Thermophysical and thermochemical properties

The thermochemical properties of the rare-earth orthophosphates [plus Sc(P04) and Y(P04)] have recently been investigated in detail by Ushakov et al. (2001). These workers obtained the formation enthalpies of 14 orthophosphates by using calorimetric techniques and found an almost linear dependence between the enthalpies of formation and the rare-earth radius, from La(P04) (-321.4 kJ/mol) to Lu(P04) (-236.9 kJ/mol) xenotime and pretulite were found to be consistent with this behavior as well. The structural transition from the xenotime structure to the monazite structure was not manifested in a significant discontinuity in the relatively linear trend in the enthalpies of formation. The complete results of these detailed thermochemical studies are tabulated in Ushakov et al. (2001). 

Compound Melting point rc) Liquid spectral emissivity (at 0.65 pm) 

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All these fuels belong to a group of high-energy-density fuels with compact molecular structure rendered by the presence of pentacyclic cages. They are stable and nonvolatile at room temperature and pressure. Three formulations are solid and the fourth is a viscous liquid. Their S3mthesis and molecular structure analysis that uses X-ray crystallographic methods have been described by Marchand [5, 6]. Their molecular structure and physical properties are presented briefly below. Measured thermophysical and thermochemical properties follow. 

A new class of pentacyclic HED fuels was analyzed and some thermophysical and thermochemical properties have been measured. The main findings were as follows ... 

Lee, A., C. K. Law, and A. Makino. 1989. Aerothermochemical studies of energetic liquid materials 3. Approximate determination of some thermophysical and thermochemical properties of organic azides. Combustion Flame 78 263-74. 

ThermoML (Frenkel et al. 2006) is a language for the storage and exchange of experimental, predicted, and critically evaluated thermophysical and thermochemical property data. The language aims to cover essentially all relevant properties, and it deals thoroughly with uncertainties (Chirico et al. 2003). The standard, which has been developed as an IUPAC project (2002-055-3-024) and become an IUPAC recommendation (Frenkel et al 2006), provides detailed controlled vocabulary for the field. Several high-profile journals already provide data in this format (http //trc. nist.gov/ThermoML.html), and if this trend continues in the future, introduction of ThermoML may be rightfully considered as one of the milestone achievements in the rich history of thermodynamics research. 

Chirico, R. D., Frenkel, M., and Diky, V. V. 2003. ThermoML an XML-based approach for storage and exchange of experimental and critically evaluated thermophysical and thermochemical property data. 2. Uncertainties. Journal of Chemical and Engineering Data 48 1344-1359, DOI 10.1021/je034088i. 

Refining by slag treatment is dependent on several parameters, such as reaction kinetics, diffusion of impurities, partition ratios, etc. Meanwhile, these parameters are dependent on the type of slag and its thermophysical and thermochemical properties. For example, viscosity, density, and interfacial properties affect the separation of slag from the metal and the duration of slag refining. 

Enthalpies and entropies of hydration, and standard-state enthalpies of formation, of monoatomic ions are discussed in this section. Thermophysical and thermochemical properties of condensed systems are found in sections 2.2 and 2.3. Standard-state entropies of ions are discussed in section 2.2.2. Free energies (reduction potentials, etc.) are discussed in section 2.4. 

The thermophysical and thermochemical properties of HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), RDX (1,3,5-trinitrohexahydro-1,3,5-triazine) and nitromethane at elevated pressures are of... 

Pyrolants based on calcium disihcide have been investigated by Cudzilo [34, 35,44, 45] and the author. The combustion of a pressed stoichiometric mixture is shown in Figure 8.36, which shows the development of steady-state combustion after ignition of the peUet by a butane torch. Some experimentally determined thermophysical and thermochemical properties of various CaSi2/PTFE based pyrolants are hsted in Table 8.14. 

L.J. Wang Experimental and modeling studies of the thermophysical and thermochemical properties of some slag systems (Sweden Royal Institute of Technology, 2009)... 

Sohal, M., Ebner, M., Sabharwall, P., Sharpe, P., 2010. Engineering Database of Liquid Salt Thermophysical and Thermochemical Properties. INL/EXT-10—18297 report, 70 pages, retrieved from http //www.inl.gov/technicalpublications/Documents/4502650. pdf (on 01.09.14). 

Qu L, Choy K-L, Thermophysical and thermochemical properties of new thermal barrier materials based on Dy203-Y203 co-doped zirconia. Ceramics International. 2014 40 11593-11599. 

The NIST Chemistry webBook (http //webbook.nist. gov/chemistry/) from the National Institute of Standards and Technology (formerly the National Bureau of Standards), lists up to 45 thermochemical, thermophysical, and ion energetics properties which are available for over 40,(XX) compounds. 

Thermodex An Index of Selected Thermodynamic and Physical Property Resources http // www.lib.utexas.edu/thermodex/ (accessedNovember 10,2011). ThermoDex from the Mallet Chemistry Library, University of Texas-Austin is a freely searchable index to printed and Web-based compilations of thermochemical and thermophysical data. The ThermoDex home page also provides a guide to Finding Thermodynamic Information/Where to Start, which lists some of the standard handbooks and proprietary databases that are not indexed as well as those that are indexed. Searches for compounds, or preferably compound types, linked to a specific physical property or properties, display a list of handbooks that may contain data of interest. Actual data values are not displayed. ThermoDex records include the book s title, a brief abstract defining the scope and arrangement, properties and types of compounds, etc. Web datasets include URL links. While based primarily on the holdings of UT-Austin s Mallet Chemistry Library, most of these resources will be available in most university and major industrial libraries. 

Unlike the 4f elements, for which sesquioxides are ubiquitous, only the sesquioxides of Ac and Pu through Es have been prepared. Sesquioxides of Th through Np are clearly thermodynamically unstable with respect to disproportionation to the metals and the much more stable dioxides. (Those of heavier actinides would be obtainable if their half-lives were much longer and nuclear yields more favorable.) An overview of known actinide oxides, and their enthalpies of formation and standard entropies, was given earlier in Table 14.9 although most of the actinide sesquioxides have been known since before 1970 (Am203 since before 1950), only in the past decade have thermophysical [98] and thermochemical [99] properties been determined. Since the optimum solvent for solution calorimetry of these sesquioxides is moderately concentrated hydrochloric acid, a systematic approach to the prediction of the enthalpies of formation of other sesquioxides is to devise a cycle yielding the enthalpy of solution in infinitely dilute add ... 

Thermochemical and thermophysical properties are suitable for the elucidation of the structure-performance relationships of surfactants in solutions. The measurement of, for instance, integral dilution enthalpies provides an appropriate experimental basis [50,51]. The concentration functions of the dilution enthalpies of ammonium dodecane 1-sulfonate (Fig. 29) show a distinct depen-... 

S. Yamanaka, K. Kurosaki, T. Maekawa, T. Matsuda, S. Kobayashi, and M. Uno, Thermochemical and Thermophysical Properties of Alkaline-earth Perovskites, Jour. Nucl. Mater., 344, 61 (2004). 

Considering the right-hand side of this equation as a simple mathematical function, it can be plotted versus (Sir). The left-hand side is known for a given metal it contains known thermochemical and thermophysical properties, thus (Sir) is determined. The mass of the oxide formed is greater than the mass of the metal consumed, consequently the original size of the metal that would be pyrophoric (rm) can be calculated from S, r and the physical properties of the oxide and metal and their molecular weights. These results have been presented in the... 

Bokreta M. (1992). Energetics of garnets Computational model of the thermochemical and thermophysical properties. Ph.D. diss., University of Philadelphia. 

NIST also maintains a website called the NIST Chemistry WebBook (http //webbook. nist.gov), which provides access to a broad array of data compiled under the Standard Reference Data Program. This site allows a search for thermochemical data for more than 7000 organic and small inorganic compounds, reaction thermochemistry data for over 8000 reactions, IR spectra for over 16,000 compounds, mass spectra for over 15,000 compounds, UV/VIS spectra for over 1600 compounds, electronic and vibrational spectra for over 5000 compounds, spectroscopic constants of over 600 diatomic molecules, ion energetics data for over 16,000 compounds, and thermophysical properties data for 74 selected fluids. The site allows general searches by formula, name, CAS registry number, author, and stracture and also a few specialized searches by properties like molar mass and vibrational energies. 

Journal of Chemical and Engineering Data — This bimonthly journal of the American Chemical Society publishes articles reporting original experimental measurements carried out under carefully controlled conditions. The main emphasis is on thermochemical and thermophysical properties. Review articles with evaluated data from the literature are also published, [pubs.acs.org/journals/jceaax/index.html]... 

The NIST Chemistry WebBook contains thermochemical data, reaction thermochemistry data, spectra, spectroscopic data, ion energetics data, thermophysical property data [150]. Several compilations of enthalpies of vaporization and sublimation measured by different means can be foxmd in the literature [3,151-154]. A compilation of bond dissociation energies of organic compounds has recently been published by Luo [155]. 

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