Elucidation of the various mechanisms responsible for fracture in different materials was the general subject of the Fourth Annual Symposium on Fundamental Phenomena in the Materials Sciences held January 31 and February 1, 1966, in Boston and sponsored by the Ilikon Corporation of Natick, Massachusetts. In an analysis of the brittle-to-ductile transition in polycrystalline metals, T. L. Johnston (Ford Motor Company) placed major emphasis on factors related to the plastic resistance associated with grain boundaries and the effects of plastic anisotropy. Utilizing a generalized form of the Griffith criterion, he said it can be readily shown that several individual factors may be made reasonably quantitative and that the nature of plastic response can be predicted. Specifically, it can be shown that a critical factor relates to the length of a plastic shear zone which is constrained by an elastically loaded matrix. As this length increases, the Griffith inequality is satisfied and brittle failure occurs; however, the use of decreased grain sizes or the refine ment of dislocation or twin distribution can further tend to "homoge nize" the plastic flow and to decrease the magnitude of the shear zone. Of considerable importance in the consideration of plastic resistance is the availability of favorably oriented slip systems in aa un sheared crystallite."

Although polypropylene has been marketed since the 1950s, research and development in this area is still vigorous. The consumption of polypropylene over the years has been relatively high, mainly due to the steady improvement of its property profile. Polypropylene: Structures, Blends and Composites, in three separate volumes, reflects on the key factors which have contributed to the success of polypropylene, dealing with all aspects of structure-performance relationships relevant to thermoplastic polymers and related composites. Volume 1, Structure and Morphology, deals with polymorphism in polypropylene homo- and copolymers, where molecular and supermolecular structures are covered, and the processing-induced structure development of polypropylene, showing the interrelation between the processing-induced morphology and mechanical performance. Volume 2, Copolymers and Blends, contains comprehensive surveys of the nucleation and crystallisation behaviour of the related systems. It includes the development of morphology and its effects on rheological and mechanical properties of polypropylene-based alloys and blends and a review of polypropylene-based thermoplastic elastomers. Volume 3, Composites, gives a comprehensive overview of filled and reinforced systems with polypropylene as a matrix material, with the main emphasis on processing-structure-property-interrelationships. Chapters cover all aspects of particulate filled, chopped fibre-, fibre mat- and continuous fibre-reinforced composites. Interfacial phenomena, such as adhesion, wetting and interfacial crystallisation, are also included as important aspects of this subject.

This volume collects the contributions! to the NATO Advanced Study Institute (ASI) held in Aussois (France) by March 25 - April 5, 1991. This NATO ASI was intended to present and illustrate recent advances in computer simulation techniques applied to the study of materials science problems. Introductory lectures have been devoted to classical simulations with special reference to recent technical improvements, in view of their application to complex systems (glasses, molecular systems . . . ). Several other lectures and seminars focused on the methods of elaboration of interatomic potentials and to a critical presentation of quantum simulation techniques. On the other hand, seminars and poster sessions offered the opportunity to discuss the results of a great variety of simulation studies dealing with materials and complex systems. We hope that these proceedings will be of some help for those interested in simulations of material properties. The scientific committee advises have been of crucial importance in determining the conference program. The directors of the ASI express their gratitude to the colleagues who have participated to the committee: Y. Adda, A. Bellemans, G. BIeris, J. Castaing, C. R. A. Catlow, G. Ciccotti, J. Friedel, M. Gillan, J. P. Hansen, M. L. Klein, G. Martin, S. Nose, L. Rull-Fernandez, J. Valleau, J. Villain. The main financial support has been provided by the NATO Scientific Affairs Division and the Commission of European Communities (plan Science).

Nanotribology: Critical Assessment and Research Needs is an excellent reference for both academic and industrial researchers working in the fields of nanotechnology, tribology, mechanical engineering, materials science and engineering, MEMS, NEMS, magnetic recording, and biomedical devices. It will also be of interest to those pursuing scanning probe microscopy, nanoimaging, mesomanufacturing, sensors, actuators, aerospace, defense (controllers, microsystems), and military systems. Nanotribology: Critical Assessment and Research Needs provides a critical assessment of the current state of the art of nanotribology within the context of MEMS, mesomanufacturing, nanotechnology and microsystems. It contains chapters written by the leading experts in these fields. It identifies gaps in current knowledge and barriers to applications, and recommends research areas that need to be addressed to enable the rapid development of technologies.

This book is about thin films; what they are, how they are prepared, how they are characterized, and what they are used for. The contents of this book not only showcase the diversity of thin films, but also reveals the commonality among the work performed in a variety of areas. The chapters in this volume are based on invited papers presented by prominent researchers in the field at a Symposium on "Thin Films: Preparation, Characterization, Applications" at the 221st National Meeting of the American Chemical Society held in San Diego, California. The coverage of the symposium was extensive; topics ranged from highly-ordered metal adlayers on well-defined electrode surfaces to bio-organic films on non-metallic nanoparticles. An objective of this book is for the readers to be able to draw from the experience and results of others in order to improve and expand the understanding of the science and technology of their own thin films systems.

Technological advances in semiconductor growth has opened a broad horizon for semiconductor physics and applications during the past 20 years. High quality two-. dimensional systems are achieved with nearly atomic precision by direct epitaxial growth. Such structures led to novel applications like low noise high frequency modulation doped field effect transistors and quantum well lasers. Semiconductor heterostructures of lower dimensionality like quantum wires and quantum dots are not yet as mature, partly due to the lack in precision oflateral structuring technology. In recent years, however, there was an enormous progress in novel epitaxial growth methods. This opens a wide new area of basic and applied semiconductor physics with the hope of novel applications in near future making use of the advantageous properties of one- and zero-dimensional systems. Ideas for future device applications mainly stem from the altered density of states being discrete or atomic-like for quantum dots. Optical spectroscopy has played and is playing a crucial role in the advancement of this fascinating field of semiconductor physics. The NATO school organized at Bilkent University in Ankara and in Antalya brought together experts in this field and newcomers, especially young Ph. D. students and postdocs, to learn about recent developments and to discuss open questions in the area of optical spectroscopy of low dimensional semiconductors. The school turned out to be extremely fruitful and there was a great enthusiasm among the lecturers and students during the whole two weeks.

teacher Professor Ernst-Joachim Ivers to whom I still owe many insights 20 years after the end of his working life. This English edition is not an unedited translation of the German edition of 1990. The text has been substantially revised in some chapters, taking into account the literature published in the mean time. I wish to thank Dr.-Ing. H. Finken, Freiberg, who has prepared the translation from German into English with deep scientific understanding and in close contact with the author. I also wish to express my gratitude to Chapman & Hall for their support to this project without which the English edition could not have been published. Dr.-Ing. habil. C. Bernhardt Freiberg 1 Position, tasks and structure of particle size analysis Today the concept of particle size analysis is that of a special field of particle measurement technology, which in turn is part of particulate technology. This classification has developed over the last 20 years; it is the result of a scientific integration process taking place in many industrialized countries of the world. In recent years, the meaning and mutual connection of the related concepts as well as the tasks of the scientific disciplines designated by them have been the subject of intensive discussion which, however, has not led to a generally accepted terminology.

Over the past few years there has been a significant growth in the commercial application of a variety of processes which are all essentially based upon the very rapid heat treatment of powdered solid material in dilute gas suspensions. The objective of flash heating is usually to create a desirable product by means of physical and/or chemical transformations in the solid phase, usually with a high degree of control and with lower specific energy consumption than dense phase systems. Examples of successful flash reaction processing are to be found in the areas ofpyrometallurgy, mineral processing, plasma processing and, most recently, rapid prototyping. These developments have been based on, and have inspired, an expansion in fundamental research activities. As our understanding of flash reaction technology improves so does the need increase for the review of progress and the dissemination of accumulated knowl edge. Previous stocktaking on selected areas of flash reaction technology occurred in 1988 and can be found in the proceedings of three conferences held in that year: Flash Reaction Processes, Eds. D.G.C.Robertson, H.y'Sohn and N.J.Themelis, published by the Center for Pyrometallurgy, University of Missouri-Rolla, Rolla, MO 65401-0249; Production and Processing of Fine Particles, Ed. A.J .Plumpton, Pergamon Press, LeN 88-22755; High Temperature Dust-Laden Jets in Plasma Technology, Eds. O.P.Solonenko and A.I.Fedorchenko, VSP, Utrecht, ISBN 90- 6764-120-0."

A fundamental knowledge and understanding of dental materials is an absolute requisite to performing optimal dental care. This tenet is true not only for general dentists, but also for specialists alike. It is true not only for the developing dental student, but also for the practicing dentist. It is clearly evident that the authors of Dental Biomaterials have both an in-depth knowledge of dental materials and a fundamental appreciation for the importance of this information in contemporary clinical dentistry. Owing to the broad range of expertise of the authors, this textbook distinguishes itself from most dental materials texts by its remarkable ability to address a myriad of dental materials in the context of actual clinical applications. Emphasizing the clinical significance of dental materials is an obvious and conspicuous goal of this text that pervades the entire content of its pages. In fact, to that end, the authors notably include numerous highlighted sections entitled "Dental Significance" throughout the chapters to underscore the clinical importance of the subject matter. This approach is exceptionally effective at fostering a basic understanding of dental materials for the dental student. It piques the interest without stifling the student with abstract concepts. This text also is a valuable and reliable resource for the practicing dentist.

This volume contains written versions of the papers presented at the Second Inter national Conference on Amorphous and Crystalline Silicon Carbide and Related Materials (ICACSC 1988), which was held at Santa Clara University on Decem ber 15 and 16, 1988. The conference followed the First ICACSC held at Howard University, Washington DC, in December 1987 and continued to provide an in ternational forum for discussion and exchange of ideas and results covering the current status of research on SiC and related materials. ICACSC 1988 attracted 105 participants from five countries. The substantial increase in the number of papers compared with the previous year is an indication of the growing interest in this field. Of the 45 papers presented at the conference, 36 refereed manuscripts are included in this volume, while the remaining 9 appear as abstracts. The six invited papers provide detailed reviews of recent results on amorphous and crystalline silicon carbide materials and devices, as well as diamond thin films. The volume is divided into six parts, each covering an important theme of the conference.

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.

Drying of Polymeric and Solid Materials shows for the first time how the process of drying can be enhanced by combining mathematical and numerical models with experiments. The main advantages of this method are a significant saving of time and money. Numerical modelling can predict the kinetics of drying and the profiles of liquid concentration through the solid. This helps in the selection of optimal operational conditions. The simulation of the process is also crucial in the assessment of diffusity and the rate of evaporation.

Science and art of crystal growth represent an interdisciplinary activity based on fundamental principles of physics, chemistry and crystallography. Crystal growth has contributed over the years essentially to a widening of knowledge in its basic disciplines and has penetrated practically into all fields of experimental natural sciences. It has acted, more over, in a steadily increasing manner as a link between science and technology as can be seen best, for example, from the achievements in modern microelectronics. The aim of the course "Crystal Growth in Science and Technology" being to stress the interdisciplinary character of the subject, selected fundamental principles are reviewed in the following contributions and cross links between basic and applied aspects are illustrated. It is a very well-known fact that the intensive development of crystal growth has led to a progressive narrowing of interests in highly specialized directions which is in particular harmful to young research scientists. The organizers of the course did sincerely hope that the program would help to broaden up the horizon of the participants. It was equally their wish to contribute within the traditional spirit of the school of crystallography in Erice to the promotion of mutual understanding, personal friendship and future collaboration between all those who were present at the school.

This book represents the work presented at a NATO Advanced Research Workshop on "Metallization and Metal-Semiconductor Interfaces", held at the Technical University of Munich, Garching, W. Germany from 22-26 August 1988. The major focus of the workshop was to evaluate critically the progress made in the area of metal-semiconductor interfaces. The underlying theme was the mechanism of Schottky barrier formation and a serious as sessment of the various models. A significant fraction of the workshop time was also spent in discussing the interaction of alkali metals with semiconductors. Alkali metals on semi conductors form ordered overlayers and the resulting system often exhibits one-dimensional metallic properties. The nature of their interaction has introduced new and exciting com plexities and this was pursued at length during the lively discussions at the workshop. A half a day was devoted to Scanning Tunneling Microscopy, the emphasis being on its utility in providing structural and electronic character of low-coverage regime. The book should pro vide readers with the most current status of the research activity in the general area of metal-semiconductor interfaces at an international level. It should also serve as an excellent introduction to the field, since sufficient review type of material has also been included The workshop organizers, Dr. I. P. Batra (Director), mM Almaden Research Center, San Jose, Prof. S. Ciraci, Bilkent University, Ankara, Prof. C. Y. Pong, University of California, Davis, Prof. Dr. F. Koch (Local Chairman), Technical University Munich, Garching, Dr. H.

Surface science has existed as a recognized discipline for more than 20 years. During this period, the subject has expanded in two important ways. On the one hand, the techniques available for studying surfaces, both experimental and theoretical, have grown in number and in sophistication. On the other hand, surface science has been applied to an increasing number of areas of technology, such as catalysis, semicon ductor processing, new materials development, corrosion prevention, adhesion and tribology. . There is, however, no sharp division between fundamental and applied surface science. New techniques can immediately be applied to technologically important problems. Improvements in understanding of fundamental phenomena such as epi taxial growth of one metal on another, or the bonding of hydrocarbons to metal sur faces, to name just two examples, have direct consequences for technology. Surface science has also become very much an interdisciplinary subject; physics, chemistry, materials science, chemical and electronical engineering all draw upon and contribute to surface science. The intimate relationship between principles and applications of surface science forms the theme of this proceedings volume. The contributions were all presented as invited lectures at an Australian-German Workshop on Surface Science held at Coogee Beach, Sydney, Australia, in December 1991. The contributors, all active surface scientists in their respective countries, were asked to highlight recent develop ments in their own areas of activity involving new techniques, advances in funda mental understanding or new applications in technology."

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."

This volume contains of the proceedings of the CECAM {Centre d'Etudes de Calcul Atomique et Moleculaire} workshop on "Ab Initio Calculation of Phonon Spectra" which took place at the campus of the University of Antwerpen (Universitaire Instelling Antwerpen) on June 4 and 5, 1981. This workshop was sponsored by the Universitaire Instelling Antwerpen, by the Belgian "Nationaal Fonds voor Weten- schappelijk Onderzoek" and the Belgian Ministry of Education and Cultural Affairs. Although the calculation of phonon spectra in a solid has long been known to solid state physicists, it is only in the last decade that a macroscopic theory which treats the response of the electrons to the vibrations of the ions has been developed in a successful way. In the case of semiconductors numerical calculations of phonon frequencies were not performed until very recently due to the complex- ity of the problem. The correct treatment of the electron in the crystal has also led to an investigation of electron-phonon inter- action, including many body effects. Success has been achieved in the calculation of phonon anomalies and the coupling parameters in transition metals. In the case of surfaces the conductions for the appearance of electronic instabilities and the coupling of the resulting charge density wave to the lattice have been studied.

The general objective of the Tenth Canadian Fracture Conference was to respond to progress in the engineering sciences - in particular with r- pect to rapidly developing new trends in the theory and methodology of researcr and designing - and to the resulting needs of practical engineering in the specific field of fracture mechanics and related areas of engineering mechanics. The basic underlying issue is the theory and practice of physical analytical and iconic (reduced) modelling of the actually involved physical processes and of the responses of physical bodies and systems to actual energy flow - a problem which is becoming dominant in all fields of the natural sciences. Accordingly, the theme of the CFCIO was "Modelling Problems in Crack Tip Mechanics," a well defined and limited subject, the scope of treatment of which can be as deep and as comprehensive as an in volved researcher wishes it to be."

Polyvinyl chloride has played a key role in the development of the plastics industry over the past 40 years and continues to be a polymer of major importance. The reasons for its enormous versatility and range of application derive from a combination of the basic structure which gives rise to a relatively tough and rigid material and its ability to accept a range of plasticisers and other additives which can modify its physical characteristics to produce a range of flexible products. Two major problems, however, have tested the skill and ingenuity of PVC technologists since earliest times. One is the thermal instability of the material at the temperatures required for melt processing and fabrication, and the second is the photochemical instability which until recently has limited the potentially large range of outdoor applications. Both problems have been handled in a commercially satisfactory way by the gradual development of a range of stabilisers, lubricants and other processing aids and the high quality material which has resulted has led to massive utilisation of PVC by industry. Totally adequate stabilisation requires a detailed understanding of the mechanisms by which degradation processes are initiated and propagated. Although great advances have been made in this respect in recent years the problem remains incompletely understood. This book presents an account of the present position and the problems which remain to be solved.

Our rationale for the second edition remains the same as for the first edition, which appeared over twenty years ago. This is to offer simplified, useful and easily understood methods for dealing with the creep of components operating under conditions met in practice. When the first edition was written, we could not claim that the methods which were introduced were well-tried. They were somewhat conjectural, although firmly based, but not sufficiently well devel oped. Since that time, the Reference Stress Methods (RSM) introduced in the book have received much scrutiny and development. The best recognition we could have of the original methods is the fact that they are now firmly embedded in codes of practice. Hopefully, we have now gone a long way towards achieving our original objectives. There are major additions to this second edition which should help to justify our claims. These include further clarification regarding Reference Stress Methods in Chapter 4. There are also new topics which depend on RSM in varying degrees: * Creep fracture is covered in Chapter 7, where methods for assessing creep crack initiation and crack growth are fully described. This chapter starts with a review of the basic concepts of fracture mechanics and follows with useful, approximate methods, compatible with the needs of design for creep and the availability of standard data. * Creep/fatigue interactions and environmental effects appear in Chapter 8.

Polymer Latices, Second Edition is a comprehensive update of the previous edition, High Polymer Latices, taking into account the many developments since it was first published in 1966. It is the only publication to provide such an outstanding and extensive review of latex science and technology, from background theory and principles, to modern day applications. It will prove an invaluable reference source for all those working in the area of latex science and technology, such as colloid chemists, polymer scientists, and materials processors.

Although in nature the vast majority of polymers are condensation polymers, much publicity has been focused on functionalized vinyl polymers. Functional Condensation Polymers fulfills the need to explore these polymers which form an increasingly important and diverse foundation in the search for new materials in the twentyfirst century. Some of the advantages condensation polymers hold over vinyl polymers include offering different kinds of binding sites, their ability to be made biodegradable, and their different reactivities with various reagents under diverse reaction conditions. They also offer better tailoring of end-products, different tendencies (such as fiber formation), and different physical and chemical properties. Some of the main areas emphasized include dendrimers, control release of drugs, nanostructure materials, controlled biomedical recognition, and controllable electrolyte and electrical properties.

Stress corrosion cracking, including hydrogen embrittlement, has probably attracted more attention in the last decade than any other single facet of the many that constitute the totality of the environment sensitive behaviour of materials. To some this is because the complex interactions between a number of parameters, particularly metal composition and structure, electrochemistry and the response of a metal to the application of stress, make the subject of stress corrosion fascinating. To others it is be cause the subject has become increasingly important in practical terms, as the problem of general corrosion has been controlled and the borderline conditions between widespread attack and com plete inactivity are more frequently encountered, and as materials have become more efficiently used by operating at higher stress levels than hitherto. Particularly in advanced engineering systems, such as pressure vessels used in transportation or in the chemical process industries or in the sophisticated equipment used in some of the energy producing industries, the incidence of stress corro sion failure has increased alarmingly in recent times and with consequences that are extremely costly if not worse. The reasons for holding a NATO Advanced Study Institute in this field are therefore obvious, but why publish the proceedings of the Institute in an age where there is, arguably, already a VIII superfluity of published material? Obe obvious answer is that the papers presented constitute valuable reviews of detailed develop ments in recent times."

This is the first book in a new series - "Materials Research and Engineering" - devoted to the science and technology of materials. "Materials Research and Engineering" evolves from a previous series on "Reine und Angewand te Metallkunde" ("Pure and Applied Metallurgy"), which was edited by Werner Koster until his eightieth birthday in 1976. Although the present series is an outgrowth of the earlier one, it should not and cannot be regarded as a continuation. There had to be a shift of scope - and a change in presentation as well. Metallurgy is no longer an isolated art and science. Rather, it is linked by its scientific basis and tech nological implications to non-metallic and composite materials, as well as to processes for production, refining, shaping, surface treatment, and appli cation. Thus, the new series, "Materials Research and Engineering," will present up-to-date information on scientific and technological progress, as well as on issues of general relevance within the engineering field and industrial society. Premiering the new series, the present book by Dieter Altenpohl gives the reader a very general outlook, in fact, a position analysis of materials and the materials industry within the framework of our contemporary technological environment. It ventures, moreover, to forecast the changes affecting this pattern in a dynamic, interdependent world. This may be an unusual way to start a scientific series - it is believed, nevertheless, to be an appropriate one."

This is the second volume of Advances in Acoustic Microscopy. It continues the aim of presenting applications and developments of techniques that are related to high-resolution acoustic imaging. We are very grateful to the authors who have devoted considerable time to preparing these chapters, each of which describes a field of growing importance. Laboratories that have high-performance acoustic microscopes are frequently asked to examine samples for which the highest available resolution is not necessary, and the ability to penetrate opaque layers is more significant. Such applications can be thought of as bridging the gap be tween acoustic microscopy at low gigahertz frequencies, and on the one hand nondestructive testing of materials at low megahertz frequencies and on the other hand medical ultrasonic imaging at low megahertz frequencies. Commercial acoustic microscopes are becoming increasingly available and popular for such applications. We are therefore delighted to be able to begin the volume with chapters from each of those two fields. The first chapter, by Gabriele Pfannschmidt, describes uses of acoustic microscopy in the semiconductor industry. It provides a splendid balance to the opening chapter of Volume 1, which came from a national research center, being written from within a major European electronics industry itself. Dr Pfann schmidt describes the use of two quite different types of acoustic microscopes, and points out the advantages of each for specific purposes.