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Two-phase flow modeling with discrete particles

Description: The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for the calculation of two-phase flows that does not require the use of flow regime maps. This model is intermediate between the intractable local instantaneous and the averaged two-fluid model. This new model uses a combination of an Eulerian and a Lagrangian representation of the two phases. The dispersed particles (bubbles or drops) are modeled individually using a large representative number of particles, each with their own Lagrangian description. The continuous phases (liquid or gas) use an Eulerian description.
Date: March 23, 1992
Creator: Mortensen, G. A. (EG and G Idaho, Inc., Idaho Falls, ID (United States)) & Trapp, J. A. (Colorado Univ., Denver, CO (United States) EG and G Idaho, Inc., Idaho Falls, ID (United States))

Study of improved methods for predicting chemical equilibria

Description: The objective of our research has been to develop computational methods that have the capability of accurately predicting equilibrium constants of typical organic reactions in gas and liquid solution phases. We have chosen Diels-Alder reactions as prototypic systems for the investigation, chiefly because there are an adequate number of reported equilibrium constants for the candidate reactions in both gas and solution phases, which data provides a suitable basis for tests of the developed computational methods. Our approach has been to calculate the standard enthalpies of formation ({Delta}H{sub f}{sup 0}) at 298.15K and the standard thermodynamic functions (S{sup 0}, Cp{sup 0}, and (H{sup 0}-H{sub 0}{sup 0})/T) for a range of temperatures for reactants and products, and from these properties to calculate standard enthalpies, entropies, Gibbs free energies, and equilibrium constants ({Delta}H{sub T}{sup 0}, {Delta}S{sub T}{sup 0}, and K{sub a}) at various temperatures for the chosen reaction.
Date: June 1, 1992
Creator: Lenz, T. G. & Vaughan, J. D.

Staggered fermions and chiral symmetry breaking in transverse lattice regulated QED

Description: Staggered fermions are constructed for the transverse lattice regularization scheme. The weak perturbation theory of transverse lattice non-compact QED is developed in light-cone gauge, and we argue that for fixed lattice spacing this theory is ultraviolet finite, order by order in perturbation theory. However, by calculating the anomalous scaling dimension of the link fields, we find that the interaction Hamiltonian becomes non-renormalizable for g{sup 2}(a) > 4{pi}, where g(a) is the bare (lattice) QED coupling constant. We conjecture that this is the critical point of the chiral symmetry breaking phase transition in QED. Non-perturbative chiral symmetry breaking is then studied in the strong coupling limit. The discrete remnant of chiral symmetry that remains on the lattice is spontaneously broken, and the ground state to lowest order in the strong coupling expansion corresponds to the classical ground state of the two-dimensional spin one-half Heisenberg antiferromagnet.
Date: July 1, 1992
Creator: Griffin, P. A.

Program for implementing software quality metrics

Description: This report describes a program by which the Veterans Benefit Administration (VBA) can implement metrics to measure the performance of automated data systems and demonstrate that they are improving over time. It provides a definition of quality, particularly with regard to software. Requirements for management and staff to achieve a successful metrics program are discussed. It lists the attributes of high-quality software, then describes the metrics or calculations that can be used to measure these attributes in a particular system. Case studies of some successful metrics programs used by business are presented. The report ends with suggestions on which metrics the VBA should use and the order in which they should be implemented.
Date: April 1, 1992
Creator: Yule, H. P. & Riemer, C. A.

Dehumidifying water heater

Description: Drawings and specifications are included for the system to heat water for the swimming pool and dehumidify the building of the Glen Cove YMCA. An overview is presented of the Nautica product used in this system. (MHR)
Date: August 18, 1992

Stratospheric aircraft: Impact on the stratosphere

Description: The steady-state distribution of natural stratospheric ozone is primarily maintained through production by ultraviolet photolysis of molecular oxygen, destruction by a catalytic cycle involving nitrogen oxides (NO{sub x}), and relocation by air motions within the stratosphere. Nitrogen oxides from the exhausts of a commercially viable fleet of supersonic transports would exceed the natural source of stratospheric nitrogen oxides if the t should be equipped with 1990 technology jet engines. This model-free comparison between a vital natural global ingredient and a proposed new industrial product shows that building a large fleet of passenger stratospheric aircraft poses a significant global problem. NASA and aircraft industries have recognized this problem and are studying the redesign of jet aircraft engines in order to reduce the nitrogen oxides emissions. In 1989 atmospheric models identified two other paths by which the ozone destroying effects of stratospheric aircraft might be reduced or eliminated: (1) Use relatively low supersonic Mach numbers and flight altitudes. For a given rate of nitrogen oxides injection into the stratosphere, the calculated reduction of total ozone is a strong function of altitude, and flight altitudes well below 20 kilometers give relatively low calculated ozone reductions. (2) Include heterogeneous chemistry in the two-dimensional model calculations. Necessary conditions for answering the question on the title above are to improve the quality of our understanding of the lower stratosphere and to broaden our knowledge of hetergeneous stratospheric chemistry. This article reviews recently proposed new mechanisms for heterogeneous reactions on the global stratospheric sulfate aerosols.
Date: February 1, 1992
Creator: Johnston, H.

Pyrite surface characterization and control for advanced fine coal desulfurization technologies

Description: The objective of the project is to conduct extensive fundamental studies on the surface reactivity and surface hydrophobicity of coal-pyrites using various surface characterization techniques and to understand how the alteration of the coal-pyrite surface affects the efficiency of pyrite rejection in coal flotation. During this reporting period, the influence of the impurity content, particularly coal/carbon content, on the electrochemical oxidation of pyrite surfaces was investigated. The studies demonstrate that the coal/carbon content in coal-pyrite has a determining effect on the surface reactivity of pyrite. The oxidation behavior of high carbon-content coal-pyrite is completely different from that of purer coal-pyrite and ore-pyrite. The effects of flotation gases on the flotation behavior of coal and the surface hydrophobicity of various coal-pyrite were investigated. It was found from the lab-scale column flotation studies that among the various gases studied (air, oxygen, argon, nitrogen and carbon dioxide), carbon dioxide produced the best results with a combustible recovery of 90% and ash-content of less than 9 percent. Finally, the surface energetic studies revealed that the surfaces of pyrites and coals produced by wet grinding is more heterogenous than that prepared by dry grinding.
Date: January 1, 1992
Creator: Wang, X. H.; Leonard, J. W.; Parekh, B. K.; Raichur, A. M. & Jiang, C. L.

Advanced radioactive waste-glass melters

Description: During pilot scale operations of the Scale Glass Melter for the US Department of Energy a team of engineers and scientists was formed to assess the need for continued melter design development to support the Defense Waste Processing Facility (DWPF), and prioritize future efforts. Recently this has taken on new importance because of selection of the DWPF Melter design as the reference for the Hanford Waste Vitrification Project (HWVP), and increased interest at the West Valley Demonstration Project on melter life and replacement. Results of the study are summarized, and goals produced by the study are compared to the results of current programs at the Savannah River Laboratory (SRL).
Date: January 1, 1990
Creator: Bickford, D. F.

A contemporary guide to beam dynamics

Description: A methodological discussion is given for single particle beam dynamics in circular machines. The discussions are introductory, but (or, even therefore) we avoid to rely on too much simplified concepts. We treat things from a very general and fundamental point of view, because this is the easiest and rightest way to teach how to simulate particle motion and how to analyze its results. We give some principles of particle tracking free from theoretical prejudices. We also introduce some transparent methods to deduce the necessary information from the tracking: many of the traditional beam-dynamics concepts can be abstracted from them as approximate quantities which are valid in certain limiting cases.
Date: September 1, 1992
Creator: Forest, E. (Lawrence Berkeley Lab., CA (United States)) & Hirata, Kohji (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan))

Inhibition of retrogressive reactions in coal/petroleum co-processing

Description: The overall objective of this project is to develop a fundamental understanding of the reactions occurring at the onset of coke formation during the CO-processing of coals with action of chemical components, or groups of components, in coals and petroleum feedstocks to quantify and rank the effects of these components in retarding or enhancement of coke formation. The work involves bench scale reactions in microautoclaves, supplemented by studies of the carbonaceous residues by such techniques as diffuse reflectance Fourier transform infrared spectroscopy and {sup 13}C nuclear magnetic resonance spectrometry.
Date: May 1, 1992
Creator: Schobert, H. H. & Tomic, J.

[Laser flash photolysis, EPR and Raman studies of liquids at elevated pressures]

Description: The proposed research will solve a number of analytical chemical problems in solutions with measurement techniques that benefit from the use of elevated hydrostatic pressures: stopped-flow spectrophotometry (Gd[sup 3+] + L(ligand), [RuL[sub 5]H[sub 2]O][sup 2+], laser flash photolysis of Mo(CO)[sub 6] + L, flash photolysis of binuclear metalloproteins), EPR spectroscopy (Gd[sup 3+] ion-exchanged into ETS-10 and ETAS-10 molecular sieves), laser flash photolysis kinetic studies of Mo(CO)[sub 6]-2,2'-bipyridine, and electrochemical studies of metalloporphyrins using resonance Raman spectroscopy.
Date: January 1, 1992
Creator: Eyring, E. M.

Tritium migration in A/M-Area ground water

Description: Volatile organic compounds (VOC's) have entered aquifers in Cretaceous-aged sediments in the A/M-Area as a result of site operations. Tritium in A/M-Area ground water was investigated as a tracer to determine the movement of ground water in the subsurface and the transport mechanism of VOC's. The investigation was focused primarily on determining the continuity and integrity of the clay layers in the Ellenton Formation and their effectiveness as aquitards below the aquifers in Tertiary sediments.
Date: January 1, 1992
Creator: Strom, R. N. & Kaback, D. S.

Sequential probability ratio tests for reactor signal validation and sensor surveillance applications

Description: This paper examines the properties of sequential probability ratio tests (SPRT's) and the application of these tests to nuclear power reactor operation. Recently SPRT's have been applied to delayed-neutron (DN) signal data analysis using actual reactor data from the Experimental Breeder Reactor-II, which is operated by Argonne National Laboratory. The implementation of this research as part of an expert system is described. Mathematical properties of the SPRT are investigated, and theoretical results are validated with tests that use DN-signal data taken from the EBR-II in Idaho. Variations of the basic SPRT and applications to general signal validation are also explored. 16 refs., 3 figs.
Date: November 9, 1989
Creator: Humenik, K. (Maryland Univ., Baltimore, MD (USA)) & Gross, K. C. (Argonne National Lab., IL (USA))

Automatic differentiation bibliography

Description: This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.
Date: July 1, 1992
Creator: Corliss, G. F. (comp.)

Bose condensate in superfluid sup 4 He and momentum distributions by deep inelastic scattering

Description: There are several reasons for the high interest in the recent experimental and theoretical progress in understanding deep inelastic neutron scattering from liquid {sup 4}He: it tests the fundamental London hypothesis of a connection between superfluidity and Bose condensation; it provides a quantitative test of ab-initio calculational methods for all systems with strong correlations which are the focus of current quantum many-body research; and it establishes the range of validity of deep inelastic scattering as a method for measuring momentum distributions. In this paper we introduce the concepts of impulse approximation in more detail, we describe recent progress in the theory for final state corrections to the impulse approximation, we present quantitative predictions for neutron scattering experiments, we compare with recent high energy pulsed neutron source experiments on liquid {sup 4}He by P. Sokol and colleagues as well as other attempts to extract the Bose condensate fraction from the neutron scattering data, and we discuss the implications of this progress for future momentum distribution experiments in other systems such as liquid {sup 3}He and quasi-elastic electron nucleus scattering. 42 refs., 23 figs.
Date: January 1, 1989
Creator: Silver, R. N. (Los Alamos National Lab., NM (USA)) & Sokol, P. E. (Pennsylvania State Univ., University Park, PA (USA). Dept. of Physics)

Synchrotron radiation sources and condensers for projection x-ray lithography

Description: The design requirements for a compact electron storage ring that could be used as a soft x-ray source for projection lithography are discussed. The design concepts of the x-ray optics that are required to collect and condition the radiation in divergence, uniformity and direction to properly illuminate the mask and the particular x-ray projection camera used are discussed. Preliminary designs for an entire soft x-ray projection lithography system using an electron storage ring as a soft X-ray source are presented. It is shown that by combining the existing technology of storage rings with large collection angle condensers, a powerful and reliable source of 130[Angstrom] photons for production line projection x-ray lithography is possible.
Date: January 1, 1992
Creator: Murphy, J. B.; MacDowell, A. A. (Brookhaven National Lab., Upton, NY (United States)); White, D. L. (AT and T Bell Labs., Murray Hill, NJ (United States)) & Wood, O. R. II (AT and T Bell Labs., Holmdel, NJ (United States))

Reactions during the processing of U sub 3 O sub 8 -Al cermet fuels

Description: The cermet fuel (U{sub 3}O{sub 8} dispersed in Al) being considered for use in the Savannah River Site reactors is thermodynamically unstable due to the potential for a metallothermic reduction reaction. The exothermic reaction between U{sub 3}O{sub 8} and Al produces approximately 225 calories of heat for every gram of oxide consumed. During processing of the U{sub 3}O{sub 8}-Al cermet fuels by Powder Metallurgy (P/M) techniques, a significant portion of the U{sub 3}O{sub 8} is reduced to U{sub 4}O{sub 9}. The reaction between U{sub 4}O{sub 9} and Al is also exothermic, however, the maximum heat released by the reaction is approximately 80 calories per gram of oxide reacted. Metallothermic reduction reactions for U{sub 3}O{sub 8}/U{sub 4}O{sub 9}/Al mixtures do not occur at the normal reactor operating temperature ({approximately}100{degrees}C) or at temperatures below the melting point of aluminum (660{degrees}C). This report describes work performed to quantify the extent of reaction during P/M processing of the U{sub 3}O{sub 8}-Al cermet fuel, and to determine the effect of reduction to U{sub 4}O{sub 9} on the metallothermic reduction reaction.
Date: January 1, 1990
Creator: Marra, J. E. & Peacock, H. B.

Selective flotation of fossil resin from western coal

Description: The test program has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process. The proof-of-concept testing has resulted in significant interest from several coal mining companies and has sparked the desire of local and state government to establish a fossil resin industry in the Wasatch Plateau coal field. In this view, the results from the current proof-of-concept testing program have been successful. This special report provides theoretical and analytical data on some surface chemistry work pertinent to fossil resin characterization, and other efforts carried out during the past months.
Date: March 20, 1992
Creator: Jensen, G. F. & Miller, J. D.

Preliminary study of AC power feeders for AGS booster

Description: It has been proposed that the AGS Heavy Ion/Proton Booster be excited directly from the electric power distribution system without intervening an energy storage buffer such as an MG set or a magnetic energy buffer. The average power requirement of the AGS Booster is less than many single-loads presently housed on the lab site. However, the power swing will be the largest single pulsating load on the lab site. The large power swings will impact on the power grid producing utility-line disturbances such as voltage fluctuations and harmonic generation. Thus, it is necessary to carefully evaluate the quality of the electric power system resulting from the interconnection, such that the utility system is not degraded either on the lab site or at LILCO's substation.
Date: July 17, 1992
Creator: Meth, M.

A quasi-optical electron cyclotron maser for fusion reactor heating

Description: High power microwave and millimeter sources, such as the quasi-optical electron cyclotron maser (QOECM) are important in fusion research as well as in high-energy physics and in other applications. The interaction between the electromagnetic modes of a Fabry-Perot resonator and an electron beam gyrating through a magnetic field has been studied for both the cases of beams parallel and perpendicular to the resonator. The parallel case was theoretically first studied by Kurin for forward and backward wave interaction, and experimentally by Komlev and Kurin. Kreischer and Temkin reviewed the general case of the linear small signal interaction parallel and perpendicular to the resonator. Sprangle, et al discussed the perpendicular case in a self-consistent linear and nonlinear theoretical study using the Gaussian transverse profile of an open resonator with a single longitudinal mode. Experimental verification of the devices operation was first mentioned in work at the Naval Research Laboratory. Theoretical studies using a time-dependent analysis of a large number of longitudinal modes with similar transverse mode profiles have demonstrated that single longitudinal-mode operation can be achieved at equilibrium and that performance can be enhanced by prebunching the electron beam and tapering the magnetic field. The use of output coupling apertures in the mirrors has been studied theoretically in relation to the structure of the modes for both confocal and nonconfocal resonators by Permnoud; use of an open resonator with stepped mirrors has been studied in order to choose a particular longitudinal mode. Studies at the Naval Research Laboratory mirror used configurations that diffraction couple the energy from around the mirror edges, so that the transverse profile inside the resonator can be selective to the fundamental mode.
Date: January 1, 1990
Creator: Morse, E. C.

Savannah River Site Geographic Information System management plan

Description: A plan for managing the development of Geographic Information System (GIS) applications at the Savannah River Site (SRS) in a coordinated, integrated fashion has been developed. Included in the plan are discussions on the guidance for GIS activities at the site, the overall strategy for managing GIS applications development, the specific administrative and programmatic tasks with projected completion schedules, and the organizational structure in place to direct this GIS effort. The Department of Energy-Savannah River Field Office (DOE-SR) has encouraged all primary subcontracting organizations at SRS involved with the mapping of spatial data to coordinate their efforts and be more cost effective. This plan provides a description of organized activities in 1992 for establishing a coordinated approach for developing and implementing GIS technology.
Date: February 1, 1992
Creator: Gordon, D. E.

Isotopic tailoring with sup 59 Ni to study the effect of helium on microstructural evolution and mechanical properties of neutron-irradiated Fe-Cr-Ni alloys

Description: Tensile testing on three model Fe-Cr-Ni alloys removed from four discharges of the {sub 59}Ni isotopic doping experiment in FFTF-MOTA indicates that helium/dpa ratios typical of fusion reactors do not produce changes in the yield strength or elongation that are significantly different from those at much lower helium generation rates. It also appears that tensile properties approach a saturation level that is dependent only on the final irradiation temperature, but not prior temperature history or thermomechanical starting condition. The saturation in mechanical properties reflects a similar saturation in microstructure that is independent of starting condition. The successful conduct of an isotopic doping experiment was found to require post-irradiation measurement of the helium levels in order to compensate for uncertainties in the cross sections for burn-out and burn-in of {sub 59}Ni and for uncertainties in neutron flux and spectra in the vicinity of the edge of the core.
Date: March 1, 1992
Creator: Garner, F. A.; Hamilton, M. L.; Greenwood, L. R. (Pacific Northwest Lab., Richland, WA (United States)); Stubbins, J. F. (Illinois Univ., Urbana, IL (United States)) & Oliver, B. M. (Rockwell International Corp., Canoga Park, CA (United States))