This book contains the proceedings of a workshop held at the Institute Laue-Langevin in Grenoble in September 1988. Review articles and contributed papers survey recent theoretical and experimental developments on disordered materials and in particular on glasses. A large part of the book concerns the recently proposed mode-coupling approach to the behaviour of a viscous liquid around its glass transition, where the relevant dynamics extend over a broad range in time scales and the application of quite different experimental techniques becomes essential. Contributions report on experiments using dielectric relaxation, NMR or light scattering techniques, and especially neutron scattering techniques. One signature of disordered materials is the occurrence of an excess vibrational density of states at low frequencies. Some situations are presented where the density of states can be understood by taking into account the peculiarities of intra- and intermolecular motions. Another approach to the dynamics of disordered materials is the fracton picture, developed to describe the excitations of fractal objects. Several contributions discuss the dynamics of such fractals, studying mainly the vibrational density of states, and some discuss the application of the fracton concept to materials without a fractal structure like glasses.

Halogenated derivatives of simple hydrocarbons, like chloro-and fluoromethanes and -ethanes, are important chemicals in many industries for example as working media in organi Rankine cycles and refrigerating pro cesses. Although there are ecological reasons against using these substances, it is expected that they cannot be substituted in all cases. But optimizing the processes in which these substances have to be used can also contribute to minimizing the possible damage. This book summarizes the extensive experimental material available on the thermodynamic properties of 16 pure and mixed halogenated hydrocarbons, so that it can easily be used both by process and design engineers. The project was initiated by the late Professor Dr.-Ing. Eberhard Bender and Prof. Dr.-Ing. Dr.-Ing. E.h. H.D. Baehr. We would like to express our gratitude especially to Prof. Baehr for his continuing interest and to Springer-Verlag for their patience. Besides the authors, quite a large number of students contributed to the completion of the book. Among them we are most obliged to Mr. L. Hoffmann and Mr. F. Strepp for their assistance in preparing tables, diagrams and charts. We hope that this book will prove to be useful to many colleagues, and we welcome proposals, advice, and comments."

A Symposium on Aerothermodynamics of Combustors was held at the Institute of Applied Mechanics of the National Taiwan University from 3 to 5 June 1991 and was attended by 130 delegates from eight countries. The topics of the forty formal presentations included measurements and calculations of isothermal simulations and of combusting flows with one and two phases, and with consideration of configurations ranging from simple diffusion to gas-turbine flows. The discussions inside and outside of the Symposium Hall were lively and an open forum session demonstrated the range of opinions currently and strongly held. The International Union of Theoretical and Applied Mechanics initiated the Symposium under the chairmanship of Professor R S L Lee and with the Scientific Committee listed below. It benefited from sponsorship, again as listed below, and from contributors who presented interesting and up-to-date descriptions of their research. Invited lectures were delivered by Professors R Bilger and F Weinberg and set the scene in terms of quality of material and presentation.

Computer Simulation Studies in Condensed-Matter Physics VIII covers recent developments in this field presented at the 1995 workshop, such as new algorithms, methods of analysis, and conceptual developments. This volume is composed of three parts. The first part contains invited papers that deal with simulational studies of classical systems. The second part is devoted to invited papers on quantum systems, including new results for strongly correlated electron and quantum spin models. The final part comprises contributed presentations.

The subject of laminar-turbulent transition is of considerable practical importance and has a wide range of engineering applications. For this reason, the International Union of Applied Mechanics decided to sponsor a third Symposium on "Laminar-Turbulent Transition," which would be organised by the ONERA Toulouse Research Center and held at "Ecole Nationale Superieure de l'Aeronautique et de l'Espace" in 1989. It was supposed that like the two previous IUTAM Symposia (Stuttgart 1979 and Novosibirsk 1984) the symposium would be devoted to experimental of laminar-turbulent transition In fluids, i.e. the and theoretical studies physical problem of transition and mathematical modelling in shear flows. The contributed papers were selected by the Scientific Committee from extended abstracts. The larger number of highly qualified papers submitted for presentation led us to include in the program poster sessions, which could be held during morning, lunch and afternoon breaks, and to take the decision that the symposium should last five days (from Monday 11 to Friday 15 September). An excursion on Wednesday offering a well deserved rest and the occasion of new personal exchanges between the participants seems to have been appreciated by all. The symposium consisted of 8 invited lectures and 62 contributed pa pers presented either on oral or poster sessions."

This special volume contains several articles written in honour of Professor IngolfTeipel on the occasion of his 65th birthday. Professor Teipel was born on March 15th, 1933 in Wissen/Sieg. He started his school career in Betzdorf/Sieg. From 1943 to 1951 he went to the Gymnasium in Betzdorf, where he obtained his school-leaving exam after only 8 years. In 1951 Professor Teipel started his studies in Mechanical Engineering at the Technical University of Aachen and got his diploma at the Aerodynamic Institute in 1956. Then Professor Teipel decided to join the research group of the Institute of Theoretical Gasdynamics at the Deutsche Versuchsanstalt fiir Luft und Raumfahrt (DVL), the famous institute of Professor Oswatitsch, where he spent about 13 years until 1968. At the Technical University of Aachen he finished his dissertation devoted to spherical-symmetric shock waves and he obtained his doctorate in Mechanical Engineering in 1960. Some years later he went as a guest scientist to the Aerospace Laboratories of Dayton, Ohio, USA. In 1965 Professor Teipel fmished his habilitation work with a paper on unsteady transonic pressure forces at the Technical University of Aachen, where he recieved the venia legendi in fluid mechanics. In this year, Professor Teipel was given the freedom of the state Tennessee, USA."

This text presents an introduction to the application of the finite ele ment method to the analysis of heat transfer problems. The discussion has been limited to diffusion and convection type of heat transfer in solids and fluids. The main motivation of writing this book stems from two facts. Firstly, we have not come across any other text which provides an intro duction to the finite element method (FEM) solely from a heat transfer perspective. Most introductory texts attempt to teach FEM from a struc tural engineering background, which may distract non-structural engineers from pursuing this important subject with full enthusiasm. We feel that our approach provides a better alternative for non-structural engineers. Secondly, for people who are interested in using FEM for heat transfer, we have attempted to cover a wide range of topics, presenting the essential the ory and full implementational details including two FORTRAN programs. In addition to the basic FEM heat transfer concepts and implementation, we have also presented some modem techniques which are being used to enhance the accuracy and speed of the conventional method. In writing the text we have endeavoured to keep it accessible to persons with qualifications of no more than an engineering graduate. As mentioned earlier this book may be used to learn FEM by beginners, this may include undergraduate students and practicing engineers. However, there is enough advanced material to interest more experienced practitioners.

At the present moment, after the success of the renormalization group in providing a conceptual framework for studying second-order phase tran sitions, we have a nearly satisfactory understanding of the statistical me chanics of classical systems with a non-random Hamiltonian. The situation is completely different if we consider the theory of systems with a random Hamiltonian or of chaotic dynamical systems. The two fields are connected; in fact, in the latter the effects of deterministic chaos can be modelled by an appropriate stochastic process. Although many interesting results have been obtained in recent years and much progress has been made, we still lack a satisfactory understanding of the extremely wide variety of phenomena which are present in these fields. The study of disordered or chaotic systems is the new frontier where new ideas and techniques are being developed. More interesting and deep results are expected to come in future years. The properties of random matrices and their products form a basic tool, whose importance cannot be underestimated. They playa role as important as Fourier transforms for differential equations. This book is extremely interesting as far as it presents a unified approach for the main results which have been obtained in the study of random ma trices. It will become a reference book for people working in the subject. The book is written by physicists, uses the language of physics and I am sure that many physicists will read it with great pleasure."

This volume contains the written versions of lectures held at the "23. Internationale Universit tswochen fUr Kernphysik" in Schladming, Austria, in February 1984. Once again the generous support of our sponsors, the Austrian Ministry of Science and Research, the Styrian Government and others, had made it possible to organize this school. The aim of the topics chosen for the meeting was to present different aspects of stochastic methods and techniques. These methods have opened up new ways to attack problems in a broad field ranging from quantum mechanics to quantum field theory. Thanks to the efforts of the lecturers it was possible to take this development into account and show relations to areas where stochastic methods have been used for a long time. Due to limited space only short manuscript versions of the many seminars presented could be included. The lecture notes were reexamined by the authors after the school and are now published in their final form. It is a pleasure to thank all the lecturers for their efforts which made it possible to speed up publication. Thanks are also due to Mrs. Neuhold for her careful typing of the notes. H. Mitter L. Pittner Acta Physica Austriaca, Suppl. XXVI, 3-52 (1984) (c) by Springer-Verlag 1984 STOCHASTIC PROCESSES - QUANTUM PHYSICS+ by L. STREIT Universitat Bielefeld BiBoS D-4800 Bielefeld. FR Germany I.

Non-uniform combustion, as encountered in diesel and gas turbine engines, furnaces, and boilers, is responsible for the conversion of fossil fuel to energy and also for the corresponding formation of pollutants. In spite of great research efforts in the past, the mechanism of non-uniform combustion has remained less explored than that of other combustion types, since it consists of many, mostly transient processes which influence each other. In view of this background, a group research project, "Exploration of Combustion Mechanism," was established to explore the mechanism of combustion, especially that of diffusive combustion, and also to find efficient ways to control the combustion process for better utilization of fuel and the reduction of pollutant emission. The group research was started, after preparatory activity of 2 years, in April 1988, for a period of 3 years, as a project with a Grant-in-Aid for Scientific Research of Priority Area subsidized by the Ministry of Education, Science and Culture of Japan. The entire group of 43 members was set up as an organizing committee of 13 members, and five research groups, consisting of 36 members. The research groups were: (1) Steady combustion, (2) Unsteady spray combustion, (3) Control of combustion, (4) Chemistry of combustion, and (5) Effects of fuels. At the beginning of the project it was agreed that we should pursue the mechanism of combustion from a scientific viewpoint, namely, the target of the project was to obtain the fundamentals, or "know why," rather than "know how" of combustion.

Crystal pulling is an industrial process and provides the bulk of semiconductor crystals for the semiconductor industry. Initially a purely empirical process, the increase in importance and size of the industry has led to basic research into the fundamentals of the process - particularly the modelling of heat and mass transfer. The book has been written by the recognized authority on Czochralski crystal-growth techniques. It is an attempt to strengthen the interface between the practical crystal grower and the applied mathematician involved in analytical and computer modelling. Its focus is on the physics, chemistry and metallurgy of the process. From reviews: "... There is a need for a modern, non-trivial text on Czochralski growth ... and Dr. Hurle is eminently suited to write such a text."; "Dr. Hurle is probably uniquely qualified to write a book on ... (the Czochralski) growth process. ... He has published a great deal of very substantial as well as innovative work in this area."

This volume contains papers presented at the Thirteenth Taniguchi Symposium on the Theory of Condensed Matter, which was held at Kashikojima (in Ise Shima National Park), Japan, from 6th to 9th November, 1990. The topic of the symposium was Molecular Dynamics Simulations. The general objective of this series of the Taniguchi Symposia is to encour age developing fields of great promise in condensed matter physics. Our theme, molecular dynamics (MD) simulations, certainly fulfills this requirement, be cause the field is developing at a remarkable pace and its future is considered almost boundless. It was in the 1950s that the original idea of the MD methods was first pro posed and applied to the study of physical systems composed of many particles. In fact, the invention of the MD techniques occurred soon after the construction of the first computers. For almost 35 years since then, MD methods, together with Monte Carlo methods, have played major parts in the drama of computer simulations. The triumph of MD simulations is not confined to numerical aspects of detailed analyses of physical systems. MD simulations have verified some un expected facts and introduced some new concepts, all of which had never been predicted previously from analytical theories. The occurrence of the Alder tran sition in a system of repulsive particles and the behavior of the long-time tails of the velocity autocorrelation function for a liquid are just two examples of the results achieved by means of MD studies."

The formation and evolution of complex dynamical structures is one of the most exciting areas of nonlinear physics. Such pattern formation problems are common in practically all systems involving a large number of interacting components. Here, the basic problem is to understand how competing physical forces can shape stable geometries and to explain why nature prefers just these. Motivation for the intensive study of pattern formation phenomena during the past few years derives from an increasing appreciation of the remarkable diversity of behaviour encountered in nonlinear systems and of universal features shared by entire classes of nonlinear processes. As physics copes with ever more ambi tious problems in pattern formation, summarizing our present state of knowledge becomes a pressing issue. This volume presents an overview of selected topics in this field of current interest. It deals with theoretical models of pattern formation and with simulations that bridge the gap between theory and experiment. The book is a product of the International Symposium on the Physics of Structure Formation, held from October 27 through November 2, 1986, at the Institute for Information Sciences of the University of Tiibingen. The symposium brought together a group of distinguished scientists from various disciplines to exchange ideas about recent advances in pattern formation in the physical sciences, and also to introduce young scientists to the fi"

The core of the material on large scale dynamics of interacting particles grew out of courses I taught at the Katholieke Universiteit Leuven, Rutgers Universi ty, and the Ludwig-Maximilians-Universitat Munchen and out of lectures I gave at the workshop "Hydrodynamical Behavior of Microscopic Systems" at the Universita dell'Aquila. I had the good luck of being helped through difficult ground by many friends. Amongst them I am deeply indebted to Joel L. Lebowitz. He got me started. Relatively little would have been achieved without his never-ending curiosity and insistence on clarity. Furthermore, I gratefully acknowledge the cooperation of Michael Aizenman, Henk van Beijeren, Carlo Boldrighini, Jean Bricmont, Paola Calderoni, Brian Davies, Anna DeMasi, Roland Dobrushin, Detlef Durr, Gregory Eyink, Mark Fannes, Pablo Ferrari, Alberto Frigerio, Joseph Fritz, Antonio Galves, Shelly Goldstein, Vittorio Gorini, Reinhard Illner, Claude Kipnis, Joachim Krug, Oscar Lanford, Reinhard Lang, Joel Lebowitz, Christian Maes, Stefano Olla, George Papanicolaou, Errico Presutti, Mario Pulvirenti, Fraydoun Rezakhanlou, Hermann Rost, Yasha Sinai, Yuri Suhov, Domo Szasz, Ragu Varadhan, Andre Verbeure, David Wick, and Horng-Tzer Yau. The list is somewhat lengthy, perhaps, but besides thanks I want to make clear that what I will describe is the outcome of a common scientific enterprise. I thank Henk van Beijeren and Detlef Durr for careful reading of and com ments on a previous version. Paola Calderoni and Detlef Durr supplied me with the proof in Part I, Chapter 8. 4 which is most appreciated. Munchen, May 1991 Herbert Spohn Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ."

Owing to efforts and legislative action - initiated above all by the government of the United States - to use cleaner fuels and thus make a contribution towards a better environment, public attention is back again on using methanol in carbu rettor and diesel engines. Most prominent among the raw materials from which methanol can be produced is coal, whose deposits and resources are many times larger than those of liquid and gaseous hydrocarbons. This book deals with the production of methanol from coal. It describes both the individual steps that are required for this process and the essential ancillary units and offsites associated with the process itself . . It is not meant to inform the reader about the intricate details of the processes, which can much better be taken from the specialized literature that deals exclusively and in detail with them or from the well-known standard engineering books. Rather, this book is to give the reader an impression how manifold a field this is, how many process variations and combinations the designer of such plants has to consider in order to arrive at an optimum design in each particular case. Apart from the production of chemical-grade methanol, the book deals briefly also with fuel methanol production, i. e. with the production of alcohol mixes. One of the many possible routes from coal to methanol is illustrated by a process flow diagram, and a material and energy balance is compiled for this typical example."

This book gives the first detailed coherent treatment of a relatively young branch of statistical physics - nonlinear nonequilibrium and fluctuation-dissipative thermo dynamics. This area of research has taken shape fairly recently: its development began in 1959. The earlier theory -linear nonequilibrium thermodynamics - is in principle a simple special case of the new theory. Despite the fact that the title of this book includes the word "nonlinear", it also covers the results of linear nonequilibrium thermodynamics. The presentation of the linear and nonlinear theories is done within a common theoretical framework that is not subject to the linearity condition. The author hopes that the reader will perceive the intrinsic unity of this discipline, and the uniformity and generality of its constituent parts. This theory has a wide variety of applications in various domains of physics and physical chemistry, enabling one to calculate thermal fluctuations in various nonlinear systems. The book is divided into two volumes. Fluctuation-dissipation theorems (or relations) of various types (linear, quadratic and cubic, classical and quantum) are considered in the first volume. Here one encounters the Markov and non-Markov fluctuation-dissipation theorems (FDTs), theorems of the first, second and third kinds. Nonlinear FDTs are less well known than their linear counterparts.

Ordinary thermodynamics provides reliable results when the thermodynamic fields are smooth, in the sense that there are no steep gradients and no rapid changes. In fluids and gases this is the domain of the equations of Navier-Stokes and Fourier. Extended thermodynamics becomes relevant for rapidly varying and strongly inhomogeneous processes. Thus the propagation of high frequency waves, and the shape of shock waves, and the regression of small-scale fluctuation are governed by extended thermodynamics. The field equations of ordinary thermodynamics are parabolic while extended thermodynamics is governed by hyperbolic systems. The main ingredients of extended thermodynamics are * field equations of balance type, * constitutive quantities depending on the present local state and * entropy as a concave function of the state variables. This set of assumptions leads to first order quasi-linear symmetric hyperbolic systems of field equations; it guarantees the well-posedness of initial value problems and finite speeds of propaga tion. Several tenets of irreversible thermodynamics had to be changed in subtle ways to make extended thermodynamics work. Thus, the entropy is allowed to depend on nonequilibrium vari ables, the entropy flux is a general constitutive quantity, and the equations for stress and heat flux contain inertial terms. New insight is therefore provided into the principle of material frame indifference. With these modifications an elegant formal structure can be set up in which, just as in classical thermostatics, all restrictive conditions--derived from the entropy principle-take the form of integrability conditions.

The Boundary Element Method (BEM) has become established as an effective tool for the solutions of problems in engineering science. The salient features of the BEM have been well documented in the open literature and therefore will not be elaborated here. The BEM research has progressed rapidly, especially in the past decade and continues to evolve worldwide. This Symposium was organized to provide an international forum for presentation of current research in BEM for linear and nonlinear problems in solid and fluid mechanics and related areas. To this end, papers on the following topics were included: rotary wing aerodynamics, unsteady aerodynamics, design and optimization, elasticity, elasto dynamics and elastoplasticity, fracture mechanics, acoustics, diffusion and wave motion, thermal analysis, mathematical aspects and boundary/finite element coupled methods. A special session was devoted to parallel/vector supercomputing with emphasis on mas sive parallelism. This Symposium was sponsored by United Technologies Research Center (UTRC), NASA Langley Research Center, and the International Association of Boundary Ele ment Methods (lAB EM) . We thank the UTRC management for their permission to host this Symposium. In particular, we thank Dr. Arthur S. Kesten and Mr. Robert E. Olson for their encouragement and support. We gratefully acknowledge the support of Dr. E. Carson Yates, Jr. of NASA Langley, Prof. Luigi Morino, Dr. Thomas A."

This is the Proceedings of the Taniguchi International Symposium on "Relaxation of Elementary Excitations" which was held October 12-16,1979, at Susono-shi (at the foot of f1t. Fuji) in Japan. The pleasant atmosphere of the Symposium is evidenced in the picture of the participants shown on the next page. The purpose of the symposium was to provide an opportunity for a limited number of active researchers to meet and to discuss relaxation processes and related phenomena not only of excitons and phonons in solids but also electronic and vibrational excitations in molecules and biological systems. First, the lattice relaxation, i.e., multi-phonon process, associated with electronic excitation, which plays important roles in self-trapping of an exciton and a particle (electron and hole) and also in degradation of semi conductor lasers, is discussed. Second, this lattice relaxation is studied as the intermediate state interaction in the second-order optical responses, i.e., in connection with the competitive behavior of Raman scattering and luminescence. Third, relaxation mechanisms and relaxation constants are by spectroscopic methods as well as by genuine nonlinear optical determined phenomena. Conversely the relaxation is decisive in coherent nonlinear optical phenomena such as laser, superradiance, and optical bistability. Fourth, the role played by relaxation processes is discussed for optical phenomena in macromolecules and biological system such as photosynthesis."

The planning for the IUTAM Symposium on Adiabatic Waves in Liquid-Vapor Systems began in May of 1986 in G5ttingen. The Symposium was held in August of 1989 in the Max-Planck-Institut fUr Str5mungsforschung. The invitations to participants suggested that the written papers concern Fast Adiabatic Phase Changes in Fluids and Related Phenomena. Particular topics suggested were: Liquefaction shockwaves and Shock splitting; Evaporation waves; Condensation in Laval nozzles and turbines; Stability in multiphase shocks; Non-equilibrium and near-critical phenomena; Nucleation in dynamic systems; Structure of transition layers; Acoustic phenomena in two phase systems and Cavitation waves. All of these topics should have been treated with emphasis on physical results, new phenomena and theoretical models. Participants from fourteen nations took part in the Symposium and presented papers which were within the range of suggested topics. The organization and execution of the Symposium was performed by the Max-Planck-Institut fUr Str5mungsforschung in G5ttingen. In particular, the meeting has been promoted under the leadership of Professor Dr. E.-A. MUller, who has for many years given his support for international exchanges in science. The detailed work of organization up to and during the Symposium was in large part due to Dr. T. Kowalewski, who served as Symposium Secretary."

Gas-phase photoacoustics are treated comprehensively for the first time in this book. Review articles by leading scientists in the respective research areas introduce their fields, review present knowledge and conclude with the latest developments and future prospects. Topics covered include the theory of photoacoustics in the frequency and time domains, acoustic resonator models, a great variety of experimental setups and techniques, studies of spectrocopy and fundamental kinetic processes such as energy transfer and chemical reactions, and applications such as air and exhaust monitoring and trace gas detection in biology and agriculture. The book will interest newcomers to photoacoustics, since it gives an overview of the important directions of current research and detailed descriptions of experimental methods. It will also be a valuable source of information for those already involved in photoacoustic research due to its clear presentation of theory and experimental results. All relevant literature references in this rapidly expanding field of laser applications are included.

It is universally recognized that the end of the current and the beginning of the next century will be characterized by a radical change in the existing trends in the economic development of all countries and a transition to new principles of economic management on the basis of a resource and energy conservation policy. Thus there is an urgent necessity to study methods, technical aids and economic consequences of this change, and particularly, to determine the possible amounts of energy resources which could be conserved (energy "reserves") in different spheres of the national economy. An increased interest towards energy conservation in industry, one of the largest energy consumers, is quite natural and is manifested by the large num ber of publications on this topic. But the majority of publications are devoted to the solution of narrowly defined problems, determination of energy reserves in specific processes and plants, efficiency estimation of individual energy conserva tion measures, etc. However, it is necessary to develop a general methodological approach to the solution of such problems and create a scientific and methodical base for realizing an energy conservation policy. Such an effort is made in this book, which is concerned with methods for studying energy use efficiency in technological processes and estimation of the theoretical and actual energy reserves in a given process, technology, or industrial sector on the basis of their complete energy balances."

The fourth Nishinomiya-Yukawa Memorial Symposium, devoted to the topic of dynamics and patterns in complex fluids, was held on October 26 and 27, 1989, in Nishinomiya City, Japan, where ten invited speakers gave their lectures. A one-day meeting, comprising short talks and poster sessions, was then held on the same topic on October 28 at the Research Institute for Fundamental Physics, Kyoto University. The present volume contains the 10 invited papers and 38 contributed papers presented at these two meetings. The symposium was sponsored by Nishinomiya City, where Prof. Hideki Yukawa once lived and where he wrote the celebrated paper describing the work that was later honored by a Nobel prize. The topic of the fourth symposium was chosen from one of the most vigorously evolving and highly interdisciplinary fields in condensed matter physics. The field of complex fluids is very diverse and still in its infancy and, as a result, the definition of a complex fluid varies greatly from one researcher to the next. One of the objectives of the symposium was to clarify its definition by explicitly posing a number of potentially rich problems waiting to be explored. Indeed, experimentalists are disclosing a variety of intriguing dynamical phenomena in complex systems such as polymers, liquid crystals, gels, colloids, and surfactant systems. We, the organizers, hope that the symposium will contribute to the increasing importance of the field in the coming years.

A good deal of the material presented in this book has been prepared by top experts in the field lecturing in January 1987 at the Winter School on Solitons in Tiruchirapalli, India. The lectures begin at an elementary level but go on to include even the most recent developments in the field. The book makes a handy introduction to the various facets of the soliton concept, and will be useful both to newcomers to the field and to researchers who are interested in developments in new branches of physics and mathematics

This volume is the proceedings of the Hiroshima Symposium on Elementary Excitations in Quantum Fluids, which was held on August 17 and 18, 1987, in Hiroshima, Japan, and was attended by thirty-two scientists from seven countries. Quantum fluids have been the subject of intense study as a consequence of their superfluid properties at very low temperatures. Elementary excitations in them are an important concept about which many important discoveries have been made in recent years. This symposium was arranged by a group of physicists from Hiroshima University to provide an opportunity to discuss these recent developments. It was conceived as a satellite conference of the 18th International Conference on Low Temperature Physics (LT 18), which was held in Kyoto, August 20-26, 1987. Emphasis was placed on the dynamic structures and correlations of ele mentary excitations, which resulted in invited speakers being selected from this field. However, enthusiastic contributors reported notable new results on various other aspects of the elementary excitations, which made the sympo sium lively and successful. It is our great satisfaction to present this volume, which includes papers of good quality and originality. We thank all the parti cipants for their cooperation throughout this symposium, and for preparing their manuscripts within a reasonable time."