Digital Commons Network^™

Autonomous Corrosion Detection In Steel Structures Using Different Non-Contact Techniques, Amrita Das

Theses and Dissertations

Metallic corrosion is an electrochemical process that can occur due to the formation of aqueous adlayers on the metal surface. It is often described as reverse metallurgy, as corrosion drives refined metals back to their lowest energy state, namely an oxidized, ore-like form. Environmental factors that promote corrosion include precipitation, high humidity, and chemical condensation, which can result from the hygroscopic nature of pollutants deposited on the surface. There is a significant impact of metallic corrosion on the U. S. economy including infrastructure, transportation, utilities, production, and manufacturing. The total direct cost of corrosion in the United States has been …

Gender-Based Perceptions Of Confronting Prejudice In The Classroom, Mary Hamilton

Theses and Dissertations

Disparities exist between men and women in academia at the faculty and student level. Academically, women are judged as being weaker and inferior, and many describe experiences of sexism, often within the classroom setting. Few studies have investigated the impact of an instructor confronting sexism in the classroom. The current study examined the effects of an instructor’s gender, student’s gender, and instructor’s confrontation decision on students’ perceptions of the instructor, classroom environment, and the moderating effect of self-reported sexism. Participants read one of four vignettes describing an act of sexism in the classroom where a male (or female) instructor confronts …

Belongingness And Science Identity Of Underrepresented Students In Aerospace Sciences, Bella Hettich

Theses and Dissertations

Despite efforts to support underrepresented individuals—specifically those from racial, ethnic, and gender minority groups—they continue to face unique challenges that affect their belongingness in aerospace sciences, leading to issues with retention in educational programs and subsequent professional pathways. Such hindrances to personal achievement can also impede broader organizational goals. Addressing these challenges is critical, as supporting the success of underrepresented individuals fosters diverse perspectives, which are essential for driving innovation and maximizing organizational productivity. Just as importantly, ensuring that every individual, regardless of background, has access to opportunities and the support needed to succeed fulfills an ethical obligation. Upholding the …

Thermally Induced Evolution Of The Cement Microannulus In Co2 Injection Wells, Jawad Ali Khan

Theses and Dissertations

Ensuring wellbore integrity during CO₂ injection is a critical challenge in Carbon Capture and Storage (CCS), as failures at the casing-cement and cement-formation interfaces can create potential leakage pathways. This dissertation presents a multi-scale, physics-based investigation into well integrity risks, integrating finite element analysis (FEA), thermal-mechanical-poroelastic modeling, and transient stress analysis to evaluate cement sheath stability, fracture-driven stress localization, and microannulus formation under various CCS conditions.

A key novelty of this research is the development of a fully coupled thermal-mechanical-poroelastic FEA framework using COMSOL Multiphysics, a renowned industry-standard software for multiphysics simulations. This model enables a dynamic, time-dependent assessment …

A Federated Learning Solution For Secure And Scalable Edge Computing In Distributed Environments, Muhammad Hamza Karim

Theses and Dissertations

The growing penetration of Distributed Energy Resources (DERs) into the modern power system has introduced significant challenges related to data volume and cybersecurity. Centralized approaches struggle to process the large volume of data generated by inverters or other DER-related assets securely and efficiently. This problem raise concerns about the confidentiality, integrity, availability, and accountability (CIAA) properties of DER assets. Moreover, the large deployment of Internet of Things (IoT) and edge computing devices has introduced new security vulnerabilities. Malicious actors can exploit resource-constrained edge devices for unauthorized activities and resource consumption, threatening the performance and operational capabilities of the edge infrastructure. …

Thresholds In Modular Lattices, Daniel Atta Kwakye

Theses and Dissertations

This study investigates threshold phenomena in infinite modular lattices, extending classical threshold theory beyond Boolean and distributive lattice settings. Specifically, let\(P\) be a finite graded modular lattice with a finite graded modular lattice with rank function \(r: P \rightarrow \mathbb {N}\). By adapting probabilistic combinational methods, notably the methods used by Janson, Łuczak, and Ruciński (2011), we establish rigorously that every monotone property \(F\subseteq P\) possesses a threshold under the chain-uniform random model.Formally, this threshold is characterized by a critical rank \(M^*\), at which the probability \(\mathbb{P}(\Gamma_M\in F)\) transitions sharply from nearly 0 to nearly 1 as the parameter \(M\) …

Investigation In Using Kinesthetic Learning Of Electricity And Magnetism In Scale-Up, Joseph Charley Langenwalter

Theses and Dissertations

This study investigates the effectiveness of incorporating kinesthetic learning activities into a SCALE-UP (Student-Centered Active Learning Environment with Upside-down Pedagogies) physics course to improve students' conceptual understanding of electricity and magnetism. This study aims to explore the effects of adding kinesthetic activities to a first-year 2nd semester physics course on student learning that included 92 students in three groups, traditional, scale-up control, scale-up activity classrooms. Nine active learning activities were designed to promote learning. A unique pre-post instrument was used to gauge student learning. Three questions from an instrument showed statistically significant improvement in student scores from the semester that …

The Role Of Student Loan Debt On Delayed Homeownership Among Black American College Graduates, Dedan Makongoro Kusaga

Theses and Dissertations

The growing burden of student loan debt in the United States has raised significant concerns about its broader social and economic impacts, particularly on young adults’ ability to achieve financial milestones such as homeownership. Black American college graduates are especially affected, often carrying higher loan balances and facing greater financial barriers due to historical and structural inequalities. This quantitative study examined the role of student loan debt and other factors influencing delayed homeownership among Black American college graduates, using the public-use Baccalaureate and Beyond (B&B: 2008/2018) dataset from the National Center for Education Statistics (NCES). Findings indicated student loan debt, …

Creating Equitable Employment Practices For Adjunct Faculty: Perceptions Of Academic Administrators At Public Institutions In A Great Plains State, Constance Mciver

Theses and Dissertations

Adjunct faculty are a substantial feature of the higher education classroom. Their increased prevalence has contributed to elevated concerns regarding the employment practices of these part-time faculty. While numerous published accounts of adjunct faculty experiences are available, recorded perceptions of academic administrators are less prevalent. Eighty-six academic administrators from six public universities in a Great Plains state participated in a researcher-developed survey to determine the expectations placed upon and compensation practices for adjunct faculty, as well as perceptions of the strengths and weaknesses of the adjunct system and the feasibility of providing more equitable compensation. Survey findings suggest there is …

Stem Professors’ Motivation To Engage In A College Teaching Certificate, Justin Craig Alexander

Theses and Dissertations

Despite an expanded focus on educating students in STEM disciplines, nearly half of U.S. college students who enroll in these degree programs fail to graduate (Hamm et al., 2020, p. 623). Critics sometimes blame pedagogically untrained faculty (e.g., Kahn, 2022). This Dissertation in Practice (DiP) focused on STEM university faculty's motivation for teaching and whether professors are motivated to enroll in pedagogy courses. Via the lens of self-determination theory (SDT), this DiP examined to what extent STEM faculty at a major research university in the upper Midwest could devote additional time to pedagogy by enrolling in a college teaching graduate …

Exploring The Experiences Of First-Year Pre-Nursing Students’ Sense Of Belonging In A Living-Learning Community And First-Year Seminar, Robyn Bancroft

Theses and Dissertations

Many factors may influence how a student experiences their first year adjusting to college life. The University of North Dakota, a public research institution located in Grand Forks, ND, recently implemented a nursing living-learning community (LLC) comprised of first-year, pre-nursing students, which also required the students to take a one-credit first-year seminar (FYS) together, known as UNIV 101 – Introduction to University Life. A total of 10 participants who resided within this living-learning community for a minimum of one academic year and were enrolled in the same section of UNIV 101 during their first semester submitted reflection papers. Additionally, eight …

Precipitation Forecast And Verification For Suas Applications, Patrick Britt

Theses and Dissertations

Small Unmanned Aerial Systems (sUAS) have become a fast-growing part of air traffic in the United States. This significant growth is due to the numerous uses these systems can provide, both recreationally and professionally. Due to the small nature of the sUAS, any weather, regardless of intensity, plays a vital role in flight operations and planning. In a survey of sUAS pilots, it was found that precipitation was the most significant hazard of concern, and the most time-sensitive hazard, as precipitation conditions are most often checked by operators in the immediate moments before flight. This project aimed to create, analyze, …

Predictive Modeling For Multiphase Flow Boiling Heat Transfer By Integrating Computational Fluid Dynamics And Machine Learning Approaches, Mohamed Elfaham

Theses and Dissertations

The heat transfer process in multiphase flow systems becomes essential forindustrial applications and when phase change occurs. The heat transfer coefficients become more efficient during boiling and condensation processes when compared to single-phase fluid flow. The design of thermal systems requires knowledge about these coefficients together with their essential parameters. This study evaluates flow boiling heat transfer coefficients for low-global warming potential refrigerants which include pure ethanol and propane (R-290) and R- 600 and R-600A. The experimental database included more than 25 independent studies that covered various operating conditions and channel sizes and fluid properties. Existing empirical correlations were evaluated, …

Computational Prediction Of Hemolysis In Laminar Non-Newtonian Fluid, Nasim Gholizadeh

Theses and Dissertations

Hemolysis, the rupture of red blood cells (RBCs), is a critical concern in blood-circulating devices, requiring accurate predictions to ensure patient safety. This study investigates the sensitivity of hemolysis predictions to variations in viscosity models and hemolysis coefficients under complex flow conditions. Computational Fluid Dynamics (CFD) simulations were conducted using Ansys Fluent and OpenFoam on identical meshes with the FDA benchmark nozzle model. Under laminar flow conditions, CFD frameworks accurately predicted global variables, but variations in derived quantities, such as strain rate and vorticity, emerged due to differences in numerical solvers and gradient evaluation methods. These variations affected predictions of …

Beyond All Possible Doubt? The Shifting Of A Juror’S Conviction Threshold In Criminal Cases Based On Charge, Sentence, And Evidence, Sophie Johnson

Theses and Dissertations

In criminal trials, jurors must make a decision that will forever change the defendant’s life (Couloute & Kopf, 2018), during which jurors may consider the impact that not convicting a guilty person may have (i.e., Type II error) or if the charge is worth the crime regardless of the defendant’s guilt (i.e., Type I error). Jurors may raise their conviction thresholds if they feel a type II error is favorable to a type I error. Researchers have discovered that in cases where charge severity (e.g., Kerr, 1978) or the perceived sentence (e.g., Kaplan & Krupa, 1986) is higher, jurors shift …

Impact Of Resin Grinding On Per- And Polyfluoroalkyl Substance Adsorption In Rapid Small-Scale Column Tests, Tihitna Gezahegn Mulugeta

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with significant health risks. Among the different technologies for PFAS removal, adsorption is preferable due to low-cost, operational simplicity, and use of regenerable adsorbents. While pilot-scale fixed-bed columns are ideal for evaluating adsorption media, they are time- and resource-intensive. Rapid Small-Scale Column Tests (RSSCTs) offer a practical alternative, yet most studies have focused on granular activated carbon, with limited insight into ion exchange (IX) resins. Due to limited literature on the effect resin preparation on the performance of RSSCTs and their prediction accuracies are unexplored. This study investigates the effect of …

Using Machine Learning To Investigate Weather Impacts On Crop Yield For Probabilistic, Climate-Informed Predictive Crop Breeding, Levi Newell

Theses and Dissertations

As the world’s population continues to grow, the importance of food security willonly continue to increase, with some estimates requiring a global increase in food production between 59 and 98% by 2050. The agriculture industry is also a crucial economic driver, with the industry supporting 20% of the state of North Dakota’s workforce, and with a total valuation of $41.3 billion. The economic importance of this industry and the challenges of future growth prompt a need for data driven decision making into the future, particularly with predictive crop breeding. This is the method by which crops are developed that are …

Advancing Human-Computer Interaction Systems Through Explainable And Secure Ai Integration, Ifiok Udoidiok

Theses and Dissertations

As artificial intelligence (AI) systems increasingly shape how humans interact with digital environments, the need for transparency, security, and robustness in intelligent decision making has become critical. This thesis explores how explainable and secure AI techniques can be integrated into modern human-computer interaction (HCI) systems to enhance trust, resilience, and alignment with human operators.

We present three related studies, each addressing a distinct challenge in the design of human-centered AI. First, we apply XAI methods, specifically Local Interpretable Model-Agnostic Explanations (LIME), to deep learning (DL) based CAPTCHA solvers. By interpreting model attention patterns, we uncover exploitable weaknesses in text CAPTCHA …

Teacher Skills Needed For Effective Participation In Multi-Tiered Systems Of Support (Mtss): A State Framework Analysis, Melissa Osborne

Theses and Dissertations

This study is a secondary data analysis that uses a validated rubric to score the degree of alignment between the teacher skills (TS) necessary for the effective implementation of Multi-Tiered Systems of Support (MTSS) and the preservice teacher training standards (PTS) across five states located in the North Central United States. This investigation also assessed whether states employing an MTSS process to establish special education eligibility for specific learning disabilities (SLD) exhibit higher alignment between TS and PTS compared to states that do not follow that process. Literature outlines the TS needed in an MTSS framework, but there is limited …

Adaptblur: Adaptive Linear Filter For Enhanced Deep Learning Classification Performance, Ganesha Thondilege

Theses and Dissertations

Image preprocessing is crucial in deep learning models for high performance and accuracy. This study implements AdaptBlur, a dynamic linear filter developed from a second-order partial differential equation using finite difference approximations, which enhances image quality while preserving the image structure with dynamic parameters that are optimized through the Nelder-Mead optimization, minimizing mean square error to improve the effectiveness of the filter. Moreover, the study evaluates the impact of the results on model performance on deep learning classification using publicly available datasets. Experimentally, image classifiers trained on preprocessed data with the AdaptBlur filter perform much better than those trained without …

Addressing The Impact Of Unlicensed And Under-Licensed Teachers In Pk-12 Schools: How School Administrators Offer Support, Taylor Topinka

Theses and Dissertations

As the impact of the teacher shortage grows, more teachers are entering classrooms with incomplete teacher licensure. Related literature affirms that new-to-profession teachers experience what Danielson (1999) described as a “sink or swim in the deep end of the pool” culture as they attempt to navigate the beginning of their teaching career with an incomplete license or no license entirely (p. 251). The influx of partially-licensed teachers engaging students is a dilemma created by the growth of the teacher shortage. The purpose of this study was to address the impact of unlicensed and under-licensed teachers on student growth and achievement …

Forceful Functors: A Categorical Approach To Constraint Monitoring In Machine Learning Models, Jonathan Wirkkala

Theses and Dissertations

Often times in machine learning there are several heuristic choices that one makes during model selection, training, and validation. These choices include the type of training used, the width and depth of the model, type activation function and many more. These choices are general rules of thumb and best practices when creating a machine learning algorithm to achieve acceptable results. For example, in the case of image processing, this may mean determining whether or not a given image contains a tumor. Decisions made during the design process create several variations of machine learning algorithms, all with various properties with pros …

Investigating Teacher Leadership: A Phenomenological Study On Improving Teacher Efficacy Through Peer Coaching And Mentorship, Orlando Worges

Theses and Dissertations

This study investigates the roles of teacher leadership in enhancing teacher efficacy through mentorship and peer coaching. It examines the impact of these programs in educational settings, providing insights into their effects on efficacy. Using a phenomenological approach, in-depth interviews were conducted with mentors, administrators, and participating teachers, revealing perspectives on the strengths, weaknesses, and suggestions for improvement of the program. Thematic analysis of the data offered comprehensive insights into the experiences of participants. The findings highlight the important role of mentorship and peer coaching in enhancing teacher efficacy through five themes: Teacher Efficacy and Professional Growth, Transition and Adaptation, …

Seismic Design And Ductility Evaluation Of Concrete-Filled Thin-Walled Steel Tubular Columns Modeling As Bridge Piers, Njiru Mwaura

Theses and Dissertations

Accurate numerical modeling is essential for evaluating the seismic performance and load-bearing behavior of partially concrete-filled thin-walled steel tubular columns, particularly those used as bridge piers under complex seismic conditions. This study investigates the performance of such columns enhanced with embedded energy-dissipating shell plates and/or partial concrete infill, subjected to unidirectional and bidirectional seismic loading. A validated finite element model (FEM), developed in ABAQUS and incorporating geometric and material nonlinearities—including the modified Two-Surface Model (2SM)—was employed to simulate cyclic behavior and predict structural response.The model was benchmarked against experimental results and used to analyze a broad range of parameters, including …

A Care-Focused Characterization Of Beginning Elementary Preservice Teachers’ Visions Of Mathematics Instruction, Alicia Marie Erwin

Theses and Dissertations

In this dissertation study, I sought to understand how elementary preservice teachers (EPTs) envisioned mathematics instruction at the beginning of their university program and what factors they identified as contributing to those visions. I conducted semi-structured interviews with 32 EPTs who had recently finished their first mathematics content course in their university program. I then connected theories of teacher care to characterize their visions of mathematical instruction.

Through my data analysis, I identified five themes that represented components of the EPTs’ beginning visions of mathematics instruction: Driver of the Math Task, Focus of the Math Task, Student Sharing, Classroom Environment, …

Exploring Nitrate Reduction In A Saturated Riparian Buffer Through A Three-Dimensional Reactive Contaminant Transport Model In An Agricultural Area, Mcclean County Central Illinois, Franklin O. Ijigade

Theses and Dissertations

Saturated Riparian Buffers (SRBs) are engineered systems designed to remove nitrate and other pollutants from subsurface agricultural drainage water before it reaches a stream. This study utilizes a high-resolution coupled flow and reactive transport model to explore nitrate reduction and transformation in an SRB in glacial sediment. The influence of material heterogeneity on nitrate reduction and the effectiveness of the SRB was investigated. The study was conducted in an SRB located next to and receiving tile drainage water that ultimately drains into a 3^rd order stream (T3 stream) in central Illinois, USA. A three-dimensional steady groundwater flow model was …

Promoting A Pedagogy Of Critical Engagement: Teaching English Grammar And Usage Through A Socio-Historical, Investigative Approach, Robin E. Cross Halsey

Theses and Dissertations

This dissertation introduces and explicates a novel pedagogical approach to a university course that focuses on the application of English grammar and usage for writers. This approach to the teaching of English grammar and usage is grounded in several related disciplines and fields of study, including linguistics (specifically historical linguistics and sociolinguistics), language ideologies, and inquiry-based education.

The course curriculum combines examinations of historical ideologies and attitudes that have influenced debates about language usage and the value of teaching grammar with explicit instruction of specific grammar terms and concepts. The initial phase of the course introduces rhetorical grammar, usage and …

The Development Of A One Pot, Two Reaction Synthetic Preparation Of 1,2,4-Oxadiazole, And Synthesis Of Ataluren, A Novel Drug In The Fight Against Duchenne Muscular Dystrophy. Efforts Towards The Synthesis Of A Potential Protease Inhibitor Against The Main Protease (3clpro) Of Covid-19, Austin J. Carter

Theses and Dissertations

1,2,4-Oxadiazoles are five-membered heterocyclic structures first synthesized by Tiemann and Krüger in 1884. Recent discoveries suggest an array of useful biological properties.In preparation of 1,2,4-oxadiazoles, the most prevalent precursors are amidoximes, which can be created via the reaction of nitriles with hydroxylamine hydrochloride and a base. The amidoximes are reacted with an activated carboxylic acid to yield an acylated intermediate. This intermediate can be exposed to a base to cyclize into the 1,2,4-oxadiazole. This thesis describes the efforts in combining these three steps into a unified one-pot synthesis.

Currently, there are a significant number of commercially available FDA approved and …

Analyzing Factors Influencing Employee Turnover In Tech Companies: A Predictive Modeling Approach, Shinjon Ghosh

Theses and Dissertations

Employee turnover poses substantial challenges for technology firms, and understanding its key drivers through predictive modeling is essential for developing effective retention strategies. This study investigates factors influencing employee turnover in technology companies by implementing a predictive modeling approach on the IBM HR Analytics Employee Attrition dataset. The research aims were identifying key factors contributing to employee attrition, developing predictive models to forecast turnover risk, and analyzing interactions among significant predictors. By examining a range of features, the results highlight significant variables (Over Time, Monthly Income, Marital Status, etc.) of attrition and offer actionable insights for developing targeted employee retention …

Asymmetric Synthesis Of The Hiv Protease Inhibitor Tmc-126 And An Anti-Malarial Agent Via A Titanium Tetrachloride Mediated Asymmetric Glycolate Aldol Addition Reaction. Redefining The Curtius Rearrangement Reaction Via Dehomologation Of Carboxylic Acids Bearing Alpha-Leaving Groups, Kweku Amaning Affram

Theses and Dissertations

Acquired Immune Deficiency Syndrome (AIDS) and malaria are two devastating infectious diseases caused by HIV and Plasmodium parasites. AIDS is caused by HIV-1 and HIV-2, transmitted through sexual contact, blood transfusions, needle sharing, and perinatal routes. Malaria, caused by plasmodium parasites through mosquito bites. Today, millions of people around the world have been infected with HIV and malaria and much research has been done to treat it. However, despite advancements in therapeutic options, these diseases remain a significant global health threat, particularly in developing countries due to the emergence of drug-resistant strains for both HIV and malaria complicating eradication efforts. …