28 Matching Results

Search Results

Results: 1 - 24 next
open access

Nuclear Waste: Absence of Key Management Reforms on Hanford's Cleanup Project Adds to Challenges of Achieving Cost and Schedule Goals

Description: A letter report issued by the General Accounting Office with an abstract that begins "The Department of Energy's (DOE) Hanford Site in Washington State houses DOE's largest and most complex nuclear cleanup project--treating and preparing for disposal 55 million gallons of high-level radioactive waste. In 2000, DOE awarded an 11-year, $4.3 billion contract to design, construct, and test treatment facilities at Hanford. GAO was asked to review (1) efforts to accelerate the project's completion, (… more
Date: June 9, 2004
Creator: United States. General Accounting Office.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

DOD Travel Cards: Control Weaknesses Resulted in Millions of Dollars of Improper Payments

Description: A letter report issued by the General Accounting Office with an abstract that begins "Ineffective management and oversight of the Department of Defense's (DOD) premium class travel and unused airline tickets led to concerns about DOD's overall management of the centrally billed accounts. GAO was asked to determine whether (1) DOD improperly reimbursed travelers for airline tickets DOD paid for using centrally billed accounts, (2) internal controls were effective in preventing issuance of unauth… more
Date: June 9, 2004
Creator: United States. General Accounting Office.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

DOD Travel Cards: Control Weaknesses Led to Millions in Fraud, Waste, and Improper Payments

Description: Testimony issued by the General Accounting Office with an abstract that begins "In November 2003, GAO testified on the significant level of improper premium class travel purchased with centrally billed accounts. These findings led to concerns over the Department of Defense's (DOD) overall management of the centrally billed account program. At the request of this Committee, Senator Grassley, and Representative Schakowsky, GAO performed work to determine whether DOD controls were adequate to prot… more
Date: June 9, 2004
Creator: United States. General Accounting Office.
Item Type: Refine your search to only Text
Partner: UNT Libraries Government Documents Department
open access

Thermophotovoltaic Spectral Control

Description: Spectral control is a key technology for thermophotovoltaic (TPV) direct energy conversion systems because only a fraction (typically less than 25%) of the incident thermal radiation has energy exceeding the diode bandgap energy, E{sub g}, and can thus be converted to electricity. The goal for TPV spectral control in most applications is twofold: (1) Maximize TPV efficiency by minimizing transfer of low energy, below bandgap photons from the radiator to the TPV diode. (2) Maximize TPV surface p… more
Date: June 9, 2004
Creator: DePoy, D. M.; Fourspring, P. M.; Baldasaro, P. F.; Beausang, J. F.; Brown, E. J.; Dashiel, M. W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Analysis of Recombination Processes in 0.5-0.6 eV Epitaxial GaInAsSb Lattice-matched to GaSb

Description: This work summarizes recent data on minority carrier lifetime in n- and p-type double heterostructures (DHs) of 0.5-0.6 eV GaInAsSb confined with GaSb and AlGaAsSb cap layers. Recombination times were measured by time-resolved photoluminescence (TRPL) and by optical frequency response (OFR) to sinusoidal excitation. It was shown that one of the mechanisms responsible for interface recombination in GaSb/GaInAsSb/GaSb DHs is thermionic emission of carriers over the heterobarrier. Considerable imp… more
Date: June 9, 2004
Creator: Donetsky, D.; Anikeev, S.; Gu, N.; Belenky, G.; Luryi, S.; Wang, C. A. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Antimony Based III-V Thermophotovoltaic Devices

Description: Antimony-based III-V thermophotovoltaic (TPV) cells are attractive converters for systems with low radiator temperature around 1100 to 1700 K, since these cells potentially can be spectrally matched to the thermal source. Cells under development include GaSb and the lattice-matched GaInAsSb/GaSb and InPAsSb/InAs quaternary systems. GaSb cell technology is the most mature, owing in part to the relative ease in preparation of the binary alloy compared to quaternary GaInAsSb and InPAsSb alloys. De… more
Date: June 9, 2004
Creator: Wang, C. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Annotation of the Clostridium Acetobutylicum Genome

Description: The genome sequence of the solvent producing bacterium Clostridium acetobutylicum ATCC824, has been determined by the shotgun approach. The genome consists of a 3.94 Mb chromosome and a 192 kb megaplasmid that contains the majority of genes responsible for solvent production. Comparison of C. acetobutylicum to Bacillus subtilis reveals significant local conservation of gene order, which has not been seen in comparisons of other genomes with similar, or, in some cases, closer, phylogenetic proxi… more
Date: June 9, 2004
Creator: Daly, M. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final Technical Report for the Grant DF-FG02-03ER41236 Partial Support of CPO6, The Sixth International Charged-Particle Optics Conference

Description: The International Conference on Charged Particle Optics, CPO, is held every 4 years, and brings together scientists working in all areas of charged-particle optics including electron microscopy, accelerators, spectrometers, electron and ion sources, and theory. In October 2002 the sixth such conference, CPO6, was held near Washington, DC. This is the report on the Sixth International Charged-Particle Optics Conference. Proceedings of this conference have been published in Nuclear Instruments & … more
Date: June 9, 2004
Creator: Dragt, Alex J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of trade-off equations for EnergyStar windows

Description: The authors explore the feasibility of adding a performance option to DOE's EnergyStar{copyright} Windows program whereby windows of differing U-factors and SHGCs can qualify so long as they have equivalent annual energy performance. An iterative simulation procedure is used to calculate trade-off equations giving the change in SHGC needed to compensate for a change in U-factor. Of the four EnergyStar{copyright} Window climate zones, trade-off equations are possible only in the Northern and Sou… more
Date: June 9, 2004
Creator: Huang, Joe; Mitchell, Robin; Selkowitz, Steve; Arasteh, Dariush & Clear, Bob
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Quarkonia production with leptons and hadrons

Description: We discuss current issues and present the latest measurements on quarkonia production from experiments monitoring hadron-hadron and lepton-hadron collisions. These measurements include cross section and polarization results for charmonium and bottomonium states.
Date: June 9, 2004
Creator: Papadimitriou, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Upgrading the Linac 400 MeV Switchyard

Description: This note describes changes in the 400 MeV beam transfer system from the Linac to improve the quality of the beam delivered to the Booster and to add the capability to direct beam to the MuCool Test Area (MTA). The new configuration has two pairs of pulsed dipole magnets on each side of the 400 MeV electrostatic Chopper. The smaller pair deflects vertically to replace the kick of the Chopper to send the beam to the Booster while the larger pair deflects horizontally to transfer the beam to the … more
Date: June 9, 2004
Creator: al., Charles M Ankenbrandt et
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

System Performance Projections for TPV Energy Conversion

Description: TPV technology has advanced rapidly in the last five years, with diode conversion efficiency approaching >30%, and filter efficiency of {approx}80%. These achievements have enabled repeatable testing of 20% efficient small systems, demonstrating the potential of TPV energy conversion. Near term technology gains support a 25% efficient technology demonstration in the two year timeframe. However, testing of full size systems, which includes efficiency degradation mechanisms, such as: nonunifor… more
Date: June 9, 2004
Creator: Baldasaro, P. F.; Dashiell, M. W.; Oppenlander, J. E.; Vell, J. L.; Fourspring, P.; Rahner, K. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Real-Time Characterization of Virulence Factor Expression in Yersinia pestis Using a Green Fluorescent Protein Reporter System

Description: A real-time reporter system was developed to monitor the thermal induction of virulence factors in Yersinia pestis. The reporter system consists of a plasmid in Y. pestis in which the expression of green fluorescent protein (GFP) is under the control of the promoters for six virulence factors, yopE, sycE, yopK, yopT, yscN, and lcrE/yopN, which are all components of the Type III secretion virulence mechanism of Y. pestis. Induction of the expression of these genes in vivo was determined by the i… more
Date: June 9, 2004
Creator: Forde, C.; Rocco, J.; Fitch, J. P. & McCutchen-Maloney, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Applications of X-Ray Lasers Utilizing Plasmas that are only a Few Times Ionised

Description: With the advent of tabletop X-ray lasers that operate at high repetition rate more emphasis is being put on finding useful applications for these lasers. The 14.7 nm Ni-like Pd X-ray laser at Lawrence Livermore National Laboratory is being used to do many interferometer experiments. As detailed quantitative comparisons are done between experiments and code simulations it is clear that some of the assumptions used to analyze the experiments need to be modified as one explores plasmas that are on… more
Date: June 9, 2004
Creator: Nilsen, Joseph & Scofield, James H
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Experimental Confirmation of CH Mandrel Removal from Be Shells

Description: Sputtered Be shells are made by sputter deposition of Be, with a radially graded Cu dopant as necessary, onto plastic mandrels supplied by General Atomics. Although the plastic mandrel may not be a design issue, it is a fielding issue because at cryo temperatures the plastic shrinks more than the Be and delaminates. We described in previous memos a proposed method for thermally removing the plastic by burning it in air at elevated temperature. A key aspect to this process is getting air in and … more
Date: June 9, 2004
Creator: Cook, B; Letts, S & Buckley, S
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Global Environment Facility (GEF): Overview

Description: This report provides an overview about Global Environment Facility (GEF) which was established in 1991, has served since then as a primary source of funding for several major international environmental concern.
Date: June 9, 2004
Creator: Fletcher, Susan R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Cleanliness improvements of NIF (National Ignition Facility) amplifiers as compared to previous large-scale lasers

Description: Prior to the recent commissioning of the first NIF (National Ignition Facility) beamline, full-scale laser-amplifier-glass cleanliness experiments were performed. Aerosol measurements and obscuration data acquired using a modified flatbed scanner compare favorably to historical large-scale lasers and indicate that NIF is the cleanest large-scale laser built to date.
Date: June 9, 2004
Creator: Honig, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

High Performance InGaAsSb TPV Cells

Description: Lattice-matched 0.52 eV InGaAsSb/GaSb thermophotovoltaic (TPV) cells are grown using a multi-wafer metal-organic-chemical-vapor-deposition (MOCVD) system. MOCVD growth series of P/N junction epitaxial structures consisting of as many as 30 wafers demonstrate good run-to-run reproducibility, good uniformity across the wafer and exhibit high performance with open circuit voltages of {approx}300mV and fill factors of 70% at 25 C. Growth parameters, including temperature, surface preparation and su… more
Date: June 9, 2004
Creator: Shellenbarger, Zane A.; Taylor, Gordon C.; Martinelli, Ramon U. & Carpinelli, Joseph M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

0.52eV Quaternary InGaAsSb Thermophotovoltaic Diode Technology

Description: Thermophotovoltaic (TPV) diodes fabricated from 0.52eV lattice-matched InGaAsSb alloys are grown by Metal Organic Vapor Phase Epitaxy (MOVPE) on GaSb substrates. 4cm{sup 2} multi-chip diode modules with front-surface spectral filters were tested in a vacuum cavity and attained measured efficiency and power density of 19% and 0.58 W/cm{sup 2} respectively at operating at temperatures of T{sub radiator} = 950 C and T{sub diode} = 27 C. Device modeling and minority carrier lifetime measurements of… more
Date: June 9, 2004
Creator: Dashiell, M. W.; Beausang, J. F.; Nichols, G.; Depoy, D. M.; Danielson, L. R.; Ehsani, H. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen