Patterns, Defects and Microstructures in Nonequilibrium Systems

Patterns, Defects and Microstructures in Nonequilibrium Systems PDF Author: D. Walgraef
Publisher: Springer Science & Business Media
ISBN: 9400935595
Category : Technology & Engineering
Languages : en
Pages : 396

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Book Description
One of the most fascinating and intriguing aspects of natural phenomena is that complex systems may undergo symme try-breaking instabilities leading to pattern formation or coherent temporal behavior over macroscopic space and time scales. Therefore the understanding of why order may appear spontananeously in open systems far from equilibrium and which planforms are selected among a large manifold of possi bilities has become a major theme of research both theore- cally and experimentally. These studies, first related to fundamental questions, appear now to be of technological importance, especially for materials science problems. Effectively during the last years, the whole field of materials science experienced a complete renewal. By using techniques able to operate in strong nonequilibrium conditions and hence to escape from the constraints of equilibrium thermodynamics, totally new mate rials structures have been processed. Such techniques inclu de ion implantation, laser beam surface melting as well as electron beam heating. For example, ion implantation proces sing is able to create surfaces with compositions markedly different from the bulk, leading to materials having new electric, magnetic or chemical properties. In laser annea ling, after the tremendously rapid melting and recrystalliza tion of the sample surfaces, microstructures with superior resistance to friction, corrosion, ••• are frozen into place. Rapid solidification of alloys trigger the formation of quasi-crystalline structures. Ion beam mixing can modify the electrical properties of polymers or improve the adhesion of metallic films to ceramics.

Patterns, Defects and Microstructures in Nonequilibrium Systems

Patterns, Defects and Microstructures in Nonequilibrium Systems PDF Author: D. Walgraef
Publisher: Springer Science & Business Media
ISBN: 9400935595
Category : Technology & Engineering
Languages : en
Pages : 396

Get Book Here

Book Description
One of the most fascinating and intriguing aspects of natural phenomena is that complex systems may undergo symme try-breaking instabilities leading to pattern formation or coherent temporal behavior over macroscopic space and time scales. Therefore the understanding of why order may appear spontananeously in open systems far from equilibrium and which planforms are selected among a large manifold of possi bilities has become a major theme of research both theore- cally and experimentally. These studies, first related to fundamental questions, appear now to be of technological importance, especially for materials science problems. Effectively during the last years, the whole field of materials science experienced a complete renewal. By using techniques able to operate in strong nonequilibrium conditions and hence to escape from the constraints of equilibrium thermodynamics, totally new mate rials structures have been processed. Such techniques inclu de ion implantation, laser beam surface melting as well as electron beam heating. For example, ion implantation proces sing is able to create surfaces with compositions markedly different from the bulk, leading to materials having new electric, magnetic or chemical properties. In laser annea ling, after the tremendously rapid melting and recrystalliza tion of the sample surfaces, microstructures with superior resistance to friction, corrosion, ••• are frozen into place. Rapid solidification of alloys trigger the formation of quasi-crystalline structures. Ion beam mixing can modify the electrical properties of polymers or improve the adhesion of metallic films to ceramics.

Patterns, Defects and Materials Instabilities

Patterns, Defects and Materials Instabilities PDF Author: D. Walgraef
Publisher: Springer Science & Business Media
ISBN: 9400905939
Category : Technology & Engineering
Languages : en
Pages : 396

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Book Description
Understanding the origin of spatio-temporal order in open systems far from thermal equilibrium and the selection mechanisms of spatial struc tures and their symmetries is a major theme of present day research into the structures of continuous matter. The development of methods for pro ducing spatially ordered microstructures in solids by non-equilibrium methods opens the door to many technological applications. It is also be lieved that the key to laminar/turbulence transitions in fluids lies in the achievement of spatio-temporal order. Let us also emphasize the fact that the idea of self-organization in it self is at the origin of a reconceptualisation of science. Indeed, the appear ance of order which usually has been associated with equilibrium phase transitions appears to be characteristic of systems far from thermal equi librium. This phenomenon which was considered exceptional at first now the rule in driven systems. The chemical oscillations obtained appears to be in the Belousov-Zhabotinskii reaction were initially considered to be ther modynamically impossible and were rejected by a large number of chemists. Now these oscillations and related phenomena (waves, chaos, etc. ) are the subject of intensive research and new classes of chemical oscil lators have been recently discovered. Even living organisms have long been considered as the result of chance rather than necessity. Such points of view are now abandoned under the overwhelming influence of spatio-tem poral organization phenomena in various domains ranging from physics to biology via chemistry, nonlinear optics, and materials science .

Patterns, Defects and Microstructures in Nonequilibrium Systems

Patterns, Defects and Microstructures in Nonequilibrium Systems PDF Author: D Walgraef
Publisher:
ISBN: 9789400935600
Category :
Languages : en
Pages : 400

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Book Description


Strong resonances of a field of oscillators and defect bifurcation

Strong resonances of a field of oscillators and defect bifurcation PDF Author: Kjartan Emilsson
Publisher: Kjartan Emilsson
ISBN:
Category : Science
Languages : en
Pages : 92

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Book Description
There are two subjects in this thesis. In the first part, a qualitative method to classify and predict the structure of defects in reaction-diffusion systems is introduced. This qualitative approach makes it easier to analyze the behavior of defects in complex systems. It also gives us information about the inner structure of the defect, and from that point of view, it makes it possible to approach the concept of defect bifurcation in a novel manner. In the second part, we study the normal form governing the evolution of a spatially extended homogeneous temporal instability, in the presence of a temporal forcing. This is equivalent to studying strong resonances of a field of nonlinear oscillators. A detailed analysis of the phase space of this normal form reveals a rich dynamical structure, which gives rise to a variety of spatial structures. These include excitable pulses, excitable spirals, fronts and spatially periodic structures. These structures are studied and their possible bifurcations are analyzed from a qualitative point of view.

New Trends in Nonlinear Dynamics and Pattern-Forming Phenomena

New Trends in Nonlinear Dynamics and Pattern-Forming Phenomena PDF Author: Pierre Coullet
Publisher: Springer Science & Business Media
ISBN: 1468474790
Category : Technology & Engineering
Languages : en
Pages : 341

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Book Description
The basic aim of the NATO Advanced Research Workshop on "New Trends in Nonlinear Dynamics and Pattern-Forming Phenomena: The Geometry of Nonequilibrium" was to bring together researchers from various areas of physics to review and explore new ideas regarding the organisation of systems driven far from equilibrium. Such systems are characterized by a close relationship between broken spatial and tempo ral symmetries. The main topics of interest included pattern formation in chemical systems, materials and convection, traveling waves in binary fluids and liquid crystals, defects and their role in the disorganisa tion of structures, spatio-temporal intermittency, instabilities and large-scale vortices in open flows, the mathematics of non-equilibrium systems, turbulence, and last but not least growth phenomena. Written contributions from participants have been grouped into chapters addressing these different areas. For additional clarity, the first chapter on pattern formation has been subdivided into sections. One of the main concerns was to focus on the unifying features between these diverse topics. The various scientific communities repre sented were encouraged to discuss and compare their approach so as to mutually benefit their respective fields. We hope that, to a large degree, these goals have been met and we thank all the participants for their efforts. The workshop was held in Cargese (Corsica, France) at the Institut d'Etudes Scientifiques from August 2nd to August 12th, 1988. We greatly thank Yves Pomeau and Daniel Walgraef who, as members of the organising committee, gave us valuable advice and encouragements.

Free Boundary Problems Involving Solids

Free Boundary Problems Involving Solids PDF Author: J M Chadam
Publisher: CRC Press
ISBN: 9780582087675
Category : Mathematics
Languages : en
Pages : 264

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Book Description
This is the second of three volumes containing the proceedings of the International Colloquium 'Free Boundary Problems: Theory and Applications', held in Montreal from June 13 to June 22, 1990. The main theme of this volume is the concept of free boundary problems associated with solids. The first free boundary problem, the freezing of water - the Stefan problem - is the prototype of solidification problems which form the main part of this volume. The two sections treting this subject cover a large variety of topics and procedures, ranging from a theoretical mathematical treatment of solvability to numerical procedures for practical problems. Some new and interesting problems in solid mechanics are discussed in the first section while in the last section the important new subject of solid-solid-phase transition is examined.

Micromechanics and Inhomogeneity

Micromechanics and Inhomogeneity PDF Author: G.J. Weng
Publisher: Springer Science & Business Media
ISBN: 1461389194
Category : Science
Languages : en
Pages : 647

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Book Description
Toshio Mura has written extensively on micromechanics over the years, and in part due to his writings and many others in the field, micromechanics has gradually emerged as a recognized discipline in the study of mechanics of materials. The idea is to bring both the mechanics and physics on the micro scopic level to the macroscopic scale, so that the deformation and fracture processes of materials can be better understood. While much apparently remains to be done, this approach has already shed new light on certain selected topics and has proved to be fruitful. It is indeed a happy occasion to celebrate both Toshio's upcoming 65th birthday and the emergence of this young science at the same time. The volume contains thirty-seven original articles on the related topics of micromechanics and inhomogeneity; it is presented to Toshio by his friends, colleagues, and admirers as a wish for his good health and continuing pro ductivity. The contributors belong to both the applied mechanics and the materials communities, all with a common belief that micromechanics is an indispensable area of research. It is hoped that this somewhat balanced structure will make the volume more useful to a wider range of readers, and that in the meantime it will still reflect more or less the spectrum of Toshio's lifelong works. As Editors we have at the outset set the highest possible standards for the book, with a keen anticipation that the volume will be widely circulated for many years to come.

Interfacial Wave Theory of Pattern Formation in Solidification

Interfacial Wave Theory of Pattern Formation in Solidification PDF Author: Jian-Jun Xu
Publisher: Springer
ISBN: 3319526634
Category : Science
Languages : en
Pages : 605

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Book Description
This comprehensive work explores interfacial instability and pattern formation in dynamic systems away from the equilibrium state in solidification and crystal growth. Further, this significantly expanded 2nd edition introduces and reviews the progress made during the last two decades. In particular, it describes the most prominent pattern formation phenomena commonly observed in material processing and crystal growth in the framework of the previously established interfacial wave theory, including free dendritic growth from undercooled melt, cellular growth and eutectic growth in directional solidification, as well as viscous fingering in Hele-Shaw flow. It elucidates the key problems, systematically derives their mathematical solutions by pursuing a unified, asymptotic approach, and finally carefully examines these results by comparing them with the available experimental results. The asymptotic approach described here will be useful for the investigation of pattern formation phenomena occurring in a much broader class of inhomogeneous dynamical systems. In addition, the results on global stability and selection mechanisms of pattern formation will be of particular interest to researchers working on material processing and crystal growth. The stability mechanisms of a curved front and the pattern formation have been fundamental subjects in the areas of condensed-matter physics, materials science, crystal growth, and fluid mechanics for some time now. This book offers a stimulating and insightful introduction for all physicists, engineers and applied mathematicians working in the fields of soft condensed-matter physics, materials science, mechanical and chemical engineering, fluid dynamics, and nonlinear sciences.

Synergetics and Dynamic Instabilities

Synergetics and Dynamic Instabilities PDF Author: G. Caglioti
Publisher: Elsevier
ISBN: 0444600922
Category : Mathematics
Languages : en
Pages : 444

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Book Description
This collection of papers presented at the Enrico Fermi School considers the subject of synergetics as a firmly established field of interdisciplinary research, ranging from physics, chemistry and biology, to subjects like economy and sociology. These proceedings focus on the natural sciences.

Nematics

Nematics PDF Author: Jean-Michel Coron
Publisher: Springer Science & Business Media
ISBN: 9401134286
Category : Science
Languages : en
Pages : 426

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Book Description
This volume (>Ie) NEMATICS Mathematical and Physical aspects constitutes the proceedings of a workshop which was held at l'Universite de Paris Sud (Orsay) in May 1990. This meeting was an Advanced Research Workshop sponsored by NATO. We gratefully acknowledge the help and support of the NATO Science Committee. Additional support has been provided by the Ministere des affaires etrangeres (Paris) and by the Direction des Recherches et Etudes Techniques (Paris). Also logistic support has been provided by the Association des Numericiens d'Orsay. (*) These proceedings are published in the framework of the "Contrat DRET W 90/316/ AOOO". v Contents (*) FOREWORD v INTRODUCTION 1. M. CORON, 1. M. GHIDAGLIA, F. HELEIN xi AN ENERGY-DECREASING ALGORITHM FOR HARMONIC MAPS F. ALOUGES 1 A COHOMOLOGICAL CRITERION FOR DENSITY OF SMOOTH MAPS IN SOBOLEV SPACES BETWEEN TWO MANIFOLDS F. BETHUEL, 1. M. CORON, F. DEMENGEL, F. HELEIN 15 ON THE MATHEMATICAL MODELING OF TEXTURES IN POLYMERIC LIQUID CRYSTALS M. C. CAmERER 25 A RESULT ON THE GLOBAL EXISTENCE FOR HEAT FLOWS OF HARMONIC MAPS FROM D2 INTO S2 K. C. CHANG, W. Y. DING 37 BLOW-UP ANALYSIS FOR HEAT FLOW OF HARMONIC MAPS Y. CHEN 49 T AYLOR-COUETTE INSTABILITY IN NEMATIC LIQUID CRYSTALS P. E. ClADIS 65 ON A CLASS OF SOLUTIONS IN THE THEORY OF NEMATIC PHASES B. D. COLEMAN, 1. T. JENKINS 93 RHEOLOGY OF THERMOTROPIC NEMATIC LIQUID CRYSTALLINE POLYMERS M. M. DENN, 1. A.