Synopsis The stress vs strain curves in dense colloidal dispersions under start up shear flow are investigated combining experiments on model core shell microgels, computer simulations of hard disk mixtures, and mode coupling theory. In dense fluid and glassy states, the transient stresses exhibit first a linear increase with the accumulated strain, then a maximum (stress overshoot) for strain ...

Numerous studies demonstrate that atherosclerotic lesion development occurs at the site of the blood vessel that is subjected to disturbed flow [1-3], such as the lesser curve of the aortic arch or at bifurcations. These observations have led researchers to hypothesize that different types of blood flow have different effects on the function of endothelial cells (ECs) that line the blood vessel...

AIMS Studies in animals and patients indicate that rapamycin affects vasodilatation differently in outer and inner curvatures of blood vessels. We evaluated in this study whether rapamycin affects endothelial nitric oxide synthase (eNOS) responsiveness to shear stress under normo- and hypercholesteraemic conditions to explain these findings. METHODS AND RESULTS Shear stress levels were varied...

The response of simulated telechelic polymers to shear is investigated. End groups of short polymeric chains form temporary junctions that are continuously broken and formed over time. As in experiments, two shear bands coexist for some shear rates. This allows us to study the microscopic differences between these shear bands. We find that the lifetime of a junction is lower in the high shear r...

– We report the observation of dynamical behaviour in dilute, aqueous solutions of a surfactant CTAT (cetyl trimethylammonium p-toluenesulphonate), below the overlap concentration c⋆. At these concentrations, CTAT forms cylindrical micelles and shows a pronounced shear thickening transition above a concentration-dependent critical shear rate γ̇c. An analysis of the time-series of the stress rela...

A dense mixture of granules and liquid often shows a severe shear thickening and is called a dilatant fluid. We construct a fluid dynamics model for the dilatant fluid by introducing a phenomenological state variable for a local state of dispersed particles. With simple assumptions for an equation of the state variable, we demonstrate that the model can describe basic features of the dilatant f...

Amorphous materials such as metallic, polymeric, and colloidal glasses exhibit complex preparation-dependent mechanical response to applied shear. In particular, glassy solids yield, with a mechanical response that transitions from elastic to plastic, with increasing shear strain. We perform numerical simulations to investigate the mechanical response of binary Lennard-Jones glasses undergoing ...

The stress-strain relations and the yield behavior of a model glass (a 80:20 binary Lennard-Jones mixture) is studied by means of molecular dynamics simulations. In a previous paper it was shown that, at temperatures below the glass transition temperature, Tg, the model exhibits shear banding under imposed shear. It was also suggested that this behavior is closely related to the existence of a ...

We investigate spatio-temporal structures in sheared polymer systems by solving a time-dependent Ginzburg-Landau model in two dimensions. (i) In polymer solutions above the coexistence curve, crossover from linear to nonlinear regimes occurs with increasing the shear rate. In the nonlinear regime the solution behaves chaotically with large-amplitude composition fluctuations. A characteristic he...

[1] Plastic sea ice rheologies that employ teardrop and parabolic lens yield curves and allow varying biaxial tensile stresses have been developed. These rheologies, together with the previously developed ellipse and Mohr-Coulomb-ellipse rheologies, are implemented in a thickness and enthalpy distribution sea ice model to examine the rheological effect in numerical investigations of arctic clim...