Resource Type

Texas Racing Commission Annual Report: 1999 (open access)

Texas Racing Commission Annual Report: 1999

Annual report of the Texas Racing Commission describing goals, activities, and accomplishments during the fiscal year 1999.
Date: July 11, 2000
Creator: Texas Racing Commission
System: The Portal to Texas History
The Continued Risk Of Troubled Assets (open access)

The Continued Risk Of Troubled Assets

August report of the U.S. Congressional Oversight Panel describing their activities and findings regarding the risk of troubled assets, including sections on background information, strategies for dealing with troubled assets, and the future of troubled assets.
Date: August 11, 2009
Creator: United States. Congressional Oversight Panel.
System: The UNT Digital Library
Final Report LDRD 02-ERD-013 Dense Plasma Characterization by X-ray Thomson Scattering (open access)

Final Report LDRD 02-ERD-013 Dense Plasma Characterization by X-ray Thomson Scattering

We have successfully demonstrated spectrally-resolved x-ray scattering in a variety of dense plasmas as a powerful new technique for providing microscopic dense plasma parameters unattainable by other means. The results have also been used to distinguish between ionization balance models. This has led to 10 published or to be published papers, 8 invited talks and significant interest from both internal and external experimental plasma physicists and the international statistical plasma physics theory community.
Date: February 11, 2005
Creator: Landen, O L; Glenzer, S H; Gregori, G; Pollaine, S M; Hammer, J H; Rogers, F et al.
System: The UNT Digital Library
Wireless link design using a patch antenna (open access)

Wireless link design using a patch antenna

A wireless link was designed using a patch antenna. In the process, several different models were tested. Testing proved a patch antenna was a viable solution for building a wireless link within the design specifications. Also, this experimentation provided a basis for future patch antenna design.
Date: August 11, 2000
Creator: Hall, E.
System: The UNT Digital Library
Tearing and MHD Instability During Gun Injection into a Spheromak (open access)

Tearing and MHD Instability During Gun Injection into a Spheromak

Linear stability analysis of a two-cylinder approximation to gun injection--one cylinder to represent the confined spheromak and another to represent the gun--is shown to yield equilibria in which tearing modes exist simultaneously at the magnetic axis and at the geometric (gun) axis, as might be required to sustain helicity injection. These equilibria are MHD stable at the two axes but may have localized MHD instability at an interior minimum in the q profile. The theory predicts two tearing thresholds with successively deeper q minima as the gun current is increased at constant bias flux.
Date: May 11, 2000
Creator: Fowler, T K
System: The UNT Digital Library
Re-Assessing the Maximum Allowed Infrared (IR) Power for Enchanced Layering in a Conduction Dominated Cryogenic NIF-Scale Hohlraum (open access)

Re-Assessing the Maximum Allowed Infrared (IR) Power for Enchanced Layering in a Conduction Dominated Cryogenic NIF-Scale Hohlraum

Recent measurements of the infrared (IR) absorption coefficient of CH and CD capsules differ significantly from earlier estimated values from thin flat samples. The optimum wavelength for IR enhanced layering of DT and D{sub 2} ice layers inside of a NIF scale hohlraum depends on the relative ice and capsule absorption coefficients. This update of a previous memo shows the maximum ice heating with IR as a function of ice and capsule absorption instead of at discrete wavelengths. Also discussed is the leverage of other parameters, such as the IR absorption of the hohlraum wall and thermal conductivities of the support rods and exchange gas. The most likely capsule and ice absorption values limit the IR heating to between 2-7 Q{sub DT}. We find most leverage of the IR heating comes from increasing the ice to capsule absorption ratio. As before, this is the conduction only limit to IR, with convection potentially playing a large role.
Date: August 11, 2003
Creator: Kozioziemski, B J
System: The UNT Digital Library
Kinetics of Solid Phase Reactions at High Pressure and Temperature (open access)

Kinetics of Solid Phase Reactions at High Pressure and Temperature

We report on the subject of temperature and/or pressure induced solid-solid phase transitions of energetic molecular crystals. Over the last three years we have applied experimental techniques that when used simultaneously provide insight into some of the complexities that govern reaction rate processes. After more than 55 years of study a global kinetics model describing the P-T phase space transition kinetics of such materials as HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) is not only missing, but from a formal perspective is perhaps as many years away from completion. The essence of this report describes what material parameters affect first-order reaction rates of the CHNO moiety of molecular crystals and introduces the application of new experimental tools thus permitting quantifiable studies of important rate limiting mechanisms.
Date: February 11, 2002
Creator: Zaug, J M; Farber, D L; Saw, C K & Weeks, B L
System: The UNT Digital Library
Investigate Methods to Decrease Compilation Time-AX-Program Code Group Computer Science R& D Project (open access)

Investigate Methods to Decrease Compilation Time-AX-Program Code Group Computer Science R& D Project

Large simulation codes can take on the order of hours to compile from scratch. In Kull, which uses generic programming techniques, a significant portion of the time is spent generating and compiling template instantiations. I would like to investigate methods that would decrease the overall compilation time for large codes. These would be methods which could then be applied, hopefully, as standard practice to any large code. Success is measured by the overall decrease in wall clock time a developer spends waiting for an executable. Analyzing the make system of a slow to build project can benefit all developers on the project. Taking the time to analyze the number of processors used over the life of the build and restructuring the system to maximize the parallelization can significantly reduce build times. Distributing the build across multiple machines with the same configuration can increase the number of available processors for building and can help evenly balance the load. Becoming familiar with compiler options can have its benefits as well. The time improvements of the sum can be significant. Initial compilation time for Kull on OSF1 was {approx} 3 hours. Final time on OSF1 after completion is 16 minutes. Initial compilation time …
Date: June 11, 2003
Creator: Cottom, T
System: The UNT Digital Library
HUNTING THE QUARK GLUON PLASMA. (open access)

HUNTING THE QUARK GLUON PLASMA.

The U.S. Department of Energy's Relativistic Heavy Ion Collider (RHIC) construction project was completed at BNL in 1999, with the first data-taking runs in the summer of 2000. Since then the early measurements at RHIC have yielded a wealth of data, from four independent detectors, each with its international collaboration of scientists: BRAHMS, PHENIX, PHOBOS, and STAR [1]. For the first time, collisions of heavy nuclei have been carried out at colliding-beam energies that have previously been accessible only for high-energy physics experiments with collisions of ''elementary'' particles such as protons and electrons. It is at these high energies that the predictions of quantum chromodynamics (QCD), the fundamental theory that describes the role of quarks and gluons in nuclear matter, come into play, and new phenomena are sought that may illuminate our view of the basic structure of matter on the sub-atomic scale, with important implications for the origins of matter on the cosmic scale. The RHIC experiments have recorded data from collisions of gold nuclei at the highest energies ever achieved in man-made particle accelerators. These collisions, of which hundreds of millions have now been examined, result in final states of unprecedented complexity, with thousands of produced particles radiating …
Date: April 11, 2005
Creator: LUDLAM, T. & ARONSON, S.
System: The UNT Digital Library
Groundwater Data Package for the 2004 Composite Analysis (open access)

Groundwater Data Package for the 2004 Composite Analysis

This report presents data and information that supports the groundwater module. The conceptual model of groundwater flow and transport at the Hanford Site is described and specific information applied in the numerical implementation module is provided.
Date: August 11, 2004
Creator: Thorne, Paul D.
System: The UNT Digital Library
A Study of the Ion Hose Instability in the DARHT-II Downstream Transport Region (open access)

A Study of the Ion Hose Instability in the DARHT-II Downstream Transport Region

The second axis of the DARHT flash X-ray facility at Los Alamos National Laboratory (''DARHT-II'') is a multiple-pulse, 18.4 MeV, 2 kA induction electron linear accelerator [1]. A train of short ({approx}50 ns) pulses are converted via bremsstrahlung to X-rays, which are then used to make radiographic images at various times (nominally four) during a ''hydrotest'' experiment. The train of pulses is created by carving them out of a two microsecond long macropulse, using a fast switching element called a kicker [2]. The unused portion of the macropulse is absorbed in a beam dump. Thus, upstream of the kicker, two microseconds of beam are transported through a vacuum system roughly sixty meters long. These conditions involve length and, specifically, time scales which are new to the transport of high-current beams. A concern under such conditions are the macroscopic interactions between the electron beam and positive ions created by impact ionization of the residual gas in the vacuum system. Over two microseconds, the ion density can develop to a hundredth or even a tenth of a percent of the beam density--small, to be sure, but large enough to have cumulative effects over such a long transport distance. Two such effects will …
Date: November 11, 2004
Creator: McCarrick, J F
System: The UNT Digital Library
Rapid Generation of a Nanocrystal-Labeled Peptide Library for Specific Identification of the Bacterium Clostrium Botulinum (open access)

Rapid Generation of a Nanocrystal-Labeled Peptide Library for Specific Identification of the Bacterium Clostrium Botulinum

Several peptide libraries containing up to 2 million unique peptide ligands have been synthesized. The peptides are attached onto a 80 micron resin and the length of these peptide ligands ranges from 5 to 9 amino acid residues. Using a novel calorimetric assay, the libraries were screened for binding to the ganglioside-binding domain of Clostridium Tetanus Toxin, a structural similar analog of the Clostridium Botulinum toxin. Several binding peptide sequences were identified, in which the detailed binding kinetics are currently underway using the Surface Plasmon Resonance (SPR) technique.
Date: November 11, 2004
Creator: Tok, J B
System: The UNT Digital Library
Seismic Monitoring for the United Arab Emirates (open access)

Seismic Monitoring for the United Arab Emirates

There is potential for earthquakes in the United Arab Emirates and in the Zagros mountains to cause structural damage and pose a threat to safety of people. Damaging effects from earthquakes can be mitigated by knowledge of the location and size of earthquakes, effects on construction, and monitoring these effects over time. Although a general idea of seismicity in the UAE may be determined with data from global seismic networks, these global networks do not have the sensitivity to record smaller seismic events and do not have the necessary accuracy to locate the events. A National Seismic Monitoring Observatory is needed for the UAE that consists of a modern seismic network and a multidisciplinary staff that can analyze and interpret the data from the network. A seismic network is essential to locate earthquakes, determine event magnitudes, identify active faults and measure ground motions from earthquakes. Such a network can provide the data necessary for a reliable seismic hazard assessment in the UAE. The National Seismic Monitoring Observatory would ideally be situated at a university that would provide access to the wide range of disciplines needed in operating the network and providing expertise in analysis and interpretation.
Date: April 11, 2005
Creator: Rodgers, A. & Nakanishi, K.
System: The UNT Digital Library
Final Report 02-ERD-033: Rapid Resolidification of Metals using Dynamic Compression (open access)

Final Report 02-ERD-033: Rapid Resolidification of Metals using Dynamic Compression

The purpose of this project is to develop a greater understanding of the kinetics involved during a liquid-solid phase transition occurring at high pressure and temperature. Kinetic limitations are known to play a large role in the dynamics of solidification at low temperatures, determining, e.g., whether a material crystallizes upon freezing or becomes an amorphous solid. The role of kinetics is not at all understood in transitions at high temperature when extreme pressures are involved. In order to investigate time scales during a dynamic compression experiment we needed to create an ability to alter the length of time spent by the sample in the transition region. Traditionally, the extreme high-pressure phase diagram is studied through a few static and dynamic techniques: static compression involving diamond anvil cells (DAC) [1], shock compression [2, 3], and quasi-isentropic compression [4, 5, 6, 7, 8, 9, 10]. Static DAC experiments explore equilibrium material properties along an isotherm or an isobar [1]. Dynamic material properties can be explored with shock compression [2, 3], probing single states on the Hugoniot, or with quasi-isentropic compression [4, 5, 6, 7, 8, 9, 10]. In the case of shocks, pressures variation typically occurs on a sub-nanosecond time scale or …
Date: February 11, 2005
Creator: Streitz, F. H.; Nguyen, J. H.; Orlikowski, D.; Minich, R.; Moriarty, J. A. & Holmes, N. C.
System: The UNT Digital Library
The May 18, 1998 Indian Nuclear Test Seismograms at station NIL (open access)

The May 18, 1998 Indian Nuclear Test Seismograms at station NIL

The last underground nuclear tests were conducted by India and Pakistan in May 1998. Although the Comprehensive Test Ban Treaty has not entered force, an International Monitoring System (IMS), established by the treaty is nearing completion. This system includes 170 seismic stations, a number of them originally established by IRIS. The station IRIS station NIL (Nilore, Pakistan) is close to a planned IMS primary station and recorded some very interesting seismograms from the May 18, 1998 Indian test. We carefully calibrated the path to NIL using a prior Mw 4.4 that occurred on April 4, 1995 about 110 km north of the Indian test site. We used joint epicentral location techniques along with teleseismic P waves and regional surface waves to fix the epicenter, depth, mechanism and moment of this event. From these we obtained a velocity model for the path to NIL and created explosion synthetic seismograms to compare with the data. Interestingly the observed Rayleigh waves are reversed, consistent with an implosion rather than an explosion source. The preferred explanation is that the explosion released tectonic stress near the source region, which can be modeled as a thrust earthquake of approximate Mw 4.0 plus a pure explosion. This …
Date: April 11, 2005
Creator: Walter, W R; Rodgers, A J; Bowers, D & Selby, N
System: The UNT Digital Library
Large Diffractive Optics for GEo-Based Earth Surveillance (open access)

Large Diffractive Optics for GEo-Based Earth Surveillance

The natural vantage point for performing Earth-centric operations from space is geosynchronous orbit (GEO); a platform there moves at the same rate as the Earth's surface, so appears to continually ''hover'' over a fixed site on the Earth. Unlike spacecraft in other orbits, which rapidly fly-over targets, a GEO-based platform remains in-position all the time. In order to insure continual access to sites using low earth orbit (LEO) platforms, one needs a large enough constellation ({approx} 50) of spacecraft so that one is always overhead; in contrast, a single GEO platform provides continuous coverage over sites throughout Euro-Asia. This permanent coverage comes, unfortunately, with a stiff price-tag; geosynchronous orbit is 36,000 km high, so space platforms there must operate at ranges roughly 100 times greater than ones located in LEO. For optical-based applications, this extreme range is difficult to deal with; for surveillance the price is a 100-fold loss of resolution, for laser weapons it is a 10,000-fold loss in flux-on-target. These huge performance penalties are almost always unacceptable, preventing us from successfully using GEO-based platforms. In practice, we are forced to either settle for brief, infrequent access to targets, or, if we demand continuous coverage, to invest in large, …
Date: September 11, 2003
Creator: Hyde, R A
System: The UNT Digital Library
Methods for Calibrating Basin-Wide Hydroacoustic Propagation in the Indian Ocean (open access)

Methods for Calibrating Basin-Wide Hydroacoustic Propagation in the Indian Ocean

This collaborative project was designed to test and compare methods for achieving full ocean basin propagation of hydroacoustic signals in the 5-100 Hz frequency band. Plans for a systematic calibration of the International Monitoring System (IMS) for nuclear testing were under consideration in 2000/2001. The results from this project provide information to guide such planning for future ocean basin calibration work. Several acoustic source types were tested during two sea-going experiments and most were successful at generating signals that propagated hundreds to thousands of km to be recorded at the Indian Ocean IMS hydrophone stations. Development and numerical modeling of imploding glass sphere sources was one component of this testing. The intent was to design a relatively simple-to-use source that is not subject to restrictions that can limit use of explosive charges, but whose signal is large enough to propagate 100-1000's km range. Analysis of IMS hydrophone data recording during the experiments was used to illustrate the extent of energy loss during signal propagation and to assess the accuracy with which the small acoustic sources could be located using methods typically employed for nuclear monitoring.
Date: October 11, 2004
Creator: Blackman, D; de Groot-Hedlin, C; Orcutt, J A; Harben, P H; Clarke, D B & Ramirez, A L
System: The UNT Digital Library
Effects of Introduced Materials in the Drift Scale Test (open access)

Effects of Introduced Materials in the Drift Scale Test

Water samples previously acquired from superheated (>140 C) zones within hydrological test boreholes of the Drift Scale Test (DST) show relatively high fluoride concentrations (5-66 ppm) and low pH (3.1-3.5) values. In these high temperature regions of the rock, water is present superheated vapor only--liquid water for sampling purposes is obtained during the sampling process by cooling. Based on data collected to date, it is evident that the source of the fluoride and low pH is from introduced man-made materials (Teflon{trademark} and/or Viton{trademark} fluoroelastomer) used in the test. The test materials may contribute fluoride either by degassing hydrogen fluoride (HF) directly to produce trace concentrations of HF gas ({approx}0.1 ppm) in the high temperature steam, or by leaching fluoride in the sampling tubes after condensation of the superheated steam. HF gas is known to be released from Viton{trademark} at high temperatures (Dupont Dow Elastomers L.L.C., Elkton, MD, personal communication) and the sample water compositions indicate near stoichiometric balance of hydrogen ion and fluoride ion, indicating dissolution of HF gas into the aqueous phase. These conclusions are based on a series of water samples collected to determine if the source of the fluoride is from the degradation of materials originally installed …
Date: January 11, 2002
Creator: DeLoach, L & Jones, RL
System: The UNT Digital Library
Stochastic Engine Convergence Diagnostics (open access)

Stochastic Engine Convergence Diagnostics

The stochastic engine uses a Markov Chain Monte Carlo (MCMC) sampling device to allow an analyst to construct a reasonable estimate of the state of nature that is consistent with observed data and modeling assumptions. The key engine output is a sample from the posterior distribution, which is the conditional probability distribution of the state of nature, given the data. In applications the state of nature may refer to a complicated, multi-attributed feature like the lithology map of a volume of earth, or to a particular related parameter of interest, say the centroid of the largest contiguous sub-region of specified lithology type. The posterior distribution, which we will call f, can be thought of as the best stochastic description of the state of nature that incorporates all pertinent physical and theoretical models as well as observed data. Characterization of the posterior distribution is the primary goal in the Bayesian statistical paradigm. In applications of the stochastic engine, however, analytical calculation of the posterior distribution is precluded, and only a sample drawn from the distribution is feasible. The engine's MCMC technique, which employs the Metropolis-Hastings algorithm, provides a sample in the form of a sequence (chain) of possible states of nature, …
Date: December 11, 2001
Creator: Glaser, R
System: The UNT Digital Library
Review of Excess Weapons Plutonium Disposition LLNL Contract Work in Russia-(English) (open access)

Review of Excess Weapons Plutonium Disposition LLNL Contract Work in Russia-(English)

This third meeting of the recently completed and ongoing Russian plutonium immobilization contract work was held at the State Education Center (SEC) in St. Petersburg on January 14-18, 2002. The meeting agenda is reprinted here as Appendix A and the attendance list as Appendix B. The meeting had 58 Russian participants from 21 Russian organizations, including the industrial sites (Mayak, Krasonayarsk-26, Tomsk), scientific institutes (VNIINM, KRI, VNIPIPT, RIAR), design organizations (VNIPIET and GSPI), universities (Nyzhny Novgorod, Urals Technical), Russian Academy of Sciences (Institute of Physical Chemistry or IPhCh, Institute of Ore-Deposit Geology, Petrography, Mineralogy, and Geochemistry or IGEM), Radon-Moscow, S&TC Podol'osk, Kharkov-Ukraine, GAN-SEC-NRS and SNIIChM, the RF Ministry of Atomic Energy (Minatom) and Gosatomnadzor (GAN). This volume, published by LLNL, documents this third annual meeting. Forty-nine technical papers were presented by the Russian participants, and nearly all of these have been collected in this Proceedings. The two objectives for the meeting were to: (1) Bring together the Russian organizations, experts, and managers performing this contract work into one place for four days to review and discuss their work amongst each other. (2) Publish a meeting summary and proceedings of all the excellent Russian plutonium immobilization and other plutonium disposition contract …
Date: July 11, 2002
Creator: Jardine, L & Borisov, G B
System: The UNT Digital Library
Tests of the Contamination Analysis Unit, Phase 2 (open access)

Tests of the Contamination Analysis Unit, Phase 2

Lawrence Livermore National Laboratory (LLNL) has developed a mass spectrometer-based system that measures organic surface residues in situ. This system, called the Contamination Analysis Unit (CAU), can detect and quantify a variety of volatile surface residues on a range of different substrates. Residue samples are removed from the substrate using a combination of vacuum and thermal desorption, and are then ionized and quantified by a quadrupole mass spectrometer. The current effort (Phase 2) was carried out in accordance with Thiokol Project Test Plan PTP-0467. A first phase of tests was completed under PTP-0327 and the results reported in TWR-75385. The Phase 2 test plan, PTP-0467, is a follow-on to PTP-0327, and was conducted in order to more fully determine the capabilities of the CAU. This report summarizes experiments in which the CAU was evaluated for application in reusable solid rocket motor production scenarios. The report has been ordered by the tasks requested by ATK Thiokol Propulsion Testplan PTP-0467. Project tasks included the following: (1) Determine the amount of residual propellant and liner components with the CAU after coupons have been cleaned. (2) Determine if the CAU can detect solvent that has soaked into NBR. (3) Test the capabilities of the …
Date: September 11, 2003
Creator: Meltzer, Michael & Daley, Paul
System: The UNT Digital Library
Simulation Analysis of Inspections of International Travelers at Los Angeles International Airport for US-VISIT (open access)

Simulation Analysis of Inspections of International Travelers at Los Angeles International Airport for US-VISIT

The United States Visitor and Immigrant Status Indicator Technology Program (US-VISIT) will deploy biometric and other systems to identify and track foreign nationals entering and exiting the U.S. Evaluation of the large number of possible policy options and technical configurations for implementation of US-VISIT requires validated system analyses with appropriate tools that can address the requirements of this new program and its processes. Early identification of performance issues and capability gaps will prove critical to the success of the program.
Date: February 11, 2004
Creator: Edmunds, T.; Sholl, P.; Yao, Y.; Gansemer, J.; Cantwell, E.; Prosnitz, D. et al.
System: The UNT Digital Library
Simulations of Turbulence Induced Ellipticity Over Large Fields-of-View: The First Step Towards Enabling LSST Weak Lensing Science (open access)

Simulations of Turbulence Induced Ellipticity Over Large Fields-of-View: The First Step Towards Enabling LSST Weak Lensing Science

Atmospheric turbulence can mimic the effects of weak lensing in astronomical images, so it is necessary to understand to what degree turbulence affects weak lensing measurements. In particular, we studied the ellipticity induced upon the point-spread functions (PSFs) of a grid of simulated stars separated by distances (d {approx} 1{prime}) that will be characteristic of Large Synoptic Survey Telescope (LSST) images. We observe that atmospherically induced ellipticity changes on small scales (d < 0.5{prime}) and use linear interpolation between stars separated by d = 0.5{prime} to determine the induced ellipticity everywhere in the field-of-view.
Date: October 11, 2004
Creator: Schlaufman, K
System: The UNT Digital Library
Reference Artifacts for NDE (open access)

Reference Artifacts for NDE

Two reference artifacts will be fabricated for this study. One of the artifacts will have a cylindrical geometry and will contain features similar to those on an SNRT target. The second artifact will have a spherical geometry and will contain features similar to those on a Double Shell target. The artifacts were designed for manufacturability and to provide a range of features that can be measured using NDE methods. The cylindrical reference artifact is illustrated in Figure 1. This artifact consists of a polystyrene body containing two steps and a machined slot, into which will fit a tracer made of doped polystyrene. The polystyrene body contains several grooves and can be fabricated entirely on a diamond turning machine. The body can be machined by turning a PS rod to a diameter slightly greater than the finished diameter of 2 mm. The part can be moved off-axis to face it off and to machine the steps, slot, and grooves. The tracer contains a drilled hole and a milled slot, which could be machined with a single setup on a milling machine. Once assembled, the artifact could be placed in a Be tube or other structure relevant to target assemblies. The assembled …
Date: February 11, 2003
Creator: Bono, M.; Hibbard, R. & Martz, H. E.
System: The UNT Digital Library