Engineering Commons^™

Wireless Power Transfer In Autonomous Mobile Microgrids, Carl Greene

Dissertations, Master's Theses and Master's Reports

The ability to autonomously dock unmanned ground vehicles plays a key role in mobile micro-grids, where efficient power transfer is paramount. The approach utilized in this work allows for near-field wireless power transfer in remote locations with minimal support. Establishing a micro-grid power system connection autonomously using wireless power eliminates the arduous task of designing a complex, multiple degrees of freedom (MDOF) robotic arm. The work presented in this thesis focuses on both the hardware and software within the micro-grid system. This particular near-field wireless system consists of a primary and secondary set of modules, comprised of Litz wire coils, …

Permeability, Structural Changes, Flow Regime Transitions In Fuel Cell Catalyst Layers And A Model For Predicting Trapped Saturation For Two-Phase Flow In Porous Media, Karrar Takleef Alofari

Dissertations, Master's Theses and Master's Reports

Proper water management in Proton Exchange Membrane (PEM) fuel cell is important to achieve high performance. Understanding the percolation of the produced water at the cathode catalyst layer (CL) is critical for any robust water management technique. In this study, an ex-situ experimental setup is used to study percolation in the CL at different injection rates and relative humidity (RH) conditions. The results show that increasing the flow rate force the liquid to flow through the bulk of the pores due to the dominant viscous effect. On the other hand, at low injection rates, the capillary becomes dominant and liquid …

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 Of Fuel Selection For A Gasoline Multi-Mode, Spark Ignited – Compression Ignition Engine, Zachary J. Stanchina

Dissertations, Master's Theses and Master's Reports

In this study of fuels of different reactivities and their performance in a low-temperature combustion (LTC) engine. The engine was a 2.2L CRDI engine code D4HB provided by industry partner Hyundai America Technical Center inc. (HATCI). The engine was instrumented with in-cylinder pressure sensors allowing for monitoring of the combustion process.

First, the engine was operated with standard US pump grade gasoline, Research Octane number (RON) 91 E10, to find initial operation conditions as well as control points of stable operation for daily checks on system conditions.

Tested were 8 different fuel blends, the four base blends were provided by …

A Coupled Viscoplastic-Damage Constitutive Model For Semicrystalline Polymers, Jeffrey Wiersma

Dissertations, Master's Theses and Master's Reports

The ease of processing, recyclability, and ideal cost to weight ratio makes the semi-crystalline polymers attractive in the aerospace, automotive, and defense industries. Use of semicrystalline polymers for engineering design requires a thorough understanding of their response to mechanical deformation, rate of loading, temperature, and failure mechanisms. However, there lacks a generally agreed upon constitutive model to capture the large deformation elastic-viscoplastic response of semicrystalline polymers while incorporating the strain-rate dependence and damage behavior. To address this aspect, the objective of this dissertation is to develop an elastic-viscoplastic constitutive model to predict the rate dependent, large deformation response of semicrystalline …

Per- And Polyfluoroalkyl Substances Mitigation From Contaminated Groundwater Using Halophyte And Cow Bone Biochars, Bailey Papes

Dissertations, Master's Theses and Master's Reports

Per- and polyfluoroalkyl substances (PFAS) groundwater contamination is a growing concern for the Brackish Groundwater National Desalination Research Facility. Two of the four wells onsite are contaminated with perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and perfluorohexane sulfonic acid (PFHxS). The removal of PFAS by adsorption onto powder activated carbon (PAC) is promising, but the production of PAC is energy intensive and expensive. A potential cost-effective alternative to PAC is biochar. This study quantified the capacities of two halophyte biochars, cow bone biochar and PAC to adsorb PFOA, PFOS, and PFHxS from brackish groundwater. The three biochars were ineffective at …

Microscale Transverse Compression Modeling: A Comparative Study Of The Analytical Mac/Gmc Methods To Experimental Results, Emily Zeitunian

Dissertations, Master's Theses and Master's Reports

Composite materials require a multi-scale approach to fully understand its behavior. At the micro level, material behavior analysis is conducted most often using numerical or analytical approaches. These models, however, require validation from experimental data to ensure material predictions are accurate. This study compares a semi-analytical micromechanical analysis tool, MAC/GMC, to experimental results of in-situ microscale transverse compression testing conducted at AFRL facilities. Effective properties, stress-strain curves, stress and strain fields, and damage predictions are compared with experimental outputs. Both generalized method of cells (GMC) and high-fidelity generalized method of cells (HFGMC) theories implemented within MAC/GMC show results that agree …

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, …

Atomistic-Continuum Membrane And Machine Learning Models For Two-Dimensional Materials, Upenda Yadav

Dissertations, Master's Theses and Master's Reports

“What could we do with layered structures with just the right layers?” asked Richard Feynman in his famous 1959 lecture, “There’s plenty of room at the bottom.” With the help of the amazing developments of the past several years, we are coming close to answering that question. In 2004, graphene was first isolated from graphite and only six short years later it won the Nobel Prize in Physics. Graphene is one atomic layer of Carbon, it is the thinnest and yet the strongest materials we have ever seen. It is 200 times stronger than its equivalent weight in steel and …

Design And Analysis Of Marangoni-Driven Robotic Surfers, Mitchel L. Timm

Dissertations, Master's Theses and Master's Reports

We designed and experimentally studied the dynamics of two robotic systems that surf along the water-air interface. The robots were self-propelled by means of creating and maintaining a surface tension gradient resulting from an asymmetric release of isopropyl alcohol (IPA). The imbalance in the distribution of surface tension surrounding the robots generates a propulsive force commonly referred to as Marangoni propulsion. First, we considered a single surfer, which was custom-made with novel control mechanisms that allow for both forward motion and steering to be remotely adjusted solely through the manipulation of local surface stresses. We analyzed the performance of this …

Collective Hydrodynamics Of Robotic Fish, Rohit S. Pandhare

Dissertations, Master's Theses and Master's Reports

Many animals in nature travel in groups either for protection, survival, or endurance. Among these, fish do so under the burden of hydrodynamic loads, which incites questions as to the significance of the multi-body fluid-mediated interactions that facilitate collective swimming. We study such interactions in the idealized setting of a rotational array of robotic fish whose tails undergo a prescribed flapping motion, but whose swimming speed is determined as a natural result of the hydrodynamic effects. Specifically, we examine how the measured collective speed of the swimmers varies with the imposed frequency and amplitude of their tail flapping, and with …

The Photo-Transformation Of Free Methionine In The Presence Of Surrogate And Standard Isolate Dissolved Organic Matter Under Sunlit Irradiation, Benjamin J. Mohrhardt

Dissertations, Master's Theses and Master's Reports

Sulfur (S)-containing amino acids are key sources of carbon, nitrogen, and sulfur involved in protein synthesis, protein function, and providing energy for microbial growth. Dissolved free and combined methionine is one of two S-containing amino acids incorporated into proteins and has been attributed to their stability and function. The oxidation of methionine has received considerable attention given its ubiquitous presence in most biological systems and has been associated with losses in protein function and pathological disorders. In natural waters, methionine is rapidly and selectively taken up by microorganisms to achieve cellular requirements of carbon, nitrogen, and sulfur. The abiotic transformation …

Concept Evaluation And Development Of A Novel Approach For Integration Of Turbogeneration, Electrification And Supercharging On Heavy Duty Engines, Satyum Joshi

Dissertations, Master's Theses and Master's Reports

While many technologies such as electrically assisted turbocharging, exhaust energy recovery and mild hybridization have already proven to significantly increase heavy-duty engine efficiency, the key challenge to their widespread adoption has been their cost effectiveness and packaging. This research specifically addresses these challenges through evaluation and development of a novel technology concept termed as the Integrated Turbogeneration, Electrification and Supercharging (ITES) system. The concept integrates a secondary compressor, a turbocompound/expander turbine and an electric motor through a planetary gearset into the engine cranktrain. The approach enables a reduced system cost and space-claim, while maximizing the efficiency benefits of independent technologies. …

Length-Scale-Dependent Stress Relief Mechanisms In High Purity Indium, Fereshteh Mallakpour

Dissertations, Master's Theses and Master's Reports

Lithium-ion batteries are widely used in portable electronics and electric vehicles. However, due to the presence of flammable liquid electrolytes, these devices fail catastrophically when the cell experiences a short circuit. One attractive solution to this problem is a solid-state battery. As the name implies, the flammable liquid electrolyte is replaced by a non-flammable solid-state electrolyte (SSE). The unexpected, yet frequently observed failure mechanism in these devices is the formation and growth of lithium dendrites originating at the interface between the lithium anode and the SSE. As the dendrites grow, device performance degrades. Once the dendrites completely penetrate the SSE, …

Experimental Analysis And Computer Simulation Of A Laboratory-Scale Intermittent Water Supply System, Brian Rivers

Dissertations, Master's Theses and Master's Reports

Intermittent water systems (IWS) are prevalent throughout developing regions of the world. However, few tools exist to predict IWS performance because modeling transient flow is difficult: IWS networks can experience widely fluctuating conditions, ranging from completely empty to completely full (pressurized flow). An experimental IWS, consisting of a 50.75-gallon reservoir, an elevated distribution network, and four outlets was constructed to study the hydraulics of IWS. Three experiments were run on the system that represented two falling-head scenarios and a constant-head scenario. Computer simulation models of the experimental IWS were developed in EPANET 2.2.0 and EPA-SWMM 5.1, which are open-source modeling …

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 …

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 …

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 …

An Experimental Study Towards Underwater Propulsion System Using Structure Borne Traveling Waves, Shreyas Suhas Gadekar

Dissertations, Master's Theses and Master's Reports

The method of generating steady-state structure-borne traveling waves underwater in an infinite media creates abundant opportunities in the field of propulsive applications, and they are gaining attention from several researchers. This experimental study provides a framework for harnessing traveling waves in a 1D beam immersed under quiescent water using two force input methods and providing a motion to an object floating on the surface of the water.

In this study, underwater traveling waves are tailored using structural vibrations at five different frequencies in the range of 10Hz to 300Hz. The resulting fluid motion provides a propulsive thrust that moves a …

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 …

Hardware In The Loop Implementation And Simulations Of A Wave Energy Converter Using Typhoon Hil And Speedgoat, Pranav Nair

Dissertations, Master's Theses and Master's Reports

Several studies have indicated that electricity production is the prime source of greenhouse emissions, more than flying and driving combined. Hence, over the past few decades, there has been a significant rise in the need for clean energy to achieve the targets in emissions reduction. It has been observed that the share of renewable energy sources in the percentage of total electricity production is rising, but, according to climate experts, the transition needs to speed up. Hence, it is significant to study and develop underutilized renewable energy sources.

One of these underutilized renewable energy sources is wave energy. It has …

Measuring The Physicochemical Properties Of Viral Vectors To Enhance Gene Therapy Production, Oluwatoyin Areo

Dissertations, Master's Theses and Master's Reports

Gene therapy is a therapeutic intervention designed to correct single gene disorders. AAV has been identified as a suitable vector for delivering therapeutic genes. However, the use of AAV has been hampered by manufacturing challenges inclusive of low virus recovery, and the presence of AAV without the gene of interest (empty capsids). To solve these problems, we characterized the charge and hydrophobicity of AAV, and surrogate viruses using chemical force microscopy (CFM). CFM uses a modified atomic force microscope (AFM) probe to measure the adhesion force between a virus particle and a functional chemistry.The virus particles to be measured are …

Eager Scheduling Of Dependent Instructions, Kurush Kasad

Dissertations, Master's Theses and Master's Reports

Modern superscalar processors are able to potentially issue and execute multiple instructions per cycle. Several techniques over the years have focused on increasing the Instruction Level Parallelism (ILP) that a processor can exploit. However, there are many limitations of ILP that hinder performance, chief of them being the chain of dependencies between instructions that stops instructions from being executed in parallel.

We propose a new micro-architecture design which extends the superscalar pipeline with a data-flow pipeline where the dataflow part identifies immediately dependent instructions and executes them early. The dataflow pipeline is able to identify redundant instructions, track changes in …

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 …

Image-Data-Driven Deep Learning For Slope Stability Analysis, Behnam Azmoon

Dissertations, Master's Theses and Master's Reports

Landslides cause major infrastructural issues, damage the environment, and cause socio-economic disruptions. Therefore, various slope stability analysis methods have been developed to evaluate the stability of slopes and the probability of their failure. This dissertation attempts to take advantage of the recent advancements in remote sensing and computer technology to implement a deep-learning-based landslide prediction method.

Considering the novelty of this approach, this dissertation leads with proof-of-concept studies to evaluate and establish the suitability of deep learning models for slope stability analysis. To achieve this, a simulated 2D dataset of slope images was created with different geometries and soil properties. …

Rebuilding Fish-Human Relationships By Quantifying Combined Toxicity And Evaluating Policy Related To Legacy Contamination, Emily Shaw

Dissertations, Master's Theses and Master's Reports

The central theme of this dissertation is relationships – building relationships as research partnerships, disrupting relationships through chemical contamination, and upholding existing relationships (i.e., responsibilities) to address industrial legacies. In partnership with the Keweenaw Bay Indian Community Lake Superior Band of Chippewa Indians (KBIC), this dissertation focuses on rebuilding fish-human relationships within the context of chemical contamination. By quantifying combined toxicity and evaluating the efficacy of cleaning up contamination, conclusions from this work help empower people to maintain practices and knowledges related to fish.

In chapter 1, I positioned myself, a white, American settler scholar, within the context of Indigenous …

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 …

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 …

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 …