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766 Matching Results
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Fusion Energy: Definitive Cost Estimates for U.S. Contributions to an International Experimental Reactor and Better Coordinated DOE Research Are Needed
A letter report issued by the Government Accountability Office with an abstract that begins "The United States is pursuing two paths to fusion energy--magnetic and inertial. On November 21, 2006, the United States signed an agreement with five countries and the European Union to build and operate the International Thermonuclear Experimental Reactor (ITER) in Cadarache, France, to demonstrate the feasibility of magnetic fusion energy. The United States also built and operates facilities to pursue inertial fusion energy research. This report discusses (1) U.S. contributions to ITER and the challenges, if any, in managing this international fusion program and (2) the Department of Energy's (DOE) management of alternative fusion research activities, including National Nuclear Security Administration (NNSA) initiatives. In performing this work, GAO analyzed budget documents, briefings, and reports that focused on research and funding priorities for the fusion program. GAO also met with officials from DOE, NNSA, and the ITER Organization in France."
Date:
October 26, 2007
Creator:
United States. Government Accountability Office.
Object Type:
Report
System:
The UNT Digital Library
Energy Efficiency: Important Challenges Must Be Overcome to Realize Significant Opportunities for Energy Efficiency Improvements in Gulf Coast Reconstruction
A letter report issued by the Government Accountability Office with an abstract that begins "Following several hurricanes in 2005, the need to rebuild and repair destroyed and damaged homes and buildings in the Gulf Coast region may create opportunities for making energy efficiency improvements and realizing energy cost savings. While numerous federal agencies are involved in the recovery process, the Department of Housing and Urban Development (HUD) and the Department of Energy (DOE) interact with the states on a regular basis regarding matters of energy efficiency. This report, initiated under the authority of the Comptroller General of the United States, examines (1) the extent of opportunities for incorporating energy efficiency improvements in the Gulf Coast reconstruction, (2) potential challenges to realizing the energy cost savings during the reconstruction, and (3) the role of HUD and DOE in promoting energy efficiency in the rebuilding of the Gulf Coast. GAO limited the scope of its work to Louisiana and Mississippi since these states experienced the majority of the hurricane damage. GAO assessed opportunities for incorporating energy efficiency measures by conducting site visits and interviewing federal, state government officials; home builders; and energy efficiency experts. GAO also worked with a DOE national laboratory …
Date:
June 26, 2007
Creator:
United States. Government Accountability Office.
Object Type:
Report
System:
The UNT Digital Library
WAS Release 4 - Usability Test Results
This report discusses the usability test results for the Web-at-Risk project at the University of North Texas (UNT). Usability testing of the Web Archiving Service (WAS) Release 4 was conducted on May 29, 2007. Eight of the project's curators participated in test sessions, which generally were completed in 45-60 minutes. Two testing teams, each consisting of a facilitator and two observers were involved in testing.
Date:
June 26, 2007
Creator:
Murray, Kathleen R.
Object Type:
Report
System:
The UNT Digital Library
Book Review Geostatistical Analysis of Compositional Data
Compositional data are represented as vector variables with individual vector components ranging between zero and a positive maximum value representing a constant sum constraint, usually unity (or 100 percent). The earth sciences are flooded with spatial distributions of compositional data, such as concentrations of major ion constituents in natural waters (e.g. mole, mass, or volume fractions), mineral percentages, ore grades, or proportions of mutually exclusive categories (e.g. a water-oil-rock system). While geostatistical techniques have become popular in earth science applications since the 1970s, very little attention has been paid to the unique mathematical properties of geostatistical formulations involving compositional variables. The book 'Geostatistical Analysis of Compositional Data' by Vera Pawlowsky-Glahn and Ricardo Olea (Oxford University Press, 2004), unlike any previous book on geostatistics, directly confronts the mathematical difficulties inherent to applying geostatistics to compositional variables. The book righteously justifies itself with prodigious referencing to previous work addressing nonsensical ranges of estimated values and error, spurious correlation, and singular cross-covariance matrices.
Date:
March 26, 2007
Creator:
Carle, S F
Object Type:
Article
System:
The UNT Digital Library
Characterization of an AO-OCT system
Adaptive optics (AO) and optical coherence tomography (OCT) are powerful imaging modalities that, when combined, can provide high-volumetric-resolution, images of the retina. The AO-OCT system at UC Davis has been under development for 2 years and has demonstrated the utility of this technology for microscopic, volumetric, in vivo retinal imaging [1]. The current system uses an AOptix bimorph deformable mirror (DM) for low-order, high-stroke correction [2] and a 140-actuator Boston Micromachines DM for high-order correction [3]. We are beginning to investigate the potential for increasing the image contrast in this system using higher-order wavefront correction. The first step in this analysis is to quantify the residual wavefront error (WFE) in the current system. Developing an error budget is a common tool for improved performance and system design in astronomical AO systems [4, 5]. The process for vision science systems is also discussed in several texts e.g. [6], but results from this type of analysis have rarely been included in journal articles on AO for vision science. Careful characterization of the AO system will lead to improved performance and inform the design of a future high-contrast system. In general, an AO system error budget must include an analysis of three categories …
Date:
July 26, 2007
Creator:
Evans, J. W.; Zawadzki, R. J.; Jones, S.; Olivier, S. & Werner, J. S.
Object Type:
Article
System:
The UNT Digital Library
3H(d,n)4He S-factor from Ab Initio Overlap Functions
None
Date:
September 26, 2007
Creator:
Navratil, P; Thompson, I & Ormand, E
Object Type:
Report
System:
The UNT Digital Library
ELECTRICAL SAFETY IMPROVEMENT PROJECT A COMPLEX WIDE TEAMING INITIATIVE
This paper describes the results of a year-long project, sponsored by the Energy Facility Contractors Group (EFCOG) and designed to improve overall electrical safety performance throughout Department of Energy (DOE)-owned sites and laboratories. As evidenced by focused metrics, the Project was successful primarily due to the joint commitment of contractor and DOE electrical safety experts, as well as significant support from DOE and contractor senior management. The effort was managed by an assigned project manager, using classical project-management principles that included execution of key deliverables and regular status reports to the Project sponsor. At the conclusion of the Project, the DOE not only realized measurable improvement in the safety of their workers, but also had access to valuable resources that will enable them to do the following: evaluate and improve electrical safety programs; analyze and trend electrical safety events; increase electrical safety awareness for both electrical and non-electrical workers; and participate in ongoing processes dedicated to continued improvement.
Date:
November 26, 2007
Creator:
BJ, GRAY
Object Type:
Article
System:
The UNT Digital Library
Multiplexed Molecular Assays for Rapid Rule-Out of Foot-and-Mouth Disease
A nucleic acid-based multiplexed assay was developed that combines detection of foot-and-mouth disease virus (FMDV) with rule-out assays for two other foreign animal diseases and four domestic animal diseases that cause vesicular or ulcerative lesions indistinguishable from FMDV infection in cattle, sheep and swine. The FMDV 'look-alike' diagnostic assay panel contains five PCR and twelve reverse transcriptase PCR (RT-PCR) signatures for a total of seventeen simultaneous PCR amplifications for seven diseases plus incorporating four internal assay controls. It was developed and optimized to amplify both DNA and RNA viruses simultaneously in a single tube and employs Luminex{trademark} liquid array technology. Assay development including selection of appropriate controls, a comparison of signature performance in single and multiplex testing against target nucleic acids, as well of limits of detection for each of the individual signatures is presented. While this assay is a prototype and by no means a comprehensive test for FMDV 'look-alike' viruses, an assay of this type is envisioned to have benefit to a laboratory network in routine surveillance and possibly for post-outbreak proof of freedom from foot-and-mouth disease.
Date:
June 26, 2007
Creator:
Lenhoff, R; Naraghi-Arani, P; Thissen, J; Olivas, J; Carillo, C; Chinn, C et al.
Object Type:
Article
System:
The UNT Digital Library
Hanford Site Environmental Surveillance Data Report for Calendar Year 2006
This document includes tables of analytical data for Hanford Site environmental surveillance samples collected in 2006.
Date:
September 26, 2007
Creator:
Bisping, Lynn E.
Object Type:
Report
System:
The UNT Digital Library
PDV Probe Alignment Technique
This alignment technique was developed while performing heterodyne velocimetry measurements at LLNL. There are a few minor items needed, such as a white card with aperture in center, visible alignment laser, IR back reflection meter, and a microscope to view the bridge surface. The work was performed on KCP flyers that were 6 and 8 mils wide. The probes used were Oz Optics manufactured with focal distances of 42mm and 26mm. Both probes provide a spot size of approximately 80?m at 1550nm. The 42mm probes were specified to provide an internal back reflection of -35 to -40dB, and the probe back reflections were measured to be -37dB and -33dB. The 26mm probes were specified as -30dB and both measured -30.5dB. The probe is initially aligned normal to the flyer/bridge surface. This provides a very high return signal, up to -2dB, due to the bridge reflectivity. A white card with a hole in the center as an aperture can be used to check the reflected beam position relative to the probe and launch beam, and the alignment laser spot centered on the bridge, see Figure 1 and Figure 2. The IR back reflection meter is used to measure the dB return …
Date:
October 26, 2007
Creator:
Whitworth, T L; May, C M & Strand, O T
Object Type:
Report
System:
The UNT Digital Library
Colliding with a crunching bubble
In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.
Date:
March 26, 2007
Creator:
Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T. & Shenker, Stephen
Object Type:
Article
System:
The UNT Digital Library
Green (2(omega)) Laser Beam propagation in high-temperature Hohlraum Plasmas
We demonstrate propagation and small backscatter losses of a frequency-doubled (2{omega}) laser beam interacting with inertial confinement fusion hohlraum plasmas. The electron temperature of 3.3 keV, approximately a factor of two higher than achieved in previous experiments with open geometry targets, approaches plasma conditions of high-fusion yield hohlraums. In this new temperature regime, we measure 2{omega} laser beam transmission approaching 80% with simultaneous backscattering losses of less than 10%. These findings suggests that good laser coupling into fusion hohlraums using 2{omega} light is possible.
Date:
October 26, 2007
Creator:
Niemann, C; Berger, R; Divol, L; Froula, D H; Jones, O S; Kirkwood, R K et al.
Object Type:
Article
System:
The UNT Digital Library
Full-Process Computer Model of Magnetron Sputter, Part I: Test Existing State-of-Art Components
This work is part of a larger project to develop a modeling capability for magnetron sputter deposition. The process is divided into four steps: plasma transport, target sputter, neutral gas and sputtered atom transport, and film growth, shown schematically in Fig. 1. Each of these is simulated separately in this Part 1 of the project, which is jointly funded between CMLS and Engineering. The Engineering portion is the plasma modeling, in step 1. The plasma modeling was performed using the Object-Oriented Particle-In-Cell code (OOPIC) from UC Berkeley [1]. Figure 2 shows the electron density in the simulated region, using magnetic field strength input from experiments by Bohlmark [2], where a scale of 1% is used. Figures 3 and 4 depict the magnetic field components that were generated using two-dimensional linear interpolation of Bohlmark's experimental data. The goal of the overall modeling tool is to understand, and later predict, relationships between parameters of film deposition we can change (such as gas pressure, gun voltage, and target-substrate distance) and key properties of the results (such as film stress, density, and stoichiometry.) The simulation must use existing codes, either open-source or low-cost, not develop new codes. In part 1 (FY07) we identified and …
Date:
September 26, 2007
Creator:
Walton, C. C.; Gilmer, G. H.; Wemhoff, A. P. & Zepeda-Ruiz, L. A.
Object Type:
Report
System:
The UNT Digital Library
Thoughts on Verification of Nuclear Disarmament
It is my pleasure to be here to day to participate in this Conference. My thanks to the organizers for preparing such an interesting agenda on a very difficult topic. My effort in preparing my presentation was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. And as many of you know Lawrence Livermore National Laboratory is now, as of Oct 1st, under contract to the Lawrence Livermore National Security LLC. There has been a long history of how to view verification of arms control agreements. The basis for verification during the days of SALT was that verification would be based on each country's national technical means. For treaties dealing with strategic missiles this worked well as the individual items subject to verification were of such a size that they were visible by the National Technical Means available at the time. And it was felt that the counting of missiles and launchers could be verified by our National Technical Means. For nuclear testing treaties the use of seismic measurements developed into a capability that was reasonably robust for all but the smallest of nuclear tests. However, once we …
Date:
September 26, 2007
Creator:
Dunlop, W H
Object Type:
Article
System:
The UNT Digital Library
An Octadentate Luminescent Eu(III) 1,2-HOPO Chelate with PotentAqueous Stability
None
Date:
February 26, 2007
Creator:
Moore, Evan G.; Jocher, Christoph J.; Xu, Jide; Werner, Eric J. & Raymond,Kenneth N.
Object Type:
Article
System:
The UNT Digital Library
Poland Becoming a Member of the Global Nuclear Energy Partnership, Vol. 1.
Within a constrained carbon environment, the risks of future natural gas supply, and the need to move to market-based electricity prices, the study team found: (1) the deployment of new nuclear energy in Poland itself is very competitive in the next decade or two; (2) if such generation could be made available to Poland prior to deployment of its own nuclear generation facilities, Poland would benefit from partnering with its Baltic neighbors to import electricity derived from new nuclear generation facilities sited in Lithuania; and (3) Poland appears to be a good candidate for a partnership in the Global Nuclear Energy Partnership (GNEP) as an emerging nuclear energy country.
Date:
March 26, 2007
Creator:
Koritarov, V. K.; Conzelmann, G.; Cirillo, R. R. & Goldberg, S. M.
Object Type:
Report
System:
The UNT Digital Library
Remaining Sites Verification Package for the 1607-F3 Sanitary Sewer System, Waste Site Reclassification Form 2006-047
The 1607-F3 waste site is the former location of the sanitary sewer system that supported the 182-F Pump Station, the 183-F Water Treatment Plant, and the 151-F Substation. The sanitary sewer system included a septic tank, drain field, and associated pipeline, all in use between 1944 and 1965. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date:
April 26, 2007
Creator:
Dittmer, L. M.
Object Type:
Report
System:
The UNT Digital Library
Detailed Comparison of Blast Effects in Air and Vacuum
Although blast mitigation is most often achieved with solid shielding, ambient gas pressure can also affect the coupling of shock waves to solid targets. In this work the role of air as an energy transfer medium was examined experimentally by subjecting identical large-area rectangular witness plates to short-range blast effects in air and vacuum ({approx}50 mtorr) at 25 C. The expanding reactant front of 3 kg C4 charges was observed by fast camera to be cylindrically symmetric in both air and vacuum. The horizontal component of the reactant cloud velocity (perpendicular to the witness plates) was constant in both cases, with values of 3.0 and 5.9 km/s for air and vacuum, respectively. As a result of the blast, witness plates were plastically deformed into a shallow dish geometry, with local maxima 30 and 20 mm deep for air and vacuum, respectively. The average plate deflection from the air blast was 11 mm, {approx}10% deeper than the average vacuum plate deflection. Shock pressure estimates were made with a simple impedance-matching model, and indicate peak values in the 30-50 MPa range are consistent with the reactant cloud density and velocity. However, more detailed analysis is necessary to definitely establish the mechanisms by …
Date:
July 26, 2007
Creator:
Tringe, J W; Molitoris, J D; Garza, R G; Andreski, H G; Batteux, J D; Lauderbach, L M et al.
Object Type:
Article
System:
The UNT Digital Library
Examination of Scattering Volume Aligment in Thomson Scattering Off of a Shock Front in Argon
Thomson scattering in argon gas successfully probed the region of plasma just behind the shock front. The instantaneous shock velocity can be inferred from the duration of the signal, taking into account the size and shape of the scattering volume. Possible misalignment of the probe beam and spectrometer slits greatly affects the size and shape of the scattering volume, and therefore affects the calculation of the instantaneous shock velocity.
Date:
July 26, 2007
Creator:
Reighard, A. B.; Froula, D. H.; Drake, R. P.; Ross, J. S. & Divol, L.
Object Type:
Article
System:
The UNT Digital Library
Abrupt onset of a second energy gap at the superconducting transition of underdoped Bi2212
he superconducting gap--an energy scale tied to the superconducting phenomena--opens on the Fermi surface at the superconducting transition temperature (Tc) in conventional BCS superconductors. In underdoped high-Tc superconducting copper oxides, a pseudogap (whose relation to the superconducting gap remains a mystery) develops well above Tc (refs 1, 2). Whether the pseudogap is a distinct phenomenon or the incoherent continuation of the superconducting gap above Tc is one of the central questions in high-Tc research3, 4, 5, 6, 7, 8. Although some experimental evidence suggests that the two gaps are distinct9, 10, 11, 12, 13, 14, 15, 16, 17, 18, this issue is still under intense debate. A crucial piece of evidence to firmly establish this two-gap picture is still missing: a direct and unambiguous observation of a single-particle gap tied to the superconducting transition as function of temperature. Here we report the discovery of such an energy gap in underdoped Bi2Sr2CaCu2O8+delta in the momentum space region overlooked in previous measurements. Near the diagonal of Cu?O bond direction (nodal direction), we found a gap that opens at Tc and has a canonical (BCS-like) temperature dependence accompanied by the appearance of the so-called Bogoliubov quasi-particles, a classical signature of superconductivity. This is …
Date:
May 26, 2007
Creator:
Hussain, Zahid; Lee, W. S.; Vishik, I. M.; Tanaka, K.; Lu, D. H.; Sasagawa, T. et al.
Object Type:
Article
System:
The UNT Digital Library
REMOTE IN-CELL SAMPLING IMPROVEMENTS PROGRAM AT THESAVANNAH RIVER SITE (SRS) DEFENSE WASTE PROCESSING FACILITY (DWPF)
Remote Systems Engineering (RSE) of the Savannah River National Lab (SRNL) in combination with the Defense Waste Processing Facility(DWPF) Engineering and Operations has evaluated the existing equipment and processes used in the facility sample cells for 'pulling' samples from the radioactive waste stream and performing equipment in-cell repairs/replacements. RSE has designed and tested equipment for improving remote in-cell sampling evolutions and reducing the time required for in-cell maintenance of existing equipment. The equipment within the present process tank sampling system has been in constant use since the facility start-up over 17 years ago. At present, the method for taking samples within the sample cells produces excessive maintenance and downtime due to frequent failures relative to the sampling station equipment and manipulator. Location and orientation of many sampling stations within the sample cells is not conducive to manipulator operation. The overextension of manipulators required to perform many in-cell operations is a major cause of manipulator failures. To improve sampling operations and reduce downtime due to equipment maintenance, a Portable Sampling Station (PSS), wireless in-cell cameras, and new commercially available sampling technology has been designed, developed and/or adapted and tested. The uniqueness of the design(s), the results of the scoping tests, and …
Date:
November 26, 2007
Creator:
Marzolf, A
Object Type:
Article
System:
The UNT Digital Library
Poland Becoming a Member of the Global Nuclear Energy Partnership, Vol. 2.
Within a constrained carbon environment, the risks of future natural gas supply, and the need to move to market-based electricity prices, the study team found: (1) the deployment of new nuclear energy in Poland itself is very competitive in the next decade or two; (2) if such generation could be made available to Poland prior to deployment of its own nuclear generation facilities, Poland would benefit from partnering with its Baltic neighbors to import electricity derived from new nuclear generation facilities sited in Lithuania; and (3) Poland appears to be a good candidate for a partnership in the Global Nuclear Energy Partnership (GNEP) as an emerging nuclear energy country.
Date:
March 26, 2007
Creator:
Koritarov, V. K.; Conzelmann, G.; Cirillo, R. R. & Goldberg, S. M.
Object Type:
Report
System:
The UNT Digital Library
Remarkable Strontium B-Site Occupancy in FerroelectricPb(Zr1-xTix)O3 Solid Solutions Doped with Cryolite-Type StrontiumNiobate
New high-performance ferroelectric materials based on Pb(Zr{sub 1-x}Ti{sub x})O{sub 3} (PZT) that are doped with cryolite-type strontium niobate (SNO, Sr{sub 4}(Sr{sub 2-2y/3}Nb{sub 2+2y/3})O{sub 11+y}V{sub 0,1-y} with 0 {le} y {le} 1), hence denoted PZT:SNO, and their microscopic structure are described. The combination of exceptional piezoelectric properties, i.e. a piezoelectric strain constant of d{sub 33} {approx} 760 pm/V, with excellent stability and degradation resistance makes ferroelectric PZT:SNO solid solutions very attractive for use in novel and innovative piezoelectric actuator and transducer applications. Extended X-ray absorption fine-structure (EXAFS) analyses of PZT:SNO samples revealed that {approx}10 % of the Sr cations occupy the nominal B-sites of the perovskite-type PZT host lattice. This result was supported by EXAFS analyses of both a canonical SrTiO{sub 3} perovskite and two SNO model and reference compounds. Fit models that do not account for Sr cations on B-sites were ruled out. A clear Sr-Pb peak in Fourier transformed EXAFS data visually confirmed this structural model. The generation of temporary oxygen vacancies and the intricate defect chemistry induced by SNO-doping of PZT are crucial for the exceptional materials properties exhibited by PZT:SNO materials.
Date:
April 26, 2007
Creator:
Feltz, A.; Schmidt-Winkel, P.; Schossman, M.; Booth, C.H. & Albering, J.
Object Type:
Article
System:
The UNT Digital Library
Climate response to projected changes in short-lived species under an A1B scenario from 2000-2050 in the GISS climate model
We investigate the climate forcing from and response to projected changes in short-lived species and methane under the A1B scenario from 2000-2050 in the GISS climate model. We present a meta-analysis of new simulations of the full evolution of gas and aerosol species and other existing experiments with variations of the same model. The comparison highlights the importance of several physical processes in determining radiative forcing, especially the effect of climate change on stratosphere-troposphere exchange, heterogeneous sulfate-nitrate-dust chemistry, and changes in methane oxidation and natural emissions. However, the impact of these fairly uncertain physical effects is substantially less than the difference between alternative emission scenarios for all short-lived species. The net global mean annual average direct radiative forcing from the short-lived species is .02 W/m{sup 2} or less in our projections, as substantial positive ozone forcing is largely offset by negative aerosol direct forcing. Since aerosol reductions also lead to a reduced indirect effect, the global mean surface temperature warms by {approx}0.07 C by 2030 and {approx}0.13 C by 2050, adding 19% and 17%, respectively, to the warming induced by long-lived greenhouse gases. Regional direct forcings are large, up to 3.8 W/m{sup 2}. The ensemble-mean climate response shows little regional …
Date:
March 26, 2007
Creator:
Menon, Surabi; Shindell, Drew T.; Faluvegi, Greg; Bauer, Susanne E.; Koch, Dorothy M.; Unger, Nadine et al.
Object Type:
Article
System:
The UNT Digital Library