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Experimental Investigation and High Resolution Simulator of In-Situ Combustion Processes

Description: Accurate simulation of in-situ combustion processes is computationally very challenging because the spatial and temporal scales over which the combustion process takes place are very small. In this current and eleventh report, we report on the development of a virtual kinetic cell (VKC) that aids the study of the interaction between kinetics and phase behavior. The VKC also provides an excellent tool for developing and testing specialized solvers for the stiff kinetics encountered in ISC processes.
Date: July 1, 2006
Creator: Gerritsen, Margot & Kovscek, Anthony R.
Partner: UNT Libraries Government Documents Department

Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms

Description: The goal of this research was to provide an improved understanding and predictive capability of coupled hydrological and geochemical mechanisms that are responsible for the accelerated migration and immobilization of radionuclides and toxic metals in the badose zone beneath the Hanford Tank Farms.
Date: July 21, 2006
Creator: Fendorf, Scott & Jardine, Phil
Partner: UNT Libraries Government Documents Department

Femto-second pulses of synchrotron radiation

Description: A method capable of producing femto-second pulses of synchrotron radiation is proposed. It is based on the interaction of femto-second light pulses with electrons in a storage ring. The application of the method to the generation of ultra-short x-ray pulses at the Advance Light Source of Lawrence Berkeley National Laboratory has been considered. The same method can also be used for extraction of electrons from a storage ring in ultra-short series of microbunches spaced by the periodicity of light wavelength.
Date: July 1, 1995
Creator: Zholents, A. A. & Zolotorev, M. S.
Partner: UNT Libraries Government Documents Department

Measurements of {Gamma}(Z{sup O} {yields} b{bar b})/{Gamma}(Z{sup O} {yields} hadrons) using the SLD

Description: The quantity R{sub b} = {Gamma}(Z{sup o} {yields}b{bar b})/{Gamma}(Z{sup o} {yields} hadrons) is a sensitive measure of corrections to the Zbb vertex. The precision necessary to observe the top quark mass dependent corrections is close to being achieved. LEP is already observing a 1.8{sigma} deviation from the Standard Model prediction. Knowledge of the top quark mass combined with the observation of deviations from the Standard Model prediction would indicate new physics. Models which include charged Higgs or light SUSY particles yield predictions for R{sub b} appreciably different from the Standard Model. In this thesis two independent methods are used to measure R{sub b}. One uses a general event tag which determines R{sub b} from the rate at which events are tagged as Z{sup o} {yields} b{bar b} in data and the estimated rates at which various flavors of events are tagged from the Monte Carlo. The second method reduces the reliance on the Monte Carlo by separately tagging each hemisphere as containing a b-decay. The rates of single hemisphere tagged events and both hemisphere tagged events are used to determine the tagging efficiency for b-quarks directly from the data thus eliminating the main sources of systematic error present in the event tag. Both measurements take advantage of the unique environment provided by the SLAC Linear Collider (SLC) and the SLAC Large Detector (SLD). From the event tag a result of R{sub b} = 0.230{plus_minus}0.004{sub statistical}{plus_minus}0.013{sub systematic} is obtained. The higher precision hemisphere tag result obtained is R{sub b} = 0.218{plus_minus}0.004{sub statistical}{plus_minus}0.004{sub systematic}{plus_minus}0.003{sub Rc}.
Date: July 1, 1995
Creator: Neal, H.A. Jr. II
Partner: UNT Libraries Government Documents Department

New phenomena beyond both the standard model and MSSM

Description: The Standard Model (SM) is in complete agreement with present experimental data. Nevertheless, it is believed to leave many questions unanswered, and this belief has resulted in numerous attempts to find a more fundamental underlying theory. One key ingredient in the extrapolation of the SM to higher energies is to identify the complete particle spectrum at the electroweak scale. Two popular examples of theories which populate the TeV scale with a plethora of new particles are supersymmetry and technicolor. This has resulted in extensive searches for super- and techni-particles, which have been reported elsewhere at this meeting. In this talk, the author identifies other possible manifestations of new physics, and discusses their implications on hadron collider physics.
Date: July 1, 1995
Creator: Hewett, J.L.
Partner: UNT Libraries Government Documents Department

Energy changes in transforming solids annual report, February 1, 1994--January 31, 1995

Description: The recently formulated thermodynamic theory of elastic bodies prone to damage has been further developed. This formalism is based on classical thermodynamics using the local state approximation, with a significant amount of attention paid to non-isothermal processes. Certain concepts are being clarified via the use of Onsager`s reciprocal relations. Planned work includes a significant effort to develop the fundamental elements of an exact thermodynamic theory, which until now has been restricted to the one-dimensional case, and will be extended to two and three dimensions. Information is also included on publications in print, in press, and submitted since the last report (8/92).
Date: July 1, 1993
Creator: Herrmann, G. & Barnett, D.M.
Partner: UNT Libraries Government Documents Department

EXPERIMENTAL INVESTIGATION AND HIGH RESOLUTION SIMULATOR OF IN-SITU COMBUSTION PROCESSES

Description: Accurate simulation of in-situ combustion processes is computationally very challenging because the spatial and temporal scales over which the combustion process takes place are very small. In this third quarterly report of our DoE funded research, we continue the discussion of the design of a new simulation tool based on an efficient Cartesian Adaptive Mesh Refinement technique that allows much higher grid densities to be used near typical fronts than current simulators. Also, we show preliminary results for the one-dimensional in-situ combustion simulator, which will serve as the foundation for the development of a three-dimensional simulator that can handle realistic permeability heterogeneity. On the experimental side, the combustion kinetic apparatus and the combustion tube are now fully operational, and a series of successful combustion tube runs were performed that clearly showed additives allow combustion of poorly reactive oils. We have also started scanning electron microscope (SEM) analysis to investigate the sand-clay-salt mixtures that are used for combustion in which we focus on grain sizes, shapes, orientations, characteristic inter-structures, and element analysis.
Date: July 1, 2004
Creator: Gerritsen, Margot & Kovscek, Anthony R.
Partner: UNT Libraries Government Documents Department

Microbially Mediated Immobilization of Contaminants Through In Situ Biostimulation

Description: In most natural environments, a multitude of metabolic substrates are resent simultaneously. Organisms that can utilize uranium as a metabolic substrate for respiration also may have the ability to use a variety of other oxidized substrates as electron acceptors. Thus, these substrates are, in effect, competing for electrons that are being passed through the electron transport chain during respiration. To assess the feasibility of in situ immobilization of uranium in subsurface environments and to understand the cycling of uranium, it is necessary to discern the chemical and/or biological conditions dictating which terminal electron acceptor(s) will be utilized.
Date: July 31, 2003
Creator: Fendorf, Scott
Partner: UNT Libraries Government Documents Department

Seismic and Rockphysics Diagnostics of Multiscale Reservoir Textures

Description: This final technical report summarizes the results of the work done in this project. The main objective was to quantify rock microstructures and their effects in terms of elastic impedances in order to quantify the seismic signatures of microstructures. Acoustic microscopy and ultrasonic measurements were used to quantify microstructures and their effects on elastic impedances in sands and shales. The project led to the development of technologies for quantitatively interpreting rock microstructure images, understanding the effects of sorting, compaction and stratification in sediments, and linking elastic data with geologic models to estimate reservoir properties. For the public, ultimately, better technologies for reservoir characterization translates to better reservoir development, reduced risks, and hence reduced energy costs.
Date: July 1, 2005
Creator: Mavko, Gary
Partner: UNT Libraries Government Documents Department

Flow and displacement of Bingham plastics in porous media. Topical report

Description: Bingham plastics, which exhibit a finite yield stress at zero shear rate, have been used to model the flow behavior of certain heavy oils at reservoir conditions. In such fluids, the onset of flow and displacement occurs only after the applied pressure gradient exceeds a minimum value. Understanding the flow behavior of such fluids has been limited to phenomenological approaches. In this paper, we present numerical simulations and experimental visualization of flow and immiscible displacement of Bingham plastics in porous media using micromodels. First, we describe a novel pore network simulation approach to determine the onset of flow. The dependence of the critical yield stress on the pore-size distribution is discussed. Visualization experiments of the constant-rate immiscible displacement of Bingham plastics in glass micromodels and Hele-Shaw cells are next presented. The process is subsequently simulated in a pore network. Experiments are successfully simulated with the pore network model. We discuss the effect of the yield stress and injection rate on the displacement patterns. We also propose a classification of the displacement patterns, similar to that for Newtonian displacement.
Date: July 1, 1995
Creator: Shah, C.; Kharabaf, H. & Yortsos, Y.
Partner: UNT Libraries Government Documents Department

Scaling of bubble growth in a porous medium. Topical report

Description: Processes involving liquid-to-gas phase change in porous media are routinely encountered, for example in the recovery of oil, geothermal processes, nuclear waste disposal or enhanced heat transfer. They involve diffusion (and convection) in the pore space, driven by an imposed supersaturation in pressure or temperature. Phase change proceeds by nucleation and phase growth. Depending on pore surface roughness, a number of nucleation centers exist, thus phase growth occurs from a multitude of clusters. Contrary to growth in the bulk or in a Hele-Shaw cell, however, growth patterns in porous media are disordered and not compact. As in immiscible displacements, they reflect the underlying pore microstructure. The competition between multiple clusters is also different from the bulk. For example, cluster growth may be controlled by a combination of diffusion (e.g. Laplace equation in the quasi-static case) with percolation. Novel growth patterns axe expected from this competition. While multiple cluster growth is important, the simpler problem of single-bubble growth is still not well understood. In this section, we focus on the growth of a single bubble, subject to a fixed far-field supersaturation (e.g. by lowering the pressure in a supersaturated solution or by raising the temperature in a. superheated liquid). Our emphasis is on deriving a scaling theory for growth at conditions of quasi-static diffusion, guided by recent experimental observations. Visualization of bubble growth in model porous media was recently conducted using 2-D etched-glass micromodels.
Date: July 1, 1995
Creator: Satik, C.; Yortsos, Y. & Li, X.
Partner: UNT Libraries Government Documents Department

HEAVY AND THERMAL OIL RECOVERY PRODUCTION MECHANISMS

Description: This technical progress report describes work performed from April 1 through June 30, 2002, for the project ''Heavy and Thermal Oil Recovery Production Mechanisms.'' We investigate a broad spectrum of topics related to thermal and heavy-oil recovery. Significant results were obtained in the areas of multiphase flow and rock properties, hot-fluid injection, improved primary heavy oil recovery, and reservoir definition. The research tools and techniques used are varied and span from pore-level imaging of multiphase fluid flow to definition of reservoir-scale features through streamline-based history-matching techniques. Briefly, experiments were conducted to image at the pore level matrix-to-fracture production of oil from a fractured porous medium. This project is ongoing. A simulation studied was completed in the area of recovery processes during steam injection into fractured porous media. We continued to study experimentally heavy-oil production mechanisms from relatively low permeability rocks under conditions of high pressure and high temperature. High temperature significantly increased oil recovery rate and decreased residual oil saturation. Also in the area of imaging production processes in laboratory-scale cores, we use CT to study the process of gas-phase formation during solution gas drive in viscous oils. Results from recent experiments are reported here. Finally, a project was completed that uses the producing water-oil ratio to define reservoir heterogeneity and integrate production history into a reservoir model using streamline properties.
Date: July 1, 2002
Creator: Kovscek, Anthony R.
Partner: UNT Libraries Government Documents Department

Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms

Description: This project addresses the goals of the Environmental Management Sciences Program (EMSP) that seeks innovative basic research to benefit cleanup technologies and decision-making strategies for contaminated environments. Our proposal specifically addresses Hanford research needs in subsurface science by contributing to the objectives of the Tank Farm Vadose Characterization Project and the 200 Area Remedial Action Project (http://www.bhi-erc.com/projects/vadose/sandt/stdocs/subneeds.pdf) which are components of the Hanford Site Groundwater/Vadose Zone Integration Project (Integration Project). The work described in this proposal will advance the technological and scientific needs associated with the long-term management of the enormous inground inventories of 235/238U, 99Tc, 60Co, and Cr(VI) present at the Hanford site. We believe that scientifically defensible predictions of contaminant transport and strategies for remediation must be based upon a field-relevant understanding of coupled hydrological and geochemical processes that control subsurface contaminant fate and transport. This research project investigates the migration of 235/238U, 99Tc, 60Co, and Cr(VI) in undisturbed sediments from the Hanford site using realistic experimental protocols designed to delineate complex hydrological and geochemical processes controlling contaminant movement. The work complements and builds upon our current EMSP project 70219, which is scheduled to end this year, and our Hanford S&T project with PNNL (John Zachara as PI) that focuses on 90Sr transport beneath the BX tanks. The specific research goals of the following proposal are: (1) to provide an improved understanding of how preferential vertical and lateral flow, and the formation of immobile water influence the transport of radionuclides and toxic metals in heterogeneous, laminated sediments; (2) to quantify the rates and mechanisms of radionuclide and toxic metal interaction with the solid phase under various hydrologic conditions; and (3) provide new insights into how physical and mineralogical heterogeneities (e.g. stratification, pore regime connectivity, mineral composition along flowpaths) influence contaminant retardation and the degree of geochemical nonequilibrium during ...
Date: July 23, 2003
Creator: Jardine, Philip M.; Fendorf, Scott E. & Mayes, Melanie
Partner: UNT Libraries Government Documents Department

Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms

Description: Provide an improved understanding of how preferential vertical and lateral flow, and the formation of immobile water influence the transport of radionuclides and toxic metals in heterogeneous, laminated sediments. Quantify the rates and mechanisms of radionuclide and toxic metal interaction with the solid phase under various hydrologic conditions. Provide new insights into how physical and mineralogical heterogeneities (e.g. stratification, pore regime connectivity, mineral composition along flowpaths) influence contaminant retardation and the degree of geochemical nonequilibrium during transport.
Date: July 18, 2003
Creator: Fendorf, Scott & Jardine, Phil
Partner: UNT Libraries Government Documents Department

Measurement of the Z{sup 0}-lepton coupling asymmetries A{sub l}

Description: The authors present direct measurements of the Z{sup 0}-lepton coupling asymmetries, A{sub e}, A{sub {mu}}, and A{sub {tau}}. It is based on a data sample selected from 170 k Z{sup 0} decays collected by the SLD detector. The Z`s are produced by collisions of polarized e{sup {minus}} with unpolarized e{sup +} bunches at SLC. The couplings are extracted from the measurement of the left-right forward-backward asymmetry for each lepton species. The preliminary results (using information from all leptonic data for A{sub e}) are: A{sub e} = 0.148 {+-} 0.016, A{sub {mu}} = 0.102 {+-} 0.033 and A{sub {tau}} = 0.190 {+-} 0.034.
Date: July 22, 1996
Creator: Abe, K.; Abe, K.; Abt, I. & Collaboration, SLD
Partner: UNT Libraries Government Documents Department

Integrated Genome-Based Studies of Shewanella Ecophysiology

Description: We have constructed in-frame deletions of 7 of the 10 PAS-GGDEF-EAL proteins in Shewanella oneidensis MR-1. We are currently in the process of characterizing the deletion mutants under a wide range of growth conditions. In addition to characterizing growth, we will also examine the biofilm formation of the deletion mutants. In addition to the genetic analyses of the mutants, we are also interested in comparing the activities of the various PAS-GGDEF-EAL proteins. Proteins containing PAS, GGDEF and EAL amino acid sequence motifs may play an important role in regulating c-di-GMP signaling in response to environmental conditions. A genetic and biochemical analysis into the roles of these proteins is underway. PDE activity was observed for several PAS-GGDEF-EAL proteins. One of these proteins, SO0427, also demonstrates possible DGC activity in vitro. Currently, we are studying the growth, motility and biofilm formation characteristics of deletion mutants, as well as the activity of the purified proteins.
Date: July 12, 2011
Creator: Spormann, Alfred
Partner: UNT Libraries Government Documents Department

The Determination of Molecular Structure From Rotational Spectra

Description: An analysis is presented concerning the average molecular configuration variations and their effects on molecular structure determointions. It is noted that the isotopic dependence of the zero-point is often primarily governed by the isotopic variation of the average molecular configuration. (J.R.D.)
Date: July 1, 1962
Creator: Laurie, V. W. & Herschbach, D. R.
Partner: UNT Libraries Government Documents Department

Table of Vibrational Force Constants

Description: Tabulations are included for: vibrational and rotational parameters for diatomic molecules; quadratic, cubic, and quartic vibrational force constants of diatomic molecules; parameters for empirical functibns relating force constants to bond length; and cubic force constants for bond stretching in polyatomic molecules. (B.O.G.)
Date: July 1, 1961
Creator: Herschbach, D. R. & Laurie, V. W.
Partner: UNT Libraries Government Documents Department