Engineering Commons^™

Capacitor Switching Transient Modeling And Analysis On An Electrical Utility Distribution System Using Simulink Software, Durga Bhavani Mupparty

University of Kentucky Master's Theses

The quality of electric power has been a constant topic of study, mainly because inherent problems to it can bring great economic losses in industrial processes. Among the factors that affect power quality, those related to transients originated from capacitor bank switching in the primary distribution systems must be highlighted. In this thesis, the characteristics of the transients resulting from the switching of utility capacitor banks are analyzed, as well as factors that influence there intensities. A practical application of synchronous closing to reduce capacitor bank switching transients is presented. A model that represents a real distribution system 12.47kV from …

Global Change Reactive Background Subtraction, Edwin Premkumar Sathiyamoorthy

University of Kentucky Master's Theses

Background subtraction is the technique of segmenting moving foreground objects from stationary or dynamic background scenes. Background subtraction is a critical step in many computer vision applications including video surveillance, tracking, gesture recognition etc. This thesis addresses the challenges associated with the background subtraction systems due to the sudden illumination changes happening in an indoor environment. Most of the existing techniques adapt to gradual illumination changes, but fail to cope with the sudden illumination changes. Here, we introduce a Global change reactive background subtraction to model these changes as a regression function of spatial image coordinates. The regression model is …

Synthesis And Characterization Of P-Type Copper Indium Diselenide (Cis) Nanowires Embedded In Porous Alumina Templates, Sri Harsha Moturu

University of Kentucky Master's Theses

This work focuses on a simple template assisted approach for fabricating I-III-VI semiconductor nanowire arrays. Vertically aligned nanowires of p-CIS of controllable diameter and thickness are electrodeposited, from an acidic electrolyte solution, inside porous aluminum templates using a three electrode set up with saturated calomel electrode as the reference. AAO template over ITO-glass was used as starting template for the device fabrication. The deposited CIS is annealed at different temperatures in a reducing environment (95% Ar+ 5% H₂) for 30 minutes. X-ray diffraction of the nanowires showed nanocrystalline cubic phase structures with a strong orientation in the <112> direction. …

Simulation And Control Of A Quadrotor Unmanned Aerial Vehicle, Michael David Schmidt

University of Kentucky Master's Theses

The ANGEL project (Aerial Network Guided Electronic Lookout) takes a systems engineering approach to the design, development, testing and implementation of a quadrotor unmanned aerial vehicle. Many current research endeavors into the field of quadrotors for use as unmanned vehicles do not utilize the broad systems approach to design and implementation. These other projects use pre-fabricated quadrotor platforms and a series of external sensors in a mock environment that is unfeasible for real world use. The ANGEL system was designed specifically for use in a combat theater where robustness and ease of control are paramount. A complete simulation model of …

Evaluation Of Intelligibility And Speaker Similarity Of Voice Transformation, Anusha Raghunathan

University of Kentucky Master's Theses

Voice transformation refers to a class of techniques that modify the voice characteristics either to conceal the identity or to mimic the voice characteristics of another speaker. Its applications include automatic dialogue replacement and voice generation for people with voice disorders. The diversity in applications makes evaluation of voice transformation a challenging task. The objective of this research is to propose a framework to evaluate intentional voice transformation techniques. Our proposed framework is based on two fundamental qualities: intelligibility and speaker similarity. Intelligibility refers to the clarity of the speech content after voice transformation and speaker similarity measures how well …

Bench-Scale, Multifilament Spinning Conditions Effect On The Structure And Properties Of Polyacrylonitrile Precursor Fiber, Elizabeth Ashley Morris

University of Kentucky Master's Theses

Due to its unique characteristics, carbon fiber is one of the leading materials for light weight, high strength and stiffness applications in composite materials. The development of carbon fibers approaching theoretical strengths and stiffness is a continuing process which has led to improved mechanical and physical properties over the recent years. Improvements in carbon fiber properties are directly dependent on the quality of the precursor fiber. Research and development of PAN precursor fiber requires extensive experimentation to determine how processing conditions affect the structure and properties of the precursor fibers. Therefore, it is the goal of this thesis to analyze …

High Speed Continuous Thermal Curing Microfabrication System, Franklin Dibartolomeo

University of Kentucky Master's Theses

Rapid creation of devices with microscale features is a vital step in the commercialization of a wide variety of technologies, such as microfluidics, fuel cells and self-healing materials. The current standard for creating many of these microstructured devices utilizes the inexpensive, flexible material poly-dimethylsiloxane (PDMS) to replicate microstructured molds. This process is inexpensive and fast for small batches of devices, but lacks scalability and the ability to produce large surface-area materials. The novel fabrication process presented in this paper uses a cylindrical mold with microscale surface patterns to cure liquid PDMS prepolymer into continuous microstructured films. Results show that this …

Effect Of A Silicon Tip On Absorption Cross Section, Field Enhancement, And Localized Surface Plasmon Resonance Of Different Sized Gold Nanoparticles Under Evanescent Wave Illumination, Gazi Mostafa Huda

University of Kentucky Master's Theses

We have numerically investigated the influence of a nanoscale silicon tip in proximity to an illuminated gold nanoparticle. We describe how the position of the high-permittivity tip and the size of a nanoparticle impact the absorption, peak electric field and surface plasmon resonance wavelength under different illumination conditions. We detail the finite element method (FEM) approach we have used for this, whereby we specify a volume excitation field analytically and calculate the difference between this source field and the total field (i.e., scattered-field formulation). We show that a nanoscale tip can locally enhance the absorption of the particle as well …

The Effect Of Loose Mix Aging On The Performance Properties Of Warm Asphalts, Thomas Martin Clements

University of Kentucky Master's Theses

Recent improvements in warm mix asphalt technologies have spurred an aggressive adoption of these new practices within the asphalt paving industry. Concerns have arisen among federal and state agencies about the effects of this line of products on the performance of asphalt pavements. An investigation of the effects of lowering mixing, aging and compactions temperatures while varying the loose mix aging time was performed. Hamburg Wheel Tracking, Flow Number, Dynamic Modulus and Fracture Energy testing were used to evaluate mechanistic properties of the materials.

Rotate And Hold And Scan (Rahas): Structured Light Illumination For Use In Remote Areas, Eli Ross Crane

University of Kentucky Master's Theses

As a critical step after the discovery of material culture in the field, archaeologists have a need to document these findings with a slew of different physical measurements and photographs from varying perspectives. 3-D imaging is becoming increasingly popular as the primary documenting method to replace the plethora of tests and measurements, but for remote areas 3-D becomes more cumbersome due to physical and environmental constraints. The difficulty of using a 3-D imaging system in such environments is drastically lessened while using the RAHAS technique, since it acquires scans untethered to a computer. The goal of this thesis is to …

Influence Of Tissue Absorption And Scattering On Diffuse Correlation Spectroscopy Blood Flow Measurements, Daniel Irwin

University of Kentucky Master's Theses

This investigation evaluates the influences of optical property assumptions on nearinfrared diffuse correlation spectroscopy (DCS) flow index measurements. Independent variation is induced in optical properties, absorption coefficient (μ_a) and reduced scattering coefficient (μ_s’), of liquid phantoms with concurrent measurements of flow indices. A hybrid instrument is incorporated consisting of a dual-wavelength (785 and 830 nm) DCS flow device to obtain flow indices and a frequency-domain tissue-oximeter for optical properties. Flow indices are calculated with measured μ_a and μ_s’ or assumed constant μ_a and μ_s’. Inaccurate μ_s’ assumptions produced …

Gaze Estimation Using Sclera And Iris Extraction, Prashanth Rao Periketi

University of Kentucky Master's Theses

Tracking gaze of an individual provides important information in understanding the behavior of that person. Gaze tracking has been widely used in a variety of applications from tracking consumers gaze fixation on advertisements, controlling human-computer devices, to understanding behaviors of patients with various types of visual and/or neurological disorders such as autism. Gaze pattern can be identified using different methods but most of them require the use of specialized equipments which can be prohibitively expensive for some applications. In this dissertation, we investigate the possibility of using sclera and iris regions captured in a webcam sequence to estimate gaze pattern. …

An Investigation Of The Reynolds Number Dependence Of The Near-Wall Peak In Canonical Wall Bounded Turbulent Channel Flow, Bahareh Estejab

University of Kentucky Master's Theses

An experimental investigation into fully developed high aspect ratio channels was undertaken. A review of the literature reveals that there is a need for accurate measurement of the inner peak value of streamwise turbulence intensity despite the large number of studies already completed. The scattered data on this subject could be attributed either to insufficient channel size (aspect ratio or length) or to hot-wire spatial filtering.

A new, high quality, channel flow facility was designed and constructed, considering the most recent geometric limitation provided in the literature. To obtain accurate results, data were acquired using hot-wire probes with constant viscous-scale …

Experimental Flow Visualization For Corrugated Airfoils At Low Reynolds Number Including Development Of A Pitch And Plunge Fixture, Jeremy Ryan Sparks

University of Kentucky Master's Theses

Micro Air Vehicles (MAV’s) have small size and extreme maneuverability which makes them ideal for surveillance. Propulsion mechanisms include propellers, rotors, and flapping airfoils. Flapping motions, along with biologically-inspired wing profiles, are of interest due to their use of natural physics. Corrugated airfoil structures appears to have poor aerodynamic performance at higher Reynolds numbers, but serve well at Re<10,000. Understanding flow structures around corrugated profiles and comparing them to a standard airfoil will aid in understanding how these corrugated profiles perform well and have been adopted by some of nature’s most acrobatic flyers. Motivation for this investigation is to compare static flow visualizations of corrugated profiles to a standard National Advisory Committee for Aeronautics (NACA) airfoil from low to high angles of attack and further observe flow structure development of a pitching and plunging flat plate at a Re<10,000 and a Strouhal number relevant to natural fliers. The static visualization was conducted at Re=1,000 with a NACA 0012 airfoil and two corrugated models. The Pitch and Plunge Fixture (PPF) developed was constructed by simplifying flapping wings as a two degree of freedom motion in plunge (translation) and pitch (rotation). Results obtained from the PPF were compared with a numerical simulation.

The Effect Of Practice On Eye Movements In The 1/D Paradigm, Will Seidelman

University of Kentucky Master's Theses

Previous studies have demonstrated that observers may ignore highly salient feature singletons during a conjunction search task through focusing the attentional window (Belopolsky, Zwaan, Theeuwes, & Kramer, 2007), or by the suppression of bottom-up information (Treisman & Sato, 1990). In the current study, observers’ eye movements were monitored while performing a search task in which a feature singleton was present and corresponded with the target at a chance level. With practice, observers were less likely to make an initial saccade toward the singleton item, but initial saccades directed at the target were likely throughout. Results demonstrate that, in an effort …

Developing A Time And Motion Study For A Lean Healthcare Environment, Michael Winston Patton Jr.

University of Kentucky Master's Theses

This thesis outlines the development of a standard methodology for performing a time and motion study in a lean healthcare environment. Time and motion studies have been used in healthcare environments in the past, however they have nearly all been exclusive to a particular healthcare enterprise. To develop the time and motion study methodology, a study was designed to examine how resident doctors spend their time. This study was performed in response to coming changes in the work hours for all residents. Once the methodology was developed, trial observations were conducted. The data from these observations was analyzed to determine …

Perch Landing Maneuvers And Control For A Rotating-Wing Mav, Jonathan Louis Lubbers

University of Kentucky Master's Theses

This thesis addresses flight control of the perch landing maneuver for micro-aerial vehicles. A longitudinal flight model is constructed for a pigeon-sized aircraft. In addition to a standard elevator control surface, wing-rotation also considered as a non-standard actuator for increasing low-speed aerodynamic braking. Optimal state and control trajectories for the perch landing maneuver are computed using commercial software. A neighboring optimal control law is then developed and implemented in a set of flight simulations. Simulations are run with both a quasisteady and an unsteady aerodynamic model. The effectiveness of wing rotation and of the neighboring optimal control law is discussed, …

Modeling And Optimization To Evaluate Sustainability Performance Of Customizable Product Service Systems, Ken Harsha Tilakaratne Wijekoon

University of Kentucky Master's Theses

The aim of this thesis is to present a new methodology to evaluate and optimize sustainability of customizable product-service systems while ensuring economic, environmental and societal constraints are also satisfied. Activities across the total product lifecycle are considered to develop a model that evaluates closed-loop flow, while being monitored through the growth, maturity and decline stages of the product to provide a comprehensive analysis. A novel method to evaluate the customer satisfaction is also presented. The research considers a modular product where customization can be achieved by selecting from alternatives while ensuring the compatibility between these alternatives. A manufacturer will …

Mechanical Characterizations Of Environmentally Conditioned Shape Memory Polymers For Reconfigurable Aerospace Structures, Jared T. Fulcher

University of Kentucky Master's Theses

Shape memory polymers (SMPs) have been candidate materials for morphing applications. However, the SMPs have not been fully tested to work in relevant environments required for Air Force missions. In this study, an epoxy-based SMP was separately exposed to moisture, lubricating oil and UV radiation, which are simulated service environments designed to be reflective of anticipated performance requirements. The thermomechanical properties and shape memory effects were studied by using novel high-temperature nanoindentation technique. Results show that environmental conditions have affected the glass transition temperature and mechanical properties of the SMPs. In most cases, the conditioned SMPs exhibited higher elastic moduli …

Investigations Of Cuinte2 / Cds & Cdte / Cds Heterojunction Solar Cells, Venkatesh Gutta

University of Kentucky Master's Theses

Thin film solar cells of Copper Indium Telluride and Cadmium Sulfide junctions were fabricated on plain ITO glass slides and also on those coated with intrinsic Tin Oxide. CdS was deposited through chemical bath deposition and CIT by electrodeposition. Both compounds were subjected to annealing at temperatures between 350°C and 500°C which produced more uniform film thicknesses and larger grain sizes. The CIT/ CdS junction was characterized after performing XRD and spectral absorption of individual compounds.

Studies were also made on CdS / CdTe solar cells with respect to effect of annealing temperatures on open circuit voltages. NP acid etch, …

Compact Vision System For Monitoring Of 3d Weld Pool Surface In Pipe Welding, Alexander Phillip Maroudis

University of Kentucky Master's Theses

Human welders have long been able to monitor a weld pool and adjust welding parameters accordingly. Automated welding robots can provide consistent movement during the welding process, but lack the ability to monitor the weld pool. A vision system attached to the welding robot could provide a way to monitor the weld pool substantially faster than a human being. Previous vision systems to monitor weld pool surfaces have been developed, but their uses are limited since the system is fixed in place. The compact vision system developed in this research attaches directly to the welding torch, which provides no limitations …

Evaluating The Effectiveness Of Peak Power Tracking Technologies For Solar Arrays On Small Spacecraft, Daniel Martin Erb

University of Kentucky Master's Theses

The unique environment of CubeSat and small satellite missions allows certain accepted paradigms of the larger satellite world to be investigated in order to trade performance for simplicity, mass, and volume. Peak Power Tracking technologies for solar arrays are generally implemented in order to meet the End-of-Life power requirements for satellite missions given radiation degradation over time. The short lifetime of the generic satellite mission removes the need to compensate for this degradation. While Peak Power Tracking implementations can give increased power by taking advantage and compensating for the temperature cycles that solar cells experience, this comes at the expense …

Artificial Neural Network Based Fault Location For Transmission Lines, Suhaas Bhargava Ayyagari

University of Kentucky Master's Theses

This thesis focuses on detecting, classifying and locating faults on electric power transmission lines. Fault detection, fault classification and fault location have been achieved by using artificial neural networks. Feedforward networks have been employed along with backpropagation algorithm for each of the three phases in the Fault location process. Analysis on neural networks with varying number of hidden layers and neurons per hidden layer has been provided to validate the choice of the neural networks in each step. Simulation results have been provided to demonstrate that artificial neural network based methods are efficient in locating faults on transmission lines and …

Development Of A Semi-Automated Tobacco Stripping Machine Utilizing String Trimmers, Robert George Sperry

University of Kentucky Master's Theses

Conventional stripping of burley tobacco is labor intensive and typically requires 50 to 75 worker hours per acre (wkr•hr/ac). The goal of the project was to reduce labor by optimizing leaf removal by string trimmer heads using combinations of strings lengths and motor speeds. In tests conducted on a single grade, all leaves outside the grade were removed by hand. Plants were run through the machine for sting lengths of 5, 7 and 9 inches and associated motor speeds which were monitored and recorded. Stripping efficiencies were calculated for each plant and collectively for each set of four plants. The …

Fabrication Of Mwcnt Based Gas Sensor Using Site-Selective Growth Of Nanotubes On Gold Patterned Silicon Oxide Substrate, Srikanth Durgamahanty

University of Kentucky Master's Theses

Growth confinement techniques for multi walled carbon nanotubes on Au/SiO₂ surfaces was studied and incorporated into a gas sensor design. A device framework was conceived and a sensor was built to achieve this structure. The fabrication results were analyzed using scanning electron microscopy which confirmed the achievement of highly site-selective growth of carbon nanotubes, exclusively between the interdigitated electrodes. The sensor was then evaluated for its capacitance and conductance response when exposed to NO₂ gas. Variation in sensitivities with frequency and flow rate were analyzed. A mathematical model was derived for such a device structure and the predictions …

Initial Design, Manufacture, And Testing Of A Cubelab Module Frame For Biological Payloads Aboard The International Space Station, Twyman Samuel Clements

University of Kentucky Master's Theses

This thesis investigates the design of a CubeLab Module frame to facilitate biological research aboard the International Space Station (ISS). With the National Laboratory designation of the ISS by the United States Congress the barriers for use of the facility have been lowered for commercial and academic entities, allowing greater volume and diversity in the research that can be done. Researchers in biology and other areas could benefit from development and adoption of a plug-and-play payload containment system for use in the microgravity/space environment of the ISS. This research includes design and analysis of such a system. It also includes …

Constrained Volume Packing Of Deployable Wings For Unmanned Aircraft, Turner John Harris

University of Kentucky Master's Theses

UAVs are becoming an accepted tool for sensing. The benefits of deployable wings allow smaller transportation enclosures such as soldier back packs up to large rocket launched extraterrestrial UAVs. The packing of soft inflatable wings and Hybrid inflatable with rigid section wings is being studied at the University of Kentucky. Rigid wings are volume limited while inflatable wings are mass limited. The expected optimal wing design is a hybrid approach. Previous wing designs have been packed into different configurations in an attempt to determine the optimal stowed configurations. A comparison of rigid, hybrid, and inflatable wings will be presented. Also …

Influence Of Fan Operation On Fan Assessment Numeration System (Fans) Test Results, Gabriela Munhoz Morello

University of Kentucky Master's Theses

The use of velocity traverses to measure in-situ air flow rate of ventilation fans can be subject to significant errors. The Fan Assessment Numeration System (FANS) was developed by the USD-ARS Southern Poultry Research Laboratory and refined at the University of Kentucky to measure air flow of fans in-situ. The procedures for using the FANS unit to test fans in-situ are not completely standardized. This study evaluated the effect of operating fan positions relative to the FANS unit for ten 1.22 m diameter fans in two types of poultry barns, with fans placed immediately next to each other and …

Evaluation Of Mechanical Proerties And Effective Thickness Of The Interfaces By Finite Element Analysis, Sesha Spandana Pulla

University of Kentucky Master's Theses

The nanoindentation technique has been used to identify the interfaces between dissimilar materials and subsequently to evaluate the physical and mechanical properties across the interfaces. The interfaces could represent the interface (transition face) between oxidized and unoxidized polymers, the interface between rigid fiber and polymer matrix, or other similar situations. It is proposed to use a nanoindenter equipped with small spherical tip to indent across the interfaces of dissimilar materials. The proposed method has been validated by conducting a large number of virtual experiments through 3-dimensional finite element simulations, by varying the properties of the two dissimilar materials, including various …

Particulate Organic Carbon Fate And Transport In A Lowland, Temperate Watershed, William Isaac Ford Iii

University of Kentucky Master's Theses

Small lowland agricultural systems promote conditions where benthic biological communities can thrive. These biogeochemical processes have significant impacts on terrestrial ecosystem processes including POC flux and fate, nutrient balances, water quality budges, and aquatic biological functioning. Limited information is available on coupled biological and hydrologic processes in fluvial systems. This study investigates the mixture of biological and hydrologic processes in the benthic layer in order to understand POC cycling in the South Elkhorn system. Further, comprehensive modeling of POC flux in lowland systems has not been performed previously and the behavior of potentially controlling variables, such as hydrologic forcing and …