Physical Sciences and Mathematics Commons^™

Linear Extremal Problems In The Hardy Space HP For 0 < P < 1, Robert Christopher Connelly

USF Tampa Graduate Theses and Dissertations

In this thesis, we consider linear extremal problems in the H^p spaces. For many of these extremal problems, a unique solution can be guaranteed. We will examine some of the classical examples of extremal problems in these spaces. With this framework in place we will then consider a particular problem which does not always have a unique solution.

Forging Blockchains: Spatial Production And Political Economy Of Decentralized Cryptocurrency Code/Spaces, Joe Blankenship

USF Tampa Graduate Theses and Dissertations

Cryptocurrencies and blockchains are increasingly used, implemented and adapted for numerous purposes; people and businesses are integrating these technologies into their practices and strategies, creating new political economies and spaces in and of everyday life. This thesis seeks to develop a foundation of geographic theory for the study of spatial production within and surrounding blockchain technologies focusing on acute studies of Bitcoin as cryptocurrency, Ethereum as digital marketplace, and their conditions of possibility as decentralized autonomous organizations. Utilizing concepts from Henri Lefebvre's Production of Space, this thesis situates blockchain technologies within the wider discussion about the political economy of …

Latitudinal Position And Trends Of The Intertropical Convergence Zone (Itcz) And Its Relationship With Upwelling In The Southern Caribbean Sea And Global Climate Indices, Kaitlyn E. Colna

USF Tampa Graduate Theses and Dissertations

The Intertropical Convergence Zone (ITCZ) is a feature that results from the ocean-atmosphere interactions in the tropics around the world. The ITCZ is characterized by surface wind convergence, tall storm clouds, and it forms a belt of high time-averaged precipitation around the globe. The ITCZ undergoes seasonal migrations between 5°S and 15°N roughly following the subsolar point on Earth with the seasons, with a mean annual position located slightly above the Equator, between 2° and 5°N.

This study tested the hypothesis that there was a northward shift in the median position of the ITCZ in the first decade of the …

Spatio-Temporal Dynamics Of Soil Composition And Accumulation Rates In Mangrove Wetlands, Joshua L. Breithaupt

USF Tampa Graduate Theses and Dissertations

Coastal wetlands are globally important environments for biogeochemical cycling and are the object of intensive research related to the sequestration and exchange of carbon with oceans, continents, and the atmosphere. Wetland soil core records of organic carbon (OC) provide insights about future ecosystem responses to global change by identifying temporal variability in the context of environmental changes including sea level rise (SLR), anthropogenic reductions in freshwater flow, and landscape-scale disturbance events. My studies of Gulf of Mexico mangroves involved the use of radiometrically-dated soil cores to identify spatial and temporal accumulation trends of various constituents including organic and carbonate carbon, …

Stormwater Infiltration And Groundwater Integrity: An Analysis Of Bmp Siting Tools And Groundwater Vulnerability, Kristopher Craig Gallagher

USF Tampa Graduate Theses and Dissertations

Nonpoint source pollution captured by urban stormwater runoff is the greatest challenge for surface water quality improvements. Computer-based design tools have been developed to help mediate this issue by guiding end users through the implementation of decentralized stormwater management. The majority of these tools focus on treatment via biofiltration, yet concern regarding this treatment regime is rising. Case studies from research past clearly indicate the susceptibility of groundwater to contamination from extensive anthropogenic activity at the surface. Contaminants, such as nitrates and pathogens, are not completely removed before runoff enters the underground watercourse. Additionally, national and state legislation, which explicitly …

Fatty Acid Biomarker Detection For Breast Cancer Using Differential Mobility Spectrometry With Non-Radioactive Ion Source, James Joseph Alberti

USF Tampa Graduate Theses and Dissertations

Differential Mobility Spectrometry (DMS) using a non-radioactive ion source (NRIS) is investigated as a possible medical diagnostic instrument for near real-time detection of breast cancer biomarkers. In previous clinical studies, concentrations of Linoleic, Palmitic and Stearic fatty acids have been observed at different levels in women with carcinoma breast cancer versus women with benign tumors or healthy women showing no signs of breast cancer. Present diagnostic methods require a biopsy of the suspect tissue and a microscopic lab analysis performed to determine its disease state. This process can take hours or days before the patient and doctor are informed of …

How Lessons From A Past Disaster Can Influence Resilience And Climate Adaptation In Broward County, Florida, Hannah Rose Torres

USF Tampa Graduate Theses and Dissertations

In the face of future uncertainties, many places are struggling with decisions about how to prepare for and adapt to climate change. The purpose of this research is to shed light on the concept of resilience, and uncover lessons for resilience-building exposed by a past disaster, Hurricane Wilma.

The dissertation begins with an introduction (Chapter 1) detailing the research problem, key terms and overall research design. The study was conducted in three distinct phases. The first phase (Chapter 2), explored the concept of resilience to understand how it was defined in three South Florida communities. Content analyses of city and …

Geographical Information Systems (Gis) Applied To Urban Nutrient Management: Data Scarce Case Studies From Belize And Florida, Charlotte Juliane Haberstroh

USF Tampa Graduate Theses and Dissertations

Nutrient inputs into the environment greatly impact urban ecosystems. Appropriate management strategies are needed to limit eutrophication of surface water bodies and contamination of groundwater. In many existing urban environments, retrofits or complete upgrades are needed for stormwater and/or wastewater infrastructure to manage nutrients. However, sustainable urban nutrient management requires comprehensive baseline data that is often not available. A Framework for Urban Nutrient (FUN) Management for Geographic Information Systems (GIS) was developed to specifically address those areas with limited data access. Using spatial analysis in GIS, it links water quality, land use, and socio-demographics, thereby reducing data collection and field-based …

Initial Comparative Empirical Usability Testing For The Collaborative Authentication System, Kim Bursum

USF Tampa Graduate Theses and Dissertations

The Collaborative Authentication (co-authentication) system is an authentication system that relies on some or all members of a pre-registered set of secure hardware tokens being concurrently present to an authentication server at the moment of authentication. Previous researchers have compared various embodiments of the co-authentication system to each other including using Quick Response (QR) codes/cellphone cameras and Near Field Communication (NFC) between tokens. This thesis concerns the initial design and implementation of empirical comparative testing mechanisms between one embodiment of the co-authentication system and other commonly used authentication systems. One contribution is the simulated standard user ID and password login …

New Reaction Discoveries In Gold Catalysis, Seyedmorteza Hosseyni

USF Tampa Graduate Theses and Dissertations

In this dissertation, gold catalyst was employed to catalyze intermolecular reactions. Intramolecular reactions were far more advanced than intermolecular reaction in gold catalysis. With finding suitable ligands for gold catalysts, we were able to develop several transformations to synthesize interesting building blocks in organic chemistry including: allenes, furans, spiros, oxepines, propargyl ethers and ketones. These functionalities were synthesized by the use of triazole-gold(I) catalyst. Triazole, as a ligand bond to gold, showed enhanced stability of the catalyst, which resulted in better yields. Gold(I)/(III) redox chemistry also used for cyclopropanol ring openings which resulted in synthesizing substituted ketones.

Southern Ocean Transport By Combining Satellite Altimetry And Temperature/Salinity Profile Data, Michael Kosempa

USF Tampa Graduate Theses and Dissertations

Zonal geostrophic velocity fields above 1975 dbar have been estimated for the Southern Ocean from 2004 to 2014 based on sea surface topography observed by Jason altimetry and temperature/salinity measured by Argo autonomous floats. The velocity at 1000 dbar estimated has been validated against Argo drift trajectory at the same pressure level available from the Asia Pacific Data Research Center (APDRC). Errors in mapping of dynamic ocean topography, temperature, and salinity have been quantified using the Southern Ocean State Estimate (SOSE). Analysis of errors reveals significant correlations between depth-dependent and –independent contributions to the integrated transport. Further analysis revealed optimal …

Land Use, Stream Stability, And Benthic Invertebrates In A Dry Forest Watershed Of Western Costa Rica, Jacqueline Ann Demko

USF Tampa Graduate Theses and Dissertations

There is a paucity of data on dry forests, the most threatened biome in the tropics. The Nandamojo is a tropical dry forest watershed in Western Costa Rica that has been impacted by varying degrees of human induced modifications. This research was conducted to examine the influence of land use and channel characteristics on invertebrate communities within a sub basin of the Nandamojo watershed. This study addressed three hypotheses: (1) sites with low tree cover and small riparian buffer zones will have high erosion, (2) macroinvertebrate abundance will be lower at sites with low channel stability values, and (3) benthic …

Effects Of Anthropogenic Activity On The Green Swamp Preserve Ecosystem, Barbara Ann Nordheim-Shelt

USF Tampa Graduate Theses and Dissertations

The Green Swamp Preserve is a large geographic area that has sustained many changes since Europeans settled in Florida. There has been little published research on the impacts of anthropogenic activity on this system. This thesis research seeks to document more recent changes in the Green Swamp and to evaluate the effects of various human activities on the system. The study period is from 1985 to 2015. For this time period changes in land use and landcover were examined using neural network classifications. Changes in vegetation health were evaluated by examining Normalized Difference Vegetation Index (NDVI) and Green Vegetation Index …

Hydroalkynylation Of Oxocarbenium Intermediates Via Au(I) Catalysis, Courtney Smith Smith

USF Tampa Graduate Theses and Dissertations

Au(I) catalysis has recently emerged as a powerful tool for the realization of a broad range of organic transformations. Despite this rapid development, attaining selectivity and maintaining catalyst stability remain significant challenges. Rational ligand design, such as the employment of NHC or TA ligands, has been used to confront these issues. This thesis focuses on the use of Au(I) catalysts bearing these ligands for the selective hydroalkynylation of enol ethers. By employing a TA-Au stabilized catalyst, [(OAr)₃PAu(TA-H)]OTf, the intermolecular hydroalkynylation of enol ethers, a substrate that is well-known to promote decomposition of the gold cation, was efficiently achieved. …

What Makes Water Policy Sustainable? An Analysis Of Water Policy In Us Cities, Rebecca Brady David

USF Tampa Graduate Theses and Dissertations

This dissertation works to create a clearer understanding of sustainability in water policy. Current water policy in four US cities was compared to a matrix of recommended sustainability themes that have been presented in the literature to determine the extent of which these themes have been implemented into water policy. To best analyze policy for sustainability it is necessary to look at the policy of cities that are considered sustainable. This was determined by a city’s inclusion in “Most Sustainable US Cities” lists. The two cities that best represented sustainability were Austin, TX and San Francisco, CA. The research also …

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 …

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 …

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 …

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 …

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 …

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 …

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 …