We present here the lectures and a selection of the seminars given at the Ninth International Workshop on Instabilities and Nonequilibrium Structures which took place in Vifiadel Mar, Chile, in December 2001. The Workshop was organized by Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Instituto de Fisica of Universidad Cat6lica de Valparaiso, Centro de Fisica No Lineal y Sistemas Complejos de Santiago and Facultad de Ingenieria, Universidad de los Andes, which starting from this year joins the other institutions in the coorganization ofthe Workshop. The organizers would like to express their gratitude to the following sponsors: Facultad de Ciencias Fisicas y Matematicas de la Universidad de Chile, Instituto de Fisica de la Universidad Cat6lica de Valparaiso, Facultad de Ingenieria de la Universidad de los Andes, Centro de Fisica No Lineal y Sistemas Complejos de Santiago, Academia Chilena de Ciencias, Ministere Francais des Affaires Etrangeres, CONICYT (Comisi6n Nacional de Investigaci6n Cientifica y Tecno16gicade Chile) and Departamento Tecnico de Investigaci6n y de Relaciones Internacionales de la Universidad de Chile. Enrique Tirapegui PREFACE This book consists of two parts, the first one has three lectures written by Professors H. R. Brand, M. Moreau and L. S. Tuckerman. H. R. Brand gives an overview about reorientation and undulation instabilities in liquid crystals, M. Moreau presents recent results on biased tracer diffusion in lattice gases, finally, L. S. Tuckerman summarizes some numerical methods used in bifurcation problems.

The nine review articles and roughly 30 contributed papers contained in this volume survey the present understanding of the molecular motion of polymers in concentrated solutions, melts and the amorphous state. Although the main emphasis is on results from neutron scattering experiments, about half of the contributions relate to complementary techniques such as light scattering and NMR. The book highlights three areas of active reseach that have received increasing attention in recent years. First, work on polymer relaxation near the glass transition and in glassy systems has shown that the application of different experimental techniques is indispensable due to the broad range of time scales over which these phenomena occur on a molecular level. Second, it is reported that the internal Brownian motion of long chain molecules and their diffusion in an entangled environment still does not have a generally accepted physical picture, although detailed insights into the microscopic motion have been obtained. Third, important progress has been made in unravelling the characteristics of phase separation of polymer blends, in which modifications to the ordinary laws of diffusion are of particular interest.

There were two reasons that induced me to plan and to organize this book, the first was the lack of a text entirely devoted to the subject of gas sensors, notwithstanding some books devoted to the various kind of chemical sensors have recently been published. The second reason was the need of introducing the basic topics of gas detection mechanisms to a growing number of researchers active in research and development laboratories of industries and uni versities. The field of chemical sensors is indeed in fast and consistent growth, as it is proved by the increased number of participants to the congresses that were recently held on this subject, namely the Third Meeting on Chemical Sensors (September 24 - 26, 1990, Cleveland), Transducers' 91 (June 24 - 27, 1991, S. Francisco) and EUROSENSORS V (September 30 - October 3, 1991, Rome). Therefore, this book is mainly intended as a reference text for researchers with a MS degree in physics, chemistry and electrical engineering; it reports the last progresses in the R. & D. and in the technology of gas sensors. I choose to deal specifically with the topic of gas sensors because these devices show a very large number of applications in the domestic and industrial field and they are characterized by a great effort of research and development.

Frontiers in Magnetism of Reduced Dimension Systems presents a definitive statement of our current knowledge and the state of the art in a field that has yet to achieve maturity, even though there are a number of potential applications of thin magnetic films and multilayers, such as magnetic sensors, data storage/retrieval media, actuators, etc. The book is organized into 13 chapters, each including a lecture and contributed papers on a similar subject. Five chapters deal with theoretical descriptions of electron transport phenomena, relaxation processes, nonlinear paramagnetic interactions, phase transitions and macroscopic quantum effects in magnetic films and particles. The description of different characterization techniques occupies an important place in the book. Separate chapters are dedicated to magnetic resonances (FMR, SWR, NMR), magneto-optical spectroscopy, controlling chaos, magnetoelastic phenomena and magnetic resonance force microscopy. A further chapter gives a detailed review, spread over a number of papers, of materials in current use in information storage devices.

In the ten years since the scientific rationale for the design, synthesis and application of inorganic and organometallic polymers (IOPs) was first conceptualised, we have witnessed the first tentative exploration of IOPs as precursors to new materials, with efforts focusing on the design and synthesis of novel ceramic precursors. Developing expertise led to precursor studies combined with the characterisation of the transformation processes that occur when IOPs are converted to ceramic materials. Now at maturity, the science presented in this volume reveals the polymer precursor approach to materials synthesis together with examples of processing ceramic shapes for a range of mechanical properties, the development of sophisticated, noninvasive analytical techniques, and IOP design rationales relying on well-defined processing-property relationships. The production of multifunctional IOPs is described, providing ion conductivity, gas sensing, bioactivity, magnetic properties, etc., combined with processability. The existence of well-defined IOPs and the exquisite control that can be exerted on sol-gel systems now provide access to such a variety of mixed organic-organometallic and/or inorganic hybrid systems that their exploitation is likely to develop into an entirely new field of materials chemistry. Future exciting avenues of research are also being opened up with the advent of buckyballs, Met-Cars, dopable preceramics, rigid-rod organometallics, and molecular tinkertoys.

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.

Since their inception more than 2.5 years ago, photon correlation techniques for the spatial, temporal or spectral analysis of fluctuating light fields have found an ever-widening range of applications. Using detectors which re spond to single quanta of the radiation field, these methods are intrinsically digital in natnre and in many experimental situations offer a unique degree of accuracy and sensitivity, not only for the study of primary light sources themselves, but most particularly in the use of a laser-beam probe to study light scattering from pure fluids, macromolecular suspensions and laminar or turbulent flowing fluids and gases. Following the earliest developments in laser scattering by dilute macro nl01ecular suspensions, in, ... hich particle sizing was the main aim, and the use of photon correlation techniques for laser-Doppler studies of flow and tnrbuence. both of which areas were the subject of NATO ASls in Capri, Italy in 19; 3 and 19;6. significant advances have be('n made in recent years in many other areas. These were reflected in the topics covered in this NATO Advanced Research Workshop, which took place from August 2;th to 30th, 1 ) }6, at the Jagiellonian University, Krakow, Poland. These in cluded ('xperimental techniques. statist.ics and data reduction, colloids and aggregation, polymers, gels, liquid crystals and mixtures, protein solutions, critical pllf'nomena and dense media."

The Advanced Study Institute (AS!) considered a number offacets of the very rapidly advancing field of theoretical and experimental aspects of ultrashort processes in condensed matter. Common threads exist between a series of example cases. One major subgroup of topics involves the ultrashort dynamics of excitations of various "particles" produced through the interactions of condensed matter with ultrashort duration laser light. Examples ofthe excitations include electronic and hole carriers, electron-hole plasma, phonons, vibrons and rotons, two phonon states, and excitons. Experimentation on the dynamics of such excitations, are carried out in the bulk, at surfaces, in thin films, and in quantum wells. The dynamical steps which the excitations usually undergo include photo-excitation, local thermalization, particle-particle interaction, particle phonon interactions and eventual return to true thermal equilibrium. This ASI was organized to benefit particularly advanced graduate students, specifically, those near the end of their Ph.D. thesis projects, and also for postdoctoral scholars already active in the field. The overall organizational goal was centered around a set oftutorially based lectures intermingled with full scale discussion periods of equal time and importance as the lectures. The general discussion periods were designed to offer to the participants ample time to ask detailed questions and to make comments and contributions of their own. In order to complete the involvement of the participants a full length poster session was also held. A representative set of abstracts of these posters appear as an Appendix to the lectures.

Singularities in Fluids, Plasmas and Optics, which contains the proceedings of a NATO Workshop held in Heraklion, Greece, in July 1992, provides a survey of the state of the art in the analysis and computation of singularities in physical problems drawn from fluid mechanics, plasma physics and nonlinear optics. The singularities include curvature singularities on fluid interfaces, the onset of turbulence in 3-D inviscid flows, focusing singularities for laser beams, and magnetic reconnection. The highlights of the book include the nonlinear Schrodinger equation for describing laser beam focusing, the method of complex variables for the analysis and computation of singularities on fluid interfaces, and studies of singularities for the 3-D Euler equations. The book is suitable for graduate students and researchers in these areas."

Significant experimental work is devoted to the preparation of one and zero dimensional semiconductor structures in view of future electronic and optical devices which involve quantum effects. The aim is good control in the realisation of nanometer structures both in vertical and lateral direction. Conventional processing techniques based on lithography face inherent problems such as limited resolution and surface defects caused by reactive ion etching. During the last few years several research groups started working on direct syntheses of semiconductor nanostructures by combining epitaxial growth techniques such as molecular beam epitaxy and chemical vapour deposition with pre patterning of the substrate wafers. Another idea is based on island formation in strained layer heteroepitaxy. Zero and one dimensional structures with dimensions down to a few atomic distances have been realised this way. An important point is that the size of the quantum structures is controlled within the epitaxial deposition in a self-adjusting process. The main subjects of the book are: Theoretical aspects of epitaxial growth, selfassembling nanostructures and cluster formation, epitaxial growth in tilted and non-(001) surfaces, cleaved edge overgrowth, nanostructure growth on patterned silicon substrates, nanostructures prepared by selective area epitaxy or growth on patterned substrates, in-situ etching and device applications based on epitaxial regrowth on patterned substrates. The experimental work mainly concentrated on GaAs/A1GaAs, GaAs/InGaAs, InGaP/InP and Si/SiGe based semiconductor heterostructures. Growth related problems received special attention. The different concepts for preparation of low dimensional structures are presented to allow direct comparison and to identify new concepts for future research work.

This book constitutes the Proceedings of the 26th Symposium on Acoustical Imaging held inWindsor, Ontario, Canada during September 9-12, 2001. This traditional scientific event is recognized as a premier forum for the presentation of advanced research results in both theoretical and experimental development. The lAIS was conceived at a 1967Acoustical Holography meeting in the USA. Since then, these traditional symposia provide an opportunity for specialists who are working in this area to make new acquaintances, renew old friendships and present recent results of their research. Our Symposium has grown significantly in size due to a broad interest in various topics and to the quality of the presentations. For the firsttime in 40 years, the IAIS was held in the province of Ontario in Windsor, Canada's Automotive Capital and City of Roses. The 26th IAIS attracted over 100specialists from 13countries representing this interdisciplinary field in physical acoustics, image processing, applied mathematics, solid-state physics, biology and medicine, industrial applications and quality control technologies. The 26th lAIS was organized in the traditional way with only one addition-a Special Session "History of Acoustical Imaging" with the involvement of such well known scientists as Andrew Briggs, Noriyoshi Chubachi, Robert Green Jr., Joie Jones, Kenneth Erikson, and Bernhard Tittmann. Many of these speakers are well known scientists in their fields and we would like to thank them for making this session extremely successful.

Remarkable advances in semiconductor growth and processing technologies continue to have a profound impact on condensed-matter physics and to stimulate the invention of novel optoelectronic effects. Intensive research on the behaviors of free carriers has been carried out in the two-dimensional systems of semiconductor heterostructures and in the one and zero-dimensional systems of nanostructures created by the state-of-the-art fabrication methods. These studies have uncovered unexpected quantum mechanical correlations that arise because of the combined effects of strong electron-electron interactions and wave function confinement associated with reduced dimensionality. The investigations of these phenomena are currently at the frontiers of condensed-matter physics. They include areas like the fractional quantum Hall effect, the dynamics of electrons on an ultra short (femtosecond) time scale, electron behavior in quantum wires and dots, and studies of electron tunneling phenomena in ultra small semiconductor structures. Optical techniques have made important contributions to these fields in recent years, but there has been no coherent review of this work until now. The book provides an overview of these recent developments that will be of interest to semiconductor materials scientists in university, government and industrial laboratories.

The last decade has witnessed significant advances in the ability to generate short light pulses throughout the optical spectrum. These developments have had a tremendous impact on the field of chemical dynamics. Fundamental questions concerning chemical reactions, once thought to be unaddressable, are now easily studied in real-time experiments. Ultrafast spectroscopies are currently being used to study a variety of fundamental chemical phenomena. This book focuses on some of the experimental and associated theoretical studies of reactions in clusters, liquid and solid media. Many of the advances in our understanding of the fundamental details of chemical reactivity result from the interplay of experiment and theory. This theme is present in many of the chapters, indicating the pervasiveness of a combined approach for eludicating molecular models of chemical reactions. With parallel developments in computer simulation, complex chemical sys tems are being studied at a molecular level. The discussions presented in this book recount many areas at the forefront of "ultrafast chemistry". They serve the purpose of both bringing the expert up to date with the work being done in many laboratories as well as introducing those not directly involved in this field to the diverse set of problems that can be studied. I hope that this book conveys the excitement that both I and the other authors in this volume feel about the field of ultrafast chemistry. John D. Simon 1993 1.D. Simon (ed.), Ultrafast Dynamics of Chemical Systems, vii.

A revolution similar to that brought by CCDs to visible astronomy is still ahead in IR and submillimeter astronomy. There is certainly no wavelength range which has, over the past several years, seen such impressive advances in technology: large-scale detector arrays, new designs for cooling in space, lightweight mirror technologies. Scientific cases for observing the cold universe are outstanding. Observations in the FIR/Submm range will provide answers to such fundamental questions as: What is the spectrum of the primordial fluctuations? How do primeval galaxies look? What are the first stages of star formation? Most of the international space missions that have been triggered by these questions are presented in detail here. Technological issues raised by these missions are reviewed, as are the most recent achievements in cooling and detector technologies.

The creation of molecular materials that have desired electrical conductance and magnetic properties demands the precise arrangement of molecules in the solid state. Such controlled arrangement has been achieved very elegantly by supramolecular chemists, especially those practising crystal engineering. This book, which presents articles by foremost experts in crystal engineering, molecular conductors and magnetic magnetism, reveals the results of an interdisciplinary union that may well have a profound influence on the future of materials science. Theoretical studies reveal potential areas of interest for those investigating molecular conductors and magnets, as well as materials that exhibit both properties. A unique survey of the state of the art appealing to all those doing research in supramolecular chemistry and materials science.

Quantum Systems in Chemistry and Physics contains a refereed selection of the papers presented at the first European Workshop on this subject, held at San Miniato, near Pisa, Italy, in April 1996. The Workshop brought together leading experts in theoretical chemistry and molecular physics with an interest in the quantum mechanical many-body problem. This volume provides an insight into the latest research in this increasingly important field. Throughout the Workshop, the emphasis was on innovative theory and conceptual developments rather than on computational implementation. The various contributions presented reflect this emphasis and embrace topics such as density matrices and density functional theory, relativistic formulations, electron correlation, valence theory, nuclear motion, response theory, condensed matter, and chemical reactions. Audience: The volume will be of interest to those working in the molecular sciences and to theoretical chemists and molecular physicists in particular.

The main motivation for the organization of the Advanced Research Workshop in Belgirate was the promotion of discussions on the most recent issues and the future perspectives in the field of Solid State lonics. The location was chosen on purpose since Belgirate was the place were twenty years ago, also then under the sponsorship of NATO, the very first international meeting on this important and interdisciplinary field took place. That meeting was named "Fast Ion Transport in Solids" and gathered virtually everybody at that time having been active in any aspect of motion of ions in solids. The original Belgirate Meeting made for the first time visible the technological potential related to the phenomenon of the fast ionic transport in solids and, accordingly, the field was given the name "Solid State lonics." This field is now expanded to cover a wide range of technologies which includes chemical sensors for environmental and process control, electrochromic windows, mirrors and displays, fuel cells, high performance rechargeable batteries for stationary applications and electrotraction, chemotronics, semiconductor ionics, water electrolysis cells for hydrogen economy and other applications. The main idea for holding an anniversary meeting was that of discussing the most recent issues and the future perspectives of Solid State lonics just twenty years after it has started at the same location on the lake Maggiore in North Italy.

The development of new materials is recognized as one of the major elements in the overall technological evolution that must go on in order to sustain and even improve the quality of life for citizens of all nations. There are many components to this development, but one is to achieve a better understanding of the properties of materials using the most sophisticated scientific tools that are available. As condensed matter physicists and materials scientists work toward this goal, they find that it is useful to divide their efforts and focus on specific areas, because certain analytical and theoretical techniques will be more useful for the study of one class of materials than another. One such area is the study of metals and metallic alloys, which are used in the manufacture of products as diverse as automobiles and space stations. Progress in this area has been very rapid in recent years, and the new developments come from many different countries. For these reasons the Advanced Research Workshop Programme in the NATO Scientific Affairs Division has seen fit to sponsor several meetings to bring together the researchers and students working in this field from the NATO countries and elsewhere. There have been a series of NATO-ASI's that have dealt with the results of research on the electronic structure of materials and the properties of metals, alloys, and interfaces. They are: "Electrons in finite and infinite structures" P. Phariseau and L.

The motion of a particle in a random potential in two or more dimensions is chaotic, and the trajectories in deterministically chaotic systems are effectively random. It is therefore no surprise that there are links between the quantum properties of disordered systems and those of simple chaotic systems. The question is, how deep do the connec tions go? And to what extent do the mathematical techniques designed to understand one problem lead to new insights into the other? The canonical problem in the theory of disordered mesoscopic systems is that of a particle moving in a random array of scatterers. The aim is to calculate the statistical properties of, for example, the quantum energy levels, wavefunctions, and conductance fluctuations by averaging over different arrays; that is, by averaging over an ensemble of different realizations of the random potential. In some regimes, corresponding to energy scales that are large compared to the mean level spacing, this can be done using diagrammatic perturbation theory. In others, where the discreteness of the quantum spectrum becomes important, such an approach fails. A more powerful method, devel oped by Efetov, involves representing correlation functions in terms of a supersymmetric nonlinear sigma-model. This applies over a wider range of energy scales, covering both the perturbative and non-perturbative regimes. It was proved using this method that energy level correlations in disordered systems coincide with those of random matrix theory when the dimensionless conductance tends to infinity.

Readers intent on mastering the basics should start by reading the first few overview chapters and then delve into the descriptions of specific current applications to see how they actually work. Important future applications are also outlined, including information storage, materials for computer memories, quantum computers, isotopic fibers, isotopic optoelectronics, and quantum electronics.

This volume contains the proceedings of the Fourth Taniguchi International Symposium on the Theory of Condensed Matter, which was held at Senkari Semi nar House of Kwansei Gakuin Universi y in Sanda-shi, Japan, during the period of 3-8 November 1981. The topic of the symposium was "Anderson rocalization," one of the most fundamental problems in condensed-matter physics. Since Anderson's classic paper was published in 1958, much theoretical and experimental effort has been performed to study the problem of electron localization in a random potential. Quite recently, Abrahams, Anderson, Licciardello, and Ramakrishnan proposed a scaling theory of the Anderson lo calization which made it possible to perform microscopic investigations. Rapid progress has followed and we are now getting a coherent picture of the behavior of electrons in disordered systems. When we organized the symposium, we asked Dr. Anderson to participate in it and to give a review talk on theoretical aspects of the problem. Though he kindly accepted our invitation, he could not come due to a sudden illness. A review talk was given by Professor Thouless who kindly accepted our request to take the place of Dr. Anderson. Fortunately, Dr. Anderson has since re covered from his illness."

Advances in the Theory of Atomic and Molecular Systems, is a collection of contributions presenting recent theoretical and computational developments that provide new insights into the structure, properties, and behavior of a variety of atomic and molecular systems. This volume (subtitled: Conceptual and Computational Advances in Quantum Chemistry) focuses on electronic structure theory and its foundations.

This volume is an invaluable resource for faculty, graduate students, and researchers interested in theoretical and computational chemistry and physics, physical chemistry and chemical physics, molecular spectroscopy, and related areas of science and engineering.

Astronomical jets are key astrophysical phenomena observed in gamma-ray bursts, active galactic nuclei or young stars. Research on them has largely occurred within the domains of astronomical observations, astrophysical modeling and numerical simulations, but the recent advent of high energy density facilities has added experimental control to jet studies. Front-line research on jet launching and collimation requires a highly interdisciplinary approach and an elevated level of sophistication. Bridging the gaps between pure magnetohydrodynamics, thermo-chemical evolution, high angular resolution spectro-imaging and laboratory experiments is no small matter. This volume strives to bridge those very gaps. It offers a series of lectures which, taken as whole, act as a thorough reference for the foundations of this discipline. These lectures address the following: * laboratory jets physics from laser and z-pinch plasma experiments, * the magnetohydrodynamic theory of relativistic and non-relativistic stationary jets, * heating mechanisms in magnetohydrodynamic jets, from the solar magnetic reconnection to the molecular shock heating perspectives, * atomic and molecular microphysics of jet shocked material. In addition to the lectures, the book offers, in closing, a presentation of a series of observational diagnostics, thus allowing for the recovery of basic physical quantities from jet emission lines.

The first ever book on the applications of fullerenes and nanotubes. World's experts on the industrial use of these new forms of carbon contributes chapters, that are based on lectures given in a large workshop held on February 2001, and expanded thereafter. The contents are intended for those who are interested in the exploration of industrial applications of fullerenes and carbon nanotubes.

'Et moi, ..., si j'avait su comment en revenir, One service mathematics has rendered the je n'y serais point alle.' human race. It has put common sense back Jules Verne where it belongs, on the topmost shelf next to the dusty canister labelled 'discarded non- The series is divergent; therefore we may be sense'. able to do something with it. Eric T. Bell O. Heaviside Mathematicsis a tool for thought. A highly necessary tool in a world where both feedback and non- linearities abound. Similarly, all kinds of parts of mathematics seIVe as tools for other parts and for other sciences. Applying a simple rewriting rule to the quote on the right above one finds such statements as: 'One seIVice topology has rendered mathematical physics ...'; 'One service logic has rendered com- puter science ...'; 'One service category theory has rendered mathematics ...'. All arguably true. And all statements obtainable this way form part of the raison d'etre of this series.