Engineering Commons^™

Production And Characterization Of Supported Palladium Nanoparticles On Multiwalled Carbon Nanotubes By Gamma Irradiation, Jessika Viviana Rojas Marin

Masters Theses

"Carbon nanotubes are being studied for a variety of applications due to their outstanding mechanical, chemical, electrical, and optical properties that make them interesting in different areas. Nowadays, different methods to modify the structure of the nanotubes are being developed in order to expand the application fields of such materials. In this work, palladium nanoparticles were directly produced and supported on multi-walled carbon nanotubes (MWCNT) by gamma irradiation. A solution with a 2:1 water-isopropanol ratio was prepared and mixed with palladium chloride as precursor of palladium ions. Radiolysis of water produces certain species that reduce the ions down to a …

Categorization And Experimental Evaluation Of Anchorage Systems For Fiber-Reinforced Polymer Laminates Bonded To Reinforced Concrete Structures, Stephen V. Grelle

Masters Theses

"While externally-bonded fiber-reinforced polymer (FRP) composites are commonly used for the strengthening of structurally deficient reinforced concrete (RC) members, the topic of anchoring FRP to concrete to achieve higher design strengths has not been addressed. Many innovative systems have been developed to anchor FRP to concrete, but the research involving these anchorage systems is not centralized and is therefore difficult to access. Additionally, systematic testing procedures for evaluating the strength of an anchorage system have not been widely used. To aid in the organization of anchorage system research and facilitate a better understanding of anchorage system behavior, a categorization system …

Quantifying The Carbon Footprint Of Lean Waste, Kristen Donovan Balinski

Masters Theses

"The objective of this paper is to provide a method of quantifying lean wastes in terms of carbon dioxide emissions by using value stream mapping. Lean manufacturing, a process based on waste identification and reduction, is a growing trend in industry and a proven method of lowering costs. The environmental impact of these wastes can be quantified by identifying the metrics associated with them, and using existing reports to convert those metrics into measurements of carbon dioxide. Growing environmental concerns are prompting federal government regulation of greenhouse gas or carbon dioxide emissions, as seen in the American Clean Energy and …

Development And Testing Of Chemically-Based Self-Consolidating Concrete, Mark Daniel Ezzell

Masters Theses

"Self-consolidating concrete (SCC) possesses several characteristics that can benefit the concrete construction industry including accelerated construction, a reduction in labor and equipment, and a reduction in construction noise through eliminating or reducing the need to vibrate the concrete. However, SCC has some potential downsides. These problems can usually be attributed to higher paste content, higher fines content, rounder aggregate, and higher water to cement (w/c) ratios used to increase the flow of the concrete. The goal of this research project was to develop a SCC that had improved material properties through the use of chemical admixtures instead of modifications to …

Integration Of Model-Based Systems Engineering And Virtual Engineering Tools For Detailed Design, Akshay Kande

Masters Theses

"Design and development of a system can be viewed as a process of transferring and transforming data using a set of tools that form the system's development environment. Conversion of the systems engineering data into useful information is one of the prime objectives of the tools used in the process. With complex systems, the objective is further augmented with a need to represent the information in an accessible and comprehensible manner. The importance of representation is easily understood in light of the fact that the stakeholder's ability to make prompt and appropriate decisions is directly related to his understanding of …

Design Of A Current Probe For Measuring Ball-Grid-Array Packaged Devices, Tianqi Li

Masters Theses

"A current probe to measure BGA ball currents via magnetic induction has been designed. The probe is manufactured on a 4 layer flex circuit and has been validated by full wave simulations and measurements. The feature size of the probe is very tiny that it almost pushes the limit of flex-circuit technology. Several critical manufacturing problems were happened, and they have been solved now. The probe allows measuring currents of a 1 mm pitch BGA ball directly. Its operating frequency stretched from tens of MHz up to 3GHz. The BGA probe's mutual inductance is approximately 11 pH, and with amplifiers …

Development Of Hybrid Composite Bipolar Plates For Proton Exchange Membrane Fuel Cells, Nathaniel James Richie

Masters Theses

"Bipolar plates are one of the most expensive components of a PEM fuel cell and by far the heaviest. Bipolar plates are responsible for providing flow fields for reaction gases, acting as current collectors for electrons liberated during the chemical reaction inside the cell, and providing structural support for the fuel cell stack. Current PEM fuel cell bipolar plate technology is built on the use of sintered graphite which is costly and requires time-consuming machining. Furthermore, due to the brittle nature of graphite, plates must be made relatively thick which adds significant weight and volume to larger stacks, such as …

Experimental Study Of The Interaction Between Surfactants And Preformed Particle Gels, Farag Awadh Muhammed

Masters Theses

"Gel and surfactant treatment are two principle methods to reduce water production and enhance oil recovery (EOR). However, either method by itself has limitations that can be avoided by combining the two. Gel treatment can improve sweep efficiency but has little effect on micro-displacement efficiency. Surfactants are mainly used to improve displacement efficiency but have little effect on sweep efficiency. This research sought to investigate whether the combination of gel and surfactant treatments can be used to significantly enhance oil recovery while reducing water production for extremely heterogeneous mature reservoirs. A newer trend in gel treatments is preformed particle gels …

Effect Of Initial Conditions On Molecular Mixing In A High Schmidt-Number Rayleigh-Taylor Mixing Layer, Lakshmi Ayyappa Raghu Mutnuri

Masters Theses

"Characterizing molecular mixing in Rayleigh-Taylor instability (RTI) driven flows where the density and velocity fields are coupled is essential for developing exacting predictive models. Sensitivity of the Rayleigh Taylor mixing layer to initial conditions is a topic that is being explored extensively in interests of accurate turbulent mix model development and its direct consequence in various applications like design of inertial confinement fuel capsule and atmospheric modeling. As part of the current work, an experimental investigation of the effect of initial conditions on molecular mixing in a low Atwood number(~7.5 x 10⁻⁴), high Schmidt number(~1000), RTI driven mixing layer is …

Simulink As A Tool For Modelling Communication Systems, Chaitri Avinash Aroskar

Masters Theses

"Simulink is a graphical tool provided by MathWorks to enable model-based design and simulation. This thesis consists of two papers which take advantage of Simulink features in order to model communication systems.

The first paper employs Simulink to create projects to supplement a purely lecture oriented course: Communication Systems I. The projects cover Linear systems, Analog modulation and Digital modulation concepts in a set of six projects. These projects have been designed based on Gagne's nine events of instruction to enhance their impact on students' learning process. The paper also outlines the advantages of this approach over the conventional programming …

Continuous Monitoring Of Bioactive Glass Conversion Using Optical Biosensors, Prajakta Bhagwat

Masters Theses

"The engineered regeneration of bone is a significant challenge being undertaken to treat conditions such as traumatic casualties, bone cancer, osteoporosis, etc. Advances in hard tissue regrowth may potentially lead to significantly improved lives for millions of people. Bioactive glasses as potential materials in the fabrication of scaffolds for hard tissue regeneration have been studied recently. Bone regrowth requires maintenance of optimal levels of oxygen, glucose, phosphate, calcium, and pH. Current work at Missouri S & T's Center for Bone and Tissue Repair and Restoration focuses on developing optical biosensors to monitor: conversion of bioactive glass to hydroxyapatite, ease of …

Effect Of Nickel On Castability Of Chromium Molybdenum Steel & The Dynamic Fracture Toughness Of Hy-130, Abhilash Dash

Masters Theses

"The fill lengths of Ni alloyed Cr-Mo steels obtained from fluidity studies (Paper 1) varied linearly with superheat. A 5% Ni steel showed a maximum fill length compared to other steels tested. Ni decreased the liquidus, solidus, and dendritic coherency temperature, but it did not have any significant effect on volume fraction (0.27-0.31) of the solid phase at the dendrite coherency point. The filling time obtained experimentally at 150 C⁰ superheat for 5% Ni steel (HY 130) was close to 1.4 s. For similar conditions, the predicted fill time using a Magmasoft model was close to 1.9 s. Modeling results …

Comparison Of Matrix Pencil And Prony Analysis For Estimating Electromechanical Modes In Noisy Signals For Power System Applications, Lisa L. Grant

Masters Theses

"As modern power systems continue to grow and evolve, accurate system stability analysis and oscillation control become increasingly important to guarantee system security. Network instability due to power system oscillations caused by the natural modes of the system is becoming a common occurrence. Modal analysis techniques can estimate the eigenvalues of large nonlinear systems from their dynamics responses. The extracted modal information can be applied to detect low frequency oscillations and assess stability margins for power system monitoring and preventive control. Modal information is also useful for low-frequency oscillation damping controller design. This thesis examines two techniques for modal identification …

Femtosecond And Nanosecond Laser Fabricated Substrate For Surface-Enhanced Raman Scattering, Adam Hamdorf

Masters Theses

"Surface-enhanced Raman scattering has many applications to chemical science, and shows great promise in the medical field because of its ability to provide "molecular fingerprinting" of probe molecules, whereby a material can be identified and potentially quantified. This is done by enhancing the normally weak Raman spectrum by many orders of magnitude with the use of fabricated substrates. It is therefore desirable to produce repeatable substrates with high enhancement factors for identification and quantification of samples. This thesis introduces a new method for generating such a substrate. By using femtosecond laser machining, gold sputtering, and nanosecond laser annealing, gold nanoparticles …

Creating A Sustainable Transportation Workforce: Identifying Skills, Abilities And Knowledge For Future Transportation Workforce, Sandhya Gopalakrishnan

Masters Theses

"The recruitment and retention of a transportation workforce capable of adapting to the requirements of emerging sustainable technologies is an important concern for engineering managers in transportation. Although there is an increasing demand for transportation professionals to fill positions stemming from retirement or created by innovations in sustainable transportation systems, the supply is decreasing. The objective of this research was to fill the gap between the supply and demand of skilled workforce by presenting a life-cycle framework for recruiting and retaining the transportation workforce as part of succession planning efforts funded by the U.S. Department of Transportation's Transportation Education Development …

Selective Laser Sintering Of 13-93 Bioactive Glass, Krishna C. R. Kolan

Masters Theses

"Bioactive glasses are promising materials for bone scaffolds due to their ability to assist in tissue regeneration. When implanted in vivo, bioactive glasses can convert to hydroxyapatite, the main mineral constituent of human bone and form a strong bond with the surrounding tissues, thus providing an advantage over polymer scaffold materials. Bone scaffold fabrication using additive manufacturing techniques like selective laser sintering (SLS) provide control over pore interconnectivity during the fabrication of scaffold, which helps in mimicking human trabecular bone. 13-93 glass, a third-generation bioactive material designed to accelerate the body's natural ability to heal itself, was used in …

Development Of A Graphical User Interface For The Study Of Parallel-Connected Solar Arrays, Nisha Nagarajan

Masters Theses

"For any solar array it is necessary to be able to harness the maximum possible power from it. A new technology is proposed to improve the efficiency of solar arrays and harness maximum potential power as well by connecting the solar panels in parallel. This thesis describes the development of a graphical user interface for the evaluation of this parallel-connected solar array technology and to compare different scenarios for solar arrays to predict the potential power output to decide the best configuration for an application. This is done via several computations and analysis of field data. The first paper describes …

Economic Evaluation Of Sustainable Strategies For The Transportation Sector, Yaqin Lin

Masters Theses

"Sustainable strategies are drawing growing attention as global environmental challenges increase concerns over energy consumption. As one of the most intensive consumers of energy, the transportation sector has a particular need to go green. Implementing alternative energy sources and applying advanced energy efficient technologies are two major approaches to achieve sustainability. Much work thus far used cost-effectiveness as an important criterion for assessing the practicability of sustainable strategies. However, few studies have evaluated such strategies systematically. This thesis has developed a framework of cost-effectiveness analysis to assess sustainability strategies. The framework summarizes the various effects of five representative alternative energy …

Experimental Investigation Of Cutting Forces, Temperature And Surface Roughness In End-Milling Of Hastelloy C-2000, Ryan Matthews

Masters Theses

"This thesis presents the results of experimental investigation of the effects of cutting parameters (spindle speed, feed per tooth, axial depth of cut and radial depth of cut) on the three components of cutting forces (F_x, F_y, F_z), workpiece temperature and surface roughness in end-milling of Hastelloy C-2000 alloy using design of experiments (DOE) and response surface methodology (RSM). End-milling experiments were conducted using 0.5 inch diameter end-mill on Cincinnati Milacron Sabre 750 vertical machining center using water based flood coolant. An inscribed central composite design of experiment was used to study the four …

Fabrication Of Sers Active Nanostructures By Femtosecond Laser Micromachining, Matthew Aaron Olson

Masters Theses

"This work investigated the surface-enhanced Raman scattering (SERS) enhancement of gold nanoparticles on femtosecond laser created nanostructures on a silicon wafer. The goal was to use the nanostructures to assemble the nanoparticles into three-dimensional aggregates and compare these enhancements to those of two dimensional aggregates. The SERS enhancement generated by the three-dimensional structures was on average 5 x 10⁴ with a high enhancement of 1.2 x 10⁵. The magnitude of this enhancement was on par with previous experiments that tested SERS enhancements on gold nanoparticles, but it did not show any significant enhancement caused by the three-dimensional nature of the …

Electrodeposition Of Metallic Gas Diffusion Layers For Use In Pem Fuel Cells, Gargi Tandra

Masters Theses

"This work developed a novel method of using Electrodeposition techniques to fabricate metallic gas diffusion layers (GDLs) for application in proton exchange membrane fuel cells. These GDLs improve the electrical and thermal conductivity of the fuel cells, and their straight, noncircular pores remove water efficiently. The Electrodeposition technique used here relies on a sacrificial copper anode and an aluminum sheet 50 µm thick acts as a cathode. Unlike the other laboratory based methods available for the fabrication of metallic GDLs, this method is simple and cost effective. With controlled deposition parameters and a chemical lift-off process that corrodes the aluminum …

Development Of Virtual Engineering Simulation For Lean Education, Akalpit Kiran Gadre

Masters Theses

"Global competition and customer demands are pressing modern industry operations to become leaner. The race among the global corporations to "go lean" demands engineers with an in-depth understanding of lean philosophies. An overview of current methods for teaching lean shows that they include small scale hands-on projects, presentations, and guest lectures. There is a need to incorporate a more immersive virtual simulation to further inspire students. Many lean simulation games are available in the market; however, they lack simplicity, ability to store the results, and modeling power.

The goal of this research is to develop a virtual simulation platform, enabling …

Memristor Based Lookup Table - Novel Testing And Reconfiguration Techniques, Veeresh Anilkumar Hongal

Masters Theses

"Nanotechnology is soon predicted to replace the CMOS technology, as current CMOS lithographic techniques will become void for complex IC designs with smaller feature size, and are hence incapable of keeping up with Moore's law. The devices in nanotechnology are fabricated using bottom up self-assembly. Memristor is one promising nanotech device which can replace the transistor used as a switch or memory device as it is just half the size and uses only fraction of the energy. This work considers Memristor Look Up Table (MLUT) design, which is a building block for asynchronous FPGAs built with memristors. In spite of …

Risk Assessment For Conceptual Design Of Hydrokinetic Turbines, Praveen Kailkere Srinivas

Masters Theses

"Hydrokinetic energy is a relatively new concept in the field of renewable energy. The rotor of the turbine, immersed in water, uses the velocity from the flowing water to generate power. Thus the hydrokinetic turbines are also known as zero head turbines. These turbines can be installed in rivers, oceans and sea beds. The design of these systems depends on the site conditions, installation and maintenance costs. Since this technology has not been assessed for its potential power producing capabilities, not much research has been done in order to harness this form of renewable energy and to study the impact …

Optimized Testing And Logic Mapping Methodology For Caen-Based Nano-Circuits, Sambhav Kundaikar

Masters Theses

"Nanotechnology has been shown to have the potential to replace the existing CMOS technology in the race to maintain the Moore's Law increases in IC complexity. This work considers the Chemically Assembled Electronic Nanotechnology (CAEN), which fabricates nanofabric using a low cost self-assembly and self-alignment chemical process and provides very high density. However, the main disadvantage of this technology is the inherently high defect rate that hinders the efforts to commercialize such systems. Existing testing and design techniques, for example for FPGAs, are ill suited since they typically assume vary low defect rates.

This thesis is comprised of two papers. …

Mesh Optimization Of Finite Element Models Of Wellbore Stress Analysis, Ming-Yen Lee

Masters Theses

"Numerical modeling methods such as the widely used finite element method provide an excellent opportunity to analyze the wellbore state of stress for a variety of applications such as wellbore integrity, wellbore design or hydraulic fracturing. However, numerical modeling methods introduce errors by nature and may not precisely match the analytical solution if the meshing of the numerical model is not carefully taken care of. This study presents a parametric study of the meshing parameters mesh density, element type, and model size for 2-dimensional and 3-dimensional vertical wellbore models under three different types of boundary conditions, and a guideline for …

Development Of Virtual Cnc Machine Tools And Web-Based Machining Process Simulation: Mechanistic Cutting Force Models And Determination Of Specific Force Coefficients In Helical End Milling, Vinay Rao Talekar

Masters Theses

"This thesis presents the results of the investigations of mechanistic modeling and simulation of cutting forces in high speed end milling of titanium alloy, Ti-6Al-4V, and the determination of specific cutting and edge force coefficients for carbide bull-nose helical end-mill. A generalized mathematical model representing the outer geometry of an end-mill and the cutter edge geometry is presented. Mechanistic cutting force models have been developed for a general helical end-mill and modeled specifically for a bullnose helical end-mill. A MATLAB code for the mechanistic cutting force models have been developed for the simulation of cutting force components in end milling …

A Comparison Of Bootstrap, Binomial Inference, And Monte Carlo Methods For Demand Distribution Modeling, Swithin Samuel Razu

Masters Theses

"Analysis of customer preferences is one of the most important tasks in new product development. How customers come to appreciate and decide to purchase a new product impacts market share and, therefore, the success of the new product. Unfortunately, when designers select a product concept early in the product development process, the "true" customer preferences and therefore, market share of the new product is unknown. Conjoint analysis is a statistical methodology that has been used to forecast the market share of a product concept from customer preference survey data. Although conjoint analysis has been increasingly incorporated in design research as …

Electron Transport Through Two Irreducibly-Coupled Aharonov-Bohm Rings With Applications To Nanostructure Quantum Computing Circuits, Casey Andrew Cain

Masters Theses

"A thorough investigation was conducted into the six fundamental classes of two coupled Aharonov-Bohm rings that share a finite center common path, when the phase of the electron wave function was modulated by two distinct magnetic fluxes. The coupling is similar to two coupled atoms. The behavior of charge accumulation along the center common path or equivalently the bonding and anti-bonding of the two rings can be achieved as the two applied fluxes are varied. Thus when three external terminals are connected to such coupled rings, the behavior of the electron transport is divided into several classes depending on the …

Crack Formation In Investment Casting Ceramic Shells, W. A. Everhart

Masters Theses

"This thesis is a collection of papers that discuss shell cracking in investment casting during pattern removal. The application of rigid polymeric foam for large investment casting patterns with complex geometries can improve the dimensional tolerances and the surface quality of the casting. However, these pattern materials have a tendency to promote crack formation in investment casting shells during pattern removal by firing.

The first two papers discuss the factors affecting shell cracking and methods to prevent it. Experimental methods were combined with finite element modeling to predict stress in the shell. A 3D nonlinear finite element model was developed …