Molecular Characterization Of Atmospheric Organic Matter In Biogenic Secondary Organic Aerosol, Ambient Aerosol And Clouds,
2014
Michigan Technological University
Molecular Characterization Of Atmospheric Organic Matter In Biogenic Secondary Organic Aerosol, Ambient Aerosol And Clouds, Yunzhu Zhao
Dissertations, Master's Theses and Master's Reports - Open
Atmospheric aerosol affects the Earth’s energy budget, reduces visibility and influences human health. The organic composition of aerosol is quite complex and continuously evolves through various atmospheric processes. To gain a deeper understanding of the molecular composition of atmospheric organic matter (AOM), chamber-generated biogenic secondary organic aerosol (SOA), ambient aerosol and cloud water samples were studied. Ultrahigh resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry was used to provide detailed molecular characterization of the atmospheric samples. Due to the extremely high mass resolution and mass accuracy, thousands of individual molecular formulas were identified in all of the samples studied. Multivariate …
Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model,
2014
Michigan Technological University
Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model, Keenan Anton Murray
Dissertations, Master's Theses and Master's Reports - Open
This work presents a 1-D process scale model used to investigate the chemical dynamics and temporal variability of nitrogen oxides (NOx) and ozone (O3) within and above snowpack at Summit, Greenland for March-May 2009 and estimates surface exchange of NOx between the snowpack and surface layer in April-May 2009. The model assumes the surface of snowflakes have a Liquid Like Layer (LLL) where aqueous chemistry occurs and interacts with the interstitial air of the snowpack. Model parameters and initialization are physically and chemically representative of snowpack at Summit, Greenland and model results are compared to …
Cross Photoreaction Of Pyruvic And Glyoxylic Acids In Model Aqueous Aerosols,
2014
University of Kentucky
Cross Photoreaction Of Pyruvic And Glyoxylic Acids In Model Aqueous Aerosols, Shasha Xia
Theses and Dissertations--Chemistry
Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. Aerosols from natural and anthropogenic sources can be primary organic aerosols (POA), which are directly emitted to the atmosphere, or secondary organic aerosols (SOA) that are formed from chemical reactions of gas-phase precursors. At variance with the well investigated formation of SOA from gas phase precursors, the chemistry of aqueous SOAs that contribute to the total SOA budget remains unknown. Field measurements have revealed that carboxylic, dicarboxylic and oxocarboxylic acids are abundant species present in SOAs. This thesis …
Salen Aluminum Compounds In The Dealkylation And Detection Of Organophosphates,
2014
University of Kentucky
Salen Aluminum Compounds In The Dealkylation And Detection Of Organophosphates, Rahul R. Butala
Theses and Dissertations--Chemistry
The focus of this dissertation is the use of aluminum Schiff base compounds, Salen(tBu)AlBr (SAB), in the dealkylation and detection of organophosphates (OPs). Three SAB compounds, Salen(tBu)AlBr (1), Salpen(tBu)AlBr (2), and Salophen(tBu)AlBr (3) were used to dealkylate a variety of trialkyl OPs. These reactions lead to unique organic-soluble aluminum phosphate compounds containing six-coordinate aluminum. Examples include [salen(tBu)AlOP(O)(OCH3)2]n (4), [salen(tBu)AlOP(O)(OCH2CH3)2]n (5), [salen(tBu)AlOP(O)(OPh)2]n …
Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms,
2014
University of Kentucky
Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms, Bradley J. Newsome
Theses and Dissertations--Chemistry
Due to their relative chemical stability and ubiquity in the environment, chlorinated organic contaminants such as polychlorinated biphenyls (PCBs) pose significant health risks and enduring remediation challenges. Engineered nanoparticles (NPs) provide a novel platform for sensing/remediation of these toxicants, in addition to the growing use of NPs in many industrial and biomedical applications, but there remains concern for their potential long-term health effects. Research highlighted herein also represents a transdisciplinary approach to address human health challenges associated with exposure to PCBs and NPs. The objectives of this dissertation research are two-fold, 1) to develop effective methods for capture/sensing and remediation …
Wetlands And Greenhouse Gas Fluxes: Causes And Effects Of Climate Change – A Meta-Analysis,
2014
Pomona College
Wetlands And Greenhouse Gas Fluxes: Causes And Effects Of Climate Change – A Meta-Analysis, Robert E. Ventura
Pomona Senior Theses
Climate change is one of the largest problems facing this generation. Anthropogenically caused increases of greenhouse gas emissions is a significant culprit to this problem. Although the obvious problems such as cars, industry, and urbanism garnish a significant amount of the criticism, natural sources such as wetlands are also beginning to contribute to this issue. This is becoming increasingly significant as wetlands shift from being sinks of greenhouse gases to becoming sources as various anthropogenic impacts, including global warming itself, begin to affect the health of the wetlands. The aim of this project is to look at four common types …
Surface Complexation Of Monosubstituted Organoarsenicals On Hematite: Atr-Ftir Investigations,
2014
Wilfrid Laurier University
Surface Complexation Of Monosubstituted Organoarsenicals On Hematite: Atr-Ftir Investigations, Md Abdus Sabur
Theses and Dissertations (Comprehensive)
Little is known about the surface chemistry of organoarsenic compounds with iron-containing materials commonly found in geosorbents and arsenic removal technologies. In this thesis, these organoarsenicals include aliphatic and aromatic arsenicals that historically have been used as herbicides, pesticides and in the poultry feed industry, respectively. Attenuated total internal reflectance Fourier transform infrared spectroscopy has been used to study the surface interactions of organoarsenicals at the molecular level under various environmentally-relevant conditions. Kinetic and thermodynamic parameters extracted from these molecular level experiments provide trends that are not observed in any published bulk experiments. Apparent initial rates of adsorption and desorption …
On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Fall 2013,
2014
University of Denver
On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Fall 2013, Gary A. Bishop, Donald H. Stedman
Fuel Efficiency Automobile Test Publications
No abstract provided.
The Recession Of 2008 And Its Impact On Light-Duty Vehicle Emissions In Three Western Us Cities,
2014
University of Denver
The Recession Of 2008 And Its Impact On Light-Duty Vehicle Emissions In Three Western Us Cities, Gary A. Bishop, Donald H. Stedman
Fuel Efficiency Automobile Test Publications
The global economic recession of 2008 - 2010 severely depressed light-duty vehicle sales in the United States. On-road fleets observed with a remote vehicle exhaust sensor in 2013 at three historical sampling locations in Denver, Los Angeles and Tulsa showed large reductions in the fleet fractions of 2009 model year vehicles of 40%, 38% and 35% respectively when compared to prerecession 2007 levels with the light-duty truck category suffering the largest percentage declines. The fleet fraction for these ~5 year old vehicles is normally reserved for vehicles more than twice their age. This resulted in a significant increase in the …
Feat Math Ii And A Discussion Of Negative Measurements,
2014
University of Denver
Feat Math Ii And A Discussion Of Negative Measurements, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2013,
2014
University of Denver
On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2013, Gary A. Bishop, Donald H. Stedman
Fuel Efficiency Automobile Test Publications
No abstract provided.
Rsd Basics (Presentation),
2014
University of Denver
Rsd Basics (Presentation), Donald H. Stedman, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Heavy Duty Truck Emissions (Presentation),
2014
University of Denver
Heavy Duty Truck Emissions (Presentation), Donald H. Stedman, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Colorado Long Term Light-Duty Vehicle On-Road Emission Trends (Presentation),
2014
University of Denver
Colorado Long Term Light-Duty Vehicle On-Road Emission Trends (Presentation), Gary A. Bishop, Donald H. Stedman
Fuel Efficiency Automobile Test Publications
No abstract provided.
Visible-Light Photocatalyzed Cross-Linking Of Diacetylene Ligands By Quantum Dots To Improve Their Aqueous Colloidal Stability,
2014
University of Arkansas, Fayetteville
Visible-Light Photocatalyzed Cross-Linking Of Diacetylene Ligands By Quantum Dots To Improve Their Aqueous Colloidal Stability, Marion G. Götz, Hiroko Takeuchi, Matthew J. Goldfogel, Julia M. Warren, Brandon D. Fennel, Colin D. Heyes
Chemistry & Biochemistry Faculty Publications and Presentations
Ligand cross-linking is known to improve the colloidal stability of nanoparticles, particularly in aqueous solutions. However, most cross-linking is performed chemically, in which it is difficult to limit interparticle cross-linking, unless performed at low concentrations. Photochemical cross-linking is a promising approach but usually requires ultraviolet (UV) light to initiate. Using such high-energy photons can be harmful to systems in which the ligand–nanoparticle bond is fairly weak, as is the case for the commonly used semiconductor quantum dots (QDs). Here, we introduce a novel approach to cross-link thiolated ligands on QDs by utilizing the photocatalytic activity of QDs upon absorbing visible …
Advances In Understanding The Molecular Composition Of Dissolved Organic Matter And Its Reactivity In The Environment,
2014
Old Dominion University
Advances In Understanding The Molecular Composition Of Dissolved Organic Matter And Its Reactivity In The Environment, Rajaa Mesfioui
Chemistry & Biochemistry Theses & Dissertations
Dissolved organic matter (DOM) is the ultimate product of Earth's systems dynamics. DOM chemical signature is strongly shaped by the interaction among Earth's spheres, such as the atmosphere, the geosphere, the biosphere, and the hydrosphere, but also life and human activity. DOM source, composition, photochemical alteration and availability affect freshwater ecosystems, their carbon and nitrogen fluxes and, thus, the global carbon and nitrogen cycles. The aim of this thesis was to gain an understanding of the molecular composition of DOM and its photochemical and biological reactivity in an environment impacted by anthropogenic disturbance. The York and James River systems within …
Zn(Ii) And Cu(Ii) Adsorption And Retention Onto Iron Oxyhydroxide Nanoparticles: Effects Of Particle Aggregation And Salinity,
2014
Chapman University
Zn(Ii) And Cu(Ii) Adsorption And Retention Onto Iron Oxyhydroxide Nanoparticles: Effects Of Particle Aggregation And Salinity, Rebecca B. Chesne, Christopher S. Kim
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Background: Iron oxyhydroxides are commonly found in natural aqueous systems as nanoscale particles, where they can act as effective sorbents for dissolved metals due to their natural surface reactivity, small size and high surface area. These properties make nanoscale iron oxyhydroxides a relevant option for the remediation of water supplies contaminated with dissolved metals. However, natural geochemical processes, such as changes in ionic strength, pH, and temperature, can cause these particles to aggregate, thus affecting their sorption capabilities and remediation potential. Other environmental parameters such as increasing salinity may also impact metal retention, e. g. when particles are transported …
Traceability Implementation In Organic Farming: Case Study, Chamomile Tea Production,
2014
[email protected]
Traceability Implementation In Organic Farming: Case Study, Chamomile Tea Production, Shaima Ibrahim
Theses and Dissertations
Implementing a traceability plan in an herbal production plant is a complex task. In this study an attempt to integrate food safety, quality and traceability through the different stages of the organic German Chamomile (Matricaria recutita) production chain was made. First, all the current relevant international laws, regulations and standards regarding traceability, safety and quality, with emphasis on how and why they are necessary for any food production chain, were set forward. Second, physico-chemical and microbiological analyses were run throughout the different processing stages of production, for four different Chamomile batches produced over the same season using the same farming …
Solar Energy Conversion And Control Using Organic Photovoltaic Cells,
2013
Western Kentucky University
Solar Energy Conversion And Control Using Organic Photovoltaic Cells, Kurt Wade Woods
Masters Theses & Specialist Projects
Organic photovoltaic (OPV) cells are advanced, newly emerging technologies that are lightweight, mechanically flexible devices with highthroughput processes from low cost material in a variety of colors. Rathnayake et al. of Western Kentucky University have developed a nanostructure-based OPV cell. Presented in this thesis is a model and simulation of a generalized PV powered system that can predict the performance of solar arrays in various environmental conditions. The simulation has been carried out in Matlab/Simulink, and upon entering the cell’s parameters, it provides key electrical characteristics such as the cell’s I-V curve and efficiency information. The total system that is …
The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca,
2013
California Polytechnic State University, San Luis Obispo
The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca, Mark D. Gormley
Master's Theses
Scotts Creek Marsh (SCM) is a small coastal wetland ecosystem in Davenport, CA. The vegetation of SCM is dominated by three halophytic zones comprised of saltgrass, salt rush, cattails. The objectives of the study were (i) to investigate the variables that influence the zoning of the three dominant halophyte communities in SCM and (ii) to the test the effectiveness of Indicator of Reduction in Soil (IRIS) tubes to indicate the reduction of S. The study examined the following parameters from April 6 to July 21, 2013: (i) the HGM of Scotts Creek Marsh, (ii) soil oxidation and reduction (redox) conditions, …
