Dynamic response of materials on sub-nanosecond time scales, and beryllium properties for inertial confinement fusion (open access)

Dynamic response of materials on sub-nanosecond time scales, and beryllium properties for inertial confinement fusion

During the past few years, substantial progress has been made in developing experimental techniques capable of investigating the response of materials to dynamic loading on nanosecond time scales and shorter, with multiple diagnostics probing different aspects of the behavior. these relatively short time scales are scientifically interesting because plastic flow and phase changes in common materials with simple crystal structures--such as iron--may be suppressed, allowing unusual states to be induced and the dynamics of plasticity and polymorphism to be explored. Loading by laser ablation can be particularly convenient. The TRIDENT laser has been used to impart shocks and isentropic compression waves from {approx}1 to 200GPa in a range of elements and alloys, with diagnostics including surface velocimetry (line-imaging VISAR), surface displacement (framed area imaging), x-ray diffraction (single crystal and polycrystal), ellipsometry, and Raman spectroscopy. A major motivation has been the study of the properties of beryllium under conditions relevant to the fuel capsule in inertial confinement fusion: magnetically-driven shock and isentropic compression shots at Z were used to investigate the equation of state and shock melting characteristics, complemented by laser ablation experiments to investigate plasticity and heterogeneous response. These results will help to constrain acceptable tolerances on manufacturing, and possible …
Date: December 9, 2004
Creator: Swift, D. C.; Tierney, T. E.; Luo, S. N.; Paisley, D. L.; Kyrala, G. A.; Hauer, A. et al.
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: GA-0279 (open access)

Texas Attorney General Opinion: GA-0279

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Whether the placement of one-party foreclosable contractual liens on land by a developer that supersede the homestead rights created in article XVI, section 50 of the Texas Constitution violates the Texas Homestead Act (RQ-0236-GA)
Date: December 9, 2004
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
The WARP Code: Modeling High Intensity Ion Beams (open access)

The WARP Code: Modeling High Intensity Ion Beams

The Warp code, developed for heavy-ion driven inertial fusion energy studies, is used to model high intensity ion (and electron) beams. Significant capability has been incorporated in Warp, allowing nearly all sections of an accelerator to be modeled, beginning with the source. Warp has as its core an explicit, three-dimensional, particle-in-cell model. Alongside this is a rich set of tools for describing the applied fields of the accelerator lattice, and embedded conducting surfaces (which are captured at sub-grid resolution). Also incorporated are models with reduced dimensionality: an axisymmetric model and a transverse ''slice'' model. The code takes advantage of modern programming techniques, including object orientation, parallelism, and scripting (via Python). It is at the forefront in the use of the computational technique of adaptive mesh refinement, which has been particularly successful in the area of diode and injector modeling, both steady-state and time-dependent. In the presentation, some of the major aspects of Warp will be overviewed, especially those that could be useful in modeling ECR sources. Warp has been benchmarked against both theory and experiment. Recent results will be presented showing good agreement of Warp with experimental results from the STS500 injector test stand. Additional information can be found on …
Date: December 9, 2004
Creator: Grote, D. P.; Friedman, A.; Vay, J. L. & Haber, I.
Object Type: Article
System: The UNT Digital Library
Social Security Reform (open access)

Social Security Reform

This report examines the debate over the future of the Social Security system. It includes discussion of recent developments; background and analysis with information about the basic debate, specific area of contention, reform initiatives; and relevant legislation.
Date: December 9, 2004
Creator: Nuschler, Dawn
Object Type: Report
System: The UNT Digital Library
Microbial Formaldehyde Oxidation (open access)

Microbial Formaldehyde Oxidation

This project analyzed how cells sense and generate energy from formaldehyde oxidation. Formaldehyde is a toxin that is produced naturally, chemically or by metabolism of a wide variety of methyl-containing compounds. Our goals are to identify how cells sense the presence of this toxic compound and determine how they generate energy and nutrients from the oxidation of formaldehyde. This research capitalizes on the role of the Rhodobacter sphaeroides glutathione dependent formaldehyde dehydrogenase (GSH FDH) in a formaldehyde oxidation pathway that is apparently found in a wide variety of microbes, plants and animals. Thus, our findings illustrate what is required for a large variety of cells to metabolize this toxic compound. A second major focus of our research is to determine how cells sense the presence of this toxic compound and control the expression of gene products required for its detoxification.
Date: December 9, 2004
Creator: Donohue, Timothy J.
Object Type: Report
System: The UNT Digital Library
Nuclear reactions with 11C and 14O radioactive ion beams (open access)

Nuclear reactions with 11C and 14O radioactive ion beams

Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions …
Date: December 9, 2004
Creator: Guo, Fanqing
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Material Property Estimation for Direct Detection of DNAPL using Integrated Ground-Penetrating Radar Velocity, Imaging and Attribute Analysis (open access)

Material Property Estimation for Direct Detection of DNAPL using Integrated Ground-Penetrating Radar Velocity, Imaging and Attribute Analysis

The focus of this project is direct detection of DNAPL's specifically chlorinated solvents, via material property estimation from multi-fold surface ground-penetrating radar (GPR) data. We combine state-of-the-art GPR processing methodology with quantitative attribute analysis and material property estimation to determine the location and extent of residual and/or pooled DNAPL in both the vadose and saturated zones. An important byproduct of our research is state-of-the-art imaging which allows us to pinpoint attribute anomalies, characterize stratigraphy, identify fracture zones, and locate buried objects.
Date: December 9, 2004
Creator: Bradford, John H.; Holbrook, Stephen & Smithson, Scott B.
Object Type: Report
System: The UNT Digital Library
Functional Analysis and Discovery of Microbial Genes Transforming Metallic and Organic Pollutants: Database and Experimental Tools (open access)

Functional Analysis and Discovery of Microbial Genes Transforming Metallic and Organic Pollutants: Database and Experimental Tools

Microbial functional genomics is faced with a burgeoning list of genes which are denoted as unknown or hypothetical for lack of any knowledge about their function. The majority of microbial genes encode enzymes. Enzymes are the catalysts of metabolism; catabolism, anabolism, stress responses, and many other cell functions. A major problem facing microbial functional genomics is proposed here to derive from the breadth of microbial metabolism, much of which remains undiscovered. The breadth of microbial metabolism has been surveyed by the PIs and represented according to reaction types on the University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD): http://umbbd.ahc.umn.edu/search/FuncGrps.html The database depicts metabolism of 49 chemical functional groups, representing most of current knowledge. Twice that number of chemical groups are proposed here to be metabolized by microbes. Thus, at least 50% of the unique biochemical reactions catalyzed by microbes remain undiscovered. This further suggests that many unknown and hypothetical genes encode functions yet undiscovered. This gap will be partly filled by the current proposal. The UM-BBD will be greatly expanded as a resource for microbial functional genomics. Computational methods will be developed to predict microbial metabolism which is not yet discovered. Moreover, a concentrated effort to discover new microbial metabolism will be …
Date: December 9, 2004
Creator: Wackett, Lawrence P. & Ellis, Lynda B.M.
Object Type: Report
System: The UNT Digital Library
Automating Shallow Seismic Imaging (open access)

Automating Shallow Seismic Imaging

This seven-year, shallow-seismic reflection research project had the aim of improving geophysical imaging of possible contaminant flow paths. Thousands of chemically contaminated sites exist in the United States, including at least 3,700 at Department of Energy (DOE) facilities. Imaging technologies such as shallow seismic reflection (SSR) and ground-penetrating radar (GPR) sometimes are capable of identifying geologic conditions that might indicate preferential contaminant-flow paths. Historically, SSR has been used very little at depths shallower than 30 m, and even more rarely at depths of 10 m or less. Conversely, GPR is rarely useful at depths greater than 10 m, especially in areas where clay or other electrically conductive materials are present near the surface. Efforts to image the cone of depression around a pumping well using seismic methods were only partially successful (for complete references of all research results, see the full Final Technical Report, DOE/ER/14826-F), but peripheral results included development of SSR methods for depths shallower than one meter, a depth range that had not been achieved before. Imaging at such shallow depths, however, requires geophone intervals of the order of 10 cm or less, which makes such surveys very expensive in terms of human time and effort. We also …
Date: December 9, 2004
Creator: Steeples, Don W.
Object Type: Report
System: The UNT Digital Library
Front Surface Spectral Control Development for TPV Energy Conversion (a Presentation) (open access)

Front Surface Spectral Control Development for TPV Energy Conversion (a Presentation)

This paper discusses the introduction to the potential of alternative materials that provide higher temperature stability than current materials. The outline of this report is: (1) Review briefly the importance of spectral control; (2) Provide current results; (3) Introduce the temperature stability issue; (4) Describe the requirements for alternate materials and (5) Present alternative materials. The conclusions of this report are: (1) Antimony selenide has achieved the highest spectral efficiency to date; (2) Several materials expected to have higher temperature stability have been shown to be viable; (3) So far, with limited development, the performance of the these materials is lower than Antimony selenide; and (4) Additional development will be required to achieve similar or higher performance.
Date: December 9, 2004
Creator: Rahmlow, T. D., Jr.; Lazo-Wasem, J. E.; Gratrix, E. J.; Fourspring, P. M. & DePoy, D. M.
Object Type: Article
System: The UNT Digital Library
81929 - Fission-Product Separation Based on Room - Temperature Ionic Liquids (open access)

81929 - Fission-Product Separation Based on Room - Temperature Ionic Liquids

This project has demonstrated that Sr2+ and Cs+ can be selectively extracted from aqueous solutions into ionic liquids using crown ethers and that unprecedented large distribution coefficients can be achieved for these fission products. The volume of secondary wastes can be significantly minimized with this new separation technology. Through the current EMSP funding, the solvent extraction technology based on ionic liquids has been shown to be viable and can potentially provide the most efficient separation of problematic fission products from high level wastes. The key results from the current funding period are the development of highly selective extraction process for cesium ions based on crown ethers and calixarenes, optimization of selectivities of extractants via systematic change of ionic liquids, and investigation of task-specific ionic liquids incorporating both complexant and solvent characteristics.
Date: December 9, 2004
Creator: Rogers, Robin D.
Object Type: Report
System: The UNT Digital Library
K(892)* resonance production in Au+Au and p+p collisions at {radical}s{sub NN} = 200 GeV at RHIC (open access)

K(892)* resonance production in Au+Au and p+p collisions at {radical}s{sub NN} = 200 GeV at RHIC

The short-lived K(892)* resonance provides an efficient tool to probe properties of the hot and dense medium produced in relativistic heavy-ion collisions. We report measurements of K* in {radical}s{sub NN} = 200 GeV Au+Au and p+p collisions reconstructed via its hadronic decay channels K(892)*{sup 0} {yields} K{pi} and K(892)*{sup +-} {yields} K{sub S}{sup 0}{pi}{sup +-} using the STAR detector at RHIC. The K*{sup 0} mass has been studied as function of p{sub T} in minimum bias p + p and central Au+Au collisions. The K* p{sub T} spectra for minimum bias p + p interactions and for Au+Au collisions in different centralities are presented. The K*/K ratios for all centralities in Au+Au collisions are found to be significantly lower than the ratio in minimum bias p + p collisions, indicating the importance of hadronic interactions between chemical and kinetic freeze-outs. The nuclear modification factor of K* at intermediate p{sub T} is similar to that of K{sub S}{sup 0}, but different from {Lambda}. This establishes a baryon-meson effect over a mass effect in the particle production at intermediate p{sub T} (2 < p{sub T} {le} 4 GeV/c). A significant non-zero K*{sup 0} elliptic flow (v{sub 2}) is observed in Au+Au collisions …
Date: December 9, 2004
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Object Type: Article
System: The UNT Digital Library
Northern Ireland: The Peace Process (open access)

Northern Ireland: The Peace Process

This report provides background information regarding political violence and the peace process in Northern Ireland. It includes further information about the devolved government and recurrent crises (1999-2002, 2003-2007 and 2008-2010), implementation of police reforms, recent events and ongoing challenges, relevant U.S. policy, and recent legislation.
Date: December 9, 2004
Creator: Archick, Kristin
Object Type: Report
System: The UNT Digital Library
First and Second Quarters Hanford Seismic Report for Fiscal Year 2005 (open access)

First and Second Quarters Hanford Seismic Report for Fiscal Year 2005

This report describes the earthquakes that occurred in the Hanford seismic monitoring network during the first and second quarters of Fiscal Year 2005
Date: December 9, 2004
Creator: Hartshorn, Donald C.; Reidel, Steve P.; Rohay, Alan C.; Sweeney, Mark D. & Clayton, Ray E.
Object Type: Report
System: The UNT Digital Library
Immigration: Foreign Physicians and the J-1 Visa Waiver Program (open access)

Immigration: Foreign Physicians and the J-1 Visa Waiver Program

This report focuses on those IMGs who are foreign nationals, hereafter referred to as foreign medical graduates (FMGs). Many FMGs first entered the United States to receive graduate medical education and training as cultural exchange visitors through the J-1 cultural exchange program. Other ways for FMGs to enter the United States include other temporary visa programs as well as permanent immigration avenues such as family- or employment-based immigration, the diversity lottery, and humanitarian relief provisions.
Date: December 9, 2004
Creator: Ester, Karma A.
Object Type: Report
System: The UNT Digital Library
Spectrum Management: Special Funds (open access)

Spectrum Management: Special Funds

None
Date: December 9, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Optimization of Aperiodic Waveguide Mode Converters (open access)

Optimization of Aperiodic Waveguide Mode Converters

Previous studies by Haq, Webb and others have demonstrated the design of aperiodic waveguide structures to act as filters and mode converters. These aperiodic structures have been shown to yield high efficiency mode conversion or filtering in lengths considerably shorter than structures using gradual transitions and periodic perturbations. The design method developed by Haq and others has used mode-matching models for the irregular, stepped waveguides coupled with computer optimization to achieve the design goal using a Matlab optimization routine. Similar designs are described here, using a mode matching code written in Fortran and with optimization accomplished with the downhill simplex method with simulated annealing using an algorithm from the book Numerical Recipes in Fortran. Where Haq et al. looked mainly for waveguide shapes with relatively wide cavities, we have sought lower profile designs. It is found that lower profiles can meet the design goals and result in a structure with lower Q. In any case, there appear to be very many possible configurations for a given mode conversion goal, to the point that it is unlikely to find the same design twice. Tolerance analysis was carried out for the designs to show edge sensitivity and Monte Carlo degradation rate. The …
Date: December 9, 2004
Creator: Burke, G. J.; White, D. A. & Thompson, C. A.
Object Type: Article
System: The UNT Digital Library
The New Basel Capital Accord: A Return to Bank Supervisory Judgments (open access)

The New Basel Capital Accord: A Return to Bank Supervisory Judgments

None
Date: December 9, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Air-Flow Simulation in Realistic Models of the Trachea (open access)

Air-Flow Simulation in Realistic Models of the Trachea

In this article we present preliminary results from a new technique for flow simulation in realistic anatomical airways. The airways are extracted by means of Level-Sets methods that accurately model the complex and varying surfaces of anatomical objects. The surfaces obtained are defined at the sub-pixel level where they intersect the Cartesian grid of the image domain. It is therefore straightforward to construct embedded boundary representations of these objects on the same grid, for which recent work has enabled discretization of the Navier- Stokes equations for incompressible fluids. While most classical techniques require construction of a structured mesh that approximates the surface in order to extrapolate a 3D finite-element gridding of the whole volume, our method directly simulates the air-flow inside the extracted surface without losing any complicated details and without building additional grids.
Date: December 9, 2004
Creator: Deschamps, T; Schwartz, P & Trebotich, D
Object Type: Article
System: The UNT Digital Library
Vessel Segmentation and Blood Flow Simulation Using Level-Sets and Embedded Boundary Methods (open access)

Vessel Segmentation and Blood Flow Simulation Using Level-Sets and Embedded Boundary Methods

In this article we address the problem of blood flow simulation in realistic vascular objects. The anatomical surfaces are extracted by means of Level-Sets methods that accurately model the complex and varying surfaces of pathological objects such as aneurysms and stenoses. The surfaces obtained are defined at the sub-pixel level where they intersect the Cartesian grid of the image domain. It is therefore straightforward to construct embedded boundary representations of these objects on the same grid, for which recent work has enabled discretization of the Navier-Stokes equations for incompressible fluids. While most classical techniques require construction of a structured mesh that approximates the surface in order to extrapolate a 3D finite-element gridding of the whole volume, our method directly simulates the blood-flow inside the extracted surface without losing any complicated details and without building additional grids.
Date: December 9, 2004
Creator: Deschamps, T; Schwartz, P; Trebotich, D; Colella, P; Saloner, D & Malladi, R
Object Type: Article
System: The UNT Digital Library
Spent Nuclear Fuel Storage Locations and Inventory (open access)

Spent Nuclear Fuel Storage Locations and Inventory

None
Date: December 9, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
RCRA Groundwater Monitoring Plan for Single-Shell Tank WAste Management Area A-AX at the Hanford Site, Interim Change Notice 3 (open access)

RCRA Groundwater Monitoring Plan for Single-Shell Tank WAste Management Area A-AX at the Hanford Site, Interim Change Notice 3

This ICN documents a change in the critical mean values used for statistical upgradient/downgradient comparisons in FY 2005.
Date: December 9, 2004
Creator: Narbutovskih, Susan M.
Object Type: Report
System: The UNT Digital Library
Verification and Validation of MERCURY: A Modern, Monte Carlo Particle Transport Code (open access)

Verification and Validation of MERCURY: A Modern, Monte Carlo Particle Transport Code

Verification and Validation (V&V) is a critical phase in the development cycle of any scientific code. The aim of the V&V process is to determine whether or not the code fulfills and complies with the requirements that were defined prior to the start of the development process. While code V&V can take many forms, this paper concentrates on validation of the results obtained from a modern code against those produced by a validated, legacy code. In particular, the neutron transport capabilities of the modern Monte Carlo code MERCURY are validated against those in the legacy Monte Carlo code TART. The results from each code are compared for a series of basic transport and criticality calculations which are designed to check a variety of code modules. These include the definition of the problem geometry, particle tracking, collisional kinematics, sampling of secondary particle distributions, and nuclear data. The metrics that form the basis for comparison of the codes include both integral quantities and particle spectra. The use of integral results, such as eigenvalues obtained from criticality calculations, is shown to be necessary, but not sufficient, for a comprehensive validation of the code. This process has uncovered problems in both the transport code …
Date: December 9, 2004
Creator: Procassini, R J; Cullen, D E; Greenman, G M & Hagmann, C A
Object Type: Article
System: The UNT Digital Library
Special Rules and Options for Regulating the Amending Process (open access)

Special Rules and Options for Regulating the Amending Process

This report identifies the most common kinds of modifications recommended by the Rules Committee in terms used by the committee.
Date: December 9, 2004
Creator: Saturno, James V.
Object Type: Report
System: The UNT Digital Library