Discussion: “Normal Stresses at High Shear Rates in a Polymer Solution” (Bernd, L. H., 1968, ASME J. Lubr. Technol., 90, pp. 561–569)

1968 ◽  
Vol 90 (3) ◽  
pp. 569-569
Author(s):  
D. B. Cox
Keyword(s):  
Polymer Solution ◽  
High Shear ◽  
Normal Stresses ◽  
Shear Rates ◽  
High Shear Rates

Mobility Control With Polymer Solutions

1967 ◽  
Vol 7 (02) ◽  
pp. 161-173 ◽  
Author(s):  
W.B. Gogarty
Keyword(s):  
Polymer Solution ◽  
Polymer Solutions ◽  
Control Mechanism ◽  
The United States ◽  
Mobility Control ◽  
High Shear ◽  
Polymer Flow ◽  
Shear Rates ◽  
High Shear Rates ◽  
Secondary Recovery

Abstract With the use of polymer solutions in secondary recovery operations, the need has developed to understand the mobility control mechanism. This study investigated mobility control by considering both permeability and rheological effects. Experiments used a high molecular weight, partially hydrolyzed polyacrylamide polymer. Flow studies took place in reservoir and Berea cores having zero oil saturation. Effective size of the polymer flow unit was inferred from Nuclepore filter tests. Clay studies indicated the particle size capable of decreasing the core permeability. Flushed permeabilities measured the approximate core permeabilities with flowing polymer solutions. These permeabilities were considerably lower than original values. With mobility data and the flushed permeability, maximum effective viscosities were determined for polymer solution flow in a core. Effective viscosities showed that rheological properties play an important part in mobility control with polymer solutions. The study showed that permeabilities decrease and stabilize with polymer flow. At the lower permeabilities, high shear rates exist in the cores. Because of the pseudoplastic character of the polymer solution, the high shear rates caused low effective viscosities. This condition pointed to the inefficient use of the potentially high viscosity of the polymer solution at low shear rates. Introduction In the oil industry, a great deal of interest is being shown in the use of polymer solutions for secondary recovery and a number of polymer floods are being performed in the United States. Some of these floods have become commercial while others have been reported as failures. A number of floods are still in progress and remain to be evaluated. With the advent of polymer flooding, the need developed to understand the mobility control mechanism in porous media.

scholarly journals Structure Evolution of a Polymer Solution at High Shear Rates

1996 ◽  
Vol 29 (5) ◽  
pp. 1422-1432 ◽  
Author(s):  
Kalman Migler ◽  
Chu-heng Liu ◽  
D. J. Pine
Keyword(s):  
Polymer Solution ◽  
Structure Evolution ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates

Normal Stresses at High Shear Rates in a Polymer Solution

1968 ◽  
Vol 90 (3) ◽  
pp. 561-569 ◽  
Author(s):  
L. H. Bernd
Keyword(s):  
Shear Rate ◽  
High Speed ◽  
Width Ratio ◽  
High Shear ◽  
Normal Stresses ◽  
Shear Rates ◽  
Elastic Stresses ◽  
High Shear Rates ◽  
Machine Elements ◽  
High Speed Machine

Based on an examination of the characteristics of shear viscosity versus shear rate, it was postulated that high tensile and compressive stresses might exist in certain liquids at very high shear rates. If obtainable, these stresses could be important as load-bearing mechanisms in high-speed machine elements, and as a sealing mechanism in radial face seals. Such stresses should be evident in a polymer fortified oil, or in a liquid comprised of molecules possessing an appreciable length to width ratio. Therefore, a jet reaction viscometer reaching 107 sec−1 shear rate was developed to explore this possibility. Tests with polyisobutylene dissolved in a kerosene showed that elastic stresses were dominant with respect to viscous stresses at high shear rates. Tensile stresses up to more thn 1000 psi were obtained. However, the life of the polyisobutylene molecule was short. Hence it is concluded that normal stresses of appreciable magnitude can exist in high-speed machine elements under favorable conditions to affect their operation.

Relative Involvement of GPIb/IX-vWF Axis and GPIIb/IIIa in Thrombus Growth at High Shear Rates in the Guinea Pig

1997 ◽  
Vol 17 (5) ◽  
pp. 919-924 ◽  
Author(s):  
Patrick André ◽  
Patricia Hainaud ◽  
Claire Bal dit Sollier ◽  
Leonard I. Garfinkel ◽  
Jacques P. Caen ◽  
...  
Keyword(s):  
Guinea Pig ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates

scholarly journals Microfluidic rheology: A new approach to measure viscosity of ceramic suspensions at extremely high shear rates

Open Ceramics ◽  
2021 ◽  
Vol 5 ◽  
pp. 100052
Author(s):  
V. Carnicer ◽  
C. Alcázar ◽  
M.J. Orts ◽  
E. Sánchez ◽  
R. Moreno
Keyword(s):  
High Shear ◽  
New Approach ◽  
Shear Rates ◽  
High Shear Rates ◽  
Ceramic Suspensions

Flow curves of mixtures of acrylonitrile–styrene copolymers with different molecular weights at extremely high shear rates (abstract)

1991 ◽  
Vol 35 (4) ◽  
pp. 706-706
Author(s):  
Hideroh Takahashi ◽  
Yoshinori Inoue ◽  
Satoru Yamamoto ◽  
Osami Kamigaito
Keyword(s):  
High Shear ◽  
Flow Curves ◽  
Shear Rates ◽  
Molecular Weights ◽  
Styrene Copolymers ◽  
High Shear Rates

Comparison of antithrombotic efficacy between edoxaban, a direct factor Xa inhibitor, and fondaparinux, an indirect factor Xa inhibitor under low and high shear rates

2011 ◽  
Vol 106 (12) ◽  
pp. 1062-1068 ◽  
Author(s):  
Naoki Tsuji ◽  
Yuko Honda ◽  
Chikako Kamisato ◽  
Yoshiyuki Morishima ◽  
Toshiro Shibano ◽  
...  
Keyword(s):  
Shear Rate ◽  
Arterial Thrombosis ◽  
Factor Xa ◽  
High Shear ◽  
Shear Rates ◽  
Thrombosis Model ◽  
Perfusion Chamber ◽  
High Shear Rates ◽  
Antithrombotic Effects ◽  
Antithrombotic Efficacy

SummaryEdoxaban is an oral, direct factor Xa (FXa) inhibitor under late-phase clinical development. This study compared the antithrombotic efficacy of edoxaban with that of an indirect FXa inhibitor, fondaparinux, in in vivo venous and arterial thrombosis models and in ex vivo perfusion chamber thrombosis model under low and high shear rates in rats. Venous and arterial thrombi were induced by platinum wire insertion into the inferior vena cava and by application of FeCl3 to the carotid artery, respectively. The perfusion chamber thrombus was formed by blood perfusion into a collagen-coated capillary at 150 s-1 (low shear rate) and 1,600 s-1 (high shear rate). Effective doses of edoxaban that reduced thrombus formation by 50% (ED50) in venous and arterial thrombosis models were 0.076 and 0.093 mg/kg/h, respectively. In contrast, ED50 of fondaparinux in the arterial thrombosis model (>10 mg/kg/h) was markedly higher compared to ED50 in the venous thrombosis model (0.021 mg/kg/h). In the perfusion chamber thrombosis model, the ratio of ED50 under high shear rate (1.13 mg/kg/h) to that under low shear rate (0.63 mg/kg/h) for edoxaban was 1.9, whereas that for fondaparinux was more than 66. While the efficacy of fondaparinux markedly decreased in arterial thrombosis and in a high-shear state, edoxaban exerted consistent antithrombotic effects regardless of flow conditions. These results suggest that shear rate is a key factor in different antithrombotic effects between edoxaban and fondaparinux.

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