Digital Commons Network^™

An Integrated Pcb-Based Heating And Auto-Ranging Platform For Volatile Organic Compound (Voc) Detection Using Carbon Nanotube Based Sensors, Thomas Kalach

USF Tampa Graduate Theses and Dissertations

This thesis presents the development, characterization, and integration of a novel low-cost, high-dynamic-range sensor platform for the detection of volatile organic compounds (VOCs), leveraging the unique electrical properties of carbon nanotube (CNT) thin films. The platform introduces a fully integrated auto-ranging analog front-end circuit capable of real-time resistance measurement spanning over eight orders of magnitude ranging from tens of ohms to hundreds of megaohms, without compromising signal resolution or precision. This was achieved through a digitally controlled, multi-path feedback architecture and controllable current source.

To further enhance sensor performance, the system incorporates a copper trace heater beneath the sensor array, …

A Discussion Of Community: An Ethnography Of Designing Asynchronous Video Discussions To Reveal Student Perceptions Of Digital Presence In Online Learning, Chad S. Garcia

USF Tampa Graduate Theses and Dissertations

This mixed-methods digital ethnography investigates how video-based discussions (VBD) influence community building in asynchronous graduate education. Using the Community of Inquiry (COI) framework, this study looks at student experiences in a History of Higher Education class where traditional text-based discussions were replaced with video presentations and peer responses. The research explores how video discussions affect students' sense of presence, how video presence impacts engagement patterns, and which multimedia elements contribute to community development.

Data collection included semi-structured interviews with students and instructors, LMS analytics, video content analysis, and ethnographic observation throughout Spring 2024. Analysis revealed a notable disconnect between traditional …

Introductory Chemistry Student Success: Investigating Study Strategies And Evaluating An Informative Utility Value Intervention, Pallavi Nayyar

USF Tampa Graduate Theses and Dissertations

Improving retention in STEM (science, technology, engineering, and mathematics) programs is essential to meet the growing demand for skilled professionals in the domestic workforce. To achieve this, it is critical to understand and address the factors that influence student persistence in STEM degrees. Gateway courses such as general chemistry often serve as early barriers to STEM degree completion, with high rates of attrition that impact not only individual students but also institutions and society. Therefore, the aim of this work was to examine and influence the factors that contribute to student withdrawal from introductory chemistry courses in order to promote …

Investigating Factors Influencing Organic Chemistry Learners' Explanation Sophistication And Representational Competence, Caroline J. Crowder

USF Tampa Graduate Theses and Dissertations

The research presented in this dissertation has two themes: organic chemistry learners’ written explanations and representational competence. Chapters 3 and 4 explore how organic chemistry learners construct explanations of reaction mechanisms, specifically focusing on electrophile and nucleophile components. Chapter 5 investigates organic chemistry learners’ representational competence skills and the relationship between these skills and their performance in the course.

Understanding reaction mechanisms is critical for success in organic chemistry, yet learners often struggle to reason beyond explicit, surface-level features. Constructed-response prompts that ask learners to explain what is happening in a reaction mechanism and why it occurs can provide insight …

Mode Engineering And Functional Enhancement In Piezoelectric-On-Silicon Mems Resonators With Magnetic Field Sensing Applications, Ugur Guneroglu

USF Tampa Graduate Theses and Dissertations

This dissertation significantly advances the field of micro-electro-mechanical systems (MEMS) resonators by exploring novel post-fabrication tuning techniques, electrode configuration effects, and innovative sensor applications for thin-film piezoelectric-on-silicon (TPoS) resonator devices. Driven by the increasing demand for tunable, high-precision and robust MEMS resonators in radio frequency (RF) applications such as sensing, timing, and filtering, this research aim to provide foundational knowledge and practical solutions for overcoming existing technological limitations. The dissertation is organized into three main research thrusts, each addressing critical challenges and opportunities in the design, fabrication, and application of TPoS MEMS resonators.

The first research thrust investigates an innovative …

Concentration And Composition Of Organic Contaminants In Blackfin Tuna, Yellowfin Tuna, And The Common Clubhook Squid In The Western Gulf Of Mexico, Lisa Rose-Mann

USF Tampa Graduate Theses and Dissertations

Cephalopods are an important component of pelagic food webs. They play ecological roles not only as predators but also as prey. However, their role as prey in the trophic transfer of organic contaminants to apex predators such as tunas in the Gulf of Mexico (GoM) is not well known. To investigate the importance of cephalopods in tuna diets, stomach samples were collected in February 2020 from tunas caught by rod and reel aboard the F/V Gulf Eagle near two large offshore floating oil/gas platforms in the northwestern GoM. Cephalopod samples were obtained from gut content analysis of 41 tunas caught …

Exploring System Identification Of Non-Linear Dynamics Using The Weighted Composition Operator And The Liouville Operator, Chukwuebuka Amagwula

USF Tampa Graduate Theses and Dissertations

System identification is the process of determining mathematical models that describe the dynamics of a system from data. Dynamic Mode Decomposition (DMD) and Sparse Identification of Nonlinear Dynamical Systems (SINDy) are two distinct approaches used for this purpose.

DMD identifies dominant spatiotemporal modes and eigenvalues that describe the evo lution of a system. It assumes a near-linear representation of dynamics and is closely linked to the Koopman operator, making it ideal for analyzing fluid flows, oscillatory systems, and modal structures. The DMD method uses time series data where each data point is referred to as a snapshot and represents the …

Beyond The Hype: The Fundamental Challenges Of Machine Learning-Based Android Malware Detection In Cybersecurity, Guojun Liu

USF Tampa Graduate Theses and Dissertations

Machine learning (ML) algorithms have achieved remarkable success across various domains, including cybersecurity. Inspired by these advancements, the academic security community has explored numerous ML-based approaches for Android malware detection. While ML holds significant promise in this domain, its practical deployment faces substantial challenges, including data collection, feature selection, app representation across different models, performance instability across datasets, and inherent limitations of learning-based malware detection. These challenges can lead to overly optimistic detection results and weaken the reliability of malware detection frameworks.

Android malware detection has been extensively studied using both traditional ML and deep learning (DL) approaches. Although many …

Phosphorus: From The Origins Of Life To The Origin Of An Industry, Joshua Abbatiello

USF Tampa Graduate Theses and Dissertations

The element phosphorus is a key biogenic element that is often the limiting reagent for life. Phosphorus is quickly bound by metal divalent cations making it virtually insoluble and inert in water (forming the phosphate mineral apatite). Due to this, it becomes imperative to understand alternative pathways to increase biogenically available phosphorus in environments. To that end, this dissertation involved examining olivine as an alternative source of phosphorus to apatite, analyzing a novel grain of iron silicide found via lightning reduction in a fulgurite, and finally sought to understand the impact of phosphate mining through phosphogypsum stacks. Olivine is a …

Corrosion Mitigation And Monitoring Of Bridge Tendons And Failure Forecasting Of Wastewater Force Mains, Stanley Chike Agbakansi

USF Tampa Graduate Theses and Dissertations

Corrosion remains a significant threat to civil infrastructure, resulting in costly repairsand potential structural failures. This dissertation addresses three critical aspects of corrosion: mitigation and monitoring of post-tensioned bridge tendons, and failure forecasting of wastewater force mains due to internal corrosion.

First, the research investigates the effectiveness of corrosion inhibitors (CIs) applied via pressure injection (impregnation) in post-tensioned tendons. The protective mechanisms and long-term performance of various inhibitors were evaluated to identify the most effective formulations. Among the tested inhibitors, MCI-2020 — a water-based, migratory, mixed-type corrosion inhibitor — demonstrated the most promising results, showing excellent corrosion protection while preserving …

The Synthesis Of A Photo-Affinity Probe Library For The Fatty Acid Amide Proteome And The Endocannabinoid System Within, Robert E. Feeney Iii

USF Tampa Graduate Theses and Dissertations

Fatty acid amides are a large family of endogenous metabolites with significant biological activity, including that of the endocannabinoid system. Currently little is known about how this system of tightly regulated compounds works within humans. This work lays the foundation to explore the structure-activity relationship driving the selectivity of ligand-protein interactions involved with fatty acid amides. A library of activity-based proteomic profiling probes for fatty acid amides has been synthesized to this end. Additionally, progress towards phytocannabinoid probes has been made as well.

An Exploratory Analysis Of Automated Deception Detection For Mental Health Applications, Sayde Leya King

USF Tampa Graduate Theses and Dissertations

Deception in mental health settings can undermine therapeutic relationships, compromise treatment efficacy, and impact patient outcomes. Yet, research shows that mental health clinicians often perform no better than chance at detecting deceptive behavior in therapy. Automated deception detection, leveraging artificial intelligence (AI) and multimodal behavioral cues—such as eye gaze, body gestures, and facial expressions—offers a promising alternative. However, most existing research focuses on high-stakes legal contexts, limiting its applicability to mental health settings.

This dissertation addresses this gap by pursuing three key research objectives using a mixed-methods approach. First, we investigate mental health clinicians’ perspectives on AI-assisted deception detection through …

Efficient Methods And Algorithms For Analyzing Stochastic Systems, Mohammad Ahmadi

USF Tampa Graduate Theses and Dissertations

This dissertation addresses the challenges of stochastic analysis of safety-critical systems with biological components, where unexpected behavior can lead to catastrophic events. Two fundamental challenges hinder the analysis of such systems: their typically large or infinite state spaces, and the extreme rarity of error states of interest. While Monte Carlo simulation can analyze biochemical systems without storing the state space, accurately estimating rare event probabilities becomes computationally prohibitive. Conversely, probabilistic model checking excels at analyzing extremely low probability events but becomes impractical for systems with large or infinite state spaces due to memory constraints.This work proposes two main contributions to …

Learning Analytics: An Innovative Technological Tool To Help Increase Student Retention And Graduation Rates In Us Higher Education Institutions, Fednold Thelisdort

USF Tampa Graduate Theses and Dissertations

Higher education institutions (HEIs) have embarked on a journey of innovation by adopting learning analytics (LA) in their operation, offering a more sustainable and innovative technological tool to increase student retention and graduation rates in US HEIs. LA, an emerging academic and technological tool, equips HEIs to gather, analyze, and interpret their students’ data. Since the publication of the first (conceptual) framework by Burke (2019), LA has matured into a research focus and practice, implemented in several institutional contexts at different scales and disciplinary/pedagogical contexts. This study explored the impact of the use of LA on student retention and graduation …

Isotopic Fingerprints Of The Coastal Margins: Tracing Dissolved Iron Sources From Land To Sea, Hannah R. Hunt

USF Tampa Graduate Theses and Dissertations

Dissolved iron (dFe) is an essential micronutrient for sustaining life in the surface ocean. Nearly four decades of research dedicated to understanding sources, cycling and biogeochemical modifications of Fe sources in the global oceans has generated a significant body of research supporting the idea that the concentration of Fe in the surface ocean exerts significant controls on primary production and carbon uptake in the surface ocean. Creation of the GEOTRACES program greatly increased the spatial and temporal resolution of high-quality trace element and trace element isotope data revealing new insights into the global Fe cycle, especially through the use of …

Applications Of Contracting Self-Similar Groups To Cryptography And Scale Groups, Arsalan Akram Malik

USF Tampa Graduate Theses and Dissertations

Given their peculiar properties, self-similar groups are of great interest both from applications and theoretical standpoints. In this work we study the scope of their applications in post-quantum cryptography and in constructing scale groups via lifting maps.

We propose self-similar contracting groups as a platform for cryptographic schemes based on simultaneous conjugacy search problem (SCSP). This class of groups admits fast polynomial-time algorithms for the word problem and element multiplication that can be used for effective encryption and decryption of messages. It contains extraordinary examples like the Grigorchuk group, which is known to be non-linear, thus making some of existing …

The Role Of Langmuir Circulation In Coastal Flows Driven By Wind, Waves And Tides, Thathsarani Dilini Herath Herath Mudiyanselage

USF Tampa Graduate Theses and Dissertations

Langmuir Circulation (LC) is a wind and wave-driven process and is a key driver of vertical mixing and transport in the ocean. In coastal shelf regions, LC can span the entire water column, linking surface and bottom boundary layers and amplifying turbulent mixing. However, the influence of LC on vertical mixing and cross-shelf transport in shallow, tidally forced coastal waters remains poorly understood. This dissertation addresses this knowledge gap by developing a novel modeling framework based on the Reynolds-Averaged Navier–Stokes (RANS) equations, offering a computationally efficient alternative to more resource-intensive Large Eddy Simulations (LES).

The proposed RANS-based approach is first …

On Some Hypergraph Coloring Algorithms, Boyoon Lee

USF Tampa Graduate Theses and Dissertations

Of a given bipartite graph G = (V, E), it is elementary to construct a bipartition in timeO(|V |+|E|). For a given k-graph H = H(k) with k ≥ 3 fixed, Lovász proved that deciding whether H is bipartite is NP-complete. In this thesis, we consider the average running time of this problem. For that, let B_n = (B^(k))_n be the collection (family) of all bipartite k-graphs H on the fixed vertex set [n] = {1, ...., n}. We construct, of a given H ∈ B_n, a bipartition in time averaging O(n^k) over the class B_n. We provide two proofs …

Algorithms Of Eversion: Contemporary States And Digital Sovereigns, James Libengood

USF Tampa Graduate Theses and Dissertations

The rapid development of artificial intelligence (AI), the internet of things (IoT), and digitization have pushed digital sovereignty to the top of the governance agenda in the 21st century. This notion is expanded upon in this work through seven chapters encompassing theoretical underpinnings, methodological frameworks, and real-world case studies. It shows how multinational corporations dominate digital coloniality, and how the merge of physical and digital reality or eversion poses challenges. The study compares contrasting governance approaches, such as the European Union’s General Data Protection Regulation (GDPR), geared to ethical AI and data protection, versus BRICS nations’ stance on data localization …

The Only Constant Is Change: The Role Of Genetic Diversification In Cancer And Beyond, Malgorzata Tyczynska Weh

USF Tampa Graduate Theses and Dissertations

Genetic diversification, the process by which genetic variation arises in a population, is fundamental to evolution by natural selection. Mutation, a central diversification process, fuels adaptation across species, including in cancer. Yet most new mutations are neutral or deleterious on cell fitness, raising the question of how mutation-driven adaptation persists. To explore this paradox, I developed a spatial agent-based model (ABM) in which population fitness emerges from individual cells acquiring mutations at varied rates and with diverse fitness effects. I evaluated model behavior across adaptive states, mutation rates, and distributions of fitness effects. The results show that high mutation rates …

The Epistemologization Of Scientific Knowledge: Scientific Textbooks And Education In The 18th And 19th Centuries, Brian P. Bieganski

USF Tampa Graduate Theses and Dissertations

Philosophy, despite its proclivities towards history and contextualization, often neglects to properly note various characteristics of ideas. In particular, there seems to be a kind of blindness to a key component of how ideas come into being: namely, the role of writing that leads to the preservation and transmission of ideas. Textbooks, for instance, are a key instrument for containing, disseminating, and archiving knowledge of a specific domain that can be used to introduce those complex concepts to newcomers and the unspecialized. As such, a textbook is an epistemic device used for transmitting a condensed constellation of ideas, concepts, formulas, …

An Evaluation Of Check-In/Check-Out For Children With Emotional And Behavioral Disorders, Norma E. Guillen

USF Tampa Graduate Theses and Dissertations

Children with emotional and behavioral disorders (EBD) often display disruptive behavior that can hinder their learning and negatively affect the classroom environment. Check-in/Check-Out (CICO) is a Tier-2, evidence-based intervention designed to support children who have difficulty engaging in classroom activities and are at-risk of developing more severe challenging behavior. The primary goal of the intervention is to prevent the escalation of these behaviors and reduce the need for more intensive individualized interventions. However, limited research exists on the effectiveness of CICO for children with emotional and behavioral disorders (EBD). This study examined the effects of CICO on improving on-task behavior …

Sea Turtle Nesting On Nourished Beaches With Different Construction Designs: A Case Study In Southeast Florida, Usa., Lara Novalvos Hernandez

USF Tampa Graduate Theses and Dissertations

This study examines the influences of different beach nourishment designs and subsequent post-nourishment profile adjustments on loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtles nest survival and reproductive success. Data on time-series post-nourishment beach-profile changes, positions and elevations of turtle tracks and nest/false-crawl apices, and sea turtle nest hatch/emergence success were collected on five high density nesting beaches along the east coast of Florida: Melbourne Beach, Jensen Beach, Jupiter Island Beach, Juno Beach, and South Hutchinson Island Beach. The field data collection was conducted in 2018, 2019, 2021, and 2022 with the main goal of documenting and comparing turtle …

Behavior And Land Use Of Eastern Gray Squirrels In Urban And Suburban Environments, Laura F. Engel

USF Tampa Graduate Theses and Dissertations

Urbanization has significantly altered natural habitats, impacting wildlife behavior and distribution. This study examines the behavior and land use of eastern gray squirrels (Sciurus carolinensis) in urban and suburban environments at the University of South Florida. Using a combination of point count surveys and time-activity budgets, squirrel presence was assessed in relation to tree genera, nest locations, human activity, and infrastructure. Results indicate a significant association between squirrel presence and tree genera, with a preference for Quercus species, as well as a strong positive correlation between human infrastructure and squirrel presence. However, no significant relationship was found between human presence …

Examining The Impact Of Single-Case Design Graph Characteristics On Decision-Making For School-Based Professionals Within An Mtss Context, Jessica L. Andrews

USF Tampa Graduate Theses and Dissertations

Research investigating the display of single-case design (SCD) data has demonstrated that graphing characteristics can influence visual analysis and rater interpretations regarding the effect of an intervention. Data-based decision making within school settings, particularly within the framework of Multi-Tiered Systems of Support (MTSS), commonly includes the use of SCD’s to support this process. Despite the push for adherence to a standard assembly for linear graphs, there is no requirement as to how these graphs should be constructed. MTSS team members are often required to make decisions about whether an intervention should be continued (or not), and thus it is important …

Quantifying Wellbore Effects During Co2 Sequestration In A Saline Aquifer, Uzoma Johnpaul Ajugwe

USF Tampa Graduate Theses and Dissertations

Carbon capture and storage (CCS) is a strategy for mitigating climate change by reducing greenhouse gas emissions from large stationary sources like fossil-fuel-fired power stations. One method of CCS involves carbon dioxide (CO2) sequestration in deep saline aquifers, where supercritical CO2 is injected into an aquifer. The success of such projects depends on accurate predictions of CO2 behavior within the subsurface, which are obtained through numerical simulations.

TOUGHREACT, a renowned simulation tool, models subsurface fluid flow, geochemical interactions, and solute transport, providing insights into the feasibility of CO2 sequestration projects. A critical aspect of these simulations is the apportioning of …

A Community-Based Study To Investigate Persistent Ambient Odors In Childs Park, Fl, Gennaro Saliceto

USF Tampa Graduate Theses and Dissertations

For many years, residents in Childs Park, Saint Petersburg, Florida, have reported unpleasant odors. Although there have been prior efforts to address the issue, the odors continue to be a concern for the community, who worry about possible health implications. This research aimed to equip residents with information to address the issue by identifying the presence of airborne pollutants that generate odors, quantifying the concentrations of toxic organic pollutants, and exploring the sources and environmental conditions that contribute to odors and their perception.

To accomplish these aims, the study utilized different methods. First, two walking measurement campaigns were conducted to …

Pathways To Efficient And Equitable Solutions For Large-Scale Routing Problems, Abhay Sobhanan

USF Tampa Graduate Theses and Dissertations

This dissertation addresses large-scale optimization problems in transportation emerging from hierarchical decision-making, equitable workload allocation, and innovative routing logistics. It presents three sets of contributions, each detailed in a separate chapter, and offers computational tools and insights to advance both the theory and practice of transportation systems.

The first work introduces a deep learning-enhanced genetic algorithm framework for solving the Hierarchical Vehicle Routing Problems (HVRPs). Traditional optimization approaches to such problems require extensive evaluation of multiple lower-level routing solutions and are computationally intensive. Our innovative method integrates a genetic algorithm with a pretrained graph neural network, which is trained on …

Simulation Of Multi-Receiver Solar Power Tower By Enhancement Of Solarpilot Software And A Review Of Absorber Coating Materials For The Receivers, Yasser Mirza Baig

USF Tampa Graduate Theses and Dissertations

Central receiver concentrating solar power (CSP) towers offer significant potential for cost-effective renewable electricity but face increasing optical losses with larger heliostat fields. This thesis introduces enhancements to NREL’s SolarPILOT software through a Python-based API named CoPylot, which enables comprehensive optimization of heliostat field layouts for multi-receiver systems. The enhanced methodology incorporates per-heliostat ray tracing, receiver orientation optimization (tilt angle β), and an incidence-angle-dependent absorptance (α(θ)) model to evaluate optical performance, thermal losses, and techno-economic metrics within an integrated simulation framework.

A case study for Daggett, California demonstrates that transitioning from a baseline single-receiver system (180 m tower, 5×5 m …

Development And Photophysical Characterization Of Bioinspired Materials, Qaisar Maqbool

USF Tampa Graduate Theses and Dissertations

Porphyrins are versatile aromatic macrocycles with unique photophysical properties that make them attractive for applications in light harvesting, photocatalysis, and sustainable energy conversion. Incorporating porphyrins into metal-organic frameworks (MOFs) offers a unique opportunity to modulate their photophysical behavior through spatial confinement and host–guest interactions. This thesis explores how structural modifications influence porphyrin excited-state behavior through a multi-stage investigation. The work begins by comparing the photophysical properties of two cationic porphyrins: tetra(N-methylpyridyl) porphyrin(TMPyP) and tetra(4-N,N,N-trimethylanilinium) porphyrin(4TANP). While TMPyP exhibits significant singlet–charge transfer (S₁–CT) state mixing due to charge delocalization onto peripheral pyridinium groups, 4TANP lacks comparable behavior. The localized nature of …