Digital Commons Network^™

Numerical Modeling Of Infrared Thermography Techniques Via Ansys, Hayder Abdulnabi Thajeel

Masters Theses

"Several inspection techniques have been developed over years. Recently, infrared thermography (IRT) technology has become a widely accepted as a nondestructive inspection (NDI) technique for different fields and various applications as well. Infrared thermography stands as one of the most an attractive and a successful NDI technique that has ability to detect the object's surface/subsurface defects remotely based on observing and measuring the surface's emitted infrared heat radiation by using an infrared camera. The finite element modeling FEM ANSYS was successfully used for the modelling of several IRT techniques; such as Pulsed Thermography (PT) and Lock-in Thermography (LT) that can …

Use Of Ultra-High Performance Concrete To Mitigate Impact And Explosive Threats, Julie Anne Willey

Masters Theses

"This study is a continuation of research conducted by Natalia Carey, Anthony Wulfers, and Dr. John Myers under the DHS ALERT Center. Carey investigated the use of polyurea coating systems to mitigate close range blast threats on wall panels. Wulfers continued this by using both polyurea coatings as well as a sacrificial wood fiber fly ash (WF-FA) layer to try to get increased performance. This research was aimed at the study of ultra-high performance concrete (UHPC) for the use in impact and blast mitigation. There is little information on the performance of UHPC under close range blast loading; therefore it …

Comparison Of Class Ii Injection Well Area Of Review Requirements With Area Of Evaluation For Hydraulically Fractured Wells, Yashesh Jitendra Panchal

Masters Theses

"Since 2010 the US Environmental Protection Agency (EPA) has been proposing plans to study, and has now initiated research regarding the potential impact of hydraulic fracturing processes on drinking water sources. Their work refers to an 'Area of Evaluation' around a hydraulically fractured well, inferring that the wells immediately around hydraulic fractured wells should be studied, to evaluate the conditions of these wells and their potential to contaminate overlying USDWs. Class II injection wells must have a minimum 1/4 mile radius area of review to determine the condition of wells surrounding the proposed injection well. All wells within this AOR …

Development Of A Methodology For Pseudo-Rigid-Body Models Of Compliant Segments With Inserts, And Experimental Validation, Raghvendra Sharadchandra Kuber

Masters Theses

"Compliant mechanisms have shown a great deal of potential in the last few decades in providing better solutions to design problems with numerous benefits; however, their use has been limited due to current challenges in the material selection. With ever increasing focus on the applications of compliant mechanisms, it is necessary to find alternatives to the existing materials and methods of prototyping. The purpose of this work is to develop a methodology for pseudo-rigid-body models of compliant segments with compliant inserts, comprised of a resilient material placed between the layers of a softer material, to alleviate any creep and strength …

Kinetics Of Human And Bovine Insulin Amyloid Fibril Formation In The Presence Of Solid/Liquid Interfaces, Paulina Barranco Morales

Masters Theses

"The purpose of this thesis was to study the rate and extent of aggregation of human and bovine insulin in bulk and in the presence of either polystyrene microspheres with different surface chemistries or liposomes of different composition. Insulin aggregation was followed by turbidimetry, Fourier transform infrared spectroscopy (FTIR), and dynamic light scattering. The Congo red assay was used to corroborate the presence of amyloid deposits and transmission electron microscopy (TEM) was used to analyze the morphology of the amyloid deposits. Our results show that not all the surfaces shortened the lag time. On the other hand, most surfaces had …

Systems And Image Database Resources For Uav Search And Rescue Applications, David Christopher Macke Jr.

Masters Theses

"Aerial search and rescue applications using unmanned aerial vehicles (UAVs) can incorporate image processing technologies to locate targets faster and with a higher degree of accuracy. The task of developing such systems involves the development of both hardware and software components. Examples of both hardware and software approaches in the design process for an aerial imaging system are shown for small UAV applications. This project contains resources to help facilitate the incorporation of UAV applications into educational ventures and design projects. A power supply design is done for a lightweight imaging system and a large database of aerial images is …

Uterine Cervical Cancer Histology Image Feature Extraction And Classification, Cheng Lu

Masters Theses

"Cervical cancer, the second most common cancer affecting women worldwide and the most common in developing countries can be cured in almost all patients, if detected early and treated. However, cervical cancer incidence and mortality remain high in resource-poor regions, where early detection systems often cannot be maintained because of inherent complexity. The National Cancer Institute (NCI) has collected a vast amount of visual information, 100,000 cervigrams (35 mm color slides), screening thousands of women by this technique. In addition to the cervigrams, large digitized histology images are being archived.

In this research, a framework for automatic recognition and classification …

Direct - Drive Permanent Magnet Synchronous Generator Design For Hydrokinetic Energy Extraction, Amshumaan Raghunatha Kashyap

Masters Theses

"Hydrokinetic turbines deliver lower shaft speeds when compared to both steam and wind turbines. Hence, a water wheel generator must operate at speeds as low as 150 - 600 rpm. This thesis describes a permanent magnet synchronous generator (PMSG) that was designed, built, and tested to serve a low speed hydrokinetic turbine. The design methodology was emphasized since designing an application specific generator poses various design and hardware construction issues. These are torque, speed, power and start-up requirements. This generator was built to operate without a speed increaser, implying very low speeds. FEA and performance results from the simulation done …

A Calibration Free Vector Network Analyzer, Arpit Kothari

Masters Theses

"Recently, two novel single-port, phase-shifter based vector network analyzer (VNA) systems were developed and tested at X-band (8.2 - 12.4 GHz) and Ka-band (26.4 - 40 GHz), respectively. These systems operate based on electronically moving the standing wave pattern, set up in a waveguide, over a Schottky detector and sample the standing wave voltage for several phase shift values. Once this system is fully characterized, all parameters in the system become known and hence theoretically, no other correction (or calibration) should be required to obtain the reflection coefficient, (Γ), of an unknown load. This makes this type of VNA "calibration …

Manual Modification And Plasma Exposure Of Boron Nitride Ceramic To Study Hall Effect Thruster Plasma Channel Material Erosion, Alexander J. Satonik

Masters Theses

"Worn Hall effect thrusters (HET) show a variety of unique microstructures and elemental compositions in the boron nitride thruster channel walls. Worn thruster channels are typically created by running test thrusters in vacuum chambers for hundreds of hours. Studies were undertaken to manually modify samples of boron nitride without the use of a hall effect thruster. Samples were manually abraded with an abrasive blaster and sandpaper, in addition to a vacuum heater. Some of these samples were further exposed to a xenon plasma in a magnetron sputter device. Sandpaper and abrasive blaster tests were used to modify surface roughness values …

Analysis Of Model Uncertainty In Hydraulic Modeling: The Bstem Application To The Osage River, Annabell Leigh Ulary

Masters Theses

"Uncertainty is inevitable when creating any kind of model. A model can be used in the most accurate way possible, if the uncertainties are understood. This study determines the level of uncertainty in the Bank Stability and Toe Erosion Model (BSTEM) of the Osage River downstream of Bagnell Dam between Lake Ozark, MO and Jefferson City, MO. The statistical analysis of the BSTEM model was performed using the aid of SAS statistical computer modeling software. There were 4 different analysis values used to determine the best fit model for all dependent variables. These values include the F-test, the coefficient of …

Robust Methods For Construction Of Global Potential Energy Surfaces, Phalgun Lolur

Masters Theses

"This thesis is about the development of robust methods for construction of global potential energy surfaces to study the spectroscopy and dynamics of molecular systems. A potential energy surface represents the electronic energy of a molecule as a function of its geometry. This is central to how chemists view molecular systems in terms of motion across a rich energy landscape where barriers separate wells corresponding to different stable structures. The range of molecular distortions defines the potential energy surface. Computing the potential energy surface of a molecule has become a fundamental operation in modern theoretical chemistry studies. The Born-Oppenheimer approximation …

A Computational Study Of Driven Micro-Cavities In Supersonic Flat Plate Flow, Thomas Ryan Rehmeier

Masters Theses

"Driven micro-cavities embedded in the wall beneath turbulent supersonic boundary layers are analyzed using two-dimensional computational fluid dynamics. This concept is a passive flow control technique in which very small cavities formed by arrays of thin vertical walls are oriented transverse to the flow direction and underlie the boundary layer. The purpose is to reduce or eliminate skin friction drag. Various micro-cavity configurations were analyzed at locations (0.1 m and 1 m) downstream of the leading edges of flat plates, for free-stream Mach numbers of 1.2, 2.0, and 3.0. Results focus on net drag reduction achieved, cavity flow-field effects, perforation …

Trough-Silicon-Via Inductor: Is It Real Or Just A Fantasy?, Rongbo Yang

Masters Theses

"Through-silicon-vias (TSVs) can potentially be used to implement inductors in three-dimensional (3D) integrated system for minimal footprint and large inductance. However, different from conventional 2D spiral inductor, TSV inductors are buried in lossy substrate, thus suffering from low quality factors. This thesis presents how various process and design parameters affect their performance. A few interesting phenomena that are unique to TSV inductors are observed. We then proposed a novel shield mechanism utilizing the micro-channel, a technique conventionally used for heat removal, to reduce the substrate loss. The technique increases the quality factor and inductance of the TSV inductor by up …

Dynamic Contact Analysis Of A Piezoelectrically Driven Ultrasonic Crawler-Actuator, Dwight Santiago Maness

Masters Theses

"A standing wave ultrasonic motor (SWUM) is presented in this thesis. The actuator is piezoelectrically powered and operates in the first and second bending modes to move forwards and backwards, respectively. The kinematic stability of the crawler, backed by experimental results is shown in the first paper presented in this thesis. This study demonstrates that in the absence of a preload or kinematic constraints, the crawler shows vertical stability. A full transient analysis using the finite element method is performed characterizing the speed and contact variables is conducted in the second paper. The results show that given enough time the …

Feature Extraction Through K-Means Segmentation For Melanoma Detection, Snigdha Priya Bommadevara

Masters Theses

"Malignant melanoma is responsible for 75% of the deaths caused due to skin cancer annually. However, melanoma detection can be possible through feature extraction and pattern classification, which can lower the risk, if the melanoma is detected at an early stage. Clustering is one of the most useful tools used to differentiate features that can contribute to melanoma. This research work uses the k-means clustering algorithm for implementation of color segmentation. However, k-means clustering requires a predefined value of k, i.e., the number of clusters must be specified at the beginning of the run. This research uses a predefined value …

Constructing Conducted Emission Models For Integrated Circuits, Shuai Jin

Masters Theses

"Conducted emissions, noise conducted out of integrated circuit pins, play an important role in determining the system level EMC performance. Characterizing conducted emissions from ICs is investigated and the corresponding noise models are developed in this thesis. Both simulation IBIS and measurement based methods for noise-model construction are studied. The constructed noise source model for a test IC is applied in system-level simulations and the calculated far field radiation is validated with measurements. The agreement in the simulated and measured results demonstrates the effectiveness of the constructed model for characterizing the conducted emissions from an IC I/O pin"--Abstract, page iii.

Implementation Of Project Based Learning Technique To Enhance Engineering Education, Dinesh Kanigolla

Masters Theses

"This study investigated the impact of introducing a semester project into three engineering courses where practical application of theoretical knowledge is applicable. Three courses were examined in this work: an undergraduate course in quality, a graduate course in Lean, and a graduate course in Six Sigma. For this research, student teams were given hands-on-projects that included collaboration with local companies. Surveys were conducted to assess the impact of project based learning on students' knowledge. Student responses were recorded and analyzed to determine how students felt the use of the semester project affected the course and to identify the response patterns …

Examining The Efficiency Of Multimodal Transportation Systems: A Systems Dynamics Approach, Lizzette Pérez-Lespier

Masters Theses

"With international trade becoming a big part of the world's economic activity, the demand for good freight transportation systems has grown substantially. The appropriate use of transportation is an integral part of the supply chain's effectiveness. Therefore, the continuous economic globalization, the growing demand for speed-to-market product delivery, and the need to manage global supply chains more effectively, has led to the sustained increase in demand towards multimodal transportation systems (MTS). MTS play an essential role in corporations competing in global markets in the 21st century. In transportation, the effectiveness and efficiency of the whole system depends upon the interconnectivity …

A Study Of Clustering Rssi And Lqi From Wireless Network Communications, Yanwen Wang

Masters Theses

"In today's information world, different wireless sensor network topologies are permitted to exist in the same geographical region. For example, a city contains thousands of enterprise networks; a school might include different wireless network topologies used by students and faculties respectively. Even within a building, there might be multiple companies that use their own wireless networks. These networks might cause interference to other networks. How to detect, determine and locate the unknown wireless topologies in the same geographical area becomes quite significant in the wireless industry, especially in military use, such as spy-nodes detection and communication orientation systems. In this …

Processing And Properties Of Zrb₂-Zrsi₂ Matrix Composites Reinforced With Continuous Sic Fiber, Benjamin John Bowin Lai

Masters Theses

"The research presented in this thesis focuses on the processing, microstructure, and mechanical properties of ZrB₂-based composites. The main goal was to develop a process that incorporates high strength continuous SiC fiber in a ZrB₂-based matrix. In order to achieve this, the densification, microstructure, and mechanical properties of ZrB₂-ZrSi₂ monolithic ceramics were characterized along with various SiC fiber reinforced ceramic matrix composites (CMCs) utilizing the same matrix.

There were two main areas of study in this thesis. The initial study demonstrated that additions of ZrSi₂ into a ZrB₂ ceramic increases densification at significantly reduced processing temperatures ≤1600ºC). This study revealed …

Development Of An Optimization Model To Determine Sampling Levels, Zlatan Hamzic

Masters Theses

"As the complexity of multi-component products increases the quality of these products becomes increasingly difficult to control. The first step to manufacturing a quality product is making sure that the components of the product meet specifications. Product quality can be controlled through sampling inspection of the components. Two models were developed in this research to determine the optimal sampling levels for incoming lots containing parts for production and assembly of multi-component systems. The main objective of the first model is to minimize the expected cost that is associated with a nonconforming item reaching assembly. In this model the time available …

Protein Aggregation At Solid/Liquid Interfaces: A Monte Carlo Study With Explicit And Implicit Solvent Effects, Rehman Fazeem

Masters Theses

"Metropolis Monte Carlo (MC) simulations were performed with positively charged peptides in aqueous solution to study changes in peptide conformations at solid/liquid interface, and its effects on protein aggregation. Intermediate-resolution diblock model peptide, comprising of 10 units of ALA (non-polar) and LYS (polar) amino acid residues, was used for the simulations. In the first approach to modeling, solvent effects were considered explicitly. The explicit model was then used to study two peptide molecules, in helical structure, at solid/liquid interface. In order to increase the number of peptide molecules in the simulation box, with reduced computational cost, an implicit solvent model …

Stochastic-Optimization Of Equipment Productivity In Multi-Seam Formations, Elijah Adadzi

Masters Theses

"Short and long range planning and execution for multi-seam coal formations (MSFs) are challenging with complex extraction mechanisms. Stripping equipment selection and scheduling are functions of the physical dynamics of the mine and the operational mechanisms of its components, thus its productivity is dependent on these parameters. Previous research studies did not incorporate quantitative relationships between equipment productivities and extraction dynamics in MSFs. The intrinsic variability of excavation and spoiling dynamics must also form part of existing models. This research formulates quantitative relationships of equipment productivities using Branch-and-Bound algorithms and Lagrange Parameterization approaches. The stochastic processes are resolved via Monte …

Characterization Of Rabinal, Guatemala Clay And Development Of An Engineered Surrogate For The Purpose Of Laboratory Study, Lara Anne Hubbel

Masters Theses

"Ceramic pot filters (CPFs) have been proven to be an effective, low cost household water treatment system that are commonly used in third world countries. They are made using local clay, burn out material and colloidal silver or silver nitrate. Challenges faced by researchers include difficulty in acquiring filters from their manufacturing facilities without incurring damage and the cost of shipping. Acquiring the clay material used to make the filters is also difficult due to the cost of shipping and permits necessary to import soil. There have been studies conducted that compared laboratory made CPFs made with native clay and …

Libration Point Orbits Near Small Bodies In The Elliptic Restricted Three-Body Problem, Bharat Mahajan

Masters Theses

"In this study, the feasibility of using libration point orbits to explore small solar system bodies, including asteroids and comets, is considered. A novel design for a small body mission is proposed that makes use of libration point orbits as "parking" orbits. In considering a human exploration mission to asteroids or comets, these "parking" orbits may provide benefits including a safe vantage point for staging/observation, reduced perturbation effects from the nonuniform gravitational field of the body, fewer communication blackouts, ease of guidance and control of a lander on the surface, etc. Because small solar system bodies have extremely low mass …

The Use Of Elemental Powder Mixes In Laser-Based Additive Manufacturing, Rodney Michael Clayton

Masters Theses

"This study examines the use and functionality of laser depositing alloys from mixes of elemental metallic powders. Through the use of laser-based additive manufacturing (LAM), near net-shaped 3-Dimensional metallic parts can be produced in a layer-by-layer fashion. It is customary for pre-alloyed powders to be used in this process. However, mixes of elemental powders can be used to produce alloys that are formed during the deposition process. This alternative technique requires that the elemental powders adequately mix during deposition for a homogeneous deposit to be produced. Cost savings and versatility are among several of the advantages to using elemental powder …

Computational Fluid Dynamics Flow Comparison Between Openhole Sleeve And Plug-And-Perf Completion In A Hydraulic Fractured Horizontal Well, Viriyah Theppornprapakorn

Masters Theses

"Multi-stage hydraulic fracture completions in horizontal wells have facilitated economic development of natural gas from unconventional and tight gas reservoirs.Industry has relied on two horizontal multi-stage completion technologies: cemented and perforated liner or Plug-and-perf method and Openhole Sleeve Multi-stage method. Each method has its own advantages and disadvantages. However, one of the most important questions is which method yields better gas production? Computation fluid dynamics (CFD) is a powerful tool for solving complex fluid flow problems. In well completion design, CFD plays a significant role aiding the completion engineers on making decision on well completion methods. In this study, a …

Wideband Characterization Of Printed Circuit Board Materials Up To 50 Ghz, Aleksei Rakov

Masters Theses

"A traveling-wave technique developed a few years ago in the Missouri S&T EMC Laboratory has been employed until now for characterization of PCB materials over a broad frequency range up to 30 GHz. This technique includes measuring S-parameters of the specially designed PCB test vehicles. An extension of the frequency range of printed circuit board laminate dielectric and copper foil characterization is an important problem. In this work, a new PCB test vehicle design for operating up to 50 GHz has been proposed. As the frequency range of measurements increases, the analysis of errors and uncertainties in measuring dielectric properties …

Manufacturing And Characterization Of Polyurethane Based Sandwich Composites, Stephen Robert Hawkins

Masters Theses

"Composite sandwich structures have been extensively employed in aerospace structures, ship building, infrastructure, etc. due to their light weight and high strength to weight ratio. The understanding of their behavior under impact and environmental conditions is extremely important for the design and manufacturing of these engineering structures since these problems are directly related to structural integrity and safety requirements. Vacuum assisted resin transfer molding (VARTM) is one of the commonly used low cost composite manufacturing processes. Polyurethane (PU) resin system has been observed to have better mechanical properties and higher impact strength when compared to conventional resin systems such as …