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Associated {Lambda} production at Jefferson Lab (open access)

Associated {Lambda} production at Jefferson Lab

The {sup 1}H(e, e{prime}K{sup +}){Lambda} and {sup 1}H(e, e{prime}K{sup +}){Sigma}{sup 0} reactions were studied as a function of the squared four-momentum-transfer, Q{sup 2}, and the virtual photon polarization, {var_epsilon}, thus enabling the separation of the longitudinal and transverse parts of the cross section. The existence of a sensibly large longitudinal component for the {sup 1}H(e, e{prime}K{sup +}){Lambda} reaction seems to be sustained by these data.
Date: December 31, 1997
Creator: Niculescu, G.; Baker, O. K.; Avery, S. & Collaboration, E93018
Object Type: Article
System: The UNT Digital Library
Asteroseismology of DAV White Dwarf Stars (open access)

Asteroseismology of DAV White Dwarf Stars

The author reviews the seismological structural determinations of ZZ Ceti stars done to date, and supplement these with additional preliminary determinations of his own. He compares the constraints on the hydrogen layer mass to see what trends emerge and also determines if the observed hydrogen layer masses are consistent with proposed theories. He then looks ahead to the prospects of further DAV white dwarf seismology.
Date: December 31, 1997
Creator: Bradley, Paul A.
Object Type: Article
System: The UNT Digital Library
Atomic collision databases and data services -- A survey (open access)

Atomic collision databases and data services -- A survey

Atomic collision databases and data services constitute an important resource for scientific and engineering applications such as astrophysics, lighting, materials processing, and fusion energy, as well as an important knowledge base for current developments in atomic collision physics. Data centers and research groups provide these resources through a chain of efforts that include producing and collecting primary data, performing evaluation of the existing data, deducing scaling laws and semiempirical formulas to compactly describe and extend the data, producing the recommended sets of data, and providing convenient means of maintaining, updating, and disseminating the results of this process. The latest efforts have utilized modern database, storage, and distribution technologies including the Internet and World Wide Web. Given here is an informal survey of how these resources have developed, how they are currently characterized, and what their likely evolution will lead them to become in the future.
Date: December 31, 1997
Creator: Schultz, D.R.
Object Type: Article
System: The UNT Digital Library
Automatic tuning of the reinforcement function (open access)

Automatic tuning of the reinforcement function

The aim of this work is to present a method that helps tuning the reinforcement function parameters in a reinforcement learning approach. Since the proposal of neural based implementations for the reinforcement learning paradigm (which reduced learning time and memory requirements to realistic values) reinforcement functions have become the critical components. Using a general definition for reinforcement functions, the authors solve, in a particular case, the so called exploration versus exploitation dilemma through the careful computation of the RF parameter values. They propose an algorithm to compute, during the exploration part of the learning phase, an estimate for the parameter values. Experiments with the mobile robot Nomad 200 validate their proposals.
Date: December 31, 1997
Creator: Touzet, Claude & Santos, Juan Miguel
Object Type: Article
System: The UNT Digital Library
Base program on energy related research. Quarterly report, August 1--October 31, 1997 (open access)

Base program on energy related research. Quarterly report, August 1--October 31, 1997

The Base Research Program at Western Research Institute (WRI) is planned to develop technologies to a level that will attract industrial sponsors for continued development under the Jointly Sponsored Research (JSR) Program. The goals of the JSR and Base Programs are accomplished by focusing research, development, demonstration, and commercialization in three major technology areas: energy programs emphasize the increased production and utilization of domestic energy resources and include enhanced oil recovery, coal beneficiation and upgrading, coalbed methane recovery, and renewable energy resources; environmental programs minimize the impact of energy production and utilization by providing technology to clean underground oily wastes, mitigate acid mine drainage, and demonstrate uses for clean coal technology (CCT) and pressurized fluidized bed combustion (PFBC) waste solids; technology enhancement activities encompass resource characterization studies, the development of improved environmental monitors and sensors, and improved techniques and models for predicting the dispersion of hazardous gas releases. Significant accomplishments under the Base Research program are reported.
Date: December 31, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 76, No. 52, Ed. 1 Wednesday, December 31, 1997 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 76, No. 52, Ed. 1 Wednesday, December 31, 1997

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: December 31, 1997
Creator: Dobbs, Gary
Object Type: Newspaper
System: The Portal to Texas History
Benchmarking and Performance Improvement at Rocky Flats Environmental Technology Site (open access)

Benchmarking and Performance Improvement at Rocky Flats Environmental Technology Site

The Rocky Flats Environmental Technology Site (RFETS) has initiated a major work process improvement campaign using the tools of formalized benchmarking and streamlining. This paper provides insights into some of the process improvement activities performed at Rocky Flats from November 1995 through December 1996. It reviews the background, motivation, methodology, results, and lessons learned from this ongoing effort. The paper also presents important gains realized through process analysis and improvement including significant cost savings, productivity improvements, and an enhanced understanding of site work processes.
Date: December 31, 1997
Creator: Elliott, C.
Object Type: Article
System: The UNT Digital Library
Benefits of rapid solidification processing of modified LaNi{sub 5} alloys by high pressure gas atomization for battery applications (open access)

Benefits of rapid solidification processing of modified LaNi{sub 5} alloys by high pressure gas atomization for battery applications

A high pressure gas atomization approach to rapid solidification has been employed to investigate simplified processing of Sn modified LaNi{sub 5} powders that can be used for advanced Ni/metal hydride (Ni/MH) batteries. The current industrial practice involves casting large ingots followed by annealing and grinding and utilizes a complex and costly alloy design. This investigation is an attempt to produce powders for battery cathode fabrication that can be used in an as-atomized condition without annealing or grinding. Both Ar and He atomization gas were tried to investigate rapid solidification effects. Sn alloy additions were tested to promote subambient pressure absorption/desorption of hydrogen at ambient temperature. The resulting fine, spherical powders were subject to microstructural analysis, hydrogen gas cycling, and annealing experiments to evaluate suitability for Ni/MH battery applications. The results demonstrate that a brief anneal is required to homogenize the as-solidified microstructure of both Ar and He atomized powders and to achieve a suitable hydrogen absorption behavior. The Sn addition also appears to suppress cracking during hydrogen gas phase cycling in particles smaller than about 25 {micro}m. These results suggest that direct powder processing of a LaNi{sub 5{minus}x}Sn{sub x} alloy has potential application in rechargeable Ni/MH batteries.
Date: December 31, 1997
Creator: Anderson, I.E.; Pecharsky, V.K.; Ting, J.; Witham, C. & Bowman, R.C.
Object Type: Report
System: The UNT Digital Library
Biochemical removal of HAP precursors from coal. Quarterly technical progress report, April--June 1996 (open access)

Biochemical removal of HAP precursors from coal. Quarterly technical progress report, April--June 1996

Analytical methods were finalized and all analyses completed on shake flask tests with Indiana No. 5 and Pittsburgh No. 8 coal. A column leaching-rotating biological contractor (RBC) unit was used to bioleach pyrite and hazardous air pollutant precursors from Pittsburgh No. 8 coal. Shake flask tests with Rosebud subbituminous coal were begun. In connection with upcoming slurry column reactor tests, coal was prepared and shipped to INEL, and a detailed work plan was developed for operation and sampling for the tests. A manuscript and poster was prepared for presentation at the PETC contractors conference.
Date: December 31, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Bioenergetic studies of coal sulfur oxidation by extremely thermophilic bacteria. Final report, September 15, 1992--August 31, 1997 (open access)

Bioenergetic studies of coal sulfur oxidation by extremely thermophilic bacteria. Final report, September 15, 1992--August 31, 1997

Thermoacidophilic microorganisms have been considered for inorganic sulfur removal from coal because of expected improvements in rates of both biotic and abiotic sulfur oxidation reactions with increasing temperature. In this study, the bioenergetic response of the extremely thermoacidophilic archaeon, Metallosphaera sedula, to environmental changes have been examined in relation to its capacity to catalyze pyrite oxidation in coal. Given an appropriate bioenergetic challenge, the metabolic response was to utilize additional amounts of energy sources (i.e., pyrite) to survive. Of particular interest were the consequences of exposing the organism to various forms of stress (chemical, nutritional, thermal, pH) in the presence of coal pyrite. Several approaches to take advantage of stress response to accelerate pyrite oxidation by this organism were examined, including attempts to promote acquired thermal tolerance to extend its functional range, exposure to chemical uncouplers and decouplers, and manipulation of heterotrophic and chemolithotrophic tendencies to optimize biomass concentration and biocatalytic activity. Promising strategies were investigated in a continuous culture system. This study identified environmental conditions that promote better coupling of biotic and abiotic oxidation reactions to improve biosulfurization rates of thermoacidophilic microorganisms.
Date: December 31, 1997
Creator: Kelly, R. M. & Han, C. J.
Object Type: Report
System: The UNT Digital Library
Biomass Cofiring with Coal at Seward, Pennsylvania (open access)

Biomass Cofiring with Coal at Seward, Pennsylvania

The first test under the EPRI/FETC biomass cofiring process was at GPU Genco`s 32-MW{sub e} pulverized coal boiler at Seward, Pennsylvania. The unit used in the test (Boiler 12) is a wall-fired boiler built by Babcock & Wilcox, and has a nominal steaming capacity of 300,000 lb/hr of 675 psig/850 F stream. The furnace of Boiler 12 has a volume of 20,000 ft{sup 3} and has a volume in the primary combustion area of 12,700 ft{sup 3}. The boiler has two rows of burners, with three burners installed on each row. Typically it consumes coal at about 14 ton/hr when firing at 100 percent of capacity. This boiler, along with Boiler 14, supply steam to a 64 MW{sub e} Westinghouse turbine. The net station heat rate (NSHR) for Boilers 12 and 14, and the associated turbine, is 14,200 Btu/kWh. Boiler 14 has been used to test coal water slurry (CWS), and that experience contributed to the design and execution of this cofiring test, where sawdust was the biomass fuel.
Date: December 31, 1997
Creator: Huges, E.; Battista, J. & Tillman, D
Object Type: Report
System: The UNT Digital Library
Boise geothermal injection well: Final environmental assessment (open access)

Boise geothermal injection well: Final environmental assessment

The City of Boise, Idaho, an Idaho Municipal Corporation, is proposing to construct a well with which to inject spent geothermal water from its hot water heating system back into the geothermal aquifer. Because of a cooperative agreement between the City and the US Department of Energy to design and construct the proposed well, compliance to the National Environmental Policy Act (NEPA) is required. Therefore, this Environmental Assessment (EA) represents the analysis of the proposed project required under NEPA. The intent of this EA is to: (1) briefly describe historical uses of the Boise Geothermal Aquifer; (2) discuss the underlying reason for the proposed action; (3) describe alternatives considered, including the No Action Alternative and the Preferred Alternative; and (4) present potential environmental impacts of the proposed action and the analysis of those impacts as they apply to the respective alternatives.
Date: December 31, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Boron nitride coatings and materials for use in aggressive environments (open access)

Boron nitride coatings and materials for use in aggressive environments

Boron nitride coatings and structures have demonstrated significant resistance to many corrosive environments. These coatings may have application in the protection of sensors needed for measuring a variety of properties such as temperature and chemistry. In addition, boron nitride materials may offer advantages as structural materials in high temperature materials processing. In this study, BN is assessed for use in aluminum smelting.
Date: December 31, 1997
Creator: Besmann, T.M.; Lee, W.Y.; Young, J.P. & Xiao, H.
Object Type: Report
System: The UNT Digital Library
Calculations on Electron Capture in Low Energy Ion-Molecule Collisions (open access)

Calculations on Electron Capture in Low Energy Ion-Molecule Collisions

Recent progress on the application of a quantal, molecular-orbital, close-coupling approach to the calculation of electron capture in collisions of multiply charged ions with molecules is discussed. Preliminary results for single electron capture by N{sup 2+} with H{sub 2} are presented. Electron capture by multiply charged ions colliding with H{sub 2} is an important process in laboratory and astrophysical plasmas. It provides a recombination mechanism for multiply charged ions in x-ray ionized astronomical environments which may have sparse electron and atomic hydrogen abundances. In the divertor region of a tokamak fusion device, charge exchange of impurity ions with H{sub 2} plays a role in the ionization balance and the production of radiative energy loss leading to cooling, X-ray and ultraviolet auroral emission from Jupiter is believed to be due to charge exchange of O and S ions with H{sub 2} in the Jovian atmosphere. Solar wind ions interacting with cometary molecules may have produced the x-rays observed from Comet Hyakutake. In order to model and understand the behavior of these environments, it is necessary to obtain total, electronic state-selective (ESS), and vibrational (or rotational) state-selective (VSS) capture cross sections for collision energies as low as 10 meV/amu to as high …
Date: December 31, 1997
Creator: Stancil, P. C.; Zygelman, B. & Kirby, K.
Object Type: Article
System: The UNT Digital Library
Cascade Multilevel Inverters for Utility Applications (open access)

Cascade Multilevel Inverters for Utility Applications

Cascade multilevel inverters have been developed by the authors for utility applications. A cascade M-level inverter consists of (M-1)/2 H- bridges in which each bridge has its own separate dc source. The new inverter: (1) can generate almost sinusoidal waveform voltage while only switching one time per fundamental cycle, (2) can eliminate transformers of multipulse inverters used in conventional utility interfaces and static var compensators, and (3) makes possible direct parallel or series connection to medium- and high-voltage power systems without any transformers. In other words, the cascade inverter is much more efficient and suitable for utility applications than traditional multipulse and pulse width modulation (PWM) inverters. The authors have experimentally demonstrated the superiority of the new inverter for reactive power (var) and harmonic compensation. This paper will summarize features,feasibility, and control schemes of the cascade inverter for utility applications including utility interface of renewable energy, voltage regulation, var compensation, and harmonic filtering in power systems.Analytical, simulated, and experimental results demonstrate the superiority of the new inverters.
Date: December 31, 1997
Creator: Peng, F.Z., McKeever, J.W., Adams, D.J.
Object Type: Article
System: The UNT Digital Library
Cask crush pad analysis using detailed and simplified analysis methods (open access)

Cask crush pad analysis using detailed and simplified analysis methods

A crush pad has been designed and analyzed to absorb the kinetic energy of a hypothetically dropped spent nuclear fuel shipping cask into a 44-ft. deep cask unloading pool at the Fluorinel and Storage Facility (FAST). This facility, located at the Idaho Chemical Processing Plant (ICPP) at the Idaho national Engineering and Environmental Laboratory (INEEL), is a US Department of Energy site. The basis for this study is an analysis by Uldrich and Hawkes. The purpose of this analysis was to evaluate various hypothetical cask drop orientations to ensure that the crush pad design was adequate and the cask deceleration at impact was less than 100 g. It is demonstrated herein that a large spent fuel shipping cask, when dropped onto a foam crush pad, can be analyzed by either hand methods or by sophisticated dynamic finite element analysis using computer codes such as ABAQUS. Results from the two methods are compared to evaluate accuracy of the simplified hand analysis approach.
Date: December 31, 1997
Creator: Uldrich, E.D. & Hawkes, B.D.
Object Type: Article
System: The UNT Digital Library
The Cassini project: Lessons learned through operations (open access)

The Cassini project: Lessons learned through operations

The Cassini space probe requires 180 {sup 238}Pu Light-weight Radioisotopic Heater Units (LWRHU) and 216 {sup 238}Pu General Purpose Heat Source (GPHS) pellets. Additional LWRHU and GPHS pellets required for non-destructive (NDA) and destructive assay purposes were fabricated bringing the original pellet requirement to 224 LWRHU and 252 GPHS. Due to rejection of pellets resulting from chemical impurities in the fuel and/or failure to meet dimensional specifications a total of 320 GPHS pellets were fabricated for the mission. Initial plans called for LANL to process a total of 30 kg of oxide powder for pressing into monolithic ceramic pellets. The original 30 kg commitment was processed within the time frame allotted; an additional 8 kg were required to replace fuel lost due to failure to meet Quality Assurance specifications for impurities and dimensions. During the time frame allotted for pellet production, operations were impacted by equipment failure, unacceptable fuel impurities levels, and periods of extended down time, > 30 working days during which little or no processing occurred. Throughout and production process, the reality of operations requirements varied from the theory upon which production schedules were based.
Date: December 31, 1997
Creator: McCormick, E.D.
Object Type: Article
System: The UNT Digital Library
Die casting research: Die cavity instrumentation. Final report, Tasks 2--5 (open access)

Die casting research: Die cavity instrumentation. Final report, Tasks 2--5

The primary objective of this project was to evaluate the performance characteristics and usefulness of near cavity temperature, liquid pressure, and gas flow rate sensors for improved monitoring and control of die casting processes. Three types of near cavity sensors were evaluated: a multi-thermocouple probe used for determining the surface and near-cavity thermal history of the die; a commercially available direct cavity pressure sensor for measuring the pressure history of the liquid and solidifying alloy in the die cavity; and a vent gas flow sensor for monitoring whether gas exits the cavity vent during cavity filling.
Date: December 31, 1997
Creator: Mobley, C. E. & Brevick, J.
Object Type: Report
System: The UNT Digital Library
Caustic leaching of high-level radioactive tank sludge: A critical literature review (open access)

Caustic leaching of high-level radioactive tank sludge: A critical literature review

The Department of Energy (DOE) must treat and safely dispose of its radioactive tank contents, which can be separated into high-level waste (HLW) and low-level waste (LLW) fractions. Since the unit costs of treatment and disposal are much higher for HLW than for LLW, technologies to reduce the amount of HLW are being developed. A key process currently being studied to reduce the volume of HLW sludges is called enhanced sludge washing (ESW). This process removes, by water washes, soluble constituents such as sodium salts, and the washed sludge is then leached with 2--3 M NaOH at 60--100 C to remove nonradioactive metals such as aluminum. The remaining solids are considered to be HLW while the solutions are LLW after radionuclides such as {sup 137}Cs have been removed. Results of bench-scale tests have shown that the ESW will probably remove the required amounts of inert constituents. While both experimental and theoretical results have shown that leaching efficiency increases as the time and temperature of the leach are increased, increases in the caustic concentration above 2--3 M will only marginally improve the leach factors. However, these tests were not designed to validate the assumption that the caustic used in the ESW …
Date: December 31, 1997
Creator: McGinnis, C. P.; Welch, T. D. & Hunt, R. D.
Object Type: Article
System: The UNT Digital Library
Certification of the Cessna 152 on 100% ethanol (open access)

Certification of the Cessna 152 on 100% ethanol

In June 1996, the Renewable Aviation Fuels Development Center (RAFDC) at Baylor University in Waco, Texas, received a Supplemental Type Certificate (STC) for the use of 100% ethanol as a fuel for the Cessna 152, the most popular training aircraft in the world. This is the first certification granted by the Federal Aviation Administration (FAA) for a non-petroleum fuel. Certification of an aircraft on a new fuel requires a certification of the engine followed by a certification of the airframe/engine combination. This paper will describe the FAA airframe certification procedure, the tests required and their outcome using ethanol as an aviation fuel in a Cessna 152.
Date: December 31, 1997
Creator: Shauck, M. E. & Zanin, M. G.
Object Type: Article
System: The UNT Digital Library
CFCC working group meeting: Proceedings (open access)

CFCC working group meeting: Proceedings

This report is a compilation of the vugraphs presented at this meeting. Presentations covered are: CFCC Working Group; Overview of study on applications for advanced ceramics in industries for the future; Design codes and data bases: The CFCC program and its involvement in ASTM, ISO, ASME, and military handbook 17 activities; CFCC Working Group meeting (McDermott Technology); CFCC Working Group meeting (Textron); CFCC program for DMO materials; Developments in PIP-derived CFCCs; Toughened Silcomp (SiC-Si) composites for gas turbine engine applications; CFCC program for CVI materials; Self-lubricating CFCCs for diesel engine applications; Overview of the CFCC program`s supporting technologies task; Life prediction methodologies for CFCC components; Environmental testing of CFCCs in combustion gas environments; High-temperature particle filtration ORNL/DCC CRADA; HSCT CMC combustor; and Case study -- CFCC shroud for industrial gas turbines.
Date: December 31, 1997
Creator: unknown
Object Type: Article
System: The UNT Digital Library
Char particle fragmentation and its effect on unburned carbon during pulverized coal combustion. Final report, March 20, 1997 (open access)

Char particle fragmentation and its effect on unburned carbon during pulverized coal combustion. Final report, March 20, 1997

This document is the final report of work on a project concerned with the fragmentation of char particles during pulverized coal combustion that was conducted at the High Temperature Gasdynamics Laboratory at Stanford University, Stanford, California. The project is intended to satisfy, in part, PETC`s research efforts to understand the chemical and physical processes that govern coal combustion. The overall objectives of the project were: (1) to characterize the fragmentation events as a function of combustion environment, (2) to characterize fragmentation with respect to particle porosity and mineral loadings, (3) to assess overall mass loss rates with respect to particle fragmentation, and (4) to quantify the impact of fragmentation on unburned carbon in ash. The knowledge obtained during the course of this project can be used to predict accurately the overall mass loss rates of coals based on both the physical and chemical characteristics of their chars. The work provides a means of assessing reasons for unburned carbon in the ash of coal fired boilers and furnaces.
Date: December 31, 1997
Creator: Mitchell, R.E.
Object Type: Report
System: The UNT Digital Library
Characteristics of shear damage for 60Sn-40Pb solder material (open access)

Characteristics of shear damage for 60Sn-40Pb solder material

This paper presents an investigation of the development of a continuum damage model capable of accurately analyzing shear damage in 60Sn-40Pb solder material. Based on the theory of damage mechanics, an internal state variable known as the damage variable is introduced to characterize material degradation caused by the change of material microstructures under load. A damage surface in stress space is proposed to quantify damage initiation and its successive expanding surfaces to represent damage hardening. With the aid of irreversible thermodynamics, the damage-coupled constitutive equations and the damage evolution equations are established. A failure criterion is proposed based on the accumulation of overall damage in the material. The damage model is implemented in a general purpose finite element program ABAQUS through its user-defined material subroutine UMAT. The program is applied to predict shear deformation in a notched specimen. The predicted failure mode and maximum load agree well with those measured experimentally. The effect of finite element meshing on the numerical results is also examined and discussed.
Date: December 31, 1997
Creator: Fang, H.E.; Chow, C.L. & Wei, Y.
Object Type: Report
System: The UNT Digital Library
A characterization and evaluation of coal liquefaction process streams. Quarterly report, April 1--June 30, 1997 (open access)

A characterization and evaluation of coal liquefaction process streams. Quarterly report, April 1--June 30, 1997

This is the Technical Progress Report for the twelfth quarter of activities. Described in this report are the following activities: (1) Thirty-nine samples from four run conditions of HTI Run PB-07 were received. Appropriate samples were characterized by proton NMR spectroscopy, Fourier transform infrared spectroscopy, vacuum distillation, and solvent quality tests. (2) The University of Delaware completed their subcontract this quarter. A meeting was held on April 30, 1997 at the University to close out the subcontract. (3) Twelve sets of samples were chosen from the CONSOL sample bank for the study of the insoluble and presumed unreactive material from process stream samples. Each set consists of the whole process stream and the 454 C{sup +} (850 F{sup +}) distillation resid derived from that process stream. Processing data for all samples were compiled. The samples represent four Wilsonville pilot plant runs and two HTI runs.
Date: December 31, 1997
Creator: Brandes, S. D.; Robbins, G. A. & Winschel, R. A.
Object Type: Report
System: The UNT Digital Library