Physical Sciences and Mathematics Commons^™

The Stereochemistry Of Selected Supramolecular Complexes Of Cucurbiturils And The Effect Of Homogeneous Equilibria And Electron Transfer Of The Guest, Arumugam Thangavel

Doctoral Dissertations

"From a practical perspective, host-guest complexes are vehicles for understanding and using supramolecular interactions for purposeful function in sensors, molecular machines and switches, while from a fundamental perspective they may lead to novel supramolecular protection schemes in basic organic reactions. This dissertation examines the interactions of cucurbiturils as barrel-shaped hosts, exhibiting a hydrophobic cavity, with substituted benzoylpyrydinium, phenypyrylium, and diazaanthraquinonediium cations as guests. In water, N-methyl-4-(p-substituted benzoyl)pyridinium cations exist in equilibrium with their hydrated forms (gem-diols), whose concentrations depend on the para substituent. In the presence of cucurbit7uril (CB[7]), the benzoyl group shows a preference for the CB[7] cavity, and …

A Study Of The Growth And Structure Of Chromium And Iron Oxide Films On Pd(001) Using X-Ray Photoelectron Diffraction And Low Energy Electron Diffraction, Tina Dhekial-Phukan

Doctoral Dissertations

"In this study, attempts were made to grow well-ordered chromium- and iron-oxide films on a Pd(001) surface, and two sample preparation techniques, the multilayer and the sequential growth techniques, were used to grow these transition metal oxide films. The study is a part of a larger project that aims to look into the interaction between metal substrates and the overlayers grown on them. Previous studies of oxide films on Ag(001) resulted in the growth of 4-fold and 3-fold symmetry oxide structures from the multilayer and sequential growth techniques respectively. The present investigation's goal was to study how the growth of …

Adsorption And Segmental Dynamics Of Acrylate And Methacrylate Polymers Adsorbed On A Silica Surface, Piyawan Krisanangkura

Doctoral Dissertations

"Poly(isopropyl acrylate)-d₇ (PIPA- d₇) was studied using ²H solid-state NMR and modulated differential scanning calorimetry (MDSC). The polymer was deuterated on the methyl groups and side-chain methine. The PIPA- d₇ was adsorbed onto Cab-O-Sil silica. These two types of deuterons each showed their own characteristic deuterium nuclear magnetic resonance (NMR) spectra for bulk PIPA- d₇. The ²H NMR spectra of adsorbed PIPA- d₇ samples showed the presence of heterogeneity of the segmental dynamics. A residual powder pattern was found in the spectra of the surface samples at higher temperatures, indicating that the segments were tightly attached to the silica. The …

Quantum 1/F Noise In Infrared Detectors And Scanning Tunneling Microscopes, Amanda Marie Truong

Doctoral Dissertations

"Noise is, by definition, any random and persistent disturbance, which interferes with the clarity of a signal. Modern electronic devices are designed to limit noise, and in most cases the classical forms of noise have been eliminated or greatly reduced through careful design. However, there is a fundamental, quite unavoidable type of noise, called quantum 1/f noise, which occurs at low frequencies and is a fundamental consequence of the discrete nature of the charge carriers themselves. This quantum 1/f noise is present in any physical cross section or process rate, such as carrier mobility, diffusion rates and scattering processes. Although …

A Study Of Synchronization Of Nonlinear Oscillators: Application To Epileptic Seizures, Daisuke Takeshita

Doctoral Dissertations

"This dissertation focuses on several problems in neuroscience from the perspective of nonlinear dynamics and stochastic processes. The first part concerns a method to visualize the idea of the power spectrum of spike trains, which has an educational value to introductory students in biophysics. The next part consists of experimental and computational work on drug-induced epileptic seizures in the rat neocortex. In the experimental part, spatiotemporal patterns of electrical activities in the rat neocortex are measured using voltage-sensitive dye imaging. Epileptic regions show well-synchronized, in-phase activity during epileptic seizures. In the computational part, a network of a Hodgkin-Huxley type neocortical …

Nmr Investigations Of Biomass-To-Fuel Conversions By Hydrothermal Processes, Wenjia Zhang

Doctoral Dissertations

"Biofuels have gained significant attention as the most promising alternative energy and fuel supply for the near future because of two dominant reasons: first, biofuels are environmentally friendly; and second, they afford a sustainable technology. Biofuels can be synthesized from biomass by several different processes, among which, hydrothermal conversion is considered to be more energy efficient. However, scientific efforts to improve hydrothermal biomass-to-fuel (HT-BTF) conversion efficiencies are severely limited because little is known about the salient reaction mechanisms and intermediates. This study is aimed at a better understanding of the hydrothermal biomass degradation kinetics by advanced NMR spectroscopy and, accordingly, …

Investigating The Source Of Thermal Anomalies In The Northern United Arab Emirates (Uae) Desert Using Geophysical Methods, Khalid Ahmad

Doctoral Dissertations

"We conducted geophysical surveys to investigate the source of thermal anomalies and to delineate any potential water transport pathways from the recharge zones in the Oman Mountains to the location of the temporal thermal anomalies within the desert plain of the United Arab Emirates (UAE). In the visible region of the spectrum of both ASTER and MODIS satellite images, the desert plain of the UAE appears as a bare sandy surface. However, detailed examination of these images in the thermal bands reveal cooler thermal anomalies within the desert plain following major rainfall events. This anomaly has a cooler surface of …

Effect Of Structure And Plasticizer On The Glass Transition Of Adsorbed Polymer, Boonta Hetayothin

Doctoral Dissertations

"The effect of molecular mass on adsorbed poly(methyl methacrylate) (PMMA) on silica was determined using temperature-modulated differential scanning calorimetry (TMDSC). A two-component model, based on loosely-bound polymer (glass transition temperature, T_g, similar to that of bulk) and tightly-bound polymer (T_g higher than that of bulk) was used to interpret the thermograms. Similar amounts of tightly-bound polymer were found for 450 and 85 kDa PMMA (0.78 mg/m²), while the 32 kDa sample had a smaller amount (0.48mg/m²). A comparison of adsorbed PMMA, poly(vinyl acetate) (PVAc), and poly(methyl acrylate) (PMA) on silica was made using the same technique. The …

Theoretical Study Of Electron Impact-Ionization Of Molecules, Ola Al-Hagan

Doctoral Dissertations

"There has been impressive progress in the area of theoretical treatments of electron impact ionization (e,2e) of atoms and molecules in the last decade. Most recently, low to intermediate incident electron energies have been reported for molecular systems. In this dissertation, different theoretical models will be used to calculate the fully differential cross section (FDCS) for (e,2e) processes for low to intermediate incident electron energies for a variety of final state electron angles and energies for the diatomic molecules H₂ and N₂, the triatomic molecule H₂O, and the biomolecule HCOOH.

In addition, there has been a large amount of interest …

Computational Methods For The Discovery And Analysis Of Genes And Other Functional Dna Sequences, Cyriac Kandoth

Doctoral Dissertations

"The need for automating genome analysis is a result of the tremendous amount of genomic data. As of today, a high-throughput DNA sequencing machine can run millions of sequencing reactions in parallel, and it is becoming faster and cheaper to sequence the entire genome of an organism. Public databases containing genomic data are growing exponentially, and hence the rise in demand for intuitive automated methods of DNA analysis and subsequent gene identification. However, the complexity of gene organization makes automation a challenging task, and smart algorithm design and parallelization are necessary to perform accurate analyses in reasonable amounts of time. …

Protein Secondary Structure Prediction Using Blast And Relaxed Threshold Rule Induction From Coverings, Leong Lee

Doctoral Dissertations

"Protein structure prediction has always been an important research area in bioinformatics and biochemistry. Despite the recent breakthrough of combining multiple sequence alignment information and artificial intelligence algorithms to predict protein secondary structure, the Q₃ accuracy of various computational prediction methods rarely has exceeded 75%; this status has changed little since 2003 when Rost stated that "the currently best methods reach a level around 77% three-state per-residue accuracy." The application of artificial neural network methods to this problem is revolutionary in the sense that those techniques employ the homologues of proteins for training and prediction. In this dissertation, a different …

Gamma Ray Burst Redshift Catalog And Applications, Limin Xiao

LSU Doctoral Dissertations

The measurement of redshifts for gamma-ray bursts (GRBs) is an important issue for the study of the high redshift universe and cosmology. We developed a program to estimate the redshifts for GRBs from the original light curves and spectra, aiming to get redshifts for bursts without spectroscopic or photometric redshifts. We derive the luminosity indicators from the light curves and spectra of each burst, including the lag time between low and high photon energy light curves, the variability of the light curve, the peak energy of the spectrum, the number of peaks in the light curve, and the minimum rise …

Non-Axisymmetric Instabilities In Self-Gravitating Tori Around Black Holes, And Solving Einstein Constraints With Superconvergent Finite Element Methods, Oleg Korobkin

LSU Doctoral Dissertations

This thesis contains results on two related projects. In the first project, we explore non-axisymmetric instabilities in general relativistic accretion disks around black holes. Such disks are created as transient structures in several astrophysical scenarios, including mergers of compact objects and core collapse of massive stars. These disks are suggested for the role of cenral engines of gamma-ray bursts. We address the stability of these objects against the runaway and non-axisymmetric instabilities in the three-dimensional hydrodynamical fully general relativistic treatment. We explore three slender and moderately slender disk models with varying disk-to-black hole mass ratio. None of the models that …

Anatomy Of A Regional Conflict: Tarija And Resource Grievances In Moraless Bolivia, Denise Bebbington, Anthony J. Bebbington

Geography

In 2008, the Department of Tarija became the epicenter of national political struggles over political autonomy for lowland regions at odds with the Morales administration. In September, following a series of regional referenda on autonomy and a national recall election, citizen committees in Tarija mobilized urban-based sectors and organized a general strike against the central government. It is unhelpful to understand the strike as simply an act of political sabotage orchestrated by racist regional elites. The factors driving protest and interest in autonomy are varied and deeply related to patterns of hydrocarbons extraction in the department that have allowed for …

Part I: Syntheses, Characterizations, And Investigations Of Molecular Micelles And Imidazolium-Based Ionic Liquids For Protein Separations In Electrophoresis Part Ii: Investigating The Mentoring Canon Through Exploration Of Thirty Years Of Mentoring By An Exemplar, Monica R. Sylvain

LSU Doctoral Dissertations

The research reported in this dissertation is presented in two parts. The first part is the Syntheses, Characterizations, and Investigations of Molecular Micelles and Imidazolium-Based Ionic Liquids for Protein Separations in Electrophoresis, and the second part is a case study entitled Investigating the Mentoring Canon through Exploration of Thirty Years of Mentoring by an Exemplar. Protein separations in the gel electrophoretic format are ubiquitous analyses used on a daily basis throughout biochemistry, analytical chemistry, and biotechnology. The goal of the research reported in the first part of this dissertation is to synthesize and characterize molecular micelles and ether-functionalized imidazolium-based ionic …

Dissolution Of Chitosan In Ionic Liquids For Acylation Chemistry And Formation Of Cellulose-Chitosan Blends, Cristina Stefanescu

LSU Doctoral Dissertations

Dissolution of chitosan in ionic liquids was accomplished. It has been shown that 1-butyl-3-methylimidazolium acetate (BMIMAc) is a better solvent than 1-butyl-3-methylimidazolium chloride (BMIMCl). Dissolution of chitosan in BMIMCl required a prior regeneration of chitosan from 1% acetic acid solution. In the case of BMIMAc, both dried chitosan and regenerated chitosan from acetic acid solution have been dissolved in a relatively short amount of time. While concentrations up to 2 wt% of chitosan in BMIMCl could be obtained, concentrations of 10 wt % of chitosan in BMIMAc were realized. Homogeneous phthalation and benzoylation of chitosan were achieved in these ionic …

Computer Simulation Of Ion-Induced Nucleation In The Presence Of Single Ions And Ion Pairs, Samuel Keasler

LSU Doctoral Dissertations

Atmospheric aerosol particles play an important role in climate and human health. Despite their importance, the mechanisms of their formation are still poorly understood. Ion-induced nucleation may play a role in the process, but details are lacking about how the nucleation rate depends on the size, charge, and number of ions in the cluster. In order to better understand the role that ions might play in new particle formation, we have performed a series of AVUS-HR simulations of the water nucleation in the presence of both single ions and ion pairs. These simulations have shown that the location of the …

Searches For Gravitational Waves From Known Pulsars With Science Run 5 Ligo Data, B. P. Abbott, R. Abbott, F. Acernese, R. Adhikari, P. Ajith, B. Allen, G. Allen, M. Alshourbagy, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, S. Aoudia, M. A. Arain, M. Araya, H. Armandula, P. Armor, K. G. Arun, Y. Aso, S. Aston, P. Astone, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, C. Barker, D. Barker, F. Barone, B. Barr, Tiffany Z. Summerscales

Faculty Publications

We present a search for gravitational waves from 116 known millisecond and young pulsars using data from the fifth science run of the LIGO detectors. For this search, ephemerides overlapping the run period were obtained for all pulsars using radio and X-ray observations. We demonstrate an updated search method that allows for small uncertainties in the pulsar phase parameters to be included in the search. We report no signal detection from any of the targets and therefore interpret our results as upper limits on the gravitational wave signal strength. The most interesting limits are those for young pulsars. We present …

The Transition Zone: Impact Of Riverbanks On Emergent Dragonfly Nymphs. Implications For Riverbank Restoration And Management, Kirsten Hope Martin

Antioch University Dissertations & Theses

The use of riprap in the restoration and stabilization of riverine landscapes is an issue of concern for many ecologists. While current methods of bank stabilization, especially those involving the placement of rocks (riprap) along the waterline, are effective in controlling erosion their presence changes habitat components (slope, substrate composition, near-shore river velocity) at the river-land interface. The additional impacts of river current, water temperature, soil composition, slope, and water level fluctuation, may further imperil emerging nymphs. The purpose of this research is to document the effects of riprap, location (upriver or downriver of hydroelectric intake/outtake facilities), water level fluctuation, …

Differences In The Mechanism Of Collagen Lattice Contraction By Myofibroblasts And Smooth Muscle Cells, J. C. Dallon, H P. Ehrlich

Faculty Publications

Both rat derived vascular smooth muscle cells (SMC) and human myofibroblasts contain $\alpha$ smooth muscle actin (SMA), but they utilize different mechanisms to contract populated collagen lattices (PCLs). The difference is in how the cells generate the force that contracts the lattices. Human dermal fibroblasts transform into myofibroblasts, expressing $\alpha$-SMA within stress fibers, when cultured in lattices that remain attached to the surface of a tissue culture dish. When attached lattices are populated with rat derived vascular SMC, the cells retain their vascular SMC phenotype. Comparing the contraction of attached PCLs when they are released from the culture dish on …

The Longitude Problem From The 1700s To Today: An International And General Education Physics Course, Thomas J. Bensky

Physics

For instructors wishing to use physics as part of an international or general education course, the framework for a course based on the “longitude problem” from the 1700s is described. The longitude problem is teeming with basic principles of physics and astronomy, which makes it ideal for a non-science-major-based college-level course. This paper summarizes the longitude problem in the context of conceptual physics and astronomy and outlines an appropriate curriculum. Specifics on teaching such a course in London, as part of an international studies program, are discussed.

Assessing The Feasibility Of An Aerotropolis Around Cleveland Hopkins International Airport, Executive Report, Claudette Robey, Daila Shimek, James Wyles, Brian A. Mikelbank, Jim Robey, Kevin O'Brien, Et.Al.

All Maxine Goodman Levin School of Urban Affairs Publications

This report provides an assessment of the feasibility of developing an aerotropolis around Cleveland Hopkins International Airport, Cleveland, Ohio. The report describes the methodology used to assess the feasibility, notes the needs and expectations of community stakeholders, profiles the challenges and successes of six emerging and potential U.S. aerotropolises, and discusses the operating experiences and challenges of 12 additional U.S. airports. Further, this report describes the demographic and economic aspects of the study cities, and discusses potential target industry opportunities. The findings suggest that it is feasible to develop CLE as an aerotropolis, and that CLE may not be suited …

On Self-Clique Graphs., Ong Poh Hwa

Student Works (2010-2019)

The clique graph of a graph G is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques have non-empty intersection. A graph G is self-clique if it is isomorphic to its clique graph. Clique graphs have been studied for some time. However, not much is known about self-clique graphs. Self-clique graphs were ¯rst introduced and studied by Escalante [Abh. Math. Sem. Univ. Hamburg 39 (1973) 59-68]. Since then, self-clique graphs have been characterized for some classes of graphs. Chia [Discrete Math. 212 (2000) 185-189] gave a …

Laguerre Arc Length From Distance Functions, David E. Barrett, Michael Bolt

University Faculty Publications and Creative Works

For the Laguerre geometry in the dual plane, invariant arc length is shown to arise naturally through the use of a pair of distance functions. These distances are useful for identifying equivalence classes of curves, within which the extremal curves are proved to be strict maximizers of Laguerre arc length among three-times differentiable curves of constant signature in a prescribed isotopy class. For smoother curves, it is shown that Laguerre curvature determines the distortion of the distance functions. These results extend existing work for the Möbius geometry in the complex plane. © 2010 International Press.

Causes Of Tropical Atlantic Paleo-Salinity Variation During Periods Of Reduced Amoc, Xiuquan Wan, Ping Chang, Matthew W. Schmidt

OES Faculty Publications

During periods of reduced Atlantic meridional overturning circulation (AMOC) associated with a freshening of northern North Atlantic surface water, paleo proxy records indicate a corresponding surface salinity increase over the entire tropical Atlantic. Although latitudinal-shifts in the mean position of the Atlantic Intertropical Convergence Zone (ITCZ) can explain certain features of the paleo salinity reconstructions, this mechanism does not offer an explanation for the reconstructed basin-wide paleo-salinity response to AMOC change. Here, we present new results from general circulation model simulations that suggest the sea surface salinity (SSS) increase in the tropical north Atlantic during periods of weakened AMOC is …

Iron (Iii) Oxide And Copper (Ii) Oxide Mediated Formation Of Pcdd/Fs From Thermal Degradation Of 2-Mcp And 1,2-Dcbz, Shadrack Kirwa Nganai

LSU Doctoral Dissertations

Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) which occurs inexorably from most thermal and combustion processes constitutes a major toxic component of environmental pollutants. Generally, it is well established that transition metal-mediated reactions account for the majority of PCDD/F emissions from combustion sources. Specifically, both copper and iron ions, which occur abundantly in combustion generated particulate matter, are considered probably the most active in promoting PCDD/F formation typically in the low temperature post-combustion zone and flue gas pollution control devices. It has also been demonstrated that chlorinated phenols are key intermediates in essentially all pathways of PCDD/F formation. Chlorinated benzenes …

Cross-Talk-Free Dual-Color Fluorescence Cross-Correlation Spectroscopy For High-Throughtput Screening, Wonbae Lee

LSU Doctoral Dissertations

High throughput processing of chemical/biochemical information is critical in many areas, such as genome sequencing, drug discovery and clinical diagnostics. Integral to collecting information at high rates with the necessary throughput is the development of systems that can not only monitor the results with high precision and accuracy, but also prepare and process samples prior to the analytical measurement. To achieve the required throughput, we have conducted work directed toward developing a system that provides detection sensitivity at the single-molecule detection (SMD) level. The research was first focused on the development of a sensitive strategy for the detection of proteins …

Ferromagnetism And Transport In Diluted Magnetic Semiconductors, Abdolmadjid Nili

LSU Doctoral Dissertations

This dissertation focuses on the study of ferromagnetism in Dilute Magnetic Semiconductors. To study these strongly correlated electronic systems, two non- perturbative techniques are used: the Dynamical Mean Field Approximation (DMFA) and the Dynamical Cluster Approximation (DCA). The model used for Dilute Magnetic Semiconductors (DMS) incorporates the strong spin-orbit couplings of the carrier holes as found in most III-V semiconductors doped with manganese such as Ga_1-xMn_xAs. Calculated within the DMFA, the spin-orbit coupling effects give rise to various interesting physics, primarily the anisotropic behavior of the impurity band that affect the charge transport properties in the …

Upland Nesting Waterfowl Population Responses To Predator Reduction In North Dakota, Matthew R. Pieron

LSU Doctoral Dissertations

Population growth for mallards (Anas platyrhynchos), and presumably other upland nesting ducks, in the Prairie Pothole Region is most sensitive to nest success, and nest success is most strongly influenced by predation. I evaluated the efficacy of reducing predator populations to improve nest success and increase local breeding populations of upland nesting ducks on township-sized (93.2 km2) management units in eastern North Dakota, USA, during 2005−2008. I also examined potential territorial limitations on local population growth for mallards. Trappers annually removed an average of 245 predators per trapped site. I monitored 7,489 nests on 7 trapped and 5 nontrapped sites, …

Magnetocaloric Effect In Thin Films And Heterostructures, Christopher Bauer

USF Tampa Graduate Theses and Dissertations

The goals of this work are the optimization of the magnetocaloric effect in Gadolinium thin film structures. We approach this issue from two directions, that of process optimization and of interface effects. Past results showed Gd₂O₃ in our Gadolinium thin films, and the presence of such oxide seemed to grow with the temperature at which the film was grown or annealed. Comparison of samples grown without chamber gettering to those that were gettered show differences in their structural and magnetic properties, and we conclude that gettering is an effective step in enhancing the quality of Gd thin …