Digital Commons Network^™

Advanced Optimization And Integration Of Propellant Flow Path For Cntr Fuel Tube, David Cox, Michael Rietze, Karl Lauture, Max Lowe, Elijah Spencer, Kojo Pinkrah

Mechanical Engineering Capstone Design Projects

The Centrifugal Nuclear Thermal Rocket (CNTR) is an advanced propulsion concept whose performance is strongly influenced by the efficiency and continuity of its propellant flow path. This project focuses on improving the geometric integrity and analytical fidelity of the CNTR fuel tube inlet and manifolds, which are critical subsystems governing pressure losses and downstream performance. In prior designs, these parts consisted of multiple components assembled using adhesive, introducing geometric discontinuities that increased head losses and limited the reliability of computational analysis.

In this work, the inlet and manifold were successfully redesigned as single, integrated components. This redesign represents a key …

Constraint-Aware Metaheuristic Optimization For Experimental Design, Benjamin N. Fuller

All Graduate Theses and Dissertations, Fall 2023 to Present

Designing experiments becomes much more challenging when many variables and strict constraints are involved, as is common in modern science and engineering. This thesis introduces a new computational and mathematical framework that efficiently searches for optimal experiments in complex, high-dimensional spaces where traditional methods fail. By combining geometric techniques with flexible optimization algorithms like particle swarm optimization, our methods handle difficult constraints while scaling to real-world problems. Built in the high-performance Julia programming language and released as open-source software, this work bridges advanced theory with practical tools, offering researchers a powerful and accessible way to design better experiments under realistic …

Ionospheric Plasma Electron Density Measurement And Theory Using Impedance Probe Techniques, Justin Wellington

All Graduate Theses and Dissertations, Fall 2023 to Present

The ionosphere plays a critical role in how radio frequency (RF) signals, like those used in Global Position System (GPS) satellite communications, travel through space. Disturbances in the ionosphere, such as equatorial plasma bubbles (EPB), scatter these signals and cause communication dropouts or navigational errors. To study these conditions, spacecraft use instruments that measure the surrounding plasma directly. One of these instruments is an impedance probe, which applies a small electrical signal to a sensor and determines electron density from the measured impedance.

This thesis improves the modeling and interpretation of impedance probe measurements. A numerical method is developed that …

Effects Of Beaver Dams On Components Of Riverscape Health And Biodiversity In The Great Basin, Cashe C. Rasmussen

All Graduate Theses and Dissertations, Fall 2023 to Present

Networks of rivers and their floodplains (i.e., low-lying areas adjacent to rivers and streams that could plausibly flood) have been degraded, reducing the availability of freshwater and habitat for people and wildlife. Therefore, land managers are pursuing cost-effective restoration strategies, including partnering with beavers (Castor canadensis), to promote the health of these ecosystems and associated benefits. However, our understanding of beaver-mediated restoration benefits remains incomplete. Here, we compared locations along streams with and without beaver dams to measure the benefits of beavers in the Great Basin of the Western United States. We measured the effects of beaver dams …

Adversarial Heterogeneous Agent Learning For Robotic Systems: A Framework For Coordinated Competitive Behaviors, Christopher T. Allred

All Graduate Theses and Dissertations, Fall 2023 to Present

Autonomous robot teams must move reliably, explain their actions, and work together—even in changing or adversarial settings. We present a structured, three-stage pathway that builds coordinated team behavior from strong single-robot skills. First, we develop robust legged-robot locomotion and interpretability using only internal actuator signals. From these proprioceptive cues, robots learn to classify terrain and predict short-term power use, enabling energy-aware movement without external sensors. We further analyze learned behaviors with motif discovery to reveal recurring sensor–action patterns, which clarify how agility emerges and guide reward design. Second, we compose these skills into heterogeneous teamwork using centralized training with decentralized …

Unpacking Science Achievement: Institutional Alignment And Mediating Conditions In A High-Performing Charter School, Brenda L. Bennett

All Graduate Theses and Dissertations, Fall 2023 to Present

This study examined how science instruction was sustained over time within a high-performing public elementary charter school. Rather than focusing on individual programs or teaching strategies, the research explored how schoolwide systems, relationships, and supports worked together to shape classroom practice.

The study focused on one public K–6 charter school in a western state with consistently strong science performance on state-reported measures and examined how institutional, organizational, and classroom conditions mediated the relationship between science instruction expectations articulated in state and charter policy and teachers’ enacted practice.

Results suggested that strong science instruction was not produced through strict mandates or …

Two Applications Of Lifting-Line Theory For The Design Of Efficient Aircraft, Amanda K. Olsen

All Graduate Theses and Dissertations, Fall 2023 to Present

Numerical lifting-line is a tool that can be used to evaluate the forces and moments of an aircraft wing. This method has limitations but it is beneficial in obtaining a large set of results with relatively little computational power. This research seeks to analyze two different flight scenarios through the use of two numerical lifting-line tools developed at the Utah State University AeroLab. The first scenario involves an aircraft in ground effect flight. When an aircraft flies close to the ground, a phenomenon called ground effect occurs where the lift is increased and the induced drag is decreased. Therefore, flying …

Comparing Strategies For Wetland Revegetation In An Uncertain Water Future, Hailey M. Machnikowski

All Graduate Theses and Dissertations, Fall 2023 to Present

Wetlands worldwide are expected to experience more frequent and intense droughts and floods due to climate change. These shifting water conditions introduce challenges to restoring wetland plants, especially using direct seeding. Seeding is cost and labor-efficient compared to planting, but seeds and seedlings are highly vulnerable to water stress, so restoration efforts often fail when conditions are too wet or dry. Understanding how to improve seed-based revegetation under these conditions is increasingly important. Therefore, we sought to understand the response, measured by percent canopy cover or dry biomass weights, of native plants to different durations of drought in greenhouse experiments, …

Advancing Context-Aware Detection Of Socially Harmful Discourse Using Transformer-Based Models, Santosh Chapagain

All Graduate Theses and Dissertations, Fall 2023 to Present

Social media platforms are a central part of modern communication, shaping how people share ideas, build communities, and discuss social issues. While these spaces can support connection and self expression, they also enable the spread of harmful language such as hate speech. At the same time, social media is an important place where members of marginalized communities, including sexual and gender minorities, express stress, discrimination, and emotional challenges in ways that are often indirect and context dependent.

This research examines whether modern artificial intelligence systems can better identify harmful language and expressions of minority stress in online posts. The study …

Analyzing The Influence Of Stem Project-Based Learning On Students' Perceptions And Career Interest In Stem, Melissa S. Barker

All Graduate Theses and Dissertations, Fall 2023 to Present

Although science, technology, engineering, and mathematics (STEM) enrichment programs aim to increase participation in STEM, the design features that meaningfully influence adolescents’ task values and career-related beliefs remain insufficiently specified. The purpose of this study was to investigate whether STEM PBL activities designed with an interest-focused theoretical lens of Subjective Task Value (STV) and Social Cognitive Career Theory (SCCT) influence students’ perceptions of STEM courses, majors, and careers. Additionally, I sought to understand what elements of the STEM PBL experience were most impactful. I designed and taught STEM PBL activities for students from the Native American lands in southeastern Utah …

Post-Wildfire Erosion And Biogeochemistry: Integrating Aerial Imagery And Soil Testing To Assess Landscape Recovery, Justin A. Allred

All Graduate Theses and Dissertations, Fall 2023 to Present

After a wildfire, land managers are required to monitor large tracts of land with limited time and budgets. Traditionally, tracking landscape recovery is a time intensive process. This research explored the effectiveness of using drones (UAVs), strategic soil sampling, and computer modeling as additional tools for land managers in order to monitor the recovery more efficiently.

By using drones to collect aerial imagery and using machine learning, plant regrowth was monitored in back-to-back years. The machine learning model performed well at telling broad groups apart (trees vs grass) but it struggled to identify differences between plant species. Because many plants …

Factors Affecting Mathematics Teachers’ Instructional Decision-Making: An Ecological Systems Theory Multiple-Case Study, Camille M. Lund

All Graduate Theses and Dissertations, Fall 2023 to Present

Though research on effective mathematics instructional strategies is robust, there remains a gap between research and the instruction that takes place in mathematics classrooms. One such effective instructional practice—mathematical student discourse (MSD)—has been extensively researched, but little research has looked holistically at the ecological factors that interact to influence teacher decision-making for this practice. In this qualitative multiple-case dissertation study using Urie Bronfenbrenner’s ecological systems theory as a theoretical lens, I conducted semi-structured interviews with three elementary teachers who teach mathematics in districts across northern Utah. These interviews utilized the researcher-created Ecological Factors Map to explore how teachers described the …

Mapping Spatial Variability For Precision Management In Utah’S Tart Cherry Orchards, Kurt T. Wedegaertner

All Graduate Theses and Dissertations, Fall 2023 to Present

Tart cherry orchards are a major part of the agricultural landscape in Utah, but producing cherries is becoming increasingly difficult and expensive. Orchard land is not uniform. Some parts of a field grow strong, healthy trees, while other parts struggle because of differences in soil, water, and landscape. Even though these differences exist, orchards are usually managed the same way everywhere. Over many years, this causes some trees to become much larger than others, making orchards harder to manage, less efficient to harvest and prune, and more costly to maintain.

This research focused on finding practical ways to measure these …

Dyadic Agreement In And Task Correlates To A Measurement Of Conversational Success, Samantha Budge

All Graduate Theses and Dissertations, Fall 2023 to Present

Successful conversation matters for social connection, wellbeing, and quality of life, but people do not always agree on whether a conversation was successful, even when they participated in the same interaction. Conversation is also commonly measured through task success, even though it’s unclear how task success correlates to how successful a conversation feels. This study examined how conversational success is experienced by different conversation partners and whether feeling successful in a conversation is related to how well a task is completed.

Participants took part in a structured conversational task and then rated their own conversational experience using a self-report questionnaire …

Probing The Roles Of Connexin 43 Hemichannels In A Mouse Model Of Alzheimer's Disease, Madison Treasure-Areno

All Graduate Theses and Dissertations, Fall 2023 to Present

Alzheimer’s disease is a progressive disorder involving neuronal death and cognitive decline, such as memory loss and changes in personality. One feature of the disease is buildup of abnormal protein called amyloid-beta in the brain. Amyloid-beta may activate support cells called astrocytes, triggering them to release large amounts of chemicals, possibly harming nearby cells. This study set out to examine the roles of the channels on astrocytes involved in releasing these chemicals, called connexin 43 hemichannels. Using a mouse model of Alzheimer’s disease, this study blocked the hemichannels using the drug Tonabersat, and measured spatial learning and memory in a …

Examining Middle School Girls' Self-Efficacy Changes During A Design-Based Engineering Unit, Emily Lehnardt

All Graduate Theses and Dissertations, Fall 2023 to Present

Drawing on Bandura’s self-efficacy theory, this exploratory multi-case study examines how engagement in an engineering designed-based unit, specifically through an intervention focused on iterative improvements, influences middle school girls’ self-efficacy. This study was conducted in a suburban public middle school. It involved five female participants enrolled in a seventh-grade science classroom. Qualitative data were collected from pre- and post-interviews, self-reflection journals, observations and student artifacts. Multiple data sources were triangulated to ensure the credibility and depth of the findings. Qualitative data were analyzed using inductive and deductive coding to produce open codes, axial categories driven by Bandura’s four sources of …

Extracting Wildfire Influence From Natural Streamflow Variability To Inform Post-Fire Peak Flow Predictions, Haley Anne Canham

All Graduate Theses and Dissertations, Fall 2023 to Present

Wildfire is a natural process, however, wildfire occurrence, severity, and size is increasing globally along with large storms. Despite the expectation that floods will be larger after wildfire, a large range in post-fire flood size has been observed. This creates challenges for emergency managers to prepare for flooding in areas where wildfire might occur. Aside from wildfire, many other factors influence the size of floods, making it difficult to isolate the influence of wildfire. This work finds that factors including wetter versus drier years and seasons can alter the size of a flood, effectively hiding the influence of wildfire. Additionally, …

Examining Motivations And Perceptions In Secondary Technology And Engineering Education: A Gendered Analysis Using The Fit-Choice Scale, Abigail Villanueva

All Graduate Theses and Dissertations, Fall 2023 to Present

This study examined why individuals choose to become secondary technology and engineering education (TEE) teachers and whether motivations differ between men and women. TEE programs help prepare students for careers in science, technology, engineering, and math (STEM), yet schools face teacher shortages and low female representation in the field. Understanding what draws people to this profession can support better recruitment and retention efforts. Sixty-six current TEE teachers completed a survey about the factors that influenced their decision to teach. Overall, the strongest motivations were a personal interest in teaching, enjoyment of working with young people, and the desire to make …

The Fourth Skill Revisited: A New-Ish Approach To Latin Pedagogy, Tyler Perry

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis examines a new way of teaching Latin that combines Gareth Morgan’s The Fourth Skill method with the traditional grammar-translation approach. Latin teaching has often moved between two extremes. Grammar-translation focuses heavily on analyzing grammar, while modern immersion-style approaches focus more on understanding the language through exposure. Each method has strengths but also clear limitations. Morgan’s The Fourth Skill (1968) tried to balance these approaches by focusing on reading real Latin texts, but it relied heavily on Morgan’s personal teaching and included little direct grammar instruction.

To address these problems, this study tested a revised version of the method …

How Novices Write Code: Discovering Best Practices, Matt Rau

All Graduate Theses and Dissertations, Fall 2023 to Present

Learning to program is a difficult endeavor, leading to chronically high failure rates in introductory programming courses. One thing that makes teaching programming difficult is that we don’t fully understand what problem solving habits and writing strategies separate successful programmers from struggling ones. Knowing how to teach these habits to a new programmer is an equally difficult challenge,

Studying the way people write code has proved difficult. Until recently, there was very little relevant publicly available data, and no good ways to analyze student programming behavior at a large scale. In this thesis, I address both issues. I publish a …

Developing Fragility Curves For Steel Special Moment-Resisting Frames In Utah, Olivia P. Murphy

All Graduate Theses and Dissertations, Fall 2023 to Present

Major seismic events along the Wasatch Fault represent a serious threat to Utah's residents and built environment. Engineers currently rely on a statistical approach that calculates earthquake ground shaking based on probabilities of various events occurring over extended time periods. This method informs how strong new buildings must be constructed. However, many structural engineering professionals in Utah worry that this probability-based approach may significantly underestimate the actual ground shaking compared to an alternative method that examines the largest possible earthquake a fault can generate. The substantial differences between the two analytical approaches raise fundamental concerns about whether existing construction standards …

The Impact Of Ai Companions On Family Law, Clare Huntington

Cardozo Law Review

People of all ages and backgrounds regularly use AI companions—virtual friends, lovers, and confidantes powered by artificial intelligence. As a new form of relationship, this development poses novel doctrinal and policy questions for family law. As a doctrinal matter, what does child neglect look like when a parent delegates caretaking to an AI companion? How should standards for elder neglect adapt to the widespread use of robotic caregivers? Should lawmakers impose mandatory reporting requirements on therapy bots if children share experiences of abuse or neglect? And can people designate an AI companion as a health care proxy? As a policy …

An Assessment Of The Deep And Coastal Responses To Hurricane Passage In The Gulf Of Mexico, Using Complementary Observational Records And Model Simulations, Senam Kofi Tsei

Dissertations

In this dissertation, I examine and discuss different ocean features and ocean processes essential to the intensification of tropical cyclones in the Gulf of Mexico, drawing on observations, theory, and numerical model analyses across both the deep ocean and continental shelf-regimes. In the deep ocean, I integrate in situ measurements, theoretical framework, a 1D shear driven mixed layer model, and a high resolution model outputs to evaluate how salinity-driven stratification, Loop Current warm core eddies, pre-existing warm mixed layer temperatures, and the governing mechanisms mixed layer adjustment shape the upper ocean response before, during, and after storm passage. In the …

The New Wild West: A Case Study Analysis Of The Communication Methods Surrounding Ai Infrastructure In West Texas, Thomas Sorensen

Electronic Theses and Dissertations

In the past several years, artificial intelligence has taken the world by storm. It has enabled numerous innovations across all sectors, and its usage continues to grow daily. This increase in demand for AI products has led to the development of AI data centers nationwide. Fueled by competition between the public and private sectors, many projects are underway. This study focuses on one such project in West Texas: the Stargate Data Center. This project is being constructed near Abilene, Texas, and has had an instrumental impact on the daily lives of its citizens. This research project seeks to answer the …

The Legal Framework For Direct Ocean Carbon Capture And Storage (Volume 2: The United States), Korey Silverman-Roati, Romany M. Webb

Sabin Center for Climate Change Law

This paper, the second in a series of two, focuses on the U.S. legal framework for the marine carbon dioxide removal (mCDR) approach of direct ocean carbon capture and storage (DOCCS). The first explores DOCCS governance under international law and is available here: https://scholarship.law.columbia.edu/sabin_climate_change/271/.

DOCCS aims to remove some of the carbon currently stored in the ocean and thereby enable it to uptake additional carbon dioxide from the atmosphere. DOCCS is still undergoing research, but early studies suggest it could have significant carbon dioxide removal potential. However, DOCCS could also present environmental and other risks, including from the construction …

Sympathetic And Parasympathetic Ganglion Blocks For Treatment Of Long Covid-19 Symptoms: A Scoping Review, Abhay Tyagi, Khushboo Singh, Preet Mohinder Singh, Frederic J Gerges

2020-Current year OA Pubs

BACKGROUND: Long COVID-19 affects approximately 10-30% of individuals who are infected with SARS-CoV-2 and is associated with persistent functional impairment and reduced quality of life. The heterogeneous, multisystemic nature and nonspecific symptomatology of long COVID-19 makes its treatment challenging. This scoping review evaluates existing evidence on sympathetic and parasympathetic ganglion blocks as potential interventions for patients suffering from long COVID-19.

OBJECTIVE: Our primary objective was to assess the effectiveness of sympathetic and parasympathetic ganglion blocks in treating patients with long COVID-19 by identifying the most commonly reported symptoms, symptom response to different block regimens, and any adverse effects associated with …

The Federal Reserve’S Fiscal Agent Mandate And The Problem For Central Bank Independence, Lev Menand, Joshua Younger

Faculty Scholarship

The Federal Reserve is among the most powerful organs of government. It is tasked primarily with maintaining the growth of monetary and credit aggregates consistent with long-run maximum employment and price stability. This mandate is widely known and the subject of extensive public debate. But another mandate lies within the statute that is largely overlooked — to serve as fiscal agent of the United States. This distinct responsibility is older, and also important. This Article offers a comprehensive assessment of where the Fed’s two mandates overlap and occasionally sharply conflict: in the market for U.S. government debt. First, it identifies …

Sticky Charters? The Surprisingly Tepid Embrace Of Officer-Protecting Waivers In Delaware, Jens Frankenreiter, Eric L. Talley

Faculty Scholarship

This article examines the response to Delaware’s much-heralded 2022 legal reform that permitted corporations, for the first time, to adopt charter provisions exculpating corporate officers from liability for breaching their fiduciary duty of care. Contrary to widespread predictions that corporate actors would swiftly adopt officer exculpation provisions, our analysis — using both traditional and generative artificial intelligence (AI) methods — reveals a surprisingly low rate of uptake, over three years after the reform’s enactment.

Our study makes both methodological and substantive contributions. Methodologically, we present a novel application of large language models (LLMs) to identify and interpret technical clauses in …

Stance And Gait Analysis Of Apollo Astronauts On The Moon, Faye Y Chiou-Tan, Conrad Li, Jason P Caffrey, Millard Reschke, Timothy R Macaulay

Faculty, Staff and Students Publications

Introduction/aim: As humans return to the Moon, safe efficient ambulation and fall prevention on the lunar surface are key concerns. The analysis of gait from archived Apollo mission video footage is now possible with pose estimation video analysis software. Thus, this study aims to retrospectively quantify parameters of Apollo astronauts' stance and gait on the Moon.

Methods: Publicly available National Aeronautics and Space Administration (NASA) footage of astronauts ambulating on the Lunar surface was examined using body pose analysis software. Goniometric lower limb joint/torso angles and width of base of stance and gait were derived. Gait cycle stance phase, swing …

Building Services Engineering March/April 2026

Building Services Engineering

No abstract provided.