Kinetic theory based particle velocity measurements in a symmetric two-story riser show that in the core the flow is laminar and that the granular temperature is approximately given by the analogue of thermal temperature rise in Poiseuille flow. However, like in the turbulent flow in a pipe, the normal kinetic stresses are anisotropic. The shear and the normal stresses are an order of magnitude...

Muscle measurements of Ensis directus, the Atlantic razor clam, indicate that the organism only has sufficient strength to burrow a few centimeters into the soil, yet razor clams burrow to over 70 cm. In this paper, we show that the animal uses the motions of its valves to locally fluidize the surrounding soil and reduce burrowing drag. Substrate deformations were measured using particle image ...

Every adherent eukaryotic cell exerts appreciable traction forces upon its substrate. Moreover, every resident cell within the heart, great vessels, bladder, gut or lung routinely experiences large periodic stretches. As an acute response to such stretches the cytoskeleton can stiffen, increase traction forces and reinforce, as reported by some, or can soften and fluidize, as reported more rece...

Motivated by the direct numerical simulation of particulate flow (i.e., of the motion of fluid-particle mixtures) the authors of this paper, with the assistance of several collaborators, have introduced some years ago a computational methodology based on a fictitious domain formulation involving distributed Lagrange multipliers defined over the particles; this approach allows the flow computati...

The fluidization in the furnace of circulating fluidized bed (CFB) boilers is described. Data have been obtained from a 12 MWth CFB boiler and literature. bottom bubbling rather than fast or turbulently as often assumed. There an extended splash zone above this bed, which particles are thrown up by bubbles fall back onto bed. Other carried further into transport zone, initially saturated gas fl...