Engineering Commons^™

Fpga-Based Image Analysis System For Cotton Classing, Muhammad Imran Sharafat

Masters Theses

The design and implementation of an FPGA (field-programmable gate array) based image analysis system was undertaken to replace an older system whose components have become obsolete. Video from an analog camera is digitized by a video decoder. The data from the video decoder is stored in memory and then processed using an FPGA. The results are then transmitted over a universal serial bus (USB) to a host personal computer for additional processing. The system also controls the timing of a flash to correctly capture the images; it measures color and reflectance and is used to classify the quality of raw …

A Longest-Queue-First Signal Scheduling Algorithm With Quality Of Service Provisioning For An Isolated Intersection, Richard James Wunderlich

Masters Theses

In today's fast-paced society, the need to travel using automobiles is increasingly important. Aside from the road itself, the intersection is the most basic unit of a traffic system. As such, controlling the flow of traffic through intersections in an efficient manner has become a task of the utmost importance. The signal-scheduling algorithm described in this thesis is designed for just such a task. Concepts are drawn from the field of packet switching in computer networks and are applied to the traffic control problem. The method proposed utilizes a maximal weight matching algorithm to minimize the queue sizes at each …

A Study Of The Beginning Boundary Layer Influence On The Flow Field About A Two-Dimensional Automotive Model, Jonathan Gabriel Ford

Masters Theses

An experimental investigation was performed to analyze the beginning boundary layer produced on the floor of a subsonic wind tunnel and its influence on the flow field about a two-dimensional automotive model. Hot film anemometer measurements were taken in the test section of the wind tunnel operating under various inlet configurations. The use of a splitter plate and modifications to the contour of the inlet to the wind tunnel were then studied to find their affects on the height of the boundary layer in the wind tunnel test section. Finally, a 2-D automotive model was constructed with pressure taps along …

Evaluation Of Losses In Hid Electronic Ballast Using Silicon Carbide Mosfets, Lakshmi Reddy Gopi Reddy

Masters Theses

HID lamps are used in applications where high luminous intensity is desired. They are used in a wide range of applications from gymnasiums to movie theatres, from parking lots to indoor aquaria, from vehicle headlights to indoor gardening. They require ballasts during start-up and also during operation to regulate the voltage and current levels. Electronic ballasts have advantages of less weight, smooth operation, and less noisy over electromagnetic ballasts. A number of topologies are available for the electronic ballast where control of power electronic devices is exploited to achieve the performance of a ballast for lighting. A typical electronic ballast …

Investigations On Hydrocyclones For The Spallation Neutron Source, Lee Henry Hosack

Masters Theses

The hydrocyclone is commonly used to separate oil from water, and particulates from fluid streams in various process industries. Two-fluid hydrodynamic theory is used here to develop a model for hydrocyclone performance in the application of separation of helium bubbles larger than 30 micron in diameter from liquid mercury at system pressure near 1 bar. The application is related to high power liquid metal target development for proton beams used in spallation neutron sources.

Artificial Neural Network For Spectrum Unfolding Bonner Sphere Data, Jia Hou

Masters Theses

The use of Bonner Sphere Spectrometer (BSS) is a well-established method of measuring the energy distribution of neutron emission sources. The purpose of this research is to apply the Generalized Regression Neural Network (GRNN), a kind of Artificial Neural Network (ANN), to predict the neutron spectrum using the count rate data from a BSS. The BSS system was simulated with the MCNP5 Monte-Carlo code to calculate the response to neutrons of different energies for each combination of thermal neutron detector and polyethylene sphere. One hundred and sixty-three different types of neutron spectra were then investigated. GRNN Training and testing was …

Fabrication And A Study On The Wetting Properties Of Nanostructured Surfaces, Meenaa Kalyanaraman

Masters Theses

Fluid behavior at the microscale exhibits large surface to volume ratios increasing the significance of interfacial phenomena. We have studied two microfluidic phenomena that utilize interplay between microstructure and chemical composition. The first one causes liquid droplets to roll off from surfaces with a very high contact angle. This phenomenon is called superhydrophobic behavior, can be controlled by several tuning parameters. The second one changes the wettability of liquids on a dielectric coated surface with electric potential. The experimental studies were done by first fabricating an ordered array of glass nanocones. Fiber drawing and differential glass etching processes were used …

Estimation Of Surface Temperature And Heat Flux Using Embedded Thermocouples, Jeffrey Daniel King

Masters Theses

This thesis investigates several new methods for estimating surface temperature and heat flux based on thermocouples embedded within the interior of a test article. The test apparatus was a Mach 2 axisymmetric rocket nozzle with probes embedded at depths of 1/8” and 1/4” from the inner surface of the nozzle at the throat and exit locations. Three methods for numerically estimating temperature and heat flux at the surface of the nozzle were considered: a one-thermocouple slab-coordinate method, a two-thermocouple slabcoordinate method, and a finite-element analysis (FEA) based on a one-dimensional cylindrical coordinate method. Comparisons between the methods, as well as …

Universal Voltage Rate Sensor Interface, Jayanth Chakradhar Kruttiventi

Masters Theses

Measurement of heat flux is required in many aerospace and heat treatment applications. Temperature data collected at embedded sites are noisy especially when measurements are taken in hostile environments. The predicted heat flux, when based on the rate of change of temperature, is more accurate than using temperature data as the latter data form is ill-posed. In the context of heat flux prediction, calculating the rate of change of temperature involves differentiation, which is the primary source of ill-posed effects.

This work involves developing a universal voltage rate sensor interface that minimizes these effects and also improves the signal-to-noise ratio. …

Applied Fourier Transform Near-Infrared Techniques For Biomass Compositional Analysis, Lu Liu

Masters Theses

A new method for rapid chemical analysis of lignocellulosic biomass was developed using Fourier transform near-infrared (FT-NIR) spectroscopic techniques. The new method is less time-consuming and expensive than traditional wet chemistry. A mathematical model correlated FT-NIR spectra with concentrations determined by wet chemistry. Chemical compositions of corn stover and switchgrass were evaluated in terms of glucose, xylose, galactose, arabinose, mannose, lignin, and ash. Model development evaluated multivariate regressions, spectral transform algorithms, and spectral pretreatments and selected partial least squares regression, log(1/R), and extended multiplicative signal correction, respectively. Chemical composition results indicated greater variability in corn stover than switchgrass, especially among …

Cfd Characterization Of Automotive Inflator-Generated Gas Distribution Process, Scott Alan Lusted

Masters Theses

This thesis outlines the application of Computational Fluid Dynamics to the characterization of the gas distribution process inherent in automotive gas generators. The gas distribution process is important to understand as it greatly influences the overall performance of the device and its competitiveness in the marketplace. Presently, there is limited analysis that has been conducted on the gas generators. The current method involves conducting experiments using prototype hardware and high speed video to capture the flow field. This approach has proven to be useful; however, it lacks the ability to thoroughly study the fluid dynamics. Furthermore, the analysis has to …

Characterizing Groundwater-Surface Water Interactions In Great Smoky Mountains National Park Using Hydrologic, Geochemical & Isotopic Data, Amanda Marie Mckenna

Masters Theses

Groundwater-surface water interactions can substantially influence the quality of surficial water bodies and are thus important when investigating ecological health of and climate change impacts on an area. However, data collection can be hindered when the location is remote and/or legally protected. This paper presents a methodology to implement minimallyinvasive field techniques at a remote and protected location that allows preliminary identification of the relationship between groundwater and surface water. Great Smoky Mountains National Park was selected as the study area as it is subjected to some of the highest rates of acid deposition in the country. Ecological damage is …

Analysis Of Electrical Activity Of The Core Muscles Exposed To Whole-Body Vibrations While Driving A Tractor Trailer Using Electromyography Device, Harini Mangavelli

Masters Theses

Lower back disorders are observed to be the most significant problem for most of the industrial workers who operate commercial vehicles. A person sitting can have 40% higher load on the lumbar spine than when standing. Human core muscles related to spinal movement respond to rapid potential motions related to external acceleration inputs of vibration in order to control body posture, the increased muscle tension can result in muscle fatigue. The over use of muscles, vibration exposure combined with dehydration of spine and long term seating can lead to lower back pain and axial discomfort to the drivers. Electromyography (EMG) …

Inverse Kinematics Based On Fuzzy Logic And Neural Networks For The Wam-Titan Ii Teleoperation System, Joong-Kyoo Park

Masters Theses

The inverse kinematic problem is crucial for robotics. In this paper, a solution algorithm is presented using artificial intelligence to improve the pseudo-inverse Jacobian calculation for the 7-DOF Whole Arm Manipulator (WAM) and 6-DOF Titan II teleoperation system. An investigation of the inverse kinematics based on fuzzy logic and artificial neural networks for the teleoperation system was undertaken. Various methods such as Adaptive Neural-Fuzzy Inference System (ANFIS), Genetic Algorithms (GA), Multilayer Perceptrons (MLP) Feedforward Networks, Radial Basis Function Networks (RBF) and Generalized Regression Neural Networks (GRNN) were tested and simulated using MATLAB. Each method for identification of the pseudo-inverse problem …

Two-Phase Hydraulics State Identification Using Linear And Non-Linear Time Series Analysis: Distillation Column Flooding Sensor, Alok Maheshbhai Patel

Masters Theses

A novel sensor to detect and predict hydraulic flooding in the distillation column was developed in this research. High speed (1000 Hz) differential pressure data sets were collected across distillation trays. The distillation column at University of Tennessee, Knoxville (UTK) was the main research and demonstration site. The UTK column is 9 inches inside diameter, has 4 trays each of a different type not counting the reboiler. Many data sets were collected synchronously across the top tray (sieve tray) and across the next tray (bubble cap) from the top. Flooding always occurred on the sieve tray. To prove the application …

Analysis And Characterization Of A Sige Bicmos Low Power Operational Amplifier, Archana Yarlagadda

Masters Theses

Integrated circuit design for space applications can require radiation immunity, cryogenic operation and low power consumption. This thesis provides analysis and characterization of a SiGe BiCMOS low power operational amplifier (op amp) designed for lunar surface applications. The op amp has been fabricated on a commercially available 0.35-micron Silicon-Germanium (SiGe) BiCMOS process. The Heterojunction bipolar transistors (HBT) available in the SiGe process have been used in this op amp to take advantage of the total ionizing dose (TID) irradiation immunity and superb cryogenic operation, along with PMOS devices that show better TID immunity than their NMOS counterparts. The key features …

A Generalized Hamiltonian-Based Algorithm For Rigorous Nonequilibrium Molecular Dynamics Simulation In The Nvt Ensemble, Joseph Gerald Leo Rajkumar

Masters Theses

Using a recently developed, methodical, Hamiltonian-based procedure, we derive rigorous algorithms for nonequilibrium molecular dynamic (NEMD) simulation in the NVE and NVT ensembles. We demonstrate that the equivalence of the kinetic temperature and configurational temperatures that exists at equilibrium is maintained in nonequilibrium states, given the proper nonequilibrium expression (in the microcanonical ensemble). Specifically, we apply the procedure to the p-SLLOD algorithm, which allows for rigorous NEMD simulation in the presence of an arbitrary, externally imposed flow field. The resulting algorithms are general in that they apply in the presence or absence of external fields in addition to the imposed …

Image And Sieve Analysis Of Biomass Particle Sizes And Separation After Size Reduction, Yuechuan Yang

Masters Theses

Improved physical separation of biomass concentrates higher-value components, returns unused plant components to the soil, and provides a more efficient platform for downstream industrial users. Sieving and Image Analysis (IA) were studied to evaluate biomass particle sizes, particle size distribution, and potential separation of biomass materials. Switchgrass, wheat straw, and corn stover were used in the study. Particles prepared by a knife mill equipped with various screen sizes were subject to sieving test and IA. Results showed that all three biomass materials would be analyzed using the fast, easy and accurate IA. Biomass particle physical properties, such as length, width, …

Development Of The Telemetrical Intraoperative Soft Tissue Tension Monitoring System In Total Knee Replacement With Mems And Asic Technologies, Gary To

Masters Theses

The alignment of the femoral and tibial components of the Total Knee Arthoplasty (TKA) is one of the most important factors to implant survivorship. Hence, numerous ligament balancing techniques and devices have been developed in order to accurately balance the knee intra-operatively. Spacer block, tensioner and tram adapter are instruments that allow surgeons to qualitatively balance the flexion and extension gaps during TKA. However, even with these instruments, the surgical procedure still relies on the skill and experience of the surgeon. The objective of this thesis is to develop a computerized surgical instrument that can acquire intra-operative data telemetrically for …

A Standard Cmos Compatible Bandgap Voltage Reference With Post-Process Digitally Tunable Temperature Coefficient, Sam D. Caylor

Masters Theses

An essential element of most robust analog/mixed-signal systems is a stable and precise bandgap voltage reference (BGR). CMOS compatible BGR circuits are generally limited by variability in output drift over temperature due to process variations. In this work a CMOS BGR is developed that provides simple, digitally-controlled post-process (i.e., post fabrication) trimming. The trimming is achieved through MOSFET switches used to adjust a current gain factor for the thermal voltage referenced current within the BGR circuit. This current is proportional to absolute temperature (PTAT). The PTAT current is injected into a series connected resistor and diode to ultimately provide an …

Developing A Technique For Evaluating Weed-Specific Mapping Systems, Philip Brooks Allen

Masters Theses

Federal regulation and public awareness of agricultural chemical use have fueled precision agriculture research for the last decade. An extensive body of research on potential reduction of herbicide inputs by automated patch-spraying or site-specific management has developed. Two dominant methods have developed for site-specific application of herbicide. Map-based systems use predefined application maps to direct herbicide application and sensor-based systems use real-time weed sensors to identify and treat weeds as the sprayer moves through the field. Weed maps, generated for map-based application of herbicide are beneficial for out-of-field decision-making but are labor intensive to create and sensitive to many types …

Uncertainty Analysis Of Advanced Fuel Cycles To Control Plutonium Inventories, Thomas Christopher Anderson

Masters Theses

This paper assesses the uncertainty associated with the utilization and implementation of advanced fuel cycles to control plutonium inventories. The specific fuel cycles investigated are a partially closed cycle utilizing MOX reactors and completely closed one-tier fuel cycles utilizing fast reactors. Multiple methods for assessing these uncertainties were utilized. A scenario approach that varied the time and number of the implementation of the advanced reactors was used. It was found that the implementation of 3 FR/yr with a CR of 0.5 could reduce the amount of Pu by over 36% in reference to building 3 LWR/yr. In addition to reducing …

Investigation Of The Sidewall Boundary Layers In The Bidirectional Vortex Liquid Rocket Engine, Joshua W. Batterson

Masters Theses

To complement previous studies on the bidirectional vortex, we attempt to characterize viscous effects in both the axial and radial directions along the sidewall with standard asymptotic techniques. The actual boundary layer present in the chamber will be a composite of both axial and tangential shearing layers. Since the tangential velocity is completely dominant, we expect the defining characteristics of the composite boundary layer to be congruent with the tangential layer in both thickness and axial invariance. The analytic analysis is outlined first by, the formulation of the boundary layer equations via Prandtl’s method. Next, asymptotic techniques are applied to …

The Development Of Regional Regression Equations For Flood Flow Estimates Of Ungauged Streams In The State Of Arkansas, Stephen Mccall

Civil Engineering Undergraduate Honors Theses

No abstract provided.

Validation Of Adaptive Aeroelastic Finite Element Program For Two Dimensional Flow Past A Suspension Bridge Girder Section Using Unstructured Grids., Shanique Murray

Civil Engineering Undergraduate Honors Theses

No abstract provided.

Ductile Lightweight Concrete For Lightweight Structural Application, Ake Piyamaikongdech

Civil Engineering Theses

This study developed a ductile concrete for precast wall systems which are capable of resisting high wind in excess of 500 mph. The developed concrete mix design consists of sand, cement, glass fiber, and a foaming agent to produce lightweight concrete in the range of 87 pcf (1392 kg/m3) to 90 pcf (1440 kg/m3). A comprehensive testing program for evaluation of the developed concrete material was undertaken. The mix designs were prepared both in the laboratory and in the mix truck with drum capacity of 27 ft3 (0.77 m3), and 177.6 ft3 (5 m3), respectively. The large concrete batches using …

Modeling Unsaturated Soil Response Under Suction-Controlled Multi-Axial Stress States, Arthit Laikram

Civil Engineering Dissertations

In this research work, a novel suction-controlled true triaxial testing apparatus has been developed to test 3-in (7.5-cm) side, cubical specimens of unsaturated soil under controlled-suction states for a wide range of stress paths that are not easily achievable in a conventional cylindrical apparatus. The equipment is a mixed-boundary type of device, with the specimen seated on top of a high-air-entry ceramic disk and between five flexible (latex) membranes on the remaining sides of the cube. The new cell is an upgraded, more elaborate version of the one previously reported by Hoyos (1998), featuring two independent pore-air and pore-water pressure …

The Effect Of Temperature On Fiber Composite Bridge Decks, Mahesh Gajula Nagabhushanam

Civil Engineering Theses

The use of Fiber composite honeycomb structure's as bridge decks gained importance, because of its low light weight and ease of installation. In this study, The Fiber composite bridge decks were subjected to thermal gradients. The Fiber composite bridge decks were fabricated in sizes of 2 feet x 8 feet x .5 feet and 4 feet x 8 feet x .5 feet specimens by Kansas structural composites Inc. The program consisted of 3 specimens of size 2 feet x 8 feet x .5 feet with ribs oriented along longitudinal direction, 3 specimens of size 2 feet x 8 feet x …

Localization Of Biliary Tree Structures By Use Of Photon Diffusion Models, Dharmendra Nadkar

Bioengineering Theses

A novel computational methodology is proposed for the intraoperative localization of biliary tree structures by means of spectrally resolved near-infrared reflectance measurements. As these structures are embedded in fatty tissue, they cannot be visualized directly, which results in inadvertent injuries during a cholecystectomy operation. Localizing the biliary tree intraoperatively is therefore an important clinical problem. Successful clinical implementation of an imaging system which could attain this goal would reduce surgical time, improve patient safety, and minimize the risk of complications and expenses attributable to the current standard practice of intraoperative cholangiography. It is hoped that the work presented here will …

Trends Of Vehicular Emissions For Clean Air Associates Precombustion Retrofit Device, Jaya Vani Nagireddi

Civil Engineering Theses

The research study objective was to find if there was any reduction in onboard exhaust emissions from a light duty passenger car (2007 Dodge Charger) with a Clean Air Catalytic Converter manufactured by Clean Air Associates, Inc. The research was conducted by the Civil and Environmental Engineering Department, University of Texas at Arlington as part of the North Central Texas Council of Governments Aftermarket Technology and Fuel Additive Research Program. Initially, emissions of pollutants were measured without the Clean Air Associates' retrofit device, called Baseline testing. A Horiba OBS-1300 On-Board System measured concentrations of the pollutants NOx, CO, CO2 and …