Digital Commons Network^™

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 …

Investigation Of Surfactant-Enhanced Oil Recovery In High Salinity And High Temperature (Hsht) Reservoir Conditions: A Case Study In The Bakken Formation, Tomiwa Isaac Oguntade

Theses and Dissertations

This study investigates improved strategies for enhancing oil recovery (EOR) in challenging reservoir conditions by combining chemical surfactant flooding and data-driven optimization techniques. Given rising global energy demand and the depletion of conventional oil reserves, chemical EOR methods, particularly surfactant flooding, are gaining popularity for their ability to mobilize residual oil via mechanisms such as reducing interfacial tension, altering wettability, and inhibiting asphaltene formation. The research begins by examining the effectiveness of surfactant applications across various reservoir conditions, emphasizing the need for surfactants capable of withstanding challenging environments characterized by high temperatures, high salinity, and low permeability. Laboratory experiments demonstrated …

Evaluating The Engineering Properties Of Waste-Modified Asphalt Binders And Mixtures As Inputs For The Mechanistic-Empirical Pavement Design, Duncan Rioba Oteki

Theses and Dissertations

Pavements are essential for economic development and mobility, with asphalt dominating the US road network due to its cost-effectiveness, ease of maintenance, and recyclability. However, the environmental impacts of asphalt production and the depletion of virgin materials have driven the integration of waste products into asphalt mixtures to improve sustainability. This study evaluated the engineering properties of waste-modified asphalt binders and mixtures as performance-based inputs for the Mechanistic-Empirical Pavement Design Guide (MEPDG). The rutting performance of ten asphalt mixtures commonly used in North Dakota was assessed using mechanistic and empirical tests. Mechanistic tests included the dynamic modulus (|E*|), Flow Number …

Integrating Seismic Attributes And Machine Learning For Accurate 3d Petrophysical And Geomechanical Modeling In Shale Plays, Rasaki Olaide Salami

Theses and Dissertations

The increasing reliance on shale plays for hydrocarbon production necessitates accurate 3D petrophysical and geomechanical models to optimize resource recovery. However, conventional methods struggle with shale reservoir complexities such as low permeability, anisotropy, and data heterogeneity, leading to uncertainties in property predictions. This dissertation integrates seismic attributes with machine learning (ML) techniques, including Long Short-Term Memory (LSTM) networks, Temporal Convolutional Networks (TCNs), and Wasserstein Generative Adversarial Networks with Gradient Penalty (WGAN-GP), to enhance predictive accuracy.LSTMs and TCNs effectively capture temporal dependencies, while WGAN-GP generates high-quality synthetic data to mitigate data scarcity. The study critically evaluates existing 3D modeling methodologies, identifying …

High-Fidelity Surface And Environment Simulation Using Immersive Virtual Reality For Lunar Analog Training, Shriya Pedaparthi

Theses and Dissertations

The study explores the integration of high-fidelity Virtual Reality (VR) into astronaut training for lunar analog missions. A realistic VR simulation was developed to represent lunar terrain, allowing participants to perform critical tasks under simulated lunar conditions. Specifically, participants navigated from a compromised lunar habitat (ILMAH) facing a pressure breach, to a secure facility, testing their ability to respond effectively to emergency scenarios. Participants underwent three sequential trials to assess how VR and physical constraints influence gait and performance: (1) a baseline trial measuring natural gait without equipment; (2) a trial incorporating a real spacesuit and lunar gravity simulated through …

Experimental And Numerical Modeling For Co2 Utilization In Enhanced Oil Recovery And Associated Storage In Unconventional Reservoirs, Billel Sennaoui

Theses and Dissertations

Unconventional reservoirs, such as the Bakken and Three Forks formations, present significant challenges due to their ultra-low permeability and complex fracture networks, which limit primary oil recovery to less than 10%. To enhance hydrocarbon extraction while simultaneously facilitating carbon dioxide (CO₂) storage, this study investigates the mechanisms governing CO₂ Huff-n-Puff (HnP) and associated storage under various operational conditions. A comprehensive approach integrating experimental analysis, numerical simulations, multiphase flow modeling, and geochemical interactions is employed to optimize CO₂-EOR and storage strategies. The experimental phase focuses on evaluating the performance of different injected gases (CO₂, ethane, and propane) in the Upper Three …

Mathematical Modeling Of Cyber-Physical Attacks In Iot Systems: An Epidemiological Approach, Tunde Alesinloye

Theses and Dissertations

The Internet of Things (IoT) has made electronic devices more interconnected, which has increased cybersecurity threats while also bringing previously unimaginable convenience. In this study, we explore the dynamics of malware transmission in IoT systems using a mathematical modeling methodology that draws inspiration from epidemiological approaches. To better characterize contemporary cyber-defense tactics like honeypots and proactive device hardening, we specifically suggest the SEIR-DX model, which expands the traditional SEIR framework by adding two extra compartments: Deceptive (D) and Secured (X).

The transitions between the six compartments Susceptible, Exposed, Infected, Recovered, Deceptive, and Secured are described by a system of nonlinear …

An Explainable Ai Framework For Detecting Harmful Algal Blooms (Habs) In Freshwater Lakes, Meera Gopinath Sujatha

Theses and Dissertations

The increase in economic impacts due to the rapid growth of harmful algal blooms (HABs) in freshwater lakes has prompted the development of monitoring and prediction systems. However, limited target data hinders reliable predictions on HAB formations. To address this limitation, this dissertation focuses on providing solutions through data-driven,interpretable, and explainable machine learning models. In Chapter 3, an interpretable multivariate regression model such as Vector Autoregressive (VAR) was used to analyze the important factors that contribute to the formation of cyanobacteria in lakes. The causality tests performed on multiple water quality data helped to determine Alkalinity, Chlorophyll-a (Chl-a), andWater Temperature …

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 …

Inorganic Arsenite [I-As (Iii)] Represses Human Renal Progenitor Cell Characteristics And Induces Neoplastic-Like Transformation, Md Ehsanul Haque

Theses and Dissertations

Studies on populations exposed to inorganic arsenic (iAs) have shown an association between this particular exposure and the development of chronic kidney disease (CKD) and renal cell carcinoma (RCC). However, there are few studies addressing how acute exposure of the human kidney to iAs might lead to long-term alterations that might lead to CKD or RCC. This study’s hypothesis is that renal exposure to iAs might alter the renal cells responsible for the repair and regeneration of nephrons damaged by iAs exposure or other renal toxicants. The kidney possesses a minority epithelial cell population that co-express PROM1 and CD24 that …

Ai-Bms: Ai Battery Management System For Safe Uas Operations In High Electric And Magnetic Fields And Uncertain Conditions: Wind, Battery Drain, Temperature, And Payload, Tanzim Jim Hassan

Theses and Dissertations

Unmanned aerial systems/vehicles (UAS/UAVs) are increasingly utilized for inspecting high-voltage (HV) transmission (Tx) lines. However, operating in the vicinity of electric (E) and magnetic (H) fields can affect UAV control and battery performance. Pilots unfamiliar with high E/H field environments often struggle to accurately estimate remaining flight time, resulting in either premature mission terminations or crashes due to depleted batteries. To address these challenges, this thesis focuses on developing an intelligent Battery Management System (BMS) for UAVs to ensure safe and reliable surveillance operations under various uncertain conditions, such as wind gusts, temperature variations, E/H fields, battery drain, and payload …

White Paper For Faculty Professional Development In Establishing, Addressing, And Informing, To Promote Mental Wellness For Health Careers Students, Betty J. Mcvay

Theses and Dissertations

This research utilized a qualitative case study to explore the need for faculty professional development in the health careers division at a public non-profit California community college, specifically Porterville College. Literature suggests that mental health is a crucial topic to address in contemporary higher education. College students, in general, are facing a notable deterioration in their overall mental well-being, accompanied by an increase in mental disorders. Furthermore, students in health careers programs frequently encounter even more intense stress and psychological challenges, stemming from their constant exposure to high-pressure, emotionally charged situations, and vicarious trauma. Although literature emphasizes the critical need …

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 …

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, …

Modeling Heat Flux Effects On Spacecraft At Atmospheric Re-Entry, Khalid Ayoola, Carson Running

Mechanical Engineering Student Publications

Spacecraft re-entry involves complex thermal and fluid dynamic interactions that critically impact vehicle design and survival. This research investigates heat flux dynamics during atmospheric transition, utilizing the Fay-Riddell equation to model heat transfer through spacecraft surfaces under varying conditions of altitude, Mach number, and nose radius. Key findings reveal that heat flux decreases exponentially with altitude, increases with velocity, and varies significantly with geometric configuration. The analysis demonstrates heat flux ranges from 3.21 × 10^4 W/m^2 with a 3m nose radius at Mach 10 and 30km altitude to 8.32 × 10^6 W/m^2 with a 0.1m nose radius at ground level, …

Gravitational Water Vortex Generator, Lance Roadifer, Carson Running

Mechanical Engineering Student Publications

No abstract provided.

Effects Of Pollution On The Flow Of The Gowanus Canal, Eleanore Dzija, Carson Running

Mechanical Engineering Student Publications

This paper explores how pollution affects the flow of the Gowanus Canal. Four scenarios are modeled to represent different phases of pollution remediation: no remediation, dredging and capping of the canal bottom, combined sewer overflow capture, and dredging and capping with combined sewer overflow capture. Dredging and capping of the canal bottom resulted in the greatest increase in velocity. Dredging and capping with combined sewer overflow capture resulted in the greatest decrease in pressure. This indicates that dredging and capping of the canal bottom may be the most efficient pollution remediation strategy and should be the focus of the cleanup …

The Effect Of Temperature On Power Output From A Hydroelectric Penstock, Taylor Hartell, Carson Running

Mechanical Engineering Student Publications

Hydroelectric power is a form of renewable energy that uses the power from water to generate electricity. One of the ways this is done is by diverting water from a river with a penstock leading to a turbine. Hydroelectric systems rely on water as the source of power, and the viscosity of water varies with temperature. When temperatures are low, viscosity is high, and when temperatures are high, viscosity is low. Other works have studied the optimal dimensions of penstocks for power generation and the effect of hydroelectric power on river temperatures. In this research, the effect of temperature on …

Comparative Study Of Aerodynamic Characteristics Of Standard And Dimpled Naca 0012 Airfoil, Fahim Shahriyar, Carson Running

Mechanical Engineering Student Publications

This study analyzes the aerodynamic performance of a NACA 0012 airfoil with dimples on its upper surface, comparing it to the standard configuration. Using the Navier-Stokes equations, Blasius solutions, the k-ε turbulence model, and ANSYS Fluent, steady-state incompressible flow was simulated at 25 m/s across angles of attack from -20° to +20°. Results show the standard airfoil performs well at the low Reynolds number and lower angle of attack. The inward dimple airfoil reduces drag at negative angles, while the outward dimple airfoil enhances lift at higher positive angles. Shear stress analysis reveals laminar flow on flat plates and turbulent …

Shark Skin Riblet Microstructures: An Oceanic Solution To Reduce Shear Wall Stress And Skin Friction, Ashyln Veitz, Carson Running

Mechanical Engineering Student Publications

Minimizing energy consumption and its associated costs is a key priority in engineering. Potential solutions are found in nature, particularly the skin of the shortfin mako shark. The riblet microstructures have been shown to reduce drag, offering a promising method for energy reduction in various industries. This study investigates the effectiveness of riblet microstructures in reducing wall shear stress and skin friction in laminar flow. The flow over a flat plate is compared with flow over a riblet-structured surface, considering the impact of the temperature of the fluid. Results show that as temperature increases, shear wall stress and skin friction …

An Analysis Of Flow Properties Of Shock Tube Boundary Layer, Cheyenne Harrison, Carson Running

Mechanical Engineering Student Publications

Ice crystal behaviors in the upper atmosphere are very unknown and under-researched, leaving them a mystery as to how they might interact with objects traveling through this region. Currently the University of North Dakota Aerosol Engineering Laboratory is creating an experiment to drop an ice crystal through a vale on a shock tube. This project aimed to solve for properties of the air flow traveling through the shock tube to see how it might affect the falling ice crystal. These properties included Reynolds number, boundary layer thickness, wall shear stress, and velocity contours of the boundary layer. Through Excel and …

The Effects Wind Has On Ocean Current Speeds For Marine Renewable Energy Applications, Parkerjay Hoaglund, Carson Running

Mechanical Engineering Student Publications

This paper explores the influence of wind on ocean current speeds at varying depths and its implications for marine renewable energy systems, particularly underwater turbines. By analyzing the fluid mechanics of ocean currents and applying the Navier-Stokes equations under simplified assumptions, velocity and pressure profiles were developed to model the interaction between wind and water. The research highlights the dependence of ocean current velocity on wind speed and depth, demonstrating that maximum current speeds and power generation potential occur near the ocean surface. Using MATLAB simulations, power generation by an underwater turbine was analyzed under varying wind speeds and depths, …

Airflow Over Nasa’S X-59, Quiet Supersonic Technology (Quesst), Laina Behrenbrinker, Carson Running

Mechanical Engineering Student Publications

The X-59 QueSST is an experimental aircraft that will reach supersonic speeds without producing a loud sonic boom. Those on the ground will hear something like distant thunder as the X-59 passes overhead, around 75 dB. This paper studies the pressure distribution over the nose of the X-59 and the Sound Pressure Level (SPL) on the surface of the X-59 nose (1/3 of the total vehicle length) to better understand how sound propagates through the atmosphere. The resulting SPL over the aircraft nose is 180 – 190 dB, and further the SPL on the ground is calculated to be 43-53 …

Breaking The Sound Barrier: Exploring Ramjet Inlet Dynamics, Daniel Early, Carson Running

Mechanical Engineering Student Publications

This study investigates the impact of varying density, x location, and Mach number on key aerodynamic parameters of a ramjet inlet spike. Density plays a crucial role in equations for Reynolds number, boundary layer thickness, shear stress, coefficient of friction, and coefficient of drag. By keeping all other variables constant and increasing density, an increase in Reynolds number, a decrease in boundary layer thickness, and a decrease in the coefficient of drag was observed. Additionally, the x location along the ramjet inlet spike was analyzed to determine its effects on these parameters. With an increase in x, Reynolds number and …

Polyaxial Stress-Dependent Tensorial Permeability Variations Of A Columnar Jointed Rock Mass: Insights From 3d Distinct Element Method, Prasad Pothana, Vamegh Rasouli, Kegang Ling

Petroleum Engineering Student Publications

Stress-induced permeability changes in geological formations have implications for various geo-engineering applications. Fractures are the predominant fluid flow pathways within tight geological formations such as jointed basaltic rock mass. Three-dimensional permeability variations of a columnar jointed rock mass using the three-dimensional block distinct element method are investigated. First, a permeability tensor is constructed by simulating fluid flow through joint sets using cubic law and determining its principal components through eigenvector analysis. Subsequently, numerical simulations are conducted to gain insights into the impact of principal stresses on joint deformation and fluid flow. Joint deformation is controlled by the joint’s mechanical properties, …

Eminent Domain And The Displacement Of Nd Families: The Impact Of The Garrison Dam, Lauren Steeves

History Hawks: A North Dakota History Zine

This zine looks at the consequences of the United States government exercising the power of eminent domain, as seen in the 1953 United States of America vs. Certain Lands case.

Winter Commencement: December 20, 2024, University Of North Dakota

UND Commencement Programs

UND Winter Commencement program from December 20, 2024.

Science Communication: What Are The Psychological Effects Of Keeping Secrets?, Sydney Rygg

Psychology Student Publications

No abstract provided.

Characterizing The Risk Of Meteorite Ejecta To Future Lunar Surface Operations, Jacob Yates

Theses and Dissertations

In-situ materials provided adequate shielding against the risk of meteorite ejecta for future lunar surface operations. Both regolith simulant and simulant-epoxy mixtures stopped simulated ejecta projectiles with velocities at or near lunar escape velocity. Those depth penetrations for those two in-situ related materials were shallow inside 3 cm and may prove to be influential in future mission planning of lunar surface operations. The lunar surface poses a potential risk from meteoroid ejecta for future lunar surface operations. The safety ramifications of long-term crewed missions for the Artemis program, NASA’s lunar program, are being investigated or reconsidered from the previous Apollo …

Investigation Of Real-Time Gaseous Thermal Decomposition Products Of Representative Per- And Polyfluoroalkyl Substances (Pfas), Kateřina Litvanová, Bethany Klemetstrud, Feng Xiao, Alena Kubatova

Chemistry Faculty Publications

The thermal decomposition of per- and poly fluoroalkyl substances (PFAS) is poorly understood. Here, we present an innovative, comprehensive analytical method to investigate their thermal decomposition, including perfluorocarboxylic acids (PFCAs), alcohol, sulfonates, and GenX (acid dimer), focusing on identifying their breakdown products. In this study, evolved gas analysis–mass spectrometry (EGA-MS) was used for fast real-time screening to determine the significant temperatures to be investigated with the thermal desorption-pyrolysis coupled with gas chromatography–mass spectrometry (TD-Py-GC-MS), which provided detailed information about evolved PFAS and their breakdown products. This approach enabled a systematic study of perfluorocarboxylic acids (PFCAs) ranging from C₃ to …