Digital Commons Network^™

Aqueous Humor Dynamics And Compound Action Potentials In The Anesthetized And Conscious Freely Moving Rat, Youssef Mohamed

USF Tampa Graduate Theses and Dissertations

Vision is dependent on the proper functioning of many intricate components of the eye. Aqueous humor dynamics function to keep the eye inflated at the right pressures and nourish avascular tissue in the eye while properties of the corneoscleral shell dictate how dynamic changes in volume and pressure affect tissue at the optic nerve head. Retinal ganglion cells exit the globe at the optic nerve head and carry all of the visual information to the brain for perception of visual stimulus. In this dissertation, we aim to present a lumped parameter model of the eye that can accurately describe the …

Educational Language Policy: An Examination Of Race And Language In Policy Discourse, Dionne L. Davis

USF Tampa Graduate Theses and Dissertations

Linguistic diversity is an integral thread in the tapestry of America. As such researchers how linguistic differences across ethnoracial groups can be understood as resources rather than problems. The aim of this study was to examine ideologies concerning race/ethnicity and language in the discourse of educational language policies that guide multilingual approaches to education. The design of this study was critical discourse policy analysis, and the framework was a combination of Critical Language and Race Theory, also known as LangCrit (Crump, 2014), and Raciolinguistics (Alim, 2016; Flores and Rosa, 2015). The research questions were: (1) How are ideologies about the …

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 …

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 …

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 …

Organizing Economies: Narrative Sensemaking And Communciative Resilience During Economic Disruption, Timothy Betts

USF Tampa Graduate Theses and Dissertations

This dissertation unites organizational communication, and economic theory to understand how individuals make sense of economic crises, imbed power and logic in those understandings, and construct new economic realities in the aftermath of crisis. Contra economic orthodoxy, this project conceives of economy and economics as a social construct. As a social construct, individuals organize economy and economics through discourse, make sense of through narrative, and rebuild through communication. This dissertation combines different theoretical perspectives—actor-network theory, antenarrative organization theory, and the communication theory of resilience—to recenter social scientific accounts of economic reality around communication, story, and power.

Specifically, I focus on …

Development And Analysis Of Green Pathways For Biphasic Extraction At High Pressure, Kyle L. Cogswell

USF Tampa Graduate Theses and Dissertations

Technological advancements over the last century have allowed for advancements not only in science and engineering but medicine as well. The use of supercritical fluids for processing continues today after its initial boom in the latter part of the last century; often being paired with co-solvents to extend the range of use for this technique. Supercritical fluid extraction may be paired with pressurized warm water extraction to yield a new intensified process for biphasic extractions that improves efficiency and reduces waste. This combination may be used to replace sequential extraction processes or supercritical extraction processes that make use of organic …

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 …

Two Essays In Applied Microeconomics: Retirement, Income Inequalities, And Other Economic Indicators Of Health And Life Satisfaction, Zahra Akbari

USF Tampa Graduate Theses and Dissertations

The following proposal includes two essays in applied microeconomics. The first essay studied the relationship between income differences among siblings and the health outcomes of the individuals. Health inequalities and the factors associated with them have been a significant interest of health economists. Among those factors that can lead to health differences in adulthood, many studies have studied financial status. There are still many questions about these factors which should be answered in this area, especially about the adulthood income relative to a reference group and how it can be related to differences in adulthood health. The main goal of …

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 …

Evaluation Of Aluminum Dissolution, Current Density, And Pitting Patterns During Electrocoagulation, Monica Castro Carias

USF Tampa Graduate Theses and Dissertations

Electrocoagulation (EC) is a sustainable water treatment process involving the generation of coagulants on-site through the application of a voltage on metal (usually aluminum or iron alloys). The factors that impact EC system performance have been well researched, however further research is needed on the factors that impact anodic dissolution of aluminum electrodes, especially when the technology is transferred to full-scale applications. Electrode fouling is one of the factors that can impact dissolution of the anode during EC due to the formation of a protective oxide/hydroxide layer on the electrode surface. Previous studies have addressed electrode fouling by reversing polarity, …

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 …

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 …

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 …

Hybrid Rans-Les Hemolytic Power Law Modeling Of The Fda Blood Pump, Joseph Tarriela

USF Tampa Graduate Theses and Dissertations

This study applies the SBES and IDDES hybrid RANS-LES turbulence models along with the K-ω SST model to four flow conditions of the FDA blood pump. Validation of all three turbulence models show good agreement with experimental pressure and velocity fields. Evaluation of turbulent kinetic energy fields for the hybrid models show 80-90+% of kinetic energy is resolved in the rotor and diffuser regions of the pump. Hemolysis power law models were evaluated using the commonly used von Mises stress and additional energy dissipation stress (EDS). Results show viscous and Reynolds stresses computed with the K-ω SST under predict and …

Impedance Analysis Of Anodized Aluminum And Structural Bridge Tendons, Justin Silnutzer

USF Tampa Graduate Theses and Dissertations

This is a two-part thesis with the overall investigation technique being electrochemical impedance spectroscopy (EIS). In the first part, EIS is used to estimate the layer thickness of anodized aluminum oxide. This required the development of an appropriate electrical circuit model; that with parameters that correspond to physical properties of the oxide. In this work, it was found that for thicker oxides of which the outer porous layer is greater than 12 microns, impedance may be used to estimate the outer layer thickness. However, further research is required to understand the role of outer porous layer structure on the impedance …

Computational Methods For Solving The Combinatorial Optimization Problems In Transportation, Xufei Liu

USF Tampa Graduate Theses and Dissertations

This dissertation discusses three transportation problems. The first problem is a bi-level optimization problem that simultaneously optimizes facility locations and network design in hazardous materials transportation. In the upper level, the leader intends to reduce the facility setup cost and the hazmat exposure risk, by choosing facility locations and road segments to close for hazmat transportation. When making such decisions, the leader anticipates the response of the followers who want to minimize the transportation costs. A robust optimization approach with multiplicative uncertain parameters and polyhedral uncertainty sets is applied to deal with the uncertain risk and demand.

The second problem …

Exploration Of Energy Efficient Computing For Data-Intensive Applications, Md Adnan Zaman

USF Tampa Graduate Theses and Dissertations

The recent surge of data-intensive applications has stretched the performance and energy limit of today’s traditional computing system. The massive amount of data generated by data-intensive applications is not processed at the same speed due to bandwidth mismatch between the faster processing unit and slower memory. Memory access and communication bandwidth can be identified as the primary bottlenecks. Consequently, these two bottlenecks make up most of the total energy consumption. In light of this, we explore energy-efficient computing for data-intensive applications. We examine different aspects of two computing systems, such as in-memory computing and AI-enabled edge computing, more popularly known …

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 …

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 …

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 …

High School Teachers’ Perceptions Of Promoting Student Motivation And Creativity Through Career Education, Kyeonghyeon Park

USF Tampa Graduate Theses and Dissertations

This study aimed to investigate teachers’ perceptions and experiences of career education as to how career education shapes students’ intrinsic motivation and creativity in a high school in South Korea. Career education in South Korea aims to help students discover their interests, skills, aptitudes, and passions, and to help them understand what they need to achieve their goals in the future through the opportunities of various experiences. Career education can help students increase their intrinsic motivation and creativity as well as discover future occupations through various types of activities. This study was informed by two theoretical frameworks, Self-determination theory and …

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.

Healthcare Profession Students Of Color Participating In International Service-Learning, Ellyn Katherine Couillard

USF Tampa Graduate Theses and Dissertations

This qualitative exploratory case study investigated the healthcare profession students’ of color experience and the perceived impact of completing international service-learning (ISL). Before this study, most of the research about healthcare profession students in ISL reported had mainly White participants or reported data and findings in the aggregate. To complete this research, I performed two semi-structured interviews with each of the five participants incorporating photo-elicitation techniques. Then I performed constant comparative methods and communicated with a peer debriefer about my findings. Five participants were selected using max maximum variation based on racial, ethnic, and cultural backgrounds, programs of study, and …