Iran: Regional Perspectives and U.S. Policy (open access)

Iran: Regional Perspectives and U.S. Policy

This report provides a description of Iran's neighbors' policies and interests, options for Congressional consideration, and an analysis of potential regional implications.
Date: January 13, 2010
Creator: Addis, Casey L.; Blanchard, Christopher M.; Katzman, Kenneth; Migdalovitz, Carol; Nichol, Jim; Sharp, Jeremy M. et al.
Object Type: Report
System: The UNT Digital Library
LITERATURE REVIEW ON MAXIMUM LOADING OF RADIONUCLIDES ON CRYSTALLINE SILICOTITANATE (open access)

LITERATURE REVIEW ON MAXIMUM LOADING OF RADIONUCLIDES ON CRYSTALLINE SILICOTITANATE

Plans are underway to use small column ion exchange (SCIX) units installed in high-level waste tanks to remove Cs-137 from highly alkaline salt solutions at Savannah River Site. The ion exchange material slated for the SCIX project is engineered or granular crystalline silicotitanate (CST). Information on the maximum loading of radionuclides on CST is needed by Savannah River Remediation for safety evaluations. A literature review has been conducted that culminated in the estimation of the maximum loading of all but one of the radionuclides of interest (Cs-137, Sr-90, Ba-137m, Pu-238, Pu-239, Pu-240, Pu-241, Am-241, and Cm-244). No data was found for Cm-244.
Date: October 13, 2010
Creator: Adu-Wusu, K. & Pennebaker, F.
Object Type: Report
System: The UNT Digital Library
Laser-Wakefield driven compact Compton scattering gamma-ray source (open access)

Laser-Wakefield driven compact Compton scattering gamma-ray source

None
Date: April 13, 2010
Creator: Albert, F.; Froula, D. H.; Hartemann, F. V. & Joshi, C.
Object Type: Report
System: The UNT Digital Library
QMDS: A File System Metadata Management Service Supporting a Graph Data Model-Based Query Language (open access)

QMDS: A File System Metadata Management Service Supporting a Graph Data Model-Based Query Language

Proposes QMDS: a file system metadata management service that integrates all file system metadata and uses a graph model with attributes on nodes and edges.
Date: September 13, 2010
Creator: Ames, S; Gokhale, M B & Maltzahn, C
Object Type: Article
System: The UNT Digital Library
Discharge Physics of High Power Impulse Magnetron Sputtering (open access)

Discharge Physics of High Power Impulse Magnetron Sputtering

High power impulse magnetron sputtering (HIPIMS) is pulsed sputtering where the peak power exceeds the time-averaged power by typically two orders of magnitude. The peak power density, averaged over the target area, can reach or exceed 107 W/m2, leading to plasma conditions that make ionization of the sputtered atoms very likely. A brief review of HIPIMS operation is given in a tutorial manner, illustrated by some original data related to the self-sputtering of niobium in argon and krypton. Emphasis is put on the current-voltage-time relationships near the threshold of self-sputtering runaway. The great variety of current pulse shapes delivers clues on the very strong gas rarefaction, self-sputtering runaway conditions, and the stopping of runaway due to the evolution of atom ionization and ion return probabilities as the gas plasma is replaced by metal plasma. The discussions are completed by considering instabilities and the special case of ?gasless? self-sputtering.
Date: October 13, 2010
Creator: Anders, Andre
Object Type: Article
System: The UNT Digital Library
Spin Crossover in Ferropericlase at High Pressure: A Seismically Hidden Transition? (open access)

Spin Crossover in Ferropericlase at High Pressure: A Seismically Hidden Transition?

None
Date: September 13, 2010
Creator: Antonangeli, Daniele; Siebert, Julien; Aracne, Chantel M.; Farber, Daniel L.; Bosak, A.; Hoesch, M. et al.
Object Type: Article
System: The UNT Digital Library
Mechanical design and analysis of an eight-pole superconducting vector magnet for soft x-ray magnetic dichroism measurements (open access)

Mechanical design and analysis of an eight-pole superconducting vector magnet for soft x-ray magnetic dichroism measurements

An eight-pole superconducting magnet is being developed for soft x-ray magnetic dichroism (XMD) experiments at the Advanced Light Source, Lawrence Berkley National Laboratory (LBNL). Eight conical Nb{sub 3}Sn coils with Holmium poles are arranged in octahedral symmetry to form four dipole pairs that provide magnetic fields of up to 5 T in any direction relative to the incoming x-ray beam. The dimensions of the magnet yoke as well as pole taper, diameter, and length were optimized for maximum peak field in the magnet center using the software package TOSCA. The structural analysis of the magnet is performed using ANSYS with the coil properties derived using a numerical homogenization scheme. It is found that the use of orthotropic material properties for the coil has an important influence in the design of the magnet.
Date: January 13, 2010
Creator: Arbelaez, D.; Black, A.; Prestemon, S.O.; Wang, S.; Chen, J. & Arenholz, E.
Object Type: Article
System: The UNT Digital Library
U.S.-EU Cooperation Against Terrorism (open access)

U.S.-EU Cooperation Against Terrorism

This report examines the evolution of counterterrorism cooperation between the United States and the European Union (EU), particularly since the September 11, 2001 terrorist attacks. It includes a discussion of U.S.-EU cooperation progress and ongoing challenges, as well as perspectives and issues for Congress.
Date: May 13, 2010
Creator: Archick, Kristin
Object Type: Report
System: The UNT Digital Library
Direct Comparison of Brookhaven Reflectivity Measurements with Free-Electron Theory (open access)

Direct Comparison of Brookhaven Reflectivity Measurements with Free-Electron Theory

The reflectivity at normal incidence of copper and aluminum samples was recently measured over a large frequency range at Brookhaven by one of us (JT). Then using the Kramers-Kroning integrals, and assuming the free-electron model of conductivity, the dependence of conductivity on frequency was obtained. The results seemed to suggest, for example, that the dc conductivities of the copper and evaporated aluminum samples are a factor of 3 lower than expected. We propose in this report, instead, directly fitting the free-electron model to the low frequency end of the reflectivity data. This fitting does not depend on the higher frequency results and on Kramers-Kronig integrations, but it does assume that the data at the low frequency end is sufficiently accurate. Note that for our LCLS wakefield studies, it is only over these (relatively) low frequencies that we need to know the electrical properties of the metals. The equations that relate reflectivity R with the free electron parameters dc conductivity {sigma} and relaxation time {tau} are: (1) {tilde {sigma}} = {sigma}/1-ikc{tau}; (2) {tilde n} = {radical} {tilde {epsilon}} = {radical}(1+4{pi}i{tilde k}c/{omega}); and (3) R = |{tilde n}-1/{tilde n} + 1|{sup 2}. The parameters are ac conductivity {tilde {sigma}}, index of refraction …
Date: December 13, 2010
Creator: Bane, Karl L.F.
Object Type: Report
System: The UNT Digital Library
Tank 40 Final SB6 Chemical Characterization Results (open access)

Tank 40 Final SB6 Chemical Characterization Results

A sample of Sludge Batch 6 (SB6) was taken from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS), and a portion of the sample was designated for SB6 processing studies. The SB6 WAPS sample was also analyzed for chemical composition including noble metals and fissile composition, and these results are reported here. These analyses along with the WAPS radionuclide analyses will help define the composition of the sludge in Tank 40 that is currently being fed to DWPF as SB6. At the Savannah River National Laboratory (SRNL) the 3-L Tank 40 SB6 sample was transferred from the shipping container into a 4-L high density polyethylene vessel and solids were allowed to settle overnight. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 485 g sub-sample was removed. This sub-sample was then utilized for all subsequent analytical samples.
Date: August 13, 2010
Creator: Bannochie, C.
Object Type: Report
System: The UNT Digital Library
Tracking the Sun III; The Installed Cost of Photovoltaics in the United States from 1998-2009 (open access)

Tracking the Sun III; The Installed Cost of Photovoltaics in the United States from 1998-2009

Installations of solar photovoltaic (PV) systems have been growing at a rapid pace in recent years. In 2009, approximately 7,500 megawatts (MW) of PV were installed globally, up from approximately 6,000 MW in 2008, consisting primarily of grid-connected applications. With 335 MW of grid-connected PV capacity added in 2009, the United States was the world's fourth largest PV market in 2009, behind Germany, Italy, and Japan. The market for PV in the United States is driven by national, state, and local government incentives, including up-front cash rebates, production-based incentives, requirements that electricity suppliers purchase a certain amount of solar energy, and federal and state tax benefits. These programs are, in part, motivated by the popular appeal of solar energy, and by the positive attributes of PV - modest environmental impacts, avoidance of fuel price risks, coincidence with peak electrical demand, and the possible deployment of PV at the point of use. Given the relatively high cost of PV, however, a key goal of these policies is to encourage cost reductions over time. Therefore, as policy incentives have become more significant and as PV deployment has accelerated, so too has the desire to track the installed cost of PV systems over …
Date: December 13, 2010
Creator: Barbose, Galen; Darghouth, Naim & Wiser, Ryan
Object Type: Report
System: The UNT Digital Library

Field Test of a DHW Distribution System: Temperature and Flow Analyses

This presentation discusses a field test of a DHW distribution system in an occupied townhome. It includes measured fixture flows and temperatures, a tested recirculation system, evaluated disaggregation of flow by measured temperatures, Aquacraft Trace Wizard analysis, and comparison.
Date: May 13, 2010
Creator: Barley, C. D.; Hendron, B. & Magnusson, L.
Object Type: Presentation
System: The UNT Digital Library
Quark mass variation constraints from Big Bang nucleosynthesis (open access)

Quark mass variation constraints from Big Bang nucleosynthesis

We study the impact on the primordial abundances of light elements created of a variation of the quark masses at the time of Big Bang nucleosynthesis (BBN). In order to navigate through the particle and nuclear physics required to connect quark masses to binding energies and reaction rates in a model-independent way we use lattice QCD data and an hierarchy of effective field theories. We find that the measured {sup 4}He abundances put a bound of {delta}-1% {approx}< m{sub q}/m{sub 1} {approx}< 0.7%. The effect of quark mass variations on the deuterium abundances can be largely compensated by changes of the baryon-to-photon ratio {eta}. Including the bounds on the variation of {eta} coming from WMAP results and some additional assumptions narrows the range of allowed values of {delta}m{sub q}/m{sub q} somewhat.
Date: December 13, 2010
Creator: Bedaque, P.; Luu, T. & Platter, L.
Object Type: Article
System: The UNT Digital Library
2010 Water & Aqueous Solutions (open access)

2010 Water & Aqueous Solutions

Water covers more than two thirds of the surface of the Earth and about the same fraction of water forms the total mass of a human body. Since the early days of our civilization water has also been in the focus of technological developments, starting from converting it to wine to more modern achievements. The meeting will focus on recent advances in experimental, theoretical, and computational understanding of the behavior of the most important and fascinating liquid in a variety of situations and applications. The emphasis will be less on water properties per se than on water as a medium in which fundamental dynamic and reactive processes take place. In the following sessions, speakers will discuss the latest breakthroughs in unraveling these processes at the molecular level: Water in Solutions; Water in Motion I and II; Water in Biology I and II; Water in the Environment I and II; Water in Confined Geometries and Water in Discussion (keynote lecture and poster winners presentations).
Date: August 13, 2010
Creator: Ben-Amotz, Dor
Object Type: Article
System: The UNT Digital Library
Innovations in Nuclear Infrastructure and Education (open access)

Innovations in Nuclear Infrastructure and Education

The decision to implement the Innovation in Nuclear Infrastructure and Engineering Program (INIE) was an important first step towards ensuring that the United States preserves its worldwide leadership role in the field of nuclear science and engineering. Prior to INIE, university nuclear science and engineering programs were waning, undergraduate student enrollment was down, university research reactors were being shut down, while others faced the real possibility of closure. For too long, cutting edge research in the areas of nuclear medicine, neutron scattering, radiochemistry, and advanced materials was undervalued and therefore underfunded. The INIE program corrected this lapse in focus and direction and started the process of drawing a new blueprint with positive goals and objectives that supports existing as well the next generation of educators, students and researchers.
Date: December 13, 2010
Creator: Bernard, John
Object Type: Report
System: The UNT Digital Library
Strategies for measuring fuel rho-R and mix using gamma-rays (open access)

Strategies for measuring fuel rho-R and mix using gamma-rays

None
Date: September 13, 2010
Creator: Bernstein, L. A.; Caggiano, J. A.; Cerjan, C.; Fortner, R.; Herrmann, H.; Hoffman, N. et al.
Object Type: Report
System: The UNT Digital Library
Science and Technology Review October/November 2010 (open access)

Science and Technology Review October/November 2010

None
Date: September 13, 2010
Creator: Blobaum, K. J.
Object Type: Report
System: The UNT Digital Library
Directional Fast Neutron Detection using a Time Projection Chamber (open access)

Directional Fast Neutron Detection using a Time Projection Chamber

None
Date: April 13, 2010
Creator: Bowden, N.; Heffner, M.; Carosi, G.; Cater, D.; O'Malley, P.; Mintz, J. et al.
Object Type: Article
System: The UNT Digital Library
United Nations Peacekeeping: Issues for Congress (open access)

United Nations Peacekeeping: Issues for Congress

A major issue facing the United Nations, the United States, and the 111th Congress is the extent to which the United Nations has the capacity to restore or keep the peace in the changing world environment. Associated with this issue is the expressed need for a reliable source of funding and other resources for peacekeeping and improved efficiencies of operation. This report serves as a tracking report for action by Congress on United Nations peacekeeping. Funding and provisioning issues are examined.
Date: August 13, 2010
Creator: Browne, Marjorie Ann
Object Type: Report
System: The UNT Digital Library
Studies in Low-Energy Nuclear Science (open access)

Studies in Low-Energy Nuclear Science

This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187.
Date: January 13, 2010
Creator: Brune, Carl R. & Grimes, Steven M.
Object Type: Report
System: The UNT Digital Library
Nevada Test Site Environmental Report 2009, Attachment A: Site Description (open access)

Nevada Test Site Environmental Report 2009, Attachment A: Site Description

This attachment expands on the general description of the Nevada Test Site (NTS) presented in the Introduction to the Nevada Test Site Environmental Report 2009. Included are subsections that summarize the site’s geological, hydrological, climatological, and ecological setting. The cultural resources of the NTS are also presented. The subsections are meant to aid the reader in understanding the complex physical and biological environment of the NTS. An adequate knowledge of the site’s environment is necessary to assess the environmental impacts of new projects, design and implement environmental monitoring activities for current site operations, and assess the impacts of site operations on the public residing in the vicinity of the NTS. The NTS environment contributes to several key features of the site that afford protection to the inhabitants of adjacent areas from potential exposure to radioactivity or other contaminants resulting from NTS operations. These key features include the general remote location of the NTS, restricted access, extended wind transport times, the great depths to slow-moving groundwater, little or no surface water, and low population density. This attachment complements the annual summary of monitoring program activities and dose assessments presented in the main body of this report.
Date: September 13, 2010
Creator: Cathy Wills, ed.
Object Type: Report
System: The UNT Digital Library
Nevada Test Site Environmental Report Summary 2009 (open access)

Nevada Test Site Environmental Report Summary 2009

The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) directs the management and operation of the Nevada Test Site (NTS). NNSA/NSO prepares the Nevada Test Site Environmental Report (NTSER) to provide the public an understanding of the environmental monitoring and compliance activities that are conducted on the NTS to protect the public and the environment from radiation hazards and from nonradiological impacts. The NTSER is a comprehensive report of environmental activities performed at the NTS and offsite facilities over the previous calendar year. It is prepared annually to meet the requirements and guidelines of the U.S. Department of Energy (DOE) and the information needs of NNSA/NSO stakeholders. This summary provides an abbreviated and more readable version of the NTSER. It does not contain detailed descriptions or presentations of monitoring designs, data collection methods, data tables, the NTS environment, or all environmental program activities performed throughout the year. The reader may obtain a hard copy of the full NTSER as directed on the inside front cover of this summary report.
Date: September 13, 2010
Creator: Cathy Wills, ed.
Object Type: Report
System: The UNT Digital Library
Application of a Multiscale Model of Tantalum Deformation at Megabar Pressures (open access)

Application of a Multiscale Model of Tantalum Deformation at Megabar Pressures

A new multiscale simulation tool has been developed to model the strength of tantalum under high-pressure dynamic compression. This new model combines simulations at multiple length scales to explain macroscopic properties of materials. Previously known continuum models of material response under load have built upon a mixture of theoretical physics and experimental phenomenology. Experimental data, typically measured at static pressures, are used as a means of calibration to construct models that parameterize the material properties; e.g., yield stress, work hardening, strain-rate dependence, etc. The pressure dependence for most models enters through the shear modulus, which is used to scale the flow stress. When these models are applied to data taken far outside the calibrated regions of phase space (e.g., strain rate or pressure) they often diverge in their predicted behavior of material deformation. The new multiscale model, developed at Lawrence Livermore National Laboratory, starts with interatomic quantum mechanical potential and is based on the motion and multiplication of dislocations. The basis for the macroscale model is plastic deformation by phonon drag and thermally activated dislocation motion and strain hardening resulting from elastic interactions among dislocations. The dislocation density, {rho}, and dislocation velocity, {nu}, are connected to the plastic strain rate …
Date: May 13, 2010
Creator: Cavallo, R. M.; Park, H.; Barton, N. R.; Remignton, B. A.; Pollaine, S. M.; Prisbrey, S. T. et al.
Object Type: Article
System: The UNT Digital Library
Large-scale Relativistic Configuration-interaction Calculations for the 2s-2p and 3s-3p Transition Energies of Xenon Ions (open access)

Large-scale Relativistic Configuration-interaction Calculations for the 2s-2p and 3s-3p Transition Energies of Xenon Ions

None
Date: April 13, 2010
Creator: Chen, M H & Cheng, K T
Object Type: Article
System: The UNT Digital Library