Chemistry Commons^™

Synthesis And Computational Studies Of A New Class Of Lanthanide Niobate Cluster : [Ln4(H2O)8(So4)5(Nbo3)2]+3h2O; Ln= Dy, Tb, Brady D. Garabato

Masters Theses & Specialist Projects

Polyoxoniobates (PONbs) are a small family of highly electron-rich clusters. The development of new solids composed of these clusters have applications in green energy and electronics. However, the high charge environment of PONbs typically requires alkaline synthetic conditions that are unsuitable for introducing other metals and organic molecules, making synthesis of new systems difficult. To date, very few transition metals and organic ligands have been incorporated into these PONb solids, and lanthanide metal inclusion, which generally improves photoconductivity due to longlived f-orbital excitations, has not yet been fully realized. Here, the synthesis of a new class of lanthanide niobate cluster …

Characterization By Nmr Of Reactants And Products Of Hydrofluoroether Isomers, Cf3(Cf2)3och3 And (Cf3)2c(F)Cf2och3, Reacting With Isopropyl Alcohol, Howard Knachel, Vladimir Benin, William E. Moddeman, Janine C. Birkbeck, Thomas A. Kestner, Tayna L. Young

Chemistry Faculty Publications

The 3M Company product Novec™ 71IPA DL, a mixture of methoxyperfluorobutane, methoxyperfluoroisobutane and 4.5 wt.% isopropyl alcohol, has been found to be very stable at ambient temperature, producing fluoride at the rate of ~1 ppm/year. Our earlier kinetic and theoretical studies have identified the reaction mechanism. This paper identifies the ¹H and ¹⁹F NMR chemical shifts, multiplicities, and coupling constants of reactants and the major products that result from aging the mixture in sealed Pyrex NMR tubes for periods up to 1.8 years at temperatures from 26 °C to 102 °C. Chemical shifts and coupling constants of fluorine …

Redesigned Storm Water Management System For The Portage Lakefront, Nicholas Adams, Agustin Perez Maldonado

Symposium on Research and Creative Expression (SORCE)

The work described here was carried out at the Indiana Dunes National Lakeshore, located near Gary, Indiana. The goal of the reported project was to fix an incorrectly designed storm water management system located at the Portage lakefront. Because the original design could not handle peak water flows, there has been erosion of the sand dunes. The erosion of the sand dunes has led to the collapsing of stairs, and the exposure of water mains. To fix these problems, a new design was made that incorporated additional water inlets, as well as a pipeline to take water to a different …

Probing The Low Temperature Oxidation Of Furanic Biofuels, 2-Methyltetrahydrofuran And 2,5-Dimethylfuran, Utilizing Orthogonal Time-Of-Flight Mass Spectrometry Coupled To Synchrotron Radiation, Matthew Mcmanus

Master's Theses

Concern over natural resources and global climate shifts has increased the focus of sourcing transportation fuels from depleting oil wells to regenerative, biological based solutions. One avenue of biologically sourced fuel involves the extraction of C5 and C6 sugars from the woody, fibrous, and inedible plant materials, otherwise known as lignocellulosic biomass. These cellulosic sugars can be converted to target biofuels and biofuel additives like the furanic compounds, 2,5-dimethylfuran and 2-methylfuran. In this thesis, the low temperature oxidation of two compounds, 2,5-dimethylfuran and 2-methylfuran, are explored. These reactions were conducted at the Advanced Light Source in Berkeley, CA and used …

Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo

Senior Honors Projects

Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue …

Interaction Between Lubricants Containing Phosphate Ester Additives And Stainless Steels, David W. Johnson, Matthew Bachus, John E. Hils

Chemistry Faculty Publications

One way to improve fuel efficiency in today’s jet aircraft engines is to create an environment for higher operating temperatures and speeds. New and improved lubricants and bearing materials must be developed to remain stable in these elevated operating temperatures. Three lubricants, with varying amounts of tricresyl phosphate added as an anti-wear/extreme pressure additive were tested on two different stainless steels at varying temperatures ranging from 300 °C to 350 °C in vacuum. Significant decomposition of the lubricant base-stocks and the phosphate ester additive did occur in most of the trials resulting in the formation of carboxylic acids and phenols. …

A Combined Radio- And Stable-Isotopic Study Of A California Coastal Aquifer System, Peter W. Swarzenski, Mark Baskaran, Robert J. Rosenbauer, Brian D. Edwards, Michael Land

Environmental Science and Geology Faculty Research Publications

Stable and radioactive tracers were utilized in concert to characterize geochemical processes in a complex coastal groundwater system and to provide constraints on the kinetics of rock/water interactions. Groundwater samples from wells within the Dominguez Gap region of Los Angeles County, California were analyzed for a suite of major cations (Na⁺, K⁺, Mg²⁺, Ca²⁺) and anions (Cl⁻, SO₄²⁻), silica, alkalinity, select trace elements (Ba, B, Sr), dissolved oxygen, stable isotopes of hydrogen (δD), oxygen (δ¹⁸O), dissolved inorganic carbon (δ¹³C_DIC), and radioactive …

A Computational Study Of The Vibrational Spectra Of Mono-Nitrated Fluoranthenes, Jorge Ojeda

Undergraduate Research Conference

No abstract provided.

Cycling Of Molecular Hydrogen In Subarctic Sweden, Victoria Ward

Honors Theses and Capstones

No abstract provided.

Soil Chemistry Response To Wollastonite (Casio3) Addition At Hubbard Brook, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR Program Research Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on …

Utilising Caging Techniques To Investigate Metal Assimilation In Nucella Lapillus, Mytilus Edulis And Crassostrea Gigas At Three Irish Coastal Locations, Michelle Giltrap, Ailbhe Macken, Maria Davoren, Evin Mcgovern, Barry Foley, Martin Larsen, Jonathan White, Brendan Mchugh

Articles

Pollution by metals has been of increasing concern for a number of decades but at present, the mechanism of metal accumulation in sentinel species is not fully understood and further studies are required for environmental risk assessment of metals in aquatic environments. The use of caging techniques has proven to be useful for assessment of water quality in coastal and estuarine environments. This study investigates the application of caging techniques for monitoring uptake of 20 elements in three marine species namely Nucella lapillus, Mytilus edulis and Crassostrea gigas. Stable isotopes were used to determine predatory effects and also used for …

Insights Into Forest Soil Carbon Dynamics From Nuclear Magnetic Resonance Spectroscopy, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Oil Pollution In Water Bodies Of Restricted Circulation, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Coastal lagoons and embayments near urban centers around the world share many common characteristics and problems. Physical impediments to free water circulation (spits, barrier islands, internal islands, tombolos, submerged sills) often lead to water stagnation and, in the presence of excess nutrients, eutrophication. Urban and industrial activities provoke (usually accidental) spills of hazardous materials into these confined water bodies, such as crude petroleum and refined petroleum products, leading to difficulties for resident biota and potential hazards for human health. The sluggish turnover of these water bodies (or low-energy zones within them) may retard the natural attenuation of the spilled contaminants. …

Study Of Dieldrin In Coralville Reservoir, Jeremy Smith

Undergraduate Journal of Mathematical Modeling: One + Two

Using existing experimental data taken over a period of roughly 12 years that documents the concentrations of dieldrin levels in the environment and fatty tissue of the fish, we construct a model of the total dieldrin concentration decline. Comparisons between the experimental data and speculative data can be made using calculus and elements of statistics in order to better understand the movement of dieldrin in the reservoir. Because of the potentially harmful exposure effects of dieldrin to humans as well as the environment, it is important to be able to predict when stability has been restored to the ecosystem.

Preparation Of Phosphonoterephthalic Acids Via Palladium-Catalyzed Coupling Of Aromatic Iodoesters, Nathaniel Ivan, Vladimir Benin, Alexander Morgan

Chemistry Faculty Publications

The current article reports in detail the preparation of two phosphonoterephthalic acids: 2-phosphonoterephthalic acid (1) and 2,5-diphosphonoterephthalic acid (2). Efficient, scalable syntheses have been developed for both compounds based on Pd-catalyzed coupling reactions of iodinated terephthalate esters. Phosphonoterephthalic acids are potentially useful as flame-retardant additives or as monomers for the construction of acid-pendant polymer chains.

Use Of Sweet Potato To Develop A Medium For Cultivation Of Lactic Acid Bacteria, Saeed A. Hayek

Dissertations

This study investigated the use of sweet potatoes (Ipomoea batatas) as a basic component to develop a medium for cultivation of lactic acid bacteria (LAB). Extract from baked sweet potatoes was used to form a sweet potato medium (SPM). SPM was supplemented with 4 g/L of each nitrogen source (beef extract, yeast extract, and proteose peptone #3). Lactobacilli MRS was used as a control medium. Ten LAB strains were used to determine the suitability of SPM serving the growth of LAB. Our results showed no significant (p < 0.05) differences in the optical density, maximum specific growth rates, and bacterial populations between MRS and SPM. SPM also maintained higher pH values throughout the incubation period compared to that in MRS. The cost of SPM was 47% less than the cost of MRS. Further step was taken to determine the suitability of SPM serving LAB enzymatic activity. LAB strains growing in SPM showed relatively higher β-glucosidases, acid phosphatase, and phytase activities and lower a-glucosidase compared to that in MRS. Strains of L. reuteri showed the …

Reaction Between Polyol-Esters And Phosphate Esters In The Presence Of Metal Carbides, David W. Johnson, Carolyn Iacullo, John E. Hils

Chemistry Faculty Publications

The reaction of metal carbides with polyol esters found in aerospace lubricants and phosphate esters commonly used as additives was investigated. Carbides were of particular interest since modern materials under consideration at high temperature bearings have surfaces that are primarily metal carbides. Vanadium and chromium carbide were found to react with the ester and phosphate ester by a transesterification reaction, producing an alkyl phosphate which is less stable than the aromatic phosphate esters. In the process, the metal carbide is converted to the metal phosphate and metal polyphosphate, evidenced by the infrared and Raman spectra of the solid residue and …

Air-Sea Dimethylsulfide (Dms) Gas Transfer In The North Atlantic: Evidence For Limited Interfacial Gas Exchange At High Wind Speed, T. G. Bell, Warren J. De Bruyn, S. D. Miller, B. Ward, K. Christensen, E. S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Shipboard measurements of eddy covariance dimethylsulfide (DMS) air-sea fluxes and seawater concentration were carried out in the North Atlantic bloom region in June/July 2011. Gas transfer coefficients (k(660)) show a linear dependence on mean horizontal wind speed at wind speeds up to 11 m s(-1). At higher wind speeds the relationship between k(660) and wind speed weakens. At high winds, measured DMS fluxes were lower than predicted based on the linear relationship between wind speed and interfacial stress extrapolated from low to intermediate wind speeds. In contrast, the transfer coefficient for sensible heat did not exhibit this effect. The apparent …

Production Mechanisms, Number Concentration, Size Distribution, Chemical Composition, And Optical Properties Of Sea Spray Aerosols, Nicholas Meskhidze, Markus D. Petters, Kostas Tsigaridis, Tim Bates, Colin O'Dowd, Jeff Reid, Ernie R. Lewis, Brett Gantt, Magdalena D. Anguelova, Prakash V. Bhave, Andrew Wozniak

Chemistry & Biochemistry Faculty Publications

(First paragraph)

The impact of sea spray aerosols on global climate remains one of the most uncertain components of the aerosol–radiation–climate problem, but has received less attention than the impacts of terrestrial and anthropogenic aerosols. The last decade has produced a large body of information regarding the sources and composition of marine aerosols, resulting in a reassessment of the complex role that sea spray particles play in climate and various geophysical phenomena. As sea spray aerosol contributes substantially to the preindustrial, natural background which provides the baseline on top of which anthropogenic forcing should be quantified, and because the ocean …

Quantifying The Impact Of Boreal Forest Fires On Tropospheric Oxidants Over The Atlantic Using Aircraft And Satellites (Bortas) Experiment: Design, Execution And Science Overview, P. I. Palmer, M. Parrington, J. D. Lee, A, C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, S. Andrews

Chemistry & Biochemistry Faculty Publications

We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned …

Improved Method For Quantifying The Air-Sea Flux Of Volatile And Semi-Volatile Organic Carbon, Emily Hauser, Rebecca M. Dickhut, Renee Falconer, Andrew S. Wozniak

Chemistry & Biochemistry Faculty Publications

A method for quantifying the diffusive air-sea exchange of gaseous organic carbon (OC) was developed. OC compounds were separated into two operational pools-those that were kinetically air limited in diffusion across the air-sea interface and those that were water limited-during simultaneous air/water sampling. The method separates OC compounds into low Henry's law constant (low-H) semivolatile OC (SOC) and high Henry's law constant (high-H) volatile OC (VOC) pools that can be categorized by relating diffusion kinetic parameters to Henry's Law constant. Air limited (low-H; H << similar to 0.1 L atm mol(^-1)) compounds were collected in pure water traps and were quantified as dissolved OC, whereas …

Transformations, Bioavailability And Toxicity Of Manufactured Zno Nanomaterials In Wastewter, Sewwandi Rathnayake

Theses and Dissertations--Plant and Soil Sciences

In order to properly evaluate the ecological and human health risks of ZnO Manufactured nanomaterials (MNMs) released to the environment, it is critical to understand the likely transformation products in the wastewater treatment process and in soils receiving biosolids. To address this critical knowledge gap, we examined the transformation reactions of 30 nm ZnO MNMs in single component and multi-component systems, with phosphate and natural organic matter (NOM). We also assessed the influence of nano ZnO transformation on the bioavailability, and toxicity of ZnO transformation products to Triticum aestivum. The data revealed that ZnO MNMs react with phosphate at …

Self-Assembling Of Gold Nanoparticles Array For Electro-Sensing Applications, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

A colloidal solution of citrate-stabilized gold nanoparticles (AuNPs) with an average size of ca. 2.6 nm has been prepared, characterized and further implemented in electro-sensing applications. This colloidal solution of AuNPs has been prepared via the reduction of NaAuCl4 with sodium tetrahydroborate (NaBH4) using trisodium citrate as a stabilizer. The optical properties of this solution have been studied with UV–Vis spectroscopy. Next, these AuNPs have been immobilized onto a polycrystalline Au (poly-Au) electrode with the assistance of benzenedimethanethiol (BDMT), which served as a binder. Attention has been taken to ensure the formation of a compact impermeable layer of BDMT on …

Novel Microwave Assisted Synthesis Of Zns Nanomaterials, Suresh Pillai, Michael Seery, Damian Synnott, John Colreavy, Stephen Hinder

Articles

A novel ambient pressure microwave-assisted technique is developed in which silver and indium modified ZnS is synthesised. The as prepared ZnS is characterised by X-ray diffraction, UV-Vis spectroscopy, X-ray photoelectron spectroscopy and luminescence spectroscopy. This procedure produced crystalline materials with particle sizes below 10 nm. The synthesis technique leads to defects in the crystal which induce mid energy levels in the band gap and lead to indoor light photocatalytic activity. Increasing the amount of silver causes a phase transition from cubic blende to hexagonal phase ZnS. In a comparative study, when the ZnS cubic blende is heated in a conventional …

Treatment Of Reverse Osmosis Brine With Advanced Oxidative Processes For Enhanced Phosphorus Removal, Petrease Patton

Theses and Dissertations (Comprehensive)

Current regulations for sensitive receiving waters are approaching the limit of technology for phosphorus removal and improved methods are required. Existing methods target removal of the orthophosphate form of phosphorus, but to achieve low effluent limits other non-reactive (NRP) forms, such as condensed phosphate and organic phosphorus, must be removed as well. This could be accomplished by developing a quaternary step in wastewater treatment that utilizes reverse osmosis (RO) followed by advanced oxidation processes (AOP) on the produced brine (RO concentrate). The objective during advanced treatment is to convert NRP in the brine to reactive phosphorus for removal by traditional …

Determination Of Copper Speciation, Bioavailability And Toxicity In Saltwater Environments, Tara N. Tait

Theses and Dissertations (Comprehensive)

The speciation of copper plays a strong role in determining bioavailability and toxicity upon copper exposure in marine environments. Specifically, natural organic matter (NOM) can complex with copper, influencing speciation and decreasing bioavailability. The aim of this research was to determine accurate copper speciation values using literature and new techniques and applying the techniques that reflect the most accurate speciation values to investigate the influence of NOM quantity and quality on copper speciation and toxicity. The results from this study will have implications on the development of a marine Biotic Ligand Model (BLM). Free copper was measured using a flow-through …

Urban Runoff Treatment Using Nano-Sized Iron Oxide Coated Sand With And Without Magnetic Field Applying, Mehdi Khiadani, Mansur Zarrabi, Maryam Foroughi

Research outputs 2013

Increase of impervious surfaces in urban area followed with increases in runoff volume and peak flow, leads to increase in urban storm water pollution. The polluted runoff has many adverse impacts on human life and environment. For that reason, the aim of this study was to investigate the efficiency of nano iron oxide coated sand with and without magnetic field in treatment of urban runoff. In present work, synthetic urban runoff was treated in continuous separate columns system which was filled with nano iron oxide coated sand with and without magnetic field. Several experimental parameters such as heavy metals, turbidity, …

Application Of Glycyrrhiza Glabra Root As A Novel Adsorbent In The Removal Of Toluene Vapors: Equilibrium, Kinetic, And Thermodynamic Study, Fazel Mohammadi-Moghadam, Mohammad Mehdi Amin,, Mehdi Khiadani, Fariborz Momenbeik, Heshmatollah Nourmoradi, Mohammad Sadegh Hatamipour

Research outputs 2013

The aim of this paper is to investigate the removal of toluene from gaseous solution through Glycyrrhiza glabra root (GGR) as a waste material. The batch adsorption experiments were conducted at various conditions including contact time, adsorbate concentration, humidity, and temperature. The adsorption capacity was increased by raising the sorbent humidity up to 50 percent. The adsorption of toluene was also increased over contact time by 12 h when the sorbent was saturated. The pseudo-second-order kinetic model and Freundlich model fitted the adsorption data better than other kinetic and isotherm models, respectively. The Dubinin-Radushkevich (D-R) isotherm also showed that the …

Treatment Of Synthetic Urban Runoff Using Manganese Oxide-Coated Sand In The Presence Of Magnetic Field, Maryam Foroughi, Mehdi Khiadani, Mohammad Mehdi Amin, Hamid Reza Pourzamani, Marzieh Vahid Dastjerdi

Research outputs 2013

Aims: The purpose of this study was to investigate the efficiency of manganese oxide‑coated sand in the presence of magnetic field to treat urban runoff. Materials and Methods: A flow‑through column having a diameter of 50 mm was filled with coated sand and used to conduct the experiments in this study. Atomic absorption, turbidimeter, pH meter, and spectrophotometer DR5000 were used to measure heavy metals, turbidity, pH, phosphate, and nitrate, respectively. The surface of coated sand was assessed by SEM. Energy dispersive X‑ray analysis (EDAX) analysis was used to determine percentage of sand components. Results: SEM and EDAX analyses confirmed …