Physical properties (density in kg m-3, viscosity, sinking rates and dispersion rate) of the gametes and associated spawned materials were measured for three species of sea urchin, Tripneustes gratilla, Echinometra mathaei and Colobocentrotus atratus, from habitats that differ in wave exposure. The gametes of all three species are negatively buoyant, highly viscous and exhibit shear-thinning (a...

BACKGROUND/AIMS High viscosity silicone oils are used as tamponade agents to increase the resistance to emulsification; however, this makes the oils more difficult to inject. Increasing the extensional viscosity is one way to reduce emulsification. This study aimed to evaluate how silicone oils with increased extensional viscosity behave in terms of their ease of injection. METHODS The shear ...

The high cardiac output, arterial blood pressure and cardiac energy demand of tuna make it likely that blood viscosity has an important influence on cardiovascular function. Furthermore, tuna regularly subject themselves to ambient temperature changes of 10°C or more during their daily vertical migrations. They can also maintain muscle temperatures several degrees Celsius above ambient and ...

In this study, we characterize the shear and extensional rheology of dilute to semidilute solutions of cellulose in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIAc). In steady shear flow, the semidilute solutions exhibit shear thinning, and the high-frequency complex modulus measured in small amplitude oscillatory shear flow exhibits the characteristic scaling expected for solutions...

in this study, effects of multi walled carbon nanotubes and temperature on rheological behavior of engine oil (10w40) have been examined. for this purpose, the experiments were carried out in the temperature range of 5-55°c for several suspensions with solid volume fractions of 0.025%, 0.05%, 0.1%, 0.25%, 0.5% and 0.75%. the viscosity of all samples was measured in the shear rate range of 666s-...

rheological characteristics of al2o3, cuo and tio2 nano particles were investigated in oil asthe base fluid at 1 and 2 wt.%. constitutive relations for non-newtonian fluid were discussedbased on the power-law model. measured viscosities of each nanofluid were used to evaluatethe power-law and consistency index. results indicated that the nanofluid viscosity decreasedby increasing the concentrat...

In many lubrication processes, lubricating oils containing polymer additives are subject to high shear rate through very small clearance channels. While the influence of shear rate on the performance of these lubricants has been well examined, very little is known about the effects of channel size. In this study a specially designed microchannel viscometer has been used to experimentally charac...

Foam and emulsion stability has long been believed to correlate with the surface shear viscosity of the surfactant used to stabilize them. Many subtleties arise in interpreting surface shear viscosity measurements, however, and correlations do not necessarily indicate causation. Using a sensitive technique designed to excite purely surface shear deformations, we make the most sensitive and prec...

An EMD model for nanocolloidal dispersions considering the interaction between atoms within solid particles is developed for viscosity calculation and studying the effect of the particle size and volume fraction. Strong oscillations are observed in the pressure tensor autocorrelation function. Elimination of this oscillation is achieved by adjusting the potential among atoms of nanoparticles to...

The apparent shear viscosity of p-methoxybenzylidene-p'-n-butylaniline in the presence of electrohydrodynamic convection (EHC) is investigated experimentally. In the absence of an electric field, directors are almost aligned along the flow direction such that the viscosity is close to the minimum of the Miesowicz viscosities. Since EHC disturbs the flow-aligned director configuration, the visco...