Analysis of Fabry-Perot Velocimeter Records (open access)

Analysis of Fabry-Perot Velocimeter Records

Program demonstration and user instructions are presented for FabryVB5. This computer program was created for use in analyzing Fabry-Perot interferometer records that detail the velocity time histories of fast moving surfaces. Graphical curves representing peak fringe positions and fiducial timing dots are extracted from a digitized film record or from a CCD digital image. An analysis is demonstrated on a sample velocimeter record along with some mathematical formula and routine operations. Routines used to analyze calibration records on streak camera distortions are illustrated in an appendix. This is a Microsoft Visual Basic{trademark} version for the PC.
Date: August 3, 2001
Creator: Avara, G.
Object Type: Report
System: The UNT Digital Library
Designers Workbench: Towards Real-Time Immersive Modeling (open access)

Designers Workbench: Towards Real-Time Immersive Modeling

This paper introduces the DesignersWorkbench, a semi-immersive virtual environment for two-handed modeling, sculpting and analysis tasks. The paper outlines the fundamental tools, design metaphors and hardware components required for an intuitive real-time modeling system. As companies focus on streamlining productivity to cope with global competition, the migration to computer-aided design (CAD), computer-aided manufacturing (CAM), and computer-aided engineering (CAE) systems has established a new backbone of modern industrial product development. However, traditionally a product design frequently originates from a clay model that, after digitization, forms the basis for the numerical description of CAD primitives. The DesignersWorkbench aims at closing this technology or ''digital gap'' experienced by design and CAD engineers by transforming the classical design paradigm into its filly integrated digital and virtual analog allowing collaborative development in a semi-immersive virtual environment. This project emphasizes two key components from the classical product design cycle: freeform modeling and analysis. In the freeform modeling stage, content creation in the form of two-handed sculpting of arbitrary objects using polygonal, volumetric or mathematically defined primitives is emphasized, whereas the analysis component provides the tools required for pre- and post-processing steps for finite element analysis tasks applied to the created models.
Date: October 3, 2001
Creator: Kuester, F; Duchaineau, M A; Hamann, B; Joy, K I & Ma, K L
Object Type: Article
System: The UNT Digital Library
Theoretical Model for the EM Effects Induced by High-Energy Photons (Gamma, X-ray) in Dielectric Materials and Electronic Systems (open access)

Theoretical Model for the EM Effects Induced by High-Energy Photons (Gamma, X-ray) in Dielectric Materials and Electronic Systems

During last twenty years, a number of models have been used to calculate the change of conductivity and dielectric strength in materials caused by the passage of high-energy photons, such as Gamma-rays and X-rays. In these models, the electromagnetic fields generated in the electronic system created by the high-energy photons have not been investigated. That is, the solution of Maxwell's equations has not been obtained for these kinds of problems. We constructed a theoretical model, described by a set of equations to solve such a problem. The model includes the equations that describe the physics of the recombination and generation of electron-hole pairs by the high-energy photons in the dielectric materials, the Compton electron generation rates, and Maxwell's equations. When a beam of gamma photons penetrates into a transmission line or cables, energetic electrons and holes (carriers) are created in the metals and dielectrics of the system by the Compton and photoelectric effects. These energetic electrons and holes in turn create many low-energy holes and electrons through the interaction of the high-energy electrons with the atoms in the solids. Since the density of the solids is very high, the mean free path of the high-energy electrons is very short. In …
Date: August 3, 2001
Creator: Yee, J H; Mayhall, D J & Bland, M F
Object Type: Report
System: The UNT Digital Library
Engineering Technology Reports, Volume 2: Technology Base FY00 (open access)

Engineering Technology Reports, Volume 2: Technology Base FY00

In FY-2000, Engineering at Lawrence Livermore National Laboratory faced significant pressures to meet critical project milestones, and immediate demands to facilitate the reassignment of employees as the National Ignition Facility (the 600-TW laser facility being designed and built at Livermore, and one of the largest R&D construction projects in the world) was in the process of re-baselining its plan while executing full-speed its technology development efforts. This drive for change occurred as an unprecedented level of management and program changes were occurring within LLNL. I am pleased to report that we met many key milestones and achieved numerous technological breakthroughs. This report summarizes our efforts to perform feasibility and reduce-to-practice studies, demonstrations, and/or techniques--as structured through our technology centers. Whether using computational engineering to predict how giant structures like suspension bridges will respond to massive earthquakes or devising a suitcase-sized microtool to detect chemical and biological agents used by terrorists, we have made solid technical progress. Five Centers focus and guide longer-term investments within Engineering, as well as impact all of LLNL. Each Center is responsible for the vitality and growth of the core technologies it represents. My goal is that each Center will be recognized on an international scale …
Date: October 3, 2001
Creator: Baron, A. L.; Langland, R. T. & Minichino, C.
Object Type: Report
System: The UNT Digital Library
The Novel Synthesis of Silicon and Germanium Nanocrystallites (open access)

The Novel Synthesis of Silicon and Germanium Nanocrystallites

Interest in the synthesis of semiconductor nanoparticles has been generated by their unusual optical and electronic properties arising from quantum confinement effects. We have synthesized silicon and germanium nanoclusters by reacting Zintl phase precursors with either silicon or germanium tetrachloride in various solvents. Strategies have been investigated to stabilize the surface, including reactions with RLi and MgBrR (R = alkyl). This synthetic method produces group IV nanocrystals with passivated surfaces. These nanoparticle emit over a very large range in the visible region. These particles have been characterized using HRTEM, FTIR, UV-Vis, solid state NMR, and fluorescence. The synthesis and characterization of these nanoclusters will be presented.
Date: April 3, 2001
Creator: Kauzlarich, S. M.; Liu, Q.; Yin, S. C.; Lee, W. H. & Taylor, B.
Object Type: Article
System: The UNT Digital Library
SWEEP - Save Water & Energy Education Program (open access)

SWEEP - Save Water & Energy Education Program

The objective of this study was to develop, monitor, analyze, and report on an integrated resource-conservation program highlighting efficient residential appliances and fixtures. The sites of study were 50 homes in two water-constrained communities located in Oregon. The program was designed to maximize water savings to these communities and to serve as a model for other communities seeking an integrated approach to energy and water resource efficiency. The program included the installation and in-place evaluation of energy- and water-efficient devices including the following: horizontal axis clothes washers (and the matching clothes dryers), resource-efficient dishwashers, an innovative dual flush low-flow toilet, low-flow showerheads, and faucet aerators. The significance of this activity lies in its integrated approach and unique metering evaluation of individual end-use, aggregated residential total use, and system-wide energy and water benefits.
Date: May 3, 2001
Creator: Sullivan, Gregory P.; Elliott, Douglas B.; Hillman, Tim C.; Hadley, Adam; Ledbetter, Marc R. & Payson, David R.
Object Type: Report
System: The UNT Digital Library
ECRB REFUGE CHAMBER (open access)

ECRB REFUGE CHAMBER

The purpose of this calculation is to identify the initial design requirements for refuge stations, including the client requirements, standards, codes, laws, and regulations, general discipline design criteria, and design basis events and hazards. The scope of this document is for the specific task of designing and constructing refuge stations in the Enhanced Characterization Repository Block (ECRB) subsurface openings as necessary personnel safety enhancements to the current construction, maintenance and testing operations. This document is for the construction at the Exploratory Site Facility (ESF). The criteria is not intended to be incorporated into the proposed repository design and does not support Site Recommendation or License Application efforts. This calculation is prepared in accordance with N-3.12Q as a field support calculation and was prepared using the ''Technical Work Plan for Test Facilities Design FY01 Work Activities'' (TWP) (CRWMS M&O 2000b).
Date: December 3, 2001
Creator: Keifer, J. W.
Object Type: Report
System: The UNT Digital Library
Evaluation of the Thermal Response of the 5-DHLWaste Package-Hypothetical Fire Accident (open access)

Evaluation of the Thermal Response of the 5-DHLWaste Package-Hypothetical Fire Accident

The purpose of this calculation is to determine the thermal response of the 5-defense high level waste (DHLW)/Department of Energy (DOE) codisposal waste package (WP) to the hypothetical fire accident. The objective is to calculate the temperature response of the DHLW glass to the hypothetical short-term fire defined in 10 CFR 71, Section 73(c)(4), Reference 1. The scope of the calculation includes evaluation of the accident with the waste package above ground, at the Yucca Mountain surface facility. The scope is intended to cover a DHLW WP. This WP is loaded with DHLW canisters containing glass from the Savannah River Site (SRS) and a DOE canister containing Training, Research, and Isotope General Atomics (TRIGA) spent nuclear fuel (SNF). The information provided by the sketches attached to this calculation is that for the potential design of the type of WP considered in this calculation. In addition to the nominal design configuration thermal load case, the effects of varying the central DOE canister and DHLW thermal loads are determined. Also, the effects of varying values of the flame and WP outer surface emissivities are evaluated.
Date: November 3, 2001
Creator: Moore, R.W.
Object Type: Report
System: The UNT Digital Library
Flow channeling and analysis of tracer tests in heterogeneous porous media (open access)

Flow channeling and analysis of tracer tests in heterogeneous porous media

Flow and solute transport through porous medium with strongly varying hydraulic conductivity are studied by numerical simulations. The heterogeneity of the porous medium is defined by {sigma} and {lambda}{prime}, which are, respectively, the standard deviation of natural log of permeability values and its correlation range {lambda} divided by transport distance L. The development of flow channeling as a function of these two parameters is demonstrated. The results show that for large heterogeneities, the flow is highly channelized and solute is transported through a few fast paths, and the corresponding breakthrough curves show a high peak at very early times, much shorter than the mean residence time. This effect was studied for a converging radial flow, to simulate tracer tests in a fracture zone or contact-thickness aquifer. It is shown that {sigma}{sup 2}{lambda}{prime} is an appropriate parameter to characterize the tracer dispersion and breakthrough curves. These results are used to study tracer breakthrough data from field experiments performed with nonsorbing tracers. A new procedure is proposed to analyze the results. From the moments of the residence-time distribution represented by the breakthrough curves, the heterogeneity of the porous medium, as characterized by {sigma}{sup 2}{lambda}{prime} and the mean residence time t{sub o}, may …
Date: November 3, 2001
Creator: Moreno, Luis & Tsang, Chin-Fu
Object Type: Article
System: The UNT Digital Library
Gauge-Higgs unification in higher dimensions (open access)

Gauge-Higgs unification in higher dimensions

None
Date: September 3, 2001
Creator: Hall, Lawrence; Nomura, Yasunori & Smith, David
Object Type: Article
System: The UNT Digital Library
Mathematical and numerical studies of nonstandard difference equation models of differential equations. Final technical report (open access)

Mathematical and numerical studies of nonstandard difference equation models of differential equations. Final technical report

This report summarizes the complete research findings of the PI. Included are titles and places of publication of all journal, book, and conference papers, and abstracts. A listing of major conferences and meetings where these research results were reported is also provided.
Date: October 3, 2001
Creator: Mickens, Ronald E.
Object Type: Report
System: The UNT Digital Library
Performance of Planted Herbaceous Species in Longleaf Pine (Pinus palustris Mill.) Plantations: Overstory Effects of Competition and Needlefall (open access)

Performance of Planted Herbaceous Species in Longleaf Pine (Pinus palustris Mill.) Plantations: Overstory Effects of Competition and Needlefall

Research to determine the separate effects of above-ground and below-ground competition and needlefall of over-story pines on under-story plant performance. Periodic monitoring of over-story crown closure, soil water content, temperature, and nutrients were conducted. Results indicate competition for light had a more determental effect on performance of herbaceous species in longleaf pine plantations than that resulting from competition for below-ground resources.
Date: July 3, 2001
Creator: Dagley, Christa Marie
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Relativistic Thomson Scattering Experiment at BNL - Status Report (open access)

Relativistic Thomson Scattering Experiment at BNL - Status Report

1.7 x 10{sup 8} x-ray photons per 3.5 ps pulse have been produced in Thomson scattering by focusing CO{sub 2} laser pulse on counter-propagating relativistic electron beam. We explore a possibility of further enhancement of process efficiency by propagating both beams in a plasma capillary. Conventional synchrotron light sources based on using giga-electron-volt electron synchrotron accelerators and magnetic wigglers generate x-ray radiation for versatile application in multi-disciplinary research. An intense laser beam causes relativistic electron oscillations similar to a wiggler. However, because the laser wavelength is thousand times shorter than a wiggler period, very moderate electron energy is needed to produce hard x-rays via Thomson scattering. This allows using relatively compact mega-electron-volt linear accelerators instead of giga-electron-volt synchrotrons. Another important advantage of Thomson sources is a possibility to generate femtosecond x-ray pulses whereas conventional synchrotron sources have typically {approx}300 ps pulse duration. This promises to revolutionize x-ray research in chemistry, physics, and biology expanding it to ultra-fast processes. Thomson sources do not compete in repetition rate and average intensity with conventional light sources that operate at the megahertz frequency. However, Thomson sources have a potential to produce much higher photon numbers per pulse. This may allow developing a single shot …
Date: December 3, 2001
Creator: Pogorelsky, I. V.; Ben-Zvi, Ilan; Kusche, K.; Siddons, P.; Yakimenko, V.; Hirose, T. et al.
Object Type: Article
System: The UNT Digital Library
Overview of the NSTX Control System (open access)

Overview of the NSTX Control System

The National Spherical Torus Experiment (NSTX) is an innovative magnetic fusion device that was constructed by the Princeton Plasma Physics Laboratory (PPPL) in collaboration with the Oak Ridge National Laboratory, Columbia University, and the University of Washington at Seattle. Since achieving first plasma in 1999, the device has been used for fusion research through an international collaboration of more than twenty institutions. The NSTX is operated through a collection of control systems that encompass a wide range of technology, from hardwired relay controls to real-time control systems with giga-FLOPS of capability. This paper presents a broad introduction to the control systems used on NSTX, with an emphasis on the computing controls, data acquisition, and synchronization systems.
Date: December 3, 2001
Creator: Sichta, P.; Dong, J.; Oliaro, G. & Roney, P.
Object Type: Report
System: The UNT Digital Library
Final progress report for DOE grant [Protein dynamics and biocatalysis] (open access)

Final progress report for DOE grant [Protein dynamics and biocatalysis]

The purpose of this project was to develop and apply large-scale computer simulation methods to enzyme reactions and protein dynamics. New approaches based on the QM/MM methodology were formulated. New insights on the reaction mechanisms of triosephosphate isomerase and chorismate mutase were obtained.
Date: September 3, 2001
Creator: Karplus, Martin
Object Type: Report
System: The UNT Digital Library
Measuring and Modeling Flow in Welded Fractured Tuffs (open access)

Measuring and Modeling Flow in Welded Fractured Tuffs

We have carried out a series of in situ liquid-release experiments in conjunction with a numerical modeling study to examine the effect of the rock matrix on liquid flow and transport occurring primarily through the fracture network. Field experiments were conducted in the highly fractured Topopah Spring welded tuff at a site accessed from the Exploratory Studies Facility (ESFS), an underground laboratory in the unsaturated zone at Yucca Mountain, Nevada. During the experiment, wetting-front movement, flow-field evolution, and drainage of fracture flow paths were evaluated. Modeling was used to aid in experimental design, predict experimental results, and study the physical processes accompanying liquid flow through unsaturated fractured welded tuff. Field experiments and modeling suggest that it may not be sufficient to conceptualize the fractured tuff as consisting of a single network of high-permeability fractures embedded in a low-permeability matrix. The need to include a secondary fracture network is demonstrated by comparison to the liquid flow observed in the field.
Date: October 3, 2001
Creator: Salve, R.; Doughty, C. & Wang, J.S.
Object Type: Report
System: The UNT Digital Library
High intensity metal ion beam production with ECR ion sources (open access)

High intensity metal ion beam production with ECR ion sources

None
Date: September 3, 2001
Creator: Wutte, Daniela; Abbott, S.; Leitner, Matthaeus A. & Lyneis, Claude M.
Object Type: Article
System: The UNT Digital Library
Microstructure of laterally overgrown GaN layers (open access)

Microstructure of laterally overgrown GaN layers

Transmission electron microscopy study of plan-view and cross-section samples of epitaxial laterally overgrown (ELOG) GaN samples is described. Two types of dislocation with the same type of Burgers vector but different line direction have been observed. It is shown that threading edge dislocations bend to form dislocation segments in the c-plane as a result of shear stresses developed in the wing material along the stripe direction. It is shown that migration of these dislocations involves both glide and climb. Propagation of threading parts over the wing area is an indication of high density of point defects present in the wing areas on the ELOG samples. This finding might shed new light on the optical properties of such samples.
Date: April 3, 2001
Creator: Liliental-Weber, Zuzanna & Cherns, David
Object Type: Article
System: The UNT Digital Library
Thermal-Hydraulics and Electrochemistry of a Boiling Solution in a Porous Sludge Pile A Test Methodology (open access)

Thermal-Hydraulics and Electrochemistry of a Boiling Solution in a Porous Sludge Pile A Test Methodology

When boiling occurs in a pile of porous corrosion products (sludge), chemical species can concentrate. These species can react with the corrosion products and transform the sludge into a rock hard mass and/or create a corrosive environment. In-situ measurements are required to improve the understanding of this process, and the thermal-hydraulic and electrochemical environment in the pile. A test method is described that utilizes a water heated instrumented tube array in an autoclave to perform the in-situ measurements. As a proof of method feasibility, tests were performed in an alkaline phosphate solution. The test data is discussed. Temperature changes and electrochemical potential shifts were used to indicate when chemicals concentrate and if/when the pile hardens. Post-test examinations confirmed hardening occurred. Experiments were performed to reverse the hardening process. A one-dimensional model, utilizing capillary forces, was developed to understand the thermal-hydraulic measurements.
Date: May 3, 2001
Creator: Voelker, R.F.
Object Type: Report
System: The UNT Digital Library
Vapor-Phase Garnet at Yucca Mountain, Nevada: Geochemistry and Oxygen-Isotope Thermometry (open access)

Vapor-Phase Garnet at Yucca Mountain, Nevada: Geochemistry and Oxygen-Isotope Thermometry

About 20 vapor-phase garnets were studied in two samples of the Topopah Spring Tuff from Yucca Mountain, in southern Nevada. The Miocene-age Topopah Spring Tuff is a 350-m-thick, devitrified, moderately to densely welded ash flow that is compositionally zoned from high-silica rhyolite to quartz latite. During cooling of the tuff, escaping vapor produced lithophysae (former gas cavities) lined with an assemblage of tridymite, cristobalite, alkali feldspar, and locally, hematite and/or garnet. Vapor-phase topaz and economic deposits (such as porphyry molybdenum-tungsten) commonly associated with topaz-bearing rhyolites (characteristically enriched in fluorine) were not found in the Topopah Spring Tuff at Yucca Mountain. The garnets are not primary igneous phenocrysts, but rather crystals that grew from a fluorine-poor magma-derived vapor trapped during emplacement of the tuff. The garnets are euhedral, vitreous, reddish brown, trapezohedral, as large as 2 mm in diameter, and fractured. The garnets also contain inclusions of tridymite. Electron-microprobe analyses of the garnets reveal that they are almandine-spessartine (48.0 and 47.9 mol percent, respectively), have an average chemical formula of (Fe{sub 1.46}, Mn{sub 1.45}, Mg{sub 0.03}, Ca{sub 0.10}) (Al{sub 1.93}, TiO{sub 0.02}) Si{sub 3.01}O{sub 12}, and are homogeneous in Fe and Mn concentrations from core to rim. Composited garnets from each …
Date: July 3, 2001
Creator: Moscati, R. J.; Johnson, C. A. & Whelan, J. F.
Object Type: Report
System: The UNT Digital Library
co2 Lasers in High Energy Physics. (open access)

co2 Lasers in High Energy Physics.

Several proof-of-principle laser accelerator experiments turned a long-wavelength of a CO{sub 2} laser to advantage. Ongoing advancement to multi-terawatt femtosecond CO{sub 2} lasers opens new venues for next-generation laser acceleration research.
Date: December 3, 2001
Creator: Pogorelsky, I. V.
Object Type: Article
System: The UNT Digital Library
The Role of Axisymmetric Reconnection Events in JET Discharges with Extreme Shear Reversal (open access)

The Role of Axisymmetric Reconnection Events in JET Discharges with Extreme Shear Reversal

Injection of Lower Hybrid Heating and Current Drive into the current ramp-up phase of Joint European Torus (JET) discharges can produce extremely reversed q-profiles characterized by a core region of very small or zero current density (within Motional Stark Effect diagnostic measurement errors) and q(subscript min) > 1. T(subscript e)-profiles show sawtooth-like collapses and the presence of an internal transport barrier. Accurate equilibrium reconstructions of these discharges are obtained using the ESC code, which was recently extended to allow equilibrium reconstructions in which a free boundary solver determines the plasma boundary and a fixed boundary solver provides the magnetic geometry and current density profile. The core current density does not appear to go negative, although current diffusion calculations indicate that sufficient non-inductive current drive to cause this is present. This is explained by nonlinear resistive MHD simulations in toroidal geometry which predict that these discharges undergo n=0 reconnection events (axisymmetric sawteeth) that redistribute the current to hold the core current density near zero.
Date: December 3, 2001
Creator: Stratton, B. C.; Breslau, J. A.; Budny, R. V.; Jardin, S. C.; Park, W.; Strauss, H. R. et al.
Object Type: Report
System: The UNT Digital Library
CO2 SELECTIVE CERAMIC MEMBRANE FOR WATER-GAS SHIFT REACTION WITH CONCOMITANT RECOVERY OF CO2 (open access)

CO2 SELECTIVE CERAMIC MEMBRANE FOR WATER-GAS SHIFT REACTION WITH CONCOMITANT RECOVERY OF CO2

This quarterly report focuses on the two specific topics: (1) Reversibility of CO{sub 2} affinity of hydrotalcite materials; and (2)In-situ crystallization of hydrotalcite on commercial tubular ceramic membrane as substrate. The former relates to the foundation of the use of the hydrotalcite material as a membrane. The later addresses the first step of the membrane synthesis we propose. Our study concludes that the CO{sub 2} affinity of the hydrotalcite material is reversible at 150 C and in the presence of water using TG/MS. Additional study at a high pressure and/or high temperature will be performed to scope the operating range of the membrane. On the other hand, the in-situ crystallization is proven to be an effective first step for the hydrotalcite membrane synthesis. Our result indicates that about hydrotalcite covers about 50% of the porosity of the substrate, ideal as a seed for the 2nd step involving in-situ crystal growth. Our next quarterly report will report the result from the study on the 2nd step.
Date: October 3, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library