Digital Commons Network^™

Simplified Molecular Diagnostics Methods For Environmental Testing Of Pathogens And Other Applications, Mohammad Dehghan Banadaki

Theses and Dissertations--Mechanical and Aerospace Engineering

Environmental Surveillance (ES) has emerged as a powerful tool to monitor the emergence and persistence of a pathogen within a facility or community using wastewater/water analysis. Over the past four years, implementation of ES has experienced an explosive acceleration, driven by efforts to monitor the spread of SARS-CoV-2, which has made ES a routinely used public health tool in many locations. We can now use ES to measure the emergence/presence/abundance of different viruses (e.g., SARS-CoV-2, influenza, mpox), bacteria (e.g., E. coli, V. cholerae, antibiotic-resistant strains), fungi (e.g., C. auris), and other biological markers indicative of infectious diseases. However, its broad …

Determination And Limitations Of Blocked Forces In Industrial Settings, Matthew Smither

Theses and Dissertations--Mechanical and Aerospace Engineering

Transfer path analysis methods have been used for decades to determine noise and vibration paths emanating from machinery. In its advent, the machinery source had to be disconnected from the receiver it was attached to in order to gain useful information about each. Further advances in methodology allowed for determining machinery input forces without decoupling them from the structures they were attached to. However, these methods were limited in that the machinery and structures were required to be treated as a system. Thus, any force data obtain was only useful in the configuration it was measured in. Finally, a method …

In-Situ Characterization Of Damage Mechanisms In Ceramic Matrix Composites, Cle' E. Sanchez

Theses and Dissertations--Mechanical and Aerospace Engineering

Ceramic Matrix Composites have many advantages, attracting the nuclear, aerospace, and automotive industries with their high heat stability, strength, and oxidation resistance. However, challenges are presented when machining these materials due to the brittle properties and complicated microstructure. The objective of this project was to identify damage mechanisms that occur when a CMC is orthogonally machined and the cutting mechanics are observed in-situ, followed by post-cut characterization of the as-machined surface morphology. In this analysis, the main variable is the feed rate, which can influence the damage mechanisms, such as matrix failure (matrix cracking) or fiber failure (pullout). Through this …

In Situ Bourbon Barrel Measurements Of Alcohol By Volume And Liquid Depth Using Borosilicate Glass Probes And Near Infrared Absorption Spectroscopy, Trent T. Reed

Theses and Dissertations--Mechanical and Aerospace Engineering

In pursuit of measuring different variables present in bourbon barrels, absorption spectroscopy was utilized to ensure that different ethanol and water concentrations can be differentiated using a broadband light source and near infrared spectrometer in a simple cuvette-based testing setup. The intensity and absorption plots gathered of different ethanol and water mixtures were then analyzed using proper orthogonal decomposition (POD) to break down the data into modes which represent specific variables of interest, specifically ethanol concentration or alcohol by volume (ABV). The modes were then utilized to find mode constants to represent the data taken from cuvette samples which were …

Numerical Investigation Of Wind Disturbance Around A Multirotor Uav In Crosswind And Vertical Flight, Garrison Page

Theses and Dissertations--Mechanical and Aerospace Engineering

Uncrewed Aerial Vehicles (UAVs) are being increasingly utilized in a wide range of research applications, especially in meteorology. This is due to such factors as their ease of use, maneuverability compared to other forms of data collection, and for rotor- craft, the ability to hover. However, the rotorwash generated by UAVs can introduce significant disturbances, potentially affecting measurement accuracy from sensors. While several studies have investigated the rotorwash of individual UAVs utilizing Particle Image Velocimetry (PIV) and Computational Fluid Dynamics (CFD), there is limited exploration into how different rotor configurations and external wind conditions influence regions of turbulent flow around …

Growth Kinetics And Stability Of Metal Halide Perovskite Nanocrystals: Influence Of Stirring Speed And Water Exposure, You-Lin Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Cesium lead bromide (CsPbBr₃) perovskite nanocrystals (NCs) have garnered significant interest due to their exceptional optoelectronic properties, including high photoluminescence quantum yield, tunable bandgap, and excellent carrier dynamics. These attributes make them promising candidates for applications in light-emitting diodes, photovoltaics, and sensing technologies. However, optimizing their synthesis and improving their environmental stability remain critical challenges. This dissertation explores the growth kinetics of CsPbBr₃ NCs, focusing on the effects of stirring speed and water exposure on their structural and optical properties.

The synthesis of CsPbBr₃ NCs was performed using both mechanochemical (MC) and antisolvent methods, enabling an …

Acoustic Characterization Of A Quadcopter Using A Test Stand, Jared Schmal

Theses and Dissertations--Mechanical and Aerospace Engineering

Unmanned Aerial Vehicles (UAVs) with multirotor propulsion and control, commonly called drones or multicopters, generate a complex acoustic field that is not entirely understood. Many components and their interactions contribute to the overall noise level and behavior of the acoustic field. However, performing acoustic measurements on a multicopter in a confined space, such as a small anechoic chamber, can be an extremely difficult and time-consuming process. A test stand was developed to allow for rapid and safe acoustic measurements in a controlled environment. The design, development, and initial measurements are discussed. The performance and acoustic response are assessed to examine …

Analysis Of Closed-Loop Dynamical Systems Using Relu Nns, Pouya Samanipour

Theses and Dissertations--Mechanical and Aerospace Engineering

This thesis develops a framework for analyzing the stability and invariance properties of closed-loop dynamical systems whose dynamics are derived from neural networks with rectified linear units (ReLUs). The ReLU neural network defines continuous piecewise affine (PWA) functions, which makes them ideal for analysis using polyhedral geometry and optimization techniques. To begin, we introduce two exact algorithms for enumerating polytopic regions of affine behavior induced by ReLU networks: a half-space-based method that checks the feasibility of activation patterns and a geometric vertex-based method. Using these methods, we are able to perform precise region-wise analysis, and these methods serve as the …

In-Situ Informed Modeling And Characterization Of Friction And Built-Up Edge In Machining Of Aerospace Alloys, Avery Hartley

Theses and Dissertations--Mechanical and Aerospace Engineering

Machining is by no means a new manufacturing process. However, it is separated from other traditional deformation processes by its extreme temperatures and strain rates. The function and life of a multitude of products and mechanical components are dependent on the material properties induced by changing the surface through machining. Furthermore, the tools used within machining are often expensive and material reserves are sparse. The understanding the mechanics of the machining process, especially related to the friction of the tool and workpiece, helps to further the life of tools and parts to minimize economic and environmental impact.

Current friction modeling …

Engineering A Novel Solvent Regenerator That Leverages Electrochemically Induced Ph Swings For Direct Air Capture And Hydrogen Generation, Emmanuel Aluhunmile Ohiomoba

Theses and Dissertations--Mechanical and Aerospace Engineering

Direct Air Capture (DAC) is considered to be a key component for achieving global net-negative emissions. However, to capture CO₂ at the low concentrations in the atmosphere requires materials with high affinity for CO₂. This makes the solvent-based chemical approach for DAC more applicable compared to physical approaches. Nonetheless, regenerating the capture solvent presents a significant challenge due to high heat requirements for thermal decomposition of carbonates. Leveraging electrochemical principles provides an opportunity to simplify the regeneration process, thus, this work focuses on engineering an electrochemical solvent regenerator for recovering alkaline solvents for DAC, with co-production of …

Machining-Induced Residual Stress Modeling Using Physics-Informed Neural Networks, Md Mehedi Hasan

Theses and Dissertations--Mechanical and Aerospace Engineering

Process-induced residual stress (RS) plays a critical role in determining the structural integrity, fatigue life, corrosion resistance, and dimensional stability of manufactured components. Tensile residual stress can be harmful to the machined workpiece by lowering fatigue strength, while compressive residual stress helps to prevent such issues. Therefore, accurate prediction and control of machining-induced residual stresses are essential for optimizing manufacturing processes and enhancing component performance. However, existing modeling approaches—empirical, analytical, and numerical—often have limited predictive accuracy, demand extensive calibration, or involve high computational costs. Traditional finite element analysis (FEA) provides modeling insights but is constrained by its high computational cost …

Scaling Investigations Of Wall-Bounded Turbulent Flow, Nikolay Gustenyov

Theses and Dissertations--Mechanical and Aerospace Engineering

This dissertation investigates the scaling behavior, structural organization, and modeling of turbulence in wall-bounded flows across a wide range of Reynolds numbers and surface conditions. Through high-resolution experimental studies in zero-pressure- gradient turbulent boundary layers and pipe flows (2000 < Reτ < 38 200), the wall- dependence of turbulent length scales is examined with a focus on both small-scale dissipative motions and large-scale structures. When external intermittency is properly accounted for, dissipative motions are shown to obey inner scaling even in outer- scaled regions, while large-scale motions exhibit outer scaling behavior deep into the inner region. These findings are consistent across internal (pipe) and external (boundary layer) flows and are reflected in distinct features of the longitudinal wavenumber spectrum.

The dissertation also explores the development of a turbulent boundary layer transitioning from a smooth solid wall to a liquid surface. An internal boundary layer forms in response to stochastic surface waves, resulting in increased turbulence intensity and displaced momentum relative to solid-wall cases. Near the liquid surface, turbulence generation aligns with wavenumbers corresponding to the surface waves, introducing distinct small-scale …

Development Of An Immersed Boundary Method-Wall Modeled Large Eddy Simulation Approach For Incompressible Flows And Aeroacoustic Predictions, John C. Higgins

Theses and Dissertations--Mechanical and Aerospace Engineering

The performance capabilities of rotorcraft have improved significantly in the past decade as both manned and unmanned rotorcraft become a larger part of future transportation systems. Private companies as well as various government offices have worked to develop capabilities ranging from transportation/package delivery to intelligence/surveillance to livestock monitoring. Their practicality in both rural and urban areas, however, is questionable due to the significant tonal and broadband noise which is produced by the rotors. Public acceptance of rotorcraft, namely small Unmanned Aerial Vehicles (sUAVs), in transportation systems is an issue largely associated with the noise generation and it's effect on nearby …

Fluid Pathways For Enhanced Mass Transfer In The Micro Regime: Applications In Novel Pumpless Redox Flow Cell And Zinc Finger Protein-Based Dna Detection, Shaikh Al Mahmud Bhuiyan

Theses and Dissertations--Mechanical and Aerospace Engineering

Precise fluid transport through microscale geometries can help optimize electrochemical and biochemical processes by maximizing the mass transfer rate of reactants. By introducing intricate structural features inside microchannels, it is possible to manipulate the fluid motion and direct the flow towards any surface of interest. In this study, we have demonstrated that rationally designed fluid pathways can improve the performance of electrochemical and biochemical systems.

The emergence of additive manufacturing has enabled rapid fabrication of robust structures with intricate features to guide fluid motion. However, their application in nonaqueous electrochemical systems has been limited due to their interaction with organic …

Direct Numerical Simulation Of Pulsating Flow In Curved Pipes: Insights Into Aortic Dissection In Humans, Gokul Anugrah Gopakumar

Theses and Dissertations--Mechanical and Aerospace Engineering

This dissertation investigates the hemodynamics of pulsating blood flow in curved vessels through direct numerical simulations (DNS), with the overarching aim of uncovering fluid dynamic mechanisms linked to the onset and progression of aortic dissection in humans. The work is structured in two parts: (i) fundamental studies in idealized geometries and (ii) preliminary investigations in patient-specific anatomies. In the first part, curved pipe models representing the aortic arch are used to isolate the effects of pulsation frequency, amplitude ratio, and curvature ratio on transitional and turbulent flow dynamics. The simulations reveal that curvature-driven centrifugal forces shift the peak velocity toward …

High-Altitude Balloon-Launched Uncrewed Aircraft System Measurements Of Atmospheric Turbulence And Qualitative Comparison With Infrasound Microphone Response, Anisa Haghighi

Theses and Dissertations--Mechanical and Aerospace Engineering

This study explores the use of a balloon-launched uncrewed aircraft system (UAS) to measure atmospheric turbulence in the troposphere and lower stratosphere using both wind velocity measurements and infrasonic acoustic energy. The UAS, a glider configured for autonomous descent along a predefined trajectory, had on board, in situ sensors to capture thermodynamic and kinematic atmospheric parameters. Additionally, it carried an infrasonic microphone to evaluate its potential for remotely detecting clear-air turbulence by capturing infrasonic waves. The system’s performance was assessed over the course of three test flights conducted in New Mexico, USA, in 2021. The descent enabled high-resolution profiling, with …

Simulation-To-Hardware Validation Of Mpc For Binary Thruster 2d Cubesat Control, Aevar Amundinusarson Oefjoerd

Theses and Dissertations--Mechanical and Aerospace Engineering

Small satellites must execute precise, fuel-limited maneuvers under strict actuation and operational constraints. Model Predictive Control (MPC) is a suitable approach because it optimizes future actions while explicitly enforcing these limits. This work evaluates (1) whether MPC can operate in real time using binary (on/off), asymmetric thrusters, and (2) whether a high-fidelity digital twin can be used to tune and validate the controller prior to hardware testing.

An MPC framework was implemented on a planar satellite prototype that floats on air bearings, operates at 16.7 Hz (60 ms period), and uses eight binary thrusters exhibiting up to 13.2% variation in …

Kentucky Re-Entry Universal Payload System (Krups): Second Atmospheric Re-Entry Flight, Kirsten F. Ford

Theses and Dissertations--Mechanical and Aerospace Engineering

Kentucky Re-entry Universal Payload System (KRUPS) is a small-scale re-entry capsule developed at the University of Kentucky. The KRUPS project began in 2013 with the aspiration of providing an affordable and repeatable method of collecting data on the re-entry environment. Numerically-based methods used to model re-entry require experimental data to validate their predictions. However, re-entry data is not easily obtained. Flight tests of re-entry vehicles require extensive time and resources, including a substantial financial burden. Alternatively, ground testing is not able to accurately and completely replicate the complex re-entry environment. Thus, there is a need for an inexpensive and accessible …

Cultivating Hegemony: Cultural Engineering And The Art Of Power Maintenance In Military Movies, Samuel Lockridge

Theses and Dissertations--Arts Administration

This research explores how the United States military’s assistance to film productions can be better classified and understood as a form of cultural policy. There is a significant gap in the existing cultural policy research concerning interventions into the arts and culture by the military aimed at influencing the thoughts, beliefs, and attitudes of the population. The degree to which the U.S. Department of Defense’s (DoD) long partnership with the film industry should even be considered “cultural policy” remains an open, and largely unexamined question. This dissertation presents an exploratory multiple case study of two films which received DoD production …

Exploring Healthcare Access In Telehealth Through Spanish-Speaking Patients’ Perspectives: A Scoping Review, Abigail J. Verst

Theses and Dissertations--Communication Sciences and Disorders

Background: Telehealth offers a potential solution to addressing access barriers experienced by Spanish-speaking patients. This scoping review aimed to explore whether a comprehensive view of healthcare access is being considered when creating telehealth programs for Spanish-speakers. The Conceptual Framework of Access to Healthcare (Levesque et al., 2013) was used to guide access analysis.

Methods: A literature search was conducted across three databases to identify empirical studies in the United States that reported Spanish-speaking patients’ perspectives of telehealth through quantitative questions. Data was collected from the included articles to characterize the type of healthcare providers and telehealth modalities examined in the …

M1 Macrophage-Engineered Vesicles Have Anti-Cancer Activity In Ovarian Cancer, Connie Du Cao

Theses and Dissertations--Clinical and Translational Science

Ovarian cancer typically presents at an advanced stage, has a poor prognosis, and is a leading cause of cancer-related deaths in women. Extracellular vesicles (EVs) are cell-derived membrane-bound nanoparticles that function in specific cell-to-cell communication and are under development as novel drug delivery vehicles and modulators of the tumor microenvironment. Artificial cell-derived vesicles (ACDVs) derived from M1 macrophages are able to repolarize M2 macrophages to the M1 phenotype and target tumor cells in in vitro studies.

In this study, we generated engineered EVs (EEVs) by membrane disruption of M1 macrophages (MEVs) in the presence and absence of cisplatin to generate …

Exportin 1 Is The Central Hub In Antiviral Defensive Mobilization Of Nuclear Factors And The Target Of Counter-Defence By Tombusviruses, Biao Sun Dr.

Theses and Dissertations--Plant Pathology

Positive-strand RNA viruses, such as coronaviruses and flaviviruses, are obligate parasites whose genomic RNAs function as mRNAs. These viruses infect a wide range of hosts-including plants, animals, and humans-resulting in significant economic losses and posing serious threats to public health. Due to the relatively simple structure of the genome of positive-strand RNA viruses, many host factors and physiological processes are co-opted to support virus infection and replication. In our previous studies, we identified numerous host factors and associated physiological processes involved in the replication of tombusviruses, a cytosolic-replicating model that includes tomato bushy stunt virus (TBSV) and carnation Italian ringspot …

Engineering Novel Biomimetic Models Of Equine Host-Microbe Interactions, Lynn M. Leedhanachoke

Theses and Dissertations--Veterinary Science

One major limitation to the study of equine disease is the lack of in vitro models that accurately reflect the dynamic physiology of the horse. Thus, there is a pressing need to develop in vitro systems that recapitulate diverse equine tissue and organ microenvironments. To overcome this deficiency, we developed multiple biomimetic equine organoid systems that can be employed for a variety of investigations aimed at resolving outstanding questions in infectious disease pathogenesis, therapeutic development and drug metabolism, host defense mechanisms, immune-modulated disease, and equine developmental biology. Our innovative platform incorporates novel equine intestinal enteroid and airway organoid models derived …

Avian Response To Legacy Coal Mine Reforestation In The Cumberland Plateau, Kentucky, Madoline J. Varias

Theses and Dissertations--Forestry and Natural Resources

Surface coal mining and reclamation processes alter the ecological characteristics of landscapes, which affects the presence and distribution of native wildlife. The Forestry Reclamation Approach (FRA) is a coal mine reclamation method that aims to establish native forests on surface mines and has been widely implemented across the Central Appalachian region. Avian response the FRA, in particular, is unknown in Kentucky and limited throughout Appalachia. Thus, the goal of this project was to assess the effects of the FRA on avian community occupancy, species richness, and abundance in the Cumberland Plateau of Kentucky. Point count surveys were conducted across three …

Influence Of Agrochemical Mixtures On Nitrogen Transformations In Floating Treatment Wetlands, Matthew Russell

Theses and Dissertations--Biosystems and Agricultural Engineering

Controlling losses of nitrate-N from agricultural fields to ground and surface water environments is one of the most pressing water resources problems today. Increasing levels of nitrate-N pollution in surface and groundwater is a critical threat to human and environmental health across the globe. To mediate nitrate-N losses, natural and constructed wetlands have been increasingly used as nutrient mitigation technologies and strategies. The use of wetlands as a treatment approach for nitrogen in runoff is a common practice in agroecosystems, however, nitrate-N is not the sole constituent present in agricultural runoff, and other biologically active contaminants have the potential to …

Nanopesticide Fate And Transport In Agroecosystems: A Field Study, John C. Stickney

Theses and Dissertations--Biosystems and Agricultural Engineering

Nanopesticides are an emerging class of pesticides associated with engineered nanoparticles that provide agricultural and environmental benefits. However, nanopesticide fate, transport, and persistence remain poorly understood. As do their potential impacts on the health of agroecosystems and influence on nutrient release. Therefore, this project investigated the fate, transport, and persistence of two widely available nanopesticides, an insecticide, nano-imidacloprid, and a fungicide, nano-copper hydroxide. The fate and transport in runoff water and soils of these nanopesticides, as well as their impacts on nutrients retention, were assessed through a field plot study over 2 growing seasons. Runoff from rainfall events and soil …

Safety Monitoring & Intelligent Power Distribution Systems For Compact Agricultural Equipment, Mason O. Bradley

Theses and Dissertations--Biosystems and Agricultural Engineering

The agricultural industry continues to be one of the most dangerous career fields in the United States of America with compact agricultural equipment being a common source for casualties in the industry. The primary focus of this work is to develop new technology that improves operational safety of compact agricultural equipment through the use of low-cost embedded electronics. This work presents the design of three systems in alignment with this goal.

The first system aims to integrate electrical intelligence and passive safety monitoring into the power distribution system of a small piece of agricultural equipment. The system known as the …

Impacts Of Utilizing Reverse Osmosis Concentrate On Mashing, Fermentation, And Water Use In Bourbon Whiskey Production, Ryan C. Sarhan

Theses and Dissertations--Biosystems and Agricultural Engineering

This thesis addresses the feasibility of reusing reverse osmosis concentrate (ROC) in the bourbon whiskey fermentation processes. Initial work compared laboratory-scale mashing and fermentation methods, demonstrating that simultaneous saccharification and fermentation reliably reflects industrial-scale processes, with lower complexity and process time. Building upon this, laboratory and distillery-scale experiments demonstrated that reusing ROC in the mashing and fermentation steps does not negatively impact ethanol yields. ROC produced by systems with a water softener was found to significantly increase mash rheology, suggesting a need for potential process adjustments. Softened ROC also altered the production of flavor-influencing volatile congeners. Under worst case conditions, …

Quantifying Sedimentation Dynamics Of Regulated River Backwater Confluences With Low-Order Tributaries, Abby Kathryne Berry

Theses and Dissertations--Biosystems and Agricultural Engineering

Sediment dynamics in backwater confluences of regulated rivers have received limited study, despite being recognized as hotspots for sedimentation and nutrient attenuation. Development of management and restoration strategies in these landscapes require improved understanding of fluvial geomorphology and sediment transport dynamics due to the alterations in hydraulic regimes and sediment inputs associated with riverine backwaters. The objective of this study was to couple remote sensing, high frequency sensing, and numerical modeling to quantify drivers of erosion and deposition dynamics within regulated river backwater tributary confluences. To meet the objective of this study, data was collected and analyzed from the Fourpole …

Development Of A Cultivation System For Producing Pure Mycelium Materials From Distillers' Spent Grains, Keya Rani Roy

Theses and Dissertations--Biosystems and Agricultural Engineering

Stillage is a byproduct of distilleries which is rich in organic matter, minerals, and acidic components. It is commonly used as animal feed and has high potential for use as an alternative substrate for microorganisms. Filamentous fungi are saprophytes that can utilize stillage solids to grow as threadlike mycelium. The structure and composition of the filamentous mycelium has shown promise to produce pure mycelium materials (PMM), which might have many potential applications, for instance as a leather-like material or alternative protein food ingredient. Basidiomycota fungi (including true mushrooms) species are presently used in industry to produce PMM due to the …