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.
Results
Showing 1 to 20 of 44 for “"Secondary organic aerosol"”.
-
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 …
-
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 …
-
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 …
-
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 …
-
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 …
-
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 …
-
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 …
-
Understanding the formation of secondary organic aerosol and the fates of organic nitrates formed from monoterpene oxidation
Secondary organic aerosol (SOA) contributes to a substantial fraction of fine particular matter (PM2.5) that imposes adverse health effects, large uncertainty in radiative forcing, and poor visibility. Monoterpenes represent about 15% of the annual emissions of biogenic volatile organic compounds …
-
SPECIATION STUDIES FOR BIOGENIC VOLATILE ORGANIC COMPOUNDS AND SECONDARY ORGANIC AEROSOL GENERATED BY OZONOLYSIS OF VOLATILE ORGANIC COMPOUND MIXTURES
<p>Aerosols are either emitted directly into the atmosphere or are generated in the atmosphere; the latter process forms secondary organic aerosol (SOA). One of the important sources for SOA is the oxidation of volatile organic compounds (VOCs) by OH radicals, NOx, and O3. Aerosol can be visualized …
-
Novel Methods to Characterise Atmospherically Relevant Organic Radicals and Reactive Oxygen Species
… is known to produce a plethora of oxidised organic compounds, which contribute to ozone formation and secondary organic aerosol production, two of the main characteristics of a polluted atmosphere. Furthermore, epidemiological studies have shown a close correlation between exposure to …
-
Measurement and characterization of low volatility organic compounds in the atmosphere
Organic aerosol is a central topic in environmental science due to its role in climate forcing and negative health effects. The transformation of organic species from primary gas phase emissions to secondary organic aerosol (SOA) is highly complex and poorly understood, proving difficult for even …
-
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 …
-
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 …
-
Evaluating the Utility of an Atmospheric Pressure Chemical Ionization Mass Spectrometer for Detecting Organic Peroxides During Beta-Pinene Ozonolysis Experiments
… mass spectrometer ((+) APCI-MS/MS) to detect organic peroxide products formed during β-pinene ozonolysis experiments. Detection was based on utilizing the neutral-loss scan (NLS) analysis mode of the APCI-MS/MS to observe ion signals exhibiting unique mass losses of 34 u. This mass loss was …
-
Characterization and source apportionment of ambient PM2.5 in Atlanta, Georgia: on-road emission, biomass burning and SOA impact
… burning plumes, wildfire plumes, as well as secondary sources with anthropogenic and biogenic nature in origin. Detailed PM2.5 chemical speciation was conducted including over one hundred of GC/MS-quantified organic compounds, organic carbon (OC), water-soluble organic carbon (WSOC), …
Page 1 of 3