These Proceedings contain invited lectures presented at the third Interna- tional Conference on "Irreversible Processes and Dissipative Structures" in Kiihlungsborn (German Democratic Republic) in March, 1985. These con- ferences, the first of which was held in Rostock in 1977 and the second in Berlin in 1982, are devoted to the study of irreversible processes far from thermal equilibrium and to the phenomena of selforganization. The meet- ing in Kiihlungsborn brought together some 160 mathematicians, physicists, chemists and biologists from 10 countries, who are all interested in the inter- disciplinary field of synergetics. The main topics of the conference were basic concepts of selforganization and evolution, such as entropy, instabilities, nucleation, dissipative struc- tures, chaos and turbulence. The contributions cover methods from ther- modynamics, the theory of dynamic systems, stochastic and statistic theory, the method of Green's functions, the fluctuation-dissipation theorem, etc. Several problems are studied in more detail, e.g., the kinetics of nucleation especially in finite systems, the dynamics of interfaces, reaction-diffusion sys- tems, chemical and biochemical pattern formation and information process- ing. Further, several contributions are devoted to the development of the concepts of chaos and turbulence. The editors hope that the contributions collected in this volume will pro- vide some new information about the field of selforganization, which is in full development now.

This booklet is devoted to the thermodynamic and kinetic description of first-order phase transitions. In general, the matter of the world exists in different phases. Normally phase ctlanges take place in ther modynamic equilibrium, which will be considered here. Typically, the system is rapidly quenched from a one-phase thermal equilibrium state to a nonequilibrium situation. During the so-ca lIed equilibrium phase transformation process the quenched supersaturated system evolves from the nonequilibrium state to an equilibrium one which consists of two coexisting phases. In aseries of books on phase transitions and critical phenomena (DDMB, GREEN, lEBDWITZ, 1972 - 19B3) an immense amount of material to different aspects of ttlis topic is summarized. The other type of phase transitions takes place in systems far from equilibrium. Due to 'the nonequi1ibrium boundary conditions and the flu xes from the environment into the system the final state of this so called nonequilibrium phase transition is a stable nonequilibrium si tuation. Such interesting processes (e. g. pattern formation, multista bi1ity) do not appear only in physics but also in chemistry, meteorolo gy, biology and many areas of engineering. Concerning questions in this context we recommend the reader to the monographs by HAKEN (197B), and EBElING, FEISTEl (1982). An overview of the problems of recent interest in this field is given in the Proceedings of the Third International Conference on Irreversible Processes and Dissipative Structures, edited by EBElING and Ul8RICHT (1986)."