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 30 for “"Organic aerosols"”.
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Simulating the atmospheric primary and secondary organic aerosols
Until recently, organic particulate material was simply classified as either primary or secondary with the primary component being treated in models as nonvolatile and inert. This framework is used to simulate the organic aerosol formation, growth and composition in the eastern United States during …
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Secondary Organic Aerosols: Composition, Gas-to-Particle Partitioning and Physical Properties
Atmospheric aerosols influence our climate and air quality. Aerosol particles in the atmosphere are transformed through many different physical and chemical reactions. A substantial fraction of the particles in the atmosphere are of secondary origin, formed as a result of gas to particle …
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Emission of organic aerosols from wood combustion: Bridging the gap between aerosol science and wood pyrolysis
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2022-11-11 without embargo terms
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Ambient measurements of chemical and physical properties of organic aerosols: Insights into formation, growth, and heterogeneous chemistry
<p>Organic aerosols are a ubiquitous component of the troposphere, from heavily polluted cities to the remote Arctic. In Chapters II, III, and V of this dissertation, the formation of organic aerosol through observations of ambient size distributions is addressed. Chapter IV presents a new pathway …
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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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Dynamics of Atmospherically Important Triatomics in Collisions with Model Organic Surfaces
… study of heterogeneous chemistry of atmospheric organic aerosols. In addition to changing the chemical and physical properties of the particle, reactions with oxidizing gases may alter aerosol optical properties, with implications for the regional radiation budget and climate. Molecular beams of …
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Fine Particle and Mercury Formation and Control during Coal Combustion
… control from the coal combustion process: (1) organic aerosol formation during coal combustion, (2) mercury removal during coal combustion by injection of Vanadium Pentoxide (V2O5), and (3) submicrometer particle formation during oxy-coal combustion.</p><p>Part. 1. While the characterization …
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Ultrahigh Vacuum Studies of the Reaction Mechanisms of Ozone with Saturated and Unsaturated Self-Assembled Monolayers
… of the heterogeneous oxidation of atmospheric organic aerosols, both from a mechanistic and kinetic perspective, will enable researchers to predict the fate and lifetime of atmospheric gases and the particles with which they interact. In an effort to develop a more complete understanding of the …
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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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Enabling Routine Chemical Composition and Volatility Distribution Measurements of Aerosols
… monitoring of particulate matter, especially organic aerosol, relies instead on offline techniques such as filter collection that require significant operator effort. To address this gap, first, we built a new online semi-continuous aerosol chemical composition monitor, the "ChemSpot", that …
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Characterization, seasonality and source apportionment of fine particulate organic matter at urban an d rural sites
To better understand the sources of organic PM and the effect of secondary organic aerosols (SOA) on PM levels, samples of fine particulate matter were collected outside Durham, NC in the Duke Research Forest as part of the CELTIC study in July 2003. Among compounds analyzed, oxidation products of …
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Investigation of the evolution of atmospheric particles with integration of the stochastic particle-resolved model PartMC-MOSAIC and atmospheric measurements
Atmospheric aerosols are known to have strong impacts on human health, visibility and the climate system. They originate directly from either anthropogenic or natural emission, or can be also formed through gas- particle conversion processes. Aerosol particles in the atmosphere often represent a …
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Tholins: A Gas Phase Computational Study of Methanimine and Related Species
… Titan’s atmosphere contains an abundance of organic molecules, methanimine (MA) and it’s related species the methyl amino radical (MAR) and methyleneamine cation (MEC) are of particular interest. Scientists believe that MA, MAR, and MEC are precursors to organic aerosols called Tholins, which …
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Bacterial Degradation of Isoprene in the Terrestrial Environment
… of ozone, and induce the formation of secondary organic aerosols. While substantial knowledge exists about isoprene production and atmospheric chemistry, our knowledge of isoprene sinks is limited. Soils consume isoprene at a high rate and contain numerous isoprene-utilizing bacteria. However, …
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Chemistry of carbonaceous aerosols : studies of atmospheric processing and OH-initiated oxidation
Carbonaceous aerosols are among the most prevalent yet least understood constituents of the atmosphere, particularly in urban environments. We have performed analyses of field samples and laboratory studies to probe the physico-chemical properties of soot and organic aerosols in a complimentary …
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MEASUREMENTS AND MODEL PREDICTIONS OF HYDROXYL RADICAL, PEROXY RADICALS, AND NITROUS ACID: EVIDENCE OF MISSING SOURCES OR SINKS IN FORESTED AND INDOOR ENVIRONMENTS
… controlling the lifetimes of volatile organic compounds (VOCs) and contributing to the formation of ozone (O3) and secondary organic aerosols (SOA). The oxidation of VOCs by OH propagates a radical cycle between OH, the hydroperoxy radical (HO2), and organic peroxy radical (RO2). Due to …
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Multiphase Aging of Atmospheric Biomass Burning Brown Carbon
… by an increase in the oxidation state of the organic aerosols. The role that oxygen, and the subsequent reactive species formed by the presence of oxygen, plays in this absorption enhancement was also investigated. In particular, UV light exposure in the absence of oxygen does not lead to …
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MEASUREMENTS OF ATMOSPHERIC RADICALS IN AMBIENT AND INDOOR ENVIRONMENTS: OUTDOOR-INDOOR RELATIONSHIPS, INDOOR FORMATION MECHANISMS, AND INSTRUMENTAL ANALYSIS
… Radical reactions initiate oxidation of volatile organic compounds (VOCs), which in the presence of nitrogen oxides (NOx) can form ozone and secondary organic aerosols (SOA)—air pollutants affecting human health and welfare in ambient and indoor environments. In ambient environments with high …
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Field measurements and atmospheric simulation chamber studies of selected biomass burning marker compounds
… particles and gaseous species known as volatile organic compounds (VOCs) which can undergo chemical oxidation reactions in the atmosphere with hydroxyl (OH) and nitrate (NO3) radicals to produce secondary organic aerosols (SOA). While the particulate pollution has been well characterised, …
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