Thermodynamic properties of cryogenic fluids
Leachman, Jacob; Lemmon, Eric; Penoncello, Steven
2017-01-01
This update to a classic reference text provides practising engineers and scientists with accurate thermophysical property data for cryogenic fluids. The equations for fifteen important cryogenic fluids are presented in a basic format, accompanied by pressure-enthalpy and temperature-entropy charts and tables of thermodynamic properties. It begins with a chapter introducing the thermodynamic relations and functional forms for equations of state, and goes on to describe the requirements for thermodynamic property formulations, needed for the complete definition of the thermodynamic properties of a fluid. The core of the book comprises extensive data tables and charts for the most commonly-encountered cryogenic fluids. This new edition sees significant updates to the data presented for air, argon, carbon monoxide, deuterium, ethane, helium, hydrogen, krypton, nitrogen and xenon. The book supports and complements NIST’s REFPROP - an interactive database and tool for the calculation of thermodynamic propertie...
Computing Thermodynamic And Transport Properties
Mcbride, B.; Gordon, Sanford
1993-01-01
CET89 calculates compositions in chemical equilibrium and properties of mixtures of any chemical system for which thermodynamic data available. Provides following options: obtains chemical-equilibrium compositions and corresponding thermodynamic mixture properties for assigned thermodynamic states; calculates dilute-gas transport properties of complex chemical mixtures; obtains Chapman-Jouguet detonation properties for gaseous mixtures; calculates properties of incident and reflected shocks in terms of assigned velocities; and calculates theoretical performance of rocket for both equilibrium and frozen compositions during expansion. Rocket performance based on optional models of finite or infinite area combustor.
Thermodynamic properties of sea air
Directory of Open Access Journals (Sweden)
R. Feistel
2010-02-01
Full Text Available Very accurate thermodynamic potential functions are available for fluid water, ice, seawater and humid air covering wide ranges of temperature and pressure conditions. They permit the consistent computation of all equilibrium properties as, for example, required for coupled atmosphere-ocean models or the analysis of observational or experimental data. With the exception of humid air, these potential functions are already formulated as international standards released by the International Association for the Properties of Water and Steam (IAPWS, and have been adopted in 2009 for oceanography by IOC/UNESCO.
In this paper, we derive a collection of formulas for important quantities expressed in terms of the thermodynamic potentials, valid for typical phase transitions and composite systems of humid air and water/ice/seawater. Particular attention is given to equilibria between seawater and humid air, referred to as "sea air" here. In a related initiative, these formulas will soon be implemented in a source-code library for easy practical use. The library is primarily aimed at oceanographic applications but will be relevant to air-sea interaction and meteorology as well.
The formulas provided are valid for any consistent set of suitable thermodynamic potential functions. Here we adopt potential functions from previous publications in which they are constructed from theoretical laws and empirical data; they are briefly summarized in the appendix. The formulas make use of the full accuracy of these thermodynamic potentials, without additional approximations or empirical coefficients. They are expressed in the temperature scale ITS-90 and the 2008 Reference-Composition Salinity Scale.
THERRP: a thermodynamic properties program
Energy Technology Data Exchange (ETDEWEB)
Deeds, R.S.
1977-05-01
The computer program THERPP, a program that calculates the thermodynamic properties of light hydrocarbons and mixtures of light hydrocarbons is documented. A specific pressure--temperature or pressure--enthalpy grid is input to obtain properties in the desired region. THERPP is a modification of the program HSGC. Thermodynamic properties are calculated using Starling's modification to the Benedict-Webb-Rubin equation of state.
Advanced working fluids: Thermodynamic properties
Lee, Lloyd L.; Gering, Kevin L.
1990-10-01
Electrolytes are used as working fluids in gas fired heat pump chiller engine cycles. To find out which molecular parameters of the electrolytes impact on cycle performance, a molecular theory is developed for calculating solution properties, enthalpies, vapor-liquid equilibria, and engine cycle performance. Aqueous and ammoniac single and mixed salt solutions in single and multisolvent systems are investigated. An accurate correlation is developed to evaluate properties for concentrated electrolyte solutions. Sensitivity analysis is used to determine the impact of molecular parameters on the thermodynamic properties and cycle performance. The preferred electrolytes are of 1-1 valence type, small ion size, high molecular weight, and in strongly colligative cosolvent. The operating windows are determined for a number of absorption fluids of industrial importance.
Thermodynamic and transport properties of fluids
Fessler, T. E.
1980-01-01
Computer program subroutine FLUID calculates thermodynamic and transport properties of pure fluids in liquid, gas, or two-phase (liquid/gas) conditions. Program determines thermodynamic state from assigned values for temperature and density, pressure and density, temperature and pressure, pressure and entropy, or pressure and enthalpy.
Thermodynamic Property Needs for the Oleochemical Industry
DEFF Research Database (Denmark)
Ana Perederic, Olivia; Kalakul, Sawitree; Sarup, Bent
and/or reliable thermodynamic models for the chemicals involved. Limited availability ofconsistent physical and thermodynamic properties of lipids compounds and their mixtures lead to difficulties with the use of process simulators for process synthesis and design, since all themodels to be used...
Tables of thermodynamic properties of sodium
Energy Technology Data Exchange (ETDEWEB)
Fink, J.K.
1982-06-01
The thermodynamic properties of saturated sodium, superheated sodium, and subcooled sodium are tabulated as a function of temperature. The temperature ranges are 380 to 2508 K for saturated sodium, 500 to 2500 K for subcooled sodium, and 400 to 1600 K for superheated sodium. Tabulated thermodynamic properties are enthalpy, heat capacity, pressure, entropy, density, instantaneous thermal expansion coefficient, compressibility, and thermal pressure coefficient. Tables are given in SI units and cgs units.
Thermodynamic and transport properties of gaseous tetrafluoromethane in chemical equilibrium
Hunt, J. L.; Boney, L. R.
1973-01-01
Equations and in computer code are presented for the thermodynamic and transport properties of gaseous, undissociated tetrafluoromethane (CF4) in chemical equilibrium. The computer code calculates the thermodynamic and transport properties of CF4 when given any two of five thermodynamic variables (entropy, temperature, volume, pressure, and enthalpy). Equilibrium thermodynamic and transport property data are tabulated and pressure-enthalpy diagrams are presented.
Thermodynamic properties of yttrium cuprate
Matskevich, N. I.; Minenkov, Yu. F.; Berezovskii, G. A.
2014-01-01
The standard formation enthalpy and enthalpy from binary oxide of yttrium cuprate have been determined by solution calorimetry combining the solution enthalpies of Y2Cu2O5 and Y2O3 + 2CuO mixture in 6 M HCl at 323.15 K and literature data. The heat capacity of Y2Cu2O5 has been measured by adiabatic calorimetry from 8 up to 303 K. Smoothed values of heat capacities, entropies and enthalpies were calculated on the basis of experimental data. The thermodynamic functions (heat capacity, entropy a...
Thermodynamic properties of lithium polyvanadatomolybdate
International Nuclear Information System (INIS)
Volkov, V.L.; Zakharova, G.S.
1989-01-01
Equilibrium vapor pressures and some thermodynamic water characteristics depending on the composition of lithium depending on the composition of lithium polyvanadatomolybdate are determined. The dependences lg p H 2 O and ΔG H 2 O as f (T, nH 2 O) of Li 2 V 12-x Mo x O 31± ynH 2 O, where 0 ≤ x ≤ 3 are determined in the 295-343 K temperature range. The lg p H 2 O and ΔH H 2 O values of lithium polyvanadomolybdates depend on the content of molybdenym and water in the compound in a complex manner. At x=0.5 the extreme values of lg p H 2 O and ΔH H 2 O are observed, and at x=2 lg p H 2 O increases due to electron and structural phase variations
Systematic vibration thermodynamic properties of bromine
Liu, G. Y.; Sun, W. G.; Liao, B. T.
2015-11-01
Based on the analysis of the maturity and finiteness of vibrational levels of bromine molecule in ground state and evaluating the effect on statistical computation, according to the elementary principles of quantum statistical theorem, using the full set of bromine molecular vibrational levels determined with algebra method, the statistical contribution for bromine systematical macroscopic thermodynamic properties is discussed. Thermodynamic state functions Helmholtz free energy, entropy and observable vibration heat capacity are calculated. The results show that the determination of full set of vibrational levels and maximum vibrational quantum number is the key in the correct statistical analysis of bromine systematical thermodynamic property. Algebra method results are clearly different from data of simple harmonic oscillator and the related algebra method results are no longer analytical but numerical and are superior to simple harmonic oscillator results. Compared with simple harmonic oscillator's heat capacities, the algebra method's heat capacities are more consistent with the experimental data in the given temperature range of 600-2100 K.
Thermodynamic properties of organic compounds estimation methods, principles and practice
Janz, George J
1967-01-01
Thermodynamic Properties of Organic Compounds: Estimation Methods, Principles and Practice, Revised Edition focuses on the progression of practical methods in computing the thermodynamic characteristics of organic compounds. Divided into two parts with eight chapters, the book concentrates first on the methods of estimation. Topics presented are statistical and combined thermodynamic functions; free energy change and equilibrium conversions; and estimation of thermodynamic properties. The next discussions focus on the thermodynamic properties of simple polyatomic systems by statistical the
Thermodynamic properties of trizirconium tetraphosphate
International Nuclear Information System (INIS)
Pet'kov, V.I.; Asabina, E.A.; Kir'yanov, K.V.; Markin, A.V.; Smirnova, N.N.; Kitaev, D.B.; Kovalsky, A.M.
2005-01-01
The heat capacity measurements of the crystalline trizirconium tetraphosphate were carried out in a low-temperature adiabatic vacuum calorimeter between T=(7 and 350) K and in dynamic calorimeter between T=(330 and 640) K. The experimental data were used to calculate the standard (p 0 =0.1 MPa) thermodynamic functions Cp,m-bar /R,Δ0THm-bar /RT,Δ0TSm-bar /R,andΦm-bar =Δ0TSm-bar -Δ0THm-bar /T (where R is the universal gas constant) in the range T->(0 to 640) K. The fractal dimension D fr for the crystalline phosphate Zr 3 (PO 4 ) 4 between T=(20 and 40) K was evaluated. From hydrofluoric acid solution microcalorimetry, the enthalpy of solution of Zr 3 (PO 4 ) 4 at T=298.15 K was determined and the standard molar enthalpy of formation was derived. By combining the data obtained by the two techniques, the standard molar Gibbs function of formation of Zr 3 (PO 4 ) 4 at T=298.15 K was calculated
Thermodynamic properties of gaseous propane from model ...
African Journals Online (AJOL)
A fourth-order virial equation of state was combined with isotropic model potentials to predict accurate volumetric and caloric thermodynamic properties of propane in the gas phase. The parameters in the model were determined in a fit to speed-of-sound data alone; no other data were used. The approximation employed for ...
Computing Thermodynamic And Transport Properties Of Air
Thompson, Richard A.; Gupta, Roop N.; Lee, Kam-Pui
1994-01-01
EQAIRS computer program is set of FORTRAN 77 routines for computing thermodynamic and transport properties of equilibrium air for temperatures from 100 to 30,000 K. Computes properties from 11-species, curve-fit mathematical model. Successfully implemented on DEC VAX-series computer running VMS, Sun4-series computer running SunOS, and IBM PC-compatible computer running MS-DOS.
The calculation of thermodynamic properties of molecules
DEFF Research Database (Denmark)
van Speybroeck, Veronique; Gani, Rafiqul; Meier, Robert Johan
2010-01-01
Thermodynamic data are key in the understanding and design of chemical processes. Next to the experimental evaluation of such data, computational methods are valuable and sometimes indispensable tools in obtaining heats of formation and Gibbs free energies. The major toolboxes to obtain such quan......Thermodynamic data are key in the understanding and design of chemical processes. Next to the experimental evaluation of such data, computational methods are valuable and sometimes indispensable tools in obtaining heats of formation and Gibbs free energies. The major toolboxes to obtain...... molecules the combination of group contribution methods with group additive values that are determined with the best available computational ab initio methods seems to be a viable alternative to obtain thermodynamic properties near chemical accuracy. New developments and full use of existing tools may lead...
Consistent thermodynamic properties of lipids systems
DEFF Research Database (Denmark)
Cunico, Larissa; Ceriani, Roberta; Sarup, Bent
Physical and thermodynamic properties of pure components and their mixtures are the basic requirement for process design, simulation, and optimization. In the case of lipids, our previous works[1-3] have indicated a lack of experimental data for pure components and also for their mixtures...... different pressures, with azeotrope behavior observed. Available thermodynamic consistency tests for TPx data were applied before performing parameter regressions for Wilson, NRTL, UNIQUAC and original UNIFAC models. The relevance of enlarging experimental databank of lipids systems data in order to improve...... the performance of predictive thermodynamic models was confirmed in this work by analyzing the calculated values of original UNIFAC model. For solid-liquid equilibrium (SLE) data, new consistency tests have been developed [2]. Some of the developed tests were based in the quality tests proposed for VLE data...
Thermodynamical Properties of 56Fe
International Nuclear Information System (INIS)
Tavukcu, E.; Becker, J.A.; Bernstein, L.A.; Garrett, P.E.; Guttormsen, M.; Mitchell, G.E.; Rekstad, J.; Schiller, A.; Siem, S.; Voinov, A.; Younes, W.
2002-01-01
Average nuclear level densities close to the nuclear binding energy in 56 Fe and 57 Fe are extracted from primary γ-ray spectra. Thermal properties of 56 Fe are studied within the statistical canonical ensemble. The experimental heat capacity is compared with the theoretical heat capacity calculated within the shell model Monte Carlo approach
Thermodynamical properties of 56Fe
International Nuclear Information System (INIS)
Tavukcu, E.; Becker, J. A.; Bernstein, L. A.; Garrett, P. E.; Younes, W.; Guttormsen, M.; Rekstad, J.; Siem, S.; Mitchell, G. E.; Schiller, A.; Voinov, A.
2003-01-01
Average nuclear level densities close to the nuclear binding energy in 56Fe and 57Fe are extracted from primary γ-ray spectra. A step structure is observed in the level density for both isotopes, and is interpreted as breaking of Cooper pairs. Thermal properties of 56Fe are studied within the statistical canonical ensemble. The experimental heat capacity in 56Fe is compared with the theoretical heat capacity calculated within the shell model Monte Carlo approach
Thermodynamic properties of dissociated steam
Aminov, R. Z.; Gudym, A. A.
2017-11-01
In connection with the development of hydrogen technologies and the generation of dissociated steam as a result of the oxidation of hydrogen in an oxygen environment, it became necessary to determine the calorific parameters of dissociated steam. In the existing tables, the caloric parameters of dissociated steam are presented at a reference temperature of 0 K. By contrast, the authors have developed tables of dissociated steam using a reference temperature of 0°C, within the pressure range 0.01–20.0 MPa and the temperature range 1250–4000 K, along with a system of equations for the industrial calculation of the properties of dissociated steam within the temperature range 1250–2300 K and pressure range 0.01–10.0 MPa, followed by a temperature range of 2200–3600 K. During the dissociation of steam, a mixture of eight components are formed including hydrogen H, oxygen O, radicals OH and HO2, molecules of hydrogen H2, oxygen O2, steam H2O, and hydrogen peroxide H2O2. All existing tables of the properties of dissociated steam are based on a mixture of six components: H2, O2, OH, H, O, and H2O. For evaluate whether this is an oversimplification, the composition of the mixture comprising all eight components was calculated, taking into account additional chemical reactions for the formation of HO2 and H2O2. At a pressure of 0.01 MPa, the maximum mole fraction of HO2 was 2.8·10‑5 at a temperature of 3000 K, and at a pressure of 10 MPa, the maximum mole fraction was 5·10‑5 at a temperature of 4000 K. The mole fraction of H2O2 was much lower. Thus at temperatures up to 3000 K, calculations of the properties of dissociated steam are restricted to six components.
Modeling the thermodynamic properties of plutonium
International Nuclear Information System (INIS)
Stan, Marius
2000-01-01
The golden dream of any modeling enterprise is to predict the properties of the studied system in a new and often 'hostile' environment. The basis of this kind of work is the careful, accurate assessment of the system properties in normal conditions. What 'normal conditions' means for plutonium is an interesting question itself. This work is dedicated to modeling only a fraction of the remarkable characteristics of this 'mysterious' material, that is the thermodynamic properties of its six allotropic phases (seven under pressure), the liquid phase, and the vapor phase. The goal is to provide valuable information for the calculation of alloyed plutonium phase diagrams
Modeling the thermodynamic properties of plutonium
Stan, Marius
2000-07-01
The golden dream of any modeling enterprise is to predict the properties of the studied system in a new and often "hostile" environment. The basis of this kind of work is the careful, accurate assessment of the system properties in normal conditions. What "normal conditions" means for plutonium is an interesting question itself. This work is dedicated to modeling only a fraction of the remarkable characteristics of this "mysterious" material, that is the thermodynamic properties of its six allotropic phases (seven under pressure), the liquid phase, and the vapor phase. The goal is to provide valuable information for the calculation of alloyed plutonium phase diagrams.
Thermodynamic Properties and Thermodynamic Geometries of Black p-Branes
International Nuclear Information System (INIS)
Yi-Huan Wei; Xiao Cui; Jia-Xin Zhao
2016-01-01
The heat capacity and the electric capacitance of the black p-branes (BPB) are generally defined, then they are calculated for some special processes. It is found that the Ruppeiner thermodynamic geometry of BPB is flat. Finally, we give some discussions for the flatness of the Ruppeiner thermodynamic geometry of BPB and some black holes. (paper)
The thermodynamic properties of benzothiazole and benzoxazole
Energy Technology Data Exchange (ETDEWEB)
Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.
1991-08-01
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 information, provide insights for the design of cost-effective methods of heteroatom removal. The results reported here, and in a companion report to be completed, will point the way to the development of new methods of heteroatom removal from heavy petroleum. Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for benzothiazole and benzoxazole. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, comparative ebulliometry, inclinded-piston gauge manometry, and differential-scanning calorimetry (d.s.c). Critical property estimates are made for both compounds. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for both compounds for selected temperatures between 280 K and near 650 K. The Gibbs energies of formation will be used in a subsequent report in thermodynamic calculations to study the reaction pathways for the removal of the heteratoms by hydrogenolysis. The results obtained in this research are compared with values present in the literature. The failure of a previous adiabatic heat capacity study to see the phase transition in benzothiazole is noted. Literature vibrational frequency assignments were used to calculate ideal gas entropies in the temperature range reported here for both compounds. Resulting large deviations show the need for a revision of those assignments. 68 refs., 6 figs., 15 tabs.
Industrial Requirements for Thermodynamics and Transport Properties
DEFF Research Database (Denmark)
Hendriks, Eric; Kontogeorgis, Georgios; Dohrn, Ralf
2010-01-01
reactive systems (simultaneous chemical and physical equilibrium). Education in thermodynamics is perceived as key, for the future application of thermodynamics in the industry. A number of suggestions for improvement were made at all three levels (undergraduate, postgraduate, and professional development...... addressed to or written by industrial colleagues, are discussed initially. This provides the context of the survey and material with which the results of the survey can be compared. The results of the survey have been divided into the themes: data, models, systems, properties, education, and collaboration...... are becoming interesting to a number of survey participants. Despite the academic success of molecular simulation techniques, the survey does not indicate great interest in it or its future development. Algorithms appear to be a neglected area, but improvements are still needed especially for multiphase...
Thermodynamic and transport properties of liquid gallium
International Nuclear Information System (INIS)
Park, H.Y.; Jhon, M.S.
1982-01-01
The significant structure theory of liquids has been successfully applied to liquid gallium. In this work, we have assumed that two structures exist simultaneously in liquid gallium. One is considerec as loosely close packed β-Ga-like structure and the other is remainder of solid α-Ga or α-Ga-like structure. This two structural model is introduced to construct the liquid partition function. Using the partition function, the thermodynamic and transport properties are calculated ever a wide temperature range. The calculated results are quite satisfactory when compared with the experimental results. (Author)
Thermodynamic properties of mixtures of liquids
International Nuclear Information System (INIS)
Benedetti, A.V.; Cilense, M.; Vollet, D.
1982-01-01
The molar excess enthalpy (H sup(-E)) of water-ethanol has been measured at 298.15, 306.85, 313.95 and 319.75 K. The mixtures are exothermics at studied temperatures with minimum values of -785, -655, -555 and -490 J. mol -1 respectively, at value of X 2 about 0.16. The other thermodynamics properties have been obtained from experimental data and data from literature. The results are interpreted qualitatively by considering molecular interactions in solution. (Author) [pt
Specification and thermodynamical properties of semigroup actions
Rodrigues, Fagner B.; Varandas, Paulo
2016-05-01
In the present paper, we study the thermodynamical properties of finitely generated continuous subgroup actions. We propose a notion of topological entropy and pressure functions that do not depend on the growth rate of the semigroup and introduce strong and orbital specification properties, under which the semigroup actions have positive topological entropy and all points are entropy points. Moreover, we study the convergence and Lipschitz regularity of the pressure function and obtain relations between topological entropy and exponential growth rate of periodic points in the context of semigroups of expanding maps, obtaining a partial extension of the results obtained by Ruelle for ℤd-actions [D. Ruelle, Trans. Am. Math. Soc., 187, 237-251 (1973)]. The specification properties for semigroup actions and the corresponding one for its generators and the action of push-forward maps are also discussed.
DERIVED THERMODYNAMIC PROPERTIES OF [o-XYLENE OR p ...
African Journals Online (AJOL)
Preferred Customer
This paper is a continuation of our earlier work related to the study of thermodynamic properties of binary and ternary mixtures [1-6]. Reliable data on phase behavior and thermodynamic excess properties of multi component fluid mixtures are necessary for the proper design of synthesis and separation processes of the ...
Hansen, C Frederick; Heims, Steve P
1958-01-01
Thermodynamic and transport properties of high temperature air, and the reaction rates for the important chemical processes which occur in air, are reviewed. Semiempirical, analytic expressions are presented for thermodynamic and transport properties of air. Examples are given illustrating the use of these properties to evaluate (1) equilibrium conditions following shock waves, (2) stagnation region heat flux to a blunt high-speed body, and (3) some chemical relaxation lengths in stagnation region flow.
The VLab repository of thermodynamics and thermoelastic properties of minerals
Da Silveira, P. R.; Sarkar, K.; Wentzcovitch, R. M.; Shukla, G.; Lindemann, W.; Wu, Z.
2015-12-01
Thermodynamics and thermoelastic properties of minerals at planetary interior conditions are essential as input for geodynamics simulations and for interpretation of seismic tomography models. Precise experimental determination of these properties at such extreme conditions is very challenging. Therefore, ab initio calculations play an essential role in this context, but at the cost of great computational effort and memory use. Setting up a widely accessible and versatile mineral physics database can relax unnecessary repetition of such computationally intensive calculations. Access to such data facilitates transactional interaction across fields and can advance more quickly insights about deep Earth processes. Hosted by the Minnesota Supercomputing Institute, the Virtual Laboratory for Earth and Planetary Materials (VLab) was designed to develop and promote the theory of planetary materials using distributed, high-throughput quantum calculations. VLab hosts an interactive database of thermodynamics and thermoelastic properties or minerals computed by ab initio. Such properties can be obtained according to user's preference. The database is accompanied by interactive visualization tools, allowing users to repeat and build upon previously published results. Using VLab2015, we have evaluated thermoelastic properties, such as elastic coefficients (Cij), Voigt, Reuss, and Voigt-Reuss-Hill aggregate averages for bulk (K) and shear modulus (G), shear wave velocity (VS), longitudinal wave velocity (Vp), and bulk sound velocity (V0) for several important minerals. Developed web services are general and can be used for crystals of any symmetry. Results can be tabulated, plotted, or downloaded from the VLab website according to user's preference.
Thermodynamic properties of actinide aqueous species relevant to geochemical problems
International Nuclear Information System (INIS)
Fuger, J.
1992-01-01
The status of our knowledge of the basic thermodynamic properties of the aqueous complexes of the actinides in their different valency states with two environmentally important ligands, namely hydroxide and carbonate is overviewed. Even in the case of uranium which has been the most studied, gaps are found among the relative wealth of trustworthy formation constants, especially for the less stable valence states. The need for substantial improvement of our knowledge in the case of the other actinides, especially transuranium elements, is outlined. The relative scarcity of enthalpy of formation data is also stressed. (orig.)
Thermodynamical and dynamical properties of charged BTZ black holes
Energy Technology Data Exchange (ETDEWEB)
Tang, Zi-Yu; Wang, Bin [Shanghai Jiao Tong University, Department of Physics and Astronomy, Center for Astronomy and Astrophysics, Shanghai (China); Zhang, Cheng-Yong [Peking University, Center for High-Energy Physics, Beijing (China); Kord Zangeneh, Mahdi [Shanghai Jiao Tong University, Department of Physics and Astronomy, Center for Astronomy and Astrophysics, Shanghai (China); Shahid Chamran University of Ahvaz, Physics Department, Faculty of Science, Ahvaz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM)-Maragha, P. O. Box: 55134-441, Maragha (Iran, Islamic Republic of); Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Saavedra, Joel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile)
2017-06-15
We investigate the spacetime properties of BTZ black holes in the presence of the Maxwell field and Born-Infeld field and find rich properties in the spacetime structures when the model parameters are varied. Employing Landau-Lifshitz theory, we examine the thermodynamical phase transition in the charged BTZ black holes. We further study the dynamical perturbation in the background of the charged BTZ black holes and find different properties in the dynamics when the thermodynamical phase transition occurs. (orig.)
Thermodynamic properties of liquid solutions Ag-Tl-Te
Energy Technology Data Exchange (ETDEWEB)
Zaleska, E.; Sztuba, Z.; Sroka, A.; Gawel, W. [Department of Analytical Chemistry, Wroclaw University of Medicine, Wroclaw (Poland)
1998-12-31
Excess partial molar thermodynamic functions for the Ag-Tl-Te liquid solutions have been determined along the sections: X{sub Ag}:X{sub Te} = 1:4, 2:3, 1:1 and 3:2. The thermodynamic properties have been discussed in dependence on the number of associates existing in the liquid. (author) 34 refs,5 figs, 1 tab
Composition and Thermodynamic Properties of Air in Chemical Equilibrium
Moeckel, W E; Weston, Kenneth C
1958-01-01
Charts have been prepared relating the thermodynamic properties of air in chemical equilibrium for temperatures to 15,000 degrees k and for pressures 10(-5) to 10 (plus 4) atmospheres. Also included are charts showing the composition of air, the isentropic exponent, and the speed of sound. These charts are based on thermodynamic data calculated by the National Bureau of Standards.
Dimensionless thermodynamics: a new paradigm for liquid state properties.
Sanchez, Isaac C
2014-08-07
Equations of state in the van der Waals genre suggest that saturated liquids should adhere to the following corresponding states principle (CSP): saturated liquids at the same reduced density (ρR = ρ/ρc) have comparable dimensionless thermodynamic properties. This CSP is shown to be applicable to a variety of thermodynamic properties that include entropy of vaporization, cohesive energy density, thermal expansion coefficient, isothermal compressibility, thermal pressure coefficient, compressibility factor, temperature coefficient of the vapor pressure, heat capacity difference, and surface tension. For two classes of liquids, all properties rendered dimensionless by the proper choice of scaling variables superpose to form "master curves" that illustrate the CSP. Using scaled particle theory, an improved van der Waals model is developed whose results are compared with existing experimental thermodynamic data in dimensionless form. Properly expressing thermodynamic properties in dimensionless form acts to consolidate and harmonize liquid state properties.
Thermodynamic properties of the DUPIC fuel and its performance
Energy Technology Data Exchange (ETDEWEB)
Park, Kwang Heon; Kim, Hee Moon [Kyung Hee Univ., Seoul (Korea, Republic of)
1997-07-01
This study describes thermodynamic properties of DUPIC fuel and performance. In initial state, DUPIC fuel which contains fissile materials is different from general nuclear fuel. So this study analyzed oxygen potential, thermal conductivity and specific heat of the DUPIC fuel.
Thermodynamical properties and thermoelastic coupling of complex macroscopic structure
International Nuclear Information System (INIS)
Fabbri, M.; Sacripanti, A.
1996-11-01
Gross qualitative/quantitative analysis about thermodynamical properties and thermoelastic coupling (or elastocaloric effect) of complex macroscopic structure (running shoes) is performed by infrared camera. The experimental results showed the achievability of a n industrial research project
Comparing contribution of flexural and planar modes to thermodynamic properties
Mann, Sarita; Rani, Pooja; Jindal, V. K.
2017-05-01
Graphene, the most studied and explored 2D structure has unusual thermal properties such as negative thermal expansion, high thermal conductivity etc. We have already studied the thermal expansion behavior and various thermodynamic properties of pure graphene like heat capacity, entropy and free energy. The results of thermal expansion and various thermodynamic properties match well with available theoretical studies. For a deeper understanding of these properties, we analyzed the contribution of each phonon branch towards the total value of the individual property. To compute these properties, the dynamical matrix was calculated using VASP code where the density functional perturbation theory (DFPT) is employed under quasi-harmonic approximation in interface with phonopy code. It is noticed that transverse mode has major contribution to negative thermal expansion and all branches have almost same contribution towards the various thermodynamic properties with the contribution of ZA mode being the highest.
Thermodynamic properties of small aggregates of rare-gas atoms
Etters, R. D.; Kaelberer, J.
1975-01-01
The present work reports on the equilibrium thermodynamic properties of small clusters of xenon, krypton, and argon atoms, determined from a biased random-walk Monte Carlo procedure. Cluster sizes ranged from 3 to 13 atoms. Each cluster was found to have an abrupt liquid-gas phase transition at a temperature much less than for the bulk material. An abrupt solid-liquid transition is observed for thirteen- and eleven-particle clusters. For cluster sizes smaller than 11, a gradual transition from solid to liquid occurred over a fairly broad range of temperatures. Distribution of number of bond lengths as a function of bond length was calculated for several systems at various temperatures. The effects of box boundary conditions are discussed. Results show the importance of a correct description of boundary conditions. A surprising result is the slow rate at which system properties approach bulk behavior as cluster size is increased.
Thermodynamic Properties of Chromium Adsorption by Sediments ...
African Journals Online (AJOL)
MBI
2013-06-19
Jun 19, 2013 ... aqueous system and therefore decreasing percentage adsorption. Thermodynamic Parameters. The changes of Gibb's free energy, enthalpy, entropy and isosteric heats of adsorption were all calculated using the data generated from the experiments and was presented in Tables 3a and 3b respectively.
Thermodynamic properties of a quasi-harmonic model for ferroelectric transitions
International Nuclear Information System (INIS)
Mkam Tchouobiap, S E; Mashiyama, H
2011-01-01
Within a framework of a quasi-harmonic model for quantum particles in a local potential of the double Morse type and within the mean-field approximation for interactions between particles, we investigate the thermodynamic properties of ferroelectric materials. A quantum thermodynamic treatment gives analytic expressions for the internal energy, the entropy, the specific heat, and the static susceptibility. The calculated thermodynamic characteristics are studied as a function of temperature and energy barrier, where it is shown that at the proper choice of the theory parameters, particularly the energy barrier, the model system exhibits characteristic features of either second-order tricritical or first-order phase transitions. Our results indicate that the barrier energy seems to be an important criterion for the character of the structural phase transition. The influence of quantum fluctuations manifested on zero-point energy on the phase transition and thermodynamic properties is analyzed and discussed. This leads to several quantum effects, including the existence of a saturation regime at low temperatures, where the order parameter saturates giving thermodynamic saturation of the calculated thermodynamic quantities. It is found that both quantum effects and energy barrier magnitude have an important influence on the thermodynamic properties of the ferroelectric materials and on driving the phase transition at low temperatures. Also, the analytical parameters' effect on the transition temperature is discussed, which seems to give a general insight into the structural phase transition and its nature.
Thermodynamic properties of indium-antimony alloys
International Nuclear Information System (INIS)
Gerasimov, Ya.I.; Goryacheva, V.I.; Gejderikh, V.A.
1988-01-01
Method of electromotive forces is used to obtain thermodynamic parameters of reaction of In x Sb (1-x) phase formation from liquid indium and solid indium mono-antimonide. For alloy compositions with x=0.75-0.55 liquidus coordinates on phase diagram are determined. Nonmonotonous dependence of partial entropy and enthalpy of indium on composition of liquid alloys, that is connected with ordering, is detected. 20 refs.; 2 figs.; 2 tabs
A Systematic Identification Method for Thermodynamic Property Modelling
DEFF Research Database (Denmark)
Ana Perederic, Olivia; Cunico, Larissa; Sarup, Bent
2017-01-01
In this work, a systematic identification method for thermodynamic property modelling is proposed. The aim of the method is to improve the quality of phase equilibria prediction by group contribution based property prediction models. The method is applied to lipid systems where the Original UNIFAC...
Thermodynamic properties and environmental chemistry of chromium
Energy Technology Data Exchange (ETDEWEB)
Schmidt, R.L.
1984-07-01
Values of standard entropy, standard enthalpy of formation, and standard free energy of formation for Cr and its solid and aqueous species are tabulated in this report. These values were selected or recalculated after careful evaluation of the best available current thermochemical data. The basis for selection of data centered on conformation with the recent studies of Vasil'ev et al. (1977a,b, 1978, 1980, 1981) for Cr/sup 3 +/ data and O'Hare and Boerio (1975) for CrO/sub 4//sup 2 -/ data. The thermodynamic data presented in this report will be incorporated into the data base of the geochemical computer model, MINTEQ. The distribution of Cr in the environment among its aqueous inorganic species is, according to the thermodynamic data, highly dependent upon pH and Eh and the presence of complexing ligands. The speciation of Cr in natural waters is also controlled by reduction and complexation by organic matter, adsorption and oxidation by Mn-oxide in suspended particulate matter and sediment, and reduction by H/sub 2/S released from anoxic sediments. 89 references, 8 figures, 11 tables.
Thermodynamic properties for arsenic minerals and aqueous species
Nordstrom, D. Kirk; Majzlan, Juraj; Königsberger, Erich; Bowell, Robert J.; Alpers, Charles N.; Jamieson, Heather E.; Nordstrom, D. Kirk; Majzlan, Juraj
2014-01-01
Quantitative geochemical calculations are not possible without thermodynamic databases and considerable advances in the quantity and quality of these databases have been made since the early days of Lewis and Randall (1923), Latimer (1952), and Rossini et al. (1952). Oelkers et al. (2009) wrote, “The creation of thermodynamic databases may be one of the greatest advances in the field of geochemistry of the last century.” Thermodynamic data have been used for basic research needs and for a countless variety of applications in hazardous waste management and policy making (Zhu and Anderson 2002; Nordstrom and Archer 2003; Bethke 2008; Oelkers and Schott 2009). The challenge today is to evaluate thermodynamic data for internal consistency, to reach a better consensus of the most reliable properties, to determine the degree of certainty needed for geochemical modeling, and to agree on priorities for further measurements and evaluations.
Thermodynamic and structural properties in complexing media
International Nuclear Information System (INIS)
Di Giandomenico, M.V.
2007-10-01
Protactinium is experiencing a renewal of interest in the frame of long-term energy production. Modelling the behaviour of this element in the geosphere requires thermodynamic and structural data relevant to environmental conditions. Now deep clayey formation are considered for the disposal of radioactive waste and high values of natural sulphate contents have been determined in pore water in equilibrium with clay surface. Because of its tendency to polymerisation, hydrolysis and sorption on all solid supports, the equilibria constants relative to monomer species were determined at tracer scale (ca. 10 - 12 M) with 233 Pa. The complexation constants of Pa(V) and sulphate ions were calculated starting from a systematic study of the apparent distribution coefficient D in the system TTA/Toluene/H 2 O/Na 2 SO 4 /HClO 4 /NaClO 4 and as a function of ionic strength, temperature, free sulphate, protons and chelatant concentration. First of all, the interaction between free species H + , SO 4 - , Na + leads to the formation of HSO 4 - and NaSO 4 - , for which concentrations depend upon the related thermodynamic constants. For this purpose a computer code was developed in order to determine all free species concentration. This iterative code takes into account the influence of temperature and ionic strength (SIT modelling) on thermodynamic constants. The direct measure of Pa(V) in the organic and aqueous phase by g-spectrometry had conducted to estimate the apparent distribution coefficient D as function of free sulphate ions. Complexation constants have been determined after a mathematical treatment of D. The extrapolation of these constants at zero ionic strength have been realized by SIT modelling at different temperatures. Besides, enthalpy and entropy values were calculated. Parallelly, the structural study of Pa(V) was performed using 231 Pa. XANES and EXAFS spectra show unambiguously the absence of the trans di-oxo bond that characterizes the other early actinide
Thermodynamic properties of massive dilaton black holes II
Tamaki, Takashi
2002-01-01
We numerically reanalyze static and spherically symmetric black hole solutions in an Einstein-Maxwell-dilaton system with a dilaton potential $m_{d}^{2}\\phi^{2}$. We investigate thermodynamic properties for various dilaton coupling constants and find that thermodynamic properties change at a critical dilaton mass $m_{d,crit}$. For $m_{d}\\geq m_{d,crit}$, the black hole becomes an extreme solution for a nonzero horizon radius $r_{h,ex}$ as the Reissner-Nordstr\\"om black hole. However, if $m_{d...
Organogels thermodynamics, structure, solvent role, and properties
Guenet, Jean-Michel
2016-01-01
This book provides a physics-oriented introduction to organogels with a comparison to polymer thermoreversible gels whenever relevant. The past decade has seen the development of a wide variety of newly-synthesized molecules that can spontaneously self-assemble or crystallize from their organic or aqueous solutions to produce fibrillar networks, namely organogels, with potential applications in organic electronics, light harvesting, bio-imaging, non-linear optics, and the like. This compact volume presents a detailed outlook of these novel molecular systems with special emphasis upon their thermodynamics, morphology, molecular structure, and rheology. The definition of these complex systems is also tackled, as well as the role of the solvent. The text features numerous temperature-phase diagrams for a variety of organogels as well as illustrations of their structures at the microscopic, mesoscopic and macroscopic level. A review of some potential applications is provided including hybrid functional materials ...
Thermodynamic properties of alkali borosilicate gasses and metaborates
International Nuclear Information System (INIS)
Asano, Mitsuru
1992-01-01
Borosilicate glasses are the proposed solidifying material for storing high level radioactive wastes in deep underground strata. Those have low melting point, and can contain relatively large amount of high level radioactive wastes. When borosilicate glasses are used for this purpose, they must be sufficiently stable and highly reliable in the vitrification process, engineered storage and the disposal in deep underground strata. The main vaporizing components from borosilicate glasses are alkali elements and boron. In this report, as for the vaporizing behavior of alkali borosilicate glasses, the research on thermodynamic standpoint carried out by the authors is explained, and the thermodynamic properties of alkali metaborates of monomer and dimer which are the main evaporation gases are reported. The evaporation and the activity of alkali borosilicate glasses, the thermodynamic properties of alkali borosilicate glasses, gaseous alkali metaborates and alkali metaborate system solid solution and so on are described. (K.I.)
Entropy, related thermodynamic properties, and structure of methylisocyanate
International Nuclear Information System (INIS)
Davis, Phil S.; Kilpatrick, John E.
2013-01-01
Highlights: ► The thermodynamic properties of methylisocyanate have been determined by isothermal calorimetry from 15 to 298.15 K. ► The third law entropy has been compared with the entropy calculated by statistical thermodynamics. ► The comparisons are consistent with selected proposed molecular structures and vibrational frequencies. -- Abstract: The entropy and related thermodynamic properties of methylisocyanate, CH 3 NCO, have been determined by isothermal calorimetry. The entropy in the ideal gas state at 298.15 K and 1 atmosphere is S m o = 284.3 ± 0.6 J/K · mol. Other thermodynamic properties determined include: the heat capacity from 15 to 300 K, the temperature of fusion (T fus = 178.461 ± 0.024 K), the enthalpy of fusion (ΔH fus = 7455.2 ± 14.0 J/mol), the enthalpy of vaporization at 298.15 K (ΔH vap = 28768 ± 54 J/mol), and the vapor pressure from fusion to 300 K. Using statistical thermodynamics, the entropy in this same state has been calculated for various assumed structures for methylisocyante which have been proposed based on several spectroscopic and ab initio results. Comparisons between the experimental and calculated entropy have led to the following conclusions concerning historical differences among problematic structural properties: (1) The CNC/CNO angles can have the paired values of 140/180° or 135/173° respectively. It is not possible to distinguish between the two by this thermodynamic analysis. (2) The methyl group functions as a free rotor or near free rotor against the NCO rigid frame. The barrier to internal rotation is less than 2100 J/mol. (3) The CNC vibrational bending frequency is consistent with the more recently observed assignments at 165 and 172 cm −1 with some degree of anharmonicity or with a pure harmonic at about 158 cm −1
Thermodynamic properties of chemical species of waste radionuclides
International Nuclear Information System (INIS)
Silva, R.J.; Nitsche, H.
1984-01-01
The object of the experimental program at Lawrence Berkeley Laboratory is to identify gaps or conflicts in thermodynamic data on the solubilities of compounds and on the formation of solution complexes of waste radionuclides needed for the reliable prediction of solution concentrations. It involves laboratory measurements necessary to (1) generate specific new data, where none exists, in order to demonstrate the importance of a particular solution species, compound or solution parameter (e.g., temperature, Eh) and to (2) resolve conflicts in existing thermodynamic data on important species or compounds. The measurement of the solubility of AmOHCO 3 in 0.1 M NaClO 4 at 25 0 C and 1 atmosphere pressure has been completed. From the experimental data, an average solubility product quotient, Qsp, was evaluated for the reaction, AmOHCO 3 (S) + 2H + = Am 3+ + HCO 3 - + H 2 O. The logarithm of Qsp was calculated to be 2.74 +/- .17. Speciation calculations, using this new data plus reported data on the solubility of Am(OH) 3 and the hydrolysis and carbonate complexation of Am 3+ , indicate that the presence of carbonate can have a substantial effect on the nature of compounds and solution species formed by americium in ground waters. Since actinides in a given oxidation state tend to exhibit similar chemical properties, this result should apply to other actinides in the trivalent state. Thus, the effect of carbonate on the solubilities and complexation of trivalent actinides should be included in any predictive modelling studies required for licensing. 27 references, 4 figures, 5 tables
Thermodynamic properties of bulk and confined water
Energy Technology Data Exchange (ETDEWEB)
Mallamace, Francesco, E-mail: francesco.mallamace@unime.it [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Corsaro, Carmelo [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Mallamace, Domenico [Dipartimento di Scienze dell' Ambiente, della Sicurezza, del Territorio, degli Alimenti e della Salute, Università di Messina, I-98166 Messina (Italy); Vasi, Sebastiano; Vasi, Cirino [IPCF-CNR, I-98166 Messina (Italy); Stanley, H. Eugene [Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States)
2014-11-14
The thermodynamic response functions of water display anomalous behaviors. We study these anomalous behaviors in bulk and confined water. We use nuclear magnetic resonance (NMR) to examine the configurational specific heat and the transport parameters in both the thermal stable and the metastable supercooled phases. The data we obtain suggest that there is a behavior common to both phases: that the dynamics of water exhibit two singular temperatures belonging to the supercooled and the stable phase, respectively. One is the dynamic fragile-to-strong crossover temperature (T{sub L} ≃ 225 K). The second, T{sup *} ∼ 315 ± 5 K, is a special locus of the isothermal compressibility K{sub T}(T, P) and the thermal expansion coefficient α{sub P}(T, P) in the P–T plane. In the case of water confined inside a protein, we observe that these two temperatures mark, respectively, the onset of protein flexibility from its low temperature glass state (T{sub L}) and the onset of the unfolding process (T{sup *})
Thermodynamic properties of alkaline earth metal oxides
International Nuclear Information System (INIS)
Chekhovskoj, V.Ya.; Irgashov, Kh.
1990-01-01
Analysis of the known experimental data on enthalpy and heat capacity of CaO, SrO, BaO and RaO above 300 K is performed. New results of experimental study: enthalpy and heat capacity in solid and liquid states of BaO up to 2500 K, SrO up to 3000 K, CaO - up to 3100 K, as well as melting points, melting heats and entropies, heat capacity of melts and formation energy of anion and cation vacancy pair are presented. For Ra evaluations of temperature, melting heat and entropy, melt heat capacity, Debye point and formation energy of anion and cation vacancy pairs are made. On the basis of high-temperature data on enthalpy and low-temperature literature data on heat capacity the tables of thermodynamic functions in the range of 0-2500 K for BaO, 0-1300 K for SrO and 0-3128 K for CaO are calculated
Prediction of thermodynamic properties of coal derivatives
International Nuclear Information System (INIS)
Donohue, M.D.
1993-09-01
We have developed new equations of state for pure-component chain molecules. The excellent performance of complicated theories, such as the Generalized Flory Dimer (GFD) theory can be mimicked by simpler equations, if assumptions for the shape parameters are made. We developed engineering correlations based on GFD theory, using local composition theory to take into account attractive forces. During this period, we compared methods for calculating repulsive and attractive contributions to equation of state against computer simulation data for hard and square-well chains, and against experimental data from the literature. We also have studied microstructure and local order in fluids that contain asymmetric molecules. We developed a thermodynamic model for polar compounds based on a site-site interaction approach. We have shown the equivalence of various classes of theories for hydrogen bonding, and used this equivalence to derive a multiple site model for water. In addition, simple cubic equations of state have been applied to calculate physical and chemical-reaction equilibria in nonideal systems. We measured infinite dilution activity coefficients using HPLC. We also measured high pressure vapor liquid equilibria of ternary and quaternary systems containing supercritical solvents. We used FT-IR spectroscopy to examine self-association of aliphatic alcohols due to hydrogen bonding, and to investigate the hydrogen bonding in polymer-solvent mixtures
Computer program for calculating thermodynamic and transport properties of fluids
Hendricks, R. C.; Braon, A. K.; Peller, I. C.
1975-01-01
Computer code has been developed to provide thermodynamic and transport properties of liquid argon, carbon dioxide, carbon monoxide, fluorine, helium, methane, neon, nitrogen, oxygen, and parahydrogen. Equation of state and transport coefficients are updated and other fluids added as new material becomes available.
Elastic and thermodynamic properties of zirconium- and hafnium ...
Indian Academy of Sciences (India)
2018-02-02
Feb 2, 2018 ... https://doi.org/10.1007/s12034-017-1537-3. Elastic and thermodynamic properties of zirconium- and hafnium-doped Rh3V intermetallic compounds: potential aerospace material. M MANJULA, M SUNDARESWARI. ∗ and E VISWANATHAN. Department of Physics, Sathyabama University, Chennai 600119, ...
Thermodynamic Properties of a Trapped Interacting Bose Gas
Shi, Hualin; Zheng, Wei-Mou
1996-01-01
A Bose gas in an external potential is studied by means of the local density approximation. Analytical results are derived for the thermodynamic properties of an ideal Bose gas in a generic power-law trapping potential, and their dependence on the mutual interaction of atoms in the case of a non-ideal Bose gas.
Computer programs for thermodynamic and transport properties of hydrogen
Hall, W. J.; Mc Carty, R. D.; Roder, H. M.
1968-01-01
Computer program subroutines provide the thermodynamic and transport properties of hydrogen in tabular form. The programs provide 18 combinations of input and output variables. This program is written in FORTRAN 4 for use on the IBM 7044 or CDC 3600 computers.
Elastic and thermodynamic properties of zirconium-and hafnium ...
Indian Academy of Sciences (India)
... Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 41; Issue 1. Elastic and thermodynamic properties of zirconium- and hafnium-doped Rh 3 V intermetallic compounds: potential aerospace material. M MANJULA M SUNDARESWARI E VISWANATHAN. Volume 41 Issue 1 February 2018 Article ID 19 ...
Elastic and Thermodynamic Properties of Zirconium and Hafnium ...
Indian Academy of Sciences (India)
65
Intermetallic Compound– Potential Aerospace Material. M. Manjula, M. Sundareswari* and E. Viswanathan. Department of Physics, Sathyabama University, Tamilnadu, India. Email: sundare65@gmail.com. Abstract. Structural, electronic, mechanical and thermodynamic properties of Rh3Zrx V1-x and Rh3HfxV1-x.
Structural, elastic and thermodynamic properties of Ti2SC
Indian Academy of Sciences (India)
Administrator
Abstract. The structural parameters, elastic constants and thermodynamic properties of Ti2SC were investi- gated under pressure and temperature by using first-principles plane-wave pseudopotential density functional theory within the generalized gradient approximation. The obtained results are in agreement with the.
Review and recommended thermodynamic properties of FeCO3
DEFF Research Database (Denmark)
Fosbøl, Philip Loldrup; Thomsen, Kaj; Stenby, Erling Halfdan
2010-01-01
An extensive review of entropy, enthalpy of formation and Gibbs energy of formation, heat capacity, aqueous solubility and solubility constant of FeCO3 is given. A consistent set of thermodynamic properties for FeCO3 and relevant aqeous species is selected and recommended for use. Speciation...
High-temperature of thermodynamic properties of sodium
Energy Technology Data Exchange (ETDEWEB)
Padilla, A. Jr.
1977-01-01
The set of high-temperature thermodynamic properties for sodium in the two-phase and subcooled-liquid regions which was previously recommended, has been modified to incorporate recent experimental data. In particular, replacement of the previously estimated critical constants with experimentally-determined values has resulted in substantial differences in the region of the critical point. The following thermodynamic properties were determined: pressure, density, enthalpy, entropy, internal energy, compressibility (adiabatic and isothermal), thermal expansion coefficient, thermal pressure coefficient, and specific heat (constant-pressure and constant-volume). These properties were determined for the saturated liquid, saturated vapor, subcooled liquid, and superheated vapor. The superheated vapor properties are limited to low pressures and more work is required to extend them to higher pressures. The supercritical region was not investigated.
Thermodynamic and transport properties of cryogenic propellants and related fluids
Johnson, V. J.
1973-01-01
Significant advances have been made in recent years in the quality and range of thermophysical data for the cryogenic propellants, pressurants, and inertants. A review of recently completed and current data compilation projects for helium, hydrogen, argon, nitrogen, oxygen, fluorine, and methane is given together with recommended references for thermodynamic and transport property data tables for these fluids. Modern techniques in the plotting of thermodynamic charts from tabular data (or from functions such as the equation of state) have greatly improved their precision and value. A list of such charts is included.
Zhou, S.; Solana, J. R.
2018-03-01
Monte Carlo NVT simulations have been performed to obtain the thermodynamic and structural properties and perturbation coefficients up to third order in the inverse temperature expansion of the Helmholtz free energy of fluids with potential models proposed in the literature for diamond and wurtzite lattices. These data are used to analyze performance of a coupling parameter series expansion (CPSE). The main findings are summarized as follows, (1) The CPSE provides accurate predictions of the first three coefficient in the inverse temperature expansion of Helmholtz free energy for the potential models considered and the thermodynamic properties of these fluids are predicted more accurately when the CPSE is truncated at second or third order. (2) The Barker-Henderson (BH) recipe is appropriate for determining the effective hard sphere diameter for strongly repulsive potential cores, but its performance worsens with increasing the softness of the potential core. (3) For some thermodynamic properties the first-order CPSE works better for the diamond potential, whose tail is dominated by repulsive interactions, than for the potential, whose tail is dominated by attractive interactions. However, the first-order CPSE provides unsatisfactory results for the excess internal energy and constant-volume excess heat capacity for the two potential models.
Adsorptive, Kinetic, Thermodynamic and Inhibitive Properties of ...
African Journals Online (AJOL)
The adsorption of Cissus populnea stem extract and its subsequent corrosion inhibition properties on aluminum in 0.5 M HCl solutions have been investigated using weight loss measurements. Inhibition efficiency of the plant extract increased with concentration but decreased with rise in temperature. The adsorption of the ...
Thermodynamic properties of superheated and supercritical steam
Energy Technology Data Exchange (ETDEWEB)
Malhotra, A. [Indian Inst. of Technology, New Delhi (India). Dept. of Mechanical Engineering; Panda, D.M.R. [Dadri Gas Power Station, NTPC, Gautam Buddha Nagar (India)
2001-07-01
An existing formulation for steam properties is due to Irvine and Liley. Their equations are convenient to program and do not require excessive computational time to produce results. The properties computed from these equations compare favourably with standard data. An additional advantage of these equations is that they follow prescribed theoretical trends by reducing to perfect-gas behaviour away from the saturation dome. However, a difficulty with these equations is that, at pressures above 10 MPa and close to the saturation dome, unacceptably large errors (above 10%) are produced. These equations are examined in the present work with a view towards enhancing their range of application through the use of additional functions. It is shown that the errors may be reduced to within 1% over the entire range of pressures (both sub-critical and super-critical pressures) required in steam-plant calculations. (author)
Symmetry, Optical Properties and Thermodynamics of Neptunium(V Complexes
Directory of Open Access Journals (Sweden)
Linfeng Rao
2009-12-01
Full Text Available Recent results on the optical absorption and symmetry of the Np(V complexes with dicarboxylate and diamide ligands are reviewed. The importance of recognizing the “silent” feature of centrosymmetric Np(V species in analyzing the absorption spectra and calculating the thermodynamic constants of Np(V complexes is emphasized.
Intermolecular interactions and the thermodynamic properties of supercritical fluids.
Yigzawe, Tesfaye M; Sadus, Richard J
2013-05-21
The role of different contributions to intermolecular interactions on the thermodynamic properties of supercritical fluids is investigated. Molecular dynamics simulation results are reported for the energy, pressure, thermal pressure coefficient, thermal expansion coefficient, isothermal and adiabatic compressibilities, isobaric and isochoric heat capacities, Joule-Thomson coefficient, and speed of sound of fluids interacting via both the Lennard-Jones and Weeks-Chandler-Andersen potentials. These properties were obtained for a wide range of temperatures, pressures, and densities. For each thermodynamic property, an excess value is determined to distinguish between attraction and repulsion. It is found that the contributions of intermolecular interactions have varying effects depending on the thermodynamic property. The maxima exhibited by the isochoric and isobaric heat capacities, isothermal compressibilities, and thermal expansion coefficient are attributed to interactions in the Lennard-Jones well. Repulsion is required to obtain physically realistic speeds of sound and both repulsion and attraction are necessary to observe a Joule-Thomson inversion curve. Significantly, both maxima and minima are observed for the isobaric and isochoric heat capacities of the supercritical Lennard-Jones fluid. It is postulated that the loci of these maxima and minima converge to a common point via the same power law relationship as the phase coexistence curve with an exponent of β = 0.32. This provides an explanation for the terminal isobaric heat capacity maximum in supercritical fluids.
Thermodynamic properties of fluids from Fluctuation Solution Theory
International Nuclear Information System (INIS)
O'Connell, J.P.
1990-01-01
Fluctuation Theory develops exact relations between integrals of molecular correlation functions and concentration derivatives of pressure and chemical potential. These quantities can be usefully correlated, particularly for mechanical and thermal properties of pure and mixed dense fluids and for activities of strongly nonideal liquid solutions. The expressions yield unique formulae for the desirable thermodynamic properties of activity and density. The molecular theory origins of the flucuation properties, their behavior for systems of technical interest and some of their successful correlations will be described. Suggestions for fruitful directions will be suggested
Fermi, Enrico
1956-01-01
Indisputably, this is a modern classic of science. Based on a course of lectures delivered by the author at Columbia University, the text is elementary in treatment and remarkable for its clarity and organization. Although it is assumed that the reader is familiar with the fundamental facts of thermometry and calorimetry, no advanced mathematics beyond calculus is assumed.Partial contents: thermodynamic systems, the first law of thermodynamics (application, adiabatic transformations), the second law of thermodynamics (Carnot cycle, absolute thermodynamic temperature, thermal engines), the entr
Thermodynamic properties of a rotating Bose gas in harmonic trap
Hassan, A. S.; El-Badry, A. M.; Soliman, S. S. M.
2011-10-01
In this paper, the thermodynamic properties of a rotating Bose gas in harmonic trap are investigated. In particularly, the condensate fraction, critical temperature and heat capacity are analytically calculated. A simple semiclassical approximation, which is the density of state approach, is suggested. This approach is able to include the effects, such as the finite size and the chemical potential when becomes equal to the energy of the lowest energy state, that altered the rotating ideal Bose gas simultaneously. The calculated results show that the thermodynamic properties depend strongly on the rotation rate. The rapid rotation leads to a highly anisotropic confinement potential. The possibility for dimensionality cross-over to lower dimensions for this system is discussed. We compare the outcome results with the experimental measured data of Coddington et al. [Phys. Rev. A 70, 063607 (2004)].
Composition and thermodynamic properties of dense alkali metal plasmas
Energy Technology Data Exchange (ETDEWEB)
Gabdullin, M.T. [NNLOT, al-Farabi Kazakh National University, 71 al-Farabi Str., Almaty 050035 (Kazakhstan); Ramazanov, T.S.; Dzhumagulova, K.N. [IETP, al-Farabi Kazakh National University, 71 al-Farabi Str., Almaty 050035 (Kazakhstan)
2012-04-15
In this work composition and thermodynamic properties of dense alkali metal plasmas (Li, Na) were investigated. Composition was derived by solving the Saha equations with corrections due to nonideality. The lowering of the ionization potentials was calculated on the basis of pseudopotentials by taking screening and quantum effects into account (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
THERMODYNAMIC PROPERTIES OF NINE MIXTURES OF HYDROFLUOROCARBONS AND NATURE REFRIGERANTS
Вассерман, О.А.; Козловський, С.В.; Мальчевський, В.П.
2014-01-01
The equations of state of nine mixtures of hydrofluorocarbons and nature refrigerants were compiled on the basis of experimental p,ρ,T,x- and p,T,x-dataand for two mixturesalso on the basis of the data about isochoric heat capacity. The comparison of calculated values of density and isochoric heat capacity with the experimental ones were performed and the tables of thermodynamic properties were calculated.
Thermodynamic Properties for the Simulation of Crude Oil Primary Refining
Juan Pablo Gutierrez; Leonel Alberto Benítez
2014-01-01
Commonly, the use of simulators in the industry is performed without having a proper theoretical support. Sometimes this situation is a consequence of both, lack of time and the dairy dynamism required in the refinery industries. Particularly, the application of thermodynamic models is often not properly considered for the specific process under analysis. An undesirable fact can appear, for example, when a wrong properties package is chosen or even more when this selection ste...
Thermodynamic properties of pure and doped (B, N) graphene
Mann, Sarita; Rani, Pooja; Kumar, Ranjan; Dubey, Girija S.; Jindal, V. K.
2016-01-01
Ab-initio density functional perturbation theory (DFPT) has been employed to study thermodynamical properties of pure and doped graphene sheet and the results have been compared with available theoretical and experimental data. The concentration of B and N has been varied upto 50% of the carbon atoms in graphene. Phonon frequencies are essential ingredients entering into such a calculation, which have been computed by using the dynamical matrix provided by VASP software in combination with ph...
Study on thermodynamic properties of actinoid oxides
Energy Technology Data Exchange (ETDEWEB)
Tsuji, Toshihide; Miyajima, Nobuyoshi; Kato, Tetsuya; Ochida, Manabu [Nagoya Univ. (Japan). School of Engineering; Mumomura, Tadasumi; Yamashita, Toshiyuki; Nitani, Noriko; Ouchi, Kinji
1996-01-01
Since long-life transuranium elements (TRU) accumulate associated with a progress of high-burnup of fuel, TRU quenching in a reactor or an accelerator has been examined in Japan. To design a fuel for TRU quenching, thermal expansion is an important thermal parameter along with thermal capacity and heat transfer coefficient. Here, lattice constants of PuO{sub 2} ThO{sub 2}, UO{sub 2} and NpO{sub 2} were investigated by high temperature X-ray diffraction, showing that the lattice constants of these dioxides but UO{sub 2} obtained in this study were well coincident with Tailor`s values. The linear expansion coefficients for ThO{sub 2}, UO{sub 2} and PuO{sub 2} agreed with TPRC data and that of NpO{sub 2} with Fahey`s measurement. The linear expansion coefficient of NpO{sub 2} was found to be temperature dependent as well as other three dioxides. Those values were in inverse proportion to their melting points in a higher temperature range, whereas in a lower temperature one, the coefficient of UO{sub 2} was larger than those of NpO{sub 2} and PuO{sub 2}. Therefore, such abnormal behavior of the coefficient in a low temperature range was considered to be related to the lower Debye temperature of UO{sub 2} compared with the other dioxides. (M.N.)
Mixed 2D molecular systems: Mechanic, thermodynamic and dielectric properties
Energy Technology Data Exchange (ETDEWEB)
Beno, Juraj [Department of Physics, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19-SK Bratislava (Slovakia); Weis, Martin [Department of Physics, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19-SK Bratislava (Slovakia)], E-mail: Martin.Weis@stuba.sk; Dobrocka, Edmund [Department of Physics, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19-SK Bratislava (Slovakia); Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 841 04-SK Bratislava (Slovakia); Hasko, Daniel [International Laser Centre, Ilkovicova 3, 812 19-SK Bratislava (Slovakia)
2008-08-15
Study of Langmuir monolayers consisting of stearic acid (SA) and dipalmitoylphosphatidylcholine (DPPC) molecules was done by surface pressure-area isotherms ({pi}-A), the Maxwell displacement current (MDC) measurement, X-ray reflectivity (XRR) and atomic force microscopy (AFM) to investigate the selected mechanic, thermodynamic and dielectric properties based on orientational structure of monolayers. On the base of {pi}-A isotherms analysis we explain the creation of stable structures and found optimal monolayer composition. The dielectric properties represented by MDC generated monolayers were analyzed in terms of excess dipole moment, proposing the effect of dipole-dipole interaction. XRR and AFM results illustrate deposited film structure and molecular ordering.
Directory of Open Access Journals (Sweden)
Dunya Mahammad Babanly
2017-01-01
Full Text Available The solid-phase diagram of the Tl-TlBr-S system was clarified and the fundamental thermodynamic properties of Tl6SBr4 compound were studied on the basis of electromotive force (EMF measurements of concentration cells relative to a thallium electrode. The EMF results were used to calculate the relative partial thermodynamic functions of thallium in alloys and the standard integral thermodynamic functions (-ΔfG0, -ΔfH0, and S0298 of Tl6SBr4 compound. All data regarding thermodynamic properties of thallium chalcogen-halides are generalized and comparatively analyzed. Consequently, certain regularities between thermodynamic functions of thallium chalcogen-halides and their binary constituents as well as degree of ionization (DI of chemical bonding were revealed.
Chemical and Thermodynamic Properties at High Temperatures: A Symposium
Walker, Raymond F.
1961-01-01
This book contains the program and all available abstracts of the 90' invited and contributed papers to be presented at the TUPAC Symposium on Chemical and Thermodynamic Properties at High Temperatures. The Symposium will be held in conjunction with the XVIIIth IUPAC Congress, Montreal, August 6 - 12, 1961. It has been organized, by the Subcommissions on Condensed States and on Gaseous States of the Commission on High Temperatures and Refractories and by the Subcommission on Experimental Thermodynamics of the Commission on Chemical Thermodynamics, acting in conjunction with the Organizing Committee of the IUPAC Congress. All inquiries concerning participation In the Symposium should be directed to: Secretary, XVIIIth International Congress of Pure and Applied Chemistry, National Research Council, Ottawa, 'Canada. Owing to the limited time and facilities available for the preparation and printing of the book, it has not been possible to refer the proofs of the abstracts to the authors for checking. Furthermore, it has not been possible to subject the manuscripts to a very thorough editorial examination. Some obvious errors in the manuscripts have been corrected; other errors undoubtedly have been introduced. Figures have been redrawn only when such a step was essential for reproduction purposes. Sincere apologies are offered to authors and readers for any errors which remain; however, in the circumstances neither the IUPAC Commissions who organized the Symposium, nor the U. S. Government Agencies who assisted in the preparation of this book can accept responsibility for the errors.
Interaction potentials and thermodynamic properties of two component semiclassical plasma
Energy Technology Data Exchange (ETDEWEB)
Ramazanov, T. S.; Moldabekov, Zh. A.; Ismagambetova, T. N. [Al-Farabi Kazakh National University, IETP, 71 al-Farabi Av., Almaty 050040 (Kazakhstan); Gabdullin, M. T. [Al-Farabi Kazakh National University, NNLOT, 71 al-Farabi Av., Almaty 050040 (Kazakhstan)
2014-01-15
In this paper, the effective interaction potential in two component semiclassical plasma, taking into account the long-range screening and the quantum-mechanical diffraction effects at short distances, is obtained on the basis of dielectric response function method. The structural properties of the semiclassical plasma are considered. The thermodynamic characteristics (the internal energy and the equation of state) are calculated using two methods: the method of effective potentials and the method of micropotentials with screening effect taken into account by the Ornstein-Zernike equation in the HNC approximation.
Calculations of thermodynamic properties of PuO2 by the first-principles and lattice vibration
International Nuclear Information System (INIS)
Minamoto, Satoshi; Kato, Masato; Konashi, Kenji; Kawazoe, Yoshiyuki
2009-01-01
Plutonium dioxide (PuO 2 ) is a key compound of mixed oxide fuel (MOX fuel). To predict the thermal properties of PuO 2 at high temperature, it is important to understand the properties of MOX fuel. In this study, thermodynamic properties of PuO 2 were evaluated by coupling of first-principles and lattice dynamics calculation. Cohesive energy was estimated from first-principles calculations, and the contribution of lattice vibration to total energy was evaluated by phonon calculations. Thermodynamic properties such as volume thermal expansion, bulk modulus and specific heat of PuO 2 were investigated up to 1500 K
Thermodynamic properties of pulverized coal during rapid heating devolatilization processes
Energy Technology Data Exchange (ETDEWEB)
Proscia, W.M.; Freihaut, J.D. [United Technologies Research Center, E. Hartford, CT (United States); Rastogi, S.; Klinzing, G.E. [Univ. of Pittsburg, PA (United States)
1994-07-01
The thermodynamic properties of coal under conditions of rapid heating have been determined using a combination of UTRC facilities including a proprietary rapid heating rate differential thermal analyzer (RHR-DTA), a microbomb calorimeter (MBC), an entrained flow reactor (EFR), an elemental analyzer (EA), and a FT-IR. The total heat of devolatilization, was measured for a HVA bituminous coal (PSOC 1451D, Pittsburgh No. 8) and a LV bituminous coal (PSOC 1516D, Lower Kittaning). For the HVA coal, the contributions of each of the following components to the overall heat of devolatilization were measured: the specific heat of coal/char during devolatilization, the heat of thermal decomposition of the coal, the specific heat capacity of tars, and the heat of vaporization of tars. Morphological characterization of coal and char samples was performed at the University of Pittsburgh using a PC-based image analysis system, BET apparatus, helium pcynometer, and mercury porosimeter. The bulk density, true density, CO{sub 2} surface area, pore volume distribution, and particle size distribution as a function of extent of reaction are reported for both the HVA and LV coal. Analyses of the data were performed to obtain the fractal dimension of the particles as well as estimates for the external surface area. The morphological data together with the thermodynamic data obtained in this investigation provides a complete database for a set of common, well characterized coal and char samples. This database can be used to improve the prediction of particle temperatures in coal devolatilization models. Such models are used both to obtain kinetic rates from fundamental studies and in predicting furnace performance with comprehensive coal combustion codes. Recommendations for heat capacity functions and heats of devolatilization for the HVA and LV coals are given. Results of sample particle temperature calculations using the recommended thermodynamic properties are provided.
Thermodynamic properties of L-Theanine in different solvents
International Nuclear Information System (INIS)
Zhou, Fuli; Hou, Baohong; Tao, Xiaolong; Hu, Xiaoxue; Huang, Qiaoyin; Zhang, Zaixiang; Wang, Yongli; Hao, Hongxun
2017-01-01
Highlights: • The solubility data of L-Theanine in different solvents were measured by using an equilibrium method. • Several models were used to correlate the experimental solubility data. • The mixing thermodynamic properties were calculated. - Abstract: The solubility data of L-Theanine in pure water and three kinds of water + organic solvent mxitures were measured in temperature ranges from (278.15 to 13.15) K by using an equilibrium method. The results show that the solubility of L-Theanine increases with the increasing of temperature in all selected solvents. The modified Apelblat equation and the λ-h model were applied to correlate the solubility data in pure water, while the modified Apelblat equation, the λ-h model, the NRTL model and the Jouyban–Acree model were applied to correlate the solubility data in binary solvent mixtures. Furthermore, the mixing thermodynamic properties of L-Theanine in different solvents were also calculated based on the NRTL model and experimental solubility data.
DEFF Research Database (Denmark)
Dyekjær, Jane Dannow; Jonsdottir, Svava Osk
2003-01-01
Quantitative Structure-Property Relationship (QSPR) models for prediction of various thermodynamic properties of simple organic compounds have been developed. A number of new descriptors are proposed and used alongside with descriptors available within the Codessa program. An important feature in...
International Nuclear Information System (INIS)
Xu, Liang; Yuan, Jingqi
2015-01-01
Thermodynamic properties of the working fluid and the flue gas play an important role in the thermodynamic calculation for the boiler design and the operational optimization in power plants. In this study, a generic approach to online calculate the thermodynamic properties of the flue gas is proposed based on its composition estimation. It covers the full operation scope of the flue gas, including the two-phase state when the temperature becomes lower than the dew point. The composition of the flue gas is online estimated based on the routinely offline assays of the coal samples and the online measured oxygen mole fraction in the flue gas. The relative error of the proposed approach is found less than 1% when the standard data set of the dry and humid air and the typical flue gas is used for validation. Also, the sensitivity analysis of the individual component and the influence of the measurement error of the oxygen mole fraction on the thermodynamic properties of the flue gas are presented. - Highlights: • Flue gas thermodynamic properties in coal-fired power plants are online calculated. • Flue gas composition is online estimated using the measured oxygen mole fraction. • The proposed approach covers full operation scope, including two-phase flue gas. • Component sensitivity to the thermodynamic properties of flue gas is presented.
FLUID- THERMODYNAMIC AND TRANSPORT PROPERTIES OF FLUIDS (IBM PC VERSION)
Fessler, T. E.
1994-01-01
The accurate computation of the thermodynamic and transport properties of fluids is a necessity for many engineering calculations. The FLUID program was developed to calculate the thermodynamic and transport properties of pure fluids in both the liquid and gas phases. Fluid properties are calculated using a simple gas model, empirical corrections, and an efficient numerical interpolation scheme. FLUID produces results that are in very good agreement with measured values, while being much faster than older more complex programs developed for the same purpose. A Van der Waals equation of state model is used to obtain approximate state values. These values are corrected for real-gas effects by model correction factors obtained from tables based on experimental data. These tables also accurately compensate for the special circumstances which arise whenever phase conditions occur. Viscosity and thermal conductivity values are computed directly from tables. Interpolation within tables is based on Lagrange's three point formula. A set of tables must be generated for each fluid implemented. FLUID currently contains tables for nine fluids including dry air and steam. The user can add tables for any fluid for which adequate thermal property data is available. The FLUID routine is structured so that it may easily be incorporated into engineering programs. The IBM 360 version of FLUID was developed in 1977. It is written in FORTRAN IV and has been implemented on an IBM 360 with a central memory requirement of approximately 222K of 8 bit bytes. The IBM PC version of FLUID is written in Microsoft FORTRAN 77 and has been implemented on an IBM PC with a memory requirement of 128K of 8 bit bytes. The IBM PC version of FLUID was developed in 1986.
FLUID- THERMODYNAMIC AND TRANSPORT PROPERTIES OF FLUIDS (IBM VERSION)
Fessler, T. E.
1994-01-01
The accurate computation of the thermodynamic and transport properties of fluids is a necessity for many engineering calculations. The FLUID program was developed to calculate the thermodynamic and transport properties of pure fluids in both the liquid and gas phases. Fluid properties are calculated using a simple gas model, empirical corrections, and an efficient numerical interpolation scheme. FLUID produces results that are in very good agreement with measured values, while being much faster than older more complex programs developed for the same purpose. A Van der Waals equation of state model is used to obtain approximate state values. These values are corrected for real-gas effects by model correction factors obtained from tables based on experimental data. These tables also accurately compensate for the special circumstances which arise whenever phase conditions occur. Viscosity and thermal conductivity values are computed directly from tables. Interpolation within tables is based on Lagrange's three point formula. A set of tables must be generated for each fluid implemented. FLUID currently contains tables for nine fluids including dry air and steam. The user can add tables for any fluid for which adequate thermal property data is available. The FLUID routine is structured so that it may easily be incorporated into engineering programs. The IBM 360 version of FLUID was developed in 1977. It is written in FORTRAN IV and has been implemented on an IBM 360 with a central memory requirement of approximately 222K of 8 bit bytes. The IBM PC version of FLUID is written in Microsoft FORTRAN 77 and has been implemented on an IBM PC with a memory requirement of 128K of 8 bit bytes. The IBM PC version of FLUID was developed in 1986.
International Nuclear Information System (INIS)
Zanchini, E.
1988-01-01
The definition of energy, in thermodynamics, is dependent by starting operative definitions of the basic concepts of physics on which it rests, such as those of isolated systems, ambient of a system, separable system and set of separable states. Then the definition of energy is rigorously extended to open systems. The extension gives a clear physical meaning to the concept of energy difference between two states with arbitrary different compositions
Water adsorption isotherms and thermodynamic properties of cassava bagasse
Energy Technology Data Exchange (ETDEWEB)
Polachini, Tiago Carregari, E-mail: tiagopolachini@terra.com.br; Betiol, Lilian Fachin Leonardo; Lopes-Filho, José Francisco; Telis-Romero, Javier
2016-05-20
Highlights: • Adsorption isotherms and composition of cassava bagasse were determined. • GAB equation was the best-fitted model to sorption data of type II isotherm. • Isosteric heat of sorption was calculated in a range of equilibrium moisture content. • Differential enthalpy and entropy confirmed the isokinetic compensation theory. • Water adsorption by cassava bagasse is considered an enthalpy driven process. - Abstract: Losses of food industry are generally wet products that must be dried to posterior use and storage. In order to optimize drying processes, the study of isotherms and thermodynamic properties become essential to understand the water sorption mechanisms of cassava bagasse. For this, cassava bagasse was chemically analyzed and had its adsorption isotherms determined in the range of 293.15–353.15 K through the static gravimetric method. The models of GAB, Halsey, Henderson, Oswin and Peleg were fitted, and best adjustments were found for GAB model with R{sup 2} > 0.998 and no pattern distribution of residual plots. Isosteric heat of adsorption and thermodynamic parameters could be determined as a function of moisture content. Compensation theory was confirmed, with linear relationship between enthalpy and entropy and higher values of isokinetic temperature (T{sub B} = 395.62 K) than harmonic temperature. Water adsorption was considered driven by enthalpy, clarifying the mechanisms of water vapor sorption in cassava bagasse.
Size- and dimensionality-dependent thermodynamic properties of ice nanocrystals.
Han, Y Y; Shuai, J; Lu, H M; Meng, X K
2012-02-09
Although the melting of ice is the most ubiquitous phase transition, (pre)melting and the quasi-liquid layer remain a matter of debate, and little is known about the relationship between the thermodynamic properties of ice nanocrystals and their size and dimensionality. Here, we model analytically the size- and dimensionality-dependent melting temperature, premelting temperature, and melting enthalpy of hydrogen-bonded ice nanocrystals. These three thermodynamic parameters are found to increase with increasing size and dimensionality where the size effect is principle while the dimensionality effect is secondary, and the size dependence of premelting temperature almost follows the same trend as that of melting temperature. The model predictions correspond to the available molecular dynamic simulation and experimental results of ice nanoparticles and nanowires. These agreements enable us to determine theoretically the thickness of the quasi-liquid layer for the first time, which is found to be not constant but slightly increase with increasing size and thus accounts for the occurrence of different reported thicknesses of the quasi-liquid layer. © 2012 American Chemical Society
Thermodynamic properties for polycyclic systems by non-calorimetric methods
Energy Technology Data Exchange (ETDEWEB)
Steele, W.V.; Chirico, R.D.; Klots, T.D.
1993-03-01
A detailed vibrational spectroscopic study of furan, pyrrole, and thiophene has been completed. These compounds form part of the base of five-membered ring systems on which the rest of the research program will be built Several methyl-substituted derivatives were also studied. The results will be used to confirm the model for alkyl- substitution in the ring systems. Gas-phase spectra and fundamental- frequency assignments were completed for 2,3- and 2,5-dihydrofuran. Those compounds initiate work on ring-puckering within the research program. A paper describing the need for third virial estimation, when using the virial equation of state to derive thermodynamic properties at pressures greater than 1 bar was completed.
Thermodynamic properties of Kagome antiferromagnets with different perturbations
Energy Technology Data Exchange (ETDEWEB)
Singh, Rajiv R P [University of California, Davis, CA 95616 (United States); Rigol, Marcos, E-mail: singh@physics.ucdavis.ed [Georgetown University, 37th and O St NW, Washington, DC 20057 (United States)
2009-01-01
We discuss the results of several small perturbations to the thermodynamic properties of Kagome Lattice Heisenberg Model (KLHM) at high and intermediate temperatures, including Curie impurities, dilution, in-plane and out of plane Dzyaloshinski-Moria (DM) anisotropies and exchange anisotropy. We examine the combined role of Curie impurities and dilution in the behavior of uniform susceptibility. We also study the changes in specific heat and entropy with various anisotropies. Their relevance to newly discovered materials ZnCu{sub 3}(OH){sub 6}Cl{sub 2} is explored. We find that the magnetic susceptibility is well described by about 6 percent impurity and dilution. We also find that the entropy difference between the material and KLHM is well described by the DM parameter D{sub z}/J{approx}0:1.
Czech Academy of Sciences Publication Activity Database
Kroupa, Aleš
2013-01-01
Roč. 66, JAN (2013), s. 3-13 ISSN 0927-0256 R&D Projects: GA MŠk(CZ) OC08053 Institutional support: RVO:68081723 Keywords : Calphad method * phase diagram modelling * thermodynamic database development Subject RIV: BJ - Thermodynamics Impact factor: 1.879, year: 2013
ms2: A molecular simulation tool for thermodynamic properties
Deublein, Stephan; Eckl, Bernhard; Stoll, Jürgen; Lishchuk, Sergey V.; Guevara-Carrion, Gabriela; Glass, Colin W.; Merker, Thorsten; Bernreuther, Martin; Hasse, Hans; Vrabec, Jadran
2011-11-01
This work presents the molecular simulation program ms2 that is designed for the calculation of thermodynamic properties of bulk fluids in equilibrium consisting of small electro-neutral molecules. ms2 features the two main molecular simulation techniques, molecular dynamics (MD) and Monte-Carlo. It supports the calculation of vapor-liquid equilibria of pure fluids and multi-component mixtures described by rigid molecular models on the basis of the grand equilibrium method. Furthermore, it is capable of sampling various classical ensembles and yields numerous thermodynamic properties. To evaluate the chemical potential, Widom's test molecule method and gradual insertion are implemented. Transport properties are determined by equilibrium MD simulations following the Green-Kubo formalism. ms2 is designed to meet the requirements of academia and industry, particularly achieving short response times and straightforward handling. It is written in Fortran90 and optimized for a fast execution on a broad range of computer architectures, spanning from single processor PCs over PC-clusters and vector computers to high-end parallel machines. The standard Message Passing Interface (MPI) is used for parallelization and ms2 is therefore easily portable to different computing platforms. Feature tools facilitate the interaction with the code and the interpretation of input and output files. The accuracy and reliability of ms2 has been shown for a large variety of fluids in preceding work. Program summaryProgram title:ms2 Catalogue identifier: AEJF_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Special Licence supplied by the authors No. of lines in distributed program, including test data, etc.: 82 794 No. of bytes in distributed program, including test data, etc.: 793 705 Distribution format: tar.gz Programming language: Fortran90 Computer: The
Thermodynamic Property Model of Wide-Fluid Phase Propane
Directory of Open Access Journals (Sweden)
I Made Astina
2007-05-01
Full Text Available A new thermodynamic property model for propane is expressed in form of the Helmholtz free energy function. It consists of eight terms of the ideal-gas part and eighteen terms of the residual part. Accurate experimental data of fluid properties and theoretical approach from the intermolecular potential were simultaneously considered in the development to insure accuracy and to improve reliability of the equation of state over wide range of pressures and temperatures. Based on the state range of experimental data used in the model development, the validity range is judged from the triple-point of 85.48 K to temperature of 450 K and pressure up to 60 MPa. The uncertainties with respect to different properties are estimated to be 0.03% in ideal-gas isobaric specific heat, 0.2% in liquid phase density, 0.3% in gaseous phase density 1% in specific heats, 0.1% in vapor-pressure except at very low temperatures, 0.05% in saturated-liquid density, 0.02% in speed of sound of the gaseous phase and 1% in speed of sound of the liquid phase.
Ideal gas thermodynamic properties for the phenyl, phenoxy, and o-biphenyl radicals
Burcat, A.; Zeleznik, F. J.; Mcbride, B. J.
1985-01-01
Ideal gas thermodynamic properties of the phenyl and o-biphenyl radicals, their deuterated analogs and the phenoxy radical were calculated to 5000 K using estimated vibrational frequencies and structures. The ideal gas thermodynamic properties of benzene, biphenyl, their deuterated analogs and phenyl were also calculated.
International Nuclear Information System (INIS)
Shpil'rain, E.E.; Yakimovich, K.A.
1981-01-01
The paper reviews briefly experimental determinations of thermodynamic properties of the LiH-Li system. Relationships fitted to the experimental data are presented and discussed, with the aim of determining a consistent set of thermodynamic properties (enthalpy, heat capacity) for the systems Li-(LiH, LiD, LiT) in the solid state and in the melt. (author)
Optimization of the thermodynamic properties and phase diagrams of P2O5-containing systems
Hudon, Pierre; Jung, In-Ho
2014-05-01
P2O5 is an important oxide component in the late stage products of numerous igneous rocks such as granites and pegmatites. Typically, P2O5 combines with CaO and crystallizes in the form of apatite, while in volatile-free conditions, Ca-whitlockite is formed. In spite of their interest, the thermodynamic properties and phase diagrams of P2O5-containg systems are not well known yet. In the case of the pure P2O5 for example, no experimental thermodynamic data are available for the liquid and the O and O' solid phases. As a result, we re-evaluated all the thermodynamic and phase diagram data of the P2O5 unary system [1]. Optimization of the thermodynamic properties and phase diagrams of the binary P2O5 systems was then performed including the Li2O-, Na2O-, MgO-, CaO-, BaO-, MnO-, FeO-, Fe2O3-, ZnO-, Al2O3-, and SiO2-P2O5 [2] systems. All available thermodynamic and phase equilibrium data were simultaneously reproduced in order to obtain a set of model equations for the Gibbs energies of all phases as functions of temperature and composition. In particular, the Gibbs energy of the liquid solution was described using the Modified Quasichemical Model [3-5] implemented in the FactSage software [6]. Thermodynamic modeling of the Li2O-Na2O-K2O-MgO-CaO-FeO-Fe2O3-Al2O3-SiO2 system, which include many granite-forming minerals such as nepheline, leucite, pyroxene, melilite, feldspar and spinel is currently in progress. [1] Jung, I.-H., Hudon, P. (2012) Thermodynamic assessment of P2O5. J. Am. Ceram. Soc., 95 (11), 3665-3672. [2] Rahman, M., Hudon, P. and Jung, I.-H. (2013) A coupled experimental study and thermodynamic modeling of the SiO2-P2O5 system. Metall. Mater. Trans. B, 44 (4), 837-852. [3] Pelton, A.D. and Blander, M. (1984) Computer-assisted analysis of the thermodynamic properties and phase diagrams of slags. Proc. AIME Symp. Metall. Slags Fluxes, TMS-AIME, 281-294. [4] Pelton, A.D. and Blander, M. (1986) Thermodynamic analysis of ordered liquid solutions by a modified
THEWASP library. Thermodynamic water and steam properties library in GPU
International Nuclear Information System (INIS)
Waintraub, M.; Lapa, C.M.F.; Mol, A.C.A.; Heimlich, A.
2011-01-01
In this paper we present a new library for thermodynamic evaluation of water properties, THEWASP. This library consists of a C++ and CUDA based programs used to accelerate a function evaluation using GPU and GPU clusters. Global optimization problems need thousands of evaluations of the objective functions to nd the global optimum implying in several days of expensive processing. This problem motivates to seek a way to speed up our code, as well as to use MPI on Beowulf clusters, which however increases the cost in terms of electricity, air conditioning and others. The GPU based programming can accelerate the implementation up to 100 times and help increase the number of evaluations in global optimization problems using, for example, the PSO or DE Algorithms. THEWASP is based on Water-Steam formulations publish by the International Association for the properties of water and steam, Lucerne - Switzerland, and provides several temperature and pressure function evaluations, such as specific heat, specific enthalpy, specific entropy and also some inverse maps. In this study we evaluated the gain in speed and performance and compared it a CPU based processing library. (author)
Systemic analysis of thermodynamic properties of lanthanide halides
International Nuclear Information System (INIS)
Mirsaidov, U.; Badalov, A.; Marufi, V.K.
1992-01-01
System analysis of thermodynamic characteristics of lanthanide halides was carried out. A method making allowances for the influence of spin and orbital moments of momentum of the main states of lanthanide trivalent ions in their natural series was employed. Unknown in literature thermodynamic values were calculated and corrected for certain compounds. The character of lanthanide halide thermodynamic parameter change depending on ordinal number of the metals was ascertained. Pronouncement of tetrad-effect in series of compounds considered was pointed out
Iordanov, Tzvetelin D; Schenter, Gregory K; Garrett, Bruce C
2006-01-19
A sensitivity analysis of bulk water thermodynamics is presented in an effort to understand the relation between qualitative features of molecular potentials and properties that they predict. The analysis is incorporated in molecular dynamics simulations and investigates the sensitivity of the Helmholtz free energy, internal energy, entropy, heat capacity, pressure, thermal pressure coefficient, and static dielectric constant to components of the potential rather than the parameters of a given functional form. The sensitivities of the properties are calculated with respect to the van der Waals repulsive and the attractive parts, plus short- and long-range Coulomb parts of three four site empirical water potentials: TIP4P, Dang-Chang and TTM2R. The polarization sensitivity is calculated for the polarizable Dang-Chang and TTM2R potentials. This new type of analysis allows direct comparisons of the sensitivities for different potentials that use different functional forms. The analysis indicates that all investigated properties are most sensitive to the van der Waals repulsive, the short-range Coulomb and the polarization components of the potentials. When polarization is included in the potentials, the magnitude of the sensitivity of the Helmholtz free energy, internal energy, and entropy with respect to this part of the potential is comparable in magnitude to the other electrostatic components. In addition similarities in trends of observed sensitivities for nonpolarizable and polarizable potentials lead to the conclusion that the complexity of the model is not of critical importance for the calculation of these thermodynamic properties for bulk water. The van der Waals attractive and the long-range Coulomb sensitivities are relatively small for the entropy, heat capacity, thermal pressure coefficient and the static dielectric constant, while small changes in any of the potential contributions will significantly affect the pressure. The analysis suggests a procedure
Generalizing thermodynamic properties of bulk single-walled carbon nanotubes
Directory of Open Access Journals (Sweden)
Kenneth R. Rodriguez
2014-12-01
Full Text Available The enthalpy and Gibbs free energy thermodynamical potentials of single walled carbon nanotubes were studied of all types (armchairs, zig-zags, chirals (n>m, and chiral (n
Critical, statistical, and thermodynamical properties of lattice models
Energy Technology Data Exchange (ETDEWEB)
Varma, Vipin Kerala
2013-10-15
In this thesis we investigate zero temperature and low temperature properties - critical, statistical and thermodynamical - of lattice models in the contexts of bosonic cold atom systems, magnetic materials, and non-interacting particles on various lattice geometries. We study quantum phase transitions in the Bose-Hubbard model with higher body interactions, as relevant for optical lattice experiments of strongly interacting bosons, in one and two dimensions; the universality of the Mott insulator to superfluid transition is found to remain unchanged for even large three body interaction strengths. A systematic renormalization procedure is formulated to fully re-sum these higher (three and four) body interactions into the two body terms. In the strongly repulsive limit, we analyse the zero and low temperature physics of interacting hard-core bosons on the kagome lattice at various fillings. Evidence for a disordered phase in the Ising limit of the model is presented; in the strong coupling limit, the transition between the valence bond solid and the superfluid is argued to be first order at the tip of the solid lobe.
Critical, statistical, and thermodynamical properties of lattice models
International Nuclear Information System (INIS)
Varma, Vipin Kerala
2013-10-01
In this thesis we investigate zero temperature and low temperature properties - critical, statistical and thermodynamical - of lattice models in the contexts of bosonic cold atom systems, magnetic materials, and non-interacting particles on various lattice geometries. We study quantum phase transitions in the Bose-Hubbard model with higher body interactions, as relevant for optical lattice experiments of strongly interacting bosons, in one and two dimensions; the universality of the Mott insulator to superfluid transition is found to remain unchanged for even large three body interaction strengths. A systematic renormalization procedure is formulated to fully re-sum these higher (three and four) body interactions into the two body terms. In the strongly repulsive limit, we analyse the zero and low temperature physics of interacting hard-core bosons on the kagome lattice at various fillings. Evidence for a disordered phase in the Ising limit of the model is presented; in the strong coupling limit, the transition between the valence bond solid and the superfluid is argued to be first order at the tip of the solid lobe.
Structure and thermodynamic properties of molten alkali chlorides
International Nuclear Information System (INIS)
Ballone, P.; Pastore, G.; Tosi, M.P.; Trieste Univ.
1984-03-01
Self-consistent calculations of partial pair distribution functions and thermodynamic properties are presented for molten alkali chlorides in a non-polarizable-ion model. The theory starts from the hypernetted chain approximation and analyzes the role of bridge diagrams both for a two-component ionic plasma on a neutralizing background and for a binary ionic liquid of cations and anions. A simple account of excluded-volume effects suffices for a good description of the pair distribution functions in the two-component plasma, in analogy with earlier work on one-component fluids. The interplay of Coulomb attractions and repulsions in the molten salt requires, on the other hand, the inclusion of (i) excluded-volume effects for the various ion pairs as in a mixture of hard spheres with non-additive radii and (ii) medium-range Coulomb effects reflected mainly in the like-ion correlations. All these effects are included approximately in an empirical evaluation of the bridge functions, with numerical results which compare very well with computer simulation data. A detailed discussion of the results against experimental structural data is then given in the case of molten sodium chloride. (author)
Thermodynamic properties and drying kinetics of Bauhinia forficata Link leaves
Directory of Open Access Journals (Sweden)
Fernanda P. da Silva
Full Text Available ABSTRACT The aim of this study was to determine the effective diffusion coefficient and the thermodynamic properties of Bauhinia forficata Link leaves, considering two forms of thickness measurements and to describe the process by fitting mathematical models. The leaves were collected, taken to the laboratory and prepared to start the drying process in which four temperatures (40, 50, 60 and 70 °C were applied. After the drying process, the effective diffusion coefficient was determined through the theory of diffusion in liquid, allowing to obtain the values of the activation energy, enthalpy, entropy and Gibbs free energy. The description of the drying process was performed by setting the thirteen mathematical models used to represent constant drying of agricultural products. The Valcam model was selected to represent the drying kinetics B. forficata Link. Increased temperature promotes: decreasing enthalpy and entropy; increasing Gibbs free energy and effective diffusion coefficient. The effective diffusion coefficient is higher when the rib thickness is considered; thus, it is recommended to standardize and/or specify the points of measurement of leaf thickness.
Moisture sorption isotherms and thermodynamic properties of bovine leather
Fakhfakh, Rihab; Mihoubi, Daoued; Kechaou, Nabil
2018-04-01
This study was aimed at the determination of bovine leather moisture sorption characteristics using a static gravimetric method at 30, 40, 50, 60 and 70 °C. The curves exhibit type II behaviour according to the BET classification. The sorption isotherms fitting by seven equations shows that GAB model is able to reproduce the equilibrium moisture content evolution with water activity for moisture range varying from 0.02 to 0.83 kg/kg d.b (0.9898 thermodynamic properties such as isosteric heat of sorption, sorption entropy, spreading pressure, net integral enthalpy and entropy. Net isosteric heat of sorption and differential entropy were evaluated through direct use of moisture isotherms by applying the Clausius-Clapeyron equation and used to investigate the enthalpy-entropy compensation theory. Both sorption enthalpy and entropy for desorption increase to a maximum with increasing moisture content, and then decrease sharply with rising moisture content. Adsorption enthalpy decreases with increasing moisture content. Whereas, adsorption entropy increases smoothly with increasing moisture content to a maximum of 6.29 J/K.mol. Spreading pressure increases with rising water activity. The net integral enthalpy seemed to decrease and then increase to become asymptotic. The net integral entropy decreased with moisture content increase.
Hrubý Jan; Duška Michal
2014-01-01
We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated) and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics e...
Synthesis, Properties and Mineralogy of Important Inorganic Materials
DEFF Research Database (Denmark)
Warner, Terence Edwin
-specialists, who are interested in learning more about how technological ceramic materials and artificial minerals are made. Finally, the author assumes that the reader is familiar with the basic principles and concepts of materials chemistry (or at least has access to such knowledge), such as; thermodynamic......The synthesis of high quality material is an essential step in the process of obtaining meaningful information about the material’s properties, and therefore, is an important link between physics and chemistry. Semiconductors; superconductors; solid-electrolytes; glasses; pigments; dielectric......? This book attempts to address this problem by offering the reader clear and detailed descriptions on how to prepare a selection of fifteen inorganic materials that exhibit important optical, magnetic, electrical and thermal properties; on a laboratory scale. The materials and chemical syntheses have been...
Thermodynamic properties of UF sub 6 measured with a ballistic piston compressor
Sterritt, D. E.; Lalos, G. T.; Schneider, R. T.
1973-01-01
From experiments performed with a ballistic piston compressor, certain thermodynamic properties of uranium hexafluoride were investigated. Difficulties presented by the nonideal processes encountered in ballistic compressors are discussed and a computer code BCCC (Ballistic Compressor Computer Code) is developed to analyze the experimental data. The BCCC unfolds the thermodynamic properties of uranium hexafluoride from the helium-uranium hexafluoride mixture used as the test gas in the ballistic compressor. The thermodynamic properties deduced include the specific heat at constant volume, the ratio of specific heats for UF6, and the viscous coupling constant of helium-uranium hexafluoride mixtures.
Nadi, Fatemeh; Tzempelikos, Dimitrios
2018-01-01
In this work, apples of cv. Golden Delicious were cut into slices that were 5 and 7 mm thick and then vacuum dried at 50, 60 and 70 °C and pressure of 0.02 bar. The thin layer model drying kinetics was studied, and mass transfer properties, specifically effective moisture diffusivity and convective mass transfer coefficient, were evaluated using the Fick's equation of diffusion. Also, thermodynamic parameters of the process, i.e. enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG), were determined. Colour properties were evaluated as one of the important indicators of food quality and marketability. Determination of mass transfer parameters and thermodynamic properties of vacuum dried apple slices has not been discussed much in the literature. In conclusion, the Nadi's model fitted best the observed data that represent the drying process. Thermodynamic properties were determined based on the dependence of the drying constant of the Henderson and Pabis model on temperature, and it was concluded that the variation in drying kinetics depends on the energy contribution of the surrounding environment. The enthalpy and entropy diminished, while the Gibbs free energy increased with the increase of the temperature of drying; therefore, it was possible to verify that variation in the diffusion process in the apple during drying depends on energetic contributions of the environment. The obtained results showed that diffusivity increased for 69%, while the mass transfer coefficient increase was even higher, 75%, at the variation of temperature of 20 °C. The increase in the dimensionless Biot number was 20%.
Mass spectrometric determination of the thermodynamic excess properties of ternary Fe-Co-Cr melts
International Nuclear Information System (INIS)
Schmidt, Harald; Tomiska, Josef
2004-01-01
Computer-aided Knudsen cell mass spectrometry is used for the thermodynamic investigations on ternary Fe-Co-Cr melts over the entire range of composition. The thermodynamic mixing behavior has been determined by means of the 'digital intensity-ratio' (DIR) method. The ternary thermodynamically adapted power (TAP) series concept is used for the algebraic representation of the molar excess properties. The corresponding TAP parameters, and the values of the molar excess quantities Z E (T, x) (Z is the Gibbs energy G, heat of mixing H, entropy S) as well as the thermodynamic activities of all three constituents at 1950 K are presented
Computer codes used in the calculation of high-temperature thermodynamic properties of sodium
Energy Technology Data Exchange (ETDEWEB)
Fink, J.K.
1979-12-01
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 vaporization, density, volumetric thermal expansion coefficient, compressibility, and thermal pressure coefficient. In the code SODIPROP, these properties are calculated for saturated and subcooled liquid sodium. Thermodynamic properties of saturated sodium vapor are calculated in the code NAVAPOR. The code NASUPER calculates thermodynamic properties for super-heated sodium vapor only for low (< 1644 K) temperatures. No calculations were made for the supercritical region.
Computer codes used in the calculation of high-temperature thermodynamic properties of sodium
International Nuclear Information System (INIS)
Fink, J.K.
1979-12-01
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 vaporization, density, volumetric thermal expansion coefficient, compressibility, and thermal pressure coefficient. In the code SODIPROP, these properties are calculated for saturated and subcooled liquid sodium. Thermodynamic properties of saturated sodium vapor are calculated in the code NAVAPOR. The code NASUPER calculates thermodynamic properties for super-heated sodium vapor only for low (< 1644 K) temperatures. No calculations were made for the supercritical region
Electrolytes: transport properties and non-equilibrium thermodynamics
International Nuclear Information System (INIS)
Miller, D.G.
1980-12-01
This paper presents a review on the application of non-equilibrium thermodynamics to transport in electrolyte solutions, and some recent experimental work and results for mutual diffusion in electrolyte solutions
Electronic and thermodynamic properties of transition metal elements and compounds
International Nuclear Information System (INIS)
Haeglund, J.
1993-01-01
This thesis focuses on the use of band-structure calculations for studying thermodynamic properties of solids. We discuss 3d-, 4d- and 5d-transition metal carbides and nitrides. Through a detailed comparison between theoretical and experimental results, we draw conclusions on the character of the atomic bonds in these materials. We show how electronic structure calculations can be used to give accurate predictions for bonding energies. Part of the thesis is devoted to the application of the generalized gradient approximation in electronic structure calculations on transition metals. For structures with vibrational disorder, we present a method for calculating averaged phonon frequencies without using empirical information. For magnetic excitations, we show how a combined use of theoretical results and experimental data can yield information on magnetic fluctuations at high temperatures. The main results in the thesis are: Apart for an almost constant shift, theoretically calculated bonding energies for transition metal carbides and nitrides agree with experimental data or with values from analysis of thermochemical information. The electronic spectrum of transition metal carbides and nitrides can be separated into bonding, antibonding and nonbonding electronic states. The lowest enthalpy of formation for substoichiometric vanadium carbide VC 1-X at zero temperature and pressure occurs for a structure containing vacancies (x not equal to 0). The generalized gradient approximation improves theoretical calculated cohesive energies for 3d-transition metals. Magnetic phase transitions are sensitive to the description of exchange-correlation effects in electronic structure calculations. Trends in Debye temperatures can be successfully analysed in electronic structure calculations on disordered lattices. For the elements, there is a clear dependence on the crystal structure (e.g., bcc, fcc or hcp). Chromium has fluctuating local magnetic moments at temperatures well above
Thermodynamic properties and energy characteristics of water+1-propanol
Alhasov, A. B.; Bazaev, A. R.; Bazaev, E. A.; Osmanova, B. K.
2017-11-01
By using own precise experimental data on p,ρ,T,x- relations differential and integral thermodynamic properties of water+1-propanol homogeneous binary mixtures (0.2, 0.5, and 0.8 mole fractions of 1-propanol) were obtained in one phase (liquid, vapor) region, along coexistence curve phase, at critical and supercritical regions of parameters of state. These values were obtained in the regions of temperatures 373.15 - 673.15 K, densities 3 - 820 kg/m3 and pressures up to 50 MPa. It is found that shape of p,ρ,T,- dependences of water+1-propanol mixtures in investigated range of temperatures is the same with those of pure liquid, but the pressure of the mixture is higher than those of pure water or 1-propanol. The critical line of water+1-propanol binary mixtures as opposed to those of water+methanol and water+ethanol mixtures has convex shape. It is ascertained that using water+1-propanol mixture (0.2 mol.fraction of 1-propanol) instead of pure water allows to decrease lower limit of operating temperatures to 50 K, to increase effective coefficient of efficiency and partially unify thermal mechanical equipment of power plant. Our comparative energy analysis of cycles of steam-turbine plant on water and water+1- propanol mixtures, carried out at the same thermobaric conditionsand showed that thermal coefficient of efficiencyofcycle of steam-turbine plant onwater+1-propanol mixture (0.2 mol.fraction of 1-propanol) is higher than those of pure water.Thus and so we made a conclusion about usability of water+1-propanol mixture (0.2 mole fraction of 1-propanol) as a working substance of steam-turbine plant cycle.
International Nuclear Information System (INIS)
Gurvich, L.V.; Bergman, G.A.; Gorokhov, L.N.; Iorish, V.S.; Leonidov, V.Y.; Yungman, V.S.
1997-01-01
The data on thermodynamic and molecular properties of the potassium, rubidium and cesium hydroxides have been collected, critically reviewed, analyzed, and evaluated. Tables of the thermodynamic properties [C p circ , Φ=-(G -H(0)/T, S, H -H(0), Δ f H, Δ f G)] of these hydroxides in the condensed and gaseous states have been calculated using the results of the analysis and some estimated values. The recommendations are compared with earlier evaluations given in the JANAF Thermochemical Tables and Thermodynamic Properties of Individual Substances. The properties considered are: the temperature and enthalpy of phase transitions and fusion, heat capacities, spectroscopic data, structures, bond energies, and enthalpies of formation at 298.15 K. The thermodynamic functions in solid, liquid, and gaseous states are calculated from T=0 to 2000 K for substances in condensed phase and up to 6000 K for gases. copyright 1997 American Institute of Physics and American Chemical Society
Structure and thermodynamic properties of relativistic electron gases.
Liu, Yu; Wu, Jianzhong
2014-07-01
Relativistic effect is important in many quantum systems but theoretically complicated from both fundamental and practical perspectives. Herein we introduce an efficient computational procedure to predict the structure and energetic properties of relativistic quantum systems by mapping the Pauli principle into an effective pairwise-additive potential such that the properties of relativistic nonquantum systems can be readily predicted from conventional liquid-state methods. We applied our theoretical procedure to relativistic uniform electron gases and compared the pair correlation functions with those for systems of nonrelativistic electrons. A simple analytical expression has been developed to correlate the exchange-correlation free energy of relativistic uniform electron systems.
Naden, Levi N.; Shirts, Michael R.
2015-01-01
We show how thermodynamic properties of molecular models can be computed over a large, multidimensional parameter space by combining multistate reweighting analysis with a linear basis function approach. This approach reduces the computational cost to estimate thermodynamic properties from molecular simulations for over 130,000 tested parameter combinations from over a thousand CPU years to tens of CPU days. This speed increase is achieved primarily by computing the potential energy as a line...
Equilibrium properties in the thermodynamic limit from small-sized molecular dynamics simulations
Cortes-Huerto, Robinson; Kremer, Kurt; Potestio, Raffaello
We present an accurate and efficient method to obtain equilibrium thermodynamic properties of bulk systems from small-sized molecular dynamics simulations by introducing finite size effects into integral equations of statistical mechanics. We validate the method by calculating thermodynamic properties of prototypical complex mixtures such as the activity coefficients of aqueous urea mixtures and the Kirkwood-Buff integrals of Lennard-Jones fluids. Moreover, our results demonstrate how to identify simulation conditions under which computer simulations reach the thermodynamic limit. Alexander von Humboldt Foundation.
Predictions of titanium alloy properties using thermodynamic modeling tools
Zhang, F.; Xie, F.-Y.; Chen, S.-L.; Chang, Y. A.; Furrer, D.; Venkatesh, V.
2005-12-01
Thermodynamic modeling tools have become essential in understanding the effect of alloy chemistry on the final microstructure of a material. Implementation of such tools to improve titanium processing via parameter optimization has resulted in significant cost savings through the elimination of shop/laboratory trials and tests. In this study, a thermodynamic modeling tool developed at CompuTherm, LLC, is being used to predict β transus, phase proportions, phase chemistries, partitioning coefficients, and phase boundaries of multicomponent titanium alloys. This modeling tool includes Pandat, software for multicomponent phase equilibrium calculations, and PanTitanium, a thermodynamic database for titanium alloys. Model predictions are compared with experimental results for one α-β alloy (Ti-64) and two near-β alloys (Ti-17 and Ti-10-2-3). The alloying elements, especially the interstitial elements O, N, H, and C, have been shown to have a significant effect on the β transus temperature, and are discussed in more detail herein.
Thermodynamic properties of static and rotating unparticle black holes
Alencar, G.; Muniz, C. R.
2018-03-01
In this paper we find analytical expressions for thermodynamic quantities of scalar (tensor) and vector unparticle static black holes. We also find rotating solutions to these systems and analyse their thermodynamics. First we consider the static case with a spherically symmetric source for both the vector and scalar (tensor) unparticles. We obtain thus analytical expressions to the principal thermodynamic quantities: Hawking temperature, entropy, heat capacity and free energy. For the scalar (tensor) case we find that the black hole presents a residual value for the entropy when its radius goes to zero but the other thermodynamic quantities give, for any horizon radius, a thermodynamically unstable behavior similar to the standard black hole. For the vector case we find a richer structure in the region in which the horizon radius is less than the characteristic length of the unparticle theory. We identify a phase transition and a region where the black hole can be thermodynamically stable. Following, we show that the mentioned modifications in the standard gravity are formally similar to those ones present in the black holes with quintessence. With this we also show, notwithstanding, that the unparticles cannot be a source of quintessence. By using this similarity we find two different rotating solutions to the unparticle black holes based on works by Ghosh and Toshmatov et al.. For both cases we compute the Hawking temperature and in the ungravity dominated regime we find, as in the static cases, a fractalization of the event horizon. For the Gosh-like solution the fractal dimension depends on the polar angle and on the rotation of the source. For the Toshmatov-like one it is equal to the static case and therefore the fractalization is not dependent on the rotation of the source.
Thermodynamics properties of diatomic molecules with general molecular potential
Ikot, Akpan N.; Chukwuocha, E. O.; Onyeaju, M. C.; Onate, C. A.; Ita, B. I.; Udoh, M. E.
2018-02-01
In this paper, the energy spectra of the general molecular potential are obtained using the asymptotic iteration method within the framework of non-relativistic quantum mechanics.With the energy spectrum obtained, the vibrational partition function is calculated in a closed form and is used to obtain an expression for other thermodynamic functions such as vibrational mean energy U, vibrational mean free energy F, vibrational entropy S and vibrational specific heat capacity C. These thermodynamic functions are studied for the electronic state X1Σ _g^+ of K_2 diatomic molecules.
International Nuclear Information System (INIS)
McKenzie, W.F.
1992-08-01
The thermodynamic properties of secondary phases observed to form during nuclear waste glass-water interactions are of particular interest as it is with the application of these properties together with the thermodynamic properties of other solid phases, fluid phases, and aqueous species that one may predict the environmental consequences of introducing radionuclides contained in the glass into groundwater at a high-level nuclear waste repository. The validation of these predicted consequences can be obtained from laboratory experiments and field observations at natural analogue sites. The purpose of this report is to update and expand the previous compilation (McKenzie, 1991) of thermodynamic data retrieved from the literature and/or estimated for secondary phases observed to form (and candidate phases from observed chemical compositions) during nuclear waste glass-water interactions. In addition, this report includes provisionally recommended thermodynamic data of secondary phases
International Nuclear Information System (INIS)
Du, Jianping; Zhao, Ruihua; Xue, Yongqiang
2012-01-01
Highlights: ► There is an obvious influence of the size on thermodynamic properties for the reaction referring nano-reactants. ► Gibbs function, enthalpy, entropy and equilibrium constant are dependent on the reactant size. ► There is an approximate linear relation between them. - Abstract: The theoretical relations of thermodynamic properties, the equilibrium constant and reactant size in nanosystem are described. The effects of size on thermodynamic properties and the equilibrium constant were studied using nanosize zinc oxide and sodium bisulfate solution as a reaction system. The experimental results indicated that the molar Gibbs free energy, the molar enthalpy and the molar entropy of the reaction decrease, but the equilibrium constant increases with decreasing reactant size. Linear trends were observed between the reciprocal of size for nano-reactant and thermodynamic variable, which are consistent with the theoretical relations.
Musari, A. A.; Orukombo, S. A.
2018-03-01
Barium chalcogenides are known for their high-technological importance and great scientific interest. Detailed studies of their elastic, mechanical, dynamical and thermodynamic properties were carried out using density functional theory and plane-wave pseudo potential method within the generalized gradient approximation. The optimized lattice constants were in good agreement when compared with experimental data. The independent elastic constants, calculated from a linear fit of the computed stress-strain function, were used to determine the Young’s modulus (E), bulk modulus (B), shear modulus (G), Poisson’s ratio (σ) and Zener’s anisotropy factor (A). Also, the Debye temperature and sound velocities for barium chalcogenides were estimated from the three independent elastic constants. The calculations of phonon dispersion showed that there are no negative frequencies throughout the Brillouin zone. Hence barium chalcogenides have dynamically stable NaCl-type crystal structure. Finally, their thermodynamic properties were calculated in the temperature range of 0-1000 K and their constant-volume specific heat capacities at room-temperature were reported.
Thermodynamic properties of Ag–Au–Hg solid solutions
Energy Technology Data Exchange (ETDEWEB)
Chudnenko, Konstantin, E-mail: chud@igc.irk.ru [Vinogradov Institute of Geochemistry, Siberian Branch of Russian Academy of Sciences, Irkutsk 664033 (Russian Federation); Pal’yanova, Galina [Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation)
2013-11-20
Highlights: • The natural data in the Ag–Au–Hg ternary system have been summarized. • Standard thermodynamic functions of Au{sub x1}Ag{sub x2}Hg{sub x3} solid solution have been calculated. • The obtained data can be used for developing models processes with Au, Ag and Hg. - Abstract: We have summarized data on natural Ag–Au amalgams. Standard thermodynamic functions of ternary Ag–Au–Hg solid solution in the system were estimated. Several thermodynamic models of solid solutions were constructed on the basis of data on boundary binary systems. The convergence of results for different models suggests the validity of prediction. The obtained data can be used in different software packages and thermodynamic databases for developing physicochemical models in technological processes with participation of gold, silver and mercury. It will be used for modeling of ore deposit formation taking account of subregular solid solutions in a wide T, P-parameters interval.
Thermodynamic properties for applications in chemical industry via classical force fields.
Guevara-Carrion, Gabriela; Hasse, Hans; Vrabec, Jadran
2012-01-01
Thermodynamic properties of fluids are of key importance for the chemical industry. Presently, the fluid property models used in process design and optimization are mostly equations of state or G (E) models, which are parameterized using experimental data. Molecular modeling and simulation based on classical force fields is a promising alternative route, which in many cases reasonably complements the well established methods. This chapter gives an introduction to the state-of-the-art in this field regarding molecular models, simulation methods, and tools. Attention is given to the way modeling and simulation on the scale of molecular force fields interact with other scales, which is mainly by parameter inheritance. Parameters for molecular force fields are determined both bottom-up from quantum chemistry and top-down from experimental data. Commonly used functional forms for describing the intra- and intermolecular interactions are presented. Several approaches for ab initio to empirical force field parameterization are discussed. Some transferable force field families, which are frequently used in chemical engineering applications, are described. Furthermore, some examples of force fields that were parameterized for specific molecules are given. Molecular dynamics and Monte Carlo methods for the calculation of transport properties and vapor-liquid equilibria are introduced. Two case studies are presented. First, using liquid ammonia as an example, the capabilities of semi-empirical force fields, parameterized on the basis of quantum chemical information and experimental data, are discussed with respect to thermodynamic properties that are relevant for the chemical industry. Second, the ability of molecular simulation methods to describe accurately vapor-liquid equilibrium properties of binary mixtures containing CO(2) is shown.
Thermodynamic properties of poly(phenylene-pyridyl) dendrons of the second and the third generations
International Nuclear Information System (INIS)
Smirnova, Natalia N.; Samosudova, Yanina S.; Markin, Alexey V.; Serkova, Elena S.; Kuchkina, Nina V.; Shifrina, Zinaida B.
2017-01-01
Highlights: • We report thermodynamic properties for poly(phenylene-pyridyl) dendrons of the second and the third generations. • The thermodynamic quantities of devitrification and fusion have been determined. • Thermodynamic functions for the temperature range from T → 0 to 520 K for different physical states were calculated. • The dependences of thermodynamic properties of the dendrons on their composition and structure have been obtained. - Abstract: The temperature dependence of the heat capacity of poly(phenylene-pyridyl) dendrons of the second and the third generations have been measured by the method of adiabatic vacuum and differential scanning calorimetry over the range from 6 K to (500–520) K in the present research. Phase transformations have been detected and their thermodynamic characteristics have been estimated and analysed in the above temperature range. The standard thermodynamic functions, namely, the heat capacity C p 0 (T), enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and potential Φ m °, for the range from T → 0 K to (500–520) K and the standard entropy of formation of the dendrons in different physical states at T = 298.15 K have been calculated based on the experimental results. The thermodynamic characteristics of the samples under study and investigated earlier, poly(phenylene-pyridyl) dendrons decorated with dodecyl groups of the same generations have been compared and discussed.
Reaction Kinetic Parameters and Surface Thermodynamic Properties of Cu2O Nanocubes
Directory of Open Access Journals (Sweden)
Xingxing Li
2015-07-01
Full Text Available Cuprous oxide (Cu2O nanocubes were synthesized by reducing Cu(OH2 in the presence of sodium citrate at room temperature. The samples were characterized in detail by field-emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray powder diffraction, and N2 absorption (BET specific surface area. The equations for acquiring reaction kinetic parameters and surface thermodynamic properties of Cu2O nanocubes were deduced by establishment of the relations between thermodynamic functions of Cu2O nanocubes and these of the bulk Cu2O. Combined with thermochemical cycle, transition state theory, basic theory of chemical thermodynamics, and in situ microcalorimetry, reaction kinetic parameters, specific surface enthalpy, specific surface Gibbs free energy, and specific surface entropy of Cu2O nanocubes were successfully determined. We also introduced a universal route for gaining reaction kinetic parameters and surface thermodynamic properties of nanomaterials.
ECONOMIC IMPORTANCE AND CURATIVE PROPERTIES OF CHICORY
Directory of Open Access Journals (Sweden)
O. M. Vjutnova
2017-01-01
Full Text Available The economic importance of chicory root as raw material for the food industry and for other sectors of the economy is presented in the article. Healing properties of the culture and its application in the medical purposes have been also shown.
Thermodynamic properties of vitamin B{sub 2}
Energy Technology Data Exchange (ETDEWEB)
Knyazev, A.V., E-mail: knyazevav@gmail.com; Letyanina, I.A.; Plesovskikh, A.S.; Smirnova, N.N.; Knyazeva, S.S.
2014-01-10
Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B{sub 2} has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B{sub 2} have been determined for the range from T → 0 to 322 K. • The energy of combustion of the riboflavin has been measured at 298.15 K. • The enthalpy of combustion Δ{sub c}H° and the thermodynamic parameters Δ{sub f}H°, Δ{sub f}S°, Δ{sub f}G° have been calculated. - Abstract: In the present work temperature dependence of heat capacity of vitamin B{sub 2} (riboflavin) has been measured for the first time in the range from 6 to 322 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B{sub 2}, namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 322 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the riboflavin has been measured at 298.15 K. The enthalpy of combustion Δ{sub c}H° and the thermodynamic parameters Δ{sub f}H°, Δ{sub f}S°, Δ{sub f}G° and of reaction of formation of the riboflavin from simple substances at T = 298.15 K and p = 0.1 MPa have been calculated.
Arróyave, Raymundo; Liu, Zi-Kui
2006-11-01
A comprehensive analysis of the structural, vibrational, and thermodynamic properties of the intermetallic compounds in the Mg-Ca-Sn system has been performed via first-principles calculations. The enthalpies of formation at 0K for all the known structures in this ternary system are calculated and the results are favorably compared—within ˜5kJ/mol-atom in most cases—to the available experimental data. The vibrational contributions to the thermodynamic properties of fcc Ca, hcp Mg, β-Sn , Mg2Ca , Ca2Sn , CaSn , Ca5Sn3 , CaSn3 , Mg2Sn , and MgCaSn are calculated using the supercell method. In all cases, bond stiffening resulting from compound formation results in upward frequency shifts in the phonon density of states, yielding in turn negative entropies of formation. The effects of volume expansion on the vibrational properties were considered through the quasiharmonic approximation. Thermal electronic contributions were also calculated from the electronic density of states. The electronic degrees of freedom were found to be less important than volume expansion at determining the high temperature thermodynamic properties. The predicted thermodynamic properties of the structures agreed satisfactorily with the experimental data available. The relative importance of these two nonharmonic corrections is reversed when analyzing the formation properties. In all compounds, except for CaSn3 , it was found that the variation of both the formation enthalpies and entropies with temperature is negative. This results in a destabilization of the compounds with respect to their constituent elements as the temperature is increased.
International Nuclear Information System (INIS)
Kritskaya, E.B.; Burylev, B.P.; Mojsov, L.P.; Kritskij, V.E.
2005-01-01
Relaying on the experimentally ascertained linear dependence of the Gibbs excessive mole energies on alkali metal ordinal number in the systems MnBr 2 -MBr (M=Na, K, Rb), thermodynamic properties of the melts in binary systems MBr 2 -M'Br (M'=Li, Cs, Fr) were prepared. Concentration dependences of the Gibbs energies, and thermodynamic activities of compounds in the above systems at 1125 K were calculated [ru
Calculation of the thermodynamic properties of liquid Ag–In–Sb alloys
Directory of Open Access Journals (Sweden)
DRAGANA ZIVKOVIC
2006-03-01
Full Text Available The results of calculations of the thermodynamic properties of liquid Ag–In–Sb alloys are presented in this paper. The Redlich–Kister–Muggianu model was used for the calculations. Based on known thermodynamic data for constitutive binary systems and available experimental data for the investigated ternary system, the ternary interaction parameter for the liquid phase in the temperature range 1000–1200 K was determined. Comparison between experimental and calculated results showed their good mutual agreement.
Blending Education and Polymer Science: Semiautomated Creation of a Thermodynamic Property Database
Energy Technology Data Exchange (ETDEWEB)
Tchoua, Roselyne B.; Qin, Jian; Audus, Debra J.; Chard, Kyle; Foster, Ian T.; de Pablo, Juan
2016-09-13
Structured databases of chemical and physical properties play a central role in the everyday research activities of scientists and engineers. In materials science, researchers and engineers turn to these databases to quickly query, compare, and aggregate various properties, thereby allowing for the development or application of new materials. The vast majority of these databases have been generated manually, through decades of labor-intensive harvesting of information from the literature, yet while there are many examples of commonly used databases, a significant number of important properties remain locked within the tables, figures, and text of publications. The question addressed in our work is whether and to what extent the process of data collection can be automated. Students of the physical sciences and engineering are often confronted with the challenge of finding and applying property data from the literature, and a central aspect of their education is to develop the critical skills needed to identify such data and discern their meaning or validity. To address shortcomings associated with automated information extraction while simultaneously preparing the next generation of scientists for their future endeavors, we developed a novel course-based approach in which students develop skills in polymer chemistry and physics and apply their knowledge by assisting with the semiautomated creation of a thermodynamic property database.
Fluorination effects on the thermodynamic, thermophysical and surface properties of ionic liquids
International Nuclear Information System (INIS)
Vieira, N.S.M.; Luís, A.; Reis, P.M.; Carvalho, P.J.; Lopes-da-Silva, J.A.; Esperança, J.M.S.S.; Araújo, J.M.M.; Rebelo, L.P.N.; Freire, M.G.; Pereiro, A.B.
2016-01-01
Highlights: • Surface tension of fluorinated ionic liquids. • Thermophysical properties of fluorinated ionic liquids. • Thermal properties and thermodynamic functions. - Abstract: This paper reports the thermal, thermodynamic, thermophysical and surface properties of eight ionic liquids with fluorinated alkyl side chain lengths equal or greater than four carbon atoms. Melting and decomposition temperatures were determined together with experimental densities, surface tensions, refractive indices, dynamic viscosities and ionic conductivities in a temperature interval ranging from (293.15 to 353.15) K. The surface properties of these fluorinated ionic liquids were discussed and several thermodynamic functions, as well as critical temperatures, were estimated. Coefficients of isobaric thermal expansion, molecular volumes and free volume effects were calculated from experimental values of density and refractive index and compared with previous data. Finally, Walden plots were used to evaluate the ionicity of the investigated ionic liquids.
International Nuclear Information System (INIS)
Takesue, Shinji
1989-01-01
This is the first part of a series devoted to the study of thermodynamic behavior of large dynamical systems with the use of a family of full-discrete and conservative models named elementary reversible cellular automata (ERCAs). In this paper, basic properties such as conservation laws and phase space structure are investigated in preparation for the later studies. ERCAs are a family of one-dimensional reversible cellular automata having two Boolean variables on each site. Reflection and Boolean conjugation symmetries divide them into 88 equivalence classes. For each rule, additive conserved quantities written in a certain form are regarded as a kind of energy, if they exist. By the aid of the discreteness of the variables, every ERCA satisfies the Liouville theorem or the preservation of phase space volume. Thus, if an energy exists in the above sense, statistical mechanics of the model can formally be constructed. If a locally defined quantity is conserved, however, it prevents the realization of statistical mechanics. The existence of such a quantity is examined for each class and a number of rules which have at least one energy but no local conservation laws are selected as hopeful candidates for the realization of thermodynamic behavior. In addition, the phase space structure of ERCAs is analyzed by enumerating cycles exactly in the phase space for systems of comparatively small sizes. As a result, it is revealed that a finite ERCA is not ergodic, that is, a large number of orbits coexist on an energy surface. It is argued that this fact does not necessarily mean the failure of thermodynamic behavior on the basis of an analogy with the ergodic nature of infinite systems
The thermodynamic properties of hydrated γ-Al2O3 nanoparticles
Spencer, Elinor C.; Huang, Baiyu; Parker, Stewart F.; Kolesnikov, Alexander I.; Ross, Nancy L.; Woodfield, Brian F.
2013-12-01
In this paper we report a combined calorimetric and inelastic neutron scattering (INS) study of hydrated γ-Al2O3 (γ-alumina) nanoparticles. These complementary techniques have enabled a comprehensive evaluation of the thermodynamic properties of this technological and industrially important metal oxide to be achieved. The isobaric heat capacity (Cp) data presented herein provide further critical insights into the much-debated chemical composition of γ-alumina nanoparticles. Furthermore, the isochoric heat capacity (Cv) of the surface water, which is so essential to the stability of all metal-oxides at the nanoscale, has been extracted from the high-resolution INS data and differs significantly from that of ice-Ih due to the dominating influence of strong surface-water interactions. This study also encompassed the analysis of four γ-alumina samples with differing pore diameters [4.5 (1), 13.8 (2), 17.9 (3), and 27.2 nm (4)], and the results obtained allow us to unambiguously conclude that the water content and pore size have no influence on the thermodynamic behaviour of hydrated γ-alumina nanoparticles.
Gordon, S.
1982-01-01
Thermodynamic and transport combustion properties were calculated for a wide range of conditions for the reaction of hydrocarbons with air. Three hydrogen-carbon atom ratios (H/C = 1.7, 2.0, 2.1) were selected to represent the range of aircraft fuels. For each of these H/C ratios, combustion properties were calculated for the following conditions: Equivalence ratio: 0, 0.25, 0.5, 0.75, 1.0, 1.25 Water - dry air mass ratio: 0, 0.03 Pressure, kPa: 1.01325, 10.1325, 101.325, 1013.25, 5066.25 (or in atm: 0.01, 0.1, 1, 10, 50) Temperature, K: every 10 degrees from 200 to 900 K; every 50 degrees from 900 to 3000 K Temperature, R: every 20 degrees from 360 to 1600 R; very 100 degrees from 1600 to 5400 R. The properties presented are composition, density, molecular weight, enthalphy, entropy, specific heat at constant pressure, volume derivatives, isentropic exponent, velocity of sound, viscosity, thermal conductivity, and Prandtl number. Property tables are based on composites that were calculated by assuming both: (1) chemical equilibrium (for both homogeneous and heterogeneous phases) and (2) constant compositions for all temperatures. Properties in SI units are presented in this report for the Kelvin temperature schedules.
Structure-property maps and optimal inversion in configurational thermodynamics
Arnold, Björn; Díaz Ortiz, Alejandro; Hart, Gus L. W.; Dosch, Helmut
2010-03-01
Cluster expansions of first-principles density-functional databases in multicomponent systems are now used as a routine tool for the prediction of zero- and finite-temperature physical properties. The ability of producing large databases of various degrees of accuracy, i.e., high-throughput calculations, makes pertinent the analysis of error propagation during the inversion process. This is a very demanding task as both data and numerical noise have to be treated on equal footing. We have addressed this problem by using an analysis that combines the variational and evolutionary approaches to cluster expansions. Simulated databases were constructed ex professo to sample the configurational space in two different and complementary ways. These databases were in turn treated with different levels of both systematic and random numerical noise. The effects of the cross-validation level, size of the database, type of numerical imprecisions on the forecasting power of the expansions were extensively analyzed. We found that the size of the database is the most important parameter. Upon this analysis, we have determined criteria for selecting the optimal expansions, i.e., transferable expansions with constant forecasting power in the configurational space (a structure-property map). As a by-product, our study provides a detailed comparison between the variational cluster expansion and the genetic-algorithm approaches.
Investigation methods for the determination of thermodynamic properties of lithium alloys
International Nuclear Information System (INIS)
Sommer, F.
1981-01-01
For the determination of thermodynamic properties of the highly reactive lithium alloys, during the last years a number of measuring methods, especially apt for the investigation of these systems, have been developed. The most important measuring arrangements are presented in regard to their manner of function and their technical applicability for the measurements. Among these devices are high temperature calorimeters for the determination of mixing enthalpies of liquid alloys, whilst the formation enthalpies of intermetallic compounds can be determined using a suitable solution calorimeter. Heat contents measurements using a drop calorimeter are resulting in the determination of specific heats, of the enthalpy of fusion and of the temperature dependence of the mixing enthalpy. The Gibbs free enthalpy of mixing of lithium alloys can successfully be determined using suitable galvanic cells. (orig.)
Experimental verification of the thermodynamic properties for a jet-A fuel
Graciasalcedo, Carmen M.; Brabbs, Theodore A.; Mcbride, Bonnie J.
1988-01-01
Thermodynamic properties for a Jet-A fuel were determined by Shell Development Company in 1970 under a contract for NASA Lewis Research Center. The polynomial fit necessary to include Jet-A fuel (liquid and gaseous phases) in the library of thermodynamic properties of the NASA Lewis Chemical Equilibrium Program is calculated. To verify the thermodynamic data, the temperatures of mixtures of liquid Jet-A injected into a hot nitrogen stream were experimentally measured and compared to those calculated by the program. Iso-octane, a fuel for which the thermodynamic properties are well known, was used as a standard to calibrate the apparatus. The measured temperatures for the iso-octane/nitrogen mixtures reproduced the calculated temperatures except for a small loss due to the non-adiabatic behavior of the apparatus. The measurements for Jet-A were corrected for this heat loss and showed excellent agreement with the calculated temperatures. These experiments show that this process can be adequately described by the thermodynamic properties fitted for the Chemical Equilibrium Program.
International Nuclear Information System (INIS)
Dubovitskii, V.A.; Pavlov, G.A.; Krasnikov, Yu.G.
1996-01-01
Thermodynamic analysis of media with strong interparticle (Coulomb) interaction is presented. A method for constructing isotherms is proposed for a medium described by a closed multicomponent thermodynamic model. The method is based on choosing an appropriate nondegenerate frame of reference in the extended space of thermodynamic variables and provides efficient thermodynamic calculations in a wide range of parameters, for an investigation of phase transitions of the first kind, and for determining both the number of phases and coexistence curves. A number of approximate thermodynamic models of hydrogen plasma are discussed. The approximation corresponding to the n5/2 law, in which the effects of particle attraction and repulsion are taken into account qualitatively, is studied. This approximation allows studies of thermodynamic properties of a substance for a wide range of parameters. In this approximation, for hydrogen at a constant temperature, various properties of the degree of ionization are revealed. In addition, the parameters of the second critical point are found under conditions corresponding to the Jovian interior
Low-Temperature Synthesis and Thermodynamic and Electrical Properties of Barium Titanate Nanorods
Directory of Open Access Journals (Sweden)
Florentina Maxim
2015-01-01
Full Text Available Studies regarding the morphology dependence of the perovskite-type oxides functional materials properties are of recent interest. With this aim, nanorods (NRs and nanocubes (NCs of barium titanate (BaTiO3 have been successfully synthesized via a hydrothermal route at temperature as low as 408 K, employing barium acetate, titanium isopropoxide, and sodium hydroxide as reagents without any surfactant or template. Scanning electron microscopy (SEM, transmission electron microscopy (TEM, and X-ray powder diffraction (XRD, used for the morphology and structure analyses, showed that the NRs were formed by an oriented attachment of the NCs building-blocks with 20 nm average crystallites size. The thermodynamic properties represented by the relative partial molar free energies, enthalpies, and entropies of the oxygen dissolution in the perovskite phase, as well as the equilibrium partial pressure of oxygen, indicated that NRs powders have lower oxygen vacancies concentration than the NCs. This NRs characteristic, together with higher tetragonallity of the structure, leads to the enhancement of the dielectric properties of BaTiO3 ceramics. The results presented in this work show indubitably the importance of the nanopowders morphology on the material properties.
Energy Technology Data Exchange (ETDEWEB)
Tong Bo [Thermochemistry Laboratory, Dalian Institute of Chemical physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Tan Zhicheng [Thermochemistry Laboratory, Dalian Institute of Chemical physics, Chinese Academy of Sciences, Dalian 116023 (China) and College of Environmental Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China)]. E-mail: tzc@dicp.ac.cn; Shi Quan [Thermochemistry Laboratory, Dalian Institute of Chemical physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Li Yansheng [College of Environmental Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China); Yue Danting [Thermochemistry Laboratory, Dalian Institute of Chemical physics, Chinese Academy of Sciences, Dalian 116023 (China); Wang Shaoxu [College of Environmental Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China)
2007-06-15
The low-temperature heat capacity C{sub p,m}{sup 0} of xylitol was precisely measured in the temperature range from 80 to 390K by means of a small sample automated adiabatic calorimeter. A solid-liquid phase transition was found from the experimental C{sub p}-T curve in the temperature range 360-375K with the peak heat capacity at 369.04K. The dependence of heat capacity on the temperature was fitted to the following polynomial equations with least square method. In the temperature range of 80-360K, C{sub p,m}{sup 0}(JK{sup -1}mol{sup -1})=165.87+105.19x+1.8011x{sup 2}-41.445x{sup 3}-41.851x{sup 4}+65.152x{sup =} 5+66.744x{sup 6},x=[T(K)-220]/140. In the temperature range of 370-390K, C{sub p,m}{sup 0}(JK{sup -1}mol{sup -1})=426.19+5.6366x,x=[T(K)-380]/10. The molar enthalpy and entropy of this transition were determined to be 33.26+/-0.17kJmol{sup -1} and 90.12+/-0.45JK{sup -1}mol{sup -1}, respectively. The standard thermodynamic functions (H{sub T}{sup 0}-H{sub 298.15}{sup 0}) and (S{sub T}{sup 0}-S{sub 298.15}{sup 0}), were derived from the heat capacity data in the temperature range of 80 to 390K with an interval of 5K. The standard molar enthalpy of combustion and the standard molar enthalpy of formation of the compound have been determined, {delta}{sub c}H{sub m}{sup 0} (C{sub 5}H{sub 12}O{sub 5}, cr)=(-2463.2+/-1.2)kJmol{sup -1}and {delta}{sub f}H{sub m}{sup 0} (C{sub 5}H{sub 12}O{sub 5}, cr)=(-1219.3+/-0.3)kJmol{sup -1}, by means of a precision oxygen bomb combustion calorimeter at T=298.15K. DSC and TG measurements were performed to study the thermal stability of the compound. The results were in agreement with those obtained from heat capacity measurements.
Hrubý, Jan; Duška, Michal
2014-03-01
We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated) and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics equations in the conservative form. Thermodynamic properties of dry steam and liquid water are formulated in terms of special thermodynamic potentials and all properties are obtained as analytical derivatives. For the surface tension, the IAPWS formula is used. The interfacial internal energy is derived from the surface tension and it is used in the energy balance. Unlike common models, the present one provides real (contrary to perfect gas approximation) properties of steam and water and reflects the energetic effects due to the surface tension. The equations are based on re-fitting the reference formulation IAPWS-95 and selected experimental data. The mathematical structure of the equations is optimized for fast computation.
Directory of Open Access Journals (Sweden)
Hrubý Jan
2014-03-01
Full Text Available We present a system of analytical equations for computation of all thermodynamic properties of dry steam and liquid water (undesaturated, saturated and metastable supersaturated and properties of the liquid-vapor phase interface. The form of the equations is such that it enables computation of all thermodynamic properties for independent variables directly related to the balanced quantities - total mass, liquid mass, energy, momenta. This makes it suitable for the solvers of fluid dynamics equations in the conservative form. Thermodynamic properties of dry steam and liquid water are formulated in terms of special thermodynamic potentials and all properties are obtained as analytical derivatives. For the surface tension, the IAPWS formula is used. The interfacial internal energy is derived from the surface tension and it is used in the energy balance. Unlike common models, the present one provides real (contrary to perfect gas approximation properties of steam and water and reflects the energetic effects due to the surface tension. The equations are based on re-fitting the reference formulation IAPWS-95 and selected experimental data. The mathematical structure of the equations is optimized for fast computation.
Thermodynamic and transport properties of air/water mixtures
Fessler, T. E.
1981-01-01
Subroutine WETAIR calculates properties at nearly 1,500 K and 4,500 atmospheres. Necessary inputs are assigned values of combinations of density, pressure, temperature, and entropy. Interpolation of property tables obtains dry air and water (steam) properties, and simple mixing laws calculate properties of air/water mixture. WETAIR is used to test gas turbine engines and components operating in relatively humid air. Program is written in SFTRAN and FORTRAN.
Thermodynamic properties of some metal oxide-zirconia systems
Jacobson, Nathan S.
1989-01-01
Metal oxide-zirconia systems are a potential class of materials for use as structural materials at temperatures above 1900 K. These materials must have no destructive phase changes and low vapor pressures. Both alkaline earth oxide (MgO, CaO, SrO, and BaO)-zirconia and some rare earth oxide (Y2O3, Sc2O3, La2O3, CeO2, Sm2O3, Gd2O3, Yb2O3, Dy2O3, Ho2O3, and Er2O3)-zirconia system are examined. For each system, the phase diagram is discussed and the vapor pressure for each vapor species is calculated via a free energy minimization procedure. The available thermodynamic literature on each system is also surveyed. Some of the systems look promising for high temperature structural materials.
Pyrene-modified unlocked nucleic acids: synthesis, thermodynamic studies, and fluorescent properties
DEFF Research Database (Denmark)
Karlsen, Kasper K; Pasternak, Anna; Jensen, Troels B
2012-01-01
Two pyrene-modified UNA monomers were synthesized and incorporated into 21-mer DNA oligonucleotides. Melting temperatures and thermodynamic properties of the modified duplexes were measured, and the fluorescence properties of single strands and duplexes containing one or more pyrene...... pyrene-UNA modifications, whereas this excimer emission disappeared after hybridization to DNA. In view of both the pyrene monomer and the excimer fluorescence emission, the triply modified oligonucleotides show intriguing properties relating to the development of new DNA/RNA detection tools....
International Nuclear Information System (INIS)
Fraser, D.G.; Refson, K.
1992-01-01
The molecular dynamics calculations reported above give calculated P-V-T properties for H 2 O up to 1500 K and 100 GPa, which agree remarkably well with the available experimental data. We also observe the phase transition to a crystalline, orientationally disordered cubic ice structure. No account was taken of molecular flexibility in these calculations nor of potential dissociation at high pressures as suggested by Hamman (1981). However, we note that the closest next-nearest-neighbour O-H approach remains significantly greater than the TIP4P fixed O-H bond length within the water molecule for all pressures studied. The equation of state proposed here should be useful for estimating the properties of H 2 O at up to 1500 K and 100 G Pa (1 Mbar) and is much easier to use in practice than modified Redlich Kwong equations. Extension of these methods to the studies of other fluids and of fluid mixtures at high temperatures and pressures will require good potential models for the species involved, and this is likely to involve a combination of good ab initio work and semiempirical modelling. Once developed, these models should allow robust predictions of thermodynamic properties beyond the range of the experimental data on the basis of fundamental molecular information
Reduction of tungstates and molybdates by hydrogen and thermodynamic properties of these salts
International Nuclear Information System (INIS)
Gerasimov, Ya.I.; Rezukhina, T.N.; Simanov, Yu.P.; Vasil'eva, I.A.; Kurshakova, R.D.
1988-01-01
Study of thermodynamic properties of a series of tungstates of bivalent metals (Mg, Ca, Sr, Ba, Mn, Co, Fe, Ni, Cu, Zn, Cd and Pb) as well as of some molybdates- of Mg, Ca, Sr, Ba is carried out. The obtained values are compared with magnetic characteristics of compounds and parameters of their crystal lattices. Thermodynamic properties were studied by measuring constants of their reduction with hydrogen in the 500-1350 deg C temperature range. It is concluded that dependence of thermodynamic values on geometric parameters of the lattice is not definitive. Comparison of salt formation atomic entropies with deviations of salt magnetic moments from theoretical ionic moments points to the fact of existence of some accordance between these two series of values. 25 refs.; 10 figs.; 6 tabs
Advanced working fluids: Thermodynamic properties. Final report, 1 December 1987-30 November 1989
Energy Technology Data Exchange (ETDEWEB)
Lee, L.L.; Gering, K.L.
1990-09-01
Electrolytes are used as working fluids in gas-fired heat pump-chiller engine cycles. To find out which molecular parameters of the electrolytes impact on cycle performance, a molecular theory, the EXP-MSA correlation, is developed for calculating solution properties, enthalpies, vapor-liquid equilibria, and engine cycle performance. Aqueous and ammoniac single and mixed salt solutions in single and multisolvent systems are investigated. The outcomes are: (1) an accurate correlation is developed to evaluate properties for concentrated electrolyte solutions (e.g., for aqueous LiBr to 19 molal); (2) sensitivity analysis is used to determine the impact of molecular parameters on the thermodynamic properties and cycle performance. The preferred electrolytes are of 1-1 valence type, small ion size, high molecular weight, and in a strongly colligative cosolvent; (3) the abilities of correlation on single-effect and double-effect engine cycles are demonstrated; (4) the operating windows are determined for a number of absorption fluids of industrial importance.
Theoretical study of elastic, mechanical and thermodynamic properties of MgRh intermetallic compound
Directory of Open Access Journals (Sweden)
S. Boucetta
2014-03-01
Full Text Available In the last years, Magnesium alloys are known to be of great technological importance and high scientific interest. In this work, density functional theory plane-wave pseudo potential method, with local density approximation (LDA and generalized gradient approximation (GGA are used to perform first-principles quantum mechanics calculations in order to investigate the structural, elastic and mechanical properties of the intermetallic compound MgRh with a CsCl-type structure. Comparison of the calculated equilibrium lattice constant and experimental data shows good agreement. The elastic constants were determined from a linear fit of the calculated stress–strain function according to Hooke's law. From the elastic constants, the bulk modulus B, shear modulus G, Young's modulus E, Poisson's ratio σ, anisotropy factor A and the ratio B/G for MgRh compound are obtained. The sound velocities and Debye temperature are also predicted from elastic constants. Finally, the linear response method has been used to calculate the thermodynamic properties. The temperature dependence of the enthalpy H, free energy F, entropy S, and heat capacity at constant volume Cv of MgRh crystal in a quasi-harmonic approximation have been obtained from phonon density of states and discussed for the first report. This is the first quantitative theoretical prediction of these properties.
International Nuclear Information System (INIS)
Babu, B.V.; Chaurasia, A.S.
2004-01-01
In the present study, a simultaneous chemical kinetics and heat transfer model is used to predict the effects of the most important thermal and thermodynamic properties (thermal conductivity, heat transfer coefficient, emissivity and heat of reaction number) of the feedstock on the convective-radiant pyrolysis of biomass fuels. A finite difference pure implicit scheme utilizing the tri-diagonal matrix algorithm is employed for solving the heat transfer model equation. The Runge-Kutta fourth-order method is used for the chemical kinetics model equations. Simulations are performed considering cylindrical pellets of equivalent radius ranging from 0.003 to 0.011 m and temperatures ranging from 303 to 900 K. For conversion in the thermally thick regime (intra-particle heat transfer control), it is found that variations in the properties mainly affect the activity of the primary reactions. Sensitivity analysis is conducted to find the most dominant properties affecting the pyrolysis and found that the highest sensitivity is associated with the emissivity and thermal conductivity of the biomass. Applications of these findings in reactor design and operation are discussed. The results obtained using the improved models are in excellent agreement with the experimental data, much better than the agreement with the earlier models reported in the literature
Redox and thermodynamic properties of Cm and transcurium elements
International Nuclear Information System (INIS)
David, F.
1984-01-01
The investigation of the main properties of heavy actinides shows, in each case (i.e. metal, entropies of aqueous ions, hydration, redox properties) that such basic properties are related to the characteristic parameters as radius, the number of f electrons, charge, electronic transitions. Therefore, expressions are obtained which make possible calculation of unknown data and predictions of properties. More work has to be done to get more reliable calculations fitting closely to experimental data: entropies, structures of many aqueous ions, ionization potentials and even existence or stability of some oxidation states need more imaginative works applying original radiochemical methods and correlations through heavy elements. 9 tables, 13 figs
Pressure–temperature dependence of thermodynamic properties of ...
Indian Academy of Sciences (India)
Haleh Kangarlou and Arash Abdollahi properties of materials under high pressures and temperatures for microscopic under- standing as well as technological applications. In this paper, we report our theoretical study of both pressure and temperature dependences of the thermal properties of rutile within the Debye and ...
Elastic and Thermodynamic Properties of Zirconium and Hafnium ...
Indian Academy of Sciences (India)
65
Key words: Electronic band structure, Elastic properties, Mechanical properties, Ductility, Debye. Temperature. PACS: 61,62,64,71,72,73. 1. Introduction. Refractory materials in the form of intermetallics are used in all major industries, such as electronics, aerospace, automotive, chemicals, mining, nuclear technology, metal.
D-Dimensional ideal gas in parastatistics.: thermodynamic properties
International Nuclear Information System (INIS)
Sousa Vieira, M. C. de; Tsallis, C.
1986-01-01
A parastatistics ideal gas with energy spectrum ε is proportional to |k| → sup (α) (α>0) or even more general in a d-dimensional box with volume V (periodic boundary conditions), the number N of the gas particles being well determined (real particles) or not (quasi particles), is considered. The main thermodynamic quantities (chemical potential, internal energy, specific heat C, equation of state, latent heat, average numbers of particles) for arbitrary d,α, T (temperature) and p (maximal number of particles per state allowed in the parastatistics), are calculated. The main asymptotic regimes are worked out explicitly. In particular, the Bose-Einstein condensation for fixed density, N/V appears as a non uniform convergence in the p→ ∞ limit, in complete analogy with the standard critical phenomena which appear in interacting systems in the N →∞ limit. The system behaves essentially like a Fermi-Dirac one for all finite values of p, and reveals a Bose-Einstein behavior only in the p → ∞ limit. For instance, at low temperatures C ∝ T if p d/α if p → ∞. Finally the Sommerfeld integral and its expansion are generalized to an arbitrary finite p. (author) [pt
Thermodynamic Properties for A Drop-in Refrigerant R-SP34E
Kayukawa, Yohei; Hondo, Takashi; Watanabe, Koichi
Although a transition into several promising HFC alternative refrigerants and their mixtures from conventional CFC and/or HCFC refrigerants is steadily in progress, there still remains a niche to pursue a drop-in refrigerant in some limited engineering applications where the advantage of retrofitting can be emphasized.R-SP34E is one of such drop-in refrigerants to complement R-12 which is a ternary mixture refrigerant consisted of R-134a with minor fractions of propane and ethanol. In this paper, the fundamental thermodynamic properties such as VLE properties and gas-phase PVT properties of R-SP34E are presented. This paper reports the first sets of measured data including 7 dew-and bubble-point pressures and 73 gas-phase PVT properties in the extensive range of temperatures 300-380 K, pressures 0.1-5.2 MPa, and densities up to around the critical density, obtained by employing the Burnett apparatus. In order to complement and confirm the reliability of the measurements, thermodynamic models including a dew-point pressure correlation and a truncated virial equation of state were originally developed in this study. The models were confirmed to exhibit not only excellent reproducibility of the measurements but also the thermodynamic consistency regarding the temperature dependence of the second and third virial coefficients and derived properties such as specific heats or speed of sound. By presenting the reliable thermodynamic model, a systematic information about the thermodynamic properties of R-SP34E is provided in this paper.
Microscopic and thermodynamic properties of dense semiclassical partially ionized hydrogen plasma
Energy Technology Data Exchange (ETDEWEB)
Ramazanov, T S; Dzhumagulova, K N; Gabdullin, M T [IETP, Al-Farabi Kazakh National University, 96a, Tole Bi St, Almaty, 050012 (Kazakhstan)
2006-04-28
Microscopic and thermodynamic properties of dense semiclassical partially ionized hydrogen plasma were investigated on the basis of pseudopotential models. Radial distribution functions (RDF) of particles were obtained using a system of the Ornstein-Zernike integral equations. The corrections to internal energy and the equation of state were calculated using RDF.
REMC Computer Simulation of the Thermodynamic Properties of Argon and Air Plasmas
Czech Academy of Sciences Publication Activity Database
Lísal, Martin; Smith, W. R.; Bureš, M.; Vacek, V.; Navrátil, J.
2002-01-01
Roč. 100, č. 15 (2002), s. 2487-2497 ISSN 0026-8976 R&D Projects: GA ČR GA203/98/1446; GA ČR GA203/02/0805 Grant - others:NSERC(CA) OGP1041 Keywords : computer simulation * plasma * thermodynamic properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.617, year: 2002
Mean-field potential approach for thermodynamic properties of lanthanide: Europium as a prototype
Kumar, Priyank; Bhatt, N. K.; Vyas, P. R.; Gohel, V. B.
2018-03-01
In the present paper, a simple conjunction scheme [mean-field potential (MFP) + local pseudopotential] is used to study the thermodynamic properties of divalent lanthanide europium (Eu) at extreme environment. Present study has been carried out due to the fact that divalent nature of Eu arises because of stable half-filled 4f-shell at ambient condition, which has great influence on the thermodynamic properties at extreme environment. Due to such electronic structure, it is different from remaining lanthanides having incomplete 4f-shell. The presently computed results of thermodynamic properties of Eu are in good agreement with the experimental results. Looking to such success, it seems that the concept of MFP approach is successful to account contribution due to nuclear motion to the total Helmholtz free energy at finite temperatures and pressure-induced inter-band transfer of electrons for condensed state of matter. The local pseudopotential is used to evaluate cold energy and hence MFP accounts the s-p-d-f hybridization properly. Looking to the reliability and transferability along with its computational and conceptual simplicity, we would like to extend the present scheme for the study of thermodynamic properties of remaining lanthanides and actinides at extreme environment.
Modelling of physical and thermodynamic properties in systems containing edible oils and biodiesel
DEFF Research Database (Denmark)
Cunico, Larissa; Ceriani, Roberta; Sarup, Bent
The knowledge of physical and thermodynamic properties of pure components and their mixtures is a basic requirement for performing tasks related to process design, simulation, and optimization and also for performing chemical product design using computer aided molecular/mixture design (CAMD) too...
Thermodynamic and surface properties of Sb–Sn and In–Sn liquid ...
Indian Academy of Sciences (India)
ϵbb] ,. (16) where the prime on P denotes the first derivative with respect to x. .... asymmetric about equiatomic concentration while that of In–Sn is very symmetric. This deviation from ideal behaviour of the thermodynamic properties of Sb–Sn is.
DEFF Research Database (Denmark)
Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan
Computer Aided Molecular Design (CAMD) is an important tool to generate, test and evaluate promising chemical products. CAMD can be used in thermodynamic cycle for the design of pure component or mixture working fluids in order to improve the heat transfer capacity of the system. The safety...... assessment of novel working fluids relies on accurate property data. Flammability data like the lower and upper flammability limit (LFL and UFL) play an important role in quantifying the risk of fire and explosion. For novel working fluid candidates experimental values are not available for the safety...
A theoretical prediction of thermodynamic properties of chlorine fluorides
International Nuclear Information System (INIS)
Du, Hongchen; Liu, Yan; Wang, Fang; Zhang, Jianying; Liu, Hui; Gong, Xuedong
2011-01-01
Graphical abstract: Correlation between the HOFs obtained from the formation reactions (HOF(FR)) and modified formation reactions (HOF(MFR)). Highlights: → We calculate the heats of formation of nine chlorine fluorides - ClF, ClF 3 , ClF 5 , ClFO, ClFO 2 , ClFO 3 , ClF 3 O 2 , ClF 3 O, and ClF 5 O. → The formation reaction in conjunction with the G3 theory can give accurate results. → ClF, ClF 3 , ClF 5 and ClF 3 O are stable at the room temperature. → ClFO 2 , ClF 3 O 2 and ClF 5 O may be stable at lower temperature. - Abstract: The heats of formation of ClF, ClF 3 , ClF 5 , ClFO, ClFO 2 , ClFO 3 , ClF 3 O 2 , ClF 3 O, and ClF 5 O have been calculated with the help of atomization reaction (AR), formation reaction (FR), and modified formation reaction (MFR) at the G3 and G3X (X = B3, MP2, and MP2B3) levels. FR or MFR in conjunction with the G3 theory can give accurate results close to experimental values. The standard thermodynamic functions of the title compounds have also been evaluated and the results agree well with the available experimental data. Results show that ClF, ClF 3 , ClF 5 and ClF 3 O are stable at the room temperature, and ClFO 2 , ClF 3 O 2 , and ClF 5 O may be stable at lower temperature.
Determination of the thermodynamic properties of water from the speed of sound
International Nuclear Information System (INIS)
Trusler, J.P. Martin; Lemmon, Eric W.
2017-01-01
Highlights: • We analyse error propagation in thermodynamic integration of fluid-phase sound speed data. • A new correlation of the speed of sound in liquid water is derived. • Thermodynamic integration is carried out for pure water. • Derived properties considered include density, isobaric expansivity and isobaric specific heat capacity. - Abstract: Thermodynamic properties of compressed liquids may be obtained from measurements of the speed of sound by means of thermodynamic integration subject to initial values of density and isobaric specific heat capacity along a single low-pressure isobar. In this paper, we present an analysis of the errors in the derived properties arising from perturbations in both the speed-of-sound surface and the initial values. These errors are described in first order by a pair of partial differential equations that we integrate for the example case of water with various scenarios for the errors in the sound speed and the initial values. The analysis shows that errors in either the speed of sound or the initial values of density that are rapidly oscillating functions of temperature have a disproportionately large influence on the derived properties, especially at low temperatures. In view of this, we have obtained a more accurate empirical representation of the recent experimental speed-of-sound data for water [Lin and Trusler, J. Chem. Phys. 136, (2012) 094511] and use this in a new thermodynamic integration to obtain derived properties including density, isobaric heat capacity and isobaric thermal expansivity at temperatures between (253.15 and 473.15) K at pressures up to 400 MPa. The densities obtained in this way are in very close agreement with those reported by Lin and Trusler, but the isobaric specific heat capacity and the isobaric expansivity both differ significantly in the extremes of low temperatures and high pressures.
Wang, Gui-xiang; Gong, Xue-dong; Liu, Yan; Xiao, He-ming
2009-10-01
The nitro derivatives of phenols are optimized to obtain their molecular geometries and electronic structures at the DFT-B3LYP/6-31 G* level. Their IR spectra are obtained and assigned by vibrational analysis and are reliable compared with the experimental results. Based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics, the thermodynamic properties are evaluated, which are linearly related with the number of nitro and hydroxy groups as well as the temperature, obviously showing good group additivity.
Belov, G. V.; Dyachkov, S. A.; Levashov, P. R.; Lomonosov, I. V.; Minakov, D. V.; Morozov, I. V.; Sineva, M. A.; Smirnov, V. N.
2018-01-01
The database structure, main features and user interface of an IVTANTHERMO-Online system are reviewed. This system continues the series of the IVTANTHERMO packages developed in JIHT RAS. It includes the database for thermodynamic properties of individual substances and related software for analysis of experimental results, data fitting, calculation and estimation of thermodynamical functions and thermochemistry quantities. In contrast to the previous IVTANTHERMO versions it has a new extensible database design, the client-server architecture, a user-friendly web interface with a number of new features for online and offline data processing.
Directory of Open Access Journals (Sweden)
Hammou Amine Bouziane
2013-03-01
Full Text Available We study the thermodynamic and structural properties of a flexible homopolymer chain using both multi canonical Monte Carlo method and Wang-Landau method. In this work, we focus on the coil-globule transition. Starting from a completely random chain, we have obtained a globule for different sizes of the chain. The implementation of these advanced Monte Carlo methods allowed us to obtain a flat histogram in energy space and calculate various thermodynamic quantities such as the density of states, the free energy and the specific heat. Structural quantities such as the radius of gyration where also calculated.
Hot magnetized nuclear matter: Thermodynamic and saturation properties
Energy Technology Data Exchange (ETDEWEB)
Rezaei, Z. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Bordbar, G.H. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Center for Excellence in Astronomy and Astrophysics (CEAA-RIAAM)-Maragha, Maragha (Iran, Islamic Republic of)
2017-03-15
We have used a realistic nuclear potential, AV{sub 18}, and a many-body technique, the lowest-order constraint variational (LOCV) approach, to calculate the properties of hot magnetized nuclear matter. By investigating the free energy, spin polarization parameter, and symmetry energy, we have studied the temperature and magnetic field dependence of the saturation properties of magnetized nuclear matter. In addition, we have calculated the equation of state of magnetized nuclear matter at different temperatures and magnetic fields. It was found that the flashing temperature of nuclear matter decreases by increasing the magnetic field. In addition, we have studied the effect of the magnetic field on liquid gas phase transition of nuclear matter. The liquid gas coexistence curves, the order parameter of the liquid gas phase transition, and the properties of critical point at different magnetic fields have been calculated. (orig.)
Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels
Hu, Shenyang; Setyawan, Wahyu; Joshi, Vineet V.; Lavender, Curt A.
2017-07-01
Xe gas bubble superlattice formation is observed in irradiated uranium-10 wt% molybdenum (U10Mo) fuels. However, the thermodynamic properties of the bubbles (the relationship among bubble size, equilibrium Xe concentration, and bubble pressure) and the mechanisms of bubble superlattice formation are not well known. In this work, the molecular dynamics (MD) method is used to study these properties and mechanisms. The results provide important inputs for quantitative mesoscale models of gas bubble evolution and fuel performance. In the MD simulations, the embedded-atom method (EAM) potential of U10Mo-Xe [1] is employed. Initial gas bubbles with a low Xe concentration (underpressured) are generated in a body-centered cubic (bcc) U10Mo single crystal. Then Xe atoms are sequentially added into the bubbles one by one, and the evolution of pressure and dislocation emission around the bubbles is analyzed. The relationship between pressure, equilibrium Xe concentration, and radius of the bubbles is established. It was found that an overpressured gas bubble emits partial dislocations with a Burgers vector along the direction and a slip plane of (11-2). Meanwhile, dislocation loop punch out was not observed. The overpressured bubble also induces an anisotropic stress field. A tensile stress was found along directions around the bubble, favoring the nucleation and formation of a face-centered cubic bubble superlattice in bcc U10Mo fuels.
First principles calculation of thermodynamic properties of NaAlSi ternary
International Nuclear Information System (INIS)
Qin Jining; Lu Weijie; Zhang Di; Fan Tongxiang
2012-01-01
PbFCl-type NaAlSi ternary is a corrosion compound found in aluminum, which is used as a sealing material in sodium sulfur battery. To understand and control the corrosion process, it is important to predict its quantitative properties. In this study, a first-principles calculation has been carried out to calculate its equilibrium lattice parameters, bulk modulus and pressure derivative of bulk modulus by both all-electron full-potential linear augmented plane wave scheme and pseudopotential plane wave scheme within the generalized gradient approximation. The theoretical results show good agreement with the available experimental data. The thermodynamic properties, including the specific heat capacity and entropy with pressure up to 9 GPa, have been investigated for the first time by coupling of density functional perturbation theory and quasiharmonic approximation. The volume and linear thermal expansion coefficients were estimated and the results show that the linear thermal expansion on c-axis is nearly twice as large as that on a-axis within the calculated temperature.
Theoretical study of structural, elastic and thermodynamic properties of CZTX (X = S and Se) alloys
Energy Technology Data Exchange (ETDEWEB)
Bensalem, S., E-mail: bensalemse@gmail.com [Centre de Développement des Energies Renouvelables, CDER, BP 62 Route de l’Observatoire Bouzaréah, 16340 Algiers (Algeria); Département de Physique, Faculté des Sciences, Université de Sétif 1, 19000 Sétif (Algeria); Chegaar, M. [Département de Physique, Faculté des Sciences, Université de Sétif 1, 19000 Sétif (Algeria); Laboratoire d’Optoélectronique et Composants, Université de Sétif 1, 19000 Sétif (Algeria); Maouche, D.; Bouhemadou, A. [Laboratoire de Développement de Nouveaux Matériaux et leurs Caractérisations, Université de Sétif 1, 19000 Sétif (Algeria)
2014-03-15
Highlights: • CZTX (X = S, Se) alloys are relatively new absorbers for solar cells applications. • Elastic and thermodynamic properties of these alloys are not well understood. • The considered types “kesterite and stannite” can coexist in experimental samples. • Elastic and thermodynamic properties of both types have been investigated. • Coexistence of both types does not influence the behavior of CZTX-based devices. -- Abstract: By means of first-principles calculation approach, structural parameters, elastic and thermodynamic properties of Copper–Zinc–Tin–(Sulphide, Selenide) or Cu{sub 2}ZnSnX{sub 4} (X = S and Se) alloys for the kesterite (KS) and stannite (ST) types have been investigated. The calculated lattice parameters are in good agreement with experimental reported data. The elastic constants are calculated for both types of both compounds using the static finite strain scheme; the pressure dependence of elastic constants is predicted. The bulk modulus, anisotropy factor, shear modulus, Young’s modulus, Lame’s coefficient and Poisson’s ratio have been estimated from the calculated single crystalline elastic constants. The analysis of B/G ratio shows that Cu{sub 2}ZnSnX{sub 4} or CZTX compounds behave as ductile. Through quasi-harmonic approximation, the temperature dependence of some thermodynamic functions and lattice heat capacity of both compounds for both types have been performed.
International Nuclear Information System (INIS)
Noh, Seunghyo; Kwak, Dohyun; Lee, Juseung; Kang, Joonhee; Han, Byungchan
2014-01-01
We utilized first-principles density-functional-theory (DFT) calculations to evaluate the thermodynamic feasibility of a pyroprocessing methodology for reducing the volume of high-level radioactive materials and recycling spent nuclear fuels. The thermodynamic properties of transuranium elements (Pu, Np and Cm) were obtained in electrochemical equilibrium with a LiCl-KCl molten salt as ionic phases and as adsorbates on a W(110) surface. To accomplish the goal, we rigorously calculated the double layer interface structures on an atomic resolution, on the thermodynamically most stable configurations on W(110) surfaces and the chemical activities of the transuranium elements for various coverages of those elements. Our results indicated that the electrodeposition process was very sensitive to the atomic level structures of Cl ions at the double-layer interface. Our studies are easily expandable to general electrochemical applications involving strong redox reactions of transition metals in non-aqueous solutions.
Elastic and thermodynamic properties of zirconium- and hafnium ...
Indian Academy of Sciences (India)
2018-02-02
Feb 2, 2018 ... ity, bonding mechanism, ductile/brittle behaviour and thermal properties of these alloys are analysed and reported. In addition, Debye temperature, Grüneisen parameter and melting temperature values are calculated for these alloy combinations. In the present work, the full potential linearized augmented.
International Nuclear Information System (INIS)
Gailhanou, H.; Gaboreau, S.; Gaucher, E.C.; Blanc, P.; Rogez, J.; Olives, J.; Amouric, M.; Van Miltenburg, J.C.; Michau, N.; Giffaut, E.
2010-01-01
Document available in extended abstract form only. In the context of nuclear waste repositories in argillaceous formations, it is necessary to assess the geochemical behaviour of natural and engineered clay barriers, namely by the stability of clay minerals over long periods of time. However, thermodynamic data of clay minerals, which are required for geochemical modelling, are still poorly known. The present study aims to improve our comprehension of clay mineral stability. The thermodynamic properties of smectite MX-80 and illite IMt-2 (Silver Hill, Montana) have already been determined using calorimetric methods between 0 K and 520 K, under both dried and hydrated states in the case of smectite. In parallel, solubility experiments were carried out in order to determine the solubility products of the clay minerals. Such experiments require some particular precautions as published by May et al. (1986) and Aja and Rosenberg (1992). According to these authors, it is namely important to reach the equilibrium from both under and over saturation and to characterize from a mineralogical point of view the end products. Taking advantage of previous calorimetric measurements, we propose to compare the solubility products obtained here from dissolution experiments with respect to calorimetry results, in order to assess the equilibrium achievement for the solubility experiments. The study is integrated in the Thermochimie project, which aims to provide a consistent thermodynamic database (Thermochimie) for modelling purposes. This work dealing with a smectite and an illite is being completed by the study of a set of typical clays, selected to be well-representative of the clay group. Enthalpies of formation of the minerals were determined by isothermal dissolution calorimetry at 25 deg. C, using a HF-HNO 3 solution. They were obtained by measuring the enthalpies of dissolution of (i) the sample (clay mineral + impurities) and (ii) the oxide or hydroxide constituent mixture
Thermodynamic and mechanical properties of TiC from ab initio calculation
International Nuclear Information System (INIS)
Dang, D. Y.; Fan, J. L.; Gong, H. R.
2014-01-01
The temperature-dependent thermodynamic and mechanical properties of TiC are systematically investigated by means of a combination of density-functional theory, quasi-harmonic approximation, and thermal electronic excitation. It is found that the quasi-harmonic Debye model should be pertinent to reflect thermodynamic properties of TiC, and the elastic properties of TiC decease almost linearly with the increase of temperature. Calculations also reveal that TiC possesses a pronounced directional pseudogap across the Fermi level, mainly due to the strong hybridization of Ti 3d and C 2p states. Moreover, the strong covalent bonding of TiC would be enhanced (reduced) with the decrease (increase) of temperature, while the change of volume (temperature) should have negligible effect on density of states at the Fermi level. The calculated results agree well with experimental observations in the literature.
Kong, Ge-Xing; Ma, Xiao-Juan; Liu, Qi-Jun; Li, Yong; Liu, Zheng-Tang
2018-03-01
Using first-principles calculations method based on density functional theory (DFT) with the Perdew-Burke-Ernzerhof (PBE) implementation of the generalized gradient approximation (GGA), we investigate the structural, elastic and thermodynamic properties of gold-copper intermetallic compounds (Au-Cu ICs). The calculated lattice parameters are in excellent agreement with experimental data. The elastic constants show that all the investigated Au-Cu alloys are mechanically stable. Elastic properties, including the shear modulus, Young's modulus, Poisson's ratio and Pugh's indicator, of the intermetallic compounds are evaluated and discussed, with special attention to the remarkable anisotropy displayed by Au-Cu ICs. Thermodynamic and transport properties including the Debye temperature, thermal conductivity and melting point are predicted from the averaged sound velocity and elastic moduli, using semi-empirical formulas.
Haskins, Justin B.; Lawson, John W.
2017-05-01
We present a procedure to determine temperature-dependent thermodynamic properties of crystalline materials from density functional theory molecular dynamics (DFT-MD). Finite temperature properties (structural, thermal, and mechanical properties) of the phases (ground state monoclinic B33, martensitic B19', and austenitic B2) of the shape memory alloy NiTi are investigated. Fluctuation formulas and numerical derivatives are used to evaluate mechanical and thermal properties. A modified version of thermodynamic upsampling is used to predict properties in the high DFT convergence threshold limit from low threshold simulations. DFT convergence thresholds. In addition, a thermodynamic integration expression is developed to compute free energies from isobaric DFT-MD simulations that accounts for volume changes. Structural parameters, elastic constants, volume expansion, and specific heats as a function of temperature are evaluated. Phase transitions between B2 and B19' and between B19' and B33 are characterized according to their thermal energy, entropy, and free energy differences as well as their latent heats. Anharmonic effects are shown to play a large role in both stabilizing the austenite B2 phase and suppressing the martensitic phase transition. The quasiharmonic approximation to the free energy results in large errors in estimating the martensitic transition temperature by neglecting these large anharmonic components.
Thermodynamic properties and atomic structure of Ca-based liquid alloys
Poizeau, Sophie
To identify the most promising positive electrodes for Ca-based liquid metal batteries, the thermodynamic properties of diverse Ca-based liquid alloys were investigated. The thermodynamic properties of Ca-Sb alloys were determined by emf measurements. It was found that Sb as positive electrode would provide the highest voltage for Ca-based liquid metal batteries (1 V). The price of such a battery would be competitive for the grid-scale energy storage market. The impact of Pb, a natural impurity of Sb, was predicted successfully and confirmed via electrochemical measurements. It was shown that the impact on the open circuit voltage would be minor. Indeed, the interaction between Ca and Sb was demonstrated to be much stronger than between Ca and Pb using thermodynamic modeling, which explains why the partial thermodynamic properties of Ca would not vary much with the addition of Pb to Sb. However, the usage of the positive electrode would be reduced, which would limit the interest of a Pb-Sb positive electrode. Throughout this work, the molecular interaction volume model (MIVM) was used for the first time for alloys with thermodynamic properties showing strong negative deviation from ideality. This model showed that systems such as Ca-Sb have strong short-range order: Ca is most stable when its first nearest neighbors are Sb. This is consistent with what the more traditional thermodynamic model, the regular association model, would predict. The advantages of the MIVM are the absence of assumption regarding the composition of an associate, and the reduced number of fitting parameters (2 instead of 5). Based on the parameters derived from the thermodynamic modeling using the MIVM, a new potential of mixing for liquid alloys was defined to compare the strength of interaction in different Ca-based alloys. Comparing this trend with the strength of interaction in the solid state of these systems (assessed by the energy of formation of the intermetallics), the systems with
ELECTRICAL AND THERMODYNAMIC PROPERTIES OF A COLLAGEN SOLUTION
Directory of Open Access Journals (Sweden)
Jaromír Štancl
2017-06-01
Full Text Available This paper focuses on measurements of the electrical properties, the specific heat capacity and the thermal conductivity of a collagen solution (7.19% mass fraction of native bovine collagen in water. The results of our experiments show that specific electrical conductivity of collagen solution is strongly dependent on temperature. The transition region of collagen to gelatin has been observed from the measured temperature dependence of specific electrical conductivity, and has been confirmed by specific heat capacity measurements by a differential scanning calorimetry.
International Nuclear Information System (INIS)
Richard T. Scalettar; Warren E. Pickett
2005-01-01
This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals
Energy Technology Data Exchange (ETDEWEB)
Scalettar, Richard T.; Pickett, Warren E.
2004-07-01
This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals.
Energy Technology Data Exchange (ETDEWEB)
Richard T. Scalettar; Warren E. Pickett
2005-08-02
This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (i) Mott transitions in transition metal oxides, (ii) magnetism in half-metallic compounds, and (iii) large volume-collapse transitions in f-band metals.
Samuel A. Cushman
2015-01-01
Entropy and the second law of thermodynamics are the central organizing principles of nature. Or perhaps more accurately, the second law is the central disorganizing principle. Hot things cool down. Cold things warm up. You cannot get something for nothing. You always pay more than you get. Things fall apart. You cannot repeat the past. We grow old and die. It is all...
Important physical properties of peat materials
D.H. Boelter
1968-01-01
Peat materials from 12 bogs in northern Minnesota, U.S.A., showed significant differences in physical properties. It is pointed out that 1) these properties can be related to the hydrology of organic soils only if the soils represent undisturbed field conditions, and 2) volumetric expressions of water content are necessary to correctly evaluate the amount of water in a...
Thermodynamic study of alkane-α,ω-diamines - evidence of odd-even pattern of sublimation properties
Czech Academy of Sciences Publication Activity Database
Fulem, Michal; Růžička, K.; Červinka, C.; Bazyleva, A.; Della Gatta, G.
2014-01-01
Roč. 371, Jun (2014), s. 93-105 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : alkane-diamines * odd–even effect * vapor pressure * sublimation and vaporization thermodynamic properties * statistical thermodynamics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.200, year: 2014
Applied chemical engineering thermodynamics
Tassios, Dimitrios P
1993-01-01
Applied Chemical Engineering Thermodynamics provides the undergraduate and graduate student of chemical engineering with the basic knowledge, the methodology and the references he needs to apply it in industrial practice. Thus, in addition to the classical topics of the laws of thermodynamics,pure component and mixture thermodynamic properties as well as phase and chemical equilibria the reader will find: - history of thermodynamics - energy conservation - internmolecular forces and molecular thermodynamics - cubic equations of state - statistical mechanics. A great number of calculated problems with solutions and an appendix with numerous tables of numbers of practical importance are extremely helpful for applied calculations. The computer programs on the included disk help the student to become familiar with the typical methods used in industry for volumetric and vapor-liquid equilibria calculations.
Thermodynamic properties of liquid copper-indium-tin alloys determined from e.m.f. measurements
International Nuclear Information System (INIS)
Jendrzejczyk-Handzlik, Dominika; Gierlotka, Wojciech; Fitzner, Krzysztof
2009-01-01
The thermodynamics properties of liquid Cu-In-Sn alloys were determined using solid oxide galvanic cells with zirconia electrolyte: (I)Re+kanthal,Cu x -In y -Sn (1-x-y) ,'In 2 O 3 '//ZrO 2 +(Y 2 O 3 )//NiO,Ni,Pt in the temperature range (973 to 1223) K. Applied In 2 O 3 can be either pure or in the solid solutions with SnO 2 . Thermodynamics properties of the liquid phase were described by the Redlich-Kister-Muggianu formula. Using the commercial software different phase relations in the ternary system were calculated and compared with experimental data found in the literature
Study of thermodynamic properties of Np-Al alloys in molten LiCl-KCl eutectic
Energy Technology Data Exchange (ETDEWEB)
Mendes, E.; Soucek, P.; Malmbeck, R.; Glatz, J. P. [Institute for Transuranium Elements, Karlsruhe (Germany); Caravaca, C. [CIEMAT, DE/DFN/URAA, Madrid (Spain)
2008-08-15
This work is focused on chemical characterisation and determination of thermodynamic properties of Np-Al alloys. The alloys are formed on a solid Al electrode during Np electrodeposition in molten LiCl-KCl Eutectic. Open circuit potential measurements, after small depositions of Np metal onto the Al electrode were used to determine thermodynamic properties of the Np-Al alloys formed (G, H, S, activity of Np in Al) by an e.m.f. method. Galvanostatic electrolyses were carried out on an Al plates. Stable Np-Al deposit was obtained and identified, by XRD analysis, as a mixture NpAl{sub 3} and NpAl{sub 4} alloys.
Thermodynamic properties of betulinic acid in THF + water mixed solvents at different temperatures
Energy Technology Data Exchange (ETDEWEB)
Shi, Wei [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Cheng, Yong [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Skyherb Ingredients, Anji 313300 (China); Shao, Yundong [Skyherb Ingredients, Anji 313300 (China); Yan, Weidong, E-mail: yanweidong@zju.edu.cn [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China)
2014-12-20
Highlights: • The solubilities of betulinic acid in the THF + water were determined at different temperatures. • The highest solubility value is obtained in the pure THF. • The thermodynamic properties of the solution process and the crystal habit of betulinic acid were discussed. - Abstract: The solubilities of betulinic acid in binary solvent mixtures of THF + water in the temperature range of (278.2–318.2) K were determined by an analytical method. The solubility of betulinic acid in a binary solvent mixture increased with the increase of molar fraction of THF and the temperature. The solubilities data were correlated with a semi-empirical equation. The calculated solubilities showed good agreement with the experimental data. According to the Van’t Hoff equation and the Gibbs equation, the thermodynamic properties for the solution process including Gibbs energy, enthalpy, and entropy were obtained. The crystal habit of betulinic acid changes in morphology at different solvent mixtures was observed using SEM.
Directory of Open Access Journals (Sweden)
Bidai K.
2017-06-01
Full Text Available First-principles density functional theory calculations have been performed to investigate the structural, elastic and thermodynamic properties of rubidium telluride in cubic anti-fluorite (anti-CaF2-type structure. The calculated ground-state properties of Rb2Te compound such as equilibrium lattice parameter and bulk moduli are investigated by generalized gradient approximation (GGA-PBE that are based on the optimization of total energy. The elastic constants, Young’s and shear modulus, Poisson ratio, have also been calculated. Our results are in reasonable agreement with the available theoretical and experimental data. The pressure dependence of elastic constant and thermodynamic quantities under high pressure are also calculated and discussed.
Energy Technology Data Exchange (ETDEWEB)
Xu, Wen-Sheng, E-mail: wsxu@uchicago.edu [James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Freed, Karl F., E-mail: freed@uchicago.edu [James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Department of Chemistry, The University of Chicago, Chicago, Illinois 60637 (United States)
2015-07-14
The lattice cluster theory (LCT) for semiflexible linear telechelic melts, developed in Paper I, is applied to examine the influence of chain stiffness on the average degree of self-assembly and the basic thermodynamic properties of linear telechelic polymer melts. Our calculations imply that chain stiffness promotes self-assembly of linear telechelic polymer melts that assemble on cooling when either polymer volume fraction ϕ or temperature T is high, but opposes self-assembly when both ϕ and T are sufficiently low. This allows us to identify a boundary line in the ϕ-T plane that separates two regions of qualitatively different influence of chain stiffness on self-assembly. The enthalpy and entropy of self-assembly are usually treated as adjustable parameters in classical Flory-Huggins type theories for the equilibrium self-assembly of polymers, but they are demonstrated here to strongly depend on chain stiffness. Moreover, illustrative calculations for the dependence of the entropy density of linear telechelic polymer melts on chain stiffness demonstrate the importance of including semiflexibility within the LCT when exploring the nature of glass formation in models of linear telechelic polymer melts.
Thermodynamics of Aβ16-21 dissociation from a fibril: Enthalpy, entropy, and volumetric properties.
Rao Jampani, Srinivasa; Mahmoudinobar, Farbod; Su, Zhaoqian; Dias, Cristiano L
2015-11-01
Here, we provide insights into the thermodynamic properties of A β16-21 dissociation from an amyloid fibril using all-atom molecular dynamics simulations in explicit water. An umbrella sampling protocol is used to compute potentials of mean force (PMF) as a function of the distance ξ between centers-of-mass of the A β16-21 peptide and the preformed fibril at nine temperatures. Changes in the enthalpy and the entropic energy are determined from the temperature dependence of these PMF(s) and the average volume of the simulation box is computed as a function of ξ. We find that the PMF at 310 K is dominated by enthalpy while the entropic energy does not change significantly during dissociation. The volume of the system decreases during dissociation. Moreover, the magnitude of this volume change also decreases with increasing temperature. By defining dock and lock states using the solvent accessible surface area (SASA), we find that the behavior of the electrostatic energy is different in these two states. It increases (unfavorable) and decreases (favorable) during dissociation in lock and dock states, respectively, while the energy due to Lennard-Jones interactions increases continuously in these states. Our simulations also highlight the importance of hydrophobic interactions in accounting for the stability of A β16-21. © 2015 Wiley Periodicals, Inc.
Thermodynamics and elastic properties of Ir from first-principle calculations
International Nuclear Information System (INIS)
Li Qiang; Huang Duohui; Cao Qilong; Wang Fanhou
2013-01-01
Within the framework of the quasiharmonic approximation, the thermodynamics and elastic properties, including phonon dispersion curves, equation of state, linear thermal expansion coefficient and temperature-dependent entropy, enthalpy, heat capacity, elastic constants, bulk modulus, shear modulus, Young's modulus of Ir have been studied using first-principles projector-augmented wave method. The results revealed that the predicted phonon dispersion curves of Ir are in agreement with the experimental measurements by neutron diffractions. Considering the thermal electronic contribution to Helmholtz free energy, the calculated entropy, enthalpy, heat capacity and linear thermal expansion co- efficient from the first-principle are consistent well with the experimental data. At 2600 K, the electronic heat capacity accounts for 17% of the total heat capacity at constant pressure, thus the thermal electronic contribution to Helmholtz free energy is very important. The predicted elastic constants, bulk modulus, shear modulus and Young's modulus at room temperature are also in agreement with the available measurements and increase with the increasing temperature. (authors)
Influence of shell effects on thermodynamic properties of matter at high pressures
Levashov, P. R.; Minakov, D. V.
2018-01-01
We analyze the influence of shell effects on thermodynamic properties of matter at high pressures. Spherically symmetric average atom models show significant contribution of electronic transitions to cold pressure which is not confirmed by more accurate density functional theory models. In particular, the s–d transition in aluminum and potassium does not reveal itself on the shock Hugoniots. Oscillations on shock Hugoniots at very high pressures predicted earlier by many authors should be confirmed by precise first-principle calculations.
International Nuclear Information System (INIS)
Smith, W.H.; Costa, D.A.
1998-01-01
This is the final report of a six-month, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of this work was to establish a capability for the measurement of fundamental thermodynamic properties of actinide elements in room temperature molten salts. This capability will be used to study in detail the actinide chloro- and oxo- coordination chemistries that dominate in the chloride-based molten salt media. Uranium will be the first actinide element under investigation
Thermodynamic properties of sticky electrolytes in the HNC/MS approximation
International Nuclear Information System (INIS)
Herrera, J.N.; Blum, L.
1991-01-01
We study an approximation for a model which combines the sticky potential of Baxter and charged spheres. In the hypernetted chain (HNC)/mean spherical approximation (MSA), simple expressions for the thermodynamic functions are obtained. There equations should be useful in representing the properties of real electrolytes. Approximate expressions that are similar to those of the primitive model are obtained, for low densities (concentrations) of the electrolyte (Author)
Energy Technology Data Exchange (ETDEWEB)
Mahendra P, Verma [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)
2005-07-01
In this paper are presented, the thermodynamic inconsistencies in formulation IAPWS-95 as well as the limitations in the experimental data of the thermodynamic properties of the water. In addition, a new methodology was developed: Verma procedure for the measurement of the calorific capacity of water. Thus, a procedure is presented to calculate other thermodynamic properties of liquids such as water. In the transformation processes of the planet Earth, water is an essential component. Nevertheless, the knowledge about its properties is still very limited. Recently, Verma developed a new program: SteamTablesIIE, to calculate the properties of water as a function of two independent variables between temperatures (T), pressure (P), volume (V), internal energy (U), enthalpy (H), Gibas energy (G) and entropy (S). Yet, thermodynamic inconsistencies were found in the formulation, same that are the limiting factors for the operation of the SteamTablesIIE in all the ranks of the independent variables. [Spanish] En este trabajo se presentan, tanto las inconsistencias termodinamicas en la formulacion IAPWS-95 como las limitaciones en los datos experimentales de las propiedades termodinamicas del agua. Ademas, se desarrollo una nueva metodologia: Procedimiento Verma para la medicion de la capacidad calorifica del agua. Asi, se presenta un procedimiento para calcular otras propiedades termodinamicas de liquidos tales como el agua. En los procesos de transformacion del planeta tierra, el agua es un componente esencial. Sin embargo, el conocimiento acerca de sus propiedades es todavia muy limitado. Recientemente, Verma desarrollo un nuevo programa: SteamTablesIIE, para calcular las propiedades del agua como una funcion de dos variables independientes entre temperaturas (T), presion (P), volumen (V), energia interna (U), entalpia (H), energia Gibas (G) y entropia (S). Con todo, se encontraron inconsistencias termodinamicas en la formulacion, mismas que son las limitantes para el
Advanced thermodynamics engineering
Annamalai, Kalyan; Jog, Milind A
2011-01-01
Thermolab Excel-Based Software for Thermodynamic Properties and Flame Temperatures of Fuels IntroductionImportance, Significance and LimitationsReview of ThermodynamicsMathematical BackgroundOverview of Microscopic/NanothermodynamicsSummaryAppendix: Stokes and Gauss Theorems First Law of ThermodynamicsZeroth LawFirst Law for a Closed SystemQuasi Equilibrium (QE) and Nonquasi-equilibrium (NQE) ProcessesEnthalpy and First LawAdiabatic Reversible Process for Ideal Gas with Constant Specific HeatsFirst Law for an Open SystemApplications of First Law for an Open SystemIntegral and Differential Form
Insights into Mercury's Core Evolution from the Thermodynamic Properties of Fe-S-Si
Edgington, A.; Vocadlo, L.; Stixrude, L. P.; Wood, I. G.; Lord, O. T.
2015-12-01
The structure, composition and evolution of Mercury, the innermost planet, are puzzling, as its high uncompressed density implies a body highly enriched in metallic iron, whilst the existence of Mercury's magnetic field and observations of its longitude librations [1] suggest at least a partially molten core. This study uses a combination of experimental and ab-initio computer simulation techniques to determine the properties of Fe-S-Si (relative atomic percentages, 80:10:10) throughout the conditions of the interior of the planet Mercury, and evaluates the implications of this material for the structure and evolution of the planet's core. Previous studies have considered the addition of sulphur to the pure iron system, as this can significantly depress the melting curve of iron, and so may possibly allow Mercury's core to remain molten to the present day [2]. However, important constraints placed by the MESSENGER spacecraft on Mercury's surface abundance of iron [3] suggest that the planet formed in highly reduced conditions, in which significant amounts of silicon could have also dissolved into the core [4]. First-principles molecular dynamics simulations of the thermodynamic properties of liquid Fe-S-Si, alongside laser-heated diamond-anvil-cell experiments to determine the melting behaviour of the same composition, reveal the slopes of the adiabatic gradient and melting curve respectively, which together may allow insight into the evolution of our solar system's smallest planet. [1] Margot, J. L. et al. (2007) Science, 316: 710-714[2] Schubert, G. et al. (1988) in 'Mercury' 429-460[3] Nittler, L. R. et al. (2011) Science, 333, 1847-1850[4] Malavergne, V. et al. (2010) Icarus, 206:199-209
Free energy of formation of Mo2C and the thermodynamic properties of carbon in solid molybdenum
Seigle, L. L.; Chang, C. L.; Sharma, T. P.
1979-01-01
As part of a study of the thermodynamical properties of interstitial elements in refractory metals, the free energy of formation of Mo2C is determined, and the thermodynamical properties of C in solution in solid Mo evaluated. The activity of C in the two-phase region Mo + Mo2C is obtained from the C content of iron rods equilibrated with metal + carbide powder mixtures. The free energy of formation of alpha-Mo2C is determined from the activity data. The thermodynamic properties of C in the terminal solid solution are calculated from available data on the solid solubility of C in Mo. Lattice distortion due to misfit of the C atoms in the interstitial sites appears to play a significant role in determining the thermodynamic properties of C in solid Mo.
Gordon, S.
1982-01-01
The equilibrium compositions corresponding to the thermodynamic and transport combustion properties for a wide range of conditions for the reaction of hydrocarbons with air are presented. The compositions presented correspond to Rankine temperature schedules.
Chandel, Namrata; Mehta, Neeraj
2018-04-01
In this study, we prepared novel selenium rich multi-component glasses by incorporating In, Cd and Sb as foreign elements in an Sn containing Sesbnd Te system in order to study their metal-induced effects on the thermal properties of the parent ternary glass. In particular, we determined the thermodynamic parameters of Se80Te18Sn2 and Se80Te8Sn2M10 (M = Cd, In, Sb) glassy semiconductors in a non-isothermal environment using the differential scanning calorimetry. Calorimetric measurements were obtained in the glass transition regions for Se80Te18Sn2 and Se80Te8Sn2M10 (M = Cd, In, Sb) glasses to determine their thermodynamic parameters such as the specific heat, enthalpy, and entropy during glass transition. We analyzed the variation in the specific heat before and after the heat capacity jump in these alloys. The metal-induced effects of foreign elements on the thermodynamic properties of the parent glass were also investigated in terms of the influence of the elemental specific heat of the added elemental metal as well as the thermal stability and glass-forming ability of the glasses.
Numerical Prediction of the Thermodynamic Properties of Ternary Al-Ni-Pd Alloys
Zagula-Yavorska, Maryana; Romanowska, Jolanta; Kotowski, Sławomir; Sieniawski, Jan
2016-01-01
Thermodynamic properties of ternary Al-Ni-Pd system, such as exGAlNPd, µAl(AlNiPd), µNi(AlNiPd) and µPd(AlNiPd) at 1,373 K, were predicted on the basis of thermodynamic properties of binary systems included in the investigated ternary system. The idea of predicting exGAlNiPd values was regarded as calculation of values of the exG function inside a certain area (a Gibbs triangle) unless all boundary conditions, that is values of exG on all legs of the triangle are known (exGAlNi, exGAlPd, exGNiPd). This approach is contrary to finding a function value outside a certain area, if the function value inside this area is known. exG and LAl,Ni,Pd ternary interaction parameters in the Muggianu extension of the Redlich-Kister formalism were calculated numerically using the Excel program and Solver. The accepted values of the third component xx differed from 0.01 to 0.1 mole fraction. Values of LAlNiPd parameters in the Redlich-Kister formula are different for different xx values, but values of thermodynamic functions: exGAlNiPd, µAl(AlNiPd), µNi(AlNiPd) and µPd(AlNiPd) do not differ significantly for different xx values. The choice of xx value does not influence the accuracy of calculations.
Crystal structure, thermodynamics, magnetics and disorder properties of Be–Fe–Al intermetallics
International Nuclear Information System (INIS)
Burr, P.A.; Middleburgh, S.C.; Grimes, R.W.
2015-01-01
Highlights: • DFT atomistic modelling + phonon DOS + Bragg–Williams order/disorder. • A novel Fe–Be binary structure was identified ε-Fe 2 Be 17 . • Small additions of Al stabilises δ-FeBe 5 over ζ-FeBe 2 and ε-Fe 2 Be 17 . • δ-FeBe 5 and ε-Fe 2 Be 17 may accommodate deviations from stoichiometry. - Abstract: The elastic and magnetic properties, thermodynamical stability, deviation from stoichiometry and order/disorder transformations of phases that are relevant to Be alloys were investigated using density functional theory simulations coupled with phonon density of states calculations to capture temperature effects. A novel structure and composition were identified for the Be–Fe binary ε phase. In absence of Al, FeBe 5 is predicted to form at equilibrium above ∼1100 K, while the ε phase is stable only below ∼1500 K, and FeBe 2 is stable at all temperatures below melting. Small additions of Al are found to stabilise FeBe 5 over FeBe 2 and ε, while at high Al content, AlFeBe 4 is predicted to form. Deviations from stoichiometric compositions are also considered and found to be important in the case of FeBe 5 and ε. The propensity for disordered vs ordered structures is also important for AlFeBe 4 (which exhibits complete Al–Fe disordered at all temperatures) and FeBe 5 (which exhibits an order–disorder transition at ∼950 K)
Thermodynamic properties and transport coefficients of two-temperature helium thermal plasmas
Guo, Xiaoxue; Murphy, Anthony B.; Li, Xingwen
2017-03-01
Helium thermal plasmas are in widespread use in arc welding and many other industrial applications. Simulation of these processes relies on accurate plasma property data, such as plasma composition, thermodynamic properties and transport coefficients. Departures from LTE (local thermodynamic equilibrium) generally occur in some regions of helium plasmas. In this paper, properties are calculated allowing for different values of the electron temperature, T e, and heavy-species temperature, T h, at atmospheric pressure from 300 K to 30 000 K. The plasma composition is first calculated using the mass action law, and the two-temperature thermodynamic properties are then derived. The viscosity, diffusion coefficients, electrical conductivity and thermal conductivity of the two-temperature helium thermal plasma are obtained using a recently-developed method that retains coupling between electrons and heavy species by including the electron-heavy-species collision term in the heavy-species Boltzmann equation. It is shown that the viscosity and the diffusion coefficients strongly depend on non-equilibrium ratio θ (θ ={{T}\\text{e}}/{{T}\\text{h}} ), through the plasma composition and the collision integrals. The electrical conductivity, which depends on the electron number density and ordinary diffusion coefficients, and the thermal conductivity have similar dependencies. The choice of definition of the Debye length is shown to affect the electrical conductivity significantly for θ > 1. By comparing with literature data, it is shown that the coupling between electrons and heavy species has a significant influence on the electrical conductivity, but not on the viscosity. Plasma properties are tabulated in the supplementary data.
DEFF Research Database (Denmark)
Tušek, Jaka; Engelbrecht, Kurt; Mañosa, Lluis
2016-01-01
This paper presents direct and indirect methods for studying the elastocaloric effect (eCE) in shape memory materials and its comparison. The eCE can be characterized by the adiabatic temperature change or the isothermal entropy change (both as a function of applied stress/strain). To get...... these quantities, the evaluation of the eCE can be done using either direct methods, where one measures (adiabatic) temperature changes or indirect methods where one can measure the stress–strain–temperature characteristics of the materials and from these deduce the adiabatic temperature and isothermal entropy...... changes. The former can be done using the basic thermodynamic relations, i.e. Maxwell relation and Clausius–Clapeyron equation. This paper further presents basic thermodynamic properties of shape memory materials, such as the adiabatic temperature change, isothermal entropy change and total entropy...
Thermodynamics of Accelerating Black Holes.
Appels, Michael; Gregory, Ruth; Kubizňák, David
2016-09-23
We address a long-standing problem of describing the thermodynamics of an accelerating black hole. We derive a standard first law of black hole thermodynamics, with the usual identification of entropy proportional to the area of the event horizon-even though the event horizon contains a conical singularity. This result not only extends the applicability of black hole thermodynamics to realms previously not anticipated, it also opens a possibility for studying novel properties of an important class of exact radiative solutions of Einstein equations describing accelerated objects. We discuss the thermodynamic volume, stability, and phase structure of these black holes.
Mccarty, R. D.
1980-01-01
The thermodynamic and transport properties of selected cryogens had programmed into a series of computer routines. Input variables are any two of P, rho or T in the single phase regions and either P or T for the saturated liquid or vapor state. The output is pressure, density, temperature, entropy, enthalpy for all of the fluids and in most cases specific heat capacity and speed of sound. Viscosity and thermal conductivity are also given for most of the fluids. The programs are designed for access by remote terminal; however, they have been written in a modular form to allow the user to select either specific fluids or specific properties for particular needs. The program includes properties for hydrogen, helium, neon, nitrogen, oxygen, argon, and methane. The programs include properties for gaseous and liquid states usually from the triple point to some upper limit of pressure and temperature which varies from fluid to fluid.
Directory of Open Access Journals (Sweden)
Dallakyan Sargis
2008-08-01
Full Text Available Abstract Background Gram-negative bacteria use periplasmic-binding proteins (bPBP to transport nutrients through the periplasm. Despite immense diversity within the recognized substrates, all members of the family share a common fold that includes two domains that are separated by a conserved hinge. The hinge allows the protein to cycle between open (apo and closed (ligated conformations. Conformational changes within the proteins depend on a complex interplay of mechanical and thermodynamic response, which is manifested as an increase in thermal stability and decrease of flexibility upon ligand binding. Results We use a distance constraint model (DCM to quantify the give and take between thermodynamic stability and mechanical flexibility across the bPBP family. Quantitative stability/flexibility relationships (QSFR are readily evaluated because the DCM links mechanical and thermodynamic properties. We have previously demonstrated that QSFR is moderately conserved across a mesophilic/thermophilic RNase H pair, whereas the observed variance indicated that different enthalpy-entropy mechanisms allow similar mechanical response at their respective melting temperatures. Our predictions of heat capacity and free energy show marked diversity across the bPBP family. While backbone flexibility metrics are mostly conserved, cooperativity correlation (long-range couplings also demonstrate considerable amount of variation. Upon ligand removal, heat capacity, melting point, and mechanical rigidity are, as expected, lowered. Nevertheless, significant differences are found in molecular cooperativity correlations that can be explained by the detailed nature of the hydrogen bond network. Conclusion Non-trivial mechanical and thermodynamic variation across the family is explained by differences within the underlying H-bond networks. The mechanism is simple; variation within the H-bond networks result in altered mechanical linkage properties that directly affect
Structural and Thermodynamic Properties of Amyloid-β Peptides: Impact of Fragment Size
Kitahara, T.; Wise-Scira, O.; Coskuner, O.
2010-10-01
Alzheimer's disease is a progressive neurodegenerative disease whose physiological characteristics include the accumulation of amyloid-containing deposits in the brain and consequent synapse and neuron loss. Unfortunately, most widely used drugs for the treatment can palliate the outer symptoms but cannot cure the disease itself. Hence, developing a new drug that can cure it. Most recently, the ``early aggregation and monomer'' hypothesis has become popular and a few drugs have been developed based on this hypothesis. Detailed understanding of the amyloid-β peptide structure can better help us to determine more effective treatment strategies; indeed, the structure of Amyloid has been studied extensively employing experimental and theoretical tools. Nevertheless, those studies have employed different fragment sizes of Amyloid and characterized its conformational nature in different media. Thus, the structural properties might be different from each other and provide a reason for the existing debates in the literature. Here, we performed all-atom MD simulations and present the structural and thermodynamic properties of Aβ1-16, Aβ1-28, and Aβ1-42 in the gas phase and in aqueous solution. Our studies show that the overall structures, secondary structures, and the calculated thermodynamic properties change with increasing peptide size. In addition, we find that the structural properties of those peptides are different from each other in the gas phase and in aqueous solution.
Thermodynamic properties of steam and water adapted for the IBM 360/195 computer
International Nuclear Information System (INIS)
Burgess, M.P.; Fuller, G.L.; Kaiser, A.H.
1976-09-01
In 1921, the American Society of Mechanical Engineers began an effort to provide reliable and consistent tables of the thermodynamic properties of steam and water. In 1936, J.H. Keenan and F.G. Keyes published a set of steam tables that served as an accepted reference. These tables were revised in 1969 using the least squares technique on a computer to interpolate the data points. Because the tables are based on physical data points, they remain the standard for checking the fit of any formulation of thermodynamic properties. A set of formulations describing the properties of steam was adopted in 1966 as an international standard by the ASME International Formulation Committee of the Sixth Conference on the Properties of Steam. These formulations are reproduced in Appendices 1 and 2 of the 1967 ASME Steam Tables. Computer programs based on these formulations were published by McClintock and Sylvestri in 1967 and improved in 1970. The program STEAM67 was developed by the American Society of Mechanical Engineers; it is a collection of individual routines each designed for a specific problem. A second program, ASTEM, was developed by the Aerojet Nuclear Company; it is more general and provides information used to calculate specific solutions. The programs were tested on the IBM 360/195 computer and results compared with published values
Keshavarzi, Ezat; Kamalvand, Mohammad
2009-04-23
The structure and properties of fluids confined in nanopores may show a dramatic departure from macroscopic bulk fluids. The main reason for this difference lies in the influence of system walls. In addition to the entropic wall effect, system walls can significantly change the energy of the confined fluid compared to macroscopic bulk fluids. The energy effect of the walls on a nanoconfined fluid appears in two forms. The first effect is the cutting off of the intermolecular interactions by the walls, which appears for example in the integrals for calculation of the thermodynamic properties. The second wall effect involves the wall-molecule interactions. In such confined fluids, the introduction of wall forces and the competition between fluid-wall and fluid-fluid forces could lead to interesting thermodynamic properties, including new kinds of phase transitions not observed in the macroscopic fluid systems. In this article, we use the perturbative fundamental measure density functional theory to study energy effects on the structure and properties of a hard core two-Yukawa fluid confined in a nanoslit. Our results show the changes undergone by the structure and phase transition of the nanoconfined fluids as a result of energy effects.
Thermodynamics of nuclear materials
International Nuclear Information System (INIS)
1979-01-01
conditions. There was also a session on accident analysis, a very important topic in today's nuclear technology. Other topics related to fission reactor technology included thermodynamics in waste management and fuel reprocessing. One severe limitation to scientists working in applied thermodynamics has been the lack of basic or fundamental thermodynamic data. Accordingly, several sessions of the Symposium were devoted to basic data on nuclear fuels as well as fundamental data on the thermodynamic properties of nuclear materials. The Symposium was indeed a timely one. It served as a mechanism by which the participants gained a comprehensive and complete picture of the current status of international thermodynamic investigations on nuclear materials. The data presented at the Symposium is not the final answer to nuclear material problems, but it will serve as a guide for further investigations. (author)
Starikov, S. V.; Kolotova, L. N.; Kuksin, A. Yu.; Smirnova, D. E.; Tseplyaev, V. I.
2018-02-01
We studied structure and thermodynamic properties of cubic and tetragonal phases of pure uranium and U-Mo alloys using atomistic simulations: molecular dynamics and density functional theory. The main attention was paid to the metastable γ0 -phase that is formed in U-Mo alloys at low temperature. Structure of γ0 -phase is similar to body-centered tetragonal (bct) lattice with displacement of a central atom in the basic cell along [ 001 ] direction. Such displacements have opposite orientations for part of the neighbouring basic cells. In this case, such ordering of the displacements can be designated as antiferro-displacement. Formation of such complex structure may be interpreted through forming of short U-U bonds. At heating, the tetragonal structure transforms into cubic γs -phase, still showing ordering of central atom displacements. With rise in temperature, γs -phase transforms to γ-phase with a quasi body-centered cubic (q-bcc) lattice. The local positions of uranium atoms in γ-phase correspond to γs -phase, however, orientations of the central atom displacements become disordered. Transition from γ0 to γ can be considered as antiferro-to paraelastic transition of order-disorder type. This approach to the structure description of uranium alloy allows to explain a number of unusual features found in the experiments: anisotropy of lattice at low temperature; remarkably high self-diffusion mobility in γ-phase; decreasing of electrical resistivity at heating for some alloys. In addition, important part of this work is the development of new interatomic potential for U-Mo system made with taking into account details of studied structures.
The use of molecular dynamics for the thermodynamic properties of simple and transition metals
International Nuclear Information System (INIS)
Straub, G.K.
1987-04-01
The technique of computer simulation of the molecular dynamics in metallic systems to calculate thermodynamic properties is discussed. The nature of a metal as determined by its electronic structure is used to determine the total adiabatic potential. The effective screened ion-ion interaction can then be used in a molecular dynamics simulation. The method for the construction of a molecular dynamics ensemble, its relation to the canonical ensemble, and the definition of thermodynamic functions from the Helmholtz free energy is given. The method for the analysis of the molecular dynamics results from quasiharmonic lattice dynamics and the decomposition in terms of harmonic and anharmonic contributions is given for solids. For fluid phase metals, procedures for calculating the thermodynamics and determining the constant of entropy are presented. The solid-fluid phase boundary as a function of pressure and temperature is determined using the results of molecular dynamics. Throughout, examples and results for metallic sodium are used. The treatment of the transition metal electronic d-states in terms of an effective pair-wise interaction is also discussed and the phonon dispersion curves of Al, Ni, and Cu are calculated
Calculation of the thermodynamic properties of the GaSbTl liquid alloys
Directory of Open Access Journals (Sweden)
DRAGAN MANASIJEVIC
2005-02-01
Full Text Available The results of the calculation of the thermodynamic properties for liquid GaSbTl alloys at the temperature 1073 K are presented in this paper. Initially, the most appropriate thermodynamic model for the investigated system was selected. Based on a comparison of the values calculated by different geometric models (Kohler, Muggianu, Toop, Hillert, Chou with the existing experimental based data, asymmetric models of calculation were determined to give the best results. The asymmetric nature of the investigated ternary system was additionally confirmed by the Chou similarity coefficient concept. For these reasons, further complete thermodynamic calculations were performed according to the Hillert model in five sections of the ternary GaSbTl system from each corner with the mole ratio of other two components being 9:1; 7:3; 5:5; 3:7 and 1:9. The obtained results include integral excess Gibbs energy dependences on composition for all the investigated sections. The calculated activity values at 1073 K for all components are given in the form of isoactivity diagrams. Comparison between the calculated and experimentally obtained gallium activities shows good agreement.
Ahmed, Ahfaz
2018-01-30
Rapid compression machines (RCM) are extensively used to study autoignition of a wide variety of fuels at engine relevant conditions. Fuels ranging from pure species to full boiling range gasoline and diesel can be studied in an RCM to develop a better understanding of autoignition kinetics in low to intermediate temperature ranges. In an RCM, autoignition is achieved by compressing a fuel/oxidizer mixture to higher pressure and temperature, thereby initiating chemical reactions promoting ignition. During these experiments, the pressure is continuously monitored and is used to deduce significant events such as the end of compression and the onset of ignition. The pressure profile is also used to assess the temperature evolution of the gas mixture with time using the adiabatic core hypothesis and the heat capacity ratio of the gas mixture. In such RCM studies, real transportation fuels containing many components are often represented by simpler surrogate fuels. While simpler surrogates such as primary reference fuels (PRFs) and ternary primary reference fuel (TPRFs) can match research and motor octane number of transportation fuels, they may not accurately replicate thermodynamic properties (including heat capacity ratio). This non-conformity could exhibit significant discrepancies in the end of compression temperature, thereby affecting ignition delay (τign) measurements. Another aspect of RCMs that can affect τign measurement is post compression heat loss, which depends on various RCM parameters including geometry, extent of insulation, pre-heating temperature etc. To, better understand the effects of these non-chemical kinetic parameters on τign, thermodynamic properties of a number of FACE G gasoline surrogates were calculated and simulated in a multi-zone RCM model. The problem was further investigated using a variance based analysis and individual sensitivities were calculated. This study highlights the effects on τign due to thermodynamic properties of
Dehghani, M.
2018-02-01
Making use of the suitable transformation relations, the action of three-dimensional Einstein-Maxwell-dilaton gravity theory has been obtained from that of scalar-tensor modified gravity theory coupled to the Maxwell's electrodynamics as the matter field. Two new classes of the static three-dimensional charged dilatonic black holes, as the exact solutions to the coupled scalar, electromagnetic and gravitational field equations, have been obtained in the Einstein frame. Also, it has been found that the scalar potential can be written in the form of a generalized Liouville-type potential. The conserved black hole charge and masses as well as the black entropy, temperature, and electric potential have been calculated from the geometrical and thermodynamical approaches, separately. Through comparison of the results arisen from these two alternative approaches, the validity of the thermodynamical first law has been proved for both of the new black hole solutions in the Einstein frame. Making use of the canonical ensemble method, a black hole stability or phase transition analysis has been performed. Regarding the black hole heat capacity, with the black hole charge as a constant, the points of type-1 and type-2 phase transitions have been determined. Also, the ranges of the black hole horizon radius at which the Einstein black holes are thermally stable have been obtained for both of the new black hole solutions. Then making use of the inverse transformation relations, two new classes of the string black hole solutions have been obtained from their Einstein counterpart. The thermodynamics and thermal stability of the new string black hole solutions have been investigated. It has been found that thermodynamic properties of the new charged black holes are identical in the Einstein and Jordan frames.
Thermodynamic properties of a solid exhibiting the energy spectrum given by the logistic map
International Nuclear Information System (INIS)
Curado, E.M.F.
2000-05-01
We show that the infinite-dimensional representation of the recently introduced Logistic algebra can be interpreted as a non-trivial generalization of the Heisenberg or oscillator algebra. This allows to construct a quantum Hamiltonian having the energy energy spectrum given by the logistic map. We analyze the Hamiltonian of a solid whose collective modes of vibrations are described by this generalized oscillator and compute the thermodynamic properties of the model in the two-cycle and γ3.6785 chaotic region of the logistic map. (author)
Long, Yao; Chen, Jun
2018-01-01
We develop a method to calculate the local vibrational mode and phonon refraction probability of a 1,3,5-triamino-2,4,6-trinitrobenzene/graphite interface, and use them to evaluate the interfacial free energy, heat capacity and thermal conductivity. We find that the heat exchange across the interface is sensitive with five incident phonon states. The frequencies, vibrational modes, refraction angles and refraction probabilities of the sensitive states are calculated. The relationship between vibrational modes and thermodynamic properties at the interface is obtained.
Thermodynamic properties of a quantum group boson gas GLp,q(2)
International Nuclear Information System (INIS)
Jellal, Ahmed
2000-10-01
An approach is proposed enabling to effectively describe the behaviour of a bosonic system. The approach uses the quantum group GL p,q (2) formalism. In effect, considering a bosonic Hamiltonian in terms of the GL p,q (2) generators, it is shown that its thermodynamic properties are connected to deformation parameters p and q. For instance, the average number of particles and the pressure have been computed. If p is fixed to be the same value for q, our approach coincides perfectly with some results developed recently in this subject. The ordinary results, of the present system, can be found when we take the limit p = q = 1. (author)
Djamali, Essmaiil; Cobble, James W
2009-02-26
A new theoretical treatment has been developed for predicting the thermodynamic properties of electrolytes up to and beyond the critical temperature of water (973 K and at pressures up to 1000 MPa). The model is based upon the classical Born equation corrected for non-Born hydration effects. The temperature and pressure behavior of electrolytes can now be accurately predicted from existing low temperature data. Only two constants are needed for each electrolyte at all temperatures and pressures, where data exist to test the theory.
Moustafa, Sabry Gad Al-Hak Mohammad
Molecular simulation (MS) methods (e.g. Monte Carlo (MC) and molecular dynamics (MD)) provide a reliable tool (especially at extreme conditions) to measure solid properties. However, measuring them accurately and efficiently (smallest uncertainty for a given time) using MS can be a big challenge especially with ab initio-type models. In addition, comparing with experimental results through extrapolating properties from finite size to the thermodynamic limit can be a critical obstacle. We first estimate the free energy (FE) of crystalline system of simple discontinuous potential, hard-spheres (HS), at its melting condition. Several approaches are explored to determine the most efficient route. The comparison study shows a considerable improvement in efficiency over the standard MS methods that are known for solid phases. In addition, we were able to accurately extrapolate to the thermodynamic limit using relatively small system sizes. Although the method is applied to HS model, it is readily extended to more complex hard-body potentials, such as hard tetrahedra. The harmonic approximation of the potential energy surface is usually an accurate model (especially at low temperature and large density) to describe many realistic solid phases. In addition, since the analysis is done numerically the method is relatively cheap. Here, we apply lattice dynamics (LD) techniques to get the FE of clathrate hydrates structures. Rigid-bonds model is assumed to describe water molecules; this, however, requires additional orientation degree-of-freedom in order to specify each molecule. However, we were able to efficiently avoid using those degrees of freedom through a mathematical transformation that only uses the atomic coordinates of water molecules. In addition, the proton-disorder nature of hydrate water networks adds extra complexity to the problem, especially when extrapolating to the thermodynamic limit is needed. The finite-size effects of the proton disorder contribution is
Batool, Javaria; Alay-e-Abbas, Syed Muhammad; Amin, Nasir
2018-04-01
The density functional theory based total energy calculations are performed to examine the effect of charge neutral and fully charged intrinsic vacancy defects on the thermodynamic, electronic, and magnetic properties of Ca3SnO antiperovskite. The chemical stability of Ca3SnO is evaluated with respect to binary compounds CaO, CaSn, and Ca2Sn, and the limits of atomic chemical potentials of Ca, Sn, and O atoms for stable synthesis of Ca3SnO are determined within the generalized gradient approximation parametrization scheme. The electronic properties of the pristine and the non-stoichiometric forms of this compound have been explored and the influence of isolated intrinsic vacancy defects (Ca, Sn, and O) on the structural, bonding, and electronic properties of non-stoichiometric Ca3SnO are analyzed. We also predict the possibility of achieving stable ferromagnetism in non-stoichiometric Ca3SnO by means of charge neutral tin vacancies. From the calculated total energies and the valid ranges of atomic chemical potentials, the formation energetics of intrinsic vacancy defects in Ca3SnO are evaluated for various growth conditions. Our results indicate that the fully charged calcium vacancies are thermodynamically stable under the permissible Sn-rich condition of stable synthesis of Ca3SnO, while tin and oxygen vacancies are found to be stable under the extreme Ca-rich condition.
The temperature behaviour of the elastic and thermodynamic properties of fcc thorium
Energy Technology Data Exchange (ETDEWEB)
Jaroszewicz, S., E-mail: jaroszew@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, San Martin (Argentina); Instituto de Tecnologia Jorge A. Sabato, UNSAM-CNEA (Argentina); Mosca, H.O. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, San Martin (Argentina); Instituto de Tecnologia Jorge A. Sabato, UNSAM-CNEA (Argentina); Garces, J.E. [DAEE, Centro Atomico Bariloche, Comisin Nacional de Energia Atomica, Av. Bustillo 9500, Bariloche, Rio Negro (Argentina)
2012-10-15
The temperature behaviour of the structural, elastical and thermal properties of fcc thorium have been calculated from a free-parameter Helmholtz free energy developed by computing the cohesive energy from first principles calculations coupled to the Chen-Moebius lattice inversion method and the Debye-Grueneisen quasiharmonic model. The elastic constants, shear modulus, Young modulus, Poisson's ratio and thermodynamic properties of fcc Th as the entropy, the harmonic specific heat, the (P, V, T) equation of state and the thermal lattice expansion are found to be in a very good agreement with experiments and ab initio phonon calculations. The results of this work show the potentiality of the Chen-Moebius method coupled to ab initio calculation of the cohesive energy to develop a free-parameter pair potential capable of giving an overall description of fcc Th properties at T = 0 K with an error similar to ab initio calculations.
International Nuclear Information System (INIS)
Khaleque, M.A.; Bhuiyan, G.M.; Rashid, R.I.M.A.
1998-01-01
Thermodynamic properties such as entropy, specific heat capacity at constant pressure and isothermal compressibility have been calculated for liquid 3d, 4d and 5d transition metals near melting temperature. The hard sphere diameter for all such systems is estimated from the potential profile generated from the Wills and Harrison's prescription using linearized WCA theory of liquid. Evaluated values of entropy and specific heat capacity are found to be in good agreement with the experimental data. Transport property like shear viscosity for these liquid metals is obtained using the same potential profile. Lack of experimental data at melting temperatures hampers detailed comparison for all such systems. However, for the case of transport property, the results obtained are found to compare qualitatively well with the available experimental data. (author)
Computer programs for thermodynamic and transport properties of hydrogen (tabcode-II)
Roder, H. M.; Mccarty, R. D.; Hall, W. J.
1972-01-01
The thermodynamic and transport properties of para and equilibrium hydrogen have been programmed into a series of computer routines. Input variables are the pair's pressure-temperature and pressure-enthalpy. The programs cover the range from 1 to 5000 psia with temperatures from the triple point to 6000 R or enthalpies from minus 130 BTU/lb to 25,000 BTU/lb. Output variables are enthalpy or temperature, density, entropy, thermal conductivity, viscosity, at constant volume, the heat capacity ratio, and a heat transfer parameter. Property values on the liquid and vapor boundaries are conveniently obtained through two small routines. The programs achieve high speed by using linear interpolation in a grid of precomputed points which define the surface of the property returned.
Improved relationships for the thermodynamic properties of carbon phases at detonation conditions
International Nuclear Information System (INIS)
Stiel, L I; Baker, E L; Murphy, D J
2014-01-01
Accurate volumetric and heat capacity relationships have been developed for graphite and diamond carbon forms for use with the Jaguar thermochemical equilibrium program for the calculation of the detonation properties of explosives. Available experimental thermodynamic properties and Hugoniot values have been analyzed to establish the equations of state for the carbon phases. The diamond-graphite transition curve results from the equality of the chemical potentials of the phases. The resulting relationships are utilized to examine the actual phase behaviour of carbon under shock conditions. The existence of metastable carbon states is established by analyses of Hugoniot data for hydrocarbons and explosives at elevated temperatures and pressures. The accuracy of the resulting relationships is demonstrated by comparisons for several properties, including the Hugoniot behaviour of oxygen-deficient explosives at overdriven conditions.
Mass spectrometric study of thermodynamic properties in the Gd2O3-Y2O3system at high temperatures.
Kablov, Eugene N; Stolyarova, Valentina L; Lopatin, Sergey I; Vorozhtcov, Viktor A; Karachevtsev, Fedor N; Folomeikin, Yuriy I
2017-03-30
The Gd 2 O 3 -Y 2 O 3 system possesses a number of practical applications, one of the most important of them being production of casting molds for gas turbine engine blades. The components of this system are often added to zirconia or hafnia to obtain high-temperature ceramics which are used for the development of thermal barrier coatings. However, Gd 2 O 3 and Y 2 O 3 are more volatile than zirconia or hafnia and may vaporize selectively during synthesis or usage of high-temperature materials which may lead to changes in their physicochemical properties. Therefore, information on the vaporization processes and thermodynamic properties of the Gd 2 O 3 -Y 2 O 3 system is of great importance. High-temperature Knudsen effusion mass spectrometry was used to study the vaporization processes and to determine the thermodynamic properties of the Gd 2 O 3 -Y 2 O 3 system. Measurements were performed with a MS-1301 mass spectrometer. Vaporization was carried out using a tungsten twin effusion cell containing the sample under study and pure Gd 2 O 3 as a reference substance. Electron ionization at an energy of 25 eV was employed. At the temperature of 2630 K, GdO, YO and O vapor species were identified over the samples in the Gd 2 O 3 -Y 2 O 3 system. The Gd 2 O 3 and Y 2 O 3 activities and the vaporization rates of samples as functions of composition in the Gd 2 O 3 -Y 2 O 3 system were derived from the partial pressures of the vapor species mentioned. Using these data the Gibbs energy of mixing and excess Gibbs energy of the hexagonal solid solution in this system were calculated at 2630 K. The thermodynamic properties of the Gd 2 O 3 -Y 2 O 3 system, such as the activities of components and the excess Gibbs energy, obtained in the present study using Knudsen mass spectrometry at 2630 K, demonstrated significant negative deviations from ideal behavior. The vaporization rates of the samples were found to decrease as the Y 2 O 3 content increased. Copyright © 2016 John
Köster, Andreas; Mausbach, Peter; Vrabec, Jadran
2017-10-01
The Lennard-Jones potential is used to study the high density fluid and face centered cubic solid state region, including solid-fluid equilibria. Numerous thermodynamic properties are considered, elucidating the behavior of matter in this poorly studied region. The present molecular simulation results are extensively compared to the latest and most accurate equation of state models for fluid and solid phases. It is shown that current models do not cover the thermodynamics of the system adequately near the solid-fluid phase transition. Furthermore, thermodynamic stability is analyzed, indicating that published solid-fluid coexistence data may not be correct at high temperatures. Particular attention is paid to the premelting zone, a range of states close to the melting line, which is characterized by strong variations of several thermodynamic properties. Because the underlying microscopic mechanisms are not yet fully understood, it is hoped that these data may contribute to the development of a theoretical framework for describing premelting effects.
Thermodynamical properties of dark energy with the equation of state ω=ω0+ω1z
International Nuclear Information System (INIS)
Zhang Yongping; Yi Zelong; Zhang Tongjie; Liu Wenbiao
2008-01-01
The thermodynamical properties of dark energy are usually investigated with the equation of state ω=ω 0 +ω 1 z. Recent observations show that our Universe is accelerating, and the apparent horizon and the event horizon vary with redshift z. Because definitions of the temperature and entropy of a black hole are used to describe the two horizons of the Universe, we examine the thermodynamical properties of the Universe, which is enveloped by the apparent horizon and the event horizon, respectively. We show that the first and the second laws of thermodynamics inside the apparent horizon in any redshift are satisfied, while they are broken down inside the event horizon in some redshifts. Therefore, the apparent horizon for the Universe may be the boundary of thermodynamical equilibrium for the Universe like the event horizon for a black hole
Electrochemical thermodynamic measurement system
Reynier, Yvan [Meylan, FR; Yazami, Rachid [Los Angeles, CA; Fultz, Brent T [Pasadena, CA
2009-09-29
The present invention provides systems and methods for accurately characterizing thermodynamic and materials properties of electrodes and electrochemical energy storage and conversion systems. Systems and methods of the present invention are configured for simultaneously collecting a suite of measurements characterizing a plurality of interconnected electrochemical and thermodynamic parameters relating to the electrode reaction state of advancement, voltage and temperature. Enhanced sensitivity provided by the present methods and systems combined with measurement conditions that reflect thermodynamically stabilized electrode conditions allow very accurate measurement of thermodynamic parameters, including state functions such as the Gibbs free energy, enthalpy and entropy of electrode/electrochemical cell reactions, that enable prediction of important performance attributes of electrode materials and electrochemical systems, such as the energy, power density, current rate and the cycle life of an electrochemical cell.
Thermodynamic properties and entropy scaling law for diffusivity in soft spheres.
Pieprzyk, S; Heyes, D M; Brańka, A C
2014-07-01
The purely repulsive soft-sphere system, where the interaction potential is inversely proportional to the pair separation raised to the power n, is considered. The Laplace transform technique is used to derive its thermodynamic properties in terms of the potential energy and its density derivative obtained from molecular dynamics simulations. The derived expressions provide an analytic framework with which to explore soft-sphere thermodynamics across the whole softness-density fluid domain. The trends in the isochoric and isobaric heat capacity, thermal expansion coefficient, isothermal and adiabatic bulk moduli, Grüneisen parameter, isothermal pressure, and the Joule-Thomson coefficient as a function of fluid density and potential softness are described using these formulas supplemented by the simulation-derived equation of state. At low densities a minimum in the isobaric heat capacity with density is found, which is a new feature for a purely repulsive pair interaction. The hard-sphere and n = 3 limits are obtained, and the low density limit specified analytically for any n is discussed. The softness dependence of calculated quantities indicates freezing criteria based on features of the radial distribution function or derived functions of it are not expected to be universal. A new and accurate formula linking the self-diffusion coefficient to the excess entropy for the entire fluid softness-density domain is proposed, which incorporates the kinetic theory solution for the low density limit and an entropy-dependent function in an exponential form. The thermodynamic properties (or their derivatives), structural quantities, and diffusion coefficient indicate that three regions specified by a convex, concave, and intermediate density dependence can be expected as a function of n, with a narrow transition region within the range 5 < n < 8.
Energy Technology Data Exchange (ETDEWEB)
Wang, Han, E-mail: wang-han@iapcm.ac.cn [CAEP Software Center for High Performance Numerical Simulation, Huayuan Road 6, 100088 Beijing, China and Zuse Institute Berlin (ZIB), Berlin (Germany); Nakamura, Haruki [Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Fukuda, Ikuo, E-mail: ifukuda@protein.osaka-u.ac.jp [Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
2016-03-21
We performed extensive and strict tests for the reliability of the zero-multipole (summation) method (ZMM), which is a method for estimating the electrostatic interactions among charged particles in a classical physical system, by investigating a set of various physical quantities. This set covers a broad range of water properties, including the thermodynamic properties (pressure, excess chemical potential, constant volume/pressure heat capacity, isothermal compressibility, and thermal expansion coefficient), dielectric properties (dielectric constant and Kirkwood-G factor), dynamical properties (diffusion constant and viscosity), and the structural property (radial distribution function). We selected a bulk water system, the most important solvent, and applied the widely used TIP3P model to this test. In result, the ZMM works well for almost all cases, compared with the smooth particle mesh Ewald (SPME) method that was carefully optimized. In particular, at cut-off radius of 1.2 nm, the recommended choices of ZMM parameters for the TIP3P system are α ≤ 1 nm{sup −1} for the splitting parameter and l = 2 or l = 3 for the order of the multipole moment. We discussed the origin of the deviations of the ZMM and found that they are intimately related to the deviations of the equilibrated densities between the ZMM and SPME, while the magnitude of the density deviations is very small.
International Nuclear Information System (INIS)
Alderson, M.A.H.G.
1975-01-01
An equatuion of state has been produced which covers the entire P.V.T. diagram. Thermodynamic consistency has been maintained at all times. The thermodynamic data are presented in the forms of tables and a temperature-entropy chart. A computer program has been written to produce the tables and can also be built into other computer programs. (author)
Magneto-elastic effects and thermodynamic properties of ferromagnetic hcp Co
International Nuclear Information System (INIS)
Kuang, Fang-Guang; Kuang, Xiao-Yu; Kang, Shu-Ying; Mao, Ai-Jie
2014-01-01
Using first principles projector augmented wave (PAW) potential method, the magneto-elastic effects and thermodynamic properties of ferromagnetic hcp Cobalt at high pressure and temperature are investigated. The calculated elastic constants from PBE+U method demonstrate a noticeable improvement with regard to experimental data. Various physical quantities under high pressure also present significant improvements, such as the bulk modulus, shear modulus, Young's modulus, Debye temperature, various sound velocities and the normalized acoustic velocities in the meridian plane. That is due to the fact that Cobalt system possesses large correlation effects. Meanwhile, the phonon dispersion curves are in excellent agreement with experimental data. It is not observed any anomaly or instability under compression. However, according to the E 2g -phonon frequencies, the obtained pressure variation of C 44 elastic modulus also suggests that the system has miraculous magneto-elastic effects. Moreover, the pressure and temperature dependence of thermodynamic properties are derived within the quasi-harmonic approximation for the first time. The obtained Grüneisen ratio, Anderon–Grüneisen parameter and the volume dependence of Grüneisen ratio display manifestly temperature and pressure dependences.
Solubility and thermodynamic properties of vanillyl alcohol in some pure solvents
International Nuclear Information System (INIS)
Guo, Yanmei; Hao, Yunhui; Zhou, Yanan; Han, Zhengyang; Xie, Chuang; Su, Weiyi; Hao, Hongxun
2017-01-01
Highlights: • The solubilities of vanillyl alcohol in eight pure solvents were determined. • The capability of forming hydrogen bond was applied to explain the solubility data. • Dissolution thermodynamic properties of vanillyl alcohol were calculated and discussed. - Abstract: In this work, the solubility of vanillyl alcohol in eight pure solvents was measured by using a static gravimetric method over the temperature range from 293.15 K to 343.15 K. It was found that the solubility of vanillyl alcohol in ethanol is the highest while solubility in butyl acetate is the least among all the selected solvents. The solubility values increase with the temperature rise. The capability of vanillyl alcohol to form hydrogen bond with solvents was applied to explain the difference of solubility in these selected pure solvents. Furthermore, the modified Apelblat equation, the λh equation and the Wilson equation were used to correlate the experimental solubility. Finally, the thermodynamic properties of vanillyl alcohol in different pure solvents were investigated and are discussed based on the Wilson equation and the experimental solubility date.
Energy Technology Data Exchange (ETDEWEB)
Virot, F., E-mail: francois.virot@irsn.fr; Barrachin, M.; Souvi, S.; Cantrel, L.
2014-10-15
Highlights: • Standard enthalpies of formation of BeH, BeH{sub 2}, BeOH, Be(OH){sub 2} have been calculated. • The impact of hydrogen isotopy on thermodynamic properties has been shown. • Speciation in the vacuum vessel shows that the main tritiated species is tritiated steam. • Beryllium hydroxide and hydride could exist during an accidental event. - Abstract: By quantum chemistry calculations, we have evaluated the standard enthalpies of formation of some gaseous species of the Be-O-H chemical system: BeH, BeH{sub 2}, BeOH, Be(OH){sub 2} for which the values in the referenced thermodynamic databases (NIST-JANAF [1] or COACH [2]) were, due to the lack of experimental data, estimated or reported with a large uncertainty. Comparison between post-HF, DFT approaches and available experimental data allows validation of the ability of an accurate exchange-correlation functional, VSXC, to predict the thermo-chemical properties of the beryllium species of interest. Deviation of enthalpy of formation induced by changes in hydrogen isotopy has been also calculated. From these new theoretically determinated data, we have calculated the chemical speciation in conditions simulating an accident of water ingress in the vacuum vessel of ITER.
Vibrational and thermodynamic properties of β-HMX: a first-principles investigation.
Wu, Zhongqing; Kalia, Rajiv K; Nakano, Aiichiro; Vashishta, Priya
2011-05-28
Thermodynamic properties of β-HMX crystal are investigated using the quasi-harmonic approximation and density functional theory within the local density approximation (LDA), generalized gradient approximation (GGA), and GGA + empirical van der Waals (vdW) correction. It is found that GGA well describes the thermal expansion coefficient and heat capacity but fails to produce correct bulk modulus and equilibrium volume. The vdW correction improves the bulk modulus and volume, but worsens the thermal expansion coefficient and heat capacity. In contrast, LDA describes all thermodynamic properties with reasonable accuracy, and overall is a good exchange-correlation functional for β-HMX molecular crystal. The results also demonstrate significant contributions of phonons to the equation of state. The static calculation of equilibrium volume for β-HMX differs from the room-temperature value incorporating lattice vibrations by over 5%. Therefore, for molecular crystals, it is essential to include phonon contributions when calculated equation of state is compared with experimental data at ambient condition. © 2011 American Institute of Physics
International Nuclear Information System (INIS)
Yang, Peng; Du, Shichao; Qin, Yujia; Zhao, Kaifei; Li, Kangli; Hou, Baohong; Gong, Junbo
2016-01-01
Highlights: • The solubility data of pyraclostrobin in pure and binary solvents were determined and correlated. • The theory of solubility parameter was used to explain the cosolvency in binary solvents. • A modified mixing rule was proposed to calculate the solubility parameter of binary solvents. • The dissolution thermodynamic properties were calculated and discussed. - Abstract: The solubility of pyraclostrobin in five pure solvents and two binary solvent mixtures was measured from 283.15 K to 308.15 K using a static analytical method. Solubility in five pure solvents was well correlated by the modified Apelblat equation and Wilson model. While the CNIBS/R–K model was applied to correlate the solubility in two binary solvent mixtures, the correlation showed good agreement with experimental results. The solubility of pyraclostrobin reaches its maximum value at a certain cyclohexane mole fraction in the two binary solvent mixtures. The solubility parameter of pyraclostrobin was calculated by the Fedors method and a new modified mixing rule with preferable applicability was proposed to determine the solubility parameter of solvents. Then the co-solvency in the binary solvent mixtures can be explained based on the obtained solubility parameters. In a addition, the dissolution thermodynamic properties were calculated from the experimental values using the Wilson model.
International Nuclear Information System (INIS)
Lima, R.A.T. de.
1982-01-01
Within the variational method in statistical mechanics, dynamical and thermodynamical properties of anharmonic crystal are discussed, in particular the thermal behavior of the crystalline expasion, phonons spectrum, specific heat and Debye-Weller factor (which satisfctorily describes the experimental data). Through the temperature dependent Green functions framework, dynamical and thermodynamical properties associated with the spin-Peierls transition in the magnetostrictive XY model (with one-dimensional magnetic interactions but structurally three-dimensional) are also discussed. Emphasis is given to the influence of an external magnetic field (along the z-axis) on the structural order parameter, phase diagram, specific heat, magnetization, magnetic susceptibility and phonons spectrun (acoustic and optic branches). Results are extended and new ons are exhibited such as: a) a structural Lifshitz point, which separates the uniform (U), dimerized (D) and modulated (M) phases in the T-H phase diagram; b) another special point is detected for high magnetic fields; c) the D-M first-order frontier and the metastability limits are obtained; d) for high elastic constants, fixed temperature and increasing magnetic field, the unusual sequence non uniform-uniform - non uniform-uniform is possible; e) the thermal dependence of the sound velocity presents a gap at the critical temperature. The present results have provided a quite satisfactory qualitative (and partially quantitative) description of the experiments on the TTF-BDT and MEM-(TCNQ) 2 ; this fact enables us to hope that several of our predictions indeed occur in nature. (Author) [pt
Atomistic modeling of thermodynamic properties of Pu-Ga alloys based on the Invar mechanism
Lee, Tongsik; Taylor, Christopher D.; Lawson, A. C.; Conradson, Steven D.; Chen, Shao Ping; Caro, A.; Valone, Steven M.; Baskes, Michael I.
2014-05-01
We present an atomistic model that accounts for a range of anomalous thermodynamic properties of the fcc δ phase of Pu-Ga alloys in terms of the Invar mechanism. Two modified embedded atom method potentials are employed to represent competing electronic states in δ-Pu, each of which has an individual configuration dependence as well as distinct interactions with gallium. Using classical Monte Carlo simulations, we compute the temperature dependence of various thermodynamic properties for different dilute gallium concentrations. The model reproduces the observed effects of excessive volume reduction along with a rapid shift in thermal expansion from negative to positive values with increasing gallium concentration. It also predicts progressive stiffening upon dilute-gallium alloying, while the calculated thermal softening is nearly independent of the gallium concentration in agreement with resonant ultrasound spectroscopy measurements in the literature. Analysis of the local structure predicted by the model indicates that the distribution of the gallium atoms is not completely random in the δ phase due to the presence of short-range order associated with the Invar mechanism. This effect is consistent with the nanoscale heterogeneity in local gallium concentration which is observed in recent extended x-ray absorption fine structure spectroscopy experiments. Implications of the Invar effect for phase stability and physical interpretations of the two states are also discussed.
Thermodynamic and transport properties of nitrogen fluid: Molecular theory and computer simulations
Eskandari Nasrabad, A.; Laghaei, R.
2018-04-01
Computer simulations and various theories are applied to compute the thermodynamic and transport properties of nitrogen fluid. To model the nitrogen interaction, an existing potential in the literature is modified to obtain a close agreement between the simulation results and experimental data for the orthobaric densities. We use the Generic van der Waals theory to calculate the mean free volume and apply the results within the modified Cohen-Turnbull relation to obtain the self-diffusion coefficient. Compared to experimental data, excellent results are obtained via computer simulations for the orthobaric densities, the vapor pressure, the equation of state, and the shear viscosity. We analyze the results of the theory and computer simulations for the various thermophysical properties.
Energy Technology Data Exchange (ETDEWEB)
Kim, Soon Chul; Suh, Song Hyuck; Min, Yoong Ki; Ahn, Eun Ju [Andong National University, Andong (Korea)
2002-03-01
Two non-ionic surfactants, which are the non-ionic surfactants with the polydisperse properties and non-ionic surfactant with the ellipsoidal structure, and which were measured by the small-angle neutron scattering installed in the Korea Atomic Energy Research Institute have been analyzed by using the IGOR Program code. Through the analysis of the SANS data, the strengths and weaknesses of the IGOR program code have been tested in details. To reinforce the IGOR program, the computer programs which are based on the Percus-Yevick, hypernetted-chain, Rogers-Young, and density functional approximation have been developed for the model micelles, and their results have been compared with the computer simulations. It is expected that this study would be applied to study the thermodynamic and structural properties of polymers with the complex structure. 22 refs., 20 figs., 7 tabs. (Author)
International Nuclear Information System (INIS)
Murphy, R.W.
1992-01-01
Magneto-thermodynamic property characterizations were selected, adapted, and compared to material property data for gadolinium gallium garnet in the temperature range 4--40 K and magnetic field range 0--6 T. The most appropriate formulations were incorporated into a model in which methods similar to those previously developed for other materials and temperature ranges were used to make limitation and relative performance assessments of Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. Analysis showed that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as those for materials previously examined, substantial improvements in cooling capacity/temperature lift combinations can be achieved using regenerative cycles within specified fields limits if significant loss mechanisms are mitigated
International Nuclear Information System (INIS)
Ionova, G.; Rabbe, C.; Charbonnel, M.C.; Hill, C.; Guillaumont, D.; Guillaumont, R.; Ionov, S.; Madic, C.
2004-01-01
We report here the results obtained from a systematic theoretical study on the thermodynamic properties of trivalent lanthanide (Ln) and actinide (An) complexes with chelating nitrogen tridentate ligands. The mechanism of chelation has been investigated and the role of cation dissolution is investigated through a comparison of the thermodynamic properties of solvated cations and complexes. The difference in thermodynamic properties of LnL and AnL complexes is analyzed. (authors)
Directory of Open Access Journals (Sweden)
Iván Vera-Romero
2017-06-01
Full Text Available The design and optimization of energy systems are very important today. Some of these systems use the ammonia-water mixture as working fluid, therefore, calculation of the thermodynamic properties becomes indispensable for its evaluation, design and optimization. In the present work an application has been developed in ExcelTM using Visual Basic (VBA from a formulation based on free Gibbs Energy of Excess, in order to simulate different systems such as cooling, air conditioning, heat pumps, cogeneration and power cycles, without to acquire commercial simulators for this purpose. To validate this program, the results were compared with data obtained by the National Institute of Standards and Technology (NIST software and experimental data reported in the literature.
Thermodynamics for scientists and engineers
International Nuclear Information System (INIS)
Lim, Gyeong Hui
2011-02-01
This book deals with thermodynamics for scientists and engineers. It consists of 11 chapters, which are concept and background of thermodynamics, the first law of thermodynamics, the second law of thermodynamics and entropy, mathematics related thermodynamics, properties of thermodynamics on pure material, equilibrium, stability of thermodynamics, the basic of compound, phase equilibrium of compound, excess gibbs energy model of compound and activity coefficient model and chemical equilibrium. It has four appendixes on properties of pure materials and thermal mass.
International Nuclear Information System (INIS)
Prieur, D.
2011-01-01
Fuel irradiation in pressurized water reactors lead to the formation of fission products and minor actinides (Np, Am, Cm) which can be transmuted in fast neutrons reactors. In this context, the aim of this work was to study the fabrication conditions of the U 1-y Am y O 2+x fuels which exhibit particular thermodynamical properties requiring an accurate monitoring of the oxygen potential during the sintering step. For this reason, a thermodynamical model was developed to assess the optimum sintering conditions for these materials. From these calculations, U 1-y Am y O 2+x (y=0.10; 0.15; 0.20; 0.30) were sintered in two range of atmosphere. In hyper-stoichiometric conditions at low temperature, porous and multiphasic compounds are obtained whereas in reducing conditions at high temperature materials are dense and monophasic. XAFS analyses were performed in order to obtain additional experimental data for the thermodynamical modeling refinement. These characterizations also showed the reduction of Am(+IV) to Am(+III) and the partial oxidation of U(+IV) to U(+V) due to a charge compensation mechanism occurring during the sintering. Finally, taking into account the high - activity of Am, self-irradiation effects were studied for two types of microstructures and two Am contents (10 and 15%). For each composition, a lattice parameter increase was observed without structural change coupled with a macroscopic swelling of the pellet diameter up to 1.2% for the dense compounds and 0.6% for the tailored porosity materials. (author) [fr
Chakraborty, Anutosh; Saha, Bidyut Baran; Ng, Kim Choon; Koyama, Shigeru; Srinivasan, Kandadai
2009-02-17
Thermodynamic property surfaces for a single-component adsorbent+adsorbate system are derived and developed from the viewpoint of classical thermodynamics, thermodynamic requirements of chemical equilibrium, Gibbs law, and Maxwell relations. They enable us to compute the entropy and enthalpy of the adsorbed phase, the isosteric heat of adsorption, specific heat capacity, and the adsorbed phase volume thoroughly. These equations are very simple and easy to handle for calculating the energetic performances of any adsorption system. We have shown here that the derived thermodynamic formulations fill up the information gap with respect to the state of adsorbed phase to dispel the confusion as to what is the actual state of the adsorbed phase. We have also discussed and established the temperature-entropy diagrams of (i) CaCl2-in-silica gel+water system for cooling applications, and (ii) activated carbon (Maxsorb III)+methane system for gas storage.
Chakraborty, Anutosh
2009-02-17
Thermodynamic property surfaces for a single-component adsorbent + adsorbate system are derived and developed from the viewpoint of classical thermodynamics, thermodynamic requirements of chemical equilibrium, Gibbs law, and Maxwell relations. They enable us to compute the entropy and enthalpy of the adsorbed phase, the isosteric heat of adsorption, specific heat capacity, and the adsorbed phase volume thoroughly. These equations are very simple and easy to handle for calculating the energetic performances of any adsorption system. We have shown here that the derived thermodynamic formulations fill up the information gap with respect to the state of adsorbed phase to dispel the confusion as to what is the actual state of the adsorbed phase. We have also discussed and established the temperature-entropy diagrams of (i) CaCl 2-in-silica gel + water system for cooling applications, and (ii) activated carbon (Maxsorb III) + methane system for gas storage. © Copyright 2009 American Chemical Society.
Technologically important properties of lactic acid bacteria isolated ...
African Journals Online (AJOL)
Technologically important properties of lactic acid bacteria isolated from raw milk of three breeds of Algerian dromedary ( Camelus dromedarius ) ... isolated from Algerian dromedary milks that showed potentially important properties suggest that they are good candidate for camels milk processing or other dairy fermentation ...
Electronic, thermodynamics and mechanical properties of LaB6 from first-principles
Ivashchenko, V. I.; Turchi, P. E. A.; Shevchenko, V. I.; Medukh, N. R.; Leszczynski, Jerzy; Gorb, Leonid
2018-02-01
Up to date, the electronic structure properties of amorphous lanthanum hexaboride, a-LaB6, were not yet investigated, and the thermodynamic and mechanical properties of crystalline lanthanum hexaboride (c-LaB6) were studied incompletely. The goal of this work was to fill these gaps in the study of lanthanum hexaborides. The electronic and phonon structures, thermodynamic and mechanical properties of both crystalline and amorphous lanthanum hexaborides (c-LaB6, a-LaB6, respectively) were investigated within the density functional theory. An amorphyzation of c-LaB6 gives rise to the metal - semiconductor transition. The thermal conductivity decreases on going from c-LaB6 to a-LaB6. The elastic moduli, hardness, ideal tensile and shear strengths of a-LaB6 are significantly lower compared to those of the crystalline counterpart, despite the formation of the icosahedron-like boron network in the amorphous phase. For c-LaB6, the stable boron octahedrons are preserved after the failure under tensile and shear strains. The peculiarity in the temperature dependence of heat capacity, Cp(T), at 50 K is explained by the availability of a sharp peak at 100 cm-1 in the phonon density of states of c-LaB6. An analysis of the Fermi surface indicates that this peak is not related to the shape of the Fermi surface, and is caused by the vibration of lanthanum atoms. In the phonon spectrum of a-LaB6, the peak at 100 cm-1 is significantly broader than in the spectrum of c-LaB6, for which reason the anomaly in the Cp(T) dependence of a-LaB6 does not appear. The calculated characteristics are in good agreement with the available experimental data.
Directory of Open Access Journals (Sweden)
Ravikiran Allada
2017-01-01
Full Text Available Aims: Carvedilol phosphate (CDP is a nonselective beta-blocker used for the treatment of heart failures and hypertension. In this work, moisture sorption–desorption characteristics and thermodynamic properties of CDP have been investigated. Materials and Methods: The isotherms were determined using dynamic vapor sorption analyzer at different humidity conditions (0%–90% relative humidity and three pharmaceutically relevant temperatures (20°C, 30°C, and 40°C. The experimental sorption data determined were fitted to various models, namely, Brunauer–Emmett–Teller; Guggenheim-Anderson-De Boer (GAB; Peleg; and modified GAB. Isosteric heats of sorption were evaluated through the direct use of sorption isotherms by means of the Clausius-Clapeyron equation. Statistical Analysis Used: The sorption model parameters were determined from the experimental sorption data using nonlinear regression analysis, and mean relative percentage deviation (P, correlation (Correl, root mean square error, and model efficiency were considered as the criteria to select the best fit model. Results: The sorption–desorption isotherms have sigmoidal shape – confirming to Type II isotherms. Based on the statistical data analysis, modified GAB model was found to be more adequate to explain sorption characteristics of CDP. It is noted that the rate of adsorption and desorption is specific to the temperature at which it was being studied. It is observed that isosteric heat of sorption decreased with increasing equilibrium moisture content. Conclusions: The calculation of the thermodynamic properties was further used to draw an understanding of the properties of water and energy requirements associated with the sorption behavior. The sorption–desorption data and the set of equations are useful in the simulation of processing, handling, and storage of CDP and further behavior during manufacture and storage of CDP formulations.
Han, Bumsoo; Bischof, John C
2004-04-01
Understanding the phase change behavior of biomaterials during freezing/thawing including their thermal properties at low temperatures is essential to design and improve cryobiology applications such as cryopreservation and cryosurgery. However, knowledge of phase change behavior and thermal properties of various biomaterials is still incomplete, especially at cryogenic temperatures (solutions--either water-NaCl or phosphate buffered saline (PBS)--with various chemical additives were investigated. The chemical additives studied are glycerol and raffinose as CPAs, an AFP (Type III, molecular weight = 6500), and NaCl as a cryosurgical adjuvant. The phase change behavior was investigated using a differential scanning calorimeter (DSC) and a cryomicroscope. The specific and latent heat of these solutions were also measured with the DSC. The saline solutions have two distinct phase changes--water/ice and eutectic phase changes. During freezing, eutectic solidification of both water-NaCl and PBS are significantly supercooled below their thermodynamic equilibrium eutectic temperatures. However, their melting temperatures are close to thermodynamic equilibrium during thawing. These eutectic phase changes disappear when even a small amount (0.1 M glycerol) of CPA was added, but they are still observed after the addition of an AFP. The specific heats of these solutions are close to that of ice at very low temperatures (< or = -100 degrees C) regardless of the additives, but they increase between -100 degrees C and -30 degrees C with the addition of CPAs. The amount of latent heat, which is evaluated with sample weight, generally decreases with the addition of the additives, but can be normalized to approximately 300 J/g based on the weight of water which participates in the phase change. This illustrates that thermal properties, especially latent heat, of a biomaterial should be evaluated based on the understanding of its phase change behavior. The results of the present
Structure, thermodynamic properties, and phase diagrams of few colloids confined in a spherical pore
Paganini, Iván E.; Pastorino, Claudio; Urrutia, Ignacio
2015-06-01
We study a system of few colloids confined in a small spherical cavity with event driven molecular dynamics simulations in the canonical ensemble. The colloidal particles interact through a short range square-well potential that takes into account the basic elements of attraction and excluded-volume repulsion of the interaction among colloids. We analyze the structural and thermodynamic properties of this few-body confined system in the framework of inhomogeneous fluids theory. Pair correlation function and density profile are used to determine the structure and the spatial characteristics of the system. Pressure on the walls, internal energy, and surface quantities such as surface tension and adsorption are also analyzed for a wide range of densities and temperatures. We have characterized systems from 2 to 6 confined particles, identifying distinctive qualitative behavior over the thermodynamic plane T - ρ, in a few-particle equivalent to phase diagrams of macroscopic systems. Applying the extended law of corresponding states, the square well interaction is mapped to the Asakura-Oosawa model for colloid-polymer mixtures. We link explicitly the temperature of the confined square-well fluid to the equivalent packing fraction of polymers in the Asakura-Oosawa model. Using this approach, we study the confined system of few colloids in a colloid-polymer mixture.
Paganini, Iván E; Pastorino, Claudio; Urrutia, Ignacio
2015-06-28
We study a system of few colloids confined in a small spherical cavity with event driven molecular dynamics simulations in the canonical ensemble. The colloidal particles interact through a short range square-well potential that takes into account the basic elements of attraction and excluded-volume repulsion of the interaction among colloids. We analyze the structural and thermodynamic properties of this few-body confined system in the framework of inhomogeneous fluids theory. Pair correlation function and density profile are used to determine the structure and the spatial characteristics of the system. Pressure on the walls, internal energy, and surface quantities such as surface tension and adsorption are also analyzed for a wide range of densities and temperatures. We have characterized systems from 2 to 6 confined particles, identifying distinctive qualitative behavior over the thermodynamic plane T - ρ, in a few-particle equivalent to phase diagrams of macroscopic systems. Applying the extended law of corresponding states, the square well interaction is mapped to the Asakura-Oosawa model for colloid-polymer mixtures. We link explicitly the temperature of the confined square-well fluid to the equivalent packing fraction of polymers in the Asakura-Oosawa model. Using this approach, we study the confined system of few colloids in a colloid-polymer mixture.
Aerosol effect on the evolution of the thermodynamic properties of warm convective cloud fields
Dagan, Guy; Koren, Ilan; Altaratz, Orit; Heiblum, Reuven H.
2016-12-01
Convective cloud formation and evolution strongly depend on environmental temperature and humidity profiles. The forming clouds change the profiles that created them by redistributing heat and moisture. Here we show that the evolution of the field’s thermodynamic properties depends heavily on the concentration of aerosol, liquid or solid particles suspended in the atmosphere. Under polluted conditions, rain formation is suppressed and the non-precipitating clouds act to warm the lower part of the cloudy layer (where there is net condensation) and cool and moisten the upper part of the cloudy layer (where there is net evaporation), thereby destabilizing the layer. Under clean conditions, precipitation causes net warming of the cloudy layer and net cooling of the sub-cloud layer (driven by rain evaporation), which together act to stabilize the atmosphere with time. Previous studies have examined different aspects of the effects of clouds on their environment. Here, we offer a complete analysis of the cloudy atmosphere, spanning the aerosol effect from instability-consumption to enhancement, below, inside and above warm clouds, showing the temporal evolution of the effects. We propose a direct measure for the magnitude and sign of the aerosol effect on thermodynamic instability.
International Nuclear Information System (INIS)
Fang Zheng; Qiu Guanzhou
2007-01-01
A metallic solution model with adjustable parameter k has been developed to predict thermodynamic properties of ternary systems from those of its constituent three binaries. In the present model, the excess Gibbs free energy for a ternary mixture is expressed as a weighted probability sum of those of binaries and the k value is determined based on an assumption that the ternary interaction generally strengthens the mixing effects for metallic solutions with weak interaction, making the Gibbs free energy of mixing of the ternary system more negative than that before considering the interaction. This point is never considered in the models currently reported, where the only difference in a geometrical definition of molar values of components is considered that do not involve thermodynamic principles but are completely empirical. The current model describes the results of experiments very well, and by adjusting the k value also agrees with those from models used widely in the literature. Three ternary systems, Mg-Cu-Ni, Zn-In-Cd, and Cd-Bi-Pb are recalculated to demonstrate the method of determining k and the precision of the model. The results of the calculations, especially those in Mg-Cu-Ni system, are better than those predicted by the current models in the literature
Thermodynamic properties of copper compounds with oxygen and hydrogen from first principles
International Nuclear Information System (INIS)
Korzhavyi, P.A.; Johansson, B.
2010-02-01
We employ quantum-mechanical calculations (based on density functional theory and linear response theory) in order to test the mechanical and chemical stability of several solid-state configurations of Cu 1+ , Cu 2+ , O 2- , H 1- , and H 1+ ions. We begin our analysis with cuprous oxide (Cu 2 O, cuprite structure), cupric oxide (CuO, tenorite structure), and cuprous hydride (CuH, wurtzite and sphalerite structures) whose thermodynamic properties have been studied experimentally. In our calculations, all these compounds are found to be mechanically stable configurations. Their formation energies calculated at T = 0 K (including the energy of zero-point and thermal motion of the ions) and at room temperature are in good agreement with existing thermodynamic data. A search for other possible solid-state conformations of copper, hydrogen, and oxygen ions is then performed. Several candidate structures for solid phases of cuprous oxy-hydride (Cu 4 H 2 O) and cupric hydride (CuH 2 ) have been considered but found to be dynamically unstable. Cuprous oxy-hydride is found to be energetically unstable with respect to decomposition onto cuprous oxide and cuprous hydride. Metastability of cuprous hydroxide (CuOH) is established in our calculations. The free energy of CuOH is calculated to be some 50 kJ/mol higher than the average of the free energies of Cu 2 O and water. Thus, cuprite Cu 2 O is the most stable of the examined Cu(I) compounds
Fessler, T. E.
1977-01-01
A computer program subroutine, FLUID, was developed to calculate thermodynamic and transport properties of pure fluid substances. It provides for determining the thermodynamic state from assigned values for temperature-density, pressure-density, temperature-pressure, pressure-entropy, or pressure-enthalpy. Liquid or two-phase (liquid-gas) conditions are considered as well as the gas phase. A van der Waals model is used to obtain approximate state values; these values are then corrected for real gas effects by model-correction factors obtained from tables based on experimental data. Saturation conditions, specific heat, entropy, and enthalpy data are included in the tables for each gas. Since these tables are external to the FLUID subroutine itself, FLUID can implement any gas for which a set of tables has been generated. (A setup phase is used to establish pointers dynamically to the tables for a specific gas.) Data-table preparation is described. FLUID is available in both SFTRAN and FORTRAN
Energy Technology Data Exchange (ETDEWEB)
Ikhdair, Sameer M., E-mail: sikhdair@neu.edu.tr [Department of Electrical and Electronic Engineering, Near East University, 922022 Nicosia, Northern Cyprus (Turkey); Department of Physics, Faculty of Science, An-Najah National University, New Campus, Nablus, West Bank, Palestine (Country Unknown); Falaye, Babatunde J., E-mail: fbjames11@physicist.net [Theoretical Physics Section, Department of Physics, University of Ilorin, P.M.B. 1515, Ilorin (Nigeria)
2013-06-27
Highlights: • Solutions of Schrödinger equation in the presence of Pöschl–Teller potential is obtained. • Solutions of Dirac equation in the presence of Pöschl–Teller potential is obtained. • Rotational and vibrational energy eigenvalues of some diatomic molecules are calculated. • Thermodynamics properties of some diatomic molecules are obtained. - Abstract: We apply the asymptotic iteration method (AIM) to obtain the solutions of Schrödinger equation in the presence of Pöschl–Teller (PT) potential. We also obtain the solutions of Dirac equation for the same potential under the condition of spin and pseudospin (p-spin) symmetries. We show that in the nonrelativistic limits, the solution of Dirac system converges to that of Schrödinger system. Rotational and vibrational energy eigenvalues of some diatomic molecules are calculated. Some special cases of interest are studied such as S-wave case, reflectionless-type potential and symmetric hyperbolic PT potential. Furthermore, we present a high temperature partition function in order to study the behavior of the thermodynamic functions such as the vibrational mean energy U, specific heat C, free energy F and entropy S.
Xiao-Lin, Zhang; Yuan-Yuan, Wu; Xiao-Hong, Shao; Yong, Lu; Ping, Zhang
2016-05-01
The high pressure behaviors of Th4H15 and ThH2 are investigated by using the first-principles calculations based on the density functional theory (DFT). From the energy-volume relations, the bct phase of ThH2 is more stable than the fcc phase at ambient conditions. At high pressure, the bct ThH2 and bcc Th4H15 phases are more brittle than they are at ambient pressure from the calculated elastic constants and the Poisson ratio. The thermodynamic stability of the bct phase ThH2 is determined from the calculated phonon dispersion. In the pressure domain of interest, the phonon dispersions of bcc Th4H15 and bct ThH2 are positive, indicating the dynamical stability of these two phases, while the fcc ThH2 is unstable. The thermodynamic properties including the lattice vibration energy, entropy, and specific heat are predicted for these stable phases. The vibrational free energy decreases with the increase of the temperature, and the entropy and the heat capacity are proportional to the temperature and inversely proportional to the pressure. As the pressure increases, the resistance to the external pressure is strengthened for Th4H15 and ThH2. Project supported by the Long-Term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China.
Sun, Xinjun; Liu, Changdong; Guo, Yongliang; Sun, Deyan; Ke, Xuezhi
2018-03-01
The structural and thermodynamic properties of titanium nitride (TiN) have been investigated by merging first-principles calculations and particle-swarm algorithm. The three phases are identified for TiN, including the B1, the P63 / mmc, and the B2 phases. A new phase of anti-TiP structure with the space group P63 / mmc has been predicted. The calculated phase transition from the B1 to the P63 / mmc occurs at 270 GPa. The vibrational, elastic, and thermodynamic properties for the three phases have been calculated and discussed.
Elastic, mechanical, and thermodynamic properties of Bi-Sb binaries: Effect of spin-orbit coupling
Singh, Sobhit; Valencia-Jaime, Irais; Pavlic, Olivia; Romero, Aldo H.
2018-02-01
Using first-principles calculations, we systematically study the elastic stiffness constants, mechanical properties, elastic wave velocities, Debye temperature, melting temperature, and specific heat of several thermodynamically stable crystal structures of BixSb1 -x (0
Thermodynamic properties and equation of state of liquid lead and lead bismuth eutectic
Sobolev, V. P.; Schuurmans, P.; Benamati, G.
2008-06-01
Since the 1950s, liquid lead (Pb) and lead-bismuth eutectic (Pb-Bi) have been studied in the USA, Canada and in the former-USSR as potential coolants for nuclear installations due to their very attractive thermophysical and neutronic properties. However, experimental data on the thermal properties of these coolants in the temperature range of interest are still incomplete and often contradictory. This makes it very difficult to perform design calculations and to analyse the normal and abnormal behaviour of nuclear installations where these coolants are expected to be used. Recently, a compilation of heavy liquid metal (HLM) properties along with recommendations for its use was prepared by the OECD/NEA Working Party on Fuel Cycle (WPFC) Expert Group on Lead-Bismuth Eutectic Technology. A brief review of this compilation and some new data are presented in this article. A set of correlations for the temperature dependence of the main thermodynamic properties of Pb and Pb-Bi(e) at normal pressure, and a set of simplified thermal and caloric equations of state for the liquid phase are proposed.
Thermodynamic properties of stoichiometric lithium cobaltite LiCoO2
International Nuclear Information System (INIS)
Jankovský, Ondřej; Kovařík, Jan; Leitner, Jindřich; Růžička, Květoslav; Sedmidubský, David
2016-01-01
Highlights: • Lithium cobaltite LiCoO 2 was prepared and its structure was refined. • Thermodynamic properties were measured by PPMS, DSC and drop calorimetry. • The heat capacity was analyzed using Debye–Einstein model. • Magnetic properties of LiCoO 2 were measured by vibrating sample magnetometer in PPMS. - Abstract: Lithium cobaltite LiCoO 2 was prepared by solid state route and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), magnetic properties measurement and simultaneous thermal analysis (STA). The heat capacity and enthalpy increments were measured by physical property measurement system (PPMS), differential scanning calorimetry (DSC) and drop calorimetry. The oxygen non-stoichiometry was determined using thermogravimetric measurement (TG). Above room temperature the temperature dependence of the molar heat capacity was derived by simultaneous least squares method from DSC and enthalpy data. The heat capacity was also analyzed in terms of a combined Debye–Einstein model. The molar entropy was evaluated from the low temperature heat capacity data.
International Nuclear Information System (INIS)
Apelblat, Alexander; Korin, Eli; Manzurola, Emanuel
2013-01-01
Highlights: • Over a wide range of concentrations and temperatures sound velocities were measured in aqueous solutions of citric acid. • Compressibility properties of citric acid solutions are thermodynamically characterized. • Changes in the structure of water when citric acid is dissolved are discussed. -- Abstract: Sound velocities in aqueous solutions of citric acid were measured from 15 °C to 50 °C in 5 °C intervals, within the 0.1 mol · kg −1 to 5.0 mol · kg −1 concentration range. These sound velocities served to evaluate the isentropic and isothermal compressibilities, the apparent molar compressibilities, the isochoric thermal pressure coefficients, changes of the cubic expansion coefficients with pressure at constant temperature, the changes of heat capacities with volume and hydration numbers of citric acid in aqueous solutions
Retrieval behavior and thermodynamic properties of symmetrically diluted Q-Ising neural networks
Theumann, W. K.; Erichsen, R., Jr.
2001-12-01
The retrieval behavior and thermodynamic properties of symmetrically diluted Q-Ising neural networks are derived and studied in replica-symmetric mean-field theory generalizing earlier works on either the fully connected or the symmetrical extremely diluted network. Capacity-gain parameter phase diagrams are obtained for the Q=3, Q=4, and Q=∞ state networks with uniformly distributed patterns of low activity in order to search for the effects of a gradual dilution of the synapses. It is shown that enlarged regions of continuous changeover into a region of optimal performance are obtained for finite stochastic noise and small but finite connectivity. The de Almeida-Thouless lines of stability are obtained for arbitrary connectivity, and the resulting phase diagrams are used to draw conclusions on the behavior of symmetrically diluted networks with other pattern distributions of either high or low activity.
Comparison of mechanical and thermodynamic properties of fcc and bcc titanium under high pressure
Zhang, Yongmei; Zhao, Yuhong; Hou, Hua; Wen, Zhiqin; Duan, Meiling
2018-02-01
The mechanical and thermodynamic properties of fcc and bcc Ti have been discussed based on the first-principles calculation combined with the quasi-harmonic Debye model. We find that the bulk modulus B, shear modulus G, Young’s modulus E of fcc Ti are larger, while Poisson’s ratio σ is smaller than that of bcc Ti under the same pressure, which indicates the better mechanical performance of fcc Ti compared with bcc Ti. The values of B/G and σ indicate that mechanically stable fcc structure is much less ductile than the bcc structure, while mechanically metastable fcc structure has better ductility than stable bcc structure under high pressure. The normalized volume, isothermal bulk modulus, heat capacity, volume thermal expansion coefficient and Debye temperature under pressure and temperature for fcc and bcc Ti are predicted.
Structural, dynamical and thermodynamic properties of CdXP2 (X = Si, Ge) from first principles
Hou, H. J.; Zhu, H. J.; Li, S. P.; Li, T. J.; Tian, L.; Yang, J. W.
2018-03-01
The structural, elastic, dynamical and thermodynamic properties of CdXP2 (X = Si, Ge) with chalcopyrite semiconductors have been calculated by using the projector augmented wave method within the generalized gradient approximation. The obtained lattice constants and elastic constants of CdXP2 (X = Si, Ge) are compared with the available experimental and other theoretical results, and the agreements between them are quite well. Also, the elastic anisotropy of CdXP2 (X = Si, Ge) have been evaluated. In addition, the phonon dispersion curves and the corresponding phonon density of states of CdXP2 (X = Si, Ge) have been determined by virtue of a linear response approach to density functional perturbation theory method successfully. Finally, the Helmholtz free energy F, internal energy E, entropy S and the constant volume specific heat C V have also been predicted based on quasi-harmonic approximation.
Ab initio calculation of the thermodynamic properties of InSb under intense laser irradiation
International Nuclear Information System (INIS)
Feng, ShiQuan; Cheng, XinLu; Zhao, JianLing; Zhang, Hong
2013-01-01
In this paper, phonon spectra of InSb at different electronic temperatures are presented. Based on the phonon dispersion relationship, we further perform a theoretical investigation of the thermodynamic properties of InSb under intense laser irradiation. The phonon entropy, phonon heat capacity, and phonon contribution to Helmholtz free energy and internal energy of InSb are calculated as functions of temperature at different electronic temperatures. The abrupt change in the phonon entropy- temperature curve from T e = 0.75 to 1.0 eV provides an indication of InSb undergoing a phase transition from solid to liquid. It can be considered as a collateral evidence of non-thermal melting for InSb under intense electronic excitation effect
Ab initio calculation of the thermodynamic properties of InSb under intense laser irradiation
Feng, ShiQuan; Zhao, JianLing; Cheng, XinLu; Zhang, Hong
2013-07-01
In this paper, phonon spectra of InSb at different electronic temperatures are presented. Based on the phonon dispersion relationship, we further perform a theoretical investigation of the thermodynamic properties of InSb under intense laser irradiation. The phonon entropy, phonon heat capacity, and phonon contribution to Helmholtz free energy and internal energy of InSb are calculated as functions of temperature at different electronic temperatures. The abrupt change in the phonon entropy- temperature curve from Te = 0.75 to 1.0 eV provides an indication of InSb undergoing a phase transition from solid to liquid. It can be considered as a collateral evidence of non-thermal melting for InSb under intense electronic excitation effect.
Thermodynamic properties of non-conformal soft-sphere fluids with effective hard-sphere diameters.
Rodríguez-López, Tonalli; del Río, Fernando
2012-01-28
In this work we study a set of soft-sphere systems characterised by a well-defined variation of their softness. These systems represent an extension of the repulsive Lennard-Jones potential widely used in statistical mechanics of fluids. This type of soft spheres is of interest because they represent quite accurately the effective intermolecular repulsion in fluid substances and also because they exhibit interesting properties. The thermodynamics of the soft-sphere fluids is obtained via an effective hard-sphere diameter approach that leads to a compact and accurate equation of state. The virial coefficients of soft spheres are shown to follow quite simple relationships that are incorporated into the equation of state. The approach followed exhibits the rescaling of the density that produces a unique equation for all systems and temperatures. The scaling is carried through to the level of the structure of the fluids.
Acoustic and Thermodynamic Properties of the Binary Liquid Mixture n-Octane + n-Dodecane
Khasanshin, T. S.; Golubeva, N. V.; Samuilov, V. S.; Shchemelev, A. P.
2014-01-01
The velocity of sound in the binary liquid mixture n-octane + n-dodecane has been investigated by the method of direct measurement of the pulse-transmission time in the interval of temperatures 298-433 K and pressures 0.1-100.1 MPa. The maximum measurement error amounts to 0.1%. The density, isobaric expansion coefficient, isobaric and isochoric heat capacities, and isothermal compressibility of a mixture of three compositions have been determined in the intervals of temperatures 298-393 K and pressures 0.1-100 MPa from the data on the velocity of sound. Also, the excess molar volume, the excess isothermal compressibility, and the deviation of the velocity of sound from its value for an ideal liquid have been determined. The coefficients of the Tate equation have been computed in the above temperature interval. A table of thermodynamic properties of the mixture has been presented.
Acoustic and thermodynamic properties of the binary liquid system n-dodecane+ n-hexadecane
Khasanshin, T. S.; Samuilov, V. S.; Shchemelev, A. P.; Mosbach, F. M.
2010-11-01
By the method of direct measurement of the pulse-passage time, the velocity of sound in a binary liquid mixture n-dodecane+ n-hexadecane has been investigated in the temperature range 298-433 K and in the pressure range 0.1-100.1 MPa. The maximum measurement error is 0.1%. Experimental data on the velocity of sound for the investigated mixture have been obtained for the first time. On the basis of the data on the velocity of sound, we have determined the density, the isobaric expansion coefficient, the isobaric and isochoric heat capacities, and the isothermal compressibility coefficient of a mixture of three compositions in the 298-433 K temperature range and in the 0.1-100.1 MPa range of pressures. The coefficients of the Tate equations in the above range of parameters have been calculated. A table of thermodynamic properties of the mixture is presented.
Study of thermodynamic water properties and moisture sorption hysteresis of mango skin
Directory of Open Access Journals (Sweden)
Silvio José Ferreira de Souza
2015-03-01
Full Text Available The equilibrium moisture content for adsorption and desorption isotherms of mango skin was determined using the static gravimetric method at temperatures of 20, 26, 33, 38 and 44 oC in the 0.056 to 0.873 water activity range. Both sorption curves show a decrease in equilibrium moisture content as the temperature increasing. The hysteresis effect was observed at constant water activity. The Guggenheim, Anderson, and de Boer (GAB model presented the best fitting accuracy among a group of models and was used to determine the thermodynamic properties of water sorption. Integral enthalpy and integral entropy areas showed inverted values for the adsorption and desorption isotherms over the wide range of water activity studied. These values confirm, in energetic terms, the difference between adsorption and desorption isotherms observed in the hysteresis phenomenon. Finally, the Gibbs free energy revealed that the sorption process was spontaneous for both sorption isotherms.
International Nuclear Information System (INIS)
Fortin, Xavier
1971-01-01
The effects of thermal excitation are introduced in the study of a simple electronic structure model for condensed media. The choice of a particle-interaction potential leads to a self-consistent calculation performed on a computer. This calculation gives a metal - nonmetal transition similar to the MOTT transition. We consider the effects of temperature and density variations upon this transition. It is possible to make use of this electronic structure to obtain the thermodynamic properties near the transition: pressure, free energy, sound velocity. The numerical results of this simple model are satisfactory. Particularly, if a dielectric constant is taken into account, the transition temperature and density are of the same order of magnitude as those observed experimentally in semiconductors. (author) [fr
Static and thermodynamic properties of liquid and amorphous Fe(2)O(3) nanoparticles.
Hoang, Vo Van; Khanh, B T H L
2009-02-18
Molecular dynamics (MD) simulation of the structure and thermodynamic properties of liquid and amorphous Fe(2)O(3) nanoparticles, with different sizes ranging from 2 to 5 nm, has been carried out based on the Born-Mayer pair potentials under non-periodic boundary conditions. The partial radial distribution functions (PRDFs), coordination number distributions, bond-angle distributions and interatomic distances of liquid nanoparticles at 3500 K were calculated in detail. In addition, we show the radial density profile and stoichiometry in nanoparticles. The temperature dependence of the surface structure and surface energy of nanoparticles has been obtained and presented. Moreover, the size dependence of the glass transition temperature has been found and discussed.
Ternary Bi-Cu-Ni alloys – thermodynamics, characterization, mechanical and electrical properties
Directory of Open Access Journals (Sweden)
Branislav Radomir Marković
2017-09-01
Full Text Available The Bi–Cu–Ni ternary system belongs to the group of potential Cu-Ni-based advanced lead-free solder materials for high temperature application. The paper shows results of the thermodynamic calculations using general solution model along the line with the molar ratio of Cu: Ni = 1:1. The experimental part shows thermal, structural, electrical and mechanical properties based on differential scanning calorimetry (DSC, scanning electron microscopy with energy dispersive spectrometry (SEM-EDS, electroconductivity and hardness measurements of the alloys selected in the section from bismuth corner with molar ratio Cu: Ni = 1:1, Cu: Ni = 3:1, and Cu: Ni = 1:3.
Spinozzi, Francesco; Ceccone, Giacomo; Moretti, Paolo; Campanella, Gabriele; Ferrero, Claudio; Combet, Sophie; Ojea-Jimenez, Isaac; Ghigna, Paolo
2017-03-07
We propose a novel method for determining the structural and thermodynamic properties of nanoparticle-protein complexes under physiological conditions. The method consists of collecting a full set of small-angle X-ray and neutron-scattering measurements in solutions with different concentrations of nanoparticles and protein. The nanoparticle-protein dissociation process is described in the framework of the Hill cooperative model, based on which the whole set of X-ray and neutron-scattering data is fitted simultaneously. This method is applied to water solutions of gold nanoparticles in the presence of human serum albumin without any previous manipulation and can be, in principle, extended to all systems. We demonstrate that the protein dissociation constant, the Hill coefficient, and the stoichiometry of the nanoparticle-protein complex are obtained with a high degree of confidence.
Thermodynamic properties of isomeric iso-butoxybenzoic acids: Experimental and theoretical study
Energy Technology Data Exchange (ETDEWEB)
Jakubczyk, Michał; Sporzyński, Andrzej [Faculty of Chemistry, Warsaw University of Technology, 00-664 Warszawa (Poland); Emel’yanenko, Vladimir N.; Varfolomeev, Mikhail A. [Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Department of Physical Chemistry and Department, Science and Technology of Life, Light and Matter, University of Rostock, D-18059 Rostock (Germany)
2015-09-10
Highlights: • Vapor pressures of butoxy benzoic acid derivatives were measured. • Vaporization, sublimation and fusion enthalpies were derived. • Molar enthalpies of formation were measured by calorimetry. • Thermochemical data tested for consistency using additivity rules and computations. • Simple additivity method suggested for prediction thermochemical properties. - Abstract: Standard (p° = 0.1 MPa) molar enthalpies of formation at the temperature T = 298.15 K of the 2-, 3-, and 4-iso-butoxybenzoic acids were measured using the combustion calorimetry. Standard molar enthalpies of vaporization and sublimation were derived from the vapor pressure temperature dependencies measured by the transpiration method. Molar enthalpies of the solid state phase transitions were measured by the DSC. Thermodynamic data on alkoxy substituted benzoic acids available in the literature were collected and combined with own experimental results. This data set on alkoxybenzoic acids was evaluated by using quantum-chemical and group-additivity methods.
Thermodynamic and transport properties of plasmas including silicon-based compounds
Colonna, G.; D’Angola, A.; Pietanza, L. D.; Capitelli, M.; Pirani, F.; Stevanato, E.; Laricchiuta, A.
2018-01-01
The characterization of the thermodynamic and transport properties of plasmas including silicon species could be of great interest for the investigation of many different systems containing the product of the ablation of silicon-based materials. Different plasma systems (pure silicon, silicon–argon, silicon dioxide and silicon carbide) have been investigated in a wide temperature range (103–4 104 K) and for different pressures (1, 10, 30 and 100 atm), relying on the construction of accurate and extended databases of internal energy levels and binary-interaction transport cross sections for the silicon compounds. The results have been compared with the available results in the literature also studying the dependence on the ratio of components.
Klich, G. F.
1976-01-01
Results of calculations to determine thermodynamic, transport, and flow properties of combustion product gases are presented. The product gases are those resulting from combustion of methane-air-oxygen and methane-oxygen mixtures. The oxygen content of products resulting from the combustion of methane-air-oxygen mixtures was similiar to that of air; however, the oxygen contained in products of methane-oxygen combustion ranged from 20 percent by volume to zero for stoichiometric combustion. Calculations were made for products of reactant mixtures with fuel percentages, by mass, of 7.5 to 20. Results are presented for specific mixtures for a range of pressures varying from 0.0001 to 1,000 atm and for temperatures ranging from 200 to 3,800 K.
Thermodynamic properties of the liquid Bi-Cu-Sn lead-free solder alloys
Directory of Open Access Journals (Sweden)
Kopyto M.
2009-01-01
Full Text Available The electromotive force measurement method was employed to determine the thermodynamic properties of liquid Bi-Cu-Sn alloys using solid electrolyte galvanic cells as shown below: Kanthal+Re, Bi-Cu-Sn, SnO2 | Yttria Stabilized Zirconia | air, Pt, Po2=0.2:1 atm Measurements were carried out for three cross-sections with constant Bi/Cu ratio equal to: 1/3, 1 and 3 and for various tin content varying every 10%, resulting in a total of 26 different alloy compositions. The temperature of the measurements varied within the range from 973 to 1325 K. A linear dependence of the e.m.f. on temperature was observed for all alloy compositions and the appropriate line equations were derived. Tin activities were calculated as function of composition and temperature. Results were presented in tables and figures.
Directory of Open Access Journals (Sweden)
A. Zuber
2015-09-01
Full Text Available AbstractThe correlation of thermodynamic properties of nonaqueous electrolyte solutions is relevant to design and operation of many chemical processes, as in fertilizer production and the pharmaceutical industry. In this work, the Q-electrolattice equation of state (EOS is used to model vapor pressure, mean ionic activity coefficient, osmotic coefficient, and liquid density of sixteen methanol and ten ethanol solutions containing single strong 1:1 and 2:1 salts. The Q-electrolattice comprises the lattice-based Mattedi-Tavares-Castier (MTC EOS, the Born term and the explicit MSA term. The model requires two adjustable parameters per ion, namely the ionic diameter and the solvent-ion interaction energy. Predictions of osmotic coefficient at 298.15 K and liquid density at different temperatures are also presented.
Size and interface effects on several kinetic and thermodynamic properties of polymer thin films
Energy Technology Data Exchange (ETDEWEB)
Lang, X.Y. [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, and Department of Materials Science and Engineering, Jilin University, Changchun 130025 (China); Zhu, Y.F. [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, and Department of Materials Science and Engineering, Jilin University, Changchun 130025 (China); Jiang, Q. [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, and Department of Materials Science and Engineering, Jilin University, Changchun 130025 (China)]. E-mail: jiangq@jlu.edu.cn
2006-12-05
Size and interface effects on kinetic and thermodynamic properties (shear viscosity [{eta}(T,D)], surface tension [{gamma}(T,D)] and thermal expansion coefficient [{beta}(T,D)]) of thin polymer films at temperature T have been modeled based on free volume model and size-dependent function for mean-square displacement of molecules in thin polymer films at glass transition temperature {sigma} {sub g} {sup 2}(D), where D denotes the thickness of thin films. In terms of these models, {eta}(T,D), {beta}(T,D) and {gamma}(T,D) functions are predicted to decrease or increase as D decreases in comparison with the corresponding bulk values, depending on free surface effect and film/substrate interface interaction strength. The predictions are in agreement with available experimental measurements of polystyrene and polybutadiene thin films.
Equation of state for thermodynamic properties of pure and mixtures liquid alkali metals
International Nuclear Information System (INIS)
Mousazadeh, M.H.; Faramarzi, E.; Maleki, Z.
2010-01-01
We developed an equation of state based on statistical-mechanical perturbation theory for pure and mixtures alkali metals. Thermodynamic properties were calculated by the equation of state, based on the perturbed-chain statistical associating fluid theory (PC-SAFT). The model uses two parameters for a monatomic system, segment size, σ, and segment energy, ε. In this work, we calculate the saturation and compressed liquid density, heat capacity at constant pressure and constant volume, isobaric expansion coefficient, for which accurate experimental data exist in the literatures. Results on the density of binary and ternary alkali metal alloys of Cs-K, Na-K, Na-K-Cs, at temperatures from the freezing point up to several hundred degrees above the boiling point are presented. The calculated results are in good agreement with experimental data.
Energy Technology Data Exchange (ETDEWEB)
Kabadi, V.N.
1995-06-30
The work on this project was initiated on September 1, 1991. The project consisted of two different tasks: (1) Development of a model to compute viscosities of coal derived liquids, and (2) Investigate new models for estimation of thermodynamic properties of solid and liquid compounds of the type that exist in coal, or are encountered during coal processing. As for task 1, a model for viscosity computation of coal model compound liquids and coal derived liquids has been developed. The detailed model is presented in this report. Two papers, the first describing the pure liquid model and the second one discussing the application to coal derived liquids, are expected to be published in Energy & Fuels shortly. Marginal progress is reported on task 2. Literature review for this work included compilation of a number of data sets, critical investigation of data measurement techniques available in the literature, investigation of models for liquid and solid phase thermodynamic computations. During the preliminary stages it was discovered that for development of a liquid or solid state equation of state, accurate predictive models for a number of saturation properties, such as, liquid and solid vapor pressures, saturated liquid and solid volumes, heat capacities of liquids and solids at saturation, etc. Most the remaining time on this task was spent in developing predictive correlations for vapor pressures and saturated liquid volumes of organic liquids in general and coal model liquids in particular. All these developments are discussed in this report. Some recommendations for future direction of research in this area are also listed.
International Nuclear Information System (INIS)
Soezen, Adnan; Arcaklioglu, Erol; Oezalp, Mehmet
2005-01-01
This paper presents a new approach based on artificial neural networks (ANNs) to determine the properties of liquid and two phase boiling and condensing of two alternative refrigerant/absorbent couples (methanol/LiBr and methanol/LiCl). These couples do not cause ozone depletion and use in the absorption thermal systems (ATSs). ANNs are able to learn the key information patterns within multidimensional information domain. ANNs operate such as a 'black box' model, requiring no detailed information about the system. On the other hand, they learn the relationship between the input and the output. In order to train the neural network, limited experimental measurements were used as training data and test data. In this study, in input layer, there are temperatures in the range of 298-498 K, pressures (0.1-40 MPa) and concentrations of 2%, 7%, 12% of the couples; specific volume is in output layer. The back-propagation learning algorithm with three different variants, namely scaled conjugate gradient (SCG), Pola-Ribiere conjugate gradient (CGP), and Levenberg-Marquardt (LM), and logistic sigmoid transfer function were used in the network so that the best approach can find. The most suitable algorithm and neuron number in the hidden layer are found as SCG with 8 neurons. For this number level, after the training, it is found that maximum error is less than 3%, average error is about 1% and R 2 value are 99.999%. As seen from the results obtained the thermodynamic equations for each pair by using the weights of network have been obviously predicted within acceptable errors. This paper shows that values predicted with ANN can be used to define the thermodynamic properties instead of approximate and complex analytic equations
Experimental approaches to membrane thermodynamics
DEFF Research Database (Denmark)
Westh, Peter
2009-01-01
Thermodynamics describes a system on the macroscopic scale, yet it is becoming an important tool for the elucidation of many specific molecular aspects of membrane properties. In this note we discuss this application of thermodynamics, and give a number of examples on how thermodynamic measuremen...... have contributed to the understanding of specific membrane phenomena. We mainly focus on non-specific interactions of bilayers and small molecules (water and solutes) in the surrounding solvent, and the changes in membrane properties they bring about. Differences between thermodynamic...... and stoichiometric (structural) definitions of non-specific binding or partitioning are emphasized, and it is concluded that this distinction is important for weak, but not for strong, interactions....
International Nuclear Information System (INIS)
Ackermann, R.J.; Chandrasekharaiah, M.S.
1975-01-01
The thermodynamic data for the actinide metals and oxides (thorium to curium ) have been assessed, examined for consistency, and compared with the lanthanides. Correlations relating the enthalpies of formation of the solid oxides with the corresponding aquo ions make possible the estimation of the thermodynamic properties of AmO 2 (s) and Am 2 O 3 (s) which are in accordance with vaporization data. The known thermodynamic properties of the substoichiometric dioxides MOsub(2-x)(s) at high temperatures demonstrate the relative stabilities of valence states less than 4+ and lead to the examination of stability requirements for the sesquioxides M 2 O 3 (s) and the monoxides MO(s). Sequential trends in the gaseous metals, monoxides and dioxides are examined, compared, and contrasted with the lanthanides. (author)
Mamatkulov, Shavkat; Schwierz, Nadine
2018-02-01
Metal cations are essential in many vital processes. In order to capture the role of different cations in all-atom molecular dynamics simulations of biological processes, an accurate parametrization is crucial. Here, we develop force field parameters for the metal cations Li+, Na+, K+, Cs+, Mg2+, Ca2+, Sr2+, and Ba2+ in combination with the TIP3P water model that is frequently used in biomolecular simulations. In progressing toward improved force fields, the approach presented here is an extension of previous efforts and allows us to simultaneously reproduce thermodynamic and kinetic properties of aqueous solutions. We systematically derive the parameters of the 12-6 Lennard-Jones potential which accurately reproduces the experimental solvation free energy, the activity derivative, and the characteristics of water exchange from the first hydration shell of the metal cations. In order to reproduce all experimental properties, a modification of the Lorentz-Berthelot combination rule is required for Mg2+. Using a balanced set of solution properties, the optimized force field parameters aim to capture the fine differences between distinct metal cations including specific ion binding affinities and the kinetics of cation binding to biologically important anionic groups.
Directory of Open Access Journals (Sweden)
Nilgün Şen
2016-10-01
Full Text Available The B3LYP/6-311++G(2df,2p density functional theory (DFT method was used to investigate molecular geometry and thermodynamic properties of RDX and RDX derivatives containing Al and B metals. The detonation velocity (D and detonation pressure (P, estimated by using Kamlet–Jacobs and in literature equations, respectively. Total energies (Et, frontier orbital energy (EHOMO, ELOMO, energy gap (ΔELUMO–HOMO and theoretical molecular density (ρ were calculated with Spartan 14 software package program. It was shown that the presence of aluminum and boron atoms affects the good thermal stabilities. The results show that the composite RDX-Al, RDX-B derivatives have higher detonation performance and higher density than RDX. RDX-Al derivatives appeared to be superior to RDX-B mixtures in terms of these parameters. These results provide information on the moleculer design of new energetic materials.
Directory of Open Access Journals (Sweden)
Samah Al-Qaisi
Full Text Available First-principles investigations of the Terbium oxide TbO are performed on structural, elastic, mechanical and thermodynamic properties. The investigations are accomplished by employing full potential augmented plane wave FP-LAPW method framed within density functional theory DFT as implemented in the WIEN2k package. The exchange-correlation energy functional, a part of the total energy functional, is treated through Perdew Burke Ernzerhof scheme of the Generalized Gradient Approximation PBEGGA. The calculations of the ground state structural parameters, like lattice constants a0, bulk moduli B and their pressure derivative Bâ² values, are done for the rock-salt RS, zinc-blende ZB, cesium chloride CsCl, wurtzite WZ and nickel arsenide NiAs polymorphs of the TbO compound. The elastic constants (C11, C12, C13, C33, and C44 and mechanical properties (Youngâs modulus Y, Shear modulus S, Poissonâs ratio Ï, Anisotropic ratio A and compressibility Î², were also calculated to comprehend its potential for valuable applications. From our calculations, the RS phase of TbO compound was found strongest one mechanically amongst the studied cubic structures whereas from hexagonal phases, the NiAs type structure was found stronger than WZ phase of the TbO. To analyze the ductility of the different structures of the TbO, Pughâs rule (B/SH and Cauchy pressure (C12âC44 approaches are used. It was found that ZB, CsCl and WZ type structures of the TbO were of ductile nature with the obvious dominance of the ionic bonding while RS and NiAs structures exhibited brittle nature with the covalent bonding dominance. Moreover, Debye temperature was calculated for both cubic and hexagonal structures of TbO in question by averaging the computed sound velocities. Keywords: DFT, TbO, Elastic properties, Thermodynamic properties
ShunLi Shang; Louis G. Hector Jr.; Paul Saxe; Zi-Kui Liu; Robert J. Moon; Pablo D. Zavattieri
2014-01-01
Anisotropy and temperature dependence of structural, thermodynamic and elastic properties of crystalline cellulose Iβ were computed with first-principles density functional theory (DFT) and a semi-empirical correction for van der Waals interactions. Specifically, we report the computed temperature variation (up to 500...
An introduction to equilibrium thermodynamics
Morrill, Bernard; Hartnett, James P; Hughes, William F
1973-01-01
An Introduction to Equilibrium Thermodynamics discusses classical thermodynamics and irreversible thermodynamics. It introduces the laws of thermodynamics and the connection between statistical concepts and observable macroscopic properties of a thermodynamic system. Chapter 1 discusses the first law of thermodynamics while Chapters 2 through 4 deal with statistical concepts. The succeeding chapters describe the link between entropy and the reversible heat process concept of entropy; the second law of thermodynamics; Legendre transformations and Jacobian algebra. Finally, Chapter 10 provides a
Mechanical, dynamical and thermodynamic properties of Al-3wt%Mg from first principles
Energy Technology Data Exchange (ETDEWEB)
Yang, Rong [Chongqing Jiaotong Univ., Chongqing (China). College of Materials Science and Engineering; Tang, Bin [Chongqing City Management College, Chongqing (China). Inst. of Finance and Trade; Gao, Tao [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics
2017-09-01
The mechanical, dynamical and thermodynamic properties of Al-3wt%Mg have been investigated using the first-principles method. The calculated structural parameter is in good agreement with previous works. Results for the elastic modulus, stress-strain relationships, ideal tensile and shear strengths are presented. Al-3wt%Mg is found to have larger moduli and higher strengths than Al, which is consistent with its exploitation in Al precipitate-hardening mechanisms. The partial density of states (PDOS) show that the partly covalent-like bonding through Al p-Mg s hybridization is the origin of excellent mechanical properties of Al-3wt%Mg. The phonon dispersion curves indicate that Al-3wt%Mg is dynamically stable at ambient pressure and 0 K. Furthermore, the Helmholtz free energy ΔF, the entropy S, the constant-volume specific heat C{sub V} and the phonon contribution to the internal energy ΔE are predicted using the phonon density of states. We expect that our work can provide useful guidance to help with the performance of Al-3wt%Mg.
Influence of volume magnetostriction on the thermodynamic properties of Ni-Mn-Ga shape memory alloys
Energy Technology Data Exchange (ETDEWEB)
Kosogor, Anna [National University of Science and Technology “MISiS,” Moscow 119049 (Russian Federation); Institute of Magnetism, 36-b, Vernadsky Str., Kyiv 03142 (Ukraine); Donetsk Institute for Physics and Engineering, Kyiv 03028 (Ukraine); L' vov, Victor A. [Institute of Magnetism, 36-b, Vernadsky Str., Kyiv 03142 (Ukraine); Faculty of Radiophysics, Electronics and Computer Systems, Taras Shevchenko University, Glushkov Str. 4G, Kyiv 01601 (Ukraine); Departament de Fisica, Universitat de les Illes Balears, Ctra. de Valldemossa, km 7.5, 07122 Palma de Mallorca (Spain); Cesari, Eduard [Departament de Fisica, Universitat de les Illes Balears, Ctra. de Valldemossa, km 7.5, 07122 Palma de Mallorca (Spain)
2015-10-07
In the present article, the thermodynamic properties of Ni-Mn-Ga ferromagnetic shape memory alloys exhibiting the martensitic transformations (MTs) above and below Curie temperature are compared. It is shown that when MT goes below Curie temperature, the elastic and thermal properties of alloy noticeably depend on magnetization value due to spontaneous volume magnetostriction. However, the separation of magnetic parts from the basic characteristics of MT is a difficult task, because the volume magnetostriction does not qualitatively change the transformational behaviour of alloy. This problem is solved for several Ni-Mn-Ga alloys by means of the quantitative theoretical analysis of experimental data obtained in the course of stress-strain tests. For each alloy, the entropy change and the transformation heat evolved in the course of MT are evaluated, first, from the results of stress-strain tests and, second, from differential scanning calorimetry data. For all alloys, a quantitative agreement between the values obtained in two different ways is observed. It is shown that the magnetic part of transformation heat exceeds the non-magnetic one for the Ni-Mn-Ga alloys undergoing MTs in ferromagnetic state, while the elevated values of transformation heat measured for the alloys undergoing MTs in paramagnetic state are caused by large MT strains.
Mechanical, dynamical and thermodynamic properties of Al-3wt%Mg from first principles
International Nuclear Information System (INIS)
Yang, Rong; Tang, Bin; Gao, Tao
2017-01-01
The mechanical, dynamical and thermodynamic properties of Al-3wt%Mg have been investigated using the first-principles method. The calculated structural parameter is in good agreement with previous works. Results for the elastic modulus, stress-strain relationships, ideal tensile and shear strengths are presented. Al-3wt%Mg is found to have larger moduli and higher strengths than Al, which is consistent with its exploitation in Al precipitate-hardening mechanisms. The partial density of states (PDOS) show that the partly covalent-like bonding through Al p-Mg s hybridization is the origin of excellent mechanical properties of Al-3wt%Mg. The phonon dispersion curves indicate that Al-3wt%Mg is dynamically stable at ambient pressure and 0 K. Furthermore, the Helmholtz free energy ΔF, the entropy S, the constant-volume specific heat C V and the phonon contribution to the internal energy ΔE are predicted using the phonon density of states. We expect that our work can provide useful guidance to help with the performance of Al-3wt%Mg.
Thermodynamic Properties of Compressed CuX (X = Cl, Br) Compounds: Ab Initio Study
Bioud, Nadhira; Kassali, Kamel; Bouarissa, Nadir
2017-04-01
A pseudopotential plane wave method based on the density functional theory has been employed to study some thermodynamic properties of copper chloride (CuCl) and copper bromide (CuBr) compounds under the effect of temperature and pressure. The phase transition pressure, the unit cell volume, the isothermal bulk modulus, the constant volume heat capacity, the entropy, the Debye temperature, the Grüneisen parameter and the volumetric thermal expansion coefficient are studied in the pressure range 0-10 GPa, and for temperatures ranging from 0 K up to 650 K and 750 K for CuCl and CuBr, respectively. The phase transition pressure is found to be around 7.8 and 6.95 GPa for CuCI and CuBr, respectively. These values are respectively in reasonably good agreement with the experimental ones of 8.2 GPa and 6.8 GPa reported in the literature. Moreover, at room temperature and zero pressure, the heat capacity at constant volume and the Grüneisen parameter of both compounds of interest are found to be in good agreement with the available experimental and theoretical data. The information gathered from the present investigation may be useful for the study of the behavior of the fundamental properties of CuCI and CuBr under the influence of high temperature and pressure.
Directory of Open Access Journals (Sweden)
Troter Dragan Z.
2017-01-01
Full Text Available This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity properties of several choline chloride (ChCl based deep eutectic solvents (DESs, with 1:2 mole ratio, respectively: ChCl:propylene glycol, ChCl:1,3-dimethylurea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15–363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio. Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel–Tamman–Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity of ChCl:1,3-dimethylurea and ChCl: :thiourea DESs were inferior to those of the ChCl:urea DES. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 45001
International Nuclear Information System (INIS)
Ionova, Galina V
2002-01-01
Experimental and theoretical data on the structures and properties of compounds of tetravalent transactinides (TAn IV ) Rf (Z = 104), Db (Z = 105), Sg (Z = 106), Bh (Z = 107), Hs (Z = 108), Mt (Z = 109), and 110 TAn (Z = 110) are described systematically. The problem of disposition of the transactinide elements in the Periodic system is discussed and the properties of the 6d-, 5d-, 4d-, 3d- and 5f-elements are compared. Regularities of changes in the thermodynamic characteristics of TAn IV compounds versus the atomic number, Z(TAn), are elucidated. Peculiarities of changes in thermodynamic properties upon the formation of nitrate, fluoride and chloride TAn IV complexes in solution are discussed. The bibliography includes 140 references.
Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao
2015-10-19
The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics.
Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao
2015-01-01
The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics. PMID:26478214
Assessment of the thermodynamic properties and phase diagram of the Bi–Pd system
Czech Academy of Sciences Publication Activity Database
Vřešťál, J.; Pinkas, J.; Watson, A.; Scott, A.; Houserová, Jana; Kroupa, Aleš
2006-01-01
Roč. 30, č. 1 (2006), s. 14-17 ISSN 0364-5916 R&D Projects: GA MŠk(CZ) OC 531.002 Institutional research plan: CEZ:AV0Z2041904 Keywords : phase diagram * thermodynamic modelling Subject RIV: BJ - Thermodynamics Impact factor: 1.432, year: 2006
Properties Important To Mixing For WTP Large Scale Integrated Testing
International Nuclear Information System (INIS)
Koopman, D.; Martino, C.; Poirier, M.
2012-01-01
Large Scale Integrated Testing (LSIT) is being planned by Bechtel National, Inc. to address uncertainties in the full scale mixing performance of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. External review boards have raised questions regarding the overall representativeness of simulants used in previous mixing tests. Accordingly, WTP requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in LSIT. Among the first tasks assigned to SRNL was to develop a list of waste properties that matter to pulse-jet mixer (PJM) mixing of WTP tanks. This report satisfies Commitment 5.2.3.1 of the Department of Energy Implementation Plan for Defense Nuclear Facilities Safety Board Recommendation 2010-2: physical properties important to mixing and scaling. In support of waste simulant development, the following two objectives are the focus of this report: (1) Assess physical and chemical properties important to the testing and development of mixing scaling relationships; (2) Identify the governing properties and associated ranges for LSIT to achieve the Newtonian and non-Newtonian test objectives. This includes the properties to support testing of sampling and heel management systems. The test objectives for LSIT relate to transfer and pump out of solid particles, prototypic integrated operations, sparger operation, PJM controllability, vessel level/density measurement accuracy, sampling, heel management, PJM restart, design and safety margin, Computational Fluid Dynamics (CFD) Verification and Validation (V and V) and comparison, performance testing and scaling, and high temperature operation. The slurry properties that are most important to Performance Testing and Scaling depend on the test objective and rheological classification of the slurry (i
International Nuclear Information System (INIS)
Durán-Zenteno, Moisés S.; Pérez-López, Hugo I.; Galicia-Luna, Luis A.; Elizalde-Solis, Octavio
2012-01-01
Highlights: ► We measured densities for {alkanol (ethanol or 1-propanol) + boldine} mixtures. ► Liquid densities are reported in the ranges of (1 to 20) MPa and (313 to 363) K. ► Thermodynamic derived properties were calculated using an empirical correlation. ► Extrapolated densities at atmospheric pressure agree with the literature data. - Abstract: In this work, densities of two binary systems of {alkanol (ethanol and 1-propanol) + boldine} are measured at temperatures from (313 to 363) K and pressures up to 20 MPa using an Anton Paar vibrating tube densimeter. Each (alkanol + boldine) system was prepared at five diluted compositions with respect to the alkaloid. These are (x 2 = 0.0012, 0.0074, 0.0136, 0.0196, 0.0267) and (x 2 = 0.0018, 0.0046, 0.0077, 0.0112, 0.0142) mixed in ethanol and 1-propanol, respectively. Experimental densities are correlated using an empirical 6-parameter equation with deviations within 0.04%. Extrapolated densities at atmospheric pressure agree with the literature data. Isobaric expansivity, isothermal compressibility, thermal pressure coefficient, and internal pressure have been calculated.
Thermodynamics Properties of Binary Gas Mixtures for Brayton Space Nuclear Power System
International Nuclear Information System (INIS)
You Ersheng; Shi Lei; Zhang Zuoyi
2014-01-01
Space nuclear power system with closed Brayton cycle has the potential advantages of high cycle efficiency. It can be achieved to limit the specific mass of the system with a competitive design scheme, so as to strengthen the advantage of the nuclear energy applying in space propulsion and electric generating compared to solar or chemical propellant. Whereby, the thermodynamic properties of working fluids have a significant influence on the performance of the plant. Therefore, two binary mixtures helium-nitrogen and helium-carbon dioxide are introduced to analysis the variation in the transport and heat transfer capacity of working fluids. Based on the parameters of pure gases, the heat transfer coefficient, pressure losses and aerodynamic loading are calculated as a function of mole fraction at the temperature of 400 K and 1200 K, as well as the typical operating pressure of 2 MPa. Results indicated that the mixture of helium-carbon dioxide with a mole fraction of 0.4 is a more attractive choice for the high heat transfer coefficient, low aerodynamic loading and acceptable pressure losses in contrast to helium-nitrogen and other mixing ratios of helium-carbon dioxide. Its heat transfer coefficient is almost 20% more than that of pure helium and the normalized aerodynamic loading is less than 34% at 1200 K. However; the pressure losses are a little higher with ~3.5 times those of pure helium. (author)
Thermodynamic Properties of a Double Ring-Shaped Quantum Dot at Low and High Temperatures
Khordad, R.; Sedehi, H. R. Rastegar
2018-02-01
In this work, we study thermodynamic properties of a GaAs double ring-shaped quantum dot under external magnetic and electric fields. To this end, we first solve the Schrödinger equation and obtain the energy levels and wave functions, analytically. Then, we calculate the entropy, heat capacity, average energy and magnetic susceptibility of the quantum dot in the presence of a magnetic field using the canonical ensemble approach. According to the results, it is found that the entropy is an increasing function of temperature. At low temperatures, the entropy increases monotonically with raising the temperature for all values of the magnetic fields and it is independent of the magnetic field. But, the entropy depends on the magnetic field at high temperatures. The entropy also decreases with increasing the magnetic field. The heat capacity and magnetic susceptibility show a peak structure. The heat capacity reduces with increasing the magnetic field at low temperatures. The magnetic susceptibility shows a transition between diamagnetic and paramagnetic below for T<4 K. The transition temperature depends on the magnetic field.
Kinetic and thermodynamic properties of soybean grains during the drying process
Directory of Open Access Journals (Sweden)
Daniel Emanuel Cabral de Oliveira
2013-09-01
Full Text Available The aims of this work were to adjust different mathematical models to experimental data describing the drying of the Valiosa cultivar soybean grain, to determine and to evaluate the effective diffusion coefficient and to obtain the activation energy and the thermodynamic properties of the drying process under different air conditions. The experiments were conducted at the Federal Institute of Education, Science and Technology of Goiás (Instituto Federal de Educação, Ciência e Tecnologia Goiano – Câmpus Rio Verde. The Valiosa cultivar soybean grains, with an initial moisture content on a dry basis of 0.56 (d.b., decimal, were dried in an oven with forced air ventilation at five different temperatures (40, 55, 70, 85 and 100°C until reaching a moisture content of 0.133±0.019 (d.b.. Of the models analyzed, Page’s model was selected to best represent the drying phenomenon. The effective diffusion coefficient of soybeans increased with the air temperature and was described by the Arrhenius equation; an activation energy of 22.77 kJ mol–1 was reported for liquid diffusion in the drying of the soybeans. The enthalpy and entropy decreased with increasing temperature, while the Gibbs free energy increased with increasing drying temperature.
Temperature dependence of thermodynamic properties of spinel CuIr2S4
Ito, Masakazu; Sonoda, Kazuki; Nagata, Shoichi
2017-10-01
We have investigated the thermodynamic and electrical properties of spinel CuIr2S4. The temperature, T, dependence of the electrical resistivity ρ (T) , thermal conductivity, κ (T) , and thermoelectric power, S(T), show the abrupt jumps with the relative large hysteresis at a metal-insulator transition temperature TMI ∼ 230 K , with decreasing T. The acoustic-Debye model can fit κ (T) in the insulating phase (T
Measurement and modelling of high temperature thermodynamic properties of URh3 alloy
International Nuclear Information System (INIS)
Rai, Arun Kumar; Tripathy, Haraprasanna; Jeya Ganesh, B.; Raju, S.
2012-01-01
The high temperature phase stability of arc-melted cubic URh 3 intermetallic compound has been investigated using high temperature inverse drop calorimetry in the temperature range of 300–1273 K. URh 3 exists as a line compound with negligible solubility range. Room temperature XRD profile and elemental X-ray mapping experiments on 1273 K/3 h homogenized samples have confirmed the homogeneity and L1 2 (cF8; pm3m) crystal structure of URh 3 . The drop measurements yielded accurate values for the enthalpy increment ΔH T 0 as a function of temperature, from which the specific heat C P has been estimated. The enthalpy data obtained in this study have been compared and combined with the reported data on low temperature C P and also with the ΔH T 0 in the temperature range, 0–840 K, for a comprehensive theoretical analysis using quasiharmonic Debye–Grüneisen formalism. It is found that this model with due allowance for thermal expansion effects can successfully account for the experimentally measured thermal property data in the entire temperature region spanning 0–1273 K. Invoking a combination of measurement and modelling, a comprehensive set of thermodynamic quantities have been obtained for URh 3 .
International Nuclear Information System (INIS)
Fang Zheng; Zhang Quanru
2006-01-01
A model has been derived to predict thermodynamic properties of ternary metallic systems from those of its three binaries. In the model, the excess Gibbs free energies and the interaction parameter ω 123 for three components of a ternary are expressed as a simple sum of those of the three sub-binaries, and the mole fractions of the components of the ternary are identical with the sub-binaries. This model is greatly simplified compared with the current symmetrical and asymmetrical models. It is able to overcome some shortcomings of the current models, such as the arrangement of the components in the Gibbs triangle, the conversion of mole fractions between ternary and corresponding binaries, and some necessary processes for optimizing the various parameters of these models. Two ternary systems, Mg-Cu-Ni and Cd-Bi-Pb are recalculated to demonstrate the validity and precision of the present model. The calculated results on the Mg-Cu-Ni system are better than those in the literature. New parameters in the Margules equations expressing the excess Gibbs free energies of three binary systems of the Cd-Bi-Pb ternary system are also given
International Nuclear Information System (INIS)
Dubey, Gyan Prakash; Kumar, Krishan
2011-01-01
Highlights: → Thermodynamic study of diethylenetriamine + 2-methyl-1-propanol, +2-propanol or +1-butanol have been made. → Excess molar volumes and isentropic compressibility were determined. → Types of interactions were discussed based on derived properties. - Abstract: Densities, ρ, viscosities, η, and speeds of sound, u, were measured for the binary liquid mixtures containing diethylenetriamine with 2-methyl-1-propanol, 2-propanol and 1-butanol at 293.15, 298.15, 303.15, 308.15 and 313.15 K. From density and speed of sound data, excess molar volumes, V m E and deviations in isentropic compressibility, Δκ s , and speed of sound, Δu have been evaluated. Viscosity data were used to compute deviations in viscosity and excess Gibbs energy of activation of viscous flow ΔG* E at 298.15, 303.15 and 308.15 K. A Redlich-Kister type equation was applied to fit the excess molar volumes and deviations in isentropic compressibility, speed of sound and viscosity data. The viscosity data have been correlated with the equations of Grunberg-Nissan, Tamura-Kurata, Heric-Brewer and of Hind et al. All the binary systems of the present study have negative values of excess molar volumes and deviations in isentropic compressibility over whole composition range and at all temperatures which indicates strong interactions between the components of binary mixtures.
Thermodynamic Properties of He Gas in the Temperature Range 4.2-10 K
Mosameh, S. M.; Sandouqa, A. S.; Ghassib, H. B.; Joudeh, B. R.
2014-05-01
The thermodynamic properties of He gas are investigated in the temperature-range 4.2-10 K, with special emphasis on the second virial coefficient in both the classical and quantum regimes. The main input in computing the quantum coefficient is the `effective' phase shifts. These are calculated within the framework of the Galitskii-Migdal-Feynman (GMF) formalism, using the HFDHE2 and Sposito potentials. The virial equation of state is constructed. Extensive calculations are carried out for the pressure-volume-temperature (P-V-T) behavior, as well as chemical potential, and nonideality of the system. The following results are obtained. First, the validity of the GMF formalism for the present system is demonstrated beyond any doubt. Second, the boiling point (phase-transition point) of He gas is determined from the P-V behavior using the virial equation of state, its value being closest than all previous results to the experimental value. Third, the chemical potential is evaluated from the quantum second virial coefficient. It is found that increases (becomes less negative) as the temperature decreases or the number density n increases. Further, shows no sensitivity to the differences between the potentials used up to n = 10 m. Finally, the compressibility Z is computed and discussed as a measure of the nonideality of the system.
Thermodynamic properties and cloud droplet activation of a series of oxo-acids
Directory of Open Access Journals (Sweden)
M. Frosch
2010-07-01
Full Text Available We have investigated the thermodynamic properties of four aliphatic oxo-dicarboyxlic acids identified or thought to be present in atmospheric particulate matter: oxosuccinic acid, 2-oxoglutaric acid, 3-oxoglutaric acid, and 4-oxopimelic acid. The compounds were characterized in terms of their cloud condensation nuclei (CCN activity, vapor pressure, density, and tendency to decarboxylate in aqueous solution. We deployed a variety of experimental techniques and instruments: a CCN counter, a Tandem Differential Mobililty Analyzer (TDMA coupled with a laminar flow-tube, and liquid chromatography/mass spectrometry (LC/MS. The presence of the oxo functional group in the α-position causes the vapor pressure of the compounds to diminish by an order of magnitude with respect to the parent dicarboxylic acid, while the CCN activity is similar or increased. Dicarboxylic acids with an oxo-group in the β-position decarboxylate in aqueous solution. We studied the effects of this process on our measurements and findings.
Magnetic and thermodynamic properties of face-centered cubic Fe-Ni alloys.
Lavrentiev, M Yu; Wróbel, J S; Nguyen-Manh, D; Dudarev, S L
2014-08-14
A model lattice ab initio parameterized Heisenberg-Landau magnetic cluster expansion Hamiltonian spanning a broad range of alloy compositions and a large variety of chemical and magnetic configurations has been developed for face-centered cubic Fe-Ni alloys. The thermodynamic and magnetic properties of the alloys are explored using configuration and magnetic Monte Carlo simulations over a temperature range extending well over 1000 K. The predicted face-centered cubic-body-centered cubic coexistence curve, the phase stability of ordered Fe3Ni, FeNi, and FeNi3 intermetallic compounds, and the predicted temperatures of magnetic transitions simulated as functions of alloy composition agree well with experimental observations. Simulations show that magnetic interactions stabilize the face-centered cubic phase of Fe-Ni alloys. Both the model Hamiltonian simulations and ab initio data exhibit a particularly large number of magnetic configurations in a relatively narrow range of alloy compositions corresponding to the occurrence of the Invar effect.
International Nuclear Information System (INIS)
Green, C.
1979-12-01
A set of FORTRAN subroutines is described for calculating water thermodynamic properties. These were written for use in a transient thermal-hydraulics program, where speed of execution is paramount. The choice of which subroutines to optimise depends on the primary variables in the thermal-hydraulics code. In this particular case the subroutine which has been optimised is the one which calculates pressure and specific enthalpy given the specific volume and the specific internal energy. Another two subroutines are described which complete a self-consistent set. These calculate the specific volume and the temperature given the pressure and the specific enthalpy, and the specific enthalpy and the specific volume given the pressure and the temperature (or the quality). The accuracy is high near the saturation lines, typically less than 1% relative error, and decreases as the fluid becomes more subcooled in the liquid region or more superheated in the steam region. This behaviour is inherent in the method which uses quantities defined on the saturation lines and assumes that certain derivatives are constant for excursions away from these saturation lines. The accuracy and speed of the subroutines are discussed in detail in this report. (author)
Determination of thermodynamic properties of aluminum based binary and ternary alloys
Energy Technology Data Exchange (ETDEWEB)
Altıntas, Yemliha [Abdullah Gül University, Faculty of Engineering, Department of Materials Science and Nanotechnology, 38039, Kayseri (Turkey); Aksöz, Sezen [Nevşehir Hacı Bektaş Veli University, Faculty of Arts and Science, Department of Physics, 50300, Nevşehir (Turkey); Keşlioğlu, Kâzım, E-mail: kesli@erciyes.edu.tr [Erciyes University, Faculty of Science, Department of Physics, 38039, Kayseri (Turkey); Maraşlı, Necmettin [Yıldız Technical University, Faculty of Chemical and Metallurgical Engineering, Department of Metallurgical and Materials Engineering, 34210, Davutpaşa, İstanbul (Turkey)
2015-11-15
In the present work, the Gibbs–Thomson coefficient, solid–liquid and solid–solid interfacial energies and grain boundary energy of a solid Al solution in the Al–Cu–Si eutectic system were determined from the observed grain boundary groove shapes by measuring the thermal conductivity of the solid and liquid phases and temperature gradient. Some thermodynamic properties such as the enthalpy of fusion, entropy of fusion, the change of specific heat from liquid to solid and the electrical conductivity of solid phases at their melting temperature were also evaluated by using the measured values of relevant data for Al–Cu, Al–Si, Al–Mg, Al–Ni, Al–Ti, Al–Cu–Ag, Al–Cu–Si binary and ternary alloys. - Highlights: • The microstructure of the Al–Cu–Si eutectic alloy was observed through SEM. • The three eutectic phases (α-Al, Si, CuAl{sub 2}) have been determined by EDX analysis. • Solid–liquid and solid–solid interfacial energies of α-Al solution were determined. • ΔS{sub f},ΔH{sub M}, ΔC{sub P}, electrical conductivity of solid phases for solid Al solutions were determined. • G–T coefficient and grain boundary energy of solid Al solution were determined.
Kaya, Ismet; Pala, Cigdem Yigit
2014-07-01
In this work, some thermodynamic properties of poly (cyclohexyl methacrylate) were studied by inverse gas chromatography (IGC). For this purpose, the polymeric substance was coated on Chromosorb W and which was filled into a glass column. The retention times (t(r)) of the probes were determined from the interactions of poly (cyclohexyl methacrylate) with n-pentane, n-hexane, n-heptane, n-octane, n-decane, methanol, ethanol, 2-propanol, butanol, acetone, ethyl methyl ketone, benzene, toluene and o-xylene by IGC technique. Then, the specific volume (Vg(0)) was determined for each probe molecule. By using (1/T; lnVg(0)) graphics, the glass transition temperature of poly (cyclohexyl methacrylate) was found to be 373 K. The adsorption heat under the glass transition temperature (deltaH(a)), and partial molar heat of sorption above the glass transition (deltaH1(S)), partial molar free energy of sorption (deltaG1(S)) and partial molar entropy of sorption (deltaS1(S)) belonging to sorption for every probe were calculated. The partial molar heat of mixing at infinite dilution (deltaH1(infinity)), partial molar free energy of mixing at infinite dilution (deltaG1(infinity)), Flory-Huggins interaction parameter (chi12(infinity)) and weight fraction activity coefficient (a1/w1)(infinity) values of polymer-solute systems were calculated at different column temperatures. The solubility parameters (delta2) of the polymer were obtained by IGC technique.
International Nuclear Information System (INIS)
Drouet, Christophe
2015-01-01
Graphical abstract: Experimental thermodynamic properties of phosphate apatites are reviewed and commented. Predictive methods are developed and tested here for apatite compounds, allowing reliable estimations of ΔH f °, ΔG f ° and S°, not only for end-members but also for solid solutions, non-stoichiometric and hydrated samples. A periodic table of recommended thermodynamic properties for 33 apatite systems is generated, and relative stabilities are pointed out. - Highlights: • Experimental thermodynamic properties of phosphate apatites are reviewed. • Predictive thermodynamic methods are investigated for estimating missing data. • An additive model is developed to estimate ΔH f °, ΔG f ° and S° for phosphate apatites. • End-members, solid solutions, nonstoichiometric and hydrated samples are considered. • A periodic table of recommended thermodynamic properties for 33 systems is proposed. - Abstract: Apatite minerals represent a major class of ionic compounds of interest to many disciplines including medical sciences, geology, anthropology, cosmology, environmental and nuclear sciences. Yet, these compounds have not received great attention from a thermodynamic viewpoint, and some diverging data – often drawn from molecular modeling assays – were reported. In this contribution, an extensive literature overview of available experimental-based data on M 10 (PO 4 ) 6 X 2 apatites with M = Ca, Ba, Sr, Mg, Cd, Pb, Cu, Zn and X = OH, F, Cl or Br has first been made, on the basis of standard formation energetics (ΔH f ° and ΔG f °) as well as entropy S° and molar heat capacity C p,m °. The case of oxyapatite was also included. From this overview, it was then possible to identify general tendencies, evidencing in particular the primary role of electronegativity and secondarily of ionic size. Using the experimental data as reference, several predictive thermodynamic methods were then evaluated, including the volume-based-thermodynamics (VBT
Stolyarova, V L; Shilov, A L; Lopatin, S I; Shugurov, S M
2014-04-15
Binary glass-forming systems containing bismuth(III) oxide, especially the Bi2O3-SiO2 system, are of great importance in modern materials science: preparation of thin films, fiber optics, potential solar converters, and radiation shields in nuclear physics. Information on vaporization processes and thermodynamic properties obtained in the present study and the results of modeling of this system will be useful for optimization of the synthesis and applications of Bi2O3-containing materials at high temperatures. High-temperature Knudsen effusion mass spectrometry was used to study the vaporization processes and to determine the partial pressures of components of the Bi2O3-SiO2 system. Measurements were performed with a MS-1301 mass spectrometer. Vaporization was carried out using two iridium-plated molybdenum effusion cells containing the sample under study and pure bismuth(III) oxide (reference substance). Modeling of the thermodynamic properties and structure of glasses and melts in the Bi2O3-SiO2 and Bi2O3-B2O3 systems was performed using a modified approach based on the generalized lattice theory of associated solutions (GLTAS). At a temperature of 1000 K, Bi and O2 were found to be the main vapor species over the samples studied. The Bi2O3 activity as a function of composition of the Bi2O3-SiO2 system was obtained from the measured partial pressures of the vapor species. The thermodynamic properties of mixing from oxides in this system were calculated. The advantages of GLTAS for modeling of glasses and melts in the binary systems containing Bi2O3 were demonstrated. The thermodynamic functions of mixing in glasses and melts of the Bi2O3-SiO2 system determined at 1000 K in the present study, as well as in the Bi2O3-B2O3 system, demonstrated negative deviations from ideality. Modeling of the obtained experimental data using GLTAS allowed a correlation to be found between the thermodynamic properties and the relative number of bonds of various types formed in
Wu, Yi; Wang, Chunlin; Sun, Hao; Murphy, Anthony B.; Rong, Mingzhe; Yang, Fei; Chen, Zhexin; Niu, Chunpin; Wang, Xiaohua
2018-04-01
The thermophysical properties, including composition, thermodynamic properties, transport coefficients and net emission coefficients, of thermal plasmas formed from pure iso-C4 perfluoronitrile C4F7N and C4F7N–CO2 mixtures are calculated for temperatures from 300 to 30 000 K and pressures from 0.1 to 20 atm. These gases have received much attention as alternatives to SF6 for use in circuit breakers, due to the low global warming potential and good dielectric properties of C4F7N. Since the parameters of the large molecules formed in the dissociation of C4F7N are unavailable, the partition function and enthalpy of formation were calculated using computational chemistry methods. From the equilibrium composition calculations, it was found that when C4F7N is mixed with CO2, CO2 can capture C atoms from C4F7N, producing CO, since the system consisting of small molecules such as CF4 and CO has lower energy at room temperature. This is in agreement with previous experimental results, which show that CO dominates the decomposition products of C4F7N–CO2 mixtures; it could limit the repeated breaking performance of C4F7N. From the point of view of chemical stability, the mixing ratio of CO2 should therefore be chosen carefully. Through comparison with common arc quenching gases (including SF6, CF3I and C5F10O), it is found that for the temperature range for which electrical conductivity remains low, pure C4F7N has similar ρC p (product of mass density and specific heat) properties to SF6, and higher radiative emission coefficient, properties that are correlated with good arc extinguishing capability. For C4F7N–CO2 mixtures, the electrical conductivity is very close to that of SF6 while the ρC p peak at 7000 K caused by decomposition of CO implies inferior interruption capability to that of SF6. The calculated properties will be useful in arc simulations.
Wang, Haiyan; Wang, Weizong; Yan, Joseph D.; Qi, Haiyang; Geng, Jinyue; Wu, Yaowu
2017-10-01
Ablation-controlled plasmas have been used in a range of technical applications where local thermodynamic equilibrium (LTE) is often violated near the wall due to the strong cooling effect caused by the ablation of wall materials. The thermodynamic and transport properties of ablated polytetrafluoroethylene (PTFE) vapor, which determine the flowing plasma behavior in such applications, are calculated based on a two-temperature model at atmospheric pressure. To our knowledge, no data for PTFE have been reported in the literature. The species composition and thermodynamic properties are numerically determined using the two-temperature Saha equation and the Guldberg-Waage equation according to van de Sanden et al’s derivation. The transport coefficients, including viscosity, thermal conductivity and electrical conductivity, are calculated with the most recent collision interaction potentials using Devoto’s electron and heavy-particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) in the frame of the Chapman-Enskog method. Results are computed for different degrees of thermal non-equilibrium, i.e. the ratio of electron to heavy-particle temperatures, from 1 to 10, with electron temperature ranging from 300 to 40 000 K. Plasma transport properties in the LTE state obtained from the present work are compared with existing published results and the causes for the discrepancy analyzed. The two-temperature plasma properties calculated in the present work enable the modeling of wall ablation-controlled plasma processes.
Simulations of the Thermodynamic and Diffusion Properties of Actinide Oxide Fuel Materials
International Nuclear Information System (INIS)
Becker, Udo
2013-01-01
Spent nuclear fuel from commercial reactors is comprised of 95-99 percent UO 2 and 1-5 percent fission products and transuranic elements. Certain actinides and fission products are of particular interest in terms of fuel stability, which affects reprocessing and waste materials. The transuranics found in spent nuclear fuels are Np, Pu, Am, and Cm, some of which have long half- lives (e.g., 2.1 million years for 237 Np). These actinides can be separated and recycled into new fuel matrices, thereby reducing the nuclear waste inventory. Oxides of these actinides are isostructural with UO 2 , and are expected to form solid solutions. This project will use computational techniques to conduct a comprehensive study on thermodynamic properties of actinide-oxide solid solutions. The goals of this project are to: Determine the temperature-dependent mixing properties of actinide-oxide fuels; Validate computational methods by comparing results with experimental results; Expand research scope to complex (ternary and quaternary) mixed actinide oxide fuels. After deriving phase diagrams and the stability of solid solutions as a function of temperature and pressure, the project team will determine whether potential phase separations or ordered phases can actually occur by studying diffusion of cations and the kinetics of potential phase separations or ordered phases. In addition, the team will investigate the diffusion of fission product gases that can also have a significant influence on fuel stability. Once the system has been established for binary solid solutions of Th, U, Np, and Pu oxides, the methodology can be quickly applied to new compositions that apply to ternaries and quaternaries, higher actinides (Am, Cm), burnable poisons (B, Gd, Hf), and fission products (Cs, Sr, Tc) to improve reactivity
Energy Technology Data Exchange (ETDEWEB)
Murtaza, G., E-mail: murtaza@icp.edu.pk [Materials Modeling Laboratory, Department of Physics, Islamia College Peshawar (Pakistan); Gupta, S.K. [Department of Physics, Michigan Technological University, Houghton, MI 49931 (United States); Seddik, T. [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, 29000 Mascara (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, 29000 Mascara (Algeria); Alahmed, Z.A. [Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Ahmed, R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Khachai, H. [Physics Department, Djillali Liabes University of Sidi Bel-Abbes (Algeria); Jha, P.K. [Department of Physics, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar 364001 (India); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)
2014-06-01
Highlights: • REGa{sub 3} (RE = Sc or Lu) compounds are mechanical stabile. • Both ScGa{sub 3} and LuGa{sub 3} exhibit metallic behavior just like other REGa{sub 3} compounds. • Melting temperature T{sub m} (K) for ScGa{sub 3} and LuGa{sub 3} are 1244.2 and 1143.8. • High absorption observed in the visible energy region. • The present study would be helpful for future experimental/theoretical explorations. - Abstract: Structural, elastic, optoelectronic and thermodynamic properties of REGa{sub 3} (RE = Sc and Lu) compounds have been studied self consistently by employing state of the art full potential (FP) linearized (L) approach of augmented plane wave (APW) plus local orbitals method. Calculations were executed at the level of Perdew–Burke and Ernzerhof (PBE) parameterized generalized gradient approximation (GGA) for exchange correlation functional in addition to modified Becke–Johnson (mBJ) potential. Our obtained results of lattice parameters show reasonable agreement to the previously reported experimental and other theoretical studies. Analysis of the calculated band structure of ScGa{sub 3} and LuGa{sub 3} compounds demonstrates their metallic character. Moreover, a positive value of calculated Cauchy pressure, in addition to reflecting their ductile nature, endorses their metallic character as well. To understand optical behavior calculations related to the important optical parameters; real and imaginary parts of the dielectric function, reflectivity R(ω), refractive index n(ω) and electron energy-loss function L(ω) have also been performed. In the present work, thermodynamically properties are also investigated by employing lattice vibrations integrated in quasi harmonic Debye model. Obtained results of volume, heat capacity and Debye temperature as a function of temperature for both compounds, at different values of pressure, are found to be consistent. The calculated value of melting temperature for both compounds (ScGa{sub 3} and Lu
Let Students Discover an Important Physical Property of a Slinky
Gash, Philip
2016-01-01
This paper describes a simple experiment that lets first-year physics and engineering students discover an important physical property of a Slinky. The restoring force for the fundamental oscillation frequency is provided only by those coils between the support and the Slinky center of mass.
Czech Academy of Sciences Publication Activity Database
Pátek, Jaroslav; Klomfar, Jaroslav
2006-01-01
Roč. 29, č. 4 (2006), s. 566-578 ISSN 0140-7007 Institutional research plan: CEZ:AV0Z20760514 Keywords : water-lithium bromide * aqueous solution * thermodynamic properties Subject RIV: BJ - Thermodynamics Impact factor: 0.936, year: 2006
Dar, Sajad Ahmad; Srivastava, Vipul; Sakalle, Umesh Kumar; Rashid, Adil; Pagare, Gitanjali
2018-02-01
Theoretical investigation on electronic structural, magnetic, mechanical and thermodynamic properties of SrPuO3 perovskite oxide has been accomplished within density functional theory (DFT). For exchange correlations generalized gradient approximation (GGA), on-site coulomb repulsion (GGA + U) and modified Becke-Johnson (mBJ) have been used. The calculated structural parameters including lattice constant were found in good agreement with the available experimental and theoretical results. The spin polarized electronic band structure and density of states present half-metallic nature for the compound with majority spin (spin up states) as metallic and minority spin (spin down states) as semi-conducting. The large value of magnetic moment equal to 4 μ B was found for the compound. Elastic and mechanical properties have been predicted under ambient conditions. Moreover, thermodynamic parameters like Debye temperature (θ D), specific heat (CV), entropy (S) etc have been calculated using quasi-harmonic Debye model under different temperature and pressure values.
Thermodynamic and transport properties of frozen and reacting pH2-oH2 mixtures
Carter, H. G.; Bullock, R. E.
1972-01-01
Application of experimental state data and spectroscopic term values shows that the thermodynamic and transport properties of reacting pH2-oH2 mixtures are considerably different than those of chemically frozen pH2 at temperatures below 300 R. Calculated H-S data also show that radiation-induced pH2-oH2 equilibration at constant enthalpy produces a temperature drop of at least 28 R, corresponding to an ideal shaft work loss of 15% or more for a turbine operating downstream from the point of conversion. Aside from differences in thermodynamic and transport properties, frozen pH2-oH2 mixtures may differ from pure pH2 on a purely hydrodynamical basis.
Pascal, Tod A.; Karasawa, Naoki; Goddard, William A.
2010-10-01
As assemblies of graphene sheets, carbon nanotubes, and fullerenes become components of new nanotechnologies, it is important to be able to predict the structures and properties of these systems. A problem has been that the level of quantum mechanics practical for such systems (density functional theory at the PBE level) cannot describe the London dispersion forces responsible for interaction of the graphene planes (thus graphite falls apart into graphene sheets). To provide a basis for describing these London interactions, we derive the quantum mechanics based force field for carbon (QMFF-Cx) by fitting to results from density functional theory calculations at the M06-2X level, which demonstrates accuracies for a broad class of molecules at short and medium range intermolecular distances. We carried out calculations on the dehydrogenated coronene (C24) dimer, emphasizing two geometries: parallel-displaced X (close to the observed structure in graphite crystal) and PD-Y (the lowest energy transition state for sliding graphene sheets with respect to each other). A third, eclipsed geometry is calculated to be much higher in energy. The QMFF-Cx force field leads to accurate predictions of available experimental mechanical and thermodynamics data of graphite (lattice vibrations, elastic constants, Poisson ratios, lattice modes, phonon dispersion curves, specific heat, and thermal expansion). This validates the use of M06-2X as a practical method for development of new first principles based generations of QMFF force fields.
Energy Technology Data Exchange (ETDEWEB)
Santana, P. [Departamento de Fisica Aplicada, Facultad de Fisica, Universidad de Santiago, E-15782 Santiago de Compostela (Spain); Mato, M.M.; Paz Andrade, C.; Carballo, E. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Vigo, E-36200 Vigo (Spain); Jimenez, E. [Departamento de Fisica, Facultade de Ciencias, Universidad de A Coruna, E-15071 A Coruna (Spain); Legido, J.L. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Vigo, E-36200 Vigo (Spain); Paz Andrade, M.I. [Departamento de Fisica Aplicada, Facultad de Fisica, Universidad de Santiago, E-15782 Santiago de Compostela (Spain)], E-mail: fapazand@usc.es
2007-10-15
The interaction parameters between group chloro (-Cl) and hydroxyl (-OH) for the group contribution model of Nitta et al. 1977 (Nitta-Chao model) have been estimated with the use of a data base of experimental thermodynamic properties. The results obtained by the Nitta-Chao model with these new parameters were compared with predictions by other models such as UNIFAC model (versions of Dang and Tassios 1986, Larsen et al. 1987 and Gmehling et al. 1993)
Czech Academy of Sciences Publication Activity Database
Adineh, V.R.; Coufal, O.; Živný, Oldřich
2012-01-01
Roč. 40, č. 10 (2012), s. 2723-2735 ISSN 0093-3813 R&D Projects: GA ČR GAP205/11/2070 Institutional research plan: CEZ:AV0Z20430508 Keywords : Electrical discharge machining * net emission coefficient * nitrogen-iron reaction products * plasma modeling, radiative heat transfer * thermodynamic properties Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.868, year: 2012
Gordon, S.
1982-01-01
The equilibrium compositions that correspond to the thermodynamic and transport combustion properties for a wide range of conditions for the reaction of hydrocarbons with air are presented. Initially 55 gaseous species and 3 coin condensed species were considered in the calculations. Only 17 of these 55 gaseous species had equilibrium mole fractions greater than 0.000005 for any of the conditions studied and therefore these were the only ones retained in the final tables.
Thermodynamics of Pb(ii) and Zn(ii) binding to MT-3, a neurologically important metallothionein.
Carpenter, M C; Shami Shah, A; DeSilva, S; Gleaton, A; Su, A; Goundie, B; Croteau, M L; Stevenson, M J; Wilcox, D E; Austin, R N
2016-06-01
Isothermal titration calorimetry (ITC) was used to quantify the thermodynamics of Pb(2+) and Zn(2+) binding to metallothionein-3 (MT-3). Pb(2+) binds to zinc-replete Zn7MT-3 displacing each zinc ion with a similar change in free energy (ΔG) and enthalpy (ΔH). EDTA chelation measurements of Zn7MT-3 and Pb7MT-3 reveal that both metal ions are extracted in a tri-phasic process, indicating that they bind to the protein in three populations with different binding thermodynamics. Metal binding is entropically favoured, with an enthalpic penalty that reflects the enthalpic cost of cysteine deprotonation accompanying thiolate ligation of the metal ions. These data indicate that Pb(2+) binding to both apo MT-3 and Zn7MT-3 is thermodynamically favourable, and implicate MT-3 in neuronal lead biochemistry.
Deng, Juanli; Su, Kehe; Zeng, Yan; Wang, Xin; Zeng, Qingfeng; Cheng, Laifei; Xu, Yongdong; Zhang, Litong
2008-09-01
Density functional theory, high-level model chemistry at G3(MP2), CBS-Q, G3//B3LYP, G3(QCI) and QCISD(T)/aug-cc-pv5z levels of theory combined with statistical thermodynamics have been employed to explore the thermodynamic properties of gaseous SiC(X 3Π) and SiC(a 1Σ). The heat capacities and entropies are obtained via statistical thermodynamics with the structure, vibrational frequency and the electronic excitations calculated at B3PW91/6-31G(d) and B3PW91/6-311G(d) levels. The importance of the anharmonic corrections and the electronic excitations is examined. The reliability of the electronic excitation energies calculated with the time dependent density functional method is tested. The heat capacities and entropies of the ground state SiC(XΠ) calculated in this work are consistent with other theoretical work but different from those in the JANAF Tables. The enthalpies of formation and the Gibbs free energies of formation are in excellent agreement with the calculated results from one experiment but are higher than another observation.
Energy Technology Data Exchange (ETDEWEB)
Capaz, Rodrigo B. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); ElMassalami, M., E-mail: massalam@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); Terrazos, L.A. [Centro de Educação e Saúde, Universidade Federal de Campina Grande, Cuité, PB 58175-000 (Brazil); Elhadi, M. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); Takeya, H. [National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, 305-0047 (Japan); Ghivelder, L. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil)
2016-06-05
Using a combination of theoretical (first-principles total-energy and electronic structure calculations) as well as experimental (structural, thermodynamics) techniques, we systematically investigated the influence of B incorporation on the structural, electronic and thermodynamic properties of a series of technologically-important B-containing AlNi matrix. Special attention was paid to calculating the energy cost of placing B at various sites within the cubic unit cell. The most energetically favorable defects were identified to be, depending on initial stoichiometry, substitutional B at Al site (B{sub Al}), Ni vacancy (V{sub Ni}), or Ni antisite (Ni{sub Al}). We show that the induced variation in the lattice parameters can be correlated with the type and concentration of the involved defects: e.g. the surge of V{sub Ni} defects leads to a stronger lattice-parameter reduction, that of Ni{sub Al} ones to a relatively weaker reduction while that of B{sub Al} defects to a much weaker influence. Both electronic band structure calculations as well as thermodynamics measurements indicate that the 3d bands of Ni are fully occupied and magnetically unpolarized and that the resulting N(E{sub F}) is very small: all studied compounds are normal conductors with no trace of superconductivity or magnetic polarization.
Ben-Naim, Arieh
2017-01-01
This textbook introduces thermodynamics with a modern approach, starting from four fundamental physical facts (the atomic nature of matter, the indistinguishability of atoms and molecules of the same species, the uncertainty principle, and the existence of equilibrium states) and analyzing the behavior of complex systems with the tools of information theory, in particular with Shannon's measure of information (or SMI), which can be defined on any probability distribution. SMI is defined and its properties and time evolution are illustrated, and it is shown that the entropy is a particular type of SMI, i.e. the SMI related to the phase-space distribution for a macroscopic system at equilibrium. The connection to SMI allows the reader to understand what entropy is and why isolated systems follow the Second Law of Thermodynamics. The Second Llaw is also formulated for other systems, not thermally isolated and even open with respect to the transfer of particles. All the fundamental aspects of thermodynamics are d...
Khedr, M. Bahaa; Osman, S. M.
2011-10-01
A brief review is presented for the pre-history and discovery of fullerenes. Single-site potentials with parameters proposed by Girifalco was used to describe the interactions of the fullerene molecules C70 and C96. We present theoretical model for calculating the thermodynamic properties of liquid for both C70 and C96 by means of an improved equation of state (EOS), in which the particles are interacting via pair wise interaction composed of suitable linear combination of three Yukawa functions (3YK). The proposed equation of state provides a powerful mathematical formalism for the Helmholtz free energy and the pressure within the series mean-spherical approximation (SMSA) which are the basic ingredients to compute the liquid-vapour coexistence curve of C70 and C96 as well as the other thermodynamic properties for the bulk liquid and the vapour phases. The comparisons with Gibbs ensemble Monte Carlo (GEMC) simulations and the self-consistent Ornstein-Zernike approximation (SCOZA) were carried out. The estimated critical parameters for both C70 and C96 are TC = 2176 K, ρC = 0.44 nm-3, PC = 51.64 bars and TC = 2477 K, ρC = 0.32 nm-3, PC = 44.28 bars respectively. It is to be noted that the obtained results of the thermodynamic properties along the binodal curves of C70 and C96 are exhibit interesting features.
Synthesis, Properties and Mineralogy of Important Inorganic Materials
Warner, Terence E
2010-01-01
Intended as a textbook for courses involving preparative solid-state chemistry, this book offers clear and detailed descriptions on how to prepare a selection of inorganic materials that exhibit important optical, magnetic and electrical properties, on a laboratory scale. The text covers a wide range of preparative methods and can be read as separate, independent chapters or as a unified coherent body of work. Discussions of various chemical systems reveal how the properties of a material can often be influenced by modifications to the preparative procedure, and vice versa. References to miner
International Nuclear Information System (INIS)
Koukouvetakis, J.
1988-01-01
The γ-MoC phase with the hexagonal WC structure was prepared without the presence of metal stabilizers at temperatures below 1000 degree C. This phase was found to be thermodynamically stable at low temperatures and decomposed to Mo 2 C and graphite at 1400 K. Using equilibrium and thermodynamic data, the thermodynamic quantities of this phase were calculated. Oxide equilibration and solid-state galvanic cell experiments were used to study thermodynamic properties of binary Lewis acid-base stabilized transition-metal alloys. The activity of vanadium was determined in alloys of vanadium with platinum-group metals such as Rh, Pd, and Ir at 1000 degree C. The activities of titanium in titanium-iridium alloys and of niobium in Nb 3 Ir were determined at 1400 degree C. The ternary phase diagram of V-Pd-O at 1000 degree C was obtained. Based on the vanadium-palladium results, a partial titration curve of palladium by vanadium was constructed. The excess partial molar Gibbs free energy of vanadium at infinite dilution was found to be -36.4 kcal mol -1 at 1000 degree C. Results are in agreement with the predictions of Brewer's theory of transition-metal alloy acid-base behavior
Introduction to applied thermodynamics
Helsdon, R M; Walker, G E
1965-01-01
Introduction to Applied Thermodynamics is an introductory text on applied thermodynamics and covers topics ranging from energy and temperature to reversibility and entropy, the first and second laws of thermodynamics, and the properties of ideal gases. Standard air cycles and the thermodynamic properties of pure substances are also discussed, together with gas compressors, combustion, and psychrometry. This volume is comprised of 16 chapters and begins with an overview of the concept of energy as well as the macroscopic and molecular approaches to thermodynamics. The following chapters focus o
Oktavian, Rama; Darmawan, Rhezaldian Eka; Diarahmawati, Ayu; Kartiko, Intan Dyah; Rachmawati, Rizqi Tri
2017-03-01
The increasing consumption of fossil fuel in Indonesia is not followed by the rising on domestic oil production. This will lead to the depletion of fossil fuel reserves that will affect the availability of energy resources. Biofuel is considered as the critical solution to solve this problem in Indonesia. In recent years, alcohol produced from biomass has been used as an oxygenated compound in gasoline to increase the octane number and reduce pollutants resulting from motor vehicle exhaust emissions. However, the use of alcohol as an additive compounds is still limited to ethanol. In fact, the use of higher-chain alcohol such as 1-butanol offers more benefits over ethanol due to its higher calorific value. 1-butanol also has good characteristics for gasoline mixture such as less corrosive than ethanol, more resistant to water contamination, its low vapor pressure which leads to more safety application. This work investigated the effect of 1-butanol addition on the thermodynamic properties of gasoline-ethanol blend, in the form of density values, isobaric expansion coefficient, and the calorific value. The addition of 1-butanol up to 15% weight (80% RON 92-5% ethanol-15% 1-butanol) gives higher density to alcohol-gasoline blend up to 2% compared with pure RON 92 gasoline. Moreover, this addition produces the calorific value of gasoline blend of 11,313 cal/gr compared to pure RON 92 gasoline with the calorific value of 12,117 cal/gram. This blend can reduce the RON 92 gasoline consumption up to 15% from calorific value perspective.
Martelli, Fausto; Vuilleumier, Rodolphe; Simonin, Jean-Pierre; Spezia, Riccardo
2012-10-01
In this work, we show how increasing the charge of small cations affects the structural, thermodynamical, and dynamical properties of these ions in liquid water. We have studied the case of lanthanoid and actinoid ions, for which we have recently developed accurate polarizable force fields, and the ionic radius is in the 0.995-1.250 Å range, and explored the valency range from 0 to 4+. We found that the ion charge strongly structures the neighboring water molecules and that, in this range of charges, the hydration enthalpies exhibit a quadratic dependence with respect to the charge, in line with the Born model. The diffusion process follows two main regimes: a hydrodynamical regime for neutral or low charges, and a dielectric friction regime for high charges in which the contraction of the ionic radius along the series of elements causes a decrease of the diffusion coefficient. This latter behavior can be qualitatively described by theoretical models, such as the Zwanzig and the solvated ion models. However, these models need be modified in order to obtain agreement with the observed behavior in the full charge range. We have thus modified the solvated ion model by introducing a dependence of the bare ion radius as a function of the ionic charge. Besides agreement between theory and simulation this modification allows one to obtain an empirical unified model. Thus, by analyzing the contributions to the drag coefficient from the viscous and the dielectric terms, we are able to explain the transition from a regime in which the effect of viscosity dominates to one in which dielectric friction governs the motion of ions with radii of ca. 1 Å.
Mehta, A. V.; Smith, E. A.; Tripoli, G. J.
2008-12-01
It is well known that precipitating convection within tropical cyclones result from a complex interactions among large-scale, storm-scale, cloud-scale, and micro-scale processes. For improved representation of these processes within tropical cyclone models, it is crucial to first understand how micro-scale and cloud- scale properties within tropical cyclones are related to large-scale processes, one of the key objectives of the Year of Tropical Convection (YOTC) program. In this study, a combination of cloud resolving model (CRM) simulations, TRMM Microwave Imager (TMI) measurements, NOAA Optimum Interpolation sea surface temperatures (SST), and Global Forecasting System (GFS) analysis are used to address this issue. The University of Wisconsin Nonhydrostatic Modeling System (UWNMS), a CRM, is used to simulate hurricanes Dennis (9-10 July 2005), Katrina (29-30 2005), and Gustav (30-31 August 2008) at 2-km resolution, nested within 1ºx1º GFS analyses. The UWNMS-generated thermodynamic and hydrometeor profiles are used in a radiative transfer model to calculate brightness temperatures (Tbs) at TMI frequencies. The UWNMS-based Tbs and TRMM-based Tbs are compared to validate overall consistency of the CRM simulations. The cloud-scale profiles of hydrometeors, vertical wind, temperature, and wind shear from UWNMS are analyzed to study their characteristics as functions of SST and GFS-based large-scale regimes represented by parameters including horizontal moisture divergence, vertical moisture flux at 500 hPa, potential vorticity, large-scale wind shear, and Convective Available Potential Energy among others, throughout mature stage of these major hurricanes. Results of this study show how cloud-scale processes are related to large-scale processes within these tropical cyclones.
Application of Statistical Thermodynamics in Refrigeration
International Nuclear Information System (INIS)
Avsec, J.; Marcic, M.
1999-01-01
The paper presents the mathematical model for computing the thermodynamical properties in the liquid, gas and two-phase domain by means of statistical thermodynamics. The paper features all important components (translation, rotation, internal rotation, vibration, intermolecular potential energy and influence of electron and nuclei excitation). To calculate the thermodynamic properties of real gases, we have developed the cluster theory, which yields better results than the virial equation. In case of real liquids, the Johnson-Zollweg-Gubbins model based on the modified Benedict-Webb-Rubin (BWR) equation was applied. The Lennard-Jones intermolecular potential was used. The analytical results are compared with the thermodynamical data and models obtained from classical thermodynamics, and they show relatively good agreement. (author)
Thermodynamic Analysis of Biodegradation Pathways
Finley, Stacey D.; Broadbelt, Linda J.
2014-01-01
Microorganisms provide a wealth of biodegradative potential in the reduction and elimination of xenobiotic compounds in the environment. One useful metric to evaluate potential biodegradation pathways is thermodynamic feasibility. However, experimental data for the thermodynamic properties of xenobiotics is scarce. The present work uses a group contribution method to study the thermodynamic properties of the University of Minnesota Biocatalysis/Biodegradation Database. The Gibbs free energies of formation and reaction are estimated for 914 compounds (81%) and 902 reactions (75%), respectively, in the database. The reactions are classified based on the minimum and maximum Gibbs free energy values, which accounts for uncertainty in the free energy estimates and a feasible concentration range relevant to biodegradation. Using the free energy estimates, the cumulative free energy change of 89 biodegradation pathways (51%) in the database could be estimated. A comparison of the likelihood of the biotransformation rules in the Pathway Prediction System and their thermodynamic feasibility was then carried out. This analysis revealed that when evaluating the feasibility of biodegradation pathways, it is important to consider the thermodynamic topology of the reactions in the context of the complete pathway. Group contribution is shown to be a viable tool for estimating, a priori, the thermodynamic feasibility and the relative likelihood of alternative biodegradation reactions. This work offers a useful tool to a broad range of researchers interested in estimating the feasibility of the reactions in existing or novel biodegradation pathways. PMID:19288443
Classical and statistical thermodynamics
Rizk, Hanna A
2016-01-01
This is a text book of thermodynamics for the student who seeks thorough training in science or engineering. Systematic and thorough treatment of the fundamental principles rather than presenting the large mass of facts has been stressed. The book includes some of the historical and humanistic background of thermodynamics, but without affecting the continuity of the analytical treatment. For a clearer and more profound understanding of thermodynamics this book is highly recommended. In this respect, the author believes that a sound grounding in classical thermodynamics is an essential prerequisite for the understanding of statistical thermodynamics. Such a book comprising the two wide branches of thermodynamics is in fact unprecedented. Being a written work dealing systematically with the two main branches of thermodynamics, namely classical thermodynamics and statistical thermodynamics, together with some important indexes under only one cover, this treatise is so eminently useful.
EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL
Energy Technology Data Exchange (ETDEWEB)
Ramanathan Sampath
2000-01-01
This final technical report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period September 24, 1996 to September 23, 1999 which covers the entire performance period of the project. During this period, modification, alignment, and calibration of the measurement system, measurement of devolatilization time-scales for single coal particles subjected to a range of heating rates and temperature data at these time-scales, and analysis of the temperature data to understand the effect of heating rates on coal thermal properties were carried out. A new thermodynamic model was developed to predict the heat transfer behavior for single coal particles using one approach based on the analogy for thermal property of polymers. Results of this model suggest that bituminous coal particles behave like polymers during rapid heating on the order of 10{sup 4}-10{sup 5} K/s. At these heating rates during the early stages of heating, the vibrational part of the heat capacity of the coal molecules appears to be still frozen but during the transition from heat-up to devolatilization, the heat capacity appears to attain a sudden jump in its value as in the case of polymers. There are a few data available in the coal literature for low heating rate experiments (10{sup 2}-10{sup 3} K/s) conducted by UTRC, our industrial partner, in this project. These data were obtained for a longer heating duration on the order of several seconds as opposed to the 10 milliseconds heating time of the single particle experiments discussed above. The polymer analogy model was modified to include longer heating time on the order of several seconds to test these data. However, the model failed to predict these low heating rate data. It should be noted that UTRC's work showed reasonably good agreement with Merrick model heat capacity predictions at these low heating rates, but at higher heating rates UTRC observed that coal thermal response was heat flux dependent. It is concluded
Determination of the thermodynamic properties of complexation and extraction by micro-calorimetry
International Nuclear Information System (INIS)
Charbonnel, M.Ch.; Flandin, J.L.
2000-01-01
The CEA is currently developing the DIAMEX process, the first step in the strategy for the separation of minor actinides from high-level radioactive waste. The extractant belongs to the diamide family of molecules and is able to co-extract trivalent actinides and lanthanides. This study focuses on the thermodynamic properties (ΔH, ΔG, ΔS) of lanthanide extraction by malonamide in order to better understand the mechanisms involved and to account for differences in the behavior of various diamide extractants. The main technique used is microcalorimetric titration. The Thermal Activity Monitor (TAM) microcalorimeter is a modular system with a highly stable (± 0.1 mK) temperature-controlled bath containing up to four calorimetry vessel units. The sensor bulbs inserted in the reaction vessel can measure heat flows in static or dynamic conditions. Micro-calorimetry, and calorimetric titration in particular, is a fast growing field due to technical improvements in both hardware and software. In the case of an equilibrium reaction, titration allows both Δ r G and Δ r H (and thus Δ r S) to be determined simultaneously. It was decided to initiate this thermochemical investigation with a homogeneous phase reaction, and the first study concerned the aqueous phase complexation of a trivalent lanthanide ion by a water-soluble diamide, tetraethyl-malonamide (TEMA: (C 2 H 5 ) 2 NCO-CH 2 CON(C 2 H 5 ) 2 ). In the test system, the heat of dilution of the diamide in water is preponderant over the heat arising from the complexation reaction; the result is a positive value corresponding to an endothermic reaction. However, the equilibration constant K and Δ H are both very small, and cannot be calculated from the resulting Q v f(n TEMA ) curves. Moreover, in aqueous phase, the reactions involved are different from those observed when neodymium(III) is extracted into an organic phase, and the medium must be further characterized before the calorimetry data can be fully
Urrutia, Ignacio
2014-12-28
This work is devoted to analyze the relation between the thermodynamic properties of a confined fluid and the shape of its confining vessel. Recently, new insights in this topic were found through the study of cluster integrals for inhomogeneous fluids that revealed the dependence on the vessel shape of the low density behavior of the system. Here, the statistical mechanics and thermodynamics of fluids confined in wedges or by edges is revisited, focusing on their cluster integrals. In particular, the well known hard sphere fluid, which was not studied in this framework so far, is analyzed under confinement and its thermodynamic properties are analytically studied up to order two in the density. Furthermore, the analysis is extended to the confinement produced by a corrugated wall. These results rely on the obtained analytic expression for the second cluster integral of the confined hard sphere system as a function of the opening dihedral angle 0 < β < 2π. It enables a unified approach to both wedges and edges.
Ha, Vu Thi Thanh; Hung, Vu Van; Hanh, Pham Thi Minh; Tuyen, Nguyen Viet; Hai, Tran Thi; Hieu, Ho Khac
2018-03-01
The thermodynamic and mechanical properties of III-V zinc-blende AlP, InP semiconductors and their alloys have been studied in detail from statistical moment method taking into account the anharmonicity effects of the lattice vibrations. The nearest neighbor distance, thermal expansion coefficient, bulk moduli, specific heats at the constant volume and constant pressure of the zincblende AlP, InP and AlyIn1-yP alloys are calculated as functions of the temperature. The statistical moment method calculations are performed by using the many-body Stillinger-Weber potential. The concentration dependences of the thermodynamic quantities of zinc-blende AlyIn1-yP crystals have also been discussed and compared with those of the experimental results. Our results are reasonable agreement with earlier density functional theory calculations and can provide useful qualitative information for future experiments. The moment method then can be developed extensively for studying the atomistic structure and thermodynamic properties of nanoscale materials as well.
Sologubov, S. S.; Markin, A. V.; Smirnova, N. N.; Novozhilova, N. A.; Tatarinova, E. A.; Muzafarov, A. M.
2018-02-01
The heat capacity of a first-generation carbosilane dendrimer with terminal phenylethyl groups as a function of temperature in the range from 6 to 520 K is studied for the first time via precision adiabatic vacuum calorimetry and differential scanning calorimetry. Physical transformations, such as low-temperature structural anomaly and glass transition are detected in the above-mentioned range of temperatures, and their standard thermodynamic characteristics are determined and analyzed. The standard thermodynamic functions of the studied dendrimer in the range of T → 0 to 520 K are calculated from the experimental data, as is the standard entropy in the devitrified state at T = 298.15 K. The standard thermodynamic characteristics of the carbosilane dendrimers studied in this work and earlier are compared.
Eichhorn, Ralf; Aurell, Erik
2014-04-01
'Stochastic thermodynamics as a conceptual framework combines the stochastic energetics approach introduced a decade ago by Sekimoto [1] with the idea that entropy can consistently be assigned to a single fluctuating trajectory [2]'. This quote, taken from Udo Seifert's [3] 2008 review, nicely summarizes the basic ideas behind stochastic thermodynamics: for small systems, driven by external forces and in contact with a heat bath at a well-defined temperature, stochastic energetics [4] defines the exchanged work and heat along a single fluctuating trajectory and connects them to changes in the internal (system) energy by an energy balance analogous to the first law of thermodynamics. Additionally, providing a consistent definition of trajectory-wise entropy production gives rise to second-law-like relations and forms the basis for a 'stochastic thermodynamics' along individual fluctuating trajectories. In order to construct meaningful concepts of work, heat and entropy production for single trajectories, their definitions are based on the stochastic equations of motion modeling the physical system of interest. Because of this, they are valid even for systems that are prevented from equilibrating with the thermal environment by external driving forces (or other sources of non-equilibrium). In that way, the central notions of equilibrium thermodynamics, such as heat, work and entropy, are consistently extended to the non-equilibrium realm. In the (non-equilibrium) ensemble, the trajectory-wise quantities acquire distributions. General statements derived within stochastic thermodynamics typically refer to properties of these distributions, and are valid in the non-equilibrium regime even beyond the linear response. The extension of statistical mechanics and of exact thermodynamic statements to the non-equilibrium realm has been discussed from the early days of statistical mechanics more than 100 years ago. This debate culminated in the development of linear response
The increasing importance of Intellectual Property in Transfusion Medicine.
Hardie, Ian D; Rooney, Catherine
2011-08-01
The Scottish National Blood Transfusion Service (SNBTS) originated in Edinburgh in the 1920's by dentist Jack Copland. Since that time the scope of Transfusion Medicine has broadened significantly to accommodate advances in technologies such as cell isolation, culture and manipulation. Many transfusion services, including SNBTS, now provide expertise both in the traditional field of blood transfusion and the newer, wider field of human cell (including 'adult' and embryonic stem cells) and tissue procurement and culture - in all the new science of "regenerative medicine". This paper describes the importance of Intellectual Property in the provision of Transfusion Medicine today and provides guidance on the management of Intellectual Property so that advances in the field have the best chance of successful translation into clinical practice. Copyright © 2011 Elsevier Ltd. All rights reserved.
Mechanical, Thermodynamic and Electronic Properties of Wurtzite and Zinc-Blende GaN Crystals
Directory of Open Access Journals (Sweden)
Hongbo Qin
2017-12-01
Full Text Available For the limitation of experimental methods in crystal characterization, in this study, the mechanical, thermodynamic and electronic properties of wurtzite and zinc-blende GaN crystals were investigated by first-principles calculations based on density functional theory. Firstly, bulk moduli, shear moduli, elastic moduli and Poisson’s ratios of the two GaN polycrystals were calculated using Voigt and Hill approximations, and the results show wurtzite GaN has larger shear and elastic moduli and exhibits more obvious brittleness. Moreover, both wurtzite and zinc-blende GaN monocrystals present obvious mechanical anisotropic behavior. For wurtzite GaN monocrystal, the maximum and minimum elastic moduli are located at orientations [001] and <111>, respectively, while they are in the orientations <111> and <100> for zinc-blende GaN monocrystal, respectively. Compared to the elastic modulus, the shear moduli of the two GaN monocrystals have completely opposite direction dependences. However, different from elastic and shear moduli, the bulk moduli of the two monocrystals are nearly isotropic, especially for the zinc-blende GaN. Besides, in the wurtzite GaN, Poisson’s ratios at the planes containing [001] axis are anisotropic, and the maximum value is 0.31 which is located at the directions vertical to [001] axis. For zinc-blende GaN, Poisson’s ratios at planes (100 and (111 are isotropic, while the Poisson’s ratio at plane (110 exhibits dramatically anisotropic phenomenon. Additionally, the calculated Debye temperatures of wurtzite and zinc-blende GaN are 641.8 and 620.2 K, respectively. At 300 K, the calculated heat capacities of wurtzite and zinc-blende are 33.6 and 33.5 J mol−1 K−1, respectively. Finally, the band gap is located at the G point for the two crystals, and the band gaps of wurtzite and zinc-blende GaN are 3.62 eV and 3.06 eV, respectively. At the G point, the lowest energy of conduction band in the wurtzite GaN is larger
Energy Technology Data Exchange (ETDEWEB)
Nascimento, Fabiana C. [Fluminense Federal University, Graduate Program in Metallurgical Engineering, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil); Paresque, Mara C.C. [Fluminense Federal University, Graduate Program in Mechanical Engineering, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil); Castro, José A. de [Fluminense Federal University, Graduate Program in Metallurgical Engineering, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil); Jácome, Paulo A.D. [Fluminense Federal University, Graduate Program in Mechanical Engineering, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil); Garcia, Amauri, E-mail: amaurig@fem.unicamp.br [University of Campinas – UNICAMP, Department of Manufacturing and Materials Engineering, 13083-860 Campinas, SP (Brazil); Ferreira, Ivaldo L. [Fluminense Federal University, Graduate Program in Mechanical Engineering, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil)
2015-11-10
Highlights: • A model coupled to a computational thermodynamics software is proposed to compute thermophysical properties. • The model applies to multicomponent alloys and has been validated against experimental results. • Density and specific heat as a function of temperature are computed for Al–Si–Cu alloys. - Abstract: Despite the technological importance of Al–Si–Cu alloys in manufacturing processes involving heat transfer, such as welding, casting and heat treatment, thermophysical properties of this system of alloys are very scarce in the literature. In this paper, a model connected to a computational thermodynamics software is proposed permitting density and specific heats as a function of temperature and enthalpy of transformations to be numerically determined. The model is pre-validated against experimental density as a function of temperature for liquid and solid phases of A319 and 7075 alloys found in the literature and validated against experimental density values for the solid phase of an Al-6 wt%Cu-1 wt%Si alloy determined in the present study. In both cases the numerical predictions are in good agreement with the experimental results. Specific heat and temperatures and heats of transformation are also numerically determined for this ternary Al-based alloy.
Thermodynamic and Structural Properties of C-bearing Supercritical Aqueous Fluids
Seclaman, A. C.; Cohen, R. E.
2016-12-01
Aqueous fluids are important agents of mass transport in the Earth's crust and upper mantle. Their role in the deep mantle is poorly understood due to a lack of thermodynamic data at relevant pressures (P) and temperatures (T). Speciation of volatiles also plays a key role in understanding the reactivity of fluids, and the formation of complex anionic C species in supercritical fluids has been linked to the precipitation of diamond during fluid-rock interaction.1 Models have predicted equilibria between all oxidation states of C in aqueous fluids above 3 GPa.2 First principles approaches can help expand the PT range of models, and give an atomic-level understanding of fluid behavior. We are using first principles molecular dynamics to study the H-C-O system up to pressures of 40 GPa and 2500K, spanning a wide range of C concentrations. Since van der Waals (vdW) interactions play important roles in water and organic complexes we take into account vdW by using the non-local vdW-DF2 functional.3 From this data, we obtained the PVTX equation of state and investigated the dependence of pressure, temperature, and concentration on the C speciation. Water dissociation and the PT stability field of aqueous cations and anions were also investigated. The results of this work contribute to a better understanding of the C mantle cycle. Our work can help significantly expand the data sets employed by models4,5 used in the study of complex rock-fluid interactions. This work is supported by the ERC Advanced grant ToMCaT. 1. Sverjensky, D. A. & Huang, F. Nat. Commun. 53, 1689-1699 (2015). 2. Sverjensky, D. a., Stagno, V. & Huang, F. Nat. Geosci. 7, 909-913 (2014). 3. Lee, K., Murray, É. D., Kong, L., Lundqvist, B. I. & Langreth, D. C. Phys. Rev. B - Condens. Matter Mater. Phys. 82, 3-6 (2010). 4. Sverjensky, D. A., Harrison, B. & Azzolini, D. Geochim. Cosmochim. Acta 129, 125-145 (2014). 5. Ghiorso, M. S. & Gualda, G. A. R. Contrib. to Mineral. Petrol. 169, 1-30 (2015).
Thermodynamic properties of citric acid and the system citric acid-water
Kruif, C.G. de; Miltenburg, J.C. van; Sprenkels, A.J.J.; Stevens, G.; Graaf, W. de; Wit, H.G.M. de
1982-01-01
The binary system citric acid-water has been investigated with static vapour pressure measurements, adiabatic calorimetry, solution calorimetry, solubility measurements and powder X-ray measurements. The data are correlated by thermodynamics and a large part of the phase diagram is given. Molar heat
Schroën, C.G.P.H.; Nierstrasz, V.A.; Kroon, P.J.; Bosma, B.; Janssen, A.E.M.; Beeftink, H.H.; Tramper, J.
1999-01-01
For the enzymatic synthesis of the antibiotic cephalexin, an activated acyl donor is generally used as one of the substrates (kinetically controlled approach); however, the thermodynamically controlled approach might be of interest since there is no need for activation of the acyl donor and less
International Nuclear Information System (INIS)
Magomedov, R A; Meilanov, R P; Akhmedov, E N; Aliverdiev, A A
2016-01-01
The generalization of thermodynamics in formalism of fractional derivatives is presented. One-parametric “fractal” state equation with second virial coefficient is obtained. The calculation of entropy S and compressibility z of the refrigerant freon R409B for the pressure range from 0.01 to 3.8 MPa and temperature range from 210 to 370 K is given. (paper)
Assessment of the thermodynamic properties and phase diagram of the Bi-Pd system
Czech Academy of Sciences Publication Activity Database
Vřešťál, Jan; Pinkas, J.; Watson, A.; Scott, A.; Houserová, Jana; Kroupa, Aleš
2006-01-01
Roč. 30, č. 1 (2006), s. 14-17 ISSN 0364-5916 R&D Projects: GA MŠk OC 531.001; GA MŠk OC 531.002 Institutional research plan: CEZ:AV0Z20410507 Keywords : phase diagram * ab initio calculations * calorimetry Subject RIV: BJ - Thermodynamics Impact factor: 1.432, year: 2006
Correlation of water vapor adsorption behavior of wood with surface thermodynamic properties
Mandla A. Tshabalala; Agnes R. Denes; R. Sam. Williams
1999-01-01
To improve the overall performance of wood-plastic composites, appropriate technologies are needed to control moisture sorption and to improve the interaction of wood fiber with selected hydrophobic matrices. The objective of this study was to determine the surface thermodynamic characteristics of a wood fiber and to correlate those characteristics with the fiberas...
Thermodynamic properties and low-temperature X-ray diffraction of vitamin B{sub 3}
Energy Technology Data Exchange (ETDEWEB)
Knyazev, A.V., E-mail: knyazevav@gmail.com; Smirnova, N.N.; Shipilova, A.S.; Shushunov, A.N.; Gusarova, E.V; Knyazeva, S.S.
2015-03-20
Highlights: • Temperature dependence of heat capacity of vitamin B{sub 3} has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B{sub 3} have been determined for the range from T → 0 to 346 K. • The thermodynamic analysis of reactions involving nicotinic acid was made. • The low-temperature X-ray diffraction was used for the determination of coefficients of thermal expansion. - Abstract: In the present work temperature dependence of heat capacity of vitamin B{sub 3} (nicotinic acid) has been measured for the first time in the range from 5 to 346 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B{sub 3}, namely, the heat capacity, enthalpy H°(T) – H°(0), entropy S°(T) – S°(0) and Gibbs function G°(T) – H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye’s theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermodynamic parameters Δ{sub f}S°, Δ{sub f}G° at T = 298.15 K and p = 0.1 MPa have been calculated. The thermodynamic analysis of reactions involving nicotinic acid was made. The low-temperature X-ray diffraction was used for the determination of coefficients of thermal expansion.
Morrison, J. D.; Barley, M. H.; Murphy, F. T.; Parker, I. B.; Wheelhouse, R. W.
1995-09-01
This paper reports on the development and application of a thermodynamic model based on the second-order Modified Huron Vidal equation of state (MHV-2) to predict the properties of ternary mixtures of the refrigerants R32, R125, and R134a. The mixing rules of this equation of state have been used to incorporate directly an activity-coefficient model for the excess Gibbs free energy. The parameters for the activity-coefficient model have been derived from experimental VLE data for binary mixtures. This methodology has enabled the production of a thermodynamically consistent model which can be used to predict the phase equilibria of R32/R125/R134a mixtures. The input data used in the model are presented in the paper and the predictions of the model are compared with available experimental data. The model has been used to predict the behavior of ternary refrigerant blends of R32/R125/R134a in fractionation scenarios, such as liquid charging and vapor leakage, which are of direct interest to the refrigeration industry. Details of these applications and comparisons with experimental data are discussed, along with other general uses of the thermodynamic model.
International Nuclear Information System (INIS)
Mashadieva, Leyla F.; Aliev, Ziya S.; Shevelkov, Andrei V.; Babanly, Mahammad B.
2013-01-01
Highlights: ► The self-consistent phase diagram of the Ag–Bi–I system is constructed. ► Ag 2 BiI 5 and AgBi 2 I 7 are the only ternary phases of the system. ► Standard thermodynamic functions of formation and the standard entropies of Ag 2 BiI 5 and AgBi 2 I 7 are calculated. - Abstract: The phase equilibriums in the Ag–Bi–I ternary system and thermodynamic properties of the ternary phases were experimentally determined by using DTA and XRD techniques and EMF measurements with the Ag 4 RbI 5 solid electrolyte. According to the obtained experimental results, the polythermal sections of the ternary phase diagram, its isothermal section at 300 K as well as the projection of the liquids surface have been revised. The fields of the primary crystallization and types and coordinates of nonvariant and monovariant equilibriums were determined. The partial molar functions of silver iodide and silver in the alloys as well as the standard thermodynamic functions of formation and the standard entropies of Ag 2 BiI 5 and AgBi 2 I 7 were calculated based on EMF measurements.
International Nuclear Information System (INIS)
Morrison, J.D.; Barley, M.H.; Parker, I.B.
1995-01-01
This paper reports on the development and application of a thermodynamic model based on the second-order Modified Huron Vidal equation of state (MHV-2) to predict the properties of ternary mixtures of the refrigerants R32, R125, and R134a. The mixing rules of this equation of state have been used to incorporate directly an activity-coefficient model for the excess Gibbs free energy. The parameters for the activity-coefficient model have been derived from experimental VLE data for binary mixtures. This methodology has enabled the production of a thermodynamically consistent model which can be used to predict the phase equilibria of R32/R125/R134a mixtures. The input data used in the model are presented in the paper and the predictions of the model are compared with available experimental data. The model has been used to predict the behavior of ternary refrigerant blends of R32/R125/R134a in fractionation scenarios, such as liquid charging and vapor leakage, which are of direct interest to the refrigeration industry. Details of these applications and comparisons with experimental data are discussed, along with other general uses of the thermodynamic model
Structural, thermodynamical, and transport properties of undercooled binary Pd-Ni alloys
International Nuclear Information System (INIS)
Ozdemir Kart, S.; Tomak, M.; UludoGan, M.; CaGin, T.
2006-01-01
The solidification properties of Pd-Ni alloys are studied with constant-pressure, constant-temperature (TPN), and constant-volume, constant-temperature (TVN) molecular dynamics simulations based on quantum Sutton-Chen potential. Whether the system forms the glass structure or it transforms into ordered state is checked at various cooling rates ranging from 10-bar K/ps to 0.05-bar K/ps. The effect of concentration and cooling rates on the glass transition temperature is examined. The behavior of heat capacity at constant pressure (C p ) in glass and liquid state is analyzed. Glass forming ability is also investigated by means of transport properties such as diffusion and shear viscosity. Strength parameter calculated from shear viscosity data indicates fragile-liquid behavior. The results show that the mismatch in atomic size and having the eutectic composition are important factors for glass forming
Structural, thermodynamical, and transport properties of undercooled binary Pd-Ni alloys
Energy Technology Data Exchange (ETDEWEB)
Ozdemir Kart, S. [Department of Physics, Pamukkale University, 20020 Denizli (Turkey); Tomak, M. [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); UludoGan, M. [Department of Chemical Engineering, Texas A and M University, TX 77845-3122 (United States); CaGin, T. [Department of Chemical Engineering, Texas A and M University, TX 77845-3122 (United States)]. E-mail: ozsev@pau.edu.tr
2006-11-05
The solidification properties of Pd-Ni alloys are studied with constant-pressure, constant-temperature (TPN), and constant-volume, constant-temperature (TVN) molecular dynamics simulations based on quantum Sutton-Chen potential. Whether the system forms the glass structure or it transforms into ordered state is checked at various cooling rates ranging from 10-bar K/ps to 0.05-bar K/ps. The effect of concentration and cooling rates on the glass transition temperature is examined. The behavior of heat capacity at constant pressure (C{sub p}) in glass and liquid state is analyzed. Glass forming ability is also investigated by means of transport properties such as diffusion and shear viscosity. Strength parameter calculated from shear viscosity data indicates fragile-liquid behavior. The results show that the mismatch in atomic size and having the eutectic composition are important factors for glass forming.
Bahar, Rim; Azzouz, Soufien; Remond, Romain; Ouertani, Sahbi; Elaieb, Mohamed Taher; El Cafci, Mohamed Afif
2017-05-01
The aim of this paper was to determine the moisture desorption isotherms and essentials thermodynamic properties of two Oak wood varieties. Desorption isotherms were measured using a static gravimetric method at 50, 60, 70 and 80 °C within the range of 5-90 % relative humidity. The equilibrium moisture content decreased with increasing temperature and decreased with decreasing relative humidity at a constant temperature. The `Thermodynamic' sorption equation was found to be the best for describing the experimental moisture sorption isotherms of woods within the range of temperature and water activity investigated. The Fiber saturation point, deduced from the `Thermodynamic' model parameters, depends on the temperature and varying from 22.6 to 54.4 (% kg water/kg dry matter). Isosteric heat of desorption and differential entropy were calculated by applying Clausius-Clapeyron equation to the desorption data fitted by the `Thermodynamic' model. The isosteric heat of desorption and the differential entropy decreased with increasing moisture content according to an exponential law equation and varying from 2.03 to 31.14 kJ/mol and from 73.98 to 4.34 J/(mol K), respectively. The linear relationship between differential enthalpy and entropy satisfied the enthalpy-entropy compensation theory. The sign of Gibbs free energy was found to be positive (+283 J/mol) and (+97 J/mol) for Quercus robur and Quercus canariensis, respectively. The isokinetic temperature was found to be greater than the harmonic temperature. Based on the enthalpy-entropy compensation theory, it could be concluded that the moisture desorption isotherm of Oak wood is a non-spontaneous and enthalpy-controlled process.
International Nuclear Information System (INIS)
Hwang, Jeong Ui; Jang, Jong Jae; Jee, Jong Gi
1987-01-01
The contents of this book are thermodynamics on the law of thermodynamics, classical thermodynamics and molecule thermodynamics, basics of molecule thermodynamics, molecule and assembly partition function, molecule partition function, classical molecule partition function, thermodynamics function for ideal assembly in fixed system, thermodynamics function for ideal assembly in running system, Maxwell-Boltzmann's law of distribution, chemical equilibrium like calculation of equilibrium constant and theory of absolute reaction rate.
Wang, Xiao-Dan; Han, Chun; Fan, Hong-Tao
2015-07-01
Task-specific ionic liquid 1-butyl-3-methylimidazolium salicylate ([BMI]Sal) was synthesized in two steps. In the temperature range of 298.15-353.15 K, the density and surface tension for pure ionic liquid were determined and the thermodynamic properties of the ionic liquid were discussed in terms of Glasser's theory. The standard molar entropy and lattice energy for [BMI]Sal have been estimated. In addition, the thermal expansion coefficient, α = 5.53 × 10-4 K-1, calculated by the interstice model is in extreme agreement with α (experimental) = 5.50 × 10-4 K-1.
Thermodynamic Properties of Low-Density {}^{132}Xe Gas in the Temperature Range 165-275 K
Akour, Abdulrahman
2018-01-01
The method of static fluctuation approximation was used to calculate selected thermodynamic properties (internal energy, entropy, energy capacity, and pressure) for xenon in a particularly low-temperature range (165-270 K) under different conditions. This integrated microscopic study started from an initial basic assumption as the main input. The basic assumption in this method was to replace the local field operator with its mean value, then numerically solve a closed set of nonlinear equations using an iterative method, considering the Hartree-Fock B2-type dispersion potential as the most appropriate potential for xenon. The results are in very good agreement with those of an ideal gas.
Thermodynamic properties of LiCl solutions in N-methylacetamide at 308.15-328.15 K
Manin, N. G.; Kolker, A. M.
2017-12-01
Enthalpies of dissolution of crystalline LiCl and enthalpies of dilution of LiCl solutions in N-methylacetamide (NMA) with electrolyte concentrations no greater than 0.32 m are measured on an isoperibolic calorimeter at 308.15, 318.15, and 328.5 K. Standard enthalpies of the dissolution of LiCl in NMA are calculated at different temperatures. The thermodynamic properties of the solution and its components are calculated and analyzed in the investigated range of concentrations and temperatures.
Kinetic and thermodynamic properties of two barley thioredoxin h isozymes, HvTrxh1 and HvTrxh2
DEFF Research Database (Denmark)
Maeda, Kenji; Hägglund, Per; Björnberg, Olof
2010-01-01
Barley thioredoxin h isozymes 1 (HvTrxh1) and barley thioredoxin h isozymes 2 (HvTrxh2) show distinct spatiotemporal distribution in germinating seeds. Using a novel approach involving measurement of bidirectional electron transfer rates between Escherichia coli thioredoxin, which exhibits redox......-dependent fluorescence, and the barley isozymes, reaction kinetics and thermodynamic properties were readily determined. The reaction constants were 60% higher for HvTrxh1 than HvTrxh2, while their redox potentials were very similar. The primary nucleophile, Cys(N), of the active site Trp-Cys(N)-Gly-Pro-Cys...
Thermodynamic properties of isobutane-isopentane mixtures from -40 to +600(0)F and up to 1000 psia
Gallagher, J. S.; Sengers, J. M. H. L.; Morrison, G.; Sengers, J. V.
1984-07-01
The Helmboltz function for pure isobutane from a recent correlation was converted to a dimensionless form and a pressure enthalpy chart based on this function was generated by computer. A Helmholtz function for mixtures of isobutane and isopentane was formed based upon the dimensionless corresponding states principle. Scarce literature data for saturation properties of isopentane, and new data for its vapor pressure and for the critical line of the mixture, were used. The accuracy of the surface was checked by comparing with literature enthalpy data and with new VLE data for the mixture. Tables of thermodynamic properties were generated from this Helmholtz function for the 0.1 mole fraction isopentane-in-isobutane mixture in the single phase region and on the dew and bubble point curves, together with properties of the coexisting phase. A pressure enthalpy chart for this mixture was also generated.
Kablov, Eugene N; Stolyarova, Valentina L; Lopatin, Sergey I; Vorozhtcov, Viktor A; Karachevtsev, Fedor N; Folomeikin, Yuriy I
2017-07-15
The refractory properties of the Gd 2 O 3 -Y 2 O 3 -HfO 2 system are considered promising for the production of many high-temperature materials, e.g., thermal barrier coatings and casting molds for gas turbine engine blades. At high temperatures, components of the Gd 2 O 3 -Y 2 O 3 -HfO 2 system may vaporize selectively and this may significantly change the physicochemical properties of the materials. Therefore, information on vaporization processes and thermodynamic properties of the Gd 2 O 3 -Y 2 O 3 -HfO 2 system is of great importance. The vaporization processes and thermodynamic properties of the Gd 2 O 3 -Y 2 O 3 -HfO 2 system were studied using high-temperature Knudsen effusion mass spectrometry with a MS-1301 mass spectrometer. Vaporization was carried out using a tungsten twin effusion cell containing the samples under study and pure Gd 2 O 3 as a reference substance. Electron ionization at an energy of 25 eV was employed in the present study. It was shown that at a temperature of 2500 K the vapor over the samples in the Gd 2 O 3 -Y 2 O 3 -HfO 2 system consisted of the GdO, YO and O vapor species. The Gd 2 O 3 and Y 2 O 3 activities in the samples in the Gd 2 O 3 -Y 2 O 3 -HfO 2 system as well as their vaporization rates were derived from the partial pressures of the vapor species. Using these data the HfO 2 activities, the Gibbs energy of mixing and the excess Gibbs energy in this system were calculated at 2500 K. The thermodynamic properties of the Gd 2 O 3 -Y 2 O 3 -HfO 2 system, i.e., the component activities in the samples and the excess Gibbs energy, obtained in the present study at 2500 K, exhibited negative deviations from ideal behavior. The concentration dependence of excess Gibbs energy of the Gd 2 O 3 -Y 2 O 3 -HfO 2 system was approximated with an empirical equation. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Atomistic computer simulations of FePt nanoparticles. Thermodynamic and kinetic properties
Energy Technology Data Exchange (ETDEWEB)
Mueller, M.
2007-12-20
In the present dissertation, a hierarchical multiscale approach for modeling FePt nanoparticles by atomistic computer simulations is developed. By describing the interatomic interactions on different levels of sophistication, various time and length scales can be accessed. Methods range from static quantum-mechanic total-energy calculations of small periodic systems to simulations of whole particles over an extended time by using simple lattice Hamiltonians. By employing these methods, the energetic and thermodynamic stability of non-crystalline multiply twinned FePt nanoparticles is investigated. Subsequently, the thermodynamics of the order-disorder transition in FePt nanoparticles is analyzed, including the influence of particle size, composition and modified surface energies by different chemical surroundings. In order to identify processes that reduce or enhance the rate of transformation from the disordered to the ordered state, the kinetics of the ordering transition in FePt nanoparticles is finally investigated by assessing the contributions of surface and volume diffusion. (orig.)
Property Uncertainty Analysis and Methods for Optimal Working Fluids of Thermodynamic Cycles
DEFF Research Database (Denmark)
Frutiger, Jerome
There is an increasing interest in recovering industrial waste heat at low tempera-tures (70-250◦C). Thermodynamic cycles, such as heat pumps or organic Rankine cycles, can recover this heat and transfer it to other process streams or convert it into electricity. The working fluid, circulating...... in the context of an industrial organic Rankine cycle, used for the recovery of waste heat from an engine of a marine container ship. The study illustrates that the model structure is vital for the uncertainties of equations of state and suggests that uncertainty becomes a criterion (along with e.g. goodness......-of-fit or ease of use) for the selection of an equation of state for a specific application. Furthermore, two studies on the identification of suitable working fluids for thermodynamic cycles are presented. The first one selects and assesses working fluid candidates for an organic Rankine cycle system to recover...
Ab Initio calculation of the vibrational spectrum and thermodynamic properties of rhombohedral P4O10
Rustad, James R.
2011-01-01
Plane-wave pseudopotential methods and density functional perturbation theory are used to calculate the phonon density of states and thermodynamic functions of h-P4O10. The calculated vibrational spectrum is in good agreement with the measured spectrum, but the calculations indicate some modifications in the interpretation of the spectrum, mainly suggesting changes in the number of components used to fit a few of the observed peaks. The calculated low-temperature heat capacity is in good agre...
Thermodynamic properties of the liquid Hg-Tl alloys determined from vapour pressure measurements
Directory of Open Access Journals (Sweden)
Gierlotka W.
2002-01-01
Full Text Available The partial vapour pressure of mercury over liquid Hg-Tl liquid solutions were determined in the temperature range from 450 to 700 K by direct vapour pressure measurements carried out with the quartz gauge. From the measured ln pHg vs. T relationships activities of mercury were determined. Using Redlich-Kister formulas logarithms of the activity coefficients were described with the following equations: From which all thermodynamic functions in the solutions can be derived.
Czech Academy of Sciences Publication Activity Database
Hemzalová, P.; Friák, Martin; Šob, Mojmír; Ma, D.; Udyansky, A.; Raabe, D.; Neugebauer, J.
2013-01-01
Roč. 88, č. 17 (2013), Art. no. 174103 ISSN 1098-0121 R&D Projects: GA ČR(CZ) GAP108/12/0311; GA ČR GD106/09/H035; GA AV ČR IAA100100920 Institutional support: RVO:68081723 Keywords : nitrides * ab initio * thermodynamics * elasticity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.664, year: 2013
Energy Technology Data Exchange (ETDEWEB)
Kumar, R. [Department of Physics, The New College, Chennai 600 014 (India); Jayakumar, S. [Department of Physics, R.K.M. Vivekananda College, Chennai 600 004 (India); Kannappan, V., E-mail: vkannappan@hotmail.com [Department of Chemistry, Presidency College, Chennai 600 005 (India)
2012-05-20
Highlights: Black-Right-Pointing-Pointer Ultrasonic scan is carried out on ternary systems of aromatic tertiary amine and three aryl ketones. Black-Right-Pointing-Pointer Formation of CT complexes is found between tertiary amine with aryl ketones. Black-Right-Pointing-Pointer Stability constant values are computed by ultrasonic and spectral methods are compared. Black-Right-Pointing-Pointer The trend in the 'K' suggests that substituents in ketones influence the stabilities of these complexes. Black-Right-Pointing-Pointer The thermodynamic parameters suggest CT interaction is exothermic and the complexes are thermodynamically stable. - The thermodynamic stability of complexes formed between N,N-dimethylaniline (DMANI) and three ketones, namely, acetophenone (ACP), 4-chloroactophenone (ClACP) and 4-methylacetophenone (MACP) in n-hexane is extensively investigated by spectral and ultrasonic methods. The ultrasound scan was carried out in the temperature range 208.15-313.15 K and at atmospheric pressure on solutions containing equimolar concentrations of components ranging from 0.025 to 0.2 M. The existence of solute-solute interactions has also been confirmed through electronic absorption spectra analyzed with Benesi-Hildebrand theory at 303.15 K. The stability constants of the donor-acceptor complexes determined both by spectroscopic and ultrasonic methods are comparable and follow similar trends. The trend in the formation constants is discussed with structures of the components. The thermodynamic behavior of the systems was explained through the computed values of the free energy ({Delta}G), enthalpy ({Delta}H) and entropy ({Delta}S) changes for complex formation are computed and discussed.
Crystal chemistry, Mössbauer spectroscopy, and thermodynamic properties of botryogen
Czech Academy of Sciences Publication Activity Database
Majzlan, J.; Plášil, Jakub; Dachs, E.; Benisek, A.; Bender Koch, CH.
2016-01-01
Roč. 193, č. 2 (2016), s. 147-159 ISSN 0077-7757 R&D Projects: GA MŠk LO1603 Grant - others:EU(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : botryogen * crystal-structure refinement * H atoms * Mössbauer spectroscopy * thermodynamic s * acid-mine drainage Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.811, year: 2016
International Nuclear Information System (INIS)
Kumar, R.; Jayakumar, S.; Kannappan, V.
2012-01-01
Highlights: ► Ultrasonic scan is carried out on ternary systems of aromatic tertiary amine and three aryl ketones. ► Formation of CT complexes is found between tertiary amine with aryl ketones. ► Stability constant values are computed by ultrasonic and spectral methods are compared. ► The trend in the ‘K’ suggests that substituents in ketones influence the stabilities of these complexes. ► The thermodynamic parameters suggest CT interaction is exothermic and the complexes are thermodynamically stable. - The thermodynamic stability of complexes formed between N,N-dimethylaniline (DMANI) and three ketones, namely, acetophenone (ACP), 4-chloroactophenone (ClACP) and 4-methylacetophenone (MACP) in n-hexane is extensively investigated by spectral and ultrasonic methods. The ultrasound scan was carried out in the temperature range 208.15–313.15 K and at atmospheric pressure on solutions containing equimolar concentrations of components ranging from 0.025 to 0.2 M. The existence of solute–solute interactions has also been confirmed through electronic absorption spectra analyzed with Benesi-Hildebrand theory at 303.15 K. The stability constants of the donor–acceptor complexes determined both by spectroscopic and ultrasonic methods are comparable and follow similar trends. The trend in the formation constants is discussed with structures of the components. The thermodynamic behavior of the systems was explained through the computed values of the free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) changes for complex formation are computed and discussed.
Kyoichi Tezuka; Tatsuhiko Taguchi; Saman Alavi; Amadeu K. Sum; Ryo Ohmura
2012-01-01
This paper report analyses of thermodynamic stability of structure-H clathrate hydrates formed with methane and large guest molecules in terms of their gas phase molecular sizes and molar masses for the selection of a large guest molecule providing better hydrate stability. We investigated the correlation among the gas phase molecular sizes, the molar masses of large molecule guest substances, and the equilibrium pressures. The results suggest that there exists a molecular-size value for the ...
A class of black holes in dRGT massive gravity and their thermodynamical properties
Energy Technology Data Exchange (ETDEWEB)
Ghosh, Suchant G. [Jamia Millia Islamia, Centre of Theoretical Physics, New Delhi (India); University of Kwazulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, Private Bag 54001, Durban (South Africa); Tannukij, Lunchakorn [Mahidol University, Department of Physics, Faculty of Science, Bangkok (Thailand); Wongjun, Pitayuth [Naresuan University, The Institute for Fundamental Study, Phitsanulok (Thailand); Ministry of Education, Thailand Center of Excellence in Physics, Bangkok (Thailand)
2016-03-15
We present an exact spherical black hole solution in de Rham, Gabadadze, and Tolley (dRGT) massive gravity for a generic choice of the parameters in the theory, and also discuss the thermodynamical and phase structure of the black hole in both the grand canonical and the canonical ensembles (for the charged case). It turns out that the dRGT black hole solution includes other known solutions to the Einstein field equations, such as the monopole-de Sitter-Schwarzschild solution with the coefficients of the third and fourth terms in the potential and the graviton mass in massive gravity naturally generates the cosmological constant and the global monopole term. Furthermore, we compute the mass, temperature and entropy of the dRGT black hole, and also perform thermodynamical stability analysis. It turns out that the presence of the graviton mass completely changes the black hole thermodynamics, and it can provide the Hawking-Page phase transition which also occurs for the charged black holes. Interestingly, the entropy of a black hole is barely affected and still obeys the standard area law. In particular, our results, in the limit m{sub g} → 0, reduced exactly to the results of general relativity. (orig.)
High temperature thermodynamic properties of the fission product compounds of cesium and rubidium
International Nuclear Information System (INIS)
Kohli, R.; Lacom, W.
1986-01-01
A variety of fission product chemical interactions occurs in the complex fuel/fission products/cladding system in a reactor fuel rod. Of these, the reactions of the chemically active, high yield, volatile fission products, cesium and rubidium, are of particular interest. To understand their chemistry, high temperature thermodynamic data are needed for various compounds of cesium and rubidium. An experimental research program has been initiated to obtain reliable thermodynamic data on various Cs and Rb compounds. To date, heat capacity measurements have been made on Cs and Rb chromates, molybdates, dichromate, dimolybdates and rubidium zirconate in the temperature range 300-800 K. In addition, measurements are currently in progress on Cs and Rb chalcogenides, halides, aluminates and silicates. The measured heat capacity data has been combined with published enthalpy and entropy values to obtain a complete set of thermodynamic functions for some of these compounds to 800 K. The data have been used to reanalyze the chemical state of irradiated UO 2 fuel and the chemistry of PCI failure of the cladding by halogen stress corrosion cracking of Zircaloy in Light Water Reactors (LWRs). (author)
A class of black holes in dRGT massive gravity and their thermodynamical properties
International Nuclear Information System (INIS)
Ghosh, Suchant G.; Tannukij, Lunchakorn; Wongjun, Pitayuth
2016-01-01
We present an exact spherical black hole solution in de Rham, Gabadadze, and Tolley (dRGT) massive gravity for a generic choice of the parameters in the theory, and also discuss the thermodynamical and phase structure of the black hole in both the grand canonical and the canonical ensembles (for the charged case). It turns out that the dRGT black hole solution includes other known solutions to the Einstein field equations, such as the monopole-de Sitter-Schwarzschild solution with the coefficients of the third and fourth terms in the potential and the graviton mass in massive gravity naturally generates the cosmological constant and the global monopole term. Furthermore, we compute the mass, temperature and entropy of the dRGT black hole, and also perform thermodynamical stability analysis. It turns out that the presence of the graviton mass completely changes the black hole thermodynamics, and it can provide the Hawking-Page phase transition which also occurs for the charged black holes. Interestingly, the entropy of a black hole is barely affected and still obeys the standard area law. In particular, our results, in the limit m g → 0, reduced exactly to the results of general relativity. (orig.)
Measuring Thermodynamic Properties of Metals and Alloys With Knudsen Effusion Mass Spectrometry
Copland, Evan H.; Jacobson, Nathan S.
2010-01-01
This report reviews Knudsen effusion mass spectrometry (KEMS) as it relates to thermodynamic measurements of metals and alloys. First, general aspects are reviewed, with emphasis on the Knudsen-cell vapor source and molecular beam formation, and mass spectrometry issues germane to this type of instrument are discussed briefly. The relationship between the vapor pressure inside the effusion cell and the measured ion intensity is the key to KEMS and is derived in detail. Then common methods used to determine thermodynamic quantities with KEMS are discussed. Enthalpies of vaporization, the fundamental measurement, are determined from the variation of relative partial pressure with temperature using the second-law method or by calculating a free energy of formation and subtracting the entropy contribution using the third-law method. For single-cell KEMS instruments, measurements can be used to determine the partial Gibbs free energy if the sensitivity factor remains constant over multiple experiments. The ion-current ratio method and dimer-monomer method are also viable in some systems. For a multiple-cell KEMS instrument, activities are obtained by direct comparison with a suitable component reference state or a secondary standard. Internal checks for correct instrument operation and general procedural guidelines also are discussed. Finally, general comments are made about future directions in measuring alloy thermodynamics with KEMS.
Czech Academy of Sciences Publication Activity Database
Hrubý, Jan; Pátek, Jaroslav; Duška, Michal
2014-01-01
Roč. 228, č. 2 (2014), s. 120-128 ISSN 0957-6509 R&D Projects: GA AV ČR IAA200760905; GA ČR(CZ) GAP101/11/1593; GA MŠk LG13056 Institutional support: RVO:61388998 Keywords : metastable steam * thermodynamic properties * computational fluid dynamics Subject RIV: BJ - Thermodynamics Impact factor: 0.645, year: 2014 http://pia.sagepub.com/content/228/2. toc
Directory of Open Access Journals (Sweden)
Mario Diaz
2016-12-01
Full Text Available We have analyzed the effects of different native membrane lipid composition on the thermodynamic properties of the Na+-K+-ATPase in different epithelia from the gilthead seabream Sparus aurata. Thermodynamic parameters of activation for the Na+-K+-ATPase, as well as contents of lipid classes and fatty acids from polar lipids were determined for gill epithelia and enterocytes isolated from pyloric caeca, anterior intestine and posterior intestine. Arrhenius analyses of control animals revealed differences in thermal discontinuity values (Td and activation energies determined at both sides of Td between intestinal and gill epithelia. Eyring plots disclosed important differences in enthalpy of activation (H‡ and entropy of activation (S‡ between enterocytes and branchial cells. Induction of n-3 LCPUFA deficiency dramatically altered membrane lipid composition in enterocytes, being the most dramatic changes the increase in 18:1n-9 (oleic acid and the reduction of n-3 LCPUFA (mainly DHA, docosahexaenoic acid. Strikingly, branchial cells were much more resistant to diet-induced lipid alterations than enterocytes, indicating the existence of potent lipostatic mechanisms preserving membrane lipid matrix in gill epithelia. Paralleling lipid alterations, values of Ea1, H‡ and S‡ for the Na+-K+-ATPase were all increased, while Td values vanished, in LCPUFA deficient enterocytes. In turn, Differences in thermodynamic parameters were highly correlated with specific changes in fatty acids, but not with individual lipid classes including cholesterol in vivo. Thus, Td was positively related to 18:1n-9 and negatively to DHA. Td, Ea1 and H‡ were exponentially related to DHA/18:1n-9 ratio. The exponential nature of these relationships highlights the strong impact of subtle changes in the contents of oleic acid and DHA in setting the thermodynamic properties of epithelial Na+-K+-ATPase in vivo. The effects are consistent with physical
Energy Technology Data Exchange (ETDEWEB)
Li, Xu; Jiang, Jian-Hong; Xiao, Sheng-Xiong [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan Province (China); Gu, Hui-Wen, E-mail: gruyclewee@hnu.edu.cn [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan Province (China); Li, Chuan-Hua; Ye, Li-Juan; Li, Xia; He, Du-Gui; Yao, Fei-Hong [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan Province (China); Li, Qiang-Guo, E-mail: liqiangguo@163.com [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan Province (China)
2014-01-10
Graphical abstract: A new single Valen Shiff base was synthesized and characterized. The thermodynamics properties of the Shiff base were investigated by microcalorimetry. In particular, the interaction between the synthetic Shiff base and BSA at four different temperatures has been investigated using fluorescence quenching method. - Highlights: • A new single Valen Shiff base was synthesized and characterized. • The thermodynamics properties of the Shiff base were investigated by microcalorimetry. • The interaction between the Shiff base and BSA has been investigated using fluorescence quenching method. - Abstract: A new Valen Shiff base (C{sub 22}H{sub 24}N{sub 4}O{sub 5}) was synthesized using equivalent moles of o-vanillin and trimethoprim. At 298.15 K, the standard molar enthalpy of formation of the new compound was estimated to be Δ{sub f}H{sub m}{sup Θ} [C{sub 22}H{sub 24}N{sub 4}O{sub 5}(s), 298.15 K] = −(696.92 ± 1.67) kJ mol{sup −1} by microcalorimetry. In particular, the interaction between the Shiff base and bovine serum albumin (BSA) has been investigated. It was proved that the fluorescence quenching of BSA by Shiff base is a result of the formation of a Shiff base-BSA complex. Quenching constants were determined using the Sterns–Volmer equation to provide a measurement of the binding site between Shiff base and BSA. The thermodynamic parameters ΔG, ΔH, and ΔS of the system at different temperatures were calculated. What is more, the distance r between donor (Trp. 213) and acceptor (Shiff base) was obtained. Finally, synchronous fluorescence spectroscopy data has suggested the association between Shiff base and BSA changed the molecular conformation of BSA.
International Nuclear Information System (INIS)
Li, Xu; Jiang, Jian-Hong; Xiao, Sheng-Xiong; Gu, Hui-Wen; Li, Chuan-Hua; Ye, Li-Juan; Li, Xia; He, Du-Gui; Yao, Fei-Hong; Li, Qiang-Guo
2014-01-01
Graphical abstract: A new single Valen Shiff base was synthesized and characterized. The thermodynamics properties of the Shiff base were investigated by microcalorimetry. In particular, the interaction between the synthetic Shiff base and BSA at four different temperatures has been investigated using fluorescence quenching method. - Highlights: • A new single Valen Shiff base was synthesized and characterized. • The thermodynamics properties of the Shiff base were investigated by microcalorimetry. • The interaction between the Shiff base and BSA has been investigated using fluorescence quenching method. - Abstract: A new Valen Shiff base (C 22 H 24 N 4 O 5 ) was synthesized using equivalent moles of o-vanillin and trimethoprim. At 298.15 K, the standard molar enthalpy of formation of the new compound was estimated to be Δ f H m Θ [C 22 H 24 N 4 O 5 (s), 298.15 K] = −(696.92 ± 1.67) kJ mol −1 by microcalorimetry. In particular, the interaction between the Shiff base and bovine serum albumin (BSA) has been investigated. It was proved that the fluorescence quenching of BSA by Shiff base is a result of the formation of a Shiff base-BSA complex. Quenching constants were determined using the Sterns–Volmer equation to provide a measurement of the binding site between Shiff base and BSA. The thermodynamic parameters ΔG, ΔH, and ΔS of the system at different temperatures were calculated. What is more, the distance r between donor (Trp. 213) and acceptor (Shiff base) was obtained. Finally, synchronous fluorescence spectroscopy data has suggested the association between Shiff base and BSA changed the molecular conformation of BSA
Ehteshami, Hossein; Korzhavyi, Pavel A.
2017-12-01
First-principles-based thermodynamic modeling of cubic α and β phases of Mn represent a challenge due to their structural complexity and the necessity of simultaneous treatment of several types of disorder (electronic, magnetic, and vibrational) that have very different characteristic time scales. Here we employ mean-field theoretical models to describe the different types of disorder and then we connect each layer of theory to the others using the adiabatic principle of separating faster and slower degrees of freedom. The slowest (vibrational) degrees of freedom are treated using the Moruzzi, Janak, and Schwarz formalism [Phys. Rev. B 37, 790 (1988), 10.1103/PhysRevB.37.790] of the Debye-Grüneisen model parametrized based on the first-principles calculated equation of state which includes the free-energy contributions due to the fast (electronic and magnetic) degrees of freedom via the Fermi-Dirac distribution function and a mean-field theory of transverse spin fluctuations. The magnetic contribution due to transverse spin fluctuations has been computed self-consistently within the disordered local moment picture of the paramagnetic state. The obtained results for thermodynamic properties such as lattice parameter, linear thermal expansion coefficient, and heat capacity of both phases show a good agreement with available experimental data. We also tested the assumption about the nature (localized versus delocalized) of magnetic moment on site IV in α -Mn and site I in β -Mn on the thermodynamic properties of these two phases. Similar to the findings of experimental studies, we conclude that magnetic moment on site IV in α -Mn is not of a localized character. However, a similar analysis suggests that the magnetic moment of site I in β -Mn should be treated as localized.
Gering, Kevin Leslie
A molecular formulation based on modern liquid state theory is applied to the properties and phase behavior of electrolyte systems containing volatile species. An electrolyte model based on the exponential modification of the Mean Spherical Approximation (EXP-MSA) is used to describe the cation-cation, cation-anion, and anion-anion distributions of the ionic species. This theory represents an improvement over the nonmodified MSA approach, and goes beyond the usual Debye-Huckel theory and Pitzer correlation for treating concentrated solutions. Electrolyte solutions such as water-salt, ammonia-salt, mixed salts, and mixed -solvent systems are investigated over a wide range of temperatures, pressures, and compositions. The usual salt properties, such as osmotic and mean activity coefficients and other thermodynamic properties (enthalpies), are calculated. The predictions are accurate to saturation limits. In addition, an iterative method is presented that is used to predict vapor-liquid equilibria (VLE) and thermodynamic properties of single-salt multisolvent electrolytes of the form solvent-cosolvent-salt. In this method, a local composition model (LCM) and EXP-MSA theory are combined with traditional phase equilibria relations to estimate the pressures and compositions of a vapor phase in equilibrium with a binary-solvent electrolyte. Also, a pseudo-solvent model is proposed as a means of obtaining a variety of averaged liquid phase electrolyte properties. To predict preferential solvation in mixed solvents, a general framework is developed that is based on predicted solvation numbers of each solvent. Preferential solvation will be shown to influence VLE. Results show that phase equilibria is accurately predicted by the above iterative method. Three mixed-solvent electrolyte systems are investigated: water -ethylene glycol-LiBr, ammonia-water-LiBr, and methanol -water-LiCl. Finally, the above electrolyte model is utilized in predicting design criteria for a single
Thermodynamic Database for Zirconium Alloys
International Nuclear Information System (INIS)
Jerlerud Perez, Rosa
2003-05-01
For many decades zirconium alloys have been commonly used in the nuclear power industry as fuel cladding material. Besides their good corrosion resistance and acceptable mechanical properties the main reason of using these alloys is the low neutron absorption. Zirconium alloys are exposed to a very severe environment during the nuclear fission process and there is a demand for better design of this material. To meet this requirement a thermodynamic database is developed to support material designers. In this thesis some aspects about the development of a thermodynamic database for zirconium alloys are presented. A thermodynamic database represents an important facility in applying thermodynamic equilibrium calculations for a given material providing: 1) relevant information about the thermodynamic properties of the alloys e.g. enthalpies, activities, heat capacity, and 2) significant information for the manufacturing process e.g. heat treatment temperature. The basic information in the database is first the unary data, i.e. pure elements; those are taken from the compilation of the Scientific Group Thermodata Europe (SGTE) and then the binary and ternary systems. All phases present in those binary and ternary systems are described by means of the Gibbs energy dependence on composition and temperature. Many of those binary systems have been taken from published or unpublished works and others have been assessed in the present work. All the calculations have been made using Thermo C alc software and the representation of the Gibbs energy obtained by applying Calphad technique
DEFF Research Database (Denmark)
Westerhoff, Hans V.; Jensen, Peter Ruhdal; Snoep, Jacky L.
1998-01-01
Thermodynamics has always been a remarkable science in that it studies macroscopic properties that are only partially determined by the properties of individual molecules. Entropy and free energy only exist in constellations of more than a single molecule (degree of freedom). They are the so...... understanding of this BioComplexity, modem thermodynamic concepts and methods (nonequilibrium thermodynamics, metabolic and hierarchical control analysis) will be needed. We shall propose to redefine nonequilibrium thermodynamics as: The science that aims at understanding the behaviour of nonequilibrium systems...... by taking into account both the molecular properties and the emergent properties that are due to (dys)organisation. This redefinition will free nonequilibrium thermodynamics from the limitations imposed by earlier near-equilibrium assumptions, resolve the duality with kinetics, and bridge the apparent gap...
Phenanthrene sorption to Chinese coal: Importance of coal's geochemical properties
International Nuclear Information System (INIS)
Yan Caixia; Yang Yi; Liu Min; Nie Minghua; Zhou, John L.
2011-01-01
Highlights: → Phen was chosen as the probe compound for determining the sorption of PAHs to a series of different Chinese coal samples. → The combined partition and adsorption model yielded a better fit than the Freundlich isotherm. → Compared to total carbon, BC might play more important role in the sorption of Phen to coal samples. → Relationships between aromatic and aliphatic carbon contents and sorption parameters indicated the significance of aromatic and aliphatic carbon in the coal sorption behavior. - Abstract: Phenanthrene (Phen) was chosen as the probe compound for determining the sorption of PAHs to a series of different coal samples from China. Based on elemental analysis and nuclear magnetic resonance (NMR) spectra analysis, coal samples were characterized with different metamorphic evolutional degrees. The experimental sorption data were fitted well by the Freundlich model, suggesting enhanced sorption capacity and strong nonlinearity of coal samples. The combined partition and adsorption model yielded a better fit than the Freundlich isotherm, indicating that adsorption dominated the sorption at low aqueous concentrations. Correlations between coal properties and sorption capacity values indicated that C%, H/C and O/C atomic ratios were the key factors controlling the sorption behavior. Compared to total carbon, BC might play more important role in the sorption of Phen to coal samples. Moreover, there existed nonlinear relationships between combined carbon, aromatic and aliphatic carbon contents and log K Fr and n values, respectively, indicating the significance of aromatic and aliphatic carbon in the coal sorption behavior.
Oumelaz, F.; Nemiri, O.; Boumaza, A.; Ghemid, S.; Meradji, H.; Bin Omran, S.; El Haj Hassan, F.; Rai, D. P.; Khenata, R.
2017-12-01
In this theoretical study, we have investigated the structural, phase transition, electronic, thermodynamic and optical properties of GaPxSb1-x ternary alloys. Our calculations are performed with the WIEN2k code based on density functional theory using the full-potential linearized augmented plane wave method. For the electron exchange-correlation potential, a generalized gradient approximation within Wu-Cohen scheme is considered. The recently developed Tran-Blaha modified Becke-Johnson potential has also been used to improve the underestimated band gap. The structural properties, including the lattice constants, the bulk moduli and their pressure derivatives are in very good agreement with the available experimental data and theoretical results. Several structural phase transitions were studied here to establish the stable structure and to predict the phase transition under hydrostatic pressure. The computed transition pressure (Pt) of the material of our interest from the zinc blende (B3) to the rock salt (B1) phase has been determined and found to agree well with the experimental and theoretical data. The calculated band structure shows that GaSb binary compound and the ternary alloys are direct band gap semiconductors. Optical parameters such as the dielectric constants and the refractive indices are calculated and analyzed. The thermodynamic results are also interpreted and analyzed.
Sutton, K.
1981-01-01
Thermodynamic and transport properties of gaseous CF4 that can be used in flow field computer codes and theoretical analyses for comparison of results with experimental data from the Langley Hypersonic CF4 Tunnel are presented. The thermodynamic relations which are based on thermally perfect but calorifically imperfect gas are adequate for the testing environment of the CF4 tunnel and are simpler to use than the imperfect gas relations required to define the complete expansion from the tunnel reservoir. Relations for the transport properties are based on the kinetic theory of gases in which published experimental data are used in the derivation of the relations. Extensive experimental data were located for viscosity and the derived relation should provide values for viscosity with errors of less than 1 percent. The experimental data for thermal conductivity were limited with significant disagreement between the various sources. The derived relation will probably provide values for the thermal conductivity with errors of no more than 5 percent which is within the accuracy of the experimental data.
Shu, Min; Zhu, Liang; Wang, Yan-fei; Yang, Jing; Wang, Liyu; Yang, Libin; Zhao, Xiaoyu; Du, Wei
2018-01-01
The solubility and dissolution thermodynamic properties of raspberry ketone in a set of binary solvent mixtures (ethanol + water) with different compositions were experimentally determined by static gravimetrical method in the temperature range of 283.15-313.15 K at 0.10 MPa. The solubility of raspberry ketone in this series of ethanol/water binary solvent mixtures was found to increase with a rise in temperature and the rising mole fraction of ethanol in binary solvent mixtures. The van't Hoff, modified Apelblat and 3D Jouyban-Acree-van't Hoff equations were increasingly applied to correlate the solubility in ethanol/water binary solvent mixtures. The former two models could reach better fitting results with the solubility data, while the 3D model can be comprehensively used to estimate the solubility data in all the ratios of ethanol and water in binary solvent mixtures at random temperature. Furthermore, the changes of dissolution thermodynamic properties of raspberry ketone in experimental ethanol/water solvent mixtures were obtained by van't Hoff equation. For all the above experiments, these dissolution processes of raspberry ketone in experimental ethanol/water binary solvent mixtures were estimated to be endothermic and enthalpy-driven.
Experimental thermodynamics experimental thermodynamics of non-reacting fluids
Neindre, B Le
2013-01-01
Experimental Thermodynamics, Volume II: Experimental Thermodynamics of Non-reacting Fluids focuses on experimental methods and procedures in the study of thermophysical properties of fluids. The selection first offers information on methods used in measuring thermodynamic properties and tests, including physical quantities and symbols for physical quantities, thermodynamic definitions, and definition of activities and related quantities. The text also describes reference materials for thermometric fixed points, temperature measurement under pressures, and pressure measurements. The publicatio
Shugurov, S M; Kurapova, O Yu; Lopatin, S I; Konakov, V G; Vasil'eva, E A
2017-12-15
Zirconia doped with a lanthanum oxide system is of high interest due to its exceptional thermal stability for the development of high-performance ceramics. It possesses the beneficial properties of pure zirconia, such as heat resistance, mechanical strength and inertness, but also eliminates its main disadvantage, i.e. brittleness. At high temperatures, components of such systems may vaporize selectively, leading to significant change in composition, and hence, the thermal resistance, phase stability and performance of the ceramic materials. Therefore, information on the vaporization processes and thermodynamic properties of the La 2 O 3 -ZrO 2 system is of great importance. Knudsen effusion mass spectrometry was used to study the vaporization processes and thermodynamic properties of solid solutions in the La 2 O 3 -ZrO 2 system at 2110 K. Pure La 2 O 3 was used as a reference substance. Comprehensive characterization of the precursors and ceramics was performed via SEM, STA, XRD and PSD analysis. Zirconia-doped lanthania precursor powders and ceramics with La 2 O 3 of 33.3, 50, 70 and 90 mol.% content were manufactured by solid-state synthesis and the original cryochemical technique. La, LaO, ZrO and ZrO 2 were found to be the main vapor species over the samples studied. The activities and thermodynamic properties of La 2 O 3 were calculated. Via XRD analysis it was shown that the phase composition of xLa 2 O 3 -(100-x)ZrO 2 powders (x = 0.33, 0.5, 0.7 and 0.9 mol. fraction) significantly depends on the synthesis technique chosen. According to the XRD results combined with Rietveld refinement of the patterns, 33.3 La 2 O 3 -66.7 ZrO 2 ceramics after solid-state synthesis are composed of well-formed cubic pyrochlore-type La 2 Zr 2 O 7 with 5 wt.% admixture of monoclinic and cubic ZrO 2 whereas 33.3 La 2 O 3 -66.7 ZrO 2 precursor powders after cryochemical synthesis correspond to low-crystalline La(OH) 3 . The components of the La 2 O 3 -ZrO 2 system evaporate
DEFF Research Database (Denmark)
Ruszczynski, Lukasz; Zubov, Alexandr; Sin, Gürkan
2017-01-01
This study presents methods for prediction of thermodynamic properties required in development of models for drug skin permeation processes, such as drug solubilities and partition coefficients. For evaluation of these properties, ab initio models such as COSMO-SAC can assist in providing a therm...
Filanovich, A. N.; Povzner, A. A.
2017-12-01
In the framework of density functional theory method, the ground state energy of the PuCoGa5 compound is calculated for different values of the unit cell volume. The obtained data were incorporated into the thermodynamic model, which was utilized to calculate the temperature dependencies of thermal and elastic properties of PuCoGa5. The parameters of the developed model were estimated based on data of ab initio phonon spectrum. The Gruneisen parameters, which characterize degree of anharmonicity of the acoustic and optical phonons, are obtained. Using experimental data, non-lattice contributions to the coefficient of thermal expansion and heat capacity are determined. The nature of observed anomalies of the properties of PuCoGa5 is discussed, in particular, the possibility of a valence phase transition.
International Nuclear Information System (INIS)
Borderie, B.; Gulminelli, F.; Rivet, M.F.; Dore, D.; Tassan-Got, L.; Bacri, Ch.O.; Ouatizerga, A.; Plagnol, E.; Squalli, M.; Chbihi, A.; Auger, G.; Benlliure, J.; Ecomard, P.; Le Fevre, A.; Marie, N.; Rosato, E.; Saint-Laurent, F.; Wieleczko, J.P.; Durand, D.; Bougault, R.; Brou, R.; Colin, J.; Cussol, D.; Laforest, R.; Lecolley, J.F.; Lefort, T.; Lopez, O.; Louvel, M.; Metivier, V.; Peter, J.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Parlog, M.; Bisquer, E.; Demeyer, A.; Guinet, D.; Lautesse, P.; Lebreton, L.; Charvet, J.L.; Dayras, R.; De Filippo, E.; Legrain, R.; Nalpas, L.; Volant, C.; Eudes, Ph.; Gourio, D.; Laville, J.L.; Rahmani, A.; Reposeur, T.
1997-01-01
Vaporization events, where all species have atomic numbers lower than 3, and deexcitation properties of quasi-projectiles involved in binary dissipative collisions between 36 Ar and 58 Ni are studied with the multidetector INDRA. Kinematical properties and chemical composition (mean values and variances) of vaporizing sources are derived over the excitation energy per nucleon range 8-28 MeV. These data are found in good agreement with the results of a model describing a gas of fermions and bosons in thermal and chemical equilibrium, which strongly suggests that thermodynamical equilibrium has been reached even for such sources produced in very extreme conditions of collisions. Finally, removing the constraint on atomic numbers lower than 3, the evolution of the chemical composition of quasi-projectiles is presented over the excitation energy range 0-25 AMeV. (authors)
Energy Technology Data Exchange (ETDEWEB)
Coban, Cansu [Balikesir Univ. (Turkey). Dept. of Physics
2017-07-01
The pressure dependent behaviour of the structural, electronic, mechanical, vibrational, and thermodynamic properties of Pd{sub 2}TiX (X=Ga, In) Heusler alloys was investigated by ab initio calculations. The lattice constant, the bulk modulus and its first pressure derivative, the electronic band structure and the density of states (DOS), mechanical properties such as elastic constants, anisotropy factor, Young's modulus, etc., the phonon dispersion curves and phonon DOS, entropy, heat capacity, and free energy were obtained under pressure. It was determined that the calculated lattice parameters are in good agreement with the literature, the elastic constants obey the stability criterion, and the phonon dispersion curves have no negative frequency which shows that the compounds are stable. The band structures at 0, 50, and 70 GPa showed valence instability at the L point which explains the superconductivity in Pd{sub 2}TiX (X=Ga, In).
Thermodynamic estimation: Ionic materials
International Nuclear Information System (INIS)
Glasser, Leslie
2013-01-01
Thermodynamics establishes equilibrium relations among thermodynamic parameters (“properties”) and delineates the effects of variation of the thermodynamic functions (typically temperature and pressure) on those parameters. However, classical thermodynamics does not provide values for the necessary thermodynamic properties, which must be established by extra-thermodynamic means such as experiment, theoretical calculation, or empirical estimation. While many values may be found in the numerous collected tables in the literature, these are necessarily incomplete because either the experimental measurements have not been made or the materials may be hypothetical. The current paper presents a number of simple and relible estimation methods for thermodynamic properties, principally for ionic materials. The results may also be used as a check for obvious errors in published values. The estimation methods described are typically based on addition of properties of individual ions, or sums of properties of neutral ion groups (such as “double” salts, in the Simple Salt Approximation), or based upon correlations such as with formula unit volumes (Volume-Based Thermodynamics). - Graphical abstract: Thermodynamic properties of ionic materials may be readily estimated by summation of the properties of individual ions, by summation of the properties of ‘double salts’, and by correlation with formula volume. Such estimates may fill gaps in the literature, and may also be used as checks of published values. This simplicity arises from exploitation of the fact that repulsive energy terms are of short range and very similar across materials, while coulombic interactions provide a very large component of the attractive energy in ionic systems. Display Omitted - Highlights: • Estimation methods for thermodynamic properties of ionic materials are introduced. • Methods are based on summation of single ions, multiple salts, and correlations. • Heat capacity, entropy
Neighborhood properties are important determinants of temperature sensitive mutations.
Directory of Open Access Journals (Sweden)
Svetlana Lockwood
Full Text Available Temperature-sensitive (TS mutants are powerful tools to study gene function in vivo. These mutants exhibit wild-type activity at permissive temperatures and reduced activity at restrictive temperatures. Although random mutagenesis can be used to generate TS mutants, the procedure is laborious and unfeasible in multicellular organisms. Further, the underlying molecular mechanisms of the TS phenotype are poorly understood. To elucidate TS mechanisms, we used a machine learning method-logistic regression-to investigate a large number of sequence and structure features. We developed and tested 133 features, describing properties of either the mutation site or the mutation site neighborhood. We defined three types of neighborhood using sequence distance, Euclidean distance, and topological distance. We discovered that neighborhood features outperformed mutation site features in predicting TS mutations. The most predictive features suggest that TS mutations tend to occur at buried and rigid residues, and are located at conserved protein domains. The environment of a buried residue often determines the overall structural stability of a protein, thus may lead to reversible activity change upon temperature switch. We developed TS prediction models based on logistic regression and the Lasso regularized procedure. Through a ten-fold cross-validation, we obtained the area under the curve of 0.91 for the model using both sequence and structure features. Testing on independent datasets suggested that the model predicted TS mutations with a 50% precision. In summary, our study elucidated the molecular basis of TS mutants and suggested the importance of neighborhood properties in determining TS mutations. We further developed models to predict TS mutations derived from single amino acid substitutions. In this way, TS mutants can be efficiently obtained through experimentally introducing the predicted mutations.
Thermodynamics Far from the Thermodynamic Limit.
de Miguel, Rodrigo; Rubí, J Miguel
2017-11-16
Understanding how small systems exchange energy with a heat bath is important to describe how their unique properties can be affected by the environment. In this contribution, we apply Landsberg's theory of temperature-dependent energy levels to describe the progressive thermalization of small systems as their spectrum is perturbed by a heat bath. We propose a mechanism whereby the small system undergoes a discrete series of excitations and isentropic spectrum adjustments leading to a final state of thermal equilibrium. This produces standard thermodynamic results without invoking system size. The thermal relaxation of a single harmonic oscillator is analyzed as a model example of a system with a quantized spectrum than can be embedded in a thermal environment. A description of how the thermal environment affects the spectrum of a small system can be the first step in using environmental factors, such as temperature, as parameters in the design and operation of nanosystem properties.
2017-01-01
RNA Polymerase II pauses and backtracks during transcription, with many consequences for gene expression and cellular physiology. Here, we show that the energy required to melt double-stranded nucleic acids in the transcription bubble predicts pausing in Saccharomyces cerevisiae far more accurately than nucleosome roadblocks do. In addition, the same energy difference also determines when the RNA polymerase backtracks instead of continuing to move forward. This data-driven model corroborates—in a genome wide and quantitative manner—previous evidence that sequence-dependent thermodynamic features of nucleic acids influence both transcriptional pausing and backtracking. PMID:28301878
Thermodynamic properties of a spin-1 model with long-range interactions
Hou, Ji-Xuan; Yu, Xu-Chen
2018-02-01
The long-range interacting spin-1 chain placed in a staggered magnetic field is studied by means of microcanonical approach. Firstly, we study the microcanonical entropy of the system in the thermodynamic limit and find the system is non-ergodic and can exhibit either first-order phase transition or second-order phase transition by shifting the external magnetic field strength. Secondly, we construct the global phase diagram of the system and find a phase transition area in the phase diagram corresponding to the temperature jump of the first-order phase transition.
Energy Technology Data Exchange (ETDEWEB)
Perrot, P. [Lille-1 Univ., Lab. de Metallurgie Physique, UMR CNRS 8517, 59 - Villeneuve-d' Ascq (France)
2005-10-01
This article presents, in the form of tables, the thermodynamic data necessary for the calculation of equilibrium constants of reactions between mineral compounds (Rb, Re, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Tc, Te, Th, Ti, Tl, Tm, U, V, W, Xe, Y, Yb, Zn, and Zr compounds). Table 1 presents the data recommended by Codata; table 2 gives the minimum informations allowing the calculation of an equilibrium constant in first approximation; table 3 allows to take into consideration the thermal capacities. Finally, table 4 gathers the data relative to species in aqueous solution. (J.S.)
The thermodynamic properties of Fe(II) complexes with 1,2,4-triazoles
Berezovskii, G. A.; Pishchur, D. P.; Shakirova, O. G.; Lavrenova, L. G.
2009-11-01
The temperature dependences of the heat capacities at 106-330 K of the monoligand Fe(NH2trz)3I2 ( I) and mixed-ligand Fe(Htrz)0.3(NH2trz)2.7SiF6 · H2O ( II) complexes (Htrz is 1,2,4-triazole, and NH2trz is 4-amino-1,2,4-triazole) were studied by adiabatic vacuum calorimetry. The 1A1 ⇔ 5T2 spin transition was observed in these compounds. The thermodynamic parameters of phase transitions in I and II were determined.
Energy Technology Data Exchange (ETDEWEB)
Deo, Chaitanya; Adnersson, Davis; Battaile, Corbett; uberuaga, Blas
2012-10-30
The team will examine how the incorporation of actinide species important for mixed oxide (MOX) and other advanced fuel designs impacts thermodynamic quantities of the host UO{sub 2} nuclear fuel and how Pu, Np, Cm and Am influence oxygen mobility. In many cases, the experimental data is either insufficient or missing. For example, in the case of pure NpO2, there is essentially no experimental data on the hyperstoichiometric form it is not even known if hyperstoichiometry NpO{sub 2{+-}x} is stable. The team will employ atomistic modeling tools to calculate these quantities
Ben-Naim, Arieh
1987-01-01
This book deals with a subject that has been studied since the beginning of physical chemistry. Despite the thousands of articles and scores of books devoted to solvation thermodynamics, I feel that some fundamen tal and well-established concepts underlying the traditional approach to this subject are not satisfactory and need revision. The main reason for this need is that solvation thermodynamics has traditionally been treated in the context of classical (macroscopic) ther modynamics alone. However, solvation is inherently a molecular pro cess, dependent upon local rather than macroscopic properties of the system. Therefore, the starting point should be based on statistical mechanical methods. For many years it has been believed that certain thermodynamic quantities, such as the standard free energy (or enthalpy or entropy) of solution, may be used as measures of the corresponding functions of solvation of a given solute in a given solvent. I first challenged this notion in a paper published in 1978 b...
Kaufman, Myron
2002-01-01
Ideal for one- or two-semester courses that assume elementary knowledge of calculus, This text presents the fundamental concepts of thermodynamics and applies these to problems dealing with properties of materials, phase transformations, chemical reactions, solutions and surfaces. The author utilizes principles of statistical mechanics to illustrate key concepts from a microscopic perspective, as well as develop equations of kinetic theory. The book provides end-of-chapter question and problem sets, some using Mathcad™ and Mathematica™; a useful glossary containing important symbols, definitions, and units; and appendices covering multivariable calculus and valuable numerical methods.
Barney, Rebecca; Nourgaliev, Robert; Delplanque, Jean-Pierre; McCallen, Rose
2017-11-01
Heat transfer is quantified and contrasted for the Poiseuille flow of a fluid at both subcritical and supercritical thermodynamic conditions in a circular pipe subject to a uniform wall heat flux. The conditions considered are relevant to Supercritical Water Reactor (SCWR) applications. In the supercritical thermodynamic regime, a fluid can exhibit large density variations of density, thermal conductivity, and viscosity, which will affect flow and heat transfer characteristics significantly. An advanced equation of state for supercritical water was implemented in a 2D and 3D Arbitrary Lagrangian-Eurlerian multi-physics simulation tool called ALE3D developed at Lawrence Livermore National Laboratory. A newly developed, robust, high-order in space and time, fully implicit reconstructed discontinuous Galerkin (rDG) method is used to enable the numerical simulation of convective heat transfer with supercritical water. Results demonstrate the capability of this approach to accurately capture the non-linear behavior and enhanced heat transfer with supercritical water. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Information management release number LLNL-ABS-736004. Work is supported by the Integrated University Program Graduate Fellowship. Opinions, findings, conclusions or recommendations expressed are of the authors and do not necessarily reflect the views of DOE office of NE.
Thermodynamic DFT analysis of natural gas.
Neto, Abel F G; Huda, Muhammad N; Marques, Francisco C; Borges, Rosivaldo S; Neto, Antonio M J C
2017-08-01
Density functional theory was performed for thermodynamic predictions on natural gas, whose B3LYP/6-311++G(d,p), B3LYP/6-31+G(d), CBS-QB3, G3, and G4 methods were applied. Additionally, we carried out thermodynamic predictions using G3/G4 averaged. The calculations were performed for each major component of seven kinds of natural gas and to their respective air + natural gas mixtures at a thermal equilibrium between room temperature and the initial temperature of a combustion chamber during the injection stage. The following thermodynamic properties were obtained: internal energy, enthalpy, Gibbs free energy and entropy, which enabled us to investigate the thermal resistance of fuels. Also, we estimated an important parameter, namely, the specific heat ratio of each natural gas; this allowed us to compare the results with the empirical functions of these parameters, where the B3LYP/6-311++G(d,p) and G3/G4 methods showed better agreements. In addition, relevant information on the thermal and mechanic resistance of natural gases were investigated, as well as the standard thermodynamic properties for the combustion of natural gas. Thus, we show that density functional theory can be useful for predicting the thermodynamic properties of natural gas, enabling the production of more efficient compositions for the investigated fuels. Graphical abstract Investigation of the thermodynamic properties of natural gas through the canonical ensemble model and the density functional theory.
Erum, Nazia; Azhar Iqbal, Muhammad
2017-12-01
The effect of pressure variation on structural, electronic, elastic, mechanical, optical and thermodynamic characteristics of cubic SrNaF3 fluoroperovskite have been investigated by employing first-principles method within the framework of gradient approximation (GGA). For the total energy calculations, we have used the full-potential linearized augmented plane wave (FP-LAPW) method. Thermodynamic properties are computed in terms of quasi-harmonic Debye model. The pressure effects are determined in the range of 0–25 GPa, in which mechanical stability of SrNaF3 fluoroperovskite remains valid. A prominent decrease in lattice constant and bonds length is observed with the increase in pressure from 0 to 25 GPa. The effect of increase in pressure on band structure calculations with GGA and GGA plus Tran–Blaha modified Becke–Johnson (TB-mBJ) potential reveals a predominant characteristic associated with widening of bandgap. The influence of pressure on set of isotropic elastic parameters and their related properties are numerically estimated for SrNaF3 polycrystalline aggregate. Apart of linear dependence of elastic coefficients, transition from brittle to ductile behavior is observed as pressure is increased from 0 to 25 GPa. We have successfully obtained variation of lattice constant, volume expansion, bulk modulus, Debye temperature and specific heat capacities with pressure and temperature in the range of 0–25 GPa and 0–600 K. All the calculated optical properties such as the complex dielectric function ε(ω), optical conductivity σ(ω), energy loss function L(ω), absorption coefficient α(w), refractive index n(ω), reflectivity R(ω), and effective number of electrons n eff, via sum rules shift towards the higher energies under the application of pressure.
Energy Technology Data Exchange (ETDEWEB)
Masuda-Jindo, K. [Department of Materials Science and Engineering, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8503 (Japan)], E-mail: kmjindo@issp.u-tokyo.ac.jp; Vu Van Hung; Hoa, N.T. [Department of Physics, Hanoi National Pedagogic University, km8 Hanoi-Sontay Highway, Hanoi (Viet Nam); Turchi, P.E.A. [Lawrence Livermore National Laboratory, PO Box 808, L-353 LLNL, Livermore, CA 94551 (United States)
2008-03-06
The thermodynamic quantities of high temperature metals and alloys are studied using the statistical moment method, going beyond the quasi-harmonic approximations. Including the power moments of the atomic displacements up to the fourth order, the Helmholtz free energies and the related thermodynamic quantities are derived explicitly in closed analytic forms. The configurational entropy term is taken into account by using the tetrahedron cluster approximation of the cluster variation method (CVM). The energetics of the binary (Ta-W and Mo-Ta) alloys are treated within the framework of the first-principles TB-LMTO (tight-binding linear muffin tin orbital) method coupled to CPA (coherent potential approximation) and GPM (generalized perturbation method). The equilibrium phase diagrams are calculated for the refractory Ta-W and Mo-Ta bcc alloys. In addition, the mechanical properties, i.e., temperature dependence of the elastic moduli C{sub 11}, C{sub 12} and C{sub 44} and those of the ideal tensile and shear strengths of the bcc Ta-W and Ta-Mo alloys have been also studied.
Hendricks, R. C.
1994-01-01
A computer program, GASP, has been written to calculate the thermodynamic and transport properties of argon, carbon dioxide, carbon monoxide, fluorine, methane, neon, nitrogen, and oxygen. GASP accepts any two of pressure, temperature, or density as input. In addition, entropy and enthalpy are possible inputs. Outputs are temperature, density, pressure, entropy, enthalpy, specific heats, expansion coefficient, sonic velocity, viscosity, thermal conductivity, and surface tension. A special technique is provided to estimate the thermal conductivity near the thermodynamic critical point. GASP is a group of FORTRAN subroutines. The user typically would write a main program that invoked GASP to provide only the described outputs. Subroutines are structured so that the user may call only those subroutines needed for his particular calculations. Allowable pressures range from 0.l atmosphere to 100 to l,000 atmospheres, depending on the fluid. Similarly, allowable pressures range from the triple point of each substance to 300 degrees K to 2000 degrees K, depending on the substance. The GASP package was developed to be used with heat transfer and fluid flow applications. It is particularly useful in applications of cryogenic fluids. Some problems associated with the liquefication, storage, and gasification of liquefied natural gas and liquefied petroleum gas can also be studied using GASP. This program is written in FORTRAN IV for batch execution and is available for implementation on IBM 7000 series computers. GASP was developed in 1971.
Thermodynamics of nuclear materials
International Nuclear Information System (INIS)
Rand, M.H.
1975-01-01
A report is presented of the Fourth International Symposium on Thermodynamics of Nuclear Materials held in Vienna, 21-25 October 1974. The technological theme of the Symposium was the application of thermodynamics to the understanding of the chemistry of irradiated nuclear fuels and to safety assessments for hypothetical accident conditions in reactors. The first four sessions were devoted to these topics and they were followed by four more sessions on the more basic thermodynamics, phase diagrams and the thermodynamic properties of a wide range of nuclear materials. Sixty-seven papers were presented
Energy Technology Data Exchange (ETDEWEB)
Crowley, M. F.; Matthews, J.; Beckham, G.; Bomble, Y.; Hynninen, A. P.; Ciesielski, P. F.
2012-01-01
Cellulose is still a mysterious polymer in many ways: structure of microfibrils, thermodynamics of synthesis and degradation, and interactions with other plant cell wall components. Our aim is to uncover the details and mechanisms of cellulose digestion and synthesis. We report the details of the structure of cellulose 1-beta under several temperature conditions and report here the results of these studies and connections to experimental measurements and the measurement in-silico the free energy of decrystallization of several morphologies of cellulose. In spatially large modeling, we show the most recent work of mapping atomistic and coarse-grain models into tomographic images of cellulose and extreme coarse-grain modeling of interactions of large cellulase complexes with microfibrils. We discuss the difficulties of modeling cellulose and suggest future work both experimental and theoretical to increase our understanding of cellulose and our ability to use it as a raw material for fuels and materials.
Thermodynamic Properties of Hydrogen + Tetra-n-Butyl Ammonium Bromide Semi-Clathrate Hydrate
Directory of Open Access Journals (Sweden)
Shunsuke Hashimoto
2010-01-01
Full Text Available Thermodynamic stability and hydrogen occupancy on the hydrogen + tetra-n-butyl ammonium bromide semi-clathrate hydrate were investigated by means of Raman spectroscopic and phase equilibrium measurements under the three-phase equilibrium condition. The structure of mixed gas hydrates changes from tetragonal to another structure around 95 MPa and 292 K depending on surrounding hydrogen fugacity. The occupied amount of hydrogen in the semi-clathrate hydrate increases significantly associated with the structural transition. Tetra-n-butyl ammonium bromide semi-clathrate hydrates can absorb hydrogen molecules by a pressure-swing without destroying the hydrogen bonds of hydrate cages at 15 MPa or over.
Impact of Aerosols and Atmospheric Thermodynamics on Cloud Properties within the Climate System
Matsui, Toshihisa; Masunaga, Hirohiko; Pielke, Roger, Sr.; Tao, Wei-Kuo
2003-01-01
A combination of cloud-top and columnar droplet sizes derived from the multi Tropical Rainfall Measurement Mission (TRMM) sensors reveals the sensitivity of the aerosols effect on cloud-precipitation process due to environmental vertical thermodynamic structure. First, the magnitude of aerosol indirect effect could be larger with the analysis of columnar droplet sizes than that derived from the cloud-top droplet sizes, since column-droplet size can account for the broader droplet spectra in the cloud layers. Second, a combination of cloud- top and columnar droplet sizes reveals that the warm rain process is prevented regardless of the aerosols concentration under a high static stability such as when a strong temperature inversion exists, while a high aerosol concentration suppresses the warm rain formulation under a low static stability.
Thermodynamic properties and neutron diffraction studies of silver ferrite AgFeO2
Vasiliev, A.; Volkova, O.; Presniakov, I.; Baranov, A.; Demazeau, G.; Broto, J.-M.; Millot, M.; Leps, N.; Klingeler, R.; Büchner, B.; Stone, M. B.; Zheludev, A.
2010-01-01
We present thermodynamic and neutron scattering data on silver ferrite AgFeO2. The data imply that strong magnetic frustration Θ/TN~10 and magnetic ordering arise via two successive phase transitions at T2 = 7 K and T1 = 16 K. At T
Thermodynamic properties of defects in CdTe as derived by diffusion experiments
Wagner, F; Kronenberg, J; Wichert, Th; Grill, R; Belas, E
2007-01-01
The shape of Ag profiles obtained in CdTe after 111Ag implantation and subsequent annealing strongly depends on the external conditions during the annealing procedure, yielding quite different types of diffusion profiles. By simulating these data quantitative information on different thermodynamical parameters is obtained. At the temperature of 828 K, it turns out that the experimental Ag profiles reflect the distribution of the intrinsic defects after the diffusion anneal. In this way, information on the diffusivity of the intrinsic defects, Cd interstitial and Cd vacancy, is obtained whereas for the Ag impurity only limiting values regarding ionization energy, the diffusivity of interstitially incorporated and the thermal stability of substitutionally incorporated Ag are obtained.
ms 2: A molecular simulation tool for thermodynamic properties, release 3.0
Rutkai, Gábor; Köster, Andreas; Guevara-Carrion, Gabriela; Janzen, Tatjana; Schappals, Michael; Glass, Colin W.; Bernreuther, Martin; Wafai, Amer; Stephan, Simon; Kohns, Maximilian; Reiser, Steffen; Deublein, Stephan; Horsch, Martin; Hasse, Hans; Vrabec, Jadran
2017-12-01
A new version release (3.0) of the molecular simulation tool ms 2 (Deublein et al., 2011; Glass et al. 2014) is presented. Version 3.0 of ms 2 features two additional ensembles, i.e. microcanonical (NVE) and isobaric-isoenthalpic (NpH), various Helmholtz energy derivatives in the NVE ensemble, thermodynamic integration as a method for calculating the chemical potential, the osmotic pressure for calculating the activity of solvents, the six Maxwell-Stefan diffusion coefficients of quaternary mixtures, statistics for sampling hydrogen bonds, smooth-particle mesh Ewald summation as well as the ability to carry out molecular dynamics runs for an arbitrary number of state points in a single program execution.
Borysow, Jacek; del Rosso, Leonardo; Celli, Milva; Moraldi, Massimo; Ulivi, Lorenzo
2014-04-01
We have measured the Raman Q-branch of hydrogen in a solution with water at a temperature of about 280 K and at pressures from 20 to 200 MPa. From a least-mean-square fitting analysis of the broad Raman Q-branch, we isolated the contributions from the four lowest individual roto-vibrational lines. The vibrational lines were narrower than the pure rotational Raman lines of hydrogen dissolved in water measured previously, but significantly larger than in the gas. The separations between these lines were found to be significantly smaller than in gaseous hydrogen and their widths were slightly increasing with pressure. The lines were narrowing with increasing rotational quantum number. The Raman frequencies of all roto-vibrational lines were approaching the values of gas phase hydrogen with increasing pressure. Additionally, from the comparison of the integrated intensity signal of Q-branch of hydrogen to the integrated Raman signal of the water bending mode, we have obtained the concentration of hydrogen in a solution with water along the 280 K isotherm. Hydrogen solubility increases slowly with pressure, and no deviation from a smooth behaviour was observed, even reaching thermodynamic conditions very close to the transition to the stable hydrogen hydrate. The analysis of the relative hydrogen concentration in solution on the basis of a simple thermodynamic model has allowed us to obtain the molar volume for the hydrogen gas/water solution. Interestingly, the volume relative to one hydrogen molecule in solution does not decrease with pressure and, at high pressure, is larger than the volume pertinent to one molecule of water. This is in favour of the theory of hydrophobic solvation, for which a larger and more stable structure of the water molecules is expected around a solute molecule.
Thermodynamic properties of confined square-well fluids with multiple associating sites
Trejos, Víctor M.; Quintana-H, Jacqueline
2018-02-01
In this work, a molecular simulation study of confined hard-spheres particles with square-well (SW) attractive interactions with two and four associating SW sites based on the first-order perturbation form of Wertheim's theory is presented. An extended version of the Gibbs ensemble technique for inhomogeneous fluids [A. Z. Panagiotopoulos, Mol. Phys. 62, 701 (1987)] is used to predict the adsorption density profiles for associating fluids confined between opposite parallel walls. The fluid is confined in four kinds of walls: hard-wall, SW wall, Lennard-Jones (LJ) 12-6 wall potential, and LJ 10-4 wall potential. We analyze the behavior of the confined system for several supercritical temperatures as a function of variation of molecular parameters: potential range λ, bulk densities ρb*, pore width H, cutoff range interaction rc*, and range of the potential and depth of the particle-wall (λw, ɛw*). Additionally, we include predictions for liquid-vapor coexistence of bulk associative particles and how their critical properties are modified by the presence of associative sites in the molecule. The molecular simulation data presented in this work are of prime importance to the development of theoretical approaches for inhomogeneous fluids as classical density functional theory. The simulation results presented here are resourceful for predicting adsorption isotherms of real associating fluids such as water.
First-principles calculations of lattice dynamics and thermodynamic properties for Yb14MnSb11
Wang, Yi; Hu, Yong-Jie; Firdosy, Samad A.; Star, Kurt E.; Fleurial, Jean-Pierre; Ravi, Vilupanur A.; Chen, Long-Qing; Shang, Shun-Li; Liu, Zi-Kui
2018-01-01
Systematic first-principles calculations were performed to study the lattice dynamics of Yb14MnSb11 and hence to obtain a wide range of its thermodynamic properties at high temperatures. The calculated results were analyzed in terms of the lattice contribution and the electronic contribution, together with a comparison with a collection of experimental thermochemical data. At 0 K, the electronic density of states showed the typical feature of a p-type semiconductor—a small amount of unoccupied electronic states exclusively made of the major spin by a range of ˜0.6 eV above the Fermi energy. It showed that the Mn atom had a ferromagnetic spin moment of ˜4 μB. As a semiconductor, it was found that the electronic contribution to the heat capacity was substantial, with an electronic heat capacity coefficient of ˜0.0006 J/mole-atom/K2.
Directory of Open Access Journals (Sweden)
Hiroki Iwanaga
2010-07-01
Full Text Available The paper proposes novel molecular designs for rare-earth complexes involving the introduction of two different phosphine oxide structures into one rare-earth ion. These designs are effective for improving solubility and emission intensity. Additionally, the complexes are indispensable for realizing high performances in LEDs and security media. The thermodynamic properties of Eu(III complexes are correlated with the solubility. Correlations between coordination structures and emission intensity were explained by NMR analysis. The luminous flux of red LED devices with Eu(III complexes is very high (20 mA, 870 m lumen. A new white LED has its largest spectra intensity in the red region and a human look much more vividly under this light.
Hung, Nguyen Van; Thang, Cu Sy; Duc, Nguyen Ba; Vuong, Dinh Quoc; Tien, Tong Sy
2017-12-01
Thermodynamic properties, anharmonic effects and structural determination of fcc crystals have been studied based on the theoretical and experimental Debye-Waller factors presented in terms of cumulant expansion up to the third order, thermal expansion coefficient, X-ray absorption fine structure (XAFS) spectra and their Fourier transform magnitudes. The advances in these studies are performed by the further development of the anharmonic correlated Einstein model primary only for approximating three first XAFS cumulants into the method using that all the considered theoretical and experimental XAFS parameters have been provided based on only the calculated and measured second cumulants. The obtained cumulants describe the anharmonic effects in XAFS contributing to the accurate structural determination. Numerical results for Cu are found to be in good agreement with the experimental values extracted by using the present advanced method and with those obtained by the other measurements.
DEFF Research Database (Denmark)
Bork, Nicolai Christian; Bonanos, Nikolaos; Rossmeisl, Jan
2011-01-01
V compared to two non-interacting H defects. The main cause of the net attractive potential is elastic defect interactions through lattice deformation. Two possible diffusion paths for the hydrogen defect pair are investigated and are both determined to be faster than the corresponding diffusion path...... for single hydrogen atoms. Finally, we set up a simple model to determine the contribution from the double hydrogen defect to the total hydrogen flux, and find the double defect to be the main diffusing species at temperatures below ca. 400 °C. Post submission infrared absorption experiments show excellent......A density functional theory investigation of the thermodynamic and kinetic properties of hydrogen–hydrogen defect interactions in the cubic SrTiO3 perovskite is presented. We find a net attraction between two hydrogen atoms with an optimal separation of ∼2.3 Å. The energy gain is ca. 0.33 e...
International Nuclear Information System (INIS)
Zhao, H; Aluru, N R
2007-01-01
This paper presents a semi-local quasi-harmonic model with local phonon density of states (LPDOS) to compute the thermodynamic and mechanical properties of silicon nanostructures at finite temperature. In contrast to an earlier approach (Tang and Aluru 2006 Phys. Rev. B 74 235441), where a quasi-harmonic model with LPDOS computed by a Green's function technique (QHMG) was developed considering many layers of atoms, the semi-local approach considers only two layers of atoms to compute the LPDOS. We show that the semi-local approach combines the accuracy of the QHMG approach and the computational efficiency of the local quasi-harmonic model. We present results for several silicon nanostructures to address the accuracy and efficiency of the semi-local approach
Energy Technology Data Exchange (ETDEWEB)
Steele, W.V.; Chirico, R.D.; Klots, T.D.
1993-03-01
A detailed vibrational spectroscopic study of furan, pyrrole, and thiophene has been completed. These compounds form part of the base of five-membered ring systems on which the rest of the research program will be built Several methyl-substituted derivatives were also studied. The results will be used to confirm the model for alkyl- substitution in the ring systems. Gas-phase spectra and fundamental- frequency assignments were completed for 2,3- and 2,5-dihydrofuran. Those compounds initiate work on ring-puckering within the research program. A paper describing the need for third virial estimation, when using the virial equation of state to derive thermodynamic properties at pressures greater than 1 bar was completed.
International Nuclear Information System (INIS)
Lim, Gyeong Hui
2008-03-01
This book consists of 15 chapters, which are basic conception and meaning of statistical thermodynamics, Maxwell-Boltzmann's statistics, ensemble, thermodynamics function and fluctuation, statistical dynamics with independent particle system, ideal molecular system, chemical equilibrium and chemical reaction rate in ideal gas mixture, classical statistical thermodynamics, ideal lattice model, lattice statistics and nonideal lattice model, imperfect gas theory on liquid, theory on solution, statistical thermodynamics of interface, statistical thermodynamics of a high molecule system and quantum statistics
Haq, Bakhtiar Ul
2014-02-01
In the present work we did mutual alloying of the versatile XAs (X=Ga, In, Al) materials in order to improve their efficiency and enhance their range of technological applications using state of the art first principles method. We investigate the structural, electronic and thermodynamic properties of Ga1-xAlxAs, Ga1-xInxAs and In1-xAlxAs for x=0.25, 0.50, and 0.75. Calculations have been performed using the density functional theory (DFT) as implemented within the full potential linearized augmented plane wave plus local orbital (FP-LAPW+lo) method. For exchange and correlation energy treatment, we employed the local density approximations (LDA) as proposed by Wang and Perdew and the generalized gradient approximation (GGA) from Perdew et al. proposed. To calculate the accurate band structure, recently modified Becke Johnson (mBJ) potential was suggested as an alternative. Our calculations show a linear fall in the lattice constant in contrast to linear rise in bulk moduli of Ga1-xAlxAs and In1-xAlxAs with the increase of Al concentration. However the change of indium concentration in Ga1-xInxAs is displaying a reverse effect. The energy band gap of Ga1-xAlxAs and In1-xAlxAs was found to be increased, where a crossover from direct to indirect band gap has been observed with the increase of Al concentration. This direct to indirect crossover was found at 93.4% of Al concentration for Ga1-xAlxAs and at 84.63% of Al concentration for In1-xAlxAs. The effect of the mutual alloying of XAs materials on the thermodynamic properties is comprehensively reported. © 2013 Elsevier Ltd.
International Nuclear Information System (INIS)
Jendrzejczyk-Handzlik, Dominika; Fitzner, Krzysztof
2011-01-01
The thermodynamic properties of the liquid Ag-Ga alloys were determined using e.m.f. and calorimetric methods. In the e.m.f. method, solid oxide galvanic cells were used with zirconia electrolyte. The cells of the type W,Ag x Ga (1-x) ,Ga 2 O 3 //ZrO 2 +(Y 2 O 3 )//FeO,Fe,W were used in the temperature range from 1098 K to 1273 K, and in the range of mole fraction from x Ga = 0.1 to x Ga = 1.0. At first, the Gibbs free energy of formation of pure solid gallium oxide, Ga 2 O 3 , from pure elements was derived. Using values of the measured e.m.f. for the cell with x Ga = 1.0, the following temperature dependence was obtained: Δ f G m,Ga 2 O 3 0 (±4kJ·mol -1 J)=-1061.7235+0.2899T/K. Next, the activity of the gallium was derived as a function of the alloy composition from the values of the measured e.m.f. Activities of silver were calculated using the Gibbs-Duhem equation. The drop calorimetric measurements were carried out at two temperatures, viz. 923 K and 1123 K, using a Setaram MHTC calorimeter. Integral enthalpies of mixing of liquid binary alloys were determined at those temperatures. Finally, thermodynamic properties of the liquid alloys were described with the Redlich-Kister equation using ThermoCalc software.
Boulechfar, R.; Khenioui, Y.; Drablia, S.; Meradji, H.; Abu-Jafar, M.; Omran, S. Bin; Khenata, R.; Ghemid, S.
2018-05-01
Ab-initio calculations based on density functional theory have been performed to study the structural, electronic, thermodynamic and mechanical properties of intermetallic compounds Pt3Sc and Pt3Y using the full-potential linearized augmented plane wave(FP-LAPW) method. The total energy calculations performed for L12, D022 and D024 structures confirm the experimental phase stability. Using the generalized gradient approximation (GGA), the values of enthalpies formation are -1.23 eV/atom and -1.18 eV/atom for Pt3Sc and Pt3Y, respectively. The densities of states (DOS) spectra show the existence of a pseudo-gap at the Fermi level for both compounds which indicate the strong spd hybridization and directing covalent bonding. Furthermore, the density of states at the Fermi level N(EF), the electronic specific heat coefficient (γele) and the number of bonding electrons per atom are predicted in addition to the elastic constants (C11, C12 and C44). The shear modulus (GH), Young's modulus (E), Poisson's ratio (ν), anisotropy factor (A), ratio of B/GH and Cauchy pressure (C12-C44) are also estimated. These parameters show that the Pt3Sc and Pt3Y are ductile compounds. The thermodynamic properties were calculated using the quasi-harmonic Debye model to account for their lattice vibrations. In addition, the influence of the temperature and pressure was analyzed on the heat capacities (Cp and Cv), thermal expansion coefficient (α), Debye temperature (θD) and Grüneisen parameter (γ).
Granet, Irving
2014-01-01
Fundamental ConceptsIntroductionThermodynamic SystemsTemperatureForce and MassElementary Kinetic Theory of GasesPressureReviewKey TermsEquations Developed in This ChapterQuestionsProblemsWork, Energy, and HeatIntroductionWorkEnergyInternal EnergyPotential EnergyKinetic EnergyHeatFlow WorkNonflow WorkReviewKey TermsEquations Developed in This ChapterQuestionsProblemsFirst Law of ThermodynamicsIntroductionFirst Law of ThermodynamicsNonflow SystemSteady-Flow SystemApplications of First Law of ThermodynamicsReviewKey TermsEquations Developed in This ChapterQuestionsProblemsThe Second Law of ThermodynamicsIntroductionReversibility-Second Law of ThermodynamicsThe Carnot CycleEntropyReviewKey TermsEquations Developed in This ChapterQuestionsProblemsProperties of Liquids and GasesIntroductionLiquids and VaporsThermodynamic Properties of SteamComputerized PropertiesThermodynamic DiagramsProcessesReviewKey TermsEquations Developed in This ChapterQuestionsProblemsThe Ideal GasIntroductionBasic ConsiderationsSpecific Hea...
Chiral thermodynamics of nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Fiorilla, Salvatore
2012-10-23
The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.
Chiral thermodynamics of nuclear matter
International Nuclear Information System (INIS)
Fiorilla, Salvatore
2012-01-01
The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.
Energy Technology Data Exchange (ETDEWEB)
Hug, Alexander
2011-05-04
Knowledge of basic physical properties of matter in high-energy-density (HED) states such as the equation-of-state (EOS) is of fundamental importance for various branches of basic and applied physics. However, such matter under extreme conditions of temperature and pressure - also called ''warm dense matter'' (WDM) - can only be generated in dynamic experiments employing the most powerful drivers. At the high temperature experimental area HHT of the GSI Helmholtzzentrum fuer Schwerionenforschung (Darmstadt, Germany), intense beams of energetic heavy ions are used for this purpose. The aim of this work is to study thermophysical properties of refractory metals in hot solid and liquid states by precise temperature measurements. In order to identify the melting plateau and to limit the maximum target temperature to the region of interest, relatively long (one microsecond) bunches of uranium and xenon ions have been used to heat initially solid samples. The intense ion beams were focused on a millimetre spot at the target in order to achieve uniform conditions. The temperature on the target surface was determined by analysing thermal radiation emitted from a 0.03 mm{sup 2} area at five different wavelengths. In order to obtain the physical temperature, one has to measure not only the thermal radiation but also the emissivity, ε(T,λ) of the target surface which is not known ab initio. For this purpose, a set-up for direct target reflection measurement was designed and embedded into the fast multichannel pyrometer system. The reflection signal provides the necessary information about modifications of the target surface properties during the interaction with the ion beam. Beside the pyrometric and reflection measurement set-ups, various hardware and software components of the data acquisition system for the heavy-ion beam driven experiments were substantially enhanced. The emissivity was also obtained by identifying the melting plateau and using the
Clarke, W. P.; Jacobsen, R. T.; Lemmon, E. W.; Penoncello, S. G.; Beyerlein, S. W.
1994-11-01
A formulation developed previously for the prediction of the thermodynamic properties of single-phase states of binary and ternary mixtures in the nitrogen-argon-oxygen system has been revised to include the calculation of vapor-liquid equilibrium (VLE) properties. The model is based on the theory of extended corresponding states with van der Waals mixing rules. Binary interaction parameters have been determined with single-phase P-p-T and vaporliquid equilibrium data to improve the accuracy of thermodynamic property predictions. The model accurately represents single-phase and vapor-liquid equilibrium properties over a wide range of compositions for binary and ternary mixtures. Comparisons of calculated properties to selected mixture data for both single-phase and VLE states are included.
Aryal, Sita Ram
The alumino-silicate solid solution series (Al 4+2xSi2-2 xO10-x) is an important class of ceramics. Except for the end member (x=0), Al2 SiO5 the crystal structures of the other phases, called mullite, have partially occupied sites. Stoichiometric supercell models for the four mullite phases 3Al2O 3 · 2SiO2 · 2Al 2O3 · SiO2, 4 Al2O3· SiO 2, 9Al2O3 · SiO2, and iota-Al2 O3 (iota-alumina) are constructed starting from experimentally reported crystal structures. A large number of models were built for each phase and relaxed using the Vienna ab initio simulation package (VASP) program. The model with the lowest total energy for a given x was chosen as the representative structure for that phase. Electronic structure and mechanical properties of mullite phases were studied via first-principles calculations. Of the various phases of transition alumina, iota-Al 2O3 is the least well known. In addition structural details have not, until now, been available. It is the end member of the aluminosilicate solid solution series with x=1. Based on a high alumina content mullite phase, a structural model for iota- Al2O3 is constructed. The simulated x-ray diffraction (XRD) pattern of this model agrees well with a measured XRD pattern. The iota-Al2 O3 is a highly disordered ultra-low-density phase of alumina with a theoretical density of 2854kg/m3. Using this theoretically constructed model, elastic, thermodynamic, electronic, and spectroscopic properties of iota-Al2 O3 have been calculated and compared it with those of alpha- Al2O3 and gamma- Al2O3. Boron carbide (B4C) undergoes an amorphization under high velocity impacts. The mechanism of amorphization is not clear. Ab initio methods are used to carry out large-scale uniaxial compression simulations on two polytypes of stoichiometric boron carbide (B4C), B 11C-CBC, and B12- CCC where B11C or B12 is the 12-atom icosahedron and CBC or CCC is the three-atom chain. The simulations were performed on large supercells of 180 atoms
Blending Education and Polymer Science: Semiautomated Creation of a Thermodynamic Property Database
Tchoua, Roselyne B.; Qin, Jian; Audus, Debra J.; Chard, Kyle; Foster, Ian T.; de Pablo, Juan
2016-01-01
Structured databases of chemical and physical properties play a central role in the everyday research activities of scientists and engineers. In materials science, researchers and engineers turn to these databases to quickly query, compare, and aggregate various properties, thereby allowing for the development or application of new materials. The…
Thermodynamics of nanoadsorption from solution: Theoretical and experimental research
International Nuclear Information System (INIS)
Wen, Yan-Zhen; Xue, Yong-Qiang; Cui, Zi-Xiang; Wang, Yan
2015-01-01
Highlights: • The thermodynamic theory of nanoadsorption was proposed. • The thermodynamic relations of nanoadsorption were derived. • The results of the experiments are accord with the theory. - Abstract: In this study, the effect of nanoparticle size on adsorption thermodynamics was investigated. The results of theoretical and experimental studies show that particle size significantly affects the equilibrium constant and thermodynamic properties of nanoadsorption. Relationships between the equilibrium constant, thermodynamic properties and particle size were derived using the thermodynamic theory of nanoadsorption. The equilibrium constant and thermodynamic properties were obtained by investigating the adsorption of Cu 2+ onto different sizes of nano-ZnO and the adsorption of Ag + onto different sizes of nano-TiO 2 . Good agreement was achieved between results obtained by experiments and predicted by theoretical analyses. The equilibrium constant and the molar Gibbs free energy of nanoadsorption were found to increase with smaller nanoparticle size. However, the effects of particle size on the molar enthalpy and the molar entropy are uncertain. In addition, the molar Gibbs free energy, the molar enthalpy, the molar entropy and the logarithm of the equilibrium constant are linearly related to the reciprocal of the diameter of the nanoparticle. The thermodynamic properties revealed in this study may provide important guidelines for research and application in the field of nanoadsorption
Directory of Open Access Journals (Sweden)
Liliana Giraldo
2008-10-01
Full Text Available The interaction of guest molecules ranging from pentan-1-ol to octan-1-ol with ÃŽÂ±-cyclodextrin (ÃŽÂ±-CD in water of has been studied calorimetrically at 283.15, 288.15, 293.15, 298.15 and 308.15 K with an isoperibolic titration calorimeter designed in our laboratory. The calorimetric method employed allows the determination of the thermodynamic parameters characterizing the binding process, ÃŽÂ”GÃ‚Â°m, ÃŽÂ”HÃ‚Â°m, ÃŽÂ”SÃ‚Â°mand ÃŽÂ”CpÃ‚Â°, namely free energy, enthalpy, and calorific capacity. These results show that in the temperature range investigated, the entropy change increased with chain length. This is in line with what is expected for a hydrophobic dehydration process. However, that effect is not expected to lead to the more pronounced negative CH2-increment observed for nc > 5 or 6. As for many other ligand binding processes, we can observe a significant enthalpy - entropy compensation for this system, both with respect to temperature and structure.
Energy Technology Data Exchange (ETDEWEB)
Moreno-Pirajan, J. C. [Universidad de los Andes, Bogota, Grupo de investigacion en solidos porosos y calorimetria, Departamento de Quimica, Facultad de Ciencias / Carrera 1 No.18 A10, Bogota (Colombia); Giraldo, L. [Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Quimica / Ciudad Universitaria, Bogota (Colombia)
2008-07-01
The interaction of guest molecules ranging from pentan-1-ol to octan-1-ol with {alpha}-cyclodextrin ({alpha}-CD) in water of has been studied calorimetrically at 283.15, 288.15, 293.15, 298.15 and 308.15 K with an isoperibolic titration calorimeter designed in our laboratory. The calorimetric method employed allows the determination of the thermodynamic parameters characterizing the binding process, {delta}G {sup o}{sub m}, {delta}H {sup o}{sub m}, {delta}S {sup o}{sub m} and {delta}Cp {sup o}, namely free energy, enthalpy, and calorific capacity. These results show that in the temperature range investigated, the entropy change increased with chain length. This is in line with what is expected for a hydrophobic dehydration process. However, that effect is not expected to lead to the more pronounced negative CH{sub 2}-increment observed for n{sub c} > 5 or 6. As for many other ligand binding processes, we can observe a significant enthalpy - entropy compensation for this system, both with respect to temperature and structure. (author)
Properties of Reduced Carbon Dioxide Fluid: Evidence from Experimental and Thermodynamic Modeling
Simakin, A. G.; Devyatova, V. N.; Salova, T. P.; Zelensky, M. E.
2018-01-01
It is shown experimentally that fluid mostly consisting of CO2 and CO is a good solvent for many petrogenic and ore components under high P-T parameters. Siderite decomposed to oxides and a mixture of CO2 and CO was the source of the fluid in the experiment. It is demonstrated that an ultrapotassic alkaline melt was formed on the oxide matrix as a result of fluid transport of the components of the basaltic melt at 2-5 kbar and 900-1000°C. This melt is characterized by high concentrations of Rb, LREE, Sr, and Ba. The mechanism of solubility of metals in the carbon dioxide-reduced fluid includes the formation of volatile carbonyls. As is evident from thermodynamic modeling, the stability of Ni(CO)4 at high pressure reaches magmatic temperatures. The finding of native nickel in aerosols during eruption of the Tolbachik Volcano in 2012-2013 is explained by decomposition of carbonyl from fluid of a deep origin during magma ascent.
International Nuclear Information System (INIS)
Gomez Palacio, German Rau
1998-01-01
Ecology is no more a descriptive and self-sufficient science. Many viewpoints are needed simultaneously to give a full coverage of such complex systems: ecosystems. These viewpoints come from physics, chemistry, and nuclear physics, without a new far from equilibrium thermodynamics and without new mathematical tools such as catastrophe theory, fractal theory, cybernetics and network theory, the development of ecosystem science would never have reached the point of today. Some ideas are presented about the importance that concept such as energy, entropy, exergy information and none equilibrium have in the analysis of processes taking place in ecosystems
Onyeaju, M. C.; Ikot, A. N.; Onate, C. A.; Ebomwonyi, O.; Udoh, M. E.; Idiodi, J. O. A.
2017-07-01
The Pekeris approximate scheme is introduced to deal with the centrifugal term in a Dirac equation with the deformed Hylleraas plus Woods-Saxon (DHWS) potential model. The relativistic energy solutions for the spin and pseudospin symmetries are obtained via the Nikiforov-Uvarov (NU) method. In the non-relativistic limits we calculated the thermodynamics properties for some selected diatomic molecules.
Czech Academy of Sciences Publication Activity Database
Leszczynski, J.; Da Ros, V.; Lenoir, B.; Dauscher, A.; Candolfi, C.; Masschelein, P.; Hejtmánek, Jiří; Kutorasinski, K.; Tobola, J.; Smith, R.I.; Stiewe, C.; Müller, E.
2013-01-01
Roč. 46, č. 49 (2013), "495106-1"-"495106-13" ISSN 0022-3727 R&D Projects: GA MŠk(CZ) 7AMB12FR019 Institutional support: RVO:68378271 Keywords : thermoelectric and thermodynamic properties * skutterudites Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.521, year: 2013
Thermodynamic properties of tooeleite, Fe63+(As3+O3)4(SO4)(OH)4·4H2O
DEFF Research Database (Denmark)
Majzlan, Juraj; Dachs, Edgar; Benisek, Artur
2016-01-01
-As-S-O-H. In this contribution, we report the thermodynamic properties of synthetic tooeleite. The sample was characterized by powder X-ray diffraction, scanning electron microscopy, extended X-ray absorption fine-structure spectroscopy, and Mössbauer spectroscopy. These methods confirmed that the sample is pure, devoid...
Apol, M.E F; Amadei, A; Berendsen, H.J.C.
1996-01-01
In this article we investigate the applicability of the statistical Gamma state as following from the quasi-Gaussian entropy theory, where all thermodynamic properties at every temperature are obtained from the knowledge of the potential energy distribution at one temperature. We compared for a
Thermodynamical and thermoelectric properties of boron doped YPd{sub 3} and YRh{sub 3}
Energy Technology Data Exchange (ETDEWEB)
Dwivedi, Shalini; Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Theoretical Condensed Matter Physics Laboratory, Dept. of Physics, Feroze Gandhi College, Raebareli-229001 U.P (India); Sharma, Ramesh [Dept. of Physics, Mewar University, Chittorgarh-312901 Rajasthan (India)
2016-05-23
The structural, electronic, thermal, and optical properties of borides of cubic non-magnetic YX{sub 3} (X=Rh, Pd) compounds and their borides which crystallize in the AuCu{sub 3} structure have been studied using the density functional theory (DFT). The flat bands in the vicinity of E{sub F} which are associated with superconductivity appear in YPd{sub 3} and YRh{sub 3} band structures. However, the B s-states enhance the flat band only in YRh{sub 3}B. The optical properties clearly show that boron insertion modifies the absorption and transmittance. The YX{sub 3} alloys and their borides exhibit valuable changes in the thermopower and ZT. It is observed that the properties of the Y-X intermetallics change significantly for the Y-Rh and Y-Pd alloys and the presence of single boron atom modifies the properties to a great extent.
Thermodynamic and Mechanical Properties of Epon 862 With Curing Agent Detda by Molecular Simulation
National Research Council Canada - National Science Library
Tack, Jeremy L
2006-01-01
Fully atomistic molecular dynamics (MD) simulations were used to predict the properties of EPON 862 cross-linked with curing agent DETDA, a potentially useful epoxy resin for future applications of nanocomposites...
Thermodynamic modeling of CO2 mixtures
DEFF Research Database (Denmark)
Bjørner, Martin Gamel
Knowledge of the thermodynamic properties and phase equilibria of mixtures containing carbon dioxide (CO2) is important in several industrial processes such as enhanced oil recovery, carbon capture and storage, and supercritical extractions, where CO2 is used as a solvent. Despite this importance......, accurate predictions of the thermodynamic properties and phase equilibria of mixtures containing CO2 are challenging with classical models such as the Soave-Redlich-Kwong (SRK) equation of state (EoS). This is believed to be due to the fact, that CO2 has a large quadrupole moment which the classical models...... and with or without introducing an additional pure compound parameter. In the absence of quadrupolar compounds qCPA reduces to CPA, which itself reduces toSRK in the absence of association. As the number of adjustable parameters in thermodynamic models increase, the parameter estimation problem becomes increasingly...
International Nuclear Information System (INIS)
Zaitsev, A I; Zaitseva, N E; Shimko, R Yu; Arutyunyan, N A; Dunaev, S F; Kraposhin, V S; Lam, Ha Thanh
2008-01-01
Thermodynamic properties of molten Al-Mn, Al-Cu and Al-Fe-Cu alloys in a wide temperature range of 1123-1878 K and the whole range of concentrations have been studied using the integral effusion method and Knudsen mass spectrometry. Thermodynamic functions of melts were described by the associated solution model. The possibility of icosahedral quasicrystal (i-QC) precipitation from liquid Al-Mn and Al-Cu-Fe alloys was found to be a consequence of the existence in liquid associates (clusters). A geometric model is suggested for the structure of associates in liquid
Gupta, Roop N.; Yos, Jerrold M.; Thompson, Richard A.
1989-01-01
Reaction rate coefficients and thermodynamic and transport properties are provided for the 11-species air model which can be used for analyzing flows in chemical and thermal nonequilibrium. Such flows will likely occur around currently planned and future hypersonic vehicles. Guidelines for determining the state of the surrounding environment are provided. Approximate and more exact formulas are provided for computing the properties of partially ionized air mixtures in such environments.
Analyses and predictions of the thermodynamic properties and phase diagrams of silicate systems
Energy Technology Data Exchange (ETDEWEB)
Blander, M. [Argonne National Lab., IL (United States); Pelton, A.; Eriksson, G. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. of Metallurgy and Materials Engineering
1992-07-01
Molten silicates are ordered solutions which can not be well represented by the usual polynomial representation of deviations from ideal solution behavior (i.e. excess free energies of mixing). An adaptation of quasichemical theory which is capable of describing the properties of ordered solutions represents the measured properties of binary silicates over broad ranges of composition and temperature. For simple silicates such as the MgO-FeO-SiO{sub 2} ternary system, in which silica is the only acid component, a combining rule generally leads to good predictions of ternary solutions from those of the binaries. In basic solutions, these predictions are consistent with those of the conformal ionic solution theory. Our results indicate that our approach could provide a potentially powerful tool for representing and predicting the properties of multicomponent molten silicates.
Analyses and predictions of the thermodynamic properties and phase diagrams of silicate systems
Energy Technology Data Exchange (ETDEWEB)
Blander, M. (Argonne National Lab., IL (United States)); Pelton, A.; Eriksson, G. (Ecole Polytechnique, Montreal, PQ (Canada). Dept. of Metallurgy and Materials Engineering)
1992-01-01
Molten silicates are ordered solutions which can not be well represented by the usual polynomial representation of deviations from ideal solution behavior (i.e. excess free energies of mixing). An adaptation of quasichemical theory which is capable of describing the properties of ordered solutions represents the measured properties of binary silicates over broad ranges of composition and temperature. For simple silicates such as the MgO-FeO-SiO{sub 2} ternary system, in which silica is the only acid component, a combining rule generally leads to good predictions of ternary solutions from those of the binaries. In basic solutions, these predictions are consistent with those of the conformal ionic solution theory. Our results indicate that our approach could provide a potentially powerful tool for representing and predicting the properties of multicomponent molten silicates.
Bhat, Tahir Mohiuddin; Gupta, Dinesh C.
2018-03-01
Employing first-principles based on density functional theory we have investigated the structural, magneto-electronic, thermoelectric and thermodynamic properties of quaternary Heusler alloy CoFeCrAl. Electronic band structure displays that CoFeCrAl is an indirect band gap semiconductor in spin-down state with the band gap value of 0.65 eV. Elastic constants reveal CoFeCrAl is a mechanically stable structure having a Debye temperature of 648 K along with a high melting temperature (2130 K). The thermoelectric properties in the temperature range 50-800 K have been calculated. CoFeCrAl possesses a high Seebeck coefficient of - 46 μV/K at room temperature along with the huge power factor of ˜ 4.8 (1012 μW cm-1 K-2 s-1) which maximizes the figure-of-merit up to ˜ 0.75 at 800 K temperature and suggesting CoFeCrAl as potential thermoelectric material. The effect of high pressure and high temperature on the thermal expansion, Grüneisen parameter and heat capacity were also studied by using the quasi-harmonic Debye model.
Moreno, Daniel; Gonzalez-Miquel, Maria; Ferro, Victor R; Palomar, Jose
2018-04-05
Zwitterion ionic liquids (ZIs) are compounds in which both counterions are covalently tethered, conferring them with unique characteristics; however, most of their properties are still unknown, representing a bottleneck to exploit their practical applications. Herein, the molecular and fluid properties of ZIs and their mixtures were explored by means of quantum chemical analysis based on the density functional theory (DFT) and COSMO-RS method, and compared against homologous ionic liquids (ILs) to provide a comprehensive overview of the effect of the distinct structures on their physicochemical and thermodynamic behavior. Overall, ZIs were revealed as compounds with higher polarity and stronger hydrogen-bonding capacity, implying higher density, viscosity, melting point, and even lower volatility than structurally similar ILs. The phase equilibrium of binary and ternary systems supports stronger attractive interactions between ZIs and polar compounds, whereas higher liquid-liquid immiscibility with nonpolar compounds may be expected. Ultimately, the performance of ZIs in the wider context of separation processes is illustrated, while providing molecular insights to allow their selection and design for relevant applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
International Nuclear Information System (INIS)
Polishuk, Ilya; Perel, Ariel
2012-01-01
Highlights: ► PC-SAFT and SAFT + Cubic are used for modeling properties of 1-alkenes and their mixtures. ► SAFT + Cubic appears as a better estimator of pure compound data than PC-SAFT. ► SAFT + Cubic is superior in modeling inter-relation between VLE and LLE in mixtures. - Abstract: In the current study the widely used theoretically based model PC-SAFT and the recently proposed SAFT + Cubic have been implemented for correlating and predicting various thermodynamic properties of 1-Hexene, 1-Heptene, 1-Octene, 1-Nonene, 1-Decene, 1-Dodecene, 1-Tetradecene, and 1-Hexadecene, and the available high pressure data on their mixtures. Unlike PC-SAFT, SAFT + Cubic is capable of correlating the critical and subcritical pure compound data simultaneously. In addition, SAFT + Cubic is advantageous in predicting the isothermal compressibility factors and sound velocities. It is also superior in correlating the complex phase behavior in the asymmetric systems {Methane(1) + 1-Hexene(2)} and {Methane(1) + 1-Heptene(2)}. Overestimation of critical temperatures and pressures affects the accuracy of PC-SAFT in predicting VLE in the system {n-Hexane(1) + 1-Hexadecene(2)}. At the same time, this disadvantage of PC-SAFT possibly turns into advantage while modeling the VLE data of {Carbon Dioxide(1) + 1-Hexene(2)}. As seems, both of them are capable of only rough estimation of the heat capacity data.
International Nuclear Information System (INIS)
Zhou, Jianting; Zhang, Hong; Chen, Yue; Shong, Jun; Chen, Zhuo; Yang, Juan; Zheng, Zhou; Wang, Feng
2014-01-01
In this work, based on density functional theory and quasi-harmonic Debye model, mechanical and thermodynamic properties of orthorhombic Mg 2 SiO 4 under high temperature are predicted. We found out that α-Mg 2 SiO 4 is mechanically stable under the condition from about 0 to 74 GPa. Results indicate that the main cause of mechanical instability is high pressure, and the effect caused by high temperature is small. C 11 , C 22 , C 33 , B and v p reduce with temperature just a little and increase with pressure obviously. Mg 2 SiO 4 has excellent resistance to strong compression; however the resistance to shear is unsatisfactory. The C v tends to the Petit and Dulong limit at high temperature under any pressure, and it is proportional to T 3 at extremely low temperature. Pressure has an opposite effect on C v than temperature. The suppressed effect on C v caused by pressure is not obvious under low and very high temperature. Mg 2 SiO 4 has three different thermal expansion coefficients (α) along a-, b- and c-axes, and α a <α c <α b . α increases rapidly at low temperature (about <300 K), and slows down at high temperature. High pressure would greatly suppress expansion caused by temperature. Nevertheless, increasing tendency of α b and α c is still obvious under high pressure, especially α b . All the properties are mainly due to Si–O covalent bonds and their directions
Zhang, Yunong; Shi, Quan; Schliesser, Jacob; Woodfield, Brian F; Nan, Zhaodong
2014-10-06
Normal spinel zinc ferrite (ZnFe2O4) nanoparticles (NPs) with zero net magnetization were synthesized by a facile coprecipitation method in which two kinds of organic alkali, namely, 1-amino-2-propanol (MIPA) and bis(2-hydroxypropyl)-amine (DIPA), were used. The diameters of the ZnFe2O4 NPs were determined to be about 7 and 9 nm for samples prepared with MIPA and DIPA, respectively, and the normal spinel structure was confirmed by the magnetic property measurement at room temperature and the temperature dependence of the direct current magnetization. These results are different from those reported in the literature, where ZnFe2O4 NPs show a nonzero net magnetization. The heat capacity of the ZnFe2O4 NPs synthesized using DIPA was measured using a physical property measurement system in the temperature range from 2 to 300 K, and the thermodynamic functions were calculated based on the curve fitting of the experimental heat capacity data. The heat capacity of the ZnFe2O4 NPs was compared with that of a nanosized (Zn(0.795)Fe(0.205))[Zn(0.205)Fe(1.795)]O4 material studied in the literature, indicating that the Debye temperature of the present sample is more comparable with that of the bulk ZnFe2O4 reported by Westrum et al.
Venkateswaran, S.; Hunt, L. Roane; Prabhu, Ramadas K.
1992-01-01
The Langley 8 foot high temperature tunnel (8 ft HTT) is used to test components of hypersonic vehicles for aerothermal loads definition and structural component verification. The test medium of the 8 ft HTT is obtained by burning a mixture of methane and air under high pressure; the combustion products are expanded through an axisymmetric conical contoured nozzle to simulate atmospheric flight at Mach 7. This facility was modified to raise the oxygen content of the test medium to match that of air and to include Mach 4 and Mach 5 capabilities. These modifications will facilitate the testing of hypersonic air breathing propulsion systems for a wide range of flight conditions. A computational method to predict the thermodynamic, transport, and flow properties of the equilibrium chemically reacting oxygen enriched methane-air combustion products was implemented in a computer code. This code calculates the fuel, air, and oxygen mass flow rates and test section flow properties for Mach 7, 5, and 4 nozzle configurations for given combustor and mixer conditions. Salient features of the 8 ft HTT are described, and some of the predicted tunnel operational characteristics are presented in the carpet plots to assist users in preparing test plans.
Thermodynamical properties of III-V nitrides and crystal growth of GaN at high N 2 pressure
Porowski, S.; Grzegory, I.
1997-06-01
In this paper, thermodynamical properties of AIN, GaN and InN are considered. It is shown that significant differences in melting conditions, thermal stability and solubilities in liquid group III metals lead to different possibilities of growing crystals from high temperature solutions, at N 2 pressure up to 20 kbar. It is shown that the best conditions for crystal growth at available pressure and temperature conditions can be achieved for GaN. High quality 6-10 mm single crystals of GaN have been grown at high N 2 pressure in 60-150 h processes. The mechanisms of nucleation and growth of GaN crystals are discussed on the basis of the experimental results. The crystallization of AlN is less efficient due to relatively low solubility of AlN in liquid Al. Possibility for the growth of InN crystals is strongly limited since this compound loses its stability at T > 600°C, even at 2 GPa N 2 pressure. The crystals of GaN grown at high pressure are the first crystals of this material used for homoepitaxial layer deposition. Both MOCVD and MBE methods have been successfully applied. Structural, electrical and optical properties of both GaN single crystals and homoepitaxial layers are reviewed.
Višňak, Jakub; Sobek, Lukáš
2016-11-01
A brief introduction into computational methodology and preliminary results for spectroscopic (excitation energies, vibrational frequencies in ground and excited electronic states) and thermodynamic (stability constants, standard enthalpies and entropies of complexation reactions) properties of some 1:1, 1:2 and 1:3 uranyl sulphato- and selenato- complexes in aqueos solutions will be given. The relativistic effects are included via Effective Core Potential (ECP), electron correlation via (TD)DFT/B3LYP (dispersion interaction corrected) and solvation is described via explicit inclusion of one hydration sphere beyond the coordinated water molecules. We acknowledge limits of this approximate description - more accurate calculations (ranging from semi-phenomenological two-component spin-orbit coupling up to four-component Dirac-Coulomb-Breit hamiltonian) and Molecular Dynamics simulations are in preparation. The computational results are compared with the experimental results from Time-resolved Laser-induced Fluorescence Spectroscopy (TRLFS) and UV-VIS spectroscopic studies (including our original experimental research on this topic). In case of the TRLFS and UV-VIS speciation studies, the problem of complex solution spectra decomposition into individual components is ill-conditioned and hints from theoretical chemistry could be very important. Qualitative agreement between our quantum chemical calculations of the spectroscopic properties and experimental data was achieved. Possible applications for geochemical modelling (e.g. safety studies of nuclear waste repositories, modelling of a future mining site) and analytical chemical studies (including natural samples) are discussed.
Directory of Open Access Journals (Sweden)
Seyyedeh Soghra Mousavi
2010-08-01
Full Text Available Seyyedeh Soghra Mousavi1, Hanieh Bokharaie2, Shadi Rahimi3, Sima Azadi Soror4, Mehrdad Hamidi51Department of Biotechnology, School of Pharmacy, Zanjan University of Medical Science, Zanjan, Iran; 2Genetic Group, Biology Department, Faculty of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran; 3Department of Biology, Faculty of Science, Tarbiat Moallem University, Tehran, Iran: 4Plant Protection Department, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran; 5Department of Pharmaceutics, School of Pharmacy, Zanjan University of Medical Science, Zanjan, IranAbstract: In recent years, due to vital need for novel fungicidal agents, investigation on natural antifungal resources has been increased. The special features exhibited by neural network classifiers make them suitable for handling complex problems like analyzing different properties of candidate compounds in computer-aided drug design. In this study, by using a Levenberg–Marquardt (LM neural network (the fastest of the training algorithms, the relation between some important thermodynamic and physico-chemical properties of coumarin compounds and their biological activities (tested against Candida albicans has been evaluated. A set of already reported antifungal bioactive coumarin and some well-known physical descriptors have been selected and using LM training algorithm the best architecture of neural model has been designed for forecasting the new bioactive compounds.Keywords: Levenberg–Marquardt algorithm, coumarin, neural network
Directory of Open Access Journals (Sweden)
Višňak Jakub
2016-01-01
Full Text Available A brief introduction into computational methodology and preliminary results for spectroscopic (excitation energies, vibrational frequencies in ground and excited electronic states and thermodynamic (stability constants, standard enthalpies and entropies of complexation reactions properties of some 1:1, 1:2 and 1:3 uranyl sulphato- and selenato- complexes in aqueos solutions will be given. The relativistic effects are included via Effective Core Potential (ECP, electron correlation via (TDDFT/B3LYP (dispersion interaction corrected and solvation is described via explicit inclusion of one hydration sphere beyond the coordinated water molecules. We acknowledge limits of this approximate description – more accurate calculations (ranging from semi-phenomenological two-component spin-orbit coupling up to four-component Dirac-Coulomb-Breit hamiltonian and Molecular Dynamics simulations are in preparation. The computational results are compared with the experimental results from Time-resolved Laser-induced Fluorescence Spectroscopy (TRLFS and UV-VIS spectroscopic studies (including our original experimental research on this topic. In case of the TRLFS and UV-VIS speciation studies, the problem of complex solution spectra decomposition into individual components is ill-conditioned and hints from theoretical chemistry could be very important. Qualitative agreement between our quantum chemical calculations of the spectroscopic properties and experimental data was achieved. Possible applications for geochemical modelling (e.g. safety studies of nuclear waste repositories, modelling of a future mining site and analytical chemical studies (including natural samples are discussed.
International Nuclear Information System (INIS)
Djamali, Essmaiil; Cobble, James W.
2009-01-01
Standard state thermodynamic properties for fully ionized aqueous perrhenic acid at temperature in the range of (298.15 to 598.15) K and at p sat were determined by high dilution solution calorimetry (10 -4 m). A comparison of the standard state thermodynamic properties for fully ionized aqueous perrhenic acid, HReO 4 (aq), and sodium perrhenate, NaReO 4 (aq), establishes for the first time the quantitative values for the differences between H + (aq) and Na + (aq) from temperature of (298.15 to 598.15) K. Perrhenic acid is believed to be the first strong acid to be thermodynamically well characterized under standard state conditions to date from measurements down to 10 -4 m. The value of the Debye-Hueckel limiting slope for enthalpies of dilution at temperature of 596.30 K of 122 ± 6 kJ . mol -3/2 . kg 1/2 , obtained from the integral heats of solution measurement at various concentrations, is in good agreement with theoretical value in literature, 121 kJ . mol -3/2 . kg 1/2 . This agreement verifies that HReO 4 (aq) obeys the simple limiting law for strong electrolytes. Many thermodynamic properties of soluble sodium electrolytes can now be converted to the corresponding acid form.
International Nuclear Information System (INIS)
Garcia-Moliner, F.
1975-01-01
Basic thermodynamics of a system consisting of two bulk phases with an interface. Solid surfaces: general. Discussion of experimental data on surface tension and related concepts. Adsorption thermodynamics in the Gibbsian scheme. Adsorption on inert solid adsorbents. Systems with electrical charges: chemistry and thermodynamics of imperfect crystals. Thermodynamics of charged surfaces. Simple models of charge transfer chemisorption. Adsorption heat and related concepts. Surface phase transitions
Magnetic properties and thermodynamics of decorated Ising chain with pendants of arbitrary spin
Energy Technology Data Exchange (ETDEWEB)
Li Wei, E-mail: liwei-b09@mails.gucas.ac.c [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China); Department of Physics, Beihang University, Beijing 100191 (China); Gong Shoushu [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China); Chen Ziyu [Department of Physics, Beihang University, Beijing 100191 (China); Zhao Yang [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China); Su Gang, E-mail: gsu@gucas.ac.c [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China)
2010-05-31
The decorated Ising chain with pendants of arbitrary spin and the single-ion anisotropy is exactly solved by the transfer matrix method. The solutions reveal abundant novel properties than the conventional one-dimensional Ising model. It is compared with the experimental data of a necklace-like molecule-based magnet, that gives a qualitative consistency.
Magnetic properties and thermodynamics of decorated Ising chain with pendants of arbitrary spin
International Nuclear Information System (INIS)
Li Wei; Gong Shoushu; Chen Ziyu; Zhao Yang; Su Gang
2010-01-01
The decorated Ising chain with pendants of arbitrary spin and the single-ion anisotropy is exactly solved by the transfer matrix method. The solutions reveal abundant novel properties than the conventional one-dimensional Ising model. It is compared with the experimental data of a necklace-like molecule-based magnet, that gives a qualitative consistency.
The thermodynamic and structural properties of metallocenes-type random ethylene copolymers
Energy Technology Data Exchange (ETDEWEB)
Simanke, Adriane G.; Mauler, Raquel S.; Galland, Griselda B. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Quimica]. E-mail: asimanke@portoweb.com.br; Alamo, Rufina G. [Florida State Univ., Tallahassee, FL (UNited States). College of Engineering. Dept. of Chemical Engineering]. E-mail: alamo@eng.fsu.edu
2001-07-01
The properties of a series of random ethylene copolymers prepared with the metallocenes catalytic system rac-Et[Ind]{sub 2} ZrCl{sub 2}/MAO were studied for a large variety of comonomer types. These include the classical 1-alkene type with length up to 10 carbons and those of the cyclic type such as cyclopentadiene and dicyclopentadiene. Under rapid crystallization, the melting temperatures of the newly synthesized copolymers followed the relation of model random copolymers indicating a behavior that conforms to that predicted by Flory's phase equilibrium theory. The molar entropy of fusion is not significantly altered by the comonomer type including the dicyclopentadiene type. All types of comonomers studied showed, for a fixed comonomer content, the same change in properties during annealing, except the ethylene 1-butenes. These latter copolymers and the hydrogenated poly butadiene showed a faster rate of change in thermal properties. This is consistent with a higher molecular diffusion for the butene comonomer than for the rest of comonomers analyzed. The properties of the inter lamellar region were also studied as a function of comonomer type and content following the variation of the amorphous halo extracted from the WAXS diffractograms. The observed systematic decrease in the peak scattering angle with increasing comonomer content indicates a variation of the intermolecular liquid structure. (author)
The thermodynamic and structural properties of metallocenes-type random ethylene copolymers
International Nuclear Information System (INIS)
Simanke, Adriane G.; Mauler, Raquel S.; Galland, Griselda B.; Alamo, Rufina G.
2001-01-01
The properties of a series of random ethylene copolymers prepared with the metallocenes catalytic system rac-Et[Ind] 2 ZrCl 2 /MAO were studied for a large variety of comonomer types. These include the classical 1-alkene type with length up to 10 carbons and those of the cyclic type such as cyclopentadiene and dicyclopentadiene. Under rapid crystallization, the melting temperatures of the newly synthesized copolymers followed the relation of model random copolymers indicating a behavior that conforms to that predicted by Flory's phase equilibrium theory. The molar entropy of fusion is not significantly altered by the comonomer type including the dicyclopentadiene type. All types of comonomers studied showed, for a fixed comonomer content, the same change in properties during annealing, except the ethylene 1-butenes. These latter copolymers and the hydrogenated poly butadiene showed a faster rate of change in thermal properties. This is consistent with a higher molecular diffusion for the butene comonomer than for the rest of comonomers analyzed. The properties of the inter lamellar region were also studied as a function of comonomer type and content following the variation of the amorphous halo extracted from the WAXS diffractograms. The observed systematic decrease in the peak scattering angle with increasing comonomer content indicates a variation of the intermolecular liquid structure. (author)
Shales: A review of their classifications, properties and importance ...
African Journals Online (AJOL)
Shales are important to the petroleum industry because of their usefulness as source rocks in petroleum generation, seals in petroleum traps and reservoirs. Problems associated with drilling oil/gas wells in shale formations include slow rate of penetration and wellbore instability. These problems are generally caused by ...
Energy Technology Data Exchange (ETDEWEB)
Murphy, R.W.
1994-12-01
Based on relevant material property data and previous model formulations, a magnetothermodynamic property map for gadolinium gallium garnet (Gd{sub 3}Ga{sub 5}O{sub 12}) was adapted for refrigeration cycle analysis in the temperature range 4-40 K and the magnetic field range 0-6 T. Employing methods similar to those previously developed for other materials and temperature ranges, assessments of limitations and relative performance were made for Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. It was found that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as the limitations for materials previously examined, considerable improvement in cooling capacity and temperature lift combinations can be achieved by using regenerative cycles if serious loss mechanisms are avoided.
The general theory of the mechanical, electromagnetic and thermodynamic properties of black holes
International Nuclear Information System (INIS)
Carter, B.
1979-01-01
The introductory section includes a brief account of the basic mathematical concept of a black hole in a general dynamical context. This is followed by a more detailed examination of the properties of the horizon with particular reference to situations in which the black hole is allowed to tend asymptotically towards a stationary final equilibrium state. A more specialized description is then provided of the properties of the horizon in an exactly stationary state. Quasi-stationary states are next considered. The mass of a black hole is discussed. The final section summarizes the results that provide the justification for the belief that a stationary, asymptotically flat black hole state is fully determined by its mass and angular momentum when external matter and fields are absent, or by its mass, angular momentum, and electric charge if electromagnetic fields are allowed for. (U.K.)
Bratberg, Johan
2005-01-01
The recent development of tool steels and high-speed steels has led to a significant increase in alloy additions, such as Co, Cr, Mo, N, V, and W. Knowledge about the phase relations in these multicomponent alloys, that is, the relative stability between different carbides or the solubility of different elements in the carbides and in the matrix phase, is essential for understanding the behaviour of these alloys in heat treatments. This information is also the basis for improving the properti...
International Nuclear Information System (INIS)
Faussurier, G.
1996-01-01
A new screened hydrogenic model is presented. The screening constants depend both on the principal n and orbital l quantum numbers. They have been obtained from numerical fits over a large data base containing ionization potentials and one-electron excitation energies of ions. A rapid and original method to compute the bound-bound and bound-free oscillator strengths is proposed. The discrete spectrum and the series continuum are connected by continuity, and the sum rules are respected. The screened hydrogenic average atom is well-adapted to describe multicharged ion plasmas in local thermodynamic equilibrium (LTE). Using the key principle of statistical mechanics, it is shown first that this model is properly defined and thermodynamically coherent. Secondly, a new method of detailed ionization stage accounting of a LTE plasma is explained. It can be used to reconstruct the distribution of integer charge states in such a plasma from any average atom model. The l -splitting allows one-electron transitions between two subshells with the same principal quantum number n. They may be of great importance when the Rosseland opacity is computed. Though, methods of classical statistical mechanics are required to calculate the distribution of the configurations around the average atom one and so to improve the spectral opacities. The splitting in integer ionic stages can be easily included. The formalism is tested by comparisons with theoretical and experimental results published in the literature. From the photoabsorption spectra encountered, the main results are the correct estimations of both the Rosseland opacity and the detailed charge degrees accounting. (author)
Energy Technology Data Exchange (ETDEWEB)
Starling, K.E.; Lee, L.L.; Kumar, K.H.
1981-01-01
During the first half year of this research program the following elements of research have been performed: (1) the development of an improved pure component data bank, including collection and processing of data which is 70% complete as to substance, (2) calculation of distillable coal fluid thermodynamic properties using a multiparameter corresponding states correlation, (3) application of the most general density-cubic equation of pure fluids and (4) initiation of research to extend the corresponding states correlation framework to polar fluids. Primary conclusions of the first phase of this research program are that the three parameter corresponding states correlation predicts lighter coal fluid properties to a reasonable level of accuracy, and that a cubic equation can predict pure fluid thermodynamic properties on par with non-cubic equations of state.
Molecular simulation of thermodynamic and transport properties for the H{sub 2}O+NaCl system
Energy Technology Data Exchange (ETDEWEB)
Orozco, Gustavo A.; Jiang, Hao; Panagiotopoulos, Athanassios Z., E-mail: azp@princeton.edu [Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Moultos, Othonas A.; Economou, Ioannis G. [Chemical Engineering Program, Texas A and M University at Qatar, P.O. Box 23874, Doha (Qatar)
2014-12-21
Molecular dynamics and Monte Carlo simulations have been carried out to obtain thermodynamic and transport properties of the binary mixture H{sub 2}O+NaCl at temperatures from T = 298 to 473 K. In particular, vapor pressures, liquid densities, viscosities, and vapor-liquid interfacial tensions have been obtained as functions of pressure and salt concentration. Several previously proposed fixed-point-charge models that include either Lennard-Jones (LJ) 12-6 or exponential-6 (Exp6) functional forms to describe non-Coulombic interactions were studied. In particular, for water we used the SPC and SPC/E (LJ) models in their rigid forms, a semiflexible version of the SPC/E (LJ) model, and the Errington-Panagiotopoulos Exp6 model; for NaCl, we used the Smith-Dang and Joung-Cheatham (LJ) parameterizations as well as the Tosi-Fumi (Exp6) model. While none of the model combinations are able to reproduce simultaneously all target properties, vapor pressures are well represented using the SPC plus Joung-Cheathem model combination, and all LJ models do well for the liquid density, with the semiflexible SPC/E plus Joung-Cheatham combination being the most accurate. For viscosities, the combination of rigid SPC/E plus Smith-Dang is the best alternative. For interfacial tensions, the combination of the semiflexible SPC/E plus Smith-Dang or Joung-Cheatham gives the best results. Inclusion of water flexibility improves the mixture densities and interfacial tensions, at the cost of larger deviations for the vapor pressures and viscosities. The Exp6 water plus Tosi-Fumi salt model combination was found to perform poorly for most of the properties of interest, in particular being unable to describe the experimental trend for the vapor pressure as a function of salt concentration.
International Nuclear Information System (INIS)
Leszczynski, J; Da Ros, V; Lenoir, B; Dauscher, A; Candolfi, C; Masschelein, P; Hejtmanek, J; Kutorasinski, K; Tobola, J; Smith, R I; Stiewe, C; Müller, E
2013-01-01
The thermoelectric and thermodynamic properties of polycrystalline In x Co 4 Sb 12 (0.0 ⩽ x ⩽ 0.26) skutterudites were investigated and analysed between 2 and 800 K by means of electrical resistivity, thermopower, thermal conductivity and specific heat measurements. Hall effect, sound velocity and thermal expansion measurements were also made in order to gain insights into the transport and elastic properties of these compounds. The impact of the In filling on the crystal structure as well as the thermal dynamics of the In atoms were tracked down to 4 K using powder neutron diffraction experiments. Analyses of the transport data were compared with the evolution of the electronic band structure with x determined theoretically within the Korringa–Kohn–Rostoker method with the coherent potential approximation. These calculations indicate that In gives rise to a remarkably large p-like density of states located at the conduction band edge. The electrical properties show typical trends of heavily doped semiconductors regardless of the In content. The thermal transport in CoSb 3 is strongly influenced by the presence of In in the voids of the crystal structure resulting in a drop in the lattice thermal conductivity values in the whole temperature range. The low value of the Grüneisen parameter suggests that this decrease mainly originates from enhanced mass-fluctuations and point-defect scattering mechanisms. The highest thermoelectric figure of merit ZT ∼ 1.0 at 750 K was achieved at the maximum In filling fraction, i.e. for x = 0.26. (paper)
Mei, Yuan; Liu, Weihua; Brugger, Joël; Sherman, David M.; Gale, Julian D.
2018-04-01
HCl is one of the most significant volatiles in the Earth's crust. It is well established that chloride activity and acidity (pH) play important roles in controlling the solubility of metals in aqueous hydrothermal fluids. Thus, quantifying the dissociation of HCl in aqueous solutions over a wide range of temperature and pressure is crucial for the understanding and numerical modeling of element mobility in hydrothermal fluids. Here we have conducted ab initio molecular dynamics (MD) simulations to investigate the mechanism of HCl(aq) dissociation and to calculate the thermodynamic properties for the dissociation reaction at 25-700 °C, 1 bar to 60 kbar, i.e. including high temperature and pressure conditions that are geologically important, but difficult to investigate via experiments. Our results predict that HCl(aq) tends to associate with increasing temperature, and dissociate with increasing pressure. In particular, HCl(aq) is highly dissociated at extremely high pressures, even at high temperatures (e.g., 60 kbar, 600-700 °C). At 25 °C, the calculated logKd values (6.79 ± 0.81) are close to the value (7.0) recommended by IUPAC (International Union of Pure and Applied Chemistry) and some previous experimental and theoretical studies (Simonson et al.., 1990; Sulpizi and Sprik, 2008, 2010). The MD simulations indicate full dissociation of HCl at low temperature; in contrast, some experiments were interpreted assuming significant association at high HCl concentrations (≥1 m HCltot) even at room T (logKd ∼0.7; e.g., Ruaya and Seward, 1987; Sretenskaya, 1992; review in Tagirov et al., 1997). This discrepancy is most likely the result of difficulties in the experimental determination of minor (if any) concentration of associated HCl(aq) under ambient conditions, and thus reflects differences in the activity models used for the interpretation of the experiments. With increasing temperature, the discrepancy between our MD results and previous experimental