Digital Commons Network^™

Biomaterials: From Scaffold Design To Implant Optimization, Jennifer Marie Armen

Electronic Theses and Dissertations

This work encompasses three individual projects concerning biomaterials and their modifications. Chemically-Induced Cross-Linking of Peptidic Fibrils for Scaffolding Polymeric Particles and Macrophages EAK16-II (EAK) is a self-assembling peptide (SAP) that forms β-sheets and βfibrils through ionic-complementary interactions at physiological ionic strengths. The soft materials can be injected in vivo, creating depots of drugs and cells for rendering pharmacological and biological actions. The scope of the applications of EAK is sought to extend to tissues through which the flow of extracellular fluid tends to be limited. In such anatomical locales the rate and extent of the fibrilization are limited insofar as …

Turbulent Transport Of Dissolved Oxygen In Natural Channels, Alanna Bachtlin

Electronic Theses and Dissertations

The transport and mixing of dissolved oxygen (DO) is important to replenish the oxygen depleted by natural processes; gas transfer in general has implications for ecosystem metabolism and greenhouse gas transfer. Currently, reaeration coefficients can be found through gas tracer methods, which estimates one-way gas transfer. For this project, a net oxygen consumption rate, , was developed using the similarity equations, which provides a value from DO and velocity profiles specific to a stream site. Additionally, three models to calculate friction velocity, which is required for oxygen consumption rate, were compared. Reynolds stresses, mathematically developed in the Reynolds-Averaged Navier-Stokes Equations, …

The Contribution Of Ethical Governance Of Artificial Intelligence & Machine Learning In Healthcare, Tina Nguyen

Electronic Theses and Dissertations

With the Internet Age and technology progressively advancing every year, the usage of Artificial Intelligence (AI) along with Machine Learning (ML) algorithms has only increased since its introduction to society. Specifically, in the healthcare field, AI/ML has proven to its end-users how beneficial its assistance has been. However, despite its effectiveness and efficiencies, AI/ML has also been under scrutiny due to its unethical outcomes. As a result of this, two polarizing views are typically debated when discussing AI/ML. One side believes that AI/ML usage should continue regardless of its unsureness, while the other side argues that this technology is too …

C-H On The Oxo Ferryl Wheel: Comparison Of Pyridine And Imidazole-Substituted Ligands For C-H Activation And Functionalization, Elizabeth Milem

Electronic Theses and Dissertations

The selective and efficient transformation of hydrocarbon feedstocks is of high value for industry and research. While Shilov-type organometallic methods have facilitated this goal, systems designed after nature’s use of cheap and abundant iron-based enzymes are desired for wider-scale applications. This work establishes hydrocarbon oxidation efficiency of synthetic pyridine-based ligands (BPMEN, BPMPN) compared to commercially available TPA with in situ generated catalysts. Literature studies of traditionally synthesized BPMEN systems and initial in situ studies offered evidence for enhanced reactivity (TON) as compared to TPA. Expansion to a propyl backbone to produce BPMPN tested the increased chelate ring size’s impact on …

Teaching During Covid-19: The Lived Experiences Of Title I Educators Transitioning From Face-To-Face Instruction To Remote Instruction, Nicole Boykins

Electronic Theses and Dissertations

The purpose of this study was to investigate how school closures resulting from the COVID-19 pandemic impacted school educators who teach in Title I schools serving minority students located in a southern region of the United States. Due to the swift nature of the COVID-19 pandemic and the massive impact on many communities’ health and well-being, government officials moved quickly to close schools. Teachers, much like everyone else, had little voice in the launch of remote learning, expectations of remote teaching, or how to best support students and families during a global pandemic. Educators had to rely on their skills …

An Application Of Differential Mathematical Modeling Techniques To Study The Ongoing Rabies Epizootic In China, Christopher Turner

Electronic Theses and Dissertations

Rabies remains a global public health issue with a wide variety of neurological symptoms such as confusion, slight paralysis, hypersalivation, and hydrophobia. Rabies is usually fatal once symptoms appear. Many species are reservoirs for rabies, such as foxes, racoons, and wild dogs, which in turn can transmit the disease to humans, leading to complex transmission chains. There is a long latent period of rabies, between 1 to 3 months after infection, which further complicates control efforts. Mathematical modeling is a valuable tool in the study of infectious disease outbreaks and there have been many models applied to rabies outbreaks. However, …

Disorienting Object Oriented Ontology: Queer Landscapes And Ecological Bodies In Richard Siken And Harryette Mullen., Andrew N. Hutto

Electronic Theses and Dissertations

This thesis focuses on a recent development within the study of metaphysics, known as object oriented ontology (OOO), and works out questions of being alongside contemporary poetry. Recognizing the post anthropocentric purchase afforded by OOO’s claim that everything is an object and that these objects are impossible to correlate with, this thesis will look at the use of objects in Richard Siken’s War of the Foxes and Harryette Mullen’s Recyclopedia. Drawing heavily from Sara Ahmed’s queer theory of disoriented objects and Timothy Morton’s ecological insights, this thesis will argue that despite OOO’s advancement, there are critical gaps to fill in …

2d Materials Based Heterostructure For Quantum Tunneling: A Lithography Free Technique., Ali Alzahrani

Electronic Theses and Dissertations

Two-dimensional electron gas (2DEG) systems have played a vital role in the development of superior electronic devices including tunnel junctions consisting of two such 2DEG systems. With the advent of the new 2D electronic material systems, it has opened a new route for 2D–2D tunneling in such extended systems. In this study, we have utilized a plasma enhanced chemical vapor deposition (PECVD) technique to directly deposit graphene (nanowalls) and h-BN on Si/SiO₂ substrates to construct two-dimensional material based, vertically stacked electron tunneling devices free of expensive and cumbersome microfabrication steps. In the first study, we fabricated direct quantum tunneling …

Hybrid Machine And Deep Learning-Based Cyberattack Detection And Classification In Smart Grid Networks, Adedayo Aribisala

Electronic Theses and Dissertations

Power grids have rapidly evolved into Smart grids and are heavily dependent on Supervisory Control and Data Acquisition (SCADA) systems for monitoring and control. However, this evolution increases the susceptibility of the remote (VMs, VPNs) and physical interfaces (sensors, PMUs LAN, WAN, sub-stations power lines, and smart meters) to sophisticated cyberattacks. The continuous supply of power is critical to power generation plants, power grids, industrial grids, and nuclear grids; the halt to global power could have a devastating effect on the economy's critical infrastructures and human life.

Machine Learning and Deep Learning-based cyberattack detection modeling have yielded promising results when …

Utilizing Shockwave Theory And Deep Learning To Estimate Intersection Traffic Flow And Queue Length Based On Connected Vehicle Data., Abdulmaged Algomaiah

Electronic Theses and Dissertations

The development of Connected Vehicles (CV) facilitates the use of trajectory data to estimate queue length and traffic volume at signalized intersections. The previously proposed models involved additional information that may require conducting different types of data collection. Also, most models need higher market penetration rate or more than a vehicle per cycle to provide adequate estimation. This is mainly because a significant number of the estimation models utilized only queued vehicles. However, the state of motion in non-queued vehicles, particularly slowed-down vehicles, provides much information about the traffic characteristics. There is a lack of exploiting the information from slowed-down …

Data Linkage For Crash-Injury Outcome Assessment., Aryan Hosseinzadeh

Electronic Theses and Dissertations

Introduction: Traffic crash reports lack detailed information about emergency medical service (EMS) responses, the injuries, and the associated treatments, limiting the ability of safety analysts to account for that information. Integrating data from other sources can enable a better understanding of the characteristics of serious crashes and further explain variance in injury outcomes. In this thesis, first, a heuristic approach is proposed and implemented to link crash data to EMS run data, patient care reports, and trauma registry data. Next, the method was adapted through larger datasets in a statewide linkage effort. The performance of the heuristic method was compared …

Beyond Accuracy In Machine Learning., Aneseh Alvanpour

Electronic Theses and Dissertations

Machine Learning (ML) algorithms are widely used in our daily lives. The need to increase the accuracy of ML models has led to building increasingly powerful and complex algorithms known as black-box models which do not provide any explanations about the reasons behind their output. On the other hand, there are white-box ML models which are inherently interpretable while having lower accuracy compared to black-box models. To have a productive and practical algorithmic decision system, precise predictions may not be sufficient. The system may need to have transparency and be able to provide explanations, especially in applications with safety-critical contexts …

Spectroscopic Measurements Of Meibum Compositional, Structural, And Functional Relationships To Elucidate The Role Of Meibum In Dry Eye., Anthony Chigozie Ewurum

Electronic Theses and Dissertations

The major aim of my dissertation was to investigate the etiology of dry eye disease which affects about 7 million people in the United States, causing symptoms that can lead to visual disturbance. Correlation between dry eye and an abnormal lipid layer of the tear film has been found. Tear film lipids originate mostly from the meibomian glands. Cholesteryl ester (CE) and Wax ester (WE) lipids make up most of the human meibum lipidome and the CE/WE ratio has been shown to decrease in patients with meibomian gland dysfunction. Model studies using synthetic CE and WE, although providing some insight, …

Modeling And Debiasing Feedback Loops In Collaborative Filtering Recommender Systems., Sami Khenissi

Electronic Theses and Dissertations

Artificial Intelligence (AI)-driven recommender systems have been gaining increasing ubiquity and influence in our daily lives, especially during time spent online on the World Wide Web or smart devices. The influence of recommender systems on who and what we can find and discover, our choices, and our behavior, has thus never been more concrete. AI can now predict and anticipate, with varying degrees of accuracy, the news article we will read, the music we will listen to, the movies we will watch, the transactions we will make, the restaurants we will eat in, the online courses we will be interested …

Statistical Methods For Assessing Drug Interactions And Identifying Effect Modifiers Using Observational Data., Qian Xu

Electronic Theses and Dissertations

This dissertation consists of three projects related to causal inference based on observational data. In the first project, we propose a double robust to identify the effect modifiers and estimate optimal treatment. Observational studies differ from experimental studies in that assignment of subjects to treatments is not randomized but rather occurs due to natural mechanisms, which are usually hidden from the researchers. Many statistical methods to identify the treatment effect and select the optimal personalized treatment for experimental studies may not be suitable for observational studies any more. In this project, we propose a exible outcome model to select the …

Surface-Functionalized Chemiresistive Films That Exploit H-Bonding, Cation-Pi, And Metal-Halide Interactions., Prasadanie Karunarathna Adhihetty

Electronic Theses and Dissertations

The development of gas sensors for detection of volatile organic compounds (VOCs) has been of interest in the sensing field for decades. To date, the use of metal nanoparticle-based chemiresistors for trace VOC detection, particularly gold nanoparticle-based sensors, is of great interest due to their high chemical stability, ease of synthesis, unique optical properties, large surface to volume ratio, and high level of conductivity. Much effort has been devoted towards gold monolayer protected clusters (Au MPCs) as chemiresistors to detect harmful VOCs. The present thesis documents the results of our efforts to exploit the advantages of functionalized Au MPCs chemiresistors …

Structural, Charge Transport, Gas Sensing, Magnetic, Pseudocapacitive, And Electrocatalytic Properties Of Perovskite Oxides., Surendra Bahadur Karki

Electronic Theses and Dissertations

Perovskites are functional materials with the general formula ABO₃ (A = alkali, alkaline earth or lanthanoid cations and B = transition metal or main group cations). These materials are marked by a variety of crystal structures and interesting properties such as colossal magnetoresistance, ferroelectricity, multiferroicity, superconductivity, pseudocapacitance, gas sensing, charge transport, and electrocatalytic properties. The formula of perovskite can be written as AA’BB’O₆, when there is ordering between two cations over A and B-sites. Such compounds are called double perovskite oxides. Some amount of oxygen could be lost from crystal structure without decomposition of the phase. Such …

A Modeling Platform To Predict Cancer Survival And Therapy Outcomes Using Tumor Tissue Derived Metabolomics Data., Hunter Allan Miller

Electronic Theses and Dissertations

Cancer is a complex and broad disease that is challenging to treat, partially due to the vast molecular heterogeneity among patients even within the same subtype. Currently, no reliable method exists to determine which potential first-line therapy would be most effective for a specific patient, as randomized clinical trials have concluded that no single regimen may be significantly more effective than others. One ongoing challenge in the field of oncology is the search for personalization of cancer treatment based on patient data. With an interdisciplinary approach, we show that tumor-tissue derived metabolomics data is capable of predicting clinical response to …

Development And Novel Applications Of Halogenating Agents., Sagar Ravso Mudshinge

Electronic Theses and Dissertations

Organic halides are extensively utilized as synthetic intermediates in areas such as pharmaceuticals, agrochemicals, and material polymers. While many halogenating agents have been developed, they continue to have low efficiency or selectivity, are difficult to handle, and often have limited substrate scope. To address this issue, our laboratory has developed novel halogenating agents with improved stability and efficiency. In these studies, we demonstrated a novel application of halogenating reagent, HCl·DMPU, in the nitrile synthesis. We developed a novel method for C−SCF₃/SeCF₃ cross-coupling reactions using gold redox catalysis. We developed a novel trifluoromethylating agent in a cost-effective and …

Nucleate Boiling Under Different Gravity Values: Numerical Simulations & Data-Driven Techniques., Sandipan Banerjee

Electronic Theses and Dissertations

Nucleate boiling is important in nuclear applications and cooling applications under earth gravity conditions. Under reduced gravity or microgravity environment, it is significant too, especially in space exploration applications. Although multiple studies have been performed on nucleate boiling, the effect of gravity on nucleate boiling is not well understood. This dissertation primarily deals with numerical simulations of nucleate boiling using an adaptive Moment-of-Fluid (MoF) method for a single vapor bubble (water vapor or Perfluoro-n-hexane) in saturated liquid for different gravity levels. Results concerning the growth rate of the bubble, specifically the departure diameter and departure time have been provided. The …

Sustainable Nanocatalysis In Water For C–C And C–N Cross-Couplings., Tharique Ahammed Ansari Nalakath

Electronic Theses and Dissertations

The development and application of various micelle-enabled nanopalladium-catalyzed organic transformations are discussed in this dissertation. These methodologies primarily harness the “micellar effect” imparted by the custom-designed amphiphile PS-750-M. Modern spectroscopic and imaging techniques were employed to systematically study the metal-micelle interactions and answer the fundamental questions regarding the operational nature of micellar catalysis. Chapter 1 reviews the history and evolution of organic synthesis, providing a critical outlook regarding the alarming inefficiency of contemporary synthetic practices indicating an inevitable transition to more sustainable synthetic techniques. In this context, the development of micellar catalysis is discussed, emphasizing its basic principles, applications, and …

Coping Flexibility And Academic Resilience Among Low-Ses College Students., Benjamin J. Calebs

Electronic Theses and Dissertations

College students coming from a background of poverty may experience academic impairment due to their experiences of chronic economic adversity. However, despite the stressors associated with poverty and the potential deleterious consequences of this form of adversity, many low-socioeconomic status (low-SES) college students show high academic achievement. One predictor of resilient outcomes that has been studied outside of academic contexts is coping flexibility, the ability to use a range of different coping behaviors to meet the demands of different stressful situations. Coping flexibility has been found to be positively associated with psychological adjustment in a variety of populations, yet it …

Clickbait., Roger Knight

Electronic Theses and Dissertations

Clickbait is a surround-sound, audio, video, and audience participation work for live electronics that connects its listeners to the music through the use of a variety of interconnected technologies. The topic of internet clickbait was the initial inspiration that grew into a personal and cultural question. Technological mechanics of live web-based services and data-mining informed those themes further. The interactive nature of internet clickbait drove efforts to establish a deeper connection between the audience and the music. To develop connections between people, applications, and the piece, Node.js, Google Cloud Services, VoiceRSS, and Max/MSP/Jitter video tools were used. This underpins a …

Small-Scale Variability In Warm Season, Precipitation Around An Urban Area: A Case Study Of Louisville-Jefferson County, Ky., Isaiah I. Kingsberry

Electronic Theses and Dissertations

Numerous studies have detected anomalous precipitation patterns occurring up to 50 km downwind of major cities, providing major evidence that cities inadvertently modify precipitation and atmospheric circulations. Louisville is one such major city with a growing body of evidence of inadvertent precipitation modification. Despite these efforts, the physical mechanisms driving small-scale and unintentional changes in urban precipitation are little understood, being rooted largely in theory rather than in physical observations. This study seeks to build upon previous research by analyzing ground-based precipitation observations recorded by a high-density gauge network located within approximately 40 km of Louisville’s urban center. The results …

Beyond A Divide: Reconceptualizing Digital Capital And Links To Academic Proficiency., Ryan Price

Electronic Theses and Dissertations

In the digital inequality literature, the popular notion of a “digital divide” is frequently used to discuss digital inequality; however, this framework is overly simplistic and cannot adequately capture the complex nature of digital inequality. Some scholars have adopted a framework of digital capital to attempt a multidimensional approach to this social problem, but the literature lacks consistent empirical measurements. Using U.S. data from the Programme for International Student Assessment (PISA) 2018 Survey, I seek to propose, and validate, internally consistent principal components of digital capital among 15-year-old high school students in the US. I conduct a Principal Component Analysis …

A Mesonet-Based Analysis Of Severe Convective Winds In West Texas., Quint Long

Electronic Theses and Dissertations

Multiple studies have investigated the occurrence of severe convective-related winds and have increased our understanding of the forces driving severe winds and their spatial and temporal patterns. Data for these studies have come from airport stations maintained by the National Weather Service. Their standardization across the United States makes them ideal for research, but they are limited in their distribution. This study aims to create a similar climatology of severe surface level winds using a mesoscale network (“mesonet”). Like their ASOS (Automated Surface Observing System) and AWOS (Automated Weather Observing System) counterparts, these stations are standardized and well maintained. This …

Automatic Testing Of Organic Strain Gauge Tactile Sensors., Brian P. Goulet

Electronic Theses and Dissertations

Human-Robot Interaction is a developing field of science, that is posed to augment everything we do in life. Skin sensors that can detect touch, temperature, distance, and other physical interaction parameters at the human-robot interface are very important to enhancing the collaboration between humans and machines. As such, these sensors must be efficiently tested and characterized to give accurate feedback from the sensor to the robot. The objective of this work is to create a diversified software testing suite that removes as much human intervention as possible. The tests and methodology discussed here provide multiple realistic scenarios that the sensors …

New Debiasing Strategies In Collaborative Filtering Recommender Systems: Modeling User Conformity, Multiple Biases, And Causality., Mariem Boujelbene

Electronic Theses and Dissertations

Recommender Systems are widely used to personalize the user experience in a diverse set of online applications ranging from e-commerce and education to social media and online entertainment. These State of the Art AI systems can suffer from several biases that may occur at different stages of the recommendation life-cycle. For instance, using biased data to train recommendation models may lead to several issues, such as the discrepancy between online and offline evaluation, decreasing the recommendation performance, and hurting the user experience. Bias can occur during the data collection stage where the data inherits the user-item interaction biases, such as …

New Accurate, Explainable, And Unbiased Machine Learning Models For Recommendation With Implicit Feedback., Khalil Damak

Electronic Theses and Dissertations

Recommender systems have become ubiquitous Artificial Intelligence (AI) tools that play an important role in filtering online information in our daily lives. Whether we are shopping, browsing movies, or listening to music online, AI recommender systems are working behind the scene to provide us with curated and personalized content, that has been predicted to be relevant to our interest. The increasing prevalence of recommender systems has challenged researchers to develop powerful algorithms that can deliver recommendations with increasing accuracy. In addition to the predictive accuracy of recommender systems, recent research has also started paying attention to their fairness, in particular …

The Water We Were Swimming In: Transgender And Gender Nonconforming Students' Lived Experiences In Engineering., Natalie Saroff Oliner

Electronic Theses and Dissertations

Few studies address the lived experiences of transgender and gender nonconforming (TGNC) students in engineering. Grounded in critical trans politics (Spade, 2015), this dissertation contributes to the literature on TGNC students in engineering by examining their experiences negotiating their identities while navigating interrelated systems of oppression in a field dominated by White, heterosexual, cisgender men. Using a critical constructivism framework, I conducted a narrative inquiry to explore the lived experiences of five TGNC students in engineering programs. Participants experienced TGNC oppression at their universities, built LGBTQ+ and TGNC communities, and described more welcoming climates in non-engineering contexts compared to engineering. …