Physical Sciences and Mathematics Commons^™

Nanomaterial Composites For The Detection Of Nerve Gas Analogs, Yogesh Datar

Masters Theses

The basis of the research work described here is the use of nanocomposite materials built by bottom-up approach for the selective detection of nerve gas analogs. Nanocomposites materials constructed by using nanoparticle-monomer-receptor (NMR) concept have been utilized to detect nerve gas analogs DCP and DMMP. Synthetic approach used in the construction of nanosensors involved use of robust platforms such as silica nanoparticles and fluorescent quantum dots. Highly conjugated receptor molecules were synthesized by using stilbeneoid compounds. A complete opto-nanosensor was developed by anchoring highly conjugated receptor molecules onto the silica nanoparticles as well as onto the quantum dots. The opto-nanosensors …

Synthesis And Characterization Of Ruthenium Bipyridyl Complexes For Detecting Nerve Gas Agents And Explosives, Arambe Gedara Aruna Weerasinghe

Masters Theses

Five novel 2,2 '-bis bi pyridine Ru(II) complexes have been synthesized and characterized using ¹H NMR, ¹³C NMR, ¹H-¹H-COSY, elemental analysis, fast atom bombardment or electrospray mass spectra and electronic absorption spectroscopy. Binding of Ru (11) complexes with nerve gas analogos such as diethyl chlorophosphate (DCP), dimethyl methyl phosphonate (DMMP) and hydrolyzed product (HCl) has been investigated by electronic absorption, fluorescence, and lifetime studies. Compound 1 showed a quenching in ³MLCT emission after an initial increase in intensity upon the addition of DCP with a bathochromic shift of 25 nm. Compound 2 exhibit a …

Design Of Multi-Electron Transfer Catalysts For The Reduction Of Trichloroethylene, Christopher Gerard Eman Ciptadjaya

Masters Theses

For decades, organohalide (RX) compounds have been heavily used in the chemical and pharmaceutical industries and in agriculture as pesticides. Improper disposal of organohalides has resulted in their presence in the environment as pollutants, and they have therefore presented serious environmental and toxicological concerns. These organohalides have been associated with various health and environmental problems. Therefore, effective methods for their remediation are required. We have developed a multi-electron transfer (MET) catalyst consisting of flavin mononucleotide anchored to nanocrystalline mesoporous titanium dioxide (TiO₂) thin films, and examined its reactivity toward the organohalide pollutant trichloroethylene (TCE). Various environmental factors were …

Nanosensors For The Detection Of Nerve Agents And Explosives, Deepak Kumar Thimmaraju

Masters Theses

The central hypothesis of this research was development of a novel nanosensor for the detection of nerve agents and explosives. The nanosensor assembly comprises a bottom up approach with nanoparticle (N), monomer (M), nanomolecule (N) and a receptor (R) as moieties of a NMNR assembly. My research was focused on evaluating receptors for their efficiency towards the target analytes such as nerve agents and explosives. Pi electron rich receptor 2-Phenyl-2-Propanol and its fluorinated analog 1,1,1,3,3,3-Hexafluoro-2-Phenyl-2-Propanol were investigated for their ability to detect nerve agents such as DCP, its analogs DMMP and HCl along with the explosives mono, di, and trinitrotoluene. …

The Effect Of A Skyrme Interaction On Nucleon Induced Reactions, Yingfa Zhang

Masters Theses

The main goal of this Master thesis is the theoretical study of the interaction between a nucleon and a nucleus. This is a fundamental method to study the structure and dynamics of nuclear systems. This thesis concentrates on the study of nucleon scattering on light nuclei, ⁶Li, ⁷Li and ¹⁴N, with the effective interaction M3Y and its modification by adding a Skyrme force. This is the first time the Skyrme interaction has been employed in scattering calculations. From a comparison of the measured differential cross section σ (θ) and the analyzing power Ay (θ) for ⁶Li …

Fundamental Investigation Of Vesicle Bilayer Membrane Dynamics, Wilson Okumu

Masters Theses

We studied the bilayer of vesicles from dimyristolyphosphatidylcholine (DMPC), using nitrobenzoxadiazole (NBD) probes, attached to the head (NBD-PE) and the tail (NBD-PC) of phospholipid derivatives. We characterized the bilayer as it underwent reversible transition from the gel to the fluid through a phase transition range. The main phase transition was characterized by steady state and timeresolved fluorescence anisotropy, fluorescence intensity decrement and kinetics of dithionite reduction. We also studied DMPC with dihydrocholesterol. Differences between the surface and interior regions of the bilayer region were obtained. The activation barrier was enthalpic in the gel, entropic in the fluid phase and anomalous …

Estimating Sea Level Due To Crustal Stretching In The Margin Of The Indian Ocean, Kisa Mwakanyamale

Masters Theses

Continental crust extension is a precursor to the formation of a new ocean. The overall crustal extension causes change in the volume of global oceans hence change in sea level. The break-up of Gondwana that began during Late Triassic to Early Jurassic time caused continental crustal extension prior to forming the Indian Ocean. Extension started 184 Ma with rifting between SE Africa, Madagascar and Antarctica. This was followed by rifting between Greater India, Australia and Antarctica beginning about 160 Ma. The most recent episode of extension occurred 34 Ma involving separation between Arabia and Horn of Africa. Gridded data sets …

Synthesis And Characterization Of Doped Core/Shell Quantum Dots, Elizabeth J. Sodt

Masters Theses

The central theme of the research performed is the systematic modification of the optical properties of quantum dots by the formation of a shell of another quantum dot of a different band gap energy. Core/shell quantum dots such as CdS:Mn/CdS, CdS:Mn/ZnS, and ZnS:Mn/CdS with various concentrations of dopant Mn²⁺ in the core and shell concentrations have been synthesized under mild conditions in the aqueous phase using stoichiometric amounts of the surfactant stabilizer dodecyl sulfate. These quantum dots exhibit UV-vis, emission, and electron paramagnetic resonance (EPR) spectral behavior that is dependent on the concentration of the shell and the dopant …

Nitrogen Heterocyclic Compounds As Receptors In Nanosensors For Nerve Gas Agent Analogs, Swapna Katram

Masters Theses

The research is focused on developing nanosensors consisting of different components that are chemically linked, namely, nanoparticle, fluorescent monomer, and receptor (NMR sensors) and nanoparticle, monomer, nanomolecule, and receptor (NMNR sensors) for the sensitive and selective detection of nerve gas agents. These sensors detect the target toxins by fluorescence change which is amplified by signal transduction. Model nerve gas toxins (DCP) and (DMMP) and HCl were employed as analytes, and the nitrogen heterocyclic compounds, 5-aminoindazole and dipyrido[3,2-a:2',3'-c]phenazine (dppz) as receptors in the NMR and NNMR nanosensors. The monomers were (E)-4-(4- formylstyryl) benzoic acid (NMR sensor) and 2-mercaptosuccinic acid (NNMR sensor). …

Towards A Better Understanding Of The Hydrology Of The Tigris- Euphrates System And Its Marshlands, Christopher K. Jones

Masters Theses

Rising demands for fresh water supplies are leading to water management practices that are altering natural flow systems world-wide. One of the most devastated of these natural systems is the Tigris-Euphrates watershed that over the past three decades has witnessed the construction of over 60 engineering projects that eliminated seasonal flooding, reduced natural flow and dramatically reduced the areal extent (1966: 11000 km² ; 2002: 750 km²) of the Mesopotamian Marshes downstream. We constructed a continuous (1964 to 1998) catchment-based rainfall runoff model for the entire Tigris-Euphrates watershed (area: one million km²) using the SWAT …

Heterogeneous Formation Of Hono On Hno3 Pre-Conditioned Hydrophobic, Hydrophilic And Ionic Surfaces At Various Relative Humidities, Dustin S. Wier

Masters Theses

Nitric acid (HNO₃) is a major sink for NO_x (NO+NO₂ ) and is known to be removed from the atmosphere as a result of wet and dry deposition where it is then deposited on various surfaces in the environment. As these surfaces are photolyzed HONO is produced which affects the overlying troposphere. This study examines the amount of HONO (Nitrous Acid) produced by the photolysis of adsorbed HNO₃ as a function of changing relative humidity on hydrophobic, hydrophilic, and inorganic ionic salt surfaces. The amount of HONO produced was measured in long path cell using …

Transcriptional Regulation Of Glucose-6-Phosphate Dehydrogenase (G6pdh) By Glucose, Pramod U. Thekkat

Masters Theses

In liver, insulin and glucose regulate the expression of important genes for lipid and carbohydrate homeostasis. Studies on the effects of glucose and insulin, including effects on cell signaling, are vital since deficiencies in glucose utilization in cells and/or insulin secretion contribute to conditions like obesity and diabetes. In liver, the pentose phosphate pathway is one of the primary pathways that can utilize the excess carbohydrate. Glucose-6-phosphate dehydrogenase (G6PDH) is an important rate limiting enzyme in this pathway. Our laboratory has shown that both insulin and glucose induce the expression of G6PDH, although the mechanism by which this transcriptional regulation …

Stratigraphy And Organic Carbon Contents Of Glacial Deposits In The City Of Portage, Michigan, U.S.A., Nathaniel A. Barnes

Masters Theses

The objectives of this study are to characterize the stratigraphy of the glacial drift in an area located in Portage, Michigan using four complete rotasonic cores, and to determine the variation of organic carbon content in the drift that may explain the high iron concentrations in the groundwater typically obtained in moderate to deep wells in southwestern Michigan. The four cores were characterized in detail in terms of lithology, textural and statistical analyses, gamma ray logging, S¹³C variation and organic carbon analyses. Clay minerals were characterized using X-ray diffraction analysis.

Results of this study identified two main diamicton …

Development Of Scanning Electrochemical Microscopy For Studying Electron Transport In Lipid Monolayers And Gold Nanoparticle Films, Violeta Stoycheva

Masters Theses

The focus of this thesis is the scanning electrochemical microscopy (SECM) investigation of the electron transport in lipid monolayers and in films of gold nanoparticles. The quality and stability of lipid monolayers were characterized by various analytical techniques such as fluorescence microscopy and spectroscopy, contact angle, and electrochemistry using a monolayer modified electrode. In the SECM measurement, the monolayer electron transport was not detected. The microscopic monolayer quality turned out to be not suitable for studying the electron transport.

The conductivity of mono layer protected gold clusters (MPCs) with different core sizes (1-3 nm diameter) were investigated using SECM. These …

Biochemical Characterization Of Disease-Causing Mutation In N-Terminal Wilson Protein Domain Six, Patrick Ochieng

Masters Theses

Wilson protein (ATP7B) is a copper-transporting P-type ATPase that regulates copper homeostasis and secretion of copper-containing enzymes in the liver. In hepatocytes, ATP7B delivers copper to apoceruloplasmin and mediates the excretion of excess copper into bile. Mutation in the gene coding for Wilson protein leads to Wilson disease. Several mutations in Wilson protein have been identified and of particular interest, mutations affecting the N-metal binding region significantly interfere with the ability of Wilson protein to transport copper to its target in the copper-trafficking pathway. In an attempt to characterize the disease-causing mutation (G591D) in Wilson protein domain 6 (WLN6), we …