the cloud condensation nuclei (CCN) activity of nearly hydrophobic particles in aerosols over Nagoya, Japan, during summer. We analyzed the correlations between the number concentrations of particles in specific hygroscopic growth factor (g) ranges and the mass concentrations of chemical components. This analysis suggests the association of nearly hydrophobic particles with hydrocarbon-like organic aerosol, elemental carbon and semivolatile oxygenated organic aerosol (SV-OOA), that of less hygroscopic particles with SV-OOA and nitrate and that of more hygroscopic particles with low-volatile oxygenated organic aerosol (LV-OOA) and sulfate. The hygroscopicity parameter (κ) of organics was derived based on the g distributions and chemical composition of 150 nm particles. The κ of the organics correlated positively with the fraction of the total organic mass spectral signal at m/z 44 and the volume fraction of the LV-OOA to the organics, indicating that organics with highly oxygenated structures including carboxylic acid groups contribute to the water uptake. The number-size distributions of the nearly hydrophobic particles with g around 1.0 and 1.1 correlated with the mass concentrations of chemical components. The results show that the chemical composition of the particles with g around 1.0 was different between the Aitken mode and the accumulation mode size ranges. An analysis for a parameter Fmax of the curves fitted to the CCN efficiency spectra of the particles with g around 1.0 suggests that the coating by organics associated with SV-OOA elevated the CCN activity of these particles.
1. Autofluorescence of atmospheric bioaerosols - Biological standard particles and the influence of environmental conditions
Pöhlker, Christopher; Huffman, J. Alex; Förster, Jan-David; Pöschl, Ulrich
2013-04-01
Primary biological aerosol particles (PBAP) such as pollen, fungal spores, bacteria, biogenic polymers and debris from larger organisms are known to influence atmospheric chemistry and physics, the biosphere and public health. PBAP can account for up to ~30% of fine and up to ~70% of coarse particulate matter in urban, rural and pristine environment and are released with estimated emission rates of up to ~1000 Tg/a [1]. Continuous measurements of the abundance, variability and diversity of PBAP have been difficult until recently, however. The application of on-line instruments able to detect autofluorescence from biological particles in real-time has been a promising development for the measurement of PBAP concentrations and fluxes in different environments [2,3]. The detected fluorescent biological aerosol particles (FBAP) can be regarded as a subset of PBAP, although the exact relationship between PBAP and FBAP is still being investigated. Autofluorescence of FBAP is usually a superposition of fluorescence from a mixture of individual fluorescent molecules (fluorophores). Numerous biogenic fluorophores such as amino acids (e.g., tryptophan, tyrosine), coenzymes (e.g., NAD(P)H, riboflavin) and biopolymers (e.g., cellulose) emit fluorescent light due to heterocyclic aromatic rings or conjugated double bonds within their molecular structures. The tryptophan emission peak is a common feature of most bioparticles because the amino acid is a constituent of many proteins and peptides. The influence of the coenzymes NAD(P)H and riboflavin on the autofluorescence of bacteria can be regarded as an indicator for bacterial metabolism and has been utilized to discriminate between viable and non-viable organisms [4]. However, very little information is available about other essential biofluorophores in fungal spores and pollen. In order to better understand the autofluorescence behavior of FBAP, we have used fluorescence spectroscopy and fluorescence microscopy to analyze
2. Characterization of a Quadrotor Unmanned Aircraft System for Aerosol-Particle-Concentration Measurements.
PubMed
Brady, James M; Stokes, M Dale; Bonnardel, Jim; Bertram, Timothy H
2016-02-02
High-spatial-resolution, near-surface vertical profiling of atmospheric chemical composition is currently limited by the availability of experimental platforms that can sample in constrained environments. As a result, measurements of near-surface gradients in trace gas and aerosol particle concentrations have been limited to studies conducted from fixed location towers or tethered balloons. Here, we explore the utility of a quadrotor unmanned aircraft system (UAS) as a sampling platform to measure vertical and horizontal concentration gradients of trace gases and aerosol particles at high spatial resolution (1 m) within the mixed layer (0-100 m). A 3D Robotics Iris+ autonomous quadrotor UAS was outfitted with a sensor package consisting of a two-channel aerosol optical particle counter and a CO2 sensor. The UAS demonstrated high precision in both vertical (±0.5 m) and horizontal positions (±1 m), highlighting the potential utility of quadrotor UAS drones for aerosol- and trace-gas measurements within complex terrain, such as the urban environment, forest canopies, and above difficult-to-access areas such as breaking surf. Vertical profiles of aerosol particle number concentrations, acquired from flights conducted along the California coastline, were used to constrain sea-spray aerosol-emission rates from coastal wave breaking.
3. Particle-Resolved Modeling of Aerosol Mixing State in an Evolving Ship Plume
Riemer, N. S.; Tian, J.; Pfaffenberger, L.; Schlager, H.; Petzold, A.
2011-12-01
The aerosol mixing state is important since it impacts the particles' optical and CCN properties and thereby their climate impact. It evolves continuously during the particles' residence time in the atmosphere as a result of coagulation with other particles and condensation of secondary aerosol species. This evolution is challenging to represent in traditional aerosol models since they require the representation of a multi-dimensional particle distribution. While modal or sectional aerosol representations cannot practically resolve the aerosol mixing state for more than a few species, particle-resolved models store the composition of many individual aerosol particles directly. They thus sample the high-dimensional composition state space very efficiently and so can deal with tens of species, fully resolving the mixing state. Here we use the capabilities of the particle-resolved model PartMC-MOSAIC to simulate the evolution of particulate matter emitted from marine diesel engines and compare the results to aircraft measurements made in the English Channel in 2007 as part of the European campaign QUANTIFY. The model was initialized with values of gas concentrations and particle size distributions and compositions representing fresh ship emissions. These values were obtained from a test rig study in the European project HERCULES in 2006 using a serial four-stroke marine diesel engine operating on high-sulfur heavy fuel oil. The freshly emitted particles consisted of sulfate, black carbon, organic carbon and ash. We then tracked the particle population for several hours as it evolved undergoing coagulation, dilution with the background air, and chemical transformations in the aerosol and gas phase. This simulation was used to compute the evolution of CCN properties and optical properties of the plume on a per-particle basis. We compared our results to size-resolved data of aged ship plumes from the QUANTIFY Study in 2007 and showed that the model was able to reproduce
4. Variation in penetration of submicrometric particles through electrostatic filtering facepieces during exposure to paraffin oil aerosol.
PubMed
Plebani, Carmela; Listrani, Stefano; Tranfo, Giovanna; Tombolini, Francesca
2012-01-01
5. Discrimination and classification of bio-aerosol particles using optical spectroscopy and scattering
Eversole, Jay D.
2011-03-01
For more than a decade now, there has been significant emphasis for development of sensors of agent aerosols, especially for biological warfare (BW) agents. During this period, the Naval Research Laboratory (NRL) and other labs have explored the application of optical and spectroscopic methods relevant to biological composition discrimination to aerosol particle characterization. I will first briefly attempt to establish the connection between sensor performance metrics which are statistically determined, and aerosol particle measurements through the use of computational models, and also describe the challenge of ambient background characterization that would be needed to establish more reliable and deterministic sensor performance predictions. Greater attention will then be devoted to a discussion of basic particle properties and their measurement. The NRL effort has adopted an approach based on direct measurements on individual particles, principally of elastic scatter and laser-induced fluorescence (LIF), rather than populations of particles. The development of a LIF instrument using two sequential excitation wavelengths to detect fluorescence in discrete spectral bands will be described. Using this instrument, spectral characteristics of particles from a variety of biological materials including BW agent surrogates, as well as other calibration'' particles and some known ambient air constituents will be discussed in terms of the dependence of optical signatures on aerosol particle composition, size and incident laser fluence. Comparison of scattering and emission measurements from particles composed of widely different taxa, as well as from similar species under different growth conditions highlight the difficulties of establishing ground truth for complex biological material compositions. One aspect that is anticipated to provide greater insight to this type of particle classification capability is the development of a fundamental computational model of
6. High-efficiency particulate air filter test stand and aerosol generator for particle loading studies.
PubMed
Arunkumar, R; Hogancamp, Kristina U; Parsons, Michael S; Rogers, Donna M; Norton, Olin P; Nagel, Brian A; Alderman, Steven L; Waggoner, Charles A
2007-08-01
This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30 x 30 x 29 cm(3) nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5 to 12 standard m(3)/min. Relative humidity levels are controllable from 5%-90% and the temperature of the aerosol stream is variable from ambient to 150 degrees C. Test aerosols are produced through spray drying source material solutions that are introduced into a heated stainless steel evaporation chamber through an air-atomizing nozzle. Regulation of the particle size distribution of the aerosol challenge is achieved by varying source solution concentrations and through the use of a postgeneration cyclone. The aerosol generation system is unique in that it facilitates the testing of standard HEPA filters at and beyond rated media velocities by consistently providing, into a nominal flow of 7 standard m(3)/min, high mass concentrations (approximately 25 mg/m(3)) of dry aerosol streams having count mean diameters centered near the most penetrating particle size for HEPA filters (120-160 nm). Aerosol streams that have been generated and characterized include those derived from various concentrations of KCl, NaCl, and sucrose solutions. Additionally, a water insoluble aerosol stream in which the solid component is predominantly iron (III) has been produced. Multiple ports are available on the test stand for making simultaneous aerosol measurements upstream and downstream of the test filter. Types of filter performance related studies that can be performed using this test stand system include filter lifetime studies, filtering efficiency testing, media velocity testing, evaluations under high mass loading and high humidity conditions, and determination of the downstream particle size distributions.
7. The generation of diesel exhaust particle aerosols from a bulk source in an aerodynamic size range similar to atmospheric particles
PubMed Central
Cooney, Daniel J; Hickey, Anthony J
2008-01-01
The influence of diesel exhaust particles (DEP) on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process. PMID:19337412
8. LOAC (Light Optical Particle Counter): a new small aerosol counter with particle characterization capabilities for surface and airborne measurements
Renard, Jean-Baptiste; Berthet, Gwenael; Jégou, Fabrice; Jeannot, Matthieu; Jourdain, Line; Dulac, François; Mallet, Marc; Dupont, Jean-Charles; Thaury, Claire; Tonnelier, Thierry; Verdier, Nicolas; Charpentier, Patrick
2013-04-01
The determination of the size distribution of tropospheric and stratospheric aerosols with conventional optical counters is difficult when different natures of particles are present (droplets, soot, mineral dust, secondary organic or mineral particles...). Also, a light and cheap aerosol counter that can be used at ground, onboard drones or launched under all kinds of atmospheric balloons can be very useful during specific events as volcanic plumes, desert dust transport or local pollution episodes. These goals can be achieved thanks to a new generation of aerosol counter, called LOAC (Light Optical Aerosol Counter). The instrument was developed in the frame of a cooperation between French scientific laboratories (CNRS), the Environnement-SA and MeteoModem companies and the French Space Agency (CNES). LOAC is a small optical particle counter/sizer of ~250 grams, having a low electrical power consumption. The measurements are conducted at two scattering angles. The first one, at 12°, is used to determine the aerosol particle concentrations in 19 size classes within a diameter range of 0.3-100 micrometerers. At such an angle close to forward scattering, the signal is much more intense and the measurements are the least sensitive to the particle nature. The second angle is at 60°, where the scattered light is strongly dependent on the particle refractive index and thus on the nature of the aerosols. The ratio of the measurements at the two angles is used to discriminate between the different types of particles dominating the nature of the aerosol particles in the different size classes. The sensor particularly discriminates wet or liquid particles, soil dust and soot. Since 2011, we have operated LOAC in various environments (Arctic, Mediterranean, urban and peri-urban…) under different kinds of balloons including zero pressure stratospheric, tethered, drifting tropospheric, and meteorological sounding balloons. For the last case, the total weight of the gondola
9. Isotope Analysis of Individual Aerosol Particles - a New Tool for Studying Heterogeneous Processes
Winterholler, B.; Hoppe, P.; Huth, J.; Andreae, M. O.; Foley, S.
2006-12-01
Sources of atmospheric sulfur and its oxidation pathways are studied by isotope analysis of sulfate particles. conventional gas mass spectrometry averages the isotopic compositions of millions of aerosol grains and, therefore, several different types of sulphur aerosol. The new Cameca NanoSIMS 50 ion microprobe technique permits isotope analyses of individual aerosol particles down to 0.5 μm diameter. Combining the chemical composition and isotopic signature of individual particles enables source apportionment of non-sea-salt (nss) sulfate and elucidating mixing processes between nss sulfate and sea-salt sulfate for each sample. Results from aerosol samples collected in Mace Head (Western Ireland) are presented. These samples represent different airmass types, such as clean marine boundary layer air, moderately polluted air and strongly polluted air transported from the continent. Fresh aerosol preserves the original isotopic signature of sea-salt and nss sulfate in separate particles, the latter being present predominantly in the form of ammonium sulfate. This enables us to identify oxidation of nss sulfate in deliquescent sea salt particles by means of their sulfur isotope ratio. Cloud processing however, leads to a complete homogenization as far as the sulfur isotopic signature is concerned.
10. Limits of DPUI application associated with the number of particles within actinide aerosols.
PubMed
Fritsch, P; Raynaud, P; Blanchin, N; Mièle, A
2007-01-01
Dose per unit intake (DPUI) of radionuclides is obtained using International Commission on Radiological Protection (ICRP) models. After inhalation exposure, the first model calculates the fraction of activity deposited within the different regions of the respiratory tract, assuming that the aerosol contains an infinite number of particles. Using default parameters for workers, an exposure to one annual limit of intake (ALI) corresponds to an aerosol of 239PuO2 containing approximately 1 x 10(6) particles. To reach such an exposure, very low particle number might be involved especially for compounds having a high specific activity. This study provides examples of exposures to actinide aerosols for which the number of particles is too low for a standard application of the ICRP model. These examples, which involve physical studies of aerosols collected at the workplace and interpretation of bioassay data, show that the number of particles of the aerosol can be the main limit for the application of DPUI after inhalation exposure.
11. A rocket-borne mass analyzer for charged aerosol particles in the mesosphere
SciTech Connect
Knappmiller, Scott; Robertson, Scott; Sternovsky, Zoltan; Friedrich, Martin
2008-10-15
An electrostatic mass spectrometer for nanometer-sized charged aerosol particles in the mesosphere has been developed and tested. The analyzer is mounted on the forward end of a rocket and has a slit opening for admitting a continuous sample of air that is exhausted through ports at the sides. Within the instrument housing are two sets of four collection plates that are biased with positive and negative voltages for the collection of negative and positive aerosol particles, respectively. Each collection plate spans about an order of magnitude in mass which corresponds to a factor of 2 in radius. The number density of the charge is calculated from the current collected by the plates. The mean free path for molecular collisions in the mesosphere is comparable to the size of the instrument opening; thus, the analyzer performance is modeled by a Monte Carlo computer code that finds the aerosol particles trajectories within the instrument including both the electrostatic force and the forces from collisions of the aerosol particles with air molecules. Mass sensitivity curves obtained using the computer models are near to those obtained in the laboratory using an ion source. The first two flights of the instrument returned data showing the charge number densities of both positive and negative aerosol particles in four mass ranges.
12. The Humidity Dependence of N2O5 Uptake to Citric Acid Aerosol Particles
Grzinic, G.; Bartels-Rausch, T.; Tuerler, A.; Ammann, M.
2013-12-01
Dinitrogen pentoxide is a significant reactive intermediate in the night time chemistry of nitrogen oxides. Depending on atmospheric conditions it can act either as a NO3 radical reservoir or as a major NOx sink by heterogeneous hydrolysis on aerosol surfaces. As such, it can influence tropospheric ozone production and therefore the oxidative capacity of the atmosphere. The heterogeneous loss of N2O5 to aerosol particles has remained uncertain, and reconciling lab and field data has demonstrated some gaps in our understanding of the detailed mechanism. We used the short-lived radioactive tracer 13N to study N2O5 uptake kinetics on aerosol particles in an aerosol flow reactor at ambient pressure, temperature and relative humidity. Citric acid, representing strongly oxidized polyfunctional organic compounds in atmospheric aerosols, has been chosen as a proxy due to its well established physical properties. Aerosol uptake measurements were performed with citric acid aerosols in a humidity range of 15-75 % RH, within which the uptake coefficient varies between about 0.001 and about 0.02. Taking into account the well established hygroscopic properties of citric acid, we interpret uptake in terms of disproportionation of N2O5 into nitrate ion and nitronium ion and reaction of the latter with liquid water.
13. Submicron Aerosol Characterization of Water by a Differential Mobility Particle Sizer.
DTIC Science & Technology
1987-02-01
relevant to modern science and industry. N *% ~ ~ ~?1 *1?%~%~ 0.0 :~. % % his ’i tl’tt Security Classif ication KIEV WORDS Submricron aerosols Water ...7 :-711 no0 StIHICRON AEROSOL CHARACTERIZATION OF WATER DY A vi1 DIFFERENTIAL NOBILITY PA.. (U) DEFENCE RESEARCH ESTABLISHMENT SUFFIELD RALSTON... WATER BY A DIFFERENTIAL MOBILITY PARTICLE SIZER (U) by B. Kournikakis, A. Gunning, J. Fildes and J. Ho Project No. 251SD EL .TE APR 099?07uD February
14. Digital holography for observing aerosol particles undergoing Brownian motion in microgravity conditions
Prodi, F.; Santachiara, G.; Travaini, S.; Belosi, F.; Vedernikov, A.; Dubois, F.; Queeckers, P.; Legros, J. C.
2006-11-01
Brownian diffusion of aerosol particles was studied in microgravity conditions using a digital holographic velocimeter. Based on digital image processing, the observed volume, recorded on a charge-coupled device (CCD) camera, is reconstructed slice by slice in order to achieve a full focused volume. Three dimensional coordinates of the particles are retrieved by such procedures and particle trajectories are reconstructed by analysing the sequence of the particle position. We deduced that the displacement of particles in microgravity, due to Brownian motion, follows a Gaussian distribution, like at 1 g. Particle sizes obtained from SEM measurements were in good agreement with those calculated from the three dimensional trajectories provided by the holographic microscope.
15. Characterization of lead-containing aerosol particles in Xiamen during and after Spring Festival by single-particle aerosol mass spectrometry.
PubMed
Zhao, Shuhui; Chen, Liqi; Yan, Jinpei; Chen, Hangyu
2017-02-15
To comparatively analyze lead (Pb)-containing particles during and after the Chinese Spring Festival (SF), real-time single-particle aerosol mass spectrometry (SPAMS) was conducted in Xiamen during February 9-19 and March 4-14, 2013. Pb-containing particles were found in 2.4% and 5.3% of the total particle numbers during and after SF, respectively. Based on the SPAMS mass spectral results, the Pb-containing particles were classified into three major types and 11 subtypes: Pb-rich particles comprising Pb-nitrate, Pb-sulfate and Pb-chloride; K-rich particles comprising K-nitrate, K-sulfate, K-metal, K-carbonaceous, K-phosphate, and K-chloride; and metal particles including Fe-rich and Mn-nitrate particles. During SF, lower contributions of Pb-containing particles were due to the effect of the SF holiday. Firework emissions contributed little to the Pb-containing particles. K-rich particles were a major contribution to Pb-containing particles during SF, accounting for approximately 70% of the total number of Pb-containing particles. After SF, significantly increased Pb-containing particles were observed, coincided with NO2 and SO2, due to increased industrial activities and other anthropogenic activities, and Pb-rich particles increased to approximately 50.3% of the total number of Pb-containing particles. Local industrial emissions and the stagnant meteorological conditions resulted in the higher concentrations of Pb-containing particles in the early morning after SF, especially Pb-nitrate particles. This study provides data on the in-situ monitoring of Pb emissions during and after SF and could be helpful for the mitigation of Pb pollution.
16. Simulating the Evolution of Soot Mixing State with a Particle-Resolved Aerosol Model
SciTech Connect
Riemer, Nicole; West, Matt; Zaveri, Rahul A.; Easter, Richard C.
2009-05-05
The mixing state of soot particles in the atmosphere is of crucial importance for assessing their climatic impact, since it governs their chemical reactivity, cloud condensation nuclei activity and radiative properties. To improve the mixing state representation in models, we present a new approach, the stochastic particle-resolved model PartMC-MOSAIC, which explicitly resolves the composition of individual particles in a given population of different types of aerosol particles. This approach accurately tracks the evolution of the mixing state of particles due to emission, dilution, condensation and coagulation. To make this direct stochastic particle-based method practical, we implemented a new multiscale stochastic coagulation method. With this method we achieved optimal efficiency for applications when the coagulation kernel is highly non-uniform, as is the case for many realistic applications. PartMC-MOSAIC was applied to an idealized urban plume case representative of a large urban area to simulate the evolution of carbonaceous aerosols of different types due to coagulation and condensation. For this urban plume scenario we quantified the individual processes that contribute to the aging of the aerosol distribution, illustrating the capabilities of our modeling approach. The results showed for the first time the multidimensional structure of particle composition, which is usually lost in internally-mixed sectional or modal aerosol models.
17. Shapes of internally mixed hygroscopic aerosol particles after deliquescence, and their effect on light scattering
Adachi, Kouji; Freney, Evelyn J.; Buseck, Peter R.
2011-07-01
Hygroscopic aerosol particles change the magnitude of light scattering through condensation and evaporation of water vapor. We collected aerosol particles from two megacities and observed the particle shapes at various values of relative humidity (RH) using an environmental cell within a transmission electron microscope. Many Mexico City samples had sulfate particles that were embedded within weakly hygroscopic organic aerosol, whereas the Los Angeles samples mainly consisted of externally mixed sulfate particles. For the Mexico City samples, when the RH was increased in the microscope, only the sulfate parts deliquesced, but the entire particle did not become spherical, i.e., particles containing deliquescent phases do not necessarily become spherical upon deliquescence. This result conflicts with the assumption used in many models, i.e., that deliquesced particles become spherical. Using a discrete-dipole approximation to calculate light scattering of simulated particles that resemble the observed ones, we show that, for particles >1.0 μm, the spherical-shape assumption used in Mie theory underestimates the light scattering by ˜50%, with the exact value depending on the sizes and relative volumes of the constituent phases.
18. Single-particle characterization of summertime arctic aerosols collected at Ny-Alesund, Svalbard.
PubMed
Geng, Hong; Ryu, Jiyeon; Jung, Hae-Jin; Chung, Hyeok; Ahn, Kang-Ho; Ro, Chul-Un
2010-04-01
Single-particle characterization of summertime Arctic aerosols is useful to understand the impact of air pollutants on the polar atmosphere. In the present study, a quantitative single particle analytical technique, low-Z particle electron probe X-ray microanalysis, was used to characterize 8100 individual particles overall in 16 sets of aerosol samples collected at Ny-Alesund, Svalbard, Norway on 25-31 July, 2007. Based on their X-ray spectral and secondary electron image data of individual particles, 13 particle types were identified, in which particles of marine origin were the most abundant, followed by carbonaceous and mineral dust particles. A number of aged (reacted) sea salt (and mixture) particles produced by the atmospheric reaction of genuine sea-salts, especially with NO(x) or HNO(3), were significantly encountered in almost all the aerosol samples. They greatly outnumbered genuine sea salt particles, implying that the summertime Arctic atmosphere, generally regarded as a clean background environment, is disturbed by anthropogenic air pollutants. The main sources of airborne NO(x) (or HNO(3)) are probably ship emissions around the Arctic Ocean, industry emission from northern Europe and northwestern Siberia, and renoxification of NO(3)(-) within or on the melting snow/ice surface.
19. Anthropogenic monoterpene pollution episodes in a forest environment in association with aerosol particles
Liao, L.; Taipale, R.; Dal Maso, M.; Ehn, M.; Junninen, H.; Nieminen, T.; Kerminen, V.; Kulmala, M. T.
2010-12-01
Monoterpenes (MT) present in troposphere affect atmospheric chemistry and air quality. The oxidation of monoterpenes leading to secondary organic aerosol formation can affect aerosol loadings, and further influence the climate system. Identified sources of MT include biogenic and anthropogenic origins. In this study, we present a four-year set observation of MT to examine: 1. the origin and the quantification of elevated MT concentrations. 2. The influence of enhanced MT emissions on local air chemistry and possible associated pollutants. 3. Possible influence of anthropogenic MT emissions on physical and chemical properties of enhanced aerosol particles. VOC observations were continuously con-ducted using a PTR-MS from Jun. 12 2006 to Sep. 24 2007 and from Jun. 1 2008 to Mar. 3 2009. As an example, MT observed on March 8, 2007 are plotted in Figure 1 along with DMPS. The DMPS spectra show simultaneous elevations of Aitken-mode particles seen as red colors when monoterpenes are dramatically elevated during six short periods on this day. Out of the four-year dataset amounting to 580 days in total, 27.4% of the days showed MT pollution episodes. The sum of the total episode durations is equal to 3.62% time of the whole PTR-MS measurement period. The average concentration of MT was increased from 0.205 to 0.270 ppbv, which roughly results in 32% overestimation of biogenic MT without considering the influence of these anthropogenic emissions. The origin of episodes is mainly from the Korkeakoski sawmill which is ca. 6 km away from the SMEAR II station and 130 degrees South East direction. VOCs are the main pollutants from sawmill. We did not see clear connections between MT and other gas pollutants during MT episodes. The case studies have shown that other associated pollutants may be occasionally emitted. The strong link between anthropogenic MT and aerosol particles suggest that sawmills could be a main source of anthropogenic VOCs, as well as aerosol loading at the
20. Urban organic aerosols measured by single particle mass spectrometry in the megacity of London
Dall'Osto, M.; Harrison, R. M.
2012-05-01
During the month of October 2006, as part of the REPARTEE-I experiment (Regent's Park and Tower Environmental Experiment) an Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed at an urban background location in the city of London, UK. Fifteen particle types were classified, some of which were already discussed (Dall'Osto et al., 2009a,b; Harrison et al., 2012). In this manuscript the origins and properties of four unreported particle types postulated to be due to locally generated aerosols, independent of the air mass type advected into London, are examined. One particle type, originating from lubricating oil (referred to as Ca-EC), was associated with morning rush hour traffic emissions. A second particle type, composed of both inorganic and organic species (called Na-EC-OC), was found enhanced in particle number concentration during evening time periods, and is likely to originate from a source operating at this time of day, or more probably from condensation of semi-volatile species. A third class, internally mixed with organic carbon and sulphate (called OC), was found to spike both in the morning and evenings although it could not unambiguously associated with a specific source or atmospheric process. The fourth class (Secondary Organic Aerosols - Polycyclic Aromatic Hydrocarbon; SOA-PAH) exhibited maximum frequency during the warmest part of the day, and a number of factors point towards secondary aerosol production from traffic-related volatile aromatic compounds. Single particle mass spectra of this particle type showed an oxidized polycyclic aromatic compound signature. A comparison of ATOFMS particle class data is then made with factors obtained by Positive Matrix Factorization and PAH signatures obtained from Aerosol Mass Spectrometer (AMS) data (Allan et al., 2010). Both the Ca-EC and OC particle types correlate with primary Hydrocarbon-like Organic Aerosol (HOA, R2 = 0.65 and 0.50 respectively), and Na-EC-OC correlates weakly with the AMS
1. Differential aerosolization of algal and cyanobacterial particles in the atmosphere.
PubMed
Sharma, Naveen K; Singh, Surendra
2010-10-01
Aeroalgal sampling at short height (2.5 m) over natural aquatic and terrestrial algal sources revealed that despite of being similar in size (<1 mm), algal groups vary in their atmospheric abundance. Cyanobacteria were the most abundant, while chlorophytes and bacillariophytes though present, but rare. Statistical analysis (Akaike Information Criterion) showed that climatic factors (temperature, relative humidity, rainfall, wind velocity and sunshine hours) acted in concert, and mainly affected the release and subsequent vertical movement (aerosolization) of algae from natural sources. Variation in aerosolization may affect the atmospheric abundance of algae. These findings have important implication as dispersal limitation may influence the biogeography and biodiversity of microbial algae.
2. Retrievals of Aerosol and Cloud Particle Microphysics Using Polarization and Depolarization Techniques
NASA Technical Reports Server (NTRS)
Mishchenko, Michael; Hansen, James E. (Technical Monitor)
2001-01-01
The recent availability of theoretical techniques for computing single and multiple scattering of light by realistic polydispersions of spherical and nonspherical particles and the strong dependence of the Stokes scattering matrix on particle size, shape, and refractive index make polarization and depolarization measurements a powerful particle characterization tool. In this presentation I will describe recent applications of photopolarimetric and lidar depolarization measurements to remote sensing characterization of tropospheric aerosols, polar stratospheric clouds (PSCs), and contrails. The talk will include (1) a short theoretical overview of the effects of particle microphysics on particle single-scattering characteristics; (2) the use of multi-angle multi-spectral photopolarimetry to retrieve the optical thickness, size distribution, refractive index, and number concentration of tropospheric aerosols over the ocean surface; and (3) the application of the T-matrix method to constraining the PSC and contrail particle microphysics using multi-spectral measurements of lidar backscatter and depolarization.
3. Biogenic Potassium Salt Particles as Seeds for Secondary Organic Aerosol in the Amazon
Pöhlker, Christopher; Wiedemann, Kenia T.; Sinha, Bärbel; Shiraiwa, Manabu; Gunthe, Sachin S.; Smith, Mackenzie; Su, Hang; Artaxo, Paulo; Chen, Qi; Cheng, Yafang; Elbert, Wolfgang; Gilles, Mary K.; Kilcoyne, Arthur L. D.; Moffet, Ryan C.; Weigand, Markus; Martin, Scot T.; Pöschl, Ulrich; Andreae, Meinrat O.
2012-08-01
The fine particles serving as cloud condensation nuclei in pristine Amazonian rainforest air consist mostly of secondary organic aerosol. Their origin is enigmatic, however, because new particle formation in the atmosphere is not observed. Here, we show that the growth of organic aerosol particles can be initiated by potassium-salt-rich particles emitted by biota in the rainforest. These particles act as seeds for the condensation of low- or semi-volatile organic compounds from the atmospheric gas phase or multiphase oxidation of isoprene and terpenes. Our findings suggest that the primary emission of biogenic salt particles directly influences the number concentration of cloud condensation nuclei and affects the microphysics of cloud formation and precipitation over the rainforest.
4. Mixing state of particles with secondary species by single particle aerosol mass spectrometer in an atmospheric pollution event
Xu, Lingling; Chen, Jinsheng
2016-04-01
Single particle aerosol mass spectrometer (SPAMS) was used to characterize size distribution, chemical composition, and mixing state of particles in an atmospheric pollution event during 20 Oct. - 5 Nov., 2015 in Xiamen, Southeast China. A total of 533,012 particle mass spectra were obtained and clustered into six groups, comprising of industry metal (4.5%), dust particles (2.6%), carbonaceous species (70.7%), K-Rich particles (20.7%), seasalt (0.6%) and other particles (0.9%). Carbonaceous species were further divided into EC (70.6%), OC (28.5%), and mixed ECOC (0.9%). There were 61.7%, 58.3%, 4.0%, and 14.6% of particles internally mixed with sulfate, nitrate, ammonium and C2H3O, respectively, indicating that these particles had undergone significant aging processing. Sulfate was preferentially mixed with carbonaceous particles, while nitrate tended to mix with metal-containing and dust particles. Compared to clear days, the fractions of EC-, metal- and dust particles remarkably increased, while the fraction of OC-containing particles decreased in pollution days. The mixing state of particles, excepted for OC-containing particles with secondary species was much stronger in pollution days than that in clear days, which revealed the significant influence of secondary particles in atmospheric pollution. The different activity of OC-containing particles might be related to their much smaller aerodynamic diameter. These results could improve our understanding of aerosol characteristics and could be helpful to further investigate the atmospheric process of particles.
5. Impacts of new particle formation on aerosol cloud condensation nuclei (CCN) activity in Shanghai: case study
Leng, C.; Zhang, Q.; Zhang, D.; Zhang, H.; Xu, C.; Li, X.; Kong, L.; Tao, J.; Cheng, T.; Zhang, R.; Chen, J.; Qiao, L.; Lou, S.; Wang, H.; Chen, C.
2014-07-01
New particle formation (NPF) events and their impacts on cloud condensation nuclei (CCN) were investigated using continuous measurements collected in urban Shanghai from 1 to 30 April 2012. During the campaign, NPF occurred in 8 out of the 30 days and enhanced CCN number concentration (NCCN) by a actor of 1.2-1.8, depending on supersaturation (SS). The NPF event on 3 April 2012 was chosen as an example to investigate the NPF influence on CCN activity. In this NPF event, secondary aerosols were produced continuously and increased PM2.5 mass concentration at a~rate of 4.33 μg cm-3 h-1, and the growth rate (GR) and formation rate (FR) were on average 5 nm h-1 and 0.36 cm-3 s-1, respectively. The newly formed particles grew quickly from nucleation mode (10-20 nm) into CCN size range. NCCN increased rapidly at SS of 0.4-1.0% but weakly at SS of 0.2%. Correspondingly, aerosol CCN activities (fractions of activated aerosol particles in total aerosols, NCCN / NCN) were significantly enhanced from 0.24-0.60 to 0.30-0.91 at SS of 0.2-1.0% due to the NPF. On the basis of the κ-Köhler theory, aerosol size distributions and chemical composition measured simultaneously were used to predict NCCN. There was a good agreement between the predicted and measured NCCN (R2 = 0.96, Npredicted / Nmeasured = 1.04). This study reveals that NPF exerts large impacts on aerosol particle abundance and size spectra, thus significantly promotes NCCN and aerosol CCN activity in this urban environment. The GR of NPF is the key factor controlling the newly formed particles to become CCN at all SS levels, whereas the FR is an effective factor only under high SS (e.g. 1.0%) conditions.
6. On the growth of nitric and sulfuric acid aerosol particles under stratospheric conditions
NASA Technical Reports Server (NTRS)
Hamill, Patrick; Turco, R. P.; Toon, O. B.
1988-01-01
A theory for the formation of frozen aerosol particles in the Antarctic stratosphere was developed and applied to the formation of polar stratospheric clouds. The theory suggests that the condensed ice particles are composed primarily of nitric acid and water, with small admixtures of sulfuric and hydrochloric acids in solid solution. The proposed particle formation mechanism is in agreement with the magnitude and seasonal behavior of the optical extinction observed in the winter polar stratosphere.
7. Impacts of oxidation aging on secondary organic aerosol formation, particle growth rate, cloud condensation nuclei abundance, and aerosol climate forcing
Yu, F.; Luo, G.
2014-12-01
Particle composition measurements indicate that organic aerosol (OA) makes up ~20-90% of submicron particulate mass and secondary OA (SOA) accounts for a large fraction (~ 72 ±21%) of these OA masses at many locations around the globe. The volatility changes of secondary organic gases (SOG) associated with oxidation aging as well as the contribution of highly oxidized low volatile SOG (LV-SOG) to the condensational growth of secondary particles have been found to be important in laboratory and field measurements but are poorly represented in global models. A novel scheme to extend the widely used two-product SOA formation model, by adding a third product arising from the oxidation aging (i.e., LV-SOG) and considering the dynamic transfer of mass from higher to lower volatile products, has been developed and implemented into a global chemical transport model (GEOS-Chem) and a community atmosphere model (CESM-CAM5). The scheme requires only minor changes to the existing two-product SOA formation model and is computationally efficient. With the oxidation rate constrained by laboratory measurements, we show that the new scheme predicts a much higher SOA mass concentrations, improving the agreement with aerosol mass spectrometer SOA measurements. The kinetic condensation of LV-SOG on ultrafine particles, simulated by a size-resolved (sectional) advanced particle microphysics (APM) model incorporated into in GEOS-Chem and CAM5, increases the particle growth rate substantially and improves the agreement of simulated cloud condensation nuclei (CCN) concentrations with observations. Based on GEOS-Chem-APM simulations, the new SOA formation scheme increases global mean low troposphere SOA mass concentration by ~130% and CCN abundance by ~ 15%, and optical depth of secondary particles and coated black carbon and primary organic carbon particles by ~10%. As a result, aerosol radiative cooling effect (direct + first indirect) is enhanced by -0.9 W/m2, with large spatial
8. Impeded ice nucleation in glassy and highly viscous aerosol particles: the role of water diffusion
Marcolli, C.; Peter, T.; Zobrist, B.; Krieger, U. K.; Luo, B. P.; Soonsin, V.; Pedernera, D. A.; Koop, T.
2010-05-01
In situ and remote observations in the upper troposphere have disclosed the existence of water vapor pressures up to and even above water saturation. Under such conditions ice particle formation by homogeneous nucleation is expected to set in followed by ice crystal growth until the supersaturation is consumed. While the highest measured water vapor values might not withstand rigorous quality checks, values up to water saturation seem to be occurring. Since air masses appear to contain sufficient numbers of aerosol particles for cloud formation, the question arises why these aerosols are not successful at nucleating ice. The atmospheric aerosol is a complex mixture of various inorganic and organic components, whereas the organic fraction can represent more than 50% of the total aerosol mass. The homogeneous ice nucleation threshold was established for atmospherically relevant salt solutions and sulfuric acid, but only for a few organic species. The organic aerosol fraction tends to remain liquid instead of crystallizing as the temperature is decreased and, thus, organic aerosol particles may form highly viscous liquids. When the viscosity of such liquids reaches values in the order of 1012 Pa s, the molecular motion becomes so slow, that the sample vitrifies at the glass transition temperature Tg. If aerosol particles were present as glasses, this would influence several physical and chemical processes in the atmosphere significantly: Water uptake from the gas phase would be drastically impeded and ice nucleation inhibited. We investigated the glass transition temperature of a series of aqueous organic solutions such as polyols, sugars and dicarboxylic acids as a function of the solute concentration using a differential scanning calorimeter (DSC). These measurements show that the higher the molar mass of the organic solutes, the higher Tg of their respective solutions at a given water activity. Aerosol particles containing larger (≥150 g mol-1) organic molecules
9. Ice cloud processing of ultra-viscous/glassy aerosol particles leads to enhanced ice nucleation ability
Wagner, R.; Möhler, O.; Saathoff, H.; Schnaiter, M.; Skrotzki, J.; Leisner, T.; Wilson, T. W.; Malkin, T. L.; Murray, B. J.
2012-09-01
The ice nucleation potential of airborne glassy aqueous aerosol particles has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 247 and 216 K. Four different solutes were used as proxies for oxygenated organic matter found in the atmosphere: raffinose, 4-hydroxy-3-methoxy-DL-mandelic acid (HMMA), levoglucosan, and a multi-component mixture of raffinose with five dicarboxylic acids and ammonium sulphate. Similar to previous experiments with citric acid aerosols, all particles were found to nucleate ice heterogeneously before reaching the homogeneous freezing threshold provided that the freezing cycles were started well below the respective glass transition temperatures of the compounds; this is discussed in detail in a separate article. In this contribution, we identify a further mechanism by which glassy aerosols can promote ice nucleation below the homogeneous freezing limit. If the glassy aerosol particles are probed in freezing cycles started only a few degrees below their respective glass transition temperatures, they enter the liquid regime of the state diagram upon increasing relative humidity (moisture-induced glass-to-liquid transition) before being able to act as heterogeneous ice nuclei. Ice formation then only occurs by homogeneous freezing at elevated supersaturation levels. When ice forms the remaining solution freeze concentrates and re-vitrifies. If these ice cloud processed glassy aerosol particles are then probed in a second freezing cycle at the same temperature, they catalyse ice formation at a supersaturation threshold between 5 and 30% with respect to ice. By analogy with the enhanced ice nucleation ability of insoluble ice nuclei like mineral dusts after they nucleate ice once, we refer to this phenomenon as pre-activation. We propose a number of possible explanations for why glassy aerosol particles that have re-vitrified in contact
10. Reduced anthropogenic aerosol radiative forcing caused by biogenic new particle formation
Gordon, Hamish; Sengupta, Kamalika; Rap, Alexandru; Duplissy, Jonathan; Frege, Carla; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K.; Wagner, Robert; Dunne, Eimear M.; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill S.; Dias, Antonio; Ehrhart, Sebastian; Fischer, Lukas; Flagan, Richard C.; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R.; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Monks, Sarah A.; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P.; Pringle, Kirsty J.; Richards, Nigel A. D.; Rissanen, Matti P.; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E.; Seinfeld, John H.; Sharma, Sangeeta; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander Lucas; Wagner, Andrea C.; Wagner, Paul E.; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M.; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M.; Worsnop, Douglas R.; Baltensperger, Urs; Kulmala, Markku; Curtius, Joachim; Carslaw, Kenneth S.
2016-10-01
The magnitude of aerosol radiative forcing caused by anthropogenic emissions depends on the baseline state of the atmosphere under pristine preindustrial conditions. Measurements show that particle formation in atmospheric conditions can occur solely from biogenic vapors. Here, we evaluate the potential effect of this source of particles on preindustrial cloud condensation nuclei (CCN) concentrations and aerosol-cloud radiative forcing over the industrial period. Model simulations show that the pure biogenic particle formation mechanism has a much larger relative effect on CCN concentrations in the preindustrial atmosphere than in the present atmosphere because of the lower aerosol concentrations. Consequently, preindustrial cloud albedo is increased more than under present day conditions, and therefore the cooling forcing of anthropogenic aerosols is reduced. The mechanism increases CCN concentrations by 20-100% over a large fraction of the preindustrial lower atmosphere, and the magnitude of annual global mean radiative forcing caused by changes of cloud albedo since 1750 is reduced by 0.22 W m-2 (27%) to -0.60 W m-2. Model uncertainties, relatively slow formation rates, and limited available ambient measurements make it difficult to establish the significance of a mechanism that has its dominant effect under preindustrial conditions. Our simulations predict more particle formation in the Amazon than is observed. However, the first observation of pure organic nucleation has now been reported for the free troposphere. Given the potentially significant effect on anthropogenic forcing, effort should be made to better understand such naturally driven aerosol processes.
11. Reduced anthropogenic aerosol radiative forcing caused by biogenic new particle formation.
PubMed
Gordon, Hamish; Sengupta, Kamalika; Rap, Alexandru; Duplissy, Jonathan; Frege, Carla; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K; Wagner, Robert; Dunne, Eimear M; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill S; Dias, Antonio; Ehrhart, Sebastian; Fischer, Lukas; Flagan, Richard C; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Monks, Sarah A; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P; Pringle, Kirsty J; Richards, Nigel A D; Rissanen, Matti P; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E; Seinfeld, John H; Sharma, Sangeeta; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander Lucas; Wagner, Andrea C; Wagner, Paul E; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M; Worsnop, Douglas R; Baltensperger, Urs; Kulmala, Markku; Curtius, Joachim; Carslaw, Kenneth S
2016-10-25
The magnitude of aerosol radiative forcing caused by anthropogenic emissions depends on the baseline state of the atmosphere under pristine preindustrial conditions. Measurements show that particle formation in atmospheric conditions can occur solely from biogenic vapors. Here, we evaluate the potential effect of this source of particles on preindustrial cloud condensation nuclei (CCN) concentrations and aerosol-cloud radiative forcing over the industrial period. Model simulations show that the pure biogenic particle formation mechanism has a much larger relative effect on CCN concentrations in the preindustrial atmosphere than in the present atmosphere because of the lower aerosol concentrations. Consequently, preindustrial cloud albedo is increased more than under present day conditions, and therefore the cooling forcing of anthropogenic aerosols is reduced. The mechanism increases CCN concentrations by 20-100% over a large fraction of the preindustrial lower atmosphere, and the magnitude of annual global mean radiative forcing caused by changes of cloud albedo since 1750 is reduced by [Formula: see text] (27%) to [Formula: see text] Model uncertainties, relatively slow formation rates, and limited available ambient measurements make it difficult to establish the significance of a mechanism that has its dominant effect under preindustrial conditions. Our simulations predict more particle formation in the Amazon than is observed. However, the first observation of pure organic nucleation has now been reported for the free troposphere. Given the potentially significant effect on anthropogenic forcing, effort should be made to better understand such naturally driven aerosol processes.
12. Collection efficiency of α-pinene secondary organic aerosol particles explored via light-scattering single-particle aerosol mass spectrometry
Shipley Robinson, Ellis; Onasch, Timothy B.; Worsnop, Douglas; Donahue, Neil M.
2017-03-01
We investigated the collection efficiency and effective ionization efficiency for secondary organic aerosol (SOA) particles made from α-pinene + O3 using the single-particle capabilities of the aerosol mass spectrometer (AMS). The mean count-based collection efficiency (CEp) for SOA across these experiments is 0.30 (±0.04 SD), ranging from 0.25 to 0.40. The mean mass-based collection efficiency (CEm) is 0.49 (±0.07 SD). This sub-unit collection efficiency and delayed vaporization is attributable to particle bounce in the vaporization region. Using the coupled optical and chemical detection of the light-scattering single-particle (LSSP) module of the AMS, we provide clear evidence that delayed vaporization is somewhat of a misnomer for these particles: SOA particles measured as a part of the AMS mass distribution do not vaporize at a slow rate; rather, they flash-vaporize, albeit often not on the initial impact with the vaporizer but instead upon a subsequent impact with a hot surface in the vaporization region. We also find that the effective ionization efficiency (defined as ions per particle, IPP) decreases with delayed arrival time. CEp is not a function of particle size (for the mobility diameter range investigated, 170-460 nm), but we did see a decrease in CEp with thermodenuder temperature, implying that oxidation state and/or volatility can affect CEp for SOA. By measuring the mean ions per particle produced for monodisperse particles as a function of signal delay time, we can separately determine CEp and CEm and thus more accurately measure the relative ionization efficiency (compared to ammonium nitrate) of different particle types.
13. Measurements of aerosol chemistry during new particle formation events at a remote rural mountain site.
PubMed
Creamean, Jessie M; Ault, Andrew P; Ten Hoeve, John E; Jacobson, Mark Z; Roberts, Gregory C; Prather, Kimberly A
2011-10-01
Determining the major sources of particles that act as cloud condensation nuclei (CCN) represents a critical step in the development of a more fundamental understanding of aerosol impacts on cloud formation and climate. Reported herein are direct measurements of the CCN activity of newly formed ambient particles, measured at a remote rural site in the Sierra Nevada Mountains of Northern California. Nucleation events in the winter of 2009 occurred during two pristine periods following precipitation, with higher gas-phase SO(2) concentrations during the second period, when faster particle growth occurred (7-8 nm/h). Amines, as opposed to ammonia, and sulfate were detected in the particle phase throughout new particle formation (NPF) events, increasing in number as the particles grew to larger sizes. Interestingly, long-range transport of SO(2) from Asia appeared to potentially play a role in NPF during faster particle growth. Understanding the propensity of newly formed particles to act as CCN is critical for predicting the effects of NPF on orographic cloud formation during winter storms along the Sierra Nevada Mountain range. The potential impact of newly formed particles in remote regions needs to be compared with that of transported urban aerosols when evaluating the impact of aerosols on clouds and climate.
14. Aerosol and Cloud-Nucleating Particle Observations during an Atmospheric River Event
DeMott, P. J.; McCluskey, C. S.; Petters, M.; Suski, K. J.; Levin, E. J.; Hill, T. C. J.; Atwood, S. A.; Schill, G. P.; Rocci, K.; Boose, Y.; Martin, A.; Cornwell, G.; Al-Mashat, H.; Moore, K.; Prather, K. A.; Rothfuss, N.; Taylor, H.; Leung, L. R.; Tomlinson, J. M.; Mei, F.; Hubbe, J. M.; Rosenfeld, D.; Spackman, J. R.; Fairall, C. W.; Creamean, J.; White, A. B.; Kreidenweis, S. M.
2015-12-01
The multi-agency CalWater 2015 project occurred over North Central CA and the Eastern Pacific during January to March 2015 (Spackman et al., this session). The goals of the campaign were to document the structure of atmospheric rivers (ARs) that deliver much of the water vapor associated with major winter storms along the U.S. West Coast and to investigate the modulating effect of aerosols on precipitation. Aerosol sources that may influence orographic cloud properties for air lifted over the mountains in California in winter include pollution, biomass burning, soil dusts and marine aerosols, but their roles will also be influenced by transport, vertical stratification, and scavenging processes. We present results from a comprehensive study of aerosol distributions, compositions, and cloud nucleating properties during an intense winter storm during February 2015, including data from an NSF-supported measurement site at Bodega Bay, from the DOE-ARM Cloud Aerosol Precipitation Experiment that included sampling on the NOAA RV Ron Brown offshore and the G-1 aircraft over ocean and land, and with context provided by other NOAA aircraft and remote sensing facilities. With a special focus on the coastal site, we discuss changes in aerosol distributions, aerosol hygroscopicity, and number concentrations of fluorescent particles, cloud condensation nuclei (CCN), and ice nucleating particles (INPs) during the AR event. We compare with periods preceding and following the event. For example, total aerosol number and surface area concentrations at below 0.5 μm diameter decreased from typical values of a few thousand cm-3 and 100 μm2 cm-3, respectively, to a few hundred cm-3 and 10 μm2cm-3 at Bodega Bay during the AR event. CCN concentrations were similarly lower, but hygroscopicity parameter (kappa) increased from typical values of 0.2 to values > 0.5 during the AR.INP and fluorescent particle number concentrations were generally lower during the AR event than at any other
15. Numerical investigation of the coagulation mixing between dust and hygroscopic aerosol particles and its impacts
Tsai, I.-Chun; Chen, Jen-Ping; Lin, Yi-Chiu; Chung-Kuang Chou, Charles; Chen, Wei-Nai
2015-05-01
A statistical-numerical aerosol parameterization was incorporated into the Community Multiscale Air Quality modeling system to study the coagulation mixing process focusing on a dust storm event that occurred over East Asia. Simulation results show that the coagulation mixing process tends to decrease aerosol mass, surface area, and number concentrations over the dust source areas. Over the downwind oceanic areas, aerosol concentrations generally increased due to enhanced sedimentation as particles became larger upon coagulation. The mixture process can reduce the overall single-scattering albedo by up to 10% as a result of enhanced core with shell absorption by dust and reduction in the number of scattering particles. The enhanced dry deposition speed also altered the vertical distribution. In addition, the ability of aerosol particles to serve as cloud condensation nuclei (CCN) increased from around 107 m-3 to above 109 m-3 over downwind areas because a large amount of mineral dust particles became effective CCN with solute coating, except over the highly polluted areas where multiple collections of hygroscopic particles by dust in effect reduced CCN number. This CCN effect is much stronger for coagulation mixing than by the uptake of sulfuric acid gas on dust, although the nitric acid gas uptake was not investigated. The ability of dust particles to serve as ice nuclei may decrease or increase at low or high subzero temperatures, respectively, due to the switching from deposition nucleation to immersion freezing or haze freezing.
16. The on-line detection of biological particle emissions from selected agricultural materials using the WIBS-4 (Waveband Integrated Bioaerosol Sensor) technique
O'Connor, David J.; Healy, David A.; Sodeau, John R.
2013-12-01
Agricultural activities have, for some time, been linked to adverse health effects such as Farmers' lung, hypersensitivity pneumonitis, aspergillosis and chronic obstructive pulmonary disease (COPD) This connection is known to be, at least in part, due to the numerous microbiological organisms that live and grow on materials found in occupational settings such as barns, animal shelters, stables and composting sites. Traditional techniques for determining biological release of fungal spores and bacteria require intensive, experienced human resources and considerable time to determine ambient concentrations. However more recently the fluorescence and light scattering signals obtained from primary biological aerosol particles (PBAP) have been utilised for their near real-time counting and characterisation abilities. In the current study, data collected for the bioaerosol types released from hay and silage were counted and identified using a combination of the WIBS-4 bioaerosol sensor approach and impaction/optical microscopy. Particle emissions were characterised according to particle numbers, their size distributions, particle asymmetry values and fluorescence characteristics. The variables obtained were shown to provide potential “fingerprint” signatures for PBAP emissions emanating from two important compost components, namely, silage and hay. Comparisons between the data acquired by the WIBS-4 bioaerosol sensor, optical microscopy findings and also previous literature suggest that the likely identification of Aspergillus/Penicillium type spores and bacterial species released from hay and silage was achieved on a relatively rapid time-scale.
17. Individual Aerosol Particles from Biomass Burning in Southern Africa. 1; Compositions and Size Distributions of Carbonaceous Particles
NASA Technical Reports Server (NTRS)
Posfai, Mihaly; Simonics, Renata; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.
2003-01-01
Individual aerosol particles in smoke plumes from biomass fires and in regional hazes in southern Africa were studied using analytical transmission electron microscopy (TEM), which allowed detailed characterization of carbonaceous particle types in smoke and determination of changes in particle properties and concentrations during smoke aging. Based on composition, morphology, and microstructure, three distinct types of carbonaceous particles were present in the smoke: organic particles with inorganic (K-salt) inclusions, tar ball particles, and soot. The relative number concentrations of organic particles were largest in young smoke, whereas tar balls were dominant in a slightly aged (1 hour) smoke from a smoldering fire. Flaming fires emitted relatively more soot particles than smoldering fires, but soot was a minor constituent of all studied plumes. Further aging caused the accumulation of sulfate on organic and soot particles, as indicated by the large number of internally mixed organic/sulfate and soot/sulfate particles in the regional haze. Externally mixed ammonium sulfate particles dominated in the boundary layer hazes, whereas organic/sulfate particles were the most abundant type in the upper hazes. Apparently, elevated haze layers were more strongly affected by biomass smoke than those within the boundary layer. Based on size distributions and the observed patterns of internal mixing, we hypothesize that organic and soot particles are the cloud-nucleating constituents of biomass smoke aerosols. Sea-salt particles dominated in the samples taken in stratus clouds over the Atlantic Ocean, off the coast of Namibia, whereas a distinct haze layer above the clouds consisted of aged biomass smoke particles.
18. Individual aerosol particles from biomass burning in southern Africa: 1. Compositions and size distributions of carbonaceous particles
Pósfai, MiháLy; Simonics, RenáTa; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.
2003-07-01
Individual aerosol particles in smoke plumes from biomass fires and in regional hazes in southern Africa were studied using analytical transmission electron microscopy (TEM), which allowed detailed characterization of carbonaceous particle types in smoke and determination of changes in particle properties and concentrations during smoke aging. Based on composition, morphology, and microstructure, three distinct types of carbonaceous particles were present in the smoke: organic particles with inorganic (K-salt) inclusions, "tar ball" particles, and soot. The relative number concentrations of organic particles were largest in young smoke, whereas tar balls were dominant in a slightly aged (˜1 hour) smoke from a smoldering fire. Flaming fires emitted relatively more soot particles than smoldering fires, but soot was a minor constituent of all studied plumes. Further aging caused the accumulation of sulfate on organic and soot particles, as indicated by the large number of internally mixed organic/sulfate and soot/sulfate particles in the regional haze. Externally mixed ammonium sulfate particles dominated in the boundary layer hazes, whereas organic/sulfate particles were the most abundant type in the upper hazes. Apparently, elevated haze layers were more strongly affected by biomass smoke than those within the boundary layer. Based on size distributions and the observed patterns of internal mixing, we hypothesize that organic and soot particles are the cloud-nucleating constituents of biomass smoke aerosols. Sea-salt particles dominated in the samples taken in stratus clouds over the Atlantic Ocean, off the coast of Namibia, whereas a distinct haze layer above the clouds consisted of aged biomass smoke particles.
19. Modelling non-equilibrium secondary organic aerosol formation and evaporation with the aerosol dynamics, gas- and particle-phase chemistry kinetic multilayer model ADCHAM
SciTech Connect
Roldin, P.; Eriksson, A. C.; Nordin, E. Z.; Hermansson, E.; Mogensen, Ditte; Rusanen, A.; Boy, Michael; Swietlicki, E.; Svenningsson, Birgitta; Zelenyuk, Alla; Pagels, J.
2014-08-11
We have developed the novel Aerosol Dynamics, gas- and particle- phase chemistry model for laboratory CHAMber studies (ADCHAM). The model combines the detailed gas phase Master Chemical Mechanism version 3.2, an aerosol dynamics and particle phase chemistry module (which considers acid catalysed oligomerization, heterogeneous oxidation reactions in the particle phase and non-ideal interactions between organic compounds, water and inorganic ions) and a kinetic multilayer module for diffusion limited transport of compounds between the gas phase, particle surface and particle bulk phase. In this article we describe and use ADCHAM to study: 1) the mass transfer limited uptake of ammonia (NH3) and formation of organic salts between ammonium (NH4+) and carboxylic acids (RCOOH), 2) the slow and almost particle size independent evaporation of α-pinene secondary organic aerosol (SOA) particles, and 3) the influence of chamber wall effects on the observed SOA formation in smog chambers.
20. Ice cloud processing of ultra-viscous/glassy aerosol particles leads to enhanced ice nucleation ability
Wagner, R.; Möhler, O.; Saathoff, H.; Schnaiter, M.; Skrotzki, J.; Leisner, T.; Wilson, T. W.; Malkin, T. L.; Murray, B. J.
2012-04-01
The ice nucleation potential of airborne glassy aqueous aerosol particles has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 247 and 216 K. Four different solutes were used as proxies for oxygenated organic matter found in the atmosphere: raffinose, 4-hydroxy-3-methoxy-DL-mandelic acid (HMMA), levoglucosan, and a multi-component mixture of raffinose with five dicarboxylic acids and ammonium sulphate. Similar to previous experiments with citric acid aerosols, all particles were found to nucleate ice heterogeneously before reaching the homogeneous freezing threshold provided that the freezing cycles were started well below the respective glass transition temperatures of the compounds; this is discussed in detail in a separate article. In this contribution, we identify a further mechanism by which glassy aerosols can promote ice nucleation below the homogeneous freezing limit. If the glassy aerosol particles are probed in freezing cycles started only a few degrees below their respective glass transition temperatures, they enter the liquid regime of the state diagram upon increasing relative humidity (moisture-induced glass-to-liquid transition) before being able to act as heterogeneous ice nuclei. Ice formation then only occurs by homogeneous freezing at elevated supersaturation levels. When ice forms the remaining solution freeze concentrates and re-vitrifies. If these ice cloud processed glassy aerosol particles are then probed in a second freezing cycle at the same temperature, they catalyse ice formation at a supersaturation threshold between 5 and 30% with respect to ice. By analogy with the enhanced ice nucleation ability of insoluble ice nuclei like mineral dusts after they nucleate ice once, we refer to this phenomenon as pre-activation. We propose a number of possible explanations for why glassy aerosols that have re-vitrified in contact with the
1. The weather dependence of particle size distribution of indoor radioactive aerosol associated with radon decay products.
PubMed
Mostafa, A M A; Tamaki, K; Moriizumi, J; Yamazawa, H; Iida, T
2011-07-01
This study was performed to measure the activity size distribution of aerosol particles associated with short-lived radon decay products in indoor air at Nagoya University, Nagoya, Japan. The measurements were performed using a low pressure Andersen cascade impactor under variable meteorological conditions. The results showed that the greatest activity fraction was associated with aerosol particles in the accumulation size range (100-1000 nm) with a small fraction of nucleation mode (10-100 nm). Regarding the influence of the weather conditions, the decrease in the number of accumulation particles was observed clearly after rainfall without significant change in nucleation particles, which may be due to a washout process for the large particles.
2. [Comparative studies of particle distribution range of aerosol cromolyn sodium generated by MDI systems].
PubMed
1999-05-01
Particles size distribution of the sodium cromoglycate preparations: CROPOZ PLUS and CROMOGEN EB generated with MDI and for under-pressure releasing methods were measured. Results of measurements indicate a significant repeatability of each sample properties. An average contribution of mass of the respirable fraction for both aerosolized pharmaceuticals is in the range of 40% of the generated dose. CROMOGEN EB with optimizer (spacer) gives a higher contribution of the respirable fraction--up to 50% of dose, with simultaneous lower value of the released mass of aerosol. Particles size distribution of CROPOZ PLUS within a respirable fraction indicates an efficient penetration and deposition of particles in the upper, central and peripheral parts of tracheobronchial tree (TB). High contribution of submicron particles of CROMOGEN EB with optimizer gives efficient penetration and deposition of these particles in the lungs.
3. Fabrication of a pure, uniform electroless silver film using ultrafine silver aerosol particles.
PubMed
Byeon, Jeong Hoon; Kim, Jang-Woo
2010-07-20
To obtain evenly distributed pure Ag particles with a narrow size distribution on a polymer membrane, a novel activation procedure with an environmentally friendly, cost-effective method was utilized as a pretreatment before electroless Ag deposition. The pretreatment was first performed on an untreated membrane surface by collecting ultrafine ambient spark-generated Ag aerosol particles. After annealing, the electroless Ag film was fabricated on the collected aerosol particles in the Ag electroless bath. Experimental characterizations showed that the ultrafine Ag particles were uniformly anchored onto the membrane surface through pretreatment, resulting in a pure Ag film of closely packed particles with a narrow size distribution on the membrane, and the properties were comparable to those of an Ag film on wet Sn-Ag-activated membranes.
4. Mass Spectrometry of Liquid Aniline Aerosol Particles by IR/UV Laser Irradiation.
PubMed
Zelenyuk, A; Cabalo, J; Baer, T; Miller, R E
1999-05-01
The first results are reported from a new single-particle two-color laser time-of-flight mass spectrometer, incorporating a combination of infrared (CO(2)) and UV (excimer) laser irradiation. This combination of lasers has the capability to effectively separate the desorption or evaporation step from the ionization step, thereby greatly improving the analytical capabilities of such an instrument. The results on liquid aerosols, such as aniline, show that prior evaporation of the aerosol particle with the IR laser increases the ion signal produced by the excimer laser by more than 2 orders of magnitude. In the case of nitrobenzene aerosols, the excimer laser alone produces no ions, while a very large signal is observed when the aerosol is first irradiated with the CO(2) laser. A simple model, based on the Coulomb explosion of the ionized aerosol, is used to estimate the number of ions generated by the excimer laser (∼10(5) ions). Experimental evidence based on the observed time delay of protonated aniline parent ions indicates that the laser irradiation of the liquid aerosol results in a stable neutral plasma which separates into positive and negative charges only after a 100-500-ns delay.
5. Comparison of POLDER Derived Aerosol Optical Thickness to Surface Monitor Fine Particle Concentration
Leon, J.; Kacenelenbogen, M.; Chiapello, I.
2005-12-01
The Particulate Matter (PM) mass measured at the ground level is a common way to quantify the amount of aerosol particles in the atmosphere and is used as a standard to evaluate air quality. Satellite remote sensing is well suited for a daily monitoring of the aerosol load. However, there are no straightforward relationship between aerosol optical properties derived from the satellite sensor and the PM mass at the ground. This paper is focused on the use of Polarization and Directionality of Earth's Reflectance (POLDER-2) derived aerosol optical thickness (AOT) for the monitoring of PM2.5. We present a correlation study between PM2.5 data collected in the frame of the French Environmental protection agency, aerosol optical properties derived from Sun photometer measurements, and POLDER derived-AOT over the land. POLDER AOT retrieval algorithm over the land is based on the use of the measurement of the linear polarized light in the 670 nm and 865 nm channels. We show that only the fine fraction (below 0.3 μm) of the aerosol size distribution contributes to the signal in polarization and then to the POLDER derived-AOT and then is well suited for monitoring of fine particle. The correlation between POLDER AOT and PM2.5 is significant (R between 0.6 and 0.7) over several sites. We present a tentative evaluation of Air Quality Categories from satellite data.
6. Aerosols
Atmospheric Science Data Center
2013-04-17
... article title: Aerosols over Central and Eastern Europe View Larger Image ... last weeks of March 2003, widespread aerosol pollution over Europe was detected by several satellite-borne instruments. The Multi-angle ...
7. Atmospheric Black Carbon: Chemical Bonding and Structural Information of Individual Aerosol Particles
Gilles, M. K.; Tivanski, A. V.; Hopkins, R. J.; Marten, B. D.
2006-12-01
The formation of aerosols from both natural and anthropogenic sources affects the Earth's temperature and climate by altering the radiative properties of the atmosphere. Aerosols containing black carbon (BC) that are released into the atmosphere from the burning of biomass, natural fires and the combustion of coals, diesel and jet fuels, contribute a large positive component to this radiative forcing, thus causing a heating of the atmosphere. A distinct type of biomass burn aerosol referred to as "tar balls" has recently been reported in the literature and is characterized by a spherical morphology, high carbon content and ability to efficiently scatter and absorb light. At present, very little is known about the exact nature and variation of the range of BC aerosols in the atmosphere with regards to optical, chemical and physical properties. Additionally, the similarity of these aerosols to surrogates used in the laboratory as atmospheric mimics remains unclear. The local chemical bonding, structural ordering and carbon-to-oxygen ratios of a plethora of black carbon standard reference materials (BC SRMs), high molecular mass humic-like substances (HULIS) and atmospheric aerosols from a variety of sources are examined using scanning transmission X-ray microscopy (STXM) coupled with near edge X-ray absorption fine structure (NEXAFS) spectroscopy. STXM/NEXAFS enables single aerosol particles of diameter upwards of 100 nm to be studied, which allows the diversity of atmospheric aerosol collected during a variety of field missions to be assessed. We apply a semi-quantitative peak fitting method to the recorded NEXAFS spectral fingerprints allowing comparison of BC SRMs and HULIS to BC aerosol originating from anthropogenic combustion and biomass burning events. This method allows us to distinguish between anthropogenic combustion and biomass burn aerosol using both chemical bonding and structural ordering information. The STXM/NEXAFS technique has also been utilized to
8. Characterizing the impact of urban emissions on regional aerosol particles; airborne measurements during the MEGAPOLI experiment
Freney, E. J.; Sellegri, K.; Canonaco, F.; Colomb, A.; Borbon, A.; Michoud, V.; Doussin, J.-F.; Crumeyrolle, S.; Amarouch, N.; Pichon, J.-M.; Prévôt, A. S. H.; Beekmann, M.; Schwarzenböeck, A.
2013-09-01
The MEGAPOLI experiment took place in July 2009. The aim of this campaign was to study the aging and reactions of aerosol and gas-phase emissions in the city of Paris. Three ground-based measurement sites and several mobile platforms including instrument equipped vehicles and the ATR-42 aircraft were involved. We present here the variations in particle- and gas-phase species over the city of Paris using a combination of high-time resolution measurements aboard the ATR-42 aircraft. Particle chemical composition was measured using a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS) giving detailed information of the non-refractory submicron aerosol species. The mass concentration of BC, measured by a particle absorption soot photometer (PSAP), was used as a marker to identify the urban pollution plume boundaries. Aerosol mass concentrations and composition were affected by air-mass history, with air masses that spent longest time over land having highest fractions of organic aerosol and higher total mass concentrations. The Paris plume is mainly composed of organic aerosol (OA), black carbon and nitrate aerosol, as well as high concentrations of anthropogenic gas-phase species such as toluene, benzene, and NOx. Using BC and CO as tracers for air-mass dilution, we observe the ratio of ΔOA / ΔBC and ΔOA / ΔCO increase with increasing photochemical age (-log(NOx / NOy). Plotting the equivalent ratios for the Positive Matrix Factorization (PMF) resolved species (LV-OOA, SV-OOA, and HOA) illustrate that the increase in OA is a result of secondary organic aerosol (SOA). Within Paris the changes in the ΔOA / ΔCO are similar to those observed during other studies in Mexico city, Mexico and in New England, USA. Using the measured VOCs species together with recent organic aerosol formation yields we predicted ~ 50% of the measured organics. These airborne measurements during the MEGAPOLI experiment show that urban emissions contribute to the formation of OA
9. Characterizing the impact of urban emissions on regional aerosol particles: airborne measurements during the MEGAPOLI experiment
Freney, E. J.; Sellegri, K.; Canonaco, F.; Colomb, A.; Borbon, A.; Michoud, V.; Doussin, J.-F.; Crumeyrolle, S.; Amarouche, N.; Pichon, J.-M.; Bourianne, T.; Gomes, L.; Prevot, A. S. H.; Beekmann, M.; Schwarzenböeck, A.
2014-02-01
The MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) experiment took place in July 2009. The aim of this campaign was to study the aging and reactions of aerosol and gas-phase emissions in the city of Paris. Three ground-based measurement sites and several mobile platforms including instrument equipped vehicles and the ATR-42 aircraft were involved. We present here the variations in particle- and gas-phase species over the city of Paris, using a combination of high-time resolution measurements aboard the ATR-42 aircraft. Particle chemical composition was measured using a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS), giving detailed information on the non-refractory submicron aerosol species. The mass concentration of black carbon (BC), measured by a particle absorption soot photometer (PSAP), was used as a marker to identify the urban pollution plume boundaries. Aerosol mass concentrations and composition were affected by air-mass history, with air masses that spent longest time over land having highest fractions of organic aerosol and higher total mass concentrations. The Paris plume is mainly composed of organic aerosol (OA), BC, and nitrate aerosol, as well as high concentrations of anthropogenic gas-phase species such as toluene, benzene, and NOx. Using BC and CO as tracers for air-mass dilution, we observe the ratio of ΔOA / ΔBC and ΔOA / ΔCO increase with increasing photochemical age (-log(NOx / NOy)). Plotting the equivalent ratios of different organic aerosol species (LV-OOA, SV-OOA, and HOA) illustrate that the increase in OA is a result of secondary organic aerosol (SOA) formation. Within Paris the changes in the ΔOA / ΔCO are similar to those observed during other studies in London, Mexico City, and in New England, USA. Using the measured SOA volatile organic compounds (VOCs) species together with organic aerosol formation
10. Polarization properties of aerosol particles over western Japan: classification, seasonal variation, and implications for air quality
Pan, Xiaole; Uno, Itsushi; Hara, Yukari; Osada, Kazuo; Yamamoto, Shigekazu; Wang, Zhe; Sugimoto, Nobuo; Kobayashi, Hiroshi; Wang, Zifa
2016-08-01
Ground-based observation of the polarization properties of aerosol particles using a polarization optical particle counter (POPC) was made from 27 October 2013, to 31 December 2015, at a suburban site in the Kyushu area of Japan. We found that the depolarization ratio (DR, the fraction of s-polarized signal in the total backward light scattering signal) of aerosol particles showed prominent seasonal variability, with peaks in spring (0.21-0.23) and winter (0.19-0.23), and a minimum value (0.09-0.14) in summer. The aerosol compositions in both fine mode (aerodynamic diameter of particle, Dp < 2.5 µm) and coarse mode (2.5 µm < Dp < 10 µm), and the size-dependent polarization characteristics were analyzed for long-range transport dust particles, sea salt, and anthropogenic pollution-dominant aerosols. The DR value increased with increasing particle size, and DR = 0.1 was a reliable threshold value to identify the sphericity of supermicron (Dp > 1 µm) particles. Occurrence of substandard air quality days in Kyushu was closely related with mixed type (coexistence of anthropogenic pollutants and dust particles in the atmosphere), especially in winter and spring, indicating that dust events in the Asian continent played a key role in the cross-boundary transport of continental pollution. Backward trajectory analysis demonstrated that air masses originating from the western Pacific contained large amounts of spherical particles due to the influence of sea salt, especially in summer; however, for air masses from the Asian continent, the dependence of number fraction of spherical particles on air relative humidity was insignificant, indicating the predominance of less-hygroscopic substances (e.g., mineral dust), although the mass concentrations of anthropogenic pollutants were elevated.
11. Effect of particle settling on lidar profiles of long-range transported Saharan aerosols
Gasteiger, Josef; Groß, Silke
2016-04-01
A large amount of desert aerosol is transported in the Saharan Air Layer (SAL) westwards from Africa over the Atlantic Ocean. Lidar profiles of transported Saharan aerosol may contain some information about the vertically-resolved aerosol microphysics that could be used to characterize processes that affected the measured aerosol during transport. We present modelled lidar profiles of long-range transported Saharan aerosol assuming that initially the SAL is well-mixed and that there is no vertical mixing of air within the SAL as soon as it reaches the Atlantic. We consider Stokes gravitational settling of aerosol particles over the ocean. The lidar profiles are calculated using optical models for irregularly-shaped mineral dust particles assuming settling-induced particle removal as function of distance from the SAL top. Within the SAL we find a decrease of both the backscatter coefficients and the linear depolarization ratios with decreasing distance from the SAL top. For example, the linear depolarization ratio at a wavelength of 532nm decreases from 0.289 at 1000m to 0.256 at 200m and 0.215 at 100m below SAL top. We compare the modelled backscatter coefficients and linear depolarization ratios to ground-based lidar measurements performed during the SALTRACE field campaign in Barbados (Caribbean) and find agreement within the estimated uncertainties. We discuss the uncertainties of our modeling approach in our presentation. Assumed mineral dust particle shapes, assumed particle mixture properties, and assumptions about processes in the SAL over the continent and the ocean are important aspects to be considered. Uncertainties are relevant for the potential of lidar measurements of transported Saharan dust to learn something about processes occuring in the SAL during long-range transport. We also compare our modeling results to modeling results previously published in the literature.
12. Hygroscopic Measurements of Aerosol Particles in Colorado during the Discover AQ Campaign 2014
Orozco, D.; Delgado, R.; Espinosa, R.; Martins, J. V.; Hoff, R. M.
2014-12-01
In ambient conditions, aerosol particles experience hygroscopic growth due to the influence of relative humidity (RH), scattering more light than when the particles are dry. The quantitative knowledge of the RH effect and its influence on the light scattering and, in particular, on the phase function and polarization of aerosol particles is of substantial importance when comparing ground observations with other optical aerosol measurements such satellite and sunphotometric retrievals of aerosol optical depth and their inversions. In the summer of 2014, the DISCOVER-AQ campaign was held in Colorado, where systematic and concurrent observations of column- integrated surface, and vertically-resolved distributions of aerosols and trace gases relevant to air quality and their evolution during the day were observed. Aerosol optical properties were measured in the UMBC trailer at the city of Golden using a TSI-3563 nephelometer and an in-situ Polarized Imaging Nephelometer (PI-NEPH) designed and built by the LACO group at UMBC. The PI-NEPH measures aerosol phase matrix components in high angular range between 2 and 178 degrees scattering angle at three wavelengths (λ=473, 532 and 671nm). The two measured elements of the phase matrix, intensity (P11) and linear polarization (P12) provide extensive characterization of the scattering properties of the studied aerosol. The scattering coefficient, P11 and P12 were measured under different humidity conditions to obtain the enhancement factor f(RH) and the dependence of P11 and P12 to RH using a humidifier dryer system covering a RH range from 20 to 90%. The ratio between scattering coefficients at high and low humidity in Golden Colorado showed relatively low hygroscopic growth in the aerosol particles f(RH=80%) was 1.27±0.19 for the first three weeks of sampling. According to speciated measurements performed at the UMBC trailer, the predominance of dust and organic aerosols over more hygroscopic nitrate and sulfate in the
13. Ultrasensitive detection of inhaled organic aerosol particles by accelerator mass spectrometry.
PubMed
Parkhomchuk, E V; Gulevich, D G; Taratayko, A I; Baklanov, A M; Selivanova, A V; Trubitsyna, T A; Voronova, I V; Kalinkin, P N; Okunev, A G; Rastigeev, S A; Reznikov, V A; Semeykina, V S; Sashkina, K A; Parkhomchuk, V V
2016-09-01
Accelerator mass spectrometry (AMS) was shown to be applicable for studying the penetration of organic aerosols, inhaled by laboratory mice at ultra-low concentration ca. 10(3) cm(-3). We synthesized polystyrene (PS) beads, composed of radiocarbon-labeled styrene, for testing them as model organic aerosols. As a source of radiocarbon we used methyl alcohol with radioactivity. Radiolabeled polystyrene beads were obtained by emulsifier-free emulsion polymerization of synthesized (14)C-styrene initiated by K2S2O8 in aqueous media. Aerosol particles were produced by pneumatic spraying of diluted (14)C-PS latex. Mice inhaled (14)C-PS aerosol consisting of the mix of 10(3) 225-nm particles per 1 cm(3) and 5·10(3) 25-nm particles per 1 cm(3) for 30 min every day during five days. Several millions of 225-nm particles deposited in the lungs and slowly excreted from them during two weeks of postexposure. Penetration of particles matter was also observed for liver, kidneys and brain, but not for a heart.
14. Size distribution dynamics reveal particle-phase chemistry in organic aerosol formation.
PubMed
Shiraiwa, Manabu; Yee, Lindsay D; Schilling, Katherine A; Loza, Christine L; Craven, Jill S; Zuend, Andreas; Ziemann, Paul J; Seinfeld, John H
2013-07-16
Organic aerosols are ubiquitous in the atmosphere and play a central role in climate, air quality, and public health. The aerosol size distribution is key in determining its optical properties and cloud condensation nucleus activity. The dominant portion of organic aerosol is formed through gas-phase oxidation of volatile organic compounds, so-called secondary organic aerosols (SOAs). Typical experimental measurements of SOA formation include total SOA mass and atomic oxygen-to-carbon ratio. These measurements, alone, are generally insufficient to reveal the extent to which condensed-phase reactions occur in conjunction with the multigeneration gas-phase photooxidation. Combining laboratory chamber experiments and kinetic gas-particle modeling for the dodecane SOA system, here we show that the presence of particle-phase chemistry is reflected in the evolution of the SOA size distribution as well as its mass concentration. Particle-phase reactions are predicted to occur mainly at the particle surface, and the reaction products contribute more than half of the SOA mass. Chamber photooxidation with a midexperiment aldehyde injection confirms that heterogeneous reaction of aldehydes with organic hydroperoxides forming peroxyhemiacetals can lead to a large increase in SOA mass. Although experiments need to be conducted with other SOA precursor hydrocarbons, current results demonstrate coupling between particle-phase chemistry and size distribution dynamics in the formation of SOAs, thereby opening up an avenue for analysis of the SOA formation process.
15. Modeling Gas-Particle Partitioning of SOA: Effects of Aerosol Physical State and RH
Zuend, A.; Seinfeld, J.
2011-12-01
Aged tropospheric aerosol particles contain mixtures of inorganic salts, acids, water, and a large variety of organic compounds. In liquid aerosol particles non-ideal mixing of all species determines whether the condensed phase undergoes liquid-liquid phase separation or whether it is stable in a single mixed phase, and whether it contains solid salts in equilibrium with their saturated solution. The extended thermodynamic model AIOMFAC is able to predict such phase states by representing the variety of organic components using functional groups within a group-contribution concept. The number and composition of different condensed phases impacts the diversity of reaction media for multiphase chemistry and the gas-particle partitioning of semivolatile species. Recent studies show that under certain conditions biogenic and other organic-rich particles can be present in a highly viscous, semisolid or amorphous solid physical state, with consequences regarding reaction kinetics and mass transfer limitations. We present results of new gas-particle partitioning computations for aerosol chamber data using a model based on AIOMFAC activity coefficients and state-of-the-art vapor pressure estimation methods. Different environmental conditions in terms of temperature, relative humidity (RH), salt content, amount of precursor VOCs, and physical state of the particles are considered. We show how modifications of absorptive and adsorptive gas-particle mass transfer affects the total aerosol mass in the calculations and how the results of these modeling approaches compare to data of aerosol chamber experiments, such as alpha-pinene oxidation SOA. For a condensed phase in a mixed liquid state containing ammonium sulfate, the model predicts liquid-liquid phase separation up to high RH in case of, on average, moderately hydrophilic organic compounds, such as first generation oxidation products of alpha-pinene. The computations also reveal that treating liquid phases as ideal
16. Real-time characterization of the size and chemical composition of individual particles in ambient aerosol systems in Riverside, California
SciTech Connect
Noble, C.A.; Prather, K.A.
1995-12-31
Atmospheric aerosols, although ubiquitous, are highly diverse and continually fluctuating systems. A typical aerosol system may consist of particles with diameters between {approximately}0.002 {mu}m and {approximately}200 {mu}m. Even in rural or pristine areas, atmospheric particle concentration is significant, with concentrations up to 10{sup 8} particles/cm{sup 3} not being uncommon. Chemical composition of atmospheric particles vary from simple water droplets or acidic ices to soot particles and cigarette smoke. Due to changes in atmospheric conditions, processes such as nucleation, coagulation or heterogeneous chemistry may effect both physical and chemical properties of individual particles over relatively short time intervals. Recently, aerosol measurement techniques are focusing on determining the size and/or chemical composition of individual aerosol particles. This research group has recently developed aerosol time-of-flight mass spectrometry (ATOFMS), a technique which allows for real-time determination of the size and chemical composition of individual aerosol particles. Single particle measurements are performed in one instrument using dual laser aerodynamic particle sizing and time-of-flight mass spectrometry. Aerosol-time-of-flight mass spectrometry is briefly described in several other abstracts in this publication.
17. Elastic back-scattering patterns via particle surface roughness and orientation from single trapped airborne aerosol particles
Fu, Richard; Wang, Chuji; Muñoz, Olga; Videen, Gorden; Santarpia, Joshua L.; Pan, Yong-Le
2017-01-01
We demonstrate a method for simultaneously measuring the back-scattering patterns and images of single laser-trapped airborne aerosol particles. This arrangement allows us to observe how the back-scattering patterns change with particle size, shape, surface roughness, orientation, etc. The recoded scattering patterns cover the angular ranges of θ=167.7-180° (including at 180° exactly) and ϕ=0-360° in spherical coordinates. The patterns show that the width of the average speckle intensity islands or rings is inversely proportional to particle size and how the shape of these intensity rings or islands also depends on the surface roughness. For an irregularly shaped particle with substantial roughness, the back-scattering patterns are formed with speckle intensity islands, the size and orientations of these islands depend more on the overall particle size and orientation, but have less relevance to the fine alteration of the surface structure and shapes. The back-scattering intensity at 180° is very sensitive to the particle parameters. It can change from a maximum to a minimum with a change of 0.1% in particle size or refractive index. The method has potential use in characterizing airborne aerosol particles, and may be used to provide back-scattering information for LIDAR applications.
18. Production, Organic Characterization, and Phase Transformations of Marine Particles Aerosolized from a Laboratory Mesocosm Phytoplankton Bioreactor
Alpert, P. A.; Knopf, D. A.; Aller, J. Y.; Radway, J.; Kilthau, W.
2012-12-01
Previous studies have shown that particles emitted from bubble bursting and wave breaking of ocean waters with high biological activity can contain sea salts associated with organic material, with smaller particles containing a larger mass fraction of organics than larger particles. This likely indicates a link between phytoplankton productivity in oceans and particulate organic material in marine air. Once aerosolized, particles with significant amount of organic material can affect cloud activation and formation of ice crystals, among other atmospheric processes, thus influencing climate. This is significant for clouds and climate particularly over nutrient rich polar seas, in which concentrations of biological organisms can reach up to 109 cells per ml during spring phytoplankton blooms. Here we present results of bubble bursting aerosol production from a seawater mesocosm containing artificial seawater, natural seawater and unialgal cultures of three representative phytoplankton species. These phytoplankton (Thalassiosira pseudonana, Emilianaia huxleyi, and Nannochloris atomus), possessed siliceous frustules, calcareous frustules and no frustules, respectively. Bubbles were generated employing recirculating impinging water jets or glass frits. Dry and humidified aerosol size distributions and bulk aerosol organic composition were measured as a function of phytoplankton growth, and chlorophyll composition and particulate and dissolved organic carbon in the water were determined. Finally, particles were collected on substrates for ice nucleation and water uptake experiments, their elemental compositions were determined using computer controlled scanning electron microscopy and energy dispersive analysis of X-rays (CCSEMEDAX), and their carbon speciation was determined using scanning transmission X-ray microscopy and near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Particle size distributions exposed to dry and humidified air employing
19. Individual Aerosol Particles from Biomass Burning in Southern Africa Compositions and Aging of Inorganic Particles. 2; Compositions and Aging of Inorganic Particles
NASA Technical Reports Server (NTRS)
Li, Jia; Posfai, Mihaly; Hobbs, Peter V.; Buseck, Peter R.
2003-01-01
Individual aerosol particles collected over southern Africa during the SAFARI 2000 field study were studied using transmission electron microscopy and field-emission scanning electron microscopy. The sizes, shapes, compositions, mixing states, surface coatings, and relative abundances of aerosol particles from biomass burning, in boundary layer hazes, and in the free troposphere were compared, with emphasis on aging and reactions of inorganic smoke particles. Potassium salts and organic particles were the predominant species in the smoke, and most were internally mixed. More KCl particles occur in young smoke, whereas more K2SO4 and KNO3 particles were present in aged smoke. This change indicates that with the aging of the smoke, KCl particles from the fires were converted to K2SO4 and KNO3 through reactions with sulfur- and nitrogen- bearing species from biomass burning as well as other sources. More soot was present in smoke from flaming grass fires than bush and wood fires, probably due to the predominance of flaming combustion in grass fires. The high abundance of organic particles and soluble salts can affect the hygroscopic properties of biomass-burning aerosols and therefore influence their role as cloud condensation nuclei. Particles from biomass burning were important constituents of the regional hazes.
20. The single scattering properties of the aerosol particles as aggregated spheres
Wu, Y.; Gu, X.; Cheng, T.; Xie, D.; Yu, T.; Chen, H.; Guo, J.
2012-08-01
The light scattering and absorption properties of anthropogenic aerosol particles such as soot aggregates are complicated in the temporal and spatial distribution, which introduce uncertainty of radiative forcing on global climate change. In order to study the single scattering properties of anthorpogenic aerosol particles, the structures of these aerosols such as soot paticles and soot-containing mixtures with the sulfate or organic matter, are simulated using the parallel diffusion limited aggregation algorithm (DLA) based on the transmission electron microscope images (TEM). Then, the single scattering properties of randomly oriented aerosols, such as scattering matrix, single scattering albedo (SSA), and asymmetry parameter (AP), are computed using the superposition T-matrix method. The comparisons of the single scattering properties of these specific types of clusters with different morphological and chemical factors such as fractal parameters, aspect ratio, monomer radius, mixture mode and refractive index, indicate that these different impact factors can respectively generate the significant influences on the single scattering properties of these aerosols. The results show that aspect ratio of circumscribed shape has relatively small effect on single scattering properties, for both differences of SSA and AP are less than 0.1. However, mixture modes of soot clusters with larger sulfate particles have remarkably important effects on the scattering and absorption properties of aggregated spheres, and SSA of those soot-containing mixtures are increased in proportion to the ratio of larger weakly absorbing attachments. Therefore, these complex aerosols come from man made pollution cannot be neglected in the aerosol retrievals. The study of the single scattering properties on these kinds of aggregated spheres is important and helpful in remote sensing observations and atmospheric radiation balance computations.
1. Stable Carbon Fractionation In Size Segregated Aerosol Particles Produced By Controlled Biomass Burning
Masalaite, Agne; Garbaras, Andrius; Garbariene, Inga; Ceburnis, Darius; Martuzevicius, Dainius; Puida, Egidijus; Kvietkus, Kestutis; Remeikis, Vidmantas
2014-05-01
Biomass burning is the largest source of primary fine fraction carbonaceous particles and the second largest source of trace gases in the global atmosphere with a strong effect not only on the regional scale but also in areas distant from the source . Many studies have often assumed no significant carbon isotope fractionation occurring between black carbon and the original vegetation during combustion. However, other studies suggested that stable carbon isotope ratios of char or BC may not reliably reflect carbon isotopic signatures of the source vegetation. Overall, the apparently conflicting results throughout the literature regarding the observed fractionation suggest that combustion conditions may be responsible for the observed effects. The purpose of the present study was to gather more quantitative information on carbonaceous aerosols produced in controlled biomass burning, thereby having a potential impact on interpreting ambient atmospheric observations. Seven different biomass fuel types were burned under controlled conditions to determine the effect of the biomass type on the emitted particulate matter mass and stable carbon isotope composition of bulk and size segregated particles. Size segregated aerosol particles were collected using the total suspended particle (TSP) sampler and a micro-orifice uniform deposit impactor (MOUDI). The results demonstrated that particle emissions were dominated by the submicron particles in all biomass types. However, significant differences in emissions of submicron particles and their dominant sizes were found between different biomass fuels. The largest negative fractionation was obtained for the wood pellet fuel type while the largest positive isotopic fractionation was observed during the buckwheat shells combustion. The carbon isotope composition of MOUDI samples compared very well with isotope composition of TSP samples indicating consistency of the results. The measurements of the stable carbon isotope ratio in
2. The effect of phase partitioning of semivolatile compounds on the measured CCN activity of aerosol particles
Romakkaniemi, S.; Jaatinen, A.; Laaksonen, A.; Nenes, A.; Raatikainen, T.
2013-09-01
The effect of inorganic semivolatile aerosol compounds on the CCN activity of aerosol particles was studied by using a computational model for a DMT-CCN counter, a cloud parcel model for condensation kinetics and experiments to quantify the modelled results. Concentrations of water vapour and semivolatiles as well as aerosol trajectories in the CCN column were calculated by a computational fluid dynamics model. These trajectories and vapour concentrations were then used as an input for the cloud parcel model to simulate mass transfer kinetics of water and semivolatiles between aerosol particles and the gas phase. Two different questions were studied: (1) how big fraction of semivolatiles is evaporated from particles before activation in the CCN counter? (2) How much the CCN activity can be increased due to condensation of semivolatiles prior to the maximum water supersaturation in the case of high semivolatile concentration in the gas phase? The results show that, to increase the CCN activity of aerosol particles, a very high gas phase concentration (as compared to typical ambient conditions) is needed. We used nitric acid as a test compound. A concentration of several ppb or higher is needed for measurable effect. In the case of particle evaporation, we used ammonium nitrate as a test compound and found that it partially evaporates before maximum supersaturation is reached in the CCN counter, thus causing an underestimation of CCN activity. The effect of evaporation is clearly visible in all supersaturations, leading to an underestimation of the critical dry diameter by 10 to 15 nanometres in the case of ammonium nitrate particles in different supersaturations. This result was also confirmed by measurements in supersaturations between 0.1 and 0.7%.
3. Urban organic aerosols measured by single particle mass spectrometry in the megacity of London
Dall'Osto, M.; Harrison, R. M.
2011-02-01
During the month of October 2006, as part of the REPARTEE-I experiment (Regent's Park and Tower Environmental Experiment) an Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed at an urban background location in the city of London, UK. Fifteen particle types were classified, some of which were accompanied by Aerosol Mass Spectrometer (AMS) quantitative aerosol mass loading measurements (Dall'Osto et al., 2009a, b). In this manuscript the origins and properties of four particle types associated with locally generated aerosols, independent of the air mass type advected into London, are examined. One particle type, originating from lubricating oil (referred to as Ca-EC), was associated with morning rush hour traffic emissions. A second particle type, composed of both inorganic and organic species (called Na-EC-OC), was found enhanced in particle number concentration during evening time periods, and is likely to originate from a source operating at this time of day, or more probably from condensation of semi-volatile species, and contains both primary and secondary components. A third class, internally mixed with organic carbon and sulphate (called OC), was found to spike both in the morning and evenings. The fourth class (SOA-PAH) exhibited maximum frequency during the warmest part of the day, and a number of factors point towards secondary production from traffic-related volatile aromatic compounds. Single particle mass spectra of this particle type showed an oxidized polycyclic aromatic compound signature. Finally, a comparison of ATOFMS particle class data is made with factors obtained by Positive Matrix Factorization from AMS data.. Both the Ca-EC and OC particle types correlate with the AMS HOA primary organic fraction (R2 = 0.65 and 0.50 respectively), and Na-EC-OC, but not SOA-PAH, which correlates weakly with the AMS OOA secondary organic aerosol factor (R2 = 0.35). A detailed analysis was conducted to identify ATOFMS particle type(s) representative
4. A CAM (continuous air monitor) sampler for collecting and assessing alpha-emitting aerosol particles
SciTech Connect
McFarland, A.R.; Bethel, E.L.; Ortiz, C.A.; Stanke, J.G. )
1991-07-01
A new continuous air monitor (CAM) sampler for assessing alpha-emitting transuranic aerosol particles has been developed. The system has been designed to permit collection of particles that can potentially penetrate into the thoracic region of the human respiratory system. Wind tunnel testing of the sampler has been used to characterize the penetration of aerosol to the collection filter. Results show that greater than or equal to 50% of 10-micrograms aerodynamic equivalent diameter (AED) particles are collected by the filter at wind speeds of 0.3 to 2 m s-1 and at sampling flow rates of 28 to 113 L min-1 (1 to 4 cfm). The deposition of 10-microns AED particles takes place primarily in the center of the filter, where the counting efficiency of the detector is highest.
5. Individual particle morphology, coatings, and impurities of black carbon aerosols in Antarctic ice and tropical rainfall
Ellis, Aja; Edwards, Ross; Saunders, Martin; Chakrabarty, Rajan K.; Subramanian, R.; Timms, Nicholas E.; Riessen, Arie; Smith, Andrew M.; Lambrinidis, Dionisia; Nunes, Laurie J.; Vallelonga, Paul; Goodwin, Ian D.; Moy, Andrew D.; Curran, Mark A. J.; Ommen, Tas D.
2016-11-01
Black carbon (BC) aerosols are a large source of climate warming, impact atmospheric chemistry, and are implicated in large-scale changes in atmospheric circulation. Inventories of BC emissions suggest significant changes in the global BC aerosol distribution due to human activity. However, little is known regarding BC's atmospheric distribution or aged particle characteristics before the twentieth century. Here we investigate the prevalence and structural properties of BC particles in Antarctic ice cores from 1759, 1838, and 1930 Common Era (C.E.) using transmission electron microscopy and energy-dispersive X-ray spectroscopy. The study revealed an unexpected diversity in particle morphology, insoluble coatings, and association with metals. In addition to conventionally occurring BC aggregates, we observed single BC monomers, complex aggregates with internally, and externally mixed metal and mineral impurities, tar balls, and organonitrogen coatings. The results of the study show BC particles in the remote Antarctic atmosphere exhibit complexity that is unaccounted for in atmospheric models of BC.
6. Dissolution of aerosol particles collected from nuclear facility plutonium production process
DOE PAGES
Xu, Ning; Martinez, Alexander; Schappert, Michael Francis; ...
2015-08-14
Here, a simple, robust analytical chemistry method has been developed to dissolve plutonium containing particles in a complex matrix. The aerosol particles collected on Marple cascade impactor substrates were shown to be dissolved completely with an acid mixture of 12 M HNO3 and 0.1 M HF. A pressurized closed vessel acid digestion technique was utilized to heat the samples at 130 °C for 16 h to facilitate the digestion. The dissolution efficiency for plutonium particles was 99 %. The resulting particle digestate solution was suitable for trace elemental analysis and isotope composition determination, as well as radiochemistry measurements.
7. Pulse height response of an optical particle counter to monodisperse aerosols
NASA Technical Reports Server (NTRS)
Wilmoth, R. G.; Grice, S. S.; Cuda, V.
1976-01-01
The pulse height response of a right angle scattering optical particle counter has been investigated using monodisperse aerosols of polystyrene latex spheres, di-octyl phthalate and methylene blue. The results confirm previous measurements for the variation of mean pulse height as a function of particle diameter and show good agreement with the relative response predicted by Mie scattering theory. Measured cumulative pulse height distributions were found to fit reasonably well to a log normal distribution with a minimum geometric standard deviation of about 1.4 for particle diameters greater than about 2 micrometers. The geometric standard deviation was found to increase significantly with decreasing particle diameter.
8. Dissolution of aerosol particles collected from nuclear facility plutonium production process
SciTech Connect
Xu, Ning; Martinez, Alexander; Schappert, Michael Francis; Montoya, Dennis Patrick; Martinez, Patrick Thomas; Tandon, Lav
2015-08-14
Here, a simple, robust analytical chemistry method has been developed to dissolve plutonium containing particles in a complex matrix. The aerosol particles collected on Marple cascade impactor substrates were shown to be dissolved completely with an acid mixture of 12 M HNO3 and 0.1 M HF. A pressurized closed vessel acid digestion technique was utilized to heat the samples at 130 °C for 16 h to facilitate the digestion. The dissolution efficiency for plutonium particles was 99 %. The resulting particle digestate solution was suitable for trace elemental analysis and isotope composition determination, as well as radiochemistry measurements.
9. TOTAL PARTICLE, SULFATE, AND ACIDIC AEROSOL EMISSIONS FROM KEROSENE SPACE HEATERS
EPA Science Inventory
Chamber studies were conducted on four unvented kerosene space heaters to assess emissions of total particle, sulfate, and acidic aerosol. The heaters tested represented four burner designs currently in use by the public. Kerosene space heaters are a potential source of fine part...
10. Total reflection X-ray fluorescence (TXRF) for direct analysis of aerosol particle samples.
PubMed
Bontempi, E; Zacco, A; Benedetti, D; Borgese, L; Colombi, P; Stosnach, H; Finzi, G; Apostoli, P; Buttini, P; Depero, L E
2010-04-14
Atmospheric aerosol particles have a great impact on the environment and on human health. Routine analysis of the particles usually involves only the mass determination. However, chemical composition and phases provide fundamental information about the particles' origins and can help to prevent health risks. For example, these particles may contain heavy metals such as Pb, Ni and Cd, which can adversely affect human health. In this work, filter samples were collected in Brescia, an industrial town located in Northern Italy. In order to identify the chemical composition and the phases of the atmospheric aerosols, the samples were analysed by means of total reflection X-ray fluorescence (TXRF) spectrometry with a laboratory instrument and X-ray microdiffraction at Synchrotron Daresbury Laboratories, Warrington (Cheshire, UK). The results are discussed and correlated to identify possible pollution sources. The novelty of this analytical approach is that filter samples for TXRF were analysed directly and did not require chemical pretreatment to leach elements from the aerosol particulates. The results of this study clearly show that TXRF is a powerful technique for the analysis of atmospheric aerosols on 'as-received' filters, thereby leaving samples intact and unaltered for possible subsequent analyses by other methods. In addition, the low detection limits for many elements (low ng/cm2) indicate that this method may hold promise in various application fields, such as nanotechnology.
11. USE OF CONTINUOUS MEASUREMENTS OF INTEGRAL AEROSOL PARAMETERS TO ESTIMATE PARTICLE SURFACE AREA
EPA Science Inventory
This study was undertaken because of interest in using particle surface area as an indicator for studies of the health effects of particulate matter. First, we wished to determine the integral parameter of the size distribution measured by the electrical aerosol detector. Secon...
12. Aerosol Particle Interfacial Thermodynamics and Phase Partitioning Measurements Using Biphasic Microfluidics
Dutcher, Cari; Metcalf, Andrew
2015-03-01
Secondary organic aerosol particles are nearly ubiquitous in the atmosphere and yet there remain large uncertainties in their formation processes and ambient properties. These particles are complex microenvironments, which can contain multiple interfaces due to internal aqueous-organic phase partitioning and to the external liquid-vapor surface. Interfacial properties affect the ambient aerosol morphology, or internal structure of the particle, which in turn can affect the way a particle interacts with an environment of condensable clusters and organic vapors. To improve our ability to accurately predict ambient aerosol morphology, we must improve our knowledge of aerosol interfaces and their interactions with the ambient environment. Unfortunately, many techniques employed to measure interfacial properties do so in bulk solutions or in the presence of a ternary (e.g. solid) phase. In this talk, a novel method using biphasic microscale flows will be introduced for generating, trapping, and perturbing complex interfaces at atmospherically relevant conditions. These microfluidic experiments utilize high-speed imaging to monitor interfacial phenomena at the microscale and are performed with phase contrast and fluorescence microscopy on a temperature-controlled inverted microscope stage. From these experiments, interfacial thermodynamic properties such as surface or interfacial tension, rheological properties such as interfacial moduli, and kinetic properties such as mass transfer coefficients can be measured or inferred.
13. Deposition of aerosol particles in human lungs: in vivo measurements and modeling
EPA Science Inventory
The deposition dose and site of inhaled particles within the lung are the key determinants in health risk assessment of particulate pollutants. Accurate dose estimation, however, is a formidable task because aerosol transport and deposition in the lung are governed by many factor...
14. Modeling Aerosol Particle Deposition on a Person Using Computational Fluid Dynamics
DTIC Science & Technology
numerical simulations of aerosol particle deposition on the human form. Numerical simulation of a two-phase turbulent impinging jet flow is studied to...validation show that the standard EIM with turbulent tracking tends to over predict the deposition efficiency. Greatly improved results were achieved by
15. A Novel Aerosol Method for the Production of Hydrogel Particles
PubMed Central
Guzman-Villanueva, Diana; Smyth, Hugh D. C.; Herrera-Ruiz, Dea; El-Sherbiny, Ibrahim M.
2012-01-01
A novel method of generating hydrogel particles for various applications including drug delivery purposes was developed. This method is based on the production of hydrogel particles from sprayed polymeric nano/microdroplets obtained by a nebulization process that is immediately followed by gelation in a crosslinking fluid. In this study, particle synthesis parameters such as type of nebulizer, type of crosslinker, air pressure, and polymer concentration were investigated for their impact on the mean particle size, swelling behavior, and morphology of the developed particles. Spherical alginate-based hydrogel particles with a mean particle size in the range from 842 to 886 nm were obtained. Using statistical analysis of the factorial design of experiment it was found that the main factors influencing the size and swelling values of the particles are the alginate concentration and the air pressure. Thus, it was demonstrated that the method described in the current study is promising for the generation of hydrogel particles and it constitutes a relatively simple and low-cost system. PMID:23687513
16. Online Aerosol Mass Spectrometry of Single Micrometer-Sized Particles Containing Poly(ethylene glycol)
SciTech Connect
Bogan, M J; Patton, E; Srivastava, A; Martin, S; Fergenson, D; Steele, P; Tobias, H; Gard, E; Frank, M
2006-10-25
Analysis of poly(ethylene glycol)(PEG)-containing particles by online single particle aerosol mass spectrometers equipped with laser desorption ionization (LDI) is reported. We demonstrate that PEG-containing particles are useful in the development of aerosol mass spectrometers because of their ease of preparation, low cost, and inherently recognizable mass spectra. Solutions containing millimolar quantities of PEGs were nebulized and, after drying, the resultant micrometer-sized PEG containing particles were sampled. LDI (266 nm) of particles containing NaCl and PEG molecules of average molecular weight <500 generated mass spectra reminiscent of mass spectra of PEG collected by other MS schemes including the characteristic distribution of positive ions (Na{sup +} adducts) separated by the 44 Da of the ethylene oxide units separating each degree of polymerization. PEGs of average molecular weight >500 were detected from particles that also contained t the tripeptide tyrosine-tyrosine-tyrosine or 2,5-dihydroxybenzoic acid, which were added to nebulized solutions to act as matrices to assist LDI using pulsed 266 nm and 355 nm lasers, respectively. Experiments were performed on two aerosol mass spectrometers, one reflectron and one linear, that each utilize two time-of-flight mass analyzers to detect positive and negative ions created from a single particle. PEG-containing particles are currently being employed in the optimization of our bioaerosol mass spectrometers for the application of measurements of complex biological samples, including human effluents, and we recommend that the same strategies will be of great utility to the development of any online aerosol LDI mass spectrometer platform.
17. Chemical characterization of submicron aerosol particles during wintertime in a northwest city of China using an Aerodyne aerosol mass spectrometry.
PubMed
Zhang, Xinghua; Zhang, Yangmei; Sun, Junying; Yu, Yangchun; Canonaco, Francesco; Prévôt, Andre S H; Li, Gang
2017-03-01
An Aerodyne quadrupole aerosol mass spectrometry (Q-AMS) was utilized to measure the size-resolved chemical composition of non-refractory submicron particles (NR-PM1) from October 27 to December 3, 2014 at an urban site in Lanzhou, northwest China. The average NR-PM1 mass concentration was 37.3 μg m(-3) (ranging from 2.9 to 128.2 μg m(-3)) under an AMS collection efficiency of unity and was composed of organics (48.4%), sulfate (17.8%), nitrate (14.6%), ammonium (13.7%), and chloride (5.7%). Positive matrix factorization (PMF) with the multi-linear engine (ME-2) solver identified six organic aerosol (OA) factors, including hydrocarbon-like OA (HOA), coal combustion OA (CCOA), cooking-related OA (COA), biomass burning OA (BBOA) and two oxygenated OA (OOA1 and OOA2), which accounted for 8.5%, 20.2%, 18.6%, 12.4%, 17.8% and 22.5% of the total organics mass on average, respectively. Primary emissions were the major sources of fine particulate matter (PM) and played an important role in causing high chemically resolved PM pollution during wintertime in Lanzhou. Back trajectory analysis indicated that the long-range regional transport air mass from the westerly was the key factor that led to severe submicron aerosol pollution during wintertime in Lanzhou.
18. Particle size analysis of radioactive aerosols formed by irradiation of argon using 65 MeV quasi-monoenergetic neutrons.
PubMed
Endo, A; Noguchi, H; Tanaka, Su; Kanda, Y; Oki, Y; Iida, T; Sato, K; Tsuda, S
2002-04-01
The size distributions of 38Cl and 39Cl aerosols formed from the irradiation of argon gas containing di-octyl phthalate (DOP) aerosols by 65 MeV quasi-monoenergetic neutrons were measured to study the formation mechanism of radioactive aerosols in high-energy radiation fields. Both the number size distribution and the activity-weighted size distribution were measured using an electrical low-pressure impactor. It was found that the 35Cl and 39Cl aerosols are formed by attachment of the radioactive atoms generated by the neutron-induced reaction to the DOP aerosol particles.
19. Oxidative aging of mixed oleic acid/sodium chloride aerosol particles
Dennis-Smither, Benjamin J.; Miles, Rachael E. H.; Reid, Jonathan P.
2012-10-01
Studies of the oxidative aging of single mixed component aerosol particles formed from oleic acid (OL) and sodium chloride over a range of relative humidities (RH) and ozone concentrations by aerosol optical tweezers are reported. The rate of loss of OL and changes in the organic phase volume are directly measured, comparing particles with effloresced and deliquesced inorganic seeds. The kinetics of the OL loss are analyzed and the value of the reactive uptake coefficient of ozone by OL is compared to previous studies. The reaction of OL is accompanied by a decrease in the particle volume, consistent with the evaporation of semivolatile products over a time scale of tens of thousands of seconds. Measurements of the change in the organic phase volume allow the branching ratio to involatile components to be estimated; between 50 and 85% of the initial organic volume remains involatile, depending on ozone concentration. The refractive index (RI) of the organic phase increases during and after evaporation of volatile products, consistent with aging followed by a slow restructuring in particle morphology. The hygroscopicity of the particle and kinetics of the response of the organic phase to changes in RH are investigated. Both size and RI of unoxidized and oxidized particles respond promptly to RH changes with values of the RI consistent with linear mixing rules. Such studies of the simultaneous changes in composition and size of mixed component aerosol provide valuable data for benchmarking kinetic models of heterogeneous atmospheric aging.
20. Phoretic forces on aerosol particles surrounding an evaporating droplet in microgravity conditions
Prodi, F.; Santachiara, G.; Belosi, F.; Vedernikov, A.; Balapanov, D.
2014-06-01
The work presents the results of an experimental campaign performed at the Drop Tower Facility (Bremen) in microgravity conditions, concerning the scavenging process of an evaporating single droplet in stationary conditions. In the experimental conditions the thermo- and diffusiophoretic forces are the only ones that can determine the scavenging of the aerosol. The research is finalized to help solve the open question concerning the contribution of thermo- and diffusiophoretic forces in aerosol scavenging process due to cloud droplets. Although earlier theoretical and experimental papers have addressed this problem, the results are contradictory and inconclusive. As phoretic forces depend on aerosol diameter and water vapour pressure gradient, experiments were performed by changing the aerosol diameter (range 0.4 μm-2 μm) and the water vapour gradient. The experimental results show a prevalence of the diffusiophoretic over thermophoretic force, for the considered aerosol. The measured values of the particle velocities due to phoretic forces increase with increasing aerosol diameter and vapour pressure gradient.
1. Seasonal Variation of Aerosol Particle Size Using MER/Pancam Sky Imaging
Smith, M. D.; Wolff, M. J.
2013-12-01
Imaging of the sky taken by the Pancam cameras on-board the Mars Exploration Rovers (MER) provide a useful tool for determining the optical depth and physcial properties of aerosols above the rover. Specifically, the brightness of the sky as a function of angle away from the Sun provides a powerful constraint on the size distribution and shape of dust and water ice aerosols. More than 100 Pancam "sky surveys" were taken by each of the two MER rovers covering a time span of several Mars years and a wide range of dust loading conditions including the planet-encirclind dust storm during Mars Year 28 (Earth year 2007). These sky surveys enable the time evolution of aerosol particle size to be determined including its relation to dust loading. Radiative transfer modeling is used to model the observations. Synthetic Pancam sky brightness is computed using a discrete-ordinates radiative transfer code that accounts for multiple scattering from aerosols and spherical geometry by integrating the source functions along curved paths in that coordinate system. We find that Mie scattering from spheres is not a good approximation for describing the angular variation of sky brightness far from the Sun (at scattering angles greater than 45 degrees). Significant seasonal variations are seen in the retrieved effective radius of the aerosols with higher optical depth strongly correlated with larger particle size.
2. Airborne minerals and related aerosol particles: Effects on climate and the environment
PubMed Central
Buseck, Peter R.; Pósfai, Mihály
1999-01-01
Aerosol particles are ubiquitous in the troposphere and exert an important influence on global climate and the environment. They affect climate through scattering, transmission, and absorption of radiation as well as by acting as nuclei for cloud formation. A significant fraction of the aerosol particle burden consists of minerals, and most of the remainder— whether natural or anthropogenic—consists of materials that can be studied by the same methods as are used for fine-grained minerals. Our emphasis is on the study and character of the individual particles. Sulfate particles are the main cooling agents among aerosols; we found that in the remote oceanic atmosphere a significant fraction is aggregated with soot, a material that can diminish the cooling effect of sulfate. Our results suggest oxidization of SO2 may have occurred on soot surfaces, implying that even in the remote marine troposphere soot provided nuclei for heterogeneous sulfate formation. Sea salt is the dominant aerosol species (by mass) above the oceans. In addition to being important light scatterers and contributors to cloud condensation nuclei, sea-salt particles also provide large surface areas for heterogeneous atmospheric reactions. Minerals comprise the dominant mass fraction of the atmospheric aerosol burden. As all geologists know, they are a highly heterogeneous mixture. However, among atmospheric scientists they are commonly treated as a fairly uniform group, and one whose interaction with radiation is widely assumed to be unpredictable. Given their abundances, large total surface areas, and reactivities, their role in influencing climate will require increased attention as climate models are refined. PMID:10097046
3. Real-time measurement of sodium chloride in individual aerosol particles by mass spectrometry
NASA Technical Reports Server (NTRS)
Sinha, M. P.; Friedlander, S. K.
1985-01-01
The method of particle analysis by mass spectrometry has been applied to the quantitative measurement of sodium chloride in individual particles on a real-time basis. Particles of known masses are individually introduced, in the form of a beam, into a miniature Knudsen cell oven (1600 K). The oven is fabricated from rhenium metal sheet (0.018 mm thick) and is situated in the ion source of a quadrupole mass spectrometer. A particle once inside the oven is trapped and completely volatilized; this overcomes the problem of partial volatilization due to particles bouncing from the filament surface. Individual particles are thermally volatilized and ionized inside the rhenium oven, and produce discrete sodium ion pulses whose intensities are measured with the quadrupole mass spectrometer. An ion pulse width of several milliseconds (4-12 ms) is found for particles in the mass range 1.3 x 10 to the -13th to 5.4 x 10 to the -11th g. The sodium ion intensity is found to be proportional to the particle mass to the 0.86-power. The intensity distribution for monodisperse aerosol particles possesses a geometric standard deviation of 1.09, showing that the method can be used for the determination of the mass distribution function with good resolution in a polydisperse aerosol.
4. The Effect of Particle Size on Iron Solubility in Atmospheric Aerosols
Marcotte, A. R.; Majestic, B. J.; Anbar, A. D.; Herckes, P.
2012-12-01
The long range transport of mineral dust aerosols, which contain approximately 3% iron by mass, results in an estimated 14-16 Tg of iron deposited into the oceans annually; however, only a small percentage of the deposited iron is soluble. In high-nutrient, low chlorophyll ocean regions iron solubility may limit phytoplankton primary productivity. Although the atmospheric transport processes of mineral dust aerosols have been well studied, the role of particle size has been given little attention. In this work, the effect of particle size on iron solubility in atmospheric aerosols is examined. Iron-containing minerals (illite, kaolinite, magnetite, goethite, red hematite, black hematite, and quartz) were separated into five size fractions (10-2.5, 2.5-1, 1-0.5, 0.5-0.25, and <0.25μm) and extracted into buffer solutions simulating environments in the transport of aerosol particles for 150 minutes. Particle size was confirmed by scanning electron microscopy (SEM). Soluble iron content of the extracted mineral solutions was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Extracted mineral solutions were also analyzed for Fe(II) and Fe(III) content using a ferrozine/UV-VIS method. Preliminary results show that differences in solution composition are more important than differences in size. When extracted into acetate and cloudwater buffers (pH 4.25-4.3), < 0.3% of the Fe in iron oxides (hematite, magnetite, and goethite) is transferred to solution as compared to ~0.1-35% for clays (kaolinite and illite). When extracted into a marine aerosol solution (pH 1.7), the percentage of Fe of the iron oxides and clays transferred to solution increases to approximately 0.5-3% and 5-70%, respectively. However, there is a trend of increased %Fe in the minerals transferred to solution in the largest and smallest size fractions (~0.01-0.3% and ~0.5-35% for iron oxides and clays, respectively), and decreased %Fe in the minerals transferred to solution in the mid
5. Surface tensions, viscosities, and diffusion constants in mixed component single aerosol particles
Bzdek, Bryan; Marshall, Frances; Song, Young-Chul; Haddrell, Allen; Reid, Jonathan
2016-04-01
Surface tension and viscosity are important aerosol properties but are challenging to measure on individual particles owing to their small size and mass. Aerosol viscosity impacts semivolatile partitioning from the aerosol phase, molecular diffusion in the bulk of the particle, and reaction kinetics. Aerosol surface tension impacts how particles activate to serve as cloud condensation nuclei. Knowledge of these properties and how they change under different conditions hinders accurate modelling of aerosol physical state and atmospheric impacts. We present measurements made using holographic optical tweezers to directly determine the viscosity and surface tension of optically trapped droplets containing ~1-4 picolitres of material (corresponding to radii of ~5-10 micrometres). Two droplets are captured in the experimental setup, equilibrated to a relative humidity, and coalesced through manipulation of the relative trap positions. The moment of coalescence is captured using camera imaging as well as from elastically backscattered light connected to an oscilloscope. For lower viscosity droplets, the relaxation in droplet shape to a sphere follows the form of a damped oscillator and gives the surface tension and viscosity. For high viscosity droplets, the relaxation results in a slow merging of the two droplets to form a sphere and the timescale of that process permits determination of viscosity. We show that droplet viscosity and surface tension can be quantitatively determined to within <10% of the expected value for low viscosity droplets and to better than 1 order of magnitude for high viscosity droplets. Examples illustrating how properties such as surface tension can change in response to environmental conditions will be discussed. Finally, a study of the relationship between viscosity, diffusion constants, vapour pressures, and reactive uptake coefficients for a mixed component aerosol undergoing oxidation and volatilisation will be discussed.
6. Gas-particle partitioning of semivolatile organic compounds (SOCs) on mixtures of aerosols in a smog chamber.
PubMed
Chandramouli, Bharadwaj; Jang, Myoseon; Kamens, Richard M
2003-09-15
The partitioning behavior of a set of diverse SOCs on two and three component mixtures of aerosols from different sources was studied using smog chamber experimental data. A set of SOCs of different compound types was introduced into a system containing a mixture of aerosols from two or more sources. Gas and particle samples were taken using a filter-filter-denuder sampling system, and a partitioning coefficient Kp was estimated using Kp = Cp/(CgTSP). Particle size distributions were measured using a differential mobility analyzer and a light scattering detector. Gas and particle samples were analyzed using GCMS. The aerosol composition in the chamber was tracked chemically using a combination of signature compounds and the organic matter mass fraction (f(om)) of the individual aerosol sources. The physical nature of the aerosol mixture in the chamber was determined using particle size distributions, and an aggregate Kp was estimated from theoretically calculated Kp on the individual sources. Model fits for Kp showed that when the mixture involved primary sources of aerosol, the aggregate Kp of the mixture could be successfully modeled as an external mixture of the Kp on the individual aerosols. There were significant differences observed for some SOCs between modeling the system as an external and as an internal mixture. However, when one of the aerosol sources was secondary, the aggregate model Kp required incorporation of the secondary aerosol products on the preexisting aerosol for adequate model fits. Modeling such a system as an external mixture grossly overpredicted the Kp of alkanes in the mixture. Indirect evidence of heterogeneous, acid-catalyzed reactions in the particle phase was also seen, leading to a significant increase in the polarity of the resulting aerosol mix and a resulting decrease in the observed Kp of alkanes in the chamber. The model was partly consistent with this decrease but could not completely explain the reduction in Kp because of
7. Retrieving the aerosol particle distribution in Titan's detached layer from ISS limb observations
Seignovert, B.; Rannou, P.; Lavvas, P.; Cours, T.; West, R. A.
2015-10-01
The study of the detached haze layer above Titan's thick atmosphere is one of the key elements to understand the growth of the aerosols in the upper atmosphere of Titan. In this work we will present the results of a radiative transfer inversion of the vertical profile distribution of aerosols in the detached haze layer (from 300 to 600 km) by using the I/F ratio ob- served by Cassini ISS camera. The analyses will focus on the derivation of the particle size distribution.
8. Atmospheric budget of different elements in aerosol particles over Hungary
Molnár, A.; Mészáros, E.; Polyák, K.; Borbély-Kiss, I.; Koltay, E.; Szabó, Gy.; Horváth, Zs.
The aim of this paper is to present the budget of seven elements (Cd, Cu, Mn, Ni, Pb, V and Zn) in the atmospheric aerosol over Hungary. The dry deposition is estimated on the basis of concentration and size distribution measurements and on dry deposition velocities available in the literature. The dry deposition velocity of two elements is obtained by transport model calculations. Wet deposition rates are determined by analyzing precipitation samples. The emissions of different elements necessary for budgeting are calculated by using statistical data on fossil fuel and gasoline burning, metallurgy, cement industry and waste incineration as well as on emission factors given by Pacyna (1984, Atmospheric Environment18, 41-50). It is found that the country is a net source for elements produced mostly by fossil fuel combustion while it is a net sink for elements released during industrial processes and automotive transport.
9. Hazardous particle binder, coagulant and re-aerosolization inhibitor
DOEpatents
Krauter, Paula; Zalk, David; Hoffman, D. Mark
2011-04-12
A copolymer and water/ethanol solvent solution capable of binding with airborne contaminants or potential airborne contaminants, such as biological weapon agents or toxic particulates, coagulating as the solvent evaporates, and adhering the contaminants to a surface so as to inhibit the re-suspension of such contaminants. The solution uses a water or ethanol/water mixture for the solvent, and a copolymer having one of several functional group sets so as to have physical and chemical characteristics of high adhesion, low viscosity, low surface tension, negative electrostatic charge, substantially neutral pH, and a low pKa. Use of the copolymer solution prevents re-aerosolization and transport of unwanted, reactive species thus increasing health and safety for personnel charged with decontamination of contaminated buildings and areas.
10. Hazardous particle binder, coagulant and re-aerosolization inhibitor
DOEpatents
Krauter, Paula; Zalk, David; Hoffman, D. Mark
2012-07-10
A copolymer and water/ethanol solvent solution capable of binding with airborne contaminants or potential airborne contaminants, such as biological weapon agents or toxic particulates, coagulating as the solvent evaporates, and adhering the contaminants to a surface so as to inhibit the re-suspension of such contaminants. The solution uses a water or ethanol/water mixture for the solvent, and a copolymer having one of several functional group sets so as to have physical and chemical characteristics of high adhesion, low viscosity, low surface tension, negative electrostatic charge, substantially neutral pH, and a low pKa. Use of the copolymer solution prevents re-aerosolization and transport of unwanted, reactive species thus increasing health and safety for personnel charged with decontamination of contaminated buildings and areas.
11. Single particle characterization using a light scattering module coupled to a time-of-flight aerosol mass spectrometer
SciTech Connect
Cross, E.; Onasch, Timothy B.; Canagaratna, Manjula; Jayne, J. T.; Kimmel, Joel; Yu, Xiao-Ying; Alexander, M. L.; Worsnop, Douglas R.; Davidovits, Paul
2009-10-01
To accurately model the radiative forcing of aerosol particles, one must measure in real-time the size, shape, density, chemical composition, and mixing state of ambient particles. This is a formidable challenge because the chemical and physical properties of the aerosol particles are highly complex, dependent on the emission sources, the geography and meteorology of the surroundings, and the gas phase composition of the regional atmosphere.
12. Advances in Quantifying the Radiative Effects of Aerosol Particles on Climate from Airborne Field Studies
Pilewskie, P.; Schmidt, K. S.; Coddington, O.; Bergstrom, R.; Redemann, J.
2007-12-01
In the fourth assessment report of the Intergovernmental Panel on Climate Change, large uncertainties persist in estimates of climate forcing by aerosol particles. One contributor to this uncertainty is the poorly quantified vertical distribution of solar radiation absorbed by aerosol particles, from the regional to global scale. Another is the spectral and spatial variability of surface albedo, an effect that can dominate the top-of-atmosphere perturbations due to aerosol scattering and absorption, particularly over land. Over the past three years a number of intensive airborne field experiments (ICARTT, MILAGRO, GoMACCS) have contributed significantly to our understanding of the impact of pollution outflow from urban-industrial centers on radiative forcing, using spectrally resolved radiometric measurements and novel observationally-based methods to derive forcing efficiency and flux divergence. We present an overview of some of the most significant advances in direct radiative forcing realized by these studies, and recommendations on where the greatest challenges remain. In addition we present findings from these experiments on the influence of aerosol particles on cloud radiative properties, a potentially greater effect but even more uncertain than direct radiative forcing.
13. Interfacial Tensions of Aged Organic Aerosol Particle Mimics Using a Biphasic Microfluidic Platform.
PubMed
Metcalf, Andrew R; Boyer, Hallie C; Dutcher, Cari S
2016-02-02
Secondary organic aerosol (SOA) particles are a major component of atmospheric particulate matter, yet their formation processes and ambient properties are not well understood. These complex particles often contain multiple interfaces due to internal aqueous- and organic-phase partitioning. Aerosol interfaces can profoundly affect the fate of condensable organic compounds emitted into the atmosphere by altering the way in which ambient organic vapors interact with suspended particles. To accurately predict the evolution of SOA in the atmosphere, we must improve our understanding of aerosol interfaces. In this work, biphasic microscale flows are used to measure interfacial tension of reacting methylglyoxal, formaldehyde, and ammonium sulfate aqueous mixtures with a surrounding oil phase. Our experiments show a suppression of interfacial tension as a function of organic content that remains constant with reaction time for methylglyoxal-ammonium sulfate systems. We also reveal an unexpected time dependence of interfacial tension over a period of 48 h for ternary solutions of both methylglyoxal and formaldehyde in aqueous ammonium sulfate, indicating a more complicated behavior of surface activity where there is competition among dissolved organics. From these interfacial tension measurements, the morphology of aged atmospheric aerosols with internal liquid-liquid phase separation is inferred.
14. REDOX AND ELECTROPHILIC PROPERTIES OF VAPOR- AND PARTICLE-PHASE COMPONENTS OF AMBIENT AEROSOLS
PubMed Central
Eiguren-Fernandez, Arantzazu; Shinyashiki, Masaru; Schmitz, Debra A.; DiStefano, Emma; Hinds, William; Kumagai, Yoshito; Cho, Arthur K.; Froines, John R.
2010-01-01
Particulate matter (PM) has been the primary focus of studies aiming to understand the relationship between the chemical properties of ambient aerosols and adverse health effects. Size and chemical composition of PM have been linked to their oxidative capacity which has been postulated to promote or exacerbate pulmonary and cardiovascular diseases. But in the last few years, new studies have suggested that volatile and semivolatile components may also contribute to many adverse health effects. The objectives of this study were: i) assess for the first time the redox and electrophilic potential of vapor-phase components of ambient aerosols, and ii) evaluate the relative contributions of particle- and vapor-fractions to the hazard of a given aerosol. To achieve these objectives vapor- and particle-phase samples collected in Riverside (CA) were subjected to three chemical assays to determine their redox and electrophilic capacities. The results indicate that redox active components are mainly associated with the particle-phase, while electrophilic compounds are found primarily in the vapor-phase. Vapor-phase organic extracts were also capable of inducing the stress responding protein, heme-oxygenase-1 (HO-1), in RAW264.7 murine macrophages. These results demonstrate the importance of volatile components in the overall oxidative and electrophilic capacity of aerosols, and point out the need for inclusion of vapors in future health and risk assessment studies. PMID:20152964
15. Characterization of new particle and secondary aerosol formation during summertime in Beijing, China
Zhang, Y. M.; Zhang, X. Y.; Sun, J. Y.; Lin, W. L.; Gong, S. L.; Shen, X. J.; Yang, S.
2011-07-01
Size-resolved aerosol number and mass concentrations and the mixing ratios of O3 and various trace gases were continuously measured at an urban station before and during the Beijing Olympic and Paralympic Games (5 June to 22 September, 2008). 23 new particle formation (NPF) events were identified; these usually were associated with changes in wind direction and/or rising concentrations of gas-phase precursors or after precipitation events. Most of the NPF events started in the morning and continued to noon as particles in the nucleation mode grew into the Aitken mode. From noon to midnight, the aerosols grew into the accumulation mode through condensation and coagulation. Ozone showed a gradual rise starting around 10:00 local time, reached its peak around 15:00 and then declined as the organics increased. The dominant new particle species were organics (40-75% of PM1) and sulphate; nitrate and ammonium were more minor contributors.
16. Kinetic analysis of competition between aerosol particle removal and generation by ionization air purifiers.
PubMed
Alshawa, Ahmad; Russell, Ashley R; Nizkorodov, Sergey A
2007-04-01
Ionization air purifiers are increasingly used to remove aerosol particles from indoor air. However, certain ionization air purifiers also emit ozone. Reactions between the emitted ozone and unsaturated volatile organic compounds (VOC) commonly found in indoor air produce additional respirable aerosol particles in the ultrafine (<0.1 microm) and fine (<2.5 microm) size domains. A simple kinetic model is used to analyze the competition between the removal and generation of particulate matter by ionization air purifiers under conditions of a typical residential building. This model predicts that certain widely used ionization air purifiers may actually increase the mass concentration of fine and ultrafine particulates in the presence of common unsaturated VOC, such as limonene contained in many household cleaning products. This prediction is supported by an explicit observation of ultrafine particle nucleation events caused by the addition of D-limonene to a ventilated office room equipped with a common ionization air purifier.
17. Aerosol-fluorescence spectrum analyzer: real-time measurement of emission spectra of airborne biological particles
Hill, Steven C.; Pinnick, Ronald G.; Nachman, Paul; Chen, Gang; Chang, Richard K.; Mayo, Michael W.; Fernandez, Gilbert L.
1995-10-01
We have assembled an aerosol-fluorescence spectrum analyzer (AFS), which can measure the fluorescence spectra and elastic scattering of airborne particles as they flow through a laser beam. The aerosols traverse a scattering cell where they are illuminated with intense (50 kW/cm 2) light inside the cavity of an argon-ion laser operating at 488 nm. This AFS can obtain fluorescence spectra of individual dye-doped polystyrene microspheres as small as 0.5 mu m in diameter. The spectra obtained from microspheres doped with pink and green-yellow dyes are clearly different. We have also detected the fluorescence spectra of airborne particles (although not single particles) made from various
18. Optical Properties of Internally Mixed Aerosol Particles Composed of Dicarboxylic Acids and Ammonium Sulfate
Freedman, Miriam A.; Hasenkopf, Christa A.; Beaver, Melinda R.; Tolbert, Margaret A.
2009-10-01
We have investigated the optical properties of internally mixed aerosol particles composed of dicarboxylic acids and ammonium sulfate using cavity ring-down aerosol extinction spectroscopy at a wavelength of 532 nm. The real refractive indices of these nonabsorbing species were retrieved from the extinction and concentration of the particles using Mie scattering theory. We obtain refractive indices for pure ammonium sulfate and pure dicarboxylic acids that are consistent with literature values, where they exist, to within experimental error. For mixed particles, however, our data deviates significantly from a volume-weighted average of the pure components. Surprisingly, the real refractive indices of internal mixtures of succinic acid and ammonium sulfate are higher than either of the pure components at the highest organic weight fractions. For binary internal mixtures of oxalic or adipic acid with ammonium sulfate, the real refractive indices of the mixtures are approximately the same as ammonium sulfate for all organic weight fractions. Various optical mixing rules for homogeneous and slightly heterogeneous systems fail to explain the experimental real refractive indices. It is likely that complex particle morphologies are responsible for the observed behavior of the mixed particles. Implications of our results for atmospheric modeling and aerosol structure are discussed.
19. Cloud droplet activation through oxidation of organic aerosol influenced by temperature and particle phase state
DOE PAGES
Slade, Jonathan H.; Shiraiwa, Manabu; Arangio, Andrea; ...
2017-01-27
Chemical aging of organic aerosol (OA) through multiphase oxidation reactions can alter their cloud condensation nuclei (CCN) activity and hygroscopicity. However, the oxidation kinetics and OA reactivity depend strongly on the particle phase state, potentially influencing the hydrophobic-to-hydrophilic conversion rate of carbonaceous aerosol. Here, amorphous Suwannee River fulvic acid (SRFA) aerosol particles, a surrogate humic-like substance (HULIS) that contributes substantially to global OA mass, are oxidized by OH radicals at different temperatures and phase states. When oxidized at low temperature in a glassy solid state, the hygroscopicity of SRFA particles increased by almost a factor of two, whereas oxidation ofmore » liquid-like SRFA particles at higher temperatures did not affect CCN activity. Low-temperature oxidation appears to promote the formation of highly-oxygenated particle-bound fragmentation products with lower molar mass and greater CCN activity, underscoring the importance of chemical aging in the free troposphere and its influence on the CCN activity of OA.« less
20. The influence of small aerosol particles on the properties of water and ice clouds.
PubMed
Choularton, T W; Bower, K N; Weingartner, E; Crawford, I; Coe, H; Gallagher, M W; Flynn, M; Crosier, J; Connolly, P; Targino, A; Alfarra, M R; Baltensperger, U; Sjogren, S; Verheggen, B; Cozic, J; Gysel, M
2008-01-01
In this paper, results are presented of the influence of small organic- and soot-containing particles on the formation of water and ice clouds. There is strong evidence that these particles have grown from nano particle seeds produced by the combustion of oil products. Two series of field experiments are selected to represent the observations made. The first is the CLoud-Aerosol Characterisation Experiment (CLACE) series of experiments performed at a high Alpine site (Jungfraujoch), where cloud was in contact with the ground and the measuring station. Both water and ice clouds were examined at different times of the year. The second series of experiments is the CLOud Processing of regional Air Pollution advecting over land and sea (CLOPAP) series, where ageing pollution aerosol from UK cities was observed, from an airborne platform, to interact with warm stratocumulus cloud in a cloud-capped atmospheric boundary layer. Combining the results it is shown that aged pollution aerosol consists of an internal mixture of organics, sulfate, nitrate and ammonium, the organic component is dominated by highly oxidized secondary material. The relative contributions and absolute loadings of the components vary with location and season. However, these aerosols act as Cloud Condensation Nuclei (CCN) and much of the organic material, along with the other species, is incorporated into cloud droplets. In ice and mixed phase cloud, it is observed that very sharp transitions (extending over just a few metres) are present between highly glaciated regions and regions consisting of supercooled water. This is a unique finding; however, aircraft observations in cumulus suggest that this kind of structure may be found in these cloud types too. It is suggested that this sharp transition is caused by ice nucleation initiated by oxidised organic aerosol coated with sulfate in more polluted regions of cloud, sometimes enhanced by secondary ice particle production in these regions.
1. Differences in physical chemistry and dissolution rate of solid particle aerosols from solution pressurised inhalers.
PubMed
Buttini, Francesca; Miozzi, Michele; Balducci, Anna Giulia; Royall, Paul G; Brambilla, Gaetano; Colombo, Paolo; Bettini, Ruggero; Forbes, Ben
2014-04-25
Solution composition alters the dynamics of beclomethasone diproprionate (BDP) particle formation from droplets emitted by pressurised metered dose inhalers (pMDIs). The hypothesis that differences in inhaler solutions result in different solid particle physical chemistry was tested using a suite of complementary calorimetric techniques. The atomisation of BDP-ethanol solutions from commercial HFA-pMDI produced aerodynamically-equivalent solid particle aerosols. However, differences in particle physico-chemistry (morphology and solvate/clathrate formation) were detected by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and supported by hot stage microscopy (HSM). Increasing the ethanol content of the formulation from 8 to 12% (w/w), which retards the evaporation of propellant and slows the increase in droplet surface viscosity, enhanced the likelihood of particles drying with a smooth surface. The dissolution rate of BDP from the 12% (w/w) ethanol formulation-derived particles (63% dissolved over 120 min) was reduced compared to the 8% (w/w) ethanol formulation-derived particles (86% dissolved over 120 min). The addition of 0.01% (w/w) formoterol fumarate or 1.3% (w/w) glycerol to the inhaler solution modified the particles and reduced the BDP dissolution rate further to 34% and 16% dissolved in 120 min, respectively. These data provide evidence that therapeutic aerosols from apparently similar inhaler products, including those with similar aerodynamic performance, may behave non-equivalently after deposition in the lungs.
2. Extractive Electrospray Ionization Mass Spectrometry of Heterogeneous Particles: Implications for Applications to Complex Atmospheric Aerosol
Longin, T.; Waring-Kidd, C.; Wingen, L. M.; Lyster, K.; Anderson, C.; Kumbhani, S.; Finlayson-Pitts, B. J.
2015-12-01
Extractive electrospray ionization mass spectrometry (EESI-MS) is a direct, real time technique for obtaining mass spectra of gases, liquid droplets, solid particles, and aerosols with little sample processing. EESI-MS involves the interaction of charged electrospray droplets with a separate spray containing the analyte of interest, but the exact mechanism by which the solvent droplets extract analyte from the sample is unclear. Possible mechanisms include complete coalescence of the sample particle with the solvent droplet in which all of the analyte is incorporated into the solvent or a more temporary interaction such that only some of the analyte is transferred to the solvent. Previous studies of the mechanism of EESI-MS on homogeneous particles indicate that both mechanisms are possible. We studied the behavior of EESI-MS toward heterogeneous particles created by coating NaCl particles with various thicknesses of organic diacids. Our results indicate that the signal strength depends on the solubility of the organic acid in the electrospray solvent, in agreement with previous studies, and also that the outer 10-15 nm of the particles are most susceptible to extraction into the electrospray droplets. Our results combined with those of previous studies suggest that the mass spectra obtained with EESI will not necessarily reflect the overall particle composition, especially for particles that are spatially inhomogeneous, and hence caution in interpretation of the data is advised for application to complex atmospheric aerosol.
3. The ice nucleation activity of biological aerosols
Grothe, H.; Pummer, B.; Bauer, H.; Bernardi, J.
2012-04-01
Primary Biological Aerosol Particles (PBAPs), including bacteria, spores and pollen may be important for several atmospheric processes. Particularly, the ice nucleation caused by PBAPs is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate is not yet fully understood. In laboratory model studies we investigated the ice nucleation activity of selected PBAPs. We studied the immersion mode freezing using water-oil emulsion, which we observed by optical microscopy. We particularly focused on pollen. We show that pollen of different species strongly differ in their ice nucleation behavior. The average freezing temperatures in laboratory experiments range from 240 K to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen) have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. For comparison the ice nucleation activity of Snomax, fungal spores, and mushrooms will be discussed as well. In the past, pollen have been rejected as important atmospheric IN, as they are not as abundant in the atmosphere as bacteria or mineral dust and are too heavy to reach higher altitudes. However, in our experiments (Pummer et al. 2011) it turned out that water, which had been in contact with pollen and then been separated from the bodies, nucleates as good as the pollen grains themselves. So the ice nuclei have to be easily-suspendable macromolecules (100-300 kDa) located on the pollen. Once extracted, they can be distributed further through the atmosphere than the heavy pollen grains and so augment the impact of pollen on ice cloud formation even in the upper troposphere. It is widely known, that material from the pollen, like allergens and sugars, can indeed leave the pollen body and be distributed independently. The most probable mechanism is the pollen grain bursting by rain, which releases
4. Effect of aerosol particles generated by ultrasonic humidifiers on the lung in mouse
PubMed Central
2013-01-01
Background Ultrasonic humidifiers silently generate water droplets as a cool fog and produce most of the dissolved minerals in the fog in the form of an aerosolized “white dust.” However, the health effect of these airborne particles is largely unknown. This study aimed to characterize the aerosol particles generated by ultrasonic humidifiers and to investigate their effect on the lung tissue of mice. Methods An ultrasonic humidifier was operated with tap water, high-silica water, ultrapure water, or other water types. In a chamber (0.765 m3, ventilation ratio 11.5 m3/hr), male ICR mice (10-week-old) were exposed by inhalation to an aerosol-containing vapor generated by the humidifier. After exposure for 7 or 14 days, lung tissues and bronchoalveolar lavage fluid (BALF) were collected from each mouse and examined by microarray, quantitative reverse transcription-polymerase chain reaction, and light and electron microscopy. Results Particles generated from the humidifier operated with tap water had a mass concentration of 0.46 ± 0.03 mg/m3, number concentration of (5.0 ± 1.1) × 104/cm3, and peak size distribution of 183 nm. The particles were phagocytosed by alveolar macrophages in the lung of mice. Inhalation of particles caused dysregulation of genes related to mitosis, cell adhesion molecules, MHC molecules and endocytosis, but did not induce any signs of inflammation or tissue injury in the lung. Conclusion These results indicate that aerosol particles released from ultrasonic humidifiers operated with tap water initiated a cellular response but did not cause severe acute inflammation in pulmonary tissue. Additionally, high mineral content tap water is not recommended and de-mineralized water should be recommended in order to exclude any adverse effects. PMID:24359587
5. Chemical compositions of black carbon particle cores and coatings via soot particle aerosol mass spectrometry with photoionization and electron ionization.
PubMed
Canagaratna, Manjula R; Massoli, Paola; Browne, Eleanor C; Franklin, Jonathan P; Wilson, Kevin R; Onasch, Timothy B; Kirchstetter, Thomas W; Fortner, Edward C; Kolb, Charles E; Jayne, John T; Kroll, Jesse H; Worsnop, Douglas R
2015-05-14
Black carbon is an important constituent of atmospheric aerosol particle matter (PM) with significant effects on the global radiation budget and on human health. The soot particle aerosol mass spectrometer (SP-AMS) has been developed and deployed for real-time ambient measurements of refractory carbon particles. In the SP-AMS, black carbon or metallic particles are vaporized through absorption of 1064 nm light from a CW Nd:YAG laser. This scheme allows for continuous "soft" vaporization of both core and coating materials. The main focus of this work is to characterize the extent to which this vaporization scheme provides enhanced chemical composition information about aerosol particles. This information is difficult to extract from standard SP-AMS mass spectra because they are complicated by extensive fragmentation from the harsh 70 eV EI ionization scheme that is typically used in these instruments. Thus, in this work synchotron-generated vacuum ultraviolet (VUV) light in the 8-14 eV range is used to measure VUV-SP-AMS spectra with minimal fragmentation. VUV-SP-AMS spectra of commercially available carbon black, fullerene black, and laboratory generated flame soots were obtained. Small carbon cluster cations (C(+)-C5(+)) were found to dominate the VUV-SP-AMS spectra of all the samples, indicating that the corresponding neutral clusters are key products of the SP vaporization process. Intercomparisons of carbon cluster ratios observed in VUV-SP-AMS and SP-AMS spectra are used to confirm spectral features that could be used to distinguish between different types of refractory carbon particles. VUV-SP-AMS spectra of oxidized organic species adsorbed on absorbing cores are also examined and found to display less thermally induced decomposition and fragmentation than spectra obtained with thermal vaporization at 200 °C (the minimum temperature needed to quantitatively vaporize ambient oxidized organic aerosol with a continuously heated surface). The particle cores
6. Detection of cw-related species in complex aerosol particles deposited on surfaces with an ion trap-based aerosol mass spectrometer
SciTech Connect
Harris, William A; Reilly, Pete; Whitten, William B
2007-01-01
A new type of aerosol mass spectrometer was developed by minimal modification of an existing commercial ion trap to analyze the semivolatile components of aerosols in real time. An aerodynamic lens-based inlet system created a well-collimated particle beam that impacted into the heated ionization volume of the commercial ion trap mass spectrometer. The semivolatile components of the aerosols were thermally vaporized and ionized by electron impact or chemical ionization in the source. The nascent ions were extracted and injected into the ion trap for mass analysis. The utility of this instrument was demonstrated by identifying semivolatile analytes in complex aerosols. This study is part of an ongoing effort to develop methods for identifying chemical species related to CW agent exposure. Our efforts focused on detection of CW-related species doped on omnipresent aerosols such as house dust particles vacuumed from various surfaces found in any office building. The doped aerosols were sampled directly into the inlet of our mass spectrometer from the vacuumed particle stream. The semivolatile analytes were deposited on house dust and identified by positive ion chemical ionization mass spectrometry up to 2.5 h after deposition. Our results suggest that the observed semivolatile species may have been chemisorbed on some of the particle surfaces in submonolayer concentrations and may remain hours after deposition. This research suggests that identification of trace CW agent-related species should be feasible by this technique.
7. Time evolution and emission factors of aerosol particles from day and night time savannah fires
Vakkari, Ville; Beukes, Johan Paul; Tiitta, Petri; Venter, Andrew; Jaars, Kerneels; Josipovic, Miroslav; van Zyl, Pieter; Kulmala, Markku; Laakso, Lauri
2013-04-01
The largest uncertainties in the current global climate models originate from aerosol particle effects (IPCC, 2007) and at the same time aerosol particles also pose a threat to human health (Pope and Dockery, 2006). In southern Africa wild fires and prescribed burning are one of the most important sources of aerosol particles, especially during the dry season from June to September (e.g. Swap et al., 2003; Vakkari et al., 2012). The aerosol particle emissions from savannah fires in southern Africa have been studied in several intensive campaigns such as SAFARI 1992 and 2000 (Swap et al., 2003). However, all previous measurements have been carried out during the daytime, whereas most of the prescribed fires in southern Africa are lit up only after sunset. Furthermore, the previous campaigns followed the plume evolution for up to one hour after emission only. In this study, combining remote sensing fire observations to ground-based long-term measurements of aerosol particle and trace gas properties at the Welgegund measurement station (www.welgegund.org), we have been able to follow the time evolution of savannah fire plumes up to several hours in the atmosphere. For the first time the aerosol particle size distribution measurements in savannah fire plumes cover both day and night time plumes and also the ultrafine size range below 100 nm. During the period from May 20th 2010 to April 15th 2012 altogether 61 savannah fire plumes were observed at Welgegund. The evolution of the aerosol size distribution remained rapid for at least five hours after the fire: during this period the growth rate of the aerosol particle count mean diameter (size range 12 to 840 nm) was 24 nm h-1 for daytime plumes and 8 nm h-1 for night time plumes. The difference in the day and night time growth rate shows that photochemical reactions significantly increase the condensable vapour concentration in the plume. Furthermore, the condensable vapour concentration was found to affect both the
8. Electron Microscopy and Raman Microspectroscopy as Characterization Tools and Probes of the Chemistry and Properties of Individual Aerosol Particles
Grassian, V. H.
2012-12-01
Microscopic probes provide useful insights into the physicochemical properties of aerosol particles and their environmental and health effects. The focus of this talk is on the use of microscopic probes in a wide-range of laboratory studies to better understand the physicochemical properties (chemical heterogeneity, morphology, water uptake, infrared extinction and heterogeneous reactivity) of individual atmospheric aerosol particles. Microscopy coupled to energy dispersive X-ray analysis is used in these studies to characterize particles in terms of size and shape as individual particles or as aggregates particles as well as to follow chemical and physical transformations of particles as they undergo reactions under different environmental conditions. Raman microspectroscopy provides additional chemical specific information and the internal mixing of chemical constituents within individual particles. Several examples will be discussed for flyash, mineral dust and sea spray aerosol particles.
9. PD-FiTE - an efficient method for calculating gas / liquid equilibria in atmospheric aerosol particles
Topping, D.; Lowe, D.; McFiggans, G.; Barley, M.
2009-04-01
Assessing the impact of atmospheric aerosol particles on the environment requires adequate representation of appropriate key processes within large scale models. In the absence of primary particulate material, interactions between the atmospheric gaseous components and particles means that the chemical nature of the particles is largely determined by the availability of condensable gaseous material, such as sulphuric and nitric acids, and by the ambient environmental conditions. Gas to particle mass transfer of semi-volatile components,driven by a difference in equilibrium and actual partial pressures above an aerosol particle, is an important factor in determining the evolving chemical composition of the particle and is necessary for predicting aerosol loading and composition. The design of an appropriate framework required for parameterizations of key variables is challenging. These thermodynamic frameworks are often numerically very complex, resulting in significant computational expense. Three dimensional chemical and aerosol transport models demand that computational expense be kept at a minimum,resulting in a trade-off between accuracy and efficiency. To calculate the equilibrium vapour pressure above a solution requires treatment of solution nonideality. This is manifest through activity coefficients of components pertinent to each condensing specie. However, activity coefficients are complex functions of the solution composition. Parameterisation of activity coefficients provides the main focus of this work largely because reducing the numerical complexity whilst retaining a good level of accuracy is very challenging. The approach presented here, the hybrid Partial Derivative Fitted Taylor Expansion (PDFiTE) (Topping et al 2008), builds on previously reported work, with an aim to derive parameters for an accurate and computationally efficient framework through coupling with a complex thermodynamic model. Such a reduction in complexity is important as it is
10. Influence of particle phase state on the hygroscopic behavior of mixed organic-inorganic aerosols
Hodas, N.; Zuend, A.; Mui, W.; Flagan, R. C.; Seinfeld, J. H.
2014-12-01
Recent work has demonstrated that organic and mixed organic-inorganic particles can exhibit multiple phase states depending on their chemical composition and on ambient conditions such as relative humidity (RH). To explore the extent to which water uptake varies with particle phase behavior, hygroscopic growth factors (HGFs) of nine laboratory-generated, organic and organic-inorganic aerosol systems with physical states ranging from well-mixed liquids, to phase-separated particles, to viscous liquids or semi-solids were measured with the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe at RH values ranging from 40-90%. Water-uptake measurements were accompanied by HGF and RH-dependent thermodynamic equilibrium calculations using the Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model. In addition, AIOMFAC-predicted growth curves are compared to several simplified HGF modeling approaches: (1) representing particles as ideal, well-mixed liquids, (2) forcing a single phase, but accounting for non-ideal interactions through activity coefficient calculations, and (3) a Zdanovskii-Stokes-Robinson-like calculation in which complete separation between the inorganic and organic components is assumed at all RH values, with water-uptake treated separately in each of the individual phases. We observed variability in the characteristics of measured hygroscopic growth curves across aerosol systems with differing phase behaviors, with growth curves approaching smoother, more continuous water uptake with decreasing prevalence of liquid-liquid phase separation and increasing oxygen : carbon ratios of the organic aerosol components. We also observed indirect evidence for the dehydration-induced formation of highly viscous semi-solid phases and for kinetic limitations to the crystallization of ammonium sulfate at low RH for sucrose-containing particles. AIOMFAC-predicted growth curves are generally in good agreement with the HGF
11. Influence of particle-phase state on the hygroscopic behavior of mixed organic-inorganic aerosols
Hodas, N.; Zuend, A.; Mui, W.; Flagan, R. C.; Seinfeld, J. H.
2015-05-01
Recent work has demonstrated that organic and mixed organic-inorganic particles can exhibit multiple phase states depending on their chemical composition and on ambient conditions such as relative humidity (RH). To explore the extent to which water uptake varies with particle-phase behavior, hygroscopic growth factors (HGFs) of nine laboratory-generated, organic and organic-inorganic aerosol systems with physical states ranging from well-mixed liquids to phase-separated particles to viscous liquids or semi-solids were measured with the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe at RH values ranging from 40 to 90%. Water-uptake measurements were accompanied by HGF and RH-dependent thermodynamic equilibrium calculations using the Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model. In addition, AIOMFAC-predicted growth curves are compared to several simplified HGF modeling approaches: (1) representing particles as ideal, well-mixed liquids; (2) forcing a single phase but accounting for non-ideal interactions through activity coefficient calculations; and (3) a Zdanovskii-Stokes-Robinson-like calculation in which complete separation of the inorganic and organic components is assumed at all RH values, with water uptake treated separately in each of the individual phases. We observed variability in the characteristics of measured hygroscopic growth curves across aerosol systems with differing phase behaviors, with growth curves approaching smoother, more continuous water uptake with decreasing prevalence of liquid-liquid phase separation and increasing oxygen : carbon ratios of the organic aerosol components. We also observed indirect evidence for the dehydration-induced formation of highly viscous semi-solid phases and for kinetic limitations to the crystallization of ammonium sulfate at low RH for sucrose-containing particles. AIOMFAC-predicted growth curves are generally in good agreement with the HGF
12. Early growth dynamical implications for the steerability of stratospheric solar radiation management via sulfur aerosol particles
Benduhn, François; Schallock, Jennifer; Lawrence, Mark G.
2016-09-01
Aerosol growth dynamics may have implications for the steerability of stratospheric solar radiation management via sulfur particles. This paper derives a set of critical initial growth conditions that are analyzed as a function of two key parameters: the initial concentration of the injected sulfuric acid and its dilution rate with the surrounding air. Based upon this analysis, early aerosol growth dynamical regimes may be defined and classified in terms of their likelihood to serve as candidates for the controlled generation of a radiatively effective aerosol. Our results indicate that the regime that fulfills all critical conditions would require that airplane turbines be used to provide sufficient turbulence. The regime's parameter space is narrow and related to steep gradients, thus pointing to potential fine tuning requirements. More research, development, and testing would be required to refine our findings and determine their global-scale implications.
13. Aerosol mass spectrometry: particle-vaporizer interactions and their consequences for the measurements
Drewnick, F.; Diesch, J.-M.; Faber, P.; Borrmann, S.
2015-09-01
The Aerodyne aerosol mass spectrometer (AMS) is a frequently used instrument for on-line measurement of the ambient sub-micron aerosol composition. With the help of calibrations and a number of assumptions on the flash vaporization and electron impact ionization processes, this instrument provides robust quantitative information on various non-refractory ambient aerosol components. However, when measuring close to certain anthropogenic or marine sources of semi-refractory aerosols, several of these assumptions may not be met and measurement results might easily be incorrectly interpreted if not carefully analyzed for unique ions, isotope patterns, and potential slow vaporization associated with semi-refractory species. Here we discuss various aspects of the interaction of aerosol particles with the AMS tungsten vaporizer and the consequences for the measurement results: semi-refractory components - i.e., components that vaporize but do not flash-vaporize at the vaporizer and ionizer temperatures, like metal halides (e.g., chlorides, bromides or iodides of Al, Ba, Cd, Cu, Fe, Hg, K, Na, Pb, Sr, Zn) - can be measured semi-quantitatively despite their relatively slow vaporization from the vaporizer. Even though non-refractory components (e.g., NH4NO3 or (NH4)2SO4) vaporize quickly, under certain conditions their differences in vaporization kinetics can result in undesired biases in ion collection efficiency in thresholded measurements. Chemical reactions with oxygen from the aerosol flow can have an influence on the mass spectra for certain components (e.g., organic species). Finally, chemical reactions of the aerosol with the vaporizer surface can result in additional signals in the mass spectra (e.g., WO2Cl2-related signals from particulate Cl) and in conditioning or contamination of the vaporizer, with potential memory effects influencing the mass spectra of subsequent measurements. Laboratory experiments that investigate these particle-vaporizer interactions are
14. Developing a new parameterization framework for the heterogeneous ice nucleation of atmospheric aerosol particles
Ullrich, Romy; Hiranuma, Naruki; Hoose, Corinna; Möhler, Ottmar; Niemand, Monika; Steinke, Isabelle; Wagner, Robert
2014-05-01
Developing a new parameterization framework for the heterogeneous ice nucleation of atmospheric aerosol particles Ullrich, R., Hiranuma, N., Hoose, C., Möhler, O., Niemand, M., Steinke, I., Wagner, R. Aerosols of different nature induce microphysical processes of importance for the Earth's atmosphere. They affect not only directly the radiative budget, more importantly they essentially influence the formation and life cycles of clouds. Hence, aerosols and their ice nucleating ability are a fundamental input parameter for weather and climate models. During the previous years, the AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber was used to extensively measure, under nearly realistic conditions, the ice nucleating properties of different aerosols. Numerous experiments were performed with a broad variety of aerosol types and under different freezing conditions. A reanalysis of these experiments offers the opportunity to develop a uniform parameterization framework of ice formation for many atmospherically relevant aerosols in a broad temperature and humidity range. The analysis includes both deposition nucleation and immersion freezing. The aim of this study is to develop this comprehensive parameterization for heterogeneous ice formation mainly by using the ice nucleation active site (INAS) approach. Niemand et al. (2012) already developed a temperature dependent parameterization for the INAS- density for immersion freezing on desert dust particles. In addition to a reanalysis of the ice nucleation behaviour of desert dust (Niemand et al. (2012)), volcanic ash (Steinke et al. (2010)) and organic particles (Wagner et al. (2010,2011)) this contribution will also show new results for the immersion freezing and deposition nucleation of soot aerosols. The next step will be the implementation of the parameterizations into the COSMO- ART model in order to test and demonstrate the usability of the framework. Hoose, C. and Möhler, O. (2012) Atmos
15. Source contributions to black carbon mass fractions in aerosol particles over the northwestern Pacific
Koga, Seizi; Maeda, Takahisa; Kaneyasu, Naoki
Aerosol particle number size distributions above 0.3 μm in diameter and black carbon mass concentrations in aerosols were observed on Chichi-jima of the Ogasawara Islands in the northwestern Pacific from January 2000 to December 2002. Chichi-jima is suitable to observe polluted air masses from East Asia in winter and clean air masses over the western North Pacific in summer. In winter, aerosols over Chichi-jima were strongly affected by anthropogenic emissions in East Asia. The form of energy consumption in East Asia varies in various regions. Hence, each source region is expected to be characterized by an individual black carbon mass fraction. A three-dimensional Eulerian transport model was used to estimate contribution rates to air pollutants from each source region in East Asia. Because the Miyake-jima eruption began at the end of June 2000, the influence of smokes from Miyake-jima was also considered in the model calculation. The results of model calculations represent what must be noticed about smokes from volcanoes including Miyake-jima to interpret temporal variations of sulfur compounds over the northwestern Pacific. To evaluate black carbon mass fractions in anthropogenic aerosols as a function of source region, the relationships between the volume concentration of aerosol particles and the black carbon mass concentration in the winter were classified under each source region in East Asia. Consequently, the black carbon mass fractions in aerosols from China, Japan and the Korean Peninsula, and other regions were estimated to be 9-13%, 5-7%, and 4-5%, respectively.
16. A role of aerosol particles in forming urban skyglow and skyglow from distant cities
2016-05-01
Aerosol particles may represent the largest uncertainty about skyglow change in many locations under clear-sky conditions. This is because aerosols are ubiquitous in the atmosphere and influence the ground-reaching radiation in different ways depending on their concentrations, origins, shapes, sizes, and compositions. Large particles tend to scatter in Fraunhofer diffraction regime, while small particles can be treated in terms of Rayleigh formalism. However, the role of particle microphysics in forming the skyglow still remains poorly quantified. We have shown in this paper that the chemistry is somehow important for backscattering from large particles that otherwise work as efficient attenuators of light pollution if composed of absorbing materials. The contribution of large particles to the urban skyglow diminishes as they become more spherical in shape. The intensity of backscattering from non-absorbing particles is more-or-less linearly decreasing function of particle radius even if number size distribution is inversely proportional to the fourth power of particle radius. This is due to single particle backscattering that generally increases steeply as the particle radius approaches large values. Forward scattering depends on the particle shape but is independent of the material composition, thus allowing for a simplistic analytical model of skyglow from distant cities. The model we have developed is based on mean value theorem for integrals and incorporates the parametrizable Garstang's emission pattern, intensity decay along optical beam path, and near-forward scattering in an atmospheric environment. Such model can be used by modellers and experimentalists for rapid estimation of skyglow from distant light sources.
17. Microphysical aerosol parameters of spheroidal particles via regularized inversion of lidar data
Samaras, Stefanos; Böckmann, Christine
2015-04-01
One of the main topics in understanding the aerosol impact on climate requires the investigation of the spatial and temporal variability of microphysical properties of particles, e.g., the complex refractive index, the effective radius, the volume and surface-area concentration, and the single-scattering albedo. Remote sensing is a technique used to monitor aerosols in global coverage and fill in the observational gap. This research topic involves using multi-wavelength Raman lidar systems to extract the microphysical properties of aerosol particles, along with depolarization signals to account for the non-sphericity of the latter. Given, the optical parameters (measured by a lidar), the kernel functions, which summarize the size, shape and composition of particles, we solve for the size distribution of the particles modeled by a Fredholm integral system and further calculate the refractive index. This model works well for spherical particles (e.g. smoke); the kernel functions are derived from relatively simplified formulas (Mie scattering theory) and research has led to successful retrievals for particles which at least resemble a spherical geometry (small depolarization ratio). Obviously, more complicated atmospheric structures (e.g dust) require employment of non-spherical kernels and/or more complicated models which are investigated in this paper. The new model is now a two-dimensional one including the aspect ratio of spheroidal particles. The spheroidal kernel functions are able to be calculated via T-Matrix; a technique used for computing electromagnetic scattering by single, homogeneous, arbitrarily shaped particles. In order to speed up the process and massively perform simulation tests, we created a software interface using different regularization methods and parameter choice rules. The following methods have been used: Truncated singular value decomposition and Pade iteration with the discrepancy principle, and Tikhonov regularization with the L
18. Chemical Imaging of Ambient Aerosol Particles: Observational Constraints on Mixing State Parameterization
SciTech Connect
O'Brien, Rachel; Wang, Bingbing; Laskin, Alexander; Riemer, Nicole; West, Matthew; Zhang, Qi; Sun, Yele; Yu, Xiao-Ying; Alpert, Peter A.; Knopf, Daniel A.; Gilles, Mary K.; Moffet, Ryan
2015-09-28
A new parameterization for quantifying the mixing state of aerosol populations has been applied for the first time to samples of ambient particles analyzed using spectro-microscopy techniques. Scanning transmission x-ray microscopy/near edge x-ray absorption fine structure (STXM/NEXAFS) and computer controlled scanning electron microscopy/energy dispersive x-ray spectroscopy (CCSEM/EDX) were used to probe the composition of the organic and inorganic fraction of individual particles collected on June 27th and 28th during the 2010 Carbonaceous Aerosols and Radiative Effects (CARES) study in the Central Valley, California. The first field site, T0, was located in downtown Sacramento, while T1 was located near the Sierra Nevada Mountains. Mass estimates of the aerosol particle components were used to calculate mixing state metrics, such as the particle-specific diversity, bulk population diversity, and mixing state index, for each sample. Both microscopy imaging techniques showed more changes over these two days in the mixing state at the T0 site than at the T1 site. The STXM data showed evidence of changes in the mixing state associated with a build-up of organic matter confirmed by collocated measurements and the largest impact on the mixing state was due to an increase in soot dominant particles during this build-up. The CCSEM/EDX analysis showed the presence of two types of particle populations; the first was dominated by aged sea salt particles and had a higher mixing state index (indicating a more homogeneous population), the second was dominated by carbonaceous particles and had a lower mixing state index.
19. Chemical imaging of ambient aerosol particles: Observational constraints on mixing state parameterization
DOE PAGES
O'Brien, Rachel E.; Wang, Bingbing; Laskin, Alexander; ...
2015-08-26
In this study, a new parameterization for quantifying the mixing state of aerosol populations has been applied for the first time to samples of ambient particles analyzed using spectro-microscopy techniques. Scanning transmission X-ray microscopy/near edge X-ray absorption fine structure (STXM/NEXAFS) and computer-controlled scanning electron microscopy/energy dispersive X-ray spectroscopy (CCSEM/EDX) were used to probe the composition of the organic and inorganic fraction of individual particles collected on 27 and 28 June during the 2010 Carbonaceous Aerosols and Radiative Effects study in the Central Valley, California. The first field site, T0, was located in downtown Sacramento, while T1 was located near themore » Sierra Nevada Mountains. Mass estimates of the aerosol particle components were used to calculate mixing state metrics, such as the particle-specific diversity, bulk population diversity, and mixing state index, for each sample. The STXM data showed evidence of changes in the mixing state associated with a buildup of organic matter confirmed by collocated measurements, and the largest impact on the mixing state was due to an increase in soot dominant particles during this buildup. The mixing state from STXM was similar between T0 and T1, indicating that the increased organic fraction at T1 had a small effect on the mixing state of the population. The CCSEM/EDX analysis showed the presence of two types of particle populations: the first was dominated by aged sea-salt particles and had a higher mixing state index (indicating a more homogeneous population); the second was dominated by carbonaceous particles and had a lower mixing state index.« less
20. Chemical imaging of ambient aerosol particles: Observational constraints on mixing state parameterization
SciTech Connect
O'Brien, Rachel E.; Wang, Bingbing; Laskin, Alexander; Riemer, Nicole; West, Matthew; Zhang, Qi; Sun, Yele; Yu, Xiao -Ying; Alpert, Peter; Knopf, Daniel A.; Gilles, Mary K.; Moffet, Ryan C.
2015-08-26
In this study, a new parameterization for quantifying the mixing state of aerosol populations has been applied for the first time to samples of ambient particles analyzed using spectro-microscopy techniques. Scanning transmission X-ray microscopy/near edge X-ray absorption fine structure (STXM/NEXAFS) and computer-controlled scanning electron microscopy/energy dispersive X-ray spectroscopy (CCSEM/EDX) were used to probe the composition of the organic and inorganic fraction of individual particles collected on 27 and 28 June during the 2010 Carbonaceous Aerosols and Radiative Effects study in the Central Valley, California. The first field site, T0, was located in downtown Sacramento, while T1 was located near the Sierra Nevada Mountains. Mass estimates of the aerosol particle components were used to calculate mixing state metrics, such as the particle-specific diversity, bulk population diversity, and mixing state index, for each sample. The STXM data showed evidence of changes in the mixing state associated with a buildup of organic matter confirmed by collocated measurements, and the largest impact on the mixing state was due to an increase in soot dominant particles during this buildup. The mixing state from STXM was similar between T0 and T1, indicating that the increased organic fraction at T1 had a small effect on the mixing state of the population. The CCSEM/EDX analysis showed the presence of two types of particle populations: the first was dominated by aged sea-salt particles and had a higher mixing state index (indicating a more homogeneous population); the second was dominated by carbonaceous particles and had a lower mixing state index.
1. Transmission Electron Microscopy Analysis of Submicronic Aerosol Particles Sampled at Jungfraujoch, Switzerland (CLACE-4)
Grobéty, B.; Lorenzo, R.
2007-05-01
Submicronic aerosol particles were collected in two sampling campaigns during CLACE-4 and -5 ("the Cloud and Aerosol Characterisation Experiment in the Free Troposphere") at the high alpine research station on top of Jungfraujoch (altitude: 3580 m.a.s.l.). The particles were deposited directly on transmission electron microscopy (TEM) grids placed in a home-made, calibrated thermophoretic sampling device. The samples were taken during periods of clear skies and temperatures below 0°C. Average sampling time was two days. The primary state of the particles was either solid, mixed solid-liquid or completely liquid. EDS spectra of solid particles without visible traces of a liquid coating contain only carbon and oxygen peaks. Mixed solid-fluid particles, however, have either carbon (C), mixed carbon-silicate (CS) or silicate (S) (probably SiO2) nuclei. The condensates remaining after evaporation of the liquid components contain sulfate (sulfur and oxygen peaks in EDS spectra), but no nitrate was found. The fraction > 500 nm is dominated by C and CS particles, the silicate particles have a narrow size distribution around 100 nm and contain, if at all, only faint sulfur peaks in their EDS spectra. The results are qualitatively consistent with analyses of samples collected during the same campaign (Weinbruch et al., 2005), but during mixed cloud events. There seem to be, however a differrence in the amount of particles with sulfate coatings, which is higher for samples taken under clear sky conditions. Weinbruch, S., Ebert, S., Worringen, A., and Brenker (2005), Identification of the ice forming fraction of the atmospheric aerosol in mixed-phase clouds by environmental scanning electron microscopy. Activity report 2005, International Foundation HFSJG.
2. Aerosol Sampling System for Collection of Capstone Depleted Uranium Particles in a High-Energy Environment
SciTech Connect
Holmes, Thomas D.; Guilmette, Raymond A.; Cheng, Yung-Sung; Parkhurst, MaryAnn; Hoover, Mark D.
2009-03-01
The Capstone Depleted Uranium Aerosol Study was undertaken to obtain aerosol samples resulting from a kinetic-energy cartridge with a large-caliber depleted uranium (DU) penetrator striking an Abrams or Bradley test vehicle. The sampling strategy was designed to (1) optimize the performance of the samplers and maintain their integrity in the extreme environment created during perforation of an armored vehicle by a DU penetrator, (2) collect aerosols as a function of time post-impact, and (3) obtain size-classified samples for analysis of chemical composition, particle morphology, and solubility in lung fluid. This paper describes the experimental setup and sampling methodologies used to achieve these objectives. Custom-designed arrays of sampling heads were secured to the inside of the target in locations approximating the breathing zones of the vehicle commander, loader, gunner, and driver. Each array was designed to support nine filter cassettes and nine cascade impactors mounted with quick-disconnect fittings. Shielding and sampler placement strategies were used to minimize sampler loss caused by the penetrator impact and the resulting fragments of eroded penetrator and perforated armor. A cyclone train was used to collect larger quantities of DU aerosol for chemical composition and solubility. A moving filter sample was used to obtain semicontinuous samples for depleted uranium concentration determination. Control for the air samplers was provided by five remotely located valve control and pressure monitoring units located inside and around the test vehicle. These units were connected to a computer interface chassis and controlled using a customized LabVIEW engineering computer control program. The aerosol sampling arrays and control systems for the Capstone study provided the needed aerosol samples for physicochemical analysis, and the resultant data were used for risk assessment of exposure to DU aerosol.
3. Aerosol sampling system for collection of Capstone depleted uranium particles in a high-energy environment.
PubMed
Holmes, Thomas D; Guilmette, Raymond A; Cheng, Yung Sung; Parkhurst, Mary Ann; Hoover, Mark D
2009-03-01
The Capstone Depleted Uranium (DU) Aerosol Study was undertaken to obtain aerosol samples resulting from a large-caliber DU penetrator striking an Abrams or Bradley test vehicle. The sampling strategy was designed to (1) optimize the performance of the samplers and maintain their integrity in the extreme environment created during perforation of an armored vehicle by a DU penetrator, (2) collect aerosols as a function of time post perforation, and (3) obtain size-classified samples for analysis of chemical composition, particle morphology, and solubility in lung fluid. This paper describes the experimental setup and sampling methodologies used to achieve these objectives. Custom-designed arrays of sampling heads were secured to the inside of the target in locations approximating the breathing zones of the crew locations in the test vehicles. Each array was designed to support nine filter cassettes and nine cascade impactors mounted with quick-disconnect fittings. Shielding and sampler placement strategies were used to minimize sampler loss caused by the penetrator impact and the resulting fragments of eroded penetrator and perforated armor. A cyclone train was used to collect larger quantities of DU aerosol for measurement of chemical composition and solubility. A moving filter sample was used to obtain semicontinuous samples for DU concentration determination. Control for the air samplers was provided by five remotely located valve control and pressure monitoring units located inside and around the test vehicle. These units were connected to a computer interface chassis and controlled using a customized LabVIEW engineering computer control program. The aerosol sampling arrays and control systems for the Capstone study provided the needed aerosol samples for physicochemical analysis, and the resultant data were used for risk assessment of exposure to DU aerosol.
4. Power Spectral Densities of Atmospheric Aerosol Particle Counts
DTIC Science & Technology
2010-01-01
directly by absorbing and scattering radiation and indirectly by acting as cloud condensation nuclei (CCN). They are also important in atmospheric...are generated photochemically from vapor-phase terpenes emitted by plants; and combustion-generated particles from vehicular traffic, biomass
5. High velocity electromagnetic particle launcher for aerosol production studies
SciTech Connect
1986-05-01
This report describes the development of a new device for study of metal combustion, breakup and production of aerosols in a high velocity environment. Metal wires are heated and electromagnetically launched with this device to produce molten metal droplets moving at velocities ranging up to about Mach 1. Such tests are presently intended to simulate the behavior of metal streamers ejected from a high-explosive detonation. A numerical model of the launcher performance in terms of sample properties, sample geometry and pulser electrical parameters is presented which can be used as a tool for design of specific test conditions. Results from several tests showing the range of sample velocities accessible with this device are described and compared with the model. Photographic measurements showing the behavior of tungsten and zirconium metal droplets are presented. Estimates of the Weber breakup and drag on the droplets, as well as calculations of the droplet trajectories, are described. Such studies may ultimately be useful in assessing environmental hazards in the handling and storage of devices containing metallic plutonium.
6. Formation and Growth of New Organic Aerosol Particles over the Deepwater Horizon Oil Spill
Brock, C. A.; Murphy, D. M.; Bahreini, R.; Middlebrook, A. M.; De Gouw, J. A.
2011-12-01
Aerosol size distributions were measured in June 2010 downwind of the surface oil slick produced by the Deepwater Horizon oil spill in the Gulf of Mexico. Rapid condensation of partially oxidized hydrocarbons was responsible for formation of a plume of secondary organic aerosol downwind of the spill region. New particles were nucleated upwind of the freshest surface oil but downwind of oil that surfaced less than 100 hours previously. These new particles grew by condensation at rates of ~20 nm hr-1; preexisting accumulation mode particles grew by ~10 nm hr-1. The gas-phase concentration of a condensing species necessary to support the observed growth rate assuming irreversible adsorption with unit accommodation coefficient is estimated to be ~0.04-0.09 μg m-3 (~3-8 pptv). The ratio of growth rates for newly formed particles to accumulation mode particles was consistent within error limits with irreversible condensation. Because new particle formation did not occur in areas away from the <100 hr-old oil slick, these results indicate that the oxidation products of VOC species, probably C14-C16 compounds, were directly involved in the growth of the new particles. While a unique and extreme environment, the oil spill plume provides insight into similar processes that may occur in urban and industrial areas where petrochemical products are produced and consumed.
7. An effective inversion algorithm for retrieving bimodal aerosol particle size distribution from spectral extinction data
He, Zhenzong; Qi, Hong; Yao, Yuchen; Ruan, Liming
2014-12-01
The Ant Colony Optimization algorithm based on the probability density function (PDF-ACO) is applied to estimate the bimodal aerosol particle size distribution (PSD). The direct problem is solved by the modified Anomalous Diffraction Approximation (ADA, as an approximation for optically large and soft spheres, i.e., χ≫1 and |m-1|≪1) and the Beer-Lambert law. First, a popular bimodal aerosol PSD and three other bimodal PSDs are retrieved in the dependent model by the multi-wavelength extinction technique. All the results reveal that the PDF-ACO algorithm can be used as an effective technique to investigate the bimodal PSD. Then, the Johnson's SB (J-SB) function and the modified beta (M-β) function are employed as the general distribution function to retrieve the bimodal PSDs under the independent model. Finally, the J-SB and M-β functions are applied to recover actual measurement aerosol PSDs over Beijing and Shanghai obtained from the aerosol robotic network (AERONET). The numerical simulation and experimental results demonstrate that these two general functions, especially the J-SB function, can be used as a versatile distribution function to retrieve the bimodal aerosol PSD when no priori information about the PSD is available.
8. Mixing and water-soluble characteristics of particulate organic compounds in individual urban aerosol particles
Li, Weijun; Shao, Longyi
2010-01-01
Particulate organic compounds (POCs) in the atmosphere can alter the morphology and hygroscopicity of inorganic particles by coagulation and mixing. Direct observations can illustrate the mixing of organic and inorganic particles. Compositions, mixing states, and morphologies of 360 aerosol particles from urban Beijing collected on transmission electron microscopy (TEM) grids with Si-O substrate were obtained using TEM coupled with energy-dispersive X ray spectrometry (TEM/EDX). The Si-O substrate used in this study allows TEM/EDX to detect carbonaceous particles internally mixed with inorganic particles. POCs were present in approximately 90% of the nitrate-coated mineral particles on both hazy and clear days. Approximately 73% of K- and S-rich particles contained organic coatings and organic inclusions/aggregations on hazy days, while 53% of S-rich particles on clear days during the Beijing Olympics contained only organic coatings. Water dialysis of individual particles indicated that the organic inclusions/aggregations in the K- and S-rich particles were insoluble in water but that POCs from the coatings of individual particles were soluble. The organic coatings on individual inorganic particles may influence their surface hygroscopicity and optical properties.
9. Computational fluid dynamics (CFD) simulations of dilute fluid-particle flows in aerosol concentrators
Hari, Sridhar
2003-07-01
In this study, commercially available Computational Fluid Dynamics (CFD) software, CFX-4.4 has been used for the simulations of aerosol transport through various aerosol-sampling devices. Aerosol transport was modeled as a classical dilute and dispersed two-phase flow problem. Eulerian-Lagrangian framework was adopted wherein the fluid was treated as the continuous phase and aerosol as the dispersed phase, with a one-way coupling between the phases. Initially, performance of the particle transport algorithm implemented in the code was validated against available experimental and numerical data in the literature. Code predictions were found to be in good agreement against experimental data and previous numerical predictions. As a next step, the code was used as a tool to optimize the performance of a virtual impactor prototype. Suggestions on critical geometrical details available in the literature, for a virtual impactor, were numerically investigated on the prototype and the optimum set of parameters was determined. Performance curves were generated for the optimized design at various operating conditions. A computational model of the Linear Slot Virtual Impactor (LSVI) fabricated based on the optimization study, was constructed using the worst-case values of the measured geometrical parameters, with offsets in the horizontal and vertical planes. Simulations were performed on this model for the LSVI operating conditions. Behavior of various sized particles inside the impactor was illustrated with the corresponding particle tracks. Fair agreement was obtained between code predictions and experimental results. Important information on the virtual impactor performance, not known earlier, or, not reported in the literature in the past, obtained from this study, is presented. In the final part of this study, simulations on aerosol deposition in turbulent pipe flow were performed. Code predictions were found to be completely uncorrelated to experimental data. The
10. Aerosol synthesis of nano and micro-scale zero valent metal particles from oxide precursors
SciTech Connect
Phillips, Jonathan; Luhrs, Claudia; Lesman, Zayd; Soliman, Haytham; Zea, Hugo
2010-01-01
In this work a novel aerosol method, derived form the batch Reduction/Expansion Synthesis (RES) method, for production of nano / micro-scale metal particles from oxides and hydroxides is presented. In the Aerosol-RES (A-RES) method, an aerosol, consisting of a physical mixture of urea and metal oxide or hydroxides, is passed through a heated oven (1000 C) with a residence time of the order of 1 second, producing pure (zero valent) metal particles. It appears that the process is flexible regarding metal or alloy identity, allows control of particle size and can be readily scaled to very large throughput. Current work is focused on creating nanoparticles of metal and metal alloy using this method. Although this is primarily a report on observations, some key elements of the chemistry are clear. In particular, the reducing species produced by urea decomposition are the primary agents responsible for reduction of oxides and hydroxides to metal. It is also likely that the rapid expansion that takes place when solid/liquid urea decomposes to form gas species influences the final morphology of the particles.
11. T-matrix calculations of fractal black carbon atmospheric aerosol particle optical scattering
Smith, Anna; Boness, David
2008-05-01
To better constrain global climate change computer models, and thereby to more fully understand the full extent of anthropogenic climate change, it is necessary to understand the physics of light scattering from those atmospheric aerosol particles that are caused by human activities. The IPCC AR4 report on the physical basis of climate change lists uncertainty in the effects of black carbon aerosol particles, caused by burning fossil fuels and organic matter, as one of the greatest uncertainties in current climate change understanding. This study hopes to increase the knowledge of how aerosols contribute to radiative forcing by using more realistic modeling of scattering properties. We use D. W. Mackowski's T- matrix code on fractal aggregates of uniform spherical monomers and compare this with fractal scattering predicted by the Raleigh-Debye-Gans approximation. The T-matrix code is checked for accuracy with one spherical particle as found with Mie theory. Scattering properties found using the T-matrix method are performed as a function of fractal dimension and number of monomers. Preliminary results will be presented. Future work will involve comparison with soot particle optical scattering measurements made at Seattle University.
12. Aircraft observations of the physical and radiative properties of biomass aerosol particles during SAFARI-2000.
Osborne, S. R.; Haywood, J. M.
2001-12-01
An initial analysis will be shown from the ~80 h of data collected between 2--18 September 2000 by the UK Met Office C-130 aircraft during the dry season campaign of the Southern African Regional Science Initiative (SAFARI-2000). The talk will concentrate on the physical and optical properties of the biomass aerosol. The evolution of the particle size spectrum and its optical properties at emission and after ageing will be shown. The vertical distribution of the biomass plume over the land and sea will be compared in view of the local meteorology. A generalised three log-normal model is shown to represent aged biomass aerosol over the sea areas, both in terms of the number and mass particle size spectra, but also derived optical properties (e.g. asymmetry factor, single scatter albedo (ω 0) and extinction coefficient) as calculated using Mie theory and appropriate refractive indices. ω 0 was determined independently using a particle soot absorption photometer (giving the absorption coefficient at a wavelength of 0.567 μ m) and a nephelometer (giving the scattering coefficients at 0.45, 0.55 and 0.65 μ m). Good agreement was found between the measurements and those obtained from the Mie calculations and observed size distributions. A typical value of ω 0 at 0.55 μ m for aged biomass aerosol was 0.90. The radiative properties of the biomass aerosol over both land and sea will be summarised. Stratocumulus cloud was present on some of the days over the sea and the surprising lack of interaction between the elevated biomass plume (containing significant levels of cloud condensation nuclei) and the cloud capping the marine boundary layer will be illustrated. Using the cloud-free and cloudy case studies we can begin to elucidate the levels of direct and indirect forcing of the biomass aerosol on a regional scale. >http://www.mrfnet.demon.co.uk/africa/SAFARI2000.htm
13. Extraction of Optical Constants from Mid-IR Spectra of Small Aerosol Particles
Segal-Rosenheimer, M.; Dubowski, Y.; Linker, R.
2008-12-01
Aerosol particles directly influence the Earth's radiation budget by absorbing and scattering incident short- wave (solar) radiation and long-wave terrestrial radiation. Broadband infrared measurements can provide valuable information on aerosol's composition and size distribution. However, quantitative analysis of mid- infrared aerosol extinction spectra in terms of their characteristics relies on complex refractive indices for the various aerosol constituents. Derivation of such optical constants is complicated, especially in the mid- infrared region, mainly due to the great variability of the imaginary part (k) of the complex refractive index N, and its influence on the real part (n). Most of previously reported methods for determining these constants (Wagner et al., 2005; Dohm et al., 2004; Earle et al, 2006) use aerosols with size distributions for which scattering occurs in the spectral range of the measurement, and so the explicit Mie theory calculations for the scattering and absorption efficiencies are required. These calculations necessitate some assumptions on the particles size distribution and an initial guess of the k spectrum in order to extract the optical properties from the acquired spectra. Also, the solution uniqueness relies on the fact that the particles are large enough. In the present work, we seek to simplify the above procedure and use small particles' spectra of known size distributions to deduce the optical constants. For particles (such as poly-disperse aerosols) having geometric mean of less than 0.15 μm, absorbance spectra in the mid-infrared range do not show any scattering features. Therefore, Rayleigh theory can be used to extract the imaginary part of the complex function f, where f=[(N2-1)/(N2+2)]. The real part of the f function is then extracted using the Kramers-Kronig transformation and the n and k can be derived using the relation between f, ɛ (complex dielectric function). k and n (Bohren and Huffman, 1983). The method
14. Composition of carbonaceous smoke particles from prescribed burning of a Canadian boreal forest: 1. Organic aerosol characterization by gas chromatography
SciTech Connect
Mazurek, M.A.; Laterza, C.; Newman, L.; Daum, P.; Cofer, W.R. III; Levine, J.S.; Winstead, E.L.
1995-06-01
In this study we examine the molecular organic constituents (C8 to C40 lipid compounds) collected as smoke particles from a Canadian boreal forest prescribed burn. Of special interest are (1) the molecular identity of polar organic aerosols, and (2) the amount of polar organic matter relative to the total mass of aerosol particulate carbon. Organic extracts of smoke aerosol particles show complex distributions of the lipid compounds when analyzed by capillary gas chromatography/mass spectrometry. The molecular constituents present as smoke aerosol are grouped into non-polar (hydrocarbons) and polar {minus}2 oxygen atoms) subtractions. The dominant chemical species found in the boreal forest smoke aerosol are unaltered resin compounds (C20 terpenes) which are abundant in unburned conifer wood, plus thermally altered wood lignins and other polar aromatic hydrocarbons. Our results show that smoke aerosols contain molecular tracers which are related to the biofuel consumed. These smoke tracers can be related structurally back to the consumed softwood and hardwood vegetation. In addition, combustion of boreal forest materials produces smoke aerosol particles that are both oxygen-rich and chemically complex, yielding a carbonaceous aerosol matrix that is enriched in polar substances. As a consequence, emissions of carbonaceous smoke particles from large-scale combustion of boreal forest land may have a disproportionate effect on regional atmospheric chemistry and on cloud microphysical processes.
15. Uptake of 13N-labeled N2O5 to citric acid aerosol particles
Grzinic, Goran; Bartels-Rausch, Thorsten; Birrer, Mario; Türler, Andreas; Ammann, Markus
2013-04-01
Dinitrogen pentoxide is a significant reactive intermediate in the night time chemistry of nitrogen oxides. Depending on atmospheric conditions it can act either as a NO3 radical reservoir or as a major NOx sink by heterogeneous hydrolysis on aerosol surfaces. As such, it can influence tropospheric ozone production and therefore the oxidative capacity of the atmosphere. Furthermore it's suspected of being a non negligible source of tropospheric Cl, even over continental areas [1,2]. We used the short-lived radioactive tracer 13N delivered by PSI's PROTRAC facility [3] in conjunction with an aerosol flow tube reactor in order to study N2O5 uptake kinetics on aerosol particles. 13NO is mixed with non labeled NO and O3 in a gas reactor where N2O5 is synthesized under dry conditions to prevent hydrolysis on the reactor walls. The resulting N2O5 flow is fed into an aerosol flow tube reactor together with a humidified aerosol flow. By using movable inlets we can vary the length of the aerosol flow tube and thus the reaction time. The gas feed from the reactor is then directed into a narrow parallel plate diffusion denuder system that allows for selective separation of the gaseous species present in the gas phase. Aerosol particles are trapped on a particle filter placed at the end of the denuder system. The activity of 13N labeled species trapped on the denuder plates and in the particle filter can be monitored via scintillation counters. Aerosol uptake measurements were performed with citric acid aerosols in a humidity range of 27-61.5% RH. The results obtained from our measurements have shown that the uptake coefficient increases with humidity from 1.65±0.3x10-3 (~27% RH) to 1.25±0.3x10-2 (45% RH) and 2.00±0.3x10-2 (61.5% RH). Comparison to literature data shows that this is similar to values reported for some polycarboxylic acids (like malonic acid), while being higher than some others [4]. The increase is likely related to the increasing amount of water associated
16. Evaluation of SAGE II and Balloon-Borne Stratospheric Aerosol Measurements: Evaluation of Aerosol Measurements from SAGE II, HALOE, and Balloonborne Optical Particle Counters
NASA Technical Reports Server (NTRS)
Hervig, Mark; Deshler, Terry; Moddrea, G. (Technical Monitor)
2002-01-01
Stratospheric aerosol measurements from the University of Wyoming balloonborne optical particle counters (OPCs), the Stratospheric Aerosol and Gas Experiment (SAGE) II, and the Halogen Occultation Experiment (HALOE) were compared in the period 1982-2000, when measurements were available. The OPCs measure aerosol size distributions, and HALOE multiwavelength (2.45-5.26 micrometers) extinction measurements can be used to retrieve aerosol size distributions. Aerosol extinctions at the SAGE II wavelengths (0.386-1.02 micrometers) were computed from these size distributions and compared to SAGE II measurements. In addition, surface areas derived from all three experiments were compared. While the overall impression from these results is encouraging, the agreement can change with latitude, altitude, time, and parameter. In the broadest sense, these comparisons fall into two categories: high aerosol loading (volcanic periods) and low aerosol loading (background periods and altitudes above 25 km). When the aerosol amount was low, SAGE II and HALOE extinctions were higher than the OPC estimates, while the SAGE II surface areas were lower than HALOE and the OPCS. Under high loading conditions all three instruments mutually agree to within 50%.
17. Composition of Stratospheric Aerosol Particles collected during the SOLVE campaign 2000
Schütze, Katharina; Nathalie, Benker; Martin, Ebert; Ralf, Weigel; Wilson James, C.; Stephan, Borrmann; Stephan, Weinbruch
2016-04-01
Stratospheric Aerosol particles were collected during the SAGE III Ozone loss and validation Experiment (SOLVE) in January-March 2000 in Kiruna/ Sweden onboard the scientific ER-2 aircraft with the Multi-Sample Aerosol Collection System. The particles are deposited on Cu transmission electron microscopy (TEM) grids. Particles of six samples from different flights (including one PSC sample) were analyzed by TEM and Energy Dispersive X-ray detection (EDX) regarding their size, chemical composition and morphology. Most particles are sulfates (formed from droplets of sulfuric acid) which are not resistant to the electron beam. In addition, refractory particles in the size range of 100-500 nm are found. They are either embedded in the sulfates or occur as single particles. The refractory particles are mainly carbonaceous showing only C and O as major peaks in their X-ray spectra. Some particles contain minor amounts of Si and Fe. Both, the O/C (median from 0.10-0.40), as well as Si/C (median from 0.05-0.32) ratios are increasing with time, from the middle of January to the end of February. The largest Fe/C ratio (median: 0.37) is found in a sample of the end of January. Based on the nanostructure and the absence of potassium as a tracer, biomass burning can be excluded as a source. Soot from diesel engines as well as from aircrafts show a nanostructure which is not found in the refractory particles. Due to the fact that large volcanic eruptions, which introduced material directly into the stratosphere, were missing since the eruption of Mt. Pinatubo in 1991, they are a very unlikely source of the refractory particles. The most likely source of the refractory particles is thus extraterrestrial material.
18. Linking variations in sea spray aerosol particle hygroscopicity to composition during two microcosm experiments
Forestieri, Sara D.; Cornwell, Gavin C.; Helgestad, Taylor M.; Moore, Kathryn A.; Lee, Christopher; Novak, Gordon A.; Sultana, Camille M.; Wang, Xiaofei; Bertram, Timothy H.; Prather, Kimberly A.; Cappa, Christopher D.
2016-07-01
The extent to which water uptake influences the light scattering ability of marine sea spray aerosol (SSA) particles depends critically on SSA chemical composition. The organic fraction of SSA can increase during phytoplankton blooms, decreasing the salt content and therefore the hygroscopicity of the particles. In this study, subsaturated hygroscopic growth factors at 85 % relative humidity (GF(85 %)) of predominately submicron SSA particles were quantified during two induced phytoplankton blooms in marine aerosol reference tanks (MARTs). One MART was illuminated with fluorescent lights and the other was illuminated with sunlight, referred to as the "indoor" and "outdoor" MARTs, respectively. Optically weighted GF(85 %) values for SSA particles were derived from measurements of light scattering and particle size distributions. The mean optically weighted SSA diameters were 530 and 570 nm for the indoor and outdoor MARTs, respectively. The GF(85 %) measurements were made concurrently with online particle composition measurements, including bulk composition (using an Aerodyne high-resolution aerosol mass spectrometer) and single particle (using an aerosol time-of-flight mass spectrometer) measurement, and a variety of water-composition measurements. During both microcosm experiments, the observed optically weighted GF(85 %) values were depressed substantially relative to pure inorganic sea salt by 5 to 15 %. There was also a time lag between GF(85 %) depression and the peak chlorophyll a (Chl a) concentrations by either 1 (indoor MART) or 3-to-6 (outdoor MART) days. The fraction of organic matter in the SSA particles generally increased after the Chl a peaked, also with a time lag, and ranged from about 0.25 to 0.5 by volume. The observed depression in the GF(85 %) values (relative to pure sea salt) is consistent with the large observed volume fractions of non-refractory organic matter (NR-OM) comprising the SSA. The GF(85 %) values exhibited a reasonable negative
19. A numerical study of the particle size distribution of an aerosol undergoing turbulent coagulation
Reade, Walter C.; Collins, Lance R.
2000-07-01
Coagulation and growth of aerosol particles subject to isotropic turbulence has been explored using direct numerical simulations. The computations follow the trajectories of 262 144 initial particles as they are convected by the turbulent flow field. Collision between two parent particles leads to the formation of a new daughter particle with the mass and momentum (but not necessarily the energy) of the parent particles. The initially monodisperse population of particles will develop a size distribution over time that is controlled by the collision dynamics. In an earlier study, Sundaram & Collins (1997) showed that collision rates in isotropic turbulence are controlled by two statistics: (i) the radial distribution of the particles and (ii) the relative velocity probability density function. Their study considered particles that rebound elastically; however, we find that the formula that they derived is equally valid in a coagulating system. However, coagulation alters the numerical values of these statistics from the values they attain for the elastic rebound case. This difference is substantial and must be taken into consideration to properly predict the evolution of the size distribution of a population of particles. The DNS results also show surprising trends in the relative breadth of the particle size distribution. First, in all cases, the standard deviation of the particle size distribution of particles with finite Stokes numbers is much larger than the standard deviation for either the zero-Stokes-number or infinite-Stokes-number limits. Secondly, for particles with small initial Stokes numbers, the standard deviation of the final particle size distribution decreases with increasing initial particle size; however, the opposite trend is observed for particles with slightly larger initial Stokes numbers. An explanation for these phenomena can be found by carefully examining the functional dependence of the radial distribution function on the particle size
20. Deposition of Particles in the Alveolar Airways: Inhalation and Breath-Hold with Pharmaceutical Aerosols
PubMed Central
Khajeh-Hosseini-Dalasm, Navvab; Longest, P. Worth
2014-01-01
Previous studies have demonstrated that factors such as airway wall motion, inhalation waveform, and geometric complexity influence the deposition of aerosols in the alveolar airways. However, deposition fraction correlations are not available that account for these factors in determining alveolar deposition. The objective of this study was to generate a new space-filling model of the pulmonary acinus region and implement this model to develop correlations of aerosol deposition that can be used to predict the alveolar dose of inhaled pharmaceutical products. A series of acinar models was constructed containing different numbers of alveolar duct generations based on space-filling 14-hedron elements. Selected ventilation waveforms were quick-and-deep and slow-and-deep inhalation consistent with the use of most pharmaceutical aerosol inhalers. Computational fluid dynamics simulations were used to predict aerosol transport and deposition in the series of acinar models across various orientations with gravity where ventilation was driven by wall motion. Primary findings indicated that increasing the number of alveolar duct generations beyond 3 had a negligible impact on total acinar deposition, and total acinar deposition was not affected by gravity orientation angle. A characteristic model containing three alveolar duct generations (D3) was then used to develop correlations of aerosol deposition in the alveolar airways as a function of particle size and particle residence time in the geometry. An alveolar deposition parameter was determined in which deposition correlated with d2t over the first half of inhalation followed by correlation with dt2, where d is the aerodynamic diameter of the particles and t is the potential particle residence time in the alveolar model. Optimal breath-hold times to allow 95% deposition of inhaled 1, 2, and 3 μm particles once inside the alveolar region were approximately >10, 2.7, and 1.2 s, respectively. Coupling of the deposition
1. Single particle mass spectral signatures from vehicle exhaust particles and the source apportionment of on-line PM2.5 by single particle aerosol mass spectrometry.
PubMed
Yang, Jian; Ma, Shexia; Gao, Bo; Li, Xiaoying; Zhang, Yanjun; Cai, Jing; Li, Mei; Yao, Ling'ai; Huang, Bo; Zheng, Mei
2017-03-24
In order to accurately apportion the many distinct types of individual particles observed, it is necessary to characterize fingerprints of individual particles emitted directly from known sources. In this study, single particle mass spectral signatures from vehicle exhaust particles in a tunnel were performed. These data were used to evaluate particle signatures in a real-world PM2.5 apportionment study. The dominant chemical type originating from average positive and negative mass spectra for vehicle exhaust particles are EC species. Four distinct particle types describe the majority of particles emitted by vehicle exhaust particles in this tunnel. Each particle class is labeled according to the most significant chemical features in both average positive and negative mass spectral signatures, including ECOC, NaK, Metal and PAHs species. A single particle aerosol mass spectrometry (SPAMS) was also employed during the winter of 2013 in Guangzhou to determine both the size and chemical composition of individual atmospheric particles, with vacuum aerodynamic diameter (dva) in the size range of 0.2-2μm. A total of 487,570 particles were chemically analyzed with positive and negative ion mass spectra and a large set of single particle mass spectra was collected and analyzed in order to identify the speciation. According to the typical tracer ions from different source types and classification by the ART-2a algorithm which uses source fingerprints for apportioning ambient particles, the major sources of single particles were simulated. Coal combustion, vehicle exhaust, and secondary ion were the most abundant particle sources, contributing 28.5%, 17.8%, and 18.2%, respectively. The fraction with vehicle exhaust species particles decreased slightly with particle size in the condensation mode particles.
2. Diurnal Cycles of Aerosol Optical Properties at Pico Tres Padres, Mexico City: Evidences for Changes in Particle Morphology and Secondary Aerosol Formation
Mazzoleni, C.; Dubey, M.; Chakrabarty, R.; Moosmuller, H.; Onasch, T.; Zavala, M.; Herndon, S.; Kolb, C.
2007-12-01
Aerosol optical properties affect planetary radiative balance and depend on chemical composition, size distribution, and morphology. During the MILAGRO field campaign, we measured aerosol absorption and scattering in Mexico City using the Los Alamos aerosol photoacoustic (LAPA) instrument operating at 781 nm. The LAPA was mounted on-board the Aerodyne Research Inc. mobile laboratory, which hosted a variety of gaseous and aerosol instruments. During the campaign, the laboratory was moved to different sites, capturing spatial and temporal variability. Additionally, we collected ambient aerosols on Nuclepore filters for scanning electron microscopy (SEM) analysis. SEM images of selected filters were taken to study particle morphology. Between March 7th and 19th air was sampled at the top of Pico Tres Padres, a mountain on the north side of Mexico City. Aerosol absorption and scattering followed diurnal patterns related to boundary layer height and solar insulation. We report an analysis of aerosol absorption, scattering, and morphology for three days (9th, 11th and 12th of March 2006). The single scattering albedo (SSA, ratio of scattering to total extinction) showed a drop in the tens-of-minutes-to-hour time frame after the boundary layer grew above the sampling site. Later in the day the SSA rose steadily reaching a maximum in the afternoon. The SEM images showed a variety of aerosol shapes including fractal-like aggregates, spherical particles, and other shapes. The absorption correlated with the CO2 signal and qualitatively with the fraction of fractal-like particles to the total particle count. In the afternoon the SSA qualitatively correlated with a relative increase in spherical particles and total particle count. These observed changes in optical properties and morphology can be explained by the dominant contribution of freshly emitted particles in the morning and by secondary particle formation in the afternoon. SSA hourly averaged values ranged from ~0.63 in
3. Detection of Free Tropospheric Air Masses With High So2 and Aerosol Concentrations: Evidence For New Aerosol Particle Formation By H2so4/h2o Nucleation
Katragkou, E.; Wilhelm, S.; Kiendler, A.; Arnold, F.; Minikin, A.; Schlager, H.; van Velthoven, P.
Sulfur dioxide and aerosol measurements were performed in the free troposphere (FT) and the Planetary Boundary Layer (PBL) above continental Europe. The measure- ments took place on board of the German research aircraft "Falcon" in 18 April 2001 as a part of the SCAVEX campaign. A novel aircraft based CIMS (Chemical Ion- ization Mass Spectrometry) instrument equipped with an ion trap mass spectrometer (ITMS) with a low detection limit (50pptv) and a high time resolution (1.3s) operated by MPI-K was used to perform the SO2 measurements. For the aerosol measurements DLR-IPA operated a Condensation Particle Size Analyzer, detecting particles with diameters d > 4, 7, 9 and 20nm and a PCASP-100X aerosol spectrometer probe (d > 100nm). In the measurements made mostly around 5000m altitude SO2 rich air masses were occasionally observed with SO2 VMR of up to 2900pptv. The strong SO2 pollu- tion was due to fast vertical transport of polluted continental PBL air and small-scale deep convection, as indicated by the 5-day backward 3D trajectories. These observa- tions of strong SO2 pollution have interesting implications for aerosol processes, in- cluding efficient formation of gaseous sulfuric acid (GSA) and new aerosol particles. They also imply fast growth of freshly nucleated aerosol particles, which increases the chance for new particles to grow to the size of a CCN. Our analysis indicates the occurrence of new particle formation by H2SO4/H2O nucleation and fast new particle growth by H2SO4/H2O condensation and self-coagulation in the different air masses encountered during the flight.
4. Physical and Chemical Characterization of Particles in the Upper Troposphere and Lower Stratosphere: Microanalysis of Aerosol Impactor Samples
NASA Technical Reports Server (NTRS)
Sheridan, Patrick J.
1999-01-01
Herein is reported activities to support the characterization of the aerosol in the upper troposphere (UT) and lower stratosphere (LS) collected during the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA) missions in 1994. Through a companion proposal, another group was to measure the size distribution of aerosols in the 0.008 to 2 micrometer diameter range and to collect for us impactor samples of particles larger than about 0.02 gm. In the first year, we conducted laboratory studies related to particulate deposition patterns on our collection substrates, and have performed the analysis of many ASHOE/MAESA aerosol samples from 1994 using analytical electron microscopy (AEM). We have been building an "aerosol climatology" with these data that documents the types and relative abundances of particles observed at different latitudes and altitudes. The second year (and non-funded extension periods) saw continued analyses of impactor aerosol samples, including more ASHOE/MAESA samples, some northern hemisphere samples from the NASA Stratospheric Photochemistry Aerosols and Dynamics Expedition (SPADE) program for comparison, and a few aerosol samples from the NASA Stratospheric TRacers of Atmospheric Transport (STRAT) program. A high-resolution field emission microscope was used for the analysis and re-analysis of a number of samples to determine if this instrument was superior in performance to our conventional electron microscope. In addition, some basic laboratory studies were conducted to determine the minimum detectable and analyzable particle size for different types of aerosols. In all, 61 aerosol samples were analyzed, with a total of over 30,000 individual particle analyses. In all analyzed samples, sulfate particles comprised the major aerosol number fraction. It must be stressed that particles composed of more than one species, for example sulfate and organic carbon, were classified
5. Estimating Black Carbon Aging Time-Scales with a Particle-Resolved Aerosol Model
SciTech Connect
Riemer, Nicole; West, Matt; Zaveri, Rahul A.; Easter, Richard C.
2010-01-13
Understanding the aging process of aerosol particles is important for assessing their chemical reactivity, cloud condensation nuclei activity, radiative properties and health impacts. In this study we investigate the aging of black carbon containing particles in an idealized urban plume using a new approach, the particleresolved aerosol model PartMC-MOSAIC. We present a method to estimate aging time-scales using an aging criterion based on cloud condensation nuclei activation. The results show a separation into a daytime regime where condensation dominates and a nighttime regime where coagulation dominates. For the chosen urban plume scenario, depending on the supersaturation threshold, the values for the aging timescales vary between 0.06 hours and 10 hours during the day, and between 6 hours and 20 hours during the night.
6. Simultaneous ion luminescence imaging and spectroscopy of individual aerosol particles with external proton or helium microbeams
Kada, Wataru; Satoh, Takahiro; Yokoyama, Akihito; Koka, Masashi; Kamiya, Tomihiro
2014-08-01
Simultaneous microscopic imaging and spectroscopy of individual aerosol particles were performed with an external microbeam. Visible luminescence induced by the external microbeam was successfully used as a probe to detect organic contaminants in the targets. Combined ion luminescence (IL)/particle-induced X-ray emission (PIXE) analysis of the aerosol targets revealed microscopic chemical and elemental composition distributions under ambient atmospheric conditions. The simple confocal micro-optics for the IL spectroscopy and microscopic imaging were sufficiently sensitive for detecting these molecules at sub-parts per million concentrations and at a wavelength resolution of less than 5 nm. The IL spectra were monitored to prevent severe damage to the samples. Furthermore, our IL system has the advantage that it is simple to add to a conventional micro-PIXE system.
7. Lake spray aerosol generation: a method for producing representative particles from freshwater wave breaking
May, Nathaniel W.; Axson, Jessica L.; Watson, Alexa; Pratt, Kerri A.; Ault, Andrew P.
2016-09-01
Wave-breaking action in bodies of freshwater produces atmospheric aerosols via a similar mechanism to sea spray aerosol (SSA) from seawater. The term lake spray aerosol (LSA) is proposed to describe particles formed by this mechanism, which have been observed over the Laurentian Great Lakes. Though LSA has been identified from size distribution measurements during a single measurement campaign, no measurements of LSA composition or relationship to bubble-bursting dynamics have been conducted. An LSA generator utilizing a plunging jet, similar to many SSA generators, was constructed for the generation of aerosol from freshwater samples and model salt solutions. To evaluate this new generator, bubble and aerosol number size distributions were measured for salt solutions representative of freshwater (CaCO3) and seawater (NaCl) at concentrations ranging from that of freshwater to seawater (0.05-35 g kg-1), synthetic seawater (inorganic), synthetic freshwater (inorganic), and a freshwater sample from Lake Michigan. Following validation of the bubble and aerosol size distributions using synthetic seawater, a range of salt concentrations were investigated. The systematic studies of the model salts, synthetic freshwater, and Lake Michigan sample indicate that LSA is characterized by a larger number size distribution mode diameter of 300 nm (lognormal), compared to seawater at 110 nm. Decreasing salt concentrations from seawater to freshwater led to greater bubble coalescence and formation of larger bubbles, which generated larger particles and lower aerosol number concentrations. This resulted in a bimodal number size distribution with a primary mode (180 ± 20 nm) larger than that of SSA, as well as a secondary mode (46 ± 6 nm) smaller than that of SSA. This new method for studying LSA under isolated conditions is needed as models, at present, utilize SSA parameterizations for freshwater systems, which do not accurately predict the different size distributions observed
8. Detection of biological particles in ambient air using Bio-Aerosol Mass Spectrometry
SciTech Connect
McJimpsey, E L; Steele, P T; Coffee, K R; Fergenson, D P; Riot, V J; Woods, B W; Gard, E E; Frank, M; Tobias, H J; Lebrilla, C
2006-03-16
The Bio-Aerosol Mass Spectrometry (BAMS) system is an instrument used for the real time detection and identification of biological aerosols. Particles are drawn from the atmosphere directly into vacuum and tracked as they scatter light from several continuous wave lasers. After tracking, the fluorescence of individual particles is excited by a pulsed 266nm or 355nm laser. Molecules from those particles with appropriate fluorescence properties are subsequently desorbed and ionized using a pulsed 266nm laser. Resulting ions are analyzed in a dual polarity mass spectrometer. During two field deployments at the San Francisco International Airport, millions of ambient particles were analyzed and a small but significant fraction were found to have fluorescent properties similar to Bacillus spores and vegetative cells. Further separation of non-biological background particles from potential biological particles was accomplished using laser desorption/ionization mass spectrometry. This has been shown to enable some level of species differentiation in specific cases, but the creation and observation of higher mass ions is needed to enable a higher level of specificity across more species. A soft ionization technique, matrix-assisted laser desorption/ionization (MALDI) is being investigated for this purpose. MALDI is particularly well suited for mass analysis of biomolecules since it allows for the generation of molecular ions from large mass compounds that would fragment under normal irradiation. Some of the initial results from a modified BAMS system utilizing this technique are described.
9. Liquid-liquid phase separation in aerosol particles: Imaging at the Nanometer Scale
SciTech Connect
O'Brien, Rachel; Wang, Bingbing; Kelly, Stephen T.; Lundt, Nils; You, Yuan; Bertram, Allan K.; Leone, Stephen R.; Laskin, Alexander; Gilles, Mary K.
2015-04-21
Atmospheric aerosols can undergo phase transitions including liquid-liquid phase separation (LLPS) while responding to changes in the ambient relative humidity (RH). Here, we report results of chemical imaging experiments using environmental scanning electron microscopy (ESEM) and scanning transmission x-ray microscopy (STXM) to investigate the LLPS of micron sized particles undergoing a full hydration-dehydration cycle. Internally mixed particles composed of ammonium sulfate (AS) and either: limonene secondary organic carbon (LSOC), a, 4-dihydroxy-3-methoxybenzeneaceticacid (HMMA), or polyethylene glycol (PEG-400) were studied. Events of LLPS with apparent core-shell particle morphology were observed for all samples with both techniques. Chemical imaging with STXM showed that both LSOC/AS and HMMA/AS particles were never homogeneously mixed for all measured RH’s above the deliquescence point and that the majority of the organic component was located in the shell. The shell composition was estimated as 65:35 organic: inorganic in LSOC/AS and as 50:50 organic: inorganic for HMMA/AS. PEG-400/AS particles showed fully homogeneous mixtures at high RH and phase separated below 89-92% RH with an estimated 50:50% organic to inorganic mix in the shell. These two chemical imaging techniques are well suited for in-situ analysis of the hygroscopic behavior, phase separation, and surface composition of collected ambient aerosol particles.
10. Chemical boundary conditions for the classification of aerosol particles using computer controlled electron probe microanalysis.
PubMed
Anaf, Willemien; Horemans, Benjamin; Van Grieken, René; De Wael, Karolien
2012-11-15
A method for the classification of individual aerosol particles using computer controlled electron probe microanalysis is presented. It is based on chemical boundary conditions (CBC) and enables quick and easy processing of a large set of elemental concentration data (mass%), derived from the X-ray spectra of individual particles. The particles are first classified into five major classes (sea salt related, secondary inorganic, minerals, iron-rich and carbonaceous), after which advanced data mining can be performed by examining the elemental composition of particles within each class into more detail (e.g., by ternary diagrams). The CBC method is validated and evaluated by comparing its results with the output obtained with hierarchical cluster analysis (HCA) for well-known standard particles as well as real aerosol particles collected with a cascade impactor. The CBC method gives reliable results and has a major advantage compared to HCA. CBC is based on boundary conditions that are derived from chemical logical thinking and does not require a translation of a mathematical algorithm output as does HCA. Therefore, the CBC method is more objective and enables comparison between samples without intermediate steps.
11. Microscopic Characterization of Carbonaceous Aerosol Particle Aging in the Outflow from Mexico City
SciTech Connect
Moffet, R. C.; Henn, T. R.; Tivanski, A. V.; Hopkins, R. J.; Desyaterik, Y.; Kilcoyne, A. L. D.; Tyliszczak, T.; Fast, J.; Barnard, J.; Shutthanandan, V.; Cliff, S.S.; Perry, K. D.; Laskin, A.; Gilles, M. K.
2009-09-16
This study was part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) field campaign conducted in Mexico City Metropolitan Area during spring 2006. The physical and chemical transformations of particles aged in the outflow from Mexico City were investigated for the transport event of 22 March 2006. A detailed chemical analysis of individual particles was performed using a combination of complementary microscopy and micro-spectroscopy techniques. The applied techniques included scanning transmission X-ray microscopy (STXM) coupled with near edge X-ray absorption fine structure spectroscopy (NEXAFS) and computer controlled scanning electron microscopy with an energy dispersive X-ray analyzer (CCSEM/EDX). As the aerosol plume evolves from the city center, the organic mass per particle increases and the fraction of carbon-carbon double bonds (associated with elemental carbon) decreases. Organic functional groups enhanced with particle age include: carboxylic acids, alkyl groups, and oxygen bonded alkyl groups. At the city center (T0) the most prevalent aerosol type contained inorganic species (composed of sulfur, nitrogen, oxygen, and potassium) coated with organic material. At the T1 and T2 sites, located northeast of T0 (~;;29 km and ~;;65 km, respectively), the fraction of homogenously mixed organic particles increased in both size and number. These observations illustrate the evolution of the physical mixing state and organic bonding in individual particles in a photochemically active environment.
12. Physicochemical Characterization of Coarse Lake Spray Aerosol Particle from Lake Michigan
Ault, A. P.; Axson, J. L.; May, N.; Pratt, K.; Colon-Bernal, I. D.
2015-12-01
Wave breaking across bodies of water releases coarse particles into the air which can impact climate and human health. Freshwater lakes, such as the Great Lakes, can generate lake spray aerosols (LSA), similarly to how sea spray is generated, during periods of high winds and wave action. This LSA has the potential to impact climate through direct and indirect effects (ie. scattering/absorption and cloud nucleation) and are suggested to impact human health via inhalation of these particles during algal bloom periods characterized by toxic cyanobacteria. Very few studies have been conducted to assess the physicochemical properties of freshwater LSA. Prior work in our lab included the construction and characterization of a laboratory based LSA generator. In this work, we examine laboratory generated aerosol particles from laboratory based freshwater standards, freshwater samples collected from Lake Michigan, and ambient particles collected during a wave event on the shores of Lake Michigan in the summer of 2015. Particle size distributions, number concentrations, and chemical composition are presented and discussed as a function of laboratory generated and ambient collected LSA. Results indicate that there are characteristic particles that represent LSA. This study represents the next step towards evaluating and understanding the potential for coarse LSA to impact climate and health in the Great Lakes region.
13. Indoor/outdoor radon decay products associated aerosol particle-size distributions and their relation to total number concentrations.
PubMed
Moriizumi, Jun; Yamada, Shinya; Xu, Yang; Matsuki, Satoru; Hirao, Shigekazu; Yamazawa, Hiromi
2014-07-01
The activity size distributions of indoor and outdoor radioactive aerosol associated with short-lived radon decay products were observed at Nagoya, Japan, for some periods from 2010 to 2012, following the indoor observation by Mostafa et al. [Mostafa, A. M. A., Tamaki, K., Moriizumi, J., Yamazawa, H. and Iida, T. The weather dependence of particle size distribution of indoor radioactive aerosol associated with radon decay products. Radiat. Prot. Dosim. 146: (1-3), 19-22 (2011)]. The tendency of smaller indoor activity median aerodynamic diameter (AMAD) after rainfalls showed in the previous study was not consistently obtained, while the consistent tendency of less indoor radioactive particles with diameters in the accumulation mode was observed again after rainfalls. The indoor aerosols showed activity size distributions similar to the outdoor ones. Non-radioactive aerosol particle concentrations measured with a laser particle counter suggested a somewhat liner relationship with AMAD.
14. Effects of explosively venting aerosol-sized particles through earth-containment systems on the cloud-stabilization height
SciTech Connect
Dyckes, G.W.
1980-07-01
A method of approximating the cloud stabilization height for aerosol-sized particles vented explosively through earth containment systems is presented. The calculated values for stabilization heights are in fair agreement with those obtained experimentally.
15. Solid versus liquid particle sampling efficiency of three personal aerosol samplers when facing the wind.
PubMed
Koehler, Kirsten A; Anthony, T Renee; Van Dyke, Michael; Volckens, John
2012-03-01
The objective of this study was to examine the facing-the-wind sampling efficiency of three personal aerosol samplers as a function of particle phase (solid versus liquid). Samplers examined were the IOM, Button, and a prototype personal high-flow inhalable sampler head (PHISH). The prototype PHISH was designed to interface with the 37-mm closed-face cassette and provide an inhalable sample at 10 l min(-1) of flow. Increased flow rate increases the amount of mass collected during a typical work shift and helps to ensure that limits of detection are met, particularly for well-controlled but highly toxic species. Two PHISH prototypes were tested: one with a screened inlet and one with a single-pore open-face inlet. Personal aerosol samplers were tested on a bluff-body disc that was rotated along the facing-the-wind axis to reduce spatiotemporal variability associated with sampling supermicron aerosol in low-velocity wind tunnels. When compared to published data for facing-wind aspiration efficiency for a mouth-breathing mannequin, the IOM oversampled relative to mannequin facing-the-wind aspiration efficiency for all sizes and particle types (solid and liquid). The sampling efficiency of the Button sampler was closer to the mannequin facing-the-wind aspiration efficiency than the IOM for solid particles, but the screened inlet removed most liquid particles, resulting in a large underestimation compared to the mannequin facing-the-wind aspiration efficiency. The open-face PHISH results showed overestimation for solid particles and underestimation for liquid particles when compared to the mannequin facing-the-wind aspiration efficiency. Substantial (and statistically significant) differences in sampling efficiency were observed between liquid and solid particles, particularly for the Button and screened-PHISH, with a majority of aerosol mass depositing on the screened inlets of these samplers. Our results suggest that large droplets have low penetration efficiencies
16. Aerosol Particle Size as a Factor in Pulmonary Toxicity
DTIC Science & Technology
1974-12-01
second rCptresents rhi sical clearance b\\ muco- ciliar \\ traIS- Ix~rt to the throat for subsequent swallowing. Expeilimcntal data indicate that the anterior...particles b v macr.phages with translocation tu the ciliated airways and, (d) transfer of pxarticles to the lymphatic system including lymph nodes. Thie...can remain suspnded in air for long periods (due to viscous drag) and can undergo rapid dissolution in the body ’. From 13halen (1972). 361 AINIRL-TR
17. Isotope source apportionment of carbonaceous aerosol as a function of particle size and thermal refractiveness
Masalaite, Agne; Holzinger, Rupert; Remeikis, Vidmantas; Röckmann, Thomas; Dusek, Ulrike
2016-04-01
The stable carbon isotopes can be used to get information about sources and processing of carbonaceous aerosol. We will present results from source apportionment of carbonaceous aerosol as a function of particle size thermal refractiveness. Separate source apportionment for particles smaller than 200 nm and for different carbon volatility classes are rarely reported and give new insights into aerosol sources in the urban environment. Stable carbon isotope ratios were measured for the organic carbon (OC) fraction and total carbon (TC) of MOUDI impactor samples that were collected on a coastal site (Lithuania) during the winter 2012 and in the city of Vilnius (Lithuania) during the winter of 2009. The 11 impactor stages spanned a size range from 0.056 to 18 μm, but only the 6 stages in the submicron range were analysed. The δ13C values of bulk total carbon (δ13CTC) were determined with an elemental analyser (Flash EA 1112) coupled with an isotope ratio mass spectrometer (Thermo Finnigan Delta Plus Advantage) (EA - IRMS). Meanwhile δ13COC was measured using thermal-desorption isotope ratio mass spectrometry (IRMS) system. This allows a rough separation of the more volatile OC fraction (desorbed in the oven of IRMS up to 250 0C) from the more refractory fraction (desorbed up to 400 0C). In this study we investigated the composition of organic aerosol desorbed from filter samples at different temperatures using the thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) technique. During winter-time in Lithuania we expect photochemistry and biogenic emissions to be of minor importance. The main sources of aerosol carbon should be fossil fuel and biomass combustion. In both sites, the coastal and the urban site, δ13C measurements give a clear indication that the source contributions differ for small and large particles. Small particles < 200 nm are depleted in 13C with respect to larger particles by 1 - 2 ‰Ṫhis shows that OC in small particle
18. Infrared spectroscopic methods for the study of aerosol particles using White cell optics: Development and characterization of a new aerosol flow tube.
PubMed
Nájera, Juan J; Fochesatto, Javier G; Last, Deborah J; Percival, Carl J; Horn, Andrew B
2008-12-01
A description of a new aerosol flow tube apparatus for measurements in situ under atmospherically relevant conditions is presented here. The system consists of a laboratory-made nebulizer generation system and a flow tube with a White cell-based Fourier transform IR for the detection system. An assessment of the White cell coupled to the flow tube was carried out by an extensive set of experiments to ensure the alignment of the infrared beam and optimize the performance of this system. The detection limit for CO was established as (1.0+/-0.3) ppm and 16 passes was chosen as the optimum number of passes to be used in flow tube experiments. Infrared spectroscopy was used to characterize dry aerosol particles in the flow tube. Pure particles composed of ammonium sulfate or sodium chloride ranging between 0.8 and 2.1 mum for size diameter and (0.8-4.9)x10(6) particles/cm(3) for density number were generated by nebulization of aqueous solutions. Direct measurements of the aerosol particle size agree with size spectra retrieved from inversion of the extinction measurements using Mie calculations, where the difference residual value is in the order of 0.2%. The infrared detection limit for ammonium sulfate aerosol particles was determined as d(p)=0.9 mum and N=5x10(3) particles/cm(3) with sigma=1.1 by Mie calculation. Alternatively, Mie calculations were performed to determine the flexibility in varying the optical length when aerosol particles are sent by the injector. The very good agreement between the values retrieved for aerosol particles injected through the flow tube or through the injector clearly validates the estimation of the effective optical path length for the injector. To determine the flexibility in varying the reaction zone length, analysis of the extinction spectra as function of the position of the injector was carried out by monitoring the integrated area of different absorption modes of the ammonium sulfate. We conclude that the aerosol loss in the
19. Infrared spectroscopic methods for the study of aerosol particles using White cell optics: Development and characterization of a new aerosol flow tube
Nájera, Juan J.; Fochesatto, Javier G.; Last, Deborah J.; Percival, Carl J.; Horn, Andrew B.
2008-12-01
A description of a new aerosol flow tube apparatus for measurements in situ under atmospherically relevant conditions is presented here. The system consists of a laboratory-made nebulizer generation system and a flow tube with a White cell-based Fourier transform IR for the detection system. An assessment of the White cell coupled to the flow tube was carried out by an extensive set of experiments to ensure the alignment of the infrared beam and optimize the performance of this system. The detection limit for CO was established as (1.0±0.3) ppm and 16 passes was chosen as the optimum number of passes to be used in flow tube experiments. Infrared spectroscopy was used to characterize dry aerosol particles in the flow tube. Pure particles composed of ammonium sulfate or sodium chloride ranging between 0.8 and 2.1 μm for size diameter and (0.8-4.9)×106 particles/cm3 for density number were generated by nebulization of aqueous solutions. Direct measurements of the aerosol particle size agree with size spectra retrieved from inversion of the extinction measurements using Mie calculations, where the difference residual value is in the order of 0.2%. The infrared detection limit for ammonium sulfate aerosol particles was determined as dp=0.9 μm and N =5×103 particles/cm3 with σ =1.1 by Mie calculation. Alternatively, Mie calculations were performed to determine the flexibility in varying the optical length when aerosol particles are sent by the injector. The very good agreement between the values retrieved for aerosol particles injected through the flow tube or through the injector clearly validates the estimation of the effective optical path length for the injector. To determine the flexibility in varying the reaction zone length, analysis of the extinction spectra as function of the position of the injector was carried out by monitoring the integrated area of different absorption modes of the ammonium sulfate. We conclude that the aerosol loss in the flow tube
20. Aerosol and CCN properties at Princess Elisabeth station, East Antarctica: seasonality, new particle formation events and properties around precipitation events
Mangold, Alexander; Laffineur, Quentin; De Backer, Hugo; Herenz, Paul; Wex, Heike; Gossart, Alexandra; Souverijns, Niels; Gorodetskaya, Irina; Van Lipzig, Nicole
2016-04-01
Since 2010, several complementary ground-based instruments for measuring the aerosol composition of the Antarctic atmosphere have been operated at the Belgian Antarctic research station Princess Elisabeth, in Dronning Maud Land, East Antarctica (71.95° S, 23.35° E, 1390 m asl.). In addition, three ground-based remote sensing instruments for cloud and precipitation observations have been installed for continuous operation, including a ceilometer (cloud base height, type, vertical extent), a 24 Ghz micro-rain radar (vertical profiles of radar effective reflectivity and Doppler velocity), and a pyrometer (cloud base temperature). The station is inhabited from November to end of February and operates under remote control during the other months. In this contribution, the general aerosol and cloud condensation nuclei (CCN) properties will be described with a special focus on new particle formation events and around precipitation events. New particle formation events are important for the atmospheric aerosol budget and they also show that aerosols are not only transported to Antarctica but are also produced there, also inland. Aerosols are essential for cloud formation and therefore also for precipitation, which is the only source for mass gain of the Antarctic ice sheet. Measured aerosol properties comprise size distribution, total number, total mass concentration, mass concentration of light-absorbing aerosol and absorption coefficient and total scattering coefficient. In addition, a CCN counter has been operated during austral summers 2013/14, 2014/15 and 2015/16. The baseline total number concentration N-total was around some hundreds of particles/cm3. During new particle formation events N-total increased to some thousands of particles/cm3. Simultaneous measurements of N-total, size distribution and CCN number revealed that mostly the number of particles smaller than 100 nm increased and that the concentration of cloud condensation nuclei increased only very
1. Effect of fatty acid coatings on ozone uptake to deliquesced KI/NaCl aerosol particles
Ammann, M.; Rouvière, A.
2009-12-01
Phase transfer kinetics of gas phase oxidants may limit oxidative aging of aerosol particles. The aim of this work is to study the role of amphiphilic organic aerosol constituents on the kinetics of phase transfer of gaseous species to the bulk aqueous phase. The effect of (C9-C20) fatty acid surfactants on the phase transfer of ozone to deliquesced potassium iodide and sodium chloride have been investigated. Some other experiments of ozone uptake have been performed with different mixtures and proportions of fatty acids. The kinetic experiments were performed in an aerosol flow tube at room temperature and atmospheric pressure. To obtain deliquesced inorganic particles, the relative humidity was adjusted in the range of 75% to 80%. It is shown that the fatty acids in monolayer quantities may substantially inhibit the phase transfer of ozone to deliquesced particles. The results showed that especially the C15-C20 limit the mass transfer of ozone to the aqueous phase, whereby the magnitude of this effect was following the monolayer properties of the fatty acids. It was also possible to determine a resistance of such films to the transfer of ozone to the bulk phase.
2. Particle-Induced X-Ray Emission Analysis of Atmospheric Aerosols
Gleason, Colin; Harrington, Charles; Schuff, Katie; Battaglia, Maria; Moore, Robert; Turley, Colin; Vineyard, Michael; Labrake, Scott
2010-11-01
We are developing a research program in ion-beam analysis (IBA) of atmospheric aerosols at the Union College Ion-Beam Analysis Laboratory to study the transport, transformation, and effects of airborne pollution in Upstate New York. The simultaneous applications of the IBA techniques of particle-induced X-ray emission (PIXE), Rutherford back-scattering spectrometry (RBS), particle-induced gamma-ray emission (PIGE), and proton elastic scattering analysis (PESA) is a powerful tool for the study of airborne pollution because they are non-destructive and provide quantitative information on nearly all elements of the periodic table. PIXE is the main IBA technique because it is able to detect nearly all elements from Na to U with high sensitivities and low detection limits. The aerosol samples are collected with cascade impactors that allow for the study of particulate matter as a function of particle size and the samples are analyzed using proton beams with energies around 2 MeV from the Union College 1.1-MV Pelletron Accelerator. The emitted X-rays are measured using a silicon drift detector with a resolution of 136 eV. We will describe how the aerosol samples were collected, discuss the PIXE analysis, and present preliminary results.
3. The real part of the refractive indices and effective densities for chemically segregated ambient aerosols in Guangzhou by a single particle aerosol mass spectrometer
Zhang, G.; Bi, X.; Qiu, N.; Han, B.; Lin, Q.; Peng, L.; Chen, D.; Wang, X.; Peng, P.; Sheng, G.; Zhou, Z.
2015-12-01
Microphysical properties of atmospheric aerosols are essential to better evaluate their radiative forcing. This paper first presents an estimate of the real part of the refractive indices (n) and effective densities (ρeff) of chemically segregated atmospheric aerosols in China. Vacuum aerodynamic diameter, chemical compositions, and light scattering intensities of individual particles were simultaneously measured by a single particle aerosol mass spectrometer (SPAMS) during fall of 2012 in Guangzhou. On the basis of Mie theory, n and ρeff were estimated for 17 particle types in four categories: organics (OC), elemental carbon (EC), internally mixed EC and OC (ECOC), and metal rich, respectively. Results indicate the presence of spherical or nearly spherical shape for majority of particle types, whose partial scattering cross section vs. sizes were well fitted to Mie theoretical modeling results. While sharing n in a narrow range (1.47-1.53), majority of particle types exhibited a wide range of ρeff (0.87-1.51 g cm-3). OC group is associated with the lowest ρeff (0.87-1.07 g cm-3), while metal rich group with the highest ones (1.29-1.51 g cm-3). It is noteworthy that a specific EC type exhibits a complex scattering curve vs. size due to the presence of both compact and irregularly shape particles. Overall, the results on detailed relationship between physical and chemical properties benefits future researches on the impact of aerosols on visibility and climate.
4. Aging of Soot Particles: Remote Marine Free-tropospheric Aerosol at the Pico Mountain Observatory, Azores
China, S.; Mazzoleni, C.; Mazzoleni, L. R.; kumar, S.; Dziobak, M.; Fialho, P. J.; Dzepina, K.; Hueber, J.; Helmig, D.; Kramer, L. J.; Sharma, N.; Olsen, S. C.; Owen, R. C.
2013-12-01
Soot particles, often referred to as black carbon, are aggregates of carbonaceous monomers that strongly absorb light, significantly impacting the environment, Earth's radiation balance, atmospheric chemistry and properties of clouds. Soot can be transported over long distances, thus affecting global climate. During transport, soot aggregates undergo chemical and morphological changes such as oxidation, mixing, coating and restructuring. These changes have a significant impact on soot's light absorption and scattering efficiencies, and therefore on soot's effects on climate. Free tropospheric aerosols are being studied at the Pico Mountain Observatory, located near the top of the Pico Volcano in the Azores, Portugal (38.47°N, 28.40°W, 2225m asl). Typically above the marine boundary layer, this is an ideal site to study aerosol transported over long distances across the ocean, often from North America and sometimes from Africa and Europe. We studied the morphology and mixing state of individual soot particles using electron microscopy and energy dispersive X-ray spectroscopy. We also measured the optical properties of aerosols using light scattering data from a 3-wavelength nephelometer, and black carbon mass equivalent concentrations using a 7-wavelength aethalometer. In this presentation, we focus on samples collected during two events in July 2012. Back trajectory analysis shows that in both periods the air masses reaching Pico were traveling from west to east, apparently originating in North America. Soot particles were classified into four categories based on their coating and mixing state. We investigated the morphology of soot particles in the four categories, using various descriptors (e.g. aspect ratio, roundness and convexity), monomer size and fractal dimension. Most of the soot particles were coated. Bare or very thinly coated soot, exhibited very compacted structures and high convexity. The results of this study have implications on how soot particles
5. Water uptake of clay and desert dust aerosol particles at sub- and supersaturated water vapor conditions
SciTech Connect
Herich, Hanna; Tritscher, Torsten; Wiacek, Aldona; Gysel, Martin; Weingartner, E.; Lohmann, U.; Baltensperger, Urs; Cziczo, Daniel J.
2009-11-01
Airborne mineral dust particles serve as cloud condensation nuclei (CCN), thereby influencing the formation and properties of warm clouds. It is therefore of particular interest how dust aerosols with different mineralogy behave when exposed to high relative humidity (RH) or supersaturation with respect to liquid water similar to atmospheric conditions. In this study the sub-saturated hygroscopic growth and the supersaturated cloud condensation nucleus activity of pure clays and real desert dust aerosols was determined using a hygroscopicity tandem differential mobility analyzer (HTDMA) and a cloud condensation nuclei counter (CCNC), respectively. Five different illite, montmorillonite and kaolinite clay samples as well as three desert dust samples (Saharan dust (SD), Chinese dust (CD) and Arizona test dust (ATD)) were used. Aerosols were generated both with a wet and a dry disperser and the water uptake was parameterized via the hygroscopicity parameter, κ. The hygroscopicity of dry generated dust aerosols was found to be negligible when compared to processed atmospheric aerosols, with CCNC derived κ values between 0.00 and 0.02. The latter value can be idealized as a particle consisting of 96.7% (by volume) insoluble material and ~3.3% ammonium sulfate. Pure clay aerosols were found to be generally less hygroscopic than real desert dust particles. All illite and montmorillonite samples had κ~0.003, kaolinites were least hygroscopic and had κ=0.001. SD (κ=0.023) was found to be the most hygroscopic dry-generated desert dust followed by CD (κ=0.007) and ATD (κ=0.003). Wet-generated dust showed an increased water uptake when compared to dry-generated samples. This is considered to be an artifact introduced by redistribution of soluble material between the particles while immersed in an aqueous medium during atomization, thus indicating that specification of the generation method is critically important when presenting such data. Any atmospheric processing of
6. Aerosol Mass Spectrometry via Laser-Induced Incandescence Particle Vaporization Final Report
SciTech Connect
Timothy B. Onasch
2011-10-20
We have successfully developed and commercialized a soot particle aerosol mass spectrometer (SP-AMS) instrument to measure mass, size, and chemical information of soot particles in ambient environments. The SP-AMS instrument has been calibrated and extensively tested in the laboratory and during initial field studies. The first instrument paper describing the SP-AMS has been submitted for publication in a peer reviewed journal and there are several related papers covering initial field studies and laboratory studies that are in preparation. We have currently sold 5 SP-AMS instruments (either as complete systems or as SP modules to existing AMS instrument operators).
7. Modified aerosol pyrolysis as a preparation route of hexaferrite particles for magnetic media
Pankov, V.; Henis, A.; Dubanevich, D.; Malashevich, A.; Shablovski, A.
1996-04-01
A survey is given of the modification in aerosol pyrolysis procedure for decreasing the particles size up to 10 nm adding the inert component (NaCl, NaCl + BaB2O4) to of the starting precursor of barium, iron nitrate and citrate solutions and demonstrate the facility of this technique in the synthesis of MeFe2y-2xCoxTixO19(x equals 0 - 0.8; y equals 5.6 - 6.0; Me equals Ba, Sr) small particles.
8. The particle size magnifier closing the gap between measurement of molecules, molecular clusters and aerosol particles
Mikkilä, Jyri; Lehtipalo, Katrianne; Kangasluoma, Juha; Franchin, Alessandro; Sipilä, Mikko; Jokinen, Tuija; Sarnela, Nina; Schobesberger, Siegfried; Junninen, Heikki; Kulmala, Markku; Worsnop, Douglas; Petäjä, Tuukka
2013-05-01
The Particle Size Magnifier lowers the cut-off size of a Condensation Particle Counter even down to about 1 nm in mobility diameter. By scanning the supersaturation also size information of the particles can be gained. We demonstrated that the PSM can detect particles starting from molecular sizes. By combining the data with newly developed mass spectrometric methods particle formation and growth can be followed molecule by molecule.
9. Characterization of Individual Aerosol Particles Associated with Clouds (CRYSTAL-FACE)
NASA Technical Reports Server (NTRS)
Buseck, Peter R.
2004-01-01
The aim of our research was to obtain data on the chemical and physical properties of individual aerosol particles from near the bottoms and tops of the deep convective systems that lead to the generation of tropical cirrus clouds and to provide insights into the particles that serve as CCN or IN. We used analytical transmission electron microscopy (ATEM), including energy-dispersive X-ray spectrometry (EDS) and electron energy-loss spectroscopy (EELS), and field-emission electron microscopy (FESEM) to compare the compositions, concentrations, size distributions, shapes, surface coatings, and degrees of aggregation of individual particles from cloud bases and the anvils near the tropopause. Aggregates of sea salt and mineral dust, ammonium sulfate, and soot particles are abundant in in-cloud samples. Cirrus samples contain many H2SO4 droplets, but acidic sulfate particles are rare at the cloud bases. H2SO4 probably formed at higher altitudes through oxidation of SO2 in cloud droplets. The relatively high extent of ammoniation in the upper troposphere in-cloud samples appears to have resulted from vertical transport by strong convection. The morphology of H2SO4 droplets indicates that they had been at least yartiy ammoniated at the time of collection. They are internally mixed with organic materials, metal sulfates, and solid particles of various compositions. Ammoniation and internal mixing of result in freezing at higher temperature than in pure H2SO4 aerosols. K- and S-bearing organic particles and Si-Al-rich particles are common throughout. Sea salt and mineral dust were incorporated into the convective systems from the cloud bases and worked as ice nuclei while being vertically transported. The nonsulfate particles originated from the lower troposphere and were transported to the upper troposphere and lower stratosphere.
10. Comparison of cloud residual and background aerosol particle composition during the hill cap cloud experiment HCCT 2010 in Central Germany
Roth, A.; Mertes, S.; van Pinxteren, D.; Klimach, T.; Herrmann, H.; Schneider, J.; Borrmann, S.
2013-12-01
Physical and chemical characterization of cloud residual and background aerosol particles as well as aerosol-cloud interactions were investigated during the Hill Cap Cloud Thuringia (HCCT) experiment in September and October 2010 on the mountain site Schmücke (938m a.s.l.) in Germany. Background aerosol particles were sampled by an interstitial inlet whereas cloud droplets from orographic clouds were collected by a counter flow virtual impactor (CVI). Chemical composition analysis and sizing of the particles was done by single particle mass spectrometry using the bipolar Aircraft-based Laser Ablation Aerosol Mass Spectrometer (ALABAMA, particle diameter range 150 nm - 900 nm; Brands et al., 2011) and by two Aerodyne Aerosol Mass Spectrometers (C-ToF, HR-ToF). Supplementary, the particle size distribution was measured with an optical particle counter (OPC, size range 0.25 μm - 32 μm). During the field campaign about 21000 positive and negative single particle mass spectra could be obtained from cloud residual particles and about 239000 from background aerosol particles. The data were clustered by means of the fuzzy c-means algorithm. The resulting clusters consisting of mass spectra with similar fragmentation patterns were, dependent on presence and combination of peaks, assigned to certain particle types. For both sampled particle types a large portion is internally mixed with nitrate and/or sulfate. This might be an explanation, why a comparison of the composition shows a higher fraction of soot particles and amine-containing particles among cloud residuals. Furthermore cloud residuals show a decreased fraction of particles being internally mixed only with nitrate (10%) compared to background aerosol particles (19%) of the same air masses, whereas the fraction of particles containing both nitrate and sulfate increases from 39% to 63% indicating cloud processing by uptake and oxidation of SO2 (Harris et al, 2013). Brands, M., Kamphus, M., Böttger, T., Schneider
11. Morphological characterization of soot aerosol particles during LACIS Experiment in November (LExNo)
Kiselev, A.; Wennrich, C.; Stratmann, F.; Wex, H.; Henning, S.; Mentel, T. F.; Kiendler-Scharr, A.; Schneider, J.; Walter, S.; Lieberwirth, I.
2010-06-01
Combined mobility and aerodynamic measurements were used to characterize the morphology of soot particles in an experimental campaign on the hygroscopic growth and activation of an artificial biomass burning aerosol. A custom-made, single-stage low-pressure impactor and two aerosol mass spectrometers (AMS) operating in the free molecular regime were used to measure the vacuum aerodynamic diameter of mobility-selected artificial soot particles that were produced in a spark discharge generator and then modified by condensation of ammonium hydrogen sulfate or levoglucosan as a coating to change their hydroscopic activity. Transmission electron microscope images revealed a relationship between the electrical mobility diameter and the diameter of the enveloping sphere, thus enabling evaluation of the effective density of soot agglomerates. A fractal description of the morphology of the soot aggregates allowed for evaluation of the average mass of the hygroscopic material per particle. The average mass of the hygroscopic material per particle was also measured directly with the two AMS instruments, and the agreement between the two methods was found satisfactory. This tandem approach allows detection of small changes in the particle effective density and morphology caused by condensation of organic material.
12. Formation of Secondary Particulate Matter by Reactions of Gas Phase Hexanal with Sulfate Aerosol Particles
Zhang, J.
2003-12-01
The formation of secondary particulate matter from the atmospheric oxidation of organic compounds can significantly contribute to the particulate burden, but the formation of organic secondary particulate matter is poorly understood. One way of producing organic secondary particulate matter is the oxidation of hydrocarbons with seven or more carbon atoms to get products with low vapor pressure. However, several recent reports suggest that relatively low molecular weight carbonyls can enter the particle phase by undergoing heterogeneous reactions. This may be a very important mechanism for the formation of organic secondary particulate matter. Atmospheric aldehydes are important carbonyls in the gas phase, which form via the oxidation of hydrocarbons emitted from anthropogenic and biogenic sources. In this poster, we report the results on particle growth by the heterogeneous reactions of hexanal. A 5 L Continuous Stirred Tank Reactor (CSTR) is set up to conduct the reactions in the presence of seed aerosol particles of deliquesced ammonia bisulfate. Hexanal is added into CSTR by syringe pump, meanwhile the concentrations of hexanal are monitored with High Pressure Liquid Chromatograph (HPLC 1050). A differential Mobility Analyzer (TSI 3071) set to an appropriate voltage is employed to obtain monodisperse aerosols, and another DMA associated with a Condensation Nuclear Counter (TSI 7610) is used to measure the secondary particle size distribution by the reaction in CSTR. This permits the sensitive determination of particle growth due to the heterogeneous reaction, very little growth occurs when hexanal added alone. Results for the simultaneous addition of hexanal and alcohols will also be presented.
13. The effect of formaldehyde and nitrogen-containing compounds on the size and volume of aerosol particles
Millage, K.; Galloway, M. M.; De Haan, D. O.
2012-12-01
Atmospheric aerosol can interact with clouds in many ways, often resulting in the redistribution or absorption of solar energy or changes in precipitation efficiency. Secondary organic aerosol (SOA) in particular has been linked to climate change and a reduction in the number and size of cloud particles. The reactions of nitrogen containing compounds (primary amines, amino acids and ammonium sulfate) with carbonyl compounds (such as formaldehyde and glycolaldehyde) are potential sources of SOA. Aerosol containing formaldehyde and nitrogen-containing compounds (glycine, methylamine, arginine, or ammonium sulfate) was generated from buffered solutions (pH 5.4) using a nebulizer. The aerosol was then equilibrated into a chamber containing humid air (82-84% RH), and particle sizes were measured using a SMPS system over a period of 1 hour in order to examine how the size and volume of the aerosol particles changed. Formaldehyde concentrations were varied over multiple experiments. Arginine displayed a trend of increasing relative particle size with increasing formaldehyde concentration. Ammonium sulfate and formaldehyde displayed a decrease in relative particle sizes from 0:1 to 2:1 ratios of formaldehyde to ammonium sulfate, but then an increase in relative particle sizes with increasing amounts of formaldehyde. Similarly, glycine and methylamine initially displayed decreasing relative particle sizes, until reaching a 1:1 ratio of each to formaldehyde at which point the relative particle sizes steadily increased. These effects were likely caused by the evaporation of first-generation imine products.
14. Physical and chemical characterization of marine atmospheric aerosols over the North and South Pacific Oceans using single particle mass spectrometry
Furutani, H.; Jung, J.; Miura, K.; Uematsu, M.
2010-12-01
Physical and chemical properties of marine atmospheric aerosols were characterized and compared over the North and South Pacific Ocean during two trans-Pacific cruises (from Japan to Chile and Australia to Japan) during the period of January-June 2009, which cover broad region of Pacific Ocean from 40°N to 55°S and 140°E to 70°W. The measured parameters of aerosol properties were single particle size-resolved chemical composition (D = 100 ~ 1500 nm), cloud condensation nuclei (CCN) and condensation nuclei (CN) concentrations, size distribution from 10 nm to 5 μm, total aerosol nitrate and sulfate concentrations, and filter-based chemical composition. Trace gas concentrations of O3 and CO were also measured to aid air parcel categorization during the cruises. Reflecting larger anthropogenic emission in the Northern Hemisphere, pronounced concentration gradient between the North and South Pacific Ocean was observed for aerosol nitrate, CO, and O3. Aerosol sulfate also showed a similar concentration drop in the equatorial region, relatively higher sulfate concentration was observed in 30°S-40°S and 55°S regions, which was associated with increased aerosol methanesulfonic acid (MSA) concentration but little increase in local marine chlorophyll concentration, suggesting contribution of long-range transported marine biogenic sulfur from the high primary production area over the South Pacific high latitude region. Aerosol chemical classification by single particle chemical analysis revealed that certain aerosol types, such as biomass burning, elemental carbon, and elemental/organic carbon mixed type, were mainly observed in the North Pacific region, while several specific organic aerosol types with abundant aged organic and disulfur composition were identified in the South Pacific region. Further comparison of aerosol properties, aerosol sources, and atmospheric aerosol processing in the North and South Pacific Oceans will be discussed.
15. Particle Loss Calculator - a new software tool for the assessment of the performance of aerosol inlet systems
von der Weiden, S.-L.; Drewnick, F.; Borrmann, S.
2009-09-01
Most aerosol measurements require an inlet system to transport aerosols from a select sampling location to a suitable measurement device through some length of tubing. Such inlet systems must be optimized to minimize aerosol sampling artifacts and maximize sampling efficiency. In this study we introduce a new multifunctional software tool (Particle Loss Calculator, PLC) that can be used to quickly determine aerosol sampling efficiency and particle transport losses due to passage through arbitrary tubing systems. The software employs relevant empirical and theoretical relationships found in established literature and accounts for the most important sampling and transport effects that might be encountered during deployment of typical, ground-based ambient aerosol measurements through a constant-diameter sampling probe. The software treats non-isoaxial and non-isokinetic aerosol sampling, aerosol diffusion and sedimentation as well as turbulent inertial deposition and inertial deposition in bends and contractions of tubing. This software was validated through comparison with experimentally determined particle losses for several tubing systems bent to create various diffusion, sedimentation and inertial deposition properties. As long as the tube geometries are not "too extreme", agreement is satisfactory. We discuss the conclusions of these experiments, the limitations of the software and present three examples of the use of the Particle Loss Calculator in the field.
16. Particle Loss Calculator - a new software tool for the assessment of the performance of aerosol inlet systems
von der Weiden, S.-L.; Drewnick, F.; Borrmann, S.
2009-04-01
Most aerosol measurements require an inlet system to transport aerosols from a select sampling location to a suitable measurement device through some length of tubing. Such inlet systems must be optimized to minimize aerosol sampling artifacts and maximize sampling efficiency. In this study we introduce a new multifunctional software tool (Particle Loss Calculator, PLC) that can be used to quickly determine aerosol sampling efficiency and particle transport losses due to passage through arbitrary tubing systems. The software employs relevant empirical and theoretical relationships found in established literature and accounts for the most important sampling and transport effects that might be encountered during deployment of typical, ground-based ambient aerosol measurements. The software treats non-isoaxial and non-isokinetic aerosol sampling, aerosol diffusion and sedimentation as well as turbulent inertial deposition and inertial deposition in bends and contractions of tubing. This software was validated through comparison with experimentally determined particle losses for several tubing systems bent to create various diffusion, sedimentation and inertial deposition properties. As long as the tube geometries are not "too extreme", agreement is satisfactory. We discuss the conclusions of these experiments, the limitations of the software and present three examples of the use of the Particle Loss Calculator in the field.
17. Size distribution dynamics reveal particle-phase chemistry in organic aerosol formation
Shiraiwa, M.; Yee, L. D.; Schilling, K.; Loza, C. L.; Craven, J. S.; Zuend, A.; Ziemann, P. J.; Seinfeld, J.
2013-12-01
Organic aerosols are ubiquitous in the atmosphere and play a central role in climate, air quality and public health. The aerosol size distribution is key in determining its optical properties and cloud condensation nucleus activity. The dominant portion of organic aerosol is formed through gas-phase oxidation of volatile organic compounds, so-called secondary organic aerosol (SOA). Typical experimental measurements of SOA formation include total SOA mass and atomic oxygen-to-carbon ratio. These measurements, alone, are generally insufficient to reveal the extent to which condensed-phase reactions occur in conjunction with the multi-generation gas-phase photooxidation. Combining laboratory chamber experiments and kinetic gas-particle modeling for the dodecane SOA system, here we show that the presence of particle-phase chemistry is reflected in the evolution of the SOA size distribution as well as its mass concentration. Particle-phase reactions are predicted to occur mainly at the particle surface and the reaction products contribute more than half of the SOA mass. Chamber photooxidation with a mid-experiment aldehyde injection confirms that heterogeneous reaction of aldehydes with organic hydroperoxides forming peroxyhemiacetals can lead to a large increase in SOA mass. The results of the current work have a number of implications for SOA models. While the dynamics of an aerosol size distribution reflects the mechanism of growth, we demonstrate here that it provides a key constraint in interpreting laboratory and ambient SOA formation. This work, although carried out specifically for the long chain alkane, dodecane, is expected to be widely applicable to other major classes of SOA precursors. SOA consists of a myriad of organic compounds containing various functional groups, which can generally undergo heterogeneous/multiphase reactions forming low-volatility products such as oligomers and other high molecular mass compounds. If particle-phase chemistry is indeed
18. A concept of an automated function control for ambient aerosol measurements using mobility particle size spectrometers
Bastian, S.; Löschau, G.; Wiedensohler, A.
2014-04-01
An automated function control unit was developed to regularly check the ambient particle number concentration derived from a mobility particle size spectrometer as well as its zero-point behaviour. The function control allows unattended quality assurance experiments at remote air quality monitoring or research stations under field conditions. The automated function control also has the advantage of being able to get a faster system stability response than the recommended on-site comparisons with reference instruments. The method is based on a comparison of the total particle number concentration measured by a mobility particle size spectrometer and a condensation particle counter while removing diffusive particles smaller than 20 nm in diameter. In practice, the small particles are removed by a set of diffusion screens, as traditionally used in a diffusion battery. Another feature of the automated function control is to check the zero-point behaviour of the ambient aerosol passing through a high-efficiency particulate air (HEPA) filter. The performance of the function control is illustrated with the aid of a 1-year data set recorded at Annaberg-Buchholz, a station in the Saxon air quality monitoring network. During the period of concern, the total particle number concentration derived from the mobility particle size spectrometer slightly overestimated the particle number concentration recorded by the condensation particle counter by 2 % (grand average). Based on our first year of experience with the function control, we developed tolerance criteria that allow a performance evaluation of a tested mobility particle size spectrometer with respect to the total particle number concentration. We conclude that the automated function control enhances the quality and reliability of unattended long-term particle number size distribution measurements. This will have beneficial effects for intercomparison studies involving different measurement sites, and help provide a higher
19. Raman microscopy of size-segregated aerosol particles, collected at the Sonnblick Observatory in Austria
Ofner, Johannes; Kasper-Giebl, Anneliese; Kistler, Magdalena; Matzl, Julia; Schauer, Gerhard; Hitzenberger, Regina; Lohninger, Johann; Lendl, Bernhard
2014-05-01
Size classified aerosol samples were collected using low pressure impactors in July 2013 at the high alpine background site Sonnnblick. The Sonnblick Observatory is located in the Austrian Alps, at the summit of Sonnblick 3100 m asl. Sampling was performed in parallel on the platform of the Observatory and after the aerosol inlet. The inlet is constructed as a whole air inlet and is operated at an overall sampling flow of 137 lpm and heated to 30 °C. Size cuts of the eight stage low pressure impactors were from 0.1 to 12.8 µm a.d.. Alumina foils were used as sample substrates for the impactor stages. In addition to the size classified aerosol sampling overall aerosol mass (Sharp Monitor 5030, Thermo Scientific) and number concentrations (TSI, CPC 3022a; TCC-3, Klotz) were determined. A Horiba LabRam 800HR Raman microscope was used for vibrational mapping of an area of about 100 µm x 100 µm of the alumina foils at a resolution of about 0.5 µm. The Raman microscope is equipped with a laser with an excitation wavelength of 532 nm and a grating with 300 gr/mm. Both optical images and the related chemical images were combined and a chemometric investigation of the combined images was done using the software package Imagelab (Epina Software Labs). Based on the well-known environment, a basic assignment of Raman signals of single particles is possible at a sufficient certainty. Main aerosol constituents e.g. like sulfates, black carbon and mineral particles could be identified. First results of the chemical imaging of size-segregated aerosol, collected at the Sonnblick Observatory, will be discussed with respect to standardized long-term measurements at the sampling station. Further, advantages and disadvantages of chemical imaging with subsequent chemometric investigation of the single images will be discussed and compared to the established methods of aerosol analysis. The chemometric analysis of the dataset is focused on mixing and variation of single compounds at
20. Aerosol mass spectrometry: particle-vaporizer interactions and their consequences for the measurements
Drewnick, F.; Diesch, J.-M.; Faber, P.; Borrmann, S.
2015-04-01
The Aerodyne Aerosol Mass Spectrometer (AMS) is a frequently used instrument for on-line measurement of the ambient sub-micron aerosol composition. With the help of calibrations and a number of assumptions on the flash vaporization and electron impact ionization processes this instrument provides robust quantitative information on various ambient aerosol components. However, when measuring close to certain anthropogenic sources or in marine environments, several of these assumptions may not be met and measurement results might easily be misinterpreted. Here we discuss various aspects of the interaction of aerosol particles with the AMS tungsten vaporizer and the consequences for the measurement results: semi-refractory components, i.e. components that vaporize but do not flash vaporize at the vaporizer and ionizer temperatures, like metal halides (e.g. chlorides, bromides or iodides of Al, Ba, Cd, Cu, Fe, Hg, K, Na, Pb, Sr, Zn) can be measured semi-quantitatively despite their relatively slow vaporization from the vaporizer. Even though non-refractory components (e.g. NH4NO3 or (NH4)2SO4) vaporize quickly, their differences in vaporization kinetics can result in undesired biases in ion collection efficiency in the measurements. Chemical reactions with water vapor and oxygen from the aerosol flow can have an influence on the mass spectra for certain components (e.g. NH4NO3, (NH4)2SO4, organic species). Finally, chemical reactions of the aerosol with the vaporizer surface can result in additional signals in the mass spectra (e.g. WO2C2-related signals from particulate Cl) and in conditioning or contamination of the vaporizer with potential memory effects influencing the mass spectra of subsequent measurements. Laboratory experiments that investigate these particle-vaporizer interactions are presented and are discussed together with field results showing that measurements of typical continental or urban aerosols are not significantly affected while laboratory
1. A preliminary analysis of the surface chemistry of atmospheric aerosol particles in a typical urban area of Beijing.
PubMed
Zhang, Zhengzheng; Li, Hong; Liu, Hongyan; Ni, Runxiang; Li, Jinjuan; Deng, Liqun; Lu, Defeng; Cheng, Xueli; Duan, Pengli; Li, Wenjun
2016-09-01
Atmospheric aerosol particle samples were collected using an Ambient Eight Stage (Non-Viable) Cascade Impactor Sampler in a typical urban area of Beijing from 27th Sep. to 5th Oct., 2009. The surface chemistry of these aerosol particles was analyzed using Static Time of Flight-Secondary Ion Mass Spectrometry (Static TOF-SIMS). The factors influencing surface compositions were evaluated in conjunction with the air pollution levels, meteorological factors, and air mass transport for the sampling period. The results show that a variety of organic ion groups and inorganic ions/ion groups were accumulated on the surfaces of aerosol particles in urban areas of Beijing; and hydrophobic organic compounds with short- or middle-chain alkyl as well as hydrophilic secondary inorganic compounds were observed. All these compounds have the potential to affect the atmospheric behavior of urban aerosol particles. PM1.1-2.1 and PM3.3-4.7 had similar elements on their surfaces, but some molecules and ionic groups demonstrated differences in Time of Flight-Secondary Ion Mass Spectrometry spectra. This suggests that the quantities of elements varied between PM1.1-2.1 and PM3.3-4.7. In particular, more intense research efforts into fluoride pollution are required, because the fluorides on aerosol surfaces have the potential to harm human health. The levels of air pollution had the most significant influence on the surface compositions of aerosol particles in our study. Hence, heavier air pollution was associated with more complex surface compositions on aerosol particles. In addition, wind, rainfall, and air masses from the south also greatly influenced the surface compositions of these urban aerosol particles.
2. Rocket-borne Probes for Aerosol Particles in the Polar Mesosphere
Robertson, S.; Knappmiller, S.; Sternovsky, Z.; Horanyi, M.
2006-05-01
Two instruments have been developed to detect charged aerosol particles in the mesosphere. The first is a flat charge-collecting graphite surface on the skin of the rocket that has returned data in several sounding rocket campaigns. The collection surfaces have permanent magnets behind them to provide shielding from electrons, and have a positive voltage bias that repels light ions. Probes with and without an electric bias were launched in January 2005 from Esrange, Sweden, as a part of the MAGIC campaign. The probes detected a distinct layer of positive aerosols at around 82 km altitude. A second instrument has been developed to detect charged, sub-visible aerosol particles in the upper atmosphere. This instrument has a 30 square centimeter entrance slit that admits a continuous flow of air. Venting ports are placed lower on the detector in order to let the air out and reduce pressure buildup. The air sample flows between four pairs of graphite electrodes biased symmetrically with increasing bias potentials. Electrons, light ions, cluster ions and heavy charged aerosol particles of both polarities are collected mass-selectively on the electrodes that are connected to sensitive electrometers. Direct Simulation Monte Carlo (DSMC) codes have been used to optimize the supersonic airflow within and around the instrument. A laboratory prototype of the instrument has been fabricated and calibrated using low energy ion beams. Two of these instruments are scheduled for launch in the summer of 2007 from Andoya, Norway. These in-situ measurements are planned to coincide with measurements by the Aeronomy of Ice in the Mesosphere (AIM) satellite.
3. Ambient aerosol concentrations of sugars and sugar-alcohols at four different sites in Norway
Yttri, K. E.; Dye, C.; Kiss, G.
2007-08-01
Sugars and sugar-alcohols are demonstrated to be important constituents of the ambient aerosol water-soluble organic carbon fraction, and to be tracers for primary biological aerosol particles (PBAP). In the present study, levels of four sugars (fructose, glucose, sucrose, trehalose) and three sugar-alcohols (arabitol, inositol, mannitol) in ambient aerosols have been quantified using a novel HPLC/HRMS-TOF (High Performance Liquid Chromatography in combination with High Resolution Mass Spectrometry - Time of Flight) method to assess the contribution of PBAP to PM>sub>10 and PM2.5. Samples were collected at four sites in Norway at different times of the year in order to reflect the various contributing sources and the spatial and seasonal variation of the selected compounds. Sugars and sugar-alcohols were present at all sites investigated, underlining the ubiquity of these highly polar organic compounds. The highest concentrations were reported for sucrose, reaching a maximum concentration of 320 ng m-3 in PM10 and 55 ng m-3 in PM2.5. The mean concentration of sucrose was up to 10 times higher than fructose, glucose and the dimeric sugar trehalose. The mean concentrations of the sugar-alcohols were typically lower, or equal, to that of the monomeric sugars and trehalose. Peak concentrations of arabitol and mannitol did not exceed 30 ng m-3 in PM10, and for PM2.5 all concentrations were below 6 ng m-3. Sugars and sugar-alcohols were associated primarily with coarse aerosols except during wintertime at the suburban site in Elverum, where a shift towards sub micron aerosols was observed. It is proposed that this shift was due to the intensive use of wood burning for residential heating at this site during winter, confirmed by high concurrent concentrations of levoglucosan. Elevated concentrations of sugars in PM2.5 were observed during spring and early summer at the rural background site Birkenes. It is hypothesized that this was due to ruptured pollen.
4. Source apportionment of aerosol particles near a steel plant by electron microscopy.
PubMed
Ebert, Martin; Müller-Ebert, Dörthe; Benker, Nathalie; Weinbruch, Stephan
2012-12-01
The size, morphology and chemical composition of 37,715 individual particles collected over 22 sampling days in the vicinity of a large integrated steel production were studied by scanning and transmission electron microscopy. Based on the morphology, chemistry and beam stability the particles were classified into the following fourteen groups: silicates, sea salt, calcium sulfates, calcium carbonates, carbonate-silicate mixtures, sulfate-silicate mixtures, iron oxides, iron mixtures, metal oxide-metals, complex secondary particles, soot, Cl-rich particles, P-rich particles, and other particles. The majority of iron oxide (≈85%) and metal oxide-metal (≈70%) particles as well as ≈20% of the silicate particles are fly ashes from high temperature processes. The emissions from the steel work are dominated by iron oxide particles. For source apportionment, seven source categories and two sectors of local wind direction (industrial and urban background) were distinguished. In both sectors PM₁₀ consists of four major source categories: 35% secondary, 20% industrial, 17% soil and 16% soot in the urban background sector compared to 45% industrial, 20% secondary, 13% soil, and 9% soot in the industrial sector. As the secondary and the soot components are higher in the urban background sector than in the industrial sector, it is concluded that both components predominantly originate from urban background sources (traffic, coal burning, and domestic heating). Abatement measures should not only focus on the steel work but should also include the urban background aerosol.
5. A Single Particle Soot Photometer for the Measurement of Aerosol Black Carbon
Kok, G. L.; Baumgardner, D.; Spuler, S.
2002-12-01
A Single Particle Soot Photometer (SP2) has been developed for the measurement of black carbon mass in single particles. The analytical technique is the incandescence of light absorbing particles. An aerosol stream is directed intra-cavity across the beam of a Nd:YAG laser where the laser intensity is in excess of 1 MW/cm2. Non-light absorbing particles only scatter light but particles containing black carbon absorb sufficient energy to heat and incandesce as they vaporize. Four optical detectors are used to measure the scattered and incandescence radiation from the particles. One measures the scattered, 1064 nm radiation while the other three detectors measure the light of incandescence over different wavelength regions. The ratio of intensities at the different wavelengths yields the temperature at which the particle incandesced whereas the absolute intensity is proportional to the carbon mass. The minimum size of non-incandescing particles that can be measured is approximately 100 nm and for incandescing particles it is 80 nm. Data will be presented on the operation of the instrumentation and examples of ambient measurements of black carbon.
6. Constant size, variable density aerosol particles by ultrasonic spray freeze drying.
PubMed
D'Addio, Suzanne M; Chan, John Gar Yan; Kwok, Philip Chi Lip; Prud'homme, Robert K; Chan, Hak-Kim
2012-05-10
This work provides a new understanding of critical process parameters involved in the production of inhalation aerosol particles by ultrasonic spray freeze drying to enable precise control over particle size and aerodynamic properties. A series of highly porous mannitol, lysozyme, and bovine serum albumin (BSA) particles were produced, varying only the solute concentration in the liquid feed, c(s), from 1 to 5 wt%. The particle sizes of mannitol, BSA, and lysozyme powders were independent of solute concentration, and depend only on the drop size produced by atomization. Both mannitol and lysozyme formulations showed a linear relationship between the computed Fine Particle Fraction (FPF) and the square root of c(s), which is proportional to the particle density, ρ, given a constant particle size d(g). The FPF decreased with increasing c(s) from 57.0% to 16.6% for mannitol and 44.5% to 17.2% for lysozyme. Due to cohesion, the BSA powder FPF measured by cascade impaction was less than 10% and independent of c(s). Ultrasonic spray freeze drying enables separate control over particle size, d(g), and aerodynamic size, d(a) which has allowed us to make the first experimental demonstration of the widely accepted rule d(a)=d(g)(ρ/ρ(o))(1/2) with particles of constant d(g), but variable density, ρ (ρ(o) is unit density).
7. Origin of nitrocatechols and alkylated-nitrocatechols in atmospheric aerosol particles
Marchand, Nicolas; Sylvestre, Alexandre; Ravier, Sylvain; Detournay, Anais; Bruns, Emily; Temime-Roussel, Brice; Slowik, Jay; El Haddad, Imad; Prevot, Andre
2013-04-01
Biomass burning constitutes one of the major sources of aerosol particles in most of the environments during winter. If a lot of information is available in the literature on the primary fraction of biomass burning aerosol particles, almost nothing is known regarding the formation of Secondary Organic Aerosol (SOA) from the chemical mixture emitted by this source. Recently methylated nitrocatechol have been identified in atmospheric particles collected in winter. These compounds are strongly associated with biomass burning tracers such as levoglucosan and are suspected to be of secondary origin since they can be formed through the oxidation of cresol significantly emitted by biomass burning. However, nitrocatechols are particularly difficult to analyze using classical techniques like HPLC-MS or GC-MS. In the present study, we adopt a new analytical approach. Direct analysis in real time (DART), introduced by Cody et al. (2005), allows direct analysis of gases, liquids, solids and materials on surfaces. Thus, for particles collected onto filters, the sample preparation step is simplified as much as possible, avoiding losses and reducing to the minimum the analytical procedure time. Two analytic modes can be used. In positive mode, [MH]+ ions are formed by proton transfer reaction ; whereas in negative ionization mode, [MH]-, M- and [MO2]- ions are formed. DART source enables soft ionization and produces simple mass spectra suitable for analysis of complex matrices, like organic aerosol, in only a few seconds. For this study, the DART source was coupled to a Q-ToF mass spectrometer (Synapt G2 HDMS, Waters), with a mass resolution up to 40 000. The analysis of atmospheric aerosol samples, collected in Marseille during winter 2011 (APICE project), with the DART/Q-ToF approach highlighted the abundance of nitrocatechols and alkylated nitrocatechols. Their temporal trends were also very similar to those of levoglucosan or dihydroabietic acid well known tracers of biomass
8. Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign
SciTech Connect
Lee, Y. -N.; Springston, S.; Jayne, J.; Wang, J.; Hubbe, J.; Senum, G.; Kleinman, L.; Daum, P. H.
2014-01-01
The chemical composition of aerosol particles (Dp ≤ 1.5 μm) was measured over the southeast Pacific Ocean during the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) between 16 October and 15 November 2008 using the US Department of Energy (DOE) G-1 aircraft. The objective of these flights was to gain an understanding of the sources and evolution of these aerosols, and of how they interact with the marine stratus cloud layer that prevails in this region of the globe. Our measurements showed that the marine boundary layer (MBL) aerosol mass was dominated by non-sea-salt SO42−, followed by Na+, Cl, Org (total organics), NH4+, and NO3, in decreasing order of importance; CH3SO3 (MSA), Ca2+, and K+ rarely exceeded their limits of detection. Aerosols were strongly acidic with a NH4+ to SO42− equivalents ratio typically < 0.3. Sea-salt aerosol (SSA) particles, represented by NaCl, exhibited Cl deficits caused by both HNO3 and H2SO4, but for the most part were externally mixed with particles, mainly SO42−. SSA contributed only a small fraction of the total accumulation mode particle number concentration. It was inferred that all aerosol species (except SSA) were of predominantly continental origin because of their strong land-to-sea concentration gradient. Comparison of relative changes in median values suggests that (1) an oceanic source of NH3 is present between 72° W and 76° W, (2) additional organic aerosols from biomass burns or biogenic precursors were emitted from coastal regions south of 31° S, with possible cloud processing, and (3) free tropospheric (FT) contributions to MBL gas and aerosol
9. An investigation into particle shape effects on the light scattering properties of mineral dust aerosol
Meland, Brian Steven
Mineral dust aerosol plays an important role in determining the physical and chemical equilibrium of the atmosphere. The radiative balance of the Earth's atmosphere can be affected by mineral dust through both direct and indirect means. Mineral dust can directly scatter or absorb incoming visible solar radiation and outgoing terrestrial IR radiation. Dust particles can also serve as cloud condensation nuclei, thereby increasing albedo, or provide sites for heterogeneous reactions with trace gas species, which are indirect effects. Unfortunately, many of these processes are poorly understood due to incomplete knowledge of the physical and chemical characteristics of the particles including dust concentration and global distribution, as well as aerosol composition, mixing state, and size and shape distributions. Much of the information about mineral dust aerosol loading and spatial distribution is obtained from remote sensing measurements which often rely on measuring the scattering or absorption of light from these particles and are thus subject to errors arising from an incomplete understanding of the scattering processes. The light scattering properties of several key mineral components of atmospheric dust have been measured at three different wavelengths in the visible. In addition, measurements of the scattering were performed for several authentic mineral dust aerosols, including Saharan sand, diatomaceous earth, Iowa loess soil, and palagonite. These samples include particles that are highly irregular in shape. Using known optical constants along with measured size distributions, simulations of the light scattering process were performed using both Mie and T-Matrix theories. Particle shapes were approximated as a distribution of spheroids for the T-Matrix calculations. It was found that the theoretical model simulations differed markedly from experimental measurements of the light scattering, particularly near the mid-range and near backscattering angles. In
10. Interactions of mineral dust with pollution and clouds: An individual-particle TEM study of atmospheric aerosol from Saudi Arabia
Pósfai, Mihály; Axisa, Duncan; Tompa, Éva; Freney, Evelyn; Bruintjes, Roelof; Buseck, Peter R.
2013-03-01
Aerosol particles from desert dust interact with clouds and influence climate on regional and global scales. The Riyadh (Saudi Arabia) aerosol campaign was initiated to study the effects of dust particles on cloud droplet nucleation and cloud properties. Here we report the results of individual-particle studies of samples that were collected from an aircraft in April 2007. We used analytical transmission electron microscopy, including energy-dispersive X-ray spectrometry, electron diffraction, and imaging techniques for the morphological, chemical, and structural characterization of the particles. Dust storms and regional background conditions were encountered during four days of sampling. Under dusty conditions, the coarse (supermicrometer) fraction resembles freshly crushed rock. The particles are almost exclusively mineral dust grains and include common rock-forming minerals, among which clay minerals, particularly smectites, are most abundant. Unaltered calcite grains also occur, indicating no significant atmospheric processing. The particles have no visible coatings but some contain traces of sulfur. The fine (submicrometer) fraction is dominated by particles of anthropogenic origin, primarily ammonium sulfate (with variable organic coating and some with soot inclusions) and combustion-derived particles (mostly soot). In addition, submicrometer, iron-bearing clay particles also occur, many of which are internally mixed with ammonium sulfate, soot, or both. We studied the relationships between the properties of the aerosol and the droplet microphysics of cumulus clouds that formed above the aerosol layer. Under dusty conditions, when a large concentration of coarse-fraction mineral particles was in the aerosol, cloud drop concentrations were lower and droplet diameters larger than under regional background conditions, when the aerosol was dominated by submicrometer sulfate particles.
11. Physical and Optical/Radiative Characteristics of Aerosol and Cloud Particles in Tropical Cirrus: Importance in Radiation Balance
NASA Technical Reports Server (NTRS)
Pueschel, R. F.; Howard, S. D.; Foster, T. C.; Hallett, J.; Arnott, W. P.; Condon, Estelle P. (Technical Monitor)
1996-01-01
Whether cirrus clouds heat or cool the Earth-atmosphere system depends on the relative importance of the cloud shortwave albedo effect and the cloud thermal greenhouse effect. Both are determined by the distribution of ice condensate with cloud particle size. The microphysics instrument package flown aboard the NASA DC-8 in TOGA/COARE included an ice crystal replicator, a 2D Greyscale Cloud Particle Probe and a Forward Scattering Spectrometer Aerosol Probe. In combination, the electro-optical instruments permitted particle size measurements between 0.5 micrometer and 2.6 millimeter diameter. Ice crystal replicas were used to validate signals from the electrooptical instruments. Both optical and scanning electron microscopy were utilized to analyze aerosol and ice particle replicas between 0.1 micrometer and several 100 micrometer diameter. In first approximation, the combined aerosol-cloud particle spectrum in several clouds followed a power law N alpha D(sup -2.5). Thus, large cloud particles carried most of the condensate mass, while small cloud and aerosol particles determined the surface area. The mechanism of formation of small particles is growth of (hygroscopic, possibly ocean-derived) aerosol particles along the Kohler curves. The concentration of small particles is higher and less variable in space and time, and their tropospheric residence time is longer, than those of large cloud particles because of lower sedimentation velocities. Small particles shift effective cloud particle radii to sizes much smaller than the mean diameter of the cloud particles. This causes an increase in shortwave reflectivity and IR emissivity, and a decrease in transmissivity. Occasionally, the cloud reflectivity increased with altitude (decreasing temperature) stronger than did cloud emissivity, yielding enhanced radiative cooling at higher altitudes. Thus, cirrus produced by deep convection in the tropics may be critical in controlling processes whereby energy from warm
12. Mass spectrometric analysis and aerodynamic properties of various types of combustion-related aerosol particles
Schneider, J.; Weimer, S.; Drewnick, F.; Borrmann, S.; Helas, G.; Gwaze, P.; Schmid, O.; Andreae, M. O.; Kirchner, U.
2006-12-01
Various types of combustion-related particles in the size range between 100 and 850 nm were analyzed with an aerosol mass spectrometer and a differential mobility analyzer. The measurements were performed with particles originating from biomass burning, diesel engine exhaust, laboratory combustion of diesel fuel and gasoline, as well as from spark soot generation. Physical and morphological parameters like fractal dimension, effective density, bulk density and dynamic shape factor were derived or at least approximated from the measurements of electrical mobility diameter and vacuum aerodynamic diameter. The relative intensities of the mass peaks in the mass spectra obtained from particles generated by a commercial diesel passenger car, by diesel combustion in a laboratory burner, and by evaporating and re-condensing lubrication oil were found to be very similar. The mass spectra from biomass burning particles show signatures identified as organic compounds like levoglucosan but also others which are yet unidentified. The aerodynamic behavior yielded a fractal dimension (Df) of 2.09 +/- 0.06 for biomass burning particles from the combustion of dry beech sticks, but showed values around three, and hence more compact particle morphologies, for particles from combustion of more natural oak. Scanning electron microscope images confirmed the finding that the beech combustion particles were fractal-like aggregates, while the oak combustion particles displayed a much more compact shape. For particles from laboratory combusted diesel fuel, a Df value of 2.35 was found, for spark soot particles, Df [approximate] 2.10. The aerodynamic properties of fractal-like particles from dry beech wood combustion indicate an aerodynamic shape factor [chi] that increases with electrical mobility diameter, and a bulk density of 1.92 g cm-3. An upper limit of [chi] [approximate] 1.2 was inferred for the shape factor of the more compact particles from oak combustion.
13. Chemical composition and sources of aerosol particles at Zeppelin Mountain (Ny Ålesund, Svalbard): An electron microscopy study
Weinbruch, Stephan; Wiesemann, David; Ebert, Martin; Schütze, Katharina; Kallenborn, Roland; Ström, Johan
2012-03-01
Aerosol particles were collected at the Zeppelin Mountain Atmospheric Research Station (474 m asl) near Ny Ålesund (Svalbard, Norway) on 27 different days between July 2007 and December 2008. The size, morphology and chemical composition of 57,617 individual particles were studied by high-resolution scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on chemical composition, morphology, mixing state and stability under electron bombardment, the particles were assigned to one of the following groups: sea salt, aged sea salt, Ca sulphates, Na sulphates, carbonates, soot, silicates, fly ashes, secondary aerosol, secondary aerosol plus sodium, secondary aerosol plus soot, mixed particles and others. Sea salt, aged sea salt, silicates and mixed particles (mixtures of sea salt, silicates and Ca sulphates) are the most abundant groups for particles with aerodynamic diameters > 0.5 μm, secondary aerosol, mixed particles and secondary aerosol with soot inclusions below 0.5 μm. Silicate fly ashes (major source coal burning) and metal fly ashes (from metallurgical high temperature processes) occur only at very low number concentrations. In contrast to previous work, the fly ash abundance is not correlated with air masses that crossed industrialized regions in Central and Eastern Europe, Scandinavia or Russia. These observations indicate a significant reduction of long-range transport of heavy metals to Svalbard. Soot (external and internally mixed with secondary aerosol) shows a pronounced seasonal pattern with a much lower abundance during summer compared to spring, autumn and winter. The soot abundance is not correlated with the air mass back-trajectories. During summer (July and August), soot was only observed when cruise ships were present in the area around Ny Ålesund (Kongsfjorden). Pronounced seasonal patterns were observed for the abundance of the mineral dust component which is generally lower in summer compared to the other seasons. The
14. Chemical Analysis of Individual Aerosols Particles by Electron Energy-Loss Spectroscopy (EELS)
Buseck, P. R.; Buseck, P. R.; Garvie, L. A.; Li, J.; Posfai, M.
2001-12-01
We use electron energy-loss spectroscopy (EELS) with a transmission electron microscope (TEM) to obtain chemical and bonding information on individual aerosol particles. EELS is ideally suited to this task because of its high spatial resolution and sensitivity to light elements such as C, N, and O. In addition, the spectral shapes provide information regarding bonding, atomic coordination and, for polyvalent elements, oxidation states. Our current focus is on carbonaceous aerosols both in the ambient air and emissions from biomass burning, with emphasis on the heterogeneous chemistry, particle structure, and chemical composition of soot particles. From the EELS spectra we were able to record for the first time, differences in composition between individual spherules within the same soot aggregate. We also found evidence of chemical variations even within individual soot spheres as small as 50 nm across. In the case of biomass burning, the most striking chemical differences are in the quantity of K, minor O and, in places, N. The quantity of elements associated with C decreases with the degree of graphitization of the soot spheres, as shown by the shapes of the C spectra and was corroborated by high-resolution TEM images of the analyzed particles. Knowledge of the degree of graphitization and quantity of associated elements is important for understanding and modeling their optical properties and in some case in source attributions.
15. Comparison of the Grimm 1.108 and 1.109 portable aerosol spectrometer to the TSI 3321 aerodynamic particle sizer for dry particles.
PubMed
Peters, Thomas M; Ott, Darrin; O'Shaughnessy, Patrick T
2006-11-01
This study compared the response of two optical particle counters with that of an aerodynamic particle sizer. The optical particle counters rely on the amount of incident light scattered at 90 degrees by a particle to measure particle number concentration by optical particle size. Two models of optical particle counters from Grimm Technologies were used: the portable aerosol spectrometer (PAS) 1.108 (0.3-20 microm in 15 channels); and the PAS 1.109 (0.2-20 microm in 30 size channels). With a substantially different operating principle from that employed by the optical particle counters, the aerodynamic particle sizer (APS) model 3321 (TSI, Inc., St Paul, MN, USA) sizes particles according to their behavior in an accelerating flow to provide particle number concentration by aerodynamic size over a slightly narrower size range (0.5-20 microm) in 52 channels. The responses of these instruments were compared for three sizes of monodisperse solid aerosols composed of polystyrene latex spheres and a polydisperse aerosol composed of Arizona test dust. The PASs provided similar results to those from the APS. However, there were systematic differences among instruments in number and mass concentration measurement that depended upon particle size.
16. Experimental Protocol to Investigate Particle Aerosolization of a Product Under Abrasion and Under Environmental Weathering.
PubMed
Shandilya, Neeraj; Le Bihan, Olivier Louis; Bressot, Christophe; Morgeneyer, Martin
2016-09-16
The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering, which is a fundamental element to the approach of nanosafety-by-design of nanostructured products for their durable development. This approach is basically a preemptive one in which the focus is put on minimizing the emission of engineered nanomaterials' aerosols during the usage phase of the product's life cycle. This can be attained by altering its material properties during its design phase without compromising with any of its added benefits. In this article, an experimental protocol is presented to investigate the nanosafety-by-design of three commercial nanostructured products with respect to their mechanical solicitation and environmental weathering. The means chosen for applying the mechanical solicitation is an abrasion process and for the environmental weathering, it is an accelerated UV exposure in the presence of humidity and heat. The eventual emission of engineered nanomaterials is studied in terms of their number concentration, size distribution, morphology and chemical composition. The purpose of the protocol is to study the emission for test samples and experimental conditions which are corresponding to real life situations. It was found that the application of the mechanical stresses alone emits the engineered nanomaterials' aerosols in which the engineered nanomaterial is always embedded inside the product matrix, thus, a representative product element. In such a case, the emitted aerosols comprise of both nanoparticles as well as microparticles. But if the mechanical stresses are coupled with the environmental weathering, the experimental protocol reveals then the eventual deterioration of the product, after a certain weathering duration, may lead to the emission of the free engineered nanomaterial aerosols too.
17. Aerosol fine fraction in the Venice Lagoon: Particle composition and sources
Prodi, F.; Belosi, F.; Contini, D.; Santachiara, G.; Di Matteo, L.; Gambaro, A.; Donateo, A.; Cesari, D.
2009-04-01
The work presents a characterisation of aerosol sampled during three campaigns conducted in the Venice Lagoon from 30 June to 21 July 2004, from 15 February to 10 March 2005 and from 8 May to 25 May 2006. The results yield information about the physical-chemical characteristics of fine aerosol, the possible sources and its fate. Sulphate (SO 42-), nitrate (NO 3-) and ammonium (NH 4+) are identified as the main water soluble components. The sum of these ions in the spring campaign 2006 varies from 51% to nearly 100% of PM2.5 fraction aerosol. NH 4+ is found to be significantly correlated to non-sea-salt sulphate (nss-SO 42-) and NO 3-, thus indicating the prevalent presence of ammonium nitrate and sulphate. The overall lack of a clear diurnal and seasonal cycle of sulphate suggests a transport from the Po Valley, while the diurnal and seasonal profile of nitrate concentrations suggests a prevalence of local generation. Sulphates from sea water through oxidation of dimethylsulfide (DMS) are not negligible (about 10% of the anthropogenic sulphate). The marine aerosol contribution to PM1 and PM2.5 fractions, calculated using Na + as a tracer of sea-salts, is low (range 1-6%). In some cases chlorine depletion is observed. The content of chlorine in the aerosol particle is mostly higher than expected for marine environments (considered on the basis of Cl -/Na + ratio). Therefore, specific sources for the element have been suggested. Oxalic acid anion, which accounts for 55% of the organic compounds examined, presents mean values 180 ng m - 3 and 161 ng m - 3 in the winter and spring campaigns, comparable with reported values in low polluted urban areas. In the winter campaign there is a high correlation between formate and acetate ( R2 = 0.93), suggesting that a common source makes a high contribution to the measured concentrations.
18. Characterization of Atmospheric Aerosol Particles from a Mining City in Southwest China Using Electron Probe microanalysis
Cheng, X.; Huang, Y.; Lu, H., III; Liu, Z., IV; Wang, N. V.
2015-12-01
Xin Cheng1, Yi Huang1*, Huilin Lu2, Zaidong Liu2, Ningming Wang21 Key Laboratory of Geological Nuclear Technology of Sichuan Province, College of Earth Science, Chengdu University of Technology, Chengdu 610059, China. ; E-mail:[email protected] 2 College of Earth Science, Chengdu University of Technology, Chengdu 610059, China. ; *Corresponding author: E-mail: [email protected] Panzhihua is a mining city located at Pan-Xi Rift valley, southwest China. It has a long industrial history of vanadium-titanium magnetite mining, iron and steel smelting, and coal-fired power plants. Atomospheric environment has been seriously contaminated with airborne paticles, which is threatening human health.The harmful effects of aerosols are dependent on certain characteristics such as microphysical properties. However, few studsies have been carried out on morphological information contained on single atmospheric particles in this area. In this study, we provide a detailed morphologically and chemically characterization of airborne particles collected at Panzhihua city in October, 2014, using a quantitative single particle analysis based on EPXMA. The results indicate that based on their chemical composition, five major types of particles were identified. Among these, aluminosilicate particles have typical spherical shapes and are produced during the high-temperature combustion; Fe-containing particles contains high level of Mn, and more likely originated from mineralogical and steel industry; Si-containing particles can originate from mineralogical source; V-Ti-Mn-containing particles are also produced by steel industry; Ca-containing particles,these particles are CaCO3, mainly from the mining of limestone mine. The results help us on tracing and partitioning different sources of atomospheric particles in the industrial area. Fig.1 Fe-rich shperical particles
19. Aerosol processing of fine Ag:(Bi,Pb)2223 composite particles
Mancic, Lidija; Marinkovic, Bojan; Vulic, Predrag; Milosevic, Olivera
2004-08-01
This paper represents an attempt in the obtaining of metal-ceramic composite precursor powders in the Ag:Bi-based superconductor system with uniform distribution of comprised phases through spray pyrolysis method. The process involves aerosol formation ultrasonically (800 kHz) from the urea-modified nitrates precursor solution (for the fixed cation ratio Bi:Pb:Sr:Ca:Cu=1.8:0.2:2:2:3 and for the Ag fraction of 20 wt.%) and control over the aerosol decomposition united with self-combustion of droplets in a high-temperature tubular flow reactor in the temperature range up to 820 °C. Following the initial attempts in providing of the 2223 phase high contents, particles were additionally calcined for 2 h in air and oxygen, at 825 and 810 °C respectively. Structure, morphology and compositional stoichiometry of synthesized powders were followed in accordance to various analysis methods (XRD, DTA, SEM and EDS).
20. Springtime precipitation effects on the abundance of fluorescent biological aerosol particles and HULIS in Beijing
Yue, Siyao; Ren, Hong; Fan, Songyun; Sun, Yele; Wang, Zifa; Fu, Pingqing
2016-07-01
Bioaerosols and humic-like substances (HULIS) are important components of atmospheric aerosols, which can affect regional climate by acting as cloud condensation nuclei and some of which can damage human health. Up to date, release of bioaerosols and HULIS initiated by precipitation is still poorly understood. Here we present different release processes for bioaerosols, non-bioaerosols and HULIS during a precipitation event in Beijing, China. Large fungal-spore-like aerosols were emitted at the onset and later weak stage of precipitation, the number concentration of which increased by more than two folds, while the number concentration of bacteria-like particles doubled when the precipitation strengthened. Besides, a good correlation between protein-like substances that were measured simultaneously by on-line and off-line fluorescence techniques consolidated their applications to measure bioaerosols. Furthermore, our EEM results suggest that the relative contribution of water-soluble HULIS to microbial materials was enhanced gradually by the rain event.
1. Hygroscopicity and CCN activity of atmospheric aerosol particles and their relation to organics: Characteristics of urban aerosols in Nagoya, Japan
Kawana, Kaori; Nakayama, Tomoki; Mochida, Michihiro
2016-04-01
The size-resolved distributions of hygroscopic growth factor g and the ratios of cloud condensation nuclei (CCN) to condensation nuclei of atmospheric aerosols were investigated in Nagoya, Japan. The average of the distributions of g at 85% relative humidity was bimodal. The size-resolved mean κ derived from g showed an increasing trend with diameter: 0.17-0.33 at 24-359 nm. The κ values calculated from CCN activation curves were 37% higher than those derived from g. Only 9% of the 37% difference is explained by the difference in the κ of inorganics under subsaturated and supersaturated conditions, suggesting a contribution of organics to the remaining 28% difference. The size-averaged κ of organics (κorg) was calculated as 0.14 and 0.19 by two different methods. The number fractions of CCN predicted from the hygroscopicity data over the range of 24-359 nm are loosely consistent with those observed if the size- and time-averaged g is applied to all particles (differences: -30% to +10%). This consistency improves if size- and time-resolved g and g distribution are used (differences: -19% to -3%). Whereas the number fractions of CCN predicted from the composition data are greatly underestimated if organics are assumed to be insoluble (differences: -64% to -45%), they are more consistent if κorg of 0.14 or 0.19 is applied (differences: -10% to +14%). The results demonstrate the importance of the dependence of the g of particles on time and particle size and the hygroscopicity of organics for CCN number concentrations in the urban atmosphere.
2. Self-assembly of marine exudate particles and their impact on the CCN properties of nascent marine aerosol
Schill, S.; Zimmermann, K.; Ryder, O. S.; Campbell, N.; Collins, D. B.; Gianneschi, N.; Bertram, T. H.
2013-12-01
Spontaneous self-assembly of marine exudate particles has previously been observed in filtered seawater samples. The chemicophysical properties of these particles may alter the chemical composition and CCN properties of nascent marine aerosol, yet to date simultaneous measurement of seawater exudate particle formation rates and number distributions, with aerosol particle formation rates and CCN activity are lacking. Here, we use a novel Marine Aerosol Reference Tank (MART) system to experimentally mimic a phytoplankton bloom via sequential addition of biological surrogates, including sterol, galactose, lipopolysaccharide, BSA protein, and dipalmitoylphosphatidylcholine. Nascent sea-spray aerosol are generated in the MART system via a continuous plunging waterfall. Exudate particle assembly in the water is monitored via dynamic light scattering (DLS) and transmission electron microscopy (TEM) to obtain both the assembly kinetics of the particles as well as particle number distributions Simultaneous characterization of both particle production rates and super-saturated particle hygroscopicity are also discussed. This study permits analysis of the controlling role of the molecular composition of dissolved organic carbon in setting the production rates of colloidal material in the surface oceans.
3. Measurements of extinction by aerosol particles in the near-infrared using continuous wave cavity ring-down spectroscopy.
PubMed
Mellon, Daniel; King, Simon J; Kim, Jin; Reid, Jonathan P; Orr-Ewing, Andrew J
2011-02-10
Cavity ring-down spectroscopy using a fiber-coupled continuous wave distributed feedback laser at a wavelength of 1520 nm has been used to measure extinction of light by samples of nearly monodisperse aerosol particles <1 μm in diameter. A model is tested for the analysis of the sample extinction that is based on the Poisson statistics of the number of particles within the intracavity laser beam: variances of measured extinction are used to derive values of the scattering cross section for size-selected aerosol particles, without need for knowledge of the particle number density or sample length. Experimental parameters that influence the performance of the CRD system and the application and limitations of the statistical model are examined in detail. Determinations are reported of the scattering cross sections for polystyrene spheres (PSSs), sodium chloride, and ammonium sulfate, and, for particles greater than 500 nm in diameter, are shown to be in agreement with the corresponding values calculated using Mie theory or Discrete Dipole Approximation methods. For smaller particles, the experimentally derived values of the scattering cross section are larger than the theoretical predictions, and transmission of a small fraction of larger particles into the cavity is argued to be responsible for this discrepancy. The effects of cubic structure on the determination of optical extinction efficiencies of sodium chloride aerosol particles are examined. Values are reported for the real components of the refractive indices at 1520 nm of PSS, sodium chloride, and ammonium sulfate aerosol particles.
4. Aerosols in Santiago de Chile: A study using receptor modeling with X-ray fluorescence and single particle analysis
Rojas, Carlos M.; Artaxo, Paulo; Van Grieken, René
Between 15 January and 26 February 1987, 51 fine and coarse mode aerosol samples were collected at the Universidad de Santiago de Chile Planetarium using a dichotomous sampler. The samples were analyzed by X-ray fluorescence for up to 17 elements (Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb). Aerosol particles were individually studied by Electron Probe Microanalysis (EPMA) and Laser Microprobe Mass Analysis (LAMMA). The data set consisting of aerosol elemental concentrations and meteorological variables was subjected to Principal Factor Analysis (PFA), allowing the identification of six fine mode particle source classes (soil, industrial, sulfate particles, traffic, residual oil, wood-burnings), and five coarse mode particle source classes (soil, industrial, traffic, residual oil, sulfate particles). Both PFA solutions explained about 81 and 90% of the total variance in the data set, respectively. The regression of elemental mass concentrations on the Absolute Principal Factor Scores allowed the estimation of the contribution of the different source classes to the Santiago aerosol. Within the fine fraction, secondary SO 42- particles were responsible for about 49% of the fine mode aerosol mass concentration, while 26, 13, 6.4 and 5.6% were attributed to wood-burning/car exhausts, residual oil combustion, soil dust/metallurgical, and soil dust/wood-burning releases, respectively. The coarse fraction source apportionment was mainly dominated by soil dust, accounting for 74% of the coarse mode aerosol mass concentration. A composite of soil dust and industrial release accounted for 13%; a composite of secondary sulfates contributed with 9%; a composite of soil dust and automotive emissions, and secondary sulfates were responsible for 4 and 0.03% of the coarse aerosol mass concentration, respectively. EPMA results are in satisfactory agreement with those from the bulk analysis and allowed the identification of eight particle types in both fine
5. Emissions and Characteristics of Ice Nucleating Particles Associated with Laboratory Generated Nascent Sea Spray Aerosol
McCluskey, C. S.; Hill, T. C. J.; Beall, C.; Sultana, C. M.; Moore, K.; Cornwell, G.; Lee, C.; Al-Mashat, H.; Laskina, O.; Trueblood, J.; Grassian, V. H.; Prather, K. A.; Kreidenweis, S. M.; DeMott, P. J.
2015-12-01
Accurate emission rates and activity spectra of atmospheric ice nucleating particles (INPs) are required for proper representation of aerosol-cloud interactions in atmospheric modeling studies. However, few investigations have quantified or characterized oceanic INP emissions. In conjunction with the Center for Aerosol Impacts on the Climate and the Environment, we have directly measured changes in INP emissions and properties of INPs from nascent sea spray aerosol (SSA) through the evolution of phytoplankton blooms. Multiple offline and online instruments were used to monitor aerosol chemistry and size, and bulk water characteristics during two phytoplankton bloom experiments. Two methods were utilized to monitor the number concentrations of INPs from 0 to -34 °C: The online CSU continuous flow diffusion chamber (CFDC) and collections processed offline using the CSU ice spectrometer. Single particle analyses were performed on ice crystal residuals downstream of the CFDC, presumed to be INPs, via scanning transmission electron microscopy (STEM) and Raman microspectroscopy. Preliminary results indicate that laboratory-generated nascent SSA corresponds to number concentrations of INPs that are generally consistent with open ocean regions, based on current knowledge. STEM analyses revealed that the sizes of ice crystal residuals that were associated with nascent SSA ranged from 0.3 to 2.5 μm. Raman microspectroscopy analysis of 1 μm sized residuals found a variety of INP identities, including long chain organics, diatom fragments and polysaccharides. Our data suggest that biological processes play a significant role in ocean INP emissions by generating the species and compounds that were identified during these studies.
6. Impact of interannual variations in aerosol particle sources on orographic precipitation over California's Central Sierra Nevada
Creamean, J. M.; Ault, A. P.; White, A. B.; Neiman, P. J.; Ralph, F. M.; Minnis, P.; Prather, K. A.
2015-01-01
Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009-2011), the variability and associated impacts of different aerosol sources on precipitation were investigated in the California Sierra Nevada using an aerosol time-of-flight mass spectrometer for precipitation chemistry, S-band profiling radar for precipitation classification, remote sensing measurements of cloud properties, and surface meteorological measurements. The composition of insoluble residues in precipitation samples collected at a surface site contained mostly local biomass burning and long-range transported dust and biological particles (2009), local sources of biomass burning and pollution (2010), and long-range transport from distant sources (2011). Although differences in the sources were observed from year-to-year, the most consistent source of dust and biological residues were associated with storms consisting of deep convective cloud systems with significant quantities of precipitation initiated in the ice phase. Further, biological residues were dominant (up to 40%) during storms with relatively warm cloud temperatures (up to -15 °C), supporting the important role bioparticles can play as ice nucleating particles. On the other hand, lower percentages of residues from local biomass burning and pollution were observed over the three winter seasons (on average 31 and 9%, respectively). When precipitation quantities were relatively low, these residues most likely served as CCN, forming smaller more numerous cloud droplets at the base of shallow cloud systems, and resulting in less efficient riming processes. The correlation between the source of aerosols within clouds and precipitation type and quantity will be further probed in models to understand the
7. Effect of particle-fiber friction coefficient on ultrafine aerosol particles clogging in nanofiber based filter
Sambaer, Wannes; Zatloukal, Martin; Kimmer, Dusan
2013-04-01
Realistic SEM image based 3D filter model considering transition/free molecular flow regime, Brownian diffusion, aerodynamic slip, particle-fiber and particle-particle interactions together with a novel Euclidian distance map based methodology for the pressure drop calculation has been utilized for a polyurethane nanofiber based filter prepared via electrospinning process in order to more deeply understand the effect of particle-fiber friction coefficient on filter clogging and basic filter characteristics. Based on the performed theoretical analysis, it has been revealed that the increase in the fiber-particle friction coefficient causes, firstly, more weaker particle penetration in the filter, creation of dense top layers and generation of higher pressure drop (surface filtration) in comparison with lower particle-fiber friction coefficient filter for which deeper particle penetration takes place (depth filtration), secondly, higher filtration efficiency, thirdly, higher quality factor and finally, higher quality factor sensitivity to the increased collected particle mass. Moreover, it has been revealed that even if the particle-fiber friction coefficient is different, the cake morphology is very similar.
8. Criteria for significance of simultaneous presence of both condensible vapors and aerosol particles on mass transfer (deposition) rates
NASA Technical Reports Server (NTRS)
Gokoglu, S. A.
1987-01-01
The simultaneous presence of aerosol particles and condensible vapors in a saturated boundary layer which may affect deposition rates to subcooled surfaces because of vapor-particle interactions is discussed. Scavenging of condensible vapors by aerosol particles may lead to increased particle size and decreased vapor mass fraction, which alters both vapor and particle deposition rates. Particles, if sufficiently concentrated, may also coagulate. Criteria are provided to assess the significance of such phenomena when particles are already present in the mainstream and are not created inside the boundary layer via homogeneous nucleation. It is determined that there is direct proportionality with: (1) the mass concentration of both condensible vapors and aerosol particles; and (2) the square of the boundary layer thickness to particle diameter ratio (delta d sub p) square. Inverse proportionality was found for mainstream to surface temperature difference if thermophoresis dominates particle transport. It is concluded that the square of the boundary layer thickness to particle diameter ratio is the most critical factor to consider in deciding when to neglect vapor-particle interactions.
9. Criteria for significance of simultaneous presence of both condensible vapors and aerosol particles on mass transfer (deposition) rates
NASA Technical Reports Server (NTRS)
Gokoglu, S. A.
1986-01-01
The simultaneous presence of aerosol particles and condensible vapors in a saturated boundary layer which may affect deposition rates to subcooled surfaces because of vapor-particle interactions is discussed. Scavenging of condensible vapors by aerosol particles may lead to increased particle size and decreased vapor mass fraction, which alters both vapor and particle deposition rates. Particles, if sufficiently concentrated, may also coagulate. Criteria are provided to assess the significance of such phenomena when particles are already present in the mainstream and are not created inside the boundary layer via homogeneous nucleation. It is determined that there is direct proportionality with: (1) the mass concentration of both condensible vapors and aerosol particles; and (2) the square of the boundary layer thickness to particle diameter ratio (delta d sub p) square. Inverse proportionality was found for mainstream to surface temperature difference if thermophoresis dominates particle transport. It is concluded that the square of the boundary layer thickness to particle diameter ratio is the most critical factor to consider in deciding when to neglect vapor-particle interactions.
10. Single-particle aerosol mass spectrometry for the detection and identification of chemical warfare agent simulants.
PubMed
Martin, Audrey N; Farquar, George R; Frank, Matthias; Gard, Eric E; Fergenson, David P
2007-08-15
Single-particle aerosol mass spectrometry (SPAMS) was used for the real-time detection of liquid nerve agent simulants. A total of 1000 dual-polarity time-of-flight mass spectra were obtained for micrometer-sized single particles each of dimethyl methyl phosphonate, diethyl ethyl phosphonate, diethyl phosphoramidate, and diethyl phthalate using laser fluences between 0.58 and 7.83 nJ/microm2, and mass spectral variation with laser fluence was studied. The mass spectra obtained allowed identification of single particles of the chemical warfare agent (CWA) simulants at each laser fluence used although lower laser fluences allowed more facile identification. SPAMS is presented as a promising real-time detection system for the presence of CWAs.
11. Airborne measurements of cloud forming nuclei and aerosol particles at Kennedy Space Center, Florida
NASA Technical Reports Server (NTRS)
Radke, L. F.; Langer, G.; Hindman, E. E., II
1978-01-01
Results of airborne measurements of the sizes and concentrations of aerosol particles, ice nuclei, and cloud condensation nuclei that were taken at Kennedy Space Center, Florida, are presented along with a detailed description of the instrumentation and measuring capabilities of the University of Washington airborne measuring facility (Douglas B-23). Airborne measurements made at Ft. Collins, Colorado, and Little Rock, Arkansas, during the ferry of the B-23 are presented. The particle concentrations differed significantly between the clean air over Ft. Collins and the hazy air over Little Rock and Kennedy Space Center. The concentrations of cloud condensation nuclei over Kennedy Space Center were typical of polluted eastern seaboard air. Three different instruments were used to measure ice nuclei: one used filters to collect the particles, and the others used optical and acoustical methods to detect ice crystals grown in portable cloud chambers. A comparison of the ice nucleus counts, which are in good agreement, is presented.
12. Possible effect of extreme solar energetic particle event of 20 January 2005 on polar stratospheric aerosols: direct observational evidence
Mironova, I. A.; Usoskin, I. G.; Kovaltsov, G. A.; Petelina, S. V.
2012-01-01
Energetic cosmic rays are the main source of ionization of the low-middle atmosphere, leading to associated changes in atmospheric properties. Via the hypothetical influence of ionization on aerosol growth and facilitated formation of clouds, this may be an important indirect link relating solar variability to climate. This effect is highly debated, however, since the proposed theoretical mechanisms still remain illusive and qualitative, and observational evidence is inconclusive and controversial. Therefore, important questions regarding the existence and magnitude of the effect, and particularly the fraction of aerosol particles that can form and grow, are still open. Here we present empirical evidence of the possible effect caused by cosmic rays upon polar stratospheric aerosols, based on a case study of an extreme solar energetic particle (SEP) event of 20 January 2005. Using aerosol data obtained over polar regions from different satellites with optical instruments that were operating during January 2005, such as the Stratospheric Aerosol and Gas Experiment III (SAGE III), and Optical Spectrograph and Infrared Imaging System (OSIRIS), we found a significant simultaneous change in aerosol properties in both the Southern and Northern Polar regions in temporal association with the SEP event. We speculate that ionization of the atmosphere, which was abnormally high in the lower stratosphere during the extreme SEP event, might have led to formation of new particles and/or growth of preexisting ultrafine particles in the polar stratospheric region. However, a detailed interpretation of the effect is left for subsequent studies. This is the first time high vertical resolution measurements have been used to discuss possible production of stratospheric aerosols under the influence of cosmic ray induced ionization. The observed effect is marginally detectable for the analyzed severe SEP event and can be undetectable for the majority of weak-moderate events. The present
13. Long-term Chemical Characterization of Submicron Aerosol Particles in the Amazon Forest - ATTO Station
Carbone, S.; Brito, J.; Rizzo, L. V.; Holanda, B. A.; Cirino, G. G.; Saturno, J.; Krüger, M. L.; Pöhlker, C.; Ng, N. L.; Xu, L.; Andreae, M. O.; Artaxo, P.
2015-12-01
The study of the chemical composition of aerosol particles in the Amazon forest represents a step forward to understand the strong coupling between the atmosphere and the forest. For this reason submicron aerosol particles were investigated in the Amazon forest, where biogenic and anthropogenic aerosol particles coexist at the different seasons (wet/dry). The measurements were performed at the ATTO station, which is located about 150 km northeast of Manaus. At ATTO station the Aerosol chemical speciation monitor (ACSM, Aerodyne) and the Multiangle absorption photometer (MAAP, Thermo 5012) have been operated continuously from March 2014 to July 2015. In this study, long-term measurements (near-real-time, ~30 minutes) of PM1 chemical composition were investigated for the first time in this environment.The wet season presented lower concentrations than the dry season (~5 times). In terms of chemical composition, both seasons were dominated by organics (75 and 63%) followed by sulfate (11 and 13%). Nitrate presented different ratio values between the mass-to-charges 30 to 46 (main nitrate fragments) suggesting the presence of nitrate as inorganic and organic nitrate during both seasons. The results indicated that about 75% of the nitrate signal was from organic nitrate during the dry season. In addition, several episodes with elevated amount of chloride, likely in the form of sea-salt from the Atlantic Ocean, were observed during the wet season. During those episodes, chloride comprised up to 7% of the PM1. During the dry season, chloride was also observed; however, with different volatility, which suggested that Chloride was present in different form and source. Moreover, the constant presence of sulfate and BC during the wet season might be related to biomass burning emissions from Africa. BC concentration was 2.5 times higher during the dry season. Further characterization of the organic fraction was accomplished with the positive matrix factorization (PMF), which
14. Understanding hygroscopic growth and phase transformation of aerosols using single particle Raman spectroscopy in an electrodynamic balance.
PubMed
Lee, Alex K Y; Ling, T Y; Chan, Chak K
2008-01-01
Hygroscopic growth is one of the most fundamental properties of atmospheric aerosols. By absorbing or evaporating water, an aerosol particle changes its size, morphology, phase, chemical composition and reactivity and other parameters such as its refractive index. These changes affect the fate and the environmental impacts of atmospheric aerosols, including global climate change. The ElectroDynamic Balance (EDB) has been widely accepted as a unique tool for measuring hygroscopic properties and for investigating phase transformation of aerosols via single particle levitation. Coupled with Raman spectroscopy, an EDB/Raman system is a powerful tool that can be used to investigate both physical and chemical changes associated with the hygroscopic properties of individually levitated particles under controlled environments. In this paper, we report the use of an EDB/Raman system to investigate (1) contact ion pairs formation in supersaturated magnesium sulfate solutions; (2) phase transformation in ammonium nitrate/ammonium sulfate mixed particles; (3) hygroscopicity of organically coated inorganic aerosols; and (4) heterogeneous reactions altering the hygroscopicity of organic aerosols.
15. The effect of viscosity and diffusion on the HO2 uptake by sucrose and secondary organic aerosol particles
Lakey, Pascale S. J.; Berkemeier, Thomas; Krapf, Manuel; Dommen, Josef; Steimer, Sarah S.; Whalley, Lisa K.; Ingham, Trevor; Baeza-Romero, Maria T.; Pöschl, Ulrich; Shiraiwa, Manabu; Ammann, Markus; Heard, Dwayne E.
2016-10-01
We report the first measurements of HO2 uptake coefficients, γ, for secondary organic aerosol (SOA) particles and for the well-studied model compound sucrose which we doped with copper(II). Above 65 % relative humidity (RH), γ for copper(II)-doped sucrose aerosol particles equalled the surface mass accommodation coefficient α = 0.22 ± 0.06, but it decreased to γ = 0.012 ± 0.007 upon decreasing the RH to 17 %. The trend of γ with RH can be explained by an increase in aerosol viscosity and the contribution of a surface reaction, as demonstrated using the kinetic multilayer model of aerosol surface and bulk chemistry (KM-SUB). At high RH the total uptake was driven by reaction in the near-surface bulk and limited by mass accommodation, whilst at low RH it was limited by surface reaction. SOA from two different precursors, α-pinene and 1,3,5-trimethylbenzene (TMB), was investigated, yielding low uptake coefficients of γ < 0.001 and γ = 0.004 ± 0.002, respectively. It is postulated that the larger values measured for TMB-derived SOA compared to α-pinene-derived SOA are either due to differing viscosity, a different liquid water content of the aerosol particles, or an HO2 + RO2 reaction occurring within the aerosol particles.
16. Particle Deposition in a Child Respiratory Tract Model: In Vivo Regional Deposition of Fine and Ultrafine Aerosols in Baboons
PubMed Central
Albuquerque-Silva, Iolanda; Vecellio, Laurent; Durand, Marc; Avet, John; Le Pennec, Déborah; de Monte, Michèle; Montharu, Jérôme; Diot, Patrice; Cottier, Michèle; Dubois, Francis; Pourchez, Jérémie
2014-01-01
To relate exposure to adverse health effects, it is necessary to know where particles in the submicron range deposit in the respiratory tract. The possibly higher vulnerability of children requires specific inhalation studies. However, radio-aerosol deposition experiments involving children are rare because of ethical restrictions related to radiation exposure. Thus, an in vivo study was conducted using three baboons as a child respiratory tract model to assess regional deposition patterns (thoracic region vs. extrathoracic region) of radioactive polydisperse aerosols ([d16–d84], equal to [0.15 µm–0.5 µm], [0.25 µm–1 µm], or [1 µm–9 µm]). Results clearly demonstrated that aerosol deposition within the thoracic region and the extrathoraic region varied substantially according to particle size. High deposition in the extrathoracic region was observed for the [1 µm–9 µm] aerosol (72%±17%). The [0.15 µm–0.5 µm] aerosol was associated almost exclusively with thoracic region deposition (84%±4%). Airborne particles in the range of [0.25 µm–1 µm] showed an intermediate deposition pattern, with 49%±8% in the extrathoracic region and 51%±8% in the thoracic region. Finally, comparison of baboon and human inhalation experiments for the [1 µm–9 µm] aerosol showed similar regional deposition, leading to the conclusion that regional deposition is species-independent for this airborne particle sizes. PMID:24787744
17. Particle deposition in a child respiratory tract model: in vivo regional deposition of fine and ultrafine aerosols in baboons.
PubMed
Albuquerque-Silva, Iolanda; Vecellio, Laurent; Durand, Marc; Avet, John; Le Pennec, Déborah; de Monte, Michèle; Montharu, Jérôme; Diot, Patrice; Cottier, Michèle; Dubois, Francis; Pourchez, Jérémie
2014-01-01
To relate exposure to adverse health effects, it is necessary to know where particles in the submicron range deposit in the respiratory tract. The possibly higher vulnerability of children requires specific inhalation studies. However, radio-aerosol deposition experiments involving children are rare because of ethical restrictions related to radiation exposure. Thus, an in vivo study was conducted using three baboons as a child respiratory tract model to assess regional deposition patterns (thoracic region vs. extrathoracic region) of radioactive polydisperse aerosols ([d16-d84], equal to [0.15 µm-0.5 µm], [0.25 µm-1 µm], or [1 µm-9 µm]). Results clearly demonstrated that aerosol deposition within the thoracic region and the extrathoraic region varied substantially according to particle size. High deposition in the extrathoracic region was observed for the [1 µm-9 µm] aerosol (72% ± 17%). The [0.15 µm-0.5 µm] aerosol was associated almost exclusively with thoracic region deposition (84% ± 4%). Airborne particles in the range of [0.25 µm-1 µm] showed an intermediate deposition pattern, with 49% ± 8% in the extrathoracic region and 51% ± 8% in the thoracic region. Finally, comparison of baboon and human inhalation experiments for the [1 µm-9 µm] aerosol showed similar regional deposition, leading to the conclusion that regional deposition is species-independent for this airborne particle sizes.
18. Method and apparatus for aerosol-particle absorption spectroscopy. [DOE patent application
SciTech Connect
Campillo, A.J.; Lin, H.B.
1981-06-25
A method and apparatus are described for determining the absorption spectra, and other properties, of aerosol particles. A heating beam source provides a beam of electromagnetic energy which is scanned through the region of the spectrum which is of interest. Particles exposed to the heating beam which have absorption bands within the band width of the heating beam absorb energy from the beam. The particles are also illuminated by light of a wave length such that the light is scattered by the particles. The absorption spectra of the particles can thus be determined from an analysis of the scattered light since the absorption of energy by the particles will affect the way the light is scattered. Preferably the heating beam is modulated to simplify the analysis of the scattered light. In one embodiment the heating beam is intensity modulated so that the scattered light will also be intensity modulated when the particles absorb energy. In another embodiment the heating beam passes through an interferometer and the scattered light reflects the Fourier Transform of the absorption spectra.
19. Hygroscopicity of internally mixed multi-component aerosol particles of atmospheric relevance
Liu, Qifan; Jing, Bo; Peng, Chao; Tong, Shengrui; Wang, Weigang; Ge, Maofa
2016-01-01
The hygroscopic properties of two water-soluble organic compounds (WSOCs) relevant to urban haze pollution (phthalic acid and levoglucosan) and their internally mixtures with inorganic salts (ammonium sulfate and ammonium nitrate) are investigated using a hygroscopicity tandem differential mobility analyzer (H-TDMA) system. The multi-component particles uptake water gradually in the range 5-90% relative humidity (RH). The experimental results are compared with the thermodynamic model predictions. For most mixtures, Extended Aerosol Inorganic Model (E-AIM) predictions agree well with the measured growth factors. The hygroscopic growth of mixed particles can be well described by the Zdanovskii-Stokes-Robinson (ZSR) relation as long as the mixed particles are completely liquid. ZSR calculations underestimate the water uptake of mixed particles at moderate RH due to the partial dissolution of ammonium sulfate in the organic and ammonium nitrate solution in this RH region. The phase of ammonium nitrate in the initial dry particles changes dramatically with the composition of mixtures. The presence of organics in the mixed particles can inhibit the crystallization of ammonium nitrate during the drying process and results in water uptake at low RH (RH < 60%). These results demonstrate that certain representative WSOCs can substantially influence the hygroscopicity of inorganic salts and overall water uptake of particles.
20. Impacts of aerosol particles on the microphysical and radiative properties of stratocumulus clouds over the southeast Pacific Ocean
Twohy, C. H.; Anderson, J. R.; Toohey, D. W.; Andrejczuk, M.; Adams, A.; Lytle, M.; George, R. C.; Wood, R.; Saide, P.; Spak, S.; Zuidema, P.; Leon, D.
2013-03-01
The southeast Pacific Ocean is covered by the world's largest stratocumulus cloud layer, which has a strong impact on ocean temperatures and climate in the region. The effect of anthropogenic sources of aerosol particles on the stratocumulus deck was investigated during the VOCALS field experiment. Aerosol measurements below and above cloud were made with a ultra-high sensitivity aerosol spectrometer and analytical electron microscopy. In addition to more standard in-cloud measurements, droplets were collected and evaporated using a counterflow virtual impactor (CVI), and the non-volatile residual particles were analyzed. Many flights focused on the gradient in cloud properties on an E-W track along 20° S from near the Chilean coast to remote areas offshore. Mean statistics, including their significance, from eight flights and many individual legs were compiled. Consistent with a continental source of cloud condensation nuclei, below-cloud accumulation-mode aerosol and droplet number concentration generally decreased from near shore to offshore. Single particle analysis was used to reveal types and sources of the enhanced particle number that influence droplet concentration. While a variety of particle types were found throughout the region, the dominant particles near shore were partially neutralized sulfates. Modeling and chemical analysis indicated that the predominant source of these particles in the marine boundary layer along 20° S was anthropogenic pollution from central Chilean sources, with copper smelters a relatively small contribution. Cloud droplets were smaller in regions of enhanced particles near shore. However, physically thinner clouds, and not just higher droplet number concentrations from pollution, both contributed to the smaller droplets. Satellite measurements were used to show that cloud albedo was highest 500-1000 km offshore, and actually slightly lower closer to shore due to the generally thinner clouds and lower liquid water paths
1. Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried cyclosporine A multifunctional particles for dry powder inhalation aerosol delivery.
PubMed
Wu, Xiao; Zhang, Weifen; Hayes, Don; Mansour, Heidi M
2013-01-01
In this systematic and comprehensive study, inhalation powders of the polypeptide immunosuppressant drug - cyclosporine A - for lung delivery as dry powder inhalers (DPIs) were successfully designed, developed, and optimized. Several spray drying pump rates were rationally chosen. Comprehensive physicochemical characterization and imaging was carried out using scanning electron microscopy, hot-stage microscopy, differential scanning calorimetry, powder X-ray diffraction, Karl Fischer titration, laser size diffraction, and gravimetric vapor sorption. Aerosol dispersion performance was conducted using a next generation impactor with a Food and Drug Administration-approved DPI device. These DPIs displayed excellent aerosol dispersion performance with high values in emitted dose, respirable fraction, and fine particle fraction. In addition, novel multifunctional inhalation aerosol powder formulations of cyclosporine A with lung surfactant-mimic phospholipids were also successfully designed and developed by advanced organic solution cospray drying in closed mode. The lung surfactantmimic phospholipids were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-snglycero- 3-(phosphor-rac-1-glycerol). These cyclosporine A lung surfactant-mimic aerosol powder formulations were comprehensively characterized. Powder X-ray diffraction and differential scanning calorimetry confirmed that the phospholipid bilayer structure in the solid state was preserved following advanced organic solution spray drying in closed mode. These novel multifunctional inhalation powders were optimized for DPI delivery with excellent aerosol dispersion performance and high aerosol performance parameters.
2. Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried cyclosporine A multifunctional particles for dry powder inhalation aerosol delivery
PubMed Central
Wu, Xiao; Zhang, Weifen; Hayes, Don; Mansour, Heidi M
2013-01-01
In this systematic and comprehensive study, inhalation powders of the polypeptide immunosuppressant drug – cyclosporine A – for lung delivery as dry powder inhalers (DPIs) were successfully designed, developed, and optimized. Several spray drying pump rates were rationally chosen. Comprehensive physicochemical characterization and imaging was carried out using scanning electron microscopy, hot-stage microscopy, differential scanning calorimetry, powder X-ray diffraction, Karl Fischer titration, laser size diffraction, and gravimetric vapor sorption. Aerosol dispersion performance was conducted using a next generation impactor with a Food and Drug Administration-approved DPI device. These DPIs displayed excellent aerosol dispersion performance with high values in emitted dose, respirable fraction, and fine particle fraction. In addition, novel multifunctional inhalation aerosol powder formulations of cyclosporine A with lung surfactant-mimic phospholipids were also successfully designed and developed by advanced organic solution cospray drying in closed mode. The lung surfactantmimic phospholipids were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-snglycero- 3-(phosphor-rac-1-glycerol). These cyclosporine A lung surfactant-mimic aerosol powder formulations were comprehensively characterized. Powder X-ray diffraction and differential scanning calorimetry confirmed that the phospholipid bilayer structure in the solid state was preserved following advanced organic solution spray drying in closed mode. These novel multifunctional inhalation powders were optimized for DPI delivery with excellent aerosol dispersion performance and high aerosol performance parameters. PMID:23569375
3. Aerosol-CFD modelling of ultrafine and black carbon particle emission, dilution, and growth near roadways | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.79929518699646, "perplexity": 5743.299601374221}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187820556.7/warc/CC-MAIN-20171017013608-20171017033608-00216.warc.gz"} |
https://www.transtutors.com/questions/the-drag-coefficient-for-a-sphere-at-reynolds-numbers-less-than-100-may-be-approxima-5128768.htm | The drag coefficient for a sphere at Reynolds numbers less than 100 may be approximatedby CD...
The drag coefficient for a sphere at Reynolds numbers less than 100 may be approximatedby CD =bRe-1, where b is a constant. Assuming that the Colburn analogybetween heat transfer and fluid friction applies, derive an expression for the heatloss from a sphere of diameter d and temperature Ts, released from rest and allowedto fall in a fluid of temperature T8. (Obtain an expression for the heat lost betweenthe time the sphere is released and the time it reaches some velocity
v. Assume thatthe Reynolds number is less than 100 during this time and that the sphere remainsat a constant temperature.) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9227914214134216, "perplexity": 565.1302369464313}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875143373.18/warc/CC-MAIN-20200217205657-20200217235657-00303.warc.gz"} |
https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Book%3A_Introductory_Chemistry_(CK-12)/15%3A_Water/15.03%3A_Physical_Properties_of_Water | # 15.3: Physical Properties of Water
Water loss to the atmosphere is a significant problem in many parts of the world. When water supplies are low, anything that can be done to decrease water loss is important for farmers. An evaporation pan can be used to measure how fast water evaporates in a given location. This information can be used as part of projects to develop ways to cut down on evaporation and increase the amount of usable water in a region.
## Properties of Water
Compared to other molecular compounds of relatively low molar mass, ice melts at a very high temperature. A great deal of energy is required to break apart the hydrogen-bonded network of ice and return it to the liquid state. Likewise, the boiling point of water is very high. Most molecular compounds of similar molar mass are gases at room temperature.
### Surface Tension
Water has a high surface tension (attraction between molecules at the surface of a liquid) because of its hydrogen bonding. Liquids that cannot hydrogen bond do not exhibit nearly as much surface tension. Surface tension can be seen by the curved meniscus that forms when water is in a thin column such as a graduated cylinder or a buret.
### Vapor Pressure
The vapor pressure of a liquid is the pressure of the vapor produced by evaporation of a liquid or solid above the liquid or solid in a closed container. The hydrogen bonding between liquid water molecules explains why water has an unusually low vapor pressure. Relatively few molecules of water are capable of escaping the surface of the liquid and enter the vapor phase. Evaporation is slow and thus the vapor exerts a low pressure in a closed container. Low vapor pressure is an important physical property of water, since lakes, oceans, and other large bodies of water would all tend to evaporate much more quickly otherwise.
Vapor pressure is influenced by temperature. As the temperature increases, more molecules are released from the surface of the liquid. This increases movement above the liquid surface, increasing the pressure in the vapor stage. The image below illustrates the effect of temperature on vapor pressure.
## Summary
• Water has high surface tension because of extensive hydrogen bonding.
• The vapor pressure of water is low due to hydrogen bonding.
• Vapor pressure increases as temperature increases.
## Contributors
• CK-12 Foundation by Sharon Bewick, Richard Parsons, Therese Forsythe, Shonna Robinson, and Jean Dupon. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8959147930145264, "perplexity": 569.1570954918144}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987817685.87/warc/CC-MAIN-20191022104415-20191022131915-00491.warc.gz"} |
https://en.wikisource.org/wiki/The_American_Practical_Navigator/Chapter_13 | # The American Practical Navigator/Chapter 13
### 1300. Introduction
Radar determines distance to an object by measuring the time required for a radio signal to travel from a transmitter to the object and return. Such measurements can be converted into lines of position (LOP’s) comprised of circles with radius equal to the distance to the object. Since marine radars use directional antennae, they can also determine an object’s bearing. However, due to its design, a radar’s bearing measurement is less accurate than its distance measurement. Understanding this concept is crucial to ensuring the optimal employment of the radar for safe navigation.
### 1301. Signal Characteristics
In most marine navigation applications, the radar signal is pulse modulated. Signals are generated by a timing circuit so that energy leaves the antenna in very short pulses. When transmitting, the antenna is connected to the transmitter but not the receiver. As soon as the pulse leaves, an electronic switch disconnects the antenna from the transmitter and connects it to the receiver. Another pulse is not transmitted until after the preceding one has had time to travel to the most distant target within range and return. Since the interval between pulses is long compared with the length of a pulse, strong signals can be provided with low average power. The duration or length of a single pulse is called pulse length, pulse duration, or pulse width. This pulse emission sequence repeats a great many times, perhaps 1,000 per second. This rate defines the pulse repetition rate (PRR). The returned pulses are displayed on an indicator screen.
### 1302. The Display
The radar display is often referred to as the plan position indicator (PPI). On a PPI, the sweep appears as a radial line, centered at the center of the scope and rotating in synchronization with the antenna. Any returned echo causes a brightening of the display screen at the bearing and range of the object. Because of a luminescent coating on the inside of the tube, the glow continues after the trace rotates past the target.
On a PPI, a target’s actual range is proportional to its distance from the center of the scope. A moveable cursor helps to measure ranges and bearings. In the “headingupward” presentation, which indicates relative bearings, the top of the scope represents the direction of the ship’s head. In this unstabilized presentation, the orientation changes as the ship changes heading. In the stabilized “north-upward” presentation, gyro north is always at the top of the scope.
The pulses of energy comprising the radar beam would form a single lobe-shaped pattern of radiation if emitted in free space. Figure 1303a shows this free space radiation pattern, including the undesirable minor lobes or side lobes associated with practical antenna design.
Although the radiated energy is concentrated into a relatively narrow main beam by the antenna, there is no clearly defined envelope of the energy radiated, although most of the energy is concentrated along the axis of the beam. With the rapid decrease in the amount of radiated energy in directions away from this axis, practical power limits may be used to define the dimensions of the radar beam.
A radar beam’s horizontal and vertical beam widths are referenced to arbitrarily selected power limits. The most common convention defines beam width as the angular width between half power points. The half power point corresponds to a drop in 3 decibels from the maximum beam strength.
The definition of the decibel shows this halving of power at a decrease in 3 dB from maximum power. A decibel is simply the logarithm of the ratio of a final power level to a reference power level:
dB = 10 log ${\displaystyle [{\frac {{\text{P}}_{1}}{{\text{P}}_{0}}}]}$
where P1 is the final power level, and P0 is a reference power level. When calculating the dB drop for a 50% reduction in power level, the equation becomes:
dB = 10 log(.5)
dB = −3dB
The radiation diagram shown in Figure 1303b depicts relative values of power in the same plane existing at the same distances from the antenna or the origin of the radar beam. Maximum power is in the direction of the axis of the beam. Power values diminish rapidly in directions away from the axis. The beam width is taken as the angle between the half-power points.
The beam width depends upon the frequency or wavelength of the transmitted energy, antenna design, and the dimensions of the antenna. For a given antenna size (antenna aperture), narrower beam widths result from using shorter wavelengths. For a given wavelength, narrower beam widths result from using larger antennas.
With radar waves being propagated in the vicinity of the surface of the sea, the main lobe of the radar beam is composed of a number of separate lobes, as opposed to the single lobe-shaped pattern of radiation as emitted in free space. This phenomenon is the result of interference between radar waves directly transmitted, and those waves which are reflected from the surface of the sea. Radar waves strike the surface of the sea, and the indirect waves reflect off the surface of the sea. See Figure 1303c. These reflected waves either constructively or destructively interfere with the direct waves depending upon the waves’ phase relationship.
Figure 1303c. Direct and indirect waves.
### 1304. Diffraction and Attenuation
Diffraction is the bending of a wave as it passes an obstruction. Because of diffraction there is some illumination of the region behind an obstruction or target by the radar beam. Diffraction effects are greater at the lower frequencies. Thus, the radar beam of a lower frequency radar tends to illuminate more of the shadow region behind an obstruction than the beam of a radar of higher frequency or shorter wavelength.
Attenuation is the scattering and absorption of the energy in the radar beam as it passes through the atmosphere. It causes a decrease in echo strength. Attenuation is greater at the higher frequencies or shorter wavelengths.
While reflected echoes are much weaker than the transmitted pulses, the characteristics of their return to the source are similar to the characteristics of propagation. The strengths of these echoes are dependent upon the amount of transmitted energy striking the targets and the size and reflecting properties of the targets.
### 1305. Refraction
If the radar waves traveled in straight lines, the distance to the radar horizon would be dependent only on the power output of the transmitter and the height of the antenna. In other words, the distance to the radar horizon would be the same as that of the geometrical horizon for the antenna height. However, atmospheric density gradients bend radar rays as they travel to and from a target. This bending is called refraction.
The distance to the radar horizon does not limit the distance from which echoes may be received from targets. Assuming that adequate power is transmitted, echoes may be received from targets beyond the radar horizon if their reflecting surfaces extend above it. The distance to the radar horizon is the distance at which the radar rays pass tangent to the surface of the Earth.
The following formula, where h is the height of the antenna in feet, gives the theoretical distance to the radar horizon in nautical miles:
${\displaystyle {\text{d}}=1.22{\sqrt {\text{h}}}}$.
### 1306. Factors Affecting Radar Interpretation
Radar’s value as a navigational aid depends on the navigator’s understanding its characteristics and limitations. Whether measuring the range to a single reflective object or trying to discern a shoreline lost amid severe clutter, knowledge of the characteristics of the individual radar used are crucial. Some of the factors to be considered in interpretation are discussed below:
• Resolution in Range. In part A of Figure 1306a, a transmitted pulse has arrived at the second of two targets of insufficient size or density to absorb or reflect all of the energy of the pulse. While the pulse has traveled from the first to the second target, the echo from the first has traveled an equal distance in the opposite direction. At B, the transmitted pulse has continued on beyond the second target, and the two echoes are returning toward the transmitter. The distance between leading edges of the two echoes is twice the distance between targets. The correct distance will be shown on the scope, which is calibrated to show half the distance traveled out and back. At C the targets are closer together and the pulse length has been increased. The two echoes merge, and on the scope they will appear as a single, large target. At D the pulse length has been decreased, and the two echoes appear separated. The ability of a radar to separate targets close together on the same bearing is called resolution in range. It is related primarily to pulse length. The minimum distance between targets that can be distinguished as separate is half the pulse length. This (half the pulse length) is the apparent depth or thickness of a target presenting a flat perpendicular surface to the radar beam. Thus, several ships close together may appear as an island. Echoes from a number of small boats, piles, breakers, or even large ships close to the shore may blend with echoes from the shore, resulting in an incorrect indication of the position and shape of the shoreline.
• Figure 1306a. Resolution in range.
• Resolution in Bearing. Echoes from two or more targets close together at the same range may merge to form a single, wider echo. The ability to separate targets close together at the same range is called resolution in bearing. Bearing resolution is a function of two variables: beam width and range to the targets. A narrower beam and a shorter distance to the objects both increase bearing resolution.
• Height of Antenna and Target. If the radar horizon is between the transmitting vessel and the target, the lower part of the target will not be visible. A large vessel may appear as a small craft, or a shoreline may appear at some distance inland.
• Reflecting Quality and Aspect of Target. Echoes from several targets of the same size may be quite different in appearance. A metal surface reflects radio waves more strongly than a wooden surface. A surface perpendicular to the beam returns a stronger echo than a non perpendicular one. A vessel seen broadside returns a stronger echo than one heading directly toward or away. Some surfaces absorb most radar energy rather that reflecting it.
• Frequency. As frequency increases, reflections occur from smaller targets.
Atmospheric noise, sea return, and precipitation complicate radar interpretation by producing clutter. Clutter is usually strongest near the vessel. Strong echoes can sometimes be detected by reducing receiver gain to eliminate weaker signals. By watching the repeater during several rotations of the antenna, the operator can often discriminate between clutter and a target even when the signal strengths from clutter and the target are equal. At each rotation, the signals from targets will remain relatively stationary on the display while those caused by clutter will appear at different locations on each sweep.
Another major problem lies in determining which features in the vicinity of the shoreline are actually represented by echoes shown on the repeater. Particularly in cases where a low lying shore is being scanned, there may be considerable uncertainty.
A related problem is that certain features on the shore will not return echoes because they are blocked from the radar beam by other physical features or obstructions. This factor in turn causes the chart-like image painted on the scope to differ from the chart of the area.
If the navigator is to be able to interpret the presentation on his radarscope, he must understand the characteristics of radar propagation, the capabilities of his radar set, the reflecting properties of different types of radar targets, and the ability to analyze his chart to determine which charted features are most likely to reflect the transmitted pulses or to be blocked. Experience gained during clear weather comparison between radar and visual images is invaluable.
Land masses are generally recognizable because of the steady brilliance of the relatively large areas painted on the PPI. Also, land should be at positions expected from the ship’s navigational position. Although land masses are readily recognizable, the primary problem is the identification of specific land features. Identification of specific features can be quite difficult because of various factors, including distortion resulting from beam width and pulse length, and uncertainty as to just which charted features are reflecting the echoes.
Sand spits and smooth, clear beaches normally do not appear on the PPI at ranges beyond 1 or 2 miles because these targets have almost no area that can reflect energy back to the radar. Ranges determined from these targets are not reliable. If waves are breaking over a sandbar, echoes may be returned from the surf. Waves may, however, break well out from the actual shoreline, so that ranging on the surf may be misleading.
Mud flats and marshes normally reflect radar pulses only a little better than a sand spit. The weak echoes received at low tide disappear at high tide. Mangroves and other thick growth may produce a strong echo. Areas that are indicated as swamps on a chart, therefore, may return either strong or weak echoes, depending on the density type, and size of the vegetation growing in the area.
When sand dunes are covered with vegetation and are well back from a low, smooth beach, the apparent shoreline determined by radar appears as the line of the dunes rather than the true shoreline. Under some conditions, sand dunes may return strong echo signals because the combination of the vertical surface of the vegetation and the horizontal beach may form a sort of corner reflector.
Lagoons and inland lakes usually appear as blank areas on a PPI because the smooth water surface returns no energy to the radar antenna. In some instances, the sandbar or reef surrounding the lagoon may not appear on the PPI because it lies too low in the water.
Coral atolls and long chains of islands may produce long lines of echoes when the radar beam is directed perpendicular to the line of the islands. This indication is especially true when the islands are closely spaced. The reason is that the spreading resulting from the width of the radar beam causes the echoes to blend into continuous lines. When the chain of islands is viewed lengthwise, or obliquely, however, each island may produce a separate return. Surf breaking on a reef around an atoll produces a ragged, variable line of echoes.
One or two rocks projecting above the surface of the water, or waves breaking over a reef, may appear on the PPI.
If the land rises in a gradual, regular manner from the shoreline, no part of the terrain produces an echo that is stronger than the echo from any other part. As a result, a general haze of echoes appears on the PPI, and it is difficult to ascertain the range to any particular part of the land.
Blotchy signals are returned from hilly ground, because the crest of each hill returns a good echo although the valley beyond is in a shadow. If high receiver gain is used, the pattern may become solid except for the very deep shadows.
Low islands ordinarily produce small echoes. When thick palm trees or other foliage grow on the island, strong echoes often are produced because the horizontal surface of the water around the island forms a sort of corner reflector with the vertical surfaces of the trees. As a result, wooded islands give good echoes and can be detected at a much greater range than barren islands.
Sizable land masses may be missing from the radar display because of certain features being blocked from the radar beam by other features. A shoreline which is continuous on the PPI display when the ship is at one position, may not be continuous when the ship is at another position and scanning the same shoreline. The radar beam may be blocked from a segment of this shoreline by an obstruction such as a promontory. An indentation in the shoreline, such as a cove or bay, appearing on the PPI when the ship is at one position, may not appear when the ship is at another position nearby. Thus, radar shadow alone can cause considerable differences between the PPI display and the chart presentation. This effect in conjunction with beam width and pulse length distortion of the PPI display can cause even greater differences.
The returns of objects close to shore may merge with the shoreline image on the PPI, because of distortion effects of horizontal beam width and pulse length. Target images on the PPI are distorted angularly by an amount equal to the effective horizontal beam width. Also, the target images always are distorted radially by an amount at least equal to one-half the pulse length (164 yards per microsecond of pulse length).
Figure 1306b illustrates the effects of ship’s position, beam width, and pulse length on the radar shoreline. Because of beam width distortion, a straight, or nearly straight, shoreline often appears crescent-shaped on the PPI. This effect is greater with the wider beam widths. Note that this distortion increases as the angle between the beam axis and the shoreline decreases.
Figure 1306b. Effects of ship’s position, beam width, and pulse length on radar shoreline.
Figure 1306c illustrates the distortion effects of radar shadow, beam width, and pulse length. View A shows the actual shape of the shoreline and the land behind it. Note the steel tower on the low sand beach and the two ships at anchor close to shore. The heavy line in view B represents the shoreline on the PPI. The dotted lines represent the actual position and shape of all targets. Note in particular:
1. The low sand beach is not detected by the radar.
2. The tower on the low beach is detected, but it looks like a ship in a cove. At closer range the land would be detected and the cove-shaped area would begin to fill in; then the tower could not be seen without reducing the receiver gain.
3. The radar shadow behind both mountains. Distortion owing to radar shadows is responsible for more confusion than any other cause. The small island does not appear because it is in the radar shadow.
4. The spreading of the land in bearing caused by beam width distortion. Look at the upper shore of the peninsula. The shoreline distortion is greater to the west because the angle between the radar beam and the shore is smaller as the beam seeks out the more westerly shore.
5. Ship No. 1 appears as a small peninsula. Its return has merged with the land because of the beam width distortion.
6. Ship No. 2 also merges with the shoreline and forms a bump. This bump is caused by pulse length and beam width distortion. Reducing receiver gain might cause the ship to separate from land, provided the ship is not too close to the shore. The Fast Time Constant (FTC) control could also be used to attempt to separate the ship from land.
Figure 1306c. Distortion effects of radar shadow, beam width, and pulse length.
### 1307. Recognition of Unwanted Echoes
Indirect or false echoes are caused by reflection of the main lobe of the radar beam off ship’s structures such as stacks and kingposts. When such reflection does occur, the echo will return from a legitimate radar contact to the antenna by the same indirect path. Consequently, the echo will appear on the PPI at the bearing of the reflecting surface. As shown in Figure 1307a, the indirect echo will appear on the PPI at the same range as the direct echo received, assuming that the additional distance by the indirect path is negligible.
Figure 1307a. Indirect echo.
Characteristics by which indirect echoes may be recognized are summarized as follows:
1. Indirect echoes will often occur in shadow sectors.
2. They are received on substantially constant bearings, although the true bearing of the radar contact may change appreciably.
3. They appear at the same ranges as the corresponding direct echoes.
4. When plotted, their movements are usually abnormal.
5. Their shapes may indicate that they are not direct echoes.
Side-lobe effects are readily recognized in that they produce a series of echoes (Figure 1307b) on each side of the main lobe echo at the same range as the latter. Semicircles, or even complete circles, may be produced. Because of the low energy of the side-lobes, these effects will normally occur only at the shorter ranges. The effects may be minimized or eliminated, through use of the gain and anti-clutter controls. Slotted wave guide antennas have largely eliminated the side-lobe problem.
Figure 1307b. Side-lobe effects.
Multiple echoes may occur when a strong echo is received from another ship at close range. A second or third or more echoes may be observed on the radarscope at double, triple, or other multiples of the actual range of the radar contact (Figure 1307c).
Figure 1307c. Multiple echoes.
Second-trace echoes (multiple-trace echoes) are echoes received from a contact at an actual range greater than the radar range setting. If an echo from a distant target is received after the following pulse has been transmitted, the echo will appear on the radarscope at the correct bearing but not at the true range. Second-trace echoes are unusual, except under abnormal atmospheric conditions, or conditions under which super-refraction is present. Secondtrace echoes may be recognized through changes in their positions on the radarscope in changing the pulse repetition rate (PRR); their hazy, streaky, or distorted shape; and the erratic movements on plotting.
As illustrated in Figure 1307d, a target return is detected on a true bearing of 090° at a distance of 7.5 miles. On changing the PRR from 2,000 to 1,800 pulses per second, the same target is detected on a bearing of 090° at a distance of 3 miles (Figure 1307e). The change in the position of the return indicates that the return is a second-trace echo. The actual distance of the target is the distance as indicated on the PPI plus half the distance the radar wave travels between pulses.
Figure 1307d. Second-trace echo on 12-mile range scale.
Figure 1307e. Position of second-trace echo on 12-mile range scale after changing PRR.
Electronic interference effects, such as may occur when near another radar operating in the same frequency band as that of the observer’s ship, is usually seen on the PPI as a large number of bright dots either scattered at random or in the form of dotted lines extending from the center to the edge of the PPI.
Interference effects are greater at the longer radar range scale settings. The interference effects can be distinguished easily from normal echoes because they do not appear in the same places on successive rotations of the antenna.
Stacks, masts, samson posts, and other structures, may cause a reduction in the intensity of the radar beam beyond these obstructions, especially if they are close to the radar antenna. If the angle at the antenna subtended by the obstruction is more than a few degrees, the reduction of the intensity of the radar beam beyond the obstruction may produce a blind sector. Less reduction in the intensity of the beam beyond the obstructions may produce shadow sectors. Within a shadow sector, small targets at close range may not be detected, while larger targets at much greater ranges will appear.
Spoking appears on the PPI as a number of spokes or radial lines. Spoking is easily distinguished from interference effects because the lines are straight on all range-scale settings, and are lines rather than a series of dots.
The spokes may appear all around the PPI, or they may be confined to a sector. If spoking is confined to a narrow sector, the effect can be distinguished from a Ramark signal of similar appearance through observation of the steady relative bearing of the spoke in a situation where the bearing of the Ramark signal should change. Spoking indicates a need for maintenance or adjustment. The PPI display may appear as normal sectors alternating with dark sectors. This is usually due to the automatic frequency control being out of adjustment. The appearance of serrated range rings indicates a need for maintenance.
After the radar set has been turned on, the display may not spread immediately to the whole of the PPI because of static electricity inside the CRT. Usually, the static electricity effect, which produces a distorted PPI display, lasts no longer than a few minutes.
Hour-glass effect appears as either a constriction or expansion of the display near the center of the PPI. The expansion effect is similar in appearance to the expanded center display. This effect, which can be caused by a nonlinear time base or the sweep not starting on the indicator at the same instant as the transmission of the pulse, is most apparent when in narrow rivers or close to shore.
The echo from an overhead power cable can be wrongly identified as the echo from a ship on a steady bearing and decreasing range. Course changes to avoid the contact are ineffective; the contact remains on a steady bearing, decreasing range. This phenomenon is particularly apparent for the power cable spanning the Straits of Messina.
Buoys are particularly poor radar targets. Weak, fluctuating echoes received from these targets are easily lost in the sea clutter. To aid in the detection of these targets, radar reflectors, designated corner reflectors, may be used. These reflectors may be mounted on the tops of buoys or designed into the structure.
Each corner reflector, shown in Figure 1308a, consists of three mutually perpendicular flat metal surfaces. A radar wave striking any of the metal surfaces or plates will be reflected back in the direction of its source. Maximum energy will be reflected back to the antenna if the axis of the radar beam makes equal angles with all the metal surfaces. Frequently, corner reflectors are assembled in clusters to maximize the reflected signal.
Figure 1308a. Corner reflectors.
Although radar reflectors are used to obtain stronger echoes from radar targets, other means are required for more positive identification of radar targets. Radar beacons are transmitters operating in the marine radar frequency band, which produce distinctive indications on the radarscopes of ships within range of these beacons. There are two general classes of these beacons: racons, which provide both bearing and range information to the target, and ramarks which provide bearing information only. However, if the ramark installation is detected as an echo on the radarscope, the range will be available also.
A racon is a radar transponder which emits a characteristic signal when triggered by a ship’s radar. The signal may be emitted on the same frequency as that of the triggering radar, in which case it is superimposed on the ship’s radar display automatically. The signal may be emitted on a separate frequency, in which case to receive the signal the ship’s radar receiver must be tuned to the beacon frequency, or a special receiver must be used. In either case, the PPI will be blank except for the beacon signal. However, the only racons in service are “in band” beacons which transmit in one of the marine radar bands, usually only the 3-centimeter band.
The racon signal appears on the PPI as a radial line originating at a point just beyond the position of the radar beacon, or as a Morse code signal (Figure 1308b) displayed radially from just beyond the beacon.
Figure 1308b. Coded racon signal.
A ramark is a radar beacon which transmits either continuously or at intervals. The latter method of transmission is used so that the PPI can be inspected without any clutter introduced by the ramark signal on the scope. The ramark signal as it appears on the PPI is a radial line from the center. The radial line may be a continuous narrow line, a broken line (Figure 1308c), a series of dots, or a series of dots and dashes.
Figure 1308c. Ramark appears as broken radial line.
### 1309. Introduction
When navigating in restricted waters, a mariner most often relies on visual piloting to provide the accuracy required to ensure ship safety. Visual piloting, however, requires clear weather; often, mariners must navigate through fog. When weather conditions render visual piloting impossible on a vessel not equipped with ECDIS, radar navigation provides a method of fixing a vessel’s position with sufficient accuracy to allow safe passage. See Chapter 8 for a detailed discussion of integrating radar into a piloting procedure.
### 1310. Fix by Radar Ranges
Since radar can more accurately determine ranges than bearings, the most accurate radar fixes result from measuring and plotting ranges to two or more objects. Measure objects directly ahead or astern first; measure objects closest to the beam last.
This procedure is the opposite to that recommended for taking visual bearings, where objects closest to the beam are measured first; however, both recommendations rest on the same principle. When measuring objects to determine a line of position, measure first those which have the greatest rate of change in the quantity being measured; measure last those which have the least rate of change. This minimizes measurement time delay errors. Since the range of those objects directly ahead or astern of the ship changes more rapidly than those objects located abeam, we measure ranges to objects ahead or astern first.
Record the ranges to the navigation aids used and lay the resulting range arcs down on the chart. Theoretically, these lines of position should intersect at a point coincident with the ship’s position at the time of the fix.
Though verifying soundings is always a good practice in all navigation scenarios, its importance increases when piloting using only radar. Assuming proper operation of the fathometer, soundings give the navigator invaluable information on the reliability of his fixes.
### 1311. Fix by Range and Bearing to One Object
Visual piloting requires bearings from at least two objects; radar, with its ability to determine both bearing and range from one object, allows the navigator to obtain a fix where only a single navigation aid is available. An example of using radar in this fashion occurs in approaching a harbor whose entrance is marked with a single, prominent object such as Chesapeake Light at the entrance of the Chesapeake Bay. Well beyond the range of any land-based visual navigation aid, and beyond the visual range of the light itself, a shipboard radar can detect the light and provide bearings and ranges for the ship’s piloting party. Care must be taken that fixes are not taken on any nearby stationary vessel.
This methodology is limited by the inherent inaccuracy associated with radar bearings; typically, a radar bearing is accurate to within about 5° of the true bearing. Therefore, the navigator must carefully evaluate the resulting position, possibly checking it with a sounding. If a visual bearing is available from the object, use that bearing instead of the radar bearing when laying down the fix. This illustrates the basic concept discussed above: radar ranges are inherently more accurate than radar bearings. One must also be aware that if the radar is gyro stabilized and there is a gyro error of more than a degree or so, radar bearings will be in error by that amount.
Prior to using this method, the navigator must ensure that he has correctly identified the object from which the bearing and range are to be taken. Using only one navigation aid for both lines of position can lead to disaster if the navigation aid is not properly identified.
### 1312. Fix Using Tangent Bearings and Range
This method combines bearings tangent to an object with a range measurement from some point on that object. The object must be large enough to provide sufficient bearing spread between the tangent bearings; often an island or peninsula works well. Identify some prominent feature of the object that is displayed on both the chart and the radar display. Take a range measurement from that feature and plot it on the chart. Then determine the tangent bearings to the feature and plot them on the chart.
Steep-sided features work the best. Tangents to low, sloping shorelines will seriously reduce accuracy, as will tangent bearings in areas of excessively high tides, which can change the location of the apparent shoreline by many meters.
### 1313. Fix by Radar Bearings
The inherent inaccuracy of radar bearings discussed above makes this method less accurate than fixing position by radar range. Use this method to plot a position quickly on the chart when approaching restricted waters to obtain an approximate ship’s position for evaluating radar targets to use for range measurements. Unless no more accurate method is available, this method is not suitable while piloting in restricted waters.
### 1314. Fischer Plotting
In Fischer plotting, the navigator adjusts the scale of the radar to match the scale of the chart in use. Then he places a clear plastic disk, sized to the radar, on the center of the radar screen and quickly traces the shape of land and location of any navigation aids onto the plastic overlay with a grease pencil. Taking the plastic with the tracings on it to the chart, he matches the features traced from the radar with the chart’s features. A hole in the center of the plastic allows the navigator to mark the position of the ship at the time the tracing was done. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 2, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.640215277671814, "perplexity": 1314.88017863779}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347426956.82/warc/CC-MAIN-20200602224517-20200603014517-00009.warc.gz"} |
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http://watershade.net/wmcclain/context-help.html | # ConTeXt and pdfTeX Beginners Help Page
Best Viewed With Any Browser
Last updated: July 28, 2003
## Introduction
I am a beginner at TeX myself, and wanted to use this page to record those little hints and examples which helped me over the rough spots, in the hope that they may help others. I'll refine and extend the examples as I gain more experience.
The techniques I describe here are used to produce all of the Sattre Press titles.
I presume the reader has all the documents available from the ConTeXt and pdfTeX web pages. Other sources of information: both packages have email support lists which are archived on the web. Searching the usenet group comp.text.tex can be useful also.
Here is an easy way to fetch a copy of all the ConTeXt online documents. Fetch this file:
http://www.pragma-ade.com/context.www
You may want to edit it to remove lines refering to languages and documents you know you don't want. Then, this will fetch copies of the documents into the current directory:
wget -Nxi context.www
I use SuSE Linux and TeXLive. However, it seems that TeX knowledge is rather portable across systems, and it should be possible to adapt the examples to other platforms.
• ConTeXt
• pdfTeX
• TUG and TeXLive
## File Locations
Everything in the TeX world has its place. There is a vast amount of material in the TeX directory tree, which on my system starts at /usr/TeX/.
Further, you can customize local and auxiliary directory structures. Look at texmf.cnf.
Experiment with the kpsewhich utility, particularly with the --show-path option, which shows all the different places in which TeX will look for different files.
Using this, I see that the current directory is always first in the path, meaning I can make all sorts of "system" changes which effect only the current project. As far as I can tell, all files of interest are treated this way: .cfg, .cnf, .tex, .map, .tfm, .pfb, etc.
Once a new file becomes stable it can be promoted to later ("higher") directories in the search path. kpsewhich shows that I have a personal TeX directory tree in my home directory: /home/wmcclain/texmf. Then there are site-specific directories, etc.
Remember: if you add or delete any files in the TeX tree (see the list of directories $TEXMFDBS in texmf.cnf), you must rebuild the filename database with mktexlsr. On my system, texhash is a synonym for this command. On Linux, I run updatedb daily, and use locate to find all those pesky configuration files. ## Installation Originally I used the TeX distribution that came with SuSE Linux, but have since switched to the TeXLive distribution. My original installation notes for SuSE are available here. ### TeXLive TeXLive CDs are available to TUG members and can also been downloaded (by anyone) as ISO images from the TUG site shown above. I follow the instructions given on the disk, using the default directory structure which has /usr/TeX/ as the top level: su root export CDPATH= # this causes problems if set mount /cdrom cd /cdrom sh install-cd.sh (select packages and languages) (run "Install") export PATH=$PATH:/usr/TeX/bin/i386-linux
export TEXMFCNF=/usr/TeX/texmf/web2c/
texhash
exit # from su
Then I edit the .bashrc in my home directory and add these lines:
export PATH=$PATH:/usr/TeX/bin/i386-linux export TEXMFCNF=/usr/TeX/texmf/web2c/ export MANPATH=$MANPATH:/usr/TeX/man
export INFOPATH=$INFOPATH:/usr/TeX/info The last two lines are omitted from the TeXLive instructions. ### ConTeXt ConTeXt is under rapid development and we need to install updated versions from time to time. The zipped archives are available from the Pragma site listed above. Here is how I install new versions: su root mv cont-tmf.zip /usr/TeX/texmf cd /usr/TeX/texmf rm tex/context/base/* # safer to clean out old files first rm metapost/context/base/* # ...also remove metafun files rm metapost/context/*.mp # ...and any from an obsolete version unzip -a -L -o cont-tmf.zip # overwrites existing files # Edit texexec.ini afterwards? cp context/config/texexec.rme context/config/texexec.ini # Edit cont-sys.tex afterwards? Specifically: uncomment the line: # # \autoloadmapfilestrue # # For Metapost use, make sure these lines are uncommented: # # \runMPgraphicstrue # \runMPTEXgraphicstrue # \useMETAFUNformattrue cp tex/context/user/cont-sys.rme tex/context/user/cont-sys.tex # # Edit /usr/TeX/texmf/web2c/texmf.cnf and ensure that "shell_escape = t". This # is what TeX people somewhat obscurely call "write18 enabled". # export PATH=$PATH:/usr/TeX/bin/i386-linux # root doesn't have this on my system
texhash
texexec --make en # en = english
texexec --make --alone metafun
mv metafun.mem /usr/TeX/texmf-var/web2c/metafun.mem
texhash
exit # from "su root"
## Using TeXLive fonts
TeXLive comes with a number of Type1 fonts. This section shows how to reference them from ConTeXt.
### Predefined fonts
Font Declaration Notes
"Bluesky" Computer Modern This is the default when no font declarations are used.
"CM-Super" Computer Modern \usetypescript[modern][ec] \setupbodyfont[modern]
Palatino \usetypescript[berry][ec] % or [8r] \usetypescript[palatino][ec] % \setupbodyfont[palatino] This is actually URW Palladio, a copy of Hermann Zapf's Palatino.
Times, Helvetica and Courier \usetypescript[berry][ec] % or [8r] \setupbodyfont[pos] These are all from the URW Nimbus package. Times is the default serif face, \ss produces Helvetica, and \tt produces Courier.
Bookman \usetypescript[berry][ec] % or [8r] \definetypeface[bookman][rm][serif][bookman][default][encoding=ec] \setupbodyfont[bookman] URW Bookman
Charter \usetypescript[berry][ec] % or [8r] \definetypeface[charter][rm][serif][charter][default][encoding=ec] \setupbodyfont[charter] Bitstream Charter
Utopia \usetypescript[berry][ec] \definetypeface[utopia][rm][serif][utopia][default][encoding=ec] \setupbodyfont[utopia] Because of a bug in TeXLive 7, the tfm and vf files for Adobe Utopia are not installed correctly. To fix this:
cd ~/texmf wget http://www.gutenberg.eu.org/pub/gut/distribs/texlive/7/utopia.tar.gz tar zxvf utopia.tar.gz texhash
## Selecting Fonts
Fonts are a complicated business, but become easier to deal with once you have run a few experiments. The primary document is Fonts in ConTeXt (mfonts.pdf).
Note that we tend to be spoiled by the default Computer Modern font which has a large number of good features which just work automatically. Emulating that capability with a new font requires a good deal of setup.
### Simple (and not very useful) method
You can simply specify a font file and use it, either in plain TeX or by using ConTeXt macros. This is not very useful because it does not give you the convenient switching to italic, bold, small caps, math mode, etc, which a well-defined typeface will do. However, it is instructive to try it, just to prove that the system is setup correctly and that the maps and font files can be found.
You can (for a start) use any font listed in pdftex.map, presuming both the .tfm and .pfb font files exist. (This is not always the case on my system).
For example, here is the first data line in my pdftex.map file:
bchb8r CharterBT-Bold "TeXBase1Encoding ReEncodeFont" <8r.enc <bchb8a.pfb
The contents of pdftex.map are documented in The pdfTeX User Manual (pdftexman.pdf). For now, just note that this line refers to "Bitstream Charter Bold." The first field, bchb8r, is the name of a .tfm (TeX Font Metric) file, and bchb8a.pfb is a Type1 font file. In TeX programs, fonts are identified by their .tfm names.
Since both bchb8r.tfm and bchb8a.pfb exist on my system, I can use the font as follows.
Using just plain TeX:
\font\myfirstfont=bchb8r
\myfirstfont Of wind I sang, a wind there came, and in the branches blew.
Using ConTeXt macros:
\definefontsynonym[CharterBT-Bold][bchb8r][encoding=8r]
\definefont[MySecondFont][CharterBT-Bold]
\starttext
\MySecondFont I sang of leaves, of leaves of gold, and leaves of gold there grew.
\stoptext
### Using Typescripts
ConTeXt now uses typescripts to define and select fonts. This is the way to go for maximum flexibility.
"Typescripts are in fact just organized definitions" says mfonts.pdf. They are a way of building a database of names which provides layers of abstraction. The TeX document can be written so that it will continue to be "correct" even as major changes in fonts, families and styles are made at the deeper levels.
#### typescript files
Typescripts are definitions contained between \starttypescript and \stoptypescript. The typescripts are found in and loaded from several file sources:
• Several type-*.tex files are automatically searched. See the list in mfonts.pdf.
• A file type-loc.tex in the search path will be searched automatically.
• Any file in the search path, for example, myscripts.tex, can be loaded with \usetypescriptfile[myscripts].
#### A simple example
For example, using Bitstream Charter again, I have these fonts on my system:
bchr8r roman bchb8r bold bchri8r italic bchbi8r bold italic
I can create this typescript file, type-charter.tex:
\usetypescriptfile[type-buy]
\starttypescript [serif] [charter] [8r]
\definefontsynonym [Charter-Roman] [bchr8r] [encoding=8r]
\definefontsynonym [Charter-Bold] [bchb8r] [encoding=8r]
\definefontsynonym [Charter-Italic] [bchri8r] [encoding=8r]
\definefontsynonym [Charter-Bold-Italic] [bchbi8r] [encoding=8r]
\stoptypescript
\starttypescript [serif] [charter] [name]
\usetypescript[serif][fallback]
\definefontsynonym [Serif] [Charter-Roman]
\definefontsynonym [SerifBold] [Charter-Bold]
\definefontsynonym [SerifItalic] [Charter-Italic]
\definefontsynonym [SerifBoldItalic] [Charter-Bold-Italic]
\stoptypescript
\starttypescript [Charter]
\definetypeface [MyCharter] [rm] [serif] [charter] [default] [encoding=8r]
\stoptypescript
And use it like this:
\usetypescriptfile[type-charter]
\usetypescript[Charter]
\setupbodyfont[MyCharter]
\starttext
This is roman, {\bf bold}, {\it italic}, {\bi bold-italic},
{\tfa bigger} and {\tfx smaller}.
\stoptext
#### Multiple fonts
I also have Adobe Utopia, so I can make a type-utopia.tex typescript file very similar to the Charter example above:
\usetypescriptfile[type-buy]
\starttypescript [serif] [utopia] [8r]
\usetypescript[serif][fallback]
\definefontsynonym [Utopia-Roman] [putr8r] [encoding=8r]
\definefontsynonym [Utopia-Bold] [putb8r] [encoding=8r]
\definefontsynonym [Utopia-Italic] [putri8r] [encoding=8r]
\definefontsynonym [Utopia-Bold-Italic] [putbi8r] [encoding=8r]
\stoptypescript
\starttypescript [serif] [utopia] [name]
\definefontsynonym [Serif] [Utopia-Roman]
\definefontsynonym [SerifBold] [Utopia-Bold]
\definefontsynonym [SerifItalic] [Utopia-Italic]
\definefontsynonym [SerifBoldItalic] [Utopia-Bold-Italic]
\stoptypescript
\starttypescript [Utopia]
\definetypeface [MyUtopia] [rm] [serif] [utopia] [default] [encoding=8r]
\stoptypescript
And then use both fonts in the same job:
\usetypescriptfile[type-charter]
\usetypescript[Charter]
\usetypescriptfile[type-utopia]
\usetypescript[Utopia]
\setupbodyfont[MyCharter]
\starttext
This is Charter roman, {\bf bold}, {\it italic}, {\bi bold-italic},
{\tfa bigger} and {\tfx smaller}.
\switchtobodyfont[MyUtopia]
This is Utopia roman, {\bf bold}, {\it italic}, {\bi bold-italic},
{\tfa bigger} and {\tfx smaller}.
\stoptext
Note that the default Computer Modern font is always available, even when the job defines other fonts: declare it with \usetypescript[modern][default] and select it with \switchtobodyfont[modern].
#### Questions
What does the \usetypescriptfile[type-buy] do? It loads a typescript which contains the definition of the [serif][fallback] typescript which I use later.
What does the \usetypescript[serif][fallback] do? It simplifies the definition of my new typescript. My example fonts are very simple and do not have slanted or smallcaps variants. ConTeXt requires those variants to be defined. I could add dummy declarations and define SerifSlanted to be the same as SerifItalic, SerifBoldSlanted to be SerifBoldItalic, and SerifCaps to be simply Serif. However, if you look at the definition of the [serif][fallback] typescript in type-buy.tex, you will see that those declarations have already been made. My typescript can "inherit" from the predefined fallback typescript.
What about the encoding=8r references? I specified these because that was what was listed for these fonts in pdftex.map. I'll try to add more on encodings to this document someday.
What are the parameters to \starttypescript? Typescripts can have up to three "specifiers". It is like having a database where you can use up to three keys to find a record. You can make up your own values. For example, if I have:
\starttypescript[A][B][C]
% ...various statements
\stoptypescript
I can find and execute the typescript with:
\usetypescript[A][B][C]
The keyword all matches any value:
\usetypescript[A][B][all]
These examples will not match typescript [A][B][C]:
\usetypescript[A]
\usetypescript[A][B]
\usetypescript[A][B][D]
You can have lists of key values to match. If I have:
\starttypescript[A][B][C]
% ...various statements
\stoptypescript
\starttypescript[A][B][Z]
% ...various statements
\stoptypescript
Then I can execute both typescripts with:
\usetypescript[A][B][C,Z]
Note that the search for typescript matches has a cumulative effect. Our database allows duplicate key values and the search will find and execute all the matches.
What are the parameters to \definetypeface? This is where it all comes together. Suppose we have:
\definetypeface[A][B][C][D][E][F]
This means:
• Define typeface A (any name you like) in its variant B, where the common variants are:
• rm: roman (normal)
• ss: sans serif
• tt: monospaced
• mm: math mode
• cg: calligraphy
• Use typescript [C][D][name] to define the styles for this variant. C can be any name you like, but by convention is commonly one or more of:
• serif
• sans
• mono
• math
• handwriting
D can be any name you like. Usually it is some variation on the font name.
• Use typescript [C][E][size] to define the size information for this typeface.
• Use F for other options, typically encoding and rscale.
Example. Now we can interpret the setup of the font Charter as given above:
\starttypescript [serif] [charter] [name]
\usetypescript[serif][fallback]
\definefontsynonym [Serif] [Charter-Roman]
\definefontsynonym [SerifBold] [Charter-Bold]
\definefontsynonym [SerifItalic] [Charter-Italic]
\definefontsynonym [SerifBoldItalic] [Charter-Bold-Italic]
\stoptypescript
\starttypescript [Charter]
\definetypeface [MyCharter] [rm] [serif] [charter] [default] [encoding=8r]
\stoptypescript
This means:
• Create a typescript Charter which packages all the following.
• Define a font "MyCharter" in its normal (roman) variant.
• Use typescript [serif][charter][name] to define its styles.
• Use typescript [serif][fallback] for any styles we haven't defined.
• Use typescript [serif][default] for the size information. (Found in type-siz.tex).
• Use encoding 8r.
What are the predefined style names? The style names used in the \definefontsynonym are special in that ConTeXt uses them to implement the font switching macros such as \bf, \it, \sc, etc. The predefined names are:
• [Serif,Sans,Mono]
• [Serif,Sans,Mono]Bold
• [Serif,Sans,Mono]Italic
• [Serif,Sans,Mono]BoldItalic
• [Serif,Sans,Mono]Slanted
• [Serif,Sans,Mono]BoldSlanted
• [Serif,Sans,Mono]Caps
We also have these styles:
• MathAlpha
• MathAlphaBold
• MathBeta
• MathExtension
• MathExtensionBold
• MathGamma
• MathItalic
• MathItalicBold
• MathRoman
• MathRomanBold
• MathSymbol
• MathSymbolBold
• OldStyle
## Installing New Fonts
### Type1
#### Using texfont
The texfont utility is part of the ConTeXt package. It can be used instead of fontinst to install new fonts. The manual is Texfont Explained (mtexfont.pdf).
I purchased Adobe Sabon from Eyewire (now defunct) because the Adobe site was not happy with my browser that day. (And now I see that Adobe requires a custom download manager. Forget that). The typeface was in two packages: "Sabon" and "Sabon SC+OSF". I chose the Windows Type1 variants and downloaded these two files:
17100088.exe
17100197.exe
I had been told that these .exe files were actually zip archives. Not true. They were MS Windows executables. I had to take them to an MS machine to unpack them.
The Sabon files:
Install instructions.txt
sab_____.afm
sabi____.afm
sabi____.inf
sab_____.inf
sabi____.pfb
sabi____.pfm
sab_____.pfb
sab_____.pfm
sai_____.afm
sai_____.inf
sai_____.pfb
sai_____.pfm
sar_____.afm
sar_____.inf
sar_____.pfb
sar_____.pfm
The Sabon SC+OSF files:
Install instructions.txt
sabio___.afm
sabio___.inf
sabio___.pfb
sabio___.pfm
sabof___.afm
sabof___.inf
sabof___.pfb
sabof___.pfm
saiof___.afm
saiof___.inf
saiof___.pfb
saiof___.pfm
sarsc___.afm
sarsc___.inf
sarsc___.pfb
sarsc___.pfm
Only the .afm and .pfb files are needed for TeX.
I put the originals in a safe place and copied all the files into a temporary directory: /tmp/fonts. I decided to use the TeX root under my home directory for installing new fonts: /home/wmcclain/texmf.
Then, installing the font is a simple matter of:
texfont --fontroot=/home/wmcclain/texmf --sourcepath=/tmp/fonts --vendor=adobe --collection=sabon --makepath --install
I find these new paths and files created:
Under /home/wmcclain/texmf/fonts/tfm/adobe/sabon:
texnansi-raw-sabio.tfm
texnansi-raw-sabi.tfm
texnansi-raw-sabof.tfm
texnansi-raw-sab.tfm
texnansi-raw-saiof.tfm
texnansi-raw-sai.tfm
texnansi-raw-sarsc.tfm
texnansi-raw-sar.tfm
texnansi-sabio.tfm
texnansi-sabi.tfm
texnansi-sabof.tfm
texnansi-sab.tfm
texnansi-saiof.tfm
texnansi-sai.tfm
texnansi-sarsc.tfm
texnansi-sar.tfm
Under /home/wmcclain/texmf/fonts/type1/adobe/sabon:
sabio___.pfb
sabi____.pfb
sabof___.pfb
sab_____.pfb
saiof___.pfb
sai_____.pfb
sar_____.pfb
sarsc___.pfb
Under /home/wmcclain/texmf/fonts/vf/adobe/sabon:
texnansi-sabio.vf
texnansi-sabi.vf
texnansi-sabof.vf
texnansi-sab.vf
texnansi-saiof.vf
texnansi-sai.vf
texnansi-sarsc.vf
texnansi-sar.vf
And finally, this file:
/home/wmcclain/texmf/pdftex/config/texnansi-adobe-sabon.map
which contains the lines:
% This file is generated by the TeXFont Perl script.
%
% You need to add the following line to pdftex.cfg:
%
%
% Alternatively in your TeX source you can say:
%
%
% In ConTeXt you can best use:
%
texnansi-raw-sab Sabon-Bold 4 < sab_____.pfb texnansi.enc
texnansi-raw-sabi Sabon-BoldItalic 4 < sabi____.pfb texnansi.enc
texnansi-raw-sabio Sabon-BoldItalicOsF 4 < sabio___.pfb texnansi.enc
texnansi-raw-sabof Sabon-BoldOsF 4 < sabof___.pfb texnansi.enc
texnansi-raw-sai Sabon-Italic 4 < sai_____.pfb texnansi.enc
texnansi-raw-saiof Sabon-ItalicOsF 4 < saiof___.pfb texnansi.enc
texnansi-raw-sar Sabon-Roman 4 < sar_____.pfb texnansi.enc
texnansi-raw-sarsc Sabon-RomanSC 4 < sarsc___.pfb texnansi.enc
That's the complete installation. We still have to define the typeface to ConTeXt, using the techniques shown above in "Selecting Fonts - Using Typescripts".
I create a file type-sabon.tex in the TeX path, which contains:
%
%
\starttypescript [serif] [sabon] [texnansi]
\definefontsynonym [Sabon-Roman] [texnansi-sar] [encoding=texnansi]
\definefontsynonym [Sabon-Bold] [texnansi-sab] [encoding=texnansi]
\definefontsynonym [Sabon-Italic] [texnansi-sai] [encoding=texnansi]
\definefontsynonym [Sabon-Bold-Italic] [texnansi-sabi] [encoding=texnansi]
\definefontsynonym [Sabon-Roman-SmallCaps][texnansi-sarsc] [encoding=texnansi]
\definefontsynonym [Sabon-Italic-OSF] [texnansi-saiof] [encoding=texnansi]
\definefontsynonym [Sabon-Bold-OSF] [texnansi-sabof] [encoding=texnansi]
\definefontsynonym [Sabon-Bold-Italic-OSF][texnansi-sabio] [encoding=texnansi]
\stoptypescript
\starttypescript [serif] [sabon] [name]
\usetypescript[serif][fallback]
\definefontsynonym [Serif] [Sabon-Roman]
\definefontsynonym [SerifBold] [Sabon-Bold]
\definefontsynonym [SerifItalic] [Sabon-Italic]
\definefontsynonym [SerifBoldItalic] [Sabon-Bold-Italic]
\definefontsynonym [SerifCaps] [Sabon-Roman-SmallCaps]
% the regular old-style figures are in the small-caps file
\definefontsynonym [OldStyle] [Sabon-Roman-SmallCaps]
\stoptypescript
\starttypescript [Sabon]
\definetypeface [Sabon] [rm] [serif] [sabon] [default] [encoding=texnansi]
\stoptypescript
Important: the \loadmapfile macro will not work unless the \autoloadmapfilestrue line is uncommented in cont-sys.tex.
Important: note that we do not reference the texnansi-raw-* files in the font declaration. I made that mistake in the first version. That usage works for many characters, but not for ligatures and some other things. The right way to do it is to reference the virtual font files, as shown.
Using the font is easy:
\usetypescriptfile[type-sabon]
\usetypescript[Sabon]
\setupbodyfont[Sabon]
\starttext
This is Sabon roman, {\it italic,} {\bf bold,} and {\bi bold-italic.}
{\em \bf This is also bold-italic.}
We have {\sc small caps} and old-style figures: {\os 0123456789}.
\stoptext
The font files defined in the typescript give us a palette for assembling new typefaces. For example, I bought eight font files, but three are not being used, the ones that have bold and italic old-style figures:
[Sabon-Italic-OSF] [texnansi-saiof]
[Sabon-Bold-OSF] [texnansi-sabof]
[Sabon-Bold-Italic-OSF][texnansi-sabio]
Indeed, ConTeXt does not provide a way of combining both old-style and bold or italic; this does not do what you think it might:
{\em \os 0123456789}
The figures will be old-style regular, not italic. The way to use these fonts is to define a new typeface that always uses old-style figures in the bold and italic forms. We add some lines to type-sabon.tex which now looks like:
%
%
\starttypescript [serif] [sabon, sabon-oldstyle] [texnansi]
\definefontsynonym [Sabon-Roman] [texnansi-sar] [encoding=texnansi]
\definefontsynonym [Sabon-Bold] [texnansi-sab] [encoding=texnansi]
\definefontsynonym [Sabon-Italic] [texnansi-sai] [encoding=texnansi]
\definefontsynonym [Sabon-Bold-Italic] [texnansi-sabi] [encoding=texnansi]
\definefontsynonym [Sabon-Roman-SmallCaps][texnansi-sarsc] [encoding=texnansi]
\definefontsynonym [Sabon-Italic-OSF] [texnansi-saiof] [encoding=texnansi]
\definefontsynonym [Sabon-Bold-OSF] [texnansi-sabof] [encoding=texnansi]
\definefontsynonym [Sabon-Bold-Italic-OSF][texnansi-sabio] [encoding=texnansi]
\stoptypescript
\starttypescript [serif] [sabon] [name]
\usetypescript[serif][fallback]
\definefontsynonym [Serif] [Sabon-Roman]
\definefontsynonym [SerifBold] [Sabon-Bold]
\definefontsynonym [SerifItalic] [Sabon-Italic]
\definefontsynonym [SerifBoldItalic] [Sabon-Bold-Italic]
\definefontsynonym [SerifCaps] [Sabon-Roman-SmallCaps]
% the regular old-style figures are in the small-caps file
\definefontsynonym [OldStyle] [Sabon-Roman-SmallCaps]
\stoptypescript
\starttypescript [Sabon]
\definetypeface [Sabon] [rm] [serif] [sabon] [default] [encoding=texnansi]
\stoptypescript
\starttypescript [serif] [sabon-oldstyle] [name]
\usetypescript[serif][fallback]
\definefontsynonym [Serif] [Sabon-Roman]
\definefontsynonym [SerifBold] [Sabon-Bold-OSF]
\definefontsynonym [SerifItalic] [Sabon-Italic-OSF]
\definefontsynonym [SerifBoldItalic] [Sabon-Bold-Italic-OSF]
\definefontsynonym [SerifCaps] [Sabon-Roman-SmallCaps]
% the regular old-style figures are in the small-caps file
\definefontsynonym [OldStyle] [Sabon-Roman-SmallCaps]
\stoptypescript
\starttypescript [SabonOldStyle]
\definetypeface [SabonOldStyle] [rm] [serif] [sabon-oldstyle] [default] [encoding=texnansi]
\stoptypescript
Then we can see our old-style figures:
\usetypescriptfile[type-sabon]
\usetypescript[SabonOldStyle]
\setupbodyfont[SabonOldStyle]
\starttext
This is Sabon roman 0123456789,
old-style \os 0123456789,
{\it italic 0123456789,}
{\bf bold 0123456789,}
and {\bi bold-italic 0123456789.}
{\em \bf This is also bold-italic 0123456789.}
\stoptext
Note that the usage is a bit inconsistent: bold and italic use old-style figures by default and do not require \os, but the regular font uses the standard "lining" figures and does require \os for the old-style figures. It would be more consistent to make old-style the default for the regular font, but we would need to make a virtual font to do that. (Reason: the regular old-style figures are contained in the small-caps font file. Virtual fonts allow us to assemble portions of existing font files into a new "view").
Using the scheme shown here, if we want both lining and old-style figures in bold or italic, we have to use both typefaces and switch between them as necessary.
This example does not provide any math mode definitions.
### TrueType
Truetype fonts are supported by pdfTeX. No special setup is required for ConTeXt. The font definitions within ConTeXt are identical for all font formats, since TeX needs only a reference to a tfm file describing the font metrics.
In the TeXLive support directory is a utility ttf2tex which automates the installation of Truetype font files. I haven't used it because it is limited to 8-character file names.
Here is the manual method I've used; this could be worked into an installation script.
As an example, I'll use the Bergamo (Bembo) Roman font from the FontSite collection (even though a Type1 version is also provided). The encoding is up to you; I always use texnansi.enc by default. I use a naming convention similar to that used by texfont.
My habit is to rename font files so that the extensions at least are in lower case. This would also be good time to eliminate spaces and other "strange" characters in the file names:
mv BERGAMO_.TTF bergamo_.ttf
Generate a tfm file for the Truetype font file, and a "virtual property list" file. Note that I specify the complete path of the encoding file because ttf2tfm does not seem to find it automatically:
ttf2tfm bergamo_.ttf -T /usr/TeX/texmf/dvips/ly1/texnansi.enc -v texnansi-bergamo.vpl texnansi-raw-bergamo.tfm
Create the vf virtual font file and a tfm to go with it:
vptovf texnansi-bergamo.vpl texnansi-bergamo.vf texnansi-bergamo.tfm
You may wonder why we need this virtual font file. We could use the "raw" tfm directly, but we lose ligature and kerning information if we do. The virtual font definition fixes that.
Move the files into their proper places. I use the texmf directory tree under my home directory:
mkdir -p ~/texmf/fonts/truetype/fontsite/bergamo
mkdir -p ~/texmf/fonts/tfm/fontsite/bergamo
mkdir -p ~/texmf/fonts/vf/fontsite/bergamo
mv bergamo_.ttf ~/texmf/fonts/truetype/fontsite/bergamo
mv texnansi-raw-bergamo.tfm ~/texmf/fonts/tfm/fontsite/bergamo
mv texnansi-bergamo.tfm ~/texmf/fonts/tfm/fontsite/bergamo
mv texnansi-bergamo.vf ~/texmf/fonts/vf/fontsite/bergamo
Finally we need a map file entry which connects the tfm file to the ttf file. We could add this to the global pdftex.map file, but I prefer to make a separate map file for each typeface set. Create the file ~/texmf/pdftex/config/texnansi-bergamo.map and add this line:
texnansi-raw-bergamo <bergamo_.ttf texnansi.enc
Refresh the filename database:
texhash
Then this simple test should use the font:
\pdfmapfile{+texnansi-bergamo.map}
\font\Myfont=texnansi-bergamo
\Myfont This is a test.
\bye
Or, you can display all the glyphs in the font with this ConTeXt program:
\usemodule[fnt-01]
\starttext
\ShowFont[Bergamo][texnansi-bergamo][texnansi]
\stoptext
If you have multiple font files in the typeface (bold, italic, small caps, etc) then each must be processed by the steps shown above. Any number of mapping lines can be placed in one map file. Creating a typescript definition for ConTeXt is described elsewhere on this page; the process is the same regardless of the font file format.
How do the tfm, vf and map files work together? It goes something like this:
• The TeX document references texnansi-bergamo. This is the metric file texnansi-bergamo.tfm.
• By magic, TeX sees that this metric file is matched with a virtual font file: texnansi-bergamo.vf.
• This virtual font file gets its metric information from another file: texnansi-raw-bergamo.tfm. You can verify this by looking at the FONTNAME field in the .vpl file, or by running vftovp texnansi-bergamo.vf and searching the result for the same field.
• Finally, when pdfTeX needs to access the shape information for the glyphs, it searches texnansi-bergamo.map for texnansi-raw-bergamo (the tfm name) in the first field, and uses bergamo_.ttf for the glyph shapes, and texnansi.enc for the encoding.
### Metafont
The pdftex documents recommend against using bitmapped fonts because Adobe Acrobat does not render them very well. They are also not resolution-independent and have to be generated for every font variety and size used.
Nevertheless they are supported. I don't know much about using Metafont, but here is an example using the Duerer font available on both CTAN and TeXLive.
The collection consists of a series of .mf and .tfm files. The .mf files go in:
fonts/source/public/duerer
and the .tfm files belong in:
fonts/tfm/public/duerer
I note that TeXLive comes with the .tfm files, but that they are not included on CTAN, and that the CTAN Metafont directories often do not have .tfm files. They can be generated from the .mf files with Metafont, but I don't give an example here because I haven't had to do it yet. Consult the Metafont documentation.
We can now run a quick test with a script like this (note that Duerer contains only the 26 uppercase letters):
\font\Bold=cdb10
\font\Informal=cdi10
\font\Roman=cdr10
\font\Slanted=cdsl10
\font\Sans=cdss10
\font\Typewriter=cdtt10
\starttext
\Roman THIS IS COMPUTER DUERER ROMAN
\Bold BOLD
\Slanted SLANTED
\Informal INFORMAL
\Sans SANS SERIF
\Typewriter AND TYPEWRITER
\stoptext
Note that we cannot yet get PDF output from pdftex with this. If we try, using texexec --pdf example.tex, we get messages like:
Warning: pdfetex (file cdtt10): Font cdtt10 at 600 not found
The .pk bitmap files have not yet been created and pdftex doesn't do it automatically. The files can be created with Metafont utilities, but I've found it easiest just to make a .dvi version of the document and let xdvi create the files automatically:
texexec example.tex
xdvi example.dvi
We see a series of messages like so:
kpathsea: Running mktexpk --mfmode ljfour --bdpi 600 --mag 1+0/600 --dpi 600 cdtt10
mktexpk: Running mf \mode:=ljfour; mag:=1+0/600; nonstopmode; input cdtt10
On my system the .pk files are created in texmf-var/fonts/pk/ljfour/public/duerer. The xdvi window should show the test document with the Duerer fonts.
Now we can get a PDF version using texexec --pdf example.tex. Don't zoom in too much!
Here is a typescript for Duerer, using the techniques described elsewhere on this page. I don't specify any encodings because I'm not sure of how encodings work with Metafont files:
% Typescript for the Duerer metafont typeface.
%
% The Informal'' is a serifed variation; I assign it to
% italic so that we can access both it and slanted in the same
% setup.
%
\starttypescript [serif] [duerer]
\definefontsynonym [Duerer-Roman] [cdr10]
\definefontsynonym [Duerer-Bold] [cdb10]
\definefontsynonym [Duerer-Slanted] [cdsl10]
\definefontsynonym [Duerer-Informal] [cdi10]
\stoptypescript
\starttypescript [sans] [duerer]
\definefontsynonym [Duerer-Sans] [cdss10]
\stoptypescript
\starttypescript [mono] [duerer]
\definefontsynonym [Duerer-Mono] [cdtt10]
\stoptypescript
\starttypescript [serif] [duerer] [name]
\definefontsynonym [Serif] [Duerer-Roman]
\definefontsynonym [SerifBold] [Duerer-Bold]
\definefontsynonym [SerifSlanted] [Duerer-Slanted]
\definefontsynonym [SerifItalic] [Duerer-Informal]
\stoptypescript
\starttypescript [sans] [duerer] [name]
\definefontsynonym [Sans] [Duerer-Sans]
\stoptypescript
\starttypescript [mono] [duerer] [name]
\definefontsynonym [Mono] [Duerer-Mono]
\stoptypescript
\starttypescript [Duerer]
\definetypeface [Duerer] [rm] [serif] [duerer] [default]
\definetypeface [Duerer] [ss] [sans] [duerer] [default]
\definetypeface [Duerer] [tt] [mono] [duerer] [default]
\stoptypescript
Name this type-duerer.tex and place in the tex directory tree where .tex files are found. On my system I put typescripts in ~/texmf/tex/generic.
Run texhash.
And here is a test document similar to the one above:
\usetypescriptfile[type-duerer]
\usetypescript[Duerer]
\setupbodyfont[Duerer]
\starttext
THIS IS COMPUTER DUERER ROMAN
{\bf BOLD}
{\sl SLANTED}
{\it INFORMAL}
{\ss SANS SERIF}
{\tt AND TYPEWRITER}
\stoptext
Important: before we can produce a PDF version we must again do the trick of making a .dvi version and having xdvi produce the .pk files. This is because the first plain tex example expects fonts at 600dpi, and the ConTeXt version at 720dpi. No doubt these defaults are configurable, but I haven't looked into that. If you set font sizes, say with \setupbodyfont[30pt] you must again generate the .pk files. This is cumbersome, but needs to be done only once for each font and size.
## Typography
I use TeX to typeset books for print publication. Just as I am a beginning TeX user, so am I a beginning typographer and book designer (but a very serious one).
My interest is in traditional forms suitable for novels and the like. All the examples I give below are intended for that use. I have generally followed the advice given by these authors:
• Robert Bringhurst, The Elements of Typographic Style
• Jan Tschichold, The Form of the Book
• Geoffrey Dowding, Finer Points in the Spacing & Arrangement of Type
### Tight word spacing
Do not insert extra space at the end of sentences. Use small paragraph indententation and do not use vertical spacing between parapgraphs.
In plain TeX, tight spacing at the end of sentences is called \frenchspacing.
\setupspacing[packed] % normal word space at the end of sentences
\setupindenting[small] % small paragraph indent; about 1em?
\setupwhitespace[none] % no space between paragraphs
### Indenting
You can bring in the margins for a quotation or extract with \startnarrower ... \stopnarrower. The amount of indentation is in predefined units which are established separately for the left, right, and middle (which does both left and right by the same amount). For example, I could do something like:
\setupnarrower[left=4em,right=2in,middle=3cm]
And then:
\startnarrower[3*left] % indents left margin 12em
\startnarrower[right] % indents right margin 2 inches
\startnarrower[2*middle] % indents both margins 6 cm
The manual shows how to combine parameters.
\startnarrower without parameters is the same as \startnarrower[middle].
There is a reasonable default indentation size, but I don't know its exact dimension.
### Using smaller symbols
Dowding says that "&" can be substituted for "and" wherever doing so improves the page. This is not a license to globally replace all such occurances; I use the technique only as a last resort to eliminate an overfull box.
In the fonts I have used the full-height "&" seems too large in body text, so I use a smaller version:
\def\Ampersand{{\tfx \&}}
The italic "&" is often a fancier glyph and might be useful; or it might be too fancy for body text use. I would use the italic version in Computer Modern, but the regular glyph in Adobe Sabon.
I also think the full-size "$" is too big in body text, and use a reduced version: \def\Dollar{{\tfx \$}}
### Dashes
The em-dash is too wide. Use a spaced en-dash instead: " -- ". Depending on the context, it might be necessary to use a non-breaking space (~) on either side to prevent an unwanted line break.
### Letterspacing capitals and small caps
The experts say that strings of uppercase and small-cap words should be slightly letterspaced. I find that a very little spacing is "plenty." Sometimes it does not look right at all, and I omit it. Note that it is an offence against typography to letterspace lowercase letters.
Since getting a tip from Hans Hagen, I have used these macros:
\def\CapStretchAmount{.08em}
\def\CapStretch#1{\def\stretchedspaceamount{\CapStretchAmount}\stretchednormalcase{#1}}
Which is used as so:
\CapStretch{\sc The King in Yellow}
### Margin kerning: Hanging punctuation and protruding characters
The typography references say that a justified margin does not look "optically" straight when the characters are "mechanically" aligned to that margin, because some characters are too light to color the margin. The margin looks straighter if they are pushed farther into it.
I have seen very few examples of this technique in the real world (other than photos of Gutenberg's Bible) so it is hard to judge its proper use. Experimentation and considered judgement are required.
The technique is supported by pdfTeX and ConTeXt. See Hàn Thê Thành's dissertation: Micro-typographic extensions to the TEX typesetting system, and Fonts in ConTeXt (mfonts.pdf).
Note that in TeX the technique does not merely stretch the whitespace between words; it actually enters into the line-breaking algorithm and can greatly alter a paragraph's setting.
ConTeXt comes with a couple of prededefined settings. You can see the definitions in type-exa.tex and hand-def.tex. To move the small puncuation marks a full em into the margin, use:
\usetypescript [serif,sans,mono] [hanging] [pure]
To use a slightly less drastic style which also shifts alphabetic characters very slightly, use:
\usetypescript [serif,sans,mono] [hanging] [thanh]
Margin kerning is enabled with something like:
\usetypescript [serif,sans,mono] [hanging] [thanh]
\usetypescriptfile[type-sabon]
\usetypescript[Sabon]
\setupbodyfont[Sabon]
\setupalign[hanging]
Important: The case for the default font, Computer Modern, is more complicated. Hanging alignment must be defined before the font is loaded, but Computer Modern is loaded before our definitions. The solution is to load it again after the definitions:
\setupfontsynonym[cmr10][handling=pure]
\setupfontsynonym[Serif][handling=pure]
\setupfonthandling[normal][left=1,right=1]
\usetypescript[cmr]
\setupbodyfont[10pt]
You can customize your own settings. In fact, different fonts need different settings. For example, I added these lines to my type-sabon.tex file (stolen from hand-def.tex, still to be adapted):
\startfonthandling [sabon]
\defineprotrudefactor ! 0 .2
\defineprotrudefactor ' 0 .7
\defineprotrudefactor .7 0
\defineprotrudefactor ( .05 0
\defineprotrudefactor ) 0 .05
\defineprotrudefactor [ .05 0
\defineprotrudefactor ] 0 .05
\defineprotrudefactor , 0 .7
\defineprotrudefactor - 0 .7
\defineprotrudefactor . 0 .7
\defineprotrudefactor : 0 .5
\defineprotrudefactor ; 0 .5
\defineprotrudefactor rightupperninequote 0 .5
\defineprotrudefactor leftupperninequote .5 0
\defineprotrudefactor endash 0 .3
\defineprotrudefactor emdash 0 .2
\defineprotrudefactor hyphen 0 .7
\defineprotrudefactor A .05 .05
\defineprotrudefactor F 0 .05
\defineprotrudefactor J .05 0
\defineprotrudefactor K 0 .05
\defineprotrudefactor L 0 .05
\defineprotrudefactor T .05 .05
\defineprotrudefactor V .05 .05
\defineprotrudefactor W .05 .05
\defineprotrudefactor X .05 .05
\defineprotrudefactor Y .05 .05
\defineprotrudefactor k 0 .05
\defineprotrudefactor r 0 .05
\defineprotrudefactor t 0 .05
\defineprotrudefactor v .05 .05
\defineprotrudefactor w .05 .05
\defineprotrudefactor x .05 .05
\defineprotrudefactor y .05 .05
% accented chars omitted from this example
\stopfonthandling
\starttypescript [serif] [hanging] [sabon]
\setupfontsynonym [Serif] [handling=sabon]
% not handling these yet
%\setupfontsynonym [SerifBold] [handling=bold]
%\setupfontsynonym [SerifSlanted] [handling=slanted]
%\setupfontsynonym [SerifItalic] [handling=italic]
%\setupfontsynonym [SerifBoldSlanted] [handling=boldslanted]
%\setupfontsynonym [SerifBoldItalic] [handling=bolditalic]
\stoptypescript
Using these custom settings is just a matter of:
\usetypescriptfile[type-sabon]
\usetypescript [serif] [hanging] [sabon]
\usetypescript[Sabon]
\setupbodyfont[Sabon]
\setupalign[hanging]
## ConTeXt Techniques
### Using \definestartstop for blockquotes
New block structures can be defined with \definestartstop. For example, I use block quotes in text, and want:
• a blank line before and after
• an indent on the left
• ragged right justification
I define this with:
\definestartstop[blockquote][
before={\blank
\startnarrower[left]
\startalignment[right]}, % I lost this comma once and spent a day looking for it
after={\stopalignment
\stopnarrower
\blank}]
Then, using a block quote is just a matter of:
\startblockquote
...lots of text here
\stopblockquote
### Margin notes
Here is how I use margin notes.
First, reserve some space for them:
\definepapersize[TradePaper][width=6in,height=9in]
\setuplayout[backspace=0.9375in, width=3.25in,
rightmargindistance=.25in, rightmargin=1.125in,
leftmargindistance=.25in, leftmargin=1.125in]
\setuppagenumbering[alternative=doublesided]
I define a useful macro:
% marginal note, takes buffer name as argument
\def\MN#1{\strut\inmargin{\getbuffer[#1]}\strut}
Note: I'm not sure the \strut macros are required, but I put them in during development and have left them.
I keep one document containing all of my margin notes as buffers, for example:
\startbuffer[nebulae-m51]
\Messier{51} is in Canes Venatici and is about {\os 35} million
light years distant.
\stopbuffer
Then in the main document I place the note using the buffer name:
This form, previously known in Lord Rosse's great \quote{Whirlpool
be exceptional; now the photographs, far excelling telescopic views in
the revelation of nebular forms, showed the spiral to be the typical
shape.
Here are sample pages showing how it comes out. Hint: best viewed with "Continuous -- Facing" in Adobe Acrobat Reader.
Note: I use the named buffers because it helps organize a large project. You can use \inmargin directly, supplying the note text as the argument.
Note: I put \MN at the end of the source lines to make them easy to find when browsing with an editor. Perhaps that is wrong; it might be better to put them in line and adjacent to a following work like so:
had been supposed to \MN{nebulae-m51}be exceptional
This is based on my experience with \index placement where care must be taken so that the macros do not disturb line breaking. That was what I was working on when I put the (possibly unneeded) \strut macros in my \MN macro.
Often I need a Table of Contents where the entries are formatted differently depending on the part of the document they refer to. I first define some variations of \chapter so that each type has its own list:
\def\Midpoint{\char183}
\def\FrontChapterCommand#1#2{\startframedtext[frame=off, width=3.25in,
offset=0pt, align=middle]#2\stopframedtext}
[number=yes,
style={\switchtobodyfont[15pt]},
page=yes,
after={\blank[20pt]},
align=middle,
command=\FrontChapterCommand]
\def\BackChapterCommand#1#2{\startframedtext[frame=off, width=3.25in,
offset=0pt, align=middle]#2\stopframedtext}
[number=yes,
style={\switchtobodyfont[15pt]},
page=yes,
after={\blank[20pt]},
align=middle,
command=\BackChapterCommand]
\def\ChapterCommand#1#2{\startframedtext[frame=off, width=3.25in,
offset=0pt, align=middle, margin=no]#1~{\Midpoint}~#2\stopframedtext}
[number=yes,
style={\switchtobodyfont[15pt]},
page=yes,
after={\blank[20pt]},
align=middle,
command=\ChapterCommand]
\def\TitleCommand#1#2{\startframedtext[frame=off, width=3.25in,
offset=0pt, align=middle]#2\stopframedtext}
[number=yes,
style={\switchtobodyfont[15pt]},
page=yes,
after={\blank[20pt]},
align=middle,
command=\TitleCommand]
In the document I use the types of chapter as needed:
\FrontChapter{Introduction to the Annotated Edition}
...
\FrontChapter{Preface}
...
\startbodymatter
\chapter{The Windows of Absolute Night}
...etc...
\stopbodymatter
\BackChapter{Index}
...
\def\ContentFormat#1#2#3%
{\startframedtext[frame=off, width=3.25in, offset=0pt]#1~{\Midpoint}~#2~{\Midpoint}~{\os #3}\stopframedtext}
\def\FrontContentFormat#1#2#3%
{\startframedtext[frame=off, width=3.25in, offset=0pt]#2~{\Midpoint}~{\os #3}\stopframedtext}
\def\BackContentFormat#1#2#3%
{\startframedtext[frame=off, width=3.25in, offset=0pt]#2~{\Midpoint}~{\os #3}\stopframedtext}
\title[Contents]{Contents}
\placelist[FrontChapter]
[criterium=content,
alternative=none,
command=\FrontContentFormat]
\placelist[chapter]
[criterium=content,
alternative=none,
command=\ContentFormat]
\placelist[BackChapter]
[criterium=content,
alternative=none,
command=\BackContentFormat]
Which produces something like this:
Contents
Introduction to the Annotated Edition * 5
Preface * 12
1 * The Windows of Absolute Night * 15
2 * Star-Clouds, Star-Clusters, and Star-Streams * 26
3 * Stellar Migrations * 41
4 * The Passing of the Constellations * 52
5 * Conflagrations in the Heavens * 63
6 * Explosive and Whirling Nebulae * 76
7 * The Banners of the Sun * 91
8 * The Zodiacal Light Mystery * 103
9 * Marvels of the Aurora * 113
10 * Strange Adventures of Comets * 125
11 * Meteors, Fire-Balls, and Meteorites * 138
12 * The Wrecking of the Moon * 154
13 * The Great Mars Problem * 168
14 * The Riddle of the Asteroids * 180
Index * 189
Note: in this example the FrontChapter and BackChapter have the same structure, but they could have been different. Any number of lists can be used.
### Dropped caps
The ConTeXt source file supp-fun.tex contains macros for formatting dropped capital initials. For example, see the sample pages referenced previously. The first text line was formatted with:
\def\MyDroppedCaps%
{\DroppedCaps
{} {texnansi-sar} {2\baselineskip} {2pt} {1\baselineskip} {2}}
...
\MyDroppedCaps O{\sc ne} of the most surprising triumphs of celestial photography was
See the source code for documentation. Briefly, \MyDroppedCaps says:
• Use my Adobe Sabon Roman (texnansi-sar) font
• Make the letter two lines (2\baselineskip) high
• Offset text from the letter 2pts horizontally
• Offset the letter 1 line vertically
• Indent two lines following the letter
Note that if you are using the typescript definitions described elsewhere in this document, this macro works just as well and is typeface independent:
\def\MyDroppedCaps%
{\DroppedCaps
{} {Serif} {2\baselineskip} {2pt} {1\baselineskip} {2}}
### Positioning graphics with layers
It is possible to directly position graphics by x-y coordinates on a page. I use this for creating book covers, as in this thumbnail graphic. This is the source for that image:
\\definepapersize[TradePaper][width=6in,height=9in]
\setuplayout[backspace=0in, width=6in]
\setupcolors[state=start]
\input color
\useexternalfigure[cover-front-background][cover-front-background][type=pdf, width=6in]
\useexternalfigure[m51][m0051][type=png, width=2.6784in, height=3.9672in]
\useexternalfigure[daniels][daniels][type=png, width=1.6049in, height=4.795in]
\useexternalfigure[theophilus][theophilus][type=png, width=2.6784in, height=2.43280in]
\useexternalfigure[mars][marsphoto][type=png, width=1.6049in, height=1.6049in]
\definelayer[cover-front-background]
\definelayer[m51]
\definelayer[daniels]
\definelayer[theophilus]
\definelayer[mars]
\defineoverlay[cover-front-background][\composedlayer{cover-front-background}]
\defineoverlay[m51][\composedlayer{m51}]
\defineoverlay[daniels][\composedlayer{daniels}]
\defineoverlay[theophilus][\composedlayer{theophilus}]
\defineoverlay[mars][\composedlayer{mars}]
\setupbackgrounds[page][background={cover-front-background,m51,daniels,mars,theophilus}]
\setlayer[cover-front-background][x=0in,y=0in]{\externalfigure[cover-front-background]}
\setlayer[daniels][x=0.8333in,y=1.5in]{\externalfigure[daniels]}
\setlayer[m51][x=2.5382in,y=1.5in]{\externalfigure[m51]}
\setlayer[theophilus][x=2.5382in,y=5.5672in]{\externalfigure[theophilus]}
\setlayer[mars][x=0.8333in,y=6.395in]{\externalfigure[mars]}
\starttext
...lettering...
\stoptext
The above is perhaps confusing because I reuse the same labels for different purposes: graphics, layers, overlays. ConTeXt doesn't mind, so it is convenient in use, but not in learning.
I believe names like these would work as well and possibly be more intelligible (not tested):
\useexternalfigure[mars-graphic][marsphoto][type=png, width=1.6049in, height=1.6049in]
\definelayer[mars-layer]
\defineoverlay[mars-overlay][\composedlayer{mars-layer}]
\setupbackgrounds[page][background={...,mars-overlay,...}]
\setlayer[mars-layer][x=0.8333in,y=6.395in]{\externalfigure[mars-graphic]}
Note: I did not see a way to have both color and overlay backgrounds, so I created cover-front-background.pdf which is just a blank page with the proper color. I include it as the first overlay and the others get placed on top of it.
### \index placement
This is a small issue but I spent a bit of time on it. The first time I added \index entries to my document I noticed that lines in some of the paragraphs were breaking differently, and not as well as before. Hans Hagen explained:
List enties, index entries, color changes, marks, etc, all introduce nodes in the MVL. Since tex cannot look back when such a node is encountered, it will badly interfere with spacing. Also, since you want an index on the page where you are, by default a nobreak is added, which also interferes with spacing.
The solution is simple: attach the index entry to the word that it belongs to.
So, do not do this:
the one in the constellation Triangulum. \index{Triangulum} % WRONG
the one in the constellation \index{Triangulum}Triangulum. % Correct
### Passing variables on the command line
You can pass command-line variables to a TeX job and read them with the \envvar macro, which takes two arguments:
1. The name of the variable.
2. Value to use if the variable is not defined.
For example, if I have this in my job:
\envvar{alpha} {there is no alpha}
I can pass a value with:
texexec --arguments="alpha=Hello I am here"
Multiple variables can be specified like so:
texexec --arguments="alpha=Hello I am here,beta=Goodbye I am going"
Question: It seems to me that a comma cannot be part of the variable text, else the parser becomes confused. Is there another level of quoting that would allow this?
### Line numbers
Lines can be numbered with \startlinenumbering ... \stoplinenumbering around the text of interest.
However, there is a limit to how many lines can be numbered because the technique builds a vbox which has a maximum size. Exceeding that generates a run-time error. The solution is simple: every so often break the text into blocks with \startlinenumbering[continue] ... \stoplinenumbering. This will produce continuous line numbering without limit.
### Using italics for default emphasis
By default, for fonts that have slanted variants, the \em directive will produce slanted characters. If you would rather have italic characters:
\setupbodyfontenvironment[default][em=italic]
Note that in many typefaces the slanted definitions are synonyms for the italic variants, so that \em and \it and \sl all produce the same italic characters.
## FontSite-500 CD
FontSite sells a large collection of Type1 and TrueType fonts for \$29.95. You can see both PDF and text catalogs of the fonts included.
I've developed a set of scripts to automatically define these fonts for ConTeXt, using texfont. All of the scripts described in this section are packaged together into this archive. (On Linux unpack with unzip -a).
I was inspired by Christopher League's TeX support for the FontSite 500 CD which provides LaTeX support for the fonts. He also has a PDF catalog of the fonts his package supports.
Important Note: My effort is much less ambitious than Christopher League's. Where he has collected the fonts into useful family packages, I have simply done a direct coversion of the FontSite directories into a form that ConTeXt can access. Making more complex family definitions requires hand editing that I do not have time for. However, the basic definitions provide the components needed for family definitions and I will try to provide better examples of such later.
The effort is limited by what can reasonably be automated:
• The original font directories each have at most four font files. With some effort these are mapped to regular, italic, bold and bold-italic styles.
• All fonts are represented as Serif in the typescripts, even the sans serif, blackletter and decorative fonts. I think this is reasonable, if inelegant. None of the fonts fit into a multi-style family, so switching between \rm, \ss, etc, is not important.
The fonts are mainly derived from Softmaker/ATF. Several are "near" copies of famous fonts and are given new names. Apparently this is legal. Whether or not it is ethical I will leave for another day. Here is a table giving the FontSite and more common names of some of the fonts (mostly taken from Christopher League's notes). If anyone knows of other "alias" copies on the CD, please let me know.
FontSite Common name
Avalon Avant Garde Gothic
Basel Basilia
Benjamin Gothic Benguiat Gothic
Bergamo Bembo
Chantilly Gill Sans
Function Futura
Gareth Galliard
Glytus Glypha
Jenson Recut Centaur
Jessica Joanna
Latino Melior
Melville Murray Hill ATF
Microsquare Eurostyle, Microgamma
Opus Optima
Savoy Sabon
Schnittger Schneidler
Serific Serifa
Struktur Syntax
Typewriter American Typewriter ITC
Unitas Univers
University Old Style Berkeley Old Style
I use Python programs to generate shell scripts which do the actual installation. I have included the generated shell scripts themselves for those who don't want to run Python. They are specific to my Linux system, but might be useful to someone who wanted to do global search-and-replace on the directory names, or to cut out the sections dealing with specific fonts and experiment with them. Note that it would be easy to adapt the Python programs to do the installation directly, but I thought it would be convenient to have the shell scripts.
A note on encoding: The Python scripts take an optional --encoding= flag. texnansi is the default and is the only encoding I have used.
I also include the generated .map and .tex typescript files so you can see what is in them. Obviously, you need to buy the FontSite CD to get the .pfb and .afm files. Running texfont will recreate the .map files, but after that you can use the supplied .tex typescript files or generate your own with the scripts.
My invoice from FontSite contained a link to two updated fonts. Instructions for dealing with them are given below.
### Archive file list
Here is a summary of the files in the archive:
fontsite.py
Generate a shell script which will run texfont on a series of font directories. Run without parameters or with --help to see a usage display.
fontsite-cd.sh
Shell script generated by fontsite.py which installs all fonts on the FontSite CD.
fontsite-opussmallcaps.sh, fontsite-urwgrotesk.sh
Shell scripts generated by fontsite.py which install updated fonts downloaded from the FontSite web pages.
fontsite-typescripts.py
Create ConTeXt .tex typescript files for all FontSite fonts in a directory struture. Run without parameters or with --help to see a usage display.
fontsite-sampler.py
Generate a .tex file which prints a sample line for each FontSite font. Does not use typescripts in an effort to save time and memory. Run with --help to see a usage display.
fontsite-sampler-ah.tex, fontsite-sampler-iz.tex
These are outputs from fontsite-sampler.py. I use two output files because all the fonts in one job together cause some sort of overflow and I'm too lazy to figure out how to expand my TeX resources. In these versions I have commented out the fonts that aren't working yet.
config/*
The pdftex .map files generated by texfont during the installation.
generic/*
The ConTeXt typescript .tex files generated by fontsite-typescripts.py during the installation.
### Installation
Here is how I installed the FontSite fonts on my system. There are some error messages; see Problems below.
Note these directories:
~
/home/wmcclain, my home directory
~/texmf
my local TeX tree
~/install/fonts/fontsite
contains the Python programs
~/install/fonts/fontsite/logs
working directory, contains shell scripts, logs, and texfont sample job files
/tmp/fonts
scratch directory for temporary files
This will run texfont on all Type1 fonts on the CD. It copies the .pfb files and creates the .tfm and .map files:
mount /cdrom
cd ~/installs/fonts/fontsite/logs
rm /tmp/fonts/*
../fontsite.py --sourcepath="/cdrom/Type 1" --fontroot=~/texmf --scratch=/tmp/fonts > fontsite-cd.sh
chmod +x fontsite-cd.sh
./fontsite-cd.sh > fontsite-cd.log 2>&1
umount /cdrom
I downloaded the FontSite archive of two updated fonts to ~/installs/fonts/fontsite/updated_fonts_PC.zip. Note there is a trick to unzipping this file. All the contents are marked "text" but the .pfb files must be unzipped as binary and the .afm files must be unzipped as text. We do it in two steps:
cd ~/installs/fonts/fontsite
unzip updated_fonts_PC.zip *.pfb
unzip -a updated_fonts_PC.zip *.afm
The update files are not named consistently with the CD and we have to fix the names. This is easier than making fontsite.py try to understand all the variations.
Note that "Opus Sm Caps" had some name changes from the CD, so we first delete the original files in the ~/texmf tree, else confusion reigns.
Fix the names and install the fonts as for the CD:
cd "updated_fonts_PC/Opus Sm Caps"
mv OPUSSCB_.pfb OPUSSCB_.PFB
mv OPUSSC__.pfb OPUSSC__.PFB
cd ~/installs/fonts/fontsite/logs
../fontsite.py --sourcepath="/home/wmcclain/installs/fonts/fontsite/updated_fonts_PC/Opus Sm Caps" --fontroot=~/texmf --scratch=/tmp/fonts > fontsite-opussmallcaps.sh
chmod +x fontsite-opussmallcaps.sh
rm -r ~/texmf/fonts/*/fontsite/opussmcaps
./fontsite-opussmallcaps.sh > fontsite-opussmallcaps.log 2>&1
cd "/home/wmcclain/installs/fonts/fontsite/updated_fonts_PC/URWGrotesk/"
mkdir afm
mv *.afm afm
mv URWGBI__.pfb URWGBI__.PFB
mv URWGB___.pfb URWGB___.PFB
mv URWGHHI_.pfb URWGHHI_.PFB
mv URWGHH__.pfb URWGHH__.PFB
mv URWGI___.pfb URWGI___.PFB
mv URWGRG__.pfb URWGRG__.PFB
mv URWGSCB_.pfb URWGSCB_.PFB
mv URWGSCRG.pfb URWGSCRG.PFB
cd ~/installs/fonts/fontsite/logs
../fontsite.py --sourcepath="/home/wmcclain/installs/fonts/fontsite/updated_fonts_PC/URWGrotesk" --fontroot=~/texmf --scratch=/tmp/fonts > fontsite-urwgrotesk.sh
chmod +x fontsite-urwgrotesk.sh
./fontsite-urwgrotesk.sh > fontsite-urwgrotesk.log 2>&1
Lines in the FSBaskerville .map file were missing the postscript name field. This confuses fontsite-typescripts.py so I make a new version of the file. However: the font doesn't work, so there is another problem as yet unresolved.
cat > ~/texmf/pdftex/config/texnansi-fontsite-fsbaskerville.map <<EOD
% Postscript names added by Bill McClain, Oct 18 2002
%
% This file is generated by the TeXFont Perl script.
%
% You need to add the following line to pdftex.cfg:
%
%
% Alternatively in your TeX source you can say:
%
%
% In ConTeXt you can best use:
%
EOD
Same for Toxica. Also doesn't work.
cat > ~/texmf/pdftex/config/texnansi-fontsite-toxica.map <<EOD
% Postscript name added by Bill McClain, Oct 18 2002
%
% This file is generated by the TeXFont Perl script.
%
% You need to add the following line to pdftex.cfg:
%
% map +texnansi-fontsite-toxica.map
%
% Alternatively in your TeX source you can say:
%
% \pdfmapfile{+texnansi-fontsite-toxica.map}
%
% In ConTeXt you can best use:
%
texnansi-raw-toxica Toxica 4 < toxica__.pfb texnansi.enc
EOD
Generate the ConTeXt typescript file for every FontSite font. Note that we have to specify directories within the ~/texmf tree.
cd ~/installs/fonts/fontsite/logs
../fontsite-typescripts.py --maproot=~/texmf/pdftex/config --tfmroot=~/texmf/fonts/tfm/fontsite --outdir=~/texmf/tex/generic/
texhash
Create jobs to display a sample line of each font. These jobs don't use the typescripts, but the typescript techniques described elsewhere in this document may now be used to access the fonts.
ls ~/texmf/tex/generic/type-fontsite-[a-h]*.tex | ./fontsite-sampler.py --size=30 --phrase="Curiosities of the Sky" > fontsite-sampler-ah.tex
ls ~/texmf/tex/generic/type-fontsite-[i-z]*.tex | ./fontsite-sampler.py --size=30 --phrase="Curiosities of the Sky" > fontsite-sampler-iz.tex
### Problems
• When running texfont many fonts produce messages like this:
kern char not found
KPX .notdef A -33
I presume these are diagnostics from afm2tfm which refer to missing glyphs. The resulting fonts are still usuable, but perhaps not complete?
• Font "Celt" does not work. When I access it with \font= or by running the example job that texfont produces I get:
Error: pdfetex (file /home/wmcclain/texmf/fonts/type1/fontsite/celt/celt____.pf
b): buffer overflow [8192 bytes]
Perhaps I need to expand some resource?
• As mentioned in the Installation section above, these fonts did not have postscript names in their .map files:
• Toxica
I added postscript name fields, but when accessing with \font= the output is blank, and when running the example job that texfont produces I get:
! Arithmetic overflow.
\dogetnoflines ...\noflinesheight \openlineheight
\noflines \noflinesheight ...
\setvsize ...linsertionheight \getnoflines \vsize
\vsize \noflines \openline...
\flushcolumnedpage ...height \zeropoint \setvsize
\dosomebreak \nobreak \pre...
\balancedmulticolumnsout ...ue \flushcolumnedpage
\allowbreak \egroup
<output> {\balancedmulticolumnsout
}
...
Note: the "FSBaskerville-Expert" fonts are ok, and the collection also contains "NewBaskerville" fonts which work.
• The font "DeannaBorders" also shows the previous errors, even though its .map file looks ok.
## Old Installation
I originally used the TeX installation that came with the SuSE Linux distribution. I have since switched to the TexLive distribution to be more in line with the rest of the TeX world.
Here are my original installation notes. SuSE 8.1 was the last time I used the TeX provided with that installation.
SuSE Linux comes with both ConTeXt and pdfTeX, but these packages are updated rather frequently and it is necessary to upgrade without waiting for SuSE.
These notes are not a replacement for the real installation docs! I just show what I actually do when upgrading.
I do the upgrade in the main TeX tree: /usr/share/texmf. If I were ambitious I would test in some auxiliary directory first, but I haven't had much trouble yet. I have backups and am able to reinstall pretty quickly.
### ConTeXt
su root
mv cont-tmf.zip /usr/share/texmf
cd /usr/share/texmf
rm /usr/share/texmf/tex/context/base/*
unzip -a -L -o cont-tmf.zip # overwrites existing files!
# SuSE wants the executables here...
# Note: in SuSE 7.2 the files were placed in .../i386-linux-glibc/
# As of SuSE 8.1, they are in .../i386-linux-libc6/
#
# Also in 8.1, the links seemed incorrect to me, so I have added
# a few new steps to try to correct them.
#
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/texexec
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/texshow
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/texutil
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/texfont
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/texfind
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/fdf2tan
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/makempy
rm /usr/share/texmf/teTeX/bin/i386-linux-libc6/mptopdf
cp context/perltk/texexec.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/texexec
cp context/perltk/texshow.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/texshow
cp context/perltk/texutil.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/texutil
cp context/perltk/texfont.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/texfont
cp context/perltk/texfind.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/texfind
cp context/perltk/fdf2tan.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/fdf2tan
cp context/perltk/makempy.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/makempy
cp context/perltk/mptopdf.pl /usr/share/texmf/teTeX/bin/i386-linux-libc6/mptopdf
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/texexec
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/texshow
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/texutil
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/texfont
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/texfind
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/fdf2tan
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/makempy
chmod +x /usr/share/texmf/teTeX/bin/i386-linux-libc6/mptopdf
# Edit texexec.ini afterwards?
cp /usr/share/texmf/context/config/texexec.rme /usr/share/texmf/context/config/texexec.ini
# Edit cont-sys.tex afterwards?
cp /usr/share/texmf/tex/context/user/cont-sys.rme /usr/share/texmf/tex/context/user/cont-sys.tex
texhash
texexec --make en # en = english
texhash
exit # from "su root"
### pdfTeX
cp pdftex-20010417.tgz /tmp # or whatever the latest snapshot is called
cd /tmp
tar zxvf pdftex-20010417.tgz # or whatever the latest snapshot is called
cd src
configure
cd texk/web2c
make pdftexbin # may need "tangle" from previous build
su root
cp *.pool /usr/share/texmf/web2c
# SuSE wants the executables here...
# Note: in SuSE 7.2 the files were placed in .../i386-linux-glibc/
# As of SuSE 8.1, they are in .../i386-linux-libc6/
#
cp pdftex /usr/share/texmf/teTeX/bin/i386-linux-libc6
cp pdfetex /usr/share/texmf/teTeX/bin/i386-linux-libc6
cp ttf2afm /usr/share/texmf/teTeX/bin/i386-linux-libc6
# first time only, add this to /etc/profile.local:
#
# export TEXMFCNF=kpsewhich -show-path=.cnf
texhash
texexec --make en
texhash
exit # from "su root"
` | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9356729984283447, "perplexity": 10397.9286722607}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-36/segments/1471982291015.10/warc/CC-MAIN-20160823195811-00142-ip-10-153-172-175.ec2.internal.warc.gz"} |
https://www.transtutors.com/questions/accountant-project-49698.htm | # accountant project
. THIS TEAM ASSIGNMENT IS DUE IN THE DROP BOX ON OR BEFORE: MARCH 17th BEFORE 11:00pm 1. Laura Anderson has just been assigned as the senior accountant on the audit of Larsen Manufacturing Company. Laura currently is planning the audit and has been considering what procedures to perform in examining the company's inventories of raw materials, work-in-process, and finished goods. She has determined that the calculation of certain ratios and other financial analysis techniques will prove useful to her in deciding how to approach the audit of the company's inventory accounts. Write a short paper in which you identify and discuss the ratios to be calculated and the factors to be considered in Laura's analysis of the company's inventory accounts. 2. A large body of scholarly literature exists relating to the subject of choices of accounting methods. The choice of depreciation methods is an example of these accounting choices. The choice of depreciation method affects several ratios. Required: a. Explain which financial statement ratios are affected by the choice of depreciation methods, with specific attention to the effects of straight-line vs. accelerated depreciation on the ratios. b. Comment on the effects on financial statement users of the issues discussed in part 1. Page 2 of 3 3. The following are comparative data for Gates Company for the three-year period 2006-2008: Income Statement Data 2008 2007 2006 Net sales (80% are on credit each period) ......................... $900,000$720,000 $840,000 Net purchases ................... 480,000 390,000 330,000 Balance Sheet Data Accounts receivable, December 31$150,000 $132,000$126,000 Compute the following measurements for 2008 and 2007: (1) The receivables turnover rate. (2) The average collection period for accounts receivable. 4. Income statements for LaRue Co. show the following: 2008 2007 2006 Sales (net) ..................... $500,000$400,000 $350,000 Cost of goods sold: Beginning inventory ............. 110,000 90,000 20,000 Purchases ....................... 420,000 330,000 370,000$530,000 $420,000$390,000 Ending inventory ................ 170,000 110,000 90,000 360,000 310,000 300,000 Gross profit .................... $140,000$ 90,000 $50,000 From the data presented, calculate the following ratios for 2008 and 2007: (1) Inventory turnover rate. (2) Number of days' sales in inventories. (3) Gross profit margin on sales. Page 3 of 3 5. Comparative data for Kerry Inc. for the two-year period 2007-2008 are given as follows: Income Statement Data 2008 2007 Net sales ...................................$1,400,000 $800,000 Cost of goods sold .......................... 840,000 440,000 Gross profit on sales .......................$ 560,000 $360,000 Selling, general, and other expenses ........ 400,000 130,000 Income tax expense .......................... 40,000 30,000 Net income ..................................$ 120,000 $200,000 Dividends paid .............................. 80,000 80,000 Net increase in retained earnings ...........$ 40,000 $120,000 Balance Sheet Data 2008 2007 Assets Current assets ..............................$ 540,000 $440,000 Land, buildings, and equipment .............. 800,000 720,000 Total assets ................................$1,340,000 $1,160,000 Liabilities and Stockholders' Equity Current liabilities .........................$ 300,000 $240,000 Bonds payable (8%) .......................... 320,000 320,000 Common stock ($5 par) ....................... 480,000 400,000 Retained earnings ........................... 240,000 200,000 Total liabilities and stockholders' equity .. $1,340,000$1,160,000 From the given data, compute the following for 2008 and 2007: (1) Current ratio. (2) Net profit margin on sales. (3) Gross profit margin on sales. (4) Debt-to-equity ratio. (5) Times interest earned. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.19363047182559967, "perplexity": 5405.805758917449}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-43/segments/1539583510893.26/warc/CC-MAIN-20181016221847-20181017003347-00188.warc.gz"} |
https://zbmath.org/?q=an:0932.60041 | ×
# zbMATH — the first resource for mathematics
Logarithmic multifractal spectrum of stable occupation measure. (English) Zbl 0932.60041
Summary: For a stable subordinator $$Y_t$$ of index $$\alpha$$, $$0<\alpha < 1$$, the occupation measure $$\mu (A) = |\{t\in [0,1] : Y_t \in A\}|$$ is known to have (with probability 1) the property that $\liminf_{r\downarrow 0} \frac {\ln \mu (x-r,x+r)}{\ln r} = \alpha , \quad \forall x\in Y[0,1].$ In order to obtain an interesting spectrum for the large values of $$\mu (x-r,x+r)$$, we consider the set $B_{\theta} = \Big {\{} x\in Y[0,1]:\limsup_{r\downarrow 0} \frac {\mu (x-r,x+r)}{c_{\alpha} r^{\alpha} (\ln (1/r))^{1-\alpha}} = \theta \Big {\}},$ where $$c_{\alpha}$$ is a suitable constant. It is shown that $$B_{\theta} = \emptyset$$ for $$\theta >1$$, and $$B_{\theta} \not = \emptyset$$ for $$0\leq \theta \leq 1$$; moreover, dim $$B_{\theta} = \text{Dim } B_{\theta} = \alpha (1-\theta ^{1/(1-\alpha)})$$.
##### MSC:
60G17 Sample path properties
##### Keywords:
stable subordinators; multifractals; occupation measures
Full Text:
##### References:
[1] Hawkes, J., A lower lipchitz condition for the stable subordinator, Z. wahr. verw. geb., 17, 23-32, (1971) · Zbl 0193.45002 [2] Hu, X.; Taylor, S.J., The multifractal structure of stable occupation measure, Stochastic process. appl., 66, 283-299, (1997) · Zbl 0888.28004 [3] Orey, S.; Taylor, S.J., How often on a Brownian path does the law of iterated logarithm fail?, Proc. London math. soc., 3, 174-192, (1974) · Zbl 0292.60128 [4] Perkins, E.A.; Taylor, S.J., Uniform measure results for the image of subsets under Brownian motion, Probab. th. rel. fields, 76, 257-289, (1987) · Zbl 0613.60071 [5] Taylor, S.J., Sample path properties of a transient stable processes, J. math. mech., 16, 1229-1246, (1967) · Zbl 0178.19301 [6] Taylor, S.J., The measure theory of random fractals, Math. proc. camb. phi. soc., 100, 383-406, (1986) · Zbl 0622.60021
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.951069712638855, "perplexity": 2247.012596222839}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243989614.9/warc/CC-MAIN-20210511122905-20210511152905-00584.warc.gz"} |
http://mathoverflow.net/questions/79177/l2-boundeness-of-a-sequence | $L^2$ boundeness of a sequence
Let $f_n \in C^2(\bar{\Omega})$ be a sequence satisfying
$\Delta f_n - f_n^3 \to 0 \ \ {\rm in} \ \ L^2(\Omega)$
where $\Omega \subset {\mathbb R}^2$ is bounded and open with a smooth boundary. Is it necessarily true that $\|f_n^3\|_{L^2(\Omega)}$ and $\|\Delta f_n\|_{L^2(\Omega)}$ are uniformly bounded? If not, can you give a counterexample?
If there is a counterexample, I imagine it would involve $f_n$ becoming unbounded on $\partial \Omega$. If so, is it possible that this statement is true for $f_n \in C^2_c(\bar{\Omega})$ (i.e. if $f_n$ all have compact support in $\Omega$.)
The reason I believe it may be true is that the condition $\Delta f_n - f_n^3 \to 0$ seems incompatible with the sequence $f_n$ having an increasing positive interior maximum or a decreasing negative interior minimium as $\Delta f_n$ and $-f_n^3$ would have the same signs and not cancel out. I have tried to come up with counterexamples in one dimension but have had no luck yet.
-
Is "$\Delta$" equal $\partial^2/\partial x^2 + \partial^2/\partial y^2$ or the negative of that? I think both definitions are in use, and the answer to your question might depend on the sign. – Noam D. Elkies Oct 26 '11 at 18:23
Yes, I'm using $\Delta = \partial^2/\partial x^2 + \partial^2/\partial y^2$. I think you are right that the answer would be different with $\Delta$ replaced by $-\Delta$. – Jeff Oct 26 '11 at 19:27
In one dimension $f_n(x) = 2^{1/2} / (x-x_n)$ satisfies $\Delta f_n - f_n^3 = 0$, and if $x_n \rightarrow \partial \Omega$ from the outside then $\|f_n^3\| \rightarrow \infty$. Yes, such $f_n$ are unbounded on $\partial \Omega$. – Noam D. Elkies Oct 26 '11 at 21:26
A counterexample in one dimension: take $\Omega:=(0,1)$ and $f_n(x):=\frac{\sqrt 2}{x+\frac{1}{n}}$. Then $f''_n(x)-f_n^3(x)=0$ while $\| f''_n \| _{2,\Omega}=\|f^3_n\|_{2,\Omega}=O(n^{5/2}) \, .$
Thanks! Nice counterexample. This is kind of what I was expecting, $f_n$ becoming unbounded at the boundary. Any idea what happens if we restrict $f_n$ to have compact support? – Jeff Oct 26 '11 at 21:27
Then if you multiply $\Delta f_n - f_n^3 := h_n\to 0$ in $L^2(\Omega)$ by $f_n$ and integrate on the domain you get $\|\nabla f_n\|^2_2 + \|f_n\|^ 4_ 4 = o(\|f_n\|_2)$, which implies that the LHS goes to zero. – Pietro Majer Oct 26 '11 at 22:01 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9396879076957703, "perplexity": 130.00180800784307}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-15/segments/1397609535095.9/warc/CC-MAIN-20140416005215-00172-ip-10-147-4-33.ec2.internal.warc.gz"} |
https://phys.libretexts.org/TextBooks_and_TextMaps/College_Physics/Book%3A_Spiral_Physics_-_Algebra_Based_(D%E2%80%99Alessandris)/Spiral_Mechanics_(Algebra-Based)/Model_3%3A_The_Particle_Model/04._Conservation/02._Applying_the_Impulse-Momentum_Relation | $$\require{cancel}$$
# 02. Applying the Impulse-Momentum Relation
### Applying the Impulse-Momentum Relation
Let's re-examine the same situation we examined at the beginning of the previous chapter, a rocket launched directly upward with a time-dependent thrust.
A 2.0 kg toy rocket is fitted with an engine that provides a thrust roughly modeled by the function F(t) = (60 N/s) t - (15 N/s2) t2, for 0 < t < 4.0 s, and zero thereafter. The rocket is launched directly upward.
For analysis, we'll apply the impulse-momentum relation between:
Event 1: The instant the rocket leaves the launch-pad
Event 2: The instant the thrust drops to zero.
Remember from last chapter that the rocket does not leave the launch pad until 0.36 s after the engine is ignited.
When the engine shuts off, the rocket is traveling at 42.5 m/s upward.
We could also apply the impulse-momentum relation between:
Event 1: The instant the thrust drops to zero.
Event 2: The instant the rocket reaches its maximum height.
During this interval, the only force acting on the rocket is the force of gravity, and the impulse-momentum relation is:
Thus, the rocket reaches its highest altitude 8.34 s after launch.
It's important to note that when a force is a function of time, it's relatively easy to integrate the function and determine the impulse. However, it should be clear that it would not be easy to determine the work done by a force of this type. Since work is expressed as an integral of a force with respect to a displacement (dr), the force function has to be expressed in terms of position, r. In general, it's not an easy (or sometimes possible) task to "convert" a function of time into a function of position, so work-energy is not a particularly useful way to analyze systems when the forces acting are time dependent. However, if the forces depend upon the position of the object, work-energy is a powerful analysis tool.
### Applying the Work-Energy Relation
A 0.15 kg ball is launched vertically upward by means of a spring-loaded plunger, pulled back 8.0 cm and released. It requires a force of about 10 N to push the plunger back 8.0 cm.
#### The Force Exerted by a Spring
The force that the spring exerts on the ball depends on the amount by which the spring is compressed. The more the spring is compressed, the larger the force it exerts on the ball. A common model is that the force exerted by a spring is directly proportional to the amount of deformation of the spring, in this case compression. Deformation (s) is defined to be the difference between the current length of the spring (L) and the equilibrium length (L0):
If we define the positive coordinate direction to point in the same direction as positive deformation (stretch), then
with the proportionality constant, k, referred to as the spring constant.
For the plunger, since it takes 10 N to compress the spring by 8.0 cm,
For analysis, we'll apply the work-energy relation between:
Event 1: The instant the plunger is released.
Event 2: The instant the ball reaches its maximum height.
For these two events, work-energy looks like this:
To do the integral, we must express Fspring in terms of the variable of integration, r. For the coordinate system chosen, s and r are identical. Also note that the force of the spring and the direction of motion of the ball point in the same direction. Thus, f = 0.
The ball reaches a maximum height of 19 cm above the top of the plunger. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8989483118057251, "perplexity": 425.32938610563025}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-26/segments/1529267863463.3/warc/CC-MAIN-20180620050428-20180620070428-00555.warc.gz"} |
http://link.springer.com/article/10.1007%2Fs10587-008-0081-0 | , Volume 58, Issue 4, pp 1221-1231
# A measure-theoretic characterization of the Henstock-Kurzweil integral revisited
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## Abstract
In this paper we show that the measure generated by the indefinite Henstock-Kurzweil integral is F σδ regular. As a result, we give a shorter proof of the measure-theoretic characterization of the Henstock-Kurzweil integral. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9663201570510864, "perplexity": 1501.0882159613573}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-15/segments/1397609536300.49/warc/CC-MAIN-20140416005216-00408-ip-10-147-4-33.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/quantum-mechanics-commuting-operators-very-quick-question.150119/ | # Quantum Mechanics - Commuting Operators (very quick question)
1. Jan 5, 2007
### Brewer
Just a quickie:
If two operators commute, what can be said about their eigenfunctions?
The only thing I can glem from the chapter in my textbook about this is that the eigenfunctions are equal? Is this right, or have I misread it?
2. Jan 5, 2007
### cristo
Staff Emeritus
If two (Hermitian) operators commute, then there exists a complete set of eigenvectors which is common to both operators.
3. Jan 5, 2007
### Sojourner01
Not to interrupt, but if I were asking this question, I'd be doing so exclusively in terms of wave mechanics. It seems to be the 'mdern' way to ignore matrix mechanics when teaching QM - at least it is for my department. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.825728178024292, "perplexity": 1014.774457392819}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281574.78/warc/CC-MAIN-20170116095121-00271-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://link.springer.com/chapter/10.1007%2F978-3-319-65482-9_62 | Advertisement
# A Hybrid Parallel Search Algorithm for Solving Combinatorial Optimization Problems on Multicore Clusters
• Victoria Sanz
• Armando De Giusti
• Marcelo Naiouf
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10393)
## Abstract
Multicore clusters are widely used to solve combinatorial optimization problems, which require high computing power and a large amount of memory. In this sense, Hash Distributed A* (HDA*) parallelizes A*, a combinatorial optimization algorithm, using the MPI library. HDA* scales well on multicore clusters and on multicore machines. Additionally, there exist several versions of HDA* that were adapted for multicore machines, using the Pthreads library. In this paper, we present Hybrid HDA* (HHDA*), a hybrid parallel search algorithm based on HDA* that combines message-passing (MPI) with shared-memory programming (Pthreads) to better exploit the computing power and memory of multicore clusters. We evaluate the performance and memory consumption of HHDA* on a multicore cluster, using the 15-puzzle as a case study. The results reveal that HHDA* achieves a slightly higher average performance and uses considerably less memory than HDA*. These improvements allowed HHDA* to solve one of the hardest 15-Puzzle instances.
## Keywords
Parallel search algorithms Hybrid programming Multicore cluster Combinatorial optimization problems Hash Distributed A*
## References
1. 1.
Hart, P., et al.: A formal basis for the heuristic determination of minimum cost paths. IEEE Trans. Syst. Sci. Cybern. 4(2), 100–107 (1968)
2. 2.
Russel, S., Norvig, P.: Artificial Intelligence: A Modern Approach, 2nd edn. Prentice Hall, Upper Saddle River (2003)Google Scholar
3. 3.
Kishimoto, A., et al.: Evaluation of a simple, scalable, parallel best-first search strategy. Artif. Intell. 195, 222–248 (2013)
4. 4.
Sanz, V., et al.: Scalability analysis of Hash Distributed A* on commodity cluster: results on the 15-puzzle problem. In: Proceedings of PDPTA 2016, 221–230. CSREA Press, Georgia (2016)Google Scholar
5. 5.
Burns, E., et al.: Best-first heuristic search for multicore machines. J. Artif. Intell. Res. 39(1), 689–743 (2010)
6. 6.
Sanz, V., et al.: On the optimization of HDA* for multicore machines. Performance analysis. In: Proceedings of PDPTA 2014, pp. 625–631. CSREA Press, Georgia (2014)Google Scholar
7. 7.
Sanz, V., et al.: Performance tuning of the HDA* algorithm for multicore machines. In: Computer Science and Technology Series 2015. EDULP, La Plata (2015)Google Scholar
8. 8.
Chow, E., et al.: Assessing performance of hybrid MPI/OpenMP programs on SMP clusters. Technical report, UCRL-JC-143957. Lawrence Livermore National Laboratory, California (2001)Google Scholar
9. 9.
Rabenseifner, R., et al.: Hybrid MPI, OpenMP parallel programming on clusters of multi-core SMP nodes. In: Proceedings of PDP 2009, pp. 427–436. IEEE Computer Society, Washington, D.C. (2009)Google Scholar
10. 10.
Hager, G., et al.: Introduction to High Performance Computing for Scientists and Engineers, 1st edn. CRC Press, Boca Raton (2010)
11. 11.
Kumar, V., et al.: Parallel best-first search of state-space graphs: a summary of results. In: Proceedings of AAAI 1988, pp. 122–127. AAAI Press, California (1988)Google Scholar
12. 12.
Vidal, V., et al.: Parallel AI planning on the SCC. In: 4th Many-Core Applications Research Community (MARC) Symposium, pp. 15–20. Postsdam University Press (2011)Google Scholar
13. 13.
Dijkstra, E.W.: Shmuel Safra’s version of termination detection. EWD-Note 998. Department of Computer Sciences, University of Texas, Austin (1987)Google Scholar
14. 14.
Korf, R.: Depth-first iterative-deepening: an optimal admissible tree search. Artif. Intell. 27(1), 97–109 (1985)
15. 15.
Brüngger, A.: Solving hard combinatorial optimization problems in parallel: two cases studies. Ph.D. thesis, ETH Zurich, Dissertation ETH No. 12358 (1998)Google Scholar
16. 16.
Brüngger, A., et al.: The parallel search bench ZRAM and its applications. Ann. Oper. Res. 90, 45–63 (1999)
## Copyright information
© Springer International Publishing AG 2017
## Authors and Affiliations
• Victoria Sanz
• 1
• 2
• Armando De Giusti
• 1
• 3
• Marcelo Naiouf
• 1
1. 1.School of Computer Sciences, III-LIDINational University of La PlataLa PlataArgentina
2. 2.CICBuenos AiresArgentina
3. 3.CONICETBuenos AiresArgentina | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.804265022277832, "perplexity": 14149.355691852259}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376826145.69/warc/CC-MAIN-20181214162826-20181214184826-00451.warc.gz"} |
http://www.elvastower.com/forums/index.php?/topic/30311-updater-aborts/ | # Elvas Tower: Updater Aborts - Elvas Tower
Page 1 of 1
## Updater Aborts
### #1Genma Saotome
• Group: Owner
• Posts: 11,830
• Joined: 11-January 04
• Gender:Male
• Location:United States
• Simulator:Open Rails
• Country:
Posted 25 May 2017 - 05:11 PM
On occasion the updater aborts -- your problem, my problem, who knows whose problem, doesn't really matter. What does mater is the previous (working) version of the OR software can be removed before the abort, leaving the installation inoperable.
Please consider moving the to-be-replaced version into a "\old version_nnnn" directory so if something goes wrong it's easy to put things right (and if this is already being done, where did you hide it?).
Whether the "\old version_nnnn" directory is deleted at the very end of the install process or left as-is (to be emptied before filling it up again next time) is your call, I'm ok either way.
### #2James Ross
• Open Rails Developer
• Group: Elite Member
• Posts: 4,782
• Joined: 30-June 10
• Gender:Not Telling
• Simulator:Open Rails
• Country:
Posted 26 May 2017 - 02:16 PM
Genma Saotome, on 25 May 2017 - 05:11 PM, said:
On occasion the updater aborts -- your problem, my problem, who knows whose problem, doesn't really matter. What does mater is the previous (working) version of the OR software can be removed before the abort, leaving the installation inoperable.
Please consider moving the to-be-replaced version into a "\old version_nnnn" directory so if something goes wrong it's easy to put things right (and if this is already being done, where did you hide it?).
Whether the "\old version_nnnn" directory is deleted at the very end of the install process or left as-is (to be emptied before filling it up again next time) is your call, I'm ok either way.
The updater performs these steps when applying an update (it does none of this when simply checking for updates):
• Check that \UpdateTest directory can be created and deleted
• Delete \UpdateStage and \UpdateDirty if they exist from any previous updates
• Verify that the update in \UpdateStage is valid
• Move all files from \ to \UpdateDirty
• Move all files from \UpdateStage to \
• Even if an error occurs earlier: Delete \UpdateStage and \UpdateDirty
So the issue is that, no matter what, it always tries to clean up at the end. This is easy enough to change, and honestly I am not really sure why it was written to do that, even though it was likely me that wrote that bit.
In X3862 I have made two changes:
• The updater only deletes \UpdateStage and \UpdateDirty on a successful update
• The copying of files from \ to \UpdateDirty and \UpdateStage to \ have been split into separate functions purely so errors/stack traces will indicate which copy operation failed
Page 1 of 1 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9132811427116394, "perplexity": 6052.072005974678}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818690268.19/warc/CC-MAIN-20170925002843-20170925022843-00678.warc.gz"} |
https://solvedlib.com/i-need-help-with-my-physics-ii-non-calculus,60405 | # I need help with my Physics II (Non-Calculus) homework. How do I solve for each and...
###### Question:
I need help with my Physics II (Non-Calculus) homework. How do I solve for each and what would the answers be? Thank you!
0.5 Problems Due January 28, 2019 In order to obtain good marks you solutions must include the following: 1. Identify yourself in order to obtain credit, that is put your name in the upper left hand corner of the page 2. Write legibly - If I have to spend time trying to figure out what you are trying to say it will put me in a contrary mood, which you do not desire 3. Write a statement of the problem. Your statement need not be verbatimm, but it should convey the same meaning Indicate your method of solution and clearly indicate your answers 1. The solution for a SHO (simple harmonic oscillator) is given as: x(t) - 0.1 sin(3t-π/6) meters. Include appropriate units in your answers. (a) What is the amplitude of oscillation? (b) What is the initial position of the oscillator? c) What is the maximum velocity of the oscillator and at what value of r does it occur? (d) What is the maximum acceleration of the oscillator and where does it occur? (e) What are the period and frequency of the oscillator?
(f) If the mass of the oscillator is 0.025 kg what is the oscillator's total energy?
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Use the References to access important values needed for this question According to the ideal gas law, a 10.03 mol sample of nitrogen gas in a 0.8236 L container at 498.7 K should exert a pressure of 498.4 atm. What is the percent difference between the pressure calculated using the van der Waals&x...
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Question 3, Complete thc table below For the chzir structures, assune that tbe equatorial position methylol group (-CHOH) i5 [E [he &-D Gulse a-D Gulac Glucoside ofa-D Guloze with (structure on previons page): Chair Structure Hauorth Structure CH;OHH+: Chair Structue Question 4 D-Allose and D-Al...
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certain Catalied Feaction Lnonn 7aje ectivation be 2.7 x 1O MIs, Use this energt 642M1.0 UJitnol information Furthetmores ansner the qucstions URe rate 0" thvus reaction the tablc beio N, ennatuned 4JSS K end found Supbot' Kept [he concentrationt EMa Yef el reactants Henetatune 10%& ...
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##### 4 1 Glz 1 | 1 1 L 1 9 1 L 1 3 j : 1 E 1 [ 1 14 l elI | 1 1 | L ] 2 1 1 8 1 1 iil 9 1 1 M
4 1 Glz 1 | 1 1 L 1 9 1 L 1 3 j : 1 E 1 [ 1 1 4 #l elI | 1 1 | L ] 2 1 1 8 1 1 iil 9 1 1 M... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7916162014007568, "perplexity": 5101.0019945040185}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296949642.35/warc/CC-MAIN-20230331113819-20230331143819-00613.warc.gz"} |
http://mathhelpforum.com/differential-geometry/137420-norm-indicator-function-l-2-space.html | # Thread: Norm of indicator function in L^2-space
1. ## Norm of indicator function in L^2-space
I am reading a book by one John Conway, and at one point he seems to imply that $\|\chi_{\Delta}\|_2 = \left(\int |\chi_{\Delta}|^2 d \mu\right)^{1/2} = (\mu({\Delta}))^{1/2}$ (where $\chi_{\Delta}$ is the indicator function).
I can't quite understand this. I feel it should just be $\mu({\Delta})$...
So, does anyone know why?
2. Because ${\chi_\Delta}^2=\chi_{\Delta\bigcap\Delta}=\chi_\D elta, and \int \chi_\Delta d\mu=\mu(\Delta)$
3. Originally Posted by karkusha
Because ${\chi_\Delta}^2=\chi_{\Delta\bigcap\Delta}=\chi_\D elta$
Yes, of course! Thanks!
4. Originally Posted by karkusha
Because ${\chi_\Delta}^2=\chi_{\Delta\bigcap\Delta}=\chi_\D elta, and \int \chi_\Delta d\mu=\mu(\Delta)$
Wait a tick - the square is outside the absolute value, not inside...
5. $|\chi_\Delta|^2=|{\chi_\Delta}^2|=|\chi_\Delta|=\c hi_\Delta$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 7, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9270772933959961, "perplexity": 1288.8029071879866}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368705953421/warc/CC-MAIN-20130516120553-00037-ip-10-60-113-184.ec2.internal.warc.gz"} |
https://learncybers.com/determinant-calculator/ | Home How to Matrix Determinant Calculator – 2 x 2, 3 x 3, 4 x 4
# Matrix Determinant Calculator – 2 x 2, 3 x 3, 4 x 4
Determinant calculator can be automatic or manual. In automatic calculators, you may put values and get answer, but you will not be able to learn. Therefore, in this procedure, we will teach you manual determinant calculator method to understand step by step.
Determinant is considered an algebraic representation of the sum of the products of elements each with an algebraic symbol, typically in a square array and used for the solution of systems of linear equations.
The determinant for linear algebra is a scalar value that can be determined by square matrix elements and which encodes those linear transformation properties defined in a matrix. The determinant of a matrix A is denoted det(A), det A, or |A|.
The volume scaling factor defined in the matrix can be considered geometrically as the linear transformation. This is also the signed n-dimensional volume occupied by the matrix ‘ column or row vectors. The determinant is either positive or negative based on the preservation or reversal of n-space orientation through the linear mapping.
In the case of a 2 × 2 matrix the determinant calculator may be defined as:
In the cast of 3×3 matrix, the determinant calculator may be defined as:
Now, it is time to go through the types of determinant matrixes.
## 2×2 Matrices:
### What is a 2×2 matrix?
A matrix that contains two rows and two columns is known as 2x2matrix. A 2X2 matrix is a tool used to help gain insight and outcomes in a dialogue. On each end of the spectrum designers create a matrix of 2×2 with opposite features (i.e. cheap versus costly).
### Why to use a 2×2 matrix?
A 2×2 matrix is a tool that allows people to think and talk about issues. Use it to help you learn about connections between things or people during your synthesis process. It is expected that a 2×2 will provide input. 2×2 matrices are perfect for expressing a reference you want to communicate visually.
You may be interested in reading more articles on Learn Cybers.
### How to use a 2×2 matrix?
For a 2×2 matrix (2 rows and 2 columns):
The determinant is:
“The determinant of A equals a times d minus b times c”
If the input in the matrix is real, Matrix A can be used in two linear maps: One, which maps the regular base vectors to A rows, and the other, which maps them to A columns- A. In other words, you subtract the top-to-bottom-right diagonal to take the determinants of a 2-2 matrix, from which you extract the product from the bottom-left-to-top-right diagonal.
It is easy to remember when you think of a cross:
• Red is negative (−bc)
Example-1
Find determinant of the following matrix ‘B’:
|B|= 4×8 − 6×3
= 32−18
= 14
### Inverse of a 2×2 matrix:
So, how to calculate the inverse of a 2×2 matrix?
It’s very easy. For a 2×2 matrix:
In other words; switch the positions of a and d, put negatives on b and c, and split all by evaluating (ad-bc). Just for example:
Example-2:
it must be true that: A × A-1 = I
You may be interested in reading more articles on Learn Cybers.
### Multiplication of a 2×2 matices:
That row of the first matrix is taken and every column of the second matrix is multiplied. Together, that contributes. And after that, find the determinant of that resulted matrix.
## 3×3 Matrix:
A matrix that contains three rows and three columns is known as 3×3 matrix.
### How to find/solve a 3×3 matrix?
The traditional method for calculating a matrix of 3×3 is a breakdown of smaller, easy-to-manage, evaluating problems of 2×2.
For Example-1:
For a 3×3 matrix:
### Inverse of a 3×3 matrix:
Here, we have used Elementary Row operation for finding the inverse of a 3×3 matrix.
We begin with matrix A and write it down next to it with an identity matrix I:
(This is called the “Augmented Matrix”)
Here, ’I’ is known as Identity Matrix.
### Identity Matrix:
The “Identity Matrix” is the matrix equivalent of the number “1”:
A 3×3 Identity Matrix
• It is “square” (has same number of rows as columns),
• It has 1s on the diagonal and 0s everywhere else.
• It’s symbol is the capital letter I
But in Elementary Row Operation, we can only do,
• swap rows
• multiply or divide each element in a a row by a constant
• replace a row by adding or subtracting a multiple of another row to it
We do these steps as follows:
No.2- Add row 2 to row 1,
No.3- then divide row 1 by 5,
No.4- Then take 2 times the first row, and subtract it from the second row,
No.5- Multiply the second row by -1/2,
No.6- Now swap the second and third row,
No.7- Last, subtract the third row from the second row,
And we are done!
And matrix A has been made into an Identity Matrix and at the same time an Identity Matrix got made into A-1.
### Multiplication of 3×3 matrix:
The following example explains the multiplication of two 3×3 matixes.
Example-1:
Then find the determinant of the resulted matrix ‘C’, by using the method that is explained earlier.
## 4×4 Matrix:
A matrix having four rows and four columns is known as 4×4 matrix. E.g:this is a 4×4 matrix.
### The inverse of a 4×4 matrix:
The following is the easiest formula that shows the way of finding the inverse of a 4×4 matrix;
Using this formula, you can easily find the determinant of a 4×4 matrix by applying the determinant formula to the resulted matrix.
You may be interested in reading more articles on Learn Cybers.
### Applications of determinants:
Following are the applications of a determinant:
• Linear Independence
• The orientation of a basis
• Volume and Jacobean Determinant
• Vandermonde Determinant
• Circulants
0 comment | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8729444146156311, "perplexity": 796.8586431717209}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347407001.36/warc/CC-MAIN-20200530005804-20200530035804-00423.warc.gz"} |
https://crypto.stackexchange.com/questions/42804/why-do-the-signature-and-ciphertext-size-increase-in-post-quantum-schemes | # Why do the signature and ciphertext size increase in post-quantum schemes?
Why do the signature and ciphertext size increase in post-quantum schemes? And is there any table or comparison as to how much this increase happens for each scheme type (lattice, multivariate, code-based, etc.)
• I'm really not sure at all about what I'm going to say, but I've heard about the so-called Grover's quantum algorithm, which can improve the efficiency of classical algorithms, and therefore improve classical attacks. This is a good forum to read about it: pqcrypto.org/pqc-forum/20161028-152555.txt – Daniel Jan 5 '17 at 21:41
• Increase compared to what? The message? Asymmetric schemes? I guess the best we can do is list signature and ciphertext sizes for specific strengths and a minimum amount of message size, say 256 bits for encryption and 512 bits for signature generation (enough for most hybrid systems). – Maarten Bodewes Jan 5 '17 at 22:40
• @SolidSnake That's why we can just increase the key size for symmetric cryptosystems. But, for public key crypto, Shor's algorithm breaks them in polynomial time, so people design new alternatives, but they usually have large signature size. – typos Jan 5 '17 at 23:20
• I know about that, what I do not know (like Maarten) is what are you comparing the sizes with? MPKC cryptosystems do not have that large ciphertext sizes in general – Daniel Jan 5 '17 at 23:27
If quantum computers are built, then the discrete log and factoring problems will be broken. This means that all schemes based on factoring (e.g., RSA) or discrete log (e.g., ECIES, ECDSA) are broken. In addition, due to Grover's algorithm it is possible to find a symmetric key in time that is square root of the key space. Thus, for $2^{128}$ security, you need 256-bit keys. This means that we need to upgrade to AES-256. Finally, using a trick with Grover's algorithm, it is possible to find collisions in a hash function in time $O(2^{n/3})$ where $n$ is the length of the output. Thus, we need an output of 384 bits at the minimum.
As a result of the above, we are still able to do symmetric crypto and collision resistant hash functions (to the best of our knowledge), but our asymmetric crypto breaks. The factoring and discrete log based systems must therefore be replaced. Currently, the candidates that exist are mainly based on lattices and coding (but there are some others as well). All of these require larger keys and larger ciphertexts, irrespective of quantum computers, simply by the nature of the problems. For signatures there are also schemes based on hash functions, but these also have long signatures. We don't have any proof that these need to be much longer, and it's not because we are just taking longer keys; rather, it's due to the techniques that we currently have for constructing asymmetric schemes that are post-quantum secure.
• “it is possible to find collisions in a hash function in time $$O(n^{1/3})$$, where is the length of the output” – are you sure it is possible in sublinear time? If it is, I wonder how… But I believe there is a mistake. – v6ak Jan 7 '17 at 6:56
• Sorry, I meant where $n$ is the size of the output space. So, for length $n$ output, it is time $2^{n/3}$. Thanks. – Yehuda Lindell Jan 7 '17 at 23:11
• – SEJPM Jan 8 '17 at 10:15
What you say isn't entirely correct. In some post-quantum schemes, the signature or ciphertext is actually smaller than the equivalent-but-classical security level analogue in ECC. See for example the MQ encryption scheme ZHFE (link) or the code-based signature scheme CFS (link). However, in these cases the public key is invariably huge. In other cases we have the opposite: e.g. in the hash-based signature scheme SPHINCS (link), the public key is nice and small, but the signatures are huge. Lattice-based schemes tend to produce public keys of roughly the same size as the ciphertext or signature, but both are noticeably larger than their ECC counterparts. So there is a question there, but it should be rephrased to something like "why is $|\mathsf{pk}| + |\mathsf{s}|$ or $|\mathsf{pk}| + |\mathsf{c}|$ always so large in post-quantum crypto, but not in classical crypto?"
The way all public key schemes work is by relying on hard computational problems with a very definite algebraic structure.* This structure is necessary to guarantee a link between the public and private keys, i.e., only the holder of the private key that matches the public key should be able to decrypt or sign messages. This stands in stark contrast to symmetric crypto, where security relies on breaking -not retaining- algebraic structure and no such link is necessary because there is no distinction between public and private keys. Public key schemes are the subject to more functional constraints than symmetric schemes and as a result there are fewer strategies for their construction. Of those strategies we know to work, only schemes based on number theory and elliptic curves are known to be broken by Shor's quantum algorithm. The others are consequently considered part of post-quantum cryptography. So maybe the best phrasing of your question is something like "why are schemes that are broken by Shor's algorithm, also the schemes with the smallest $|\mathsf{pk}| + |\mathsf{c}|$ and $|\mathsf{pk}| + |\mathsf{s}|$?"
This question has a straightforward answer: both number theory and elliptic curves, or commutative group theory in general, enable a very succinct encoding of computational hardness while retaining a lot of algebraic structure. Unfortunately, this copious algebraic structure comes back to bite you in the ass because it is precisely what allows Shor's algorithm to work.
The good news is that, like Yehuda says, there is no proof that hard algebraic problems that resist attacks on quantum computers cannot have a succinct encoding. So conceivably, it may be possible to design short public key and short signature/ciphertext post-quantum schemes. We just don't know of any that accomplish this.
In terms of a comparison of existing schemes, take a look at eBATS (link), a website that compares operational cost as well as key and message size of various pre- and post-quantum schemes.
*: The exception to this rule is the branch of hash-based signatures. But their notable lack of algebraic structure is also what causes the inherent statefulness (i.e. you have to keep track of all previous signatures to be secure) and what kills the possibility for public key encryption based on hash functions.
• "The exception to this rule is the branch of hash-based signatures. But their notable lack of algebraic structure is also what causes the inherent statefulness" The SPHINCS is stateless. – Calmarius Oct 27 '19 at 19:12 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4918343126773834, "perplexity": 746.7110663403623}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243988796.88/warc/CC-MAIN-20210507150814-20210507180814-00230.warc.gz"} |
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colliding beams [p p] (33) 33
scattering [p p] (32) 32
b physics (28) 28
cp: violation (27) 27
physics, multidisciplinary (27) 27
decay (25) 25
mass spectrum: (24) 24
tool (22) 22
muon: pair production (21) 21
asymmetry: cp (20) 20
cp violation (20) 20
flavor physics (20) 20
astrophysics (19) 19
particles and fields (19) 19
13000 gev-cms (16) 16
7000 gev-cms8000 gev-cms13000 gev-cms (16) 16
physics of elementary particles and fields (16) 16
branching ratio: ratio: measured (15) 15
elementary particles and fields (15) 15
elementary particles, quantum field theory (15) 15
quantum field theories, string theory (15) 15
rapidity dependence (15) 15
experiments (14) 14
nuclear and particle physics. atomic energy. radioactivity (14) 14
astronomy & astrophysics (13) 13
branching fraction (13) 13
física de partícules (13) 13
lhcb - abteilung hofmann (13) 13
luminosity (13) 13
science & technology (12) 12
transverse momentum dependence (12) 12
bottom mesons (11) 11
violation [cp] (11) 11
classical and quantum gravitation, relativity theory (10) 10
high energy astrophysical phenomena (10) 10
humans (10) 10
mesons (10) 10
physical sciences (10) 10
quantum physics (10) 10
rare decay (10) 10
structure (10) 10
charm physics (9) 9
collisions (9) 9
cp [asymmetry] (9) 9
cross sections (9) 9
d0 anti-d0: mixing (9) 9
differential cross section: measured (9) 9
j/psi: leptonic decay (9) 9
dimuon: mass spectrum (8) 8
female (8) 8
hadronic decays of bottom mesons (8) 8
male (8) 8
nuclear & particles physics (8) 8
pair production [muon] (8) 8
14.40.nd (7) 7
[mass spectrum] (7) 7
channel cross section: measured (7) 7
charm (7) 7
flavour changing neutral currents (7) 7
forward physics (7) 7
heavy quark production (7) 7
k: pair production (7) 7
kinematics (7) 7
nuclear theory (7) 7
settore fis/04 - fisica nucleare e subnucleare (7) 7
13.25.hw (6) 6
530 physics (6) 6
8000 gev-cms (6) 6
aged (6) 6
charge conjugation parity time reversal and other discrete symmetries (6) 6
ckm angle gamma (6) 6
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by Aaij, R and Adeva, B and Adinol, M and Affolder, A and Ajaltouni, Z and Akar, S and Albrecht, J and Alessio, F and Alexander, M and Ali, S and Alkhazov, G and Alvarez Cartelle, P and Alves, A. A and Amato, S and Amerio, S and Amhis, Y and An, L and Anderlini, L and Anderson, J and Aneassen, R and Aneotti, M and Anews, J. E and Appleby, R. B and Gutierrez, O. Aquines and Archilli, F and Artamonov, A and Artuso, M and Aslanides, E and Auriemma, G and Baalouch, M and Bachmann, S and Back, J. J and Badalov, A and Baesso, C and Baldini, W and Barlow, R. J and Barschel, C and Barsuk, S and Barter, W and Batozskaya, V and Battista, V and Bay, A and Beaucourt, L and Beddow, J and Bedeschi, F and Bediaga, I and Belogurov, S and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Benton, J and Berezhnoy, A and Bernet, R and Bettler, M. -O and van Beuzekom, M and Bien, A and Bifani, S and Bird, T and Bizzeti, A and Bjornstad, P. M and Blake, T and Blanc, F and Blouw, J and Blusk, S and Bocci, V and Bondar, A and Bondar, N and Bonivento, W and Borghi, S and Borgia, A and Borsato, M and Bowcock, T. J. V and Bowen, E and Bozzi, C and Brambach, T and Bressieux, J and Brett, D and Britsch, M and Britton, T and Brodzicka, J and Brook, N. H and Brown, H and Bursche, A and Buytaert, J and Cadeddu, S and Calabrese, R and Calvi, M and Calvo Gomez, M and Campana, P and Perez, D. Campora and Carbone, A and Carboni, G and Cardinale, R and Cardini, A and Carson, L and Akiba, K. Carvalho and Casse, G and Cassina, L and ... and LHCb Collaboration and The LHCb Collaboration
International Journal of Modern Physics A, ISSN 0217-751X, 03/2015, Volume 30, Issue 7, p. 1530022
Journal Article
Physical Review Letters, ISSN 0031-9007, 09/2017, Volume 119, Issue 11
A highly significant structure is observed in the Lambda K-+(c)-pi(+)pi(+) mass spectrum, where the Lambda(+)(c) baryon is reconstructed in the decay mode...
MONTE-CARLO | GENERATOR | MASSES | B-C MESONS | DECAY | SPECTROSCOPY | PHYSICS, MULTIDISCIPLINARY | HADRONIC PRODUCTION | VERSION | HEAVY BARYONS | GENXICC | Physics - High Energy Physics - Experiment
Journal Article
by CMS, The and Collaborations, LHCb and : and Khachatryan, V and Sirunyan, A. M and Tumasyan, A and Adam, W and Bergauer, T and Dragicevic, M and Erö, J and Friedl, M and Frühwirth, R and Ghete, V. M and Hartl, C and Hörmann, N and Hrubec, J and Jeitler, M and Kiesenhofer, W and Knünz, V and Krammer, M and Krätschmer, I and Liko, D and Mikulec, I and Rabady, D and Rahbaran, B and Rohringer, H and Schöfbeck, R and Strauss, J and Treberer-Treberspurg, W and Waltenberger, W and Wulz, C. -E and Mossolov, V and Shumeiko, N and Gonzalez, J. Suarez and Alderweireldt, S and Bansal, S and Cornelis, T and De Wolf, E. A and Janssen, X and Knutsson, A and Lauwers, J and Luyckx, S and Ochesanu, S and Rougny, R and Van De Klundert, M and Van Haevermaet, H and Van Mechelen, P and Van Remortel, N and Van Spilbeeck, A and Blekman, F and Blyweert, S and D'Hondt, J and Daci, N and Heracleous, N and Keaveney, J and Lowette, S and Maes, M and Olbrechts, A and Python, Q and Strom, D and Tavernier, S and Van Doninck, W and Van Mulders, P and Van Onsem, G. P and Villella, I and Caillol, C and Clerbaux, B and De Lentdecker, G and Dobur, D and Favart, L and Gay, A. P. R and Grebenyuk, A and Léonard, A and Mohammadi, A and Perniè, L and Randle-conde, A and Reis, T and Seva, T and Thomas, L and Velde, C. Vander and Vanlaer, P and Wang, J and Zenoni, F and Adler, V and Beernaert, K and Benucci, L and Cimmino, A and Costantini, S and Crucy, S and Dildick, S and Fagot, A and Garcia, G and Mccartin, J and Rios, A. A. Ocampo and Ryckbosch, D and Diblen, S. Salva and Sigamani, M and Strobbe, N and Thyssen, F and Tytgat, M and ... and Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Nature (London), ISSN 0028-0836, 11/2014, Volume 522, Issue 7554
Nature 522, 68-72 (04 June 2015) A joint measurement is presented of the branching fractions $B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ in proton-proton...
experimental particle physics | PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Journal Article
by Aaij, R and Adeva, B and Adinolfi, M and Affolder, A and Ajaltouni, Z and Albrecht, J and Alessio, F and Alexander, M and Ali, S and Alkhazov, G and Alvarez Cartelle, P and Alves, A. A and Amato, S and Amerio, S and Amhis, Y and An, L and Anderlini, L and Anderson, J and Aneassen, R and Aneotti, M and Anews, J. E and Appleby, R. B and Gutierrez, O. Aquines and Archilli, F and Artamonov, A and Artuso, M and Aslanides, E and Auriemma, G and Baalouch, M and Bachmann, S and Back, J. J and Badalov, A and Balagura, V and Baldini, W and Barlow, R. J and Barschel, C and Barsuk, S and Barter, W and Batozskaya, V and Bauer, Th and Bay, A and Beaucourt, L and Beddow, J and Bedeschi, F and Bediaga, I and Belogurov, S and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Benton, J and Berezhnoy, A and Bernet, R and Bettler, M. -O and van Beuzekom, M and Bifani, S and Bird, T and Bizzeti, A and Bjornstad, P. M and Blake, T and Blanc, F and Blouw, J and Blusk, S and Bocci, V and Bondar, A and Bondar, N and Bonivento, W and Borghi, S and Borgia, A and Borsato, M and Bowcock, T. J. V and Bowen, E and Bozzi, C and Brambach, T and van den Brand, J and Bressieux, J and Brett, D and Britsch, M and Britton, T and Brodzicka, J and Brook, N. H and Brown, H and Bursche, A and Busetto, G and Buytaert, J and Cadeddu, S and Calabrese, R and Calvi, M and Calvo Gomez, M and Camboni, A and Campana, P and Campora Perez, D and Carbone, A and Carboni, G and Cardinale, R and Cardini, A and Carranza-Mejia, H and Carson, L and Akiba, K. Carvalho and ... and LHCb Collaboration
Physical Review Letters, ISSN 0031-9007, 06/2014, Volume 112, Issue 22, p. 222002
Resonant structures in B-0 -> psi'pi K--(+) decays are analyzed by performing a four-dimensional fit of the decay amplitude, using pp collision data...
PHYSICS, MULTIDISCIPLINARY | MESONS | Physics - High Energy Physics - Experiment | Physics | High Energy Physics - Experiment
Journal Article
by Aaij, R and Adeva, B and Adinolfi, M and Affolder, A and Ajaltouni, Z and Albrecht, J and Alessio, F and Alexander, M and Ali, S and Alkhazov, G and Alvarez Cartelle, P and Alves, A. A and Amato, S and Amerio, S and Amhis, Y and An, L and Anderlini, L and Anderson, J and Aneassen, R and Aneotti, M and Anews, J. E and Appleby, R. B and Gutierrez, O. Aquines and Archilli, F and Artamonov, A and Artuso, M and Aslanides, E and Auriemma, G and Baalouch, M and Bachmann, S and Back, J. J and Badalov, A and Balagura, V and Baldini, W and Barlow, R. J and Barschel, C and Barsuk, S and Barter, W and Batozskaya, V and Bauer, Th and Bay, A and Beddow, J and Bedeschi, F and Bediaga, I and Belogurov, S and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Benton, J and Berezhnoy, A and Bernet, R and Bettler, M. -O and van Beuzekom, M and Bien, A and Bifani, S and Bird, T and Bizzeti, A and Bjornstad, P. M and Blake, T and Blanc, F and Blouw, J and Blusk, S and Bocci, V and Bondar, A and Bondar, N and Bonivento, W and Borghi, S and Borgia, A and Borsato, M and Bowcock, T. J. V and Bowen, E and Bozzi, C and Brambach, T and van den Brand, J and Bressieux, J and Brett, D and Britsch, M and Britton, T and Brook, N. H and Brown, H and Bursche, A and Busetto, G and Buytaert, J and Cadeddu, S and Calabrese, R and Callot, O and Calvi, M and Calvo Gomez, M and Camboni, A and Campana, P and Perez, D. Campora and Carbone, A and Carboni, G and Cardinale, R and Cardini, A and Carranza-Mejia, H and Carson, L and Carvalho Akiba, K and ... and LHCb Collaboration
Journal of High Energy Physics, ISSN 1029-8479, 06/2014, Volume 6, Issue 6, p. 133
Journal Article
by Aaij, R and Adeva, B and Adinolfi, M and Ajaltouni, Z and Akar, S and Albrecht, J and Alessio, F and Alexander, M and Alfonso Albero, A and Ali, S and Alkhazov, G and Alvarez Cartelle, P and Alves, A.A and Amato, S and Amerio, S and Amhis, Y and An, L and Anderlini, L and Andreassi, G and Andreotti, M and Andrews, J.E and Appleby, R.B and Archilli, F and D'Argent, P and Arnau Romeu, J and Artamonov, A and Artuso, M and Aslanides, E and Atzeni, M and Auriemma, G and Baalouch, M and Babuschkin, I and Bachmann, S and Back, J.J and Badalov, A and Baesso, C and Baker, S and Balagura, V and Baldini, W and Baranov, A and Barlow, R.J and Barschel, C and Barsuk, S and Barter, W and Baryshnikov, F and Batozskaya, V and Battista, V and Bay, A and Beaucourt, L and Beddow, J and Bedeschi, F and Bediaga, I and Beiter, A and Bel, L.J and Beliy, N and Bellee, V and Belloli, N and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Beranek, S and Berezhnoy, A and Bernet, R and Berninghoff, D and Bertholet, E and Bertolin, A and Betancourt, C and Betti, F and Bettler, M.-O and Van Beuzekom, M and Bezshyiko, Ia and Bifani, S and Billoir, P and Birnkraut, A and Bizzeti, A and Bjørn, M and Blake, T and Blanc, F and Blusk, S and Bocci, V and Boettcher, T and Bondar, A and Bondar, N and Bordyuzhin, I and Borghi, S and Borisyak, M and Borsato, M and Bossu, F and Boubdir, M and Bowcock, T.J.V and Bowen, E and Bozzi, C and Braun, S and Britton, T and Brodzicka, J and Brundu, D and Buchanan, E and Burr, C and ... and LHCb Collaboration and Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Physical Review Letters, ISSN 0031-9007, 02/2018, Volume 120, Issue 6
Searches are performed for both promptlike and long-lived dark photons, A', produced in proton-proton collisions at a center-of-mass energy of 13 TeV, using A'...
PHI-MESON DECAYS | KLOE DETECTOR | PARTICLES | PHYSICS, MULTIDISCIPLINARY | VECTOR GAUGE BOSON | HEAVY NEUTRINOS | EXCLUSION LIMITS | ELECTRON-BEAM-DUMP | MASS RANGE | FORCES | Physics - High Energy Physics - Experiment | Física de partícules | Experiments | Particle physics | PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Journal Article
by Aaij, R and Adeva, B and Adinolfi, M and Ajaltouni, Z and Akar, S and Albrecht, J and Alessio, F and Alexander, M and Albero, AA and Ali, S and Alkhazov, G and Cartelle, PA and Alves, AA and Amato, S and Amerio, S and Amhis, Y and An, L and Anderlini, L and Andreassi, G and Andreotti, M and Andrews, JE and Appleby, RB and Archilli, F and d'Argent, P and Romeu, JA and Artamonov, A and Artuso, M and Aslanides, E and Auriemma, G and Baalouch, M and Babuschkin, I and Bachmann, S and Back, JJ and Badalov, A and Baesso, C and Baker, S and Balagura, V and Baldini, W and Baranov, A and Barlow, RJ and Barschel, C and Barsuk, S and Barter, W and Baryshnikov, F and Batozskaya, V and Battista, V and Bay, A and Beaucourt, L and Beddow, J and Bedeschi, F and Bediaga, I and Beiter, A and Bel, LJ and Beliy, N and Bellee, V and Belloli, N and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Beranek, S and Berezhnoy, A and Bernet, R and Berninghoff, D and Bertholet, E and Bertolin, A and Betancourt, C and Betti, F and Bettler, MO and van Beuzekom, M and Bezshyiko, I and Bifani, S and Billoir, P and Birnkraut, A and Bitadze, A and Bizzeti, A and Bjorn, M and Blake, T and Blanc, F and Blouw, J and Blusk, S and Bocci, V and Boettcher, T and Bondar, A and Bondar, N and Bonivento, W and Bordyuzhin, I and Borgheresi, A and Borghi, S and Borisyak, M and Borsato, M and Bossu, F and Boubdir, M and Bowcock, TJV and Bowen, E and Bozzi, C and Braun, S and Britton, T and Brodzicka, J and ... and LHCB Collaboration
PHYSICAL REVIEW D, ISSN 2470-0010, 04/2018, Volume 97, Issue 7
The ratio of branching fractions R(D*(-)) = B(B-0 -> D*(-) tau(+)nu(tau))/(B-0 -> D*(-) mu(+)nu(mu)) is measured using a data sample of proton-proton...
LEPTOQUARKS | ENERGY | SIMULATION | ASTRONOMY & ASTROPHYSICS | PHYSICS, PARTICLES & FIELDS | Physics - High Energy Physics - Experiment
Journal Article
by Aaij, R and Adeva, B and Adinolfi, M and Ajaltouni, Z and Akar, S and Albrecht, J and Alessio, F and Alexander, M and Ali, S and Alkhazov, G and Cartelle, P. Alvarez and Alves, A. A and Amato, S and Amerio, S and Amhis, Y and An, L and Anderlini, L and Aneassi, G and Aneotti, M and Anews, J. E and Appleby, R. B and Gutierrez, O. Aquines and Archilli, F and d'Argent, P and Romeu, J. Arnau and Artamonov, A and Artuso, M and Aslanides, E and Auriemma, G and Baalouch, M and Babuschkin, I and Bachmann, S and Back, J. J and Badalov, A and Baesso, C and Baldini, W and Barlow, R. J and Barschel, C and Barsuk, S and Barter, W and Batozskaya, V and Batsukh, B and Battista, V and Beaucourt, L and Beddow, J and Bedeschi, F and Bediaga, I and Bel, L. J and Bellee, V and Belloli, N and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Benton, J and Berezhnoy, A and Bernet, R and Bertolin, A and Betti, F and Bettler, M. -O and Van Beuzekom, M and Bezshyiko, I and Bifani, S and Billoir, P and Bird, T and Birnkraut, A and Bitadze, A and Bizzeti, A and Blake, T and Blanc, F and Blouw, J and Blusk, S and Bocci, V and Boettcher, T and Bondar, A and Bondar, N and Bonivento, W and Borgheresi, A and Borghi, S and Borisyak, M and Borsato, M and Bossu, F and Boubdir, M and Bowcock, T. J. V and Bowen, E and Bozzi, C and Braun, S and Britsch, M and Britton, T and Brodzicka, J and Buchanan, E and Burr, C and Bursche, A and Buytaert, J and Cadeddu, S and Calabrese, R and Calvi, M and Calvo Gomez, M and Campana, P and ... and LHCb Collaboration
Physical Review Letters, ISSN 0031-9007, 01/2017, Volume 118, Issue 2
The first full amplitude analysis of B+ -> J/psi phi K+ with J/psi -> mu(+)mu(-), phi -> K+K- decays is performed with a data sample of 3 fb(-1) of pp...
PARTICLES | PHYSICS, MULTIDISCIPLINARY | Physics - High Energy Physics - Experiment
Journal Article
by Aaij, R and Adeva, B and Adinolfi, M and Affolder, A and Ajaltouni, Z and Albrecht, J and Alessio, F and Alexander, M and Ali, S and Alkhazov, G and Alvarez Cartelle, P and Alves, A. A and Amato, S and Amerio, S and Amhis, Y and Anderlini, L and Anderson, J and Aneassen, R and Aneotti, M and Anews, J. E and Appleby, R. B and Gutierrez, O. Aquines and Archilli, F and Artamonov, A and Artuso, M and Aslanides, E and Auriemma, G and Baalouch, M and Bachmann, S and Back, J. J and Badalov, A and Balagura, V and Baldini, W and Barlow, R. J and Barschel, C and Barsuk, S and Barter, W and Batozskaya, V and Bauer, T and Bay, A and Beddow, J and Bedeschi, F and Bediaga, I and Belogurov, S and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Benton, J and Berezhnoy, A and Bernet, R and Bettler, M. -O and van Beuzekom, M and Bien, A and Bifani, S and Bird, T and Bizzeti, A and Bjornstad, P. M and Blake, T and Blanc, F and Blouw, J and Blusk, S and Bocci, V and Bondar, A and Bondar, N and Bonivento, W and Borghi, S and Borgia, A and Borsato, M and Bowcock, T. J. V and Bowen, E and Bozzi, C and Brambach, T and van den Brand, J and Bressieux, J and Brett, D and Britsch, M and Britton, T and Brook, N. H and Brown, H and Bursche, A and Busetto, G and Buytaert, J and Cadeddu, S and Calabrese, R and Callot, O and Calvi, M and Calvo Gomez, M and Camboni, A and Campana, P and Perez, D. Campora and Carbone, A and Carboni, G and Cardinale, R and Cardini, A and Carranza-Mejia, H and Carson, L and Akiba, K. Carvalho and Casse, G and ... and LHCb Collaboration
Physical Review Letters, ISSN 0031-9007, 04/2014, Volume 112, Issue 13, p. 131802
A search for heavy Majorana neutrinos produced in the B- -> pi(+)mu(-)mu(-) decay mode is performed using 3 fb(-1) of integrated luminosity collected with the...
2 LEPTONS | PHYSICS, MULTIDISCIPLINARY | Physics - High Energy Physics - Experiment | Physics | High Energy Physics - Experiment
Journal Article
by Aaij, R and Adeva, B and Adinolfi, M and Ajaltouni, Z and Akar, S and Albrecht, J and Alessio, F and Alexander, M and Ali, S and Alkhazov, G and Alvarez Cartelle, P and Alves, A. A and Amato, S and Amerio, S and Amhis, Y and Everse, LA and Anderlini, L and Aneassi, G and Aneotti, M and Anews, J.E and Appleby, R. B and Archilli, F and d'Argent, P and Arnau Romeu, J and Artamonov, A and Artuso, M and Aslanides, E and Auriemma, G and Baalouch, M and Babuschkin, I and Bachmann, S and Back, J. J and Badalov, A and Baesso, C and Baker, S.C and Baldini, W and Barlow, R. J and Barschel, C and Barsuk, S and Barter, W and Baszczyk, M and Batozskaya, V and Batsukh, B and Battista, V and Bay, A and Beaucourt, L and Beddow, J and Bedeschi, F and Bediaga, I and Bel, L. J and Bellee, V and Belloli, N and Belous, K and Belyaev, I and Ben-Haim, E and Bencivenni, G and Benson, S and Benton, J and Berezhnoy, A and Bernet, R and Bertolin, A and Betti, F and Bettler, M-O and Van Beuzekom, Martin and Bezshyiko, I and Bifani, S and Billoir, P and Bird, T.D and Birnkraut, A and Bitadze, A and Bizzeti, A and Blake, T and Blanc, F and Blouw, J and Blusk, S and Bocci, V and Boettcher, T and Bondar, A and Bondar, N and Bonivento, W and Borgheresi, A and Borghi, S and Borisyak, M and Borsato, M and Bossu, F and Boubdir, M and Bowcock, T. J. V and Bowen, E and Bozzi, C and Braun, S and Britsch, M and Britton, T and Brodzicka, J and Buchanan, E and Burr, C and Bursche, A and Buytaert, J and Cadeddu, S and Calabrese, R and Calvi, M and ... and LHCb Collaboration and The LHCb collaboration and Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Nature Physics, ISSN 1745-2473, 04/2017, Volume 13, Issue 4, pp. 391 - 396
Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are...
PHYSICS, MULTIDISCIPLINARY | CP-VIOLATION | LAMBDA(B) | Matter & antimatter | Particle physics | Antimatter | Large Hadron Collider | Searching | Decay | Skewed distributions | Standard deviation | Transformations | Baryons | Physics - High Energy Physics - Experiment | Physics | High Energy Physics - Experiment | PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Journal Article
European Physical Journal C, ISSN 1434-6044, 04/2017, Volume 77, Issue 4, pp. 224 - 16
Journal Article
Journal of High Energy Physics, ISSN 1126-6708, 12/2016, Volume 2016, Issue 12, pp. 1 - 59
Journal Article
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