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SciTech Connect: Passivated Tunneling Contacts to N-Type Wafer...
Office of Scientific and Technical Information (OSTI)
Contacts to N-Type Wafer Silicon and Their Implementation into High Performance Solar Cells: Preprint Citation Details In-Document Search Title: Passivated Tunneling...
Tunnelling of relativistic particles from new type black hole in new massive gravity
SciTech Connect (OSTI)
In the framework of the three dimensional New Massive Gravity theory introduced by Bergshoeff, Hohm and Townsend, we analyze the behavior of relativistic spin-1/2 and spin-0 particles in the New-type Black Hole backgroud, solution of the New Massive Gravity.We solve Dirac equation for spin-1/2 and Klein-Gordon equation for spin-0. Using Hamilton-Jacobi method, we discuss tunnelling probability and Hawking temperature of the spin-1/2 and spin-0 particles for the black hole. We observe that the tunnelling probability and Hawking temperature are same for the spin-1/2 and spin-0.
Gecim, Ganim; Sucu, Yusuf, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [Department of Physics, Akdeniz University, Antalya (Turkey)
Tunnel effect and symmetries for Kramers Fokker-Planck type operators
E-Print Network [OSTI]
- values. R´esum´e Nous ´etudions des op´erateurs de type Kramers-Fokker-Planck dans la lim- ite semi are real and exponentially small, and establish the complete semiclassical asymptotics for these eigen ´etablissons leur asymp- totique semi-classique compl`ete. Contents 1 Introduction 3 2 Review of some results
Hérau, Frédéric
Effect of unitary impurities on non-STM types of tunneling in high-T-c superconductors
Based on an extended Hubbard model, we present calculations of both the local (i.e., single-site) and spatially averaged differential tunneling conductance in d-wave superconductors containing nonmagnetic impurities in the unitary limit. Out results...
Zhu, JX; Ting, CS; Hu, Chia-Ren.
Type B Accident Investigation Board Report on the August 5, 1998, Load Haul Dump Accident at U16b Tunnel, Nevada Test Site
Broader source: Energy.gov [DOE]
Thisis theType B Accident Investigation Board report of an industrial accident at the Nevada Test site (NTS), U16b tunnel in which a Bechtel Nevada (BN) employee suffered a compressed skull fracture as a result of being struck onthe head by a valve and fitting assembly on the end of a hose whichhad been broken from a water pipe by a moving piece of construction equipment.
Channel tunnel
ScienceCinema (OSTI)
Jacques Lemley, am�ricain et "chief executif" parle du projet de l'Eurotunnel - tunnel sous la manche
Property:Maximum Wave Length(m) | Open Energy Information
Open Energy Info (EERE)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County,ContAddr2 Jump to:ManagingFieldOffice Jump to:Height(m) Property
Mercury-Mercury Tunneling Junctions. 1. Electron Tunneling Across Symmetric and Asymmetric Alkanethiolate Bilayers
Mercury-Mercury Tunneling Junctions. 1. Electron Tunneling Across Symmetric and Asymmetric by bringing in contact two small (3 �? 10-3 cm2) mercury drop electrodes in a 5-20% (v/v) hexadecane solution incorporating alkanethiolate-type monolayer films. The results reported below convince us that the mercury
Majda, Marcin
The Tunneling Transform
We supplement the Lorentz transform $L(v)$ with a new "Tunneling" transform $T(v)$. Application of this new transform to elementary quantum mechanics offers a novel, intuitive insight into the nature of quantum tunneling; in particular, the so called "Klein Paradox" is discussed.
Robert Hipple
Ultrafast scanning tunneling microscopy
I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.
Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)
Risk analysis for tunneling projects
Tunnel construction is increasing world wide. Although the majority of tunnel construction projects have been completed safely, there have been several incidents that have resulted in delays, cost overruns, and sometimes ...
Sousa. Rita L
Multiple percolation tunneling staircase in metal-semiconductor nanoparticle composites
Multiple percolation transitions are observed in a binary system of RuO{sub 2}-CaCu{sub 3}Ti{sub 4}O{sub 12} metal-semiconductor nanoparticle composites near percolation thresholds. Apart from a classical percolation transition, associated with the appearance of a continuous conductance path through RuO{sub 2} metal oxide nanoparticles, at least two additional tunneling percolation transitions are detected in this composite system. Such behavior is consistent with the recently emerged picture of a quantum conductivity staircase, which predicts several percolation tunneling thresholds in a system with a hierarchy of local tunneling conductance, due to various degrees of proximity of adjacent conducting particles distributed in an insulating matrix. Here, we investigate a different type of percolation tunneling staircase, associated with a more complex conductive and insulating particle microstructure of two types of non-spherical constituents. As tunneling is strongly temperature dependent, we use variable temperature measurements to emphasize the hierarchical nature of consecutive tunneling transitions. The critical exponents corresponding to specific tunneling percolation thresholds are found to be nonuniversal and temperature dependent.
Mukherjee, Rupam; Huang, Zhi-Feng; Nadgorny, Boris [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States)
Ferroelectric tunneling element and memory applications which utilize the tunneling element
DOE Patents [OSTI]
A tunneling element includes a thin film layer of ferroelectric material and a pair of dissimilar electrically-conductive layers disposed on opposite sides of the ferroelectric layer. Because of the dissimilarity in composition or construction between the electrically-conductive layers, the electron transport behavior of the electrically-conductive layers is polarization dependent when the tunneling element is below the Curie temperature of the layer of ferroelectric material. The element can be used as a basis of compact 1R type non-volatile random access memory (RAM). The advantages include extremely simple architecture, ultimate scalability and fast access times generic for all ferroelectric memories.
Kalinin, Sergei V. (Knoxville, TN) [Knoxville, TN; Christen, Hans M. (Knoxville, TN) [Knoxville, TN; Baddorf, Arthur P. (Knoxville, TN) [Knoxville, TN; Meunier, Vincent (Knoxville, TN) [Knoxville, TN; Lee, Ho Nyung (Oak Ridge, TN) [Oak Ridge, TN
Relativistic tunneling and accelerated transmission
We obtain the solutions for the tunneling zone of a one-dimensional electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave equation regime when the incoming wave packet exhibits the possibility of being almost totally transmitted through the potential barrier. The conditions for the occurrence of accelerated and, eventually, superluminal tunneling transmission probabilities are all quantified and the problematic superluminal interpretation originated from the study based on non-relativistic dynamics of tunneling is overcome. The treatment of the problem suggests revealing insights into condensed-matter experiments using electrostatic barriers in single- and bi-layer graphene, for which the accelerated tunneling effect deserves a more careful investigation.
Alex E. Bernardini
Tunneling progress on the Yucca Mountain Project
The current status of tunneling progress on the Yucca Mountain Project (YMP) is presented in this paper. The Exploratory Studies Facility (ESF), a key part of the YMP, has been long in development and construction is ongoing. This is a progress report on the tunneling aspects of the ESF as of January 1, 1996. For purposes of discussion in this summary, the tunneling has progressed in four general phases. The paper describes: tunneling in jointed rock under low stress; tunneling through the Bow Ridge Fault and soft rock; tunneling through the Imbricate Fault Zone; and Tunneling into the candidate repository formation.
Hansmire, W.H. [Parsons Brinckerhoff, Las Vegas, NV (United States); Munzer, R.J. [Kiewit Construction Co., Las Vegas, NV (United States)
Flatback airfoil wind tunnel experiment.
A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.
Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA); Berg, Dale E.
Hybrid Inflation Exit through Tunneling
For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling evolution of the scalar fields and needs to be strongly subdominant for phenomenologically viable models. Tunneling may exclude models with a mass scale below 10^12 GeV, but can be suppressed by small values of the coupling constants. We find that tunneling is negligible for those models, which do not require fine tuning in order to cancel radiative corrections, in particular for GUT-scale SUSY inflation. In contrast, electroweak scale hybrid inflation is not viable, unless the inflaton-waterfall field coupling is smaller than approximately 10^-11.
Bjorn Garbrecht; Thomas Konstandin
Rapid Tunneling and Percolation in the Landscape
Motivated by the possibility of a string landscape, we reexamine tunneling of a scalar field across single/multiple barriers. Recent investigations have suggested modifications to the usual picture of false vacuum decay that lead to efficient and rapid tunneling in the landscape when certain conditions are met. This can be due to stringy effects (e.g. tunneling via the DBI action), or by effects arising due to the presence of multiple vacua (e.g. resonance tunneling). In this paper we discuss both DBI tunneling and resonance tunneling. We provide a QFT treatment of resonance tunneling using the Schr\\"odinger functional approach. We also show how DBI tunneling for supercritical barriers can naturally lead to conditions suitable for resonance tunneling. We argue using basic ideas from percolation theory that tunneling can be rapid in a landscape where a typical vacuum has multiple decay channels and discuss various cosmological implications. This rapidity vacuum decay can happen even if there are no resonance/DBI tunneling enhancements, solely due to the presence of a large number of decay channels. Finally, we consider various ways of circumventing a recent no-go theorem for resonance tunneling in quantum field theory.
Sash Sarangi; Gary Shiu; Benjamin Shlaer
Some investigations on the enhancement of boiling heat transfer from planer surface embedded with continuous open tunnels
Boiling heat transfer from a flat surface can be enhanced if continuous open tunnel type structures are embedded in it. Further, improvement of boiling heat transfer from such surfaces has been tried by two separate avenues. At first, inclined tunnels are embedded over the solid surface and an effort is made to optimize the tunnel inclination for boiling heat transfer. Surfaces are manufactured in house with four different inclinations of the tunnels with or without a reentrant circular pocket at the end of the tunnel. Experiments conducted in the nucleate boiling regime showed that 45 deg inclination of the tunnels for both with and without base geometry provides the highest heat transfer coefficient. Next, active fluid rotation was imposed to enhance the heat transfer from tunnel type surfaces with and without the base geometry. Rotational speed imparted by mechanical stirrer was varied over a wide range. It was observed that fluid rotation enhances the heat transfer coefficient only up to a certain value of stirrer speed. Rotational speed values, beyond this limit, reduce the boiling heat transfer severely. A comparison shows that embedding continuous tunnel turns out to be a better option for the increase of heat transfer coefficient compared to the imposition of fluid rotation. But the behavior of inclined tunnels under the action of fluid rotation is yet to be established and can be treated as a future scope of the work. (author)
Das, A.K.; Das, P.K.; Saha, P. [Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721 302 (India)
Monolithic interconnected module with a tunnel junction for enhanced electrical and optical performance
An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMS), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.
Murray, Christopher S. (Bethel Park, PA); Wilt, David M. (Bay Village, OH)
Heat Transfer in Underground Rail Tunnels
The transfer of heat between the air and surrounding soil in underground tunnels ins investigated, as part of the analysis of environmental conditions in underground rail systems. Using standard turbulent modelling assumptions, flow profiles are obtained in both open tunnels and in the annulus between a tunnel wall and a moving train, from which the heat transfer coefficient between the air and tunnel wall is computed. The radial conduction of heat through the surrounding soil resulting from changes in the temperature of air in the tunnel are determined. An impulse change and an oscillating tunnel air temperature are considered separately. The correlations between fluctuations in heat transfer coefficient and air temperature are found to increase the mean soil temperature. Finally, a model for the coupled evolution of the air and surrounding soil temperature along a tunnel of finite length is given.
Sadokierski, Stefan
Two types of the relation between the intensity and the life time of photoluminescence of core/shell semiconductor quantum dots: Important role of Coulomb field and tunneling transitions
It has been recently found [Gh. Galland, Y. Ghosh, A. Steinbr�ck, M. Sykora, J. A. Hollingsworth, and V. I. Klimov, Nature (London) 479, 203 (2011)] that semiconductor core/shell nanocrystals (NCs) with blinking photoluminescence (PL) can be of �A� or �B� type. NCs of A-type exhibit correlation between the intensity of PL and the life time. In NCs of B-type such correlation is absent. Simple model based on combination of the charging model and the two-level system model is proposed for describing emissive properties of NCs of both types. The model invokes fluctuations of emission ability ?{sub em} of NC to explain the emissive properties of NCs of B-type. Our combined model is also in agreement with anticorrelation between the duration ?{sub off} of off intervals and PL life time t{sub off} in off intervals found recently for NCs of A-type in the experiment [A. A. Cordones, T. J. Bixby, and S. R. Leone, Nano Lett. 11, 3366 (2011)].
Osad'ko, I. S., E-mail: firstname.lastname@example.com [Institute for spectroscopy RAS, Troitsk, 142190 Moscow (Russian Federation)
Competition between cotunneling, Kondo effect, and direct tunneling in discontinuous high-anisotropy magnetic tunnel junctions
The transition between Kondo and Coulomb blockade effects in discontinuous double magnetic tunnel junctions is explored as a function of the size of the CoPt magnetic clusters embedded between AlO[subscript x] tunnel ...
Ciudad, David
Field dynamics and tunneling in a flux landscape
We investigate field dynamics and tunneling between metastable minima in a landscape of Type IIB flux compactifications, utilizing monodromies of the complex structure moduli space to continuously connect flux vacua. After describing the generic features of a flux-induced potential for the complex structure and Type IIB axio-dilaton, we specialize to the Mirror Quintic Calabi--Yau to obtain an example landscape. Studying the cosmological dynamics of the complex structure moduli, we find that the potential generically does not support slow-roll inflation and that in general the landscape separates neatly into basins of attraction of the various minima. We then discuss tunneling, with the inclusion of gravitational effects, in many-dimensional field spaces. A set of constraints on the form of the Euclidean paths through field space are presented, and then applied to construct approximate instantons mediating the transition between de Sitter vacua in the flux landscape. We find that these instantons are generically thick-wall and that the tunneling rate is suppressed in the large-volume limit. We also consider examples where supersymmetry is not broken by fluxes, in which case near-BPS thin-wall bubbles can be constructed. We calculate the bubble wall tension, finding that it scales like a D- or NS-brane bubble, and comment on the implications of this correspondence. Finally, we present a brief discussion of eternal inflation in the flux-landscape.
Matthew C Johnson; Magdalena Larfors
High Tunnels: A First Years Experience Ron Goldy, MSUE and
). This is a report on our experience. Tunnel Construction The tunnel consists of pipe, hardware, wire, plastic in tunnel plants went a foot or more over the stake and had more lateral growth. `Mt. Spring' total fruit
Superconducting Tunnel Junctions as Direct Detectors for Submillimeter Astronomy
Superconducting Tunnel Junctions as Direct Detectors for Submillimeter Astronomy A Dissertation 2008 by John Daniel Teufel. All rights reserved. #12;Abstract Superconducting Tunnel Junctions on the of performance of superconducting tunnel junctions (STJ) as direct detectors for submillimeter radiation. Over
Enhancement of tunnel magnetoresistance in magnetic tunnel junction by a superlattice barrier
Tunnel magnetoresistance of magnetic tunnel junction improved by a superlattice barrier composed of alternate layers of a nonmagnetic metal and an insulator is proposed. The forbidden band of the superlattice is used to predict the low transmission range in the superlattice barrier. By forbidding electron transport in the anti-parallel configuration, the tunnel magnetoresistance is enhanced in the superlattice junction. The results show that the tunnel magnetoresistance ratio for a superlattice magnetic tunnel junction is greater than that for traditional single or double barrier junctions.
Chen, C. H.; Hsueh, W. J., E-mail: firstname.lastname@example.com [Nanomagnetism Group, Department of Engineering Science and Ocean Engineering, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10660, Taiwan (China)
A New Interpretation of the Scanning Tunneling Microscope Image...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
of Graphite. A New Interpretation of the Scanning Tunneling Microscope Image of Graphite. Abstract: In this work, highly-resolved scanning tunneling microscopy images of graphite...
The Tunnel Vision Syndrome: Massively Delaying Progress
The Tunnel Vision Syndrome: Massively Delaying Progress Reiner Hartenstein, Professor, IEEE fellow facet as the complete answer are far from solving the problem. What is the reason of these slow-down- stream-based computing was delayed for decades by the tunnel vision syndrome. The History of Systolic
Hartenstein, Reiner
A Historical Evaluation of the U16a Tunnel, Nevada National Security Site, Nye County, Nevada Volume 1
This report presents a historical evaluation of the U16a Tunnel on the Nevada National Security Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency. The U16a Tunnel was used for underground nuclear weapons effects tests in Shoshone Mountain in Area 16 of the Nevada National Security Site. Six nuclear tests were conducted in the U16a Tunnel from 1962 to 1971. These tests are Marshmallow, Gum Drop, Double Play, Ming Vase, Diamond Dust, and Diamond Mine. The U.S. Department of Defense Threat Reduction Agency, with participation from Lawrence Livermore National Laboratory and Las Alamos National Laboratory, sponsored the tests. Fifteen high explosives tests were also conducted at the tunnel. Two were calibration tests during nuclear testing and the remaining were U.S. Department of Defense, Defense Threat Reduction Agency tunnel defeat tests. The U16a Tunnel complex is on the top and slopes of Shoshone Mountain, encompassing an area of approximately 16.7 hectares (41.1 acres). Major modifications to the landscape are a result of three principal activities, road construction and maintenance, mining activities related to development of the tunnel complex, and site preparation for activities related to testing. Forty-seven cultural features were recorded at the portal and on the slopes of Shoshone Mountain. At the portal area, features relate to the mining, construction, testing, and general every day operational support activities within the tunnel. These include concrete foundations for buildings, equipment pads, and rail lines. Features on the slopes above the tunnel relate to tunnel ventilation, borehole drilling, and data recording. Feature types include soil-covered bunkers, concrete foundations, instrument cable holes, drill holes, and ventilation shafts. The U16a Tunnel complex is eligible to the National Register of Historic Places under criteria a and c, consideration g of 36 CFR Part 60.4 as a historic landscape. Scientific research conducted at the tunnel has made significant contributions to the broad patterns of our history, particularly in regard to the Cold War era that was characterized by competing social, economic, and political ideologies between the former Soviet Union and the United States. The tunnel also possesses distinctive construction and engineering methods for conducting underground nuclear tests. The Desert Research Institute recommends that the U16a Tunnel area be left in place in its current condition and that the U16a Tunnel historic landscape be included in the Nevada National Security Site monitoring program and monitored on a regular basis.
Jones, robert C [DRI; Drollinger, Harold [DRI; Bullard, Thomas F [DRI; Ashbaugh, Laurence J [DRI; Griffin, Wayne R [DRI
A Historical Evaluation of the U16a Tunnel, Nevada National Security Site, Nye County, Nevada Volume 2
Jones, Roberrt C [DRI; Drollinger, Harold [DRI
Quantum tunneling in the adiabatic Dicke model
The Dicke model describes N two-level atoms interacting with a single-mode bosonic field and exhibits a second-order phase transition from the normal to the superradiant phase. The energy levels are not degenerate in the normal phase but have degeneracy in the superradiant phase, where quantum tunneling occurs. By means of the Born-Oppenheimer approximation and the instanton method in quantum field theory, the tunneling splitting, inversely proportional to the tunneling rate for the adiabatic Dicke model, in the superradiant phase can be evaluated explicitly. It is shown that the tunneling splitting vanishes as exp(-N) for large N, whereas for small N it disappears as {radical}(N)/exp(N). The dependence of the tunneling splitting on the relevant parameters, especially on the atom-field coupling strength, is also discussed.
Chen Gang [Department of Physics, Shaoxing College of Arts and Sciences, Shaoxing 312000 (China); Institute of Theoretical Physics, Shanxi University, Taiyuan 030006 (China); Chen Zidong [Department of Physics, Shaoxing College of Arts and Sciences, Shaoxing 312000 (China); Liang Jiuqing [Institute of Theoretical Physics, Shanxi University, Taiyuan 030006 (China)
Giant tunneling magnetoresistance in silicene
We have theoretically studied ballistic electron transport in silicene under the manipulation of a pair of ferromagnetic gate. Transport properties like transmission and conductance have been calculated by the standard transfer matrix method for parallel and antiparallel magnetization configurations. It is demonstrated here that, due to the stray field-induced wave-vector filtering effect, remarkable difference in configuration-dependent transport gives rise to a giant tunneling magnetoresistance. In combination with the peculiar buckled structure of silicene and its electric tunable energy gap, the receiving magnetoresistance can be efficiently modulated by the externally-tunable stray field, electrostatic potential, and staggered sublattice potential, providing some flexible strategies to construct silicene-based nanoelectronic device.
Wang, Yu, E-mail: firstname.lastname@example.com [Department of Physics, Faculty of Science, Kunming University of Science and Technology, Kunming, 650500 Yunnan (China); Lou, Yiyi [Yiyuan Student Community, Center of Student Community Education and Management, Kunming University of Science and Technology, Kunming, 650500 Yunnan (China)
Quantitative tunneling spectroscopy of nanocrystals
The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the development of epitaxial graphene (EG), a very promising materials system with outstanding potential for nanometer-scale ballistic and coherent devices ("graphene" refers to one atomic layer of graphitic, sp2 -bonded carbon atoms [or more loosely, few layers]). Funding from this DOE grant was critical for the initial development of epitaxial graphene for nanoelectronics
First, Phillip N; Whetten, Robert L; Schaaff, T Gregory
Photon tunnelling microscopy of polyethylene single crystals
Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area
Srinivasarao, Mohan
Macroscopic quantum tunneling in Josephson junctions -
Macroscopic quantum tunneling in Josephson junctions - a method to characterise a well-shielded low Theory 5 1. The classical theory of Josephson junctions . . . . . . . . . . . . . . . . . 9 1-Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. Josephson junction dynamics . . . . . . . . . . . . . . . . . . . . . . . . 15 2.1 The basics
Gross, Rudolf
Screening and Tunneling at Metal-Surfaces
way as to satisfy continuity and charge neutrality re- quirements, and to agree with the correct work function for tungsten. Although this procedure has advantages in calculating tunneling currents (see Sec. IV), a treatment which is not fully...
KENNER, VE; Allen, Roland E.; SASLOW, WM.
SUPERCONDUCTING TUNNEL JUNCTION BOLOMETERS J. CLARKE, G. I. HOFFER and P. L. RICHARDS
69 SUPERCONDUCTING TUNNEL JUNCTION BOLOMETERS J. CLARKE, G. I. HOFFER and P. L. RICHARDS DepartmentIioration possible de ces performances. Abstract. 2014 Two new types of superconducting infrared bolometer doped germanium, are widely used as sensitive broadband infrared detectors. Superconducting bolometers
Boyer, Edmond
Le LHC, un tunnel cosmique
Et si la lumi�re au bout du tunnel du LHC �tait cosmique ? En d?autres termes, qu?est-ce que le LHC peut nous apporter dans la connaissance de l?Univers ? Car la mont�e en �nergie des acc�l�rateurs de particules nous permet de mieux appr�hender l?univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l?Univers ? La mati�re noire est-elle d�tectable au LHC ? L?�nergie noire ? Pourquoi l?antimati�re accumul�e au CERN est-elle si rare dans l?Univers ? Et si le CERN a b�ti sa r�putation sur l?exploration des forces faibles et fortes qui op�rent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l?�volution cosmique ? Depuis une trentaine d?ann�es, notre compr�hension de l?univers dans ses plus grandes dimensions et l?appr�hension de son comportement aux plus petites distances sont intimement li�es : en quoi le LHC va-t-il tester exp�rimentalement cette vision unifi�e ? Tout public, entr�e libre / R�servations au +41 (0)22 767 76 76
Theory of steady-state plane tunneling-assisted impact ionization waves
The effect of band-to-band and trap-assisted tunneling on the properties of steady-state plane ionization waves in p{sup +}-n-n{sup +} structures is theoretically analyzed. It is shown that such tunneling-assisted impact ionization waves do not differ in a qualitative sense from ordinary impact ionization waves propagating due to the avalanche multiplication of uniformly distributed seed electrons and holes. The quantitative differences of tunneling-assisted impact ionization waves from impact ionization waves are reduced to a slightly different relation between the wave velocity u and the maximum field strength E{sub M} at the front. It is shown that disregarding impact ionization does not exclude the possibility of the existence of tunneling-assisted ionization waves; however, their structure radically changes, and their velocity strongly decreases for the same E{sub M}. A comparison of the dependences u(E{sub M}) for various ionization-wave types makes it possible to determine the conditions under which one of them is dominant. In conclusion, unresolved problems concerning the theory of tunneling-assisted impact ionization waves are discussed and the directions of further studies are outlined.
Kyuregyan, A. S., E-mail: firstname.lastname@example.com [Lenin All-Russian Electrical-Engineering Institute (Russian Federation)
Method of fabricating a solar cell with a tunnel dielectric layer
Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.
Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David; Waldhauer, Ann
Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David D; Waldhauer, Ann
Chiral tunneling in single and bilayer graphene
We review chiral (Klein) tunneling in single-layer and bilayer graphene and present its semiclassical theory, including the Berry phase and the Maslov index. Peculiarities of the chiral tunneling are naturally explained in terms of classical phase space. In a one-dimensional geometry we reduced the original Dirac equation, describing the dynamics of charge carriers in the single layer graphene, to an effective Schr\\"odinger equation with a complex potential. This allowed us to study tunneling in details and obtain analytic formulas. Our predictions are compared with numerical results. We have also demonstrated that, for the case of asymmetric n-p-n junction in single layer graphene, there is total transmission for normal incidence only, side resonances are suppressed.
T. Tudorovskiy; K. J. A. Reijnders; M. I. Katsnelson
Conifolds and Tunneling in the String Landscape
We investigate flux vacua on a variety of one-parameter Calabi-Yau compactifications, and find many examples that are connected through continuous monodromy transformations. For these, we undertake a detailed analysis of the tunneling dynamics and find that tunneling trajectories typically graze the conifold point---particular 3-cycles are forced to contract during such vacuum transitions. Physically, these transitions arise from the competing effects of minimizing the energy for brane nucleation (facilitating a change in flux), versus the energy cost associated with dynamical changes in the periods of certain Calabi-Yau 3-cycles. We find that tunneling only occurs when warping due to back-reaction from the flux through the shrinking cycle is properly taken into account.
Pontus Ahlqvist; Brian R. Greene; David Kagan; Eugene A. Lim; Saswat Sarangi; I-Sheng Yang
EECBG Success Story: Topeka's "Green Light Tunnel" Saves Fuel...
Broader source: Energy.gov (indexed) [DOE]
Topeka's "Green Light Tunnel" Saves Fuel and Time EECBG Success Story: Topeka's "Green Light Tunnel" Saves Fuel and Time April 22, 2011 - 1:50pm Addthis Topeka, Kansas has...
Quantum tunneling, quantum computing, and high temperature superconductivity
observed with scanning tunneling microscope (STM) in high temperature superconductors. The integrated tunneling intensities on all predominant sites have been estimated. The results can be used to test the predictions of any tight-binding model calculation...
Wang, Qian
Electron tunneling studies of Mn12-Acetate
]. . . . . . . . . . . . . . . . 24 10 Frame for rotating the tunneling wires in the PLD chamber during deposition. The two black posts are brass that were wrapped with shrink tubing so that the wires can be attached to them and still be insulated from one another. The two white... copper posts that are made from 0.010� diameter bare copper wires. The tunneling wires are first wrapped around the copper posts and then fixed in position with PbSn solder. Although silver print and silver epoxy have also been used to connect the wires...
Ma, Lianxi
Penn Small Water Tunnel | Open Energy Information
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Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers
This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.
Chang, Y. Austin (Middleton, WI); Yang, Jianhua Joshua (Madison, WI)
Optical realization of two-boson tunneling dynamics
An optical realization of the tunneling dynamics of two interacting bosons in a double-well potential, based on light transport in a four-core microstructured fiber, is proposed. The optical setting enables to visualize in a purely classical system the entire crossover from Rabi oscillations to correlated pair tunneling and to tunneling of a fragmented pair in the fermionization limit.
Stefano Longhi
NACA0015 Measurements in LM Wind Tunnel and Turbulence
NACA0015 Measurements in LM Wind Tunnel and Turbulence Generated Noise Franck Bertagnolio Risø, Denmark November 2008 #12;Author: Franck Bertagnolio Title: NACA0015 Measurements in LM Wind Tunnel on its surface and measured in the wind tunnel at LM Glasfiber at various inflow speeds, angles of attack
Josephson inplane and tunneling currents in bilayer quantum Hall system
A Bose-Einstein condensation is formed by composite bosons in the quantum Hall state. A composite boson carries the fundamental charge (�e). We investigate Josephson tunneling of such charges in the bilayer quantum Hall system at the total filling ? = 1. We show the existence of the critical current for the tunneling current to be coherent and dissipationless in tunneling experiments with various geometries.
Ezawa, Z. F. [Nishina Center, RIKEN, Saitama 351-0198 (Japan); Tsitsishvili, G. [Georgia Department of Physics, Tbilisi State University, Tbilisi 0179 (Georgia); Sawada, A. [Research Center for Low Temperature and Materials Sciences, Kyoto University, Kyoto 606-8501 (Japan)
Superconductive tunnel junction integrated circuit
Josephson Junction integrated circuits of the current injection type and magnetically controlled type utilize a superconductive layer that forms both Josephson Junction electrode for the Josephson Junction devices on the integrated circuit as well as a ground plane for the integrated circuit. Large area Josephson Junctions are utilized for effecting contact to lower superconductive layers and islands are formed in superconductive layers to provide isolation between the groundplane function and the Josephson Junction electrode function as well as to effect crossovers. A superconductor-barrier-superconductor trilayer patterned by local anodization is also utilized with additional layers formed thereover. Methods of manufacturing the embodiments of the invention are disclosed.
Jillie, D.W. Jr.; Smith, L.N.
Effects of diesel exhaust on the microbiota within a tuffaceous tunnel system
The abundance and distribution of microbiota that may be impacted by diesel and diesel exhaust were investigated from three depths into the walls and invert (floor) of U12n tunnel at Rainier Mesa, Nevada Test Site, a potential geological analog of Yucca Mountain. Enumerations included total cell counts, and numbers of aerobic heterotrophic, sulfate-reducing, nitrate-reducing, and diesel-degrading bacteria. Additionally, the disappearance of total petroleum hydrocarbons was determined in microcosms containing subsurface materials that were amended with diesel fuel. Results revealed that microbes capable of utilizing diesel and diesel combustion products were present in the subsurface in both the walls and the invert of the tunnel. The abundance of specific bacterial types in the tunnel invert, a perturbed environment, was greater than that observed in the tunnel wall. Few trends of microbial distribution either into the tunnel wall or the invert were noted with the exception of aerobic heterotrophic abundance which increased with depth into the wall and decreased with depth into the invert. No correlation between microbiota and a specific introduced chemical species have yet been determined. The potential for microbial contamination of the tunnel wall during sampling was determined to be negligible by the use of fluorescently labeled latex spheres (1{mu}m in dia.) as tracers. Results indicate that additional investigations might be needed to examine the microbiota and their possible impacts on the geology and geochemistry of the subsurface, both indigenous microbiota and those microorganisms that will likely be introduced by anthropogenic activity associated with the construction of a high-level waste repository.
Haldeman, D.L.; Lagadinos, T.; Amy, P.S. [Univ. of Nevada, Las Vegas, NV (United States); Hersman, L. [Los Alamos National Lab., NM (United States); Meike, A. [Lawrence Livermore National Lab., Livermore, CA (United States)
Inelastic Tunneling Spectroscopy in Unconventional Superconductors
Inelastic Tunneling Spectroscopy in Unconventional Superconductors Molecular Vibration and Single Superconductors p.1/13 #12;Old Results R.C. Jaklevic and J. Lambe, Phys. Rev. Lett. 17, 1139-1140 (1966 in Unconventional Superconductors p.2/13 #12;STM observation of local inelastic mode B.C. Stipe, M.A Rezaei, and W
A Note on Real Tunneling Geometries
In the Hartle-Hawking ``no boundary'' approach to quantum cosmology, a real tunneling geometry is a configuration that represents a transition from a compact Riemannian spacetime to a Lorentzian universe. I complete an earlier proof that in three spacetime dimensions, such a transition is ``probable,'' in the sense that the required Riemannian geometry yields a genuine maximum of the semiclassical wave function.
S. Carlip
On the Superluminal Quantum Tunneling and "Causality Violation"
This is an analysis of some aspects of an old but still controversial topic, superluminal quantum tunneling. Some features of quantum tunneling described in literature, such as definition of the tunneling time and a frequency range of a signal, are discussed. The argument is presented that claim of superluminal signaling allegedly observed in frustrated internal reflection experiment was based on the wrong interpretation of the tunneling process. A thought experiment similar to that in the Tolman paradox is discussed. It shows that a new factor, attenuation, comes in the interplay between tunneled signals and macroscopic causality.
Moses Fayngold
A Historical Evaluation of the U12n Tunnel, Nevada national Security Site, Nye County, Nevada Part 2 of 2
This report presents a historical evaluation of the U12n Tunnel on the Nevada National Security Site (NNSS) in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12n Tunnel was one of a series of tunnels used for underground nuclear weapons effects tests in Rainier and Aqueduct Mesas. A total of 22 nuclear tests were conducted in the U12n Tunnel from 1967 to 1992. These tests include Midi Mist, Hudson Seal, Diana Mist, Misty North, Husky Ace, Ming Blade, Hybla Fair, Mighty Epic, Diablo Hawk, Miners Iron, Huron Landing, Diamond Ace, Mini Jade, Tomme/Midnight Zephyr, Misty Rain, Mill Yard, Diamond Beech, Middle Note, Misty Echo, Mineral Quarry, Randsburg, and Hunters Trophy. DTRA sponsored all tests except Tomme and Randsburg which were sponsored by the Lawrence Livermore National Laboratory. Midnight Zephyr, sponsored by DTRA, was an add on experiment to the Tomme test. Eleven high explosive tests were also conducted in the tunnel and included a Stemming Plan Test, the Pre-Mill Yard test, the two seismic Non-Proliferation Experiment tests, and seven Dipole Hail tests. The U12n Tunnel complex is composed of the portal and mesa areas, encompassing a total area of approximately 600 acres (240 hectares). Major modifications to the landscape have resulted from four principal activities. These are road construction and maintenance, mining activities related to development of the tunnel complex, site preparation for activities related to testing, and construction of retention ponds. A total of 202 cultural features were recorded for the portal and mesa areas. At the portal area, features relate to the mining, construction, testing, and general everyday operational support activities within the tunnel. These include concrete foundations for buildings, ventilation equipment, air compressors, communications equipment, mining equipment, rail lines, retention ponds to impound tunnel effluent, and storage containers. Features on the mesa above the tunnel generally relate to tunnel ventilation and cooling, borehole drilling, and data recording facilities. Feature types include concrete foundations, instrument cable holes, drill holes, equipment pads, ventilation shafts, and ventilation equipment. The U12n Tunnel complex is eligible to the National Register of Historic Places under criteria a and c, consideration g of 36 CFR Part 60.4 as a historic landscape. Scientific research conducted at the tunnel has made significant contributions to the broad patterns of our history, particularly in regard to the Cold War era that was characterized by competing social, economic, and political ideologies between the former Soviet Union and the United States. The tunnel also possesses distinctive construction and engineering methods for conducting underground nuclear tests. The Desert Research Institute recommends that the U12n Tunnel area be left in place in its current condition and that the U12n Tunnel historic landscape be included in the NNSS monitoring program and monitored for disturbances or alterations on a regular basis.
Drollinger, Harold [DRI; Jones, Robert C [DRI; Bullard, Thomas F [DRI; Ashbaugh, Laurence J [DRI; Griffin, Wayne R
A Historical Evaluation of the U12n Tunnel, Nevada National Security Site, Nye County, Nevada Part 1
Drollinger, Harold [DRI; Jones, Robert C [DRI; Bullard, Thomas F [DRI; Ashbaugh, Laurence J [DRI; Griffin, Wayne R [DRI
Simulation of Enhanced-Explosive Devices in Chambers and Tunnels
Introduction: Shock-dispersed fuel (SDF) explosives use a small chemical charge to disperse a combustible fuel that burns in the post-detonation environment. The energy released in the combustion process has the potential for generating higher pressures and temperatures than conventional explosives. However, the development of these types of novel explosive systems requires a detailed understanding of all of the modes of energy release. Objective: The objective of this project is develop a simulation capability for predicting explosion and combustion phase of SDF charges and apply that capability to quantifying the behavior of these types of explosives. Methodology: We approximate the dynamics of an SDF charge using high Reynolds number, fast chemistry model that effectively captures the thermodynamic behavior of SDF charges and accurately models the key modes of energy release. The overall computational model is combined with Adaptive Mesh Refinement (AMR) , implemented in a parallel adaptive framework suited to the massively parallel computer systems. Results: We have developed a multiphase version of the model and used it to simulate an SDF charge in which the dispersed fuel is aluminum flakes. Flow visualizations show that the combustion field is turbulent for the chamber and tunnel cases studied. During the 3 milli-seconds of simulation, over 90% of the Al fuel was consumed for the chamber case, while about 40% was consumed in the tunnel case in agreement with Al-SDF experiments. Significance to DoD: DoD has a requirement to develop enhanced energetic materials to support future military systems. The SDF charges described here utilize the combustion mechanism to increase energy per gram of fuel by a factor of 7 to 10 over conventional (detonating) charges, and increase the temperature of the explosion cloud to 2,000-4,000 K (depending on the SDF fuel). Accurate numerical simulation of such SDF explosions allows one to understand the energy release mechanism, and thereby design full-scale systems with greatly improved explosive efficiency.
Bell, J B; Kuhl, A L; Beckner, V E
Scanning tunneling microscope assembly, reactor, and system
An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.
Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A
Time Evolution of Tunneling in Thermal Medium -- Environment-driven Excited Tunneling --
Time evolution of tunneling phenomena proceeding in thermal medium is studied using a standard model of environment interaction. A semiclassical probability formula for the particle motion in a metastable state of one dimensional system put in thermal medium is combined with the formula of quantum penetration factor through a potential barrier, to derive the tunneling rate in medium. Effect of environment, its influence on time evolution in particular, is clarified in a real-time formalism. A nonlinear resonance effect is shown to enhance the tunneling rate at finite times of order $2/\\eta $, with $\\eta $ the friction coefficient. In the linear approximation this effect has relevance to the parametric resonance. This effect enhances the possibility of early termination of the cosmological phase transition much prior to the typical Hubble time.
Sh. Matsumoto; M. Yoshimura
Low frequency noise measurements of resonant tunnel diodes
-n junctions, and tunnel diodes 9] ~ Techniques for obtaining information such as energy levels, lifetimes, and concentrations of these conduction mechanisms have been determined for Schottky barriers, p-n junctions, and tunnel diodes. Some...LOW FREQUENCY NOISE MEASUREMENTS OF RESONANT TUNNEL DIODES A Thesis by SAMUEL SIMON VILLAREAL Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE...
Villareal, Samuel Simon
Design and Commissioning of a Wind Tunnel for Integrated Physical...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Physical and Chemical Measurements of PM Dispersing Plume of Heavy Duty Diesel Truck Design and Commissioning of a Wind Tunnel for Integrated Physical and Chemical Measurements...
Calculation of tunneling rates across a barrier with continuous potential
Here, approximate, but accurate expressions for calculation of wavefunctions and tunneling rates are obtained using the method of uniform asymptotic expansion.
Sina Khorasani
Successful but time-intensive use of high-fidelity computational capabilities for shock loading events and resultant effects on and within enclosed structures, e.g., tunnels, has led to an interest in developing more expedient methods of analysis. While several tools are currently available for the general study of the failure of structures under dynamic shock loads at a distance, presented are a pair of statistics- and physics-based tools that can be used to differentiate different types of damage (e.g., breach versus yield) as well as quantify the amount of damage within tunnels for loads close-in and with standoff. Use of such faster running tools allows for scoping and planning of more detailed model and test analysis and provides a way to address parametric sensitivity over a large multivariate space.
Glascoe, L; Morris, J; Glenn, L; Krnjajic, M
Macroscopic quantum tunneling in small Josephson junctions in a magnetic field.
We study the phenomenon of macroscopic quantum tunneling (MQT) in small Josephson junctions (JJ) with an externally applied magnetic field. The latter results in the appearance of the Fraunhofer type modulation of the current density along the barrier. The problem of MQT for a pointlike JJ is reduced to the motion of the quantum particle in the washboard potential. In the case of a finite size JJ under consideration, this problem corresponds to a MQT in a potential which itself, besides the phase, depends on space variables. The general expression for the crossover temperature To between thermally activated and macroscopic quantum tunneling regimes and the escaping time {tau}{sub esc} have been calculated.
Ovchinnikov, Yu. N.; Barone, A.; Varlamov, A. A.; Materials Science Division; Max-Planck Inst. for Physics of Complex Systems; Landau Inst. Theoretical Physics; Univ. di Napoli Federico II; Coherentia-INFM, CNR
delta-biased Josephson tunnel junctions
The behavior of a long Josephson tunnel junction drastically depends on the distribution of the dc bias current. We investigate the case in which the bias current is fed in the central point of a one-dimensional junction. Such junction configuration has been recently used to detect the persistent currents circulating in a superconducting loop. Analytical and numerical results indicate that the presence of fractional vortices leads to remarkable differences from the conventional case of uniformly distributed dc bias current. The theoretical findings are supported by detailed measurements on a number of delta-biased samples having different electrical and geometrical parameters.
Monaco, R.; Mygind, J.; Koshelets, V. P.; Dmitriev, P. [Istituto di Cibernetica del CNR, 80078 Pozzuoli (Italy) and Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Italy); DTU Physics, Technical University of Denmark, B309, DK-2800 Lyngby (Denmark); Institute of Radio Engineering and Electronics, Russian Academy of Science, Mokhovaya 11, Bldg. 7, 125009 Moscow (Russian Federation)
Penn Large Water Tunnel | Open Energy Information
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E-Print Network 3.0 - advanced wind-tunnel instrumentation Sample...
wind-tunnel instrumentation Search Powered by Explorit Topic List Advanced Search Sample search results for: advanced wind-tunnel instrumentation Page: << < 1 2 3 4 5 > >> 1...
Bifurcation tunneling dynamics in the water trimer Frank N. Keutscha)
details of the hydrogen bond tunneling dynamics in the water trimer through excitation of intermolecular6 and for a detailed molecular description of the associated hydrogen bond rear- rangement dynamics.735 Ultimately, weBifurcation tunneling dynamics in the water trimer Frank N. Keutscha) and Richard J. Saykallyb
Cohen, Ronald C.
TBM tunnel friction values for the Grizzly Powerhouse Project
Tunnel boring machine (TBM) driven water conveyance tunnels are becoming increasingly more common. Despite advances in tunnel engineering and construction technology, hydraulic performance data for TBM driven tunnels remains relatively unavailable. At the Grizzly Powerhouse Project, the TBM driven water conveyance tunnel was designed using friction coefficients developed from a previous PG&E project. A range of coefficients were selected to bound the possible hydraulic performance variations of the water conveyance system. These friction coefficients, along with the water conveyance systems characteristics, and expected turbine characteristics, were used in a hydraulic transient analysis to determine the expected system pressure fluctuations, and surge chamber performance. During startup test data, these performance characteristics were measured to allow comparison to the original design assumptions. During construction of the tunnel, plaster casts were made of the actual excavated tunnel unlined and fiber reinforced shotcrete lined surfaces. These castings were used to measure absolute roughness of the surfaces so that a friction coefficient could be developed using the Moody diagram and compare them against the design values. This paper compares the assumed frictional coefficient with computed coefficients from headlosses measured during startup testing, and plaster cast measurement calculations. In addition, a comparison of coefficients will be presented for an other TBM driven water conveyance tunnel constructed in the 1980`s.
Stutsman, R.D. [Ensign & Buckley Consulting Engineers, Larkspur, CA (United States); Rothfuss, B.D. [Pacific Gas and Electric Co., San Francisco, CA (United States)
High Tunnel Crop Production Tips Lewis W. Jett
. Specifically, high tunnels are passively vented, solar greenhouses covered with 1-2 layers of greenhouse perpendicular (at right angles) to the prevailing winds on your farm. Generally, this is a north-south direction supplemental heating systems? High tunnels should be designed and managed as passively vented and solar heated
Goodman, Robert M.
Chain Inflation via Rapid Tunneling in the Landscape
Chain inflation takes place in the string theory landscape as the universe tunnels rapidly through a series of ever lower energy vacua such as may be characterized by quantized changes in four form fluxes. The string landscape may be well suited to an early period of rapid tunneling, as required by chain inflation, followed by a later period of slow tunneling, such as may be required to explain today's dark energy and small cosmological constant. Each tunneling event (which can alternatively be thought of as a nucleation of branes) provides a fraction of an e-folding of inflation, so that hundreds of tunneling events provide the requisite amount of inflation. A specific example from M-theory compactification on manifolds with non-trivial three-cycles is presented.
Katherine Freese; James T. Liu; Douglas Spolyar
Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes
We demonstrate a GaN quantum dot ultraviolet light-emitting diode that uses tunnel injection of carriers through AlN barriers into the active region. The quantum dot heterostructure is grown by molecular beam epitaxy on AlN templates. The large lattice mismatch between GaN and AlN favors the formation of GaN quantum dots in the Stranski-Krastanov growth mode. Carrier injection by tunneling can mitigate losses incurred in hot-carrier injection in light emitting heterostructures. To achieve tunnel injection, relatively low composition AlGaN is used for n- and p-type layers to simultaneously take advantage of effective band alignment and efficient doping. The small height of the quantum dots results in short-wavelength emission and are simultaneously an effective tool to fight the reduction of oscillator strength from quantum-confined Stark effect due to polarization fields. The strong quantum confinement results in room-temperature electroluminescence peaks at 261 and 340 nm, well above the 365 nm bandgap of bulk GaN. The demonstration opens the doorway to exploit many varied features of quantum dot physics to realize high-efficiency short-wavelength light sources.
Verma, Jai; Kandaswamy, Prem Kumar; Protasenko, Vladimir; Verma, Amit; Grace Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)] [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)
Localization of gauge fields and monopole tunnelling
We study the dynamical localization of a massless gauge field on a lower-dimensional surface (2-brane). In flat space, the necessary and sufficient condition for this phenomenon is the existence of confinement in the bulk. The resulting configuration is equivalent to a dual Josephson junction. This duality leads to an interesting puzzle, as it implies that a localized massless theory, even in the Abelian case, must become confining at exponentially large distances. Through the use of topological arguments we clarify the physics behind this large-distance confinement and identify the instantons of the brane world-volume theory that are responsible for its appearance. We show that they correspond to the (condensed) bulk magnetic charges (monopoles), that occasionally tunnel through the brane and induce weak confinement of the brane theory. We consider the possible generalization of this effect to higher dimensions and discuss phenomenological bounds on the confinement of electric charges at exponentially large distances within our Universe.
Dvali, G. [CERN, Theory Division, CH-1211 Geneva 23 (Switzerland); Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, New York 10003 (United States); Nielsen, H. B. [CERN, Theory Division, CH-1211 Geneva 23 (Switzerland); Niels Bohr Institute, Copenhagen DK 2100 (Denmark); Tetradis, N. [Department of Physics, University of Athens, Zographou 157 84, Athens (Greece)
Instanton solutions mediating tunneling between the degenerate vacua in curved space
We investigate the instanton solution between the degenerate vacua in curved space. We show that there exist O(4)-symmetric solutions not only in de Sitter but also in both flat and anti-de Sitter space. The geometry of the new type of solutions is finite and preserves the Z{sub 2} symmetry. The nontrivial solution corresponding to the tunneling is possible only if gravity is taken into account. The numerical solutions as well as the analytic computations using the thin-wall approximation are presented. We expect that these solutions do not have any negative mode as in the instanton solution.
Lee, Bum-Hoon; Lee, Wonwoo [Department of Physics and BK21 Division, and Center for Quantum Spacetime, Sogang University, Seoul 121-742 (Korea, Republic of); Lee, Chul H. [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Oh, Changheon [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Principal Researcher Center, Technovation Partners, Seoul 135-824 (Korea, Republic of)
ORGANIC RASPBERRY PRODUCTION UNDER HIGH TUNNELS Eric Hanson
, and applied to the surface in 2011 and 2012. Incorporated compost caused some salt. Both compost and fertilizer appeared to supply adequate nitrogen early for conventional raspberries under tunnels, which can exceed 18,000 lb per acre. Several
Ultrafast resolution of tunneling delay time ALEXANDRA S. LANDSMAN,,
laser physics; (020.4180) Multiphoton processes; (240.7040) Tunneling. http://dx.doi.org/10.1364/OPTICA Vol. 1, No. 5 / November 2014 / Optica 343 #12;Observable 1 is the polarization axis
Keller, Ursula
Effect of anisotropy in ground movements caused by tunnelling
This paper presents closed-form analytical solutions for estimating far-field ground deformations caused by shallow tunnelling in a linear elastic soil mass with cross-anisotropic stiffness properties. The solutions describe ...
Zymnis, Despina Maria
Tunneling from super- to normal-deformed minima in nuclei.
An excited minimum, or false vacuum, gives rise to a highly elongated superdeformed (SD) nucleus. A brief review of superdeformation is given, with emphasis on the tunneling from the false to the true vacuum, which occurs in the feeding and decay of SD bands. During the feeding process the tunneling is between hot states, while in the decay it is from a cold to a hot state. The {gamma} spectra connecting SD and normal-deformed (ND) states provide information on several physics issues: the decay mechanism; the spin/parity quantum numbers, energies and microscopic structures of SD bands; the origin of identical SD bands; the quenching of pairing with excitation energy; and the chaoticity of excited ND states at 2.5-5 MeV. Other examples of tunneling in nuclei, which are briefly described, include the possible role of tunneling in {Delta}I = 4 bifurcation in SD bands, sub-barrier fusion and proton emitters.
Khoo, T. L.
Computational design and analysis of flatback airfoil wind tunnel experiment.
Vacuum gaps with small tunnel currents at large electric field...
with small tunnel currents at large electric field and its potential applications for energy storage, charge storage and power supplies. Friday, May 27, 2011 - 4:00pm SSRL...
Effect of existing building on tunneling-induced ground movements
The goal of this thesis is to assess the influence of an existing structure on tunneling-induced ground movements. This is accomplished through 2D numerical simulations that are compared with similar prior studies reported ...
Law, Rachel Hoi-chee
One Hair Postulate for Hawking Radiation as Tunneling Process
For Hawking radiation, treated as a tunneling process, the no-hair theorem of black hole together with the law of energy conservation is utilized to postulate that the tunneling rate only depends on the external qualities (e.g., the mass for the Schwarzschild black hole) and the energy of the radiated particle. This postulate is justified by the WKB approximation for calculating the tunneling probability. Based on this postulate, a general formula for the tunneling probability is derived without referring to the concrete form of black hole metric. This formula implies an intrinsic correlation between the successive processes of the black hole radiation of two or more particles. It also suggests a kind of entropy conservation and thus resolves the puzzle of black hole information loss in some sense.
H. Dong; Qing-yu Cai; X. F. Liu; C. P. Sun
Direct determination of exact charge states of surface point defects using scanning tunneling microscopy: As vacancies on GaAs ,,110...
microscopy: As vacancies on GaAs ,,110... Kuo-Jen Chao, Arthur R. Smith, and Chih-Kang Shih* Department of the charge state of surface As vacancies on p-type GaAs 110 using scanning tunneling microscopy. This method utilizes the compensation between the local band bending result- ing from the As vacancy and the p
Theory of Extrinsic and Intrinsic Tunnelling in Cuprate Superconductors
A theory capable of explaining intrinsic and extrinsic tunnelling conductance in underdoped cuprates has been devised that accounts for the existence of two energy scales, their temperature and doping dependencies. The asymmetry and inhomogeneity seen in extrinsic (normal metal - superconductor (NS)) tunnelling and the normal-state gapped intrinsic (SS) conductance is explained, as well as the superconducting gap and normal state pseudogap and the temperature dependence of the full gap.
J. Beanland; A. S. Alexandrov
Photon tunneling in the warp drive space-time
We simplify the warp drive space-time such that it becomes stationary and the distorsion becomes one-dimensional and static. We use this simplified space-time as the classical background space-time for a photon field. The Drummond&Hathrell action is then used in order to investigate the velocity effects on photons tunneling through the space-time distorsion. We speculate on whether or not all tunneling processes with photons induce faster than light effects.
Cramer, C R
Two-Color Ultrafast Photoexcited Scanning Tunneling Microscopy
We report on two-color two-photon photoexcitation of a metal surface driven by ultrafast laser pulses and detected with a scanning tunneling microscope (STM) tip as a proximate anode. Results are presented for two cases: (i) where the tip is retracted from the surface far enough to prohibit tunneling, and (ii) where the tip is within tunneling range of the surface. A delay-modulation technique is implemented to isolate the two-color photoemission from concurrent one-color two-photon photoemission and provide subpicosecond time-resolved detection. When applied with the tip in tunneling range, this approach effectively isolates the two-photon photoexcited current signal from the conventional tunneling current and enables subpicosecond time-resolved detection of the photoexcited surface electrons. The advantage of the two-color approach is highlighted by comparison with the one-color case where optical interference causes thermal modulation of the STM tip length, resulting in tunneling current modulations that are orders of magnitude larger than the current due to photoexcitation of surface electrons. By completely eliminating this interference, and thereby avoiding thermal modulation of the STM tip length, the two-color approach represents an important step toward the ultimate goal of simultaneous subnanometer and subpicosecond measurements of surface electron dynamics by ultrafast-laser-excited STM.
Camillone, N.; Dolocan, A.; Acharya, D.P.; Zahl, P.; Sutter, P.
Tunneling conductance studies in the ion-beam sputtered CoFe/Mg/MgO/NiFe magnetic tunnel junctions
Magnetic tunnel junctions consisting of CoFe(10 nm)/Mg(1 nm)/MgO(3.5 nm)/NiFe(10 nm) are grown at room temperature using dual ion beam sputtering via in-situ shadow masking. The effective barrier thickness and average barrier height are estimated to be 3.5 nm (2.9 nm) and 0.69 eV (1.09 eV) at 290 K (70 K), respectively. The tunnel magnetoresistance value of 0.2 % and 2.3 % was observed at 290 K and 60 K, respectively. The temperature dependence of tunneling conductance revealed the presence of localized states present within the forbidden gap of the MgO barrier leading to finite inelastic spin independent tunneling contributions, which degrade the TMR value.
Singh, Braj Bhusan; Chaudhary, Sujeet [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)
Measurements and computations of second-mode instability waves in three hypersonic wind tunnels.
High-frequency pressure-fluctuation measurements were made in AEDC Tunnel 9 at Mach 10 and the NASA Langley 15-Inch Mach 6 and 31-Inch Mach 10 tunnels. Measurements were made on a 7{sup o}-half-angle cone model. Pitot measurements of freestream pressure fluctuations were also made in Tunnel 9 and the Langley Mach-6 tunnel. For the first time, second-mode waves were measured in all of these tunnels, using 1-MHz-response pressure sensors. In Tunnel 9, second-mode waves could be seen in power spectra computed from records as short as 80 {micro}s. The second-mode wave amplitudes were observed to saturate and then begin to decrease in the Langley tunnels, indicating wave breakdown. Breakdown was estimated to occur near N {approx} 5 in the Langley Mach-10 tunnel. The unit-Reynolds-number variations in the data from Tunnel 9 were too large to see the same processes.
Lewis, Daniel R. (Aerospace Testing Alliance, Silver Spring, MD); Alba, Christopher R. (Air Force Research Laboratory, Wright-Patterson AFB, OH); Rufer, Shann J. (NASA Langley Research Center, Hampton, VA); Beresh, Steven Jay; Casper, Katya M.; Berridge, Dennis C. (Purdue University, West Lafayette, IN); Schneider, Steven P. (Purdue University, West Lafayette, IN)
Report Tunneling Cost Reduction Study prepared for Fermilab
Fermi National Accelerator Laboratories has a need to review the costs of constructing the very long tunnels which would be required for housing the equipment for the proposed Very Large Hadron Collider (VLHC) project. Current tunneling costs are high, and the identification of potential means of significantly reducing them, and thereby helping to keep overall project costs within an acceptable budget, has assumed great importance. Fermilab has contracted with The Robbins Company to provide an up-to-date appraisal of tunneling technology, and to review the potential for substantially improving currently the state-of-practice performance and construction costs in particular. The Robbins Company was chosen for this task because of its long and successful experience in hard rock mechanical tunnel boring. In the past 40 years, Robbins has manufactured over 250 tunneling machines, the vast majority for hard rock applications. In addition to also supplying back-up equipment, Robbins has recently established a division dedicated to the manufacture of continuous conveying equipment for the efficient support of tunneling operations. The study extends beyond the tunnel boring machine (TBM) itself, and into the critical area of the logistics of the support of the machine as it advances, including manpower. It is restricted to proven methods using conventional technology, and its potential for incremental but meaningful improvement, rather than examining exotic and undeveloped means of rock excavation that have been proposed from time to time by the technical community. This is the first phase of what is expected to be a number of studies in increasing depth of technical detail, and as such has been restricted to the issues connected with the initial 34 kilometer circumference booster tunnel, and not the proposed 500 kilometer circumference tunnel housing the VLHC itself. The booster tunnel is entirely sited within low to medium strength limestone and dolomite formations, typical of the Chicago area. The rock is generally competent with widely spaced jointing, and slowdown of the operation for the installation of rock support is expected to be minimal. The tunneling system will have to be equipped with the necessary equipment for an efficient response to poor rock conditions however. Because the ground conditions are expected to be very favorable, a state-of-the-art TBM should have no difficulty in excavating at a high penetration rate of 10 meters per hour or more in rock of the average of the range of strengths stated to exist. Disc cutter changes will be few as the rock has very low abrasivity. However, experience has shown that overall tunneling rates are a relatively low percentage of the machine's penetration rate capability. Therefore the main focus of improvement is guaranteeing that the support systems, including mucking and advance of the utilities do not impede the operation. Improved mechanization of the support systems, along with automation where practicable to reduce manpower, is seen as the best means of raising the overall speed of the operation, and reducing its cost. The first phase of the study is mainly involved with establishing the baseline for current performance, and in identifying areas of improvement. It contains information on existing machine design concepts and provides data on many aspects of the mechanical tunneling process, including costs and labor requirements. While it contains suggestions for technical improvements of the various system, the time limitations of this phase have not permitted any detailed concept development. This should be a major part of the next phase.
Not Available
Ventilation and Suppression Systems in Road Tunnels: Some Issues regarding their Appropriate Use in a Fire Emergency�
Two important tunnel safety technologies are addressed. The majority of long road tunnels have ventilation systems. In the event of a fire in a tunnel, such systems will influence fire development in a number of different ...
Carvel, Ricky O; Rein, Guillermo; Torero, Jose L
2-dimensional hyperbolic medium for electrons and photons based on the array of tunnel-coupled graphene nanoribbons
We study the electronic band structure and optical conductivity of an array of tunnel-coupled array of graphene nanoribbons. We show that due to the coupling of electronic edge states for the zigzag nanoribbon structure, the Fermi surface can become a hyperbola similarly to the case of the layered metal-dielectric structures, where the hyperbolic isofrequency contours originate from the coupling of localized surface plasmon polaritons. Moreover, we show that for both types of the ribbon edge, the optical response of the structure can be characterized by a uniaxial conductivity tensor, having principal components of the different signs. Therefore, the tunnel-coupled nanoribbon array can be regarded as a tunable hyperbolic metasurface.
Iorsh, Ivan
The H-Canyon at Savannah River Site is a large concrete structure designed for chemical separation processes of radioactive material. The facility requires a large ventilation system to maintain negative pressure in process areas for radioactive contamination control and personnel protection. The ventilation exhaust is directed through a concrete tunnel under the facility which is approximately five feet wide and 8 feet tall that leads to a sand filter and stack. Acidic vapors in the exhaust have had a degrading effect on the surface of the concrete tunnels. Some areas have been inspected; however, the condition of other areas is unknown. Experience from historical inspections with remote controlled vehicles will be discussed along with the current challenge of inspecting levels below available access points. The area of interest in the exhaust tunnel must be accessed through a 14 X 14 inch concrete plug in the floor of the hot gang valve corridor. The purpose for the inspection is to determine the condition of the inside of the air tunnel and establish if there are any structural concerns. Various landmarks, pipe hangers and exposed rebar are used as reference points for the structural engineers when evaluating the current integrity of the air tunnel.
Minichan, R.; Fogle, R.; Marzolf, A.
Baker-Barry Tunnel Lighting: Evaluation of a Potential GATEWAY Demonstrations Project
The U.S. Department of Energy is evaluating the Baker-Barry Tunnel as a potential GATEWAY Demonstrations project for deployment of solid-state lighting (SSL) technology. The National Park Service views this project as a possible proving ground and template for implementation of light-emitting diode (LED) luminaires in other tunnels, thereby expanding the estimated 40% energy savings from 132 MWh/yr to a much larger figure nationally. Most of the energy savings in this application is attributable to the instant-restrike capability of LED products and to their high tolerance for frequent on/off switching, used here to separately control either end of the tunnel during daytime hours. Some LED luminaires rival or outperform their high-intensity discharge (HID) counterparts in terms of efficacy, but options are limited, and smaller lumen packages preclude true one-for-one equivalence. However, LED products continue to improve in efficacy and affordability at a rate unmatched by other light source technologies; the estimated simple payback period of eight years (excluding installation costs and maintenance savings) can be expected to improve with time. The proposed revisions to the existing high-pressure sodium (HPS) lighting system would require slightly increased controls complexity and significantly increased luminaire types and quantities. In exchange, substantial annual savings (from reduced maintenance and energy use) would be complemented by improved quantity and quality of illumination. Although advanced lighting controls could offer additional savings, it is unclear whether such a system would prove cost-effective; this topic may be explored in future work.
Tuenge, Jason R.
Temperature study of Zero Bias Features using self-assembling tunnel junctions
The significant reduction in the conductance of a tunneling system near zero bias voltage is termed the Zero Bias Feature (ZBF). A �He cryostat has been modified to incorporate a Self-Assembling Tunnel Junction (SATJ), capable of performing...
Savitski, Stephen Ronald
E-Print Network 3.0 - aerothermal wind tunnel Sample Search Results
aerothermal wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: aerothermal wind tunnel Page: << < 1 2 3 4 5 > >> 1 Pour l'obtention du...
E-Print Network 3.0 - aerosol wind tunnel Sample Search Results
wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: aerosol wind tunnel Page: << < 1 2 3 4 5 > >> 1 LA-UR-00-3091 Approved for public...
E-Print Network 3.0 - airfoil wind tunnel Sample Search Results
wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: airfoil wind tunnel Page: << < 1 2 3 4 5 > >> 1 Flexible-Membrane Airfoils at Low...
E-Print Network 3.0 - altitude wind tunnel Sample Search Results
wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: altitude wind tunnel Page: << < 1 2 3 4 5 > >> 1 For more than 45 years, The University...
E-Print Network 3.0 - ames wind tunnel Sample Search Results
wind tunnel Search Powered by Explorit Topic List Advanced Search Sample search results for: ames wind tunnel Page: << < 1 2 3 4 5 > >> 1 IOWA STATE UNIVERSITY WIND SIMULATION AND...
Effects of tunneling on groundwater flow and swelling of clay-sulfate rocks
[1] Swelling of clay-sulfate rocks is a major threat in tunneling. It is triggered by the transformation of the sulfate mineral anhydrite into gypsum as a result of water inflow in anhydrite-containing layers after tunnel ...
Butscher, Christoph
Development of the resource model for the Decision Aids for Tunneling (DAT)
The Decision Aids for Tunneling (DAT) are a computer based method with which distributions of tunnel construction time and cost as well as required and produced resources can be estimated considering uncertainties in ...
Min, Sangyoon, 1973-
Nanopillar Spin Filter Tunnel Junctions with Manganite Barriers
promising FI tunnel barrier material for SFTJ. In this work, we investigate the spin filtering properties of Sm0.75Sr0.25MnO3 (SSMO) manganite ultrathin films in LNO/SSMO/LNO tunnel junctions. SSMO films were grown by pulsed laser deposition (PLD) onto Sr... -plane rotation vis-�-vis the substrate, i.e. the alignment of [110] of orthorhombic SSMO with the [100] of the underlying cubic SrTiO3 (STO) substrate. Film thickness was calculated from both X-ray reflectivity (not shown) and diffraction fringes around the (004...
Prasad, Bhagwati; Egilmez, Mehmet; Schoofs, Frank; Fix, Thomas; Vickers, Mary E; Zhang, Wenrui; Jian, Jie; Wang, Haiyan; Blamire, Mark G
Hawking temperature of rotating charged black strings from tunneling
Thermal radiations from spherically symmetric black holes have been studied from the point of view of quantum tunneling. In this paper we extend this approach to study radiation of fermions from charged and rotating black strings. Using WKB approximation and Hamilton-Jacobi method we work out the tunneling probabilities of incoming and outgoing fermions and find the correct Hawking temperature for these objects. We show that in appropriate limits the results reduce to those for the uncharged and non-rotating black strings.
Ahmed, Jamil; Saifullah, K., E-mail: email@example.com, E-mail: email@example.com [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)
Characteristics of high-transmission-probability tunnel junctions for use as particle detectors
Interest in the problem of the galactic dark matter has stimulated development of particle detectors sensitive to very low energies. Superconducting tunnel junctions may be useful in such detectors. We describe here superconducting tunnel junctions with thin barriers which may be suitable for this purpose. We present I-V characteristics and data on the temperature dependence of the subgap tunneling current. We also present some scanning-electron-microscope observations of the thin films of the tunnel junctions.
Stricker, D.A.; Alba, G.P.; Anderson, C.C.; Bing, D.D.; Bland, R.W.; Dickson, S.C.; Dignan, T.G.; Gagnon, P.; Johnson, R.T.; Seneclauze, C.M.
Interest in the problem of the galactic dark matter has stimulated development of particle detectors sensitive to very low energies. Superconducting tunnel junctions may be useful in such detectors. The authors describe superconducting tunnel junctions with thin barriers which may be suitable for this purpose. They present I-V characteristics and data on the temperature dependence of the subgap tunneling current. They also present some scanning-electron-microscope observations of the thin films of the tunnel junctions.
Programming Wireless Sensor Networks with Logical Neighborhoods: A Road Tunnel Use Case
on sensed data, the system operates a variety of devices, such as ventilation fans inside the tunnel
Picco, Gian Pietro
Molecularly Resolved Images of Peptide-Functionalized Gold Surfaces by Scanning Tunneling Microscopy
Molecularly Resolved Images of Peptide-Functionalized Gold Surfaces by Scanning Tunneling propargylglycine unnatural functional groups 20 � apart and an alkanethiol self-assembled monolayer (SAM) on a gold-terminated surfaces were imaged by scanning tunneling microscopy (STM) using a low tunneling current of 10 p
Webb, Lauren J.
Observation of Turbulent Intermittency Scaling with Magnetic Helicity in an MHD Plasma Wind Tunnel
. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays-tunnel configuration of the Swarthmore Spheromak Experiment (SSX) [16,17] explores this possible relationship between indices. The scan is conducted on the wind-tunnel configuration of the Swarthmore Spheromak Experiment
Brown, Michael R.
Influence of dimensionality on deep tunneling rates: A study based on the hydrogen-nickel system
, such as hydrogen embrittlement, catalysis, and fuel storage.1 Moreover, tunneling draws fundamental interest sinceInfluence of dimensionality on deep tunneling rates: A study based on the hydrogen-nickel system hydrogen into a surface site of a nickel crystal is used to investigate deep tunneling phenomena. A method
Zeiri, Yehuda
Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System
Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System Lichuan Gui in wind tunnel tests with a stereo high-speed imaging system. The imaging system includes two high angle, pitch angle and yaw angle of the aerodynamic model in the wind tunnel. Tests and simulations were
Gui, Lichuan
Role of bias voltage and tunneling current in the perpendicular displacements of freestanding graphene via scanning
graphene via scanning tunneling microscopy Peng Xu, Steven D. Barber, Matthew L. Ackerman, James Kevin measurements of freestanding graphene as a function of applied bias voltage and tunneling current setpoint, the graphene approaches the STM tip, while, on the other hand, when the tunneling current is increased
Thibado, Paul M.
Developing a Practical Wind Tunnel Test Engineering Course for Undergraduate Aerospace Engineering Students
This thesis describes the development and assessment of an undergraduate wind tunnel test engineering course utilizing the 7ft by 10ft Oran W. Nicks Low Speed Wind Tunnel (LSWT). Only 5 other universities in the United States have a wind tunnel...
Recla, Benjamin Jeremiah
Tunnel optical radiation in In{sub x}Ga{sub 1?x}N
An investigation of tunnel optical radiation in epitaxial layers of n-type In{sub x}Ga{sub 1?x}N grown on p-type GaN by novel plasma based migration enhanced epitaxy is presented. Experimental results of electro-luminescence spectra for In{sub x}Ga{sub 1?x}N/p?GaN hetero-junctions were obtained and they show two well expressed optical bands - one in range 500-540 nm and other in range 550-610 nm. An interesting detail is that each band begins and ends by sharp drops of the radiation, which nearly approach zero. A theoretical investigation of the unusual behavior of these spectra was done using LCAO electron band structure calculations. The optical ranges of these bands show that the radiation occurs in the In{sub x}Ga{sub 1?x}N region. In fact, substitutions of In atoms in Ga sites creates defects in the structure of In{sub x}Ga{sub 1?x}N and the corresponding LCAO matrix elements are found on this basis. The LCAO electron band structures are calculated considering the interactions between nearest-neighbor orbitals. Electron energy pockets are found in both the conduction and the valence bands at the ? point of the electron band structures. Also it is found that these pockets are separated by distances, for which there is overlapping between the electron wave functions describing localized states belonging to the pockets, and as a result tunnel optical radiation can take place. This type of electron transition - between such a pocket in the conduction band and a pocket in the valence band - occurs in In{sub x}Ga{sub 1?x}N, causing the above described optical bands. This conclusion concurs with the fact that the shapes of these bands change with change of the applied voltage.
Alexandrov, Dimiter; Skerget, Shawn [Semiconductor Research Laboratory, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B5E1 (Canada)
Periodic orbit theory of chaotic tunneling Olivier Sigwarth
pre cisely in this organization into nearly cancelling combinations: cycle expansions are dominated Cvitanovi'c April 17, 1998 PACS: 03.20.+i, 03.65.Sq, 05.40.+j, 05.45.+b keywords: cycle expansions, periodic orbits, dynamical zeta functions, quantum tunneling. Abstract 1 cycle expansions. 1 Introduction
Cvitanovc', Predrag
The Tunnel Vision Syndrome: Challenging Computer Science Education
The Tunnel Vision Syndrome: Challenging Computer Science Education Reiner Hartenstein1 Professor levels from compilers over execution devices down to all levels of storage behavior, challenging all, and programming. Overcoming the von-Neumann- syndrome-based mind set would be a fascinating job for computer
area lhc tunnel: Topics by E-print Network
Keith 2006-01-01 9 A High Luminosity e+e- Collider in the LHC tunnel to study the Higgs Boson HEP - Experiment (arXiv) Summary: We consider the possibility of a 120x120 GeV e+e-...
Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes
Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes B. J. LeRoy,a) S. G-wall carbon nanotubes that are freely suspended over a trench. The nanotubes were grown by chemical vapor on the freestanding portions of the nanotubes. Spatially resolved spectroscopy on the suspended portion of both
Dekker, Cees
Tunnel MOS Heterostructure Field Effect Transistor for RF Switching Applications
6 dry etching on the trap density and trap state energy of AlGaN surface are investigated using the GP/w- w method. Various tunneling mechanisms at different biases are then characterized in samples and compared with each other. To improve...
Rezanezhad Gatabi, Iman
Exercice session Cargse, October 2008 Klein tunneling in graphene
Exercice session Cargèse, October 2008 Klein tunneling in graphene Pierre Allain and Jean-Noël Fuchs 1 Introduction : plane wave The goal is to compute the probability transmission T of a graphene 1 = n2 sin 2 for an electron in graphene and show that the optical index n is proportional
Paris-Sud 11, Université de
Quantum Terahertz Electrodynamics and Macroscopic Quantum Tunneling in Layered Superconductors
of macroscopic quantum tunneling (MQT) in stacks of intrinsic Josephson junctions. Because of the long numbers: 74.72.Hs, 74.78.Fk The recent surge of interest in stacks of intrinsic Josephson junctions of stacks of Josephson junctions in quantum electronics [6]. This requires a quantum theory capable
Nori, Franco
Particle pulses from superconducting aluminum tunnel junction detectors
Superconducting aluminum tunnel junctions have been developed for use as particle detectors. This paper presents results on static characteristics of these devices. We also present results from tests of these detectors with 6-keV X-rays. An extrapolation of the properties of these detectors to one suitable for dark-matter detectors is discussed.
Stricker, D.A.; Bing, D.D.; Bland, R.W.; Dickson, S.C.; Dignan, T.; Johnson, R.T.; Lockhart, J.M.; Laws, K.; Simon, M.W.; Watson, R. (San Francisco State Univ., Physics and Astronomy Dept. San Francisco, CA (US))
A Ray Tracing Algorithm for Intelligent Transport Systems in Tunnels
, Lund University, Lund, Sweden Abstract--It is well-known that the radio wave propagation mechanisms of time- varying power delay profile analysis. Secondly we introduce a RT tool that includes influence of the moving objects, to predict wave propagation mechanisms in the tunnel. In order to reduce computational
Zemen, Thomas
Tunneling control using classical non-linear oscillator
A quantum particle is placed in symmetric double well potential which is coupled to a classical non-linear oscillator via a coupling function. With different spatial symmetry of the coupling and under various controlling fashions, the tunneling of the quantum particle can be enhanced or suppressed, or totally destroyed.
Kar, Susmita [Department of Physical Chemistry, Indian Association for the Cultivation of Science, Kolkata -700032 (India); Bhattacharyya, S. P., E-mail: firstname.lastname@example.com [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai- 400076 (India)
Tunnel junction multiple wavelength light-emitting diodes
A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect. 5 figs.
Olson, J.M.; Kurtz, S.R.
A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.
Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)
Macroscopic quantum tunneling and the 'cosmic' Josephson effect
We discuss the possible influence of a cosmic magnetic field on the macroscopic quantum tunneling process associated, in a cosmological context, to the decay of the 'false vacuum'. We find a close analogy with the effects of an external magnetic field applied to a Josephson junction in the context of low-temperature/high-temperature superconducting devices.
Barone, A. [Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II', CNR-SPIN, Piazzale Tecchio 21, 80125 Napoli (Italy); Gasperini, M. [Dipartimento di Fisica, Universita di Bari, Via G. Amendola 173, 70126 Bari (Italy); INFN, Sezione di Bari, Bari (Italy); Rotoli, G. [Dipartimento di Ingegneria dell'Informazione, Seconda Universita di Napoli (SUN), Via Roma 29, 81031 Aversa (CE) (Italy)
Primary Electronic Thermometry Using the Shot Noise of a Tunnel
. Lehnert,1,2 I. Siddiqi,1 R. J. Schoelkopf1 We present a thermometer based on the electrical noise from a tunnel junction. In this thermometer, temperature is related to the voltage across the junction thermometer over four orders of magnitude in temperature, with as high as 0.1% accuracy and 0.02% precision
Relation between quantum tunneling times for relativistic particles
A general relation between the phase time (group delay) and the dwell time is derived for relativistic tunneling particles described by the Dirac equation. It is shown that the phase time equals the dwell time plus a self-interference delay which is a relativistic generalization of previous results.
Winful, Herbert G.; Ngom, Moussa; Litchinitser, Natalia M. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States); Applied Physics Program, University of Michigan, 2477 Randall Laboratory, Ann Arbor, Michigan 48109-1120 (United States); Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States)
Analysis of the energy distribution of interface traps related to tunnel oxide degradation using charge pumping techniques for 3D NAND flash applications
Graphical abstract: The degradation tendency extracted by CP technique was almost the same in both the bulk-type and TFT-type cells. - Highlights: � D{sub it} is directly investigated from bulk-type and TFT-type CTF memory. � Charge pumping technique was employed to analyze the D{sub it} information. � To apply the CP technique to monitor the reliability of the 3D NAND flash. - Abstract: The energy distribution and density of interface traps (D{sub it}) are directly investigated from bulk-type and thin-film transistor (TFT)-type charge trap flash memory cells with tunnel oxide degradation, under program/erase (P/E) cycling using a charge pumping (CP) technique, in view of application in a 3-demension stackable NAND flash memory cell. After P/E cycling in bulk-type devices, the interface trap density gradually increased from 1.55 � 10{sup 12} cm{sup ?2} eV{sup ?1} to 3.66 � 10{sup 13} cm{sup ?2} eV{sup ?1} due to tunnel oxide damage, which was consistent with the subthreshold swing and transconductance degradation after P/E cycling. Its distribution moved toward shallow energy levels with increasing cycling numbers, which coincided with the decay rate degradation with short-term retention time. The tendency extracted with the CP technique for D{sub it} of the TFT-type cells was similar to those of bulk-type cells.
An, Ho-Myoung; Kim, Hee-Dong; Kim, Tae Geun, E-mail: email@example.com
Infrared spectra and tunneling dynamics of the N{sub 2}�D{sub 2}O and OC�D{sub 2}O complexes in the v{sub 2} bend region of D{sub 2}O
The rovibrational spectra of the N{sub 2}�D{sub 2}O and OC�D{sub 2}O complexes in the v{sub 2} bend region of D{sub 2}O have been measured in a supersonic slit jet expansion using a rapid-scan tunable diode laser spectrometer. Both a-type and b-type transitions were observed for these two complexes. All transitions are doubled, due to the heavy water tunneling within the complexes. Assuming the tunneling splittings are the same in K{sub a} = 0 and K{sub a} = 1, the band origins, all three rotational and several distortion constants of each tunneling state were determined for N{sub 2}�D{sub 2}O in the ground and excited vibrational states, and for OC�D{sub 2}O in the excited vibrational state, respectively. The averaged band origin of OC�D{sub 2}O is blueshifted by 2.241 cm{sup ?1} from that of the v{sub 2} band of the D{sub 2}O monomer, compared with 1.247 cm{sup ?1} for N{sub 2}�D{sub 2}O. The tunneling splitting of N{sub 2}�D{sub 2}O in the ground state is 0.16359(28) cm{sup ?1}, which is about five times that of OC�D{sub 2}O. The tunneling splittings decrease by about 26% for N{sub 2}�D{sub 2}O and 23% for OC�D{sub 2}O, respectively, upon excitation of the D{sub 2}O bending vibration, indicating an increase of the tunneling barrier in the excited vibrational state. The tunneling splittings are found to have a strong dependence on intramolecular vibrational excitation as well as a weak dependence on quantum number K{sub a}.
Zhu, Yu; Zheng, Rui; Li, Song; Yang, Yu; Duan, Chuanxi, E-mail: firstname.lastname@example.com [College of Physical Science and Technology, Central China Normal University, Wuhan 430079 (China)] [College of Physical Science and Technology, Central China Normal University, Wuhan 430079 (China)
Strained-Si1-xGex/Si Band-to-Band Tunneling Transistors: Impact of Tunnel-Junction Germanium Composition and Doping Concentration on Switching Behavior
Strained pseudomorphic Si/Si [subscript 1-x]Ge [subscript x]/Si gate-controlled band-to-band tunneling (BTBT) devices have been analyzed with varying Ge composition up to 57% and p+ tunnel-junction (source) doping concentration ...
Antoniadis, Dimitri A.
Tunnel and Subsurface Void Detection and Range to Target Measurement
Engineers and technicians at the Idaho National Laboratory invented, designed, built and tested a device capable of detecting and measuring the distance to, an underground void, or tunnel. Preliminary tests demonstrated positive detection of, and range to, a void thru as much as 30 meters of top-soil earth. Device uses acoustic driving point impedance principles pioneered by the Laboratory for well-bore physical properties logging. Data receipts recorded by the device indicates constructive-destructive interference patterns characteristic of acoustic wave reflection from a downward step-change in impedance mismatch. Prototype tests demonstrated that interference patterns in receipt waves could depict the patterns indicative of specific distances. A tool with this capability can quickly (in seconds) indicate the presence and depth/distance of a void or tunnel. Using such a device, border security and military personnel can identify threats of intrusion or weapons caches in most all soil conditions including moist and rocky.
Phillip B. West
Hanford facility dangerous waste permit application, PUREX storage tunnels
The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOE/RL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion is limited to Part B permit application documentation submitted for individual, operating treatment, storage, and/or disposal units, such as the PUREX Storage Tunnels (this document, DOE/RL-90-24). Both the General Information and Unit-Specific portions of the Hanford Facility Dangerous Waste Permit Application address the content of the Part B permit application guidance prepared by the Washington State Department of Ecology (Ecology 1996) and the US Environmental Protection Agency (40 Code of Federal Regulations 270), with additional information needs defined by the Hazardous and Solid Waste Amendments and revisions of Washington Administrative Code 173-303. For ease of reference, the Washington State Department of Ecology alpha-numeric section identifiers from the permit application guidance documentation (Ecology 1996) follow, in brackets, the chapter headings and subheadings. A checklist indicating where information is contained in the PUREX Storage Tunnels permit application documentation, in relation to the Washington State Department of Ecology guidance, is located in the Contents Section. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Wherever appropriate, the PUREX Storage Tunnels permit application documentation makes cross-reference to the General Information Portion, rather than duplicating text. Information provided in this PUREX Storage Tunnels permit application documentation is current as of April 1997.
Price, S.M.
Aluminum tunnel junction detector operation in an adiabatic demagnetization refrigerator
Superconducting tunnel junction detectors are being developed as both particle and X-ray detectors. Aluminum junctions are desirable for detectors because of their strong native oxide barriers, and because the small energy gap of aluminum is a good match to ballistic phonons generated by particle interactions in single crystals of silicon or other low acoustic-loss insulating crystals. Aluminum tunnel junction detectors must be operated near 0.1 T{sub C} which is 110 mK for aluminum. To operate detectors at these temperatures, we have developed adiabatic demagnetization refrigerators (ADRs) for the laboratory and prototype ADRs for space based operation. These cryogenic systems are simpler, more convenient and more portable than most dilution refrigerators. We have demonstrated that the magnetic field of the ADR need not compromise the performance of aluminum tunnel junctions. We have recently initiated a program to develop superconducting tunnel junctions (STJs) as high resolution X-ray detectors and low energy threshold particle detectors. This complements our existing program in which we are developing high resolution X-ray microcalorimeter detectors. One of our goals for both of these cryogenic detector development efforts is to observe X-ray emission from cosmic sources. This requires a refrigeration system that can operate under zero gravity space flight conditions. For the microcalorimeter project, temperatures of 100 mK and below are required to sufficiently reduce the heat capacity of the device. We have therefore developed an adiabatic demagnetization refrigerator (ADR) system which can be configured for space flight.
Labov, S.; Silver, E.; Le Gros, M. (Lawrence Livermore National Lab., CA (United States)); Bland, R.W.; Dickson, S.C.; Dignan, T.G.; Laws, K.; Johnson, R.T.; Simon, M.W.; Stricker, D.A.; Watson, R.M. (San Francisco State Univ., CA (United States)); Madden, N.; Landis, D. (Lawrence Berkeley Lab., CA (United States))
Analysis of different tunneling mechanisms of In{sub x}Ga{sub 1?x}As/AlGaAs tunnel junction light-emitting transistors
The electrical and optical characteristics of tunnel junction light-emitting transistors (TJLETs) with different indium mole fractions (x?=?5% and 2.5%) of the In{sub x}Ga{sub 1?x}As base-collector tunnel junctions have been investigated. Two electron tunneling mechanisms (photon-assisted or direct tunneling) provide additional currents to electrical output and resupply holes back to the base region, resulting in the upward slope of I-V curves and enhanced optical output under forward-active operation. The larger direct tunneling probability and stronger Franz-Keldysh absorption for 5% TJLET lead to higher collector current slope and less optical intensity enhancement when base-collector junction is under reverse-biased.
Wu, Cheng-Han [Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan (China); Wu, Chao-Hsin, E-mail: email@example.com [Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan (China); Graduate Institute of Photonics and Optoelectronics, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan (China)
Laser-driven relativistic tunneling from p-states
The tunneling ionization of an electron from a p-state in a highly charged ion in the relativistic regime is investigated in a linearly polarized strong laser field. In contrast to the case of an s-state, the tunneling ionization from the p-state is spin asymmetric. We have singled out two reasons for the spin asymmetry: first, the difference of the electron energy Zeeman splitting in the bound state and during tunneling, and second, the relativistic momentum shift along the laser propagation direction during the under-the barrier motion. Due to the latter, those states are predominantly ionized where the electron rotation is opposite to the electron relativistic shift during the under-the-barrier motion. We have investigated the dependence of the ionization rate on the laser intensity for different projections of the total angular momentum and identified the intensity parameter which governs this behaviour. The significant change of the ionization rate is originated from the different precession dynamics of the total angular momentum in the bound state at high and low intensities.
Michael Klaiber; Karen Z. Hatsagortsyan
A 233 km tunnel for lepton and hadron colliders
A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of e{sup +}e{sup -}, pp-bar , and {mu}{sup +}{mu}{sup -} collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV e{sup +}e{sup -} colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV e{sup +}e{sup -} collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV pp-bar collider uses the high intensity Fermilab p-bar source, exploits high cross sections for pp-bar production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.
Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T. [Dept. of Physics and Astronomy, University of Mississippi-Oxford, University, MS 38677 (United States)
Subbarrier fusion reactions and many-particle quantum tunneling
Low energy heavy-ion fusion reactions are governed by quantum tunneling through the Coulomb barrier formed by a strong cancellation of the repulsive Coulomb force with the attractive nuclear interaction between the colliding nuclei. Extensive experimental as well as theoretical studies have revealed that fusion reactions are strongly influenced by couplings of the relative motion of the colliding nuclei to several nuclear intrinsic motions. Heavy-ion subbarrier fusion reactions thus provide a good opportunity to address a general problem on quantum tunneling in the presence of couplings, which has been a popular subject in the past decades in many branches of physics and chemistry. Here we review theoretical aspects of heavy-ion subbarrier fusion reactions from the view point of quantum tunneling in systems with many degrees of freedom. Particular emphases are put on the coupled-channels approach to fusion reactions, and the barrier distribution representation for multi-channel penetrability. We also discuss an application of the barrier distribution method to elucidation of the mechanism of dissociative adsorption of H$_2$ melecules in surface science.
K. Hagino; N. Takigawa
Golden, CO. Sponsoring Org: USDOE Office of Energy Efficiency and Renewable Energy Solar Energy Technologies Office Country of Publication: United States Language: English...
MISTY ECHO Tunnel Dynamics Experiment--Data report: Volume 1; Yucca Mountain Site Characterization Project
Tunnel damage resulting from seismic loading is an important issue for the Yucca Mountain nuclear waste repository. The tunnel dynamics experiment was designed to obtain and document ground motions, permanent displacements, observable changes in fracture patterns, and visible damage at ground motion levels of interest to the Yucca Mountain Project. Even though the maximum free-field loading on this tunnel was 28 g, the damage observed was minor. Fielding details, data obtained, and supporting documentation are reported.
Phillips, J.S.; Luke, B.A.; Long, J.W.; Lee, J.G.
Facility Closure Report for T-Tunnel (U12t), Area 12, Nevada Test Site, Nevada
This Facility Closure Report (FCR) has been prepared to document the actions taken to permanently close the remaining accessible areas of U12t-Tunnel (T-Tunnel) in Area 12 of the Nevada Test Site (NTS). The closure of T-Tunnel was a prerequisite to transfer facility ownership from the Defense Threat Reduction Agency (DTRA) to the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Closure of the facility was accomplished with the cooperation and concurrence of both NNSA/NSO and the Nevada Division of Environmental Protection (NDEP). The purpose of this FCR is to document that the closure of T-Tunnel complied with the closure requirements specified in the Facility Closure Plan for N- and T-Tunnels Area 12, Nevada Test Site (Appendix D) and that the facility is ready for transfer to NNSA/NSO. The Facility Closure Plan (FCP) is provided in Appendix D. T-Tunnel is located approximately 42 miles north of Mercury in Area 12 of the NTS (Figure 1). Between 1970 and 1987, T-Tunnel was used for six Nuclear Weapons Effects Tests (NWETs). The tunnel was excavated horizontally into the volcanic tuffs of Rainier Mesa. The T-Tunnel complex consists of a main access drift with two NWET containment structures, a Gas Seal Plug (GSP), and a Gas Seal Door (GSD) (Figure 2). The T-Tunnel complex was mothballed in 1993 to preserve the tunnel for resumption of testing, should it happen in the future, to stop the discharge of tunnel effluent, and to prevent unauthorized access. This was accomplished by sealing the main drift GSD.
NSTec Environmental Restoration
The U.S. Department of Energy (DOE) is evaluating the Baker-Barry Tunnel as a potential GATEWAY Demonstrations project for deployment of solid-state lighting (SSL) technology. The National Park Service (NPS) views this project as a possible proving ground and template for implementation of light-emitting diode (LED) luminaires in other NPS tunnels, thereby expanding the estimated 40% energy savings from 132 MWh/yr for this tunnel to a much larger figure national
Influence of increased static pressure in MHD-channel of hypervelocity wind tunnel on its characteristics
One of the main weaknesses of available MHD gas acceleration wind tunnels which restricts their application for simulating vehicle re-entry flights and reproducing scramjet combustion chamber conditions is a relatively low static pressure in the channel (P{approximately}0.1 to 0.2 Atm). The possibility of increasing this pressure and the influence of the increased pressure on the MHD-accelerator characteristics are the subject of the present paper. It is shown that the main challenge is the necessity of increasing the total Lorentz force proportionally to the channel gas density at electrode current density not resulting in heat and electrical breakdown and the development of the side walls and interelectrode insulators designed for higher heat fluxes, q {approximately} 5 to 10 kw/cm{sup 2}. Some possible wall design versions are suggested. The influence of increased pressure is investigated using the Faraday - type MED channel at static pressures in the MHD channel from 0.2 to 1.0 Atm and total accelerating current I = 300 to 1,100 Amps when B=2.5T. Forty five electrodes are used in the MHD channel at maximum current density of 50 A/cm{sup 2}. The channel flow is calculated by applying the model of a gas in thermodynamic equilibrium. The influence of the increased pressure on electrodynamic (accelerator electrode voltages and currents, Hall voltage and current) and gasdynamic (distributions of static pressure, temperature, velocity, Mach numbers, etc., along the channel length) characteristics is evaluated. Some recommendations on the development of MHD channels for hypersonic wind tunnels designed for high pressure are suggested.
Alfyorov, V.I.; Rudakova, A.P.; Rukavets, V.P.; Shcherbakov, G.I. [Central Aerohydrodynamic Institute (TsAGI), Zhukovsky (Russian Federation)
High performance vertical tunneling diodes using graphene/hexagonal boron nitride/graphene hetero-structure
A tunneling rectifier prepared from vertically stacked two-dimensional (2D) materials composed of chemically doped graphene electrodes and hexagonal boron nitride (h-BN) tunneling barrier was demonstrated. The asymmetric chemical doping to graphene with linear dispersion property induces rectifying behavior effectively, by facilitating Fowler-Nordheim tunneling at high forward biases. It results in excellent diode performances of a hetero-structured graphene/h-BN/graphene tunneling diode, with an asymmetric factor exceeding 1000, a nonlinearity of ?40, and a peak sensitivity of ?12?V{sup ?1}, which are superior to contending metal-insulator-metal diodes, showing great potential for future flexible and transparent electronic devices.
Hwan Lee, Seung; Lee, Jia; Ho Ra, Chang; Liu, Xiaochi; Hwang, Euyheon [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Sup Choi, Min [Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Hee Choi, Jun [Frontier Research Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Yongin, Gyeonggi-do 446-711 (Korea, Republic of); Zhong, Jianqiang; Chen, Wei [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Jong Yoo, Won, E-mail: firstname.lastname@example.com [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)
E-Print Network 3.0 - alloy tunneling barrier Sample Search Results
through an insulating barrier with magnetic impurities O. Vvra,1,2, Summary: Josephson junction with a tunneling barrier formed by a paramagnetic insulator. We demonstrate......
GaAsSb-based heterojunction tunnel diodes for tandem solar cell interconnects
We report a new approach to tunnel junctions that employs a pseudomorphic GaAsSb layer to obtain a band alignment at a InGaAs or InAlAs p-n junction favorable for forward bias tunneling. Since the majority of the band offset between GaAsSb and InGaAs or InAlAs is in the valence band, when an GaAsSb layer is placed at an InGaAs or InAlAs p-n junction the tunneling distance is reduced and the tunneling current is increased. For all doping levels studied, the presence of the GaAsSb-layer enhanced the forward tunneling characteristics. In fact, in a InGaAs/GaAsSb tunnel diode a peak tunneling current sufficient for a 1000 sun intercell interconnect was achieved with p = 1.5{times}l0{sup 18} cm{sup -3} while a similarly doped all-InGaAs diode was rectifying. This approach affords a new degree of freedom in designing tunnel junctions for tandem solar cell interconnects. Previously only doping levels could be varied to control the tunneling properties. Our approach relaxes the doping requirements by employing a GaAsSb-based heterojunction.
Zolper, J.C.; Klem, J.F.; Plut, T.A.; Tigges, C.P.
Department of Mechanical and Nuclear Engineering Spring 2011 Wind Tunnel Automation Project
PENNSTATE Department of Mechanical and Nuclear Engineering Spring 2011 Wind Tunnel Automation Project Phase II - Automated Bike Turret Mount Overview SYNERGE LLC is a consulting company working
Demirel, Melik C.
Observation of diamond turned OFHC copper using Scanning Tunneling Microscopy
Diamond turned OFHC copper samples have been observed within the past few months using the Scanning Tunneling Microscope. Initial results have shown evidence of artifacts which may be used to better understand the diamond turning process. The STM`s high resolution capability and three dimensional data representation allows observation and study of surface features unobtainable with conventional profilometry systems. Also, the STM offers a better quantitative means by which to analyze surface structures than the SEM. This paper discusses findings on several diamond turned OFHC copper samples having different cutting conditions. Each sample has been cross referenced using STM and SEM.
Grigg, D.A.; Russell, P.E.; Dow, T.A.
Fabrication of a gated gallium arsenide heterostructure resonant tunneling diode
metallization process ivas required because separate potentials must be apphed to the top and base ol' the defined mesas. A potent&al is apphed to the top of the mesas to inject carriers for tunneling through the douhle barrier heterostructures A. rectifying... was a demetal/degrease cleanup process which re- moved any contamination that may have been nn the wal'er. This process ivas followed by deposition of AuGe/Ni on the ivafer's backside which ivill provide an ohmic contact after annealing. The backside...
Kinard, William Brian
Automatic signal processing of front monitor radar for tunneling machines
It is planned to install a front monitoring impulse radar on the surface of the rotating drill of tunneling machines in order to detect obstacles such as casing pipes of vertical borings. The conventional aperture synthesis technique can no more be applied to such cases because the radar image of a pipe dies not constituent a hyperbola as is the case for linear scanning radars. The authors have developed a special purpose signal processing algorithm with the aid of the discrete model fitting method, which can be used for any pattern of scanning. The details of the algorithm are presented together with the results of numerical simulations and test site experiments.
Sato, Toru [Kyoto Univ. (Japan). Dept. of Electronics and Communication] [Kyoto Univ. (Japan). Dept. of Electronics and Communication; Takeda, Kenya [NTT Co. Ltd., Chiba (Japan)] [NTT Co. Ltd., Chiba (Japan); Nagamatsu, Takashi [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)] [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Wakayama, Toshio [Mitsubishi Electric Corp., Kamakura, Kanagawa (Japan)] [Mitsubishi Electric Corp., Kamakura, Kanagawa (Japan); Kimura, Iwane [Osaka Inst. of Tech., Hirakata, Osaka (Japan)] [Osaka Inst. of Tech., Hirakata, Osaka (Japan); Shinbo, Tetsuya [Komatsu Co. Ltd., Kanagawa (Japan)] [Komatsu Co. Ltd., Kanagawa (Japan)
Ris-R-999(EN) Wind Tunnel Test of the RIS-1
coefficients and wake rake pressure measurements provided the total drag coefficient. Wind tunnel corrections of blades for stall regulated wind turbines with a Reynolds number betweenRis�-R-999(EN) Wind Tunnel Test of the RIS�-1 Airfoil Peter Fuglsang, Ioannis Antoniou, Christian
Wind Tunnel and Field Test of Three 2D Sonic Anemometers
Wind Tunnel and Field Test of Three 2D Sonic Anemometers Wiel Wauben R&D Information and Observation Technology, KNMI September 17, 2007 #12;#12;Wind Tunnel and Field Test of Three 2D Sonic.....................................................................................................1 2. Wind sensors
Stoffelen, Ad
Direct injection tunnel spectroscopy of a p-n junction Edward M. Likovich,1
Direct injection tunnel spectroscopy of a p-n junction Edward M. Likovich,1 Kasey J. Russell,1,a tunnel injection of electrons. In contrast to the metal-base transistor design of conventional ballistic the semiconductor before they scatter and thermal- ize to the chemical potential of the base layer. For systems
Russell, Kasey
Oxygen driven reconstruction dynamics of Ni,,977... measured by time-lapse scanning tunneling microscopy
Oxygen driven reconstruction dynamics of Ni,,977... measured by time-lapse scanning tunneling-lapse scanning tunneling microscopy STM has been used to observe the oxygen induced reconstruction behavior of Ni for the merging of steps in the presence of small amounts of adsorbed oxygen, less than 2% of a monolayer. Point
Sibener, Steven
The development of a wind tunnel facility for the study of V/STOL noise
An open-jet wind tunnel operating within an anechoic chamber was developed for the purpose of the study of V/STOL noise mechanisms. An existing low-speed conventional hard-walled wind tunnel was modified to operate as an ...
Widnall, S. E.
to the geo-engineers in order to devise safety measures suitable during construction of the tunnel of water and rock matrix heats the air in a tunnel that can make the working condition along. Hydropower generation has thus become a major source of power generation, especially in Himalayan region
Harinarayana, T.
Department of Mechanical and Nuclear Engineering Fall 2010 Wind Tunnel Automated Bicycle Adjustment System
PENN STATE Department of Mechanical and Nuclear Engineering Fall 2010 Wind Tunnel Automated Bicycle with the development of Aerofit's prototype portable wind tunnel used in the aerodynamic testing of bicycles was to automate this adjustment of the bicycle seat and aerobars in order to decrease the time for fitting each
Optical measurements of methyl group tunneling in molecular crystals: Temperature dependence of the nuclear spin conversion rate
) The tunneling methyl groups in dimethyl-s-tetrazine (DMST) doped single crystals of durene were investigated
Combined Experiment Phase 1. [Horizontal axis wind turbines: wind tunnel testing versus field testing
How does wind tunnel airfoil data differ from the airfoil performance on an operating horizontal axis wind turbine (HAWT) The National Renewable Energy laboratory has been conducting a comprehensive test program focused on answering this question and understanding the basic fluid mechanics of rotating HAWT stall aerodynamics. The basic approach was to instrument a wind rotor, using an airfoil that was well documented by wind tunnel tests, and measure operating pressure distributions on the rotating blade. Based an the integrated values of the pressure data, airfoil performance coefficients were obtained, and comparisons were made between the rotating data and the wind tunnel data. Care was taken to the aerodynamic and geometric differences between the rotating and the wind tunnel models. This is the first of two reports describing the Combined Experiment Program and its results. This Phase I report covers background information such as test setup and instrumentation. It also includes wind tunnel test results and roughness testing.
Butterfield, C.P.; Musial, W.P.; Simms, D.A.
Facility Closure Report for Tunnel U16a, Area 16, Nevada Test Site, Nevada
U16a is not listed in the Federal Facility Agreement and Consent Order. The closure of U16a was sponsored by the Defense Threat Reduction Agency (DTRA) and performed with the cooperation of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the Nevada Division of Environmental Protection. This report documents closure of this site as identified in the DTRA Fiscal Year 2008 Statement of Work, Task 6.3. Closure activities included: � Removing and disposing of a shack and its contents � Disposing of debris from within the shack and in the vicinity of the tunnel entrance � Verifying that the tunnel is empty � Welding screened covers over tunnel vent holes to limit access and allow ventilation � Constructing a full-tunnel cross-section fibercrete bulkhead to prevent access to the tunnel Field activities were conducted from July to August 2008.
Axial Ge/Si nanowire heterostructure tunnel FETs.
Axial Ge/Si heterostructure nanowires (NWs) allow energy band-edge engineering along the axis of the NW, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two significant advances in the area of heterostructure NWs and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure NWs with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these NWs for high-on currents and suppressed ambipolar behavior. Initial prototype devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a very high current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. Prior work on the synthesis of Ge/Si axial NW heterostructures through the VLS mechanism have resulted in axial Si/Si{sub 1-x}Ge{sub x} NW heterostructures with x{sub max} {approx} 0.3, and more recently 100% composition modulation was achieved with a solid growth catalyst. In this latter case, the thickness of the heterostructure cannot exceed few atomic layers due to the slow axial growth rate and concurrent radial deposition on the NW sidewalls leading to a mixture of axial and radial deposition, which imposes a big challenge for fabricating useful devices form these NWs in the near future. Here, we report the VLS growth of 100% doping and composition modulated axial Ge/Si heterostructure NWs with lengths appropriate for device fabrication by devising a growth procedure that eliminates Au diffusion on the NW sidewalls and minimizes random kinking in the heterostructure NWs as deduced from detailed microscopy analysis. Fig. 1 a shows a cross-sectional SEM image of epitaxial Ge/Si axial NW heterostructures grown on a Ge(111) surface. The interface abruptness in these Ge/Si heterostructure NWs is of the order of the NW diameter. Some of these NWs develop a crystallographic kink that is {approx}20{sup o} off the <111> axis at about 300 nm away from the Ge/Si interface. This provides a natural marker for placing the gate contact electrodes and gate metal at appropriate location for desired high-on current and reduced ambipolarity as shown in Fig. 2. The 1D heterostructures allow band-edge engineering in the transport direction, not easily accessible in planar devices, providing an additional degree of freedom for designing tunnel FETs (TFETs). For instance, a Ge tunnel source can be used for efficient electron/hole tunneling and a Si drain can be used for reduced back-tunneling and ambipolar behavior. Interface abruptness on the other hand (particularly for doping) imposes challenges in these structures and others for realizing high performance TFETs in p-i-n junctions. Since the metal-semiconductor contacts provide a sharp interface with band-edge control, we use properly designed Schottky contacts (aided by 3D Silvaco simulations) as the tunnel barriers both at the source and drain and utilize the asymmetry in the Ge/Si channel bandgap to reduce ambipolar transport behavior generally observed in TFETs. Fig. 3 shows the room-temperature transfer curves of a Ge/Si heterostructure TFET (H-TFET) for different V{sub DS} values showing a maximum on-current of {approx}7 {micro}A, {approx}170 mV/decade inverse subthreshold slope and 5 orders of magnitude I{sub on}/I{sub off} ratios for all V{sub DS} biases considered here. This high on-current value is {approx}1750 X higher than that obtained with Si p-i-n{sup +} NW TFETs and {approx}35 X higher than that obtained with CNT TFET. The I{sub on}/I{sub off} ratio and inverse subthreshold slope compare favorably to that of Si {approx} 10{sup 3} I{sub on}/I{sub off} and {approx} 800 mV/decade SS{sup -1} but lags behind those of CNT TFET due to poor PECVD nitride gate oxide quality ({var_epsilon}{sub r} {approx} 3-4). The asymmetry in the Schottky barrier heights used here eliminates the stringent requirements of abrupt doped interfaces used in p-i-n based TFETs, which is hard to achieve both in thin-film and
Dayeh, Shadi A. (Los Alamos National Laboratory); Gin, Aaron V.; Huang, Jian Yu; Picraux, Samuel Thomas (Los Alamos National Laboratory)
Value engineering the construction of long tunnels in the dolomites of northern Illinois, United States of America
Fermi National Accelerator Laboratory (Fermilab), a high-energy physics laboratory operated by the Universities Research Association for the US Department of Energy, is developing plans for the construction of accelerator tunnels. The accelerator designs vary as a function of particles accelerated, technologies used and energies targeted. However, all accelerators require the excavation of long tunnels, up to 700 km in length, and tunnel costs represent a major portion of project budgets. This paper documents the findings of two studies undertaken to identify tunnel cost-drivers and outlines steps taken to initiate the ''value engineering'' of the tunnels.
Laughton, Christopher; /Fermilab
Ferroelectric modulation on resonant tunneling through perovskite double-barriers
The negative differential resistance (NDR) due to resonance tunneling is achieved at room temperature in perovskite double-barrier heterostructures composed of a 10 unit-cell-thick SrTiO{sub 3} quantum well sandwiched in two 10 unit-cell-thick LaAlO{sub 3} barriers. The NDR occurs at 1.2?V and does not change with voltage cycling. When the paraelectric SrTiO{sub 3} quantum well is replaced by a ferroelectric BaTiO{sub 3}, the onset of the NDR can be modulated by polarization switching in the ultrathin BaTiO{sub 3}. A polarization pointing to the collector lowers the NDR voltage but a polarization pointing to the emitter increases it. The shift of the NDR voltage is ascribed to reversal of the extra electric field in the quantum well due to the polarization switching.
Du, Ruifang; Qiu, Xiangbiao; Li, Aidong; Wu, Di, E-mail: firstname.lastname@example.com [National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093 (China)
Relativistic tunneling picture of electron-positron pair creation
The common tunneling picture of electron-positron pair creation in a strong electric field is generalized to pair creation in combined crossed electric and magnetic fields. This enhanced picture, being symmetric for electrons and positrons, is formulated in a gauge-invariant and Lorentz-invariant manner for quasistatic fields. It may be used to infer qualitative features of the pair creation process. In particular, it allows for an intuitive interpretation of how the presence of a magnetic field modifies and, in particular cases, even enhances pair creation. The creation of electrons and positrons from the vacuum may be assisted by an energetic photon, which can also be incorporated into this picture of pair creation.
Anton W�llert; Michael Klaiber; Heiko Bauke; Christoph H. Keitel
High energy storage capacitor by embedding tunneling nano-structures
In an All-Electron Battery (AEB), inclusions embedded in an active region between two electrodes of a capacitor provide enhanced energy storage. Electrons can tunnel to/from and/or between the inclusions, thereby increasing the charge storage density relative to a conventional capacitor. One or more barrier layers is present in an AEB to block DC current flow through the device. The AEB effect can be enhanced by using multi-layer active regions having inclusion layers with the inclusions separated by spacer layers that don't have the inclusions. The use of cylindrical geometry or wrap around electrodes and/or barrier layers in a planar geometry can enhance the basic AEB effect. Other physical effects that can be employed in connection with the AEB effect are excited state energy storage, and formation of a Bose-Einstein condensate (BEC).
Holme, Timothy P; Prinz, Friedrich B; Van Stockum, Philip B
Heat engine driven by three-body photon tunneling
Near-field heat engines are devices that convert the evanescent thermal field supported by a primary source into usable mechanical energy. By analyzing the thermodynamic performance of three-body near-field heat engines, we demonstrate that the power they supply can be substantially larger than that of two-body systems, showing so their strong potential for energy harvesting. Theoretical limits for energy and entropy fluxes in three-body systems are discussed and compared with their corresponding two-body counterparts. Such considerations confirm that the thermodynamic availability in energy-conversion processes driven by three-body photon tunneling can exceed the thermodynamic availability in two-body systems.
Latella, Ivan; Rubi, J Miguel; Biehs, Svend-Age; Ben-Abdallah, Philippe
Axial Ge/Si nanowire heterostructure tunnel FETs
The vapor-liquid-solid (VLS) growth of semiconductor nanowires allows doping and composition modulation along their axis and the realization of axial 1 D heterostructures. This provides additional flexibility in energy band-edge engineering along the transport direction which is difficult to attain by planar materials growth and processing techniques. We report here on the design, growth, fabrication, and characterization of asymmetric heterostructure tunnel field-effect transistors (HTFETs) based on 100% compositionally modulated Si/Ge axial NWs for high on-current operation and low ambipolar transport behavior. We discuss the optimization of band-offsets and Schottky barrier heights for high performance HTFETs and issues surrounding their experimental realization. Our HTFET devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a measured current drive exceeding 100 {mu}A/{mu}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios.
Picraux, Sanuel T [Los Alamos National Laboratory; Daych, Shadi A [Los Alamos National Laboratory
Thermal spin-transfer torque in magnetic tunnel junctions (invited)
The thermal spin-transfer torque (TSTT) is an effect to switch the magnetic free layer in a magnetic tunnel junction by a temperature gradient only. We present ab initio calculations of the TSTT. In particular, we discuss the influence of magnetic layer composition by considering Fe{sub x}Co{sub 1�x} alloys. Further, we compare the TSTT to the bias voltage driven STT and discuss the requirements for a possible thermal switching. For example, only for very thin barriers of 3 monolayers MgO, a thermal switching is imaginable. However, even for such a thin barrier, the TSTT is still too small for switching at the moment and further optimization is needed. In particular, the TSTT strongly depends on the composition of the ferromagnetic layer. In our current study, it turns out that at the chosen thickness of the ferromagnetic layer, pure Fe gives the highest thermal spin-transfer torque.
Heiliger, Christian, E-mail: firstname.lastname@example.com; Franz, C.; Czerner, Michael [I. Physikalisches Institut, Justus Liebig University, Giessen (Germany)
Theory of multiphoton and tunnel ionization in a bichromatic field
The imaginary-time method [6, 7] is used to calculate the multiphoton and tunnel ionization probabilities for atoms in a laser radiation field part of which is converted into the second harmonic. We assume that the first harmonic has a linear or elliptical polarization and the second harmonic is polarized linearly, with its polarization vector making an arbitrary angle with that of the first harmonic. The mean momentum of the photoelectrons knocked out from atoms is shown to depend on the phase shift between the first and second harmonics and their mutual polarization and to be identically equal to zero for a monochromatic field. An important difference between the case of elliptical polarization and the case of linear polarization of both harmonics is the absence of conditions under which the conditions for dominance of one of the two generation mechanisms considered here can be identified during the generation of terahertz radiation from the region of optical breakdown in a gas.
Bagulov, D. S., E-mail: firstname.lastname@example.com [Novosibirsk State University (Russian Federation); Kotelnikov, I. A., E-mail: email@example.com [Russian Academy of Sciences, Siberian Branch, Budger Institute of Nuclear Physics (Russian Federation)
Hawking radiation as tunneling from charged black holes in 0A string theory
There has been much work on explaining Hawking radiation as a quantum tunneling process through horizons. Basically, this intuitive picture requires the calculation of the imaginary part of the action for outgoing particle. And two ways are known for achieving this goal: the null-geodesic method and the Hamilton-Jacobi method. We apply these methods to the charged black holes in 2D dilaton gravity which is originated from the low energy effective theory of type 0A string theory. We derive the correct Hawking temperature of the black holes including the effect of the back reaction of the radiation, and obtain the entropy by using the 1st law of black hole thermodynamics. For fixed-charge ensemble, the 0A black holes are free of phase transition and thermodynamically stable regardless of mass-charge ratio. We show this by interpreting the back reaction term as the inverse of the heat capacity of the black holes. Finally, the possibility of the phase transition in the fixed-potential ensemble is discussed.
Hongbin Kim
Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy
We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.
Oberbeck, Lars [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); TOTAL Marketing Services, New Energies, La D�fense 10, 92069 Paris La D�fense Cedex (France); Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y., E-mail: firstname.lastname@example.com, E-mail: email@example.com [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schofield, Steven R. [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Physics and Astronomy, UCL, London WC1E 6BT (United Kingdom); Curson, Neil J., E-mail: email@example.com, E-mail: email@example.com [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Electronic and Electrical Engineering, UCL, London WC1E 7JE (United Kingdom)
Giant intrinsic tunnel magnetoresistance in manganite thin films etched with antidot arrays
Huge intrinsic tunnel magnetoresistance effects at low field are demonstrated in macroscopic La{sub 0.33}Pr{sub 0.34}Ca{sub 0.33}MnO{sub 3} thin films etched with periodic antidot arrays, and a highest magnetoresistance ratio (about 1600%) is achieved at 58?K. Such giant tunnel magnetoresistance effect might originate from delicate phase separation and coherent transport under the applied periodic spatial confinement. Strong transport fluctuation is also revealed in such systems due to phase competition. Our findings pave a way to realize tunnel magnetoresistance devices based on electronically phase separated materials with spatial modulations.
Li, Hui; Li, Lin; Li, Long; Liang, Haixing; Cheng, Long; Zhai, Xiaofang [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Zeng, Changgan, E-mail: firstname.lastname@example.com [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
The effect of environmental coupling on tunneling of quasiparticles in Josephson junctions
We study quasiparticle tunneling in Josephson tunnel junctions embedded in an electromagnetic environment. We identify tunneling processes that transfer electrical charge and couple to the environment in a way similar to that of normal electrons, and processes that mix electrons and holes and are thus creating charge superpositions. The latter are sensitive to the phase difference between the superconductor and are thus limited by phase diffusion even at zero temperature. We show that the environmental coupling is suppressed in many environments, thus leading to lower quasiparticle decay rates and thus better superconductor qubit coherence than previously expected. Our approach is nonperturbative in the environmental coupling strength.
Mohammad H. Ansari; Frank K. Wilhelm; Urbasi Sinha; Aninda Sinha
Elimination of two level fluctuators in superconducting quantum bits by an epitaxial tunnel barrier
Quantum computing based on Josephson junction technology is considered promising due to its scalable architecture. However, decoherence is a major obstacle. Here, we report evidence for improved Josephson quantum bits (qubits) using a single-crystal Al{sub 2}O{sub 3} tunnel barrier. We have found an {approx}80% reduction in the density of the spectral splittings that indicate the existence of two-level fluctators (TLFs) in amorphous tunnel barriers. The residual {approx}20% TLFs can be attributed to interfacial effects that may be further reduced by different electrode materials. These results show that decoherence sources in the tunnel barrier of Josephson qubits can be identified and eliminated.
Oh, Seongshik [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States); Cicak, Katarina; Kline, Jeffrey S.; Sillanpaeae, Mika A.; Osborn, Kevin D.; Whittaker, Jed D.; Simmonds, Raymond W.; Pappas, David P. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)
Direct Observation of Tunneling and Nonlinear Self-Trapping in a Single Bosonic Josephson Junction
We report on the first realization of a single bosonic Josephson junction, implemented by two weakly linked Bose-Einstein condensates in a double-well potential. In order to fully investigate the nonlinear tunneling dynamics we measure the density distribution in situ and deduce the evolution of the relative phase between the two condensates from interference fringes. Our results verify the predicted nonlinear generalization of tunneling oscillations in superconducting and superfluid Josephson junctions. Additionally, we confirm a novel nonlinear effect known as macroscopic quantum self-trapping, which leads to the inhibition of large amplitude tunneling oscillations.
Albiez, Michael; Gati, Rudolf; Foelling, Jonas; Hunsmann, Stefan; Oberthaler, Markus K. [Kirchhoff-Institut fuer Physik, Universitaet Heidelberg, Im Neuenheimer Feld 227, D-69120 Heidelberg (Germany); Cristiani, Matteo [CNR-INFM, Dipartimento di Fisica E. Fermi, Universita di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa (Italy)
Direct space-time observation of pulse tunneling in an electromagnetic band gap
We present space-time-resolved measurements of electromagnetic pulses tunneling through a coaxial electromagnetic band gap structure. The results show that during the tunneling process the field distribution inside the barrier is an exponentially decaying standing wave whose amplitude increases and decreases as it slowly follows the temporal evolution of the input pulse. At no time is a pulse maximum found inside the barrier, and hence the transmitted peak is not the incident peak that has propagated to the exit. The results support the quasistatic interpretation of tunneling dynamics and confirm that the group delay is not the traversal time of the input pulse peak.
Doiron, Serge; Hache, Alain [Department de physique et d'astronomie, Universite de Moncton, Moncton, New Brunswick, E1A 3E9 (Canada); Winful, Herbert G. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States)
A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability
We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d{sub 31} coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.
Wang, Qi; Wang, Junting; Lu, Qingyou, E-mail: firstname.lastname@example.com [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China) [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China); Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hou, Yubin [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China)] [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China)
Propeller design optimization for tunnel bow thrusters in the bollard pull condition
Tunnel bow thrusters are often used by large ships to provide low-speed lateral maneuverability when docking. Required to provide high thrust while essentially at a standstill, the design point for these thrusters is the ...
Wilkins, James R., IV
Tunnel determinants from spectral zeta functions. Instanton effects in quantum mechanics
In this paper we develop an spectral zeta function regularization procedure on the determinants of instanton fluctuation operators that describe the semi-classical order of tunnel effects between degenerate vacua.
Izquierdo, A. Alonso [Departamento de Matematica Aplicada and IUFFyM, Universidad de Salamanca (Spain); Guilarte, J. Mateos [Departamento de Fisica Fundamental and IUFFyM, Universidad de Salamanca (Spain)
Earth pressure balance (EPB) tunneling induced settlements in the Tren Urbano Project, Rio Piedras, Puerto Rico
Underground construction of the Rio Piedras section of the Tren Urbano project involved the construction of twin tunnels (6.3m diameter) with Earth Pressure Balance machines in weathered alluvial soil. The depth of the ...
Abrams, Alejandro J
Evaluation of analytical methods to interpret ground deformations due to soft ground tunneling
An in depth study was undertaken to evaluate the effectiveness of analytical solutions in describing ground movements induced by soft ground tunneling. The analytical solutions that were examined consider both isotropic ...
Zymnis, Despina M
Wind Tunnel and Flight Testing of Active Flow Control on a UAV
Active flow control has been extensively explored in wind tunnel studies but successful in-flight implementation of an active flow control technology still remains a challenge. This thesis presents implementation of active flow control technology...
Babbar, Yogesh
Coherence of resonant-tunneling transport in terahertz quantum-cascade lasers
We develop simple density-matrix models to describe the role of coherence in resonant-tunneling (RT) transport of quantum-cascade lasers (QCLs). Specifically, we investigate the effects of coherent coupling between the ...
Kumar, Sushil
Wind Tunnel Tests of Parabolic Trough Solar Collectors: March 2001--August 2003
Conducted extensive wind-tunnel tests on parabolic trough solar collectors to determine practical wind loads applicable to structural design for stress and deformation, and local component design for concentrator reflectors.
Hosoya, N.; Peterka, J. A.; Gee, R. C.; Kearney, D.
Investigation of the tunneling emitter bipolar transistor as spin-injector into silicon
In this thesis is discussed the tunneling emitter bipolar transistor as a possible spin-injector into silicon. The transistor has a metallic emitter which as a spin-injector will be a ferromagnet. Spin-polarized electrons ...
Van Veenhuizen, Marc Julien
Scanning tunneling microscopy investigation of the TiO2 anatase ,,101... surface Wilhelm Hebenstreit,1
of tunneling sites in STM. Titanium dioxide (TiO2) is a versatile material that finds uses as a promoter. Fourfold-coordinated Ti atoms at step edges are preferred adsorption sites and allow the identification
Diebold, Ulrike
Resonant escape over an oscillating barrier in underdamped Josephson tunnel junctions
The escape from a metastable state over an oscillating barrier of an underdamped Josephson tunnel junction has been experimentally investigated with oscillation frequency well separated from the plasma frequency of the ...
Han, Siyuan; Yu, Yang
Common-path interference and oscillatory Zener tunneling in bilayer graphene p-n junctions
Interference and tunneling are two signature quantum effects that are often perceived as the yin and yang of quantum mechanics: a particle simultaneously propagating along several distinct classical paths versus a particle ...
Nandkishore, Rahul Mahajan
Scanning tunneling microscopic studies of SiO2 thin film supported metal nano-clusters
This dissertation is focused on understanding heterogeneous metal catalysts supported on oxides using a model catalyst system of SiO2 thin film supported metal nano-clusters. The primary technique applied to this study is scanning tunneling...
Min, Byoung Koun
Tunnel Boring Machine (TBM) performance in Singapore's Mass Rapid Transit (MRT) system
Singapore's Mass Rapid Transit (MRT) network is one of the largest public works projects undertaken by the Singapore government. This thesis summarizes and evaluates the performance of Tunnel Boring Machine (TBM) construction ...
Chong, Wanling
Wind Tunnel Blockage Corrections: An Application to Vertical-Axis Wind Turbines.
?? An investigation into wake and solid blockage effects of Vertical-Axis Wind Turbines (VAWTs) in closed test-section wind tunnel testing is described. Static wall pressures� (more)
Ross, Ian Jonathan
Development of a Digital Controller for a Vertical Wind Tunnel (VWT) Prototype to Mitigate Ball Fluctuations
The objective of this research was to mitigate fluctuations of a levitated ping pong ball within a vertical wind tunnel (VWT) prototype. This was made possible by remodeling the VWT system with its inherent nonlinear characteristics instead...
Silva, Ramon A.
An Updated Procedure for Tare and Interference Wind Tunnel Testing of Strut-Mounted Models
to the presence of wind tunnel walls. The standard correction procedure adjusts for the presence of these boundaries using approximations based on linear potential flow theory. Separately,tare and interference removal involves the linear subtraction of mounting...
Kutz, Douglas M
Fire modeling for Building 221-T - T Plant Canyon Deck and Railroad Tunnel
This report was prepared by Hughes Associates, Inc. to document the results of fire models for building 221-T Canyon Deck and Railroad Tunnel. Backup data is contained in document No. WHC-SD-CP-ANAL-010, Rev. 0.
Oar, D.L.
Shock-Dispersed-Fuel Charges: Combustion in Chambers and Tunnels
In previous studies we have investigated after-burning effects of a fuel-rich explosive (TNT). In that case the detonation only releases about 30% of the available energy, but generates a hot cloud of fuel that can burn in the ambient air, thus evoking an additional energy release that is distributed in space and time. The current series of small-scale experiments can be looked upon as a natural generalization of this mechanism: a booster charge disperses a (non-explosive) fuel, provides mixing with air and, by means of the hot detonation products, the energy to ignite the fuel. The current version of our miniature Shock-Dispersed-Fuel (SDF) charges consists of a spherical booster charge of 0.5 g PETN, embedded in a paper cylinder of approximately 2.2 cm, which is filled with powdered fuel compositions. The main compositions studied up to now contain aluminum flakes, hydrocarbon powders like polyethylene or hexosen (sucrose) and/or carbon particles. These charges were studied in four different chambers: two cylindrical vessels of 6.6-1 and 40.5-1 volume with a height-to-diameter ratio of approximately 1, a rectangular chamber of 41 (10.5 x 10.5 x 38.6 cm) and a 299.6 cm long tunnel model with a cross section of 8 x 8 cm (volume 19.21) closed at both ends.
Neuwald, P; Reichenbach, H; Kuhl, A L
Potential for tunneling based on rock and soil melting. Abstracts
The rock-melting drill was invented at Los Alamos Scientific Laboratory in 1960. Electrically heated, laboratory-scale drills were subsequently shown to penetrate igneous rocks at usefully high rates, with moderate power consumptions. The development of compact nuclear reactors and of heat pipes now makes possible the extension of this technology to much larger melting penetrators, potentially capable of producing holes up to several meters in diameter and several tens of kilometers long or deep. Development of a rapid, versatile, economical method of boring large, long shafts and tunnels offers solutions to many of man's most urgent ecological, scientific, raw-materials, and energy-supply problems. A melting method appears to be the most promising and flexible means of producing such holes. It is relatively insensitive to the composition, hardness, structure, and temperature of the rock, and offers the possibilities of producing self-supporting, glass-lined holes in almost any formation and (using a technique called lithofracturing) of eliminating the debris-removal problem by forcing molten rock into cracks created in the bore wall. Large rock-melting penetrators, called Electric Subterrenes or Nuclear Subterrenes according to the energy source used, are discussed in this report, together with problems anticipated in their development. It is concluded that this development is within the grasp of present technology.
Rowley, J.C.
Emission of Microwave Photon Pairs by a Tunnel Junction
Generation and control of non-classical electromagnetic fields is of crucial importance for quantum information physics. While usual methods for the production of such fields rely on a non-linearity (of a crystal, a Josephson junction, etc.), a recent experiment performed on a normal conductor, a tunnel junction under microwave irradiation, has unveiled an alternative: the use of electron shot noise in a quantum conductor\\cite{PAN_squeezing}. Here we show that such a device can emit \\emph{pairs of microwave photons} of different frequencies with a rate as high as that of superconducting Josephson junctions\\cite{Flurin}. This results in intensity fluctuations of the photon field at two different frequencies being correlated below the photon shot noise,i.e. two-mode amplitude squeezing. Our experiment constitutes a fundamental step towards the understanding of electronic noise in terms of quantum optics, and shows that even a normal conductor could be used as a resource for quantum information processing.
Jean-Charles Forgues; Christian Lupien; Bertrand Reulet
Photon-assisted tunneling with non-classical light
Among the most exciting recent advances in the field of superconducting quantum circuits is the ability to coherently couple microwave photons in low-loss cavities to quantum electronic conductors (e.g.~semiconductor quantum dots or carbon nanotubes). These hybrid quantum systems hold great promise for quantum information processing applications; even more strikingly, they enable exploration of completely new physical regimes. Here we study theoretically the new physics emerging when a quantum electronic conductor is exposed to non-classical microwaves (e.g.~squeezed states, Fock states). We study this interplay in the experimentally-relevant situation where a superconducting microwave cavity is coupled to a conductor in the tunneling regime. We find the quantum conductor acts as a non-trivial probe of the microwave state; in particular, the emission and absorption of photons by the conductor is characterized by a non-positive definite quasi-probability distribution. This negativity has a direct influence on the conductance of the conductor.
J. -R. Souquet; M. J. Woolley; Julien Gabelli; Pascal Simon; Aashish A. Clerk
Preliminary studies of tunnel interface response modeling using test data from underground storage facilities.
In attempting to detect and map out underground facilities, whether they be large-scale hardened deeply-buried targets (HDBT's) or small-scale tunnels for clandestine border or perimeter crossing, seismic imaging using reflections from the tunnel interface has been seen as one of the better ways to both detect and delineate tunnels from the surface. The large seismic impedance contrast at the tunnel/rock boundary should provide a strong, distinguishable seismic response, but in practice, such strong indicators are often lacking. One explanation for the lack of a good seismic reflection at such a strong contrast boundary is that the damage caused by the tunneling itself creates a zone of altered seismic properties that significantly changes the nature of this boundary. This report examines existing geomechanical data that define the extent of an excavation damage zone around underground tunnels, and the potential impact on rock properties such as P-wave and S-wave velocities. The data presented from this report are associated with sites used for the development of underground repositories for the disposal of radioactive waste; these sites have been excavated in volcanic tuff (Yucca Mountain) and granite (HRL in Sweden, URL in Canada). Using the data from Yucca Mountain, a numerical simulation effort was undertaken to evaluate the effects of the damage zone on seismic responses. Calculations were performed using the parallelized version of the time-domain finitedifference seismic wave propagation code developed in the Geophysics Department at Sandia National Laboratories. From these numerical simulations, the damage zone does not have a significant effect upon the tunnel response, either for a purely elastic case or an anelastic case. However, what was discovered is that the largest responses are not true reflections, but rather reradiated Stoneley waves generated as the air/earth interface of the tunnel. Because of this, data processed in the usual way may not correctly image the tunnel. This report represents a preliminary step in the development of a methodology to convert numerical predictions of rock properties to an estimation of the extent of rock damage around an underground facility and its corresponding seismic velocity, and the corresponding application to design a testing methodology for tunnel detection.
Sobolik, Steven Ronald; Bartel, Lewis Clark
Performance limits of tunnel transistors based on mono-layer transition-metal dichalcogenides
Performance limits of tunnel field-effect transistors based on mono-layer transition metal dichalcogenides are investigated through numerical quantum mechanical simulations. The atomic mono-layer nature of the devices results in a much smaller natural length ?, leading to much larger electric field inside the tunneling diodes. As a result, the inter-band tunneling currents are found to be very high as long as ultra-thin high-k gate dielectric is possible. The highest on-state driving current is found to be close to 600??A/?m at V{sub g}?=?V{sub d}?=?0.5?V when 2?nm thin HfO{sub 2} layer is used for gate dielectric, outperforming most of the conventional semiconductor tunnel transistors. In the five simulated transition-metal dichalcogenides, mono-layer WSe{sub 2} based tunnel field-effect transistor shows the best potential. Deep analysis reveals that there is plenty room to further enhance the device performance by either geometry, alloy, or strain engineering on these mono-layer materials.
Jiang, Xiang-Wei, E-mail: firstname.lastname@example.com; Li, Shu-Shen [State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
Thermal Creation of Electron Spin Polarization in n-Type Silicon
Conversion of heat into a spin-current in electron doped silicon can offer a promising path for spin-caloritronics. Here we create an electron spin polarization in the conduction band of n-type silicon by producing a temperature gradient across a ferromagnetic tunnel contact. The substrate heating experiments induce a large spin signal of 95 $\\mu$V, corresponding to 0.54 meV spin-splitting in the conduction band of n-type silicon by Seebeck spin tunneling mechanism. The thermal origin of the spin injection has been confirmed by the quadratic scaling of the spin signal with the Joule heating current and linear dependence with the heating power.
Andr� Dankert; Saroj P. Dash
Thermal creation of electron spin polarization in n-type silicon
Conversion of heat into a spin-current in electron doped silicon can offer a promising path for spin-caloritronics. Here, we create an electron spin polarization in the conduction band of n-type silicon by producing a temperature gradient across a ferromagnetic tunnel contact. The substrate heating experiments induce a large spin signal of 95??V, corresponding to 0.54?meV spin-splitting in the conduction band of n-type silicon by Seebeck spin tunneling mechanism. The thermal origin of the spin injection has been confirmed by the quadratic scaling of the spin signal with the Joule heating current and linear dependence with the heating power.
Dankert, Andr�, E-mail: email@example.com; Dash, Saroj P., E-mail: firstname.lastname@example.com [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 G�teborg (Sweden)
New Hypersonic Shock Tunnel at the Laboratory of Aerothermodynamics and Hypersonics Prof. Henry T. Nagamatsu
The new 0.60-m. nozzle exit diameter hypersonic shock tunnel was designed to study advanced air-breathing propulsion system such as supersonic combustion and/or laser technologies. In addition, it may be used for hypersonic flow studies and investigations of the electromagnetic (laser) energy addition for flow control. This new hypersonic shock tunnel was designed and installed at the Laboratory for of Aerothermodynamics and Hypersonics Prof. Henry T. Nagamatsu, IEAv-CTA, Brazil. The design of the tunnel enables relatively long test times, 2-10 milliseconds, suitable for the experiments performed at the laboratory. Free stream Mach numbers ranging from 6 to 25 can be produced and stagnation pressures and temperatures up to 360 atm. and up to 9,000 K, respectively, can be generated. Shadowgraph and schlieren optical techniques will be used for flow visualization.
Toro, P. G. P.; Minucci, M. A. S.; Chanes, J. B. Jr; Oliveira, A. C.; Gomes, F. A. A.; Myrabo, L. N.; Nagamatsu, Henry T. [Laboratory of Aerothermodynamics and Hypersonics. Institute for Advanced Studies. IEAv-CTA. Rod. dos Tamoios km 5.5. Putim. Sao Jose dos Campos-SP 12228-001 (Brazil); Department of Mechanical, Aerospace, and Nuclear Engineering. Rensselaer Polytechnic Institute (RPI), Troy, NY, 12180-3590 (United States)
Intermediate-band photosensitive device with quantum dots having tunneling barrier embedded in organic matrix
A plurality of quantum dots each have a shell. The quantum dots are embedded in an organic matrix. At least the quantum dots and the organic matrix are photoconductive semiconductors. The shell of each quantum dot is arranged as a tunneling barrier to require a charge carrier (an electron or a hole) at a base of the tunneling barrier in the organic matrix to perform quantum mechanical tunneling to reach the respective quantum dot. A first quantum state in each quantum dot is between a lowest unoccupied molecular orbital (LUMO) and a highest occupied molecular orbital (HOMO) of the organic matrix. Wave functions of the first quantum state of the plurality of quantum dots may overlap to form an intermediate band.
Forrest, Stephen R. (Ann Arbor, MI)
Giant amplification of tunnel magnetoresistance in a molecular junction: Molecular spin-valve transistor
Amplification of tunnel magnetoresistance by gate field in a molecular junction is the most important requirement for the development of a molecular spin valve transistor. Herein, we predict a giant amplification of tunnel magnetoresistance in a single molecular spin valve junction, which consists of Ru-bis-terpyridine molecule as a spacer between two ferromagnetic nickel contacts. Based on the first-principles quantum transport approach, we show that a modest change in the gate field that is experimentally accessible can lead to a substantial amplification (320%) of tunnel magnetoresistance. The origin of such large amplification is attributed to the spin dependent modification of orbitals at the molecule-lead interface and the resultant Stark effect induced shift in channel position with respect to the Fermi energy.
Dhungana, Kamal B.; Pati, Ranjit, E-mail: firstname.lastname@example.com [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States)
Antenna-coupled Photon Emission from hexagonal Boron Nitride Tunnel Junctions
The ultrafast conversion of electrical to optical signals at the nanoscale is of fundamental interest for data processing, telecommunication and optical interconnects. However, the modulation bandwidths of semiconductor LEDs are limited by the spontaneous recombination rate of electron-hole pairs and the footprint of electrically-driven ultrafast lasers is too large for practical on-chip integration. A metal-insulator-metal (MIM) tunnel junction approaches the ultimate size limit of electronic devices and its operating speed is fundamentally limited only by the tunneling time. Here we study the conversion of electron energy - localized in vertical gold-h-BN-gold tunnel junctions - into free space photons, mediated by resonant slot antennas. Optical antennas efficiently bridge the size-mismatch between nanoscale volumes and far-field radiation and strongly enhance the electron-photon conversion efficiency. We achieve polarized, directional and resonantly enhanced light emission from inelastic electron tunnelin...
Parzefall, Markus; Jain, Achint; Watanabe, Kenji; Taniguchi, Takashi; Novotny, Lukas
Large-scale fabrication of BN tunnel barriers for graphene spintronics
We have fabricated graphene spin-valve devices utilizing scalable materials made from chemical vapor deposition (CVD). Both the spin-transporting graphene and the tunnel barrier material are CVD-grown. The tunnel barrier is realized by Hexagonal boron nitride, used either as a monolayer or bilayer and placed over the graphene. Spin transport experiments were performed using ferromagnetic contacts deposited onto the barrier. We find that spin injection is still greatly suppressed in devices with a monolayer tunneling barrier due to resistance mismatch. This is, however, not the case for devices with bilayer barriers. For those devices, a spin relaxation time of ?260 ps intrinsic to the CVD graphene material is deduced. This time scale is comparable to those reported for exfoliated graphene, suggesting that this CVD approach is promising for spintronic applications which require scalable materials.
Fu, Wangyang; Makk, P�ter; Maurand, Romain; Br�uninger, Matthias; Sch�nenberger, Christian [Department of Physics, University of Basel, Basel (Switzerland)
Tunneling dynamics of bosonic Josephson junctions assisted by a cavity field
We study the interplay between the dynamics of a Bose-Einstein condensate in a double-well potential and that of an optical cavity mode. The cavity field is superimposed to the double-well potential and affects the atomic tunneling processes. The cavity field is driven by a laser red detuned from the bare cavity resonance; the dynamically changing spatial distribution of the atoms can shift the cavity in and out of resonance. At resonance the photon number is hugely enhanced and the atomic tunneling becomes amplified. The Josephson junction equations are revisited and the phase diagram is calculated. We find new solutions with finite imbalance and at the same time a lack of self-trapping solutions due to the emergence of a new separatrix resulting from enhanced tunneling.
G. Szirmai; G. Mazzarella; L. Salasnich
Subthreshold-swing physics of tunnel field-effect transistors Wei Cao, Deblina Sarkar, Yasin Khatami, Jiahao Kang, and Kaustav Banerjee
Subthreshold-swing physics of tunnel field-effect transistors Wei Cao, Deblina Sarkar, Yasin) Subthreshold-swing physics of tunnel field-effect transistors Wei Cao, Deblina Sarkar, Yasin Khatami, Jiahao
Quantum Tunneling Enabled Self-Assembly of Hydrogen Atoms on Cu(111)
Atomic and molecular self-assembly are key phenomena that underpin many important technologies. Typically, thermally enabled diffusion allows a system to sample many areas of configurational space, and ordered assemblies evolve that optimize interactions between species. Herein we describe a system in which the diffusion is quantum tunneling in nature and report the self-assembly of H atoms on a Cu(111) surface into complex arrays based on local clustering followed by larger scale islanding of these clusters. By scanning tunneling microscope tip-induced scrambling of H atom assemblies, we are able to watch the atomic scale details of H atom self-assembly in real time. The ordered arrangements we observe are complex and very different from those formed by H on other metals that occur in much simpler geometries. We contrast the diffusion and assembly of H with D, which has a much slower tunneling rate and is not able to form the large islands observed with H over equivalent time scales. Using density functional theory, we examine the interaction of H atoms on Cu(111) by calculating the differential binding energy as a function of H coverage. At the temperature of the experiments (5 K), H(D) diffusion by quantum tunneling dominates. The quantum-tunneling-enabled H and D diffusion is studied using a semiclassically corrected transition state theory coupled with density functional theory. This system constitutes the first example of quantum-tunneling-enabled self-assembly, while simultaneously demonstrating the complex ordering of H on Cu(111), a catalytically relevant surface.
Jewell, April D.; Peng, Guowen; Mattera, Michael F.; Lewis, Emily A.; Murphy, Colin J.; Kyriakou, Georgios; Mavrikakis, Manos; Sykes, E. Charles H.
Tunneling density of states of high Tc superconductors d-wave BCS model vs. SU(2) slave boson model
Tunneling density of states of high Tc superconductors d-wave BCS model vs. SU(2) slave boson model conductance curves in the superconducting state at zero temperature. Comparing the two results obtained via Tunneling spectroscopy has been one of the funda- mental tools in studying the superconducting state
Wen, Xiao-Gang
Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy study
Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy, Texas 77843-3255 Received 14 October 1997; accepted 6 April 1998 Al clusters supported on TiO2(110) have been investigated using scanning tunneling microscopy. Al interacts strongly with the TiO2(110) surface
Goodman, Wayne
Ultrafast metal-insulator varistors based on tunable Al2O3 tunnel junctions Michael A. Weimer,1,2
Ultrafast metal-insulator varistors based on tunable Al2O3 tunnel junctions Michael A. Weimer,1; accepted 4 April 2008; published online 21 April 2008 Ultrafast metal-insulator varistors have been oxide varistors. These characteristics result from the FowlerNordheim tunneling of electrons through
George, Steven M.
Z .Tunnelling and Underground Space Technology 16 2001 107 114 Experimental investigation on the breakage of hard rock by
Z .Tunnelling and Underground Space Technology 16 2001 107 114 Experimental investigation, shearing and complete clean- ing of the crushed zone would raise the rate of penetra- tion and maximize bitTunnelling and Underground Space Technology 16 2001 107 114108 Fig. 1. Layout of PDC button and waterjets. The depth of cuts
Role of midgap states in the inelastic tunneling between a d-wave superconductor and a normal metal
IT mediated by the phonons in the barrier or of the electrodes at the barrier. Unlike in N-N tunneling, where the excitable mode frequencies are revealed in d� I/d�V, here dI/dV is already sufficient to reveal the same. Comparing with N-S (s-wave) tunneling...
Far-infrared laser vibration-rotation-tunneling spectroscopy of the propane-water compkx: Torsional dynamics of the hydrogen
Far-infrared laser vibration-rotation-tunneling spectroscopy of the propane-water compkx: Torsional 1993) The far-infrared laservibration-rotation-tunneling (FIR-VRT) spectrumof the propane-water complex calculations. In the present paper and in its counterpart,13we present our results for the water-propane
Note: Long-range scanning tunneling microscope for the study of nanostructures on insulating substrates
The scanning tunneling microscope (STM) is a powerful tool for studying the electronic properties at the atomic level, however, it is of relatively small scanning range and the fact that it can only operate on conducting samples prevents its application to study heterogeneous samples consisting of conducting and insulating regions. Here we present a long-range scanning tunneling microscope capable of detecting conducting micro and nanostructures on insulating substrates using a technique based on the capacitance between the tip and the sample and performing STM studies.
Molina-Mendoza, Aday J., E-mail: email@example.com [Departamento de F�sica de la Materia Condensada, Universidad Aut�noma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Rodrigo, Jos� G.; Rubio-Bollinger, Gabino [Departamento de F�sica de la Materia Condensada, Universidad Aut�noma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC) and Instituto Universitario de Ciencia de Materiales �Nicol�s Cabrera,� Universidad Aut�noma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Island, Joshua; Burzuri, Enrique; Zant, Herre S. J. van der [Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands); Agra�t, Nicol�s [Departamento de F�sica de la Materia Condensada, Universidad Aut�noma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain) [Departamento de F�sica de la Materia Condensada, Universidad Aut�noma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC) and Instituto Universitario de Ciencia de Materiales �Nicol�s Cabrera,� Universidad Aut�noma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Instituto Madrile�o de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, E-28049 Madrid (Spain)
1D-1D tunneling between vertically coupled GaAs/AlGaAs quantum wires.
We report low-dimensional transport and tunneling in an independently contacted vertically coupled quantum wire system, with a 7.5 nm barrier between the wires. The derivative of the linear conductance shows evidence for both single wire occupation and coupling between the wires. This provides a map of the subband occupation that illustrates the control that we have over the vertically coupled double quantum wires. Preliminary tunneling results indicate a sharp 1D-1D peak in conjunction with a broad 2D-2D background signal. This 1D-1D peak is sensitively dependent on the top and bottom split gate voltage.
Seamons, John Andrew; Lilly, Michael Patrick; Reno, John Louis; Bielejec, Edward Salvador
A micrometer-size movable light emitting area in a resonant tunneling light emitting diode
We report on the fabrication of a micrometer-size movable light emitting area in a GaAs/AlAs quantum well resonant tunneling p-i-n diode. The spatial position of the micrometer-size light emitting area shifts linearly with increasing applied bias, up to 30??m for a bias increment of 0.2?V. Also, the simultaneous resonant tunneling injection of both electrons and holes into the quantum well states is achieved at specific positions of the diode, thus resulting in a tenfold increase of the electroluminescence intensity.
Pettinari, G., E-mail: email@example.com [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); National Research Council (CNR), Institute for Photonics and Nanotechnologies (IFN-CNR), Via Cineto Romano 42, 00156 Roma (Italy); Balakrishnan, N.; Makarovsky, O.; Campion, R. P.; Patan�, A. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Polimeni, A.; Capizzi, M. [CNISM-Dipartimento di Fisica, Sapienza Universit� di Roma, P.le A. Moro 2, 00185 Roma (Italy)] [CNISM-Dipartimento di Fisica, Sapienza Universit� di Roma, P.le A. Moro 2, 00185 Roma (Italy)
Tunneling characteristics in chemical vapor deposited graphene�hexagonal boron nitride�graphene junctions
Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate graphene�hexagonal boron nitride�graphene symmetric field effect transistors. Gate control of the tunneling characteristics is observed similar to previously reported results for exfoliated graphene�hexagonal boron nitride�graphene devices. Density-of-states features are observed in the tunneling characteristics of the devices, although without large resonant peaks that would arise from lateral momentum conservation. The lack of distinct resonant behavior is attributed to disorder in the devices, and a possible source of the disorder is discussed.
Roy, T.; Hesabi, Z. R.; Joiner, C. A.; Vogel, E. M. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Liu, L.; Gu, G. [Department of Electrical Engineering and Computer Science, University of Tennessee, 1520 Middle Drive, Knoxville, Tennessee 37996 (United States); Barrera, S. de la; Feenstra, R. M. [Department of Physics, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213 (United States); Chakrabarti, B. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Department of Materials Science and Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080 (United States)
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Overcoming tunnel vision: Redirecting the U.S. high-level nuclear waste program
permission. Overcoming tunnel vision: Redirecting the U.S. high-level nuclear waste program James Flynn
Kammen, Daniel M.
Types of Costs Types of Cost Estimates
� Types of Costs � Types of Cost Estimates � Methods to estimate capital costs MIN E 408: Mining% accuracy. � 2-5% of pre-production capital Types of Cost Estimates #12;3. Definitive � Based on definitive-even $ Production Level Fixed Cost Break-even $ Production Level Cost-Revenue Relationships � Capital Costs (or
Boisvert, Jeff
Local tunneling characteristics near a grain boundary of a d-wave superconductor as probed by a normal-metal or a low-Tc-superconductor STM tip
We studied the local single-particle tunneling characteristics [as observed with scanning tunnel microscopy (STM)] for N D and S D tunneling, where N is a normal metal, S is a s-wave superconductor, and D is a d-wave superconductor with a {100...
Zhao, Hongwei
Inelastic tunneling conductance and magnetoresistance investigations in dual ion-beam sputtered CoFeB(110)/MgO/CoFeB (110) magnetic tunnel junctions
Magnetic tunnel junctions (MTJs) comprising Ta(5)/NiFe(5)/IrMn(15)/CoFeB(5)/Mg(1)/MgO(3.5)/ CoFeB(5)/Ta(5)/Ag(20) (thickness in nm) with (110) oriented CoFeB layers are grown using dual ion beam sputtering. The tunnel magnetoresistance (TMR) of MTJs is found to be significantly bias dependent and exhibits zero bias anomaly (ZBA) which is attributed to the presence of magnetic impurities or diffusion of Mn from antiferromagnetic IrMn in the barrier. Adjacent to the ZBA, two peaks at 24?�?3?mV and 34?�?3?mV are also observed, which differ both in intensity as well as their position in the antiparallel and parallel magnetic states, suggesting that they are due to magnon excitations. In addition to this, a phonon peak at 65?�?3?mV is also observed. The effect of temperature on the inelastic and elastic tunneling contributions is studied in detail in 25�300?K range using the Glazman and Matveev model. Ten series of localized states are found to be involved in hopping conduction in the forbidden gap of MgO barrier. The effect of presence of such inelastic channels is found to be insignificant at low temperatures yielding sizeable enhancement in TMR.
Bhusan Singh, Braj; Chaudhary, Sujeet, E-mail: firstname.lastname@example.com [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India)
Charge separation and transfer in hybrid type II tunneling structures of CdTe and CdSe nanocrystals.
??Halbleiter-Nanokristalle sind eine besondere Materialklasse in den Nanowissenschaften. Sie sind kleinste Halbleiter-Kristalle, die an ihrer Oberfl�che mittels organischer Chemie passiviert wurden. Damit k�nnen Sie auf� (more)
Gro�, Dieter
2000-13 CALCULATIONS OF FIRE SMOKE BEHAVIOUR IN LONG RAIL TUNNELS S. DA�?RON, E. RUFFIN INERIS Parc in complex underground networks, we want to implement a coupling between a ID ventilation code and a CFD model or a zone model. The project consists in 3 main steps: the development of a ID ventilation code
Paris-Sud XI, Université de
Spontaneous emission from a two--level atom tunneling in a double--well potential
We study a two-level atom in a double--well potential coupled to a continuum of electromagnetic modes (black body radiation in three dimensions at zero absolute temperature). Internal and external degrees of the atom couple due to recoil during emission of a photon. We provide a full analysis of the problem in the long wavelengths limit up to the border of the Lamb-Dicke regime, including a study of the internal dynamics of the atom (spontaneous emission), the tunneling motion, and the electric field of the emitted photon. The tunneling process itself may or may not decohere depending on the wavelength corresponding to the internal transition compared to the distance between the two wells of the external potential, as well as on the spontaneous emission rate compared to the tunneling frequency. Interference fringes appear in the emitted light from a tunneling atom, or an atom in a stationary coherent superposition of its center--of--mass motion, if the wavelength is comparable to the well separation, but only if the external state of the atom is post-selected.
Daniel Braun; John Martin
Investigation of Terahertz Vibration-Rotation Tunneling Spectra for the Water Octamer
Investigation of Terahertz Vibration-Rotation Tunneling Spectra for the Water Octamer Jeremy O, and Richard J. Saykally*, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom Department of Chemistry, University of California, Berkeley, California 94720
Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada
Surface-to-tunnel seismic tomography studies at Yucca Mountain, Nevada Roland Gritto, Valeri A in the proposed nuclear waste repository area at Yucca Mountain, Nevada. A 5-km-long source line and a 3-km-long receiver line were located on top of Yucca Mountain ridge and inside the Exploratory Study Facility (ESF
Korneev, Valeri A.
Resonant tunneling and the bimodal symmetric fission of sup 258 Fm
The concept of resonant tunneling is invoked to explain the sharp drop in the measured spontaneous-fission half-life when going from {sup 256}Fm to {sup 258}Fm. Various consequences of such a suggestion on the other observed characteristics of the bimodal symmetric fission of {sup 258}Fm are briefly discussed.
Bhandari, B.S. (Department of Physics, Faculty of Science, University of Garyounis, Benghazi, Libya (LY))
Low resistivity of Pt silicide nanowires measured using double-scanning-probe tunneling microscope
experimentally shown to be conductive.810 However, RE metal silicide NWs are easily oxidized, so that inert NWs similarly to RE metal silicide NWs.11 It is essential to study the electrical properties, especiallyLow resistivity of Pt silicide nanowires measured using double-scanning- probe tunneling microscope
Kim, Sehun
TESLA-FEL 2007-02 Radiation dosimetry in FLASH Tunnel using
1 TESLA-FEL 2007-02 Radiation dosimetry in FLASH Tunnel using Passive dosimeters Bhaskar Mukherjee, Radiation dosimetry, Radiation effect, Superconducting Cavities, XFEL 1. INTRODUCTION In April 2006, at DESY-term basis. Conventional radiation monitoring devices are usually bulky and the associated nuclear
Angular domain optical imaging of turbid media using enhanced micro-tunnel filter arrays
performed in tissue mimicking phantoms using a 2-cm thick optical cell with 0.25% IntralipidTM and a near infrared laser. This paper also presents experimental results of the angular domain imaging system employing novel micro-tunnel arrays with minimal internal reflection which can accept the non- scattered
Chapman, Glenn H.
1 WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES J. J. Miau*1 were carried out to study the aerodynamic performance of three vertical axis wind turbines (VAWTs. On the other hand, the characteristics of unsteady flow around the helical wind turbine were studied with a hot
Leu, Tzong-Shyng "Jeremy"
Benchmark of aerodynamic cycling helmets using a refined wind tunnel test protocol for helmet drag research
The study of aerodynamics is very important in the world of cycling. Wind tunnel research is conducted on most of the equipment that is used by a rider and is a critical factor in the advancement of the sport. However, to ...
Sidelko, Stephanie
Decay of the cosmological constant: Equivalence of quantum tunneling and thermal activation in two spacetime dimensions
We study the decay of the cosmological constant in two spacetime dimensions through production of pairs. We show that the same nucleation process looks as quantum-mechanical tunneling (instanton) to one Killing observer and as thermal activation (thermalon) to another. Thus, we find another striking example of the deep interplay between gravity, thermodynamics and quantum mechanics which becomes apparent in presence of horizons.
Gomberoff, Andres; Henneaux, Marc; Teitelboim, Claudio [Centro de Estudios Cientificos (CECS), Valdivia (Chile); Physique Theorique et Mathematique, Universite Libre de Bruxelles and International Solvay Institutes, ULB Campus Plaine C.P. 231, B-1050 Brussels (Belgium); Centro de Estudios Cientificos (CECS), Valdivia (Chile); Centro de Estudios Cientificos (CECS), Valdivia (Chile)
Tunable few-electron double quantum dots and Klein tunnelling in ultraclean carbon nanotubes
Tunable few-electron double quantum dots and Klein tunnelling in ultraclean carbon nanotubes G. A. Steele*, G. Gotz and L. P. Kouwenhoven Quantum dots defined in carbon nanotubes are a platform for both with highly tunable barriers1 , but disorder has prevented tunable nanotube- based quantum-dot devices from
Nonequilibrium Tunneling Spectroscopy in Carbon Nanotubes Yung-Fu Chen,1
of the local electron distribution functions, and hence energy relaxation rates, in nanotubes that have biasNonequilibrium Tunneling Spectroscopy in Carbon Nanotubes Yung-Fu Chen,1 Travis Dirks,1 Gassem Al; published 23 January 2009) We report measurements of the nonequilibrium electron energy distribution
Birge, Norman
Length control of individual carbon nanotubes by nanostructuring with a scanning tunneling microscope
and quantum-size energy-level splitting.6,7 The quantum transport properties of nanotubes strongly dependLength control of individual carbon nanotubes by nanostructuring with a scanning tunneling of carbon nanotubes. Individual carbon nanotubes can be locally cut by applying a voltage pulse to the tip
Observation of spin-dependent quantum well resonant tunneling in textured CoFeB layers
We report the observation of spin-dependent quantum well (QW) resonant tunneling in textured CoFeB free layers of single MgO magnetic tunnel junctions (MTJs). The inelastic electron tunneling spectroscopy spectra clearly show the presence of resonant oscillations in the parallel configuration, which are related with the appearance of majority-spin ?{sub 1} QW states in the CoFeB free layer. To gain a quantitative understanding, we calculated QW state positions in the voltage-thickness plane using the so-called phase accumulation model (PAM) and compared the PAM solutions with the experimental resonant voltages observed for a set of MTJs with different CoFeB free layer thicknesses (t{sub fl}?=?1.55, 1.65, 1.95, and 3.0?nm). An overall good agreement between experiment and theory was obtained. An enhancement of the tunnel magnetoresistance with bias is observed in a bias voltage region corresponding to the resonant oscillations.
Teixeira, J. M., E-mail: firstname.lastname@example.com; Costa, J. D.; Ventura, J.; Sousa, J. B. [IFIMUP and IN-Institute of Nanoscience and Nanotechnology, and Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Wisniowski, P. [Department of Electronics, AGH University of Science and Technology, 30-059 Krakow (Poland); Freitas, P. P. [INESC-MN and IN-Institute of Nanoscience and Nanotechnology, Rua Alves Redol, 9-1, 1000-029 Lisbon (Portugal)
Speech Enhancement of Noisy Speech Using Log-Spectral Amplitude Estimator and Harmonic Tunneling
Speech Enhancement of Noisy Speech Using Log-Spectral Amplitude Estimator and Harmonic Tunneling we present a two stage noise reduction algo- rithm for speech enhancement. The speech noise removal and decreases the performance of speech coding and speech recog- nition systems. In speech enhancement
Wichmann, Felix
Close-in blasting at the TRI-MET light rail tunnels in Portland, Oregon
Frontier/Traylor Joint Venture is presently constructing a section of the Tri-County Metropolitan Transit District of Oregon`s (TRI-MET) Westside Light Rail System. This new section will extend Portland`s existing transit system to the western suburbs of Beaverton and Hillsboro. The drill-blast excavations at this project include 10,000 feet of 20 foot tunnel, 18 cross passages, three shafts, an underground railway station, and a U-wall open cut. From a blast designer`s perspective, this job has been extremely challenging. Blast vibration is limited to 0.5 ips at 200 feet or at the nearest structure, and airblast is limited to 129 dB--linear peak and 96 dB--C scale. The tunnels pass under heavily built up areas and have top of tunnel to surface cover distances as low as 70 feet. Surface blasting in the 26,000 cubic yard U-wall excavation was limited to five short nighttime periods due to its proximity to the very busy highway 26. This paper describes the techniques that were used to develop safe blasting designs for the TRI-MET Surface blasts and tunnel rounds. It also discusses the measures that were necessary to mitigate noise, vibration, and flyrock.
Revey, G.F.; Painter, D.Z.
Crossover from tunneling to meta.llic behavior in superconductofgsemiconductor contacts
-dominated transport at the superconductor-semiconductor contacts as Schottky barrier thickness decreases of such a crossover in a thin-film structure, and are of interest for investigations of hybrid superconductor-semiconductorCrossover from tunneling to meta.llic behavior in superconductofgsemiconductor contacts A. W
Woodall, Jerry M.
Electromagnetic Realization of Orders-of-Magnitude Tunneling Enhancement in a DoubleWell System
Tun Ltd., MTM Scientific Industries Center, Building 22, P.O. Box 15017, Haifa 31905, Israel (Received 1 in Refs. [8,13] that the tunneling enhancement can also be obtained in a weakly driven system fabricated using planar silica over silicon technology. The waveguides' core was made from a silica
Narevicius, Edvardas
Tunneling characteristics in chemical vapor deposited graphene hexagonal boron nitride graphene junctions
1 Tunneling characteristics in chemical vapor deposited graphene hexagonal boron nitride graphene junctions T. Roy1 , L. Liu2 , S. de la Barrera,3 B. Chakrabarti1,4 , Z. R. Hesabi1 , C. A. Joiner1 Abstract: Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate
Feenstra, Randall
Simultaneous topographic and elemental chemical and magnetic contrast in scanning tunneling microscopy
A method and system for performing simultaneous topographic and elemental chemical and magnetic contrast analysis in a scanning, tunneling microscope. The method and system also includes nanofabricated coaxial multilayer tips with a nanoscale conducting apex and a programmable in-situ nanomanipulator to fabricate these tips and also to rotate tips controllably.
Rose, Volker; Preissner, Curt A; Hla, Saw-Wai; Wang, Kangkang; Rosenmann, Daniel
Modelling a Car Safety Controller in Road Tunnels using Hybrid Petri Nets A. Bobbio[1
Modelling a Car Safety Controller in Road Tunnels using Hybrid Petri Nets A. Bobbio[1] , M this specific issue and proposes a hybrid modeling approach based on fluid Petri nets (FPN). An FPN is used that FPN is a valid paradigm to model the dynamics of a car in a detailed way. 1 Introduction In the last
Horv�th, Andr�s
Giant higher harmonic generation in mesoscopic metal wires and rings interrupted by tunnel junctions
Giant higher harmonic generation in mesoscopic metal wires and rings interrupted by tunnel 5046, 2600 GA Delft, The Netherlands Received 19 December 1997 Higher harmonic generation in mesoscopic is biased with a sinusoidal varying current, we observe giant higher harmon- ics in the conductance
van Oudenaarden, Alexander
Predicted scanning tunneling microscopy images of carbon nanotubes with atomic vacancies
Predicted scanning tunneling microscopy images of carbon nanotubes with atomic vacancies Arkady V STM images of both metallic and semiconducting single-wall carbon nanotubes with atomic vacancies predict that vacancies should result in the formation of hillock-like features in STM images of metallic
Krasheninnikov, Arkady V.
Measurement of the Equivalent Thermal Resistance of Rooftop Lawns in a Hot-Climate Wind Tunnel
rooftop lawn. A hot-climate wind tunnel experiment was carried out in order to obtain and analyze the heat and moisture transport in the rooftop lawn. Furthermore, a calculation with the energy conservation equation was carried out using the results...
Meng, Q.; Zhang, Y.; Zhang, L.
Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain, Nevada
Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain was heated to replicate the effects of long-term storage of decaying nuclear waste and to study the effects for the long- term storage of high-level nuclear waste from reactors and decom- missioned atomic weapons
Snieder, Roel
Resonance tunneling of cooper pairs in a superconductor-polymer-superconductor josephson junction
It is shown that the superconducting current flowing though a polymer in a superconductor-polymer-superconductor Josephson structure is due to resonant tunneling of Cooper pairs. The critical current and the thickness of the polymer in which the superconducting current is observed depend on the coherence length of a Cooper pair in the superconductor contacting the polymer.
Ionov, A. I., E-mail: email@example.com [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)
Thoughts on entropic gravity in the Parikh-Wilczek tunneling model of Hawking radiation
In this letter, we use the Parikh-Wilczek tunneling model of Hawking radiation to illustrate that a reformulation of Verlinde's entropic gravity is needed to derive the Newton's law for a temperature-varying screen, demanded by the conservation of energy. Furthermore, the entropy stored in the holographic screen is shown to be additive and its temperature dependence can be obtained.
Wen-Yu Wen
Molecular engineering of oligomerization and metabolite channeling through a molecular tunnel of carbamoyl phosphate synthetase
-23, and Gly-575 from the large subunit of CPS were substituted by mutagenesis with bulkier amino acids in an attempt to obstruct and/or hinder the passage of the unstable intermediate through the carbamate tunnel. The kinetic data are consistent...
Kim, Jungwook
use of numerical analyses, particularly non-linear finite element methods, over a period of more than. Deformation fields based on the superposition of fundamental, singularity solutions are shown to differ only of very shallow tunnels. The Authors demonstrate a simplified method to account for soil plasticity
Entekhabi, Dara
Policy Name: Golf Carts in Tunnels Originating/Responsible Department: Facilities Management and Planning
to their manager or department head all incidents involving injury to persons or damage to property. ReportingPolicy Name: Golf Carts in Tunnels Originating/Responsible Department: Facilities Management and Planning Approval Authority: Senior Management Committee Date of Original Policy: October 2008 Last Updated
Carleton University
Geology of the Trans-Missouri River Tunnel project, Kansas City, Missouri
The geology of the Missouri River Valley at Kansas City is interpreted from the borehole and construction site data along the route of the Trans-Missouri River Tunnel, a 4.4 km long water tunnel constructed at a depth of 90--97.5 m below the floodplain of the Missouri River. The data from the site investigation is used to construct a detailed stratigraphic cross-section of the subsurface units to a depth of 120 m and extending in a north-south direction the length of the tunnel. The rock section is divided into 2 broad categories, (a) alluvium and (b) bedrock. The alluvium (Pleistocene-Holocene) fills the Missouri River Valley to a depth of 38 m along the tunnel route. An exception is a deep narrow channel near the center of the valley, the alluvium is 55 m thick and the lower several meters of the channel is filled with glacial till( ). The alluvium rests unconformably on Pennsylvanian bedrock consisting of thin strata arranged in cyclical sequences or cyclothems and belonging to the following groups in ascending order: Upper Cherokee, Marmaton and Lower Pleasanton. The test drill core data made it possible to conduct a detailed analysis of the subsurface stratigraphy. Of major importance is the stratigraphic position of a thick channel-fill deposit in the Labette Formation, Marmaton Group, a producing horizon in several small oil and gas fields in western Missouri and eastern Kansas. The 327.6 cm dia. bore for the essentially horizontal tunnel is constructed in predominately silty and sandy gray shale located stratigraphically near the Cherokee-Marmaton contact and in younger channel-fill deposits.
Gentile, R.J. (Univ. of Missouri, Kansas City, MO (United States). Dept. of Geosciences)
Titanium Silicide Islands on Atomically Clean Si(100): Identifying Single Electron Tunneling Effects
Titanium silicide islands have been formed by the ultrahigh vacuum deposition of thin films of titanium (< 2 nm) on atomically clean Si(100) substrates followed by annealing to ~800 degrees C. Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy have been performed on these islands to record current-voltage (I-V) curves. Because each island forms a double barrier tunnel junction (DBTJ) structure with the STM tip and the substrate, they would be expected to exhibit single electron tunneling (SET) according to the orthodox model of SET. Some of the islands formed are small enough (diameter < 10 nm) to exhibit SET at room temperature and evidence of SET has been identified in some of the I-V curves recorded from these small islands. Those curves are analyzed within the framework of the orthodox model and are found to be consistent with that model, except for slight discrepancies of the shape of the I-V curves at current steps. However, most islands that were expected to exhibit SET did not do so, and the reasons for the absence of observable SET are evaluated. The most likely reasons for the absence of SET are determined to be a wide depletion region in the substrate and Schottky barrier lowering due to Fermi level pinning by surface states of the clean silicon near the islands. The results establish that although the Schottky barrier can act as an effective tunnel junction in a DBTJ structure, the islands may be unreliable in future nanoelectronic devices. Therefore, methods are discussed to improve the reliability of future devices.
Joseph L. Tedesco; J. E. Rowe; Robert J. Nemanich
Estimation of deformation and stiffness of fractures close to tunnels using data from single-hole hydraulic testing and grouting
Sealing of tunnels in fractured rocks is commonly performed by pre- or post-excavation grouting. The grouting boreholes are frequently drilled close to the tunnel wall, an area where rock stresses can be low and fractures can more easily open up during grout pressurization. In this paper we suggest that data from hydraulic testing and grouting can be used to identify grout-induced fracture opening, to estimate fracture stiffness of such fractures, and to evaluate its impact on the grout performance. A conceptual model and a method are presented for estimating fracture stiffness. The method is demonstrated using grouting data from four pre-excavation grouting boreholes at a shallow tunnel (50 m) in Nygard, Sweden, and two post-excavation grouting boreholes at a deep tunnel (450 m) in Aespoe HRL, Sweden. The estimated stiffness of intersecting fractures for the boreholes at the shallow Nygard tunnel are low (2-5 GPa/m) and in agreement with literature data from field experiments at other fractured rock sites. Higher stiffness was obtained for the deeper tunnel boreholes at Aespoe which is reasonable considering that generally higher rock stresses are expected at greater depths. Our method of identifying and evaluating the properties and impact of deforming fractures might be most applicable when grouting takes place in boreholes adjacent to the tunnel wall, where local stresses might be low and where deforming (opening) fractures may take most of the grout.
Fransson, A.; Tsang, C.-F.; Rutqvist, J.; Gustafson, G.
On the application of MHD-gas acceleration wind tunnels to investigate hypersonic gas flows over bodies
The paper contains the results of applying a hypervelocity MHD-gas acceleration wind tunnel to investigations of flows over bodies. Consideration is given to the conditions of re producing gas dynamic and thermochemical flow parameters as applied to different types of tests: pressure and heat flux distributions, determination of shock wave positions and shapes. The measured heat fluxes towards the leading edge of swept wings are presented for sweep angles ranging from 0{degrees} to 60{degrees} at a flow velocity of U{approximately}6000 m/s. An appreciable influence of the surface nonequilibrium and catalyticity on their values is indicated. Possible investigations of flows over bodies at ultra high heat fluxes, q {approximately} 10 kW/m{sup 2} are discussed. The results of applying the facility to the verification of calculation codes and thermodynamic gas models are analyzed for flows over a hemisphere, a cone and a wedge. The calculated and measured surface pressure distributions are in good agreement for a hemisphere and satisfactory for a cone and a wedge. The shock wave positions and shapes are compared. It is shown that respective gas glow is impossible to use for this purpose.
Alfyorov, V.I.; Yegorov, I.V.; Shcherbakov, G.I. [Central Aerodrodynamic Institute (TsAGI), Zhukovsky (Russian Federation)
Highly transparent low capacitance plasma enhanced atomic layer deposition Al{sub 2}O{sub 3}-HfO{sub 2} tunnel junction engineering
The development of metallic single electron transistor (SET) depends on the downscaling and the electrical properties of its tunnel junctions. These tunnel junctions should insure high tunnel current levels, low thermionic current, and low capacitance. The authors use atomic layer deposition to fabricate Al{sub 2}O{sub 3} and HfO{sub 2} thin layers. Tunnel barrier engineering allows the achievement of low capacitance Al{sub 2}O{sub 3} and HfO{sub 2} tunnel junctions using optimized annealing and plasma exposure conditions. Different stacks were designed and fabricated to increase the transparency of the tunnel junction while minimizing thermionic current. This tunnel junction is meant to be integrated in SET to enhance its electrical properties (e.g., operating temperature, I{sub ON}/I{sub OFF} ratio)
El Hajjam, Khalil, E-mail: email@example.com [INL, INSA, UMR CNRS 5270, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex, France and Institut Interdisciplinaire d'Innovation Technologique (3IT), Universit� de Sherbrooke, 3000 Boulevard Universit�, Sherbrooke, J1K OA5, Qu�bec (Canada); Baboux, Nicolas; Calmon, Francis [INL, INSA, UMR CNRS 5270, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Souifi, Abdelkader [Laboratoire Nanotechnologies Nanosyst�mes (LN2)-CNRS UMI-3463, Universit� de Sherbrooke, 3000 Boulevard Universit�, Sherbrooke, J1K OA5, Qu�bec (Canada); Poncelet, Olivier; Francis, Laurent A. [ICTEAM, ELEN, UCL, Place du Levant 3, 1348 Louvain-la-Neuve (Belgium); Ecoffey, Serge; Drouin, Dominique [Laboratoire Nanotechnologies Nanosyst�mes (LN2)-CNRS UMI-3463, Universit� de Sherbrooke, 3000 Boulevard Universit�, Sherbrooke, J1K OA5, Qu�bec, Canada and Institut Interdisciplinaire d'Innovation Technologique (3IT), Universit� de Sherbrooke, 3000 Boulevard Universit�, Sherbrooke, J1K OA5, Qu�bec (Canada)
Local tunneling characteristics near a grain boundary of a d-wave superconductor as probed by a normal-metal or a low-T-c-superconductor STM tip
We study the local single-particle tunneling characteristics [as observed with scanning tunnel microscopy (STM)] for N-D and S-D tunneling, where D is a d-wave superconductor with a {100}{110} grain boundary. The tunneling Hamiltonian method is used...
Zhao, HW; Hu, Chia-Ren.
A comparative investigation of laminar separation bubbles at low Reynolds numbers in wind tunnels and free flight environments
in the Notre Dame wind tunnel. The airfoil support structure was designed so that it could be used as a free-standing test bed in large wind tunnels and mounted atop the research aircraft. The primary criteria in its design were 1) simplicity... the results of the airfoil study as well as the results of per- 18 forming this kind of study in a free-flight environment. Chapter V draws conclusions from the comparisons between free-flight and wind- tunnel data. Also listed are recommendations...
Blohowiak, James Russell
Tunneling and nonlinear transport in a vertically coupled GaAs/AlGaAs double quantum wire system.
We report low-dimensional tunneling in an independently contacted vertically coupled quantum wire system. This nanostructure is fabricated in a high quality GaAs/AlGaAs parallel double quantum well heterostructure. Using a unique flip chip technique to align top and bottom split gates to form low-dimensional constrictions in each of the independently contacted quantum wells we explicitly control the subband occupation of the individual wires. In addition to the expected two-dimensional (2D)-2D tunneling results, we have found additional tunneling features that are related to the one-dimensional quantum wires.
Magnetic tunnel junctions for magnetic field sensor by using CoFeB sensing layer capped with MgO film
We evaluated MgO-based magnetic tunnel junctions (MTJs) for magnetic field sensors with spin-valve-type structures in the CoFeB sensing layer capped by an MgO film in order to obtain both top and bottom interfaces of MgO/CoFeB exhibiting interfacial perpendicular magnetic anisotropy (PMA). Hysteresis of the CoFeB sensing layer in these MTJs annealed at 275?�C was suppressed at a thickness of the sensing layer below 1.2?nm by interfacial PMA. We confirmed that the CoFeB sensing layers capped with MgO suppress the thickness dependences of both the magnetoresistance ratio and the magnetic behaviors of the CoFeB sensing layer more than that of the MTJ with a Ta capping layer. MgO-based MTJs with MgO capping layers can improve the controllability of the characteristics for magnetic field sensors.
Takenaga, Takashi, E-mail: email@example.com; Tsuzaki, Yosuke; Yoshida, Chikako; Yamazaki, Yuichi; Hatada, Akiyoshi; Nakabayashi, Masaaki; Iba, Yoshihisa; Takahashi, Atsushi; Noshiro, Hideyuki; Tsunoda, Koji; Aoki, Masaki; Furukawa, Taisuke; Fukumoto, Hiroshi; Sugii, Toshihiro [Low-power Electronics Association and Project (LEAP), Tsukuba 305-8569 (Japan)
05-1 � Types of Costs � Types of Cost Estimates � Methods to estimate capital costs MIN E 408-Revenue Relationships � Capital Costs (or first cost or capital investment): � Expenditures made to acquire or develop capital assets � Three main classes of capital costs: 1. Depreciable Investment: � Investment allocated
Calibration of the Merrill-G.A.L.C.I.T. wind-tunnel, and a suggestion for a variable cross-section on a small high-speed wind-tunnel.
??Speed, power and flow inclination calibration tests run in the Merrill-GALCIT wind-tunnel are described and results presented. A description of the new balance-system is included.� (more)
Schwarzenbach, Jean Christophe
Quantitative study of macroscopic quantum tunneling in a dc SQUID: A system with two degrees of freedom
To test whether the theory of macroscopic quantum tunneling (MQT) is applicable to systems with 2 degrees of freedom, we experimentally investigated the switching current distribution of a dc SQUID. Using sample parameters determined from...
Li, Shaoxiong; Yu, Yang; Zhang, Y.; Qiu, W.; Han, Siyuan; Wang, Z.
Earth pressure balance (EPB) shield tunneling in Bangkok : ground response and prediction of surface settlements using artificial neural networks
Although Earth Pressure Balance (EPB) shields have been used for several decades, very little information exists about the actual mechanisms of shield-ground interaction. The ground response mechanism induced by EPB tunneling ...
Suwansawat, Suchatvee, 1972-
Silicon field-effect transistor based on quantum tunneling J. FL Tucker, Chinlee Wang, and P. Scott Carney
configuration, the gate could be offset in order to permit a shallow implant of the finished device to convert a commercial package, SEMICAD,' together with our own cal- culation of tunneling and thermionic emission
Bhargava, Rohit
Prediction of net bedload transport rates obtained in oscillating water tunnels and applicability to real surf zone waves
Experimental studies of sediment transport rates due to near shore waves are often conducted in oscillating water tunnels (OWTs). In an OWT, the oscillatory motion produced by the piston propagates almost instantaneously ...
Gonzalez-Rodriguez, David
A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 6 of 6
This report presents a historical evaluation of the U12t Tunnel on the Nevada Test Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency (DTRA). The U12t Tunnel is one of a series of tunnels used for underground nuclear weapons effects tests on the east side of Rainier and Aqueduct Mesas. Six nuclear weapons effects tests, Mint Leaf, Diamond Sculls, Husky Pup, Midas Myth/Milagro, Mighty Oak, and Mission Ghost, and one high explosive test, SPLAT, were conducted within the U12t Tunnel from 1970 to 1987. All six of the nuclear weapons effects tests and the high explosive test were sponsored by DTRA. Two conventional weapons experiments, Dipole Knight and Divine Eagle, were conducted in the tunnel portal area in 1997 and 1998. These experiments were sponsored by the Defense Special Weapons Agency. The U12t Tunnel complex is composed of the Portal and Mesa Areas and includes an underground tunnel with a main access drift and nine primary drifts, a substantial tailings pile fronting the tunnel portal, a series of discharge ponds downslope of the tailings pile, and two instrumentation trailer parks and 16 drill holes on top of Aqueduct Mesa. A total of 89 cultural features were recorded: 54 at the portal and 35 on the mesa. In the Portal Area, cultural features are mostly concrete pads and building foundations; other features include the portal, rail lines, the camel back, ventilation and cooling system components, communication equipment, and electrical equipment. On the mesa are drill holes, a few concrete pads, a loading ramp, and electrical equipment.
Harold Drollinger; Robert C. Jones; and Thomas F. Bullard; Desert Research Institute, Laurence J. Ashbaugh, Southern Nevada Courier Service and Wayne R. Griffin, Stoller-Navarro Joint Venture
Design of a high angle of attack robotic sting mount for tests in a low speed wind tunnel
AMPLIFIER SPECIFICATIONS . 92 97 G PROGRAM FLOWCHART: HIALST 100 H HARS INSTALLATION PROCEDURES 118 I ASSEMBLY DRAWINGS J ACKNOWLEDGEMENTS 137 142 VITA 143 LIST OF TABLES Table Page 1 Wear psd plastic materials considered 2 Maximum predicted... wings level in the tunnel to minimize effects on lateral-directional coefficients. 4. A 36 inch long model must be maintained near the center of the tunnel where the dynamic pressure variation does not exceed 0. 4%. 5. The mechanical system must...
Kubler, Tommy Jack
A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 1 of 6
A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 2 of 6
A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 3 of 6
A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 4 of 6
A Historical Evaluation of the U12t Tunnel, Nevada Test Site, Nye County, Nevada, Volume 5 of 6
Electrical characteristics and interface structure of magnetic tunnel junctions with hafnium oxyfluoride barrier
We have studied the effects of fluorine inclusion on the electrical transport characteristics and interface structure of the hafnium oxide barrier in a magnetic tunnel junction. The tunneling magnetoresistance (TMR) and resistance-area (RA) as a function of oxidation time show that the TMR ratio of the hafnium oxyfluoride barrier is higher (8.3%) than that of the hafnium oxide barrier (5.7%) at their optimum conditions, and the oxyfluoride barrier junctions maintain a high TMR ratio even when the RA product increases by three orders of magnitude. X-ray photoelectron spectroscopy analysis shows that the fluorine atoms in the oxyfluoride barrier play an important role in the formation of a barrier with uniform composition. We believe that the initial fluoride layer is causing the subsequent oxygen diffusion to slow down, resulting in the formation of a defect-free hafnium oxide layer. These results are consistent with what we have found for aluminum oxyfluoride barriers.
Yu, Y.Y.; Kim, D.S.; Char, K. [Center for Strongly Correlated Materials Research and School of Physics, Seoul National University, Seoul 151-742 (Korea, Republic of)
Bohm-Aharonov and Kondo effects on tunneling currents in a mesoscopic ring
We present an analysis of the Kondo effect on the Bohm-Aharonov oscillations of the tunneling currents in a mesoscopic ring with a quantum dot inserted in one of its arms. The system is described by an Anderson-impurity tight-binding Hamiltonian where the electron-electron interaction is restricted to the dot. The currents are obtained using nonequilibrium Green functions calculated through a cumulant diagrammatic expansion in the chain approximation. It is shown that at low temperature, even with the system out of resonance, the Kondo peak provides a channel for the electron to tunnel through the dot, giving rise to the Bohm-Aharonov oscillations of the current. At high temperature these oscillations are important only if the dot level is aligned to the Fermi level, when the resonance condition is satisfied. {copyright} {ital 1997} {ital The American Physical Society}
Davidovich, M.A. [Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Caixa Postal 38071, 22452-970 Rio de Janeiro, Rio de Janeiro, (Brasil)] [Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Caixa Postal 38071, 22452-970 Rio de Janeiro, Rio de Janeiro, (Brasil); Anda, E.V. [Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ Brasil, Avenida Litoranea s/n, Gragoata, 24210-340 Niteroi, Rio de Janeiro, (Brasil)] [Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ Brasil, Avenida Litoranea s/n, Gragoata, 24210-340 Niteroi, Rio de Janeiro, (Brasil); Iglesias, J.R. [Instituto de Fisica, Univerisdade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970, Porto Alegre, Rio Grande do Sul, (Brasil)] [Instituto de Fisica, Univerisdade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970, Porto Alegre, Rio Grande do Sul, (Brasil); Chiappe, G. [Departamento de Fisica, Universidad de Buenos Aires, Caixa Postal 1428-Nunez, Buenos Aires (Argentina)] [Departamento de Fisica, Universidad de Buenos Aires, Caixa Postal 1428-Nunez, Buenos Aires (Argentina)
A large volume 2000 MPA air source for the radiatively driven hypersonic wind tunnel
An ultra-high pressure air source for a hypersonic wind tunnel for fluid dynamics and combustion physics and chemistry research and development must provide a 10 kg/s pure air flow for more than 1 s at a specific enthalpy of more than 3000 kJ/kg. The nominal operating pressure and temperature condition for the air source is 2000 MPa and 900 K. A radial array of variable radial support intensifiers connected to an axial manifold provides an arbitrarily large total high pressure volume. This configuration also provides solutions to cross bore stress concentrations and the decrease in material strength with temperature. [hypersonic, high pressure, air, wind tunnel, ground testing
Constantino, M
Topological Quantum Computation by Manipulating Quantum Tunneling Effect of the Toric Codes
Quantum computers are predicted to utilize quantum states to perform memory and to process tasks far faster than those of conventional classical computers. In this paper we show a new road towards building fault tolerance quantum computer by tuning quantum tunneling effect of the degenerate quantum states in topological order, instead of by braiding anyons. Using a designer Hamiltonian - the Wen-Plaquette model as an example, we study its quantum tunneling effect of the toric codes and show how to control the toric code to realize topological quantum computation (TQC). In particular, we give a proposal to the measurement of TQC. In the end the realization of the Wen-Plaquette model in cold atoms is discussed.
Su-Peng Kou
Synthesis, fabrication and characterization of Ge/Si axial nanowire heterostructure tunnel FETs
Axial Ge/Si heterostructure nanowires allow energy band-edge engineering along the axis of the nanowire, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two advances in the area of heterostructure nanowires and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure nanowires with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these nanowires for high-on currents and suppressed ambipolar behavior. Initial prototype devices resulted in a current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. These results demonstrate the potential of such asymmetric heterostructures (both in the semiconductor channel and metal-semiconductor barrier heights) for low-power and high performance electronics.
Picraux, Samuel T [Los Alamos National Laboratory; Dayeh, Shadi A [Los Alamos National Laboratory
Spectroscopy and capacitance measurements of tunneling resonances in an Sb-implanted point contact.
We fabricated a split-gate defined point contact in a double gate enhancement mode Si-MOS device, and implanted Sb donor atoms using a self-aligned process. E-beam lithography in combination with a timed implant gives us excellent control over the placement of dopant atoms, and acts as a stepping stone to focused ion beam implantation of single donors. Our approach allows us considerable latitude in experimental design in-situ. We have identified two resonance conditions in the point contact conductance as a function of split gate voltage. Using tunneling spectroscopy, we probed their electronic structure as a function of temperature and magnetic field. We also determine the capacitive coupling between the resonant feature and several gates. Comparison between experimental values and extensive quasi-classical simulations constrain the location and energy of the resonant level. We discuss our results and how they may apply to resonant tunneling through a single donor.
Wendt, Joel Robert; Rahman, Rajib; Ten Eyck, Gregory A.; Eng, Kevin; Carroll, Malcolm S.; Young, Ralph Watson; Lilly, Michael Patrick; Stalford, Harold Lenn; Bishop, Nathaniel; Bielejec, Edward Salvador
Conceptual design for an electron-beam heated hypersonic wind tunnel
There is a need for hypersonic wind-tunnel testing at about mach 10 and above using natural air and simulating temperatures and pressures which are prototypic of flight at 50 km altitude or below. With traditional wind-tunnel techniques, gas cooling during expansion results in exit temperatures which are too low. Miles, et al., have proposed overcoming this difficulty by heating the air with a laser beam as it expands in the wind-tunnel nozzle. This report discusses an alternative option of using a high-power electron beam to heat the air as it expands. In the e-beam heating concept, the electron beam is injected into the wind-tunnel nozzle near the exit and then is guided upstream toward the nozzle throat by a strong axial magnetic field. The beam deposits most of its power in the dense air near the throat where the expansion rate is greatest. A conceptual design is presented for a large-scale system which achieves Mach 14 for 0.1 seconds with an exit diameter of 2.8 meters. It requires 450 MW of electron beam power (5 MeV at 90 A). The guiding field is 500 G for most of the transport length and increases to 100 kG near the throat to converge the beam to a 1.0-cm diameter. The beam generator is a DC accelerator using a Marx bank (of capacitors) and a diode stack with a hot cathode. 14 refs. 38 figs., 9 tabs.
Lipinski, R.J.; Kensek, R.P.
Laser control of free-carrier density in solids through field-enhanced multiphonon tunneling recombination
Enhancement of multiphonon tunneling recombination of free carriers in strong laser fields is shown to offer a mechanism whereby ultrafast carrier-density dynamics in a semiconductor can be controlled by properly shaped laser pulses. This regime of laser-solid interaction enables an ultrafast switching of optical and electric properties of semiconductor materials, suggesting new strategies for laser micromachining and nanomachining, optical data processing, and ultrafast plasmonics.
Zheltikov, A. M.; Voronin, A. A. [Department of Physics, International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Shneider, M. N.; Miles, R. B. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263 (United States)
Evaluation of PM10 and Total Suspended Particulate Sampler Performance Through Wind Tunnel Testing
.................................................... 86 APPENDIX F SHARP-EDGE ORIFICE METER CALIBRATION PROCEDURE ................................................................................ 89 APPENDIX G TEXAS A&M WIND TUNNEL OPERATION PROCEDURE ... 92 APPENDIX H MALVER MASTERSIZER 2000... Velocity Uniformity ?10% for 2, 8 and 24 km/h Measurement 1) Minimum of 12 test points 2) Monitoring techniques: precision? 2% ; accuracy ? 5% Aerosol Concentration Uniformity ?10% of the mean Measurement ? 5 evenly spaced isokinetic samplers...
Thelen, Mary Katherine
Coherent generation of nonclassical light on a chip via photon-induced tunneling and blockade
We report the observation of nonclassical light generated via photon blockade in a photonic crystal cavity with a strongly coupled quantum dot. By tuning the frequency of the probe laser with respect to the cavity and quantum dot resonance we can probe the system in either photon blockade or photon-induced tunneling regime. The transition from one regime to the other is confirmed by the measurement of the second order correlation that changes from anti-bunching to bunching.
Andrei Faraon; Ilya Fushman; Dirk Englund; Nick Stoltz; Pierre Petroff; Jelena Vuckovic
Types of Reuse
The following provides greater detail regarding the types of reuse pursued for LM sites. It should be noted that many actual reuses combine several types of the uses listed below.
Nonlinear tunneling of optical soliton in 3 coupled NLS equation with symbolic computation
We investigated the soliton solution for N coupled nonlinear Schr�dinger (CNLS) equations. These equations are coupled due to the cross-phase-modulation (CPM). Lax pair of this system is obtained via the Ablowitz�Kaup�Newell�Segur (AKNS) scheme and the corresponding Darboux transformation is constructed to derive the soliton solution. One and two soliton solutions are generated. Using two soliton solutions of 3 CNLS equation, nonlinear tunneling of soliton for both with and without exponential background has been discussed. Finally cascade compression of optical soliton through multi-nonlinear barrier has been discussed. The obtained results may have promising applications in all-optical devices based on optical solitons, study of soliton propagation in birefringence fiber systems and optical soliton with distributed dispersion and nonlinearity management. -- Highlights: �We consider the nonlinear tunneling of soliton in birefringence fiber. �3-coupled NLS (CNLS) equation with variable coefficients is considered. �Two soliton solutions are obtained via Darboux transformation using constructed Lax pair. �Soliton tunneling through dispersion barrier and well are investigated. �Finally, cascade compression of soliton has been achieved.
Mani Rajan, M.S., E-mail: firstname.lastname@example.com [Department of Physics, Anna University, Madurai Region, Ramanathapuram (India); Mahalingam, A. [Department of Physics, Anna University, Chennai - 600 025 (India); Uthayakumar, A. [Department of Physics, Presidency College, Chennai - 600 005 (India)
The impact of disorder on charge transport in three dimensional quantum dot resonant tunneling structures
Efficient iso-entropic energy filtering of electronic waves can be realized through nanostructures with three dimensional confinement, such as quantum dot resonant tunneling structures. Large-area deployment of such structures is useful for energy selective contacts but such configuration is susceptible to structural disorders. In this work, the transport properties of quantum-dot-based wide-area resonant tunneling structures, subject to realistic disorder mechanisms, are studied. Positional variations of the quantum dots are shown to reduce the resonant transmission peaks while size variations in the device are shown to reduce as well as broaden the peaks. Increased quantum dot size distribution also results in a peak shift to lower energy which is attributed to large dots dominating transmission. A decrease in barrier thickness reduces the relative peak height while the overall transmission increases dramatically due to lower �series resistance.� While any shift away from ideality can be intuitively expected to reduce the resonance peak, quantification allows better understanding of the tolerances required for fabricating structures based on resonant tunneling phenomena/.
Puthen-Veettil, B., E-mail: firstname.lastname@example.com; Patterson, R.; K�nig, D.; Conibeer, G.; Green, M. A. [Australian Centre for Advanced Photovoltaics, UNSW, Sydney 2052 (Australia)
Reactivation of the Shock-Tunnel Facility at Fort Cronkhite. Final report
This final report describes the results of work undertaken to reactivate the Shock Tunnel Facility at Battery Townsley, Fort Cronkhite, Marin County, California. The facility has been reactivated and can not be utilized for blast testing. The major emphasis will be testing of concepts pertaining to programs of interest to the Federal Emergency Management Agency (FEMA) and in particular to civil defense oriented research. However, a wide variety of testing requirements can be accommodated. For example, past programs at the facility have included: tests of debris from trees subjected to blast for Bell Telephone Laboratories; tests of the response of aluminum hull panels to blast loading and of the response of a model surface effects ship for the Naval Ship Research and Development center, and tests of the response of a radome prototype to blast loading conducted for ANCOM (the radome manufacturer). The Shock Tunnel Facility is located in a former coastal defense 16-inch gun emplacement constructed by the US Army beginning in 1938. It was converted in 1967 to serve as a facility for full-scale testing of the loading and response of structural elements and civil defense equipment. It remained in operation until November 1976 when Battery Townsley was turned over to the National Park Service. Work under the present purchase order consisted of the following major tasks: (I) cleanup and secure the facility, (II) reactivate the shock tunnel, and (III) design permanent facility improvements. (WHK)
Spent Fuel Transportation Package Response to the Baltimore Tunnel Fire Scenario
On July 18, 2001, a freight train carrying hazardous (non-nuclear) materials derailed and caught fire while passing through the Howard Street railroad tunnel in downtown Baltimore, Maryland. The United States Nuclear Regulatory Commission (USNRC), one of the agencies responsible for ensuring the safe transportation of radioactive materials in the United States, undertook an investigation of the train derailment and fire to determine the possible regulatory implications of this particular event for the transportation of spent nuclear fuel by railroad. Shortly after the accident occurred, the USNRC met with the National Transportation Safety Board (NTSB, the U.S. agency responsible for determining the cause of transportation accidents), to discuss the details of the accident and the ensuing fire. Following these discussions, the USNRC assembled a team of experts from the National Institute of Standards and Technology (NIST), the Center for Nuclear Waste Regulatory Analyses (CNWRA), and Pacific Northwest National Laboratory (PNNL) to determine the thermal conditions that existed in the Howard Street tunnel fire and analyze the effects of this fire on various spent fuel transportation package designs. The Fire Dynamics Simulator (FDS) code, developed by NIST, was used to determine the thermal environment present in the Howard Street tunnel during the fire. The FDS results were used as boundary conditions in the COBRA-SFS and ANSYS� computer codes to evaluate the thermal performance of different package designs. The staff concluded that larger transportation packages resembling the HOLTEC Model No. HI STAR 100 and TransNuclear Model No. TN-68 would withstand a fire with thermal conditions similar to those that existed in the Baltimore tunnel fire event with only minor damage to peripheral components. This is due to their sizable thermal inertia and design specifications in compliance with currently imposed regulatory requirements. The staff also concluded that some components of smaller transportation packages resembling the NAC Model No. LWT, despite placement within an ISO container, could degrade. USNRC staff evaluated the radiological consequences of the package responses to the Baltimore tunnel fire. Though components in some packages heated up beyond their service temperatures, the staff determined that there would be no significant dose as a result of the fire for any of these and similar packages.
Adkins, Harold E.; Cuta, Judith M.; Koeppel, Brian J.; Guzman, Anthony D.; Bajwa, Christopher S.
Conductance enhancement due to interface magnons in electron-beam evaporated MgO magnetic tunnel junctions with CoFeB free layer deposited at different pressure
Electron-beam evaporated MgO-based magnetic tunnel junctions have been fabricated with the CoFeB free layer deposited at Ar pressure from 1 to 4?mTorr, and their tunneling process has been studied as a function of temperature and bias voltage. By changing the growth pressure, the junction dynamic conductance dI/dV, inelastic electron tunneling spectrum d{sup 2}I/dV{sup 2}, and tunneling magnetoresistance vary with temperature. Moreover, the low-energy magnon cutoff energy E{sub C} derived from the conductance versus temperature curve agrees with interface magnon energy obtained directly from the inelastic electron tunneling spectrum, which demonstrates that interface magnons are involved in the electron tunneling process, opening an additional conductance channel and thus enhancing the total conductance.
Guo, P.; Yu, G. Q.; Wei, H. X.; Han, X. F., E-mail: email@example.com, E-mail: firstname.lastname@example.com [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, D. L.; Feng, J. F., E-mail: firstname.lastname@example.com, E-mail: email@example.com [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); CRANN and School of Physics, Trinity College, Dublin 2 (Ireland); Kurt, H. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland); Department of Engineering Physics, Istanbul Medeniyet University, 34720 Istanbul (Turkey); Chen, J. Y.; Coey, J. M. D. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)
Evaluate and characterize mechanisms controlling transport, fate, and effects of army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of hexachloroethane obscurant smokes
The terrestrial transport, chemical fate, and ecological effects of hexachloroethane (HC) smoke were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on exposure scenarios, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of HC smoke/obscurants is establishing the importance of environmental parameters such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and two soil types. HC aerosols were generated in a controlled atmosphere wind tunnel by combustion of hexachloroethane mixtures prepared to simulate normal pot burn rates and conditions. The aerosol was characterized and used to expose plant, soil, and other test systems. Particle sizes of airborne HC ranged from 1.3 to 2.1 {mu}m mass median aerodynamic diameter (MMAD), and particle size was affected by relative humidity over a range of 20% to 85%. Air concentrations employed ranged from 130 to 680 mg/m{sup 3}, depending on exposure scenario. Chlorocarbon concentrations within smokes, deposition rates for plant and soil surfaces, and persistence were determined. The fate of principal inorganic species (Zn, Al, and Cl) in a range of soils was assessed.
Cataldo, D.A.; Ligotke, M.W.; Bolton, H. Jr.; Fellows, R.J.; Van Voris, P.; McVeety, B.D.; Li, Shu-mei W.; McFadden, K.M.
Proposal for the award of a contract for dismantling, removal and packaging of the existing Heating, Ventilation and Air-Conditioning (HVAC) systems in the PS tunnel
Proposal for the award of a contract for dismantling, removal and packaging of the existing Heating, Ventilation and Air-Conditioning (HVAC) systems in the PS tunnel
Rock types, pore types, and hydrocarbon exploration
A proposed exploration-oriented method of classifying porosity in sedimentary rocks is based on microscopic examination cores or cuttings. Factors include geometry, size, abundance, and connectivity of the pores. The porosity classification is predictive of key petrophysical characteristics: porosity-permeability relationships, capillary pressures, and (less certainly) relative permeabilities. For instance, intercrystalline macroporosity typically is associated with high permeability for a given porosity, low capillarity, and favorable relative permeabilities. This is found to be true whether this porosity type occurs in a sucrosic dolomite or in a sandstone with pervasive quartz overgrowths. This predictive method was applied in three Rocky Mountain oil plays. Subtle pore throat traps could be recognized in the J sandstone (Cretaceous) in the Denver basin of Colorado by means of porosity permeability plotting. Variations in hydrocarbon productivity from a Teapot Formation (Cretaceous) field in the Powder River basin of Wyoming were related to porosity types and microfacies; the relationships were applied to exploration. Rock and porosity typing in the Red River Formation (Ordovician) reconciled apparent inconsistencies between drill-stem test, log, and mud-log data from a Williston basin wildcat. The well was reevaluated and completed successfully, resulting in a new field discovery. In each of these three examples, petrophysics was fundamental for proper evaluation of wildcat wells and exploration plays.
Coalson, E.B.; Hartmann, D.J.; Thomas, J.B.
Tunneling spectroscopy of superconducting MoN and NbTiN grown by atomic layer deposition
A tunneling spectroscopy study is presented of superconducting MoN and Nb{sub 0.8}Ti{sub 0.2}N thin films grown by atomic layer deposition (ALD). The films exhibited a superconducting gap of 2?meV and 2.4?meV, respectively, with a corresponding critical temperature of 11.5?K and 13.4?K, among the highest reported T{sub c} values achieved by the ALD technique. Tunnel junctions were obtained using a mechanical contact method with a Au tip. While the native oxides of these films provided poor tunnel barriers, high quality tunnel junctions with low zero bias conductance (below ?10%) were obtained using an artificial tunnel barrier of Al{sub 2}O{sub 3} on the film's surface grown ex situ by ALD. We find a large critical current density on the order of 4?�?10{sup 6}?A/cm{sup 2} at T?=?0.8T{sub c} for a 60?nm MoN film and demonstrate conformal coating capabilities of ALD onto high aspect ratio geometries. These results suggest that the ALD technique offers significant promise for thin film superconducting device applications.
Groll, Nickolas R., E-mail: email@example.com; Klug, Jeffrey A.; Claus, Helmut; Pellin, Michael J.; Proslier, Thomas, E-mail: email@example.com [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Cao, Chaoyue; Becker, Nicholas G.; Zasadzinski, John F. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Altin, Serdar [Fen Edebiyat Fakultesi, Fizik Bolumu, Inonu Universitesi, 44280 Malatya (Turkey)
Continuously-tuned tunneling behaviors of ferroelectric tunnel junctions based on BaTiO{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} heterostructure
In this work, we fabricate BaTiO{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} (BTO/LSMO) ferroelectric tunnel junction on (001) SrTiO{sub 3} substrate by pulsed laser deposition method. Combining piezoresponse force and conductive-tip atomic force microscopy, we demonstrate robust and reproducible polarization-controlled tunneling behaviors with the resulting tunneling electroresistance value reaching about 10{sup 2} in ultrathin BTO films (?1.2 nm) at room temperature. Moreover, local poling areas with different conductivity are finally achieved by controlling the relative proportion of upward and downward domains, and different poling areas exhibit stable transport properties.
Ou, Xin; Xu, Bo, E-mail: firstname.lastname@example.com; Yin, Qiaonan; Xia, Yidong; Yin, Jiang; Liu, Zhiguo [National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China)] [National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China); Gong, Changjie; Lan, Xuexin [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)] [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)
Typed Self-Optimization
type T y[O]. The operator IsIs is self-applicative, in thatargument t is any of Is[O] or IsIs, and otherwise behavesproof constant introduced by IsIs proves that the type of t
Brown, Matt
A 2-Liter, 2000 MPa Air Source for the Radiatively Driven Hypersonic Wind Tunnel
The A2 LITE is a 2 liter, 2000 MPa, 750 K ultra-high pressure (UHP) vessel used to demonstrate UHP technology and to provide an air flow for wind tunnel nozzle development. It is the largest volume UHP vessel in the world. The design is based on a 100:1 pressure intensification using a hydraulic ram as a low pressure driver and a three-layer compound cylinder UHP section. Active control of the 900 mm piston stroke in the 63.5 mm bore permits pressure-time profiles ranging from static to constant pressure during flow through a 1 mm throat diameter nozzle for 1 second.
Costantino, M; Lofftus, D
An analysis of the induced flow downstream between oscillating wings in a wind tunnel
AN ANALYSIS OF THE INDUCED FLOW DOWNSTREAM BETWEEN OSCILLATING WINGS IN A WIND TIMBAL A Thesis by BARRY ERWIN MORGAN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1970 Major Subject; Aerospace Engineering AN ANALYSIS OF THE INDUCED FLOW DOWNSTREAM BETWEEN OSCILLATING WINGS IN A WIND TUNNEL A Thesis by BARRY ERWIN MORGAN Approved as to style and content by: rman of Committee) (Hea of Depart ent...
Morgan, Barry Erwin
Eliashberg Function in an Amorphous Simple Metal Alloy Sn1-Xcux Determined by Electron-Tunneling
PHYSICAL REVIEW B VOLUME 51, NUMBER 1 1 JANUARY 1995-I Eliashberg function in an amorphous simple metal alloy Sn1 Cu determined by electron tunneling P. W. Watson III NMT-5, MS E506, Los Alamos National Laboratory, Los Alamos, New Mexico 87545... frequencies which was identical to that of Berg- mann. For very short mean free paths (high-resistivity alloys) Meisel and Cote invoked the Pippard condition in an ad hoc fashion and predicted an co dependence. The microscopic models of the electron...
WATSON, PW; Naugle, Donald G.
Spent Fuel Transportation Cask Response to the Caldecott Tunnel Fire Scenario
On April 7, 1982, a tank truck and trailer carrying 8,800 gallons of gasoline was involved in an accident in the Caldecott tunnel on State Route 24 near Oakland, California. The tank trailer overturned and subsequently caught fire. The United States Nuclear Regulatory Commission (USNRC), one of the agencies responsible for ensuring the safe transportation of radioactive materials in the United States, undertook analyses to determine the possible regulatory implications of this particular event for the transportation of spent nuclear fuel by truck. The Fire Dynamics Simulator (FDS) code developed by National Institute of Standards and Technology (NIST) was used to determine the thermal environment in the Caldecott tunnel during the fire. The FDS results were used to define boundary conditions for a thermal transient model of a truck transport cask containing spent nuclear fuel. The Nuclear Assurance Corporation (NAC) Legal Weight Truck (LWT) transportation cask was selected for this evaluation, as it represents a typical truck (over-the-road) cask, and can be used to transport a wide variety of spent nuclear fuels. Detailed analysis of the cask response to the fire was performed using the ANSYS� computer code to evaluate the thermal performance of the cask design in this fire scenario. This report describes the methods and approach used to assess the thermal response of the selected cask design to the conditions predicted in the Caldecott tunnel fire. The results of the analysis are presented in detail, with an evaluation of the cask response to the fire. The staff concluded that some components of smaller transportation casks resembling the NAC LWT, despite placement within an ISO container, could degrade significantly. Small transportation casks similar to the NAC LWT would probably experience failure of seals in this severe accident scenario. USNRC staff evaluated the radiological consequences of the cask response to the Caldecott tunnel fire. Although some components heated up beyond their service temperatures, the staff determined that there would be no significant release as a result of the fire for the NAC LWT and similar casks.
Adkins, Harold E.; Koeppel, Brian J.; Cuta, Judith M.
Quantum tunneling in ^{277}112 and its alpha-decay chain
The $\\alpha$-decay half lives of nuclei in the decay from element $^{277}112$ are calculated in a WKB framework using DDM3Y interaction and experimental Q-values. Theoretical estimation of half lives in the same quantum tunneling model, using Q-values from the mass formula of Muntian-Hofmann-Patyk-Sobiczewski, are also presented. Calculated results furnish corroborating evidence for the experimental findings at RIKEN and GSI. Certain discrepancies indicate necessity of a better mass formula. Further experimental data with higher statistics would also be useful.
C. Samanta; D. N. Basu; P. Roy Chowdhury
An application of vortex cancellation to vortex generator techniques in low speed wind tunnels
'lugs/ft-sec Axial distance between sets of vortex generators root chord lengths /Y Vertical dimension of duct cross section Tube height/Y in. none ~St i t ()i ()2 (), ( )?q Measured at station g 1 Measured at Station 0 8 Upstream srl... to accomplish these objectives. The usefulness of many of them was limited because they were either too expensive, they could not be installed easily in existing wind tunnels, or their use involved excessive energy dissipation. Vortex Generators In 1/46 a...
Mount, Glynn O., Jr
Metastable States and Macroscopic Quantum Tunneling in a Cold-Atom Josephson Ring
We study macroscopic properties of a system of weakly interacting neutral bosons confined in a ring-shaped potential with a Josephson junction. We derive an effective low energy action for this system and evaluate its properties. In particular, we find that the system possesses a set of metastable current-carrying states and evaluate the rates of transitions between these states due to macroscopic quantum tunneling and thermal activation mechanism. Finally, we discuss signatures of different metastable states in the time-of-flight images and argue that the effect is observable within currently available experimental technique.
Solenov, Dmitry; Mozyrsky, Dmitry [Theoretical Division (T-4), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Metastable states and macroscopic quantum tunneling in a cold atom josephson ring
We study macroscopic properties of a system of weakly interacting neutral bosons confined in a ring-shaped potential with a Josephson junction. We derive an effective low energy action for this system and evaluate its properties. In particular we find that the system possesses a set of metastable current-carrying states and evaluate the rates of transitions between these states due to macroscopic quantum tunneling. Finally we discuss signatures of different metastable states in the time-of-flight images and argue that the effect is observable within currently available experimental technique.
Solenov, Dmitry [Los Alamos National Laboratory; Mozyrsky, Dmitry [Los Alamos National Laboratory
Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors based on metalorganic vapor-phase epitaxy-grown epilayers
Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors, fabricated by growing p-and n-type CdTe epilayers on (211) n{sup +}-Si substrates using metalorganic vapor-phase epitaxy (MOVPE), were studied by analyzing current-voltage characteristics measured at various temperatures. The diode fabricated shows good rectification properties, however, both forward and reverse biased currents deviate from their ideal behavior. The forward current exhibits typical feature of multi-step tunneling at lower biases; however, becomes space charge limited type when the bias is increased. On the other hand, the reverse current exhibits thermally activated tunneling-type current. It was found that trapping centers at the p-CdTe/n-CdTe junction, which were formed due to the growth induced defects, determine the currents of this diode, and hence limit the performance of the nuclear radiation detectors developed.
Niraula, M.; Yasuda, K.; Wajima, Y.; Yamashita, H.; Tsukamoto, Y.; Suzuki, Y.; Matsumoto, M.; Takai, N.; Tsukamoto, Y.; Agata, Y. [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555 (Japan)] [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555 (Japan)
Temporal and Dose Kinetics of Tunnel Relaxation of Non-Equilibrium Near-Interfacial Charged Defects in Insulators
This paper is devoted mainly to mathematical aspects of modeling and simulation of tunnel relaxation of nonequilibrium charged oxide traps located at/near the interface insulator - conductive channel, for instance in irradiated MOS devices. The generic form of the tunnel annealing response function was derived from the rate equation for the charged defect buildup and annealing as a linear superposition of the responses of different defects with different time constants. Using this linear response function, a number of important practical problems are analyzed and discussed. Combined tunnel and thermal or RICN annealing, power-like temporal relaxation after a single ion strike into the gate oxide, are described in context of general approach.
Zebrev, Gennady I
Spin-polarized currents in the tunnel contact of a normal conductor and a two-dimensional topological insulator
The spin filtering of electrons tunneling from the edge states of a two-dimensional topological insulator into a normal conductor under a magnetic field (external or induced due to proximity to a magnetic insulator) is studied. Calculations are performed for a tunnel contact of finite length between the topological insulator and an electronic multimode quantum strip. It is shown that the flow of tunneling electrons is split in the strip, so that spin-polarized currents arise in its left and right branches. These currents can be effectively controlled by the contact voltage and the chemical potential of the system. The presence of a magnetic field, which splits the spin subbands of the electron spectrum in the strip, gives rise to switching of the spin current between the strip branches.
Sukhanov, A. A., E-mail: email@example.com; Sablikov, V. A. [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Fryazino branch) (Russian Federation)] [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Fryazino branch) (Russian Federation)
Electron tunneling characteristics on La[subscript 0.7]Sr[subscript 0.3]MnO[subscript 3] thin-film surfaces at high temperature
We report on the electron tunneling characteristics on La0.7Sr0.3MnO3 (LSM) thin-film surfaces up to 580?�C in 10[superscript ?3]?mbar oxygen pressure, using scanning tunneling microscopy/spectroscopy (STM/STS). A thresholdlike ...
Katsiev, Khabiboulakh
Riad, EPS Structures Innovations on Central Artery/Tunnel (CA/T) Project 2005 BSCES-GEO-INSTITUTE RECENT ADVANCES IN GEOTECHNICAL
Riad, EPS Structures Innovations on Central Artery/Tunnel (CA/T) Project 2005 BSCES-GEO-INSTITUTE RECENT ADVANCES IN GEOTECHNICAL ENGINEERING Seminar 1 EPS STRUCTURES INNOVATIONS ON CENTRAL ARTERY/TUNNEL (CA/T) PROJECT Hany L. Riad, Ph.D., P.E. (1) Abstract The use of Expanded Polystyrene (EPS) in block
Horvath, John S.
Fabrication of multilayer single-electron tunneling devices E. H. Visscher, S. M. Verbrugh, J. Lindeman, P. Hadley, and J. E. Mooij
Fabrication of multilayer single-electron tunneling devices E. H. Visscher, S. M. Verbrugh, J for the fabrication of multilevel single-electron tunneling SET devices. Using this process, we have fabricated SET. Lindeman, P. Hadley, and J. E. Mooij Department of Applied Physics and Delft Institute for Micro-Electronics
FULL-SCALE, WIND TUNNEL AND CFD WIND ENGINEERING STUDIES A variety of methods can be used to obtain wind engineering design information. These include
FULL-SCALE, WIND TUNNEL AND CFD WIND ENGINEERING STUDIES A variety of methods can be used to obtain wind engineering design information. These include codes of practice, full-scale, wind tunnel are listed in the table below: Table 1. Relative advantages and disadvantages of wind engineering techniques
Savory, Eric
Atomic and electronic structure of monolayer graphene on 6H-SiC(0001)(3 3) : a scanning tunneling microscopy study.
Atomic and electronic structure of monolayer graphene on 6H-SiC(0001)(3 � 3) : a scanning tunneling of the atomic and electronic structure of graphene monolayer islands on the 6H-SiC(0001)(3�3) (SiC(3�3)) surface reconstruction using scanning tunneling microscopy (STM) and spectroscopy (STS). The orientation of the graphene
Paris-Sud XI, Universit� de
Danger of Tunnels on Al Aqsa Mosque Buildings For more than 40 years, the city of Jerusalem has faced accelerated historical transformation on
Danger of Tunnels on Al Aqsa Mosque Buildings Abstract For more than 40 years, the city tunnels under Al Aqsa Mosque and the Arab historical town to weaken the foundation of buildings. This research highlights Palestinian, Israeli and international important reports about the excavations under Al
Proximity detector circuits: an attractive alternative to tunnel diode oscillators for contactless measurements in pulsed magnetic fields
A new radio frequency oscillator circuit based on a proximity detector integrated circuit is described as an alternative for the traditional tunnel diode oscillator used for pulsed magnetic field measurements at low temperatures. The new circuit has been successfully applied to measure the superconducting upper critical field in Ba{sub 0.55}K{sub 0.45}Fe{sub 2}As{sub 2} single crystfl.ls up to 60 T. The new circuit design avoids many of the problems associated with tunnel diode circuits while keeping the advantages of contact less measurements in pulsed magnets.
Altarawneh, Moaz M [Los Alamos National Laboratory; Mielke, Charles H [Los Alamos National Laboratory
Corrected entropy of the rotating black hole solution of the new massive gravity using the tunneling method and Cardy formula
We study the AdS rotating black hole solution for the Bergshoeff-Hohm-Townsend massive gravity in three dimensions. The field equations of the asymptotically AdS black hole of the static metric can be expressed as the first law of thermodynamics, i.e. dE=TdS-PdV. The corrected Hawking-like temperature and entropy of the asymptotically AdS rotating black hole are calculated using the Cardy formula and the tunneling method. Comparison of these methods will help identify the unknown leading correction parameter {beta}{sub 1} in the tunneling method.
Mirza, Behrouz; Sherkatghanad, Zeinab [Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)
Low-temperature magnetic characterization of optimum and etch-damaged in-plane magnetic tunnel junctions
We describe low-temperature characterization of magnetic tunnel junctions (MTJs) patterned by reactive ion etching for spin-transfer-torque magnetic random access memory. Magnetotransport measurements of typical MTJs show increasing tunneling magnetoresistance (TMR) and larger coercive fields as temperature is decreased down to 10 K. However, MTJs selected from the high-resistance population of an MTJ array exhibit stable intermediate magnetic states when measured at low temperature and show TMR roll-off below 100 K. These non-ideal low-temperature behaviors arise from edge damage during the etch process and can have negative impacts on thermal stability of the MTJs.
Kan, Jimmy J.; Gottwald, Matthias; Fullerton, Eric E. [Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States)] [Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States); Lee, Kangho; Kang, Seung H. [Advanced Technology, Qualcomm, Inc., San Diego, California 92121 (United States)] [Advanced Technology, Qualcomm, Inc., San Diego, California 92121 (United States)
Natural convection in tunnels at Yucca Mountain and impact on drift seepage
The decay heat from radioactive waste that is to be disposed in the once proposed geologic repository at Yucca Mountain (YM) will significantly influence the moisture conditions in the fractured rock near emplacement tunnels (drifts). Additionally, large-scale convective cells will form in the open-air drifts and will serve as an important mechanism for the transport of vaporized pore water from the fractured rock in the drift center to the drift end. Such convective processes would also impact drift seepage, as evaporation could reduce the build up of liquid water at the tunnel wall. Characterizing and understanding these liquid water and vapor transport processes is critical for evaluating the performance of the repository, in terms of water-induced canister corrosion and subsequent radionuclide containment. To study such processes, we previously developed and applied an enhanced version of TOUGH2 that solves for natural convection in the drift. We then used the results from this previous study as a time-dependent boundary condition in a high-resolution seepage model, allowing for a computationally efficient means for simulating these processes. The results from the seepage model show that cases with strong natural convection effects are expected to improve the performance of the repository, since smaller relative humidity values, with reduced local seepage, form a more desirable waste package environment.
Halecky, N.; Birkholzer, J.T.; Peterson, P.
The tunneling model of laser-induced ionization and its failure at low frequencies
The tunneling model of ionization applies only to longitudinal fields: quasistatic electric fields that do not propagate. Laser fields are transverse: plane wave fields that possess the ability to propagate. Although there is an approximate connection between the effects of longitudinal and transverse fields in a useful range of frequencies, that equivalence fails completely at very low frequencies. Insight into this breakdown is given by an examination of radiation pressure, which is a unique transverse-field effect whose relative importance increases rapidly as the frequency declines. Radiation pressure can be ascribed to photon momentum, which does not exist for longitudinal fields. Two major consequences are that the near-universal acceptance of a static electric field as the zero frequency limit of a laser field is not correct; and that the numerical solution of the dipole-approximate Schr\\"{o}dinger equation for laser effects is inapplicable as the frequency declines. These problems occur because the magnetic component of the laser field is very important at low frequencies, and hence the dipole approximation is not valid. Some experiments already exist that demonstrate the failure of tunneling concepts at low frequencies.
H. R. Reiss
Josephson scanning tunneling microscopy -- a local and direct probe of the superconducting order parameter
Direct measurements of the superconducting superfluid on the surface of vacuum-cleaved Bi2Sr2CaCu2O8+delta (BSCCO) samples are reported. These measurements are accomplished via Josephson tunneling into the sample using a novel scanning tunneling microscope (STM) equipped with a superconducting tip. The spatial resolution of the STM of lateral distances less than the superconducting coherence length allows it to reveal local inhomogeneities in the pair wavefunction of the BSCCO. Instrument performance is demonstrated first with Josephson measurements of Pb films followed by the layered superconductor NbSe2. The relevant measurement parameter, the Josephson ICRN product, is discussed within the context of both BCS superconductors and the high transition temperature superconductors. The local relationship between the ICRN product and the quasiparticle density of states (DOS) gap are presented within the context of phase diagrams for BSCCO. Excessive current densities can be produced with these measurements and have been found to alter the local DOS in the BSCCO. Systematic studies of this effect were performed to determine the practical measurement limits for these experiments. Alternative methods for preparation of the BSCCO surface are also discussed.
Kimura, Hikari; Dynes, Robert; Barber Jr., Richard. P.; Ono, S.; Ando, Y.
Patency of Femoral Tunneled Hemodialysis Catheters and Factors Predictive of Patency Failure
Purpose: To determine the patency rates of and factors associated with increased risk of patency failure in patients with femoral vein tunneled hemodialysis catheters. Methods: All femoral tunneled catheter insertions from 1996 to 2006 were reviewed, during which time 123 catheters were inserted. Of these, 66 were exchanges. Patients with femoral catheter failure versus those with femoral catheter patency were compared. Confounding factors, such as demographic and procedural factors, were incorporated and assessed using univariate and multivariable Cox proportional hazards regression analyses. Results: Mean catheter primary patency failure time was 96.3 days (SE 17.9 days). Primary patency at 30, 60, 90, and 180 days was 53.8%, 45.4%, 32.1%, and 27.1% respectively. Crude rates of risk of catheter failure did not suggest a benefit for patients receiving catheters introduced from one side versus the other, but more cephalad location of catheter tip was associated with improved patency. Multivariate analysis showed that patients whose catheters were on the left side (p = 0.009), were of increasing age at the time of insertion (p = 0.002) and that those who had diabetes (p = 0.001) were at significantly greater risk of catheter failure. The catheter infection rate was 1.4/1000 catheter days. Conclusion: Patients who were of a more advanced age and had diabetes were at greater risk of femoral catheter failure, whereas those who received femoral catheters from the right side were less at risk of catheter failure.
Burton, Kirsteen R. [University Health Network, University of Toronto, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada); Guo, Lancia L. Q. [University of Calgary, Department of Radiology (Canada); Tan, Kong T.; Simons, Martin E.; Sniderman, Kenneth W.; Kachura, John R.; Beecroft, John R.; Rajan, Dheeraj K., E-mail: email@example.com [University Health Network, University of Toronto, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada)
Document Type: Subject Terms
Title: Authors: Source: Document Type: Subject Terms: Abstract: Full Text Word Count: ISSN at creating team results. In fact, it's priceless. Managers in Western corporations have received a lifetime
Major, Arkady
Faraday Discuss., 1994,97,35-41 Far-IR Vibration-Rotation-Tunnelling Spectroscopy of the
. The theoretical equi- librium geometry of the water trimer is a hydrogen-bonded ring in which each water acts' is accomplished by rotating one water monomer (shaded) about its donated hydrogen bond. The pathway connectsFaraday Discuss., 1994,97,35-41 Far-IR Vibration-Rotation-Tunnelling Spectroscopy of the Water
Adapting to Limitations of a Wind Tunnel Test Facility in the Aerodynamic Testing of a new UAV
Adapting to Limitations of a Wind Tunnel Test Facility in the Aerodynamic Testing of a new UAV Dr K section for aerodynamic tests of aircraft models and aerodynamic devices. Improvements over the years have aerodynamic testing facility, albeit with much reduced capability. This paper reports on initial progress
Wong, K. C.
L-Cysteine Adsorption Structures on Au(111) Investigated by Scanning Tunneling Microscopy under Ultrahigh Vacuum Conditions
to 380 K lead to marked changes in the observed adsorption structures. At low coverages, the unordered containing pH- controlling buffer salts and with or without electrochemical control, to vapor deposition. The primary characterization techniques have been in situ electrochemical scanning tunneling microscopy (STM
Kühnle, Angelika
Direct observation of electron emission from the grain boundaries of chemical vapour deposition diamond films by tunneling atomic force microscopy
.1063/1.3475506 Direct observation of electron emission site on boron-doped polycrystalline diamond thin films using or energy harvesting devices. Electron emission studies usually use doped polycrystalline diamond films observation of the emission sites over a large area of polycrystalline diamond using tunneling atomic force
Bristol, University of
Electrically Tunable Macroscopic Quantum Tunneling in a Graphene-Based Josephson Junction Gil-Ho Lee,1
Electrically Tunable Macroscopic Quantum Tunneling in a Graphene-Based Josephson Junction Gil.1103/PhysRevLett.107.146605 PACS numbers: 72.80.Vp, 73.40.�?c, 74.45.+c, 85.25.Cp A Josephson junction [1 the fabri- cation of nanostructured proximity-coupled Josephson junctions based on conducting spacers
Lee, Hu-Jong
Scanning tunneling spectroscopy on crossed carbon nanotubes J. W. Janssen, S. G. Lemay, L. P. Kouwenhoven, and C. Dekker
the nanotubes and their binding energy to a supporting gold substrate. More importantly, our STS studies showScanning tunneling spectroscopy on crossed carbon nanotubes J. W. Janssen, S. G. Lemay, L. P Delft, The Netherlands Received 3 October 2001; published 8 March 2002 Crossing nanotubes were
Low Speed Virtual Wind Tunnel Simulation For Educational Studies In Introducing Computational Fluid Dynamics And Flow Visualization
............................................................................................................... 25 3.2.4. Starting FlowLab ...................................................................................................................... 26 3.2.5. Geometry Settings... OF THE PROGRAMMING....................................................................... 52 v List of Figures FIGURE 2.1 ? COST AND TIME RELATIONSHIP WITH RESPECT TO CFD AND WIND TUNNELS............................. 5 FIGURE 2.2 - BOEING 777 DESIGN...
Yang, Cher-Chiang
Patient-specific hemodynamic performance of Fontan conversion templates: Lateral tunnel vs. intra-atrial with fenestration
. Results: Power loss inside the lateral tunnel Fontan appeared significantly higher than the intra-averaged power loss for both Fontan connections. Flow-structures within the intra-atrial conduit were notability connections: LT-to-IAC Fontan conversion resulted better hemodynamics with less power loss, pressure gradient
Pekkan, Kerem
Scanning tunneling microscope tip as a positionable contact: Probing a Josephson-junction array at subkelvin temperatures
Scanning tunneling microscope tip as a positionable contact: Probing a Josephson-junction arrayK. The STM enables us to probe the structure, a Josephson-junction array, at various positions. Examples of such systems are two- dimensional electron gases and Josephson junction arrays.1
Attributable Risk of Carpal Tunnel Syndrome in the General Population: Implications for Intervention Programs in the Workplace
sponsor. Word count text: 3182 excluding Abstract, References and Tables Word count Abstract: 224; Tables: 2 inserm-00425478,version1-9Feb2011 Author manuscript, published in "Scandinavian journal of work, environment & health 35, 5 (2009) 342-8" #12;2 ABSTRACT: Objectives Carpal tunnel syndrome (CTS) represents
THE JOURNAL OF CHEMICAL PHYSICS 139, 244307 (2013) Electron tunneling characteristics of a cubic quantum dot, (PbS)32
distribution at the Fermi level seem to determine the tunneling characteristics of the system. © 2013 AIP been of a special interest due to their potential applications in IR photo-detection, photovoltaics-gap controlled PbS nanocrystals of various sizes were synthesized to study the effect of band- gap energy
Pandey, Ravi
Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene/Ru(0001) Heterostructures
Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene on graphene/Ru(0001) were used to study the corrugation of the moire structure of graphene/Ru(0001 for the graphene/Ru(0001) moire is of structural nature rather than electronic. STM showed a large value
Ciobanu, Cristian
Concept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D sonic anemometer
comparable potential. Wind measurements on wind turbines in undisturbed wind, relative to nacelle anemometryConcept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D" by CFD calculations Spinner AnemometrySpinner Anemometry -- An Innovative Wind Measurement Concept
Health and safety evaluation of a modified tunnel-borer design for application to single-entry coal-mine development
The health and safety analysis is part of an overall effort to identify and develop innovative underground coal extraction systems. The single-entry tunnel borer system was initially considered an innovative approach to underground mining because it exhibited a means of increasing the speed and efficiency of entry development by reducing the number of entries. However, to be considered a truly advanced system, the tunnel borer had to meet distinct safety criteria as well. The objective was to examine the tunnel borer design and determine whether it offset major health hazards, and satisfied the prescribed safety levels. As a baseline for comparison, the tunnel borer was compared against the continuous mining entry driving system. The results of the health analysis indicated that while the tunnel borer design offered improvements in dust control through the use of water sprays, a higher face ventilation rate, and the application of spalling rather than the conventional grinding process, it interjected an additional mutagenic is and toxic compound into the environment through the use of shotcrete. The tunnel borer system easily conformed with the prescribed fatality limit, but exceeded the required limits for disabling and overall injuries. It also exhibited projected disabling and overall injury rates considerably higher than existing continuous mining injury rates. Consequently, the tunnel borer system was not considered an advanced system.
Zimmerman, W. F.
Method and apparatus for differential spectroscopic atomic-imaging using scanning tunneling microscopy
A Method and apparatus for differential spectroscopic atomic-imaging is disclosed for spatial resolution and imaging for display not only individual atoms on a sample surface, but also bonding and the specific atomic species in such bond. The apparatus includes a scanning tunneling microscope (STM) that is modified to include photon biasing, preferably a tuneable laser, modulating electronic surface biasing for the sample, and temperature biasing, preferably a vibration-free refrigerated sample mounting stage. Computer control and data processing and visual display components are also included. The method includes modulating the electronic bias voltage with and without selected photon wavelengths and frequency biasing under a stabilizing (usually cold) bias temperature to detect bonding and specific atomic species in the bonds as the STM rasters the sample. This data is processed along with atomic spatial topography data obtained from the STM raster scan to create a real-time visual image of the atoms on the sample surface.
Kazmerski, Lawrence L. (Lakewood, CO)
Giant electrocaloric effect in asymmetric ferroelectric tunnel junctions at room temperature
Room-temperature electrocaloric properties of Pt/BaTiO{sub 3}/SrRuO{sub 3} ferroelectric tunnel junctions (FTJs) are studied by using a multiscale thermodynamic model. It is found that there is a divergence in the adiabatic temperature change ?T for the two opposite polarization orientations. This difference under a typical writing voltage of 3?V can reach over 1?K as the barrier thickness decreases. Thanks to the ultrahigh external stimulus, a giant electrocaloric effect (1.53?K/V) with ?T being over 4.5?K can be achieved at room temperature, which demonstrates the perspective of FTJs as a promising solid-state refrigeration.
Liu, Yang, E-mail: firstname.lastname@example.com; Infante, Ingrid C.; Dkhil, Brahim, E-mail: email@example.com [Laboratoire Structures, Propri�t�s et Mod�lisation des Solides, UMR 8580 CNRS-Ecole Centrale Paris, Grande Voie des Vignes, Ch�tenay-Malabry Cedex 92295 (France); Lou, Xiaojie [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049 (China)
A High Luminosity e+e- Collider in the LHC tunnel to study the Higgs Boson
We consider the possibility of a 120x120 GeV e+e- ring collider in the LHC tunnel. A luminosity of 10^34/cm2/s can be obtained with a luminosity life time of a few minutes. A high operation efficiency would require two machines: a low emittance collider storage ring and a separate accelerator injecting electrons and positrons into the storage ring to top up the beams every few minutes. A design inspired from the high luminosity b-factory design and from the LHeC design report is presented. Statistics of over 10^4 HZ events per year per experiment can be contemplated for a Standard Higgs Boson mass of 115-130 GeV.
Alain Blondel; Frank Zimmermann
Tunneling density of states as a function of thickness in superconductor/ strong ferromagnet bilayers
We have made an experimental study of the tunneling density of states (DOS) in strong ferromagnetic thin films (CoFe) in proximity with a thick superconducting film (Nb) as a function of d{sub F}, the ferromagnetic thickness. Remarkably, we find that as d{sub F} increases, the superconducting DOS exhibits a scaling behavior in which the deviations from the normal-state conductance have a universal shape that decreases exponentially in amplitude with characteristic length d* {approx} 0.4 nm. We do not see oscillations in the DOS as a function of d{sub F}, as expected from predictions based on the Usadel equations, although an oscillation in T{sub c}(d{sub F}) has been seen in the same materials.
Reymond, S.
Tunneling, decoherence, and entanglement of two spins interacting with a dissipative bath
We use numerically exact iterative path integral methods to investigate the decoherence and entanglement dynamics of a tunneling pair of two coupled qubits (spins) system interacting with a dissipative bath. We find that decoherence is generally accompanied by the destruction of entanglement, although the specifics of this destruction depend sensitively on the parameters of the Hamiltonian (qubit-qubit coupling and/or energy bias), the strength of dissipation, the temperature, and the choice of initial condition. We also observe that dissipation can in some cases generate a substantial amount of entanglement. Finally, if an entangled eigenstate exists which does not couple to the environment, the long-time entanglement can significantly exceed the value corresponding to the Boltzmann equilibrium state.
Sahrapour, Mohammad M. [Department of Physics, University of Illinois, 1110 W. Green Street, Urbana, Illinois 61801 (United States); Makri, Nancy [Department of Physics, University of Illinois, 1110 W. Green Street, Urbana, Illinois 61801 (United States); Department of Chemistry, University of Illinois, 600 S. Goodwin Avenue, Urbana, Illinois 61801 (United States)
Black hole fireworks: quantum-gravity effects outside the horizon spark black to white hole tunneling
We show that there is a classical metric satisfying the Einstein equations outside a finite spacetime region where matter collapses into a black hole and then emerges from a white hole. We compute this metric explicitly. We show how quantum theory determines the (long) time for the process to happen. A black hole can thus quantum-tunnel into a white hole. For this to happen, quantum gravity should affect the metric also in a small region outside the horizon: we show that contrary to what is commonly assumed, this is not forbidden by causality or by the semiclassical approximation, because quantum effects can pile up over a long time. This scenario alters radically the discussion on the black hole information puzzle.
Hal M. Haggard; Carlo Rovelli
Electrical spin injection into InGaAs/GaAs quantum wells: A comparison between MgO tunnel barriers grown by sputtering and molecular beam epitaxy methods
An efficient electrical spin injection into an InGaAs/GaAs quantum well light emitting diode is demonstrated thanks to a CoFeB/MgO spin injector. The textured MgO tunnel barrier is fabricated by two different techniques: sputtering and molecular beam epitaxy. The maximal spin injection efficiency is comparable for both methods. Additionally, the effect of annealing is also investigated for the two types of samples. Both samples show the same trend: an increase of the electroluminescence circular polarization (P{sub c}) with the increase of annealing temperature, followed by a saturation of P{sub c} beyond 350?�C annealing. Since the increase of P{sub c} starts well below the crystallization temperature of the full CoFeB bulk layer, this trend could be mainly due to an improvement of chemical structure at the top CoFeB/MgO interface. This study reveals that the control of CoFeB/MgO interface is essential for an optimal spin injection into semiconductor.
Barate, P.; Zhang, T. T.; Vidal, M.; Renucci, P.; Marie, X.; Amand, T. [Universit� de Toulouse, INSA-CNRS-UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse (France); Liang, S.; Devaux, X.; Hehn, M.; Mangin, S.; Lu, Y., E-mail: firstname.lastname@example.com [Institut Jean Lamour, UMR 7198, CNRS-Nancy Universit�, BP 239, 54506 Vandoeuvre (France); Frougier, J.; Jaffr�s, H.; George, J. M. [Unit� Mixte de Physique CNRS/Thales and Universit� Paris-Sud 11, 1 avenue A. Fresnel, 91767 Palaiseau (France); Xu, B.; Wang, Z. [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P. O. Box 912, Beijing 100083 (China); Zheng, Y. [Institut des NanoSciences de Paris, UPMC, CNRS UMR 7588, 4 place Jussieu, 75005 Paris (France); Tao, B. [Institut Jean Lamour, UMR 7198, CNRS-Nancy Universit�, BP 239, 54506 Vandoeuvre (France); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China); Han, X. F. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China)
Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures
Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365?nm (3.4?eV, the bulk bandgap) to below 240?nm (>5.2?eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.
Verma, Jai, E-mail: email@example.com; Islam, S. M.; Protasenko, Vladimir; Kumar Kandaswamy, Prem; Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
Scanning Josephson Tunneling Microscopy of Single Crystal Bi2Sr2CaCu2O8+delta with a Conventional Superconducting Tip
We have performed both Josephson and quasiparticle tunneling in vacuum tunnel junctions formed between a conventional superconducting scanning tunneling microscope tip and overdoped Bi2Sr2CaCu2O8+ single crystals. A Josephson current is observed with a peak centered at a small finite voltage due to the thermal-fluctuation-dominated superconducting phase dynamics. Josephson measurements at different surface locations yield local values for the Josephson ICRN product. Corresponding energy gap measurements were also performed and a surprising inverse correlation was observed between the local ICRN product and the local energy gap.
Kimura, H.; Barber Jr., R. P.; Ono, S.; Ando, Yoichi; Dynes, Robert C.
Evaluate and characterize mechanisms controlling transport, fate and effects of army smokes in an aerosol wind tunnel: Transport, transformations, fate and terrestrial ecological effects of fog oil obscurant smokes: Final report
The terrestrial transport, chemical fate, and ecological effects of fog oil (FO) smoke obscurants were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on an exposure scenario, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of fog oil smoke/obscurants is establishing the importance of environmental parameters, such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and three soil types. 29 refs., 35 figs., 32 tabs.
Cataldo, D.A.; Van Voris, P.; Ligotke, M.W.; Fellows, R.J.; McVeety, B.D.; Li, Shu-mei W.; Bolton, H. Jr.; Fredrickson, J.K.
Dust around Type Ia supernovae
Dust around Type Ia supernovae Lifan Wang 1,2 LawrenceIa. Subject headings: Supernovae: General, Dust, Extinctionline) bands for Type Ia supernovae. (a), upper panel, shows
Wang, Lifan
Wolter type i LAMAR
Observational objectives for the LAMAR and their influence on the instrument design are discussed. It is concluded that the most important design parameter is the angular resolution of the LAMAR modules since it so strongly influences sensitivity, optical identifications, source confusion, spectral resolution for objective gratings and the ability to resolve small extended sources. A high resolution Wolter Type I LAMAR module is described, its hardware status discussed, and the performance of a LAMAR observatory presented. A promising technique for enhancing the reflectivity of Wolter Type I X-ray optics in a selected bandpass at high energy has been investigated and the performance of the LAMAR module, utilizing this method, has been calculated.
Catura, R.C.; Joki, E.G.
Definitions: Types of Commissioning
Workshop on the Continuous Commissioning� Process Joseph T. Martinez, PCC Carlos Yagua, PE Hiroko Masuda, Juan-Carlos Baltazar, PhD, PE Ahmet Ugursal, PhD Clean Air Through Energy Efficiency (CATEE) Conference, Dallas, Texas. November 18, 2014... 5. Continuous Commissioning Measures 6. Measurement and Verification ESL-KT-14-11-41 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Definitions: Types of Commissioning Joseph T. Martinez, PCC Carlos Yagua, PE Hiroko...
Martinez, J. T.
Forecast Technical Document Forecast Types
Forecast Technical Document Forecast Types A document describing how different forecast types are implemented in the 2011 Production Forecast system. Tom Jenkins Robert Matthews Ewan Mackie Lesley Halsall #12;PF2011 Forecast Types Background Different `types' of forecast are possible for a specified area
Investigation on edge fringing effect and oxide thickness dependence of inversion current in metal-oxide-semiconductor tunneling diodes with comb-shaped electrodes
A particular edge-dependent inversion current behavior of metal-oxide-semiconductor (MOS) tunneling diodes was investigated utilizing square and comb-shaped electrodes. The inversion tunneling current exhibits the strong dependence on the tooth size of comb-shaped electrodes and oxide thickness. Detailed illustrations of current conduction mechanism are developed by simulation and experimental measurement results. It is found that the electron diffusion current and Schottky barrier height lowering for hole tunneling current both contribute on inversion current conduction. In MOS tunneling photodiode applications, the photoresponse can be improved by decreasing SiO{sub 2} thickness and using comb-shaped electrodes with smaller tooth spacing. Meantime, the high and steady photosensitivity can also be approached by introducing HfO{sub 2} into dielectric stacks.
Lin, Chien-Chih; Hsu, Pei-Lun; Lin, Li; Hwu, Jenn-Gwo, E-mail: email@example.com [Graduate Institute of Electronics Engineering, Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)
Methane dissociative chemisorption and detailed balance on Pt(111): Dynamical constraints and the modest influence of tunneling
A dynamically biased (d-) precursor mediated microcanonical trapping (PMMT) model of the activated dissociative chemisorption of methane on Pt(111) is applied to a wide range of dissociative sticking experiments, and, by detailed balance, to the methane product state distributions from the thermal associative desorption of adsorbed hydrogen with coadsorbed methyl radicals. Tunneling pathways were incorporated into the d-PMMT model to better replicate the translational energy distribution of the desorbing methane product from the laser induced thermal reaction of coadsorbed hydrogen and methyl radicals occurring near T{sub s} = 395 K. Although tunneling is predicted to be inconsequential to the thermal dissociative chemisorption of CH{sub 4} on Pt(111) at the high temperatures of catalytic interest, once the temperature drops to 395 K the tunneling fraction of the reactive thermal flux reaches 15%, and as temperatures drop below 275 K the tunneling fraction exceeds 50%. The d-PMMT model parameters of (E{sub 0} = 58.9?kJ/mol,?s = 2,??{sub v} = 0.40) describe the apparent threshold energy for CH{sub 4}/Pt(111) dissociative chemisorption, the number of surface oscillators involved in the precursor complex, and the efficacy of molecular vibrational energy to promote reaction, relative to translational energy directed along the surface normal. Molecular translations parallel to the surface and rotations are treated as spectator degrees of freedom. Transition state vibrational frequencies are derived from generalized gradient approximation-density functional theory electronic structure calculations. The d-PMMT model replicates the diverse range of experimental data available with good fidelity, including some new effusive molecular beam and ambient gas dissociative sticking measurements. Nevertheless, there are some indications that closer agreement between theory and experiments could be achieved if a surface efficacy less than one was introduced into the modeling as an additional dynamical constraint.
Donald, S. B.; Navin, J. K.; Harrison, I., E-mail: email@example.com [Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319 (United States)
Low-temperature scanning tunneling microscopy and transport measurements on adsorbate-induced two-dimensional electron systems
We have performed not only magnetotransport measurements on two-dimensional electron systems (2DESs) formed at the cleaved surfaces of p-InAs but also observations of the surface morphology of the adsorbate atoms, which induced the 2DES at the surfaces of narrow band-gap semiconductors, with use of a scanning tunneling microscopy. The electron density of the 2DESs is compared to the atomic density of the isolated Ag adatoms on InAs surfaces.
Masutomi, Ryuichi; Triyama, Naotaka; Okamoto, Tohru [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
Resistive switching of a TaO{sub x}/TaON double layer via ionic control of carrier tunneling
Resistance random access memory (RRAM) is an attractive candidate for future non-volatile memory due to its superior features. As the oxide thickness is scaled down, the charge transport mechanism is also subject to the transition from hopping to tunneling dominant process, which is critically related to the interfacial electronic band structure. A TaO{sub x}/TaON double layer-based RRAM is fabricated and characterized in this work. Upon TaON insertion at the lower interface, the improved switching behavior is observed. The TaON at the bottom electrode interface blocks oxygen vacancy percolation due to strong N-O bonds and also modifies interfacial band alignment to lower the injected electron energy from bottom electrode due to higher tunneling barrier height than that of TaO{sub x}/Pt. This study suggested that a defect-minimized insertion layer like TaON with a proper interfacial band alignment is pivotal in RRAM for the effective ionic control of carrier tunneling resulting in non-linear I-V behavior with improved properties.
Jeon, Heeyoung; Park, Jingyu; Kim, Hyunjung [Department of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jang, Woochool; Song, Hyoseok [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kang, Chunho [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); FAB Manufacturing Division, SK Hynix Inc., 2091, Gyeongchung-daero, Bubal-eub, Icheon-si, Gyeonggi-do 167-701 (Korea, Republic of); Seo, Hyungtak, E-mail: email@example.com [Department of Materials Science and Engineering and Department of Energy Systems Research, Ajou University, Suwon 443-739 (Korea, Republic of); Jeon, Hyeongtag, E-mail: email@example.com [Department of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)
Entropy is conserved in Hawking radiation as tunneling: A revisit of the black hole information loss paradox
Research Highlights: > Information is found to be encoded and carried away by Hawking radiations. > Entropy is conserved in Hawking radiation. > We thus conclude no information is lost. > The dynamics of black hole may be unitary. - Abstract: We revisit in detail the paradox of black hole information loss due to Hawking radiation as tunneling. We compute the amount of information encoded in correlations among Hawking radiations for a variety of black holes, including the Schwarzchild black hole, the Reissner-Nordstroem black hole, the Kerr black hole, and the Kerr-Newman black hole. The special case of tunneling through a quantum horizon is also considered. Within a phenomenological treatment based on the accepted emission probability spectrum from a black hole, we find that information is leaked out hidden in the correlations of Hawking radiation. The recovery of this previously unaccounted for information helps to conserve the total entropy of a system composed of a black hole plus its radiations. We thus conclude, irrespective of the microscopic picture for black hole collapsing, the associated radiation process: Hawking radiation as tunneling, is consistent with unitarity as required by quantum mechanics.
Zhang Baocheng [State Key Laboratory of Magnetic Resonances and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Cai Qingyu, E-mail: firstname.lastname@example.com [State Key Laboratory of Magnetic Resonances and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Zhan Mingsheng [State Key Laboratory of Magnetic Resonances and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071 (China); You Li [Department of Physics, Tsinghua University, Beijing 100084 (China)
E-Print Network 3.0 - antiperovskite-type superconductor formula...
Digital Electronics: Optimizing the speed of a Summary: , Georgetown University, Josephson Junction talk, 2000 12;Josephson Tunnel Junctions A Superconductor......
Investigation of physico-chemical processes in hypervelocity MHD-gas acceleration wind tunnels
The calculation results for nonequilibrium physicochemical processes in the circuit of the hypersonic MHD-gas acceleration wind tunnel are presented. The flow in the primary nozzle is shown to be in thermodynamic equilibrium at To=3400 K, Po=(2{approximately}3)x10{sup 5} Pa, M=2 used in the plenum chamber. Variations in the static pressure due to oxidation reaction of Na, K are pointed out. The channels of energy transfer from the electric field to different degrees of freedom of an accelerated gas with Na, K seeds are considered. The calculation procedure for gas dynamic and kinetic processes in the MHD-channel using measured parameters is suggested. The calculated results are compared with the data obtained in a thermodynamic gas equilibrium assumption. The flow in the secondary nozzle is calculated under the same assumptions and the gas parameters at its exit are evaluated. Particular attention is given to the influence of seeds on flows over bodies. It is shown that the seeds exert a very small influence on the flow behind a normal shock wave. The seeds behind an oblique shock wave accelerate deactivation of vibrations of N{sub 2}, but this effect is insignificant.
Alfyorov, V.I.; Dmitriev, L.M.; Yegorov, B.V.; Markachev, Yu.E. [Central Aerohydrodynamic Institute (TsAGI), Zhukovsky (Russian Federation)
Scanning tunneling microscopy study of nitrogen incorporated HfO{sub 2}
The impact of nitrogen incorporation on the physical and electrical characteristics of the HfO{sub 2} is examined. X-ray photoelectron spectroscopy shows that nitrogen can be incorporated into the HfO{sub 2} via a two-step thermal anneal--first in ultrahigh vacuum (UHV) and subsequently in N{sub 2}. Following the N{sub 2} anneal, scanning tunneling microscopy in UHV reveals a marked reduction in the low-voltage leakage current under gate injection biasing. From band theory and existing first-principles simulation results, one may consistently attribute this improvement to the passivation of oxygen vacancies in the HfO{sub 2} by nitrogen. Improvement in the breakdown strength of the HfO{sub 2} subjected to ramp-voltage stress (substrate injection) is also observed after the N{sub 2} anneal. The local current-voltage curves acquired concurrently during the ramp-voltage stress exhibit 'space-charge limited conduction', which implies that the observed improvement in breakdown strength may be related to a limitation of the current flow through the gate stack in the high stress voltage regime.
Ong, Y. C.; Ang, D. S.; Pey, K. L.; Li, X. [Nanyang Technological University, School of Electrical and Electronic Engineering, Nanyang Avenue, Singapore 639798 (Singapore); O'Shea, S. J.; Wang, S. J. [Institute of Materials Research and Engineering, A-STAR - Agency for Science, Technology and Research, 3 Research Link, Singapore 11760 (Singapore); Tung, C. H. [Institute of Microelectronics, A-STAR - Agency for Science, Technology and Research, 11 Science Park Road, Singapore Science Park II, Singapore 117685 (Singapore)
Quantum dynamics and macroscopic quantum tunneling of two weakly coupled condensates
We study the quantum dynamics of a Bose Josephson junction(BJJ) made up of two coupled Bose-Einstein condensates. Apart from the usual ac Josephson oscillations, two different dynamical states of BJJ can be observed by tuning the inter-particle interaction strength, which are known as '$\\pi$-oscillation' with relative phase $\\pi$ between the condensates and 'macroscopic self-trapped' (MST) state with finite number imbalance. By choosing appropiate intial state we study above dynamical branches quantum mechanically and compare with classical dynamics. The stability region of the '$\\pi$-oscillation' is separated from that of 'MST' state at a critical coupling strength. Also a significant change in the energy spectrum takes place above the critical coupling strength, and pairs of (quasi)-degenerate excited states appear. The original model of BJJ can be mapped on to a simple Hamiltonian describing quantum particle in an 'effective potential' with an effective Planck constant. Different dynamical states and degenerate excited states in the energy spectrum can be understood in this 'effective potential' approach. Also possible novel quantum phenomena like 'macroscopic quantum tunneling'(MQT) become evident from the simple picture of 'effective potential'. We study decay of metastable '$\\pi$-oscillation' by MQT through potential barrier. The doubly degenerate excited states in the energy spectrum are associated with the classically degenerate MST states with equal and opposite number imbalance. We calculate the energy splitting between these quasi-degenerate excited states due to MQT of the condensate between classically degenerate MST states.
Ren� John Kerkdyk; S. Sinha
Design, fabrication, and analysis of p-channel arsenide/antimonide hetero-junction tunnel transistors
In this paper, we demonstrate InAs/GaSb hetero-junction (hetJ) and GaSb homo-junction (homJ) p-channel tunneling field effect transistors (pTFET) employing a low temperature atomic layer deposited high-? gate dielectric. HetJ pTFET exhibited drive current of 35 ?A/?m in comparison to homJ pTFET, which exhibited drive current of 0.3 ?A/?m at V{sub DS}?=??0.5?V under DC biasing conditions. Additionally, with pulsing of 1 ?s gate voltage, hetJ pTFET exhibited enhanced drive current of 85 ?A/?m at V{sub DS}?=??0.5?V, which is the highest reported in the category of III-V pTFET. Detailed device characterization was performed through analysis of the capacitance-voltage characteristics, pulsed current-voltage characteristics, and x-ray diffraction studies.
Rajamohanan, Bijesh, E-mail: email@example.com; Mohata, Dheeraj; Hollander, Matthew; Datta, Suman [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zhu, Yan; Hudait, Mantu [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Jiang, Zhengping; Klimeck, Gerhard [Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47906 (United States)
Scanning tunneling microscopy/spectroscopy of picene thin films formed on Ag(111)
Using ultrahigh-vacuum low-temperature scanning tunneling microscopy and spectroscopy combined with first principles density functional theory calculations, we have investigated structural and electronic properties of pristine and potassium (K)-deposited picene thin films formed in situ on a Ag(111) substrate. At low coverages, the molecules are uniformly distributed with the long axis aligned along the [112{sup �}] direction of the substrate. At higher coverages, ordered structures composed of monolayer molecules are observed, one of which is a monolayer with tilted and flat-lying molecules resembling a (11{sup �}0) plane of the bulk crystalline picene. Between the molecules and the substrate, the van der Waals interaction is dominant with negligible hybridization between their electronic states; a conclusion that contrasts with the chemisorption exhibited by pentacene molecules on the same substrate. We also observed a monolayer picene thin film in which all molecules were standing to form an intermolecular ? stacking. Two-dimensional delocalized electronic states are found on the K-deposited ? stacking structure.
Yoshida, Yasuo, E-mail: firstname.lastname@example.com; Yokosuka, Takuya; Hasegawa, Yukio, E-mail: firstname.lastname@example.com [The Institute of Solid State Physics, The University of Tokyo, Kashiwa 277-8581 (Japan); Yang, Hung-Hsiang [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Huang, Hsu-Sheng; Guan, Shu-You; Su, Wei-Bin; Chang, Chia-Seng [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Yanagisawa, Susumu [Department of Physics and Earth Science Department, University of the Ryukyus, 1 Nishihara, Okinawa 903-0213 (Japan); Lin, Minn-Tsong [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Hoffmann, Germar [The Institute of Solid State Physics, The University of Tokyo, Kashiwa 277-8581 (Japan); Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
Influence of hydrogen patterning gas on electric and magnetic properties of perpendicular magnetic tunnel junctions
To identify the degradation mechanism in magnetic tunnel junctions (MTJs) using hydrogen, the properties of the MTJs were measured by applying an additional hydrogen etch process and a hydrogen plasma process to the patterned MTJs. In these studies, an additional 50?s hydrogen etch process caused the magnetoresistance (MR) to decrease from 103% to 14.7% and the resistance (R) to increase from 6.5?k? to 39?k?. Moreover, an additional 500?s hydrogen plasma process decreased the MR from 103% to 74% and increased R from 6.5?k? to 13.9?k?. These results show that MTJs can be damaged by the hydrogen plasma process as well as by the hydrogen etch process, as the atomic bonds in MgO may break and react with the exposed hydrogen gas. Compounds such as MgO hydrate very easily. We also calculated the damaged layer width (DLW) of the patterned MTJs after the hydrogen etching and plasma processes, to evaluate the downscaling limitations of spin-transfer-torque magnetic random-access memory (STT-MRAM) devices. With these calculations, the maximum DLWs at each side of the MTJ, generated by the etching and plasma processes, were 23.8?nm and 12.8?nm, respectively. This result validates that the hydrogen-based MTJ patterning processes cannot be used exclusively in STT-MRAMs beyond 20?nm.
Jeong, J. H., E-mail: email@example.com [Graduate School of Engineering, Tohoku University, Sendai (Japan); Semiconductor R and D Center, Samsung Electronics Co., Ltd., Hwasung (Korea, Republic of); Endoh, T. [Graduate School of Engineering, Tohoku University, Sendai (Japan); Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai (Japan); Kim, Y.; Kim, W. K.; Park, S. O. [Semiconductor R and D Center, Samsung Electronics Co., Ltd., Hwasung (Korea, Republic of)
Mechanism design with approximate types
In mechanism design, we replace the strong assumption that each player knows his own payoff type exactly with the more realistic assumption that he knows it only approximately: each player i only knows that his true type ...
Zhu, Zeyuan Allen
Types of Farming in Texas.
.......... .......-.----------------------. 8 Labor -..-.....-----...------------------------------------------------. 9 Land Tenure .--.----....---....--------------------------------- 9 Number and Size of Farms ....----...----.-._--------- 10 Capital... -------------...-------.---------------------------- 21 Hogs -......-....--------------------------------------------------- 22 Poultry .-.---.-.....--.-..------.---------------------------------- 22 Horses and Mules ---..-....---..--..------------------------ 23 Types of Farming and Type-of-farming...
Bonnen, C. A.
Tornado type wind turbines
A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.
Hsu, Cheng-Ting (Ames, IA)
On the asymptotic homotopy type of inductive limit Type ...
In this note we exhibit large classes of (projeetionless) stable, nuclear C*- algebras whose asymptotic homotopy type is determined by K-theoretical data.
Resonant tunneling with high peak to valley current ratio in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers at room temperature
We have investigated carrier transport in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers by room temperature current-voltage measurements. Resonant tunneling signatures accompanied by current peaks are observed. Carrier transport in the multi-layers were analyzed by plots of ln(I/V{sup 2}) as a function of 1/V and ln(I) as a function of V{sup 1/2}. Results suggest that besides films quality, nc-Si and barrier sub-layer thicknesses are important parameters that restrict carrier transport. When thicknesses are both small, direct tunneling dominates carrier transport, resonant tunneling occurs only at certain voltages and multi-resonant tunneling related current peaks can be observed but with peak to valley current ratio (PVCR) values smaller than 1.5. When barrier thickness is increased, trap-related and even high field related tunneling is excited, causing that multi-current peaks cannot be observed clearly, only one current peak with higher PVCR value of 7.7 can be observed. While if the thickness of nc-Si is large enough, quantum confinement is not so strong, a broad current peak with PVCR value as high as 60 can be measured, which may be due to small energy difference between the splitting energy levels in the quantum dots of nc-Si. Size distribution in a wide range may cause un-controllability of the peak voltages.
Chen, D. Y., E-mail: email@example.com [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China); Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Sun, Y.; He, Y. J. [Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Xu, L.; Xu, J. [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China)
A continuum model with a percolation threshold and tunneling-assisted interfacial conductivity for carbon nanotube-based nanocomposites
A continuum model that possesses several desirable features of the electrical conduction process in carbon-nanotube (CNT) based nanocomposites is developed. Three basic elements are included: (i) percolation threshold, (ii) interface effects, and (iii) tunneling-assisted interfacial conductivity. We approach the first one through the selection of an effective medium theory. We approach the second one by the introduction of a diminishing layer of interface with an interfacial conductivity to build a 'thinly coated' CNT. The third one is introduced through the observation that interface conductivity can be enhanced by electron tunneling which in turn can be facilitated with the formation of CNT networks. We treat this last issue in a continuum fashion by taking the network formation as a statistical process that can be represented by Cauchy's probability density function. The outcome is a simple and yet widely useful model that can simultaneously capture all these fundamental characteristics. It is demonstrated that, without considering the interface effect, the predicted conductivity would be too high, and that, without accounting for the additional contribution from the tunneling-assisted interfacial conductivity, the predicted conductivity beyond the percolation threshold would be too low. It is with the consideration of all three elements that the theory can fully account for the experimentally measured data. We further use the developed model to demonstrate that, despite the anisotropy of the intrinsic CNT conductivity, it is its axial component along the CNT direction that dominates the overall conductivity. This theory is also proved that, even with a totally insulating matrix, it is still capable of delivering non-zero conductivity beyond the percolation threshold.
Wang, Yang; Weng, George J., E-mail: firstname.lastname@example.com [Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, New Jersey 08903 (United States); Meguid, Shaker A. [Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada); Hamouda, Abdel Magid [Department of Mechanical and Industrial Engineering, Qatar University, Doha (Qatar)
Theory of two-dimensional macroscopic quantum tunneling in a Josephson junction coupled with an LC circuit
We investigate classical thermal activation (TA) and macroscopic quantum tunneling (MQT) for a Josephson junction coupled with an LC circuit theoretically. The TA and MQT escape rate are calculated analytically by taking into account the two-dimensional nature of the classical and quantum phase dynamics. We find that the MQT escape rate is largely suppressed by the coupling to the LC circuit. On the other hand, this coupling gives rise to slight reduction of the TA escape rate. These results are relevant for the interpretation of a recent experiment on the MQT and TA phenomena in grain boundary YBCO Josephson junctions.
Shiro Kawabata; Takeo Kato; Thilo Bauch
Direct experimental evidence for the reversal of carrier type upon hydrogen intercalation in epitaxial graphene/SiC(0001)
Raman spectroscopy and scanning tunneling microscopy/spectroscopy measurements are performed to determine the atomic structure and electronic properties of H-intercalated graphene/SiC(0001) obtained by annealing the as-grown epitaxial graphene in hydrogen atmosphere. While the as-grown graphene is found to be n-type with the Dirac point (E{sub D}) at 450 and 350?meV below Fermi level for the 1st and 2nd layer, the H-intercalated graphene is p-type with E{sub D} at 320 and 200?meV above. In addition, ripples are observed in the now quasi-free standing graphene decoupled from the SiC substrate. This causes fluctuations in the Dirac point that directly follow the undulations of the ripples, resulting in electron and hole puddles in the H-intercalated graphene/SiC(0001)
Rajput, S., E-mail: email@example.com; Li, Y. Y.; Li, L. [Department of Physics, University of Wisconsin, Milwaukee, Wisconsin 53211 (United States)
Soft Typing PHP Patrick Camphuijsen
Soft Typing PHP Patrick Camphuijsen Jurriaan Hage Stefan Holdermans Technical Report UU-CS-2009.O. Box 80.089 3508 TB Utrecht The Netherlands #12;Soft Typing PHP with PHP-validator Patrick email@example.com Abstract PHP is a popular language for building websites, but also notori- ously lax in that almost every
Utrecht, Universiteit
Cofinal types of directed orders
, ) directed partial orders #12;Cofinal types (P, ), (Q, ) directed partial orders Tukey reducibility: (P orders Tukey reducibility: (P, ) T (Q, ) if f : P Q X P unbounded = f [X] Q unbounded g : Q P Y Q cofinal = g[Y ] P cofinal #12;Cofinal types (P, ), (Q, ) directed partial orders Tukey reducibility: (P
Mátrai, Tamás
Tunneling magnetoresistance tuned by a vertical electric field in an AA-stacked graphene bilayer with double magnetic barriers
We investigate the effect of a vertical electric field on the electron tunneling and magnetoresistance in an AA-stacked graphene bilayer modulated by the double magnetic barriers with parallel or antiparallel configuration. The results show that the electronic transmission properties in the system are sensitive to the magnetic-barrier configuration and the bias voltage between the graphene layers. In particular, it is found that for the antiparallel configuration, within the low energy region, the blocking effect is more obvious compared with the case for the parallel configuration, and even there may exist a transmission spectrum gap which can be arbitrarily tuned by the field-induced interlayer bias voltage. We also demonstrate that the significant discrepancy between the conductance for both parallel and antiparallel configurations would result in a giant tunneling magnetoresistance ratio, and further the maximal magnetoresistance ratio can be strongly modified by the interlayer bias voltage. This leads to the possible realization of high-quality magnetic sensors controlled by a vertical electric field in the AA-stacked graphene bilayer.
Wang, Dali, E-mail: email@example.com [Department of Physics and Center for Nano Science and Technology, Anhui Normal University, Wuhu 241000 (China); National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Jin, Guojun, E-mail: firstname.lastname@example.com [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)
High-field electroluminescence in semiconductor tunnel junctions with a Mn-doped GaAs layer
We investigated high-field electroluminescence (EL) in semiconductor tunnel junctions with a Mn-doped GaAs layer (here, referred to as GaAs:Mn). Besides the band-gap emission of GaAs, the EL spectra show visible light emissions with two peaks at 1.94?eV and 2.19?eV, which are caused by d-d transitions of the Mn atoms excited by hot electrons. The threshold voltages for band-gap and visible light EL in the tunnel junctions with a GaAs:Mn electrode are 1.3?V higher than those of GaAs:Mn excited by hot holes in reserve biased p{sup +}-n junctions, which is consistent with the hot carrier transport in the band profiles of these structures. Our EL results at room temperature show that the electron temperature in GaAs:Mn can be as high as ?700?K for a low input electrical power density of 0.4?W/cm{sup 2}, while the lattice temperature of the GaAs:Mn layer can be kept at 340?K.
Hai, Pham Nam [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-0033 (Japan); Yatsui, Takashi; Ohtsu, Motoichi; Tanaka, Masaaki [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Nanophotonics Research Center, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)
LER-LHC injector workshop summary and super-ferric fast cycling injector in the SPS tunnel
A Workshop on Low Energy Ring (LER) in the LHC tunnel as main injector was convened at CERN on October 11-12, 2006. We present the outline of the LER based on the presentations, and respond to the raised questions and discussions including the post-workshop studies. We also outline the possibility of using the LER accelerator technologies for the fast cycling injector accelerator in the SPS tunnel (SF-SPS). A primary goal for the LER (Low Energy Ring) injector accelerator is to inject 1.5 TeV proton beams into the LHC, instead of the current injection scheme with 0.45 TeV beams from the SPS. At this new energy, the field harmonics [1] of the LHC magnets are sufficiently satisfactory to prevent the luminosity losses expected to appear when applying the transfer of the 0.45 TeV SPS beams. In addition, a feasibility study of batch slip stacking in the LER has been undertaken with a goal of increasing in this way the LHC luminosity by up to a factor of 4. A combined luminosity increase may, therefore, be in the range of an order of magnitude. In the long term, the LER injector accelerator would greatly facilitate the implementation of a machine, which doubles the LHC energy (DLHC).
Ambrosio, Giorgio; Hays, Steven; Huang, Yuenian; Johnstone, John; Kashikhin, Vadim; MacLachlan, James; Mokhov, Nikolai; Piekarz, Henryk; Sen, Tanaji; Shiltsev, Vladimir; /Fermilab; de Rijk, Gijsbert; /CERN
High-frequency response and the possibilities of frequency-tunable narrow-band terahertz amplification in resonant tunneling nanostructures
The characteristics of the high-frequency response of single- and double-well resonant tunneling structures in a dc electric field are investigated on the basis of the numerical solution of a time-dependent Schroedinger equation with open boundary conditions. The frequency dependence of the real part of high frequency conductivity (high-frequency response) in In{sub 0.53}Ga{sub 0.47}As/AlAs/InP structures is analyzed in detail for various values of the dc voltage V{sub dc} in the negative differential resistance (NDR) region. It is shown that double-well three-barrier structures are promising for the design of terahertz-band oscillators. The presence of two resonant states with close energies in such structures leads to a resonant (in frequency) response whose frequency is determined by the energy difference between these levels and can be controlled by varying the parameters of the structure. It is shown that, in principle, such structures admit narrow-band amplification, tuning of the amplification frequency, and a fine control of the amplification (oscillation) frequency in a wide range of terahertz frequencies by varying a dc electric voltage applied to the structure. Starting from a certain width of the central intermediate barrier in double-well structures, one can observe a collapse of resonances, where the structure behaves like a single-well system. This phenomenon imposes a lower limit on the oscillation frequency in three-barrier resonant tunneling structures.
Kapaev, V. V., E-mail: firstname.lastname@example.com; Kopaev, Yu. V.; Savinov, S. A.; Murzin, V. N. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)] [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)
New approaches for modeling type Ia supernovae
runaway in Type Ia supernovae: How to run away? oIgnition in Type Ia Supernovae. II. A Three- dimensionalnumber modeling of type Ia supernovae. I. hydrodynamics.
Zingale, Michael; Almgren, Ann S.; Bell, John B.; Day, Marcus S.; Rendleman, Charles A.; Woosley, Stan
Regular Type III and Type N Approximate Solutions
New type III and type N approximate solutions which are regular in the linear approximation are shown to exist. For that, we use complex transformations on self-dual Robinson-Trautman metrics rather then the classical approach. The regularity criterion is the boundedness and vanishing at infinity of a scalar obtained by saturating the Bel-Robinson tensor of the first approximation by a time-like vector which is constant with respect to the zeroth approximation.
Philip Downes; Paul MacAllevey; Bogdan Nita; Ivor Robinson
P-type gallium nitride
Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5{times}10{sup 11} /cm{sup 3} and hole mobilities of about 500 cm{sup 2} /V-sec, measured at 250 K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al. 9 figs.
Rubin, M.; Newman, N.; Fu, T.; Ross, J.; Chan, J.
Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5.times.10.sup.11 /cm.sup.3 and hole mobilities of about 500 cm.sup.2 /V-sec, measured at 250.degree. K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al.
Rubin, Michael (Berkeley, CA); Newman, Nathan (Montara, CA); Fu, Tracy (Berkeley, CA); Ross, Jennifer (Pleasanton, CA); Chan, James (Berkeley, CA)
Imaging an ionic liquid adlayer by scanning tunneling microscopy at the solid|vacuum interface
of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm, Germany 2 Institute of Particle Technology, Clausthal University of Technology, D-38678 Clausthal- Zellerfeld, Gemany Abstract The first imaging(pentafluoroethyl)trifluorophosphate ([Py1,4]FAP) was evaporated onto a clean Au(111) surface by a Knudsen-type evaporator and the surface
Pfeifer, Holger
Vibrations, Tunneling, and Transition Dipole Moments in the Water Dimer Michael J. Smit, Gerrit C. Groenenboom, Paul E. S. Wormer, and Ad van der Avoird*
shows that only the states of E( symmetry of the water dimer have a permanent dipole moment. A model dipole moment of the E( states. 1. Introduction Liquid water is the most important biological substanceVibrations, Tunneling, and Transition Dipole Moments in the Water Dimer Michael J. Smit, Gerrit C
Bound states of tunneling electrons in molecular chains M. A. Kozhushner,1 V. S. Posvyanskii,1 and I. I. Oleynik2
-state energy spectrum of the negative molecular ion, i.e., the system consisting of one electron plus a neutral scattering theory MST . The subbarrier scattering operators, the fundamental building blocks of MST that the energy spectrum of the bound states of the tunneling electron in a linear chain of three
Oleynik, Ivan
1D to 1D Tunneling in a Dual Electron Waveguide Device C. C. Euaster, J. A. del Alamo,M. R. Mellocht, M. J. Rooks*
1D to 1D Tunneling in a Dual Electron Waveguide Device C. C. Euaster, J. A. del Alamo,M. R on a dual electron waveguide device. In this device, two closely spaced 1D channels are electrostati- cally have fabricated a variety of dual electron waveguide devices with different lengths L and widths W
del Alamo, Jesús A.
Atomic-Scale Investigation of Epitaxial Graphene Grown on 6H-SiC(0001) Using Scanning Tunneling Microscopy and Spectroscopy
Atomic-Scale Investigation of Epitaxial Graphene Grown on 6H-SiC(0001) Using Scanning Tunneling ReceiVed: June 26, 2010 Graphene was epitaxially grown on a 6H-SiC(0001) substrate by thermal the evolution of the graphene growth as a function of the temperature. We found that the evaporation of Si
PHYS 390 Lecture 18 -Reactions I -Tunneling 18 -1 2001 by David Boal, Simon Fraser University. All rights reserved; further resale or copying is strictly prohibited.
. 4.1 and 4.5 Coulomb barrier to nuclear reactions The elementary particle reactions that occurred K. Such low temperatures affect reactions in two ways: · the reactions may occur through the phenomenon of quantum mechanical tunneling · the low energy end of a thermal distribution of particles may
Boal, David
Effects of Be acceptors on the spin polarization of carriers in p-i-n resonant tunneling diodes
In this paper, we have investigated the effect of Be acceptors on the electroluminescence and the spin polarization in GaAs/AlAs p-i-n resonant tunneling diodes. The quantum well emission comprise two main lines separated by ?20?meV attributed to excitonic and Be-related transitions, which intensities show remarkably abrupt variations at critical voltages, particularly at the electron resonant peak where it shows a high-frequency bistability. The circular-polarization degree of the quantum-well electroluminescence also shows strong and abrupt variations at the critical bias voltages and it attains relatively large values (of ??75% at 15?T). These effects may be explored to design novel devices for spintronic applications such as a high-frequency spin-oscillators.
Awan, I. T.; Galv�o Gobato, Y. [Departamento de F�sica, Universidade Federal de S�o Carlos (UFSCAR) 13560-905, S�o Carlos, SP (Brazil); Galeti, H. V. A. [Departamento de Engenharia El�trica, Universidade Federal de S�o Carlos 13560-905, S�o Carlos, SP (Brazil); Brasil, M. J. S. P. [Institute of Physics Gleb Wataghin, UNICAMP, Campinas (Brazil); Taylor, D.; Henini, M. [School of Physics and Astronomy, Nottingham Nanotechnology and Nanoscience Centre, University of Nottingham, Nottingham NG7 2RD (United Kingdom)
Ultra-High Pressure Driver and Nozzle Survivability in the RDHWT/MARIAH II Hypersonic Wind Tunnel
An ultra-high pressure device provides a high enthalpy (> 2500 kJ/kg), low entropy (< 5 kJ/kg-K) air source for the RDHWT/MARIAH II Program Medium Scale Hypersonic Wind Tunnel. The design uses stagnation conditions of 2300 MPa (330,000 Psi) and 750 K (900 F) in a radial configuration of intensifiers around an axial manifold to deliver pure air at 100 kg/s mass flow rates for run times suitable for aerodynamic, combustion, and test and evaluation applications. Helium injection upstream of the nozzle throat reduces the throat wall recovery temperature to about 1200 K and reduces the oxygen concentration at the nozzle wall.
Costantino, M.; Brown, G.; Raman, K.; Miles, R.; Felderman, J.
Conceptual Design of a 50--100 MW Electron Beam Accelerator System for the National Hypersonic Wind Tunnel Program
The National Hypersonic Wind Tunnel program requires an unprecedented electron beam source capable of 1--2 MeV at a beam power level of 50--100 MW. Direct-current electron accelerator technology can readily generate high average power beams to approximately 5 MeV at output efficiencies greater than 90%. However, due to the nature of research and industrial applications, there has never been a requirement for a single module with an output power exceeding approximately 500 kW. Although a 50--100 MW module is a two-order extrapolation from demonstrated power levels, the scaling of accelerator components appears reasonable. This paper presents an evaluation of component and system issues involved in the design of a 50--100 MW electron beam accelerator system with precision beam transport into a high pressure flowing air environment.
DNA and RNA sequencing by nanoscale reading through programmable electrophoresis and nanoelectrode-gated tunneling and dielectric detection
An apparatus and method for performing nucleic acid (DNA and/or RNA) sequencing on a single molecule. The genetic sequence information is obtained by probing through a DNA or RNA molecule base by base at nanometer scale as though looking through a strip of movie film. This DNA sequencing nanotechnology has the theoretical capability of performing DNA sequencing at a maximal rate of about 1,000,000 bases per second. This enhanced performance is made possible by a series of innovations including: novel applications of a fine-tuned nanometer gap for passage of a single DNA or RNA molecule; thin layer microfluidics for sample loading and delivery; and programmable electric fields for precise control of DNA or RNA movement. Detection methods include nanoelectrode-gated tunneling current measurements, dielectric molecular characterization, and atomic force microscopy/electrostatic force microscopy (AFM/EFM) probing for nanoscale reading of the nucleic acid sequences.
Lee, James W.; Thundat, Thomas G.
Optimization in the Parikh-Wilczek tunneling model of Hawking radiation for Kerr-Newman Black Holes
In this short report, we investigate the mutual information hidden in the Parikh-Wilczek tunneling model of Hawking radiation for Kerr-Newman black holes. By assuming the radiation as an optimization process, we discuss its effect on time evolution of rotating (charged and uncharged) black holes. For uncharged rotating black holes evaporating under the maximum mutual information optimization, their scale invariant rotation parameter $a_*=a/M$ is almost constant at the early stage but rapidly increase at the very last stage of the evaluation process. The value of rotation parameter at the final state of evaporation depends on the initial condition of the black hole. We also found that the presence of electric charge can cause the black holes lose their angular momentum more rapidly than they lose mass. The charged-rotating black holes asymptotically approach a state which is described by $a_*= 0$ and $Q/M = 1$.
Auttakit Chatrabhuti; Khem Upathambhakul
Double injection, resonant-tunneling recombination, and current-voltage characteristics in double-graphene-layer structures
We evaluate the effect of the recombination associated with interlayer transitions in ungated and gated double-graphene-layer (GL) structures on the injection of electrons and holes. Using the proposed model, we derive analytical expressions for the spatial distributions of the electron and hole Fermi energies and the energy gap between the Dirac points in GLs as well as their dependences on the bias and gate voltages. The current-voltage characteristics are calculated as well. The model is based on hydrodynamic equations for the electron and hole transports in GLs under the self-consistent electric field. It is shown that in undoped double-GL structures with weak scattering of electrons and holes on disorder, the Fermi energies and the energy gap are virtually constant across the main portions of GLs, although their values strongly depend on the voltages and recombination parameters. In contrast, the electron and hole scattering on disorder lead to substantial nonuniformities. The resonant inter-GL tunneling enables N-shaped current-voltage characteristics provided that GLs are sufficiently short. The width of the current maxima is much larger than the broadening of the tunneling resonance. In the double-GL structures with relatively long GLs, the N-shaped characteristics transform into the Z-shaped characteristics. The obtained results are in line with the experimental observations [Britnell et al., Nat. Commun. 4, 1794�1799 (2013)] and might be useful for design and optimization of different devices based on double-GL structures, including field-effect transistors and terahertz lasers.
Ryzhii, M. [Department of Computer Science and Engineering, University of Aizu, Aizu-Wakamatsu 965-8580 (Japan); Ryzhii, V. [Research Institute for Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Institute of Ultra High Frequency Semiconductor Electronics, Russian Academy of Sciences, Moscow 111005 (Russian Federation); Otsuji, T. [Research Institute for Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Maltsev, P. P. [Institute of Ultra High Frequency Semiconductor Electronics, Russian Academy of Sciences, Moscow 111005 (Russian Federation); Leiman, V. G. [Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700 (Russian Federation); Ryabova, N. [Department of Computer Science and Engineering, University of Aizu, Aizu-Wakamatsu 965-8580 (Japan); Center for Photonics and Infrared Engineering, Bauman Moscow State Technical University, Moscow 105005 (Russian Federation); Mitin, V. [Department of Electrical Engineering, University at Buffalo, Buffalo, New York 1460-1920 (United States)
Requirements for Foreign National Payments Type of Payment Visa Type
8233 36% 36% Royalty* NA NA NA NA Yes NA* No Yes W8BEN Varies 1. The visa types listed are the most related to the field of study on the I-20. 10. For Royalty payments the visa doc is not needed when
Wolpert, Robert L
Dark fleshed varieties (Bing type) in regular type, light fleshed varieties (Rainier type) in italics Sweet Cherries
Dark fleshed varieties (Bing type) in regular type, light fleshed varieties (Rainier type and Royalton. For more information about these and other varieties, visit our web site at www
Country Scotland Type Single malt
Country Scotland Type Single malt Distillery Aberfeldy Region Highlands Age 12 years ABV 40% Cask, the perfume characteristics become more spicy, with a bitter hint of Seville oranges in a decidedly dry finish. Drying citrus/oak with a gentle spiciness, held in a warm embrace of cigar smoke, and a little vanilla
Izzard, Rob
Country Scotland Type Single malt Distillery Jura Region Island Name Prophecy ABV 46 Cask French airport Notes Limited annual release: 10,000 bottles only. Nose Some peat, aniseed, oily, dry, pungent, dried hay, and anise round things out. Palate Smoky and dry, a muscular, powerful Jura with notes
Automatic Utterance Type Detection Using Suprasegmental Features�
that different types of utterances have different suprasegmental characteristics. The categorisation of these utterance types is based on the theory of conversation games and consists of 12 move types (e.g. reply to a question, wh-question, acknowledgement...
Wright, Helen
Department of Defense/Department of Energy joint demilitarization technology demonstration program executive summary of Phase II demonstrations: The low-pressure rocket motor burns in X-Tunnel
Three low-pressure rocket motor burn tests were executed in May--June 1997 time frame at the X-tunnel complex located on the Department of Energy's Nevada Test Site.
B. W. Bellow; A. E. Moeller; D. Steele; S. M. Williams; R. L. Heinle; C. O. Pruneda; C. A. Velsko; B. E. Watkins; C. J. Hewitt; H. Fry; J. A. Sanchez; J. R. Stephens; J. R. Carson; W. C. Gray; W. C. Thomas; T. J. Tope; S. W. Allendorf; L. R. Carrillo; H. H. Hirano; H. A. Johnsen; J. Lipkin; D. K. Ottesen; R. L. Peabody; C. R. Shaddix; J. C. Swearengen; R. F. Boehm; A. Smiecinski; K. J. Stetzenback
Superconductivity: coherent "tunnelling" by a dielectric array of charge-carriers
Superconduction manifests when a steady-state current flows through a material without an electric field being present. It is argued here that the absence of scattering of the charge-carriers, although absolutely necessary, is not sufficient to explain why an electric field is zero when a current flows between two contacts to a superconducting material. It is concluded that an electric field, and thus a resistance, must manifest unless (i) the charge-carriers form part of an array of dielectric charge centres, and (ii) the charge-carriers can increase their velocities without increasing their kinetic energies. A model is propoased which allows these requirements to manifest. The model is fitted to selected experimental results which have been published for low temperature metals, YBCO, and highly-doped p-type diamond. In each case a satisfactory description of the experimental results is demonstrated.
Johan F. Prins
Proposal to negotiate an amendment to an existing contract for the supply and installation of pipelines for the LHC accelerator tunnel
This document concerns the proposal to negotiate an amendment to an existing contract for the supply and installation of pipelines for the LHC accelerator tunnel. For the reasons explained in this document, the Finance Committee is invited to approve an amendment to the existing contract for the supply and installation of pipelines for the LHC accelerator tunnel with the firm RENCO (IT) for an amount exceeding the previously approved amount of 21 995 304 Swiss francs by up to 5 000 000 Swiss francs, not subject to revision, bringing the total contract amount to a maximum amount of 26 995 304 Swiss francs, not subject to revision. The firm has declared the following origin of the equipment covered by this adjudication proposal: IT - 100%.
Heat transfer coefficient saturation in superconducting Nb tunnel junctions contacted to a NbTiN circuit and an Au energy relaxation layer
In this paper we present the experimental realization of a Nb tunnel junction connected to a high-gap superconducting NbTiN embedding circuit. We investigate relaxation of nonequilibrium quasiparticles in a small volume Au layer between the Nb tunnel junction and the NbTiN circuit. We find a saturation in the effective heat-transfer coefficient consistent with a simple theoretical model. This saturation is determined by the thickness of the Au layer. Our findings are important for the design of the ideal Au energy relaxation layer for practical SIS heterodyne mixers and we suggest two geometries, one, using a circular Au layer and, two, using a half-circular Au layer. Our work is concluded with an outlook of our future experiments.
Selig, Stefan; Jacobs, Karl; Schultz, Michael; Honingh, Netty
Role of Coulomb blockade and spin-flip scattering in tunneling magnetoresistance of FeCo-Si-O nanogranular films
In this work, we report the effect of FeCo atomic fraction (0.33 < x < 0.54) and temperature on the electrical, magnetic, and tunneling magnetoresistance (TMR) properties of FeCo-Si-O granular films prepared by atom beam sputtering technique. Glancing angle x-ray diffraction and TEM studies reveal that films are amorphous in nature. The dipole-dipole interactions (particle-matrix mixing) is evident from zero-field cooled and field-cooled magnetic susceptibility measurements and the presence of oxides (mainly Fe-related) is observed by x-ray photoelectron spectroscopy analysis. The presence of Fe-oxides is responsible for the observed reduction of saturation magnetization and rapid increase in coercivity below 50 K. TMR has been observed in a wide temperature range, and a maximum TMR of -4.25% at 300 K is observed for x = 0.39 at a maximum applied field of 60 kOe. The fast decay of maximum TMR at high temperatures and lower TMR values at 300 K when compared to P{sub FeCo}{sup 2}/(1+P{sub FeCo}{sup 2}), where P{sub FeCo} is the spin polarization of FeCo are in accordance with a theoretical model that includes spin-flip scattering processes. The temperature dependent study of TMR effect reveals a remarkably enhanced TMR at low temperatures. The TMR value varies from -2.1% at 300 K to -14.5% at 5 K for x = 0.54 and a large MR value of -18.5% at 5 K for x = 0.39 is explained on the basis of theoretical models involving Coulomb blockade effects. Qualitatively particle-matrix mixing and the presence of Fe-oxides seems to be the source of spin-flip scattering, responsible for fast decay of TMR at high temperatures. A combination of higher order tunneling (in Coulomb blockade regime) and spin-flip scattering (high temperature regime) explains the temperature dependent TMR of these films.
Kumar, Hardeep; Ghosh, Santanu [Nanostech Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Buerger, Danilo; Zhou, Shengqiang; Groetzschel, Rainer; Schmidt, Heidemarie [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Li, Lin [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100 871 (China); Kabiraj, Debdulal; Avasthi, Devesh Kumar [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)
A Vision-based Method for On-Road Truck Height Measurement in Proactive Prevention of 2 Collision with Overpasses and Tunnels
and Tunnels 2 Fei Dai a, Man-Woo Park b,*, Matthew Sandidge c, and Ioannis Brilakis d 3 a Department of Civil and Environmental Engineering, West Virginia University, 635 Engineering 4 Sciences Building, 395 Evansdale Drive, Morgantown, WV 26506, USA, Email... and luggage handling in airports. 473 474 6. Acknowledgement 475 This material is based upon work supported by West Virginia University, Myongji University, and 476 University of Cambridge. Any opinions, findings, and conclusions or recommendations...
Dai, Fei; Park, Man-Woo; Sandidge, Matthew; Brilakis, Ioannis
Terahertz vibration-rotation-tunneling spectroscopy of the water tetramer-d8: Combined analysis of vibrational bands at 4.1 and 2.0 THz
Terahertz vibration-rotation-tunneling spectroscopy of the water tetramer-d8: Combined analysis of vibrational bands at 4.1 and 2.0 THz Wei Lin,a Jia-Xiang Han,b Lynelle K. Takahashi, Heather A. Harker,c Frank in the global fit of the water trimer. The detailed understanding of the water tetramer evolving from this work
Magnetic properties of epitaxial Fe{sub 3}O{sub 4} films with various crystal orientations and tunnel magnetoresistance effect at room temperature
Fe{sub 3}O{sub 4} is a ferrimagnetic spinel ferrite that exhibits electric conductivity at room temperature (RT). Although the material has been predicted to be a half metal according to ab-initio calculations, magnetic tunnel junctions (MTJs) with Fe{sub 3}O{sub 4} electrodes have demonstrated a small tunnel magnetoresistance (TMR) effect. Not even the sign of the tunnel magnetoresistance ratio has been experimentally established. Here, we report on the magnetic properties of epitaxial Fe{sub 3}O{sub 4} films with various crystal orientations. The films exhibited apparent crystal orientation dependence on hysteresis curves. In particular, Fe{sub 3}O{sub 4}(110) films exhibited in-plane uniaxial magnetic anisotropy. With respect to the squareness of hysteresis, Fe{sub 3}O{sub 4} (111) demonstrated the largest squareness. Furthermore, we fabricated MTJs with Fe{sub 3}O{sub 4}(110) electrodes and obtained a TMR effect of ?12% at RT. The negative TMR ratio corresponded to the negative spin polarization of Fe{sub 3}O{sub 4} predicted from band calculations.
Nagahama, Taro, E-mail: firstname.lastname@example.com; Matsuda, Yuya; Tate, Kazuya; Kawai, Tomohiro; Takahashi, Nozomi; Hiratani, Shungo; Watanabe, Yusuke; Yanase, Takashi; Shimada, Toshihiro [Graduate School of Engineering, Hokkaido University, Kita13 Nishi8, Kitak-ku, Sapporo 060-8628 (Japan)
Photo-induced tunneling currents in MOS structures with various HfO{sub 2}/SiO{sub 2} stacking dielectrics
In this study, the current conduction mechanisms of structures with tandem high-k dielectric in illumination are discussed. Samples of Al/SiO{sub 2}/Si (S), Al/HfO{sub 2}/SiO{sub 2}/Si (H), and Al/3HfO{sub 2}/SiO{sub 2}/Si (3H) were examined. The significant observation of electron traps of sample H compares to sample S is found under the double bias capacitance-voltage (C-V) measurements in illumination. Moreover, the photo absorption sensitivity of sample H is higher than S due to the formation of HfO{sub 2} dielectric layer, which leads to larger numbers of carriers crowded through the sweep of V{sub G} before the domination of tunneling current. Additionally, the HfO{sub 2} dielectric layer would block the electrons passing through oxide from valance band, which would result in less electron-hole (e{sup ?}-h{sup +}) pairs recombination effect. Also, it was found that both of the samples S and H show perimeter dependency of positive bias currents due to strong fringing field effect in dark and illumination; while sample 3H shows area dependency of positive bias currents in strong illumination. The non-uniform tunneling current through thin dielectric and through HfO{sub 2} stacking layers are importance to MOS(p) tunneling photo diodes.
Pang, Chin-Sheng; Hwu, Jenn-Gwo, E-mail: email@example.com [Graduate Institute of Electronics Engineering/Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)] [Graduate Institute of Electronics Engineering/Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)
Investigation of TiO{sub x} barriers for their use in hybrid Josephson and tunneling junctions based on pnictide thin films
We tested oxidized titanium layers as barriers for hybrid Josephson junctions with high I{sub c}R{sub n}-products and for the preparation of junctions for tunneling spectroscopy. For that we firstly prepared junctions with conventional superconductor electrodes, such as lead and niobium, respectively. By tuning the barrier thickness, we were able to change the junction's behavior from a Josephson junction to tunnel-like behavior applicable for quasi-particle spectroscopy. Subsequently, we transferred the technology to junctions using Co-doped BaFe{sub 2}As{sub 2} thin films prepared by pulsed laser deposition as base electrode and evaporated Pb as counter electrode. For barriers with a thickness of 1.5?nm, we observe clear Josephson effects with I{sub c}R{sub n}?90??V at 4.2?K. These junctions behave SNS'-like (SNS: superconductor-normal conductor-superconductor) and are dominated by Andreev reflection transport mechanism. For junctions with barrier thickness of 2.0?nm and higher, no Josephson but SIS'- (SIS: superconductor-insulator-superconductor) or SINS'-like (SINS: superconductor-normal conductor-insulator-superconductor) behavior with a tunnel-like conductance spectrum was observed.
D�ring, S., E-mail: email@example.com; Monecke, M.; Schmidt, S.; Schmidl, F.; Tympel, V.; Seidel, P., E-mail: email@example.com [Institute of Solid State Physics, Friedrich-Schiller-Universit�t Jena, Helmholtzweg 5, 07743 Jena (Germany); Engelmann, J.; Kurth, F.; Iida, K.; Holzapfel, B. [Institute for Metallic Materials, IFW Dresden, Helmholtzstrasse 20, 01171 Dresden (Germany); Haindl, S. [Institute for Solid State Research, IFW Dresden, Helmholtzstrasse 20, 01171 Dresden (Germany); M�nch, I. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01171 Dresden (Germany)
Spatial Data Types: Conceptual Foundation for
Spatial Data Types: Conceptual Foundation for the Design and Implementation of Spatial Database email@example.com #12;Markus Schneider, Tutorial "Spatial Data Types" 2 Abstract Spatial are usually called spatial data types, such as point, line, and region but also include more complex types
Güting, Ralf Hartmut
XML Document XML Document Types and Validation
XML Document Types and Validation IIM-I340 Objectives XML Document Types and Validation IIM-I340 April, 2010 #12;XML Document Types and Validation IIM-I340 Objectives Learning Objectives Understand: The need for validation Two ways to specify validity: Document Type Definitions (DTDs) XML Schemas #12;XML
Weber, Gregory D.
hal00270574, Testing Data Types Implementations from
is data type abstraction, testing a concrete implementation raises the issue of the gap betweenhal00270574, version 1 6 Apr 2008 Testing Data Types Implementations from Algebraic email@example.com Abstract. Algebraic speci#12;cations of data types provide a natural basis for testing data types
Wheel-type magnetic refrigerator
The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load. 7 figs.
Barclay, J.A.
Algorthmique Types abstraits de donns
abstrait de données (TAD) est : 1. un ensemble de données organisé et 2. d'opérations sur ces données. Il appel aux données et aux opérations abstraites du TAD (cou supérieure), 2. suivi d'un choix de représentation du TAD en mémoire (couche inférieure). Types abstraits de donn´ees p.3/90 #12;Décomposition en
Brun, Chez Luc
Window Types | Department of Energy
Energy Savers [EERE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehiclesTankless or Demand-TypeWelcome toFarm Growth Through theofWindow
An Introduction to Type Theory Dan Christensen
: Type a : A B : Type inl(a) : A + B A : Type b : B inr(b) : A + B C : Type p : A + B , x : A cA : C , y : B cB : C case(p, cA, cB) : C C : Type a : A , x : A cA : C , y : B cB : C case(inl(a), c
Christensen, Dan
Corrective Action Decision Document/Closure Report for Corrective Action Unit 383: Area E-Tunnel Sites, Nevada Test Site
This Corrective Action Decision Document/Closure Report (CADD/CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 383, Area 12 E-Tunnel Sites, which is the joint responsibility of DTRA and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO). This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the DOE, and the U.S. Department of Defense. Corrective Action Unit 383 is comprised of three Corrective Action Sites (CASs) and two adjacent areas: � CAS 12-06-06, Muckpile � CAS 12-25-02, Oil Spill � CAS 12-28-02, Radioactive Material � Drainage below the Muckpile � Ponds 1, 2, and 3 The purpose of this CADD/CR is to provide justification and documentation to support the recommendation for closure with no further corrective action, by placing use restrictions at the three CASs and two adjacent areas of CAU 383.
Computational study of heterojunction graphene nanoribbon tunneling transistors with p-d orbital tight-binding method
The graphene nanoribbon (GNR) tunneling field effect transistor (TFET) has been a promising candidate for a future low power logic device due to its sub-60?mV/dec subthreshold characteristic and its superior gate control on the channel electrons due to its one-dimensional nature. Even though many theoretical studies have been carried out, it is not clear that GNR TFETs would outperform conventional silicon metal oxide semiconductor field effect transistors (MOSFETs). With rigorous atomistic simulations using the p/d orbital tight-binding model, this study focuses on the optimization of GNR TFETs by tuning the doping density and the size of GNRs. It is found that the optimized GNR TFET can operate at a half of the supply voltage of silicon nanowire MOSFETs in the ballistic limit. However, a study on the effects of edge roughness on the performance of the optimized GNR TFET structure reveals that experimentally feasible edge roughness can deteriorates the on-current performance if the off-current is normalized with the low power requirement specified in the international technology roadmap for semiconductors.
Kim, SungGeun, E-mail: firstname.lastname@example.com; Klimeck, Gerhard [Network for Computational Nanotechnology, Purdue University, West Lafayette, Indiana 47907 (United States); Luisier, Mathieu [Integrated Systems Laboratory, Gloriastrasse 35, ETH Z�rich, 8092 Z�rich (Switzerland); Boykin, Timothy B. [Department of Electrical and Computer Engineering, The University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)
Understanding resonant tunnel transport in non-identical and non-aligned clusters as applied to disordered carbon systems
We study the conductance spectra and the corresponding current-voltage characteristics of a set of three impurity clusters of different sizes arranged in the form of a scalene triangle and compare with the transport of their horizontal and vertical configurations. The tuning capability of resonant tunnelling features in a quantum dot device made of these non-aligned impurity clusters is demonstrated by re-distributing their diameters and inter-cluster distances in a systematic manner. By manipulating the inter-cluster coupling for a scalene triangular configuration, the transition of current-voltage curves from a step-like feature to a negative differential resistance can be produced. This process also yields conductance features for triangular configurations, which can be compared to the quantum dot structures perfectly aligned to the direction of the propagating wavevector. The strength of inter-cluster coupling or order parameter for these configurations is analysed from the relative variation of the width and the energy difference of the sharp and broad peaks observed in the density of states spectra. Based on the relative change of the inter-cluster coupling with the cluster configurations, a transport model applicable to structurally inhomogeneous systems is proposed in order to explain the experimentally observed variation of the energy band gap with the disorder parameters.
Bhattacharyya, Somnath, E-mail: email@example.com [Nano-Scale Transport Physics Laboratory, School of Physics, University of the Witwatersrand, Private Bag 3, WITS 2050 Johannesburg (South Africa); School of Physics and Astronomy, University of Leeds, E C Stoner Laboratory, Leeds LS2 9JT (United Kingdom); Churochkin, Dmitry [Nano-Scale Transport Physics Laboratory, School of Physics, University of the Witwatersrand, Private Bag 3, WITS 2050 Johannesburg (South Africa)
Hydrogen in Type Ic Supernovae?
By definition, a Type Ic supernova (SN Ic) does not have conspicuous lines of hydrogen or helium in its optical spectrum. SNe Ic usually are modelled in terms of the gravitational collapse of bare carbon-oxygen cores. We consider the possibility that the spectra of ordinary (SN 1994I-like) SNe Ic have been misinterpreted, and that SNe Ic eject hydrogen. An absorption feature usually attributed to a blend of Si II 6355 and C II 6580 may be produced by H-alpha. If SN 1994I-like SNe Ic eject hydrogen, the possibility that hypernova (SN 1998bw-like) SNe Ic, some of which are associated with gamma-ray bursts, also eject hydrogen should be considered. The implications of hydrogen for SN Ic progenitors and explosion models are briefly discussed.
David Branch; David J. Jeffery; Timothy R. Young; E. Baron
Ideal bandpasses for type Ia supernova cosmology
diversity of type Ia Supernovae, in preparation. Kim, A.error in measurements of supernovae depends on a periodicABSTRACT To use type Ia supernovae as standard candles for
Davis, Tamara M.; Schmidt, Brian P.; Kim, Alex G.
ich and J. Stein. On the thermonuclear runaway in Type IaSmall-Scale Stability of Thermonuclear Flames o in Type IaS. E. Woosley. The thermonuclear explosion of chandrasekhar
Archive Reference Buildings by Building Type: Warehouse
Here you will find past versions of the reference buildings for new construction commercial buildings, organized by building type and location. A summary of building types and climate zones is...
Archive Reference Buildings by Building Type: Supermarket
Corrective Action Decision Document/Closure Report for Corrective Action Unit 504: 16a-Tunnel Muckpile, Nevada Test Site
This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 504, 16a-Tunnel Muckpile. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. Corrective Action Unit 504 is comprised of four Corrective Action Sites (CASs): � 16-06-01, Muckpile � 16-23-01, Contaminated Burial Pit � 16-23-02, Contaminated Area � 16-99-01, Concrete Construction Waste Corrective Action Site 16-23-01 is not a burial pit; it is part of CAS 16-06-01. Therefore, there is not a separate data analysis and assessment for CAS 16-23-01; it is included as part of the assessment for CAS 16-06-01. In addition to these CASs, the channel between CAS 16-23-02 (Contaminated Area) and Mid Valley Road was investigated with walk-over radiological surveys and soil sampling using hand tools. The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 504. A CADD was originally submitted for CAU 504 and approved by the Nevada Division of Environmental Protection (NDEP). However, following an agreement between NDEP, DTRA, and the DOE, National Nuclear Security Administration Nevada Site Office to change to a risk-based approach for assessing the corrective action investigation (CAI) data, NDEP agreed that the CAU could be re-evaluated using the risk-based approach and a CADD/CR prepared to close the site.
Rates and progenitors of type Ia supernovae
Supernovae . . . . . . . . . . . . . . . . . . . .Supernovae Found 5.1 Introduction . . . . . . . . . . . .1.2 Non-Type Ia Supernovae . . . . . . . . . . . . . . . 1.3
Wood-Vasey, William Michael
Overload permit rules applicable to H-type and HS-type bridges
This document defines standards for issuing permits for overweight vehicles crossing standard H-type and HS-type Texas highway bridges. A general formula and a bridge specific formula have been developed for simple spans of both bridge types...
Litchfield, Stephen Charles
Fuzzy Typing for Document Management Alison HUETTNER
Fuzzy Typing for Document Management Alison HUETTNER Clairvoyance Corporation 5301 Fifth Avenue method of document analysis and management, based on a combination of techniques from NLP and fuzzy logic typing for document management. The fuzzy typing approach is general in scope and can be applied to many
Wu, Dekai
Aspectual Session Types Nicolas Tabareau Mario Sdholt
Aspectual Session Types Nicolas Tabareau Mario Südholt ASCOLA Team Mines Nantes & Inria & LINA locally in each peer. Well-typed processes behave accordingly to the global protocol specification to support modular extensions with aspectual session types, a static pointcut/advice mechanism at the session
Type Ia Supernova Carbon Footprints
We present convincing evidence of unburned carbon at photospheric velocities in new observations of 5 Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified by examining 346 spectra from 124 SNe obtained before +2.5 d relative to maximum. Detections are based on the presence of relatively strong C II 6580 absorption "notches" in multiple spectra of each SN, aided by automated fitting with the SYNAPPS code. Four of the 5 SNe in question are otherwise spectroscopically unremarkable, with ions and ejection velocities typical of SNe Ia, but spectra of the fifth exhibits high-velocity (v > 20,000 km/s) Si II and Ca II features. On the other hand, the light curve properties are preferentially grouped, strongly suggesting a connection between carbon-positivity and broad band light curve/color behavior: Three of the 5 have relatively narrow light curves but also blue colors, and a fourth may be a dust-reddened member of this family. Accounting for signal-to-noise and phase, we ...
Thomas, R C; Aragon, C; Antilogus, P; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Childress, M; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Hsiao, E Y; Kerschhaggl, M; Kowalski, M; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Rubin, D; Runge, K; Scalzo, R; Smadja, G; Tao, C; Weaver, B A; Wu, C; Brown, P J; Milne, P A
Full-dimensional characterization of photoelectron spectra of HOCO{sup ?} and DOCO{sup ?} and tunneling facilitated decay of HOCO prepared by anion photodetachment
The photodetachment of both the HOCO{sup ?} and DOCO{sup ?} anions is investigated using full-dimensional quantum wave packets on new ab initio based global potential energy surfaces for both the neutral and anionic species. The calculated electron affinities and neutral fundamental vibrational frequencies of both isotopomers are in good agreement with available experimental data. The measured photoelectron spectra are also accurately reproduced, further validating the accuracy of the potential energy surfaces. In addition, strong mode specificity is found in the lifetimes of the HOCO vibrational features and the tunneling facilitated predissociation rates to H + CO{sub 2} are rationalized using the recently proposed sudden vector projection model.
Wang, Jun [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065 (China) [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065 (China); School of Science, Sichuan University of Science and Engineering, Zigong, Sichuan 643000 (China); Li, Jun; Guo, Hua, E-mail: email@example.com, E-mail: email@example.com [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)] [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Ma, Jianyi, E-mail: firstname.lastname@example.com, E-mail: email@example.com [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065 (China) [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065 (China); Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)
Current-induced switching of magnetic tunnel junctions: Effects of field-like spin-transfer torque, pinned-layer magnetization orientation, and temperature
We study current-induced switching in magnetic tunnel junctions in the presence of a field-like spin-transfer torque and titled pinned-layer magnetization in the high current limit at finite temperature. We consider both the Slonczewski and field-like torques with coefficients a{sub J} and b{sub J}, respectively. At finite temperatures, ?=b{sub J}/a{sub J}=�1 leads to a smaller mean switching time compared that with ?=0. The reduction of switching time in the presence of the field-like term is due to the alignment effect (for ?>0) and the initial torque effect.
Tiwari, R. K.; Jhon, M. H.; Ng, N.; Gan, C. K., E-mail: firstname.lastname@example.com [Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, 16-16 Connexis, Singapore 138632 (Singapore); Srolovitz, D. J. [Department of Materials Science, Engineering, Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)
The "Tunneling Two-Level Systems" Model of the Low-Temperature Properties of Glasses: Are "Smoking-Gun" Tests Possible?
Following a brief review of the "two-level (tunneling) systems" model of the low-temperature properties of amorphous solids ("glasses"), we ask whether it is in fact the unique explanation of these properties as is usually assumed, concluding that this is not necessarily the case. We point out that (a) one specific form of the model is already experimentally refuted, and (b) that a definitive test of the model in its most general form, while not yet carried out, would appear to be now experimentally feasible.
Anthony James Leggett; Dervis Can Vural
Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions
This Letter investigates the efficiency enhancement achieved by tunnel junction insertion into the InGaN/GaN multi-quantum well (MQW) active region of blue light emitting diodes (LEDs). The peak quantum efficiency of such LED exceeds 100%, but the maximum wall-plug efficiency (WPE) hardly changes. However, due to the increased bias, the WPE peaks at much higher input power, i.e., the WPE droop is significantly delayed, and the output power is strongly enhanced. The main physical reason for this improvement lies in the non-uniform vertical carrier distribution typically observed within InGaN MQWs.
Piprek, Joachim, E-mail: email@example.com [NUSOD Institute LLC, P.O. Box 7204, Newark, Delaware 19714 (United States)
Preparation of Ag Schottky contacts on n-type GaN bulk crystals grown in nitrogen rich atmosphere by the hydride vapor phase epitaxy technique
Electrical properties of Schottky contacts on n-type GaN grown in nitrogen rich atmosphere with different N/Ga ratios by hydride vapor phase epitaxy were investigated. We show that tunneling of electrons from the conduction band of GaN to the metal is dominant in our samples. The quality of Schottky contacts does not only depend on surface preparation but also on the growth conditions of the crystals. Schottky contacts on these crystals show an increasing deterioration when higher N/Ga growth ratios are used. We correlate our results with the presence of negatively charged gallium vacancies in the samples. These charges compensate the positively charged donors and lead to a significant increase in series resistance.
St�bner, R., E-mail: firstname.lastname@example.com; Kolkovsky, Vl.; Weber, J. [Technische Universit�t Dresden, 01062 Dresden (Germany); Leibiger, Gunnar; Habel, Frank [Freiberger Compound Materials GmbH, 09599 Freiberg (Germany)
Type B Accident Investigation Board Report of the UT-Battelle...
cage tops were washed for the next 3 weeks. 701 A-98-LSD-001, Chapter VI, "Operations," Section J, Tunnel Wash Operation, was updated. 70301 Five carts of cage tops were washed...
Spin dependent transport properties of Mn-Ga/MgO/Mn-Ga magnetic tunnel junctions with metal(Mg, Co, Cr) insertion layer
We report a first principles theoretical investigation of spin polarized quantum transport in Mn{sub 2}Ga/MgO/Mn{sub 2}Ga and Mn{sub 3}Ga/MgO/Mn{sub 3}Ga magnetic tunneling junctions (MTJs) with the consideration of metal(Mg, Co, Cr) insertion layer effect. By changing the concentration of Mn, our calculation shows a considerable disparity in transport properties: A tunneling magnetoresistance (TMR) ratio of 852% was obtained for Mn{sub 2}Ga-based MTJs, however, only a 5% TMR ratio for Mn{sub 3}Ga-based MTJs. In addition, the influence of insertion layer has been considered in our calculation. We found the Co insertion layer can increase the TMR of Mn{sub 2}Ga-based MTJ to 904%; however, the Cr insertion layer can decrease the TMR by 668%; A negative TMR ratio can be obtained with Mg insertion layer. Our work gives a comprehensive understanding of the influence of different insertion layer in Mn-Ga based MTJs. It is proved that, due to the transmission can be modulated by the interfacial electronic structure of insertion, the magnetoresistance ratio of Mn{sub 2}Ga/MgO/Mn{sub 2}Ga MTJ can be improved by inserting Co layer.
Liang, S. H.; Tao, L. L.; Liu, D. P., E-mail: email@example.com; Han, X. F., E-mail: firstname.lastname@example.com [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Lu, Y. [Institut Jean Lamour, UMR 7198, CNRS-Nancy Universit�, BP 239, 54506 Vandoeuvre (France)
Type Inferencing and MATLAB to Modelica Translation.
?? Matlab is a proprietary, interactive, dynamically-typed language for technical computing. It is widely used for prototyping algorithms and applications of scientific computations. Since it� (more)
Mohammad, Jahanzeb
Type B Accident Investigation, Subcontractor Employee Personal...
ignited the right leg of his 100% cotton anticontamination (anti-c) coveralls and the plastic bootie. Type B Accident Investigation, Subcontractor Employee Personal Protective...
Playing games with EPR-type experiments
An approach towards quantum games is proposed that uses the unusual probabilities involved in EPR-type experiments directly in two-player games.
Azhar Iqbal
Turbulent Combustion in Type Ia Supernova Models
We review the astrophysical modeling of type Ia supernova explosions and describe numerical methods to implement numerical simulations of these events. Some results of such simulations are discussed.
F. K. Roepke; W. Hillebrandt
Convolution type operators on locally compact groups
Shtein--~erg, Convolution Type Operators on Locally Compact Groups [in Russian],. Manuscript Deposited in the All-Union Institute of Scientific and Technical�...
Fano-type coupling of a bound paramagnetic state with 2D continuum
We analyze an effect of a bound impurity state located at a tunnel distance from a quantum well (QW). The study is focused on the resonance case when the bound state energy lies within the continuum of the QW states. Using the developed theory we calculate spin polarization of 2D holes induced by paramagnetic (Mn) delta-layer in the vicinity of the QW and indirect exchange interaction between two impurities located at a tunnel distance from electron gas.
Rozhansky, I. V. [A.F. Ioffe Physical Technical Institute, 194021 St.Petersburg, Russia and Lappeenranta University of Technology, P.O. Box 20, FI-53851, Lappeenranta (Finland); Averkiev, N. S. [A.F. Ioffe Physical Technical Institute, 194021 St.Petersburg (Russian Federation); L�hderanta, E. [Lappeenranta University of Technology, P.O. Box 20, FI-53851, Lappeenranta (Finland)
Tunnels Issue 2
right ahead, sweetheart, baby-mine," and she began singing softly as she carried him toward home: "Bye, baby bunting/Daddy's gone a-hunting/To get a little rabbit skin/To wrap his baby bunting in .. ." ip pi pi v Whether he was comforted by her singing... say how he would react, for John could be unpredictable. Anna lay onthe bed withthe baby inher arms, and gazed into hissleeping face. ^ "I think I'll call you Vincent," she said softly, "in honor of where you were found." Gradually, she, too, drifted...
Multiple Contributors
scanning tunneling microscopy | EMSL
(3-dimercapto-1-propanol, BAL)significantly reduced extracellular polymeric substances (EPS) expression by Brevundimonas diminuta in suspended cultures at levels just below the...
Office of Environmental Management (EM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergy Cooperation |South Valley ResponsibleSubmissionofDepartmentNo.7-052 ofFocus onANDREW W.
Tunnel | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:Seadov Pty LtdSteen,LtdInformationTulsa, Oklahoma: EnergyTunisia: Energy
Archived Reference Building Type: Medium office
Here you will find past versions of the commercial reference building models for existing buildings constructed in or after 1980, organized by building type and location. A summary of building types and climate zones is available for reference. Current versions are also available.
Here you will find past versions of the commercial reference building models for existing buildings constructed before 1980, organized by building type and location. A summary ofbuilding types and climate zones�is available for reference.�Current versions�are also available.
Fuel oil and Turkey Based Biofuel Energy Rocovery 12,000 Industrial Waste $30,000 $500 $29,500 1500WASTE DESCRIPTION TYPE OF PROJECT POUNDS REDUCED, REUSED, RECYCLED OR CONSERVED IN 2006 WASTE TYPE DESCRIPTION DETAILS * Aerosol Can Disposal System Recycling 528 66 pounds of hazardous waste per unit $7
Archived Reference Building Type: Secondary school
Project Name Project Number Tagging Type
Project Name Project Number Primary Tagging Type Secondary Tagging Type Fish Species Tagging/ Secondary Legal Driver (BiOp, MOA, Accord, etc.) Tagging Purpose Funded Entity Tagging Location Retrieval CWT Recovery Project 2010-036-00 CWT PIT Chinook, coho retrieval, analysis, address PSMFC sampling
Repairing Type Errors in Functional Programs�
Type systems for programming languages can be used by compilers to reject programs which are found to be unsound and which may, therefore, fail to execute successfully. When a program is rejected the programmer must repair it so that it can be type...
McAdam, Bruce J
Archived Reference Building Type: Outpatient health care
Serum markers for type II diabetes mellitus
A method for identifying persons with increased risk of developing type 2 diabetes mellitus utilizing selected biomarkers described hereafter either alone or in combination. The present invention allows for broad based, reliable, screening of large population bases and provides other advantages, including the formulation of effective strategies for characterizing, archiving, and contrasting data from multiple sample types under varying conditions.
Metz, Thomas O; Qian, Wei-Jun; Jacobs, Jon M; Polpitiya, Ashoka D; Camp, II, David G; Smith, Richard D
Testing Type Class Laws Johan Jeuring
]. Instances of Monad should satisfy the following laws: return a>>=k k a m >>=return m m >>=(x k x>>=h) (m>>=k)>>=hTesting Type Class Laws Johan Jeuring Patrik Jansson Cl´audio Amaral Technical Report UU-CS-2012.089 3508 TB Utrecht The Netherlands #12;Testing Type Class Laws Johan Jeuring Utrecht University and Open
WASTE DESCRIPTION TYPE OF PROJECT POUNDS REDUCED, REUSED, RECYCLED OR CONSERVED IN 2004 WASTE TYPE Brake Cleaner Recycling System Mercury Utility Devices Substitution 60 Hazardous Waste $1,750 $2,500 $1 of one PCB spill and clean-up event. Organic Solvents Substitution 678 Hazardous Waste $1,355 $36,500 $26
Advanced Topics in Types and Programming Languages
Advanced Topics in Types and Programming Languages Benjamin C. Pierce, editor The MIT Press Advanced Topics in Types and programming languages / Benjamin C. Pierce, editor p. cm. Includes bibliographical references and index. ISBN 0-262-16228-8 (hc.: alk. paper) 1. Programming languages (Electronic
Pitts, Andrew
Fabry-Prot Interference in Gapped Bilayer Graphene with Broken Anti-Klein Tunneling Anastasia Varlet,1,*
the efficiency of sharp potential steps between the n- and p-type regions, which play the role, Tsukuba 305-0044, Japan (Received 13 June 2014; published 8 September 2014) We report the experimental or the particle energy is varied. In solid-state physics, graphene has proven to be a sui- table material
Schubart, Christoph
Improving Type Ia Supernova Standard Candle Cosmology Measurements Using Observations of Early-Type Host Galaxies
Host Galaxies of Type Ia Supernovae Introduction SN Ia Hosts109 C HAPTER 1 Cosmology, Type Ia Supernovae and HostGalaxies Observations of supernovae have played a role in
Meyers, Joshua Evan
TRIPLE-JUNCTION A-SI SOLAR CELLS WITH HEAVILY DOPED THIN INTERFACE LAYERS AT THE TUNNEL W. Wang, H. Povolny, W. Du, X.B. Liao and X. Deng
TRIPLE-JUNCTION A-SI SOLAR CELLS WITH HEAVILY DOPED THIN INTERFACE LAYERS AT THE TUNNEL JUNCTIONS W of Toledo, Toledo, OH 43606 USA ABSTRACT Triple-junction a-Si based solar cells, having a structure of SS cells and between the middle and bottom component cells on the efficiency of triple- junction solar
Deng, Xunming
Interface magnetism of Co{sub 2}FeGe Heusler alloy layers and magnetoresistance of Co{sub 2}FeGe/MgO/Fe magnetic tunnel junctions
The interface magnetism between Co{sub 2}FeGe Heusler alloy layers and MgO layers was investigated using {sup 57}Fe M�ssbauer spectroscopy. Interface-sensitive samples, where the {sup 57}Fe isotope was used only for the interfacial atomic layer of the Co{sub 2}FeGe layer on the MgO layer, were prepared using atomically controlled alternate deposition. The {sup 57}Fe M�ssbauer spectra of the interface-sensitive samples at room temperature were found similar to those of the bulk-sensitive Co{sub 2}FeGe films in which the {sup 57}Fe isotope was distributed throughout the films. On the other hand, the tunnel magnetoresistance effect of magnetic tunnel junctions with Co{sub 2}FeGe layers as the ferromagnetic electrodes showed strong reduction at room temperature. These results indicate that the strong temperature dependence of the tunneling magnetoresistance of magnetic tunnel junctions using Heusler alloy electrodes cannot be attributed simply to the reduction of the magnetization at the interfaces between the Heusler alloy and insulator layers.
Tanaka, M. A., E-mail: email@example.com; Maezaki, D.; Ishii, T.; Okubo, A.; Mibu, K. [Department of Engineering Physics, Electronics and Mechanics, Nagoya Institute of Technology, Nagoya, Aichi 466-8555 (Japan); Hiramatsu, R.; Ono, T. [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)
Theoretical cosmic Type Ia supernova rates
The aim of this work is the computation of the cosmic Type Ia supernova rates at very high redshifts (z>2). We adopt various progenitor models in order to predict the number of explosions in different scenarios for galaxy formation and to check whether it is possible to select the best delay time distribution model, on the basis of the available observations of Type Ia supernovae. We also computed the Type Ia supernova rate in typical elliptical galaxies of different initial luminous masses and the total amount of iron produced by Type Ia supernovae in each case. It emerges that: it is not easy to select the best delay time distribution scenario from the observational data and this is because the cosmic star formation rate dominates over the distribution function of the delay times; the monolithic collapse scenario predicts an increasing trend of the SN Ia rate at high redshifts whereas the predicted rate in the hierarchical scheme drops dramatically at high redshift; for the elliptical galaxies we note that the predicted maximum of the Type Ia supernova rate depends on the initial galactic mass. The maximum occurs earlier (at about 0.3 Gyr) in the most massive ellipticals, as a consequence of downsizing in star formation. We find that different delay time distributions predict different relations between the Type Ia supernova rate per unit mass at the present time and the color of the parent galaxies and that bluer ellipticals present higher supernova Type Ia rates at the present time.
R. Valiante; F. Matteucci; S. Recchi; F. Calura
Renewable Energy Opportunities by Renovation Type
Renewable energy opportunities should be considered and identified in the earliest stages of Federal project planning and the team should assess the renewable energy options based on the type of...
an Economical Refractory Material", Industrial Heating, 50-of Sialon-Type Materials Newman Spencer Lawrence BerkeleyEXPERIHENTAL PROCEDURES A. The Material L Ml H2 M3 and M4 B.
Spencer, P.N.
Operations and Maintenance for Major Equipment Types
Equipment lies at the heart of all operations and maintenance (O&M) activities. This equipment varies greatly across the Federal sector in age, size, type, model, condition, etc.
The BMW Algebras of Type Dn
The Birman-Murakami-Wenzl algebra (BMW algebra) of type Dn is shown to be free over the quotient of a polynomial algebra of dimension (2^n+1)n!!-(2^(n-1)+1)n! where n!! is the product of the first n odd integers. The Brauer algebra of type Dn is a homomorphic ring image and is also semisimple and free of the same dimesion, but over a different ring. A rewrite system for the Brauer algebra is used in upper bounding the dimension of the BMW algebra. As a consequence or our results, the generalized Temperley-Lieb algebra of type Dn is a subalgebra of the BMW algebra of the same type.
Cohen, Arjeh M; Wales, David B
Corrective Action Decision Document/Closure Report for Corrective Action Unit 476: Area 12 T-Tunnel Muckpile, Nevada Test Site
This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 476, Area 12 T-Tunnel Muckpile. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy, and the U.S. Department of Defense. Corrective Action Unit 476 is comprised of one Corrective Action Site (CAS): � 12-06-02, Muckpile The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 476.
Corrective Action Decision Document/Closure Report for Corrective Action Unit 477: Area 12 N-Tunnel Muckpile, Nevada Test Site
This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 477, N-Tunnel Muckpile. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy, and the U.S. Department of Defense. Corrective Action Unit 477 is comprised of one Corrective Action Site (CAS): � 12-06-03, Muckpile The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure with no further action, by placing use restrictions on CAU 477.
Corrective Action Decision Document/Closure Report for Corrective Action Unit 478: Area 12 T-Tunnel Ponds, Nevada Test Site
This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 478, Area 12 T-Tunnel Ponds. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy (DOE), and the U.S. Department of Defense. Corrective Action Unit 478 is comprised of one corrective action site (CAS): � 12-23-01, Ponds (5) RAD Area The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 478.
Corrective Action Decision Document/Closure Report for Corrective Action Unit 559: T Tunnel Compressor/Blower Pad, Nevada Test Site
This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 559, T-Tunnel Compressor/Blower Pad. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy, and the U.S. Department of Defense. Corrective Action Unit 559 is comprised of one Corrective Action Site (CAS): � 12-25-13, Oil Stained Soil and Concrete The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 559.
Zurek-Kibble Mechanism for the Spontaneous Vortex Formation in Nb-Al/Al{sub ox}/Nb Josephson Tunnel Junctions: New Theory and Experiment
New scaling behavior has been both predicted and observed in the spontaneous production of fluxons in quenched Nb-Al/Al{sub ox}/Nb annular Josephson tunnel junctions (JTJs) as a function of the quench time, {tau}{sub Q}. The probability f{sub 1} to trap a single defect during the normal-metal-superconductor phase transition clearly follows an allometric dependence on {tau}{sub Q} with a scaling exponent {sigma}=0.5, as predicted from the Zurek-Kibble mechanism for realistic JTJs formed by strongly coupled superconductors. This definitive experiment replaces one reported by us earlier, in which an idealized model was used that predicted {sigma}=0.25, commensurate with the then much poorer data. Our experiment remains the only condensed matter experiment to date to have measured a scaling exponent with any reliability.
Monaco, R. [Istituto di Cibernetica del C.N.R., 80078, Pozzuoli (Italy) and Unita INFM-Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Italy); Mygind, J.; Aaroe, M. [Department of Physics, B309, Technical University of Denmark, DK-2800 Lyngby (Denmark); Rivers, R.J. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Koshelets, V.P. [Institute of Radio Engineering and Electronics, Russian Academy of Science, Mokhovaya 11, Building 7, 125009, Moscow (Russian Federation)
Amendment 1 - Dry-type power transformers
Specifies requirements for dry-type power transformers (including auto-transformers) having values of highest voltage for equipment up to and including 36 kV. The following small and special dry-type transformers are not covered by this standard: -instrument transformers (covered by IEC 60185 and 60186); -transformers for static convertors (covered by IEC 60084, 60119 and 60146). Where IEC standards do not exist for other special transformers, this standard may be applicable as a whole or in part.
International Electrotechnical Commission. Geneva
Types of Land Degradation in Bhutan
of other nutrients Possible eutrophication or contamination of streams Excessive P fertiliser (potato and apple crops) Possible excess P fertiliser applied to apples in W Bhutan Eutrophicatio n unlikely in fast flowing streams... highly vulnerable to surface erosion Effluents from plants, workshops & urban waste Not extensive � but some cases around Thimphu & in South Table 2: Types of Degradation (In Situ Degradation-Physical) 1. Soil Type: Topsoil...
Chencho Norbu et al,
Trace element geochemistry of ordinary chondrite chondrules: the type I/type II chondrule dichotomy
We report trace element concentrations of silicate phases in chondrules from LL3 ordinary chondrites Bishunpur and Semarkona. Results are similar to previously reported data for carbonaceous chondrites, with rare earth element (REE) concentrations increasing in the sequence olivine ~ 10 K/h) than type I chondrules. Appreciable Na concentrations (3-221 ppm) are measured in olivine from both chondrule types; type II chondrules seem to have behaved as closed systems, which may require chondrule formation in the vicinity of protoplanets or planetesimals. At any rate, higher solid concentrations in type II chondrule forming regions may explain the higher oxygen fugacities they record compared to type I chondrules. Type I and type II chondrules formed in different environments and the correlation between high solid concentrations and/or oxygen fugacities with rapid cooling rates is a key constraint that chondrule formation models must account for.
Jacquet, Emmanuel; Gounelle, Matthieu
Evaluation of magnetic flux distribution from magnetic domains in [Co/Pd] nanowires by magnetic domain scope method using contact-scanning of tunneling magnetoresistive sensor
Current-driven magnetic domain wall motions in magnetic nanowires have attracted great interests for physical studies and engineering applications. The magnetic force microscope (MFM) is widely used for indirect verification of domain locations in nanowires, where relative magnetic force between the local domains and the MFM probe is used for detection. However, there is an occasional problem that the magnetic moments of MFM probe influenced and/or rotated the magnetic states in the low-moment nanowires. To solve this issue, the �magnetic domain scope for wide area with nano-order resolution (nano-MDS)� method has been proposed recently that could detect the magnetic flux distribution from the specimen directly by scanning of tunneling magnetoresistive field sensor. In this study, magnetic domain structure in nanowires was investigated by both MFM and nano-MDS, and the leakage magnetic flux density from the nanowires was measured quantitatively by nano-MDS. Specimen nanowires consisted from [Co (0.3)/Pd (1.2)]{sub 21}/Ru(3) films (units in nm) with perpendicular magnetic anisotropy were fabricated onto Si substrates by dual ion beam sputtering and e-beam lithography. The length and the width of the fabricated nanowires are 20??m and 150?nm. We have succeeded to obtain not only the remanent domain images with the detection of up and down magnetizations as similar as those by MFM but also magnetic flux density distribution from nanowires directly by nano-MDS. The obtained value of maximum leakage magnetic flux by nano-MDS is in good agreement with that of coercivity by magneto-optical Kerr effect microscopy. By changing the protective diamond-like-carbon film thickness on tunneling magnetoresistive sensor, the three-dimensional spatial distribution of leakage magnetic flux could be evaluated.
Okuda, Mitsunobu, E-mail: firstname.lastname@example.com; Miyamoto, Yasuyoshi; Miyashita, Eiichi; Hayashi, Naoto [NHK Science and Technology Research Laboratories, 1-10-11 Kinuta Setagaya, Tokyo 157-8510 (Japan)
Virgo Early-Type Dwarfs in ALFALFA
Early-type dwarf galaxies dominate cluster populations, but their formation and evolutionary histories are poorly understood. The ALFALFA (Arecibo Legacy Fast ALFA) survey has completed observations of the Virgo Cluster in the declination range of 6 - 16 degrees. Less than 2% of the early-type dwarf population is detected, a significantly lower fraction than reported in previous papers based on more limited samples. In contrast ~30 of the irregular/BCD dwarf population is detected. The detected early-type galaxies tend to be located in the outer regions of the cluster, with a concentration in the direction of the M Cloud. Many show evidence for ongoing/recent star formation. Galaxies such as these may be undergoing morphological transition due to cluster environmental effects.
Koopmann, Rebecca A
Rebecca A. Koopmann
Fiber-type dosimeter with improved illuminator
A single-piece, molded plastic, Cassigrainian-type condenser arrangement is incorporated in a tubular-shaped personal pocket dosimeter of the type which combines an ionization chamber with an optically-read fiber electrometer to provide improved illumination of the electrometer fiber. The condenser routes incoming light from one end of the dosimeter tubular housing around a central axis charging pin assembly and focuses the light at low angles to the axis so that it falls within the acceptance angle of the electrometer fiber objective lens viewed through an eyepiece lens disposed in the opposite end of the dosimeter. This results in improved fiber illumination and fiber image contrast.
Fox, Richard J. (Oak Ridge, TN)
Fox, R.J.
Transformations of $W$-Type Entangled States
The transformations of $W$-type entangled states by using local operations assisted with classical communication are investigated. For this purpose, a parametrization of the $W$-type states which remains invariant under local unitary transformations is proposed and a complete characterization of the local operations carried out by a single party is given. These are used for deriving the necessary and sufficient conditions for deterministic transformations. A convenient upper bound for the maximum probability of distillation of arbitrary target states is also found.
S. K?nta?; S. Turgut
Programming with Dependent Types in Coq Matthieu Sozeau
, generating Type-checking conditions. + Practical success ; t : T P[t/x] t : { x : T | P } t : { x : T | P, generating Type-checking conditions. + Practical success ; No strong safety guarantee in PVS. t : T P typing algorithm for subset types, generating Type-checking conditions. + Practical success ; No strong
Sozeau, Matthieu
Title: Academic Advisor Employment Type: Administrative Professional
Title: Academic Advisor Employment Type: Administrative Professional College: Engineering is seeking a full time academic advisor to collaborate with faculty and ECE staff to coordinate and advise faculty, 250 undergraduate students and 150 graduate students. The advisor will work closely together
Reference Buildings by Building Type: Secondary school
Office of Energy Efficiency and Renewable Energy (EERE)
In addition to the ZIP file for each building type, you can directly view the "scorecard" spreadsheet that summarizes the inputs and results for each location. This Microsoft Excel spreadsheet is also included in the ZIP file. For version 1.4, only the IDF file is included.
Reference Buildings by Building Type: Primary school
mathematics Study program cycle and type
mathematics academic study programmm 11 #12;12 #12;· Study program cycle and type: First cycle academic study program. · AAnnttiicciippaatteedd aaccaaddeemmiicc ttiittllee:: Bachelor in Mathematics ggooaallss:: The principal goal of the academic study program in Mathematics is to qualify its graduates
�?umer, Slobodan
Ankle Injury TYPES OF ANKLE INJURIES
Ankle Injury TYPES OF ANKLE INJURIES: Ankle injuries can be acute or chronic in nature. Inverting (turning in) of the ankle, accounts for most acute injuries. Damage occurs when ankle is twisted or moved beyond its normal range. Overuse of the ankle can cause tearing of the ligaments or strain tendon fibers
Virginia Tech
Graduate Assistant Stipend Enhancement Project Proposal Type
1 Graduate Assistant Stipend Enhancement Project Proposal Type The Graduate Assistant Stipend Strategic Plan. Goals The Graduate Assistant Stipend Enhancement project consists of two programs: the Great. Fundamentally, the project seeks to increase the number of graduate students who receive assistantships
Karonis, Nicholas T.
Data Management Plan Types of Data
Data Management Plan Types of Data The research described herein will lead to the discovery of new will be followed by electrochemistry, Raman spectroscopy and optical spectroscopy. All data will be stored electronically in word processing documents. Data Standards All data will be stored in an electronic format
Tam, Tin-Yau
Deforestation of Functional Programs through Type Inference
Deforestation of Functional Programs through Type Inference Olaf Chitil Lehrstuhl f¨ur Informatik II, RWTH Aachen, Germany email@example.com Abstract. Deforestation optimises structures. Short cut deforestation is a deforestation method which is based on a single, local
Kent, University of
Types of Utility Energy Service Contracts
Several types of contracts are used as utility energy service contracts (UESCs). Many agency sites procure electricity services under a contract with the local utility, and most of these contracts have provisions that can also cover energy efficiency projects. Agencies not covered by such agreements may enter contracts with the utility for the sole purpose of implementing energy projects.
Reference Buildings by Building Type: Hospital
Reference Buildings by Building Type: Large office