Digital Commons Network^™

Controls On Autotrophic Respiration, Heterotrophic Respiration, And Decomposition In Northern Forested Rivers, Renn Schipper

Dissertations, Master's Theses and Master's Reports

Autotrophic respiration (AR), heterotrophic respiration (HR), and decomposition are important contributors to the carbon cycle in streams. It is important to understand how different environmental factors, such as canopy cover and dissolved organic carbon (DOC), influence these processes. DOC concentrations in northern forested streams are increasing, which may affect light and carbon availability. To examine the effects of DOC and canopy cover on these processes we measured gross primary production, ecosystem respiration and decomposition at 8 sites in 4 streams in the Upper Peninsula of Michigan and used quantile regression to estimate AR and HR. Among sites, AR and decomposition …

Phase-Field Fracture Modeling For Interlocking Micro-Architectured Materials, Shubham Sinha

Dissertations, Master's Theses and Master's Reports

It is fascinating to see how natural materials like teeth enamel, bone and nacre possess a very high stiffness and strength in spite of the fact that they are composed of minerals mostly. Studies have shown the reason for this aberration as the presence of weaker interfaces with intricate interlocking architectures at microscopic levels in these materials. Inspired by the architecture of these materials, micro-architectured sutures with jig-saw like geometry is being studied in this research study. The main focus of this study is to examine the effects of friction co-efficient and interlocking angles of the jig-saw tabs on pullout …

Integration Of Robotic And Electro-Pneumatic Systems Using Advanced Control And Communication Schemes, Chinmay Kondekar

Dissertations, Master's Theses and Master's Reports

Modern industrial automation systems are designed by interconnecting various subsystems which work together to perform a process. The thesis project aims to integrate fragmented subsystems into a flexible and reconfigurable system through advanced communication protocols and perform a process to demonstrate the effectiveness of interconnected systems.

The system consists of three six-axis robots, one electro-pneumatic robot, and two conveyors connected using EthernetIP communication and hardwired connections. The interconnected system works together to perform machining of a workpiece using advanced control methods of CAD to robot path generation, central control through a PLC, and process control through HMI.

Standardized programming blocks …

Nonlinear Model Predictive Control Of Wave Energy Converter, Isha Malekar

Dissertations, Master's Theses and Master's Reports

In this report model predictive control (MPC) is applied to a simulated, spherical, point absorber wave energy converter to maximize energy extraction. Constraints are applied to the buoy's displacement and the power take-off (PTO) generator force. The WEC's "truth” model uses nonlinear Froude-Krylov (FK) hydrostatic and hydrodynamic forces. This is in contrast with previous studies where linear approximations are used in the form of a hydrostatic stiffness force and a wave excitation force. The nonlinear forces become significant when the vertical displacement of the buoy exceeds about 40% of the buoy's radius. Two versions of MPC are compared where optimal …

Torrefaction Of Mixed Solid Waste, Zhuo Xu

Dissertations, Master's Theses and Master's Reports

The world is witnessing unprecedented accumulation of solid wastes in the environment and landfills with well-documented ecological, environmental, health, and economic consequences. With population growth and rise in living standards, solid wastes generation will increase, making the issue more pressing. In addition, current practices of solid waste disposal are creating an immediate challenge and a long-term disaster-scale problem. The solid wastes comprises two main groups of materials: (i) fiber wastes (paper, food, wood, trimming, 61% of U.S. municipal solid waste) and (ii)uniquely challenging subset of plastic wastes (13%) that become a threat to global sustainability including dangers to marine and …

Blind Direct Walking Distance Judgment Research: A Best Practices Guide, Crystal Massoglia

Dissertations, Master's Theses and Master's Reports

Over the last 30 years, Virtual Reality (VR) research has shown that distance perception in VR is compressed as compared to the real world. The full reason for this is yet unknown. Though many experiments have been run to study the underlying reasons for this compression, often with similar procedures, the experimental details either show significant variation between experiments or go unreported. This makes it difficult to accurately repeat or compare experiments, as well as negatively impacts new researchers trying to learn and follow current best practices. In this paper, we present a review of past research and things that …

Using Text Mining And Machine Learning Classifiers To Analyze Stack Overflow, Taylor Morris

Dissertations, Master's Theses and Master's Reports

StackOverflow is an extensively used platform for programming questions. In this report, text mining and machine learning classifiers such as decision trees and Naive Bayes are used to evaluate whether a given question posted on StackOverflow will be closed or answered. While multiple models were used in the analysis, the performance for the models was no better than the majority classifier. Future work to develop better performing classifiers to understand why a question is closed or answered will require additional natural language processing or methods to address the imbalanced data.

Evaluating Household Food, Energy, And Water Environmentally Oriented Anti-Consumption In The Us: Toward A Comprehensive Theory Synthesis, Jacob Slattery

Dissertations, Master's Theses and Master's Reports

Introduction – Everyday household activities using food, energy, and water (FEW) resources consumed in the US have perpetually contributed a large amount of carbon emissions into the atmosphere, amplifying the effects of climate change globally. These actions are embedded and routinized effectively at the individual level, resulting in habits inert to changes in household FEW behaviors more friendly to socio-environmental impacts. Public and voluntary policies could help shift perceptions of FEW household conservation, but a gap in environmental political and psychological research reveals a deficit in evidence examining the antecedents of the moral or personal norm concept.

Objective – The …

Recommendations For A Community-Led Multi-Stakeholder Watershed Management Plan In Rural Panama, Tristan Odekirk

Dissertations, Master's Theses and Master's Reports

Valle Risco is a small, rapidly growing rural town in northwest Panama. As the town grows and develops those who live there have expressed concern at sustainably managing the surrounding watershed. This report consists of some considerations and suggestions for the community of Valle Risco as they build a strong town that plays a central role in the socioeconomic development of the region. This information is based on the experience of the author while he served the town with the U.S. Peace Corps. Recommendations include solutions for wastewater management, storm water drainage, consistent water quality monitoring, and the use of …

Carbon Capture And Utilization, Sriram Valluri

Dissertations, Master's Theses and Master's Reports

As the world moves towards clean energy initiative, carbon capture and utilization technologies are key to achieving net zero emissions. CO2 capture with amines has many disadvantages and cannot be applied to commercial power plants. The current manuscript will address this issue as well as a solution that involves the use of low-cost alkali absorbent CO₂ capture solutions, combined with an electrochemical regeneration method that uses the least amount of energy available for capture and regeneration. This research will also further address the issue of how to deal with the captured CO2. Several viable storage and utilization methods have …

Real Time Adaptive Relay Settings For Microgrid Protection Verified Using Hardware In Loop, Aadam Harnekar

Dissertations, Master's Theses and Master's Reports

Microgrids with penetration of renewables is imposing new challenges for system protection. Renewables are characterized with high source impedance which limit the short circuit current. The value of short-circuit current is limited due to converters used which limit the current to a maximum of 1.1 to 1.5 times maximum rated load current. This can result in faults during the islanded mode of microgrid to go unnoticed if the relay settings are not adapted to account for it. The presence of such uncleared faults in the microgrid can result in exposing it to overcurrent for a long time which can damage …

Evening And Overnight Cardiovascular And Arterial Stiffness Responses To Simulated Binge Drinking, Grant Thivierge

Dissertations, Master's Theses and Master's Reports

Acute alcohol consumption has been shown to increase blood pressure, while chronic heavy alcohol consumption is associated with the development of hypertension. Another factor that contributes to hypertension is arterial stiffness. While evidence suggests light to moderate alcohol consumption can decrease arterial stiffness, the impact of binge alcohol consumption on acute and overnight changes of arterial stiffness remains unknown. Twenty-seven participants (14 female; 13 male) received a binge alcohol dose or fluid control randomly one month apart. Alcohol or fluid control doses were administered in two equally divided allocates at 8 and 9 pm. A 1:3 mixture of 190 proof …

Understory Dynamics Across 62-Years Of A Northern Hardwood Management Gradient Study, Heidi Harmala

Dissertations, Master's Theses and Master's Reports

Northern hardwood selection silviculture relies on the perpetuation of natural regeneration. However, many researchers and forest managers have concerns about deficiencies in regeneration and the associated ingrowth and recruitment of advance regeneration under single-tree selection. Given the differences of management application in the Great Lakes region, long-term studies and datasets are critical to understanding of how these systems function and change. Using the Cutting Methods Study, in the Western Upper Peninsula of Michigan, these concerns were investigated with a multi-decadal dataset, for understory tree species composition and density, diversity, recruitment, and age-diameter relationships across management methods. In response to the …

Metagenomic Identification And Classification Of The Mercury-Methylating Gene Hgca In Response To Water Table And Plant Functional Group Manipulations In Peat Soil, Madeline Peterson

Dissertations, Master's Theses and Master's Reports

Methyl-mercury (MeHg) is a potent neurotoxin that threatens the health of humans and wildlife alike. Climate warming threatens to shift regional precipitation and climate regimes in peatland environments, which could destabilize northern peatlands and accelerate both Hg release from soil and MeHg production. Peatlands are among the leading hotspots for MeHg, yet little is known about the community composition or functional relationship of mercury-methylating microbes in response to varying environmental conditions. The recognized mercury-methylating genes responsible for this activity are the obligatory gene pair hgcA and hgcB. Metagenomic data from the full-factorial peatland mesocosm experiment PEATcosm was obtained to …

High-Resolution Molecular Characterization Of Complex Environmental Mixtures: Aquatic Dissolved Organic Matter And Wildfire-Influenced Aerosol, Amna Ijaz

Dissertations, Master's Theses and Master's Reports

The natural environment is replete with organic matter of varying complexities. Whether it is particulate material in the atmosphere, decades old organic matter trapped within glaciers, or biological debris flowing with rivers and streams, natural organic matter (NOM) is exquisitely complex. High-resolution mass spectrometry allows us to have a glimpse of the molecular composition of NOM and delineate the elemental compositions of thousands of chemical species that form it. In this dissertation, the overarching aim was to explore the molecular diversity of complex mixtures from two sources: Surface water and atmospheric organic aerosol. The first objective of this dissertation was …

An Overview Of Converting Kabul’S Traffic Circles And Rotaries To Modern Roundabouts, Mohammad Anas Taeb

Dissertations, Master's Theses and Master's Reports

Circular intersections, in the form of traffic circles and rotaries, were built around the world in the first half of the twentieth century. However, with the rise in traffic flow, regular traffic congestion and accidents forced authorities to look for alternative solutions and, in many cases, signalized intersections became the preferred alternative. In the 1960s, the UK introduced concept of modern roundabouts and a new set of priority rules for the circulating traffic. Since the inception of modern roundabouts, they have enhanced both operational and safety aspects at these locations, even when used to replace large traffic circles/rotaries, proving that …

The Perceptions, Practices, And Policies That Govern Food, Energy, And Water Consumption In The U.S. Suburban Home: “More Than My Fair Share”, William Lytle

Dissertations, Master's Theses and Master's Reports

This dissertation addresses household consumption by advancing understandings of complex material, social, and regulatory structures that have a bearing on the future of sustainable and resilient practices at the residential scale in the United States. Interviews with 44 households in the U.S. were conducted to learn about perceptions of food, energy, and water consumption. Chapters two, three, and four utilize grounded theory and theories of practice. This inquiry yielded insights into social dynamics of household consumption, how human and more-than-human actors influence each other’s consumption, and how infrastructure and social class are interrelated. Chapter five is a policy maker’s guidebook, …

The Extraction Of Waxes And Lipids From Sorghum Using Green And Renewable Solvents Followed By Conversion To Biofuels Using Gamma-Valerolactone Pretreatment, Marissa Gallmeyer

Dissertations, Master's Theses and Master's Reports

Plant matter contains waxes and lipids that can be extracted and used or sold as a value-added product prior to conversion of the remaining plant material to biofuels. Wax and lipid extraction of plant materials is currently performed using volatile, non-renewable hydrocarbons, primarily hexane, which is produced from fossil fuels and can pose a health and safety hazard. The purpose of this study is to compare the amount and characteristics of waxes extracted by hexane with those extracted using organic solvents that are less toxic and can be produced from renewable sources.

Sorghum samples were extracted separately with hexane, 2-methyltetrahydrofuran …

The Influence Of Decreased Ambient Lighting On Reactive Balance Mechanisms In Young Adults, Jessica Pitts

Dissertations, Master's Theses and Master's Reports

Introduction: Balance recovery/reactive balance prevents falls by restabilizing the center of mass (COM) when instability occurs. Dim lighting is a risk factor for falling, although limited research has examined how lighting conditions affect the ability to recover from losses of balance. The purpose of this thesis was to examine the effect of lighting conditions on reactive balance mechanisms. Methods: 20 young adults (23.3(4.4) y) completed forward lean-and-release perturbations in two lighting conditions: 1) Light: ~800 Lux; 2) Dark: 0 Lux. Optical motion capture and surface electromyography were used to quantify stepping/angular kinematics, COM control, and the timing, activation, and coordination …

Comparing Scoop3d And Gis-Tissa Models For Slope Stability Analysis In Idukki, Kerala, India, Stepan Pikul

Dissertations, Master's Theses and Master's Reports

Landslides are the most destructive hazard in the mountainous Idukki district in the State of Kerala, India. Therefore, evaluating the possible occurrence of landslides and analyzing the factors that trigger failure is an essential part of a reliable landslide assessment. Physics-based models are commonly used to determine potential landslide susceptible areas in terms of Factor of Safety (FS). Recent years have seen the use of physics-based methods for regional-scale landslide susceptibility analysis using geospatial tools. In this study, we compare two physics-based models using the same data from Idukki. The two models are the Geographic Information System-Tool for Infinite Slope …

Improving The Temporal Accuracy Of Turbulence Models And Resolving The Implementation Issues Of Fluid Flow Modeling, Kyle J. Schwiebert

Dissertations, Master's Theses and Master's Reports

A sizeable proportion of the work in this thesis focuses on a new turbulence model, dubbed ADC (the approximate deconvolution model with defect correction). The ADC is improved upon using spectral deferred correction, a means of constructing a higher order ODE solver. Since both the ADC and SDC are based on a predictor-corrector approach, SDC is incorporated with essentially no additional computational cost. We will show theoretically and using numerical tests that the new scheme is indeed higher order in time than the original, and that the benefits of defect correction, on which the ADC is based, are preserved.

The …

Deterministic And Statistical Methods For Inverse Problems With Partial Data, Yanfang Liu

Dissertations, Master's Theses and Master's Reports

Inverse problems with partial data have many applications in science and engineering. They are more challenging than the complete data cases since the lack of data increases ill-posedness and nonlinearity. The use of only deterministic or statistical methods might not provide satisfactory results. We propose to combine the deterministic and statistical methods to treat such inverse problems. The thesis is organized as follows.

In Chapter 1, we briefly introduce the inverse problems and their applications. The classical deterministic methods and Bayesian inversion are discussed. The chapter is concluded with a summary of contributions.

Chapter 2 considers the reconstruction of the …

Unmanned Ground Vehicle (Ugv) Docking, Connection, And Cabling For Electrical Power Transmission In Autonomous Mobile Microgrids, John Naglak

Dissertations, Master's Theses and Master's Reports

Autonomous Mobile Microgrids provide electrical power to loads in environments where humans either can not, or would prefer not to, perform the task of positioning and connecting the power grid equipment. The contributions of this work compose an architecture for electrical power transmission by Unmanned Ground Vehicles (UGV). Purpose-specific UGV docking and cable deployment software algorithms, and hardware for electrical connection and cable management, has been deployed on Clearpath Husky robots. Software development leverages Robot Operating System (ROS) tools for navigation and rendezvous of the autonomous UGV robots, with task-specific visual feedback controllers for docking validated in Monte-Carlo outdoor trials …

Short-Term Fasting And Autonomic Control, Joshua Gonzalez

Dissertations, Master's Theses and Master's Reports

Obesity is a chronic metabolic disorder associated with increased risk of cardiovascular disease. Evidence suggests that chronic intermittent fasting improves cardiometabolic health and reduces arterial blood pressure. However, the mechanisms underlying the reductions in blood pressure and improved cardiovascular health observed from chronic fasting studies remain unclear. The autonomic nervous system has a central role in the regulation of blood pressure and is essential for cardiovascular homeostasis. We conducted a study to investigate how acute fasting influences autonomic control of blood pressure at rest and during stress. Twenty-five young, healthy, normal weight, normotensive participants were tested twice, once in the …

Construction And Analysis Of Genetic Regulatory Networks With Rna-Seq Data From Arabidopsis Thaliana, Tessa Kriz

Dissertations, Master's Theses and Master's Reports

Reconstruction of gene regulatory networks (GRNs) is a fundamental aspect of genetic engineering and provides a deeper understanding of the biological processes of an organism. Two methods were implemented to reconstruct the gene regulatory networks of Arabidopsis thaliana under two treatments: methyl jasmonate (MeJa) and salicylic acid (SA). The Joint Reconstruction of multiple Gene Regulatory Networks (JRmGRN) method was utilized to construct a joint network for identifying hub genes common to both conditions in addition to networks specific to each condition. The Differential Network Analysis with False Discover Rate Control method constructed a network of connections unique to only one …

Elucidating Peatland Disturbance Ecology And Carbon Dynamics Through The Lens Of Soil Using Infrared Spectrometry, Dominic Uhelski

Dissertations, Master's Theses and Master's Reports

We sought to quantify the fire regimes of peatlands in the hemi-boreal zone of North America, and to understand the qualities of their peat. We used infrared spectrometry to accomplish both goals by gathering spectral information about the organic matter in each sample. We used a series of mixtures of natural peat and natural peat charcoal to isolate the spectral components associated with charcoal concentration. We built a multiple linear regression model which predicts the charcoal concentration in peat samples. We validated our data using nuclear magnetic resonance spectrometry. As a result, we can accurately predict the charcoal concentration of …

Anterior Cruciate Ligament Injury Incidence Across Sex, Sport, And Level: A Systematic Review And Meta-Analysis, Dana Anderson

Dissertations, Master's Theses and Master's Reports

Well controlled Anterior Cruciate Ligament (ACL) injury prevention neuromuscular training reduces the risk of ACL injury by 50%, but despite the efficacy of these programs, ACL injury rates have not decreased. This lack of decrease in injury incidence may be due in part to limited knowledge on who is most at risk for sustaining an ACL injury, and there is no formal clinical tool available to estimate the personalized or group risk of ACL injury. The purpose of this study was to better understand what groups of athletes are most at risk of sustaining a primary ACL injury, as the …

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 …

Base-Labile Protecting Groups For Stepwise Peg Synthesis, Logan D. Mikesell

Dissertations, Master's Theses and Master's Reports

Stepwise synthesis of monodisperse polyethylene glycols (PEGs) and their derivatives usually involves using an acid-labile protecting group such as DMTr and coupling two PEG moieties together under the basic Williamson ether formation conditions. Using this approach, each elongation of PEG is achieved in three steps – deprotection, deprotonation, and coupling – in two pots. Here, we report a more convenient approach for PEG synthesis featuring the use of a base-labile protecting group such as the phenethyl group. Using this approach, each elongation of PEG can be achieved in only two steps – deprotection and coupling – in one pot. The …

Local Watershed Analysis For Hubbell And Lake Linden, Michigan, Brittany Hubbard

Dissertations, Master's Theses and Master's Reports

This report analyzes flood frequency risk, examines drainage, and delineates local level watershed characteristics for the Site located in western HUC 12-040201 030304 Torch Lake Subwatershed. Specifically, unnamed catchments in need of HUC-14 or HUC-16 local level delineation are evaluated to determine the effects of excess runoff on the cities of Hubbell and Lake Linden, Michigan. Further, this report aims to identify the location of known or suspected historical and current drainage infrastructure, and to prioritize locations for low-impact sustainable designs that reduce excess runoff and provide flood protection for these lakeshore communities.