Unstable fluctuations develop in the initially quiescent plasma in the improved confinement mode of the H-1 heliac when the radial electric field (Er) shear exceeds some critical value. These unstable Er shear-driven modes are shown to generate zonal-flow-like poloidally symmetric potential structures, similar to those generated in the low confinement mode (Shats M G and Solomon W M 2002 Phys. ...

in the present research mixed convection flow through a copper-water nanofluid in a driven cavity in the presence of magnetic field is investigated numerically. the cavity is heated from top and cooled from bottom while its two vertical walls are insulated. the governing equations including continuity, n-s and energy equations are solved over a staggered grid system. the study is conducted for ...

We perform extensive molecular dynamics simulations of two-dimensional frictionless granular materials to determine whether these systems can be characterized by a single static yield shear stress. We consider boundary-driven planar shear at constant volume and either constant shear force or constant shear velocity. Under steady flow conditions, these two ensembles give similar results for the ...

Rheology of Microfibrillated Cellulose (MFC) suspensions is useful for designing equipment to transport, mix, or process them. Pressure-driven flow behavior is particularly important for MFC suspensions if they are to be pumped, extruded or coated. Herein, we report use of slot and pipe geometries for determination of MFC suspension rheology and compare the results to boundary-driven flows. MFC...

Hybridization on microarray slides is a very slow process. The transport of target molecules towards the immobilized probe spots occurs solely by molecular diffusion and as a result, microarray analyses require overnight incubation and are highly inefficient in terms of capture rate and detection limit. To overcome this diffusion limitation, several solutions have already been reported: electro...

In these lectures, we explore two examples of systems driven far from equilibrium by the application of shear. With these two examples, we investigate different experimental strategies which are designed to directly probe the connection between macroscopic non-linear rheology and the microscopic structure and dynamics of a broad range of soft materials. The study of these systems illustrate the...

We examine the linear stability of fluid interfaces subjected to a shear flow. Our main object is to generalize previous work to an arbitrary Atwood number, and to allow for surface tension and weak compressibility. The motivation derives from instances in astrophysical systems where mixing across material interfaces driven by shear flows may significantly affect the dynamical evolution of thes...

We investigate spinodal decomposition kinetics of an initially nematic dispersion of rodlike viruses. Quench experiments are performed from a flow-stabilized homogeneous nematic state at a high shear rate into the two-phase isotropic-nematic coexistence region at a zero shear rate. We present experimental evidence that spinodal decomposition is driven by orientational diffusion, in accordance w...

We study the instantaneous and local energy injection in a turbulent shear flow driven by volume forces. The energy injection can be both positive and negative. Extremal events are related to coherent streaks. The probability distribution is asymmetric, deviates slightly from a Gaussian shape and depends on the position in shear direction. The probabilities for positive and negative injection a...