Environmental Chemistry Commons^™

Investigation Of Factors Influencing Recombination Versus Disproportionation Of Complex Radicals Formed By C-N Homolysis Of Breslow Type Intermediates And Related Compounds, Taylor Burnett

Graduate Theses and Dissertations

Electron rich enamines are capable of C-N bond homolysis and subsequent recombination and/or disproportionation. It is unclear what causes these radicals to undergo recombination or disproportionation. Density Functional Theory (DFT) calculations do not provide a transition state for the recombination and disproportionation processes and therefore they cannot be used to predict the favorable reaction. Breslow intermediates formed by deprotonation of thiazolium salts and reaction with aromatic aldehydes are examples of electron rich enamines. These breslow intermediates can undergo C-N bond homolysis to form a radical pair the either recombine or disproportionate. Upon investigation of the factors influencing recombination and disproportionation, …

Engineered Nanostructured Nitrogen-Doped Carbon Network (Ndc) Electrodes With Unprecedented Cycling Stability For Water Capacitive Deionization In Harsh Conditions, Soha Essam Anwar

Theses and Dissertations

Capacitive deionization (CDI) is a feasible low-cost desalination technique for low-to-medium (brackish) salinity water. However, cycling stability and regeneration of the CDI electrodes are the bottlenecks hindering the practical application of the technology on large scale. Oxidation of the electrodes during the sequential adsorption-desorption processes is one of the most challenging problems hindering their long-term cycling performance. Herein, we demonstrated the ability to design and fabricate exceptionally stable CDI electrodes via a one-pot pyrolysis protocol. The optimized pyrolysis of nitrogen-carbon precursors at different temperatures enabled the fabrication of carbon materials with a controlled amount nitrogen dopant (NDCs) with exceptional cycling …

Isolation And Determination Of The Composition And Structural Components That Comprise Dissolved Organic Matter Using Normal Phase Liquid Chromatography, Jonathan A. Long Jr

LSU New Orleans Theses and Dissertations

A comprehensive understanding of the reactivity associated with organic carbon is critical for recognizing the behavior of newly formed compounds in aquatic environments. In an effort to study the reactivity of complex mixtures, understanding the different processes affiliated with them are key. Understanding the reactivity associated with organic carbon can help to improve chromatographic separation. Using a combination of light and heavy crude oil, a separation procedure was developed to obtain a complete representation of the aromatic subfraction of the crude oil sample. The crude oils were separated into four distinct fractions based on the number of condensed aromatic rings …

Modeling Biliary Polycyclic Aromatic Hydrocarbon Metabolites In Fish Using High Performance Liquid Chromatography With Fluorescence Detection, Principal Component Analysis, And Partial Least-Squares Analysis, Joshua C. Padilla

Honors Projects

Polycyclic aromatic hydrocarbons (PAHs) constitute a diverse class of highly toxic, ubiquitous environmental pollutants, and are thus of high interest in environmental monitoring and regulation. In this study, biliary samples of English soles Parophrys vetulus and smallmouth bass Micropterus dolomieu from Seattle waterways, and chum salmon Onchorynchus keta from the north Pacific Ocean were analyzed by high performance liquid chromatography with fluorescence detection (HPLC-FLD) to gauge PAH exposure. Samples were profiled in three broad molecular weight categories, to capture naphthalene-like (NAPH), phenanthrene-like (PHEN), and benzo[a]pyrene-like (BAP) metabolites. While quantification was not achieved for the chum salmon, the semi-quantitative measurements of …

Water Purification And The Industries It Supports, Zeljka Zec, Kj Bell

Symposium of Student Scholars

Water Purification and the Industries It Supports

Zeljka Zec and KJ Bell

Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, Ga 30144

Clean and readily available water plays a crucial role in daily societal functions. The dynamic research of water purification involves the process of removing undesired chemical or biological contaminants that affect our use of fresh, consumable water. Depending on desired applications, purification quality is adjusted for use in medical settings, manufacturing, agriculture or personal use in households. Several methods and techniques have been used in the water purification process. Those processes are coagulation, flocculation, sedimentation, and filtration. …

Addressing Uncertainties Of Polychlorinated Biphenyls In Schools, Alice Fan

Master's Projects and Capstones

Despite the potential neurological health deficits resulting from polychlorinated biphenyls, there is a lack of inhalation studies and regulations to protect students and teachers who are widely exposed to PCBs in older (1950 to 1979) schools. To estimate the extent of PCB detections in Los Angeles County schools, I applied a mathematical model to estimate the range of PCB detections in schools built between 1950 and 1984. I estimate the range of 17-34% PCB detections of open schools within Los Angeles County. Next, I reviewed exposure tools provided by the US EPA to bridge the uncertainty gaps between ingestion and …

Scan Of The Advantage Of Using Biofuels, Ethanol, Ana Carla Bueno

Symposium of Student Scholars

The environment is the big sink where all the human waste produced is deposited, mainly the pollutant gases from cars. It is inevitable not to contaminate drinking water, air, and all other ecosystems on the planet, and it was from these concerns that scientists began to develop alternative ways to mitigate the side effects of pollution. Currently, there are many strategies to soften the emission of pollutant gases into the atmosphere, and the biggest competitor of traditional fossil fuel is biofuels. The big challenge in the production of this type of fuel is the competition with the conventional fossil fuel, …

Balancing Community Health And Industry Objectives, Lindsay Tudor

Symposium of Student Scholars

Balancing Community Health and Industry Objectives

Lindsay Tudor

Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, GA 30144

The ever-changing regulatory and federal standards set by the EPA and other organizations are creating a large impact on chemical manufacturing. The Environmental Protection Agency (EPA) maintains jurisdiction under the Toxic Substances Control Act (TSCA) to enforce regulations structured to impart information regarding the health and safety of individuals, environmental impacts, and exposure thresholds of chemical substances. Flame retardants are among the chemicals assessed and restricted, most recently isopropyl phenyl phosphate. Isopropyl phenyl phosphate is a flame retardant/lubricant utilized in various …

Records Of Enriched Uranium Atmospheric Deposition In Pond Sediments In Piketon, Oh, Brianna Herner, Brian Majestic, Michael Ketterer

DU Undergraduate Research Journal Archive

The enrichment of uranium, often for nuclear weapons programs and commercial nuclear reactors, produces higher concentrations of radioactive uranium 235 (²³⁵U) than what naturally occurs, which can pose a human health hazard. The most abundant naturally occurring uranium isotope is ²³⁸U, which is still radioactive, however a higher concentration of ²³⁵U skews the observed isotopic uranium distribution. The Department of Energy Portsmouth Gaseous Diffusion Plant, located near Piketon, OH, enriched uranium from 1954 to 2001 and ²³⁵U pollution has recently been detected in air and sediment samples in the surrounding community. The extent of the …

Effects Of Environmental Change On Ancestral Pueblo Fishing In The Middle Rio Grande, Jonathan William Dombrosky

Anthropology ETDs

It has long been assumed that fishes were unimportant in the diet of past Pueblo people in the U.S. Southwest. Yet, small numbers of fish remains are consistently recovered from Late pre-Hispanic/Early Historic archaeological sites in the Middle Rio Grande of New Mexico. The end of drought conditions may have impacted food choice and fishing decisions during this time. I use behavioral ecology to understand how fishing could have been an optimal food-getting strategy for Ancestral Pueblo farmers. Stable isotope analysis offers a way to account for environmental change. I provide a refined ¹³C Suess correction model to support …

Taipei Taiwan - 1993

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Seoul Korea - 1993

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Leicester United Kingdom

World Data - Europe

Relevant Publications

Environmental Science & Technology Publication (1995)

Lisbon Portugal - 1994

World Data - Europe

Relevant Publications

Environmental Science & Technology Publication (1995)

Monterrey Mexico - 1995

World Data - North America

Relevant Publications

Environmental Science & Technology Publication (1997)

Final Report

Tokyo Japan - 1995

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Malaysia - 1995

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Hong Kong - 1993

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Melbourne - 1992

World Data - Australia

Relevant Publications

Environmental Science & Technology Publication (1995)

Final Report

Milan Italy - 1994

World Data - Europe

Relevant Publications

Environmental Science & Technology Publication (1995)