The last decade or so has seen a dramatic increase in the amount of detailed structural information available from a range of experimental techniques. Exciting new techniques such as atomic force microscopy have become widely available, while the potential of established methods like X-ray diffraction and electron microscopy has been greatly enhanced by powerful new sources and analytical methods. Progress in computing has also had a widespread impact: in areas such as neutron scattering, large data sets can now be manipulated more readily. The software supplied with commercial instruments generally provides more sophisti cated analytical facilities, while time-resolved X-ray studies rely on rapid data handling capabilities. The polymer scientist is faced with an expanding array of experimental tools for addressing both fundamental science and industrial problems. This work reviews some recent developments in structural techniques, with the aim of presenting the current 'state of the art' in a selection of areas."

Countless pages have been written on alternative energy sources since the fall of 1973 when our dependence on fossil petroleum resources became a grim reality. One such alternative is the use of biomass for producing energy and liquid and gaseous fuels. The term "biomass" generally refers to renewable organic matter generated by plants through photosynthesis. Thus trees, agri cultural crops, and aquatic plants are prime sources of biomass. Furthermore, as these sources of biomass are harvested and processed into commercial prod ucts, residues and wastes are generated. These, together with municipal solid wastes, not only add to the total organic raw material base that can be utilized for energy purposes but they also need to be removed for environmental reasons. Biomass has been used since antiquity for energy and material needs. In is still one of the most sought-after energy sources in most of the fact, firewood world. Furthermore, wood was still a dominant energy source in the U. S. only a hundred years ago (equal with coal). Currently, biomass contributes about 15 2 quadrillion Btu (l quad = 10 Btu) of energy to our total energy consump tion of about 78 quad. Two quad may not seem large when compared to the contribution made by petroleum (38 quad) or natural gas (20 quad), but bio mass is nearly comparable to nuclear energy (2. 7 quad).

The Progress in Medical Radiation Physics series presents in-depth reviews of many of the significant developments resulting from the application of physics to medicine. This series is intended to span the gap between research papers published in scientific journals, which tend to lack details, and complete textbooks or theses, which are usually far more detailed than necessary to provide a working knowledge of the subject. Each chapter in this series is designed to provide just enough information to enable readers to both fully understand the development described and apply the technique or concept, if they so desire. Thorough references are provided for those who wish to consider the original literature. In this way, it is hoped that the Progress in Medical Radiation Physics series will be a catalyst encouraging medical physicists to apply new techniques and developments in their daily practice. Colin G. Orton ix Contents 1-1. The Tracking Cobalt Project: From Moving-Beam Therapy to Three-Dimensional Programmed Irradiation W. A. Jennings 1. Introduction 2. Establishing Moving-Beam Techniques at the Royal Northern Hospital, 1945-1955 4 2.1. Alternative Moving-Beam Techniques 4 2.2.

The physics of atomic inner shells has undergone significant advances in recent years. Fast computers and new experimental tools, notably syn chrotron-radiation sources and heavy-ion accelerators, have greatly enhan ced the scope of problems that are accessible. The level of research activity is growing substantially; added incentives are provided by the importance of inner-shell processes in such diverse areas as plasma studies, astrophysics, laser technology, biology, medicine, and materials science. The main reason for all this exciting activity in atomic inner-shell physics, to be sure, lies in the significance of the fundamental problems that are coming within grasp. The large energies of many inner-shell processes cause relativistic and quantum-electrodynamic effects to become strong. Unique opportunities exist for delicate tests of such phenomena as the screening of the electron self-energy and the limits of validity of the present form of the frequency-dependent Breit interaction, to name but two. The many-body problem, which pervades virtually all of physics, presents somewhat less intractable aspects in the atomic inner-shell regime: correlations are relatively weak so that they can be treated perturbatively, and the basic potential is simple and known The dynamics of inner-shell processes are characterized by exceedingly short lifetimes and high transition rates that strain perturbation theory to its limits and obliterate the traditional separation of excitation and deexcitation. These factors are only now being explored, as are interference phenomena between the various channels."

This book is intended for scientists, researchers, and graduate students interested in solutions in general, and solutions of metals in particular. Readers are assumed to have a good background in thermodynamics, presented in such books as those cited at the end of Chapter 1, "Thermo dynamic Background." The contents of the book are limited to the solutions of metals + metals, and metals + metalloids, but the results are also appli cable to numerous other types of solutions encountered by metallurgists, materials scientists, geologists, ceramists, and chemists. Attempts have been made to cover each topic in depth with numerical examples whenever necessary. Chapter 2 presents phase equilibria and phase diagrams as related to the thermodynamics of solutions. The emphasis is on the binary diagrams since the ternary diagrams can be understood in terms of the binary diagrams coupled with the phase rule, and the Gibbs energies of mixing. The cal culation of thermodynamic properties from the phase diagrams is not emphasized because such a procedure generally yields mediocre results. Nevertheless, the reader can readily obtain thermodynamic data from phase diagrams by reversing the detailed process of calculation of phase diagrams from thermodynamic data. Empirical rules on phase stability are given in this chapter for a brief and clear understanding of the physical and atomistic factors underlying the alloy phase formation."

The building explosion during the years 1945-1960 will inevitably lead to increased demolition in the next decades since the lifetime distribution of structures no longer fulfills its functional social requirements in an acceptable way. In the building period mentioned there was a great increase in reinforced and prestressed concrete construction. Consequently there is now more and more concrete to be demolished. Increasingly severe demands will be made upon demolition technology, including the demand for human- and environment-friendly techniques. On the other hand, the possibility of disposing of debris by dumping is steadily diminishing, especially close to major cities and generally in countries with a high population density. At the same time in such countries and in such urban areas a shortage of aggregates for making concrete will develop as a result of restrictions on aggregate working because of its effect on the environment and because of the unavailability of aggregate deposits due to urban development. From the foregoing it follows that recycling and re-use of environment- and human-friendly demolished and fragmented building rubble should be considered. The translation of this general problem into terms of materials science is possible by forming clear ideas of adhesion and cohesion: the whole process of demolition, fragmentation, and recycling or re-use of concrete is to break the bonding forces between atoms and molecules and to form new bonds across the interfaces of various particles of either the same nature or a different nature.

Four years after a first meeting in BADDECK, Canada, on the Physics of Ion-Ion and Electron-Ion collisions, a second Nato Advanced Study Institute, in HAl~/Lesse, Belgium, reexamined the subject which had become almost a new one, in consideration of the many important developments that had occured in the mean time. The developments have been particularly impressive in two areas : the di-electronic recombination of electrons with ions and the collisional processes of mUltiply charged ions. For dielectronic recombination, a major event was the obtainment, in 1983, of the first experimental data. This provided, at last, a non speculative basis for the study of that intricate and subtle process and strongly stimulated the theoretical activities. Multiply charged ions, on the other hand, have become popular, thanks to the development of powerful ion sources. This circumstance, together with a pressing demand from thermonuclear research for ionisation and charge exchange cross sections, has triggered systematic experimental investigations and new theoretical studies, which have contributed to considerably enlarge, over the last five years, our understanding of the collisional processes of multiply charged ions. Dielectronic recombination and multiply charged ions were therefore central points in the programme of the A.S.I. in HAN/Lesse and are given a corresponding emphasis in the present book.

In the early 1980s capillary liquid chromatography was being established; it was a period in which only a few research groups published a relatively small number of papers on the subject. In terest has since taken off, and a period of intense development, to which no end is yet in sight, is now upon us. More investiga tors and instrument-making firms are now entering the field. This greater interest has resulted in the rapid appearance of two collec tions [1, 2] and a series of topical reviews [3-6]. However, it could hardly be said that all the problems in this area have been formulated, let alone solved. The preparation of very efficient - open tubular or packed - microbore columns, for example, remains more an art than a science, while the relation ship between radial and longitudinal mass transfer, and the effect of transcolumn velocity profiles on chromatographic efficiency, have been very poorly studied. Indeed, recent publications on these subjects have sometimes, far from clarifying matters, only muddied them further. Many instrument-making firms are trying to unify their equip ment so that it is suitable for microbore, conventional (analytical), and preparative liquid chromatography. This approach has not real ized the full potential of capillary chromatography, and there also remains room for improving the performance of capillary columns.

The content of this monograph stems from the writer's early involvement with the design of a series of television camera tubes: the orthicon, the image orthicon and the vidicon. These tubes and their variations, have, at different times been the "eyes" of the television system almost from its inception in 1939. It was natural, during the course of this work, to have a parallel interest in the human visual system as well as in the silver halide photographic process. The problem facing the television system was the same as that facing the human visual and the photographic systems, namely, to abstract the maximum amount of information out of a limited quantity oflight. The human eye and photographic film both repre sented advanced states of development and both surpassed, in their performance, the early efforts on television camera tubes. It was particularly true and "plain to see" that each improvement and refinement of the television camera only served to accentuate the remarkable design of the human eye. A succession of radical advances in camera-tube sensitivity found the eye still operating at levels of illumination too low for the television camera tube. It is only recently that the television camera tube has finally matched and even somewhat exceeded the performance of the human eye at low light levels. It was also clear throughout the work on television camera tubes that the final goal of any visual system-biological, chemical, or electronic-was the ability to detect or count individual photons."

The U. S. Army Materials Research Agency has conducted the Saga more Army Materials Research Conferences, in cooperation with the Metallurgical Research Laboratories of the Department of Chemical En gineering and Metallurgy of Syracuse University, since 1954. The pur pose of the conferences has been to gather together scientists and engi neers from academic institutions, industry, and government who are uniquely qualified to explore in depth a subject of importance to the Army and the Department of Defenseo The subject of the Thirteenth Sagamore Army Materials Research Con ference, "Surfaces and Interfaces I: Chemical and Physical Characteris tics," was chosen from a substantial number of possible topics because scientists in the Army responsible for materials research, the conference committee, and the participants believed that much good would result from a detailed analysis of: the knowledge and role of surfaces, including their fundamental characteristics; the role of adsorption and adhesion; and the kinetics, both of exterior surfaces and interfaces. This informa tion should aid immeasurably in leading the way to vastly improved mate rials, vitally essential if progress is to be made in structures having improved performance. The wisdom of selecting a topic concerned with surfaces and inter faces is substantiated by the papers presented in this publication."

This book is devoted to the deformation and failure in metallic materials, summarizing the results of a research programme financed by the "Deutsche Forschungsgemeinschaft." It presents the recent engineering as well as mathematical key aspects of this field for a broad community. Its main focus is on the constitutive behaviour as well as the damage and fracture of metallic materials, covering their mathematical foundation, modelling and numerics, but also relevant experiments and their verification.

The molecular mechanisms underlying the fact that a crystal can take a variety of external forms is something we have come to understand only in the last few decades. This is due to recent developments in theoretical and experimental investigations of crystal growth mechanisms.
Morphology of Crystals is divided into three separately available volumes. Part A contains chapters on roughening transition; equilibrium form; step pattern theory; modern PBC; and surface microtopography. This part provides essentially theoretical treatments of the problem, particularly the solid-liquid interface. Part B contains chapters on ultra-fine particles; minerals; transition from polyhedral to dendrite; theory of dendrite; and snow crystals. All chapters are written by world leaders in their respective areas, and some can be seen as representing the essence of a life's work. This is the first English-language work which covers all aspects of the morphology of crystals - a topic which has attracted top scientific minds for centuries. As such, it is indispensable for anyone seeking an answer to a question relating to this fascinating problem: mineralogists, petrologists, crystallographers, materials scientists, workers in solid-state physics and chemistry, etc.
In Parts A: Fundamentals and B: Fine Particles, Minerals and Snow equilibrium and kinetic properties of crystals are generally approached from an atomistic' point of view. In contrast, Part C: The Geometry of Crystal Growth follows the alternative and complementary geometrical' description, where bulk phases are considered as continuous media and their interfaces as mathematical surfaces with orientation-dependent properties. Equations of motion for a crystal surface are expressed in terms of vector and tensor operators working on surface free energy and growth rate, both expressed as functions of surface orientation and driving force, or affinity' for growth. This approach emphasizes the interrelation between equilibrium and kinetic behavior. Part 1 establishes the theoretical framework. Part 2 gives a construction toolbox for explicit (analytic) functions. An extra chapter is devoted to experimental techniques for measuring such functions: a new approach to sphere growth experiments. The emphasis throughout is on principles and new concepts.
Audience: Advanced readers familiar with traditional aspects of crystal growth theory. Can be used as the basis for an advanced course, provided supplementation is provided in the areas of atomistic models of the advancing surface, diffusion fields, etc.

This book is written for those who would like to advance their knowledge beyond an introductory level of biomaterials or materials science and engineering. This requires one to understand more fully the science of materials, which is, of course, the foundation of biomaterials. The subject matter of this book may be divided into three parts: (1) fundamental structure-property relationships of man-made materials (Chapters 2-5) and natural biological materials, including biocompatibility (Chapters 6 and 7); (2) metallic, ceramic, and polymeric implant materials (Chapters 8-10); and (3) actual prostheses (Chapters 11 and 12). This manuscript was initially organized at Clemson University as classnotes for an introductory graduate course on biomaterials. Since then it has been revised and corrected many times based on experience with graduate students at Clemson and at Tulane University, where I taught for two years, 1981-1983, before joining the University of Iowa. I would like to thank the many people who helped me to finish this book; my son Y oon Ho, who typed all of the manuscript into the Apple Pie word processor; my former graduate students, M. Ackley Loony, W. Barb, D. N. Bingham, D. R. Clarke, J. P. Davies, M. F. DeMane, B. J. Kelly, K. W. Markgraf, N. N. Salman, W. J. Whatley, and S. o. Young; and my colleagues, Drs. W. Cooke, D. D. Moyle (Clemson G. H. Kenner (University of Utah), F. University), W. C. Van Buskirk (Tulane University), and Y.

The state of development of composite materials is quite unique in the scientific world with simultaneous advances being made both in their usage and basic understanding. The complexity and high technology required in manufacturing structural parts with these materials as well as the need for fundamental description of their processing and property characteristics necessitates a close col laboration between industrial and academic researchers. This col laboration has become significant not only in solving specific tech nical problems, but in providing a much needed supply of scientists with training and background focused on anticipated demand for further advances in composite usage. The fact that the transportation industry with its current international character has a vital interest in composite materials for weight savings applications has provided a strong incentive for extending these developments beyond national boundaries. An excel lent example of an established international venture is the building of the new generation commercial aircraft by the Boeing Company with composite parts manufactured by Aerita1ia in Italy. Accordingly, we organized a Joint U. S. -Italy Symposium on Composite Materials in Italy which was successfully held on June 15-19, 1981, under the primary sponsorship of NSF in the U. S. A. and CNR in Italy. The strong support we also received from industrial co-sponsors, both from Italy and the U. S. A., as well as our respective academic insti tutions gave us confidence that we were addressing a timely and important area in Science and Engineering with a unique concept."

ISIAME 2000 was organized by the Condensed Matter and Materials Physics Research Group at Old Dominion University, Norfolk, Virginia. It brought together an international group of research scientists and engineers from academia and industry to present details of the most recent investigations on industrially related topics and projects using Mossbauer Spectroscopy as a primary analytical technique. These proceedings inciude the papers presented under the broad topics of Chemistry, Surfaces, Materials Processing, Industrial Processing, and Magnetic and Electronic Materials. Specific research areas drawing much interest include corrosion, catalysis, mechanical alloying, petrochemical, steel and mineralogical processing, nano-phase materials and environmental and pollution monitoring.

The book is of particular interest to university researchers and a very broad range of industrial R&D groups who desire to broaden their knowledge of the latest applications and methods of highly resolved spectroscopic analysis of their products. "

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Intended for engineers from a variety of disciplines dealing with structural materials, this text describes the current state of knowledge. It begins by describing the fracture process at the two extremes of scale: first in the context of atomic structures, then in terms of a continuous elastic medium. Treating the fracture process in increasingly sophisticated ways, the book then considers plastic corrections and the procedures for measuring the toughness of materials. Practical considerations are then discussed, including crack propagation, geometry dependence, flaw density, mechanisms of failure by cleavage, the ductile-brittle transition, and continuum damage mechanics. The whole is rounded off with discussions of generalised plasticity and the link between the microscopic and macroscopic aspects, and problems are provided at the end of each chapter.

In an attempt to meet the demand for new ultra-high strength materials, the processing of novel material configurations with unique microstructure is being explored in systems which are further and further from equilibrium. One such class of emerging materials is the so-called nanophased or nanostructured materials. This class of materials includes metals and alloys, ceramics, and polymers characterized by controlled ultra-fine microstructural features in the form oflayered, fibrous, or phase and grain distribution. While it is clear that these materials are in an early stage of development, there is now a sufficient body of literature to fuel discussion of how the mechanical properties and deformation behavior can be controlled through control of the microstructure. This NATO-Advanced Study Institute was convened in order to assess our current state of knowledge in the field of mechanical properties and deformation behavior in materials with ultra fine microstructure, to identify opportunities and needs for further research, and to identify the potential for technological applications. The Institute was the first international scientific meeting devoted to a discussion on the mechanical properties and deformation behavior of materials having grain sizes down to a few nanometers. Included in these discussions were the topics of superplasticity, tribology, and the supermodulus effect. Lectures were also presented which covered a variety of other themes including synthesis, characterization, thermodynamic stability, and general physical properties."

Photonic Crystal Fibres describes the fundamental properties of the optical waveguides known under the terms of photonic crystal fibres, microstructured fibres, or holey fibres. It outlines how the fibres are designed and fabricated, and how they are treated from a theoretical and numerical point of view. The book presents a detailed description of the different classes of photonic crystal and photonic bandgap fibres, and it broadens out a spectrum of novel applications and new fibre types.

Aspect '94 is the most up-to-date and comprehensive assessment of the present and future of the pipeline systems industry. It comprises papers from leading experts in all areas of pipeline engineering and technology. As this book shows, the last few years have seen great strides forward in the field of subsea pipelines. Deepwater pipelines, long distance pipelines and complex systems transporting hydrocarbons and fluids to and from marginal field subsea wellheads and templates are all being implemented without significant problems. The pace of progress continues to accelerate in the subsea industry, and the scope to make further improvements is constantly being explored. Operators, consultants, suppliers and contractors are all researching, developing and testing new techniques and ideas.

Fundamentals of Friction, unlike many books on tribology, is devoted to one specific topic: friction. After introductory chapters on scientific and engineering perspectives, the next section contains the necessary background within the areas of contact mechanics, surfaces and adhesion. Then on to fracture, deformation and interface shear, from the macroscopic behavior of materials in frictional contact to microscopic models of uniform and granular interfaces. Lubrication by solids, liquids and gases is presented next, from classical flow properties to the reorganization of monolayers of molecules under normal and shear stresses. A section on new approaches at the nano- and atomic scales covers the physics and chemistry of interfaces, an array of visually exciting simulations, using molecular dynamics, of solids and liquids in sliding contact, and related AFM/STM studies. Following a section on machines and measurements, the final chapter discusses future issues in friction.

Micro/nanotribology as a field is concerned with experimental and theoretical investigations of processes ranging from atomic and molecular scales to the microscale, occurring during adhesion, friction, wear, and thin-film lubrication at sliding surfaces. As a field it is truly interdisciplinary, but this confronts the would-be entrant with the difficulty of becoming familiar with the basic theories and applications: the area is not covered in any undergraduate or graduate scientific curriculum. The present work commences with a history of tribology and micro/nanotribology, followed by discussions of instrumentation, basic theories of friction, wear and lubrication on nano- to microscales, and their industrial applications. A variety of research instruments are covered, including a variety of scanning probe microscopes and surface force apparatus. Experimental research and modelling are expertly dealt with, the emphasis throughout being applied aspects.

This book presents an account of the course "Optical Properties of Excited States in Solids" held in Erice, Italy, from June 16 to 3D, 1991. This meeting was organized by the International School of Atomic and Molecular Spectroscopy of the "Ettore Majorana" Centre for Scientific Culture. The purpose of this course was to present physical models, mathematical formalisms and experimental techniques relevant to the optical properties of excited states in solids. Some active physical species, such as ions or radicals, could survive indefinitely if they were completely 'isolated in space. Other active species, such as excited molecular and solid-state systems, are inherently unstable, even in isolation, due to the spontaneous mechanisms that may convert their excitation energies into radiation or heat. Physical parameters that may be used to characterize these excited systems are the localization or delocalization, and the coherence or incoherence, of their state excitations. In solids the excited states, whether they are localized (as for impurities in insulators) or delocalized (as they may occur in semiconductors), are relevant in several regards. Their de-excitation is extremely sensitive to the nature of the excitations of the systems, and a study of the de-excitation processes can yield a variety of information. For example, the excited states may represent the initial condition of the onset of such processes as Stokes-shifted emission, hot luminescence, symmetry-dependent Jahn-Teller and scattering processes, tunneling processes, energy transfer to like and unlike centers, superradiance, coherent radiation, and excited state absorption.