We suggest that the irregular structure in Saturn’s B ring arises from the formation of shear-free ring-particle assemblies of up to ∼ 100 km in radial extent. The characteristic scale of the irregular structure is set by the competition between tidal forces and the yield stress of these assemblies; the required tensile strength of ∼ 10 dyn cm is consistent with the sticking forces observed in ...

An electro-rheological (ER) fluid showing trembling shear behavior was fabricated with chitosan particles that had benzene, amine and azo-pendent side groups. This modifiedchitosan dispersed suspension showed four regions in a plot of shear stress against shear rate at high electric field. We analyzed this specific behavior with our suggested model. The model was developed with the spring-dampe...

Behavior of a dilute polymer solution in a random three-dimensional flow with an average shear is studied experimentally. Polymer contribution to the shear stress is found to be more than 2 orders of magnitude higher than in a laminar shear flow. The results indicate that the polymer molecules are strongly stretched by the random motion of the fluid.

To achieve uniform thickness of coated films using non-Newtonian fluids, we are often required well-designed geometries of flow channel in a slot die. This is the case especially for fluids with the properties of both shear thinning and yield stress which is non-negligible in a range of low shear rate such as in an intermittent die coating. In the present work, flow in the slot die has been stu...

We study theoretically the onset of shear banding in the three most common time-dependent rheological protocols: step stress, finite strain ramp (a limit of which gives a step strain), and shear startup. By means of a linear stability analysis we provide a fluid-universal criterion for the onset of banding for each protocol, which depends only on the shape of the experimentally measured time-de...

This paper investigates the axial unsteady flow of a generalized Burgers’ fluid with fractional constitutive equation in a circular micro-tube, in presence of a time-dependent pressure gradient and an electric field parallel to flow direction and a magnetic field perpendicular on the flow direction. The mathematical model used in this work is based on a time-nonlocal constitutive equation for s...

An in vitro bioassay system was developed to study endothelium-mediated, shear stress-induced, or flow-dependent generation of endothelium-derived relaxing factor (EDRF). Monolayers of aortic endothelial cells were grown on a rigid and large surface area of microcarrier beads and were packed in a small column perfused with Krebs bicarbonate solution. The perfusate was allowed to superfuse three...

Vascular endothelial cell migration is critical in many physiological processes including wound healing and stent endothelialization. To determine how preexisting cell morphology influences cell migration under fluid shear stress, endothelial cells were preset in an elongated morphology on micropatterned substrates, and unidirectional shear stress was applied either parallel or perpendicular to...

We reanalyze previous experimental measurements of solid volume fraction, mean velocity, and velocity fluctuations in collisional suspensions of plastic cylinders and water flowing over inclined, erodible beds. We show that the particle pressure scales with the granular temperature, as predicted by kinetic theory of granular gases. The assumption that the particle shear stress is also well pred...