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459
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203
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112
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106
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67
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15,323 Matching Results
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Beat wave current drive experiment on the Davis Diverted Tokamak (DDT). Final report
The beatwave current drive experiment is summarized. The first phase of the experiment was the construction of the microwave sources and the diagnostics needed to demonstrate the beat wave effects, i.e. the measurement of the electrostatic plasma wave produced by the beating of two high intensity electromagnetic waves. In order to keep the cost of the experiments to a minimum, a low density filament plasma source (10{sup 8}) to (10{sup 10} particles cm{sup {minus}3}) was employed and the magnetic field in the toroidal plasma was produced by a dc power supply.
Date:
December 31, 1993
Creator:
Hwang, D. Q.; Horton, R. D. & Rogers, J. H.
Object Type:
Report
System:
The UNT Digital Library
The behavior-genetics debate in the United States
This paper, submitted to the Third Bioethics Seminar in Fukai, Japan, presents information on program activities and discusses primary topics concerning genetic factors in behavior. Proponents and critics views on genetic explanations of antisocial behavior are discussed.
Date:
December 31, 1993
Creator:
Yesley, M. S.
Object Type:
Article
System:
The UNT Digital Library
Behavior of sulfur and chlorine in coal during combustion and boiler corrosion. Final technical report, 1 September, 1992--31 August, 1993
The goals of this project are to investigate the behavior of sulfur and chlorine during pyrolysis and combustion of Illinois coals, the chemistry and mineralogy of boiler deposits, the effects of combustion gases on boiler materials, and remedial measures to reduce the sulfur and chlorine compounds in combustion gases. Replicate determinations of chlorine and sulfur evolution during coal pyrolysis-gas combustion were conducted using a pyrolysis apparatus in conjunction with a quadrupole gas analyzer. HCl is the only gaseous chlorine species measured in combustion gases. Pyrolysis of coal IBC-109 spiked with NaCl solution shows a strong peak of HCl evolution above 700C. The absence of this peak during pyrolysis of Illinois coal indicates that little chlorine in Illinois coal occurs in the NaCl form. Evolution of sulfur during coal pyrolysis was studied; the sulfur evolution profile may be explained by the sulfur forms in coal. To determine the fate of sulfur and chlorine during combustion, a set of six samples of boiler deposits from superheater and reheater tubes of an Illinois power plant was investigated. Scanning electron microscopy shows microscopic calcium sulfate droplets on cenospheres. Superheater deposits are high in mullite, hematite, and cristobalite, whereas a reheater deposit is enriched in …
Date:
December 31, 1993
Creator:
Chou, C. L.; Hackley, K. C.; Cao, J.; Moore, D. M.; Xu, J.; Ruch, R. R. et al.
Object Type:
Report
System:
The UNT Digital Library
Bench-scale co-processing. Technical progress report No. 22, October 1, 1993--December 31, 1993
The major objective of this contract is to establish a database for the optimization of the co-processing concept by improving the effectiveness of the co-processing catalyst system. Two major mechanisms for improving the catalyst system are to be investigated: employment of more effective catalysts and utilization of improved catalytic environments. This report covers the period of October 1, 1993 to December 31, 1993. During this period work on Subtask 3.2.2, Improvement in Catalytic Environment, was carried out and the bench-scale co-processing pilot plant was operated in the co-current mode with product recycle and increased catalyst concentration. The project objective was to achieve 90+ % conversion of the 510{degrees}C+ non-distillables at 2800 psig. Currently work is on-going in a stirred autoclave at the same catalyst concentration as that in the runs reported here, and the results of these autoclave runs will be summarized in Technical Progress Report No. 23.
Date:
December 31, 1993
Creator:
Duttlinger, M. L. M.; Commisaris, S. E.; Davis, L. A.; Yurek, R. W.; Gatsis, J. G.; Roemisch, R. et al.
Object Type:
Report
System:
The UNT Digital Library
Bench-scale co-processing. Technical progress reports No. 17--20, July 1, 1992--June 30, 1993
UOP`s second co-processing contract, DE-AC22-87PC79818, began in April 1988. The major objective of this contract is to establish a database for the optimization of the co-processing concept by improving the effectiveness of the co-processing catalyst system. Two major mechanisms for improving the catalyst system are to be investigated: employment of more effective catalysts and utilization of improved catalytic environments. These two mechanisms are defined in the contract Statement of Work under Task 3.2 as Subtask 3.2.1 and 3.2.2, respectively. This report covers a span of four quarters, starting from July 1, 1992 to June 30, 1993. During this period the project was in a hold. As explained below, a request was made to add more funds to the contract to investigate catalytic environment improvements. Most of the time during this four quarters was spent in preparation of the proposal, review of the proposal by PETC, and getting additional funding approved for the contract. No experimental work was carried out on any of the tasks of the contract during these four quarters. Prior to the period covered by this report, UOP had successfully completed Subtask 3.2.1 and identified a molybdenum-based catalyst that is highly active and effective in achieving improved co-processing …
Date:
December 31, 1993
Creator:
Gala, H. B.
Object Type:
Report
System:
The UNT Digital Library
Bench-scale demonstration of biological production of ethanol from coal synthesis gas. Quarterly report: July 1, 1993--September 30, 1993
The purpose of this report is to present results from culture isolation and selection studies, bench-scale fermentation experiments, and ethanol recovery experiments. Several promising isolates have been obtained in addition to Clostridium ljungdahlii, strain PETC, and are being used in batch and continuous culture comparison studies. C. ljungdahlii is being utilized in two-stage bench-scale reactor studies, aimed at producing ethanol in high concentrations from a stable culture system. Finally, solvent comparison studies have been performed for the economical recovery of ethanol from the fermentation broth.
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Bench-scale demonstration of biological production of ethanol from coal synthesis gas. Quarterly report, October 1, 1993--December 31, 1993
This project describes a new approach to coal liquefaction, the biological conversion of coal synthesis gas into a liquid fuel, ethanol. A new bacterium, Clostridium Ijungdahlii, strain PETC, has been discovered and developed for this conversion, which also produces acetate as a by-product. Based upon the results of an exhaustive literature search and experimental data collected in the ERI laboratories, secondary and/or branched alcohols have been selected for ethanol extraction from the fermentation broth. 2,6 Methyl 4-heptanol has a measured distribution coefficient of 0.44 and a separation factor of 47. Methods to improve the results from extraction by removing water prior to distillation are under consideration. Several runs were performed in the two-stage CSTR system with Clostridium Ijungdahlii, strain PETC, with and without cell recycle between stages. Reduced gas flow rate, trypticase limitation and ammonia limitation as methods of maximizing ethanol production were the focus of the studies. With ammonia limitation, the ethanol:acetate product ratio reached 4.0.
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Bench-scale demonstration of hot-gas desulfurization technology. Quarterly technical progress report, July 1, 1993--September 30, 1993
The US Department of Energy (DOE), Morgantown Energy Technology Center (METC), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal gas) streams of integrated gasification combined-cycle (IGCC) power systems. The programs focus on hot-gas particulate removal and desulfurization technologies that match or nearly match the temperatures and pressures of the gasifier, cleanup system, and power generator. The purpose is to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents which can reduce the sulfur in coal gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn{sub 2}TiO{sub 4} or ZnTiO{sub 3}), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO{sub 2}), is currently the leading sorbent. The sulfidation/regeneration cycle can be carried out in fixed-bed, moving-bed, or fluidized-bed reactor configuration, and all three types of reactors are slated for demonstration in the DOE Clean Coal Technology program. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the …
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Benchmark calculations for a heavy water research reactor using the WIMS-D4M code and a ENDF/B-V based library
The results of unit-cell and global diffusion and transport calculations performed for the Georgia Tech heavy water research reactor using the WIMS-D4m code and a new ENDF/B-V based library are presented in this paper. Key cross sections, eigenvalues, neutron fluxes and peak power densities obtained from global diffusion calculations are compared.
Date:
December 31, 1993
Creator:
Mo, S. C.
Object Type:
Article
System:
The UNT Digital Library
Benchmark calculations for some Los Alamos oralloy critical experiments
In late 1976, LANL personnel performed are accurate measurement to determine the critical mass of a sphere of highly enriched uranium (oralloy) when reflected by water. This experiment has been used previously to benchmark the MCNP and KENO Monte Carlo codes. However, these benchmark calculations were performed for idealizations of the experiment and involved significant approximations. In contrast, the analysis reported herein is based on a detailed representation of the actual experiment and a set of recently published isotopic specifications for the sphere. Differences between the results from this study and those from the earlier benchmark calculations are related to specific aspects of those calculations.
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Binary-binary collisions involving main-sequence stars, white dwarfs and neutron stars in globular clusters
We consider collisions between dynamically-evolved primordial binaries consisting of main-sequence stars, white dwarfs and neutron stars in globular clusters. In our four-body binary-binary scattering experiments, we allow stars to ``stick`` if they pass close enough to each other, which leads to the formation of a wide variety of exotic objects. Most of these objects have binary companions. Also, relatively clean exchange interactions can produce binaries containing neutron stars that eventually receive material from their companions. Such systems will be observable as X-ray binaries.
Date:
December 31, 1993
Creator:
Leonard, P. J. T. & Davies, M. B.
Object Type:
Article
System:
The UNT Digital Library
Biodesulfurization of mild gasification liquid products. Final technical report, 1 September, 1992--31 August, 1993
The mild gasification of coal, as being developed at IGT and elsewhere, is a promising new technology that can convert coal to multiple products: gas, solid, and liquids. Mild gasification liquids can be used as feedstock to make transportation fuels and chemicals. However, the sulfur content and aromaticity of mild gasification liquids limits their usefulness and biodesulfurization can potentially decrease both sulfur content and aromaticity. The objective of this project is to investigate and feasibility of using biodesulfurization to upgrade the quality of mild gasification liquids. During this project, it was shown that the middle distillate (360--440 F) fraction of liquids derived from the mild gasification of coal, and unfractionated liquids can be biodesulfurized. Moreover, it was demonstrated that lysed cell preparations and freeze-dried cells can be used to biodesulfurize mild coal gasification liquids. The importance of the finding that freeze-dried biocatalysts can be used to biodesulfurize mild coal gasification liquids is that freeze-dried cells can be produced at one location, stored indefinitely, and then shipped (at reduced weight, volume, and cost) to another location for coal biodesulfurization. Moreover, freeze-dried biocatalysts can be added directly to mild coal gasification liquids with only minimal additions of water so that reactor volumes …
Date:
December 31, 1993
Creator:
Kilbane, J. J., II
Object Type:
Report
System:
The UNT Digital Library
Biological upgrading of coal liquids. Quarterly report, July 1, 1993--September 30, 1993
The presence of heteroatom and aromatic compounds in liquids obtained from coal liquefaction processes requires expensive hydrogenation treatment to derive an acceptable liquid fuel. This project will develop a simple biological process for removing N, O and S and reducing the aromaticity of coal liquids. Microorganisms, employing biocatalysts, are known to degrade aromatic heteroatom compounds in nature to NH{sub 3}, SO{sub 4}{sup =} and CO{sub 2}. Preliminary experiments in the ERI laboratories to determine the feasibility of biological removal of N, O and S from coal and shale oil liquids have shown up to 20 percent nitrogen removal, 40 percent sulfur removal and 100 percent oxygen removal in a simple one stage incubation. A biological process for upgrading of coal liquids would offer significant advantages, such as operation at ordinary temperature and pressure with better energy efficiency. Of greater importance is the fact that microorganisms do not require an external supply of hydrogen for heteroatom removal, obtaining the required hydrogen from water. Furthermore, the biocatalysts are continuously regenerated by growth on the heteroatom compounds. Ring structures are degraded as the heteroatoms are removed. The heteroatoms are in an innocuous form, such as NH{sub 3}, S0{sub 4}{sup =}, C0{sub 2} and …
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Biological upgrading of coal liquids. Quarterly report, October 1, 1993--December 31, 1993
A large number of bacterial enrichments are being developed for their ability to utilize nitrogen and sulfur in coal liquids and the model compound naphtha. These bacteria include the original aerobic bacteria isolated from natural sources which utilize heteroatom compounds in the presence of rich media, aerobic nitrogen-utilizing bacteria and denitrifying bacteria. Experiments utilizing these bacteria are presented below. Stirred tank reactor studies utilizing these cultures are in progress, although results from these experiments are not presented at this time.
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Biosurfactants and increased bioavailability of sorbed organic contaminants: Measurements using a biosensor
Bioremediation of sites contaminated with hydrophobic materials that sorb onto the soil matrix is very difficult due to reduced microbial (bio)availability. Following biosurfactant addition, we have measured an increase in contaminant bioavailability by using a lux biosensor. Direct microbial bioavailability was determined by using a genetically engineered microbial bioreporter strain of Pseudomonas putida. This strain was engineered so the lux genes, which code for light production, are transcriptionally fused with genes that code for contaminant degradation and are thus induced in the presence of specific compounds. By using a bioreporter we can quantify the actual microbial bioavailability of the contaminants and compare it to concentrations measured by other analytical methods (e.g. gas chromatograph). It is possible that these values are not equal to each other. Thus, bioremediation rates may not be accurately predicted if bioavailability is not considered.
Date:
December 31, 1993
Creator:
Strong-Gunderson, J. M.; Palumbo, A. V.; Applegate, B. & Saylor, G. S.
Object Type:
Article
System:
The UNT Digital Library
BNL possibilities
The Brookhaven National Laboratory AGS facility provides the intense kaon and pion beams necessary for detailed studies of the hyperon-nucleon interaction. A description of available beams is provided along with a summary of the current and future physics program.
Date:
December 31, 1993
Creator:
Pile, P. H.
Object Type:
Article
System:
The UNT Digital Library
Brazing of the Tore Supra actively cooled Phase III Limiter
The head of the water-cooled Tore Supra Phase 3 Limiter is a bank of 14 round OFHC copper tubes, curved to fit the plasma radius, onto which several hundred pyrolytic graphite (PG) tiles and a lesser number of carbon fiber composite tiles are brazed. The small allowable tolerances for fitting the tiles to the tubes and mating of compound curvatures made the brazing and fabrication extremely challenging. The paper describes the fabrication process with emphasis on the procedure for brazing. In the fixturing for vacuum furnace brazing, the tiles were each independently clamped to the tube with an elaborate set of window frame clamps. Braze quality was evaluated with transient heating tests. Some rebrazing was necessary.
Date:
December 31, 1993
Creator:
Nygren, R. E.; Walker, C. A.; Lutz, T. J.; Hosking, F. M. & McGrath, R. T.
Object Type:
Report
System:
The UNT Digital Library
Brief summary of accomplishments since our DOE-sponsored radon project commenced. Technical progress report, [January 1, 1993--December 31, 1993]
We have focused on determining the thermomechanical and kinetic properties involving their interactions with common atmospheric molecules and indoor pollutants. In view of the fact that a large fraction of the progeny ions are thought to be in the singly charged state, we have directed attention to the evolving chemistry of these species. Emphasis has been placed on acquiring fundamental thermochemical information which will provide a basis for modeling studies and that are requisite in obtaining a more complete picture of growth, attachment to aerosols, and ultimately transport to the bioreceptor.
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Brittle composites modeling: Comparisons with MoSi{sub 2}/ZrO{sub 2}
We have calculated the mechanical properties of brittle composites with spring-network (SN) model. The composites that we studied involve the transformation toughening effects and the accompanying micro-cracking. Our simulation results are consistent with experiments of MoSi{sub 2} toughened with ZrO{sub 2}. We found that the continuum mechanics predictions on linear dependence in e{sup T} and f about the transformation toughening are correct except some differences in the critical transformation stress dependence. By monitoring the stress changes due to the transformation and micro-cracking we are able to separate, for the first time, the contributions from these two competing effects. We found that the fracture toughness due to micro-cracks accompanying the transformation is a decreasing function of f and may be negative for large f. We also found that the fracture toughness of the composites increases as the modulus, interfacial cohesion, and uniformity of particle distributions increases.
Date:
December 31, 1993
Creator:
Chen, S. P.
Object Type:
Article
System:
The UNT Digital Library
Broad belts of shear zones: The common form of surface rupture produced by the 28 June 1992 Landers, California, earthquake
Surface rupturing during the 28 June 1992, Landers, California earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en echelon fault zones with a total length of about 80 km. The offsets were accommodated generally not by faults -- distinct slip surfaces -- but rather by shear zones, tabular bands of localized shearing. In long, straight stretches of fault zones at Landers the rupture is characterized by telescoping of shear zones and intensification of shearing: broad shear zones of mild shearing, containing narrow shear zones of more intense shearing, containing even-narrower shear zones of very intense shearing, which may contain a fault. Thus the ground ruptured across broad belts of shearing with subparallel walls, oriented NW. Each broad belt consists of a broad zone of mild shearing, extending across its entire width (50 to 200 m), and much narrower (a few m wide) shear zones that accommodate most of the offset of the belt and are portrayed by en echelon tension cracks. In response to right-lateral shearing, the slices of ground bounded by the tension cracks rotated in a clockwise sense, producing left lateral shearing, and the slices were forced against the …
Date:
December 31, 1993
Creator:
Johnson, A.M.; Cruikshank, K.M. & Fleming, R.W.
Object Type:
Report
System:
The UNT Digital Library
Brookhaven highlights. Report on research, October 1, 1992--September 30, 1993
This report highlights the research activities of Brookhaven National Laboratory during the period dating from October 1, 1992 through September 30, 1993. There are contributions to the report from different programs and departments within the laboratory. These include technology transfer, RHIC, Alternating Gradient Synchrotron, physics, biology, national synchrotron light source, applied science, medical science, advanced technology, chemistry, reactor physics, safety and environmental protection, instrumentation, and computing and communications.
Date:
December 31, 1993
Creator:
Rowe, M. S.; Belford, M.; Cohen, A.; Greenberg, D. & Seubert, L.
Object Type:
Report
System:
The UNT Digital Library
Bulk and defect properties of ordered intermetallics
First-principles calculations based on the local-density-functional theory have been used to investigate the factors governing strength of ordered intermetallic alloys. Unlike Ni{sub 3}Al, calculated elastic constants and shear fault energies indicate anomalous yield strength behavior is not likely to occur in Ni{sub 3}Si. This suggests the inadequacy of cross-slip-pinning model to explain the strength anomaly in the L1{sub 2} structure. For strongly ordered NiAl, the defect structure is dominated by two types of defects -- monovacancies on the Ni sites and substitutional antisite defects on the Al sites. By contrast, for Ni{sub 3}Al, absence of structural vacancies and deviations from stoichiometry are accommodated by substitutional antisite defects on both sublattices. Intrinsic strengthening mechanisms in TiAl are discussed in terms of calculated elastic constants and shear fault energies. Because of reduced fault energies at the {gamma}/{alpha}{sub 2} interface, slip and twinning contribute significantly to high shear deformation of the lamellar structure.
Date:
December 31, 1993
Creator:
Fu, C. L. & Yoo, M. H.
Object Type:
Article
System:
The UNT Digital Library
Calculations of neutron and proton radii of cesium isotopes. Final report, April 23--September 30, 1993
This task involved the calculation of neutron and proton radii of cesium isotopes. The author has written a computer code that calculates radii according to two models: Myers 1983 and FRDM 1992. Results of calculations in both these models for both cesium and francium isotopes are attached as figures. He is currently interpreting these results in collaboration with D. Vieira and J.R. Nix, and they expect to use the computer code for further studies of nuclear radii.
Date:
December 31, 1993
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Calibration and characterization of a low level waste assay system
In today`s rapidly changing regulatory environment, increasingly detailed information is required about the composition of items intended for disposal. We have examined a system that can be used to measure the radioactivity in a container of waste destined for disposal. In order to better understand the capabilities and limitations of the system, we performed a number of measurements to calibrate and characterize this system. The results of this characterization including detectability limits for {sup 235}U and {sub 239}Pu are presented.
Date:
December 31, 1993
Creator:
Giesler, G. C.; Henry, S. A.; Johnson, S. L. & Vehar, D. W.
Object Type:
Article
System:
The UNT Digital Library