A novel approach to highly dispersing catalytic materials in coal for gasification. Second quarterly report, January 1, 1990--March 31, 1990 (open access)

A novel approach to highly dispersing catalytic materials in coal for gasification. Second quarterly report, January 1, 1990--March 31, 1990

This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The work is focused on the elucidation of coal-catalyst precursor interactions in solution and the variables which control the adsorption and dispersion of coal gasification metal catalysts. In order to optimize coal-metal ion interactions and hence maximize catalyst activity, the study examines the surface electrochemistry of a lignite, a subbituminous, and a bituminous coals and their demineralized and oxidized derivatives prior to loading with the catalytic materials. The surface electrical properties of the coals are investigated with the aid of electrophoresis, while the effects of the surface charge on the adsorption of K{sup +} and Ca{sup 2+} are studied by agitating the coals with aqueous solutions of potassium and calcium. Zeta potential studies show that the surfaces of the lignite are negatively charged between about pH2 to 11, the negative charge density increasing with increase in pH. Highly alkaline media promoted calcium adsorption due to high negative charge on the coal, while calcium uptake was inhibited in strongly acidic solutions.
Date: December 31, 1990
Creator: Abotsi, M. K. & Bota, K. B.
Object Type: Report
System: The UNT Digital Library
2DPUF: A sequential gaussian puff model (open access)

2DPUF: A sequential gaussian puff model

This report documents the Environmental Transport Section`s (ETS) two-dimensional, sequential gaussian puff transport and dispersion model for emergency response. The sequential puff scheme is described, and the dispersion equations are presented. The advantages of this model over the ETS`s PUFF/PLUME model are discussed. Options are calculating a two-dimensional wind field, interpolation procedures, and the wind field grid are described. The various grid systems for puff transport calculations and dose estimates are also described. A flow diagram for the modules comprising the 2DPUF code and a description of each module is presented.
Date: December 31, 1990
Creator: Addis, R. P. & O`Steen, B. L.
Object Type: Report
System: The UNT Digital Library
Hot nuclei -- Landau theory, thermal fluctuations and dissipation (open access)

Hot nuclei -- Landau theory, thermal fluctuations and dissipation

The basic ideas and theoretical methods used in the description of hot nuclei are reviewed. In particular, a macroscopic approach to shape transitions is discussed in the framework of the Landau theory in which the quadrupole shape degrees of freedom play the role of the order parameters. This theory describes the universal features of the nuclear shape evolution with temperature and spin. A unified description of fluctuations in all five quadrupole degrees of freedom is introduced and plays an important role in the calculation of physical observables. A macroscopic approach to the giant dipole resonance (GDR) in hot nuclei is developed. With all parameters fixed by the zero temperature nuclear properties, the theory predicts both the GDR cross-section and angular anisotropy of the {gamma}-rays in very good agreement with recent experiments. The intrinsic shape fluctuations are the main cause for the resonance broadening at higher temperatures, while the orientation fluctuations are responsible for the observed attenuation in the angular anisotropy. Dissipation at finite temperature is discussed in the framework of a Langevin-like equation describing the time-dependent shape fluctuations. Non-adiabatic effects may cause motional narrowing of the resonance.
Date: December 31, 1990
Creator: Alhassid, Y.
Object Type: Article
System: The UNT Digital Library
Phosphazene polymer containing composites and method for making phosphazene polymer containing composites (open access)

Phosphazene polymer containing composites and method for making phosphazene polymer containing composites

The object of the invention is to provide a composite material comprised of phosphazene polymer. A feature of phosphazene-containing composites is their superior stiffness, thermal stability, and hardness which is lacking in more typical composite constituents. An advantage of using phosphazene composites is a wider range of applications, including uses in harsh environments. Another object of the present invention provides a method for producing phosphazene-containing composite materials through a pultrusion process. In brief, these and other objects are achieved by a composite produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite. 2 figs., 6 tabs.
Date: December 31, 1990
Creator: Allen, C. A.; Grey, A. E.; McCaffrey, R. R.; Simpson, B. M. & Stone, M. L.
Object Type: Patent
System: The UNT Digital Library
Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site. Annual report, FY 1990 (open access)

Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site. Annual report, FY 1990

In 1985 the Southeastern Forest Experiment Station (SEFES) in cooperation with the Department of Energy, the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory (SREL) initiated a research/management program to restore a viable population of red-cockaded woodpeckers (RCW) to the Savannah River Site (SRS). We managed to stabilize the population in the first couple of years through an intensive flying squirrel removal project as well as augmentation of female RCW`s to the SRS population. We are now in the expansion phase of the project. In 1990 we have focused our efforts on: (1) developing a cavity excavation method and excavating cavities in suitable habitat; (2) flying squirrel control; (3) translocation of RCW`s; (4) monitoring clan composition and reproduction; (5) identification of old-growth stands with the potential of providing new nesting habitat to support population expansion; and (6) surveying lands near SRS where RCW`s were thought to exist. This report summarizes activities for FY 1990 and plans for FY 1991.
Date: December 31, 1990
Creator: Allen, D. H.
Object Type: Report
System: The UNT Digital Library
Trace multielement analysis of reactor moderator water: Simultaneous determination of copper, gold, silver, and mercury using differential pulse stripping voltammetry (open access)

Trace multielement analysis of reactor moderator water: Simultaneous determination of copper, gold, silver, and mercury using differential pulse stripping voltammetry

A rapid, inexpensive trace multi-element analysis of reactor moderator heavy water is described. Samples were analyzed for copper, silver, gold, and mercury at the low ppb level using Differential Pulse Stripping Voltametry (DPSV). These ions are kept below 25 ppb to avoid possible vessel corrosion. A high concentration of aluminum and iron in the samples prevented analysis by ICP spectroscopy. The DPSV method also avoided volatizing highly tritiated samples. Differential Pulse Stripping Voltametry is a commonly used electroanalytical technique for determining trace levels of metals in aqueous solutions. However, application of this method for routine analytical support in a plant laboratory environment was limited due to the method`s sensitivity to interferences. This paper describes a DPSV method which is rugged enough to be used for routine analytical support and addresses method interferences.
Date: December 31, 1990
Creator: Almon, A. C.
Object Type: Article
System: The UNT Digital Library
Electrochemical oxidation of organic waste (open access)

Electrochemical oxidation of organic waste

Both silver catalyzed and direct electrochemical oxidation of organic species are examined in analytical detail. This paper describes the mechanisms, reaction rates, products, intermediates, capabilities, limitations, and optimal reaction conditions of the electrochemical destruction of organic waste. A small bench-top electrocell being tested for the treatment of small quantities of laboratory waste is described. The 200-mL electrochemical cell used has a processing capacity of 50 mL per day, and can treat both radioactive and nonradioactive waste. In the silver catalyzed process, Ag(I) is electrochemically oxidized to Ag(II), which attacks organic species such as tributylphosphate (TBP), tetraphenylborate (TPB), and benzene. In direct electrochemical oxidation, the organic species are destroyed at the surface of the working electrode without the use of silver as an electron transfer agent. This paper focuses on the destruction of tributylphosphate (TBP), although several organic species have been destroyed using this process. The organic species are converted to carbon dioxide, water, and inorganic acids.
Date: December 31, 1990
Creator: Almon, A. C. & Buchanan, B. R.
Object Type: Article
System: The UNT Digital Library
Status and Future Prospects for Supersymmetry at the Tevatron (open access)

Status and Future Prospects for Supersymmetry at the Tevatron

We investigate the potential for discovery of super-symmetry during the next Tevatron Collider run in the light of new results fro LEP and CDF.
Date: December 31, 1990
Creator: Amos, N.; De, K.; White, A. & Yamin, P.
Object Type: Article
System: The UNT Digital Library
ORNL `90 (open access)

ORNL `90

This overview of research conducted at ORNL in 1991 presents information on the subjects of biology, physics, and the environment. Specific topics include gene mutations in kidney disease, technology assessments in thermonuclear fusion, submarine hunting technology, ozone-safe refrigerants, optical data storage via surface enhanced raman spectroscopy, and waste mitigating microbes. (GHH)
Date: December 31, 1990
Creator: Anderson, T.; Barnes, D. & Jefferson, J.
Object Type: Report
System: The UNT Digital Library
CeCu{sub 4}A{ell} and CeCu{sub 2}Zn{sub 2}A{ell}: Very heavy fermion systems in high magnetic fields (open access)

CeCu{sub 4}A{ell} and CeCu{sub 2}Zn{sub 2}A{ell}: Very heavy fermion systems in high magnetic fields

CeCu{sub 4}A{ell} and CeCu{sub 2}Zn{sub 2}A{ell} are heavy fermion systems with extremely enhanced C/T (specific heat divided by temperature) values of 2.3 and 1.8 J/K{sup 2} respectively as T {yields} 0 K. The field dependence of the low temperature specific heat is also extreme; 11 T reduces C of CeCu{sub 4}A{ell} by more than a factor of five, 12.5 T suppresses C of CeCu{sub 2}Zn{sub 2}A{ell} about seven times. Magnetic field caused changes of the specific heat of CeCu{sub 4}A{ell} are consistent with a single ion Kondo model. Magnetic correlations are at least partially responsible for the enhanced low temperature specific heat of CeCu{sub 2}Zn{sub 2}A{ell}.
Date: December 31, 1990
Creator: Andraka, B.; Kim, J. S.; Stewart, G. R. & Fisk, Z.
Object Type: Report
System: The UNT Digital Library
A miniature inexpensive, oxygen sensing element (open access)

A miniature inexpensive, oxygen sensing element

Current progress on the development of the oxygen sensor is reviewed. During this quarter the sensor seal and heating element was redesigned and prototypes were tested. A combustor experiment will be performed in the next one to two quarters. Related information on lean sensors is also reviewed. Additional testing was done on multilayer sensors pulled from storage. (SM)
Date: December 31, 1990
Creator: Arenz, R.W.
Object Type: Report
System: The UNT Digital Library
[Structure and electronic properties of defects at nonlattice matched III-V semiconductor interfaces]. Progress report, 1989--90 (open access)

[Structure and electronic properties of defects at nonlattice matched III-V semiconductor interfaces]. Progress report, 1989--90

Research focused on control of misfit dislocations in strained epitaxial layers of GaAs through prepatterning of the substrate. Patterning and etching trenches into GaAs substrates before epitaxial growth results in nonplanar wafer surface, which makes device fabrication more difficult. Selective ion damaging the substrate prior to growth was investigated. The question of whether the overlayer must or must not be discontinuous was addressed. The third research direction was to extend results from molecular beam epitaxially grown material to organometallic chemical vapor deposition. Effort was increased to study the patterning processes and the damage it introduces into the substrate. The research program was initiated after the discovery that 500-eV dry etching in GaAs damages the substrate much deeper than the ion range.
Date: December 31, 1990
Creator: Ast, D. G.
Object Type: Report
System: The UNT Digital Library
[Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms of organometallic complexes: Progress report] (open access)

[Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms of organometallic complexes: Progress report]

We have constructed an infrared stopped-flow spectrophotometer and initiated a study of the mechanisms of reactions that involve a change in the oxidation state of organometallic complexes. In this summary we highlight our results on reactions (1) that formally involve exchange of a charged species between two metal carbonyl anions, (2) that involve addition of an electron to, or removal of an electron from organometallic complexes that contain a metal-metal bond, and (3) between coordination complexes and metal carbonyl anions.
Date: December 31, 1990
Creator: Atwood, J.
Object Type: Report
System: The UNT Digital Library
Wedge assembly for electrical transformer component spacing (open access)

Wedge assembly for electrical transformer component spacing

This invention is comprised of a wedge assembly that is easily inserted between two surface to be supported thereby, and thereafter expanded to produce a selected spacing between those surfaces. This wedge assembly has two outer members that are substantially identical except that they are mirror images of each other. Oppositely directed faces of these of these outer members are substantially parallel for the purpose of contacting the surfaces to be separated. The other faces of these outer members that are directed toward each other are tapered so as to contact a center member having complementary tapers on both faces. A washer member is provided to contact a common end of the outer members, and a bolt member penetrates this washer and is threadably received in a receptor of the center member. As the bolt member is threaded into the center member, the center member is drawn further into the gap between the outer members and thereby separates these outer members to contact the surfaces to be separated. In the preferred embodiment, the contacting surfaces of the outer member and the center member are provided with guide elements. The wedge assembly is described for use in separating the secondary windings …
Date: December 31, 1990
Creator: Baggett, F. E. & Cage, W. F.
Object Type: Patent
System: The UNT Digital Library
Grain Boundaries. Progress Report, February 15, 1990--October 15, 1990 (open access)

Grain Boundaries. Progress Report, February 15, 1990--October 15, 1990

The following are reported: structural studies (dislocation structure of Ni/Ag interphase boundary, structural complexity in grain boundaries with covalent bonding, relation between microscopic properties of two semiconducting grain boundaries and their orientations, diffraction effects due to double positioning in (111) Au bicrystals, sensitivity of diffraction profiles to grain boundary segregation, solute segregation at grain boundaries in Au, 4-body interatomic potential for Si for defect calculations); boundary migration studies (molecular dynamics study of grain boundary migration without participation of grain boundary dislocations); study of short-circuit diffusion along grain boundaries and its dependence on boundary structure; and thin-film deposition/bonding apparatus for manufacturing high-purity bicrystals.
Date: December 31, 1990
Creator: Balluffi, R. W. & Bristowe, P. D.
Object Type: Report
System: The UNT Digital Library
Decomposition of sodium tetraphenylborate (open access)

Decomposition of sodium tetraphenylborate

The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate, NaTPB, has been investigated. The focus of the investigation is on the determination of components which influence NaTPB decomposition. Copper(II) ions, solution temperature, and solution pH (hydroxide ion concentration) have all been demonstrated to affect NaTPB stability. Their relationship with each other and the stability of NaTPB has been determined. Based upon this knowledge, a method for stabilizing NaTPB was determined. Decomposition of a NaTPB solution was delayed with the addition of sodium hydroxide. In additional work, the elimination of oxygen from the reaction environment did not prevent NaTPB decomposition in the presence of copper(II) ions but did, however, affect the course of decomposition.
Date: December 31, 1990
Creator: Barnes, M. J.
Object Type: Article
System: The UNT Digital Library
Scenario evolution: Interaction between event tree construction and numerical analyses (open access)

Scenario evolution: Interaction between event tree construction and numerical analyses

Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Event tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, the authors discuss the iterations used to develop numerical analyses for PACE-90 (Performance Assessment Calculational Exercises) using basaltic igneous activity and human-intrusion event trees.
Date: December 31, 1990
Creator: Barr, G. E.; Barnard, R. W.; Dockery, H. A.; Dunn, E. & MacIntyre, A. T.
Object Type: Article
System: The UNT Digital Library
Surface electronic structure of GaAs(110) studied by Auger photoelectron coincidence spectroscopy (open access)

Surface electronic structure of GaAs(110) studied by Auger photoelectron coincidence spectroscopy

We have used Auger photoelectron coincidence spectroscopy to study the M{sub 4,5}VV Auger spectra of GaAs(110). Using this technique, the Ga and As spectra can be separated and studied independently. The lineshape of the As-M{sub 4,5}VV measured in coincidence with the As 3d photoemission line differs significantly from the conventional Auger spectrum. We attribute this to the surface electronic properties of the system. In addition, we have found that the ss-component of the As spectrum is more intense than expected based on calculations using atomic matrix elements. The Ga-M{sub 4,5}VV spectrum, of which only the pp-component is observed, agrees well with that expected from an independent electron model. A first principles electronic structure calculation of a 5-layer GaAs(110) slab has been performed to aid in the interpretation of the Auger spectra.
Date: December 31, 1990
Creator: Bartynski, R. A.; Garrison, K.; Jensen, E.; Hulbert, S. L. & Weinert, M.
Object Type: Article
System: The UNT Digital Library
Improved thermal storage module for solar dynamic receivers (open access)

Improved thermal storage module for solar dynamic receivers

This invention relates to a thermal storage apparatus and more particularly to an apparatus for use in conjunction with solar dynamic energy storage systems. The invention is comprised of a thermal energy storage system comprising a germanium phase change material and a graphite container.
Date: December 31, 1990
Creator: Beatty, R. L. & Lauf, R. J.
Object Type: Patent
System: The UNT Digital Library
Ion exchange in the nuclear industry (open access)

Ion exchange in the nuclear industry

Ion exchange is used in nearly every part of the nuclear fuel cycle -- from the purification of uranium from its ore to the final recovery of uranium and transmutation products. Ion exchange also plays a valuable role in the management of nuclear wastes generated in the fuel cycle.
Date: December 31, 1990
Creator: Bibler, J. P.
Object Type: Article
System: The UNT Digital Library
Advanced radioactive waste-glass melters (open access)

Advanced radioactive waste-glass melters

During pilot scale operations of the Scale Glass Melter for the US Department of Energy a team of engineers and scientists was formed to assess the need for continued melter design development to support the Defense Waste Processing Facility (DWPF), and prioritize future efforts. Recently this has taken on new importance because of selection of the DWPF Melter design as the reference for the Hanford Waste Vitrification Project (HWVP), and increased interest at the West Valley Demonstration Project on melter life and replacement. Results of the study are summarized, and goals produced by the study are compared to the results of current programs at the Savannah River Laboratory (SRL).
Date: December 31, 1990
Creator: Bickford, D. F.
Object Type: Article
System: The UNT Digital Library
Control of high-level radioactive waste-glass melters. Part 4, Preliminary analysis of DWPF process laboratory capabilities (open access)

Control of high-level radioactive waste-glass melters. Part 4, Preliminary analysis of DWPF process laboratory capabilities

The Defense Waste Processing Facility (DWPF) will immobilize Savannah River Site High Level Waste as a durable borosilicate glass for permanent disposal in a repository. The DWPF will be controlled based on glass composition. The following discussion is a preliminary analysis of the capability of the laboratory methods that can be used to control the glass composition, and the relationships between glass durability and glass properties important to glass melting. The glass durability and processing properties will be controlled by controlling the chemical composition of the glass. The glass composition will be controlled by control of the melter feed transferred from the Slurry Mix Evaporator (SME) to the Melter Feed Tank (MFT). During cold runs, tests will be conducted to demonstrate the chemical equivalence of glass sampled from the pour stream and glass removed from cooled canisters. In similar tests, the compositions of glass produced from slurries sampled from the SME and MFT will be compared to final product glass to determine the statistical relationships between melter feed and glass product. The total error is the combination of those associated with homogeneity in the SME or MFT, sampling, preparation of samples for analysis, instrument calibration, analysis, and the composition/property model. …
Date: December 31, 1990
Creator: Bickford, D. F. & Coleman, C. J.
Object Type: Article
System: The UNT Digital Library
Control of high level radioactive waste-glass melters. Part 6, Noble metal catalyzed formic acid decomposition, and formic acid/denitration (open access)

Control of high level radioactive waste-glass melters. Part 6, Noble metal catalyzed formic acid decomposition, and formic acid/denitration

A necessary step in Defense Waste Processing Facility (DWPF) melter feed preparation for the immobilization of High Level Radioactive Waste (HLW) is reduction of Hg(II) to Hg(0), permitting steam stripping of the Hg. Denitrition and associated NOx evolution is a secondary effect of the use of formic acid as the mercury-reducing agent. Under certain conditions the presence of transition or noble metals can result in significant formic acid decomposition, with associated CO{sub 2} and H{sub 2} evolution. These processes can result in varying redox properties of melter feed, and varying sequential gaseous evolution of oxidants and hydrogen. Electrochemical methods for monitoring the competing processes are discussed. Laboratory scale techniques have been developed for simulating the large-scale reactions, investigating the relative effectiveness of the catalysts, and the effectiveness of catalytic poisons. The reversible nitrite poisoning of formic acid catalysts is discussed.
Date: December 31, 1990
Creator: Bickford, D. F.; Coleman, C. J.; Hsu, C. L. W. & Eibling, R. E.
Object Type: Article
System: The UNT Digital Library
A Stripline Fast Faraday Cup for measuring GHz structure of ion beams (open access)

A Stripline Fast Faraday Cup for measuring GHz structure of ion beams

The Stripline Fast Faraday Cup is a device which is used to quantitatively and qualitatively measure gigahertz time structure characteristics of ion beams with energies up to at least 30 Mev per nucleon. A stripline geometry is employed in conjunction with an electrostatic screen and a Faraday cup to provide for analysis of the structural characteristics of an ion beam. The stripline geometry allows for a large reduction in the size of the instrument while the electrostatic screen permits measurements of the properties associated with low speed ion beams.
Date: December 31, 1990
Creator: Bogaty, J. M.
Object Type: Patent
System: The UNT Digital Library