NOV 15 Colloquia

Granular matter such as sand can sustain stresses like a solid, or flow like a fluid. I will describe experimental investigations of particle dynamics and shear forces in granular flows. Flow transients and multi-component flows are complex and often defy description as solid-like or fluid-like. I will describe two examples of such unique granular properties: We investigate memory effects at the start of a shear flow based on the granular nature of the flow using high speed imaging and confocal microscopy. In the second study, we use mixtures of three or more particle sizes flowing in a tumbler to analyze models for tumbler segregation.