2-dimensional conductivity problem and quasiconformal mappings by Markku Miettinen and Kari Astala, University of Jyvaskyla, Finland JTB 120, 3:30pm Monday, April 20, 1998 Abstract We shall discuss a problem of finding the optimal bounds on the conductivity of mixtures of nonisotropic crystals in terms of their volume ratios only. Our study is based on a breakthrough found by V. Nesi who obtained optimal bounds by applying the optimal quasiconformal estimates established ealier by K. Astala. Quasiconformal estimates turned out to be a crucial tool in this connection, as optimal conductivity problems can be modelled by elliptic variational integrals. Requests for preprints and reprints to: milton@math.utah.edu This source can be found at http://www.math.utah.edu/applied-math/