Digital Commons Network^™

Thermal Modeling Techniques For Additively Manufactured Porous Metals, Lucas D. Rambo

Master's Theses

Advances in additive manufacturing have enabled the creation of metallic components with tailored porosity, offering design flexibility for thermal, structural, and fluid transport applications. This thesis investigates the effective thermal conductivity (ETC) of porous Inconel 625 (IN625) and Inconel-ceramic composites (IN625-RAM2) fabricated by Laser Powder Bed Fusion (LPBF) using Elementum 3D’s PermiAM technology. Experimental measurements of thermal conductivity using the laser flash method are compared to numerical models built from micro-computed tomography data. Simulations were performed using both finite element (FE) and finite volume (FV) methods to evaluate thermal transport in real microstructures. The study investigates the effects of micro- …

Nonlinear Integral Control Schemes For A Cadence-Heartrate Process: A Matlab Exploration, Alexander G. Elliott

Master's Theses

Keeping one’s heart-rate within a specific range during a cardiovascular workout can be difficult due to many factors including variations in the exercise environment and changes in energy level. One’s heart-rate can be controlled by tuning the intensity level of the activity over time. This study focuses on the relationship between a runner’s cadence and their heart-rate and explores ways to control the heart-rate by adjusting the cadence. Previous work in this area modeled the cadence-heartrate plant as a first-order linear system, but this has been shown to be insufficient. This work improves upon previous research in this area by …

From Conflict To Clarity: Resolving Differences In Habitat Assessments To Inform Conservation Priorities For The Giant Kangaroo Rat, Caroline Mackenzie

Master's Theses

From Conflict to Clarity: Resolving Data Differences in Habitat Assessments to Inform Conservation Priorities for the Giant Kangaroo Rat

Caroline MacKenzie

Conservation strategies frequently rely on habitat suitability models, habitat assessments and species occurrence data to identify areas for protection. However, these methods often produce conflicting inference on species presence and habitat quality, complicating management decisions. This study builds on prior work which used three distinct methods to guide conservation planning for the endangered Giant Kangaroo Rat (Dipodomys ingens): habitat suitability modeling based on abiotic predictors, aerial imagery to assess habitat quality through visible burrow mounds and live-trapping …

Multimodal Self-Folding Of Shape Memory Polymer Using Laser Induced Graphene, Liam Harrison Drew

Master's Theses

Shape memory polymers (SMPs) can undergo programmed shape transformations when heated above their glass transition temperature (T_g), enabling actuation through stimuli such as infrared (IR) radiation and Joule heating. These materials are promising for deployable systems and soft robotics due to their lightweight structure and elimination of traditional mechanical components. While IR-based actuation is simple and low-cost, it lacks precision in uncontrolled environments. Joule heating offers improved control but is often limited by conductive ink properties such as thickness, stiffness, or poor adhesion. This work introduces a novel method for multimodal SMP actuation using laser-induced graphene (LIG) transferred …

Effect Of Household Oil Contamination And Agricultural Soil Contamination On Phyllosilicate Nanocatalyst Performance During Pyrolysis Of Polyolefins, Joey Velasquez

Master's Theses

The effect of household oil and agricultural soil contamination on catalyst performance during polyolefin pyrolysis was simulated on mixed virgin plastic pellets by evaluating contamination influence on mixed plastic degradation temperatures. Three phyllosilicate nanocatalysts including Fulcat435, Fulcat22F and Y-Zeolite were evaluated in this work based on a literature review of catalyzed plastic pyrolysis and these catalysts’ ability to lower plastic decomposition temperature by 50 °C – 100 °C. These findings were confirmed in this research through thermogravimetric analysis of a polyolefin mixture and further developed in furnace experiments containing household oil and agricultural contamination. Household oil contamination deactivated each of …

Multibeam Communication With Digital Sparse Arrays, Tavita Dayton

Master's Theses

The thesis presents a novel approach to maximizing spectral efficiency by utilizing spatial spectrum sharing in digital sparse arrays through non-uniform element configurations. A genetic algorithm approach is developed to optimally place the array elements to achieve maximum beam orthogonality and isolation. The proposed method is compared against three different configurations, namely purely random, random with jitter, and the Van Der Corput sequence (a low-discrepancy sampling approach). Simulated results demonstrate that the genetic algorithm and jitter methods successfully meet design specifications for beam orthogonality, average interelement spacing, and computational time. At the same time, the random and Van Der Corput …

Remote Monitoring And Control Of Protection Relays Via Programmable Logic Controller, Rio Mcgown-Kauffman

Master's Theses

The purpose of this study is to explore the ability of a programmable logic controller (PLC) to wirelessly monitor and control power protection relays. The technologies surrounding power protection and industrial automation are ever evolving and have developed significantly in recent history. Industrial power applications call for consistent condition monitoring and status updates for various high-importance components. The high-importance components have power protection schemes that are managed by digital relays to trip circuit breakers in fault or unsafe operating conditions. The smart relays have a wide range of capabilities, including communications. Cal Poly assembled a collection of relays from Schweitzer …

Birch With Tidyclust In R, Jacob Perez

Master's Theses

This thesis introduces a new implementation of the BIRCH clustering algorithm within the tidyclust framework in R. Traditional hierarchical clustering methods face scalability limitations with large datasets, due to their computational complexity. BIRCH offers a scalable alternative by summarizing data into microclusters using a CF-tree. This work shows the integration of the phases of the BIRCH algorithm into tidyclust, which enables a streamlined workflow for model specification, evaluation, and prediction. Through this implementation, scalable hierarchical clustering has been brought to R users within the tidyclust interface, enhacing the ability to better analyze large datasets.

Modeling Battery Energy Storage Systems To Study The Effects Of Battery Chemistry And Operation On Power Quality, Lin E. Knudsen

Master's Theses

This thesis studies the impacts of battery chemistry (specifically lithium-iron phosphate, sodium-ion, and solid-state), AC voltage, battery size, charging mode, state of charge (SOC), active power draw, and power factor on the power quality of a Battery Energy Storage System (BESS). For harmonic evaluation, the metrics provided by the IEEE Standard 519 are used as a guideline to quantify voltage and current harmonics. A comprehensive MATLAB Simulink using Simscape Electrical is used to develop and simulate the models for the battery, DC-DC converter, AC-DC converter, and the grid. A total of 57 simulation cases varying the BESS factors are performed, …

Hands-Free Balance Protocol And Development Of An Iphone App For Self-Assessment, Jacob Matties

Master's Theses

For many clinical populations, the measurement of balance is a critical task. Previous studies have agreed that smartphone IMUs provide a valid measure of balance that can be significantly correlated with force plate measurements and is sensitive enough to distinguish between various balance poses, but many balance assessment protocols require uncommon equipment or the use of hands during assessment. These limit accessibility of balance assessment. To eliminate the need for hands or any additional equipment, this study assessed the use of a smartphone recording the root mean square of 3D acceleration magnitude. The goal of the study was to determine …

Data Driven Analysis Of Samara Seed Kinematics And Dynamics, Shashwat Sparsh

Master's Theses

Samara Seeds are a class of fruit most famously belonging to the Acer species and are characterized by their single-bladed geometry and their auto-rotation response during descent. This steady-state auto-rotation response is the subject of aerodynamic analysis which aim to quantify the performance. The period prior to the beginning of steady-state auto-rotation is classified as the transition regime and has not been the subject of intense scrutiny.

This thesis employs a data-driven approach to analyzing the kinematic and dynamic response of these seeds during both the transition and auto-rotation stages of flight to quantify the performance with respect to the …

Assessing Students’ Attitudes And Self-Efficacy In Introductory Statistics Courses, Kendall Hipes

Master's Theses

This study investigates the cognitive factors that shape students’ experiences in introductory statistics courses, with particular emphasis on the role of self-efficacy sources on student attitudes (mastery experiences, verbal persuasion, vicarious experiences, and physiological and emotional states) measured across multiple time points. Using linear multilevel models and qualitative interview data, the research examines patterns in students’ perceptions of interest, difficulty, effort, value, cognitive competence, and affect throughout an academic quarter. Findings indicate that higher levels of mastery experiences consistently predict more positive outcomes across all attitude dimensions, underscoring the importance of early and ongoing opportunities for success in fostering engagement …

Implementation Of Area-Based Aggregation On Multivariate Continuous Uncertain Data, Rahul Nair

Master's Theses

Uncertain data is incredibly widespread - from sensor data to AI-based learned information, there exists a need to associate information with a certain probability of its veracity. Traditional relational databases lack a built-in functionality to support uncertain data, instead assigning them boilerplate values. Probabilistic databases tackle this problem by assigning non-deterministic data with an associated, often discrete, probability. Variants of probabilistic databases, namely continuous uncertain databases, are used to better model data represented through ranges and distributions. This is especially applicable with sensor-based geographic data as most commercial equipment contains some inherent margin of error.

While uncertain and probabilistic databases …

The Effects Of Sirulina And Nannochloropsis Supplementation On Broiler Performance, Intestinal Morphology, And Gut Microbiology, Emily Beckerman

Master's Theses

The poultry industry is constantly searching for new nutritional strategies and better feed conversion ratio to enhance broiler growth and productivity. Microalgae have been shown to improve broiler performance and health depending on species and supplementation levels. The objective of this study was to determine the effects of Spirulina supplementation (Experiment I) and Nannochloropsis supplementation (Experiment II) on broiler production performance, intestinal morphology, and gut microbiology. In Experiment I, a total of 270 broiler chicks (one-day-old Ross 708) were obtained from a local hatchery after vaccinating against Newcastle, Marek’s disease, and Infectious Bronchitis. They were weighed and sorted into 18 …

Comparative Study Of Experimental And Fea Strain Data For Cnt-Coated Fiberglass Sensors, Extensometers, And Metal Foil Strain Gauges, Omar Dwidar

Master's Theses

Material testing is essential across industries such as aerospace, automotive, and construction, playing a critical role in verifying material selection, diagnosing failures, and understanding the development of flaws in structures. These insights are key to designing successful, reliable systems. Conventional metal foil strain gauges are low cost and reliable but provide limited sensitivity with a typical gauge factor around 2. Extensometers provide highly sensitive strain measurements with the disadvantage of a bulky form factor. With advanced materials such as carbon nanotubes, it is possible to manufacture a sensor with the sensitivity closer to that of an extensometer with the small …

Analyzing Player Difficulty Perception In Platformers Through Procedural Level Generation, Sasank Madineni

Master's Theses

Games utilizing Procedural Level Generation (PLG), such as Roguelikes, are becoming increasingly popular in today's gaming sphere. In games employing PLG, levels are generated randomly or pseudo-randomly, and aim to retain player attention through variance in levels between playthroughs. However, when generating levels with variance in structure and design, player enjoyment is often a mixed bag. With low enjoyment, player retention for these games can dwindle. This study explores the efficacy of real-time difficulty adjustment in procedurally generated platformers, as a method for maintaining stable player enjoyment without causing frustration. This thesis focuses on creating a short user experience, MIMEVA, …

Hybrid Computing For Real-Time Model Predictive Control Of A Buck Converter, Grace Paladichuk

Master's Theses

Advancements in power electronics require high switching frequencies which the digital control routines of the systems cannot keep up with. Analog computing is added to digital control systems to prevent bottlenecks and allow real-time implementation. This paper proposes a hybrid computing model predictive control system for a buck converter. The control system implements the gradient dynamics of the optimization function using digital computing, and the gradient dynamics for the penalty function and integrator using analog computing. For the full simulations of the entire system, the PLECS RT Box is used to simulate the controller in real time with a 1 …

Bentonite Erosion And Cation Exchange Effects On Hydraulic Conductivity Of Geosynthetic Clay Liners, Grace Paananen

Master's Theses

Geosynthetic clay liners (GCLs) are used in municipal solid waste landfill (MSW) liner and cover systems as an alternative to thick compacted clay layers. Previous field studies have revealed potential for bentonite erosion in GCLs when subjected to wet-dry cycles that occur when GCLs are placed on slopes, covered with a geomembrane, and left exposed without additional soil cover. A laboratory test program was conducted to quantify the effects of bentonite erosion on hydraulic conductivity of sodium-bentonite geosynthetic clay liners and samples subjected to cation exchange treatment in addition to bentonite erosion. This test program determined what level of bentonite …

Determinants Of Integration: Migration Difficulty, Mental Health, And Social Connections Among Eritrean Immigrants, Shewit Woldemichael

Master's Theses

This thesis explores how the experience of migration hardship affects integration outcomes of Eritrean migrants in the U.S. and the Netherlands. Using original survey data and the Immigration Policy Lab’s Integration Index (IPL-24), this paper investigated the intersection of economic, psychological, and social interactions that facilitate integration outcomes. This research finds that migration hardship doesn’t just make people’s lives more difficult; it breaks down the social ties and mental well-being that are essential for economic success measured by integration.

The Impact Of Growth Hormone-Releasing Hormone Antagonist On Human Adipose-Derived Stem Cells, Jeanne Michelle Dugas

Master's Theses

Obesity is a condition that affects over 40% of American adults and contributes to numerous preventable health issues. This condition is caused by increased adipose tissue, which forms when stem cells transform into adipocytes. Mesenchymal stem cells, including human adipose-derived stem cells (hASC), are multipotent with the ability to differentiate into adipocytes, osteocytes, or chondrocytes. Many factors affect this transformation, including the peptide growth hormone-releasing hormone (GHRH). The main role of GHRH is to trigger the release of growth hormone, but it has also been found to play an important role in adipocyte metabolism. We expect that if the differentiation …

The Antioxidant Potential Of Rosemary Leaf-Derived Nanovesicles, Shani Akila Griffin

Master's Theses

Human dermal fibroblasts are essential for maintaining skin homeostasis. However, exposure to exogenous and endogenous stressors can lead to fibroblast instability, extracellular matrix degradation, and excessive reactive oxygen species (ROS) production. These factors contribute to skin aging and ROS-induced skin disorders leading to hair loss. Adverse effects from synthetic treatments have driven interest in natural alternatives like plant extracts for skin therapy. However, the polyphenols in these treatments require an effective delivery system to ensure their stability and targeted application. Plant derived nanovesicles (PDNVs) are emerging as a promising natural alternative for therapeutic applications. Their biocompatibility, stability, and encapsulated compounds …

Dsa-Api: Data Standardization Automation Using Ai-Powered Apis, Andrew Asher Turner

Master's Theses

The common factor with current implementations of Artificial Intelligence (AI) is data. Companies are constantly looking for new ways to analyze data, but it comes in various formats: Text, Comma Separated Value (CVE), JavaScript Object Notation (JSON), Extensible Markup Language (XML), and Excel. How can AI be adapted to standardize formats for data analysis, integration, and digestion efficiently? Published research acknowledged that Machine Learning (ML) and AI can provide an automated method to speed up this process and limit the human decision-making error. With the advancement in AI, Application Programming Interfaces (APIs) prompt the idea that they can take in …

Loadshedding And Nighttime Light Intensity In South Africa: Evidence From High-Frequency Satellite Data, Jurney Lajos

Master's Theses

This paper investigates the relationship between loadshedding and nighttime light intensity in South Africa using high-frequency satellite data from 2020 to 2024. By linking rotational blackout schedules to daily radiance measurements at the suburb level, the study examines how electricity disruptions affect visible light emissions and whether these effects vary by wealth. Results show that while load shedding has be-come increasingly severe in recent years, its impact is not felt equally. Poorer suburbs experience larger and more persistent reductions in nighttime radiance during black-outs, suggesting limited capacity to adapt. In contrast, wealthier suburbs show signs of resilience, with smaller drops …

Mitigating Agricultural Income Volatility: Evidence From Crop Insurance Adoption In India, Annoushqa Bobde

Master's Theses

Income volatility resulting from crop loss presents a significant threat to rural livelihoods in India, where nearly half of the workforce is employed in agriculture. This study examines the causal impact of crop insurance uptake on farm income using nationally representative data from the 70th and 77th rounds of the National Sample Survey, merged with satellite-derived climate data and Harmful Degree Days (HDD), which is used as a proxy for crop-damaging temperature. To address selection bias in insurance enrollment, Propensity Score Matching, Inverse Propensity Weighting, and a Two-Way Fixed Effects model are used. Results show that insurance uptake is associated …

Weather Impacts On Migration And Food Insecurity In Bangladesh, Brendon M. Wong, Andrew Hobbs

Master's Theses

This paper analyzes the impact of weather shocks on household migration and food insecurity, and the mechanisms in which they do so. As climate change continues to impact weather patterns, subsistence farmers remain extremely vulnerable and can experience decreases in welfare. Using the Bangladesh Integrated Household Survey, we construct a panel dataset to measure the effects of temperature and rainfall on remittance amounts, food consumption scores, and child wasting z-scores. We observe that weather has strong impacts on these outcomes but are dependent on the rice variety and growing season. We do not find strong evidence that the mechanism in …

Climate Shocks, Crop Yields, And School Enrollment In Rural Ethiopia, Mallika Matharu

Master's Theses

This study investigates how climate-induced shocks to agricultural productivity affect school enrollment in rural Ethiopia. Using five waves of panel data from the Ethiopia Living Standards Measurement Study (LSMS) and satellite-derived weather indicators, I estimate the causal effects of crop yields, specifically Teff, Sorghum, and Maize, on children’s school attendance. To address the endogeneity of agricultural output, I instrument crop yields with agro-climatic measures such as growing degree days (GDD), harmful degree days (HDD), and soil moisture during the Meher growing season. The main empirical strategy uses a two-stage instrumental variable approach with region and wave fixed effects. Results suggest …

The Long-Term Effect Of Universities On Local Technology, Dafina Rizvanolli

Master's Theses

This paper studies the long-term effects of universities on local economic complexity, contributing to new evidence on how higher education institutions shape local productive capabilities over time. While extensive research documents universities’ positive impact on development, fundamental questions remain about the mechanisms through which they operate. Our study employs the Economic Complexity Index (ECI), a measure that captures the diversity and ubiquity of regional economic structures, to provide novel insights into universities’ influence on local economies. Building on Andrews (2023), we exploit historical natural experiments in university site selection during the 19^th and 20^th centuries in the U.S. …

Sustainability In Professional Sports: A New Nexus Of Profit And Social Responsibility, Matthew Teplitz

Master's Theses

The world is facing a climate crisis – corrective action that will improve our collective situation is needed, now. Those with the power to do so, in the capitalist structure under which we live, are largely the individuals, corporations, and governments with financial resources and the platform to inspire others to act. Two such entities, complete with the financial heft to make a difference and inspiration to spare, are North America’s National Basketball Association (NBA) and Spain’s La Liga. This thesis seeks to understand what distinguishes the NBA’s approach to sustainability from La Liga, and by employing each league as …

Identification Of Methylation Patterns, Associated Dna Methylating Proteins, And Methyltransferase Inhibitors On The Promoter Regions Of Dax-1, Brandon Tyler Toy

Master's Theses

The DAX-1 gene (Dosage-Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, Critical Region on the X chromosome, gene 1) encodes for an orphan nuclear hormone receptor and its mutation is implicated in multiple diseases including congenital adrenal hypoplasia, adrenal cancer, and breast cancer. Previous research has linked DAX-1 downregulation to tumor initiation in breast tissue, suggesting the gene acts as a tumor suppressor with respect to breast cancer. Additional studies completed by the Tzagarakis-Foster laboratory have shown that methylation of the DAX-1 promoter region is heavily influential in breast cancer development, with release of epigenetic repression resulting in slowing of cellular proliferation …

Reverse Engineering Of Binary Programs Using Graph Attention Networks, Sai Nikhila Kanigiri

Master's Theses

Understanding the functionality and behavior of binary code is essential for many software engineering tasks, including malware analysis, vulnerability detection, and program optimization. However, automating this process is challenging due to the complexity of machine code and the significant manual effort required from experienced software engineers. In this paper, we present BinGAT (Reverse Engineering of Binary Programs using Graph Attention Networks), a method for classifying binary programs into algorithmic categories using Graph Attention Neural Networks (GNNs) based on their Control-Flow Graphs (CFGs). Given a binary program, BinGAT extracts its CFG through static analysis and transforms the assembly instructions within each …