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Simple solar spectral model for direct and diffuse irradiance on horizontal and tilted planes at the earth's surface for cloudless atmospheres
SciTech Connect (OSTI)
A new, simple model for calculating clear-sky direct and diffuse spectral irradiance on horizontal and tilted surfaces is presented. The model is based on previously reported simple algorithms and on comparisons with rigorous radiative transfer calculations and limited outdoor measurements. Equations for direct normal irradiance are outlined; and include: Raleigh scattering; aerosol scattering and absorption; water vapor absorption; and ozone and uniformly mixed gas absorption. Inputs to the model include solar zenith angle, collector tilt angle, atmospheric turbidity, amount of ozone and precipitable water vapor, surface pressure, and ground albedo. The model calculates terrestrial spectra from 0.3 to 4.0 ..mu..m with approximately 10 nm resolution. A major goal of this work is to provide researchers with the capability to calculate spectral irradiance for different atmospheric conditions and different collector geometries using microcomputers. A listing of the computer program is provided.
Bird, R.; Riordan, C.
Notes 16. Analysis of tilting pad bearings
E-Print Network [OSTI]
NOTES 16. STATIC AND DYNAMIC FORCED PERFORMANCE OF TILTING PAD BEARINGS: ANALYSIS INCLUDING PIVOT STIFFNESS Dr. Luis San Andr?s Mast-Childs Professor August 2010 SUMMARY Work in progress ? still a lot of be done Introduction.... ANALYSIS OF TILTING PAD BEARINGS ? Luis San Andr?s (2010) 2 ANALYSIS Rocker and spherical pivots in tilting pad allow nearly frictionless pad rotation. An ideal rocker TPB, shown in Fig. 3(a), allows the pad to roll without slipping around a cylindrical...
San Andres, Luis
Large optics inspection, tilting, and washing stand
DOE Patents [OSTI]
A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.
Ayers, Marion Jay (Brentwood, CA); Ayers, Shannon Lee (Brentwood, CA)
Ayers, Marion Jay; Ayers, Shannon Lee
Solar: monthly latitude tilt GIS data at 40km resolution for...
Open Energy Info (EERE)
of aerosols in the atmosphere to calculate the monthly average daily total insolation (sun and sky) falling on a horizontal surface. Existing ground measurement stations are used...
Solar: monthly latitude tilt GIS data at 40km resolution for Bangladesh
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Combined Scanning Transmission Electron Microscopy Tilt- and Focal Series
In this study, a combined tilt- and focal series is proposed as a new recording scheme for high-angle annular dark-field scanning transmission electron microscopy (STEM) tomography. Three-dimensional (3D) data were acquired by mechanically tilting the specimen, and recording a through-focal series at each tilt direction. The sample was a whole-mount macrophage cell with embedded gold nanoparticles. The tilt focal algebraic reconstruction technique (TF-ART) is introduced as a new algorithm to reconstruct tomograms from such combined tilt- and focal series. The feasibility of TF-ART was demonstrated by 3D reconstruction of the experimental 3D data. The results were compared with a conventional STEM tilt series of a similar sample. The combined tilt- and focal series led to smaller missing wedge artifacts, and a higher axial resolution than obtained for the STEM tilt series, thus improving on one of the main issues of tilt series-based electron tomography.
Dahmen, Tim [German Research Center for Artificial Intelligence (DFKI), Germany] [German Research Center for Artificial Intelligence (DFKI), Germany; Baudoin, Jean-Pierre G [ORNL] [ORNL; Lupini, Andrew R [ORNL] [ORNL; Kubel, Christian [Karlsruhe Institute of Technology, Leopoldshafen, Germany] [Karlsruhe Institute of Technology, Leopoldshafen, Germany; Slusallek, Phillip [German Research Center for Artificial Intelligence (DFKI), Germany] [German Research Center for Artificial Intelligence (DFKI), Germany; De Jonge, Niels [ORNL] [ORNL
Tilt assembly for tracking solar collector assembly
A tilt assembly is used with a solar collector assembly of the type comprising a frame, supporting a solar collector, for movement about a tilt axis by pivoting a drive element between first and second orientations. The tilt assembly comprises a drive element coupler connected to the drive element and a driver, the driver comprising a drive frame, a drive arm and a drive arm driver. The drive arm is mounted to the drive frame for pivotal movement about a drive arm axis. Movement on the drive arm mimics movement of the drive element. Drive element couplers can extend in opposite directions from the outer portion of the drive arm, whereby the assembly can be used between adjacent solar collector assemblies in a row of solar collector assemblies.
Almy, Charles; Peurach, John; Sandler, Reuben
The cost of noise reduction in commercial tilt rotor aircraft
The relationship between direct operating cost and departure noise annoyance was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various ...
Faulkner, Henry B.
Ram pressure stripping of tilted galaxies
Ram pressure stripping of galaxies in clusters can yield gas deficient disks. Previous numerical simulations based on various approaches suggested that, except for near edge-on disk orientations, the amount of stripping depends very little on the inclination angle. Following our previous study of face-on stripping, we extend the set of parameters with the disk tilt angle and explore in detail the effects of the ram pressure on the interstellar content (ISM) of tilted galaxies that orbit in various environments of clusters, with compact or extended distributions of the intra-cluster medium (ICM). We further study how results of numerical simulations could be estimated analytically. A grid of numerical simulations with varying parameters is produced using the tree/SPH code GADGET with a modified method for calculating the ISM-ICM interaction. These SPH calculations extend the set of existing results obtained from different codes using various numerical techniques. The simulations confirm the general trend of le...
Jachym, P; Palous, J; Combes, F
Prediction of tilted capillary barrier performance
Capillary barriers, consisting of tilted fine-over-coarse layers under unsaturated conditions, have been suggested as landfill covers to divert water infiltration away from sensitive underground regions, especially for arid and semi-arid regions. The Hydrological Evaluation of Landfill Performance (HELP) computer code is an evaluation tool for landfill covers used by designers and regulators. HELP is a quasi-two-dimensional model that predicts moisture movement into and through the underground soil and waste layers. Processes modeled within HELP include precipitation, runoff, evapotranspiration, unsaturated vertical drainage, saturated lateral drainage, and leakage through liners. Unfortunately, multidimensional unsaturated flow phenomena that are necessary for evaluating tilted capillary barriers are not included in HELP. Differences between the predictions of the HELP and those from a multidimensional unsaturated flow code are presented to assess the two different approaches. Comparisons are presented for the landfill covers including capillary barrier configurations at the Alternative Landfill Cover Demonstration (ALCD) being conducted at Sandia.
Webb, S.W.; McCord, J.T.; Dwyer, S.F.
Stabilizing windings for tilting and shifting modes
This invention relates to passive conducting loops for stabilizing a plasma ring against unstable tilting and/or shifting modes. To this end, for example, plasma ring in a spheromak is stabilized by a set of four figure-8 shaped loops having one pair on one side of the plasma and one pair on the other side with each pair comprising two loops whose axes are transverse to each other.
Jardin, Stephen C. (Princeton, NJ); Christensen, Uffe R. (Princeton, NJ)
296 J. Opt. Soc. Am. A/Vol. 13, No. 2/February 1996 T. Erdogan and J. E. Sipe Tilted fiber phase gratings
optical-fiber phase grating. Numerical predictions of the effects of grating tilt on the spectral spectra of strong gratings written by ultraviolet irradiation of deuterium- sensitized fiber with grating and the experimental results. © 1996 Optical Society of America 1. INTRODUCTION The fiber phase grating written
Sipe,J. E.
Geometric Model of a Narrow Tilting CAR using Robotics formalism
- structured multibody system composed of n bodies (links) where the chassis is the mobile base and the wheels tilting car "Lumeneo Smera" [4] through the analysis of its tilting mechanism. To model a complex system. Robotic representation of a multibody system The car can be seen as a mobile robot which is a tree
Boyer, Edmond
Position vs. Velocity Control for Tilt-Based Interaction Robert J. Teather*
like a steering wheel, and "marble maze" games where tilting rolls a ball to simulate gravity. Although's subjective impression of the system. 2 RELATED WORK 2.1 Tilt-Based Interaction Tilt control has long been
MacKenzie, Scott
In order to study the properties and effects of high Galactic latitude dust, we present an analysis of 373,303 galaxies selected from the Galaxy Evolution Explorer All-Sky Survey and Wide-field Infrared Explorer All-Sky Data Release. By examining the variation in aggregate ultraviolet colors and number density of these galaxies, we measure the extinction curve at high latitude. We additionally consider a population of spectroscopically selected galaxies from the Sloan Digital Sky Survey to measure extinction in the optical. We find that dust at high latitude is neither quantitatively nor qualitatively consistent with standard reddening laws. Extinction in the FUV and NUV is {approx}10% and {approx}35% higher than expected, with significant variation across the sky. We find that no single R{sub V} parameter fits both the optical and ultraviolet extinction at high latitude, and that while both show detectable variation across the sky, these variations are not related. We propose that the overall trends we detect likely stem from an increase in very small silicate grains in the interstellar medium.
Peek, J. E. G.; Schiminovich, David, E-mail: firstname.lastname@example.com [Department of Astronomy, Columbia University, New York, NY (United States)
A Neural Network Model of Visual Tilt Aftereffects
RF-LISSOM, a self-organizing model of laterally connected orientation maps in the primary visual cortex, was used to study the psychological phenomenon known as the tilt aftereffect. The same self-organizing processes that are responsible for the long-term development of the map and its lateral connections are shown to result in tilt aftereffects over short time scales in the adult. The model allows observing large numbers of neurons and connections simultaneously, making it possible to relate higher-level phenomenato low-level events, which is difficult to do experimentally. The results give computational support for the idea that direct tilt aftereffects arise from adaptive lateral interactions between feature detectors, as has long been surmised. They also suggest that indirect effects could result from the conservation of synaptic resourcesduring this process. The model thus provides a unified computational explanation of self-organization and both direct and indirect tilt aftereff...
TILT POUR TRIALS AND ANALYSIS Bob Bryant1
TILT POUR TRIALS AND ANALYSIS Bob Bryant1 , Kent D. Carlson2 , Shouzhu Ou2 , Christoph Beckermann2 reduce inclusion severity, compared to standard techniques. Bryant, R., Carlson, K.D., Ou, S
Beckermann, Christoph
Laser Guide Star Adaptive Optics without Tip-tilt
Adaptive optics (AO) systems allow a telescope to reach its diffraction limit at near infrared wavelengths. But to achieve this, a bright natural guide star (NGS) is needed for the wavefront sensing, severely limiting the fraction of the sky over which AO can be used. To some extent this can be overcome with a laser guide star (LGS). While the laser can be pointed anywhere in the sky, one still needs to have a natural star, albeit fainter, reasonably close to correct the image motion (tip-tilt) to which laser guide stars are insensitive. There are in fact many astronomical targets without suitable tip-tilt stars, but for which the enhanced resolution obtained with the Laser Guide Star Facility (LGSF) would still be very beneficial. This article explores what adaptive optics performance one might expect if one dispenses with the tip-tilt star, and in what situations this mode of observing might be needed.
R. Davies; S. Rabien; C. Lidman; M. Le Louarn; M. Kasper; N. M. Forster Schreiber; V. Roccatagliata; N. Ageorges; P. Amico; C. Dumas; F. Mannucci
Method to fabricate a tilted logpile photonic crystal
A method to fabricate a tilted logpile photonic crystal requires only two lithographic exposures and does not require mask repositioning between exposures. The mask and photoresist-coated substrate are spaced a fixed and constant distance apart using a spacer and the stack is clamped together. The stack is then tilted at a crystallographic symmetry angle (e.g., 45 degrees) relative to the X-ray beam and rotated about the surface normal until the mask is aligned with the X-ray beam. The stack is then rotated in plane by a small stitching angle and exposed to the X-ray beam to pattern the first half of the structure. The stack is then rotated by 180.degree. about the normal and a second exposure patterns the remaining half of the structure. The method can use commercially available DXRL scanner technology and LIGA processes to fabricate large-area, high-quality tilted logpile photonic crystals.
Williams, John D. (Albuquerque, NM); Sweatt, William C. (Albuquerque, NM)
The cost of noise reduction for departure and arrival operations of commercial tilt rotor aircraft
The relationship between direct operating cost (DOC) and noise annoyance due to a departure and an arrival operation was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt ...
Temporal variations of solar rotation rate at high latitudes
Frequency splitting coefficients from Global Oscillation Network Group (GONG) and Michelson Doppler Imager (MDI) observations covering the period 1995--2001 are used to study temporal variations in the solar rotation rate at high latitudes. The torsional oscillation pattern in the Sun is known to penetrate to a depth of about $0.1R_\\odot$ with alternate bands of faster and slower rotating plasma. At lower latitudes the bands move towards equator with time. At higher latitudes, however, the bands appear to move towards the poles. This is similar to the observed pole-ward movement of large scale magnetic fields at high latitudes. This also supports theoretical results of pole-ward moving bands at high latitudes in some mean field dynamo models. The polar rotation rate is found to decrease between 1995 and 1999 after which it has started increasing.
H. M. Antia; Sarbani Basu
Common origin of positive ionospheric storms at middle latitudes and the geomagnetic activity effect at low latitudes
The author looks for a correlation between two different atmospheric effects. They are a positive atmospheric storm (an anomalous increase in the F2 region ionization density), observed at middle latitudes, and the geomagnetic activity effect (the anomalous changes of temperature and gas density seen in the thermosphere), observed at low latitudes. A temporal correlation is sought to test the argument that both of these effects are the result of travelling atmospheric disturbances (TAD). A TAD is a pulselike atmospheric wave thought to be generated by substorm activity, and to propagate with high velocity (600 m/s) from polar latitudes toward equatorial latitudes. The author looks at data from five separate events correlating magnetic, ionospheric, and neutral atmospheric measurements. The conclusion is that there is a positive correlation between magnetic substorm activity at high latitudes, and positive ionospheric storms at middle latitudes and geomagnetic activity at low latitudes. The time correlations are consistent with high propagation speeds between these events. The author also presents arguments which indicate that the middle latitude positive ionospheric storms are not the result of electric field effects.
Proelss, G.W. (Universitaet Bonn (Germany))
EIS-0039: Motor Gasoline Deregulation and the Gasoline Tilt
Broader source: Energy.gov [DOE]
The Economic Regulatory Administration developed this EIS to evaluate the environmental impacts, including social and economic impacts, that may result from either of two proposed regulatory changes: (1) the exemption of motor gasoline from the Department of Energy's Mandatory Petroleum Price and Allocation Regulations, and (2) the adoption of the gasoline tilt, a proposed regulation that would allow refiners to recover an additional amount of their total increased costs on gasoline.
Splay and tilt energy of bipolar lipid membranes
Archaea organisms are able to survive in extremely aggressive environment. It is thought that such resistance, at least, in part is sustained by unique properties of archaea membrane. The membrane consists of so called bolalipids, which has two polar heads joined by two hydrocarbon chains. Thus bolalipids can exist in two conformations: i) polar heads are located at different sides of bolalipid layer, so called, O-shape; ii) polar heads are located at the same side of the layer, so called, U-shape. Both polar heads and chains are chemically different from those for conventional lipids. In the present study we develop basis for theory of elasticity of bolalipid membranes. Deformations of splay, tilt and Gaussian curvature are considered. We show that energetic contributions of tilt deformation from two surfaces of bolalipid layer are additive, as well as Gaussian curvature, while splay deformations yield a cross-term. The presence of U-shapes is taken into account in terms of the layer spontaneous curvature. Estimation of tilt modulus and possible experiments allowing to measure splay moduli are described.
Timur R. Galimzyanov; Peter I. Kuzmin; Peter Pohl; Sergey A. Akimov
IRRADIATION EXPERIMENTS & FACILITIES AT BNL: BLIP & NSLS II Peter Wanderer Superconducting Magnet). Current user: LBNE materials for Project X. · Long Baseline Neutrino Experiment Abandoned gold mine
McDonald, Kirk
Conjugate High Latitude Measurements along the 40 Magnetic Meridian
Conjugate High Latitude Measurements along the 40º Magnetic Meridian: Autonomous Adaptive Low the 2014 season marked as red squares. #12;Autonomous Adaptive Low-Power Instrument #12;Conjugate observations of Travelling Convection Vorticies produced by solar wind pressure
Michigan, University of
Electronic properties of graphite in tilted magnetic fields
The minimal nearest-neighbor tight-binding model with the Peierls substitution is employed to describe the electronic structure of Bernal-stacked graphite subject to tilted magnetic fields. We show that while the presence of the in-plane component of the magnetic field has a negligible effect on the Landau level structure at the K point of the graphite Brillouin zone, at the H point it leads to the experimentally observable splitting of Landau levels which grows approximately linearly with the in-plane field intensity.
Goncharuk, Nataliya A.; Smr?ka, Ludv�k [Institute of Physics, Academy of Science of the Czech Republic, v. v. i., Cukrovarnick� 10, 162 53 Praha 6 (Czech Republic)
File:NREL-asia-tilt.pdf | Open Energy Information
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Tilting the Primordial Power Spectrum with Bulk Viscosity
Within the context of the cold dark matter model, current observations suggest that inflationary models which generate a tilted primordial power spectrum with negligible gravitational waves provide the most promising mechanism for explaining large scale clustering. The general form of the inflationary potential which produces such a spectrum is a hyperbolic function and is interpreted physically as a bulk viscous stress contribution to the energy-momentum of a perfect baryotropic fluid. This is equivalent to expanding the equation of state as a truncated Taylor series. Particle physics models which lead to such a potential are discussed.
James E. Lidsey
The effects of gantry tilt on breast dose and image noise in cardiac CT
Purpose: This study investigated the effects of tilted-gantry acquisition on image noise and glandular breast dose in females during cardiac computed tomography (CT) scans. Reducing the dose to glandular breast tissue is important due to its high radiosensitivity and limited diagnostic significance in cardiac CT scans.Methods: Tilted-gantry acquisition was investigated through computer simulations and experimental measurements. Upon IRB approval, eight voxelized phantoms were constructed from previously acquired cardiac CT datasets. Monte Carlo simulations quantified the dose deposited in glandular breast tissue over a range of tilt angles. The effects of tilted-gantry acquisition on breast dose were measured on a clinical CT scanner (CT750HD, GE Healthcare) using an anthropomorphic phantom with MOSFET dosimeters in the breast regions. In both simulations and experiments, scans were performed at gantry tilt angles of 0��30�, in 5� increments. The percent change in breast dose was calculated relative to the nontilted scan for all tilt angles. The percent change in noise standard deviation due to gantry tilt was calculated in all reconstructed simulated and experimental images.Results: Tilting the gantry reduced the breast dose in all simulated and experimental phantoms, with generally greater dose reduction at increased gantry tilts. For example, at 30� gantry tilt, the dosimeters located in the superior, middle, and inferior breast regions measured dose reductions of 74%, 61%, and 9%, respectively. The simulations estimated 0%�30% total breast dose reduction across the eight phantoms and range of tilt angles. However, tilted-gantry acquisition also increased the noise standard deviation in the simulated phantoms by 2%�50% due to increased pathlength through the iodine-filled heart. The experimental phantom, which did not contain iodine in the blood, demonstrated decreased breast dose and decreased noise at all gantry tilt angles.Conclusions: Tilting the gantry reduced the dose to the breast, while also increasing noise standard deviation. Overall, the noise increase outweighed the dose reduction for the eight voxelized phantoms, suggesting that tilted gantry acquisition may not be beneficial for reducing breast dose while maintaining image quality.
Hoppe, Michael E.; Gandhi, Diksha; Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States)] [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States); Stevens, Grant M. [GE Healthcare, Waukesha, Wisconsin 53188 (United States)] [GE Healthcare, Waukesha, Wisconsin 53188 (United States); Foley, W. Dennis [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)] [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)
Head tilt during driving DANIEL C. ZIKOVITZ and LAURENCE R. HARRIS *
Head tilt during driving DANIEL C. ZIKOVITZ ² and LAURENCE R. HARRIS² * Departments of ² Biology and Psychology, York University, Toronto, Ontario M3J 1P3, Canada Keywords: Driving behaviour; Head tilt; Vision with the visually-available estimate of the curvature of the road (r 2 = 0.86) but not with the centripetal force (r
Harris, Laurence R.
The role of tilted heating in the evolution of the MJO Cara-Lyn Lappen1
The role of tilted heating in the evolution of the MJO Cara-Lyn Lappen1 and Courtney Schumacher2 1 the role of tilted heating in the evolution of the MJO. It is believed that the inability of many general heating distributions. Given the MJO's importance in tropical climate, we need to better understand what
Self-Optimization of Antenna Tilt and Pilot Power for Dedicated Channels
Self-Optimization of Antenna Tilt and Pilot Power for Dedicated Channels Abstract-- In Radio Access Networks (RAN), fixed configurations result in poor network efficiency. This sub- optimal performance present a framework for a self-optimizing RAN, which adapts Antenna Tilt and Pilot Power according
Paris-Sud XI, Université de
Escape configuration lattice near the nematic-isotropic transition: Tilt analogue of blue phases
We predict the possible existence of a new phase of liquid crystals near the nematic-isotropic ($ NI $) transition. This phase is an achiral, tilt-analogue of the blue phase and is composed of a lattice of {\\em double-tilt}, escape-configuration cylinders. We discuss the structure and the stability of this phase and provide an estimate of the lattice parameter.
Buddhapriya Chakrabarti; Yashodhan Hatwalne; N. V. Madhusudana
Design and development of a 329-segment tip-tilt piston mirror array for space-based adaptive optics
Design and development of a 329-segment tip-tilt piston mirror array for space-based adaptive. It consists of 329-hexagonal segments on a 600 m pitch, each with tip/tilt and piston degrees of freedom
Precision tip-tilt-piston actuator that provides exact constraint
A precision device which can precisely actuate three degrees of freedom of an optic mount, commonly referred to as tip, tilt, and piston. The device consists of three identical flexure mechanisms, an optic mount to be supported and positioned, a structure that supports the flexure mechanisms, and three commercially available linear actuators. The advantages of the precision device is in the arrangement of the constraints offered by the flexure mechanism and not in the particular design of the flexure mechanisms, as other types of mechanisms could be substituted. Each flexure mechanism constrains two degrees of freedom in the plane of the mechanisms and one direction is actuated. All other degrees of freedom are free to move within the range of flexure mechanisms. Typically, three flexure mechanisms are equally spaced in angle about to optic mount and arranged so that each actuated degree of freedom is perpendicular to the plane formed by the optic mount. This arrangement exactly constrains the optic mount and allows arbitrary actuated movement of the plane within the range of the flexure mechanisms. Each flexure mechanism provides a mechanical advantage, typically on the order of 5:1, between the commercially available actuator and the functional point on the optic mount. This improves resolution by the same ratio and stiffness by the square of the ratio.
Hale, Layton C. (Livermore, CA)
Method for removing tilt control in adaptive optics systems
A new adaptive optics system and method of operation are disclosed, whereby the method removes tilt control, and includes the steps of using a steering mirror to steer a wavefront in the desired direction, for aiming an impinging aberrated light beam in the direction of a deformable mirror. The deformable mirror has its surface deformed selectively by means of a plurality of actuators, and compensates, at least partially, for existing aberrations in the light beam. The light beam is split into an output beam and a sample beam, and the sample beam is sampled using a wavefront sensor. The sampled signals are converted into corresponding electrical signals for driving a controller, which, in turn, drives the deformable mirror in a feedback loop in response to the sampled signals, for compensating for aberrations in the wavefront. To this purpose, a displacement error (gradient) of the wavefront is measured, and adjusted by a modified gain matrix, which satisfies the following equation: G{prime} = (I{minus}X(X{sup T} X){sup {minus}1}X{sup T})G(I{minus}A). 3 figs.
Salmon, J.T.
A new adaptive optics system and method of operation, whereby the method removes tilt control, and includes the steps of using a steering mirror to steer a wavefront in the desired direction, for aiming an impinging aberrated light beam in the direction of a deformable mirror. The deformable mirror has its surface deformed selectively by means of a plurality of actuators, and compensates, at least partially, for existing aberrations in the light beam. The light beam is split into an output beam and a sample beam, and the sample beam is sampled using a wavefront sensor. The sampled signals are converted into corresponding electrical signals for driving a controller, which, in turn, drives the deformable mirror in a feedback loop in response to the sampled signals, for compensating for aberrations in the wavefront. To this purpose, a displacement error (gradient) of the wavefront is measured, and adjusted by a modified gain matrix, which satisfies the following equation: G'=(I-X(X.sup.T X).sup.-1 X.sup.T)G(I-A)
Salmon, Joseph Thaddeus (Livermore, CA)
Phonon thermal transport through tilt grain boundaries in strontium titanate
In this work, we perform nonequilibrium molecular dynamics simulations to study phonon scattering at two tilt grain boundaries (GBs) in SrTiO{sub 3}. Mode-wise energy transmission coefficients are obtained based on phonon wave-packet dynamics simulations. The Kapitza conductance is then quantified using a lattice dynamics approach. The obtained results of the Kapitza conductance of both GBs compare well with those obtained by the direct method, except for the temperature dependence. Contrary to common belief, the results of this work show that the optical modes in SrTiO{sub 3} contribute significantly to phonon thermal transport, accounting for over 50% of the Kapitza conductance. To understand the effect of the GB structural disorder on phonon transport, we compare the local phonon density of states of the atoms in the GB region with that in the single crystalline grain region. Our results show that the excess vibrational modes introduced by the structural disorder do not have a significant effect on phonon scattering at the GBs, but the absence of certain modes in the GB region appears to be responsible for phonon reflections at GBs. This work has also demonstrated phonon mode conversion and simultaneous generation of new modes. Some of the new modes have the same frequency as the initial wave packet, while some have the same wave vector but lower frequencies.
Zheng, Zexi; Chen, Xiang; Yang, Shengfeng; Xiong, Liming; Chen, Youping [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States); Deng, Bowen; Chernatynskiy, Aleksandr [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)
Tilted CDM versus WDM in the Subgalactic Scuffle
Although the currently favored cold dark matter plus cosmological constant model (LCDM) has proven to be remarkably successful on large scales, on subgalactic scales it faces some potentially fatal difficulties; these include over-producing dwarf satellite galaxies and predicting excessive central densities in dark halos. Among the most natural cosmological solutions to these problems is to replace cold dark matter with a warm species (LWDM). The warm component acts to reduce the small-scale power, resulting in fewer galactic subhalos and lower halo central densities. An alternative model with a mild ``tilt'' in the inflationary power spectrum (TLCDM; n =0.9) similarly reduces the central densities of dark halos, although the substructure abundance remains relatively high. Here I argue that because dwarf galaxy formation should be suppressed in the presence of a strong ionizing background, favored LWDM models will generally under-predict the observed abundance of dwarf galaxies. The satellite count for TLCDM fairs much better, as long as the photoionization effect is taken into account. TLCDM provides a more successful alternative to LWDM on subgalactic scales with the added attraction that it relies on only a minor, natural adjustment to the standard framework of CDM.
James S. Bullock
Safer Food with Irradiation
This publication answers questions about food irradiation and how it helps prevent foodborne illnesses. Included are explanations of how irradiation works and its benefits. Irradiation is a safe method of preserving food quality and ensuring its...
Thompson, Britta; Vestal, Andy; Van Laanen, Peggy
A Novel Computational Model for Tilting Pad Journal Bearings with Soft Pivot Stiffnesses
A novel tilting pad journal bearing model including pivot flexibility as well as temporal fluid inertia effects on the thin film fluid flow aims to accurately predict the bearing forced performance. The predictive model also accounts for the thermal...
Tao, Yujiao 1988-
Rotordynamic and thermal analyses of compliant flexure pivot tilting pad gas bearings
-free micro turbomachinery. The pad radial compliance was for accommodation of large rotor growth at high speeds. Parametric studies on pivot offset, preload, and tilting stiffness were performed using non-linear orbit simulations and coast-down simulations...
Sim, Kyu-Ho
Measurements of static loading characteristics of a Flexurepivot Tilt Pad Hydrodynamic Bearing
An experimental investigation examining the static loading characteristics of a four-pad, KMC FLEXUREPIVOT Tilt Pad Hydrodynamic Bearing is presented. Tests are conducted on the TRACE Fluid Film Bearing Element Test Rig for journal speeds ranging...
Walton, Nicholas Van Edward
Construction techniques and costs of tilt-up concrete farm structures
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 25 2S Ths warehouse with all Panels . 'honed and ths Pilaster Focal in Place Awaiting the Costing of ths Pilastars. . . . 29 14. Detail of Corner Pilaster~ Pilaster Fora, snd Footing Used in ths Concrete Tilt-Up w'arehouse . ~ . . ~ ~. . . . . 30... ~ ~ ~ ~ ~ ~ ~ 46 26. Detail of Zaproesd Corner Pilaster, Pilaster Rora, and Footing Used in the Concrete Tilt4p Anginal Shelter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 48 27. The Antnal shelter heady for (hating the ConcNts Posts and PDa sts...
Winsett, Ivan Lane
Inspired Design The slim, light Latitude 6430u is simply beautiful from every
laptops ever. All systems are BFR/PVC- free2 , EPEAT registered3 , ENERGY STAR 5.2 qualified and offer of Latitude E-family laptops, the Latitude 6430u is amongst the most environmentally- responsible Latitude. Available with a 14.0" HD or 14.0" HD+ display4 and HDMI and VGA ports, it enables versatile usage
Fiebig, Peter
? latitude. Near 30? latitude, the maximum oceanic response to sea breeze moves offshore slowly because of the near-zero group speed of Poincare waves at this latitude. The lateral energy flux convergence plus the energy input from the wind is maximum near...
Zhang, Xiaoqian
We study the Faraday rotation measure (RM) due to the Galactic magnetic field (GMF) toward high Galactic latitudes. The RM arises from the global, regular component as well as from the turbulent, random component of the GMF. We model the former based on observations and the latter using the data of magnetohydrodynamic turbulence simulations. For a large number of different GMF models, we produce mock RM maps around the Galactic poles and calculate various statistical quantities with the RM maps. We find that the observed medians of RMs toward the north and south Galactic poles, {approx}0.0 {+-} 0.5 rad m{sup -2} and {approx} + 6.3 {+-} 0.5 rad m{sup -2}, are difficult to explain with any of our many alternate GMF models. The standard deviation of observed RMs, {approx}9 rad m{sup -2}, is clearly larger than that of simulated RMs. The second-order structure function of observed RMs is substantially larger than that of simulated RMs, especially at small angular scales. We discuss other possible contributions to RM toward high Galactic latitudes. Besides observational errors and the intrinsic RM of background radio sources against which RM is observed, we suggest that the RM due to the intergalactic magnetic field may account for a substantial fraction of the observed RM. Finally, we note that reproducing the observed medians may require additional components or/and structures of the GMF that are not present in our models.
Akahori, Takuya; Kim, Jongsoo [Korea Astronomy and Space Science Institute, Daedeokdaero 776, Yuseong-Gu, Daejeon 305-348 (Korea, Republic of); Ryu, Dongsu [Department of Astronomy and Space Science, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Gaensler, B. M., E-mail: firstname.lastname@example.com, E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: email@example.com [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia)
Design and initial characterization of a compact, ultra high vacuum compatible, low frequency, tilt accelerometer
A compact tilt accelerometer with high sensitivity at low frequency was designed to provide low frequency corrections for the feedback signal of the Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge designed to avoid the mechanical 1/f noise believed to be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition and control limitations are discussed. The instrument's characterization reported here shows that the hinge is compatible with being metal-hysteresis-free, and therefore also free of the 1/f noise generated by the dislocation Self-Organized Criticality in the metal. A tiltmeter of this kind will be effective to separate the ground tilt component from the signal of horizontal low frequency seismometers, and to correct the ill effects of microseismic tilt in advanced seismic attenuation systems.
O�Toole, A., E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States); Pe�a Arellano, F. E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Rodionov, A. V.; Kim, C. [California Institute of Technology, Pasadena, California 91125 (United States); Shaner, M.; Asadoor, M. [Mayfield Senior School, 500 Bellefontaine Street Pasadena, California 91105 (United States); Sobacchi, E. [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Dergachev, V.; DeSalvo, R., E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); Bhawal, A. [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States); Gong, P. [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China); Lottarini, A. [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Minenkov, Y. [Sezione INFN Tor Vergata, via della Ricerca Scientfica 1, 00133 Roma (Italy); Murphy, C. [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia)
Blue-tilted Tensor Spectrum and Thermal History of the Universe
We investigate constraints on the spectral index of primordial gravitational waves (GWs), paying particular attention to a blue-tilted spectrum. Such constraints can be used to test a certain class of models of the early Universe. We investigate observational bounds from LIGO+Virgo, pulsar timing and big bang nucleosynthesis, taking into account the suppression of the amplitude at high frequencies due to reheating after inflation and also late-time entropy production. Constraints on the spectral index are presented by changing values of parameters such as reheating temperatures and the amount of entropy produced at late time. We also consider constraints under the general modeling approach which can approximately describe various scenarios of the early Universe. We show that the constraints on the blue spectral tilt strongly depend on the underlying assumption and, in some cases, a highly blue-tilted spectrum can still be allowed.
Sachiko Kuroyanagi; Tomo Takahashi; Shuichiro Yokoyama
No evidence for the blue-tilted power spectrum of relic gravitational waves
In this paper, we constrain the tilt of the power spectrum of relic gravitational waves by combining the data from BICEP2/Keck array and Planck (BKP) and the Laser Interferometer Gravitational-Waves Observatory (LIGO). From the data of BKP B-modes, the constraint on the tensor tilt is $n_t=0.66^{+1.83}_{-1.44}$ at the $68%$ confidence level. By further adding the LIGO upper limit on the energy density of gravitational waves, the constraint becomes $n_t=-0.76^{+1.37}_{-0.52}$ at the $68%$ confidence level. We conclude that there is no evidence for a blue-tilted power spectrum of relic gravitational waves and either sign of the index of tensor power spectrum is compatible with the data.
Huang, Qing-Guo
Qing-Guo Huang; Sai Wang
E-Print Network 3.0 - archipelago latitude 50degree20primes Sample...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
(Fig. 1). These islands ranged across 6 of latitude, five orders... archipelagoes (Lake Erie, St Lawrence, Georgian Bay, Apostle) in the Laurentian Great Lakes of North...
Resolution limits and process latitude of comformable contact nano-lithography
Conformable Contact Lithography enables researchers to attain high-resolution lithographic patterning at manageable cost. This thesis characterizes the minimum resolvable feature size and process latitude of Conformable ...
Fucetola, Corey Patrick
PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan1
PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan1 , Ilya Tsvankin2 , Mike Batzle3 , Kasper van Wijk4 , and Matthew Haney5 ABSTRACT Mode-converted PS-waves can- and PS- waves can be inverted for the parameters of a horizontal TI layer with a tilted symmetry axis
Tilted Micro Air Jet for Flow Control Julien Malapert*, Rda Yahiaoui, Rabah Zeggari and Jean-Franois Manceau
Tilted Micro Air Jet for Flow Control Julien Malapert*, Réda Yahiaoui°, Rabah Zeggari and Jean: In this paper, we present an interesting method to microfabricate a tilted micro air jet generator. We used a double side etching. For aircraft and cars, micro air jets will take an important place for fluid control
First Flight Tests for a Quadrotor UAV with Tilting Propellers Markus Ryll, Heinrich H. Bulthoff, and Paolo Robuffo Giordano
]. For these latter platforms, only the Cartesian position and yaw angle of their body frame w.r.t. an inertial frame directions. As quadrotor UAVs are being more and more exploited as autonomous flying service robots [3], [4: ducted-fan designs [5], tilt-wing mechanisms [6], [7], or tilt-rotor actuations [8], [9]. Along similar
Volume 177, number 2 CHEMICAL PHYSICS LETTERS 15 February 1991 Cu titration of tilted CO on a MO( 110) surface
to the surface normal. Upon subsequent deposition of = 0.9 ML Cu at 95 Kfollowed by heating, infrared, in a weakening of the C-O bond [ l-41. The tilted CO can either dissociate into atomic C and 0 upon heating to z) surface. In this Letter, we present the results of studies on tilted CO on MO( 110) using infrared
Goodman, Wayne
Roughness of a tilted anharmonic string at depinning T. Goodman1
a string with a net average tilt, we demonstrate that the anhar- monic elastic energy crosses the model renormalization group calculation by Le Doussal and Wiese [8] argued that the quenched KPZ term can indeed with zero average and unit vari- ance, f is a uniform external driving force, and Eel is the elastic energy
Teitel, Stephen L.
Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers
Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers M simultaneously caracterize precursors on the free surface with an optical method and in the bulk with acoustic to probe rearrangements in the bulk of the granular material. A linear method can also be used provided
Atomistic simulations of structures and mechanical properties of polycrystalline diamond: Symmetrical S001< tilt grain boundaries
Atomistic simulations of structures and mechanical properties of polycrystalline diamond for diamond to deposit as a polycrystalline film with a high density of grain boundaries and related defects structures and energies of symmetrical 001 tilt grain boundaries GB's in diamond have been calculated over
Brenner, Donald W.
Tilt Aftereffects in a Self-Organizing Model of the Primary Visual Cortex
RF-LISSOM, a self-organizing model of laterally connected orientation maps in the primary visual cortex, was used to study the psychological phenomenon known as the tilt aftereffect. The same self-organizing processes that are responsible for the long-term development of the map are shown to result in tilt aftereffects over short time scales in the adult. The model permits simultaneous observation of large numbers of neurons and connections, making it possible to relate high-level phenomena to low-level events, which is difficult to do experimentally. The results give detailed computational support for the long-standing conjecture that the direct tilt aftereffect arises from adaptive lateral interactions between feature detectors. They also make a new prediction that the indirect effect results from the normalization of synaptic efficacies during this process. The model thus provides a unified computational explanation of self-organization and both the direct and indirect tilt aftereffect in the primary visual cortex.
Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting
Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting Sissi de preferred solvent, leading to low friction and low wear rates. Here, we demonstrate, using molecular systems also show smaller friction than miscible systems, although the friction reduction is less than
Mueser, Martin
TILTED LAYER-BASED MODELING FOR ENHANCED LIGHT-FIELD PROCESSING AND IMAGE BASED RENDERING James, UK {j.pearson09, marcovs, mike.brookes, email@example.com ABSTRACT Image based rendering- torealistic results. However for successful rendering, geometric pri- ors about the structure of the scene
Dragotti, Pier Luigi
Selection of a numerical unsaturated flow code for tilted capillary barrier performance evaluation
Capillary barriers consisting of tilted fine-over-coarse layers have been suggested as landfill covers as a means to divert water infiltration away from sensitive underground regions under unsaturated flow conditions, especially for arid and semi-arid regions. Typically, the HELP code is used to evaluate landfill cover performance and design. Unfortunately, due to its simplified treatment of unsaturated flow and its essentially one-dimensional nature, HELP is not adequate to treat the complex multidimensional unsaturated flow processes occurring in a tilted capillary barrier. In order to develop the necessary mechanistic code for the performance evaluation of tilted capillary barriers, an efficient and comprehensive unsaturated flow code needs to be selected for further use and modification. The present study evaluates a number of candidate mechanistic unsaturated flow codes for application to tilted capillary barriers. Factors considered included unsaturated flow modeling, inclusion of evapotranspiration, nodalization flexibility, ease of modification, and numerical efficiency. A number of unsaturated flow codes are available for use with different features and assumptions. The codes chosen for this evaluation are TOUGH2, FEHM, and SWMS{_}2D. All three codes chosen for this evaluation successfully simulated the capillary barrier problem chosen for the code comparison, although FEHM used a reduced grid. The numerical results are a strong function of the numerical weighting scheme. For the same weighting scheme, similar results were obtained from the various codes. Based on the CPU time of the various codes and the code capabilities, the TOUGH2 code has been selected as the appropriate code for tilted capillary barrier performance evaluation, possibly in conjunction with the infiltration, runoff, and evapotranspiration models of HELP. 44 refs.
Webb, S.W. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.
The Structure of the Homunculus: I. Shape and Latitude Dependence from H2 and [Fe II] Velocity Maps of Eta Carinae
High resolution long-slit spectra obtained with the Phoenix spectrograph on Gemini South provide our most accurate probe of the three dimensional structure of the Homunculus around eta Car. The new near-infrared spectra dramatically confirm the double-shell structure inferred previously from thermal dust emission, resolving the nebula into a very thin outer shell seen in H2 21218, and a warmer, thicker inner layer seen in [Fe II] 16435. The thin H2 skin hints that the most important mass loss during the 19th century eruption had a very short duration of less than 5 yr. H2 emission traces the majority of the mass in the nebula, and has an average density of order 10^6.5 cm-3. This emission, in turn, yields our first definitive picture of the exact shape of the nebula, plus a distance of 2350pm50 pc and an inclination angle of 41deg (the polar axis is tilted 49deg from the plane of the sky). The distribution of the H2 emission provides the first measure of the latitude dependence of the speed, mass loss, and kinetic energy associated with eta Car's 19th century explosion. Almost 75 percent of the total mass and more than 90 percent of the kinetic energy in the ejecta were released at high latitudes. This rules out a model for the bipolar shape wherein an otherwise spherical explosion was pinched at the waist by a circumstellar torus. Also, the ejecta could not have been deflected toward polar trajectories by a companion star, since the kinetic energy of the polar ejecta is greater than the binding energy of the putative binary system. Instead, most of the mass appears to have been directed poleward by the explosion itself. [abridged
Nathan Smith
Beta diversity and latitude in North American mammals: testing the hypothesis of covariation
Beta diversity and latitude in North American mammals: testing the hypothesis of covariation Pilar Rodri´guez and He´ctor T. Arita Rodri´guez, P. and Arita, H. T. 2004. Beta diversity and latitude of the pattern remain insufficiently explored, including the effect of scales and the role of beta diversity
Nacional Autónoma de México, Universidad
latitude 2100 What if you could get fast internet access to check emails on the
the same· image commonality as the rest of your corporate notebooks? discover smart Functionality Smart, with Linux® or Microsoft® options. You can also make your laptop an extension of your business brand of the Latitude family, giving you the power to take advantage of our Latitude commitment to manageability, image
Properties of localized, high latitude, dayside aurora H. U. Frey,1
Properties of localized, high latitude, dayside aurora H. U. Frey,1 T. J. Immel,1 G. Lu,2 J different type of high latitude aurora, which does not show any signature of precipitating protons. It also causes the aurora. We interpret this aurora as the optical signature of electron precipitation
California at Berkeley, University of
Extended scaling factors for in situ cosmogenic nuclides: New measurements at low latitude
Extended scaling factors for in situ cosmogenic nuclides: New measurements at low latitude Darin by the intensity of energetic cosmic-ray nucleons, which changes rapidly with elevation. An incomplete knowledge, and that there has been an incomplete mapping of nucleon fluxes at high RC (low geomagnetic latitude). We report new
Zreda, Marek
Design and construction of a novel quad tilt-wing UAV E. Cetinsoy, S. Dikyar, C. Hancer, K.T. Oner, E. Sirimoglu, M. Unel
Design and construction of a novel quad tilt-wing UAV E. Cetinsoy, S. Dikyar, C. Hancer, K.T. Oner 12 March 2012 Available online xxxx Keywords: UAV Quad tilt-wing Aerodynamic design Carbon composite VehIcle). SUAVI is an electric powered quad tilt-wing UAV that is capable of vertical takeoff
�?�?nel, Mustafa
Molecular Simulation of Fracture Dynamics of Symmetric Tilt Grain Boundaries in Graphene
Atomistic simulations were utilized to obtain microscopic information of the elongation process in graphene sheets consisting of various embedded symmetric tilt grain boundaries (GBs). In contrast to pristine graphene, these GBs fractured in an extraordinary pattern under transverse uniaxial elongation in all but the largest misorientation angle case, which exhibited intermittent crack propagation and formed many stringy residual connections after quasi mechanical failure. The strings known as monoatomic carbon chains (MACCs), whose importance was recently highlighted, gradually extended to a maximum of a few nanometers as the elongation proceeded. These features, which critically affect the tensile stress and the shape of stress-strain curve, were observed in both armchair and zigzag-oriented symmetric tilt GBs. However, there exist remarkable differences in the population density and the achievable length of MACCs appearing after quasi mechanical failure which were higher in the zigzag-oriented GBs. In addi...
Jhon, Young In; Smith, Robert; Jhon, Myung S
An Analysis of Source Tilting and Sub-cell Opacity Sampling for IMC
Implicit Monte Carlo (IMC) is a stochastic method for solving the radiative transfer equations for multiphysics application with the material in local thermodynamic equilibrium. The IMC method employs a fictitious scattering term that is computed from an implicit discretization of the material temperature equation. Unfortunately, the original histogram representation of the temperature and opacity with respect to the spatial domain leads to nonphysically fast propagation of radiation waves through optically thick material. In the past, heuristic source tilting schemes have been used to mitigate the numerical teleportation error of the radiation particles in IMC that cause this overly rapid radiation wave propagation. While improving the material temperature profile throughout the time duration, these tilting schemes alone do not generally alleviate the teleportation error to suitable levels. Another means of potentially reducing teleportation error in IMC is implementing continuous sub-cell opacities based on sub-cell temperature profiles. We present here an analysis of source tilting and continuous sub-cell opacity sampling applied to various discretizations of the temperature equation. Through this analysis, we demonstrate that applying both heuristics does not necessarily yield more accurate results if the discretization of the material equation is inconsistent with the Monte Carlo sub-cell transport.
Wollaeger, Ryan T. [Los Alamos National Laboratory; Urbatsch, Todd J. [Los Alamos National Laboratory; Wollaber, Allan B. [Los Alamos National Laboratory; Densmore, Jeffery D. [Los Alamos National Laboratory
Red and blue tilted tensor spectrum from Gibbons-Hawking temperature
The scale invariant scalar and tensor perturbations, which are predicted from inflation, are eigenmodes in the conformal coordinates. The 'out' observer in the de Sitter space observes a thermal spectrum with a Gibbons-Hawking temperature $H/2\\pi$ of these 'Bunch-Davies' particles. The tensor power spectrum observed in experiments can have an imprint of the Gibbons-Hawking thermal distribution due to the mode mixing between 'in' state conformal coordinates and the coordinate frame of the observer. We find that the the Bunch-Davies modes appear as thermal modes to the asymptotic Minkowski observer in the future and the power spectrum of the gravitational waves is blue-tilted with a spectral index $n_T \\sim 1$ even in the standard slow-roll inflation. On the other hand if the coordinate frame of the observer is taken to be static coordinates, the tensor spectrum is red-tilted with $n_T\\sim -1$. A likelihood analysis shows and find the best fit values of the slow-roll parameters for both cases. We find that the blue-tilted tensor gives a better fit and reconciles the PLANCK upper bound on the tensor-to-scalar ratio, $r <0.11$ with BICEP2 measurement of $r=0.2$. This supports the idea of particle production due to the mode mixing between the initial Bunch-Davies vacuum modes and the asymptotic Minkowski vacuum of the post-inflation universe.
Subhendra Mohanty; Akhilesh Nautiyal
Measured and Predicted Rotor-Pad Transfer Functions for a Rocker-Pivot Tilting-Pad Journal Bearing
Many researchers have compared predicted stiffness and damping coefficients for tilting-pad journal bearings (TPJBs) to measurements. Most have found that direct damping is consistently overpredicted. The thrust of this research is to explain...
Wilkes, Jason Christopher
Investigation of failed fuel detection and location using a flux tilting method in a fast breeder reactor
Detection and location of failed fuel in a liquid-metal fast breeder reactor (LMFBR) are very important both for safety and availability. When a fuel failure is detected, it is desirable to identify the failed subassembly quickly to reduce plant shutdown time. The flux tilting method is expected to effectively identify the defective subassembly. The feasibility of the flux tilting method is investigated for an LMFBR with a 100-MW (electric) homogeneous core. A numerical simulation is performed to estimate the viability of the flux tilting method, and a combination of the flux tilting method and the sipping method is found to be very effective in identifying the failed subassembly. In this paper a functional scheme for a computer-aided failed fuel detection and location system is discussed as part of a future on-line support system.
Hamada, M.; Uehara, K.; Muramatsu, K. (Japan Atomic Power Co., 1-6-1 Otemachi, Chiyoda-ku, Tokyo 100 (JP)); Kamei, T.; Tamaoki, T.; Yamaoka, M.; Sonada, Y.; Sano, Y. (Toshiba Corp., Nuclear Engineering Lab., 4-1 Ukishima-cho, Kawasaki-ku, Kawasaki 210 (JP))
Comminuting irradiated ferritic steel
Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.
Bauer, Roger E. (Kennewick, WA); Straalsund, Jerry L. (Kennewick, WA); Chin, Bryan A. (Auburn, AL)
Irradiation Creep in Graphite
An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.
Ubic, Rick; Butt, Darryl; Windes, William
Diffuse Galactic Light in the Field of the Translucent High Galactic Latitude Cloud MBM32
We have conducted B, g, V, and R-band imaging in a 45x40 arcmin^2 field containing part of the high Galactic latitude translucent cloud MBM32, and correlated the intensity of diffuse optical light S_\
Ienaka, N; Matsuoka, Y; Sameshima, H; Oyabu, S; Tsujimoto, T; Peterson, B A
Dual-frequency terahertz emission from splitting filaments induced by lens tilting in air
Dual-frequency terahertz radiation from air-plasma filaments produced with two-color lasers in air has been demonstrated experimentally. When a focusing lens is tilted for a few degrees, it is shown that the laser filament evolves from a single one to two sub-filaments. Two independent terahertz sources emitted from the sub-filaments with different frequencies and polarizations are identified, where the frequency of terahertz waves from the trailing sub-filament is higher than that from the leading sub-filament.
Zhang, Zhelin; Chen, Yanping, E-mail: firstname.lastname@example.com; Yang, Liu; Yuan, Xiaohui; Liu, Feng; Chen, Min; Xu, Jianqiu; Zhang, Jie [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Sheng, Zhengming [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)
An experimental investigation of a tilt rotor aircraft wake in ground effect
: Sktlld dS t' 1, "~Et 18, 6 (1975), pp. 51-673. Hunt, J. C. R. , Poulton, E. C. , and Mumford, J. C. , "The Effects of Wldppl:Sd't*l Bd tldt lt*p*' t, "~Bi1di Environment, 11 (1976), pp. 15-28. 50 VITA gichael Louis Frey III was born January 4, 1957...EXPERIMENTAL INVESTIGATION OF A TILT ROTOR AIRCRAFT WAKE IN GROUND EFFECT A Thesis by MICHAEL LOUIS FREY III Submi. tted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER...
Frey, Michael Louis
Ferroelectric and octahedral tilt twin disorder and the lead-free piezoelectric, sodium potassium niobate system
Using electron diffraction, trends in the local structural behaviour of the K{sub x}Na{sub 1-x}NbO{sub 3} (KNN x) 'solid solution' system are investigated and interpreted using an order/disorder based theoretical framework. At room temperature, electron diffraction shows a single plane of transverse polarised, diffuse intensity perpendicular to [0 1 0]{sub p} Low-Asterisk (p for parent sub-structure) across the entire phase diagram, indicative of ferroelectric disorder along the [0 1 0]{sub p} direction co-existing with long range ferroelectric order along the orthogonal [1 0 0]{sub p} and [0 0 1]{sub p} directions. An additional characteristic pattern of diffuse scattering is also observed, involving rods of diffuse intensity running along the [1 0 0]{sub p}* and [0 0 1]{sub p}* directions of the perovskite sub-structure and indicative of octahedral tilt disorder about the [1 0 0]{sub p} and [0 0 1]{sub p} axes co-existing with long range ordered octahedral tilting around the [0 1 0]{sub p} direction. A possible crystal chemical explanation for the existence of this latter octahedral tilt disorder is explored through bond valence sum calculations. The possible influence of both types of disorder on the previously refined, room temperature space group/s and average crystal structure/s is examined. - Graphical abstract: [-3,0.-1]p zone axis EDP of K{sub 0.46}Na{sub 0.54}NbO{sub 3} indexed according to both the relevant Pcm21 space groups (no subscripts) and the parent perovskite subcell (denoted by a subscript p). Highlights: Black-Right-Pointing-Pointer Characterises ferroelectric and octahedral tilt disorder in the KNN solid solution. Black-Right-Pointing-Pointer Discusses the possible driving forces for this disorder. Black-Right-Pointing-Pointer Discusses the implications of this disorder for physical properties. Black-Right-Pointing-Pointer Discusses the effects of this disorder on powder diffraction data.
Schiemer, Jason [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)] [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia); Withers, Ray L., E-mail: email@example.com [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia); Liu, Yun; Yi, Zhiguo [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)] [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)
FLASH seminar -14/01/08 Eduard Prat, DESY Beam tilt studies at FLASH
generated different vertical bumps at BPM9ACC1. For each bump we measured: -Dispersion from ACC1 -Beam tilt.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 V1GUN (23-10-07) #BPM Orbitresponse[mm/mrad] 1mrad model 0 2 4 6 8 10 12 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 V3GUN (23-10-07) #BPM Orbitresponse[mm/mrad] 1mrad model 0 2 4 6
Accurate measurement of relative tilt and azimuth angles in electron tomography: A comparison of fiducial marker method with electron diffraction
Electron tomography is a method whereby a three-dimensional reconstruction of a nanoscale object is obtained from a series of projected images measured in a transmission electron microscope. We developed an electron-diffraction method to measure the tilt and azimuth angles, with Kikuchi lines used to align a series of diffraction patterns obtained with each image of the tilt series. Since it is based on electron diffraction, the method is not affected by sample drift and is not sensitive to sample thickness, whereas tilt angle measurement and alignment using fiducial-marker methods are affected by both sample drift and thickness. The accuracy of the diffraction method benefits reconstructions with a large number of voxels, where both high spatial resolution and a large field of view are desired. The diffraction method allows both the tilt and azimuth angle to be measured, while fiducial marker methods typically treat the tilt and azimuth angle as an unknown parameter. The diffraction method can be also used to estimate the accuracy of the fiducial marker method, and the sample-stage accuracy. A nano-dot fiducial marker measurement differs from a diffraction measurement by no more than �1�.
Hayashida, Misa [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Malac, Marek; Egerton, Ray F. [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton T6G 2M9 (Canada); Department of Physics, University of Alberta, Edmonton T6H 2E1 (Canada); Bergen, Michael; Li, Peng [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton T6G 2M9 (Canada)
Early structure formation from primordial density fluctuations with a blue-tilted power spectrum
While observations of large-scale structure and the cosmic microwave background (CMB) provide strong constraints on the amplitude of the primordial power spectrum (PPS) on scales larger than 10 Mpc, the amplitude of the power spectrum on sub-galactic length scales is much more poorly constrained. We study early structure formation in a cosmological model with a blue-tilted PPS. We assume that the standard scale-invariant PPS is modified at small length scales as $P(k) \\sim k^{m_{\\rm s}}$ with $m_{\\rm s} > 1$. We run a series of cosmological hydrodynamic simulations to examine the dependence of the formation epoch and the characteristic mass of primordial stars on the tilt of the PPS. In models with $m_{\\rm s} > 1$, star-forming gas clouds are formed at $z > 100$, when formation of hydrogen molecules is inefficient because the intense CMB radiation destroys chemical intermediates. Without efficient coolant, the gas clouds gravitationally contract while keeping a high temperature. The protostars formed in such ...
Hirano, Shingo; Yoshida, Naoki; Spergel, David; Yorke, Harold W
Direct injection of ionospheric O sup + into the dayside low latitude boundary layer
Observations from the AMPTE/Charge Composition Explorer (AMPTE/CCE) indicate the presence of two distinct O{sup +} populations in the dayside subsolar low latitude boundary layer during some periods of northward Interplanetary Magnetic Field (IMF). The first population is O{sup +} convected into the boundary layer from the outer magnetosphere and has been reported previously. It is suggested here that the new, second, O{sup +} population is injected into the dayside boundary layer directly from the high latitude ionosphere. This second population can have a significant density and distinct characteristics such as field-aligned flow relative to boundary layer H{sup +} that modify both the plasma composition and dynamics in the low latitude boundary layer. {copyright} American Geophysical Union 1989
Fuselier, S.A.; Klumpar, D.M.; Peterson, W.K.; Shelley, E.G. (Lockheed Palo Alto Research Laboratory, Palo Alto, California (US))
Mechanical and charge transport properties of alkanethiol self-assembled monolayers on Au (111) surface: The Role of Molecular Tilt
The relationship between charge transport and mechanical properties of alkanethiol self-assembled monolayers (SAM) on Au(111) films has been investigated using an atomic force microscope with a conductive tip. Molecular tilts induced by the pressure applied by the tip cause stepwise increases in film conductivity. A decay constant {beta} = 0.57 {+-} 0.03 {angstrom}{sup -1} was found for the current passing through the film as a function of tip-substrate separation due to this molecular tilt. This is significantly smaller than the value of {approx} 1 {angstrom}{sup -1} found when the separation is changed by changing the length of the alkanethiol molecules. Calculations indicate that for isolated dithiol molecules S-bonded to hollow sites, the junction conductance does not vary significantly as a function of molecular tilt. The impact of S-Au bonding on SAM conductance is discussed.
Mulleregan, Alice; Qi, Yabing; Ratera, Imma; Park, Jeong Y.; Ashby, Paul D.; Quek, Su Ying; Neaton, J. B.; Salmeron, Miquel
A study of mid-latitude tropopause characteristics over eastern North America
- parable latitudes in other parts of the worldf Some correlation 34 0. 7 4J n e W W c 0 al w n 0 0. 6 0. 5 0. 4 0. 3 0. 2 0. 1 BUF PIT Gg0 C@S 60 55 50 45 40 35 Latitude (degrees north) Figure 7. Average of the absolute values... tropopauses during summer 2. Profile of mean zonal wind during summer 3. Occurrence of multiple tropopauses during winter 4. Profile of mean zonal wind during winter 20 21 5. Mean and standard deviation of primary tropopause height during summer 25 6...
Houston, Ben Howard
High-power, low-lateral divergence broad area quantum cascade lasers with a tilted front facet
We introduce a simple technique to improve the beam quality of broad area quantum cascade lasers. Moderately tilted front facets of the laser provide suppression of higher order lateral waveguide modes. A device with a width of 60??m and a front facet angle of 17� shows a nearly diffraction limited beam profile. In addition, the peak output power and the slope efficiency of the device are increased since most of the light inside the cavity is emitted through the tilted front facet by an asymmetric light intensity distribution along the cavity.
Ahn, Sangil, E-mail: email@example.com; Schwarzer, Clemens; Zederbauer, Tobias; MacFarland, Donald C.; Detz, Hermann; Andrews, Aaron M.; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics, Vienna University of Technology, 1040 Vienna (Austria)
Irradiation Stability of Carbon Nanotubes
Ion irradiation of carbon nanotubes is a tool that can be used to achieve modification of the structure. Irradiation stability of carbon nanotubes was studied by ion and electron bombardment of the samples. Different ion species at various energies...
Aitkaliyeva, Assel
Some unusual discrete VLF emissions observed at a low-latitude ground station at Agra
Some unusual discrete VLF emissions observed at a low-latitude ground station at Agra B. Singh February 1997 / Accepted: 17 February 1997 Abstract. A detailed analysis of the VLF emissions data obtained°1¢ N, L = 1.15) has yielded some unusual discrete VLF emissions of the rising type. These include (1
Role of latitude of source region in Solar Energetic Particle events
PR1 2HE, UK Department of Physics, University of Helsinki, 00014 Helsinki, Finland Abstract. Solar up to near- relativistic energies. Some of these particles can escape the solar atmosphere and travelRole of latitude of source region in Solar Energetic Particle events S. Dalla and N. Agueda1
Sanahuja, Blai
We have completed a survey for pulsars at high Galactic latitudes with the 64 m Parkes radio telescope. Observing with the 13 beam multibeam receiver at a frequency of 1374 MHz, we covered {approx}4150 square degrees in the region -100 deg. {<=} l {<=} 50 deg., 15 deg. {<=} |b| {<=} 30 deg. with 7232 pointings of 265 s each, thus extending the Swinburne Intermediate Latitude Pulsar Survey a further 15 deg. on either side of the Galactic plane. The signal from each beam was processed by a 96 channel x 3 MHz x 2 polarization filterbank, with the detected power in the two polarizations of each frequency channel summed and digitized with 1 bit sampling every 125 {mu}s, giving good sensitivity to millisecond pulsars with low or moderate dispersion measure. The resulting 2.4 TB data set was processed using standard pulsar search techniques with the workstation cluster at the Swinburne Centre for Astrophysics and Supercomputing. This survey resulted in the discovery of 26 new pulsars including seven binary and/or millisecond pulsars, and redetected 36 previously known pulsars. We describe the survey methodology and results, and present timing solutions for the 19 newly discovered slow pulsars, as well as for nine slow pulsars discovered the Swinburne Intermediate Latitude Pulsar Survey that had no previous timing solutions. Even with a small sampling interval, 1374 MHz center frequency, and a large mid-latitude survey volume we failed to detect any very rapidly spinning pulsars. Evidently, such 'submillisecond' pulsars are rare.
Jacoby, B. A.; Kulkarni, S. R. [Department of Astronomy, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Bailes, M.; Ord, S. M. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 31122 (Australia); Edwards, R. T. [Australia Telescope National Facility, CSIRO, P.O. Box 76, Epping, NSW 1710 (Australia)], E-mail: firstname.lastname@example.com, E-mail: email@example.com, E-mail: email@example.com, E-mail: email@example.com, E-mail: email@example.com
Friction in Mid-latitude Bob Plant, Stephen Belcher, Bob Beare, Andy Brown
Friction in Mid-latitude Cyclones Ian Boutle Bob Plant, Stephen Belcher, Bob Beare, Andy Brown #12;Motivation · Many studies have shown the significance of friction in formation and dissipation of cyclones Dt = + �? . F . Diabatic Term: · Surface heat fluxes · Latent heat fluxes Frictional Term
Plant, Robert
THE ROTATION PROFILE OF SOLAR MAGNETIC FIELDS BETWEEN {+-}60 Degree-Sign LATITUDES
Through a cross-correlation analysis of the Carrington synoptic maps of solar photospheric magnetic fields from Carrington Rotation Nos. 1625 to 2129 (from 1975 February to 2012 October), the sidereal rotation rates of solar magnetic fields between {+-}60 Degree-Sign latitudes are investigated. It seems that the temporal variation of rotation rates should be related to the solar cycle phase. The rotation profile of magnetic fields is obtained: the sidereal rotation rates decrease from the equator to mid-latitude and reach their minimum values of about 13.16 deg day{sup -1} (13.17 deg day{sup -1}) at 53 Degree-Sign (54 Degree-Sign ) latitude in the northern (southern) hemisphere, then increase toward higher latitudes. This rotation profile is different from the differential rotation law obtained by Snodgrass from a cross-correlation analysis of daily magnetograms, in which the rotation rates show a steep decrease from the equator to the poles. However, it is much closer to the quasi-rigid rotation law derived by Stenflo from an auto-correlation analysis of daily magnetograms. Some possible interpretations are discussed for the resulting rotation profile.
Shi, X. J.; Xie, J. L., E-mail: email@example.com [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China)
Previous observations of Saturn's infrared aurorae have shown that a mid-latitude aurora exists significantly equatorward of the main auroral oval. Here, we present new results using data from four separate observing runs in 1998, 2003, 2008, and 2010. When combined, these provide a view of the mid-latitude aurora under a considerable range of viewing conditions, allowing the first calculation of the latitudinal position of this aurora to be made. This has shown that the mid-latitude aurora is located at the magnetic footprint of the region within the magnetosphere where the initial breakdown in corotation occurs, between 3 R {sub S} and the orbit of Enceladus ({approx}3.95 R {sub S}). We also confirm that this aurora is a continuous stable feature over a period of more than a decade and that an oval morphology is likely. When combined, these results indicate that the mid-latitude auroral oval is formed by currents driven by the breakdown process within the magnetosphere, in turn caused by mass loading from the torus of Enceladus, analogous with the volcanic moon Io's dominant role in the formation of Jupiter's main auroral oval.
Stallard, Tom; Melin, Henrik; Cowley, Stanley W. H. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Miller, Steve [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Lystrup, Makenzie B., E-mail: firstname.lastname@example.com [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, CO 80303-7814 (United States)
Discovery of Eight Recycled Pulsars - The Swinburne Intermediate Latitude Pulsar Survey
We have conducted a pulsar survey of intermediate Galactic latitudes (15deg 0.57 Mo and > 1.2 Mo), while anotherhas a low mass (~0.2 Mo) companion in a 23.3-d orbit, residing the well-known orbital period ``gap''.
R. T. Edwards
High-latitude eruptions cast shadow over the African monsoon and the flow of the Nile
the Sahel of Africa, thus producing the low Nile flow. Future high-latitude eruptions would significantly, p. 120]. By January 1785, 1/6 of the population of Egypt had either died or left the country of Asia and North America. Recon- structed summer temperatures using tree ring maximum latewood density
Stenchikov, Georgiy L.
Polarization-resolved sensing with tilted fiber Bragg gratings: theory and limits of detection
Polarization based sensing with tilted fiber Bragg grating (TFBG) sensors is analysed theoretically by two alternative approaches. The first method is based on tracking the grating transmission for two orthogonal states of linear polarized light that are extracted from the measured Jones matrix or Stokes vectors of the TFBG transmission spectra. The second method is based on the measurements along the system principle axes and polarization dependent loss (PDL) parameter, also calculated from measured data. It is shown that the frequent crossing of the Jones matrix eigenvalues as a function of wavelength leads to a non-physical interchange of the calculated principal axes; a method to remove this unwanted mathematical artefact and to restore the order of the system eigenvalues and the corresponding principal axes is provided. A comparison of the two approaches reveals that the PDL method provides a smaller standard deviation and therefore lower limit of detection in refractometric sensing. Furthermore, the pol...
Bialiayeu, Aliaksandr; Albert, Jacques
Atomic structure of the {sigma}5 (210)/[001] symmetric tilt grain boundary in yttrium aluminum garnet
The {Sigma}5(210)/[100] symmetric tilt grain boundary in YAG was produced by UHV diffusion bonding precisely oriented single crystals. The boundary has been characterized by HREM along two different directions, parallel and perpendicular to the tilt axis. Models of the atomic structure of the boundary were formed following the Coincident Site Lattice scheme. The resulting models are equivalent to twins formed at the atomic scale. The high resolution images show no rigid crystal translations away from the perfect mirror reflection relation. Comparison of the simulated images using the atomic model as input with the experimental images identifies the plane of mirror symmetry. The atomic model is shown to be in good agreement with the experimental images when viewed parallel to tilt axis, but disagrees with the images perpendicular to tilt axis. Agreement between simulated and experimental images can be improved by changing the composition of the grain boundary with respect to the bulk. To reach a more certain conclusion on the structure of the grain boundary will require additional theoretical calculations.
Campbell, G.H.; King, W.E.
Tilted Brownian Ratchet for DNA Analysis Lotien Richard Huang, Edward C. Cox, Robert H. Austin,*, and James C. Sturm
Tilted Brownian Ratchet for DNA Analysis Lotien Richard Huang, Edward C. Cox, Robert H. Austin of fractionation of 100-kb DNA molecules in Brownian ratchet arrays. In our device, the electrophoretic flow a higher fraction of the diffusing molecules is "ratcheted" at each step in the array. Molecules of lengths
Rotordynamic coefficients for a load-between-pad, flexible-pivot tilting pad bearing at high loads
The dynamic and static performance of a flexure-pivot tilting pad bearing is presented at a load between pad configuration for various load and speed combinations. A similar work performed on the same bearing at lower loads ranging from 0-1 MPa (0...
Hensley, John Eric
FlIGHT PATH FOLLOWING GUIDANCE FOR UNMANNED AIR VEHICLES WITH PAN-TILT CAMERA FOR TARGET OBSERVATION
Autonomous Vehicle (UAV) is equipped with a nose-mounted camera capable of pan and tilt rotation is affected by wind. Furthermore, the relative position of the sun can lead to glare and image overexposure. While the effect of wind can be improved by commanding a sideslip angle, image overexposure is avoided
Washington at Seattle, University of
Cone-beam mammo-computed tomography from data along two tilting arcs Hengyong Yu,b
Cone-beam mammo-computed tomography from data along two tilting arcs Kai Zeng,a Hengyong Yu . To address this problem, x-ray tomosynthesis and cone-beam computed tomography CT are two compelling from a limited num- ber of projections.4 Since its introduction in 1972, the area of tomosynthesis has
Virginia Tech
High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Mark Bourassa1
temperatures, seasonal sea ice, and the remoteness of the regions all conspire to make observations difficult latitudes - the vertical exchanges of heat, momentum and material between the ocean, atmosphere and ice1 High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Research
Gille, Sarah T.
High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 Mark A. Bourassa1
), and in 2008, the Wilkins Ice Shelf51 collapsed equally quickly (Scambos et al. 2009). Ocean heat content1 High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 2 Mark A-latitude surface fluxes will require close collaboration among meteorologists,33 oceanographers, ice physicists
Seasonal dependence of localized, high-latitude dayside aurora H. U. Frey, N. stgaard, and T. J. Immel
Seasonal dependence of localized, high-latitude dayside aurora (HiLDA) H. U. Frey, N. �stgaard frequently observes intense ultraviolet (UV) emissions from a localized High Latitude Dayside Aurora (HiLDA) poleward of the general auroral oval location [Frey et al., 2003a]. It has been shown that this aurora
Optical Design Considerations Relevant to Reflective UV Launch Gratings for Photocathode Irradiation
The characteristics of photoelectron microbunches emitted from a photocathode in response to laser irradiation determine many of the incident laser pulse requirements. RF photocathode designs based on grazing incidence of the irradiation benefit from the removal of launch optics from the electron beamline and enhanced absorption at Brewster angles. However, this also introduces two well known complexities in the laser pulse 'launch' requirements: (i) a transverse spatial anamorphism to guarantee that the projected transverse spatial profile of the irradiation is circular (in the plane of the photocathode) and (ii) a 'time slew' or tilted amplitude front on the laser pulse that is incident on the photocathode to guarantee that the temporal (longitudinal) profiles are synchronous across the entire transverse irradiation profile in the photocathode plane. A single diffraction grating can be used to fulfill these combined requirements. This reported work focuses on grating behavior only. It does not address imaging requirements associated with relayed optical transport from the grating to the photocathode. Because the grating is a highly dispersive optical element by design, the dispersive aspects of all launch requirements are important.
Bolton, Paul
Multi-Year Lags between Forest Browning and Soil Respiration at High Northern Latitudes
High-latitude northern ecosystems are experiencing rapid climate changes, and represent a large potential climate feedback because of their high soil carbon densities and shifting disturbance regimes. A significant carbon flow from these ecosystems is soil respiration (RS, the flow of carbon dioxide, generated by plant roots and soil fauna, from the soil surface to atmosphere), and any change in the high-latitude carbon cycle might thus be reflected in RS observed in the field. This study used two variants of a machine-learning algorithm and least squares regression to examine how remotely-sensed canopy greenness (NDVI), climate, and other variables are coupled to annual RS based on 105 observations from 64 circumpolar sites in a global database. The addition of NDVI roughly doubled model performance, with the best-performing models explaining ~62% of observed RS variability
Bond-Lamberty, Benjamin; Bunn, Andrew G.; Thomson, Allison M.
Impact of rising greenhouse gases on mid-latitude storm tracks and associated hydroclimate variability and change
Project Summary This project aimed to advance physical understanding of how and why the mid-latitude jet streams and storm tracks shift in intensity and latitude in response to changes in radiative forcing with an especial focus on rising greenhouse gases. The motivation, and much of the work, stemmed from the importance that these mean and transient atmospheric circulation systems have for hydroclimate. In particular drying and expansion of the subtropical dry zones has been related to a poleward shift of the mid-latitude jets and storm tracks. The work involved integrated assessment of observation and model projections as well as targeted model simulations.
Seager, Richard
Effects of head-up tilt on mean arterial pressure, heart rate, and regional cardiac output distribution in aging rats
Approved by: Chair of Committee, Michael Delp Committee Members, Robert Armstrong Judy Muller-Delp Janet r Head of Department, Steve M. Dorman December 2005 Major Subject: Kinesiology iii ABSTRACT Effects of Head-up Tilt... Armstrong, and Dr. Janet Parker for their patience, guidance, and support thoughout the course of this research. vi TABLE OF CONTENTS Page ABSTRACT????????????????????????.. iii ACKNOWLEDGEMENTS??????????????????.. v TABLE OF CONTENTS...
Ramsey, Michael Wiechmann
Static characteristics and rotordynamic coefficients of a four-pad tilting-pad journal bearing with ball-in-socket pivots in load-between-pad configuration
Static characteristics and rotordynamic coefficients were experimentally determined for a four-pad tilting-pad journal bearing with ball-in-socket pivots in loadbetween- pad configuration. A frequency-independent [M]-[C]-[K] model fit...
Harris, Joel Mark
Experimental frequency-dependent rotordynamic coefficients for a load-on-pad, high-speed, flexible-pivot tilting-pad bearing
This thesis provides experimental frequency dependent stiffness and damping coefficient results for a high-speed, lightly loaded, flexible-pivot tilting-pad bearing, with a load-on-pad configuration. Test conditions include four shaft speeds (6000...
Rodriguez Colmenares, Luis Emigdio
Uncertainty analysis of vegetation distribution in the northern high latitudes during the 21st century with a dynamic vegetation model
This study aims to assess how high-latitude vegetation may respond under various climate scenarios during the 21st century with a focus on analyzing model parameters induced uncertainty and how this uncertainty compares ...
Jiang, Yueyang
Simulations of dislocation pile-ups at assymetric tilt boundaries in aluminum
Materials deformation processes are increasingly approachable through the both conventional and accelerated molecular dynamics. In one deformation process, dislocation pile-up at a grain boundary, a greater understanding is required as to how dislocations transmit through grain boundaries, causing plastic deformation, or reflect and reconstruct the grain boundary, but with no macroscopic deformation. Here dislocation pile-ups in an alwninum bicrystal with an asymmetric tilt grain boundary are simulated atomistically, introducing effects of dislocation interactions beyond linear elastic ones. The observed responses as functions of the number of explicitly modeled dislocations and the magnitude of the applied stress are discussed. Typical conditions for the simulations consist of thermal relaxation room temperature, five active dislocations inserted within a 6.5-million-atom cell, and an additional fourteen dislocations represented within the atomistic simulation by their elastic strain fields. The dislocations are initially distributed according to linear elastic estimates of their positions in a double-ended pile-up from a chosen far-field stress. The whole cell is allowed to relax according to a procedure to be described. In the ensuing simulations, the system is propagated for some substantial period of time (lOs of ps), followed by small increments of strain. After a number of such increments, we observe all of the anticipated events. Usually several of the closest dislocations are absorbed into the grain boundary, resulting in varying amounts of reconstruction. Reflections from the boundary are common and show a strong dependence on sample thickness. Transmission events are seen on both slip systems in the other grain. The particulars of these events will be described as well.
Valone, Steven [Los Alamos National Laboratory; Wang, Jian M [Los Alamos National Laboratory; Hoagland, Richard C [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory
Identifying liquid water on the surface of planets is a high priority, as this traditionally defines habitability. One proposed signature of oceans is specular reflection ('glint'), which increases the apparent albedo of a planet at crescent phases. We post-process a global climate model of an Earth-like planet to simulate reflected light curves. Significantly, we obtain glint-like phase variations even though we do not include specular reflection in our model. This false positive is the product of two generic properties: (1) for modest obliquities, a planet's poles receive less orbit-averaged stellar flux than its equator, so the poles are more likely to be covered in highly reflective snow and ice; and (2) we show that reflected light from a modest-obliquity planet at crescent phases probes higher latitudes than at gibbous phases, therefore a planet's apparent albedo will naturally increase at crescent phase. We suggest that this 'latitude-albedo effect' will operate even for large obliquities: in that case the equator receives less orbit-averaged flux than the poles, and the equator is preferentially sampled at crescent phase. Using rotational and orbital color variations to map the surfaces of directly imaged planets and estimate their obliquity will therefore be a necessary pre-condition for properly interpreting their reflected phase variations. The latitude-albedo effect is a particularly convincing glint false positive for zero-obliquity planets, and such worlds are not amenable to latitudinal mapping. This effect severely limits the utility of specular reflection for detecting oceans on exoplanets.
Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States); Abbot, Dorian S. [Department of Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States); Voigt, Aiko [Max Planck Institute for Meteorology, Bundesstr. 53, D-20146, Hamburg (Germany)
Population Studies of Gamma Ray Sources Using Stacking Analysis at Low Galactic Latitudes
We studied the problem of the treatment of uncertainties in the diffuse gamma radiation apparent in stacking analysis of EGRET data at low Galactic latitudes for several classes of sources like PSRs. For those classes of sources we co-added maps of counts, exposure and diffuse background, and residuals, in varying numbers for different sub-categories. Finally we tested for gamma-ray excess emission in those maps and attempt to quantify the systematic biases in such approach. Such kinds of analysis will support and provide confidence in the classification processes of sources and source populations in the GLAST era.
Cillis, Analia N.; /NASA, Goddard; Reimer, Olaf; /Stanford U., HEPL /KIPAC, Menlo Park; Torres, Diego F.; /ICREA, Barcelona /Barcelona, Autonoma U.
Atick-Witten Hagedorn Conjecture, near scale-invariant matter and blue-tilted gravity power spectrum
We will provide an interesting new mechanism to generate almost scale invariant seed density perturbations with a red spectrum, while keeping the gravitational wave spectrum blue-tilted in a stringy thermal contracting phase at temperatures beyond the Hagedorn temperature. This phase is often referred to as the Hagedorn phase where the free energy has been conjectured by Atick and Witten to grow more slowly than ordinary radiation. The primordial fluctuations are created by the statistical thermal fluctuations determined by the partition function, rather than quantum vacuum driven fluid dynamical fluctuations. In order for our mechanism to work we require a non-singular bouncing cosmology.
Tirthabir Biswas; Tomi Koivisto; Anupam Mazumdar
Proton irradiation effect on SCDs
The Low Energy X-ray Telescope is a main payload on the Hard X-ray Modulation Telescope satellite. The swept charge device is selected for the Low Energy X-ray Telescope. As swept charge devices are sensitive to proton irradiation, irradiation test was carried out on the HI-13 accelerator at the China Institute of Atomic Energy. The beam energy was measured to be 10 MeV at the SCD. The proton fluence delivered to the SCD was $3\\times10^{8}\\mathrm{protons}/\\mathrm{cm}^{2}$ over two hours. It is concluded that the proton irradiation affects both the dark current and the charge transfer inefficiency of the SCD through comparing the performance both before and after the irradiation. The energy resolution of the proton-irradiated SCD is 212 email@example.com keV at $-60\\,^{\\circ}\\mathrm{C}$, while it before irradiated is 134 eV. Moreover, better performance can be reached by lowering the operating temperature of the SCD on orbit.
Yan-Ji Yang; Jing-Bin Lu; Yu-Sa Wang; Yong Chen; Yu-Peng Xu; Wei-Wei Cui; Wei Li; Zheng-Wei Li; Mao-Shun Li; Xiao-Yan Liu; Juan Wang; Da-Wei Han; Tian-Xiang Chen; Cheng-Kui Li; Jia Huo; Wei Hu; Yi Zhang; Bo Lu; Yue Zhu; Ke-Yan Ma; Di Wu; Yan Liu; Zi-Liang Zhang; Guo-He Yin; Yu Wang
MS 1603. 6 + 2600, an unusual X-ray selected binary system at high Galactic latitude
The discovery of an eclipsing binary system at Galactic latitude 47 deg, found as a serendipitous X-ray source in the Einstein Extended Medium Sensitivity Survey, is described. The object has X-ray flux 1.1 x 10 to the -12th ergs/sq cm s (0.3-3.5 keV) and mean magnitude R = 19.4. An orbital period of 111 minutes is found. The problem discussed is whether the system has a white dwarf or neutron star primary, in the end preferring the neutron star primary model. If the system has either optical or X-ray luminosities typical of low mass X-ray binaries (LMXB), it must be at a very large distance (30-80 kpc). Blueshifted He I absorption is seen, indicating cool outflowing material, similar to that seen in the LMXB AC 211 in the globular cluster M15. 29 refs.
Morris, S.L.; Liebert, J.; Stocke, J.T.; Gioia, I.M.; Schild, R.E. (Observatories of the Carnegie Institution, Pasadena, CA (USA) Colorado Univ., Boulder (USA) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA))
The Masses Of The B-Stars In The High Galactic Latitude Eclipsing Binary IT Lib
A number of blue stars which appear to be similar to Population I B-stars in the star forming regions of the galactic disk are found more than 1 kpc from the galactic plane. Uncertainties about the true distances and masses of these high latitude B-stars has fueled a debate as to their origin and evolutionary status. The eclipsing binary IT Lib is composed of two B-stars, is approximately one kiloparsec above the galactic plane, and is moving back toward the plane. Observations of the light and velocity curves presented here lead to the conclusion that the B-stars in this system are massive young main-sequence stars. While there are several possible explanations, it appears most plausible that the IT Lib system formed in the disk about 30 million years ago and was ejected on a trajectory taking it to its present position.
John C. Martin
Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all holohedral cubic materials
Utilizing bicrystallography in two dimensions (2D), the symmetries of migration related segments of Coincidence Site Lattice (CSL) boundaries are derived for projections along their [001] tilt axis in grain boundaries of crystalline materials that possess the holohedral point symmetry of the cubic system (i.e. m3m). These kinds of �edge-on� projections are typical for atomic resolution imaging of such tilt boundaries with Transmission Electron Microscopes (TEM). This fact facilitates the visual confirmation of our predictions by recently published Zcontrast scanning TEM investigations [H. Yang et al., Phil. Mag. 93 (2013) 1219] and many other TEM studies.
Moeck, Peter; York, Bryant W.; Browning, Nigel D.
Neutron irradiation of beryllium pebbles
Seven subcapsules from the FFTF/MOTA 2B irradiation experiment containing 97 or 100% dense sintered beryllium cylindrical specimens in depleted lithium have been opened and the specimens retrieved for postirradiation examination. Irradiation conditions included 370 C to 1.6 {times} 10{sup 22} n/cm{sup 2}, 425 C to 4.8 {times} 10{sup 22} n/cm{sup 2}, and 550 C to 5.0 {times} 10{sup 22} n/cm{sup 2}. TEM specimens contained in these capsules were also retrieved, but many were broken. Density measurements of the cylindrical specimens showed as much as 1.59% swelling following irradiation at 500 C in 100% dense beryllium. Beryllium at 97% density generally gave slightly lower swelling values.
Gelles, D.S.; Ermi, R.M. [Pacific Northwest National Lab., Richland, WA (United States); Tsai, H. [Argonne National Lab., IL (United States)
Putting plant resistance traits on the map: a test of the idea that plants are better defended at lower latitudes
at lower latitudes Angela T. Moles1,2,3,4 , Ian R. Wallis3 , William J. Foley3 , David I. Warton5 , James C Biology, James Cook University, PO Box 6811,Cairns, Australia; 12 NationalEnvironmental Research InstituteSciences, University of Zambia, PO Box 32379, Lusaka 10101, Zambia;18 School of Marine and Tropical Biology, James Cook
A unique seasonal pattern in phytoplankton biomass in low-latitude waters in the South China Sea
A unique seasonal pattern in phytoplankton biomass in low-latitude waters in the South China Sea in phytoplankton biomass was observed at the South East Asian Time- series Study (SEATS) station (18°N, 116°E became readily detectable in the winter. The elevation of phytoplankton biomass coincided approximately
Wu, Chau-Ron
High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research Mark A. Bourassa1
, the Wilkins Ice Shelf collapsed equally quickly (Scambos et al. 2009). Ocean heat content is rising rapidlyHigh-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research Mark A. Bourassa1 conditions for the measurement and estimation of airsea and ice fluxes, limiting understanding of related
), and in 2008, the Wilkins Ice Shelf51 collapsed equally quickly (Scambos et al. 2009). Ocean heat content1 High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 2 Mark A conditions for the measurement and estimation of air27 sea and ice fluxes, limiting understanding of related
What is this MCMS? MCMS stands for the MAP Climatology of Mid-latitude Storminess dataset (see
arguments. Cyclone tracking is treated as a separate process and product (not shown here for brevity) depression around a mid-latitude baroclinic cyclone (or just cyclone). MCMS rests on two operations: 1) finding and tracking cyclones and 2) objectively delineating the area under each cyclones influence
Methane fluxes between terrestrial ecosystems and the atmosphere at northern high latitudes during the past century: A retrospective
Methane fluxes between terrestrial ecosystems and the atmosphere at northern high latitudes during develop and use a new version of the Terrestrial Ecosystem Model (TEM) to study how rates of methane (CH4 dynamics (3309); 1890 Hydrology: Wetlands; KEYWORDS: methane emissions, methane oxidation, permafrost
McGuire, A. David
Latitude, seed predation and seed mass A. T. Moles* and M. Westoby Department of Biological Sciences, Macquarie University,
of species from around the world. We also aimed to quantify the slope and predictive power expected that herbivory and predation might be more sustained threats there. Considerable evidence supports winter browsing intensity and latitude across six species of woody plants (Swihart & Bryant, 2001
Moles, Angela
Low energy electron irradiation of an apple
The viability of pathogenic organisms on the surface of fresh fruits and vegetables can be significantly reduced by low energy electron beam irradiation. The most difficult technical challenge for surface irradiation of fruits and vegetable...
Brescia, Giovanni Batista
Statistical criteria for characterizing irradiance time series.
We propose and examine several statistical criteria for characterizing time series of solar irradiance. Time series of irradiance are used in analyses that seek to quantify the performance of photovoltaic (PV) power systems over time. Time series of irradiance are either measured or are simulated using models. Simulations of irradiance are often calibrated to or generated from statistics for observed irradiance and simulations are validated by comparing the simulation output to the observed irradiance. Criteria used in this comparison should derive from the context of the analyses in which the simulated irradiance is to be used. We examine three statistics that characterize time series and their use as criteria for comparing time series. We demonstrate these statistics using observed irradiance data recorded in August 2007 in Las Vegas, Nevada, and in June 2009 in Albuquerque, New Mexico.
Stein, Joshua S.; Ellis, Abraham; Hansen, Clifford W.
ULF wave occurrence statistics in a high-latitude HF Doppler sounder D. M. Wright, T. K. Yeoman, T. B. Jones
ULF wave occurrence statistics in a high-latitude HF Doppler sounder D. M. Wright, T. K. Yeoman, T was to establish the optimum con®guration for a new high-latitude Doppler sounder experiment, called DOPE (Wright, 1996; Wright et al., 1997), and to determine the likelihood of the experiment observing pulsation eects
Study of the interaction of solutes with ?5 (013) tilt grain boundaries in iron using density-functional theory
Substitutional alloying elements significantly affect the recrystallization and austenite-ferrite phase transformation rates in steels. The atomistic mechanisms of their interaction with the interfaces are still largely unexplored. Using density functional theory, we determine the segregation energies between commonly used alloying elements and the ?5 (013) tilt grain boundary in bcc iron. We find a strong solute-grain boundary interaction for Nb, Mo, and Ti that is consistent with experimental observations of the effects of these alloying elements on delaying recrystallization and the austenite-to-ferrite transformation in low-carbon steels. In addition, we compute the solute-solute interactions as a function of solute pair distance in the grain boundary, which suggest co-segregation for these large solutes at intermediate distances in striking contrast to the bulk.
Jin, Hao; Militzer, Matthias [Centre for Metallurgical Process Engineering, The University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Elfimov, Ilya [Quantum Matter Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada)
A self-consistent regime of generation of terahertz radiation by an optical pulse with a tilted intensity front
We derived a self-consistent system of nonlinear wave equations describing the terahertz generation in dielectric uniaxial crystals by optical pulsed radiation with a tilted wavefront. The numerical analysis of the system of equations showed that the generation of a broadband one-period terahertz signal is accompanied by a red shift of the carrier frequency of the optical pulse, the magnitude of the shift being proportional to the pulse intensity. The generation efficiency with respect to energy reached a maximum at a certain distance of propagation in the crystal, after which the efficiency decreased. A satisfactory agreement was obtained between theoretical calculations and experimental data of other investigations. (generation of terahertz radiation)
Bugai, A N; Sazonov, S V; Shashkov, Andrei Yu
3, 895959, 2006 Irradiance and
and corals. However, the contribution of benthic communities to the primary production of the global coastal energy source fueling marine primary prBGD 3, 895959, 2006 Irradiance and primary production in the coastal ocean J.-P. Gattuso et al
sterilization by irradiation Arne Miller
-1:2006 Equipment characterization (6) Product definition (7) Process definition (8) Installation Qualification (9.1) Operational Qualification (9.2) · Performance Qualification (9.3) - later #12;3 Equipment characterization samples shall be irradiated to defined and uniform doses. #12;9 9.1 Installation qualification (A.9
Low temperature irradiation tests on
Sample cool down by He gas loop 10K � 20K Fast neutron flux Measured by Ni activation in 2010 1.4xK #12;reactor Cryogenics #12;Al-Cu-Mg He gas temperature near sample 12K Resistance changesLow temperature irradiation tests on stabilizer materials using reactor neutrons at KUR Makoto
Solar UV radiation exposure of seamen - Measurements, calibration and model calculations of erythemal irradiance along ship routes
Seamen working on vessels that go along tropical and subtropical routes are at risk to receive high doses of solar erythemal radiation. Due to small solar zenith angles and low ozone values, UV index and erythemal dose are much higher than at mid-and high latitudes. UV index values at tropical and subtropical Oceans can exceed UVI = 20, which is more than double of typical mid-latitude UV index values. Daily erythemal dose can exceed the 30-fold of typical midlatitude winter values. Measurements of erythemal exposure of different body parts on seamen have been performed along 4 routes of merchant vessels. The data base has been extended by two years of continuous solar irradiance measurements taken on the mast top of RV METEOR. Radiative transfer model calculations for clear sky along the ship routes have been performed that use satellite-based input for ozone and aerosols to provide maximum erythemal irradiance and dose. The whole data base is intended to be used to derive individual erythemal exposure of seamen during work-time.
Feister, Uwe [German Meteorological Service, Meteorological Observatory Lindenberg - Richard-Assmann-Observatory, Am Observatorium 12, 15848 Lindenberg (Germany); Meyer, Gabriele; Kirst, Ulrich [German Social Accident Insurance Institution for Transport and Traffic, Ottenser Hauptstrasse 54, 22765 Hamburg (Germany)
Irradiation-induced phenomena in carbon
Chapter 1 Irradiation-induced phenomena in carbon nanotubes To appear in "Chemistry of email@example.com 1 #12;2CHAPTER 1. IRRADIATION-INDUCED PHENOMENA IN CARBON NANOTUBES #12;Contents 1 Irradiation-induced phenomena in carbon nanotubes 1 1.1 Introduction
Krasheninnikov, Arkady V.
Transition from Irradiation-Induced Amorphization to Crystallization...
from Irradiation-Induced Amorphization to Crystallization in Nanocrystalline Silicon Carbide. Transition from Irradiation-Induced Amorphization to Crystallization in...
Occlusion-Aware Hessians for Error Control in Irradiance Caching /
Control for Irradiance Caching. � In ACM Transactions on Graphics,Control for Irradiance Caching. � In ACM Transactions on Graphics,
Schwarzhaupt, Jorge Andres
PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan and Ilya Tsvankin , Center for Wave Phenomena, Colorado School of Mines (CSM),
PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan and Ilya Tsvankin , Center for Wave Phenomena, Colorado School of Mines (CSM), Mike Batzle, Center for Rock Abuse, CSM, Kasper van Wijk, Physical Acoustics Laboratory, CSM, and Matt Haney, Center for Wave Phenomena
Measurements Versus Predictions for the Static and Dynamic Characteristics of a Four-pad Rocker-pivot, Tilting-pad Journal Bearing
Measured and predicted static and dynamic characteristics are provided for a four-pad, rocker-pivot, tilting-pad journal bearing in the load-on-pad and load-between-pad orientations. The bearing has the following characteristics: 4 pads, .57 pad...
Tschoepe, David 1987-
Measured and predicted rotordynamic coefficients and static performance of a rocker-pivot, tilt pad bearing in load-on-pad and load-between-pad configurations
This thesis presents the static and dynamic performance data for a 5 pad tilting pad bearing in both the load-on-pad (LOP) and the load-between-pad (LBP) configurations over a variety of different loads and speeds. The bearing tested was an Orion...
Carter, Clint Ryan
Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes
The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o} {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.
Abdo, A.A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; Ajello, M.; /SLAC; Anderson, B.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Taiwan, Natl. Taiwan U. /Ohio State U.; Bechtol, K.; /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; Blandford, R.D.; Bloom, E.D.; /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /SLAC; Bregeon, J.; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Stockholm U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Padua U. /Naval Research Lab, Wash., D.C. /Udine U. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Pisa /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Udine U. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Bari U. /INFN, Bari /INFN, Pisa /INFN, Bari /NASA, Goddard /Maryland U.; /more authors..
Study of mid-latitude 5577A CI dayglow emissions. Doctoral thesis
Summary of thesis: The green line (5577angstroms) is a bright, persistent component of the visible airglow. It is produced by an electric quadruple transition from the metastable second excited state (1So) to the first excited state (1D2) of atomic oxygen. These two excited states all lie in the same electron shell of the atom and have the same electron configuration as the ground state of 1s22s22p4, which is the 3P2,1,0. This emission is present in both the daytime and night airglow and in the aurora, and despite a long history of study it is still not fully understood. The emission in the dayglow and the nightglow is relatively homogeneous spatially and global in coverage. In the aurora, the emission is much brighter than the airglow, high structured and very localized being restricted to higher latitudes. The structure of the 5577angstroms emission with altitude and the chemistry responsible for the production of the emission are complex. The vertical structure for the emission has two distinct layers in the airglow each with its own set of production and loss mechanisms. the chemistry for either of these layers is not completely known. The auroral emission is not understood either since it overlaps the upper and lower layer altitudes and it tends to contain some parts of the chemistry of both layers as sources and losses.
Hume, E.E.
High Latitude, Translucent Molecular Clouds as Probes of Local Cosmic Rays
We analyze the gamma-ray emission from 9 high latitude, translucent molecular clouds taken with the Fermi Large Area Telescope (LAT) between 250 MeV and 10 GeV. Observations of gamma-rays allow us to probe the density and spectrum of cosmic rays in the solar neighborhood. The clouds studied lie within $\\sim\\!$270 pc from the Sun and are selected from the Planck all-sky CO map. Gamma-rays in this energy range mostly result from cosmic ray interactions with the interstellar medium, which is traced with three components: HI, CO, and dark gas. Every cloud is detected and shows significant, extended gamma-ray emission from molecular gas. The gamma-ray emission is dominated by the CO-emitting gas in some clouds, but by the CO-dark gas in others. The average emissivity and gamma-ray power law index from HI above 1 GeV shows no evidence of a systematic variation. The CO-to-H$_2$ conversion factor shows no variation between clouds over this small spatial range, but shows significant variations within each cloud. The a...
Abrahams, R D
Is the northern high latitude land-based CO2 sink weakening?
Studies indicate that, historically, terrestrial ecosystems of the northern high latitude region may have been responsible for up to 60% of the global net land-based sink for atmospheric CO2. However, these regions have recently experienced remarkable modification of the major driving forces of the carbon cycle, including surface air temperature warming that is significantly greater than the global average and associated increases in the frequency and severity of disturbances. Whether arctic tundra and boreal forest ecosystems will continue to sequester atmospheric CO2 in the face of these dramatic changes is unknown. Here we show the results of model simulations that estimate a 41 Tg C yr-1 sink in the boreal land regions from 1997 to 2006, which represents a 73% reduction in the strength of the sink estimated for previous decades in the late 20th Century. Our results suggest that CO2 uptake by the region in previous decades may not be as strong as previously estimated. The recent decline in sink strength is the combined result of 1) weakening sinks due to warming-induced increases in soil organic matter decomposition and 2) strengthening sources from pyrogenic CO2 emissions as a result of the substantial area of boreal forest burned in wildfires across the region in recent years. Such changes create positive feedbacks to the climate system that accelerate global warming, putting further pressure on emission reductions to achieve atmospheric stabilization targets.
Mcguire, David [University of Alaska; Kicklighter, David W. [Ecosystem Center, The; Gurney, Kevin R [Arizona State University; Burnside, Todd [University of Alaska, Fairbanks; Melillo, Jerry [Marine Biological Laboratory
GTL-1 Irradiation Summary Report
The primary objective of the Gas Test Loop (GTL-1) miniplate experiment is to confirm acceptable performance of high-density (i.e., 4.8 g-U/cm3) U3Si2/Al dispersion fuel plates clad in Al-6061 and irradiated under the relatively aggressive Booster Fast Flux Loop (BFFL) booster fuel conditions, namely a peak plate surface heat flux of 450 W/cm2. As secondary objectives, several design and fabrication variations were included in the test matrix that may have the potential to improve the high-heat flux, high-temperature performance of the base fuel plate design.1, 2 The following report summarizes the life of the GTL-1 experiment through end of irradiation, including as-run neutronic analysis, thermal analysis and hydraulic testing results.
D. M. Perez; G. S. Chang; N. E. Woolstenhulme; D. M. Wachs
RERTR-6 Irradiation Summary Report
The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-6 was designed to evaluate several modified fuel designs that were proposed to address the possibility of breakaway swelling due to porosity within the (U. Mo) Al interaction product observed in the full-size plate tests performed in Russia and France1. The following report summarizes the life of the RERTR-6 experiment through end of irradiation, including as-run neutronic analyses, thermal analyses and hydraulic testing results.
D. M. Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs
RERTR-13 Irradiation Summary Report
The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-13 was designed to assess performance of different types of neutron absorbers that can be potentially used as burnable poisons in the low enriched uranium-molybdenum based dispersion and monolithic fuels.1 The following report summarizes the life of the RERTR-13 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.
D. M. Perez; M. A. Lillo; G. S. Chang; D. M. Wachs; G. A. Roth; N. E. Woolstenhulme
Nuclear plant irradiated steel handbook
This reference handbook presents selected information extracted from the EPRI reactor surveillance program database, which contains the results from surveillance program reports on 57 plants and 116 capsules. Tabulated data includes radiation induced temperature shifts, capsule irradiation conditions and statistical features of the Charpy V-notch curves. General information on the surveillance materials is provided and the Charpy V-notch energy results are presented graphically.
Oldfield, W.; Oldfield, F.M.; Lombrozo, P.M.; McConnell, P.
An analysis of modified convective available potential energy and Richardson number in mid-latitude squall line environments
modified convective available potential energy (MCAPE) and Richardson number (MRI) were computed for each upper air sounding in a synoptic ? scale data network. The resulting fields were contoured and compared to the development, growth and decay of mid... ? latitude squall lines in several cases studies. The results indicate that, though the squall lines remained in the vicinity of MCAPE maxima and MRI minima there was no quantitative association. The squall lines also appeared to avoid these regions...
Stricherz, James Nicholas
Petrology of a dredged cumulate-textured gabboric complex from the mid-Atlantic ridge, latitude 26?N
: (Chairman of Committee) (Head of Department) (Nembe r) (Nembe Nay 1977 ABSTRACT Petrology of a Dredged Cumulate- Textured Gabbroic Complex from the Nid-Atlantic ridge, Latitude 26 N. (Nay l977) Lawrence James Tiezzi, D. S. , Rensselaer Polytechnic... Oceanographic and Atmospheric Administration and the U. S. S. R. Academy of Sciences Institute of Oceanology. This research project was funded by NSF grant OCE 74-18567. TABLE OF CONTENTS Introduction Background Location and Setting Research Methods...
Tiezzi, Lawrence James
EPR Investigation of Irradiated Curry Powder
Gamma-ray irradiated curry powder, a well priced oriental spice was investigated in order to establish the ability of EPR to detect the presence and time stability of free irradiation free-radicals. Accordingly, curry powder aliquots were irradiated with gradually increasing absorbed doses up to 11.3 kGy. The EPR spectra of all irradiated samples show the presence of al last two different species of free radicals, whose concentration increased monotonously with the absorbed doses. A 100 deg. C isothermal annealing of irradiated samples has shown a differential reduction of amplitude of various components of the initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after more than one year storage at room temperature, all of them being very useful in establishing the existence of any previous irradiation treatment.
Duliu, O. G.; Ali, S. I. [University of Bucharest, Department of Atomic and Nuclear Physics, P.O. Box MG-11, 077125 Bucharest (Romania); Georgescu, R. [National Institute for Physics and Nuclear Engineering-Horia Hulubei, P.O. Box MG-6, 077125 Bucharest (Romania)
Automatic recovery of missing amplitudes and phases in tilt-limited electron crystallography of two-dimensional crystals
Electron crystallography of 2D protein crystals provides a powerful tool for the determination of membrane protein structure. In this method, data is acquired in the Fourier domain as randomly sampled, uncoupled, amplitudes and phases. Due to physical constraints on specimen tilting, those Fourier data show a vast un-sampled ''missing cone'' of information, producing resolution loss in the direction perpendicular to the membrane plane. Based on the flexible language of projection onto sets, we provide a full solution for these problems with a projective constraint optimization algorithm that, for sufficiently oversampled data, produces complete recovery of unmeasured data in the missing cone. We apply this method to an experimental data set of Bacteriorhodopsin and show that, in addition to producing superior results compared to traditional reconstruction methods, full, reproducible, recovery of the missing cone from noisy data is possible. Finally, we present an automatic implementation of the refinement routine as open source, freely distributed, software that will be included in our 2dx software package.
Gipson, Bryant R.; Stahlberg, Henning [Center for Cellular Imaging and Nano Analytics (C-CINA), Biozentrum, University Basel, WRO-1058 Mattenstrasse 26, CH-4058 Basel (Switzerland); Masiel, Daniel J.; Browning, Nigel D. [Department of Chemical Engineering and Materials Sciences, University of California at Davis, Davis, California 95616 (United States); Spence, John [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Mitsuoka, Kaoru [Biomedicinal Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-3-26, Aomi, Koto-ku, Tokyo 135-0064 (Japan)
Methane Fluxes Between Terrestrial Ecosystems and the Atmosphere at Northern High Latitudes During the Past Century: A retrospective analysis with a process-based biogeochemistry model
We develop and use a new version of the Terrestrial Ecosystem Model (TEM) to study how rates of methane (CH4) emissions and consumption in high-latitude soils of the Northern Hemisphere have changed over the past century ...
Zhuang, Qianlai.
We have conducted B-, g-, V-, and R-band imaging in a 45' Multiplication-Sign 40' field containing part of the high Galactic latitude translucent cloud MBM32, and correlated the intensity of diffuse optical light S{sub {nu}}({lambda}) with that of 100 {mu}m emission S{sub {nu}}(100 {mu}m). A {chi}{sup 2} minimum analysis is applied to fit a linear function to the measured correlation and derive the slope parameter b({lambda}) = {Delta}S{sub {nu}}({lambda})/{Delta}S{sub {nu}}(100 {mu}m) of the best-fit linear function. Compiling a sample by combining our b({lambda}) and published ones, we show that the b({lambda}) strength varies from cloud to cloud by a factor of four. Finding that b({lambda}) decreases as S{sub {nu}}(100 {mu}m) increases in the sample, we suggest that a nonlinear correlation including a quadratic term of S{sub {nu}}(100 {mu}m){sup 2} should be fitted to the measured correlation. The variation of optical depth, which is A{sub V} = 0.16-2.0 in the sample, can change b({lambda}) by a factor of 2-3. There would be some contribution to the large b({lambda}) variation from the forward-scattering characteristic of dust grains which is coupled to the non-isotropic interstellar radiation field (ISRF). Models of the scattering of diffuse Galactic light (DGL) underestimate the b({lambda}) values by a factor of two. This could be reconciled by deficiency in UV photons in the ISRF or by a moderate increase in dust albedo. Our b({lambda}) spectrum favors a contribution from extended red emission (ERE) to the diffuse optical light; b({lambda}) rises from B to V faster than the models, seems to peak around 6000 A and decreases toward long wavelengths. Such a characteristic is expected from the models in which the DGL is combined with ERE.
Ienaka, N.; Kawara, K. [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)] [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Matsuoka, Y.; Oyabu, S. [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)] [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Sameshima, H. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8501 (Japan)] [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8501 (Japan); Tsujimoto, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Peterson, B. A., E-mail: email@example.com [Research School of Astronomy and Astrophysics, The Australian National University, Weston Creek, ACT 2611 (Australia)
Strain Accommodation By Facile WO6 Octahedral Distortion and Tilting During WO3 Heteroepitaxy on SrTiO3(001)
In this paper, we show that compared to other BO6 octahedra in ABO3 structured perovskite oxides, the WO6 octahedra in tungsten trioxide (WO3) can withstand a much larger degree of distortion and tilting to accommodate interfacial strain, which in turn strongly impact the nucleation, structure, and defect formation during the epitaxial growth of WO3 on SrTiO3(001). A meta-stable tetragonal phase can be stabilized by epitaxy and a thickness dependent phase transition (tetragonal to monoclinic) is observed. In contrast to misfit dislocations to accommodate the interfacial stain, the facial WO6 octahedral distortion and tilting give rise to three types of planar defects that affect more than 15 monolayers from the interface. These atomically resolved, unusual interfacial defects may significantly alter the electronic, electrochromic, and mechanical properties of the epitaxial films.
Du, Yingge; Gu, Meng; Varga, Tamas; Wang, Chong M.; Bowden, Mark E.; Chambers, Scott A.
Sodium and potassium levels in the serum of acutely irradiated and non-irradiated rats
SODIUM AND POTASSIUM LEVELS IN THE SERUM OF ACUTELY IRRADIATED AND NON-IRRADIATED RATS A Thesis By DAVID PRESTON SHEPHERD Submitted to the Graduate College of the Texas ARM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1967 Major Subject: Zoology SODIUM AND POTASSIUM LEVELS IN THE SERUM OF ACUTELY IRRADIATED AND NON-IRRADIATED RATS A Thesis By DAVID PRESTON SHEPHERD Approved as to style and content by: (Chairman of Committee) (Head...
Shepherd, David Preston
High latitudes present extreme conditions for the measurement and estimation of airsea and ice fluxes, limiting understanding of related physical processes and
High latitudes present extreme conditions for the measurement and estimation of airsea and ice of the Earth's climate. HigH-LatitudE OcEan and SEa icE SurfacE fLuxES: cHaLLEngES fOr cLimatE rESEarcH by Mark change can manifest itself in astonishing ways. Arctic sea ice extent at the end of the melt season
Renfrew, Ian
Effect of electron-density gradients on propagation of radio waves in the mid-latitude trough. Master's thesis
Partial contents of this thesis include: (1) Radio-wave propagation and the mid-latitude trough; (2) Ionospheric measurements; (3) Modification of time-dependent ionospheric model output with latitudinal electron-density profiles from digisonde trough depictions; (4) Ray-tracing simulations to examine ground range; and (5) Effects of three-dimensional gradients in electron density on radio-wave propagation in the trough region. Data is tabulated for geophysical conditions, solar activity level, geomagnetic activity level, conditions for vertical ray refraction to surface, and ray-tracing fixed-input conditions.
Citrone, P.J.
Nuclear Engineering Division Irradiated Materials Laboratory
Nuclear Engineering Division Irradiated Materials Laboratory The Irradiated Materials Laboratory (IML) in Argonne's Nuclear Engineering Division is used to conduct research on the behavior. #12;C O N TA C T > Dr. Michael C. Billone | 630-252-7146 | email@example.com | Nuclear Engineering
Kemner, Ken
AGC-1 Irradiation Experiment Test Plan
The Advanced Graphite Capsule (AGC) irradiation test program supports the acquisition of irradiated graphite performance data to assist in the selection of the technology to be used for the VHTR. Six irradiations are planned to investigate compressive creep in graphite subjected to a neutron field and obtain irradiated mechanical properties of vibrationally molded, extruded, and iso-molded graphites for comparison. The experiments will be conducted at three temperatures: 600, 900, and 1200�C. At each temperature, two different capsules will be irradiated to different fluence levels, the first from 0.5 to 4 dpa and the second from 4 to 7 dpa. AGC-1 is the first of the six capsules designed for ATR and will focus on the prismatic fluence range.
R. L. Bratton
Irradiation-induced defect clustering and amorphization in silicon...
Irradiation-induced defect clustering and amorphization in silicon carbide. Irradiation-induced defect clustering and amorphization in silicon carbide. Abstract: Previous computer...
Neutron Irradiation of Hydrided Cladding Material in HFIR Summary...
Broader source: Energy.gov (indexed) [DOE]
Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities...
Magnetization measurements and XMCD studies on ion irradiated...
measurements and XMCD studies on ion irradiated iron oxide and core-shell ironiron-oxide nanomaterials. Magnetization measurements and XMCD studies on ion irradiated iron oxide...
RERTR-7 Irradiation Summary Report
The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-7A, was designed to test several modified fuel designs to target fission densities representative of a peak low enriched uranium (LEU) burnup in excess of 90% U-235 at peak experiment power sufficient to generate a peak surface heat flux of approximately 300 W/cm2. The RERTR-7B experiment was designed as a high power test of 'second generation' dispersion fuels at peak experiment power sufficient to generate a surface heat flux on the order of 230 W/cm2.1 The following report summarizes the life of the RERTR-7A and RERTR-7B experiments through end of irradiation, including as-run neutronic analyses, thermal analyses and hydraulic testing results.
The effects of coronal mass ejection on galactic cosmic rays in the high latitude heliosphere: Observations from Ulysses` first orbit
During its first solar orbit the Ulysses spacecraft detected several coronal mass ejections (CMEs) at high heliographic latitudes. The authors present first observations on the effects of these high latitude CMEs on galactic cosmic rays (GCRs) using measurements from the Kiel Electron Telescope (KET) which is part of the Cosmic Ray and Solar Particle Investigation (COSPIN) experiment, the Los Alamos SWOOPS (Solar Wind Observations Over the Poles of the Sun) experiment and the magnetic field experiments. They find the passage of these CMEs over the spacecraft to be associated with short term decreases of GCR intensities The relatively weak shocks in these events, driven by the CMEs` over-expansion, had no strong influence on the GCRs. The intensity minimums of GCRs occurred on closed magnetic field lines inside the CMEs themselves as indicated by bidirectional fluxes of suprathermal electrons. Short episodes of intensity increases of GCRs inside CMEs at times when the bidirectional fluxes of suprathermal electrons disappeared, can be interpreted as evidence that GCRs can easily access the interior of those CMEs in which open magnetic field lines are embedded.
Bothmer, V.; Heber, B.; Kunow, H.; Mueller-Mellin, R.; Wibberenz, G. [Univ. of Kiel (Germany). Institut fuer Kernphysik; Gosling, J.T. [Los Alamos National Lab., NM (United States); Balogh, A. [Imperial College, London (United Kingdom). Blackett Lab.; Raviart, A. [CEA, Gif-sur-Yvette (France). Service d`Astrophysique; Paizis, C. [Univ. di Milano (Italy). Istituto di Fisica Cosmica CNR
Discovery of two embedded clusters with WISE in the high Galactic latitude cloud HRK 81.4-77.8
Molecular clouds at very high latitude ($b>60^{\\circ}$) away from the Galactic plane are rare and in general are expected to be non-star-forming. However, we report the discovery of two embedded clusters (Camargo 438 and Camargo 439) within the high-latitude molecular cloud HRK 81.4-77.8 using WISE. Camargo 439 with Galactic coordinates $\\ell=81.11^{\\circ}$ and $b=-77.84^{\\circ}$ is an $\\sim2$ Myr embedded cluster (EC) located at a distance from the Sun of $d_{\\odot}=5.09\\pm0.47$ kpc. Adopting the distance of the Sun to the Galactic centre $R_{\\odot}=7.2$ kpc we derive for Camargo 439 a Galactocentric distance of $R_{GC}=8.70\\pm0.26$ kpc and a vertical distance from the plane of $-4.97\\pm0.46$ kpc. Camargo 438 at $\\ell=79.66^{\\circ}$ and $b=-78.86^{\\circ}$ presents similar values. The derived parameters for these two ECs put HRK 81.4-77.8 in the halo at a distance from the Galactic centre of $\\sim8.7$ kpc and $\\sim5.0$ kpc from the disc. Star clusters provide the only direct means to determine the high latitu...
Camargo, Denilso; Bonatto, Charles; Salerno, Gustavo
AGC-1 Post Irradiation Examination Status
The Next Generation Nuclear Plant (NGNP) Graphite R&D program is currently measuring irradiated material property changes in several grades of nuclear graphite for predicting their behavior and operating performance within the core of new Very High Temperature Reactor (VHTR) designs. The Advanced Graphite Creep (AGC) experiment consisting of six irradiation capsules will generate this irradiated graphite performance data for NGNP reactor operating conditions. All six AGC capsules in the experiment will be irradiated in the Advanced Test Reactor (ATR), disassembled in the Hot Fuel Examination Facility (HFEF), and examined at the INL Research Center (IRC) or Oak Ridge National Laboratory (ORNL). This is the first in a series of status reports on the progress of the AGC experiment. As the first capsule, AGC1 was irradiated from September 2009 to January 2011 to a maximum dose level of 6-7 dpa. The capsule was removed from ATR and transferred to the HFEF in April 2011 where the capsule was disassembled and test specimens extracted from the capsules. The first irradiated samples from AGC1 were shipped to the IRC in July 2011and initial post irradiation examination (PIE) activities were begun on the first 37 samples received. PIE activities continue for the remainder of the AGC1 specimen as they are received at the IRC.
David Swank
AGR-1 Irradiation Experiment Test Plan
This document presents the current state of planning for the AGR-1 irradiation experiment, the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The objectives of the AGR-1 experiment are: 1. To gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. 2. To irradiate fuel produced in conjunction with the AGR fuel process development effort. 3. To provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. In order to achieve the test objectives, the AGR-1 experiment will be irradiated in the B-10 position of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). The test will contain six independently controlled and monitored capsules. Each capsule will contain a single type, or variant, of the AGR coated fuel. The irradiation is planned for about 700 effective full power days (approximately 2.4 calendar years) with a time-averaged, volume-average temperature of approximately 1050 �C. Average fuel burnup, for the entire test, will be greater than 17.7 % FIMA, and the fuel will experience fast neutron fluences between 2.4 and 4.5 x 1025 n/m2 (E>0.18 MeV).
John T. Maki
RERTR-12 Insertion 2 Irradiation Summary Report
The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-12 was designed to provide comprehensive information on the performance of uranium-molybdenum (U-Mo) based monolithic fuels for research reactor applications.1 RERTR-12 insertion 2 includes the capsules irradiated during the last three irradiation cycles. These capsules include Z, Y1, Y2 and Y3 type capsules. The following report summarizes the life of the RERTR-12 insertion 2 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.
D. M. Perez; G. S. Chang; D. M. Wachs; G. A. Roth; N. E. Woolstenhulme
Measuring Degradation Rates Without Irradiance Data
A method to report PV system degradation rates without using irradiance data is demonstrated. First, a set of relative degradation rates are determined by comparing daily AC final yields from a group of PV systems relative to the average final yield of all the PV systems. Then, the difference between relative and absolute degradation rates is found from a statistical analysis. This approach is verified by comparing to methods that utilize irradiance data. This approach is significant because PV systems are often deployed without irradiance sensors, so the analysis method described here may enable measurements of degradation using data that were previously thought to be unsuitable for degradation studies.
Pulver, S.; Cormode, D.; Cronin, A.; Jordan, D.; Kurtz, S.; Smith, R.
Supine Craniospinal Irradiation Using Intrafractional Junction Shifts and Field-in-Field Dose Shaping: Early Experience at Methodist Hospital
Purpose: To describe our preliminary experience with supine craniospinal irradiation. The advantages of the supine position for craniospinal irradiation include patient comfort, easier access to maintain an airway for anesthesia, and reduced variability of the head tilt in the face mask. Methods and Materials: The cranial fields were treated with near lateral fields and a table angle to match their divergence to the superior edge of the spinal field. The collimator was rotated to match the divergence from the superior spinal field. The spinal fields were treated using a source to surface distance (SSD) technique with the couch top at 100 cm. When a second spinal field was required, the table and collimator were rotated 90{sup o} to allow for the use of the multileaf collimator and so the gantry could be rotated to match the divergence of the superior spinal field. The multileaf collimator was used for daily dynamic featherings and field-in-field dose control. Results: With a median follow-up of 20.2 months, five documented failures and no cases of radiation myelitis occurred in 23 consecutive patients. No failures occurred in the junctions of the spine-spine or brain-spine fields. Two failures occurred in the primary site alone, two in the spinal axis alone, and one primary site failure plus distant metastasis. The median time to recurrence was 17 months. Conclusion: The results of our study have shown that supine approach for delivering craniospinal irradiation is not associated with increased relapses at the field junctions. To date, no cases of radiation myelitis have developed.
South, Michael C. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States)], E-mail: email@example.com; Chiu, J. Kam; Teh, Bin S. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States); Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States); Bloch, Charles [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States); Schroeder, Thomas M. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States); Department of Radiation Oncology, University of New Mexico, Albuquerque, NM (United States); Paulino, Arnold C. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States); Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States)
Investigation into the failure cause of a double-acting, leading-edge-groove, tilting-pad thrust bearing. Final report, Feb-Aug 90
This report describes the results of bench tests simulating operation and failure of a thrust bearing used in a gas turbine engine compressor development test rig. The bearing was a double acting, tilting pad with offset pivot, leading edge groove configuration using an AMS 4928 titanium collar and C18200 copper-chrome alloy pads with a No. 2 babbitt face. The bench tests successfully simulated the bearing failure and demonstrated a materials incompatibility. This was supported by visual examination, scanning electron microscopy and X-ray energy spectroscopy. A comparison of the bench test results to the compressor rig bearing failure is provided to support the report conclusions.
Peterson, B.K.
Introduction The bay scallop, Argopecten irradi-
71(3) 17 Introduction The bay scallop, Argopecten irradi- ans amplicostatus, has been present (Garcia-Cubas, 1968). Historical Uses Mollusks were used by the pre-Co- lumbian cultures in Mexico as food
Selective irradiation of the vascular endothelium
We developed a unique methodology to selectively irradiate the vascular endothelium in vivo to better understand the role of vascular damage in causing normal tissue radiation side-effects.The relationship between vascular ...
Schuller, Bradley W
Processing Irradiated Beryllium For Disposal
The purpose of this research was to develop a process for decontaminating irradiated beryllium that will allow it to be disposed of through normal radwaste channels. Thus, the primary objectives of this ongoing study are to remove the transuranic (TRU) isotopes to less than 100 nCi/g and remove {sup 60}Co, and {sup 137}Cs, to levels that will allow the beryllium to be contact handled. One possible approach that appears to have the most promise is aqueous dissolution and separation of the isotopes by selected solvent extraction followed by precipitation, resulting in a granular form for the beryllium that may be fixed to prevent it from becoming respirable and therefore hazardous. Beryllium metal was dissolved in nitric and fluorboric acids. Isotopes of {sup 241}Am, {sup 239}Pu, {sup 85}Sr, and {sup 137}Cs were then added to make a surrogate beryllium waste solution. A series of batch contacts was performed with the spiked simulant using chlorinated cobalt dicarbollide (CCD) and polyethylene glycol diluted with sulfone to extract the isotopes of Cs and Sr. Another series of batch contacts was performed using a combination of octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in tributyl phosphate (TBP) diluted with dodecane for extracting the isotopes of Pu and Am. The results indicate that greater than 99.9% removal can be achieved for each isotope with only three contact stages.
T. J. Tranter; R. D. Tillotson; N. R. Mann; G. R. Longhurst
Neutron Irradiation Measurement for Superconducting Magnet
close to reactor core � Sample cool down by He gas loop: 10K � 20K � Fast neutron flux (En>0.1MeV): 1.4x. Materials, 49, p161 (1973&74) Reactor n on Al Reactor n on Cu fluence up to 2*1022 n/m2 (En>0.1MeV) RRR Irradiation at KUR � Kyoto Univ. Research Reactor Institute � MW max. thermal power � Irradiation cryostat
Major shifts in calcareous phytoplankton assemblages through the Eocene-Oligocene transition of Tanzania and their implications for low-latitude primary production
in the deep sea, significant glaciomarine sedimen- tation commences around the margins of both East and West Antarctica indicating the first Cenozoic advance of conti- nental-scale ice sheets in southern high latitudes [Breza and Wise, 1992; Ivany et al., 2006... patterns. In low south- ern latitudes the present-day western boundary of the Indian Ocean is dominated by the northward flowing East African Coastal Current (EACC), which is sourced from the west- ward flowing South Equatorial Current (SEC) [Swallow et al...
Jones, Tom Dunkley; Bown, Paul R.; Pearson, Paul N.; Wade, Bridget S.; Coxall, Helen K.; Lear, Caroline H.
Comparison of Deuterium Retention for Ion-irradiated and Neutron-irradiated Tungsten
The behavior of D retention for Fe{sup 2+}-irradiated tungsten with a damage of 0.025-3 dpa was compared with that for neutron-irradiated tungsten with 0.025 dpa. The D{sub 2} thermal desorption spectroscopy (TDS) spectra for Fe{sup 2+}-irradiated tungsten consisted of two desorption stages at 450 and 550 K, while that for neutron-irradiated tungsten was composed of three stages and an addition desorption stage was found at 750 K. The desorption rate of the major desorption stage at 550K increased as the displacement damage increased due to Fe{sup 2+} irradiation increasing. In addition, the first desorption stage at 450K was found only for damaged samples. Therefore, the second stage would be based on intrinsic defects or vacancy produced by Fe{sup 2+} irradiation, and the first stage should be the accumulation of D in mono-vacancy and the activation energy would be relatively reduced, where the dislocation loop and vacancy is produced. The third one was found only for neutron irradiation, showing the D trapping by a void or vacancy cluster, and the diffusion effect is also contributed to by the high full-width at half-maximum of the TDS spectrum. Therefore, it can be said that the D{sub 2} TDS spectra for Fe{sup 2+}-irradiated tungsten cannot represent that for the neutron-irradiated one, indicating that the deuterium trapping and desorption mechanism for neutron-irradiated tungsten is different from that for the ion-irradiated one.
Yasuhisa Oya; Masashi Shimada; Makoto Kobayashi; Takuji Oda; Masanori Hara; Hideo Watanabe; Yuji Hatano; Pattrick Calderoni; Kenji Okuno
Northern mid-latitude glaciation in the Late Amazonian period of Mars: Criteria for the recognition of debris-covered glacier and valley glacier landsystem deposits
of debris-covered glacier and valley glacier landsystem deposits James W. Head a, , David R. Marchant b-latitude regions of Mars since documented by Viking; their flow-like character suggested that deposition of ice of which are preserved today beneath residual sublimation till derived from adjacent valley walls
Marchant, David R.
Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)
Stan Wullschleger of Oak Ridge National Laboratory on "Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems" on March 22, 2012 at the 7th Annual Genomics of Energy & Environment Meeting in Walnut Creek, California.
Wullschleger, Stan [ORNL] [ORNL
arXiv:0908.1824v2[physics.comp-ph]24Feb2010 The calculation of longitude and latitude from geodesic measurements
arXiv:0908.1824v2[physics.comp-ph]24Feb2010 The calculation of longitude and latitude from geodesic, 2009; revised: February 24, 2010) 1. INTRODUCTION Consider a geodesic line between two points A and B by deriving the fundamental properties of geodesic lines on a spheroid of revolution. Even though aspects
Karney, Charles
ScienceCinema (OSTI)
Wullschleger, Stan [ORNL
E-Print Network 3.0 - additive irradiation procedures Sample...
irradiation procedures Search Powered by Explorit Topic List Advanced Search Sample search results for: additive irradiation procedures Page: << < 1 2 3 4 5 > >> 1 IRRADIANCE MAPS...
Horizontal modular dry irradiated fuel storage system
A horizontal, modular, dry, irradiated fuel storage system (10) includes a thin-walled canister (12) for containing irradiated fuel assemblies (20), which canister (12) can be positioned in a transfer cask (14) and transported in a horizontal manner from a fuel storage pool (18), to an intermediate-term storage facility. The storage system (10) includes a plurality of dry storage modules (26) which accept the canister (12) from the transfer cask (14) and provide for appropriate shielding about the canister (12). Each module (26) also provides for air cooling of the canister (12) to remove the decay heat of the irradiated fuel assemblies (20). The modules (26) can be interlocked so that each module (26) gains additional shielding from the next adjacent module (26). Hydraulic rams (30) are provided for inserting and removing the canisters (12) from the modules (26).
Fischer, Larry E. (Los Gatos, CA); McInnes, Ian D. (San Jose, CA); Massey, John V. (San Jose, CA)
Laboratory for Characterization of Irradiated Graphite
The newly completed Idaho National Laboratory (INL) Carbon Characterization Laboratory (CCL) is located in Labs C19 and C20 of the Idaho National Laboratory Research Center (IRC). The CCL was established under the Next Generation Nuclear Plant (NGNP) Project to support graphite and ceramic composite research and development activities. The research is in support of the Advanced Graphite Creep (AGC) experiment � a major material irradiation experiment within the NGNP Graphite program. The CCL is designed to characterize and test low activated irradiated materials such as high purity graphite, carbon-carbon composites, and silicon-carbide composite materials. The laboratory is fully capable of characterizing material properties for both irradiated and nonirradiated materials.
Karen A. Moore
Irradiation creep of vanadium-base alloys.
A study of irradiation creep in vanadium-base alloys is underway with experiments in the Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR) in the US. Test specimens are thin-wall sealed tubes with internal pressure loading. The results from the initial ATR irradiation at low temperature (200-300 C) to a neutron damage level of 4.7 dpa show creep rates ranging from {approx}0 to 1.2 x 10{sup {minus}5}/dpa/MPa for a 500-kg heat of V-4Cr-4Ti alloy. These rates were generally lower than reported from a previous experiment in BR-10. Because both the attained neutron damage levels and the creep strains were low in the present study, however, these creep rates should be regarded as only preliminary. Substantially more testing is required before a data base on irradiation creep of vanadium alloys can be developed and used with confidence.
Tsai, H.; Matsui, H.; Billone, M. C.; Strain, R. V.; Smith, D. L.
Irradiation effects on borosilicate waste glasses
The effects of alpha decay on five borosilicate glasses containing simulated nuclear high-level waste oxides were studied. Irradiations carried out at room temperature were achieved by incorporating 1 to 8 wt % /sup 244/Cm/sub 2/O/sub 3/ in the glasses. Density changes and stored-energy build-up saturated at doses less than 2 x 10/sup 21/ alpha decays/kg. Damage manifested by stored energy was completely annealed at 633/sup 0/K. Positive and negative density changes were observed which never exceeded 1%. Irradiation had very little effect on mechanical strength or on chemical durability as measured by aqueous leach rates. Also, no effects were observed on the microstructure for vitreous waste glasses, although radiation-induced microcracking could be achieved on specimens that had been devitrified prior to irradiation.
Roberts, F.P.
Heavy ion irradiation of crystalline water ice
Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic ...
Dartois, E; Boduch, P; Brunetto, R; Chabot, M; Domaracka, A; Ding, J J; Kamalou, O; Lv, X Y; Rothard, H; da Silveira, E F; Thomas, J C
A Geochemical and Sedimentary Record of High Southern Latitude Holocene Climate Evolution from Lago Fagnano, Tierra del Fuego
Situated at the southern margin of the hemispheric westerly wind belt and immediately north of the Antarctic Polar Frontal zone, Tierra del Fuego is well-positioned to monitor coupled changes in the ocean-atmosphere system of the high southern latitudes. Here we describe a Holocene paleoclimate record from sediment cores obtained from Lago Fagnano, a large lake in southern Tierra del Fuego at 55{sup o}S, to investigate past changes in climate related to these two important features of the global climate system. We use an AMS radiocarbon chronology for the last 8,000 years based on pollen concentrates, thereby avoiding contamination from bedrock-derived lignite. Our chronology is consistent with a tephrochronologic age date for deposits from the middle Holocene Volcan Hudson eruption. Combining bulk organic isotopic ({delta}{sup 13}C and {delta}{sup 15}N) and elemental (C and N) parameters with physical sediment properties allow us to better understand sediment provenance and transport mechanisms and to interpret Holocene climate and tectonic change during the last 8,000 years. Co-variability and long-term trends in C/N ratio, carbon accumulation rate, and magnetic susceptibility reflect an overall Holocene increase in the delivery of terrestrial organic and lithogenic material to the deep eastern basin. We attribute this variability to westerly wind-derived precipitation. Increased wind strength and precipitation in the late Holocene drives the Nothofagus forest eastward and enhances run-off and terrigenous inputs to the lake. Superimposed on the long-term trend are a series of abrupt 9 negative departures in C/N ratio, which constrain the presence of seismically-driven mass flow events in the record. We identify an increase in bulk {delta}{sup 13}C between 7,000 and 5,000 cal yr BP that we attribute to enhanced aquatic productivity driven by warmer summer temperatures. The Lago Fagnano {delta}{sup 13}C record shows similarities with Holocene records of sea surface temperature from the mid-latitude Chilean continental shelf and Antarctic air temperatures from the Taylor Dome ice core record in East Antarctica. Mid-Holocene warming occurred simultaneously across the Antarctic Frontal Zone, and in particular, in locations currently influenced by the Antarctic Circumpolar Current.
Moy, C M; Dunbar, R B; Guilderson, T P; Waldmann, N; Mucciarone, D A; Recasens, C; Austin, J A; Anselmetti, F S
Heavy-Section Steel Irradiation Program
Maintaining the integrity of the reactor pressure vessel (RPV) in a light-water-cooled nuclear power plant is crucial in preventing and controlling severe accidents that have the potential for major contamination release. Because the RPV is the only key safety-related component of the plant for which a redundant backup system does not exist, it is imperative to fully understand the degree of irradiation-induced degradation of the RPV's fracture resistance that occurs during service. For this reason, the Heavy-Section Steel Irradiation (HSSI) Program has been established.
Rosseel, T.M.
Gamma irradiation of the prenatal mouse dentition
as the dental lamina to the stage of the deposition of enamel and dentin. The purpose of this study was to determine the effect of a continuous stress of gamma irradiation on the structure of the odontogenic cells, the relative size and rate of development... development. In 1927, Leist (9) made a study of the effect of X-rays on teeth, which was brought about by the following rase. A worker in a Roentgen tube factory was exposed daily to a considerable dose of X-irradiation. Sometime later he began to show...
Kerley, Michael Auston
Effects of neutron flux and irradiation temperature on irradiation embrittlement of A533B steels
Irradiation embrittlement of A533B steels with low copper contents were investigated from the point of dose rate and irradiation temperature effects. Change of neutron flux in the range from {minus}10{sup 12} to {minus}10{sup 13} n/cm{sup 2}/s (E > 1 MeV) did not have a significant effect on the embrittlement. Irradiation temperature change of 1 C resulted in the transition temperature shift ({Delta}T{sub 41J}) of about 1 C and yield stress change ({Delta}{sigma}{sub y}) of about 0.8 MPa. Factors that might affect the embrittlement of low copper steels are also discussed.
Suzuki, Masahide; Onizawa, Kunio; Kizaki, Minoru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)
Fructolysis in the semen of continuously irradiated and non-irradiated goats
Abbott showed that the androgenic activity of the testis is far more resistant to x- ray irradiation than is the germinal epi- 1 thelium. When Abbott administered 5, 000 and 10, OOOR to rats, he found no decrease in the sex accessory organ weights nor.... Another point which supports the data that the damaged spermatogonia give rise to subnormal sperm is 23 the studies done with in vitro sperm that have been irradiated. Man 15 stated that irradiation of whole, fresh semen has little or no effect...
Ziller, Henry Hubert
Understanding the Irradiation Behavior of Zirconium Carbide
Zirconium carbide (ZrC) is being considered for utilization in high-temperature gas-cooled reactor fuels in deep-burn TRISO fuel. Zirconium carbide possesses a cubic B1-type crystal structure with a high melting point, exceptional hardness, and good thermal and electrical conductivities. The use of ZrC as part of the TRISO fuel requires a thorough understanding of its irradiation response. However, the radiation effects on ZrC are still poorly understood. The majority of the existing research is focused on the radiation damage phenomena at higher temperatures (>450{degree}C) where many fundamental aspects of defect production and kinetics cannot be easily distinguished. Little is known about basic defect formation, clustering, and evolution of ZrC under irradiation, although some atomistic simulation and phenomenological studies have been performed. Such detailed information is needed to construct a model describing the microstructural evolution in fast-neutron irradiated materials that will be of great technological importance for the development of ZrC- based fuel. The goal of the proposed project is to gain fundamental understanding of the radiation-induced defect formation in zirconium carbide and irradiation response (ZrC) by using a combination of state-of-the-art experimental methods and atomistic modeling. This project will combine (1) in situ ion irradiation at a specialized facility at a national laboratory, (2) controlled temperature proton irradiation on bulk samples, and (3) atomistic modeling to gain a fundamental understanding of defect formation in ZrC. The proposed project will cover the irradiation temperatures from cryogenic temperature to as high as 800{degree}C, and dose ranges from 0.1 to 100 dpa. The examination of this wide range of temperatures and doses allows us to obtain an experimental data set that can be effectively used to exercise and benchmark the computer calculations of defect properties. Combining the examination of radiation-induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.
Motta, Arthur; Sridharan, Kumar; Morgan, Dane; Szlufarska, Izabela
Climatology of Mid-latitude Ionospheric Disturbances from the Very Large Array Low-frequency Sky Survey
The results of a climatological study of ionospheric disturbances derived from observations of cosmic sources from the Very Large Array (VLA) Low-frequency Sky Survey (VLSS) are presented. We have used the ionospheric corrections applied to the 74 MHz interferometric data within the VLSS imaging process to obtain fluctuation spectra for the total electron content (TEC) gradient on spatial scales from a few to hundreds of kilometers and temporal scales from less than one minute to nearly an hour. The observations sample nearly all times of day and all seasons. They also span latitudes and longitudes from 28 deg. N to 40 deg. N and 95 deg. W to 114 deg. W, respectively. We have binned and averaged the fluctuation spectra according to time of day, season, and geomagnetic (Kp index) and solar (F10.7) activity. These spectra provide a detailed, multi-scale account of seasonal and intraday variations in ionospheric activity with wavelike structures detected at wavelengths between about 35 and 250 km. In some cases,...
Helmboldt, J F; Cotton, W D
Breaking the Crowther Limit: Combining Depth-Sectioning and Tilt Tomography for High-Resolution, Wide-Field 3D Reconstructions
To date, high-resolution ( 6 nm) to appear blurred or missing. Here we demonstrate a three-dimensional imaging method that overcomes both these limits by combining through-focal depth sectioning and traditional tilt-series tomography to reconstruct extended objects, with high-resolution, in all three dimensions. The large convergence angle in aberration corrected instruments now becomes a benefit and not a hindrance to higher quality reconstructions. A through-focal reconstruction over a 390 nm 3D carbon support containing over one hundred dealloyed and nanoporous PtCu catalyst particles revealed with sub-nanometer detail the extensive and connected interior pore structure that is created by the dealloying instability.
Hovden, Robert; Jiang, Yi; Wang, Deli; Yu, Yingchao; Abruna, Hector D; Elser, Veit; Muller, David A
Observational evidence for a changing tilt of the accretion disk with respect to the orbital plane in Her X-1 over its 35 day cycle
Analysis and interpretation of the Her X-1 X-ray light curve obtained with the ASM onbord RXTE over the period 1996 February to 2004 September is presented. We report that the features found previously in the averaged X-ray lightcurve are confirmed by the new RXTE/ASM data. In particular, anomalous dips and post-eclipse recoveries in two successive orbits in the short-on state are found to be prominent and stable details of the light curve. We argue that a change of the tilt of the accretion disk over the 35-day period is necessary to account for these features and show that our numerical model can explain such a behavior of the disk and reproduce the observed details of the light curve.
D. Klochkov; N. Shakura; K. Postnov; R. Staubert; J. Wilms; N. Ketsaris
Response of Strontium Titanate to Ion and Electron Irradiation...
Strontium Titanate to Ion and Electron Irradiation. Response of Strontium Titanate to Ion and Electron Irradiation. Abstract: Response of strontium titanate (SrTiO3) to ion and...
Irradiation Stability of Carbon Nanotubes and Related Materials
defect annealing at elevated irradiation temperatures, which delays the formation of amorphous regions. Investigation of nanotube stability after various processing techniques and irradiation indicated that radiation response of CNTs in a composite...
Aitkaliyeva, Assel 1985-
E-Print Network 3.0 - accelerated hyperfractionated irradiation...
Group Collection: Physics 79 Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet X-rays and 60 Summary: of 260 Mrad was used to irradiate Nd-Fe-B sample magnets with...
Implementation Plan for the Irradiated Materials Characterization Laboratory (IMCL)
This document contains details regarding the planned implementation of the Irradiated Materials Characterization Laboratory at the INL.
Not Listed
Effects of hadron irradiation on scintillating fibers
Trackers based on scintillating-fiber technology are being considered by the Solenoidal Detector Collaboration at SSC and the D[phi] collaboration at Fermilab. An important issue is the effect of the radiation existing in the detector cores on fiber properties. Most studies of radiation damage in scintillators have irradiated small bulk samples rather than fibers, and have used X-rays, [sup 60]Co gammas, or electron beams, often at accelerated rates. The authors have irradiated some 600 fibers in the Fermilab Tevatron C[phi] area, thereby obtaining a hadronic irradiation at realistic rates. Four-meter-long samples of ten Bicron polystyrene-based fiber types, maintained in air, dry nitrogen, argon, and vacuum atmospheres within stainless-steel tubes, were irradiated for seven weeks at various distances from the accelerator beam pipes. Maximum doses, measured by thermoluminescence detectors, were about 80 Krad. Fiber properties, particularly light yield and attenuation length, have been measured over a one-year period. A description of the work together with the results is presented. At the doses achieved, corresponding to a few years of actual fiber-tracking detector operation, little degradation is observed. In addition, recovery after several days' exposure to air has been noted. Properties of unirradiated samples kept in darkness show no changes after one year.
Atac, M. (Univ. of California, Los Angeles, CA (United States) Fermi National Accelerator Lab., Batavia, IL (United States)); Buchanan, C.; Chrisman, D.; Cline, D.; Kolonko, J.; Kubic, J.; Park, J. (Univ. of California, Los Angeles, CA (United States)); Baumbaugh, A.; Binkley, M.; Bross, A.D.; Finley, D.; Elias, J.; Foster, G.W.; Kephart, R.; Kephart, R.; Kim, C.; Park, H.; Pla-Dalmau, A.; Rivetta, C.; Tkaczyk, S.; Wagner, R. (Fermi National Accelerator Lab., Batavia, IL (United States)); Chung, M.; Goldberg, H.; Jeskik, R.; Margulies, S.; Mendez, H.; Solomon, J.; Vaca, F. (Univ. of Illinois, Chicago, IL (United States)); Kelley, C. (Massachusetts College of Pharmacy and Allied Health Sciences, Boston, MA (United States)); Baumbaugh, B.; Bishop, J.; Biswas, N.; Cason, N.; Jacques, J.; Kehoe, R.; Kelly, M.; Kenney, V.; LoSecco, J.; Ruchti, R.; Shephard, W.; Warchol, J.; Wayne, M.; Marchant, J.; Mountain, R.J. (Univ. of Notre Dame, IN (United States)); Davis, D.; Vandergriff, D. (O
SIPS: Solar Irradiance Prediction System Stefan Achleitner
-scaling capacities of renewable energy sources such as wind and solar. However, variability and uncertainty in powerSIPS: Solar Irradiance Prediction System Stefan Achleitner Computer Science and Engineering Liu and Alberto E. Cerpa Electrical Engineering and Computer Science University of California, Merced
Cerpa, Alberto E.
Continuous wave laser irradiation of explosives
Quantitative measurements of the levels of continuous wave (CW) laser light that can be safely applied to bare explosives during contact operations were obtained at 532 nm, 785 nm, and 1550 nm wavelengths. A thermal camera was used to record the temperature of explosive pressed pellets and single crystals while they were irradiated using a measured laser power and laser spot size. A visible light image of the sample surface was obtained before and after the laser irradiation. Laser irradiation thresholds were obtained for the onset of any visible change to the explosive sample and for the onset of any visible chemical reaction. Deflagration to detonation transitions were not observed using any of these CW laser wavelengths on single crystals or pressed pellets in the unconfined geometry tested. Except for the photochemistry of DAAF, TATB and PBX 9502, all reactions appeared to be thermal using a 532 nm wavelength laser. For a 1550 nm wavelength laser, no photochemistry was evident, but the laser power thresholds for thermal damage in some of the materials were significantly lower than for the 532 nm laser wavelength. No reactions were observed in any of the studied explosives using the available 300 mW laser at 785 nm wavelength. Tables of laser irradiance damage and reaction thresholds are presented for pressed pellets of PBX9501, PBX9502, Composition B, HMX, TATB, RDX, DAAF, PETN, and TNT and single crystals of RDX, HMX, and PETN for each of the laser wavelengths.
McGrane, Shawn D.; Moore, David S.
The Sun and Climate Solar Irradiance
The Sun and Climate #12;Solar Irradiance The Solar Constant f = 1.4 x 106 erg/cm2/s. Over is higher when the Sun is more magnetically active. ·The Sun was magnetically active, and the climate the Sun Drive Climate? #12;The Temperature's Rising #12;Sunspots and CO2 What is Cause and What is Effect
Walter, Frederick M.
Total Solar Irradiance Satellite Composites and their
Chapter 12 Total Solar Irradiance Satellite Composites and their Phenomenological Effect on Climate. Phenomenological solar signature on climate 310 9. Conclusion 312 1. INTRODUCTION A contiguoustotal solar from each other, in particular about whether the TSI minimum during solar Cycles 22e23 (1995
Scafetta, Nicola
Irradiation Embritlement in Alloy HT-�9
HT-9 steel is a candidate structural and cladding material for high temperature lead-bismuth cooled fast reactors. In typical advanced fast reactor designs fuel elements will be irradiated for an extended period of time, reaching up to 5-7 years. Significant displacement damage accumulation in the steel is expected (> 200 dpa) when exposed to dpa-rates of 20-30 dpa{sub Fe}/y and high fast flux (E > 0.1 MeV) {approx}4 x 10{sup 15} n/cm{sup 2}s. Core temperatures could reach 400-560 C, with coolant temperatures at the inlet as low as 250 C, depending on the reactor design. Mechanical behavior in the presence of an intense fast flux and high dose is a concern. In particular, low temperature operation could be limited by irradiation embrittlement. Creep and corrosion effects in liquid metal coolants could set a limit to the upper operating temperature. In this report, we focus on the low temperature operating window limit and describe HT-9 embrittlement experimental findings reported in the literature that could provide supporting information to facilitate the consideration of a Code Case on irradiation effects for this class of steels in fast reactor environments. HT-9 has an extensive database available on irradiation performance, which makes it the best choice as a possible near-term candidate for clad, and ducts in future fast reactors. Still, as it is shown in this report, embrittlement data for very low irradiation temperatures (< 200 C) and very high radiation exposure (> 150 dpa) is scarce. Experimental findings indicate a saturation of DBTT shifts as a function of dose, which could allow for long lifetime cladding operation. However, a strong increase in DBTT shift with decreasing irradiation temperature could compromise operation at low service temperatures. Development of a deep understanding of the physics involved in the radiation damage mechanisms, together with multiscale computer simulation models of irradiation embrittlement will provide the basis to derive trendlines and quantitative engineering predictions.
Serrano De Caro, Magdalena [Los Alamos National Laboratory
Response of neutron-irradiated RPV steels to thermal annealing
One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the fracture toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results of work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response of several irradiated RPV steels.
Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.
Total solar irradiance during the Holocene F. Steinhilber,1
Total solar irradiance during the Holocene F. Steinhilber,1 J. Beer,1 and C. Fro¨hlich2 Received 20 solar irradiance covering 9300 years is presented, which covers almost the entire Holocene. This reconstruction is based on a recently observationally derived relationship between total solar irradiance
Wehrli, Bernhard
Sensitivity of ultrasonic nonlinearity to irradiated, annealed, and re-irradiated microstructure changes in RPV steels
The planned life extension of nuclear reactors throughout the US and abroad will cause reactor vessel and internals materials to be exposed to more neutron irradiation than was originally intended. A nondestructive evaluation (NDE) method to monitor radiation damage would enable safe and cost-effective continued operation of nuclear reactors. Radiation damage in reactor pressure vessel (RPV) steels causes microstructural changes that leave the material in an embrittled state. Nonlinear ultrasound is an NDE technique quantified by the measurable acoustic nonlinearity parameter, which is sensitive to microstructural changes in metallic materials such as dislocations, precipitates and their combinations. Recent research has demonstrated the sensitivity of the acoustic nonlinearity parameter to increasing neutron fluence in representative RPV steels. The current work considers nonlinear ultrasonic experiments conducted on similar RPV steel samples that had a combination of irradiation, annealing, re-irradiation, and/or re-annealing to a total neutron fluence of 0.5 5 1019 n/cm2 (E > 1 MeV) at an irradiation temperature of 290 C. The acoustic nonlinearity parameter generally increased with increasing neutron fluence, and consistently decreased from the irradiated to the annealed state over different levels of neutron fluence. Results of the measured acoustic nonlinearity parameter are compared with those from previous measurements on other RPV steel samples. This comprehensive set of results illustrates the dependence of the measured acoustic nonlinearity parameter on neutron fluence, material composition, irradiation temperature and annealing.
Matlack, Katie [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Kim, J-Y. [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Wall, J.J. [Electric Power Research Institute (EPRI)] [Electric Power Research Institute (EPRI); Jacobs, L.J. [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Sokolov, Mikhail A [ORNL] [ORNL
Neogene Low-latitude Seasonal Environmental Variations: Stable Isotopic and Trace Elemental Records in Mollusks from the Florida Platform and the Central American Isthmus
Data View World Atlas 2001 database (Conkright et al., 2002) ................ 39 3-3 Temperature records from logger data from 4 m depth at Cayo Agua (Bocas del Toro) and 12 m depth at Pacheco (Gulf of Panama) watch station of Smithsonian... et al., 2001), sea level change (Haq et al., 1987), and fossil abundance (Allmon, 1993), etc. However, the tropical sea-surface temperature (SST) changes may differ from the global trend that is largely derived from high-latitudes. For example...
Tao, Kai
Effects of stress on microstructural evolution during irradiation
Many theories have been postulated to describe irradiation creep but few have been supported with microstructural evidence. The purpose of this paper is to review microstructural studies of the effects of stress during irradiation in order to assess the validity of the available irradiation creep theories. Microstructural studies based on high voltage electron, ion, proton and neutron irradiation will be described, with major emphasis placed on interpreting behavior demonstrated in austenitic steels. Special attention will be given to work on fast neutron irradiated Nimonic PE16, a precipitation strengthened superalloy.
Gelles, D.S. [Pacific Northwest Lab., Richland, VA (United States)
Materials Modification Under Ion Irradiation: JANNUS Project
JANNUS (Joint Accelerators for Nano-Science and Nuclear Simulation) is a project designed to study the modification of materials using multiple ion beams and in-situ TEM observation. It will be a unique facility in Europe for the study of irradiation effects, the simulation of material damage due to irradiation and in particular of combined effects. The project is also intended to bring together experimental and modelling teams for a mutual fertilisation of their activities. It will also contribute to the teaching of particle-matter interactions and their applications. JANNUS will be composed of three accelerators with a common experimental chamber and of two accelerators coupled to a 200 kV TEM.
Serruys, Y.; Trocellier, P. [CEA-Saclay, DEN/DMN/SRMP, 91191 Gif-sur-Yvette Cedex (France); Ruault, M.-O.; Henry, S.; Kaietasov, O. [CSNSM, Bat. 104, Orsay Campus (France); Trouslard, Ph. [INSTN, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France)
Neutron irradiation of beryllium: Recent Russian results
Results on postirradiation tensile and compression testing, swelling and bubble growth during annealing for various grades of beryllium are presented. It is shown that swelling at temperatures above 550{degrees}C is sensitive to material condition and response is correlated with oxygen content. Swelling on the order of 15% can be expected at 700{degrees}C for doses on the order of 10{sup 22} n/cm{sup 2}. Bubble growth response depends on irradiation fluence.
ARM - Measurement - Shortwave broadband total net irradiance
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 JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARMnumberDoppler ARMdiffusedirectnet irradiance
ARM - Measurement - Shortwave narrowband direct downwelling irradiance
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 JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARMnumberDopplerdownwelling irradiance ARM Data
ARM - Measurement - Shortwave narrowband direct normal irradiance
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 JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARMnumberDopplerdownwelling irradiance ARM
Magnetic phase formation in irradiated austenitic alloys
Austenitic alloys are often observed to develop magnetic properties during irradiation, possibly associated with radiation-induced acceleration of the ferrite phase. Some of the parametric sensitivities of this phenomenon have been addressed using a series of alloys irradiated in the BOR-60 reactor at 593K. The rate of development of magnetic phase appears to be sensitive to alloy composition. To the first order, the largest sensitivities to accelerate ferrite formation, as explored in this experiment, are associated with silicon, carbon and manganese and chromium. Si, C, and Mn are thought to influence diffusion rates of point defects while Cr plays a prominent role in defining the chromium equivalent and therefore the amount of ferrite at equilibrium. Pre-irradiation cold working was found to accelerate ferrite formation, but it can play many roles including an effect on diffusion, but on the basis of these results the dominant role or roles of cold-work cannot be identified. Based on the data available, ferrite formation is most probably associated with diffusion.
Gussev, Maxim N [ORNL] [ORNL; Busby, Jeremy T [ORNL] [ORNL; Tan, Lizhen [ORNL] [ORNL; Garner, Francis A. [Radiation Effects Consulting, Richland, WA] [Radiation Effects Consulting, Richland, WA
Upgrade to the Birmingham Irradiation Facility
The Birmingham Irradiation Facility was developed in 2013 at the University of Birmingham using the Medical Physics MC40 cyclotron. It can achieve High Luminosity LHC (HL-LHC) fluences of 10^15 (1 MeV neutron equivalent (neq)) cm^-2 in 80 s with proton beam currents of 1 ?A and so can evaluate effectively the performance and durability of detector technologies and new components to be used for the HL-LHC. Irradiations of silicon sensors and passive materials can be carried out in a temperature controlled cold box which moves continuously through the homogenous beamspot. This movement is provided by a pre-configured XY-axis Cartesian robot scanning system. In 2014 the cooling system and cold box were upgraded from a recirculating glycol chiller system to a liquid nitrogen evaporative system. The new cooling system achieves a stable temperature of 50 1C in 30 min and aims to maintain sub-0 1C temperatures on the sensors during irradiations. This paper reviews the design, development, commissioning and perform...
Dervan, P; Hodgson, P; Marin- Reyes; Parker, K; Wilson, J; Baca, M
Irradiation response and stability of nanoporous materials
Nanoporous materials consist of a regular organic or inorganic framework supporting a regular, porous structure. Pores are by definition roughly in the nanometre range, that is between 0.2 nm and 100 nm. Nanoporous materials can be subdivided into 3 categories (IUPAC): (1) Microporous materials - 0.2-2 nm; (2) Mesoporous materials - 2-50 nm; and (3) Macroporous materials - 50-1000 nm. np-Au foams were successfully synthesized by de-alloying process. np-Au foams remain porous structure after Ne ion irradiation to 1 dpa. Stacking Fault Tetrahedra (SFTs) were observed in RT irradiated np-Au foams under the highest and intermediate fluxes, but not under the lowest flux. SFTs were not observed in LNT irradiated np-Au foams under all fluxes. The vacancy diffusivity in Au at RT is high enough so that the vacancies have enough time to agglomerate and then collapse to form SFTs. The high ion flux creates more damage per unit time; vacancies don't have enough time to diffuse or recombine. As a result, SFTs were formed at high ion fluxes.
Fu, Engang [Los Alamos National Laboratory; Wang, Yongqiang [Los Alamos National Laboratory; Serrano De Caro, Magdalena [Los Alamos National Laboratory; Caro, Jose A. [Los Alamos National Laboratory; Zepeda-Ruiz, L [Lawrence Livermore national Laboratory; Bringa, E. [CONICET, Universidad de Cuyo, Argentina; Nastasi, Mike [University of Nebraska, Lincoln, NE; Baldwin, Jon K. [Los Alamos National Laboratory
The spectral irradiance traceability chain at PTB
Spectral irradiance is a fundamental radiometric unit. Its application to measurement results requires qualified traceability to basic units of the international system of units (Systeme international d'unites, SI). The Physikalisch-Technische Bundesanstalt (PTB) is amongst other national metrological institutes (NMIs) responsible for the realization, maintenance and dissemination of various radiometric and photometric units based on and traceable to national standards. The unit of spectral irradiance is realized and represented by a blackbody-radiator as the national primary standard of the PTB. Based on Planck's radiation law, the irradiance is calculated and realized for any wavelength taking into account the exact knowledge of the radiation temperature and the geometrical parameters. Using a double-monochromator-based spectroradiometer system, secondary standard lamps can be calibrated by direct comparison to the blackbody-radiator (substitution method). These secondary standard lamps are then used at the PTB to calibrate standard lamps of customers. The customers themselves use these so-called transfer standards to calibrate their working standard lamps. These working standards are then used to calibrate own spectroradiometers or sources. This rather complex calibration chain is a common procedural method that for the customers generally leads to satisfying measurement results on site. Nevertheless, the standard lamps in use have to fulfill highest requirements concerning stability and reproducibility. Only this allows achieving comparably low transfer measurement uncertainties, which occur at each calibration step. Thus, the PTB is constantly investigating the improvement and further development of transfer standards and measurement methods for various spectral regions. The realization and dissemination of the spectral irradiance using the blackbody-radiator at the PTB is accomplished with worldwide approved minimized measurement uncertainties confirmed by international intercomparisons among NMIs. Ultimately, the spectral irradiance can be realized with expanded measurement uncertainties of far less than 1 % over a wide spectral range. Thus, for customers with high demands on low measurement uncertainties, it is possible to calibrate their working standards directly against the blackbody-radiator, taking into account the higher necessary effort. In special cases it is possible to calibrate the customer's spectroradiometric facilities directly in front of the blackbody-radiator. In the context of the European Metrology Research Project Traceability for surface spectral solar ultraviolet radiation, the traceability chain will be improved and adapted.
Sperfeld, P.; Pape, S.; Nevas, S. [Physikalisch-Technische Bundesanstalt, Bundesallee 10, 381160 Braunschweig (Germany)
Evaluation of Neutron Irradiated Silicon Carbide and Silicon Carbide Composites
The effects of fast neutron irradiation on SiC and SiC composites have been studied. The materials used were chemical vapor deposition (CVD) SiC and SiC/SiC composites reinforced with either Hi-Nicalon{trademark} Type-S, Hi-Nicalon{trademark} or Sylramic{trademark} fibers fabricated by chemical vapor infiltration. Statistically significant numbers of flexural samples were irradiated up to 4.6 x 10{sup 25} n/m{sup 2} (E>0.1 MeV) at 300, 500 and 800 C in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Dimensions and weights of the flexural bars were measured before and after the neutron irradiation. Mechanical properties were evaluated by four point flexural testing. Volume increase was seen for all bend bars following neutron irradiation. Magnitude of swelling depended on irradiation temperature and material, while it was nearly independent of irradiation fluence over the fluence range studied. Flexural strength of CVD SiC increased following irradiation depending on irradiation temperature. Over the temperature range studied, no significant degradation in mechanical properties was seen for composites fabricated with Hi-Nicalon{trademark} Type-S, while composites reinforced with Hi-Nicalon{trademark} or Sylramic fibers showed significant degradation. The effects of irradiation on the Weibull failure statistics are also presented suggesting a reduction in the Weibull modulus upon irradiation. The cause of this potential reduction is not known.
Newsome G, Snead L, Hinoki T, Katoh Y, Peters D
The qWR star HD 45166. II. Fundamental stellar parameters and evidence of a latitude-dependent wind
The enigmatic object HD 45166 is a qWR star in a binary system with an orbital period of 1.596 day, and presents a rich emission-line spectrum in addition to absorption lines from the companion star (B7 V). As the system inclination is very small (i=0.77 +- 0.09 deg), HD 45166 is an ideal laboratory for wind-structure studies. The goal of the present paper is to determine the fundamental stellar and wind parameters of the qWR star. A radiative transfer model for the wind and photosphere of the qWR star was calculated using the non-LTE code CMFGEN. The wind asymmetry was also analyzed using a recently-developed version of CMFGEN to compute the emerging spectrum in two-dimensional geometry. The temporal-variance spectrum (TVS) was calculated for studying the line-profile variations. Abundances, stellar and wind parameters of the qWR star were obtained. The qWR star has an effective temperature of Teff=50000 +- 2000 K, a luminosity of log(L/Lsun)=3.75 +- 0.08, and a corresponding photospheric radius of Rphot=1.00 Rsun. The star is helium-rich (N(H)/N(He) = 2.0), while the CNO abundances are anomalous when compared either to solar values, to planetary nebulae, or to WR stars. The mass-loss rate is Mdot = 2.2 . 10^{-7} Msun/yr, and the wind terminal velocity is vinf=425 km/s. The comparison between the observed line profiles and models computed under different latitude-dependent wind densities strongly suggests the presence of an oblate wind density enhancement, with a density contrast of at least 8:1 from equator to pole. If a high velocity polar wind is present (~1200 km/s), the minimum density contrast is reduced to 4:1. The wind parameters determined are unusual when compared to O-type stars or to typical WR stars. (abridged)
J. H. Groh; A. S. Oliveira; J. E. Steiner
Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation
Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation Wilfred Edwin Booij Gonville and Caius College Cambridge A dissertation submitted for the degree of Doctor of Philosophy at the University of Cambridge December 1997... Summary Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation The irradiation of high Tc superconducting thin films with a focused electron beam, such as that obtained in a scanning transmission electron microscope (STEM), can...
Booij, Wilfred Edwin
Energetic ion bombardment can lead to the development of complex and diverse nanostructures on or beneath the material surface through induced self-organization processes. These self-organized structures have received particular interest recently as promising candidates as simple, inexpensive, and large area patterns, whose optical, electronic and magnetic properties are different from those in the bulk materials [1-5]. Compared to the low mass efficiency production rate of lithographic methods, these self-organized approaches display new routes for the fabrication of nanostructures over large areas in a short processing time at the nanoscale, beyond the limits of lithography [1,4]. Although it is believed that surface nanostructure formation is based on the morphological instability of the sputtered surface, driven by a kinetic balance between roughening and smoothing actions [6,7], the fundamental mechanisms and experimental conditions for the formation of these nanostructures has still not been well established, the formation of the 3-D naopatterns beneath the irradiated surface especially needs more exploration. During the last funding period, we have focused our efforts on irradiation-induced nanostructures in a broad range of materials. These structures have been studied primarily through in situ electron microscopy during electron or ion irradiation. In particular, we have performed studies on 3-D void/bubble lattices (in metals and CaF2), embedded sponge-like porous structure with uniform nanofibers in irradiated semiconductors (Ge, GaSb, and InSb), 2-D highly ordered pattern of nanodroplets (on the surface of GaAs), hexagonally ordered nanoholes (on the surface of Ge), and 1-D highly ordered ripple and periodic arrays (of Cu nanoparticles) [3,8-11]. The amazing common feature in those nanopatterns is the uniformity of the size of nanoelements (nanoripples, nanodots, nanovoids or nanofibers) and the distance separating them. Our research focuses on the understanding of fundamental scientific basis for the irradiation-induced self-organization processes. The fundamental physical mechanisms underlying ordered pattern formation, which include defect production and migration, ion sputtering, redeposition, viscous flow and diffusion, are investigated through a combination of modeling and in situ and ex-situ observations [3,9,11]. In addition, these nanostructured materials exhibit considerable improvement of optical properties [9,12,13]. For example, patterned Ge with a hexagonally ordered, honeycomb-like structure of nanoscale holes possesses a high surface area and a considerably blue-shifted energy gap [9], and oxidation of ordered Ga droplets shows noticeable enhancement of optical transmission [12]. This research has addressed nanopattern formation in a variety of materials under ion bombardment and provided a fundamental understanding of the dynamic mechanisms involved. In addition, have also stared to systematically investigate pattern formation under ion irradiation for more systems with varied experimental conditions and computation, including the collaboration with Dr. Veena Tikare of Sandia National Laboratory with a hybrid computation method at the ending this grant. A more detailed relationship between nanostructure formation and experimental conditions will be revealed with our continued efforts.
Wang, Lumin [Regents of the University of Michigan; Lu, Wei [Regents of the University of Michigan
A Simplified Shuttle Irradiation Facility for ATR
During the past fifteen years there has been a steady increase in the demand for radioisotopes in nuclear medicine and a corresponding decline in the number of reactors within the U.S. capable of producing them. The Advanced Test Reactor (ATR) is the largest operating test reactor in the U.S., but its isotope production capabilities have been limited by the lack of an installed isotope shuttle irradiation system. A concept for a simple �low cost� shuttle irradiation facility for ATR has been developed. Costs were reduced (in comparison to previous ATR designs) by using a shielded trough of water installed in an occupiable cubicle as a shielding and contamination control barrier for the send and receive station. This shielding concept also allows all control valves to be operated by hand and thus the need for an automatic control system was eliminated. It was determined that 4 � 5 ft of water would be adequate to shield the isotopes of interest while shuttles are transferred to a small carrier. An additional feature of the current design is a non-isolatable by-pass line, which provides a minimum coolant flow to the test region regardless of which control valves are opened or closed. This by-pass line allows the shuttle facility to be operated without bringing reactor coolant water into the cubicle except for send and receive operations. The irradiation position selected for this concept is a 1.5 inch �B� hole (B-11). This position provides neutron fluxes of approximately: 1.6 x 1014 (<0.5 eV) and 4.0 x 1013 (>0.8 MeV) n/cm2*sec.
Palmer, Alma Joseph; Laflin, S. T.
Emulation of reactor irradiation damage using ion beams
The continued operation of existing light water nuclear reactors and the development of advanced nuclear reactor depend heavily on understanding how damage by radiation to levels degrades materials that serve as the structural components in reactor cores. The first high dose ion irradiation experiments on a ferritic-martensitic steel showing that ion irradiation closely emulates the full radiation damage microstructure created in-reactor are described. Ferritic-martensitic alloy HT9 (heat 84425) in the form of a hexagonal fuel bundle duct (ACO-3) accumulated 155 dpa at an average temperature of 443�C in the Fast Flux Test Facility (FFTF). Using invariance theory as a guide, irradiation of the same heat was conducted using self-ions (Fe++) at 5 MeV at a temperature of 460�C and to a dose of 188 displacements per atom. The void swelling was nearly identical between the two irradiations and the size and density of precipitates and loops following ion irradiation are within a factor of two of those for neutron irradiation. The level of agreement across all of the principal microstructure changes between ion and reactor irradiations establishes the capability of tailoring ion irradiations to emulate the reactor-irradiated microstructure.
G. S. Was; Z. Jiao; E. Beckett; A. M. Monterrosa; O. Anderoglu; B. H. Sencer; M. Hackett
apres irradiation globale: Topics by E-print Network
necessary for the evaluation of global irradiance on inclined surface which is needed for photovoltaic Boyer, Edmond 7 Caractristiques lectriques de diodes Au-Si(N) ralises aprs...
Microsoft Word - Analysis of Deformation Mode Changes in Irradiated...
steels); however, in many cases they may have a negative impact on material performance (hydrogen embrittlement of bcc-phase, etc.). Irradiation leads to defects accumulation,...
Irradiation Effects on Human Cortical Bone Fracture Behavior
Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic...
alpha particle irradiation: Topics by E-print Network
5 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...
alpha particles irradiation: Topics by E-print Network
alpha particle irradiated: Topics by E-print Network
apres irradiation alpha: Topics by E-print Network
Edmond 8 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...
Modification of Defect Structures in Graphene by Electron Irradiation...
Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations. Modification of Defect Structures in Graphene by Electron...
Dynamic Recovery in Silicate-Apatite Structures Under Irradiation...
Recovery in Silicate-Apatite Structures Under Irradiation and Implications for Long-Term Immobilization of Actinides. Dynamic Recovery in Silicate-Apatite Structures Under...
LANGEVIN DYNAMICS OF THE TWO STAGE MELTING TRANSITION OF VORTEX MATTER IN Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} IN THE PRESENCE OF STRAIGHT AND OF TILTED COLUMNAR DEFECTS
In this paper we use London Langevin molecular dynamics simulations to investigate the vortex matter melting transition in the highly anisotropic high-temperature superconductor material Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}#14; in the presence of low concentration of columnar defects (CDs). We reproduce with further details our previous results obtained by using Multilevel Monte Carlo simulations that showed that the melting of the nanocrystalline vortex matter occurs in two stages: a first stage melting into nanoliquid vortex matter and a second stage delocalization transition into a homogeneous liquid. Furthermore, we report on new dynamical measurements in the presence of a current that identifies clearly the irreversibility line and the second stage delocalization transition. In addition to CDs aligned along the c-axis we also simulate the case of tilted CDs which are aligned at an angle with respect to the applied magnetic field. Results for CDs tilted by 45{degree} with respect to c-axis show that the locations of the melting and delocalization transitions are not affected by the tilt when the ratio of flux lines to CDs remains constant. On the other hand we argue that some dynamical properties and in particular the position of the irreversibility line should be affected.
GOLDSCHMIDT, YADIN Y.; LIU, Jin-Tao
Microstructural examination of irradiated vanadium alloys
Microstructural examination results are reported for a V-5Cr-5Ti unirradiated control specimens of heat BL-63 following annealing at 1050{degrees}C, and V-4Cr-4Ti heat BL-47 irradiated in three conditions from the DHCE experiment: at 425{degrees}C to 31 dpa and 0.39 appm He/dpa, at 600{degrees}C to 18 dpa and 0.54 appm He/dpa and at 600{degrees}C to 18 dpa and 4.17 appm He/dpa.
Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States); Chung, H.M. [Argonne National Lab., IL (United States)
Mitigation of irradiation embrittlement by annealing
The main results of a complex investigation carried out in Russia of post irradiation annealing and reembrittlement of WWER-440 reactor pressure vessel materials are presented. The dependence of the Charpy transition temperature recovery on annealing temperature and fluence was established. Charpy specimens were reirradiated after annealing at 340, 380, 420, and 460 C. Experimental values of the Charpy transition temperature after reirradiation are compared to that predicted by three methods. At annealing temperatures equal to or above 420 C, results of the analysis indicate that, of the methods investigated, the lateral shift method gives the best result for estimating the transition temperature shift due to reirradiation.
Amayev, A.D.; Kryukov, A.M.; Levit, V.I.; Platonov, P.A.; Sokolov, M.A. [Kurchatov Inst., Moscow (Russian Federation)
Irradiation-induced effects of proton irradiation on zirconium carbides with different stoichiometries
Zirconium carbide (ZrC) is being considered for utilization in deep burn TRISO fuel particles for hightemperature, gas-cooled reactors. Zirconium carbide has a cubic B1 type crystal structure along with a very high melting point (3420 ?C), exceptional hardness and good thermal and electrical conductivities. Understanding the ZrC irradiation response is crucial for establishing ZrC as an alternative component in TRISO fuel. Until now, very few studies on irradiation effects on ZrC have been released and fundamental aspects of defect evolution and kinetics are not well understood although some atomistic simulations and phenomenological studies have been performed. This work was carried out to understand the damage evolution in float-zone refined ZrC with different stoichiometries. Proton irradiations at 800 ?C up to doses of 3 dpa were performed on ZrCx (where x ranges from 0.9 to 1.2) to investigate the damage evolution. The irradiation-induced defects, such as density of dislocation loops, at different stoichiometries and doses which were characterized by transmission electron microscopy (TEM) is presented and discussed.
Y. Huang; B.R. Maier; T.R. Allen
A Near-Infrared Photometric Study of the Low Latitude Globular Clusters Liller 1, Djorgovski 1, HP 1, and NGC 6528
Images recorded through J, H, Ks, 2.2 micron continuum, and 2.3 micron CO filters are used to investigate the stellar contents of the low Galactic latitude globular clusters NGC 6528, Liller 1, Djorgovski 1, and HP 1, as well as surrounding bulge fields. Metallicities are estimated for the latter three clusters by comparing the colors and CO indices of giant branch stars with those in other clusters and the bulge, while reddenings are estimated from the colors of bright bulge stars in the surrounding fields. In some cases the metallicities and reddenings are significantly different from previous estimates.
T. J. Davidge
Evolution of the nanostructure OF VVER-1000 RPV materials under neutron irradiation and post irradiation annealing
A high nickel VVER-1000 (15Kh2NMFAA) base metal (1.34 wt% Ni, 0.47% Mn, 0.29% Si and 0.05% Cu), and a high nickel (12Kh2N2MAA) weld metal (1.77 wt% Ni, 0.74% Mn, 0.26% Si and 0.07% Cu) have been characterized by atom probe tomography to determine the changes in the microstructure during neutron irradiation to high fluences. The base metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 14.9 x 10{sup 23} m{sup -2} (E > 0.5 MeV), and the weld metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 11.5 x 10{sup 23} m{sup -2} (E > 0.5 MeV). High number densities of 2-nm-diameter Ni-, Si- and Mn-enriched nanoclusters were found in the neutron irradiated base and weld metals. No significant copper enrichment was associated with these nanoclusters and no copper-enriched precipitates were observed. The number densities of these nanoclusters correlate with the shifts in the {Delta}T{sub 41 J} ductile-to-brittle transition temperature. These nanoclusters were present after a post irradiOffice of Science (US)C, but had dissolved into the matrix after 24 h at 450 C. Phosphorus, nickel, silicon and to a lesser extent manganese were found to be segregated to the dislocations.
Miller, Michael K [ORNL; Chernobaeva, A. A. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Shtrombakh, Ya. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Erak, D. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Zabusov, Oleg O. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Russell, Kaye F [ORNL; Nanstad, Randy K [ORNL
Dissolution of ordered precipitates under ion irradiation
The stability of the ordered {gamma}{prime} precipitates under 300-keV Ni{sup +} irradiation was investigated between room temperature and 623 K. The two competing mechanisms of destabilization by cascade producing irradiation, i.e. disordering and dissolution of the {gamma}{prime} precipitates in Nimonic PE16 alloy, has been studied separately by electron microscopy and field-ion microscopy with atom probe. At high temperatures, the precipitates are stable. At intermediate temperatures, the precipitates dissolve by ballistic mixing into the matrix, but the interface is restored by the radiation-enhanced atomic jumps. The order in the precipitates remains stable. At low temperatures, the precipitates are dissolved by atomic mixing. The dissolution proceeds in a diffusional manner with a diffusion coefficient normalized by the displacement rate D/K = 0.75 nm{sup 2}dpa{sup {minus}1}. The precipitates become disordered by a fluence of 0.1 dpa, whereas precipitate dissolution needs much higher fluences.
Camus, E.; Bourdeau, F.; Abromeit, C.; Wanderka, N.; Wollenberger, H. [Hahn-Meitner-Institut Berlin GmbH (Germany)
Phase transformations in neutron-irradiated Zircaloys
Microstructural evolution in Zircaloy-2 and -4 spent-fuel cladding specimens after approx.3 years of irradiation in commercial power reactors has been investigated by TEM and HVEM. Two kinds of precipitates induced by the fast-neutron irradiation in the reactors have been identified, i.e., Zr/sub 3/O and cubic-ZrO/sub 2/ particles approximately 2 to 10 nm in size. By means of a weak-beam dark-field ''2-1/2D-microscopy'' technique, the bulk nature of the precipitates and the surficial nature of artifact oxide and hydride phases could be discerned. The Zr(Fe/sub x/,Cr/sub 1-x/)/sub 2/ and Zr/sub 2/(Fe/sub x/,Ni/sub 1-x/) intermetallic precipitates normally present in the as-fabricated material virtually dissolved in the spent-fuel cladding specimens after a fast-neutron fluence of approx.4 x 10/sup 21/ ncm/sup -2/ in the power reactors. The observed radiation-induced phase transformations are compared with predictions based on the currently available understanding of the alloy characteristics. 29 refs.
Chung, H.M.
During the past fifteen years there has been a steady increase in the demand for radioisotopes in nuclear medicine and a corresponding decline in the number of reactors within the U.S. capable of producing them. The Advanced Test Reactor (ATR) is the largest operating test reactor in the U.S., but its isotope production capabilities have been limited by the lack of an installed isotope shuttle irradiation system. A concept for a simple "low cost" shuttle irradiation facility for ATR has been developed. Cost were reduced (in comparison to previous ATR designs) by using a shielded trough of water installed in an occupiable cubicle as a shielding and contamination control barrier for the send and receive station. This shielding concept also allows all control valves to be operated by hand and thus the need for an automatic control system was eliminated. It was determined that 4-5 ft of water would be adequate to shield the isotopes of interest while shuttles are transferred to a small carrier. An additional feature of the current design is a non-isolatable by-pass line, which provides a minimum coolant flow to the test region regardless of which control valves are opened or closed. This by-pass line allows the shuttle facility to be operated without bringing reactor coolant water into the cubicle except for send and receive operations.
A. J. Palmer; S. T. Laflin
Optimisation of buildings' solar irradiation availability
In order to improve the sustainability of new and existing urban settlements it is desirable to maximise the utilisation of the solar energy incident on the building envelope, whether by passive or active means. To this end we have coupled a multi-objective optimisation algorithm with the backwards ray tracing program RADIANCE which itself uses a cumulative sky model for the computation of incident irradiation (W h/m{sup 2}) in a single simulation. The parameters to optimise are geometric (the height of buildings up to their facade and the height and orientation of roofs), but with the constraint of maintaining an overall built volume, and the objective function is heating season solar irradiation offset by envelope heat losses. This methodology has been applied to a range of urban typologies and produces readily interpretable results. The focus of this work is on the design of new urban forms but the method could equally be applied to examine the relative efficiency of existing urban settlements, by comparison of existing forms with the calculated optima derived from relevant specifications of the building envelope. (author)
Kaempf, Jerome Henri; Montavon, Marylene; Bunyesc, Josep; Robinson, Darren [Solar Energy and Building Physics Laboratory, Station 18, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland); Bolliger, Raffaele [Industrial Energy Systems Laboratory, Station 9, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland)
LWRS ATR Irradiation Testing Readiness Status
The Light Water Reactor Sustainability (LWRS) Program was established by the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of the current reactors. The LWRS Program is divided into four R&D Pathways: (1) Materials Aging and Degradation; (2) Advanced Light Water Reactor Nuclear Fuels; (3) Advanced Instrumentation, Information and Control Systems; and (4) Risk-Informed Safety Margin Characterization. This report describes an irradiation testing readiness analysis in preparation of LWRS experiments for irradiation testing at the Idaho National Laboratory (INL) Advanced Test Reactor (ATR) under Pathway (2). The focus of the Advanced LWR Nuclear Fuels Pathway is to improve the scientific knowledge basis for understanding and predicting fundamental performance of advanced nuclear fuel and cladding in nuclear power plants during both nominal and off-nominal conditions. This information will be applied in the design and development of high-performance, high burn-up fuels with improved safety, cladding integrity, and improved nuclear fuel cycle economics
Kristine Barrett
Analysis of tritium transport in irradiated beryllium
Analysis of the beryllium tritium release results with simple analytical models indicated that tritium behavior in Be is not dominated by one simple mechanism, but by a combination of several mechanisms including surface processes and helium bubbles. A model was developed and the initial version of the model included tritium diffusion in the beryllium and the beryllium oxide, second order desorption at the solid/gas interface and diffusion through interconnected porosity. Fundamental data, tritium diffusion and desorption coefficients for Be and BeO, were derived from experimental data using the model. Beryllium is a metal to which one can generally apply the concepts of diffusion, solubility, surface processes and traps. Tritium transport in the irradiated beryllium is affected by processes occurring in the bulk, He bubbles, the bulk/surface and surface/gas interfaces. There are two types of solid/gas surfaces in the irradiated Be. One is the surface at the pure Be/He bubble interface where no oxide layer exists and the other is the surface at the BeO layer/purge gas interface. Although the material characteristics of the Be and BeO layer are different and have different activation barriers, the surface processes can be applied to both interfaces.
Cho, S.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States)
Postharvest irradiation treatment effect on grapefruit functional components and their role in prevention of colon cancer
and irradiation significantly (P ? 0.05) affected the bioactive compounds in grapefruit, however, the effect of storage was prominent. The third study examined the influence of irradiation and freeze drying on bioactive compounds of grapefruit. Irradiation...
Vanamala, Jairam Krishna Prasad
SHORT COMMUNICATION Microbeam irradiation of C. elegans nematode in microfluidic
SHORT COMMUNICATION Microbeam irradiation of C. elegans nematode in microfluidic channels M implemented a microfluidic tool for microbeam irradiation of Caenorhabditis elegans. The device allows into the microfluidic device through liquid flow between an inlet and an outlet, and the size of each microchannel
Brenner, David Jonathan
Retention of Hydrogen Isotopes in Neutron Irradiated Tungsten
To investigate the effects of neutron irradiation on hydrogen isotope retention in tungsten, disk-type specimens of pure tungsten were irradiated in the High Flux Isotope Reactor in Oak Ridge National Laboratory followed by exposure to high flux deuterium (D) plasma in Idaho National Laboratory. The results obtained for low dose n-irradiated specimens (0.025 dpa for tungsten) are reviewed in this paper. Irradiation at coolant temperature of the reactor (around 50 degrees C) resulted in the formation of strong trapping sites for D atoms. The concentrations of D in n-irradiated specimens were ranging from 0.1 to 0.4 mol% after exposure to D plasma at 200 and 500 degrees C and significantly higher than those in non-irradiated specimens because of D-trapping by radiation defects. Deep penetration of D up to a depth of 50-100 �m was observed at 500 degrees C. Release of D in subsequent thermal desorption measurements continued up to 900 degrees C. These results were compared with the behaviour of D in ion-irradiated tungsten, and distinctive features of n-irradiation were discussed.
Yuji Hatano; Masashi Shimada; Yasuhisa Oya; Guoping Cao; Makoto Kobayashi; Masanori Hara; Brad J. Merrill; Kenji Okuno; Mikhail A. Sokolov; Yutai Katoh
Irradiation effects in high-density polyethylene Jussi Polvia
Irradiation effects in high-density polyethylene Jussi Polvia , Kai Nordlunda a simulations, we have studied the irradiation effects in high density polyethylene. We determined the threshold energy for creating defects in the polyethylene lattice as a function of the incident angle. We found
Nordlund, Kai
Asymmetric Orientational Writing in glass with femtosecond laser irradiation
Asymmetric Orientational Writing in glass with femtosecond laser irradiation B. Poumellec,1 M in the dielectric inducing an asymmetric stress field is proposed. ©2013 Optical Society of America OCIS codes: (160. Prade, and A. Mysyrowicz, "Femtosecond laser irradiation stress induced in pure silica," Opt. Express 11
Physica B 308310 (2001) 612615 Irradiation effects in semiconducting diamonds
Physica B 308310 (2001) 612615 Irradiation effects in semiconducting diamonds N. Kristianpoller irradiation on semiconducting diamonds (type IIb) were studied and compared with those induced at the same conditions in natural (type Ia) and in synthetic diamonds. Methods of optical absorption, of X-ray and light
Chen, Reuven
SPECTRAL SOLAR IRRADIANCE AND ITS ENTROPIC EFFECT ON EARTH'S CLIMATE Wei Wu1 , Yangang Liu1 of the spectral solar irradiance (SSI) at the top of the Earth's atmosphere by the Solar Radiation and Climate's entropy flux from the TOA incident solar radiation. Two extreme cases are examined by using Planck
Standard Guide for Packaging Materials for Foods to Be Irradiated
1.1 This guide provides a format to assist producers and users of food packaging materials in selecting materials that have the desirable characteristics for their intended use and comply with applicable standards or government authorizations. It outlines parameters that should be considered when selecting food-contact packaging materials intended for use during irradiation of prepackaged foods and it examines the criteria for fitness for their use. 1.2 This guide identifies known regulations and regulatory frameworks worldwide pertaining to packaging materials for holding foods during irradiation; but it does not address all regulatory issues associated with the selection and use of packaging materials for foods to be irradiated. It is the responsibility of the user of this guide to determine the pertinent regulatory issues in each country where foods are to be irradiated and where irradiated foods are distributed. 1.3 This guide does not address all of the food safety issues associated with the synergisti...
American Society for Testing and Materials. Philadelphia
E-Print Network 3.0 - accelerated partial-breast irradiation...
irradiated for one hour... 1 Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet ... Source: Kemner, Ken - Biosciences Division, Argonne National Laboratory...
Instrumentation to Enhance Advanced Test Reactor Irradiations
The Department of Energy (DOE) designated the Advanced Test Reactor (ATR) as a National Scientific User Facility (NSUF) in April 2007 to support U.S. leadership in nuclear science and technology. By attracting new research users - universities, laboratories, and industry - the ATR will support basic and applied nuclear research and development, further advancing the nation's energy security needs. A key component of the ATR NSUF effort is to prove new in-pile instrumentation techniques that are capable of providing real-time measurements of key parameters during irradiation. To address this need, an assessment of instrumentation available and under-development at other test reactors has been completed. Based on this review, recommendations are made with respect to what instrumentation is needed at the ATR and a strategy has been developed for obtaining these sensors. Progress toward implementing this strategy is reported in this document. It is anticipated that this report will be updated on an annual basis.
J. L. Rempe; D. L. Knudson; K. G. Condie; J. E. Daw; S. C. Taylor
Irradiation behavior of metallic fast reactor fuels
Metallic fuels were the first fuels chosen for liquid metal cooled fast reactors (LMR's). In the late 1960's world-wide interest turned toward ceramic LMR fuels before the full potential of metallic fuel was realized. However, during the 1970's the performance limitations of metallic fuel were resolved in order to achieve a high plant factor at the Argonne National Laboratory's Experimental Breeder Reactor II. The 1980's spawned renewed interest in metallic fuel when the Integral Fast Reactor (IFR) concept emerged at Argonne National Laboratory. A fuel performance demonstration program was put into place to obtain the data needed for the eventual licensing of metallic fuel. This paper will summarize the results of the irradiation program carried out since 1985.
Pahl, R.G.; Porter, D.L.; Crawford, D.C.; Walters, L.C.
Optimization parameter design for proton irradiation accelerator
The proton irradiation accelerator is widely founded for industry application, and should be designed as compact, reliable, and easy operate. A 10 MeV proton beam is designed to be injected into the slow circulation ring with the repetition rate of 0.5 Hz for accumulation and acceleration, and then the beam with the energy of 300MeV will be slowly extracted by third order resonance method. For getting a higher intensity and more uniform beam, the height of the injection bump is carefully optimised during the injection period. Besides, in order to make the extracted beam with a more uniform distribution, a RF Knock-out method is adopted, and the RF kicker's amplitude is well optimised.
Yu-Wen An; Hong-Fei Ji; Sheng Wang; Shou-Yan Xu
Recovery of niobium from irradiated targets
A process for selective separation of niobium from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected form the group consisting of molybdenum, biobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the cationic resin; adjusting the pH of the second ion-containing solution to within a range of from about 5.0 to about 6.0; contacting the pH adjusting second ion-containing solution with a dextran-based material for a time to selectively separate niobium from the solution and recovering the niobium from the dextran-based material.
Phillips, Dennis R. (Los Alamos, NM); Jamriska, Sr., David J. (Los Alamos, NM); Hamilton, Virginia T. (Los Alamos, NM)
AGC-3 Irradiation Data Qualification Final Report
The Graphite Technology Development Program will run a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The third experiment, Advanced Graphite Creep 3 (AGC 3), began with Advanced Test Reactor (ATR) Cycle 152B on November 27, 2012, and ended with ATR Cycle 155B on April 23, 2014. This report documents qualification of AGC 3 experiment irradiation monitoring data for use by the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) Program for research and development activities required to design and license the first VHTR nuclear plant. Qualified data meet the requirements for data collection and use as described in the experiment planning and quality assurance documents. Failed data do not meet the requirements. Trend data may not meet the requirements, but may still provide some useable information. All thermocouples (TCs) functioned throughout the AGC 3 experiment. There was one interval between December 18, 2012, and December 20, 2012, where 10 NULL values were reported for various TCs. These NULL values were deleted from the Nuclear Data Management and Analysis System database. All temperature data are Qualified for use by the VHTR TDO Program. Argon, helium, and total gas flow data were within expected ranges and are Qualified for use by the VHTR TDO Program. Total gas flow was approximately 50 sccm through the AGC 3 experiment capsule. Helium gas flow was briefly increased to 100 sccm during ATR shutdowns. At the start of the AGC 3 experiment, moisture in the outflow gas line was stuck at a constant value of 335.6174 ppmv for the first cycle (Cycle 152B). When the AGC 3 experiment capsule was reinstalled in ATR for Cycle 154B, a new moisture filter was installed. Moisture data from Cycle 152B are Failed. All moisture data from the final three cycles (Cycles 154B, 155A, and 155B) are Qualified for use by the VHTR TDO Program.
Laurence Hull
BEAM TILTED CORRELATIONS Frank Vignola
from the modules, module temperature, ambient temperature, wind speed, incident solar radiation under standardized operation conditions (25 Celsius and 1000 watts/meter2 incident solar radiation and comprehensive solar radiation data. Specifically, these models were designed to use the National Solar Radiation
Oregon, University of
Indoor and Outdoor Spectroradiometer Intercomparison for Spectral Irradiance Measurement
This report details the global spectral irradiance intercomparison using spectroradiometers that was organized by the National Renewable Energy Laboratory's Solar Radiation Research Laboratory. The intercomparison was performed both indoors and outdoors on September 17, 2013. Five laboratories participated in the intercomparison using 10 spectroradiometers, and a coordinated measurement setup and a common platform were employed to compare spectral irradiances under both indoor and outdoor conditions. The intercomparison aimed to understand the performance of the different spectroradiometers and to share knowledge in making spectral irradiance measurements. This intercomparison was the first of its kind in the United States.
Habte, A.; Andreas, A.; Ottoson, L.; Gueymard, C.; Fedor, G.; Fowler, S.; Peterson, J.; Naranen, R.; Kobashi, T.; Akiyama, A.; Takagi, S.
Gamma irradiation effects on the biodegradation of lignin
parts: biological utilization of irradiated Calcium Lignosulphonate (CLS) and irradiation effects on the composition of CLS. The CLS used in this study was a commercially available lignin compound which is produced by flash evaporation of spent... 4/ X / 2. 0 3. 0 4. 0 5. 0 6. 0 7. 0 Wavelength in microns 8. 0 9. 0 28 CHAPTER VI RESULTS AND CONCLUSIONS A commercia I CLS was irradiated in a dry state to various total dose levels of Co-60 gamma rays. The effects on the structure...
Krysinski, Thomas Leon
Electron Beam Irradiation for Improving Safety of Fruits and Vegetables
. An alternative may be irradiation which is emerging as a promising tool to enhance safety and extend shelf life of fresh and fresh cut produce. Gamma rays have been the most extensively studied form of irradiation and have been successfully applied to spices..., tubers, grains and meat products for the space program. However, consumer reluctance has limited its application over a broad range of food stuffs. As a result, alternate irradiation technologies such as e-beam and X-rays are attracting attention...
Adavi, Megha Sarthak
Pyrolytic carbon free-radical evolution and irradiation damage of polyimide under low-energy proton irradiation
Ionization and displacement effects are basic phenomena in damage processes of materials under space-particle irradiation. In this paper, the damage behaviors were investigated on the polyimide under proton irradiation using electron paramagnetic resonance (EPR) spectra analysis and optical absorbance valuation. The results indicate that the proton irradiation induces the formation of pyrolytic carbon free-radical with a g value of 2.0025, and the population of free radicals increases with the irradiation fluence. The most important finding is that the irradiation-induced free-radical population increases linearly with the displacement damage dose, as does the optical degradation, whereas the ionization effect alone, during the irradiation, cannot induce the formation of pyrolytic carbon free radical. Furthermore, during the post storage, after irradiation, the free-radical population decreases following a sum of an exponential and a linear mode with the storage time. It is interesting that, during the post storage, the recovery of the degraded optical absorbance of the polyimide follows a similar mode to that of free radicals, and the characteristic time constant changes with the wavelength of the optical spectra.
Sun Chengyue; Wu Yiyong; Xiao Jingdong; Li Ruifeng; Yang Dezhuang; He Shiyu [National Key Lab in Materials Behaviors and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin 150001 (China)
AGC-2 Irradiation Data Qualification Final Report
The Graphite Technology Development Program will run a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The second Advanced Graphite Creep (AGC) experiment (AGC-2) began with Advanced Test Reactor (ATR) Cycle 149A on April 12, 2011, and ended with ATR Cycle 151B on May 5, 2012. The purpose of this report is to qualify AGC-2 irradiation monitoring data following INL Management and Control Procedure 2691, Data Qualification. Data that are Qualified meet the requirements for data collection and use as described in the experiment planning and quality assurance documents. Data that do not meet the requirements are Failed. Some data may not quite meet the requirements, but may still provide some useable information. These data are labeled as Trend. No Trend data were identified for the AGC-2 experiment. All thermocouples functioned throughout the AGC-2 experiment. There was one instance where spurious signals or instrument power interruption resulted in a recorded temperature value being well outside physical reality. This value was identified and labeled as Failed data. All other temperature data are Qualified. All helium and argon gas flow data are within expected ranges. Total gas flow was approximately 50 sccm through the capsule. Helium gas flow was briefly increased to 100 sccm during reactor shutdown. All gas flow data are Qualified. At the start of the experiment, moisture in the outflow gas line increased to 200 ppmv then declined to less than 10 ppmv over a period of 5 days. This increase in moisture coincides with the initial heating of the experiment and drying of the system. Moisture slightly exceeded 10 ppmv three other times during the experiment. While these moisture values exceed the 10 ppmv threshold value, the reported measurements are considered accurate and to reflect moisture conditions in the capsule. All moisture data are Qualified. Graphite creep specimens are subjected to one of three loads, 393 lbf, 491 lbf, or 589 lbf. Loads were consistently within 5% of the specified values throughout the experiment. Stack displacement increased consistently throughout the experiment with total displacement ranging from 1 to 1.5 inches. No anomalous values were identified. During reactor outages, a set of pneumatic rams are used to raise the stacks of graphite creep specimens to ensure the specimens have not become stuck within the test train. This stack raising was performed after all cycles when the capsule was in the reactor. All stacks were raised successfully after each cycle. The load and displacement data are Qualified
Laurence C. Hull
The modelling of irradiation-enhanced phosphorus segregation in neutron irradiated reactor pressure vessel submerged-arc welds
Recent results on neutron-irradiated RPV submerged-arc welds have revealed grain boundary segregation of phosphorus during irradiation, which may lead to intergranular fracture. However, the experimental database is insufficient to define the dependence of the process on variables such ad dose, dose-rate and temperature. This paper describes work in which two existing models of phosphorus segregation, under thermal or irradiation conditions, have been developed to obtain predictions of these dependencies. The critical parameters in the models have been adjusted to give consistency with the available reference data, and predictions have been made of the dependence of segregation on a number of variables.
Druce, S.G.; English, C.A.; Foreman, A.J.E.; McElroy, R.J.; Vatter, I.A. [AEA Technology, Didcot (United Kingdom). Harwell Lab.; Bolton, C.J.; Buswell, J.T.; Jones, R.B. [Nuclear Electric, Berkeley (United Kingdom). Berkeley Technology Centre
Solar irradiance forecasting at multiple time horizons and novel methods to evaluate uncertainty
Solar irradiance data . . . . . . . . . . . . .Accuracy . . . . . . . . . . . . . . . . . Solar Resourcev Uncertainty In Solar Resource: Forecasting
Marquez, Ricardo
K.K. Gan ATLAS Tracker Upgrade Workshop 1 Irradiation Results and Transmission on
Power vs Dosage all VCSELs still produce optical power at SLHC dosage should irradiate at lower Workshop 14 Post-Irradiation Analysis all arrays except ULM 5 G still produce optical power post-irradiationK.K. Gan ATLAS Tracker Upgrade Workshop 1 Irradiation Results and Transmission on Small Cables
Gan, K. K.
agr-1 irradiation experiment: Topics by E-print Network
E. Schwartz Department Direct-normal solar irradiance (DNSI), the total energy in the solar spectrum incident in unit time Schwartz, Stephen E. 13 An Experiment at HiRadMat:...
Review of Dynamic Recovery Effects on Ion Irradiation Damage...
6H�SiC, ionization processes are less dominant. Citation: Weber WJ, Y Zhang, and LM Wang.2012."Review of Dynamic Recovery Effects on Ion Irradiation Damage in...
Materials for cold neutron sources: Cryogenic and irradiation effects
Materials for the construction of cold neutron sources must satisfy a range of demands. The cryogenic temperature and irradiation create a severe environment. Candidate materials are identified and existing cold sources are briefly surveyed to determine which materials may be used. Aluminum- and magnesium-based alloys are the preferred materials. Existing data for the effects of cryogenic temperature and near-ambient irradiation on the mechanical properties of these alloys are briefly reviewed, and the very limited information on the effects of cryogenic irradiation are outlined. Generating mechanical property data under cold source operating conditions is a daunting prospect. It is clear that the cold source material will be degraded by neutron irradiation, and so the cold source must be designed as a brittle vessel. The continued effective operation of many different cold sources at a number of reactors makes it clear that this can be accomplished. 46 refs., 8 figs., 2 tab.
Alexander, D.J.
Irradiation facilities at the Los Alamos Meson Physics Facility
The irradiation facilities for testing SSC components and detector systems are described. Very high intensity proton, neutron, and pion fluxes are available with beam kinetic energies of up to 800 MeV. 4 refs., 12 figs., 2 tabs.
Sandberg, V.
Sandis irradiator for dried sewage solids. Final safety analysis report
Analyses of the hazards associated with the operation of the Sandia irradiator for dried sewage solids, as well as methods and design considerations to minimize these hazards, are presented in accordance with DOE directives.
Morris, M.
Microstructural and Mechanical Property Changes in Ion Irradiated Tunsgten
on the sustainability of tungsten as a plasma facing material (PFM). During operation, PFM must withstand harsh conditions with combined effects from high temperature, mechanical stress, irradiation, transmutation, and the production of hydrogen (H) and helium (He...
General, Michael
Post-irradiation Examination and Fission Product Inventory Analysis of AGR-1 Irradiation Capsules
The AGR-1 experiment was the first in a series of Advanced Gas Reactor (AGR) experiments designed to test TRISO fuel under High Temperature Gas Reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post-irradiation examination (PIE) at INL�s Materials and Fuels Complex (MFC). The inventory and distribution of fission products, especially Ag-110m, was assessed and analyzed for all the components of the AGR-1 capsules. This data should help inform the study of fission product migration in coated particle fuel. Gamma spectrometry was used to measure the activity of various different fission products in the different components of the AGR-1 test train. Each capsule contained: 12 fuel compacts, a graphite holder that kept the fuel compacts in place, graphite spacers that were above and below the graphite holders and fuel compacts, gas lines through which a helium neon gas mixture flowed in and out of each capsule, and the stainless steel shell that contained the experiment. Gamma spectrometry results and the experimental techniques used to capture these results will be presented for all the capsule components. The components were assayed to determine the total activity of different fission products present in or on them. These totals are compared to the total expected activity of a particular fission product in the capsule based on predictions from physics simulation. Based on this metric, a significant fraction of the Ag-110m was detected outside the fuel compacts, but the amount varied highly between the 6 capsules. Very small fractions of Cs-137 (<2E-5), Cs-134 (<1e-5), and Eu-154 (<4e-4) were detected outside of the fuel compacts. Additionally, the distribution of select fission products in some of the components including the fuel compacts and the graphite holders were measured and will be discussed.
J M Harp; P D Demkowicz; S A Ploger
Irradiation Assisted Grain Boundary Segregation in Steels
The understanding of radiation-induced grain boundary segregation (RIS) has considerably improved over the past decade. New models have been introduced and much effort has been devoted to obtaining comprehensive information on segregation from the literature. Analytical techniques have also improved so that chemical analysis of layers 1 nm thick is almost routine. This invited paper will review the major methods used currently for RIS prediction: namely, Rate Theory, Inverse Kirkendall, and Solute Drag approaches. A summary is made of the available data on phosphorus RIS in reactor pressure vessel (RPV) steels. This will be discussed in the light of the predictions of the various models in an effort to show which models are the most reliable and easy to use for forecasting P segregation behaviour in steels. A consequence of RIS in RPV steels is a radiation induced shift in the ductile to brittle transition temperature (DBTT). It will be shown how it is possible to relate radiation-induced P segregation levels to DBTT shift. Examples of this exercise will be given for RPV steels and for ferritic steels being considered for first wall fusion applications. Cr RIS in high alloy stainless steels and associated irradiation-assisted stress corrosion cracking (IASCC) will be briefly discussed. (authors)
Lu, Zheng; Faulkner, Roy G. [IPTME, Loughborough University, Loughborough, Leics (United Kingdom)
Recovery of germanium-68 from irradiated targets
A process for selective separation of germanium-68 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, adjusting the pH of the second ion-containing solution to within a range of from about 0.7 to about 3.0, adjusting the soluble metal halide concentration in the second ion-containing solution to a level adapted for subsequent separation of germanium, contacting the pH-adjusted, soluble metal halide-containing second ion-containing solution with a dextran-based material whereby germanium ions are separated by the dextran-based material, and recovering the germanium from the dextran-based material, preferably by distillation.
Ion irradiation induced effects in polyamidoimide
The interaction between ion beam and polyamidoimide (PAI) is studied by means of low-temperature infrared spectroscopy. 200 keV Ar{sup +} and 250 keV He{sup +} beams with fluences ranging from 10{sup 13} ions cm{sup {minus}2} to 5{times}10{sup 16} ions cm{sup {minus}2} are found to induce atomic bond breaks leading to absorption bands at 2344, 2261, and 2125 cm{sup {minus}1} corresponding respectively to CO{sub 2}, C=N=N and C=N--R vibrations. Shrinkage of the polymer along with a drastic decrease of the resistivity during Ar{sup +} and He{sup +} irradiation are observed. Speculations on the respective role of electronic processes and atomic collisions in the evolution of the polymer are made. No evidence of PAI modification through knock-on mechanism for fluences lower than 5{times}10{sup 15} ions cm{sup {minus}2} is noticed. In fact, our results would suggest a predominant role of the electronic processes for the low fluences (up to 5{times}10{sup 15} ions cm{sup {minus}2} ), whereas a degradation mechanism based on atomic collisions is more likely to take place for higher fluences. A theoretical mechanism of reactions based upon our Fourier transform infrared (FTIR) and secondary ion mass spectroscopies (SIMS) results, describing the chemical changes occurring in the PAI, is presented and briefly discussed.
Merhari, L.; Belorgeot, C.; Moliton, J.P. (Laboratoire d'Electronique des Polymeres sous Faisceaux Ioniques 123, avenue Albert Thomas, 87060 Limoges Cedex (France))
Use of laser extensometer for mechanical test on irradiated materials
Techniques have been developed by EDF`s hot laboratory in Chinon for performing mechanical tests on irradiated materials. Some of these techniques aim to facilitate strain measurements, which are particularly difficult to perform on irradiated specimens at high temperatures or on subsize specimens. Recent progress has been driven by laser technology combined with software development. The use of this technique, which allows strain measurements without contact on the specimen, is described for tensile (especially on subsize specimens), fatigue and creep tests.
Brillaud, C.; Meylogan, T.; Salathe, P. [Electricite de France, Avoine (France)
In April 2007, the Department of Energy (DOE) designated the Advanced Test Reactor (ATR) a National Scientific User Facility (NSUF) to advance US leadership in nuclear science and technology. By attracting new users from universities, laboratories, and industry, the ATR will support basic and applied nuclear research and development and help address the nation's energy security needs. In support of this new program, the Idaho National Laboratory (INL) has developed in-house capabilities to fabricate, test, and qualify new and enhanced temperature sensors for irradiation testing. Although most efforts emphasize sensors capable of providing real-time data, selected tasks have been completed to enhance sensors provided in irradiation locations where instrumentation leads cannot be included, such as drop-in capsule and Hydraulic Shuttle Irradiation System (HSIS) or 'rabbit' locations. For example, silicon carbide (SiC) monitors are now available to detect peak irradiation temperatures between 200�C and 800�C. Using a resistance measurement approach, specialized equipment installed at INL's High Temperature Test Laboratory (HTTL) and specialized procedures were developed to ensure that accurate peak irradiation temperature measurements are inferred from SiC monitors irradiated at the ATR. Comparison examinations were completed by INL to demonstrate this capability, and several programs currently rely on SiC monitors for peak temperature detection. This paper discusses the use of SiC monitors at the ATR, the process used to evaluate them at the HTTL, and presents representative measurements taken using SiC monitors.
K. L. Davis; B. Chase; T. Unruh; D. Knudson; J. L. Rempe
Comparison of /sup 32/P therapy and sequential hemibody irradiation (HBI) for bony metastases as methods of whole body irradiation
We report a retrospective study of 15 patients with prostate carcinoma and diffuse bone metastases treated with sodium /sup 32/P for palliation of pain at Downstate Medical Center and Kings County Hospital from 1973 to 1978. The response rates, duration of response, and toxicities are compared with those of other series of patients treated with /sup 32/P and with sequential hemibody irradiation. The response rates and duration of response are similar with both modalities ranging from 58 to 95% with a duration of 3.3 to 6 months with /sup 32/P and from 75 to 86% with a median duration of 5.5 months with hemibody irradiation. There are significant differences in the patterns of response and in the toxicities of the two treatment methods. Both methods cause significant bone marrow depression. Acute radiation syndrome, radiation pneumonitis, and alopecia are seen with sequential hemibody irradiation and not with /sup 32/P, but their incidence can be reduced by careful treatment planning. Hemibody irradiation can provide pain relief within 24 to 48 h, while /sup 32/P may produce an initial exacerbation of pain. Lower hemibody irradiation alone is less toxic than either upper hemibody irradiation or /sup 32/P treatment.
Aziz, H.; Choi, K.; Sohn, C.; Yaes, R.; Rotman, M.
This document presents the as-run analysis of the AGR-2 irradiation experiment. AGR-2 is the second of the planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Very High Temperature Reactor (VHTR) Technical Development Office (TDO) program. The objectives of the AGR-2 experiment are to: (a) Irradiate UCO (uranium oxycarbide) and UO2 (uranium dioxide) fuel produced in a large coater. Fuel attributes are based on results obtained from the AGR-1 test and other project activities. (b) Provide irradiated fuel samples for post-irradiation experiment (PIE) and safety testing. (c) Support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. The primary objective of the test was to irradiate both UCO and UO2 TRISO (tri-structural isotropic) fuel produced from prototypic scale equipment to obtain normal operation and accident condition fuel performance data. The UCO compacts were subjected to a range of burnups and temperatures typical of anticipated prismatic reactor service conditions in three capsules. The test train also includes compacts containing UO2 particles produced independently by the United States, South Africa, and France in three separate capsules. The range of burnups and temperatures in these capsules were typical of anticipated pebble bed reactor service conditions. The results discussed in this report pertain only to U.S. produced fuel. In order to achieve the test objectives, the AGR-2 experiment was irradiated in the B-12 position of the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) for a total irradiation duration of 559.2 effective full power days (EFPD). Irradiation began on June 22, 2010, and ended on October 16, 2013, spanning 12 ATR power cycles and approximately three and a half calendar years. The test contained six independently controlled and monitored capsules. Each U.S. capsule contained 12 compacts of either UCO or UO2 AGR coated fuel. No fuel particles failed during the AGR-2 irradiation. Final burnup values on a per compact basis ranged from 7.26 to 13.15% FIMA (fissions per initial heavy-metal atom) for UCO fuel, and 9.01 to 10.69% FIMA for UO2 fuel, while fast fluence values ranged from 1.94 to 3.47�1025 n/m2 (E >0.18 MeV) for UCO fuel, and from 3.05 to 3.53�1025 n/m2 (E >0.18 MeV) for UO2 fuel. Time-average volume-average (TAVA) temperatures on a capsule basis at the end of irradiation ranged from 987�C in Capsule 6 to 1296�C in Capsule 2 for UCO, and from 996 to 1062�C in UO2-fueled Capsule 3. By the end of the irradiation, all of the installed thermocouples (TCs) had failed. Fission product release-to-birth (R/B) ratios were quite low. In the UCO capsules, R/B values during the first three cycles were below 10-6 with the exception of the hotter Capsule 2, in which the R/Bs reached 2�10-6. In the UO2 capsule (Capsule 3), the R/B values during the first three cycles were below 10-7. R/B values for all following cycles are not reliable due to gas flow and cross talk issues.
Blaise, Collin
Synthesis of nanosize BPO{sub 4} under microwave irradiation
Highlights: ? Nanosize BPO{sub 4} are prepared under microwave-irradiation conditions. ? This reaction is only performed at less than 640 W power for 2.5�5 min. ? The particles of sample irradiated at 400 W are 40�90 nm in size and well dispersed. ? A simple, fast and green procedure for synthesis of nanosize BPO{sub 4} is developed. -- Abstract: Nanosize BPO{sub 4} was synthesized using H{sub 3}BO{sub 3} and H{sub 3}PO{sub 4} (85%) as raw materials under microwave irradiation. This reaction was performed at powers lower than 640 W and irradiation time ranging from 2.5 min to 5 min, which were only a fraction of the time required for conventional synthetic procedures. The structure of the as-prepared BPO{sub 4} is analogous to that of a high cristobalite. The particle sizes of the samples irradiated at 640 and 400 W range from 40 nm to 90 nm and 30 nm to 60 nm, respectively. The effects of different conditions on the experimental outcome are also discussed.
Wang, Rui, E-mail: email@example.com [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China) [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116023 (China); Jiang, Heng; Gong, Hong; Zhang, Jun [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China)] [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China)
Atomic and molecular interstellar absorption lines toward the high galactic latitude stars HD~141569 and HD~157841 at ultra-high resolution
We present ultra-high resolution (0.32 km/s) spectra obtained with the 3.9m Anglo-Australian Telescope (AAT) and Ultra-High-Resolution Facility (UHRF), of interstellar NaI D1, D2, Ca II K, K I and CH absorption toward two high galactic latitude stars HD141569 and HD157841. We have compared our data with 21-cm observations obtained from the Leiden/Dwingeloo HI survey. We derive the velocity structure, column densities of the clouds represented by the various components and identify the clouds with ISM structures seen in the region at other wavelengths. We further derive abundances, linear depletions and H2 fractional abundances for these clouds, wherever possible. Toward HD141569, we detect two components in our UHRF spectra : a weak, broad component at - 15 km/s, seen only in CaII K absorption and another component at 0 km/s, seen in NaI D1, D2, Ca II K, KI and CH absorption. In the case of the HD157841 sightline, a total of 6 components are seen on our UHRF spectra in NaI D1, D2 Ca II K, K I and CH absorption. 2 of these 6 components are seen only in a single species.
M. S. Sahu; J. C. Blades; L. He; D. Hartmann; M. J. Barlow; I. A. Crawford
AGR-1 Irradiation Test Final As-Run Report
This document presents the as-run analysis of the AGR-1 irradiation experiment. AGR-1 is the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the US Department of Energy (DOE) as part of the Next-Generation Nuclear Plant (NGNP) project. The objectives of the AGR-1 experiment are: 1. To gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. 2. To irradiate fuel produced in conjunction with the AGR fuel process development effort. 3. To provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. In order to achieve the test objectives, the AGR-1 experiment was irradiated in the B-10 position of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) for a total duration of 620 effective full power days of irradiation. Irradiation began on December 24, 2006 and ended on November 6, 2009 spanning 13 ATR cycles and approximately three calendar years. The test contained six independently controlled and monitored capsules. Each capsule contained 12 compacts of a single type, or variant, of the AGR coated fuel. No fuel particles failed during the AGR-1 irradiation. Final burnup values on a per compact basis ranged from 11.5 to 19.6 %FIMA, while fast fluence values ranged from 2.21 to 4.39 ?1025 n/m2 (E >0.18 MeV). We�ll say something here about temperatures once thermal recalc is done. Thermocouples performed well, failing at a lower rate than expected. At the end of the irradiation, nine of the originally-planned 19 TCs were considered functional. Fission product release-to-birth (R/B) ratios were quite low. In most capsules, R/B values at the end of the irradiation were at or below 10-7 with only one capsule significantly exceeding this value. A maximum R/B of around 2?10-7 was reached at the end of the irradiation in Capsule 5. Several shakedown issues were encountered and resolved during the first three cycles. These include the repair of minor gas line leaks; repair of faulty gas line valves; the need to position moisture monitors in regions of low radiation fields for proper functioning; the enforcement of proper on-line data storage and backup, the need to monitor thermocouple performance, correcting for detector spectral gain shift, and a change in the mass flow rate range of the neon flow controllers.
Blaise P. Collin
Irradiation behavior of miniature experimental uranium silicide fuel plates
Uranium silicides, because of their relatively high uranium density, were selected as candidate dispersion fuels for the higher fuel densities required in the Reduced Enrichment Research and Test Reactor (RERTR) Program. Irradiation experience with this type of fuel, however, was limited to relatively modest fission densities in the bulk from, on the order of 7 x 10/sup 20/ cm/sup -3/, far short of the approximately 20 x 10/sup 20/ cm/sup -3/ goal established for the RERTR program. The purpose of the irradiation experiments on silicide fuels on the ORR, therefore, was to investigate the intrinsic irradiation behavior of uranium silicide as a dispersion fuel. Of particular interest was the interaction between the silicide particles and the aluminum matrix, the swelling behavior of the silicide particles, and the maximum volume fraction of silicide particles that could be contained in the aluminum matrix.
Hofman, G.L.; Neimark, L.A.; Mattas, R.F.
Radiation Damage Study in Natural Zircon Using Neutrons Irradiation
Changes of atomic displacements in crystalline structure of natural zircon (ZrSiO{sub 4}) can be studied by using neutron irradiation on the surface of zircon and compared the data from XRD measurements before and after irradiation. The results of neutron irradiation on natural zircon using Pneumatic Transfer System (PTS) at PUSPATI TRIGA Research Reactor in the Malaysian Nuclear Agency are discussed in this work. The reactor produces maximum thermal power output of 1 MWatt and the neutron flux of up to 1x10{sup 13} ncm{sup -2}s{sup -1}. From serial decay processes of uranium and thorium radionuclides in zircon crystalline structure, the emission of alpha particles can produce damage in terms of atomic displacements in zircon. Hence, zircon has been extensively studied as a possible candidate for immobilization of fission products and actinides.
Lwin, Maung Tin Moe; Amin, Yusoff Mohd.; Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mohamed, Abdul Aziz [Materials Technology Group, Industrial Technology Division, Malaysian Nuclear Agency Bangi, 43000 Kajang, Selangor Darul Ehsan (Malaysia); Karim, Julia Abdul [Reactor Physics Section, Nuclear Power Division, Malaysian Nuclear Agency Bangi, 43000 Kajang, Selangor Darul Ehsan (Malaysia)
Neutron and gamma irradiation damage to organic materials.
This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at < 200 C. In short, there are no gamma and neutron irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.
White, Gregory Von, II; Bernstein, Robert
On the Absorption and Redistribution of Energy in Irradiated Planets
We present a sequence of toy models for irradiated planet atmospheres, in which the effects of geometry and energy redistribution are modelled self-consistently. We use separate but coupled grey atmosphere models to treat the ingoing stellar irradiation and outgoing planetary reradiation. We investigate how observed quantities such as full phase secondary eclipses and orbital phase curves depend on various important parameters, such as the depth at which irradiation is absorbed and the depth at which energy is redistributed. We also compare our results to the more detailed radiative transfer models in the literature, in order to understand how those map onto the toy model parameter space. Such an approach can prove complementary to more detailed calculations, in that they demonstrate, in a simple way, how the solutions change depending on where, and how, energy redistribution occurs. As an example of the value of such models, we demonstrate how energy redistribution and temperature equilibration at moderate o...
Hansen, Brad
[Grain boundary and interface kinetics during ion irradiation
Proposed here is renewed support of a research program focused on interface motion and phase transformation during ion irradiation, with emphasis on elemental semiconductors. Broadly speaking, the aims of this program are to explore defect kinetics in amorphous and crystalline semiconductors, and to relate defect dynamics to interface motion and phase transformations. Over the last three years, we initiated a program under DOE support to explore crystallization and amorphization of elemental semiconductors under irradiation. This research has enabled new insights about the nature of defects in amorphous semiconductors and about microstructural evolution in the early stages of crystallization. In addition, we have demonstrated almost arbitrary control over the relative rates of crystal nucleation and crystal growth in silicon. As a result, the impinged grain microstructure of thin (100 nm) polycrystalline films crystallized under irradiation can be controlled with grain sizes ranging from a few nanometers to several micrometers, which may have interesting technological implications.
Atwater, H.A.
(Grain boundary and interface kinetics during ion irradiation)
Hydrated metal oxides or oxyhydroxides boehmite and gibbsite that can form on spent aluminum-clad nuclear fuel assemblies during in-core and post-discharge wet storage were exposed as granular powders to gamma irradiation in a {sup 60}Co irradiator in closed laboratory test vessels with air and with argon as separate cover gases. The results show that boehmite readily evolves hydrogen with exposure up to a dose of 1.8 x 10{sup 8} rad, the maximum tested, in both a full-dried and moist condition of the powder, whereas only a very small measurable quantity of hydrogen was generated from the granular powder of gibbsite. Specific information on the test setup, sample characteristics, sample preparation, irradiation, and gas analysis are described.
Fisher, D.; Westbrook, M.; Sindelar, R.
Physiological Interaction of Heart and Lung in Thoracic Irradiation
Introduction: The risk of early radiation-induced lung toxicity (RILT) limits the dose and efficacy of radiation therapy of thoracic tumors. In addition to lung dose, coirradiation of the heart is a known risk factor in the development RILT. The aim of this study was to identify the underlying physiology of the interaction between lung and heart in thoracic irradiation. Methods and Materials: Rat hearts, lungs, or both were irradiated to 20 Gy using high-precision proton beams. Cardiopulmonary performance was assessed using breathing rate measurements and F{sup 18}-fluorodeoxyglucose positron emission tomography ({sup 18}F-FDG-PET) scans biweekly and left- and right-sided cardiac hemodynamic measurements and histopathology analysis at 8 weeks postirradiation. Results: Two to 12 weeks after heart irradiation, a pronounced defect in the uptake of {sup 18}F-FDG in the left ventricle (LV) was observed. At 8 weeks postirradiation, this coincided with LV perivascular fibrosis, an increase in LV end-diastolic pressure, and pulmonary edema in the shielded lungs. Lung irradiation alone not only increased pulmonary artery pressure and perivascular edema but also induced an increased LV relaxation time. Combined irradiation of lung and heart induced pronounced increases in LV end-diastolic pressure and relaxation time, in addition to an increase in right ventricle end-diastolic pressure, indicative of biventricular diastolic dysfunction. Moreover, enhanced pulmonary edema, inflammation and fibrosis were also observed. Conclusions: Both lung and heart irradiation cause cardiac and pulmonary toxicity via different mechanisms. Thus, when combined, the loss of cardiopulmonary performance is intensified further, explaining the deleterious effects of heart and lung coirradiation. Our findings show for the first time the physiological mechanism underlying the development of a multiorgan complication, RILT. Reduction of dose to either of these organs offers new opportunities to improve radiation therapy treatment of thoracic tumors, potentially facilitating increased treatment doses and tumor control.
Ghobadi, Ghazaleh; Veen, Sonja van der [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands) [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Bartelds, Beatrijs [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)] [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Boer, Rudolf A. de [Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)] [Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Dickinson, Michael G. [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)] [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Jong, Johan R. de [Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)] [Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Faber, Hette; Niemantsverdriet, Maarten [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands) [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Brandenburg, Sytze [Kernfysisch Versneller Instituut, University of Groningen, Groningen (Netherlands)] [Kernfysisch Versneller Instituut, University of Groningen, Groningen (Netherlands); Berger, Rolf M.F. [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)] [Center for Congenital Heart Disease, Beatrix Children Hospital, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)] [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands) [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: firstname.lastname@example.com [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)
Threshold irradiation dose for amorphization of silicon carbide
The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be {approximately}0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si{sup +} at 1 x 10{sup -3} dpa/s and with fission neutrons irradiated at 1 x 10{sup -6} dpa/s irradiated to 15 dpa in the temperature range of {approximately}340{+-}10K.
Snead, L.L.; Zinkle, S.J.
Structural and luminescent properties of electron-irradiated silicon
Structural defects induced by electron irradiation of p-Cz-Si wafers were identified. The influence of the annealing conditions in a chlorine-containing atmosphere on the structural and luminescent properties of the samples was examined. Light-emitting diodes based on electron-irradiated and high-temperature-annealed wafers were fabricated by a vapour-phase epitaxy technique and their luminescence properties were studied. A high-intensity dislocation-related D1 line was observed at 1.6 ?m in the room-temperature electroluminescence spectrum.
Sobolev, N. A.; Loshachenko, A. S. [Ioffe Physical-Technical Institute, 194021 St. Petersburg, Russia and Fok Institute of Physics, St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Aruev, P. N.; Kalyadin, A. E.; Shek, E. I.; Zabrodskiy, V. V. [Ioffe Physical-Technical Institute, 194021 St. Petersburg (Russian Federation); Shtel'makh, K. F. [Ioffe Physical-Technical Institute, 194021 St. Petersburg, Russia and St. Petersburg State Technical University, 195251 St. Petersburg (Russian Federation); Vdovin, V. I. [Rzhanov Institute of Semiconductor Physics, 630090 Novosibirsk (Russian Federation); Xiang, Luelue; Yang, Deren [State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, 310027 Hangzhou (China)
Fission product release from irradiated LWR fuel under accident conditions
Fission product release from irradiated LWR fuel is being studied by heating fuel rod segments in flowing steam and an inert carrier gas to simulate accident conditions. Fuels with a range of irradiation histories are being subjected to several steam flow rates over a wide range of temperatures. Fission product release during each test is measured by gamma spectroscopy and by detailed examination of the collection apparatus after the test has been completed. These release results are complemented by a detailed posttest examination of samples of the fuel rod segment. Results of release measurements and fuel rod characterizations for tests at 1400 through 2000/sup 0/C are presented in this paper.
Strain, R.V.; Sanecki, J.E.; Osborne, M.F.
Enhanced electrochemical etching of ion irradiated silicon by localized amorphization
A tailored distribution of ion induced defects in p-type silicon allows subsequent electrochemical anodization to be modified in various ways. Here we describe how a low level of lattice amorphization induced by ion irradiation influences anodization. First, it superposes a chemical etching effect, which is observable at high fluences as a reduced height of a micromachined component. Second, at lower fluences, it greatly enhances electrochemical anodization by allowing a hole diffusion current to flow to the exposed surface. We present an anodization model, which explains all observed effects produced by light ions such as helium and heavy ions such as cesium over a wide range of fluences and irradiation geometries.
Dang, Z. Y.; Breese, M. B. H. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore Singapore 117542 (Singapore); Lin, Y.; Tok, E. S. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Vittone, E. [Physics Department, NIS Excellence Centre and CNISM, University of Torino, via Pietro Giuria 1, 10125 Torino (Italy)
Thermal response of photovoltaic cell to laser beam irradiation
This paper firstly presents the concept of using dual laser beam to irradiate the photovoltaic cell, so as to investigate the temperature dependency of the efficiency of long distance energy transmission. Next, the model on the multiple reflection and absorption of any monochromatic light in multilayer structure has been established, and the heat generation in photovoltaic cell has been interpreted in this work. Then, the finite element model has been set up to calculate the temperature of photovoltaic cell subjected to laser irradiation. Finally, the effect of temperature elevation on the efficiency and reliability of photovoltaic cell has been discussed to provide theoretical references for designing the light-electricity conversion system.
Yuan, Yu-Chen
The effects of gamma irradiation on Serratia marcescens
that there was little difference in the five strains. This suggests that growth rates do not alter the survival curves. The effects of irradiation on pigmentation ability were studied using the wild type, nims, and the more-resistant R-25. Pyrex tubes, 16 x 150 mm...). 5. D. L. Dewey, The X-ray sensitivity of Serratia marcescens. Radiation Res. 19, 64-87 (1963). 6. D. L. Dewey, Effect of irradiation on the ability of Pseudonrtnas to synthesize two inducible enzymes. Radiation Res. 21, 367-75 (1964). 7. F...
Bartlett, William Thomas
Properties of solar gravity mode signals in total irradiance observations
Further evidence has been found that a significant fraction of the gravity mode power density in the total irradiance observations appears in sidebands of classified eigenfrequencies. These sidebands whose amplitudes vary from year to year are interpreted as harmonics of the rotational frequencies of the nonuniform solar surface. These findings are for non axisymmetric modes and corroborate the findings of Kroll, Hill and Chen for axisymmetric modes. It is demonstrated the the generation of the sidebands lifts the usual restriction on the parity of the eigenfunctions for modes detectable in total irradiance observations. 14 refs.
Kroll, R.J.; Chen, J.; Hill, H.A.
Light water reactor mixed-oxide fuel irradiation experiment
The United States Department of Energy Office of Fissile Materials Disposition is sponsoring and Oak Ridge National Laboratory (ORNL) is leading an irradiation experiment to test mixed uranium-plutonium oxide (MOX) fuel made from weapons-grade (WG) plutonium. In this multiyear program, sealed capsules containing MOX fuel pellets fabricated at Los Alamos National Laboratory (LANL) are being irradiated in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). The planned experiments will investigate the utilization of dry-processed plutonium, the effects of WG plutonium isotopics on MOX performance, and any material interactions of gallium with Zircaloy cladding.
Hodge, S.A.; Cowell, B.S. [Oak Ridge National Lab., TN (United States); Chang, G.S.; Ryskamp, J.M. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.
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 MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/Surface ReactionsIrradiation Effects onIrradiation
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 MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/Surface ReactionsIrradiation EffectsIrradiation
CH2M HILL Plateau Remediation Company (CH2M HILL PRC) is proud to submit the Slightly Irradiated Fuel (SIF) Interim Disposition Project for consideration by the Project Management Institute as Project of the Year for 2010. The SIF Project was a set of six interrelated sub-projects that delivered unique stand-alone outcomes, which, when integrated, provided a comprehensive and compliant system for storing high risk special nuclear materials. The scope of the six sub-projects included the design, construction, testing, and turnover of the facilities and equipment, which would provide safe, secure, and compliant Special Nuclear Material (SNM) storage capabilities for the SIF material. The project encompassed a broad range of activities, including the following: Five buildings/structures removed, relocated, or built; Two buildings renovated; Structural barriers, fencing, and heavy gates installed; New roadways and parking lots built; Multiple detection and assessment systems installed; New and expanded communication systems developed; Multimedia recording devices added; and A new control room to monitor all materials and systems built. Project challenges were numerous and included the following: An aggressive 17-month schedule to support the high-profile Plutonium Finishing Plant (PFP) decommissioning; Company/contractor changeovers that affected each and every project team member; Project requirements that continually evolved during design and construction due to the performance- and outcome-based nature ofthe security objectives; and Restrictions imposed on all communications due to the sensitive nature of the projects In spite of the significant challenges, the project was delivered on schedule and $2 million under budget, which became a special source of pride that bonded the team. For years, the SIF had been stored at the central Hanford PFP. Because of the weapons-grade piutonium produced and stored there, the PFP had some of the tightest security on the Hanford nuclear reservation. Workers had to pass through metal detectors when they arrived at the plant and materials leaving the plant had to be scanned for security reasons. Whereas other high-security nuclear materials were shipped from the PFP to Savannah River, S.C. as part ofa Department of Energy (DOE) program to consolidate weapons-grade plutonium, it was determined that the SIF should remain onsite pending disposition to a national repository. Nevertheless, the SIF still requires a high level of security that the PFP complex has always provided. With the 60-year PFP mission of producing and storing plutonium concluded, the environmental cleanup plans for Hanford call for the demolition of the 63-building PFP complex. Consequently, if the SIF remained at PFP it not only would have interfered with the environmental cleanup plans, but would have required $100 million in facility upgrades to meet increased national security requirements imposed after the 9/11 terrorist attacks. A new smaller and more cost-effective area was needed to store this material, which led to the SIF Project. Once the SIF project was successfully completed and the SIF was safely removed from PFP, the existing Protected Area at PFP could be removed, and demolition could proceed more quickly without being encumbered by restrictive security requirements that an active Protected Area requires. The lightened PFP security level brought by safely removing and storing the SIF would also yield lowered costs for deactivation and demolition, as well as reduce overall life-cycle costs.
Radiochemical Transformation of High Pressure Methane under Gamma, Electron, and Neutron Irradiation
The chemical effects of irradiation on high pressure methane and noble gas mixtures were investigated using gamma, electron beam, and neutron irradiation sources. The gamma source used was the La-140 source from the Nuclear Science Center (NSC...
Clemens, Jeffrey Tyler
Etch-free Formation of Porous Silicon by High-energy Ion Irradiation...
Etch-free Formation of Porous Silicon by High-energy Ion Irradiation. Etch-free Formation of Porous Silicon by High-energy Ion Irradiation. Abstract: In this study, porous silicon...
U.S. consumers' acceptance and willingness to buy irradiated food
in their decisions regarding irradiated foods. Education programs seem to have positive effects on shaping consumer opinion about irradiation, which can improve the safety of food products. Thus, the results of this study provide useful information required...
Poghosyan, Arsen Vahagn
Radiosensitization Strategies for Enhanced E-beam Irradiation Treatment of Fresh Produce
necessary to develop treatments that will reduce their prevalence and numbers on fresh produce. Irradiation is a penetrating nonthermal treatment that effectively eliminates bacteria. Irradiated baby spinach leaves up to 1.0 kGy showed negligible (P>0...
Gomes, Carmen
Conjugated linoleic acid reduces lipid oxidation in irradiated, cooked ground beef patties
This study was conducted to examine the antioxidative effect of conjugated linoleic acid (CLA) in irradiated, cooked ground beef patties. The hypothesis was that CLA would be retained during irradiation and would reduce lipid oxidation...
Chae, Sung Hee
Electron Irradiation Induced Changes of the Electrical Transport Properties of Graphene
. In addition, the effect of electron irradiation on a PMMA (Poly Methyl Methacrylate)/Graphene bilayer was studied. We observed a deterioration of the electrical transport properties of a graphene FET. Prior to electron irradiation, we observed that the PMMA...
Woo, Sung Oh
E-Print Network 3.0 - alleviates irradiation-induced brain Sample...
irradiation-induced brain Search Powered by Explorit Topic List Advanced Search Sample search results for: alleviates irradiation-induced brain Page: << < 1 2 3 4 5 > >> 1 ORIGINAL...
Response of nanostructured ferritic alloys to high-dose heavy ion irradiation
A latest-generation aberration-corrected scanning/transmission electron microscope (STEM) is used to study heavy-ion-irradiated nanostructured ferritic alloys (NFAs). Results are presented for STEM X-ray mapping of NFA 14YWT irradiated with 10 MeV Pt to 16 or 160 dpa at -100�C and 750�C, as well as pre-irradiation reference material. Irradiation at -100�C results in ballistic destruction of the beneficial microstructural features present in the pre-irradiated reference material, such as Ti-Y-O nanoclusters (NCs) and grain boundary (GB) segregation. Irradiation at 750�C retains these beneficial features, but indicates some coarsening of the NCs, diffusion of Al to the NCs, and a reduction of the Cr-W GB segregation (or solute excess) content. Ion irradiation combined with the latest-generation STEM hardware allows for rapid screening of fusion candidate materials and improved understanding of irradiation-induced microstructural changes in NFAs.
Parish, Chad M.; White, Ryan M.; LeBeau, James M.; Miller, Michael K.
E-Print Network 3.0 - animal irradiation preliminary Sample Search...
Centre de mathmatiques Collection: Mathematics 97 Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet X-rays and 60 Summary: 1 Irradiation of Nd-Fe-B...
E-Print Network 3.0 - accelerator irradiation issledovaniya Sample...
Group Collection: Physics 66 Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet X-rays and 60 Summary: of 260 Mrad was used to irradiate Nd-Fe-B sample magnets with...
Ion irradiation of Fe-Fe oxide core-shell nanocluster films:...
irradiation of Fe-Fe oxide core-shell nanocluster films: Effect of interface on stability of magnetic properties. Ion irradiation of Fe-Fe oxide core-shell nanocluster films:...
Mutation Research 568 (2004) 4148 Detection of chromosomal instability in -irradiated
in the progeny at subsequent generations (genomic instability) and in non-irradiated neighbors of irradiated the link between the radiation-induced phenomena of genomic instability and the bystander effect. © 2004
E-Print Network 3.0 - argon ion irradiation Sample Search Results
mathmatiques Collection: Mathematics 3 Straightening Suspended Single Walled Carbon Nanotubes by Ion Irradiation Summary: Straightening Suspended Single Walled Carbon Nanotubes...
Irradiation Testing of Blanket Materials at the HFR Petten with On Line Tritium Monitoring
Irradiation experiments are performed in support of fusion blanket technology development. These comprise ceramic solid breeder materials, and a liquid Lithium Lead alloy, as well as blanket subassemblies and components. Experimental facilities at the HFR to study tritium release, permeation characteristics, and neutron irradiation performance, have recently been extended. This paper gives an overview on the tritium breeding materials irradiation programme and describes the facilities required for irradiation testing and on-line tritium measurement.
Magielsen, A.J.; Laan, J.G. van der; Hegeman, J.B.J.; Stijkel, M.P.; Ooijevaar, M.A.G
Development and testing of an aerosol/stratus cloud parameterization scheme for middle and high latitudes. Year 3 technical progress report, November 1, 1996--August 31, 1997
At the present time, general circulation models (GCMs) poorly represent clouds, to the extent that they cannot be relied upon to simulate the climatic effects of increasing concentrations of greenhouse gases, or of anthropogenic perturbations to concentrations of cloud condensation nuclei (CCN) or ice nuclei (IN). The net radiative forcing of clouds varies strongly with latitude. Poleward of 30 degrees in both hemispheres, low-level clouds create a net cooling effect corresponding to radiative divergences of {minus}50 to {minus}100 W/m{sup 2}. It is likely that a combination of fogs, boundary-layer stratocumulus, and stratus clouds are the main contributors to this forcing. Models of the response of the microphysical and radiative properties of clouds to changes in aerosol abundance, for a variety of large-scale meteorological forcings, are important additions to GCMs used for the study of the role of Arctic systems in global climate. The overall objective of this research is the development of an aerosol/cloud microphysics parameterization of mixed-phase stratus and boundary-layer clouds which responds to variations in CCN and IN. The parameterization is to be designed for ultimate use in GCM simulations as a tool in understanding the role of CCN, IN, and Arctic clouds in radiation budgets. Several versions of the CSU RAMS (Regional Atmospheric Modeling System) will be used during the course of this work. The parameterizations developed in this research are intended for application in a single-column cloud model, designed as an adaptive grid model which can interface into a GCM vertical grid through distinct layers of the troposphere where the presence of layer clouds is expected.
Kreidenweis, S.M.; Cotton, W.R.
SURVEILLANCE OF PHOTOVOLTAIC SOLAR ENERGY SYSTEMS USING METEOSAT DERIVED IRRADIANCES Annette email@example.com 2Enecolo AG, Lindhof 235, CH-8617 M¨onchaltorf 3Fraunhofer Insitute for Solar Energy Systems Wiemken3, Hans Georg Beyer4, Vincent van Dijk5, Jethro Betcke5 1Dept. of Energy and Semiconductor Research
Heinemann, Detlev
SOLAR IRRADIANCE FORECASTING FOR THE MANAGEMENT OF SOLAR ENERGY SYSTEMS Detlev Heinemann email@example.com ABSTRACT Solar energy is expected to contribute major shares of the future global energy supply. Due to its and solar energy conversion processes has to account for this behaviour in respective operating strategies
The modelling of irradiation embrittlement in submerged-arc welds
Until very recently, the irradiation embrittlement behavior of submerged-arc welds has been interpreted in terms of two mechanisms, namely a matrix damage component and an additional component due to the irradiation-enhanced production of copper-rich precipitates. However, some of the weld specimens from a recent accelerated re-irradiation experiment have shown high Charpy shifts which exceeded the values expected from the measured shift in yield stress. Microstructural examination has revealed the occurrence of intergranular fracture (IGF) in these specimens, accompanied by grain boundary segregation of phosphorus. Theoretical models were developed to predict the parametric dependence of irradiation-enhanced phosphorus segregation on experimental variables. Using these parametric forms, along with the concept of a critical level of segregation for the onset of IGF instead of cleavage, a three mechanism trend curve has been developed. The form of this trend curve, taking into account IGF as well as matrix and copper embrittlement, is thus mechanistically based. The constants in the equation, however, are obtained by a statistical fit to the actual Charpy shift database.
Bolton, C.J.; Buswell, J.T.; Jones, R.B.; Moskovic, R.; Priest, R.H. [Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre
Simultaneous Irradiation and Imaging of Blood Vessels During Pulsed
energy produced hemorrhage. In larger vessels, coagula often were attached to the superficial vessel wall; port wine stains INTRODUCTION Previous studies examining the effect of la- ser irradiation on cutaneous preparation. The short pulse duration illus- trated an extreme; energy was deposited quickly Contract grant
Barton, Jennifer K.
Development of a chemical dosimeter for electron beam food irradiation
uniform irradiation treatment on apple-phantoms (a complex shaped target) and GAFCHROMIC® HD-810 films using electron beams from (1) a 2 MeV Van de Graaff (VDG) accelerator, (2) a 10 MeV Linear Accelerator (LINAC), and (3) X-rays from a 5 MeV LINAC...
Rivadeneira, Ramiro Geovanny
RETHINKING SATELLITE BASED SOLAR IRRADIANCE MODELLING R. W. Mueller
of Oldenburg, D-26111 Oldenburg; 2-University of Bergen; 3-Fraunhofer Institute for Solar Energy Systems; 4-German Aerospace Center; 5-Ecole des Mines de Paris ABSTRACT Accurate solar irradiance data are not only necessary for an efficient planning and operation of solar energy systems. Within the European project
adt materials irradiated: Topics by E-print Network
adt materials irradiated First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Umsetzung von ADTs ADT in...
Large Animal Irradiation J. Daniel Bourland, PhD
Departments of Physics and Biomedical Engineering Wake Forest School of Medicine Winston-Salem, North Carolina · Summary #12;Irradiation Issues same as for humans · Animal size (nominal L x W x H) · Photon energy (to Beam (high energy) Orthovoltage or Diagnostic X rays (low energy) #12;Isodose Curves Representing
Lymphocyte depletion in peripheral blood of gamma irradiated rats
38. F. H. Hager, A study of the effect of partial-body irradiation on the early reduction of circulating lymphocytes. (Thesis) Texas AKM University, 1969. 39. G. D'Angelo and M. Lacombe, A practical diluent for electz onic white cell counts. Amer...
Goldin, Eric Michael
Spatial Pattern Formation in Fused Silica Under UV Irradiation
Spatial Pattern Formation in Fused Silica Under UV Irradiation Problem Presenter Leslie Button lenses gradually degrades and ultimately damages these optical components. Corning is a global supplier of optical and ceramic materials across various industries and is particularly interested in this damage
Edwards, David A.
Vacuum aperture isolator for retroreflection from laser-irradiated target
The disclosure is directed to a vacuum aperture isolator for retroreflection of a laser-irradiated target. Within a vacuum chamber are disposed a beam focusing element, a disc having an aperture and a recollimating element. The edge of the focused beam impinges on the edge of the aperture to produce a plasma which refracts any retroreflected light from the laser's target.
Benjamin, Robert F. (Los Alamos, NM); Mitchell, Kenneth B. (Los Alamos, NM)
The AGR-1 Irradiation -Objectives, Success Criteria and Risk Management
The AGR-1 experiment being conducted by the US Department of Energy Advanced Gas Reactor Fuel Development and Qualification Program (AGR fuel program) will irradiate TRISO-coated particle fuel in compacts under conditions representative of a Very High Temperature Reactor (VHTR) core. The anticipated fuel performance requirements of a prismatic core VHTR significantly exceed established TRISO-coated particle fuel capability in terms of burnup, temperature and fast fluence. AGR-1 is the first in a planned series of eight irradiations leading to the qualification of low enriched uranium coated particle fuel compacts for service in a VHTR, as identified in an overall Technical Program Plan produced at the beginning of the program . The AGR-1 experiment is scheduled for insertion in the Advanced Test Reactor (ATR) in the first quarter of fiscal year 2007 and to be irradiated for a period of up to approximately two and a half years. The irradiation rig, designated a "test train" is designed to provide six independently controlled (for temperature) and monitored (for fission product gas release) capsules containing fuel samples.
James Kendall
Proton Irradiation Damage Assessment of Carbon Reinforced Composites
Proton Irradiation Damage Assessment of Carbon Reinforced Composites: 2-D & 3-D Weaved Structures carbon-carbon composite ATJ Graphite 3D CC composite AGS Beam-on-Target tests show clearly that carbon composites are better absorbers of thermo- mechanical shock. This is attributed to the very low coeff
Post Irradiation Capabilities at the Idaho National Laboratory
The U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) oversees the research, development, and demonstration activities that ensure nuclear energy remains a viable energy option for the United States. Fuel and material development through fabrication, irradiation, and characterization play a significant role in accomplishing the research needed to support nuclear energy. All fuel and material development requires the understanding of irradiation effects on the fuel performance and relies on irradiation experiments ranging from tests aimed at targeted scientific questions to integral effects under representative and prototypic conditions. The DOE recently emphasized a solution-driven, goal-oriented, science-based approach to nuclear energy development. Nuclear power systems and materials were initially developed during the latter half of the 20th century and greatly facilitated by the United States ability and willingness to conduct large-scale experiments. Fifty-two research and test reactors with associated facilities for performing fabrication and pre and post irradiation examinations were constructed at what is now Idaho National Laboratory (INL), another 14 at Oak Ridge National Laboratory (ORNL), and a few more at other national laboratory sites. Building on the scientific advances of the last several decades, our understanding of fundamental nuclear science, improvements in computational platforms, and other tools now enable technological advancements with less reliance on large-scale experimentation.
Schulthess, J.L.
The U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) oversees the research, development, and demonstration activities that ensure nuclear energy remains a viable energy option for the United States. Fuel and material development through fabrication, irradiation, and characterization play a significant role in accomplishing the research needed to support nuclear energy. All fuel and material development requires the understanding of irradiation effects on the fuel performance and relies on irradiation experiments ranging from tests aimed at targeted scientific questions to integral effects under representative and prototypic conditions. The DOE recently emphasized a solution-driven, goal-oriented, science-based approach to nuclear energy development. Nuclear power systems and materials were initially developed during the latter half of the 20th century and greatly facilitated by the United States� ability and willingness to conduct large-scale experiments. Fifty-two research and test reactors with associated facilities for performing fabrication and pre and post irradiation examinations were constructed at what is now Idaho National Laboratory (INL), another 14 at Oak Ridge National Laboratory (ORNL), and a few more at other national laboratory sites. Building on the scientific advances of the last several decades, our understanding of fundamental nuclear science, improvements in computational platforms, and other tools now enable technological advancements with less reliance on large-scale experimentation.
Schulthess, J.L.; Robert D. Mariani; Rory Kennedy; Doug Toomer
Compressive Strength of Gamma-Irradiated Polymer Concrete
Compressive Strength of Gamma-Irradiated Polymer Concrete Gonzalo Marti´nez-Barrera,1,2 Uriel concrete (PC) was developed by using differ- ent concentrations of silica sand as aggregate of Plastics Engineers INTRODUCTION Polymer concrete (PC) is a particulate composite where thermoset resins
North Texas, University of
atomic hydrogen irradiation: Topics by E-print Network
hydrogen irradiation First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Synergistic Formation of Radicals...
Thermoelastic Generation of Ultrasound by Line-Focused Laser Irradiation
Thermoelastic Generation of Ultrasound by Line-Focused Laser Irradiation Irene Arias and Jan D 60208, USA Abstract A two-dimensional theoretical model for the field generated in the thermoelas- tic for the model. Some representative results are presented to illustrate the generated field and provide insight
Huerta, Antonio
Evaluating Quality and Palatability Characteristics of Beef Subprimals Treated with Low-dose Irradiation
. Paired subprimals were randomly assigned to treated (irradiated) and control (non-irradiated) groups. The treated group was irradiated with a surface dose of 1-1.5 kGy. Following treatment, subprimals were fabricated into thirds and randomly assigned...
Arnold, John
Dose characterization of the rad source 2400 x-ray irradiator
The RS 2400 irradiator has been looked to as a replacement for discontinued gamma irradiators. The RS 2400 has a cylindrical, rather than point, x-ray source, which yields higher dose rates. The irradiator unit allows the user to set the current...
Wagner, Jennifer Ann Koop
Irradiation Studies of Optical Components CERN, ~ April 15-24, 2005
Irradiation Studies of Optical Components 43 2 5 1 CERN, ~ April 15-24, 2005 1 GeV proton beam 4 x, 2005Optical components #12;Irradiation summary transmittance/reflectance measurements Activity right 10 15 proton Irradiation dose: equivalent to 40 pulses of 24 GeV proton beam Received radiation dose
Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation
- grade their optical properties. In this paper, we report on the effects of gamma irradiationRapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation Nathan J. Withers of 137 Cs gamma irradiation on photoluminescent properties of CdSe/ZnS colloidal quantum dots
New Mexico, University of
Estimation of the inherent optical properties of natural waters from the irradiance attenuation coefficient and
Estimation of the inherent optical properties of natural waters from the irradiance attenuation, and the backscattering bb coefficients in the upper ocean from irradiance reflectance just beneath the sea surface, R 0 , and the average attenuation coefficient for downwelling irradiance, Kd 1, between the surface and the first
Stramski, Dariusz
Thermally and optically stimulated processes in X-irradiated scheelite type crystals
Thermally and optically stimulated processes in X-irradiated scheelite type crystals M. Bohm, R at http://dx.doi.org/10.1051/jphyscol:19806132 #12;THbKMALLY AND OPTICALLY STIMULATED PROCESSES IN X-IRRADIATED and extrinsic) hole and electron centres are created by X-irradiation at liquid nitrogen temperature. Several
Microscopic mechanisms of laser ablation of organic solids in the thermal and stress confinement irradiation regimes
irradiation is defined by the combination of the optical, mechanical and thermodynamic properties irradiation regimes Leonid V. Zhigileia) and Barbara J. Garrisonb) Department of Chemistry, The Pennsylvania confinement regime results in broader velocity distributions in the direction normal to the irradiated surface
Zhigilei, Leonid V.
Photorefractive measurements in electron irradiated semi-insulating GaAs
. The native and irradiation induced defects have been assessed by electron paramagnetic resonance and optical irradiation induced defects in GaAs, we present results of electron paramagnetic resonance (EPR) and optical1 Photorefractive measurements in electron irradiated semi-insulating GaAs P. Delaye(1), H.J. von
Capillary Electrophoresis Separation of Protein Composition of c-Irradiated Food Pathogens Listeria
Capillary Electrophoresis Separation of Protein Composition of c-Irradiated Food Pathogens Listeria proteins expression which may be related to the resistance or sensitivity of food pathogens to c-irradiation Composition of c-Irradiated Food Pathogens Listeria monocytogenes and Staphylococcus aureus. PLoS ONE 7(3): e
Total Solar Irradiance Calibration Transfer Experiment/TIM Frequently Asked Questions
TCTE Total Solar Irradiance Calibration Transfer Experiment/TIM Frequently Asked Questions What is the purpose of the TCTE mission? The Total Solar Irradiance Calibration Transfer Experiment (TCTE to monitor changes in solar irradiance at the top of the Earth's atmosphere. TCTE will launch as one of five
Mojzsis, Stephen J.
A new, lower value of total solar irradiance: Evidence and climate significance
data. TIM's lower solar irradiance value is not a change in the Sun's output, whose variationsA new, lower value of total solar irradiance: Evidence and climate significance Greg Kopp1 14 January 2011. [1] The most accurate value of total solar irradiance during the 2008 solar minimum
Irradiation and annealing of p-type silicon carbide
The development of the technology of semiconductor devices based on silicon carbide and the beginning of their industrial manufacture have made increasingly topical studies of the radiation hardness of this material on the one hand and of the proton irradiation to form high-receptivity regions on the other hand. This paper reports on a study of the carrier removal rate (V{sub d}) in p-6H-SiC under irradiation with 8 MeV protons and of the conductivity restoration in radiation- compensated epitaxial layers of various p-type silicon carbide polytypes. V{sub d} was determined by analysis of capacitance-voltage characteristics and from results of Hall effect measurements. It was found that the complete compensation of samples with the initial value of Na - Nd ? 1.5 � 10{sup 18} cm{sup ?3} occurs at an irradiation dose of ?1.1 � 10{sup 16} cm{sup ?2}. It is shown that specific features of the sublimation layer SiC (compared to CVD layers) are clearly manifested upon the gamma and electron irradiation and are hardly noticeable under the proton and neutron irradiation. It was also found that the radiation-induced compensation of SiC is retained after its annealing at ?1000�C. The conductivity is almost completely restored at T ? 1200�C. This character of annealing of the radiation compensation is independent of a silicon carbide polytype and the starting doping level of the epitaxial layer. The complete annealing temperatures considerably exceed the working temperatures of SiC-based devices. It is shown that the radiation compensation is a promising method in the technology of high-temperature devices based on SiC.
Lebedev, Alexander A.; Bogdanova, Elena V.; Grigor'eva, Maria V.; Lebedev, Sergey P. [A.F. Ioffe Physical-Technical Institute, St. Petersburg, 194021 (Russian Federation); Kozlovski, Vitaly V. [St. Petersburg State Polytechnic University, St. Petersburg, 195251 (Russian Federation)
Microscopic analysis of irradiated AGR-1 coated particle fuel compacts
The AGR-1 experiment involved irradiation of 72 TRISO-coated particle fuel compacts to a peak compact-average burnup of 19.5% FIMA with no in-pile failures observed out of 3 x 105 total particles. Irradiated AGR-1 fuel compacts have been cross-sectioned and analyzed with optical microscopy to characterize kernel, buffer, and coating behavior. Six compacts have been examined, spanning a range of irradiation conditions (burnup, fast fluence, and irradiation temperature) and including all four TRISO coating variations irradiated in the AGR-1 experiment. The cylindrical specimens were sectioned both transversely and longitudinally, then polished to expose from 36 to 79 individual particles near midplane on each mount. The analysis focused primarily on kernel swelling and porosity, buffer densification and fracturing, buffer�IPyC debonding, and fractures in the IPyC and SiC layers. Characteristic morphologies have been identified, 981 particles have been classified, and spatial distributions of particle types have been mapped. No significant spatial patterns were discovered in these cross sections. However, some trends were found between morphological types and certain behavioral aspects. Buffer fractures were found in 23% of the particles, and these fractures often resulted in unconstrained kernel protrusion into the open cavities. Fractured buffers and buffers that stayed bonded to IPyC layers appear related to larger pore size in kernels. Buffer�IPyC interface integrity evidently factored into initiation of rare IPyC fractures. Fractures through part of the SiC layer were found in only four classified particles, all in conjunction with IPyC�SiC debonding. Compiled results suggest that the deliberate coating fabrication variations influenced the frequencies of IPyC fractures and IPyC�SiC debonds.
Scott A. Ploger; Paul A. Demkowicz; John D. Hunn; Jay S. Kehn
The AGR-1 experiment involved irradiation of 72 TRISO-coated particle fuel compacts to a peak burnup of 19.5% FIMA with no in-pile failures observed out of 3�105 total particles. Irradiated AGR-1 fuel compacts have been cross-sectioned and analyzed with optical microscopy to characterize kernel, buffer, and coating behavior. Five compacts have been examined so far, spanning a range of irradiation conditions (burnup, fast fluence, and irradiation temperature) and including all four TRISO coating variations irradiated in the AGR-1 experiment. The cylindrical specimens were sectioned both transversely and longitudinally, then polished to expose between approximately 40-80 individual particles on each mount. The analysis focused primarily on kernel swelling and porosity, buffer densification and fracturing, buffer-IPyC debonding, and fractures in the IPyC and SiC layers. Characteristic morphologies have been identified, over 800 particles have been classified, and spatial distributions of particle types have been mapped. No significant spatial patterns were discovered in these cross sections. However, some trends were found between morphological types and certain behavioral aspects. Buffer fractures were found in approximately 23% of the particles, and these fractures often resulted in unconstrained kernel swelling into the open cavities. Fractured buffers and buffers that stayed bonded to IPyC layers appear related to larger pore size in kernels. Buffer-IPyC interface integrity evidently factored into initiation of rare IPyC fractures. Fractures through part of the SiC layer were found in only three particles, all in conjunction with IPyC-SiC debonding. Compiled results suggest that the deliberate coating fabrication variations influenced the frequencies of IPyC fractures, IPyC-SiC debonds, and SiC fractures.
Scott Ploger; Paul Demkowicz; John Hunn; Robert Morris
Irradiation hardening and loss of ductility of type 316L(N) stainless steel plate material due to neutron-irradiation
Type 316 stainless steel is the primary candidate austenitic structural material for fusion first wall constructions. Here, type 316L(N) stainless steel plate material has been irradiated up to 10 dpa at temperatures of 80, 225, 325, and 425 C in the High Flux Reactor (HFR) of Petten. Tensile tests have been performed in the temperature range from RT to 575 C at a conventional strain rate of 5 {times} 10{sup {minus}4} s{sup {minus}1}. The results of the tensile tests are analyzed in terms of irradiation hardening and loss of ductility due to irradiation. Tensile properties saturate in the early stage (within 0.65 dpa) at the lowest applied irradiation temperature. It is indicated that the most severe degradation of tensile ductility occurs in the temperature range of 275 to 350 C. Comparison with literature data revealed a large scatter in irradiation hardening at irradiation temperatures above 325 C.
Horsten, M.G.; Vries, M.I. de [Netherlands Energy Research Foundation, Petten (Netherlands)
Irradiated Materials Testing Complex (IMTL) The Irradiated Materials Testing Laboratory provides the capability to conduct high temperature
provides the capability to conduct high temperature corrosion and stress corrosion cracking of neutron next to a hot cell. This configuration allows us to disconnect the autoclave from its water loop, maneuver it into the hot cell, where the neutron irradiated specimens can be safely mounted
Kamat, Vineet R.
Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.
The objective of this work was to characterize the neutron irradiation system consisting of americium-241 beryllium (241AmBe) neutron sources placed in a polyethylene shielding for use at Sandia National Laboratories (SNL) Low Dose Rate Irradiation Facility (LDRIF). With a total activity of 0.3 TBq (9 Ci), the source consisted of three recycled 241AmBe sources of different activities that had been combined into a single source. The source in its polyethylene shielding will be used in neutron irradiation testing of components. The characterization of the source-shielding system was necessary to evaluate the radiation environment for future experiments. Characterization of the source was also necessary because the documentation for the three component sources and their relative alignment within the Special Form Capsule (SFC) was inadequate. The system consisting of the source and shielding was modeled using Monte Carlo N-Particle transport code (MCNP). The model was validated by benchmarking it against measurements using multiple techniques. To characterize the radiation fields over the full spatial geometry of the irradiation system, it was necessary to use a number of instruments of varying sensitivities. First, the computed photon radiography assisted in determining orientation of the component sources. With the capsule properly oriented inside the shielding, the neutron spectra were measured using a variety of techniques. A N-probe Microspec and a neutron Bubble Dosimeter Spectrometer (BDS) set were used to characterize the neutron spectra/field in several locations. In the third technique, neutron foil activation was used to ascertain the neutron spectra. A high purity germanium (HPGe) detector was used to characterize the photon spectrum. The experimentally measured spectra and the MCNP results compared well. Once the MCNP model was validated to an adequate level of confidence, parametric analyses was performed on the model to optimize for potential experimental configurations and neutron spectra for component irradiation. The final product of this work is a MCNP model validated by measurements, an overall understanding of neutron irradiation system including photon/neutron transport and effective dose rates throughout the system, and possible experimental configurations for future irradiation of components.
Franco, Manuel,
Detection of toxic factors after gamma-irradiation in vitro and in vivo
its effects in the living organism. Thus, ths irradiation of pure chemlcai compounds was usecl as a first step in order to understand the stf??cts oi' irradiation in vivo. Studies of Daniel and Park (5, 6) showed that toxic factors wnlcn cause... source of gamma-irradiation. The doss rats in this study vaa constant TGG r/minute. The dose rate vas calibrated by a sliver aotixated phosphate glass dosimetry. Different, levels of irradiation vers achiewsd by expoairg the samples to ths irradiation...
Shihabi, Zakariya Kamel
Microstructure and mechanical behavior of neutron irradiated ultrafine grained ferritic steel
Neutron irradiation effects on ultra-fine grain (UFG) low carbon steel prepared by equal channel angular pressing (ECAP) has been examined. Counterpart samples with conventional grain (CG) sizes have been irradiated alongside with the UFG ones for comparison. Samples were irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to 1.24 dpa. Atom probe tomography revealed manganese, silicon-enriched clusters in both ECAP and CG steel after neutron irradiation. X-ray quantitative analysis showed that dislocation density in CG increased after irradiation. However, no significant change was observed in UFG steel revealing better radiation tolerance.
Ahmad Alsabbagh; Apu Sarkar; Brandon Miller; Jatuporn Burns; Leah Squires; Douglas Porter; James I. Cole; K. L. Murty
Origins of ion irradiation-induced Ga nanoparticle motion on GaAs surfaces
We have examined the origins of ion irradiation-induced nanoparticle (NP) motion. Focused-ion-beam irradiation of GaAs surfaces induces random walks of Ga NPs, which are biased in the direction opposite to that of ion beam scanning. Although the instantaneous NP velocities are constant, the NP drift velocities are dependent on the off-normal irradiation angle, likely due to a difference in surface non-stoichiometry induced by the irradiation angle dependence of the sputtering yield. It is hypothesized that the random walks are initiated by ion irradiation-induced thermal fluctuations, with biasing driven by anisotropic mass transport.
Kang, M.; Wu, J. H.; Chen, H. Y.; Thornton, K.; Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Sofferman, D. L. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, Adelphi University, Garden City, New York 11530-0701 (United States); Beskin, I. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)] [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)
Recent Accomplishments in the Irradiation Testing of Engineering-Scale Monolithic Fuel Specimens
The US fuel development team is focused on qualification and demonstration of the uranium-molybdenum monolithic fuel including irradiation testing of engineering-scale specimens. The team has recently accomplished the successful irradiation of the first monolithic multi-plate fuel element assembly within the AFIP-7 campaign. The AFIP-6 MKII campaign, while somewhat truncated by hardware challenges, exhibited successful irradiation of a large-scale monolithic specimen under extreme irradiation conditions. The channel gap and ultrasonic data are presented for AFIP-7 and AFIP-6 MKII, respectively. Finally, design concepts are summarized for future irradiations such as the base fuel demonstration and design demonstration experiment campaigns.
N.E. Woolstenhulme; D.M. Wachs; M.K. Meyer; H.W. Glunz; R.B. Nielson
Detection of irradiated spices using photo-stimulated luminescence technique (PSL)
Photo-stimulated luminescence (PSL) technique was applied to detect irradiated black pepper (Piper nigrum), cinnamon (Cinnamomum verum) and turmeric (Curcuma longa) after dark storage for 1 day, 3 and 6 months. Using screening and calibrated PSL, all samples were correctly discriminated between non-irradiated and spices irradiated with doses 1, 5 and 10 kGy. The PSL photon counts (PCs) of irradiated spices increased with increasing dose, with turmeric showing highest sensitivity index to irradiation compared to black pepper and cinnamon. The differences in response are possibly attributed to the varying quantity and quality of silicate minerals present in each spice sample. PSL signals of all irradiated samples reduced after 3 and 6 months storage. The results of this study provide a useful database on the applicability of PSL technique for the detection of Malaysian irradiated spices.
Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi [Faculty of Science and Technology, National University of Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Othman, Zainon; Abdullah, Wan Saffiey Wan [Malaysian Nuclear Agency, Bangi 43000 Kajang, Selangor (Malaysia)
Development of positron annihilation spectroscopy for characterizing neutron irradiated tungsten
Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500�C to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 �m and through the entire 200 �m thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.
C.N. Taylor; M. Shimada; D.W. Akers; M.W. Drigert; B.J. Merrill; Y. Hatano
Conceptual Design Report for the Irradiated Materials Characterization Laboratory (IMCL)
This document describes the design at a conceptual level for the Irradiated Materials Characterization Laboratory (IMCL) to be located at the Materials and Fuels Complex (MFC) at the Idaho National Laboratory (INL). The IMCL is an 11,000-ft2, Hazard Category-2 nuclear facility that is designed for use as a state of the-art nuclear facility for the purpose of hands-on and remote handling, characterization, and examination of irradiated and nonirradiated nuclear material samples. The IMCL will accommodate a series of future, modular, and reconfigurable instrument enclosures or caves. To provide a bounding design basis envelope for the facility-provided space and infrastructure, an instrument enclosure or cave configuration was developed and is described in some detail. However, the future instrument enclosures may be modular, integral with the instrument, or reconfigurable to enable various characterization environments to be configured as changes in demand occur. They are not provided as part of the facility.
Stephanie Austad
Advanced Post-Irradiation Examination Capabilities Alternatives Analysis Report
An alternatives analysis was performed for the Advanced Post-Irradiation Capabilities (APIEC) project in accordance with the U.S. Department of Energy (DOE) Order DOE O 413.3B, �Program and Project Management for the Acquisition of Capital Assets�. The Alternatives Analysis considered six major alternatives: ? No Action ? Modify Existing DOE Facilities � capabilities distributed among multiple locations ? Modify Existing DOE Facilities � capabilities consolidated at a few locations ? Construct New Facility ? Commercial Partnership ? International Partnerships Based on the alternatives analysis documented herein, it is recommended to DOE that the advanced post-irradiation examination capabilities be provided by a new facility constructed at the Materials and Fuels Complex at the Idaho National Laboratory.
Jeff Bryan; Bill Landman; Porter Hill
Production of sodium-22 from proton irradiated aluminum
A process for selective separation of sodium-22 from a proton irradiated minum target including dissolving a proton irradiated aluminum target in hydrochloric acid to form a first solution including aluminum ions and sodium ions, separating a portion of the aluminum ions from the first solution by crystallization of an aluminum salt, contacting the remaining first solution with an anion exchange resin whereby ions selected from the group consisting of iron and copper are selectively absorbed by the anion exchange resin while aluminum ions and sodium ions remain in solution, contacting the solution with an cation exchange resin whereby aluminum ions and sodium ions are adsorbed by the cation exchange resin, and, contacting the cation exchange resin with an acid solution capable of selectively separating the adsorbed sodium ions from the cation exchange resin while aluminum ions remain adsorbed on the cation exchange resin is disclosed.
Taylor, Wayne A. (Los Alamos, NM); Heaton, Richard C. (Los Alamos, NM); Jamriska, David J. (Los Alamos, NM)
Extending Shelf Life of Sliced Mushrooms (Agaricus bisporus) by using Vacuum Impregnation and Electron-beam Irradiation
. The best treatment was the combination of vacuum impregnation with irradiation according to the consumer studies....
Sevimli, Zeynep
Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts
The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Six irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These six compacts also included all four TRISO coating variations irradiated in the AGR experiment. The six compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. From 36 to 79 particles within each cross section were exposed near enough to midplane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 931 classified particles allowed other relationships among morphological types to be established.
Paul Demkowicz; Scott Ploger; John Hunn; Jay S. Kehn
The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Five irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These five compacts also included all four TRISO coating variations irradiated in the AGR experiment. The five compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. Approximately 40 to 80 particles within each cross section were exposed near enough to mid-plane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 830 classified particles allowed other relationships among morphological types to be established.
Paul Demkowicz; Scott Ploger; John Hunn
Method for improving performance of irradiated structural materials
Method for extending service life of nuclear reactor components prepared from ductile, high strength crystalline alloys obtained by devitrification of metallic glasses. Two variations of the method are described: (1) cycling the temperature of the nuclear reactor between the operating temperature which leads to irradiation damage and a l The U.S. Government has rights in this invention by virtue of Department of Energy, Office of Fusion Energy, Grant No. DE-AC02-78ER-10107.
Megusar, Janez (Belmont, MA); Harling, Otto K. (Hingham, MA); Grant, Nicholas J. (Winchester, MA)
Updated FY12 Ceramic Fuels Irradiation Test Plan
The Fuel Cycle Research and Development program is currently devoting resources to study of numerous fuel types with the aim of furthering understanding applicable to a range of reactors and fuel cycles. In FY11, effort within the ceramic fuels campaign focused on planning and preparation for a series of rabbit irradiations to be conducted at the High Flux Isotope Reactor located at Oak Ridge National Laboratory. The emphasis of these planned tests was to study the evolution of thermal conductivity in uranium dioxide and derivative compositions as a function of damage induced by neutron damage. Current fiscal realities have resulted in a scenario where completion of the planned rabbit irradiations is unlikely. Possibilities for execution of irradiation testing within the ceramic fuels campaign in the next several years will thus likely be restricted to avenues where strong synergies exist both within and outside the Fuel Cycle Research and Development program. Opportunities to augment the interests and needs of modeling, advanced characterization, and other campaigns present the most likely avenues for further work. These possibilities will be pursued with the hope of securing future funding. Utilization of synthetic microstructures prepared to better understand the most relevant actors encountered during irradiation of ceramic fuels thus represents the ceramic fuel campaign's most efficient means to enhance understanding of fuel response to burnup. This approach offers many of the favorable attributes embraced by the Separate Effects Testing paradigm, namely production of samples suitable to study specific, isolated phenomena. The recent success of xenon-imbedded thick films is representative of this approach. In the coming years, this strategy will be expanded to address a wider range of problems in conjunction with use of national user facilities novel characterization techniques to best utilize programmatic resources to support a science-based research program.
Nelson, Andrew T. [Los Alamos National Laboratory
Nonlinear broadband photoluminescence of graphene induced by femtosecond laser irradiation
Upon femtosecond laser irradiation, a bright, broadband photoluminescence is observed from graphene at frequencies well above the excitation frequency. Analyses show that it arises from radiative recombination of a broad distribution of nonequilibrium electrons and holes, generated by rapid scattering between photoexcited carriers within tens of femtoseconds after the optical excitation. Its highly unusual characteristics come from the unique electronic and structural properties of graphene.
Liu, Wei-Tao; Wu, S.W.; Schuck, P.J.; Salmeron, Miquel; Shen, Y.R.; Wang, F.
Structural and magnetic properties of irradiated SiC
We present a comprehensive structural characterization of ferromagnetic SiC single crystals induced by Ne ion irradiation. The ferromagnetism has been confirmed by electron spin resonance, and possible transition metal impurities can be excluded to be the origin of the observed ferromagnetism. Using X-ray diffraction and Rutherford backscattering/channeling spectroscopy, we estimate the damage to the crystallinity of SiC, which mutually influences the ferromagnetism in SiC.
Wang, Yutian; Helm, Manfred [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, P.O. Box 510119, 01314 Dresden (Germany); Technische Universit�t Dresden, 01062 Dresden (Germany); Chen, Xuliang; Yang, Zhaorong [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Lin [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, P.O. Box 510119, 01314 Dresden (Germany); Department of Physics and Electronics, School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Shalimov, Artem; Prucnal, Slawomir; Munnik, Frans; Skorupa, Wolfgang; Zhou, Shengqiang, E-mail: email@example.com [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, P.O. Box 510119, 01314 Dresden (Germany); Tong, Wei [High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China)
The U.S. Department of Energy (DOE), Office of Nuclear Energy (NE) oversees the efforts to ensure nuclear energy remains a viable option for the United States. A significant portion of these efforts are related to post-irradiation examinations (PIE) of highly activated fuel and materials that are subject to the extreme environment inside a nuclear reactor. As the lead national laboratory, Idaho National Laboratory (INL) has a rich history, experience, workforce and capabilities for performing PIE. However, new advances in tools and techniques for performing PIE now enable understanding the performance of fuels and materials at the nano-scale and smaller level. Examination at this level is critical since this is the scale at which irradiation damage occurs. The INL is on course to adopt these advanced tools and techniques to develop a comprehensive nuclear fuels and materials characterization capability that is unique in the world. Because INL has extensive PIE capabilities currently in place, a strong foundation exist to build upon as new capabilities are implemented and work load increases. In the recent past, INL has adopted significant capability to perform advanced PIE characterization. Looking forward, INL is planning for the addition of two facilities that will be built to meet the stringent demands of advanced tools and techniques for highly activated fuels and materials characterization. Dubbed the Irradiated Materials Characterization Laboratory (IMCL) and Advanced Post Irradiation Examination Capability , these facilities are next generation PIE laboratories designed to perform the work of PIE that cannot be performed in current DOE facilities. In addition to physical capabilities, INL has recently added two significant contributors to the Advanced Test Reactor-National Scientific User Facility (ATR-NSUF), Oak Ridge National Laboratory and University of California, Berkeley.
J. L. Schulthess; K. E. Rosenberg
Cation disorder in high dose neutron irradiated spinel
The crystal structures of MgAl{sub 2}O{sub 4} spinel single crystals irradiated to high neutron fluences (>5{center_dot}10{sup 26} n/m{sup 2} (E{sub n}>0.1 MeV)), were examined by neutron diffraction. Crystal structure refinement of the highest dose sample indicated that the average scattering strength of the tetrahedral crystal sites decreased by {approximately}20% while increasing by {approximately}8% on octahedral sites. Since the neutron scattering length for Mg is considerably larger than for Al, this result is consistent with site exchange between Mg{sup 2+} ions on tetrahedral sites and Al{sup 3+} ions on octahedral sites. Least squares refinements also indicated that in all irradiated samples, at least 35% of Mg{sup 2+} and Al{sup 3+} ions in the crystal experienced disordering replacements. This retained dpa on the cation sublattices is the largest retained damage ever measured in an irradiated spinel material.
Sickafus, K.E.; Larson, A.C.; Yu, N.; Nastasi, M. [Los Alamos National Lab., NM (United States); Hollenberg, G.W.; Garner, F.A. [Pacific Northwest Lab., Richland, WA (United States); Bradt, R.C. [Univ. of Nevada, Reno, NV (United States)
Cation disorder in high-dose, neutron-irradiated spinel
The objective of this effort is to determine whether MgAl{sub 2}O{sub 4} spinel is a suitable ceramic for fusion applications. Here, the crystal structures of MgAl{sub 2}O{sub 4} spinel single crystals irradiated to high neutron fluences [>5{center_dot}10{sup 26} n/m{sup 2} (E{sub n} > 0.1 MeV)] were examined by neutron diffraction. Crystal structure refinement of the highest dose sample indicated that the average scattering strength of the tetrahedral crystal sites decreased by {approximately} 20% while increasing by {approximately} 8% on octahedral sites. Since the neutron scattering length for Mg is considerably larger than for Al, this results is consistent with site exchange between Mg{sup 2+} ions on tetrahedral sites and Al{sup 3+} ions on octahedral sites. Least-squares refinements also indicated that, in all irradiated samples, at least 35% of Mg{sup 2+} and Al{sup 3+} ions in the crystal experienced disordering replacements. This retained dpa on the cation sublattices is the largest retained damage ever measured in an irradiated spinel material.
IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL
High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. UMo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.
M.K. Meyer; J. Gan; J.-F. Jue; D.D. Keiser; E. Perez; A. Robinson; D.M. Wachs; N. Woolstenhulme; G.L. Hofman; Y.-S. Kim
We present a sequence of toy models for irradiated planet atmospheres, in which the effects of geometry and energy redistribution are modelled self-consistently. We use separate but coupled grey atmosphere models to treat the ingoing stellar irradiation and outgoing planetary reradiation. We investigate how observed quantities such as full phase secondary eclipses and orbital phase curves depend on various important parameters, such as the depth at which irradiation is absorbed and the depth at which energy is redistributed. We also compare our results to the more detailed radiative transfer models in the literature, in order to understand how those map onto the toy model parameter space. Such an approach can prove complementary to more detailed calculations, in that they demonstrate, in a simple way, how the solutions change depending on where, and how, energy redistribution occurs. As an example of the value of such models, we demonstrate how energy redistribution and temperature equilibration at moderate optical depths can lead to temperature inversions in the planetary atmosphere, which may be of some relevance to recent observational findings.
Brad Hansen
Thermal Structure and Radius Evolution of Irradiated Gas Giant Planets
We consider the thermal structure and radii of strongly irradiated gas giant planets over a range in mass and irradiating flux. The cooling rate of the planet is sensitive to the surface boundary condition, which depends on the detailed manner in which starlight is absorbed and energy redistributed by fluid motion. We parametrize these effects by imposing an isothermal boundary condition $T \\equiv T_{\\rm deep}$ below the photosphere, and then constrain $T_{\\rm deep}$ from the observed masses and radii. We compute the dependence of luminosity and core temperature on mass, $T_{\\rm deep}$ and core entropy, finding that simple scalings apply over most of the relevant parameter space. These scalings yield analytic cooling models which exhibit power-law behavior in the observable age range $0.1-10 {\\rm Gyr}$, and are confirmed by time-dependent cooling calculations. We compare our model to the radii of observed transiting planets, and derive constraints on $T_{\\rm deep}$. Only HD 209458 has a sufficiently accurate radius measurement that $T_{\\rm deep}$ is tightly constrained; the lower error bar on the radii for other planets is consistent with no irradiation. More accurate radius and age measurements will allow for a determination of the correlation of $T_{\\rm deep}$ with the equilibrium temperature, informing us about both the greenhouse effect and day-night asymmetries.
Phil Arras; Lars Bildsten
Effects of mass loss for highly-irradiated giant planets
We present calculations for the evolution and surviving mass of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using a generalized scaled theory for mass loss, together with new surface-condition grids for hot EGPs and a consistent treatment of tidal truncation. Theoretical estimates for the rate of energy-limited hydrogen escape from giant-planet atmospheres differ by two orders of magnitude, when one holds planetary mass, composition, and irradiation constant. Baraffe et al. (2004, A&A 419, L13-L16) predict the highest rate, based on the theory of Lammer et al. (2003, Astrophys. J. 598, L121-L124). Scaling the theory of Watson et al. (1981, Icarus 48, 150-166) to parameters for a highly-irradiated exoplanet, we find an escape rate ~102 lower than Baraffe's. With the scaled Watson theory we find modest mass loss, occurring early in the history of a hot EGP. In this theory, mass loss including the effect of Roche-lobe overflow becomes significant primarily for masses below a Saturn mass, for semimajor axes = 0.023 AU. This contrasts with the Baraffe model, where hot EGPs are claimed to be remnants of much more massive bodies, originally several times Jupiter and still losing substantial mass fractions at present.
W. B. Hubbard; M. F. Hattori; A. Burrows; I. Hubeny; D. Sudarsky
The recent development on TEM work of irradiated RERTR fuels includes microstructural characterization of the irradiated U-10Mo/alloy-6061 monolithic fuel plate, the RERTR-7 U-7Mo/Al-2Si and U-7Mo/Al-5Si dispersion fuel plates. It is the first time that a TEM sample of an irradiated nuclear fuel was prepared using the focused-ion-beam (FIB) lift-out technical at the Idaho National Laboratory. Multiple FIB TEM samples were prepared from the areas of interest in a SEM sample. The characterization was carried out using a 200kV TEM with a LaB6 filament. The three dimensional orderings of nanometer-sized fission gas bubbles are observed in the crystalline region of the U-Mo fuel. The co-existence of bubble superlattice and dislocations is evident. Detailed microstructural information along with composition analysis is obtained. The results and their implication on the performance of these fuels are discussed.
J. Gan; B.D. Miller; D.D. Keiser Jr.; A.B. Robinson; J.W. Madden; P.G. Medvedev; D.M. Wachs
Microstructure of RERTR DU-Alloys Irradiated with Krypton Ions
Fuel development for reduced enrichment research and test reactor (RERTR) program is tasked with the development of new low enrichment uranium fuels that can be employed to replace existing high enrichment uranium fuels currently used in many research and test reactors worldwide. Radiation stability of the interaction product formed at fuel-matrix interface has a strong impact on fuel performance. Three depleted uranium alloys are cast that consist of the following 5 phases of interest to be investigated: U(Si,Al)3, (U,Mo)(Si,Al)3, UMo2Al20, U6Mo4Al43 and UAl4. Irradiation of TEM disc samples with 500 keV Kr ions at 200?C to high doses up to ~100 dpa were conducted using an intermediate voltage electron microscope equipped with an ion accelerator. The irradiated microstructure of the 5 phases is characterized using transmission electron microscopy. The results will be presented and the implication of the observed irradiated microstructure on the fuel performance will be discussed.
J. Gan; D. Keiser; D. Wachs; B. Miller; T. Allen; M. Kirk; J. Rest
Post-irradiation Examination Plan for ORNL and University of California Santa Barbara Assessment of UCSB ATR-2 Irradiation Experiment
New and existing databases will be combined to support development of physically based models of transition temperature shifts (TTS) for high fluence-low flux (? < 10{sup 11}n/cm{sup 2}-s) conditions, beyond the existing surveillance database, to neutron fluences of at least 1�10{sup 20} n/cm{sup 2} (>1 MeV). All references to neutron flux and fluence in this report are for fast neutrons (>1 MeV). The reactor pressure vessel (RPV) task of the Light Water Reactor Sustainability (LWRS) Program is working with various organizations to obtain archival surveillance materials from commercial nuclear power plants to allow for comparisons of the irradiation-induced microstructural features from reactor surveillance materials with those from similar materials irradiated under high flux conditions in test reactors
Nanstad, R. K. [Materials Science and Technology Division, Oak Ridge National Laboratory; Yamamoto, T. [University of California Santa Barbara; Sokolov, M. A. [Materials Science and Technology Division, Oak Ridge National Laboratory
Characterization of polymeric films subjected to lithium ion beam irradiation
Two different polymeric materials that are candidate materials for use as binders for mixed uranium�plutonium oxide nuclear fuel pellets were subjected to Li ion beam irradiation, in order to simulate intense alpha irradiation. The materials (a polyethylene glycol 8000 and a microcrystalline wax) were then analyzed using a combination of mass spectrometry (MS) approaches and X-ray photoelectron spectroscopy (XPS). Samples of the irradiated PEG materials were dissolved in H2O and then analyzed using electrospray ionization-MS, which showed the formation of a series of small oligomers in addition to intact large PEG oligomers. The small oligomers were likely formed by radiation-induced homolytic scissions of the C�O and C�C bonds, which furnish radical intermediates that react by radical recombination with Hradical dot and OHradical dot. Surface analysis using SIMS revealed a heterogeneous surface that contained not only PEG-derived polymers, but also hydrocarbon-based entities that are likely surface contaminants. XPS of the irradiated PEG samples indicated the emergence of different carbon species, with peak shifts suggesting the presence of sp2 carbon atoms. Analysis of the paraffinic film using XPS showed the emergence of oxygen on the surface of the sample, and also a broadening and shifting of the C1s peak, demonstrating a change in the chemistry on the surface. The paraffinic film did not dissolve in either H2O or a H2O�methanol solution, and hence the bulk of the material could not be analyzed using electrospray. However a series of oligomers was leached from the bulk material that produced ion series in the ESI-MS analyses that were identified octylphenyl ethoxylate oligomers. Upon Li ion bombardment, these shifted to a lower average molecular weight, but more importantly showed the emergence of three new ion series that are being formed as a result of radiation damage. Surface analysis of the paraffinic polymers using SIMS produced spectra that were wholly dominated by hydrocarbon ion series, and no difference was observed between unirradiated and irradiated samples. The studies demonstrate that for the PEG-based polymers, direct evidence for radiolytic scission can be observed using ESI-MS, and suggests that both radiolytic pathways and efficiencies as a function of dose should be measurable by calibrating instrument response to the small oligomeric degradation products.
Gary S. Groenewold; W. Roger Cannon; Paul A. Lessing; Recep Avci; Muhammedin Deliorman; Mark Wolfenden; Doug W. Akers; J. Keith Jewell
Cardiotoxic Effects of Tangential Breast Irradiation in Early Breast Cancer Patients: The Role of Irradiated Heart Volume
Purpose: To assess the risk of cardiovascular disease (CVD) after postlumpectomy irradiation restricted to tangential fields. Methods and Materials: We assessed the incidence of CVD in 1601 patients with T1-2N0 breast cancer (BC) treated with breast tangentials in five different hospitals between 1980 and 1993. Patients treated with radiation fields other than breast tangentials and those treated with adjuvant chemotherapy were excluded. For patients with left-sided BC, maximum heart distance (MHD) was measured on the simulator films as a proxy for irradiated heart volume. Risk of CVD by laterality and MHD categories was evaluated by Cox proportional hazards regression analysis. Results: Follow-up was complete for 94% of the patients, and median follow-up was 16 years. The incidence of CVD overall was 14.1%, of ischemic heart disease 7.3%, and for other types of heart disease 9.2%, with a median time to event of 10 to 11 years. The incidence of CVD was 11.6% in patients with right-sided BC, compared with 16.0% in left-sided cases. The hazard ratio associated with left-sided vs. right-sided BC was 1.38 (95% confidence interval [CI], 1.05-1.81) for CVD overall, 1.35 (95% CI, 0.93-1.98) for ischemic heart disease , and 1.53 (95% CI, 1.09-2.15) for other heart disease, adjusted for age, diabetes, and history of CVD. The risk of CVD did not significantly increase with increasing MHD. Conclusions: Patients irradiated for left-sided BC with tangential fields have a higher incidence of CVD compared with those with right-sided cancer. However, the risk does not seem to increase with larger irradiated heart volumes.
Borger, Jacques H. [Maastricht Radiation Oncology Clinic, Maastricht (Netherlands)], E-mail: email@example.com; Hooning, Maartje J. [Department of Epidemiology, Netherlands Cancer Institute/Antoni van Leeuwenhoek Ziekenhuis, Amsterdam (Netherlands); Boersma, Liesbeth J. [Maastricht Radiation Oncology Clinic, Maastricht (Netherlands); Snijders-Keilholz, Antonia [Department of Radiotherapy, Erasmus MC/Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Aleman, Berthe M.P. [Department of Radiotherapy, Netherlands Cancer Institute/Antoni van Leeuwenhoek Ziekenhuis, Amsterdam (Netherlands); Lintzen, Eelke [Maastricht Radiation Oncology Clinic, Maastricht (Netherlands); Brussel, Sara van [Department of Radiotherapy, Universiteitsziekenhuis, Leuven (Belgium); Toorn, Peter-Paul van der [Department of Radiotherapy, Catharina Ziekenhuis, Eindhoven (Netherlands); Alwhouhayb, Maitham [Maastricht Radiation Oncology Clinic, Maastricht (Netherlands); Leeuwen, Flora E. van [Department of Epidemiology, Netherlands Cancer Institute/Antoni van Leeuwenhoek Ziekenhuis, Amsterdam (Netherlands)
Heavy-Section Steel Irradiation Program on irradiation effects in light-water reactor pressure vessel materials
The safety of commercial light-water nuclear plants is highly dependent on the structural integrity of the reactor pressure vessel (RPV). In the absence of radiation damage to the RPV, fracture of the vessel is difficult to postulate. Exposure to high energy neutrons can result in embrittlement of radiation-sensitive RPV materials. The Heavy-Section Steel Irradiation (HSSI) Program at Oak Ridge National Laboratory, sponsored by the US Nuclear Regulatory Commission (USNRC), is assessing the effects of neutron irradiation on RPV material behavior, especially fracture toughness. The results of these and other studies are used by the USNRC in the evaluation of RPV integrity and regulation of overall nuclear plant safety. In assessing the effects of irradiation, prototypic RPV materials are characterized in the unirradiated condition and exposed to radiation under varying conditions. Mechanical property tests are conducted to provide data which can be used in the development of guidelines for structural integrity evaluations, while metallurgical examinations and mechanistic modeling are performed to improve understanding of the mechanisms responsible for embrittlement. The results of these investigations, in conjunction with results from commercial reactor surveillance programs, are used to develop a methodology for the prediction of radiation effects on RPV materials. This irradiation-induced degradation of the materials can be mitigated by thermal annealing, i.e., heating the RPV to a temperature above that of normal operation. Thus, thermal annealing and evaluation of reirradiation behavior are major tasks of the HSSI Program. This paper describes the HSSI Program activities by summarizing some past and recent results, as well as current and planned studies. 30 refs., 8 figs., 1 tab.
Nanstad, R.K.; Corwin, W.R.; Alexander, D.J.; Haggag, F.M.; Iskander, S.K.; McCabe, D.E.; Sokolov, M.A.; Stoller, R.E. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.
Booster irradiation to the spleen following total body irradiation. A new immunosuppressive approach for allogeneic bone marrow transplantation
Graft rejection presents a major obstacle for transplantation of T cell-depleted bone marrow in HLA-mismatched patients. In a primate model, after conditioning exactly as for leukemia patients, it was shown that over 99% of the residual host clonable T cells are concentrated in the spleen on day 5 after completion of cytoreduction. We have now corroborated these findings in a mouse model. After 9-Gy total body irradiation (TBI), the total number of Thy-1.2+ cells in the spleen reaches a peak between days 3 and 4 after TBI. The T cell population is composed of both L3T4 (helper) and Lyt-2 (suppressor) T cells, the former being the major subpopulation. Specific booster irradiation to the spleen (5 Gy twice) on days 2 and 4 after TBI greatly enhances production of donor-type chimera after transplantation of T cell-depleted allogeneic bone marrow. Similar enhancement can be achieved by splenectomy on day 3 or 4 after TBI but not if splenectomy is performed 1 day before TBI or 1 day after TBI, strengthening the hypothesis that, after lethal TBI in mice, the remaining host T cells migrate from the periphery to the spleen. These results suggest that a delayed booster irradiation to the spleen may be beneficial as an additional immunosuppressive agent in the conditioning of leukemia patients, in order to reduce the incidence of bone marrow allograft rejection.
Lapidot, T.; Singer, T.S.; Salomon, O.; Terenzi, A.; Schwartz, E.; Reisner, Y.
AMLR program: Ultraviolet and visible solar irradiance around Elephant Island, Antarctica, January to March 1993
Since the discovery of the seasonal ozone hole over Antarctica, great efforts have been made in measuring incident ultraviolet radiation at high latitudes in the Southern Hemisphere, as well as the impact that enhanced UV-B radiation could have on terrestrial and aquatic environments. The measurements described in this article were conducted on board the NOAA ship Surveyor. 3 refs., 3 figs.
Helbling, E.W.; Holm-Hansen, O. (Univ. of California, San Diego, La Jolla, CA (United States)); Moran, P. (Universidad Nacional del Sur, Bahia Blanca (Argentina))
The effect of neutron irradiation on the mechanical properties of C/SiC composites
The effects of neutron irradiation to 3.5 and 9.5 dpa at 730 C on a 2D plain woven carbon fiber reinforced polymer derived SiC matrix composite are presented. For both fluences, the irradiation caused in-plane contraction and trans-plane expansion. Irradiation also caused substantial reduction in composite flexural strength (54%) and increase in flexural tangent modulus (+85%). The extents of dimensional/ mechanical property changes were greater for the higher fluence irradiated samples. Those changes suggest the instability of the polymer derived SiC matrix following irradiation. The nature of the mechanical property changes suggest increased clamping stress between the fiber and the matrix. The composite property changes are explained in terms of irradiation effects on composite constituents and are compared with carbon fiber reinforced carbon matrix composite as a reference material.
Shih, Chunghao [ORNL] [ORNL; Katoh, Yutai [ORNL] [ORNL; Snead, Lance Lewis [ORNL] [ORNL; Steinbeck, John [ORNL] [ORNL
Design and Status of RERTR Irradiation Tests in the Advanced Test Reactor
Irradiation testing of U-Mo based fuels is the central component of the Reduced Enrichment for Research and Test Reactors (RERTR) program fuel qualification plan. Several RERTR tests have recently been completed or are planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory in Idaho Falls, ID. Four mini-plate experiments in various stages of completion are described in detail, including the irradiation test design, objectives, and irradiation conditions. Observations made during and after the in-reactor RERTR-7A experiment breach are summarized. The irradiation experiment design and planned irradiation conditions for full-size plate test are described. Progress toward element testing will be reviewed.
Daniel M. Wachs; Richard G. Ambrosek; Gray Chang; Mitchell K. Meyer
Effectiveness of irradiation in killing pathogens. [Treatment of sewage sludge for land application
United States Environmental Protection Agency regulations include gamma ray irradiation of sludge as an approved Process to Further Reduce Pathogens (PFRP) prior to land application. Research at Sandia National Laboratories on pathogen inactivation in sludge by gamma irradiation has demonstrated that the 1 Mrad PFRP dose is capable, by itself, of eliminating bacterial, fungal, and parasitic pathogens from sludge. Gamma irradiation of sludge in conjunction with the required Processes to Significantly Reduce Pathogens (PSRP) should also eliminate the viral hazard from wastewater sludges.
Yeager, J.G.; Ward, R.L.
Irradiation creep of nano-powder sintered silicon carbide at low neutron fluences
The irradiation creep behavior of nano-powder sintered silicon carbide was investigated using the bend stress relaxation method under neutron irradiation up to 1.9 dpa. The creep deformation was observed at all temperatures ranging from 380 to 1180 �C mainly from the irradiation creep but with the increasing contributions from the thermal creep at higher temperatures. Microstructural observation and data analysis were performed.
Koyanagi, Takaaki [ORNL; Shimoda, Kazuya [Kyoto University, Japan; Kondo, Sosuke [Kyoto University, Japan; Hinoki, Tatsuya [Kyoto University, Japan; Ozawa, Kazumi [ORNL; Katoh, Yutai [ORNL
Formation of long-range ordered quantum dots arrays in amorphous matrix by ion beam irradiation
We demonstrate the production of a well ordered three-dimensional array of Ge quantum dots in amorphous silica matrix. The ordering is achieved by ion beam irradiation and annealing of a multilayer film. Structural analysis shows that quantum dots nucleate along the direction of the ion beam used for irradiation, while the mutual distance of the quantum dots is determined by the diffusion properties of the multilayer material rather than the distances between traces of ions that are used for irradiation.
Buljan, M. [Charles University in Prague, Prague 12116 (Czech Republic); Ruder Boskovic Institute, Zagreb 10000 (Croatia); Bogdanovic-Radovic, I.; Karlusic, M.; Desnica, U. V.; Radic, N.; Dubcek, P. [Ruder Boskovic Institute, Zagreb 10000 (Croatia); Drazic, G. [Jozef Stefan Institute, Ljubljana 1000 (Slovenia); Salamon, K. [Institute of Physics, Zagreb 10000 (Croatia); Bernstorff, S. [Sincrotrone Trieste, Basovizza 34012 (Italy); Holy, V. [Charles University in Prague, Prague 12116 (Czech Republic)
Temperature dependence of fracture toughness in HT9 steel neutron-irradiated up to 145 dpa
The temperature dependence of fracture toughness in HT9 steel irradiated to high doses was investigated using miniature three-point bend (TPB) fracture specimens. These specimens were from the ACO-3 fuel duct wall of the Fast Flux Test Facility (FFTF), in which irradiation doses were in the range of 3.2 144.8 dpa and irradiation temperatures in the range of 380.4 502.6 oC. A miniature specimen reuse technique has been established for this investigation: the specimens used were the tested halves of miniature Charpy impact specimens (~13 3 4 mm) with diamond-saw cut in the middle. The fatigue precracking for specimens and fracture resistance (J-R) tests were carried out in a MTS servo-hydraulic testing machine with a vacuum furnace following the standard procedure described in the ASTM Standard E 1820-09. For each of five irradiated and one archive conditions, 7 to 9 J-R tests were performed at selected temperatures ranging from 22 C to 600 C. The fracture toughness of the irradiated HT9 steel was strongly dependent on irradiation temperatures rather than irradiation dose. When the irradiation temperature was below about 430 C, the fracture toughness of irradiated HT9 increased with test temperature, reached an upper shelf of 180 200 MPa m at 350 450 C and then decreased with test temperature. When the irradiation temperature 430 C, the fracture toughness was nearly unchanged until about 450 C and decreased with test temperature in higher temperature range. Similar test temperature dependence was observed for the archive material although the highest toughness values are lower after irradiation. Ductile stable crack growth occurred except for a few cases where both the irradiation temperature and test temperature are relatively low.
Baek, Jong-Hyuk [KAERI] [KAERI; Byun, Thak Sang [ORNL] [ORNL; Maloy, S [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Toloczko, M [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL)
ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR): irradiances
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
The multifilter rotating shadowband radiometer (MFRSR) takes spectral measurements of direct normal, diffuse horizontal and total horizontal solar irradiances. These measurements are at nominal wavelengths of 415, 500, 615, 673, 870, and 940 nm. The measurements are made at a user-specified time interval, usually about one minute or less. The sampling rate for the Atmospheric Radiation Measurement (ARM) Climate Research Facility MFRSRs is 20 seconds. From such measurements, one may infer the atmosphere's optical depth at the wavelengths mentioned above. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Michalsky et al. 1994) and other atmospheric constituents. A silicon detector is also part of the MFRSR. This detector provides a measure of the broadband direct normal, diffuse horizontal and total horizontal solar irradiances. A MFRSR head that is mounted to look vertically downward can measure upwelling spectral irradiances. In the ARM system, this instrument is called a multifilter radiometer (MFR). At the Southern Great Plains (SGP) there are two MFRs; one mounted at the 10-m height and the other at 25 m. At the North Slope of Alaska (NSA) sites, the MFRs are mounted at 10 m. MFRSR heads are also used to measure normal incidence radiation by mounting on a solar tracking device. These are referred to as normal incidence multi-filter radiometers (NIMFRs) and are located at the SGP and NSA sites. Another specialized use for the MFRSR is the narrow field of view (NFOV) instrument located at SGP. The NFOV is a ground-based radiometer (MFRSR head) that looks straight up.
Hodges, Gary
Unlike previously explored relationships between the properties of hot Jovian atmospheres, the geometric albedo and the incident stellar flux do not exhibit a clear correlation, as revealed by our re-analysis of Q0-Q14 Kepler data. If the albedo is primarily associated with the presence of clouds in these irradiated atmospheres, a holistic modeling approach needs to relate the following properties: the strength of stellar irradiation (and hence the strength and depth of atmospheric circulation), the geometric albedo (which controls both the fraction of starlight absorbed and the pressure level at which it is predominantly absorbed), and the properties of the embedded cloud particles (which determine the albedo). The anticipated diversity in cloud properties renders any correlation between the geometric albedo and the stellar flux weak and characterized by considerable scatter. In the limit of vertically uniform populations of scatterers and absorbers, we use an analytical model and scaling relations to relate the temperature-pressure profile of an irradiated atmosphere and the photon deposition layer and to estimate whether a cloud particle will be lofted by atmospheric circulation. We derive an analytical formula for computing the albedo spectrum in terms of the cloud properties, which we compare to the measured albedo spectrum of HD 189733b by Evans et al. Furthermore, we show that whether an optical phase curve is flat or sinusoidal depends on whether the particles are small or large as defined by the Knudsen number. This may be an explanation for why Kepler-7b exhibits evidence for the longitudinal variation in abundance of condensates, while Kepler-12b shows no evidence for the presence of condensates despite the incident stellar flux being similar for both exoplanets. We include an 'observer's cookbook' for deciphering various scenarios associated with the optical phase curve, the peak offset of the infrared phase curve, and the geometric albedo.
Heng, Kevin [University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Demory, Brice-Olivier, E-mail: email@example.com, E-mail: email@example.com [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
Effects of helium content of microstructural development in Type 316 stainless steel under neutron irradiation
This work investigated the sensitivity of microstructural evolution, particularly precipitate development, to increased helium content during thermal aging and during neutron irradiation. Helium (110 at. ppM) was cold preinjected into solution annealed (SA) DO-heat type 316 stainess steel (316) via cyclotron irradiation. These specimens were then exposed side by side with uninjected samples. Continuous helium generation was increased considerably relative to EBR-II irradiation by irradiation in HFIR. Data were obtained from quantitative analytical electron microscopy (AEM) in thin foils and on extraction replicas. 480 refs., 86 figs., 19 tabs.
Maziasz, P.J.
E-Print Network 3.0 - advanced alloys irradiated Sample Search...
shifts due to irradiation... on a presentation made at the 15th European Conference of Fracture "Advanced Fracture ... Source: Ecole Polytechnique, Centre de mathmatiques...
Effect of {gamma}-irradiation on strength of concrete for nuclear-safety structures
Concrete applied for construction of nuclear power plant (NPP) Temelin (Czech Republic) has been exposed to {gamma}-irradiation up to dose 6x10{sup 5} Gy. Depending on the level of irradiation, changes in strength, porous structure and phase composition of the concrete have been studied. It is found that irradiation lowers both the strength of concrete (about 10%) and volume (resp. surface) of porous space. On the other hand, {gamma}-irradiation increases the ratio of calcite, CaCO{sub 3}, in the concrete. Observed effects are discussed with respect to safety of NPPs.
Vodak, F. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Trtik, K. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Sopko, V. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Kapickova, O. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Demo, P. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic)]. E-mail: firstname.lastname@example.com
all-sky solar irradiance: Topics by E-print Network
our climate. A non-negligible influence is suggested by correlation studies between solar variability and climate indicators. The mechanism for solar irradiance variations...
E-Print Network 3.0 - acute gamma irradiation Sample Search Results
Upgraded D Detector D Collaboration Summary: is due to the bulk silicon properties, photodiode test structures from the same wafer were irradiated Source: Fermi National...
The second and third NGNP advanced gas reactor fuel irradiation experiments
The United States Dept. of Energy's Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is currently scheduled to irradiate a total of five low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The irradiations are being accomplished to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas cooled reactors. The experiments will each consist of at least six separate capsules, and will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The effluent sweep gas will also have on-line fission product monitoring to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and completed a very successful irradiation in early November 2009. The second experiment (AGR-2) started irradiation in June 2010, and the third and fourth experiments have been combined into a single larger irradiation (AGR-3/4) that is currently being assembled. The design and status of the second through fourth experiments as well as the irradiation results of the second experiment to date are discussed. (authors)
Grover, S. B.; Petti, D. A. [Idaho National Laboratory, 2525 N. Fremont Ave., Idaho Falls, ID 83415 (United States)
E-Print Network 3.0 - accidental irradiation-induced aplasia...
of Helsinki Collection: Materials Science 4 Making junctions between carbon nanotubes using an ion beam Summary: ; Ion-irradiation-induced defects; Defect annealing The...
E-Print Network 3.0 - atomic clusters irradiated Sample Search...
nanotubes encapsulating cobalt crystals Summary: to the shrinkage of the irradiated nanotubes due to atom sputtering 22 and defect migration 23... by a different mechanism...
Microsoft Word - ORNL-TM-2014-513 Status of SiC Joint Irradiation...
513 STATUS OF HIGH FLUX ISOTOPE REACTOR IRRADIATION OF SILICON CARBIDESILICON CARBIDE JOINTS Yutai Katoh Takaaki Koyanagi Jim Kiggans Nesrin Cetiner Joel McDuffee September 2014...
Accumulation and Recovery of Disorder in Au2+-Irradiated Cd2Nb2O7...
of the disorder has been observed below room temperature. Citation: Jiang W, WJ Weber, and LA Boatner.2005."Accumulation and Recovery of Disorder in Au2+-Irradiated...
114 Solar Irradiance And Power Output Variabilityand L. Bangyin. Online 24-h solar power forecasting based onNielsen. Online short-term solar power forecasting. Solar
E-Print Network 3.0 - absorbed fraction internal irradiation...
Fission and Nuclear Technologies 56 Development of a method for assessing non-targeted radiation damage in an artificial 3D human skin model Summary: partial irradiation with...
E-Print Network 3.0 - apres irradiation neutronique Sample Search...
tel-00005708,version1-5Apr2004 12;Sommaire 1 INTRODUCTION... COMPORTEMENT DES POLYMERES SOUS IRRADIATION SOUS ATMOSPHERE ANAEROBIE Source: Ecole Polytechnique, Centre de...
Advanced Numerical Weather Prediction Techniques for Solar Irradiance Forecasting : : Statistical, Data-Assimilation, and Ensemble Forecasting
United States California Solar Initiative Coastally Trappedparticipants in the California Solar Initiative (CSI)on location. In California, solar irradiance forecasts near
Mathiesen, Patrick James
A high-resolution, cloud-assimilating numerical weather prediction model for solar irradiance forecasting
is�critical�for�coastal�California�solar�forecasting. ��affecting�solar�irradiance�in�southern�California. ��solar� photovoltaic�generation�(the�southern�California�
Mathiesen, Patrick; Collier, Craig; Kleissl, Jan
alpha-particles microbeam irradiation: Topics by E-print Network
4 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...
114 Solar Irradiance And Power Output Variabilitytechniques for solar power output with no exogenous inputs.and their effect on solar power output. For large scale
E-Print Network 3.0 - accidental irradiation Sample Search Results
of materials that have been... irradiated at the Brookhaven National Laboratory (BNL) Isotope facility. The effort is part... of an experimental study that focuses on how prone to...
E-Print Network 3.0 - au ion irradiation Sample Search Results
Josephson Junctions Summary: of the Au mask after the ion irradiation. Excellent Josephson junctions and Josephson junction arrays... removal of metal mask after ion...
A Search for Channel Deformation in Irradiated Vanadium Tensile Specimens
A miniature tensile specimen of V-4Cr-4Ti which had be irradiated in the 17J test at 425�C to 3.7 dpa was mechanically polished, deformed to 3.9% strain at room temperature, and examined by scanning and transmission electron microscopy in order to look for evidence of channel deformation. It was found that uniform deformation can occur without channel deformation, but evidence for channeling was found with channels appearing most prominently after the onset of necking. The channeling occurs on wavy planes with large variations in localized deformation from channel to channel.
Gelles, David S.; Toloczko, Mychailo B.; Kurtz, Richard J.
Toward Understanding Dynamic Annealing Processes in Irradiated Ceramics
values (given in the legend in units of 1012 cm?2 s?1), and (c) with a pulsed beam with different values of toff (given in the legend in units of 10?3 s) and all the other parameters fixed (fluence = 2.4 ? 1014 cm?2, ton = 1 ms, and Fon = 1.2 ? 1013... ions does not render ZnO amorphous at RT. Ion-beam-produced disorder has been intensively investigated in ZnO [2?12]. For a wide range of irradiation conditions, the level of stable post-implantation disorder in the ZnO crystal bulk depends...
Myers, Michael
Supine Craniospinal Irradiation Setup with Two Spine Fields
Craniospinal irradiation is an integral part of treatment for a number of cancers. Typically, patients are positioned prone, which allows visualization of field matches. However, a supine position allows better airway access for patients requiring anesthesia, and is more comfortable for patients. One potential difficulty with supine positioning occurs when the patient is tall and requires matching 2 spine fields. We describe a technique to match the spine fields using light fields on the bottom of the treatment table, and verified the approach on a phantom. The accuracy of the technique is demonstrated for the first 4 patients, with the majority of field gaps and overlaps below our clinical tolerance of 2 mm.
Liu, Arthur K. [University of Colorado Denver, Department of Radiation Oncology, Aurora, Colorado (United States)], E-mail: firstname.lastname@example.com; Thornton, Dale; Backus, Jennifer; Dzingle, Wayne; Stoehr, Scott; Newman, Francis [University of Colorado Denver, Department of Radiation Oncology, Aurora, Colorado (United States)
The effects of alpha particle irradiation on stainless steel
and an approximation based on the first year's fluence. . . . . . . . . 17 CHAPTER I INTRODUCTION The storage of Weapons Grade Plutonium (WGPu) pits has prompted this study of the effects of alpha particle irradiation on stainless steel. Previous studies of alpha... and properties of WGPu. ISOTOPE Pu-239 Pu-240 P0-241 Density* Crystal Structure* ATOMIC ABD. (/o) 94. 0 5. 8 0. 2 15. 7 g/cm' BCC 'Note: The density and crystal structure of elemental plutonium is 19. 7 g/cm' and FCC, respectively...
Shipp, John Douglas
Defect studies in ion irradiated AlGaN. | EMSL
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 MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData Files Data Files 1B&W Y-12studies in ion irradiated AlGaN.
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Irradiation Effects on Microstructure Change in Nanocrystalline Ceria -
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Improving Thermal Model Prediction Through Statistical Analysis of Irradiation and Post-Irradiation Data from AGR Experiments
As part of the Research and Development program for Next Generation High Temperature Reactors (HTR), a series of irradiation tests, designated as Advanced Gas-cooled Reactor (AGR), have been defined to support development and qualification of fuel design, fabrication process, and fuel performance under normal operation and accident conditions. The AGR tests employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule and instrumented with thermocouples (TC) embedded in graphite blocks enabling temperature control. The data representing the crucial test fuel conditions (e.g., temperature, neutron fast fluence, and burnup) while impossible to obtain from direct measurements are calculated by physics and thermal models. The irradiation and post-irradiation examination (PIE) experimental data are used in model calibration effort to reduce the inherent uncertainty of simulation results. This paper is focused on fuel temperature predicted by the ABAQUS code�s finite element-based thermal models. The work follows up on a previous study, in which several statistical analysis methods were adapted, implemented in the NGNP Data Management and Analysis System (NDMAS), and applied for improving qualification of AGR-1 thermocouple data. The present work exercises the idea that the abnormal trends of measured data observed from statistical analysis may be caused by either measuring instrument deterioration or physical mechanisms in capsules that may have shifted the system thermal response. As an example, the uneven reduction of the control gas gap in Capsule 5 revealed by the capsule metrology measurements in PIE helps justify the reduction in TC readings instead of TC drift. This in turn prompts modification of thermal model to better fit with experimental data, thus help increase confidence, and in other word reduce model uncertainties in thermal simulation results of the AGR-1 test.
Dr. Binh T. Pham; Grant L. Hawkes; Jeffrey J. Einerson
Supersonic flows are expected to exist in the atmospheres of irradiated exoplanets, but the question of whether shocks develop lingers. Specifically, it reduces to whether continuous flow in a closed loop may become supersonic and if some portions of the supersonic flow steepen into shocks. We first demonstrate that continuous, supersonic flow may exist in two flavors: isentropic and non-isentropic, with shocks being included in the latter class of solutions. Supersonic flow is a necessary but insufficient condition for shocks to develop. The development of a shock requires the characteristics of neighboring points in a flow to intersect. We demonstrate that the intersection of characteristics may be quantified via the knowledge of the Mach number. Finally, we examine three-dimensional simulations of hot Jovian atmospheres and demonstrate that shock formation is expected to occur mostly on the dayside hemisphere, upstream of the substellar point, because the enhanced temperatures near the substellar point provide a natural pressure barrier for the returning flow. Understanding the role of shocks in irradiated exoplanetary atmospheres is relevant to correctly modeling observables such as the peak offsets of infrared phase curves.
Heng, Kevin [Institute for Astronomy, ETH Zuerich, Wolfgang-Pauli-Strasse 27, CH-8093 Zuerich (Switzerland)
Irradiation testing of a niobium-molybdenum developmental thermocouple
A need exists for a radiation-resistant thermocouple capable of monitoring temperatures in excess of the limits of the chromel/alumel system. Tungsten/rhenium and platinum/rhodium thermocouples have sufficient temperature capability but have proven to be unstable because of irradiation-induced decalibration. The niobium/molybdenum system is believed to hold great potential for nuclear applications at temperatures up to 2000 K. However, the fragility of pure niobium and fabrication problems with niobium/molybdenum alloys have limited development of this system. Utilizing the Fast Flux Test Facility, a developmental thermocouple with a thermoelement pair consisting of a pure molybdenum and a niobium-1%zirconium alloy wire was irradiated fro 7200 hours at a temperature of 1070 K. The thermocouple performed flawlessly for the duration of the experiment and exhibited stability comparable to a companion chromel/alumel unit. A second thermocouple, operating at 1375 K, is currently being employed to monitor a fusion materials experiment in the Fast Flux Test Facility. This experiment, also scheduled for 7200 hours, will serve to further evaluate the potential of the niobium-1%zirconium/molybdenum thermoelement system. 7 refs., 7 figs.
Knight, R.C.; Greenslade, D.L.
Simulation of Electron-Beam Irradiation of Skin Tissue Model
Monte Carlo simulation of electrons stopping in liquid water was used to model the penetration and dose distribution of electron beams incident on the full-thickness EpiDermTM skin model (MatTek, Ashland, VA). This 3D tissue model has a fully developed basement membrane separating an epidermal layer of keratinocytes in various stages of differentiation from a dermal layer of fibroblast embedded in collagen. The simulations were motivated by a desire to selectively expose the epidermal layer to low linear-energy-transfer (LET) radiation in the presence of a non-irradiated dermal layer. Using the variable energy electron microbeam at the Pacific Northwest National Laboratory (PNNL) as a model of device characteristics and irradiation geometry, we find that at the highest beam energy available (90 keV), the estimated 90th percentile of penetration remains in the epidermal layer. To investigate the depth-dose distribution, we calculated lineal energy spectra for 10um thick layers near the 10th, 50th, and 90th percentile of penetration by the 90 keV electron beam. Biphasic spectra showed an increasing component of "stoppers" with increasing depth. Despite changes in the lineal energy spectra, the main effect on dose deposition with increasing depth is the screening effect of tissue above the layer of interest.
Miller, John H.; Suleiman, Atef; Chrisler, William B.; Sowa, Marianne B.
Janus Experiments: Data from Mouse Irradiation Experiments 1972 - 1989
The Janus Experiments, carried out at Argonne National Laboratory from 1972 to 1989 and supported by grants from the US Department of Energy, investigated the effects of neutron and gamma radiation on mouse tissues primarily from B6CF1 mice. 49,000 mice were irradiated: Death records were recorded for 42,000 mice; gross pathologies were recorded for 39,000 mice; and paraffin embedded tissues were preserved for most mice. Mouse record details type and source of radiation [gamma, neutrons]; dose and dose rate [including life span irradiation]; type and presence/absence of radioprotector treatment; tissue/animal morphology and pathology. Protracted low dose rate treatments, short term higher dose rate treatments, variable dose rates with a same total dose, etc. in some cases in conjunction with radioprotectors, were administered. Normal tissues, tumors, metastases were preserved. Standard tissues saved were : lung, liver, spleen, kidney, heart, any with gross lesions (including mammary glands, Harderian gland with eye, adrenal gland, gut, ovaries or testes, brain and pituitary, bone). Data are searchable and specimens can be obtained by request.
Global horizontal irradiance clear sky models : implementation and analysis.
Clear sky models estimate the terrestrial solar radiation under a cloudless sky as a function of the solar elevation angle, site altitude, aerosol concentration, water vapor, and various atmospheric conditions. This report provides an overview of a number of global horizontal irradiance (GHI) clear sky models from very simple to complex. Validation of clear-sky models requires comparison of model results to measured irradiance during clear-sky periods. To facilitate validation, we present a new algorithm for automatically identifying clear-sky periods in a time series of GHI measurements. We evaluate the performance of selected clear-sky models using measured data from 30 different sites, totaling about 300 site-years of data. We analyze the variation of these errors across time and location. In terms of error averaged over all locations and times, we found that complex models that correctly account for all the atmospheric parameters are slightly more accurate than other models, but, primarily at low elevations, comparable accuracy can be obtained from some simpler models. However, simpler models often exhibit errors that vary with time of day and season, whereas the errors for complex models vary less over time.
Stein, Joshua S.; Hansen, Clifford W.; Reno, Matthew J.
Method for monitoring irradiated fuel using Cerenkov radiation
A method is provided for monitoring irradiated nuclear fuel inventories located in a water-filled storage pond wherein the intensity of the Cerenkov radiation emitted from the water in the vicinity of the nuclear fuel is measured. This intensity is then compared with the expected intensity for nuclear fuel having a corresponding degree of irradiation exposure and time period after removal from a reactor core. Where the nuclear fuel inventory is located in an assembly having fuel pins or rods with intervening voids, the Cerenkov light intensity measurement is taken at selected bright sports corresponding to the water-filled interstices of the assembly in the water storage, the water-filled interstices acting as Cerenkov light channels so as to reduce cross-talk. On-line digital analysis of an analog video signal is possible, or video tapes may be used for later measurement using a video editor and an electrometer. Direct measurement of the Cerenkov radiation intensity also is possible using spot photometers pointed at the assembly.
Dowdy, E.J.; Nicholson, N.; Caldwell, J.T.
The effect of neutron irradiation on silicon carbide fibers
Nine types of SiC fiber have been exposed to neutron radiation in the Advanced Test Reactor at 250 C for various lengths of time ranging from 83 to 128 days. The effects of these exposures have been initially determined using scanning electron microscopy. The fibers tested were Nicalon{trademark} CG, Tyranno, Hi-Nicalon{trademark}, Dow Corning SiC, Carborundum SiC, Textron SCS-6, polymethysilane (PMS) derived SiC from the University of Michigan, and two types of MER SiC fiber. This covers a range of fibers from widely used commercial fibers to developmental fibers. Consistent with previous radiation experiments, Nicalon fiber was severely degraded by the neutron irradiation. Similarly, Tyranno suffered severe degradation. The more advanced fibers which approach the composition and properties of SiC performed well under irradiation. Of these, the Carborundum SiC fiber appeared to perform the best. The Hi-Nicalon and Dow Corning Fibers exhibited good general stability, but also appear to have some surface roughening. The MER fibers and the Textron SCS-6 fibers both had carbon cores which adversely influenced the overall stability of the fibers.
Newsome, G.A. [Lockheed Martin Corp., Schenectady, NY (United States)
Status of the NGNP fuel experiment AGR-2 irradiated in the advanced test reactor
The United States Department of Energy's Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States, and will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of at least six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also undergo on-line fission product monitoring to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2), which utilized the same experiment design as well as control and monitoring systems as AGR-1, started irradiation in June 2010 and is currently scheduled to be completed in April 2013. The design of this experiment and sup
S. Blaine Grover; David A. Petti
Is irradiation important for the secular evolution of low-mass X-ray binaries?
It is argued that irradiation in low-mass X-ray binaries (LMXBs) caused by accretion-generated X-rays can not only change the optical appearance of LMXBs but also their outburst properties and possibly also their long-term evolution. Irradiation during an outburst of the outer parts of the accretion disc in a transient LMXB leads to drastic changes in the outburst properties. As far as the secular evolution of such systems is concerned, these changes can result in enhanced loss of mass and angular momentum from the system and, most important, in neutron star LMXBs in a much less efficient use of the transferred matter to spin up the neutron star to a ms-pulsar. Irradiation of the donor star can destabilize mass transfer and lead to irradiation-driven mass transfer cycles, i.e. to a secular evolution which differs drastically from an evolution in which irradiation is ignored. It is argued that irradiation-driven mass transfer cycles cannot occur in systems which are transient because of disc instabilities, i.e. in particular in long-period LMXBs with a giant donor. It is furthermore shown that for irradiating either the disc or the donor star, direct irradiation alone is insufficient. Rather, indirect irradiation via scattered accretion luminosity must play an important role in transient LMXBs and is, in fact, necessary to destabilize mass transfer in short-period systems by irradiating the donor star. Whether and to what extent irradiation in LMXBs does change their secular evolution depends on a number of unsolved problems which are briefly discussed at the end of this article.
H. Ritter
Status of the NGNP Fuel Experiment AGR-2 Irradiated in the Advanced Test Reactor
The United States Department of Energy�s Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States, and will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of at least six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2), which utilized the same experiment design as well as control and monitoring systems as AGR-1, started irradiation in June 2010 and is currently scheduled to be completed in April 2013. The design of this experiment and support systems will be briefly discussed, followed by the progress and status of the experiment to date.
Blaine Grover
Effects of neutron irradiation on thermal conductivity of SiC-based composites and monolithic ceramics
A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation of irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.
Senor, D.J.; Youngblood, G.E. [Pacific Northwest National Lab., Richland, WA (United States); Moore, C.E. [Auburn Univ., AL (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)
A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation after irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.
20th century changes in surface solar irradiance in simulations and observations
20th century changes in surface solar irradiance in simulations and observations A. Romanou,1 B December 2006; accepted 5 February 2007; published 8 March 2007. [1] The amount of solar irradiance reaching the surface is a key parameter in the hydrological and energy cycles of the Earth's climate. We
Irradiation research capabilities at HFIR (High Flux Isotope Reactor) and ANS (Advanced Neutron Source)
A variety of materials irradiation facilities exist in the High Flux Isotope Reactor (HFIR) and are planned for the Advanced Neutron Source (ANS) reactor. In 1986 the HFIR Irradiation Facilities Improvement (HIFI) project began modifications to the HFIR which now permit the operation of two instrumented capsules in the target region and eight capsules of 46-mm OD in the RB region. Thus, it is now possible to perform instrumented irradiation experiments in the highest continuous flux of thermal neutrons available in the western world. The new RB facilities are now large enough to permit neutron spectral tailoring of experiments and the modified method of access to these facilities permit rotation of experiments thereby reducing fluence gradients in specimens. A summary of characteristics of irradiation facilities in HFIR is presented. The ANS is being designed to provide the highest thermal neutron flux for beam facilities in the world. Additional design goals include providing materials irradiation and transplutonium isotope production facilities as good, or better than, HFIR. The reference conceptual core design consists of two annular fuel elements positioned one above the other instead of concentrically as in the HFIR. A variety of materials irradiation facilities with unprecedented fluxes are being incorporated into the design of the ANS. These will include fast neutron irradiation facilities in the central hole of the upper fuel element, epithermal facilities surrounding the lower fuel element, and thermal facilities in the reflector tank. A summary of characteristics of irradiation facilities presently planned for the ANS is presented. 2 tabs.
Thoms, K.R.
Antimicrobial packaging system for optimization of electron beam irradiation of fresh produce
This study evaluated the potential use of an antimicrobial packaging system in combination with electron beam irradiation to enhance quality of fresh produce. Irradiated romaine lettuce up to 3.2 kGy showed negligible (p > 0.05) changes in color...
Han, Jaejoon
P5.60B DERIVATION OF DAYLIGHT AND SOLAR IRRADIANCE DATA FROM SATELLITE OBSERVATIONS A. Hammer, D project SATELLIGHT an attempt is made to use satellite methods to derive daylight and solar irradiance). In daylighting applications, knowledge of the lumi- nance distribution of the sky is of primary concern. Thus
Stability of irradiation-induced point defects on walls of carbon nanotubes
Stability of irradiation-induced point defects on walls of carbon nanotubes A. V. Krasheninnikov #3 of atomic-scale irradiation- induced defects on walls of carbon nanotubes. Since atomic vacancies. Carbon nanotubes; C. Computational chemistry; Scanning tunneling microscopy; D. Defects; Electronic
Ion-irradiation-induced welding of carbon nanotubes A. V. Krasheninnikov, K. Nordlund, and J. Keinonen
been suggested16 to use a low-energy 3 eV bombardment of crossed nanotubes with carbon ions to formIon-irradiation-induced welding of carbon nanotubes A. V. Krasheninnikov, K. Nordlund, and J, electron irradiation can be used to create molecular junctions between carbon nanotubes. Employing
Microstructural changes induced by low energy heavy ion irradiation in titanium silicon carbide
Microstructural changes induced by low energy heavy ion irradiation in titanium silicon carbide, and it was validated on irradiated silicon carbide. The swelling of Ti3SiC2 was estimated to 2.2 ±0 to these working conditions, non-oxide refractory ceramics are required as fuel cladding. Thus, carbides turn out
Incident and in situ irradiance in Lakes Cadagno and Lucerne: A comparison of methods and models
Incident and in situ irradiance in Lakes Cadagno and Lucerne: A comparison of methods and models Key words: Lake Lucerne, Lake Cadagno, PAR, UV-A, UV-B, irradiance regime, radiative transfer models) at the field stations Kastanienbaum at Lake Lucerne (434 m a.s.l.) and Piora at Lake Cadagno (1923 m a
Sommaruga, Ruben
Warm photoionized plasmas created by soft-x-ray laser irradiation of solid targets
Warm photoionized plasmas created by soft-x-ray laser irradiation of solid targets Mark Berrill,1); published April 7, 2008 We report the study of warm plasmas created by soft-x-ray laser irradiation of solid that in contrast to plasmas created by optical lasers the plasma properties are largely determined
Rocca, Jorge J.
Irradiation of Dye-Doped Microspheres with a Strongly Focused Laser Beam
Irradiation of Dye-Doped Microspheres with a Strongly Focused Laser Beam Results in Alignment upon Optical Trapping Garth J. Simpson, Thorsten Wohland, and Richard N. Zare* Department of Chemistry Received December 12, 2001 ABSTRACT The irradiation of dye-doped polystyrene microspheres with an argon ion
Zare, Richard N.
Deformation patterns in thin films under uniform laser irradiation D. Walgraef
Deformation patterns in thin films under uniform laser irradiation D. Walgraef Mechanical to laser irradiation is described by a dynamical model that is based on coupled evolution equations la- ser damage of optical components, and nonuniform melting of semiconductor surfaces, to cite only
Ghoniem, Nasr M.
Phonons in thin optically irradiated superconductors ; spectrum and possible definition of a phonon temperature
615 Phonons in thin optically irradiated superconductors ; spectrum and possible definition supraconducteur en présence d'une irradiation optique pour différentes intensités de la lumière. Nous effec- tuons of the coupled-quasiparticle pair phonon system in a superconducting film in the présence of an optical
Imaging the irradiance distribution in the optical near field J. Aizenberg,a)
Imaging the irradiance distribution in the optical near field J. Aizenberg,a) J. A. Rogers, K. E of the irradiance distribution in the optical near field for contact-mode photolithography using elastomeric phase of a sensitive photoresist for direct imaging of optical intensity profiles in near-field photolithographic
Prentiss, Mara
Nov. 21, 1999 Neutron Irradiation Tests of an S-LINK-over-G-link System
Nov. 21, 1999 Neutron Irradiation Tests of an S-LINK-over-G-link System K. Anderson, J. Pilcher, H, MD 1. Objective This note describes neutron irradiation tests of an S-LINK [1] source card (LSC/1024 transmitter/receiver chips operated in 20-bit, single frame mode with a 40 MHz clock. The optical transmitter
Simultaneous retrievals of column ozone and aerosol optical properties from direct and diffuse solar irradiance measurements
of column ozone and aerosol optical properties from direct and diffuse solar irradiance measurements, JSimultaneous retrievals of column ozone and aerosol optical properties from direct and diffuse solar irradiance measurements Christian D. Goering,1 Tristan S. L'Ecuyer,1 Graeme L. Stephens,1 James R
Stephens, Graeme L.
Mechanism of Elongation of Gold or Silver Nanoparticles in Silica by Irradiation with Swift Heavy Ions
1 Mechanism of Elongation of Gold or Silver Nanoparticles in Silica by Irradiation with Swift Heavy nanoparticles oriented parallel to one another can be synthesized in SiO2 by ion irradiation. Our aim, silica glass 1. Introduction Well-defined Au nanoparticles and nanorods are desirable for their optical
Irradiation and Potassium Sorbate Compared as Preservation Treatments for Atlantic Cod, Gadus morhua
Irradiation and Potassium Sorbate Compared as Preservation Treatments for Atlantic Cod, Gadus for seafood applications pending approval by the U.S. Food and Drug Administration (FDA). Various chemicals of these two seafood preserva- tion methods (irradiation vs. sorbate ABSTRACT-Treatments offresh Atlantic cod
EFFECT OF EXCIMER LASER IRRADIATION OF BIODEGRADABLE POLYMER ON ITS CHEMICAL BONDING Paper M1306 profile is favorable for surface treatment. The effects of excimer laser irradiation on the surface to their biocompatibility and biodegradability. Being biodegradable, poly lactic acid (PLA) is used in food packaging
Yao, Y. Lawrence
Principal Investigator: Guerrero, Thomas TITLE: Oral antisense oligonucleotides to mitigate GI crypt survival post-irradiation
GI crypt survival post-irradiation A. SPECIFIC AIMS Gastrointestinal (GI) injury is a major cause and contributor of death after whole-body irradiation (Jarrett 1999; NCRP 2001), agents to mitigate the effects of antisense oligonucleotide drugs. Isis Pharmaceuticals was the first to secure Food and Drug Administration
Warren, Joe
mock fish before in irradiation studies in which we either embedded the inoculum evenly throughout
mock fish before in irradiation studies in which we either embedded the inoculum evenly throughout., AND J. D. KAYLOR. 1977. Variations in the microbial log reduction curves of irradiated cod fillets. The effectiveness of EDTA as a fish preserva- tive. J. Milk Food Technol. 30:277-2B3. WINARINO, F. G., C. R. STUMBO
Irradiation requirements of Nb3Sn based SC magnets electrical insulation
Irradiation requirements of Nb3Sn based SC magnets electrical insulation developed within the Eu electrical insulation candidates � EuCARD insulators certification conditions � Post irradiation tests and neutrino factories will be subjected to very high radiation doses. � The electrical insulation employed
The Columbia University microbeam II endstation for cell imaging and irradiation
The Columbia University microbeam II endstation for cell imaging and irradiation A.W. Bigelow *, G.J. Ross, G. Randers-Pehrson, D.J. Brenner Columbia University, Radiological Research Accelerator Facility The Columbia University Microbeam II has been built to provide a focused ion beam for irradiating designated
Irradiation effects on base metal and welds of 9Cr-1Mo (EM10) martensitic steel
9Cr martensitic steels are being developed for core components (wrapper tubes) of fast breeder reactors as well as for fusion reactor structures. Here, the effects of fast neutron irradiation on the mechanical behavior of base metal and welds of 9Cr-1Mo (EM10) martensitic steel have been studied. Two types of weldments have been produced by TIG and electron beam techniques. Half of samples have been post-weld heat treated to produce a stress-relieved structure. The irradiation has been conducted in the Phenix reactor to doses of 63--65 dpa in the temperature range 450--459 C. The characterization of the welds, before and after irradiation, includes metallographic observations, hardness measurements, tensile and Charpy tests. It is shown that the mechanical properties of the welds after irradiation are in general similar to the characteristics obtained on the base metal, which is little affected by neutron irradiation.
Alamo, A.; Seran, J.L.; Rabouille, O.; Brachet, J.C.; Maillard, A.; Touron, H.; Royer, J. [CEA Saclay, Gif-sur-Yvette (France)
Attachment of Salmonella on cantaloupe and effect of electron beam irradiation on quality and safety of sliced cantaloupe
effectively by irradiation but there was no significant effect on reduction of yeasts. Our results show that electron beam irradiation in combination with chemical sanitizers is effective in decontamination of fresh-cut produce. Electron microscopy images...
Palekar, Mangesh Prafull
Irradiation damage of single crystal, coarse-grained, and nanograined copper under helium bombardment at 450 �C
The irradiation damage behaviors of single crystal (SC), coarse-grained (CG), and nanograined (NG) copper (Cu) films were investigated under Helium (He) ion implantation at 450 �C with different ion fluences. In irradiated ...
Han, Weizhong
Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain
Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy {gamma}-rays or a fractionated dose of 40 Gy {gamma}-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.
Lee, Won Hee [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Warrington, Junie P.; Sonntag, William E. [Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Lee, Yong Woo, E-mail: firstname.lastname@example.com [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States)
Standard practice for dosimetry in electron beam and X-Ray (Bremsstrahlung) irradiation facilities for food processing
Standard practice for dosimetry in electron beam and X-Ray (Bremsstrahlung) irradiation facilities for food processing
International Organization for Standardization. Geneva
Irradiation behavior of pressurized water reactor control materials
Postirradiation examinations have been conducted as part of an extensive Babcock and Wilcox (B and W) program in reactor control materials performance characterization. These examinations of fixed burnable poison rods and control rods confirmed operational performance and extended the material behavior data base for irradiated absorber materials used in B and W-designed pressurized water reactors. These examinations included visual, dimensional, and destructive examinations. They were conducted at B and W's Lynchburg Research Center hot cell facilities on Ag-In-Cd control rods. Al/sub 2/O/sub 3/-B/sub 4/C burnable poison rods, and B/sub 4/C control rods. The visual and dimensional exams revealed no discernible exterior damage on any of these components. Destructive examinations provided data on absorber swelling, gas release, and open porosity.
Demars, R.V.; Dideon, C.G.; Pardue, E.B.S.; Pavinich, W.A.; Thornton, T.A.; Tulenko, J.S.
Etch rate modeling for ion-irradiated nitrocellulose
The self-developing mechanism of nitrocellulose when used as an ion beam resist is described by a model predicting the evolution of the etch rate versus irradiation time. Fundamentals of the model based on ion energy deposition dependent ablative development along with related mathematical derivations are given and briefly discussed. Comparison between theoretical results and experimental data available for protons at 20 keV and Ne{sup +}, Ar{sup +}, Kr{sup +} ions at 150 keV is made and shows a good agreement. This result clearly does not conflict with our assumption that the nitrocellulose etch rate is dependent on the total ion deposited energy no matter how the energy is deposited.
Merhari, L.; Belorgeot, C.; Moliton, J.P. (Laboratoire d'electronique des Polymeres sous Faisceaux Ioniques, 123, Avenue Albert Thomas, 87060 Limoges Cedex (France))
Radiation effects on microstructures and properties of irradiated materials
Development of structural materials to withstand aggressive radiation environments has been carried out on an international scale over the past four decades. Major radiation-induced changes in properties include swelling, creep and embrittlement. The basic work, stimulated by technology, to understand and control these phenomena, has been heavily oriented toward the evolution of microstructures and their effects on properties. Microstructural research has coupled analyses by high resolution techniques with theoretical modeling to describe and predict microscopic features and the resulting macroscopic properties. A short summary is presented of key physical considerations that drive these changes during irradiation. Such processes begin with displacement cascades, and lead to property changes through the diffusion and clustering of defects.
Mansur, L.K.
Impact of electron irradiation on electron holographic potentiometry
While electron holography in the transmission electron microscope offers the possibility to measure maps of the electrostatic potential of semiconductors down to nanometer dimensions, these measurements are known to underestimate the absolute value of the potential, especially in GaN. We have varied the dose rates of electron irradiation over several orders of magnitude and observed strong variations of the holographically detected voltages. Overall, the results indicate that the electron beam generates electrical currents within the specimens primarily by the photovoltaic effect and due to secondary electron emission. These currents have to be considered for a quantitative interpretation of electron holographic measurements, as their negligence contributes to large parts in the observed discrepancy between the measured and expected potential values in GaN.
Park, J. B.; Niermann, T.; Lehmann, M. [Technische Universit�t Berlin, Institut f�r Optik und Atomare Physik, Stra�e des 17. Juni 135, 10623 Berlin (Germany); Berger, D. [Technische Universit�t Berlin, Zentraleinrichtung f�r Elektronenmikroskopie, Strae des 17. Juni 135, 10623 Berlin (Germany); Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibnitz-Institut f�r H�chstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Koslow, I.; Kneissl, M. [Ferdinand-Braun-Institut, Leibnitz-Institut f�r H�chstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Technische Universit�t Berlin, Institut f�r Festk�rperphysik, Hardenbergstr. 36, 10623 Berlin (Germany)
The AFIP-6 test assembly was irradiated for one cycle in the Advanced Test Reactor at Idaho National Laboratory. The experiment was designed to test two monolithic fuel plates at power and burn-ups which bounded the operating conditions of both ATR and HFIR driver fuel. Both plates contained a solid U-Mo fuel foil with a zirconium diffusion barrier between 6061-aluminum cladding plates bonded by hot isostatic pressing. The experiment was designed with an orifice to restrict the coolant flow in order to obtain prototypic coolant temperature conditions. While these coolant temperatures were obtained, the reduced flow resulted in a sufficiently low heat transfer coefficient that failure of the fuel plates occurred. The increased fuel temperature led to significant variations in the fission gas retention behaviour of the U-Mo fuel. These variations in performance are outlined herein.
A. B. Robinson; D. M. Wachs; P. Medvedev; S.J. Miller; F. J. Rice; M. K. Meyer; D. M. Perez
Thermal Analysis of a Uranium Silicide Miniplate Irradiation Experiment
This paper outlines the thermal analysis for the irradiation of high density uranium-silicide (U3Si2 dispersed in an aluminum matrix and clad in aluminum) booster fuel for a Boosted Fast Flux Loop designed to provide fast neutron flux test capability in the ATR. The purpose of this experiment (designated as Gas Test Loop-1 [GTL-1]) is two-fold: (1) to assess the adequacy of the U3Si2/Al dispersion fuel and the aluminum alloy 6061 cladding, and (2) to verify stability of the fuel cladding boehmite pre-treatment at nominal power levels in the 430 to 615 W/cm2 (2.63 to 3.76 Btu/s�in2) range. The GTL-1 experiment relies on a difficult balance between achieving a high heat flux, yet keeping fuel centerline temperature below a specified maximum value throughout an entire operating cycle of the reactor. A detailed finite element model was constructed to calculate temperatures and heat flux levels and to reveal which experiment parameters place constraints on reactor operations. Analyses were performed to determine the bounding lobe power level at which the experiment could be safely irradiated, yet still provide meaningful data under nominal operating conditions. Then, simulations were conducted for nominal and bounding lobe power levels under steady-state and transient conditions with the experiment in the reactor. Reactivity changes due to a loss of commercial power with pump coast-down to emergency flow or a standard in-pile tube pump discharge break were evaluated. The time after shutdown for which the experiment can be adequately cooled by natural convection cooling was determined using a system thermal hydraulic model. An analysis was performed to establish the required in-reactor cooling time prior to removal of the experiment from the reactor. The inclusion of machining tolerances in the numerical model has a large effect on heat transfer.
Donna Post Guillen
High dose rate intraluminal irradiation in recurrent endobronchial carcinoma
Palliative therapy for previously irradiated patients with symptomatic recurrent endobronchial malignancy is a difficult problem. We have had the opportunity to treat 20 such patients with high dose rate (50-100 rad/min) endobronchial brachytherapy. Eligible patients had received previous high dose thoracic irradiation (TDF greater than or equal to 90), a performance status of greater than or equal to 50, and symptoms caused by a bronchoscopically defined and implantable lesion. The radiation is produced by a small cobalt-60 source (0.7 Ci) remotely afterloaded by cable control. The source is fed into a 4 mm diameter catheter which is placed with bronchoscopic guidance; it may oscillate if necessary to cover the lesion. A dose of 1,000 rad at 1 cm from the source is delivered. We have performed 22 procedures in 20 patients, four following YAG laser debulking. Most had cough, some with hemoptysis. Eight had dyspnea secondary to obstruction and three had obstructive pneumonitis. In 12, symptoms recurred with a mean time to recurrence of 4.3 months (range 1-9 months). Eighteen patients were followed-up and reexamined via bronchoscope 1-2.5 months following the procedure; two were lost to follow-up. All had at least 50 percent clearance of tumor, and six had complete clearance; most regressions were documented on film or videotape. In six, the palliation was durable. The procedure has been well tolerated with no toxicity. We conclude that palliative endobronchial high dose rate brachytherapy is a useful palliative modality in patients with recurrent endobronchial symptomatic carcinoma.
Seagren, S.L.; Harrell, J.H.; Horn, R.A.
Mechanism of Irradiation Assisted Cracking of Core Components in Light Water Reactors
The overall goal of the project is to determine the mechanism of irradiation assisted stress corrosion cracking (IASCC). IASCC has been linked to hardening, microstructural and microchemical changes during irradiation. Unfortunately, all of these changes occur simultaneously and at similar rates during irradiation, making attribution of IASCC to any one of these features nearly impossible to determine. The strategy set forth in this project is to develop means to separate microstructural from microchemical changes to evaluate each separately for their effect on IASCC. In the first part, post irradiation annealing (PIA) treatments are used to anneal the irradiated microstructure, leaving only radiation induced segregation (RIS) for evaluation for its contribution to IASCC. The second part of the strategy is to use low temperature irradiation to produce a radiation damage dislocation loop microstructure without radiation induced segregation in order to evaluate the effect of the dislocation microstructure alone. A radiation annealing model was developed based on the elimination of dislocation loops by vacancy absorption. Results showed that there were indeed, time-temperature annealing combinations that leave the radiation induced segregation profile largely unaltered while the dislocation microstructure is significantly reduced. Proton irradiation of 304 stainless steel irradiated with 3.2 MeV protons to 1.0 or 2.5 dpa resulted in grain boundary depletion of chromium and enrichment of nickel and a radiation damaged microstructure. Post irradiation annealing at temperatures of 500 ? 600�C for times of up to 45 min. removed the dislocation microstructure to a greater degree with increasing temperatures, or times at temperature, while leaving the radiation induced segregation profile relatively unaltered. Constant extension rate tensile (CERT) experiments in 288�C water containing 2 ppm O2 and with a conductivity of 0.2 mS/cm and at a strain rate of 3 x 10-7 s-1 showed that the IASCC susceptibility, as measured by the crack length per unit strain, decreased with very short anneals and was almost completely removed by an anneal at 500�C for 45 min. This annealing treatment removed about 15% of the dislocation microstructure and the irradiation hardening, but did not affect the grain boundary chromium depletion or nickel segregation, nor did it affect the grain boundary content of other minor impurities. These results indicate that RIS is not the sole controlling feature of IASCC in irradiated stainless steels in normal water chemistry. The isolation of the irradiated microstructure was approached using low temperature irradiation or combinations of low and high temperature irradiations to achieve a stable, irradiated microstructure without RIS. Experiments were successful in achieving a high degree of irradiation hardening without any evidence of RIS of either major or minor elements. The low temperature irradiations to doses up to 0.3 dpa at T<75�C were also very successful in producing hardening to levels considerably above that for irradiations conducted under nominal conditions of 1 dpa at 360�C. However, the microstructure consisted of an extremely fine dispersion of defect clusters of sizes that are not resolvable by either transmission electron microscopy (TEM) or small angle x-ray scattering (SAXS). The microstructure was not stable at the 288�C IASCC test temperature and resulted in rapid reduction of hardening and presumably, annealing of the defect clusters at this temperature as well. Nevertheless, the annealing studies showed that treatments that resulted in significant decreases in the hardening produced small changes in the dislocation microstructure that were confined to the elimination of the finest of loops (~1 nm). These results substantiate the importance of the very fine defect microstructure in the IASCC process. The results of this program provide the first definitive evidence that RIS is not the sole controlling factor in the irradiation assisted stress corrosion cracking of austenitic stain
Gary S. Was; Michael Atzmon; Lumin Wang
High swelling rates observed in neutron-irradiated V-Cr and V-Si binary alloys
Additions of 5 to 14 wt% chromium to vanadium lead to very large swelling rates during neutron irradiation of the binary alloys, with swelling increasing strongly at higher irradiation temperatures. Addition of 2 wt% silicon to vanadium also leads to very large swelling rates but swelling decreases with increasing irradiation temperature. Addition of 1 wt% zirconium does not yield high swelling rates, however.
Garner, F.A.; Gelles, D.S. (Pacific Northwest Lab., Richland, WA (United States)); Takahashi, H.; Ohnuki, S.; Kinoshita, H. (Hokkaido Univ., Sapporo (Japan)); Loomis, B.A. (Argonne National Lab., IL (United States))
Use of OCA and APOLLO in Heliosat-4 method for the assessment of surface downwelling solar irradiance
the German Aerospace Center (DLR), for the assessment of surface downwelling solar irradiance (SSI). Each-based assessments of surface downwelling solar irradiance (SSI) are more and more used in the domain of solar energy, diffuse and direct surface irradiance for use in various domains: solar energy, biomass, agriculture
Influence of pulsed laser irradiation on precipitation of silver nanoparticles Jean-Philippe Blondeau a,, Stephane Pellerin b
and the distribution of the metallic nanoaggregates which are formed under the laser irradiation. Optical absorption:YAG laser irrad