Showing papers in "Journal of Physical and Chemical Reference Data in 2016"
TL;DR: A compendium of phase change enthalpies including fusion, vaporization, and sublimation was published in 2010 as mentioned in this paper, which included organic, organometallic, and a few inorganic compounds.
Abstract: A compendium of phase change enthalpies published in 2010 is updated to include the period 1880–2015. Phase change enthalpies including fusion, vaporization, and sublimation enthalpies are included for organic, organometallic, and a few inorganic compounds. Part 1 of this compendium includes organic compounds from C1 to C10. Part 2 of this compendium, to be published separately, will include organic and organometallic compounds from C11 to C192. Sufficient data are presently available to permit thermodynamic cycles to be constructed as an independent means of evaluating the reliability of the data. Temperature adjustments of phase change enthalpies from the temperature of measurement to the standard reference temperature, T = 298.15 K, and a protocol for doing so are briefly discussed.
191 citations
TL;DR: In this article, an empirical equation of state correlation is proposed for the Lennard-Jones model fluid based on a large molecular simulation data set and thermal virial coefficients, which is valid for temperatures 0.5 < T/Tc < 7 and pressures up to p/pc = 500.
Abstract: An empirical equation of state correlation is proposed for the Lennard-Jones model fluid. The equation in terms of the Helmholtz energy is based on a large molecular simulation data set and thermal virial coefficients. The underlying data set consists of directly simulated residual Helmholtz energy derivatives with respect to temperature and density in the canonical ensemble. Using these data introduces a new methodology for developing equations of state from molecular simulation. The correlation is valid for temperatures 0.5 < T/Tc < 7 and pressures up to p/pc = 500. Extensive comparisons to simulation data from the literature are made. The accuracy and extrapolation behavior are better than for existing equations of state.
125 citations
TL;DR: New, representative reference equations for the thermal conductivity of carbon dioxide are contained, based on a body of experimental data that has been critically assessed for internal consistency and for agreement with theory whenever possible, to extend the temperature range of the experimental data.
Abstract: This paper contains new, representative reference equations for the thermal conductivity of carbon dioxide. The equations are based in part upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory whenever possible. In the case of the dilute-gas thermal conductivity, we incorporated recent theoretical calculations to extend the temperature range of the experimental data. Moreover, in the critical region, the experimentally observed enhancement of the thermal conductivity is well represented by theoretically based equations containing just one adjustable parameter. The correlation is applicable for the temperature range from the triple point to 1100 K and pressures up to 200 MPa. The overall uncertainty (at the 95% confidence level) of the proposed correlation varies depending on the state point from a low of 1% at very low pressures below 0.1 MPa between 300 and 700 K, to 5% at the higher pressures of the range of validity.
45 citations
TL;DR: In this paper, the authors set up and manually curated a dataset containing experimental information on the impact of amino acid substitutions in a protein on its thermal stability, which consists of a repository of experimentally measured melting temperatures and their changes upon point mutations for proteins having a well-resolved x-ray structure.
Abstract: We have set up and manually curated a dataset containing experimental information on the impact of amino acid substitutions in a protein on its thermal stability. It consists of a repository of experimentally measured melting temperatures (Tm) and their changes upon point mutations (ΔTm) for proteins having a well-resolved x-ray structure. This high-quality dataset is designed for being used for the training or benchmarking of in silico thermal stability prediction methods. It also reports other experimentally measured thermodynamic quantities when available, i.e., the folding enthalpy (ΔH) and heat capacity (ΔCP) of the wild type proteins and their changes upon mutations (ΔΔH and ΔΔCP), as well as the change in folding free energy (ΔΔG) at a reference temperature. These data are analyzed in view of improving our insights into the correlation between thermal and thermodynamic stabilities, the asymmetry between the number of stabilizing and destabilizing mutations, and the difference in stabilization potential of thermostable versus mesostable proteins.
44 citations
TL;DR: In this article, a temperature-dependent ideal gas internal partition function, Qint(T), was derived for the H216O molecule for temperatures between 0 and 6000 K. Determination of QintT is principally based on the direct summation technique involving all accurate experimental energy levels known for h216O (almost 20,000 rovibrational energies including an almost complete list up to a relative energy of 7500 cm−1), augmented with a less accurate but complete list of first-principles computed energy levels up to the first dissociation limit, about 41
Abstract: A much improved temperature-dependent ideal-gas internal partition function, Qint(T), of the H216O molecule is reported for temperatures between 0 and 6000 K. Determination of Qint(T) is principally based on the direct summation technique involving all accurate experimental energy levels known for H216O (almost 20 000 rovibrational energies including an almost complete list up to a relative energy of 7500 cm−1), augmented with a less accurate but complete list of first-principles computed rovibrational energy levels up to the first dissociation limit, about 41 000 cm−1 (the latter list includes close to one million bound rovibrational energy levels up to J = 69, where J is the rotational quantum number). Partition functions are developed for ortho- and para-H216O as well as for their equilibrium mixture. Unbound rovibrational states of H216O above the first dissociation limit are considered using an approximate model treatment. The effect of the excited electronic states on the thermochemical functions is...
36 citations
TL;DR: In this article, the authors used simple lattice-dynamics models to reduce the isotherms to 0 K. The 0 K data are useful for generating wide-range equation of state models and for studying the stability of chemical compounds at high pressure.
Abstract: Most of the chemical elements have now been compressed close to or above 100 GPa (1 Mbar) pressure in diamond-anvil cells and the pressure–volume room-temperature isotherms have been measured. We collect these data and use simple lattice-dynamics models to reduce the isotherms to 0 K. We have extended the published work by making new diamond-anvil-cell measurements on Cr and Rh, and by conducting density-functional calculations on the elements Po, At, Rn, Fr, Ra, and Ac. The 0 K data are tabulated for all elements 1 ≤ Z ≤ 92 and 0 ≤ P ≤ 100 GPa. These data are useful for generating wide-range equation of state models and for studying the stability of chemical compounds at high pressure (“Megabar chemistry”). The tables presented here are intended to be reference thermodynamic tables for use in high-pressure research. Further experimental and theoretical work will be needed to extend the tables to higher pressure and to improve accuracy.
31 citations
TL;DR: A complete set of calculated vibration-rotation energies of 12C2H2 ( X ˜ 1 Σ g + ) is provided for all vibrational states up to 13,000 cm−1 and some at higher energies, with rotational (J) and vibrational angular momentum (l) quantum numbers such that 0 ≤ J ≤ 100 and 0 ≤ |l| ≤ 20, respectively as discussed by the authors.
Abstract: A complete set of calculated vibration–rotation energies of 12C2H2 ( X ˜ 1 Σ g + ) is provided for all vibrational states up to 13 000 cm−1 and some at higher energies, with rotational (J) and vibrational angular momentum (l) quantum numbers such that 0 ≤ J ≤ 100 and 0 ≤ |l| ≤ 20, respectively. The calculation is performed using a global effective Hamiltonian and related spectroscopic constants from the literature [B. Amyay et al., J. Mol. Spectrosc. 267, 80 (2011)], based on the polyad model. The numerical values of all related polyad matrix elements are also provided. The model and equations for the Hamiltonian matrix elements are gathered. The experimental acetylene database used for determining the parameters is listed.
27 citations
TL;DR: In this article, a new viscosity formulation for propane, using the reference equation of state for its thermodynamic properties by Lemmon et al., is presented, valid in the fluid region from the triple-point temperature to 650 K and pressures up to 100 MPa.
Abstract: A new viscosity formulation for propane, using the reference equation of state for its thermodynamic properties by Lemmon et al. [J. Chem. Eng. Data 54, 3141 (2009)] and valid in the fluid region from the triple-point temperature to 650 K and pressures up to 100 MPa, is presented. At the beginning, a zero-density contribution and one for the critical enhancement, each based on the experimental data, were independently generated in parts. The higher-density contributions are correlated as a function of the reciprocal reduced temperature τ = Tc/T and of the reduced density δ = ρ/ρc (Tc—critical temperature, ρc—critical density). The final formulation includes 17 coefficients inferred by applying a state-of-the-art linear optimization algorithm. The evaluation and choice of the primary data sets are detailed due to its importance. The viscosity at low pressures p ≤ 0.2 MPa is represented with an expanded uncertainty of 0.5% (coverage factor k = 2) for temperatures 273 ≤ T/K ≤ 625. The expanded uncertainty in...
24 citations
TL;DR: Energy levels, wavelengths, lifetimes, and hyperfine structure constants for the isotopes of the first and second spectra of radium, Ra I and Ra II, have been compiled in this article.
Abstract: Energy levels, wavelengths, lifetimes, and hyperfine structure constants for the isotopes of the first and second spectra of radium, Ra I and Ra II, have been compiled. Wavelengths and wavenumbers are tabulated for 226Ra and for other Ra isotopes. Isotope shifts and hyperfine structure constants of even and odd-A isotopes of neutral radium atom and singly ionized radium are included. Experimental lifetimes of the states for both neutral and ionic Ra are also added, where available. The information is beneficial for present and future experiments aimed at different physics motivations using neutral Ra and singly ionized Ra.
19 citations
TL;DR: In this article, the authors reviewed cross section data for electron collisions with nitric oxide, and recommended values of the cross section are determined, as far as possible, as well as possible.
Abstract: Cross section data are reviewed for electron collisions with nitric oxide. Collision processes considered are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, ionization, and dissociative electron attachment. After a survey of the literature (up to the end of 2015), recommended values of the cross section are determined, as far as possible.
19 citations
TL;DR: New, wide-range reference equations for the thermal conductivity of ethene and propene as a function of temperature and density are presented and uncertainty in the critical region is estimated to be much larger.
Abstract: New, wide-range reference equations for the thermal conductivity of ethene and propene as a function of temperature and density are presented. The equations are based in part upon a body of experimental data that have been critically assessed for internal consistency and for agreement with theory whenever possible. For ethene, we estimate the uncertainty (at the 95% confidence level) for the thermal conductivity from 110 to 520 K at pressures up to 200 MPa to be 5% for the compressed liquid and supercritical phases. For the low-pressure gas phase (to 0.1 MPa) over the temperature range 270–680 K, the estimated uncertainty is 4%. The correlation is valid from 110 to 680 K and up to 200 MPa, but it behaves in a physically reasonable manner down to the triple point and may be used at pressures up to 300 MPa, although the uncertainty will be larger in regions where experimental data were unavailable. In the case of propene, data are much more limited. We estimate the uncertainty for the thermal conductivity of propene from 180 to 625 K at pressures up to 50 MPa to be 5% for the gas, liquid, and supercritical phases. The correlation is valid from 180 to 625 K and up to 50 MPa, but it behaves in a physically reasonable manner down to the triple point and may be used at pressures up to 100 MPa, although the uncertainty will be larger in regions where experimental data were unavailable. For both fluids, uncertainties in the critical region are much larger, since the thermal conductivity approaches infinity at the critical point and is very sensitive to small changes in density.
TL;DR: This paper focuses on organic fatty (aliphatic, carboxylic, and polyfunctional) acids and proposes recommended correlations for 99 acids, providing mean absolute percentage deviations below 1.6% in all cases.
Abstract: In previous papers, we have proposed specific correlations to reproduce the surface tension values for several sets of fluids and for wide ranges of temperatures. In this paper, we focus our attention on organic fatty (aliphatic, carboxylic, and polyfunctional) acids. We have taken into account the available data and values in the DIPPR and DETHERM databases and also Wohlfarth and Wohlfarth’s (1997) book. In some cases we have also considered new data published elsewhere. All the data and values have been carefully filtered and subsequently fitted with the use of the model currently implemented in NIST’s REFPROP program, calculating two or four adjustable coefficients for each fluid. As a result, we propose recommended correlations for 99 acids, providing mean absolute percentage deviations below 1.6% in all cases.
TL;DR: In this article, a new correlation for the viscosity of meta-xylene is presented based upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory.
Abstract: A new correlation for the viscosity of meta-xylene is presented. The correlation is based upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory. It is applicable in the temperature range from 273 to 673 K at pressures up to 200 MPa. The overall uncertainty of the proposed correlation, estimated as the combined expanded uncertainty with a coverage factor of 2, varies from 1% for the viscosity at atmospheric pressure to 5% for the highest temperatures and pressures of interest. Tables of the viscosity, generated by the relevant equations, at selected temperatures and pressures, and along the saturation line, are provided.
TL;DR: The mutual solubilities and related liquid-liquid equilibria for 11 ternary systems of C1-C3 alcohols with aromatic hydrocarbons and water are exhaustively and critically reviewed in this paper.
Abstract: The mutual solubilities and related liquid–liquid equilibria for 11 ternary systems of C1–C3 alcohols with aromatic hydrocarbons and water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2012 are compiled. For nine systems, sufficient data are available (two or more independent determinations) to allow critical evaluation. All new data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, an additional criterion was used for each of the evaluated systems. These systems include one binary miscibility gap in the hydrocarbon + water subsystem. The binary tie lines were compared with the recommended values published previously.
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