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Seiichiro Kagei - One of the best experts on this subject based on the ideXlab platform.
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measurement of Binary Diffusion Coefficient from impulse response curve having extremely low absorbance intensity under supercritical condition by noise elimination technique
Fluid Phase Equilibria, 2004Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Abstract A noise elimination technique was applied to the determination of Binary Diffusion Coefficients D 12 from the response curves having extremely low absorbance intensities in impulse response methods under supercritical conditions of carbon dioxide. The effectiveness of this technique was experimentally examined for the analyses of response curves through both the curve-fitting and the moment methods in two cases: the chromatographic impulse response method for phenol and β-carotene with a polymer-coated capillary column, and the Taylor dispersion method for acetone with an uncoated capillary column. Unreliable D 12 values were obtained from the moment method of the response curves at lower absorbance intensities, even treated with noise elimination. The curve-fitting method with the noise elimination treatment was quite effective for determining the D 12 values accurately, and was valid at the lowest absorbance intensities, on the order of 10 −4 absorbance unit of UV-Vis multi-detector, corresponding to the smallest quantity of the solute, i.e. 6×10 −5 , 6×10 −6 , and 5×10 −2 μ mol for phenol, β-carotene, and acetone, respectively, under conditions studied. Infinite dilution regions for Binary Diffusion Coefficients were obtained by injecting various amounts: the Binary Diffusion Coefficients showed constant values at concentrations less than 0.6, 0.004, and 0.08 mol m −3 for phenol, β-carotene, and acetone, respectively, in supercritical carbon dioxide at 313.2 K and 16–18 MPa.
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Binary Diffusion Coefficient partition ratio and partial molar volume for docosahexaenoic acid eicosapentaenoic acid and α linolenic acid at infinite dilution in supercritical carbon dioxide
Fluid Phase Equilibria, 2003Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Abstract A tracer response technique with a poly(ethylene glycol) coated capillary column was employed to measure Binary Diffusion Coefficient and partition ratio for the ω3 group of long chain unsaturated fatty acids such as docosahexaenoic acid, eicosapentaenoic acid and α-linolenic acid at infinite dilution in supercritical (SC) carbon dioxide at temperatures from 308.15 to 343.15 K and pressures from 9 to 30 MPa. The Binary Diffusion Coefficients for each solute were expressed with the Schmidt number correlation as well as the correlation with temperature and CO2 viscosity. The partition ratios were correlated with temperature and CO2 density. Moreover, the partial molar volumes were obtained from the partition ratios for each solute.
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measurements of Binary Diffusion Coefficient and partition ratio at infinite dilution for linoleic acid and arachidonic acid in supercritical carbon dioxide
Journal of Chemical & Engineering Data, 2003Co-Authors: Toshitaka Funazukuri, Takahiro Kikuchi, Chang Yi Kong, Seiichiro KageiAbstract:The Binary Diffusion Coefficient D12 and partition ratio k were measured for two ω6 group compounds, linoleic acid and arachidonic acid, at infinite dilution in carbon dioxide at temperatures from 308.15 K to 343.15 K and pressures from 9 MPa to 30 MPa by a tracer response technique with a poly(ethylene glycol)-coated capillary column. The measured D12 values were well represented by a correlation of D12/T versus CO2 viscosity and by the Schmidt number correlation for each solute, and the k values were well represented as a function of temperature and CO2 density. Partial molar volumes were also obtained from the k values.
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infinite dilution Binary Diffusion Coefficient partition ratio and partial molar volume for ubiquinone coq10 in supercritical carbon dioxide
Industrial & Engineering Chemistry Research, 2002Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Infinite-dilution Binary Diffusion Coefficient D12 and partition ratio k for ubiquinone CoQ10 in carbon dioxide were measured by a tracer response technique with a poly(ethylene glycol)-coated capillary column at temperatures from 308.15 to 333.15 K and pressures from 8.5 to 30 MPa. D12 and k values were simultaneously determined from a measured response curve by the curve-fitting method. The fitting error between measured and calculated response curves increased with decreasing pressure, as had been the case in our previous studies on various solutes in supercritical CO2 by the Taylor dispersion method. The D12 values were correlated with temperature and CO2 viscosity and the k values with temperature and CO2 density. Moreover, partial molar volumes of CoQ10 in supercritical CO2 were obtained from the k values.
Robert Hellmann - One of the best experts on this subject based on the ideXlab platform.
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First-Principles Calculation of the Cross Second Virial Coefficient and the Dilute Gas Shear Viscosity, Thermal Conductivity, and Binary Diffusion Coefficient of the (H2O + N2) System
Journal of Chemical & Engineering Data, 2019Co-Authors: Robert HellmannAbstract:The cross second virial Coefficient and the low-density shear viscosity, thermal conductivity, and Binary Diffusion Coefficient of mixtures of water (H2O) with nitrogen (N2) were obtained at temper...
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cross second virial Coefficient and dilute gas transport properties of the h2o co2 system from first principles calculations
Fluid Phase Equilibria, 2019Co-Authors: Robert HellmannAbstract:Abstract The cross second virial Coefficient and three dilute gas transport properties (shear viscosity, thermal conductivity, and Binary Diffusion Coefficient) of mixtures of water (H2O) and carbon dioxide (CO2) were calculated with high accuracy for temperatures up to 2000 K using statistical thermodynamics and the kinetic theory of molecular gases, respectively. The required intermolecular potential energy surface (PES) for the H2O–CO2 interaction is presented in this work, while the like-species interactions were modeled using PESs from the literature. All three PESs are based on high-level quantum-chemical ab initio computations. The predicted values for the cross second virial Coefficient are in satisfying agreement with the best experimental data. In the case of the transport properties, the calculated values should be more accurate than the few available data sets.
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ab initio intermolecular potential energy surface for the co2 n2 system and related thermophysical properties
Journal of Chemical Physics, 2018Co-Authors: Johannphilipp Crusius, Robert Hellmann, Juan Carlos Castropalacio, Velisa VesovicAbstract:A four-dimensional potential energy surface (PES) for the interaction between a rigid carbon dioxide molecule and a rigid nitrogen molecule was constructed based on quantum-chemical ab initio calculations up to the coupled-cluster level with single, double, and perturbative triple excitations. Interaction energies for a total of 1893 points on the PES were calculated using the counterpoise-corrected supermolecular approach and basis sets of up to quintuple-zeta quality with bond functions. The interaction energies were extrapolated to the complete basis set limit, and an analytical site-site potential function with seven sites for carbon dioxide and five sites for nitrogen was fitted to the interaction energies. The CO2-N2 cross second virial Coefficient as well as the dilute gas shear viscosity, thermal conductivity, and Binary Diffusion Coefficient of CO2-N2 mixtures were calculated for temperatures up to 2000 K to validate the PES and to provide reliable reference values for these important properties. The calculated values are in very good agreement with the best experimental data.
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intermolecular potential energy surface and thermophysical properties of the ch4 n2 system
Journal of Chemical Physics, 2014Co-Authors: Robert Hellmann, Eckard Bich, Eckhard Vogel, Velisa VesovicAbstract:A five-dimensional potential energy surface (PES) for the interaction of a rigid methane molecule with a rigid nitrogen molecule was determined from quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the CCSD(T) level of theory was utilized to compute a total of 743 points on the PES. The interaction energies were calculated using basis sets of up to quadruple-zeta quality with bond functions and were extrapolated to the complete basis set limit. An analytical site-site potential function with nine sites for methane and five sites for nitrogen was fitted to the interaction energies. The PES was validated by calculating the cross second virial Coefficient as well as the shear viscosity and Binary Diffusion Coefficient in the dilute-gas limit for CH4–N2 mixtures. An improved PES was obtained by adjusting a single parameter of the analytical potential function in such a way that quantitative agreement with the most accurate experimental values of the cross second virial Coefficient was achieved. The transport property values obtained with the adjusted PES are in good agreement with the best experimental data.
Toshitaka Funazukuri - One of the best experts on this subject based on the ideXlab platform.
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measurement of Binary Diffusion Coefficient and solubility estimation for dyes in supercritical carbon dioxide by cir method
Fluid Phase Equilibria, 2016Co-Authors: Toshitaka Funazukuri, Taichi Yamasaki, Minori Taguchi, Chang Yi KongAbstract:Abstract Infinite dilution Binary Diffusion Coefficients (D12) of two dyestuffs, disperse blue 14 (DB14) and disperse orange 11 (DO11), were measured in supercritical CO2 at 310–330 K and up to 35 MPa by the chromatographic impulse response (CIR) method and in liquid methanol and ethanol at 308–328 K and atmospheric pressure by the Taylor dispersion method. The retention factors (k) were also measured by the CIR method. The Diffusion Coefficients were well represented by a hydrodynamic equation, as a function of temperature and solvent viscosity, over a wide range of solvent viscosity from scCO2 to liquid solvents with average absolute relative deviations (AARDs) of 1.7% and 2.6% for 63 and 93 data points of DB14 and DO11, respectively. The solubility data for the two dyestuffs reported in the literature were well correlated with solute retention factor measured in the present study and solvent density with AARD of 7.05% for DB 14 of 109 data points and that of 15.4% for DO11 of 43 data points.
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measurement of Binary Diffusion Coefficient from impulse response curve having extremely low absorbance intensity under supercritical condition by noise elimination technique
Fluid Phase Equilibria, 2004Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Abstract A noise elimination technique was applied to the determination of Binary Diffusion Coefficients D 12 from the response curves having extremely low absorbance intensities in impulse response methods under supercritical conditions of carbon dioxide. The effectiveness of this technique was experimentally examined for the analyses of response curves through both the curve-fitting and the moment methods in two cases: the chromatographic impulse response method for phenol and β-carotene with a polymer-coated capillary column, and the Taylor dispersion method for acetone with an uncoated capillary column. Unreliable D 12 values were obtained from the moment method of the response curves at lower absorbance intensities, even treated with noise elimination. The curve-fitting method with the noise elimination treatment was quite effective for determining the D 12 values accurately, and was valid at the lowest absorbance intensities, on the order of 10 −4 absorbance unit of UV-Vis multi-detector, corresponding to the smallest quantity of the solute, i.e. 6×10 −5 , 6×10 −6 , and 5×10 −2 μ mol for phenol, β-carotene, and acetone, respectively, under conditions studied. Infinite dilution regions for Binary Diffusion Coefficients were obtained by injecting various amounts: the Binary Diffusion Coefficients showed constant values at concentrations less than 0.6, 0.004, and 0.08 mol m −3 for phenol, β-carotene, and acetone, respectively, in supercritical carbon dioxide at 313.2 K and 16–18 MPa.
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Binary Diffusion Coefficient partition ratio and partial molar volume for docosahexaenoic acid eicosapentaenoic acid and α linolenic acid at infinite dilution in supercritical carbon dioxide
Fluid Phase Equilibria, 2003Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Abstract A tracer response technique with a poly(ethylene glycol) coated capillary column was employed to measure Binary Diffusion Coefficient and partition ratio for the ω3 group of long chain unsaturated fatty acids such as docosahexaenoic acid, eicosapentaenoic acid and α-linolenic acid at infinite dilution in supercritical (SC) carbon dioxide at temperatures from 308.15 to 343.15 K and pressures from 9 to 30 MPa. The Binary Diffusion Coefficients for each solute were expressed with the Schmidt number correlation as well as the correlation with temperature and CO2 viscosity. The partition ratios were correlated with temperature and CO2 density. Moreover, the partial molar volumes were obtained from the partition ratios for each solute.
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measurements of Binary Diffusion Coefficient and partition ratio at infinite dilution for linoleic acid and arachidonic acid in supercritical carbon dioxide
Journal of Chemical & Engineering Data, 2003Co-Authors: Toshitaka Funazukuri, Takahiro Kikuchi, Chang Yi Kong, Seiichiro KageiAbstract:The Binary Diffusion Coefficient D12 and partition ratio k were measured for two ω6 group compounds, linoleic acid and arachidonic acid, at infinite dilution in carbon dioxide at temperatures from 308.15 K to 343.15 K and pressures from 9 MPa to 30 MPa by a tracer response technique with a poly(ethylene glycol)-coated capillary column. The measured D12 values were well represented by a correlation of D12/T versus CO2 viscosity and by the Schmidt number correlation for each solute, and the k values were well represented as a function of temperature and CO2 density. Partial molar volumes were also obtained from the k values.
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infinite dilution Binary Diffusion Coefficient partition ratio and partial molar volume for ubiquinone coq10 in supercritical carbon dioxide
Industrial & Engineering Chemistry Research, 2002Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Infinite-dilution Binary Diffusion Coefficient D12 and partition ratio k for ubiquinone CoQ10 in carbon dioxide were measured by a tracer response technique with a poly(ethylene glycol)-coated capillary column at temperatures from 308.15 to 333.15 K and pressures from 8.5 to 30 MPa. D12 and k values were simultaneously determined from a measured response curve by the curve-fitting method. The fitting error between measured and calculated response curves increased with decreasing pressure, as had been the case in our previous studies on various solutes in supercritical CO2 by the Taylor dispersion method. The D12 values were correlated with temperature and CO2 viscosity and the k values with temperature and CO2 density. Moreover, partial molar volumes of CoQ10 in supercritical CO2 were obtained from the k values.
Chang Yi Kong - One of the best experts on this subject based on the ideXlab platform.
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measurement of Binary Diffusion Coefficient and solubility estimation for dyes in supercritical carbon dioxide by cir method
Fluid Phase Equilibria, 2016Co-Authors: Toshitaka Funazukuri, Taichi Yamasaki, Minori Taguchi, Chang Yi KongAbstract:Abstract Infinite dilution Binary Diffusion Coefficients (D12) of two dyestuffs, disperse blue 14 (DB14) and disperse orange 11 (DO11), were measured in supercritical CO2 at 310–330 K and up to 35 MPa by the chromatographic impulse response (CIR) method and in liquid methanol and ethanol at 308–328 K and atmospheric pressure by the Taylor dispersion method. The retention factors (k) were also measured by the CIR method. The Diffusion Coefficients were well represented by a hydrodynamic equation, as a function of temperature and solvent viscosity, over a wide range of solvent viscosity from scCO2 to liquid solvents with average absolute relative deviations (AARDs) of 1.7% and 2.6% for 63 and 93 data points of DB14 and DO11, respectively. The solubility data for the two dyestuffs reported in the literature were well correlated with solute retention factor measured in the present study and solvent density with AARD of 7.05% for DB 14 of 109 data points and that of 15.4% for DO11 of 43 data points.
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measurement of Binary Diffusion Coefficient from impulse response curve having extremely low absorbance intensity under supercritical condition by noise elimination technique
Fluid Phase Equilibria, 2004Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Abstract A noise elimination technique was applied to the determination of Binary Diffusion Coefficients D 12 from the response curves having extremely low absorbance intensities in impulse response methods under supercritical conditions of carbon dioxide. The effectiveness of this technique was experimentally examined for the analyses of response curves through both the curve-fitting and the moment methods in two cases: the chromatographic impulse response method for phenol and β-carotene with a polymer-coated capillary column, and the Taylor dispersion method for acetone with an uncoated capillary column. Unreliable D 12 values were obtained from the moment method of the response curves at lower absorbance intensities, even treated with noise elimination. The curve-fitting method with the noise elimination treatment was quite effective for determining the D 12 values accurately, and was valid at the lowest absorbance intensities, on the order of 10 −4 absorbance unit of UV-Vis multi-detector, corresponding to the smallest quantity of the solute, i.e. 6×10 −5 , 6×10 −6 , and 5×10 −2 μ mol for phenol, β-carotene, and acetone, respectively, under conditions studied. Infinite dilution regions for Binary Diffusion Coefficients were obtained by injecting various amounts: the Binary Diffusion Coefficients showed constant values at concentrations less than 0.6, 0.004, and 0.08 mol m −3 for phenol, β-carotene, and acetone, respectively, in supercritical carbon dioxide at 313.2 K and 16–18 MPa.
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Binary Diffusion Coefficient partition ratio and partial molar volume for docosahexaenoic acid eicosapentaenoic acid and α linolenic acid at infinite dilution in supercritical carbon dioxide
Fluid Phase Equilibria, 2003Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Abstract A tracer response technique with a poly(ethylene glycol) coated capillary column was employed to measure Binary Diffusion Coefficient and partition ratio for the ω3 group of long chain unsaturated fatty acids such as docosahexaenoic acid, eicosapentaenoic acid and α-linolenic acid at infinite dilution in supercritical (SC) carbon dioxide at temperatures from 308.15 to 343.15 K and pressures from 9 to 30 MPa. The Binary Diffusion Coefficients for each solute were expressed with the Schmidt number correlation as well as the correlation with temperature and CO2 viscosity. The partition ratios were correlated with temperature and CO2 density. Moreover, the partial molar volumes were obtained from the partition ratios for each solute.
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measurements of Binary Diffusion Coefficient and partition ratio at infinite dilution for linoleic acid and arachidonic acid in supercritical carbon dioxide
Journal of Chemical & Engineering Data, 2003Co-Authors: Toshitaka Funazukuri, Takahiro Kikuchi, Chang Yi Kong, Seiichiro KageiAbstract:The Binary Diffusion Coefficient D12 and partition ratio k were measured for two ω6 group compounds, linoleic acid and arachidonic acid, at infinite dilution in carbon dioxide at temperatures from 308.15 K to 343.15 K and pressures from 9 MPa to 30 MPa by a tracer response technique with a poly(ethylene glycol)-coated capillary column. The measured D12 values were well represented by a correlation of D12/T versus CO2 viscosity and by the Schmidt number correlation for each solute, and the k values were well represented as a function of temperature and CO2 density. Partial molar volumes were also obtained from the k values.
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infinite dilution Binary Diffusion Coefficient partition ratio and partial molar volume for ubiquinone coq10 in supercritical carbon dioxide
Industrial & Engineering Chemistry Research, 2002Co-Authors: Toshitaka Funazukuri, Chang Yi Kong, Seiichiro KageiAbstract:Infinite-dilution Binary Diffusion Coefficient D12 and partition ratio k for ubiquinone CoQ10 in carbon dioxide were measured by a tracer response technique with a poly(ethylene glycol)-coated capillary column at temperatures from 308.15 to 333.15 K and pressures from 8.5 to 30 MPa. D12 and k values were simultaneously determined from a measured response curve by the curve-fitting method. The fitting error between measured and calculated response curves increased with decreasing pressure, as had been the case in our previous studies on various solutes in supercritical CO2 by the Taylor dispersion method. The D12 values were correlated with temperature and CO2 viscosity and the k values with temperature and CO2 density. Moreover, partial molar volumes of CoQ10 in supercritical CO2 were obtained from the k values.
Velisa Vesovic - One of the best experts on this subject based on the ideXlab platform.
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ab initio intermolecular potential energy surface for the co2 n2 system and related thermophysical properties
Journal of Chemical Physics, 2018Co-Authors: Johannphilipp Crusius, Robert Hellmann, Juan Carlos Castropalacio, Velisa VesovicAbstract:A four-dimensional potential energy surface (PES) for the interaction between a rigid carbon dioxide molecule and a rigid nitrogen molecule was constructed based on quantum-chemical ab initio calculations up to the coupled-cluster level with single, double, and perturbative triple excitations. Interaction energies for a total of 1893 points on the PES were calculated using the counterpoise-corrected supermolecular approach and basis sets of up to quintuple-zeta quality with bond functions. The interaction energies were extrapolated to the complete basis set limit, and an analytical site-site potential function with seven sites for carbon dioxide and five sites for nitrogen was fitted to the interaction energies. The CO2-N2 cross second virial Coefficient as well as the dilute gas shear viscosity, thermal conductivity, and Binary Diffusion Coefficient of CO2-N2 mixtures were calculated for temperatures up to 2000 K to validate the PES and to provide reliable reference values for these important properties. The calculated values are in very good agreement with the best experimental data.
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intermolecular potential energy surface and thermophysical properties of the ch4 n2 system
Journal of Chemical Physics, 2014Co-Authors: Robert Hellmann, Eckard Bich, Eckhard Vogel, Velisa VesovicAbstract:A five-dimensional potential energy surface (PES) for the interaction of a rigid methane molecule with a rigid nitrogen molecule was determined from quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the CCSD(T) level of theory was utilized to compute a total of 743 points on the PES. The interaction energies were calculated using basis sets of up to quadruple-zeta quality with bond functions and were extrapolated to the complete basis set limit. An analytical site-site potential function with nine sites for methane and five sites for nitrogen was fitted to the interaction energies. The PES was validated by calculating the cross second virial Coefficient as well as the shear viscosity and Binary Diffusion Coefficient in the dilute-gas limit for CH4–N2 mixtures. An improved PES was obtained by adjusting a single parameter of the analytical potential function in such a way that quantitative agreement with the most accurate experimental values of the cross second virial Coefficient was achieved. The transport property values obtained with the adjusted PES are in good agreement with the best experimental data.
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calculation of the Binary Diffusion Coefficient and interaction viscosity of the h h2 system
Chemical Physics, 2008Co-Authors: Velisa VesovicAbstract:Abstract It has been argued that the Mason–Monchick approximation (MMA) and infinite order sudden approximation (IOSA) are not suitable for the calculation of the transport property Coefficients of light polyatomic systems. It is proposed, on physical grounds, that a new approximation, the hybrid-MMA, is more appropriate. Although the hybrid-MMA belongs to the MMA/IOSA type methods, its accuracy is expected to decrease with increasing temperature. The hybrid-MMA was used to calculate the cross-sections that govern the Binary Diffusion Coefficient and the interaction viscosity of the H–H 2 system. The results were compared with the existing quantum IOSA calculations. The agreement is excellent for temperatures above 500 K. The present results were also compared with the ‘exact’ CC calculations. The agreement is very good below 1000 K, but progressively fails at elevated temperatures. The differences observed, with increasing temperature, can be attributed to a combination of the decreasing accuracy of a particular CC calculation and the expected failure of the MMA/IOSA family of methods when applied to light systems at high temperature.