David Stroud, Department of Physics, The Ohio State University, Columbus, Ohio 43210

We describe a simple method for modeling the cubic nonlinear response of a polycrystalline sample of quasi-one-dimensional conductor. We also propose a decoupling approximation for estimating this response. The results show that a polycrystal of a uniaxial material may have a nonlinear response which is enormously enhanced by local field effects, relative to the single crystal. A similar calculation shows that conductivity noise in such polycrystals may also be greatly enhanced relative to the single-crystal.