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Secondary School Completion and Dropouts in Texas Public Schools: 2000-2001, Supplemental District Data (open access)

Secondary School Completion and Dropouts in Texas Public Schools: 2000-2001, Supplemental District Data

Supplementary compilation summarizing data regarding graduates and dropouts in Texas public secondary schools broken down by districts (alphabetically) and by various demographic characteristics.
Date: August 2002
Creator: Texas Education Agency. Division of Research and Evaluation.
System: The Portal to Texas History
Secondary School Completion and Dropouts in Texas Public Schools: 2000-2001, District and Campus Listings (open access)

Secondary School Completion and Dropouts in Texas Public Schools: 2000-2001, District and Campus Listings

Supplementary compilation summarizing data regarding graduates and dropouts in Texas public secondary schools broken down by districts (alphabetically) and by various demographic characteristics.
Date: August 2002
Creator: Texas Education Agency. Division of Research and Evaluation.
System: The Portal to Texas History
Secondary School Completion and Dropouts in Texas Public Schools: 2000-2001, County Listings (open access)

Secondary School Completion and Dropouts in Texas Public Schools: 2000-2001, County Listings

Supplementary compilation summarizing data regarding graduates and dropouts in Texas public secondary schools broken down by counties (alphabetically) and by various demographic characteristics.
Date: August 2002
Creator: Texas Education Agency. Division of Accountability Research.
System: The Portal to Texas History
Cardiovascular Disease in Texas: A Risk Factor Report 1999 Survey Data (open access)

Cardiovascular Disease in Texas: A Risk Factor Report 1999 Survey Data

Report that describes cardiovascular disease, the initial causes, and the risk factors involved.
Date: August 2002
Creator: Li, Weihua; Blanton, Jimmy; Kropp, Richard & Huang, Philip P.
System: The Portal to Texas History
Reconciliation Report (open access)

Reconciliation Report

Reconciliation report with an ending account balance of $1,622.07 reconciled for the period ending on August 19, 2002.
Date: August 19, 2002
Creator: unknown
System: The UNT Digital Library
A SPICE Model and Electrostatic Field Analysis of the MOS Turn-Off Thyristor (open access)

A SPICE Model and Electrostatic Field Analysis of the MOS Turn-Off Thyristor

This paper presents a circuit model and an electrostatic field analysis with an approximate model of the SDM170HK MOS turn-off thyristor (MTO) fabricated by Silicon Power Corporation. The circuit model consists of five cells, each containing two bipolar junction transistors and three resistors. The turn-off feature of the MTO was simulated by inserting an array of 21 Fairchild FDS6670A MOSFET importable sub-circuit components between the cathode and the turn-on gate. The model was then used to create a four-terminal sub-circuit component representing the MTO that can be readily imported into computer-aided circuit design programs such as PSPICE and Micro-Cap. The generated static I-V characteristics and simulated switching waveforms are shown. The electrostatic field analysis was done for the maximum operating voltage of 4.5 kV using the Ansoft Maxwell 3D field simulator. Electrostatic field magnitudes that exceed the nominal air breakdown threshold of 30 kV/cm were observed surrounding the simulated turn-off gate wire, the turn-off gate ring contact, and the cathode ring contact. The resulting areas of high fields are a concern, as arc track marks have been found on the inner surface of the ceramic insulator near the internal gate connections of a failed device.
Date: August 5, 2002
Creator: Kelly, D. Q.; Mayhall, D. J.; Wilson, M. J. & Lahowe, D. A.
System: The UNT Digital Library
EVALUATION OF THE MIGRATION POTENTIAL FOR 60Co AND 137Cs AT THE MAINE YANKEE SITE. (open access)

EVALUATION OF THE MIGRATION POTENTIAL FOR 60Co AND 137Cs AT THE MAINE YANKEE SITE.

The objective of this report is to discuss the degree of sorption and desorption of {sup 137}Cs and {sup 60}Co that may be associated with the granite bedrock and the ''popcorn'' cement drain system that underlie the Maine Yankee Containment Foundation. The purpose is to estimate how much retardation of these two radionuclides takes place in groundwater that flows in the near-field of the Containment Foundation, specifically with respect to contamination originating at the PAB Test Pit. Specific concerns revolve around the potential for the contamination originating near the PAB to create a radioactive dose to a hypothetical ''resident farmer'' using a well intercepting this water to exceed 4 millirems/yr.
Date: August 8, 2002
Creator: FUHRMANN,M. SULLIVAN,T.
System: The UNT Digital Library
April 2002 Working Group Meeting on Heavy Vehicle Aerodynamic Drag: Presentations and Summary of Comments and Conclusions (open access)

April 2002 Working Group Meeting on Heavy Vehicle Aerodynamic Drag: Presentations and Summary of Comments and Conclusions

A Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held at Lawrence Livermore National Laboratory on April 3 and 4, 2002. The purpose of the meeting was to present and discuss technical details on the experimental and computational work in progress and future project plans. Representatives from the Department of Energy (DOE) Office of Transportation Technology Office of Heavy Vehicle Technology (OHVT), Lawrence Livermore National Laboratory (LLNL), Sandia National Laboratories (SNL), NASA Ames Research Center, University of Southern California (USC), and California Institute of Technology (Caltech), Georgia Tech Research Institute (GTRI), and Argonne National Laboratory (ANL), Volvo Trucks, and Freightliner Trucks presented and participated in discussions. This report contains the technical presentations (viewgraphs) delivered at the Meeting, briefly summarizes the comments and conclusions, and outlines the future action items.
Date: August 22, 2002
Creator: Salari, K.; Dunn, T.; Ortega, J.; Yen-Nakafuji, D.; Browand, F.; Arcas, D. et al.
System: The UNT Digital Library
Pressure Loads by Gas in an Enclosed Chamber in DYNA3D (open access)

Pressure Loads by Gas in an Enclosed Chamber in DYNA3D

New algorithms that efficiently calculate the volume of a closed chamber are presented in this paper. The current pressure in the enclosed chamber can then be computed, based on the user-specified gas law, from the updated volume and the initial volume and pressure of the chamber. This pressure load function is very useful in modeling common features, such as air pocket, airbag, piston, and gun barrel, in structural analyses.
Date: August 8, 2002
Creator: Lin, J & Badders, D C
System: The UNT Digital Library
Matrix Diffusion and Colloid-Facilitated Transport in Fractured Rocks: Model and Parameter Validation (open access)

Matrix Diffusion and Colloid-Facilitated Transport in Fractured Rocks: Model and Parameter Validation

In this report, we review the results of Reimus et al. (2000a; 2000b) regarding matrix diffusion and colloid-facilitated transport in fractured rock and evaluate the implications of these results on modeling fracture flow at the Nevada Test Site (NTS). In particular, we examine these data in the context of the recent Cheshire hydrologic source term (HST) model results (Pawloski et al., 2001). This report is divided into several sections. In the first, we evaluate the effective diffusion coefficient (D{sub e}) data reported in Reimus et al. (2000a) for conservative tracer species ({sup 3}H, {sup 14}C, and {sup 99}Tc) and fit a simple effective diffusion model to these data. In the second, we use the fitted effective diffusion model, in conjunction with a surface complexation model, to simulate plutonium-colloid transport and compare model results to data reported in Reimus et al. (2000b). In the third, we evaluate the implications of these data with regards to radionuclide transport through fractures at the field scale and, in particular, with regards to the Cheshire HST model (Pawloski et al., 2001). Finally, we make recommendations regarding future radionuclide transport modeling efforts at the NTS.
Date: August 2, 2002
Creator: Zavarin, M
System: The UNT Digital Library
Metal Oxides in the Environment (open access)

Metal Oxides in the Environment

Oxides are ubiquitous in much of environmental chemistry. Silica and related glasses are potential vehicles by which radioactive elements may be sequestered and stored. The migration of toxic waste in ground water is largely influenced by interactions at the liquid-solid interface, with several metal oxides making up the bulk of soil. In addition, metal oxides with Bronsted acid or Lewis base functionality are potential replacements for many traditional liquid catalysis that are hazardous to work with and difficult to dispose. In this proposal, we targeted two such areas of oxide chemistry. The long-term behavior of silicate materials slated for use in the entombment of high-level waste (HLW), and the use of solid acid metal oxides as replacements for toxic sulfuric and hydrofluoric acid used in industry (referred to as Green Chemistry). Thus, this project encompassed technology that can be used to both remediate and prevent pollution. These oxide systems were studied using density functional theory (DFT). The comparatively large size and complexity of the systems that will bweree studied made use of high-accuracy electronic structure studies intractable on conventional computers. The 512 node parallel processor housed in the Molecular Science Computing Facility (MSCF) provided the required capability.
Date: August 30, 2002
Creator: Jonsson, Hannes; Corrales, L. Rene; Gabriel, Peggy; Haw, James F.; Henkelman, Graeme A.; Neurock, Matthew et al.
System: The UNT Digital Library
Report on Radiation Damage Effects in a Titanium Target Under Photon Irradiation (open access)

Report on Radiation Damage Effects in a Titanium Target Under Photon Irradiation

Following the same approach as with the W-Re targets [l], we have calculated the damage induced by photon irradiation (22.1 MeV average energy) in titanium targets. Stefan Roesler calculated, using FLUKA [2] the spallation products, neutrons and fission products from the interaction of the photons with the titanium target. Using these initial values of energies and positions, we calculated the number of defects produced per incoming photon. It should be noted that the threshold displacement energy for defect production of Titanium as measured experimentally is between 21 and 30 eV [3]. We used a value of 25eV. This is a much lower value than for the case of W-alloys (90 eV) which implies a larger defect production for the same deposited energy in the case of Titanium. The number of defects for different neutron energies was calculated using SPECTER [4] Figure 1(a) shows the number of defects as a function of energy for the case of Ti as compared to W, in Figure 1(b). The number of defects is much larger in the Ti case due to the low threshold displacement energy as explained.
Date: August 30, 2002
Creator: Caturla, M J; Roesler, S; Bharadwaj, V K; Schultz, D C; Sheppard, J C; Marian, J et al.
System: The UNT Digital Library
Natural Gas Storage in Basalt Aquifers of the Columbia Basin, Pacific Northwest USA: A Guide to Site Characterization (open access)

Natural Gas Storage in Basalt Aquifers of the Columbia Basin, Pacific Northwest USA: A Guide to Site Characterization

This report provides the technical background and a guide to characterizing a site for storing natural gas in the Columbia River Basalt
Date: August 8, 2002
Creator: Reidel, Steve P.; Spane, Frank A. & Johnson, Vernon G.
System: The UNT Digital Library
Project Plan for Vertical Lift Machine (open access)

Project Plan for Vertical Lift Machine

This document describes the Project Plan for the development and manufacture of a Vertical Lift Machine. It is assumed by this project plan that the Vertical Lift Machine will be developed, designed, manufactured, and tested by a qualified vendor. LLNL will retain review and approval authority for each step given in this project plan. The Vertical Lift Machine is a single linear axis positioning device capable of lifting objects vertically at controlled rates and positioning them repeatedly at predetermined heights, in relation to other objects suspended from above, for high neutron multiplication experiments. Operation of the machine during the experiments is done remotely. The lift mechanism shall accommodate various platforms (tables) that support the objects to be raised. A frame will support additional subassemblies from above such that the lower subassembly can be raised close to and/or interface with those above. The structure must be stiff and motion of the table linear such that radial alignment is maintained (e.g. concentricity). The safe position for the Vertical Lift Machine is the lift mechanism fully retracted with the subassemblies fully separated. The machine shall reside in this position when not in use. It must return to this safe condition from any position …
Date: August 5, 2002
Creator: Ellsworth, G F
System: The UNT Digital Library
Lawrence Livermore National Laboratory Summer Employment Summary (open access)

Lawrence Livermore National Laboratory Summer Employment Summary

This document will serve as a summary of my work activities as a summer employee for the Lawrence Livermore National Laboratory (LLNL). The intent of this document is to provide an overview of the National Ignition Facility (NIF) project, to explain the role of the department that I am working for, and to discuss my specific assigned tasks and their impact on the NIF project as a whole.
Date: August 6, 2002
Creator: Wilson, A J
System: The UNT Digital Library
Chemistry and Materials Science Directorate 2002 Postdoctoral Symposium (open access)

Chemistry and Materials Science Directorate 2002 Postdoctoral Symposium

The understanding of the physical mechanisms by which important biological inhibitors control the nucleation, growth, aggregation, and phase transformation of calcium oxalate crystals at fundamental level is of importance not only to the advances in biomineralization but also to the development of stone disease therapy. Of the three phases of calcium oxalate crystalline, calcium oxalate monohydrate (COM) and dehydrate (COD) are found in the majority of stones formed in the urinary system. Only COM, a major inorganic component of kidney stones, produces adverse physiological effects to human, however. Although a great deal of research has been carried out on the modulation of nucleation, growth, aggregation, and phase transformation of calcium oxalates by biological molecules, the basic mechanism has not yet been determined due to inherent limitations of those techniques that have been utilized The invention of atomic force microscopy (AFM) has opened a new avenue for the study of the crystal growth in general. One can now probe the growth kinetics and dynamics, and morphology of crystal surfaces down to molecular levels as a typical AFM has a lateral resolution of nanometers. In this study, in situ AFM was used to monitor the COM surface under controlled growth conditions. The …
Date: August 14, 2002
Creator: Wirth, B D
System: The UNT Digital Library
Chemical Fate of Contaminants in the Environment: Chlorinated Hydrocarbons in the Groundwater (open access)

Chemical Fate of Contaminants in the Environment: Chlorinated Hydrocarbons in the Groundwater

Chlorinated hydrocarbons (CHCs) are the most common contaminant found at hazardous waste sites and are the most prevalent contaminants on (Department of Energy) DOE weapons production sites. Many of the chlorinated hydrocarbons are either known or suspected carcinogens and thus pose health risks to the public and/or site workers. Chlorinated hydrocarbons, unlike simple hydrocarbons, are resistant to biodegradation, but can degrade by abiotic processes such as hydrolysis, nucleophilic substitution, and dehydrochlorination. Unfortunately, few studies of the reactions of chlorinated hydrocarbons have been reported in the literature, and disagreement still exist about the mechanisms and rates of many of the key reactions.
Date: August 1, 2002
Creator: Garrett, Bruce C.; Arcia, Edgar E.; Borisov, Yurii A.; Cramer, Christopher; Dunning, Thom H.; Dupuis, Michel et al.
System: The UNT Digital Library
Effects of Globally Waste-Disturbing Activities on Gas Generation, Retention, and Release in Hanford Waste Tanks (open access)

Effects of Globally Waste-Disturbing Activities on Gas Generation, Retention, and Release in Hanford Waste Tanks

Various operations are authorized in Hanford single-shell and double-shell tanks that disturb all or a large fraction of the waste. These globally waste-disturbing activities have the potential to release a significant volume of retained gas. Analyses are presented for expected gas release mechanisms and the potential release rates and volumes resulting from these activities. Recommendations for gas monitoring and assessment of the potential for changes in tank classification and steady-state flammability are also given.
Date: August 30, 2002
Creator: Stewart, Charles W. (BATTELLE (PACIFIC NW LAB)); Huckaby, James L. (BATTELLE (PACIFIC NW LAB)) & Meyer, Perry A. (BATTELLE (PACIFIC NW LAB))
System: The UNT Digital Library
New Crystalline Materials for Nonlinear Frequency Conversion, Electro-Optic Modulation, and Mid-Infrared Gain Media (open access)

New Crystalline Materials for Nonlinear Frequency Conversion, Electro-Optic Modulation, and Mid-Infrared Gain Media

New crystalline materials were investigated for applications in frequency conversion of near-infrared wavelengths and as gain media for tunable mid-infrared solid-state lasers. GaCa{sub 4}O(BO{sub 3}){sub 3} (GdCOB), YCa{sub 4}O(BO{sub 3}){sub 3} (YCOB), LaCa{sub 4}O(BO{sub 3}){sub 3} (LaCOB), and Gd{sub 0.275}Y{sub 0.725}Ca{sub 4}O(BO{sub 3}){sub 3} were characterized for frequency conversion of 1 {micro}m lasers. For type I doubling at 1064 nm, LaCOB, GdCOB, and YCOB were found to have effective coupling coefficients (d{sub eff}) of 0.52 {+-} 0.05, 0.78 {+-} 0.06, and 1.12 {+-} 0.07 pm/V, respectively. LaCOB was measured to have angular and thermal sensitivities of 1224 {+-} 184 (cm-rad){sup -1} and < 0.10 (cm-{sup o}C){sup -1}, respectively. The effective coupling coefficient for type II noncritically phasematched (NCPM) doubling at 1064 nm in Gd{sub 0.275}Y{sub 0.725}Ca{sub 4}O(BO{sub 3}){sub 3} was measured to be 0.37 {+-} 0.04 pm/V. We predict LaCOB to have a type I NCPM fundamental wavelength of 1042 {+-} 1.5 nm. Due to its low angular and thermal sensitivities for doubling near 1047 nm, LaCOB has potential for frequency doubling of high-average power Nd:LiYF{sub 4} and Yb:Sr{sub 5}(P0{sub 4}){sub 3}F lasers. LaCOB, GdCOB, and YCOB were also investigated for optical parametric oscillator applications and we determined that they …
Date: August 9, 2002
Creator: Adams, J.
System: The UNT Digital Library
Mechanistic Process Modeling for Subsurface Remediation (open access)

Mechanistic Process Modeling for Subsurface Remediation

The goal of this project was to develop the first generation of models that fully address the coupling of dominant processes controlling the behavior of fluid, chemical and biological components in the subsurface. The large memory and computational performance of multiprocessor computing architectures would be exploited to provide modeling capabilities with unprecedented process detail and resolution to assess new scientific hypotheses, assist with experimental design, and to evaluate environmental technologies and remediation design. Moreover, the proposed capability developments would advance the scientific agenda for the subsurface through the realized advances in complex multiple-phase reaction modeling.
Date: August 30, 2002
Creator: Yabusaki, Steven B.; Bryant, Steven L.; Chen, Shi-Yi; Fann, George I.; Flach, Gregory P.; Gray, William G. et al.
System: The UNT Digital Library
A Computational Approach to Understanding Oxidant Chemistry and Aerosol Formation in the Troposphere (open access)

A Computational Approach to Understanding Oxidant Chemistry and Aerosol Formation in the Troposphere

Ozone production and aerosol formation in the troposphere are recognized as two major effects of energy-related air pollutants. Tropospheric ozone is of concern primarily because of its impact on health. Ozone levels are controlled by NOx and by volatile organic compounds (VOCs) in the lower troposphere. The VOCs can either be from natural emissions from such sources as vegetation and phytoplankton or from anthropogenic sources such as automobiles and oil-fueled power production plants. It is of critical importance to the Department of Energy (DOE) in developing national energy use policies to understand the role of VOCs in determining air quality and how VOC emission or NOx emission control strategies should be designed.
Date: August 2002
Creator: Garrett, Bruce C.; Bianco, Roberto; Dang, Liem X.; Dixon, David A.; Dupuis, Michel; Francisco, Joseph et al.
System: The UNT Digital Library
12th Workshop on Crystalline Silicon Solar Cell Materials and Processes: Extended Abstracts and Papers, August 11-14, 2002, Breckenridge, Colorado (open access)

12th Workshop on Crystalline Silicon Solar Cell Materials and Processes: Extended Abstracts and Papers, August 11-14, 2002, Breckenridge, Colorado

The 12th Workshop will provide a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. Discussions will include various aspects of impurities and defects in silicon-their properties, the dynamics during processing, and their application for developing low-cost processes for manufacturing high-efficiency silicon solar cells. The workshop will emphasize some of the promising new technologies in Si solar cell fabrication that can lower PV energy costs and meet the production demands of the future. It will also provide an excellent opportunity for researchers, in private industry and at universities, to prioritize mutual needs for future collaborative research. Sessions and panel discussions will review recent advances in crystal growth, new cell structures, new processes and process characterization techniques, and manufacturing approaches suitable for future manufacturing demands . Some presentations will address recent technologies in the microelectronics field that may have a direct bearing on PV. The three-day workshop will consist of presentations by invited speakers, followed by discussion sessions. In addition, there will be two poster sessions presenting the latest research and development results.
Date: August 1, 2002
Creator: Sopori, B. L.
System: The UNT Digital Library
Computational Chemistry for Nuclear Waste Characterization and Processing: Relativistic Quantum Chemistry of Actinides (open access)

Computational Chemistry for Nuclear Waste Characterization and Processing: Relativistic Quantum Chemistry of Actinides

In the course of the 3 years we have conducted calculations on molecular structures containing actinides, lanthanides, and other heavy elements. Our calculations were done at the relativistically-correct, all-electron, 4-component calculations (DHF, MP2, and CCSD(T)), using density functional theory (DFT) with relativistic effective core potentials (RECPs), and various other methodologies. We studied the ground- and excited state structures, energetics, vibrational frequencies, and NMR, excitation and ionization spectra. In addition a considerable amount of codes and methodologies have been developed during the GC3 period, enabling us to do the extensive research described in this final report, and providing researchers worldwide with new computational chemistry tools. In this section we will give a brief overview of our activities and accomplishments, grouped by each research institution. A more extensive overview can be found in the appendices containing the full yearly reports.
Date: August 2, 2002
Creator: Harrison, Robert J.; Bernholdt, David E.; Bursten, Bruce E.; De Jong, Wibe A.; Dixon, David A.; Dyall, Kenneth G. et al.
System: The UNT Digital Library
Inertial Fusion Energy Studies on an Earth Simulator-Class Computer (open access)

Inertial Fusion Energy Studies on an Earth Simulator-Class Computer

The U.S. is developing fusion energy based on inertial confinement of the burning fusion fuel, as a complement to the magnetic confinement approach. DOE's Inertial Fusion Energy (IFE) program within the Office of Fusion Energy Sciences (OFES) is coordinated with, and gains leverage from, the much larger Inertial Confinement Fusion program of the National Nuclear Security Administration (NNSA). Advanced plasma and particle beam simulations play a major role in the IFE effort, and the program is well poised to benefit from an Earth Simulator-class resource. Progress in all key physics areas of IFE, including heavy-ion ''drivers'' which impart the energy to the fusion fuel, the targets for both ion- and laser-driven approaches, and an advanced concept known as fast ignition, would be dramatically accelerated by an Earth Simulator-class resource.
Date: August 13, 2002
Creator: Friedman, A & Stephens, R
System: The UNT Digital Library