167 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Thermal Diffusion"  
prev Results: 49 - 72 next
open access

FRACTURED PETROLEUM RESERVOIRS

Description: The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers … more
Date: June 11, 1999
Creator: Firoozabadi, Abbas
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of the influence of thermal discharge from a large electric power station on the temperature and near-shore circulation of Lake Michigan. Quarterly progress report, 1 October 1973--31 December 1973

Description: Progress is reported on studies on nearshore circulation of thermal effluents from the Oak Creek Power Plant, Oak Creek, Wisconsin, in Lake Michigan. Some preliminary data were processed by computer programs to obtain hourly averaged values from ten minute interval values, vector frequency diagrams, and progressive vector diagrams that illustrate the distribution of current meter data according to intervals of speed and direction. (CH)
Date: January 1, 1973
Creator: Mortimer, C. H. & Sato, G. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Rapid cooling and structure of neutron stars

Description: This report discusses the following topics on neutron stars: direct URCA neutrino emission; thermal evolution models; analytic model for diffusion through the crust; and core superfluidity. (LSP).
Date: January 1, 1992
Creator: Van Riper, Kenneth A. & Lattimer, James M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Chemical Properties of Uranium Hexafluoride, UF6

Description: Uranium hexafluoride has the distinction of being the only stable gaseous compound of uranium known up to the present moment. Because of this property it is the only compound that can be used for processes of isotope separation, such as diffusion, thermal diffusion, centrifuge separation, distillation, and other of a similar nature. Here is a short description of the properties of UF{sub 6} and is intended for a reader interested only casually in this compound. UF{sub 6} is a very reactive comp… more
Date: June 25, 1941
Creator: Grosse, Aristid V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Laser-Material Interaction of Powerful Ultrashort Laser Pulses

Description: Laser-material interaction of powerful (up to a terawatt) ultrashort (several picoseconds or shorter) laser pulses and laser-induced effects were investigated theoretically in this dissertation. Since the ultrashort laser pulse (USLP) duration time is much smaller than the characteristic time of the hydrodynamic expansion and thermal diffusion, the interaction occurs at a solid-like material density with most of the light energy absorbed in a thin surface layer. Powerful USLP creates hot, high-… more
Date: January 6, 2003
Creator: Komashko, A
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mass Transfer Coefficients and Interfacial Area in a One Stage Pulse Column

Description: Over-all mass transfer coefficients were determined independently of the interfacial area by considering the operation of the pulse column to be a stage- wise process. The calculated coefficients describe only the operation of the pulse column for the free rise of organic droplets through a stage, since in the downstroke the aqueous phase passes through the organic phase in the form of rivulets preferentially wetting the plates. The driving force for transfer was based on the aqueous phase conc… more
Date: November 1, 1960
Creator: Konopik, A. E. & Burkhart, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 October 1993--31 December 1993

Description: The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. Sophisticated general correlative approaches are slowly being developed, based upon group contribution methods, or based upon some key functional features of the molecules. These are as yet difficult to apply to coal tars. The detailed group contribution methods, in which fairly precise structural information is needed, do no… more
Date: December 31, 1993
Creator: Suuberg, E. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Modeling of heat transfer in a horizontal heat-generating layer by an effective diffusivity approach

Description: The concept of effective diffusivity is employed to model various processes of heat transfer in a volumetrically heated fluid layer subjected to different initial and boundary conditions. The approach, which involves the solution of only heat diffusion equations, is found to give rather accurate predictions of the transient response of an initially stagnant fluid layer to a step input of power as well as the developing and decaying nature of the flow following a step change in the internal Rayl… more
Date: July 1, 1994
Creator: Cheung, F. B.; Shiah, S. W.; Cho, D. H. & Tan, M. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Imaging carrier and phonon transport in Si using ultrashort optical pulses

Description: A series of experiments have been conducted that microscopically image thermal diffusion and surface acoustic phonon propagation within a single crystallite of a polycrystalline Si sample. The experimental approach employs ultrashort optical pulses to generate an electron-hole plasma and a second probe pulse is used to image the evolution of the plasma. By decomposing the signal into a component that varies with delay time and a steady state component that varies with pump modulation frequency,… more
Date: January 1, 2009
Creator: Hurley, David H.; Wright, O. B.; Matsuda, O.; McCandless, B. E. & Shinde, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Anomalous ion thermal diffusion from {eta}{sub i}-modes

Description: Models of ion temperature gradient-driven turbulence are reexamined in terms of the structure of the turbulent spectrum for radially localized modes to explain the significant difference between the radial profiles of ion heat conductivity inferred from local turbulence models and those observed in experiments. The strong radial inhomogeneity of the effective density of the turbulence spectrum in k is shown to produce a significant increase of the fluctuation level and ion thermal diffusion tow… more
Date: December 1, 1991
Creator: Beklemishev, A. D. & Horton, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Energetics of melts from thermal diffusion studies. FY 1996 progress report

Description: This research program characterizes mass transport by diffusion in geological fluids in response to thermal, solubility, and/or chemical gradients to obtain quantitative information on the thermodynamic and kinetic properties of multicomponent systems. Silicate liquids undergo substantial thermal diffusion (Soret) differentiation, while the response in sulfide, carbonate, and aqueous fluids to an imposed temperature gradient is varied. The experimental observations of this differentiation are u… more
Date: December 31, 1997
Creator: Lesher, C.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Energetics of melts from thermal diffusion studies. FY 1995 progress report

Description: This research program characterizes mass transport by diffusion in geological fluids in response to thermal, solubility, and/or chemical gradients to obtain quantitative information on the thermodynamic and kinetic properties of multicomponent systems. Silicate liquids undergo substantial thermal diffusion (Soret) differentiation, while the response in sulfide, carbonate, and aqueous fluids to an imposed temperature gradient is varied. The experimental observations of this differentiation are u… more
Date: December 31, 1996
Creator: Lesher, C.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Modeling of MHD equilibria and current profile evolution during the ERS mode in TFTR

Description: TFTR experiments on the enhanced reversed shear (ERS) mode have demonstrated particle and ion thermal diffusivities in the region of negative shear which are equal to or less than the neoclassical values. Similar enhancements have been observed in reversed central shear discharges in the shaped DIII-D geometry. These results, if sustained over times long compared with current diffusion times, offer the opportunity of an improved reactor. We are modeling the evolution of the TFTR ERS mode using … more
Date: July 18, 1996
Creator: Hooper, E. B.; Pearlstein, L. D. & Bulmer, R. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Dimensionally similar discharges with central rf heating on the DIII-D tokamak

Description: The scaling of L-mode heat transport with normalized gyroradius is investigated on the DIII-D tokamak using central rf heating. A toroidal field scan of dimensionally similar discharges with central ECH and/or fast wave heating show gyro-Bohm-like scaling both globally and locally. The main difference between these restats and those using NBI heating on DIII-D is that with rf heating the deposition profile is not very sensitive to the plasma density. Therefore central heating can be utilized fo… more
Date: April 1, 1993
Creator: Petty, C. C.; Luce, T. C. & Pinsker, R. I.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electrical and thermal modeling of railguns

Description: Electrical and thermal modeling of railguns at Los Alamos has been done for two purposes: (1) to obtain detailed information about the behavior of specific railgun components such as the rails, and (2) to predict overall performance of railgun tests. Detailed electrical and thermal modeling has concentrated on calculations of the inductance and surface current distribution of long parallel conductors in the high-frequency limit and on calculations of current and thermal diffusion in rails. Indu… more
Date: January 1, 1983
Creator: Kerrisk, J.F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Simulations of second-order Fermi acceleration of electrons: Solving the injection problem

Description: The boosting of electrons from a Maxwellian distribution into a suprathermal power-law tail has long been recognized as an important bottleneck governing the subsequent acceleration of some of these electrons to relativistic energies. This is the seed or injection problem. I study this boosting process using a test-particle simulation code, following the full equations of motion of tens of thousands of electrons chosen from a thermal population as they move through general time-dependent magnet… more
Date: December 31, 1991
Creator: Gisler, G. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Study of high gain spherical shell ICF targets containing uniform layers of liquid deuterium tritium fuel. A numericial model for analyzing thermal layering of liquid mixtures of hydrogen isotopes inside a spherical inertial confinement fusion target: Final report

Description: A numerical model has been developed to describe the thermally induced behavior of a liquid layer of hydrogen isotopes inside a spherical Inertial Confinement Fusion (ICF) target and to calculate the far-field temperature gradient which will sustain a uniform liquid layer. This method is much faster than the trial-and-error method previously employed. The governing equations are the equations of continuity, momentum, energy, mass diffusion-convection, and conservation of the individual isotopic… more
Date: May 1, 1994
Creator: Simpson, E. M. & Kim, Kyekyoon
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Nature of the Dissociation Sites of Hydrogen Molecules on Ru(001)

Description: Scanning tunneling microscopy (STM) was used to study the dissociative adsorption of H{sub 2} on Ru(001) near saturation coverage, when the number of residual hydrogen vacancies (i.e., unoccupied Ru sites) is small. We found that H{sub 2} dissociation takes place only on Ru sites where the metal atom is not bound to any H atom. Such active sites are formed when at least 3 H-vacancies aggregate by thermal diffusion. Sites formed by single H-vacancies or pairs of adjoining vacancies were found to… more
Date: March 12, 2008
Creator: Salmeron, Miquel; Rose, Franck; Tartakhanov, Mous; Fomin, Evgeni & Salmeron, Miquel
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Energetics of silicate melts from thermal diffusion studies. Annual progress report

Description: Efforts are reported in the following areas: laboratory equipment (multianvils for high P/T work, pressure media, SERC/DL sychrotron), liquid-state thermal diffusion (silicate liquids, O isotopic fractionation, volatiles, tektites, polymetallic sulfide liquids, carbonate liquids, aqueous sulfate solutions), and liquid-state isothermal diffusion (self-diffusion, basalt-rhyolite interdiffusion, selective contamination, chemical diffusion).
Date: July 1, 1992
Creator: Walker, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen