Engineering Commons^™

1-D Coordination Polymer Of Transition Metal As A Precursor To Generate Surface Active Transition Metal Catalyst, Siddharth Gopalakrishnan

Masters Theses

"The work describes the synthesis, characterization and properties of Ni, Co and Cu based 1-D coordination polymer with 1, 4-benzenedicarboxylic acid as linker and 1-methylimidazole as co-ligand. The structure of the coordination polymers were investigated employing SCXRD and showed the formation of supramolecular 3-D architecture of the 1-D coordination polymer through non covalent CH..π, π.. π, and H-bonding interaction. These 1-D coordination polymers were further characterized by IR spectroscopy and thermogravimetric analysis. Thermal decomposition of these polymeric metal complexes gave rise to carbon coated metal and metal carbides nanoparticles, for the 1-D structures of Co and …

The Effects Of Short Delay Times On Rock Fragmentation In Bench Blasts, Margaret Ruth Hettinger

Masters Theses

"Optimized rock fragmentation is essential for minimizing downstream costs to mining operations. Photographic fragmentation analysis, vibration monitoring, and high-speed video all provide measurements of blast effectiveness and supply data that allows operations to modify blasts to achieve downstream goals.

This study evaluates the effects of short hole-to-hole delay times on rock fragmentation. Photographic fragmentation analysis and various delay times were used on the same bench blast, the effects of timing on fragmentation were determined. This analysis provides a representative understanding of timing effects on fragmentation in the field, different from previous blast models which either negate the effects of timing …

Emission Source Microscopy Applications On Emi Source Localization And Emi Mitigation With Lossy Materials, Xiangyang Jiao

Masters Theses

"In Section 1, the emission source microscopy (ESM) methodology will be introduced and used to identify the sources of radiation on different DUTs. As the new technology generation, the integration density and the operating speed of integrated circuits have been increasing steadily. However, root cause diagnostics to locate the source of EMI radiation is more problematic in the complex system. The ESM technique provides a powerful tool to detect and characterize the active sources of radiation. The amplitude and phase of fields are measured on a plane away from the DUT, and this measurement can get rid of the evanescent …

An Investigation Of Shear-Friction Of Lightweight Aggregate Concretes, Kristian Krc

Masters Theses

"This thesis reports the results of research initiated to evaluate the influence of lightweight aggregate type and casting procedure on shear transfer across an interface of concretes cast at different times. The topic of shear transfer has been evaluated and revisited in recent PCI Design Handbooks. In this test program, a series of cold joint as well as monolithic specimens are evaluated. The peak shear strength and post peak behavior are examined. The experimental matrix included 28 push-off specimens that were either cast monolithically or cast at different times creating the condition referred to as a cold joint. The variables …

Healing Of Bone Defects In A Rodent Calvarial Defect Model Using Strong Porous Bioactive Glass (13-93) Scaffolds, Yinan Lin

Masters Theses

"The main objective of this project was to evaluate the capacity of strong porous silicate (13-93) bioactive glass scaffolds prepared by a robocasting technique to regenerate bone and stimulate angiogenesis in a rat calvarial defect model. The scaffolds were created with the same grid-like microstructure but in a variety of formulations: (i) as-fabricated, (ii) pretreated in an aqueous phosphate solution to convert the glass surface to hydroxyapatite, (iii) loaded with bone morphogenetic protein-2 (BMP2) (1 µg per scaffold), and (iv) doped with copper (0.4-2.0 wt. % CuO). When compared to the as-fabricated scaffolds, the pretreated scaffolds enhanced bone regeneration at …

Investigation Of Decoupling Capacitor Connection Methods Using Peec And Study Of Alien Crosstalk From A Broadr-Reach® Protocol Based System, Tamar Makharashvili

Masters Theses

"Power Distribution Network (PDN) for Printed Circuit Board (PCB) design requires proper power integrity analysis. In order to deliver a low-ripple DC voltage from a Voltage Regulator Module (VRM) to an Integrated Circuit (IC), a certain target input impedance should be achieved. Developing simple physics-based equivalent circuit models are essential for understanding how a system works and making crucial design decisions. In this work, the input impedance of a decoupling capacitor due to traces, pads and via discontinuities are investigated using the Physics-based Model Size Reduction (PMSR) method. Various decoupling capacitor connection methods are compared and design guidelines are provided …

Space-Based Relative Multitarget Tracking, Keith Allen Legrand

Masters Theses

"Access to space has expanded dramatically over the past decade. The growing popularity of small satellites, specifically cubesats, and the following launch initiatives have resulted in exponentially growing launch numbers into low Earth orbit. This growing congestion in space has punctuated the need for local space monitoring and autonomous satellite inspection. This work describes the development of a framework for monitoring local space and tracking multiple objects concurrently in a satellite's neighborhood. The development of this multitarget tracking systems has produced collateral developments in numerical methods, relative orbital mechanics, and initial relative orbit determination.

This work belongs to a class …

A Sentence-Based Image Search Engine, Weizhi Meng

Masters Theses

"Nowadays people are more interested in searching the relevant images directly through search engines like Google, Yahoo or Bing, these image search engines have dedicated extensive research effort to the problem of keyword-based image retrieval. However, the most widely used keyword-based image search engine Google is reported to have a precision of only 39%. And all of these systems have limitation in creating sentence-based queries for images.

This thesis studies a practical image search scenario, where many people feel annoyed by using only keywords to find images for their ideas of speech or presentation through trial and error. This thesis …

Studies On The Role Of Organic-Inorganic Hybrid Polyacrylamides In Fine Coal Flotation, Ontlametse Kenneth Molatlhegi

Masters Theses

"The current study investigated the effect of novel organic/inorganic (hybrid) polyacrylamide polymer as ash (slimes) depressant in fine coal flotation for the possibility to enhance the combustible recovery and ash rejection. Raw coal samples contain about 25% of ash-forming minerals were crushed, grinded to -75um and floated in the presence of in-house synthesized hybrid Polyacrylamide (Al(OH)₃-PAM or Al-PAM) at different operational parameters. Denver flotation cell with a 5-Liters capacity was used and the parameters investigated include: Al-PAM dosage, Al-PAM conditioning time, dual use of Al-PAM and a dispersant, impeller rotation speed and pulp's pH. For comparison purposes, commercially …

Detection And Cancellation Of Sinusoidal Fading Power Variation In Wireless Communication Systems, Sushruth Sastry

Masters Theses

"Fading channel estimation in wireless communication systems depends on an expected model for fading and any assumptions made about the channel itself. The bit error rate (BER) performance of the communication system is affected by how closely these assumptions made in designing the estimation technique match the deployment environment. Any unforeseen disturbances or hindrances in the environment deteriorate the BER performance of the system when the estimation system is not designed to combat such disturbances. To deal with such unforeseen obstacles, additional mathematical models can be proposed to model such disturbances and then the estimation techniques can either be reinforced …

Advanced Sustainable Concrete Materials For Infrastructure Applications, Kaylea Ann Smith

Masters Theses

"This study was performed to examine the effects of cement replaced by high volumes of Class C fly-ash on durability characteristics of concrete up to 120 days. Specifically, this study investigates possibility of amending American Society for Testing and Materials (ASTM) to allow High Volume Fly-ash (HVFA) concrete to cure until later ages prior to testing instead of 28 days. Five mix designs were compared with varying fly-ash percentages from 0 to 70% (by total cementitious mass). No other additives were present in any of the five mix designs. Water-to-cementitious ratio (w/cm) and total cementitious material remained constant as 0.40 …

A Subband Kalman Filter For Echo Cancellation, Rakesh Vijayakumar

Masters Theses

"This thesis involves the implementation of a Kalman filter for the application of echo cancellation. This particular Kalman filter is implemented in the frequency domain, in subbands, so as to make it faster and of lesser calculational complexity for real time applications. To evaluate the functioning of this subband Kalman filter, comparison of the performance of the subband Kalman filter is done with respect to the original time domain Kalman filter, and also with other subband adaptive filters for echo cancellation such as the NLMS filter. Additionally, since background noise affects the working of any adaptive filter, the newly developed …

The Impact Of A Strong Local Supply Chain On Regional Economic Impacts Of Mining, Meiyu Xing

Masters Theses

"With growing social conflicts due to social and environmental concerns mines need to be able to create shared value for all stakeholder in their quest to promote sustainable development. Given the sensitivity of a mine's regional economy contribution to its supply chains, any improvement in supply chains strategy will be beneficial for mines and their stakeholders. The objectives of this work were to: (i) test the hypothesis that supply chain management strategy, by mines in a region, significantly affects regional economy; and (ii) develop a methodology to identify the critical backward commodities of a regional mining sector.

Valid methods have …

Uncertainty Quantification Of Turbulence Model Closure Coefficients For Transonic Wall-Bounded Flows, John Anthony Schaefer

Masters Theses

"The goal of this work was to quantify the uncertainty and sensitivity of commonly used turbulence models in Reynolds-Averaged Navier-Stokes codes due to uncertainty in the values of closure coefficients for transonic, wall-bounded flows and to rank the contribution of each coefficient to uncertainty in various output flow quantities of interest. Specifically, uncertainty quantification of turbulence model closure coefficients was performed for transonic flow over an axisymmetric bump at zero degrees angle of attack and the RAE 2822 transonic airfoil at a lift coefficient of 0.744. Three turbulence models were considered: the Spalart-Allmaras Model, Wilcox (2006) k-ω Model, and the …

Steam Flooding Screening And Eor Prediction By Using Clustering Algorithm And Data Visualization, Na Zhang

Masters Theses

"Enhanced Oil Recovery (EOR) techniques are vitally important in the oil industry because these techniques could not only extend the life of wells, but also produce 10% to 30% additional oil from the reservoir. However, selecting the most suitable EOR techniques for unknown reservoirs is not easy for decision making. Based on literature, EOR screening criteria could help to find the best candidates for unknown projects, which is classified into two categories: conventional EOR screening and advanced EOR screening. In this research, an artificial intelligent (AI) method, hierarchical clustering algorithm, is adapted to analyze both steam flooding projects and worldwide …

Shear-Friction Of Sand-Lightweight Clay And Slate Aggregate Concretes With Varied Reinforcement Ratios, Samantha Lynn Wermager

Masters Theses

"This thesis focuses on the structural properties of sand-lightweight aggregate concrete in terms of shear transfer strength at cold-joint interfaces. This type of interface is common for precast concrete connections which are typically designed using the shear-friction concept. This testing program was meant to expand the shear-friction database and evaluate the appropriateness of current shear-friction design provisions with respect to sand-lightweight concrete. This study builds on the work done by Shaw (2013) who studied lightweight expanded shale aggregate concrete. The current study included thirty-two push-off specimens constructed from sand-lightweight concrete with a target compressive strength of 5,000 psi. Either expanded …

Survey And Data Analysis Of Polymer Flooding Pilot And Field Applications In China, Yandong Zhang

Masters Theses

"Enhanced oil recovery (EOR) processes are regarded as important methods to recovery remaining oil after primary and secondary recovery. It is significant to select the most appropriate EOR process among the possible techniques for a candidate reservoir. EOR screening criteria has been created using available EOR datasets and served as the first step to compare the suitability of each EOR method for a particular reservoir. Most of these datasets are collected from EOR surveys published by Oil & Gas Journal. This study proposes a comprehensive study of a dataset including 55 pilot and field polymer flooding applications in China. Statistical …

Methods For Checking And Enforcing Physical Quality Of Linear Electrical Network Models, Mikhail Zvonkin

Masters Theses

"Most CAD tools allow system-level simulation for signal integrity by computing and connecting models together for the various sub-parts. The success of this model derivation depends on the quality of the network parameters. Different errors may seriously affect the quality of the frequency characterization: frequency-dependent measurement errors, errors due to the numerical simulation and/or discretization, etc. When these errors are large, model assembly and simulation becomes difficult and may even fail. This thesis gives an overview of the most significant properties of physically valid network parameters, describes existing methods for checking and enforcing these properties, and presents several new methodologies …

Analysis And Comparison Of Two High-Gain Interleaved Coupled-Inductor Boost Converters, Venkat Sai Prasad Gouribhatla

Masters Theses

"The main objective of this thesis is to compare and analyze two different high-gain dc-dc power electronic converters based on coupled inductors and capacitor-diode multiplier cells. The idea of these converters is to integrate the solar energy with a 400V DC microgrid. DC microgrids are more efficient, less expensive, and more reliable compared to AC microgrids. They also favor the integration of renewable energy sources. With the growing need for the utilization of more renewable sources of energy, photovoltaic panels have become one of the trending technologies which convert the energy from the sun to a useable electrical power. But …

Factors Affecting The Heat Transfer During The Dip Testing Of Potential Third Generation Advanced High Strength Steels, Kramer Michael Pursell

Masters Theses

"A dip tester was designed and built at Missouri University of Science and Technology to test the effects of the primary alloying elements (Mn, Si, and Al) of Fe-Mn-Al-Si-C type 3rd generation advanced high strength steel (AHSS) alloys, dipping superheat, and dipping speed on the heat transfer during rapid solidification. The difficulties associated with casting 3rd generation AHSS were compiled as well to serve as a best-practices guide. An extensive list of potential 3rd generation AHSS alloys was developed and tested, and the effects of various dip testing parameters were examined.

Manganese was found to increase the heat flux by …

On-Die Sensors For Transient Events, Mihir Vimal Suchak

Masters Theses

"Failures caused by transient electromagnetic events like Electrostatic Discharge (ESD) are a major concern for embedded systems. The component often failing is an integrated circuit (IC). Determining which IC is affected in a multi-device system is a challenging task. Debugging errors often requires sophisticated lab setups which require intentionally disturbing and probing various parts of the system which might not be easily accessible. Opening the system and adding probes may change its response to the transient event, which further compounds the problem.

On-die transient event sensors were developed that require relatively little area on die, making them inexpensive, they consume …

Chemical Quantification With Ubiquitous Optoelectronic Devices, Altamash Mukhtar Fakki

Masters Theses

"Optical sensing in medical diagnosis and chemical analysis using optoelectronic devices is a growing technology since it offers many advantages including real time analysis, remote sensing capability and low cost approach. This thesis demonstrates that an optical sensing platform utilizing optical mouse, the ubiquitous optoelectronic computer peripheral, can be used in quantitative oxygen and pH analysis.

Work in the first paper includes the use of optical mice for fluorescence intensity imaging of commercial oxygen patch. This involves gray color intensity analysis of filtered images to determine the gaseous oxygen level.

In the second paper, the optical mice is used to …

In Vitro Study Of Wound-Healing Capabilities Of Bioactive Glass Fibers Under Various Culture Conditions, Sisi Chen

Masters Theses

"Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying physiological and cellular mechanism behind this function remains unclear. In this study, in vitro dynamic flow modules were designed to mimic the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, and were used to investigate the biocompatibility and functionality of borate glass nano-/micro-fibers. Glass-cell interactions were investigated either by dosing fibers to the upstream of or co-cultured with cells, and two types of borate glasses (with or without CuO/ZnO doped were …

Determination Of Setting Times By Shear Wave Velocity Evolution In Fresh Mortar Using Bender Element Method, Jianfeng Zhu

Masters Theses

This study aims at using modified bender element (BE) method to monitor the shear wave velocity (V_s) of mortar at early-age and determine initial and final setting times with the V_s method. Modifications of the traditional BE method have been made to overcome the aggressive cementitious environment and eliminate electromagnetic coupling. BE has been successfully employed in mortar samples with and without admixtures to evaluate the evolution of V_s during the early age (first 24 hrs) of hydration. An energy approach method of determining the first arrival time of S-wave has been proposed. Pulse wave velocity …

Understanding Impurities In Copper Electrometallurgy, Paul Laforest

Masters Theses

"This work involves examining two industrial reports of methods to handle impurities in copper electrowinning and electrorefining. The first part evaluates the addition of Hydrostar, Cyquest N-900, DXG-F7, and Guartec EW to copper electrowinning electrolyte to affect MnO₂ deposition on coated titanium anodes (CTAs). The second part examines the effects of anode chemistry and thiourea addition on the ductility of electrorefined copper starter sheet.

In part one, a laboratory cell was used to simulate a short cycle electrowinning cell via chronopotentiometric operation with an IrO₂-Ta₂O₅ CTA at 40⁰C. A cyclic voltammetric sweep was applied …

Developing A Novel Methodolgy And Testbed For Fatigue Analysis Of Metal Specimens, Sai Aravind Palepu

Masters Theses

"A prototype of fatigue testing machine was built to determine the fatigue strength of materials. Proposed testing prototype was displacement controlled magnetic type bend fatigue testing machine. Designed prototype was tuned to operate at or near resonance of the specimen in order to amplify excitation displacement. Low maintenance i.e. zero wear of the parts was achieved, there were no moving components in the prototype machine. Crucial components used to build were: DC power supply, solenoid, Arduino UNO, supports and laser displacement sensor. DC source used to pass current through solenoid producing magnetic field; mosfet and Arduino generated square waves of …

Damage Detection Through Acoustic Emission Of Fracture Processes In Concrete Masonry Units, John Alexander Cain

Masters Theses

"Masonry structures are vulnerable to earthquakes; their brittleness and discontinuous formation make them susceptible to collapse. In the event of an emergency, this could be detrimental and perhaps fatal. The area of Structural Health Monitoring (SHM) is focused on understanding the behavior of structures for the sake of safety and predicting their longevity. One applicable technique to monitor this behavior is Acoustic Emission (AE). Acoustic Emissions are transient elastic waves released as microcracks nucleate from stress intensities, coalesce into cracks and then accumulate as damage. AE monitoring is a favorable method because it is capable of detecting cracking from within …

Development Of Two Color Imaging Pyrometer For Studying Thermal History Of Laser Metal Deposition, Niroop Matta

Masters Theses

"The laser aided manufacturing process is a process in which parts are built by adding material into the melt pool created by a laser. This process involves a complex thermal history which is important in determining the quality of the parts built. The objective of this study is to develop a high resolution two color imaging pyrometer which can measure the temperature of an object without the dependence of spectral emissivity of the material at an economical price. An 8.8 MP CMOS sensor is used as an imaging sensor. The visible spectrum of light is used for temperature measurement. The …

A Force Feedback Haptic Interface For Atomic Force Microscopy, Abdulmohsen Alabdulmuhsin

Masters Theses

"Integrating a force feedback haptic device with atomic force microscopy (AFM) improves the capability to investigate and manipulate the objects on a micro- and nanoscale surface. The haptic device provides the researcher with a sense of touch and movement by changing the position of the stylus or amount of force on it. The developed system's concept is to provide the user a sense and feel and control of the AFM probe at the nanoscale. By positing the haptic stylus, the user generates reference to commands to the AFM probe. In turn, forces experienced by the probe are communicated to the …

Hybrid Manufacturing Process Of SicF/Sic Composite Using Preceramic Polymer, Robert Raymond Meinders

Masters Theses

"Continuous fiber-reinforced silicon carbide (SiC_f/SiC) ceramic composites have been increasingly used due to their high temperature strength and graceful failure mechanisms. A disadvantage is the high cost and lengthy production processes that are required to develop these materials. Polymer infiltration and pyrolysis (PIP) is one of the most attractive fabrication processes for composites due to shape flexibility, mass production and relatively low cost; however, the quality of material obtained by this method has been considered insufficient due to the microstructure defects of the material obtained. This study investigated a hybrid of multiple polymer manufacturing processes to maximize quality …