1,919 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Mathematical Models"  
Results: 1 - 24 next
open access

Two exercises in supersymmetry: a low-energy supergravity model and free string field theory

Description: The new features of a supersymmetric standard model in the presence of heavy families are studied. The minimal set of Higgs fields, the desert between the electroweak and the grand unification scale and perturbative values of the dimensionless parameters throughout this region are assumed. Using the numerical as well as the approximate analytic solution of the renormalization group equations, the evolution of all the parameters of the theory are studied in the case of large Yukawa couplings for… more
Date: September 1, 1986
Creator: Preitschopf, C.R.
Partner: UNT Libraries Government Documents Department
open access

HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report

Description: Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In th… more
Date: September 1, 1982
Creator: Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W et al.
Partner: UNT Libraries Government Documents Department
open access

Electronic band structure and optical properties of the cubic, Sc, Y and La hydride systems

Description: Electronic band structure calculations are used to interpret the optical spectra of the cubic Sc, Y and La hydride systems. Self-consistent band calculations of ScH/sub 2/ and YH/sub 2/ were carried out. The respective joint densities of states are computed and compared to the dielectric functions determined from the optical measurements. Additional calculations were performed in which the Fermi level or band gap energies are rigidly shifted by a small energy increment. These calculations are t… more
Date: January 1, 1980
Creator: Peterman, D. J.
Partner: UNT Libraries Government Documents Department
open access

SPXCPL: two-dimensional modeling program of self-potential effects from cross-coupled fluid and heat flow (User's Guide and documentation for Version 1. 0)

Description: The program is applicable to the calculation of self-potential effects due to fluid flow (electrokinetic effects) and heat flow (thermoelectric effects). The geological structure is two dimensional but the sources can be either finite line sources or point sources. The accuracy of the calculated potentials depends on the model discretization and the distance from the source(s). For the default mesh, the accuracy is usually a few percent at a distance of about one unit from the source. Surface b… more
Date: March 1, 1982
Creator: Sill, W. R. & Killpack, T. J.
Partner: UNT Libraries Government Documents Department
open access

Boundary element formulation for planar time-dependent inelastic deformation of plates with cutouts

Description: A boundary element formulation for planar, time-dependent, inelastic deformation problems for bodies with cutouts is presented in this paper. A stress function description for these nonlinear problems leads to a nonhomogeneous biharmonic equation for the stress function rate. An integral representation of the solution uses modified kernels which guarantee that the cutout boundary is traction free for all time. This incorporation of the effect of the cutout on the stress field into the kernels l… more
Date: February 1, 1980
Creator: Mukherjee, S. & Morjaria, M.
Partner: UNT Libraries Government Documents Department
open access

Assessment of the risk of transporting liquid chlorine by rail

Description: This report presents the risk of shipping liquid chlorine by rail. While chlorine is not an energy material, there are several benefits to studying chlorine transportation risks. First, chlorine, like energy materials, is widely used as a feedstock to industry. Second, it is the major purification agent in municipal water treatment systems and therefore, provides direct benefits to the public. Finally, other risk assessments have been completed for liquid chlorine shipments in the US and Europe… more
Date: March 1, 1980
Creator: Andrews, W.B.
Partner: UNT Libraries Government Documents Department
open access

Final Report of Modeling of CWM Droplet Combustion

Description: The objective of the present study was to develop a one-dimensional, unsteady state model for coal-water mixture droplet combustion, and to compare the characteristic times for the various processes, such as water vaporization, devolatilization and char oxidation with available experimental data. A water film surrounding a spherical coal particle is considered to undergo vaporization by heat transfer from the hot air. After the water vaporization is complete, devolatilization begins. This proce… more
Date: October 1, 1983
Creator: Pandalai, Krish; Aggarwal, Suresh & Sirignano, William
Partner: UNT Libraries Government Documents Department
open access

Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. A report on Tasks 1 and 2 of Phase I. [Shallow land burial]

Description: The purpose of the work reported here was to evaluate the relevance of biotic transport to the assessment of impacts and licensing of low-level waste disposal sites. Available computer models and their recent applications at low-level waste disposal sites are considered. Biotic transport mechanisms and processes for both terrestrial and aquatic systems are presented with examples from existing waste disposal sites. Following a proposed system for ranking radionuclides by their potential for bio… more
Date: July 1, 1982
Creator: McKenzie, D. H.; Cadwell, L. L.; Cushing, C. E. Jr.; Harty, R.; Kennedy, W. E. Jr.; Simmons, M. A. et al.
Partner: UNT Libraries Government Documents Department
open access

Energy Program annual report

Description: The national economy is particularly dependent on efficient electrical generation and transportation. Electrical demand continues to grow and will increasingly rely on coal and nuclear fuels. The nuclear power industry still has not found a solution to the problem of disposing of the waste produced by nuclear reactors. Although coal is in ample supply and the infrastructure is in place for its utilization, environmental problems and improved conversion processes remain technical challenges. In … more
Date: February 1, 1988
Creator: Borg, I.Y. (ed.)
Partner: UNT Libraries Government Documents Department
open access

The collaborative program of research in engineering sciences

Description: Research programs in the following areas are briefly described: High-Temperature Gas-Particle Reactions; Mathematical Modelling of Plasma Systems; Metal Transfer in Gas Metal-Arc Welding; Multivariable Control of Gas Metal-Arc Welding; Synthesis of Heat and Work Integration Systems for Chemical Process Plants; Parity Simulation of Dynamic Processes; Fundamentals of Elastic-Plastic Fracture: Three-Dimensional and Mechanistic Modelling; and Comminution of Energy Materials. Publications from each … more
Date: August 1, 1989
Creator: White, D.C.
Partner: UNT Libraries Government Documents Department
open access

COBRA-WC: a version of COBRA for single-phase multiassembly thermal hydraulic transient analysis. [LMFBR]

Description: The objective of this report is to provide the user of the COBRA-WC (Whole Core) code a basic understanding of the code operation and capabilities. Included in this manual are the equations solved and the assumptions made in their derivations, a general description of the code capabilities, an explanation of the numerical algorithms used to solve the equations, and input instructions for using the code. Also, the auxiliary programs GEOM and SPECSET are described and input instructions for each … more
Date: July 1, 1980
Creator: George, T. L.; Basehore, K. L.; Wheeler, C. L.; Prather, W. A. & Masterson, R. E.
Partner: UNT Libraries Government Documents Department
open access

Successive collision calculation of resonance absorption

Description: The successive collision method for calculating resonance absorption solves numerically the neutron slowing down problem in reactor lattices. A discrete energy mesh is used with cross sections taken from a Monte Carlo library. The major physical approximations used are isotropic scattering in both the laboratory and center-of-mass systems. This procedure is intended for day-to-day analysis calculations and has been incorporated into the current version of MUFT. The calculational model used for … more
Date: July 1, 1980
Creator: Schmidt, E. & Eisenhart, L.D.
Partner: UNT Libraries Government Documents Department
open access

Analytical model for a vertical buoyant jet

Description: An analytical model for a round and two-dimensional turbulent buoyant jet which is discharged vertically into a stagnant ambient is developed. The buoyant jet is considered to have three separate zone models which are matched to form a complete solution. The velocity field is determined for the entire jet and plume regions by the use of an eddy viscosity which varies along the axis of the jet. The centerline decay of buoyancy is determined throughout and the results are compared to existing num… more
Date: October 1, 1980
Creator: Lee, D. W.
Partner: UNT Libraries Government Documents Department
open access

Toroidal plasma equilibrium with gravity

Description: Toroidal magnetic field configuration in a gravitational field is calculated both from a simple force-balance and from the calculation using magnetic surfaces. The configuration is found which is positionally stable in a star. The vibrational frequency near the equilibrium point is proportional to the hydrostatic frequency of a star multiplied by the ratio (W/sub B//W/sub M/)/sup 1/2/ where W/sub B/ is the magnetic field energy density, and W/sub M/ is the material pressure at the equilibrium p… more
Date: September 1, 1980
Creator: Yoshikawa, S.
Partner: UNT Libraries Government Documents Department
open access

Development of a procedure to estimate runoff and sediment transport in ephemeral streams

Description: A distributed hydrologic model for application on small, semiarid watersheds is developed. The distributed model incorporates simplified routing schemes to include the influence of transmission losses on runoff. A sediment transport model, by sediment size fractions, is developed to compute transport capacity and sediment yield in noncohesive, alluvial channels. Based on available information published in soils and topographic maps and on channel and bed sediment characteristics, the procedure … more
Date: January 1, 1982
Creator: Lane, L.J.
Partner: UNT Libraries Government Documents Department
open access

FEMWATER: a finite-element model of water flow through saturated-unsaturated porous media

Description: Upon examining the Water Movement Through Saturated-Unsaturated Porous Media: A Finite-Element Galerkin Model, it was felt that the model should be modified and expanded. The modification is made in calculating the flow field in a manner consistent with the finite element approach, in evaluating the moisture-content increasing rate within the region of interest, and in numerically computing the nonlinear terms. With these modifications, the flow field is continuous everywhere in the flow regime… more
Date: October 1, 1980
Creator: Yeh, G.T. & Ward, D.S.
Partner: UNT Libraries Government Documents Department
open access

Assessment of the theory and hypotheses of the acidification of watersheds

Description: This report documents and critically assesses the evolution and status of the scientific understanding of the effects of acidic deposition on surface waters. The main conclusion is that the dominant theory of surface-water acidification fails to adequately incorporate many important factors and processes that influence surface water acidity. Some of these factors and processes are not well researched or recognized as being important by most scientists in the aquatic effects research area. 258 r… more
Date: April 1, 1989
Creator: Krug, E.C.
Partner: UNT Libraries Government Documents Department
open access

One-dimensional code to predict the thermal behavior of the UTSI MHD radiant furnace

Description: An analytical model of the thermal behavior of the radiant furnace components installed in the CFFF has been developed. Efforts have been primarily directed towards obtaining a representative global evaluation of the heat recovery of the major downstream components. An overall review of the heat transfer code developed specifically for the DOE CFFF downstream components is presented. The basic methods by which the gas state, transport properties, and the thermal radiative and convective propert… more
Date: March 1, 1984
Creator: Galanga, F.L.
Partner: UNT Libraries Government Documents Department
open access

The solar flare of 18 August 1979: Incoherent scatter radar data and photochemical model comparisons

Description: Measurements of electron density at seven D-region altidues were made with the Arecibo radar during a Class-X solar flare on 18 August 1979. Measurements of solar x-ray fluxes during the same period were available from the GOES-2 satellite (0.5 to 4 /angstrom/ and 1 to 8 /angstrom/) and from ISEE-3 (in four bands between 26 and 400 keV). From the x-ray flux data we computed ionization rates in the D-region and the associated chemical changes, using a coupled atmospheric chemistry and diffusion … more
Date: April 1, 1988
Creator: Zinn, J.; Sutherland, C. D.; Fenimore, E. E. & Ganguly, S.
Partner: UNT Libraries Government Documents Department
open access

Delineation of an electrical resistivity anomaly, Malpais area, Beowawe KGRA, Eureka and Lander Counties, Nevada

Description: A simple numerical model of previously released bipole-dipole resistivity data shows the margin of the graben to be anomalously conductive below the Malpais. The conductive area has been delineated with data from a dipole-dipole resistivity survey run in April 1980 for this study. Detailed numerical models of these data define a 1250 m wide body with resistivities less than 20 ohm-m that appear to connect The Geysers and the graben boundary. The minimum depth to the conductor is interpreted to … more
Date: July 1, 1980
Creator: Smith, C.
Partner: UNT Libraries Government Documents Department
open access

Analytical theory of ion-temperature-gradient instability

Description: The relationship between the threshold values of ion-temperature-gradient instabilities and the temperature parameters of plasmas is investigated analytically in slab and toroidal geometries separately. It is found that the threshold values increase rapidly when the ion temperature becomes much higher than the electron temperature. The change of the threshold vaues with respect to the ion temperature is quite similar for both geometric models. This finding is consistent with PLT observations. F… more
Date: January 19, 1982
Creator: Guo, S.; Shen, J.; Chen, L. & Tsai, S.T.
Partner: UNT Libraries Government Documents Department
open access

Treatment of dynamical processes in two-dimensional models of the troposphere and stratosphere

Description: The physical structure of the troposphere and stratosphere is the result of an intricate interplay among a large number of radiative, chemical, and dynamical processes. Because it is not possible to model the global environment in the laboratory, theoretical models must be relied on, subject to observational verification, to simulate atmospheric processes. Of particular concern in recent years has been the modeling of those processes affecting the structure of ozone and other trace species in t… more
Date: July 1, 1980
Creator: Wuebbles, D.J.
Partner: UNT Libraries Government Documents Department
open access

An analysis of residential energy consumption in a temperate climate

Description: Electrical energy consumption data have been recorded for several hundred submetered residential structures in Middle Tennessee. All houses were constructed with a common energy package.'' Specifically, daily cooling usage data have been collected for 130 houses for the 1985 and 1986 cooling seasons, and monthly heating usage data for 186 houses have been recorded by occupant participation over a seven-year period. Cooling data have been analyzed using an SPSSx multiple regression analysis and … more
Date: June 1, 1987
Creator: Clark, Y.Y. & Vincent, W.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen