This volume of Modem Aspects of Electrochemistry contains sixchapters. The first four chapters are about phenomena of interestat the microscopic level and the last two are on phenomena at themacroscopic level.In the first chapter, Uosaki and Kita review various theoreticalmodels that have been presented to describe the phenomena thatoccur at an electrolyte/semiconductor interface under illumination.In the second chapter, Orazem and Newman discuss the samephenomena from a different point of view. In Chapter 3, Bogus-lavsky presents state-of-the-art considerations of transmembranepotentials and other aspects of active transport in biological systems....