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Correlation Of And Development Of Procedure To Use A Resonant Plate With Mechanical Excitation For Shock Testing Small-To-Medium Size Spacecraft And Provide Aerospace Shock Analysis And Testing Guidelines, Monty Kennedy

Dissertations, Master's Theses and Master's Reports

In the aerospace industry it is known that performing shock analysis and testing on spacecraft is difficult to do mostly because shock loads create a very short duration shock wave transient that can have high acceleration peak levels (1,000-5,000 g) and wide frequency content (100-10,000 Hz). FE (finite-element) shock analysis is difficult because implicit linear FE software commonly used for most vibration analysis in aerospace does not account for shock wave propagation, reflection, and attenuation that occurs based upon the distance from the shock source at the base of the spacecraft and the attenuations that occurs through mechanical joints. Spacecraft …

Dissecting The Role Of Selenoprotein P And Thioredoxin Reductase In Pancreatic Cancer Metabolism, Alyssa A. Abbas

Dissertations, Master's Theses and Master's Reports

Pancreatic ductal adenocarcinoma (PDAC), the fourth leading cause of US cancer-related deaths, has a stark 5-year survival rate of 9%, emphasizing an urgent need for effective therapies. A well-established characteristic of cancer, metabolic dysregulation, presents an opportunity for developing therapies that target specific metabolic susceptibilities inherent in cancer cells. Our recent studies have discovered a susceptibility in PDAC; deprivation of cystine or blocking its uptake by erastin (a cystine transport inhibitor) triggers significant lipid peroxidation, thereby inducing ferroptosis specifically in the mesenchymal subtype of PDAC, but not in the epithelial subtype. This study aims to elucidate the roles of Selenoprotein …

Effect Of Sc On Recrystallization Resistance Of Aa7050, Keaton Schmidt

Dissertations, Master's Theses and Master's Reports

The extrusion process involves high temperatures and strains that can result in undesirable microstructures, especially along the surface. Extruded alloys tend to exhibit surface recrystallization during heat treating at regions of higher strains, which can lead to reduced fatigue strength and corrosion resistance. By adding Sc to AA7050, nano-sized dispersoids are formed with Sc cores and Zr shells that restrict recrystallization more than the base alloy that only utilizes Zr. Billets with varying Sc content and a control with only Zr were cast, and extrusions were made in order to compare surface microstructures at varying strains in the as-extruded and …

Stamp Sand Along The Keweenaw Shoreline: Solid And Dissolved Copper & Effects On Biota, Gary Swain

Dissertations, Master's Theses and Master's Reports

Stamps sand refers to the regional colloquialism for the mine-tailing byproducts generated from copper (Cu) ore processing mills located in Michigan’s Keweenaw Peninsula. In the Keweenaw region, copper extracted from basalt ores resulted in a legacy of 100’s of millions of metric tonnes of stamp sand wastes, including 22.7 million metric tonnes at Gay, MI. Trace amounts of Cu persist in stamp sands and when leached have toxic enough concentrations to influence aquatic biota. To better understand stamp sands’ properties, we ran experiments and compiled data about the solid and dissolved phases of Cu. Solid phase concentration of Cu was …

Quantifying The Impact Of Wide Base Tires On Pavement Performance In Michigan, Lei Yin

Dissertations, Master's Theses and Master's Reports

This study aimed to investigate the use of wide base tires (WBT) in Michigan to quantify the effect of different percentages of WBT loads on flexible and rigid pavements. Surveys and field investigations were conducted to quantify the WBT usage in Michigan. The JULEA (for flexible pavements) and Illislab (for JPCP) software programs were used to calculate the mechanical response between dual tire (DT) and WBT loads, while the Mechanical-Empirical (ME) pavement design process was utilized for damage accumulation and pavement distress analysis. Investigation results rationalized the assumption of WBT proportion for design purposes as 10% currently and up to …

Under Ice Photosynthetic Primary Production And Dark Carbon Fixation In A Temperate Freshwater System, Vanessa Cubillos Tellez

Dissertations, Master's Theses and Master's Reports

Ice-covered lakes are vulnerable to environmental change, especially those in the Northern Hemisphere where ice cover is rapidly declining due to global warming. These changes can alter metabolic processes and disrupt carbon cycling driven by primary producers who form the base of the food chain and are key to sustaining ecosystem function. Photosynthetic primary production and dark carbon fixation under the ice in the Keweenaw Waterway, a temperate freshwater system that is ice-covered for ~3 months out of the year, were studied using a carbon isotopic labeling (14C-bicarbonate) technique. Water samples were collected weekly during ice cover and monthly during …

Study Of Droplets Interactions On Solid Surface For Manufacturing Applications, Menghan Zhao

Dissertations, Master's Theses and Master's Reports

Droplet impact behaviors on a solid substrate is a complicated process that involves multiple phenomena on a small scale within a short time. This phenomenon has wide applications in the industrial, medical, and scientific fields. To understand the complicated mechanism, we select the oscillation process as the marked phase to observe and analyze the dynamical balancing between different forces and conservation of energies and compare it to the typical damped harmonic oscillator (DHO) model to examine the character of variables as viscosity, surface tension, and wettability. From the testing results, we created a precise model for post-impact dynamics and described …

Stability Of Linicoal-Oxide Electrode Material Under High-Temperature Ceramic Fuel Cell Conditions, Wei Zhang

Dissertations, Master's Theses and Master's Reports

LiNi0.8Co0.15Al0.05O2 (LNCA) is an important cathode material for room-temperature operation of lithium-ion batteries (LIBs). As an emerging research area, LNCA was recently applied as electrodes (both cathode and anode) for high-temperature ceramic fuel cells (CFCs) with impressive performances. However, the stability of LNCA electrode material under CFC operating conditions (i.e., reactive atmospheres and high temperatures) remains unknown. In this dissertation: (1) The stability of LNCA in air and H2 atmospheres was systematically evaluated at elevated temperatures (i.e., the operating electrode environments of H2-fueled CFCs). It was found that LNCA exhibited excellent stability in air within a wide temperature range from …

Joint Probability Analysis Of Extreme Precipitation And Water Level For Chicago, Illinois, Anna Li Holey

Dissertations, Master's Theses and Master's Reports

A compound flooding event occurs when there is a combination of two or more extreme factors that happen simultaneously or in quick succession and can lead to flooding. In the Great Lakes region, it is common for a compound flooding event to occur with a high lake water level and heavy rainfall. With the potential of increasing water levels and an increase in precipitation under climate change, the Great Lakes coastal regions could be at risk for more frequent and severe flooding. The City of Chicago which is located on Lake Michigan has a high population and dense infrastructure and …

Optimizing The Extrudability Of 6082 Aluminum By Varying The Magnesium And Silicon Concentration, Eli A. Harma

Dissertations, Master's Theses and Master's Reports

Alloy 6082 aluminum is used for high-volume manufacturing in the automotive industry due to its high strength, impact performance, and corrosion resistance. However, given these improved properties, the alloy has decreased formability compared to other 6xxx series alloys, especially in the extrusion process. Controlling the dynamic recovery and recrystallization properties by changing the additions of Mg and Si can improve the hot deformation properties. Five alloys of varying Mg and Si concentrations between 0.6 to 1.2wt% Mg and 0.7 to 1.3wt% Si were made with constant concentrations of Cr, Fe, and Mn and the same homogenization heat treatment. The proposed …

Exercise Is Medicine® On Campus: A National Analysis And Assessment Of Community Impact, Isaac M. Lennox

Dissertations, Master's Theses and Master's Reports

Introduction: The American College of Sports Medicine (ACSM) founded the Exercise is Medicine® on Campus (EIM-OC) initiative, which calls upon colleges and universities to promote physical activity on their campuses. The distribution of EIM-OC programs across the U.S. has not been reported. In addition, the impact that EIM-OC programs have on community-level physical activity prevalence is unknown. The purpose of my thesis was to evaluate and enhance the EIM-OC initiative to promote physical activity and overall health in the U.S. Methods: Recognized EIM-OC programs in the U.S. (n=131) were described based on local, county, state, and regional-level variables. Local variables …

Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad

Dissertations, Master's Theses and Master's Reports

There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …

Capturing Microstructural Heterogeneity And Predicting Local Transport Phenomena In Pemfc Catalyst Layers: A Comprehensive Network Modeling Approach, Shahriar Alam

Dissertations, Master's Theses and Master's Reports

A unique network architecture that captures the microstructural heterogeneity and predicts the local transport properties of PEMFC catalyst layers is proposed. Separate networks containing numerous cylindrical elements and nodes are generated that represent the solid and pore phase of the catalyst layer. Transport resistances are assigned to the elements while the nodes are volumeless. The networks are interlinked through nodes where local properties are stored. The generated computational grid's macroscopic behaviors (percolation behavior, gas diffusivity, and ion conductivity) will be matched against the experimental data for validation. Diffusion-like transport equations are applied to the networks that provide local water balance, …

On The Gaussian-Core Vortex Lattice Model For The Analysis Of Wind Farm Flow Dynamics, Apurva Baruah

Dissertations, Master's Theses and Master's Reports

Wind power science has seen tremendous development and growth over the last 40 years. Advancements in design, manufacturing, installation, and operation of wind turbines have enabled the commercial deployment of wind power generation systems. These have been due, in a large part, to the expertise in the simulation and modeling of individual wind turbines. The new generation of wind energy systems calls for a need to accurately predict and model the entire wind farm, and not just individual turbines. The commercial deployment of these wind farms depends on model's ability to accurately capture the different physics involved, each at its …

An Active Voice Coil Negative Stiffness Vibration Isolator With Application To Mobile 3d Printing, Lucas M. Schloemp

Dissertations, Master's Theses and Master's Reports

Equipment whose performance degrades when exposed to base vibration is often deployed in vibration-rich environments. Using 3D printers in mobile applications, such as vehicles and ships, are typical examples where the extruder and bedplate are easily excited by base vibration. A versatile active vibration isolator is considered in this thesis constructed using a voice coil actuator and a laser displacement feedback sensor to achieve a wide range of dynamic response characteristics, including negative stiffness. This approach permits transmissibility shaping to meet band-limited base isolation requirements without active damping vibration control. A combination of simulation and hardware validation is used to …

Programming The Bistable Dynamic Vibration Absorbers Of A 1d-Metastructure For Adaptive Broadband Vibration Absorption, Shantanu H. Chavan

Dissertations, Master's Theses and Master's Reports

This research addresses a critical challenge in structural engineering—achieving comprehensive vibration control and energy dissipation in meta-structures. Departing from the limitations of passive structures with fixed bandgaps, we propose an innovative approach utilizing active meta-structures capable of dynamically tuning their bandgaps. The primary goal is to introduce an efficient method for programming meta-structures with multiple variable bandgaps, thereby enabling effective vibration attenuation across a broad frequency spectrum.

The methodology involves transforming passive resonators into bistable adaptable Dynamic Vibration Regulators (DVRs) through a sophisticated switching mechanism. This adaptation sets the stage for numerous unique combinations by independently switching each resonator. A …

Invasive Buckthorn Mapping: A Uav-Based Approach Utilizing Machine Learning, Gis, And Remote Sensing Techniques In The Upper Peninsula Of Michigan, Vikranth Madeppa

Dissertations, Master's Theses and Master's Reports

An Invasive species is a species that is alien or non-native to the ecosystem which causes harm to economic, environmental, or human health (E.O. 13112 of Feb 3, 1999). Invasive species have posed a serious threat to ecosystems across the globe. These invasive species have impacts on the biodiversity and productivity of invaded forests. Remotely sensed data is a valuable resource for understanding and addressing issues related to invasive species. This study presents a novel approach for mapping the distribution of two invasive plant species, Common and Glossy Buckthorn, using unmanned aerial vehicles (UAVs), machine learning algorithms, geographic information systems …

Alternative Method For Low Frequency Impact Sound Measurement For Building Field Tests, Sunit Girdhar

Dissertations, Master's Theses and Master's Reports

What do high heels, dog nails, and dragging furniture have in common? They are all frequent sources of noise pollution and annoyance in multi-story buildings. Building codes exist to control and mitigate such noise, but these codes are outdated and fail to protect the residents against noise annoyance. Footstep noise is still the number one cause of complaints among the residents. The impact performance of floor-ceiling assemblies is characterized using a single-number rating called the Impact Sound Rating (ISR). A standard tapping machine is used in pre-defined locations on the floor and the radiated Sound Pressure Level (SPL) is measured …

Structural Analysis And Interpretation Of Deformation Along The Keweenaw Fault System From Lake Linden To Mohawk, Michigan, Nolan G. Gamet

Dissertations, Master's Theses and Master's Reports

The Keweenaw fault is likely the most significant and most studied fault associated with the Midcontinent Rift System. The fault roughly bisects the Keweenaw Peninsula and places Portage Lake Volcanics (~1.1 Ga) over much younger Jacobsville Sandstone (~1.0 Ga). Published bedrock geology maps with cross sections from the 1950s show the fault as a single continuous trace that is locally associated with smaller cross faults and splays. The accompanying cross-sections show hanging-wall volcanic strata having a well-defined, listric geometry with dip decreasing away from the fault to the northwest.

This M.S. thesis presents a structural analysis and interpretation of the …

Uhplc/Ft-Ms Non-Targeted Screening Approach For Biomass Burning Organic Aerosol And Liquid Smoke As Biomass Burning Organic Aerosol Surrogate, D.M.R. Thusitha Dinusha Kumarihami Divisekara

Dissertations, Master's Theses and Master's Reports

Biomass combustion contributes a large amount of aerosol particles to the atmosphere impacting the climate system and human health. Identifying the molecular composition of biomass burning organic aerosol (BBOA) is challenging because of its complex nature. Liquid chromatography mass spectrometric non-targeted screening (NTS) methods provide a comprehensive analysis. However, the instrumentation and data analysis are challenging due to the extreme complexity of environmental samples. In the first part of this study, we implemented a new LC/FT-MS data processing approach by combining existing open-source data processing tools, MZmine2.53 and MFAssignR. The method's validity was checked using the standard polyacrylic acid (PAA) …

Supporting Team Innovation With Design Thinking Cognitive Strategies, Lisa M. Casper

Dissertations, Master's Theses and Master's Reports

Innovation is a 21st-century skill needed to design new systems, solve challenging problems, and develop novel solutions. Design Thinking (DT) is a tool used to support team innovation. In this experiment, 145 students (47 teams) used one of two DT methods during a semester-long project to come up with an innovative solution to one of the UNESCO 17 sustainable development goals. The key experimental manipulation was during the DT Ideate phase where teams brainstormed potential solutions. Teams either used a baseline DT Ideate strategy or an expanded one with additional prompts during a 10-minute period. Results indicated that teams using …

Molecular Dynamics Modeling Of Polymers For Aerospace Composites, Swapnil Sambhaji Bamane

Dissertations, Master's Theses and Master's Reports

Polymer matrix composite materials are widely used as structural materials in aerospace and aeronautical vehicles. Resin/reinforcement wetting and the effect of polymerization on the thermo-mechanical properties of the resin are key parameters in the manufacturing of aerospace composite materials. Determining the contact angle between combinations of liquid resin and reinforcement surfaces is a common method for quantifying wettability. It is challenging to determine contact angle values experimentally of high-performance resins on CNT materials such as CNT, graphene, bundles or yarns, and BNNT surfaces. It is also experimentally difficult to determine the effect of polymerization reaction on material properties of a …

Predicting The Reactivities And Reaction Mechanisms Of Photochemically Produced Reactive Intermediates, Benjamin Barrios Cerda

Dissertations, Master's Theses and Master's Reports

Photochemically produced reactive intermediates (PPRIs) such as the hydroxyl radical, carbonate radical (CO₃^•-) singlet oxygen (¹O₂) and triplet state of chromophoric dissolved organic matter (³CDOM^*) are formed in sunlit natural waters upon photoexcitation of chromophoric dissolved organic matter (CDOM). PPRIs react with the organic compounds involved in key environmental processes, resulting in transformation products of smaller molecular weight than their parent compounds. Photochemical transformation of these key water constituents due to their reactions with PPRIs may pose potential effects on human and aquatic ecosystems. Consequently, there is a need …

Altering The Environment: The Effects Of Light And Music On Vigilance Performance And Affective State, Lauren Sprague

Dissertations, Master's Theses and Master's Reports

Vigilance, otherwise known as a state of alert watchfulness, is a phenomenon that occurs when someone is sustaining their attention on a particular task or environment. Largely, tasks that require a state of vigilance induce negative mood outcomes, result in loss of performance over time, and cause increased disengagement from the task. These tasks involve detecting critical signals which are buried among more frequently occurring neutral signals. While little can be done to change the base nature of the vigilance task, altering the physical environment of the operator may improve working conditions to a point where there are fewer losses …

Impacts Of Introduced Earthworms On Sugar Maple Sap Chemistry And The Discourse Of Invasion Ecology, Shelby Nicole Lane-Clark

Dissertations, Master's Theses and Master's Reports

To delve into further understanding of the relationships between introduced earthworms, forest ecosystems, and the human systems they impact, two approaches were taken. In the first approach, we seek to explore ways we can shift the discourse within and regarding the field of invasion ecology by re-framing how we approach discussion, management, and education regarding introduced species. Language issues surrounding introduced species through the example of earthworms in North America are described and potential solutions are provided, including a repositioned perspective that may facilitate better relationships with the natural world. The goal is to shift the language to be more …

The Hidden Role Of The “Co-” Paradigm In The Conceptualization And Application Of Living Labs, Madelina E. Dilisi

Dissertations, Master's Theses and Master's Reports

In the past two decades, the living lab has emerged as an innovative approach for addressing a wide range of issues. Living labs challenge traditional top-down research and development approaches in an array of subjects including climate change and sustainability, healthcare, information communication technology, and urban planning. Despite their growth, the current conceptualization of living labs is incomplete. The conceptual ambiguity surrounding living labs prevents researchers and practitioners from appreciating their true value, limitations, and appropriate applications. My thesis builds on Dekker et al.’s (2020) living lab research by including key concepts from the “co” paradigm literature that includes the …

A Case Study On The Practice Of Carbon Offset Projects In Michigan: Forest Practitioners’ Perspectives, Zachary B. Hough Solomon

Dissertations, Master's Theses and Master's Reports

This report examines the practice of carbon offset programs on private nonindustrial forestlands in the state of Michigan ass. Previously, the state of Michigan provided technical assistance for enrollment in carbon offsets through the Michigan Working Forest Carbon Offset Program, but this program has now been discontinued. Currently, private companies and nongovernmental organizations are developing projects throughout the state with nonindustrial private landowners. This descriptive analysis in this case study examines the roles of different forest practitioners who are working on carbon offsets, including private consulting foresters and foresters within Michigan public agencies. I review the academic and grey literature …

Neuromorphic Computing Applications In Robotics, Noah Zins

Dissertations, Master's Theses and Master's Reports

Deep learning achieves remarkable success through training using massively labeled datasets. However, the high demands on the datasets impede the feasibility of deep learning in edge computing scenarios and suffer from the data scarcity issue. Rather than relying on labeled data, animals learn by interacting with their surroundings and memorizing the relationships between events and objects. This learning paradigm is referred to as associative learning. The successful implementation of associative learning imitates self-learning schemes analogous to animals which resolve the challenges of deep learning. Current state-of-the-art implementations of associative memory are limited to simulations with small-scale and offline paradigms. Thus, …

Novel Approaches To Compute Manifold Operators With The Radial Basis Functions Method, Jacob James Blazejewski

Dissertations, Master's Theses and Master's Reports

The bulk of this dissertation is mainly composed of four chapters, which are organized as follows: Chapter 1 provides an introduction to the Radial Basis Functions (RBF) method by briefly outlining its historical developments and reviewing the RBF interpolation and the RBF-Finite Difference (FD) methodologies, and their advantages/disadvantages. Chapter 2 describes the Orthogonal Gradients (OGr) method and the Fast OGr method and how these can be used to compute differential operators restricted to hypersurfaces and space curves ($\Gamma$) embedded in R3. We will highlight a challenge of pairing Fast OGr with RBF-FD on nearly flat local clusters and how to …

Physical Activity And Exercise With Blood Flow Restriction As Medicine During The Covid-19 Pandemic And Beyond, Isaac J. Wedig

Dissertations, Master's Theses and Master's Reports

During the COVID-19 pandemic, physical activity levels have decreased and sitting time has increased. This is a major concern as physical inactivity increases the risk for severe COVID-19 outcomes. Evidence also indicates that COVID-19 survivors can experience reduced physical function (i.e., ability to complete daily living activities) long after acute illness. Currently, there are no evidence-based guidelines for recovering physical function following COVID-19 infection. Exercise with blood flow restriction (BFR) presents a promising rehabilitation strategy as the benefits of traditional exercise can be achieved using lower intensities. However, several barriers such as cost, access to equipment, and lack of standardized …