States

Implementation of the Contract Leverage Team (CLT) Report (open access)

Implementation of the Contract Leverage Team (CLT) Report

Summary sheet describing the findings of an internal audit by the Texas Department of Health regarding the Contract Leverage Team (CLT), including findings and recommendations.
Date: March 6, 2000
Creator: Texas. Department of Health.
Object Type: Report
System: The Portal to Texas History
Low-Temperature Growth of DKDP for Improving Laser-Induced Damage resistance at 350nm (open access)

Low-Temperature Growth of DKDP for Improving Laser-Induced Damage resistance at 350nm

A set of twenty-three 20-L crystallizer runs exploring the importance of several engineering variables found that growth temperature is the most important variable controlling damage resistance of DKDP over the conditions investigated. Boules grown between 45 C and room temperature have a 50% probability of 3{omega} bulk damage that is 1.5 to 2 times higher than boules grown between 65 and 45 C. This raises their damage resistance above the NIF tripler specification for 8 J/cm{sup 2} operation by a comfortable margin. Solution impurity levels do not correlate with damage resistance for iron less than 200 ppb and aluminum less than 2000 ppb. The possibility that low growth temperatures could increase damage resistance in NIF-scale boules was tested by growing a large boule in a 1000-L crystallizer with a supplemental growth solution tank. Four samples representing early and late pyramid and prism growth are very close to the specification as best it is understood at the present. Implications of low temperature growth for meeting absorbance, homogeneity, and other material specifications are discussed.
Date: December 6, 2000
Creator: Burnham, A K; Runkel, M; Hawley-Fedder, R A; Carman, M L; Torres, R A & Whitman, P K
Object Type: Article
System: The UNT Digital Library
Ion storage ring measurements of dielectronic recombination for astrophysically relevant Feq+ ions (open access)

Ion storage ring measurements of dielectronic recombination for astrophysically relevant Feq+ ions

Iron ions provide many valuable plasma diagnostics for cosmic plasmas. The accuracy of these diagnostics, however, often depends on an accurate understanding of the ionization structure of the emitting gas. Dielectronic recombination (DR) is the dominant electron-ion recombination mechanism for most iron ions in cosmic plasmas. Using the heavy-ion storage ring at the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany, we have measured the low temperature DR rates for Fe{sup q+} where q = 15, 17, 18, and 19. These rates are important for photoionized gases which form in the media surrounding active galactic nuclei, X-ray binaries, and cataclysmic variables. Our results demonstrate that commonly used theoretical approximations for calculating low temperature DR rates can easily under- or over-estimate the DR rate by a factor of {approx} 2 or more. As essentially all DR rates used for modeling photoionized gases are calculated using these approximations, our results indicate that new DR rates are needed for almost all charge states of cosmically abundant elements. Measurements are underway for other charge states of iron.
Date: June 6, 2000
Creator: Savin, D. W.; Badnell, N. R.; Bartsch, T.; Brandau, C.; Chen, M. H.; Grieser, M. et al.
Object Type: Article
System: The UNT Digital Library
Testing and Analysis of Consolidated Sludge Samples from the 105 K East Basin Floor and Canisters (open access)

Testing and Analysis of Consolidated Sludge Samples from the 105 K East Basin Floor and Canisters

The testing reported here was performed on K East Basin consolidated sludge samples to generate data needed for the evaluation and design of the systems that will be used to disposition the K Basin sludge to T-Plant for interim storage. The tests were conducted by Pacific Northwest National Laboratory from May through November 1999 under the direction of the Spent Nuclear Fuel (SNF) Project. The samples used in the work discussed here were collected by the SNF Characterization Project from the KE Basin floor and canisters during March and April 1999. These samples (3 from the floor and 3 from the canisters) were shipped to the storage pool at the Postirradiation Testing Laboratory (327 Building) and later transferred to the PNNL Radiochemical Processing Laboratory (325 Building), where they were recovered for testing and analysis. Testing activities presented in this report include particle size measurement via wet sieving, sludge settling and sludge density measurements, sludge shear strength measurement, and measurement of sludge dissolution enthalpy to ascertain the uranium metal content of the sludge. Section 1.0 provides the summary and conclusions to date. Section 2.0 describes the consolidated sample container system, the sample collection and transfer, inspection, and recovery of the samples …
Date: November 6, 2000
Creator: Bredt, Paul R. (BATTELLE (PACIFIC NW LAB)); Delegard, Calvin H. (BATTELLE (PACIFIC NW LAB)); Schmidt, Andrew J. (BATTELLE (PACIFIC NW LAB)) & Silvers, Kurt L. (BATTELLE (PACIFIC NW LAB))
Object Type: Report
System: The UNT Digital Library
Characterization of Thermal Sprayed Aluminum and Stainless Steel Coatings for Clean Laser Enclosures (open access)

Characterization of Thermal Sprayed Aluminum and Stainless Steel Coatings for Clean Laser Enclosures

Surfaces of steel structures that enclose high-fluence, large-beam lasers have conventional and unconventional requirements. Aside from rust prevention, the surfaces must resist laser-induced degradation and the contamination of the optical components. The latter requires a surface that can be precision cleaned to low levels of particulate and organic residue. In addition, the surface treatment for the walls should be economical to apply because of the large surface areas involved, and accommodating with intricate joint geometries. Thermal sprayed coatings of aluminum (Al) and stainless steel are candidate surface materials. Coatings are produced and characterized for porosity, smoothness, and hardness. These properties have a bearing on the cleanliness of the coating. The laser resistance of Al and 3 16L coatings are given. The paper summarizes the characterization of twin-wire-arc deposited Al, high-velocity-oxygen-fueled (HVOF) deposited Al, flame-sprayed 316L, and HVOF deposited316L. The most promising candidate coating is that of HVOF Al. This Al coating has the lowest porosity (8%) compared the other three coatings and relatively low hardness (100 VHN). The as-deposited roughness (Ra) is 433 pinches, but after a quick sanding by hand, the roughness decreased to 166 pinches. Other post-coat treatments are discussed. HVOF aluminum coatings are demonstrated. Al coatings are …
Date: April 6, 2000
Creator: Chow, R; Decker, T A; Gansert, R V & Gansert, D
Object Type: Article
System: The UNT Digital Library
Dataflow and remapping for wavelet compression and realtime view-dependent optimization of billion-triangle isosurfaces (open access)

Dataflow and remapping for wavelet compression and realtime view-dependent optimization of billion-triangle isosurfaces

Currently, large physics simulations produce 3D fields whose individual surfaces, after conventional extraction processes, contain upwards of hundreds of millions of triangles. Detailed interactive viewing of these surfaces requires powerful compression to minimize storage, and fast view-dependent optimization of display triangulations to drive high-performance graphics hardware. In this work we provide an overview of an end-to-end multiresolution dataflow strategy whose goal is to increase efficiencies in practice by several orders of magnitude. Given recent advancements in subdivision-surface wavelet compression and view-dependent optimization, we present algorithms here that provide the ''glue'' that makes this strategy hold together. Shrink-wrapping converts highly detailed unstructured surfaces of arbitrary topology to the semi-structured form needed for wavelet compression. Remapping to triangle bintrees minimizes disturbing ''pops'' during real-time display-triangulation optimization and provides effective selective-transmission compression for out-of-core and remote access to these huge surfaces.
Date: October 6, 2000
Creator: Duchaineau, M A; Porumbescu, S D; Bertram, M; Hamann, B & Joy, K I
Object Type: Article
System: The UNT Digital Library
Intercomparison of present and future climates simulated by coupled ocean-atmosphere GCMs (open access)

Intercomparison of present and future climates simulated by coupled ocean-atmosphere GCMs

We present an overview of results from the most recent phase of the Coupled Model Intercomparison Project (CMIP). This phase of CMIP has archived output from both unforced (''control run'') and perturbed (1% per year increasing atmospheric carbon dioxide) simulations by 15 modern coupled ocean-atmosphere general circulation models. The models are about equally divided between those employing and those not employing ad hoc flux corrections at the ocean-atmosphere interface. The new generation of non-flux-connected control runs are nearly as stable and agree with observations nearly as well as the flux-corrected models. This development represents significant progress in the state of the art of climate modeling since the Second (1995) Scientific Assessment Report of the Intergovernmental Panel on Climate Change (IPCC; see Gates et al. 1996). From the increasing-CO{sub 2} runs, we find that differences between different models, while substantial, are not as great as would be expected from earlier assessments that relied on equilibrium climate sensitivity.
Date: September 6, 2000
Creator: Covey, C; AchutaRao, K M & Lambert, S J
Object Type: Report
System: The UNT Digital Library
Research on parallel adaptive finite element methods (open access)

Research on parallel adaptive finite element methods

In this project we studied several fundamental issues arising in the parallel adaptive solution of linear and nonlinear elliptic and parabolic PDEs using multilevel algorithms. We focused our attention on a new approach described in the paper ''A New Paradigm for Parallel Adaptive Mesh Refinement'' by Bank and Hoist. The new approach requires almost no communication to solve an elliptic equation in parallel, and therefore has the potential to scale much more efficiently on massively parallel computers than do more traditional algorithms. The algorithm described in the Bank and Hoist paper has an inherently multilevel structure, in that a sequence of problems on a refinement hierarchy of meshes is solved during the course of the calculation. In particular, the algorithm has three main components: (1) We solve a small problem on a coarse mesh, and use a posteriori error estimates to partition the mesh. (2) Each processor is provided the complete coarse mesh and instructed to solve the entire problem, but with its adaptive refinement largely limited to its own assigned mesh partition. (3) A final mesh is computed using the union of the refined partitions provided by each processor. The mesh is regularized into a global conformal mesh, and …
Date: November 6, 2000
Creator: Holst, M.
Object Type: Report
System: The UNT Digital Library
Spectral-element agglomerate coarsening in AMGe (open access)

Spectral-element agglomerate coarsening in AMGe

In this talk the authors present a highly accurate coarsening algorithm for constructing coarse finite element spaces to be used in algebraic multigrid methods designed for finite element problems on generally unstructured meshes. The new algorithm relies on removing certain percentage of the high oscillating components from the spectrum of local stiffness matrices corresponding to element agglomerations. By doing so, one is guaranteed that the hierarchical complement finite element subspace gives rise to a well conditioned matrix. The coarsening consists of an agglomeration step and of computing a few minimal eigenvectors of the corresponding assembled agglomerate stiffness matrix. The method requires access to the individual element matrices. Based on the topological agglomeration algorithms they employed one is able to define coarse elements and coarse element matrices thus allowing for recursive use of the same algorithm. Some numerical illustration for elliptic problems is also given.
Date: December 6, 2000
Creator: Vassilevski, P S
Object Type: Article
System: The UNT Digital Library
Compilation and Integration of K Basin Sludge Particle Size Analysis Data (open access)

Compilation and Integration of K Basin Sludge Particle Size Analysis Data

This report consolidates and integrates all of the particle size analysis data generated during the Hanford K Basin sludge characterization campaigns. The provides the most representative particle size distribution curves for the various K Basin sludge types. Understanding the particle size distribution of the sludge is necessary to design sludge retrieval and processing systems and to address sludge transportation and storage safety issues due to the potential reactivity of sludge.
Date: November 6, 2000
Creator: Bredt, Paul R.; Tingey, Joel M. & Schmidt, Andrew J.
Object Type: Report
System: The UNT Digital Library
Germanium based coded aperture gamma-ray imager (open access)

Germanium based coded aperture gamma-ray imager

The advantages of spectrally resolved gamma-ray imaging have previously been demonstrated for the detection of fissile materials. However, previous results have been obtained with the relatively poor spectral resolution provided by scintillator-based detectors. In this paper we present a new class of coded aperture imager based on a position-sensitive germanium detector. The use of this detector type provides a factor of 40 improvement in energy resolution which improves the quality of the images obtained while reducing the integration time required. Tight spectral cuts on known emission lines allow deeper penetration into highly attenuating objects. In addition, advanced analysis techniques can provide information on overlying material though the application of spatially resolved gamma-gauging. We describe the imager, present simulations of its capabilities and the first characterizations of a prototype detector.
Date: July 6, 2000
Creator: Ziock, K P; Pohl, B; Schmid, G; Cork, C; Hull, E; Luke, P et al.
Object Type: Article
System: The UNT Digital Library
The 235U(n,2n(gamma)) Yrast Partial Gamma-Ray Cross Sections: A Report on the 1998 -- 1999 GEANIE Data and Analysis Techniques Appendix (open access)

The 235U(n,2n(gamma)) Yrast Partial Gamma-Ray Cross Sections: A Report on the 1998 -- 1999 GEANIE Data and Analysis Techniques Appendix

None
Date: September 6, 2000
Creator: Younes, W.; Becker, J. A.; Bernstein, L A; Garrett, P. E.; McGrath, C. A.; McNabb, D. P. et al.
Object Type: Report
System: The UNT Digital Library
X-ray Sources Generated from Gas-Filled Laser-Heated Targets (open access)

X-ray Sources Generated from Gas-Filled Laser-Heated Targets

The X-ray sources in the 4-7 keV energy regime can be produced by laser-irradiating high-Z gas-filled targets with high-powered lasers. A series of experiments have been performed using underdense targets that are supersonically heated with {approx} 35 W of 0.35 {micro}m laser light. These targets were cylindrical Be enclosures that were filled with 1-2 atms of Xe gas. L-shell x-ray emission is emitted from the plasma and detected by Bragg crystal spectrometers and x-ray diodes. Absolute flux measurements show conversion efficiencies of {approx} 10% in the multi-kilovolt x-ray emission. These sources can be used as bright x-ray backlighters or for material testing.
Date: June 6, 2000
Creator: Back, C. A.; Grun, J.; Decker, C. D.; Davis, J.; Laming, J. M.; Feldman, U. et al.
Object Type: Article
System: The UNT Digital Library
Algebraic coarsening methods for linear and nonlinear PDE and systems (open access)

Algebraic coarsening methods for linear and nonlinear PDE and systems

In [l] Brandt describes a general approach for algebraic coarsening. Given fine-grid equations and a prescribed relaxation method, an approach is presented for defining both the coarse-grid variables and the coarse-grid equations corresponding to these variables. Although, these two tasks are not necessarily related (and, indeed, are often performed independently and with distinct techniques) in the approaches of [1] both revolve around the same underlying observation. To determine whether a given set of coarse-grid variables is appropriate it is suggested that one should employ compatible relaxation. This is a generalization of so-called F-relaxation (e.g., [2]). Suppose that the coarse-grid variables are defined as a subset of the fine-grid variables. Then, F-relaxation simply means relaxing only the F-variables (i.e., fine-grid variables that do not correspond to coarse-grid variables), while leaving the remaining fine-grid variables (C-variables) unchanged. The generalization of compatible relaxation is in allowing the coarse-grid variables to be defined differently, say as linear combinations of fine-grid variables, or even nondeterministically (see examples in [1]). For the present summary it suffices to consider the simple case. The central observation regarding the set of coarse-grid variables is the following [1]: Observation 1--A general measure for the quality of the set of coarse-grid …
Date: November 6, 2000
Creator: McWilliams, J C
Object Type: Report
System: The UNT Digital Library
Charged particle and neutron backgrounds in an e-e- interaction region at the NLC (open access)

Charged particle and neutron backgrounds in an e-e- interaction region at the NLC

We compare the detector background situation in an e{sup -} e{sup -} interaction region at the NLC with previous studies done of the NLC e{sup +} e{sup -} interaction region. We note from previous studies that the dominant source of detector backgrounds are the beamstrahlung pairs. Since these scale with luminosity, the reduction in luminosity in e{sup -} e{sup -} collisions leads to a reduction in detector backgrounds compared to the e{sup +} e{sup -} situation.
Date: March 6, 2000
Creator: Gronberg, J
Object Type: Article
System: The UNT Digital Library
Direct Energy Exchange Enhancement in Distributed Injection Light Gas Launchers (open access)

Direct Energy Exchange Enhancement in Distributed Injection Light Gas Launchers

It is not widely acknowledged or appreciated that conventional, two-stage light-gas launchers do not efficiently apply their high breech pressures to the design intent: accelerating the projectile. Our objective in this project was to carry out the analysis, design, construction, and testing of a new class of launchers that will address this limitation. Our particular application is to expand the pressure range of the conventional, two-stage gas launcher to overlap and validate the pressure regimes previously attainable only with shock waves generated by nuclear explosions, lasers, or multistage conventional explosions. That is, these launchers would have the capability to conduct--in a laboratory setting--high-velocity-impact, equation-of-state (EOS) measurements at up to 2-TPa (20 Mbar) pressure levels in high-Z materials. Our design entailed a new class of distributed-injection, gas-dynamic launchers that are designed to use a boat-tail projectile to overcome the fundamental gas-expansion phenomena known as escape velocity (the Riemann limit). Our program included analytical, numerical, and experimental studies of the fast gas release flow technique that is central to the success of our approach. The analyses led us to believe that, in a typical configuration, the pressure will be effectively applied to the projectile in a time short relative to its few-microsecond …
Date: April 6, 2000
Creator: Alger, T W; Finucane, R G; Hall, J P; Penetrante, B M & Uphaus, T M
Object Type: Report
System: The UNT Digital Library
Limiting the Accidental Pressure Drop in NIF Beam Tubes (open access)

Limiting the Accidental Pressure Drop in NIF Beam Tubes

This report summarizes the use of a one-dimensional model of a time-dependent compressible flow condition to validate the results from a more sophisticated three-dimensional model. The flow conditions consist of the sudden decompression of a pressurized tube joined to an evacuated sphere, where the tube also has a leak to external atmosphere that is triggered open at a given pressure difference below sea-level pressure. This flow model is used to calculate conditions in a NIF beam tube if an internal vacuum barrier fails, and to calculate how the size and timing of an opening to external atmosphere changes tube pressure. Decompression of a NIF beam tube is a potential safety hazard since the tube could collapse if the tube pressure is reduced below the buckling limit. To prevent this from occurring, each pressurized section includes a rupture panel which is designed to open to external atmosphere at a given pressure difference. The inrush of external atmosphere through the rupture panel fills both the tube and the vacuum drawing on it, and in this way the pressure drop in the tube is quickly limited and reversed. In summary, the results from the 1D model indicate that the 3-D calculations are accurate …
Date: November 6, 2000
Creator: Garcia, M
Object Type: Report
System: The UNT Digital Library
Evaluation of Elevated Tritium Levels in Groundwater Downgradient from the 618-11 Burial Ground Phase I Investigation (open access)

Evaluation of Elevated Tritium Levels in Groundwater Downgradient from the 618-11 Burial Ground Phase I Investigation

This report describes the results of the preliminary investigation of elevated tritium in groundwater discovered near the 618-11 burial ground, located in the eastern part of the Hanford Site.
Date: June 6, 2000
Creator: Dresel, P Evan; Williams, Bruce A.; Evans, John C.; Smith, Ronald M.; Thompson, Christopher J. & Hulstrom, Larry C.
Object Type: Report
System: The UNT Digital Library
Texas Disease Prevention News, Volume 60, Number 23, November 2000 (open access)

Texas Disease Prevention News, Volume 60, Number 23, November 2000

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.
Date: November 6, 2000
Creator: Texas. Department of Health.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Form CJ-7, Parole Data Survey: 2000 (open access)

Form CJ-7, Parole Data Survey: 2000

Blank parole data survey containing a series of questions related to the parole population in a particular location, with instructions for filling out the survey.
Date: November 6, 2000
Creator: United States. Bureau of Justice Statistics.
Object Type: Text
System: The UNT Digital Library
Form CJ-8, Probation Data Survey: 2000 (open access)

Form CJ-8, Probation Data Survey: 2000

Blank probation data survey containing a series of questions related to the probationary population in a particular location, with instructions for filling out the survey.
Date: November 6, 2000
Creator: United States. Bureau of Justice Statistics.
Object Type: Text
System: The UNT Digital Library
POST-REMEDIATION BIOMONITORING OF PESTICIDES AND OTHER CONTAMINANTS IN MARINE WATERS AND SEDIMENT NEAR THE UNITED HECKATHORN SUPERFUND SITE, RICHMOND, CALIFORNIA (open access)

POST-REMEDIATION BIOMONITORING OF PESTICIDES AND OTHER CONTAMINANTS IN MARINE WATERS AND SEDIMENT NEAR THE UNITED HECKATHORN SUPERFUND SITE, RICHMOND, CALIFORNIA

Marine sediment remediation at the United Heckathorn Superfund Site was completed in April 1997. Water and mussel tissues were sampled in February 1999 from four stations near Lauritzen Canal in Richmond, California, for Year 2 of post-remediation monitoring of marine areas near the United Heckathorn Site. Dieldrin and dichlorodiphenyl trichloroethane (DDT) were analyzed in water samples, tissue samples from resident mussels, and tissue samples from transplanted mussels deployed for 4 months. Mussel tissues were also analyzed for polychlorinated biphenyls (PCB), which were detected in sediment samples. Chlorinated pesticide concentrations in water samples were similar to preremediation levels and did not meet remediation goals. Biomonitoring results indicated that the bioavailability of chlorinated pesticides has been reduced from preremediation levels both in the dredged area and throughout Richmond Harbor. Total DDT and dieldrin concentrations in mussel tissues were lower than measured levels from preremediation surveys and also lower than Year 1 levels from post-remediation biomonitoring. Sediment analyses showed the presence of elevated DDT, dieldrin, PCB aroclor 1254, and very high levels of polynuclear aromatic hydrocarbons (PAH) in Lauritzen Channel.
Date: September 6, 2000
Creator: Antrim, Liam D. & Kohn, Nancy P.
Object Type: Report
System: The UNT Digital Library
Anti-B-B Mixing Constrains Topcolor-Assisted Technicolor (open access)

Anti-B-B Mixing Constrains Topcolor-Assisted Technicolor

We argue that extended technicolor augmented with topcolor requires that all mixing between the third and the first two quark generations resides in the mixing matrix of left-handed down quarks. Then, the anti-B_d--B_d mixing that occurs in topcolor models constrains the coloron and Z' boson masses to be greater than about 5 TeV. This implies fine tuning of the topcolor couplings to better than 1percent.
Date: December 6, 2000
Creator: Burdman, Gustavo; Lane, Kenneth & Rador, Tonguc
Object Type: Article
System: The UNT Digital Library
MSW Effects in Vacuum Oscillations (open access)

MSW Effects in Vacuum Oscillations

We point out that for solar neutrino oscillations with the mass-squared difference of Delta m^2 ~;; 10^-10 - 10^-9 eV^2, traditionally known as"vacuum oscillation'' range, the solar matter effects are non-negligible, particularly for the low energy pp neutrinos. One consequence of this is that the values of the mixing angle theta and pi/2-theta are not equivalent, leading to the need to consider the entire physical range of the mixing angle 0<=theta<=pi/2 when determining the allowed values of the neutrino oscillation parameters.
Date: February 6, 2000
Creator: Friedland, Alexander
Object Type: Article
System: The UNT Digital Library