Engineering Commons^™

Cavitation Of Mercury In A Centrifugal Pump, David Alan Hooper

Masters Theses

Cavitation is a significant concern for the reliable operation of a centrifugal pump. Liquid metal flow loops are used in nuclear, chemical, metal forming, and liquid metal dynamo applications. Understanding of the cavitation characteristics of liquid metals is increasingly important to the design and operation of these facilities. One recent field of cavitation research has developed for mercury flow in spallation targets used in neutron sources. To further the understanding of mercury cavitation, a review of the existing literature on water cavitation, liquid metal cavitation, and mercury cavitation is performed. The mechanics of cavitation and the analytical methods applied to …

Modbus Implementation Using A Serial Link, Naresh Karnam

Masters Theses

Serial Communication is a process of sending one bit at a time, sequentially over a communication channel or a computer bus. RS-232 and RS- 484 are two such examples of the architecture of Serial Communication. This work primarily aims at establishing a communication channel between three entities namely the Controller also called the Console, the Relay Unit and a PC. This work aims at designing the communication model, using the Client-Server architecture and using the MODBUS protocol, as the standard for transmitting the bits in a Remote Terminal Unit (RTU) mode and for framing the characters. The MODBUS protocol also …

Using Multivariate Analysis Of Geochemical Data To Better Define Hydrologic Interfaces In Surface Water - Groundwater Systems, Candice Ann Owen

Masters Theses

Groundwater-surface water interactions have been shown to be important to flow generation and stream chemistry in upland catchment environments. These areas, however, are often difficult to access making the implementation of standard hydrological surface and subsurface monitoring equipment and characterization procedures impractical, arduous and in many cases impossible due to the nature of the terrain and also regulatory guidelines for protected areas. By collecting surface water samples at distinct water contribution sites to a headwater stream, areas of groundwater influence were inferred and a hydrochemical conceptual model of a small basin was created.

The objectives of this research were to …

Vascular Hemodynamics Cfd Modeling, Shashank Kiran Karra

Masters Theses

Three dimensional pulsatile blood flow CFD simulations in geometrically genuine normal and non-normal (aneurysm) human neck-head vascular systems nominally spanning the aortic arch to the circle of Willis has been performed and studied. CT scans of the human aortic arch and the carotid arteries were interpreted to obtain geometric data defining the boundary for a vascular CFD simulation. This was accomplished by reconstructing the surface from the anatomical slices and by imposing pertinent boundary conditions at the various artery termini. Following automated formation of a non-conformal CFD mesh, steady and unsteady laminar and low turbulent simulations were performed both for …

A 64-Channel Mixed-Signal Data Acquisition System For A Solid-State High Efficiency Neutron Detector Array, Anthony Gene Antonacci

Masters Theses

This thesis presents the design of multiple analog and digital blocks required to implement a desired solid-state data acquisition system for the High Efficiency Neutron Detector Array (HENDA) project under the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). This system encloses and is an extension of prior work described in [1] and [2]. The first prototype chip, named Patara, contained a charge sensitive front-end amplifier [2], and a semi-Gaussian shaper with baseline restore circuitry [1]. Patara III, described in this thesis, involved the addition of the following system components; two comparators, a selectable synchronous/asynchronous digital …

Correlating Grain Boundary Microstructure And Ductility Loss On Aging In Haynes® 25, Darryl Britt Glanton

Masters Theses

Haynes® 25 is a cobalt-base superalloy known for its excellent high temperature strength and corrosion resistance. However, this alloy undergoes severe embrittlement on aging at elevated temperatures. Historical research associated this ductility loss with the formation of a Co₂W Laves phase, but more recent studies have challenged the existence of this phase after prolonged aging at temperatures above 600°C. In this study, scanning and transmission electron microscopy were used to characterize the chemistry and location of precipitates in the alloy after aging at temperatures of 675 and 850°C for times up to 12,000 hours. These data were compared …

Blast Resistant Design Of Steel Structures, Sarah Beth Janney

Masters Theses

The purpose of this study was to examine the load experienced by a steel blast cubicle from a surface blast test. An important objective was to determine the blast load experienced at different standoff distances and the blast resistance capability of the blast cubicle. Three cubicles with standoff distances of 20, 25, and 30ft respectively were simultaneously subjected to a 50lb TNT explosive. The manual Structures to Resist the Effects of Accidental Explosions, Army TM 5-1300 conservatively predicted the blast pressure loadings obtained from the pressure transducers mounted on the cubicles. Data collected from accelerometers was compared to results from …

Evaluation Of Head Linear And Rotational Acceleration Response To Various Linear-Induced Impact Scenarios, Robert Paul Roy

Masters Theses

Incidents resulting in head injury generally involve components of both linear and rotational motion. The protection of the head from injury most often comes from the use of some form of helmet. Helmets currently are designed only to protect the head from linear accelerations. Recent research involving the analysis of concussion in professional football suggested that linear accelerations are more consistent in the prediction of concussion, with the resultant rotational accelerations correlating to the peak linear accelerations of the impact.

This research proposes to determine if the situation of the head impact has an effect on the correlation of the …

Virtual Modeling And Verification Of Air-Ride Truck Seat Using Multibody Dynamics For Whole Body Vibration Evaluation, Devdutt Nandkishore Shende

Masters Theses

To aid the tuning and optimization of the truck seat design to specific trucks and road profiles during the design phase, this study presents the development and validation of a virtual seat model. This study also assess the utility of the model for whole body vibrations evaluation.

The virtual dynamic seat model was developed in MSC. ADAMS/VIEW. The critical elements like the suspension mechanism, the airspring, dampers and seat cushion were modeled using tested data. To validate the performance of the virtual model, prototype tests were performed using the MTS 6-axis simulator. The modeling process was targeted to achieve a …

Security Printing: Towards Hologram Printing, Sachin Ravindra Agate

Masters Theses

Today we are facing many situations where the genuineness of the products and documents is questioned. Counterfeiting the original products has become a business of few people, which result in the degradation of quality of products, loss of money and loss of faith of end user. To prevent such malicious act, security features are added in the final product. Security printing is one of those methods that help in preventing counterfeit products and treachery. There are many different security features, which can be added in the security printing. Apart from those features, an embossed hologram is also included in prints …

Factors That Affect The Perception Of Company Success By Assembly Workers In The Boat Industry, Karima Tayeb

Masters Theses

Employee retention is critical to an organization’s competitive position. Employees are resources; and a “good” employee is a valuable asset. From a system’s perspective, employees are critical elements that are needed to ensure the output can be produced effectively and efficiently. Thus, management of this resource is critical for a company’s success. Maintaining a stable workforce in the boat manufacturing industry is a challenge. This is especially true in the assembly area where the average job is unskilled and not considered a career position. The purpose of this study is to identify the individual and organizational factors that contribute to …

Analysis, Modeling And Testing Of A Multi-Receiver Wireless System For Telemetry Applications, Thomas Ebel

Masters Theses

This thesis investigates the potential value of multiple co-located receiver units for telemetry applications. In this thesis, a test board based on the NRF24L01 RF chip produced by Nordic Semiconductor was tested. Testing consisted of sending pseudo-random test data over a link between two test boards at progressive distances. Packet loss rate was identified as the dominant failure mode of the chip, and was used to determine performance increase. A parametric model of the chip performance was developed based on coherent and noncoherent FSK detectors and curve fit to the experimental data to model the performance of a single GFSK …

The Impact Of Organizational Attributes On Project Performance As Measured By On-Time Delivery And Budget, Zeid El-Akkad

Masters Theses

Before we determine what lean tools are suitable for an office environment and how to modify those tools to make them more suitable and in order to develop a lean office, it is important to understand the different processes and aspects within an office. For this reason, better understanding of office processes and aspects helps facilitate the deployment and implementation and modification of different lean techniques to better suit the office environment. The purpose of this paper is to identify seven different factors to compare against one another and against project performance in terms of on-time delivery and budget. The …

Predictive Models Of An Electro-Mechanical Driving System For Failure Testing Of Strain Gauges, Brent Ellis

Masters Theses

Strain gauges are bonded at high stress locations on the surface of critical structural components such as turbine blades to measure fatigue characteristics and detect early warning signs of high cycle fatigue. However, strain gauges do not always report expected measurements. The usual response by maintenance technicians to these failing signals is to investigate the component for weakness, check the placement of the gauges on the component, or examine the instrumentation for failure or damage. However, little research has been conducted to show when the failing signals are the fault of the strain gauge. Such failure modes of strain gauges …

Model Reduction Techniques For Fluid Dynamical Flow Based Pde Control Problems, Jason Harold Foster

Masters Theses

This thesis deals with the practical and theoretical implications of model reduction for aerodynamical flow based control problems. Various aspects of model reduction are discussed that apply to Partial Differential Equation (PDE) based models in general. Specifically, the Proper Orthogonal Decomposition (POD) of a high dimension system is discussed as well as frequency domain identification methods are discussed for initial model creation. Projections on the POD basis give a Galerkin model. Then, the methods of balanced truncation and Hankel optimal norm reduction are applied to the Galerkin model. A state space model is formed by a Galerkin projection of the …

Study Of Interaction Between Mexican Free-Tailed Bats (Tadarida Brasiliensis) And Moths And Counting Moths In A Real Time Video, Haritha Kolli

Masters Theses

Brazilian free tailed bats (Tadarida brasiliensis) are among the most abundant and widely distributed species in the southwestern United States in the summer. Because of their high metabolic needs and diverse diets, bats can impact the communities in which they live in a variety of important ways. The role of bats in pollination, seed dispersal and insect control has been proven to be extremely significant. Due to human ignorance, habitat destruction, fear and low reproductive rates of bats, there is a decline in bat populations. T.brasiliensis eats large quantities of insects but is not always successful in prey …

Hardware Accelerated Scalable Parallel Random Number Generation, Junkyu Lee

Masters Theses

The Scalable Parallel Random Number Generators library (SPRNG) is widely used due to its speed, quality, and scalability. Monte Carlo (MC) simulations often employ SPRNG to generate large quantities of random numbers. Thanks to fast Field-Programmable Gate Array (FPGA) technology development, this thesis presents Hardware Accelerated SPRNG (HASPRNG) for the Virtex-II Pro XC2VP30 FPGAs. HASPRNG includes the full set of SPRNG generators and provides programming interfaces which hide detailed internal behavior from users. HASPRNG produces identical results with SPRNG, and it is verified with over 1 million consecutive random numbers for each type of generator. The programming interface allows a …

Physiological Stress In Native Brook Trout (Salvelinus Fontinalis) During Episodic Acidification Of Streams In The Great Smoky Mountains National Park, Keil Jason Neff

Masters Theses

Episodes of stream acidification are suspected to be the primary cause of the extirpation of native southern brook trout (Salvelinus fontinalis) from six headwater streams in the Great Smoky Mountains National Park (GRSM). During periods of increased flow from storm events, stream pH can drop below 5.0 (minimum of 4.0) for 2-days or longer. To provide evidence that native brook trout are impacted by stream acidification, in situ bioassay experiments were conducted. Changes in stream water chemistry and brook trout physiology were determined during a 36-hour acidic episode at three remote headwater stream sites in the Middle Prong of the …

A Full Scale Camera Calibration Technique With Automatic Model Selection – Extension And Validation, Vitaliy Leonidovich Orekhov

Masters Theses

This thesis presents work on the testing and development of a complete camera calibration approach which can be applied to a wide range of cameras equipped with normal, wide-angle, fish-eye, or telephoto lenses. The full scale calibration approach estimates all of the intrinsic and extrinsic parameters. The calibration procedure is simple and does not require prior knowledge of any parameters. The method uses a simple planar calibration pattern. Closed-form estimates for the intrinsic and extrinsic parameters are computed followed by nonlinear optimization. Polynomial functions are used to describe the lens projection instead of the commonly used radial model. Statistical information …

Applying Human Factors Principles In Aviation Displays: A Transition From Analog To Digital Cockpit Displays In The Cp140 Aurora Aircraft, Ryan C. Palmer

Masters Theses

A flight test program that evaluated the results of a CP140 Aurora cockpit modernization project was conducted between May 2004 and October 2005. This paper uses the results of that test program to show how basic human factors principles were violated which led to the identification of multiple design deficiencies. This paper proposes that the failure to apply good human factors principles when designing aircraft displays can lead to unacceptable deficiencies. The result can be poor modal awareness, confusion in the cockpit, and often negative training for the pilots. In particular, four major deficiencies were analyzed to determine the specific …

Influence Of The Sampling Procedure On Extracted Jet Engine Exhaust Gas Emission Samples, Ashley Dawn Owens

Masters Theses

The purpose of this thesis is to analyze the effects of an intrusive sample extraction process on the thermo-chemistry of extracted gas samples taken from exhaust of a GE-J85-H turbojet engine. The engine testing took place at University of Tennessee Space Institute in Tullahoma, TN, where the J85 was installed in a test bay of a research facility. The results of the analysis validate that testing methods used had a low probability of disturbing the exhaust chemistry. The tools used to analyze the thermal history of the extracted samples were the NASA CEA and LSENS programs. Several different cases of …

Active Vibration Control Using Optimized Piezoelectric Topologies, Matthew James Parsons

Masters Theses

This work investigates the optimal topology of an actively controlled piezoelectric actuator bonded to an elastic cantilever beam under steady-state harmonic loading near the first natural frequency of the beam. The actuator is discretized using finite elements, and control is applied to the actuator based on the sensor’s degrees of freedom using proportional control. This study investigates the optimal distribution of actuator material for one and five layers of finite elements. The optimized actuator topology shows substantial improvement over initial piezoelectric topologies and over traditional actuator placement. This study has two main topics, material homogenization and topology optimization. The piezoelectric …

Effect Of Length On The Performance Of Lean NoX Traps, Vitaly Y. Prikhodko

Masters Theses

The effect of monolith length on the NO_x performance of two different Lean NO_x Traps has been investigated using a bench flow reactor (BFR). The washcoat composition of one of the catalysts consists of Pt/K/γ-Al₂O₃; the major components of the other catalyst include Pt, Pd, Rh, barium, ceria and zirconia supported on γ-alumina washcoat. Samples of 2.22-cm in diameter and length of 2.54, 5.08 and 7.62-cm within each LNT were evaluated with long and short-cycle experiments at a fixed gas hourly space velocity, and results were compared between samples of different lengths. No significant …

The Reliability Of Signal Strength For Localization Of High-Density Zigbee Wireless Networks, Brandon Jeremy Rogers

Masters Theses

This thesis investigates the reliability of ZigBee signal strength within a high-density wireless network, specifically looking at the Link Quality Indicator (LQI) as provided by the physical layer and accessible at the networking and application layers within the stack protocol. It also investigates methods by which LQI can be used for discovery, identification, and localization of nodes within a ZigBee wireless network. The thesis concentrates on practical approaches specifically as it would pertain to commissioning a high-density network for an application such as lighting control in building automation. There are seven potential algorithms proposed using factors such as minimum distance …

The Synthesis And Characterization Of A Novel Polysaccharide Hydrogel For Biomedical Applications Including The Treatment Of Malignant Tumors And The Prevention Of Metastatic Disease, Elizabeth Diana Barker

Masters Theses

Amygel® is an injectable biodegradable controlled release drug delivery system with adjustable release kinetics determined by varying the concentrations of the polymeric components of the material. Amygel® is a starch based biodegradable hydrogel consisting of an interpenetrating network of physically entangled amylose and amylopectin polymer chains crosslinked with d-glucaric acid. Amylose and amylopectin are the two components of naturally occurring starch. The immiscibility of the amylose and amylopectin due to differences in solubility parameter and chain size induces phase separation within the network but because the chains entangled during hydrolysis an interpenetrating network is formed. The chemically reactive carboxyl groups …

Health Monitoring Of Concrete Bridges Utilizing Sensor Technology, Ammar Zalt

Masters Theses

Structural health monitoring using sensor technology is a promising way to provide excellent means for protecting important structures such as bridges, dams, and nuclear reactors. These sensors provide real-time information about structural conditions, They work together as a nervous system to provide timely information for emergency and risk mitigation. The information obtained from these sensors can later be analyzed and compared to the design data so that the problem can be detected and fixed before it develops into a serious and costly hazard.

Throughout the course of this thesis the feasibility and performance of two types of sensors will be …

Evaluation, Comparison, And Design Of Two Experimental Bridges In Tennessee, Kyle Parker Scoble

Masters Theses

This thesis describes the design and evaluates the adequacy of the moment connection of an experimental two-span highway bridge designed by the Tennessee Department of Transportation. The Massman Drive bridge is an experimental design that unifies the construction economy of simple span bridges and the structural economy of continuous span bridges. The experimental connection, consisting of cover plates and kicker wedge plates, is used to connect the two adjoining girders over the center pier. As a result, the bridge is designed to function as a continuous bridge during the deck pour and behave compositely with the reinforced concrete deck under …

Intrustive Probe Measurements In A High-Temperature Mach Two Flow, Sonya Renee Nelson

Masters Theses

To acquire heat transfer measurements of a high temperature Mach two flow a water-cooled calorimeter was placed in the flow and the water temperature rise was used to calculate the heat transfer rate and the recovery temperature of the gas. In addition, a graphite rod with a stainless steel tube at its core was used to measure the total pressure of the flow. This pressure probe was swept through the flow for two test runs to acquire a stagnation pressure profile of the gas flow. All results were compared to NASA CEA computer simulation code results. The heat transfer and …

Fabrication Of Nano-Injection Needles For Neural Pathway Study In Mice, Sangeetha Swaminathan

Masters Theses

The potential of micro-needles to provide an interconnection between the microscopic and the macroscopic worlds makes it one of the most revolutionary fields in health care, allowing for precise transdermal drug delivery of highly targeted small doses of the active compound. Current micro electro mechanical systems (MEMS) technologies, originally designed for the micro-electronics industry, have been utilized in the fabrication of different micro-needle designs and their integration with various micro-fabricated micro-fluidics devices. The target of this thesis is to achieve a micro-needle injection system to deliver several strains of pico-liter volumes of a fluid combination of transgenic virus and luminescent …

“Parametric Study Of The Effects Of Water To Cementitious Materials Ratio And Cementitious Materials Content On The Durability Properties Of High Performance Concrete, Andrew T. Tinsley

Masters Theses

This study takes a detailed look at the factors that affect the durability of concrete and how they can be applied to the development of a useful performance specification and help to extend the life of bridge decks and other concrete structures exposed to the elements of nature. A series of fifteen mixes (with varying cement contents and water/cement ratios) were performed in order to determine exactly which of these factors have a significant effect on the durability of a concrete mix. Controlling the water/cement ratio is necessary in order to control strength and permeability. Cement content was found to …