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Improving Cast Steel Rail Coupler Fatigue Resistance Through Local Wire-Arc Additive Manufacturing, Andrew M. Bunge

Dissertations, Master's Theses and Master's Reports

Every year, thousands of cast-steel railcar couplers suffer from corrosion-initiated fatigue cracking in similar areas of the coupler’s knuckle; between 2015 and 2018 about 90,000 knuckles were replaced, otherwise these couplers would have been at risk for unexpected failures. These types of couplers have been common in industrial use as early as 1932, hence it is desirable for a countermeasure to the fatigue cracking that does not involve significantly altering the geometry or casting process. Wire arc additive manufacturing (WAM) is a developing technology which boasts the ability to produce complex near-net-shape components; however, less attention has been paid to …

Directional Dependent Fracture Characteristics Of 3d Printed Mechanical Metamaterials, Thomas Draper

Dissertations, Master's Theses and Master's Reports

Structural metamaterials, such as lattice metamaterials, are engineered cellular structures designed to achieve properties not achievable by natural materials. They enable mechanical properties unattainable by homogeneous solid materials and offer optimal properties for these materials tunable for specific applications in industries such as automotive, medical, and aerospace. Recent findings have revealed unique tunable mechanical properties such as negative Poisson's ratio, high strength-to-weight ratio, anisotropic stiffness, and much more. While the elastic and wave propogation properties of many lattice metamaterials are well investigated, the fracture properties are not well explored. However, their low fracture toughness is a bottleneck for their use …

Synthetic Microbial Communities For Plastic Upcycling, Isabel B. A. Valencia

Dissertations, Master's Theses and Master's Reports

Plastic waste and human hunger pose major threats to the health and wellbeing of populations world-wide. Using microbial methods to upcycle polyethylene terephthalate (PET) plastic into value-added compounds such as single cell protein (SCP) for human consumption is a unique solution to both these issues. Two monomers of chemically deconstructed PET (DCPET), terephthalate (TPA) and ethylene glycol (EG), have been previously shown to be biodegradable by enriched microbial communities. Using this top-down knowledge to inform the reconstruction of a minimal microbial community constructed from isolated members of these communities is a novel way to efficiently process these monomers via a …

Analysis Of Energy Consumption And Water Utilization For Carbon Dioxide Dissolution In Scrubbing, Nanobubble, And Membrane Technologies Under Various Operating Conditions, Raliba Hinga Rosaline

Dissertations, Master's Theses and Master's Reports

The increase in anthropogenic emissions of greenhouse gases, especially carbon dioxide (CO2), has caused global temperatures to rise, requiring the implementation of effective solutions to mitigate the carbon emissions such as Carbon Capture and Storage (CCS). Even though CCS holds potential, there are concerns surrounding the capacity for CO2 storage and the potential for leakage. This study investigates the water utilization and energy consumption for the dissolution of captured CO2 of three technologies -scrubbing, nanobubble and membrane technologies. We constructed a spreadsheet model utilizing Henry's law to forecast the amount of water needed and energy used for each technology considering …

Changes In Flanker Task Performance Following High-Intensity Exercise In Endurance Athletes, Felix E. Cottet-Puinel

Dissertations, Master's Theses and Master's Reports

Executive function performance following acute aerobic exercise can be influenced by multiple variables. However, little is known about the lasting effects of these exercise-induced changes. This study aimed to determine the extent to which exercise intensity impacts executive function. 14 young endurance-trained adults (5 female, 9 male) performed an Eriksen flanker task before and immediately after running high-intensity until failure and isochronal moderate-intensity (~12 min). Pre- to post-exercise-induced changes in reaction time (ms), accuracy (%), and self-reported mental effort (1-9 rating) were analyzed by overall tasks and through tasks subsections. Results showed improvement in reaction time following high- and moderate-intensity …

Mechanical Properties And Cycling Fatigue Of Zn-Based Alloys: Effects Of Thermal Treatment, Henry D. Summers

Dissertations, Master's Theses and Master's Reports

Zinc (Zn)-based alloys are attractive candidate materials for constructing bioresorbable coronary stents because of their near-ideal corrosion properties and biocompatibility. These alloys are primarily strengthened through alloying and thermomechanical processing by solid solution strengthening, grain refinement, and precipitate strengthening. The microstructural features responsible for these strengthening mechanisms are controlled through the thermal treatment of the alloys. While the static mechanical properties of Zn alloys have been studied, a gap in the literature remains related to their mechanical stability under dynamic loading conditions (fatigue) and creep, especially while subjected to physiological conditions. This work aims to characterize the effects of thermal …

High Temperature Strength Reduces Soldering In Aluminum High Pressure Die Casting, Jacob A. Belke

Dissertations, Master's Theses and Master's Reports

Die soldering, an adhesion defect in high pressure die casting (HPDC), is a symptom of localized sticking where a localized portion of the cast material is adhered to the tooling surface causing build up over time. This requires the tooling to be serviced which incurs additional costs to the process that gets passed on to the parts. Historically, soldering has been mitigated using lubricants, coatings, and alloy chemistry modifications but solder persists.

The Tresca friction thermomechanical model suggests soldering occurs when the local interfacial shear stress between the casting and die surface exceeds the local shear strength of the casting. …

From Technical Resolution To Agile Evolution: A Blended Role At Humane Interface Design Enterprise (Hide), Ketansingh Anil Patil

Dissertations, Master's Theses and Master's Reports

This report provides a comprehensive overview of my journey through two distinct roles at the Humane Interface Design Enterprise (HIDE) - as a Technical Consultant in Spring 2023 and an Agile Process Analyst in Fall 2023. My tenure as a Technical Consultant was marked by the application of academic knowledge and technical skills to tackle real-world challenges at HIDE, leveraging experiences from my capstone projects and my roles in the industry as an IT Analyst Intern at Milwaukee Tool and a Data Engineer at UST. This role at HIDE enhanced my problem-solving skills and contributed to the progress of the …

Assessing Wave Dynamics Induced Coastal Flooding Along The Southern Shores Of Lake Superior, Saumik Mallik

Dissertations, Master's Theses and Master's Reports

This study provides a comprehensive assessment of coastal hazards along the southern shores of Lake Superior, encompassing the interplay of static water levels, surges, and the amplifying effects of wave dynamics. Employing 51 years of historical water level data from five gauge stations in the US portion of Lake Superior, the study conducts extreme value analysis to estimate return levels over various return periods (25, 50, 100, and 500 years) for static water levels and surges. In parallel, Significant Wave Heights (SWH) data generated from the Simulating Waves Nearshore (SWAN) model is calibrated through a multi-step procedure based on historical …

Computational Evaluation Of Some Basic Material Parameters In Cobalt-Aluminum Alloys, Hemanth Kumar Reddy Basireddy

Dissertations, Master's Theses and Master's Reports

The First Principles Density Functional Theory study is conducted on BCC Co-Al based solid solution which obeys Vegard’s law. Chemical bond energies are calculated beyond 1NN interactions as second-nearest-neighbor and third-nearest-neighbor chemical bond energy values are significant and contribute to the total energy of the alloy. Elastic energy developed in the alloys due to the atomic radius misfit between solute and solvent atoms is also considered. Effects of atomic ordering on 1NN, 2NN, and 3NN chemical ordering energies and lattice parameters are investigated.

On Graph Decompositions And Designs: Exploring The Hamilton-Waterloo Problem With A Factor Of 6-Cycles And Projective Planes Of Order 16, Zazil Santizo Huerta

Dissertations, Master's Theses and Master's Reports

This dissertation tackles the challenging graph decomposition problem of finding solutions to the uniform case of the Hamilton-Waterloo Problem (HWP). The HWP seeks decompositions of complete graphs into cycles of specific lengths. Here, we focus on cases with a single factor of 6-cycles. The dissertation then delves into the construction of 1-rotational designs, a concept from finite geometry. It explores the connection between these designs and finite projective planes, which are specific geometric structures. Finally, the dissertation proposes a potential link between these seemingly separate areas. It suggests investigating whether 1-rotational designs might hold the key to solving unsolved instances …

The Integration Of Neuromorphic Computing In Autonomous Robotic Systems, Md Abu Bakr Siddique

Dissertations, Master's Theses and Master's Reports

Deep Neural Networks (DNNs) have come a long way in many cognitive tasks by training on large, labeled datasets. However, this method has problems in places with limited data and energy, like when planetary robots are used or when edge computing is used [1]. In contrast to this data-heavy approach, animals demonstrate an innate ability to learn by communicating with their environment and forming associative memories among events and entities, a process known as associative learning [2-4]. For instance, rats in a T-maze learn to associate different stimuli with outcomes through exploration without needing labeled data [5]. This learning paradigm …

Machine Learning For Electronic Structure Prediction, Shashank Pathrudkar

Dissertations, Master's Theses and Master's Reports

Kohn-Sham density functional theory is the work horse of computational material science research. The core of Kohn-Sham density functional theory, the Kohn-Sham equations, output charge density, energy levels and wavefunctions. In principle, the electron density can be used to obtain several other properties of interest including total potential energy of the system, atomic forces, binding energies and electric constants. In this work we present machine learning models designed to bypass the Kohn-Sham equations by directly predicting electron density. Two distinct models were developed: one tailored to predict electron density for quasi one-dimensional materials under strain, while the other is applicable …

Investigation Of Operational Parameter Differences Between The Standard Ron Test Method And Knock-Limited Modern Spark-Ignition Engine Operation, Alexander Hoth

Dissertations, Master's Theses and Master's Reports

Octane numbers (ONs) are used worldwide to rate the knock propensity of gasoline-like fuels for spark-ignition engines, making ONs the leading indicator of fuel quality for commercial distribution. The ONs were established 90 years ago and have only received minor changes compared to significant advancements in modern engine operation and fuel composition. This has resulted in discrepancies between knock-limited modern engine operation and standard ON ratings. This dissertation used a standard CFR octane rating engine at Argonne National Laboratory that was instrumented with modern combustion research tools to investigate key differences between the Research Octane Number (RON) rating conditions and …

Gis-Based Landscape Prioritization To Guide Invasive Species Survey, Erin R. Mauk

Dissertations, Master's Theses and Master's Reports

Utilizing prioritization models gives invasive species managers the capability to systematically target surveying and management toward priority areas, therefore maximizing limited financial resources by increasing the value that management can have on the landscape. In this report, Geographic Information System (GIS) techniques were utilized to produce an invasion risk model and a quality land model. Combining these two models produced a landscape-level prioritization model, which denoted the land quality and associated invasion risk across the study area. High-quality land was commonly distributed within Isle Royale National Park, along Lake Superior’s coastline, and within coastal wetlands and riparian habitats. Areas of …

Sea Level Rise Driven Groundwater Inundation: Effects Of Island Hydrogeology On Freshwater Lens Dynamics, Lauren K. Mancewicz

Dissertations, Master's Theses and Master's Reports

Groundwater inundation due to sea level rise poses a threat to fresh groundwater availability in coastal areas, and small islands are particularly vulnerable. On an island, when sea level rises, the freshwater lens also rises due to the difference in density between the salt and fresh groundwater. As the water table rises above the land surface it forms a lake and the water is exposed to additional evaporative losses, reducing the amount of fresh water available. This work aims to improve our understanding of groundwater inundation due to sea level rise and the impact of different hydrogeologic settings and phenomena …

Nickel Superalloy Composition And Process Optimization For Weldability, Cost, And Strength, Sophie A. Mehl

Dissertations, Master's Theses and Master's Reports

To advance sustainability efforts, electric power plants have reduced specific carbon dioxide emissions by increasing operating temperatures and pressures to improve power generation efficiency. The latest improvements are utilized in advanced ultra-supercritical power generation. To meet these operating conditions, nickel superalloys are used in the highest temperature components; however, they are expensive and present weldability challenges. This project aims to experimentally optimize a nickel superalloy to improve material weldability and decrease cost without compromising strength. Three optimized compositions were developed, and their microstructures and mechanical properties were compared to Nimonic 263, a common nickel superalloy in electric power plants. The …

Integrating Arcgis And Redux Using Middleware, Vishnu Vardhan Reddy Rapuru

Dissertations, Master's Theses and Master's Reports

The integration of ArcGIS with Redux through middleware presents a novel approach to managing state in geospatial applications. This report outlines the process and benefits of combining ArcGIS’s robust mapping and analytics capabilities with Redux’s predictable state container for JavaScript apps. It begins with an introduction to both technologies, followed by a detailed discussion on the architecture design, focusing on the role of middleware as the linchpin in this integration[1]. The paper highlights the benefits, such as improved state management and application performance, and addresses the challenges encountered during the integration process. Implementation details are provided, including the setup of …

Restoration Is Repairing Relationships: Bridging Indigenous And Western Sciences To Assess The Socio-Ecological Restoration Of Wild Rice (Zizania Palustris) On Keweenaw Bay Indian Community Homelands, Cassandra M. Reed-Vandam

Dissertations, Master's Theses and Master's Reports

Manoomin (wild rice, Zizania palustris) is an ecologically and culturally significant plant relative for the Keweenaw Bay Indian Community (KBIC). Historically, manoomin was present across much of the Great Lakes, however, their presence has declined since the early 1900s and, by 1990, virtually disappeared within KBIC homelands. Employing ethnography, surveys, focus groups, and conversations with Ojibwa knowledge holders, this research defined successful manoomin restoration for KBIC and developed socio-ecological attributes and indicators to assess restoration presented in the Medicine Wheel Framework for Manoomin Restoration. Surface water, sediment, and pore water samples at six different manoomin sites were analyzed to …

Dependence Of Energy Transfer On Curvature Similarity In Collisions Involving Curved Shock Fronts, Justin Cassell

Dissertations, Master's Theses and Master's Reports

In high-speed collisions of projectiles, pressure exerted by a resulting shock wave is so high that even solids begin to flow and hydrodynamics becomes relevant. Jetting results from hydrodynamic instability driving the evolution of an interface following shock loading. Our emphasis in this dissertation is mitigation of instabilities via several shocks and, specifically, the transfer of energy from a shock wave to another object. To that end, in 2022 and 2023 while on-site, we adapted Lawrence Livermore National Laboratory (LLNL) to explore the effects of shock front geometry on the transfer of energy during shock collisions via numerous computer simulations. …

An Examination Of Scientific And Technical Communication For Forensic Engineering And Forensic Pathology., Tori C. Reeder

Dissertations, Master's Theses and Master's Reports

Police communication sits at the unique intersection of risk communication, scientific and technical communication, and medical communication, as we see in forensic reports. In this dissertation, I examine the communicative underpinnings of forensic pathology and forensic engineering reports. I argue that there is not only an inherent link between the unpredictability of a written text and the reception of said text by both its intended and unintended audience, but also a link to the broader socio-cultural contexts. I will examine an atypical forensic pathology report (autopsy report) of George Floyd, a more standard forensic pathology report of an inmate who …

The Implications Of Waste Streams At Camp Au Train, Timothy J. Maze

Dissertations, Master's Theses and Master's Reports

Archaeological remains from Camp Au Train provide an opportunity to understand sanitation methods during its use as a Civilian Conservation Corps camp and later used to house German Prisoners of War during World War II. Seven refuse features from this camp were excavated and their contents linked to functional locations within the camp in order to reconstruct waste streams across the site and to observe how military aspects of sanitation were implemented by an organization infamous for its emphasis on cleanliness, order, and hygiene. While the importance of sanitation is often mentioned by historians and archaeologists in research of these …

“Not Much Of A Job”: Everyday Life And Labor At Camp Au Train, Josef T. Iwanicki

Dissertations, Master's Theses and Master's Reports

In this thesis, I use data from Camp Au Train, a Civilian Conservation Corp camp in Michigan’s Hiawatha National Forest, as a case study to connect the everyday life of enrollees with dominant government narratives while including a focus on labor and the capitalist crisis of the Great Depression. Using the vantage point of work, play, study, and health, I integrate archaeological, historic, and photographic evidence to show contradictions between the enrollees’ real lived experience and the dominant perspectives of the CCC ‘authorities’ who organized their lives. I argue that to interpret these contradictions, the CCC needs to be connected …

Data Driven And Machine Learning Based Modeling And Predictive Control Of Combustion At Reactivity Controlled Compression Ignition Engines, Behrouz Khoshbakht Irdmousa

Dissertations, Master's Theses and Master's Reports

Reactivity Controlled Compression Ignition (RCCI) engines operates has capacity to provide higher thermal efficiency, lower particular matter (PM), and lower oxides of nitrogen (NOx) emissions compared to conventional diesel combustion (CDC) operation. Achieving these benefits is difficult since real-time optimal control of RCCI engines is challenging during transient operation. To overcome these challenges, data-driven machine learning based control-oriented models are developed in this study. These models are developed based on Linear Parameter-Varying (LPV) modeling approach and input-output based Kernelized Canonical Correlation Analysis (KCCA) approach. The developed dynamic models are used to predict combustion timing (CA50), indicated mean effective pressure (IMEP), …

Applications Of Independent And Identically Distributed (Iid) Random Processes In Polarimetry And Climatology, Dan Kestner

Dissertations, Master's Theses and Master's Reports

The unifying theme of this thesis is the characterization of “perfect randomness,” i.e., independent and identically distributed (IID) stochastic processes as these are applied in physical science. Two specific and mathematically distinct applications are chosen: (i) Radar and optical polarimetry; (ii) Analysis of time series in meteorology. In (i), IID process of a special kind, namely, with a distribution defined by symmetry, is used to link its multivariate Gaussian density to uniformity on the Poincaré sphere. This “statistical ellipsometry” approach is then used to relate polarimetric mismatches or imbalances to ellipsometric variables and suitably chosen cross-correlation measures. In (ii), recently …

Using A Reverse Visually Guided Reaching Task To Distinguish Between Healthy Aging And Early Alzheimer’S Disease, Brandon Woolman

Dissertations, Master's Theses and Master's Reports

Changes in motor behavior may function as a proxy for cognitive decline. While Alzheimer's disease (AD) is associated with impairments in learning and memory, recent studies suggest that subtle changes in motor task performance may reflect early cognitive changes. For example, the visuomotor rotation task that manipulates visual feedback about hand position during reaching movements, can be used to examine cognitive changes in aging populations. The current study used the reverse visually guided reaching task (rVGR) which rotates visual feedback of participant’s hand position 180⁰ relative to the actual hand position. We sought to expand on previous literature by recruiting …

Understanding Subtle Gender Bias Recognition Among Witnesses In A Stem Undergraduate Context, Darnishia Lashalle Morris

Dissertations, Master's Theses and Master's Reports

This dissertation builds on knowledge of how witnesses recognize subtle gender bias (often referred to as gendered microaggressions) in a STEM undergraduate context. This body of work provides a better understanding of the implications of observing these events of subtle bias and the role that recognition plays in providing opportunities to adopt stereotype defying behaviors. The impressions and influences on both witnesses who belong to the marginalized group (target witnesses) and those in majority groups (non-target witnesses) were examined. Three interrelated studies explored how recognition might disrupt the cyclic impact of subtle gender bias when participants witness collaborative STEM team …

Is The Magic In The Hands Or Eyes? Studying The Effects Of Driver Monitoring Strategies On Situation Awareness, Mind Wandering, And Change Detection Behavior In Low And Medium Fidelity Semi-Automated Driving Environments, Shruti Amre

Dissertations, Master's Theses and Master's Reports

Advanced Driver Assist Systems (ADAS) are SAE level 2 features that require active driver control while engaged. Although drivers can have their feet off the pedals and hands off the steering wheel, they must maintain supervisory control of the vehicle. However, when these features are in use, drivers may become less aware of their surroundings, increasing the risk of accidents. To counter this problem, vehicle manufacturers use driver monitoring strategies to ensure drivers remain attentive while ADAS features are active. These monitoring strategies employ instructions to ensure drivers are engaged in the driving task. These instructions are broadly classified into …

A Physical Test Artifact For Evaluating Edge Cases Of Individual And Fused Automated Driving Perception Sensors, Colin Schaefer

Dissertations, Master's Theses and Master's Reports

With the advent of technologies to support autonomous vehicles (AVs), the number of different AV models from a variety of companies and organizations has proliferated. With this increase in options comes the need to physically evaluate their perception systems. However, there is a lack of standard methods to physically evaluate these perception systems. A set of test artifacts can be used to compare the performances of perception systems, but the artifacts must be usable with different types of perception sensors and various sensor fusion systems. This thesis presents the development of an artifact that injects edge case scenarios into the …

Engineering Self-Efficacy And Spatial Visualization: Connecting The Spatial Dots, Katrina L. Carlson

Dissertations, Master's Theses and Master's Reports

Questions exist as to why students in the ENG 1002: Introduction to Spatial Visualization (Spat Vis) course, an intervention course at Michigan Technological University (MTU), have historically attained higher average grades in their first year STEM courses, such as Engineering I and II, calculus I and II, computer science, and chemistry courses. Research shows the retention rate, especially of women, is higher for students who have taken Spatial Visualization. One possible explanation for these observed benefits may be related to the students’ confidence in their ability (self-efficacy) to gain the engineering graphics skills needed to become an engineer. No work …