Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Tropospheric Chemistry of Ozone in the Polar Regions written by H. Niki and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Arctic troposphere (0 to ca. 8 km) plays an important role in environmental concerns for global change. It is a unique chemical reactor influenced by human activity and the Arctic ocean. It is surrounded by industrialized continents that in winter contribute gaseous and particulate pollution (Arctic haze). It is underlain by the flat Arctic ocean from which it is separated by a crack-ridden ice membrane 3 to 4 m thick. Ocean to atmosphere exchange of heat, water vapor and marine biogenic gases influence the composition of the reactor. From September 21 to December 21 to March 21, the region north of the Arctic circle goes from a completely sunlit situation to a completely dark one and then back to light. At the same time the lower troposphere is stably stratified. This hinders vertical mixing. During this light period, surface temperature reaches as low as -40°C. In this environment, chemical reactions involving sunlight are generally much slower than further south. Thus, the abundance of photochemically reactive compounds in the atmosphere can be high prior to polar sunrise. Between complete dark in February and complete light in April, a number of chemical changes in the lower troposphere take place.

Download or read book Scientific Assessment of Ozone Depletion 1991 written by and published by . This book was released on 1991 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book UV Effects in Aquatic Organisms and Ecosystems written by E Walter Helbling and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers extensive coverage of the most important aspects of UVR effects on all aquatic (not just freshwater and marine) ecosystems, encompassing UV physics, chemistry, biology and ecology. Comprehensive and up-to-date, UV Effects in Aquatic Organisms and Ecosystems aims to bridge the gap between environmental studies of UVR effects and the broader, traditional fields of ecology, oceanography and limnology. Adopting a synthetic approach, the different sections cover: the physical factors controlling UVR intensity in the atmosphere; the penetration and distribution of solar radiation in natural waters; the main photochemical process affecting natural and anthropogenic substances; and direct and indirect effects on organisms (from viruses, bacteria and algae to invertebrate and vertebrate consumers). Researchers and professionals in environmental chemistry, photochemistry, photobiology and cell and molecular biology will value this book, as will those looking at ozone depletion and global change.

Download or read book Applied Photochemistry written by Rachel C. Evans and published by Springer Science & Business Media. This book was released on 2014-07-08 with total page 619 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applied Photochemistry encompasses the major applications of the chemical effects resulting from light absorption by atoms and molecules in chemistry, physics, medicine and engineering, and contains contributions from specialists in these key areas. Particular emphasis is placed both on how photochemistry contributes to these disciplines and on what the current developments are. The book starts with a general description of the interaction between light and matter, which provides the general background to photochemistry for non-specialists. The following chapters develop the general synthetic and mechanistic aspects of photochemistry as applied to both organic and inorganic materials, together with types of materials which are useful as light absorbers, emitters, sensitisers, etc. for a wide variety of applications. A detailed discussion is presented on the photochemical processes occurring in the Earth’s atmosphere, including discussion of important current aspects such as ozone depletion. Two important distinct, but interconnected, applications of photochemistry are in photocatalytic treatment of wastes and in solar energy conversion. Semiconductor photochemistry plays an important role in these and is discussed with reference to both of these areas. Free radicals and reactive oxygen species are of major importance in many chemical, biological and medical applications of photochemistry, and are discussed in depth. The following chapters discuss the relevance of using light in medicine, both with various types of phototherapy and in medical diagnostics. The development of optical sensors and probes is closely related to diagnostics, but is also relevant to many other applications, and is discussed separately. Important aspects of applied photochemistry in electronics and imaging, through processes such as photolithography, are discussed and it is shown how this is allowing the increasing miniaturisation of semiconductor devices for a wide variety of electronics applications and the development of nanometer scale devices. The final two chapters provide the basic ideas necessary to set up a photochemical laboratory and to characterise excited states. This book is aimed at those in science, engineering and medicine who are interested in applying photochemistry in a broad spectrum of areas. Each chapter has the basic theories and methods for its particular applications and directs the reader to the current, important literature in the field, making Applied Photochemistry suitable for both the novice and the experienced photochemist.

Download or read book Photomovement written by D.-P. Häder and published by Elsevier. This book was released on 2001-06-19 with total page 959 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume emphasizes the involvement of all facets of biology in the analysis of environmentally controlled movement responses. This includes biophysics, biochemistry, molecular biology and as an integral part of any approach to a closer understanding, physiology. The initial euphoria about molecular biology as the final solution for any problem has dwindled and the field agrees now that only the combined efforts of all facets of biology will at some day answer the question posed more than hundred years ago: "How can plants see?". One conclusion can be drawn from the current knowledge as summarized in this volume. The answer will most likely not be the same for all systems.

Download or read book Advanced Oxidation Processes for Water and Wastewater Treatment written by Simon Parsons and published by IWA Publishing. This book was released on 2004-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The suitability of Advanced Oxidation Processes (AOPs) for pollutant degradation was recognised in the early 1970s and much research and development work has been undertaken to commercialise some of these processes. AOPs have shown great potential in treating pollutants at both low and high concentrations and have found applications as diverse as ground water treatment, municipal wastewater sludge destruction and VOCs control. Advanced Oxidation Processes for Water and Wastewater Treatment is an overview of the advanced oxidation processes currently used or proposed for the remediation of water, wastewater, odours and sludge. The book contains two opening chapters which present introductions to advanced oxidation processes and a background to UV photolysis, seven chapters focusing on individual advanced oxidation processes and, finally, three chapters concentrating on selected applications of advanced oxidation processes. Advanced Oxidation Processes for Water and Wastewater Treatment will be invaluable to readers interested in water and wastewater treatment processes, including professionals and suppliers, as well as students and academics studying in this area. Dr Simon Parsons is a Senior Lecturer in Water Sciences at Cranfield University with ten years' experience of industrial and academic research and development.

Download or read book Bioinorganic Photochemistry written by Grazyna Stochel and published by John Wiley & Sons. This book was released on 2009-06-10 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioinorganic photochemistry is a rapidly evolving field integrating inorganic photochemistry with biological, medical and environmental sciences. The interactions of light with inorganic species in natural systems, and the applications in artificial systems of medical or environmental importance, form the basis of this challenging inter-disciplinary research area. Bioinorganic Photochemistry provides a comprehensive overview of the concepts and reactions fundamental to the field, illustrating important applications in biological, medical and environmental sciences. Topics covered include: Cosmic and environmental photochemistry Photochemistry of biologically relevant nanoassemblies Molecular aspects of photosynthesis Photoinduced electron transfer in biosystems Modern therapeutic strategies in photomedicine The book concludes with an outlook for the future of environmental protection, discussing emerging techniques in the field of pollution abatement, and the potential for bioinorganic photochemistry as a pathway to developing cheap, environmentally friendly sources of energy. Written as an authoritative guide for researchers involved in the development of bioinorganic photochemical processes, Bioinorganic Photochemistry is also accessible to scientists new to the field, and will be a key reference source for advanced courses in inorganic, and bioinorganic chemistry.

Download or read book Photodegradation of Polymers written by Jan F. Rabek and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book on physical characteristics and practical aspects of polymer photodegradation Rabek emphasizes the experimental work on the subject. The most important feature of the book is the physical interpretation of polymer degradation, e.g. mechanism of UV/light absorption, formation of excited states, energy transfer mechanism, kinetics, dependence on physical properties of macromolecules and polymer matrices, formation of mechanical defects, practics during environmental ageing. He includes also some aspects of polymer photodegradation in environmental and space condition.

Download or read book Photostabilization of Polymers written by J.F. Rabek and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 607 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last two decades, the production of polymers and plastics has been increasing rapidly. In spite of developing new polymers and polymeric materials, only 40-60 are used commercially on a large scale. It has been estimated that half of the annual production of polymers is employed outdoors. Increasing the stability of polymers and plastics towards heat, light, atmospheric oxygen and other environmental agents and weathering conditions has always been a very important problem. The photochemical instability of most of polymers limits them to outdoor application, where they are photo degraded fast over periods ranging from months to a few years. To the despair of technologists and consumers alike, photodegrada tion and environmental ageing of polymers occur much faster than can be expected from knowledge collected in laboratories. In many cases, improved methods of preparation and purification of both monomers and polymers yield products of better quality and higher resistance to heat and light. However, without stabilization of polymers by applica tion of antioxidants (to decrease thermal oxidative degradation) and photostabilizers (to decrease photo-oxidative degradation) it would be impossible to employ polymers and plastics in everyday use.

Download or read book New and Future Developments in Catalysis written by Steven L Suib and published by Newnes. This book was released on 2013-07-19 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: New and Future Developments in Catalysis is a package of seven books that compile the latest ideas concerning alternate and renewable energy sources and the role that catalysis plays in converting new renewable feedstock into biofuels and biochemicals. Both homogeneous and heterogeneous catalysts and catalytic processes will be discussed in a unified and comprehensive approach. There will be extensive cross-referencing within all volumes.The use of solar energy during various catalytic chemical processes for the production of an array of chemical products is the theme of this volume. Photocatalysis is a topic of increasing importance due to its essential role in many of today's environmental and energy source problems. The use of solar energy for catalytic reactions results in a carbon dioxide–neutral process. All photocatalytic processes and the future developments in this area are discussed, including an economic analysis of the various processes. - Offers in-depth coverage of all catalytic topics of current interest and outlines future challenges and research areas - A clear and visual description of all parameters and conditions, enabling the reader to draw conclusions for a particular case - Outlines the catalytic processes applicable to energy generation and design of green processes

Download or read book Nanohybrid and Nanoporous Materials for Aquatic Pollution Control written by Lin Tang and published by Elsevier. This book was released on 2018-10-12 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanohybrid and Nanoporous Materials for Aqueous Environmental Pollution Control gives a comprehensive treatment of fabrication methods and their application in environmental remediation, including adsorption, catalysis and signal transfer in pollutant detection. The design, fabrication and application of nanohybrid and nanoporous materials for environmental pollution control are described in detail, along with discussions on their synthesis, characterization, and applications in different aspects of pollutant treatment. Chapters introduce the design and synthesis of magnetic nanohybrid materials, advanced oxide process-photocatalytic degradation of environmental pollutants based on nanomaterials, and nanohybrids of iron based materials for reduction and oxidation of aqueous recalcitrant pollutant. Finally, challenges and suggestions in the application of nanomaterials for environmental pollution control are discussed, as is an analysis of the future perspective of nanomaterials for environmental application. - Presents the most up-to-date developments in this rapidly progressing field - Provides suggestions to address challenges and solve current problems related to the application of nanoporous materials - Discusses future trends and perspectives in the area of nanohybrid and nanoporous materials

Download or read book Light as an Energy Source and Information Carrier in Plant Physiology written by Robert C. Jennings and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: A NATO Advanced Study Institute on "Light as Energy Source and Information Carrier in Plant Photo physiology" was held at Volterra, Italy, from September 26 to October 6, 1994, in order to consider the fundamental role that light plays in plant growth and development. This book summarises the main lectures given at this meeting which concentrated on both photochemical energy conversion and signalling (photosensing) aspects. Light harvesting and conversion into chemical energy in photosynthesis occurs at the level of chlorophyll/carotenoid containing photosystems in plants. Pigments are non covalently bound to a variety of polypeptides which serve as a specific scaffolding, necessary to determine the energy coupling between pigments and thus allowing rapid excitation energy trasfer from the antenna to the special reaction centre chlorophylls. Data from transient, time resolved spectroscopies, in the femtosecond and picosecond domain, together with model calculations, suggest that this process occurs in the 20-100 picosecond time span. The special ~ll u~ture of reaction centre complexes, ensures rapid primary charge separation, probably in the order of 1-3 picoseconds, with subsequent charge stabilisation reactions proceeding in the hundreds of picoseconds range. The recently resolved crystallographic structure of LHCII, the principal antenna complex of plants, allows precise determination of pigment-pigment distances and thus permits calculation of approximate chlorophyll-chlorophyll Forster hopping rates, which are in good agreement with time resolved measurements.

Download or read book Chemical Evolution written by Bernd Markert and published by Springer. This book was released on 2015-02-19 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is written for researchers and students interested in the function and role of chemical elements in biological or environmental systems. Experts have long known that the Periodic System of Elements (PSE) provides only an inadequate chemical description of elements of biological, environmental or medicinal importance. This book explores the notion of a Biological System of the Elements (BSE) established on accurate and precise multi-element data, including evolutionary aspects, representative sampling procedures, inter-element relationships, the physiological function of elements and uptake mechanisms. The book further explores the concept Stoichiometric Network Analysis (SNA) to analyze the biological roles of chemical species. Also discussed is the idea of ecotoxicological identity cards which give a first-hand description of properties relevant for biological and toxicological features of a certain chemical element and its geo biochemically plausible speciation form. The focus of this book goes beyond both classical bioinorganic chemistry and toxicology.

Download or read book The Biological Effects of UVA Radiation written by Frederick Urbach and published by Praeger Publishers. This book was released on 1986 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Active Protective Coatings written by Anthony E. Hughes and published by Springer. This book was released on 2016-03-01 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a broad range of materials science that has been brought to bear on providing solutions to the challenges of developing self-healing and protective coatings for a range of metals. The book has a strong emphasis on characterisation techniques, particularly new techniques that are beginning to be used in the coatings area. It features many contributions written by experts from various industrial sectors which examine the needs of the sectors and the state of the art. The development of self-healing and protective coatings has been an expanding field in recent years and applies a lot of new knowledge gained from other fields as well as other areas of materials science to the development of coatings. It has borrowed from fields such as the food and pharmaceutical industries who have used, polymer techniques, sol-gel science and colloidosome technology for a range encapsulation techniques. It has also borrowed from fields like hydrogen storage such as from the development of hierarchical and other materials based on organic templating as “nanocontainers” for the delivery of inhibitors. In materials science, recent developments in high throughput and other characterisation techniques, such as those available from synchrotrons, are being increasing used for novel characterisation – one only needs to look at the application of these techniques in self healing polymers to gauge wealth of new information that has been gained from these techniques. This work is largely driven by the need to replace environmental pollutants and hazardous chemicals that represent risk to humans such as chromate inhibitors which are still used in some applications.

Download or read book Prebiotic Photochemistry written by Franz Saija and published by Royal Society of Chemistry. This book was released on 2021-06-09 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photochemistry is an important facet in the study of the origin of life and prebiotic chemistry. Solar photons are the unique source of the large amounts of energy likely required to initiate the organisation of matter to produce biological life. The Miller–Urey experiment simulated the conditions thought to be present on the early earth and supported the hypothesis that under such conditions complex organic compounds could be synthesised from simpler inorganic precursors. The experiment inspired many others, including the production of various alcohols, aldehydes and organic acids through UV-photolysis of water vapour with carbon monoxide. This book covers the photochemical aspects of the study of prebiotic and origin of life chemistry an ideal companion for postgraduates and researchers in prebiotic chemistry, photochemistry, photobiology, chemical biology and astrochemistry.