Digital Commons Network^™

Cellular Hitchhiking Via Injectable Microparticles, Daniel Smith

Masters Theses

"Tissue engineering is a process of developing new tissues in a host. Tissue engineering draws upon revitalizing damaged tissues that otherwise would not heal completely from the body's natural response. To augment the body's natural response to impairment, cells can be transplanted to the afflicted area to boost the healing response. Implementing these cells onto scaffolds and transplanting them into the body improves the healing response dramatically. Tissue regeneration improves when a biodegradable scaffold is used in conjunction with cells to augment the body's healing response. Microparticles provide a surface that can mimic the environment cells perceive in vivo, …

Proppant Transport With Varying Injection Points And Its Impact On Proppant Development Inside A Fracture, Shail Janakbhai Soni

Masters Theses

"This study presents experimental work which examines the effect of perforation placement and density on proppant placement within a hydraulic fracture. The study also investigates the effect of proppant angularity.

Experiments were conducted with ceramic proppant injected in a fracture slot model consisting of three injection points at the bottom, middle and top of the fracture slot, and two outlets, at the bottom and top of the fracture model. The effect of single point injection height was investigated by injecting solely at the bottom, middle or top of the apparatus, for both bottom and top outlet conditions. Multiple injection points …

Lyapunov Stability Analysis Of Switched Microgrid Systems, Bokang Zhou

Masters Theses

"In this thesis, a Lyapunov-based method for analyzing the stability of a switched microgrid system is proposed. First, a small second-order system is explored as example to demonstrate the effectiveness of switching patterns on the stability of a system switching among different respectively stable operating points. Lyapunov function is employed in order to determine the proper state-based switching conditions under which global stability is guaranteed, or under which the system is driven unstable. Then, a linearized statespace model of a looped seven-node microgrid is established. Solid-state transformers (SSTs), distributed energy storage devices and synchronous generators are introduced and modeled in …

Numerical Modeling Of Capillary-Driven Flow In Open Microchannels: An Implication Of Optimized Wicking Fabric Design, Mehrad Gholizadeh Ansari

Masters Theses

"The use of microfluidics to transfer fluids without applying any exterior energy source is a promising technology in different fields of science and engineering due to their compactness, simplicity and cost-effective design. In geotechnical engineering, to increase the soil's strength, hydrophilic wicking fibers as type of microfluidics have been employed to transport and drain water out of soil spontaneously by taking advantage of natural capillary force without using any pumps or other auxiliary devices. The objective of this study is to understand the scientific mechanisms of the capability for wicking fiber to drain both gravity and capillary water out of …

Grain Refinement Of High Alloy Stainless Steels In Sand And Directionally Solidified Castings, Dustin Alan Arvola

Masters Theses

"The goal of this research project is to develop an industrially viable melting process that will control the crystallization macrostructure of austenitic grades of cast steels. Titanium nitride (TiN) has proven to be an effective grain refiner of austenite. Theoretical simulation and experimental application has led to the development of a repeatable grain refining melt process for austenitic stainless steel alloys.

Grain refinement of the as-cast structure of Cr-Ni stainless steel alloys solidified with primary FCC, BCC and dual FCC/BCC phases was studied experimentally. Refinement was achieved in both cast ferritic and austenitic grades. Dual solidification of …

Evaluating Microgrid Effectiveness In Transitioning Energy Portfolios, Jacob Marshal Hale

Masters Theses

"Microgrid energy systems have emerged as a potential solution to rising greenhouse gas emissions from dependence on fossil fuels. This research provides a framework for evaluating the utility of microgrids. Three key findings are presented: use of a state-of-the-art matrix (SAM) analysis to identify gaps in key research areas that inhibit wide-spread microgrid adoption, development of a system dynamics (SD) model, and a cost benefit analysis case study to evaluate microgrid feasibility in partially meeting the energy demand of a building. Governments play a central role in developing clean energy strategies. A SAM was developed to determine if key microgrid …

Computational Investigation Of Polymer Electrolyte Membrane Fuel Cell With Nature-Inspired Fibonacci Spiral Flow Field, Suleyman Kose

Masters Theses

"Polymer electrolyte membrane fuel cells (PEMFC) are promising clean energy devices. The flow field design has crucial role in PEMFC performance for effective distribution of reactants and removal of products. Several nature-inspired flow field designs have recently been proposed in the literature. Common characteristics of these designs were sudden changes in the flow direction through sharp bends and flow field geometries restrained to areas having corners. In this thesis, Fibonacci spiral configuration, which is found in the nature from hurricanes to seashells, was considered for flow field pattern of a PEMFC. Contrary to the bio-inspired designs proposed in previous studies, …

Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin

Masters Theses

The purpose of this study was to investigate durable solar cell cover glass joins produced by diffusion bonding with deep eutectic solvents (DES) and to develop a novel process of joining optically transparent materials at low temperatures. A joined PV cell-glass specimen was characterized using Raman, μ-FTIR, SEM-EDS, and thin-film XRD. DESs were created with malonic acid (MAL) and choline chloride (ChCl) of varying composition factors (CF; CF=MAL/ChCl). Joining borosilicate glass coupons was attempted using DESs with CF = 0.65 and 1 at temperatures between 100-150 °C for 20 hours. Joining the glass coupons failed at all temperatures and oxygen …

Effect Of Microstructural Features On Steel Machinability, Mark C. Emmendorfer

Masters Theses

Non-metallic inclusions can have a tremendous impact on the machinability of steel. Some oxide inclusions such as alumina, spinel, and other refractory abrasive oxide inclusions can have a detrimental effect on machinability. Modification of oxide inclusions by calcium treatment can promote the formation of low melting point oxides such as anorthite and gehlenite inclusions that can assist in chip formation and form a lubricating layer on the rake surface of the machine tool. MnS is known to be beneficial to improving the machinability of steel. They assist in chip formation by being heavily deformed in the primary shear zone. Sulfide …

The Development Of A New Formulation Of Fly Ash Class C Based Geopolymer And Assessing Its Performance In Presence Of Drilling Fluid Contamination, Mohamed Saad Ahdaya

Masters Theses

"Cementing is one of the most critical steps in the drilling and completion of oil wells. Traditionally, Portland cement is used for oil cementing operations; however, geopolymer materials have recently attracted much attention because they are more cost-effective and have less environmental impacts.

An intensive laboratory work was conducted to obtain a new formulation of fly ash class C based geopolymer cement to be used as a potential alternative cementing material to Portland cement in oil and gas cementing. Twenty-four variations of fly ash class C based geopolymers were prepared, and by comparing several of their properties using API standard …

Characterization And Tailoring Of Powder Used In Additive Manufacturing And Plasma Spheroidization, Caitlin S. Kriewall

Masters Theses

"There are many processes that use metal powder as the starting material for the production of parts. With the growth of these manufacturing techniques, more critical part applications are being considered. In order to fully understand the process and create consistent parts, powder properties need to be well understood. Selective laser melting (SLM) is a powder bed-based additive manufacturing process. During processing, heat-affected powders are generated and can deposit within the build area. The current work investigated the characterization of heat-affected 304L stainless steel powder using techniques such as scanning electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy to detect …

Imaging The Subsurface In Eastern Part Of Lake Chesterfield Using A Combination Of Geophysical Tools, Jiawei Li

Masters Theses

"The Lake Chesterfield North Dam in Wildwood city, Missouri has been leaking, more or less continuously since the dam was constructed in 1986 despite mitigation efforts in 1988, 1994, 1995, 2004, and 2005. Neither the grouting efforts in 1988, 1994, 1995, 2004 or 2005, nor the placement and rehabilitation of an impervious clay liner in 2005 has solved the problem. Indeed, in June of 2017, the water level in Lake Chesterfield dropped at an alarmingly rapid rate.

Prior to authorizing additional mitigation work, the Lake Chesterfield Home Owners Association (LCHOA) decided to acquire geophysical data across the dry lake bed. …

Classification Of Eeg Signals Of User States In Gaming Using Machine Learning, Chandana Mallapragada

Masters Theses

"In this research, brain activity of user states was analyzed using machine learning algorithms. When a user interacts with a computer-based system including playing computer games like Tetris, he or she may experience user states such as boredom, flow, and anxiety. The purpose of this research is to apply machine learning models to Electroencephalogram (EEG) signals of three user states -- boredom, flow and anxiety -- to identify and classify the EEG correlates for these user states. We focus on three research questions: (i) How well do machine learning models like support vector machine, random forests, multinomial logistic regression, and …

Microstructural Development And Its Effect On Aqueous Corrosion Of A Borosilicate Glass Ceramic For Waste Vitrification, Nicholas Stephen Roberts

Masters Theses

"Waste loadings of reprocessed spent nuclear fuel vitrified into borosilicate glass can be increased by precipitating environmentally stable phases concentrated with waste components in a chemically stable glass matrix. The principal objective of this thesis was to characterize the development of crystalline powellite (CaMoO₄ and related phases) and oxyapatite (Ca₂LN₈Si₆O₂₆) in borosilicate glass-ceramics and to determine how the formation of those phases affected its chemical durability.

Borosilicate glasses provided by PNNL were re-melted and quenched at rates from over 300⁰C/s to ~0.05⁰C/s. Isothermal heat treatment experiments were conducted by quenching melts …

Practical Dwell Times For Switched System Stability With Smart Grid Application, William Roy St. Pierre

Masters Theses

"Switched systems are encountered throughout many engineering disciplines, but confirming their stability is a challenging task. Even if each subsystem is asymptotically stable, certain switching sequences may exist that drive the overall system states into unacceptable regions. This thesis contains a process that grants stability under switching to switched systems with multiple operating points. The method linearizes a switched system about its distinct operating points, and employs multiple Lyapunov functions to produce modal dwell times that yield stability. This approach prioritizes practicality and is designed to be useful for large systems with many states and subsystems due to its ease …

Conical Folds -- An Artifact Of Using Simple Geometric Shapes To Describe A Complex Geologic Structure, Avery Joseph Welker

Masters Theses

"Accurate representation of the 3D shapes of natural folds is essential to characterization of the dynamic models for fold formation. Geometrical analysis of folds commonly relies upon analyzing patterns defined by the variation in the orientation of poles to planar surfaces deformed by a shortening event when plotted using graphical calculators (e.g., stereogram, polar tangent diagrams) to interpret the shape of folds. Stereograms for which orientation data define small circles are classified as non-cylindrical regular folds and are interpreted as "conical folds," where the shape of the fold is represented by a cone that terminates at a point. Utilizing similar …

The Thermal Effects Of Daylighting In An Energy Efficient Home, Thomas Glenn Yarbrough Ii

Masters Theses

"Current trends in building design and construction emphasize the use of natural daylighting to illuminate a building's interior. This study investigated the energy savings that could be obtained through the use of daylighting compared to additional heating and cooling loads attributed to the glazing required for daylighting. The study, through a combination of experimentation and computer model validation, aimed to determine energy saved from daylighting through illumination metering during a nine-month study period. Energy usage trends during this period were observed using circuit-level monitoring equipment. It was determined that, at select times of the year, energy used to account for …

Comparative Toxicology Of Nio And Ni(Oh)₂ Nanoparticles, Melissa Hope Cambre

Masters Theses

“Understanding the potential toxicity of nanoparticles (NPs) is important to ensure that these new products do not impose harmful effects to human and environmental health. Paper I is a literature review in which we discuss characteristics of nanomaterials, with an emphasis on transition metal oxide nanoparticles that influence cytotoxicity. Identification of those properties may lead to the design of more efficient and safer nanosized products for various industrial purposes and provide guidance for assessment of human and environmental health risk. We then investigate biochemical and molecular mechanisms of cytotoxicity that include oxidative stress-induced cellular events and alteration of the pathways …

Coaxial Cable Ring Resonator Based On Pair Sided Coaxial Cable Bragg Grating Coupler For Sensing Appllication, Xiaotong Tang

Masters Theses

“Coaxial cable based devices, such as coaxial cable Bragg grating (CCBG), coiled coaxial cable resonator have been demonstrated for sensing applications to address the challenges faced by fiber optic sensors (e.g., large strain survivability, installation). Inspired by the fiber ring resonator (FRR), coaxial cable based ring resonator (CCRR) is reported in this thesis. The device mainly formed by a homemade coaxial cable Bragg grating (CCBG) pair based side coupler. Comparing to the commercial coupler, CCBG-SC improves the flexibility of the device for sensing applications. The coupling frequency of the CCBG-based coupler can be modified by changing the grating length and …

Distributed Fiber Optic Sensors For Monitoring Spatially Continuous Strain And Quasi-Distributed Refractive Index Using Optical Frequency Domain Reflectometry, Sasi Jothibasu

Masters Theses

"This thesis is comprised of two papers and they describe distributed fiber optic sensing using an optical frequency domain reflectometry (OFDR) instrumentation system.

The first paper presents about distributed fiber optic sensor embedded within the layers of a composite laminates to monitor the continuous profile of strain using the optical frequency domain reflectometry (OFDR) system. The OFDR system was used to analyze the Rayleigh backscattered signal. The shift in the Rayleigh backscattered spectrum (RBS) was observed to be linearly related to the change in strain of the composite material. The continuous strain sensing using OFDR was demonstrated by an INSTRON …

Advanced Process To Embed Optical Fiber Sensors Into Casting Mold For Smart Manufacturing, Raghavender Reddy Jakka

Masters Theses

"Optical fiber sensors embedded in metals with distributed sensing can sense temperature at multiple points with single fiber. This is useful for smart manufacturing like structural health monitoring in aerospace industry and smart molds in manufacturing plants. There is a huge difference in thermal coefficient of expansion for fiber and metal. This is the reason for the increase in sensitivity for embedded fiber sensors. However, at high temperatures, the stress on the fiber increases, eventually damaging the sensor. The fiber-metal interface determines the sensor performance. A tight interface results in high sensitivity and a gap in the interface enhances sensing …

Development Of Hollow Coaxial Cable Fabry Perot Resonator For High Temperature Sensing Applications, Mohammed Farhan Ahmed

Masters Theses

"The thesis is comprised of two papers, the first paper presents the novel High-Quality Factor Coaxial Cable Fabry-Perot Resonator for sensing applications. The sensor is fabricated by creating two highly reflective mirrors in a coaxial cable. The temperature response of the sensor was tested, by monitoring the frequency shift of the reflection spectra as the temperature increased linearly from 35 °C to 80 °C in steps of 5 °C. The sensor exhibited high temperature sensitivity and good measurement resolution.

A high Q factor of 133 was recorded. The second paper in the thesis presents a low cost, robust, homemade hollow …

Cyclic Axial Compression Behavior Of Concrete-Filled Hybrid Large Rupture Strain Frp Tubes, Monika Nain

Masters Theses

"This study introduces an experimental investigation of the behavior of concrete filled fiber reinforced polymer (FRP) tubes (CFFTs) under cyclic axial compression. The FRP used in this study were either small rupture strain FRP (SRS-FRP) or large rupture strain FRP (LRS-FRP). This paper also presents the first-ever experimental study on the behavior of concrete confined using hybrid LRS-FRP and SRS-FRP. LRS-FRP included PEN (polyethylene napthalate) and PET (polyethylene terephthalate) where both of them having ultimate axial strain larger than 5%, and low stiffness. SRP-FRP included carbon and glass FRP having small rupture strains, smaller than 2%, and high stiffness. The …

Fluid Flow In A Krogh Cylinder: A Model For A Single Capillary And Surrounding Tissue, Xianjie Qiu

Masters Theses

"A model describing the flow of plasma from the capillaries to the interstitial space in the extravascular tissue and back into the capillaries is constructed and solved. The flow through the tissue or the interstitial spaces is described by the Brinkman equation for porous medium, modified to account for the presence of cells considered as spheres. The flow of blood through the capillaries is considered to be that of a Newtonian fluid. The flow between capillary and tissue is coupled by the permeability of the capillary wall. The nature of flow and its magnitude was found to be highly dependent …

Untangling The Effects Of Biosynthetic And Metabolic Rates On Oxidative Cellular Damage In An Insect Model, Nikki Jihui Gomez

Masters Theses

“Previously, a theoretical model for unravelling the entwined effects of metabolic and biosynthetic rates on oxidative cellular damage accumulation during an animal’s growth period was developed and tested in hornworms (Manduca sexta larvae). In theory, if an animal had unrestricted amounts of energy and a high repair efficiency, they could repair most of the oxidative cellular damage accumulated, regardless of how their metabolic rate varies. However, organisms have a finite amount of energy that is allocated to repair and, during the animal’s development period, a considerable amount of energy goes towards growth eliciting a tradeoff between biosynthesis and repair. …

Corrosion Performance Of Zirconium-Based Passivations On Electroplated Zinc Nickel, Madison Morgan Reed

Masters Theses

“Performance requirements for Department of Defense (DoD) electrical components include corrosion and electrical contact resistance. Historically, electroplated cadmium with a chromate conversion coating (CrCC) has been used to meet corrosion and contact resistance standards. However, replacements are needed for these materials because they are toxic and carcinogenic. Electroplated γ-ZnNi has been identified as an acceptable alternative to Cd. This study evaluated commercially available Zr-based thin films and sealers as passivations for potential replacement of CrCCs. Ten different passivations were tested and compared with bare γ-ZnNi. X-Bond and Zircobond passivations were found to provide some improvement to the bare ZnNi corrosion …

Epithelium Detection And Cervical Intraepithelial Neoplasia Classification In Digitized Histology Images, Sri Venkata Ravitej Addanki

Masters Theses

“Cervical cancer is one of the most deadly cancers faced by women. It is the second leading cause of cancer death in women aged 20 to 39 years. In order to detect cancer at early stages, pathologists analyze the epithelium region from the cervical histology images. These histology images have a pre-cervical cancer condition called cervical intraepithelial neoplasia (CIN) determined by pathologists. This study deals with automating the process of epithelium detection and epithelium CIN classification in digitized histology images. For epithelium detection, the objective is to detect epithelium regions in microscopy images from non-epithelium regions and background. convolutional neural …

Thermal Curing Efficiency Of Geopolymer Mortars, Simon Peter Sargon

Masters Theses

”Missouri is the fourth largest coal consumer in the U.S. with coal-fired power plants generate 81.3% of the electricity in the state which generate about 2.7 million tons of coal combustion residuals (CCRs) annually. The CCR, including fly ash, disposal issue is not limited to Missouri, rather it is a national issue with CCRs being the second largest waste stream in the U.S. Ninety million tons of fly ash are stored in landfills and ash ponds annually. Hence, using this waste product effectively is necessary. One of the emerging applications of fly ash is to use it as binder in …

Multiscale Approaches Toward Advanced Lithium-Ion Battery: From Nano To Meso Scale, Susmita Sarkar

Masters Theses

“Battery performance and its degradation are determined by various aspects such as the transport of ions and electrons through heterogeneous internal structures composed of constituent particles, kinetic reactions at the interfaces, and a corresponding interplay between mechanical, chemical, and thermal responses. Further, modern battery materials require a variety of engineering processes such as coating, doping and mixing. As a result, in order to fully understand the behavior of the battery material and improve battery performance, it is necessary to understand and control the individual particle behavior and then connect it to the electrode. This study elucidated the physical phenomena associated …

Calibration Of Mine Ventilation Network Models Using The Non-Linear Optimization Algorithm, Guang Xu, Jinxin Huang, Baisheng Nie, Duncan Chalmers, Zhuoming Yang

Mining Engineering Faculty Research & Creative Works

Effective ventilation planning is vital to underground mining. To ensure stable operation of the ventilation system and to avoid airflow disorder, mine ventilation network (MVN) models have been widely used in simulating and optimizing the mine ventilation system. However, one of the challenges for MVN model simulation is that the simulated airflow distribution results do not match the measured data. To solve this problem, a simple and effective calibration method is proposed based on the non-linear optimization algorithm. The calibrated model not only makes simulated airflow distribution results in accordance with the on-site measured data, but also controls the errors …