Engineering Commons^™

Low Pressure Chemical Vapor Deposition Of Silicon Carbonitride Films From Tri(Dimethylamino) Silane, Rajive Shah

Theses

A literature study to investigate the incorporation of silicon into SiC and Si₃N₄ films from various organosilanes was carried out. The Arrhenius activation energy for the synthesis of silicon, silicon carbide and silicon nitride films from various organosilanes range from 165-210 kJ/mol. A review of recent studies have indicated that silicon deposition is the rate determining step in the synthesis of silicon from silane. It is proposed here that this hypothesis can be established for the synthesis of silicon carbide, silicon nitride and silicon carbonitride film. Limited experiments indicated that the silicon deposition is a rate determining …

Decontamination Of Aquifers Via Air Sparging/Biofiltration : An Experimental Study, Armando Mora Tellez

Theses

In this study experiments were performed in order to show feasibility of an integrated air sparging/biofiltration process for cleaning contaminated groundwater. Feasibility was also meant in the sense of meeting regulatory constraints. Using toluene as model compound and changing flowrates for the sparged air, it was shown that despite fluctuations in the toluene concentration at the inlet of the biofilter, the concentrations at the outlet of the unit were essentially constant over long periods of time and remained below the levels dictated by environmental regulations. However an increase in outlet concentrations at levels not meeting regulatory constraints was observed after …

Computer Simulation Of Cerebrovascular Circulation : Assessment Of Intracranial Hemodynamics During Induction Of Anesthesia, Steven D. Wolk

Theses

The purpose of this project was to develop a computer model of cerebrovascular hemodynamics interacting with a pharmacokinetic drug model to examine the effects of various stimuli during anesthesia on cerebral blood flow and intracranial pressure.

The mathematical model of intracranial hemodynamics is a seven compartment constant volume system. A series of resistances relate blood and cerebrospinal fluid fluxes to pressure gradients between compartments. Arterial, venous, and tissue compliance are also included. Autoregulation is modeled by transmural pressure dependent arterial-arteriolar resistance. The effect of a drug (thiopental) on cerebrovascular circulation was simulated by a variable arteriolar-capillary resistance. Thiopental concentration, in …

The Study Of Permeability In Concrete, Jie Yuan

Theses

In this study, samples of regular, high performance, expansive and the polymer concrete and mortar were prepared for test of permeability and mechanical property. In the permeability measurement, water and an aqueous chemical solution were employed as the permeant.

The test results of the samples, ranging from 5.7 x 10-9 cm/sec to 1.0 x cm/sec for the permeability and 3800 psi to 10600 psi for compression strength, indicated that the polymer coated concrete has the lowest permeability among the concretes and high performance concrete has the highest compression strength . The finding leads to the possibility that a high strength …

An Analytical Approach To Toxic Substance Replacement In Support Of Pollution Prevention, Ithan B. Zimmer

Theses

In support of pollution prevention and in accordance with Executive Order 12356 concerning pollution prevention, all federal agencies must comply with the Toxic Release Inventory (TRI) chemical release reduction and pollution prevention planning. The inventory lists hundreds of chemicals and choosing those to replace and finding actual replacement chemicals or procedures is not always clear. This study focuses on an analytical approach to this problem by understanding the application of two substances. The representative chemicals are two volatile organic compounds (VOC), ethyl ether and ethanol, used as solvents in ammunition manufacturing.

Thirteen military specifications provide the cases involving ether. Ethanol's …

Settlements Due To Arid Collapsible Soils, Heather L. Devine

Dissertations and Theses

The arid alluvial deposits common to the western United States frequently undergo moderate to severe collapse when wetted that can threaten or destroy the stability of structures that are founded on such soils. Additionally, in some areas collapse has been known to occur due to overburden stresses alone. As development expands in these areas a method to estimate the degree of this collapse is essential.

Current settlement methods are reviewed and evaluated as they apply to collapsible soils, providing a basis for the development of a proposed settlement method for determining collapse. To aid in the determining the basis for …

The Effects Of The Aging Process On The Mechanical Properties In Al-Cu-Li(2195) Alloy, Michael Abernathy

Electronic Dissertations and Theses

The Alumniurn-Copper-Lithi arn (Al-C u-Li) alloy s are used as aero space materi als du e to thei r low den sity , hig h modulus of elasticity, good resistance to fatigue crack propagation , and excelle nt cryogenic properties. In the current experime nt, Al-Cu-L i (2 195) allo y is se lected to study the effect of the ag ing process on mechanical propertie s. The 2 195 all oy in sheet form is supplied by Lockheed-Marti n, New Orleans. The as-received 2 195 alloy sheet is solution-treated at 5 10 ° C for one hour followed by …

Freezing Point Mobile Munitions Assessment Sytem: Thermal Chamber Redesign, Sara Gifford, Preston Harris

Undergraduate Honors Capstone Projects

The Army is actively investigating non-intrusive methods to identify six chemical weapons agents. The chemical munitions in question are often found scattered across military bases and other facilities. These non-stockpile munitions are specifically targeted for identification using the mobile munitions assessment system. This program is being administered by the Idaho National Engineering Laboratory.

Cr9000 Measurement And Control System Pcmcia-Ata Software Device Interface, Ryan Jon Soulier

Undergraduate Honors Capstone Projects

Many industries have a need for high speed data collection of a large amount of data. For example, the auto industry extensively tests vehicles for resistance to stress, temperature, and moisture. Campbell Scientific, Inc. (CSI) has built the CR9000 measurement and control system that fills this need by being able to measure up to 252 separate sensors at a sustained rate of up to ten thousand samples per second.

The CR9000 system lacks efficiency because it has only a small, fixed amount of memory and is capable of recording data only for a short period. Older devices designed by CSI …

Structural Design Of A Crashworthy Energy Absorbing Passenger Seat For A Large Transport Aircraft Using Large Displacement, Nonlinear Material Finite Element Analysis, Javier Fuentes

Master's Theses - Daytona Beach

Federal Aviation Regulations certification criteria for transport aircraft seats require performing dynamic tests using anthropomorphic test dummies. Floor decelerations of the tests are 16g forward with the seat tracks misaligned by up to 10 degrees and 14g downward at a pitch angle of 30 degrees. In this project the dynamic response of the passenger/seat/restraint system is modeled using nonlinear finite element analysis. The interference between a dummy model and the seat is modeled using a contact interaction algorithm. This algorithm did not converge and multiple-point constraints were used to transfer the dummy's inertia load. This approach was validated with the …

Training Strategies For Critic And Action Neural Networks In Dual Heuristic Programming Method, Christian Peter Paintz

Dissertations and Theses

This thesis discusses strategies for and details of training procedures for the Dual Heuristic Programming (DHP) methodology. This and other approximate dynamic programming approaches (HDP, DHP, GDHP) have been discussed in some detail in the literature, all being members of the Adaptive Critic Design (ACD) family. The example applications used here are the inverted pendulum problem and a fully nonlinear constant velocity bicycle steering model. The inverted pendulum has been successfully controlled using DHP, as reported in the literature. This thesis suggests and investigates several alternative D HP training procedures and compares their performance with respect to convergence speed and …

The Synthesis, Characterization, And Cell Seeding Of A Collagen/Hydroxyapatite Porous Scaffold For Treatment Of Osseous Defects, Kim Rachel Patterson

All Theses

The need for finding a bone graft substitute stems from the fact that approximately 200,000 bone grafting procedures are performed annually in the U.S. alone. Although biological grafting options (i.e. autografts & allografts) exist, they do suffer from inherent problems. These include limited resources, costly processing, and potential for pathogen transfer. Thus, investigators have sought synthetic alternatives.

The objective of this research was to utilize hydroxyapatite (HA) and collagen, both analogues to the major constituents of bone, to fabricate an optimal synthetic osteoconductive/osteoinductive bone scaffold. Current attempts by other investigators to combine the two materials have been met with some …

Evaluation Of Two-Dimensional Hydraulic Modeling In A Natural River And Implications In Instream Flow Assessment Methods, Karl L. Tarbet

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Logan River was used as a study site to assess the capabilities of two-dimensional depth-averaged hydraulic modeling in the x-y plane of a natural river for use with instream flow studies. Data were collected to spatially represent the study reach with depth, velocity, northing, easting, elevation, and substrate values using a total station and electronic velocity meter. Computational finite element meshes were generated using four different density levels of geometry data to examine the relationship between field data density and computational mesh on geometry errors. Geometry errors were found to be related to smoothing effects, which removed complex channel …

Super-Heterodyne C-Probe Design And Implementation, Scott A. Heritsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Modern advances in chip design and implementation have provided atmospheric scientists with the tools needed to advance the evolution of atmospheric probes, especially the impedance probe. The impedance probe measures the in-phase and out-of-phase components of the antenna's current with respect to the applied sinusoidal steady-state voltage. Through the integration of super-heterodyne circuitry with previous impedance probe designs, I was able to transfer the in-phase and out-of-phase components of an antenna's impedance in a plasma from 3 MHz to 23.25 KHz. By reducing the frequency of the information signal, it was easier to detect the in-phase and out-of-phase components. The …

Predicting Resistance And Stability Of Vegetation In Floodplains, David E. Werth Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To calculate flow or depth in a waterway, it is necessary to accurately determine the flow resistance. Past research has made considerable progress in predicting the roughness of nonvegetated uniform channels based on both theoretical and experimental investigations. However, to determine the flow resistance associated with vegetated compound flow channels and floodplains, the effects of the vegetation must be considered.

Recent advancements have led to greater understanding of the effects of partially submerged uniform vegetation in a waterway. However, to accurately determine flow resistance, it is imperative that the effects of both submerged and partially submerged vegetation be taken into …

Evaluating The Feasibility Of An Intermodal Transportation Facility In Chattanooga, Murugan Auruvankulam-Palani

Masters Theses and Doctoral Dissertations

This research develops a mathematical model based on linear programming techniques to evaluate the feasibility of developing an intermodal transportation facility in Chattanooga. Transportation resources in and around Chattanooga were studied, and the opportunities available for developing business by a transportation facility are analyzed. Large quantities of goods are shipped in and out of Chattanooga by trucks in either trailers or containers. In order to transfer goods in container or trailer from one mode of transportation to another, specific handling equipment is needed. Mobile cranes present in some transportation terminals in Chattanooga can transfer goods in small units only, but …

Testing Of Solid Rocket Propellants With An Ultrasonic Transducer, Bryan Rasmussen

Honors Capstone Projects and Theses

No abstract provided.

Tnt-Contaminated Soils Remediation For Volunteer Army Ammunitions Plant, Janice Tevonia Russell Horn

Masters Theses and Doctoral Dissertations

Many facilities involved in the production of munitions, or with a history of munitions production or storage, are faced with the remediation of residual explosives in soil, groundwater and process wastewater. This requirement has become particularly prevalent with the closing of many military installations across the country. The Volunteer Army Ammunition Plant (V AAP) is a 6,681 acre Government owned and contractor-operated facility for the production and storage of trinitrotoluene (TNT). Two (2) technologies were investigated for TNT (nitroaromatic explosive) contaminated soils remediation. The technologies are phytoremediation and thermal incineration. Phytoremediation is an in-site wetlands-type remediation which uses plants. Thermal …

Surface Micromachined Pressure Sensors, William P. Eaton Iv

Electrical and Computer Engineering ETDs

Surface micromachined pressure sensors were designed, modeled, fabricated, and tested. They employed a piezoresistive transduction mechanism and were based upon circular diaphragms, which vary from 50 to 1000 μm in diameter and 1 to 2 μm in thickness. The piezoresistors were placed in Wheatstone bridge configurations to provide simple signal amplification and first order temperature compensation.

Of the different micromachining techniques, surface-micromachining has the advantage of being the most similar to integrated circuit manufacturing. Hence an existing IC equipment set can be used to create mechanical structures. Furthermore, the monolithic integration of a mechanical device with control electronics is simpler …

Closed Form Solution Of The Wave Equation For Piles, Don C. Warrington

Masters Theses and Doctoral Dissertations

This thesis details the research into the one-dimensional wave equation as applied to piles used in the support of structures for civil works and driven using impact equipment. Since the 1950's, numerical methods, both finite difference and finite element, have been used extensively for the analysis of piles during driving and are the most accepted method of analysis for the determination of driving stresses, dynamic and static resistance of piles. In this thesis the wave equation is solved in a relatively simple closed form without recourse to numerical methods. A review of past efforts to solve the wave equation in …

Single Row Routing: Theoretical And Experimental Performance Evaluation, And New Heuristic Development, David A. Hysom

Computer Science Theses & Dissertations

The Single Row Routing Problem (SRRP) is an abstraction arising from real-world multilayer routing concerns. While NP-Complete, development of efficient SRRP routing heuristics are of vital concern to VLSI design. Previously, researchers have introduced various heuristics for SRRP; however, a comprehensive examination of SRRP behavior has been lacking.

We are particularly concerned with the street-congestion minimization constraint, which is agreed to be the constraint of greatest interest to industry. Several theorems stating lower bounds on street congestion are known. We show that these bounds are not tight in general, and argue they may be in error by at least 50% …

Gate Transient Equations For Digital Bicmos Circuits, Beshara Elmufdi

Honors Capstones

No abstract provided.

The Pratt & Whitney 4060: Power For The Future, Gregory Sumner

Honors Theses

The Pratt & Whitney 4000 engine platform is considered the most economical turbofan engine in its class. It is advertised as providing the most efficient service and the most reliability for air carriers. United Airlines utilizes the company's engines. The paper begins with basic turbine engine theory and moves on to engine classifications, where the Pratt & Whitney 4060 is introduced. The systems are covered in detail. Maintenance areas of service and inspections are described to show how personnel may interact with the computers. Finally, a description of activities during the author's internship describe the interesting facets of a semester …

Telemetric Torque Measurement System, Jason Joseph, Francisco Sinta, Jeff Williams

Honors Theses

The Telemetric Torque Measurement System(TTMS) was designed to measure the torque produced by a snowmobile engine. The design of the TTMS was refined and modified in stages, leading to the final design. The TTMS consists of two basic sections: the transmitter section and the frequency demodulator section. The transmitter section effectively measures the torque on a snowmobilejack-shaft. The torque signal is converted into a voltage which is then fed into a voltage to frequency converter and converted into an audio tone. This tone is broadcast in the FM broadcast band via an FM transmitter. An FM receiver then receives the …

An Optimization Technique Of Airlines' Seat Inventory Management, Husam Abdallah Mahmoud Fanasheh

Master's Theses - Daytona Beach

This study consisted of a simulation to maximize an airline's Origin- Destination revenues. It has been hypothesized that Linear Programming is capable of maximizing airlines' networks revenues. Simulation was performed with Linear Interactive Discrete Optimizer (LINDO). This project was designed to consider different fares and its classes along with multi flight connections. The seats' allocation process came out with the maximum possible revenues, and enough flexibility in terms of changing such allocation to work around competition and trends. Results came supportive to the hypothesis. Sensitivity analysis provided our model with a tool to modify and change different variables, like fares, …

Development And Initial Evaluation Of An Acoustic Apparatus Used For Testing Of Farfield Noise Emitted By A Propeller In A Short Duct, R. Duane Oleson

Master's Theses - Daytona Beach

The purpose of this thesis was to design, construct and evaluate an apparatus which was used for testing of acoustic emissions by a propeller in a short duct. An apparatus was designed based on a combination of acoustic principles and a desire to be able apply the knowledge gained to a practical application such as an ultralight aircraft in an effort to reduce the overall noise levels emitted. The apparatus consisted of a 35 horsepower ultralight engine, a four bladed ultralight propeller, and a duct constructed of a foam core covered with fiberglass. Initial evaluations compared noise levels from the …

Passenger Knowledge Of Airline Safety Icons: A Cultural Study, Bridget L. Mattingly

Master's Theses - Daytona Beach

The purpose of this study was to examine the relationship between Japanese, Korean, and American cultures in their ability to comprehend icons used in airline passenger safety information. The 116 subjects were outbound international airline passengers traveling from San Francisco International Airport to either Japan or Korea. The instrument used contained thirteen icons similar to those on current passenger safety briefing cards. Subjects were asked to identify the icons as accurately as possible. Answers were graded on a three point ordinal scale, and frequency data were obtained. To test for significant differences between cultures, the data were analyzed through use …

The Design And Experimental Optimization Of A Wingtip Vortex Turbine For General Aviation Use, Andrew Roberts

Master's Theses - Daytona Beach

A wingtip vortex turbine (WVT) is an induced drag reduction device that straightens the vortex flow (reducing induced drag and wake turbulence) and also produces a thrust force component. The WVT also has the advantage of extracting the rotational energy of the vortex to turn a generator, which could be used to power onboard applications during normal or emergency flight operations. A 1/4-scale model of a thrust-producing WVT has been designed and tested in a wind tunnel for optimal drag reduction and power generation for general aviation aircraft — specifically, a Piper Cherokee — in both a stationary and a …

Evolutionary Codesign, Karthikeyan Ethirajan

Masters Theses

We present our approach to hardware/software partitioning for embedded systems based upon Evolutionary Algorithms. We have implemented it in a CAD tool, EvoC - Evolutionary Codesign which does automatic hardware/software partitioning of real-time embedded systems at the system level. Our objective is to find good design configurations that are tuned towards user's preferences. We are able to explore a large, often intractable design space using Evolutionary Algorithms while evaluating solutions having multiple and sometimes conflicting attributes in the light of Multi-Attribute Utility Theory. EvoC provides a generic format for specifying a wide variety of design problems and the implementation assumes …

Cooperative Power-Limited Optimal Rendezvous Between Many Spacecraft, Virginie Guerre

Master's Theses - Daytona Beach

The minimum fuel rendezvous problem between several power-limited low-thrust spacecraft neighboring either a circular or an elliptic orbit is investigated. Both cooperative and non cooperative maneuvers are studied. The maximum principle of Pontryagin is applied to the optimal control rendezvous problem of several spacecraft. The gravitational field models investigated are the Clohessy-Wiltshire field and the inverse-square gravity field. Numerical solutions using a shooting method and the finite difference method are used in order to determine the trajectories of the spacecraft. Unlike previous investigations, this work is not restricted to a rendezvous of two spacecraft around a circular orbit, but a …