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Separation of Metals by Supported Liquid Membranes
A supported liquid membrane system for the separation of a preselected chemical species within a feedstream, preferably an aqueous feedstream, includes a feed compartment containing a feed solution having at least one preselected chemical species therein, a stripping compartment containing a stripping solution therein, and a microporous polybenzimidazole membrane situated between the compartments, the microporous polybenzimidazole membrane containing an extractant mixture selective for the preselected chemical species within the membrane pores is disclosed along with a method of separating preselected chemical species from a feedstream with such a system, and a supported liquid membrane for use in such a system.
Date:
December 31, 1990
Creator:
Takigawa, Doreen Y.
Object Type:
Patent
System:
The UNT Digital Library
Silicon nitride reinforced with molybdenum disilicide
Compositions of matter comprised of silicon nitride and molybdenum disilicide and methods of making the compositions, where the molybdenum disilicide is present in amounts ranging from about 5 to about 50 vol%.
Date:
December 31, 1990
Creator:
Petrovic, John J. & Honnell, Richard E.
Object Type:
Patent
System:
The UNT Digital Library
The single-chip FASTBUS Slave Interface
A single-chip implementation of the general-purpose FASTBUS Slave Interface (FSI) has been developed in ECL gate-array technology. The FSI will occupy only 1.6% of the available circuit board space while providing a complete 32-bit interface to the FASTBUS. All mandatory slave-interface requirements of IEEE 960 are supported, in addition to several non-mandatory requirements and the optional, extended MS code features. Geographic, logical, and broadcast addressing are implemented using on-chip registers. An optional multiple-module addressing technique is included that allows participating modules residing on a common crate or cable segment to respond as if individually addressed in sequence. The user interface provided by the FSI allows control of slave status-response and connection timing for both address and data cycles. The BIT1 ECL array technology used for the FSI allows direct connections to the FASTBUS, eliminating the need for external driver/receiver buffers.
Date:
December 31, 1990
Creator:
Nelson, R. O.; Machen, D. R. & Downing, R. W.
Object Type:
Article
System:
The UNT Digital Library
SiO2 Membranes for H2 Separation in Coal Gas Processing. Quarterly Progress Report, March 1, 1990--May 31, 1990
The project objectives are (1) to synthesize permselective ceramic membranes by chemical vapor deposition of SiO{sub 2} and other oxides within the walls of porous support tubes, (2) measure membrane permeability and thermal stability to various gases at 200--700{degrees}C and (3) develop a mathematical model for the chemical vapor deposition of the permselective oxide within the porous support tube.
Date:
December 31, 1990
Creator:
Gavalas, G. R.
Object Type:
Report
System:
The UNT Digital Library
Siphon breaker design requirements. Progress report
This project was intended to provide experimental data on siphon flow effects. The system was to be modeled with the RELAP code and the predicted and measured performances compared. The experimental system consists of a 500-gallon upper tank, a 4-inch downcomer pipe, a lower catch tank, a return pump and associated piping. The downcomer pipe is made of 4-inch clear acrylic pipe so the flow patterns could be observed and video taped during the test runs.
Date:
December 31, 1990
Creator:
Neill, D. T. & Stephens, A. G.
Object Type:
Report
System:
The UNT Digital Library
Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst, January 1, 1990--March 30, 1990
Experiments to study cobalt-catalyzed reactions of light 1-alkenes added to synthesis gas feed have been performed. Data have been collected at 220{degrees}C, 0.45 to 1.48 MPa and a synthesis gas flow rate between 0.015 and 0.030 Nl/(gcatmin) with H{sub 2}/CO of 1.45 to 2.25. C{sub 2}H{sub 4}, C{sub 3}H{sub 6}, and C{sub 4}H{sub 8} were added to the synthesis gas feed in concentrations ranging from 0.5 to 1.2 mole% of total feed. For each material balance in which 1-alkenes were added, a material balance was performed at similar process conditions without 1-alkenes added. This use of ``base case`` process conditions should make data analysis and interpretation easier. Material balances without 1-alkenes were also repeated to allow verification of catalyst selectivity stability. A total of 49 balances were performed during a single run which lasted over 2500 hours-on-stream. The hydrocarbon data have not yet been completed analyzed.
Date:
December 31, 1990
Creator:
Yates, I. C. & Satterfield, C. N.
Object Type:
Report
System:
The UNT Digital Library
Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, April 1, 1990--June 30, 1990
Experiments on cobalt-catalyzed reactions of light 1-alkenes added to synthesis gas were performed. Data have been collected at 220C, 0.45 to 1.48 MPa and a synthesis gas flow rate between 0.015 and 0.030 Nl/(gcat{center_dot}min) with H{sub 2}/CO of 1.45 to 2.25. Ethylene, propene, and butene were added to synthesis gas feed from 0.5 to 1.2 mole% of total feed. For each material balance in which 1-alkenes were added, a material balance was performed at similar process conditions without 1-alkenes added, as ``base case``. Material balances without added 1-alkenes were also repeated to verify of catalyst selectivity stability. 49 material balances were performed during a single run lasting over 2,500 hours-on-stream. The hydrocarbon data have been completely analyzed; data correlations are still being made. Since C{sub 3}/C{sub 1} ratios by ethene addition, C{sub 4}/C{sub 1} ratios by propene addition, and C{sub 5}/C{sub 1} ratios by 1-butene addition, it appears that 1-alkenes may incorporate into growing chains on the surface of the catalyst. Further evidence for incorporation can be seen by comparing selectivity to n-alcohol one carbon number higher than added 1-alkene. Yield of this n-alcohol increases when alkenes are present. Sensitivity of hydrocarbon distribution to process variables seems to be greater …
Date:
December 31, 1990
Creator:
Yates, I. C. & Satterfield, C. N.
Object Type:
Report
System:
The UNT Digital Library
Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, July 1, 1990--September 30, 1990
A Co/MgO/SiO{sub 2} Fischer-Tropsch catalyst was operated simultaneously with a Cu/ZnO/Al{sub 2}O{sub 3} water-gas-shift catalyst in a slurry reactor for over 400 hours. The process conditions were held constant at a temperature of 240{degrees}C, a pressure of 0.79 MPa, and a 1.1 H{sub 2}/CO feed of 0.065 Nl/min-g.cat. The Fischer-Tropsch activity remained constant at the level predicted by the operation of the Co/MgO/SiO{sub 2} catalyst alone. The water-gas-shift reaction was near equilibrium. The hydrocarbon product distribution of the combined catalyst system was stable and matched that of the CO/MgO/SiO{sub 2} operating alone under similar conditions. The combined catalyst system exhibited a high selectivity to n-alkanes. Neither catalysts`s operation appeared to have a detrimental effect on that of the other, showing promise for future option.
Date:
December 31, 1990
Creator:
Chanenchuk, C. A.; Yates, I. C. & Satterfield, C. N.
Object Type:
Report
System:
The UNT Digital Library
Solar neutrino physics in the nineties
The decade of the 1990`s should prove to be landmark period for the study of solar neutrino physics. Current observations show 2--3 times fewer neutrinos coming from the sun than are theoretically expected. As we enter the decade, new experiments are poised to attempt and discover whether this deficit is a problem with our understanding of how the sun works, is a hint of new neutrino properties beyond those predicted by the standard model of particle physics, or perhaps a combination of both. This paper will briefly review the current status of the field and point out how future measurements should help solve this interesting puzzle. 11 refs., 3 figs., 1 tab.
Date:
December 31, 1990
Creator:
Wilkerson, J. F.
Object Type:
Article
System:
The UNT Digital Library
Solid-state NMR imaging system
An accessory for use with a solid-state NMR spectrometer includes a special imaging probe with linear, high-field strength gradient fields and high-power broadband RF coils using a back projection method for data acquisition and image reconstruction, and a real-time pulse programmer adaptable for use by a conventional computer for complex high speed pulse sequences.
Date:
December 31, 1990
Creator:
Gopalsami, N.; Dieckman, S. L. & Ellingson, W. A.
Object Type:
Patent
System:
The UNT Digital Library
Spectroscopic diagnostics of high temperature plasmas. [Annual report]
A three-year research program for the development of novel XUV spectroscopic diagnostics for magnetically confined fusion plasmas is proposed. The new diagnostic system will use layered synthetic microstructures (LSM) coated, flat and curved surfaces as dispersive elements in spectrometers and narrow band XUV filter arrays. In the framework of the proposed program we will develop impurity monitors for poloidal and toroidal resolved measurements on PBX-M and Alcator C-Mod, imaging XUV spectrometers for electron density and temperature fluctuation measurements in the hot plasma core in TEXT or other similar tokamaks and plasma imaging devices in soft x-ray light for impurity behavior studies during RF heating on Phaedrus T and carbon pellet ablation in Alcator C-Mod. Recent results related to use of multilayer in XUV plasma spectroscopy are presented. We also discuss the latest results reviewed to q{sub o} and local poloidal field measurements using Zeeman polarimetry.
Date:
December 31, 1990
Creator:
Moos, W.
Object Type:
Report
System:
The UNT Digital Library
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
A strategy for the derivation and use of sorption coefficients in performance assessment calculations for the Yucca Mountain site
The chemical interactions of dissolved radionuclides with mineral surfaces along flowpaths from the proposed repository to the accessible environment around Yucca Mountain constitute one of the potential barriers to radionuclide migration at the site. Our limited understanding of these interactions suggests their details will be complex and will involve control by numerous chemical and physical parameters. It appears unlikely that we will understand all the details of these reactions or obtain all the site data required to evaluate each of them in the time available for site characterization. Yet, performance assessment calculations will require some form of coupling of chemical interaction models will hydrologic flow models for the site. Clearly, strategies will be needed to bound the problem without compromising the reliability of the performance assessment calculations required for site suitability analysis. The main purpose of this paper is to describe such a strategy. 39 refs., 7 figs., 5 tabs.
Date:
December 31, 1990
Creator:
Meijer, A.
Object Type:
Article
System:
The UNT Digital Library
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
[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
Student Science Enrichment Training Program
Funds are requested for the science enrichment training program (emphasis on chemistry and computer science), which will be held at Claflin College during the 1990 and 1991 summers, concomitant with summer school. The thirty participants will include high school students and some college freshmen; the students will come from rural South Carolina schools with limited science and computer facilities. Focus will be on high ability minority students.
Date:
December 31, 1990
Creator:
Sandhu, S. S.
Object Type:
Report
System:
The UNT Digital Library
Studies of Coupled Chemical and Catalytic Coal Conversion Methods. Eleventh Quarterly Report, April--June 1990
The objective of our work is coal liquefaction under relatively mild conditions. Our attempts were to depolymerize the coal macromolecule to smaller fragments which could be more easily solubilized in conventional organic solvents. During the last few months we have been working on nonreductive C-alkylation procedures. The effectiveness of the newly introduced alkyl groups for the disruption of intemolecular hydrogen bonds and pi-pi interactions between the aromatic sheets in the coal mdcromolecule had been recognized. During the present quarter, a new approach for the depolymerization of the coal macromolecule was tried. This was aimed towards carbon-carbon bond cleavage in the presence of strong bases. Such bond cleavage reactions are well known with the alkali metals. Electron transfer reactions take place from the metals to the aromatic nuclei resulting in the formation of anion radicals (or dianions) which subsequently undergo carbon-carbon bond cleavage. In our work, instead of using the alkali metals, we have used bases to cleave the carbon-carbon bonds by base catalyzed hydrocarbon elimination reactions.Such anionic fragmentation reactions involving strong bases are not very well established. The only discrete evidence of carbon-carbon bond cleavage with bases were obtained from some earlier works of Grovenstein.
Date:
December 31, 1990
Creator:
Stock, L. M.
Object Type:
Report
System:
The UNT Digital Library
Studies of Coupled Chemical and Catalytic Coal Conversion Methods. Tenth Quarterly Report, January--March 1990
This report concerns our research on base-catalyzed coal solubilization and a new approach for hydrogen addition. The work on base-catalyzed, chemical solubilization is continuing. this report is focused on the hydrogenation research. Specifically it deals with the use of arene chromium carbonyl complexes as reagents for the addition of dideuterium to coal molecules. In one phase of the work, he has established that the aromatic hydrocarbons in a representative coal liquid can be converted in very good yield to arene chromium carbonyl compounds. In a second phase of the work directly related to our objective of improved methods for catalytic hydrogenation, he has established that the aromatic constituents of the same coal liquid add dideuterium in the presence of added napththalene chromium carbonyl.
Date:
December 31, 1990
Creator:
Stock, L. M.
Object Type:
Report
System:
The UNT Digital Library
Studies of Coupled Chemical and Catalytic Coal Conversion Methods. Twelfth Quarterly Report, July--September 1990
During the previous quarter, a new approach for the deploymerization of the coal macromolecule was tried. This was aimed towards carbon-carbon bond cleavage in presence of strong bases. Such bond cleavage reactions are well known with the alkali metals. Electron transfer reactions take place from the metals to the aromatic nuclei resulting in the formation ofanion-radicals (or dianions) which subsequently undergo carbon-carbon bond cleavage. In our work instead of using the alkali metals, we have used strong bases to cleave the carbon-carbon bonds in hydrocarbons, and have suggested that hydrocarbon elimination reactions occur. Such anionic fragmentation reactions involving strong bases are not very well established. However, we have obtained circumstantial evidence that such bond cleavage reactions do take place in some coal systems. For example, when the high rank Lower Kittaming coal, PSOC 1197, was treated with Lochmann`s base (equimolar mixture of n-butyllithiun and potassium tert-butoxide) in refluxing heptane and quenched with ammonium chloride and reethanol, the pyridine solubility of the product increased from 5% (raw coal) to 39%. A similar increase in solubility due to base treatment was also observed in a separate study for another high rank coal, Pocahontas No. 3 from the Argonne National Laboratory Premium Sample …
Date:
December 31, 1990
Creator:
Stock, L. M.
Object Type:
Report
System:
The UNT Digital Library
Studies of nuclei far from stability in the A=80 mass region. Final report
A three-stage thin-film detector for the identification of heavy ion fragments was investigated in beam at HHIRF. An experiment on Eu-152 for the purposes of calibrating a four-crystal Germanium polarimeter was performed. The instrument was then used in an experiment to establish polarities for the low-lying transitions in {sup 82}Sr. The spectral fitting code ROBFIT was applied to the data analysis and shown to perform well on the extraction of weak peaks in high background situations.
Date:
December 31, 1990
Creator:
Coldwell, R. L.; Dunnam, F. E.; Muga, M. L. & Rester, A. C.
Object Type:
Report
System:
The UNT Digital Library
[Studies of the repair of radiation-induced genetic damage in Drosophila]. Annual progress report, June 1, 1989--September 1, 1990
The most exciting discovery made over the past year derives from an analysis of the interaction between DNA repair and P-element transposition. A powerful new system was developed for analyzing the repair of DNA double-strand breaks. A screen was completed of mutagenized autosomes obtained from two San Francisco laboratories with the recovery of several mutants that will provide the foundation for future efforts to clone repair related genes. At the same time, strong progress has been made in the cloning and characterization of the repair-related genes mei-41 and mus209. Finally, the efforts to clone the mei-9 gene have uncovered the existence of a unsuspected feature of the system used for transposon-tagging in Drosophila. This new knowledge will aid future cloning efforts as well as those of others in the field.
Date:
December 31, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Study of High {Tc} Superconducting Thin Films Grown by MOCVD. Final Report, July 1, 1986--April 30, 1990
Work is described briefly, which was carried out on development of techniques to grow metal-semiconductor superlattices (artificially layered materials) and on the copper oxide based susperconductors (naturally layered materials). The current growth technique utilized is metalorganic chemical vapor deposition (MOCVD). CdTe, PbTe, La, LaTe, and Bi{sub 2}Te{sub 3} were deposited, mostly on GaAs. Several YBa{sub 2}Cu{sub 3}O{sub 7} compounds were obtained with possible superconductivity at temperatures up to 550 K (1 part in 10{sup 4}). YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} and Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub y} thin films were deposited by MOCVD on common substrates such as glass.
Date:
December 31, 1990
Creator:
Erbil, A.
Object Type:
Report
System:
The UNT Digital Library
Sulphur Springs News-Telegram (Sulphur Springs, Tex.), Vol. 112, No. 308, Ed. 1 Monday, December 31, 1990
Daily newspaper from Sulphur Springs, Texas that includes local, state, and national news along with advertising.
Date:
December 31, 1990
Creator:
Keys, Clarke
Object Type:
Newspaper
System:
The Portal to Texas History
{sup 31}P NMR analysis of coal moieties bearing -OH, -NH and -SH functions. Quarterly report, January 1, 1990--March 31, 1990
Research continues on the structural analysis of coal. In attempting to derivatize solid coal for solid state NMR analysis, we observed {sup 31}P NMR shifts in an unexpected region; these interesting leads will be pursued on the chance that the reaction we have evoked holds potential for yielding new coal characterizational information. Two very gratifying results have emerged from our {sup 119}Sn chemical shift measurements of a limited set of model compounds in pyridine. Firstly, the chemical shift dispersion is very large for phenols, alcohols and amides. Secondly, unlike {sup 119}Sn chemical shifts in hexane or chloroform, the shifts in pyridine are concentration independent.
Date:
December 31, 1990
Creator:
Verkade, J. G.
Object Type:
Report
System:
The UNT Digital Library