Article Abstract:
Experiments to determine avalanche dynamics in a pile of rice indicate that self-organized criticality (SOC) depends on the mechanism of energy dissipation. SOC is a concept associated with avalanches in a pile of sand where the effect is consistent. The relaxation dynamics in long rice grains are characterized by a slow and coherent movement of the grains, with the retention of the solid internal structure. The chances of an avalanche with spherical rice grains that roll down rapidly are low.
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Article Abstract:
V. Frette and colleagues test certain features of self-organized criticality (SOC) by dropping grains of rice. Short, fat grains lead to large avalanches. Larger and longer grains lead to a power-law distribution for avalanche sizes, which is the characteristic of self-organized criticality. Controlled experiments of SOC on a granular media do not provide definite results. Better results are observed in numerical simulations.
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Article Abstract:
Single avalanches were created by perturbing a static layer of glass beads on a rough inclined plane. Two distinct types of avalanche were observed, with a thin layer resulting in a avalanche propagating downhill and laterally, while a thick layer results in an avalanche front also propagating upwards. The perturbation threshold for triggering avalanches decreased to zero at a critical slope.
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