States

Award Nomination Information for Lawrence Livermore National LaboratorySkillSoft Perspectives Conference 2013 (open access)

Award Nomination Information for Lawrence Livermore National LaboratorySkillSoft Perspectives Conference 2013

None
Date: February 25, 2013
Creator: Positeri, L A & Molyneaux, B R
Object Type: Article
System: The UNT Digital Library
Interim salt disposition program macrobatch 6 tank 21H qualification monosodium titanate and cesium mass transfer tests (open access)

Interim salt disposition program macrobatch 6 tank 21H qualification monosodium titanate and cesium mass transfer tests

Savannah River National Laboratory (SRNL) performed experiments on qualification material for use in the Interim Salt Disposition Program (ISDP) Batch 6 processing. This qualification material was a set of six samples from Tank 21H in October 2012. This sample was used as a real waste demonstration of the Actinide Removal Process (ARP) and the Extraction-Scrub-Strip (ESS) tests process. The Tank 21H sample was contacted with a reduced amount (0.2 g/L) of MST and characterized for strontium and actinide removal at 0 and 8 hour time intervals in this salt batch. {sup 237}Np and {sup 243}Am were both observed to be below detection limits in the source material, and so these results are not reported in this report. The plutonium and uranium samples had decontamination factor (DF) values that were on par or slightly better than we expected from Batch 5. The strontium DF values are slightly lower than expected but still in an acceptable range. The Extraction, Scrub, and Strip (ESS) testing demonstrated cesium removal, stripping and scrubbing within the acceptable range. Overall, the testing indicated that cesium removal is comparable to prior batches at MCU.
Date: February 25, 2013
Creator: Washington, A. L. II; Peters, T. B. & Fink, S. D.
Object Type: Report
System: The UNT Digital Library
Fox Ridge Energy and Education Institute Project Development Final Report (open access)

Fox Ridge Energy and Education Institute Project Development Final Report

Project final report and summary.
Date: February 25, 2012
Creator: Osborn, Dale
Object Type: Report
System: The UNT Digital Library
Cognitive Foundations for Visual Analytics (open access)

Cognitive Foundations for Visual Analytics

In this report, we provide an overview of scientific/technical literature on information visualization and VA. Topics discussed include an update and overview of the extensive literature search conducted for this study, the nature and purpose of the field, major research thrusts, and scientific foundations. We review methodologies for evaluating and measuring the impact of VA technologies as well as taxonomies that have been proposed for various purposes to support the VA community. A cognitive science perspective underlies each of these discussions.
Date: February 25, 2011
Creator: Greitzer, Frank L.; Noonan, Christine F. & Franklin, Lyndsey
Object Type: Report
System: The UNT Digital Library
Edge Simulation Laboratory Project Report (open access)

Edge Simulation Laboratory Project Report

None
Date: February 25, 2011
Creator: Cohen, R H; Dorf, M; Dorr, M & Rognlien, T D
Object Type: Report
System: The UNT Digital Library
Evaluation of Simple Causal Message Logging for Large-Scale Fault Tolerant HPC Systems (open access)

Evaluation of Simple Causal Message Logging for Large-Scale Fault Tolerant HPC Systems

The era of petascale computing brought machines with hundreds of thousands of processors. The next generation of exascale supercomputers will make available clusters with millions of processors. In those machines, mean time between failures will range from a few minutes to few tens of minutes, making the crash of a processor the common case, instead of a rarity. Parallel applications running on those large machines will need to simultaneously survive crashes and maintain high productivity. To achieve that, fault tolerance techniques will have to go beyond checkpoint/restart, which requires all processors to roll back in case of a failure. Incorporating some form of message logging will provide a framework where only a subset of processors are rolled back after a crash. In this paper, we discuss why a simple causal message logging protocol seems a promising alternative to provide fault tolerance in large supercomputers. As opposed to pessimistic message logging, it has low latency overhead, especially in collective communication operations. Besides, it saves messages when more than one thread is running per processor. Finally, we demonstrate that a simple causal message logging protocol has a faster recovery and a low performance penalty when compared to checkpoint/restart. Running NAS Parallel Benchmarks …
Date: February 25, 2011
Creator: Bronevetsky, G.; Meneses, E. & Kale, L. V.
Object Type: Article
System: The UNT Digital Library
Interactions between Energy Efficiency Programs funded under the Recovery Act and Utility Customer-Funded Energy Efficiency Programs (open access)

Interactions between Energy Efficiency Programs funded under the Recovery Act and Utility Customer-Funded Energy Efficiency Programs

Since the spring of 2009, billions of federal dollars have been allocated to state and local governments as grants for energy efficiency and renewable energy projects and programs. The scale of this American Reinvestment and Recovery Act (ARRA) funding, focused on 'shovel-ready' projects to create and retain jobs, is unprecedented. Thousands of newly funded players - cities, counties, states, and tribes - and thousands of programs and projects are entering the existing landscape of energy efficiency programs for the first time or expanding their reach. The nation's experience base with energy efficiency is growing enormously, fed by federal dollars and driven by broader objectives than saving energy alone. State and local officials made countless choices in developing portfolios of ARRA-funded energy efficiency programs and deciding how their programs would relate to existing efficiency programs funded by utility customers. Those choices are worth examining as bellwethers of a future world where there may be multiple program administrators and funding sources in many states. What are the opportunities and challenges of this new environment? What short- and long-term impacts will this large, infusion of funds have on utility customer-funded programs; for example, on infrastructure for delivering energy efficiency services or on customer …
Date: February 25, 2011
Creator: Goldman, Charles A.; Stuart, Elizabeth; Hoffman, Ian; Fuller, Merrian C. & Billingsley, Megan A.
Object Type: Report
System: The UNT Digital Library
INVESTIGATION OF CRUSTAL MOTION IN THE TIEN SHAN USING INSAR (open access)

INVESTIGATION OF CRUSTAL MOTION IN THE TIEN SHAN USING INSAR

The northern Tien Shan of Central Asia is an area of active mid-continent deformation. Although far from a plate boundary, this region has experienced 5 earthquakes larger than magnitude 7 in the past century and includes one event that may as be as large as Mw 8.0. Previous studies based on GPS measurements indicate on the order of 23 mm/yr of shortening across the entire Tien Shan and up to 15 mm/year in the northern Tien Shan (Figure 1). The seismic moment release rate appears comparable with the geodetic measured slip, at least to first order, suggesting that geodetic rates can be considered a proxy for accumulation rates of stress for seismic hazard estimation. Interferometric synthetic aperture radar may provide a means to make detailed spatial measurements and hence in identifying block boundaries and assisting in seismic hazard. Therefore, we hoped to define block boundaries by direct measurement and by identifying and resolving earthquake slip. Due to political instability in Kyrgzystan, the existing seismic network has not performed as well as required to precisely determine earthquake hypocenters in remote areas and hence InSAR is highly useful. In this paper we present the result of three earthquake studies and show that …
Date: February 25, 2011
Creator: Mellors, R J
Object Type: Report
System: The UNT Digital Library
LiverTox: Advanced QSAR and Toxicogeomic Software for Hepatotoxicity Prediction (open access)

LiverTox: Advanced QSAR and Toxicogeomic Software for Hepatotoxicity Prediction

YAHSGS LLC and Oak Ridge National Laboratory (ORNL) established a CRADA in an attempt to develop a predictive system using a pre-existing ORNL computational neural network and wavelets format. This was in the interest of addressing national needs for toxicity prediction system to help overcome the significant drain of resources (money and time) being directed toward developing chemical agents for commerce. The research project has been supported through an STTR mechanism and funded by the National Institute of Environmental Health Sciences beginning Phase I in 2004 (CRADA No. ORNL-04-0688) and extending Phase II through 2007 (ORNL NFE-06-00020). To attempt the research objectives and aims outlined under this CRADA, state-of-the-art computational neural network and wavelet methods were used in an effort to design a predictive toxicity system that used two independent areas on which to base the system’s predictions. These two areas were quantitative structure-activity relationships and gene-expression data obtained from microarrays. A third area, using the new Massively Parallel Signature Sequencing (MPSS) technology to assess gene expression, also was attempted but had to be dropped because the company holding the rights to this promising MPSS technology went out of business. A research-scale predictive toxicity database system called Multi-Intelligent System for …
Date: February 25, 2011
Creator: Lu, Po-Yun & Yuracko, Katherine
Object Type: Report
System: The UNT Digital Library
NNSA ASC Exascale Environment Planning, Applications Working Group, Report February 2011 (open access)

NNSA ASC Exascale Environment Planning, Applications Working Group, Report February 2011

The scope of the Apps WG covers three areas of interest: Physics and Engineering Models (PEM), multi-physics Integrated Codes (IC), and Verification and Validation (V&V). Each places different demands on the exascale environment. The exascale challenge will be to provide environments that optimize all three. PEM serve as a test bed for both model development and 'best practices' for IC code development, as well as their use as standalone codes to improve scientific understanding. Rapidly achieving reasonable performance for a small team is the key to maintaining PEM innovation. Thus, the environment must provide the ability to develop portable code at a higher level of abstraction, which can then be tuned, as needed. PEM concentrate their computational footprint in one or a few kernels that must perform efficiently. Their comparative simplicity permits extreme optimization, so the environment must provide the ability to exercise significant control over the lower software and hardware levels. IC serve as the underlying software tools employed for most ASC problems of interest. Often coupling dozens of physics models into very large, very complex applications, ICs are usually the product of hundreds of staff-years of development, with lifetimes measured in decades. Thus, emphasis is placed on portability, …
Date: February 25, 2011
Creator: Still, C. H.; Arsenlis, A.; Bond, R. B.; Steinkamp, M. J.; Swaminarayan, S.; Womble, D. E. et al.
Object Type: Report
System: The UNT Digital Library
Optical Basicity and Nepheline Crystallization in High Alumina Glasses (open access)

Optical Basicity and Nepheline Crystallization in High Alumina Glasses

The purpose of this study was to find compositions that increase waste loading of high-alumina wastes beyond what is currently acceptable while avoiding crystallization of nepheline (NaAlSiO4) on slow cooling. Nepheline crystallization has been shown to have a large impact on the chemical durability of high-level waste glasses. It was hypothesized that there would be some composition regions where high-alumina would not result in nepheline crystal production, compositions not currently allowed by the nepheline discriminator. Optical basicity (OB) and the nepheline discriminator (ND) are two ways of describing a given complex glass composition. This report presents the theoretical and experimental basis for these models. They are being studied together in a quadrant system as metrics to explore nepheline crystallization and chemical durability as a function of waste glass composition. These metrics were calculated for glasses with existing data and also for theoretical glasses to explore nepheline formation in Quadrant IV (passes OB metric but fails ND metric), where glasses are presumed to have good chemical durability. Several of these compositions were chosen, and glasses were made to fill poorly represented regions in Quadrant IV. To evaluate nepheline formation and chemical durability of these glasses, quantitative X-ray diffraction (XRD) analysis and …
Date: February 25, 2011
Creator: Rodriguez, Carmen P.; McCloy, John S.; Schweiger, M. J.; Crum, Jarrod V. & Winschell, Abigail E.
Object Type: Report
System: The UNT Digital Library
Pressure-induced changes in the electronic structure of americium metal (open access)

Pressure-induced changes in the electronic structure of americium metal

We have conducted electronic-structure calculations for Am metal under pressure to investigate the behavior of the 5f-electron states. Density-functional theory (DFT) does not reproduce the experimental photoemission spectra for the ground-state phase where the 5f electrons are localized, but the theory is expected to be correct when 5f delocalization occurs under pressure. The DFT prediction is that peak structures of the 5f valence band will merge closer to the Fermi level during compression indicating presence of itinerant 5f electrons. Existence of such 5f bands is argued to be a prerequisite for the phase transitions, particularly to the primitive orthorhombic AmIV phase, but does not agree with modern dynamical-mean-field theory (DMFT) results. Our DFT model further suggests insignificant changes of the 5f valence under pressure in agreement with recent resonant x-ray emission spectroscopy, but in contradiction to the DMFT predictions. The influence of pressure on the 5f valency in the actinides is discussed and is shown to depend in a non-trivial fashion on 5f band position and occupation relative to the spd valence bands.
Date: February 25, 2011
Creator: Soderlind, P; Moore, K T; Landa, A & Bradley, J A
Object Type: Article
System: The UNT Digital Library
2010 Soil Characterization Report for the Area 11 Explosive Ordnance Disposal Unit, Nevada Test Site (open access)

2010 Soil Characterization Report for the Area 11 Explosive Ordnance Disposal Unit, Nevada Test Site

This soil characterization report summarizes sampling activities and analytical results, provides copies of laboratory data reports, and meets the requirements of Section IV.G.2 of the Permit (NEV HW0021, November 2005) and Sections P.3.d.7.b and P.3.n of the Permit Application (DOE/NV--1053-VOL 4, May 2005).
Date: February 25, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Acceleration of polarized protons in the AGS (open access)

Acceleration of polarized protons in the AGS

The high energy (s{sup 1/2} = 500 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the proton beam. With the AGS used as the pre-injector to RHIC, one of the main tasks is to preserve the polarization of the proton beam, during the beam acceleration in the AGS. The polarization preservation is accomplished by the two partial helical magnets [1,2,3,4,5,6,7] which have been installed in AGS, and help overcome the imperfection and the intrinsic spin resonances which occur during the acceleration of protons. This elimination of the intrinsic resonances is accomplished by placing the vertical tune Q{sub y} at a value close to 8.98, within the spin-tune stop-band created by the snake. At this near integer tune the perturbations caused by the partial helical magnets is large resulting in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have introduced compensation quads[2] in the AGS. In this paper we present the beam optics of the AGS which ameliorates this effect of the partial helices.
Date: February 25, 2010
Creator: Tsoupas, N.; Ahrens, L.; Bai, M.; Brown, K.; Courant, E.; Glenn, J. W. et al.
Object Type: Report
System: The UNT Digital Library
Activation Energy of Tantalum-Tungsten Oxide Thermite Reaction (open access)

Activation Energy of Tantalum-Tungsten Oxide Thermite Reaction

The activation energy of a high melting temperature sol-gel (SG) derived tantalum-tungsten oxide thermite composite was determined using the Kissinger isoconversion method. The SG derived powder was consolidated using the High Pressure Spark Plasma Sintering (HPSPS) technique to 300 and 400 C to produce pellets with dimensions of 5 mm diameter by 1.5 mm height. A custom built ignition setup was developed to measure ignition temperatures at high heating rates (500-2000 C {center_dot} min{sup -1}). Such heating rates were required in order to ignite the thermite composite. Unlike the 400 C samples, results show that the samples consolidated to 300 C undergo an abrupt change in temperature response prior to ignition. This change in temperature response has been attributed to the crystallization of the amorphous WO{sub 3} in the SG derived Ta-WO{sub 3} thermite composite and not to a pre-ignition reaction between the constituents. Ignition temperatures for the Ta-WO{sub 3} thermite ranged from approximately 465-670 C. The activation energy of the SG derived Ta-WO{sup 3} thermite composite consolidated to 300 and 400 C were determined to be 37.787 {+-} 1.58 kJ {center_dot} mol{sup -1} and 57.381 {+-} 2.26 kJ {center_dot} mol{sup -1}, respectively.
Date: February 25, 2010
Creator: Cervantes, O.; Kuntz, J.; Gash, A. & Munir, Z.
Object Type: Article
System: The UNT Digital Library
The AGS with four helical magnets (open access)

The AGS with four helical magnets

The idea of using multiple partial helical magnets was applied successfully to the AGS synchrotron, to preserve the proton beam polarization. In this paper we explore in details the idea of using four helical magnets placed symmetrically in the AGS ring. This modification provides many advantages over the present setup of the AGS that uses two partial helical magnets. First, it provides a larger 'spin tune gap' for the placement of the vertical betatron tune of the AGS during acceleration, second, the vertical spin direction during the beam injection and extraction is closer to vertical, third, the symmetric placement of the snakes allows for a better control of the AGS optics, and for reduced values of the beta and eta functions, especially near injection, fourth, the optical properties of the helical magnets also favor the placement of the horizontal betatron tune in the 'spin tune gap', thus eliminating the horizontal spin resonances. In this paper we provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and we compare these results with the present setup of the AGS that uses two partial helical magnets.
Date: February 25, 2010
Creator: Tsoupas, N.; Huang, H.; MacKay, W. W.; Roser, T. & Trbojevic, D.
Object Type: Report
System: The UNT Digital Library
Bunch length effects in the beam-beam compensation with an electron lens (open access)

Bunch length effects in the beam-beam compensation with an electron lens

Electron lenses for the head-on beam-beam compensation are under construction at the Relativistic Heavy Ion Collider. The bunch length is of the same order as the {beta}-function at the interaction point, and a proton passing through another proton bunch experiences a substantial phase shift which modifies the beam-beam interaction. We review the effect of the bunch length in the single pass beam-beam interaction, apply the same analysis to a proton passing through a long electron lens, and study the single pass beam-beam compensation with long bunches. We also discuss the beam-beam compensation of the electron beam in an electron-ion collider ring.
Date: February 25, 2010
Creator: Fischer, W.; Luo, Y. & Montag, C.
Object Type: Report
System: The UNT Digital Library
Characterization of LER propagation in resists: Underlayer interfaces in ultra-thin resist films (open access)

Characterization of LER propagation in resists: Underlayer interfaces in ultra-thin resist films

None
Date: February 25, 2010
Creator: Georege, Simi; Naulleau, Patrick; Krishnamoorthy, Ahila; Wu, Zeyu; Kennedy, Joseph; Rutter, Edward et al.
Object Type: Article
System: The UNT Digital Library
Exploratory Experimentation and Computation (open access)

Exploratory Experimentation and Computation

We believe the mathematical research community is facing a great challenge to re-evaluate the role of proof in light of recent developments. On one hand, the growing power of current computer systems, of modern mathematical computing packages, and of the growing capacity to data-mine on the Internet, has provided marvelous resources to the research mathematician. On the other hand, the enormous complexity of many modern capstone results such as the Poincare conjecture, Fermat's last theorem, and the classification of finite simple groups has raised questions as to how we can better ensure the integrity of modern mathematics. Yet as the need and prospects for inductive mathematics blossom, the requirement to ensure the role of proof is properly founded remains undiminished.
Date: February 25, 2010
Creator: Bailey, David H. & Borwein, Jonathan M.
Object Type: Report
System: The UNT Digital Library
Laser Ray Tracing in a Parallel Arbitrary Lagrangian Eulerian Adaptive Mesh Refinement Hydrocode (open access)

Laser Ray Tracing in a Parallel Arbitrary Lagrangian Eulerian Adaptive Mesh Refinement Hydrocode

None
Date: February 25, 2010
Creator: Masters, N D; Kaiser, T B; Anderson, R W; Eder, D C; Fisher, A C & Koniges, A E
Object Type: Article
System: The UNT Digital Library
Simulation of radio emission from air showers in atmospheric electric fields (open access)

Simulation of radio emission from air showers in atmospheric electric fields

We study the effect of atmospheric electric fields on the radio pulse emitted by cos- mic ray air showers. Under fair weather conditions the dominant part of the radio emission is driven by the geomagnetic field. When the shower charges are accelerated and deflected in an electric field additional radiation is emitted. We simulate this effect with the Monte Carlo code REAS2, using CORSIKA-simulated showers as input. In both codes a routine has been implemented that treats the effect of the electric field on the shower particles. We find that the radio pulse is significantly altered in background fields of the order of ~100 V/cm and higher. Practically, this means that air showers passing through thunderstorms emit radio pulses that are not a reliable measure for the shower energy. Under other weather circumstances significant electric field effects are expected to occur rarely, but nimbostratus clouds can harbor fields that are large enough. In general, the contribution of the electric field to the radio pulse has polarization properties that are different from the geomagnetic pulse. In order to filter out radio pulses that have been affected by electric field effects, radio air shower experiments should keep weatherinformation and perform full polarization …
Date: February 25, 2010
Creator: Buitink, S.; Huege, T.; Falcke, H & Kuijpers, J.
Object Type: Article
System: The UNT Digital Library
TRIMOLECULAR REACTIONS OF URANIUM HEXAFLUORIDE WITH WATER (open access)

TRIMOLECULAR REACTIONS OF URANIUM HEXAFLUORIDE WITH WATER

The hydrolysis reaction of uranium hexafluoride (UF{sub 6}) is a key step in the synthesis of uranium dioxide (UO{sub 2}) powder for nuclear fuels. Mechanisms for the hydrolysis reactions are studied here with density functional theory and the Stuttgart small-core scalar relativistic pseudopotential and associated basis set for uranium. The reaction of a single UF{sub 6} molecule with a water molecule in the gas phase has been previously predicted to proceed over a relatively sizeable barrier of 78.2 kJ {center_dot} mol{sup -1}, indicating this reaction is only feasible at elevated temperatures. Given the observed formation of a second morphology for the UO{sub 2} product coupled with the observations of rapid, spontaneous hydrolysis at ambient conditions, an alternate reaction pathway must exist. In the present work, two trimolecular hydrolysis mechanisms are studied with density functional theory: (1) the reaction between two UF{sub 6} molecules and one water molecule, and (2) the reaction of two water molecules with a single UF{sub 6} molecule. The predicted reaction of two UF{sub 6} molecules with one water molecule displays an interesting 'fluorine-shuttle' mechanism, a significant energy barrier of 69.0 kJ {center_dot} mol{sup -1} to the formation of UF{sub 5}OH, and an enthalpy of reaction ({Delta}H{sub …
Date: February 25, 2010
Creator: Westbrook, M.; Becnel, J. & Garrison, S.
Object Type: Article
System: The UNT Digital Library
The (3He,tf) as a surrogate reaction to determine (n,f) cross sections in the 10 to 20 MeV energy range (open access)

The (3He,tf) as a surrogate reaction to determine (n,f) cross sections in the 10 to 20 MeV energy range

The surrogate reaction 238U(3He,tf) is used to determine the 237Np(n,f) cross section indirectly over an equivalent neutron energy range from 10 to 20 MeV. A self-supporting ~;;761 mu g/cm2 metallic 238U foil was bombarded with a 42 MeV 3He2+ beam from the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory (LBNL). Outgoing charged particles and fission fragments were identified using the Silicon Telescope Array for Reaction Studies (STARS), consists of two 140 mu m and one 1000 mu m Micron S2 type silicon detectors. The 237Np(n,f) cross sections, determined indirectly, were compared with the 237Np(n,f) cross section data from direct measurements, the Evaluated Nuclear Data File (ENDF/B-VII.0), and the Japanese Evaluated Nuclear Data Library (JENDL 3.3) and found to closely follow those datasets. Use of the (3He,tf) reaction as a surrogate to extract (n,f) cross section in the 10 to 20 MeV equivalent neutron energy is found to be suitable.
Date: February 25, 2009
Creator: Basunia, M. S.; Clark, R. M.; Goldblum, B. L.; Bernstein, L. A.; Phair, L.; Burke, J. T. et al.
Object Type: Article
System: The UNT Digital Library
Alternate VHTR/HTE INterface for mitigating tritum. (open access)

Alternate VHTR/HTE INterface for mitigating tritum.

High temperature creep in structures at the interface between the nuclear plant and the hydrogen plant and the migration of tritium from the core through structures in the interface are two key challenges for the Very High Temperature Reactor (VHTR) coupled to the High Temperature Electrolysis (HTE) process. The severity of these challenges, however, can be reduced by lowering the temperature at which the interface operates. Preferably this should be accomplished in a way that does not reduce combined plant efficiency and other performance measures. A means for doing so is described in this report. A heat pump is used to raise the temperature of near-waste heat from the PCU to the temperature at which nine-tenths of the HTE process heat is needed. In addition to mitigating tritium transport and creep of structures, structural material commodity costs are reduced and plant efficiency is increased by a couple of percent.
Date: February 25, 2009
Creator: Vilim, R.
Object Type: Report
System: The UNT Digital Library