Does shear viscosity relaxation control the dynamics of critical fluctuations in polystyrene–cyclohexane?

2014 ◽  
Vol 140 (4) ◽  
pp. 044508 ◽  
Author(s):  
Sirojiddin Z. Mirzaev ◽  
Udo Kaatze
Keyword(s):  
Shear Viscosity ◽  
Critical Fluctuations ◽  
Relaxation Control

On the transport properties of a Van der Waals gas near the critical point

1968 ◽  
Vol 46 (24) ◽  
pp. 2821-2841 ◽  
Author(s):  
Luis de Sobrino
Keyword(s):  
Thermal Conductivity ◽  
Time Dependence ◽  
Critical Point ◽  
Bulk Viscosity ◽  
Shear Viscosity ◽  
Van Der Waals ◽  
Transport Coefficients ◽  
Hydrodynamic Equations ◽  
Van Der Waals Gas ◽  
Critical Fluctuations

A calculation of the critical anomalies of the transport coefficients of a simple fluid based on a microscopic model of a nonequilibrium Van der Waals gas is presented. It is found that, in the gas region, the anomalous bulk viscosity behaves as (T – Tc)−2. Both the anomalous thermal conductivity and shear viscosity behave as In (T – Tc)−1, but the anomaly in the shear viscosity is much smaller than the anomaly in the thermal conductivity. The results appear to indicate that previous calculations, in which the time dependence of the critical fluctuations is obtained from hydrodynamic equations, are not valid.

An Assessment of Red Cell Deformability Using a Simple Filtration Method

1979 ◽  
Author(s):  
M Drummond ◽  
G Lowe ◽  
J Belch ◽  
C Forbes ◽  
J Barbenel
Keyword(s):  
Cell Count ◽  
Shear Viscosity ◽  
White Cell Count ◽  
White Cell ◽  
Red Cell ◽  
Cell Deformability ◽  
Red Cell Deformability ◽  
Simple Method ◽  
Filtration Method ◽  
Significant Difference

We investigated the reproducibility and validity of a simple method of measuring red cell deformability (filtration of whole blood through 5 µ sieves) and its relationship to haematocrit, blood viscosity, fibrinogen, white cell count, sex and smoking. The mean coefficient of variation in normals was 3. 7%. Tanned red cells showed marked loss of deformability. Blood filtration rate correlated with haematocrit (r = 0. 99 on dilution of samples, r = 0. 7 in 120 normals and patients). After correction for haematocrit, deformability correlated with high shear viscosity, but not low shear viscosity, fibrinogen or white cell count. In 60 normals there was no significant difference between males and females, or smokers and non-smokers, but in 11 smokers there was an acute fall in deformability after smoking 3 cigarettes (p<0. 05). Reduced deformability was found in acute myocardial infarction (n = 15, p<0. 01) and chronic peripheral arterial disease (n = 15, p<0. 01). The technique is reproducible, detects rigid cells and appears useful in the study of vascular disease.

Macroscopic and molecular shear viscosity

1997 ◽  
Vol 167 (7) ◽  
pp. 721-733 ◽  
Author(s):  
Immanuil L. Fabelinskii
Keyword(s):  
Shear Viscosity

Prediction of Zero-Shear Viscosity of Linear Polybutadienes from the Crossover Point Using Doi-Edwards Theory

1988 ◽  
Vol 61 (5) ◽  
pp. 812-827 ◽  
Author(s):  
Ramesh R. Rahalkar ◽  
Henry Tang
Keyword(s):  
Shear Viscosity ◽  
Amorphous Polymers ◽  
Simple Expression ◽  
Crossover Frequency ◽  
Crossover Point ◽  
Zero Shear Viscosity ◽  
Plateau Modulus ◽  
Good Agreement

Abstract Based upon the Doi-Edwards theory, a simple expression has been obtained for zero-shear viscosity in terms of the plateau modulus and the crossover frequency. There are no adjustable parameters in the expression. The model is in very good agreement with the zero-shear viscosity values for linear polybutadienes, the typical discrepancy being ∼5–10%. If the model can be validated for other linear amorphous polymers, it may become possible to estimate the zero-shear viscosity by measuring a single Theological parameter (the crossover frequency).

scholarly journals Transport Coefficients of Hyperonic Neutron Star Cores

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 203
Author(s):  
Peter Shternin ◽  
Isaac Vidaña
Keyword(s):  
Thermal Conductivity ◽  
Neutron Star ◽  
Shear Viscosity ◽  
Transport Coefficients ◽  
Dense Matter ◽  
Baryon Number ◽  
Nucleon Nucleon ◽  
Total Thermal Conductivity ◽  
Nucleon Force ◽  
Density Region

We consider transport properties of the hypernuclear matter in neutron star cores. In particular, we calculate the thermal conductivity, the shear viscosity, and the momentum transfer rates for npΣ−Λeμ composition of dense matter in β–equilibrium for baryon number densities in the range 0.1–1 fm−3. The calculations are based on baryon interactions treated within the framework of the non-relativistic Brueckner-Hartree-Fock theory. Bare nucleon-nucleon (NN) interactions are described by the Argonne v18 phenomenological potential supplemented with the Urbana IX three-nucleon force. Nucleon-hyperon (NY) and hyperon-hyperon (YY) interactions are based on the NSC97e and NSC97a models of the Nijmegen group. We find that the baryon contribution to transport coefficients is dominated by the neutron one as in the case of neutron star cores containing only nucleons. In particular, we find that neutrons dominate the total thermal conductivity over the whole range of densities explored and that, due to the onset of Σ− which leads to the deleptonization of the neutron star core, they dominate also the shear viscosity in the high density region, in contrast with the pure nucleonic case where the lepton contribution is always the dominant one.

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