In the study of short-wave diffraction problems, asymptotic methods - the ray method, the parabolic equation method, and its further development as the "etalon" (model) problem method - play an important role. These are the meth ods to be treated in this book. The applications of asymptotic methods in the theory of wave phenomena are still far from being exhausted, and we hope that the techniques set forth here will help in solving a number of problems of interest in acoustics, geophysics, the physics of electromagnetic waves, and perhaps in quantum mechanics. In addition, the book may be of use to the mathematician interested in contemporary problems of mathematical physics. Each chapter has been annotated. These notes give a brief history of the problem and cite references dealing with the content of that particular chapter. The main text mentions only those pUblications that explain a given argument or a specific calculation. In an effort to save work for the reader who is interested in only some of the problems considered in this book, we have included a flow chart indicating the interdependence of chapters and sections."

A broad overview of recent developments in computer simulation studies of condensed matter systems is provided in this book. Both classical and quantum systems are discussed. The contributions present new physical results and describe new simulation techniques and novel ways of interpreting simulational data. Topics covered include: - parallelization and vectorization - cellular automata, fractals and aggregation - damage spreading - molecular dynamics of proteins and rotating molecules in solids - quantum Monte Carlo studies of strongly correlated electron systems

A special survey of the extensive field of Constitutive Laws is given in 11 lectures, divided into three parts: Thermodynamics of Materials, Stochastic Processes and Material Behaviour, Constitutive Relations for Simple Fluids and Microphysics of Solids. The collection of lectures comprehends a novel survey of thermodynamical constitutive theories, and contributions to material theories with after-effects including experiments, stochastic constitutive laws, molecular dynamics for simulating material properties, electrodynamical constitutive properties, and thermodynamic and microphysical modelling of polymers. The selected lectures emphasize the microstructural aspect of constitutive laws, and this collection presents a new facet of constitutive laws.

Clusters of Atoms and Molecules I is devoted to theoretical concepts and experimental techniques important in the rapidly expanding field of cluster science. Cluster properties are dicussed for clusters composed of alkali metals, semiconductors, transition metals, carbon, oxides and halides of alkali metals, rare gases, and neutral molecules. The book contains several well-integrated treatments, all prepared by experts. Each contribution starts out as simple as possible and ends with the latest results, so that the book can serve as a text for a course, an introduction into the field, or as a reference book for the expert.

Progress in Pacific Polymer Science 3 continues the record of the current status of major topics in polymer science.
The invited lecturers cover the following topics:
- Adding Value to Natural Polymers
- Polymers and the Environment
- Polymers in Mining and Mineral Processing
- Multicomponent Polymer Systems
- Characterization, Properties and Processing
- Functional Polymers
- Polymers for Medical Applications
- Polymer Recycling
- Polymer Surfaces of Biological Significance
- New and Advanced Polymer Materials

Polymeric materials have special advantages over other materials used for the recording, storage and retrieval of information, telecommunication transmission and visualization of images. The authors describe the synthesis, the physico-chemical behavior and the applications of these highly sensitive macromolecular systems. They discuss the most essential developments in this field.
For scientists and professionals working in the field of electrooptical and photooptical polymeric materials.

The 1984 Advanced Study Institute on "Electronic Structure, Dynamics and Quantum Structural Properties of Condensed Matter" took place at the Corsendonk Conference Center, close to the City of Antwerpen, from July 16 till 27, 1984. This NATO Advanced Study Institute was motivated by the research in my Institute, where, in 1971, a project was started on "ab-initio" phonon calculations in Silicon. I~ is my pleasure to thank several instances and people who made this ASI possible. First of all, the sponsor of the Institute, the NATO Scientific Committee. Next, the co-sponsors: Agfa-Gevaert, Bell Telephone Mfg. Co. N.V., C & A, Esso Belgium*, CDC Belgium, Janssens Pharmaceutica, Kredietbank and the Scientific Office of the U.S. Army. Special thanks are due to Dr. P. Van Camp and Drs. H. Nachtegaele, who, over several months, prepared the practical aspects of the ASI with the secretarial help of Mrs. R.-M. Vandekerkhof. I also like to. thank Mrs. M. Cuyvers who prepared and organized the subject and material index and Mrs. H. Evans for typing-assist ance. I express particular gratitude to Mrs. F. Nedee, who, like in 1981 and 1982, has put the magnificent Corsendonk Conference Center at our disposal and to Mr. D. Van Der Brempt, Director of the Corsendonk Conference Center, for the efficient way in which he and his staff took care of the practical organization at the Conference Center.

In Bird of Passage by Rudolf Peierls, we find a paragraph in which he de scribes his Cambridge days in the 1930s: On these relativistic field theory] problems my main contacts were Dirac, and the younger theoreticians. These included in particular Nevill (now Sir Nevill) Mott, perhaps the friendliest among many kind and friendly people we met then. Professor Kamimura became associated with Sir Rudolf Peierls in the 1950s, when he translated, with his colleagues, Peierls's 1955 textbook, Quantum Theory of Solids, into Japanese. This edition, to which Sir Rudolf himself contributed a preface, benefitted early generations of Japanese solid state physicists. Later in 1974/5, during a sabbatical year spent at the Cavendish Laboratory, Professor Kamimura met and began a long association with Sir Nevill Mott. In particular, they developed ideas for disordered systems. One of the outcomes is a paper coauthored by them on ESR-induced variable range hopping in doped semiconductors. A series of works on disordered systems, together with those on two-dimensional systems, have served as building blocks for Physics of Interacting Electrons in Disordered Systems, in the International Series of Monographs on Physics, coauthored by Aoki and published in 1989 by the Oxford University Press. Soon after Professor Kamimura obtained a D. Sc. in 1959 for the work on the ligand field theory under the supervision ofMasao Kotani, his strong con nections in the international physical community began when he worked at the Bell Telephone Laboratories in 1961/64."

Computer Simulation Studies in Condensed-Matter Physics IX covers recent developments in this field. This workshop was the ninth in this series and was held at the University of Georgia, March 4-9, 1996, and these proceedings form a record which is published with the goal of timely dissemination of the material to a wider audience. This volume is composed of three parts. The first section contains invited papers that deal with simulational studies of classical systems. The second section of the proceedings is devoted to invited papers on quantum systems, including new results for strongly correlated electron and quantum spin models. The final section comprises contributed presentations.

This volume contains papers presented at the Ninth International Conference on Ultrafast Phenomena held at Dana Point, CA, USA, from May 2 to 6, 1994. The biannual Ultrafast Phenomena Conferences provide a forum for discussion of the latest advances in ultrafast optics and applications in science and engineering. The vitality and excitement of the various disciplines sharing common interest in ultrafast phenomena were well represented at the meeting by the 438 participants from 18 countries, including 98 students. Cross-fertilization of ultrafast concepts and techniques among the various scientific and engineering disciplines continues to be the primary driving force behind this successful meeting. Progress was reported in the technology of generating ultrafast pulses, includ ing extensions in pulse width, output power, wavelength range, and intensity. Ultrafast spectroscopy continues to impact and expand the knowledge base of fundamental processes in physics, chemistry, biology, and engineering. A new series of lively, late-night panel discussions were introduced at this meeting, re flecting the maturing of the field into applications, while at the same time keeping a strong interest in fundamentals. Acknowledgements. Many people and organizations contributed to the success of this meeting. The members of the program committee deserve special thanks for reviewing all the papers and organizing the final program. The staff of the Opti cal Society of America very expertly took care of the conference arrangements."

This publication presents an up to date coverage of infrared thermography applied in the context of improved industrial activity and quality through automated inspection and control. It puts together concise and complete information on thermal non-destructive evaluation (NDE), a method for testing without damage, not yet available in an integrated, stand-alone format. All concepts discussed are explained in full and many industrial applications of the covered subjects are presented. Although the book is complete by itself extensive references to relevant research papers are given for further reading. Nondestructive Evaluation of Materials by Infrared Thermography is intended for a wide audience. It will help industrial engineers to implement nondestructive evaluation methods on the production line and enlarge their knowledge of industrial inspection techniques. It can also be used as a teaching aid at universities and colleges, especially in materials engineering curricula. Finally research centres will find it valuable as a reference book about thermal NDE.

Semiconductors can exhibit electrical instabilities like current runaway, threshold switching, current filamentation, or oscillations, when they are driven far from thermodynamic equilibrium. This book presents a coherent theoretical des- cription of such cooperative phenomena induced by generation and recombination processes of charge carriers in semicon- ductors.

Instrumental, especially spectrometric methods are widely used in analytical laboratories for identification and quantitative determination of complex organic systems. The author has shown this in earlier works for polymeric materials of all kind. In this book he describes the application of vibrational (FTIR, UV, Raman) and mass spectrometries and of other instrumental techniques for identification and structure elucidation of plastics additives, e.g., antioxidants, stabilisers, plasticisers, pigments, rubber chemicals. The state of the art is compressed in numerous tables and figures; these also allow the interpretation of spectra. Especially remarkable is a collection of the FTIR spectra of 780 selected additives, together with structures and legends. This book is especially useful for the practitioner in plastics processing and production as well as plastics additives industry for the quality control of educts.

The workshop on the "Molecular Basis of Polymer Networks", held October 5- 7, 1988 in 1iilich, FRG, continued a series of workshops jointly organized by the Institute Laue Langevin (ILL) in Grenoble, and the Institute of Solid State Physics of the KFA, 1iilich. The aim of this workshop was to provide a platform for discussions between theoreticians and experimentalists interested in the physics of polymer networks, in the hope that the two types of discussion would be synergistic. As revealed by the title of this workshop, the main focus of the lectures was on molecular aspects of the problem. The individual parts of these proceedings cover various approaches. Following quite general comments from a physicist examining the situation from "outside", various new theoretical concepts are developed. During the last decade the advent of Small Angle Neutron Scattering (SANS) has allowed the molecular structure of polymer networks to be studied and thus the reliability of the theories to be tested directly at the molecular level. Recent advances in this field are presented. The use of new techniques such as 2H NMR or QELS and the refinements of more classical, mechanical experimental measure ments have provided new information about the relation between the macroscopic behavior and the microscopic structure of polymer networks. Some recent results in this area are discussed for both chemically cross-linked networks and gels built by specific interchain interactions.

Computer Simulation Studies in Condensed-Matter Physics VII provides a broad overview of recent developments. Presented at the recent workshop, it contains the invited and contributed papers which describe new physical results, simulational techniques and ways of interpreting simulational data. Both classical and quantum systems are discussed.

This volume contains papers presented during the US-Japan seminar on "Solid Phase Epitaxy and Interface Kinetics" held in Oiso, Japan, June 20-24, 1983. This seminar was co-sponsored by the National Science Foun dation and Japan Society for the Promotion of Science and co-chaired by Professor S. Furukawa, Tokyo Insitute of Technology, and Professor J. W. Mayer, Cornell University. Extensive topics such as solid phase epitaxy, growth mechanisms and interface kinetics, silicon-on-insulator structures, silicide-on-Si sturctures, novel nanometer and layered devices, and so on were discussed and more than 50 papers were presented. Most papers were original ones with brief reviews added for the convenience of the readers at the editor's request. The editor classified these papers into two groups and compiled two volumes; "Silicon-on-Insulator (SOl): Its Technology and Applications" and "Layered Structures and Interface Kinetics: Their Technology and Ap plications." This volume mainly contains the papers related to epitaxial growth of metal, insulator and semiconductor films, growth mechanisms, interface kinetics, properties and applications of silicide films, and novel nanometer and layered devices. These papers offer basic properties of the layered structures and possibility of various applications of the structures to present and future semiconductor devices. The editor is indebted to our fellow contributors who agreed to par take in publishing the proceedings of the seminar, to Japanese principal par ticipants of the seminar for encouraging him to have the seminar and to compile these volumes, to Professor H. Ishiwara for his secretarial work throughout the seminar and the publication."

Dr. Boris Medovar, a member of the Soviet Academy of Sciences, is a promi nent member of the E.O. Paton Electric Welding Institute in Kiev, one of the pre-eminent institutes of the USSR. The Paton Institute, internationally famous for its entrepreneurial efforts in electrical welding processes, is also famous for its application of electrically based processes in melting and remelting of high alloy and high-temperature materials. These include the ESR (electroslag re melting) process, the ESC (electroslag casting) process, skull remelting based on electron-beam processes, plasma arc processes, and electric arc processes. Along with the ESR process for ingot production is the commercial plasma arc remelt process for specialty steels, particularly where high nitrogen contents may be desired, as in austenitic stainless steels. Major industrial centers are now scattered throughout the USSR and are a major factor in high-alloy, high strength, low- and high-temperature materials. The ESR process was developed in response to the Western development of the VAR (vacuum arc remelting) process for producing very highly alloyed materials during the growth period of the jet engine age. The V AR and ESR processes utilize different purification and refinement processes that are extremely critical in very highly, complexly alloyed superalloys and high-speed tool steels. In water-cooled remelt systems, they also achieve relatively rapid (directional) solidification, minimizing segregation and coarse phase separation of undesir able impurity elements or elements that tend to form coarse brittle phases."

This is the third book in the new series "Material Research and Engineering," devoted to the science and technology of materials. "MRE" evolves from a previous series on "Reine und Angewandte Metallkunde," which was edited by Werner Koster until his eightieth birthday in 1976. For the new series, the presentation as well as the scope had to be modified. In particular, the scientific and technological links between volumes on metallic, non-metallic, and composite materials should reflect the successful development of materials science and engineering within the last two decades. Thus, the material provided by Dorre and Hlibner for the present volume is partic ularly welcome. Alumina as a ceramic material has received very large attention as an object of scientific investigation in all of its aspects. Additionally, it plays a leading role as a nonmetallic material in many fields of technical appli cation. This book deals with both aspects: in Chapter 2 (physical properties) and 3 (me chanical properties), H. Hlibner presents an outstanding documentation of what one might call the science of alumina, based on 560 literature references and 15 years of personal experience gained from experimental and theoretical work in university laboratories in Erlangen, Rio de Janeiro, and Hamburg. In Chapter 4 (fabrication) and 5 (applications), E."

The Institut Max von Laue-Paul Langevin (ILL) in Grenoble regularly orga nizes workshops that deal with various applications of neutrons in physics, chemistry, biology and materials science. The workshop "Quantum Aspects of Molecular Motions in Solids" was jointly organized by the Institut Laue Langevin and the Institut fiir Festkorperforschung at the Kernforschungsan lage Jiilich and took place in September 1986 in Grenoble. Tunneling phenomena in molecular crystals were first observed with macro scopic methods like specific heat experiments and later also with NMR. Fi nally, the development of high resolution neutron scattering techniques like neutron backscattering led to direct spectroscopic observation of the tunnel split ground state. This breakthrough was achieved in 1975 at Jiilich. Since then the large variety of high-resolution techniques available in combination with high neutron flux have turned ILL into the leading laboratory in the field of tunneling spectroscopy. Since 1980 regular meetings of scientists involved in this topic have been organized every two years (Jiilich, Braunschweig, Nottingham) and have led to an intense exchange of ideas and experimental results. The present workshop is the fourth of this series and the first with published proceedings presenting the state of the art in this field. The eight review articles introduce scientists not involved in the subject to the actual discussion. Sessions on translational tunneling of light interstitials in metals as well as on tunneling phenomena in amorphous substances provide bridges to adjacent fields."

During the past thirty years considerable efforts have been made to design the synthesis and the study of molecular semiconductors. Molecular semiconductors - and more generally molecular materials - involve interactions between individual subunits which can be separately synthesized. Organic and metallo-organic derivatives are the basis of most of the molecular materials. A survey of the literature on molecular semiconductors leaves one rather confused. It does seem to be very difficult to correlate the molecular structure of these semiconductors with their experimental electrical properties. For inorganic materials a simple definition delimits a fairly homogeneous family. If an inorganic material has a conductivity intermediate between that of an 12 1 1 3 1 1 insulator " 10- n- cm- ) and that of a metal (> 10 n- cm- ), then it is a semiconductor and will exhibit the characteristic properties of this family, such as junction formation, photoconductivity, and the photovoltaic effect. For molecular compounds, such simplicity is certainly not the case. A huge number of molecular and macromolecular systems have been described which possess an intermediate conductivity. However, the various attempts which have been made to rationalize their properties have, more often than not, failed. Even very basic electrical properties such as the mechanism of the charge carrier formation or the nature and the density ofthe dopants are not known in detail. The study of molecular semiconductor junctions is very probably the most powerful approach to shed light on these problems.

This volume is based on lectures and contributed papers presented at the Eleventh Course of the International School of Materials Science and Tech nology that was held in Erice, Sicily, Italy at the Ettore Majorana Center for Scientific Culture during the period 6-17 July 1986. The subject of the course was "Electro-optic and Photorefractive Materials: Applications in Sig nal Processing and Phase Conjugation" . The fields of electro-optics and photorefraction have developed rapidly since the invention of lasers just over twenty-five years ago. The possibil of altering the optical properties of a material by electric fields or by ity optical waves is of great importance for both pure science and for practical applications such as optical signal processing, telecommunications and opti cal display devices. These effects allow us to manipulate (modulate, deflect) and process a given light wave. Modulation, deflection and processing of light waves by means of the electro-optic effect is of fundamental importance in fiber optic telecommuniC1. tions and sensor systems w here the light signals can be processed prior or subsequent to transmission through the fibers. Thin film electro-optic materials with suitable electrode arrays on. the surface of the wave-guiding structures result in a technology often referred to as inte grated optics. In principle, integrated optics devices allow miniaturization and integration of many operations onto a single chip. The photorefractive effect, defined as a photo-induced change of the in dices of refraction, was the other topic treated in this course."

In 1987 a major breakthrough occurred in materials science. A new family of materials was discovered that became superconducting above the temperature at which nitrogen gas liquifies, namely, 77 K or -196 DegreesC. Within months of the discovery, a wide variety of experimental techniques were brought to bear in order to measure the properties of these materials and to gain an understanding of why they superconduct at such high temperatures. Among the techniques used were electromagnetic absorption in both the normal and the superconducting states. The measurements enabled the determination of a wide variety of properties, and in some instances led to the observation of new effects not seen by other measu- ments, such as the existence of weak-link microwave absorption at low dc magnetic fields. The number of different properties and the degree of detail that can be obtained from magnetic field- and temperature-dependent studies of electromagnetic abso- tion are not widely appreciated. For example, these measurements can provide information on the band gap, critical fields, the H-T irreversibility line, the amount of trapped flux, and even information about the symmetry of the wave function of the Cooper pairs. It is possible to use low dc magnetic field-induced absorption of microwaves with derivative detection to verify the presence of superconductivity in a matter of minutes, and the measurements are often more straightforward than others. For example, they do not require the physical contact with the sample that is necessary when using four-probe resistivity to detect superconductivity.

As Chairmen of the Electrochemistry and Molten Salts Discussion Groups of the Chemical Society, it gave us great pleasure to welcome the confer ence Highly Concentrated Aqueous Solutions and Molten Salts, which our Groups cosponsored, at St. John's College, Oxford in July 1978. During the meeting the editors of the present volume, and those giving lectures, came to the conclusion that the verbal presentations deserved to be expanded and to be more widely disseminated in a permanent form. Thus the articles which appear in this volume were commissioned and prepared. A greater exchange of information between aqueous chemists and those concerned with molten salts is to be welcomed and to this end the present volume aims to focus attention on the borderline areas between the two in an attempt to facilitate a wider awareness of the concepts and methods appropriate to the respective specialities. Similarly, and parti cularly in the electrochemical field, a greater exchange of information be tween the academic and industrial practitioners of the subject is desirable. T!1e problems involved are not trivial but when the interactions in these largely (but not wholly) ionic liquids are better understood, this wiii surely be to the benefit of all concerned with solution chemistry. Douglas Inman, Imperial College Chairman, Electrochemistry Group David Kerridge, University of Southampton Chairman, Molten Salts Discussion Group v Preface A number of recent events led to the appearance of this text at this particu lar time.

This volume contains the talks presented at the International Symposium on Electronic Excitations and Interaction Processes in Organic Molecular Aggre gates which was held at Schloss Elmau, Bavaria, Germany from June 5 to June 10, 1983. In the recent years the investigation of organic materials has developed rapidly and has led to the construction of materials with interesting proper ties. The discovery of highly conducting and superconducting organic materials is definitely one of the reasons for the enormous increase in research acti vity in this field. Interesting applications have been realized or seem pos sible, such as the application of organic materials in electrophotography. The conductivity of organic polymers may be varied within a large range by doping and such materials have been used to construct an organic battery. Some time ago it was suggested that organic glasses and polymers could be used as stor age materials in computer technology. With the development of preparation tech niques and modern methods of investigation, for example, high resolution and picosecond spectroscopy, a large amount of experimental data is available not only for the conducting materials but also for organic semiconductors and in sulators. With this rapid accumulation of experimental material the microscopic theoretical understanding could not keep pace."

The growth and maturity of research in structural phase transitions (SPT) make it an appropriate subject for the Topics in Current Physics series. The maturing pro- cess is, however, by no means complete. New areas such as incommensurable SPT, quasi-low-dimensional systems, systems containing lattice disorder due to impuri- ties or as mixed crystals, multicritical points, and quantum effects have recently come under focus. The understanding of the dynamics, be it microscopic soft-mode theory or critical dynamics, more specifically the central-peak problem, is also still quite incomplete. On the other hand, there are areas which are genuinely conso 1 ida ted. On the theoreti ca 1 s ide~ these concern symmetry properti es, Landau theory, and the application of static renormalization theory to critical phenomena. ,Also, the use of various complementary experimental techniques, with their specific merits, are well in hand. The field of STP's and of the various methods of investigation range so widely that it appeared appropriate to invite a number of scientists to review their respective areas of experti se to which they have made s i gnifi cant contri butions.