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(Conversion of acetic acid to methane by thermophiles: Progress report)

Description: The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.
Date: January 1, 1991
Creator: Zinder, S.
Partner: UNT Libraries Government Documents Department

Development and utilization of new diagnostics for dense-phase pneumatic transport

Description: In 1988, we proposed a program to develop new diagnostics for dense gas-solid suspensions, with particular interest toward the dense pneumatic transport of cohesive solid plugs. This program included three main objectives, as follows: to develop probes for local measurements of (1) local particle volume fraction and (2) individual particle velocities in dense gas-solid flows; and (3) to construct a bench-scale setup for transporting dense cohesive solid plugs and to analyze data from the resulting tests.
Date: March 2, 1992
Creator: Louge, M. & Jenkins, J.T.
Partner: UNT Libraries Government Documents Department

Deep crustal sediment study: Widespread Precambrian layered rocks (Sedimentary ) beneath the US midcontinent

Description: A thick sequence of layered rocks occurs beneath the Phanerozoic platform strata which blanket the US midcontinent. Observed on COCORP deep reflection data in southern Illinois and Indiana and in SW Oklahoma and adjacent Texas, this sequence is locally 1--3 times as thick as the overlying Paleozoic cover, but the origin of this sequence, its ultimate lateral extent, and resource potential are unknown. The objective of this project is to seek and reprocess seismic reflection data provided by industry from the US midcontinent and together with the COCORP deep reflection data and information from the scattered basement-penetrating drill holes, to begin to constrain the distribution, origin and evolution of this enigmatic layered sequence, particularly to evaluate if sedimentary material may be an important constituent (i.e., deep gas potential).
Date: January 1, 1992
Creator: Hauser, E.C.
Partner: UNT Libraries Government Documents Department

Identification and validation of heavy metal and radionuclide accumulating terrestrial plant species. Quarterly technical progress report, June 21, 1995--September 20, 1995

Description: This quarterly report describes experiments on uptake of a variety of heavy metals by plants. Titles of report sections are (1) Alleviation of heavy-metal induced micronutrient deficiency through foliar fertilization, (2) Second screen for Zn, Cu, and Cd accumulation, (3) Characterization of the root Zn hyperaccumulation by Thlaspi caerulescens, (4) Comparison of commercial Brassica accessions obtained from the Iowa seed bank, (5) Second screening experiment for the accumulation of Cs and Sr by plants, (6) Effect of Ca on Cs and Sr accumulation by selected dicot species, and (7) Preliminary investigations into the forms of uranium taken up by plants.
Date: December 31, 1995
Creator: Kochian, L.
Partner: UNT Libraries Government Documents Department

Dense inclined flows: Theory and experiments. Final report

Description: Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum ad energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that focuses on such flows. the effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. A goal of the project is to provide a sound theoretical and experimental base for a better understanding of the behavior and properties of multiphase flow and solid transport.
Date: December 1, 1995
Creator: Jenkins, J.T. & Louge, M.Y.
Partner: UNT Libraries Government Documents Department

Studies of III-V compounds is the megabar range. Final report, July 15, 1993--July 14, 1996

Description: The core of this work was the study of phase transformations and equation of state of the III-V compounds. The research studies provided an excellent test of theories of molecular bonding and this work was carefully followed by several well known theorists. The work during the present grant involved studies on the nitrides, AlN, GaN and InN, materials which are expected to have great commercial significance. These materials all transformed to the rocksalt structure. The authors also were the first to find III-V materials, AlAs and AlP, which transformed to the NiAs structure. They obtained the equation of state of BP but stopped short of the pressure later calculated to be the transition pressure. They studied the transition in AlSb. In BAs, where theory preceded experiment, they found, that instead of transforming to a new crystal structure as predicted, BAs went amorphous. Finally, a review of the high pressure behavior of III-V compounds was published.
Date: June 1, 1997
Creator: Ruoff, A.L.
Partner: UNT Libraries Government Documents Department

An innovative educational program for residential energy efficiency. Final report

Description: Recognizing the importance of energy conservation, under sponsorship of the US Department of Energy, Cornell University conducted a research and demonstration project entitled An Innovative Educational Program for Residential Energy Efficiency. The research project examined the amount of residential energy that can be saved through changes in behavior and practices of household members. To encourage these changes, a workshop was offered to randomly-selected households in New York State. Two surveys were administered to household participants (Survey 1 and Survey 2, Appendix A) and a control group; and a manual was developed to convey many easy but effective ways to make a house more energy efficient (see Residential Manual, Appendix B). Implementing methods of energy efficiency will help reduce this country`s dependence on foreign energy sources and will also reduce the amount of money that is lost on inefficient energy use. Because Cornell Cooperative Extension operates as a component of the land-grant university system throughout the US, the results of this research project have been used to develop a program that can be implemented by the Cooperative Extension Service nationwide. The specific goals and objectives for this project will be outlined, the population and sample for the research will be described, and the instruments utilized for the survey will be explained. A description of the workshop and manual will also be discussed. This report will end with a summary of the results from this project and any observed changes and/or recommendations for future surveys pertaining to energy efficiency.
Date: September 1, 1996
Creator: Laquatra, J. & Chi, P.S.K.
Partner: UNT Libraries Government Documents Department

Photoionization mass spectrometry of combustion radicals. Final technical report

Description: Fundamental research on the combustion of halogenated organic compounds with emphasis on reaction pathways leading to the formation of chlorinated organic compounds and the development of continuous emission monitoring methods will assist in DOE efforts in the management and control of hazardous chemical wastes. Selective laser ionization techniques are used in the laboratory for the measurement of concentration profiles of radical intermediates in chlorinated hydrocarbon flames. A novel flame-sampling VUV laser photoionization mass spectrometer, constructed with DOE funding, is in use for these studies. Progress is reported here on the use of this new facility in the development, refinement, and verification of chemical kinetic models describing the thermal destruction of toxic chlorocarbons commonly found in chemical wastes. In the past two years the author has used the flame sampling VUV laser ionization mass spectrometer system for studies of chlorocarbon-doped methane/oxygen flames. Relative concentration profiles and photoionization efficiency curves have been measured for over two-dozen key reaction intermediates. Preliminary kinetic models have been developed that promise an improved understanding of chlorocarbon chemistry under laboratory flame conditions.
Date: December 31, 1998
Creator: Cool, T.A.
Partner: UNT Libraries Government Documents Department

Nonlinear dynamics of fluid-structure systems. Final technical report for period January 5, 1991 - December 31, 1997

Description: The technical research was directed at problems involving the dynamics of fluid flow and elastic structures. Such problems occur in heat-exchange systems in energy generating plants. Fluid excited vibrations of structures can result in unwanted impact forces which can lead to metal fatigue failures. Mathematical theories based on linear models have been used for several decades. In this research the authors explored the phenomena associated with nonlinear effects using experimental models, mathematical models and numerical computation. A number of nonlinear effects were observed experimentally including chaotic dynamics, multi-fractal Poincare maps, quasi-periodic vibrations, subcritical Hopf bifurcations, helical waves in a tube row and spatial localization.
Date: July 20, 1999
Creator: Moon, Francis C.
Partner: UNT Libraries Government Documents Department

Nucleation, propagation, electronic levels and elimination of misfit dislocations in III-V semiconductor interfaces. Final report

Description: This report discusses the following topics: strained layer defects; the structural and electronic characteristics of misfit dislocations; requirements for the growth of high quality, low defect density InGaAs strained epitaxial layers; the isolation and nucleation of misfit dislocations in strained epitaxial layers grown on patterned, ion-damaged GaAs; the effect of pattern substrate trench depth on misfit dislocation density; the thermal stability of lattice mismatched InGaAs grown on patterned GaAs; misfit dislocations in ZnSe strained epitaxial layers grown on patterned GaAs; and the measurement of deep level states caused by misfit dislocations in InGaAs/GaAs grown on patterned GaAs substrates.
Date: March 1, 1995
Creator: Watson, G.P. & Matragrano, M.
Partner: UNT Libraries Government Documents Department

Dense inclined flows: Theory and experiments. Quarterly technical progress report, July 1, 1995--September 30, 1995

Description: Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum and energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that will focus on dense entry flows down inclines. The effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. In the present reporting period, we have completed the experiments with the bumpy base consisting of random two-dimensional packings of l nun glass spheres; we have derived boundary conditions for a bumpy frictionless boundary for other than small slip velocities; and we have made numerical studies of hydraulic equations using a simple Lagrangian code that we have developed. We are now in the process of writing the final report and a journal article summarizing our findings.
Date: December 31, 1995
Partner: UNT Libraries Government Documents Department

Collective acceleration of electrons and ions in a high current relativistic electron beam. Final report

Description: This report describes work carried out on DOE contract number DE-AC02-80ER10569 during the period December 15, 1979 to May 31, 1992. The original purpose of this research was to investigate the use of slow space charge waves on weakly relativistic electron beams for ion acceleration. The work had three major objectives: development of a suitable ion injector, growth and study of the properties of slow space charge waves on an electron beam, and a combination of the two components into a suitable proof-of-principle demonstration of the wave accelerator. Work focused on the first two of these objectives. Control of the space charge waves` phase velocity was not obtained to the degree required for a working accelerator, so the project was duly terminated in favor of a program which focused on generating ultra high power microwave signals suitable for use in the next linear collider. Work done to develop suitable efficient, inexpensive, phase-stable microwave sources, with peak powers of up to 1 GW in the X band in pulses shorter than 1 ns, is described. Included are lists of the journal and conference papers resulting from this work, as well as a list of graduate students who completed their Ph.D. studies on the projects described in this report.
Date: December 31, 1992
Creator: Nation, J.A.
Partner: UNT Libraries Government Documents Department

Establishing a quantitative functional relationship between capillary pressure saturation and interfacial area. 1998 annual progress report

Description: 'Through an integrated and focused research program that is comprised of theoretical, computational and experimental efforts this research effort is directed at: (1) improving on newly developed laboratory techniques to quantify and directly measure the functional relationship between phase interfacial area (a), saturation (S) and capillary pressure (Pc), (2) developing new computational algorithms in conjunction with laboratory measurements to predict Pc, S and a, (3) testing existing theory and developing new theory to describe the relationship between Pc, S and a at the large scale, and (4) synthesizing the results of the experimental, computational and theoretical investigative efforts to develop a generic model based upon an intrinsic soil metric to describe the functional dependence of Pc, S and a. The results of this research could be used to generate a site specific soil moisture characteristic surface. Ultimately the results of this research could serve as the foundation upon which the true health and safety risk of a site could be evaluated, the applicability of various remediation technologies examined, and the performance of implemented treatment strategies controlled. This report summarizes work after 18 months of a 3-year project. The authors are working to integrate the theory, experiments, and numerical simulations into a coherent approach to study the role of interfacial areas in porous media flow physics. The recent efforts have focused on quantifying the relationship between capillary pressure, saturation, and interfacial areas. The theory developed by Gray et al. (1998) indicates clearly that the traditional relationship between capillary pressure and saturation is incomplete, and interfacial area per unit volume must be added to the functional dependence. The theory does not, however, provide the form of that functional dependence; determination of this relationship must be done experimentally. To this end, both the network modelling and the PVI approach are being pursued.'
Date: June 1, 1998
Creator: Montemagno, C.D.; Celia, M. & Gray, W.G.
Partner: UNT Libraries Government Documents Department

Dense inclined flows: Theory and experiments. Quarterly technical progress report, April 1--June 30, 1995

Description: Rapid, gravity-driven flows of granular materials down inclines pose a challenge to the understanding of solids flow. Even in situations in which the flow is steady and two-dimensional, the details of how momentum and energy are balanced within the flow and at the bottom boundary are not well understood. Thus the authors have undertaken a research program integrating theory, computer simulation, and experiment that will focus on dense entry flows down inclines. The effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. In the present reporting period, the authors began a series of measurements in the chute facility with a bumpy boundary constructed using random two-dimensional packings of 1 mm glass spheres. At the inclination of 19{degree} and at several gate openings, they measured mass flow rate and mass holdup, as well as granular temperature and collision frequency at the bottom wall of the chute. By recording simultaneously the collisional normal stress at the bottom wall and the mass holdup above it, the experiments revealed that, unlike the flat boundary, only a small fraction of the weight of particles is supported by direct impact. The authors have also completed measurements of the impact properties for several binary collisions of nearly spherical particles used in this and other projects. A table summarizes the data obtained.
Date: October 1, 1995
Partner: UNT Libraries Government Documents Department

Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species, Quarterly technical progress report, December 20, 1995--March 20, 1995

Description: Although the period covered by this progress report began on December 20, 1994, which was the date that DOE approved the Interagency Agreement, the agreement was not approved by USDA until January 9, 1995 and the first scientists working on the project were not hired until February 1, 1995. The first goal of the research supported by the Interagency Agreement is to use hydroponic techniques to identify plant species and genotypes with potential for heavy metal hyperaccumulation for planting on a test site at Silverbow Creek and for radionuclide ({sup 90}Sr and {sup 137}Cs) accumulation on a test site at INEL, Idaho, later this year. The second goal of this research is to identify soil amendment procedures that will enhance the bioavailability of heavy metals and radionuclides in the soil without increasing the movement of the contaminants of concern (COC`s) into the groundwater. Our initial research covered in this report focuses on the first goal.
Date: December 1, 1995
Creator: Kochian, L.; Brady, D.; Last, M. & Ebbs, S.
Partner: UNT Libraries Government Documents Department

Nucleation, propagation, electronic levels and elimination of misfit dislocations in III-V semiconductor interfaces. Final report, September 1, 1986--August 31, 1993

Description: Misfit dislocations in gallium arsenides, indium arsenides, and zinc selenides are discussed. The growth of strained epitaxial layers, isolation and nucleation, thermal stability, and electronic and structural characteristics of misfit dislocations are described.
Date: March 1, 1995
Creator: Ast, D.G.; Watson, G.P. & Matragrano, M.
Partner: UNT Libraries Government Documents Department

Dense inclined flows: Theory and experiments. Quarterly technical progress report, January 1, 1995--March 31, 1995

Description: Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum and energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that will focus on dense entry flows down inclines. The effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. In the present reporting period, we have continued a series of measurements in the chute facility with a flat, frictional boundary. At several inclinations between 15.5{degrees} and 20{degrees}, and at several gate openings for each angle, we have measured mass flow rate and mass holdup, as well as granular temperature and collision frequency at the bottom wall of the chute. By recording simultaneously the collisional normal stress at the bottom wall and the mass holdup above it, the experiments reveal the fraction of the weight of particles that is supported by direct impact.
Date: August 1, 1995
Creator: Jenkins, J.T. & Louge, M.Y.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Partner: UNT Libraries Government Documents Department

The relaxation of the second moments in rapid shear flows of smooth disks

Description: This paper compares the results of numerical simulations for two- dimensional, rapid, homogeneous shear flows of identical, smooth, inelastic disks with the predictions of Jenkins and Richman (JFM 192, 313-328 (1988)) for the relaxation of the second moments of the velocity distribution function following a homogeneous, but anisotropic disturbance of their steady values. For nearly elastic disks, the time-history of the relaxation is in excellent agreement with the theory in both its dense and dilute limits. However, deviations are observed in the case of inelastic particles. 2 refs., 8 figs.
Date: January 1, 1991
Creator: Louge, M.Y. (Cornell Univ., Ithaca, NY (United States). Sibley School of Mechanical and Aerospace Engineering); Jenkins, J.T. (Cornell Univ., Ithaca, NY (United States). Dept. of Theoretical and Applied Mechanics) & Hopkins, M.A. (Army Cold Regions Research and Engineering Lab., Hanover, NH (United States))
Partner: UNT Libraries Government Documents Department

Nonlinear, distortive phenomena in solids: Martensitic, crack, and multiscale structures

Description: This ongoing program, from the beginning of the first three year grant 1988--1991 and now in the first year of the second phase 1991--1994, has been directed at developing both an understanding of the physics underlying structural transformations in real (alloy) materials as well as new theoretical methods which adequately describe the large (nonlinear) distortions which characterize such processes. We have had a particular interest in martensitic systems, first (1988--1991) in the equilibrium limits, and now (below) in phenomena associated with the transformation process.
Date: January 1, 1992
Creator: Krumhansl, J.A. & Sethna, J.P.
Partner: UNT Libraries Government Documents Department

Development and utilization of new diagnostics for dense-phase pneumatic transport

Description: Dense-phase pneumatic transport is an attractive means of conveying solids. Unfortunately, because of the high solid concentrations, this transport method is a difficult regime in which to carry out detailed measurements. Hence most details of the flow are unknown. In this context, the main objective of this work is to develop probes for local measurements of solid velocity and holdup in dense gas-solid flows. Because we anticipate the recent theories of rapid granular flows will bring insight to the dense pneumatic transport of particles, we have sought to substantiate these theories through computer simulations. There we have verified the theory of Hanes, Jenkins Richman (1988) for the rapid, steady shear flow of identical, smooth, nearly elastics disks driven by identical, parallel, bumpy boundaries. Because granular flows depend strongly on the nature of their interaction with a boundary, we have verified the boundary conditions calculated by Jenkins (1991) for spheres interacting with a flat, frictional surface. During the previous reporting period, we began a study of the time relaxation of the second moment of velocity fluctuations for a collection of disks undergoing simple shear. In the present reporting period, we have completed this study of relaxation by comparing results of simulations with the theoretical predictions of Jenkins and Richman (1988). In addition, we have concluded a series of experiments with flour plugs in the dense-phase pneumatic setup. Finally, we have established several industrial contacts to transfer the diagnostic techniques developed under this contract. 7 refs., 11 figs.
Date: January 1, 1991
Partner: UNT Libraries Government Documents Department

(Defect studies in III-V thin film semiconductors)

Description: Our primary research objective in 90/91 has been to continue studying misfit dislocation confinement by patterning substrates into mesas before the epitaxial growth of strained layers. This report presents progress for many of the areas of our research. (JL)
Date: January 1, 1991
Partner: UNT Libraries Government Documents Department

Uhv-stem studies on nucleation and growth of thin metal silicide films on silicon

Description: Work centers on the multiple imaging and spectroscopy operating modes of an ultra-high vacuum scanning transmission electron microscope. Three research topics were: single atom structures on Si, grain boundaries in Ni[sub 3]Al, and the simulations to interpret the observations. 5 figs, 21 refs.
Date: January 1, 1992
Creator: Silcox, J. & Kirkland, E.J.
Partner: UNT Libraries Government Documents Department

Reaction and diffusion in turbulent combustion

Description: The primary objective of the research is to use Direct Numerical Simulations (DNS) to study turbulent non-premixed combustion. In DNS, the fluid mechanical and thermochemical conservation equations are solved by an accurate numerical method, without any averaging or turbulence modeling. In principle, then, DNS could be used to study a turbulent diffusion flame, for example. In practice, however, computational limitations severely restrict the flows that can be simulated. For non-reacting flows, DNS is restricted to simple geometries and moderate Reynolds number. For reacting flows there are severe restrictions on the thermochemistry. Our approach is to use DNS to study very simple turbulent reactive flows, that contain qualitatively the same phenomena real flames. Based on the insights and information gained, statistical models will be developed and tested. These models are then applicable to the turbulent flames of practical importance.
Date: October 2, 1991
Creator: Pope, S.B.
Partner: UNT Libraries Government Documents Department