Development of improved cathodes for solid oxide fuel cells (open access)

Development of improved cathodes for solid oxide fuel cells

The University of Missouri-Rolla conducted a 17 month research program focused on the development and evaluation of improved cathode materials for solid oxide fuel cells (SOFC). The objectives of this program were: (1) the development of cathode materials of improved stability in reducing environments; and (2) the development of cathode materials with improved electrical conductivity. The program was successful in identifying some potential candidate materials: Air sinterable (La,Ca)(Cr,Co)O{sub 3} compositions were developed and found to be more stable than La{sub .8}Sr{sub .2}MnO{sub 3} towards reduction. Their conductivity at 1000{degrees}C ranged between 30 to 60 S/cm. Compositions within the (Y,Ca)(Cr,Co,Mn)O{sub 3} system were developed and found to have higher electrical conductivity than La{sub .8}Sr{sub .2}MnO{sub 3} and preliminary results suggest that their stability towards reduction is superior.
Date: March 1, 1991
Creator: Anderson, H.U.
Object Type: Report
System: The UNT Digital Library
A survey of air flow models for multizone structures (open access)

A survey of air flow models for multizone structures

Air flow models are used to simulate the rates of incoming and outgoing air flows for a building with known leakage under given weather and shielding conditions. Additional information about the flow paths and air-mass flows inside the building can only by using multizone air flow models. In order to obtain more information on multizone air flow models, a literature review was performed in 1984. A second literature review and a questionnaire survey performed in 1989, revealed the existence of 50 multizone air flow models, all developed since 1966, two of which are still under development. All these programs use similar flow equations for crack flow but differ in the versatility to describe the full range of flow phenomena and the algorithm provided for solving the set of nonlinear equations. This literature review was found that newer models are able to describe and simulate the ventilation systems and interrelation of mechanical and natural ventilation. 27 refs., 2 figs., 1 tab.
Date: March 1, 1991
Creator: Feustel, H.E. & Dieris, J.
Object Type: Report
System: The UNT Digital Library
Optimizing procedures for a human genome repository (open access)

Optimizing procedures for a human genome repository

Large numbers of clones will be generated during the Human Genome Project. As each is characterized, subsets will be identified which are useful to the scientific community at large. These subsets are most readily distributed through public repositories. The American Type Culture Collection (ATCC) is experienced in repository operation, but before this project had no history in managing clones and associated information in large batches instead of individually. This project permitted the ATCC to develop several procedures for automating and thus reducing the cost of characterizing, preserving, and maintaining information about clones.
Date: March 1, 1991
Creator: Nierman, W.C.
Object Type: Report
System: The UNT Digital Library
A method to estimate the concentration of elements in smoke from burning vegetation growing in contaminated soil (open access)

A method to estimate the concentration of elements in smoke from burning vegetation growing in contaminated soil

The Savannah River Site has areas where soil is contaminated with metals and/or radionuclides. Many of these areas are surrounded by native vegetation which is growing adjacent to the area and where the roots have penetrated into the contaminated soil of the area. In some cases vegetation has actually invaded the contaminated area. Even though the volume of contaminated vegetation is small, there are problems associated with its disposal. Vegetation decomposes quickly after burial and the volume of buried vegetation can decrease. The voids left can lead to subsidence and possible failure of the clay cap constructed over hazardous and/or radioactive waste burial grounds. An alternative to burying the wood is to burn it and bury the ash. However, burning will introduce the contamination in the vegetation into the air where there is potential for inhalation of the contaminants. A procedure is described to assess the hazard associated with inhalation of contamination from burning of vegetation growing in contaminated soil. The procedure is applied to evaluation of the consequence of burning vegetation grown adjacent to and in the SRL Seepage Basins. The results indicate that burning the vegetation during the day could introduce a level of contaminants to the atmosphere …
Date: March 4, 1991
Creator: Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
Evaluation of management options for disposal of salt and trace element laden agricultural drainage water from the Fallon Indian Reservation, Fallon, Nevada (open access)

Evaluation of management options for disposal of salt and trace element laden agricultural drainage water from the Fallon Indian Reservation, Fallon, Nevada

This is the final report describing work performed on the Fallon Indian Reservation by the Earth Sciences Division at Lawrence Berkeley Laboratory during FY90. These investigations were initiated at the request of the United States Bureau of Reclamation in response to recent concerns regarding disposal of agriculture drainage water from the Reservation. The Reservation is transected by numerous irrigation and drainage canals, including the TJ Drain. Recent investigations by the US Fish and Wildlife Service have demonstrated that water in the TJ Drain is toxic to several aquatic indicator organisms, including bluegills, fathead minnows and daphnids. This information, coupled with recent die-offs of fish and birds, has lead to concern about continued discharge of TJ Drain water into local surface waters. In late 1990, plans for closing the TJ Drain and providing for alternative drainage were initiated. We aim to provide information for assessing options fro disposal of agricultural drainage water from the Reservation. In particular, our studies focuses on irrigation and drainage of lands currently serviced by the TJ Drain. Options for continued irrigation and drainage of the Reservation fall broadly into two categories: options that provide an alternative to drain water disposal into the SWMA; and options that …
Date: March 1, 1991
Creator: Tokunaga, Tetsu & Benson, S.
Object Type: Report
System: The UNT Digital Library
Demonstration of rapid and sensitive module leak certification for space station freedom (open access)

Demonstration of rapid and sensitive module leak certification for space station freedom

A leak detection and quantification demonstration using perflurocarbon tracer (PFT) technology was successfully performed at the NASA Marshall Space Flight Center on January 25, 1991. The real-time Dual Trap Analyzer (DTA) at one-half hour after the start of the first run gave an estimated leak rate of 0.7 mL/min. This has since been refined to be 1.15 {plus minus} 0.09 mL/min. The leak rates in the next three runs were determined to be 9.8 {plus minus} 0.7, {minus}0.4 {plus minus} 0.3, and 76 {plus minus} 6 mL/min, respectively. The theory on leak quantification in the steady-state and time-dependent modes for a single zone test facility was developed and applied to the above determinations. The laboratory PFT analysis system gave a limit-of-detection (LOD) of 0.05 fL for ocPDCH. This is the tracer of choice and is about 100-fold better than that for the DTA. Applied to leak certification, the LOD is about 0.00002 mL/s (0.000075 L/h), a 5 order-of-magnitude improvement over the original leak certification specification. Furthermore, this limit can be attained in a measurement period of 3 to 4 hours instead of days, weeks, or months. A new Leak Certification Facility is also proposed to provide for zonal (three zones) …
Date: March 1, 1991
Creator: Dietz, R. N. & Goodrich, R. W.
Object Type: Report
System: The UNT Digital Library
Fundamental studies of catalytic gasification (open access)

Fundamental studies of catalytic gasification

Studies of the catalytic steam gasification of carbon solids continued. A considerable number of important findings have been made. Recently limited experimentation has been carried out on the production of C{sub 2} hydrocarbons from methane in the presence of Ca/K/Ni oxide catalysts and of oxygen, carbon and water. The main finding thus far has been that C{sub 2} yields of 10--13% can be obtained at about 600{degrees}C or 150{degrees} lower temperature than described in the literature for similar yields. Yields of 7--10% C{sub 2} hydrocarbons at 99+% selectivity have been obtained. The presence of water and small amounts of oxygen is essential. Yields of this magnitude may be attractive since there is no loss of methane to valueless by-products, no purification of the recycle steam is required and no oxygen is used to burn methane. Further improvement in yields by catalyst and operating conditions modification will be investigated. It is also intended to clarify the chemistry which inhibits burning of methane to carbon oxides. Work is discussed on gasification of petroleum cokes and oxidative methane coupling. 8 figs., 2 tabs.
Date: March 1, 1991
Creator: Heinemann, H. & Somorjai, G.A.
Object Type: Report
System: The UNT Digital Library
3D field harmonics (open access)

3D field harmonics

We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the 3D field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is also used in CAD with modifications more readily available. It is our hope that the format used here for magnetic fields can be used not only as a means of delivering fields but also as a way by which beam dynamics can suggest correction to the conductor geometry. 5 refs., 70 figs.
Date: March 30, 1991
Creator: Caspi, S.; Helm, M. & Laslett, L.J.
Object Type: Report
System: The UNT Digital Library
Cost-Effectiveness of Compact Fluorescent Lighting (open access)

Cost-Effectiveness of Compact Fluorescent Lighting

Compact fluorescent technologies have been steadily improving. There has been increased interest in utilizing compact fluorescents to provide cost-effective energy savings for electric utilities in the residential sector. Several utilities in the United States have already distributed compact fluorescents to consumers free of charge. This study assesses the cost-effectiveness of compact fluorescents from the perspectives of consumers and utilities in the Pacific Northwest, where electricity rates are, on average, the lowest in the United States. The study also assesses cost-effectiveness from a societal perspective. Secondary hearing impacts and the value of reduced emissions of pollutants are incorporated into the analysis. Results indicate that compact fluorescents are more likely to be cost-effective as the perspective upon which they are assessed is broadened. Thus, they are least likely to be viewed as cost-effective by consumers, more likely to be considered cost-effective from a utility perspective, and almost always cost-effective from a societal perspective. Given these differences, is is suggested that policies be developed to capture the societal benefits of compact fluorescent retrofits through alternative regulatory or market mechanisms.
Date: March 1, 1991
Creator: Lesser, J. A. & Byers, R.
Object Type: Report
System: The UNT Digital Library
1991 Conference summary on computing in high energy physics (open access)

1991 Conference summary on computing in high energy physics

The papers presented at the Conference cover a wide range of important issues in software engineering and management. They indicate a trend toward more use of commercial systems and standards. This trend will likely have a significant influence on plans for future systems.
Date: March 1, 1991
Creator: Loken, S.C.
Object Type: Article
System: The UNT Digital Library
The LBL geothermal reservoir technology program (open access)

The LBL geothermal reservoir technology program

The main objective of the DOE/GD-funded Geothermal Reservoir Technology Program at Lawrence Berkeley Laboratory is the development and testing of new and improved methods and tools needed by industry in its effort to delineate, characterize, evaluate, and exploit hydrothermal systems for geothermal energy. This paper summarizes the recent and ongoing field, laboratory, and theoretical research activities being conducted as part of the Geothermal Reservoir Technology Program. 28 refs., 4 figs.
Date: March 1, 1991
Creator: Lippmann, M.J.
Object Type: Article
System: The UNT Digital Library
Ductile-Brittle Transition Temperature testing of tungsten using the three-point bend test (open access)

Ductile-Brittle Transition Temperature testing of tungsten using the three-point bend test

Three-point bend tests were performed to determine the Ductile-Brittle Transition Temperatures (DBTTs) of forged and chemical vapor deposition (CVD) tungsten. Testing was performed under quasi-static conditions at temperatures between 23{degrees}C and 450{degrees}C using a forced-air environmental chamber. Load-displacement data from the three-point bend tests indicated that the constitutive behavior of the materials tested varied considerably. Finite element modeling of the three-point bend test was performed to investigate plastic strains induced in the samples during testing as a function of constitutive behavior. The modeling assumed plane stress conditions in the sample and simple bi-linear elastic-plastic constitutive behavior of the test material. The strains induced in the samples were found to be functions of both the yield stress and work hardening behavior of the materials. The use of the three-point bend test to determine DBTT, and the DBTTs reported for the test materials, are discussed relative to the modeling results. It is concluded that the three-point bend test has some utility in the determination of DBTTs if some caution is used in the selection of test parameters and fixture geometries. However, the three-point bed test does not provide a complete picture of the nature of the ductile-brittle transition. 12 refs., 9 figs.
Date: March 5, 1991
Creator: Lassila, D.H.; Magness, F. & Freeman, D.
Object Type: Report
System: The UNT Digital Library
Alternate design concept for the SSC dipole magnet cryogenic support post (open access)

Alternate design concept for the SSC dipole magnet cryogenic support post

New materials and developments in the field of advanced composites have created the opportunity to take a fresh look into the design of the cryogenic supports for SSC collider dipole cryostats. Although the present reentrant post design meets the structural and thermal requirements, its assembly requires precision and proficiency. The objective of the proposed alternate concept is to reduce the overall cost of the support post by means of simplifying and optimizing its component design and assembly process. The present shrink fitted tube assembly may potentially be replaced by injection molded parts. New resin systems with lower thermal conductivity and high strength properties enable the utilization of automated production techniques such as injection molding and filament winding. This paper will provide analysis and design information for the alternate support post concept and compare its test performance and cost to the present support post. 3 refs., 12 figs., 4 tabs.
Date: March 1, 1991
Creator: Lipski, A.; Nicol, T.H. & Richardson, R.
Object Type: Article
System: The UNT Digital Library
Meson and baryon correlation studies using the PEP-TPC/2. gamma. Facility (open access)

Meson and baryon correlation studies using the PEP-TPC/2. gamma. Facility

Results on vector meson, and strange and charmed-baryon production are presented for data taken during the period 1982--1986 using the TPC/2{gamma} detector at PEP. Vector mesons ({rho}{sup 0}, K{sup *} and {phi}) with 0, 1 and 2 strange quarks are used to obtain redundant measures of strange-quark suppression and of the vector to pseudoscalar ratio in hadronization. Measurements of the production rates of {Lambda}, {Xi}{sup {minus}}, {Omega} and {Xi}{sup *0} hyperons and for the {Lambda}{sub c} and of rapidity correlations between {Lambda}{bar {Lambda}} pairs provide sensitive tests of baryon production in fragmentation models. In addition, two- and three-particle correlations between like sign pions provide further evidence for the Bose-Einstein effect in e{sup +}e{sup {minus}} interactions including the relativistic motion of particle sources. 9 refs., 7 figs.
Date: March 1, 1991
Creator: Ronan, M.T.
Object Type: Article
System: The UNT Digital Library
Status of 4-cm-aperture, 17-m-long SSC dipole magnet R D program at BNL (open access)

Status of 4-cm-aperture, 17-m-long SSC dipole magnet R D program at BNL

Over the last year, several 4-cm-aperture, 17-m-long dipole magnet prototypes were built by Brookhaven National Laboratory (BNL) under contract with the Superconducting Super Collider (SSC) Laboratory. These prototypes are the last phase of a half-decade-long R D program, carried out in collaboration with Fermi National Accelerator Laboratory and Lawrence Berkeley Laboratory, and aimed at demonstrating the feasibility of the SSC main ring magnets. They also lay the ground for the 5-cm aperture dipole magnet program to be started soon. After reviewing the design features of the BNL 4-cm-aperture, 17-m-long dipole magnets, we describe in detail the various steps of their fabrication. For each step, we discuss the parameters that need to be mastered, and we compare the values that were achieved for the five most recent prototypes. The data appear coherent and reproducible, demonstrating that the assembly process in under control. 23 refs., 10 figs., 4 tabs.
Date: March 1, 1991
Creator: Devred, A.; Bush, T.; Coombes, R.; DiMarco, J.; Goodzeit, C.; Kuzminski, J. et al.
Object Type: Article
System: The UNT Digital Library
Re-powering and site recycling in a competitive environment (open access)

Re-powering and site recycling in a competitive environment

Re-powering and site recycling are strategies designed to expand electric generating capacity by using depreciated assets. The resource base for the these strategies is large. By 1995, over 170,000 MW of fossil-fired capacity will be in excess of thirty years old, and approaching the end of its conventional economic lifetime. This paper explores how these assets might be developed using competitive market forces. While some re-powering is being pursued under traditional ratebase regulation, there are four other generic alternatives. These are: (1) utility investment at fixed prices with regulatory pre-approval, (2) utility investment under competitive bidding, (3) utility leasing for private producer development, and (4) utility sale of sites for private producer development. Issues associated with each alternative are explored and illustrated with examples. State regulatory policy will be the critical determinant of whether a market develops for depreciated power plants. Financial incentives will stimulate utilities to re-deploy depreciated assets. This means some form of profit-sharing between customers and shareholders of the grains from asset sales. Different approaches to profit sharing are reviewed. These developments are still in an experimental state, however, and no single approach appears to have emerged as a dominant trend. 36 refs., 1 tab.
Date: March 1, 1991
Creator: Taylor, A. & Kahn, E.P.
Object Type: Report
System: The UNT Digital Library
A progress report on the Berkeley search for distant supernovae to measure. Omega (open access)

A progress report on the Berkeley search for distant supernovae to measure. Omega

Over the past two years, in collaboration with the Anglo-Australian Observatory, we have constructed a prototype version of the hardware and software needed to discover distant supernovae for a measurement of {Omega}, the ratio of the average density of the universe to the critical density. To make this measurement, we will use Type Ia supernova, which are now thought to be adequate standard candles for this purpose. 5 refs.
Date: March 1, 1991
Creator: Pennypacker, C.; Perlmutter, S.; Goldhaber, G.; Marvin, H.; Muller, R. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Center for Particle Astrophysics); Boyle, B.J. (Cambridge Univ. (United Kingdom). Inst. of Astronomy) et al.
Object Type: Article
System: The UNT Digital Library
Summary of the working group 4: Hadron spectroscopy (open access)

Summary of the working group 4: Hadron spectroscopy

This report is a summary of the working group 4 on hadron spectroscopy. The topics covered are: physics motivation; design of spectrometer; status of some existing hadron spectrometers; improvements to LASS; and arguments for/against a LASS-like design.
Date: March 1, 1991
Creator: Crowe, K.M.
Object Type: Article
System: The UNT Digital Library
Circular intensity differential scattering (CIDS) measurements in the soft x-ray region of the spectrum (@16 eV to 500 eV) (open access)

Circular intensity differential scattering (CIDS) measurements in the soft x-ray region of the spectrum (@16 eV to 500 eV)

We propose the use of recently developed techniques of circular intensity differential scattering (CIDS), as extended to the soft x-ray region of the spectrum (16 eV to 500 eV), to study the higher order organization of the eukaryotic chromosome. CIDS is the difference in scattering power of an object when illuminated by right circularly polarized vs. left circularly polarized electromagnetic radiation of arbitrary wavelength. CIDS has been shown to be a very sensitive measure of the helical organization of the scattering object eg. the eukaryotic chromosome. Preliminary results of measurements of samples of bacteriophages and octopus sperm done at SRC, Wisconsin, show the technique to be very sensitive to the dimensional parameters of the particles interrogated by circularly polarized light. 7 refs., 5 figs.
Date: March 1, 1991
Creator: Maestre, M .F.; Bustamante, C.; Snyder, P.; Rowe, E. & Hansen, R.
Object Type: Article
System: The UNT Digital Library
Synchrotron phase transition crossing using an rf harmonic (open access)

Synchrotron phase transition crossing using an rf harmonic

This paper describes a new method of transition crossing in strong focusing proton or heavy ion synchrotrons. Such accelerators have the property that at some energy, frequently within the operating range of the machine, the rotation period of particles within the momentum acceptance range of the machine becomes independent of momentum. 19 refs., 10 figs.
Date: March 1, 1991
Creator: Griffin, J.E.
Object Type: Report
System: The UNT Digital Library
Solid State Division progress report for period ending September 30, 1990 (open access)

Solid State Division progress report for period ending September 30, 1990

This report covers research progress in the Solid State Division from April 1, 1989, to September 30, 1990. During this period, division research programs were significantly enhanced by the restart of the High-Flux Isotope Reactor (HFIR) and by new initiatives in processing and characterization of materials.
Date: March 1, 1991
Creator: Green, P. H. & Hinton, L. W. (eds.)
Object Type: Report
System: The UNT Digital Library
Spin-mapping of coal structures with ESE and ENDOR (open access)

Spin-mapping of coal structures with ESE and ENDOR

Advanced EPR methods have demonstrated cability for study of molecular components (including organic sulfur) in coal. We have constructed a unique Very High Frequency Electron Paramagnetic Resonance (VHF EPR) instrument operating at the W-band (96 GHz), one of only two such instruments in the world, and the only one studying coal. We are employing this instrument, as well as collaborating with scientists at Cornell University who have constructed a 250 GHz EPR spectrometer, to develop a clearer understanding of the relationships between the VHF EPR spectra we observe from Illinois coal and the organic sulfur species present in it. Work this Quarter for this DOE grant (supplemented by a one-year award through the Illinois Center for Research on Sulfur in Coal and also reported to that agency) has focussed on three main area: (1) synthesis and analysis of model systems for thiophenic sulfur species in coal; (2) Electron Spin Echo and VHF EPR of inertinites from an Illinois {number sign}6 coal, as well as evaluation of the sensitivity of the signals from this maceral to oxygen; (3) VHF EPR of iodinated coals. 1 ref., 8 figs.
Date: March 1, 1991
Creator: Belford, R. L. & Clarkson, R. B.
Object Type: Report
System: The UNT Digital Library
Future prospects for networking in the United States (open access)

Future prospects for networking in the United States

When considering networks on the basis of geographical scope (i.e., local to wide area networks), the focus is often on the lower three layers of the International Standards Organization Open Systems Interconnection Reference Model (OSI/RM). By contrast, the upper three layers of the Model deal not so much with transport as with network services that are to a first approximation independent of geographical scope. Using this theme, the paper first discusses United States trends in local, metropolitan, and wide area networks. Following this is a description of computer services needed and advances in services offered by networks; an area of increasing emphasis in the United States. Finally, consideration is given to the impact that such trends may have on high energy physics and US HEPnet. The time horizon considered here is limited to mid-decade or a little beyond because studies of technology forecasting beyond five to six years have been shown to be inaccurate. This paper concentrates on computer networks. Through the mid-1990's there appears to be no significant technical or cost advantage for integrating voice and data. 5 refs., 7 figs.
Date: March 1, 1991
Creator: Lidinsky, W.
Object Type: Article
System: The UNT Digital Library
Design development for the 50mm Superconducting Super Collider dipole cryostat (open access)

Design development for the 50mm Superconducting Super Collider dipole cryostat

The cryostat of a Superconducting Super Collider (SSC) dipole magnet consists of all magnet components except the magnet assembly itself. It serves to support the magnet accurately and reliably within the vacuum vessel, provide all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations, and must be manufacturable at low cost. The major components of the cryostat are the vacuum vessel, thermal shields, multilayer insulation system, cryogenic piping, interconnections, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course their expected operating life. This paper describes the design of the current 50mm SSC collider dipole cryostat and includes discussions on the structural and thermal considerations involved in the development of each of the major systems. Where appropriate, comparisons will be made with the 40mm cryostat. 7 refs., 5 figs., 4 tabs.
Date: March 1, 1991
Creator: Nicol, T.H.
Object Type: Article
System: The UNT Digital Library