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FY 2004 Annual Report: DOE Project on Heavy Vehicle Aerodynamic Drag (open access)

FY 2004 Annual Report: DOE Project on Heavy Vehicle Aerodynamic Drag

The objective of this report is: (1) Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles; and (2) Establish a database of experimental, computational, and conceptual design information, and demonstrate potential of new drag-reduction devices. The approaches used were: (1) Develop and demonstrate the ability to simulate and analyze aerodynamic flow around heavy truck vehicles using existing and advanced computational fluid dynamics (CFD) tools; (2) Through an extensive experimental effort, generate an experimental data base for code validation; (3) Using experimental data base, validate computations; (4) Provide industry with design guidance and insight into flow phenomena from experiments and computations; and (5) Investigate aero devices (e.g., base flaps, tractor-trailer gap stabilizer, underbody skirts and wedges, blowing and acoustic devices), provide industry with conceptual designs of drag reducing devices, and demonstrate the full-scale fuel economy potential of these devices.
Date: November 18, 2004
Creator: McCallen, R. C.; Salari, K.; Ortega, J.; Castellucci, P.; Eastwood, C.; Whittaker, K. et al.
System: The UNT Digital Library
Determination of collision rates relevant to Weibel-like instability growth rates in classical and non-classical plasmas encountered in fast-ignition experiments (open access)

Determination of collision rates relevant to Weibel-like instability growth rates in classical and non-classical plasmas encountered in fast-ignition experiments

Analytical simulations of fast-electron currents induced by high-density laser-plasma interactions require estimation of various plasma and beam parameters, including temperatures, densities, and collision rates. This note describes a technique used to estimate or calculate these parameters for the case of contemporary multi-terawatt experiments using foil targets as well as for anticipated fast-ignition-scale experiments.
Date: October 18, 2004
Creator: Hill, J M & Key, M H
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
Hanford Site Environmental Surveillance Master Sampling Schedule for Calendar Year 2004 (open access)

Hanford Site Environmental Surveillance Master Sampling Schedule for Calendar Year 2004

Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE). Sampling is conducted to evaluate levels of radioactive and nonradioactive pollutants in the Hanford environs. This document contains the calendar year 2004 schedules for the routine and non-routine collection of samples for the Surface Environmental Surveillance Project (SESP) and Drinking Water Monitoring Project.
Date: February 18, 2004
Creator: Bisping, Lynn E.
System: The UNT Digital Library
Methodological Framework for Analysis of Buildings-Related Programs: The GPRA Metrics Effort (open access)

Methodological Framework for Analysis of Buildings-Related Programs: The GPRA Metrics Effort

The requirements of the Government Performance and Results Act (GPRA) of 1993 mandate the reporting of outcomes expected to result from programs of the Federal government. The U.S. Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE) develops official metrics for its 11 major programs using its Office of Planning, Budget Formulation, and Analysis (OPBFA). OPBFA conducts an annual integrated modeling analysis to produce estimates of the energy, environmental, and financial benefits expected from EERE’s budget request. Two of EERE’s major programs include the Building Technologies Program (BT) and Office of Weatherization and Intergovernmental Program (WIP). Pacific Northwest National Laboratory (PNNL) supports the OPBFA effort by developing the program characterizations and other market information affecting these programs that is necessary to provide input to the EERE integrated modeling analysis. Throughout the report we refer to these programs as “buildings-related” programs, because the approach is not limited in application to BT or WIP. To adequately support OPBFA in the development of official GPRA metrics, PNNL communicates with the various activities and projects in BT and WIP to determine how best to characterize their activities planned for the upcoming budget request. PNNL then analyzes these projects to determine what …
Date: June 18, 2004
Creator: Elliott, Douglas B.; Anderson, Dave M.; Belzer, David B.; Cort, Katherine A.; Dirks, James A. & Hostick, Donna J.
System: The UNT Digital Library
ETAII 6 MEV PEPPERPOT EMITTANCE MEASUREMENT (open access)

ETAII 6 MEV PEPPERPOT EMITTANCE MEASUREMENT

We measured the beam emittance at the ETAII accelerator using a pepper-pot diagnostic at nominal parameters of 6 MeV and 2000 Amperes. During the coarse of these experiments, a ''new tune'' was introduced which significantly improved the beam quality. The source of a background pedestal was investigated and eliminated. The measured ''new tune'' emittance is {var_epsilon}= 8.05 {plus_minus} 0. 53 cm - mr or a normalized emittance of {var_epsilon}{sub n} = 943 {plus_minus} 63 mm - mr In 1990 the ETAII programmatic emphasis was on free electron lasers and the paramount parameter was whole beam brightness. The published brightness for ETAII after its first major rebuild was J = 1 - 3 x 10{sup 8} A/(m - rad){sup 2} at a current and energy of 1000-1400 Amperes and 2.5 MeV. The average normalized emittance derived from table 2 of that report is 864 mm-mr corresponding to a real emittance of 14.8 cm-mr.
Date: October 18, 2004
Creator: Paul, A C; Richardson, R & Weir, J
System: The UNT Digital Library
Disposition Options for Hanford Site K-Basin Spent Nuclear Fuel Sludge (open access)

Disposition Options for Hanford Site K-Basin Spent Nuclear Fuel Sludge

This report provides summary-level information about a group of options that have been identified for the disposition of spent-nuclear-fuel sludge in the K-Basins at the Hanford Site. These options are representative of the range of likely candidates that may be considered for disposition of the sludge. The product of each treatment option would be treated sludge that would meet waste acceptance requirements for disposal as transuranic (TRU) waste at the Waste Isolation Pilot Plant (WIPP).
Date: January 18, 2004
Creator: Mellinger, George B.; Delegard, Calvin H.; Gerber, Mark A.; Naft, Barry N.; Schmidt, Andrew J. & Walton, Terry L.
System: The UNT Digital Library
Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2003 (open access)

Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2003

Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a)(1)-(4) and Article 511.1 of the PNNL Radiological Control Program Description, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually, and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2003 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.
Date: August 18, 2004
Creator: Bivins, Steven R. & Stoetzel, Gregory A.
System: The UNT Digital Library
Accelerated Carbonate Dissolution as a CO2 Separation and Sequestration Strategy (open access)

Accelerated Carbonate Dissolution as a CO2 Separation and Sequestration Strategy

We have proposed a technique that could reduce CO{sub 2} emissions from near coastal fossil-fuel power plants using existing power plant cooling water flow rates (Rau and Caldeira, 1999; Caldeira and Rau, 2000). Preliminary cost estimates are as low as $68 per tonne C sequestered, as compared to > $170 per tonne C estimated for other approaches to CO{sub 2} separation with geologic or deep-ocean storage. Engineers at McDermott Technologies, Inc., have independently estimated the cost of our proposed technique, and came to the conclusion that our cost estimates were at the high end of the likely range. Interest has been expressed in pursuing this approach further both in Norway and in Japan. We have proved the viability of our concept using (1) bench-top laboratory experiments (Figures 1 and 2), (2) computer modeling of those experiments, (3) more sophisticated cost estimates, and (4) three-dimensional computer modeling of the consequences to global ocean chemistry (Figure 3 and 4). The climate and environmental impacts of our current, carbon intensive energy usage demands that effective and practical energy alternatives and CO{sub 2} mitigation strategies be found. As part of this effort, various means of capturing and storing CO{sub 2} generated from fossil-fuel-based energy …
Date: February 18, 2004
Creator: Caldeira, K G; Knauss, K G & Rau, G H
System: The UNT Digital Library
Screening of Maritime Containers to Intercept Weapons of Mass Destruction (open access)

Screening of Maritime Containers to Intercept Weapons of Mass Destruction

The goal of our research was to address the problem of detection of weapons of mass destruction (WMD) materials within containers in common use on commercial cargo trafficking. LLNL has created an experimental test bed for researching potential solutions using (among other techniques) active interrogation with neutrons. Experiments and computational modeling were used to determine the effectiveness of the technique. Chemical weapons materials and high explosives can be detected using neutron activation and simple geometries with little or no intervening material. However in a loaded container there will be nuisance alarms from conflicting signatures resulting from the presence of material between the target and the detector (and the interrogation source). Identifying some elements may require long counting times because of the increased background. We performed some simple signature measurements and simulations of gamma-ray spectra from several chemical simulants. We identified areas where the nuclear data was inadequate to perform detailed computations. We concentrated on the detection of SNM in cargo containers, which will be emphasized here. The goal of the work reported here is to develop a concept for an active neutron interrogation system that can detect small targets of SNM contraband in cargo containers, roughly 5 kg HEU or …
Date: February 18, 2004
Creator: Manatt, D. R.; Sleaford, B.; Schaffer, T.; Accatino, M. R.; Slaughter, D.; Mauger, J. et al.
System: The UNT Digital Library
Microstructure and Creep Properties of TiAl-Ti3Al In-Situ Composites (open access)

Microstructure and Creep Properties of TiAl-Ti3Al In-Situ Composites

Objectives: {lg_bullet} Exploit thermomechanical-processing techniques to fabricate TiAl/Ti3Al in-situ laminate composites with the size of lamella width down to submicron or nanometer length-scales. {lg_bullet} Characterize microstructure and elevated-temperature creep resistance of the in-situ composites. {lg_bullet} Investigate the fundamental interrelationships among microstructures, alloying additions, and mechanical properties of the in-situ composites so as to achieve the desired properties of the in-situ composites for high-temperature structural applications.
Date: February 18, 2004
Creator: Hodge, A M & Hsiung, L L
System: The UNT Digital Library
Interim Report on Uranium Metal Segregation Testing (open access)

Interim Report on Uranium Metal Segregation Testing

This report describes the preliminary results of laboratory and bench-scale vendor testing to evaluate the effectiveness of the gravity mineral concentration technology for removing and concentrating uranium metal from K Basin sludge.
Date: April 18, 2004
Creator: Schmidt, Andrew J. & Elmore, Monte R.
System: The UNT Digital Library
Baseline Inputs for BEAMS: Data used in preparing Methodological Framework for Analysis of Building-Related Programs: The GPRA Metrics Effort, June 2004 (open access)

Baseline Inputs for BEAMS: Data used in preparing Methodological Framework for Analysis of Building-Related Programs: The GPRA Metrics Effort, June 2004

This report contains the appendix to the PNNL report, Methodological Framework for Analysis of Buildings-Related Programs: The GPRA Metrics Effort.
Date: June 18, 2004
Creator: Elliott, Douglas B.; Anderson, Dave M.; Belzer, David B.; Cort, Katherine A.; Dirks, James A. & Hostick, Donna J.
System: The UNT Digital Library
Pin Wire Coating Trip Report (open access)

Pin Wire Coating Trip Report

A meeting to discuss the current pin wire coating problems was held at the Reynolds plant in Los Angeles on 2MAR04. The attendance list for Reynolds personnel is attached. there was an initial presentation which gave a brief history and the current status of pin wire coating at Reynolds. There was a presentation by Lori Primus on the requirements and issues for the coating. There was a presentation by Jim Smith of LANL on the chemistry and to some extent process development done to date. There was a long session covering what steps should be taken in the short term and, to a lesser extent, the long term. The coating currently being used is a blend of two polymers, polyethersulfone and polyparabanic acid (PPA) and some TiO2 filler. This system was accepted and put into production when the pin wire coating was outsourced to another company in 1974. When that company no longer was interested, the wire coating was brought in-house to Reynolds. At that time polyparabanic acid was actually a commercial product available from Exxon under the trade name Tradlon. However, it appears that the material used at Reynolds was synthesized locally. Also, it appears that a single large …
Date: March 18, 2004
Creator: Spellman, G P
System: The UNT Digital Library
Microstructural Origins of Dynamic Fracture in Ductile Metals (open access)

Microstructural Origins of Dynamic Fracture in Ductile Metals

Dynamic fracture is a material failure process at high strain-rates. Here, we limit our discussion to spallation fracture during shock wave loading. When a compressive shock wave reflects from a free surface, internal states of tension are created. If this tension exceeds the rupture strength of the material, it fails by nucleating and growing microscopic voids in ductile metals and cracks in brittle solids. This effect, known as spallation, was reported by Hopkinson in 1872 [1]. Rinehart and Pierson [2] give an historical introduction to spallation and other aspects of high strain-rate deformation. This phenomenology of the nucleation and growth of microscopic voids is common to all fracture in ductile metals, including dynamic fracture. The importance of pulse duration was not fully appreciated until the 1960's through the work of Butcher and colleagues [3, 4], leading to the concept of cumulative damage. This concept of damage accumulation was put on a strong experimental foundation by Barbee et al. [5], who performed gas gun recovery experiments and tediously measured the size and distribution of microscopic flaws using 2D microscopy. The resulting continuum material model of dynamic fracture is known as the SRI-NAG model [6, 7], for Nucleation And Growth. In a …
Date: February 18, 2004
Creator: Belak, J; Cazamias, J U; Fivel, M; Haupt, D; Kinney, J H; Kumar, M et al.
System: The UNT Digital Library
Bubble merger model for the nonlinear Rayleigh-Taylor instability driven by a strong blast wave (open access)

Bubble merger model for the nonlinear Rayleigh-Taylor instability driven by a strong blast wave

A bubble merger model is presented for the nonlinear evolution of the Rayleigh-Taylor instability driven by a strong blast wave. Single bubble motion is determined by an extension of previous buoyancy-drag models extended to the blast wave driven case, and a simple bubble merger law in the spirit of the Sharp-Wheeler model allows for the generation of larger scales. The blast wave driven case differs in several respects from the classical case of incompressible fluids in a uniform gravitational field. Because of material decompression in the rarefaction behind the blast front, the asymptotic bubble velocity and the merger time depend on time as well as the transverse scale and the drive. For planar blast waves, this precludes the emergence of a self-similar regime independent of the initial conditions. With higher-dimensional blast waves, divergence restores the properties necessary for the establishment of the self-similar state, but its establishment requires a very high initial characteristic mode number and a high Mach number for the incident blast wave.
Date: March 18, 2004
Creator: Miles, A R
System: The UNT Digital Library
Performance of Large NaI(Tl) Gamma-Ray Detectors Over Temperature -50 Degrees C to +60 Degrees C. (open access)

Performance of Large NaI(Tl) Gamma-Ray Detectors Over Temperature -50 Degrees C to +60 Degrees C.

The performance of two large NaI(Tl) scintillation detectors has been determined as a function of detector type and as a function of temperature. One detector had dimensions of 4?4?16 in.3 with a stainless steel shell while the other detector was 2?4?16 in.3 with an aluminum shell. Absolute counting efficiencies for photopeaks and total counts were measured at 0.46 m and 2.0 m for gamma sources ranging in energy from 25 keV to 2500 keV. Photopeak resolutions were measured over the same energy range. The changes in pulse height and photopeak resolution were measured as a function of temperature over the range -50 C to +60 C. As expected from prior literature data, the scintillator light output decreases at both higher and lower temperatures compared to room temperature. However, the maximum peak height in this work occurred at 0 C whereas the literature gives the maximum light output at about 40 C. This difference is attributed to the fact that in this work, the phototubes and preamplifiers were heated and cooled along with the scintillator. Both detectors continued to function successfully over the entire temperature range studied in this work. The pulse height decreased by about 33% at -50 C and …
Date: August 18, 2004
Creator: Reeder, Paul L. & Stromswold, David C.
System: The UNT Digital Library
Computational Methods for Collisional Plasma Physics (open access)

Computational Methods for Collisional Plasma Physics

Modeling the high density, high temperature plasmas produced by intense laser or particle beams requires accurate simulation of a large range of plasma collisionality. Current simulation algorithms accurately and efficiently model collisionless and collision-dominated plasmas. The important parameter regime between these extremes, semi-collisional plasmas, has been inadequately addressed to date. LLNL efforts to understand and harness high energy-density physics phenomena for stockpile stewardship require accurate simulation of such plasmas. We have made significant progress towards our goal: building a new modeling capability to accurately simulate the full range of collisional plasma physics phenomena. Our project has developed a computer model using a two-pronged approach that involves a new adaptive-resolution, ''smart'' particle-in-cell algorithm: complex particle kinetics (CPK); and developing a robust 3D massively parallel plasma production code Z3 with collisional extensions. Our new CPK algorithms expand the function of point particles in traditional plasma PIC models by including finite size and internal dynamics. This project has enhanced LLNL's competency in computational plasma physics and contributed to LLNL's expertise and forefront position in plasma modeling. The computational models developed will be applied to plasma problems of interest to LLNL's stockpile stewardship mission. Such problems include semi-collisional behavior in hohlraums, high-energy-density physics experiments, …
Date: February 18, 2004
Creator: Lasinski, B. F.; Larson, D. J.; Hewett, D. W.; Langdon, A. B. & Still, C. H.
System: The UNT Digital Library
Kinetics of HMX and CP Decomposition and Their Extrapolation for Lifetime Assessment (open access)

Kinetics of HMX and CP Decomposition and Their Extrapolation for Lifetime Assessment

Decomposition kinetics are determined for HMX (nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) and CP (2-(5-cyanotetrazalato) pentaammine cobalt (III) perchlorate) separately and together. For high levels of thermal stress, the two materials decompose faster as a mixture than individually. This effect is observed both in high-temperature thermal analysis experiments and in long-term thermal aging experiments. An Arrhenius plot of the 10% level of HMX decomposition by itself from a diverse set of experiments is linear from 120 to 260 C, with an apparent activation energy of 165 kJ/mol. Similar but less extensive thermal analysis data for the mixture suggests a slightly lower activation energy for the mixture, and an analogous extrapolation is consistent with the amount of gas observed in the long-term detonator aging experiments, which is about 30 times greater than expected from HMX by itself for 50 months at 100 C. Even with this acceleration, however, it would take {approx}10,000 years to achieve 10% decomposition at {approx}30 C. Correspondingly, negligible decomposition is predicted by this kinetic model for a few decades aging at temperatures slightly above ambient. This prediction is consistent with additional sealed-tube aging experiments at 100-120 C, which are estimated to have an effective thermal dose greater than that from decades …
Date: November 18, 2004
Creator: Burnham, A K; Weese, R K & Andrzejewski, W J
System: The UNT Digital Library
PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 57, HIGH PT PHYSICS AT RHIC, DECEMBER 2-6, 2003 (open access)

PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 57, HIGH PT PHYSICS AT RHIC, DECEMBER 2-6, 2003

The AuAu, dAu, and pp collision modes of the RHIC collider at BNL have led to the publication of exciting high p{perpendicular} particle production data. There have also been two physics runs with polarized protons, and preliminary results on the double-spin asymmetry for pion production had been presented very recently. The ontological questions behind these measurements are fascinating: Did RHIC collisions create a Quark-Gluon-Plasma phase and did they verify the Color Glass Condensate as the high energy limit of QCD? Will the Spin Crisis finally be resolved in terms of gluon polarization and what new surprises are we yet to meet for Transverse Spin? Phenomena related to sub-microscopic questions as important as these call for interpretations that are footed in solid theory. At large p{perpendicular}, perturbative concepts are legitimately expected to provide useful approaches. The corresponding hard parton dynamics are, in several ways, key to unraveling the initial or final state and collisional phase of hard scattering events in vacuum as well as in hot or cold nuclear matter. Before the advent of RHIC data, a RIKEN-BNL workshop had been held at BNL in March 1999 on ''Hard Parton Physics in High Energy Nuclear Collisions''. The 2003 workshop on ''High …
Date: February 18, 2004
Creator: KRETZER,S. MORRISON,D. VENUGOPALAN,R. VOGELSANG,W.
System: The UNT Digital Library
Weighted Essentially Non-Oscillatory Simulations and Modeling of Complex Hydrodynamic Flows Part 1. Regular Shock Refraction (open access)

Weighted Essentially Non-Oscillatory Simulations and Modeling of Complex Hydrodynamic Flows Part 1. Regular Shock Refraction

Shock refraction is a fundamental shock phenomenon observed when shocks interact with a material interface separating gases with different properties. Following refraction, a transmitted shock enters the second gas and a reflected wave returns back into the first gas. In the case of regular shock refraction all waves meet at a single point called the triple-point, creating five different states for the two gases. Analytical methods based on shock polar analysis [9, 16] have been developed to determine the state of two ideal gases in each of the five refraction regions. Furthermore, shock refraction constitutes a basic example of complex hydrodynamic flows. For this reason, shock refraction is used in this report as one validation of the high-order accurate weighted essentially non-oscillatory (WENO) shock-capturing method, as implemented in the HOPE code. The following two-step validation process is adopted. First, analytical results are obtained for the normal and oblique shock refraction (with shock-interface angle {beta}{sub int} = 75) observed for a Ma = 1.2 shock. To validate the single-fluid and the two-fluid implementations of the WENO method, two pairs of gases, argon/xenon, having equal adiabatic exponents {gamma} and air(acetone)/sulfur hexafluoride, having different adiabatic exponents {gamma}, are considered. Both the light-to-heavy and …
Date: June 18, 2004
Creator: Schilling, O & Latini, M
System: The UNT Digital Library
Frontiers in Microbiology: Envisioning a Curriculum Unit for High School Biology (open access)

Frontiers in Microbiology: Envisioning a Curriculum Unit for High School Biology

Microbiology is undergoing a quiet revolution. Techniques such as polymerase chain reaction, high throughput DNA sequencing, whole genome shotgun sequencing, DNA microarrays, and bioinformatics analyses are greatly aiding our understanding of the estimated one billion species of microbes that inhabit the Earth. Unfortunately, the rapid pace of research in microbiology stands in contrast to the much slower pace of change in educational reform. Biological Sciences Curriculum Study (BSCS) hosted a two-day planning meeting to discuss whether or not a new curriculum unit on microbiology is desirable for the high school audience. Attending the meeting were microbiologists, high school biology teachers, and science educators. The consensus of the participants was that an inquiry-based unit dealing with advances in microbiology should be developed for a high school biology audience. Participants established content priorities for the unit, discussed the unit's conceptual flow, brainstormed potential student activities, and discussed the role of educational technology for the unit. As a result of the planning meeting discussions, BSCS staff sought additional funding to develop, disseminate, and evaluate the Frontiers in Microbiology curriculum unit. This unit was intended to be developed as a replacement unit suitable for an introductory biology course. The unit would feature inquiry-based student …
Date: June 18, 2004
Creator: Bloom, Mark
System: The UNT Digital Library
GMG: A Guaranteed, Efficient Global Optimization Algorithm for Remote Sensing. (open access)

GMG: A Guaranteed, Efficient Global Optimization Algorithm for Remote Sensing.

The monocular passive ranging (MPR) problem in remote sensing consists of identifying the precise range of an airborne target (missile, plane, etc.) from its observed radiance. This inverse problem may be set as a global optimization problem (GOP) whereby the difference between the observed and model predicted radiances is minimized over the possible ranges and atmospheric conditions. Using additional information about the error function between the predicted and observed radiances of the target, we developed GMG, a new algorithm to find the Global Minimum with a Guarantee. The new algorithm transforms the original continuous GOP into a discrete search problem, thereby guaranteeing to find the position of the global minimum in a reasonably short time. The algorithm is first applied to the golf course problem, which serves as a litmus test for its performance in the presence of both complete and degraded additional information. GMG is further assessed on a set of standard benchmark functions and then applied to various realizations of the MPR problem.
Date: August 18, 2004
Creator: D'Helon, CD
System: The UNT Digital Library
Sensitivity Analysis Applied to the Validation of the 10 B Capture Reaction in Nuclear Fuel Casks (open access)

Sensitivity Analysis Applied to the Validation of the 10 B Capture Reaction in Nuclear Fuel Casks

Boron has commonly been used in nuclear fuel casks to ensure a sufficient margin of subcriticality. The amount of boron used in most casks far exceeds the amount of boron present in any of the available benchmark experiments. Such heavy loadings of boron in the casks may result in considerable spectral differences as compared to the benchmarks, resulting in boron sensitivities that are very different from those of the benchmarks. Before the calculations to determine the nuclear safety margin for various fuel loadings are deemed acceptable, as part of the safety basis, the computer code and cross sections must be validated against experimental benchmarks that cover the area of applicability of the proposed cask design. Therefore, this study was performed to determine if these available benchmarks can be used to validate a criticality code and neutron cross sections for the fuel casks. The sensitivity/uncertainty methodology has been applied to several application cask systems with different boron areal densities. Although, the sensitivities of the nuclear fuel cask applications are not completely covered by the set of benchmarks that were used in this study with regard to the 10B capture cross section, the effect of this lack of coverage on the keff …
Date: March 18, 2004
Creator: Goluoglu, Sedat
System: The UNT Digital Library