408 Matching Results

Search Results

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

Second-law efficiency of solar-thermal cavity receivers

Description: Properly quantified performance of a solar-thermal cavity receiver must not only account for the energy gains and losses as dictated by the First Law of thermodynamics, but it must also account for the quality of that energy. However, energy quality can only be determined from the Second Law. In this paper an equation for the Second-Law efficiency of a cavity receiver is derived from the definition of available energy or availability (occassionally called exergy), which is a thermodynamic prope… more
Date: October 1, 1983
Creator: Moynihan, P. I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Two studies of nonlinear processes in irreversible thermodynamics

Description: The investigation dealt with two lines of research into two well-defined problems of engineering science: a study of two-phase flow and of nonelastic deformations in structural solids. Both topics fall into the broad field of nonlinear irreversible processes. The study of two-phase flow resulted in a complete topological analysis of the canonical mathematical model of one-dimensional flow of a mixture of two phases, now predominantly used in industry, especially the nuclear industry. The topolo… more
Date: January 1, 1992
Creator: Kestin, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Two bismuth sulfate-sulfuric acid hybrid water-splitting cycles. Proposed antimonyl sulfate cycle

Description: Some experimental work is presented that is related to two hybrid thermochemical cycles for the production of hydrogen which involve bismuth trisulfate and/or bismuth oxysulfates. Omitting statement of the steps for decomposition of SO/sub 3/ and the electrochemical formation of H/sub 2/ and H/sub 2/SO/sub 4/ from SO/sub 2/ and H/sub 2/O, the high and low temperature reactions are: Cycle I - Bi/sub 2/(SO/sub 4/)/sub 3/ = Bi/sub 2/O/sub 2/ /sub 3/ (SO/sub 4/)/sub 0/ /sub 7/ + 2.3 SO/sub 3/; and … more
Date: January 1, 1982
Creator: Jones, W.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Von Neumann stability of the WONDY wavecode for thermodynamic equations of state

Description: Previous analyses of the von Neumann stability of the WONDY wavecode (based on the von Neumann--Richtmyer artificial viscosity method) assumed a mechanical stress--strain relation; i.e., they assumed the stress, p, to depend only on the mass density, rho. In a thermodynamic equation of state p is allowed to depend also on the specific entropy, S (or on the specific internal energy, epsilon). If p does not depend on epsilon (or S), then the Grueneisen parameter, GAMMA, is zero. Herein a von Neum… more
Date: November 1, 1977
Creator: Hicks, D.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Prediction of the entropy production and pressure losses in two-phase flow from the mixing length theory

Description: The case of vertical two-phase flow is examined under the light of the mixing-length theory which was succesfully applied to turbulent flows. The purpose of the analysis is to obtain the pressure distribution along the geothermal wells. The well is modeled as a vertical pipe carrying a fluid of variable density; the density distribution is described by two parameters. The conservation equations are written in boundary layer coordinates and the pressure losses are computed through the entropy pr… more
Date: April 1, 1980
Creator: Maeder, P. F. & Michaelides, E. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The thermodynamic properties of 2-methylaniline and trans-(R,S)- decahydroquinoline

Description: Measurements leading to the calculation of the ideal-gas thermodynamic properties for 2-methylaniline and trans-(R,S)-decahydroquinoline are reported. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (dsc). Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas at selected temperatures for both compounds. Critical properties we… more
Date: February 1, 1990
Creator: Steele, W. V.; Chirico, R. D.; Nguyen, A. & Knipmeyer, S. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Models for geothermal wells

Description: The problem of two-phase flow pressure loss is examined in order to give an answer to the problem of determination of the wellhead conditions. For this purpose two models have been developed, the first based on the pattern structure of the flow and the second on the mixing length theory. The void fraction correlations and the transition conditions are presented in the first model as a means of estimating the pressure loss. Heat losses, and the effect of impurities are examined in detail. An exp… more
Date: June 1, 1980
Creator: Michaelides, E.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The thermodynamic properties of benzothiazole and benzoxazole

Description: This research program, funded by the Department of Energy, Office of Fossil Energy, Advanced Extraction and Process Technology, provides accurate experimental thermochemical and thermophysical properties for key'' organic diheteroatom-containing compounds present in heavy petroleum feedstocks, and applies the experimental information to thermodynamic analyses of key hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation reaction networks. Thermodynamic analyses, based on accurate in… more
Date: August 1, 1991
Creator: Steele, W. V.; Chirico, R. D.; Knipmeyer, S. E. & Nguyen, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Pigment-protein complexes

Description: The photosynthetically-active pigment protein complexes of procaryotes and eucaryotes include chlorophyll proteins, carotenochlorophyll proteins, and biliproteins. They are either integral components or attached to photosynthetic membranes. Detergents are frequently required to solubilize the pigment-protein complexes. The membrane localization and detergent solubilization strongly suggest that the pigment-protein complexes are bound to the membranes by hydrophobic interactions. Hydrophobic int… more
Date: January 1, 1980
Creator: Siegelman, H W
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Parametric Study of Certain Low-Molecular-Weight Compounds as Nuclear Rocket Propellants. v. Methane

Description: A parametric investigation was made of a series of lowmolecular-weight, high-hydrogen-content compounds as propellants for nuclear-powered rockets. The chemical compounds include H/sub 2/, NH/sub 3/, H/sub 2/0, LiH, CH/sub 4/, and CH/ sub 3/OH. A two-part computational program was carried out for each compound; the results for methane are presented in both tabular and graphic form. The results of the first part of the program are presented in static form, that is, by the conventional Mollier di… more
Date: August 1, 1961
Creator: Krieger, F.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Maximum entropy beam diagnostic tomography

Description: This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs.
Date: January 1, 1985
Creator: Mottershead, C.T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Computer codes used in the calculation of high-temperature thermodynamic properties of sodium

Description: Three computer codes - SODIPROP, NAVAPOR, and NASUPER - were written in order to calculate a self-consistent set of thermodynamic properties for saturated, subcooled, and superheated sodium. These calculations incorporate new critical parameters (temperature, pressure, and density) and recently derived single equations for enthalpy and vapor pressure. The following thermodynamic properties have been calculated in these codes: enthalpy, heat capacity, entropy, vapor pressure, heat of vaporizatio… more
Date: December 1, 1979
Creator: Fink, J.K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Thermodynamic properties of pure and saline (geothermal) water

Description: In order to evaluate the performance of proposed processes utilizing geothermal energy, it is essential to determine the thermodynamic properties of fluid streams at various points in the system. The method described ascertains the values of these properties for either pure water or salt solution, correlating temperature, pressure, enthalpy, and entropy in the liquid, two-phase, and vapor regions. The corresponding FORTRAN computer formulation is coded in one subroutine and twenty-six function … more
Date: January 1, 1980
Creator: Packer, M.B.; Mikic, B.B.; Meal, H.C. & Guillamon-Duch, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Antimatter clusters from hadronizing quark-gluon plasma

Description: A realistic model is used for the phase transition between the color deconfining quark-gluon plasma phase and the color confining hadronic gas phase of nuclear matter to discuss the question how quarks and antiquarks hadronize in an expanding quark-gluon plasma. Particular attention is given to the problem associated with the latent heat and latent entropy set free in the hadronization process. Assuming a specific space-time scenario for the phase transition, relative abundances are computed fo… more
Date: January 1, 1986
Creator: Heinz, U.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Current puzzles and future possibilities

Description: Four current puzzles and several future experimental possibilities in high-energy nuclear collision research are discussed. These puzzles are (1) entropy, (2) hydrodynamic flow, (3) anomalon, and (4) particle emission at backward angles in proton-nucleus collisions. The last one seems not to be directly related to the subject of the present school. But it is, because particle emission into the region far beyond the nucleon-nucleon kinematical limit is an interesting subject common for both prot… more
Date: February 1, 1982
Creator: Nagamiya, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Thermodynamic and kinetic aspects of surface acidity

Description: Our research in the general area of acid catalysis involves the characterization of solid acidity and the corresponding assessment of catalytic performance of acidic materials. Acid characterization studies are required to provide essential information about the type of acid site (i.e., Lewis versus Bronsted), the strength of the sites, and the mobility of molecules adsorbed on the acid sites. An accurate measure of acid strength is given by the heat of adsorption of a basic probe molecule on t… more
Date: January 1, 1992
Creator: Dumesic, J.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Shock waves, increase of entropy and loss of information

Description: We discuss, for the simplified model of a single conservation law, the concepts of genuine nonlinearity, breakdown of classical solutions, solutions in the distribution sense and their nonuniqueness, the viscosity method, finite difference methods, and the shock condition. We then discuss, for the scalar model, the compactness of solutions constructed by the viscosity and difference methods, and derive the entropy inequality for such solutions. We derive Glimm's estimate for the total variation… more
Date: October 1, 1984
Creator: Lax, P.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Dynamical properties from quantum Monte Carlo by the Maximum Entropy Method

Description: An outstanding problem in the simulation of condensed matter phenomena is how to obtain dynamical information. We consider the numerical analytic continuation of imaginary time Quantum Monte Carlo data to obtain real frequency spectral functions. We suggest an image reconstruction approach which has been widely applied to data analysis in experimental research, the Maximum Entropy Method (MaxEnt). We report encouraging preliminary results for the Fano-Anderson model of an impurity state in a co… more
Date: January 1, 1989
Creator: Silver, R. N.; Sivia, D. S. & Gubernatis, J. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Reactor potential of the Magnetically Insulated Inertial Confinement Fusion (MICF) system

Description: In this paper a quasi one dimensional, time dependent set of particle and energy balance equations for the thermal species, namely, electrons, ions and thermal alphas which also allows for an appropriate set of fast alpha groups is utilized to assess the reactor prospects of a DT-burning Magnetically Insulated Inertial Confinement Fusion (MICF) system. A reference reactor consisting of an initial plasma with density of 10/sup 21/ cm/sup -3/, temperature of keV, a radius of 0.25 cm is shown to i… more
Date: January 1, 1987
Creator: Kammash, T. & Galbraith, D.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Algorithmic randomness, physical entropy, measurements, and the second law

Description: Algorithmic information content is equal to the size -- in the number of bits -- of the shortest program for a universal Turing machine which can reproduce a state of a physical system. In contrast to the statistical Boltzmann-Gibbs-Shannon entropy, which measures ignorance, the algorithmic information content is a measure of the available information. It is defined without a recourse to probabilities and can be regarded as a measure of randomness of a definite microstate. I suggest that the ph… more
Date: January 1, 1989
Creator: Zurek, W.H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Methods of Obtaining Thermodynamic Data

Description: The types of thermodynamic data needed to predict behavior of high temperature systems such as an overheated nuclear reactor in which the fuel has been exposed to water and oxygen are discussed. Procedures for obtaining the needed data are reviewed. 14 refs.
Date: October 1, 1987
Creator: Brewer, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen