Download or read book Kinetics of Criegee Intermediate Reactions with Nitric Acid Measured by UV Absorption Spectroscopy written by 楊絜甯 and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Spectroscopic and Kinetic Studies of the Simplest Criegee Intermediate written by Elizabeth Stack Foreman and published by . This book was released on 2017 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric chemistry is driven largely by free radical species whose reactions determine both the composition and oxidative capacity of the atmosphere. Carbonyl oxides, or Criegee Intermediates, formed in the ozonolysis of alkenes in the troposphere are highly reactive biradicals/zwitterions that are implicated in the production of secondary organic aerosol and particulate matter. This thesis will focus on the following aspects of the spectroscopy and kinetics related to the simplest Criegee Intermediate, formaldehyde oxide: (1) kinetics of IO radical formation from the CH2I + O2 reaction, (2) spectroscopy and dynamics of electronically excited states of CH 2OO, (3) the kinetics of reactions of CH2OO with trace atmospheric pollutants. The spectroscopic and kinetic study of IO radicals formed as minor products in the laboratory synthesis of Criegee Intermediates is performed using cavity ring-down spectroscopy (CRDS). We observe experimentally that IO radicals exhibit vibrational state specific formation kinetics and suggest that this is due to a product branching ratio controlled by the degree of internal excitation in the reactants. IO and CH2OO are produced simultaneously in the reaction of CH2I with O2 and exhibit overlapping absorption bands in the near-ultraviolet/visible. This poses a challenge for direct detection of CH2OO using a linear absorption technique. The measured rate constant for the formation of IO is used to deconvolute the total observed absorption spectrum into individual molecular components. Both CRDS and single-pass broadband transient absorption spectroscopy (BBTAS) are used to independently measure the absolute absorption cross sections for the second electronically excited state of CH2OO in the near-ultraviolet/visible. We show that the absorption spectra do not exhibit fine structure, even at the lowest excitation energies, and that the observed broad lineshapes cannot be attributed hot bands. This suggests that the photolysis quantum yield is “1 and the observed structure in the electronic absorption spectrum, that is absent from the action spectrum, is the result of relaxation via nonradiative population transfer to a long-lived state or fluorescence. BBTAS is subsequently used to probe the kinetics of the reactions of CH2OO with two inorganic acids: HCl and HNO3. We find that these reactions occur at or near the collision limit and that nitric acid in particular may be locally competitive with water vapor, which is widely accepted as the dominant sink for Criegee Intermediates in the atmosphere. Taken together these studies provide a deeper understanding of the role Criegee Intermediates play in tropospheric chemistry.
Download or read book Kinetic Studies of Small Criegee Intermediates by UV Absorption Spectroscopy written by 趙彣 and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2018 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2001 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theses on any subject submitted by the academic libraries in the UK and Ireland.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1983 with total page 1166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Water Photochemistry written by Paola Calza and published by Royal Society of Chemistry. This book was released on 2015-11-20 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Borne out of the current widespread interest in the pollution of water bodies, this book explores the latest research concerning the photochemical fate of organic pollutants in surface water. The main objective is to give insight into both the functioning of ecosystems and the behaviour of emerging pollutants in those ecosystems. Particular importance is dedicated to techniques that can be used in the field and in the laboratory for the detection of pollutants and of their transformation intermediates. The inclusion of photochemical processes that have not gained previous coverage will afford the reader novel insights, whilst the focus on modelling and transformation intermediates will ensure the title's relevance to academics, the chemical manufacturing industries and environmental assessment experts alike.
Download or read book Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the eleventh in a series of evaluated sets of rate constants and photochemical cross sections compiled by the NASA Panel for Data Evaluation. The primary application of the data is in the modeling of stratospheric processes, with special emphasis on the ozone layer and its possible perturbation by anthropogenic and natural phenomena. Demore, W. B. and Sander, S. P. and Golden, D. M. and Hampson, R. F. and Kurylo, M. J. and Howard, C. J. and Ravishankara, A. R. and Kolb, C. E. and Molina, M. J. Jet Propulsion Laboratory NASA-CR-198863, JPL-PUBL-94-26, NAS 1.26:198863 NAS7-1260; RTOP 464-41-04-01-00...
Download or read book Atmospheric Chemistry written by Barbara J. Finlayson-Pitts and published by Wiley-Interscience. This book was released on 1986 with total page 1164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides comprehensive coverage of the new and emerging discipline of atmospheric chemistry. Starting with the fundamentals of kinetics and photochemistry, it shows how the experimental techniques in these areas are applied to the study and control of chemical reactions in the troposphere. Gives detailed analysis of such major societal issues as smog, acid rain and volatile toxic organics, and treats the seven criteria pollutants considered by the U.S. Environmental Protection Agency to be hazardous, as well as a variety of trace non-criteria pollutants, such as those cited in the Clean Air Act of 1977. Also included is a comprehensive bibliography and over 340 illustrations.
Download or read book Spectroscopy and Kinetics written by James S. Mattson and published by Marcel Dekker. This book was released on 1973 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Oxidation Processes for Water Treatment written by Mihaela I. Stefan and published by IWA Publishing. This book was released on 2017-09-15 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Oxidation Processes (AOPs) rely on the efficient generation of reactive radical species and are increasingly attractive options for water remediation from a wide variety of organic micropollutants of human health and/or environmental concern. Advanced Oxidation Processes for Water Treatment covers the key advanced oxidation processes developed for chemical contaminant destruction in polluted water sources, some of which have been implemented successfully at water treatment plants around the world. The book is structured in two sections; the first part is dedicated to the most relevant AOPs, whereas the topics covered in the second section include the photochemistry of chemical contaminants in the aquatic environment, advanced water treatment for water reuse, implementation of advanced treatment processes for drinking water production at a state-of-the art water treatment plant in Europe, advanced treatment of municipal and industrial wastewater, and green technologies for water remediation. The advanced oxidation processes discussed in the book cover the following aspects: - Process principles including the most recent scientific findings and interpretation. - Classes of compounds suitable to AOP treatment and examples of reaction mechanisms. - Chemical and photochemical degradation kinetics and modelling. - Water quality impact on process performance and practical considerations on process parameter selection criteria. - Process limitations and byproduct formation and strategies to mitigate any potential adverse effects on the treated water quality. - AOP equipment design and economics considerations. - Research studies and outcomes. - Case studies relevant to process implementation to water treatment. - Commercial applications. - Future research needs. Advanced Oxidation Processes for Water Treatment presents the most recent scientific and technological achievements in process understanding and implementation, and addresses to anyone interested in water remediation, including water industry professionals, consulting engineers, regulators, academics, students. Editor: Mihaela I. Stefan - Trojan Technologies - Canada
Download or read book Double Gyroid Structured Functional Materials written by Maik Rudolf Johann Scherer and published by Springer Science & Business Media. This book was released on 2013-06-25 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of new high-tech applications and devices has created a seemingly insatiable demand for novel functional materials with enhanced and tailored properties. Such materials can be achieved by three-dimensional structuring on the nanoscale, giving rise to a significant enhancement of particular functional characteristics which stems from the ability to access both surface/interface and bulk properties. The highly ordered, bicontinuous double-gyroid morphology is a fascinating and particularly suitable 3D nanostructure for this purpose due to its highly accessible surface area, connectivity, narrow pore diameter distribution and superb structural stability. The presented study encompasses a wide range of modern nanotechnology techniques in a highly versatile bottom-up nanopatterning strategy that splits the fabrication process into two successive steps: the preparation of mesoporous double-gyroid templates utilizing diblock copolymer self-assembly, and their replication with a functional material employing electrochemical deposition and atomic layer deposition. The double-gyroid structured materials discussed include metals, metal oxides, and conjugated polymers, which are applied and characterized in high-performance devices, such as electrochromic displays, supercapacitors, chemical sensors and photovoltaics. This publication addresses a wide range of readers, from researchers and specialists who are professionally active in the field, to more general readers interested in chemistry, nanoscience and physics.
Download or read book Cold Plasma in Food and Agriculture written by NN Misra and published by Academic Press. This book was released on 2016-07-15 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cold Plasma in Food and Agriculture: Fundamentals and Applications is an essential reference offering a broad perspective on a new, exciting, and growing field for the food industry. Written for researchers, industry personnel, and students interested in nonthermal food technology, this reference will lay the groundwork of plasma physics, chemistry, and technology, and their biological applications. Food scientists and food engineers interested in understanding the theory and application of nonthermal plasma for food will find this book valuable because it provides a roadmap for future developments in this emerging field. This reference is also useful for biologists, chemists, and physicists who wish to understand the fundamentals of plasma physics, chemistry, and technology and their biological interactions through applying novel plasma sources to food and other sensitive biomaterials. Examines the topic of cold plasma technology for food applications Demonstrates state-of-the-art developments in plasma technology and potential solutions to improve food safety and quality Presents a solid introduction for readers on the topics of plasma physics and chemistry that are required to understand biological applications for foods Serves as a roadmap for future developments for food scientists, food engineers, and biologists, chemists, and physicists working in this emerging field
Download or read book Mechanisms of Atmospheric Oxidation of the Alkanes written by Jack G Calvert and published by Oxford University Press. This book was released on 2008-09-15 with total page 1005 pages. Available in PDF, EPUB and Kindle. Book excerpt: An international team of eminent atmospheric scientists have prepared Mechanisms of Atmospheric Oxidation of the Alkanes as an authoritative source of information on the role of alkanes in the chemistry of the atmosphere. The book includes the properties of the alkanes and haloalkanes, as well as a comprehensive review and evaluation of the existing literature on the atmospheric chemistry of the alkanes and their major atmospheric oxidation products, and the various approaches now used to model the alkane atmospheric chemistry. Comprehensive coverage is given of both the unsubstituted alkanes and the many haloalkanes. All the existing quality measurements of the rate coefficients for the reactions of OH, Cl, O(3P), NO3, and O3 with the alkanes, the haloalkanes, and their major oxidation products have been reviewed and evaluated. The expert authors then give recommendations of the most reliable kinetic data. They also review the extensive literature on the mechanisms and rates and modes of photodecomposition of the haloalkanes and the products of atmospheric oxidation of the alkanes and the haloalkanes, and make recommendations for future use by atmospheric scientists. The evaluations presented allow an extrapolation of the existing kinetic and photochemical data to those alkanes and haloalkanes that are as yet unstudied. The current book should be of special interest and value to the modelers of atmospheric chemistry as a useful input for development of realistic modules designed to simulate the atmospheric chemistry of the alkanes, their major oxidation products, and their influence on ozone and other trace gases within the troposphere.
Download or read book Aerosol Science written by Ian Colbeck and published by John Wiley & Sons. This book was released on 2014-02-03 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: AEROSOL SCIENCE TECHNOLOGY AND APPLICATIONS Aerosols influence many areas of our daily life. They are at the core of environmental problems such as global warming, photochemical smog and poor air quality. They can also have diverse effects on human health, where exposure occurs in both outdoor and indoor environments. However, aerosols can have beneficial effects too; the delivery of drugs to the lungs, the delivery of fuels for combustion and the production of nanomaterials all rely on aerosols. Advances in particle measurement technologies have made it possible to take advantage of rapid changes in both particle size and concentration. Likewise, aerosols can now be produced in a controlled fashion. Reviewing many technological applications together with the current scientific status of aerosol modelling and measurements, this book includes: Satellite aerosol remote sensing The effects of aerosols on climate change Air pollution and health Pharmaceutical aerosols and pulmonary drug delivery Bioaerosols and hospital infections Particle emissions from vehicles The safety of emerging nanomaterials Radioactive aerosols: tracers of atmospheric processes With the importance of this topic brought to the public's attention after the eruption of the Icelandic volcano Eyjafjallajökull, this book provides a timely, concise and accessible overview of the many facets of aerosol science.
Download or read book Free Radical Induced DNA Damage and Its Repair written by Clemens Sonntag and published by Springer Science & Business Media. This book was released on 2006-03-20 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: The free-radical chemistry of DNA had been discussed in some detail in 1987 in my book The Chemical Basis of Radiation Biology. Obviously, the more recent developments and the concomitant higher level of understanding of mechanistic details are missing. Moreover, in the living cell, free-radical DNA damage is not only induced by ionizing radiation, but free-radical-induced DNA damage is a much more general phenomenon. It was, therefore, felt that it is now timely to review our present knowledge of free-radical-induced DNA damage induced by all conceivable free-radical-generating sources. Originally, it had been thought to include also a very important aspect, the repair of DNA damage by the cell’s various repair enzymes. Kevin Prise (Cancer Campaign, Gray Laboratory, L- don) was so kind to agree to write this part. However, an adequate description of this strongly expanding area would have exceeded the allocated space by much, and this section had to be omitted. The directors of the Max-Planck-Institut für Strahlenchemie (now MPI für Bioanorganische Chemie), Karl Wieghardt and Wolfgang Lubitz, kindly allowed me to continue to use its facilities after my retirement in 2001. Notably, our - brarian, Mrs. Jutta Theurich, and her right-hand help, Mrs. Rosemarie Schr- er, were most helpful in getting hold of the literature. I thank them very much. Without their constant help, this would have been very difficult indeed.
Download or read book Biotransformations in Organic Chemistry written by Kurt Faber and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of natural catalysts -enzymes -for the transformation of non-natural man-made organic compounds is not at all new: they have been used for more than one hundred years, employed either as whole cells, cell organelles or isolated enzymes [1, 2]. Certainly, the object of most of the early research was totally different from that of the present day. Thus the elucidation of biochemical pathways and enzyme mechanisms was the main reason for research some decades ago. It was mainly during the 1980s that the enormous potential of applying natural catalysts to transform non-natural organic compounds was recognized. What started as a trend in the late 1970s could almost be called a fashion in synthetic organic chemistry in the 1990s. Although the early euphoria during the 'gold rush' in this field seems to have eased somewhat, there is still no limit to be seen for the future development of such methods. As a result of this extensive, recent research, there have been an estimated 12000 papers published on the subject. To collate these data as a kind of 'super-review' would clearly be an impossible task and, furthermore, such a hypothetical book would be unpalatable for the non-expert [3-6].
