Engineering Commons^™

Application Of Embedded Frequency Selective Surfaces For Structural Health Monitoring, Dustin Franklin Pieper

Masters Theses

"This thesis proposes the use of Frequency Selective Surfaces (FSSs) as an embedded structural health monitoring (SHM) sensor. FSSs are periodic arrays of conductive elements that filter certain frequencies of incident electromagnetic radiation. The behavior of this filter is heavily dependent on the geometry of the FSS and local environment. Therefore, by monitoring how this filtering response changes when the geometric or environmental changes take place, information about those changes may be determined. In previous works, FSS-based sensing has shown promise for sensing normal strain (a stretching or compressing geometrical deformation). This concept is extended in this thesis by investigating …

A Cost Benefit Analysis Of Sst Based Volt-Var Control, Guruprasad Ramani

Masters Theses

"The overall objective of this thesis work is to improve system power quality with the help of solid state transformers (SSTs). Two methods to improve the system power quality are explored: a) achieving a unity power factor at all the load buses, and b) improving the system voltage profile to meet a desired voltage regulation requirement of 0.95

Numerical Analysis Of Flexural Slip During Viscoelastic Buckle Folding, Davi Rodrigues Damasceno

Masters Theses

"Flexural slip is considered to be an important folding mechanism contributing in the development of different folds such as chevron, and kink-band buckle folds. Various filed studies have provided a general conceptual and qualitative understanding of flexural slip. However, quantitative evidence of the importance of the flexural slip mechanism during fold evolution is sparse, as the actual amount of surface parallel displacement, and timing, is difficult to measure accurately, due to the lack of suitable strain markers.

In this study 2D finite element analysis is used to overcome these disadvantages and to simulate flexural slip during viscoelastic buckle folding. Variations …

A Feasibility Study Of A Nuclear Power Plant With No Moving Parts, Jonathan Mark Schattke

Masters Theses

"In a nuclear reactor design, every moving part in a system is considered a failure point. In this study, a proposal is made for designing a nuclear reactor that has no moving parts by coupling an accelerator driven core (removing control system moving parts) to a magnetohydrodynamic generator (removing power generation moving parts) using mercury coolant (removing pumping system moving parts). Further safety is realized by using a subcritical core, where the core is never able to sustain a chain reaction on its own, obviating many safety systems. The design is verified with a Monte Carlo simulation "--Abstract, page iii.

Thermal Characterization Of Phase Change Materials For Thermal Energy Storage, Rami Mohammad Reda Saeed

Masters Theses

"The study provides a valuable and useful database for Phase Change Materials (PCMs) for Thermal Energy Storage (TES) applications. Only a few existing studies have provided an overall investigation of thermophysical properties of PCMs in this detailed manner. Several organic PCMs, namely Myristic acid, Capric Acid, Lauryl Alcohol, Palmitic acid and Lauric acid, have been characterized after being carefully selected to cover wide range of TES applications. Insights and information gained from this work will be applied toward the design and modelling of many low temperature thermal energy storage applications. The study experimentally investigated uncertainty of thermal characterization of PCMs …

Evaluation Of Ultra-High Performance Concrete (Uhpc) In Joints Of Bridge Girders, Saipavan Rallabhandhi

Masters Theses

"Joints are often considered as the weak link in a structure and often deterioration of the structure initiates from the joints. Joints transfer the stresses from super-structure to sub-structure and in this process are subjected to large transfer stresses. Not much attention is given to the design of joints as they are positioned in low moment regions and typically a 4 to 6 ksi (28 to 41 MPa) concrete is used to fill the joints. One of the solution to this problem is Ultra-high performance concrete (UHPC). In the recent past significant research has been done to use UHPC in …

Data Analysis Of Surfactant-Induced Wettability Alteration In Carbonate Reservoirs, Hao Sun

Masters Theses

"Most carbonate formations prove to be oil-wet due to oil aging effect. Therefore it is essential to employ wettability alteration methods for a more effective enhanced oil recovery process. It is confirmed by researchers that surfactant treatment has positive effects on wettability alteration of carbonate rock, from strong oil-wet to intermediate wet or to even weak water-wet. A number of experiments have the same conclusion and yet, a systematic screening guide development with the support of sufficient data analysis is lacking.

This study involves screening guide development for surfactant-induced wettability alteration method. 199 experiments collected from published literatures are analyzed …

Automated Channel Emulator Based On Mems Switch And Improvement Of Signal Transition, Jingdong Sun

Masters Theses

"Channel Emulator, which is widely used in communication system development, is an instrument that emulates the real-world signal propagation environment between transmitter and. [sic] To overcome the disadvantages of traditional channel emulator, we propose a novel structure of the automated channel emulator in Section 1, which can be controlled by software and integrated into auto-testing system. MEMS switch, with good RF performance, is used to connect and isolate multiple channels.

In Section 2, we divide the whole channel emulator system into Channel, Support, and Controller Board, and provide detailed design procedures with critical parameters of each board. The well-designed high …

Esd Related Soft Error Detection And Root Cause Analysis, Suyu Yang

Masters Theses

"In this article, several methods are outlined for detecting functional changes in an IC due to external interference such as ESD or EMI. The goal is to provide diagnostic tools for detection of potential soft failure susceptibilities of complex systems during the hardware design stage without the aid of any complex software. After the soft errors are found, circuit modeling techniques are used to characterize the DUT. By running the circuit model, the soft error threshold can be predicted and the circuit model can be used to evaluate the performance of other ESD protection methods. In the end several methods …

3d Seismic Structural And Stratigraphic Interpretation Of The Tui-3d Field, Taranaki Basin, New Zealand, Gorkem Yagci

Masters Theses

"Identifying seismic structures and stratigraphy are important for exploration of hydrocarbons. The purpose of this study is to discover seismic structural and stratigraphic features and to utilize the results for interpreting depositional environments. A 3D seismic dataset from the Tui-3D Field, the Taranaki Basin, New Zealand with well data were used to visualize structures, to detect stratigraphic features, to identify main lithology, to understand depositional environment, and to describe seismic facies and reflection patterns of the target horizons. The major formations are in the Kapuni Group.

Seismic structural interpretation indicates thirty-two minor faults, which may play an important role in …

Variable Stress Orientations In The Offshore Nile Delta: The Role Of Salt As A Mechanical Detachment Horizon, Weicheng Zhang

Masters Theses

"The offshore Nile Delta is characterized by variations of the maximum horizontal stress orientation in subsalt and supra-salt sequences. Margin-parallel SH, typical for tertiary deltas, is observed for regions that are below or do not contain evaporites. In sequences underlain by evaporates pre-dominantly margin-normal SH is observed. This observation yielded the first conclusive in situ evidence that salt acts as a mechanical detachment layer. In this study, 3D finite element analysis (FEA) is used to simulate the total stress distribution in the offshore Nile Delta featuring evaporate sequences. Several parameters such as different salt sequence geometries, friction coefficient on faults, …

Study On The Applicability Of Relative Permeability Modifiers For Water Shutoff Using Numerical Simulation, Dheiaa Khafief Khashan Alfarge

Masters Theses

"Water production is a challenging problem to be controlled during hydrocarbon-reservoirs production life. Disproportionate Permeability Reduction (DPR) is often used as water shutoff treatment in production wells when other conventional solutions like mechanical isolations are difficult to perform. This study applied numerical simulation methods to diagnose the factors impacting DPR treatment success on macroscopic level and to see when, where and at which conditions DPR treatment can give best results.

This work indicated that the following points should be considered before DPR treatment is executed in any reservoir to get a successful treatment. Firstly, this research explored that DPR performance …

A Control Algorithm For The Solar Village Microgrid System, Hamad Ahmed Alharkan

Masters Theses

"In this thesis, the concept of microgrid system is introduced. Also, the major components of a microgrid will be discussed thoroughly. Both grid-connected and autonomous modes are explained. In addition, the control of a microgrid is defined for the following types: local, centralized and decentralized control.

As one of the nation's premiere research universities, the Missouri University of Science and Technology has built four inspirational solar houses (solar villages) for a competition in the US Department of Energy Solar Decathlon to allow students to research and improve different aspects of the microgrid system. Consequently, this thesis develops a computer model …

Prediction Of Surface Roughness In Abrasive Waterjet Cutting Of Graphite Composite Using Response Surface Methodology, Prabhakar Bala

Masters Theses

"In the present work, surface roughness after machining of composite material was the main focus of study. Response surface methodology with Box- Behnken experimental design was applied in predicting the surface roughness (R_a) of abrasive waterjet cut 1-inch-thick graphite/epoxy composite. Second order response equations for R_a were generated with minitab, a statistical software as a function of pressure, traverse speed and isolated abrasive mesh size. Influence of each of these factors on the response were analyzed with 3D response surface plots. Abrasive mesh size was also found be a factor influencing Ra along with traverse speed and …

Shale Instability Of Deviated Wellbores In Southern Iraqi Fields, Ahmed Ali Shanshool Alsubaih

Masters Theses

"Wellbore instability problems are the cause for the majority of nonproductive time in the southern Iraqi fields' developments. The most severe problem in terms of effort and disbursement which is referred to a pipe sticking in Tanuma shale formation. Examining the drilling data revealed that this phenomenon was mostly related to the shear failure of the wellbore. Thus, a geomechanical analysis and drilling parameters/ practice optimization analysis were performed on a field in southern Iraq based on data from 45 deviated wells. The geomechanics analysis predicted the suitable drilling fluid density to prevent onset shear failure by using the Mogi-Coulomb …

Mixing Dynamics In Municipal Water Storage Tanks, Pramod Narayan Bangalore

Masters Theses

"The purpose of this study is to investigate the effects of different control variables on mixing in municipal water storage tanks using Computational Fluid Dynamics(CFD) solutions with ANSYS FLUENT for isothermal, positively and negatively buoyant inflow conditions. Poor mixing of old water and new water leads to dead zone formation, which when introduced in the distribution system can cause major water quality issues. Data for this study was generated using Multiphase CFD flow modeling technique using Volume of Fluid (VOF) approach with species transport. The vessel was considered to be mixed when Coefficient of Variation (COV) dropped below 0.10.

Results …

Attenuation Properties Of Cement Composites: Experimental Measurements And Monte Carlo Calculations, Raul Florez

Masters Theses

"Developing new cement based materials with excellent mechanical and attenuation properties is critically important for both medical and nuclear power industries. Concrete continues to be the primary choice material for the shielding of gamma and neutron radiation in facilities such as nuclear reactors, nuclear waste repositories, spent nuclear fuel pools, heavy particle radiotherapy rooms, particles accelerators, among others. The purpose of this research was to manufacture cement pastes modified with magnetite and samarium oxide and evaluate the feasibility of utilizing them for shielding of gamma and neutron radiation. Two different experiments were conducted to accomplish these goals. In the first …

Mechanistic Understanding Of Water-Rock Interactions During High-Salinity Water-Flooding Of Carbonate Reservoirs, Pu Han

Masters Theses

"Chemically tuned water-flooding provides a relatively cheap method of enhanced oil recovery from carbonate and sandstone reservoirs. Several possible recovery mechanisms such as mineral dissolution, multi-component ion exchange, double-layer expansion, adsorption/desorption from rock surface, reduction in interfacial tension, and fines migration that have been proposed are widely debated. The combination of these processes may result in wettability alteration that increases sweep efficiency of water-flooding. Here, wettability alteration due to water-rock interactions will be examined numerically.

To evaluate the wettability alteration, separation between breakthrough curves of the non-reactive component and the cations based on the chromatographic separation will be used due …

A Study On Non-Metallic Inclusions In Foundry Steel Process, Marc Leonard Harris

Masters Theses

"The effects of sample area and automated SEM/EDS feature analysis parameters (step size, magnification and threshold) on nonmetallic inclusion characterization results has been investigated and optimized. A post-processing program was developed to automatically determine average inclusion chemistry, total element concentrations within inclusions, and for generating joint ternary diagrams with size visualization for representing nonmetallic inclusion populations. Using these tools the evolution of nonmetallic inclusions was examined for 4320 steel at a participating industrial steel foundry. The steel was sampled throughout electric arc furnace melting through ladle refining to the final casting where an in-mold sampling procedure was developed to procure …

Hybrid Manufacturing Processes For Fusion Welding And Friction Stir Welding Of Aerospace Grade Aluminum Alloys, Megan Alexandra Gegesky

Masters Theses

"Friction stir welding and processing can provide for joints in aerospace grade aluminum alloys that have preferable material properties as compared to fusion welding techniques. Aerospace grade aluminum alloys such as AA2024-T3 and AA7075-T6 are considered non-weldable by traditional fusion welding techniques. Improved mechanical properties over previously used techniques are usually preferable for aerospace applications. Therefore, by combining traditional fusion welding and friction stir processing techniques, it could be plausible to create more difficult geometries in manufactured parts instead of using traditional techniques. While this combination of fusion welding and friction stir processing is not a new technology, its introduction …

Design Of A Microwave Imaging System For Rapid Wideband Imaging, Matthew Jared Horst

Masters Theses

An imaging system composed of two linear arrays of antennas is designed through full-wave simulation and fabricated for use in synthetic aperture radar imaging. The arrays electronically scan along their antenna elements and are mechanically moved along a second orthogonal direction for scanning large two-dimensional areas quickly. Each linear array is printed on a circuit board where the antenna elements are integrated into the edge of the board as tapered slot-line antennas operating at 22 to 27 GHz. A multiplexer circuit is printed onto each linear array to transmit wideband signals to each antenna in the array. Receivers are printed …

Mixed Metal Oxide Catalysts Supported On H-Beta For Hydrogenolysis Of Glycerol Into 1,3-Propanediol, Amit Kant

Masters Theses

"Bioglycerol is the by-product which is produced largely from the microbial fermentation, hydrogenolysis of glucose in the mixture of polyols, fatty ester, soap manufacturing process and fatty acid production. Hydrogenolysis of glycerol is one of the most promising ways to convert glycerol and many work has been done towards 1,3-propanediol, 1,2-propanediol and 1-propanol using various metals and mixed-metal oxides such as W, Ru, Rh, Pt, Pd, Cu, Ni and different zeolites have been extensively used as the active components.

It has been well documented that the presence of Bronsted acid sites leads to the formation of acrolein, while Lewis acid …

Influence Of Mix Design Parameters On Dynamic Segregation Of Self-Consolidating Concrete And Consequences On Performance Of Precast Beams, Aida Margarita Ley Hernandez

Masters Theses

"Self-Consolidating Concrete (SCC) is more vulnerable to stability problems as a consequence of its high flowing ability compared to conventional vibrated concrete. Dynamic segregation refers to the tendency of the concrete constituents to separate from the suspended matrix, usually in horizontal direction while being cast into the formwork or due to an impact. Similarly to static segregation, dynamic segregation can affect the homogeneity of SCC. Therefore, it is highly essential to ensure a proper dynamic stability in order to enhance the uniformity of in-situ properties of pre-stressed beams.

In this research project, the effects of SCC mix design parameters are …

Radiation Noise Source Modeling And Near-Field Coupling Estimation In Rf Interference, Liang Li

Masters Theses

"With increasing complexities and shrinking size of modern electronic devices, the near-field RF interference issues are becoming challenging for RF-digital mixed circuit design. Predicting the coupling from digital module to RF antennas and mitigating RF interference is important to the system performance. The ultimate goal of this study is to address the desensitization issues existing in modern electronic devices that have mixed high speed digital-RF circuits, such as cellphone and wearable devices.

In order to estimate the near-field noise coupling from digital module to RF antennas, the noise source is anticipated to be replaced by its equivalent radiation model which …

Thrust Sensing For Small Uavs, Christopher Scott Marchman

Masters Theses

"Unmanned aerial vehicles (UAVs) have become prevalent in both military and civilian applications. UAVs have many size categories from large-scale aircraft to micro air vehicles. The performance, health, and efficiency for UAVs of smaller sizes can be difficult to assess and few associated instrumentation systems have been developed. Thrust measurements on the ground can characterize systems especially when combined with simultaneous motor power measurements. This thesis demonstrates the use of strain measurements to measure the thrust produced by motor/propeller combinations for such small UAVs. A full-bridge Wheatstone circuit and electrical resistance strain gauges were used in conjunction with constant-stress cantilever …

Evaluating Completion Performance For Gas Wells In The Upper And The Lower Montney Formation, Canada, Omar Qasim Mohammed

Masters Theses

"Identifying the key drivers for success of multiple fractured horizontal wells is not straightforward, especially in unconventional reservoirs like the Montney. Al-Alwani et al. (2015) provided a statistical analysis of Montney completions based on publicly available data. They showed that for the entire well population, cumulative gas recovery per stage, declines as the number of completed stages increase. However, their statistical analysis did not differentiate between completions in the Upper/Middle/Lower Montney, and did not include perforation cluster data.

This work documents the statistical analysis of 296 cased-hole horizontal gas well completions reported in the Upper and the Lower Montney. The …

Developing An Idealistic Model To Characterize And Optimize A Photovoltaic Battery Systems, Pavani Reddy Nalladimmu

Masters Theses

"Solar energy is one of the most abundant and clean energy sources of renewable energy. Due to its unsteady nature, most photovoltaic systems require a solar storage system. Ultracapacitors have proven to be an effective solar energy storage component due to their wide range of input voltages and high power density. This research focuses on characterizing the performance of a PV/UCAP hybrid storage system to meet required household loads at various locations throughout the US as a backup energy source. A calibrated empirical model was developed to characterize system performance. A load profile was designed based on a typical 2 …

Deterministic Simulation Of Thermal Neutron Radiography And Tomography, Rajarshi Pal Chowdhury

Masters Theses

"In recent years, thermal neutron radiography and tomography have gained much attention as one of the nondestructive testing methods. However, the application of thermal neutron radiography and tomography hindered by their technical complexity, radiation shielding, and time-consuming data collection processes. Monte Carlo simulations have been developed in the past to improve the neutron imaging facility's ability. In this present work, a new deterministic simulation approach has been proposed and demonstrated to simulate neutron radiographs numerically using a ray tracing algorithm. This approach has made the simulation of neutron radiographs much faster than by previously used stochastic methods (i.e Monte Carlo …

Study Jitter Amplification Of A Passive Channel And Investigation Of S₂₁ Magnitude Extraction Methodologies Using A Pattern Generator And Oscilloscope, Xinyun Guo

Masters Theses

"Recently the clock channel jitter amplification has been observed in several publications. Currently in many high-speed I/O systems, to avoid the cost and the complex clock recovery circuit design, people use traces forwarding clock signal from transmitting IC to receiving IC. When these clock traces are long enough, the amount of attenuation will induce not only inter-symbol-interference (ISI) but also modulate with the input jitter. Eventually it will lead some type of jitter been amplified after the channel. Similarly, the high speed communication channel (data channel) will also face this issue. Since there are no studies on the jitter amplification …

Intensity Control Of Dielectric Barrier Discharge Filaments, Matthew Crawford Paliwoda

Masters Theses

"When operated in a filamentary mode, a volume dielectric barrier discharge (DBD) is known to produce patterned plasma structures. These structures are currently being explored for reconfigurable metamaterial applications. In this work the presence and intensity of a single filament, within an array of filaments, was controlled by adjusting the voltage to that filament's individual needle electrode. The current, voltage, and time-averaged normalized light intensity were measured while varying the voltage of the needle through a self-biasing resistance. For a 7.5 kV, 3.2 kHz DBD in air, the needle-controlled filament intensity varies from that of the surrounding filaments to zero …