Coarse and Fine Grain Parallelism Performance Exploration in Ares (open access)

Coarse and Fine Grain Parallelism Performance Exploration in Ares

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Date: January 15, 2013
Creator: Collette, M R & Karlin, I
Object Type: Article
System: The UNT Digital Library
Evaluation Of A Turbidity Meter For Use At The Defense Waste Processing Facility (open access)

Evaluation Of A Turbidity Meter For Use At The Defense Waste Processing Facility

Savannah River Remediation's (SRR's) Defense Waste Processing Facility (DWPF) Laboratory currently tests for sludge carry-over into the Recycle Collection Tank (RCT) by evaluating the iron concentration in the Slurry Mix Evaporator Condensate Tank (SMECT) and relating this iron concentration to the amount of sludge solids present. A new method was proposed for detecting the amount of sludge in the SMECT that involves the use of an Optek turbidity sensor. Waste Services Laboratory (WSL) personnel conducted testing on two of these units following a test plan developed by Waste Solidification Engineering (WSE). Both Optek units (SN64217 and SN65164) use sensor model AF16-N and signal converter model series C4000. The sensor body of each unit was modified to hold a standard DWPF 12 cc sample vial, also known as a ''peanut'' vial. The purpose of this testing was to evaluate the use of this model of turbidity sensor, or meter, to provide a measurement of the sludge solids present in the SMECT based upon samples from that tank. During discussions of the results from this study by WSE, WSL, and Savannah River National Laboratory (SRNL) personnel, an upper limit on the acceptable level of solids in SMECT samples was set at 0.14 …
Date: January 15, 2013
Creator: Mahannah, R. N. & Edwards, T. B.
Object Type: Report
System: The UNT Digital Library
Final Report for the San Jose State University Effort for Lawrence Livermore National Laboratory (open access)

Final Report for the San Jose State University Effort for Lawrence Livermore National Laboratory

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Date: January 15, 2013
Creator: Johnson, M. S. & Parvin, K.
Object Type: Report
System: The UNT Digital Library
First demonstration of a sub-keV electron recoil energy threshold in a liquid argon ionization chamber (open access)

First demonstration of a sub-keV electron recoil energy threshold in a liquid argon ionization chamber

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Date: January 15, 2013
Creator: Sangiorgio, S; Bernstein, A; Colomean, J; Foxe, M; Hagmann, C; Joshi, T et al.
Object Type: Report
System: The UNT Digital Library
LLNL Site Update for ESnet Site Coordinators Meeting Winter 2013 (open access)

LLNL Site Update for ESnet Site Coordinators Meeting Winter 2013

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Date: January 15, 2013
Creator: Panaga, M L
Object Type: Report
System: The UNT Digital Library
Massively Parallel Loading (open access)

Massively Parallel Loading

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Date: January 15, 2013
Creator: Frings, W.; Ahn, D. H.; LeGendre, M.; Gamblin, T.; de Supinski, B. R. & Wolf, F.
Object Type: Article
System: The UNT Digital Library
Pore-Water Extraction Scale-Up Study for the SX Tank Farm (open access)

Pore-Water Extraction Scale-Up Study for the SX Tank Farm

The phenomena related to pore-water extraction from unsaturated sediments have been previously examined with limited laboratory experiments and numerical modeling. However, key scale-up issues have not yet been addressed. Laboratory experiments and numerical modeling were conducted to specifically examine pore-water extraction for sediment conditions relevant to the vadose zone beneath the SX Tank Farm at Hanford Site in southeastern Washington State. Available SX Tank Farm data were evaluated to generate a conceptual model of the subsurface for a targeted pore-water extraction application in areas with elevated moisture and Tc-99 concentration. The hydraulic properties of the types of porous media representative of the SX Tank Farm target application were determined using sediment mixtures prepared in the laboratory based on available borehole sediment particle size data. Numerical modeling was used as an evaluation tool for scale-up of pore-water extraction for targeted field applications.
Date: January 15, 2013
Creator: Truex, Michael J.; Oostrom, Martinus; Wietsma, Thomas W.; Last, George V. & Lanigan, David C.
Object Type: Report
System: The UNT Digital Library
Real-Time Vehicle-Mounted Multistatic Ground Penetrating Radar Imaging System for Buried Object Detection (open access)

Real-Time Vehicle-Mounted Multistatic Ground Penetrating Radar Imaging System for Buried Object Detection

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Date: January 15, 2013
Creator: Chambers, D H; Paglieroni, D W; Mast, J E & Beer, N R
Object Type: Report
System: The UNT Digital Library
Representation of Ideal Magnetohydrodynamic Modes (open access)

Representation of Ideal Magnetohydrodynamic Modes

One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through δ Β = ∇ X (xi X B) ensures that δ B • ∇ ψ = 0 at a resonance, with ψ labelling an equilibrium flux surface. Also useful for the analysis of guiding center orbits in a perturbed field is the representation δ Β = ∇ X αB. These two representations are equivalent, but the vanishing of δ B • ∇ψ at a resonance is necessary but not sufficient for the preservation of field line topology, and a indiscriminate use of either perturbation in fact destroys the original equilibrium flux topology. It is necessary to find the perturbed field to all orders in xi to conserve the original topology. The effect of using linearized perturbations on stability and growth rate calculations is discussed
Date: January 15, 2013
Creator: White, Roscoe B.
Object Type: Report
System: The UNT Digital Library
Review of the Oak Ridge National Laboratory (ORNL) neutronic calculations regarding the conversion of the high flux isotope reactor (HFIR) to the use of low enriched uranium (LEU) fuel (open access)

Review of the Oak Ridge National Laboratory (ORNL) neutronic calculations regarding the conversion of the high flux isotope reactor (HFIR) to the use of low enriched uranium (LEU) fuel

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Date: January 15, 2013
Creator: Bergeron, A. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Scalable Mesh Management for Patch-based AMR (open access)

Scalable Mesh Management for Patch-based AMR

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Date: January 15, 2013
Creator: Gunney, B. N.
Object Type: Article
System: The UNT Digital Library
Scientific Data Management Center for Enabling Technologies (open access)

Scientific Data Management Center for Enabling Technologies

Managing scientific data has been identified by the scientific community as one of the most important emerging needs because of the sheer volume and increasing complexity of data being collected. Effectively generating, managing, and analyzing this information requires a comprehensive, end-to-end approach to data management that encompasses all of the stages from the initial data acquisition to the final analysis of the data. Fortunately, the data management problems encountered by most scientific domains are common enough to be addressed through shared technology solutions. Based on community input, we have identified three significant requirements. First, more efficient access to storage systems is needed. In particular, parallel file system and I/O system improvements are needed to write and read large volumes of data without slowing a simulation, analysis, or visualization engine. These processes are complicated by the fact that scientific data are structured differently for specific application domains, and are stored in specialized file formats. Second, scientists require technologies to facilitate better understanding of their data, in particular the ability to effectively perform complex data analysis and searches over extremely large data sets. Specialized feature discovery and statistical analysis techniques are needed before the data can be understood or visualized. Furthermore, interactive …
Date: January 15, 2013
Creator: Vouk, Mladen A.
Object Type: Report
System: The UNT Digital Library
Toward a Predictive First-Principles Description of Solid Molecular Hydrogen with Density-Functional Theory (open access)

Toward a Predictive First-Principles Description of Solid Molecular Hydrogen with Density-Functional Theory

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Date: January 15, 2013
Creator: Morales, M A; McMahon, J M; Pierleoni, C & Ceperley, D M
Object Type: Article
System: The UNT Digital Library
Geant4 Applications for Modeling Molecular Transport in Complex Vacuum Geometries (open access)

Geant4 Applications for Modeling Molecular Transport in Complex Vacuum Geometries

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Date: February 15, 2013
Creator: Singal, J.; Langton, J. & Schindler, R.
Object Type: Article
System: The UNT Digital Library
Recovery Act: Low-Cost, Highly Lambertian Reflector Composite For Improved LED Fixture Efficiency and Lifetime (open access)

Recovery Act: Low-Cost, Highly Lambertian Reflector Composite For Improved LED Fixture Efficiency and Lifetime

The overall objective of the program was to demonstrate a 98% or greater reflective, highly diffuse, low-cost composite material that significantly improves luminaire efficiency, is able to withstand 50,000 hours or greater luminaire operation under expected LED system thermal and environmental operating extremes and meets the cost targets required to be an effective commercial solution for the Solid State Lighting industry. This project met most of the goals defined and contributed to the understanding of high reflectance, white coatings. Research under this program increased the understanding of coatings development using particle size reduction techniques and preparation of coating solutions with a broad range of particle types. The research explored scale-up of coating systems and generated understanding of processing required for high volume manufacturing applications. The work demonstrated how coating formulation and application technique can translate to material durability and LED system lifetime. The research also demonstrated improvements in lighting efficiency to be gained using high reflectance white coatings.
Date: February 15, 2013
Creator: Teather, Eric
Object Type: Report
System: The UNT Digital Library
Some Sample Calculations for the Far Field Harmonic Power and Angular Pattern in LCLS-1 and LCLS-2 (open access)

Some Sample Calculations for the Far Field Harmonic Power and Angular Pattern in LCLS-1 and LCLS-2

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Date: February 15, 2013
Creator: Fawley, W. M.
Object Type: Report
System: The UNT Digital Library
UNDERSTANDING THE LOCAL ATOMIC LEVEL EFFECTS OF DOPANTS IN COMPLEX METAL HYDRIDES USING SYNCHROTRON XRAY ABSORPTION SPECTROSCOPY AND DENSITY FUNCTIONAL THEORY (open access)

UNDERSTANDING THE LOCAL ATOMIC LEVEL EFFECTS OF DOPANTS IN COMPLEX METAL HYDRIDES USING SYNCHROTRON XRAY ABSORPTION SPECTROSCOPY AND DENSITY FUNCTIONAL THEORY

This work resulted in five peer-reviewed journal publications (appended), as well as one doctoral dissertation and two masters theses.
Date: February 15, 2013
Creator: Dobbins, Tabbetha
Object Type: Report
System: The UNT Digital Library
XML Network Description Language (XNDL) for ns-3 (open access)

XML Network Description Language (XNDL) for ns-3

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Date: February 15, 2013
Creator: Banks, L. E.; Barnes, P. D.; Jefferson, D. R. & Nikolaev, S.
Object Type: Report
System: The UNT Digital Library
Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface Radar and Satellite Data in Support of ARM SCM Activities (open access)

Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface Radar and Satellite Data in Support of ARM SCM Activities

Single-column modeling (SCM) is one of the key elements of Atmospheric Radiation Measurement (ARM) research initiatives for the development and testing of various physical parameterizations to be used in general circulation models (GCMs). The data required for use with an SCM include observed vertical profiles of temperature, water vapor, and condensed water, as well as the large-scale vertical motion and tendencies of temperature, water vapor, and condensed water due to horizontal advection. Surface-based measurements operated at ARM sites and upper-air sounding networks supply most of the required variables for model inputs, but do not provide the horizontal advection term of condensed water. Since surface cloud radar and microwave radiometer observations at ARM sites are single-point measurements, they can provide the amount of condensed water at the location of observation sites, but not a horizontal distribution of condensed water contents. Consequently, observational data for the large-scale advection tendencies of condensed water have not been available to the ARM cloud modeling community based on surface observations alone. This lack of advection data of water condensate could cause large uncertainties in SCM simulations. Additionally, to evaluate GCMs’ cloud physical parameterization, we need to compare GCM results with observed cloud water amounts over a …
Date: March 15, 2013
Creator: Liu, Guosheng
Object Type: Report
System: The UNT Digital Library
Disposal Systems Evaluation Framework DSEF Version 2.1 User's Manual (open access)

Disposal Systems Evaluation Framework DSEF Version 2.1 User's Manual

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Date: March 15, 2013
Creator: Greenberg, H. R.; Blink, J. A.; Sutton, M. & Wolery, T. J.
Object Type: Report
System: The UNT Digital Library
Evaluating greenhouse gas emissions from hydropower complexes on large rivers in Eastern Washington (open access)

Evaluating greenhouse gas emissions from hydropower complexes on large rivers in Eastern Washington

Water bodies, such as freshwater lakes, are known to be net emitters of carbon dioxide (CO2), and methane (CH4). In recent years, significant greenhouse gas (GHG) emissions from tropical, boreal, and mid-latitude reservoirs have been reported. At a time when hydropower is increasing worldwide, better understanding of seasonal and regional variation in GHG emissions is needed in order to develop a predictive understanding of such fluxes within man-made impoundments. We examined power-producing dam complexes within xeric temperate locations in the northwestern United States. Sampling environments on the Snake (Lower Monumental Dam Complex) and Columbia Rivers (Priest Rapids Dam Complex) included tributary, mainstem, embayment, forebay, and tailrace areas during winter and summer 2012. At each sampling location, GHG measurement pathways included surface gas flux, degassing as water passed through dams during power generation, ebullition within littoral embayments, and direct sampling of hyporheic pore-water. Measurements were also carried out in a free-flowing reach of the Columbia River to estimate unaltered conditions. Surface flux resulted in very low emissions, with reservoirs acting as a sink for CO2 (up to –262 mg m-2 d-1, which is within the range previously reported for similarly located reservoirs). Surface flux of methane remained below 1 mg CH4 …
Date: March 15, 2013
Creator: Arntzen, Evan V.; Miller, Benjamin L.; O'Toole, Amanda C.; Niehus, Sara E. & Richmond, Marshall C.
Object Type: Report
System: The UNT Digital Library
Final Technical Report on Radioxenon Event Analysis (open access)

Final Technical Report on Radioxenon Event Analysis

This is a final deliverable report for the Advanced Spectral Analysis for Radioxenon project with a focus on radioxenon event categorization.
Date: March 15, 2013
Creator: Ely, James H.; Cooper, Matthew W.; Hayes, James C.; Heimbigner, Tom R.; McIntyre, Justin I. & Schrom, Brian T.
Object Type: Report
System: The UNT Digital Library
Real-time manifestation of strongly coupled spin and charge order parameters in stripe-ordered nickelates via time-resolved resonant x-ray diffraction (open access)

Real-time manifestation of strongly coupled spin and charge order parameters in stripe-ordered nickelates via time-resolved resonant x-ray diffraction

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Date: March 15, 2013
Creator: Chuang, Y. D.; Lee, W. S.; Kung, Y. F.; Sorini, A. P.; Moritz, B.; Moore, R. G. et al.
Object Type: Article
System: The UNT Digital Library
A reduced graphene oxide/Co{sub 3}O{sub 4} composite for supercapacitor electrode (open access)

A reduced graphene oxide/Co{sub 3}O{sub 4} composite for supercapacitor electrode

20 nm sized Co{sub 3}O{sub 4} nanoparticles are in-situ grown on the chemically reduced graphene oxide (rGO) sheets to form a rGO-Co{sub 3}O{sub 4} composite during hydrothermal processing. The rGO-Co{sub 3}O{sub 4} composite is employed as the pseudocapacitor electrode in the 2 M KOH aqueous electrolyte solution. The rGOCo{sub 3}O{sub 4} composite electrode exhibits a specific capacitance of 472 F/g at a scan rate of 2 mV/s in a two-electrode cell. 82.6% of capacitance is retained when the scan rate increases to 100 mV/s. The rGOCo{sub 3}O{sub 4} composite electrode shows high rate capability and excellent long-term stability. It also exhibits high energy density at relatively high power density. The energy density reaches 39.0 Wh/kg at a power density of 8.3 kW/kg. The super performance of the composite electrode is attributed to the synergistic effects of small size and good redox activity of the Co{sub 3}O{sub 4} particles combined with high electronic conductivity of the rGO sheets.
Date: March 15, 2013
Creator: Xiang, Chengcheng; Li, Ming; Zhi, Mingjia; Manivannan, Ayyakkannu & Wu, Nianqiang
Object Type: Article
System: The UNT Digital Library