Volume 35, Issue 4, December 2006
Index of content:
35(2006); http://dx.doi.org/10.1063/1.2201061View Description Hide Description
This study presents 95 recommended experimental and 180 calculated values of critical pressures for saturated and unsaturated aliphatic hydrocarbons. This is the third article in a series dealing with recommended critical data for organic compounds. Previously critically evaluated data on normal boiling temperatures based on recommended experimental data base is also given in this study.
35(2006); http://dx.doi.org/10.1063/1.2204959View Description Hide Description
A comprehensive database on physical properties of ionic liquids (ILs), which was collected from 109 kinds of literature sources in the period from 1984 through 2004, has been presented. There are 1680 pieces of data on the physical properties for 588 available ILs, from which 276 kinds of cations and 55 kinds of anions were extracted. In terms of the collected database, the structure-property relationship was evaluated. The correlation of melting points of two most common systems, disubstituted imidazolium tetrafluoroborate and disubstituted imidazolium hexafluorophosphate, was carried out using a quantitative structure-property relationship method.
35(2006); http://dx.doi.org/10.1063/1.2204960View Description Hide Description
A comprehensive critically evaluated compilation of the most accurate wavelength measurements for classified lines of neutral mercury for both the single isotope and for mercury in its natural isotopic abundance has been prepared. Data from 12 sources spanning the region from are included for . Data from 39 sources spanning the region from are included for the natural isotope mixture. Based on these line lists we have derived optimized values for the energy levels of neutral mercury for both and the natural isotopic mixture. Tabular data for 105 classified lines and 60 energy levels are provided for and 658 lines and 275 energy levels are provided for the natural isotopic mixture.
A Reference Multiparameter Thermal Conductivity Equation for Carbon Dioxide with an Optimized Functional Form35(2006); http://dx.doi.org/10.1063/1.2213631View Description Hide Description
A new thermal conductivityequation in a multiparameter format was developed for carbon dioxide through the application of an optimization technique of the functional form. The proposed equation is valid for temperatures from the triple point (; ) to and pressures up to . The calculation of density, which is an independent variable of the equation, from the experimental conditions is performed with a high accuracy equation of state for the fluid. The thermal conductivityequation shows an average absolute deviation of 1.19% on the selected 1407 primary data points. Its performances are slightly better than those of the corresponding conventional model by Vesovic et al. [J. Phys. Chem. Ref. Data19, 763 (1990)] available from the literature; moreover the new equation is simpler to use in particular for the near-critical region. Tables of generated values of carbon dioxidethermal conductivity are provided for check of the code implementations and for quick evaluations.
35(2006); http://dx.doi.org/10.1063/1.2336783View Description Hide Description
The recommended vapor–liquid equilibrium (VLE) data for binary mixtures of alkanols with alkenes and alkynes have been selected after critical evaluation of all data reported in the open literature up to the end of 2003. The evaluation procedure consisted in combining the thermodynamic consistency tests, data correlation, comparison with enthalpy of mixing data, and comparison of VLE data for various mixtures. The data were correlated with Wilson equation as well as with equation of state appended with chemical term (EoSC) proposed by Góral. The recommended data for 18 systems are presented in the form of individual pages containing tables of data, figures, and auxiliary information. Each page corresponds to one system and contains three isotherms (spaced by at least ) and one isobar (preferably at ). Experimental gaps were completed with the predicted data.
35(2006); http://dx.doi.org/10.1063/1.2360605View Description Hide Description
A new reference-quality correlation for the viscosity of methanol is presented that is valid over the entire fluid region, including vapor, liquid, and metastable phases. To describe the zero-density viscosity with kinetic theory for polar gases, a new expression for the collision integral of the Stockmayer potential is introduced. The initial density dependence is based on the Rainwater–Friend theory. A new correlation for the third viscosity virial coefficient is developed from experimental data and applied to methanol. The high-density contribution to the viscosity is based on the Chapman–Enskog theory and includes a new expression for the hard-sphere diameter that is a function of both temperature and density. The resulting correlation is applicable for temperatures from the triple point to at pressures up to . The estimated uncertainty of the resulting correlation (with a coverage factor of 2) varies from 0.6% in the dilute-gas phase between room temperature and , to less than 2% for the liquid phase at pressures up to at temperatures between 273 and , 3% for pressures from , 5% for the liquid from , and 10% between and . At very high pressures, from , the correlation has an estimated uncertainty of 30% and can be used to indicate qualitative behavior.
Temperature Dependences of Limiting Activity Coefficients, Henry’s Law Constants, and Derivative Infinite Dilution Properties of Lower 1-Alkanols in Water. Critical Compilation, Correlation, and Recommended Data35(2006); http://dx.doi.org/10.1063/1.2203355View Description Hide Description
A comprehensive review is presented of experimental data on the limiting activity coefficients , infinite dilution partial molar excess enthalpies and heat capacities of lower 1-alkanols in water. For each alkanol, the compiled data are critically evaluated and correlated with a suitable model equation providing adequate simultaneous description of the equilibrium measurements and the calorimetric information. As a result, recommended thermodynamically consistent temperature dependences of , , and of superior accuracy are established in the range from the melting point to the normal boiling point of water. In addition, by employing literature data on the respective residual properties of the pure 1-alkanols, analogous recommendations are also derived for the temperature dependences of the Henry’s law constants, hydration enthalpies, and hydration heat capacities. Evolution of the various infinite dilution thermodynamic properties of aqueous 1-alkanols with temperature and homologous series is briefly discussed.
35(2006); http://dx.doi.org/10.1063/1.2360606View Description Hide Description
Bone is a structurally complex material, formed of both organic and inorganic chemicals. The organic compounds constitute mostly collagen and other proteins. The inorganic or bone mineral components constitute predominantly calcium, phosphate, carbonate, and a host of minor ingredients. The mineralized bone is composed of crystals which are closely associated with a protein of which collagen is an acidic polysaccharide material. This association is very close and the protein integrates into the crystalline structure. The mineralization involves the deposition of relatively insoluble crystals on an organic framework. The solubility process takes place when the outermost ions in the crystal lattice breakaway from the surface and become separated from the crystal. This is characteristic for ions dissolving in water or aqueous solutions at the specified temperature. The magnitude of solubility is temperature and pH dependent. Bone is sparingly soluble in most solvents. Enamel is less soluble than bone and fluoroapatite is the least soluble of all apatites in acid buffers. Collagen is less soluble in neutral salt solution than in dilute acid solutions at ambient temperatures. The solubility of collagens in solvents gradually decreases with increasing age of the bone samples.
35(2006); http://dx.doi.org/10.1063/1.2218876View Description Hide Description
We have carried out a new, expanded tabulation of the atomic transition probabilities for allowed and forbidden lines of Fe I and Fe II, based on the critical evaluation of all available literature sources. The compiled data are taken mainly from recent experimental and theoretical results that became available after the publication of our first compilation in 1988. The data are arranged in multiplet format and are ordered according to increasing excitation energies.