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A texture-based framework for improving CFD data visualization in a virtual environment

Description: In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated hut require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx}10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions hut limiting interaction for investigating the field.
Date: May 5, 2005
Creator: Bivins, Gerrick O'Ron
Partner: UNT Libraries Government Documents Department
open access

A texture-based frameowrk for improving CFD data visualization in a virtual environment

Description: In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated but require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx} 10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions but limiting interaction for investigating the field.
Date: May 1, 2005
Creator: Biveins, Gerrick O'Ron
Partner: UNT Libraries Government Documents Department
open access

Elastic Wave Radiation from a Line Source of Finite Length

Description: Straightforward algebraic expressions describing the elastic wavefield produced by a line source of finite length are derived in circular cylindrical coordinates. The surrounding elastic medium is assumed to be both homogeneous and isotropic, anc[ the source stress distribution is considered axisymmetic. The time- and space-domain formulae are accurate at all distances and directions from the source; no fa-field or long-wavelength assumptions are adopted for the derivation. The mathematics yield a unified treatment of three different types of sources: an axial torque, an axial force, and a radial pressure. The torque source radiates only azirnuthally polarized shear waves, whereas force and pressure sources generate simultaneous compressional and shear radiation polarized in planes containing the line source. The formulae reduce to more familiar expressions in the two limiting cases where the length of the line source approaches zero and infinity. Far-field approximations to the exact equations indicate that waves radiated parallel to the line source axI.s are attenuated relative to those radiated normal to the axis. The attenuation is more severe for higher I?equencies and for lower wavespeeds. Hence, shear waves are affected more than compressional waves. This fi-equency- and directiondependent attenuation is characterized by an extremely simple mathematical formula, and is readily apparent in example synthetic seismograms.
Date: November 4, 1998
Creator: Aldridge, D.F.
Partner: UNT Libraries Government Documents Department
open access

Evaluated Decay Data for {Sup 246}CM.

Description: The Nuclear Data and Measurement Series document results of studies in the field of microscopic nuclear data. The primary objective is the dissemination of information in the comprehensive form required for nuclear technology applications. This Series is devoted to: (a) measured microscopic nuclear parameters, (b) experimental techniques and facilities employed in measurements, (c) the analysis, correlation and interpretation of nuclear data, and (d) the compilation and evaluation of nuclear data. Contributions to this Series are reviewed to assure technical competence and, unless otherwise stated, the contents can be formally referenced. This Series does not supplant formal journal publication, but it does provide the more extensive information required for technological applications (e.g., tabulated numerical data) in a timely manner.
Date: February 26, 2007
Creator: Kondev, F. G.
Partner: UNT Libraries Government Documents Department
open access

Standard Atomic Weights Tables 2007 Abridged to Four and Five Significant Figures

Description: In response to a recommendation to the Commission on Isotopic Abundances and Atomic Weights (CIAAW) that abridged versions of the Table on Standard Atomic Weights be prepared and published, this report has been prepared. A brief history is presented of such Atomic Weight tables that have been abridged to four significant figures and to five significant figures are noted. Tables of Standard Atomic Weight values abridged to four places and five places from the official 2007 Table of Atomic Weights approved by CIAAW are included.
Date: August 1, 2007
Creator: Holden, N. E.
Partner: UNT Libraries Government Documents Department
open access

Fast-neutrons incident on gadolinium.

Description: Reports in the Argonne National Laboratory Nuclear Data and Measurement Series present results of studies in the field of microscopic nuclear data. The primary objective of the series is the dissemination of information in the comprehensive form required for nuclear technology applications. This Series is devoted to: (a) measured microscopic nuclear parameters, (b) experimental techniques and facilities employed in measurements, (c) the analysis, correlation and interpretation of nuclear data, and (d) the compilation and evaluation of nuclear data. Contributions to this Series are reviewed to assure technical competence and, unless otherwise stated, the contents can be formally referenced. This Series does not supplant formal journal publication, but it does provide the more extensive information required for technological applications (e.g., tabulated numerical data) in a timely manner.
Date: May 24, 2004
Creator: Smith, A. B.
Partner: UNT Libraries Government Documents Department
open access

Hanford Site Environmental Surveillance Data Report for Calendar Year 2001

Description: This document contains the tables of data on which PNNL's environmental surveillance summary information is based. This data report contains the actual raw data used to create the tables and summaries in the Hanford Site Environmental Report for Calendar Year 2001.
Date: September 2, 2002
Creator: Bisping, Lynn E.
Partner: UNT Libraries Government Documents Department
open access

Characteristics of seismic waves from Soviet peaceful nuclear explosions in salt

Description: The report is carried out by the Institute for Dynamics of the Geospheres, Russian Academy of Sciences under contract NB280344 with Lawrence Livermore National Laboratory, University of California. The work includes investigation of seismic waves generation and propagation from Soviet peaceful underground nuclear explosions in salt based on the data from temporary and permanent seismic stations. The explosions were conducted at the sites Azgir and Vega within the territory of the Caspian depression of the Russian platform. The data used were obtained in the following conditions of conduction: epicentral distance range from 0 to 60 degrees, yields from 1 to 65 kt and depths of burial from 160 to 1500 m.
Date: April 1, 1995
Creator: Adushkin, V. V.; Kaazik, P. B.; Kostyuchenko, V. N.; Kuznetsov, O. P.; Nedoshivin, N. I.; Rubinshtein, K. D. et al.
Partner: UNT Libraries Government Documents Department
open access

The size of a polymer of string-bits: a numerical investigation

Description: In string bit models, string is described as a polymer of point-like constituents. We attempt to use string-bit ideas to investigate how the size of string is affected by string interactions in a non-perturbative context. Lacking adequate methods to deal with the full complications of bit rearrangement interactions, we study instead a simplified analog model with only ``direct`` potential interactions among the bits. We use the variational principle in an approximate calculation of the mean-square size of a polymer as a function of the number of constituents/bits for various interaction strengths {ital g} in three specific models. 14 refs., 2 figs.
Date: April 1, 1997
Creator: Bergman, Oren & Thorn, Charles B.
Partner: UNT Libraries Government Documents Department
open access

Proper motion with HST: Searching for high-velocity stars in the core of the globular cluster 47 Tucanae

Description: Binary stars play an essential role during the late phases of the dynamical evolution of a globular cluster. They transfer energy to passing stars and so can strongly influence the cluster evolution, enough to delay, halt, and even reverse core collapse. Hard binaries are known to exist in cluster cores, e.g., in the form of millisecond pulsars (about half of the millisecond pulsars observed in 47 Tucanae are such hard binaries). The presence of hard binaries may also be revealed by searching for the by-products of close encounters: high- velocity stars, such as those discovered in the core of 47 Tuc by Meylan et al. (1991) and Gebhardt et al. (1995). These studies represent the limit of the radial velocity data which can be obtained from the ground. If more progress is to be made, it must come through obtaining proper motions--a task for which {ital only} the Hubble Space Telescope (HST) is suitable. We are using WFPC2 to obtain deep U (F300W) images of the core of 47 Tuc at three different epochs over two years, with which we will measure differential proper motions to a 1-{sigma} limit of 0.23 mas/yr. This--rather conservative--estimate corresponds to a 5-{sigma} detection of all stars with tangential velocities greater than 22 km s{sup -1}. By using the F300W filter we can measure stars over the whole color-magnitude diagram, from the red-giant branch to well down the main sequence. Such a complete census will provide unique constraints as a function of the stellar mass on relaxation processes, collision and ejection rates, and the velocity distribution. Here we report on the first-epoch (Cycle 5) observations of this project. Although no proper motions are available yet, some preliminary by-product results are presented. These include luminosity functions and color-magnitude diagrams for the core of 47 Tuc and …
Date: February 13, 1996
Creator: Meylan, G.; Minniti, D.; Pryor, C.; Tinney, C.G.; Phinney, E.S. & Sams, B.
Partner: UNT Libraries Government Documents Department
open access

Random polycrystals of grains containing cracks: Model ofquasistatic elastic behavior for fractured systems

Description: A model study on fractured systems was performed using aconcept that treats isotropic cracked systems as ensembles of crackedgrains by analogy to isotropic polycrystalline elastic media. Theapproach has two advantages: (a) Averaging performed is ensembleaveraging, thus avoiding the criticism legitimately leveled at mosteffective medium theories of quasistatic elastic behavior for crackedmedia based on volume concentrations of inclusions. Since crack effectsare largely independent of the volume they occupy in the composite, sucha non-volume-based method offers an appealingly simple modelingalternative. (b) The second advantage is that both polycrystals andfractured media are stiffer than might otherwise be expected, due tonatural bridging effects of the strong components. These same effectshave also often been interpreted as crack-crack screening inhigh-crack-density fractured media, but there is no inherent conflictbetween these two interpretations of this phenomenon. Results of thestudy are somewhat mixed. The spread in elastic constants observed in aset of numerical experiments is found to be very comparable to the spreadin values contained between the Reuss and Voigt bounds for thepolycrystal model. However, computed Hashin-Shtrikman bounds are much tootight to be in agreement with the numerical data, showing thatpolycrystals of cracked grains tend to violate some implicit assumptionsof the Hashin-Shtrikman bounding approach. However, the self-consistentestimates obtained for the random polycrystal model are nevertheless verygood estimators of the observed average behavior.
Date: July 8, 2006
Creator: Berryman, James G. & Grechka, Vladimir
Partner: UNT Libraries Government Documents Department
open access

Quantifying Flaw Characteristics from IR NDE Data

Description: Work is presented which allows flaw characteristics to be quantified from the transient IR NDE signature. The goal of this effort was to accurately determine the type, size and depth of flaws revealed with IR NDE, using sonic IR as the example IR NDE technique. Typically an IR NDE experiment will result in a positive qualitative indication of a flaw such as a cold or hot spot in the image, but will not provide quantitative data thereby leaving the practitioner to make educated guesses as to the source of the signal. The technique presented here relies on comparing the transient IR signature to exact heat transfer analytical results for prototypical flaws, using the flaw characteristics as unknown fitting parameters. A nonlinear least squares algorithm is used to evaluate the fitting parameters, which then provide a direct measure of the flaw characteristics that can be mapped to the imaged surface for visual reference. The method uses temperature data for the heat transfer analysis, so radiometric calibration of the IR signal is required. The method provides quantitative data with a single thermal event (e.g. acoustic pulse or flash), as compared to phase-lock techniques that require many events. The work has been tested with numerical data but remains to be validated by experimental data, and that effort is underway.
Date: February 14, 2003
Creator: Miller, W; Philips, N R; Burke, M W & Robbins, C L
Partner: UNT Libraries Government Documents Department
open access

Semi-annual report of the Department of Energy, Office of Environmental Management, Quality Assessment Program

Description: This Quality Assessment Program (QAP) is designed to test the quality of the environmental measurements being reported to the Department of Energy by its contractors. Since 1976, real or synthetic environmental samples that have been prepared and thoroughly analyzed at the Environmental Measurements Laboratory (EML) have been distributed at first quarterly and then semi-annually to these contractors. Their results, which are returned to EML within 90 days, are compiled with EML`s results and are reported back to the participating contractors 30 days later. This report presents the results from the analysis of the 48th set of environmental quality assessment samples (QAP XLVIII) that were received on or before June 1, 1998.
Date: July 1, 1998
Creator: Greenlaw, P. D. & Minick, S. K.
Partner: UNT Libraries Government Documents Department
open access

Managing Senegalese water resources: Definition and relative importance of information needs

Description: This report provides an overview of the results of the Vital Issues process as implemented for the Senegal Water Resources Management Initiative, a collaborative effort between the Senegalese Ministry of Water Resources and Sandia National Laboratories. This Initiative is being developed to assist in the development of an efficient and sustainable water resources management system for Senegal. The Vital Issues process was used to provide information for the development of a proposal that will recommend actions to address the key management issues and establish a state-of-the-art decision support system (DSS) for managing Senegal`s water resources. Three Vital Issues panel meetings were convened to (1) develop a goal statement and criteria for identifying and ranking the issues vital to water resources management in Senegal; (2) define and rank the issues, and (3) identify and prioritize a preliminary list of information needed to address the vital issues. The selection of panelists from the four basic institutional perspectives (government, industry, academe, and citizens` interest groups) ensured a high level of stakeholder representation on the panels.
Date: September 1998
Creator: Engi, D.
Partner: UNT Libraries Government Documents Department
open access

Annual Hanford seismic report -- fiscal year 1996

Description: Seismic monitoring (SM) at the Hanford Site was established in 1969 by the US Geological Survey (USGS) under a contract with the US Atomic Energy Commission. Since 1980, the program has been managed by several contractors under the US Department of Energy (USDOE). Effective October 1, 1996, the Seismic Monitoring workscope, personnel, and associated contracts were transferred to the USDOE Pacific Northwest National Laboratory (PNNL). SM is tasked to provide an uninterrupted collection and archives of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) located on and encircling the Hanford Site. SM is also tasked to locate and identify sources of seismic activity and monitor changes in the historical pattern of seismic activity at the Hanford Site. The data compiled are used by SM, Waste Management, and engineering activities at the Hanford Site to evaluate seismic hazards and seismic design for the Site.
Date: December 1, 1996
Creator: Hartshorn, D. C. & Reidel, S. P.
Partner: UNT Libraries Government Documents Department
open access

Evaluation of options for reclamation of the Salton Sea

Description: Los Alamos National Laboratory, which is operated by the University of California for the Department of Energy, was asked last May by the Congressional Salton Sea Task Force to provide technical support for the remediation of the ecological problems in the Salton Sea. The results of their work in evaluating various concepts for addressing high salinity and variable water levels of the Sea relate to H.R. 3267 is presented. The results are preliminary and in some cases qualitative, but they can be used to help guide decision-makers in their deliberations. Ultimately, selecting the best solution for reclaiming the Salton Sea will have to integrate performance, economic, ecological, and institutional factors into the decision.
Date: November 1998
Creator: Hardie, R. W.
Partner: UNT Libraries Government Documents Department
open access

Semi-annual report of the Department of Energy, Office of Environmental Management, Quality Assessment Program

Description: This report presents the results from the analysis of the 44th set of environmental quality assessment samples (QAP XLIV) that were received on or before June 3, 1996. The QAP is designed to test the quality of environmental measurements being reported to the Department of Energy by it`s contractors. Since 1976, samples have been prepared and analyzed by the Environmental measurements Laboratory.
Date: July 1, 1996
Creator: Sanderson, C.G. & Greenlaw, P.
Partner: UNT Libraries Government Documents Department
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