Contracting Strategies: Data and Oversight Problems Hamper Opportunities to Leverage Value of Interagency and Enterprisewide Contracts (open access)

Contracting Strategies: Data and Oversight Problems Hamper Opportunities to Leverage Value of Interagency and Enterprisewide Contracts

A letter report issued by the Government Accountability Office with an abstract that begins "Agencies can use several different types of contracts to leverage the government's buying power for goods and services. These include interagency contracts--where one agency uses another's contract for its own needs--such as the General Services Administration (GSA) and the Department of Veterans Affairs multiple award schedule (MAS) contracts, multiagency contracts (MAC) for a wide range of goods and services, and governmentwide acquisition contracts (GWAC) for information technology. Agencies spent at least $60 billion in fiscal year 2008 through these contracts and similar single-agency enterprisewide contracts. However, concerns exist about duplication, oversight, and a lack of information on these contracts, and pricing and management of the MAS program. GAO was asked to assess the reasons for establishing and the policies to manage these contracts; the effectiveness of GSA tools for obtaining best MAS contract prices; and GSA's management of the MAS program. To do this, GAO reviewed statutes, regulations, policies, contract documentation and data, and interviewed officials from OMB and six agencies."
Date: April 29, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Auto Industry: Lessons Learned from Cash for Clunkers Program (open access)

Auto Industry: Lessons Learned from Cash for Clunkers Program

A letter report issued by the Government Accountability Office with an abstract that begins "In July and August 2009, the federal government implemented the Consumer Assistance to Recycle and Save (CARS) program, or "Cash for Clunkers," a temporary vehicle retirement program that offered consumers a monetary credit ($3,500 or $4,500) to trade in an older vehicle for a new, more fuel-efficient one. The National Highway Traffic Safety Administration (NHTSA) was responsible for administering the program, and GAO was required to review the program's administration. This report examines (1) what is known to date about the extent to which the CARS program achieved its objectives; (2) what stakeholders' experiences were with the CARS program; and (3) how the CARS program compares to other selected domestic and international vehicle retirement programs. To address these issues, GAO reviewed the CARS legislation and implementing regulations, a required NHTSA report to Congress on the program's efficacy, and CARS program transaction data. GAO also contacted officials from NHTSA and the Environmental Protection Agency (EPA); representatives of industry organizations and academics; as well as CARS program stakeholders, including representatives from consumer groups, scrap and salvage industries, automobile manufacturers, vehicle dealerships, and charities. GAO also interviewed officials from …
Date: April 29, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Nuclear Safety: Convention on Nuclear Safety Is Viewed by Most Member Countries as Strengthening Safety Worldwide (open access)

Nuclear Safety: Convention on Nuclear Safety Is Viewed by Most Member Countries as Strengthening Safety Worldwide

A letter report issued by the Government Accountability Office with an abstract that begins "Currently, 437 civilian nuclear power reactors are operating in 29 countries, and 56 more are under construction. After the Chernobyl accident, representatives of over 50 nations, including the United States, participated in the development of the Convention on Nuclear Safety, a treaty that seeks to promote the safety of civilian nuclear power reactors. The Convention has been in force since 1996. GAO was asked to assess (1) parties' views on the benefits and limitations of the Convention, (2) efforts to improve implementation of the Convention, and (3) how International Atomic Energy Agency (IAEA) programs complement the Convention's safety goals. GAO surveyed the 64 parties to the Convention for which it was in force at the time of GAO's review and analyzed the responses of the 32 that completed it, analyzed relevant documents, and interviewed U.S. and foreign officials."
Date: April 29, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Department of Veterans Affairs: Preliminary Observations on Issues Related to Contracting Opportunities for Veteran-owned Small Businesses (open access)

Department of Veterans Affairs: Preliminary Observations on Issues Related to Contracting Opportunities for Veteran-owned Small Businesses

Testimony issued by the Government Accountability Office with an abstract that begins "The Veterans Benefits, Health Care, and Information Technology Act of 2006 (the 2006 Act) requires the Department of Veterans Affairs (VA) to give priority to veteranowned and service-disabled veteran-owned small businesses (VOSB and SDVOSB) when awarding contracts to small businesses. This testimony discusses preliminary views on (1) the extent to which VA met its prime contracting goals for SDVOSBs and VOSBs in fiscal years 2007-2009, and (2) VA's progress in implementing procedures to verify the ownership, control, and veteran status of firms in its mandated database. GAO obtained and analyzed data on VA's contracting activities, and reviewed a sample of verified businesses to assess VA's verification program."
Date: April 29, 2010
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Metal-Organic Frameworks: Literature Survey and Recommendation of Potential Sorbent Materials (open access)

Metal-Organic Frameworks: Literature Survey and Recommendation of Potential Sorbent Materials

Metal-organic frameworks (MOFs) are a special type of porous material with a number of unique properties, including exceptionally high surface areas, large internal pore volumes (void space) and tunable pore sizes. These materials are prepared through the assembly of molecular building blocks into ordered three-dimensional structures. The bulk properties of the MOF are determined by the nature of the building blocks and, as such, these materials can be designed with special characteristics that cannot be realized in other sorbent materials, like activated carbons. For example, MOFs can be constructed with binding sites or pockets that can exhibit selectivity for specific analytes. Alternatively, the framework can be engineered to undergo reversible dimensional changes (or 'breathing') upon interaction with an analyte, effectively trapping the molecule of interest in the lattice structure. In this report, we have surveyed the 4000 different MOF structures reported in the open literature and provided recommendations for specific MOF materials that should be investigated as sorbents for this project.
Date: April 29, 2010
Creator: Baumann, T F
Object Type: Report
System: The UNT Digital Library
On the Performance of an Algebraic MultigridSolver on Multicore Clusters (open access)

On the Performance of an Algebraic MultigridSolver on Multicore Clusters

Algebraic multigrid (AMG) solvers have proven to be extremely efficient on distributed-memory architectures. However, when executed on modern multicore cluster architectures, we face new challenges that can significantly harm AMG's performance. We discuss our experiences on such an architecture and present a set of techniques that help users to overcome the associated problems, including thread and process pinning and correct memory associations. We have implemented most of the techniques in a MultiCore SUPport library (MCSup), which helps to map OpenMP applications to multicore machines. We present results using both an MPI-only and a hybrid MPI/OpenMP model.
Date: April 29, 2010
Creator: Baker, A H; Schulz, M & Yang, U M
Object Type: Article
System: The UNT Digital Library
STP-ECRTS - THERMAL AND GAS ANALYSES FOR SLUDGE TRANSPORT AND STORAGE CONTAINER (STSC) STORAGE AT T PLANT (open access)

STP-ECRTS - THERMAL AND GAS ANALYSES FOR SLUDGE TRANSPORT AND STORAGE CONTAINER (STSC) STORAGE AT T PLANT

The Sludge Treatment Project (STP) is responsible for the disposition of sludge contained in the six engineered containers and Settler tank within the 105-K West (KW) Basin. The STP is retrieving and transferring sludge from the Settler tank into engineered container SCS-CON-230. Then, the STP will retrieve and transfer sludge from the six engineered containers in the KW Basin directly into a Sludge Transport and Storage Containers (STSC) contained in a Sludge Transport System (STS) cask. The STSC/STS cask will be transported to T Plant for interim storage of the STSC. The STS cask will be loaded with an empty STSC and returned to the KW Basin for loading of additional sludge for transportation and interim storage at T Plant. CH2MHILL Plateau Remediation Company (CHPRC) contracted with Fauske & Associates, LLC (FAI) to perform thermal and gas generation analyses for interim storage of STP sludge in the Sludge Transport and Storage Container (STSCs) at T Plant. The sludge types considered are settler sludge and sludge originating from the floor of the KW Basin and stored in containers 210 and 220, which are bounding compositions. The conditions specified by CHPRC for analysis are provided in Section 5. The FAI report (FAI/10-83, …
Date: April 29, 2010
Creator: RD, CROWE; R, APTHORPE; SJ, LEE & MG, PLYS
Object Type: Report
System: The UNT Digital Library
Finite temperature spin-dynamics and phase transitions in spin-orbital models (open access)

Finite temperature spin-dynamics and phase transitions in spin-orbital models

We study finite temperature properties of a generic spin-orbital model relevant to transition metal compounds, having coupled quantum Heisenberg-spin and Ising-orbital degrees of freedom. The model system undergoes a phase transition, consistent with that of a 2D Ising model, to an orbitally ordered state at a temperature set by short-range magnetic order. At low temperatures the orbital degrees of freedom freeze-out and the model maps onto a quantum Heisenberg model. The onset of orbital excitations causes a rapid scrambling of the spin spectral weight away from coherent spin-waves, which leads to a sharp increase in uniform magnetic susceptibility just below the phase transition, reminiscent of the observed behavior in the Fe-pnictide materials.
Date: April 29, 2010
Creator: Chen, C. C.
Object Type: Article
System: The UNT Digital Library
Tunneling density of states as a function of thickness in superconductor/ strong ferromagnet bilayers (open access)

Tunneling density of states as a function of thickness in superconductor/ strong ferromagnet bilayers

We have made an experimental study of the tunneling density of states (DOS) in strong ferromagnetic thin films (CoFe) in proximity with a thick superconducting film (Nb) as a function of d{sub F}, the ferromagnetic thickness. Remarkably, we find that as d{sub F} increases, the superconducting DOS exhibits a scaling behavior in which the deviations from the normal-state conductance have a universal shape that decreases exponentially in amplitude with characteristic length d* {approx} 0.4 nm. We do not see oscillations in the DOS as a function of d{sub F}, as expected from predictions based on the Usadel equations, although an oscillation in T{sub c}(d{sub F}) has been seen in the same materials.
Date: April 29, 2010
Creator: Reymond, S.
Object Type: Article
System: The UNT Digital Library
A Southern Sky Survey with Fermi LAT and ASKAP (open access)

A Southern Sky Survey with Fermi LAT and ASKAP

We present the prospects for a future joint gamma-ray and radio survey of southern hemisphere sources using the Fermi Large Area Telescope (LAT) and the upcoming Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope. ASKAP is a next generation radio telescope designed to perform surveys at GHz frequencies at a much higher survey speed than previous radio telescopes, and is scheduled to start engineering observations in 2011. The survey capabilities of both Fermi LAT and ASKAP are described, and the planned science surveys for ASKAP are summarized. We give some expected details of the Variable and Slow Transient (VAST) survey using ASKAP, which will search for transients on timescales from 5 seconds to years. Some observational properties of faint and transient sources seen at gamma-ray and radio wavelengths are summarized, and prospects and strategies for using ASKAP survey data for LAT source counterpart identification are summarized.
Date: April 29, 2010
Creator: Cameron, Robert A. & /SLAC /KIPAC, Menlo Park
Object Type: Article
System: The UNT Digital Library
Origin of charge density at LaAlO3-on-SrTiO3 heterointerfacespossibility of intrinsic doping (open access)

Origin of charge density at LaAlO3-on-SrTiO3 heterointerfacespossibility of intrinsic doping

As discovered by Ohtomo et al., a large sheet charge density with high mobility exists at the interface between SrTiO{sub 3} and LaAlO{sub 3}. Based on transport, spectroscopic and oxygen-annealing experiments, we conclude that extrinsic defects in the form of oxygen vacancies introduced by the pulsed laser deposition process used by all researchers to date to make these samples is the source of the large carrier densities. Annealing experiments show a limiting carrier density. We also present a model that explains the high mobility based on carrier redistribution due to an increased dielectric constant.
Date: April 29, 2010
Creator: Siemons, W.
Object Type: Article
System: The UNT Digital Library
MEASUREMENTS OF DIRECT CP VIOLATION AND CONSTRAINT ON THE CKM TRIANGLE IN B->K*pi DECAYS (open access)

MEASUREMENTS OF DIRECT CP VIOLATION AND CONSTRAINT ON THE CKM TRIANGLE IN B->K*pi DECAYS

We constrain the apex of the Cabibbo-Kobayashi-Maskawa unitarity triangle with measurements of B {yields} K*{pi} amplitudes from analyses of B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} and B{sup 0} {yields} K{sub S}{pi}{sup +}{pi}{sup -} decays. This constraint is consistent with the world average. The B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} decay mode is reconstructed from a sample of 454 million B{sup 0}{bar B}{sup 0} events collected by the BABAR detector at SLAC. We measure direct CP violation in B{sup 0} {yields} K*{sup +}{pi}{sup -} decays at the level of 3{sigma} when measurements from both B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} and B{sup 0} {yields} K{sub S}{pi}{sup +}{pi}{sup -} decays are combined.
Date: April 29, 2010
Creator: Wagner, Andrew Phillips
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Quasi-zero dimensional CuB2O4: a resonant inelastic X-ray scattering case study (open access)

Quasi-zero dimensional CuB2O4: a resonant inelastic X-ray scattering case study

We explore the general phenomenology of resonant inelastic scattering (RIXS) using CuB{sub 2}O{sub 4}, a network of CuO{sub 4} plaquettes electronically isolated by B{sup +3} ions. Spectra show a small number of well-separated features, and we exploit the simple electronic structure to explore RIXS phenomenology by developing a calculation which allows for intermediate-state effects ignored in standard approaches. These effects are found to be non-negligible and good correspondence between our model and experiment leads to a simple picture of such phenomenology as the genesis of d {yields} d excitations at the K edge and intermediate-state interference effects.
Date: April 29, 2010
Creator: Hancock, J.N.
Object Type: Article
System: The UNT Digital Library
Introduction to Extra Dimensions (open access)

Introduction to Extra Dimensions

Extra dimensions provide a very useful tool in addressing a number of the fundamental problems faced by the Standard Model. The following provides a very basic introduction to this very broad subject area as given at the VIII School of the Gravitational and Mathematical Physics Division of the Mexican Physical Society in December 2009. Some prospects for extra dimensional searches at the 7 TeV LHC with {approx}1 fb{sup -1} of integrated luminosity are provided.
Date: April 29, 2010
Creator: Rizzo, Thomas G.
Object Type: Article
System: The UNT Digital Library
Limits on tau lepton flavor violating decays in three charged leptons (open access)

Limits on tau lepton flavor violating decays in three charged leptons

A search for the neutrinoless, lepton-flavor violating decay of the {tau} lepton into three charged leptons has been performed using an integrated luminosity of 468 fb{sup -1} collected with the BABAR detector at the PEP-II collider. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1.8-3.3) x 10{sup -8} at 90% confidence level.
Date: April 29, 2010
Creator: Cervelli, Alberto
Object Type: Article
System: The UNT Digital Library
AdS/QCD, LIight-Front Holography, and the Non-perturbative Running Coupling (open access)

AdS/QCD, LIight-Front Holography, and the Non-perturbative Running Coupling

The combination of Anti-de Sitter space (AdS) methods with light-front (LF) holography provides a remarkably accurate first approximation for the spectra and wavefunctions of meson and baryon light-quark bound states. The resulting bound-state Hamiltonian equation of motion in QCD leads to relativistic light-front wave equations in terms of an invariant impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. These equations of motion in physical space-time are equivalent to the equations of motion which describe the propagation of spin-J modes in anti-de Sitter (AdS) space. The eigenvalues give the hadronic spectrum, and the eigenmodes represent the probability distributions of the hadronic constituents at a given scale. A positive-sign confining dilaton background modifying AdS space gives a very good account of meson and baryon spectroscopy and form factors. The light-front holographic mapping of this model also leads to a non-perturbative effective coupling {alpha}{sub s}{sup Ads} (Q{sup 2}) which agrees with the effective charge defined by the Bjorken sum rule and lattice simulations. It displays a transition from perturbative to nonperturbative conformal regimes at a momentum scale {approx} 1 GeV. The resulting {beta}-function appears to capture the essential characteristics of the …
Date: April 29, 2010
Creator: Brodsky, Stanley J.; de Teramond, Guy & Deur, Alexandre
Object Type: Article
System: The UNT Digital Library
Radiation Protection Studies for LCLS Tune Up Dump (open access)

Radiation Protection Studies for LCLS Tune Up Dump

The Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center is a pioneer fourth generation hard x-ray free electron laser that shall start to deliver laser pulses in 2009. Among other components of LCLS that present radiation protection concerns, the tune up dump (tdund) is of special interest because it also constitutes an issue for machine protection, as it is placed close to radiation sensitive components, like electronic devices and permanent magnets in the undulators. This paper first introduces the stopper of tdund looking at the heat load, and then it describes the shielding around the dump necessary to maintain the prompt and residual dose within design values. Next, preliminary comparisons of the magnetization loss in a dedicated on-site magnet irradiation experiment with FLUKA simulations serve to characterize the magnetic response to radiation of magnets like those of LCLS. The previous knowledge, together with the limit for the allowed demagnetization, are used to estimate the lifetime of the undulator. Further simulations provide guidelines on which lifetime can be expected for an electronic device placed at a given distance of tdund.
Date: April 29, 2010
Creator: Santana-Leitner, M.; Fass, A.; Mao, S.; Nuhn, H. D.; Roesler, S.; Rokni, S. et al.
Object Type: Article
System: The UNT Digital Library
A momentum-dependent perspective on quasiparticleinterference in Bi2Sr2CaCu2O_8+delta (open access)

A momentum-dependent perspective on quasiparticleinterference in Bi2Sr2CaCu2O_8+delta

Angle Resolved Photoemission Spectroscopy (ARPES) probes the momentum-space electronic structure of materials, and provides invaluable information about the high-temperature superconducting cuprates. Likewise, cuprates real-space, inhomogeneous electronic structure is elucidated by Scanning Tunneling Spectroscopy (STS). Recently, STS has exploited quasiparticle interference (QPI) - wave-like electrons scattering off impurities to produce periodic interference patterns - to infer properties of the QP in momentum-space. Surprisingly, some interference peaks in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi-2212) are absent beyond the antiferromagnetic (AF) zone boundary, implying the dominance of particular scattering process. Here, we show that ARPES sees no evidence of quasiparticle (QP) extinction: QP-like peaks are measured everywhere on the Fermi surface, evolving smoothly across the AF zone boundary. This apparent contradiction stems from different natures of single-particle (ARPES) and two-particle (STS) processes underlying these probes. Using a simple model, we demonstrate extinction of QPI without implying the loss of QP beyond the AF zone boundary.
Date: April 29, 2010
Creator: Vishik, I. M.
Object Type: Article
System: The UNT Digital Library
Evidence for weak electronic correlations in Fe-pnictides (open access)

Evidence for weak electronic correlations in Fe-pnictides

Using x-ray absorption and resonant inelastic x-ray scattering, charge dynamics at and near the Fe L edges is investigated in Fe pnictide materials, and contrasted to that measured in other Fe compounds. It is shown that the XAS and RIXS spectra for 122 and 1111 Fe pnictides are each qualitatively similar to Fe metal. Cluster diagonalization, multiplet, and density-functional calculations show that Coulomb correlations are much smaller than in the cuprates, highlighting the role of Fe metallicity and strong covalency in these materials. Best agreement with experiment is obtained using Hubbard parameters U {approx}< 2eV and J {approx} 0.8eV.
Date: April 29, 2010
Creator: Yang, W.L.
Object Type: Article
System: The UNT Digital Library
Probing the pairing symmetry of the iron pnictides with electronic Raman scattering (open access)

Probing the pairing symmetry of the iron pnictides with electronic Raman scattering

An important issue in the study of the iron-arsenic based superconductors is the symmetry of the superconducting gap, a problem complicated by multiple gaps on different Fermi surface sheets. Electronic Raman scattering is a flexible bulk probe which allows one in principle to determine gap magnitudes and test for gap nodes in different regions of the Brillouin zone by employing different photon polarization states. Here we calculate the clean Raman intensity for A{sub 1g}, B{sub 1g} and B{sub 2g} polarizations, and discuss the peak structures and low-energy power laws which might be expected for several popular models of the superconducting gap in these systems.
Date: April 29, 2010
Creator: Boyd, G.R.
Object Type: Article
System: The UNT Digital Library
Assistance to Firefighters Program: Distribution of Fire Grant Funding (open access)

Assistance to Firefighters Program: Distribution of Fire Grant Funding

This report discusses the Assistance to Firefighters Grant (AFG) Program, also known as fire grants of the FIRE Act grant program, which provides federal grants directly to local fire departments and unaffiliated Emergency Medical Services (EMS) organizations to help address a variety of equipment, training, and other firefighter-related and EMS needs. This report also discusses the possible reauthorization of AFG and the related Staffing for Adequate Fire and Emergency Response Firefighters (SAFER) program.
Date: April 29, 2010
Creator: Kruger, Lennard G.
Object Type: Report
System: The UNT Digital Library
Federal Evacuation Policy: Issues for Congress (open access)

Federal Evacuation Policy: Issues for Congress

This report discusses federal evacuation policy and analyzes potential lessons learned from the evacuations of individuals in response to the Gulf Coast hurricanes of 2005. It also highlights several issue areas that might arise concerning potential lawmaking and oversight on evacuation policy.
Date: April 29, 2010
Creator: Lindsay, Bruce R.
Object Type: Report
System: The UNT Digital Library
Burma's 2010 Elections: Implications of the New Constitution and Election Laws (open access)

Burma's 2010 Elections: Implications of the New Constitution and Election Laws

This report discusses the November 7, 2010 parliamentary elections in Burma, which have long been controversial, mainly due to election fraud concerns. The report discusses debates about U.S. policy toward Burma, which has been sparked by the elections and the issues surrounding them.
Date: April 29, 2010
Creator: Martin, Michael F.
Object Type: Report
System: The UNT Digital Library
Gamma Spectrum from Neutron Capture on Tungsten Isotopes (open access)

Gamma Spectrum from Neutron Capture on Tungsten Isotopes

An evaluation of thermal neutron capture on the stable tungsten isotopes is presented, with preliminary results for the compound systems 183;184;185;187W. The evaluation procedure compares the g-ray cross-section data collected at the Budapest reactor, with Monte Carlo simulations of g-ray emission following the thermal neutron-capture process. The statistical-decay code DICEBOX was used for the Monte Carlo simulations. The evaluation yields new gamma rays in 185W and the confirmation of spins in 187W, raising the number of levels below which the level schemes are considered complete, thus increasing the number of levels that can be used in neutron data libraries.
Date: April 29, 2010
Creator: Hurst, Aaron; Summers, Neil; Sleaford, Brad; Firestone, Richard B; Belgya, T. & Revay, Z.S.
Object Type: Article
System: The UNT Digital Library