Digital Commons Network^™

Application Of Statcom For Improved Dynamic Performance Of Wind Farms In A Power Grid, Aditya P. Jayam

Masters Theses

"This thesis investigates the use of a Static Synchronous Compensator (STATCOM) along with wind farms for the purpose of stabilizing the grid voltage after grid-side disturbances such as a three phase short circuit fault, temporary trip of a wind turbine and sudden load changes. The strategy focuses on a fundamental grid operational requirement to maintain proper voltages at the point of common coupling by regulating voltage. The DC voltage at individual wind turbine (WT) inverters is also stabilized to facilitate continuous operation of wind turbines during disturbances"--Abstract, page iii.

Sensitivity Analysis Of Relative Worth In Empirical And Simulation-Based Qfd Matrices, Robins Mathai Kalapurackal

Masters Theses

"Quality Function Deployment (QFD) is one of the most popular design tools used in product development. One of the objectives of QFD is to map customer requirements to product requirements and calculate their relative worth. A product requirement with a large relative worth indicates that it is an important product requirement in satisfying customer requirements. QFD applications use various rating scales in quantifying the degree of mapping from customer requirements to product requirements and various worth calculation methods to calculate the relative worth. The purpose of this paper is to study the sensitivity of relative worth when different rating scales …

Sorting Automated Concept Generator Results Based On Manufacture And Assembly Concerns, Kerry Ryan Poppa

Masters Theses

"Early in the design process, it is desirable to produce a large number of potential solutions. Completely exploring a problem's solution space is an unreasonable expectation for an unaided designer or design team. Computational tools have emerged to help designers more fully explore possible solutions. These automated concept generators use knowledge from existing designs and the desired functionality of the new product to suggest solutions. Existing automated concept generation methods produce many candidate solutions, but produce unmanageably large sets of solutions. Techniques are needed to organize the set of concepts into smaller groups, more easily parsed by the human designer. …

Autothermal Non-Catalytic Reformation Of Jet Fuel In A Supercritical Water Medium, Jason W. Picou

Masters Theses

"The non-catalytic reformation of jet fuel using supercritical water was studied in a specially designed 0.4-L Haynes Alloy 230 tubular reactor. Experiments were performed at a constant pressure of 24.1 MPa, a temperature of 770°C, and at a constant water-to fuel ratio of fifteen-to-one by mass with various space times and oxygen flow rates. The experiments were conducted with and without air flow so as to examine the effects of the concurrent partial oxidation on the overall reformation process. The reactor effluent gas consisted of hydrogen, nitrogen, carbon dioxide, carbon monoxide, methane and ethane. Increasing space time increases the extent …

Approaches To Learning In A Classroom Environment: Observational & Experiential, Raj Kanwar Singh

Masters Theses

"Accreditation Board for Engineering and Technology (ABET) has established a set of criteria that requires engineering graduates to be able to effectively communicate, work in teams with ethics and professionalism understanding the contemporary issues. There are different approaches for teaching and learning these skills, two of which are discussed in this thesis. The intention of this research is to understand the impact of observational and experiential learning on team and individual performance"--Abstract, page iv.

Synthesis Of Iron Oxide Nanoparticles In A Counterflow Diffusion Flame Reactor, Hector Enrique Ruiz

Masters Theses

"A Counterflow Diffusion Flame (CDF) reactor was used to produce iron oxide nanoparticles. The experimental work was performed to study synthesis conditions and characterize the iron oxide nanoparticles. The parameters studied are those that control the flame structure, namely, gas flow rates and vacuum; other parameters include the precursor volume flow rate, and the relative location and temperature of the collecting probe inside the flame. Hexagonal nanoparticles were the most commonly observed shape. Hexagonal-shaped nanoparticles are mainly formed under stoichiometric conditions and with a high temperature profile in the flame. Cubic nanoparticles were also observed. The main parameter for the …

Wireless Mote-Based In-Process Diagnostics Using Hand-Held Tools In Network Enabled Manufacturing Environments, Reghu Anguswamy

Masters Theses

"When complex manufacturing systems are considered, post process inspection can be a very time consuming and costly. In addition, no inspection data is typically collected unless a major problem is encountered. Real-time monitoring of the manufacturing processes and verification of its product quality are two important factors to reduce the manufacturing lead time and to ensure safety and quality.

In this thesis, a diagnostics and root-cause analysis scheme with a single channel wireless routing protocol for real-time monitoring of process quality of pull-type fastening operations is first presented. The overall architecture has been implemented on a Huck45 pull-type tool, which …

Application Of Multi-Modal Fusion Techniques For Corrosion Detection And Characterization In Aging Aircraft Components, Soumya De

Masters Theses

"The United States Air Force (USAF) recently estimated that corrosion maintenance costs exceed $800M per year. Given this, it is desirable to reduce the amount of "find it-fix it" corrosion maintenance activities. One method is to introduce a damage tolerance approach for corrosion detection. In order for this to become a reality, a comprehensive snapshot of corrosion present must be generated.

This thesis presents a data fusion process to perform uni- and multi-modal nondestructive testing and evaluation of corrosion under paint and in lap joints for volumetric characterization. The process for analyzing a given structure includes: 1) the acquisition of …

Elevated Temperature Behavior Of A Magnesium Based Bulk Metallic Glass, Neal C. Ross

Masters Theses

"Bulk metallic glasses are a new material set that possess interesting and exceptional engineering properties. Their study has been a major focus of research in metallurgy since the early 1990s, and recently their properties have led to application in specialized applications. Limitations including material cost, maximum attainable cast diameters, and high density have prevented the widespread use of these materials. In particular, the high density of most bulk metallic glasses has significantly reduced their appeal to the aerospace community. In an effort to overcome this, research is being performed on producing lower density glass forming systems based on magnesium and …

Modeling Kinetics Of Hydrolysis Of Three Pesticides In Laboratory Waters, Michelle Kim Marincel

Masters Theses

"Pesticides and pesticide degradates found in drinking water sources are of particular concern to human health. When treated and disinfected at a drinking water plant, pesticides etridiazole, metribuzin, and diazinon undergo many treatment processes including lime softening, where the water pH is raised to 10 for calcium removal or 11 for magnesium removal. This thesis focuses on modeling the kinetics of hydrolysis of three pesticides that have the potential to undergo hydrolysis in drinking water plants. Linearly and non-linearly regressed first order and non-linearly regressed second order models were applied to the experimental data and compared to limited literature values. …

The Carbonatite-Hosted Apatite Deposit Of Jacupiranga, Se Brazil: Styles Of Mineralization, Ore Characterization And Association With Mineral Processing, Paula Regina Alves

Masters Theses

"The carbonatite-hosted apatite deposit of Jacupiranga is located in southeastern Brazil. The major styles of apatite mineralization are veins or veinlets, small pods or patches, disseminated apatite, and massive aggregates (locally). The concentration of apatite involves grinding of the carbonatite, removal of magnetite with a magnet drum, size classification with cyclones, and flotation to suppress carbonates and collect apatite. Samples of carbonatite were collected from more recent exposures of the mine and drill holes. This study utilized a variety of microscopy methods, namely transmitted and reflected light, cathodoluminescence (CL), and scanning electron microscopy (with wavelength-dispersive spectrometers for mineral compositions)"--Abstract, page …

A Separation Criterion And Non-Intrusive Thickness Measurement Technique For Shear-Driven Films, Mark A. Friedrich

Masters Theses

"The behavior of a shear-driven thin liquid film at a sharp expanding corner is of interest in many engineering applications. However, details of the interaction between inertial, surface tension, and gravitational forces at the corner that result in partial or complete separation of the film from the surface are not clear. The focus of this study was to develop a criterion to predict the onset of shear-driven film separation from the surface at an expanding corner as well as to develop a film thickness measurement technique that could be used to obtain an average film thickness for input into the …

Application Of Product Family Design For Engineered Systems In Changing Market Space, Mohit Goswami

Masters Theses

"The focus of this paper is on the design of an engineered system for a changing market space. Due to the dynamic nature of the customer requirements, the specification of product offerings in a particular market may change. Manufacturers need to strategically design their product portfolio in such a way that their profitability is maximized, while deploying the right number of platforms necessary for deriving product variants. Depending on the system architecture, subsystems can be classified into one of the two types: scalar subsystems and modular subsystems. Each subsystem is defined by various parameters, performance criteria, and physical compatibility constraints. …

Defect-Tolerance And Testing For Configurable Nano-Crossbars, Mandar V. Joshi

Masters Theses

"Moore's Law speculated a trend in computation technology in terms of number of transistors per unit area that would double roughly every two years. Even after 40 years of this prediction, current technologies have been following it successfully. There are however, certain physical limitations of current CMOS that would result in fundamental obstructions to continuation of Moore's Law. Although there is a debate amongst experts on how much time it would take for this to happen, it is certain that some entirely new paradigms for semiconductor electronics would be needed to replace CMOS and to delay the end of Moore's …

Fabrication Of Soy Oil Epoxy Resin Based Composites, Vinay Prabhakar Pai

Masters Theses

"A renewable resource derived epoxidized ester - Epoxidized Allyl Soyate (EAS) yields a versatile epoxy resin system that can be used in pure form combination with bis-phenol epoxy systems to obtain high strength composite materials. EAS containing composites materials exhibit higher toughness and impact resistance than the traditional bis-phenol epoxy composites. These resin systems were found to be compatible with different fibers and screens such as glass fibers, glass mats, carbon fibers and metallic wire screens including those obtained from an automobile tire recycling process. The materials were tested for mechanical properties including tensile and flexure strengths. The highest tensile …

Business Risk In Early Design: An Approach, Rahul Basavaraj Patil

Masters Theses

"The Business Risk in Early Design (B-RED) method is a tool used to determine the potential risks in business, in the early business development stages. In order to launch a successful business in today's competitive market environment, the business should equip itself to face the risks involved in business. If the potential risks are identified even before the launch of the business, then there is an opportunity to avert risks with little or no impact to the budget and schedule. The B-RED method presented in this thesis helps entrepreneurs and people with little or no experience in business to identify …

Adaptive Modulation For Cognitive Radios, Gaurav Sharma

Masters Theses

"This thesis examines the benefits of using adaptive modulation in terms of spectral efficiency and probability of bit error for cognitive radio networks. In channels that fluctuate dynamically over time, systems that are based upon the conventional methods of fixed modulation formats do not perform well. Adaptive modulation provides many parameters that can be adjusted relative to the channel fading, including data rate, transmit power, instantaneous BER, symbol rate, and channel code rate or scheme. In this thesis, a systematic study on the increase in spectral efficiency obtained by optimally varying combinations of the modulation formats for a cognitive radio …

Formulating Hedging Strategies For Financial Risk Mitigation In Competitive U.S. Electricity Markets, Karthik Viswanathan

Masters Theses

"The challenges currently facing participants in the competitive electricity markets are unique and staggering: unprecedented price volatility, fluctuations in the demand, a lack of historical market data on which to test the new modeling approaches, increased competition and continuously changing regulatory structure...Electricity plant owners and purchasers of electricity may benefit from various techniques to manage price volatility. For electricity, however, no futures market is actively traded. The electricity forward market in NYMEX is in its nascent stage and is low in liquidity. Producers and purchasers of electricity may find cross-hedging electricity with natural gas futures contracts to be effective in …

Fabrication Of Long-Period Fiber Gratings By Co₂ Laser Irradiation For High Temperature Applications, Tao Wei

Masters Theses

"Long period fiber gratings (LPFG) have unique advantages such as small insertion loss, low retro-reflection, good sensory property and low cost fabrication. LPFGs have found many applications in optical fiber communications as well as in optical fiber sensors. Recently, high-performance LPFGs have been successfully fabricated by CO₂ laser irradiations. The unique thermal stability enables many potential sensing applications in high temperature environments. In this thesis...two chemical sensing applications of LPFG were demonstrated. In the first one, the ambient refractive index sensing ability of bare LPFG was examined. The experimental data showed a good agreement with the simulation results. In the …

Laboratory Analysis Of Small Strain Moduli In Compacted Silts, David M. Weidinger

Masters Theses

"Soil compaction quality control accounts for a significant portion of geotechnical practice. Often the performance of a roadway can be directly linked to the quality of the compacted subgrade. A poor subgrade can result in weak areas in the road causing excessive deflections at the surface, ultimately leading to a pot hole or uneven surface and an unpleasant ride for the travelers. Vehicles passing over a section of highway causes small strains in the founding soil. These strains accumulate over time. A better understanding of how the compacted soil responds at small strains could shed light on improving the quality …

Numerical Study Of Energy Utilization In Nozzle/Plume Flow-Fields Of High-Speed Air-Breathing Vehicles, Althea Grace Wilson

Masters Theses

"Focused local energy deposition in both internal and external flow-fields associated with high-speed aerospace vehicles can provide many system level benefits. This study specifically analyzes the effects of targeted (local) energization of the flow in the nozzle and afterbody flow-field regions of a hypersonic lifting body configuration. Benefits are shown to include the generation of a favorable vehicle pitching moment (nose-down) increment associated with such energy deposition and a reduced local and overall thermal load in both combustor and nozzle for all cases examined. These results have been obtained by modeling the nozzle/afterbody region of a simple generic 2-D wave-rider/lifting …

Analysis Of Access-To-Space Missions Utilizing On-Board Energy Management And Entropic Analysis, Tyler Winter

Masters Theses

"The overall objective of this study is the thermodynamically consistent quantification of second-law and performance losses for vehicle configurations implemented or suggested for access-to-space missions and the development of the relationships between the mission entropy generation and overall mission performance. The detailed theory which allows thermodynamically rigorous loss accounting (entropy generation and direct relationship to vehicle performance) is developed and discussed for aerospace vehicles. A full vehicle trajectory code utilizing simplified models for multi-stage rockets and air-breathing propulsion systems is developed and validated specifically for use as a testbed for second law-based theory and concepts. Results are shown in which …

Experimental Validation Of An Integrated Frp And Visco-Elastic Hardening, Damping, And Wave-Modulating System For Blast Resistance Enhancement Of Rc Columns, Brian Henry Wood

Masters Theses

"In today's society, terrorist attacks and accidental explosions pose a major threat to critical infrastructure. Vulnerable to blast loading, structures must be rehabilitated to ensure structural stability and protect human life. The goal of this study is to develop and validate a sandwich composite technology for column retrofitting. The new technology consists of an inner fiber reinforced polymer (FRP) sheet, an outer FRP sheet, and a visco-elastic (VE) layer sandwiched between the two FRP sheets. The inner FRP sheet is wrapped around an existing column for confinement, while the outer FRP sheet is for anchoring of the VE layer into …

Quantifying The Desired Degree Of Supply Chain Flexibility, Poorna Marappa

Masters Theses

"The dynamic nature of today's market drives the need for flexibility in supply chains. The ever-growing need for and importance of flexibility in supply chains has motivated researchers to develop frameworks to achieve supply chain flexibility. Much of the research on supply chain flexibility focuses on drivers of the need for flexibility and classification of supply chain flexibility. Existing frameworks for determining the desired degree of flexibility in supply chains give an overview methodology; however, a comprehensive framework is absent. This research proposes a comprehensive framework to quantify the desired degree of flexibility in supply chains and accordingly determine its …

Removal Of Heavy Metals From Electroplating Wastewater Using Rice Husk And Coconut Coir, Frency Mathew

Masters Theses

"Heavy metal toxicity due to industrial wastewater has been a threat to the environment for the past many decades, especially in the developing countries such as India, China and Thailand where cost effectiveness of the removal process is a major factor. In this research, the effectiveness of two natural adsorbents, rice husk (RH) and coconut coir (CC), which are cheaply available in these countries for the removal of heavy metals from electroplating wastewaters were studied"--Abstract, page iii.

Methodology And Process To Accompany A Virtual Geotechnical Database For The St. Louis Metropolitan Area, Katherine Leigh Onstad

Masters Theses

"The St. Louis metropolitan (STL) area, which spans Missouri and Illinois, currently has no overarching organization of geospatial data (geodata). The two states have their own geodata, using their own individual standards. The development of a virtual geotechnical database (VGDB) encompassing the entire STL area on both sides of the Mississippi River is a solution to the data sharing and standardization problem of this area. The VGDB integrates geodata from disparate sources into a geographic information systems (GIS) database accessible via the internet. The creation of the STL area VGDB consisted of three parts: 1) compiling the geodata; 2) formatting …

An Economic Incentive Based Routing Protocol Incorporating Quality Of Service For Mobile Peer-To-Peer Networks, Anil Jade

Masters Theses

"Economic incentive models are becoming increasingly popular in Mobile Peer to Peer Networks (M-P2P). These models entice node participation to combat free riding and to effectively manage constraint resources in the network. Due to the dynamic topology of the M-P2P network, the connections between the peers become unpredictable and therefore, reliable routing becomes important. Many routing protocols proposed earlier (such as DSR, AODV) are based on best effort data traffic policy, such as the shortest route selection (hop minimization). Using economic models to find a cost effective optimal route from the source to the destination, while considering Quality of Service …

Universal Electric And Magnetic Fields Analyzer System, Yong Cheh Ho

Masters Theses

"Near-field probing is often used to measure the electric and magnetic fields above a printed circuit board (PCB) or integrated circuits (IC) chip in order to identify the sources and coupling paths of an electromagnetic interference (EMI) problem.

A wideband universal field analyzer was designed, built and tested in this thesis. The system is able to provide fast field scanning over a wide frequency range in lieu of its capabilities to measure multiple field components using a single probe design. Central to the system operation is the phase-shifting concept that provides wideband and wide- range phase-shifting.

The complete universal field …

Obscurant Oil Characterization Produced Through Vaporization By Exhaust Gas Of Mini-Jet Turbine Engine, Hossein Daniel Bahaghighat

Masters Theses

"Obscurants have been used for centuries to conceal and protect military assets from direct enemy attack, or as a signal between units. Obscurants still play a significant role in protecting soldiers on the battlefield. This research was geared towards development of highly efficient man portable obscurant generation system to demonstrate its use with biogenic oils as the obscurants. The research reported in the thesis was directed evaluating the performance of a mini-jet based generator in the laboratory and field with two different obscurant oils, Fog Oil (FO) the oil used by the US Army at present and potential replacement oil …

Polymer Reinforced Aerogels And Composites A. Polyimide Crosslinked Aerogels B. Silica-Polymethylmethacrylate Composites, Vishal U. Patil

Masters Theses

"Crosslinking of aerogels is a promising approach to combine the advantages of inorganic and polymeric materials. In the present study, two types of polyimide-silica hybrid aerogels, APTES-BTDA-MDA (mol ratio: 2:2:1) and APTES-BTDA-MDA (mol ratio: 2:3:2), were synthesized using a sol-gel process followed by heating in order to imidize the polyamic acid that is formed quickly and is covalently bonded to silica. The hybrid aerogels were made using 3-aminopropyltriethoxysilane (APTES) endcapped polyamic acids and tetramethoxysilane (TMOS) as precursors. Polyimide crosslinked aerogels were characterized by TGA, SEM, FT-IR, BET, solid state NMR and gas pycnometry. These hybrid aerogels exhibit high thermal stability …