The Validity Of Classical Nucleation Theory And Its Application To Dislocation Nucleation

Author : Seunghwa Ryu
Publisher : Stanford University
Page : 240 pages
File Size : 51,7 Mb
Release : 2011
Category : Electronic
ISBN : STANFORD:rx036ms4124

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The Validity of Classical Nucleation Theory and Its Application to Dislocation Nucleation by Seunghwa Ryu Pdf

Nucleation has been the subject of intense research because it plays an important role in the dynamics of most first-order phase transitions. The standard theory to describe the nucleation phenomena is the classical nucleation theory (CNT) because it correctly captures the qualitative features of the nucleation process. However potential problems with CNT have been suggested by previous studies. We systematically test the individual components of CNT by computer simulations of the Ising model and find that it accurately predicts the nucleation rate if the correct droplet free energy computed by umbrella sampling is provided as input. This validates the fundamental assumption of CNT that the system can be coarse grained into a one dimensional Markov chain with the largest droplet size as the reaction coordinate. Employing similar simulation techniques, we study the dislocation nucleation which is essential to our understanding of plastic deformation, ductility, and mechanical strength of crystalline materials. We show that dislocation nucleation rates can be accurately predicted over a wide range of conditions using CNT with the activation free energy determined by umbrella sampling. Our data reveal very large activation entropies, which contribute a multiplicative factor of many orders of magnitude to the nucleation rate. The activation entropy at constant strain is caused by thermal expansion, with negligible contribution from the vibrational entropy. The activation entropy at constant stress is significantly larger than that at constant strain, as a result of thermal softening. The large activation entropies are caused by anharmonic effects, showing the limitations of the harmonic approximation widely used for rate estimation in solids. Similar behaviors are expected to occur in other nucleation processes in solids.

Author : Ken Kelton,Alan Lindsay Greer
Publisher : Elsevier
Page : 759 pages
File Size : 55,8 Mb
Release : 2010-03-19
Category : Technology & Engineering
ISBN : 9780080912646

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Nucleation in Condensed Matter by Ken Kelton,Alan Lindsay Greer Pdf

In Nucleation in Condensed Matter, key theoretical models for nucleation are developed and experimental data are used to discuss their range of validity. A central aim of this book is to enable the reader, when faced with a phenomenon in which nucleation appears to play a role, to determine whether nucleation is indeed important and to develop a quantitative and predictive description of the nucleation behavior. The third section of the book examines nucleation processes in practical situations, ranging from solid state precipitation to nucleation in biological systems to nucleation in food and drink. Nucleation in Condensed Matter is a key reference for an advanced materials course in phase transformations. It is also an essential reference for researchers in the field. Unified treatment of key theories, experimental evaluations and case studies Complete derivation of key models Detailed discussion of experimental measurements Examples of nucleation in diverse systems

Author : V.I. Kalikmanov
Publisher : Springer
Page : 319 pages
File Size : 49,9 Mb
Release : 2012-11-28
Category : Science
ISBN : 9789048136438

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Nucleation Theory by V.I. Kalikmanov Pdf

One of the most striking phenomena in condensed matter physics is the occurrence of abrupt transitions in the structure of a substance at certain temperatures or pressures. These are first order phase transitions, and examples such as the freezing of water are familiar in everyday life. The conditions at which the transformation takes place can sometimes vary. For example, the freezing point of water is not always 0°C, but the liquid can be supercooled considerably if it is pure enough and treated carefully. The reason for this phenomenon is nucleation. This monograph covers all major available routes of theoretical research of nucleation phenomena (phenomenological models, semi-phenomenological theories, density functional theories, microscopic and semi-microscopic approaches), with emphasis on the formation of liquid droplets from a metastable vapor. Also, it illustrates the application of these various approaches to experimentally relevant problems. In spite of the familiarity of the involved phenomena, it is still impossible to calculate nucleation accurately, as the properties and the kinetics of the daughter phase are insufficiently well known. Existing theories based upon classical nucleation theory have on the whole explained the trends in behavior correctly. However they often fail spectacularly to account for new data, in particular in the case of binary or, more generally, multi-component nucleation. The current challenge of this book is to go beyond such classical models and provide a more satisfactory theory by using density functional theory and microscopic computer simulations in order to describe the properties of small clusters. Also, semi-phenomenological models are proposed, which attempt to relate the properties of small clusters to known properties of the bulk phases. This monograph is an introduction as well as a compendium to researchers in soft condensed matter physics and chemical physics, graduate and post-graduate students in physics and chemistry starting on research in the area of nucleation, and to experimentalists wishing to gain a better understanding of the efforts being made to account for their data.

Author : Eli Ruckenstein,Gersh Berim
Publisher : CRC Press
Page : 476 pages
File Size : 44,7 Mb
Release : 2016-06-20
Category : Science
ISBN : 9781138032170

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Kinetic Theory of Nucleation by Eli Ruckenstein,Gersh Berim Pdf

Explore a Kinetic Approach to the Description of Nucleation – An Alternative to the Classical Nucleation Theory Kinetic Theory of Nucleation presents an alternative to the classical theory of nucleation in gases and liquids—the kinetic nucleation theory of Ruckenstein–Narsimhan–Nowakowski (RNNT). RNNT uses the kinetic theory of fluids to calculate the rate of evaporation of molecules from clusters, and unlike the classical nucleation theory (CNT), does not require macroscopic thermodynamics or the detailed balance principle. The book compares the rates of evaporation of molecules from—and condensation on—the surface of a nucleus of a new phase, and explains how this alternate approach can provide much higher nucleation rates than the CNT. It applies RNNT to various case studies that include the liquid-to-solid and vapor-to-liquid phase transitions, binary nucleation, heterogeneous nucleation, nucleation on soluble particles and protein folding. It also describes the system, introduces the basic equations of the kinetic theory, and defines a new model for the nucleation mechanism of protein folding. Adaptable to coursework as well as self-study, this insightful book: Uses a kinetic approach to calculate the rate of growth and decay of a cluster Includes description of vapor-to-liquid and liquid-to-solid nucleation Outlines the application of density-functional theory (DFT) methods to nucleation Proposes the combination of the new kinetic theory of nucleation with the DFT methods Illustrates the new theory with numerical calculations Describes the model for the nucleation mechanism of protein folding, and more A comprehensive guide dedicated to the kinetic theory of nucleation and cluster growth, Kinetic Theory of Nucleation emphasizes the basic concepts of the kinetic nucleation theory, incorporates findings developed from years of research and experience, and is written by highly-regarded experts.

Author : C.E. Campbell,M.V. Manuel,W. Xiong
Publisher : ASM International
Page : 128 pages
File Size : 50,5 Mb
Release : 2017-10-01
Category : Technology & Engineering
ISBN : 9781627081382

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Transformations Selected Works of G.B. Olson on Materials, Microstrucutre, and Design by C.E. Campbell,M.V. Manuel,W. Xiong Pdf

ASM International and The Minerals, Metals and Materials Society (TMS) have collaborated to present a collection of the selected works of Dr. Greg B. Olson in honor of his 70th birthday in 2017. This collection highlights his influential contributions to the understanding of martensite transformations and the development and application of a systems design approach to materials. Part I: Martensite, with an Introduction by Sir Harry Bhadeshia, emphasizes Dr. Olson's work to develop a dislocation theory for martensite transformations, to improve the understanding of the statistical nature of martensite nucleation, and to expand use of quantitative microscopy to characterize phase transformations. Part II: Materials Design, with an Introduction by Dr. Charles Kuehmann, focuses on the application of a systems design approach to materials and the development of integrated computational design curriculum for undergraduate education. Part II includes several examples of the systems design approach to a variety of applications. The papers chosen for this collection were selected by the editors with input from Dr. Olson.

Author : Anonim
Publisher : Springer
Page : 334 pages
File Size : 41,6 Mb
Release : 2012-11-26
Category : Electronic
ISBN : 9048136482

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Nucleation Theory by Anonim Pdf

Author : J.M.P.Q. Delgado
Publisher : Springer Science & Business Media
Page : 286 pages
File Size : 53,6 Mb
Release : 2013-08-17
Category : Technology & Engineering
ISBN : 9783642374692

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Industrial and Technological Applications of Transport in Porous Materials by J.M.P.Q. Delgado Pdf

The purpose of this book, Industrial and Technological Applications of Transport in Porous Materials, is to provide a collection of recent contributions in the field of heat and mass transfer in porous media and their industrial and technological applications. The main benefit of the book is that it discusses some of the most important topics related to transport phenomenon in engineering and their future applications. It includes a set of new technological applications in the field of heat and mass transfer phenomena in a porous medium domain, such as, drying technology, filtration, infrared thermography, energy, recycling, etc. At the same time, these topics will be going to the encounter of a variety of scientific and engineering disciplines, such as chemical, civil, agricultural, mechanical engineering, etc. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

Author : Markus J. Buehler
Publisher : Springer Science & Business Media
Page : 547 pages
File Size : 45,9 Mb
Release : 2008-08-07
Category : Science
ISBN : 9780387764269

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Atomistic Modeling of Materials Failure by Markus J. Buehler Pdf

This is an introduction to molecular and atomistic modeling techniques applied to fracture and deformation of solids, focusing on a variety of brittle, ductile, geometrically confined and biological materials. The overview includes computational methods and techniques operating at the atomic scale, and describes how these techniques can be used to model cracks and other deformation mechanisms. The book aims to make new molecular modeling techniques available to a wider community.

Author : Anonim
Publisher : Unknown
Page : 614 pages
File Size : 44,5 Mb
Release : 1987
Category : Naval art and science
ISBN : UCR:31210023608076

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Office of Naval Research by Anonim Pdf

Author : Anonim
Publisher : Elsevier
Page : 551 pages
File Size : 47,8 Mb
Release : 2011-09-22
Category : Science
ISBN : 9780080564982

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Dislocations in Solids by Anonim Pdf

New models for dislocation structure and motion are presented for nanocrystals, nucleation at grain boundaries, shocked crystals, interphase interfaces, quasicrystals, complex structures with non-planar dislocation cores, and colloidal crystals. A review of experimentally established main features of the magnetoplastic effect with their physical interpretation explains many diverse results of this type. The model has many potential applications for forming processes influenced by magnetic fields. Dislocation model for the magnetoplastic effect New mechanism for dislocation nucleation and motion in nanocrystals New models for the dislocation structure of interfaces between crystals with differing crystallographic structure A unified view of dislocations in quasicrystals, with a new model for dislocation motion A general model of dislocation behavior in crystals with non-planar dislocation cores Dislocation properties at high velocities Dislocations in colloidal crystals

Author : Margrit Hanbücken,Pierre Müller,Ralf B. Wehrspohn
Publisher : John Wiley & Sons
Page : 354 pages
File Size : 55,7 Mb
Release : 2011-12-07
Category : Technology & Engineering
ISBN : 9783527639557

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Mechanical Stress on the Nanoscale by Margrit Hanbücken,Pierre Müller,Ralf B. Wehrspohn Pdf

Bringing together experts from the various disciplines involved, this first comprehensive overview of the current level of stress engineering on the nanoscale is unique in combining the theoretical fundamentals with simulation methods, model systems and characterization techniques. Essential reading for researchers in microelectronics, optoelectronics, sensing, and photonics.

Author : Evgeni B. Budevski,Georgi T. Staikov,Wolfgang J. Lorenz
Publisher : John Wiley & Sons
Page : 421 pages
File Size : 45,7 Mb
Release : 2008-07-11
Category : Science
ISBN : 9783527614929

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Electrochemical Phase Formation and Growth by Evgeni B. Budevski,Georgi T. Staikov,Wolfgang J. Lorenz Pdf

Electrochemical processes and methods are basic to many important scientific disciplines, materials science and nanotechnology being only two keywords. For the first time in more than twenty years this volume presents a critical survey of the foundations, methodology and applications of electrochemical phase formation and growth processes. Written by a team of three internationally renowned authors, it is an invaluable source of information for all scientists concerned with electrocrystallization of metals or the in-situ characterization of electron-conducting surfaces. Not only the numerous illustrations (partly in colour) but also the vast number of references covering the literature up to and including 1995 make this volume indispensable for every laboratory working in electrochemical or materials science.

Author : Anonim
Publisher : Unknown
Page : 816 pages
File Size : 43,5 Mb
Release : 1979
Category : Crystallography
ISBN : UCAL:B3024003

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Proceedings of the International Conference on Martensitic Transformations by Anonim Pdf

Author : K. Sangwal
Publisher : Elsevier
Page : 518 pages
File Size : 48,7 Mb
Release : 2012-12-02
Category : Science
ISBN : 9780444599018

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Etching of Crystals by K. Sangwal Pdf

Defects in Solids, Volume 15: Etching of Crystals: Theory, Experiment, and Application focuses on the processes, reactions, and methodologies involved in the etching of crystals, including thermodynamics and diffusion. The publication first underscores the defects in crystals, detection of defects, and growth and dissolution of crystals. Discussions focus on thermodynamic theories, nature of pit sites, surface roughening during diffusion-controlled dissolution, growth controlled by simultaneous mass transfer and surface reactions, and chemical and thermal etching. The text then examines the theories of dissolution and etch-pit formation and the chemical aspects of the dissolution process, including catalytic reactions, dissolution of semiconductors, topochemical adsorption theories, and diffusion theories. The book tackles the solubility of crystals and complexes in solution and the kinetics and mechanism of dissolution. Topics include metallic crystals, semiconductors, stability of complexes, relationship between solubility, surface energy, and hardness of crystals, and solvents for crystals and estimation of crystal solubility in solvents other than water. The publication is a dependable source of data for readers interested in the etching of crystals.

Author : J.W. Christian
Publisher : Newnes
Page : 1200 pages
File Size : 44,7 Mb
Release : 2002-12-10
Category : Technology & Engineering
ISBN : 9780080542775

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The Theory of Transformations in Metals and Alloys by J.W. Christian Pdf

This work is a classic reference text for metallurgists, material scientists and crystallographers. The first edition was published in 1965. The first part of that edition was revised and re-published in 1975 and again in 1981. The present two-part set represents the eagerly awaited full revision by the author of his seminal work, now published as Parts I and II. Professor Christian was one of the founding fathers of materials science and highly respected worldwide. The new edition of his book deserves a place on the bookshelf of every materials science and engineering department. Suitable thermal and mechanical treatments will produce extensive rearrangements of the atoms in metals and alloys, and corresponding marked variations in physical and chemical properties. This book describes how such changes in the atomic configuration are effected, and discusses the associated kinetic and crystallographic features. It deals with areas such as lattice geometry, point defects, dislocations, stacking faults, grain and interphase boundaries, solid solutions, diffusion, etc. The first part covers the general theory while the second part is concerned with descriptions of specific types of transformations.