Chemistry Commons^™

Photooxidation Reactions Of Small-Chain Methyl Esters, Aerosol Photoelectron Spectroscopy, And The Photodissociation Of Ethylenediamine, Giel Muller

Master's Theses

Research conducted at the University of San Francisco is presented within this masters thesis, including the Cl-initiated photooxidation reactions of methyl propanoate, methyl butanoate, and methyl valerate (pentanoate), the aerosol photoelectron spectroscopy of isoprene and gamma-valerolactone, and the TPEPICO investigation of ethylenediamine. Experiments were conducted at the Lawrence Berkeley National Lab Advanced Light Source (ALS), the National Synchrotron Radiation Research Center in Hsinchu City (NSRRC), and the University of Stockton in California, respectively.

Chemical And Electronic Structure Of Surfaces And Interfaces In Cadmium Telluride Based Photovoltaic Devices, Douglas Arthur Duncan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The surface and interface properties are of the upmost importance in the understanding, optimization, and application for photovoltaic devices. Often the chemical, electronic, and morphological properties of the films are empirically optimized, however when progress slows, a fundamental understanding of these properties can lead to breakthroughs. In this work, surfaces and interfaces of solar cell-relevant films are probed with a repertoire of X-ray analytical and microanalysis techniques including X-ray photoelectron (XPS), X-ray excited Auger electron (XAES), X-ray emission (XES) spectroscopies, and atomic force (AFM) and scanning electron (SEM) microscopies.

Silicon-based devices currently dominate the solar market, which is rather inflexible …

The Effect Of Disturbance And Freshwater Availability On Lower Florida Keys’ Coastal Forest Dynamics, Danielle E. Ogurcak

FIU Electronic Theses and Dissertations

Coastal forest retreat in the Florida Keys during the 20^th century has been attributed to a combination of sea level rise and hurricane storm surge impacts, but the interactions between these two disturbances leading to forest decline are not well understood. The goal of my research was to assess their effects over a period spanning more than two decades, and to examine the relationships between these press and pulse disturbances and freshwater availability in pine rockland, hardwood hammock, and supratidal scrub communities. Impacts and recovery from two storm surges, Hurricanes Georges (1998) and Wilma (2005), were assessed with satellite-derived …

Evaluation Of Veterinary Pharmaceuticals And Iodine For Use As A Groundwater Tracer In Hydrologic Investigation Of Contamination Related To Dairy Cattle Operations, Larry Boot Pierce, Honglin Shi

Sinkhole Conference 2015

Standard groundwater tracers such as Rhodamine WT, Fluorescein, Eosin and Tinopal CBX effectively provide a snapshot of hydrological conditions over a brief period of time and in a tightly controlled setting. However, in complex environmental situations with multiple potential sources, groundwater hydrologists are often seeking groundwater tracers that have extended longevity in the natural environment and the ability to directly pinpoint source locations. After reviewing operations of the nearby dairy it was determined that emerging contaminants, specifically two bovine veterinary pharmaceuticals (antibiotics), cephapirin sodium (CEPNa) and cephapirin benzathine (CEPB), and a sanitation agent, elemental Iodine (I) may have potential as …

Using Nitrate, Chloride, Sodium, And Sulfate To Calculate Groundwater Age, Kimm Crawford, Terry Lee

Sinkhole Conference 2015

Regression analysis is used to identify monotonic trends to assign water age using ion data from two large well water databases from southeast Minnesota (SE MN). Nitrate (NO3-N), chloride (Cl), sodium (Na), and sulfate (SO4) ions in the commonly used aquifers in SE MN can be used as groundwater tracers since they are either entirely or partly anthropogenic in their sources, their loading occurs on a regional scale, and they are almost entirely conserved. Ion concentrations over time are used to establish six trend patterns. Two patterns are unchanging (background and stable above background), and four are changing (linear up, …

Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman

Chemistry Faculty Publications

Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air–solid interface under variable relative humidity (RH = 0–90%). The maximum reactive uptake coefficient of O₃(g) by catechol γ_O3 = (7.49 ± 0.35) × 10^–6 occurs for …

Assessing The Impacts Of Inorganic And Organic Fertilizer On Crop Performance Under A Microirrigation-Plastic Mulch Regime, Niyi S. Omidire, Raymon Shange, Victor Khan, Russell Bean, Jewel Bean

Professional Agricultural Workers Journal

Abstract

This study was conducted at S & B Farm located in Eufaula, AL in 2014. The treatments were Inorganic fertilizer/“Farmer’s Mix” (NPK 13:13:13 + ammonium nitrate mixed in 3:1 ratio); Inorganic fertilizer/“Farmer’s Mix” (NPK 13:13:13 + ammonium nitrate mixed in 3:1 ratio + Bio-grow) plus microbe mix; and Organic Fertilizer – Mighty Grow (4-3-4) with a microbe mix. All fertilizers were applied prior to mulch application after which the following crops squash (Cucurbita pepo L.), cucumber (Cucumis sativus L.), and okra (Abelmoschus esculentus L. Moench) were directly seeded in a complete randomized …

Influence Of Ph And Bulk Density On Carbon Dioxide Efflux In Three Urban Wetland Types, Christopher Chappell, Andra Johnson

Professional Agricultural Workers Journal

Abstract

The aim of this study was to understand soil carbon dioxide (CO₂) efflux of three different urban wetlands and how pH and bulk density relate to soil CO₂ efflux of each wetland. The three wetlands were bottomland, upland, and shrub/scrub. The study was conducted over a twenty week period using the Li-Cor 8100 “closed chamber” method to measure soil CO₂ efflux. The findings show that the bottomland wetland efflux was significantly higher than the shrub/scrub and upland wetland. The pH of shrub/scrub was significantly higher than the upland. The bulk density of the bottomland was …

Evaluating Sub-Lethal Effects Of Orchard-Applied Pyrethroids Using Video-Tracking Software To Quantify Honey Bee Behaviors, Erin M. Ingram, Julie Augustin, Marion D. Ellis, Blair Siegfried

Department of Entomology: Faculty Publications

Managed honey bee, Apis mellifera L., colonies are contracted to pollinate fruit and nut orchards improving crop quality and yield. Colonies placed in orchards are potentially exposed to pyrethroid insecticides used for broad-spectrum pest control. Pyrethroids have been reported to pose minimal risk to bees due to their low application rates in the field and putative repellent properties. This repellency is believed to alter foraging behavior with the benefit of preventing bees from encountering a lethal dose in the field. However, sub-lethal exposure to pyrethroids may adversely impact bee behavior potentially resulting in social dysfunction or disruption of foraging.

This …

Comparative Sorption Of Methylene Blue Onto Hydrophobic Clays, Alvaro D. Sponza, Natalia J. Fernandez, David Yang, Karla A. Ortiz, Abel E. Navarro

Publications and Research

Chemical modifications of clay to remove methylene blue (MB) from aqueous solutions at room temperature were compared. Natural bentonite (NC) was modified by cation exchange with hexadecyltrimethylammonium chloride (HC), bencyltriethylammonium chloride (BC), and tetramethylammonium chloride (TC) to reverse the surface polarity of the hydrophilic bentonite. The adsorption of MB was studied and fitted by the adsorption theories of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin. Equilibrium parameters were calculated, indicating that chemical modification did not improve the adsorption, due to the electrostatic adsorption mechanism. Specific surface area was determined, reporting the following trend: NC > TC > BC > HC. Isotherms show that TC is …

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected …

Mangiferin As A Biomarker For Mango Anthracnose Resistance, Herma Pierre

FIU Electronic Theses and Dissertations

Mangos (Mangifera indica L.) are tropical/subtropical fruits belonging to the plant family Anacardiaceae. Anthracnose is the most deleterious disease of mango both in the field and during postharvest handling. It is most commonly caused by the Colletotrichum gloeosporioides complex. Mangiferin, a xanthanoid compound found in at least twelve plant families worldwide (Luo et al., 2012), is present in large amounts of the leaves and edible mangos. Even though this compound plays a pivotal role in the plant’s defense against biotic and abiotic stressors, no correlations been made between the compound and mango anthracnose resistance.

Mangos were collected, grouped …

Synthesis Of Palladium And Palladium-Copper Nanostructures As Electrocatalysts, Haibin Wu

Graduate Theses and Dissertations

Pd and its alloys are alternatives of Pt as promising catalysts and electrocatalysts for many reactions. Size controlled synthesis of nanoparticles remains a major research subject, since smaller size particles show better catalytic performance. In this work, we developed a modified chemical wet method to prepare Pd and Pd-Cu nanostructures with uniform small size. Different sizes and shapes of Pd nanostructures were successfully synthesized by using the two reducing agents (i.e., L-ascorbyl-6-palmitate or phenylphosphinic acid). The reducing agents play a role to control the final morphologies and sizes of particles. The use of L-ascorbyl-6-palmitate favors to form irregular branch shapes …

Artificial Maturation Studies Of Polymethylenic Plant Biopolymers: Investigating The Chemical Alterations From Plant Material To Coal, Blaine Elizabeth Hartman

Chemistry & Biochemistry Theses & Dissertations

The thermal maturation and alternation of vascular plant material into coals and as expelled petroleum-like compounds is the main focus of this dissertation. Utilizing artificial maturation studies, like hydrothermal liquefaction, yields useful information regarding how plant material is preserved in coals and the potential certain plant biopolymers possess to generate liquid fuels is acquired. The studies within this dissertation focus on utilizing the aliphatic biopolymers, cutin, cutan, and suberan, found in the epidermis of certain plants. These biopolymers contain minimal amounts of heteroatoms and are comprised of long polymethylenic chains, which are desirable characteristics in generating bio-oils. Additionally, understanding the …

Kinetic Modeling Of Catalytic Aerogels, Yi Cao

Honors Theses

As pollution becomes an increasing concern globally, strict regulations have been set on vehicle pollutant emissions. The three-way catalytic converter is capable of converting toxic emissions such as carbon monoxide, unburned hydrocarbons and nitrogen oxides to less hazardous waste such as carbon dioxide, water, and nitrogen. Current catalysts employ platinum group metals, which are expensive and environmentally damaging to mine. Catalytically-active aerogels such as Co-Al, Cu-Al and V-Al aerogels have shown promise as alternatives to these metals. The work presented here adapts and extends a global kinetic model which predicts the conversion of hydrocarbons and carbon monoxide on platinum catalyst …

Evaluation Of The Feasibility Of Struvite Precipitation From Domestic Wastewater As An Alternative Phosphorus Fertilizer Resource, Amanda R. Bird

Master's Projects and Capstones

Finite phosphate rock ore reserves are estimated to be exhausted in 100 to 150 years. Phosphate rock ore is the single global source material for phosphorus fertilizer production. Once these reserves are gone, agricultural production will be negatively impacted. There are currently no alternative phosphorus resources. However, phosphorus concentrations present in human excrement traveling through domestic wastewater treatment facilities is being disposed of directly to the environment, often resulting in pollution problems. Recovering phosphorus from wastewater with struvite precipitation systems at wastewater treatment plants can alleviate future phosphorus scarcities. Evaluation of phosphorus recovery through struvite precipitation at wastewater treatment plants …

Characterization Of Cellulase Enzyme Inhibitors Formed During The Chemical Pretreatments Of Rice Straw, Kalavathy Rajan

Graduate Theses and Dissertations

Production of fuels and chemicals from a renewable and inexpensive resource such as lignocellulosic biomass is a lucrative and sustainable option for the advanced biofuel and bio-based chemical platform. Agricultural residues constitute the bulk of potential feedstock available for cellulosic fuel production. On a global scale, rice straw is the largest source of agricultural residues and is therefore an ideal crop model for biomass deconstruction studies. Lignocellulosic biofuel production involves the processes of biomass conditioning, enzymatic saccharification, microbial fermentation and ethanol distillation, and one of the major factors affecting its techno-economic feasibility is the biomass recalcitrance to enzymatic saccharification. Preconditioning …

Reaping The Benefits Of Conservation Tillage: Implications Of Increased Soil Organic Matter And Aggregation In Surface Soils, Kenna Elizabeth Rewcastle

Chancellor’s Honors Program Projects

No abstract provided.

Characterizing Groundwater Ch4 And 222rn In Relation To Hydraulic Fracturing And Other Environmental Processes In Letcher County, Ky, St. Thomas Majeau Ledoux

Masters Theses

Hydraulic fracturing of shale deposits has greatly increased the productivity of the natural gas industry by allowing it to exploit previously inaccessible reservoirs. However, previous research has demonstrated that this practice can contaminate shallow aquifers with CH₄ [methane] from deeper formations. This study compares concentrations and isotope compositions of CH₄ sampled from domestic groundwater wells in Letcher County, Kentucky in order to characterize its occurrence and origins in relation to neighboring hydraulically fractured natural gas wells. Additionally, this study tests the reliability of ²²²Rn [radon] as an alternative tracer to CH₄ in identifying processes of gas …

On The Influence Of Ionic Strength On Radium And Strontium Sorption To Sandy Loam Soils, Brian A. Powell, Todd Miller, Daniel I. Kaplan

Journal of the South Carolina Academy of Science

Models which can estimate environmental transport of radioactive contaminants in natural and engineered systems are required to 1) deploy effective remediation strategies for contaminated sites, 2) design waste repositories for future waste streams, and 3) ensure protection of human and environmental health in all cases. These models require accurate transport parameters in order to correctly predict how these contaminants will move in the subsurface. This work aimed to determine more accurately the distribution coefficients for radium and strontium sorption to Savannah River Site (SRS) soils. Radium and strontium sorption to the soils was found to be highly dependent upon ionic …

Advanced Oxidation Processes Of Problematic Toxin And Water Contaminants: Cylindrospermopsin, Iopamidol, 4-Methylcyclohexane Methanol And Propylene Glycol Phenyl Ether, Cen Zhao

FIU Electronic Theses and Dissertations

The occurrences of cyanotoxin and organic contaminants threaten drinking water sources and are a serious human health and environmental concern. The control of these problematic contaminants and the remediation of the associated contaminants are critical for ensuring safe drinking water to significant populations. Advanced oxidation processes (AOPs) have received considerable attention as a potential water treatment for various pollutants. In this dissertation, advanced oxidative degradation of four problematic water toxic contaminants (CYN, iopamidol, 4-methylcyclohexane methanol and propylene glycol phenyl ether) were studied to develop the fundamental understanding required to assess AOPs as a potential water treatment process.

UV and visible …

Volume 07, Rachel C. Lombardi, Ben Osterhout, Lindsay Graybill, Rebecca E. Dey, Skyler T. Carpenter, Emma Beckett, Jason Ware, Mollie Andrews, James Bates, Landon Cooper, Tiffani Jeffries, Maria Wheaton, Dallas Price, Laura Kahler, Sarah Charlton, Anna Bultrowicz, Emily Spittle, Erin Godwin, Eamon Brokenbrough

Incite: The Journal of Undergraduate Scholarship

Introduction from Interim Dean Dr. Jennifer Apperson

Spatial Analysis of Potential Risk Factors Associated with Addition of Atlantic Coast Pipeline Through Virginia by Rachel C. Lombardi

"Delicate Matters with No Speaking," "Hope and Nothing," "Mono Duality" by Ben Osterhout

"Connect" Graphic Design Senior Project by Lindsay Graybill

Phenolic Acids in Brassicaceae Plants: Ovipositional Stimulants or Deterrents for Cabbage White Butterfly, Pieris Rapae? by Rebecca E. Dey And Skyler T. Carpenter

"Abecedarian Cards" by Emma Beckett, Jason Ware, And Mollie Andrews

Helvetica: A Type Specimen Book by James Bates, Landon Cooper, Tiffani Jeffries, And Maria Wheaton

“Things Left Behind” by Dallas …

Blue Carbon In Coastal Freshwater/Brackish Marshes On The Barrier Islands Of Virginia: Belowground Carbon Dynamics, Nathan M. Sedghi

Biological Sciences Theses & Dissertations

Some coastal ecosystems sequester substantially more carbon (blue carbon) than land locked systems due to high net primary production and deposition associated with oceanic influences. Most blue carbon research has focused on mangroves, seagrass beds, and salt marshes. Studies on blue carbon potential of coastal freshwater marshes are less common. Barrier islands frequently flood, with seawater reaching interior ecosystems. I examined brackish/freshwater marshes on Virginia barrier islands for possible roles as blue carbon systems. I studied four interior marshes on Hog Island, which varied in proximity to a direct overwash path and protection by a trail berm that divides northern …

Blue Carbon In Freshwater / Brackish Marshes On The Barrier Islands Of Virginia Aboveground Net Primary Productivity And Carbon Pools, Emily Caitlin Adams

Biological Sciences Theses & Dissertations

"Blue carbon" is a relatively new concept describing carbon distributed tidally and sequestered via net production within coastal ecosystems, including seagrass beds, mangrove forests, and salt-water marshes. These systems sequester carbon at least 10 times faster than terrestrial systems. Fresh to brackish wetlands that receive irregular tidal influence due to overwash and storm events have not been typically studied as blue carbon systems. My objective was to quantify carbon pools within four interdunal fresh to brackish marshes on Hog Island, Virginia to determine their blue carbon potential. Marshes 1 and 2 were farthest from the ocean, below and above a …

Tb195: Element Concentrations In Maine Forest Vegetation And Soils, Chandra J. Mcgee, Ivan J. Fernandez, Stephen A. Norton, Constance S. Stubbs

Ivan J. Fernandez

Bioaccumulation of trace metals in plant tissues can present a health risk to wildlife, and potentially to humans. The Passamaquoddy Tribe in Maine was concerned about health risks of cadmium (Cd) because of a health advisory for moose liver and kidney consumption due to high Cd levels. In addition to Cd, this study evaluated concentrations of aluminum (Al), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), nickel (Ni), phosphorus (P), lead (Pb), and zinc (Zn) in four common terrestrial moose-browse species, associated forest soils, and two species of aquatic vegetation on Passamaquoddy tribal land in eastern …

Visible Light-Induced Enhanced Photoelectrochemical And Photocatalytic Studies Of Gold Decorated Sno2 Nanostructures, Mohammad Mansoob Khan Dr, S. A. Ansari, M. E. Khan, M. O. Ansari, B. K. Min, M. H. Cho

Dr. Mohammad Mansoob Khan

This paper reports a novel one-pot biogenic synthesis of Au–SnO2 nanocomposite using electrochemically active biofilm. The synthesis, morphology and structure of the as-synthesized Au–SnO2 nanocomposite were in-depth studied and confirmed by UV-vis spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It was observed that the SnO2 surface was decorated homogeneously with Au nanoparticles. The photoelectrochemical behavior of the Au–SnO2 nanocomposite was examined by cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry in the dark and under visible light irradiation. Visible light-induced photoelectrochemical studies confirmed that the Au–SnO2 nanocomposite had enhanced activities compared …

Changes Of Soil Biogeochemistry Under Native And Exotic Plants Species, Yujie Hua

FIU Electronic Theses and Dissertations

Invasive plant species are major threats to the biodiversity and ecosystem stability. The purpose of this study is to understand the impacts of invasive plants on soil nutrient cycling and ecological functions. Soil samples were collected from rhizosphere and non-rhizosphere of both native and exotic plants from three genera, Lantana, Ficus and Schinus, at Tree Tops Park in South Florida, USA. Experimental results showed that the cultivable bacterial population in the soil under Brazilian pepper (invasive Schinus) was approximately ten times greater than all other plants. Also, Brazilian pepper lived under conditions of significantly lower available phosphorus …

Comparing Three Methods For Estimating Ozone Depleting Substance Substitute Greenhouse Gases: Case Study Of The New York City Region, Wallace A. Murray Iii

Theses and Dissertations

This thesis evaluates the United States Environmental Protection Agency (EPA) method for estimating emissions from one source, Ozone Depleting Substances Substitutes (ODS substitutes) by comparing results for the New York City Metropolitan Statistical Area (NYC-MSA) with results from two other methodologies. The EPA’s method utilizes population data and GDP data to estimate and geographically allocate emissions, with little regard for the geographies of industrial activity. The two alternative methods use data for industrial employment and activity to provide results for comparison and perhaps a more accurate accounting and allocation of emissions throughout the NYC-MSA.

The Health Risks Of Chemicals In Personal Care Products And Their Fate In The Environment, Lisa Paulsen

Chemistry Honors Papers

Personal care products are everyday consumer products used to cleanse, enhance, or alter the appearance of the body, including, but not limited to, shampoos, body washes, lotions, and cosmetics. The regulations and safety information surrounding personal care products are severely lacking. The laws regulating the environmental fate of these chemicals and the harmful effects they can have on environmental ecosystems or organisms that are exposed to them are even more limited. However, studies have shown that the chemicals can have a dizzying array of health risks, including diseases on the rise in human populations such as diabetes, obesity, autism, ADHD, …

Investigation Of Natural Perchlorate Levels In Antarctic Snow In Relation To The Ozone Hole, Thomas Crawford, Alexandria Kub, Han Vid Cho

The Journal of Undergraduate Research

Snow samples collected from the West Antarctic Ice Sheet Divide in January 2013 were analyzed for perchlorate concentrations to determine a possible seasonal variation. These samples were dated for the years 2007 through 2012 using annual variations in sulfate concentration as determined by an ion chromatography (IC) method. Perchlorate concentrations in the samples were measured with an IC instrument paired with tandem mass spectrometry detection. The concentration data show that perchlorate reached an annual maximum concentration in the austral autumn seasons, assuming that snowfall was relatively constant throughout the course of each year. Comparison with published total column ozone density …