Engineering Commons^™

Performance Specification For Tennessee Bridge Decks, Brian Ray Buchanan

Masters Theses

In today’s world of ever increasing demand on a weakening infrastructure, concentration is being firmly placed on increasing the sustainability of that infrastructure. Tennessee’s bridges and the concrete decks, on which the public travels, require a large part of the state’s infrastructure spending. Research has shown the current durability standards of Tennessee’s bridge decks could be significantly improved which would both increase service life and reduce maintenance costs of these structures. This research concentrates on greatly increasing the lifespan of these bridge decks, throughout the state, through an improved construction specification which will encourage the increased use of supplementary cementitious …

Short Distance Ground Wave Propagation Modeling In Irregular And Forested Environments, Zachary Michael Crane

Masters Theses

A model for the phase of a ground wave propagating over irregular and forested terrain has been developed and tested for a transmission system operating at 3.315 MHz.

In this model, the time delay induced beyond that of the standard velocity of radio waves in air is modeled as a combination of 3 effects: the finite conductivity of the earth, the irregularity of the terrain over which the wave is propagating, and the forestation of the terrain.

The finite conductivity model is based on a small curvature formula developed by Van Der Pol and Bremmer. The terrain irregularity model models …

Prognostics-Based Two-Operator Competition For Maintenance And Service Part Logistics, Faranak Fathi Aghdam

Masters Theses

Prognostics and timely maintenance of components are critical to the continuing operation of a system. By implementing prognostics, it is possible for the operator to maintain the system in the right place at the right time. However, the complexity in the real world makes near-zero downtime difficult to achieve partly because of a possible shortage of required service parts. This is realistic and quite important in maintenance practice. To coordinate with a prognostics-based maintenance schedule, the operator must decide when to order service parts and how to compete with other operators who also need the same parts. This research addresses …

A Novel Free Form Femoral Cutting Guide, Wesley Andrew Underwood

Masters Theses

Knee arthoplasty is a common procedure that requires the removal of damaged bone and cartilage from the distal femur so that a reconstructive implant may be installed. Traditionally, a five planar resection has been accomplished with a universal cutting box and navigated with either metal jigs or optically tracked computer navigation systems. Free form, or curved, resections have been made possible with surgical robots which control the resection pathway and serve as the navigation system. The free form femoral cutting guide serves as a non powered framework to guide a standard surgical drill along an anatomically defined pathway, resulting in …

Automating Real-Time Fault Detection For The University Of Tennessee Space Institute, Aviation Systems’ Flight Testing And Airborne Science Applications, Samuel Vivek Williams

Masters Theses

The UTSI Aviation Systems program has conducted many successful airborne science campaigns in collaboration with premier research organizations including NASA and NOAA. Each airborne science mission requires dedicated FTEs to monitor the various instruments onboard the aircraft. A typical mission requires aircraft to be instrumented with a wide range of sensors (with approximately 145 data parameters). Monitoring the instruments requires highly skilled personnel who have a thorough understanding of the system.

With the advent of UTSI Aviation Systems program increasing capabilities to conduct multiple missions, using multiple airborne platforms, the requirement of a skilled FTE for each mission could effectively …

Residential Attic Ventilation In A Hot And Humid Climate: Effects Of Increased Ventilation On Thermal Performance And Moisture Control, Stanley Arthur Atherton

Masters Theses

The reality of the effect of natural ventilation in a residential attic cavity has been the topic of many debates and scholarly reports since the 1930’s. The purpose of ventilating an attic cavity is to prevent collection of condensate on the structural surfaces, and to create a thermal buffer between the conditioned space and the ambient air. The current standards are not specific to climate zone, despite the fact that each climate zone may require ventilation for very different reasons.

To address the issue of ventilation effects in a hot and humid climate, a Natural Exposure Testing facility was constructed …

Development Of An Environmental Monitoring System For Greenhouse Disease Management, Crystal Marie Kelly

Masters Theses

A commercial African violet (Saintpaulia ionantha) grower experiences yield loss due to a leaf spot disease known as Corynespora casssiicola. Spotted leaves make the plants unmarketable. Outbreaks of the disease are costly and difficult to prevent. Greenhouse monitoring systems currently available on the commercial market do not have sufficient spatial or temporal resolution to be able to correlate the environmental conditions of the greenhouse with disease outbreaks. A new system was designed specifically to monitor for disease favorable conditions. The system developed for this project consists of several sensor stations and a coordinator station. The coordinator station …

Distributed Data Aggregation For Sparse Recovery In Wireless Sensor Networks, Shuangjiang Li

Masters Theses

We consider the approximate sparse recovery problem in Wireless Sensor Networks (WSNs) using Compressed Sensing/Compressive Sampling (CS). The goal is to recover the $n \mbox{-}$dimensional data values by querying only $m \ll n$ sensors based on some linear projection of sensor readings. To solve this problem, a two-tiered sampling model is considered and a novel distributed compressive sparse sampling (DCSS) algorithm is proposed based on sparse binary CS measurement matrix. In the two-tiered sampling model, each sensor first samples the environment independently. Then the fusion center (FC), acting as a pseudo-sensor, samples the sensor network to select a subset of …

Aeolian Simulations: A Comparison Of Numerical And Experimental Results, With Projections For Titan., Oscar Lee Mathews

Masters Theses

Aeolian processes are major determinants of geomorphology on bodies in the Solar System possessing an atmosphere-surface interface and transportable sediment, including Earth, Mars, Venus, and Titan. Substantial efforts have been made over the last few decades to understand these processes using specialized wind tunnels, field studies, and, more recently, numerical simulations. This thesis describes a model of aeolian sediment transport using computational fluid dynamics (CFD), and compares the results with those obtained in the Martian Surface Wind Tunnel (MARSWIT) testing conducted in the Planetary Aeolian Laboratory at NASA Ames Research Center. The ultimate goal of the thesis was to develop …

Thermocouple Temperature Measurements For Twin Jet Thermal Mixing, Spero Michael Peters

Masters Theses

Thermocouples are commonly used devices for temperature measurement. This study concerns the implementation of thermocouples to collect thermal mixing data in an environment in which two parallel water jets are mixing. The measurements are taken with the purpose of modeling the jet mixing region so that Computational Fluid Dynamics (CFD) models can be validated against the test data. This thesis covers the design, construction, implementation and evaluation of a thermocouple system for immersion in a water environment to measure the thermal mixing of twin jets.

The measurement system being used is a thermocouple rake whose design and fabrication is covered. …

Automated Visual Monitoring Of Machining Equipment, Timothy Wayne Ragland

Masters Theses

Metalworking equipment is designed to modify a sheet, rod, or block of metal material in order to shape it for a specific application. This equipment can operate on the metal by bending it, drilling through it, or by cutting it. For small-scale operations, many tools require a significant amount of manual input. Unless the operator has extensive training and experience, the manual input may not be precise enough for fine details that may be needed in some applications. For example, with a bending brake, obtaining an accurate angle for the bend may be quite difficult. For a particular application, an …

Potential Impacts Of Climate Change On Water Resources And Water Quality Of Norris Lake, Tennessee, Yong-Gil Choi

Masters Theses

This study assessed the potential impacts of climate change on hydrology, water resources operation, and water quality of the Norris Lake area in Tennessee. To project future climate conditions, the simulation outputs for 2030s, 2050s, and 2070s from six general circulation models (GCMs) were extracted under two Intergovernmental Panel on Climate Change (IPCC) greenhouse gases emissions scenarios (A2 and B1 for high and low emissions, respectively) to consider the range of uncertainty. The outputs of the six GCMs were weighted by considering their accuracy to simulate the climate conditions observed from 1961 to 1990 to suggest an ensemble average. A …

Transverse Waves In Simulated Liquid Rocket Engines With Arbitrary Headwall Injection, Charles Toufic Haddad

Masters Theses

This work introduces a closed-form analytical solution for the transverse vorticoacoustic wave in a circular cylinder with arbitrary headwall injection. This particular configuration mimics the conditions leading to the onset of traveling radial and tangential waves in a simple liquid rocket engine (LRE). Assuming a short cylindrical chamber with an injecting headwall, regular perturbations are used to linearize the problem’s mass, momentum, energy, ideal gas and isentropic relations. A Helmholtz decomposition is subsequently applied to the first-order disturbance equations, thus giving rise to a compressible, inviscid and acoustic set that is responsible for driving the unsteady motion and to an …

Cytongrasp: Cyton Alpha Controller Via Graspit! Simulation, Nicholas Wayne Overfield

Masters Theses

This thesis addresses an expansion of the control programs for the Cyton Alpha 7D 1G arm. The original control system made use of configurable software which exploited the arm’s seven degrees of freedom and kinematic redundancy to control the arm based on desired behaviors that were configured off-line. The inclusions of the GraspIt! grasp planning simulator and toolkit enables the Cyton Alpha to be used in more proactive on-line grasping problems, as well as, presenting many additional tools for on-line learning applications. In short, GraspIt! expands what is possible with the Cyton Alpha to include many machine learning tools and …

Introducing Water Vapor Into A High Vacuum Chamber At Aedc., James Philip Rogers

Masters Theses

A powdered form of calcium sulfate dihydrate (CaSO₄2H₂O) was heated to provide water vapor in a vacuum chamber for an experiment seeking to study cryodeposit thin films of ice at the Arnold Engineering Development Center (AEDC) in Tullahoma, TN. However, after the test was conducted, calcium sulfate deposits were found on all surfaces inside the vacuum chamber. It became clear that a new procedure for introducing the water vapor into the vacuum chamber needed to be developed. Calcium sulfate dihydrate, cobalt(II) chloride hexahydrate and 3 angstrom zeolite molecular sieves were investigated to determine how they could …

U.S Inflight Icing Accidents And Incidents, 2006 To 2010., Philip Appiah-Kubi

Masters Theses

Through its recommendations, the National Transportation Safety Board (NTSB) has helped the Federal Aviation Administration (FAA) introduce regulations that have helped to curtail icing accidents1 (an occurrence associated with the operation of an aircraft where as a result of the operation of an aircraft, any person receives fatal or serious injury or any aircraft receives substantial damage) and incidents1 (an occurrence, other than an accident, associated with the operation of an aircraft that affects or could affect the safety of operations). However, "the only acceptable safety goal of zero accident," proposed by former Secretary of Transportation, Federico Fabian Pena, has …

Particle Shielding For Human Spaceflight: Electrostatic Potential Effects On The Störmer Magnetic Dipole Exclusion Region, Benjamin Alan Klamm

Masters Theses

A basic hybrid radiation shield concept, consisting of both a monopole positive electrostatic potential barrier and a current-carrying superconducting solenoid, was predicted to provide a more effective method of shielding a habitable torus region than a solenoid acting alone. A randomized position and velocity vector simulation of equal-energy iron ions using a Lagrangian reference frame was performed on the exact magnetic field integral for the solenoid and a discrete summation electrostatic field for a toroidal monopole array approximating a potential surface. Each particle is injected at a specific energy (100, 150 MeV and 1 GeV). Two cases were evaluated at …

Power Management For Gpu-Cpu Heterogeneous Systems, Xue Li

Masters Theses

In recent years, GPU-CPU heterogeneous architectures have been increasingly adopted in high performance computing, because of their capabilities of providing high computational throughput. However, current research focuses mainly on the performance aspects of GPU-CPU architectures, while improving the energy efficiency of such systems receives much less attention. There are few existing efforts that try to lower the energy consumption of GPU-CPU architectures, but they address either GPU or CPU in an isolated manner and thus cannot achieve maximized energy savings. In this paper, we propose GreenGPU, a holistic energy management framework for GPU-CPU heterogeneous architectures. Our solution features a two-tier …

Correlating Suspended Sediment And Biological Metrics In East Tennessee Streams, Jeremy Robert Mefford

Masters Theses

Excessive suspended sediment is a major cause of pollution in US streams, as reported by the USEPA. Also known as siltation, having excessive sediment in a stream harms the biology of a stream through directly affecting living organisms, but also through harming natural habitats. Too much excessive sediment leads to a stream being declared impaired. Testing for suspended sediment levels is difficult and time consuming, so indirect methods of testing for total suspended solids (TSS) are desirable. While turbidity has been an oft used TSS surrogate in the past, this study takes the next step of looking at potential relationships …

Comparative Study On Posture And Its Influences On Horizontal Ground Reaction Forces Generated By Muscles: Implications For Crouch Gait, Hoa Xuan Hoang

Masters Theses

Crouch gait decreases walking efficiency due to the increased knee and hip flexion during the stance phase of gait. Crouch gait is generally considered to be disadvantageous for patients with cerebral palsy; however, a crouched posture may afford biomechanical advantages that lead some patients to adopt a crouch gait.

To investigate one possible advantage of crouch gait, a musculoskeletal model created in OpenSim was placed in 15 different postures from upright to severe crouch during initial, middle, and final stance of the gait cycle. A series of optimizations were performed for each posture to maximize ground reaction forces for the …

Evaluation Of An Intensive Data Collection System For Tennessee Surface Water Quality Assessment And Watershed Model Calibration, Hannah Marie Armstrong

Masters Theses

Water quality regulators, such as the Tennessee Department of Environment and Conservation, are challenged by data scarcity when identifying surface water quality impairment causes and pollutant sources. Surface water quality model users also seek to identify pollutant sources and design and place best management practices to efficiently improve water quality, but have insufficient data for model calibration. This research documents the design and evaluation of a novel, intensive water quality data collection system consisting of a automatic sampler, bi-weekly grab sampling, and a long term deployment sonde. System design characteristics that were emphasized included a focus on gathering data for …

A Feasibility Study For Using Commercial Off The Shelf (Cots) Hardware For Meeting Nasa’S Need For A Commercial Orbital Transportation Services (Cots) To The International Space Station - [Cots]2, Chad Lee Davis

Masters Theses

The space vehicle system concept (i.e. resupply vehicle) described is based on the new direction that President George W. Bush announced on January 14, 2004 for NASA’s Human Exploration, which has the space shuttle retiring in 2011 following the completion of the International Space Station (ISS). This leads to a problem for the ISS community regarding the capability of meeting a sixty metric-ton cargo shortfall in resupply and the ability of returning large payloads, experiment racks and any other items too large to fit into a crew only type spacecraft like the Orion or Soyuz. NASA and the ISS partners …

A Theoretical And Experimental Comparison Of Aluminum As An Energetic Additive In Solid Rocket Motors With Thrust Stand Design, Derek Damon Farrow

Masters Theses

The use of aluminum as an energetic additive in solid rocket propellants has been around since the 1950’s. Since then, much research has been done both on the aluminum material itself and on chemical techniques to properly prepare aluminum particles for injection into a solid propellant. Although initial interests in additives were centered on space limited applications, performance increases opened the door for higher performance systems without the need to remake current systems. This thesis aims to compare the performance for aluminized solid rocket motors and non-aluminized motors, as well as focuses on design considerations for a thrust stand that …

Bankfull Geomorphic Relationships And Reference Reach Assessment Of The Ridge And Valley Physiographic Province Of East Tennessee, James Brady Mcpherson

Masters Theses

Waterways have been geomorphically altered or disturbed by development, mining, agriculture and other human activities for many years. Section 404 of the Clean Water Act determined that these impacts to our waterways must be mitigated for channel alterations. Stream restoration has been one method to mitigate for these impacts to our water resources. Stream restoration is considered to be a measurable improvement to the channel stability, water quality, habitat or overall function of a degraded stream system. Practices of stream restoration have changed in the last 10 to 20 years with the introduction of natural channel design methods. Natural channel …

Dynamic Human Resource Predictive Model For Complex Organizations, Tachapon Saengsureepornchai

Masters Theses

Every organization has to deal with planning of the appropriate level of human resources over time. The workforce is not always aligned with the requirements of the organization and it increases an organization’s budget. A literature review reveals that there is no model that can systematically predict accurate human resource required within a complex organization. To address this gap, a human resource predictive model was developed based on material requirements planning (MRP). This approach accounts for complexity in workforce planning and generalized it with a logistic regression model. The model estimates the employee turnover number and forecasts the expected remaining …

The Effects Of Varying Physical Parameterizations And Initial Conditions On Tracer Transport In The National Aeronautics And Space Administration’S Goddard Earth Observation System Model, Version 5, Melissa Ree Allen

Masters Theses

The evolution of General Circulation Models (GCM) for climate study has led to more accurate predictions for atmospheric transport, yet precision in predictions remains in need of improvement. The National Aeronautics and Space Administration Goddard Earth Observation System model, Version 5 (GEOS-5) represents a state of the art climate model capable of simulating a wide variety of atmospheric processes informed continuously by satellite observations. This thesis examines some of the physical parameterizations employed by GEOS-5 and their effect on the transport of two greenhouse gasses: ozone and carbon dioxide.

Primary User Emulation Attacks In Cognitive Radio - An Experimental Demonstration And Analysis, Benjamin James Ealey

Masters Theses

Cognitive radio networks rely on the ability to avoid primary users, owners of the frequency, and prevent collisions for effective communication to take place. Additional malicious secondary users, jammers, may use a primary user emulation attacks to take advantage of the secondary user's ability to avoid primary users and cause excessive and unexpected disruptions to communications. Two jamming/anti-jamming methods are investigated on Ettus Labs USRP 2 radios. First, pseudo-random channel hopping schemes are implemented for jammers to seek-and-disrupt secondary users while secondary users apply similar schemes to avoid all primary user signatures. In the second method the jammer uses adversarial …

Applications Of Nanoparticle Image Velocimetry In Nanofluids, Sara Salim Haque

Masters Theses

Particle Image Velocimetry (PIV) is an optical technique used for the visualization of fluid flow. PIV can be combined with other techniques to enhance the analysis of fluid flow. A novel far-field plasmonic resonance enhanced nanoparticle-seeded Particle Image Velocimetry (nPIV) has been demonstrated to measure the velocity in a micro channel. Chemically synthesized silver nanoparticles have been used to seed the flow. By using Discrete Dipole Approximation (DDA), plasmonic resonance enhanced light scattering has been calculated for spherical silver nanoparticles with diameters ranging from 15 nm to 200 nm in two media: water and air. The diffraction-limited plasmonic resonance enhanced …

Comparison Of Two Methods For The Assessment Of Chloride Ion Penetration In Concrete: A Field Study, Eric William Ryan

Masters Theses

The currently accepted method for assessing the resistance of concrete to penetration of chloride ions is ASTM C1202, commonly known as the “Rapid Chloride Permeability (RCP) Test.” The test is time-consuming, laborious, has rather high variability, and, is to a degree, user sensitive, making it problematic for inclusion in a performance-based specification. A potential alternative to the RCP test is the “Surface Resistivity (SR) Test”, a method which is dramatically easier, faster, and has less variability than the RCP test. The research reported herein was directed toward determining a correlation between RCP and SR test measurements for Tennessee bridge deck …

Particle Trajectories In Wall-Normal And Tangential Rocket Chambers, Ajay Katta

Masters Theses

The focus of this study is the prediction of trajectories of solid particles injected into either a cylindrically- shaped solid rocket motor (SRM) or a bidirectional vortex chamber (BV). The Lagrangian particle trajectory is assumed to be governed by drag, virtual mass, Magnus, Saffman lift, and gravity forces in a Stokes flow regime. For the conditions in a solid rocket motor, it is determined that either the drag or gravity forces will dominate depending on whether the sidewall injection velocity is high (drag) or low (gravity). Using a one-way coupling paradigm in a solid rocket motor, the effects of particle …