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Transition to Turbulence and Effect of Initial Conditions on 3D Compressible Mixing in Planar Blast-wave-driven Systems (open access)

Transition to Turbulence and Effect of Initial Conditions on 3D Compressible Mixing in Planar Blast-wave-driven Systems

Perturbations on an interface driven by a strong blast wave grow in time due to a combination of Rayleigh-Taylor, Richtmyer-Meshkov, and decompression effects. In this paper, results from three-dimensional numerical simulations of such a system under drive conditions to be attainable on the National Ignition Facility [E. M. Campbell, Laser Part. Beams, 9(2), 209 (1991)] are presented. Using the multi-physics, adaptive mesh refinement, higher order Godunov Eulerian hydrocode, Raptor [L. H. Howell and J.A. Greenough, J. Comp. Phys. 184, 53 (2003)], the late nonlinear instability evolution, including transition to turbulence, is considered for various multimode perturbation spectra. The 3D post-transition state differs from the 2D result, but the process of transition proceeds similarly in both 2D and 3D. The turbulent mixing transition results in a reduction in the growth rate of the mixing layer relative to its pre-transition value and, in the case of the bubble front, relative to the 2D result. The post-transition spike front velocity is approximately the same in 2D and 3D. Implications for hydrodynamic mixing in core-collapse supernova are discussed.
Date: November 8, 2004
Creator: Miles, A R; Edwards, M J & Greenough, J A
Object Type: Article
System: The UNT Digital Library
Saudi Arabia: Current Issues and U.S. Relations (open access)

Saudi Arabia: Current Issues and U.S. Relations

This report includes information regarding current issues in Saudi Arabia, background to Saudi-U.S. relations, and congressional interest in Saudi Arabia
Date: November 8, 2004
Creator: Prados, Alfred B.
Object Type: Report
System: The UNT Digital Library
Appropriations for FY2005: Department of Homeland Security (open access)

Appropriations for FY2005: Department of Homeland Security

This report describes the FY2005 appropriations for the Department of Homeland Security (DHS). The report includes tables that compare the FY2004 appropriations for the programs and activities of DHS, the President's FY2005 request, the congressional response to the request, and the amounts enacted for FY2005.
Date: November 8, 2004
Creator: Lake, Jennifer E. & Nuñez-Neto, Blas
Object Type: Report
System: The UNT Digital Library
Probability Density Function for Waves Propagating in a Straight PEC Rough Wall Tunnel (open access)

Probability Density Function for Waves Propagating in a Straight PEC Rough Wall Tunnel

The probability density function for wave propagating in a straight perfect electrical conductor (PEC) rough wall tunnel is deduced from the mathematical models of the random electromagnetic fields. The field propagating in caves or tunnels is a complex-valued Gaussian random processing by the Central Limit Theorem. The probability density function for single modal field amplitude in such structure is Ricean. Since both expected value and standard deviation of this field depend only on radial position, the probability density function, which gives what is the power distribution, is a radially dependent function. The radio channel places fundamental limitations on the performance of wireless communication systems in tunnels and caves. The transmission path between the transmitter and receiver can vary from a simple direct line of sight to one that is severely obstructed by rough walls and corners. Unlike wired channels that are stationary and predictable, radio channels can be extremely random and difficult to analyze. In fact, modeling the radio channel has historically been one of the more challenging parts of any radio system design; this is often done using statistical methods. In this contribution, we present the most important statistic property, the field probability density function, of wave propagating in …
Date: November 8, 2004
Creator: Pao, H
Object Type: Article
System: The UNT Digital Library
Child Welfare: Implementation of the Adoption and Safe Families Act (open access)

Child Welfare: Implementation of the Adoption and Safe Families Act

This report provides an overview of the implementation of adoption and safe families act on child welfare.
Date: November 8, 2004
Creator: Spar, Karen & Shuman, Matthew
Object Type: Report
System: The UNT Digital Library
New Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells Quarterly Report: July-September 2004 (open access)

New Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells Quarterly Report: July-September 2004

None
Date: November 8, 2004
Creator: Jacobson, Allan J.
Object Type: Report
System: The UNT Digital Library
BIOTIC INTEGRITY OF STREAMS IN THE SAVANNAH RIVER SITE INTEGRATOR OPERABLE UNITS, 1996 TO 2003 (open access)

BIOTIC INTEGRITY OF STREAMS IN THE SAVANNAH RIVER SITE INTEGRATOR OPERABLE UNITS, 1996 TO 2003

The Savannah River Site (SRS) has been divided into six Integrator Operable Units (IOUs) that correspond to the watersheds of the five major streams on the SRS (Upper Three Runs, Fourmile Branch, Pen Branch, Steel Creek, and Lower Three Runs) and the portions of the Savannah River and Savannah River Swamp associated with the SRS. The streams are the primary integrators within each IOU because they potentially receive, through surface or subsurface drainage, soluble contaminants from all waste sites within their watersheds. If these contaminants reach biologically significant levels, they would be expected to effect the numbers, types, and health of stream organisms. In this study, biological sampling was conducted within each IOU as a measure of the cumulative ecological effects of the waste sites within the IOUs. The use of information from biological sampling to assess environmental quality is often termed bioassessment. The IOU bioassessment program included 38 sites in SRS streams and nine sites in the Savannah River. Sampling was conducted in 1996 to 1998, 2000, and 2003. Four bioassessment methods were used to evaluate ecological conditions in the IOU streams: the Index of Biotic Integrity, the Fish Health Assessment Index, measurement of fish tissue contaminant levels, and …
Date: November 8, 2004
Creator: Paller, M & Susan Dyer, S
Object Type: Report
System: The UNT Digital Library
SATURATED ZONE IN-SITU TESTING (open access)

SATURATED ZONE IN-SITU TESTING

The purpose of this scientific analysis is to document the results and interpretations of field experiments that test and validate conceptual flow and radionuclide transport models in the saturated zone (SZ) near Yucca Mountain, Nevada. The test interpretations provide estimates of flow and transport parameters used in the development of parameter distributions for total system performance assessment (TSPA) calculations. These parameter distributions are documented in ''Site-Scale Saturated Zone Flow Model (BSC 2004 [DIRS 170037]), Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]), Saturated Zone Colloid Transport (BSC 2004 [DIRS 170006]), and ''Saturated Zone Flow and Transport Model Abstraction'' (BSC 2004 [DIRS 170042]). Specifically, this scientific analysis contributes the following to the assessment of the capability of the SZ to serve as part of a natural barrier for waste isolation for the Yucca Mountain repository system: (1) The bases for selection of conceptual flow and transport models in the saturated volcanics and the saturated alluvium located near Yucca Mountain. (2) Results and interpretations of hydraulic and tracer tests conducted in saturated fractured volcanics at the C-wells complex near Yucca Mountain. The test interpretations include estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion …
Date: November 8, 2004
Creator: REIMUS, P.W.
Object Type: Report
System: The UNT Digital Library
TOP500 Supercomputers for November 2004 (open access)

TOP500 Supercomputers for November 2004

24th Edition of TOP500 List of World's Fastest Supercomputers Released: DOE/IBM BlueGene/L and NASA/SGI's Columbia gain Top Positions MANNHEIM, Germany; KNOXVILLE, Tenn.; BERKELEY, Calif. In what has become a closely watched event in the world of high-performance computing, the 24th edition of the TOP500 list of the worlds fastest supercomputers was released today (November 8, 2004) at the SC2004 Conference in Pittsburgh, Pa.
Date: November 8, 2004
Creator: Strohmaier, Erich; Meuer, Hans W.; Dongarra, Jack & Simon, Horst D.
Object Type: Report
System: The UNT Digital Library
Biosphere Model Report (open access)

Biosphere Model Report

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), TSPA-LA. The ERMYN provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs) (Section 6.2), the reference biosphere (Section 6.1.1), the human receptor (Section 6.1.2), and approximations (Sections 6.3.1.4 and 6.3.2.4); (3) Building a mathematical model using the biosphere conceptual model (Section 6.3) and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an …
Date: November 8, 2004
Creator: Wu, D. W. & Smith, A. J.
Object Type: Report
System: The UNT Digital Library
Features, Events, and Processes: Disruptive Events (open access)

Features, Events, and Processes: Disruptive Events

The purpose of this analysis report is to evaluate and document the inclusion or exclusion of the disruptive events features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment for license application (TSPA-LA). A screening decision, either ''Included'' or ''Excluded,'' is given for each FEP, along with the technical basis for screening decisions. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.114 (d), (e), and (f) [DIRS 156605]. The FEPs addressed in this report deal with both seismic and igneous disruptive events, such as fault displacements through the repository and an igneous intrusion into the repository. For included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded). Previous versions of this report were developed to support the total system performance assessments (TSPA) for various prior repository designs. This revision addresses the repository design for the license application (LA).
Date: November 8, 2004
Creator: Sanchez, P.
Object Type: Report
System: The UNT Digital Library
CO2 Capture by Absorption With Potassium Carbonate Quarterly Report (open access)

CO2 Capture by Absorption With Potassium Carbonate Quarterly Report

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. The stripper model with Aspen Custom Modeler and careful optimization of solvent rate suggests that 7 m MEA and 5 m K+/2.5 m PZ will be practically equivalent in energy requirement and optimum solution capacity. The multipressure stripper reduces energy consumption by 15% with a maximum pressure of 5 atm. The use of vanadium as a corrosion inhibitor will carry little risk of long-term environmental or health effects liability, but the disposal of solvent with vanadium will be subject to regulation, probably as a hazardous waste. Analysis of the pilot plant data from Campaign 1 has given values of the mass transfer coefficient consistent with the rate data from the wetted wall column. With a rich end pinch, 30% MEA should provide a capacity of 1.3-1.4 mole CO{sub 2}/kg solvent.
Date: November 8, 2004
Creator: Rochelle, Gary T.; Chen, Eric; Lu, Jennifer; Oyenekan, Babatunde & Dugas, Ross
Object Type: Report
System: The UNT Digital Library
Analysis of copper-rich precipitates in silicon: chemical state,gettering, and impact on multicrystalline silicon solar cellmaterial (open access)

Analysis of copper-rich precipitates in silicon: chemical state,gettering, and impact on multicrystalline silicon solar cellmaterial

In this study, synchrotron-based x-ray absorption microspectroscopy (mu-XAS) is applied to identifying the chemical states of copper-rich clusters within a variety of silicon materials, including as-grown cast multicrystalline silicon solar cell material with high oxygen concentration and other silicon materials with varying degrees of oxygen concentration and copper contamination pathways. In all samples, copper silicide (Cu3Si) is the only phase of copper identified. It is noted from thermodynamic considerations that unlike certain metal species, copper tends to form a silicide and not an oxidized compound because of the strong silicon-oxygen bonding energy; consequently the likelihood of encountering an oxidized copper particle in silicon is small, in agreement with experimental data. In light of these results, the effectiveness of aluminum gettering for the removal of copper from bulk silicon is quantified via x-ray fluorescence microscopy (mu-XRF),and a segregation coefficient is determined from experimental data to beat least (1-2)'103. Additionally, mu-XAS data directly demonstrates that the segregation mechanism of Cu in Al is the higher solubility of Cu in the liquid phase. In light of these results, possible limitations for the complete removal of Cu from bulk mc-Si are discussed.
Date: November 8, 2004
Creator: Buonassisi, Tonio; Marcus, Matthew A.; Istratov, Andrei A.; Heuer, Matthias; Ciszek, Theodore F.; Lai, Barry et al.
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 83, No. 340, Ed. 1 Monday, November 8, 2004 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 83, No. 340, Ed. 1 Monday, November 8, 2004

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: November 8, 2004
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
The Gas to Liquids Industry and Natural Gas Markets (open access)

The Gas to Liquids Industry and Natural Gas Markets

This report provides and analyzes basic information concerning the gas to liquids industry (GTL) industry to inform debate on broad energy legislation, as well as more specific natural gas legislation on supply issues including an Alaskan natural gas pipeline as well as LNG facility development.
Date: November 8, 2004
Creator: Pirog, Robert
Object Type: Report
System: The UNT Digital Library
Precision damage tests of multilayer dielectric gratings for high-energy petawatt lasers (open access)

Precision damage tests of multilayer dielectric gratings for high-energy petawatt lasers

The next generation of high-energy petawatt (HEPW)-class lasers will utilize multilayer dielectric diffraction gratings for pulse compression due to their high efficiency and high damage threshold for picosecond pulses. We have developed a short-pulse damage test station for accurate determination of the damage threshold of the optics used on future HEPW lasers. The design and performance of the damage test laser source, based on a highly stable, high-beam-quality optical parametric chirped-pulse amplifier, is presented. Our short-pulse damage measurement methodology and results are discussed. The damage initiation is attributed to multiphoton-induced avalanche ionization, strongly dependent on the electric field enhancement in the grating groove structure and surface defects. Measurement results of the dependence of damage threshold on the pulse width, angular dependence of damage threshold of diffraction gratings, and an investigation of short-pulse conditioning effects are presented. We report record >4 J/cm{sup 2} right section surface damage thresholds obtained on multilayer dielectric diffraction gratings at 76.5 incidence angles for 10-ps pulses.
Date: November 8, 2004
Creator: Jovanovic, I; Brown, C G; Stuart, B C; Molander, W; Nielsen, N; Wattellier, B et al.
Object Type: Article
System: The UNT Digital Library
Recent Applications of SPME in Directed Stockpile Work (FY04) (open access)

Recent Applications of SPME in Directed Stockpile Work (FY04)

Solid Phase Microextraction (SPME) has been used to sample nonnuclear materials for analysis by gas chromatography-mass spectrometry (GC/MS). This report summarizes progress in the areas of individual materials' outgassing signatures, microcompatibility tests and analysis of polar analytes.
Date: November 8, 2004
Creator: Alviso, C; Harvey, C & Vance, A
Object Type: Report
System: The UNT Digital Library
Glove Box Procedure for Dissolving of Be from Pu/Be Metal Mixtures using the NaOH Process (open access)

Glove Box Procedure for Dissolving of Be from Pu/Be Metal Mixtures using the NaOH Process

None
Date: November 8, 2004
Creator: Krikorian, O H & Bajao, Jr, F G
Object Type: Report
System: The UNT Digital Library
Review of Progress in Fast Ignition (open access)

Review of Progress in Fast Ignition

Marshall Rosenbluth's extensive contributions included seminal analysis of the inertial fusion program. Over the last decade he avidly followed the efforts of many scientists around the world who have studied Fast Ignition, an alternate form of inertial fusion. In this scheme, the fuel is first compressed by a long pulse driver and then ignited by the short pulse laser. Due to technological advances, external energy sources (such as short pulse lasers) can focus intensity equivalent to that produced by the hydrodynamic stagnation of conventional inertial fusion capsules. This review will discuss the ignition requirements and gain curves starting from simple models and then describing how these are modified, as more detailed physics understanding is included. The critical design issues revolve around two questions: How can the compressed fuel be efficiently assembled? And how can power from the driver be delivered to the ignition region? Schemes to shorten the distance between the critical surface and the ignition region will de discussed. The status of the project is compared with our requirements for success. Future research directions will be outlined.
Date: November 8, 2004
Creator: Tabak, M.; Town, R.; Lasinski, B.; Snavely, R.; Clark, D.; Wilks, S. et al.
Object Type: Article
System: The UNT Digital Library
Comparison of the House and Senate ETI/Business Investment Bills (H.R. 4520 and S. 1637, 108th Congress) (open access)

Comparison of the House and Senate ETI/Business Investment Bills (H.R. 4520 and S. 1637, 108th Congress)

In fall 2004, Congress considered legislation that addresses both domestic and international business investment and the long-simmering controversy between the United States and the European Union over the U.S. tax code's extraterritorial income tax benefit for exporting. This report contains information on agreements between the U.S. and the European Union, impact on tax revenues, extraterritorial income benefit for exports, tax benefits restricted to domestic production, and more.
Date: November 8, 2004
Creator: Brumbaugh, David L.
Object Type: Report
System: The UNT Digital Library
Federal Management and Protection of Paleontological (Fossil) Resources Located on Federal Lands: Current Status and Legal Issues (open access)

Federal Management and Protection of Paleontological (Fossil) Resources Located on Federal Lands: Current Status and Legal Issues

None
Date: November 8, 2004
Creator: Weimer, Douglas Reid
Object Type: Report
System: The UNT Digital Library
Oral History Interview with John Lee, November 8, 2004 transcript

Oral History Interview with John Lee, November 8, 2004

The National Museum of the Pacific War presents an interview with John Lee. Lee entered the Army Air Forces in November, 1942 as an aviation cadet trainee. After washing out of pilot training, he volunteered to go to gunnery school. After gunnery training, Lee was assigned as a waist gunner on a B-24 crew and went overseas in January, 1945. He arrived in England and was assigned to the 409th Bomb Squadron, 93rd Bomb Group. Lee flew on 19 bombing missions between January and April, 1945. His crew returned to the US in May. Lee stayed in the Reserves until 1982.
Date: November 8, 2004
Creator: Lee, John L.
Object Type: Sound
System: The Portal to Texas History
Effects of backlight structure on absorption experiments (open access)

Effects of backlight structure on absorption experiments

The impact of spectral details in the backlight of absorption spectroscopy experiments is considered. It is shown that experimentally unresolved structure in the backlight spectrum can introduce significant errors in the inferred transmission. Furthermore, it is shown that a valuable experimental procedure previously used to test the accuracy of the data fails to reveal these errors.
Date: November 8, 2004
Creator: Iglesias, C A
Object Type: Article
System: The UNT Digital Library
IN SITU FIELD TESTING OF PROCESSES (open access)

IN SITU FIELD TESTING OF PROCESSES

The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes REV 02. The scientific analysis of data for inputs to model calibration and validation as documented in REV 02 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in …
Date: November 8, 2004
Creator: YANG, J.S.Y.
Object Type: Report
System: The UNT Digital Library