BG/L Calculations of the QCD Critical Temperature and Equation of State (open access)

BG/L Calculations of the QCD Critical Temperature and Equation of State

We summarize the latest results from performing Lattice QCD calculations with two different discretization schemes, asqtad and p4fat3, on the LLNL BG/L supercomputer, and present a plan for continued running to complete the calculation of the QCD transition temperature and equation of state.
Date: December 2, 2007
Creator: Battacharya, T.; Bazavov, A.; Cheng, M.; Christ, N.; DeTar, C.; Gottlieb, S. et al.
Object Type: Report
System: The UNT Digital Library
Electronic Structure of Lithium Battery Materials (open access)

Electronic Structure of Lithium Battery Materials

Lithium batteries are important as the power source for portable electronic devices and could also be used in hybrid vehicles with improvements in capacity. We have used first principles calculations of electronic structure to determine how charge is redistributed as Li is added or removed. In the final of year of the project we have examined Lix(NiMn)0.5O2 and Lix(NiMnCo)0.333O2 cathode materials in more detail. As lithium is removed electrons are removed from the valence band which is mainly Oxygen 2p states at the top of the band. There is very little change in the charge state of the transition element ions in either case. These results are confirmed by electron energy loss spectroscopy which shows a pre-peak on the oxygen K edge as lithium is removed, but no changes in the transition metal L edges. We have also investigated the LixFePO4 cathode material which is less costly than the LixCoO2 used at present and is also less damaging to the environment. In this case we find that as lithium is removed there is a change in charge state of iron while electrons are removed from oxygen 2p states at the top of the valence band. Again this is confirmed by …
Date: December 2, 2007
Creator: Rez, Peter
Object Type: Report
System: The UNT Digital Library
Medical Marijuana: Review and Analysis of Federal and State Policies (open access)

Medical Marijuana: Review and Analysis of Federal and State Policies

None
Date: December 2, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
A Quasicontinuum Study of Nanovoid Collapse under Uniaxial Loading in Ta (open access)

A Quasicontinuum Study of Nanovoid Collapse under Uniaxial Loading in Ta

The mechanisms underlying the deformation of nanovoids in Ta single crystals are analyzed when they are subjected to cyclic uniaxial deformation using numerical simulations. Boundary and cell-size effects have been mitigated by means of the Quasicontinuum (QC) method. We have considered {approx} 1 billion-atom systems containing 10.9 nm voids. Two kinds of simulations have been performed, each characterized by a different boundary condition. First, we compress the material along the nominal [0 0 1] direction, resulting in a highly symmetric configuration that results in high stresses. Second, we load the material along the high-index [{bar 4}819] direction to confine plasticity to a single slip system and break the symmetry. We find that the plastic response under these two conditions is strikingly different, the former governed by dislocation loop emission and dipole formation, while the latter is dominated by twinning. We calculate the irreversible plastic work budget derived from a loading-unloading cycle and identify the most relevant yield points. These calculations represent the first fully three-dimensional, fully non-local simulations of any body-centered cubic metal using QC.
Date: December 2, 2007
Creator: Marian, J.; Knap, J. & Campbell, G.
Object Type: Article
System: The UNT Digital Library
Agricultural Research, Education, and Extension in the 2007 Farm Bill (open access)

Agricultural Research, Education, and Extension in the 2007 Farm Bill

This report covers information on a new farm bill Congress is considering. The report compares and contrasts the House version and Senate version of the farms bills, and states that updates will be made as the 2007 farm bill progresses.
Date: November 2, 2007
Creator: Rawson, Jean M.
Object Type: Report
System: The UNT Digital Library
Air Quality: Multi-Pollutant Legislation in the 110th Congress (open access)

Air Quality: Multi-Pollutant Legislation in the 110th Congress

This report discusses air pollutants (petroleum, natural gas, and coal), which account for about two-thirds of U.S. electricity generation. These gases include several pollutants that directly pose risks to human health and welfare. The report also discusses the utilities that are subject to an array of environmental regulations.
Date: November 2, 2007
Creator: Parker, Larry B. & Blodgett, John E.
Object Type: Report
System: The UNT Digital Library
America's Atomic Army: The Historical Archaeology of Camp Desert Rock (open access)

America's Atomic Army: The Historical Archaeology of Camp Desert Rock

Established in 1951, Camp Desert Rock served as the training ground for America's 'Atomic Army'. For the next six years, U.S. ground troops traveled to the Nevada desert to participate in military maneuvers during atmospheric atomic weapons testing. Nearly 60,000 soldiers received physical and psychological training in atomic warfare. Abandoned when atmospheric testing ended, Camp Desert Rock was dismantled and its buildings moved to other locations. Today, the camp appears as a sterile expanse of desert marked by rock-lined tent platforms, concrete foundations, and trash scatters. Although visually unimposing, the site is rich with the history of America's nuclear testing program.
Date: November 2, 2007
Creator: Edwards, Susan R.
Object Type: Article
System: The UNT Digital Library
Applying Agreed-Upon Procedures: Airport and Airway Trust Fund Excise Taxes (open access)

Applying Agreed-Upon Procedures: Airport and Airway Trust Fund Excise Taxes

Correspondence issued by the Government Accountability Office with an abstract that begins "We have performed the procedures contained in the enclosure to this report, which we agreed to perform and with which the Department of Transportation (DOT) concurred, solely to assist DOT's office in ascertaining whether the net excise tax revenue distributed to the Airport and Airway Trust Fund (AATF) for the fiscal year ended September 30, 2007, is supported by the underlying records. As agreed with DOT's office, we evaluated fiscal year 2007 activity affecting distributions to the AATF. In performing the agreed-upon procedures, we conducted our work in accordance with U.S. generally accepted government auditing standards, which incorporate financial audit and attestation standards established by the American Institute of Certified Public Accountants. These standards also provide guidance for performing and reporting the results of agreed-upon procedures. The adequacy of the procedures to meet your objectives is your responsibility, and we make no representation in that respect. The procedures we agreed to perform were related to (1) transactions that represent the underlying basis of amounts distributed to the AATF, (2) the Internal Revenue Service's (IRS) quarterly AATF receipt certifications, (3) the Department of the Treasury's Financial Management Service adjustments …
Date: November 2, 2007
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Applying Agreed-Upon Procedures: Highway Trust Fund Excise Taxes (open access)

Applying Agreed-Upon Procedures: Highway Trust Fund Excise Taxes

Correspondence issued by the Government Accountability Office with an abstract that begins "We have performed the procedures contained in the enclosure to this report, which we agreed to perform and with which the Department of Trasnportation (DOT) concurred, solely to assist your office in ascertaining whether the net excise tax revenue distributed to the Highway Trust Fund (HTF) for the fiscal year ended September 30, 2007, is supported by the underlying records. As agreed with your office, we evaluated fiscal year 2007 activity affecting distributions to the HTF. In performing the agreed-upon procedures, we conducted our work in accordance with U.S. generally accepted government auditing standards, which incorporate financial audit and attestation standards established by the American Institute of Certified Public Accountants. These standards also provide guidance for performing and reporting the results of agreed-upon procedures. The adequacy of the procedures to meet your objectives is your responsibility, and we make no representation in that respect. The procedures we agreed to perform were related to (1) transactions that represent the underlying basis of amounts distributed to the HTF, (2) the Internal Revenue Service's (IRS) quarterly HTF receipt certifications, (3) the Department of the Treasury's Financial Management Service adjustments to the …
Date: November 2, 2007
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Bower Cabin (open access)

Bower Cabin

The Bower Cabin, located in southern Nevada, was built and occupied by B.M. Bower and her family during the early 1920s. Bower, a prominent writer of western novels, had over 90 novels to her credit. She wrote 11 of the stories while living at the cabin and, at times, incorporated the surrounding landscape features, including the cabin site itself, into them. The site was subsequently used by a gang of rustlers and for a mining base camp. Archaeological research has identified the remnants of the main structures at the site as well as the artifact material and nearby mining activities associated with the Bower and later occupations.
Date: November 2, 2007
Creator: Drollinger, Harold
Object Type: Article
System: The UNT Digital Library
Broadband Internet Regulation and Access: Background and Issues (open access)

Broadband Internet Regulation and Access: Background and Issues

This report provides information about the Broadband Internet Regulation and Access.It also discuss its Background and Issues.
Date: November 2, 2007
Creator: Gilroy, Angele A. & Kruger, Lennard G.
Object Type: Report
System: The UNT Digital Library
The Central African Republic (open access)

The Central African Republic

This report provides a brief overview of the Central African Republic (CAR), which has been impacted by a crisis in the Darfur region of Sudan and suffers from internal rebellion.
Date: November 2, 2007
Creator: Dagne, Ted
Object Type: Report
System: The UNT Digital Library
Certain Temporary Tax Provisions (“Extenders”) Expiring in 2007 (open access)

Certain Temporary Tax Provisions (“Extenders”) Expiring in 2007

This report discusses the nature of extenders, as temporary provisions and as tax benefits. Descriptions of the extenders are included.
Date: November 2, 2007
Creator: Jackson, Pamela J. & Teefy, Jennifer
Object Type: Report
System: The UNT Digital Library
Diffusion-controlled spherulite growth in obsidian inferred from H2O concentration profiles (open access)

Diffusion-controlled spherulite growth in obsidian inferred from H2O concentration profiles

Spherulites are spherical clusters of radiating crystals that occur naturally in rhyolitic obsidian. The growth of spherulites requires diffusion and uptake of crystal forming components from the host rhyolite melt or glass, and rejection of non-crystal forming components from the crystallizing region. Water concentration profiles measured by synchrotron-source Fourier transform spectroscopy reveal that water is expelled into the surrounding matrix during spherulite growth, and that it diffuses outward ahead of the advancing crystalline front. We compare these profiles to models of water diffusion in rhyolite to estimate timescales for spherulite growth. Using a diffusion-controlled growth law, we find that spherulites can grow on the order of days to months at temperatures above the glass transition. The diffusion-controlled growth law also accounts for spherulite size distribution, spherulite growth below the glass transition, and why spherulitic glasses are not completely devitrified.
Date: November 2, 2007
Creator: Watkins, Jim; Watkins, Jim; Manga, Michael; Huber, Christian & Martin, Michael C.
Object Type: Article
System: The UNT Digital Library
Director of National Intelligence Statutory Authorities: Status and Proposals (open access)

Director of National Intelligence Statutory Authorities: Status and Proposals

This report reviews the congressional debate over authorities that occurred during consideration of the 2004 Act; examines the DNI's request for more authority and the congressional response to date; compares several of the DNI''s authorities with those of former DCI's; and, examines some potential Congressional concerns.
Date: November 2, 2007
Creator: Best, Richard A., Jr.; Cumming, Alfred & Masse, Todd
Object Type: Report
System: The UNT Digital Library
Estimate for GLAST LAT Milky Way Dark Matter WIMP Line Sensitivity (open access)

Estimate for GLAST LAT Milky Way Dark Matter WIMP Line Sensitivity

The LAT Dark Matter and New Physics Working group has been developing approaches for the indirect astrophysical detection of annihilation of dark matter. Our work has assumed that a significant component of dark matter is a new type of Weakly Interacting Massive Particle (WIMP). The annihilation of two WIMPs usually results in the production of many high energy gamma rays (>1 GeV) that can be well measured in the GLAST LAT if present. There is also the possibility to observe {gamma} lines from annihilation into {gamma}{gamma} and or {gamma}Z final states. In popular SUSY theories these line decays occur at the 10{sup -4} to 10{sup -2} branching fraction level. Estimates of LAT sensitivity (at 5{sigma} above background) and upper limits (upper limit at the 95% confidence level) to these WIMP lines will be presented. These sensitivities are given in photons/cm2/sec/sr and so do not depend on the WIMP models. However, they do depend on the diffuse background model. The latter is derived from GALPROP[1] based on EGRET and other data in the EGRET energy range. We use extrapolations, provided by the GALPROP team to the higher energy range of 150 GeV explored in the preliminary line sensitivity study presented here. …
Date: November 2, 2007
Creator: Edmonds, Y.; Baltz, E.; Bloom, E.; Cohen-Tanugi, J.; Godfrey, G.; Wai, L. et al.
Object Type: Article
System: The UNT Digital Library
Fault Geomechanics and Carbon Dioxide Leakage Applied to Geological Storage: FY07 Quarterly and Summary Reports (open access)

Fault Geomechanics and Carbon Dioxide Leakage Applied to Geological Storage: FY07 Quarterly and Summary Reports

Safe and permanent storage of carbon dioxide in geologic reservoirs is critical to geologic sequestration. The objective of this study is to quantify the conditions under which a general (simulated) fault network and a specific (field case) fault network will fail and leak carbon dioxide out of a reservoir. Faults present a potential fast-path for CO{sub 2} leakage from reservoirs to the surface. They also represent potential induced seismicity hazards. It is important to have improved quantitative understandings of the processes that trigger activity on faults and the risks they present. Fortunately, the conditions under which leakage along faults is induced can be predicted and quantified given the fault geometry, reservoir pressure, an in-situ stress tensor. We proposed to expand the current capabilities of fault threshold characterization and apply that capability to a site where is CO{sub 2} injection is active or planned. Specifically, we proposed to use a combination of discrete/explicit and continuum/implicit codes to provide constrain the conditions of fault failure. After minor enhancements of LLNL's existing codes (e.g., LDEC), we would create a 3D synthetic model of a common configuration (e.g., a faulted dome). During these steps, we will identify a field site where the necessary information …
Date: November 2, 2007
Creator: Friedmann, S. J. & Morris, J.
Object Type: Report
System: The UNT Digital Library
The GEANT4 Visualisation System (open access)

The GEANT4 Visualisation System

The Geant4 Visualization System is a multi-driver graphics system designed to serve the Geant4 Simulation Toolkit. It is aimed at the visualization of Geant4 data, primarily detector descriptions and simulated particle trajectories and hits. It can handle a variety of graphical technologies simultaneously and interchangeably, allowing the user to choose the visual representation most appropriate to requirements. It conforms to the low-level Geant4 abstract graphical user interfaces and introduces new abstract classes from which the various drivers are derived and that can be straightforwardly extended, for example, by the addition of a new driver. It makes use of an extendable class library of models and filters for data representation and selection. The Geant4 Visualization System supports a rich set of interactive commands based on the Geant4 command system. It is included in the Geant4 code distribution and maintained and documented like other components of Geant4.
Date: November 2, 2007
Creator: Allison, J.; Asai, M.; Barrand, G.; Donszelmann, M.; Minamimoto, K.; Tanaka, S. et al.
Object Type: Article
System: The UNT Digital Library
Heritage Areas: Background, Proposals, and Current Issues (open access)

Heritage Areas: Background, Proposals, and Current Issues

This report focuses on heritage areas designated by Congress, and related issues and legislation.
Date: November 2, 2007
Creator: Vincent, Carol H. & Whiteman, David L.
Object Type: Report
System: The UNT Digital Library
The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007), (open access)

The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007),

This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial {nu}{sub e}, {nu}{sub {mu}} and {nu}{sub {tau}} signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends IceCube's reach to lower energies. Before the deployment of IceTop, cosmic air showers were registered with the 30 station SPASE-2 surface array. IceCube's low noise Digital Optical Modules are very reliable, show a uniform response and record waveforms of arriving photons that are resolvable with nanosecond precision over a large dynamic range. Data acquisition, reconstruction and simulation …
Date: November 2, 2007
Creator: Collaboration, IceCube & Ackermann, M.
Object Type: Article
System: The UNT Digital Library
In Situ Immobilization of Uranium in Structured Porous Media via Biomineralization at the Fracture/Matrix Interface – Subproject to Co-PI Eric E. Roden (open access)

In Situ Immobilization of Uranium in Structured Porous Media via Biomineralization at the Fracture/Matrix Interface – Subproject to Co-PI Eric E. Roden

Although the biogeochemical processes underlying in situ bioremediation technologies are increasingly well understood, field-scale heterogeneity (both physical and biogeochemical) remains a major obstacle to successful field-scale implementation. In particular, slow release of contamination from low-permeability regions (primarily by diffusive/dispersive mass transfer) can hinder the effectiveness of remediation. The research described in this report was conducted in conjunction with a project entitled “In Situ Immobilization of Uranium in Structured Porous Media via Biomineralization at the Fracture/Matrix Interface”, which was funded through the Field Research element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. Timothy Scheibe (Pacific Northwest National Laboratory) was the overall PI/PD for the project, which included Scott Brooks (Oak Ridge National Laboratory) and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The overall goal of the project was to evaluate strategies that target bioremediation at interfaces between high- and low-permeability regions of an aquifer in order to minimize the rate of contaminant transfer into high-permeability/high fluid flow zones. The research was conducted at the Area 2 site of the Field Research Center (FRC) at Oak Ridge National Laboratory …
Date: November 2, 2007
Creator: Roden, Eric E.
Object Type: Report
System: The UNT Digital Library
Initial Commissioning Experience With the LCLS Injector (open access)

Initial Commissioning Experience With the LCLS Injector

The Linac Coherent Light Source (LCLS) is a SASE xray Free-Electron Laser (FEL) project presently under construction at SLAC [1]. The injector section, from drive-laser and RF photocathode gun through first bunch compressor chicane, was installed in fall 2006. Initial system commissioning with an electron beam is taking place during the spring and summer of 2007. The second phase of construction, including second bunch compressor and full linac, will begin later, in the fall of 2007. We report here on experience gained during the first phase of machine commissioning, including RF photocathode gun, linac booster section, S-band and X-band RF systems, first bunch compressor, and the various beam diagnostics.
Date: November 2, 2007
Creator: Akre, R.; Castro, J.; Ding, Y.; Dowell, D. H.; Emma, P.; Frisch, J. et al.
Object Type: Article
System: The UNT Digital Library
John B. Little Center Annual Symposium (open access)

John B. Little Center Annual Symposium

The Annual Symposium of the John B. Little Center for Radiation Sciences and Environmental Health at the Harvard School of Public Health seeks to educate radiobiologists and biomedical scientists in related areas on the leading research related to the effects of ionizing radiation and related environmental agents in biological systems. This effort seeks to further the training of individuals in this field, and to foment productive interactions and collaborations among scientists at Harvard and with other institutions. The Symposium attracts world-class scientists as speakers, and a broad cross-section of attendees from academic, government, and industrial research centers, as well as editorial staff from leading scientific publications. In order to maintain this quality, funding to support the travel and local expenses of invited speakers is sought, along with funds to allow use of appropriate conference facilities.
Date: November 2, 2007
Creator: Demple, Bruce F.
Object Type: Report
System: The UNT Digital Library
Kuwait: Security, Reform, and U.S. Policy (open access)

Kuwait: Security, Reform, and U.S. Policy

This report examines Kuwait, which would be pivotal to any U.S. decision to wind down its military involvement in Iraq, has advanced its democratic development since the fall of Saddam Hussein, but it remains concerned about security threats emanating from a still unstable Iraq. In June 2006 parliamentary elections, women voted and ran for the first time, but none won.
Date: November 2, 2007
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library