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Reconciliation Report

Description: Reconciliation report with an ending account balance of $2,398.57 reconciled for the period ending on December 31, 2002.
Date: January 22, 2003
Partner: UNT Libraries Special Collections
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The Impact of Humidity, Temperature and Ultraviolet Light on the Near-Field Environmental Fate of Pinacolyl Alcohol, Methyl Iodide, Methylphosphonic Dichloride (DCMP) and Thionyl Chloride Using an Environmental Wind Tunnel

Description: Understanding the near-field fate of parent chemicals and their decay products in the atmosphere provides essential information for the development of remote chemical sensors. To elucidate the near-field fate of candidate chemical signatures, selected gas phase compounds were introduced into atmospheres of varying humidity, temperature and incident light flux. These atmospheres were maintained in an environmental wind tunnel for periods typical of near-field transport scenarios. The range of humidity and temperature into which the compounds were emitted encompassed arid, temperate, and tropical values. Simulated sunlight exposure was used to evaluate the impact of time of release on signature composition. The rates of compound decay and evolution of transformation products under the various environmental conditions were monitored in real time. A Fourier transform infrared spectrometer and a gas chromatograph/mass spectrometer were used to determine chemical concentration, evaluate detectability, and identify potential interferences to the detection capability. Specifically, this report describes the initial system function tests with pinacolyl alcohol and methyl iodide and subsequent atmospheric fate experiments with methylphosphonic dichloride and thionyl chloride. Test system function was evaluated using pinacolyl alcohol because as a relatively non-reactive compound, it served as a negative control for the system. Methyl iodide is a compound known to photodissociate in the atmosphere and therefore was used to evaluate the effectiveness of the test system to detect a known positive effect under specific conditions. Results from the function tests showed that sufficient vapor generation into the large volume of the wind tunnel could be accomplished within a reasonable time period and that the operating conditions of the wind tunnel did not appear to affect the decay rate of the two initial test chemicals. As expected, no near-field decay of pinacolyl alcohol was observed under a wide range of temperature and humidity conditions. Further, both analytical techniques could detect …
Date: January 24, 2003
Creator: Driver, Crystal J.; Johnson, Timothy J.; Su, Yin-Fong; Alexander, M. Lizabeth; Fellows, Robert J.; Magnuson, Jon K. et al.
Partner: UNT Libraries Government Documents Department
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Retrieval and Pipeline Transfer Assessment of Hanford Tank 241-AN-105 Waste

Description: This study assesses five steps for Tank 241-AN-105 waste retrieval and subsequent pipeline transfer: 1. Remove supernatant liquid waste from AN-105 and transfer it through a pipeline with inline dilution with water (1st liquid waste transfer). 2. Add water (as a diluent) to Tank AN-105. 3. Mix the saltcake waste and water with mixer pumps to dissolve soluble solids. 4. Let undissolved solids settle to the tank bottom. 5. Remove the resulting supernatant liquid waste from Tank AN-105 (2nd liquid waste transfer). To assess these five steps for waste retrieval and pipeline transfer, AN-105 waste rheology was measured and solids identified with bright field image, select area diffraction, and energy dispersive x-ray spectroscopy. By combining available in situ and laboratory data, an AN-105 specific viscosity model was developed that can change from several centiPoise of viscosity to tens of millions of centiPoise as a function of strain rate and solid concentration. This viscosity mo del was implemented into the AN-105 computer model to simulate pump jet mixing. The report also evaluates AN-105 slurry waste transfer to AP-102 and AP-104 through a 3-inch (0.07-m) pipeline.
Date: January 15, 2003
Creator: Onishi, Yasuo; Tingey, Joel M.; Recknagle, Kurtis P.; Liu, Jun; Terrones, Guillermo; Yokuda, Satoru T. et al.
Partner: UNT Libraries Government Documents Department
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IGPP 1999-2000 Annual Report

Description: The Institute of Geophysics and Planetary Physics (IGPP) is a Multicampus Research Unit of the University of California (UC). IGPP was founded in 1946 at UC Los Angeles with a charter to further research in the earth and planetary sciences and related fields. The Institute now has branches at UC campuses in Irvine, Los Angeles, San Diego, Santa Cruz and Riverside, and at Los Alamos National Laboratory and Lawrence Livermore National Laboratory. The University-wide IGPP has played an important role in establishing interdisciplinary research in the earth and planetary sciences. For example, IGPP was instrumental in founding the fields of physical oceanography and space physics, which at the time fell between the cracks of established university departments. Because of its multicampus orientation, IGPP has sponsored important inter-institutional consortia in the earth and planetary sciences. Each of the seven branches has a somewhat different intellectual emphasis as a result of the interplay between strengths of campus departments and Laboratory programs. The IGPP branch at Lawrence Livermore National Laboratory (LLNL) was approved by the Regents of the University of California in 1982. IGPP-LLNL emphasizes research in tectonics, geochemistry, and astrophysics. It provides a venue for studying the fundamental aspects of these fields, thereby complementing LLNL programs that pursue applications of these disciplines in national security and energy research. IGPP-LLNL was directed by Charles Alcock during this period and was originally organized into three centers: Geosciences, stressing seismology; High-Pressure Physics, stressing experiments using the two-stage light-gas gun at LLNL; and Astrophysics, stressing theoretical and computational astrophysics. In 1994, the activities of the Center for High-Pressure Physics were merged with those of the Center for Geosciences. The Center for Geosciences, headed by Frederick Ryerson, focuses on research in geophysics and geochemistry. The Astrophysics Research Center, headed by Kem Cook, provides a home for theoretical …
Date: January 27, 2003
Creator: Ryerson, F J; Cook, K & Hitchcock, B
Partner: UNT Libraries Government Documents Department
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Ultrasonic Examination of Double-Shell Tank 241-AN-105 Examination Completed September 2002

Description: COGEMA Engineering Corporation (COGEMA), under contract from CH2M Hill Hanford Group (CH2M Hill), has performed an ultrasonic examination of selected portions of Double-Shell Tank 241-AN-105. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary tank. The requirements for the ultrasonic examination of Tank 241-AN-105 were to detect, characterize, (idetify, size, and locate), and recod measurements made of any wall thinning, pitting, or cracks that might be present in the wall of the primary tank. Any measurements that exceed the requirements set forth in the Engineering Task Plan (ETP), RPP-8867, are reported to CH2M Hill and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with CH2M Hill, all data is to be recorded on disk and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a reports(s) that describes the results of the COGEMA ultrasonic examinations.
Date: January 3, 2003
Creator: Pardini, Allan F. (BATTELLE (PACIFIC NW LAB)) & Posakony, Gerald J. (BATTELLE (PACIFIC NW LAB))
Partner: UNT Libraries Government Documents Department
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Femtosecond Laser Synthesis of Multi-Element Nanocrystals

Description: We studied the conditions under which short-pulsed laser deposited (PLD) stoichiometric multi-element nanocrystals of GaAs,InP,CoPt and Inconel (an alloy of Cr, Fe and Ni) are formed. The properties of the PLD nanoclusters and the irradiated targets were investigated as a function of the laser pulse-length (150 fs-500 ps) and the inert background gas pressure in the synthesis chamber (microTorr to hundreds of Torr). Our results reveal that the formation of stoichiometric GaAs nanocrystals required ablating a GaAs target with a shorter than 25 ps laser in a {ge} 50 miliTorr of inert background pressure. For InP, a mixture of stoichiometric InP and In nanocrystals with an InP/In ratio of {approx} 1 resulted upon ablating an InP target in Ar at 1 Torr. This InP/In ratio increased to {approx} 5 when ablating the InP target in an Ar pressure of 750 Torr. In case of CoPt alloy, the stoichiometry in the target was not reflected in the collected nanocluster films, independent of the background gas pressure. Interestingly, the stoichiometry of the target was found in the collected nanocluster films when an Inconel target was ablated by a femtosecond laser even in vacuum. It is noted that the constituents of Inconel (Cr, Fe and Ni) have similar vapor pressures while Co and Pt do not. Our experimental results suggest that the stoichiometries of the PLD multi-element nanoclusters are closer with those of the targets when shorter than 25 ps lasers are used. However, this does not imply that simply irradiating a multi-element target in vacuum with a shorter than 25 ps pulse-length laser would automatically result in the formation of stoichiometric nanocrystals. The preservation of the stoichiometry of the irradiated target and the formation of stoichiometric semiconductor nanocrystals require ablating the targets with a shorter than 25 ps laser in a background …
Date: January 8, 2003
Creator: Dinh, L N; Trelenberg, T; Torralva, B; Stuart, B C & Balooch, M
Partner: UNT Libraries Government Documents Department
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Tests of the Contamination Analysis Unit, Phase 2

Description: Results are reported for a project testing the capabilities of a mass spectrometer-based system for analyzing in-situ organic compounds on a variety of substrates. The system, which was built and operated at Lawrence Livermore National Laboratory (LLNL), is termed a Contamination Analysis Unit (CAU) and employs vacuum and thermal desorption of surface residues, followed by ionization and analysis with a Leybold Inficon Transpector mass spectrometer. The CAU was employed in this study to examine soils, cleaner residues, and substrates on Space Shuttle Reusable Solid Rocket Motor (RSRM) components. Project work was supported by ATK Thiokol Propulsion. Major project objectives include: (1) Determine residual propellant and liner components with the CAU after test coupons have been cleaned. (2) Determine if the CAU can detect solvent that has soaked into NBR insulation material, and if possible, determine the time following solvent application during which the cleaning agent is detectable. (3) Test CAU capabilities for analyzing non-flat surfaces on the inside and outside surfaces of the RSRM (12-foot diameter), and nozzle throat housing surfaces (5-foot diameter). (4) Determine if solvent extraction and gas chromatography (GC) approaches are able to enhance the surface analysis data available through use of the mass-spectrometer-based CAU. (5) Determine the CAU's detection limit for various soils and cleaners. (6) Determine if contact of both Viton and silicon O-rings with critical substrates will result in any visual evidence of the contact, when observed under black light. (7) Demonstrate CAU viability during routine Thiokol manufacturing operations.
Date: January 21, 2003
Creator: Meltzer, M
Partner: UNT Libraries Government Documents Department
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New Technology Demonstration of the Whole-Building Diagnostician at the Federal Aviation Administration-Denver Airport

Description: This report describes results from an evaluation of the Whole Building Diagnostician's (WBD) ability to automatically and continually diagnose operational problems in building air handlers at the Federal Aviation Administration's Denver airport.
Date: January 17, 2003
Creator: Pratt, Robert G.; Bauman, Nathan N. & Katipamula, Srinivas
Partner: UNT Libraries Government Documents Department
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Hyperspectral Image-Based Broad Area Search (HIBAS) Final Report Summary

Description: Two of the more important tasks faced by image analysts are broad area search and site monitoring. In each case, the objective is to detect occurrences of targets of interest (e.g., buildings, mobile targets of military significance, etc.). In broad area search, large swaths of countryside are imaged. In site monitoring, a number of smaller areas of interest are imaged multiple times. The crisis currently facing image analysts lies in their inability to analyze massive volumes of remotely sensed imagery in a time critical fashion. The problem has become more critical with technological advances that have enabled images of increasing size, resolution and dimensionality (such as monochrome images at higher spatial resolution--e.g., Digital Globe imagery--and hyperspectral images at higher spectral resolution) to be rapidly acquired.
Date: January 7, 2003
Creator: Paglieroni, D W
Partner: UNT Libraries Government Documents Department
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Comparison of Synchrotron X-Ray Fluorescence Mapping and Micro-XANES to Bulk X-Ray Absorption Spectra in Metal-Contaminated Sediments

Description: Synchrotron X-ray absorption spectroscopy (XAS) is one of the few techniques that can supply molecular-scale information for a variety of elements at concentrations relevant to natural systems in non-vacuum conditions. Bulk XAS analysis supplies the dominant chemical bonding mode(s) for a specific element. In complex materials such as natural soils and sediments, however, the dominant mode may not necessarily be the most reactive because changes in speciation at surfaces may results in changes in reactivity. Our previous work at Naval Air Station (NAS) Alameda (CA) focused on in situ metal chemistry in surface and deep sediments, and the impact of metal mobility by sediment oxidation. Estuary sediments at the Alameda Naval Station Air in California have elevated metal concentrations that increase with increasing depth. The metal concentrations in these sediments are: Cd (10-350 ppm), Cr (200-1000 ppm), Cu (100-230 ppm), Pb (200-1200 ppm) and Zn (250-600 ppm). We have extensively characterized these sediments using bulk XAS and other non-synchrotron supporting methods [ 1]. In this experiment, we collected fluorescence element maps using synchrotron X-ray microprobe of unreacted and seawater-oxidized sediment samples from Alameda NAS to determine the spatial distribution and correlation of lead, zinc, and iron. We then compared micro-XANES spectra for lead and zinc collected with the X-ray microprobe to previously collected bulk XANES spectra. The results from our bulk XAS characterization of the sediments showed both oxide and sulfide components for the trace metals. However, the bulk XAS data were not able to identify the composition of the oxide component (i.e. carbonate or hydroxide), nor could absorbed species or solid solutions be definitively identified. Our objective in using micro-XANES and fluorescence element maps was to attempt a more precise identification of metal speciation in or on individual particles.
Date: January 16, 2003
Creator: O'Day, P; Carroll, S A & Bajt, S
Partner: UNT Libraries Government Documents Department
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Fiber Optic Solutions for Short Pulse Lasers

Description: For applications requiring high beam quality radiation from efficient, compact and rugged sources, diffraction limited fiber lasers are ideal, and to date have been demonstrated at average CW power levels exceeding 100 W with near diffraction limited: output. For conventional single-core step-index single-mode fibers, this power level represents the sealing limit because of nonlinear and laser damage considerations. Higher average powers would exceed nonlinear process thresholds such as the Raman and stimulated Brillouin scattering limit, or else damage the fiber due to the high intensity level in the fiber's core. The obvious way to increase the average power capability of fibers is to increase the area of their core. Simply expanding the core dimensions of the fiber allows a straightforward power sealing due to enhanced nonlinear and power handling characteristics that scale directly with the core area. Femtosecond, chirped-pulse, fiber lasers with pulse energies greater than 1mJ have been demonstrated in the literature [2] using this technique. This output energy was still limited by the onset of stimulated Raman scattering. We have pursued an alternative and complimentary approach which is to reduce the intensity of light propagating in the core by distributing it more evenly across the core area via careful design of the refractive index profile [3]. We have also sought to address the primary issue that results from scaling the core. The enhanced power handling capability comes at the expense of beam quality, as increasing the core diameter in standard step index fibers permits multiple transverse modes to lase simultaneously. Although this problem of multimode operation can be mitigated to some extent by appropriately designing the fiber's waveguide structure, limitations such as bend radius loss, sensitivity to thermally induced perturbations of the waveguide structure, and refractive index control, all become more stringent as the core diameter grows, limiting …
Date: January 29, 2003
Creator: Beach, R; Dawson, J; Liao, Z; Jovanovic, I; Wattellier, B; Payne, S et al.
Partner: UNT Libraries Government Documents Department
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First Quarter Hanford Seismic Report for Fiscal year 2003

Description: This reports earthqaukes that occurred during the first quarter of FY03.
Date: January 15, 2003
Creator: Hartshorn, Donald C.; Reidel, Steve P. & Rohay, Alan C.
Partner: UNT Libraries Government Documents Department
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Using Mode of Action to Assess Health Risks from Mixtures of Chemical/Physical Agents

Description: Interactions between tumor promoters with differing mechanisms of action were examined in male B6C3F1 mice treated with mixtures of dichloroacetate (DCA), trichloroacetate (TCA), and tetrachloride (CT), each of which acts by a different mode of action. Mice were initiated by vinyl carbamate (VC), and then promoted by DCA, TCA, CT, or the pair-wised combinations of the three compounds. The effect of each treatment or treatment combination on tumor number/animal and tumor size was individually assessed at 18, 24, 30 or 36 weeks of treatment. Dose-related increases in tumor size were observed with 20 & 50 mg/kg CT, but each produced equal number of tumors at 36 weeks with the main distinction being a decrease in tumor latency at the higher dose. Overall TCA treatment produced dose-related increases in tumor number at 36 weeks of treatment. Thus, the lower doses of CT and TCA treatments apparently affected tumor size rather than number. Results with DCA were not as clear as a true maximum tumor number was not clearly observed within the experimental period. Treatment of mice receiving a high dose of TCA (2 g/L of drinking water) combined with varying doses of DCA (0.1, 0.5 and 2 g/L) produced increased numbers of tumors at 24 weeks and 36 weeks. However, at 36 weeks of treatment DCA produced a dose-related decrease in the size of tumors promoted by TCA. The low dose of TCA (0.1 g/L) decreased the number of tumors produced by a high dose of DCA, however, higher doses of TCA produced the same number as observed with DCA alone. Since these two chemicals produce lesions with differing phenotypes, the combination would have been expected to be additive with respect to number, but this was obviously not the case. These data suggest that the induction of liver cancer from mixtures …
Date: January 20, 2003
Creator: Bull, Richard J.; Lei, Xingye C. & Sasser, Lyle B.
Partner: UNT Libraries Government Documents Department
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Characterization of Tru Inventories in G and H Cells, 327 Building using a Neutron Instrument Pod

Description: An instrument pod has been designed and constructed to estimate the quantity of TRU isotopes present in hot cells in Hanfords 327 Building. This estimate is required to assign the proper waste classification for ultimate disposal of the hot cell. The instrument pod consists of a cylindrical polyethylene moderator containing three neutron detectors. The pod diameter was chosen to allow the pod to be deployed through a 7-inch port in the hot cell wall. A polyethylene traverse pipe, long enough to extend through the interior of the cell, was designed for insertion through the hot cell port, allowing the pod to be positioned inside the cell. The neutron detectors chosen for the pod were fission chambers, which provides acceptable sensitivity to neutrons with excellent rejection of gammas even in high-contamination cells. The neutron pod was tested and calibrated in PNNLs Low Scatter Room (LSR), using a 252Cf source in both unmoderated and D2O-moderated configurations. The calibration configurations were then modeled using MCNP to arrive at a calibration constant that relates the neutron flux incident on the pod to neutron count rate. The neutron pod was used in the G and H hot cells in the 327 Building. These hot cells had been decommissioned and are slated for disposal. For each hot cell, the neutron pod was positioned at about 10 locations inside the cell and count rates were recorded. The recorded count rates were all very close to background levels, since substantial cleanup effort had been expended in each cell. MCNP modeling was then performed, with plutonium distributed inside the cell in several likely distributions. The models produced values of neutron count rate per gram Pu in the cell. These values were then applied to the measured count rates to determine the quantity of Pu that is in the cell. …
Date: January 2003
Creator: Scherpelz, Robert I.; Mapili, Gabriel M. & Dutt, Dale S.
Partner: UNT Libraries Government Documents Department
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A Case Study of Selected Photographic Inspection Techniques for a Transparency Regime

Description: Photographic inspection techniques have become technically more sophisticated in recent years with the development of advanced equipment for the mass consumer market. High quality digital cameras, for example, are now available around the world. Combined with an appropriate image analysis program on a personal computer, there is now the ability to produce and analyze high quality photographs with a modest level of resources. This report is the summary of a variety of efforts, all aimed at investigating the application of commonly available, mass-market photographic and computer equipment to photographic inspection and analysis of equipment and items. It contains results of equipment test and evaluation as well as a few selected example applications.
Date: January 22, 2003
Creator: Pitts, W K.; Dahl, Nicole M.; Fuller, Erin S.; Geelhood, Bruce D.; Hansen, Randy R.; Knopf, Michael A. et al.
Partner: UNT Libraries Government Documents Department
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Radiation Transmission Measurements for Demron Fabric

Description: Radiation Shield Technologies has requested a measurement survey of its Demron fabric to determine the shielding properties in the x-ray, gamma ray and beta particle emissions in the range of energies relevant to clinical and Homeland Security applications. It is important to perform a detailed measurement program in order to sort out the shielding properties of this material in light of the often-times complex spectra emitted by standard radio-nuclides and x-ray generators. Low energy portions of the spectra are shielded more easily by this fabric than are the higher energy components and a simple single-layer test can lead to misleading results. This concept of ''spectral hardening'' was investigated by measuring the transmission factors for many layers and extracting information from the slopes of the transmission curves thereby obtaining a true picture of the shielding properties of the material as a function of energy. After the initial measurement program was completed, the mass attenuation coefficients were calculated using the LLNL cross section data, TART code, RST supplied weight fractions and the measured density of the fabric. This code is used for the Monte Carlo simulation of coupled neutron-photon transport in 3-D geometry for shielding and other applications. With such a design tool, it is possible to ''tune'' the characteristics of the Demron fabric to meet the specific needs for a given radiation environment.
Date: January 7, 2003
Creator: Friedman, H & Singh, M S
Partner: UNT Libraries Government Documents Department
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Stuffing Carbon Away: Mechanisms of Carbon Sequestration in Soils

Description: Soils offer the potential to sequester large quantities of carbon from the atmosphere for decades to millennia and so may ameliorate the anthropogenic influence of fossil fuel release. However changes in climate can drastically affect the soil's ability to store carbon through changes mineralogy on time scales of human interest. It is essential to understand the major controls on soil carbon dynamics before we attempt to manage sequestration to control atmospheric CO{sub 2} buildup. Models of the terrestrial carbon cycle often use clay content to parameterize soil carbon turnover. Evidence from volcanic soils suggests that soil mineralogy is a major control on a soil's ability to store carbon, because different types of minerals have widely varying abilities to physically and chemically isolate soil organic matter from decomposition, however volcanic soils represent only a small percentage of the earth's soils. The relationship between precipitation and soil carbon storage is also complex and poorly constrained. Significantly, precipitation changes predicted as a result of atmospheric CO{sub 2} doubling include increased rainfall throughout California. We utilized {sup 14}C, {delta}{sup 13}C, and the total organic carbon, iron, and aluminum contents to address the question of the importance of mineralogy and climate on carbon storage in soils formed on a globally representative parent material. The California coastal terraces, formed over the last 500 thousand years as a result of tectonic uplift and sea level change, provide a natural laboratory to examine the effect of mineralogy and climate on carbon storage. We have focused on two terraces sequences, one near Eureka and one near Santa Cruz. Within each set of terraces only soil mineral development varies; all other variables are constant (rainfall, plant systems, and soil parent material, and land management). Annual precipitation at Eureka is twice that at Santa Cruz, allowing us to examine its role …
Date: January 24, 2003
Creator: Reimer, P J; Masiello, C A; Southon, J R; Trumbore, S E; Harden, J W; White, A F et al.
Partner: UNT Libraries Government Documents Department
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Radar Imaging of Spheres in 3D using MUSIC

Description: We have shown that multiple spheres can be imaged by linear and planar EM arrays using only one component of polarization. The imaging approach involves calculating the SVD of the scattering response matrix, selecting a subset of singular values that represents noise, and evaluating the MUSIC functional. The noise threshold applied to the spectrum of singular values for optimal performance is typically around 1%. The resulting signal subspace includes more than one singular value per sphere. The presence of reflections from the ground improves height localization, even for a linear array parallel to the ground. However, the interference between direct and reflected energy modulates the field, creating periodic nulls that can obscure targets in typical images. These nulls are largely eliminated by normalizing the MUSIC functional with the broadside beam pattern of the array. The resulting images show excellent localization for 1 and 2 spheres. The performance for the 3 sphere configurations are complicated by shadowing effects and the greater range of the 3rd sphere in case 2. Two of the three spheres are easily located by MUSIC but the third is difficult to distinguish from other local maxima of the complex imaging functional. Improvement is seen when the linear array is replace with a planar array, which increases the effective aperture height. Further analysis of the singular values and their relationship to modes of scattering from the spheres, as well as better ways to exploit polarization, should improve performance. Work along these lines is currently being pursued by the authors.
Date: January 21, 2003
Creator: Chambers, D H & Berryman, J G
Partner: UNT Libraries Government Documents Department
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Level II Milestone Review of LLNL Program on Grain-Scale Dynamics in Explosives

Description: This document describes an evaluation of the Level II Milestone achievements of the LLNL program on Grain-Scale Dynamics in Explosives on January 14, 2003. ''The Grain-Scale Dynamics in Explosives Program'' is a mixture of advanced computational methodology and physico-chemical theory applied to understanding deflagration and detonation of plastic-bonded explosives from the nano to the macro scales. At many points, the modeling is tied directly to experiments within the precisions of both. Advances are needed in the experimental, theoretical, and computational aspects of detonations. Work reported in this review represents significant, cross-pollinating advances in each area. The team successfully carried out ALE-3D simulations of deflagration in PBX with grain scale effects. (Milestone requirements 1 and 2), interpreted experimental data on flame speed vs. pressure and sensitivity to global kinetics in terms of ALE-3D simulations (Milestone requirement 3), and used the results of these simulations to develop a continuum reactive flow model that captures some of these effects (Milestone requirement 4). By comparing experiments and detonation velocities in small diameter, unconfined explosives, they found non-idealities that remain at intermediate diameters (ca. 1.5 mm) that require further analysis. In all of these areas, the project team has met, indeed exceeded, their Level II Milestone goals.
Date: January 14, 2003
Creator: Nicol, M F; Benson, D J & Yip, S
Partner: UNT Libraries Government Documents Department
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Laser-Material Interaction of Powerful Ultrashort Laser Pulses

Description: Laser-material interaction of powerful (up to a terawatt) ultrashort (several picoseconds or shorter) laser pulses and laser-induced effects were investigated theoretically in this dissertation. Since the ultrashort laser pulse (USLP) duration time is much smaller than the characteristic time of the hydrodynamic expansion and thermal diffusion, the interaction occurs at a solid-like material density with most of the light energy absorbed in a thin surface layer. Powerful USLP creates hot, high-pressure plasma, which is quickly ejected without significant energy diffusion into the bulk of the material, Thus collateral damage is reduced. These and other features make USLPs attractive for a variety of applications. The purpose of this dissertation was development of the physical models and numerical tools for improvement of our understanding of the process and as an aid in optimization of the USLP applications. The study is concentrated on two types of materials - simple metals (materials like aluminum or copper) and wide-bandgap dielectrics (fused silica, water). First, key physical phenomena of the ultrashort light interaction with metals and the models needed to describe it are presented. Then, employing one-dimensional plasma hydrodynamics code enhanced with models for laser energy deposition and material properties at low and moderate temperatures, light absorption was self-consistently simulated as a function of laser wavelength, pulse energy and length, angle of incidence and polarization. Next, material response on time scales much longer than the pulse duration was studied using the hydrocode and analytical models. These studies include examination of evolution of the pressure pulses, effects of the shock waves, material ablation and removal and three-dimensional dynamics of the ablation plume. Investigation of the interaction with wide-bandgap dielectrics was stimulated by the experimental studies of the USLP surface ablation of water (water is a model of biological tissue) and laser-induced pressure waves. Simulations on the basis …
Date: January 6, 2003
Creator: Komashko, A
Partner: UNT Libraries Government Documents Department
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Mechanistic Constitutive Models for Rubber Elasticity and Viscoelasticity

Description: Physically based models which describe the finite strain behavior of vulcanized rubber are developed. Constitutive laws for elasticity and viscoelasticity are derived by integrating over orientation space the forces due to each individual polymer chain. A novel scheme is presented which effectively approximates these integrals in terms of strain and strain invariants. In addition, the details involving the implementation of such models into a quasi-static large strain finite element formulation are provided. In order to account for the finite extensibility of a molecular chain, Langevin statistics is used to model the chain response. The classical statistical model of rubber assumes that polymer chains interact only at the chemical crosslinks. It is shown that such model when fitted for uniaxial tension data cannot fit compression or equibiaxial data. A model which incorporates the entanglement interactions of surrounding chains, in addition to the finite extensibility of the chains, is shown to give better predictions than the classical model. The technique used for approximating the orientation space integral was applied to both the classical and entanglement models. A viscoelasticity model based on the force equilibration process as described by Doi and Edwards is developed. An assumed form for the transient force in the chain is postulated. The resulting stress tensor is composed of an elastic and a viscoelastic portion with the elastic stress given by the proposed entanglement model. In order to improve the simulation of experimental data, it was found necessary to include the effect of unattached or dangling polymer chains in the viscoelasticity model. The viscoelastic effect of such chains is the manifestation of a disengagement process. This disengagement model for unattached polymer chains motivated an empirical model which was very successful in simulating the experimental results considered.
Date: January 21, 2003
Creator: Puso, M
Partner: UNT Libraries Government Documents Department
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FY02 Engineering Technology Reports Volume 1: Technology Base

Description: Engineering has touched on every challenge, every accomplishment, and every endeavor of Lawrence Livermore National Laboratory during its fifty-year history. In this time of transition to new leadership, Engineering continues to be central to the mission of the Laboratory, returning to the tradition and core values of E. O. Lawrence: science-based engineering--turning scientific concepts into reality. This volume of Engineering Technical Reports summarizes progress on the projects funded for technology-base efforts. Technology-base projects effect the natural transition to reduction-to-practice of scientific or engineering methods that are well understood and established. They represent discipline-oriented, core competency activities that are multi-programmatic in application, nature, and scope. Objectives of technology-base funding include: (1) the development and enhancement of tools and processes to provide Engineering support capability, such as code maintenance and improved fabrication methods; (2) the support of Engineering science and technology infrastructure, such as the installation or integration of a new capability; (3) support for technical and administrative leadership through our technology Centers; and (4) the initial scoping and exploration of selected technology areas with high strategic potential, such as assessment of university, laboratory, and industrial partnerships. Five Centers focus and guide longer-term investments within Engineering. The Centers attract and retain top staff, develop and maintain critical core technologies, and enable programs. Through their technology-base projects, they oversee the application of known engineering approaches and techniques to scientific and technical problems.
Date: January 28, 2003
Creator: Minichino, C & Meeker, D
Partner: UNT Libraries Government Documents Department
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Implementation of the AES as a Hash Function for Confirming the Identity of Software on a Computer System

Description: This paper provides a brief overview of the implementation of the Advanced Encryption Standard (AES) as a hash function for confirming the identity of software resident on a computer system. The PNNL Software Authentication team chose to use a hash function to confirm software identity on a system for situations where: (1) there is limited time to perform the confirmation and (2) access to the system is restricted to keyboard or thumbwheel input and output can only be displayed on a monitor. PNNL reviewed three popular algorithms: the Secure Hash Algorithm - 1 (SHA-1), the Message Digest - 5 (MD-5), and the Advanced Encryption Standard (AES) and selected the AES to incorporate in software confirmation tool we developed. This paper gives a brief overview of the SHA-1, MD-5, and the AES and sites references for further detail. It then explains the overall processing steps of the AES to reduce a large amount of generic data-the plain text, such is present in memory and other data storage media in a computer system, to a small amount of data-the hash digest, which is a mathematically unique representation or signature of the former that could be displayed on a computer's monitor. This paper starts with a simple definition and example to illustrate the use of a hash function. It concludes with a description of how the software confirmation tool uses the hash function to confirm the identity of software on a computer system.
Date: January 20, 2003
Creator: Hansen, Randy R.; Bass, Robert B.; Kouzes, Richard T. & Mileson, Nicholas D.
Partner: UNT Libraries Government Documents Department
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