Physical Sciences and Mathematics Commons^™

Chiral Phosphoric Acid-Catalyzed Acetalization And Iso-Pictet-Spengler Reactions, Matthew Jon Kaplan

USF Tampa Graduate Theses and Dissertations

The development of novel asymmetric reaction methodologies has been invaluable in both the academic and industrial world. In just 15 years, organocatalysis has provided a new means of developing asymmetric reaction methodologies using catalysts that are environmentally benign, relatively inexpensive, bench stable, and non-toxic. One development in organocatalysis that is important to our group in particular is chiral phosphoric acid-catalysis. BINOL-derived and VAPOL-derived phosphoric acids have proven to be excellent catalysts for a number of reactions.

The two projects I will discuss my efforts on are acetalization and iso-Pictet-Spengler reactions. These were projects that I performed during my first two …

Spin Dependent Transport In Novel Magnetic Heterostructures, Priyanga Buddhika Jayathilaka

USF Tampa Graduate Theses and Dissertations

Magnetic oxides have become of interest source for spin transport devices due to their high spin polarization. But the real applications of these oxides remains unsatisfactory up to date, mostly due to the change of properties as a result of nano structuring. Magnetite (Fe₃O₄) is one such a material. High Curie temperature and the half metallicity of Fe₃O₄ make it a good potential candidate for spin transport devices. Studies have shown that the nano structuring Fe₃O₄ changes most of it's important properties. This includes high saturation magnetization and drop of …

Bayesian Estimation Of Panel Data Fractional Response Models With Endogeneity: An Application To Standardized Test Rates, Lawrence Kessler

USF Tampa Graduate Theses and Dissertations

In this paper I propose Bayesian estimation of a nonlinear panel data model with a fractional dependent variable (bounded between 0 and 1). Specifically, I estimate a panel data fractional probit model which takes into account the bounded nature of the fractional response variable. I outline estimation under the assumption of strict exogeneity as well as when allowing for potential endogeneity. Furthermore, I illustrate how transitioning from the strictly exogenous case to the case of endogeneity only requires slight adjustments. For comparative purposes I also estimate linear specifications of these models and show how quantities of interest such as marginal …

A Rheological Examination Of Polymer Composites: Including Functionalized Carbon Nanotubes, Viable Polyurethane Alternates, And Contact Lens Hydrogels, Bernard Knudsen

USF Tampa Graduate Theses and Dissertations

From medicine to aerospace, innovation in multiple fields will not occur without addressing current questions that still exist in polymer behavior and manipulation. This dissertation represents the research carried out over the course of three separate experiments using rheometry as the key technique to explore the behavior of polymer composites. In all three studies, polymer composites were investigated for changes to their known physical properties caused through the addition of a filler or functionalization.

Chapter Two examines the possibility of enhancing poly(4-methyl-1-pentene) through the use of soluble carbon nanotubes. In this series of experiments, carbon nanotubes were covalently functionalized using …

Effect Of Solids Retention Time On The Denitrification Potential Of Anaerobically Digested Swine Waste, Maureen Njoki Kinyua

USF Tampa Graduate Theses and Dissertations

Three continuously stirred tank reactors (CSTR) were operated in semi continuous mode treating swine waste using anaerobic digestion. The reactors were used to test the effect of solid retention time (SRT) on CH4 yield, total ammonia nitrogen (TAN) concentrations, % volatile solids (VS), chemical oxygen demand (COD) and volatile fatty acids (VFA) removal, readily biodegradable COD concentration and the denitrification potential for the effluent in a biological nutrient removal (BNR) system. During Phase I of the study, the three reactors were operated at the same 28 day SRT for 16 weeks. SRTs were then changed during the 12 week Phase …

Toward More Composable Software-Security Policies: Tools And Techniques, Daniel Lomsak

USF Tampa Graduate Theses and Dissertations

Complex software-security policies are dicult to specify, understand, and update. The

same is true for complex software in general, but while many tools and techniques exist

for decomposing complex general software into simpler reusable modules (packages, classes,

functions, aspects, etc.), few tools exist for decomposing complex security policies into simpler

reusable modules. The tools that do exist for modularizing policies either encapsulate

entire policies as atomic modules that cannot be decomposed or allow ne-grained policy

modularization but require expertise to use correctly.

This dissertation presents a policy-composition tool called PoliSeer [27, 26] and the

PoCo policy-composition software-security language. PoliSeer is …

Do Personality Tests Have A Place In Academic Preparation Of Undergradute Hospitality Students, Gunce Malan

USF Tampa Graduate Theses and Dissertations

This is a descriptive study that poses the questions and discussion regarding use of personality tests in prediction of future job performance of the current undergraduate hospitality students. A gap exists between the perception of the skills and competencies of high performers and the perception of hospitality students (Berezina et al., 2011; Malan, Berezina & Cobanoglu, 2012). The purpose of this study is to investigate if personality tests will help in predicting the success of students in their preferred job setting as compared to current high performers (managers).

The use of personality tests increased substantially after 1988, when the government …

Biochemical Aspects Of The Thermal Sensitivity And Energy Balance Of Polar, Tropical And Subtropical Teleosts, Eloy Martinez

USF Tampa Graduate Theses and Dissertations

The maintenance of a functional energy balance in ectothermic fauna could be challenging in a thermally disparate environment. Biochemical adaptations at the enzyme and membrane levels allows for a set compensatory mechanism that allow the individual to maintain an energetic surplus, thus allocating energy for growth and reproduction. The present work describes how the energetic machinery in the cell, particularly the mitochondrion, could be affected by temperature changes. More specifically, this work aimed to determine how environmental temperature affects the mitochondria energetic performance of fishes from disparate thermal regimes.

Mitochondrial ATP production efficiency was evaluated in fishes from polar, tropical …

Reaction Enthalpy And Volume Profiles For Excited State Reactions Involving Electron Transfer And Proton-Coupled Electron Transfer, William Antonio Maza

USF Tampa Graduate Theses and Dissertations

Electron transfer, ET, and proton-coupled electron transfer, PCET, reactions are central to biological reactions involving catalysis, energy conversion and energy storage. The movement of electrons and protons in either a sequential or concerted manner are coupled in a series of elementary reaction steps in respiration and photosynthesis to harvest and convert energy consumed in foodstuffs or by absorption of light into high energy chemi-cal bonds in the form of ATP. These electron transfer processes may be modulated by conformational dynamics within the protein matrix or at the protein-protein interface, the energetics of which are still not well understood. Photoacoustic calorimetry …

Development Of Novel Nano-Composite Membranes As Introduction Systems For Mass Spectrometers: Contrasting Nano-Composite Membranes And Conventional Inlet Systems, Luis Miranda

USF Tampa Graduate Theses and Dissertations

This dissertation presents the development of novel nano-composite membranes as introduction systems for mass spectrometers. These nano-composite membranes incorporate anodic aluminum oxide (AAO) membranes as templates that can be used by themselves or modified by a variety of chemical deposition processes. Two types of nano-composite membranes are presented. The first nano-composite membrane has carbon deposited within the pores of an AAO membrane. The second nano-composite membrane is made by coating an AAO membrane with a thin polymer film. The following chapters describe the transmission properties these nano-composite membranes and compare them to conventional mass spectrometry introduction systems. The nano- composite …

Gradients In Season, Latitude, And Sea Ice: Their Effect On Metabolism And Stable Isotopic Composition Of Antarctic Micronekton, Erica H. Ombres

USF Tampa Graduate Theses and Dissertations

Respiration, metabolic enzyme assays, and body composition parameters were measured in the Antarctic krill Euphausia superba during the summer, fall and winter on the Western Antarctic Peninsula (WAP). E. superba of all sizes decrease their metabolism from the summer to the winter. These same parameters were also measured along the WAP during the austral fall 2010. E. superba's enzyme activity indicated that there was a latitudinal gradient to the decline in metabolism along the WAP with the more northerly sites having significantly higher metabolic enzyme activities than the sites to the south.

Carbon (δ¹³C) and nitrogen (δ^{15 …}

Dynamic Processes In Network Goods: Modeling, Analysis And Applications, Arnut Paothong

USF Tampa Graduate Theses and Dissertations

The network externality function plays a very important role in the study of economic network industries. Moreover, the consumer group dynamic interactions coupled with network externality concept is going to play a dominant role in the network goods in the 21st century. The existing literature is stemmed on a choice of externality function with certain quantitative properties. The utility function coupled with the network externality function is used to investigate static properties of rational equilibrium. The aim of this work is to systematically initiate a development of quantitative effects of the concept of network externality and its influence on the …

Light-Environment Controls And Basal Resource Use Of Planktonic And Benthic Primary Production, Kara Radabaugh

USF Tampa Graduate Theses and Dissertations

Consumers in marine and estuarine environments have a strong reliance on planktonic and benthic primary production. These two basal resources form the foundation of aquatic food webs, yet the abundance of phytoplankton and benthic algae are frequently inversely related due to competition for light and nutrients. As a result, optimal habitats for benthic and planktonic consumers vary spatially and temporally. To investigate these trends, three studies were conducted focusing on light attenuation and basal resources in a bay, river, and on a continental shelf.

δ¹³C and δ¹⁵N stable isotopes can be used as endogenous tracers to …

Non-Equilibrium Melting And Sublimation Of Graphene Simulated With Two Interatomic Potentials, Brad Steele

USF Tampa Graduate Theses and Dissertations

The mechanisms of the sublimation of graphene at zero pressure and the condensation of carbon vapor is investigated by molecular dynamics (MD) simulations. The interatomic interactions are described by the Reactive Empirical Bond Order potential (REBO). It is found that graphene sublimates at a temperature of 5,200 K. At the onset of sublimation, defects that contain several pentagons and heptagons are formed, that are shown to evolve from double vacancies and stone wales defects. These defects consisting of pentagons and heptagons act as nucleation sites for the gaseous phase. The influence of the interatomic interactions on the sublimation process are …

Synthesis And Properties Of Polymer Nanocomposites With Tunable Electromagnetic Response, Kristen Lee Stojak

USF Tampa Graduate Theses and Dissertations

Multifunctional polymer nanocomposites (PNCs) are attractive for the design of tunable RF and microwave components such as flexible electronics, attenuators, and antennas due to cost-effectiveness and durability of polymeric matrices. In this work, three separate PNCs were synthesized. Magnetite (Fe3O4) and cobalt ferrite (CFO) nanoparticles, synthesized by thermal decomposition, were used as PNC fillers. Polymers used in this work were a commercial polymer provided by the Rogers Corporation (RP) and polyvinylidene fluoride (PVDF). PNCs in this thesis consist of Fe3O4 in RP, CFO in RP, and Fe3O4 in PVDF. Characterization techniques for determining morphology of the nanoparticles, and their resulting …

Flexible Urban Water Distribution Systems, Seneshaw Amare Tsegaye

USF Tampa Graduate Theses and Dissertations

With increasing global change pressures such as urbanization and climate change, cities of the future will experience difficulties in efficiently managing scarcer and less reliable water resources. However, projections of future global change pressures are plagued with uncertainties. This increases the difficulty in developing urban water systems that are adaptable to future uncertainty.

A major component of an urban water system is the distribution system, which constitutes approximately 80-85% of the total cost of the water supply system (Swamee and Sharma, 2008). Traditionally, water distribution systems (WDS) are designed using deterministic assumptions of main model input variables such as water …

Boolean Partition Algebras, Joseph Anthony Van Name

USF Tampa Graduate Theses and Dissertations

A Boolean partition algebra is a pair $(B,F)$ where $B$ is a Boolean

algebra and $F$ is a filter on the semilattice of partitions of $B$ where $\bigcup F=B\setminus\{0\}$. In this dissertation, we shall investigate the algebraic theory of Boolean partition algebras and their connection with uniform spaces. In particular, we shall show that the category of complete non-Archimedean uniform spaces

is equivalent to a subcategory of the category of Boolean partition algebras, and notions such as supercompleteness

of non-Archimedean uniform spaces can be formulated in terms of Boolean partition algebras.

Computational Approaches For Structure Based Drug Design And Protein Structure-Function Prediction, Sai Lakshmana Kumar Vankayala

USF Tampa Graduate Theses and Dissertations

This dissertation thesis consists of a series of chapters that are interwoven by solving interesting biological problems, employing various computational methodologies. These techniques provide meaningful physical insights to promote the scientific fields of interest. Focus of chapter 1 concerns, the importance of computational tools like docking studies in advancing structure based drug design processes. This chapter also addresses the prime concerns like scoring functions, sampling algorithms and flexible docking studies that hamper the docking successes. Information about the different kinds of flexible dockings in terms of accuracy, time limitations and success studies are presented. Later the importance of Induced fit …

Assessing Hurricane Preparedness Among Residential Staff At Louisiana State University: A Case Study On Hurricane Isaac, Ashley Marie Weatherall

USF Tampa Graduate Theses and Dissertations

Studying hurricane preparedness among the Resident Assistants (RAs) and Residence Life Coordinators (RLCs) at Louisiana State University (LSU) is imperative to assure that the university housing staff is fully equipped when faced with an oncoming threat. This study seeks to fill a gap in research by investigating the influences of preparedness on student housing employees. A survey was developed and the measures were found to be coherent and internally reliable through the use of factor analysis. Based on theory and previous literature, a linear regression model was developed that quantified the relationship between the independent variable of preparedness and general …

Statistical Topics Applied To Pressure And Temperature Readings In The Gulf Of Mexico, Malena Kathleen Allison

USF Tampa Graduate Theses and Dissertations

The field of statistical research in weather allows for the application of old and new methods, some of which may describe relationships between certain variables better such as temperatures and pressure. The objective of this study was to apply a variety of traditional and novel statistical methods to analyze data from the National Data Buoy Center, which records among other variables barometric pressure, atmospheric temperature, water temperature and dew point temperature. The analysis included attempts to better describe and model the data as well as to make estimations for certain variables. The following statistical methods were utilized: linear regression, non-response …

Effectiveness Of Propensity Score Methods In A Multilevel Framework: A Monte Carlo Study, Aarti P. Bellara

USF Tampa Graduate Theses and Dissertations

Propensity score analysis has been used to minimize the selection bias in observational studies to identify causal relationships. A propensity score is an estimate of an individual's probability of being placed in a treatment group given a set of covariates. Propensity score analysis aims to use the estimate to create balanced groups, akin to a randomized experiment. This study used Monte Carlo methods to examine the appropriateness of using propensity score methods to achieve balance between groups on observed covariates and reproduce treatment effect estimates in multilevel studies. Specifically, this study examined the extent to which four different propensity score …

Model Pt- And Pd-Based Electrocatalysts For Low Temperature Fuel Cells Applications, Selasi Ofoe Blavo

USF Tampa Graduate Theses and Dissertations

In the search for alternative energy technologies, low temperature fuel cells continue to feature as technologies with the most promise for mass commercialization. Among the low temperature fuel cells, alkaline and proton exchange membrane fuel cells are the most popular. Alkaline fuel cells have typically been used for water generation as well as auxiliary power for space shuttles. Their bulkiness however makes them undesirable for other applications, especially in automobiles, where there is a great demand for alternative technologies to internal combustion engines. Proton exchange membrane fuel cells on the other hand possess numerous qualities including their compact size, high …

Net Effects Of Batrachochytrium Dendrobatidis (Bd) And Fungicides On Anurans Across Life Stages, Jenise Brown

USF Tampa Graduate Theses and Dissertations

Amphibians are declining at alarming rates globally. Multiple factors contribute to these declines, including chemical contaminants and emergent diseases. In recent years, agrochemical use, especially fungicide applications, has increased considerably. Previous studies have demonstrated that these agrochemicals leave application sites and enter wetlands via runoff and have detrimental effects on non-target organisms. For example, exposure to contaminants can have multifarious effects on amphibians, such as reducing their ability to deal with a secondary stressor, such as disease.

A pathogen that is found concomitant with chemical contaminants in aquatic systems is Batrachochytrium dendrobatidis (Bd). Bd has decimated amphibian populations worldwide. Susceptibility …

Development Of Improved Models For Gas Sorption Simulation, Keith Mclaughlin

USF Tampa Graduate Theses and Dissertations

Computational chemistry offers one the ability to develop a better understanding of the complex physical and chemical interactions that are fundamental to macro- and mesoscopic processes that are seen in laboratory experiments, industrial processes, and ordinary, everyday life. For many systems, the physics of interest occur at the molecular or atomistic levels, and in these cases, computational modeling and two well refined simulation techniques become invaluable: Monte Carlo (MC) and molecular dynamics (MD). In this work, two well established problems were tackled. First, models and potentials for various gas molecules were produced and refined from first principles. These models, although …

Understanding Transport Variability Of The Antarctic Circumpolar Current Using Ocean Bottom Pressure, Jessica Makowski

USF Tampa Graduate Theses and Dissertations

Previous studies have suggested that ocean bottom pressure (OBP) can be used to measure the transport variability of the Antarctic Circumpolar Current (ACC). The OBP observations from the Gravity Recovery and Climate Experiment (GRACE) are used to calculate transport along the choke point between Antarctica and Australia. Statistical analysis will be conducted to determine the uncertainty of the GRACE observations using a simulated data set.

There has been some evidence to suggest that Southern Hemisphere winds and the Southern Annular Mode (SAM) or the Antarctic Oscillation (AAO) play a significant role in accelerating/decelerating ACC transport, along with some contribution from …

Evaluating Habitat Vulnerability And Sustainability Of Urban Seagrass Resources To Sea Level Rise, Cynthia A. Meyer

USF Tampa Graduate Theses and Dissertations

The seagrass resource provides essential ecosystem functions for many marine species. This research evaluated the vulnerability and sustainability of the seagrass resource in an urbanized area to the effects of sea level rise. The assessment required analysis of information regarding the biogeography of the seagrass resource, and developing a method to model the spatial extent of the suitable habitat for seagrass, and applying the model to predict the implications of simulated sea level rise scenarios on the seagrass resource.

Examining the biogeography of the seagrass resource required the development of a seagrass monitoring and assessment field survey and a comprehensive …

Human Intention Recognition Based Assisted Telerobotic Grasping Of Objects In An Unstructured Environment, Karan Hariharan Khokar

USF Tampa Graduate Theses and Dissertations

In this dissertation work, a methodology is proposed to enable a robot to identify an object to be grasped and its intended grasp configuration while a human is teleoperating a robot towards the desired object. Based on the detected object and grasp configuration, the human is assisted in the teleoperation task. The environment is unstructured and consists of a number of objects, each with various possible grasp configurations. The identification of the object and the grasp configuration is carried out in real time, by recognizing the intention of the human motion. Simultaneously, the human user is assisted to preshape over …

Hypogene Speleogenesis In The Cerna River Basin, Sw Romania: A Sedimentological, Mineralogical, And Stable Isotopic Approach, Cristina Montana Puscas

USF Tampa Graduate Theses and Dissertations

Ever since it was identified as a speleogenetic process in the Guadalupe Mountains of New Mexico, USA, hypogene speleogenesis has become the focus of numerous research projects aimed at discerning between classical epigene caves and sulfuric acid or thermal caves. The first distinguishing characteristics that were recognized for hypogene caves were passage and cave morphology. The following step was the identification of rare minerals, specific for processes associated to hypogene speleogenesis. One other important step was the recognition of the importance of stable isotopes - mainly of S - in tracing the source of S and the chemical processes affecting …

Unusual Patterns Of Seismicity During Eruptive And Non-Eruptive Periods At The Persistently Restless Telica Volcano, Nicaragua, Melanie Rodgers

USF Tampa Graduate Theses and Dissertations

Telica Volcano, Nicaragua, is a persistently restless volcano with high rates of seismicity that can vary from less than ten events to over a thousand events per day. Low-frequency (LF) events dominate the seismic catalogue and seismicity rates at Telica show little clear correlation with periods of eruption. As such, traditional methods of forecasting of volcanic activity based on increases in seismicity and recognition of LF activity are not applicable. A single seismic station has been operating at Telica since 1993, and in 2010 we installed a broadband seismic and continuous GPS network (TESAND network) at Telica. In this study …

Relative Survival Of Gags Mycteroperca Microlepis Released Within A Recreational Hook-And-Line Fishery: Application Of The Cox Regression Model To Control For Heterogeneity In A Large-Scale Mark-Recapture Study, Beverly J. Sauls

USF Tampa Graduate Theses and Dissertations

The objectives of this study were to measure injuries and impairments directly observed from gags Mycteroperca microlepis caught and released within a large-scale recreational fishery, develop methods that may be used to rapidly assess the condition of reef fish discards, and estimate the total portion of discards in the fishery that suffer latent mortality. Fishery observers were placed on for-hire charter and headboat vessels operating in the Gulf of Mexico from June 2009 through December 2012 to directly observe reef fishes as they were caught by recreational anglers fishing with hook-and-line gear. Fish that were not retained by anglers were …