Digital Commons Network^™

Optical And Single Particle Properties Of North Atlantic Free Tropospheric Aerosols And Implications For Aerosol Direct Radiative Forcing, Megan Morgenstern

Dissertations, Master's Theses and Master's Reports

Human-induced climate change has steadily become a reality rather than a possibility. One factor that plays into climate change is radiative forcing due to aerosol-radiation interactions (ARI). As such, it is important to understand how aerosols (atmospheric particles) interact with solar radiation. This work looks at seven samples of well-aged aerosols (aerosols traveling in the atmosphere for at least a few days) collected at Pico Mountain Observatory in the summer of 2015. Pico Mountain Observatory is located in a remote, high elevation site in the Azores, in the Eastern-North Atlantic Ocean. The goals of the study were to analyze the …

Development And Validation Of A Force Measuring Device For A Laboratory Wave Tank, Jacob K. Colling

Dissertations, Master's Theses and Master's Reports

The ability to predict the hydrodynamic force exerted on floating bodies plays a critical role in creating more effective control strategies for wave energy converters (WECs). Developing a test apparatus capable of directly measuring the forces exerted on a floating body subjected to a wavefield provides the means to validate theoretical prediction methods with experimental results and to develop data-based prediction methods for hydrodynamic forces. This report will discuss the development and validation of a device that measures the total vertical force exerted on a test artifact. The device requirements and design are discussed to examine the factors taken into …

Development And Implementation Of Robot Operating Systems For Undergraduates, Chelsey Spitzner

Dissertations, Master's Theses and Master's Reports

The purpose of this project was to create an undergraduate junior lab to teach students about Robotic Operating System (ROS). The labs were designed to highlight the usefulness of ROS and the process used. Designing algorithms, how to send/receive messages, and the hierarchy of how nodes work with each other are emphasized. Taking packages that are open-source then modifying them is also emphasized. This is done so that students can transfer their knowledge from this course to other robot operating systems.

Salt Water Intrusion In Water Distribution Systems: Analysis, Solution, And Eco-Efficiency, Darud E Sheefa

Dissertations, Master's Theses and Master's Reports

Since many water distribution systems (WDSs) experience saltwater intrusion, system behavior during saltwater intrusion is important. An alternative to the currently accepted WDS decontamination method of hydrant flushing is needed since during the current procedure all contaminated water is discharged to the surroundings which imposes environmental impacts. Hence, this research was conducted to study salt spread in different WDSs and to seek an alternative to hydrant flushing as a way of WDS decontamination. First, salt contamination was modelled in real water system models to document the salt spread. It was found that (1) if salt enters as a short pulse, …

Common Garden Study Reveals Frost-Tolerant, Generalist Northern Seed Sources Are Best Suited To Expand Range Of Quercus Rubra, Emily Lindback

Dissertations, Master's Theses and Master's Reports

Climate change is shifting the potential suitable range of northern red oak (Quercus rubra L.) faster than it can migrate, creating an adaptation lag. Quercus rubra is prominent in eastern North American forests and important for its carbon sequestration, ecological roles, and economic significance. Our study addresses which populations of Q. rubra are best suited for climatic conditions at the northern and central range limits. Our findings can inform forestry management policies such as assisted migration, where species are transferred within their native range to mitigate the effects of climate change. We planted over 800 Q. rubra seedlings …

Oxidative Aging And Fracture Behavior Of Polymers And Composites: Theory, Modeling And Experiments, Shabnam Konica

Dissertations, Master's Theses and Master's Reports

Polymers and their composites (PMC) have emerged as effective alternative materials in structural, aerospace, and automotive industries due to their lightweight and tunable properties compared to metals. However, these materials tend to degrade during their operations in extreme environments. In this work, two extreme conditions are considered: - i) high-temperature oxidative degradation of polymers and polymer-based composites ii) Fracture and damage of polymer-based composites under thermo-mechanical loading.

Polymer oxidation starts when oxygen from the ambient diffuses into the bulk material and initiates chemical reactions to develop a coarse, brittle oxide layer on the exposed surface. The oxidative degradation process is …

Reverse Cationic Flotation Of Hematite, Natalia Parra Alvarez

Dissertations, Master's Theses and Master's Reports

The reverse cationic flotation of hematite is the most common method to process hematite ores. The goal of this research is to understand the impact of fundamental water and surface effects to enable the optimization of the flotation process. At present, reverse cationic flotation is performed using a single chemical as both collector and frother. Excessive amounts of frother or collector should lead to diminished performance. This research investigates this phenomenon by replacing some of the collector with frothers. It was found that flotation recovery can be improved up to 2.5wt% via 10% replacement with methyl isobutyl carbinol (MIBC). Since …

Off Road Autonomous Vehicle Modeling And Repeatability Using Real World Telemetry Via Simulation, Matthew Paul Spencer

Dissertations, Master's Theses and Master's Reports

One approach to autonomous control of high mobility ground vehicle platforms operating on challenging terrain is with the use of predictive simulation. Using a simulated or virtual world, an autonomous system can optimize use of its control systems by predicting interaction between the vehicle and ground as well as the vehicle actuator state. Such a simulation allows the platform to assess multiple possible scenarios before attempting to execute a path. Physically realistic simulations covering all of these domains are currently computationally expensive, and are unable to provide fast execution times when assessing each individual scenario due to the use of …

Assessing The Validity Of An Online Assessment Of Motor Learning, Alexandra Watral

Dissertations, Master's Theses and Master's Reports

To understand motor learning we must observe improvements in the performance of a motor behavior over time. Current laboratory approaches to measuring motor learning are not accessible to all populations, and this lack of accessibility limits the ability of researchers to gain information about developmental processes and medical conditions that impact motor control. To date, there are a handful of portable motor learning tools that use devices such as smartphones and tablets but very few fully remote options. We have created a web-based application to assess visuomotor adaptation, a gold standard approach to studying motor learning, in a remote setting. …

Non-Chromatographic Oligonucleotide Purification And Automated Polyethyleneglycol Synthesis, Dhananjani N. A. M. Eriyagama

Dissertations, Master's Theses and Master's Reports

Synthetic oligodeoxynucleotides (ODN) have various applications in many areas such as, synthetic biology, chemical biology, antisense drug development, and data storage. As a result, there is a high demand for synthetic ODNs. Many advances have been made with ODN synthesis the purification still remains a bottleneck. The non-chromatographic purification method is developed to address this problem. Similarly, polyethylene glycols (PEGs) have been used in many areas including pharmaceutical applications, surface science, and nanomedicine due to its unique properties. However, monodispersed PEG synthesis is expensive with existing methods. A novel automated solid phase synthesis method is developed to obtain monodispersed PEGs. …

Model Predictive Control Of Energy Systems For Heat And Power Applications, Chethan Ramakrishna Reddy

Dissertations, Master's Theses and Master's Reports

Building and transportation sectors together account for two-thirds of the total energy consumption in the US. There is a need to make these energy systems (i.e., buildings and vehicles) more energy efficient. One way to make grid-connected buildings more energy efficient is to integrate the heating, ventilation and air conditioning (HVAC) system of the building with a micro-scale concentrated solar power (MicroCSP) sys- tem. Additionally, one way to make vehicles driven by internal combustion engine (ICE) more energy efficient is by integrating the ICE with a waste heat recovery (WHR) system. But, both the resulting energy systems need a smart …

Passivity-Based Numerical Modeling And Grid Integration Strategies For Wave Energy Converter Arrays, Salman Husain

Dissertations, Master's Theses and Master's Reports

The body of work presented here develops numerical time-domain models of Wave Energy Converter (WEC) arrays or wave farms. It will be shown here that a cluster of WECs can be more effective in extracting oceanic energy, can facilitate deployment logistics, and help with grid integration. The objectives of this work are: (i) developing a theoretical metric to evaluate the energy extraction potential of a WEC array, (ii) developing an algorithm that ensures the stability of the time-domain models of WEC arrays, and (iii) identifying strategies that facilitate grid integration and power management of a WEC array. In the process …

An Experimental Study On The Impact Of Water Injection On The Performance And Emissions Of A Natural Gas – Diesel Pilot Engine, Nic Tuma

Dissertations, Master's Theses and Master's Reports

Natural gas has been gaining popularity as an alternative fuel due to its high availability, low CO2 emissions, and low cost. In this experimental study, water injection’s impact on medium and heavy-duty engine operation fueled by natural gas and pilot diesel injection for ignition was studied under stochiometric operation for use with a three-way catalytic converter to meet criteria emissions for off-road power generation. To retain high efficiencies, a high compression ratio of 17.3:1 was used. Maintaining stoichiometric operation with a high compression ratio leads to combustion knock, pre-ignition, and high NOx formation. Conventionally, cooled EGR can be used to …

Intelligent Techniques To Accelerate Everyday Text Communication, Jiban Krishna Adhikary

Dissertations, Master's Theses and Master's Reports

People with some form of speech- or motor-impairments usually use a high-tech augmentative and alternative communication (AAC) device to communicate with other people in writing or in face-to-face conversations. Their text entry rate on these devices is slow due to their motor abilities. Making good letter or word predictions can help accelerate the communication of such users. In this dissertation, we investigated several approaches to accelerate input for AAC users. First, considering that an AAC user is participating in a face-to-face conversation, we investigated whether performing speech recognition on the speaking-side can improve next word predictions. We compared the accuracy …

Virtual Machine Introspection Tool Design Analysis, Justin Martin

Dissertations, Master's Theses and Master's Reports

Virtual machines are an integral part of today’s computing world. Their use is widespread and applicable in many different computing fields. With virtual machines, the ability to introspect and monitor is often overlooked or left unimplemented. Introspection is used to gather information about the state of virtual machines as they operate. Without introspection, verbose log data and state information is unavailable after unexpected errors or crashes occur. With introspection, this data can be analyzed further to determine the true cause of the unexpected crash or error. Therefore, introspection plays a critical role in portraying accurate historical information regarding the operating …

The Decline Of Lake Superior's Woodland Caribou: A Historical Gis Analysis, Jordan W. Kelley

Dissertations, Master's Theses and Master's Reports

Lake Superior’s woodland caribou have been declining since the early 1800s. This thesis asks: why? We hypothesize that as settlers expanded into the region, industrial development in woodland caribou habitat reduced woodland caribou persistence. Using an Historical Geospatial Information System (HGIS) analysis, we find that historical mining and railroad infrastructure are associated with woodland caribou extirpation, while wetlands and protected areas are associated with caribou persistence. We also conducted a stakeholder synthesis of the region to help understand diverse perspectives within and between advocacy coalitions that take different positions on the most effective caribou restoration policies. Beliefs on recovery options …

Properties And Environmental Impacts Of Sustainable Electrically Conductive Composites Of Carbonized Pulp Fibers And Recycled Polyamide 12, Chinmoyee Das

Dissertations, Master's Theses and Master's Reports

Electrically conductive composites are polymer composites filled with electrically conductive filler. Electrically conductive composites can be implemented in the development of lightweight electrically conductive components for the automotive industry. Traditional electrically conductive composites incorporate synthetic carbon-based fillers that have good properties but are very expensive and highly energy intensive, creating the need for a sustainable and cost-effective replacement. This study explores the effectiveness of biocarbon fibers developed from Douglas fir pulp fibers as a potential electrically conductive filler in recycled polyamide (PA) 12 composites.

Biocarbon fibers were developed from pulp by carbonization of the feedstock at 1000° C in an …

Rhetoric Of Surrogacy: Re-Considering Agency Through Embodied Performance, Ann Kitalong-Will

Dissertations, Master's Theses and Master's Reports

Surrogacy as a medical practice goes back, in a practical sense, to 1988, when the court case, “In the Matter of Baby M, A Pseudonym for an Actual Person,” was tried in the Supreme Court of New Jersey. At the heart of the issue, was the question of who Baby M’s legally-recognized mother was in the relationship between the contracting parents and the woman who gestated and gave birth to Baby M. Using this case as a jumping off point, this dissertation traces a history of surrogacy as a global industry. This project explores rhetorical agency in the embodied performance …

Word Games For Education: Investigating The Effectiveness Of Adding Elaboration Tasks To Crosswords For Learning Technical Vocabulary, Warat Khaewratana

Dissertations, Master's Theses and Master's Reports

One challenge in STEM education is the learning of technical terms. In order to reason about higher-order scientific concepts, knowledge of technical vocabulary is often a prerequisite. Improving this knowledge may enhance the learning of higher-order concepts because it reduces cognitive load students experience while learning. To that end, we need innovative learning-aid tools that help students not only in learning and remembering technical terms, but also in applying the learned knowledge to broader concepts. This dissertation investigates the hypothesis that learning gained from crosswords can be used to teach technical terms. Furthermore, I am also examining the hypothesis that …

Study Of Electric Vehicle Smart Charging And Energy Management For Vehicle-Grid Integration Systems, Zhouquan Wu

Dissertations, Master's Theses and Master's Reports

The emerging need of building an efficient Electric Vehicle (EV) charging infrastructure requires the investigation of all aspects of Vehicle-Grid Integration (VGI). This dissertation studies the optimal EV charging control and energy management of VGI system to address the economic benefits of EV charging customers and operation stability of distribution power grids. First of all, a centralized EV charging control method is developed under the transactive energy environment to minimize the EV charging cost and avoid the distribution power grid overloading. The quadratic programming is used to obtain optimized charging control actions. Case studies with hundreds of EVs are conducted …

Kinematics And Preliminary Fema P-695 Evaluation Of The Newz-Breakss Steel Boundary Frame With Buckling Restrained Brace Structural Fuses, Alexander M. Baker

Dissertations, Master's Theses and Master's Reports

Buckling Restrained Braced Frames (BRBFs) have become a popular seismic force resisting system (SFRS) due to their high ductility and energy dissipation. However, BRBFs are also susceptible to large residual drifts, which can make repair difficult. Efforts to reduce the residual drift of BRBFs typically involve special self-centering braces, or by using a dual system in tandem with the BRBF. This study proposes an alternative approach, in which a self-centering steel rocking frame is used as the boundary frame for the BRBF. The proposed system, called the NewZ-BREAKSS Buckling Restrained Braced Frame (NZ-BRBF) utilizes the recently proposed NewZ-BREAKSS (NZ) boundary …

Towards A Circular Economy: Liquid-Fed Fast Pyrolysis Of Waste Polyolefin Plastics, Daniel G. Kulas

Dissertations, Master's Theses and Master's Reports

Plastic usage has quickly grown in recent years as plastics have become an essential part of everyday life. Unfortunately, recycling rates have not matched the increased growth, with the majority of waste plastic landfilled. The strategy of circular economy has been proposed to reuse the waste plastic to create new polymers, thus avoiding both landfilling and the use of virgin raw materials. Achieving a circular economy for plastics requires the development of new technologies capable of recycling plastic waste under a circular economy perspective. In this dissertation, a novel liquid-fed fast pyrolysis process is introduced towards achieving a circular economy. …

Investigating The Role Of Genomic Material Costs In Ecological, Evolutionary, And Invasion Dynamics Using The Solidago Gigantea (Giant Goldenrod) Polyploid Complex, Angela M. Walczyk

Dissertations, Master's Theses and Master's Reports

Polyploidy (whole genome duplication) is large-scale mutation that increases genome size and alters the genomic expression patterns, thus influencing morphological and physiological traits. Given that polyploids and progenitor diploids can be geographically segregated, and that polyploidy is prevalent in invasive plant taxa, polyploidy might affect the ability to tolerate and adapt to variable and/or novel environments. Responsiveness to soil nitrogen (N) and phosphorus (P) availability are of particular interest because 1) nucleic acids (DNA and RNA) require large amounts of N and P for their biosynthesis, potentially disadvantaging polyploids in nutrient-poor environments; and 2) biological invasions usually begin in urbanized …

Molecular Modeling Of High-Performance Thermoset Polymer Matrix Composites For Aerospace Applications, Prathamesh P. Deshpande

Dissertations, Master's Theses and Master's Reports

The global efforts from major space agencies to transport humans to Mars will require a novel lightweight and ultra-high strength material for the spacecraft structure. Three decades of research with the carbon nanotubes (CNTs) have proved that the material can be an ideal candidate for the composite reinforcement if certain shortcomings are overcome. Also, the rapid development of the polymer resin industry has introduced a wide range of high-performance resins that show high compatibility with the graphitic surface of the CNTs. This research explores the computational design of these materials and evaluates their efficacy as the next generation of aerospace …

Evaluation Of Production-Well Performance In Response To Formation Clogging And Rehabilitation For The Keweenaw Bay Tribal Fish Hatchery, Brock O. Howell

Dissertations, Master's Theses and Master's Reports

Temporally, the KBIC (Keweenaw Bay Indian Community) Hatchery wells have manifested general trends of declining specific capacity and higher energy consumption due to mineral precipitation in and around the production wells. Monitoring data, laboratory water analyses, and downhole video logging have confirmed that naturally occurring minerals are precipitating and clogging the screens and, likely, the surrounding formations. The reduction in fluid pressures in and around the well-screens from active pumping wells is typical but, ultimately alters the geochemical and physical conditions such that dissolved minerals precipitate on and around the well-screens, therefore, effectively clogging the well. The clogging from mineral …

On-Ice Detection, Classification, Localization And Tracking Of Anthropogenic Acoustic Sources With Machine Learning, Steven J. Whitaker

Dissertations, Master's Theses and Master's Reports

Arctic acoustics have been of concern in recent years for the US navy. First-year ice is now the prevalent factor in ice coverage in the Arctic, which changes the previously understood acoustic properties. Due to the ice melting each year, anthropogenic sources in the Arctic region are more common: military exercises, shipping, and tourism. For the navy, it is of interest to detect, classify, localize, and track these sources to have situational awareness of these surroundings. Because the sources are on-water or on-ice, acoustic radiation propagates at a longer distance and so acoustics are the method by which the sources …

Examining Cognitive Empathy Elements Within Ai Chatbots For Healthcare Systems, Lamia Alam

Dissertations, Master's Theses and Master's Reports

Empathy is an essential part of communication in healthcare. It is a multidimensional concept and the two key dimensions: emotional and cognitive empathy allow clinicians to understand a patient’s situation, reasoning, and feelings clearly (Mercer and Reynolds, 2002). As artificial intelligence (AI) is increasingly being used in healthcare for many routine tasks, accurate diagnoses, and complex treatment plans, it is becoming more crucial to incorporate clinical empathy into patient-faced AI systems. Unless patients perceive that the AI is understanding their situation, the communication between patient and AI may not sustain efficiently. AI may not really exhibit any emotional empathy at …

Forested Wetland Mitigation: Developing Techniques To Restore Northern White-Cedar On Clay Settling Areas In Northern Michigan, Sean R. Westley

Dissertations, Master's Theses and Master's Reports

When permitted activities degrade or destroy wetlands, mitigation is required by both state and federal laws (Michigan Environment, Great Lakes & Energy (EGLE) and Section 404 of the Clean Water Act). Forested wetlands are considered keystone ecosystems, but restoration of these systems is often limited by the environmental complexities and the slow growth of the long-lived tree species. Using a combination of greenhouse and field experiments, my research goal was to develop techniques to create northern white-cedar (Thuja occidentalis L.) forested wetlands in reclaimed/abandoned mining quarries. There are numerous environmental stressors in the inorganic sediments of reclaimed quarries including high …

A Global Survey Of Volcanic So2 Emissions And Heat Flux Measured From Space, Nelmary Rodríguez-Sepúlveda

Dissertations, Master's Theses and Master's Reports

Over the past two decades, the availability of satellite measurements of volcanic gas emissions and heat flux has driven the development of new methodologies to improve global-scale volcano monitoring. In this work we explored the relationship between volcanic sulfur dioxide (SO₂) emissions and radiant heat flux (RHF) measurements from NASA’s Ozone Monitoring Instrument (OMI) and Moderate Resolution Imaging Spectroradiometer (MODIS), respectively, to gain insight into how it associates to volcanic processes and eruption styles. The OMI SO₂ emissions data are derived from existing databases developed by using the methodology in Fioletov et al. (2016), which contain global, …

Characterization Of Hydraulic Flow Noise Induced By Spool Valves, Carter A. Paprocki

Dissertations, Master's Theses and Master's Reports

The purpose of the hydraulic flow noise research was to investigate the relationship between operational valve parameters and flow noise generation. The primary consideration was correlating the flow noise generated by the valve with the distinct valve open positions. This data would allow future valve designs to account for features that cause increased flow noise and move those features away from high flow valve displacements. By implementing this, companies would be able to design quieter hydraulic systems that will not expose operators to the current levels of sound found on machines. The experiments were conducted using two valves with different …