Rheological properties of rainbow trout blood

1987 ◽  
Vol 65 (4) ◽  
pp. 879-883 ◽  
Author(s):  
Garth L. Fletcher ◽  
R. Tyson Haedrich
Keyword(s):  
Rainbow Trout ◽  
Shear Rate ◽  
Salvelinus Alpinus ◽  
Salmo Gairdneri ◽  
Pseudopleuronectes Americanus ◽  
Temperature Dependent ◽  
Shear Dependent Viscosity ◽  
Myoxocephalus Scorpius ◽  
Lower Temperature ◽  
Dependent Viscosity

The effects of shear rate and red cell concentration on the viscosity of rainbow trout (Salmo gairdneri) blood were evaluated at 0 and 15 °C using a cone-plate viscometer. The viscosity of blood was shear dependent at both temperatures, with the highest values occurring at the lower temperature and shear rate. The viscosity of plasma was not shear dependent. Viscosity of blood increased in a linear fashion between hematocrits of 0 and 40%. Viscosity of the rainbow trout blood was similar to that of arctic char (Salvelinus alpinus), but considerably lower and less shear and temperature dependent than the bloods of winter flounder (Pseudopleuronectes americanus) and shorthorn sculpin (Myoxocephalus scorpius). It is hypothesized that low shear and temperature dependent blood viscosity may be a characteristic of active fish.

scholarly journals Coronary flow in a perfused rainbow trout heart

1987 ◽  
Vol 129 (1) ◽  
pp. 107-123 ◽  
Author(s):  
A. P. Farrell
Keyword(s):  
Rainbow Trout ◽  
Coronary Flow ◽  
Coronary Circulation ◽  
Coronary Vessels ◽  
Cardiac Metabolism ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Coronary Vascular Resistance ◽  
Coronary Resistance ◽  
Temperature Dependent

A preparation was developed to perfuse the coronary circulation in working hearts from rainbow trout (Salmo gairdneri Richardson). The preparation was used to examine pressure-flow relationships for the coronary circulation as the heart generated physiological and subphysiological work loads. Coronary vascular resistance increased exponentially as coronary flow rate decreased. Coronary resistance was also influenced by cardiac metabolism and acclimation temperature. When heart rate was increased, extravascular compression increased in coronary resistance. Direct vasoconstriction of the coronary vessels, produced by injections of adrenaline into the coronary circulation, was temperature-dependent.

A numerical study of solidification and viscous dissipation effects on polymer melt flow in plane channels

2013 ◽  
Vol 33 (2) ◽  
pp. 95-110
Author(s):  
Mustafa Tutar ◽  
Ali Karakus
Keyword(s):  
Shear Rate ◽  
Phase Change ◽  
Viscous Dissipation ◽  
Polymer Melt ◽  
Viscous Heating ◽  
Transient Phase ◽  
Melt Flow ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Dependent Viscosity

Abstract The combined effects of solidification and viscous dissipation on the hydrodynamic and thermal behavior of polymer melt flow during the injection process in a straight plane channel of constant cross section are numerically studied by considering the shear-rate and temperature-dependent viscosity and transient-phase change behavior. A numerical finite volume method, in conjunction with a modified form of the Cross constitutive equation to account for shear rate, temperature-dependent viscosity changes and a slightly modified form of the method proposed by Voller and Prakash to account for solidification of the liquid phase, is used and a validation with an analytical solution is presented for viscous heating effects. The hydrodynamic and solidified layers growth under the influence of a transient phase-change process and viscous dissipation, are analyzed for a commercial polymer melt flow, polypropylene (PP) for different parametric conditions namely, inflow velocity, polymer injection (inflow) temperature, the channel wall temperature, and the channel height. The results demonstrate that the proposed numerical formulations, including conjugate effects of viscous heating and transient-solidification on the present thermal transport process, can provide an accurate and realistic representation of polymer melt flow behavior during the injection molding process in plane channels with less simplifying assumptions.

scholarly journals Temperature-Dependent Viscosity Model for Silicone Oil and Its Application in Viscous Dampers

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 331
Author(s):  
Márk Venczel ◽  
Gabriella Bognár ◽  
Árpád Veress
Keyword(s):  
Shear Rate ◽  
Torsional Vibration ◽  
Transient Flow ◽  
Silicone Oil ◽  
Viscosity Model ◽  
Working Fluid ◽  
Oil Viscosity ◽  
Temperature Dependent ◽  
Wide Range ◽  
Dependent Viscosity

Silicone fluids belong to the group of pseudoplastic non-Newtonian fluids with complex rheological characteristics. They are considered in basic and applied researches and in a wide range of industrial applications due to their favorable physical and thermal properties. One of their specific field of applications in the automotive industry is the working fluid of viscous torsional vibration dampers. For numerical studies in the design and development phase of this damping product, it is essential to have thorough rheological knowledge and mathematical description about the silicone oil viscosity. In the present work, adopted rheological measurement results conducted on polydimethylsiloxane manufactured by Wacker Chemie with initial viscosity of 1000 Pas (AK 1 000 000 STAB silicone oil) are processed. As a result of the parameter identification by nonlinear regression, the temperature-dependent parameter curves of the Carreau–Yasuda non-Newtonian viscosity model are generated. By implementing these parameter sets into a Computational Fluid Dynamics (CFD) software, a temperature- and shear-rate-dependent viscosity model of silicone fluid was tested, using transient flow and thermal simulations on elementary tube geometries in the size range of a real viscous torsional vibration damper’s flow channels and filling chambers. The numerical results of the finite volume method provide information about the developed flow processes, with especial care for the resulted flow pattern, shear rate, viscosity and timing.

Studies on Methacryloyl Guar Gum: Surface Morphology, Crystallinity, Biodegradability and Viscosity Behavior of Semi-Dilute Solutions

2011 ◽  
Vol 279 ◽  
pp. 327-332
Author(s):  
Wen Fa Xiao ◽  
Li Tao Dong
Keyword(s):  
Shear Rate ◽  
Surface Morphology ◽  
Guar Gum ◽  
Viscosity Model ◽  
Dilute Solutions ◽  
Shear Dependent Viscosity ◽  
Viscosity Behavior ◽  
The Cross ◽  
Dependent Viscosity

Methacryloyl guar gum was investigated with respect to crystallinity, surface morphology, biodegradability and viscosity of semi-dilute solutions. It was studied that the shear-dependent viscosity behaviour could be well described by the Cross viscosity model, under various methacryloyl guar gum concentrations, salts addition and temperature. The zero-shear-rate viscosity was observed to change with different methacryloyl guar gum concentration and decease with the increase of temperature.

Brain Acetylcholinesterase Inhibition and Hepatic Activation of Acephate and Fenitrothion in Rainbow Trout (Salmo gairdneri)

1980 ◽  
Vol 37 (9) ◽  
pp. 1450-1453 ◽  
Author(s):  
J. F. Klaverkamp ◽  
B. R. Hobden
Keyword(s):  
Rainbow Trout ◽  
Liver Homogenate ◽  
Acetylcholinesterase Inhibition ◽  
Salmo Gairdneri ◽  
Ache Inhibitor ◽  
Temperature Dependent ◽  
Brain Ache ◽  
Two Factors ◽  
Brain Acetylcholinesterase ◽  
Hepatic Biotransformation

Two factors, potency of brain acetylcholinesterase (AChE) inhibition and biotransformation by liver homogenate, were investigated to understand the temperature-dependent toxicity of fenitrothion (FTN) in rainbow trout (Salmo gairdneri) and the 600- to 1000-fold differences in concentration between FTN and another organophosphate (OP) insecticide, acephate (ATE), required to produce death in these trout. Concentrations required to produce 50% inhibition of brain AChE were similar for ATE and FTN, ~125 mmol/L and 80 mmol/L, respectively, whereas fenitrooxon (FTO), the oxidative desulfuration metabolite of FTN, was approximately five orders of magnitude more potent. Incubation with liver homogenate, however, demonstrated that a more potent brain AChE inhibitor was produced from ATE, but not from FTN. It is concluded that hepatic biotransformation of FTN to FTO does not explain previous observations of FTN temperature dependency and differences in concentrations producing lethality.Key words: acephate, acetylcholinesterase, biotransformation, brain, fenitrothion, fenitrooxon, liver

Gustatory Responses to Tetrodotoxin and Saxitoxin in Fish: A Possible Mechanism for Avoiding Marine Toxins

1988 ◽  
Vol 45 (12) ◽  
pp. 2182-2186 ◽  
Author(s):  
Kunio Yamamori ◽  
Moritaka Nakamura ◽  
Takashi Matsui ◽  
Toshiaki j. Hara
Keyword(s):  
Rainbow Trout ◽  
Salvelinus Alpinus ◽  
Threshold Concentration ◽  
Arctic Char ◽  
Response Magnitude ◽  
Salmo Gairdneri ◽  
Phasic Response ◽  
Receptor System ◽  
Cross Adaptation ◽  
Integrated Response

The gustatory responses to tetrodotoxin (TTX) and saxitoxin (STX) recorded from the palatine nerve (VIIth cranial nerve) were studied electrophysiological in rainbow trout (Salmo gairdneri) and Arctic char (Salvelinus alpinus). Both toxins were highly effective gustatory stimuli in both species, in rainbow trout, TTX had a threshold concentration 2 × 10−7 mol/L and at 10−5 mol/L evoked a response four times that of 10−3 mol L-proline/L, the most potent amino acid for this species. The threshold for STX was Sower (10−8 mol/L), but unlike TTX the response magnitude reached a maximum at 10−6 mol/L. The reverse occurred in Arctic char; lower threshold for TTX (10−8 mol/L) than STX (10−7 mol/L) and the response magnitude never exceeded that of 10−3 mol L-proline/L. Cross-adaptation experiments indicated that the receptor(s) for TTX are distinct from those which detect amino acids and bile salts and that TTX and STX do not share the same receptor populations. Furthermore, the integrated response to TTX or STX was a fast-adapting, phasic response and rapidly returned to baseline even with continued stimulation. Perfusion of the gustatory organs with these toxins had little toxic effect. The sensitive, specific gustatory receptor system for the toxins suggests the existence of a mechanism for avoiding poisonous prey organisms that has adaptive advantage to the receiver (predator).

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