Physical Sciences and Mathematics Commons^™

Joint Models For Repeated Measured, Non-Normally Distributed Multilevel Data, Weiwei He

USF Tampa Graduate Theses and Dissertations

Clinical trials have tended to collect both survival information and longitudinal biomarkers, as well as other covariates. In order to better assess the severity of diverse diseases, we need to collect various longitudinal outcomes. Furthermore, longitudinal data could consist of a number of different measurements of varying types. The multilevel item response theory (MLIRT) model has been widely used in several fields such as public health and health sciences for multivariate longitudinal outcomes. Joint models combining the longitudinal and survival processes, as well as the relation between them, have been developed to minimize bias and improve the efficiency of estimates. …

Advanced Analytical Method Development: From Highly-Enrolled Classroom To Data-Intensive Proteomics, Laxmi Sinduri Vuppala

USF Tampa Graduate Theses and Dissertations

In analytical chemistry, method development is key to identifying, separating, and quantifying chemical components of interest systems. The chemical aspects are fundamental to understanding the subject of any analytical system, whether in academic research, industry, or government. These methodologies serve as a bridge between the classroom, where students are taught to be curious and enlightened, and research, where one strives to contribute. The Ph.D. dissertation integrates advanced methodologies in basic and applied research and advanced instrumentation, but the core criteria for validation remain the same. As part of chemical education curriculum development, a large cohort of undergraduates performed two gas …

Coupling 210Pb And 14C To Constrain Carbon Burial Efficiency Of Blue Carbon Ecosystems, Tynisha R. Martin

USF Tampa Graduate Theses and Dissertations

Blue carbon ecosystems cover a small global area but have the potential to sequester large amounts of organic carbon (OC) from the coastal ocean in the sediment. Organic carbon is continually remineralized and exported in the dissolved form, which is currently only poorly accounted for in blue carbon budgets. Constraining carbon cycling in blue carbon systems is complicated by the range of carbon sources and sinks in the system and high export rates from the system. By coupling 14C and 210Pb chronometers to ascertain the amount of primary production stored within peat, it is possible to study carbon transport through …

Functional Morphology And Taphonomy Of Ordovician–Silurian Diploporan Echinoderms, Stephen Ashley Hill

USF Tampa Graduate Theses and Dissertations

Diploporan echinoderms were one of the most speciose groups of stemmed echinoderms during the Ordovician. Despite this widespread abundance, the fossil record of diploporan fauna consists primarily of incomplete specimens, with complete specimens being rare. While the theca, or body, is more commonly preserved, the feeding appendages and the attachment structures (i.e. stems or holdfasts) are seldomly preserved. Insight into these features is highly valuable to the understanding the paleoecology, like the feeding and respiratory strategies, of these enigmatic creatures.

One group of diploporan echinoderms which does have an extensive fossil record, is the Holocystites Fauna, primarily known from the …

Inland Tropical Cyclone Intensity Decay In The Continental United States, Yijie Zhu

USF Tampa Graduate Theses and Dissertations

Tropical cyclone (TC) hazard preparation is mostly focused on coastal cities with less attention typically paid to inland regions. The impact of TCs that propagate far inland is often underestimated and can cause unexpected loss of life and economic loss. This dissertation aims to understand the decay process of TCs during the post-landfall stage by answering three main research questions: (1) What are the general patterns of inland tropical cyclones, including spatial variations, decay rates, and translation speeds? (2) Are there temporal changes in the intensity decay from inland moving hurricanes? (3) How is the hurricane post-landfall dissipation related to …

The Effects Of Temperature And Oxygen Availability On Aerobic Performance In Three Coastal Shark Species; Squalus Acanthias, Carcharhinus Limbatus, And Carcharhinus Leucas, Alyssa M. Andres

USF Tampa Graduate Theses and Dissertations

Anthropogenically driven climate changes are altering marine habitats globally. Rising sea surface temperatures and coastal eutrophication, arising from global warming and coastal nutrient loading, have resulted in progressive ocean deoxygenation. This may restrict available habitat of marine organisms as studies suggest that the balance between metabolic oxygen demand and environmental supply plays an important role in limiting viable habitat and species fitness. As ectothermic predators, with temperature-dependent metabolism and high metabolic demands, coastal shark species may be susceptible to shifts in ocean temperature and oxygen. Such environmental changes may alter metabolic performance and ultimately success and survival within shark habitat. …

Nano-Optical Imaging Of 2d Materials In The Quantum Regime, Hana Nazari Hrim

USF Tampa Graduate Theses and Dissertations

Chemical vapor deposition (CVD) growth of atomically thin 2D materials, such as transition metal dichalcogenides (TMDs), is a complex process that has not been completely understood. Large-scale growth of monolayer TMDs often leads to polycrystalline films with heterogeneous morphological and optical properties. Previous optical studies of 2D materials by far-field photoluminescence (PL) provided insights into CVD growth mechanisms of simple crystals, which were, however, limited in spatial resolution due to the diffraction limit. Here we performed correlated morphological and tip-enhanced PL (TEPL) imaging of CVD-grown polycrystalline monolayer molybdenum diselenide (MoSe2) flakes with heterogeneous optical response. We observed nanoscale spatial variations …

Large Area Projection Sintering Of Semicrystalline Polymers And Part Analysis Of The Printed Specimens, Taranjot Kaur

USF Tampa Graduate Theses and Dissertations

As the requirements posed to products have increased in recent years. The trend towards individualized serial products steps up the need for respective manufacturing techniques to be more and more flexible. Conventional techniques of serial production, such as injection molding, are unable to fully meet the requirements of this trend. Additive manufacturing techniques generate components directly from a CAD data set while requiring no specific mold, producing minimal waste, and reaching satisfactory geometric accuracy. This is how, as opposed to conventional techniques, they comply with these increased demands to processing technology. Over the last two decades, the research community has …

Elucidating The Sources Supplying Aerosol Iron, Zinc, And Cadmium To The Surface Of The North Pacific Ocean With Stable Isotopes, Zach B. Bunnell

USF Tampa Graduate Theses and Dissertations

Transition metals, such as iron (Fe), zinc (Zn) and cadmium (Cd), are found at just trace amounts within the global oceans yet are vital for many biological functions of phytoplankton. As a result, these metals influence the ocean’s efficacy for carbon sequestration. Atmospheric dust is the primary input of Fe to various surface waters and may also supply Zn and Cd to oligotrophic surface waters. Here, I present Fe, Zn, and Cd isotope data from the US North Pacific GEOTRACES Section GP15 (Alaska-Tahiti) from the low-dust season (Sept. – Nov. 2018). Using this data and aerosol enrichment factors, I show …

Zooplankton Biodiversity In The Northeast Gulf Of Mexico And On The West Florida Shelf From 2005 - 2014, Megan Ferguson

USF Tampa Graduate Theses and Dissertations

Zooplankton abundance and biodiversity was measured in the northeast Gulf of Mexico (NEGoM) and on the West Florida Shelf. Bongo net samples were collected between May 2005 to September 2009 through the SEAMAP program, and between July 2010 to August 2014 through the C-IMAGE program. Calanoid copepods were the most abundant zooplankton group in most of the samples collected, but ostracods, larvaceans, and chaetognaths were also abundant. Shannon and Inverse Simpson indices were calculated for all zooplankton samples and generally showed similar trends, but only Shannon indices were used for statistical analyses. In the winter and spring there were significant …

A Protein-Based Therapeutic Combination For The Treatment Of Hard-To-Heal Wounds, Graham L. Strauss

USF Tampa Graduate Theses and Dissertations

Chronic wounds present many clinical challenges in relation to the successful treatment and closure of the damaged tissue. Most current treatment methods focused on one or two aspects to drive wound closure, while most chronic wounds are multifactorial environments with many of those dependencies relying on the termination of one another to effectively gain tissue construction, closure, and full skin thickness and composition. Natural wound healing processes allude to potential biologics that can impede the chronic breakdown of tissue, while restoring deposition of new tissue, and effectively leading to a healed wound. Proteases secreted by the body’s immune system lay …

Ocean Eddies And Frontal Zones In The Gulf Of Mexico And Straits Of Florida, Yingjun Zhang

USF Tampa Graduate Theses and Dissertations

Ocean eddies and fronts in the Gulf of Mexico (GoM) and the Straits of Florida (SoF) play important roles in ocean physics, biology, and ecology. These two ubiquitous physical features have been studied worldwide for decades, yet many questions remain unanswered or poorly studied for the GoM and SoF. This study aims to improve the understanding of ocean eddies and frontal zones in the GoM and SoF using satellite remote sensing, in situ observations and model outputs, as well as state-of-the-art algorithms, with the following objectives: 1) analyze the three-dimensional (3-D) statistical characteristics and thermohaline structure of mesoscale eddies in …

An Integrated Approach For Dynamic Process Modeling And Optimization Of Wastewater Treatment Facilities, Komal Rathore

USF Tampa Graduate Theses and Dissertations

The subareas of process systems engineering including process modeling, simulation, and optimization are becoming progressively substantial for understanding processes, making decisions, improving efficiency, and complying with stricter environmental and safety legislation. Additionally, the availability of user-friendly flowsheet simulators and computational resources with the current trend of data collection and analysis has allowed for a more accurate representation of complex processes such as wastewater treatment systems. Despite all the progress in the areas of process modeling and simulation, the first-principle mechanistic models for wastewater treatment processes are at best employed during the design stage, and therefore, not used optimally for day-to-day …

Assessing The Human-Health Risk Of Exposure To Pathogens From Beach Sands, Javier Federico Gallard-Góngora

USF Tampa Graduate Theses and Dissertations

Fecal contamination at recreational beaches impacts the health of beachgoers, through the introduction of disease-causing microorganisms, and the well-being of communities dependent on income from recreational beach activities. Beach ecosystems are also impacted by sewage through the introduction of nutrients that can cause abnormal increases in autochthonous microorganisms which can impact the population of larger organisms in the ecosystem. Fecal contamination is introduced into sand via untreated sewage, direct deposition of human feces into sand, runoff, and deposition of animal feces into sand. The introduction of fecal contamination into sand exposes individuals to pathogens (disease causing microorganisms) which can result …

Interdisciplinary Communication By Plausible Analogies: The Case Of Buddhism And Artificial Intelligence, Michael Cooper

USF Tampa Graduate Theses and Dissertations

Communicating interdisciplinary information is difficult, even when two fields are ostensibly discussing the same topic. In this work, I’ll discuss the capacity for analogical reasoning to provide a framework for developing novel judgments utilizing similarities in separate domains. I argue that analogies are best modeled after Paul Bartha’s By Parallel Reasoning, and that they can be used to create a Toulmin-style warrant that expresses a generalization. I argue that these comparisons provide insights into interdisciplinary research. In order to demonstrate this concept, I will demonstrate that fruitful comparisons can be made between Buddhism and Artificial Intelligence research.

Explainable And Cooperative Autonomy Across Networks Of Distributed Systems, Peter Joseph Jorgensen

USF Tampa Graduate Theses and Dissertations

Large networks of complex systems-of-systems are commonplace and evermore present in both mundane and extraordinary facets of human existence. From the exponential growth of connectivity via the internet and other information networks, to the miniaturization of computers and sensors, to cross-domain sensor and communication networks, these networks of distributed systems-of-systems (NDSS) present incredible benefits and challenges. Autonomy is perhaps the most important and most difficult to achieve enabling technology for efficient performance of the NDSS. Giving each individual agent in a network the ability to manage its internal state in dynamic operating environments and in pursuit of multiple complex and …

Boundary Behavior Of Analytic Functions And Approximation Theory, Spyros Pasias

USF Tampa Graduate Theses and Dissertations

In this Thesis we deal with problems regarding boundary behavior of analytic functions and approximation theory. We will begin by characterizing the set in which Blaschke products fail to have radial limits but have unrestricted limits on its complement. We will then proceed and solve several cases of an open problem posed in \cite{Da}. The goal of the problem is to unify two known theorems to create a stronger theorem; in particular we want to find necessary and sufficient conditions on sets $E_1\subset E_2$ of the unit circle such that there exists a bounded analytic function that fails to have …

Multiple Solar Receivers Arrangement For High-Temperature Power Generation And Applications, Diego Jesus Guillen Perez

USF Tampa Graduate Theses and Dissertations

This dissertation presents an investigation of the specification and operation of multiple central solar receivers (CSR) sharing a heliostat field and an analysis of the receiver's thermal performance. A heliostat field was modeled in which different parts of the field aimed at different external or cavity receivers located on the same tower. Optical and thermal performance are analyzed, including the receivers' heat flux, solar thermal efficiency, and annual energy output. Some of the contributions of this research are:

1. Propose a novel configuration for a CSP power generation system using two receivers in a single central tower suitable …

Methods In Discrete Mathematics To Study Dna Rearrangement Processes, Lina Fajardo Gómez

USF Tampa Graduate Theses and Dissertations

In this work, we introduce novel tools to study DNA recombination pathways and measure their complexity. Genome rearrangement in some ciliate species can be modeled by subword pattern deletions in double-occurrence words (DOWs), words where each symbol appears exactly twice. The iterated deletions can be represented by a graph whose vertices are DOWs connected by an edge if one word can be obtained from the other through a pattern deletion. On this graph, called the “word graph”, we build a complex comprised of cells defined by Cartesian products of simplicial digraphs where we define a boundary operator and compute homology …

Data-Driven Analytical Predictive Modeling For Pancreatic Cancer, Financial & Social Systems, Aditya Chakraborty

USF Tampa Graduate Theses and Dissertations

Pancreatic cancer is one of the most deathly disease and becoming an increasingly commoncause of cancer mortality. It continues giving rise to massive challenges to clinicians and cancer researchers. The combined five-year survival rate for pancreatic cancer is extremely low, about 5 to 10 percent, owing to the fact that a large number of the patients are diagnosed at stage IV when the disease has metastasized. Our study investigates if there exists any statistical significant difference between the median survival times and also the survival probabilities of male and female pancreatic cancer patients at different cancer stages, and irrespective of …

Ice Deposits In Lava Tubes From West-Central New Mexico As Archives Of Past Volcanic Eruptions And Climate Change, Quinton Z. Vitelli-Hawkins

USF Tampa Graduate Theses and Dissertations

The Southwest of the United States is currently in a megadrought phase. Recent studies have shown that three of the most severe droughts of the last two millennia have occurred in the last 120 years, while geo-archaeological evidence suggests there were five megadroughts just from 150 to 950 CE. To try to better understand the causes of the droughts across the Southwest, a 110-cm long ice core was drilled from an ice deposit in a lava tube (Cave 29) from El Malpais National Monument in west-central New Mexico. The δ18O values in the ice core (ranging from −11.78 to −3.54‰) …

Improved Performance Of Silica-Supported La0.5Ba0.5Feo3 In The Reverse Water Gas Shift - Chemical Looping Process For Carbon Dioxide Reduction – A Density Functional Theory Study, Jiawei Guo

USF Tampa Graduate Theses and Dissertations

Global warming is increasingly obvious, and the reduction of greenhouse gases is an effective way to heal. Increasing the efficiency of catalysts that is applied in the industry can significantly reduce the emission of greenhouse gases. Reverse water gas shift chemical looping (RWGS-CL) is a promising reaction to convert CO2 to CO. La0.5Ba0.5FeO3 (LBF) is a good candidate for RWGS-CL, which shows increased conversion yield when supported on silica. This research focuses on identifying the mechanism of RWGS-CL via silica-supported LBF by exploring the oxygen vacancy formation energy (EO-vac). Density Functional Theory (DFT) is a powerful computational method to solve …

Nonparametric Estimation Of Transition Probabilities In Illness-Death Model Based On Ranked Set Sampling, Ying Ma

USF Tampa Graduate Theses and Dissertations

The ranked set sampling (RSS) design is applied widely in agriculture, environmental science, and medical research where the exact measurements of sampling units is costly, but sampling units can be ranked by a correlated concomitant variable. RSS is usually a cost-efficient alternate to simple random sampling (SRS) for selecting more representative samples. This study presents a novel methodology to investigate the nonparametric estimation of transition probabilities in illness-death model using the RSS design. We study the Aalen–Johansen estimator of transition probabilities in illness-death Markov model based on RSS design under random right censoring time and propose nonparametric estimators of the …

Antibiotic-Resistant Escherichia Coli And EnterococcusSpp. In Sand And Water At Tampa Bay Beaches, Jennifer K. Sabater

USF Tampa Graduate Theses and Dissertations

As antibiotic resistance in the environment continues to rise there is an increased concern that infections may become harder to treat as bacteria acquire genes for multidrug resistance. Recreational beach waters in the Tampa Bay area are routinely monitored by the Florida Department of Environmental Protection for the presence of fecal indicator bacteria (FIB) such as Escherichia coli and enterococci. Exceedances of beach action values (BAV) 235 CFU/100 mL (E. coli) and 70 CFU/100 mL (enterococci) indicate the presence of fecal contamination which is associated with an increased risk of disease for beachgoers. Antibiotic-resistant E. coli and Enterococcus spp. have …

Assessing Environmental Sensitivity In San Diego County, California, For Bird Species Of Special Concern, Eda Okan Kilic

USF Tampa Graduate Theses and Dissertations

It is widely recognized that desertification constitutes one of the biggest environmental problems on Earth. Desertification negatively impacts the future of humans and other living things all over the globe. Therefore, the assessment of desertification is essential to both monitor and combat desertification. A number of models are routinely applied to assess desertification. The MEDALUS model is one of the most popular approaches, identifying desertification risk based on an environmentally sensitive area index (ESAI) that integrates climate, vegetation, soils, groundwater, and socio-economic factors to obtain an overall rating. The goal of this study was to measure the potential impacts of …

A Technique-Based Approach To Structure-From-Motion: Applications To Human-Coastal Environments, Robert Van Alphen

USF Tampa Graduate Theses and Dissertations

Photogrammetry is a method by which physical information can be extracted from thecorrespondence of 2-dimensional images. In the geosciences, Structure-from-Motion (SfM) photogrammetry is a technique that has seen considerable interest in the past decade of research. Here I present three case studies of various scope and methodologies which can inform the use of SfM in the geosciences. First, I discuss the theoretical and algorithmic basis of SfM photogrammetry and its uses thus far in the geosciences. Chapters two through four show specific studies which highlight several approaches to SfM and the data which can be produced. Chapter five then concludes …

New Developments In Statistical Optimal Designs For Physical And Computer Experiments, Damola M. Akinlana

USF Tampa Graduate Theses and Dissertations

Statistical design of experiments allows for multiple factors influencing a process to be systematically manipulated in an experiment, and their effects on the output of the process to be studied via statistical modeling and analysis. Classical designs offer general nice performance but have limited applications due to restricted design size, region, and randomization structure. Computer generated optimal designs become more popular in recent decades due to the rapid growth in computing power. Most existing work in optimal design of experiments involves designing experiments with optimal performance on a single chosen objective or a single response. However, with the increasing limitation …

Chronological Accumulation Of Microplastics In The Gulf Of Mexico And Their Acute Effects On Coral Bleaching, Martina M. Plafcan

USF Tampa Graduate Theses and Dissertations

Microplastics have accumulated in the environment since plastic production began. They have spread to all areas of the globe from marine trenches to mountains and they can be harmful to organisms. However, research on microplastics has only recently begun so it is unclear how they have changed over time in many regions of the ocean and how current oceanic concentrations might affect marine life. Additionally, organisms such as corals are under stress and have been declining due to climate change, so it is not yet known if microplastics exacerbate these threats. My thesis addressed these gaps in the literature by …

Determining Depth Of Closure Based On Time-Series Beach Profiles And Empirical Formulas: A Case Study Along The Florida Coast, Elizabeth Royer

USF Tampa Graduate Theses and Dissertations

Depth of closure (DOC) is defined as the most landward depth seaward of which there is no significant change in bed elevation and no significant net sediment exchange between the nearshore and the offshore over a certain period of time, such as 5 to 20 years. DOC is an essential parameter used in beach and shore protection, sediment management, and many other aspects of coastal studies. Taking advantage of advancements in wave hindcast and bathymetry measurement in the past 20 years (2000-2019), this study determined the DOC at 12 locations along the Florida coast, including three from the northwest Gulf …

On Simultaneous Similarity Of D-Tuples Of Commuting Square Matrices, Corey Connelly

USF Tampa Graduate Theses and Dissertations

It has been shown by B. Shekhtman that when any d-tuple A of pairwise commuting N × N matrices with complex entries is cyclic, then A is simultaneously similar to the d-tuple of commuting N × N matrices B if and only if B is cyclic, and the sets of polynomials in d variables which annihilate A and B are equivalent.

This thesis offers a further generalization of this result, demonstrating the necessary and sufficient conditions for the simultaneous similarity of n-cyclic d-tuples of commuting square complex-valued matrices.