Solar Photo Rate Coefficients


Book Description




Solar Photo Rates for Planetary Atmospheres and Atmospheric Pollutants


Book Description

A quantitative measure of the accuracy of the rate coefficients and the excess energies is a desirable goal of this analysis. There are two major sources of uncertainties: The atomic and molecular data and the solar irradiance. The cross sections and branching ratios used in this analysis come from many different sources; many of them without any error indications. For this reason, we must confine ourselves to a qualitative indication of the reliability of the results. Specifically we give a quality scale in Table II for the data of each mother molecule; A indicating the highest quality of atomic and molecular data and F the lowest quality. The letter B typically means that the threshold is uncertain. For most molecules the cross section at threshold is very small and the rate coefficient for these molecules is therefore not influenced by this uncertainty. For atomic species the cross section is usually large near threshold, but for these species the threshold is known quite accurately. The letter B, therefore, indicates that the rate coefficient is most likely quite accurate, but the excess energy is less accurately known. The letter C usually means that the branching ratios are not well known. This means that the total rate coefficient is very good, but the rate coefficients and the excess energies for the individual branches are less accurate.




The Photochemistry of Atmospheres


Book Description

The Photochemistry of Atmospheres: Earth, the Other Planets, and Comets discusses the photochemical and chemical processes in atmospheres This book focuses on the earth's atmosphere in the past, present, and future, atmospheres of other planets and their satellites, and comets. General topics in atmospheric photochemistry, such as composition and structure, transfer of incoming solar radiation, and principles governing the rates of photochemical and chemical processes are also elaborated. This text also covers the role of eddy and molecular transport and continuity-transport equation used in theoretical numerical modeling studies. This publication is recommended for advanced-level courses in the atmospheric and planetary sciences, as well as reference for those interested in learning about atmospheric/climatic environmental problems, their causes and consequences, and discoveries concerning the atmospheres of neighboring worlds.







Heterogeneous Photocatalysis


Book Description

Heterogeneous Photocatalysis: Relationships with Heterogeneous Catalysis and Perspectives highlights the differences between thermal-catalysis and photo-catalysis and indicates borderlines, in particular, the possible synergism between them. The book outlines the basic aspect of thermal- and photo-catalysis, along with the most important characterization techniques. In addition, it presents case studies of thermal-catalytic and photo-catalytic or thermal-photo-catalytic reactions and includes a comparison between the results obtained using an inorganic solid as thermal catalyst and photocatalyst for the same reaction, and in the same setup. Final sections offer information on the preparation methods of (photo)catalysts, various techniques used for their characterization, engineering and economical aspects. This book will be a valuable reference source for students and researchers involved in heterogeneous photocatalysis and catalysis, chemistry, chemical engineering, materials science, materials engineering, environment engineering, nanotechnology and green chemistry. - Provides selective methods for the preparation of microcrystalline/nanocrystalline solids or films used in catalytic and photocatalytic processes - Describes (photo)reactions that can be carried out catalytically and/or photocatalytically - Outlines the different mechanisms, yields and experimental conditions under which photocatalytic reactions can take place - Describes various (photo)reactors and set ups under which the photacatalytic reactions can be carried out - Provides an economic assessment to understand the feasibility of some photocatalytic reactions







Comets in the Post-Halley Era


Book Description

In Part Based on Reviews Presented at the 121st Colloquium of the International Astronomical Union, held in Bamberg, Germany, April 24-28, 1989




Comparative Aeronomy


Book Description

Andrew F. Nagy Originally published in the journal Space Science Reviews, Volume 139, Nos 1–4. DOI: 10. 1007/s11214-008-9353-0 © Springer Science+Business Media B. V. 2008 Keywords Aeronomy The term “aeronomy” has been used widely for many decades, but its origin has mostly been lost over the years. It was introduced by Sydney Chapman in a Letter to the Editor, entitled “Some Thoughts on Nomenclature”, in Nature in 1946 (Chapman 1946). In that letter he suggested that aeronomy should replace meteorology, writing that the word “meteor is now irrelevant and misleading”. This proposal was apparently not received with much support so in a short note in Weather in 1953 Chapman (1953)wrote: “If, despite its obvious convenience of brevity in itself and its derivatives, it does not commend itself to aeronomers, I think there is a case for modifying my proposal so that instead of the word being used to signify the study of the atmosphere in general, it should be adopted with the restricted sense of the science of the upper atmosphere, for which there is no convenient short word. ” In a chapter, he wrote in a 1960 book (Chapman 1960), he give his nal and de nitive de nition, by stating that “Aeronomy is the science of the upper region of the atmosphere, where dissociation and ionization are important”. The Workshop on “Comparative Aeronomy” was held at ISSI during the week of June 25–29, 2007.




Analysis of Returned Comet Nucleus Samples


Book Description

The abstracts deal with the nature of cometary ices, cryogenic handling and sampling equipment, origin and composition of samples, and spectroscopic, thermal and chemical processing methods of cometary nuclei. Laboratory simulation experimental results on dust samples are reported. Some results obtained from Halley's comet are also included. Microanalytic techniques for examining trace elements of cometary particles, synchrotron x ray fluorescence and instrument neutron activation analysis (INAA), are presented.




Origin and Early Evolution of Comet Nuclei


Book Description

Comet nuclei are the most primitive bodies in the solar system. They have been created far away from the early Sun and it is supposed that their material has been altered the least since their formation. This volume presents the results of a scientific workshop on comet nuclei and is written by experts working on interstellar clouds, star-forming regions, the solar nebula, and comets. The articles formulate the current understanding and interconnectivity of the various source regions of comet nuclei and their associated compositions and orbital characteristics. This includes a discussion on the transport of materials into the Kuiper belt and Oort cloud regions of the solar system. The distinction between direct measurements of cometary material properties and properties derived from indirect means are emphasized with the aim to guide future investigations. This book serves as a guide for researchers and graduate students working in the field of planetology and solar system exploration. It should also help to influence the planning of scientific strategies for the encounter of the Rosetta spacecraft with Comet Churyumov-Gerasimenko.