Engineering Commons^™

High-Fidelity Coupling For Studies Of Ablative Materials At Hypersonic Conditions, Aleksander Zibitsker

Theses and Dissertations--Mechanical and Aerospace Engineering

The development of accurate models and robust numerical tools for simulating ablative thermal protection materials (TPMs) in hypersonic flows is crucial for advancing atmospheric entry and hypersonic technologies. Traditional methods for simulating ablative materials often rely on heavy assumptions, such as equal heat and mass transfer coefficients and chemical equilibrium in the boundary layer, leading to conservative thermal protection system (TPS) designs and insufficient accuracy for certain in-flight ablation phenomena.

This work presents a high-fidelity and versatile coupled framework between hypersonic flow and material response solvers. The flow domain is modeled with an innovative overset CHAMPS NBS-Cart solver, which features …

Multiscale Fiber Remodeling In The Heart Using A Finite Element Framework, Mohammad Mehri

Theses and Dissertations--Mechanical and Aerospace Engineering

The organization of myofibers and extra cellular matrix within the myocardium plays a significant role in defining cardiac function. When pathological events occur, such as myocardial infarction (MI) or hypertrophic cardiomyopathy (HCM), this organization can become disrupted, leading to alteration in pumping performance. The current study proposes a multiscale finite element (FE) framework to determine realistic fiber distributions in the left ventricle (LV). This is achieved by implementing a stress-based fiber reorientation law, which seeks to align the fibers with local traction vectors, such that contractile force and load bearing capabilities are maximized. By utilizing the total stress (passive and …

Characterization Of Heterogeneous Material Architectures Through X-Ray Computed Micro-Tomography, Cameron Brewer

Theses and Dissertations--Mechanical and Aerospace Engineering

Low-density carbon-phenolic composites, such as phenolic impregnated carbon ablator (PICA), possess meso-, micro-, and nano-pores making the structure of the resin difficult to characterize. X-ray Computed Tomography (XRCT) is a widely ac- cepted method for characterizing the carbon fiber preform, yet this technique is often insufficient for visualizing the resin because of its minimal attenuation of the incident x-ray beam. Phase Contrast Retrieval (PCR) reconstruction considers not only the linear attenuation coefficient, but also the refractive indices of the constituent materials. This research leverages phase contrast tomography to characterize the meso- and micro-structure of the porous resin phase with a …

Development Of Lignin Derived Hydrophobic Deep Eutectic Solvents As Sustainable Solvents And Their Applications, Yuxuan Zhang

Theses and Dissertations--Biosystems and Agricultural Engineering

The development of green solvents is a pivotal endeavor in achieving the goals of green chemistry. Ionic liquids (ILs) and deep eutectic solvents (DESs) have emerged as promising green alternatives to conventional organic solvents due to their low toxicity, potential biodegradability, low volatility, and high tunability. Compared to ILs, DESs have attracted more attention recently as they are easier and less expensive to produce. Hydrophobic DESs (HDESs), a new generation of DESs introduced in 2015, have gained considerable interest for their ability to overcome the instability issues of traditional DESs when exposed to water. This advancement extensively broadens the application …

Implications Of Nanopesticides On Downstream Wetland Ecosystems, Kiley Power

Theses and Dissertations--Biosystems and Agricultural Engineering

Nanopesticides are thought to be a promising course of action for reducing agricultural impacts on the environment, however, little is known regarding the fate and transport of nanopesticides, specifically their influence on downstream wetland ecosystems. The objective of this study was to assess the implications of a nano-Cu fungicide (Kocide 3000) and a neonicotinoid insecticide (imidacloprid) on downstream wetland habitats, particularly their effects on wetland nutrient cycling, using fifteen mesocosm wetlands. The complex interactions between nitrogen, Kocide 3000, and imidacloprid were found to increase nitrate removal rates, decrease phosphate removal rates, and inhibit nitrogen uptake in below-ground biomass. Each treatment, …

The Characterization, Assessment, And Shear Strength Of Turfgrass Soil In North American Thoroughbred Racing, Peter Schmitt

Theses and Dissertations--Biosystems and Agricultural Engineering

Minimizing catastrophic injuries to racehorses, which also protects the riders, is critical for the future of the Thoroughbred racing industry. While the causes of catastrophic injuries are multifactorial, the condition of the racing surface is one of only a few factors that affects all horses in competition. Horse racing surfaces must retain enough shear strength to support the hoof of a Thoroughbred at a gallop. Turfgrass racing surfaces also require healthy turf to reinforce the footing while also achieving a high infiltration rate to allow races to run on the turf soon after or even during rain. This research is …

Wetland Treatment Systems For Municipal Wastewater At A Bourbon Distillery And Potential Value Of Incorporating Stillage For Water Treatment Enhancement, Katherine J. Ristola

Theses and Dissertations--Biosystems and Agricultural Engineering

The use of constructed treatment wetlands, as a secondary treatment method for wastewater effluent from package treatment plants and distillery stillage has potential to be an innovative, sustainable method for improving water quality in the Central Kentucky region. However, the use of constructed wetlands to treat stillage and wastewater treatment plant effluent has been limited. Therefore, the objectives of this study were to: 1) quantify constructed wetland removal as a secondary treatment method for distillery’s wastewater; 2) explore the potential to utilize constructed treatment wetlands to remove nutrients from bourbon stillage; and 3) optimize treatment design to meet wastewater effluent …

Utilizing Isotope Tracing To Assess Land Use Implications To Tap And Stream Water Chemistry, Katrina Alexis Mcfadden

Theses and Dissertations--Biosystems and Agricultural Engineering

Water quality is an issue that continues to be worsened by extreme flooding, specifically in Eastern Kentucky. The most recent 2022 flooding event in Eastern Kentucky resulted in loss of human life, over $23.3 billion in damaged infrastructure, and impaired human health. Infrastructure failures, such as leaky pipes, are a growing challenge in these regions as rebuilding has occurred. Therefore, the goal of this project was to evaluate water quality in two of the counties most impacted by the 2022 flood in Kentucky, Breathitt and Perry Counties, using sulfur isotopes as a novel tracer to identify potentially failures in distribution …

The Efficacy Of Wetland Treatment Systems Used To Treat Runoff Mixtures From Different Landscapes Across Kentucky, Emily Nottingham

Theses and Dissertations--Biosystems and Agricultural Engineering

The overarching goal was to improve our understanding of the cumulative effect of increased use and occurrence of commonly detected contaminants of potential concern (CPCs) on nitrogen (N) transformation processes in wetlands. The central hypothesis was that those various mixtures of nutrients and CPCs entering treatment wetlands impact N removal pathways. The first study assessed the current state of the literature on the implications to N removal in wetlands in the presence of pesticides and antibiotics. 181 primary studies were identified. Removal efficiencies for nitrate varied widely across the studies, with CPCs impacting microbial communities. A knowledge gap remains in …

Valorization Of Bourbon Distilling Waste Using Thermal Conversion Processes For Nutrient-Rich Food Products, Tosin Olayemi Olanrewaju

Theses and Dissertations--Biosystems and Agricultural Engineering

The Commonwealth of Kentucky accounts for over 95% of global bourbon production. A primary byproduct of bourbon production is stillage, which has a very high moisture content (91–94%) and high biochemical oxygen demand, making it challenging to manage. The recent expansion of the bourbon industry has heightened environmental concerns regarding the best methods to handle this byproduct. Dewatering and drying of stillage produce distillers' spent grains (DSG-B), which are rich in dietary fiber and protein and could serve as an excellent source of functional fiber in human nutrition.

This study examined the approach for dewatering, drying, inclusion of DSG-B as …

Development Of A Low-Cost Resistivity Meter For Local Groundwater Survey, Jose Claro N. Monje, Ma. Leonora Guico, Carlos M. Oppus, Mark Glenn F. Retirado, Alfonso Rafael Cuezon, Justin Bryce M. Torres

Electronics, Computer, and Communications Engineering Faculty Publications

The researchers developed a low-cost resistivity meter with a built-in data file storage system using locally available parts. This effort was done in partnership with the National Water Resources Board and the Department of Science and Technology under the Water for Tourism project for water quality monitoring in tourist areas in the Philippines such as Boracay and Caticlan. The resistivity meter system consists of a power supply module, a sensor module, and an equipment module, built using locally available materials and equipment, emulating the commercially available PASI model 16 GL-N. Due to pandemic restrictions, the developed prototype could only be …

Impacts Of Open-Source Hardware Movements On Electronics Engineering Educational Outcomes, Angelica Tolentino Masa, Ralph Anthony Ramos Rafael, King Harold A. Recto

Electronics, Computer, and Communications Engineering Faculty Publications

The integration of the Open-source Hardware (OSHW) movement into electronics engineering education has not only democratized access to intricate designs but has also transformed the pedagogical landscape. OSHW's principles, inspired by the open-source software paradigm, have given rise to a collaborative learning environment where students bridge the gap between theoretical knowledge and practical application. This research, conducted through a rigorous methodology encompassing literature review, thematic analysis, and purposive sampling from reputable academic sources like IEEE Xplore, highlights the significant potential of OSHW. It not only enhances curriculum development and practical skill acquisition but also fosters a sense of global community …

Heating Capacity And Biocompatibility Of Hybrid Nanoparticles For Magnetic Hyperthermia Treatment, Aline Alexandrina Gomes, Thalita Marcolan Valverde, Vagner De Oliveira Machado, Emanueli Do Nascimento Da Silva, Daniele Alves Fagundes, Fernanda De Paula Oliveira, Erico Freitas, José Domingos Ardisson, José Maria Da Fonte Ferreira, Junnia Alvarenga De Carvalho Oliveira, Eliza Rocha Gomes, Caio Fabrini Rodrigues, Alfredo Miranda De Goes, Rosana Zacarias Domingues, Ângela Leão Andrade

Michigan Tech Publications

Cancer is one of the deadliest diseases worldwide and has been responsible for millions of deaths. However, developing a satisfactory smart multifunctional material combining different strategies to kill cancer cells poses a challenge. This work aims at filling this gap by developing a composite material for cancer treatment through hyperthermia and drug release. With this purpose, magnetic nanoparticles were coated with a polymer matrix consisting of poly (L-co-D,L lactic acid-co-trimethylene carbonate) and a poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) triblock copolymer. High-resolution transmission electron microscopy and selected area electron diffraction confirmed magnetite to be the only iron oxide in the sample. Cytotoxicity …

Climate-Influenced Phenology Of Larval Fish Transport In A Large Lake, Spencer T. Gardner, Mark D. Rowe, Pengfei Xue, Xing Zhou, Peter J. Alsip, David B. Bunnell, Paris D. Collingsworth, Edward S. Rutherford, Tomas O. Höök

Michigan Tech Publications

Elucidating physical transport phenologies in large lakes can aid understanding of larval recruitment dynamics. Here, we integrate a series of climate, hydrodynamic, biogeochemical, and Lagrangian particle dispersion models to: (1) simulate hatch and transport of fish larvae throughout an illustrative large lake, (2) evaluate patterns of historic and potential future climate-induced larval transport, and (3) consider consequences for overlap with suitable temperatures and prey. Simulations demonstrate that relative offshore transport increases seasonally, with shifts toward offshore transport occurring earlier during relatively warm historic and future simulations. Intra- and inter-annual trends in transport were robust to assumed pelagic larval duration and …

Analysis And Design Of Multiport Converters For Photovoltaic And Electrical Vehicle Applications, Reza Rezaii

Graduate Thesis and Dissertation 2023-2024

The widespread adoption of photovoltaic (PV) and electric vehicle (EV) technologies is crucial for mitigating greenhouse gas emissions. A Multi-Port Converter (MPC) connects multiple PV panels, improving efficiency and reducing costs. In EVs, MPCs extend battery lifespan by adding energy sources, enhancing system quality beyond reliance on Li-ion batteries. This dissertation proposes a Quad-input LLC topology for PV microinverters. It utilizes a single LLC resonant tank and two Y switches configurations. An MPPT control strategy based on Perturb and Observe (P&O) method ensures independent MPPT for each panel. The zero-voltage switching (ZVS) is achieved across all switches for wide input …

On The Use Of The Local Reflection Coefficient To Assess The Diffuse Field Sound Absorption Coefficient Of A Porous Material, Franck Sgard, Noureddine Atalla, Olivier Robin

Études primaires

The diffuse field sound absorption coefficient (SAC) of a sound absorber can be obtained from an average over the incidence angles of the oblique incidence plane wave SAC. The plane wave SAC can be derived from the plane wave complex-valued reflection coefficient defined as the ratio of the reflected sound pressure at a given point on the material surface to the incident sound pressure at the same point. In practice, the material is excited by a monopole, and the reflection coefficient becomes a local quantity which is a function of the source height and the radial distance from the source. …

Training Practitioners For Real-Time Product Development Using Generative Artificial Intelligence, Antoine J. Jetter, Ameeta Agrawal, Dahm Mongkol Hongchai, Charles Weber, Yufei Tao

Engineering and Technology Management Faculty Publications and Presentations

A workshop to train practitioners in real-time new product development (NPD) using generative artificial intelligence (AI) was conducted. Three teams of graduate students in Engineering and Technology Management (many with work experience as managers and engineers) were given minimalist instructions to develop a product concept and a preliminary marketing plan for a product of their choosing within six hours using ChatGPT, search engines, and other Internet-based tools. The product was to be novel, and the plan was to include customer identification, market analysis, generating personas, and a 15-minute presentation at the end of the workshop. The goal was to 'inspire …

Developing An Assessment Model For Entrepreneurship Ecosystems Using Hierarchical Decision Model, Mustafa Almuzel, Tugrul U. Daim, Birol Yesilada, Marina Dabic, Gulin Idil Bolatan

Engineering and Technology Management Faculty Publications and Presentations

Entrepreneurship is a crucial driver of economic growth, necessitating the development of effective entrepreneurial ecosystems. However, there are significant gaps in the literature regarding the structured assessment of these ecosystems. This study addresses three main research gaps: the lack of structured evaluation methods, the need for a comprehensive analysis of ecosystem challenges from various perspectives, and the identification of critical factors essential for ecosystem growth. To bridge these gaps, the research introduces the Hierarchical Decision Model (HDM) as a universal assessment framework that can be adapted to different cities for creating effective entrepreneurial environments. The research methodology involved formulating perspectives …

Enhancing Reservoir Modeling And Simulation Through Artificial Intelligence And Machine Learning: A Smart Proxy Modeling Approach, Andrew Timothy Jenkins

Graduate Theses, Dissertations, and Problem Reports (ETD)

The application of numerical reservoir simulation (NRS) has been a common approach within the oil and gas industry for decades, providing a means to model and forecast dynamic subsurface interactions, as a basis for reservoir management and development decisions. These techniques have expanded to application within carbon capture utilization and storage (CCUS) projects as domestic and global policy shift towards reducing carbon emissions while maintaining the energy needs of our modern society. NRS techniques have become a core process for permitting approval in Class VI (large-scale geological sequestration) wells due to the fundamental similarity of these types of subsurface processes. …

Implementation Of Bayesian Statistics To Answer Diverse Engineering Questions: Applications In Cancer Immunology And Engineering Education, Anika C. Pirkey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Quantitative Systems Pharmacology (QSP) refers to a mechanistic modeling approach used for assessing potential therapeutics by linking the molecular and cellular level mechanisms of the disease and therapeutic to the system-wide dynamics and clinical endpoints relevant to the disease. Although the field of QSP is still in its relative infancy, the mathematical methodology employed to predict the kinetics of these systems are not new and can be applied to a wide variety of systems. For instance, similar to QSP’s goal of guiding the development of novel therapeutics for various disease states, there exists a need to develop novel interventions in …

Inherently Porous Metal Structures With Sufficient Mechanical Properties Through Direct Writing Of Bio-Based Inks, Havva Eda Aysal

Graduate Theses, Dissertations, and Problem Reports (ETD)

There is currently a burgeoning interest in developing 3D printed metal structures with inherent porosity and sufficient mechanical properties for mass customization in the biomedical field. Current approaches for 3D printing of biocompatible metals rely on powder-bed fusion methods which are energy intensive and utilize large amounts of metal powder that is challenging to recycle. In addition, such methods aim on producing dense parts and porosity generation, within the printed part, is challenging due to the complex physics of the melting pool. Here, a relatively new and promising approach is undertaken to study the 3D printing of inherently porous structures …

On Uncertainty For Ill-Posed Robot Decision Problems, Jared Joseph Beard

Graduate Theses, Dissertations, and Problem Reports (ETD)

As robots adopt more real world responsibilities, they will be expected to solve more complicated problems. In some cases limited prior knowledge will result in unmodelled environmental conditions; in others, multiple users may have competing perspectives on how to frame a decision problem. Many existing frameworks, namely Markov decision processes (MDP) presuppose users have identified a specific problem with models sufficient to solve or learn a problem. If we wish to extend MDPs to novel problems or those heavily dependent on user feedback, autonomous decision makers must be able to identify limitations in how a given problem is framed and …

Triggered Online System Re-Identification Applied To Model Predictive Control Using Gaussian Processes, Daniel Augusto Kestering

Graduate Theses, Dissertations, and Problem Reports (ETD)

Safety, product quality, enhanced performance, and increased profit all depend on the control of chemical and energy processes. However, operational issues can lead to control challenges, especially when processes are subject to disturbances during their operation. Process control methods work best when processes operate close to their designed operat- ing conditions, but lack of performance or other issues may occur when the process is far from such conditions. To overcome these challenges, in this dissertation, online model re- identification is proposed for Model Predictive Control (MPC). This involves reassessing the predictive model of an advanced controller, namely MPC, when re-identification …

Performance And Field Testing Of Geotextiles For Dewatering Rare Earth Element Hydraulic Preconcentrate From Hardrock Amd, Ian R. Bird

Graduate Theses, Dissertations, and Problem Reports (ETD)

As part of ongoing efforts to develop a domestic Rare Earth Elements (REE) supply chain the Hydraulic Preconcentrate (HPC) produced at the Horseshoe bend treatment plant (HsB) was manufactured and evaluated as a potential source for feedstock. After the existing clarifiers on the site were flipped to the desired pH set points, HPC was manufactured and pumped to 24 geobags. The geobags were then passively dewatered to increase the total solids percentage. The geobags evaluated were comprised of: Woven geotextiles, composite (woven and non- woven), and geobags augmented with Capillary Channel Fiber (CCF). Column Filtration Tests (CFTs) were performed onsite …

Benchmarking The Global Warming Potential Of Asphalt Pavements In West Virginia, Md Reasad Samrat

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the rising focus on sustainable infrastructure, interest in environmentally friendly paving practices has grown significantly. This thesis investigates the environmental impacts of asphalt mixtures in West Virginia from a sustainable asphalt mix design perspective, with a particular emphasis on the utilization of Life Cycle Assessment (LCA). The research aligns with the U.S. Federal Highway Administration (FHWA) Climate Challenge, which aims to encourage state Departments of Transportation (DOTs) to implement low-carbon materials and consider the ecological effects of their paving activities. This study establishes the initial benchmark values for greenhouse gas emissions associated with asphalt pavements in West Virginia. The …

Groundwater Movement In Boiling Spring, Onyx Spring, Yelton Spring, Wilkins Spring, Hudgens Spring And Natural Bridge Spring, Katherin Roxana Montes Chamorro

Masters Theses

"Onyx Spring, Boiling Spring, Yelton Spring, Wilkins Spring, Hudgens Spring, and Natural Spring are located on public land in Pulaski and Phelps County, Missouri. They were selected randomly to determine groundwater movement and compare water chemistry from the springs that are connected.

Using a dye tracing method, we were able to determine the direction of groundwater flow and a water multiparameter sonde was used to characterize the water chemistry at each point of the springs. As a result, from the six springs studied only three springs are connected which are Yelton, Onyx and Boiling Spring. Regarding to water chemistry this …

Theoretical Modeling And Experimental Investigation Of Phase Selection During Rapid Solidification Of Alloys, Azeez Aremu Akinbo

Masters Theses

"A novel model, rooted in time-dependent nucleation theory, has been created to explore how rapid solidification affects the extended solubility in metal alloys. This model was used to forecast solubility concerning undercooling in multiple binary aluminum (Al) alloys, and its predictions for both eutectic and peritectic systems closely match experimental data. It was demonstrated that this developed model surpasses the T0 line method, which does not consider the kinetic aspects of nucleation. Furthermore, the model can be extended to ternary and multicomponent phases by assuming that the scarcest element or the slowest diffusing component restricts nucleation. Al-Cu and Al-Cr, vital …

Zips Baja Zb25 Frame, Elijah Shelhart

Williams Honors College, Honors Research Projects

This report outlines the design and validation of a new frame for the University of Akron Zips Baja team’s 2025 competition vehicle. This project represents the first comprehensive redesign of the frame in over a decade, addressing critical issues such as weight and manufacturability identified in previous designs. Utilizing SolidWorks for 3D modeling and Ansys for static simulations, the frame was iteratively improved to ensure structural integrity and compliance with SAE competition rules. The final design achieved a weight reduction of approximately 10 pounds compared to the previous frame while maintaining required safety factors in frontal, rear, rollover, and torsional …

Enhancing Pricing Practices Of Subcontractors: A Comparative Analysis Using Simulation Modeling, Muaz O. Ahmed, Islam H. El-Adaway, Kalyn T. Coatney

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The construction industry often relies on subcontracting, where subcontractors bid for portions of a project before general contractors bid for the entire project in a process referred to as multi-stage bidding (MSG). MSG can be complex, and winning bidders may be burdened with underestimating their bids and encountering the winner's curse. Despite various studies investigating this issue, further research is necessary to examine bidding strategies for subcontractors. This paper addresses this research need by exploring and comparing how bidding strategies based on reinforcement learning and game theory could aid subcontractors in mitigating the winner's curse in MSG. The authors used …

Fabrication And Analysis Of A Gas Sensor Utilizing A Fabry-Perot Interferometer With Varied Thicknesses Of Zif-8 Coating On End-Faced Single-Mode Optical Fiber, Nahideh Salehifar, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research investigates the potential of integrating optical fiber and sensitive thin film coating materials to develop diverse chemical sensing platforms. We utilized a layer-by-layer synthesis technique, along with specific pre- post treatment methods, to create highly effective nonporous metal-organic frameworks (MOFs), specifically ZIF-8, ranging from the nanometer scale to the micrometer scale (800 nm to 110 μm). Additionally, we successfully cultivated ZIF-8 on both sides of a single-mode fiber (SMF) with thicknesses of 25 μm and 50 μm. In a separate experiment, we successfully grew ZIF-8 on one side of an optical fiber, achieving a thickness of 10 μm. …