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Conceptual design analysis of an MHD power conversion system for droplet-vapor core reactors. Final report

Description: A nuclear driven magnetohydrodynamic (MHD) generator system is proposed for the space nuclear applications of few hundreds of megawatts. The MHD generator is coupled to a vapor-droplet core reactor that delivers partially ionized fissioning plasma at temperatures in range of 3,000 to 4,000 K. A detailed MHD model is developed to analyze the basic electrodynamics phenomena and to perform the design analysis of the nuclear driven MHD generator. An incompressible quasi one dimensional model is also developed to perform parametric analyses.
Date: December 31, 1995
Creator: Anghaie, S. & Saraph, G.
Partner: UNT Libraries Government Documents Department

Thermodynamics and electrodynamics of unusual narrow-gap semiconductors

Description: This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL) that has led to a fully funded DOE program to continue this work. The project was directed toward exploring the Ettingshausen effect, which is the direct extension of the familiar Peltier-effect refrigerator (the process used in popular coolers that run off automotive electrical power) in which a magnetic field is used to enhance refrigeration effects at temperatures well below room temperature. Such refrigeration processes are all-solid-state and are of potentially great commercial importance, but essentially no work has been done since the early 1970s. Using modern experimental and theoretical techniques, the authors have advanced the state-of-the-art significantly, laying the groundwork for commercial cryogenic solid-state refrigeration.
Date: December 1998
Creator: Migliori, A.; Darling, T. W.; Trugman, S. A.; Freibert, F.; Moshopoulou, E. & Sarrao, J. L.
Partner: UNT Libraries Government Documents Department

Task 38 - commercial mercury remediation demonstrations: Thermal retorting and physical separation/chemical leaching. Topical report, December 1, 1994--June 30, 1996

Description: Results are presented on the demonstration of two commercial technologies for the removal of mercury from soils found at natural gas metering sites. Technologies include a thermal retorting process and a combination of separation, leaching, and electrokinetic separation process.
Date: December 31, 1998
Creator: Charlton, D.S.; Fraley, R.H. & Stepan, D.J.
Partner: UNT Libraries Government Documents Department

Microfluidic Engineering

Description: The ability to generate high pressures using electrokinetic pumping of liquid through porous media is reported. Pressures in excess of 8000 psi have been achieved using capillaries (< 100 {micro}m i.d.) packed with micron-size silica beads. A model is presented which accurately predicts absolute pressures, flowrates and power conversion efficiencies as well as the experimentally observed dependencies on pore size, applied electric field and electrical properties of the fluid. This phenomenon offers the possibility of creating a new class of microscale fluid devices, electrokinetic pumps and valves, where the performance improves with scale-down by taking advantage of microscale processes.
Date: December 1, 1998
Creator: Paul, Phillip H.
Partner: UNT Libraries Government Documents Department


Description: The objective of this research was to demonstrate that electrokinetics can be used to remove colloidal coal and mineral particles from coal-washing ponds and lakes without the addition of chemical additives such as salts and polymeric flocculants. The specific objectives were: Design and develop a scaleable electrophoresis apparatus to clarify suspensions of colloidal coal and clay particles; Demonstrate the separation process using polluted waste water from the coal-washing facilities at the coal-fired power plants in Centralia, WA; Develop a mathematical model of the process to predict the rate of clarification and the suspension electrical properties needed for scale up.
Date: December 18, 1999
Creator: Davis, E. James
Partner: UNT Libraries Government Documents Department


Description: Large quantities of mixed low level waste (MLLW) that fall under the Toxic Substances Control Act (TSCA) exist and will continue to be generated during D&D operations at DOE sites across the country. Currently, the volume of these wastes is approximately 23,500 m3, and the majority of these wastes (i.e., almost 19,000 m3) consist of PCBs and PCB-contaminated materials. Further, additional PCB-contaminated waste will be generated during D&D operations in the future. The standard process for destruction of this waste is incineration, which generates secondary waste that must be disposed, and the TSCA incinerator at Oak Ridge has an uncertain future. Beyond incineration, no proposed process for the recovery and/or destruction of these persistent pollutants has emerged as the preferred choice for DOE cleanup. The main objective of the project was to investigate and develop a deeper understanding of the thermodynamic and kinetic reactions involved in the extraction and destruction of polychlorinated biphenyls (PCBs) from low-level mixed waste solid matrices in order to provide data that would permit the design of a combined-cycle extraction/destruction process. The specific research objectives were to investigate benign dense-fluid extraction with either carbon dioxide (USC) or hot water (CU), followed by destruction of the extracted PCBs via either electrochemical (USC) or hydrothermal (CU) oxidation. Two key advantages of the process are that it isolates and concentrates the PCBs from the solid matrices (thereby reducing waste volume greatly and removing the remaining low-level mixed waste from TSCA control), and little, if any, secondary solvent or solid wastes are generated. This project was a collaborative effort involving the University of South Carolina (USC), Clemson University (CU), and Westinghouse Savannah River Company (WSRC) (including the Savannah River Technology Center, Facilities Decommissioning Division and Regulatory Compliance). T he project was directed and coordinated by the South Carolina Universities Research ...
Date: December 31, 2001
Creator: Matthews, Michael A.; Bruce,David; Davis,Thomas; Thies, Mark; Weidner, John & White, Ralph
Partner: UNT Libraries Government Documents Department

Rf Gun with High-Current Density Field Emission Cathode

Description: High current-density field emission from an array of carbon nanotubes, with field-emission-transistor control, and with secondary electron channel multiplication in a ceramic facing structure, have been combined in a cold cathode for rf guns and diode guns. Electrodynamic and space-charge flow simulations were conducted to specify the cathode configuration and range of emission current density from the field emission cold cathode. Design of this cathode has been made for installation and testing in an existing S-band 2-1/2 cell rf gun. With emission control and modulation, and with current density in the range of 0.1-1 kA/cm2, this cathode could provide performance and long-life not enjoyed by other currently-available cathodes
Date: December 19, 2005
Creator: Hirshfield, Jay L.
Partner: UNT Libraries Government Documents Department

Topics in gauge theories and the unification of elementary particle interactions

Description: We report on work done by the principal investigators and their collaborators on phenomenology of low and medium p{sub t} physics, standard model results for macroscopic systems, same sign dilepton signals from massive Majorana neutrinos, Casimir effects for charged particles, further macroscopic effects in quantum electrodynamics, and n-particle amplitudes for large n beyond the tree approximation, renormalization group analysis of unified gauge theories.
Date: December 1, 1990
Creator: Srivastava, Y.N. & Vaughn, M.T.
Partner: UNT Libraries Government Documents Department

A detailed study of nonperturbative solutions of two-body Dirac equations

Description: In quark model calculations of the meson spectrums fully covariant two-body Dirac equations dictated by Dirac's relativistic constraint mechanics gave a good fit to the entire meson mass spectrum for light quark mesons as well as heavy quark mesons with constituent world scalar and vector potentials depending on just one or two parameters. In this paper, we investigate the properties of these equations that made them work so well by solving them numerically for quantum electrodynamics (QED) and related field theories. The constraint formalism generates a relativistic quantum mechanics defined by two coupled Dirac equations on a sixteen component wave function which contain Lorentz covariant constituent potentials that are initially undetermined. An exact Pauli reduction leads to a second order relativistic Schroedinger-like equation for a reduced eight component wave function determined by an effective interaction -- the quasipotential. We first determine perturbatively to lowest order the relativistic quasipotential for the Schroedinger-like equation by comparing that form with one derived from the Bethe-Salpeter equation. Insertion of this perturbative information into the minimal interaction structures of the two-body Dirac equations then completely determines their interaction structures. Then we give a procedure for constructing the full sixteen component solution to our coupled first-order Dirac equations from a solution of the second order equation for the reduced wave function. Next, we show that a perturbative treatment of these equations yields the standard spectral results for QED and related interactions.
Date: December 1, 1992
Creator: Crater, H.W.; Becker, R.L.; Wong, C.Y. & Van Alstine, P.
Partner: UNT Libraries Government Documents Department