Physical Sciences and Mathematics Commons^™

Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett

USF Tampa Graduate Theses and Dissertations

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective.

These hypotheses …

Storm Induced Beach Profile Changes Along The Coast Of Treasure Island, West-Central Florida, U.S.A., Zhaoxu Zhu

USF Tampa Graduate Theses and Dissertations

Storms play a significant role in beach morphodynamics. Storm-induced beach-profile changes and their longshore variations are investigated in this study. The impacts of four summer tropical storms and two series of winter storms over the last 10 years along the coast of Treasure Island were documented. Tropical storms Alberto in 2006, Fay in 2008, Debby in 2012, Hermine in 2016 and winter storms in winter seasons of 2014 and 2015 are discussed in this study. In general, the Treasure Island beach experienced more erosion generated by tropical storms with greater intensity, but shorter duration, as compared to winter storms due …

Photocatalytic Reduction Of Co2 With Tunable Bandgap And Bandedge Materials, Thuhuong T. Ngo

USF Tampa Graduate Theses and Dissertations

Solar energy is a sustainable resource which has substantial potential to meet the increasing demand for renewable energy. Though there has been some success in harvesting solar energy for electricity production, converting solar energy to chemical energy as fuels is still a challenge due to low efficiency.

Since the discovery of TiO₂ photocatalysts for splitting water (4) and reducing CO₂ (5) to form useful chemical feedstock such as H₂, CO and CH₄, much research has been done to increase the efficiency of photocatalysts. However, the current conversion efficiency of photocatalysts remains low (~5%) (6, …

Reduced Dimensionality Effects In Gd-Based Magnetocaloric Materials, Hillary Faith Belliveau

USF Tampa Graduate Theses and Dissertations

Magnetic refrigeration based on the magnetocaloric effect (MCE) is a promising alternative to conventional gas compression based cooling techniques. Understanding impacts of reduced dimensionality on the magnetocaloric response of a material such as Gadolinium (Gd) or its alloys is essential in optimizing the performance of cooling devices, which is also the overall goal of this thesis. We have determined, in the first part of the thesis, that laminate structures of pure Gd produced by magnetron sputtering have several disadvantages. The target material (pure Gd), ultra-high vacuum components, and the electrical energy it takes to run the manufacturing process are all …

Improved 2d And 3d Resistivity Surveys Using Buried Electrodes And Optimized Arrays: The Multi-Electrode Resistivity Implant Technique (Merit), Henok Gidey Kiflu

USF Tampa Graduate Theses and Dissertations

This thesis presents a novel resistivity method called Multi-Electrode resistivity technique (MERIT) that is used for high resolution imaging of complex geologic features at depth and near the edges of survey lines. The MERIT electrodes are especially shaped and designed to be self-driven using a robust-direct push technique. Measurements are taken using optimized arrays that are generated using a modified version of the “Compare-R” optimization algorithm. This work focused on both two-dimensional (MERIT2D) and three-dimensional (MERIT3D) applications of the buried array and show the relevance of the additional information gained by the addition of deep electrodes especially in sites with …

Resonant Light Scattering From Semiconductor Quantum Dots, Kumarasiri Konthasinghe

USF Tampa Graduate Theses and Dissertations

In this work, resonant laser spectroscopy has been utilized in two major projects --resonance fluorescence measurements in solid-state quantum-confined nanostructures and laser-induced fluorescence measurements in gases. The first project focuses on studying resonant light-matter interactions in semiconductor quantum dots "artificial atoms" with potential applications in quantum information science. Of primary interest is the understanding of fundamental processes and how they are affected by the solid-state matrix. Unlike atoms, quantum dots are susceptible to a variety of environmental influences such as phonon scattering and spectral diffusion. These interactions alter the desired properties of the scattered light and hinder uses in certain …

Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa

USF Tampa Graduate Theses and Dissertations

Multifunctional nanocomposites are promising for a variety of applications ranging from microwave devices to biomedicine. High demand exists for magnetically tunable nanocomposite materials. My thesis focuses on synthesis and characterization of novel nanomaterials such as polymer nanocomposites (PNCs) and multi-walled carbon nanotubes (MWCNTs) with magnetic nanoparticle (NP) fillers.

Magnetite (Fe₃O₄) and cobalt ferrite (CoFe2O4) NPs with controlled shape, size, and crystallinity were successfully synthesized and used as PNC fillers in a commercial polymer provided by the Rogers Corporation and poly(vinylidene fluoride). Magnetic and microwave experiments were conducted under frequencies of 1-6 GHz in the presence of …

Towards Computational Human Behavior Modeling For Just-In-Time Adaptive Interventions, Tylar Murray

USF Tampa Graduate Theses and Dissertations

The advent of powerful wearable devices and smartphones has enabled a new generation of “in-the-wild” user studies, adaptive behavioral intervention strategies, and context measurement. Though numerous proof-of-concept studies continue to push the limitations of what a behavioral scientist can do with these technologies, there remains a major methodological roadblock separating behavioral theory and application. Avatar-user interaction theory, for example, is not well defined in its formulation, and thus guidelines for intervention designers depend on heuristic methods and designer intuition. Computational modeling has been slow to move into behavioral science in general, but a growing population of behavioral scientists recognize this …

Optimal Demand Response Models With Energy Storage Systems In Smart Grids, Mohemmed Masooud Alhaider

USF Tampa Graduate Theses and Dissertations

This research aims to develop solutions to relieve system stress conditions in electric grids. The approach adopted in this research is based on a new concept in the Smart Grid, namely, demand response optimization. A number of demand response programs with energy storage systems are designed to enable a community to achieve optimal demand side energy management.

The proposed models aim to improve the utilization of the demand side energy through load management programs including peak shaving, load shifting, and valley lling. First, a model is proposed to nd the optimal capacity of the battery energy storage system (BESS) to …

Hydrolytic And Nonhydrolytic Sol-Gel Zirconia-, Titania-, And Niobia-Based Capillary Microextraction Coatings For The Preconcentration And Hplc Analysis Of Catecholamine Neurotransmitters And Phosphorylated Peptides, Abdullah Awadh Alhendal

USF Tampa Graduate Theses and Dissertations

Sample preparation is the most error-prone step in chemical analysis. A great deal of efforts has been made to develop efficient techniques and protocols for sample preparation to accomplish important goals such as miniaturization and implementation of green analytical methodologies. Solid-phase microextraction (SPME) has successfully eliminated the use of hazardous organic solvents in extraction sampling, sample preparation, preconcentration and sample introduction to the analytical instrument in an effective manner. Ensuring thermal- and solvent-instability of traditional SPME extraction phases represented one of their main drawbacks. This was solved by the introduction of sol-gel SPME phases characterized by enhanced thermal-, solvent-, and …

Surface Properties Of Titanium Dioxide And Its Structural Modifications By Reactions With Transition Metals, Sandamali Halpegamage

USF Tampa Graduate Theses and Dissertations

Surfaces of metal oxides play a vital role in many technologically important applications. The surfaces of titanium dioxide, in particular, show quite promising properties that can be utilized in solid-state gas sensing and photocatalysis applications. In the first part of this dissertation we investigate these properties of TiO₂ surfaces through a vigorous surface scientific approach. In the second part, we investigate the possibilities of modifying the TiO₂ surfaces by depositing multi-component transition metal oxide monolayers so that the properties of bare TiO₂ surface can be influenced in a beneficial way. For instance, via formation of new surface …

Novel Magnetic Nanostructures For Enhanced Magnetic Hyperthermia Cancer Therapy, Zohreh Nemati Porshokouh

USF Tampa Graduate Theses and Dissertations

In this dissertation, I present the results of a systematic study on novel multifunctional nanostructure systems for magnetic hyperthermia applications. All the samples have been synthesized, structurally/magnetically characterized, and tested for magnetic hyperthermia treatment at the Functional Materials Laboratory of the University South Florida. This work includes studies on four different systems: (i) Core/shell Fe/γ-Fe₂O₃ nanoparticles; (ii) Spherical and cubic exchange coupled FeO/Fe₃O₄ nanoparticles; (iii) Fe₃O₄ nano-octopods with different sizes; (iv) High aspect ratio FeCo nanowires and Fe₃O₄ nanorods.

In particular, we demonstrated the enhancement of the heating …

Expansion Of The Performance Capabilities Of The Usf Inhalation Challenge Chamber, Laura Riley

USF Tampa Graduate Theses and Dissertations

The purpose of this research was to evaluate the capability and performance of the University of South Florida’s (USF) Human Exposure Chamber (HEC) using aerosols in the thoracic range. The goals of this research were two-fold: to obtain an average particle size of 10 µm (thoracic-size range) inside the chamber during dust production and to test for evenness of dust concentration within the chamber. The USF HEC can be used for studies using gases and/or particulates. The chamber measurements are 4.16 ft x 2.67 ft x 6.75 ft, for a total volume of 75 ft³ or 2.13 m^{3 …}

Miocene Contourite Deposition (Along-Slope) Near Desoto Canyon, Gulf Of Mexico: A Product Of An Enhanced Paleo-Loop Current, Shane Christopher Dunn

USF Tampa Graduate Theses and Dissertations

A Neogene contourite depositional system was identified and mapped along the DeSoto Slope in the northeastern Gulf of Mexico, U.S.A. A series of drift deposits comprising the larger contourite depositional system were interpreted from a 2-D industry seismic data set. The now subsurface drift deposits are adjacent to the anomalous seabed feature, the DeSoto Canyon, and these data suggest contourite deposition and ocean currents are in integral part of the canyon’s depositional history. The contourite depositional system is underlain by an extensive, middle Miocene aged, erosional unconformity formed by ocean currents. The timing of this erosional surface is in alignment …

Locomotion In Virtual Reality For Room Scale Tracked Areas, Evren Bozgeyikli

USF Tampa Graduate Theses and Dissertations

In the recent years, virtual reality has been used as an effective tool for a wide range of areas such as training, rehabilitation, education and games. The affordability of the new generation headsets helped this medium to become more widespread. However, in order for virtual reality to become mainstream, more content that is specifically designed for this medium is needed. Since virtual reality is a different technology than the computer systems, different design principles may be required for these content for better user experience. One of the crucial components of virtual reality applications is locomotion, since the viewpoint of the …

An Early Paleogene Palynological Assemblage From The Sabrina Coast, East Antarctica: New Species And Implications For Depositional History, Catherine Davies Smith

USF Tampa Graduate Theses and Dissertations

Palynological analyses of 13 samples from two sediment cores retrieved from the Sabrina Coast, East Antarctica, provide the first information regarding the paleovegetation within the Aurora Subglacial Basin. The assemblages, hereafter referred to as the Sabrina Flora, are dominated by angiosperms, with complexes of Gambierina (G.) rudata and G. edwardsii representing 38–66% of the assemblage and an abundant and diverse Proteaceae component. The Sabrina Flora also includes Battenipollis sectilis, Forcipites sp. and Nothofagidites spp. (mostly belonging to the N. cf. rocaensis-flemingii complex), along with a few fern spores, including Laevigatosporites ovatus, a moderate presence of conifers, and …

Virtual Reality Serious Games For Individuals With Autism Spectrum Disorder: Design Considerations, Lal Bozgeyikli

USF Tampa Graduate Theses and Dissertations

Virtual reality has been a popular training tool for individuals with Autism Spectrum Disorder (ASD) in recent years. Although virtual reality was proven to be a promising tool for individuals with ASD by many previous studies, effects of virtual reality properties on user experience is still an unexplored area. More comparison studies and reliable data are needed to identify the benefits of different VR methods and properties, and leverage the future VR systems. In this dissertation, we explored effects of virtual reality properties on user experience of high functioning individuals with ASD with four different serious game experiments. The first …

Efficiency Of An Unbalanced Design In Collecting Time To Event Data With Interval Censoring, Peiyao Cheng

USF Tampa Graduate Theses and Dissertations

In longitudinal studies, the exact timing of an event often cannot be observed, and is usually detected at a subsequent visit, which is called interval censoring. Spacing of the visits is important when designing study with interval censored data. In a typical longitudinal study, the spacing of visits is usually the same across all subjects (balanced design). In this dissertation, I propose an unbalanced design: subjects at baseline are divided into a high risk group and a low risk group based on a risk factor, and the subjects in the high risk group are followed more frequently than those in …

An Ecosystem-Based Approach To Reef Fish Management In The Gulf Of Mexico, Michelle D. Masi

USF Tampa Graduate Theses and Dissertations

Fisheries managers have the potential to significantly improve reef fish management in the Gulf of Mexico through the use of ecosystem-based approaches to fisheries management. Ecosystem-based approaches are needed to address the effects of fishing on trophodynamic interactions, to better account for ecosystem-scale processes in model projections, and to recognize the short and long-term biomass tradeoffs associated with making regulatory choices. My research was concentrated around three objectives: (1) characterizing the trophodynamic interactions between Gulf of Mexico fishes, in order to construct an invaluable tool (a Gulf of Mexico Atlantis model) to be used in ecological hypothesis testing and policy …

Development Of A Forecast Process For Meteotsunami Events In The Gulf Of Mexico, Leilani D. Paxton

USF Tampa Graduate Theses and Dissertations

The purpose of this research was to provide a better understanding of meteotsunamis over the eastern Gulf of Mexico along the west coast of Florida and to develop a process for forecasting those events. Meteotsunami waves develop from resonant effects of strong pressure perturbations greater than 1 hPa, moving in excess of 10 m s^-1, over water areas up to around 100 m in depth. Meteotsunami events over 0.3 m in height, as measured by three primary NOAA coastal tide gauges at Cedar Key, Clearwater Beach, and Naples, from 2007-2015, impact the Florida Gulf coastline several times per …

A Habitat Analysis Of Estuarine Fishes And Invertebrates, With Observations On The Effects Of Habitat-Factor Resolution, Brianna Michaud

USF Tampa Graduate Theses and Dissertations

Between 1988 and 2014, otter trawls, seine nets, and plankton nets were deployed along the salinity gradients of 18 estuaries by the University of South Florida and the Florida Fish and Wildlife Research Institute (FWRI, a research branch of the Florida Fish and Wildlife Conservation Commission). The purpose of these surveys was to document the responses of aquatic estuarine biota to variation in the quantity and quality of freshwater inflows that were being managed by the Southwest Florida Water Management District (SWFWMD).

In the present analyses, four community types collected by these gears were compared with a diversity of habitat …

Pepper Mild Mottle Virus As A Surrogate For Enteric Viruses: Implications For Assessing Water Quality, Erin Michelle Symonds

USF Tampa Graduate Theses and Dissertations

Less than 10% of the world’s domestic wastewater is disinfected prior to discharge into surface waters; therefore, human exposure to diverse wastewater-related pathogens results in millions of cases of illness each year. Among the enteric pathogens, viruses represent an important group of emerging pathogens and are frequently the cause of food- and water-borne outbreaks of illness. Although the World Health Organization and many government agencies mandate the use of bacterial indicators to identify poor microbial water quality, it is well known that these indicators poorly correlate with fecal pollution contamination events and risk of disease. The field of public health-related …

Synthesis And Characterization Of Novel Polyurethanes And Polyimides, Kenneth Kull

USF Tampa Graduate Theses and Dissertations

Four novel high performance soft thermoplastic polyurethane elastomers utilizing methylene bis(4-cyclohexylisocyanate) as a hard segment, 1,4 butanediol as a chain extender and modified low crystallinity carbonate copolymer as a soft segment were synthesized. The samples were characterized by infrared spectroscopy (FTIR), tensile, elongation, hardness, abrasion resistance and atomic force microscopy (AFM). SAXS data shows evidence of an interdomain "center-to-center" distance of 45Å. DSC traces show evidence of one glass transition temperature and a weak melting region. DMA analysis reveals a low temperature secondary relaxation and the glass to rubber transition followed by a rubbery plateau. All samples demonstrated the ability …

Evaluation Of Search And Rescue Planning Tools On The West Florida Shelf, Benjamin O'Loughlin

USF Tampa Graduate Theses and Dissertations

The Coast Guard conducts over 20,000 search and rescue cases a year with approximately 5% of them occurring within the coastal waters of the West Florida Shelf (WFS). Each search effort is planned using the Coast Guard’s Search and Rescue Optimal Planning System (SAROPS) which uses model inputs to create composite probability distributions based on the results of Monte Carlo projections of thousands of particle trajectories. However, SAROPS is limited by the quality of model inputs and their associated errors. This study utilizes observations from three surface drifter deployments on the WFS to evaluate the effectiveness of available surface current …

Baiting Sustainability: Collaborative Coastal Management, Heritage Tourism, And Alternative Fisheries In Placencia, Belize, Eric Koenig

USF Tampa Graduate Theses and Dissertations

Local coastal fishers in Belize are adapting novel strategies to manage, exploit, and market marine and coastal resources in an effort to promote fishing livelihoods and coastal environmental sustainability. These resilience strategies respond to diminished fishing stocks, fisheries and environmental policies and regulations, climate change, shifting seafood markets, and expanding tourism development. With growing foreign investment and nationally-directed infrastructure improvement projects on the Placencia Peninsula in recent years, tourism development is shifting toward mass tourism, and local residents are seeking avenues to sustain their livelihoods. In Placencia, the need for effective monitoring and management of Marine Protected Areas, fisheries, and …

Whiting Events Off Southwest Florida: Remote Sensing And Field Observations, Jacqueline Long

USF Tampa Graduate Theses and Dissertations

“Whiting” is a term used to describe a sharply defined patch of water that contains high levels of suspended, fine-grained calcium carbonate (CaCO₃). These features are named for their bright (at times white) appearance when compared to surrounding waters, and have been found to occur globally, persisting for multiple consecutive days. Although whitings have been widely studied using chemical, biological, geological, and physical techniques, there has been little effort to document their spatio-temporal distributions in a systematic way, not to mention the lack of consensus on what generates whitings and allows them to persist for days to weeks …

Automatic Pain Assessment From Infants’ Crying Sounds, Chih-Yun Pai

USF Tampa Graduate Theses and Dissertations

Crying is infants utilize to express their emotional state. It provides the parents and the nurses a criterion to understand infants’ physiology state. Many researchers have analyzed infants’ crying sounds to diagnose specific diseases or define the reasons for crying. This thesis presents an automatic crying level assessment system to classify infants’ crying sounds that have been recorded under realistic conditions in the Neonatal Intensive Care Unit (NICU) as whimpering or vigorous crying. To analyze the crying signal, Welch’s method and Linear Predictive Coding (LPC) are used to extract spectral features; the average and the standard deviation of the frequency …

Hidden Markov Chain Analysis: Impact Of Misclassification On Effect Of Covariates In Disease Progression And Regression, Haritha Polisetti

USF Tampa Graduate Theses and Dissertations

Most of the chronic diseases have a well-known natural staging system through which the disease progression is interpreted. It is well established that the transition rates from one stage of disease to other stage can be modeled by multi state Markov models. But, it is also well known that the screening systems used to diagnose disease states may subject to error some times. In this study, a simulation study is conducted to illustrate the importance of addressing for misclassification in multi-state Markov models by evaluating and comparing the estimates for the disease progression Markov model with misclassification opposed to disease …

Analysis Of Managerial Decision-Making Within Florida’S Total Maximum Daily Load Program, Justin Barthle

USF Tampa Graduate Theses and Dissertations

Water quality has evolved legislatively from protection of navigation routes and quantity of sources to more emphasis on impairments on water quality for surface and groundwater sources. Nonpoint or diffuse sources of impairments represents a major challenge for management due to the complexity of its sources and difficulty in tracking.

The most cited sections on public policy analysis focuses on the overall process agencies employ to understand the results the program yields. Often overlooked are finer details and mechanisms, such as decision-making and priority setting, which have a great impact on the overall process. To investigate these factors, we need …

Metal-Organic Frameworks As Potential Platforms For Carbon Dioxide Capture And Chemical Transformation, Wenyang Gao

USF Tampa Graduate Theses and Dissertations

The anthropogenic carbon dioxide (CO₂) emission into the atmosphere, mainly through the combustion of fossil fuels, has resulted in a balance disturbance of the carbon cycle. Overwhelming scientific evidence proves that the escalating level of atmospheric CO₂ is deemed as the main culprit for global warming and climate change. It is thus imperative to develop viable CO₂ capture and sequestration (CCS) technologies to reduce CO₂ emissions, which is also essential to avoid the potential devastating effects in future. The drawbacks of energy-cost, corrosion and inefficiency for amine-based wet-scrubbing systems which are currently used in industry, …