Digital Commons Network^™

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 …

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 …

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 …

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 …

Building Services Engineering March/April 2026

Building Services Engineering

No abstract provided.

Freshwater Mussel Reintroduction And Recolonization Habitat Modeling Using Hydraulic, Sediment And Geomorphic Parameters, Megan Elizabeth Dinicola

All Graduate Theses and Dissertations, Fall 2023 to Present

Freshwater mussels are an important group of aquatic animals that live within the riverbed, but their populations have been drastically reduced by habitat alteration and other anthropogenic activities. In an effort to bolster populations, river managers and biologists are using mussel reintroductions as part of their restoration efforts but there are gaps in our understanding of where to reintroduce mussels within a river to see them create self-sustaining populations. This research helps shrink this gap by better understanding the physical habitat needs and population expansion potential of subadult freshwater mussels, or the size of mussel that hatcheries grow for reintroduction, …

Relaxed Convex Approximation For Optimal Control In Cislunar Space, Jondavid K. Hertzel

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis develops a method of optimal control for a spacecraft in the region between the Earth and the Moon known as cislunar space. The optimal control method is developed through a modern optimization technique called “convex relaxation” to achieve a formulation that can be reliably solved by numerical computation tools. The primary research objective is to evaluate the efficacy of this method in accommodating the physical thrust constraints of a spacecraft. This approach is tested in simulation with an unstable halo orbit around the Moon in the circular restricted three-body problem (CR3BP) model. The simulation incorporates realistic disruptions from …

Development Of A Novel Method For Simultaneously Testing Multiple Specimens To Evaluate Tension-Tension Fatigue Life, Mehedi Hasan Mahfuz

All Graduate Theses and Dissertations, Fall 2023 to Present

The aim of this study is to develop a novel method for rapidly evaluating the tension–tension fatigue life of metals. Fatigue failure, which occurs when materials gradually weaken and fracture under repeated loading, is a critical concern in designing safe and reliable structures such as airplanes, cars, and bridges. Traditional fatigue testing methods are slow, costly, and typically limited to one specimen at a time. To address this, a high-throughput testing method was developed that allows multiple small-scale specimens to be tested simultaneously while following international testing standards. Using stainless steel sub-sized specimens scaled at 1:5 relative to the ASTM …

Effects Of Subsurface-Drip-Irrigation On Alfalfa Evapotranspiration In The Intermountain West, Namuna Dhakal

All Graduate Theses and Dissertations, Fall 2023 to Present

Alfalfa is one of Utah’s most important crops, but it is also the largest agricultural consumer of water. Because the state faces frequent droughts and growing pressure on limited water supplies, farmers and water managers are increasingly interested in irrigation systems that could reduce water use. Subsurface drip irrigation (SDI), which delivers water directly to plant roots through buried drip lines, has shown promising results in other regions, where it often reduces water consumption and increases yield. However, little research has evaluated SDI under Utah’s unique climate, soils, and high-elevation valleys.

This study compared an SDI system with a traditional …

Developing And Improving Digital Image Correlation (Dic) Techniques For Challenging Environments, Prasenjit Dewanjee

All Graduate Theses and Dissertations, Fall 2023 to Present

Understanding how materials and parts deform during testing is crucial for creating safer and more reliable engineering systems. Engineers need to measure not only how much a part deforms, but also where deformation concentrates before any damage or failure happens. Digital image correlation (DIC) is a camera-based, non-contact measurement method that tracks surface motion and deformation across a whole area. It is particularly useful when traditional contact-based measurement techniques cannot withstand harsh conditions or capture enough detail. This dissertation develops optical methods to improve DIC in three challenging measurement situations. First, a shortwave ultraviolet lighting technique is developed to reduce …

Spatial And Seasonal Concentrations Of Atmospheric Halogens Around The Great Salt Lake (2023/2024), Himalaya Sapkota

All Graduate Theses and Dissertations, Fall 2023 to Present

The Great Salt Lake (GSL), located in northern Utah, is one of the world's saltiest lakes and an essential resource for industry. It is also a significant hotspot for halogen emissions, including chlorine (Cl) and bromine (Br) from both natural and human sources. Although their concentrations in the atmosphere are low, they influence tropospheric chemistry by forming criteria pollutants such as ozone and particulate matter. These pollutants are detrimental to air quality, impacting public health and property. This study investigates the spatial and seasonal variability of halogen species (gas- and particulate-phase of Cl and Br) in the Northern Wasatch Front …

Development Of A Laboratory Apparatus For Evaluating Infiltration Performance Of Filter Strips In Utah, Pranish Dahal

All Graduate Theses and Dissertations, Fall 2023 to Present

Stormwater from Utah’s roadways often carries pollutants such as oil, metals, and sediments, especially during small storms when runoff is not diluted. Vegetated filter strips—areas of soil and vegetation placed alongside roads—are one of the most effective ways to capture and clean this runoff before it reaches rivers and lakes. However, choosing the right combination of topsoil and base soil for these filter strips is difficult, expensive, and traditionally requires multiple field visits.

This thesis introduces a laboratory device that allows engineers to test how different soil combinations absorb and filter water without having to go to the field each …

Comparison Of Consumptive Use Of Furrow And Drip Irrigated Onions, Chad C. Withers

All Graduate Theses and Dissertations, Fall 2023 to Present

The State of Utah funded agricultural water optimization studies to determine how agricultural water depletion can be decreased while maintaining or improving yields. Conversion from surface irrigation to drip irrigation is investigated as a method to decrease consumptive use.

Some Utah onion producers are converting from furrow irrigation to drip irrigation to decrease water and fertilizer use and improve profits. This study compares the consumptive use and yield of three drip irrigated onion fields against the consumptive use and yield of three furrow irrigated onion fields.

Arrays of soil moisture sensors at various depths were placed in drip and furrow …

Numerical Investigation On Lightning Survivability And Residual Strength Of Scarf-Patched And Z-Pinned Cfrp Composites, Logan Hales

All Graduate Theses and Dissertations, Fall 2023 to Present

Carbon fiber reinforced polymer (CFRP) composites are critical in aerospace applications yet remain vulnerable to lightning strikes due to orthotropic electrical conductivity and poor thermal resistance. Over the past decades, lightning-strike damage in pristine CFRP has been extensively investigated. However, the response of damaged and subsequently repaired laminates remains poorly understood, raising concerns about the structural integrity of repaired aircraft. This study aims to develop a sequentially coupled thermo-structural modeling framework to quantify how two common composite repair strategies (scarf patching and z-pinning), along with patch size, pin material, and configuration, influence lightning-induced damage and the residual flexural strength of …

Reconfigurable Antennas Using Varactors On A Planar Parasitic Layer And Pin Diodes On A Dome Parasitic Layer, Andrew J. Hendricks

All Graduate Theses and Dissertations, Fall 2023 to Present

This research explores two types of reconfigurable, steerable antennas. These antennas change their beam direction based on electric input signals. The antennas have a layer that overlays the main antenna circuit board. The layer has small copper rectangles (pixels) that may be connected using either varactor diodes (which behave as voltage-controlled capacitors) or PIN diodes (electronic switches). The first antenna can steer in the xz-plane in any direction within about 23° from boresight (straight up from the antenna) and in the yz-plane to about 29° from boresight. The antenna uses varactor diodes on a planar layer. The second …

Design Of A Low-Power Magneto-Inductive Magnetometer, Rowan Antonuccio

All Graduate Theses and Dissertations, Fall 2023 to Present

Measuring magnetic fields in space helps scientists understand phenomena that can affect satellite communications and navigation systems on Earth. This research develops a new low-power magnetic field sensor for spacecraft that improves upon existing designs by moving the sensitive parts away from electrical interference and using energy-efficient digital electronics for precise measurements. The sensor’s power-efficient design is particularly important for small satellites, where power is limited and must be carefully managed. It will fly on future NASA missions to study disturbances in Earth’s upper atmosphere that can disrupt radio signals and GPS. This work contributes to our ability to better …

A Low Power Fpga Compute Array For Machine Learning And Artificial Intelligence Applications, Todd Wilson

All Graduate Theses and Dissertations, Fall 2023 to Present

Modern small satellites often lack the ability to analyze their data in real time, relying instead on downlinking raw measurements to Earth before any scientific interpretation can occur. This delay restricts missions that require rapid awareness of environmental or space-weather events. This thesis presents the Low-power Array for Cubesat Edge Computing Architecture, Algorithms, and Applications (LACE-C3A), a hardware platform designed to enable in-orbit data processing within the power and volume limits of CubeSat-class spacecraft. 

LACE-C3A uses a modular cluster of flash-based FPGAs, which offer low power consumption, radiation resilience, and in-flight reconfigurability. The system consists of a Controller board responsible …

Exploring Cognitive Load Theory In The Post-Secondary Engineering Classroom, Gabriel Q. Van Dyke

All Graduate Theses and Dissertations, Fall 2023 to Present

Engineering programs often emphasize subject-matter expertise over pedagogical training, which can leave students struggling with course demands and contribute to retention challenges. This study applied Cognitive Load Theory (CLT) to examine how undergraduate engineering students experience the cognitive demands of their coursework compared to non-engineering classes. Using a sequential explanatory mixed methods design, cognitive load surveys were followed by interviews to address two research questions: (1) What are the differences in intrinsic and extraneous cognitive load levels between engineering courses and non-engineering courses taken concurrently by undergraduate engineering students? (2) How do engineering students perceive the unique challenges or benefits …

Aerodynamic Parameter Estimation For A Scaled F-16: A Simulation-Based Sensitivity Analysis, Kathle C. Tischner

All Graduate Theses and Dissertations, Fall 2023 to Present

The physical motion of an aircraft is determined by the resulting forces and moments acting on the aircraft. These forces and moments can be defined as a mathematical equation where the control deflections, rotation rates, and orientation of the aircraft are multiplied by individual constants and summed together to define the entire force or moment. This method results in a highly accurate model that defines the motion of the aircraft at low angles of attack and sideslip. Initial calculations of the aerodynamic model are created based on analytical estimations based on the physical properties of the aircraft. Additional refinement of …

Engineered Uio-66-Nh2 Hybrid Nanocomposites For Antifouling Ultrafiltration Membranes With Dual Resistance To Microplastics And Protein Fouling, Mitra Golgoli, Mohadeseh Najafi, Javad Farahbakhsh, Masoumeh Zargar

Research outputs 2022 to 2026

The growing presence of microplastics (MPs) in water and their impact on ultrafiltration (UF) membranes during the early stages of wastewater treatment highlight the need for effective mitigation strategies. This study explores the innovative modification of UF membranes by incorporating various hybrid metal-organic frameworks (MOFs) nanoparticles, including UiO-66-NH2 hybrids with multi-walled carbon nanotubes (MWCNTs) (UiOM), chitosan (UiOC), and sulfobetaine zwitterions (UiOZ). These nanoparticles were synthesized and integrated into innovative UF membranes to compare their performance on MPs fouling effect in particular. The integration enhanced membrane hydrophilicity and altered surface roughness, creating a hydrophilic functional network that improved water permeability. Water …

Role Of Directional Conditional Filtering On Droplet Velocity And Size Distribution, Farzad Hossain, Matthew J. Cleary, Yasir M. Al-Abdeli, Mehdi Khiadani

Research outputs 2022 to 2026

This study investigates the role of directional filtering in the analysis of spray behaviour using two full cone nozzles (65° and 75°) emitting aqueous sprays under atmospheric conditions. A hybrid computational–experimental framework was applied, using Large Eddy Simulation (LES) with Discrete Phase Model (DPM) and Rosin-Rammler distribution in ANSYS Fluent, validated against Shadowgraph and Particle Image Velocimetry (PIV) measurements. The sensitivity of directional filtering to the effects of spray angle and flow rate (1.75 and 3.5 L/min), were also done. Upward-filtered droplets consistently exhibited greater breakup than both raw and downward-filtered data due to gravitational opposition and longer air exposure. …

Dynamic Mechanical Insertion Analysis Of Gelatin Methacryloyl Microneedles Under Realistic Insertion Conditions, Moloud Amini Baghbadorani, Masoumeh Zargar, Abdellah Shafieian, Majid Tolouei-Rad

Research outputs 2022 to 2026

Despite the great potential of Gelatin Methacryloyl (GelMA) microneedles (MNs) for minimally invasive drug delivery and interstitial fluid extraction, their performance under realistic insertion conditions and across diverse geometrical and mechanical parameters has remained uncharacterized. In this study, dynamic and static finite-element analyses were conducted for the first time to compare three types of crosslinked GelMA MNs: conical, pyramidal, and tapered-conical with and without base support. Insertion force, von Mises stress, and safety factors were evaluated at insertion velocities of 2-6 m/s under varying crosslinking times and polymer concentrations. The tapered-conical geometry demonstrated the best overall mechanical reliability, combining moderate …

3d-Printed Cf-Pla Bone Plates With Metamaterial Structures: Design, Fabrication, And Mechanical Evaluation, Ani Daniel, Hamed Bakhtiari, Alireza Nouri, Barun K. Das, Muhammad Aamir, Majid Tolouei-Rad

Research outputs 2022 to 2026

This study presents the design, fabrication, and mechanical performance of carbon fiber-reinforced polylactic acid (CF-PLA) bone plates incorporating auxetic and non-auxetic metamaterial architectures. Four lattice-structured bone plates (re-entrant, rotating square, tetrachiral, and hexagonal) were evaluated for their flexural, tensile, and compressive properties. The specimens were fabricated using Fused Deposition Modelling (FDM). The tetrachiral structure demonstrated superior bending capacity, achieving a flexural stress of 17 MPa and a modulus of 1214 MPa. Under both tension and compression, it exhibited the highest strength (24.5 MPa and 40 MPa, respectively) and stiffness (1441 MPa in tension and 2352 MPa in compression), while the …

Dynamic Load Assessment Of Pem Fuel Cell Systems Under Pid-Based Control Strategies For Sustainable Operation, Tarek Abedin, Paw, Normy Norfiza Abdul Razak, Chen Chai Phing, Yaw Chong Tak, Monowar Mahmud, Manzoore Elahi M. Soudagar, T. M. Yunus Khan, Mohammad Tariqul Islam, Mohammad Nur-E-Alam

Research outputs 2022 to 2026

Proton exchange membrane fuel cell (PEMFC) systems’ reliable operation under variable load conditions is a significant challenge because of voltage fluctuations, transient variations, and the high computational requirements of sophisticated control techniques like intelligent and model predictive controllers. Even while these state-of-the-art methods provide great precision, complexity and cost often limit their real-time applicability, underscoring the need for a simpler but efficient control solution. To achieve effective voltage regulation in PEMFC systems, this study suggests a DC–DC buck converter in conjunction with a comparator-based proportional–integral–derivative (PID) control technique. In order to provide stable operation under both constant and changing load …

Comparative Fatigue Analysis Of Cf-Pla Metamaterial Bone Plates For Orthopaedic Fixation, Ani Daniel, Hamed Bakhtiari, Barun K. Das, Muhammad Aamir, Majid Tolouei-Rad

Research outputs 2022 to 2026

Bone plates are widely used in orthopaedic surgery to stabilise fractured bones and support healing following traumatic injuries or osteotomies. However, conventional metallic bone plates suffer from stress shielding and stiffness mismatch with bone, which can hinder optimal healing. Additive manufacturing enables the incorporation of novel metamaterial architectures into polymer-based implants to enhance mechanical properties. The fatigue behaviour of these implants during the healing period is critical to ensuring their structural integrity and long-term performance. In this study, the compressive fatigue performance of fused deposition modelling (FDM)-printed carbon fibre-reinforced polylactic acid (CF-PLA) bone plates were investigated. Four metamaterial structures—tetrachiral, re-entrant, …

Implementation Of Kansei Engineering Method In Designing Spreadable Cheese Packaging, Novi Purnama Sari, Mega Analisa, Suci Puji Lestari, Khofifah Nur Amalia

Makara Journal of Technology

Some spreadable cheese packaging uses flexible plastic without additional features and easily damaged boxes. This packaging causes several problems, such as difficulty in re-storage, loss of product information due to damaged box packaging, wasteful use of packaging materials, and making the product less hygienic. The purpose of this study is to develop packaging that focuses on consumer emotions. The packaging was developed using the Kansei Engineering method, supported by Principal Component Analysis (PCA) as a determinant of the design concept, and Quantification Theory Type 1 (QTT1) to identify design elements. This study produced 46 packaging samples and 40 Kansei words. …

Picc-Pal: A Support Band For Independent Picc Line Use, Kylie Luker

Honors Theses

This project presents the design and evaluation of PICC-PAL, a wearable assistive device intended to improve independence and usability for patients managing peripherally inserted central catheters (PICC lines) at home. Current at-home PICC line management often requires help due to the fine motor skills needed to connect and secure tubing. This increases reliance on caregivers and introduces potential risks such as infection and dislodgement. Through stakeholder analysis, prior art evaluation, and iterative prototyping, a device was developed to stabilize the PICC line lumen and enable one-handed connection of medical tubing. Throughout the project, multiple design concepts were explored, with the …

Optimization Of Renewable Energy-Based Alkaline Electrolysis Systems For Sustainable Hydrogen Production, Shokhrukhbek Kozimjon Ugli Bakhramov

Chemical Technology, Control and Management

This paper presents a comprehensive optimization study of hydrogen production systems through alkaline water electrolysis powered by photovoltaic energy sources, with a specific focus on Central Asian applications. The research systematically investigates critical operating parameters including KOH electrolyte concentration (25-30 wt%), temperature effects (25-80°C), current density optimization (100-500 mA/cm²), and electrode material performance using cost-effective 316L stainless steel. Experimental results demonstrate that optimized systems achieve solar-to-hydrogen efficiency of 13-15%, with hydrogen production costs ranging from $2-8/kg depending on system scale. The study reveals that maximum performance occurs at 30 wt% KOH concentration, 60-80°C operating temperature, and 200-400 mA/cm² current density. …

Using Ali-4 Z-Implication In Controller Design, Shamil Azer Ahmadov

Chemical Technology, Control and Management

One of the widely used theories in the information processing is Professor Zadeh's fuzzy logic theory. Fuzzy implications form the basis of this theory. When processing information using fuzzy implication, the chosen judgment method and the type of implication affect the result. Referring to the review of the relevant literature on fuzzy implications, it can be noted that there are still unresolved problems and issues. For example, fuzzy implications cannot be used in processing imperfect information or information based on probabilistic and fuzzy uncertainty. Existing fuzzy implications face limitations in practical applications. Fuzzy implications only take into account inaccuracy, but …