Planar granular shear flow under external vibration

A minimal model for slow dynamics: Compaction of granular media under vibration or shear

Based on experiments of the compaction of granular materials under periodic shear of a packing of glass beads, a minimal model for the dynamics of the packing density as a function of time is proposed. First, a random “energy landscape” is created by a random walk (RW) in energy. Second, an ensemble of RWs is performed for various temperatures in different temperature-time sequences. We identif...

Three-dimensional shear in granular flow.

The evolution of granular shear flow is investigated as a function of height in a split-bottom Couette cell. Using particle tracking, magnetic-resonance imaging, and large-scale simulations, we find a transition in the nature of the shear as a characteristic height H* is exceeded. Below H* there is a central stationary core; above H* we observe the onset of additional axial shear associated wit...

Granular shear flow in varying gravitational environments

Despite their very low surface gravities, asteroids exhibit a number of different geological processes involving granular matter. Understanding the response of this granular material subject to external forces in microgravity conditions is vital to the design of a successful asteroid sub-surface sampling mechanism, and in the interpretation of the fascinating geology on an asteroid. We have des...

Adhesion under Shear Flow

The 4 integrin, 4 7, plays an important role in recruiting circulating lymphocytes to the gastrointestinal tract, where its ligand mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is preferentially expressed on high endothelial venules (HEVs). Dual antagonists of 4 1 and 4 7, N-(2,6-dichlorobenzoyl)-(L)-4-(2 ,6 -bis-methoxyphenyl)phenylalanine (TR14035) and N-{N-[(3,5-dichlorobenzene)sulfo...

Erythrocyte deformation under shear flow.