Resource Type

Development of Key Technologies for White Lighting Based on Light-Emitting Diodes (LEDs) (open access)

Development of Key Technologies for White Lighting Based on Light-Emitting Diodes (LEDs)

This program was organized to focus on materials development issues critical to the acceleration of solid-state lighting, and was split into three major thrust areas: (1) study of dislocation density reduction for GaN grown on sapphire using 'cantilever epitaxy', and the impact of dislocation density on the performance of state-of-the-art high-power LEDs; (2) the evaluation of in situ techniques for monitoring gas phase chemistry and the properties of GaN-based layers during metal-organic vapor phase epitaxy (MOCVD), and (3) feasibility for using semiconductor nanoparticles ('quantum dots') for the down-conversion of blue or ultraviolet light to generate white light. The program included a partnership between Lumileds Lighting (epitaxy and device fabrication for high power LEDs) and Sandia National Laboratories (cantilever epitaxy, gas phase chemistry, and quantum dot synthesis). Key findings included: (1) cantilever epitaxy can provide dislocation density reduction comparable to that of more complicated approaches, but all in one epitaxial growth step; however, further improvements are required to realize significant gains in LED performance at high drive currents, (2) in situ tools can provide detailed knowledge about gas phase chemistry, and can be used to monitor and control epitaxial layer composition and temperature to provide improved yields (e.g., a fivefold increase …
Date: March 31, 2004
Creator: Goetz, Werner; Imler, Bill; Kim, James; Kobayashi, Junko; Kim, Andrew; Krames, Mike et al.
System: The UNT Digital Library
Determination of critical length scales for corrosion processes using microelectroanalytical techniques. (open access)

Determination of critical length scales for corrosion processes using microelectroanalytical techniques.

A key factor in our ability to produce and predict the stability of metal-based macro- to nano-scale structures and devices is a fundamental understanding of the localized nature of corrosion. Corrosion processes where physical dimensions become critical in the degradation process include localized corrosion initiation in passivated metals, microgalvanic interactions in metal alloys, and localized corrosion in structurally complex materials like nanocrystalline metal films under atmospheric and inundated conditions. This project focuses on two areas of corrosion science where a fundamental understanding of processes occurring at critical dimensions is not currently available. Sandia will study the critical length scales necessary for passive film breakdown in the inundated aluminum (Al) system and the chemical processes and transport in ultra-thin water films relevant to the atmospheric corrosion of nanocrystalline tungsten (W) films. Techniques are required that provide spatial information without significantly perturbing or masking the underlying relationships. Al passive film breakdown is governed by the relationship between area of the film sampled and its defect structure. We will combine low current measurements with microelectrodes to study the size scale required to observe a single initiation event and record electrochemical breakdown events. The resulting quantitative measure of stability will be correlated with metal …
Date: March 1, 2004
Creator: Zavadil, Kevin Robert & Wall, Frederick Douglas
System: The UNT Digital Library
Tracing Geothermal Fluids (open access)

Tracing Geothermal Fluids

Geothermal water must be injected back into the reservoir after it has been used for power production. Injection is critical in maximizing the power production and lifetime of the reservoir. To use injectate effectively the direction and velocity of the injected water must be known or inferred. This information can be obtained by using chemical tracers to track the subsurface flow paths of the injected fluid. Tracers are chemical compounds that are added to the water as it is injected back into the reservoir. The hot production water is monitored for the presence of this tracer using the most sensitive analytic methods that are economically feasible. The amount and concentration pattern of the tracer revealed by this monitoring can be used to evaluate how effective the injection strategy is. However, the tracers must have properties that suite the environment that they will be used in. This requires careful consideration and testing of the tracer properties. In previous and parallel investigations we have developed tracers that are suitable from tracing liquid water. In this investigation, we developed tracers that can be used for steam and mixed water/steam environments. This work will improve the efficiency of injection management in geothermal fields, lowering …
Date: March 1, 2004
Creator: Adams, Michael C. & Nash, Greg
System: The UNT Digital Library
Characterizing two-phase flow relative permeabilities in chemicalflooding using a pore-scale network model (open access)

Characterizing two-phase flow relative permeabilities in chemicalflooding using a pore-scale network model

A dynamic pore-scale network model is presented for investigating the effects of interfacial tension and oil-water viscosity on relative permeability during chemical flooding. This model takes into account both viscous and capillary forces in analyzing the impact of chemical properties on flow behavior or displacement configuration, as opposed to the conventional or invasion percolation algorithm which incorporates capillary pressure only. The study results indicate that both water and oil relative-permeability curves are dependent strongly on interfacial tension as well as an oil-water viscosity ratio. In particular, water and oil relative-permeability curves are both found to shift upward as interfacial tension is reduced, and they both tend to become linear versus saturation once interfacial tension is at low values. In addition, the oil-water viscosity ratio appears to have only a small effect under conditions of high interfacial tension. When the interfacial tension is low, however, water relative permeability decreases more rapidly (with the increase in the aqueous-phase viscosity) than oil relative permeability. The breakthrough saturation of the aqueous phase during chemical flooding tends to decrease with the reduction of interfacial tension and may also be affected by the oil-water viscosity ratio.
Date: March 15, 2004
Creator: Liu, Qingjie; Shen, Pingping & Wu, Yu-Shu
System: The UNT Digital Library
The Tiffany Unit N2 - ECBM Pilot: A Reservoir Modeling Study (open access)

The Tiffany Unit N2 - ECBM Pilot: A Reservoir Modeling Study

In October, 2000, the U.S. Department of Energy, through contractor Advanced Resources International, launched a multi-year government-industry R&D collaboration called the Coal-Seq project. The Coal-Seq project is investigating the feasibility of CO{sub 2} sequestration in deep, unmineable coalseams, by performing detailed reservoir studies of two enhanced coalbed methane recovery (ECBM) field projects in the San Juan basin. The two sites are the Allison Unit, operated by Burlington Resources, and into which CO{sub 2} is being injected, and the Tiffany Unit, operating by BP America, into which N{sub 2} is being injected (the interest in understanding the N{sub 2}-ECBM process has important implications for CO{sub 2} sequestration via flue-gas injection). The purposes of the field studies are to understand the reservoir mechanisms of CO{sub 2} and N{sub 2} injection into coalseams, demonstrate the practical effectiveness of the ECBM and sequestration processes, demonstrate an engineering capability to model them, and to evaluate sequestration economics. In support of these efforts, laboratory and theoretical studies are also being performed to understand and model multi-component isotherm behavior, and coal permeability changes due to swelling with CO{sub 2} injection. This report describes the results of an important component of the overall project, the Tiffany Unit reservoir …
Date: March 31, 2004
Creator: Reeves, Scott & Oudinot, Anne
System: The UNT Digital Library
Failure Forewarning in NPP Equipment NERI2000-109 Final Project Report (open access)

Failure Forewarning in NPP Equipment NERI2000-109 Final Project Report

The objective of this project is forewarning of machine failures in critical equipment at next-generation nuclear power plants (NPP). Test data were provided by two collaborating institutions: Duke Engineering and Services (first project year), and the Pennsylvania State University (Applied Research Laboratory) during the second and third project years. New nonlinear methods were developed and applied successfully to extract forewarning trends from process-indicative, time-serial data for timely, condition-based maintenance. Anticipation of failures in critical equipment at next-generation NPP will improve the scheduling of maintenance activities to minimize safety concerns, unscheduled non-productive downtime, and collateral damage due to unexpected failures. This approach provides significant economic benefit, and is expected to improve public acceptance of nuclear power. The approach is a multi-tiered, model-independent, and data-driven analysis that uses ORNL's novel nonlinear method to extract forewarning of machine failures from appropriate data. The first tier of the analysis provides a robust choice for the process-indicative data. The second tier rejects data of inadequate quality. The third tier removes signal artifacts that would otherwise confound the analysis, while retaining the relevant nonlinear dynamics. The fourth tier converts the artifact-filtered time-serial data into a geometric representation, that is then transformed to a discrete distribution function …
Date: March 26, 2004
Creator: Hively, LM
System: The UNT Digital Library
Strategy application, observability, and the choice combinator. (open access)

Strategy application, observability, and the choice combinator.

In many strategic systems, the choice combinator provides a powerful mechanism for controlling the application of rules and strategies to terms. The ability of the choice combinator to exercise control over rewriting is based on the premise that the success and failure of strategy application can be observed. In this paper we present a higher-order strategic framework with the ability to dynamically construct strategies containing the choice combinator. To this framework, a combinator called hide is introduced that prevents the successful application of a strategy from being observed by the choice combinator. We then explore the impact of this new combinator on a real-world problem involving a restricted implementation of the Java Virtual Machine.
Date: March 1, 2004
Creator: Winter, Victor Lono (University of Nebraska at Omaha)
System: The UNT Digital Library
China's sustainable energy future: Scenarios of energy and carbonemissions (Summary) (open access)

China's sustainable energy future: Scenarios of energy and carbonemissions (Summary)

China has ambitious goals for economic development, and mustfind ways to power the achievement of those goals that are bothenvironmentally and socially sustainable. Integration into the globaleconomy presents opportunities for technological improvement and accessto energy resources. China also has options for innovative policies andmeasures that could significantly alter the way energy is acquired andused. These opportunities andoptions, along with long-term social,demographic, and economic trends, will shape China s future energysystem, and consequently its contribution to emissions of greenhousegases, particularly carbon dioxide (CO2). In this study, entitled China sSustainable Energy Future: Scenarios of Energy and Carbon Emissions, theEnergy Research Institute (ERI), an independent analytic organizationunder China's Na tional Development and Reform Commission (NDRC), soughtto explore in detail how China could achieve the goals of the TenthFive-Year Plan and its longer term aims through a sustainable developmentstrategy. China's ability to forge a sustainable energy path has globalconsequences. China's annual emissions of greenhouse gases comprisenearly half of those from developing countries, and 12 percent of globalemissions. Most of China's greenhouse gas emissions are in the form ofCO2, 87 percent of which came from energy use in 2000. In that year,China's carbon emissions from energy use and cement production were 760million metric tons (Mt-C), …
Date: March 10, 2004
Creator: Zhou, Dadi; Levine, Mark; Dai, Yande; Yu, Cong; Guo, Yuan; Sinton, Jonathan E. et al.
System: The UNT Digital Library
INTERNATIONAL COLLABORATION ON CO2 SEQUESTRATION (open access)

INTERNATIONAL COLLABORATION ON CO2 SEQUESTRATION

After the permit to conduct a field experiment in Norway was revoked on August 22, 2002, we started executing our contingency plan to conduct a cruise at the Loihi Seamount in Hawaii in December 2002. After a few intense months of preparation, the cruise took place on December 3-13, 2002. In total, eight dives were made with the Pisces V submarine. The primary goal of the experiment was to assess the effect of CO{sub 2} on marine organisms. Studies were done using scavenger traps, as well as collecting water samples and surveying the natural CO{sub 2} plume at the Loihi Seamount. This report documents the experiment in more detail as summarized by the various participants. The data was still being analyzed at the end of this reporting period, so no results are reported here. Both papers and a video on the experiment are being prepared. Some related modeling work is presented in an Appendix in the form of a paper submitted to the Journal of Marine Environmental Engineering. The main goal of our work during this reporting period (August 23, 2002-August 23, 2003) was to conduct an experimental cruise at the Loihi Seamount in the Hawaiian Islands. The work included …
Date: March 1, 2004
Creator: Herzog, Howard J. & Adams, E. Eric
System: The UNT Digital Library
Final-part metrology for LIGA springs, Build Group 1. (open access)

Final-part metrology for LIGA springs, Build Group 1.

The LIGA spring is a recently designed part for defense program applications. The Sandia California LIGA team has produced an initial group build of these nickel alloy parts. These are distinctive in having a macroscopic lateral size of about 1 cm, while requiring microscopic dimensional precision on the order of a few micrometers. LIGA technology capabilities at Sandia are able to manufacture such precise structures. While certain aspects of the LIGA process and its production capabilities have been dimensionally characterized in the past, [1-6] the present work is exclusive in defining a set of methods and techniques to inspect and measure final LIGA nickel alloy parts in large prototype quantities. One hundred percent inspection, meaning that every single LIGA part produced needs to be measured, ensures quality control and customer satisfaction in this prototype production run. After a general visual inspection of the parts and an x-ray check for voids, high precision dimensional metrology tools are employed. The acquired data is analyzed using both in house and commercially available software. Examples of measurements illustrating these new metrology capabilities are presented throughout the report. These examples furthermore emphasize that thorough inspection of every final part is not only essential to characterize …
Date: March 1, 2004
Creator: Aigeldinger, Georg; Skala, Dawn M.; Ceremuga, Joseph T. & Mills, Bernice E.
System: The UNT Digital Library
Development of laser diagnostics for in situ measurements of entrained particles in recovery boilers. (open access)

Development of laser diagnostics for in situ measurements of entrained particles in recovery boilers.

As part of the U.S. Department of Energy (DOE) Office of Industrial Technologies (OIT) Industries of the Future (IOF) Forest Products research program, two different laser diagnostic techniques have been implemented in pulp mill recovery boilers to provide important information on entrained particles. One technique, based on single-particle scattering of a low-power, continuous-wave (cw) laser source, measures the velocity, concentration, and size distribution of particles within the furnace flow, over a predetermined range of particle sizes. For application to recovery boilers, this technique was designed to measure the range of particle sizes known as intermediate size particles (ISPs), roughly from 2-100 {micro}m in diameter. The other diagnostic technique, known as laser-induced breakdown spectroscopy (LIBS), uses a pulsed, high-power laser beam to create a localized plasma spark in the flow, allowing the measurement of the elemental composition of the entrained particles. This technique is most sensitive for particles less than 10 {micro}m in diameter. Implementing these laser diagnostic techniques in recovery boilers proved to be challenging. For the particle scattering measurement, the use of a narrow aperture for measurement of the forward scattered light was postulated and later confirmed to be effective in minimizing background signals associated with the dense sodium …
Date: March 1, 2004
Creator: Holve, Donald J. (Process Metrix LLC, San Ramon, CA) & Shaddix, Christopher R.
System: The UNT Digital Library
The interfacial bioscience grand challenge. (open access)

The interfacial bioscience grand challenge.

This report is broken down into the following 3 sections: (1) Chemical Cross-linking and Mass Spectrometry Applied to Determination of Protein Structure and Dynamics; (2) Computational Modeling of Membrane Protein Structure and Dynamics; and (3) Studies of Toxin-Membrane Interactions using Single Molecule Biophysical Methods.
Date: March 1, 2004
Creator: Lane, Pamela; Stevens, Mark Jackson; Jacobsen, Richard B.; Hong, Joohee; Ayson, Marites J.; Crozier, Paul Stewart et al.
System: The UNT Digital Library
Soot properties and species measurements in a two-meter diameter JP-8 pool fire : 2003 test series. (open access)

Soot properties and species measurements in a two-meter diameter JP-8 pool fire : 2003 test series.

A tunable diode laser absorption spectroscopy probe was used to measure in situ soot properties and species concentrations in a two-meter diameter JP-8 pool fire. Thirty-five tests were performed at the Lurance Canyon Burn Site operated by Sandia in Albuquerque, New Mexico. The axial profile of the fire was characterized with a series of tests with the probe located on the centerline at heights ranging from 0.5 m to 2.0 m in 0.25 m increments. The radial profile of the fire was characterized with a series of tests with the probe 1.0 m above the fuel surface at radial positions ranging from 0.0 m to 0.6 m, in 0.1 m increments. Experiments were also performed with variation of the air flow into the facility. Soot concentration was determined using a light extinction measurement based on the transmission of a solid-state red laser (635 nm) through the 3.7 cm long probe volume. Soot temperature and a second estimate of soot concentration were measured using two-color optical pyrometry at 850 nm and 1000 nm. The effective data rate for these measurements was 10 kHz. Finally, tunable diode laser absorption spectroscopy was used to estimate the concentrations of water vapor, acetylene, and methane. …
Date: March 1, 2004
Creator: Shaddix, Christopher R. & Murphy, Jeffrey J.
System: The UNT Digital Library
DVD Based Integrated Electronic Pulser (open access)

DVD Based Integrated Electronic Pulser

The DVD based integrated pulser combines the storage capacity and simplicity of DVD technology with commonly available electronic components to build a relatively inexpensive yet highly capable testing instrument. DVD technology has matured to the mass consumer level and has found widespread acceptance in many scientific, industrial, and consumers sectors. Coupling the removable media and relatively large data capacity with a simple electronic readout allows this device to be easy to build, export and authenticate. Since there are few parts and the heart of the device is a mass consumer item the duplication cost is very low.
Date: March 30, 2004
Creator: Hughes, Michael A.; Kouzes, Richard T.; Morris, Scott J.; Pitts, W. K.; Pratt, Rick M. & Robinson, Eric E.
System: The UNT Digital Library
Synthesis of Novel Extended Phases of Molecular Solids at High Pressures and Temperatures (open access)

Synthesis of Novel Extended Phases of Molecular Solids at High Pressures and Temperatures

This study is for in-situ investigation of chemical bonding and molecular structure of low z-elements and simple molecular solids at high pressures and temperatures using 3rd-generation synchrotron x-ray diffraction. To understand the contribution of the empty d-electron orbital of Mg in relation to the formation of molecular solids like MgO, which is one of the important Earth lower mantle materials and MgB{sub 2}, which has recently been the focus of intense superconducting material research, we have performed double-sided laser heating experiments using a diamond anvil cell (DAC). Understanding the structural stability and the formation of the above Mg-compounds requires studying Mg itself as well as the relevant compounds. BL10XU at the Spring-8 was used to study phase stability and make accurate equation of state (EOS) determinations of Mg coupled with external heating and the double-sided laser heating technique. Monochromatic x-ray at 30 keV (0.4135 {angstrom}) was focused to about 40 {micro}m at the sample and the diffracted x-ray were recorded using a high-resolution image plate (3000 x 3000 pixels with a 0.1 mm resolution per pixel). EOS parameters for hcp and bcc Mg were determined by fitting to a Birch-Murnaghan equation. An isothermal compression of Mg at 300 K up …
Date: March 30, 2004
Creator: Yoo, C; Evans, W & Cynn, H
System: The UNT Digital Library
Computation Directorate Annual Report 2003 (open access)

Computation Directorate Annual Report 2003

Big computers are icons: symbols of the culture, and of the larger computing infrastructure that exists at Lawrence Livermore. Through the collective effort of Laboratory personnel, they enable scientific discovery and engineering development on an unprecedented scale. For more than three decades, the Computation Directorate has supplied the big computers that enable the science necessary for Laboratory missions and programs. Livermore supercomputing is uniquely mission driven. The high-fidelity weapon simulation capabilities essential to the Stockpile Stewardship Program compel major advances in weapons codes and science, compute power, and computational infrastructure. Computation's activities align with this vital mission of the Department of Energy. Increasingly, non-weapons Laboratory programs also rely on computer simulation. World-class achievements have been accomplished by LLNL specialists working in multi-disciplinary research and development teams. In these teams, Computation personnel employ a wide array of skills, from desktop support expertise, to complex applications development, to advanced research. Computation's skilled professionals make the Directorate the success that it has become. These individuals know the importance of the work they do and the many ways it contributes to Laboratory missions. They make appropriate and timely decisions that move the entire organization forward. They make Computation a leader in helping LLNL achieve …
Date: March 12, 2004
Creator: Crawford, D L; McGraw, J R; Ashby, S F; McCoy, M G; Michels, T C & Eltgroth, P G
System: The UNT Digital Library
Parris Island Wastewater Treatment Plant SCADA Upgrades Final Report (open access)

Parris Island Wastewater Treatment Plant SCADA Upgrades Final Report

Marine Corp Recruit Depot (MCRD), Parris Island, SC, home of the Easter Recruiting Region Marine Corp Boot Camp, found itself in a situation common to Department of Defense (DOD) facilities. It had to deal with several different types of installed energy-related control systems that could not talk to each other. This situation was being exacerbated by the installation of a new and/or unique type of control system for every new building being constructed or older facility that was being upgraded. The Wastewater Treatment Facility (WWTF) and lift station controls were badly in need of a thorough inspection and a new Supervisory Control and Data Acquisition (SCADA) system upgrade to meet environmental, safety, manpower, and maintenance concerns. A project was recently completed to implement such a wastewater treatment SCADA upgrade, which is compatible with other upgrades to the energy monitoring and control systems for Parris Island buildings and the Pacific Northwest National Laboratory (PNNL) Decision Support for Operations and Maintenance (DSOM) system installed at the Central Energy Plant (CEP). This project included design, specification, procurement, installation, and testing an upgraded SCADA alarm, process monitoring, and display system; and training WWTF operators in its operation. The ultimate goal of this and the …
Date: March 18, 2004
Creator: Meador, Richard J. & Hatley, Darrel D.
System: The UNT Digital Library
Non-Process Element (NPE) Removal Using Functionalized Monolayers on Mesoporous Supports (open access)

Non-Process Element (NPE) Removal Using Functionalized Monolayers on Mesoporous Supports

As Kraft pulp mills move toward minimum impact manufacturing, one of the most difficult challenges is the development of strategies for dealing effectively with buildup, carryover, and recovery of cationic and anionic non-process elements (NPEs). Even at low concentrations, NPEs present a serious concern due to scaling and other reactions caused by Ca, Mg, Mn, Fe, Cu, phosphates, silicates, and aluminates. The drivers behind NPE removal include environmental regulatory issues (e.g., Mn), scale formation, reduced bleaching efficiency, and corrosion. Before closure can be achieved in the bleach cycle, methods must be developed for efficient and cost-effective removal of NPEs from bleach filtrate streams. To be commercially viable, a highly selective, high-capacity, and regenerable media must be developed. In addition, limited prefiltration and high resistance to attrition of exchange material will significantly reduce costs, which is key to widespread commercial application. This project accurately determined the chemical composition of a Weyerhauser bleach plant effluent in the Eop, D0, and D1 stages. Due to environmental regulatory concerns, Mn was the principal target of this study. Mn was found to be present in these samples in the range of 0.16 to 3.97 ppm. The Mn was found to be in the divalent oxidation …
Date: March 26, 2004
Creator: Leugemors, Robert K.; Fryxell, Glen E.; Mattigod, Shas V. & Persinger, W H.
System: The UNT Digital Library
PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT. (open access)

PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.

We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--Potential enhancement of charm production; Open beauty production; Flavor dependence of jet quenching and QCD energy loss; Accurate charm reference for quarkonium; Thermal dilepton radiation; High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}; and Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--{Delta}G/G with charm; {Delta}G/G with beauty; and x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over …
Date: March 30, 2004
Creator: AKIBA,Y.
System: The UNT Digital Library
A Contamination Vulnerability Assessment for the Sacramento Area Groundwater Basin (open access)

A Contamination Vulnerability Assessment for the Sacramento Area Groundwater Basin

In response to concerns expressed by the California Legislature and the citizenry of the State of California, the State Water Resources Control Board (SWRCB), implemented a program to assess groundwater quality, and provide a predictive capability for identifying areas that are vulnerable to contamination. The program was initiated in response to concern over public supply well closures due to contamination by chemicals such as MtBE from gasoline, and solvents from industrial operations. As a result of this increased awareness regarding groundwater quality, the Supplemental Report of the 1999 Budget Act mandated the SWRCB to develop a comprehensive ambient groundwater-monitoring plan, and led to the initiation of the Ambient Groundwater Monitoring and Assessment (GAMA) Program. The primary objective of the GAMA Program is to assess the water quality and to predict the relative susceptibility to contamination of groundwater resources throughout the state of California. Under the GAMA program, scientists from Lawrence Livermore National Laboratory (LLNL) collaborate with the SWRCB, the U.S. Geological Survey, the California Department of Health Services (DHS), and the California Department of Water Resources (DWR) to implement the groundwater assessment program in cooperation with local water purveyors. In 2001 and 2002, LLNL carried out this vulnerability study in …
Date: March 10, 2004
Creator: Moran, J. E.; Hudson, G. B.; Eaton, G. F. & Leif, R.
System: The UNT Digital Library
133Ba as a gamma-ray surrogate source for 1kg HEU and 10g 239Pu and 252Cf as a Neutron Surrogate for Pu (open access)

133Ba as a gamma-ray surrogate source for 1kg HEU and 10g 239Pu and 252Cf as a Neutron Surrogate for Pu

Monte Carlo was performed for the purpose of relating gamma-ray signal strength from 1kg of HEU and 10g of {sup 239}Pu (as described in the ASTM standards) to the radiation emitted from an amount of {sup 133}Ba. A determination was made on the amount of {sup 133}Ba that could act as a surrogate for the specified amounts of HEU and Pu. {sup 133}Ba is not the ideal source to use as a surrogate for HEU because of its higher energies. {sup 133}Ba was chosen as the surrogate since it has a half-life of 10.54 years, rather then the more ideal surrogate of {sup 57}Co which has a half-life of 271 days. A similar Monte Carlo was performed for the purpose of relating neutron signal strength from 200g of Pu (as described in the ASTM standards) to the radiation emitted from an amount of shielded {sup 252}Cf. A determination was made on the amount of {sup 252}Cf necessary to act as a surrogate for the 200g of Pu. An ASTM standard source is a metallic sphere, cube, or right cylinder of SNM having maximum self-attenuation of its emitted radiation. For plutonium, the source should be at least 93% {sup 239}Pu, less …
Date: March 2004
Creator: Pohl, Bertram A. & Archer, Daniel E.
System: The UNT Digital Library
A White Paper Prepared for the OpenMP Architectural Review Board on DMPL: An OpenMP DLL Debugging Interface (open access)

A White Paper Prepared for the OpenMP Architectural Review Board on DMPL: An OpenMP DLL Debugging Interface

OpenMP is a widely adopted standard for threading directives across compiler implementations. The standard is very successful since it provides application writers with a simple, portable programming model for introducing shared memory parallelism into their codes. However, the standards do not address key issues for supporting that programming model in development tools such as debuggers. In this paper, we present DMPL, an OpenMP debugger interface that can be implemented as a dynamically loaded library. DMPL is currently being considered by the OpenMP Tools Committee as a mechanism to bridge the development tool gap in the OpenMP standard.
Date: March 17, 2004
Creator: Cownie, James; DelSignore, John, Jr.; de Supinski, Bronis R. & Warren, Karen
System: The UNT Digital Library
Automated video screening for unattended background monitoring in dynamic environments. (open access)

Automated video screening for unattended background monitoring in dynamic environments.

This report addresses the development of automated video-screening technology to assist security forces in protecting our homeland against terrorist threats. A threat of specific interest to this project is the covert placement and subsequent remote detonation of bombs (e.g., briefcase bombs) inside crowded public facilities. Different from existing video motion detection systems, the video-screening technology described in this report is capable of detecting changes in the static background of an otherwise, dynamic environment - environments where motion and human activities are persistent. Our goal was to quickly detect changes in the background - even under conditions when the background is visible to the camera less than 5% of the time. Instead of subtracting the background to detect movement or changes in a scene, we subtracted the dynamic scene variations to produce an estimate of the static background. Subsequent comparisons of static background estimates are used to detect changes in the background. Detected changes can be used to alert security forces of the presence and location of potential threats. The results of this research are summarized in two MS Power-point presentations included with this report.
Date: March 1, 2004
Creator: Carlson, Jeffrey J.
System: The UNT Digital Library
Transverse coupling impedance of the AGS A5 Injection Kicker Magnet (open access)

Transverse coupling impedance of the AGS A5 Injection Kicker Magnet

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Date: March 1, 2004
Creator: H., Hahn & Zhang, W.
System: The UNT Digital Library