Engineering Commons^™

High Injection Pressure Dme Ignition And Combustion Processes: Experiment And Simulation, Xiucheng Zhu

Dissertations, Master's Theses and Master's Reports

With nearly smokeless combustion, Dimethyl Ether (DME) can be pressurized and used as a liquid fuel for compression-ignition (CI) combustion. However, due to its lower heating value and liquid density compared with diesel fuel, DME has a smaller energy content per unit volume. To obtain an equivalent energy content of diesel, approximately 1.86 times more quantity of DME is required. This can be addressed by a larger nozzle size or higher injection pressure. However, the effect of high injection pressure on DME spray combustion characteristics have not yet been well understood. In order to fill this gap, spray and combustion …

Design Of A Viability Test For Freshwater Prawn Aquaculture Of Two Different Macrobrachium Species In Aneityum, Vanuatu, Cameron Koizumi

Dissertations, Master's Theses and Master's Reports

There is a unique opportunity for freshwater prawn aquaculture on the island of Aneityum in the Republic of Vanuatu. Aneityum has an abundance of fresh water, the streams and rivers on Aneityum are the natural habitat for a freshwater prawn species, Macrobrachium lar, and the people on Aneityum regularly work on projects using communal labor for the benefit of the community. Aneityum also hosts 40 – 120 cruise ships a year, bringing hundreds of thousands of tourists to Aneityum and the nearby islet Mystery Island which creates a readily available market in which to sell freshwater prawns.

The objective …

Optimization And Comparison Of Over-Expanded And Other High Efficiency Four-Stroke Spark-Ignited Boosted Engines, Zhuyong Yang

Dissertations, Master's Theses and Master's Reports

Recent fuel economy and emission regulations are the major concern of the research and development of modern internal combustion engine. Such technologies include variable valve timing (VVT), direct injection (DI), turbocharging, downsizing, and over-expanded cycle are used by many manufacturers to improve engine fuel economy or increase power density.

Current Atkinson cycle technology in the production engine is mainly realized by an advanced valvetrain system to reduce the effective compression ratio while maintaining the same expansion ratio. Another approach to realize over-expanded cycle engine is to utilize a multi-link cranktrain mechanism. Although the Atkinson cycle was originally patented in the …

An Experimental Study Of A Passive Nox Adsorber (Pna) For The Reduction Of Cold Start Diesel Emissions, Conor Berndt

Dissertations, Master's Theses and Master's Reports

Medium and heavy-duty diesel engines contribute nearly a third of all NOx emissions nationwide. Further reduction of NOx emissions from medium and heavy-duty diesel engines is needed in order to meet National Ambient Air Quality Standards (NAAQS) for ambient particulate matter and ozone. Current diesel engine aftertreatment systems are very efficient at reducing NOx emissions at exhaust temperatures above 200 °C, however at exhaust temperatures below 200 °C there are significant NOx emissions at the tailpipe. Therefore, a reduction of diesel engine cold start and low speed/load operation emissions, where exhaust temperatures are below 200 °C, is needed. Utilizing a …

Spread Of Emerging Contaminants In Water Distribution Systems, Danielle Pilarski

Dissertations, Master's Theses and Master's Reports

Emerging contaminants are a growing concern to humans and the environment. Studies have shown these contaminants are present in the environment through continuous release into surface waters from wastewater treatment effluent, manufacturing processes, and agricultural use. The effects of these contaminants have been observed in ecological studies, but they have not yet been well studied for long term exposure in humans. These emerging contaminants have also not been well studied to determine the rates at which they decay or how they move through distribution systems. This study aims to determine the importance of decay rate on concentration throughout a distribution …

A Preliminary Sustainability Analysis Of Producing Class A Biosolids With Conventional And Low-Cost, Low-Tech Processes, Janna Brown

Dissertations, Master's Theses and Master's Reports

Producing Class A biosolids is a beneficial way to reuse wastewater sludge. Low-cost, low-tech (LCLT) processes are attractive to small water resource recovery facilities (WRRF) because of their low capital costs and simple designs. This study examined the sustainability of conventional and LCLT processes at small WRRFs. The environmental impacts were determined by conducting life cycle assessments. Cost analyses determined the economic impacts. The social impacts were analyzed by investigating case studies and surveys of social response to biosolids. The environmental, economic, and social impacts were normalized, and each technology received an overall score. The technologies studied were direct heat …

Discontinuous Galerkin Methods For Convection-Diffusion Equations And Applications In Petroleum Engineering, Nattaporn Chuenjarern

Dissertations, Master's Theses and Master's Reports

This dissertation contains research in discontinuous Galerkin (DG) methods applying to convection-diffusion equations. It contains both theoretical analysis and applications. Initially, we develop a conservative local discontinuous Galerkin (LDG) method for the coupled system of compressible miscible displacement problem in two space dimensions. The main difficulty is how to deal with the discontinuity of approximations of velocity, u, in the convection term across the cell interfaces. To overcome the problems, we apply the idea of LDG with IMEX time marching using the diffusion term to control the convection term. Optimal error estimates in L^infinity(0, T; L^{2 …}

Enhancing The Resolution Of Imaging Systems By Spatial Spectrum Manipulation, Wyatt Adams

Dissertations, Master's Theses and Master's Reports

Much research effort has been spent in the 21st century on superresolution imaging techniques, methods which can beat the diffraction limit. Subwavelength composite structures called ``metamaterials" had initially shown great promise in superresolution imaging applications in the early 2000s, owing to their potential for nearly arbitrary capabilities in controlling light. However, for optical frequencies they are often plagued by absorption and scattering losses which can decay or destroy their interesting properties. Similar issues limit the application of other superresolution devices operating as effective media, or metal films that can transfer waves with large momentum by supporting surface plasmon polaritons. In …

Electro-Optic Antenna Elements For Passive Phased Array Radar, Evan Gawron

Dissertations, Master's Theses and Master's Reports

Passive phased antenna arrays are utilized in military and civilian radar systems to determine the received signal origination. Phased array placement for optimal reception is challenging due to the required supporting electronic hardware and the associated coaxial cabling that typically accompanies each antenna channel. Low noise amplifiers and frequency conversion hardware add size and complexity, limiting possible positions for phased array placement. Eliminating required phased array electronic subcomponents without sacrificing function would allow placement onto smaller agile platforms, such as unmanned systems and rapid deployment networks. Electro-optic (EO) antenna elements utilize an optical waveguide embedded between the antenna and ground …

3d Printing In Low Resource Healthcare Settings: Analysis Of Potential Implementations, Alenna Beroza

Dissertations, Master's Theses and Master's Reports

3D printing has gained significant momentum in the past ten years, and its unique advantages make it especially ideal for use in low resource healthcare settings, where many designs have already been successfully implemented. Yet, little has been studied on how 3D printing can be sustainably and functionally implemented in low resource healthcare systems as a manufacturing practice. In this report, three business models are proposed for this implementation: In-House Operator, Independent Operator, and Print Farm. These models were then tested over four months in Kisumu county, Kenya, at two workshops and seven public hospitals. I worked with local medical …

Degradable Zinc Material Characteristics And Its Influence On Biocompatibility In An In-Vivo Murine Model, Roger J. Guillory Ii

Dissertations, Master's Theses and Master's Reports

Biodegradable stents based on zinc have been under development since their introduction in 2013. While metallic zinc is highly ductile, it unfortunately lacks the mechanical strength required for arterial stents. This has led to the development of an abundance of novel zinc-based materials, with the aim of improving the mechanical strength without sacrificing too much ductility. Although these materials are intended to function and slowly degrade within an artery, most zinc-based materials have been developed without deep consideration for their biological effects.

The present work explores the biological effects elicited by zinc-based materials implanted within the arterial system. The biological …

Hometracker: A Household Information Feedback System For Food/Energy/Water Metabolism, Nichole Mackey

Dissertations, Master's Theses and Master's Reports

The Food, Energy and Water Conscious (FEWCON) project seeks to understand how food, energy and water (FEW) as independent resources within households are connected. In the main study of the project, intervention messages that link household FEW consumption to equivalent climate consequences are pushed to the households. The goal of the FEWCON study is to determine potential intervention messages that influence household FEW consumption behavior.

A key component of the FEWCON study is a web application named HomeTracker (Household Metabolism Tracker) which collects FEW consumption data within households, then uses this data to select consumption-specific feedback to the homeowners. To …

Application Of Sensor Fusion For Si Engine Diagnostics And Combustion Feedback, Fnu Muralidhar Nischal

Dissertations, Master's Theses and Master's Reports

Shifting consumer mindsets and evolving government norms are forcing automotive manufacturers the world over to improve vehicle performance and also reduce greenhouse gas emissions. A critical aspect of achieving future fuel economy and emission targets is improved powertrain control and diagnostics.

This study focuses on using a sensor fusion based approach to improving control and diagnostics in a gasoline engine. A four cylinder turbocharged engine was instrumented with a suite of sensors including ion sensors, exhaust pressure sensors, crank position sensors and accelerometers. The diagnostic potential of these sensors was studied in detail. The ability of these sensors to detect …

Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar

Dissertations, Master's Theses and Master's Reports

Coherent light - such as that from a laser - on interaction with biological tissues, undergoes scattering. This scattered light undergoes interference and the resultant field has randomly added phases and amplitudes. This random interference pattern is known as speckles, and has been the subject of multiple applications, including imaging techniques. These speckle fields inherently contain optical vortices, or phase singularities. These are locations where the intensity (or amplitude) of the interference pattern is zero, and the phase is undefined.

In the research presented in this dissertation, dynamic speckle patterns were obtained through computer simulations as well as laboratory setups …

Community Detection In Complex Networks And Application To Dense Wireless Sensor Networks Localization, Sakineh Yazdanparast

Dissertations, Master's Theses and Master's Reports

Complex network analysis is applied in numerous researches. Features and characteristics of complex networks provide information associated with a network feature called community structure. Naturally, nodes with similar attributes will be more likely to form a community. Community detection is described as the process by which complex network data are analyzed to uncover organizational properties, and structure; and ultimately to enable extraction of useful information. Analysis of Wireless Sensor Networks (WSN) is considered as one of the most important categories of network analysis due to their enormous and emerging applications. Most WSN applications are location-aware, which entails precise localization of …

Multi-Scale, Capillary Assisted Copper Surfaces For Enhanced Pool Boiling Heat Transfer Processes, Chetan Agarwal

Dissertations, Master's Theses and Master's Reports

Phase-change heat transfer through pool boiling process offers a promising thermal management solution in applications wherein conventional air or single-phase liquid-based cooling methods prove inefficient such as for high-power electronics. Pool boiling process, which utilizes the latent heat of evaporation, provides a robust and efficient way to efficiently dissipate the excessive heat generated in a small footprint area in particular as seen in CPUs (Central Processing Units), GPUs (Graphics Processing Units), LEDs (Light Emitting Diodes), radars, and other demanding computing, sensing and surveillance electronics. Although boiling process has been studied for over five decades, it has not been yet adapted …

Estimation Of Multi-Directional Ankle Impedance As A Function Of Lower Extremity Muscle Activation, Lauren Knop

Dissertations, Master's Theses and Master's Reports

The purpose of this research is to investigate the relationship between the mechanical impedance of the human ankle and the corresponding lower extremity muscle activity. Three experimental studies were performed to measure the ankle impedance about multiple degrees of freedom (DOF), while the ankle was subjected to different loading conditions and different levels of muscle activity. The first study determined the non-loaded ankle impedance in the sagittal, frontal, and transverse anatomical planes while the ankle was suspended above the ground. The subjects actively co-contracted their agonist and antagonistic muscles to various levels, measured using electromyography (EMG). An Artificial Neural Network …

Using Frequency Based Substructuring To Optimize Multi-Axis Resonant Plate Shock Tests, Erica M. Jacobson

Dissertations, Master's Theses and Master's Reports

Resonant plate pyroshock tests only offer to test one component axis at a time, while the qualification pyroshock tests often have three single-axis specifications to meet. There is an interest in creating a multi-axis test environment from the single-axis resonant plate parts to save testing time, create a more realistic test environment, and monitor the possibility of an overtest. To investigate this, LaGrange-multiplier frequency based substructuring was implemented to virtually arrange the single-axis resonant plate subsystems into different assembly configurations and mathematically calculate the new assembly dynamics. A shock response spectrum was calculated from the new assembly dynamics through an …

Online Learning Of The Spatial-Temporal Channel Variation In Underwater Acoustic Communication Networks, Wensheng Sun

Dissertations, Master's Theses and Master's Reports

Influenced by environmental conditions, underwater acoustic (UWA) communication channels exhibit spatial and temporal variations, posing significant challenges for UWA networking and applications. This dissertation develops statistical signal processing approaches to model and predict variations of the channel and relevant environmental factors. Firstly, extensive field experiments are conducted in the Great Lakes region. Three types of the freshwater river/lake acoustic channels are characterized in the aspects of statistical channel variations and sound propagation loss, including stationary, mobile and under-ice acoustic channels. Statistical data analysis shows that relative to oceanic channels, freshwater river/lake channels have larger temporal coherence, higher correlation among densely …

Algorithms And Optimal Control For Spacecraft Magnetic Attitude Maneuvers, Mohammed Desouky

Dissertations, Master's Theses and Master's Reports

This study focused on providing applicable control solutions for spacecraft magnetic attitude control system. Basically, two main lines are pursued; first, developing detumbling control laws and second, an improvement in the three-axis attitude control schemes by extending magnetic rods activation time.

Spacecraft, after separation from the launching mechanism, experiences a tumbling phase due to an undesired angular momentum. In this study, we present a new efficient variant of the B-dot detumbling law by introducing a substitute of the spacecraft angular velocity, based on the ambient magnetic field data. This B-dot law preserves the orthogonality, among the applied torque, dipole moment …

Assessing Benthic Recovery In The Torch Lake Aoc, Anya Clare Leach

Dissertations, Master's Theses and Master's Reports

Torch Lake, located in Michigan’s Upper Peninsula, was a site of copper ore processing from the 1860s through the 1960s. During this time, various mining by-products were deposited into the lake and along its shoreline, including mine tailings and associated heavy metals contaminants (e.g., copper). It was anticipated that natural sediment deposition would cover and attenuate toxic sediments over time, but a comprehensive assessment of the benthos has not been performed since a baseline survey conducted in 1999 and 2000. This study was conducted in 2018 to evaluate the current benthic community status as well as sediment composition and metal …

Experimental And Numerical Simulation Of Split Hopkinson Pressure Bar Test On Borosilicate Glass, Mayank K. Bagaria

Dissertations, Master's Theses and Master's Reports

This study is an extension to the design of ceramic materials component exposed to bullet impact. Owing to the brittle nature of ceramics upon bullet impact, shattered pieces behave as pellets flying with different velocities and directions, damaging surrounding components. Testing to study the behavior of ceramics under ballistic impact can be cumbersome and expensive. Modeling the set-up through Finite Element Analysis (FEA) makes it economical and easy to optimize. However, appropriately incorporating the material in modeling makes laboratory testing essential. Previous efforts have concentrated on simulating crack pattern developed during 0.22 caliber pellet impact on Borosilicate glass. A major …

Automotive Driveline Backlash State And Size Estimator Design For Anti-Jerk Control, Kaushal Kumar Darokar

Dissertations, Master's Theses and Master's Reports

Vehicle drivability is an important factor which more and more customers have started assessing before buying a vehicle. Customers carry out this assessment based on both vehicle reviews/ratings and based on the test drives. One of common maneuver which a customers perform during the test drive is sudden accelerator pedal tip-in or tip-out to accelerate or coast the vehicle. Clunk and shuffle are the phenomena that usually occur during this scenario causing driver discomfort. The clunk and shuffle are caused by the backlash and compliance physical properties of the driveline. Consequently, control strategy needs to be developed which can provide …

Pathogen And Indicator Organism Inactivation And Quantification For Low-Cost Low-Tech Biosolids Treatment, Karina Eyre

Dissertations, Master's Theses and Master's Reports

Biosolids are a by-product of municipal wastewater treatment which, when treated to reduce pathogens, can be land applied as a fertilizer. Class A biosolids must contain low pathogen levels and are unrestricted in their use. This thesis describes methods to identify pathogen and indicator organism (PIO) inactivation mechanisms and PIO inactivation rates for use in low-cost low-tech Class A processes. Procedures to control the levels of spiked bacteria and viruses, total solids, volatile fatty acids, pH, and temperature in biosolids are described for their use in laboratory experiments. Methods for coliphage in biosolids as a surrogate for total enteric viruses …

Integrated Computational Materials Engineering (Icme) Investigation Of Electrical Conductivity And Thermodynamic Stability For Precipitation Strengthened Al-Zn-Zr And Al-Zn-Ni Ternary Alloys, Oladeji Fadayomi

Dissertations, Master's Theses and Master's Reports

High electrical conductivity Al-Zn-TM (TM=Transition metals) alloys with improved mechanical properties and thermal resistance are developed with an integrated computational material engineering (ICME) strategy. From a series of ab initio density functional theory (DFT) simulations assessing combinations of ternary alloys, Al-Zn-Ni and Al-Zn-Zr are determined as alloys with relatively high electrical conductivity compared to several other ternary Al alloy combinations. The zero-temperature stable structure of precipitates formed in these alloys are determined from computed enthalpy of formation as L1₂, with particular focus of examining the influence of Zn on stabilizing the desired L1₂ precipitate phase.

Scanning transmission …

The Role Of Ephemeral Stratification, Anoxia, And Entrainment In Mediating Spatiotemporal Trophic State Dynamics In A Lake Michigan Drowned River Mouth System (Mona Lake, Mi), Hayden Henderson

Dissertations, Master's Theses and Master's Reports

Mona Lake, MI (a drowned river mouth system) has become eutrophic as result of cultural eutrophication. The integrated monitoring effort and subsequent modeling (LAKE2K) reported on here has shifted the management focus to internal phosphorus loads (60 percent of annual load, 90 percent of load during the stratified and anoxic period) as a necessary precursor to trophic state change. Sediment phosphorus release can yield extreme elevations (> 1 mgSRP/L) of bottom water soluble reactive phosphorus (SRP), with blooms of potentially toxic cyanobacteria (largely Microcystis) occurring annually. Such blooms are ascribable to stochastic mixing and phosphorus entrainment to the surface waters, …

Improved Methods For The Quantification Of Viable Ascaris Suum And Application To Biosolids, Tanner Keyzers

Dissertations, Master's Theses and Master's Reports

The current method for detection of Ascaris ova in biosolids and wastewater has several drawbacks including being labor and time intensive as well as being difficult to quantify viable ova that have larvated during treatment. The goal of this thesis was to improve several methods for the detection and quantification of Ascaris ova during long term-storage of biosolids including improvement of quantifying viable ova using a heat and bleach treatment to promote movement of larvae inside of ova, and comparison of the traditional microscopic method with qPCR and PMA-qPCR to prevent the false-positive results. Improved methods to promote movement of …

A Hybrid-Powered Wireless System For Multiple Biopotential Monitoring, Shawn Li

Dissertations, Master's Theses and Master's Reports

Chronic diseases are the top cause of human death in the United States and worldwide. A huge amount of healthcare costs is spent on chronic diseases every year. The high medical cost on these chronic diseases facilitates the transformation from in-hospital to out-of-hospital healthcare. The out-of-hospital scenarios require comfortability and mobility along with quality healthcare. Wearable electronics for well-being management provide good solutions for out-of-hospital healthcare. Long-term health monitoring is a practical and effective way in healthcare to prevent and diagnose chronic diseases. Wearable devices for long-term biopotential monitoring are impressive trends for out-of-hospital health monitoring. The biopotential signals in …

Closed Loop Energy Maximizing Control Of A Wave Energy Converter Using An Estimated Linear Model That Approximates The Nonlinear Froude-Krylov Force, Yaqzan Mohd Yaqzan

Dissertations, Master's Theses and Master's Reports

Wave energy converters (WECs) exploit ocean wave energy and convert it into useful forms such as electricity. But for WECs to be successful on a large scale, two primary conditions need to be satisfied. The energy generated must satisfy the network requirements, and second, energy flow from waves to the grid needs to be maximized. In this dissertation, we address the second problem. Most control techniques for WECs today use the Cummins' linear model to simulate WEC hydrodynamics. However, it has been shown that under the application of a control force, where WEC motions are amplified, the linear model diverges …

Investigation Of Long Term Pillar Stability In An Abandoned Gypsum Mine Based On Dissolution Models, Mohammadhossein Sadeghiamirshahidi

Dissertations, Master's Theses and Master's Reports

The abandoned Domtar Mine in Grand Rapids, MI underlies Interstate I-196. The mine operated for over 140 years, mining a 30-meter-deep, four-meter thick gypsum seam. In 2000, the mine was abandoned with the removal of the mine’s dewatering pumps allowing groundwater to flood the mine. The initial flooding resulted in saturating the mine pillars along with some amount of pillar dissolution. Overtime, gypsum dissolution would cease as the water becomes saturated with the gypsum dissolution products. The mine, however, is located adjacent to the Grand River and has groundwater moving through the mine resulting in the potential for continuing dissolution. …