Thermal Cook-off of an HMX Based Explosive: Pressure Gauge Experiments and Modeling (open access)

Thermal Cook-off of an HMX Based Explosive: Pressure Gauge Experiments and Modeling

Safety issues related to thermal cook-off are important for handling and storing explosive devices. Violence of event as a function of confinement is important for prediction of collateral events. There are major issues, which require an understanding of the following events: (1) transit to detonation of a pressure wave from a cook-off event, (2) sensitivity of HMX based explosives changes with thermally induced phase transitions and (3) the potential danger of neighboring explosive devices being affected by a cook-off reaction. Results of cook-off events of known size, confinement and thermal history allows for development and/or calibrating computer models for calculating events that are difficult to measure experimentally.
Date: April 2, 2002
Creator: Urtiew, P A; Forbes, J W; Tarver, C M; Garcia, F; Greenwood, D W & Vandersall, K S
Object Type: Article
System: The UNT Digital Library
Interpreting Mammalian Evolution using Fugu Genome Comparisons (open access)

Interpreting Mammalian Evolution using Fugu Genome Comparisons

Comparative sequence analysis of the human and the pufferfish Fugu rubripes (fugu) genomes has revealed several novel functional coding and noncoding regions in the human genome. In particular, the fugu genome has been extremely valuable for identifying transcriptional regulatory elements in human loci harboring unusually high levels of evolutionary conservation to rodent genomes. In such regions, the large evolutionary distance between human and fishes provides an additional filter through which functional noncoding elements can be detected with high efficiency.
Date: April 2, 2004
Creator: Stubbs, L; Ovcharenko, I & Loots, G G
Object Type: Article
System: The UNT Digital Library
A Crystal Level Model for Phase Transformation Allowing for Large Volume Changes (open access)

A Crystal Level Model for Phase Transformation Allowing for Large Volume Changes

We present a model for materials undergoing diffusionless structural changes including martensitic phase transformation and twinning, with the phase transformations involving large volume changes. Within a given material element, structural changes induce mass fraction rates between the constituents in the material. Deformation results from both these structural changes and elasto-viscoplastic deformation of the constituents themselves.
Date: April 2, 2003
Creator: Barton, N R; Benson, D J & Becker, R
Object Type: Article
System: The UNT Digital Library
Post-Closure Groundwater Monitoring Plan for the 1324-N Surface Impoundment and 1324-NA Percolation Pond (open access)

Post-Closure Groundwater Monitoring Plan for the 1324-N Surface Impoundment and 1324-NA Percolation Pond

The 1324-N Surface Impoundment and the 1324-NA Percolation Pond, located in the 100-N Area of the Hanford Site, are regulated under the Resource Consevation and Recovery Act (RCRA). Surface and underground features of the facilities have been removed and laboratory analyses showed that soil met the closure performance standards. These sites have been backfilled and revegetated.
Date: April 2, 2004
Creator: Hartman, Mary J.
Object Type: Report
System: The UNT Digital Library
Damage Mechanisms of Filled Siloxanes for Predictive Multiscale Modeling of Aging Behavior (open access)

Damage Mechanisms of Filled Siloxanes for Predictive Multiscale Modeling of Aging Behavior

Predictions of component performance versus lifetime are often risky for complex materials in which there may be many underlying aging or degradation mechanisms. In order to develop more accurate predictive models for silica-filled siloxane components, we are studying damage mechanisms over a broad range of size domains, linked together through several modeling efforts. Atomistic and molecular dynamic modeling has elucidated the chemistry of the silica filler to polymer interaction, as this interaction plays a key role in this material's aging behavior. This modeling work has been supported by experimental data on the removal of water from the silica surface, the effect of the surrounding polymer on this desiccation, and on the subsequent change in the mechanical properties of the system. Solid State NMR efforts have characterized the evolution of the polymer and filler dynamics as the material is damaged through irradiation or desiccation. These damage signatures have been confirmed by direct measurements of changes in polymer crosslink density and filler interaction as measured by solvent swelling, and by mechanical property tests. Data from the changes at these molecular levels are simultaneously feeding the development of age-aware constitutive models for polymer behavior. In addition, the microstructure of the foam, including under …
Date: April 2, 2002
Creator: Balazs, B; Maxwell, R; de Teresa, S; Dinh, L & Gee, R
Object Type: Article
System: The UNT Digital Library
A Modeling Approach for Burn Scar Assessment Using Natural Features and Elastic Property (open access)

A Modeling Approach for Burn Scar Assessment Using Natural Features and Elastic Property

A modeling approach is presented for quantitative burn scar assessment. Emphases are given to: (1) constructing a finite element model from natural image features with an adaptive mesh, and (2) quantifying the Young's modulus of scars using the finite element model and the regularization method. A set of natural point features is extracted from the images of burn patients. A Delaunay triangle mesh is then generated that adapts to the point features. A 3D finite element model is built on top of the mesh with the aid of range images providing the depth information. The Young's modulus of scars is quantified with a simplified regularization functional, assuming that the knowledge of scar's geometry is available. The consistency between the Relative Elasticity Index and the physician's rating based on the Vancouver Scale (a relative scale used to rate burn scars) indicates that the proposed modeling approach has high potentials for image-based quantitative burn scar assessment.
Date: April 2, 2004
Creator: Tsap, L V; Zhang, Y; Goldgof, D B & Sarkar, S
Object Type: Article
System: The UNT Digital Library
Experimental Results in Support of Simulating Progressive Crush in Carbon-Fiber Textile Composites (open access)

Experimental Results in Support of Simulating Progressive Crush in Carbon-Fiber Textile Composites

This report summarizes the findings of an experimental program conducted to support the modeling of the crush behavior of triaxial braid carbon fiber composites. The matrix material as well as braided panels and tubes were characterized in order to determine material properties, to assess failure modes, and to provide a test bed for new analytical and numerical tools developed specifically for braided composites. The matrix material selected by the ACC was an epoxy vinyl ester (Ashland Hetron 922). Tensile tests were used to compare two formulations-one used by the ACC and one recommended by the resin supplier. The latter was a faster reacting system and gelled in one-third the time of the ACC formulation. Both formulations had an average elongation at failure that was only half of the resin supplier's reported value. Only one specimen of each type came close to the reported elongation value and it was shown that failure invariably initiated at both surface and internal defects. Overall, the tensile properties of the two formulations were nearly identical, but those of the ACC system were more consistent. The properties of the ACC matrix formulation were measured in tension, shear, and compression and the average properties obtained in these …
Date: April 2, 2001
Creator: DeTeresa, S J; Allison, L M; Cunningham, B J; Freeman, DC; Saculla, M D; Sanchez, R J et al.
Object Type: Report
System: The UNT Digital Library
Time-Accurate Computation of Viscous Flow Around Deforming Bodies Using Overset Grids (open access)

Time-Accurate Computation of Viscous Flow Around Deforming Bodies Using Overset Grids

Dynamically evolving boundaries and deforming bodies interacting with a flow are commonly encountered in fluid dynamics. However, the numerical simulation of flows with dynamic boundaries is difficult with current methods. We propose a new method for studying such problems. The key idea is to use the overset grid method with a thin, body-fitted grid near the deforming boundary, while using fixed Cartesian grids to cover most of the computational domain. Our approach combines the strengths of earlier moving overset grid methods for rigid body motion, and unstructured grid methods for Aow-structure interactions. Large scale deformation of the flow boundaries can be handled without a global regridding, and in a computationally efficient way. In terms of computational cost, even a full overset grid regridding is significantly cheaper than a full regridding of an unstructured grid for the same domain, especially in three dimensions. Numerical studies are used to verify accuracy and convergence of our flow solver. As a computational example, we consider two-dimensional incompressible flow past a flexible filament with prescribed dynamics.
Date: April 2, 2001
Creator: Fast, P & Henshaw, W D
Object Type: Article
System: The UNT Digital Library
A Measurement Technique to Determine the Sensitivity of Trained Dogs to Explosive Vapor Concentration (open access)

A Measurement Technique to Determine the Sensitivity of Trained Dogs to Explosive Vapor Concentration

Over the years canines have been used successfully to detect explosives. However, exactly what a canine detects in the many thousands of explosive formulations available is still not well understood. LLNL and Bureau of Alcohol, Tobacco and Firearms (BATF) studies over the past four years are beginning to provide better insight into this complex problem. One area that has been addressed is how low a molecular concentration of nitromethane explosive can a canine detect. Forty-one canine/handler teams were used in four test series with arrays containing dilute nitromethane-in-water solutions. (The canines had been trained on the amount of nitromethane vapor in equilibrium with the undiluted liquid explosive.) By diluting liquid nitromethane with water, the amount of explosive vapor can be reduced many orders of magnitude to test the lower limit of the canine's nitromethane vapor detection response. The results are summarized in the table in Appendix A. The probability of detecting nitromethane remained high until the vapor pressure fell below {approx} 1 x 10{sup 6} microns (one nitromethane molecule in a trillion nitrogen, oxygen and water molecules). This report describes a new approach to measuring this lower limit of detection using the diffusion of nitromethane in various length tubes containing …
Date: April 2, 2002
Creator: Reaugh, J E & Kury, J W
Object Type: Report
System: The UNT Digital Library
Stability and Thermal Equilibrium in CICC (open access)

Stability and Thermal Equilibrium in CICC

The stability of modern superconductors depends not only on the cooling and the amount of copper in the cross section of the strands but also on the smoothness of the transition from the superconducting into the normal state. Frequently the latter factor is much more important than the cooling and the copper content. Superconductors with a broad transition are more stable and easier to control than the superconductors with a sharp transition, although the price for better stability might be somewhat lower operating current. The paper gives thermal equilibrium equations and stability criteria against small perturbations and determines the ultimate current that could be reached by a CICC depending on operating conditions. The effects of various factors (e.g., magnetic field profile, mass flow and smoothness of the transition to normal state) on the thermal equilibrium and ultimate current: are studied and discussed.
Date: April 2, 2003
Creator: Martovetsky, N. N.
Object Type: Article
System: The UNT Digital Library
Global Ocean Storage of Anthropogenic Carbon (GOSAC) (open access)

Global Ocean Storage of Anthropogenic Carbon (GOSAC)

GOSAC was an EC-funded project (1998-2001) focused on improving the predictive capacity and accelerating development of global-scale, three-dimensional, ocean carbon-cycle models by means of standardized model evaluation and model intercomparison. Through the EC Environment and Climate Programme, GOSAC supported the participation of seven European modeling groups in the second phase of the larger international effort OCMIP (the Ocean Carbon-Cycle Model Intercomparison Project). OCMIP included model comparison and validation for both CO{sub 2} and other ocean circulation and biogeochemical tracers. Beyond the international OCMIP effort, GOSAC also supported the same EC ocean carbon cycle modeling groups to make simulations to evaluate the efficiency of purposeful sequestration of CO{sub 2} in the ocean. Such sequestration, below the thermocline has been proposed as a strategy to help mitigate the increase of CO{sub 2} in the atmosphere. Some technical and scientific highlights of GOSAC are given.
Date: April 2, 2002
Creator: Orr, J C
Object Type: Report
System: The UNT Digital Library
Hydrothermal Alteration Mineral Mapping Using Hyperspectral Imagery in Dixie Valley, Nevada (open access)

Hydrothermal Alteration Mineral Mapping Using Hyperspectral Imagery in Dixie Valley, Nevada

Hyperspectral (HyMap) data was used to map the location of outcrops of high temperature, hydrothermally alterated minerals (including alunite, pyrophyllite, and hematite) along a 15 km swath of the eastern front of the Stillwater Mountain Range in Dixie Valley, Nevada. Analysis of this data set reveals that several outcrops of these altered minerals exist in the area, and that one outcrop, roughly 1 square kilometer in area, shows abundant high temperature alteration. Structural analysis of the altered region using a Digital Elevation Model (DEM) suggests that this outcrop is bounded on all sides by a set of cross-cutting faults. This fault set lies within the Dixie Valley Fault system (Caskey et al. 1996). Both the intense alteration in this area and the presence of cross-cutting faults indicate a high probability of recent hot fluid escape.
Date: April 2, 2004
Creator: Kennedy-Bowdoin, T.; Martini, B. A.; Silver, E. A. & Pickles, W. L.
Object Type: Article
System: The UNT Digital Library
Quantitative Estimation of Trace Chemicals in Industrial Effluents with the Sticklet Transform Method (open access)

Quantitative Estimation of Trace Chemicals in Industrial Effluents with the Sticklet Transform Method

Application of a novel transform operator, the Sticklet transform, to the quantitative estimation of trace chemicals in industrial effluent plumes is reported. The sticklet transform is a superset of the well-known derivative operator and the Haar wavelet, and is characterized by independently adjustable lobe width and separation. Computer simulations demonstrate that they can make accurate and robust concentration estimates of multiple chemical species in industrial effluent plumes in the presence of strong clutter background, interferent chemicals and random noise. In this paper they address the application of the sticklet transform in estimating chemical concentrations in effluent plumes in the presence of atmospheric transmission effects. They show that this transform retains the ability to yield accurate estimates using on-plume/off-plume measurements that represent atmospheric differentials up to 10% of the full atmospheric attenuation.
Date: April 2, 2001
Creator: Mehta, N C; Scharlemann, E T & Stevens, C G
Object Type: Article
System: The UNT Digital Library
Science and Technology Review May 2004 (open access)

Science and Technology Review May 2004

This month's issue has the following articles: (1) ''A Multidisciplinary Attack on Bioterrorism''--Commentary by Tomas Diaz de la Rubia. (2) ''Life at the Nanoscale''--Livermore researchers are exploring the molecules of life at the nanoscale to fight bioterrorism, improve human health, and understand how proteins function. (3) ''Screening Cargo Containers to Remove a Terrorist Threat''--A detection system for cargo containers will search for hidden nuclear materials that terrorists might try to ship to U.S. seaports. (4) ''Improved Algorithms Speed It Up for Codes''--Recent changes to the algorithms used in Monte Carlo calculations are reducing the time needed to run the high-fidelity simulations being developed for the nation's supercomputers. (5) ''The Siren Call of the Seas: Sequestering Carbon Dioxide''--Scientists at Livermore evaluate possible methods for removing carbon dioxide from Earth's atmosphere and storing it in the planet's waters.
Date: April 2, 2004
Creator: Henson, V E
Object Type: Report
System: The UNT Digital Library
Efficient traffic grooming in SONET/WDM BLSR Networks (open access)

Efficient traffic grooming in SONET/WDM BLSR Networks

In this paper, we study traffic grooming in SONET/WDM BLSR networks under the uniform all-to-all traffic model with an objective to reduce total network costs (wavelength and electronic multiplexing costs), in particular, to minimize the number of ADMs while using the optimal number of wavelengths. We derive a new tighter lower bound for the number of wavelengths when the number of nodes is a multiple of 4. We show that this lower bound is achievable. All previous ADM lower bounds except perhaps that in were derived under the assumption that the magnitude of the traffic streams (r) is one unit (r = 1) with respect to the wavelength capacity granularity g. We then derive new, more general and tighter lower bounds for the number of ADMs subject to that the optimal number of wavelengths is used, and propose heuristic algorithms (circle construction algorithm and circle grooming algorithm) that try to minimize the number of ADMs while using the optimal number of wavelengths in BLSR networks. Both the bounds and algorithms are applicable to any value of r and for different wavelength granularity g. Performance evaluation shows that wherever applicable, our lower bounds are at least as good as existing bounds …
Date: April 2, 2004
Creator: Awwal, Abdul S.; Billah, Abdur R. B. & Wang, Bin
Object Type: Article
System: The UNT Digital Library
Year 6 Post-Remediation Biomonitoring and Phase II Source Investigation at the United Heckathorn Superfund Site, Richmond, California (open access)

Year 6 Post-Remediation Biomonitoring and Phase II Source Investigation at the United Heckathorn Superfund Site, Richmond, California

The Heckathorn Superfund Site in Richmond, California, encompasses the property of the former United Heckathorn pesticide packaging plant and the adjacent waterway, Lauritzen Channel. The site was used from 1945 to 1966 by several operators to produce various agricultural chemicals. The site was placed on the National Priorities List of Superfund sites in 1990, which resulted in the removal of pesticide-contaminated soil from the upland portion of the site and dredging the marine portion of the site. Post-remediation marine monitoring and associated studies conducted through 2002 indicate that the contamination in the channel continues to pose a significant risk to biota and human health. This report documents continued marine monitoring and source investigation studies conducted in 2003.
Date: April 2, 2004
Creator: Kohn, Nancy P. & Evans, Nathan R.
Object Type: Report
System: The UNT Digital Library
Texas Disease Prevention News, Volume 61, Number 8, April 2001 (open access)

Texas Disease Prevention News, Volume 61, Number 8, April 2001

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.
Date: April 2, 2001
Creator: Texas. Department of Health.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
THE SIMULATION OF FINE SCALE NOCTURNAL BOUNDARY LAYER MOTIONS WITH A MESO-SCALE ATMOSPHERIC MODEL (open access)

THE SIMULATION OF FINE SCALE NOCTURNAL BOUNDARY LAYER MOTIONS WITH A MESO-SCALE ATMOSPHERIC MODEL

A field project over the Atmospheric Radiation Measurement-Clouds and Radiation Testbed (ARM-CART) site during a period of several nights in September, 2007 was conducted to explore the evolution of the low-level jet (LLJ). Data was collected from a tower and a sodar and analyzed for turbulent behavior. To study the full range of nocturnal boundary layer (NBL) behavior, the Regional Atmospheric Modeling System (RAMS) was used to simulate the ARM-CART NBL field experiment and validated against the data collected from the site. This model was run at high resolution, and is ideal for calculating the interactions among the various motions within the boundary layer and their influence on the surface. The model reproduces adequately the synoptic situation and the formation and dissolution cycles of the low-level jet, although it suffers from insufficient cloud production and excessive nocturnal cooling. The authors suggest that observed heat flux data may further improve the realism of the simulations both in the cloud formation and in the jet characteristics. In a higher resolution simulation, the NBL experiences motion on a range of timescales as revealed by a wavelet analysis, and these are affected by the presence of the LLJ. The model can therefore be used …
Date: April 2, 2009
Creator: Werth, D.; Kurzeja, R. & Parker, M.
Object Type: Article
System: The UNT Digital Library
Water Velocity Measurement on an Extended-Length Submerged Bar Screen at John Day Dam (open access)

Water Velocity Measurement on an Extended-Length Submerged Bar Screen at John Day Dam

This report describes a study of water velocity around an extended-length submerged bar screen (ESBS) at John Day Dam. The study was conducted for the U.S. Army Corps of Engineers by AScI Corporation and MEVATEC Corporation in March of 2000. This report was prepared by Pacific Northwest National Laboratory. ESBS are being studied as one method for diverting juvenile migrating fish from the dam's turbine intakes into the gate well and through the juvenile fish bypass channels.
Date: April 2, 2001
Creator: Weiland, Mark A. & Escher, Charles
Object Type: Report
System: The UNT Digital Library
Caution -- Beam Crossing Ahead (open access)

Caution -- Beam Crossing Ahead

There are times when a laser beam needs to cross between tables or even go from one room to another. This presents an interesting traffic-flow and safety challenge to both the laser safety officer and laser user. Fortunately it is a challenge that has several solutions But the simplest solution may not be the best one. For example, the simplest way to get a beam from one optical table to another is just to put a sturdy tube around it. That's a permanent solution, and it completely contains the laser beam. While this is laser safe, there can be egress issues if it blocks a walkway. One comment this author often hears is, 'We can just duck under the tube.' The fire marshal, as well as the laser safety officer, might have issues with this. Especially in the case of a darkened lab, a blocked walkway can present a hazard of its own. One good solution is to transport the beam from Point A to Point B through a fiberoptic cable, when that is possible. One should easily be able to run the fiber up and over any walkway or down through a conduit on the floor. An important concern …
Date: April 2, 2008
Creator: Barat, Kenneth L.
Object Type: Article
System: The UNT Digital Library
PNNL Apatite Investigation at 100-NR-2 Quality Assurance Project Plan (open access)

PNNL Apatite Investigation at 100-NR-2 Quality Assurance Project Plan

In 2004, the U.S. Department of Energy, Fluor Hanford, Inc., Pacific Northwest National Laboratory (PNNL), and the Washington Department of Ecology agreed that the long-term strategy for groundwater remediation at the 100-N Area would include apatite sequestration as the primary treatment, followed by a secondary treatment if necessary. Since then, the agencies have worked together to agree on which apatite sequestration technology has the greatest chance of reducing strontium-90 flux to the Columbia River. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by staff working on the PNNL Apatite Investigation at 100-NR-2 Project. The plan is designed to be used exclusively by project staff.
Date: April 2, 2009
Creator: Fix, N. J.
Object Type: Report
System: The UNT Digital Library
Country Report on Building Energy Codes in Australia (open access)

Country Report on Building Energy Codes in Australia

This report is part of a series of reports on building energy efficiency codes in countries associated with the Asian Pacific Partnership (APP) - Australia, South Korea, Japan, China, India, and the United States of America (U.S.). This reports gives an overview of the development of building energy codes in Australia, including national energy policies related to building energy codes, history of building energy codes, recent national projects and activities to promote building energy codes. The report also provides a review of current building energy codes (such as building envelope, HVAC, and lighting) for commercial and residential buildings in Australia.
Date: April 2, 2009
Creator: Shui, Bin; Evans, Meredydd & Somasundaram, Sriram
Object Type: Report
System: The UNT Digital Library
Letter Report Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Crater Flat, Nye County, Nevada (open access)

Letter Report Yucca Mountain Environmental Monitoring Systems Initiative - Air Quality Scoping Study for Crater Flat, Nye County, Nevada

The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy's Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) (cover page figure) is collecting data at eight sites outside the NTS, including Ash Meadows National Wildlife Refuge (NWR), Beatty, Sarcobatus Flats, Rachel, Caliente, Pahranagat NWR, Crater Flat, and Tonopah Airport, and at four sites on the NTS (Engelbrecht et al., 2007a-d). The trailer is stationed at any one site for approximately eight weeks at a time. This letter report provides a summary of air quality and meteorological data, on completion of the site's sampling program.
Date: April 2, 2009
Creator: Engelbrecht, J.; Kavouras, I.; Campbell, D.; S.Campbell; Kohl, S. & Shafer, D.
Object Type: Report
System: The UNT Digital Library
Basin-Scale Hydrologic Impacts of CO2 Storage: Regulatory and Capacity Implications (open access)

Basin-Scale Hydrologic Impacts of CO2 Storage: Regulatory and Capacity Implications

Industrial-scale injection of CO{sub 2} into saline sedimentary basins will cause large-scale fluid pressurization and migration of native brines, which may affect valuable groundwater resources overlying the deep sequestration reservoirs. In this paper, we discuss how such basin-scale hydrologic impacts can (1) affect regulation of CO{sub 2} storage projects and (2) may reduce current storage capacity estimates. Our assessment arises from a hypothetical future carbon sequestration scenario in the Illinois Basin, which involves twenty individual CO{sub 2} storage projects in a core injection area suitable for long-term storage. Each project is assumed to inject five million tonnes of CO{sub 2} per year for 50 years. A regional-scale three-dimensional simulation model was developed for the Illinois Basin that captures both the local-scale CO{sub 2}-brine flow processes and the large-scale groundwater flow patterns in response to CO{sub 2} storage. The far-field pressure buildup predicted for this selected sequestration scenario suggests that (1) the area that needs to be characterized in a permitting process may comprise a very large region within the basin if reservoir pressurization is considered, and (2) permits cannot be granted on a single-site basis alone because the near- and far-field hydrologic response may be affected by interference between individual …
Date: April 2, 2009
Creator: Birkholzer, J.T. & Zhou, Q.
Object Type: Report
System: The UNT Digital Library