for many transport phenomena in mesoscopic systems of solid-state and molecular pjhysics, classical nonlinear dynamics plays a crucial role wich at the scales involved, is adequately analyzed in semiclassical terms. The project is aimed both at the development of general analytical tecniques of semiclassical nature, and at the study of a various specific transpoprt processes. The methodological part focusses on phase -space representations of quantum mechanics, such as coherent stetes and the wigner function, and their propagation in time employing path integral techiques.transport will be considered in periodically forced systems, to model an external ac, laser, driving , of sufficiently high amplitude and /or frequency so that the under