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Articles 511 - 540 of 1492

Full-Text Articles in Chemistry

Heavy Metals In Particulate Matter In Spokane County, Delaney M. White May 2020

Heavy Metals In Particulate Matter In Spokane County, Delaney M. White

2020 Symposium Posters

Heavy metals in particulate matter (e.g., dust) have multiple negative health ramifications for humans including cancer, infertility, and reduced lung function. The Spokane Regional Clean Air Agency (SRCAA) has seven air quality monitoring stations around Spokane County to measure total levels of PM2.5 (particles with a diameter less than 2.5 micrometers) and PM10 (particles with a diameter less than 10 micrometers). For comparison, the width of a human hair is between 50 and 70 micrometers. The objective of this research is to examine the heavy metal composition of the particulate matter including elements such as lead, copper, and zinc. We …

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Synthesis, Characterization, And Investigation Of Metal Ion Quenching In Fluorescent Carbon Dot Surrogates For Particulate Matter Black Carbon And Evaluation Of Cellular Health Effects Due To The Surrogate Materials, Christopher Lee Sumner Jr May 2020

Synthesis, Characterization, And Investigation Of Metal Ion Quenching In Fluorescent Carbon Dot Surrogates For Particulate Matter Black Carbon And Evaluation Of Cellular Health Effects Due To The Surrogate Materials, Christopher Lee Sumner Jr

LSU Doctoral Dissertations

Black carbon (BC) is an environmental pollutant of particular concern to many international organizations for both its health effects and environmental effects. Probing health effects of BC as produced in the environment is difficult due to the complex nature of environmental pollutants found in their naturally occurring state. Fluorescent carbon dots (FCDs) were chosen to be used as a surrogate for BC. In the process of examining FCDs and their behavior as surrogates, information was gained on the health effects and behavior of FCDs as a class of nanomaterials for cell and tissue studies, which is outlined in this dissertation. …

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Karena Mckinney: Mapping A Clearer Picture Of Air Pollution's Effects, Christina Nunez May 2020

Karena Mckinney: Mapping A Clearer Picture Of Air Pollution's Effects, Christina Nunez

Colby Magazine

"If we want to control air quality and address climate change, the solution won't involve fiddling with nature's emissions-it will be about cleaning up man-made ones." -Karena McKinney, associate professor of atmospheric chemistry

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Massive Peatland Carbon Banks Vulnerable To Rising Temperatures, A. M. Hopple, R. M. Wilson, M. Kolton, Cassandra A. Zalman, J. P. Chanton, J. Kostka, P. J. Hanson, Jason K. Keller, S. D. Bridgham May 2020

Massive Peatland Carbon Banks Vulnerable To Rising Temperatures, A. M. Hopple, R. M. Wilson, M. Kolton, Cassandra A. Zalman, J. P. Chanton, J. Kostka, P. J. Hanson, Jason K. Keller, S. D. Bridgham

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands contain one-third of the world’s soil carbon (C). If destabilized, decomposition of this vast C bank could accelerate climate warming; however, the likelihood of this outcome remains unknown. Here, we examine peatland C stability through five years of whole-ecosystem warming and two years of elevated atmospheric carbon dioxide concentrations (eCO2). Warming exponentially increased methane (CH4) emissions and enhanced CH4 production rates throughout the entire soil profile; although surface CH4 production rates remain much greater than those at depth. Additionally, older deeper C sources played a larger role in decomposition following prolonged warming. Most …

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Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa May 2020

Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Primary productivity (PP) has been recently investigated using remote sensing-based models over quite limited geographical areas of the Red Sea. This work sheds light on how phytoplankton and primary production would react to the effects of global warming in the extreme environment of the Red Sea and, hence, illuminates how similar regions may behave in the context of climate variability. study focuses on using satellite observations to conduct an intercomparison of three net primary production (NPP) models--the vertically generalized production model (VGPM), the Eppley-VGPM, and the carbon-based production model (CbPM)--produced over the Red Sea domain for the 1998-2018 time period. …

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Behavior Of Iron Species And Free Radicals In Ambient Pm2.5 And Pm Surrogates, Cholena Russo Ren May 2020

Behavior Of Iron Species And Free Radicals In Ambient Pm2.5 And Pm Surrogates, Cholena Russo Ren

LSU Doctoral Dissertations

Air pollution, consisting of ambient particulate matter (PM), has been a rising health concern to the public. PM contains free radicals and have been known to damage human cells; however, their free radical chemistry is not well understood. This study utilized various vacuum and/or heat treatments to study free radical behavior in PM2.5 (particulate matter with an aerodynamic diameter of 2.5 mm or less) and PM surrogates and simulated sunlight effects on PM2.5. To mimic PM, iron-silica catalysts (i.e. PM surrogates) were synthesized and real-world ambient PM2.5 was selected. The free radicals in PM2.5 …

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In Situ Plant Uptake Of Excess Nutrients And Consequential Alteration Of Rhizosphere Dynamics, Srusti Maddala May 2020

In Situ Plant Uptake Of Excess Nutrients And Consequential Alteration Of Rhizosphere Dynamics, Srusti Maddala

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The use of phytoremediation in ecological remediation projects has numerous benefits including soil stabilization and nutrient uptake. Recently, microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has been recognized as a candidate for monitoring chemical changes in the rhizosphere. The real-time, in situ data it provides about nutrient diffusion may improve the management and success of restoration projects. Therefore, the objective of this study was to employ the technique of microdialysis in the novel application of quantifying the diffusive flux of inorganic nitrogen compounds in the rhizosphere of native plants of Arkansas. The microdialysis technique was first optimized …

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Improving Biodiesel Through Pyrolysis: Direct Dynamics Investigations Into Thermal Decomposition Of Methyl Linoleate, Michael Bakker May 2020

Improving Biodiesel Through Pyrolysis: Direct Dynamics Investigations Into Thermal Decomposition Of Methyl Linoleate, Michael Bakker

Graduate Theses/Dissertations

Dependence on petroleum and petrochemical products is unsustainable as it is both a finite resource and environmentally hazardous. Biodiesel is a proposed alternative, but has complications including possessing poor cold weather operability and lacking the ability to supplement other petrochemical products (e.g., ethylene, hexane, etc.) relied upon in society. Pyrolysis of biodiesel has demonstrated the formation of smaller hydrocarbons comprising many of these petrochemical products. Our aim is to computationally simulate the pyrolysis of methyl linoleate, the most prevalent component in biodiesel formed in the US (from soybean). We make use of unimolecular direct dynamics describing intramolecular processes, introducing Temperature …

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Geochemical Tracers Of Arctic Ocean Processes: A Study Of Gallium, Barium, And Vanadium, Laura M. Whitmore May 2020

Geochemical Tracers Of Arctic Ocean Processes: A Study Of Gallium, Barium, And Vanadium, Laura M. Whitmore

Dissertations

The Arctic Ocean is linked to the global oceans and climate through its connectivity with the North Atlantic Ocean and the regional thermohaline deep water formation sites. It’s also a region undergoing rapid environmental change. To inform the community of potential changes in geochemical and biogeochemical cycles, this dissertation addresses three dissolved geochemical tracers (gallium, barium, and vanadium) as indicators of Arctic Ocean processes. Gallium is tested as a replacement for nutrient-type tracers in an effort to deconvolve Pacific and Atlantic derived waters in the Arctic Ocean basins. These water masses carry different heat and salt content and can influence …

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Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro May 2020

Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro

Honors Scholar Theses

Cancer is a disease that stems from genomic errors that are not corrected properly by cellular repair mechanisms. Errors are more likely to form when organisms are subjected to DNA damage by mutagenic compounds. 1-Nitropyrene, a nitrated polycyclic aromatic hydrocarbon (nitro-PAH), has been shown to be a potent mutagen that causes cancer. Nitro-PAHs can arise from diesel exhaust products in the environment. Out of all nitro-PAHs, 1-nitropyrene is found in largest quantities in the environment. This poses a great need to study its effects biochemically in order to address its toxicity in DNA. Other nitropyrene derivatives, including 1,6-dinitropyrene and 1,8-dinitropyrene, …

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Mesoporous Adsorbents For Perfluorinated Compounds, Bertha Lotsi May 2020

Mesoporous Adsorbents For Perfluorinated Compounds, Bertha Lotsi

Electronic Theses and Dissertations

Effective adsorbents for polyfluorinated compounds (PFCs) were successfully prepared. And they were tested in the adsorption of perfluorooctanoic and perfluorooctanesulfonic acids. Bridged silsesquioxanes containing secondary and tertiary amino groups were synthesized by sol-gel condensation of bis[3-(trimethoxysilyl)propyl]amine and bis[3-(methylamino)propyl]-trimethoxysilane in acidic media with surfactants. Obtained materials are mesoporous with a high BET surface area. They combine high structural stability with a high concentration of surface amino groups serving as adsorption sites. Batch adsorption tests demonstrated their extremely high adsorption capacity on PFCs: in some experiments, it reached up to 88% of the adsorbent weight. Adsorption of PFCs changed the surfaces of …

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Immobilization Of Phosphotungstic Acid On Silica Surface For Catalytic Alkylation Of Aromatic Compounds, Anastasia Kuvayskaya May 2020

Immobilization Of Phosphotungstic Acid On Silica Surface For Catalytic Alkylation Of Aromatic Compounds, Anastasia Kuvayskaya

Electronic Theses and Dissertations

Superacidic mesoporous materials containing covalently embedded PTA were synthesized by sol-gel method. Tetraethyl orthosilicate (TEOS) and phosphotungstic acid (PTA) were used as precursors in the synthesis, ionic and nonionic surfactants were used as pore-forming agents, the reaction proceeded in acidic media. TEM images revealed mesoporous structure with embedded PTA clusters. FT-IR spectra of obtained materials contained characteristic bands of PTA at 957 cm-1. Synthesized catalysts had high BET surface area and high concentration of acidic sites. Alkylation of 1,3,5-trimethylbenzene by 1-decene demonstrated high catalytic activity. The catalyst obtained with Pluronic P123 as a template was the most effective and resulted …

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Green Synthesis Of Reduced Graphene Oxide For Efficient Adsorption-Photocatalysis Studies In Methylene Blue Dye Degradation, Ling Er Valerie Siong May 2020

Green Synthesis Of Reduced Graphene Oxide For Efficient Adsorption-Photocatalysis Studies In Methylene Blue Dye Degradation, Ling Er Valerie Siong

Student Works (2020-2029)

Dyes are one of the major components of industrial effluents. Owing to the complex structures of these toxic organic compounds, the removal of dyes from effluents possesses a great challenge in wastewater treatment. In order to tackle this issue, one of the effective methods is to remove dyes via the combination of adsorption and photocatalysis processes. In the present work, reduced graphene oxide (rGO) was fabricated from graphene oxide (GO) by using an environmentally friendly solvothermal approach, whereby ethanol was employed as a non-toxic reductant. In order to investigate the formation of rGO, the reduction of GO was carried out …

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Spectroscopic And Computational Studies Of The Agricultural Active Ingredient Dicamba, James Johnson Apr 2020

Spectroscopic And Computational Studies Of The Agricultural Active Ingredient Dicamba, James Johnson

Honors Theses

3,6-dichloro-2-methoxy benzoic acid, more commonly known as Dicamba, is the active ingredient in an array of pesticides used on farmlands across the globe. Dicamba’s mode of action works by mimicking the plant hormone auxin, which is synonymous to growth hormones in mammals. The mimicking of auxin results in excessive elongation and growing, which is eventually fatal for plants when the rate of growth can no longer be sustained. Dicamba has risen in prominence in recent years due to drift damage as a result of Dicamba’s high volatility. Having the ability to identify Dicamba is crucial for the agricultural industry. The …

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An Innovative "Green" Suzuki Coupling Reaction For The Crl-232 Lab, James W. Wheeler, David Dehm Apr 2020

An Innovative "Green" Suzuki Coupling Reaction For The Crl-232 Lab, James W. Wheeler, David Dehm

Chemistry Student Work

A major objective of “Green Chemistry” is to provide a more modern chemical experience in the laboratory along with reducing the amount of waste generated and make the lab safer for our students. The latest effort is the continuance to update the chemical reactions in the DHE 232 Organic Chemistry Lab by employing a “water-based” Suzuki Coupling Reaction. The 2010 Nobel prize was awarded to Heck, Negishi, and Suzuki for the palladium-catalyzed cross coupling reaction. This reaction has gained wide acceptance in industry where it is used in large scale reactions to make drugs (naproxen, 5-HT1a Agonist), agricultural chemicals (Boscalid® …

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154— Alfalfa Hay As Non-Human Feedstock For Second Generation Biofuels: Hope Or Hoax? Part Ii, Arianna Soriano, Sofia Kostrinsky, Barnabas Gikonyo Apr 2020

154— Alfalfa Hay As Non-Human Feedstock For Second Generation Biofuels: Hope Or Hoax? Part Ii, Arianna Soriano, Sofia Kostrinsky, Barnabas Gikonyo

GREAT Day Posters

The excessive use of fossil fuels has negatively impacted the environment because of greenhouse gas emissions. Researchers are now searching for ways to counterbalance the damage which has been done to the Earth after centuries of greenhouse gas emissions. Potential alternatives to fossil fuels include biofuels, an overlooked and cost-effective source of energy. Many efforts have been focused on the production of first-generation biofuels, fuels attained from human food sources, such as corn. First-generation biofuels have been linked to the increase in food prices, which is a problem because it negatively impacts many developing countries. Our research is geared towards …

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183— Cannabis Sativa: Pretreatment And Fiber Content Analysis, Dina Bú, Arianna Soriano, Sofia Kostrinsky, Sarah Schmidlin, Barnabas Gikonyo Apr 2020

183— Cannabis Sativa: Pretreatment And Fiber Content Analysis, Dina Bú, Arianna Soriano, Sofia Kostrinsky, Sarah Schmidlin, Barnabas Gikonyo

GREAT Day Posters

Cannabis Sativa commonly known as hemp, is one of the fastest growing plants whose refined products have immense commercial value. Refined hemp is included in various products: biofuels, biodegradable plastics, textiles, dietary supplements, paper, clothing and much more. Hemp fibers are also used in construction and manufacturing applications as a way to strengthen composite products. These qualities make hemp a high yielding, sustainable, and environmentally friendly crop with the potential to yield valuable raw materials for a large number of applications. Our research evaluates the pretreatment of hemp and the comparative analysis of the fiber content thereof. Our goal is …

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385— Optimizing Nitrogen Concentrations To Maximize Lipid Yields For Biodiesel Production, Wady Jacoby, Daria Zhogina, Pavel Ananev, Lauren Saggese, Max Muller, Barnabas Gikonyo Apr 2020

385— Optimizing Nitrogen Concentrations To Maximize Lipid Yields For Biodiesel Production, Wady Jacoby, Daria Zhogina, Pavel Ananev, Lauren Saggese, Max Muller, Barnabas Gikonyo

GREAT Day Posters

Select subspecies of microalgae are considered to be the most promising candidates for third generation renewable resources of biodiesel. Algae not only ingest excess carbon emissions from the atmosphere, they also convert it into energy-dense lipids which can be harvested, and then transformed into biodiesel. However, before the fuel industry can adopt algae farming as a realistic alternative to fossil fuels, the process of harvesting algal lipids must be optimized further. Our research aims to make algal lipid extraction more realistic by determining the ideal growing conditions of the algae species Chlorella Vulgaris. Our research this semester focused on two …

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Analysis Of Petroleum Products For Forensic And Environmental Applications, Sarah Ghali, Sarah Porter Apr 2020

Analysis Of Petroleum Products For Forensic And Environmental Applications, Sarah Ghali, Sarah Porter

Virtual 2020 Spring Student Showcase for Research and Creative Inquiry

In both forensic and environmental applications, it is often important to identify ignitable liquid (IL) residues, to find a suspect or to clean up an oil spill. The ASTM method is commonly used; the extraction methods vary, but the data collection is the same. The instrument used in the ASTM method is gas chromatography mass spectroscopy (GC-MS), which allows a visual identification of the IL contaminating the sample. In this study, the use of Fourier transform infrared spectrometry (FTIR) was used in conjunction with chemometric analysis. Samples were prepared were to simulate an oil spill in natural waters. Two chemometric …

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Surveillance Of Microplastic Pollution In Central Virginia Freshwater Ecosystems, Alexandra Reddy Apr 2020

Surveillance Of Microplastic Pollution In Central Virginia Freshwater Ecosystems, Alexandra Reddy

Senior Honors Theses

Aquatic organisms often mistake microplastic particulates (MP) as food and inadvertently ingest the particulates, which can biomagnify through the food chain. While MP ingestion is well-researched in the marine environment, little is known about microplastics in freshwater  ecosystems. This project explores MP occurrence in an ecologically significant freshwater invertebrate: crayfish. Crayfish from two Central Virginia streams are collected to identify MP in the digestive tracts and gill filaments, and characterize the MP using analytical chemistry techniques. It was determined that MP were present in the digestive tracts and gill filaments of crayfish collected from both streams, and that MP frequency …

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Mercury And Other Trace Metal Analysis In Bat Guano, Amanda Lee Houchens Apr 2020

Mercury And Other Trace Metal Analysis In Bat Guano, Amanda Lee Houchens

Masters Theses & Specialist Projects

Heavy metal pollution in the environment pose risks to ecosystems and the populations that reside in them. Mercury, lead, and cadmium negatively impact humans by way of neurological disorders, various cancers, and damage the reproductive organs, kidneys, and lungs. Bats have been studied as a bioindicator species to identify possibly elevated levels of these metals in the environment. Previous studies have identified correlation between metal concentrations within bat tissues and fur. Many bat species are endangered or at risk due to white-nose syndrome so collection of tissues and fur for analysis can impose stress on bat colonies. This study investigates …

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Using Electrocoagulation To Remove Perfluoroalkyl And Polyfluoroalkyl Substances (Pfas) From Contaminated Water, Amy Yanagida Apr 2020

Using Electrocoagulation To Remove Perfluoroalkyl And Polyfluoroalkyl Substances (Pfas) From Contaminated Water, Amy Yanagida

UCARE: Research Products

Perfluoroalkyl and Polyfluoroalkyl substances (PFAS) are a family of manmade chemicals that are used to improve the quality of several commercial products by making them resistant to heat, oil, stains, grease and water. Unfortunately, the chemical properties that make PFAS useful from an industrial perspective also make them mobile and recalcitrant once released into the environment. We used electrocoagulation to run a direct current through contaminated water to generate a zinc floc to precipiate PFAS out of water.

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Senior Project: An Investigative Study Into The Bacterial Contamination Of Little Black Creek, Margaret I. Brenneman Apr 2020

Senior Project: An Investigative Study Into The Bacterial Contamination Of Little Black Creek, Margaret I. Brenneman

Honors Projects

An investigation of Escherichia coli concentrations in a west Michigan stream was conducted to determine sources of fecal contamination that impact water quality. Little Black Creek (LBC) is located in Muskegon County and discharges into Lake Michigan at the P.J. Hoffmaster Campground Beach. Often referred to as an “indicator bacteria,” water contaminated with E. coli has a high probability to contain other enteric pathogens as well. Beach water testing in 2020 using Colilert-18 methods revealed E. coli levels of 579 cfu/100mL in the creek discharge area that exceeded total body contact criteria of 300 cfu/100mL. A follow-up study of the …

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A Public Health Perspective On Gen X Contamination In Drinking Water, Allison Stevens Apr 2020

A Public Health Perspective On Gen X Contamination In Drinking Water, Allison Stevens

Honors Capstone Enhancement Presentations

No abstract provided.

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Brown Carbon Production By Aqueous-Phase Interactions Of Glyoxal And So2, David O. De Haan, Kevin Jansen, Alec D. Rynaski, W. Ryan P. Sueme, Ashley K. Torkelson, Eric T. Czer, Alexander K. Kim, Michael A. Rafla, Audrey C. De Haan, Margaret A. Tolbert Mar 2020

Brown Carbon Production By Aqueous-Phase Interactions Of Glyoxal And So2, David O. De Haan, Kevin Jansen, Alec D. Rynaski, W. Ryan P. Sueme, Ashley K. Torkelson, Eric T. Czer, Alexander K. Kim, Michael A. Rafla, Audrey C. De Haan, Margaret A. Tolbert

Chemistry and Biochemistry: Faculty Scholarship

Oxalic acid and sulfate salts are major components of aerosol particles. Here, we explore the potential for their respective precursor species, glyoxal and SO2, to form atmospheric brown carbon via aqueous-phase reactions in a series of bulk aqueous and flow chamber aerosol experiments. In bulk aqueous solutions, UV- and visible-light-absorbing products are observed at pH 3–4 and 5–6, respectively, with small but detectable yields of hydroxyquinone and polyketone products formed, especially at pH 6. Hydroxymethanesulfonate (HMS), C2, and C3 sulfonates are major products detected by electrospray ionization mass spectrometry (ESI-MS) at pH 5. Past studies …

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Dissipation Of Benzobicyclon And Benzobicyclon Hydrolysate In A Louisiana Rice Field, Xavier Poole Mar 2020

Dissipation Of Benzobicyclon And Benzobicyclon Hydrolysate In A Louisiana Rice Field, Xavier Poole

LSU Master's Theses

Pesticide resistance in rice fields is an ongoing issue that has resulted in the development and use of pesticides with new modes of action. Benzobicyclon is the first registered hydroxyphenylpyruvate(HPPD)-inhibiting pesticide in the United States and has gained attention as a resistance management strategy to control weed pests in rice fields. Understanding the environmental fate and dissipation mechanisms of benzobicyclon is important due to the unique rotation of rice and crayfish in Louisiana on the same fields. Benzobicyclon persistence into the crayfish growing seasons may lead to unintended consequences for crayfish growth and production, assuming there is toxicity to crawfish. …

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Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman Mar 2020

Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Atmospheric methanethiol (MeSHa), dimethyl sulfide (DMSa) and acetone (acetonea) were measured over biologically productive frontal waters in the remote southwest Pacific Ocean in summertime 2012 during the Surface Ocean Aerosol Production (SOAP) voyage. MeSHa mixing ratios varied from below the detection limit (< 10 ppt) up to 65 ppt and were 3 %–36 % of parallel DMSa mixing ratios. MeSHa and DMSa were correlated over the voyage (R2=0.3, slope = 0.07) with a stronger correlation over a coccolithophore-dominated phytoplankton bloom (R2=0.5, slope 0.13). The diurnal cycle for MeSHa shows similar behaviour to DMSa with mixing ratios …

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Assessing The Ecological Risk Of Heavy Metal Sediment Contamination From Port Everglades Florida, Dimitri G. Giarikos, Laura White, Amy C. Hirons Mar 2020

Assessing The Ecological Risk Of Heavy Metal Sediment Contamination From Port Everglades Florida, Dimitri G. Giarikos, Laura White, Amy C. Hirons

SECLER Data

Port sediments are often contaminated with metals and organic compounds from anthropogenic sources. Port dredging can remobilize contaminated sediments, resulting in harmful impacts to the benthic community. Twelve sediment cores were collected from four Port Everglades, Florida sites and a control site; surface sediment was collected at two nearby coral reef sites. Sediment cores, sampled every 5 cm, were quantified for 14 heavy metals using induced coupled plasma mass spectrometry (ICPMS). Geo-accumulation index shows moderate-to-strong contamination of As and Mo in port sediments, and potential ecological risk indicates moderate-to-significantly high overall metal contamination. Arsenic port sediment concentrations exceed threshold effect …

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Synthesis And Fabrication Of Trimetallic (Ru-Mn Co) Catalyst Supported On Tio2 And Ni(Oh)2 Thin Films For Photoelectrochemical Applications, Che Mat Ahmad Nazeer Mar 2020

Synthesis And Fabrication Of Trimetallic (Ru-Mn Co) Catalyst Supported On Tio2 And Ni(Oh)2 Thin Films For Photoelectrochemical Applications, Che Mat Ahmad Nazeer

Student Works (2020-2029)

Anatase supported heterogeneous photocatalyst consisting of RuO2, MnO2 and Co3O4 (1:13:13 ratio) was synthesized by precipitation method. The film of the prepared catalyst was fabricated by electrophoretic deposition technique in an aqueous solution of 0.1 mM ammonia and tested for photoelectrocatalytic (PEC) oxidation of methanol in 0.1M KOH under visible light irradiation. The as-prepared photocatalyst was characterized by FTIR, UV–Vis, XRD, Raman spectroscopy, FESEM/EDX, TEM, BET, XPS and TPR. The PEC study by cyclic voltammetry indicates that the oxidation of methanol to CO2 and H2O upon exposure to visible light occurs between 400 and 800 nm. The smaller value of …

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Surface Reservoirs Dominate Dynamic Gas-Surface Partitioning Of Many Indoor Air Constituents, Chen Wang, Douglas B. Collins, Caleb Arata, Allen H. Goldstein, James M. Mattila, Delphine K. Farmer, Laura Ampollini, Peter F. Decarlo, Atila Novoselac, Marina E. Vance, William W. Nazaroff, Jonathan P.D. Abbatt Feb 2020

Surface Reservoirs Dominate Dynamic Gas-Surface Partitioning Of Many Indoor Air Constituents, Chen Wang, Douglas B. Collins, Caleb Arata, Allen H. Goldstein, James M. Mattila, Delphine K. Farmer, Laura Ampollini, Peter F. Decarlo, Atila Novoselac, Marina E. Vance, William W. Nazaroff, Jonathan P.D. Abbatt

Faculty Journal Articles

Human health is affected by indoor air quality. One distinctive aspect of the indoor environment is its very large surface area that acts as a poorly characterized sink and source of gas-phase chemicals. In this work, air-surface interactions of 19 common indoor air contaminants with diverse properties and sources were monitored in a house using fast-response, on-line mass spectrometric and spectroscopic methods. Enhanced-ventilation experiments demonstrate that most of the contaminants reside in the surface reservoirs and not, as expected, in the gas phase. They participate in rapid air-surface partitioning that is much faster than air exchange. Phase distribution calculations are …

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