Shear viscosity of a molten short fibers composite

1998 ◽  
pp. 108-109
Author(s):  
Fréderic Meslin ◽  
Arnaud Poitou
Keyword(s):  
1979 ◽  
Author(s):  
M Drummond ◽  
G Lowe ◽  
J Belch ◽  
C Forbes ◽  
J Barbenel

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.


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

1988 ◽  
Vol 61 (5) ◽  
pp. 812-827 ◽  
Author(s):  
Ramesh R. Rahalkar ◽  
Henry Tang

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).


Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 203
Author(s):  
Peter Shternin ◽  
Isaac Vidaña

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.


2021 ◽  
Author(s):  
Patrick Wilms ◽  
Jan Wieringa ◽  
Theo Blijdenstein ◽  
Kees van Malssen ◽  
Reinhard Kohlus

AbstractThe rheological characterization of concentrated suspensions is complicated by the heterogeneous nature of their flow. In this contribution, the shear viscosity and wall slip velocity are quantified for highly concentrated suspensions (solid volume fractions of 0.55–0.60, D4,3 ~ 5 µm). The shear viscosity was determined using a high-pressure capillary rheometer equipped with a 3D-printed die that has a grooved surface of the internal flow channel. The wall slip velocity was then calculated from the difference between the apparent shear rates through a rough and smooth die, at identical wall shear stress. The influence of liquid phase rheology on the wall slip velocity was investigated by using different thickeners, resulting in different degrees of shear rate dependency, i.e. the flow indices varied between 0.20 and 1.00. The wall slip velocity scaled with the flow index of the liquid phase at a solid volume fraction of 0.60 and showed increasingly large deviations with decreasing solid volume fraction. It is hypothesized that these deviations are related to shear-induced migration of solids and macromolecules due to the large shear stress and shear rate gradients.


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