Collection
Office of Scientific & Technical Information Technical Reports
1,417
Texas Laws and Resolutions Archive
1,327
Congressional Research Service Reports
742
Defense Base Closure and Realignment Commission
337
Government Accountability Office Reports
273
Texas Attorney General Opinions
33
Texas Register
16
9/11 Commission Records
13
Texas State Publications
11
End of Term Publications
4
3 More
Country
States
4,176 Matching Results
Results open in a new window/tab.
Results:
1 - 24 of
4,176
next
School Library Programs: Standards and Guidelines for Texas
Manual/guide providing information/instructions about revisions to the standards and guidelines for school library programs, including the six major components of school library programs, strategies for librarians, output measures, and outcome-based evaluations.
Date:
March 19, 2004
Creator:
Texas State Library and Archives Commission. Archives and Information Services Division.
Object Type:
Book
System:
The Portal to Texas History
Why are the P{sub n} and S{sub n} Methods Equivalent
The author assumes that the reader is familiar with the Spherical harmonics, Pn, method and the discrete ordinates, S{sub n}, method; for a derivation of the equations used in these methods. I will only discuss the Boltzmann equation in one dimension, and the Sn method using Gaussian quadrature. I will do this merely to simplify the following discussion; once you understand the concepts presented here you can easily extend the conclusions to more general situations. Why are the spherical harmonics P{sub n} and discrete ordinate S{sub n} methods, or more correctly the P{sub n} and S{sub n+1} methods, equivalent, e.g., P{sub 3} is equivalent to S{sub 4}? When the S{sub n} method uses a Gaussian quadrature most textbooks will tell you that both methods are equivalent to assuming that the angular flux can be represented by a Legendre polynomial expansion of order n. Most textbooks are wrong [1]. We know that the S{sub n} method constrains the ''particles'' to travel in discrete directions; when Gaussian quadrature is used these discrete directions correspond to the zeros of the Legendre polynomial P{sub n+1}({mu}). What is not immediately obvious is that the P{sub n} method constrains the ''particles'' in exactly the same way. …
Date:
September 19, 2001
Creator:
Cullen, D E
Object Type:
Report
System:
The UNT Digital Library
Horizontal and Slant-Path Surveillance with Speckle Imaging
A fundamental problem in providing high-quality surveillance images recorded over long horizontal or slant paths is the blurring caused by atmospheric turbulence, which reduces both the resolution and contrast. The objective of the work reported here is to develop a capability for long-range imaging through the atmosphere that is not limited by the atmosphere but only by the fundamental diffraction limit of the optics. This paper describes our recent horizontal and slant-path imaging experiments of point targets and extended scenes as well as simulations of point targets in comparison to experiment. We show the near-diffraction limited resolution results obtained using bispectral speckle-imaging techniques. The experiments were performed with an 8-inch diameter telescope placed either in a field, on a rooftop, or on a hillside and cover ranges of interest from 100 meters up to 10 km. The scenery includes resolution targets, people, vehicles, and other structures.
Date:
August 19, 2002
Creator:
Carrano, C J & Brase, J M
Object Type:
Article
System:
The UNT Digital Library
A Dynamically Adaptive Arbitrary Lagrangian-Eulerian Method for Hydrodynamics
A new method that combines staggered grid Arbitrary Lagrangian-Eulerian (ALE) techniques with structured local adaptive mesh refinement (AMR) has been developed for solution of the Euler equations. The novel components of the combined ALE-AMR method hinge upon the integration of traditional AMR techniques with both staggered grid Lagrangian operators as well as elliptic relaxation operators on moving, deforming mesh hierarchies. Numerical examples demonstrate the utility of the method in performing detailed three-dimensional shock-driven instability calculations.
Date:
October 19, 2002
Creator:
Anderson, R W; Pember, R B & Elliott, N S
Object Type:
Article
System:
The UNT Digital Library
Activation of the mercury laser: a diode-pumped solid-state laser driver for inertial fusion
Initial measurements are reported for the Mercury laser system, a scalable driver for rep-rated high energy density physics research. The performance goals include 10% electrical efficiency at 10 Hz and 100 J with a 2-10 ns pulse length.
Date:
September 19, 2000
Creator:
Bayramian, A. J.; Bibeau, C.; Beach, R. J.; Ebbers, C. A.; Kanz, K.; Nakano, H. et al.
Object Type:
Article
System:
The UNT Digital Library
Optical, UV, and EUV Oscillations of SS Cygni in Outburst
I provide a review of observations in the optical, UV (HST), and EUV (EUVE and Chandra LETG) of the rapid periodic oscillations of nonmagnetic, disk-accreting, high mass-accretion rate cataclysmic variables (CVs), with particular emphasis on the dwarf nova SS Cyg in outburst. In addition, I drawn attention to a correlation, valid over nearly six orders of magnitude in frequency, between the frequencies of the quasi-periodic oscillations (QPOs) of white dwarf, neutron star, and black hole binaries. This correlation identifies the high frequency quasi-coherent oscillations (so-called ''dwarf nova oscillations'') of CVs with the kilohertz QPOs of low mass X-ray binaries (LMXBs), and the low frequency and low coherence QPOs of CVs with the horizontal branch oscillations (or the broad noise component identified as such) of LMXBs. Assuming that the same mechanisms produce the QPOs of white dwarf, neutron star, and black hole binaries, this correlation has important implications for QPO models.
Date:
December 19, 2003
Creator:
Mauche, C W
Object Type:
Article
System:
The UNT Digital Library
Flame Inhibition by Phosphorus-Containing Compounds in Lean and Rich Propane Flames
Chemical inhibition of laminar propane flames by organophosphorus compounds has been studied experimentally, using a laboratory Mache Hebra nozzle burner and a flat flame burner with molecular beam mass spectrometry (MBMS), and with a computational flame model using a detailed chemical kinetic reaction mechanism. Both fuel-lean and fuel-rich propane flames were studied to examine the role of equivalence ratio in flame inhibition. The experiments examined a wide variety of organophosphorus compounds. We report on the experimental species flame profiles for tri-methyl phosphate (TMP) and compare them with the species flame profile results from modeling of TMP and di-methyl methyl phosphonate (DMMP). Both the experiments and kinetic modeling support and illustrate previous experimental studies in both premixed and non-premixed flames that inhibition efficiency is effectively the same for all of the organophosphorus compounds examined, independent of the molecular structure of the initial inhibitor molecule. The chemical inhibition is due to reactions involving the small P-bearing species HOPO{sub 2} and HOPO that are produced by the organophosphorus compounds (OPCs). The ratios of the HOPO{sub 2} and HOPO concentrations differ between the lean and rich flames, with HOPO{sub 2} dominant in lean flames while HOPO dominates in rich flames. The resulting HOPO{sub 2} …
Date:
December 19, 2003
Creator:
Curran, H; Korobeinichev, O P; Shvartsberg, V M; Shmakov, A G; Bolshova, T A; Jayaweera, T M et al.
Object Type:
Article
System:
The UNT Digital Library
A Detailed Modeling Study of Propane Oxidation
A detailed chemical kinetic mechanism has been used to simulate ignition delay times recorded by a number of experimental shock tube studies over the temperature range 900 {le} T {le} 1800 K, in the pressure range 0.75-40 atm and in the equivalence ratio range 0.5 {le} {phi} {le} 2.0. Flame speed measurements at 1 atm in the equivalence ratio range 0.4 {le} {phi} {le} 1.8 have also been simulated. Both of these data sets, particularly those recorded at high pressure, are of particular importance in validating a kinetic mechanism, as internal combustion engines operate at elevated pressures and temperatures and rates of fuel oxidation are critical to efficient system operation. Experiments in which reactant, intermediate and product species were quantitatively recorded, versus temperature in a jet-stirred reactor (JSR) and versus time in a flow reactor are also simulated. This data provide a stringent test of the kinetic mechanism as it must reproduce accurate quantitative profiles for all reactant, intermediate and product species. The JSR experiments were performed in the temperature range 1000-1110 K, in the equivalence ratio range 0.5 {le} {phi} {le} 4.0, at a pressure of 5 atm. These experiments are complemented by those carried out in a flow …
Date:
March 19, 2004
Creator:
Westbrook, C. K.; Jayaweera, T. M.; Pitz, W. J. & Curran, H. J.
Object Type:
Article
System:
The UNT Digital Library
The raw disk i/o performance of compaq storage works RAID arrays under tru64 unix
We report on the raw disk i/o performance of a set of Compaq StorageWorks RAID arrays connected to our cluster of Compaq ES40 computers via Fibre Channel. The best cumulative peak sustained data rate is l17MB/s per node for reads and 77MB/s per node for writes. This value occurs for a configuration in which a node has two Fibre Channel interfaces to a switch, which in turn has two connections to each of two Compaq StorageWorks RAID arrays. Each RAID array has two HSG80 RAID controllers controlling (together) two 5+p RAID chains. A 10% more space efficient arrangement using a single 1l+p RAID chain in place of the two 5+P chains is 25% slower for reads and 40% slower for writes.
Date:
October 19, 2000
Creator:
Uselton, A C
Object Type:
Report
System:
The UNT Digital Library
Investigation of the Electronic Structure of Solid Density Plasmas by X-Ray Scattering
We present an improved analytical expression for the x-ray dynamic structure factor from a dense plasma which includes the effects of weakly bound electrons. This result can be applied to describe scattering from low to moderate Z plasmas, and it covers the entire range of plasma conditions that can be found in inertial confinement fusion experiments, from ideal to degenerate up to moderately coupled systems. We use our theory to interpret x-ray scattering experiments from solid density carbon plasma and to extract accurate measurements of electron temperature, electron density and charge state. We use our experimental results to validate various equation-of-state models for carbon plasmas.
Date:
May 19, 2003
Creator:
Gregori, G; Glenzer, S H; Forest, F J; Kuhlbrodt, S; Redmer, R; Faussurier, G et al.
Object Type:
Report
System:
The UNT Digital Library
Biodefense to Cancer Office- Meeting Transcirpt
None
Date:
April 19, 2004
Creator:
Felton, J S; Matthews, D L & Lane, S M
Object Type:
Article
System:
The UNT Digital Library
NEUTRINO SCATTERING IN PERTURBATIVE QCD AND IMPLICATIONS FOR THE WEINBERG ANGLE.
We summarize a recent calculation of perturbative neutrino cross sections that includes NLO and mass corrections. We provide numerical results for quantities that are related to the extraction of the weak mixing angle from neutrino deep inelastic scattering.
Date:
May 19, 2003
Creator:
KRETZER,S. HALL-RENO,M.
Object Type:
Article
System:
The UNT Digital Library
Qualification Tests for the New Air Sampling System at the 296-Z-1 Stack
This report documents tests performed by Pacific Northwest National Laboratory to verify that the new air monitoring system for the 296-Z-1 ventilation exhaust stack meets the applicable regulatory criteria regarding the placement of the air sampling probe, sample transport, and stack flow measurement accuracy. These criteria ensure that the contaminants in the stack are well mixed with the airflow at the location of the probe so that the collected sample represents the whole. The sequence of tests addresses the acceptability of the flow angle relative to the probe uniformity of air velocity and gaseous and particle tracers in the cross section of the stack delivery of the sample from the sampler nozzle to the collection filter. The tests conducted on the air monitoring system demonstrated that the location for the air-sampling probe meets all performance criteria for air sampling systems at nuclear facilities. The performance criterion for particle transport was also met. All tests were successful, and all acceptance criteria were met.
Date:
September 19, 2002
Creator:
Glissmeyer, John A.; Maughan, A D. & Jarvis, Timothy T.
Object Type:
Report
System:
The UNT Digital Library
Effects of the Electron Energy Distribution Function on Modeled X-ray Spectra
This paper presents the results of a broad investigation into the effects of the electron energy distribution function on the predictions of non-LTE collisional-radiative atomic kinetics models. The effects of non-Maxwellian and suprathermal (''hot'') electron distributions on collisional rates (including three-body recombination) are studied. It is shown that most collisional rates are fairly insensitive to the functional form and characteristic energy of the electron distribution function as long as the characteristic energy is larger than the threshold energy for the collisional process. Collisional excitation and ionization rates, however, are highly sensitive to the fraction of hot electrons. This permits the development of robust spectroscopic diagnostics that can be used to characterize the electron density, bulk electron temperature, and hot electron fraction of plasmas with non-equilibrium electron distribution functions (EDFs). Hot electrons are shown to increase and spread out plasma charge state distributions, amplify the intensities of emission lines fed by direct collisional excitation and radiative cascades, and alter the structure of satellite features in both K- and L-shell spectra. The characteristic energy, functional form, and spatial properties of hot electron distributions in plasmas are open to characterization through their effects on high-energy continuum and line emission and on the polarization …
Date:
February 19, 2004
Creator:
Shlyaptseva, A S & Hansen, S B
Object Type:
Article
System:
The UNT Digital Library
Modeling Electron Cloud Effects in Heavy Ion Accelerators
None
Date:
April 19, 2004
Creator:
Cohen, R; Azevedo, A; Friedman, A; Furman, M; Lund, S; Molvik, A et al.
Object Type:
Article
System:
The UNT Digital Library
Long Period Variables in the LMC: Results from MACHO and 2Mass
We use the eight year light curve database from the MACHO (MAssive Compact Halo Objects) project together with infrared colors and magnitudes from 2MASS (the Two Micron All Sky Survey) to identify a sample of 22,000 long period variables in the Large Magellanic Cloud (referred to hereafter as LMC LPVs). A period luminosity diagram of these stars reveals six well defined sequences, in substantial agreement with previous analyses of samples from OGLE (Optical Gravitational Lensing Experiment). In our analysis we identify analogues to galactic LPVs in the LMC LPV sample. We find that carbon dominated AGB stars populate only two of the sequences, one of which includes the Mira variables. The high luminosity end of the same two sequences are also the location of the only stars with J K{sub s} > 2, indicating that they are enshrouded in dust. The unknown mechanism that produces the variability of the last sequence--those stars with long secondary periods--produces different morphology in the period luminosity diagram than what is seen in the first four sequences, which are thought to be caused by pulsation. In particular, the last sequence extends to lower luminosity RGB stars and the luminosity function does not peak among the …
Date:
July 19, 2004
Creator:
Fraser, O J; Cook, K H; Keller, S C & Hawley, S L
Object Type:
Article
System:
The UNT Digital Library
Electronic excitations and chemistry in Nitromethane and HMX
The nature of electronic excitations in crystalline solid nitromethane under conditions of shock loading and static compression are examined. Density functional theory calculations are used to determine the crystal bandgap under hydrostatic stress, uniaxial strain, and shear strain. Bandgap lowering under uniaxial strain due to molecular defects and vacancies is considered. In all cases, the bandgap is not lowered enough to produce a significant population of excited states in the crystal. Preliminary simulations on the formation of detonation product molecules from HMX are discussed.
Date:
June 19, 2001
Creator:
Reed, E J; Manaa, M R; Joannopoulos, J D & Fried, L E
Object Type:
Article
System:
The UNT Digital Library
Review of Astrophysics Experiments on Intense Lasers
Astrophysics has traditionally been pursued at astronomical observatories and on theorists' computers. Observations record images from space, and theoretical models are developed to explain the observations. A component often missing has been the ability to test theories and models in an experimental setting where the initial and final states are well characterized. Intense lasers are now being used to recreate aspects of astrophysical phenomena in the laboratory, allowing the creation of experimental testbeds where theory and modeling can be quantitatively tested against data. We describe here several areas of astrophysics--supernovae, supernova remnants, gamma-ray bursts, and giant planets--where laser experiments are under development to test our understanding of these phenomena.
Date:
January 19, 2000
Creator:
Remington, B. A.; Drake, R. P.; Takabe, H. & Arnett, D.
Object Type:
Article
System:
The UNT Digital Library
FY05-FY06 Advanced Simulation and Computing Implementation Plan, Volume 2
The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program will require the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear weapon design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable stockpile life extension programs and the resolution of significant finding investigations (SFIs). This requires a balanced system of technical staff, hardware, simulation software, and computer science solutions.
Date:
July 19, 2004
Creator:
Baron, A. L.
Object Type:
Report
System:
The UNT Digital Library
FRMAC Health and Safety Working Group Update
None
Date:
April 19, 2004
Creator:
Hadley, R T
Object Type:
Article
System:
The UNT Digital Library
EXAMINING CONCEPT OF OPERATIONS IN FUTURE PLANTS.
This paper will examine the results of this research that focus on future concepts of operations. Our approach was to look at current technological developments in the areas of reactor technology, I&C technology, and human-system integration technology and to make projections into the near and longer-term future concerning their potential impact on human performance. The results were discussed in terms of three aspects of concepts of operations: functional staffing models, plant automation, and training and qualifications. Significant changes to each are anticipated and discussed. Research will be needed to address these changes in order to provide for confidence that changes to concepts of operations are accomplished in ways that maintain public safety.
Date:
September 19, 2004
Creator:
O'HARA,J. M. HIGGINS,J. BROWN,W. KRAMER,J. PERSENSKY,J.
Object Type:
Article
System:
The UNT Digital Library
Electron Clouds and Vacuum Pressure Rise in RHIC.
The luminosity in RHIC is limited by vacuum pressure rises, observed with high intensity beams of all species (Au{sup 79+}, d{sup +}, p{sup +}). At injection, the pressure rise could be linked to the existence of electron clouds. In addition, pressure rises in the experimental regions may be caused by electron clouds. They review the existing observations, comparisons with simulations, as well as corrective measures taken and planned.
Date:
April 19, 2004
Creator:
Fischer, W.; Blaskiewicz, M.; He, P.; Huang, H.; Hseuh, H. C.; Iriso, U. et al.
Object Type:
Article
System:
The UNT Digital Library
An Approach to Estimate the Localized Effects of an Aircraft Crash on a Facility
Aircraft crashes are an element of external events required to be analyzed and documented in facility Safety Analysis Reports (SARs) and Nuclear Explosive Safety Studies (NESSs). This paper discusses the localized effects of an aircraft crash impact into the Device Assembly Facility (DAF) located at the Nevada Test Site (NTS), given that the aircraft hits the facility. This was done to gain insight into the robustness of the DAF and to account for the special features of the DAF that enhance its ability to absorb the effects of an aircraft crash. For the purpose of this paper, localized effects are considered to be only perforation or scabbing of the facility. This paper presents an extension to the aircraft crash risk methodology of Department of Energy (DOE) Standard 3014. This extension applies to facilities that may find it necessary or desirable to estimate the localized effects of an aircraft crash hit on a facility of nonuniform construction or one that is shielded in certain directions by surrounding terrain or buildings. This extension is not proposed as a replacement to the aircraft crash risk methodology of DOE Standard 3014 but rather as an alternate method to cover situations that were not considered.
Date:
April 19, 2004
Creator:
Kimura, C; Sanzo, D & Sharirli, M
Object Type:
Article
System:
The UNT Digital Library
Science To Support DOE Site Cleanup: The Pacific Northwest National Laboratory Environmental Management Science Program Awards
Pacific Northwest National Laboratory (PNNL) was awarded ten Environmental Management Science Program (EMSP) research grants in fiscal year 1996, six in fiscal year 1997, nine in fiscal year 1998, seven in fiscal year 1999, and five in fiscal year 2000. All of the fiscal year 1996 award projects have published final reports. The 1997 and 1998 award projects have been completed or are nearing completion. Final reports for these awards will be published, so their annual updates will not be included in this document. This section summarizes how each of the 1999 and 2000 grants address significant U.S. Department of Energy (DOE) cleanup issues, including those at the Hanford Site. The technical progress made to date in each of these research projects is addressed in more detail in the individual progress reports contained in this document. The 1999 and 2000 EMSP awards at PNNL are focused primarily in two areas: Tank Waste Remediation, and Soil and Groundwater Cleanup.
Date:
June 19, 2001
Creator:
Bredt, Paul R.; Brockman, Fred J.; Camaioni, Donald M.; Felmy, Andrew R.; Grate, Jay W.; Hay, Benjamin P. et al.
Object Type:
Report
System:
The UNT Digital Library