Structural analysis of flexible pavements has been and still is currently performed using a multi-layer elastic theory. However, for thinly surfaced pavements subjected to light to medium volumes of traffic, the importance of non-linear stress-strain behaviour of unbound granular materials (UGM’s) requires the use of more sophisticated numerical models for structural design and analysis of such...

[1] Field studies suggest that bedrock incision by granular flows may be the primary process cutting valleys in steep, unglaciated landscapes. An expression has been proposed for debris flow incision into bedrock which posits that erosion rate depends on stresses due to granular interactions at the snout of debris flows. Here, we explore this idea by conducting laboratory experiments to test th...

Mutant and normal Xenopus laevis embryos (o-nu, i-nu, 2-nu) were examined in the electron microscope after glutaraldehyde and/or osmium-tetroxide fixation. During cleavage both o-nu and wild-type embryos contain multiple small nucleolar bodies, less than 1 ft in diameter, composed mainly of a fibrous material. By the end of cleavage or beginning of gastrulation, granular caps develop on the fib...

AstEx is a microgravity experiment selected to fly on ESA’s 51st Microgravity Research Campaign in November 2009. The experiment will investigate the dynamics of regolith on asteroid surfaces. Despite their very low surface gravities, asteroids exhibit a number of different geological processes involving granular matter. Understanding the mechanical response of this granular material subject to...

A granular instability is studied experimentally and numerically as a packing of dense granular material positioned above a gap of air falls under gravity in a closed Hele-Shaw cell; a granular analog of the RayleighTaylor instability. A characteristic pattern of fingers separated by dilute bubbles emerges along the interface, and, in contrast to the classical, hydrodynamic instability, a trans...

We present a mesoscopic approach to granular crystal dynamics, which comprises a three-dimensional finite-element model and a one-dimensional regularized contact model. The approach investigates the role of vibrational-energy trapping effects in the dynamic behavior of one-dimensional chains of particles in contact (i.e., granular crystals), under small to moderate impact velocities. The only i...

The PebbleBox and the CrumbleBag are examples of a granular interaction paradigm, in which the manipulation of physical grains of arbitrary material becomes the basis for interacting with granular sound synthesis models. The sounds made by the grains as they are manipulated are analysed, and parameters such as grain rate, grain amplitude and grain density are extracted. These parameters are the...

We have studied the gravity driven flow of spherical shaped, millimetric sized granular material coated with aspherical, micron-sized, near frictionless lubricant particles. Experiments were performed on an inclined plane using two different particles for varying concentrations lubricant. The particle volumetric rate exhibits a non-monotonic behavior increasing concentration. It shows increase ...