Engineering Commons^™

Improving Future Vehicle Fuel Economy And Operational Design Domain Through Novel Data Pipelines, Kyle James Carow

Masters Theses

Modern automobiles have greatly advanced in recent years, with technological developments that enhance performance, safety, and comfort. However, there is still much room for improvement. Today’s vehicles are heavily reliant on the combustion of fossil fuels, proven to be harmful for the environment on both a local and global scale. In addition, the safety benefits of autonomous vehicles and advanced driver assistance systems are not yet fully realized due to the limited operational design domain of these technologies. In this research, these needs are addressed through the development of two novel data pipelines. In the first study, a novel methodology …

Healthcare Disparities Among Incarcerated Populations: A Quality Improvement Project, Mariam Bradley, Morgan Callihan, Sandra Frederick, Riley Hall, Marty Helms, Aaliyah Manson, Katelyn Martha, Madison Mason, Suzi White

2023 Celebration of Student Scholarship - Poster Presentations

A population that has been consistently subject to unequal treatment when receiving medical attention is the population of prisoners or jail inmates. It is essential to explore the discrepancies prisoners face and the effects it has on their health. The objective of this research was to bring to light the disparities incarcerated patients experience, and how to eliminate these. In order to develop a better understanding of the prejudiced actions incarcerated patients face in the healthcare spectrum, numerous studies have been analyzed.

Are Gender And Social Disparities Associated With Stem Persistence In Kentucky Colleges?, Riley E. Hicks, Wilson Gonzalez-Espada

2023 Celebration of Student Scholarship - Poster Presentations

Children have the right to receive a quality education, but concerns about county disparities in school funding, facilities, and resources exist. This is known as the "zip code effect". Because high school STEM classes require lab space, materials, equipment, and specialized teachers, disparities in school funding can impact students who want STEM careers.

Visual Pollution Classification Using Convolutional Neural Networks, Jacob Vogelpohl, Heba Elgazzar

2023 Celebration of Student Scholarship - Poster Presentations

Visual pollution is an impairment on an individual's ability to enjoy their surroundings. It usually takes the form of a messy and chaotic environment that can cause overstimulation of the visual senses. This includes trash, advertisements, construction, electric cables, and similar objects. Convolutional Neural Networks (CNNs) are a form of artificial intelligence that use supervised learning to process and classify images. In this research, a CNN processed images of city streets and classified them as polluted or not polluted based on the visual characteristics that it learned from during its training period. The CNN achieved a training accuracy of 98% …

Predicting The Mechanism And Products Of Cs2 Capture By Nh3 - An Exemplar Benchmark Study, Shelbie A. Black, David A. Dixon, Zachary R. Lee

2023 Celebration of Student Scholarship - Poster Presentations

Carbon disulfide is a toxic gas emitted from industrial plants and a common greenhouse gas. Acute poisonings from carbon disulfide are rare, but recurring exposure to low doses can have long term health effects. Currently, there are two approaches being considered for the removal of acid gas pollutants: (1) sequester these gases from the atmosphere or (2) remove these gases directly upon combustion (post-combustion). Potential energy surfaces (PES) for a series of CS2 capture reactions by NH3 in the presence H2O were calculated at the MP2/a(D+d) evel in the gas phase. G3(MP2) and FPD calculations are in progress. Extensive thermodynamic …

Quantifying The Impact Of Reclaimed Asphalt Pavement On The Skid Resistance Of Surface Mixtures, Sheng Hu, Fujie Zhou, Tom Scullion, Emmanuel Fernando, Mena I. Souliman

Civil Engineering Faculty Publications and Presentations

Pavement skid resistance is critical for public safety, especially in wet-weather conditions. In Texas, as the population grows and the likelihood of wet-surface crashes and fatalities increases, the use of Surface Aggregate Classification A (SAC-A) aggregate has significantly increased each year to improve pavement skid resistance. Texas Department of Transportation specifications allow for the use of reclaimed asphalt pavement (RAP) to conserve natural resources and save costs. However, the impact of RAP on the skid resistance of the surface mixture was unknown or not quantitatively studied. Currently, all RAPs are categorized as Surface Aggregate Classification B aggregate in Texas. This …

Computational Design Of Fiber-Optic Probes For Biosensing, Suwarna Karna

Electrical Engineering Theses

This thesis presents a study on the optical characteristics of hollow-core photonic crystal fibers (HC-PCFs) with a band gap cladding structure and their applications in optical fiber sensing. This 800B HC-PCF exhibited excellent optical properties and has a flexible structure, which makes them suitable for a wide range of industrial applications. Finite element simulations and structural optimization designs were conducted using the surface plasmon resonance (SPR) technique to determine the optimal performance parameters of the 800B HC-PCF. The fiber was further modified using the SPR technique to improve its practical detection capabilities. The performance of the modified fiber was observed …

Droplet Capture In A Fiber Array, Karl Cardin, Christophe Josserand, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Droplets interacting with fiber arrays is ubiquitous in nature, textiles, microelectromechanical devices, and fog harvesting. The phenomena of droplet impact on an equidistant array of fibers is experimentally investigated. Drop tower tests are performed to characterize the droplet dynamics in the absence of the effects of gravity which could deform fibers and bias equilibrium configurations. Results show that contact line dissipation is largely responsible for arresting the droplet. Additionally, the penetration length is affected by fiber flexibility. A model is developed predicting the droplet penetration dynamics which shows good agreement with experiments.

Spectroscopic Sensor Data Fusion To Improve The Prediction Of Soil Nutrient Contents, Bidhan Ghimire

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

This study aims to advance the understanding and application of spectroscopic sensor data fusion for improving soil nutrient content predictions. In addition to presenting an extensive review of studies on the spectroscopic sensor data fusion, a research investigation was conducted to assess the effectiveness of five fusion algorithms in predicting three primary nutrients (Nitrogen, Phosphorous, and Potassium) and two secondary nutrients (Calcium and Magnesium) in soil using Visible and Near-Infrared, Mid-Infrared, and X-ray Fluorescence data. Among the five fusion algorithms, one was a low-level fusion involving data concatenation. Two were mid-level fusions, incorporating feature extraction by applying (i) Principal Component …

Estimating Crop Stomatal Conductance Through High-Throughput Plant Phenotyping, Junxiao Zhang

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

During photosynthesis and transpiration, crops exchange carbon dioxide and water with the atmosphere through stomata. When a crop experiences water stress, stomata are closed to reducing water loss. However, the closing of stomata also negatively affects the photosynthetic efficiency of the crop and leads to lower yields. Stomatal conductance (gs) quantifies the degree of stomatal opening and closing by using the rate of gas exchange between the crop and the atmosphere, which helps to understand the water status of the crop for better irrigation management. Unfortunately, gs measurement typically requires contact measuring instruments and manual collection in the field, which …

Characterization Of Physical And Biochemical Traits In Wheat And Corn Plants Using High Throughput Image Analysis, Kantilata Thapa

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Plant phenotyping has been recognized as a rapidly growing field of research due to the labor-intensive, destructive, and time-consuming nature of traditional phenotyping methods. These phenotyping bottlenecks can be addressed by advancements in image-based phenotyping like RGB and hyperspectral imaging for the assessment of plant traits important for breeding purposes. This study aims (1) to characterize the physical and biochemical traits of wheat and corn plants using RGB and hyperspectral imaging in the greenhouse, and (2) to estimate leaf nitrogen (N), phosphorus (P), and potassium (K) content using hyperspectral imaging and an analytical spectral device (ASD spectrometer) and compare the …

Jpl Robotic Avionics & Sensor Kit (Rask), John Helzer

Honors Program: Senior Projects (Public)

No abstract provided.

Loss Of Control In-Flight (Loc-I): A Mixed Methods Study Of Voluntary Versus Mandatory Reports From The United States Of America, Roger Lee

Doctoral Dissertations and Master's Theses

Loss of control in flight (LOC-I) is one of modern aviation’s three most prominent fatal accidents. In the United States, air accidents are mandatorily reported to and investigated by the National Transportation Safety Board (NTSB). Established in 1976, the Air Safety Reporting System (ASRS) is a voluntary safety reporting (VSR) system administered by the National Aeronautics and Space Administration (NASA). Over 1.7 million ASRS reports have been processed to date. While the NTSB system handles LOC-I accidents, less severe incidents may have been reported voluntarily through the ASRS.

Safety reporting has been deemed the most valuable activity and the centerpiece …

The Influence Of In-School Time (Ist) And Out-Of-School Time (Ost) Learning Experiences On Aviation Career Entry, Andrew Koch

Doctoral Dissertations and Master's Theses

Increased demand for aviation has created a skill and workforce gap. An understanding of how to increase this potential workforce is vital to ensure the ongoing success and sustainability of the commercial aviation industry. This research explores science, technology, engineering, and math (STEM) programs as a potential avenue for increasing the available aviation workforce. Specifically, it explores how STEM programs and their associated learning experiences influence career entry.

Utilizing a mixed methodology approach, this research retrospectively explored the self-reported effect of out-of-school time (OST) and in-school time (IST) STEM experiences on aviation career development. Through interviews, a survey instrument was …

Writing Matters: Investigating The Quality Of Collegiate Aviation Incident Report Narratives, Kayla D. Taylor

Doctoral Dissertations and Master's Theses

Strong communication skills are fundamental to workplace success in the field of aviation. Numerous studies have shown that a deficiency in communication skills contributes to aviation accidents, and, as a result, the development of communication competencies within the aviation industry has received considerable critical attention. Understanding the acquisition and subsequent progression of writing skills throughout a pilot’s education, specifically in preparatory aviation courses, is an emerging area of research in aviation communication.

This study examined how the level of supplemental discipline-specific guidance affects the writing quality of incident report narratives composed by collegiate pilot students at Embry-Riddle Aeronautical University (ERAU). …

The Role Of Slip System Activation On Ni-Based Superalloy High Temperature Fatigue, Alexandru Lopazan

Doctoral Dissertations and Master's Theses

Nickel-based superalloys are used extensively in the aviation industry, particularly in aircraft engine components. These materials are desirable due to their high strength, resistance to creep, corrosive environment, and high temperature. It has been well documented that material fatigue is characterized by material microstructure, type of loading, and other parameters. Currently, research into the effects of fatigue on complex materials like nickel-based superalloys is being pursued. Previous research has found that preconditioning of Inconel 718 samples at 700 ℃ with 1.0% strain led to an improved fatigue life. It has been suggested that this could be caused by the activation …

Small Unmanned Aircraft Systems: Operator Workload And Situation Awareness Utilizing First Person View Techniques, Ross Lucas Stephenson Jr

Doctoral Dissertations and Master's Theses

The small, unmanned aircraft systems (sUAS) sector within the aviation industry is experiencing unprecedented growth. However, the regulatory guidance for the safe integration of sUAS into the National Airspace System (NAS) has not kept pace with this technological growth within the market. Current regulatory limitations of line-of-sight operations may have an impact on the establishment of an equivalent level of safety for sUAS operations as maintained by manned aircraft. The focal point of the discussion of line-of-sight operations has been the ability of the sUAS pilot to see and avoid all obstacles and other aircraft in a safe and timely …

Thermal Boundary Condition Effects On Local Supercritical Co2 Heat Transfer Trends In Tubes, Nicholas C. Lopes

Doctoral Dissertations and Master's Theses

Supercritical carbon dioxide (sCO2) is a promising heat transfer fluid for the refrigeration and power generation industries due to its unique thermal properties and low environmental impact. To understand it as an alternative to traditional working fluids, the thermophysical and heat transfer phenomena of sCO2 are often studied using simplified geometries (tubes). Focus has been placed on investigating averaged heat transfer trends under an array of flow conditions with either a constant wall heat flux, constant wall temperature, or conjugate thermal boundary condition. Less emphasis has been placed on studying local sCO2 heat transfer developments. Tubular sCO2 numerical models that …

A Simulation Of The Impacts Of Climate Change On Civil Aircraft Takeoff Performance, Thomas D. Pellegrin

Doctoral Dissertations and Master's Theses

Climate change affects the near-surface environmental conditions that prevail at airports worldwide. Among these, air density and headwind speed are major determinants of takeoff performance, and their sensitivity to global warming carries potential operational and economic implications for the commercial air transport industry. Previous archival and prospective research observed a weakening in headwind strength and predicted an increase in near-surface temperatures, respectively, resulting in an increase in takeoff distances and weight restrictions. The main purpose of the present study was to update and generalize the extant prospective research using a more representative sample of worldwide airports, a wider range of …

Experimental And Numerical Analysis Of A Commercial Phase Change Material Melting At Different Inclinations, Andrew Heiles

Doctoral Dissertations and Master's Theses

The study of various phase change materials (PCM), experimentally and numerically, have been completed over the past several years to address their feasibility and potential when used in latent heat thermal energy storage (LHTES) systems for a variety of potential applications. Previous studies have investigated changes into the type of PCM used in the system as well as the system configuration, ranging from boundary conditions to internal and external geometries and orientations of the system. The present study focused on conducting experiments at different inclination angles and isothermal wall temperatures with the organic PCM PureTemp37, and continued with a numerical …

Assessing High Dynamic Range Imagery Performance For Object Detection In Maritime Environments, Erasmo Landaeta

Doctoral Dissertations and Master's Theses

The field of autonomous robotics has benefited from the implementation of convolutional neural networks in vision-based situational awareness. These strategies help identify surface obstacles and nearby vessels. This study proposes the introduction of high dynamic range cameras on autonomous surface vessels because these cameras capture images at different levels of exposure revealing more detail than fixed exposure cameras. To see if this introduction will be beneficial for autonomous vessels this research will create a dataset of labeled high dynamic range images and single exposure images, then train object detection networks with these datasets to compare the performance of these networks. …

Impact Resistance Of Hybrid Metal-Organic Frameworks/Carbon Fibers Composites, Derek Isaac Espinosa Ramirez

Doctoral Dissertations and Master's Theses

The increase in the use of carbon fiber-reinforced polymers (CFRPs) composites in the aerospace industry generated the need of improving the properties and capabilities of these composites by adding nano-reinforcements to the carbon fibers, also called hybrid fiber reinforced polymer composites. In this study, the energy absorption due to impact at low speed will be tested and simulated in four configurations of CFRPs utilizing the same [0/90]_S layout throughout them.

The carbon fiber configurations used during this study are de-sized, acid-activated, metal-organic frameworks (MOF), and carbon nanotubes (CNTs). Nickel (II) Nitrate, Methylimidazole, and Methanol were used to grow the …

Enhancing Cyberspace Monitoring In The United States Aviation Industry: A Multi-Layered Approach For Addressing Emerging Threats, Matthew Janson

Doctoral Dissertations and Master's Theses

This research project examined the cyberspace domain in the United States (U.S.) aviation industry from many different angles. The research involved learning about the U.S. aviation cyberspace environment, the landscape of cyber threats, new technologies like 5G and smart airports, cybersecurity frameworks and best practices, and the use of aviation cyberspace monitoring capabilities. The research looked at how vulnerable the aviation industry is from cyber-attacks, analyzed the possible effects of cyber-attacks on the industry, and suggests ways to improve the industry's cybersecurity posture. The project's main goal was to protect against possible cyber-attacks and make sure that the aviation industry …

Additive Manufacturing For Phase Change Thermal Energy Storage And Management, Thomas B. Freeman

Doctoral Dissertations and Master's Theses

Phase change materials can enhance the performance of energy systems by time shifting or reducing peak thermal loads. Certain electronic devices such as batteries, laser systems, or electric vehicle power electronics are highly transient and require pulse heat dissipation. Heat sinks, or thermal management devices made of a phase change material can absorb large heat spikes while maintaining a constant temperature. Additive manufacturing techniques hold tremendous potential to enable co-optimization of material properties and device geometry, while potentially reducing material waste and manufacturing time. Recently, a few efforts have emerged that employ additive manufacturing techniques to integrate a phase change …

Numerical Modeling Of Synthetic Vortical Disturbance Interactions Using Openfoam, Ahmed Bilal

Doctoral Dissertations and Master's Theses

Nowadays, the number of Advance Air Mobility (AAM) Electic Vertical Take-off and Landing (eVTOL) concepts is rapidly increasing due to their capability of vertical take-off and landing at vertiports located on rooftops of tall urban buildings, which does not require using the ground space in a condensed urban environment. Such flight operations, however, will be greatly affected by the vertiport’s highly unsteady, turbulent flow environment. The goal of this study is to model the turbulent wind interaction with a building to understand the unsteady flow characteristics around vertiports and match the induced unsteady disturbance field to the canonical disturbance forms, …

Nonlinear Dynamics Analysis And Control Of Space Vehicles With Flexible Structures, Marco Fagetti

Doctoral Dissertations and Master's Theses

Space vehicles that implement hardware such as antennas, solar panels, and other extended appendages necessary for their respective missions must consider the nonlinear rotational and vibrational dynamics of these flexible structures. Formulation and analysis of these flexible structures must account for the rigid-flexible coupling present in the system dynamics for stability analysis and control design. The system model is represented by a flexible appendage attached to a central rigid body, where the flexible appendage is modeled as a cantilevered Euler-Bernoulli beam. Discretization techniques, such as the assumed modes method and the finite element method, are used to model the coupled …

Utilizing Flight Data Monitoring At A Part 141 Flight School To Determine Predictors For Unstabilized Approaches And Go-Arounds, Hannah Rooney

Doctoral Dissertations and Master's Theses

As general aviation accident rates are much higher than those of Part 121 air carriers, and the approach and landing phase of flight accounts for more accidents than any other phase of flight, the study of the approach and landing phase of flight is warranted in greater detail. Flight Data Monitoring provides an excellent source of data for the study of individual landing parameters. The intent of this study was to evaluate potential predictors of unstable approaches as well as go-arounds.

Flight data provided by a Part 141 flight school was examined to determine predictors for unstable approaches and go-arounds. …

The Linearized Euler Equations For Predicting Supersonic Jet Noise Of A Rectangular Jet Using Openfoam, Patrick Good

Doctoral Dissertations and Master's Theses

This thesis presents a Linearized Euler Equation (LEE) solver that was developed for OpenFOAM. OpenFOAM is an open-source Computational Fluid Dynamics (CFD) package that is widely used by industry and academia. The LEE’s are a set of equations used in Computational Aeroacoustics (CAA). The LEE’s can solve for the acoustic solution directly and quickly. The solver developed, named leeFoam, was tested against analytical solutions to verify accuracy and then was utilized to predict the acoustics of a heated supersonic rectangular jet. The rectangular jet (RJET) results were compared against experimental data.

The results from this work show that OpenFOAM can …

Defining Safe Training Datasets For Machine Learning Models Using Ontologies, Lynn C. Vonder Haar

Doctoral Dissertations and Master's Theses

Machine Learning (ML) models have been gaining popularity in recent years in a wide variety of domains, including safety-critical domains. While ML models have shown high accuracy in their predictions, they are still considered black boxes, meaning that developers and users do not know how the models make their decisions. While this is simply a nuisance in some domains, in safetycritical domains, this makes ML models difficult to trust. To fully utilize ML models in safetycritical domains, there needs to be a method to improve trust in their safety and accuracy without human experts checking each decision. This research proposes …

Characterization Of Bistability Behavior In Unsymmetric Cfrp Laminates, Evan Medora

Doctoral Dissertations and Master's Theses

Composite laminates of unsymmetric layup families often exhibit twin stable shapes at room temperature, a phenomenon known as bistability. Unsymmetric bistable composite laminates have often been suggested for applications in aerospace morphing structures, damping, and energy storage, because of their ability to easily change their shape while being homogenized with the rest of the composite structure.

This study analyzes the mechanisms responsible for bistability in unsymmetrical [0/0/90/90] laminates through a combination of experiments and modeling. Several unsymmetrical laminates with different aspect ratios were fabricated using autoclave processing. Digital image correlation (DIC) is used to monitor laminate strains in situ during …