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Masters Theses

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Articles 691 - 720 of 2077

Full-Text Articles in Physical Sciences and Mathematics

Backstripping The Chesapeake Bay Impact Structure: Differentiating Regional Tectonics From Impact Effects, Travis Gary Hayden Apr 2008

Backstripping The Chesapeake Bay Impact Structure: Differentiating Regional Tectonics From Impact Effects, Travis Gary Hayden

Masters Theses

The Chesapeake Bay impact structure is a ca. 35.4 Ma old crater located on the coastal plain of Virginia along the eastern seaboard of North America. The impact generated a crater between 85 and 90 km in diameter, and over 2000 meters deep. Deposition returned to normal shortly after impact, resulting in a unique record of both the impact related and subsequent passive margin sedimentation. We use backstripping to show that the impact strongly affected sedimentation for 7 m.y. through a combination of impact derived crustal scale tectonics, dominated by the introduction and subsequent removal of a negative thermal anomaly, …


Real-Time Analysis And Investigation Of The Mechanism Of The Palladium On Carbon Catalyzed Isomerization Of Megestrolacetate, Charlene K. Wiglesworth Apr 2008

Real-Time Analysis And Investigation Of The Mechanism Of The Palladium On Carbon Catalyzed Isomerization Of Megestrolacetate, Charlene K. Wiglesworth

Masters Theses

Megestrol Acetate is a semi-synthetic steroid hormone of the progestin family and currently used as a drug therapy in many areas including treatments of cancers and AIDS. The final step to form the bulk drug is an isomerization using palladium on carbon with cyclohexene as an activator. This step is sensitive to catalyst quality and is hazardous to sample because of the reactivity of the catalyst. Physical and catalytic properties of the catalyst were evaluated, as were the effects of solid support and different washing strategies. Response of the reaction mixture to catalyst poisons was studied as a function of …


Lateral Reservoir Compartmentalization Of The Woodford Shale In The Arkoma Basin, Southeastern Oklahoma, Adedapo Omotunde Ajibade Jan 2008

Lateral Reservoir Compartmentalization Of The Woodford Shale In The Arkoma Basin, Southeastern Oklahoma, Adedapo Omotunde Ajibade

Masters Theses

"Analysis of geochemistry, mineralogy, total organic content (TOC) and rock evaluation pyrolysis on Woodford Shale well cuttings taken from a horizontal well (Quaid 13-30H) drilled in the Arkoma Basin (Pittsburg County), Oklahoma shows no significant variation in the thermal maturity, type, and/or quantity of organic matter. This is interpreted to mean that the organic matter of the Woodford Shale is relatively homogeneous and has all undergone similar thermal history. In addition, the analysis shows that there are lateral variations in the gas geochemistry in which the shale appears to be broken up into sections, some of which are more enhanced …


The Carbonatite-Hosted Apatite Deposit Of Jacupiranga, Se Brazil: Styles Of Mineralization, Ore Characterization And Association With Mineral Processing, Paula Regina Alves Jan 2008

The Carbonatite-Hosted Apatite Deposit Of Jacupiranga, Se Brazil: Styles Of Mineralization, Ore Characterization And Association With Mineral Processing, Paula Regina Alves

Masters Theses

"The carbonatite-hosted apatite deposit of Jacupiranga is located in southeastern Brazil. The major styles of apatite mineralization are veins or veinlets, small pods or patches, disseminated apatite, and massive aggregates (locally). The concentration of apatite involves grinding of the carbonatite, removal of magnetite with a magnet drum, size classification with cyclones, and flotation to suppress carbonates and collect apatite. Samples of carbonatite were collected from more recent exposures of the mine and drill holes. This study utilized a variety of microscopy methods, namely transmitted and reflected light, cathodoluminescence (CL), and scanning electron microscopy (with wavelength-dispersive spectrometers for mineral compositions)"--Abstract, page …


Preserd - Privacy Ensured Service Discovery In Mobile Peer-To-Peer Environment, Santhosh Muthyapu Jan 2008

Preserd - Privacy Ensured Service Discovery In Mobile Peer-To-Peer Environment, Santhosh Muthyapu

Masters Theses

"In mobile peer-to-peer networks many service discovery protocols have been proposed. Most of these protocols disregard the exposure of the participating peers' privacy details, although they consider the security issues. In these methods, the participating peers must provide their identities, during the service discovery process, to be authorized to utilize the service. However, a peer might not be willing to reveal its identity until it identifies the service providing peer. So these peers face a problem; should the requesting peer or the service providing peer reveal the identity first, and hence, this is similar to the chicken-and-egg problem. The protocol …


The Identification And Characterization Of Phenylalanine Ammonia-Lyase Gene Family Members In Glycine Max, Erin Kathleen Pringle Jan 2008

The Identification And Characterization Of Phenylalanine Ammonia-Lyase Gene Family Members In Glycine Max, Erin Kathleen Pringle

Masters Theses

"Gene families are collections of genes with similar functions. Studying gene families is important for understanding the evolution of genes and manipulating genes. Phenylalanine ammonia-lyase (PAL) is an enzyme found in plants. It catalyzes the deamination of phenylalanine to produce cinnamic acid. Genes for PAL have been identified in many different plant species. This project used the known sequence for the PAL1 gene in Glycine max to find other PAL genes in Glycine max"--Abstract, page iii.


Image Analysis Techniques For Vertebra Anomaly Detection In X-Ray Images, Mohammed Das Jan 2008

Image Analysis Techniques For Vertebra Anomaly Detection In X-Ray Images, Mohammed Das

Masters Theses

"In this research, imaging techniques are investigated for the analysis and detection of abnormalities in cervical and lumbar vertebrae. Detecting vertebra anomalies pertaining to osteoarthritis such as claw, traction and anterior osteophytes can aide in treatment plans for the patient. New size invariant features were developed for the detection of claw, traction and anterior osteophytes in cervical spine vertebrae. Using a K-means clustering and nearest centroid classification approach, the results were generated that were capable of discriminating cervical vertebrae for presence of anomalies related to osteophytes. The techniques developed can be integrated into systems based on querying spine images to …


Dynamic Equations With Piecewise Continuous Argument, Christian Keller Jan 2008

Dynamic Equations With Piecewise Continuous Argument, Christian Keller

Masters Theses

"We extend the theory of differential equations with piecewise continuous argument to general time scales. Linear and quasi-linear systems of functional dynamic equations with alternating retarding and advanced argument will be investigated and conditions for globally asymptotic stability of those systems will be stated and proven. Furthermore, oscillation criteria for linear first-order equations with piecewise continuous argument will be established"--Abstract, page iii.


A Rapid Method For Determination Of Alpha Hydroxy Acids In Seawater And Biological Fluids At Trace Levels, Ryan Lee Schwiderski Jan 2008

A Rapid Method For Determination Of Alpha Hydroxy Acids In Seawater And Biological Fluids At Trace Levels, Ryan Lee Schwiderski

Masters Theses

"Alpha hydroxy acids (AHAs) - carboxylic acids with a hydroxyl substitution on the alpha carbon are an important class of molecules. Hydroxy Methyl Thiobutanoic Acid (HMTBA) is an α-hydroxy analog of essential amino acid methionine; it finds extensive use as a feed supplement for avian and bovine species. Efficacy of alpha hydroxy acid uptake is important for nutritional studies and such studies rely on accurate and precise methods for determination of these chemicals in biological samples. Several methods for AHAs determination have been reported, however, the methods are tedious, requiring multiple sample preparation steps. Experiments reported in this thesis were …


Obscurant Oil Characterization Produced Through Vaporization By Exhaust Gas Of Mini-Jet Turbine Engine, Hossein Daniel Bahaghighat Jan 2008

Obscurant Oil Characterization Produced Through Vaporization By Exhaust Gas Of Mini-Jet Turbine Engine, Hossein Daniel Bahaghighat

Masters Theses

"Obscurants have been used for centuries to conceal and protect military assets from direct enemy attack, or as a signal between units. Obscurants still play a significant role in protecting soldiers on the battlefield. This research was geared towards development of highly efficient man portable obscurant generation system to demonstrate its use with biogenic oils as the obscurants. The research reported in the thesis was directed evaluating the performance of a mini-jet based generator in the laboratory and field with two different obscurant oils, Fog Oil (FO) the oil used by the US Army at present and potential replacement oil …


Co-Evolutionary Automated Software Correction: A Proof Of Concept, Joshua Lee Wilkerson Jan 2008

Co-Evolutionary Automated Software Correction: A Proof Of Concept, Joshua Lee Wilkerson

Masters Theses

"The task of ensuring that a software artifact is correct can be a very time consuming process. To be able to say that an algorithm is correct is to say that it will produce results in accordance with its specifications for all valid input. One possible way to identify an incorrect implementation is through the use of automated testing (currently an open problem in the field of software engineering); however, actually correcting the implementation is typically a manual task for the software developer. In this thesis a system is presented which automates not only the testing but also the correction …


A Time Series Classifier, Christopher Mark Gore Jan 2008

A Time Series Classifier, Christopher Mark Gore

Masters Theses

"A time series is a sequence of data measured at successive time intervals. Time series analysis refers to all of the methods employed to understand such data, either with the purpose of explaining the underlying system producing the data or to try to predict future data points in the time series...An evolutionary algorithm is a non-deterministic method of searching a solution space, and modeled after biological evolutionary processes. A learning classifier system (LCS) is a form of evolutionary algorithm that operates on a population of mapping rules. We introduce the time series classifier TSC, a new type of LCS that …


Critical Infrastructure Protection And The Domain Name Service (Dns) System, Mark Edward Snyder Jan 2008

Critical Infrastructure Protection And The Domain Name Service (Dns) System, Mark Edward Snyder

Masters Theses

"Components of the critical infrastructure of any system are natural targets for attack. Any inherent weakness of such components can potentially expose the entire system to vulnerability. The Domain Name System (DNS) is one component of the proper functioning of the Internet. Although DNS is a relatively simple, isolated component, it serves as a straightforward example for the study of distributed systems in general, and as such, we have explored properties of DNS to examine how enterprise-scale, critical infrastructure components are vulnerable to attack, what protections are afforded to defenders of such components, the inherent weaknesses of such systems, and …


Role Of Microtubules In Budding Yeast Cytokinesis, Su Young Park Jan 2008

Role Of Microtubules In Budding Yeast Cytokinesis, Su Young Park

Masters Theses

"Cytokinesis is an important step to finish cell cycle events and separate into two daughter cells. This event is driven by actomyosin ring contraction. In budding yeast, the mitotic exit network (MEN) controls completion of ana/telophase by signaling events. Bub2 is a mitotic exit network regulator and binds to Tem1p which is an important component in MEN. Mad2 is a component of a separate spindle checkpoint. Mad2 dependent pathway prevents the metaphase to anaphase transition under spindle damage. Because yeast cells have cell walls, septum formation follows actin ring contraction. Here it was investigated how microtubule defects affect cytokinesis in …


Fourier-Transform Microwave Spectroscopy Of Cyclopropylmethylgermane And Van Der Waals Complexes Of Fluorinated Methanes, Michal M. Serafin Jan 2008

Fourier-Transform Microwave Spectroscopy Of Cyclopropylmethylgermane And Van Der Waals Complexes Of Fluorinated Methanes, Michal M. Serafin

Masters Theses

Background theory and instrumentation utilized in the Fourier-transform microwave spectroscopy technique is first introduced followed by the structural and dynamic determination of cyclopropylmethylgermane and two weakly bound van der Waals complexes (difluoromethane-OCS, and fluoromethane-OCS). The minimum energy configuration has been determined for cyclopropylmethylgermane molecule, which has been shown to be the gauche configuration. Internal rotation parameters have been obtained from the rotational spectra of cyclopropylmethylgermane. The rotational spectra have been acquired for difluoromethanecarbonyl sulfide and fluoromethane-carbonyl sulfide and experimental structures have been determined for these weakly bound complexes. Evidence for a very low barrier to internal rotation has been observed …


Synthetic Studies Towards The Stellettins, Tung Yin Lin Jan 2008

Synthetic Studies Towards The Stellettins, Tung Yin Lin

Masters Theses

The synthesis of the stellettins, differing in the side chain at the C-13 position of the tricyclic region, was attempted by attaching the C-ring to a Wieland-Miescher ketone core using 1,3-bisphosphonoacetone. The decalin precursor was prepared in 35% from condensing ethyl acetate with acrolein, and a MnO2 oxidation, but too little material was obtained to cyclize this into the decalin. An alternative route involving a 2-step Robinson annulation of 2-methyl-1,3 cyclohexanedione with ethyl or methyl vinyl ketone and L-phenylalanine catalysis, followed by protecting C-9 carbonyl with acetal, gave 29% and 14% yields respectively.

1,3-Bisphosphonoacetone was prepared m a 3-step synthesis …


Cross-Layer Design Through Joint Routing And Link Allocation In Wireless Sensor Networks, Xuan Gong Jan 2008

Cross-Layer Design Through Joint Routing And Link Allocation In Wireless Sensor Networks, Xuan Gong

Masters Theses

"Both energy and bandwidth are scarce resources in sensor networks. In the past, the energy efficient routing problem has been extensively studied in efforts to maximize sensor network lifetimes, but the link bandwidth has been optimistically assumed to be abundant. Because energy constraint affects how data should be routed, link bandwidth affects not only the routing topology, but also the allowed data rate on each link, which in turn affects the lifetime. Previous research that focus on energy efficient operations in sensor networks with the sole objective of maximizing network lifetime only consider the energy constraint ignoring the bandwidth constraint. …


Co-Optimization: A Generalization Of Coevolution, Travis Service Jan 2008

Co-Optimization: A Generalization Of Coevolution, Travis Service

Masters Theses

"Many problems encountered in computer science are best stated in terms of interactions amongst individuals. For example, many problems are most naturally phrased in terms of finding a candidate solution which performs best against a set of test cases. In such situations, methods are needed to find candidate solutions which are expected to perform best over all test cases. Coevolution holds the promise of addressing such problems by employing principles from biological evolution, where populations of candidate solutions and test cases are evolved over time to produce higher quality solutions...This thesis presents a generalization of coevolution to co-optimization, where optimization …


Textural Analysis Of A Rhyolite Dike Of The Southern Oklahoma Aulacogen At Medicine Park, Oklahoma, Sean Patrick O'Donnell Jan 2008

Textural Analysis Of A Rhyolite Dike Of The Southern Oklahoma Aulacogen At Medicine Park, Oklahoma, Sean Patrick O'Donnell

Masters Theses

"Detailed analysis of the modal abundance and crystal size distribution (CSD) of glomerocrystic quartz and alkali feldspar phenocrysts in a porphyritic "rhyolite" dike at Medicine Park, Oklahoma were integrated with known phase relationships in the system SiO₂-NaAlSi₃O₈-KAlSi₃-O₈-H₂O to constrain the history of this intrusion"--Abstract, page iv.


An Economic Incentive Based Routing Protocol Incorporating Quality Of Service For Mobile Peer-To-Peer Networks, Anil Jade Jan 2008

An Economic Incentive Based Routing Protocol Incorporating Quality Of Service For Mobile Peer-To-Peer Networks, Anil Jade

Masters Theses

"Economic incentive models are becoming increasingly popular in Mobile Peer to Peer Networks (M-P2P). These models entice node participation to combat free riding and to effectively manage constraint resources in the network. Due to the dynamic topology of the M-P2P network, the connections between the peers become unpredictable and therefore, reliable routing becomes important. Many routing protocols proposed earlier (such as DSR, AODV) are based on best effort data traffic policy, such as the shortest route selection (hop minimization). Using economic models to find a cost effective optimal route from the source to the destination, while considering Quality of Service …


Polymer Reinforced Aerogels And Composites A. Polyimide Crosslinked Aerogels B. Silica-Polymethylmethacrylate Composites, Vishal U. Patil Jan 2008

Polymer Reinforced Aerogels And Composites A. Polyimide Crosslinked Aerogels B. Silica-Polymethylmethacrylate Composites, Vishal U. Patil

Masters Theses

"Crosslinking of aerogels is a promising approach to combine the advantages of inorganic and polymeric materials. In the present study, two types of polyimide-silica hybrid aerogels, APTES-BTDA-MDA (mol ratio: 2:2:1) and APTES-BTDA-MDA (mol ratio: 2:3:2), were synthesized using a sol-gel process followed by heating in order to imidize the polyamic acid that is formed quickly and is covalently bonded to silica. The hybrid aerogels were made using 3-aminopropyltriethoxysilane (APTES) endcapped polyamic acids and tetramethoxysilane (TMOS) as precursors. Polyimide crosslinked aerogels were characterized by TGA, SEM, FT-IR, BET, solid state NMR and gas pycnometry. These hybrid aerogels exhibit high thermal stability …


Synthesis And Characterization Of Ruthenium Bipyridyl Complexes For Detecting Nerve Gas Agents And Explosives, Arambe Gedara Aruna Weerasinghe Dec 2007

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 …


The Effect Of A Skyrme Interaction On Nucleon Induced Reactions, Yingfa Zhang Dec 2007

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 …


Nanosensors For The Detection Of Nerve Agents And Explosives, Deepak Kumar Thimmaraju Dec 2007

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. …


Fundamental Investigation Of Vesicle Bilayer Membrane Dynamics, Wilson Okumu Dec 2007

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 …


Design Of Multi-Electron Transfer Catalysts For The Reduction Of Trichloroethylene, Christopher Gerard Eman Ciptadjaya Dec 2007

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 …


Nanomaterial Composites For The Detection Of Nerve Gas Analogs, Yogesh Datar Dec 2007

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 …


Estimating Sea Level Due To Crustal Stretching In The Margin Of The Indian Ocean, Kisa Mwakanyamale Dec 2007

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 Aug 2007

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 Aug 2007

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). …