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Full-Text Articles in Chemistry

Determining The Lon-Exchange Mechanism Of Strontium Into A Niobium Doped Titanosilicate, Samantha Jane Kramer May 2011

Determining The Lon-Exchange Mechanism Of Strontium Into A Niobium Doped Titanosilicate, Samantha Jane Kramer

Masters Theses & Specialist Projects

A 25% niobium substituted sitinakite was exchanged with strontium as time resolved X-ray diffraction data was collected. The structural modeling of this data by Rietveld method1 has lead to the determination of the atomic positions of the ions and unit cell parameters as strontium occupancy increases.

The starting material of the exchange experiment is the protonated phase, H2Nb0.67Ti1.33SiO7·1.9 H2O, with space group P42/mcm2,3. Once strontium (Sr2+) enters the unit cell, extra-framework H2O molecules shift to provide the necessary hydration coordination. These new positions of H2O result in a lowering of symmetry to the P-42m space group, and it is thought …


Approach To Arsenic And Selenium Removal From Fly Ash By Oxalate And Estimation Of Calcium Effects On Both Elements, Ying Wen May 2011

Approach To Arsenic And Selenium Removal From Fly Ash By Oxalate And Estimation Of Calcium Effects On Both Elements, Ying Wen

Masters Theses & Specialist Projects

An approach to arsenic and selenium removal from fly ash is studied. This research includes a comparison of the leaching ability of ammonium oxalate, ammonium citrate, ammonium nitrate and EDTA to extract arsenic and selenium; use of common agricultural waste as a source of oxalate anion to remove arsenic and selenium from fly ash and estimation of additional calcium effects on arsenic and selenium leaching behaviors.
This research shows that extraction strength order is EDTA > ammonium oxalate > ammonium citrate > ammonium nitrate > water, achieving arsenic extraction efficiencies of 94.18%, 84.17%, 4.50%, 2.89% and 0.18%, respectively; achieving selenium extraction efficiencies of 96.14%, …


An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede May 2011

An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede

Department of Environmental Studies: Undergraduate Student Theses

Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results.  In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks.  Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the …


Energy Densification Via Hydrothermal Carbonization, Keri Noack Apr 2011

Energy Densification Via Hydrothermal Carbonization, Keri Noack

Festival of Communities: UG Symposium (Posters)

A process called hydrothermal carbonization (HTC), also known as wet torrefaction involves treatment of raw biomass in hot, pressurized water. HTC of woody biomass has been shown to significantly increase the energy density of the feedstock, producing a biochar, similar to coal, having up to 40% higher calorific energy content. Feedstocks investigated include Tahoe chips, Pinion/Juniper chips, Rice hulls, and Corn Stover pellets pre-treated at 215 °C, 255 °C, and 295 °C. Chemical analyses were conducted on the gaseous, aqueous, and solid HTC products. Energy contents of the solid biochar products were measured by calorimetry, and mass balances were determined.


Spectroscopic (Ir, Nmr, Uv-Vis), Theoretical Study And Optical Properties Of 9,10-Dihydrobenzo(A)Pyrene-7(8h)-One And 7, 8, 9, 10-Tetrahydrobenzo(A)Pyrene, Mireya Martinez Apr 2011

Spectroscopic (Ir, Nmr, Uv-Vis), Theoretical Study And Optical Properties Of 9,10-Dihydrobenzo(A)Pyrene-7(8h)-One And 7, 8, 9, 10-Tetrahydrobenzo(A)Pyrene, Mireya Martinez

Undergraduate Research Conference

Polycyclic aromatic hydrocarbons (PAHs) are organic molecules found in the environment. The PAHs are formed from incomplete combustion, are found in diesel exhaust particles, grilled foods, gas burners, emission from wood, and cigarette smoke. These compounds are known to be carcinogenic and mutagenic1,2. Spectroscopic studies were performed on two PAHs, 9,10- dihydrobenzo(a) pyrene-7(8H)-one and 7,8,9,10- tetrahydrobenzo(a)pyrene, which helped to characterize them. Also, a theoretical infrared study was done on 9,10-H2BaP, a scaling factor was found for a simulated infrared spectrum.


Toxicity Of Tio2 Nanoparticles In Cucumis Sativus, Fabiola Moreno-Olivas^, Isaac Montes, Alia D. Servin, Hiram Castillo-Michel, José R. Peralta-Videa, Jorge L. Gardea-Torresdey* Apr 2011

Toxicity Of Tio2 Nanoparticles In Cucumis Sativus, Fabiola Moreno-Olivas^, Isaac Montes, Alia D. Servin, Hiram Castillo-Michel, José R. Peralta-Videa, Jorge L. Gardea-Torresdey*

COURI Symposium Abstracts, Spring 2011

Nanoparticles (NPs) have a wide range of applications in medicine, electronics, catalysis, cosmetics, and pharmaceuticals. TiO2 NPs are very stable and can be transported and dispersed into aquatic environments. Several animal species have shown negative reaction to TiO2 NPs. However, little is known about their toxicity on plants, specially their possibility to enter the food chain via the crops utilized or subsequent production steps. We have studied the possible genotoxic effects of TiO2 NPs on cucumber (Cucumis sativus), a worldwide cultivated species that serves as food for insects and other animals in the food web. Seven-day old hydroponically …


A Sodium Salt Of The Dimer Of Boronoterephthalic Acid Anhydride, Scott Simmons, Albert Fratini, Vladimir Benin Apr 2011

A Sodium Salt Of The Dimer Of Boronoterephthalic Acid Anhydride, Scott Simmons, Albert Fratini, Vladimir Benin

Chemistry Faculty Publications

The title compound, sodium bis­(6-carb­oxy-1-hy­droxy-3-oxo-1,3-dihydro-2,1-benzoxaborol-1-yl)oxidanium, Na+·C16H15B2O13-, was prepared in two steps from 2-bromo-p-xylene. Its crystal structure was determined at 140 K and has triclinic (P) symmetry. The compound presents a unique structural motif, including two units of the cyclic anhydride of boronoterephthalic acid, joined by a protonated, and thereby trivalent, oxonium center. Association in the crystal is realized by complementary hydrogen bonding of the carboxyl groups, as well as by coordination of the sodium cations to the oxygen centers on the five-membered rings.


Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera, Michael Horwath, Vladimir Benin Apr 2011

Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera, Michael Horwath, Vladimir Benin

Chemistry Faculty Publications

Moringa oleifera, sometimes called the “Miracle Tree,” has received international attention for its potential to improve health in impoverished tropical areas. In addition to high vitamin content in the leaves and pods, the tree contains compounds with antioxidant and antibacterial properties. This study focused on the theoretical investigation of the suggested structure of one antibacterial compound, “pterygospermin,” whose existence was proposed after some studies of the roots of M. oleifera. The structure of pterygospermin was first proposed by a research group working in the 1950s, but later studies have not found evidence of this compound and have instead …


Method Development For The Analysis Of Ddt, Ddd, And Dde In Cow Milk, Amanda Parra^, Betty Rocha, Wen-Yee Lee* Mar 2011

Method Development For The Analysis Of Ddt, Ddd, And Dde In Cow Milk, Amanda Parra^, Betty Rocha, Wen-Yee Lee*

COURI Symposium Abstracts, Spring 2011

Organochlorine Pesticides (OCs) are classified as persistent organic pollutants (POPs). They have been found to bioaccumulate in organisms over time. These chemicals tend to attach to fatty tissues in animals and humans, remaining for long periods of time. OCs may be responsible for a vast number of health conditions including neurological disorders, endocrine disruption, reproductive dysfunctions, and possible linkage to cancer.  OCs such as DDT, DDE and DDD are banned, however, they have still been detected in environmental samples worldwide. The main objective of this study is to investigate the presence of DDT, DDE and DDD in cow milk using …


Reduced Activity Of Multiple Endocrine Disrupting Compounds: 17Β-Estradiol And Bisphenol A With A Chemi-Luminescent Assay, Anna C. Ortiz^, Roberto J. De La Torre-Roche, Marc B. Cox, Wen-Yee Lee* Mar 2011

Reduced Activity Of Multiple Endocrine Disrupting Compounds: 17Β-Estradiol And Bisphenol A With A Chemi-Luminescent Assay, Anna C. Ortiz^, Roberto J. De La Torre-Roche, Marc B. Cox, Wen-Yee Lee*

COURI Symposium Abstracts, Spring 2011

The concern about the impacts of endocrine disrupting compounds (EDCs) in the environment has increased recently with their high occurrence in surface waters and sex changes in various aquatic organisms. EDCs include ubiquitously used pharmaceuticals and personal care products, such as soap, detergents, contraceptives, and other medicines, which are released constantly into the environment, in waste water treatment plant effluent. Though toxicological effects of these individual, EDCs have been studied, knowledge on how these chemicals interact together in the environment is very limited. The objective of this project is to study the multi-residue effect of EDCs using a chemi-luminescent yeast …


Evaluation Of The Sensitivity Of Inventory And Monitoring National Parks To Nutrient Enrichment Effects From Atmospheric Nitrogen Deposition Northern Great Plains Network (Ngpn), T. J. Sullivan, T. C. Mcdonnell, G. T. Mcpherson, S. D. Mackey, D. Moore Feb 2011

Evaluation Of The Sensitivity Of Inventory And Monitoring National Parks To Nutrient Enrichment Effects From Atmospheric Nitrogen Deposition Northern Great Plains Network (Ngpn), T. J. Sullivan, T. C. Mcdonnell, G. T. Mcpherson, S. D. Mackey, D. Moore

United States National Park Service: Publications

Northern Great Plains Network (NGPN)

National maps of atmospheric N emissions and deposition are provided in Maps A and B as context for subsequent network data presentations. Map A shows county level emissions of total N for the year 2002. Map B shows total N deposition, again for the year 2002.

There are three parks in the Northern Great Plains Network that are larger than 100 square miles: Badlands (BADL), Missouri (MNRR), and Theodore Roosevelt (THRO). In addition, there are 10 other smaller parks.

Total annual N emissions, by county, are shown in Map C for lands in and surrounding …


Trends In Heavy-Duty Diesel Emissions And Analyses Of Colorado's Light-Duty Vehicle Inspection And Maintenance Program, Brent G. Schuchmann Jan 2011

Trends In Heavy-Duty Diesel Emissions And Analyses Of Colorado's Light-Duty Vehicle Inspection And Maintenance Program, Brent G. Schuchmann

Electronic Theses and Dissertations

Emission trends are reported and discussed resulting from the multi-year study of Heavy-Duty Diesel Vehicles (HDDV) at the Port of Los Angeles and at a weigh station in Peralta also in the L.A. basin. Remote sensing data were also collected from the Port of Houston and compared to the data from California. As part of San Pedro Bay Ports Clean Air Action Plan (CAAP) to fast track the turnover rate of cleaner trucks, many truck operators have been subject to modifying their trucks, or have purchased new trucks, with more advanced control technologies to reduce exhaust particulate matter (PM) and …


Chemical Characterization Of Lake Gregory, Eric Steven Torres Jan 2011

Chemical Characterization Of Lake Gregory, Eric Steven Torres

Theses Digitization Project

The purpose of this study is to characterize the water chemistry of Lake Gregory in Crestline, California. The collection of water samples occurred a short time after the end of the summer recreational season in the late fall. Several chemical parameters were measured in an effort to determine the overall water quality during this time.


Development Of Biomarkers For Endocrine Disrupting Compounds In The Fathead Minnow, Pimephales Promelas, Tara Frare Jan 2011

Development Of Biomarkers For Endocrine Disrupting Compounds In The Fathead Minnow, Pimephales Promelas, Tara Frare

Undergraduate Review

Organic waste compounds (OWC’s) are an environmental concern that can have adverse effects on humans, animals, and the environment. Ethinyl estradiol (EE2) is one common OWC and is an active ingredient in oral birth control pills. The presence of EE2 in aquatic environments and drinking water can be linked to decreased fertility and altered physiology in fish. I am developing Q-PCR biomarkers to detect changes in fish at low concentrations before adverse effects occur at higher concentrations. RNA was extracted from twenty fathead minnows that had not been exposed to OWC’s and will be used to synthesize cDNA. Thus far …


Variations In Concentrations And Compositions Of Polycyclic Aromatic Hydrocarbons (Pahs) In Coals Related To The Coal Rank And Origin, Susanne Laumann, Vesna Micic Batka, Michael A. Kruge, Christine Achten, Reinhard Sachsenhofer, Jan Schwarzbauer, Thilo Hofmann Jan 2011

Variations In Concentrations And Compositions Of Polycyclic Aromatic Hydrocarbons (Pahs) In Coals Related To The Coal Rank And Origin, Susanne Laumann, Vesna Micic Batka, Michael A. Kruge, Christine Achten, Reinhard Sachsenhofer, Jan Schwarzbauer, Thilo Hofmann

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The release of unburnt coal particles and associated polycyclic aromatic hydrocarbons (PAHs) may cause adverse impacts on the environment. This study assessed variations in the concentration and composition of PAHs in a set of fifty coal samples from eleven coal basins worldwide. The maximum PAH concentrations at high volatile bituminous rank were recorded in samples from a single basin. Considering the entire sample, the highest PAH concentrations were in fact found outside of this rank range, suggesting that the maceral composition and thus the coal's origin also influenced PAH concentrations. The examination of the PAH compositions revealed that alkylated 2-3 …


Climate Change: The Fork At The End Of Now, Micha Tomkiewicz Jan 2011

Climate Change: The Fork At The End Of Now, Micha Tomkiewicz

Publications and Research

There are many books on global warming written entirely from a layman's perspective, and there is a great deal of scientific literature on this subject. But few if any books attempt to bridge the science to those who lack a rigorous background in mathematics, physics and chemistry-but who may be working on careers in environmental science and policy. The new text is designed to introduce the field of global climate change from a scientific perspective-but written in a way that is accessible to students with some or little science background. It reviews the basic principles of climatic thermodynamics and atmospheric …


The Impact Of Driving Conditions On Phev Battery Performance, Nathan Christensen, John Patten, Steven Srivastava, Gary P. Nola Jan 2011

The Impact Of Driving Conditions On Phev Battery Performance, Nathan Christensen, John Patten, Steven Srivastava, Gary P. Nola

Green Manufacturing Research Journal

The battery performance of a modified Prius with a 5 kWh plug-in battery was documented for a year to determine the impact of environmental conditions and user attributes on vehicle performance.  Both fuel economy and pure electrical efficiency were compared to ambient temperature.  The fuel economy has a positive relationship with ambient temperature until approximately 70˚F where the efficiency begins to drop.  Electrical performance has a positive linear relationship with ambient temperature.  With the emergence of electric vehicles (EVs) and PHEVs from a variety of automotive manufacturers, information on EV and PHEV performance for consumers will become more important.


Fourier Transform Mass Spectrometry For The Molecular Level Characterization Of Natural Organic Matter: Instrument Capabilities, Applications, And Limitations, Rachel L. Sleighter, Patrick G. Hatcher, Goran Nikolić (Ed.) Jan 2011

Fourier Transform Mass Spectrometry For The Molecular Level Characterization Of Natural Organic Matter: Instrument Capabilities, Applications, And Limitations, Rachel L. Sleighter, Patrick G. Hatcher, Goran Nikolić (Ed.)

Chemistry & Biochemistry Faculty Publications

No abstract provided.


Trace Metal Dispersion In Soil From Auto-Mechanic Village To Urban Residential Areas In Owerri, Nigeria, Michael A. Nwachukwu, Huan Feng, Jude Alinnor Jan 2011

Trace Metal Dispersion In Soil From Auto-Mechanic Village To Urban Residential Areas In Owerri, Nigeria, Michael A. Nwachukwu, Huan Feng, Jude Alinnor

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Due to poor waste management in mechanic villages (MVs), average metal concentration (mgkg-1) is Pb 1162±572; Mn 864±531; Cu 385±202; Fe 49259±4770; Cd 20±13; Zn 824±190; and Ni 40±35, causing ecological and public health risks in parts of Nigeria. Average metal dispersion (mgkg-1/m) from MVs to residential areas was estimated at 9.2 for Pb; 6.7 for Mn; 6.1 for Zn; 1.5 for Cu; 197 for Fe; 0.3 for Ni; and 0.04 for Cd. This represents a mobility order of Fe>Pb>Mn>Zn>Cu>Ni>Cd, and a pollution order of Pb>Ni>Mn>Zn>Fe>Cu>Cd. MV advantages …


Fossil And Contemporary Aerosol Particulate Organic Carbon In The Eastern United States: Implications For Deposition And Inputs To Watersheds, Andrew S. Wozniak, James E. Bauer, Rebecca M. Dickhut Jan 2011

Fossil And Contemporary Aerosol Particulate Organic Carbon In The Eastern United States: Implications For Deposition And Inputs To Watersheds, Andrew S. Wozniak, James E. Bauer, Rebecca M. Dickhut

Chemistry & Biochemistry Faculty Publications

Atmospheric particulate matter samples were collected from mid-Atlantic and northeastern U. S. (Virginia and New York, respectively) sites to assess the fossil versus contemporary sources contributing to aerosol organic carbon (OC) and the implications for its deposition to watersheds. Mean particulate matter total OC (TOC) deposition rates (wet + dry deposition) were calculated to be 1.6 and 2.4 mg C m-2 d-1 for the Virginia and New York sites, respectively. Wet deposition of particulate TOC was determined to be the dominant depositional mode, accounting for >65% (Virginia) and >80% (New York) of total aerosol TOC deposition. Isotopic mass …


The Release Of Calcium In Bacillus Anthracis Pathogenicity, Natiera Magnuson, Manomita Patra, Maria Elena Reynaga, Ernesto Abel-Santos Jan 2011

The Release Of Calcium In Bacillus Anthracis Pathogenicity, Natiera Magnuson, Manomita Patra, Maria Elena Reynaga, Ernesto Abel-Santos

McNair Poster Presentations

Bacillus anthracis spores form in response to starvation and can withstand extremes of heat, radiation, and chemical toxins, making B. anthracis spores ideal vehicles for infections.1 The resistance and dormancy of bacterial spores are dependent on a largely dehydrated core.2 The spore core is not only devoid of water, but contains between 0.8 to 1M calcium complexed with 2,6-pyridinedicarboxylic acid (dipicolinic acid, DPA). The DPA-calcium complex (CaDPA) helps protect DNA, RNA, and the metabolic enzymes needed for the establishment of a vegetative cell cytoplasm.3 An anthrax infection starts with the germination of B. anthracis spores in a macrophage.4 The germinated …


A Practical Photoelectrochemical Cell Using Nonprecious Metal Electrodes, Patrick Enright, Tony Betts, John Cassidy Jan 2011

A Practical Photoelectrochemical Cell Using Nonprecious Metal Electrodes, Patrick Enright, Tony Betts, John Cassidy

Articles

Abstract: Photoelectrochemical cells (PECs) can be used to harvest light from the oxidation of dissolved organic matter. Similar to fuel cells but requiring light to operate, PECs contain a light assisted electrode that oxidises electron rich materials (anode); these electrons then flow to a typically Pt cathode where O2 is normally the electron acceptor. In this work a PEC cell containing inexpensive materials was shown to (a) mineralise typical organic compounds present in waste water and (b) produce electricity from their decomposition. The PEC cell consisted of a TiO2 coated conducting ink anode exposed to a light source, …


Fabrication And Preliminary Characterization Of Hydrophobic Silica Aerogel Films For Oil Remediation Studies, Ellen Yang Jan 2011

Fabrication And Preliminary Characterization Of Hydrophobic Silica Aerogel Films For Oil Remediation Studies, Ellen Yang

Pomona Senior Theses

Due to the potential of oil sorbents for oil spill clean-up, hydrophobic silica-based aerogel thin films have been synthesized and characterized by various methods. Aerogels were prepared using a two-step acid/base sol-gel process and functionalized with trimethylchlorosilane in hexane, followed by drying in ambient conditions. After film deposition by spin-coating, samples were characterized by scanning electron microscopy, nitrogen adsorption analysis (BET surface area = 377.66 m2 /g), and variable-angle spectroscopic ellipsometry (thickness of 287.00 ± 0.85 nm, refractive index of 1.08, porosity of 80.9%). Unlike previous studies with aerogel films, quartz crystal microbalance with dissipation monitoring (QCM-D) was applied to …


The Correlation Of The Concentration Of Selected Metals Determined In Water And Fish Samples From A Public Pond., Paula Kay Edwards Dec 2010

The Correlation Of The Concentration Of Selected Metals Determined In Water And Fish Samples From A Public Pond., Paula Kay Edwards

Electronic Theses and Dissertations

The concentrations of heavy metals (Cd, Cu, Fe, Ni, Pb, Zn) were measured in water, and fish samples caught from the pond at Fishery Park in Unicoi County, TN. The water samples were collected once a week for 8 weeks. The amounts of metals in the muscle tissues, gill, and liver of the two fish species were measured. This was to determine if any correlation exists between the metal contents in water and those in the fish samples. The concentration ranges for the heavy metals found in the water samples are as follows: Zn 0.04-0.13; Cu, 0.00-0.00; Pb, 0.00-0.59; Cd, …


The Vinylguaiacol/Indole Or Vgi ("Veggie") Ratio: A Novel Molecular Parameter To Evaluate The Relative Contributions Of Terrestrial And Aquatic Organic Matter To Sediments., Michael A. Kruge, Kevin K. Olsen, Jaroslaw W. Slusarczyk, Elaine Gomez Dec 2010

The Vinylguaiacol/Indole Or Vgi ("Veggie") Ratio: A Novel Molecular Parameter To Evaluate The Relative Contributions Of Terrestrial And Aquatic Organic Matter To Sediments., Michael A. Kruge, Kevin K. Olsen, Jaroslaw W. Slusarczyk, Elaine Gomez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The organic matter (OM) fraction of estuarine sediments is often distinctive and thus diagnostically useful in determinations of sedimentary provenance. Among the most fundamental distinctions to be made is that between terrestrial and aquatic OM. To supplement the parameters commonly used for this purpose (e.g., C/N and stable isotope ratios), we proposed the Vinylguaiacol/Indole or VGI ("Veggie") ratio, defined as [vinylguaiacol / (indole + vinylguaiacol)] using data produced by analytical pyrolysis-gas chromatography/mass spectrometry of dried, homogenized sediment samples. The ratio employs the peak areas of these two compounds on the mass chromatograms of their molecular ions (m/z 150 and 117). …


On The Perfection Of Broccoli: Talking To Ed Brush, Lee Torda Dec 2010

On The Perfection Of Broccoli: Talking To Ed Brush, Lee Torda

Bridgewater Review

No abstract provided.


Synthesis And Catalytic Activity Of Nanostructured Cerium Oxide, Neil J. Lawrence Dec 2010

Synthesis And Catalytic Activity Of Nanostructured Cerium Oxide, Neil J. Lawrence

Department of Chemistry: Dissertations, Theses, and Student Research

Cerium oxide (ceria, CeO2-x where x is 0 to 0.5) has been one of the most widely used heterogeneous catalysts particularly in three way catalytic converters. Most of the catalytic traits can be attributed to two properties of ceria: first, the high mobility and storage capacity of oxygen within the lattice; second, the ease with which cerium changes between Ce3+ and Ce4+ states. These properties, combined with the abundance of cerium on earth, make ceria a low-cost highly effective alternative to noble metal catalysts. Recent research has been focused on the nanoscale properties of ceria.

The effect …


Synthesis, Kinetic And Photocatalytic Studies Of Porphyrin-Ruthenium-Oxo Complexes, Yan Huang Aug 2010

Synthesis, Kinetic And Photocatalytic Studies Of Porphyrin-Ruthenium-Oxo Complexes, Yan Huang

Masters Theses & Specialist Projects

Macrocyclic ligand-complexed transition metal-oxo intermediates are the active oxidizing species in a variety of important biological and catalytic oxidation reactions. Many transition metal catalysts have been designed to mimic the predominant oxidation catalysts in Nature, namely the cytochrome P450 enzymes. Ruthenium porphyrin complexes have been the center of the research and have successfully been utilized, as catalysts, in major oxidation reactions such as the hydroxylation of alkanes. This study focuses on kinetic and photocatalytic studies of oxidation reactions with wellcharacterized high-valent ruthenium-oxo porphyrin complexes.
The trans-dioxoruthenium(VI) porphyrins have been among the best characterized metal-oxo intermediates and their involvement as …


Fluorescent Chemosensors For Toxic Organophosphorus Pesticides: A Review, Sherine O. Obare, Chandrima De, Wen Guo, Tajay L. Haywood, Tova A. Samuels, Clara P. Adams, Noah O. Masika, Desmond H. Murray, Ginger A. Anderson, Keith Campbell, Kenneth Fletcher Jul 2010

Fluorescent Chemosensors For Toxic Organophosphorus Pesticides: A Review, Sherine O. Obare, Chandrima De, Wen Guo, Tajay L. Haywood, Tova A. Samuels, Clara P. Adams, Noah O. Masika, Desmond H. Murray, Ginger A. Anderson, Keith Campbell, Kenneth Fletcher

Faculty Publications

Many organophosphorus (OP) based compounds are highly toxic and powerful inhibitors of cholinesterases that generate serious environmental and human health concerns. Organothiophosphates with a thiophosphoryl (P=S) functional group constitute a broad class of these widely used pesticides. They are related to the more reactive phosphoryl (P=O) organophosphates, which include very lethal nerve agents and chemical warfare agents, such as, VX, Soman and Sarin. Unfortunately, widespread and frequent commercial use of OP-based compounds in agricultural lands has resulted in their presence as residues in crops, livestock, and poultry products and also led to their migration into aquifers. Thus, the design of …


Assessing Commercial Organic And Conventionally Grown Vegetables By Monitoring Selected Heavy Metals Found In Them., Charles Kafui Dotse May 2010

Assessing Commercial Organic And Conventionally Grown Vegetables By Monitoring Selected Heavy Metals Found In Them., Charles Kafui Dotse

Electronic Theses and Dissertations

Commercially available organic and conventionally grown vegetables were studied by quantitative determination of selected metals in them and to determine if any differences found are statistically significant. These findings can help the consumers to determine if the vegetable products are within the recommended maximum limits as proposed by the joint FAO/WHO Expert committee on organic foods designation. Eight edible vegetables were purchased from local stores in both the organic and conventionally grown categories. Samples were digested with concentrated nitric acid and the metals monitored were zinc, copper, lead, iron, cadmium, and nickel using flame atomic absorption. The concentration range for …