Download or read book Dispersive Kinetics written by Andrzej Plonka and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamical processes in which many timescales coexist are called dispersive. The rate coefficients for dispersive processes depend on time. In the case of a chemical reaction, the time dependence of the rate coefficient, k(t), termed the specific reaction rate, is rationalized in the following way. Reactions by their very nature have to disturb reactivity distributions of the reactants in condensed media, as the more reactive species are the first ones to disappear from the system. The extent of this disturbance depends on the ratio of the rates of reactions to the rate of internal rearrangements (mixing) in the system restoring the initial distribution in reactivity of reactants. If the rates of chemical reactions exceed the rates of internal rearrangements, then the initial distributions in reactant reactivity are not preserved during the course of reactions and the specific reaction rates depend on time. Otherwise the extent of disturbance is negligible and classical kinetics, with a constant specific reaction rate, k, termed the reaction rate constant, may be valid as an approximation. In condensed media dispersive dynamical processes are endemic and this is the first monograph devoted to these processes.
Download or read book Matrix Isolation Dispersive Kinetics and AB Initio Calculations on Organometallic Intermediates written by Carl Richard Kemnitz and published by . This book was released on 1995 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Photosynthetic Bacterial Reaction Center II written by Jacques Breton and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NATO Advanced Research Workshop entitled "The Photosynthetic Bacterial Reaction Center: Structure, Spectroscopy, and Dynamics" was held May 10-15, 1992, in the Maison d'H6tes of the Centre d'Etudes Nuc1eaires de Cadarache near Aix-en-Provence in the south of France. This workshop is the most recent of a string of meetings which started in Feldafing (Germany) in March 1985, soon after the three-dimensional structure of the bacterial reaction center had been elucidated by X-ray crystallography. This was followed, in September 1987, by a workshop in Cadarache and, in March 1990, by a second meeting in Feldafing. Although one of the most important processes on Earth, photosynthesis is still poorly understood. Stimulated by the breakthrough of solving the bacterial reaction center structure at atomic resolution, the field of relating this structure to the function of the reaction center, i. e. the remarkably efficient conversion and storage of solar energy, has been developing vigorously. Once the general organization of the cofactors and some details of the protein-cofactor interactions were known, it became possible to combine a variety of spectroscopic techniques with the powerful tool of site-directed mutagenesis in order to address increasingly incisive questions about the specific role of some amino acid residues in the electron transfer process. Still another promising tool is being developed, namely the exchange of a number of the native bacteriochlorophyll and bacteriopheophytin cofactors by chemically modified pigments.
Download or read book Tunnelling in Molecules written by Johannes Kästner and published by Royal Society of Chemistry. This book was released on 2020-09-30 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear Quantum Effects from Bio to Physical Chemistry
Download or read book Fractional Kinetics in Solids written by Vladimir Vasilʹevich Uchaĭkin and published by World Scientific. This book was released on 2013 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: The standard (Markovian) transport model based on the Boltzmann equation cannot describe some non-equilibrium processes called anomalous that take place in many disordered solids. Causes of anomality lie in non-uniformly scaled (fractal) spatial heterogeneities, in which particle trajectories take cluster form. Furthermore, particles can be located in some domains of small sizes (traps) for a long time. Estimations show that path length and waiting time distributions are often characterized by heavy tails of the power law type. This behavior allows the introduction of time and space derivatives of fractional orders. Distinction of path length distribution from exponential is interpreted as a consequence of media fractality, and analogous property of waiting time distribution as a presence of memory. In this book, a novel approach using equations with derivatives of fractional orders is applied to describe anomalous transport and relaxation in disordered semiconductors, dielectrics and quantum dot systems. A relationship between the self-similarity of transport, the Levy stable limiting distributions and the kinetic equations with fractional derivatives is established. It is shown that unlike the well-known Scher Montroll and Arkhipov Rudenko models, which are in a sense alternatives to the normal transport model, fractional differential equations provide a unified mathematical framework for describing normal and dispersive transport. The fractional differential formalism allows the equations of bipolar transport to be written down and transport in distributed dispersion systems to be described. The relationship between fractional transport equations and the generalized limit theorem reveals the probabilistic aspects of the phenomenon in which a dispersive to Gaussian transport transition occurs in a time-of-flight experiment as the applied voltage is decreased and/or the sample thickness increased. Recent experiments devoted to studies of transport in quantum dot arrays are discussed in the framework of dispersive transport models. The memory phenomena in systems under consideration are discussed in the analysis of fractional equations. It is shown that the approach based on the anomalous transport models and the fractional kinetic equations may be very useful in some problems that involve nano-sized systems. These are photon counting statistics of blinking single quantum dot fluorescence, relaxation of current in colloidal quantum dot arrays, and some others.
Download or read book Photosynthetic Reaction Center written by Johann Deisenhofer and published by Academic Press. This book was released on 2013-10-22 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: The availability of the photosynthetic reaction center's structure at an atomic resolution of less than three angstroms has revolutionized research. This protein is the first integral membrane protein whose structure has been determined with such precision. Each volume of the Photosynthetic Reaction Center contains original research, methods, and reviews. Together, these volumes cover our current understanding of how photosynthesis converts light energy into stored chemical energy. Volume II details the electron transfer process; it is oriented to the physical aspects of photosynthesis. It thus primarily discusses bacterial photosynthesis and model compounds. Volume II features the very complex and rapidly evolving issues associated with the theory of electron transfer in the bacterial reaction center, and explores picosecond and femtosecond spectroscopy. This volume also covers holeburning spectroscopy; primary events of bacterial photosynthesis with emphasis on the application of large, external electric fields designed to manipulate and probe mechanisms of the initial chemistry; the role of accessory carotenoid pigments; the techniques of infrared spectroscopy and magnetic resonance as applied to photosynthesis; and the interplay between natural and artificial photosynthesis.
Download or read book Liquid Chromatography written by Salvatore Fanali and published by Elsevier. This book was released on 2023-04-20 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid Chromatography: Fundamentals and Instrumentation, Third Edition offers a single source of authoritative information on all aspects of the practice of modern liquid chromatography. The book gives those working in academia and industry the opportunity to learn, refresh, and deepen their understanding of the field by covering basic and advanced theoretical concepts, recognition mechanisms, conventional and advanced instrumentation, method development, data analysis, and more. This third edition addresses new developments in the field with updated chapters from expert researchers. The book is a valuable reference for research scientists, teachers, university students, industry professionals in research and development, and quality control managers. Emphasizes the integration of chromatographic methods and sample preparation Provides important data related to complex matrices, sample preparation, and data handling Gives background information to facilitate the choice of LC sub-technique and experimental conditions, mobile and stationary phases, detectors, data processing, and more Offers comprehensive updates to all chapters Includes new chapters on chiral recognition, co-solvents and mobile phase additives, physicochemical measurements, and identification and quantitation in mass spectrometry
Download or read book Photophysics of Molecular Materials written by Guglielmo Lanzani and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon based pi-conjugated materials offer a broad range of applications, going from molecular electronics and single molecule devices to nanotechnology, plastic electronics and optoelectronics. The proper physical description of such materials is in between that of molecular solids and that of low-dimensional covalent semiconductors. This book is a comprehensive review of their elementary excitations processes and dynamics, which merges the two viewpoints, sometimes very different if not contrasting. In each chapter, a broad tutorial introduction provides a solid physical background to the topic, which is further discussed based on recent experimental results obtained via state-of-the-art techniques. Both the molecular, intra-chain character and the solid state, inter-molecular physics is addressed. Reports on single molecule and single polymer chain spectroscopy introduce the on-site phenomena. Several chapters are dedicated to nano-probes, steady state and transient spectroscopies. The highly ordered state, occurring in single crystals, is also discussed thoroughly. Finally, less conventional tools such as THz spectroscopy are discussed in detail. The book provides a useful introduction to the field for newcomers, and a valid reference for experienced researchers in the field.
Download or read book Advances in Multi Photon Processes and Spectroscopy written by S. H. Lin and published by World Scientific. This book was released on 2004 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: In view of the rapid growth in both experimental and theoretical studies of multiphoton processes and multiphoton spectroscopy of atoms, ions and molecules in chemistry, physics, biology, material sciences, etc., it is desirable to publish an Advanced Series that contains review papers readable not only by active researchers in these areas, but also by those who are not experts in the field but who intend to enter the field. The present series attempts to serve this purpose. Each review article is written in a self-contained manner by the experts in the area so that the readers can grasp the knowledge in the area without too much preparation. The topics covered in this volume include OC Ultrafast Photochemical Dynamics in Solution Studied by Femtosecond Time-Resolved Fluorescence Spectroscopy: Involvement of Highly Excited StatesOCO, OC Spectral Selective Studies of Molecular Doped Solids and ApplicationsOCO, OC From Multiphoton to Tunnel IonizationOCO, OC Cluster Dynamics in Intense Laser FieldsOCO, and OC Molecular Theory of Sum-Frequency Generation and its Application to Study Molecular ChiralityOCO. It is hoped that the collection of topics in this volume will be useful not only to active researchers but also to other scientists in biology, chemistry, materials science and physics. This book has been selected for coverage in: . OCo CC / Physical, Chemical & Earth Sciences. OCo Index to Scientific Book Contents- (ISBC). Contents: Ultrafast Photochemical Dynamics in Solution Studied by Femtosecond Time-Resolved Fluorescence Spectroscopy: Involvement of Highly Excited States (T Tahara); Spectral Selective Studies of Molecular Doped Solids and Applications (J-P Galaup); From Multiphoton to Tunnel Ionization (S L Chin); Cluster Dynamics in Intense Laser Fields (D Mathur); Molecular Theory of Sum-frequency Generations and Its Applications to Study Molecular Chirality (M Hayashi & S H Lin). Readership: Graduate students and researchers in chemistry, biology, materials science and physics."
Download or read book Fundamentals of Preparative and Nonlinear Chromatography written by Georges Guiochon and published by Elsevier. This book was released on 2006-02-10 with total page 991 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Preparative and Nonlinear Chromatography, Second Edition is devoted to the fundamentals of a new process of purification or extraction of chemicals or proteins widely used in the pharmaceutical industry and in preparative chromatography. This process permits the preparation of extremely pure compounds satisfying the requests of the US Food and Drug Administration. The book describes the fundamentals of thermodynamics, mass transfer kinetics, and flow through porous media that are relevant to chromatography. It presents the models used in chromatography and their solutions, discusses the applications made, describes the different processes used, their numerous applications, and the methods of optimization of the experimental conditions of this process.
Download or read book Selected Proceedings from the 231st ECS Meeting written by Alkire and published by The Electrochemical Society. This book was released on 2017-08-04 with total page 2056 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemistry written by Angelo Albini and published by Royal Society of Chemistry. This book was released on 2019-09-27 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drawing on the continued wealth of photochemical research, this volume combines reviews on the latest advances in the field with specific topical highlights. Starting with periodical reports of the recent literature on physical and inorganic aspects, light induced reactions in cryogenic matrices, properties of transition-metal compounds, time-resolved spectroscopy, the exploitation of solar energy and the molecules of colour. Coverage continues with highlighted topics, in the second part, from photoresponsive hydrogels, the tunable photoredox properties of organic dyes, light-driven asymmetric organocatalytic processes, dual gold–photoredox catalysis, the preparation and characterization of photosensitizers for triplet–triplet annihilation photon upconversion and the role of photochemistry on traditional synthetic processes. This volume will include for the first time a section entitled ‘SPR Lectures on Photochemistry’, providing examples for academic readers to introduce a photochemistry topic and precious help for students in photochemistry. Providing critical analysis of the topics, this book is essential reading for anyone wanting to keep up to date with the literature on photochemistry and its applications.
Download or read book XAFS Techniques for Catalysts Nanomaterials and Surfaces written by Yasuhiro Iwasawa and published by Springer. This book was released on 2016-10-19 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive, theoretical, practical, and thorough guide to XAFS spectroscopy. The book addresses XAFS fundamentals such as experiments, theory and data analysis, advanced XAFS methods such as operando XAFS, time-resolved XAFS, spatially resolved XAFS, total-reflection XAFS, high energy resolution XAFS, and practical applications to a variety of catalysts, nanomaterials and surfaces. This book is accessible to a broad audience in academia and industry, and will be a useful guide for researchers entering the subject and graduate students in a wide variety of disciplines.
Download or read book Theoretical Advancement in Chromatography and Related Separation Techniques written by Francesco Dondi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 651 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chromatography and all the related separation techniques are experimental in their origin and justification. However, the spectacular progress made in this area since World War II has given rise to a theoretical underpinning. The present book covers the current status of the research area and places it in perspective with the general concepts of the fields of physical chemistry involved. The ASI lectures/authors -- well known leaders in their fields -- have written presentations at the graduate level, accessible to all those who have a good general background in the thermodynamics and mass transfer theory of phase equilibria. The book will be useful to young scientists and engineers who wish to access the current frontiers in chromatography and other separation sciences.
Download or read book The Concept of Micellar Sponge Nanophases in Chemical Physics of Polymers written by Yuri Arsenovich Mikheev and published by CRC Press. This book was released on 2004-04-01 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monograph is intended for elucidation of the novel trend in chemical physics regarding the polymer non-crystalline phase. It stresses the physical phenomena affecting the kinetics and mechanism of chemical reactions proceeding in the non-crystalline polymer matrix (NCPM). NCPM is depicted in terms of a supramolecular (carcass-micellar) model. The model is thought to reflect heterophase packing of polymeric chains, which co-operate as a molecular-chain sponge. The NCPM model presented is proved for adequate description of principal structure-physical phenomena to elaborate the scheme of structural-kinetic modeling of chemical reactions in bulky polymers. Structure-physical phenomena elucidated in the monograph are: - peculiarities of polymer plasticization and polymer blending with liquids; - structural and thermodynamic aspects of sorption of low molecular species; - properties of ESR (spin) probes and optical (molecular) probes; - features of water absorbed by polymers; - mechanical and thermal effects generated by the molecular-chain sponge; - supramolecular aspects of NCPM chemical physics. This monograph includes the structural-kinetic modeling of complex polymer chemical reactions. It deals with the problem of mechanism and kinetics of free radical chain reactions using thermal and photochemical model reactions of dibenzoyl peroxide with glassy-like polymers (cellulose triacetate, polycarbonate, polystyrene, polyamide PA-548), viscoelastic polymers (atactic polypropylene, polyamide PA-548, polyethylene, polyisobutylene, melted poly(ethylene oxide), and isotactic polypropylene. In all cases, the supramolecular heterophase mechanism of the processes, which was unknown for homogeneous systems, was proved. Furthermore, heterophase mechanisms of photochemical reaction between naphthalene and cellulose triacetate and photolysis of poly(methyl methacrylate) proceeding as a photochain reaction are indicated.
Download or read book The Reaction Center of Photosynthetic Bacteria written by Maria-Elisabeth Michel-Beyerle and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of this third Feldafing Meeting can be considered as the harvest of novel techniques in spectroscopy, biochemistry and molecular biology to the bacterial photosynthetic reaction center. New information pertains to the crystallographic and electronic structure as well as to the dynamics of primary events and the role of the protein. The answer to one long-standing problem, the mechanism of primary charge separation, converges towards a sequential scheme, supported by femtosecond spectroscopy on reaction centers with selectively modified energetics.
Download or read book Annual Reports on the Progress of Chemistry written by and published by . This book was released on 2001 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
