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 166 for “"Atmospheric Chemistry"”.
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Development & Testing of Novel Atmospheric Chemistry Technologies
<p>Atmospheric aerosols play an important role in global atmospheric chemistry and climate and have a detrimental impact on human health. Advancements in measurement technologies allow for better monitoring of atmospheric composition and dynamics, creating better predictive models and understanding …
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Modelling the atmospheric chemistry of volcanic plumes
… to model passive degassing from Mount Etna, the chemistry of its plume, and its influence on the wider atmosphere. This investigation considers model plumes from the point of emission up to a day’s travel from the vent and is able to reproduce observed phenomena of BrO formation and O3 depletion …
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Atmospheric chemistry and aerosol associated with the coastal urban environment
This study aims to understand the dynamics of atmospheric secondary organic aerosol (SOA) in Houston, Texas. It (1) explores the relationship between sea breeze and air quality, (2) investigates the spatiotemporal characteristics of aerosols and SOA formation rates, and (3) analyzes factors that …
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Cosmogenic 14 CO as tracer for atmospheric chemistry and transport
Advances in atmospheric chemistry research depend increasingly on the use of threedimensional (3-D) atmospheric transport and chemistry models. In this thesis the application of atmospheric 14CO measurements for evaluation of such models is systematically developed. Emphasis is on the simulated …
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Interactions of the Terrestrial Biosphere With Climate and Atmospheric Chemistry
… to significantly impact global tropospheric chemistry and composition, climate and the global carbon cycle. In the second part of this dissertation, the sensitivity of biogenic isoprene and monoterpene emissions to combined and isolated fluctuations in observed climate and atmospheric carbon …
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Investigating the pH of atmospheric fine particles and implications for atmospheric chemistry
… trends and the role of acidity in heterogeneous chemistry. We found that PM2.5 remained highly acidic despite a ~70% sulfate reduction in the southeastern U.S. in the last 15 years, due to buffering by semivolatile NH3; that the bias in molar ratio predictions in past studies is linearly …
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Investigating the influence of biosphere-atmosphere interactions on atmospheric chemistry and composition
… controlling factor for regional to global atmospheric chemistry and composition. This ultimately has wide impacts on issues like air quality and climate change. However, there are still substantial uncertainties in the biosphere-atmosphere interaction processes that drive the global …
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Volatile organic compounds in the New England troposphere: Atmospheric chemistry and measurement techniques
<p>Atmospheric measurements made at Appledore Island, Maine were used to investigate nighttime nitrate radical (NO3) chemistry and its significance for the nitrogen oxides (NOx = NO + NO2) budget in the Gulf of Maine region during the summer of 2004 International Consortium for Atmospheric Research …
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Modeling Interactions of Aircraft Emissions With Global and Regional Atmospheric Chemistry and Climate
In the last phase, we have focused on analyzing the impact of aircraft flights from Chicago O'Hare and Midway Airports on the regional air quality of the region using the Community Multiscale Air Quality Model (CMAQ) system. Our results suggest that the aircraft traffic at the Chicago O'Hare and …
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An uncertainty-focused approach to modeling the atmospheric chemistry of persistent organic pollutants
… of fuels, biomass, etc. PFCAs and their atmospheric precursors are used in making firefighting foams, non-stick coatings, and other surfactant applications. I quantitatively examine the relative importance of uncertainty in emissions and physicochemical properties (including reaction rate …
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Biofuels & atmospheric chemistry: what can a global model tell us about our future decisions?
… that large scale biofuel use could have on atmospheric chemistry. I review the current state of biofuels politically and technologically, focusing on ethanol and biodiesel. I discuss the salient features of tropospheric chemistry and in particular the oxidation of isoprene, an important …
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Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry
… to acetylene that is critical to oxidation chemistry both in the atmosphere and in combustion. As a result, many of the kinetic parameters that appear in commonly used combustion mechanisms are based purely on predictions. The few experiments that do attempt to quantify product branching …
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Chemical models for, and the role of data and provenance in, an atmospheric chemistry community
… research at the interface of the e-Science and atmospheric chemistry disciplines. Two inter-related research topics are addressed: first, the development of computational models of the troposphere (i.e. in silico experiments); and secondly, provenance capture and representation for data produced …
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Chemical models for, and the role of data and provenance in, an atmospheric chemistry community
… research at the interface of the e-Science and atmospheric chemistry disciplines. Two inter-related research topics are addressed: first, the development of computational models of the troposphere (i.e. in silico experiments); and secondly, provenance capture and representation for data produced …
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Effects of incomplete combustion on atmospheric chemistry: Black carbon climate forcing and global carbon monoxide emissions
… the role of incomplete combustion products on atmospheric chemistry. The first explores the sensitivity of black carbon (BC) forcing to aerosol vertical location since BC has an increased forcing per unit mass when it is located above reflective clouds. We used a column radiative transfer model …
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Observation of sulphate aerosols and SO2 from volcanic eruptions using data from the Atmospheric Chemistry Experiment (ACE)
Infrared spectra measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) on board of the SCISAT satellite were used to analyse the temporal and spatial evolution of volcanic aerosols from the Kasatochi (August 2008), Sarychev (June 2009) and Grimsvötn (May 2011) …
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The use of stable isotopes and particulate matter in the investigation of local and regional atmospheric chemistry
… valuable insight into local and regional atmospheric chemistry. Elemental analysis was used to evaluate local atmospheric chemistry at four sites in Southern California (Chula Vista, El Cajon, El Centro, and Brawley) and in Whangarei, New Zealand. PM in Southern California sites revealed …
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Atmospheric Chemistry of Outdoor and Indoor Environments: Physical and Chemical Characterization of Urban Grime and Measurements of Oxidants in Vehicle Cabins
<p>This work investigates chemistry in two distinct environments in urban atmospheres. The first is the coatings found on urban surfaces often referred to as urban grime. Urban grime may serve as an important medium for photochemical and heterogeneous reactions in cities. This study characterized …
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Impact of two potential policy options on atmospheric chemistry and climate: hydrogen economy and low-GWP alternatives to ozone depleting substances
… is now well recognized that the changes in the atmospheric composition due to human activities have resulted in changes in several aspects of the environment, e.g., attenuation of the ozone layer due to emissions of ozone-depleting substances, climate change due to greenhouse gas emissions, and …
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