New Absolute Molecular Weight Method—Linear High Polymers

1959 ◽  
Vol 32 (1) ◽  
pp. 97-98
Author(s):  
F. Bueche ◽  
S. W. Harding
Keyword(s):  
Molecular Weight ◽  
Shear Rate ◽  
Shear Viscosity ◽  
Rate Dependence ◽  
Zero Shear Viscosity ◽  
Molecular Weights ◽  
Weight Method ◽  
Shear Rate Dependence ◽  
High Polymers

Abstract It has been shown that the shear-rate dependence of the viscosity of concentrated polymer solutions can be explained in terms of known parameters of the solution. If the concentration, temperature, zero shear viscosity, and molecular weight of the polymer are known, the decrease in viscosity with increasing shear rate can be predicted. Conversely, if one measures the shear-rate dependence of the viscosity, the molecular weight may be computed. We believe this provides a convenient method for the absolute determination of molecular weights of linear, coiling, high polymers.

scholarly journals Shear-Rate Dependence of Steady-Shear Viscosity of Suspensions

1983 ◽  
Vol 11 (1) ◽  
pp. 34-38
Author(s):  
Yoichi MIKAMI ◽  
Toshiro MASUDA ◽  
Shigeharu ONOGI
Keyword(s):  
Shear Rate ◽  
Shear Viscosity ◽  
Rate Dependence ◽  
Steady Shear ◽  
Steady Shear Viscosity ◽  
Shear Rate Dependence

scholarly journals Shear-rate dependence of thermodynamic properties of the Lennard-Jones truncated and shifted fluid by molecular dynamics simulations

2021 ◽  
Author(s):  
Martin P. Lautenschlaeger ◽  
Hans Hasse
Keyword(s):  
Molecular Dynamics ◽  
Shear Stress ◽  
Shear Rate ◽  
Molecular Dynamics Simulations ◽  
Local Structure ◽  
Rate Dependence ◽  
Lennard Jones ◽  
Fluid Properties ◽  
Dynamics Simulations ◽  
Shear Rate Dependence

It was shown recently that using the two-gradient method, thermal, caloric, and transport properties of fluids under quasi-equilibrium conditions can be determined simultaneously from nonequilibrium molecular dynamics simulations. It is shown here that the influence of shear stresses on these properties can also be studied using the same method. The studied fluid is described by the Lennard-Jones truncated and shifted potential with the cut-off radius r*c = 2.5σ. For a given temperature T and density ρ, the influence of the shear rate on the following fluid properties is determined: pressure p, internal energy u, enthalpy h, isobaric heat capacity cp, thermal expansion coefficient αp, shear viscosity η, and self-diffusion coefficient D. Data for 27 state points in the range of T ∈ [0.7, 8.0] and ρ ∈ [0.3, 1.0] are reported for five different shear rates (γ ̇ ∈ [0.1,1.0]). Correlations for all properties are provided and compared with literature data. An influence of the shear stress on the fluid properties was found only for states with low temperature and high density. The shear-rate dependence is caused by changes in the local structure of the fluid which were also investigated in the present work. A criterion for identifying the regions in which a given shear stress has an influence on the fluid properties was developed. It is based on information on the local structure of the fluid. For the self-diffusivity, shear-induced anisotropic effects were observed and are discussed.

EFFECTS OF FRESH PLASMA OR WHOLE BLOOD TRANSFUSIONS ON PATIENTS WITH VARIOUS TYPES OF MUCOPOLYSACCHARIDOSIS

PEDIATRICS ◽  
1972 ◽  
Vol 50 (5) ◽  
pp. 688-692
Author(s):  
Anatole S. Dekaban ◽  
Kenton R. Holden ◽  
George Constantopoulos
Keyword(s):  
Molecular Weight ◽  
Weight Distribution ◽  
Whole Blood ◽  
Blood Transfusions ◽  
Molecular Weights ◽  
The Third ◽  
Clinical Observations ◽  
Before And After ◽  
Fresh Plasma

Repeated fresh plasma or whole blood transfusions were given to five patients with either Hurler, Hunter, or Sanfilippo types of mucopolysaccharidosis. Clinical observations and total 24-hour urinary AMPS and their composition and molecular weight distribution were determined before, during, and after transfusions. The two patients who received plasma transfusions showed no noticeable change in the amount of AMPS excreted; of the three patients who received whole blood transfusions, two had slightly less excretion of AMPS while the third showed no difference. The AMPS in the CSF were measured in one patient before and after blood transfusions and found to be unchanged; likewise, the determination of molecular weights in the isolated AMPS was virtually identical. In the patients studied, the transfusions caused no demonstrable difference in the patients' clinical condition.

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