Download or read book Computational Studies of the Effects of Pressure on Reaction Kinetics and Reaction Mechanisms written by Jacob Alan Spooner and published by . This book was released on 2017 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both experiment and first principles calculations unequivocally indicate that properties of elements and their compounds undergo a tremendous transformation at ultra-high pressures due to the fact that the difference between intra- and intermolecular interactions disappears under such conditions. Yet, even at much milder pressures, when molecules still retain their individual identity, their chemical properties and reactivity change dramatically. We propose a set of techniques, based on molecular dynamics simulations and quantum mechanical calculations, which can aid in the understanding and prediction of the behavior of chemical systems over a wide range of high pressures.Experimentally, the effects of pressure on reaction rates and equilibrium constants are described by their pressure derivatives, known as volumes of activation and reaction volumes respectively. These quantities are directly linked to partial molar volumes of reactants, transition states, and products. We formulate a molecular dynamics method for the accurate calculation of molecular volumes. This method can be applied to both stable and transient species, which makes it suitable for quantitative analysis of experimental volumes of activation and reaction volumes. The calculated partial molar volumes, as well as reaction and activation volumes obtained from them, agree well with experimental data. To assess the reliability of the experimental activation and reaction volumes, we also present an analysis of the most common empirical analytical functions used to obtain them from pressure dependences of the rate and equilibrium constants. Since mechanisms of chemical reactions are often described in terms of properties of their potential energy surfaces (PES) or Gibbs energy surfaces (GES), we present an analysis of pressure-induced deformations of GES of solvated reaction systems and use quantum mechanical and molecular dynamics simulations to construct energy surfaces and reaction profiles of compressed species, and to analyze how their shapes and topography change in response to compression. We also discuss the important role of volume profiles in assessing pressure-induced deformations of GES.
Download or read book Atmospheric Reaction Chemistry written by Hajime Akimoto and published by Springer. This book was released on 2016-03-04 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is aimed at graduate students and research scientists interested in gaining a deeper understanding of atmospheric chemistry, fundamental photochemistry, and gas phase and heterogeneous reaction kinetics. It also provides all necessary spectroscopic and kinetic data, which should be useful as reference sources for research scientists in atmospheric chemistry. As an application of reaction chemistry, it provides chapters on tropospheric and stratospheric reaction chemistry, covering tropospheric ozone and photochemical oxidant formation, stratospheric ozone depletion and sulfur chemistry related to acid deposition and the stratospheric aerosol layer. This book is intended not only for students of chemistry but also particularly for non-chemistry students who are studying meteorology, radiation physics, engineering, and ecology/biology and who wish to find a useful source on reaction chemistry.
Download or read book A Computational Study of the Chemical Kinetics of Hydrogen Combustion written by T. L. Burks and published by . This book was released on 1981 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: A set of elementary reactions and their corresponding rate coefficients has been assembled to describe the homogeneous H2-O2 reaction system over the temperature range 300-3000 K. The reaction mechanism was drawn together assuming that H2-O2 reactive mixtures could be adequately described in terms of self-consistent, thermal distributions of electronically neutral, ground-state reactants, intermediates and products. The resulting time-dependent ordinary differential equations describing the system were integrated assuming various initial pressures, temperatures and initial concentrations of reactants and diluents. The computed results have been compared with experimentally observed induction times, second explosion limits, the rate of reaction above the second explosion limit and the temporal behavior of reaction species. The good agreement between the computational and experimental results attests to the accuracy of the assembled mechanism in its description of the homogeneous reaction system and supports the validity of the set of associated rate coefficients for the elementary reactions of the mechanism over a broad range of reaction conditions. (Author).
Download or read book Computational Studies on Complex Reaction Mechanisms written by Alicia C. Voukides and published by . This book was released on 2009 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reaction Rate Theory and Rare Events written by Baron Peters and published by Elsevier. This book was released on 2017-03-22 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reaction Rate Theory and Rare Events bridges the historical gap between these subjects because the increasingly multidisciplinary nature of scientific research often requires an understanding of both reaction rate theory and the theory of other rare events. The book discusses collision theory, transition state theory, RRKM theory, catalysis, diffusion limited kinetics, mean first passage times, Kramers theory, Grote-Hynes theory, transition path theory, non-adiabatic reactions, electron transfer, and topics from reaction network analysis. It is an essential reference for students, professors and scientists who use reaction rate theory or the theory of rare events. In addition, the book discusses transition state search algorithms, tunneling corrections, transmission coefficients, microkinetic models, kinetic Monte Carlo, transition path sampling, and importance sampling methods. The unified treatment in this book explains why chemical reactions and other rare events, while having many common theoretical foundations, often require very different computational modeling strategies. Offers an integrated approach to all simulation theories and reaction network analysis, a unique approach not found elsewhere Gives algorithms in pseudocode for using molecular simulation and computational chemistry methods in studies of rare events Uses graphics and explicit examples to explain concepts Includes problem sets developed and tested in a course range from pen-and-paper theoretical problems, to computational exercises
Download or read book Chemistry at Extreme Conditions written by M.R. Manaa and published by Elsevier. This book was released on 2005-03-02 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemistry at Extreme Conditions covers those chemical processes that occur in the pressure regime of 0.5–200 GPa and temperature range of 500–5000 K and includes such varied phenomena as comet collisions, synthesis of super-hard materials, detonation and combustion of energetic materials, and organic conversions in the interior of planets. The book provides an insight into this active and exciting field of research. Written by top researchers in the field, the book covers state of the art experimental advances in high-pressure technology, from shock physics to laser-heating techniques to study the nature of the chemical bond in transient processes. The chapters have been conventionally organised into four broad themes of applications: biological and bioinorganic systems; Experimental works on the transformations in small molecular systems; Theoretical methods and computational modeling of shock-compressed materials; and experimental and computational approaches in energetic materials research. * Extremely practical book containing up-to-date research in high-pressure science * Includes chapters on recent advances in computer modelling* Review articles can be used as reference guide
Download or read book Kinetics of Heterogeneous Catalytic Reactions written by Michel Boudart and published by Princeton University Press. This book was released on 2014-07-14 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.
Download or read book Chemical Kinetics and Reaction Dynamics written by Santosh K. Upadhyay and published by Springer Science & Business Media. This book was released on 2007-04-29 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical Kinetics and Reaction Dynamics brings together the major facts and theories relating to the rates with which chemical reactions occur from both the macroscopic and microscopic point of view. This book helps the reader achieve a thorough understanding of the principles of chemical kinetics and includes: Detailed stereochemical discussions of reaction steps Classical theory based calculations of state-to-state rate constants A collection of matters on kinetics of various special reactions such as micellar catalysis, phase transfer catalysis, inhibition processes, oscillatory reactions, solid-state reactions, and polymerization reactions at a single source. The growth of the chemical industry greatly depends on the application of chemical kinetics, catalysts and catalytic processes. This volume is therefore an invaluable resource for all academics, industrial researchers and students interested in kinetics, molecular reaction dynamics, and the mechanisms of chemical reactions.
Download or read book Modeling of Chemical Kinetics and Reactor Design written by A. Kayode Coker and published by Gulf Professional Publishing. This book was released on 2001-07-26 with total page 1132 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference conveys a basic understanding of chemical reactor design methodologies that incorporate both control and hazard analysis. It demonstrates how to select the best reactor for any particular chemical reaction, and how to estimate its size to determine the best operating conditions.
Download or read book Predictive Chemical Kinetics written by Joshua William Allen and published by . This book was released on 2013 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of petroleum-based fuels for transportation accounted for more than 25% of the total energy consumed in 2012, both in the United States and throughout the world. The finite nature of world oil reserves and the effects of burning petroleum-based fuels on the world's climate have motivated efforts to develop alternative, renewable fuels. A major category of alternative fuels is biofuels, which potentially include a wide variety of hydrocarbons, alcohols, aldehydes, ketones, ethers, esters, etc. To select the best species for use as fuel, we need to know if it burns cleanly, controllably, and efficiently. This is especially important when considering novel engine technologies, which are often very sensitive to fuel chemistry. The large number of candidate fuels and the high expense of experimental engine tests motivates the use of predictive theoretical methods to help quickly identify the most promising candidates. This thesis presents several contributions in the areas of predictive chemical kinetics and automatic mechanism generation, particularly in the area of reaction kinetics. First, the accuracy of several methods of automatic, high-throughput estimation of reaction rates are evaluated by comparison to a test set obtained from the NIST Chemical Kinetics Database. The methods considered, including the classic Evans-Polanyi correlation, the "rate rules" method currently used in the RMG software, and a new method based on group contribution theory, are shown to not yet obtain the order-of-magnitude accuracy desired for automatic mechanism generation. Second, a method of very accurate computation of bimolecular reaction rates using ring polymer molecular dynamics (RPMD) is presented. RPMD rate theory enables the incorporation of quantum effects (zero-point energy and tunneling) in reaction kinetics using classical molecular dynamics trajectories in an extended phase space. A general-purpose software package named RPMD-rate was developed for conducting such calculations, and the accuracy of this method was demonstrated by investigating the kinetics and kinetic isotope effect of the reaction OH + CH4 --> CH3 + H2O. Third, a general framework for incorporating pressure dependence in thermal unimolecular reactions, which require an inert third body to provide or remove the energy needed for reaction via bimolecular collisions, was developed. Within this framework, several methods of reducing the full, master equation-based model to a set of phenomenological rate coefficients k(T, P) are compared using the chemically-activated reaction of acetyl radical with oxygen as a case study, and recommendations are made as to when each method should be used. This also resulted in a general-purpose code for calculating pressure-dependent kinetics, which was applied to developing an ab initio model of the reaction of the Criegee biradical CH 200 with small carbonyls that reproduces recent experimental results. Finally, the ideas and techniques of estimating reaction kinetics are brought together for the development of a detailed kinetics model of the oxidation of diisopropyl ketone (DIPK), a candidate biofuel representative of species produced from cellulosic biomass conversion using endophytic fungi. The model is evaluated against three experiments covering a range of temperatures, pressures, and oxygen concentrations to show its strengths and weaknesses. Our ability to automatically generate this model and systematically improve its parameters without fitting to the experimental results demonstrates the validity and usefulness of the predictive chemical kinetics paradigm. These contributions are available as part of the Reaction Mechanism Generator (RMG) software package.
Download or read book A Brief Study of Computational Methods to Locate Reaction Mechanism written by Snehasis Banerjee and published by LAP Lambert Academic Publishing. This book was released on 2016-01-27 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with an outline of the theoretical/computational algorithms required to carry out a study of reaction mechanism in the framework of the transition state theory. Since the goal of computational study of kinetics and reaction mechanism are finding equilibrium geometries, transition states and reaction paths lie on a potential energy surface (PES) connecting reactants and products to the transition states, an overview of computational algorithms is required for the understanding of the theoretical tools remain behind. Thus, herein, the geometry optimization procedure of both for minima and first order saddle point has been addressed. Additionally, density functional theory (DFT) and Hartree-Fock (HF) methods have been discussed to predict the energy of chemical structures. Lastly, the function of basis set and the effect of solvation of the molecules has been explored.
Download or read book Practical Aspects of Computational Chemistry II written by Jerzy Leszczynski and published by Springer Science & Business Media. This book was released on 2012-07-09 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical Aspects of Computational Chemistry II: An Overview of the Last Two Decades and Current Trends gathers the discussion of advances made within the last 20 years by well-known experts in the area of theoretical and computational chemistry and physics. The title reflects the celebration of the twentieth anniversary of the “Conference on Current Trends in Computational Chemistry (CCTCC)” to success of which all authors contributed. Starting with the recent development of modeling of solvation effect using the Polarizable Continuum Model (PCM) at the Coupled-Cluster level and the effects of extreme pressure on the molecular properties within the PCM framework, this volume focuses on the association/dissociation of ion pairs in binary solvent mixtures, application of graph theory to determine the all possible structures and temperature-dependent distribution of water cluster, generalized-ensemble algorithms for the complex molecular simulation, QM/MD based investigation of formation of different nanostructures under nonequilibrium conditions, quantum mechanical study of chemical reactivity of carbon nanotube, covalent functionalization of single walled-carbon nanotube, designing of functional materials, importance of long-range dispersion interaction to study nanomaterials, recent advances in QSPR/QSAR analysis of nitrocompounds, prediction of physico-chemical properties of energetic materials, electronic structure and properties of 3d transition metal dimers, the s-bond activation reactions by transition metal complexes, theoretical modeling of environmental mercury depletion reaction, organolithium chemistry and computational modeling of low-energy electron induced DNA damage. Practical Aspects of Computational Chemistry II: An Overview of the Last Two Decades and Current Trends is aimed at theoretical and computational chemists, physical chemists, materials scientists, and particularly those who are eager to apply computational chemistry methods to problems of chemical and physical importance. This book provides valuable information to undergraduate, graduate, and PhD students as well as to established researchers. Practical Aspects of Computational Chemistry II: An Overview of the Last Two Decades and Current Trends is aimed at theoretical and computational chemists, physical chemists, materials scientists, and particularly those who are eager to apply computational chemistry methods to problems of chemical and physical importance. This book provides valuable information to undergraduate, graduate, and PhD students as well as to established researchers.
Download or read book Physical and Numerical Sources of Computational Inefficiency in Integration of Chemical Kinetic Rate Equations written by David T. Pratt and published by . This book was released on 1986 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Pressure Effects on Reaction Kinetics written by Robert Irving Rutherford and published by . This book was released on 1958 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Mechanisms of Reactions Influencing Atmospheric Ozone written by Jack George Calvert and published by . This book was released on 2015 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ozone, an important trace component, is critical to life on Earth and to atmospheric chemistry. The presence of ozone profoundly impacts the physical structure of the atmosphere and meteorology. Ozone is also an important photolytic source for HO radicals, the driving force for most of the chemistry that occurs in the lower atmosphere, is essential to shielding biota, and is the only molecule in the atmosphere that provides protection from UV radiation in the 250-300 nm region. However, recent concerns regarding environmental issues have inspired a need for a greater understanding of ozone, and the effects that it has on the Earth's atmosphere. The Mechanisms of Reactions Influencing Atmospheric Ozone provides an overview of the chemical processes associated with the formation and loss of ozone in the atmosphere, meeting the need for a greater body of knowledge regarding atmospheric chemistry. Renowned atmospheric researcher Jack Calvert and his coauthors discuss the various chemical and physical properties of the earth's atmosphere, the ways in which ozone is formed and destroyed, and the mechanisms of various ozone chemical reactions in the different spheres of the atmosphere. The volume is rich with valuable knowledge and useful descriptions, and will appeal to environmental scientists and engineers alike. A thorough analysis of the processes related to tropospheric ozone, The Mechanisms of Reactions Influencing Atmospheric Ozone is an essential resource for those hoping to combat the continuing and future environmental problems, particularly issues that require a deeper understanding of atmospheric chemistry.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pamphlets on Employment Minnesota written by and published by . This book was released on 1900 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
