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Rabiyat G. Batyrova - One of the best experts on this subject based on the ideXlab platform.
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Isochoric Heat Capacity of near- and supercritical benzene and derived thermodynamic properties
Journal of Molecular Liquids, 2020Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, J. W. Magee, Ilmutdin M. AbdulagatovAbstract:Abstract As part of a continuing study of the critical and supercritical phenomena in fluids and fluid mixtures, one- (CV1) and two-phase (CV2) Isochoric Heat capacities, densities (ρS) and phase-transition temperatures (TS) of benzene were measured in the critical and supercritical regions. Measurements were made in the immediate vicinity of the liquid-gas phase transition and the critical points in order to accurately determine of the phase transition properties (TS,ρS,CV1, and CV2). The measurements cover the temperature range from (347 to 616) K for 10 liquid and vapor isochores between (265 and 653) kg·m−3 at pressure up to 7.5 MPa. The measurements were performed using a high-temperature, high-pressure, nearly constant-volume adiabatic calorimeter. The standard uncertainties of the density, temperature, and Isochoric Heat Capacity, CV, measurements are estimated to be 0.1%, 0.02 K, and 1.5%, respectively. The measured one- (CV1) and two-phase (CV2) Isochoric Heat capacities along the critical isochore and the saturated liquid (ρS') and vapor (ρS") densities near the critical point were used to accurately estimate the theoretically meaningful asymptotic critical amplitudes (A0±and B0) and related amplitudes for other properties (Γ0+, D0, ξ0), and their universal relations, A0+/A0−, A0+Γ0+B02, αA0+Γ0+B0−2, D0Γ0+B0δ−1, ξ 0 α A 0 + v C 1 / 3 . Saturated liquid and vapor densities (ρS′, ρS″) together with measured two-phase CV2 data were used to estimate the values of asymmetric parameters a3 (complete scaling parameter) and b2 of the coexistence curve singular diameter. Experimentally determined asymptotical critical amplitudes (A0±and B0 fluid-specific parameters) were used to check and confirm the predictive capability of the universal correlation in terms of their dependence on the acentric factor ω based on the generalized corresponding states principle. The measured values of two-phase CV2 as a function of the specific volume V along various isotherms were used to calculate second temperature derivatives of vapor pressure d 2 P S d T 2 and chemical potential d 2 μ d T 2 and to estimate the value of Yang-Yang anomaly strength parameter Rμ = − 0.683 for benzene. The contributions of the vapor pressure, C VP = V C T d 2 P S d T 2 , and the chemical potential, C Vμ = − T d 2 μ d T 2 , to the measured total two-phase CV2 were derived from the measurements.
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Thermodynamic Properties at Saturation Derived from Experimental Two-Phase Isochoric Heat Capacity of 1-Hexyl-3-methylimidazolium Bis[(trifluoromethyl)sulfonyl]imide.
International journal of thermophysics, 2016Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, Ilmutdin M. Abdulagatov, J. W. MageeAbstract:New measurements are reported for the Isochoric Heat Capacity of the ionic liquid substance 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C6mim][NTf2]). These measurements extend the ranges of our earlier study [N.G. Polikhronidi et al., Phys. Chem. Liq. 52, 657 (2014)] by 5 % of the compressed liquid density and by 75 kelvins. An adiabatic calorimeter was used to measure one-phase (CV1) liquid and two-phase (CV2) liquid + vapor Isochoric Heat capacities, densities (ρS ), and phase-transition temperatures (TS ) of the ionic liquid (IL) substance. The combined expanded uncertainty of the density ρ and Isochoric Heat Capacity CV measurements at the 95 % confidence level with a coverage factor of k = 2 is estimated to be 0.15 % and 3 %, respectively. Measurements are concentrated in the immediate vicinity of the liquid + vapor phase transition curve, in order to closely observe phase transitions. The present measurements and those of our earlier study are analyzed together, and are presented in terms of thermodynamic properties (TS, ρS, CV1 and CV2) evaluated at saturation and in terms of key derived thermodynamic properties Cp, CS, [Formula: see text], and [Formula: see text] on the liquid + vapor phase transition curve. A thermodynamic relation by Yang and Yang is used to confirm the internal consistency of measured two-phase Heat capacities CV2, which are observed to fall perfectly on a line as a function of specific volume at a constant temperature. The observed linear behavior is exploited to evaluate contributions to the quantity CV2 = f(V,T) from chemical potential [Formula: see text] and from vapor pressure [Formula: see text]. The physical nature and specific details of the temperature and specific volume dependence of the two-phase Isochoric Heat Capacity and some features of the other derived thermodynamic properties of IL at liquid saturation curve are considered in detail.
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yang yang critical anomaly strength parameter from the direct two phase Isochoric Heat Capacity measurements near the critical point
Fluid Phase Equilibria, 2016Co-Authors: I M Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract New technique of the Yang–Yang critical anomaly strength function, Rμ(T), determination from direct two-phase liquid ( C V2 ′ ) and vapor ( C V2 ″ ) Isochoric Heat Capacity and liquid (V′) and vapor (V″) specific volumes measurements at the saturation have been developed. Our measured two-phase (liquid and vapor) Isochoric Heat capacities ( C V2 ″ , C V2 ′ ) and liquid and vapor specific volumes (V″,V′) data at saturation near the critical point have been used to accurately determine the Yang–Yang anomaly strength parameter, Rμ(T = Tc) = Rμ0, for various molecular liquids. The derived values of the Yang–Yang critical anomaly strength function show trend to negative infinity near the critical point as predicted by the theory (Cerdeirina et al., 2015) based on compressible cell gas (CCG) model that obey complete scaling with pressure mixing. The physical nature and details of the temperature and the specific volume dependences of the CV2 and correct estimations of the contributions of various terms (chemical potential CVμ and vapor-pressure CVP) to the measured total two-phase Heat Capacity were discussed in terms of the Yang–Yang anomaly parameter.
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Internal pressure of liquids from the calorimetric measurements near the critical point
Journal of Molecular Liquids, 2016Co-Authors: Ilmutdin M. Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract A new relation between the internal pressure and Isochoric Heat Capacity jump of liquids along the coexistence curve near the critical point was found. Our previously reported one- and two-phase Isochoric Heat capacities and specific volumes at saturation were used to calculate internal pressure of molecular liquids (water, carbon dioxide, alcohols, n-alkanes, DEE, etc.).The internal pressure derived from the calorimetric measurements was compared with the values calculated from the reference (NIST, REFPROP) and crossover equations of state. Locus of the isothermal and Isochoric internal pressure maxima and minima was studied using calorimetric data and the reference and crossover equations of state near the critical point. The maximum of the internal pressure of light and heavy water around the temperature of 460 K along the liquid saturation curve was found. We also found very simple relation between the internal pressure, ΔPintsat, and Isochoric Heat Capacity, ΔCV, jumps near the critical point.
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Yang–Yang critical anomaly strength parameter from the direct two-phase Isochoric Heat Capacity measurements near the critical point
Fluid Phase Equilibria, 2016Co-Authors: Ilmutdin M. Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract New technique of the Yang–Yang critical anomaly strength function, Rμ(T), determination from direct two-phase liquid ( C V2 ′ ) and vapor ( C V2 ″ ) Isochoric Heat Capacity and liquid (V′) and vapor (V″) specific volumes measurements at the saturation have been developed. Our measured two-phase (liquid and vapor) Isochoric Heat capacities ( C V2 ″ , C V2 ′ ) and liquid and vapor specific volumes (V″,V′) data at saturation near the critical point have been used to accurately determine the Yang–Yang anomaly strength parameter, Rμ(T = Tc) = Rμ0, for various molecular liquids. The derived values of the Yang–Yang critical anomaly strength function show trend to negative infinity near the critical point as predicted by the theory (Cerdeirina et al., 2015) based on compressible cell gas (CCG) model that obey complete scaling with pressure mixing. The physical nature and details of the temperature and the specific volume dependences of the CV2 and correct estimations of the contributions of various terms (chemical potential CVμ and vapor-pressure CVP) to the measured total two-phase Heat Capacity were discussed in terms of the Yang–Yang anomaly parameter.
Ilmutdin M. Abdulagatov - One of the best experts on this subject based on the ideXlab platform.
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Isochoric Heat Capacity of near- and supercritical benzene and derived thermodynamic properties
Journal of Molecular Liquids, 2020Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, J. W. Magee, Ilmutdin M. AbdulagatovAbstract:Abstract As part of a continuing study of the critical and supercritical phenomena in fluids and fluid mixtures, one- (CV1) and two-phase (CV2) Isochoric Heat capacities, densities (ρS) and phase-transition temperatures (TS) of benzene were measured in the critical and supercritical regions. Measurements were made in the immediate vicinity of the liquid-gas phase transition and the critical points in order to accurately determine of the phase transition properties (TS,ρS,CV1, and CV2). The measurements cover the temperature range from (347 to 616) K for 10 liquid and vapor isochores between (265 and 653) kg·m−3 at pressure up to 7.5 MPa. The measurements were performed using a high-temperature, high-pressure, nearly constant-volume adiabatic calorimeter. The standard uncertainties of the density, temperature, and Isochoric Heat Capacity, CV, measurements are estimated to be 0.1%, 0.02 K, and 1.5%, respectively. The measured one- (CV1) and two-phase (CV2) Isochoric Heat capacities along the critical isochore and the saturated liquid (ρS') and vapor (ρS") densities near the critical point were used to accurately estimate the theoretically meaningful asymptotic critical amplitudes (A0±and B0) and related amplitudes for other properties (Γ0+, D0, ξ0), and their universal relations, A0+/A0−, A0+Γ0+B02, αA0+Γ0+B0−2, D0Γ0+B0δ−1, ξ 0 α A 0 + v C 1 / 3 . Saturated liquid and vapor densities (ρS′, ρS″) together with measured two-phase CV2 data were used to estimate the values of asymmetric parameters a3 (complete scaling parameter) and b2 of the coexistence curve singular diameter. Experimentally determined asymptotical critical amplitudes (A0±and B0 fluid-specific parameters) were used to check and confirm the predictive capability of the universal correlation in terms of their dependence on the acentric factor ω based on the generalized corresponding states principle. The measured values of two-phase CV2 as a function of the specific volume V along various isotherms were used to calculate second temperature derivatives of vapor pressure d 2 P S d T 2 and chemical potential d 2 μ d T 2 and to estimate the value of Yang-Yang anomaly strength parameter Rμ = − 0.683 for benzene. The contributions of the vapor pressure, C VP = V C T d 2 P S d T 2 , and the chemical potential, C Vμ = − T d 2 μ d T 2 , to the measured total two-phase CV2 were derived from the measurements.
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Thermodynamic Properties at Saturation Derived from Experimental Two-Phase Isochoric Heat Capacity of 1-Hexyl-3-methylimidazolium Bis[(trifluoromethyl)sulfonyl]imide.
International journal of thermophysics, 2016Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, Ilmutdin M. Abdulagatov, J. W. MageeAbstract:New measurements are reported for the Isochoric Heat Capacity of the ionic liquid substance 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C6mim][NTf2]). These measurements extend the ranges of our earlier study [N.G. Polikhronidi et al., Phys. Chem. Liq. 52, 657 (2014)] by 5 % of the compressed liquid density and by 75 kelvins. An adiabatic calorimeter was used to measure one-phase (CV1) liquid and two-phase (CV2) liquid + vapor Isochoric Heat capacities, densities (ρS ), and phase-transition temperatures (TS ) of the ionic liquid (IL) substance. The combined expanded uncertainty of the density ρ and Isochoric Heat Capacity CV measurements at the 95 % confidence level with a coverage factor of k = 2 is estimated to be 0.15 % and 3 %, respectively. Measurements are concentrated in the immediate vicinity of the liquid + vapor phase transition curve, in order to closely observe phase transitions. The present measurements and those of our earlier study are analyzed together, and are presented in terms of thermodynamic properties (TS, ρS, CV1 and CV2) evaluated at saturation and in terms of key derived thermodynamic properties Cp, CS, [Formula: see text], and [Formula: see text] on the liquid + vapor phase transition curve. A thermodynamic relation by Yang and Yang is used to confirm the internal consistency of measured two-phase Heat capacities CV2, which are observed to fall perfectly on a line as a function of specific volume at a constant temperature. The observed linear behavior is exploited to evaluate contributions to the quantity CV2 = f(V,T) from chemical potential [Formula: see text] and from vapor pressure [Formula: see text]. The physical nature and specific details of the temperature and specific volume dependence of the two-phase Isochoric Heat Capacity and some features of the other derived thermodynamic properties of IL at liquid saturation curve are considered in detail.
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Internal pressure of liquids from the calorimetric measurements near the critical point
Journal of Molecular Liquids, 2016Co-Authors: Ilmutdin M. Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract A new relation between the internal pressure and Isochoric Heat Capacity jump of liquids along the coexistence curve near the critical point was found. Our previously reported one- and two-phase Isochoric Heat capacities and specific volumes at saturation were used to calculate internal pressure of molecular liquids (water, carbon dioxide, alcohols, n-alkanes, DEE, etc.).The internal pressure derived from the calorimetric measurements was compared with the values calculated from the reference (NIST, REFPROP) and crossover equations of state. Locus of the isothermal and Isochoric internal pressure maxima and minima was studied using calorimetric data and the reference and crossover equations of state near the critical point. The maximum of the internal pressure of light and heavy water around the temperature of 460 K along the liquid saturation curve was found. We also found very simple relation between the internal pressure, ΔPintsat, and Isochoric Heat Capacity, ΔCV, jumps near the critical point.
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Yang–Yang critical anomaly strength parameter from the direct two-phase Isochoric Heat Capacity measurements near the critical point
Fluid Phase Equilibria, 2016Co-Authors: Ilmutdin M. Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract New technique of the Yang–Yang critical anomaly strength function, Rμ(T), determination from direct two-phase liquid ( C V2 ′ ) and vapor ( C V2 ″ ) Isochoric Heat Capacity and liquid (V′) and vapor (V″) specific volumes measurements at the saturation have been developed. Our measured two-phase (liquid and vapor) Isochoric Heat capacities ( C V2 ″ , C V2 ′ ) and liquid and vapor specific volumes (V″,V′) data at saturation near the critical point have been used to accurately determine the Yang–Yang anomaly strength parameter, Rμ(T = Tc) = Rμ0, for various molecular liquids. The derived values of the Yang–Yang critical anomaly strength function show trend to negative infinity near the critical point as predicted by the theory (Cerdeirina et al., 2015) based on compressible cell gas (CCG) model that obey complete scaling with pressure mixing. The physical nature and details of the temperature and the specific volume dependences of the CV2 and correct estimations of the contributions of various terms (chemical potential CVμ and vapor-pressure CVP) to the measured total two-phase Heat Capacity were discussed in terms of the Yang–Yang anomaly parameter.
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experimental study of the Isochoric Heat Capacity and liquid gas coexistence curve properties of sec butanol in the near and supercritical regions
Thermochimica Acta, 2014Co-Authors: L. M. Radzhabova, Ilmutdin M. Abdulagatov, Gennadii V Stepanov, Kurban A. ShakhbanovAbstract:Abstract One- and two-phase Isochoric Heat capacities (CV) and saturated liquid and vapor properties ( T S , ρ ′ S , ρ ″ S ) of sec-butanol in the wide temperature and density ranges including near- and supercritical conditions have been measured with a high-temperature and high-pressure nearly constant-volume adiabatic calorimeter. The measurements were made in the temperature range from 307 K to 551 K for 22 liquid and vapor isochores from 76.44 kg m−3 to 794.06 kg m−3. The Isochoric Heat Capacity jump (quasi-static thermograms) technique have been used to accurately measure of the phase transition parameters (TS, ρS) near the critical point. The total experimental uncertainty of density (ρ), temperature (T), and Isochoric Heat Capacity (CV) measurements at the 95% confidence level with a coverage factor of k = 2 were estimated to be 0.06%, 15 mK, and 2–3%, respectively. The critical temperature (TC = 535.95 ± 0.02 K) and the critical density (ρC = 276.40 ± 2 kg m−3) for sec-butanol were determined from the measured saturated properties (CVS,TS, ρS) near the critical point. The values of the asymptotical critical amplitude of the two-phase CV along the critical isochore A ¯ 0 − = 37.95 ) and saturated density (B0 = 1.7441) near the critical point have been calculate using the measured Isochoric Heat Capacity data. The measured two-phase liquid and vapor Isochoric Heat capacities at saturation and saturation liquid and vapor specific volumes (V′, V″) were used to calculate the values of second temperature derivatives of the vapor pressure and chemical potential near the critical point. The values of asymmetry parameters a3 = −0.3664 and b2 = −0.2527 of the coexistence curve diameter for sec-butanol were determined from the measured Heat Capacity and saturated density data near the critical point. A new technique of the Yang-Yang anomaly strength parameter (Rμ) determination from the direct simultaneously two-phase Isochoric Heat Capacity ( C ″ V 2 , C ′ V 2 ) and specific volumes (V″, V′) measurements at saturation have been proposed. The value of Yang-Yang anomaly strength parameter (Rμ = −0.59) for sec-butanol has been determined using the new technique.
N. G. Polikhronidi - One of the best experts on this subject based on the ideXlab platform.
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Isochoric Heat Capacity of near- and supercritical benzene and derived thermodynamic properties
Journal of Molecular Liquids, 2020Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, J. W. Magee, Ilmutdin M. AbdulagatovAbstract:Abstract As part of a continuing study of the critical and supercritical phenomena in fluids and fluid mixtures, one- (CV1) and two-phase (CV2) Isochoric Heat capacities, densities (ρS) and phase-transition temperatures (TS) of benzene were measured in the critical and supercritical regions. Measurements were made in the immediate vicinity of the liquid-gas phase transition and the critical points in order to accurately determine of the phase transition properties (TS,ρS,CV1, and CV2). The measurements cover the temperature range from (347 to 616) K for 10 liquid and vapor isochores between (265 and 653) kg·m−3 at pressure up to 7.5 MPa. The measurements were performed using a high-temperature, high-pressure, nearly constant-volume adiabatic calorimeter. The standard uncertainties of the density, temperature, and Isochoric Heat Capacity, CV, measurements are estimated to be 0.1%, 0.02 K, and 1.5%, respectively. The measured one- (CV1) and two-phase (CV2) Isochoric Heat capacities along the critical isochore and the saturated liquid (ρS') and vapor (ρS") densities near the critical point were used to accurately estimate the theoretically meaningful asymptotic critical amplitudes (A0±and B0) and related amplitudes for other properties (Γ0+, D0, ξ0), and their universal relations, A0+/A0−, A0+Γ0+B02, αA0+Γ0+B0−2, D0Γ0+B0δ−1, ξ 0 α A 0 + v C 1 / 3 . Saturated liquid and vapor densities (ρS′, ρS″) together with measured two-phase CV2 data were used to estimate the values of asymmetric parameters a3 (complete scaling parameter) and b2 of the coexistence curve singular diameter. Experimentally determined asymptotical critical amplitudes (A0±and B0 fluid-specific parameters) were used to check and confirm the predictive capability of the universal correlation in terms of their dependence on the acentric factor ω based on the generalized corresponding states principle. The measured values of two-phase CV2 as a function of the specific volume V along various isotherms were used to calculate second temperature derivatives of vapor pressure d 2 P S d T 2 and chemical potential d 2 μ d T 2 and to estimate the value of Yang-Yang anomaly strength parameter Rμ = − 0.683 for benzene. The contributions of the vapor pressure, C VP = V C T d 2 P S d T 2 , and the chemical potential, C Vμ = − T d 2 μ d T 2 , to the measured total two-phase CV2 were derived from the measurements.
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Thermodynamic Properties at Saturation Derived from Experimental Two-Phase Isochoric Heat Capacity of 1-Hexyl-3-methylimidazolium Bis[(trifluoromethyl)sulfonyl]imide.
International journal of thermophysics, 2016Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, Ilmutdin M. Abdulagatov, J. W. MageeAbstract:New measurements are reported for the Isochoric Heat Capacity of the ionic liquid substance 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C6mim][NTf2]). These measurements extend the ranges of our earlier study [N.G. Polikhronidi et al., Phys. Chem. Liq. 52, 657 (2014)] by 5 % of the compressed liquid density and by 75 kelvins. An adiabatic calorimeter was used to measure one-phase (CV1) liquid and two-phase (CV2) liquid + vapor Isochoric Heat capacities, densities (ρS ), and phase-transition temperatures (TS ) of the ionic liquid (IL) substance. The combined expanded uncertainty of the density ρ and Isochoric Heat Capacity CV measurements at the 95 % confidence level with a coverage factor of k = 2 is estimated to be 0.15 % and 3 %, respectively. Measurements are concentrated in the immediate vicinity of the liquid + vapor phase transition curve, in order to closely observe phase transitions. The present measurements and those of our earlier study are analyzed together, and are presented in terms of thermodynamic properties (TS, ρS, CV1 and CV2) evaluated at saturation and in terms of key derived thermodynamic properties Cp, CS, [Formula: see text], and [Formula: see text] on the liquid + vapor phase transition curve. A thermodynamic relation by Yang and Yang is used to confirm the internal consistency of measured two-phase Heat capacities CV2, which are observed to fall perfectly on a line as a function of specific volume at a constant temperature. The observed linear behavior is exploited to evaluate contributions to the quantity CV2 = f(V,T) from chemical potential [Formula: see text] and from vapor pressure [Formula: see text]. The physical nature and specific details of the temperature and specific volume dependence of the two-phase Isochoric Heat Capacity and some features of the other derived thermodynamic properties of IL at liquid saturation curve are considered in detail.
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yang yang critical anomaly strength parameter from the direct two phase Isochoric Heat Capacity measurements near the critical point
Fluid Phase Equilibria, 2016Co-Authors: I M Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract New technique of the Yang–Yang critical anomaly strength function, Rμ(T), determination from direct two-phase liquid ( C V2 ′ ) and vapor ( C V2 ″ ) Isochoric Heat Capacity and liquid (V′) and vapor (V″) specific volumes measurements at the saturation have been developed. Our measured two-phase (liquid and vapor) Isochoric Heat capacities ( C V2 ″ , C V2 ′ ) and liquid and vapor specific volumes (V″,V′) data at saturation near the critical point have been used to accurately determine the Yang–Yang anomaly strength parameter, Rμ(T = Tc) = Rμ0, for various molecular liquids. The derived values of the Yang–Yang critical anomaly strength function show trend to negative infinity near the critical point as predicted by the theory (Cerdeirina et al., 2015) based on compressible cell gas (CCG) model that obey complete scaling with pressure mixing. The physical nature and details of the temperature and the specific volume dependences of the CV2 and correct estimations of the contributions of various terms (chemical potential CVμ and vapor-pressure CVP) to the measured total two-phase Heat Capacity were discussed in terms of the Yang–Yang anomaly parameter.
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Internal pressure of liquids from the calorimetric measurements near the critical point
Journal of Molecular Liquids, 2016Co-Authors: Ilmutdin M. Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract A new relation between the internal pressure and Isochoric Heat Capacity jump of liquids along the coexistence curve near the critical point was found. Our previously reported one- and two-phase Isochoric Heat capacities and specific volumes at saturation were used to calculate internal pressure of molecular liquids (water, carbon dioxide, alcohols, n-alkanes, DEE, etc.).The internal pressure derived from the calorimetric measurements was compared with the values calculated from the reference (NIST, REFPROP) and crossover equations of state. Locus of the isothermal and Isochoric internal pressure maxima and minima was studied using calorimetric data and the reference and crossover equations of state near the critical point. The maximum of the internal pressure of light and heavy water around the temperature of 460 K along the liquid saturation curve was found. We also found very simple relation between the internal pressure, ΔPintsat, and Isochoric Heat Capacity, ΔCV, jumps near the critical point.
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Yang–Yang critical anomaly strength parameter from the direct two-phase Isochoric Heat Capacity measurements near the critical point
Fluid Phase Equilibria, 2016Co-Authors: Ilmutdin M. Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract New technique of the Yang–Yang critical anomaly strength function, Rμ(T), determination from direct two-phase liquid ( C V2 ′ ) and vapor ( C V2 ″ ) Isochoric Heat Capacity and liquid (V′) and vapor (V″) specific volumes measurements at the saturation have been developed. Our measured two-phase (liquid and vapor) Isochoric Heat capacities ( C V2 ″ , C V2 ′ ) and liquid and vapor specific volumes (V″,V′) data at saturation near the critical point have been used to accurately determine the Yang–Yang anomaly strength parameter, Rμ(T = Tc) = Rμ0, for various molecular liquids. The derived values of the Yang–Yang critical anomaly strength function show trend to negative infinity near the critical point as predicted by the theory (Cerdeirina et al., 2015) based on compressible cell gas (CCG) model that obey complete scaling with pressure mixing. The physical nature and details of the temperature and the specific volume dependences of the CV2 and correct estimations of the contributions of various terms (chemical potential CVμ and vapor-pressure CVP) to the measured total two-phase Heat Capacity were discussed in terms of the Yang–Yang anomaly parameter.
I M Abdulagatov - One of the best experts on this subject based on the ideXlab platform.
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yang yang critical anomaly strength parameter from the direct two phase Isochoric Heat Capacity measurements near the critical point
Fluid Phase Equilibria, 2016Co-Authors: I M Abdulagatov, N. G. Polikhronidi, Rabiyat G. BatyrovaAbstract:Abstract New technique of the Yang–Yang critical anomaly strength function, Rμ(T), determination from direct two-phase liquid ( C V2 ′ ) and vapor ( C V2 ″ ) Isochoric Heat Capacity and liquid (V′) and vapor (V″) specific volumes measurements at the saturation have been developed. Our measured two-phase (liquid and vapor) Isochoric Heat capacities ( C V2 ″ , C V2 ′ ) and liquid and vapor specific volumes (V″,V′) data at saturation near the critical point have been used to accurately determine the Yang–Yang anomaly strength parameter, Rμ(T = Tc) = Rμ0, for various molecular liquids. The derived values of the Yang–Yang critical anomaly strength function show trend to negative infinity near the critical point as predicted by the theory (Cerdeirina et al., 2015) based on compressible cell gas (CCG) model that obey complete scaling with pressure mixing. The physical nature and details of the temperature and the specific volume dependences of the CV2 and correct estimations of the contributions of various terms (chemical potential CVμ and vapor-pressure CVP) to the measured total two-phase Heat Capacity were discussed in terms of the Yang–Yang anomaly parameter.
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liquid liquid vapor liquid liquid and liquid vapor phase transitions in aqueous n hexane mixtures from Isochoric Heat Capacity measurements
Journal of Chemical & Engineering Data, 2001Co-Authors: Ibragimkhan K. Kamilov, Gennadii V Stepanov, I M Abdulagatov, And Anvar R. Rasulov, Elena I. MilikhinaAbstract:The constant volume and constant composition Heat Capacity CVX data for aqueous n-hexane mixtures are reported for seven compositions, (0.6146, 0.7965, 0.9349, 0.9775, 0.9858, 0.9892, and 0.9940) mol fraction of n-hexane, along seven near-critical isochores between 259.34 and 312.50 kg·m-3 in the temperature range from 463 to 522 K at pressures up to 6 MPa. All of these isochores display two features in the Heat Capacity as a function of temperature: the first peak appears when one of the liquid phases disappears, and the second peak appears when the vapor or liquid phase disappears. These features are interpreted in terms of the liquid−liquid−vapor, liquid−liquid, and liquid−vapor phase diagram, and their consistency is shown with earlier PTx measurements on the three-phase (L-L-G) boundary. Measurements of the Isochoric Heat Capacity (CVVTx) of water + n-hexane mixtures were made in a spherical high-temperature, high-pressure nearly constant volume adiabatic calorimeter. The calorimeter was also used a...
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two phase Isochoric Heat Capacity measurements for nitrogen tetroxide in the critical region and yang yang relation
International Journal of Thermophysics, 2000Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, I M AbdulagatovAbstract:The two-phase Isochoric Heat Capacity of nitrogen tetroxide was measured in the temperature range from 261.74 K to the critical temperature (431.072 K) at densities between 201.21 and 1426.5 kg·m−3 using a high-temperature and high-pressure adiabatic calorimeter. The measurements were performed in the two-phase region for 26 isochores (15 liquid and 11 vapor densities) including the coexistence curve and critical region. Uncertainties of the measurements are estimated to be 2%. The original temperatures and CV data were converted to the ITS-90. The liquid and vapor two-phase Isochoric Heat capacities, temperatures, and densities at saturation were extracted from experimental data for each measured isochore. From measured (TS, ρS, C′V2, C″V2) data, the values of second temperature derivatives of vapor-pressure d2PS/dT2 and chemical potential d2μ/dT2 were derived using the Yang–Yang relation. The results were compared with values calculated from other vapor-pressure equations. The values of saturated densities and critical parameters derived in calorimetric experiments were compared with literature data. The unusual temperature behavior of d2PS/dT2 and d2μ/dT2 was found at low temperatures around 351 K and near the critical point.
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one and two phase Isochoric Heat Capacity measurements of aqueous solution of nacl near the critical point of pure water
Canadian Journal of Chemical Engineering, 2000Co-Authors: I M Abdulagatov, V. I. Dvoryanchikov, A.n. Kamalov, Elena G. Abramova, Madina A. AbdurashidovaAbstract:Isochoric Heat capacities of H2O+NaCl solutions (0.0031 and 0.0063 mole fraction of NaCl) were measured with a high temperature and high pressure adiabatic calorimeter near the sub-critical and near the supercritical point of pure water. Temperatures ranged from 361 to 677 K. Measurements were made at six densities, namely: 367.07 and 485.59 kg·m−3 for x = 0.0031 mol fraction of NaCl and 388.65, 560.03, 607.05, and 973.70 kg·m−3 for x = 0.0063 mol fraction of NaCl. Measurements were conducted in the two-and one-phase regions including near phase transition temperatures TS(ρ). The phase transition temperatures TS(ρ) and saturated Isochoric Heat Capacity values CVX have been determined for each isochore. The uncertainty in Heat Capacity measurements is estimated to be 3.5% to 4.5% near the phase transition and critical points. Present and previous results of Heat Capacity measurements were compared with predictions from the crossover (CREOS) and Pitzer—Tanger–Hovey equations of state (PTH EOS). Our previous Heat Capacity measurements were found to deviate systematically from crossover-model predictions. The present results show good agreement with the crossover model for the composition x = 0.0031 mol fraction. Le pouvoir calorifique isochore de solutions de H2O+NaCl (fraction molaire du NaCl de 0,0031 et 0,0063) a ete mesure a l'aide d'un calorimetre adiabatique a temperature et a pression elevees pres des points sous-critique et supercritique de l'eau pure. Les temperatures variaient entre 361 et 677 K. Des mesures ont ete effectuees a six masses volumiques, soient: 367,07 et 485,59 kg·m−3 pour une fraction molaire de NaCl de x = 0,0031 et 388,65, 560,03, 607,05 et 973,70 kg·m−3 pour une fraction molaire de NaCl de x = 0,0063. Les mesures ont ete prises dans les regions biphasique et monophasique, y compris pres des temperatures de transition de phase TS(ρ). Les temperatures de transition de phase TS(ρ) et les valeurs du pouvoir calorifique isochore sature CVX ont ete determinees pour chaque isochore. L'incertitude dans les mesures de pouvoir calorifique est estimee a 3,5–4,5% pres de la transition de phase et des points critiques. Les resultats actuels et anterieurs des mesures de pouvoir calorifique ont ete compares avec les predictions des equations d'etat de croisement (CREOS) et de Pitzer—Tanger–Hovey (PTH EOS). On a trouve que nos mesures de pouvoir calorifique anterieures s'ecartaient systematiquement des predictions de modele de croisement. Les resultats actuels concordent bien avec le modele de croisement pour la fraction molaire de composition de x = 0,0031.
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Isochoric Heat Capacity of xh2o 1 x koh near the critical point of pure water
The Journal of Chemical Thermodynamics, 1993Co-Authors: I M Abdulagatov, V. I. DvoryanchikovAbstract:Abstract The Isochoric Heat Capacity of {xH2O + (1-x)KOH} has been measured with a high-temperature adiabatic calorimeter. The experiments have been performed at five mole fractions x, namely 0.99973, 0.99863, 0.99725, 0.99166, and 0.98595. For each mole fraction the measurements have been performed at two isochores, namely 315.5 kg·m-3 (critical isochore for pure water) and 250.0 kg·m-3. The experimental results were obtained along isochores. The Cv for the saturated liquid [xH2O + (1-x)KOH} was determined by using an extrapolation technique along each isochore fitting a simple polynomial by least squares. The total error of each experimental value of Cv is estimated to be about 0.5 per cent in the region far from the critical point, and (1.5 to 2.0) per cent in its vicinity. The uncertainly of the densities measured was estimated to be within 0.03 kg·m-3. The uncertainly in temperature was less than 10 mK.
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Isochoric Heat Capacity of an n-hexane + water system
Russian Journal of Physical Chemistry A, 2015Co-Authors: E. I. Bezgomonova, S. M. Saidov, G. V. StepanovAbstract:The Isochoric Heat Capacity of an n -hexane + water system at water contents of 0.121, 0.166, 0.2, 0.234, 0.256, and 0.3 mole fraction is studied along different isochors at different temperatures in the 140 to 550 kg/m^3 range of densities using a high-temperature adiabatic calorimeter designed at the Amirkhanov Institute of Physics. The tabulated values of Isochoric Heat Capacity C _v, x are presented for an H_2O concentration of 0.3 mole fraction. The curves of liquid-liquid and liquid-gas phase equilibria are constructed.
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Experimental study of the Isochoric Heat Capacity and coexistence-curve singular diameter of sec-butanol near the critical point and Yang-Yang anomaly strength
Physics and Chemistry of Liquids, 2013Co-Authors: L. M. Radzhabova, G. V. Stepanov, Ilmutdin M. Abdulagatov, Kurban A. ShakhbanovAbstract:One- and two-phase Isochoric Heat capacities ( ) and saturated liquid and vapour densities ( , and ) of sec-butanol near the critical point have been measured with a high-temperature and high-pressure nearly constant-volume adiabatic calorimeter. The measurements were made in the temperature range from 307 K to 551 K for 22 liquid and vapour isochores from 76.44 to 794.06 kg m−3. The Isochoric Heat Capacity jump (quasi-static thermograms supplemented by the sensor of adiabatic control) technique have been used to accurately measure of the phase transition parameters ( ) near the critical point. The total experimental uncertainty of density ( ), temperature ( ) and Isochoric Heat Capacity ( ) measurements were estimated to be 0.06%, 15 mK and 2–3%, respectively. The critical temperature ( = 535.95 ± 0.02 K) and the critical density ( = 276.40 ± 2 kg m−3) for sec-butanol were determined from the measured saturated properties ( , ) near the critical point. The measured and saturated density ( ) data near...
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Experimental study of the Isochoric Heat Capacity of isobutanol in the critical and supercritical regions
The Journal of Supercritical Fluids, 2012Co-Authors: L. M. Radzhabova, G. V. Stepanov, Ilmutdin M. Abdulagatov, Kurban A. ShakhbanovAbstract:Abstract The one- and two-phase Isochoric Heat capacities ( C V ) of isobutanol in the critical and supercritical regions have been measured with a high-temperature and high-pressure nearly constant-volume adiabatic calorimeter. The measurements were made in the temperature range from 324 K to 575 K for 23 isochores (16 liquid and 7 vapor) from 73.2 kg m −3 to 772.2 kg m −3 . The Isochoric Heat Capacity jump (quasi-static thermograms supplemented by the sensor of adiabatic control) technique have been used to accurately measure of the phase transition parameters ( T S , ρ S ). The total experimental uncertainty of density ( ρ ), temperature ( T ), and Isochoric Heat Capacity ( C V ) were estimated to be 0.06%, 15 mK, and 2–3%, respectively. The critical temperature ( T C = 547.65 ± 0.2 K) and the critical density ( ρ C = 272.95 ± 2 kg m −3 ) for isobutanol were determined from the measured saturated properties ( C VS , T S , ρ S ) near the critical point. The measured C V and saturated density ( T S , ρ S ) data near the critical point have been analyzed and interpreted in terms of extended scaling type equations for the selected thermodynamic paths (critical isochore and coexistence curve) to accurately calculate the values of the asymptotical critical amplitudes of Heat Capacity ( A 0 ± ) and coexistence curve ( B 0 ). The experimentally derived value of the critical amplitude ratio A 0 + / A 0 − = 0.522 is in good agreement with the value predicted by various scaling theories. The measured thermodynamic properties ( C V , T S , ρ S ) of isobutanol near the critical point were also interpreted in the terms of “complete scaling” theory of critical phenomena. In particularly, the contributions of the “complete” and “incomplete” scaling terms on the coexistence-curve singular diameter were estimated. We determined the values of the asymmetry parameters a 3 and b 2 of the coexistence curve singular diameter. The strength of the Yang–Yang anomaly R μ for isobutanol was estimated using asymmetry parameters a 3 and the contribution of the second temperature derivative of vapor-pressure and chemical potential in the singularity of two-phase C V2 . The measured values of saturated one- and two-phase liquid and vapor Isochoric Heat capacities ( C ′ V 1 , C ″ V 1 , C ′ V 2 , C ″ V 2 ) and saturated thermal ( ρ S , T S ) properties together with vapor-pressure ( P S , T S ) data were used to calculate other derived thermodynamic properties such as ( K T , Δ H vap , C P , C S , W , ( ∂ P / ∂ T ) ′ V , ( ∂ V / ∂ T ) ′ P , ( d 2 P S / d T 2 ) , and ( d 2 μ / d T 2 ) of isobutanol at saturation near the critical point.
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Experimental Study of the Critical Behavior of the Isochoric Heat Capacity of Aqueous Ammonia Mixture
International Journal of Thermophysics, 2009Co-Authors: N. G. Polikhronidi, Rabiyat G. Batyrova, Ilmutdin M. Abdulagatov, G. V. StepanovAbstract:The Isochoric Heat Capacity of a NH_3 + H_2O (0.2607 mole fraction of ammonia) mixture has been measured in the near- and supercritical regions. Measurements were made in the single- and two-phase regions including the coexistence curve using a high-temperature, high-pressure, nearly constant-volume adiabatic calorimeter. Measurements were made along 38 liquid and vapor isochores in the range from 120.03 kg · m^−3 to 671.23 kg · m^−3 and at temperatures from 478 K to 634 K and at pressures up to 28 MPa. Temperatures at the liquid–gas phase transition curve, T _S( ρ ), for each measured density (isochore) and the critical parameters ( T _C and ρ _C) for the 0.2607 NH_3 + 0.7393 H_2O mixture were obtained using the quasi-static thermograms technique. The expanded uncertainty of the Heat-Capacity measurements at the 95 % confidence level with a coverage factor of k = 2 is estimated to be 2 % to 3 % in the near-critical and supercritical regions, 1.0 % to 1.5 % in the liquid phase, and 3 % to 4 % in the vapor phase. Uncertainties of the density, temperature, and concentration measurements are estimated to be 0.06 %, 15mK, and 5×10^−5 mole fraction, respectively. An unusual behavior of the Isochoric Heat Capacity of the mixture was found near the maxcondetherm point (in the retrograde region). The value of the Krichevskii parameter was calculated using the critical properties data for the mixture and vapor-pressure data for the pure solvent (H_2O). The derived value of the Krichevskii parameter was used to analyze the critical behavior of the strong ( C _ P , K _ T ) and weakly ( C _ V ) singular properties in terms of the principle of isomorphism of critical phenomena in binary mixtures. The values of the characteristic parameters ( K _1, K _2), temperatures ( τ _1, τ _2), and the characteristic density differences (Δ ρ _1, Δ ρ _2) were calculated for the NH_3 + H_2O mixture by using the critical-curve data.
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Isochoric Heat Capacity measurements for pure methanol in the near critical and supercritical regions
International Journal of Thermophysics, 2007Co-Authors: N. G. Polikhronidi, G. V. Stepanov, Ilmutdin M. Abdulagatov, Rabiyat G. BatyrovaAbstract:Isochoric Heat-Capacity measurements for pure methanol are presented as a function of temperature at fixed densities between 136 and 750 kg·m−3. The measurements cover a range of temperatures from 300 to 556 K. The coverage includes the one- and two-phase regions, the coexistence curve, the near-critical, and the supercritical regions. A high-temperature, high-pressure, adiabatic, and nearly constant-volume calorimeter was used for the measurements. Uncertainties of the Heat-Capacity measurements are estimated to be 2–3% depending on the experimental density and temperature. Temperatures at saturation, T S(ρ), for each measured density (isochore) were measured using a quasi-static thermogram technique. The uncertainty of the phase-transition temperature measurements is 0.02 K. The critical temperature and the critical density for pure methanol were extracted from the saturated data (T S,ρS) near the critical point. For one near-critical isochore (398.92 kg·m−3), the measurements were performed in both cooling and Heating regimes to estimate the effect of thermal decomposition (chemical reaction) on the Heat Capacity and phase-transition properties of methanol. The measured values of C V and saturated densities (T S,ρS) for methanol were compared with values calculated from various multiparametric equations of state (EOS) (IUPAC, Bender-type, polynomial-type, and nonanalytical-type), scaling-type (crossover) EOS, and various correlations. The measured C V data have been analyzed and interpreted in terms of extended scaling equations for the selected thermodynamic paths (critical isochore and coexistence curve) to accurately calculate the values of the asymptotical critical amplitudes ( $$A_0^\pm$$ and B 0).
