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Top 20 Most Read Articles
August 2006
The 20 articles with the most full-text downloads during the month, in descending order.
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J. Phys. Chem. Ref. Data 31, 387 (2002); http://dx.doi.org/10.1063/1.1461829 (149 pages) Online Publication Date: 7 June 2002
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In 1995, the International Association for the Properties of Water and Steam (IAPWS) adopted a new formulation called “The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use”, which we abbreviate to IAPWS-95 formulation or IAPWS-95 for short. This IAPWS-95 formulation replaces the previous formulation adopted in 1984. This work provides information on the selected experimental data of the thermodynamic properties of water used to develop the new formulation, but information is also given on newer data. The article presents all details of the IAPWS-95 formulation, which is in the form of a fundamental equation explicit in the Helmholtz free energy. The function for the residual part of the Helmholtz free energy was fitted to selected data for the following properties: (a) thermal properties of the single-phase region (pρT) and of the vapor–liquid phase boundary (pσρ′ρ″T), including the phase-equilibrium condition (Maxwell criterion), and (b) the caloric properties specific isochoric heat capacity, specific isobaric heat capacity, speed of sound, differences in the specific enthalpy and in the specific internal energy, Joule–Thomson coefficient, and isothermal throttling coefficient. By applying modern strategies for optimizing the functional form of the equation of state and for the simultaneous nonlinear fitting to the data of all mentioned properties, the resulting IAPWS-95 formulation covers a validity range for temperatures from the melting line (lowest temperature 251.2 K at 209.9 MPa) to 1273 K and pressures up to 1000 MPa. In this entire range of validity, IAPWS-95 represents even the most accurate data to within their experimental uncertainty. In the most important part of the liquid region, the estimated uncertainty of IAPWS-95 ranges from ±0.001% to ±0.02% in density, ±0.03% to ±0.2% in speed of sound, and ±0.1% in isobaric heat capacity. In the liquid region at ambient pressure, IAPWS-95 is extremely accurate in density (uncertainty ⩽±0.0001%) and in speed of sound (±0.005%). In a large part of the gas region the estimated uncertainty in density ranges from ±0.03% to ±0.05%, in speed of sound it amounts to ±0.15% and in isobaric heat capacity it is ±0.2%. In the critical region, IAPWS-95 represents not only the thermal properties very well but also the caloric properties in a reasonable way. Special interest has been focused on the extrapolation behavior of the new formulation. At least for the basic properties such as pressure and enthalpy, IAPWS-95 can be extrapolated up to extremely high pressures and temperatures. In addition to the IAPWS-95 formulation, independent equations for vapor pressure, the densities, and the most important caloric properties along the vapor–liquid phase boundary, and for the pressure on the melting and sublimation curve, are given. Moreover, a so-called gas equation for densities up to 55 kg m−3 is also included. Tables of the thermodynamic properties calculated from the IAPWS-95 formulation are listed in the Appendix. © 2002 American Institute of Physics. |
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Evaluated Kinetic Data for Combustion Modeling: Supplement II J. Phys. Chem. Ref. Data 34, 757 (2005); http://dx.doi.org/10.1063/1.1748524 (641 pages) Online Publication Date: 27 July 2005
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This compilation updates and expands two previous evaluations of kinetic data on elementary, homogeneous, gas phase reactions of neutral species involved in combustion systems [J. Phys. Chem. Ref Data 21, 411 (1992); 23, 847 (1994)]. The work has been carried out under the auspices of the IUPAC Commission on Chemical Kinetics and the UK Engineering and Physical Sciences Research Council. Individual data sheets are presented for most reactions but the kinetic data for reactions of C2, C, ethyl, i-propyl, t-butyl, and allyl radicals are summarized in tables. Each data sheet sets out relevant thermodynamic data, experimental kinetic data, references, recommended rate parameters with their error limits and a brief discussion of the reasons for their selection. Where appropriate the data are displayed on an Arrhenius diagram or by fall-off curves. Tables summarizing the recommended rate data and the thermodynamic data for the reactant and product species are given, and their sources referenced. As in the previous evaluations the reactions considered relate largely to the combustion in air of organic compounds containing up to three carbon atoms and simple aromatic compounds. Thus the data base has been expanded, largely by dealing with a substantial number of extra reactions within these general areas. © 2005 American Institute of Physics. |
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IUPAC Critical Evaluation of Thermochemical Properties of Selected Radicals. Part I J. Phys. Chem. Ref. Data 34, 573 (2005); http://dx.doi.org/10.1063/1.1724828 (84 pages) Online Publication Date: 27 May 2005
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This is the first part of a series of articles reporting critically evaluated thermochemical properties of selected free radicals. The present article contains datasheets for 11 radicals: CH, CH2(triplet), CH2(singlet), CH3, CH2OH, CH3O, CH3CO, C2H5O, C6H5CH2, OH, and NH2. The thermochemical properties discussed are the enthalpy of formation, as well as the heat capacity, integrated heat capacity, and entropy of the radicals. One distinguishing feature of the present evaluation is the systematic utilization of available kinetic, spectroscopic and ion thermochemical data as well as high-level theoretical results. © 2005 American Institute of Physics. |
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Phase Change Enthalpies and Entropies of Liquid Crystals J. Phys. Chem. Ref. Data 35, 1051 (2006); http://dx.doi.org/10.1063/1.1901689 (280 pages) Online Publication Date: 17 July 2006
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The thermochemical behavior of more than 3000 organic compounds known to form liquid crystals is reported along with references to the original literature. A group additivity approach used to estimate total phase change entropies of organic molecules applied to 627 of these liquid crystals is found to significantly overestimate their total phase change entropies. Comparison of experimental and estimated values also show significant scatter relative to database compounds. The origins of these discrepancies are discussed in terms of a model used to explain liquid crystal formation.© 2006 American Institute of Physics. |
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Reference Equations of State for the Thermodynamic Properties of Fluid Phase n-Butane and Isobutane J. Phys. Chem. Ref. Data 35, 929 (2006); http://dx.doi.org/10.1063/1.1901687 (91 pages) Online Publication Date: 2 June 2006
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New formulations for the thermodynamic properties of fluid phase n-butane and isobutane in the form of fundamental equations explicit in the Helmholtz energy are presented. The functional form of the correlation equations for the residual parts was developed simultaneously for both substances considering data for the thermodynamic properties of ethane, propane, n-butane, and isobutane. Each contains 25 coefficients which were fitted to selected data for the thermal and caloric properties of the respective fluid both in the single-phase region and on the vapor–liquid phase boundary. This work provides information on the available experimental data for the thermodynamic properties of n- and isobutane, and presents all details of the new formulations. The new equations of state describe the pρT surfaces with uncertainties in density of 0.02% (coverage factor k = 2 corresponding to a confidence level of about 95%) from the melting line up to temperatures of 340 K and pressures of 12 MPa. The available reliable data sets in other regions are represented within their experimental uncertainties. The primary data, to which the equation for n-butane was fitted, cover the fluid region from the melting line to temperatures of 575 K and pressures of 69 MPa. The equation for isobutane was fitted to primary data that cover the fluid region from the melting line to temperatures of 575 K and pressures of 35 MPa. Beyond the range described by experimental data, the equations yield reasonable extrapolation behavior up to very high temperatures and pressures. In addition to the equations of state, independent equations for the vapor pressures, the saturated-liquid and saturated-vapor densities, and the melting pressures are given. Tables of thermodynamic properties calculated from the new formulations are listed in Appendix 2. Additionally, a preliminary equation of state for propane is presented that was developed in the course of the simultaneous optimization. This equation has the same functional form as the equations of state for n- and isobutane. © 2006 American Institute of Physics. |
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J. Phys. Chem. Ref. Data 35, 1331 (2006); http://dx.doi.org/10.1063/1.2201308 (34 pages) Online Publication Date: 8 August 2006
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Reference tables of second pVT-virial coefficients B(T), viscosity η(T), and self-diffusion ρD(T) are given for all neat alkanes CnH2n+2, n<6, for temperatures T ⩽ 1200 K starting at 100 K for CH4, 150 K for C2H6, and 180 K for C3H8, n-C4H10, i-C4H10, n-C5H12, i-C5H12, and C(CH3)4. Restricting ourselves to low densities the thermophysical properties are calculated by means of an isotropic (n-6) Lennard-Jones temperature dependent potential (LJTDP). In this model the potential well depth εeff(T) and the separation at minimum energy Rm(eff)(T) are explicitly temperature dependent, whereas the repulsive term n>12 is independent of T. The LJTDP has been used before in order to construct reference tables of thermophysical properties of neat gases [
Zarkova and Hohm, J. Phys. Chem. Ref. Data 31, 183 (2002)
] and binary mixtures [
Zarkova, Hohm, and Damyanova, J. Phys. Chem. Ref. Data 32, 1591 (2003)
]. However, those studies were restricted to atoms and globularly shaped nondipolar molecules. Here the approach is extended to elongated, not necessarily spherically symmetric, and in part slightly dipolar molecules. As in previous works the potential parameters ε(eff)(T), Rm(eff)(T), and n are determined by minimizing the root-mean-square deviation between calculated and experimentally obtained thermophysical properties B(T), η(T), ρD(T), and the second acoustic virial coefficient β(T) normalized to their experimental error. In extension of our previous efforts we present a thorough statistical analysis of the experimental input data which gives us the possibility to select primary data which could be used to build up a database.
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Cross Sections for Electron Collisions with Nitrogen Molecules J. Phys. Chem. Ref. Data 35, 31 (2006); http://dx.doi.org/10.1063/1.1937426 (23 pages) Online Publication Date: 8 December 2005
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Cross section data have been compiled for electron collisions with nitrogen molecules, based on 104 references. Cross sections are collected and reviewed for: total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, dissociation, ionization, and emission of radiation. For each process, the recommended values of the cross section are presented for use. The literature has been surveyed through the end of 2003.© 2006 American Institute of Physics. |
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J. Phys. Chem. Ref. Data 35, 785 (2006); http://dx.doi.org/10.1063/1.2132316 (54 pages) Online Publication Date: 27 April 2006
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The mutual solubility of C5–C26 hydrocarbons with seawater is exhaustively and critically reviewed. Reports of experimental determination of solubility in 46 chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For 15 of these systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. © 2006 American Institute of Physics. |
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J. Phys. Chem. Ref. Data 35, 687 (2006); http://dx.doi.org/10.1063/1.2132315 (98 pages) Online Publication Date: 27 April 2006
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The mutual solubilities and related liquid–liquid equilibria of C13–C36 hydrocarbons with water are exhaustively and critically reviewed. Reports of experimental determination of solubility in 56 chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For 17 systems sufficient data are available to allow critical evaluation. All 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, a new method based on the evaluation of all the experimental data for a given homologous series of aliphatic and aromatic hydrocarbons was used. © 2006 American Institute of Physics. |
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A New Equation of State for H2O Ice Ih J. Phys. Chem. Ref. Data 35, 1021 (2006); http://dx.doi.org/10.1063/1.2183324 (27 pages) Online Publication Date: 2 June 2006
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Various thermodynamic equilibrium properties of naturally abundant, hexagonal ice (ice Ih) of water (H2O) have been used to develop a Gibbs energy function g(T,p) of temperature and pressure, covering the ranges 0–273.16 K and 0 Pa–210 MPa, expressed in the temperature scale ITS-90. It serves as a fundamental equation from which additional properties are obtained as partial derivatives by thermodynamic rules. Extending previously developed Gibbs functions, it covers the entire existence region of ice Ih in the T-p diagram. Close to zero temperature, it obeys the theoretical cubic limiting law of Debye for heat capacity and Pauling’s residual entropy. It is based on a significantly enlarged experimental data set compared to its predecessors. Due to the inherent thermodynamic cross relations, the formulas for particular quantities like density, thermal expansion, or compressibility are thus fully consistent with each other, are more reliable now, and extended in their ranges of validity. In conjunction with the IAPWS-95 formulation for the fluid phases of water, the new chemical potential of ice allows an alternative computation of the melting and sublimation curves, being improved especially near the triple point, and valid down to 130 K sublimation temperature. It provides an absolute entropy reference value for liquid water at the triple point. © 2006 American Institute of Physics. |
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J. Phys. Chem. Ref. Data 35, 205 (2006); http://dx.doi.org/10.1063/1.1859286 (62 pages) Online Publication Date: 31 January 2006
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A new formulation for the thermodynamic properties of the fluid phase of ethane in the form of a fundamental equation explicit in the Helmholtz energy is presented. The functional form of the residual part was developed using state-of-the-art linear and nonlinear optimization algorithms. It contains 44 coefficients which were fitted to selected data for the thermal and caloric properties of ethane both in the single-phase region and on the liquid–vapor phase boundary. This work provides information on the available experimental data for the thermodynamic properties of ethane and presents all details of the new formulation. The new equation of state describes the pρT surface of ethane with an uncertainty in density of less than 0.02%–0.03% (coverage factor k = 2 corresponding to a level of confidence of about 95%) from the melting line up to temperatures of 520 K and pressures of 30 MPa. In the gaseous and supercritical region, high precision speed of sound data are represented generally within less than 0.015%. Other reliable data sets are represented within their experimental uncertainties. The primary data, to which the equation was fitted, cover the fluid region from the melting line to temperatures of 675 K and pressures of 900 MPa. Beyond this range the equation shows reasonable extrapolation behavior up to very high temperatures and pressures. In addition to the equation of state, independent equations for the vapor pressure, the saturated-liquid and saturated-vapor densities, and the melting pressure are given. Tables of thermodynamic properties calculated from the new formulation are listed in the Appendix.© 2006 American Institute of Physics. |
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Standard Reference Data for the Viscosity of Toluene J. Phys. Chem. Ref. Data 35, 1 (2006); http://dx.doi.org/10.1063/1.1928233 (8 pages) Online Publication Date: 22 November 2005
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Viscosity is an important transport property for the optimum design of a chemical process plant and for the development of molecular theories of the liquid state. A large amount of experimental viscosity data has been produced for all types of liquids, from alternative refrigerants to molten salts and molten metals. The accuracy of these data is related to the operating conditions of the instrument and, for this purpose as well as for the calibration of relative instruments, standard reference data for viscosity are necessary over a wide range of temperatures. New experimental data on the viscosity of liquid toluene along the saturation line have been obtained recently, mostly at low temperatures. The quality of the data is such that recommended values can be proposed with uncertainties of 0.5% (95% confidence level) for 260 K ⩽ T ⩽ 370 K and 2% for 210 K ⩽ T<260 K and 370 K<T ⩽ 400 K. A discussion about the uncertainties in the measurements and about the purity of the samples is made. The proposed value for the viscosity of liquid toluene at 298.15 K and 0.1 MPa is η = 554.2±3.3 μPa s. © 2006 American Institute of Physics. |
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A Reference Multiparameter Viscosity Equation for R134a with an Optimized Functional Form J. Phys. Chem. Ref. Data 35, 839 (2006); http://dx.doi.org/10.1063/1.2141635 (30 pages) Online Publication Date: 19 May 2006
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An optimization technique was applied to develop a functional form for a multiparameter viscosity equation η = η(ρ,T) for R134a. The results obtained are very promising, with an average absolute deviation of 0.55% for the currently available 549 primary data points. Compared to viscosity equations available in the literature, this is a significant improvement. Advantages become evident especially at gaseous states. As usual, both the development and the use of the viscosity equation require a highly accurate equation of state in order to convert the independent variables used for the experimental data and in most applications, (P,T), into the independent variables of the viscosity equation, (ρ,T). Though the equation was developed directly using the available data, the zero-density viscosity and the reduced second viscosity virial coefficient are correctly reproduced in the data range. The technique used to develop the equation, which is heuristic and not theoretically founded, is capable of selecting consistent data sets and thus is a powerful tool for screening the available experimental data. For the viscosity surface representation of a pure fluid this study shows that the limit in the achievement of a better accuracy is much more due to the present experimental uncertainty level for this property rather than to the effectiveness of the proposed modeling method. © 2006 American Institute of Physics. |
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Experimental Energy Levels of the Water Molecule J. Phys. Chem. Ref. Data 30, 735 (2001); http://dx.doi.org/10.1063/1.1364517 (97 pages)
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Experimentally derived energy levels are presented for 12248 vibration–rotation states of the H216O isotopomer of water, more than doubling the number in previous, disparate, compilations. For each level an error and reference to source data is given. The levels have been checked using energy levels derived from sophisticated variational calculations. These levels span 107 vibrational states including members of all polyads up to and including 8ν. Band origins, in some cases estimates, are presented for 101 vibrational modes. © 2001 American Institute of Physics. |
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Energy Levels and Observed Spectral Lines of Xenon, Xe I through Xe LIV J. Phys. Chem. Ref. Data 33, 765 (2004); http://dx.doi.org/10.1063/1.1649348 (157 pages) Online Publication Date: 25 August 2004
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The energy levels and observed spectral lines of the xenon atom, in all stages of ionization for which experimental data are available, have been compiled. Sufficient data were found to generate level and line tables for Xe I–Xe XI, Xe XIX, Xe XXV–Xe XXIX, Xe XLIII–Xe XLV, and Xe LI–Xe LIV. For Xe LIII and Xe LIV theoretical values are compiled for the energy levels. In 15 of the other stages a few lines are reported. Experimental g factors are included for Xe I, Xe II, and Xe III. A value, either experimental, semiempirical, or theoretical, is included for the ionization energy of each ion. © 2004 by the U.S. Secretary of Commerce on behalf of the United States. All rights reserved. |
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Vibrational and Electronic Energy Levels of Polyatomic Transient Molecules. Supplement B J. Phys. Chem. Ref. Data 32, 1 (2003); http://dx.doi.org/10.1063/1.1497629 (441 pages) Online Publication Date: 18 February 2003
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A summary is presented of recently published, critically evaluated experimental vibrational and electronic energy level data for approximately 1700 neutral and ionic transient molecules and high temperature species possessing from three to sixteen atoms. Although the emphasis is on species with lifetimes too short for study using conventional sampling techniques, there has been selective extension of the compilation to include data for isolated molecules of inorganic species such as the heavy-metal oxides, which are important in a wide variety of industrial chemical systems. Radiative lifetimes and the principal rotational constants are included. Observations in the gas phase, in molecular beams, and in rare-gas and diatomic molecule matrices are evaluated, and several thousand references are cited. The types of measurement surveyed include conventional and laser-based absorption and emission techniques, laser absorption with mass analysis, and photoelectron spectroscopy. © 2003 by the U.S. Secretary of Commerce on behalf of the United States. All rights reserved. |
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Reference Data for the Density and Viscosity of Liquid Aluminum and Liquid Iron J. Phys. Chem. Ref. Data 35, 285 (2006); http://dx.doi.org/10.1063/1.2149380 (16 pages) Online Publication Date: 10 February 2006
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The available experimental data for the density and viscosity of liquid aluminum and iron have been critically examined with the intention of establishing a density and a viscosity standard. All experimental data have been categorized into primary and secondary data according to the quality of measurement specified by a series of criteria. The proposed standard reference correlations for the density of the aluminum and iron are characterized by standard deviations of 0.65% and 0.77% at the 95% confidence level, respectively. The overall uncertainty in the absolute values of the density is estimated to be one of ±0.7% for aluminum and 0.8% for iron, which is worse than that of the most optimistic claims but recognizes the unexplained discrepancies between different methods. The standard reference correlations for the viscosity of aluminum and iron are characterized by standard deviations of 13.7% and 5.7% at the 95% confidence level, respectively. The uncertainty in the absolute values of the viscosity of the two metals is thought to be no larger than the scatter between measurements made with different techniques and so can be said to be ±14% in the case of aluminum and ±6% in the case of iron. © 2006 American Institute of Physics. |
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J. Phys. Chem. Ref. Data 29, 1 (2000); http://dx.doi.org/10.1063/1.556054 (39 pages)
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A correlation for estimating the vapor pressure of normal alkanes from methane through n-hexatriacontane and isomers of butane to nonane is reported. This work extends the correlation for normal alkanes (CnH2n+2), with n ⩽ 20, reported by Ambrose, to both normal alkanes with n ⩽ 36 and their isomers with n ⩽ 9. This vapor pressure equation was based on the Wagner equation and is similar to that used by Ambrose. Literature vapor pressure measurements have been reviewed. Tables are given that list the type of apparatus, measurement range and precision, and chemical purity. These criteria were initially used to select measurements for inclusion in the regression analyses to determine the coefficients of the correlation. Vapor pressures estimated from the correlation were compared with all vapor pressure (p1+g) measurements reviewed in this work. At pressures greater than 1 kPa, the vapor pressure equation presented here has the following accuracies: 0.0001⋅p1+g for methane, 0.001⋅p1+g for ethane, propane, and n-butane, 0.002⋅p1+g for n-pentane through n-octane, 2-methylpropane, and 2-methylbutane, 0.005⋅p1+g for 2,2-dimethylpropane, n-nonane, n-decane, and the isomers of hexane through nonane, 0.01⋅p1+g for n-undecane to n-hexadecane, 0.02⋅p1+g for n-heptadecane to n-eicosane, 0.05⋅p1+g for n-heneicosane to n-octacosane, and 0.10⋅p1+g for n-nonacosane to n-hexatriacontane. Equations for the critical temperatures and pressures of the normal alkanes as functions of the carbon number are also reported. © 2000 American Institute of Physics. |
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J. Phys. Chem. Ref. Data 33, 1083 (2004); http://dx.doi.org/10.1063/1.1835321 (29 pages) Online Publication Date: 25 January 2005
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A simple empirical equation is presented for the estimation of closed-cup flash points for pure organic liquids. Data needed for the estimation of a flash point (FP) are the normal boiling point (Teb), the standard enthalpy of vaporization at 298.15 K [ΔvapH°(298.15 K)] of the compound, and the number of carbon atoms (n) in the molecule. The bounds for this equation are: −100 ⩽ FP(°C) ⩽ +200; 250 ⩽ Teb(K) ⩽ 650; 20 ⩽ Δvap H°(298.15 K)/(kJ mol−1) ⩽ 110; 1 ⩽ n ⩽ 21. Compared to other methods (empirical equations, structural group contribution methods, and neural network quantitative structure–property relationships), this simple equation is shown to predict accurately the flash points for a variety of compounds, whatever their chemical groups (monofunctional compounds and polyfunctional compounds) and whatever their structure (linear, branched, cyclic). The same equation is shown to be valid for hydrocarbons, organic nitrogen compounds, organic oxygen compounds, organic sulfur compounds, organic halogen compounds, and organic silicone compounds. It seems that the flash points of organic deuterium compounds, organic tin compounds, organic nickel compounds, organic phosphorus compounds, organic boron compounds, and organic germanium compounds can also be predicted accurately by this equation. A mean absolute deviation of about 3 °C, a standard deviation of about 2 °C, and a maximum absolute deviation of 10 °C are obtained when predictions are compared to experimental data for more than 600 compounds. For all these compounds, the absolute deviation is equal or lower than the reproductibility expected at a 95% confidence level for closed-cup flash point measurement. This estimation technique has its limitations concerning the polyhalogenated compounds for which the equation should be used with caution. The mean absolute deviation and maximum absolute deviation observed and the fact that the equation provides unbiaised predictions lead to the conclusion that several flash points have been reported erroneously, whatever the reason, in one or several reference compilations. In the following lists, the currently accepted flash points for bold compounds err, or probably err, on the hazardous side by at least 10 °C and for the nonbolded compounds, the currently accepted flash points err, or probably err, on the nonhazardous side by at least 10 °C: bicyclohexyl, sec-butylamine, tert-butylamine, 2-cyclohexen-1-one, ethanethiol, 1,3-cyclohexadiene, 1,4-pentadiene, methyl formate, acetonitrile, cinnamaldehyde, 1-pentanol, diethylene glycol, diethyl fumarate, diethyl phthalate, trimethylamine, dimethylamine, 1,6-hexanediol, propylamine, methanethiol, ethylamine, bromoethane, 1-bromopropane, tert-butylbenzene, 1-chloro-2-methylpropane, diacetone alcohol, diethanolamine, 2-ethylbutanal, and formic acid. For some other compounds, no other data than the currently accepted flash points are available. Therefore, it cannot be assessed that these flash point data are erroneous but it can be stated that they are probably erroneous. At least, they need experimental re-examination. They are probably erroneous by at least 15 °C: 1,3-cyclopentadiene, di-tert-butyl sulfide, dimethyl ether, dipropyl ether, 4-heptanone, bis(2-chloroethyl)ether, 1-decanol, 1-phenyl-1-butanone, furan, ethylcyclopentane, 1-heptanethiol, 2,5-hexanediol, 3-hexanone, hexanoic acid methyl ester, 4-methyl-1,3-pentadiene, propanoyl chloride, tetramethylsilane, thiacyclopentane, 1-chloro-2-methyl-1-propene, trans-1,3-pentadiene, 2,3-dimethylheptane, triethylenetetramine, methylal, N-ethylisopropylamine, 3-methyl-2-pentene, and 2,3-dimethyl-1-butene. © 2005 American Institute of Physics. |
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Electron Interaction Cross Sections for CF3I, C2F4, and CFx (x = 1–3) Radicals J. Phys. Chem. Ref. Data 35, 267 (2006); http://dx.doi.org/10.1063/1.2149379 (18 pages) Online Publication Date: 10 February 2006
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The supply of absolute electron-impact cross sections for molecular targets and radicals is extremely important for developing plasma reactors and testing different types of etching gases. Current demand for such models is high as the industry aims to replace traditional plasma processing gases with less polluting species. New theoretical electron impact cross sections at typical etching plasma energies (sub 10 eV) are presented for the CFx (x = 1–3) active radical species in a form suitable for plasma modeling. The available experimental and theoretical data are summarized for two potential feed gases, CF3I and C2F4. This data cover recommended cross sections for electron scattering (total, excitation, momentum transfer, and elastic integral), electron impact dissociation, and dissociative electron attachment, wherever possible. Numerical values are given as tables in the paper and are also placed in the electronic archive. © 2006 American Institute of Physics. |
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