Download or read book Electronic Dissipation Processes During Chemical Reactions on Surfaces written by Kevin Stella and published by disserta Verlag. This book was released on 2011 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every day in our life is larded with a huge number of chemical reactions on surfaces. Some reactions occur immediately, for others an activation energy has to be supplied. Thus it happens that though a reaction should thermodynamically run off, it is kinetically hindered. Meaning the partners react only to the thermodynamically more stable product state within a mentionable time if the activation energy of the reaction is supplied. With the help of catalysts the activation energy of a reaction can be lowered. Such catalytic processes on surfaces are widely used in industry. Around 90% of chemicals are produced via a heterogeneously catalyzed process where a reaction occurs on the surface of a catalyst. However, why is it generally possible that such reactions run off with the help of heterogeneous catalysis, meaning with lower activation energy than without presence of a catalyst? What happens with the energy which is released during a reaction of gas particles on surfaces? How is this energy released, when some part of the energy is transferred to the reactant and some to the chemically active surface? Which physical mechanisms play a key role in the energy transfer? These questions are summarized in the concept of the energy dissipation. To observe this energy dissipation phenomenon, we use a new method, the chemoelectronics. With this method we try to detect the released energy, induced by reactions on surfaces, via thin-layered electronic device elements. An aim of this work is to build up very sensitive chemoelectronic sensors to measure electronic excitations released during such simple reactions of molecules as adsorption and desorption and more complicated reactions as the water formation reaction. Therefore a new line of chemoelectronic sensors is developed and characterized in terms of internal photoemission and stability. Meaning the previously used aluminum (Al-AlOx-Ag) and tantalum based (Ta-TaOx-Au) metal-insulator-metal sensors (MIM) are tested and new titanium based (Ti-TiOx-Au) MIMs are developed. Additionally silicon based stepped-metal-insulator-semiconductor sensors (stepped-MIS, Si-SiOx-Au, Si-SiOx-Pt) are set up and characterized. For the characterization of the chemoelectronic sensors the process of internal photoemission is used. Both, chemical- and photoexcitation release hot charge carriers (electrons and holes). Due to the existence of excited carriers in the sensor, a current can be measured without applying a bias voltage. It will be shown that the chemo- and the photosensitivity are strongly related to each other. As a first experiment for the chemical selectivity of the detectors, a stream of excited hydrogen molecules and hydrogen atoms is used. The excitation and radical formation is produced by the interaction of ground state molecules with a hot tungsten surface according to the pioneering experiments of Irving Langmuir. Additionally, excited oxygen beams are studied in this work.
Download or read book Current Trends of Surface Science and Catalysis written by Jeong Young Park and published by Springer Science & Business Media. This book was released on 2013-10-23 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book covers the latest surface science studies on model catalysts, including single crystals, non-colloidal nanocatalysts, and nanoparticles in various forms with the control of size, shape and composition. This book addresses the issue of bridging “materials and pressure gaps” and also discusses the important issue of metal-oxide interface and hot electron flows in heterogeneous catalysis. The current development of in-situ surface techniques that is relevant to bridging “pressure gaps” is also highlighted.
Download or read book Encyclopedia of Interfacial Chemistry written by and published by Elsevier. This book was released on 2018-03-29 with total page 5276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry, Seven Volume Set summarizes current, fundamental knowledge of interfacial chemistry, bringing readers the latest developments in the field. As the chemical and physical properties and processes at solid and liquid interfaces are the scientific basis of so many technologies which enhance our lives and create new opportunities, its important to highlight how these technologies enable the design and optimization of functional materials for heterogeneous and electro-catalysts in food production, pollution control, energy conversion and storage, medical applications requiring biocompatibility, drug delivery, and more. This book provides an interdisciplinary view that lies at the intersection of these fields. Presents fundamental knowledge of interfacial chemistry, surface science and electrochemistry and provides cutting-edge research from academics and practitioners across various fields and global regions
Download or read book Electronic Processes at Solid Surfaces written by E. Ilisca and published by World Scientific. This book was released on 1996 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of surface physics has now grown to become an exciting interdisciplinary field of research with important practical applications.The purpose of this book is to provide a guided tour of some recent advances, key research issues and approaches in electronic processes at solid surfaces.Apart from a few structural studies, selected topics have been chosen to illustrate the dynamical response of the solid surface to external probes, with the main emphasis on electron transfer phenomena.
Download or read book Journal of Research of the National Institute of Standards and Technology written by and published by . This book was released on 1991 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reports NIST research and development in the physical and engineering sciences in which the Institute is active. These include physics, chemistry, engineering, mathematics, and computer sciences. Emphasis on measurement methodology and the basic technology underlying standardization.
Download or read book Dynamics written by and published by Elsevier. This book was released on 2008-10-09 with total page 1037 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of the Handbook of Surface Science covers all aspects of the dynamics of surface processes. Two dozen world leading experts in this field address the subjects of energy exchange in gas atoms, surface collisions, the rules governing dissociative adsorption on surfaces, the formation of nanostructures on surfaces by self-assembly, and the study of surface phenomena using ultra-fast lasers. The chapters are written for both newcomers to the field as well as researchers.• Covers all aspects of the dynamics of surface processes • Provides understanding of this unique field utilizing a multitude of accurate experiments and advanced microscopic theory that allows quantum-level comparisons • Presents the concepts and tools relevant beyond surface science for catalysis, nanotechnology, biology, medicine, and materials
Download or read book Dynamics at Surfaces Understanding Energy Dissipation and Physicochemical Processes at the Atomic and Molecular Level written by Marco Sacchi and published by Frontiers Media SA. This book was released on 2024-04-26 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy release to solid interfaces following chemical reactions is ubiquitous in a vast range of phenomena. Energy dissipation and dynamical disorder (surface entropy), surface friction and molecular diffusion control the rates of heterogeneous catalytic reactions, the efficiency of novel technology, lubrication as well as materials growth including self-assembly and nano-structures. Yet we understand little about the underlying nature of these mechanisms. Fundamentally, energy dissipation including interactions with phonons and electron-hole pairs determines the lifetime of molecular vibrations and rotations as well as the decoherence rate of quantum states. These processes form a central point for many aspects in physical chemistry, are embedded in the mechanisms that control surface dynamical processes and are critical factors in catalysis. They are equally relevant for physicochemical processes in the Earth's atmosphere and astrochemistry occurring on cosmic dust grains.
Download or read book Frontiers and Challenges in Warm Dense Matter written by Frank Graziani and published by Springer Science & Business. This book was released on 2014-04-28 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm Dense Matter (WDM) occupies a loosely defined region of phase space intermediate between solid, liquid, gas, and plasma, and typically shares characteristics of two or more of these phases. WDM is generally associated with the combination of strongly coupled ions and moderately degenerate electrons, and careful attention to quantum physics and electronic structure is essential. The lack of a small perturbation parameter greatly limits approximate attempts at its accurate description. Since WDM resides at the intersection of solid state and high energy density physics, many high energy density physics (HEDP) experiments pass through this difficult region of phase space. Thus, understanding and modeling WDM is key to the success of experiments on diverse facilities. These include the National Ignition Campaign centered on the National Ignition Facility (NIF), pulsed-power driven experiments on the Z machine, ion-beam-driven WDM experiments on the NDCX-II, and fundamental WDM research at the Linear Coherent Light Source (LCLS). Warm Dense Matter is also ubiquitous in planetary science and astrophysics, particularly with respect to unresolved questions concerning the structure and age of the gas giants, the nature of exosolar planets, and the cosmochronology of white dwarf stars. In this book we explore established and promising approaches to the modeling of WDM, foundational issues concerning the correct theoretical description of WDM, and the challenging practical issues of numerically modeling strongly coupled systems with many degrees of freedom.
Download or read book Vibrations at Surfaces written by R. Caudano and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains most of the invited and contributed papers presented at the second international conference devoted to the general topic "Vibrations at Surfaces" and which took place from 10 to 12 September 1980 at the Facu1tes Notre-Dame de 1a Paix in Namur, Belgium. The conference was organized to review the large amount of information gathered in this field over the late seventies as a result of th~ rapid improvements and dissemination of surface spectroscopic technique such a electron energy loss, infrared and Raman surface spectroscopies. Much time was devoted to Raman spectroscopy of adsorbed mo1e 'cu1es. After several years of vivid debate over the causes of the observed large enhancement of Raman cross section, a clearer pic ture emerges from the papers presented here: the actual value of the enhancement factor does depend in a complicated manner on long range surface roughness, atomic-scale roughness and the dielectric properties of the substrate as well as on the electronic structure of the molecule in its adsorbed state. Less controversial are the results obtained with electron energy loss spectroscopy (EELS) and several sessions of the con ference were devoted to the approach. As witnessed by the growing number of laboratories using the technique, EELS is now a mature spectroscopic tool for the characterization and analysis of the chemisorption bond.
Download or read book Radiation Chemical Processes in Solid Phase written by Evginiy I. Grigoriev and published by CRC Press. This book was released on 1996-11-14 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unlike many other references, Radiation-Chemical Processes in Solid Phase analyzes experimental data on radiolysis in terms of solid-state physics. It traces the effect exerted by media from primary processes of radiation-substance interaction to final products. The authors consider the main chemically active elementary excitations arising under irradiation of solids and discuss the mechanisms of chemical reactions induced by them. They present the general principles of solid-state and molecular physics, and cover numerous radiation-chemical processes.
Download or read book Modern Aspects of Electrochemistry written by Ralph E. White and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of Modern Aspects contains seven chapters. The major topics covered in the first six chapters of this volume include fundamentals of solid state electrochemistry; kinetics of electrochemical hydrogen entry into metals and alloys; oxidation of organics; fuel cells; electrode kinetics of trace-anion catalysis; nano structural analysis. The last chapter is a corrected version of chapter four from Volume 35. Faisal M. AI-faqeer and Howard W. Pickering begin the first chapter by going back to 1864 and Cailletet who found that some hydrogen evolved and was absorbed by iron when it was immersed in dilute sulfuric acid. The absorption of hydrogen into metals and alloys can lead to catastrophic failures of structures. They discuss the kinetics of electrochemical hydrogen entry into metals and alloys. In chapter three, Clyde L. Briant reviews the electrochemistry, corrosion and hydrogen embrittlement of unalloyed titanium. He begins by reviewing the basic electrochemistry and general corrosion of titanium. He also discusses pitting and galvanostatic corrosion followed by a review of hydrogen embrittlement emphasizing the formation of hydrides and the effect of these on titanium's mechanical properties. Christos Comninellis and Gy6rgy F6ti discuss the oxidative electrochemical processes of organics in chapter three. They begin by defining direct and indirect electrochemical oxidation of organics. They introduce a model that allows them to distinguish between active (strong) and non-active (weak) anodes. Different classes of organic compounds are used for kinetic models of organic oxidation at active and non-active type anodes.
Download or read book Simulation and Analysis of Mathematical Methods in Real Time Engineering Applications written by T. Ananth Kumar and published by John Wiley & Sons. This book was released on 2021-08-16 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: SIMULATIONS AND ANALYSIS of Mathematical Methods Written and edited by a group of international experts in the field, this exciting new volume covers the state of the art of real-time applications of computer science using mathematics. This breakthrough edited volume highlights the security, privacy, artificial intelligence, and practical approaches needed by engineers and scientists in all fields of science and technology. It highlights the current research, which is intended to advance not only mathematics but all areas of science, research, and development, and where these disciplines intersect. As the book is focused on emerging concepts in machine learning and artificial intelligence algorithmic approaches and soft computing techniques, it is an invaluable tool for researchers, academicians, data scientists, and technology developers. The newest and most comprehensive volume in the area of mathematical methods for use in real-time engineering, this groundbreaking new work is a must-have for any engineer or scientist’s library. Also useful as a textbook for the student, it is a valuable contribution to the advancement of the science, both a working handbook for the new hire or student, and a reference for the veteran engineer.
Download or read book Postdoctoral Research Associateships written by and published by . This book was released on 1980 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Biomaterials II written by Kevin Healy and published by Elsevier. This book was released on 2017-05-18 with total page 4865 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Biomaterials II, Second Edition, Seven Volume Set brings together the myriad facets of biomaterials into one expertly-written series of edited volumes. Articles address the current status of nearly all biomaterials in the field, their strengths and weaknesses, their future prospects, appropriate analytical methods and testing, device applications and performance, emerging candidate materials as competitors and disruptive technologies, research and development, regulatory management, commercial aspects, and applications, including medical applications. Detailed coverage is given to both new and emerging areas and the latest research in more traditional areas of the field. Particular attention is given to those areas in which major recent developments have taken place. This new edition, with 75% new or updated articles, will provide biomedical scientists in industry, government, academia, and research organizations with an accurate perspective on the field in a manner that is both accessible and thorough. Reviews the current status of nearly all biomaterials in the field by analyzing their strengths and weaknesses, performance, and future prospects Covers all significant emerging technologies in areas such as 3D printing of tissues, organs and scaffolds, cell encapsulation; multimodal delivery, cancer/vaccine - biomaterial applications, neural interface understanding, materials used for in situ imaging, and infection prevention and treatment Effectively describes the many modern aspects of biomaterials from basic science, to clinical applications
Download or read book Nanofabrication Handbook written by Stefano Cabrini and published by CRC Press. This book was released on 2012-02-24 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: While many books are dedicated to individual aspects of nanofabrication, there is no single source that defines and explains the total vision of the field. Filling this gap, Nanofabrication Handbook presents a unique collection of new and the most important established approaches to nanofabrication. Contributors from leading research facilities and
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Electronic Surface And Interface States On Metallic Systems Proceedings Of The We heraeus Seminar written by M Donath and published by World Scientific. This book was released on 1995-09-26 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an in-depth understanding of the nature of surface states and, in particular, their relevance to the physics and chemistry of metallic surfaces. Recent experiments reveal that surface states play a key role in a wide variety of surface phenomena. Individual chapters examine the contribution of surface states to reconstruction, non-adiabatic vibrational damping, nonlinear optical response, tunneling, interaction potentials for scattering and physisorption, as well as surface and thin-film magnetism. Altogether they provide an overview of this rapidly developing field.
