Engineering Commons^™

Improving Startability And Reducing Emissions In Flexfuel Spark Ignition Direct Injection Variable Cam Timing Engine, Vaibhav S. Kale

Dissertations, Master's Theses and Master's Reports - Open

Experimental work and analysis was done to investigate engine startup robustness and emissions of a flex-fuel spark ignition (SI) direct injection (DI) engine. The vaporization and other characteristics of ethanol fuel blends present a challenge at engine startup. Strategies to reduce the enrichment requirements for the first engine startup cycle and emissions for the second and third fired cycle at 25°C ± 1°C engine and intake air temperature were investigated.

Research work was conducted on a single cylinder SIDI engine with gasoline and E85 fuels, to study the effect on first fired cycle of engine startup. Piston configurations that included …

The Effect Of Annealing On Amorphous Silicon Based Solar Photovoltaic Thermal System (Pv/T) And Appropriate Global Dispatch Strategies, Joseph Rozario

Dissertations, Master's Theses and Master's Reports - Open

Previous work has shown that high-temperature short-term spike thermal annealing of hydrogenated amorphous silicon (a-Si:H) photovoltaic thermal (PVT) systems results in higher electrical energy output. The relationship between temperature and performance of a-Si:H PVT is not simple as high temperatures during thermal annealing improves the immediate electrical performance following an anneal, but during the anneal it creates a marked drop in electrical performance. In addition, the power generation of a-Si:H PVT depends on both the environmental conditions and the Staebler-Wronski Effect kinetics. In order to improve the performance of a-Si:H PVT systems further, this paper reports on the effect of …

Participant Impacts From A Participatory Water Modeling Workshop In The Sonora River Basin, Mexico, David J. Kossak

Dissertations, Master's Theses and Master's Reports - Open

Much of the research in the field of participatory modeling (PM) has focused on the developed world. Few cases are focused on developing regions, and even fewer on Latin American developing countries. The work that has been done in Latin America has often involved water management, often specifically involving water users, and has not focused on the decision making stage of the policy cycle. Little work has been done to measure the effect PM may have on the perceptions and beliefs of decision makers. In fact, throughout the field of PM, very few attempts have been made to quantitatively measure …

In-Situ Tem Plasma Chip Nanofabrication And Characterization, Xuebo Cui

Dissertations, Master's Theses and Master's Reports - Open

A silicon-based microcell was fabricated with the potential for use in in-situ transmission electron microscopy (TEM) of materials under plasma processing. The microcell consisted of 50 nm-thick film of silicon nitride observation window with 60μm distance between two electrodes. E-beam scattering Mont Carlo simulation showed that the silicon nitride thin film would have very low scattering effect on TEM primary electron beam accelerated at 200 keV. Only 4.7% of primary electrons were scattered by silicon nitride thin film and the Ar gas (60 μm thick at 1 atm pressure) filling the space between silicon nitride films. Theoretical calculation also showed …

Water Access And Maintenance In Karonga, Malawi, Donald A. Norris

Dissertations, Master's Theses and Master's Reports - Open

This report is a case study of how Mwangalala community accesses water and how that access is maintained. Mwangalala community is located in the northern tip of Karonga district in Malawi, Africa. The case study evaluates how close the community is to meeting target 10 of the Millennium Development Goals, sustainable access to safe drinking water, and evaluates the current water system through Human Centered Design’s criteria of desirability, feasibility, and viability. It also makes recommendations to improve water security in Mwangalala community.

Data was collected through two years of immersive observation, interviews with 30 families, and observing two wells …

Virus Purification, Detection And Removal, Khrupa Saagar Vijayaragavan

Dissertations, Master's Theses and Master's Reports - Open

The biopharmaceutical industry has a growing demand and an increasing need to improve the current virus purification technologies, especially as more and more vaccines are produced from cell-culture derived virus particles. Downstream purification strategies can be expensive and account for 70% of the overall manufacturing costs. The economic pressure and purification processes can be particularly challenging when the virus to be purified is small, as in our model virus, porcine parvovirus (PPV). Our efforts are focused on designing an easy, economical, scalable and efficient system for virus purification, and we focused on aqueous two-phase systems. Industry acceptable standards for virus …

A Study Of Acoustic Boom Generation Due To Vibro-Acoustic Coupling In Passenger Cars, Mayuresh Pathak

Dissertations, Master's Theses and Master's Reports - Open

This thesis aims at understanding the vibro-acoustic behavior related to vehicle boom in passenger cars. Acoustic boom in the 40 Hz frequency range is studied on a 2013 Chevrolet Cruze LTZ model. Impact testing, full vehicle structural and acoustic modal tests are first performed to understand, locate and test the boom phenomenon and the fluid-structure interaction between the vehicle structure and acoustic cavity. Later, different iterations like effect of door cavities, trunk cavity and rear seats are also tested to understand their participation. LMS Test.Lab software is used for data acquisition, processing and analysis of the test results.

Finite Element …

Utilizing Dielectrophoresis To Determine The Physiological Differences Of Eukaryotic Cells, Tayloria Nicole Gail Adams

Dissertations, Master's Theses and Master's Reports - Open

Type 1 diabetes affects over 108,000 children, and this number is steadily increasing. Current insulin therapies help manage the disease but are not a cure. Over a child’s lifetime they can develop kidney disease, blindness, cardiovascular disease and many other issues due to the complications of type 1 diabetes. This autoimmune disease destroys beta cells located in the pancreas, which are used to regulate glucose levels in the body. Because there is no cure and many children are affected by the disease there is a need for alternative therapeutic options that can lead to a cure.

Human mesenchymal stem cells …

A Backing Device Based On An Embedded Stiffener And Retractable Insertion Tool For Thin-Film Cochlear Arrays, Radheshyam Tewari

Dissertations, Master's Theses and Master's Reports - Open

Intracochlear trauma from surgical insertion of bulky electrode arrays and inadequate pitch perception are areas of concern with current hand-assembled commercial cochlear implants. Parylene thin-film arrays with higher electrode densities and lower profiles are a potential solution, but lack rigidity and hence depend on manually fabricated permanently attached polyethylene terephthalate (PET) tubing based bulky backing devices. As a solution, we investigated a new backing device with two sub-systems. The first sub-system is a thin poly(lactic acid) (PLA) stiffener that will be embedded in the parylene array. The second sub-system is an attaching and detaching mechanism, utilizing a poly(N-vinylpyrrolidone)-block-poly(d,l-lactide) (PVP-b-PDLLA) copolymer-based …

Design And Synthesis Of Multifunctional Polymeric Micelles For Gene-Directed Enzyme Prodrug Therapy, Alicia J. Sawdon

Dissertations, Master's Theses and Master's Reports - Open

Gene-directed enzyme prodrug therapy is a form of cancer therapy in which delivery of a gene that encodes an enzyme is able to convert a prodrug, a pharmacologically inactive molecule, into a potent cytotoxin. Currently delivery of gene and prodrug is a two-step process. Here, we propose a one-step method using polymer nanocarriers to deliver prodrug, gene and cytotoxic drug simultaneously to malignant cells. Prodrugs acyclovir, ganciclovir and 5-doxifluridine were used to directly to initiate ring-opening polymerization of epsilon-caprolactone, forming a hydrophobic prodrug-tagged poly(epsilon-caprolactone) which was further grafted with hydrophilic polymers (methoxy poly(ethylene glycol), chitosan or polyethylenemine) to form amphiphilic …

Development Of Confocal Imaging Techniques For Probing Interfacial Dynamics In Microscale, Gas-Liquid, Two-Phase Flow, Joseph E. Hernandez

Dissertations, Master's Theses and Master's Reports - Open

Micro-scale, two-phase flow is found in a variety of devices such as Lab-on-a-chip, bio-chips, micro-heat exchangers, and fuel cells. Knowledge of the fluid behavior near the dynamic gas-liquid interface is required for developing accurate predictive models. Light is distorted near a curved gas-liquid interface preventing accurate measurement of interfacial shape and internal liquid velocities. This research focused on the development of experimental methods designed to isolate and probe dynamic liquid films and measure velocity fields near a moving gas-liquid interface. A high-speed, reflectance, swept-field confocal (RSFC) imaging system was developed for imaging near curved surfaces.

Experimental studies of dynamic gas-liquid …

Use Of An Electrical Impedance Tomography Method To Detect And Track Fractures In A Gelatin Medium, Evan G. Lucas

Dissertations, Master's Theses and Master's Reports - Open

Electrical impedance tomography is applied to the problem of detecting, locating, and tracking fractures in ballistics gelatin. The hardware developed is intended to be physically robust and based on off-the-shelf hardware. Fractures were created in two separate ways: by shooting a .22 caliber bullet into the gelatin and by injecting saline solution into the gelatin. The .22 caliber bullet created an air gap, which was seen as an increase in resistivity. The saline solution created a fluid filled gap, which was seen as a decrease in resistivity. A double linear array was used to take data for each of the …

Scalable Approximation Of Kernel Fuzzy C-Means, Zijian Zhang

Dissertations, Master's Theses and Master's Reports - Open

Virtually every sector of business and industry that uses computing, including financial analysis, search engines, and electronic commerce, incorporate Big Data analysis into their business model. Sophisticated clustering algorithms are popular for deducing the nature of data by assigning labels to unlabeled data. We address two main challenges in Big Data. First, by definition, the volume of Big Data is too large to be loaded into a computer’s memory (this volume changes based on the computer used or available, but there is always a data set that is too large for any computer). Second, in real-time applications, the velocity of …

State-And-Transition Modeling And Adaptive Management: Tools For Future Co-Development Of Madagascar’S Natural Resources And People, Patrick Thomas Spencer

Dissertations, Master's Theses and Master's Reports - Open

Madagascar’s terrestrial and aquatic ecosystems have long supported a unique set of ecological communities, many of whom are endemic to the tropical island. Those same ecosystems have been a source of valuable natural resources to some of the poorest people in the world. Nevertheless, with pride, ingenuity and resourcefulness, the Malagasy people of the southwest coast, being of Vezo identity, subsist with low development fishing techniques aimed at an increasingly threatened host of aquatic seascapes. Mangroves, sea grass bed, and coral reefs of the region are under increased pressure from the general populace for both food provisions and support of …

Thickness Measurement Of Dynamic Thin Liquid Films Generated By Plug-Annular Flow In Non-Wetting Microchannels, David C. Deisenroth

Dissertations, Master's Theses and Master's Reports - Open

Surface tension forces are significant at millimeter length-scales, causing profoundly different flow morphologies in microchannels than in macroscale flows. The existence and morphology of thin liquid films is particularly relevant for predicting performance and operational stability of devices containing microscale two phase flows. Analytical, computational, and experimental methods previously employed in the study of thin liquid films are discussed. Thicknesses before and after a novel film morphology, referred to as a `shock,' are measured with a novel film thickness measurement technique that uses confocal microscopy. Film thicknesses predicted by previous work are compared to experimental results. Methods for increasing the …

Age-Dependent Fragility And Life-Cycle Cost Analysis Of Timber And Steel Distribution Poles Subjected To Hurricanes, Abdullahi M. Salman

Dissertations, Master's Theses and Master's Reports - Open

Power distribution systems are susceptible to extreme damage from natural hazards especially hurricanes. Hurricane winds can knock down distribution poles thereby causing damage to the system and power outages which can result in millions of dollars in lost revenue and restoration costs. Timber has been the dominant material used to support overhead lines in distribution systems. Recently however, utility companies have been searching for a cost-effective alternative to timber poles due to environmental concerns, durability, high cost of maintenance and need for improved aesthetics. Steel has emerged as a viable alternative to timber due to its advantages such as relatively …

Electrocatalytic Processing Of Renewable Biomass-Derived Compounds For Production Of Chemicals, Fuels And Electricity, Le Xin

Dissertations, Master's Theses and Master's Reports - Open

The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with …

Beneficial Reuse Of Locally-Available Waste Materials As Lightweight Aggregate In Lightweight Concrete, Brienna E. Rust

Dissertations, Master's Theses and Master's Reports - Open

This study investigated the physical characteristics of lightweight concrete produced using waste materials as coarse aggregate. The study was inspired by the author’s Peace Corps service in Kilwa, Tanzania. Coconut shell, sisal fiber, and PET plastic were chosen as the test waste products due to their abundance in the area. Two mixes were produced for each waste product and the mix proportions designed for resulting compressive strengths of 3000 and 5000 psi. The proportions were selected based on guidelines for lightweight concrete from the American Concrete Institute. In preparation for mixing, coconut shells were crushed into aggregate no larger than …

Morphology And Mixing State Of Atmospheric Particles: Links To Optical Properties And Cloud Processing, Swarup China

Dissertations, Master's Theses and Master's Reports - Open

Atmospheric particles are ubiquitous in Earth’s atmosphere and impact the environment and the climate while affecting human health and Earth’s radiation balance, and degrading visibility. Atmospheric particles directly affect our planet’s radiation budget by scattering and absorbing solar radiation, and indirectly by interacting with clouds. Single particle morphology (shape, size and internal structure) and mixing state (coating by organic and inorganic material) can significantly influence the particle optical properties as well as various microphysical processes, involving cloud-particle interactions and including heterogeneous ice nucleation and water uptake. Conversely, aerosol cloud processing can affect the morphology and mixing of the particles. For …

Design And Application Of Wireless Passive Magnetoelastic Resonance And Magnetoharmonic Force Sensors, Brandon D. Pereles

Dissertations, Master's Theses and Master's Reports - Open

The objective of the work described in this dissertation is the development of new wireless passive force monitoring platforms for applications in the medical field, specifically monitoring lower limb prosthetics. The developed sensors consist of stress sensitive, magnetically soft amorphous metallic glass materials. The first technology is based on magnetoelastic resonance. Specifically, when exposed to an AC excitation field along with a constant DC bias field, the magnetoelastic material mechanically vibrates, and may reaches resonance if the field frequency matches the mechanical resonant frequency of the material. The presented work illustrates that an applied loading pins portions of the strip, …

Evaluation Of Potential Transload Facility Locations In The Upper Peninsula (Up) Of Michigan, Irfan Rasul

Dissertations, Master's Theses and Master's Reports - Open

Shippers want to improve their transportation efficiency and rail transportation has the potential to provide an economical alternative to trucking, but it also has potential drawbacks. The pressure to optimize transportation supply chain logistics has resulted in growing interest in multimodal alternatives, such as a combination of truck and rail transportation, but the comparison of multimodal and modal alternatives can be complicated.

Shippers in Michigan’s Upper Peninsula (UP) face similar challenges. Adding to the challenge is the distance from major markets and the absence of available facilities for transloading activities. This study reviewed three potential locations for a transload facility …

Density Of Amorphous Carbon By Using Density Functional Theory, Sorayot Chinkanjanarot

Dissertations, Master's Theses and Master's Reports - Open

Amorphous carbon has been investigated for a long time. Since it has the random orientation of carbon atoms, its density depends on the position of each carbon atom. It is important to know the density of amorphous carbon to use it for modeling advance carbon materials in the future. Two methods were used to create the initial structures of amorphous carbon. One is the random placement method by randomly locating 100 carbon atoms in a cubic lattice. Another method is the liquid-quench method by using reactive force field (ReaxFF) to rapidly decrease the system of 100 carbon atoms from the …

Time Lapse Seismic Observations And Effects Of Reservoir Compressibility At Teal South Oil Field, Nayyer Islam

Dissertations, Master's Theses and Master's Reports - Open

One of the original ocean-bottom time-lapse seismic studies was performed at the Teal South oil field in the Gulf of Mexico during the late 1990’s. This work reexamines some aspects of previous work using modern analysis techniques to provide improved quantitative interpretations. Using three-dimensional volume visualization of legacy data and the two phases of post-production time-lapse data, I provide additional insight into the fluid migration pathways and the pressure communication between different reservoirs, separated by faults. This work supports a conclusion from previous studies that production from one reservoir caused regional pressure decline that in turn resulted in liberation of …

Understanding Chassis Inputs From The Rear Suspension Of A Snowmobile, Jamie L. Kleinendorst

Dissertations, Master's Theses and Master's Reports - Open

Today’s snowmobile industry faces great challenges in the field of noise & vibration. The area of main concern is the pass-by noise restriction defined by the Society of Automotive Engineers (SAE) test standard J192, with a maximum sound pressure level of 78 dB(A) being required by many states and national parks. To continue meet or beat this requirement without effecting machine performance, a deeper understanding of the sound transfer paths is required. This thesis examines the transfer paths created by the tunnel, rear suspension, drive shaft, and rubber composite track, with the primary source being suspension input through the ground. …

Out-Of-Step Detection Based On Zubov’S Approximation Boundary Method, Yawei Wei

Dissertations, Master's Theses and Master's Reports - Open

Disturbances in power systems may lead to electromagnetic transient oscillations due to mismatch of mechanical input power and electrical output power. Out-of-step conditions in power system are common after the disturbances where the continuous oscillations do not damp out and the system becomes unstable. Existing out-of-step detection methods are system specific as extensive off-line studies are required for setting of relays. Most of the existing algorithms also require network reduction techniques to apply in multi-machine power systems. To overcome these issues, this research applies Phasor Measurement Unit (PMU) data and Zubov’s approximation stability boundary method, which is a modification of …

Nano-Engineering Of Composite Material Via Reactive Mechanical Alloying/Milling (Rma/M), Edward Andrew Laitila

Dissertations, Master's Theses and Master's Reports - Open

Attempts to strengthen a chromium-modified titanium trialuminide by a combination of grain size refinement and dispersoid strengthening led to a new means to synthesize such materials. This Reactive Mechanical Alloying/Milling process uses in situ reactions between the metallic powders and elements from a process control agent and/or a gaseous environment to assemble a dispersed small hard particle phase within the matrix by a bottom-up approach. In the current research milled powders of the trialuminide alloy along with titanium carbide were produced. The amount of the carbide can be varied widely with simple processing changes and in this case the milling …

Development Of Practical Applications For Reprap Style 3-D Printers In Engineering, Benjamin T. Wittbrodt

Dissertations, Master's Theses and Master's Reports - Open

The current rise in popularity of consumer level 3-D printers introduces a need to understand the application and material property capabilities of the technology. Presented here is data demonstrating the ability for the average U.S. consumer to recuperate the cost of a 3-D printer within one year of ownership. Additionally, using a consumer level 3-D printer, multiple photovoltaic (PV) racking systems were printed and produced with much lower cost compared to commercially available aluminum racking. Additionally, mechanical testing on 3-D printed components showed a temperature dependence on both percent crystallinity and ultimate tensile strength. Conclusions are drawn using the information …

Fabrication Of Drug Eluting Ti Implants For Dental/Orthopedic Applications, Azhang Hamlekhan

Dissertations, Master's Theses and Master's Reports - Open

Titanium and its alloys are typically used for fabrication of dental and orthopedic implants as they possess various desirable properties including biocompatibility and corrosion resistance. In spite of such benefits, titanium implants show lack of osseointegration after surgery in minor cases. The objective of this research has been to modify the surface of titanium alloy for medical applications through increasing surface hydrophilicity and drug loading. Primarily, anodization method is employed for fabrication of nanotubes on titanium surface to act as anchoring cite for cells.

Considering the key role of surface hydrophilicity on cellular attachment to the surface and subsequent biological …

Experimental Setup And Controller Design For An Hcci Engine, Deepak Kothari

Dissertations, Master's Theses and Master's Reports - Open

Homogeneous charged compression ignition (HCCI) is a promising combustion mode for internal combustion (IC) engines. HCCI engines have very low NO_x and soot emission and low fuel consumption compared to traditional engines. The aim of this thesis is divided into two main parts: (1) engine instrumentation with a step towards converting a gasoline turbocharged direct injection (GTDI) engine to an HCCI engine; and (2) developing controller for adjusting the crank angle at 50% mass fuel burn (CA50), exhaust gas temperature T_exh, and indicated mean effective pressure (IMEP) of a single cylinder Ricardo HCCI engine.

The base GTDI …

A Complex-Envelope Fdtd Formulation Using Real-Valued Field-Variables, Qi Liu

Electronic Theses and Dissertations

Use of the complex-envelope (CE) representation of band-pass limited sources and their resulting fields increases the allowable time-step in finite-difference time-domain (FDTD) simulations. The complex envelope representation transforms band-pass limited fields and sources to complex-valued low-pass limited form and Maxwells equations from real-valued partial differential equations (PDEs) to complex-valued PDEs. Previous CE FDTD schemes have used complex valued difference equations in terms of complex valued field quantities to approximate these complex PDEs. This choice requires the use of complex numbers and complex operations in the computer program implementing the solution. An alternative CE FDTD scheme using only real numbers and …