Engineering Commons^™

Traceable Standard For Sub - 100nm Metrology, Sachin Jayant Deo

Masters Theses

As we approach the 65nm technological node, transistor gates with dimensions of the order of 40nm are being manufactured. As the device performance is directly related to the dimensions of the gate, critical dimension (CD) control becomes an important part of the fabrication process. Characterization of these small feature size, generally referred to as Metrology, is an indispensable ingredient of the semiconductor manufacturing processes. Metrology relies not only on the precision, but also the accuracy of commercially used metrology tools like the CD-SEM. To facilitate the magnification calibration of the CD-SEM, an easy access to standard reference artifact traceable …

Energy Harvesting Using Optimized Piezoelectric Microcantilevers, Ahmed Mohamed Elalfy

Masters Theses

In this thesis, the energy producing capabilities and efficiency of Piezoelectric materials for ambient energy harvesting from multi-layered micro-cantilevers are analyzed. The cantilevers are then optimized utilizing a homogenization approach involving the redistribution of materials in all regions throughout the three dimensional model to yield the greatest voltage output for a specified tip force under static loading; This would be analogous to having the greatest energy production. The design of the model using the Finite Element Analysis (FEA) software ABAQUS is used in conjunction with a commercial FORTRAN optimization code, where the FEA software handles the mechanical design aspect of …

An Evaluation Of The Design Requirements Of The H-1 Upgrades Helicopter Blade Fold Racks, Matthew D. Funk

Masters Theses

The United States Marine Corps contracted Bell Helicopter Textron Inc. (BHTI) to develop and field new versions of the aging UH-1N and AH-1W helicopters. As part of the development effort of the H-1 Upgrades, BHTI was tasked with development of a folding rotor system and the associated equipment necessary to support main rotor folding operations. The blade fold equipment (BFE) was constrained throughout the development process by a list of conflicting requirements. The requirements for commonality, versatility, simplicity, light weight, rapid application, and durability, while each was generally reasonable, could not be satisfied with one set of equipment. The resulting …

Implementation Of The Acoustic Rapid Commercial-Off-The-Shelf Insertion Development Model In The P-3c Acoustic System, John Bruce Gailey Jr.

Masters Theses

The P-3C is a U.S. Navy aircraft designed for the Maritime Patrol and Reconnaissance mission. Although capable in a number of mission areas, the aircraft’s Anti-Submarine Warfare capabilities have received much attention lately due to improvements in diesel submarine technology. The acoustic systems on the P-3C needed a better way to more rapidly incorporate new technology while working within a constrained budget environment.

The purpose of this study is to show how the P-3C Acoustic System can be transformed by shifting from the slow, expensive traditional Military Specification (MILSPEC) development process to the successful Acoustic Rapid Commercial-Off-The-Shelf (COTS) Insertion (ARCI) …

A Crosslayer Routing Protocol (Xlrp) For Wireless Sensor Networks, Raghul Gunasekaran

Masters Theses

The advent of wireless sensor networks with emphasis on the information being routed, rather than routing information has redefined networking from that of conventional wireless networked systems. Demanding that need for contnt based routing techniques and development of low cost network modules, built to operate in large numbers in a networked fashion with limited resources and capabilities. The unique characteristics of wireless sensor networks have the applicability and effectiveness of conventional algorithms defined for wireless ad-hoc networks, leading to the design and development of protocols specific to wireless sensor network. Many network layer protocols have been proposed for wireless sensor …

Commerical Vehicle Enforcement Using License Plate Recognition Technology, Stephanie R. Hargrove

Masters Theses

Speed limits for large trucks have been reduced at many locales for air quality and safety reasons. To realize an improvement in air quality and safety, however, diligent enforcement and fitting punishment have to be implemented. This may put a strain on already tight resources and manpower for state and local agencies. To this end, this paper presents a license plate recognition (LPR) technology based heavy vehicle speed enforcement system that requires relatively minimal initial investment and no increase in enforcement personnel, cruisers, or pursue/pull-over activities. The efficiency of the system is achieved by catching speeding trucks in the act …

Pilot Vehicle Interface Improvements To The F/A-18 Weapon System (Using Human Factors Solutions To Increase Efficiency), Thomas B. Heck

Masters Theses

The purpose of this study was to evaluate and provide recommendations for optimizing the Pilot Vehicle Interface for components of data link systems employed on and currently in design for the F/A-18 Hornet and Super Hornet. Data was gathered using human factors research methodologies including descriptive studies, experimental research, and evaluation research. Additionally, flight and lab tests were used to gather data on systems that were mature enough in development. Overall, the study revealed that the interfaces for the systems evaluated could be modified in order to provide more situational awareness to the operator, allow for more logical display of …

Utilizing An Ultrasonic Device To Model The Lumbar Spine While Driving A Tractor Trailer, Gretchen Marie Hinton

Masters Theses

Low back pain is a common occupational effect of the long term driving of vehicles. The sonoSens® Monitor ultrasonic device was utilized to model lumbar spinal motions while driving a tractor trailer. Further data was collected to determine if acceleration from a seat pad and EMG data correlated with the driver’s movements.

Three testing bouts were completed and analyzed for this study. For each test the driver drove a 1998 Peterbuilt 379 fitted with a National Seating 2000 seat. One driver was used for all three tests.

Data analysis was accomplished with the sonoSens® Analyzer and Microsoft® Excel software. The …

A Simulation Model For Predicting Surface Tension In Condensate Films, Allison Dawn Lewis

Masters Theses

The thesis presents a mathematical model for predicting surface tension in condensate films. The approach taken to this study is different from how surface tension is normally approached. Surface tension is primarily determined through laboratory measurements. This work shows how it can be determined mathematically based on the formulation of bonding energy between atoms as described by the Lennard-Jones potential.

The results are used to predict the surface tension of a selected group of elements and molecules. Predictions from the model compare favorably with the documented surface tension values of the selected elements. However, the model does deviate somewhat from …

Experimental Aerodynamic Analysis Of Converging Free Jets, Nathanael Tate Mcbee

Masters Theses

The setup of the converging jets is commonly used in the manufacture of meltblown fibers. This requires forced airflow through small channels angled toward each other until meeting at the exit of the die. The emerging air jets impinge while molten polymer is extruded and becomes entrained in the air flow to be collected downstream as a thin cooled fiber.

The experimental analysis of converging free jets was examined to reveal characteristics of the flow field. A hot-film anemometer was used to gather and analyze the corresponding data for two separate meltblown fiber dies. These were examined and compared to …

A Compliance Strategy For Use Of Gps For Ifr Navigation In The E-2c Hawkeye, James Robert Mires

Masters Theses

Naval aviation is on the brink of taking advantage of a 12 year old capability. Naval commercial derivative aircraft have had the ability to navigate in instrument meteorological conditions using global positioning technology for nearly as long as civil commercial-for-hire aircraft. However, tactical naval aircraft, like the E-2C Hawkeye, are now only beginning to obtain and install the necessary technology to meet federal aviation regulations for satellite based area navigation.

Worldwide airspace controlling agencies have mandated the use of navigation equipment that meets highly specific performance standards prior to entry in required navigation performance airspace. Aircraft not compliant with these …

Lard Used As A Fuel For Hybrid Rocket Motors, Daniel Lee Pfeffer

Masters Theses

A bio-derived fuel, lard, was successfully tested using a laboratory scale hybrid rocket motor and a static test stand at the University of Tennessee-Knoxville. The experimental setup used gaseous oxygen as the oxidizer. Twenty-three experimental tests were successfully conducted with lard and oxygen. The nine-inch fuel grains used in the current investigation produced a measured thrust ranging from 70-145 Newtons (15-33 pounds) with calculated specific impulses ranging from 122-181 seconds. All the tests conducted were intensely fuel rich, and had equivalence ratios ranging from 0.2 to 0.45. The low equivalence ratios are partially due to unburned fuel particles that exit …

Mathematical Modeling Of Reverse Flow Oxidation Catalysts, Barath Raghavan

Masters Theses

A theoretical model and a computer simulation on methane (CH4) reduction in a simulated natural gas exhaust mixture are performed for a Reverse-Flow Oxidation Catalyst. This theoretical model is to predict the conversion of methane flowing through an oxidation catalyst with periodic reversal of flow direction. The model developed for this purpose is a transient, 1-Dimensional plug flow model with gas phase reactions and surface reactions. The derivation of the model resulted in the mole balance equation and the energy balance equation for the gas phase and the solid phase. The momentum equation for this model is neglected as it …

The Design And Integration Of An Airborne Imager And Flight Campaign To Study The Time Evolution And Vertical Structures Of Polar Mesospheric Clouds, Jason David Reimuller

Masters Theses

The scientific objective of this study is to design an aircraft flight experiment that will provide airborne imaging data, augmenting satellite data, to advance the fundamental understanding of polar mesospheric clouds (PMCs). By capturing simultaneous top and bottom views of the PMCs, these airborne images will both provide insight into the time evolution of PMCs, and into the micro-features of these clouds, from which gravity waves and other details of the clouds vertical structures may be obtained. These data may help us better understand the driving mechanisms of these clouds and ultimately those elements of global climatic change, which are …

F/A-18a-D Hornet Current And Future Utilization Of Mode I Automatic Carrier Landings, Brian T. Schrum

Masters Theses

The purpose for writing this thesis is to prove the automatic carrier landing system (ACLS) a valuable Operational Risk Management (ORM) tool for recovering F/A-18A-D aircraft aboard the modern aircraft carrier. ORM is itself a subset of human factors and worthy of exploration in the aviation systems field. In proving the value of the ACLS, the author presents the following objectives: 1) describe the major components of the F/A-18A-D and modern aircraft carrier ACLS, 2) describe the current Mode I approach procedures, and the Precision Approach Landing Systems (PALS) certification process, 3) promote an increase in automatic landings during night …

Energy Harvesting From Vibration Of A Bridge, Sri Harish Valluru

Masters Theses

Basic research in smart materials and structural systems has demonstrated great potential for enhancing the functionality, serviceability and durability of civil and mechanical infrastructure systems. These smart materials (like piezoelectric materials) can be used as mechanisms to transfer mechanical energy, usually ambient vibration, into electrical energy that can be stored and used to power other devices. The intelligent renewal of aging and deteriorating civil and mechanical infrastructure systems includes efficient and innovative use of high performance sensors, actuators, and structural systems. In this work, a computational model is developed to generate power from the ambient vibration of a single span …

Experimental Investigation Of Reinforced Concrete Beams With Lapped Reinforcement, Mary Elizabeth Griffey

Masters Theses

One of the great contributions made by President Dwight D. Eisenhower was his influence in the implementation of the National Interstate and Defense Highways Act of 1956. The National Highway System serves an important role in American citizen's ground transportation. Now more than a half of a century in age, there is a high priority to repair existing infrastructure as well as the need for expansion. Repair and expansion must be achieved efficiently by reducing construction time and improving the capacity and durability of the structure. Precast, prestressed decked bulb tees (DBTs) serve as an excellent solution to ensure quality …

Nonlinear Behavior Of Longitudinal Waves In The Oscillations Of Rijke Tube, Nagini Devarakonda

Masters Theses

The Rijke tube device has been employed since its invention in 1859 in the experimental study of many examples of thermo-acoustic phenomena. The device exhibits generation of acoustic oscillations by heat energy supplied to the flow field in the fashion of a selfexcited oscillator. In recent times, the Rijke tube has proved to be a valuable tool in simulation of combustion instability phenomena in rockets and industrial burners. Despite the simplicity of the device, the Rijke tube simulates most important geometrical and physical features that lead to the growth of nonlinear pressure oscillations in combustion chambers. For example it provides …

Theoretical Techniques For Determining Precise Thermophysical Properties, Mohamad Hadi Kassaee

Masters Theses

Quantum mechanics (QM) calculations, coupled with statistical mechanics (SM), provide a means to obtain thermophysical properties from first principles. Because of the limitations in modern computational resources, many of these properties are obtained for isolated molecules. Despite this limitation, QM is still very useful for thermophysical property generation in an ideal gas reference state where the molecules are isolated.

In this thesis, a combination of quantum mechanics and statistical mechanics calculations is used to generate entropies of aromatic compounds in the ideal gas reference state. This information is necessary for practical calculations such as the determination of the free energy …

Design And Analysis Of A General Purpose Operational Amplifier For Extreme Temperature Operation, Chandradevi Ulaganathan

Masters Theses

Operational amplifiers (op amps) are key functional blocks that are used in a variety of analog subsystems such as switched-capacitor filters, analog-to-digital converters, digital-to-analog converters, voltage references and regulators, etc. There has been a growing interest in using such circuits for "extreme environment" electronics, in particular for electronics capable of operating down to deep-cryogenic temperatures for lunar and Martian surface explorations.

This thesis presents the design and analysis of a general purpose op amp suited for “extreme environment” applications, with a wide operating temperature range of 93 K to 398 K. The op amp has been implemented using a CMOS …

A Novel Power Supply For Generating A One Atmosphere Uniform Glow Discharge Plasma (Oaugdp®), Laurent Jose Calvez

Masters Theses

A high voltage transformer connected to an atmospheric plasma generator is driven as a current-fed push-pull parallel resonant system, switched by a resonant lamp controller integrated circuit from Texas Instruments (UC3872) in such a manner as to be automatically maintained at resonance. The frequency range of interest is the audio range, which creates a particularly uniform glow discharge in atmospheric pressure air. Frequency control is achieved by a specially constructed high voltage variable capacitor connected parallel to the secondary, in conjunction with a variable parallel primary inductance. Voltage control is achieved by variation of the input DC current amplitude.

How Airbus Surpassed Boeing: A Tale Of Two Competitors, William Alexander Burns

Masters Theses

Two of the most recognizable competitors in this new era of Euro-American competition are Airbus and Boeing. These two competitors are the world’s leading aircraft manufacturers and their competition is shaping the face of the commercial aviation industry. The competition between these two companies is for the “World’s Leading Commercial Airline Manufacturer.” This title is currently held by Airbus who has lead yearly production and taken more orders over the past three years.

Boeing has fallen behind in being the technological leader due to a falling budget, poor industrial model, and ethical practices. As a result of losing ground to …

New Wings For The T-38: A Computational Performance Evaluation Of The T-38 Aircraft With A New Wing Design, John M. Kanuch

Masters Theses

Despite the recent improvements to the T-38 airframe and engines, the United States Air Force is still seeking ways to improve the aircraft’s takeoff, cruise, and landing performance. One potential way to improve the performance is to change the design of the wing. Using the Digital Performance Simulation aircraft-performance computer code, a T-38C performance evaluation sensitivity study was performed by parametrically varying the wing design. The computer model was a three degree of freedom, pointmass, batch simulation. The design changes investigated included varying aspect ratio with constant wing area, varying wing area with constant aspect ratio, and the addition of …

Risk Analysis Of Decentralized Wastewater Design Flows, Patrick Andrew Dobbs

Masters Theses

Decentralized wastewater treatment systems are often designed at flows of either 284 L/person/d (75 gal/person/d) or 568 L/bedroom/d (150 gal/bedroom/d). Water use data suggest that designing systems at these flow rates can lead to overly conservative designs. A study quantifying the risk of failure (exceeding a system design flow) was needed to create a design basis for future systems. The objectives of the study were to quantify the risk of failure of decentralized system design flows depending on the number of residences served by a system and to develop new guidelines for design flows of cluster systems based on quantifiable …

Optimization Of Digital Filter Design Using Hardware Accelerated Simulation, Getao Liang

Masters Theses

iii Abstract The goal to this research was to develop a scheme to optimize a digital filter design using an optimization engine and hardware-accelerated simulation using a Field Programmable Gate Array (FPGA). A parameterizable generic digital filter, which was fully implemented on a prototyping board with a Xilinx Virtex-II Pro xc2vp30-7-ff896 FPGA, was developed using Xilinx System Generator for DSP. The optimization engine, which actually is a random candidate generator that will eventually be replaced by a differential evolution engine, was implemented using MATLAB along with a candidate evaluator and other supporting programs. Automatic hardware co-simulations of 100 candidate filters …