Comparison of the values of the interaction parameter ξ from upper critical solution temperatures of acetone + alkanes with values obtained from gas-liquid critical temperatures

1977 ◽  
Vol 30 (4) ◽  
pp. 767 ◽  
Author(s):  
LS Toczylkin ◽  
CL Young
Keyword(s):  
Equation Of State ◽  
Interaction Parameter ◽  
Fluid Model ◽  
Van Der Waals ◽  
Critical Temperatures ◽  
Acetone Hexane ◽  
Critical Solution Temperatures

The upper critical solution temperatures, UCST , of acetone + alkane (n- C5H12 to n-C17H36) and acetone + hexane isomers have been measured. These results are used to calculate an interaction parameter ξ by using the van der Waals one-fluid model together with the Guggenheim equation of state. Values of ξ are compared with those obtained from the gas-liquid critical temperatures. The gas-liquid critical temperatures for the n- alkane + acetone systems were taken from the literature whereas those for the hexane isomers + acetone were measured in this work. The values of ξ calculated from gas-liquid critical temperatures are slightly greater than those calculated from the UCST as has been observed previously for other systems.

Phase-Behavior of Carbon-Dioxide and Hydrocarbon Mixtures

1985 ◽  
Vol 38 (12) ◽  
pp. 1739 ◽  
Author(s):  
RJ Sadus ◽  
CL Young
Keyword(s):  
Carbon Dioxide ◽  
Phase Behavior ◽  
Equations Of State ◽  
Fluid Model ◽  
Van Der Waals ◽  
Solubility Data ◽  
Critical Temperatures ◽  
Hydrocarbon Mixtures ◽  
Critical Solution Temperatures

Upper critical solution temperatures, gas-liquid critical temperatures and solubility data of carbon dioxide and hydrocarbon mixtures have been used to obtain a parameter, ξ, characterizing the interaction between pairs of unlike molecules in the mixture. The calculation of ξ values involved the use of the van der Waals one-fluid model together with the Guggenhiem and Redlich-Kwong equations of state. There is a discrepancy of several percent between ξ values calculated from the three sources of data. Trends in the value of ξ are discussed briefly.

Application of the van der Waals equation of state to polymers III. Correlation and prediction of upper critical solution temperatures for polymer solutions

1994 ◽  
Vol 100 ◽  
pp. 63-102 ◽  
Author(s):  
Vassilis I. Harismiadis ◽  
Georgios M. Kontogeorgis ◽  
Ana Saraiva ◽  
Aage Fredenslund ◽  
Dimitrios P. Tassios
Keyword(s):  
Equation Of State ◽  
Polymer Solutions ◽  
Van Der Waals ◽  
Van Der Waals Equation ◽  
Critical Solution Temperatures

Upper critical solution temperatures of hydrocarbon + fluorocarbon mixtures

1978 ◽  
Vol 31 (1) ◽  
pp. 19 ◽  
Author(s):  
CP Hicks ◽  
RL Hurle ◽  
LS Toczylkin ◽  
CL Young
Keyword(s):  
Reasonable Agreement ◽  
Fluid Model ◽  
Virial Coefficients ◽  
Temperature Data ◽  
Solution Temperature ◽  
Critical Temperatures ◽  
Critical Solution Temperature ◽  
Second Virial Coefficients ◽  
Upper Critical Solution Temperature ◽  
Critical Solution Temperatures

Values of the interaction parameter ξ have been calculated from upper critical solution temperature data by use of the van der Waals one- fluid model for a range of hydrocarbon+fluorocarbon mixtures. The values obtained are compared with values calculated from gas-liquid critical temperatures and mixed second virial coefficients where experimental data on these properties are available. The overall agreement between calculated from these properties is only fair but there is reasonable agreement between ξ calculated from gas-liquid critical temperatures and upper critical solution temperatures for mixtures of quasi-spherical molecules. ��� Experimental upper critical solution temperatures are reported for 26 systems which have not been studied previously. Gas-liquid critical temperatures of four systems are reported.

Application of the van der Waals equation of state to polymers IV. Correlation and prediction of lower critical solution temperatures for polymer solutions

1996 ◽  
Vol 115 (1-2) ◽  
pp. 73-93 ◽  
Author(s):  
Ana Saraiva ◽  
Georgios M. Kontogeorgis ◽  
Vassilis J. Harismiadis ◽  
Aage Fredenslund ◽  
Dimitrios P. Tassios
Keyword(s):  
Equation Of State ◽  
Polymer Solutions ◽  
Van Der Waals ◽  
Van Der Waals Equation ◽  
Critical Solution Temperatures

Gas-liquid critical temperatures of mixtures containing an organosilicon compound

1978 ◽  
Vol 31 (5) ◽  
pp. 957 ◽  
Author(s):  
SD Waterson ◽  
CL Young
Keyword(s):  
Critical Temperature ◽  
Equation Of State ◽  
Hard Sphere ◽  
Organosilicon Compound ◽  
Composition Dependence ◽  
Fluid Model ◽  
Iterative Solution ◽  
Critical Temperatures ◽  
Temperature And Pressure ◽  
The One

The gas-liquid critical temperatures of 16 binary mixtures containing an organosilicon compound have been measured by the sealed-tube method, together with the gas-liquid critical temperature and pressure of tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane.��� The results for the mixtures have been used to calculate a parameter characterizing the interactions between unlike molecules. An iterative solution to the criticality condition was used together with the one-fluid model and a 'hard sphere+attractive term' equation of state. ��� The interaction parameters are discussed briefly. The one-fluid model in the form used here, at least, appears to be unsatisfactory for predicting the composition dependence of the gas-liquid critical temperatures within 5 K for mixtures of molecules of widely differing sizes (i.e. size ratios as estimated from molar volumes of greater than 1 : 4).

The gas-liquid critical properties of alkane mixtures: Cycloalkanes + n-Alkanes and Cycloalkanes + Branched Alkanes

1977 ◽  
Vol 30 (10) ◽  
pp. 2103 ◽  
Author(s):  
KN Marsh ◽  
CL Young
Keyword(s):  
Interaction Energy ◽  
Fluid Model ◽  
Van Der Waals ◽  
Energy Parameter ◽  
Critical Properties ◽  
Critical Temperatures ◽  
Branched Alkanes

The gas-liquid critical temperatures, Tcm of cycloalkane + n-alkane and cycloalkane + branched alkane mixtures are reported. The interaction energy parameter, ξ(expressing the deviation from the Berthelot combining rule), has been calculated for each mixture from the values of Tcm using the van der Waals one-fluid model. The values of ξ are within 0.5% of unity.

Upper critical solution temperatures of hydrocarbon + fluorocarbon mixtures : mixtures with specific interactions

1980 ◽  
Vol 33 (3) ◽  
pp. 465 ◽  
Author(s):  
LS Toczylkin ◽  
CL Young
Keyword(s):  
Equation Of State ◽  
Interaction Energy ◽  
Hard Sphere ◽  
Fluid Model ◽  
Energy Parameter ◽  
Specific Interactions ◽  
The One ◽  
Critical Solution Temperatures

The upper critical solution temperatures of a series of compounds with perfluorotributylamine and with perfluorocyclohexene are reported. From these results the interaction energy parameter, ξ, has been calculated by using a hard sphere+attractive term equation of state, together with the one-fluid model. The values of ξ for these mixtures and a few calculated from literature upper critical solution temperatures have been discussed in terms of possible specific interactions between pairs of unlike molecules.

Gas-gas immiscibility in hydrogen mixtures

1984 ◽  
Vol 37 (1) ◽  
pp. 29
Author(s):  
BN Missen ◽  
CL Young
Keyword(s):  
Equation Of State ◽  
Critical Point ◽  
Binary Mixtures ◽  
Interaction Parameter ◽  
Hard Sphere ◽  
Fluid Model ◽  
Critical Locus ◽  
Energy Interaction ◽  
Hydrogen Mixtures ◽  
The One

Measurements are reported of the slope of the critical locus of binary mixtures of a series of hydrocarbons, and two fluorocarbons, with hydrogen near the critical point of the hydrocarbon (or fluorocarbon).These systems exhibit gas-gas immiscibility of the first kind. The results are compared with predictions from the one-fluid model together with 'a hard sphere + attractive term' equation of state proposed by Guggenheim. The results can be predicted from the theory provided the energy interaction parameter, ξ, is allowed to be somewhat less than that calculated from the Hudson and McCoubrey rule. This is discussed in terms of values of ξ from other measurements, and possible deficiencies in the theory.

scholarly journals The I-Love-Q Relations for Superfluid Neutron Stars

Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 111
Author(s):  
Cheung-Hei Yeung ◽  
Lap-Ming Lin ◽  
Nils Andersson ◽  
Greg Comer
Keyword(s):  
Fluid Dynamics ◽  
Equation Of State ◽  
Neutron Stars ◽  
Quadrupole Moment ◽  
Fluid Model ◽  
Normal Component ◽  
Approximate Equation ◽  
Mean Field Model ◽  
Polytropic Model ◽  
Two Fluid

The I-Love-Q relations are approximate equation-of-state independent relations that connect the moment of inertia, the spin-induced quadrupole moment, and the tidal deformability of neutron stars. In this paper, we study the I-Love-Q relations for superfluid neutron stars for a general relativistic two-fluid model: one fluid being the neutron superfluid and the other a conglomerate of all charged components. We study to what extent the two-fluid dynamics might affect the robustness of the I-Love-Q relations by using a simple two-component polytropic model and a relativistic mean field model with entrainment for the equation-of-state. Our results depend crucially on the spin ratio Ωn/Ωp between the angular velocities of the neutron superfluid and the normal component. We find that the I-Love-Q relations can still be satisfied to high accuracy for superfluid neutron stars as long as the two fluids are nearly co-rotating Ωn/Ωp≈1. However, the deviations from the I-Love-Q relations increase as the spin ratio deviates from unity. In particular, the deviation of the Q-Love relation can be as large as O(10%) if Ωn/Ωp differ from unity by a few tens of percent. As Ωn/Ωp≈1 is expected for realistic neutron stars, our results suggest that the two-fluid dynamics should not affect the accuracy of any gravitational waveform models for neutron star binaries that employ the relation to connect the spin-induced quadrupole moment and the tidal deformability.

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