States

High-resolution simulations and modeling of reshocked single-mode Richtmyer-Meshkov instability. I. Comparison to experimental data and to amplitude growth model predictions (open access)

High-resolution simulations and modeling of reshocked single-mode Richtmyer-Meshkov instability. I. Comparison to experimental data and to amplitude growth model predictions

The reshocked single-mode Richtmyer-Meshkov instability is simulated in two spatial dimensions using the fifth- and ninth-order weighted essentially non-oscillatory shock-capturing method with uniform spatial resolution of 256 points per initial perturbation wavelength. The initial conditions and computational domain are modeled after the single-mode, Mach 1.21 air(acetone)/SF{sub 6} shock tube experiment of Collins and Jacobs [J. Fluid Mech. 464, 113 (2002)]. The simulation densities are shown to be in very good agreement with the corrected experimental planar laser-induced fluorescence images at selected times before reshock of the evolving interface. Analytical, semianalytical and phenomenological linear and nonlinear, impulsive, perturbation and potential flow models for single-mode Richtmyer-Meshkov unstable perturbation growth are summarized. The simulation amplitudes are shown to be in very good agreement with the experimental data and with the predictions of linear amplitude growth models for small times and with those of nonlinear amplitude growth models at later times up to the time at which the driver-based expansion in the experiment (but not present in the simulations or models) expands the layer before reshock. The qualitative and quantitative differences between the fifth- and ninth-order simulation results are discussed. Using a local and global quantitative metric, the prediction of the Zhang and Sohn …
Date: May 15, 2006
Creator: Latini, M; Schilling, O & Don, W
Object Type: Article
System: The UNT Digital Library
"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study" (open access)

"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study"

None
Date: May 12, 2006
Creator: McConnell, S
Object Type: Article
System: The UNT Digital Library
Statistical characterization of dislocation ensembles (open access)

Statistical characterization of dislocation ensembles

We outline a method to study the spatial and orientation statistics of dynamical dislocation systems by modeling the dislocations as a stochastic fiber process. Statistical measures have been introduced for the density, velocity, and flux of dislocations, and the connection between these measures and the dislocation state and plastic distortion rate in the crystal is explained. A dislocation dynamics simulation model has been used to extract numerical data to study the evolution of these statistical measures numerically in a body-centered cubic crystal under deformation. The orientation distribution of the dislocation density, velocity and dislocation flux, as well as the dislocation correlations have been computed. The importance of the statistical measures introduced here in building continuum models of dislocation systems is highlighted.
Date: May 17, 2006
Creator: El-Azab, A.; Deng, J. & Tang, M.
Object Type: Article
System: The UNT Digital Library
Completion Report for Well ER-12-4, Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain (includes Errata Sheet) (open access)

Completion Report for Well ER-12-4, Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain (includes Errata Sheet)

Well ER-12-4 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in May 2005, as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit in the north-central portion of the Nevada Test Site. The well is located on Rainier/Aqueduct Mesa, northwest of Yucca Flat, within Area 12 of the Nevada Test Site. The well provided information regarding the radiological and physical environment near underground nuclear tests conducted in U12t Tunnel, information on the pre-Tertiary rocks in the area, and depth to the regional water table.
Date: May 1, 2006
Creator: United States. National Nuclear Security Administration. Nevada Site Office.
Object Type: Report
System: The UNT Digital Library
Habitat Evaluation Procedures (HEP) Report : Ladd Marsh Wildlife Area, 2004-2006 Technical Report. (open access)

Habitat Evaluation Procedures (HEP) Report : Ladd Marsh Wildlife Area, 2004-2006 Technical Report.

The Regional HEP Team (RHT) and Oregon Department of Fish and Wildlife (ODFW) staff conducted a follow-up habitat evaluation procedures (HEP) analysis on the Ladd Marsh Wildlife Management Area (LMWA) in May 2005. The 2005 HEP assessment resulted in a total of 647.44 HUs, or 0.76 HUs/acre. This is an increase of 420.34 HUs (0.49 HUs/acre) over 2001 HEP survey results. The most significant increase in HUs occurred on the Wallender and Simonis parcels which increased by 214.30 HUs and 177.49 HUs respectively. Transects were established at or near 2001 HEP analysis transect locations whenever possible. ODFW staff biologists assisted the RHT re-establish transect locations and/or suggested areas for new surveys. Since 2001, significant changes in cover type acreage and/or structural conditions have occurred due to conversion of agriculture cover types to emergent wetland and grassland cover types. Agricultural lands were seeded to reestablish grasslands and wetlands were restored through active management and manipulation of extant water sources including natural stream hydrology/flood regimes and available irrigation. Grasslands increased on the Wallender parcel by 21% (65 acres), 23% (71 acres) at the Simonis site, and 39% (62 acres) at Conley Lake. The emergent wetland cover type also changed significantly increasing 60% …
Date: May 1, 2006
Creator: Ashley, Paul & Wagoner, Sara
Object Type: Report
System: The UNT Digital Library
Beyond Spin-Orbit: Probing Electron Correlation in the Pu 5f States (open access)

Beyond Spin-Orbit: Probing Electron Correlation in the Pu 5f States

Experiments planned to address the issue of electron correlation in the Pu 5f states are described herein. The key is the utilization of the Fano Effect, the observation of spin polarization in nonmagnetic systems, using chiral excitation such as circularly polarized X-rays.
Date: May 8, 2006
Creator: Tobin, J G
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for 132-D-2, 117-D Filter Building, Waste Site Reclassification Form 2005-024 (open access)

Remaining Sites Verification Package for 132-D-2, 117-D Filter Building, Waste Site Reclassification Form 2005-024

The 132-D-2 site (117-D Filter Building) and associated below-grade ductwork were decommissioned and demolished in two phases in 1985 and 1986, with a portion of the rubble left in situ beneath clean fill at least 1 m (3.3 ft) thick. Decommissioning included removal of contaminated equipment, including filters. Residual concentrations support future land uses that can be represented by a rural-residential scenario and pose no threat to groundwater or the Columbia River based on RESRAD modeling.
Date: May 9, 2006
Creator: Carlson, R. A.
Object Type: Report
System: The UNT Digital Library
Melting of bcc Transition Metals and Icosahedral Clustering (open access)

Melting of bcc Transition Metals and Icosahedral Clustering

In contrast to polyvalent metals, transition metals have low melting slopes(dT/dP) that are due to partially filled d-bands that allow for a lowering of liquid phase energy through s-d electron transfer and the formation of local structures. In the case of bcc transition metals we show the apparent discrepancy of DAC melting measurements with shock melting of Mo can be understood by reexamining the shock data for V and Ta and introducing the presence of an icosahedral short range order (ISRO) melt phase.
Date: May 26, 2006
Creator: Ross, M; Boehler, R & Japel, S
Object Type: Article
System: The UNT Digital Library
Holographic Grand Unification (open access)

Holographic Grand Unification

None
Date: May 7, 2006
Creator: Nomura, Yasunori; Poland, David & Tweedie, Brock
Object Type: Article
System: The UNT Digital Library
Final Work Plan for Targeted Sampling at Webber, Kansas. (open access)

Final Work Plan for Targeted Sampling at Webber, Kansas.

This Work Plan outlines the scope of work for targeted sampling at Webber, Kansas (Figure 1.1). This activity is being conducted at the request of the Kansas Department of Health and Environment (KDHE), in accordance with Section V of the Intergovernmental Agreement between the KDHE and the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). Data obtained in this sampling event will be used to (1) evaluate the current status of previously detected contamination at Webber and (2) determine whether the site requires further action. This work is being performed on behalf of the CCC/USDA by the Environmental Science Division of Argonne National Laboratory. Argonne is a nonprofit, multidisciplinary research center operated by the University of Chicago for the U.S. Department of Energy (DOE). The CCC/USDA has entered into an interagency agreement with DOE, under which Argonne provides technical assistance to the CCC/USDA with environmental site characterization and remediation at its former grain storage facilities. Argonne has issued a Master Work Plan (Argonne 2002) that describes the general scope of and guidance for all investigations at former CCC/USDA facilities in Kansas. The Master Work Plan, approved by the KDHE, contains the materials common to investigations at all locations …
Date: May 1, 2006
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Evaluation of 2004 Toyota Prius Hybrid Electric Drive System (open access)

Evaluation of 2004 Toyota Prius Hybrid Electric Drive System

The 2004 Toyota Prius is a hybrid automobile equipped with a gasoline engine and a battery- and generator-powered electric motor. Both of these motive-power sources are capable of providing mechanical-drive power for the vehicle. The engine can deliver a peak-power output of 57 kilowatts (kW) at 5000 revolutions per minute (rpm) while the motor can deliver a peak-power output of 50 kW over the speed range of 1200-1540 rpm. Together, this engine-motor combination has a specified peak-power output of 82 kW at a vehicle speed of 85 kilometers per hour (km/h). In operation, the 2004 Prius exhibits superior fuel economy compared to conventionally powered automobiles. To acquire knowledge and thereby improve understanding of the propulsion technology used in the 2004 Prius, a full range of design characterization studies were conducted to evaluate the electrical and mechanical characteristics of the 2004 Prius and its hybrid electric drive system. These characterization studies included (1) a design review, (2) a packaging and fabrication assessment, (3) bench-top electrical tests, (4) back-electromotive force (emf) and locked rotor tests, (5) loss tests, (6) thermal tests at elevated temperatures, and most recently (7) full-design-range performance testing in a controlled laboratory environment. This final test effectively mapped the …
Date: May 1, 2006
Creator: Staunton, Robert H; Ayers, Curtis William; Chiasson, J. N.; Burress, Timothy A & Marlino, Laura D
Object Type: Report
System: The UNT Digital Library
The Role of Emerging Technologies in Improving Energy Efficiency:Examples from the Food Processing Industry (open access)

The Role of Emerging Technologies in Improving Energy Efficiency:Examples from the Food Processing Industry

None
Date: May 1, 2006
Creator: Lung, Robert Bruce; Masanet, Eric & McKane, Aimee
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for 132-D-3, 1608-D Effluent Pumping Station, Waste Site Reclassification Form 2005-033 (open access)

Remaining Sites Verification Package for 132-D-3, 1608-D Effluent Pumping Station, Waste Site Reclassification Form 2005-033

Decommissioning and demolition of the 132-D-3 site, 1608-D Effluent Pumping Station was performed in 1986. Decommissioning included removal of equipment, water, and sludge for disposal as radioactive waste. The at- and below-grade structure was demolished to at least 1 m below grade and the resulting rubble buried in situ. The area was backfilled to grade with at least 1 m of clean fill and contoured to the surrounding terrain. Residual concentrations support future land uses that can be represented by a rural-residential scenario and pose no threat to groundwater or the Columbia River based on RESRAD modeling.
Date: May 9, 2006
Creator: Carlson, R. A.
Object Type: Report
System: The UNT Digital Library
Towards an Accurate Performance Modeling of Parallel SparseFactorization (open access)

Towards an Accurate Performance Modeling of Parallel SparseFactorization

We present a performance model to analyze a parallel sparseLU factorization algorithm on modern cached-based, high-end parallelarchitectures. Our model characterizes the algorithmic behavior bytakingaccount the underlying processor speed, memory system performance, aswell as the interconnect speed. The model is validated using theSuperLU_DIST linear system solver, the sparse matrices from realapplications, and an IBM POWER3 parallel machine. Our modelingmethodology can be easily adapted to study performance of other types ofsparse factorizations, such as Cholesky or QR.
Date: May 26, 2006
Creator: Grigori, Laura & Li, Xiaoye S.
Object Type: Article
System: The UNT Digital Library
Mesoscale modeling of irreversible volume growth in powders of anisotropic crystals (open access)

Mesoscale modeling of irreversible volume growth in powders of anisotropic crystals

Careful thermometric analysis (TMA) on powders of micron-sized triamino-trinitrobenzene (TATB) crystallites are shown to display irreversible growth in volume when subjected to repeated cycles of heating and cooling. Such behavior is counter-intuitive to typical materials response to simulated annealing cycles in atomic-scale molecular dynamics. However, through coarse-grained simulations using a mesoscale Hamiltonian we quantitatively reproduce irreversible growth behavior in such powdered material. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy, and is mediated by particles much smaller than the average crystallite size.
Date: May 5, 2006
Creator: Gee, R.; Maiti, A. & Fried, L.
Object Type: Article
System: The UNT Digital Library
Transmission electron microscopy of actinide materials (open access)

Transmission electron microscopy of actinide materials

Actinide metallurgy, crystallography, physics, and chemistry are of great interest due to the unique behavior of the 5f states that dominate the electronic structure. The 5f states produce a wide range of fascinating behaviors in the actinide materials. from superconductivity to exotic magnetism. Accordingly, they are of great interest, but are difficult to work with. Transmission electron microscopy (TEM) can overcome many of the problems of working with actinide materials and can be used to interrogate the atomic and electronic structure of actinide materials. We will cover our capabilities at LLNL: Sample preparation; TEM techniques; and in situ capabilities.
Date: May 30, 2006
Creator: Moore, K
Object Type: Article
System: The UNT Digital Library
Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Eastern Gulf Costal Plain (open access)

Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Eastern Gulf Costal Plain

Pruet Production Co. and the Center for Sedimentary Basin Studies at the University of Alabama, in cooperation with Texas A&M University, Mississippi State University, University of Mississippi, and Wayne Stafford and Associates proposed a three-phase, focused, comprehensive, integrated and multidisciplinary study of Upper Jurassic Smackover carbonates (Class II Reservoir), involving reservoir characterization and 3-D modeling (Phase I) and a field demonstration project (Phases II and III) at Womack Hill Field Unit, Choctaw and Clarke Counties, Alabama, eastern Gulf Coastal Plain. Phase I of the project has been completed. The principal objectives of the project are: increasing the productivity and profitability of the Womack Hill Field Unit, thereby extending the economic life of this Class II Reservoir and transferring effectively and in a timely manner the knowledge gained and technology developed from this project to producers who are operating other domestic fields with Class II Reservoirs. The major tasks of the project included reservoir characterization, recovery technology analysis, recovery technology evaluation, and the decision to implement a demonstration project. Reservoir characterization consisted of geoscientific reservoir characterization, petrophysical and engineering property characterization, microbial characterization, and integration of the characterization data. Recovery technology analysis included 3-D geologic modeling, reservoir simulation, and microbial core …
Date: May 31, 2006
Creator: Mancini, Ernest A.
Object Type: Report
System: The UNT Digital Library
Target Plate Conditions During Stochastic Boundary Operation on DIII-D (open access)

Target Plate Conditions During Stochastic Boundary Operation on DIII-D

A major concern for large tokamaks like ITER is the presence of edge localized modes (ELMs) that repeatedly send large bursts of particles and heat into the divertor plates. Operation with resonant magnetic perturbations (RMP) at the boundary of DIII=D has suppressed ELMs for values of q95 {approx} 3.7. At the target plate, the conditions during ELM suppressed operation for both high and low collisionality are observed by a set of radially distributed Langmuir probes. At high collisionality (n*{approx}1), the target plate particle flux and temperature drops by > 30% during ELM suppression. At low collisionality (n*{approx}0.1), the core density, target plate density, and target plate particle flux drop but the plate electron temperature increases after the ELMs are suppressed. The ELM-suppressed target plate heat flux is nearly the same as the heat flux between ELMs but the (5X higher) transient heat flux peaks due to ELMs are eliminated.
Date: May 15, 2006
Creator: Watkins, J; Evans, T; Moyer, R; Lasnier, C & Rudakov, D
Object Type: Article
System: The UNT Digital Library
Experimental and Numerical Studies of Separatrix Splitting and Magnetic Footprints in DIII-D (open access)

Experimental and Numerical Studies of Separatrix Splitting and Magnetic Footprints in DIII-D

A numerical field line integration code is used to study the structure of divertor footprints produced by small non-axisymmetric magnetic perturbation in the DIII-D tokamak. The numerical modeling results are compared to experimental infrared camera data which show a splitting of the divertor target plate heat flux into several distinct peaks when an n=3 magnetic perturbation from the DIII-D I-coil is applied. The heat flux splitting consistently appears when the n=3 perturbation is applied and disappears when the perturbation is removed. The magnitude of the splitting implied by the numerical modeling is a factor of 3 smaller than the splitting seen in the experimental data. These results suggest that the plasma response to the edge resonant applied n=3 magnetic perturbation produces an amplification of the vacuum magnetic footprint structure on the divertor target plates. These results may have significant implications for the ITER divertor design.
Date: May 15, 2006
Creator: Evans, T; Joseph, I; Moyer, R; Fenstermacher, M; Lasnier, C & Yan, L
Object Type: Article
System: The UNT Digital Library
Application of the TraPPE force field to predicting isothermal pressure-volume curves at high pressures and high temperatures (open access)

Application of the TraPPE force field to predicting isothermal pressure-volume curves at high pressures and high temperatures

Knowledge of the thermophysical properties of materials at extreme pressure and temperature conditions is essential for improving our understanding of many planetary and detonation processes. Significant gaps in what is known about the behavior of materials at high density and high temperature exist, largely due to the limitations and dangers of performing experiments at the necessary extreme conditions. Modeling these systems through the use of equations of state and particle-based simulation methods significantly extends the range of pressures and temperatures that can be safely studied. The reliability of such calculations depends on the accuracy of the models used. Here we present an assessment of the united-atom version of the TraPPE (Transferable Potentials for Phase Equilibria) force field and single-site exp-6 representations for methane, methanol, oxygen, and ammonia at extreme conditions. As shown by Monte Carlo simulations in the isobaric-isothermal ensemble, the TraPPE models, despite being parameterized to the vapor-liquid coexistence curve (i.e. relatively mild conditions), perform remarkably well in the high pressure/high temperature regime. The single-site exp-6 models can fit experimental data in the high pressure/temperature regime very well, but the parameters are less transferable to ambient conditions.
Date: May 19, 2006
Creator: Eggimann, B L; Siepmann, J I & Fried, L E
Object Type: Article
System: The UNT Digital Library
TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost (open access)

TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost

We use TOUGH+/GasH2O to study the effects of a heat sourceburied in the Martian permafrost to evaluate the possibility ofestablishing a wet zone of liquid water, in which terrestrialmicroorganisms could survive and multiply. Analysis of the problemindicates that (1) only a limited permafrost volume (not exceeding 0.35 min radius) is affected, (2) a "wet" zone with limited amounts of liquidwater de-velops (not exceeding 8 and 0.7 kg for a 250 W and a 62.5 Wsource, respectively), (3) the wet zone per-sists for a long time,becomes practically stationary after t = 20 sols because of venting intothe Martian atmosphere, and its thickness is limited and decreases slowlyover time, (4) a "dry" zone (where SG>0.9) evolves, continues toexpand (albeit slowly) with time, but its extent remains limited, and (5)the ice front surrounding the wet zone is self-sharpening. For a range ofinitial conditions investigated, evolution of the liquid water massoccurs at approximately the same rate, reaches roughly the same maximum,and occurs at about the same time (10 to 20 sols; 1 sol = 24.39hours).
Date: May 12, 2006
Creator: Moridis, George J. & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
U.S. Aims for Zero-Energy: Support for PV on New Homes (open access)

U.S. Aims for Zero-Energy: Support for PV on New Homes

As a market segment for solar photovoltaic (PV) adoption, new homes have a number of attractive attributes. Homebuyers can easily roll the cost of the PV system into their mortgage and, with rebates or other financial incentives, potentially realize an immediate net positive cash flow from the investment. PV system performance can be optimized by taking roof orientation, shading, and other structural factors into account in the design of new homes. Building-integrated photovoltaics (BIPV), which are subject to fewer aesthetic concerns than traditional, rack-mounted systems, are well-suited to new construction applications. In large new residential developments, costs can be reduced through bulk purchases and scale economies in system design and installation. Finally, the ability to install PV as a standard feature in new developments - like common household appliances - creates an opportunity to circumvent the high transaction costs and other barriers typically confronted when each individual homeowner must make a distinct PV purchase decision.
Date: May 11, 2006
Creator: Barbose, Galen; Wiser, Ryan & Bolinger, Mark
Object Type: Article
System: The UNT Digital Library
Toroidally Asymmetric Distributions of Hydrocarbon (CD) Emission and Chemical Sputtering Sources in DIII-D (open access)

Toroidally Asymmetric Distributions of Hydrocarbon (CD) Emission and Chemical Sputtering Sources in DIII-D

Measurements in DIII-D show that the carbon chemical sputtering sources along the inner divertor and center post are toroidally periodic and highest at the upstream tile edge. Imaging with a tangentially viewing camera and visible spectroscopy were used to monitor the emission from molecular hydrocarbons (CH/CD) at 430.8 nm and deuterium neutrals in attached and partially detached divertors of low-confinement mode plasmas. In contrast to the toroidally periodic CD distribution, emission from deuterium neutrals was observed to be toroidally symmetric along the inner strike zone. The toroidal distribution of the measured tile surface temperature in the inner divertor correlates with that of the CD emission, suggesting larger parallel particle and heat fluxes to the upstream tile edge, either due to toroidal tile gaps or height steps between adjacent tiles.
Date: May 16, 2006
Creator: Groth, M.; Brooks, N. H.; Fenstermacher, M. E.; Lasnier, C. J.; McLean, A. G. & Watkins, J. G.
Object Type: Article
System: The UNT Digital Library
The California Greenhouse Gas Initiative and Its Implications to the Automotive Industry (open access)

The California Greenhouse Gas Initiative and Its Implications to the Automotive Industry

CAR undertook this investigation to better understand the costs and challenges of a local (state) regulation necessitating the implementation of alternative or advanced powertrain technology. CAR will attempt to add insight into the challenges that local regulations present to the automotive industry, and to contribute further to the discussion of how advanced powertrain technology may be used to meet such regulation. Any local law that (directly or indirectly) affects light duty motor vehicle fuel economy creates what in effect is a specialty market for powertrain technology. As such these small markets present significant challenges for automotive manufacturers. First, a small market with unique standards presents significant challenges to an industry that has sustained growth by relying on large volumes to achieve scale economies and deliver products at a cost acceptable to the consumer. Further, the challenges of the additional technology make it likely that any powertrain capable of meeting the stringent emissions standards will include costly additional components, and thus will be more costly to manufacture. It is likely that manufacturers would consider the following actions as steps to deliver products to meet the pending California regulatory requirements anticipated as a result of prior California legislation: (1) Substituting more fuel …
Date: May 31, 2006
Creator: Smith, B. C.; Miller, R. T. & Research, Center for Automotive
Object Type: Report
System: The UNT Digital Library