ABSTRACT CTS-9529559 Mixing and Segregation mechanisms of granular materials in rotating containers will be investigated by using kinematic and granular dynamics modeling techniques. Kinematic (or " geometrical") investigation will provide generic rules of behavior in the entire volume of a container. Granular dynamics simulations of slightly deformable particles will lead to predictions based on particle properties and micromechanical flow characteristics. A wavelet methodology will be used to characterize the degree of mixing. Both two-and three-dimensional flow situations will be considered. Overall goals are the identification of the dominant mixing and segregation mechanisms in rotating drums, quantitative characterization of mixing in laboratory and industrial conditions, and optimization of mixing processes. Because the current methods of investigation are largely empirical, the proposed project is expected to provide critical advances in the mathematical modeling and understanding of processes to relevance to chemical plants, pharmaceutics, metallurgy, cement and polymer industries. ***