66 Matching Results

Results open in a new window/tab.

Veterans' Disability Benefits: VA Can Improve Its Procedures for Obtaining Military Service Records (open access)

Veterans' Disability Benefits: VA Can Improve Its Procedures for Obtaining Military Service Records

A letter report issued by the Government Accountability Office with an abstract that begins "The Ranking Democratic Member, House Committee on Veterans' Affairs, asked GAO to determine (1) whether VA's internal assessments indicate its regional offices are complying with the requirements of the Veterans Claims Assistance Act (VCAA) of 2000 for obtaining military service records for veterans' disability compensation claims and (2) whether VBA could improve its procedures for obtaining military service records for claims involving post-traumatic stress disorder (PTSD)."
Date: December 12, 2006
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
U.S. Insular Areas: Economic, Fiscal, and Financial Accountability Challenges (open access)

U.S. Insular Areas: Economic, Fiscal, and Financial Accountability Challenges

A letter report issued by the Government Accountability Office with an abstract that begins "The U.S. insular areas of American Samoa, the Commonwealth of the Northern Mariana Islands (CNMI), Guam, and the U.S. Virgin Islands (USVI), face long-standing economic, fiscal, and financial accountability challenges. GAO was requested to identify and report on the (1) economic challenges facing each government, including the effect of changing tax and trade laws on their economies; (2) fiscal condition of each government; and (3) financial accountability of each government, including compliance with the Single Audit Act, which applies to nonfederal entities that receive $500,000 or more a year in federal funding."
Date: December 12, 2006
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Disorder and size effects on Kondo interactions and magnetic correlations in CePt2 nanoscrystals (open access)

Disorder and size effects on Kondo interactions and magnetic correlations in CePt2 nanoscrystals

The evolution of the Kondo effect and magnetic correlations with size reduction in CePt{sub 2} nanoparticles (3.1-26 nm) is studied by analysis of the temperature-dependent specific heat and magnetic susceptibility. The antiferromagnetic correlations diminish with size reduction. The Kondo effect predominates at small particle size with trivalent, small Kondo temperature (T{sub K}) magnetic regions coexisting with strongly mixed valent, large T{sub K} nonmagnetic regions. We discuss the role of structural disorder, background density of states and the electronic quantum size effect on the results.
Date: December 12, 2006
Creator: Chen, Y. Y.; Huang, P. H.; Ou, M. N.; Wang, C. R.; Yao, Y. D.; Lee, T. K. et al.
Object Type: Article
System: The UNT Digital Library
Final Hazard Categorization for the Remediation of Six 300-FF-2 Operable Unit Solid Waste Burial Grounds (open access)

Final Hazard Categorization for the Remediation of Six 300-FF-2 Operable Unit Solid Waste Burial Grounds

This report provides the final hazard categorization (FHC) for the remediation of six solid waste disposal sites (referred to as burial grounds) located in the 300-FF-2 Operable Unit (OU) on the Hanford Site. These six sites (618-1, 618-2, 618-3, 618-7, 618-8, and 618-13 Burial Grounds) were determined to have a total radionuclide inventory (WCH 2005a, WCH 2005d, WCH 2005e and WCH 2006b) that exceeds the DOE-STD-1027 Category 3 threshold quantity (DOE 1997) and are the subject of this analysis. This FHC document examines the hazards, identifies appropriate controls to manage the hazards, and documents the FHC and commitments for the 300-FF-2 Burial Grounds Remediation Project.
Date: December 12, 2006
Creator: Ludowise, J. D.
Object Type: Report
System: The UNT Digital Library
Greensheet (Houston, Tex.), Vol. 37, No. 530, Ed. 1 Tuesday, December 12, 2006 (open access)

Greensheet (Houston, Tex.), Vol. 37, No. 530, Ed. 1 Tuesday, December 12, 2006

Free weekly newspaper that includes business and classified advertising.
Date: December 12, 2006
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Exemptions from Environmental Law fora the Department of Defense: Background and Issues for Congress (open access)

Exemptions from Environmental Law fora the Department of Defense: Background and Issues for Congress

This report provides Background and Issues for Congress on Exemptions from Environmental Law for the Department of Defense. several environmental statutes contain national security exemptions which is a department of defense can obtain on a case by case basis.
Date: December 12, 2006
Creator: Bearden, David M.
Object Type: Report
System: The UNT Digital Library
The WTO, Intellectual Property Rights, and the Access to Medicines Controversy (open access)

The WTO, Intellectual Property Rights, and the Access to Medicines Controversy

None
Date: December 12, 2006
Creator: Fergusson, Ian F.
Object Type: Report
System: The UNT Digital Library
The Congressional Appropriations Process: An Introduction (open access)

The Congressional Appropriations Process: An Introduction

This report contains a brief overview and introduction on the congressional appropriations process.
Date: December 12, 2006
Creator: Streeter, Sandy
Object Type: Report
System: The UNT Digital Library
Immigration Consequences of Criminal Activity (open access)

Immigration Consequences of Criminal Activity

None
Date: December 12, 2006
Creator: Garcia, Michael J.
Object Type: Report
System: The UNT Digital Library
The Effects on U.S. Farm Workers of an Agricultural Guest Worker Program (open access)

The Effects on U.S. Farm Workers of an Agricultural Guest Worker Program

This report discusses the debate concerning an agricultural guest worker program and the impact such a program might have on U.S. workers. Guest worker programs are meant to assure employers (e.g., fruit, vegetable, and horticultural specialty growers) of an adequate supply of labor when and where it is needed, while not adding permanent residents to the U.S. population. They include mechanisms -- such as the H-2A program's labor certification process -- intended to avoid adversely affecting the wages and working conditions of similarly-employed U.S. workers.
Date: December 12, 2006
Creator: Levine, Linda
Object Type: Report
System: The UNT Digital Library
Measurement of the B0 to \pi l^+ \nu Form-Factor Shape and Branching Fraction, and Determination of |V_{ub}| with a Loose Neutrino Reconstruction Technique (open access)

Measurement of the B0 to \pi l^+ \nu Form-Factor Shape and Branching Fraction, and Determination of |V_{ub}| with a Loose Neutrino Reconstruction Technique

We report the results of a study of the exclusive charmless semileptonic decay, B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}, undertaken with approximately 227 million B{bar B} pairs collected at the {Gamma}(4S) resonance with the BABAR detector. The analysis uses events in which the signal B decays are reconstructed with an innovative loose neutrino reconstruction technique. We obtain partial branching fractions in 12 bins of q{sup 2}, the momentum transfer squared, from which we extract the f{sub +}(q{sup 2}) form-factor shape and the total branching fraction {beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.46 {+-} 0.07{sub stat} {+-} 0.08{sub syst}) x 10{sup -4}. Based on a recent unquenched lattice QCD calculation of the form factor in the range q{sup 2} > 16 GeV2, we find the magnitude of the CKM matrix element |V{sub ub}| to be (4.1 {+-} 0.2{sub stat} {+-} 0.2{sub syst} +0.6 -0.4 FF)x10{sup -3}, where the last uncertainty is due to the normalization of the form factor.
Date: December 12, 2006
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
New Synthetic Methods for Hypericum Natural Products (open access)

New Synthetic Methods for Hypericum Natural Products

Organic chemistry has served as a solid foundation for interdisciplinary research areas, such as molecular biology and medicinal chemistry. An understanding of the biological activities and structural elucidations of natural products can lead to the development of clinically valuable therapeutic options. The advancements of modern synthetic methodologies allow for more elaborate and concise natural product syntheses. The theme of this study centers on the synthesis of natural products with particularly challenging structures and interesting biological activities. The synthetic expertise developed here will be applicable to analog syntheses and to other research problems.
Date: December 12, 2006
Creator: Jeon, Insik
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Phase Transformation in Cast Superaustenitic Stainless Steels (open access)

Phase Transformation in Cast Superaustenitic Stainless Steels

Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.
Date: December 12, 2006
Creator: Phillips, Nathaniel Steven Lee
Object Type: Thesis or Dissertation
System: The UNT Digital Library
International Conference on Multiscale Methods and Partial Differential Equations. (open access)

International Conference on Multiscale Methods and Partial Differential Equations.

The International Conference on Multiscale Methods and Partial Differential Equations (ICMMPDE for short) was held at IPAM, UCLA on August 26-27, 2005. The conference brought together researchers, students and practitioners with interest in the theoretical, computational and practical aspects of multiscale problems and related partial differential equations. The conference provided a forum to exchange and stimulate new ideas from different disciplines, and to formulate new challenging multiscale problems that will have impact in applications.
Date: December 12, 2006
Creator: Hou, Thomas
Object Type: Report
System: The UNT Digital Library
Multiphase Flow in Complex Fracture Apertures under a Wide Range of Flow Conditions (open access)

Multiphase Flow in Complex Fracture Apertures under a Wide Range of Flow Conditions

A better understanding of multiphase flow through fractures requires knowledge of the detailed physics of interfacial flows at the microscopic pore scale. The objective of our project was to develop tools for the simulation of such phenomena. Complementary work was performed by a group led by Dr.~Paul Meakin of the Idaho National Engineering and Environmental Laboratory. Our focus was on the lattice-Boltzmann (LB) method. In particular, we studied both the statics and dynamics of contact lines where two fluids (wetting and non-wetting) meet solid boundaries. Previous work had noted deficiencies in the way LB methods simulate such interfaces. Our work resulted in significant algorithmic improvements that alleviated these deficiencies. As a result, we were able to study in detail the behavior of the dynamic contact angle in flow through capillary tubes. Our simulations revealed that our LB method reproduces the correct scaling of the dynamic contact angle with respect to velocity, viscosity, and surface tension, without specification of an artificial slip length. Further study allowed us to identify the microscopic origin of the dynamic contact angle in LB methods. These results serve to delineate the range of applicability of multiphase LB methods to flows through complex geometries.
Date: December 12, 2006
Creator: Rothman, Daniel H.
Object Type: Report
System: The UNT Digital Library
Non-diffusive spin dynamics in a two-dimensional electrongas (open access)

Non-diffusive spin dynamics in a two-dimensional electrongas

We describe measurements of spin dynamics in thetwo-dimensional electron gas in GaAs/GaAlAs quantum wells. Opticaltechniques, including transient spin-grating spectroscopy, are used toprobe the relaxation rates of spin polarization waves in the wavevectorrange from zero to 6E4 cm-1. We find that the spin polarization lifetimeis maximal at nonzero wavevector, in contrast with expectation based onordinary spin diffusion, but in quantitative agreement with recenttheories that treat diffusion in the presence of spin-orbitcoupling.
Date: December 12, 2006
Creator: Weber, Christopher P.; Orenstein, Joseph; Bernevig, B. Andrei; Zhang, Shou-Cheng; Stephens, Jason & Awschalom, David D.
Object Type: Article
System: The UNT Digital Library
Development of a Focusing DIRC (open access)

Development of a Focusing DIRC

Benefiting from the recent introduction of new fast vacuum-based photon detectors with a transit time spread of {sigma}{sub TTS} {approx} 30-150 ps, we are developing a novel RICH detector capable of correcting the chromatic error through good time measurements; we believe that this is the first time such a technique has been demonstrated. We have built and successfully tested a particle identification detector called ''Focusing DIRC''. The concept of the prototype is based on the BaBar DIRC, with several important improvements: (a) much faster pixelated photon detectors based on Burle MCP-PMTs and Hamamatsu MaPMTs, (b) a focusing mirror which allows the photon detector to be smaller and less sensitive to background in future applications, (c) electronics allowing the measurement of single photon timing to better than {sigma} {approx} 100-200ps, which allows a correction of the chromatic error. The detector was tested in a SLAC 10GeV/c electron test beam. This detector concept could be used for particle identification at Super B-factory, ILC, GlueX, Panda, etc.
Date: December 12, 2006
Creator: Benitez, J.; Bedajanek, I.; Leith, D.W.G.S.; Mazaheri, G.; Ratcliff, B.; Suzuki, K. et al.
Object Type: Article
System: The UNT Digital Library
Oxidation of Zircaloy Fuel Cladding in Water-Cooled Nuclear Reactors (open access)

Oxidation of Zircaloy Fuel Cladding in Water-Cooled Nuclear Reactors

Our work involved the continued development of the theory of passivity and passivity breakdown, in the form of the Point Defect Model, with emphasis on zirconium and zirconium alloys in reactor coolant environments, the measurement of critically-important parameters, and the development of a code that can be used by reactor operators to actively manage the accumulation of corrosion damage to the fuel cladding and other components in the heat transport circuits in both BWRs and PWRs. In addition, the modified boiling crevice model has been further developed to describe the accumulation of solutes in porous deposits (CRUD) on fuel under boiling (BWRs) and nucleate boiling (PWRs) conditions, in order to accurately describe the environment that is contact with the Zircaloy cladding. In the current report, we have derived expressions for the total steady-state current density and the partial anodic and cathodic current densities to establish a deterministic basis for describing Zircaloy oxidation. The models are “deterministic” because the relevant natural laws are satisfied explicitly, most importantly the conversation of mass and charge and the equivalence of mass and charge (Faraday’s law). Cathodic reactions (oxygen reduction and hydrogen evolution) are also included in the models, because there is evidence that they …
Date: December 12, 2006
Creator: Macdonald, Digby; Urquidi-Macdonald, Mirna; Chen, Yingzi; Ai, Jiahe; Park, Pilyeon & Kim, Han-Sang
Object Type: Report
System: The UNT Digital Library
Numerical Simulations of the Metallicity Distribution in Dwarf Spheroidal Galaxies (open access)

Numerical Simulations of the Metallicity Distribution in Dwarf Spheroidal Galaxies

Recent observations show that the number of stars with very low metallicities in the dwarf spheroidal satellites of the Milky Way is low, despite the low average metallicities of stars in these systems. We undertake numerical simulations of star formation and metal enrichment of dwarf galaxies in order to verify whether this result can be reproduced with ''standard'' assumptions. The answer is likely to be negative, unless some selection bias against very low metallicity stars is present in the observations.
Date: December 12, 2006
Creator: Ripamonti, Emanuele; Tolstoy, E.; Helmi, A.; Battaglia, G.; /Kapteyn Astron. Inst., Groningen; Abel, T. et al.
Object Type: Article
System: The UNT Digital Library
Issues in IIA Uplifting (open access)

Issues in IIA Uplifting

Moduli stabilization in the type IIA massive string theory so far was achieved only in the AdS vacua. The uplifting to dS vacua has not been performed as yet: neither the analogs of type IIB anti-D3 brane at the tip of the conifold, nor the appropriate D-terms have been identified. The hope was recently expressed that the F-term uplifting may work. We investigate this possibility in the context of a simplified version of the type IIA model developed in hep-th/0505160 and find that the F-term does not uplift the AdS vacua to dS vacua with positive CC. Thus it remains a challenging task to find phenomenologically acceptable vacua in the type IIA string theory.
Date: December 12, 2006
Creator: Kallosh, Renata & Soroush, Masoud
Object Type: Report
System: The UNT Digital Library
Novel Aryne Chemistry in Organic Synthesis (open access)

Novel Aryne Chemistry in Organic Synthesis

Arynes are among the most intensively studied systems in chemistry. However, many aspects of the chemistry of these reactive intermediates are not well understood yet and their use as reagents in synthetic organic chemistry has been somewhat limited, due to the harsh conditions needed to generate arynes and the often uncontrolled reactivity exhibited by these species. Recently, o-silylaryl triflates, which can generate the corresponding arynes under very mild reaction conditions, have been found very useful in organic synthesis. This thesis describes several novel and useful methodologies by employing arynes, which generate from o-silylaryl triflates, in organic synthesis. An efficient, reliable method for the N-arylation of amines, sulfonamides and carbamates, and the O-arylation of phenols and carboxylic acids is described in Chapter 1. Amines, sulfonamides, phenols, and carboxylic acids are good nucleophiles, which can react with arynes generated from a-silylaryl triflates to afford the corresponding N- and O-arylated products in very high yields. The regioselectivity of unsymmetrical arynes has also been studied. A lot of useful, functional groups can tolerate our reaction conditions. Carbazoles and dibenzofurans are important heteroaromatic compounds, which have a variety of biological activities. A variety of substituted carbazoles and dibenzofwans are readily prepared in good to excellent …
Date: December 12, 2006
Creator: Liu, Zhijian
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Purple L1 Milestone Review Panel TotalView Debugger Functionality and Performance for ASC Purple (open access)

Purple L1 Milestone Review Panel TotalView Debugger Functionality and Performance for ASC Purple

ASC code teams require a robust software debugging tool to help developers quickly find bugs in their codes and get their codes running. Development debugging commonly runs up to 512 processes. Production jobs run up to full ASC Purple scale, and at times require introspection while running. Developers want a debugger that runs on all their development and production platforms and that works with all compilers and runtimes used with ASC codes. The TotalView Multiprocess Debugger made by Etnus was specified for ASC Purple to address this needed capability. The ASC Purple environment builds on the environment seen by TotalView on ASCI White. The debugger must now operate with the Power5 CPU, Federation switch, AIX 5.3 operating system including large pages, IBM compilers 7 and 9, POE 4.2 parallel environment, and rs6000 SLURM resource manager. Users require robust, basic debugger functionality with acceptable performance at development debugging scale. A TotalView installation must be provided at the beginning of the early user access period that meets these requirements. A functional enhancement, fast conditional data watchpoints, and a scalability enhancement, capability up to 8192 processes, are to be demonstrated.
Date: December 12, 2006
Creator: Wolfe, M
Object Type: Report
System: The UNT Digital Library
Report on New Capabilities for the Purple Development Environment (open access)

Report on New Capabilities for the Purple Development Environment

As part of the deliverables for the Development Environment for Purple, additional capabilities to improve the tools offerings and to address unique Purple system requirements, such as increased processor count, were expected. This report details some of the new capabilities that have been incorporated into the development environment tools for Purple. The shift on Purple to 64-bit applications (from 32-bit on White) initially broke many debugging and memory tools. Most tools were updated to support 64 bit well before Purple was delivered to LLNL, but the company that provided the popular heavy-weight 32-bit AIX memory tool, ZeroFault, was reluctant to port to 64 bit due to perceived lack of market. LLNL tried offering financial incentives to the ZeroFault developers, which were turned down, but eventually they did give vague promises to try to port to AIX 64-bit mode when they got time. The ZeroFault developers have been making intermittent and very slow progress over the last two plus years, but despite getting close, have not released a version of ZeroFault that yet meets our needs for 64-bit applications. However, given the critical need for memory tools and the uncertainty of ZeroFault development, other memory tool options were actively pursued and …
Date: December 12, 2006
Creator: Futral, W S; Chambreau, C M; Gyllenhaal, J C & Wolfe, M E
Object Type: Report
System: The UNT Digital Library
Structure, ionic Conductivity and mobile Carrier Density in Fast Ionic Conducting Chalcogenide Glasses (open access)

Structure, ionic Conductivity and mobile Carrier Density in Fast Ionic Conducting Chalcogenide Glasses

This thesis consists of six sections. The first section gives the basic research background on the ionic conduction mechanism in glass, polarization in the glass, and the method of determining the mobile carrier density in glass. The proposed work is also included in this section. The second section is a paper that characterizes the structure of MI + M{sub 2}S + (0.1 Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2}) (M = Li, Na, K and Cs) glasses using Raman and IR spectroscopy. Since the ionic radius plays an important role in determining the ionic conductivity in glasses, the glass forming range for the addition of different alkalis into the basic glass forming system 0.1 Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2} was studied. The study found that the change of the alkali radius for the same nominal composition causes significant structure change to the glasses. The third section is a paper that investigates the ionic conductivity of MI + M{sub 2}S + (0.1Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2}) (M = Li, Na, K and Cs) glasses system. Corresponding to the compositional changes in these fast ionic conducting glasses, the ionic conductivity shows changes due to the induced structural changes. …
Date: December 12, 2006
Creator: Yao, Wenlong
Object Type: Thesis or Dissertation
System: The UNT Digital Library