Engineering Commons^™

Relating Temperature, Sleep, And Pathology In Mouse Models Of Alzheimer's Disease, Jun Wang

Theses and Dissertations--Biomedical Engineering

It is well established that sleep plays an important role in Alzheimer’s disease (AD) pathology. There is growing evidence that sleep issues may accelerate AD pathology by interrupting the physiological clearance of amyloid‐β (Aβ) from the brain, which mainly occurs in normal sleep. As the over-accumulation of amyloid‐β (Aβ) is believed to lead the cascade effect that eventually causes neurodegeneration in AD patients, development of therapeutic strategies for improving sleep quality may help slow disease progression. It is well documented that the composition and dynamics of sleep are sensitive to changes in ambient temperature. We therefore developed a sleep enhancement …

Development Of Iron Oxide Nanozyme For Cancer Therapy, Zhongchao Yi

Theses and Dissertations--Biomedical Engineering

Cancer therapies that leverage reactive oxygen species (ROS) have shown potential for cancer inhibition due to their ability to induce oxidative stress in tumor cells. Iron oxide nanoparticles (IONPs) have garnered significant attention as a promising platform for ROS-dependent disease treatment, owing to their remarkable biocompatibility and Fenton catalytic activity. However, the low catalytic activity of IONPs has been a major hurdle in their clinical translation. To overcome this challenge, IONPs of different compositions are examined for their Fenton reaction under pharmacologically relevant conditions in this work. The results show that wüstite (Fe_1-xO) nanoparticles exhibit higher catalytic activity …

Impact Of Augmented Documentation Workflows On Transportation Agency Asphalt Paving Operations: A Qualitative And Quantitative Study, Josh Withrow

Theses and Dissertations--Civil Engineering

e-Ticketing was an intriguing technology to many state transportation agencies (STAs) pre-COVID-19 pandemic but gained significant attention upon arrival of the pandemic due to the contactless nature of the technology. Research completed prior to the pandemic into e-ticketing for asphalt paving primarily identified qualitative benefits and concerns. However, minimal academic literature exists in the post-pandemic era discussing the additional e-ticketing benefits not previously captured which resulted in increased implementation by STAs. This research seeks to address this gap by gathering information from state members of the American Association of State Highway and Transportation Officials Committee on Construction (AASHTO COC), employees …

Estimation Of Mechanical Behavior Of Unsaturated Soils From A Soil-Water Characteristic Curve, Lucas Acheampong

Theses and Dissertations--Civil Engineering

The small-strain shear modulus and shear strength are two crucial mechanical behaviors used in the design of geotechnical structures and in the analyses of earth materials subjected to static and dynamic loadings. Traditional testing methods for these parameters are expensive and time-consuming. This research aimed to address these challenges by developing a model based on the inverse relationship between mechanical behavior of unsaturated soils and the soil-water characteristic curve (SWCC). The proposed model integrates a scaling function to align the SWCC with the mechanical property curve. Empirical relationships were established for the scaling function, specifically aligning with the air-entry value …

Geophysical Method Used For The Determination And Prediction Of Soil Strength And Stiffness Parameters, Dabo Adama

Theses and Dissertations--Civil Engineering

This paper presents the results of an effort to use geophysical measurements such as seismic wave velocities and electrical resistivities to calculate airfield design parameters. The study converts all geophysical measurements to equivalent California Bearing Ratio (CBR) values, comparing CBR values estimated from DCP penetration resistance with CBR values estimated from shear wave velocity and electrical resistivity values. Relationships linking the geophysical measurements to CBR estimates were established using laboratory data and applied to field in-situ measurements. The elastic modulus (E) is the stiffness parameter involved in predicting soil strength and stiffness. This research aims to relate electrical conductivity and …

Analysis And Improvement Of The Kentucky Transportation Cabinet’S Serious Injury And Fatality Program, Arun Subedi

Theses and Dissertations--Civil Engineering

Serious Injuries and Fatalities (SIFs) within construction and maintenance industries indicate severe vulnerabilities within workplace safety, and their prevention requires the highest priority. SIFs usually occur due to systemic failures, and proactive steps must be taken to identify and neutralize high-risk scenarios. Kentucky Transportation Cabinet (KYTC) has recently implemented a safety management system called BOOTS, for improving incident reporting and analysis along with SIFs. This study identifies gaps in KYTC's SIF reporting framework and provides analysis on recurring incident trends utilizing the incidents already reported in the system. While current practice in KYTC relies on event-based decision tree when classifying …

Digital Innovation Roadmap For Construction Industry: Bridging The Gap For Future, Nisa Zahin

Theses and Dissertations--Civil Engineering

Digitalization has considerable value in the digital transformation of the construction business. It means the use of digital technologies to create revenue, improve business, increase profit and sustainability, and create an environment for digital business whereby digital information is at the core. As such, digital transformation requires skills that involve extracting and exchanging data and analyzing and converting that data into actionable information. In addition to technological solutions, a paramount need is to ensure that the people using these solutions and the processes used to integrate, coordinate between teams, and continuously improve the use of technology are in place. Therefore, …

The Characterization And Nanomechanical Properties Of Microstructurally Complex Systems, Kerry Ann Baker

Theses and Dissertations--Chemical and Materials Engineering

Since the dawn of civilization, the use of metals has played an integral role in the evolution of human society. Over the years, and with the introduction of new engineering and science, we have learned how to combine metals to create new metallic systems. We have expanded our understanding of dealloying and chemical reactions, and, in doing so, we created nanoporous metals. Our use of metals has evolved from basic alloys such as bronze and steel to more complex alloys such as multi-principal element alloys. Nanoporous gold is an advanced metallic system that can be created through the dealloying process. …

Advancing Combinatorial Screening Of Refractory High Entropy Alloys Through Intrinsic Ductility Assessment Via Thin Film Fragmentation Testing, Taohid Bin Nur Tuhser

Theses and Dissertations--Chemical and Materials Engineering

High Entropy Alloys (HEAs), also known as Multiprincipal Element Alloys (MPEAs), represent a paradigm shift in alloy design. Unlike traditional practices that limit compositions to the edges of phase diagrams, HEAs exploit equiatomic mixing of five or more elements at the center of phase diagrams to maximize configurational entropy. This unconventional approach exponentially expands the spectrum of potential alloy compositions, rendering conventional experimental methods inadequate for exploring this extensive compositional space.

In response to these challenges, the scientific community has shown a growing interest in high-throughput techniques, encompassing both computational and experimental domains. Particularly, Refractory High Entropy Alloys (RHEAs) have …

Microstructural Investigation Of The Influence Of Geometry On The Mechanical Reliability Of Additively Manufactured Metals, Tracy Connor Varney

Theses and Dissertations--Chemical and Materials Engineering

The adoption of additive manufacturing across a wide range of fields is ever-increasing, allowing for solutions that were previously impossible to achieve. This dissertation demonstrates the wide range of macro- and micro- characterization techniques used to investigate several precipitation strengthened AM alloy systems. While AM allows for nearly unlimited design freedom, this brings along its own issues as the interplay between scan strategy and part geometry is less well known. In this work, a novel thin-wall dogbone geometry was utilized to study one type of complex geometry observed in a large portion of AM focused designs. The mechanical behavior of …

Language Models For Rare Disease Information Extraction: Empirical Insights And Model Comparisons, Shashank Gupta

Theses and Dissertations--Computer Science

End-to-end relation extraction (E2ERE) is a crucial task in natural language processing (NLP) that involves identifying and classifying semantic relationships between entities in text. This thesis compares three paradigms for end-to-end relation extraction (E2ERE) in biomedicine, focusing on rare diseases with discontinuous and nested entities. We evaluate Named Entity Recognition (NER) to Relation Extraction (RE) pipelines, sequence-to-sequence models, and generative pre-trained transformer (GPT) models using the RareDis information extraction dataset. Our findings indicate that pipeline models are the most effective, followed closely by sequence-to-sequence models. GPT models, despite having eight times as many parameters, perform worse than sequence-to-sequence models and …

Optoelectrical Properties And Photostability Of Cspbbr3 Quantum Dots: Effects Of Dopants And Ligands, Md Shad Bin Salam

Theses and Dissertations--Chemical and Materials Engineering

Metal halide perovskite QDs have a great potential for displays and lighting because of their exceptional optoelectronic characteristics associated with quantum confinement effect. However, the stability in the environment during the applications of halide perovskite QDs remains a significant challenge, impeding their practicality and lowering their commercial scalability. High-temperature methods are well-established for producing doped perovskite QDs, the influence of room-temperature synthesis on thermal, size-dependent optical properties, and long-term stability remains inadequately understood. Also, there is a demand for strategies to increase the absorption of light, reduce trap states, and modify the energy levels of perovskite QDs.

In this study, …

Thermal Alteration Of The Mineralogy Of Calcium Sulfoaluminate Cements: Implications For The Performance Of Rapid Repair Materials, Jillian Cavellier

Theses and Dissertations--Earth and Environmental Sciences

Calcium sulfoaluminate (CSA) was developed in part to lessen the environmental impact of cementitious materials compared to traditional Portland cements. CSA was first put into production in the 1970s and has been undergoing various performance testing to investigate its durability. Yet to be evaluated is CSA’s response to a rapid, high temperature event. In this study, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectrometry and scanning electron microscope imaging were used to analyze alterations in the mineralogy due to such an event. As found in previous studies, after ~125°C, ettringite has been completely dehydrated. Ettringite decomposes into bassanite and calcium …

Visualizing And Automating Past, Real-Time, And Forecast Dynamic Hazard Maps For Shallow Colluvial Landslides In Eastern Kentucky, Nathaniel O'Leary

Theses and Dissertations--Earth and Environmental Sciences

Landslide hazards are a persistent threat to communities and infrastructure in Eastern Kentucky, where steep slopes, shallow colluvial soils, and variable hydrological conditions make slope failures frequent. This thesis presents an integrated approach to landslide hazard mapping (LHM) through the development of dynamic, spatiotemporal LHMs for shallow colluvial landslides. Two studies within this work investigate and refine the use of the Lu and Godt (2008) factor of safety (FS) equation to improve landslide predictions. The first study establishes a novel LHM workflow using Hydrus-1D to simulate soil moisture infiltration and fluctuations from precipitation and evapotranspiration (ET) data. This study also …

Advancements In Elliptic Mesh Redistribution And Automated Overset Grid Generation For Computational Fluid Dynamics, Chase Ashby

Theses and Dissertations--Mathematics

Automated and robust structured curvilinear overset grid generation remains a significant challenge for the application of computational fluid dynamics. This thesis intro- duces a specialized anisotropic Mach cone aligned adaptation algorithm for low-boom simulations and an automated procedure for generating structured curvilinear overset grids for immersed boundary simulations. Results demonstrate that anisotropic mesh adaptation can reduce computational resource usage by over 50% while maintaining sonic boom prediction accuracy across the entire sonic boom domain compared to user-constructed Mach cone aligned grids. The proposed immersed overset grid gen- eration procedure eliminates the need for complex surface generation algorithms, producing grids suitable …

The Methodology For Integrating Robotic Systems In Undeground Mining Machines, Peter Kolapo

Theses and Dissertations--Mining Engineering

Roof bolting is a critical operation in ensuring the safety and stability of underground mines by securing the roof strata with bolts. The process involves moving and manipulating heavy tools while being vigilant about the safety of the area. During the installation of roof bolts, operators are exposed to hazardous conditions due to challenging working conditions in underground mines, extensive working hours, and demanding shift schedules leading to personnel fatigue and influencing operators to take shortcuts that may increase the risk of injuries and fatal accidents. The successful completion of roof bolting tasks depends heavily on operator judgment and experience …

Autonomous Shuttle Car Docking To A Continuous Miner Using Rgb-Depth Imagery, Sky Rose

Theses and Dissertations--Mining Engineering

A great deal of research is currently being conducted in automating mining equipment to improve worker health and safety and increase mine productivity. Significant progress has been made in some applications, e.g., autonomous haul trucks for surface mining. However, little progress has been made in autonomous face haulage in underground room-and pillar coal mines. Accordingly, this thesis addresses automating the operation of a shuttle car, focusing on positioning the shuttle car under the continuous miner coal-discharge conveyor during cutting and loading operations. The approach uses a stereo depth camera as the sensor, and machine-learning algorithms are used to identify various …

Discrete Element Modeling To Predict Muckpile Profiles From Cast Blasting, Russell Lamont

Theses and Dissertations--Mining Engineering

Movement of overburden or ore from one location to another may be considered the primary physical process of mining. The means by which it is transported is then of primary concern both to economic production and cost control. The geologic characteristics of some mineral deposits, especially coal and phosphates, lend themselves to overburden transport by means of cast blasting, which when efficiently designed has proven itself to be a cheaper method than traditional truck/shovel, dragline, or even dozer push transport. Simultaneously, this movement of a significant portion of overburden using explosives may enable an operation to increase mineral production, as …

Prediction Of Final Subsidence Under Dipping Seam Conditions, Ernesto Maldonado Esguerra

Theses and Dissertations--Mining Engineering

The prediction of ground movements due to underground coal mining and their impacts on the surface are essential considerations that numerous researchers worldwide have studied. Most of these studies have focused on developing different analytical and empirical models for predicting and calculating ground deformation indices for flat or gently dipping seams under variable topography. However, a few studies are available on predicting ground movements under dipping seam conditions. Although most inclined coal seams are in China, India, and a few other countries, dipping seam conditions have been encountered in some cases in the US, where the inclination (dip) may be …

Copper Ammoniacal Recycling Process Development For Leaching Electrolyte, Solvent Extraction, And Electrowinning, Zulqarnain Ahmad Ali

Theses and Dissertations--Mining Engineering

Electronic waste (e-waste) encompasses waste originating from electronic and electrical equipment. In 2022, 59.4 million metric tons of e-waste were generated, projected to increase to 74.7 million metric tons by 2030. Among the most valuable components within E-Waste are the printed circuit boards (PCBs), primarily composed of metals including copper (Cu), gold (Au), silver (Ag), cobalt (Co), nickel (Ni), bismuth (Bi), and various other base and precious metals. Notably, copper is the predominant element in PCBs, with concentrations exceeding those in their respective ores. The high demand for copper driven by the ongoing push towards greener technologies and its abundant …

Characterization And Concentration Of Critical Minerals And Rare Earth Elements From Primary And Secondary Silicate Deposits, Muhammed Melih Elseyh

Theses and Dissertations--Mining Engineering

Critical materials (CMs) are crucial for sustainable energy. This investigation explored the extraction of rare earth elements (REEs) from the Halleck Creek deposit in Wyoming, and CMs from a construction sand deposit in Missouri. The Halleck Creek deposit is REE enriched (0.32%) as the mineral allanite within silicious host rock. Density fractionation tests revealed that 70% of the gangue can be rejected while recovering 90% of the REEs with an upgrading ratio of 4.5:1. By exploiting allanite’s paramagnetic properties, magnetic separations achieved a TREE upgrade ratio of 3:1 with 87% TREE recovery. Based on the density fractionation results, a rougher-scavenger-cleaner …

The Determination Of Darcy Permeabilities And Slip Parameters In Porous Thermal Protection Media Via Pressure-Driven Steady Flows At Varying Levels Of Thermal Decomposition, John Ryan O'Nan

Theses and Dissertations--Mechanical and Aerospace Engineering

A flow apparatus for determining the Darcy permeability and Klinkenberg molecular slip adjustment parameter in arbitrary porous media was created. Two leak-proof methods were developed to secure samples of porous media in the flow apparatus independent of surface irregularities, structural integrity, or material porosity. The first of these methods uses thermoset resin casting to permit material samples of a highly irregular profile to be studied. The second method utilizes heat-shrink polyolefin tubing to create a wall seal while preserving the exposed faces of a given cylindrical sample, enabling the study of inhomogeneous surface features. These methods were used to characterize …

Propagation Of Vibro-Acoustic Energy In Ducts: Measurement, Simulation, And Attenuation Studies, Caoyang Li

Theses and Dissertations--Mechanical and Aerospace Engineering

Vibro-acoustic energy propagates through heating, ventilating, and air conditioning (HVAC) systems through both airborne and structureborne paths. In this research, measurement and simulation studies are performed to better understand this propagation of energy and how to better attenuate the sound before it impacts building occupants.

First, a scaled-down experiment was developed to assist in the validation of numerical simulation models. A small source room was attached to a wooden duct with variable cross-sectional area. The sound power for both untreated and treated ductwork was measured using sound intensity scanning, and the insertion loss is the difference between untreated and treated …

Artificial Intelligence Enabled Machinery Fault Detection And Diagnosis Using Vibro-Acoustic Signals, Srinivasa Rao Ippili

Theses and Dissertations--Mechanical and Aerospace Engineering

In various industries, the early detection of faults in rotating machinery is crucial to prevent system failures and ensure customer satisfaction. Typically, vibration measurement and diagnosis are employed for fault detection, but this process faces challenges in automation due to the complexity of installing and maintaining accelerometers, particularly in end-of-line quality control or pre-installed machinery health assessments. Acoustic signals, as a form of mechanical wave, offer an alternative for monitoring machinery while in operation. Unlike accelerometers, acoustic transducers are non-contact and easy to set up, enabling real-time data collection without interrupting equipment operation. However, utilizing acoustic signals in manufacturing poses …

Characterization Of The Spallation Phenomenon In Ablative Thermal Protection System Materials Resulting From Arc-Jet Experiments, Kristen Price

Theses and Dissertations--Mechanical and Aerospace Engineering

Thermal protection systems are critical for protecting spacecraft from the large amounts of heating incurred during atmospheric entry. Ablative thermal protection systems in particular often consist of a carbon fiber matrix impregnated with a polymer resin and use thermal and chemical reactions to decompose the material. Weakening of these carbon fibers by oxidation, along with the impact of shear forces, results in the mechanical failure of these materials in a process known as spallation. Being able to quantify and characterize this process is important for modeling and designing heat shield materials that account for the additional spalled mass loss.

Two …

Measurement And Simulation Of Aeroacoustic Sources Generated By Elementary Muffler Components, Seth Donkin

Theses and Dissertations--Mechanical and Aerospace Engineering

Mufflers and silencers are commonly used to control noise from sources such as internal combustion engines and heating, ventilating, and air conditioning (HVAC) systems. In these applications, flow interacts with muffler components generating aeroacoustic noise sources. In order to measure these sources in a lab setting, specialized flow rigs are designed to isolate aeroacoustic noise sources. Flow sometimes compromises muffler performance. However, muffler performance is sometimes improved because flow can increase the attenuation of some muffler elements such as perforates. To better understand the complicated impact of flow, the University of Kentucky developed a muffler test rig to measure insertion …

Droplet Analysis Of Spray Inside A Compact Column Gas Scrubber Through Shadowgraphy, Brandon Heller

Theses and Dissertations--Mechanical and Aerospace Engineering

The shadowgraphy imaging technique was adapted to analyze the droplet field from a spray nozzle inside the gas absorption section of a compact column gas scrubber. This technique in conjunction with a developed image processing technique was able to gain statistical size information at different distances from two types of spray nozzles. The gas scrubber then ran a parametric campaign of eight operating conditions and statistical size information was captured for each case with the goal of understanding how operating conditions affect the droplet field properties. Lastly, several simulations were completed to understand how the addition of recirculation zones would …

Microstructure-Based Modeling And Simulation Via A Nonlocal Multiphysics Discrete Approach, Donglai Liu

Theses and Dissertations--Mechanical and Aerospace Engineering

Many structures in engineering are subject to multiphysics loadings or environment. Computational modeling plays a significant role to predict or evaluate the performance of these structures, especially in the scenarios where the experimental investigation is cumbersome or prohibitively expensive. Microstructure-based modeling incorporates the information of microstructures of materials in numerical models, which can provide insights about the relationship between microstructures and mate- rial properties. This research developed a microstructure-based modeling framework for coupling diffusion-deformation simulation of solids. The model is based on a recent developed meshfree method referred to as lattice particle method in the literature. In the developed model, …

Mechanochemical Synthesis Of Halide Perovskite Microcrystals, Xuan Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Halide perovskites have emerged as a promising class of materials for various optoelectronic applications, including light-emitting diodes (LEDs), solar cells, photodetectors, and lasers, owing to their exceptional photophysical properties and ease of synthesis. Lead-based halide perovskites, despite their success, raise concerns regarding environmental toxicity, necessitating the exploration of lead-free alternatives. This thesis explores the synthesis and characterization of lead-free halide perovskites, focusing on tin-based variants, using a mechanochemical approach, which eliminates the use of toxic solvents and offers a sustainable synthesis route.

By employing a solventless mechanochemical method, lead-free tin-based halide perovskite microcrystals were successfully synthesized. This approach not only …

Provably Safe Control For Input-Constrained Robotic Systems, Pedram Rabiee

Theses and Dissertations--Mechanical and Aerospace Engineering

This dissertation addresses challenges in control design for safety-critical robotic systems with input constraints. It focuses on developing novel control barrier function (CBF) approaches to ensure safety while optimizing performance. The work is motivated by the limitations of traditional methods in handling nonlinear systems with multiple constraints and actuator limits.

Three main contributions are presented. First, a soft-minimum barrier function is introduced, utilizing finite-time horizon predictions to create control forward invariant subsets of the safe set while respecting actuator constraints. This method is extended to multiple backup controls, which can enlarge the safe operating region.

Second, a technique for composing …