Studies are proposed in two main areas: the physics of flowing sand and the dynamics of heat flow and convection in liquid 3He / superfluid 4He mixtures. Specific studies: Sand:- 1. Using X-ray and other techniques, the propagating waves that we have discovered in simple flow experiments. 2. Continue modeling these flows using cellular automata. 3. The filamentary (and possibly fractal) stress chains which are known to form in two-dimensional arrays of disks and probably occur in 3-d grain arrays as well. Helium:- 1. Continue an experimental and theoretical characterization of the convective states in superfluid mixtures. 2. Use techniques recently developed by the P.I. to probe the transport coefficients and Kapitsa (boundary) resistance for very dilute mixtures of 3He in superfluid 4He. An understanding of granular dynamics would lead to iportant technological improvements and possibly the avoidance of catastrophes. The proposed work on He will enhance our knowledge of quantum-mechanical systems. In addition, it is of some technical importance in that it may help to explain limitations on the transport of matter, including ozone between temperate and polar latitudes.
