Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 66 for “"Organic Aerosol"”.
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Atmospheric organic aerosol - water interactions
Atmospheric aerosols are responsible for adverse health effects and uncertain climate forcing. Depending on their composition, they can directly affect climate by scattering or absorbing solar radiation and they can also indirectly affect by serving as cloud condensation nuclei (CCN). While the …
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Decadal trends in atmospheric organic aerosol :
Organic aerosol (OA) makes up a substantial fraction of atmospheric particulate matter, yet its sources and controlling factors - and thus its impacts on climate and human health - are not well understood. Recently-developed analytical techniques have provided new insight into OA chemistry, but …
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Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity
… in predicting the ultimate effect of aerosol on climate, the sources of atmospheric particles and their subsequent ability to turn into cloud droplets needs to be better understood. This thesis addresses two parts of this issue: the sources of Arctic aerosol and the hygroscopicity of …
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Modeling secondary organic aerosol formation from biogenic hydrocarbons
<p>Secondary organic aerosol (SOA) is formed generally by the oxidation of gas-phase volatile organic compounds (VOCs) to form semi- or non-volatile products that then undergo gas to particle partitioning. In this work, the Caltech Atmospheric Chemistry Mechanism (CACM) and the Model to Predict the …
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Investigating the ice nucleation activity of organic aerosol
Emissions of aerosol particles and their precursors affect climate directly by scattering radiation and indirectly by altering cloud properties. Aerosol-induced ice nucleation includes several processes that impact cloud formation, lifetime, albedo, and precipitation efficiency. Ice nucleating …
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Simulating the sources of organic aerosol in the atmosphere
… on the energy balance of the planet. The organic components of particulate matter contribute more than 50% to their total mass. Organic aerosols (OA) are emitted into the atmosphere directly as primary organic aerosols or they can be formed through the condensation of low volatility …
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New Measurement Approaches to the Study of Secondary Organic Aerosol
Aerosol particles constitute a class of atmospheric pollutants that are detrimental to human health and influence the Earth’s climate. A significant fraction of aerosol mass is composed of organic material, produced by photochemical reactions of organic trace gases which form secondary organic …
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Secondary organic aerosol formation of relevance to the marine boundary layer
… atom (Cl) is a potential oxidant of volatile organic compounds (VOCs) in the atmosphere and is hypothesized to lead to secondary organic aerosol (SOA) formation in coastal areas. The purpose of this dissertation is to test this hypothesis and quantify the SOA formation potentials of some …
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Laboratory studies of the multiday oxidative aging of atmospheric organic aerosol
Fine particulate matter (PM, or "aerosol") in the atmosphere affects the Earth's radiative balance and is one of the most important risk factors leading to premature mortality worldwide. Thus, understanding the processes that control the loading and chemical composition of PM in the atmosphere is …
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Role of Water in the Formation, Transformation and Fate of Secondary Organic Aerosol
… water is the most abundant atmospheric aerosol constituent, yet the importance of water for the formation, transformation and fate of secondary organic aerosol (SOA) remains not fully characterized. In order to address this knowledge gap, this thesis explores the role of water in SOA …
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Chemical and Physical Studies of Secondary Organic Aerosol Formed from Beta-pinene Photooxidation
Atmospheric organic aerosols have a significant impact on climate and human health. However, our understanding of the physical and chemical properties of these aerosols is inadequate, thus their climate and health influences are poorly constrained. In this study, we investigated the secondary …
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The aging of organic aerosol in the atmosphere : chemical transformations by heterogeneous oxidation
The immense chemical complexity of atmospheric organic particulate matter ("aerosol") has left the general field of condensed-phase atmospheric organic chemistry relatively under-developed when compared with either gas-phase chemistry or the formation of inorganic compounds. In this work, we …
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The role of aqueous-phase oxidation in the formation of highly-oxidized organic aerosol
Atmospheric particulate matter (or "aerosol") is known to have important implications for climate change, air quality, and human health. Our ability to predict its formation and fate is hindered by uncertainties associated with one type in particular, organic aerosol (OA). Ambient OA measurements …
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Formation of secondary organic aerosol and its processing by atmospheric halogen species – A spectroscopic study
Atmospheric aerosols play an important role in the global climate system. Through their physicochemical properties, they contribute in various ways to climate change and radiative forcing. Those properties can be considerably changed by processing the aerosols, which is especially significant for …
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Hygroscopic growth and cloud condensation nuclei activity of fresh and chemically-aged biomass-pyrolyzed organic aerosol
… burning is one of the prominent contributors of organic aerosols and cloud condensation nuclei (CCN) in the atmosphere. Aerosol-cloud interactions contribute to uncertainties in estimates of climate forcing, not only because of the complexities in their initial size and chemical composition, but …
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Investigating the Molecular Composition of Rainwater and Secondary Organic Aerosol using Ultra-High Resolution Mass Spectrometry
… provide complete molecular characterisation of organic aerosol. However atmospheric aerosol often has complex, mixed organic and inorganic composition and soft ionisation techniques that have been developed to ionise organic aerosol specifically, are susceptible to salt suppression effects and …
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