Industrial radiography is a well-established non-destructive testing (NDT) method in which the basic principles were established many years ago. However, during 1993-95 the European Standards Organisa tion (CEN) commenced drafting many new standards on NDT including radiographic methods, and when completed these will replace national standards in all the EC member countries. In some cases these standards vary significantly from those in use in the UK at present. These CEN standards are accepted by majority, not unanimous voting, so they will become mandatory even in countries which vote against them. As most are likely to be legal by the time this second edition is published, they are described in the appropriate places in the text. The most important new technical development is the greater use of computers in radiology. In the first edition, computerized tomography was only briefly mentioned at the end of Chapter 11, as it was then largely a medical method with only a few equipments having found a place in industrial use. The method depends on a complex computer program and a large data store. Industrial equipments are now being built, although their spread into industry has been slow. Computer data storage is also being used for radiographic data. Small computers can now store all the data produced by scanning a radiographic film with a small light-spot, and various programs can be applied to these data."

Carbon fibre reinforced carbon composites form a very specialized group of materials. They may be considered as a development of the family of carbon fibre reinforced polymer composites which are becoming ever more prevalent in modern engineering. Since the early 1960s a large number of so-called 'advanced materials' have appeared on the scene. Carbon arbon is arguably the most successful of all these products finding many and varied applications. In the field of Formula 1 motor racing for example, the present levels of performance simply could not be achieved without the use of carbon-carbon brakes and clutches. Despite the materials' obvious assets, they have not, and will not, reach their full potential until their inherent problems of excessive production costs and oxidation resistance have been addressed properly. In this respect the 'carbon-carbon story', of much potential but only limited success, serves as a lesson to all those involved in materials research, development and application. In writing this book I have tried to set up a logical progression of what the materials are, how they are made, what their assets and deficiencies are, what they are used for and to what extent they are commercially exploited. Each specialized chapter may be considered in isolation or as part of a sequence, whereas the final chapter provides a summary of the principal concepts as well as a basic review of the economic situation past, present and, hopefully, future.

This volume contains the edited Proceedings of the Sixth World Round Table Conference on Sintering, held in Herceg-Novi, Yugoslavia on September 2-6, 1985. It was organized by the International Institute for the Science of Sintering (IISS), headquartered in Beograd. Every fourth year since 1969, the Institute has organized such a Round Table Conference on Sintering, each has taken place at some selected lo cation within Yugoslavia. A separate series of IISS Summer Schools have also been held at four year intervals, but they have been offset by about two years, so they occur between the main Conferences. As a rule, the Summer Schools have been devoted to more specific topics and they also take place in different countries. The aim of these Conferences and their related Summer Schools has been to bring together scientists from allover the world who work in various fields of science and technology concerned with sinter ing and sintered materials. A total of six IISS Conferences have been held over the period 1969-1985, and they have been supplemented by the three Summer Schools held in Yugoslavia, Poland and India (in 1975, 1979 and 1983, respectively). This most recent five day Conference addressed the fundamental scien tific background as well as the technological state-of-the-art in sintering and sintered materials. It encompassed many of the high technology sintered materials needed for a wide variety of research and industrial applications."

Most of the papers contained in this volume are based on pres entations made at the symposium on Catalytic Conversions of Synthesis Gas and Alcohols to Chemicals, which was held at the 17th Middle At lantic Regional Meeting of the American Chemical Society, April 6-8, 1983, in the setting of the Pocono Hershey Resort, White Haven, PA. I thank Dr. Ned D. Heindel, General Chairman, and Dr. Natalie Foster, Program Chairman, both of Lehigh University, for the invitation to organize the symposium. Financial support was received from Air Products and Chemicals, Inc. for the organization of the symposium, and acknowledgement is made to Air Products and Chemicals, Inc. and to the Donors of the Petroleum Research Fund, administered by the American Chemical Society, for partial support of the conduct of the symposium. The theme of this volume is the recent progress made in devel oping and understanding viable catalytic syntheses of chemicals di rectly from synthesis gas (CO + H2) or indirectly via alcohols. An aim of the symposium and of this volume is to provide a meaningful blend of applied and basic science and of the chemistry and engineer ing of processes that are, or hold promise to be, economically and industrially feasible. The topics demonstrate the increasing impor tance of synthesis gas as a versatile feedstock and emphasize the central role that alcohols, such as methanol, can playas chemical intermediates."

This volume (parts A and B) contains the edited papers presented at the annual Review of Progress in Quantitative NDE held at the University of California, San Diego, July 8-13, 1984. We have chosen to organize the papers by subject, an arrangement that we feel to be more useful for a reference volume than the order of paper presentation at the Review. To do this, topical subject headings have been selected under which the large majority of papers reasonably fall. These categories cover a broad spectrum of research in NDE and encompass activities from funda mental work to early engineering applications. The scope and depth of the Review may be easily assessed by examination of the Table of Contents. The Review was sponsored by the Center for Advanced NDE at the Ames Lab oratory of the U.S. Dept. of Energy in cooperation with the Office of Basic Energy Sciences, USDOE, the Materials Laboratory at Wright-Patterson AFB, and the Naval Sea Systems Command. Approximately 300 attendees re presenting various government agencies, industry, and universities parti cipated in the technical presentations, poster sessions, and discussions. This Review, possibly the most comprehensive annual symposium in NDE, provides a valuable forum for the timely exchange of technical informa tion. A few highlights of the Review are summarized in the following paragraphs."

This book originated out of the papers presented at the special symposium, "Electrochemistry in Transition-From the 20th to the 21st Century," scheduled by the Division of Colloid and Surface Science during the American Chemical Society meeting in Toronto. The symposium was in honor of Professor J. O'M. Bockris, who received the ACS award on "The Chemistry of Contemporary Technological Problems" (sponsored by Mobay Corporation) during this meeting and who also reached his 65th birthday in the same year. The symposium was of a multidisciplinary nature and encompassed the fields of theoretical and experimental elec trochemistry, surface science, spectroscopy, and electrochemical technology. The symposium also had an international flavor in that the participants represented several countries Australia, Belgium, Canada, Chile, England, Japan, Korea, the Netherlands, Poland, Switzer land, Venezuela, Yugoslavia, and the United States. The symposium was graciously sponsored by the ACS (Petroleum Research Fund and Division of Colloid and Surface Science), Alcan International, Dow Chemical Company, EG&G, Electrolyzer Corporation, Exxon, General Electric Company, IBM, Institute of Gas Technology, International Association of Hydrogen Energy, Johnson Matthey, Inc., Kerr-McGee Corporation, Medtronics, and Texas A&M University (Center for Electrochemical Systems and Hydrogen Research and the Hampton Robinson Fund). The "theme" of the papers presented at the symposium covered not only significant contributions made to electrochemistry in the twentieth century, but also "New Horizons in Electrochemistry" for the twenty-first century. Thus, the scientists who presented papers were invited to contribute chapters to this book, having the same titles as the symposium."

This publication presents the proceedings of the NATO Advanced Research Workshop (ARW) on Computer Modelling of Electronic and Atomic Processes in Solids. This ARW was held at Szklarska Poreba, Wroclaw, Poland from May 20 -23, 1996, and brought together scientists from Canada, England, Germany, Israel, Latvia, Poland, Russia, Switzerland, United States, Ukraine and Uzbekistan. The NATO Advanced Research Workshops program is designed to increase collaboration and exchange of knowledge between the Eastern and Western scientific communities. This particular NATO ARW has already succeeded in that effort, and has spawned collaboration agreements and programs. One joint project in space materials has led to the launch of an experiment to the Russian MIR space station. This NATO ARW was also fortunate to be held concurrently with a workshop of the Wroclaw Technical University, in the same location, which focused on glass materials, thus providing for a larger scientific audience for a number of presentations of both groups. The primary emphasis of this ARW was on computer models, ranging from fundamental atomic, molecular and electronic structures and processes, through to macroscopic descriptions of materials in terms of their structure and properties. Various elements discussed in these proceedings include environmental effects, predictions of properties, correlations with experiments and material performance parameters. Applications to space and electronics were emphasized.

Micro Electro Mechanical Systems (MEMS) is already about a billion dollars a year industry and is growing rapidly. So far major emphasis has been placed on the fabrication processes for various devices. There are serious issues related to tribology, mechanics, surfacechemistry and materials science in the operationand manufacturingof many MEMS devices and these issues are preventing an even faster commercialization. Very little is understood about tribology and mechanical properties on micro- to nanoscales of the materials used in the construction of MEMS devices. The MEMS community needs to be exposed to the state-of-the-artoftribology and vice versa. Fundamental understanding of friction/stiction, wear and the role of surface contamination and environmental debris in micro devices is required. There are significantadhesion, friction and wear issues in manufacturing and actual use, facing the MEMS industry. Very little is understood about the tribology of bulk silicon and polysilicon films used in the construction ofthese microdevices. These issues are based on surface phenomenaand cannotbe scaled down linearly and these become increasingly important with the small size of the devices. Continuum theory breaks down in the analyses, e. g. in fluid flow of micro-scale devices. Mechanical properties ofpolysilicon and other films are not well characterized. Roughness optimization can help in tribological improvements. Monolayers of lubricants and other materials need to be developed for ultra-low friction and near zero wear. Hard coatings and ion implantation techniques hold promise.

This volume contains the proceedings of the first International Conference on the Science of Hard Materials held in Moran, Wyoming, Aug. 23-28, 1981. The objective of the conference was to review and advance the state of knowledge of the basic physical and chemical properties of hard materials and show how these properties influence performance in a variety of applications. To this end, the 49 con tributed papers and the four keynote papers by Prof. Fischmeister and Drs. Hintermann, Exner and Almond, present an excellent overview of the state of the art in the "science" of hard materials. The contents of these proceedings also reflect the fact that hard metal technology is now well matured and several aspects of the behavior of these materials are well understood and firmly established. Structure-property relationships in this class of materials are currently well known. Pitfalls in some of the traditional test methods have been recognized and new test methods are being developed which discriminate between intrinsic material properties and flaw content and distribution. Application of fracture mechanics, al though a late corner to the hard materials area (as compared to other structural materials), is rapidly gaining acceptance and new fracture toughness test methods are being developed. Application of modern analysis and analytical techniques to these materials has begun and entirely new and unexpected information has been obtained. For a variety of reasons, "hard metals" have dominated the research and development scene of "hard materials.""

The characterization of materials and phenomena has historically been the principal limitation to the development in each area of science. Once what we are observing is well defined, a theoretical analysis rapidly follows. Modern theories of chemical bonding did not evolve until the methods of analytical chemistry had progressed to a point where the bulk stoichiometry of chemical compounds was firmly established. The great progress made during this century in understanding chemistry has followed directly from the development of an analytical chemistry based on the Dalton assumption of multiple proportions. It has only become apparent in recent years that the extension of our understanding of materials hinges on their non-stoichiometric nature. The world of non-Daltonian chemistry is very poorly understood at present because of our lack of ability to precisely characterize it. The emergence of materials science has only just occurred with our recognition of effects, which have been thought previously to be minor variations from ideality, as the principal phenomena controlling properties. The next step in the historical evolution of materials science must be the development of tools to characterize the often subtle phenomena which determine properties of materials. The various discussions of instrumental techniques presented in this book are excellent summaries for the state-of-the-art of materials characterization at this rather critical stage of materials science. The application of the tools described here, and those yet to be developed, holds the key to the development of this infant into a mature science.

The first edition was produced at a time when the advantages of studying oriented polymers were just becoming apparent. From a sci entific stand point it had been demonstrated that greater insight into both structure and properties could be obtained if an oriented polymer was prepared. From a technological viewpoint, major advances were under way, especially in high modulus and high strength fibres. Twenty years later, it is possible to review the scientific advances which have been made in this area and to provide much wider perspectives for the technology. As in the case of the first edition, the emphasis is on the methodologies available for characterizing oriented polymers and their mechanical behaviour. It is a particular pleasure to thank the contributing authors for their cooperation and Dr Philip Hastings of Chapman & Hall for his support and encouragement. I am also indebted to Professors A. H. Windle and D. C. Bassett for their respective contributions to sections 1. 3. 1 and 1. 3. 4. Although this chapter has been extensively revised, the contribution of the late Leslie Holliday to the first edition of this book is also acknowledged. Introduction 1 I. M. Ward 1. 1 THE PHENOMENON OF ORIENTATION Orientation in polymers is a phenomenon of great technical and theo retical importance. The word orientation itself conveys a number of ideas."

The principal aim of this text is to encourage the development and application of numerical modelling techniques as an aid to achieving greater efficiency and optimization of metal-forming processes. The contents of this book have therefore been carefully planned to provide both an introduction to the fundamental theory of material deformation simulation, and also a comprehensive survey of the "state-of-the-art" of deformation modelling techniques and their application to specific and industrially relevant processes. To this end, leading international figures in the field of material deformation research have been invited to contribute chapters on subjects on which they are acknowledged experts. The information in this book has been arranged in four parts: Part I deals with plasticity theory, Part II with various numerical modelling techniques, Part III with specific process applications and material phenomena and Part IV with integrated computer systems. The objective of Part I is to establish the underlying theory of material deformation on which the following chapters can build. It begins with a chapter which reviews the basic theories of classical plasticity and describes their analytical representations. The second chapter moves on to look at the theory of deforming materials and shows how these expressions may be used in numerical techniques. The last two chapters of Part I provide a review of isotropic plasticity and anisotropic plasticity.

This book contains th Proceedings of the World Conference of the International Nuclear Target Development Society held in Boston, October 1-3, 1979. Approximately seventy participants and registrants from the following countries attended this Conference: Belgium, Canada, Denmark, United Kingdom, German Federal Republic, Israel, Japan, The Netherlands, Saudi Arabia, Switzerland, and the United States. The Conference was sponsored by the New England Nuclear Corporation. Conference Chairman in residence was Jozef Jaklovsky who was assisted by the invited Co-Chairman D. Riel of the State University of New York at Stony Brook. This publication incorporates the proceedings of an inter national conference concentrating on the general field of target preparation for use with particle accelerators. The publication includes additional contributions on target preparations by honorary members of this Society. For the first time in this field, an extensive bibliography collection (1936-June 1980) is included. Bibliography, subject index, author index, country index, and patent index have been organized by the editor. The biblioqraphy includes thin and thick particle accelerator targets and also preparation and use of targets in particle accelerators."

Since the inception of this volume, the world's nancial climate has radically changed. Theemphasishasshiftedfromboomingeconomiesandeconomicgrowth totherealityofrecessionanddiminishingoutlook. Witheconomicdownturncomes opportunity,inallareasofchemistryfromresearchanddevelopmentthroughto productregistrationandriskassessment,replacementsarebeingsoughtforcostly time-consumingprocesses. Leadingamongstthereplacementsaremodelswithtrue predictivecapability. Ofthesecomputationalmodelsarepreferred. This volume addresses a broad need within various areas of the "chemical industries", from pharmaceuticals and pesticides to personal products to provide computationalmethodstopredicttheeffects,activitiesandpropertiesofmolecules. Itaddressestheuseofmodelstodesignnewmoleculesandassesstheirfateand effectsbothtotheenvironmentandtohumanhealth. Thereisanemphasisrunning throughoutthisvolumetoproducerobustmodelssuitableforpurpose. Thevolume aimstoallowthereaderto nddataanddescriptorsanddevelop,discoverandutilise validmodels. Gdansk, ' Poland TomaszPuzyn Jackson,MS,USA JerzyLeszczynski Liverpool,UK MarkT. D. Cronin May2009 CONTENTS Part I Theory of QSAR 1 QuantitativeStructure-ActivityRelationships(QSARs)- ApplicationsandMethodology...3 Mark T. D. Cronin 1. 1. Introduction...3 1. 2. PurposeofQSAR...4 1. 3. ApplicationsofQSAR...4 1. 4. Methods...5 1. 5. TheCornerstonesofSuccessfulPredictiveModels ...7 1. 6. AValidated(Q)SARoraValidPrediction? ...9 1. 7. UsinginSilicoTechniques ...9 1. 8. NewAreasforinSilicoModels...11 1. 9. Conclusions...11 References ...11 2 TheUseofQuantumMechanicsDerivedDescriptorsin ComputationalToxicology...13 Steven J. Enoch 2. 1. Introduction...13 2. 2. TheSchrodingerEquation...15 2. 3. Hartree-FockTheory...17 2. 4. Semi-EmpiricalMethods:AM1andRM1...18 2. 5. ABInitio:DensityFunctionalTheory...19 2. 6. QSARforNon-ReactiveMechanismsofAcute(Aquatic) Toxicity...19 2. 7. QSARsforReactiveToxicityMechanisms...21 2. 7. 1. AquaticToxicityandSkinSensitisation...21 2. 7. 2. QSARsforMutagenicity ...24 2. 8. FutureDirectionsandOutlook...25 2. 9. Conclusions...26 References ...26 vii viii Contents 3 MolecularDescriptors...29 Viviana Consonni and Roberto Todeschini 3. 1. Introduction...29 3. 1. 1. De nitions...29 3. 1. 2. History...31 3. 1. 3. Theoreticalvs. ExperimentalDescriptors...33 3. 2. MolecularRepresentation ...35 3. 3. TopologicalIndexes...38 3. 3. 1. MolecularGraphs...38 3. 3. 2. De nitionandCalculationofTopologicalIndexes(TIs) 39 3. 3. 3. Graph-TheoreticalMatrixes...42 3. 3. 4. ConnectivityIndexes ...48 3. 3. 5. CharacteristicPolynomial ...50 3. 3. 6. SpectralIndexes ...53 3. 4. AutocorrelationDescriptors ...

Limp materials are used in many economically impo~tant industries such as garment manufacture, shoe manufacture, aerospace (composites) and automobiles (seats and trim). The use of sensors is essential for reliable robotic handling of these materials, which are often based on naturally occurring substances such as cotton and leather. The materials are limp and have non-homogeneous mechanical properties which are often impossible to predict accurately. The applications are very demanding for vision and tactile sensing and signal processing, adaptive control systems, planning and systems integration. This book comprises the collection of papers presented at the NATO Advanced Research Workshop on 'Sensory Robotics for the Handling of Limp Materials', held in October 1988 at II Ciocco, Tuscany, Italy. The aim of the workshop was to examine the state of the art and determine what research is needed to provide the theoretical and technological tools for the successful application of sensory robotics to the handling of limp materials. The meeting also acted as the first-ever forum for the interchange of knowledge between applications-driven researchers and those researching into the provision of fundamental tools. The participants were drawn from academia (20), industry (5), and other non-university research organisations (5).

This collection sets out the results of various investigations into the chemical properties of refractory compounds and refractory-base alloys used in various fields of modern technology, together with original methods of analysis. The book is intended for analytical chemists, engineers, workers in scientific-research establishments and industrial laboratories, graduates, and students of the senior courses in chemical and metallurgical higher-education institutions. v CONTENTS Interaction of the Carbides of Group IV and V Transition Metals with Various Acids E. E. Kotlyar and T. N. Nazarchuk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Method of Quantitative X-ray Analysis for Determining the Amount of Free Carbon in Boron Carbide M. I. Sokhor and G. V. Sofronov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Method of Separating and Determining the Free Carbon in Materials Containing Refractory Compounds L. A. Mashkovich and A. F. Kuteinikov . . . . . . . . . . . . . . . . . . . . . . . . . . . " 14 Stability of Boron-Carbon Compounds in Oxygen at High Temperatures L. E. Pechentkovskaya and T. N. Nazarchuk . . . . . . . . . . . . . . . . . . . . 20 Certain Chemical Properties of Boron Carbonitride L. E. Pechentkovskaya and T. N. Nazarchuk . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Oxidation of Boron, Gallium, and Indium Phosphides in Air L. L. Vereikina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 High-Temperature Oxidation Resistance of Refractory Silicon Nitride-Silicon Carbide Materials I. N. Godovannaya and O. I. Popova . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 33 Production and Chemical Stability of the Hydrides of Group IV and V Transition Metals M. M. Antonova . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Chemical Analysis of the Reaction Products of Boron with Arsenic and Phosphorus A. A. Reshchikova and Z. S. Medvedeva . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Complexonometric Analysis of Molybdenum Alloys L. N. Kugai, O. F. Galadzhii, and V. I.

Boron has all the best tunes. That may well be the first impression of the Group 13 elements. The chemical literature fosters the impression not only in the primary journals, but also in asteady outflowofbooks focussing more or less closely on boron and its compounds. The same preoccupation with boron is apparent in the coverage received by the Group 13 elements in the comprehensive and regularly updated volume of the Gmelin Handbook. Yet such an imbalance cannot be explained by any inherent lack ofvariety, interest or consequence in the 'heavier elements. Aluminium is the most abundant metal in the earth's crust; in the industrialised world the metal is second only to iron in its usage, and its compounds can justifiably be said to touch our lives daily - to the potential detriment of those and other lives, some would argue. From being chemical curios, gallium and indium have now gained considerably prominence as sources of compound semiconductors like gallium arsenide and indium antimonide. Nor is there any want ofincident in the chemistriesofthe heavier Group 13 elements. In their redox, coordination and structural properties, there is to be found music indeed, notable not always for its harmony but invariably for its richness and variety. Thisbook seeks to redress the balance with a definitive, wide-rangingand up-to-date review of the chemistry of the Group 13 metals aluminium, gallium, indium and thallium.

There are two motives for studying materials processing in centrifuges. First, such research improves our understanding of the influence of acceleration and convection on materials processing. Second, there are commercial opportunities for production of unique and improved materials that cannot be prepared under normal earth conditions or in space. Through a combination of experiments and theory, we are gaining an understanding of centrifugation on phenomena of importance to materials processing. We find that it is necessary to consider not only acceleration, but also the Corio lis effect and the variation of acceleration with position. As one consequence, the vigor of buoyancy-driven convection is sometimes increased by centrifugation and sometimes decreased. Similarly, the tendency of the convection to become unstable or oscillatory may either be increased or decreased by centrifugation. On the other hand, the observed effects of centrifugation on product quality have largely gone unexplained. This volume constitutes the proceedings of The Second International Workshop on Materials Processing at High Gravity, hosted by Clarkson University in June of 1993. The concept for a workshop on materials processing in centrifuges was born at a series of informal meetings held in Paris in 1990. The First International Workshop on Materials Processing at High Gravity was held in May of 1991 in Dubna, USSR, on the banks of the Volga River. The proceedings of this workshop was published in 1992 as a special issue of the Journal of Crystal Growth.

This book is devoted to a nontraditional class of materials which are manufactured by the melt-blowing process. The text examines the structure and main properties of melt-blown materials as conditioned by peculiarities of overheated polymer melt spraying in oxidizing medium. Information is given about filtering mechanisms and the main types of polymer fibrous filtering materials.

From 5 to 15 August 1984, a group of 79 physicists from 61 laboratories in 26 countries met in Erice for the 22nd Course of the International School of Subnuclear Physics. The countries represented were Austria, Belgium, Brazil, Bulgaria, Canada, People's Republic of China, Denmark, the Federal Republic of Germany, France, Greece, Hungary, Iran, Israel, Italy, Japan, Korea, Malaysia, Mexico, the Netherlands, Pakistan, Poland, Sweden, Switzerland, Turkey, the United Kingdom, the United States of America. The School was sponsored by the Italian Ministry of Public Education (MPI), the Italian Ministry of Scientific and Technologi cal Research (MRST), the Regional Sicilian Government (ERS), and the Weizmann Institute of Science. The programme of the School was devoted to a review of the most significant results in theoretical and experimental research work on the interactions between what we believe today are the point like constituents of the world: quarks and leptons. It should however not be forgotten that many problems are still to be understood: especially in the forefront of the correla tion between quarks and leptons. This game started in 1966 with the proposal for "leptonic quarks" and went on with "preons" and "rishons" just to quote the most famous attempts to unify these two worlds."

The Army Materials and Mechanics Research Center has conducted the Saga more Army Materials Research Conferences, in cooperation with the Metallurgi cal Research Laboratories of the Department of Chemical Engineering and Metallurgy of Syracuse University, since 1954. The purpose of the conferences has been to gather together scientists and engineers from academic institutions, industry, and government who are uniquely qualified to explore in depth a sub ject of importance to the Army, the Department of Defense and the scientific community. Grain size and its control is a major factor governing the behavior of materi als. Knowledge that one can obtain grain sizes in the 10 micron down to sub micron range has established the basis for a new technology. This volume, Ultrafine-Grain Ceramics, addresses itself to the broad areas of: realization of fine-grain ceramics; preparation of ultrafine particle size materials; characterization of ultrafine particles and ultrafine-grain ceramics; processing and behavior of ultra fine-grain ceramics. The technical advice provided by Dr. S. K. Dutta of the Army Materials and Mechanics Research Center during the editing of this book is acknowledged. The continued active interest and support of these conferences by Dr. E. Scala, Director, Lt. Col. Joseph B. Mason, Commanding Officer, and J. F. Sullivan, Deputy Technical Director, of the Army Materials and Mechanics Re search Center is appreciated.

Adhesives in general and structural adhesives in particular are the subjects of much academic interest as well as commercial importance. Structural bonding, as a method of joining, offers a number of advantages over mechanical fastening. However, in order to achieve satisfactory results, the proper adhesive must be selected and the appropriate bonding procedures followed. The purpose of Structural Adhesives: Chemistry and Technology is to review the major classes of structural adhesives and the principles of adhesion and bonding as these relate to structural joints. Each chapter provides an overview of the topic under discussion with a list of references to the relevant literature. In addition to describing the chemistry involved, other aspects of structural adhesive technology are covered, such as formula tion, testing, and end uses. Some structural adhesives, especially epoxies and phenolics, have a long history of successful use and are now widely employed. Others, such as the structural acrylics and cyanoacrylates, are beginning to gain industrial acceptance. Urethanes and anaerobics have limited but important uses, while high-temperature adhesives are still largely in the research and development stage."

More than 30 years after the discovery of transition metals and organometal lics as catalysts for olefin polymerization these catalysts did not have lost their fascination. Since 1953 when Karl Ziegler has discovered the catalytic polymerization of ethylene leading to plastically formable polymers which are mechanically stable up to temperatures of about 100 DegreesC, synthetic polymers and rubbers have made their way right into private houses. This discovery has been a main impetus for the fast growing production of plastics. The stereoselective poly merization of propylene and other long-chain a-olefins first detected by Giulio Natta leads to an even broadened field of applications. Another enforcing factor were the developments of Standard Oil of Indiana and Phillipps Petroleum Company who engaged in the polymerization of a-olefins supported molybdenum, cobalt and later on chromium catalysts which clearly indicates the wide variety of suitable systems. This kind of research acknowledged merit when in 1963 the Nobel prize of chemistry was awarded to Ziegler and Natta. Although to a great extent there is a technical application for these catalysts, up to now the nature of the active centres and many reaction mechanisms are not completely known.

In The New Superconductors, Frank J. Owens and Charles P. Poole, Jr., offer a descriptive, non-mathematical presentation of the latest superconductors and their properties for the non-specialist. Highlights of this up-to-date text include chapters on superfluidity, the latest copper oxide types, fullerenes, and prospects for future research. The book also features many examples of commercial applications; an extensive glossary that defines superconductivity terms in clear language; and a supplementary list of readings for the interested lay reader.