Digital Commons Network^™

The Application Of Leaky Wave Antennas For Medical Hyperthermia Treatment And Beamformer In Fmcw Automotive Radar Systems, Masoud Sarabi

Dissertations, Master's Theses and Master's Reports

Thousands of years ago human discovered that if a slice of amber is rubbed against fur, it would absorb light-weight objects. Hundreds of years after that the ancient people figured out that there are actually two different characteristics of attraction and repulsion. Another 2000 years passed when human discovered that these two wonders of nature, magnetism and electricity are actually linked together like the two sides of the same coin. Since then, in the early 19th century great huge achievements were made in antennas and propagation by scientists such as Hans Christen Oersted, Heinrich Hertz, Alexander Popov and Marconi. Since …

Commissioning And Testing Of A New Dusty Thermal Vacuum Chamber, Ben Wiegand

Dissertations, Master's Theses and Master's Reports

The Dusty Thermal Vacuum Chamber (DTVAC) is a new facility purchased by the Planetary Surface Technology Development Lab (PSTDL) that will be used to test the Technology Readiness Level (TRL) of extraplanetary devices and systems. With the use of vacuum pumps and simulated regolith, the DTVAC can create extraplanetary environments such as those found on the Moon and Mars. This report details the actions that were taken to prepare the DTVAC for TRL testing, including the development of a Data Acquisition Center (DAC) and test fixtures, along with the findings of baseline tests that were performed to understand the behavior …

‘Owing To The Backwardness Of The Season’: Assessing The Exploratory Mining Process On Isle Royale Redacted Version, Andrew Anklam

Dissertations, Master's Theses and Master's Reports

Isle Royale, located in Lake Superior, was one center of the nation’s first copper rush. High quality copper veins drew mid-19th century miners looking to stake a claim. By the mid-1850s these initial attempts at lode mining failed as the remote location and logistical hurdles made extracting copper from Isle Royale a costly business. Despite the short-lived nature of these exploratory mines, they played a vital role in defining the nature and profitability of copper lodes in the Lake Superior Basin and serve as an example for how mineral rushes on the western frontier of North America play out. The …

Modeling And Numerical Simulations Of The Michigan Tech Convection Cloud Chamber, Subin Thomas

Dissertations, Master's Theses and Master's Reports

Understanding atmospheric clouds is essential for human progress, ranging from short-term effects such as when and how much it rains to long-term effects such as how much temperatures would rise due to global climate change. Clouds vary globally and seasonally; also they have length scales ranging from a few nanometers to a few kilometers and timescales from a few nanoseconds to a few weeks. Knowledge gaps in aerosol-cloud-turbulence interactions and a lack of sufficient resolution in observations pose a challenge in understanding cloud systems.

Experimental facilities like the Michigan Tech Cloud Chamber can provide a suitable platform for studying aerosol-cloud …

Chinese Women’S Reproductive Justice And Digital Technologies, Hua Wang

Dissertations, Master's Theses and Master's Reports

It is well known that China has implemented a Family Planning policy. Chinese women have limited options in reproduction, and their agency is constrained by the government, the medical institutions, and the traditional Chinese patriarchal and biased culture. By utilizing rhetorical analysis as a primary methodology with a focus on rhetorical agency, this dissertation analyzes two cases where digital technologies such as social media and apps facilitate users’ rhetorical agency to counter instances of reproductive injustice. First, I focus on China’s most popular pregnancy and mothering app, Babytree, to examine how the app rhetorically positions its users to enable empowerment …

New Numerical Approximations Of Geological Processes In Heterogeneous Systems Using Radial Basis Functions, Nadun Lakshitha Dissanayake Kulasekera Mudiyanselage

Dissertations, Master's Theses and Master's Reports

This dissertation includes four chapters. A brief description of each chapter is organized as follows. The first chapter provides an introduction to the RBF method. The chapter follows the historical progression of the Radial Basis Function (RBF) method while outlining the method’s advantages and disadvantages. A brief introduction about RBF interpolation, the RBF-FD method, and how to use it to solve PDEs is provided. Chapter 2 introduces a novel computationally efficient RBF-FD algorithm to solve the groundwater flow equation in the presence of an active well. We show that our method analytically handles the singularities in the PDE caused by …

Statistical Methods In Genetic Studies, Cheng Gao

Dissertations, Master's Theses and Master's Reports

This dissertation includes three Chapters. A brief description of each chapter is organized as follows.

In Chapter 1, we proposed a new method, called MF-TOWmuT, for genome-wide association studies with multiple genetic variants and multiple phenotypes using family samples. MF-TOWmuT uses kinship matrix to account for sample relatedness. It is worth mentioning that in simulations, we considered hidden polygenic effects and varied the proportion of variance contributed by it to generate phenotypes. Simulation studies show that MF-TOWmuT can preserve the type I error rates and is more powerful than several existing methods in different simulation scenarios, MFTOWmuT is also quite …

Marangoni Propulsion Of Active Particles, Saeed Jafari Kang

Dissertations, Master's Theses and Master's Reports

We study the surfing motion of active particles located at a flat liquid-gas interface. The particles create and maintain a surface tension gradient by asymmetrically discharging a surface tension-reducing agent. We employ theory and numerical simulation to investigate the Marangoni propulsion of these active surfers. First, we use the reciprocal theorem to establish a relationship between the propulsion speed and the release of the active chemical. This theoretical relation is utilized to examine the effect of wall confinement and geometry on the Marangoni-driven motion of active particle when the inertial effects are negligible and when the transports of the released …

Predictors Of Academic Performance: The Roles Of Self-Compassion, Coping, Mental Toughness, Grit, And Self-Reported Stressors On Physics Final Exam Performance, Darnishia L. Morris

Dissertations, Master's Theses and Master's Reports

The intersection of stress, persistence and success in college-aged students is progressively gaining attention in research. Analyzing how students succeed and what factors contribute to their success, failure, and ultimately the completion of their degree, is vitally important for educators and administrators in higher education to understand. Historically utilized factors such as grade point average (GPA), standardized test scores (college admissions and Advance Placement (AP) exams), and previous academic achievement (pre-requisite courses) are not the only predictors of academic performance. This study aimed to quantify contributions and inter-relationships of student perceptions, coping style, stress, mental toughness (MT), and other potential …

The Effects Of Molybdenum, Chromium, And Niobium On Gray Iron For Brake Rotor Applications, Matthew Hasbrouck

Dissertations, Master's Theses and Master's Reports

Brake rotor composition and microstructure must be optimized for thermal and mechanical performance to avoid thermal-mechanical cracking, excessive wear, and to reduce noise. Niobium is an element that increases the strength and wear resistance of gray iron; however, the interaction of niobium with other common alloying elements (chromium and molybdenum) is not well understood. Thirteen gray cast iron alloys were produced with varying levels of carbon equivalent (CE), Cr, Mo, and Nb. Bars with four different diameters (8, 14, 22, and 30 mm) were cast from each alloy and microstructural and physical properties such as graphite flake morphology, pearlite spacing, …

Novel New Modeling Procedure For Industrial Machinery With Nonlinear Connections, Steven Whitican

Dissertations, Master's Theses and Master's Reports

Given current timelines for rolling out production at volume, the ability to model portions of the production process is of paramount importance. To model production, high-fidelity models of production assets must be obtained. The production assets are comprised of linear and nonlinear structures. The linear structures are well understood and defined. Significant work has, and is, being done to understand the nonlinear components. This work focuses on developing and correlating a model of a nonlinear component. The component studied and modeled is a linear guide. Linear guides are bearings which facilitate translational motion of machine axes. An accurate model of …

Modeling Human Visual Detection Using Deep Networks, Zach Dekraker

Dissertations, Master's Theses and Master's Reports

The work in this report describes the use of machine learning to model human visual detection. This is in contrast to typical machine learning models, which seek to optimize detection performance overall, e.g., precision versus recall or F1 scores. Instead the goal is to develop models that can accurately match humans' abilities to detect objects in images. There are many AI algorithms that have far surpassed humans in, for example, object detection in large image databases or games such as Go. What is different about this work is that the objective is to accurately model humans' performance in visual detection …

Multi-Dimensional Modeling For Environmental Impact Assessment At Intersections Of The Food-Energy-Water Nexus, Jessica Daignault

Dissertations, Master's Theses and Master's Reports

This dissertation uses multi-dimensional modeling for environmental impact assessment at intersections of the Food-Energy-Water (FEW) Nexus, including life cycle assessment (LCA) modeling for quantification of environmental impacts due to household FEW consumption, a linear regression framework for quantification of water-use impacts of marginal electricity generation, and a multi-objective optimization model to assess monetization of water withdrawals for electricity generation and impacts to water stress due to electricity dispatch schemes. Chapter 2 of this dissertation summarizes the development of an LCA model that quantifies the direct and indirect environmental impacts of household FEW consumption. The model is executed through a novel …

Spatial And Temporal Comparison Of Persistent Organic Pollutants In The Boardman River, Collin Diedrich

Dissertations, Master's Theses and Master's Reports

Dam removal is a critical part of river and stream remediation projects around the world. Frequently dams are associated with impoundment ponds containing sediments that can act as a sink of various persistent organic pollutants (POPs) that can pose risks for human and aquatic wildlife. In this study, we deployed semi-permeable membrane devices (SPMDs) at multiple locations along a 25-mile stretch of the Boardman River in Traverse City Michigan to passively sample POP concentrations in this area that has recently undergone dam and impoundment pond sediment removal. Concentrations of polychlorinated biphenyl (PCB), di-chloro-diphenyl-trichloroethane (DDT) and cyclodiene compounds were in the …

Development Of A Method To Model An Enclosed, Coaxial Carbon Nanotube Speaker With Experimental Validation, Suraj Prabhu

Dissertations, Master's Theses and Master's Reports

Carbon nanotube (CNT) speakers operate on heat as compared to conventional loudspeakers that operate on vibration. CNT speakers are extremely lightweight, stretchable, flexible, and have high operating temperatures. Due to these advantages, CNT speakers are being considered as a viable replacement option for conventional loudspeakers. One such application is automotive exhaust noise control. The goal of this research is to design an enclosed, coaxial CNT speaker and to develop a modeling method to model this speaker using COMSOL Multiphysics.

As part of this research, an enclosed, coaxial CNT speaker was designed and manufactured for automotive exhaust noise control. The first …

Open-Source Tig-Based Metal 3d-Printing, Shane Oberloier

Dissertations, Master's Theses and Master's Reports

Metal 3-D printing has been relegated to high-cost proprietary high-resolution systems and low-resolution low-cost metal inert gas (MIG) systems. In order to provide a path to high-resolution, low-cost, metal 3-D printing, this manuscript proposes a new open source metal 3-D printer design based around a low-cost tungsten inert gas (TIG) welder coupled to a commercial open source self replicating rapid prototyper. Optimal printing parameters for the machine are acquired using a novel computational intelligence software. TIG has many advantages over MIG, such as having a low heat input, clean beads, and the potential for both high-resolution prints as well as …

Role Of Eta Phase Evolution On Creep Properties Of Nickel Base Superalloys Used In Advanced Electric Power Generation Plants, Ninad Mohale

Dissertations, Master's Theses and Master's Reports

Advanced fossil energy power generation plants require materials that withstand high temperatures and corrosive environments. One such material that is used in steam turbines is Nimonic 263. It is a nickel-base superalloy that is principally strengthened by gamma primephase (Ni₃(Ti, Al)) and has an L1₂structure. At extended times and at turbine operating temperatures however, eta (Ni₃Ti) phase is known to form at the expense of gamma prime. Eta has a complex DO₂₄structure and is the stable phase between 750°C and 900°C, but with slow kinetics of formation. Little is understood about eta …

Estimating Red Wolf Ancestry In A Population Of Canids On Galveston Island, Texas, Tanner Barnes

Dissertations, Master's Theses and Master's Reports

Hybridization can be a conservation concern if genomic introgression leads to the loss of an endangered species’ unique genome, or when hybrid offspring are sterile or less fit then their parental species, but hybridization can also be an adaptive management tool if rare populations are severely inbred. One such species, the red wolf, is critically endangered in the United States, where all extant red wolves are descended from 14 founders which has contributed to an increase in inbreeding over time. Red wolves were considered extirpated from Texas in 1980, but before they disappeared, they hybridized with encroaching coyotes creating a …

Augmented Reality As A Tool For Industrial Heritage Education And Interpretations, Garand A. Spikberg

Dissertations, Master's Theses and Master's Reports

Combining Augmented Reality with spatially and temporally robust Historical Spatial Data Infrastructures may have the potential to provide users with interpretive and educational opportunities they otherwise would not have. Adapting research oriented historical GIS projects such as the Copper Country Historical Spatial Data Infrastructure to usage as interpretive material through the utilization of “off the shelf” augmented reality applications such as AuGeo has the potential to expand the utility and reach of that research data outside of the lab, while providing new interpretive opportunities by allowing users to see that data in its original spatial context and giving them the …

Online Retirement Planning Training: The Effects Of Usability On Cognitive Load And Retirement Planning Activity Levels, Natasha Hardy

Dissertations, Master's Theses and Master's Reports

The shift from defined benefit to defined contribution retirement plans for the current generation of retiree planners, Generation X, has placed the onus on individuals to gather, comprehend, and utilize complex financial information in order to plan their own retirement. Low savings rates and retirement planning activity indicate that individuals are not up to the challenge. This research investigates the interplay of three facets of cognitive load, usability, tech and retirement anxiety and the effects of a usability intervention on retirement planning activity levels.

Study 1 used semi-structured interviews and cognitive task analysis to explore themes of computer and retirement …

High Injection Pressure Impinging Diesel Spray Characteristics And Subsequent Soot Formation In Reacting Conditions, Zhihao Zhao

Dissertations, Master's Theses and Master's Reports

The spray impingement in diesel engines attracts the attention of engine researchers in recent decades as the physical size of the engine is reduced. Due to the spray impingement, the atomization, vaporizing and air-fuel mixing quality is altered compared to a free spray. For emission control, soot is one of the major particulate emissions from diesel combustion and its formation in an impinged spray is worthy to be investigated.

Firstly, to understand the impinged spray characteristics, the experiments for both non-vaporizing and reacting conditions were conducted in a constant volume combustion vessel. The impinged spray was captured by a high-speed …

Denitrification And Nitrogen Fixation Commonly Co-Occur But Rates Vary Throughout The Year And In Different Environments, Kevin Nevorski

Dissertations, Master's Theses and Master's Reports

Denitrification and nitrogen fixation are nitrogen cycling processes that can occur simultaneously in streams but are rarely studied together. The overarching goal of this dissertation was to quantify temporal and spatial variation of these processes in streams across the USA, characterize the environmental drivers of that variation, and determine the role that denitrification plays in the carbon cycle. To characterize temporal variation in these processes, a 2-year study in the Pilgrim River in Michigan’s Upper Peninsula found no difference in rates among seasons but high day-to-day variation in rates of both processes (maximum daily change 4,390 μg N/m²/hr …

Origin And Distribution Of Diffuse Soil Co2 Gas Emissions Across Turrialba And Irazú Volcanoes, Costa Rica, Katie Nelson

Dissertations, Master's Theses and Master's Reports

We characterized large-scale volatile emissions across the summit and flanks of the actively degassing Turrialba volcano, Costa Rica, using soil gas flux measurements and ¹³C isotopes. The objectives of this study were the following: 1) to monitor changes in the magmatic activity and identify source contributions over Turrialba using measurements of CO₂ soil gas emissions since the volcano last erupted in 2014-2015, and 2) to identify the location and extent of magma at depth, and the structures that allow gas transport to the surface. Degassing at the summit is concentrated along one normal fault lineament, the trace of …

Mapping Michigan's Historic Coastlines, Ryan A. Williams

Dissertations, Master's Theses and Master's Reports

This five-year project, sponsored by the Michigan Department of Environment, Great Lakes, and Energy, is working to map how Michigan’s Great Lakes shorelines have changed over the past 80+ years. Products of this project include publicly available digital, georeferenced, historic aerial photography datasets, as well as map layers depicting the locations of historic shorelines and bluff lines from 1938, 1980, 2009, 2016, 2018, and 2020. Additional products include bluff retreat risk areas, shoreline rate of change map layers, and tools to assist in the development of future Coastal Vulnerability Index projects for the Great Lakes. All products are available as …

The Effect Of Nutrition On Longevity And Fertility In Diverse Drosophila: A Tor-Mediated Process, Tessa E. Steenwinkel

Dissertations, Master's Theses and Master's Reports

Nutrition and growth are strongly linked, but not much is known about how nutrition leads to growth. To understand the connection between nutrition through diet, growth and/or proliferation, we need to study the phenotypes resulting from the activation and inhibition of central metabolic pathways. Here I use the model organism Drosophila melanogaster (D. mel.) and three non-model Drosophila species with different dietary needs, Drosophila guttifera (D. gut.), Drosophila deflecta (D. def.), and Drosophila tripunctata (D. tri.), to study the effects of dietary amino acid availability in these diverse flies on fecundity and …

Physicochemical Properties Of Atmospheric Aerosols And Their Effect On Ice Cloud Formation, Nurun Nahar Lata

Dissertations, Master's Theses and Master's Reports

Atmospheric aerosols play a vital role in the Earth's energy budget-directly by scattering and absorbing solar radiation and indirectly by acting as cloud condensation nuclei and ice-nucleating particles [1, 2]. The cloud formation potential of aerosol is driven by multiple factors, including surface properties, size distribution, composition, mixing state, phase state, and morphology [3]. The interaction of aerosols with clouds alters the aerosol's physicochemical properties. Those properties can also evolve during transport due to atmospheric processing, in turn, affect the aerosol's ice nucleation and cloud formation activities. This thesis presents experimental studies to understand the role of physicochemical properties of …

Cobalt, Molybdenum, And Nickel Complexes, Natural Zeolites, Epoxidation, And Free Radical Reactions, Nicholas K. Newberry

Dissertations, Master's Theses and Master's Reports

Chapter 2 is based on the synthesis and study of the compounds of the bidentate ligand ((5-phenyl-1H-pyrazol-3-yl)methyl)phosphine oxide with molybdenum and cobalt as the transition metal. The complexes were analyzed via FTIR, NMR, UV-Vis, Fluorescence Spectroscopy, TGA, DFT, and XRD. Chapter 3 resulted in the synthesis of the complexes [Ni(II)SSRRL](PF6)2 and [Ni(II)SRSRL](Cl)(PF6) of which [Ni(II)SRSRL](Cl)(PF6) had not been previously analyzed. Both products were analyzed via FTIR, NMR, UV-Vis, CV, DFT, and XRD. Chapter 5 contains the results of the characterization and modification of 4 natural zeolites (AZLB-Na, AZLB-Ca, NM-CA, NV-Na) from the United States in an attempt to increase the …

Efficient Modeling Of Random Sampling-Based Lru Cache, Junyao Yang

Dissertations, Master's Theses and Master's Reports

The Miss Ratio Curve (MRC) is an important metric and effective tool for caching system performance prediction and optimization. Since the Least Recently Used (LRU) replacement policy is the de facto policy for many existing caching systems, most previous studies on efficient MRC construction are predominantly focused on the LRU replacement policy. Recently, the random sampling-based replacement mechanism, as opposed to replacement relying on the rigid LRU data structure, gains more popularity due to its lightweight and flexibility. To approximate LRU, at replacement times, the system randomly selects K objects and replaces the least recently used object among the sample. …

Major Index Over Descent Distributions Of Standard Young Tableaux, Emily Anible

Dissertations, Master's Theses and Master's Reports

This thesis concerns the generating functions $f_{\lambda, k}(q)$ for standard Young tableaux of shape $\lambda$ with precisely $k$ descents, aiming to find closed formulas for a general form given by Kirillov and Reshetikhin in 1988. Throughout, we approach various methods by which further closed forms could be found. In Chapter 2 we give closed formulas for tableaux of any shape and minimal number of descents, which arise as principal specializations of Schur functions. We provide formulas for tableaux with three parts and one more than minimal number of descents, and demonstrate that the technique is extendable to any number of …

Lithium-Ion Battery Recycling Using Mineral Processing Methods, Ruiting Zhan

Dissertations, Master's Theses and Master's Reports

The surges in the volume of the retired Li-ion batteries (LIBs) in future motivate Li-ion battery recycling R&D activities worldwide. Within the Li-ion batteries, the most valuable component is cathode active materials that consist of critical minerals and materials such as lithium, cobalt, nickel, manganese. The LIB recycling has been investigated at both the lab scale and industrial scale. There are three existing recycling methods, namely physical separation, pyrometallurgy, and hydrometallurgy. Physical separation methods sort individual battery components without changing materials’ physical properties, while both pyrometallurgical and hydrometallurgical recycling routes aim to recover valuable metals using a high-temperature process and …