Physical Sciences and Mathematics Commons^™

Multiple Differential Study Of Fragmentation Processes In 75 Kev Proton-Molecular Hydrogen Collisions, Kisra Nayomal Egodapitiya

Doctoral Dissertations

"Double Differential Cross Sections (DDCS) were measured for single ionization of H₂ by 75 keV proton (p) impact as a function of the projectile scattering angle (θp) for a fixed energy loss (ΔE) for two different target-collimating slit distances, which determined the width of the projectile wave packet (Δx). In one case Δx was larger than the inter-nuclear separation of the H₂ molecule (coherent projectile beam), while for the other case it was much smaller than the inter-nuclear separation (incoherent projectile beam). A Young type interference pattern was observed in the coherent data, but this was not present in the …

Two New Spline-Based Methods And Real Data Applications: High-Resolution Receiver Function Calculations From Teleseismic Broadband Waveforms And High-Accuracy Practical Potential-Field Integral Transformations, Bingzhu Wang

Doctoral Dissertations

"While receiver function (RF) calculation is fundamentally important and widely used, it is not well solved due to unstable deconvolution. A spline-based RF calculation method was proposed and it is demonstrated that both individual RFs and the stacked RF calculated with the spline method have sharper peaks than those with the water-level spectral division method and the iterative deconvolution method. At the common peaks on the stacked RFs, there are close similarities for all three RF calculation methods. The better calculated RFs with the spline method lead to improved H - K analysis and improved determination of the optimal Moho …

One Pot Synthesis Of Metal, Carbides And Polymeric Aerogels, Naveen K. Chandrasekaran

Doctoral Dissertations

"Ultra-low density, three-dimensional assemblies of nanoparticles are referred to as aerogels, and typically are derived from supercritical fluid (SCF) drying of wet-gels. Aerogels are generally fragile materials, but that issue has been addressed successfully by X-aerogels, in which the inorganic nanoparticle framework plays the role of the template for the accumulation of polymer that connects covalently and crosslinks the nanoparticles. The resulting materials can be 300x stronger than the native network, for a nominal increase in density by a factor of 3x. Since the exceptional mechanical properties of X-aerogels are traced to the conformal polymer coating, it was reasonable to …

Minimal And Near Minimal Congruence Lattice Representations Of Finite Lattices By Finite Algebras On Sets Of Integers, Roger Lee Bunn

Doctoral Dissertations

"We give finite congruence lattice representations of some finite distributive, modular and nonmodular lattices by means of finite algebras on sets of integers. These representations are minimal or near minimal as determined by ρ, a mapping from the class R of finitely representable lattices into the natural numbers N"--Abstract, page iii.

Apparent Weekly And Daily Earthquake Periodicities In The Western United States, And Evolution Of Wadi Kubbania In Egypt, Ali Hadi Atef

Doctoral Dissertations

"The dissertation consists of two separate sections. The first section is on apparent daily and weekly periodicities in earthquake occurrence in the western United State [sic]. Analysis of Apparent Seismicity Rate (ASR) in the western United States confirmed the existence of prominent spectral peaks with a period of 1 and 7 days. The number of recorded earthquakes on Sundays for the duration of 1963-2008 is about 5% higher than that on weekdays, and, more significantly, there is a 9% increase of ASR in the early morning compared with that in the middle of the days. Significant similarities between the spatial …

Preliminary Model Development Of Metal Complexation Of Polyester Derivatives Of 2,2'-Biimidazole, Shelonda Rena Taylor Finch

Doctoral Dissertations

"The objective of this study was to develop a chemical model for metal ion complex formation by a macroligand system with multi-metal binding sites using 2,2'-biimidazole as the starting molecule of the ligand system. Prior studies in this laboratory guided the selection of diesters and hydroxyethyl derivatives of 2,2'-biimidazole as model monomers. In addition, metal ion complexation studies with 2,2'-biimidazole derivatives were conducted. As a result, crystal structures of 1,1'-di(methylpropionato)-2,2-biimidazole, 2,2'-bis(1H-imidazolium) dinitrate and silver 2,2'-bis(1H-imidazolium) trinitrate, were reported. The crystal structures indicated a dependence upon the binding ability of the protonated 2,2'-biimidazole and counter ions. transesterification of the diesters and …

Quantum Phase Transitions In The Presence Of Disorder And Dissipation, Chetan Kotabage

Doctoral Dissertations

"A quantum phase transition is a phase transition at absolute zero occurring under variations in an external non-thermal parameter such as magnetic field or pressure. Quantum phase transitions are one among the important topics currently investigated in condensed matter physics. They are observed in various systems, e.g., in the ferromagnetic-paramagnetic phase transition in LiHoF₄ or in the superconductor-metal phase transition in nanowires.

A particular class of quantum phase transitions, which is phase transitions in the presence of disorder and dissipation, is investigated here. An example of this class is the ferromagnetic-paramagnetic phase transition in Ni₁₋ₓVₓ or CePd_1-xRhₓ caused …

Quantum Electrodynamics And Fundamental Constants, Benedikt J. Wundt

Doctoral Dissertations

"The unprecedented precision achieved both in the experimental measurements as well as in the theoretical description of atomic bound states make them an ideal study object for fundamental physics and the determination of fundamental constants. This requires a careful study of the effects from quantum electrodynamics (QED) on the interaction between the electron and the nucleus.

The two theoretical approaches for the evaluation of QED corrections are presented and discussed. Due to the presence of two energy scales from the binding potential and the radiation field, an overlapping parameter has to be used in both the approaches in order to …

Structure-Function Relationships In Poly(3-Hexylthiophene)S Formed Via Manipulation Of Oxidative Coupling Routes, Warren James Solfiell

LSU Doctoral Dissertations

This investigation focused on the analytical characterization of poly(3-hexylthiophene), a heterocyclic conducting polymer system, with an overall objective of elucidating the effects that the experimental conditions during chemical oxidation using iron(III) chloride as an oxidant impart on the structure of the resulting polymers. Poly(3-alkylthiophene)s are extensively studied materials due to their high electrical conductivities and unique optical properties that make them extremely valuable for use in contemporary technological applications and devices. Specifically, the aim of this research was to determine the dependence of structural characteristics, such as endgroups, molecular weights, and regioregularities, on the solvent employed for the reaction and …

Analysis Of Amyloid Beta (A [Beta]) Peptides By Capillary Electrophoresis And Laser-Induced Fluorescence Anisotropy Detection, Ryan Andrew Picou

LSU Doctoral Dissertations

The goal of the research presented in this dissertation is to develop laser-induced fluorescence anisotropy (LIFA) detection for detecting and characterizing amyloid beta (Aβ) peptide aggregates separated by capillary electrophoresis (CE). Senile plaques composed primarily of aggregated Aβ (1-40) and Aβ (1-42) peptides have been found in the brains of Alzheimer’s disease patients. These peptides are thought to be responsible for the disease pathology. A CE method using UV absorbance detection was developed for the quantification of Aβ (1-40) monomer and testing of Aβ monomer preparations for undesired aggregates (Chapter 2). Analyses of both Aβ (1-40) and Aβ (1-42) monomer …

Some Classes Of Graphs That Are Nearly Cycle-Free, Lisa Warshauer

LSU Doctoral Dissertations

A graph is almost series-parallel if there is some edge that one can add to the graph and then contract out to leave a series-parallel graph, that is, a graph with no K₄-minor. In this dissertation, we find the full list of excluded minors for the class of graphs that are almost series-parallel. We also obtain the corresponding result for the class of graphs such that uncontracting an edge and then deleting the uncontracted edge produces a series-parallel graph.

A notable feature of a 3-connected almost series-parallel graph is that it has two vertices whose removal leaves a …

Marketing Forest-Based Ecotourism In Sri Lanka: Predicting The Ecotourism Behavior And Defining The Market Segment Through A Behavioral Approach, Polwattage K. Perera

LSU Doctoral Dissertations

Tourism industry is one of the main drivers of the global economy and plays a key role in regional development. As negative environmental and socio-cultural impacts of mass tourism became apparent, the appeal of alternative forms of tourism, especially ecotourism, continued to gain a broad recognition. As a result, ecotourism became one of the fastest growing sectors in global tourism during the past decade. Being a fast-developing country with ample natural resources, Sri Lanka can benefit from adopting and promoting ecotourism. At present, Sri Lanka’s ecotourism resources remain largely under-utilized. With rising demand, ecotourism operators are under pressure to meet …

A Comprehensive Study Of Dust Formation And Evolution In Core Collape Supernovae, Jennifer Erin Andrews

LSU Doctoral Dissertations

Detection of large amounts of dust in high redshift galaxies suggests that core collapse supernovae (CCSNe) may play a critical role in the dust budget of galaxies in the early universe, when galaxies are only a few hundred million years old. At an age of only 1Gyr, asymptotic giant branch (AGB) stars may not have had the time to become significant dust contributors, leaving CCSNe as an alternative explanation since they quickly evolve and return their material to the surrounding interstellar medium. For the past three years, I have been observing the CCSNe 2007it and 2007od with Gemini, Hubble Space …

Formation And Stabilization Of Combustion-Generated Environmentally Persistent Free Radicals On Transition Metal Oxides Supported On Silica, Eric Warren Pimentel Vejerano

LSU Doctoral Dissertations

The formation of environmentally persistent free radicals in combustion system was investigated from chemisorptions of chlorine- and hydroxy-substituted benzenes on transition metal oxide surface under post-combustion conditions. This manuscript reports the formation of EPFRs on silica particles containing 5% Fe(III)2O3, Ni(II)O, and Zn(II)O. The EPFRs are formed by the chemisorption of substituted aromatic molecular adsorbates on the metal cation center followed by electron transfer from the adsorbate to the metal ion at temperatures from 150 to 400 oC. Depending on the nature of the adsorbate and the temperature, two organic EPFRs were formed: a phenoxyl-type radical, which has a lower …

Microwave-Induced Bismuth Nitrate-Mediated Selective Hydrolysis Of Amide, Debasish Bandyopadhyay, Rene Solano Fonseca, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Microwave-induced selective hydrolysis of amide to the corresponding amine has been achieved with bismuth nitrate and montmorillonite KSF clay.

An Easy And Straightforward Route For The Synthesis Of Disubstituted Imidazoles, Debasish Bandyopadhyay, Yvette Mora, Jesus A. Trevino-Cantu, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

A simple and high-yielding procedure has been developed to synthesize disubstituted imidalozes using phenyl glyoxal monohydrate, ammonium acetate and aldehydes. This synthetic protocol allows the preparation of a variety of 2,4 (s)-disubstituted imidalozes without using any catalyst, expensive or sensitive reagents. A corresponding 2-aroyl-4(s) disubstituted imidalozes derivative has also been isolated as byproduct. The effects of solvents have also been studied.

Microwave-Induced Bismuth Nitrate-Catalyzed Electrophilic Substitution Of 7-Aza Indole With Activated Carbonyl Compound Under Solvent-Free Conditions, Sonya Rivera, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

An expeditious microwave-induced synthetic method for the preparation of bis(azaindollyl)methane derivative has been developed through a bismuth nitrate-catalyzed reaction of 7-azaindole with diethylketomalonate under solvent-free conditions.

Microwave-Induced N-Bromosuccinimide-Mediated Novel Synthesis Of Pyrroles Via Paal-Knorr Reaction, Rosemarie Andoh-Baidoo, Roberto Danso, Sanghamitra Mukherjee, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

An expeditious rapid synthesis of N-substituted pyrroles using microwave-induced Nbromosuccinimide- mediated solventless reaction of 2,5-hexanedione and primary amine has been accomplished.

Microwave-Induced Bismuth Nitrate-Catalyzed Electrophilic Substitution Of Indole With Keto Ester Under Slovent-Free Conditions, Sonya Rivera, Laura Iglesias, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Microwave-induced preparation of bis(indollyl)methane derivative has been developed through a bismuth nitrate-catalyzed reaction of indole with diethylketomalonate under solventfree conditions.

Microwave-Induced Indium-Catalyzed Synthesis Of Pyrrole Fused With Indoline In Water, Dina Abrego, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

An expeditious microwave-induced indium metal-catalyzed synthesis of pyrrole fused with indoline in water is developed by reacting isatin and 4-hydroxyproline.

Microwave-Induced Bismuth Nitrate-Catalyzed Expeditious Enamination Of Β-Dicarbonyl Compounds Under Solvent-Free Conditions, Debasish Bandyopadhyay, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Bismuth nitrate-catalyzed, automated microwave-assisted expeditious synthesis of β- enaminones and β-enaminoesters has been carried out in an efficient manner under solvent-free condition. The reaction is general for primary, secondary (cyclic, heterocyclic and acyclic), benzylic as well as aromatic amines.

Antimicrobial Activity Of Eugenol Derivatives, George Eyambe, Luis Canales, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The antibacterial properties of the clove plant are due to the presence of eugenol, an aromatic phenolic compound. Eugenol was isolated from clove by stem distillation. The alkene group in eugenol was epoxidized resulting in the synthesis of epoxide-eugenol. The heterocyclic ring in epoxide was cleaved to a bromoalcohol derivative. The compounds synthesized epoxideeugenol, bromo alcohol and euginol were tested for antimicrobial activity against Staphylococcus aureus (ATCC 25923). Epoxide-eugenol was found to be the most effective antimicrobial agent among the three compounds tested.

Phosphoric Acid Catalyzed Aza-Michael Reaction In Water: An Ecofriendly Procedure, Debasish Bandyopadhyay, Stephanie Maldonado, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Phosphoric acid catalyzed aza-Michael reaction in water has been carried out in an efficient manner at room temperature. The reaction is general for primary, secondary (cyclic, heterocyclic and acyclic), benzylic as well as aromatic amines. No bis-addition was observed for primary amines.

Sythesis Of Glucose Peracetate Via Bismuth Nitrate-Induced Reaction, Jose Lerma, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Simple synthesis peracetylated glucose has been achieved starting from glucose and acetic anhydride in the absence of solvent via bismuth nitrate-catalyzed reaction. This method does not need large excess of acetic anhydride.

Microwave-Induced Stereoselectivity Of Β-Lactam Formation: Effects Of Solvents, Debasish Bandyopadhyay, Marco Yanez, Bimal K. Banik

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Synthesis of 3, 4-disubstituted 2-azetidinones has been achieved following Staudinger reaction under microwave-induced conditions. The stereoselectivity of β-lactam formation depends on the nature of the solvents used in the reaction.

Capturing Elements In Matroid Minors, Deborah Chun

LSU Doctoral Dissertations

In this dissertation, we begin with an introduction to a matroid as the natural generalization of independence arising in three different fields of mathematics. In the first chapter, we develop graph theory and matroid theory terminology necessary to the topic of this dissertation. In Chapter 2 and Chapter 3, we prove two main results. A result of Ding, Oporowski, Oxley, and Vertigan reveals that a large 3-connected matroid M has unavoidable structure. For every n exceeding two, there is an integer f(n) so that if |E(M)| exceeds f(n), then M has a minor isomorphic to the rank-n wheel or whirl, …

What Is The Emperor Wearing? The Secret Lives Of Ecosystem Services, James Salzman

Faculty Scholarship

No abstract provided.

Atomistic Studies Of Shock-Wave And Detonation Phenomena In Energetic Materials, Mikalai Budzevich

USF Tampa Graduate Theses and Dissertations

The major goal of this PhD project is to investigate the fundamental properties of energetic materials, including their atomic and electronic structures, as well as mechanical properties, and relate these to the fundamental mechanisms of shock wave and detonation propagation using state-of-the-art simulation methods. The first part of this PhD project was aimed at the investigation of static properties of energetic materials (EMs) with specific focus on 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). The major goal was to calculate the isotropic and anisotropic equations of state for TATB within a range of compressions not accessible to experiment, and to make predictions of anisotropic sensitivity …

Palaeoclimatic Significance Of Perennial Ice Accumulations In Caves: An Example From Scarisoara Ice Cave, Romania, Aurel Persoiu Tiritu

USF Tampa Graduate Theses and Dissertations

Stable isotopes in ice cores drilled in the polar and high-mountain region have been used intensively to reconstruct past climatic changes and atmospheric dynamics. However, no similar studies have been conducted on perennial ice accumulations in caves due to a limited understanding of the links between the external and cave environments, and the way in which the climatic signal can be recorded by the cave ice.

In this thesis, we successfully designed and build a research methodology for the reconstruction of past climatic changes based on perennial ice accumulation in caves, using as example the Scarisoara Ice Cave, Romania. The …

Carbon Nanotubes Interactions: Theory And Applications, Adrian Popescu

USF Tampa Graduate Theses and Dissertations

A theoretical framework describing the carbon nanotubes interaction, involving two distinct approaches, is presented. Based on the results obtained practical applications using carbon nanotubes are further proposed.

First a classical approach is employed for different geometrical configurations, such as parallel or concentric carbon nanotubes. For all the cases analytical expressions for the systems potential energies are derived.

The results obtained using the classical approach are used to propose a few practical applications. These applications include a non-contact device for profiling surfaces and a custom telescopic double wall carbon nanotube for nanolithography applications. It is expected that such devices can be …