Asphaltenes have traditionally been viewed as being extremely complex, thus very hard to characterize. In addition, certain fundamental properties of asphaltenes have pre viously been inaccessible to study by traditional macroscopic methods, further limiting understanding of asphaltenes. These limitations inhibited development of descriptions regarding the microscopic structure and solution dynamics of asphaltenes. However, a variety ofmore recent studies have implied that asphaltenes share many chemical properties with the smaller, more tractable components of crude oils. Recent measurements have indicated that asphaltene molecular weights are not as arge as previously thought, perhaps in the range of 600 to I 000 amu. In addition, new experimental methods applied to asphaltene chemical structures have been quite revealing, yielding a broad understanding. Conse quently, the ability to relate chemical structure with physical and chemical properties can be developed and extended to the understanding of important commercial properties of asphal tenes. This book treats significant new developments in the fundamentals and applications of asphaltenes. In the first section ofthe book, new experimental methods are described that characterize asphaltene structures from the molecular to colloidallength scale. The colloidal properties are understandable in terms of asphaltene chemical structures, especially with regard to the heteroatom impact on bonding. However, quantitative measurements of the of asphaltene self-association still need to be determined. In the second section of enthalpy this book, the fundamental understanding of asphaltenes is related riirectly to asphaltene utilization."

During recent years a high level of interest has been maintained in the kinetics and mechanisms of inorganic compounds in solution, and there has also been a notable upsurge of literature concerned with reaction mechanisms of organo transition metal compounds. The reviews of the primary literature previously provided by "Inorganic Reaction Mechanisms" (Royal Society of Chemistry) and "Reaction Mechanisms in Inorganic Chemistry" in "MTP International Re views of Science" (Butterworths) continue to be of considerable value to those concerned with mechanistic studies, and it is unfortunate they are no longer published. The objective of the present series is to provide a continuing critical review of literature dealing with mechanisms of inorganic and organometallic reactions in solution. The scope of potentially relevant work is very large, particularly in the field of organotransition metal chemistry, and papers for inclusion have been chosen that specifically probe mechanistic aspects, rather than those of a prep arative nature. This volume covers the literature published during the period July 1979 to December 1980 inclusive. Material is arranged basically by type of reaction and type of compound along generally accepted lines. Numerical data are usually reported in the units used by the original authors, though the units of some results have been converted in order to make comparisons.

This book arose from a symposium titled 'Transition Metal Carbides and Nitrides: Preparation, Properties, and Reactivity' organized by Jae Sung Lee, Masatoshi Nagai and myself. The symposium was part of the 1995 Congress of Pacific Rim Chemical Societies, held in Honolulu, Hawaii between December 17-22, 1995. The meeting was the first major conference to exclusively address the theme of metal carbides and nitrides, and brought together many of the major researchers in the field. Over 50 scientists and engineers reported their latest findings in five sessions of presentations and discussions. The book closely follows the topics covered in the conference: Theory of bonding Structure and composition Catalytic properties Physical properties New methods of preparation Spectroscopy and microscopy The book is unique in its coverage. It provides a general introduction to the properties and nature of the materials, but also covers their latest applications in a wide variety of fields. It should thus be of interest to both experts and nonexperts in the fields of material science, solid-state chemistry, physics, ceramics engineering, and catalysis. The first chapter gives an overview, and many of the chapters provide summaries of advanced topics. All contributions were peer-reviewed.

Microcharacterization of materials is a rapidly advancing field. Among the many electron and ion probe techniques, the cathodoluminescence mode of an electron probe instrument has reached a certain maturity, which is reflected by an increas ing number of publications in this field. The rapid rate of progress in applications of cathodoluminescence techniques in characterizing inorganic solids has been especially noticeable in recent years. The main purpose of the book is to outline the applications of cath odoluminescence techniques in the assessment of optical and electronic proper ties of inorganic solids, such as semiconductors, phosphors, ceramics, and min erals. The assessment provides, for example, information on impurity levels derived from cathodoluminescence spectroscopy, analysis of dopant concentra tions at a level that, in some cases, is several orders of magnitude lower than that attainable by x-ray microanalysis, the mapping of defects, and the determination of carrier lifetimes and the charge carrier capture cross sections of impurities. In order to make the book self-contained, some basic concepts of solid-state phys ics, as well as various cathodoluminescence techniques and the processes leading to luminescence phenomena in inorganic solids, are also described. We hope that this book will be useful to both scientists and graduate students interested in microcharacterization of inorganic solids. This book, however, was not intended as a definitive account of cathodoluminescence analysis of in organic solids. In considering the results presented here, readers should re member that many materials have properties that vary widely as a function of preparation conditions."

This and its companion Volume 2 chronicle the proceedings of the First Technical Conference on Polyimides: Synthesis, Char acterization and Applications held under the auspices of the Mid Hudson Section of the Society of Plastics Engineers at Ellenville, New York, November 10-12, 1982. In the last decade or so there has been an accelerated interest in the use of polyimides for a variety of applications in a number of widely differing technologies. The applications of polyimides range from aerospace to microelectronics to medical field, and this is attributed to the fact that polyimides offer certain desirable traits, inter alia, high temperature stability. Polyimides are used as organic insulators, as adhesives, as coat ings, in composites, just to name a few of their uses. Even a casual search of the literature will underscore the importance of this class of materials and the high tempo of R&D activity taking place in the area of polyimides. So it was deemed that a conference on polyimides was both timely and needed. This conference was designed to provide a forum for discussion of various ramifications of polyimides, to bring together scientists and technologists interested in all aspects of polyimides and thus to provide an opportunity for cross-pollination of ideas, and to highlight areas which needed further and intensi fied R&D efforts. If the comments from the attendees are a baro meter of the success of a conference, then this event was highly successful and fulfilled amply its stated objectives.

Cryogenics is an emerging technology filled with promises. Many cryogenic systems demand the use of nonmetallics and composites for adequate or increased performance. Thermal and electrical insulations, potting for superconducting magnets' mechanical sta bility, and composite structures appear to be some of the most significant applications. Research on nonmetallics at cryogenic temperatures has not progressed to the degree of research on metals. Nor can room temperature research be extrapolated to low tempera tures; most polymers undergo a phase transformation to the glassy state below room temperature. Research by producers, for the most part, has not been prac tical, because, except for LNG applications, the market for large material sales is not imminent. There are, however, many government stimulated developmental programs. Research on nonmetallics thus is dictated by development project needs, which require studies orien ted toward prototype hardware and specific objectives. As a result, research continuity suffers. Under these conditions, periodic topical conferences on this subject are needed. Industry and uni versity studies must be encouraged. Designers and project research material specialists need to exchange experiences and data. Low temperature-oriented research groups, such as the National Bureau of Standards and the Institute for Technical Physics - Karlsruhe, must contribute by assisting with fundamentals, interpreting proj ect data, and contributing to project programs through their materials research."

General The making and breaking of carbon-metal bonds is fundamental to all the p- cesses of organometallic chemistry and moreover plays a significant role in - mogeneous as well as heterogeneous catalysis. This rather blunt statement - phasises the extent to which a proper understanding of the structure, energetics and reactivity of C-M bonds is at the core of the discipline. In order to accept it, a proper definition of the terms involved is required. Quite simply we define the metal-carbon bond in its broadest sense to embrace carbon linked to transiti- metals, lanthanides and actinides, and main group metals. We do not dist- guish between formally covalent single or multiple bonding on the one hand and q-bonding on the other. In the studies to be described in the following chapters, the emphasis will be on transition metal complexes and insofar as the fun- mentals come under scrutiny, simple metal alkyls or related species (metal al- nyl, alkynyl, aryl, or allyl) will play an emphatic part. The central role of metal alkyls and their congeners and especially the role of their metal carbon linkage in homogeneous catalysis may be appreciated by considering some key reaction steps leading to their formation or breakdown. There follows a few prominent examples of transition metal mediated stoichiometric or catalytic processes: - In homogeneous hydrogenation of double bonds, the stepwise reaction of an q2-coordinated alkene with dihydrogen gives first an alkyl metal hydride, and then the decoordinated alkane by elimination.

Syracuse University and the Army Materials and Mechanics Research Center of Watertown, Massachusetts have conducted the Sagamore Army Materials Research Conference since 1954. In ce1ebration of the 25th Anniversary of this conference, these proceedings are dedicated to the founding members of the Sagamore Conferences. They are Prof. Dr. George Sachs, Dr. James L. Martin, Colonel Benjamin S. Mesik, Dr. Reinier Beeuwkes, Mr. Norman L. Reed and Dr. J. D. Lubahn. This vo1ume, ADVANCES IN METAL PROCESSING, addresses Rapid Solidification Processing, Powder Processing and Conso1idation, We1ding and Joining, Thermal and. Mechanica1 Processing, Meta1 Removal and Process Mode1ing. The dedicated assistance of Mr. Joseph M. Bernier of the Army Materials and Mechanics Research Center and He1en Brown DeMascio of Syracuse University throughout the stages of the conference p1anning and fina11y the pub1ication of this book is deep1y appreciated. Syracuse University Syracuse, New York The Editors vii CONTENTS OVERVIEW Materials Processing - A Perspective of the Field 1 M.C. Flemings and R. Mehrabian SESSION I RAPID SOLIDIFICATION PROCESSING B.B. Rath, Moderator Heat Flow Limitations in Rapid Solidification Processing . . . . . . . . . . . 13 R. Mehrabian, S.C. Hsu, C.G. Levi, and S. Kou Laser Processing of Materials . . . . . 45 B.H. Kear, E.M. Breinan, and E.R. Thompson Electrohydrodynamic Techniques in Metals 79 Processing . . . . . . . . . . ."

"Relativistic Methods for Chemists," written by a highly qualified team of authors, is targeted at both experimentalists and theoreticians interested in the area of relativistic effects in atomic and molecular systems and processes and in their consequences for the interpretation of the heavy element's chemistry.

The theoretical part of the book focuses on the relativistic methods for molecular calculations discussing relativistic two-component theory, density functional theory, pseudopotentials and correlations. The experimentally oriented chapters describe the use of relativistic methods in different applications focusing on the design of new materials based on heavy element compounds, the role of the spin-orbit coupling in photochemistry and photobiology, and chirality and its relations to relativistic description of matter and radiation.

This book is written at an intermediate level in order to appeal to a broader audience than just experts working in the field of relativistic theory.

Combined oxygen, in the form of water, metal oxides, silicates and other oxyions, accounts for about 50% by weight of the earth's crust. The chemistry of this most abundant element has two major aspects: that of water and aqueous solutions of electrolytes, and that of the solid state. The methodology and techniques appropriate for the study of these fields are sufficiently different that there have been very few points of contact between solution- and solid state chemists. One such contact, of great potential value, is provided by the extensive class of polyoxoanions formed by the transition metals of groups 5 and 6. As 'heteropoly and isopoly acids' these polyanions have been known and investigated for more than a century. The pre sent book is an attempt to survey the chemistry, structures, and applications of these species. Although the book forms part of a series in inorganic chemistry, the field of polyoxometalates deserves wider attention, for example, from organic chemists, especially those concerned with homogeneous and heterogeneous catalysis, and from biochemists, solid state- and materials scientists."

After the success of the previous summer schools organized by the Nuclear Physics Division of the Netherlands' Physical Society in 1975 and 1977, we thought it worthwhile to continue this tradition. The immediate very positive reactions received from all invited speakers encouraged us to proceed with the orgaization. Although the number of students had to be restricted to about one hundred, the international character of the School was evident from about thirty nationalities which were represented. The material contained in this book covers the talks given by all speakers invited to lecture on the subject of nuclear structure research. These proceedings should therefore serve as an excellent introduction to many topics of current interest in this exciting field. We hope that the lectures and discussions as well as the many informal contacts made during the various social activities will greatly stimulate interest in nuclear structure investigations among all the participants. The organization of the summer school has been made possible by substantial support given by the Scientific Affairs Division of the North Atlantic Treaty Organization, the Netherlands' Ministry of Education and Science and the Netherlands' Physical Society. The invaluable help of the "Bureau Congressen" of the Ministry of Education and Science and the friendly assistance of the manage ment of the College of Agriculture in Dronten contributed greatly to the pleasant atmosphere during the summer school."

In the decade since the introduction of the first commercial lithium-ion battery research and development on virtually every aspect of the chemistry and engineering of these systems has proceeded at unprecedented levels. This book is a snapshot of the state-of-the-art and where the work is going in the near future. The book is intended not only for researchers, but also for engineers and users of lithium-ion batteries which are found in virtually every type of portable electronic product.

Phthalocyanines exhibit intriguing physic-chemical properties that render them important as a class of molecular functional materials. In addition to their tra- tional industrial applications as dyes and pigments, more recently their use as the organic semiconductors,photodynamictherapy medicines, non-linear optical ma- rials, catalysts for the photo oxidation, optical recording materials, and gas sensors attracts great research interests in these tetrapyrrole species. As manifested by the rapidly increasing number of related scienti?c publications in recent years, great progress has been made in the ?eld of advanced phthalocyaninematerials. Tremendous efforts have been paid toward the development of new phtha- cyanine molecular materials as well as toward their applications. Recent emphasis in both academic researches and technical ?eld has been put on the design and synthesis of novel phthalocyanine species, the structure-propertyrelationship, se- assembly properties, molecular electronics and opto-electronics, and dye-sensitized solarcells.Althoughexcellentreviewsandmonographsaboutphthalocyanineswere publishedseveralyearsago,it is time to providea surveyof a numberof newimp- tant developments in this fascinating area of phthalocyanine chemistry. The aim of this book is to bring both the academic and industrial researchers an easy way to the new progress of phthalocyanines made lately in related ?eld.

The present volume of this series, following the tradition of the previous volumes, covers three major lines of research on crystallization: growth from vapor and epitaxy, growth from solution, and growth from melt. As in the previous volumes, preference is given to papers that provide original results and reviews of results obtained by the authors and those from published sources, although some of the papers are either purely original or purely of review character. The first section deals with crystal growth from vapor and epitaxy and contains three papers. One of them, on artificial epitaxy, discusses and reviews published results from the last three years in this rapidly developing area. The results are used in outlining mechanisms for oriented film growth on amorphous substrates. Another paper in this section deals with classical epitaxy, namely oriented growth on single-crystal substrates, where some important conclusions are drawn from the growth of gallium nitride films on sapphire, which concern the orientation relationships in that pair of substances. The last paper in the section deals with film growth under ion bombardment (the corresponding techniques in film crystallization have already advanced from theory to practical applications).

This was the third meeting in the series of special topical conferences on Non-Metallic materials at low temperatures. The first meeting was in Munich in 1978, the second in Geneva (1980) and so Heidelberg 1984 seemed an obvious time to review some of the hopes and objectives of the earlier meetings. It is also appropriate to consider the changing needs of the cryogenic community and how best the theory and practice of Non-metallic materials can be applied to suit this dynamic young science. The aims and objectives of the International Cryogenic Materials Board in sponsoring this meeting remain the same. Namely, to provide a forum where practicing Engineers can meet with materials suppliers and researchers in an attempt to ensure that a real understanding exists between the two sides of the Cryogenic Materials Community. In this atmosphere, real problems can be addressed together with full discussions of tried and tested practical solutions. It is in this way that knowledge and confidence may grow hand in hand with the logical growth of the industry.

Primarily, the aim of this book is to provide a reference work for senior students and research workers engaged in the synthetic aspects of chemistry. The various classes of compounds under discussion provide useful interme diates for the synthesis of numerous nitrogen-containing derivatives. Imidoyl halides are also intermediates in several classical name reactions, such as the Gattermann, Houben-Hoesch, and Vilsmeier-Haack syntheses of aldehydes and ketones, the Beckmann rearrangement, and the v. Braun degradation. Some imidoyl halides have shown interesting agricultural activities, and the generation of highly reactive species (ketenimines, nitrile oxides, nitrile imides, carbodiimides, etc.) from imidoyl halides has contributed to the study of polar cycloaddition reactions. To enable researchers to utilize this chemistry without consulting the original references, I have included a number of selected working examples. This procedure will facilitate the transformation of written information into well designed experiments, especially since part of the cited literature is not readily available. The book is organized around classes of imidoyl halides, with synthesis and chemistry discussed in an orderly fashion. The physical properties of the known imidoyl halides are listed in tables, and I have attempted to draw attention to the more recent literature. The one or two references provided for each compound represent those which best describe its physical constants and synthesis.

This book is intended to provide a fundamental basis for the study of the interaction of polymers with living systems, biochemicals, and with aqueous solutions. The surface chemistry and physics of polymeric materials is a subject not normally covered to any significant extent in classical surface chemistry textbooks. Many of the assumptions of classical surface chemistry are invalid when applied to polymer surfaces. Surface properties of polymers are important in the development of medical devices and diagnostic products. Surface properties are also of vital importance in fields such as adhesion, paints and coatings, polymer-filler interactions, heterogeneous catalysis, composites, and polymers for energy generation. The book begins with a chapter considering the current sources of information on polymer surface chemistry and physics. It moves on to consider the question of the dynamics of polymer surfaces and the implica tions of polymer surface dynamics on all subsequent characterization and interfacial studies. Two chapters are directed toward the question of model polymers for preparing model surfaces and interfaces. Complete treatments of X-ray photoelectron spectroscopy and attenuated total reflection infrared spectroscopy are given. There is a detailed treatment of the contact angle with particular emphasis on contact angle hysteresis in aqueous systems, followed by chapters on interfacial electrochemistry and interface acid-base charge-transfer properties. The very difficult problem of block and graft copolymer surfaces is also discussed. The problem of theoretical calculations of surface and interfacial tensions is presented. Raman spectroscopy is considered as an analytical technique for polymer surface characterization."

Since the early 1930's, Soviet chemists have played a lead ing role in the study of unfamiliar oxidation state compounds of the peroxide, superoxide, and ozonide types. Interest in the alkali and alkaline earth metal derivatives is now widespread and diverse, and numerous practical applications of these com pounds have evolved, ranging from their use as air revitaliza tion materials in space cabins to their use in compounding semiconductor materials. Professor Vol'nov is eminently qualified to write this monograph since for many years he has been a leading investi gator and prolific writer in the field of peroxide, superoxide, and ozonide chemistry. He has succeeded in presenting a lucid and detailed discussion of past work, the present state, and the future potential of this area of unfamiliar oxidation state chemistry. Of particular interest is Professor Vol 'nov's extensive compilation of available thermodynamic, kinetic, and structural data for the alkali and alkaline earth peroxides, superoxides, and ozonides. In addition, he has reviewed the known methods of synthesis, as well as the practical applications for which these compounds are suited. This monograph will be of interest and value to chemists, not only for the information it imparts, but equally for the information it does not impart, thereby illuminating the re search paths and investigation which must be undertaken in order to increase our knowledge concerning the chemistry of this important class of chemical compounds."

In recent years many research workers have turned their attention to the quantitative characterization of complex compounds and reactions of complex-formation in solution. Instability constants characterize quantitatively the equili bria in solutions of complex compounds and are extensively used by chemists of widely-varying specialities, in analytical chemistry, electrochemistry, the technology of non-ferrous and rare metals, etc., for calculations of various kinds. Despite the wealth of numerical data, no reasonably full coliection of instability constants of complex compounds has been made until now. The various individual collections of data are far from complete and in most cases omit references to the source materials. Moreover, the present state of the chemistry of complex compounds most urgently demands the complete systematization of data on instability constants and an extension of work in this field which would take advantage of the latest physico-chemical methods. The present work contains instability constants for 1,381 complex compounds. We have considered it convenient to preface the summary of the instability constants with an introductory section of a general theoretical character. This section deals with methods for the calculation of instability constants from experimental data, the influence of external conditions, such as temperature and ionic strength, on the stability of com plexes, and the principal factors determining the stability of complex compounds in aqueous solution. (vii) PREFACE In compiling the summary we have used the original litera ture and abstracts for the most part up to 1954, and some work published in 1955-1956."

Phosphorus is essential to all life. A critical component of fertilizers, Phosphorus currently has no known substitute in agriculture. Without it, crops cannot grow. With too much of it, waterways are polluted. Across the globe, social, political, and economic pressures are influencing the biogeochemical cycle of phosphorus. A better understanding of this non-renewable resource and its impacts on the environment is critical to conserving our global supply and increasing agricultural productivity. Most of the phosphorus-focused discussion within the academic community is highly fragmented. Phosphorus, Food, and Our Future will bring together the necessary multi-disciplinary perspectives to build a cohesive knowledge base of phosphorus sustainability. The book is a direct continuation of processes associated with the first international conference on sustainable phosphorus held in the United States, the Frontiers in Life Sciences: Sustainable Phosphorus Summit, though it is not a book of conference proceedings; rather, the book is part of an integrated, coordinated process that builds on the momentum of the Summit. The first chapter will introduce the biological and chemical necessity of phosphorus. The subsequent ten chapters will explore different facets of phosphorus sustainability and the role of policy on future global phosphorus supplies. The final chapter will synthesize all of the emerging views contained in the book, drawing out the leading dilemmas and opportunities for phosphorus sustainability.

For almost a quarter of a century the words "nuclear magnetic reso nance" were synonymous with proton I, leasurements. During this period the literature abounded with a seemingly infinite variety of 1H NHR studies concerned primarily with carbon chemistry. Occasionally a "novel" nucleus was studied and, even in those early days, the poten- 13 14 31 19 tial offered by C, N, P and F was clearly recognized. Despite the allure, the technical difficulties involved in measuring some of these nuclei were far from trivial. Small magnetic moments and low natural abundance in combination with spin-spin coupling from other nuclei, mostly protons, resulted in a signal-to-noise problem whose severity effectively excluded the study of metal complexes with unfa vorable solubility characteristics. The first important breakthrough came with the advent of broad band 1H-decoupling. For example, the featureless broad 31p resonance associated with the commonly used ligand triphenyl phosphine is converted to a sharp, more readily ob served singlet when wide-band decoupling is employed (see Fig. 1). Despite this improvement investigation of more interesting molecules, such as catalytically active complexes was forced to await the devel opment of Fourier Transform methods since only with relatively rapid signal averaging methods could sufficient signal-to-noise ratios be achieved."

As natural minerals, silica and silicates constitute by far the largest part of the earth's crust and mantle. They are equally important as raw materials and as mass produced items. For this reason they have been the subject of scientific research by geoscientists as well as by applied scientists in cement, ceramic, glass, and other industries. Moreover, intensive fun damental research on silicates has been carried out for many years because silicates are, due to their enormous variability, ideally suited for the study of general chemical and crystallographic principles. Several excellent books on mineralogy and cement, ceramics, glass, etc. give brief, usually descriptive synopses of the structure of silicates, but do not contain detailed discussions of their structural chemistry. A number of monographs on special groups of silicates, such as the micas and clay min erals, amphiboles, feldspars, and zeolites have been published which con tain more crystal chemical information. However, no modern text has been published which is devoted to the structural chemistry of silicates as a whole. Within the last 2 decades experimental and theoretical methods have been so much improved to the extent that not only have a large number of silicate structures been accurately determined, but also a better under standing has been obtained of the correlation between the chemical composition of a silicate and its structure. Therefore, the time has been reached when a modern review of the structural chemistry of silicates has become necessary."

In recent years several improvements have been made in the manufacturing of resistive, superconducting and hybrid mag nets. Condensed matter physicists are nowadays doing ex periments in steady magnetic fields of up to 30 Tesla. But the field homogenity {/B}, required in a volume of the order of a 3 few cm is usually several orders of magnitude less severe than the one which is needed for high resolution NMR. Over the last 30 years, with each generation of new high resolution NMR spectrometers, from 100 MHz up to 600 MHz, taking advan tage of the increase in sensitivity and resolution, new areas of research have been opened in chemistry, physical chemistry and biochemistry. The generation of the 20 Tesla supercon ducting magnets is coming. Thus one may seriously start to consider high resolution NMR at 1 GHz. The purpose of this volume is to examine some of the advantages which can be obtained at such high frequencies and some of the problems we shall be facing. An important aspect of NMR at high field which is not presented in this volume concerns the design of the magnet. The building of a superconducting magnet, producing a field 10 3 higher than 20 T, with a field homogeneity IlB/B 10-, in a cm volume still remains today in 1990 a major challenge. Grenoble, France J. B. Robert Guest-Editor Professor J. B. Robert Service National des Champs Intenses B. P."