Download or read book Molecular Relaxation and Critical Dynamics written by Nikos Theodorakopoulos and published by . This book was released on 1972 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dielectric Relaxation and Dynamics of Polar Molecules written by Vladimir I. Ga?duk and published by World Scientific. This book was released on 1999 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topics covered in this book provide a qualitative and sometimes quantitative classic description of the wide-band 0-THz dielectric spectra of polar liquids, molecular libration-rotation (which is the reason for dielectric loss and absorption of electromagnetic waves), simple molecular models differing by the intermolecular-potential profiles, and present a comparison between the theoretical and experimental dependencies and derivation of the main results. A new feature is the application of a number of analytical models to different substances, including strongly absorbing nonassociating liquids, liquid water, water bound by macromolecules, and gas-like liquids. The presentation of the theory in this book is also new. It is based on the dynamic method in which the Brownian reorientations are considered implicitly, without direct solution of stochastic equations. This approach simplifies the theory. Senior students and experimentalists will find many of the results valuable.
Download or read book Molecular Relaxation Studies in Liquid Critical Systems and in Dilute Solutions written by Janis Leilani Dote and published by . This book was released on 1981 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of Molecular Systems written by R. Daudel and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the first of a set of two which contain the invited lectures given at the international seminar of the same title held at the Centre de Mecanique Ondulatoire Appliquee du Centre National de la Recherche Scientifique in Paris (France) from October 1983 to May 1985. They are intended to provide a survey of topics of current interest relative to the structure and the dynamics of molecular systems. The papers have been selected on the basis of their relevance to the following four topics: i) molecular conformations and transformations; ii) molecular relaxation and motion; iii) charge, spin and momentum distributions in molecular solids; iv) collective phenomena in condensed matter. The first volume deals f)1ostly with the first two topics, the second volume mostly with the last two. Each volume consists of about fifteen self contained, reference contributions covering recent achievements in active branches of molecular physics and physical chemistry. The first four papers of the present volume deal with theoretical aspects of structure and reactivity problems, with particular attention being paid to topology considerations, which have joined symmetry con siderations as an important tool in approaching chemistry problems. The treatment of nuclear probability density distributions is performed on a model basis for a simple system, even though it has come to the attention of theoreticians through experimental results for complex systems.
Download or read book Relaxation and Diffusion in Complex Systems written by K.L. Ngai and published by Springer Science & Business Media. This book was released on 2011-03-25 with total page 853 pages. Available in PDF, EPUB and Kindle. Book excerpt: The usefulness of the book to the reader is exposure to many different classes of materials and relaxation phenomena. They are tied together by the universal relaxation and diffusion properties they share, and a consistent explanation of their origin. The readers can apply what they learn to solve their own problems and use it as a stepping-stone to make further advances in theoretical understanding of the origin of the universality.
Download or read book Molecular Relaxation in Liquids written by Biman Bagchi and published by Oxford University Press. This book was released on 2012-01-30 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together many different relaxation phenomena in liquids under a common umbrella and provides a unified view of apparently diverse phenomena. It aligns recent experimental results obtained with modern techniques with recent theoretical developments. Such close interaction between experiment and theory in this area goes back to the works of Einstein, Smoluchowski, Kramers' and de Gennes. Development of ultrafast laser spectroscopy recently allowed study of various relaxation processes directly in the time domain, with time scales going down to picosecond (ps) and femtosecond (fs) time scales. This was a remarkable advance because many of the fundamental chemical processes occur precisely in this range and was inaccessible before the 1980s. Since then, an enormous wealth of information has been generated by many groups around the world, who have discovered many interesting phenomena that has fueled further growth in this field. As emphasized throughout the book, the seemingly different phenomena studied in this area are often closely related at a fundamental level. Biman Bagchi explains why relatively small although fairly sophisticated theoretical tools have been successful in explaining a wealth of experimental data at a semi-phenomenological level.
Download or read book Relaxation Dynamics in Molecular Glass formers with Systematic Structure Modifications written by and published by . This book was released on 2014 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications written by United States. National Bureau of Standards and published by . This book was released on 1969 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Dynamics And Relaxation Process written by N P Singh and published by . This book was released on 1999 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NBS Special Publication written by and published by . This book was released on 1978 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Molecular Collisions written by W. Miller and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: Activity in any theoretical area is usually stimulated by new experimental techniques and the resulting opportunity of measuring phenomena that were previously inaccessible. Such has been the case in the area under consideration he re beginning about fifteen years aga when the possibility of studying chemical reactions in crossed molecular beams captured the imagination of physical chemists, for one could imagine investigating chemical kinetics at the same level of molecular detail that had previously been possible only in spectroscopic investigations of molecular stucture. This created an interest among chemists in scattering theory, the molecular level description of a bimolecular collision process. Many other new and also powerful experimental techniques have evolved to supplement the molecular be am method, and the resulting wealth of new information about chemical dynamics has generated the present intense activity in molecular collision theory. During the early years when chemists were first becoming acquainted with scattering theory, it was mainly a matter of reading the physics literature because scattering experiments have long been the staple of that field. It was natural to apply the approximations and models that had been developed for nuclear and elementary particle physics, and although some of them were useful in describing molecular collision phenomena, many were not.
Download or read book Encyclopedia of Glass Science Technology History and Culture Two Volume Set written by Pascal Richet and published by John Wiley & Sons. This book was released on 2021-02-05 with total page 1568 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Encyclopedia begins with an introduction summarizing itsscope and content. Glassmaking; Structure of Glass, GlassPhysics,Transport Properties, Chemistry of Glass, Glass and Light,Inorganic Glass Families, Organic Glasses, Glass and theEnvironment, Historical and Economical Aspect of Glassmaking,History of Glass, Glass and Art, and outlinepossible newdevelopments and uses as presented by the best known people in thefield (C.A. Angell, for example). Sections and chapters arearranged in a logical order to ensure overall consistency and avoiduseless repetitions. All sections are introduced by a briefintroduction and attractive illustration. Newly investigatedtopics will be addresses, with the goal of ensuring that thisEncyclopedia remains a reference work for years to come.
Download or read book Thermodynamics written by Juan Carlos Moreno Piraján and published by BoD – Books on Demand. This book was released on 2011-10-10 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermodynamics is one of the most exciting branches of physical chemistry which has greatly contributed to the modern science. Being concentrated on a wide range of applications of thermodynamics, this book gathers a series of contributions by the finest scientists in the world, gathered in an orderly manner. It can be used in post-graduate courses for students and as a reference book, as it is written in a language pleasing to the reader. It can also serve as a reference material for researchers to whom the thermodynamics is one of the area of interest.
Download or read book NMR MRI SR and M ssbauer Spectroscopies in Molecular Magnets written by Pietro Carretta and published by Springer Science & Business Media. This book was released on 2007-12-15 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book an extensive overview on the results obtained during the last decade and on recent achievements in the study of molecular magnets by means of Nuclear Magnetic Resonance, Muon Spin Rotation, Magnetic Resonance Imaging and Mossbauer techniques is presented. The aim is to introduce the reader to these techniques and to give a general background on their application to molecular spin systems.
Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1970 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Dynamics in Dilute Media written by Shikha Somani and published by Stanford University. This book was released on 2011 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers undergo a sharp coil to stretch conformational transition in extension dominated flows when the strain rate exceeds a critical value. Dramatic change in flow behavior is known to occur at the coil-stretch transition, making it useful for several commercial applications. Despite decades of study, this phenomenon remains surrounded with controversy as the effect of solvent properties and fluid flow elements on this transition is not fully understood. In this work, we present a study of the coil-stretch transition and related hysteresis phenomenon using stochastic computer simulations. We first investigate the effect of solvent quality on the coil-stretch transition using Brownian dynamics simulations. Unlike experiments, which are plagued with problems related to polydispersity of polymers and inaccurate control over flow profiles, simulations offer a powerful platform to systematically study the effect of solvent quality while keeping all other parameters in the system constant. The system consists of a polymer subjected to planar elongational flow in both theta solvents and good solvents. The polymer is represented by a bead-spring chain model undergoing elongational flow. Solvent-mediated effects such as fluctuating hydrodynamic interactions (HI) and excluded volume (EV) are included rigorously. Conformational hysteresis is understood in terms of a 1-D energy landscape theory with an activation energy barrier for transition. At steady state, depending upon the flow rate, the energy landscape can either have one or two energy wells. An energy landscape with one well corresponds to the coiled state at low flow rate and stretched state at high flowrate. The double welled landscape corresponds to the hysteretic regime where both coiled and stretched conformational states coexist across the ensemble population. A key factor in determining the effect of solvent quality is the use of a proper measure of solvent quality. In almost all earlier studies, the effect of molecular weight on solvent quality has been neglected, producing inconsistent results. Here, the solvent quality is quantified carefully such that the effect of molecular weight and temperature is taken into account. Contrary to earlier findings, it is observed that with improvement in solvent quality, the chains unravel faster and the critical strain rate at which the coil to stretch transition takes place decreases. Furthermore, the solvent quality has a profound effect on the scaling of the critical strain rate with molecular weight and on both the transient and steady state properties of the system. Universal functions are shown to exist for the observed dynamic and static properties, which will prove useful in determining the operating parameters for experiments. In particular, the ratio of the two different relaxation times (longest relaxation time and zero shear rate viscosity) is found to be a universal function of solvent quality independent of molecular weight. The relaxation times (both the longest relaxation time and the zero shear rate viscosity) increase while the critical strain rate is found to decrease with solvent quality. Next, the study of conformational hysteresis is extended to more complicated 3-D flows to understand the effect of flow vorticity on this phenomenon. Heretofore, there has been no systematic methodology for studying the dynamical interactions between polymer molecules and elementary flow patterns in three-dimensional flows. Such a framework is essential not just for gaining valuable insights into the physics of complex fluids at a fundamental level, but it is also crucial for various important applications like turbulent drag reduction where the underlying physical mechanisms involve dynamical interactions between polymers and turbulence fine scale flow features. Such a study is presented here to provide a framework to interpret complex fluid phenomenon in terms of elementary flow patterns. We investigate the conformational hysteresis using rigorous Brownian dynamics simulations and specifically explore the effect of flow vorticity on the lifetime and width of the hysteresis window in 3-D flows. A systematic procedure is developed with careful eigenvalue analysis to explore the sole effect of vorticity on polymer dynamics keeping the principal strain rate fixed. It is observed that the hysteresis width shrinks due to increase in flow vorticity irrespective of the flow type (bi-extensional, bi-compressional, spiral-inwards, spiral-outwards etc). This is further traced to the alignment of eigenvectors with the principal eigenvector direction leading to enhanced fluctuations. Vorticity is found to have a significant effect on both the transient and the steady state properties. Understanding the effect of vorticity on polymer conformational hysteresis can further help in understanding the fundamental processes in complex flows.
Download or read book Publications of the National Bureau of Standards written by United States. National Bureau of Standards and published by . This book was released on 1968 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
