Engineering Commons^™

Iii-Nitride Triangular Microcantilevers For Multimodal Sensing Applications, Balaadithya Uppalapati

All Dissertations

Micro-electromechanical systems (MEMS)-based sensors have gained significant attention due to their ability to sense, measure, and process various physical, chemical, and biological parameters. The small size of MEMS sensors provides numerous advantages, including low power consumption, high sensitivity, and rapid response time, making them suitable for various applications in healthcare, automotive, aerospace, and consumer electronics.

In the past few years, AlGaN/GaN MEMS devices have been found to offer several advantages over silicon-based MEMS devices. One of the main advantages of AlGaN/GaN MEMS is their high sensitivity to surface stresses and forces due to their high piezoelectric coefficients. This sensitivity allows …

Mesoscale Modeling And Machine Learning Studies Of Grain Boundary Segregation In Metallic Alloys, Malek Alkayyali

All Dissertations

Nearly all structural and functional materials are polycrystalline alloys; they are composed of differently oriented crystalline grains that are joined at internal interfaces termed grain boundaries (GBs). It is well accepted that GB dynamics play a critical role in many phenomena during materials processing or under operating environments. Of particular interest are GB migration and grain growth processes, as they influence many crystal-size dependent properties, such as mechanical strength and electrical conductivity.

In metallic alloys, GBs offer a plethora of preferential atomic sites for alloying elements to occupy. Indeed, recent experimental studies employing in-situ microscopy revealed strong GB solute segregation …

Uibee: An Improved Deep Instance Segmentation And Classification Of Ui Elements In Wireframes, Cahi̇t Berkay Kazangi̇rler, Caner Özcan, Buse Yaren Teki̇n

Turkish Journal of Electrical Engineering and Computer Sciences

User Interface (UI) is a basic concept in which individuals interact with any computer program or technological device to create a graphical design. In the initial stages of app development, UI prototype is a must. An automatic analysis system for the basic execution of UI designs will considerably speed up the development of designs according to old-fashioned methods. In this approach, it is aimed at saving cost and time by automating the process. For the aforesaid objective, we present a new approach rather than the traditional methods. For this reason, a high amount of elements in wireframes are detected and …

Optimization Of Porosity In Cold Spray Produced Copper And Zinc Coatings, Cameron Hughes

Graduate Theses & Non-Theses

Since its invention in 1981, the cold spray (CS) additive manufacturing (AM) process has been studied and optimized to produce well-adhered, dense material coatings. CS can operate at a wide range of temperatures if the feed material remains in a solid state. Copper and zinc were studied to characterize and understand the effects of heating element voltage, travel speed, and standoff distance on deposit porosity, grain size, microhardness, and coating thickness. Samples were sprayed on 3.2 mm x 25 mm x 150 mm 6061 aluminum substrates. Sections were taken from the middle of the samples to represent steady-state conditions. Sample …

High-Pressure Slurry Ablation For Improving Separation Of Copper/Molybdenum And Flotation Of Gold Tailings, Mitchell Harvey

Graduate Theses & Non-Theses

Disa Technologies’ High-Pressure Slurry Ablation (HPSA) is a patented particle attrition technology for the comminution and selective liberation of minerals. Two slurry streams are pumped at high pressure through opposing nozzles and collisions between solid particles suspended in the slurry streams cause breakage of the feed material. HPSA was evaluated for improving the rougher flotation of molybdenite from Cu-Mo bulk concentrate and gold-bearing pyrite from gold tailings.

Copper/molybdenum samples were provided by Montana Resources in Butte, Montana. A two-factor factorial design of experiments was used to identify HPSA operating conditions which gave the highest increase in flotation performance. Variables were …

Predicting The Damage Behavior And Fracture Propagation In A 3d-Printed Synthetic Rock Material With The Distinct Element Method (Pfc3d) And Hybrid Finite-Discrete Element Method (Irazu3d), Frankie Johnston

Graduate Theses & Non-Theses

The ability to monitor and predict the evolution of rock damage and fracture is key for creating reliable and sustainable civil infrastructure. Rock crack propagation is a complex process that is dependent on material properties such as tensile strength, compressive strength, density, elastic modulus, Poisson's ratio, friction coefficient, cohesion, and specimen conditions such as preexisting microcracks, particle size distribution, and mineral distribution. In conjunction with the 56th US Rock Mechanics/Geomechanics Symposium, researchers primarily at Purdue University organized the Damage Mechanics Challenge to determine the current state and future direction of the rock modeling community’s ability to simulate rock crack formation. …

Improving Inference Speed Of Perception Systems In Autonomous Unmanned Ground Vehicles, Bradley Selee

All Theses

Autonomous vehicle (AV) development has become one of the largest research challenges in businesses and research institutions. While much research has been done, autonomous driving still requires extensive amounts of research due to its immense, multi-factorial difficulty. Autonomous vehicles rely on many complex systems to function, make accurate decisions, and, above all, provide maximum safety. One of the most crucial components of autonomous driving is the perception system.

The perception system allows the vehicle to identify its surroundings and make accurate, but safe, decisions through the use of computer vision techniques like object detection, image segmentation, and path planning. Due …

Adversarial Deep Learning And Security With A Hardware Perspective, Joseph Clements

All Dissertations

Adversarial deep learning is the field of study which analyzes deep learning in the presence of adversarial entities. This entails understanding the capabilities, objectives, and attack scenarios available to the adversary to develop defensive mechanisms and avenues of robustness available to the benign parties. Understanding this facet of deep learning helps us improve the safety of the deep learning systems against external threats from adversaries. However, of equal importance, this perspective also helps the industry understand and respond to critical failures in the technology. The expectation of future success has driven significant interest in developing this technology broadly. Adversarial deep …

The Impact Of A Carbon Tax On Emissions, Jessica Creech

Industrial Engineering Undergraduate Honors Theses

A carbon tax is an economic policy that aims to reduce various emissions to serve the protection of the environment. Versions of this policy have been implemented in multiple countries across the world to introduce a cost for contributing to environmental damage. Since climate change is prevalent in today’s world, finding an effective method to reduce emissions is essential. However, many countries hesitate to utilize a carbon tax for two reasons. First, they are unsure if the carbon tax is effective at reducing emissions. Second, there is a concern that the implementation of such a tax will be detrimental to …

A Comparative Biomechanical Investigation Of Porcine Neonatal And Adult Left Ventricular Tissues, Timothy R. Eastep

Bioengineering Theses - Archive

A current trend in cardiac muscle regeneration and repair is to recreate the biophysical and biomechanical environment of the neonatal hearts, which has been shown to promote cardiac regeneration. This translational need requires thorough understanding of the biomechanical properties of the neonatal hearts. In this study, we aim to (i) characterize the dynamic viscoelastic properties of the neonatal porcine left ventricular (LV) muscle and compare with the adult tissue behavior using a rheometer; (ii) perform histological assessment to identify the cellular and extracellular (ECM) microstructures that contribute to the observed biomechanical differences, and (iii) develop a light sheet imaging protocol …

Design And Development Of A Virtual Reality Training Platform For Fiber-Reinforced Composite Manufacturing, Taufiq Rahman

Industrial, Manufacturing, and Systems Theses - Archive

This study presents the design and development of a virtual reality (VR) training platform for manufacturing fiber-reinforced composites, a sophisticated and high-demand material in various industries. Due to the high costs and safety concerns associated with compression molding machines - essential equipment for this manufacturing process, the VR platform offers a promising alternative for training to educational institutions and manufacturing industries. The platform provides an immersive, interactive training and cost-efficient learning environment, allowing users to gain practical experience without the risks and expenses of physical training. The VR training module was developed using the Unity game engine and deployed on …

Damage Tracking In Laboratory Reinforced Concrete Bridge Columns Under Reverse-Cyclic Loading Using Fusion-Based Imaging, Sina Mehdinia, A K M Golam Murtuz, Thomas Schumacher, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

Fusion-based imaging using ground-penetrating radar (GPR) and ultrasonic echo array (UEA) was employed to track damage progression in the columns of two full-scale reinforced concrete (RC) bridge column-footing subassembly laboratory specimens. The specimens had different lap-splice detailing and were subjected to reverse-cyclic lateral loading simulating a subduction zone earthquake. GPR and UEA scans were performed on the east and west faces of the columns at select ductility levels. Reconstructed images were obtained using the extended total focusing method (XTFM) and fused using a wavelet-based technique. Composite images of each column's interior were created by merging the images from both sides. …

Physical Model Of Rainwater Along Roadway Filter Strip, Ryan C. Eberhard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to investigate infiltration rates of rainwater into a roadside filter strip. The findings of this study were intended to be used by the Utah Department of Transportation in their design of stormwater retention. A testing apparatus was designed and constructed to simulate rainfall and infiltration on an inclined slope during the 80^th percentile 24-hour rainstorm event in Utah. The model was used to test six different surface soil configurations at three slope inclinations. Each test was subjected to a simulated storm event of ½ inch of rain over a 2-hour period. The variation …

High Efficiency Angles-Only Space-Based Approaches For Geosynchronous Orbit Catalog Maintenance With Sparse Information, Louis M. Tonc

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The thesis of this dissertation proposes a novel filter algorithm to improve tracking and catalog maintenance of uncooperative satellites and other Resident Space Objects (RSOs) in Geosynchronous Equatorial Orbit (GEO). Tracking can be supported by space-based tracking from observer satellites (OBSs). Practical limitations can lead to long time gaps between measurement updates when tracking RSOs from an OBS, which may induce a loss of fidelity or divergence of the estimation algorithm. The Extended Kalman filter (EKF) is commonly used for tracking RSOs but it diverges as a consequence of nonlinearity in the dynamics and nonlinearity in the optical measurements from …

Evaluating The Impact Of Broadband Access And Internet Use In A Small Underserved Rural Community, Javier Valentín-Sívico, Casey I. Canfield, Sarah A. Low, Christel Gollnick

Engineering Management and Systems Engineering Faculty Research & Creative Works

Having adequate access to the internet at home enhances quality-of-life for households and facilitates economic and social opportunities. Despite increased investment in response to the COVID-19 pandemic, millions of households in the rural United States still lack adequate access to high-speed internet. In this study, we evaluate a wireless broadband network deployed in Turney, a small, underserved rural community in northwest Missouri. In addition to collecting survey data before and after this internet intervention, we collected pre-treatment and post-treatment survey data from comparison communities to serve as a control group. Due to technical constraints, some of Turney's interested participants could …

Tensile Behavior Of Layered Rock Disks Under Diametral Loading: Experimental And Numerical Investigations, Mostafa Asadizadeh, Saeed Khosravi, Soheil Abharian, Mehrdad Imani, Jamshid Shakeri, Ahmadreza Hedayat, Nima Babanouri, Taghi Sherizadeh

Mining Engineering Faculty Research & Creative Works

The Tensile Strength and Cracking Behavior of Layered Rocks in a Tensile Stress Field Are One of the Most Significant Characteristics of Rock Masses, Which May Strongly Affect the Stability of Rock Structures. the Study Presented Here Investigated the Effect of Layer Spacing and Inclination Angle on the Indirect Tensile Strength, Crack Development, Failure Pattern, and Contact Force Chain of Layered Disks under Diametral Loading using Experimental and Numerical Investigations. Numerous Experimental Models Made from Plaster Were Examined under Diametral Loading, and a Two-Dimensional Particle Flow Code (PFC2D) Was Adopted for in Depth Simulation of the Failure Process. Both Numerical …

Transport Phenomena With Reactions In Drug Delivery: Towards A Quantitative Description, Xianjie Qiu, Parthasakha Neogi

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Distributed System Called a Krogh Cylinder is Used Here to Quantify the Transport of a Solute from the Capillary into the Extravascular Tissue. the Capillary Network is Broken Down into Cylindrical Cells, Each Containing a Capillary and an Appropriate Amount of Extravascular Tissue. the Flow in the Cylinder Model Has Two-Dimensional Velocities, Which Are in the Axial and Radial Directions. All Parameters of the System, together with the Geometric Ones, Have Been Included in the Model. for a Given Bioavailability, the Uptakes of Reactive and Nonreactive Solutes Have Been Obtained. Very Large or Massive Molecules Have Been Considered. the …

Dual Crosslinked Poly(Acrylamide-Co-N-Vinylpyrrolidone) Microspheres With Re-Crosslinking Ability For Fossil Energy Recovery, Jingyang Pu, Baojun Bai, Jiaming Geng, Na Zhang, Thomas Schuman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Microspheres have been proposed to be applied in controlling wastewater production for mature oilfields and migrating leakage for gas and nuclear waste storage. However, it remains challenging for stacked microspheres to maintain strong blocking ability in micron-sized small pores or fractures. in this study, a novel microsphere was developed with comprehensive properties including high deformability and long re-crosslinking time upon tunable swelling ratio for the applications. a dual covalent and physical crosslinking strategy was used to develop novel microspheres reinforced by a hydrogen bond (H-bond, between pyrrole ring and amide group) and coordination bond (between chromium acetate (CrAc) and carboxyl …

Exploring The Effects Of Microarchitecture On Astrocyte Behavior And Vascular Remodeling In Spinal Cord Injury, Devin Gerber

Biomedical Engineering Undergraduate Honors Theses

Spinal cord injury (SCI) is a common condition and is characterized by traumatic and progressive damage that results in limited neuron regeneration and thus a restricted recovery. In SCI, the vasculature is also severely damaged, which exacerbates inflammation at the injury site. Specifically, insufficient angiogenesis occurs at the site of injury due to the fibrotic pathological microenvironment1 . SCI also leads to the formation of a fluid-filled cavity and thus gliosis and fibrosis, forming a dense glial and fibrotic scar around the cavity. The microenvironment at the injury site plays a significant role in astrocyte behavior, promoting the transformation of …

Torque And Power Capabilities Of Coreless Axial Flux Machines With Surface Pms And Halbach Array Rotors, Yaser Chulaee, Donovin Lewis, Matin Vatani, John F. Eastham, Dan Ionel

Power and Energy Institute of Kentucky Faculty Publications

This paper investigates employing a Halbach PM rotor array to increase torque and power density within coreless axial flux permanent magnet (AFPM) machines. Analytical and 2/3-dimensional finite element analysis (FEA) methods are developed to study torque and power capabilities within an example double-rotor, single-stator coreless AFPM machine with a PCB stator. Compared to a surface PM topology of the same mass and volume, employing a Halbach array increases torque density by as much as 30% through increased airgap flux density amplitude. Multiple parametric studies are performed to explore methods of increasing torque and power density while employing Halbach arrays combined …

Design Optimization Of A Direct-Drive Wind Generator With Non-Rare-Earth Pm Flux Intensifying Stator And Reluctance Rotor, Ali Mohammadi, Oluwaseun A. Badewa, Yaser Chulaee, Dan Ionel, Somasundaram Essakiappan, Madhav Manjrekar

Power and Energy Institute of Kentucky Faculty Publications

This paper presents a multi-objective design optimization for a novel direct-drive wind turbine generator. The proposed electric machine topology employs an outer rotor of the reluctance type and a special modular stator including three phase-windings and spoke-type permanent magnets (PMs). Each stator module includes a single coil toroidally wound around the ferromagnetic core. Consecutive stator modules are separated by PMs and include coils belonging to a different phase. An optimization method with three objectives: total power loss, weight, and torque ripple, and with one constraint for a minimum acceptable value for the power factor, is described. The design examples are …

An Experimental And Numerical Investigation Of The In-Plane Shear Behavior Of Cantilever Cross-Laminated Timber Diaphragms, Bibek Bhardwaj

All Dissertations

This research focuses on investigating the behavior of Cross Laminated Timber (CLT) diaphragms under in-plane shear loads through an experimental, analytical, and numerical approach. Full-scale destructive tests were conducted on cantilever CLT diaphragms to measure their response to cyclic loading. The results showed that the ultimate capacity of the diaphragms was primarily influenced by the fasteners used and exceeded the LRFD capacity. The primary energy dissipation mechanism was through the slip of diaphragm components and rotation of CLT panels due to fastener deformations. The strain data revealed that the diaphragms exhibited deep-beam-like behavior, with resistance to tensile and compressive forces …

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Rheometers, Mixtures And Procedures, Dimitri Feys, Mohammed Sonebi, Sofiane Amziane, Chafika Djelal, Khadija El-Cheikh, Shirin Fataei, Markus Greim, Irina Ivanova, Helena Keller, Kamal Khayat, Laurent Libessart, Viktor Mechtcherine, Ivan Navarrete, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recent developments in understanding the rheology of mortar and concrete as well as applying this understanding in the practice of construction necessitate an accurate assessment of materials' rheological properties. It is well known that different rheometers for mortar and concrete deliver different results, as this was shown over 15 years ago in two measuring campaigns comparing concrete rheometers. Considering newly developed rheometers, including those to evaluate interface rheology and structural build-up at rest, as well as additional measurement procedures and data interpretation techniques, a new comparison campaign was carried out in 2018 at the Université d'Artois, in Bethune, France. This …

An Integrated Experimental And Modeling Approach To Design Rotating Algae Biofilm Reactors (Rabrs) Via Optimizing Algae Biofilm Productivity, Nutrient Recovery, And Energy Efficiency, Gerald Benjamin Jones

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Microalgae biofilms have been demonstrated to recover nutrients from wastewater and serve as biomass feedstock for bioproducts. However, there is a need to develop a platform to quantitatively describe microalgae biofilm production, which can provide guidance and insights for improving biomass areal productivity and nutrient uptake efficiency. This paper proposes a unified experimental and theoretical framework to investigate algae biofilm growth on a rotating algae biofilm reactor (RABR). The experimental laboratory setups are used to conduct controlled experiments on testing environmental and operational factors for RABRs. We propose a differential-integral equation-based mathematical model for microalgae biofilm cultivation guided by laboratory …

Using Immersive Technology To Improve Mechanical Design: Use Cases, A Review Of Current Technology, And An Experiment In Requirement Elicitation In Virtual Reality, William Hawthorne

All Theses

There has been a growing trend in the use of immersive technologies within engineering design. This research is focused on understanding how Virtual Reality (VR) technologies support design reviews. Modern tools including virtual reality hardware and software were tested for current capabilities and challenges. In a review of literature, two key gaps are identified: the rapid advancements of VR and AR technology and limited formal studies to determine the costs and benefits of immersive technology within engineering design reviews. This research has resulted in three key outcomes. First, use cases of immersive reality technologies are identified, through the lens of …

Catalytic Water Photolysis For Generating Renewable Hydrogen Fuel, Dr. Niveditha Nanda

Open Access Theses & Dissertations

Modern advances have enabled rapid industrialization and urbanization. However, the consequences of global modernization have included significant pollution to the air and water resources. Consequently, many changes to energy use must come to address and mitigate damages to our future. Solar energy derived hydrogen gas is a clean, renewable fuel that does not produce carbon dioxide or other pollutants. My research investigates the use of heterogeneous photocatalysis, by focusing on solar photochemical energy conversion, which is the making of hydrogen from water using sunlight. The production of clean, renewable hydrogen fuel will enable the utilization of low-cost, pollution-free energy resources …

Fiscal Year 2021 Fhwa-536 Report For The Kentucky Transportation Cabinet, Doug Kreis, Candice Wallace, Bryan Gibson, Sarah Mccormack

Kentucky Transportation Center Research Report

No abstract provided.

Point Heat Source Correlation To Microstructural Evolution In Advanced Manufacturing, Mark Anderson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Although there are different ways that advanced manufacturing can be performed, the use of single-point heat sources has become the standard to control a final product’s properties. It is imperative to understand how the heat source used in the different advanced manufacturing processes affect the microstructure of interest. The intimate relationship between the heat source and microstructure allows for controlling and tailoring a part’s properties. Utilizing different microstructural analysis, the cross-correlation of various point heat sources to developed microstructure was conducted in this dissertation.

Laser powder bed fusion allows for unique print-to-part protocols, but the dynamics of the process makes …

Assessment Of Bridge Pier Response To Fire, Vehicle Impact, And Air Blast, Chen Fang, Qusai Alomari, Daniel G. Linzell

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Highway bridges exposed to intentional or unintentional fire followed by combined vehicle impact and air blast are at risk of significant damage and, possibly, collapse. Limited studies examining the complex effects of these extreme demands on bridge support elements and parametrizing their response and damage are found in the open literature. Research that is presented is part of an ongoing numerical investigation examining round, multi-column, reinforced concrete (RC), bridge pier behavior subject to multi-hazard scenarios involving fire, vehicle impact, and air blast. Detailed nonlinear finite element analysis models of single columns and multi-column piers supported by a pile foundation system …

Trace Dna Detection Using Diamond Dye: A Recovery Technique To Yield More Dna, Leah Davis

Master's Theses

This study aspires to find a new screening approach to trace DNA recovery techniques to yield a higher quantity of trace DNA from larger items of evidence. It takes the path of visualizing trace DNA on items of evidence with potential DNA so analysts can swab a more localized area rather than attempting to recover trace DNA through the general swabbing technique currently used for trace DNA recovery. The first and second parts consisted of observing trace DNA interaction with Diamond Dye on porous and non-porous surfaces.

The third part involved applying the Diamond Dye solution by spraying it onto …