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Author: James Ricky Hite
Publisher:
ISBN:
Category : Air
Languages : en
Pages :
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Book Description
Secondary organic aerosol (SOA) generated through the partitioning of gas phase volatile organic carbon compounds (VOCs) into the condensed phase has both epidemiological and climatic impacts through the growth of particulate matter into relevant sizes for respiratory interactions and cloud condensation nuclei activity. Considering the complex chemistry involved with VOC oxidation and subsequent formation of SOA, bulk properties like oxidation state, often represented by O:C ratio, and volatility are used to simplify the representation of SOA in chemical transport models (CTMs) and the like [e.g. Tsimpidi et al. 2010]. This preference for bulk properties is supported by the availability of ambient measurement techniques to constrain model parameters and scenarios. The volatility of SOA is often described by treating it as a mixture of components with differing partitioning coefficients through the volatility basis set (VBS) approach rather than explicitly resolving the complex chemistry [Donahue et al., 2006]. This study presents a method of determining the volatility of an aerosol sample through the use of an optimizing thermodenuder (TD) instrument model that is used to fit laboratory data. Data collected using a volatility tandem differential mobility analyzer (VTDMA) setup consist of inlet and outlet particle size and number concentrations for select dicarboxylic acids - compounds known to contribute to atmospheric SOA. These are interpreted by the model through an iterative optimization routine to obtain estimates of volatility parameters (e.g. saturation concentrations) which are compared to available literature data. The instrument model is currently divided into two decoupled modules. The first resolves the flow field characteristics, obtaining the temperature profile, pressure variations, and radial velocity distribution of the TD, and the second resolves the gas to particle partitioning of aerosol with a given condensed-phase volatility distribution in the TD using the VBS approach as described in the literature. Solving the full hydrodynamic equations for the flow characteristics provides a better numeric representation of entry length and radial velocity variations and is an improvement over similar TD modeling studies in the literature. However, results indicate that coupling the two modules is necessary to more accurately resolve the suppression of evaporation due to buildup of organic vapors in the TD, even at the low mass concentrations involved with the presented experiments.
Author: James Ricky Hite
Publisher:
ISBN:
Category : Air
Languages : en
Pages :
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Book Description
Secondary organic aerosol (SOA) generated through the partitioning of gas phase volatile organic carbon compounds (VOCs) into the condensed phase has both epidemiological and climatic impacts through the growth of particulate matter into relevant sizes for respiratory interactions and cloud condensation nuclei activity. Considering the complex chemistry involved with VOC oxidation and subsequent formation of SOA, bulk properties like oxidation state, often represented by O:C ratio, and volatility are used to simplify the representation of SOA in chemical transport models (CTMs) and the like [e.g. Tsimpidi et al. 2010]. This preference for bulk properties is supported by the availability of ambient measurement techniques to constrain model parameters and scenarios. The volatility of SOA is often described by treating it as a mixture of components with differing partitioning coefficients through the volatility basis set (VBS) approach rather than explicitly resolving the complex chemistry [Donahue et al., 2006]. This study presents a method of determining the volatility of an aerosol sample through the use of an optimizing thermodenuder (TD) instrument model that is used to fit laboratory data. Data collected using a volatility tandem differential mobility analyzer (VTDMA) setup consist of inlet and outlet particle size and number concentrations for select dicarboxylic acids - compounds known to contribute to atmospheric SOA. These are interpreted by the model through an iterative optimization routine to obtain estimates of volatility parameters (e.g. saturation concentrations) which are compared to available literature data. The instrument model is currently divided into two decoupled modules. The first resolves the flow field characteristics, obtaining the temperature profile, pressure variations, and radial velocity distribution of the TD, and the second resolves the gas to particle partitioning of aerosol with a given condensed-phase volatility distribution in the TD using the VBS approach as described in the literature. Solving the full hydrodynamic equations for the flow characteristics provides a better numeric representation of entry length and radial velocity variations and is an improvement over similar TD modeling studies in the literature. However, results indicate that coupling the two modules is necessary to more accurately resolve the suppression of evaporation due to buildup of organic vapors in the TD, even at the low mass concentrations involved with the presented experiments.
Author: H.R. Pruppacher
Publisher: Springer Science & Business Media
ISBN: 0306481006
Category : Science
Languages : en
Pages : 975
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Book Description
Cloud physics has achieved such a voluminous literature over the past few decades that a significant quantitative study of the entire field would prove unwieldy. This book concentrates on one major aspect: cloud microphysics, which involves the processes that lead to the formation of individual cloud and precipitation particles. Common practice has shown that one may distinguish among the following addi tional major aspects: cloud dynamics, which is concerned with the physics respon sible for the macroscopic features of clouds; cloud electricity, which deals with the electrical structure of clouds and the electrification processes of cloud and precipi tation particles; and cloud optics and radar meteorology, which describe the effects of electromagnetic waves interacting with clouds and precipitation. Another field intimately related to cloud physics is atmospheric chemistry, which involves the chemical composition ofthe atmosphere and the life cycle and characteristics of its gaseous and particulate constituents. In view of the natural interdependence of the various aspects of cloud physics, the subject of microphysics cannot be discussed very meaningfully out of context. Therefore, we have found it necessary to touch briefly upon a few simple and basic concepts of cloud dynamics and thermodynamics, and to provide an account of the major characteristics of atmospheric aerosol particles. We have also included a separate chapter on some of the effects of electric fields and charges on the precipitation-forming processes.
Author: George T. Wolff
Publisher: Springer
ISBN: 9781468441567
Category : Science
Languages : en
Pages : 412
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Book Description
This book contains the papers and discussions from the symposium, "PARTICU LATE CARBON: Atmospheric Life Cycle," held at the General Motors Research Laboratories on October 13-14, 1980. This symposium, which focused on atmospheric particulate elemental carbon, or soot, was the twenty-fifth in this series sponsored by the General Motors Research Laboratories. The present symposium volume contains discussions of the following aspects of particulate elemental carbon (EC): the atmos pheric life cycle of EC including sources, sinks, and transport processes, the role of EC in atmospheric chemistry and optics, the possible role of EC in altering climate, and measurement techniques as well as ambient concentrations in urban, rural, and remote areas. Previous symposia have covered a wide range of scientific and engineering subjects. Topics are selected because they are new or represent rapidly changing fields and are of significant technical importance. It is ironic that the study of particulate elemental carbon or soot should meet the above criteria for selection because soot, especially from coal and wood combustion, has been a recognized air pollutant for centuries. However, since the 1950s, when intense efforts to study air pollution were initiated, to until a few years ago, the role of elemental carbon in the atmosphere was largely ignored. The major reason for this was the lack of a suitable measurement technique.
Author: Suhas Patankar
Publisher: CRC Press
ISBN: 1351991515
Category : Science
Languages : en
Pages : 218
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Book Description
This book focuses on heat and mass transfer, fluid flow, chemical reaction, and other related processes that occur in engineering equipment, the natural environment, and living organisms. Using simple algebra and elementary calculus, the author develops numerical methods for predicting these processes mainly based on physical considerations. Through this approach, readers will develop a deeper understanding of the underlying physical aspects of heat transfer and fluid flow as well as improve their ability to analyze and interpret computed results.
Author: Weidong Chen
Publisher: Elsevier
ISBN: 0128156899
Category : Science
Languages : en
Pages : 634
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Book Description
Advances in Spectroscopic Monitoring of the Atmosphere provides a comprehensive overview of cutting-edge technologies and monitoring applications. Concepts are illustrated by numerous examples with information on spectroscopic techniques and applications widely distributed throughout the text. This information is important for researchers to gain an overview of recent developments in the field and make informed selections among the most suitable techniques. This volume also provides information that will allow researchers to explore implementing and developing new diagnostic tools or new approaches for trace gas and aerosol sensing themselves. Advances in Spectroscopic Monitoring of the Atmosphere covers advanced and newly emerging spectroscopic techniques for optical metrology of gases and particles in the atmosphere. This book will be a valuable reference for atmospheric scientists, including those whose focus is applying the methods to atmospheric studies, and those who develop instrumentation. It will also serve as a useful introduction to researchers entering the field and provide relevant examples to researchers and students developing and applying optical sensors for a variety of other scientific, technical, and industrial uses. - Overview of new applications including remote sensing by UAV, laser heterodyne radiometry, dual comb spectroscopy, and more - Features in-situ observations and measurements for real-world data - Includes content on leading edge optical sensors
Author: Sherri W. Hunt
Publisher: ACS Symposium
ISBN: 9780841233638
Category : Science
Languages : en
Pages : 0
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Book Description
This book highlights new cross-disciplinary advances in aerosol chemistry that involve more than one phase, for example, unique chemical processes occurring on gas-solid and liquid-solid interfaces.
Author: V. Faye McNeill
Publisher: Springer
ISBN: 3642412157
Category : Science
Languages : en
Pages : 267
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Book Description
Christian George, Barbara D’Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann - Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard - New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll - Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde - Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization. V. Faye McNeill, Neha Sareen, Allison N. Schwier - Surface-Active Organics in Atmospheric Aerosols.
Author: Olivier Boucher
Publisher: Springer
ISBN: 9401796491
Category : Science
Languages : en
Pages : 322
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Book Description
This textbook aims to be a one stop shop for those interested in aerosols and their impact on the climate system. It starts with some fundamentals on atmospheric aerosols, atmospheric radiation and cloud physics, then goes into techniques used for in-situ and remote sensing measurements of aerosols, data assimilation, and discusses aerosol-radiation interactions, aerosol-cloud interactions and the multiple impacts of aerosols on the climate system. The book aims to engage those interested in aerosols and their impacts on the climate system: graduate and PhD students, but also post-doctorate fellows who are new to the field or would like to broaden their knowledge. The book includes exercises at the end of most chapters. Atmospheric aerosols are small (microscopic) particles in suspension in the atmosphere, which play multiple roles in the climate system. They interact with the energy budget through scattering and absorption of solar and terrestrial radiation. They also serve as cloud condensation and ice nuclei with impacts on the formation, evolution and properties of clouds. Finally aerosols also interact with some biogeochemical cycles. Anthropogenic emissions of aerosols are responsible for a cooling effect that has masked part of the warming due to the increased greenhouse effect since pre-industrial time. Natural aerosols also respond to climate changes as shown by observations of past climates and modelling of the future climate.
Author: John M. Prausnitz
Publisher: Pearson Education
ISBN: 0132440504
Category : Science
Languages : en
Pages : 1150
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Book Description
The classic guide to mixtures, completely updated with new models, theories, examples, and data. Efficient separation operations and many other chemical processes depend upon a thorough understanding of the properties of gaseous and liquid mixtures. Molecular Thermodynamics of Fluid-Phase Equilibria, Third Edition is a systematic, practical guide to interpreting, correlating, and predicting thermodynamic properties used in mixture-related phase-equilibrium calculations. Completely updated, this edition reflects the growing maturity of techniques grounded in applied statistical thermodynamics and molecular simulation, while relying on classical thermodynamics, molecular physics, and physical chemistry wherever these fields offer superior solutions. Detailed new coverage includes: Techniques for improving separation processes and making them more environmentally friendly. Theoretical concepts enabling the description and interpretation of solution properties. New models, notably the lattice-fluid and statistical associated-fluid theories. Polymer solutions, including gas-polymer equilibria, polymer blends, membranes, and gels. Electrolyte solutions, including semi-empirical models for solutions containing salts or volatile electrolytes. Coverage also includes: fundamentals of classical thermodynamics of phase equilibria; thermodynamic properties from volumetric data; intermolecular forces; fugacities in gas and liquid mixtures; solubilities of gases and solids in liquids; high-pressure phase equilibria; virial coefficients for quantum gases; and much more. Throughout, Molecular Thermodynamics of Fluid-Phase Equilibria strikes a perfect balance between empirical techniques and theory, and is replete with useful examples and experimental data. More than ever, it is the essential resource for engineers, chemists, and other professionals working with mixtures and related processes.
Author: Henning Bockhorn
Publisher: Springer Science & Business Media
ISBN: 3642851673
Category : Science
Languages : en
Pages : 595
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Book Description
Soot Formation in Combustion represents an up-to-date overview. The contributions trace back to the 1991 Heidelberg symposium entitled "Mechanism and Models of Soot Formation" and have all been reedited by Prof. Bockhorn in close contact with the original authors. The book gives an easy introduction to the field for newcomers, and provides detailed treatments for the specialists. The following list of contents illustrates the topics under review:
