Aspects of the Tribology of the Plastic Bonded Explosive (PBX) 9404 (open access)

Aspects of the Tribology of the Plastic Bonded Explosive (PBX) 9404

The coefficient of friction, {mu}, of the plastic bonded explosive (PBX) 9404 was measured on stainless steel, aluminum, Teflon and the explosive itself as a function of temperature between ambient and 135 C at a rotational speed of 0.0025 rad/sec{sup -1}. An optical profilometer was used to analyze the mean surface roughness, R{sub a}, of the various materials. PBX 9404 is a composite of the explosive 1,3,5,7-tetranitroazacyclooctane (HMX) chloroethyl phosphate (CEF) and nitrocellulose in an 96/3/3 weight ratio. The average roughness of the pressed explosive surface was R{sub a} = 1.37 {micro}m. The coefficient of friction for PBX 9404 on stainless steel of R{sub a} = 0.40 {micro}m increased from 0.22 at ambient to 0.34 at 95 C. Above this temperature {mu} decreased to about 0.23 at 125 C. Similar behavior was observed with aluminum with R{sub a} = 0.31 {micro}m. The coefficient of friction increased from about 0.08 at ambient to 0.48 at 115 C. Above this temperature, {mu} tended to decrease slightly. The coefficient of friction against Teflon of R{sub a} = 0.054 {micro}m was sigmoidal, increasing from about 0.3 at ambient to about at 0.49 {+-} 0.002 above 115 C. Against a PBX 9404 counter surface, the …
Date: July 8, 2004
Creator: Hoffman, D. M. & Chandler, J. B.
Object Type: Article
System: The UNT Digital Library
Assistance to Firefighters Program: Distribution of Fire Grant Funding (open access)

Assistance to Firefighters Program: Distribution of Fire Grant Funding

The report is categorized into eight categories: (I) Background, (II) FY2001 Grants, (III) FY 2002 Grants,(IV) FY 2003 Grants, (V) FY 2004 Grants, (VI) Program Evaluation, (VII) Distribution of Fire Grants and (VIII) Activities in the 108th Congress.
Date: July 15, 2004
Creator: Kruger, Lennard G.
Object Type: Report
System: The UNT Digital Library
Associations between classroom CO2 concentrations and student attendance in Washington and Idaho (open access)

Associations between classroom CO2 concentrations and student attendance in Washington and Idaho

Student attendance in American public schools is a critical factor in securing limited operational funding. Student and teacher attendance influence academic performance. Limited data exist on indoor air and environmental quality (IEQ) in schools, and how IEQ affects attendance, health, or performance. This study explored the association of student absence with measures of indoor minus outdoor carbon dioxide concentration (dCO{sub 2}). Absence and dCO{sub 2} data were collected from 409 traditional and 25 portable classrooms from 14 schools located in six school districts in the states of Washington and Idaho. Study classrooms had individual heating, ventilation, and air conditioning (HVAC) systems, except two classrooms without mechanical ventilation. Classroom attributes, student attendance and school-level ethnicity, gender, and socioeconomic status (SES) were included in multivariate modeling. Forty-five percent of classrooms studied had short-term indoor CO{sub 2} concentrations above 1000 parts-per-million (ppm). A 1000 ppm increase in dCO{sub 2} was associated (p < 0.05) with a 0.5% to 0.9% decrease in annual average daily attendance (ADA), corresponding to a relative 10% to 20% increase in student absence. Outside air (ventilation) rates estimated from dCO{sub 2} and other collected data were not associated with absence. Annual ADA was 2% higher (p < 0.0001) in …
Date: July 25, 2004
Creator: Shendell, Derek G.; Prill, Richard; Fisk, William J.; Apte, Michael G.; Blake, David & Faulkner, David
Object Type: Article
System: The UNT Digital Library
Athens Olympics 2004: U.S. Government Involvement in Security Preparations (open access)

Athens Olympics 2004: U.S. Government Involvement in Security Preparations

This report discusses the U.S. government involvement in security preparations for the Athens Olympics 2004, the first Summer Games to be held since the September 11, 2001 terrorist attacks.
Date: July 28, 2004
Creator: Halchin, L. Elaine
Object Type: Report
System: The UNT Digital Library
Atomic Control Of Water Interaction With Biocompatible Surfaces: The Case Of SiC(001) (open access)

Atomic Control Of Water Interaction With Biocompatible Surfaces: The Case Of SiC(001)

The interaction of water with Si- and C- terminated {beta}-SiC(001) surfaces was investigated by means of ab initio molecular dynamics simulations. Irrespective of coverage, varied from 1/4 to 1 monolayer, we found that water dissociates on the Si-terminated surface, substantially modifying the clean surface reconstruction, while the C-terminated surface is nonreactive and hydrophobic. Based on our results, we propose that STM images and photoemission experiments may detect specific changes induced by water on both the structural and electronic properties of SiC(001) surfaces.
Date: July 19, 2004
Creator: Cicero, G; Catellani, A & Galli, G
Object Type: Article
System: The UNT Digital Library
An Audit Report on the Health and Human Services Commission's Administration of the CHIP Exclusive Provider Organization Contract (open access)

An Audit Report on the Health and Human Services Commission's Administration of the CHIP Exclusive Provider Organization Contract

Report of the Texas State Auditor's Office related to assessing the Health and Human Services Commission's (Commission) systems and controls for monitoring managed care contracts in connection with its Business Improvement Plan with respect to the Children's Health Insurance Program (CHIP) exclusive provider organization (EPO) contract and subcontracts.
Date: July 2004
Creator: Texas. Office of the State Auditor.
Object Type: Report
System: The Portal to Texas History
An Audit Report on the Public Utility Commission's Administration of the System Benefit Fund (open access)

An Audit Report on the Public Utility Commission's Administration of the System Benefit Fund

Report of the Texas State Auditor's Office related to determining whether the Public Utility Commission of Texas administered the System Benefit Fund in accordance with applicable laws and regulations.
Date: July 2004
Creator: Texas. Office of the State Auditor.
Object Type: Report
System: The Portal to Texas History
An Automated Inadvertent Intruder Analysis Application (open access)

An Automated Inadvertent Intruder Analysis Application

Savannah River National Laboratory is responsible for the radiological performance assessment analysis for Savannah River Site waste disposal facilities (McDowell-Boyer2000), which results in limits on the amounts of radiological substances that can be placed in the waste disposal facilities. To arrive at these limits, the performance assessment considers numerous potential exposure pathways that could occur in the future. One set of exposure scenarios, known as inadvertent intruder analysis, considers the impact on hypothetical individuals who are assumed to inadvertently intrude onto the waste disposal site. Inadvertent intruder analysis considers three distinct scenarios for exposure referred to as the agriculture scenario, the resident scenario, and the post-drilling scenario. Each of these scenarios has specific exposure pathways that contribute to the overall dose for the scenario.
Date: July 17, 2004
Creator: KOFFMAN, LARRYD.
Object Type: Report
System: The UNT Digital Library
Automated infrasound signal detection algorithms implemented in MatSeis - Infra Tool. (open access)

Automated infrasound signal detection algorithms implemented in MatSeis - Infra Tool.

MatSeis's infrasound analysis tool, Infra Tool, uses frequency slowness processing to deconstruct the array data into three outputs per processing step: correlation, azimuth and slowness. Until now, an experienced analyst trained to recognize a pattern observed in outputs from signal processing manually accomplished infrasound signal detection. Our goal was to automate the process of infrasound signal detection. The critical aspect of infrasound signal detection is to identify consecutive processing steps where the azimuth is constant (flat) while the time-lag correlation of the windowed waveform is above background value. These two statements describe the arrival of a correlated set of wavefronts at an array. The Hough Transform and Inverse Slope methods are used to determine the representative slope for a specified number of azimuth data points. The representative slope is then used in conjunction with associated correlation value and azimuth data variance to determine if and when an infrasound signal was detected. A format for an infrasound signal detection output file is also proposed. The detection output file will list the processed array element names, followed by detection characteristics for each method. Each detection is supplied with a listing of frequency slowness processing characteristics: human time (YYYY/MM/DD HH:MM:SS.SSS), epochal time, correlation, …
Date: July 1, 2004
Creator: Hart, Darren
Object Type: Report
System: The UNT Digital Library
Automated whole-genome multiple alignment of rat, mouse, and human (open access)

Automated whole-genome multiple alignment of rat, mouse, and human

We have built a whole genome multiple alignment of the three currently available mammalian genomes using a fully automated pipeline which combines the local/global approach of the Berkeley Genome Pipeline and the LAGAN program. The strategy is based on progressive alignment, and consists of two main steps: (1) alignment of the mouse and rat genomes; and (2) alignment of human to either the mouse-rat alignments from step 1, or the remaining unaligned mouse and rat sequences. The resulting alignments demonstrate high sensitivity, with 87% of all human gene-coding areas aligned in both mouse and rat. The specificity is also high: <7% of the rat contigs are aligned to multiple places in human and 97% of all alignments with human sequence > 100kb agree with a three-way synteny map built independently using predicted exons in the three genomes. At the nucleotide level <1% of the rat nucleotides are mapped to multiple places in the human sequence in the alignment; and 96.5% of human nucleotides within all alignments agree with the synteny map. The alignments are publicly available online, with visualization through the novel Multi-VISTA browser that we also present.
Date: July 4, 2004
Creator: Brudno, Michael; Poliakov, Alexander; Salamov, Asaf; Cooper, Gregory M.; Sidow, Arend; Rubin, Edward M. et al.
Object Type: Article
System: The UNT Digital Library
Aviation Safety: Better Management Controls are Needed to Improve FAA's Safety Enforcement and Compliance Efforts (open access)

Aviation Safety: Better Management Controls are Needed to Improve FAA's Safety Enforcement and Compliance Efforts

A letter report issued by the Government Accountability Office with an abstract that begins "The safety of the nation's flying public depends, in large part, on the aviation industry's compliance with safety regulations and the Federal Aviation Administration's (FAA) enforcement of those regulations when violations occur. FAA attempts to gain the industry's compliance through enforcement tools, including levying fines and suspending or revoking operating certificates, and partnership programs that allow participating companies or individuals to self-report violations of safety regulations and mitigate or avoid fines or other legal actions. GAO was asked to assess how FAA uses its enforcement options to address noncompliance and what management controls are in place to ensure that enforcement efforts and partnership programs result in compliance with aviation safety regulations."
Date: July 6, 2004
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Axial and Temporal Gradients in Mo Z Pinches (open access)

Axial and Temporal Gradients in Mo Z Pinches

Three nested molybdenum wire arrays with initial outer diameters of 45, 50, and 55 mm were imploded by the {approx} 20 MA, 90 ns rise-time current pulse of Sandia's Z accelerator. The implosions generated Mo plasmas with approximately 10% of the array's initial mass reaching Ne-like and nearby ionization stages. These ions emitted 2 - 4 keV L-shell x-rays with radiative powers approaching 10 TW. Mo L-shell spectra with axial and temporal resolution were captured and have been analyzed using a non-LTE collisional-radiative model. We find significant axial variation in the plasma conditions, with electron densities increasing from the cathode ({approx} 3 x 10{sup 20}cm{sup -3}) to near the anode end of the plasma ({approx} 3 x 10{sup 21}cm{sup -3}) and electron temperatures decreasing slightly from the cathode ({approx} 1.7 keV) to the anode end ({approx} 1.5 keV). Time-resolved spectra indicate that the peak electron density is reached before the peak of the L-shell emission and decreases with time, while the electron temperature remains within 10% of 1.7 keV over the 20 - 30 ns L-shell radiation pulse. Finally, while the total yield, peak total power, and peak L-shell power all tended to decrease with increasing initial wire array diameters, …
Date: July 14, 2004
Creator: LePell, P D; Hansen, S B; Shlyaptseva, A S; Coverdale, C; Deeney, C; Apruzese, J P et al.
Object Type: Article
System: The UNT Digital Library
Axisymmetric Tandem Mirrors: Stabilization and Confinement Studies (open access)

Axisymmetric Tandem Mirrors: Stabilization and Confinement Studies

The 'Kinetic Stabilizer' has been proposed as a means of MHD stabilizing an axisymmetric tandem mirror system. The K-S concept is based on theoretical studies by Ryutov, confirmed experimentally in the Gas Dynamic Trap experiment in Novosibirsk. In the K-S beams of ions are directed into the end of an 'expander' region outside the outer mirror of a tandem mirror. These ions, slowed, stagnated, and reflected as they move up the magnetic gradient, produce a low-density stabilizing plasma. At the Lawrence Livermore National Laboratory we have been conducting theoretical and computational studies of the K-S Tandem Mirror. These studies have employed a low-beta code written especially to analyze the beam injection/stabilization process, and a new code SYMTRAN (by Hua and Fowler) that solves the coupled radial and axial particle and energy transport in a K-S TM. Also, a 'legacy' MHD stability code, FLORA, has been upgraded and employed to benchmark the injection/stabilization code and to extend its results to high beta values. The FLORA code studies so far have confirmed the effectiveness of the K-S in stabilizing high-beta (40%) plasmas with stabilizer plasmas the peak pressures of which are several orders of magnitude smaller than those of the confined plasma. …
Date: July 15, 2004
Creator: Post, R F; Fowler, T K; Bulmer, R; Byers, J; Hua, D & Tung, L
Object Type: Article
System: The UNT Digital Library
B Physics at D0 (open access)

B Physics at D0

The Fermilab Tevatron (p{bar p}), operating at {radical}s = 1.96 TeV, is a rich source of B hadrons. The large acceptance in terms of rapidity and transverse momentum of the charged particle tracking system and the muon system make the upgraded Run II D0 detector an excellent tool for B physics. In this article, we report on selected physics results based on the first 250 pb{sup -1} of Run II data. This includes results on the X(3872) state, semileptonic B decays, B hadron lifetimes, flavour oscillations, and the rare decay B{sub s} {yields} {mu}{sup +}{mu}{sup -}.
Date: July 12, 2004
Creator: Stark, Jan
Object Type: Article
System: The UNT Digital Library
Babel Users' Guide (open access)

Babel Users' Guide

None
Date: July 26, 2004
Creator: Dahlgren, Tamara; Epperly, Thomas; Kumfert, Gary & Leek, James
Object Type: Text
System: The UNT Digital Library
Beam Conditioning and Harmonic Generation in Free ElectronLasers (open access)

Beam Conditioning and Harmonic Generation in Free ElectronLasers

The next generation of large-scale free-electron lasers (FELs) such as Euro-XFEL and LCLS are to be devices which produce coherent X-rays using Self-Amplified Spontaneous Emission (SASE). The performance of these devices is limited by the spread in longitudinal velocities of the beam. In the case where this spread arises primarily from large transverse oscillation amplitudes, beam conditioning can significantly enhance FEL performance. Future X-ray sources may also exploit harmonic generation starting from laser-seeded modulation. Preliminary analysis of such devices is discussed, based on a novel trial-function/variational-principle approach, which shows good agreement with more lengthy numerical simulations.
Date: July 5, 2004
Creator: Charman, A.E.; Penn, G.; Wolski, A. & Wurtele, J.S.
Object Type: Article
System: The UNT Digital Library
Beam manipulation and compression using broadband rf systems in the Fermilab Main Injector and Recycler (open access)

Beam manipulation and compression using broadband rf systems in the Fermilab Main Injector and Recycler

A novel method for beam manipulation, compression, and stacking using a broad band RF system in circular accelerators is described. The method uses a series of linear voltage ramps in combination with moving barrier pulses to azimuthally compress, expand, or cog the beam. Beam manipulations can be accomplished rapidly and, in principle, without emittance growth. The general principle of the method is discussed using beam dynamics simulations. Beam experiments in the Fermilab Recycler Ring convincingly validate the concept. Preliminary experiments in the Fermilab Main Injector to investigate its potential for merging two ''booster batches'' to produce high intensity proton beams for neutrino and antiproton production are described.
Date: July 9, 2004
Creator: al., G William Foster et
Object Type: Article
System: The UNT Digital Library
BEAM SCRUBBING FOR RHIC POLARIZED PROTON RUN. (open access)

BEAM SCRUBBING FOR RHIC POLARIZED PROTON RUN.

One of the intensity limiting factor of RHIC polarized proton beam is the electron cloud induced pressure rise. A beam scrubbing study shows that with a reasonable period of time of running high intensity 112-bunch proton beam, the pressure rise can be reduced, allowing higher beam intensity.
Date: July 5, 2004
Creator: ZHANG,S. Y. FISCHER,W. HUANG,H. ROSER,T.
Object Type: Article
System: The UNT Digital Library
Below-Cost Timber Sales: An Overview (open access)

Below-Cost Timber Sales: An Overview

This report provides an overview of the below-cost timber sales issue.
Date: July 21, 2004
Creator: Gorte, Ross W.
Object Type: Report
System: The UNT Digital Library
BigHorn Home Improvement Center: Proof that a Retail Building Can Be a Low Energy Building: Preprint (open access)

BigHorn Home Improvement Center: Proof that a Retail Building Can Be a Low Energy Building: Preprint

The BigHorn Home Improvement Center in Silverthorne, Colorado was one of the first commercial buildings in the United States to integrate extensive high-performance design into a retail space. After monitoring and evaluation by NREL, the BigHorn Center was found to consume 54% less source energy and have 53% lower energy costs than typical retail buildings of similar size. The extensive use of daylighting to replace electric lighting reduced lighting energy requirements by 80% and significantly contributed to the reduced energy loads in the building.
Date: July 1, 2004
Creator: Deru, M.; Torcellini, P. & Judkoff, R.
Object Type: Article
System: The UNT Digital Library
BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry (open access)

BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry

Better devices are needed for the detection of aerosolized biological warfare agents. Advances in the ongoing development of one such device, the BioAerosol Mass Spectrometry (BAMS) system, are described here in detail. The system samples individual, micrometer-sized particles directly from the air and analyzes them in real-time without sample preparation or use of reagents. At the core of the BAMS system is a dual-polarity, single-particle mass spectrometer with a laser based desorption and ionization (DI) system. The mass spectra produced by early proof-of-concept instruments were highly variable and contained limited information to differentiate certain types of similar biological particles. The investigation of this variability and subsequent changes to the DI laser system are described. The modifications have reduced the observed variability and thereby increased the usable information content in the spectra. These improvements would have little value without software to analyze and identify the mass spectra. Important improvements have been made to the algorithms that initially processed and analyzed the data. Single particles can be identified with an impressive level of accuracy, but to obtain significant reductions in the overall false alarm rate of the BAMS instrument, alarm decisions must be made dynamically on the basis of multiple analyzed particles. …
Date: July 20, 2004
Creator: Steele, P T
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Biodiesel Analytical Methods: August 2002--January 2004 (open access)

Biodiesel Analytical Methods: August 2002--January 2004

Biodiesel is an alternative fuel for diesel engines that is receiving great attention worldwide. The material contained in this book is intended to provide the reader with information about biodiesel engines and fuels, analytical methods used to measure fuel properties, and specifications for biodiesel quality control.
Date: July 1, 2004
Creator: Van Gerpen, J.; Shanks, B.; Pruszko, R.; Clements, D. & Knothe, G.
Object Type: Report
System: The UNT Digital Library
Biodiesel Production Technology: August 2002--January 2004 (open access)

Biodiesel Production Technology: August 2002--January 2004

Biodiesel is an alternative fuel for diesel engines that is gaining attention in the United States after reaching a considerable level of success in Europe. The purpose of this book is to describe and explain the process and issues involved in producing this fuel.
Date: July 1, 2004
Creator: Van Gerpen, J.; Shanks,B.; Pruszko,R.; Clements, D. & Knothe, G.
Object Type: Report
System: The UNT Digital Library
Bit-Error-Rate Performance of a Gigabit Ethernet O-CDMA Technology Demonstrator (TD) (open access)

Bit-Error-Rate Performance of a Gigabit Ethernet O-CDMA Technology Demonstrator (TD)

An O-CDMA TD based on 2-D (wavelength/time) codes is described, with bit-error-rate (BER) and eye-diagram measurements given for eight users. Simulations indicate that the TD can support 32 asynchronous users.
Date: July 9, 2004
Creator: Hernandez, V. J.; Mendez, A. J.; Bennett, C. V. & Lennon, W. J.
Object Type: Article
System: The UNT Digital Library