Engineering Commons^™

Explicit And Iterative Lqg Controller Design, Min-Hung Hsiao

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation presents two new LQG controller designs, namely, explicit and iterative designs. For the explicit design, the explicit solutions to the corresponding Riccati equations of controller design for large structures with collocated rate sensors and actuators are derived. Numerically solving the Riccati equations for state feedback and state estimation is no longer required. Since the number of design parameters for either state feedback or state estimation equals the number of controlled modes, the performance of each mode can be easily adjusted. NASA's Spacecraft COntrol Laboratory Experiment (SCOLE) configuration is used to demonstrate the effectiveness of the explicit design.

For …

Unsteady Flow Simulations About Moving Boundary Configurations Using Dynamic Domain Decomposition Techniques, Guan-Wei Yen

Mechanical & Aerospace Engineering Theses & Dissertations

A computational method is developed to solve the coupled governing equations of an unsteady flowfield and those of rigid-body dynamics in six degrees-of-freedom (6-DOF). This method is capable of simulating the unsteady flowfields around multiple component configurations with at least one of the components in relative motion with respect to the others. Two of the important phenomena that such analyses can help us to understand are the unsteady aerodynamic interference and the boundary-induced component of such a flowfield. By hybridizing two dynamic domain decomposition techniques, the grid generation task is simplified, the computer memory requirement is reduced, and the governing …

Interferometric Determination Of The Quadratic Electro-Optic Coefficient Of Nitrobenzene, Harshad P. Sardesai, William C. Nunnally, P. F. Williams

P. F. (Paul Frazer) Williams Publications

An interferometric method that was used to measure the electro-optic s₁₁ coefficient of nitrobenzene is presented. The method uses a Mach-Zehnder interferometer arrangement that produces a finite fringe interferogram. A nitrobenzene Kerr cell is placed in one arm of the interferometer and a pulsed high voltage is applied to the two rectangular electrodes. The voltage application causes the fringe image to shift in time, and this fringe shift is measured by a streak camera that streaks the fringe image across a slit. The streak start time is chosen before the application of the voltage pulse and ends after the …

First Shell Substitution Effects: Diglyeidyl Ether Of Bisphenol A Cured With 4,4'-Diaminodiphenylmethane, Hossein Noureddini, Delmar C. Timm

Papers in Molecular Chemistry

First shell substitution effects were incorporated into a kinetic reaction model descriptive of the polymerization of an epoxy resin formulated from diglycidyl ether of bisphenol A and 4,4'-diaminodiphenylmethane. Analysis of populaiion density distribution dynamics for the hardener and several oligomers in the sol fraction showed that the reactivity of secondary amino hydrogens is less than the reactivity of primary amino hydrogens.

Dynamic Task Scheduling For The Atamm Multicomputer Operating System Using Embedded Firmware On Microcontrollers, Sudhir Sastry

Electrical & Computer Engineering Theses & Dissertations

A dynamic task scheduling strategy for the distributed processing of large grain dataflow algorithms using embedded firmware on an ATAMM testbed consisting of interconnected microcontrollers is presented in this thesis. The ODU/NASA developed Algorithm to Architecture Mapping Model, ATAMM, uses marked graph models to specify data and control flow for the execution of iterative, deterministic large grain dataflow algorithms in a multicomputing environment. The testbed consists of a bank of four 68HC11 microcontrollers that communicate over a token bus. The token bus arbitration scheme used is contention free and well suited for real-time computing applications. The execution of data flow …

Optimal Active And Passive Control Design For A Slewing Piezoelectric Laminate Beam, Travis V. Dubois

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis presents the development and experimental verification of a distributed parameter model for a slewing beam system with piezoelectric actuators and sensors. Also presented is the development of an optimal active control synergism which employs IMSC, (Independent Modal Space Control) and an optimally designed, viscoelastic damping treatment. The beam is pinned at the proximal end and patches of thin piezoelectric laminates are attached to its surface. Formulation is general enough to allow the patches to be located anywhere on the beam's surface. A viscoelastic material with a constraining layer covers the rest of the beam. The differential equation of …

Three-Dimensional Aerodynamic Shape Optimization Using Discrete Sensitivity Analysis, Gregory Wayne Burgreen

Mechanical & Aerospace Engineering Theses & Dissertations

An aerodynamic shape optimization procedure based on discrete sensitivity analysis is extended to treat three-dimensional geometries. The function of sensitivity analysis is to directly couple computational fluid dynamics (CFD) with numerical optimization techniques, which facilitates the construction of efficient direct-design methods. The development of a practical three-dimensional design procedures entails many challenges, such as: (1) the demand for significant efficiency improvements over current design methods; (2) a general and flexible three-dimensional surface representation; and (3) the efficient solution of very large systems of linear algebraic equations. It is demonstrated that each of these challenges is overcome by: (1) employing fully …

Bs News

Building Services Engineering

No abstract provided.

Optimization Of Electron-Beam Activated Gaas Switches, Raymond Jack Allen Iii

Electrical & Computer Engineering Theses & Dissertations

The use of electron induced luminescence (cathodoluminescence) in gallium arsenide offers the possibility to modulate the conductance of the material on a timescale of nanoseconds and with a pulse rate of MHz, through modulation of an electron-beam current. This ionization mechanism allows the utilization of semi-insulating GaAs in fast, high power closing and opening switches. The efficiency of the switches is determined by the hold-off voltage of the GaAs switches, and by the conversion efficiency of electron energy into (useful) photon energy. Studies of the dark-current and the electron-beam induced conductance in semi-insulating GaAs have been performed in order to …

Derivative Absorption Spectroscopy With Tunable Laser Diodes, Andrew D. Jackson

Electrical & Computer Engineering Theses & Dissertations

Derivative Absorption Spectroscopy using tunable diode lasers provides a non­ intrusive, sensitive, and convenient method for monitoring gaseous characteristics such as concentration, temperature, and flow velocity. In addition, the specie type can be identified, and if the equation of state is known, pressure may be deduced.

This technique was used on molecular oxygen, in which the rovibronic transitions of the A-band ( b ¹ ∑_g ⁺ ← X ³ ∑g ^- ; v^II = O, v^I = O) were probed. Phase sensitive detection with a lock-in amplifier provides the flexibility to examine lineshape derivatives; several such derivative …

Determination Of Density Of Trap States At Y2O3-Stabilized Zro2/Si Interface Of Yba2Cu3O7-Δ/Y2O3-Stabilized Zro2/Si Capacitors, Jianmin Qiao, Kuohsu Wang, Cary Y. Yang

Electrical and Computer Engineering

Yba₂Cu₃O_7-δ/yttria‐stabilized zirconia (YSZ)/silicon superconductor‐insulator‐semiconductor capacitors are characterized with current‐voltage and capacitance‐voltage (C‐V) measurements at different temperatures between 223 and 80 K. As a result of ‘‘freezing’’ of mobile ions in YSZ, effects of trapped charge at the YSZ/Si interface dominate the device electrical properties at superconducting temperatures. Density of interface states and its temperature dependence are determined using a modified high frequency C‐V method, in which the temperature dependences of band gap, Fermi level, and active dopant and intrinsic carrier concentrations are considered. At superconducting temperatures, e.g., 80 K, the interface state density within …

A Design Methodology For A Multi-Fpga Based Rapid Prototyping System, William Eatherton

Opportunities for Undergraduate Research Experience Program (OURE)

The movement of universities from university-created digital design software to commercial design tools has resulted in a need for a revision of existing rapid prototyping systems. The rapid prototyping system created at North Carolina State University (NCSU) and centered on a FPGA-based board (called the Anyboard), was revised to use Mentor Graphics, a sophisticated industrial EDA tool, rather than board specific software. To provide a guide for future students at UMR and other schools using the Anyboard, an example design was created with Mentor Graphics to route data between a PC bus, SRAMs, and an arithmetic logic unit.

The Feasibility Of Using Piezoelectric Flap Actuation In The Active Control Of Flutter, Aaron Laws

Opportunities for Undergraduate Research Experience Program (OURE)

Wing flutter is one of the most important and dangerous phenomenon faced by aircraft structural design engineers. Flutter is a self exciting aeroelastic phenomenon in which portions of an aircraft structure begin to oscillate with exponentially growing amplitudes, produced by the changing aerodynamic forces and moments brought about by the deformation of the structure. There exists a characteristic flight speed, known as the flutter speed, where the structure exhibits sustained harmonic motion, ie. zero damping. Below this velocity, the vibration of the structure due to a perturbation will decrease exponentially, while above this velocity, the vibration will increase exponentially, eventually …

Preliminary Efforts Towards The Analysis Of Unsteady Pressure Measurements Around Wing Models In Transonic Flow, Stephen Witherspoon

Opportunities for Undergraduate Research Experience Program (OURE)

A computer code was developed to implement methods of analyzing unsteady pressure measurements acquired from a wing model immersed in transonic flow. The code uses the fast Fourier Transform to identify phase changes and magnitudes of dominant frequencies over time in the unsteady pressure coefficients. The transformed data, as well as the raw data, are graphed and the results explained in detail identifying features depicted in the graphs. Also, the code performs some simple statistical calculations and smoothes the data to remove insignificant noise in the signal, if desired.

High-Pressure Wateijet Technology: A Review And Design Of High-Pressure Hybrid Drillbits, Azmi Zainal Adnan

Opportunities for Undergraduate Research Experience Program (OURE)

The petroleum industry has seen many technological advances since oil was first discovered in the 19th century. Some of the current technological advances in the industry include cuttings transport, drillbit design, logging, and horizontal and directional drilling. Currently, research projects are being done at UMR to find ways to further reduce drilling costs and develop new technology that could improve the drilling effectiveness. One such project is the development of high- pressure waterjet / hybrid bits to replace the conventional mechanical drillbits. In this design, the advantages of waterjet penetration are combined with those of mechanical teeth cutting action..

At …

An Artifically Intelligent Word Recognizer To Control Appliances And Switches: The Home That Listens To Your Every Command, Joseph Bauer, Rick Steurer

Opportunities for Undergraduate Research Experience Program (OURE)

The most natural and informal means of communication and control is speech communication. Therefore, it also goes to say that control of home appliances, stereo, computer, and heating thermostat to name a few will naturally tend to this form of control.

A word recognition home controller was designed, constructed, and tested successfully. This paper will discuss the low-cost overall design, implementation, and results of a presently constructed and working "home controller." The results of this successful project in voice control are very promising and agree with the original hypothesis: A home that listens to your command is very much a …

Determination Of Flow Quality And Boundary Layer Thickness In Variable Density Wind Tunnel, Marshall Philips

Opportunities for Undergraduate Research Experience Program (OURE)

The purpose of this paper is to measure the velocity profile in the test section of the Variable Density Wind Tunnel (VDWT). The hot wire anemometer is chosen to measure the velocity profile because of its accuracy and its ability to be moved relatively close to the upper and lower surfaces of the wind tunnel. Special attention is paid to the uniformity of flow velocity in the free stream and whether it varies with position in the tunnel. The measurements were taken at two different stations, two different temperatures, and three different speeds.

Results indicate that the velocity profiles are …

Sporomorphs And Palynological Interpretations Of Lower Oligocene Strata From The Eastern Gulf Coast, U.S.A., Lisa M. Reeves

Opportunities for Undergraduate Research Experience Program (OURE)

The Vicksburg Group in the eastern Gulf Coast of the United States belongs to one of the most complete and continuous Paleogene strata in the world. Previous studies in this region have neglected the rich palynomorph assemblages of the Lower Oligocene units of the Vicksburg Group. Four samples from Wayne County Mississippi were analyzed for palynological information on the Vicksburg Group. The initial objective of the study was to understand the principles of palynology and the basis for sporomorph identification. A minimum of 300 specimens were counted per slide to determine the distribution of sporomorphs in the sediments. Two hundred …

Development Of A Launch System For Performance Studies Of Small Aircraft Models, James J. Schneider

Opportunities for Undergraduate Research Experience Program (OURE)

This paper presents a design of a launching system that can be employed for performance studies on small aircraft models. Further the article describes a design and development of an aircraft model for use with the system. initial analysis and testing of the system using the designed aircraft model will be presented.

Design, Construction, Calibration And Applications Of An Apparatus Which Conducts The Large Missle Impact Test, John Schroeder

Opportunities for Undergraduate Research Experience Program (OURE)

Prior to Hurricane Andrew (August 1992), the South Florida Building Code maintained provisions for the design of building openings based on wind pressure only. Hurricane Andrew provided evidence of other failure modes, including windborne debris and internal pressure. Following the hurricane, several changes were made to building codes in South Florida. One addition requires building openings to resist windborne debris. A missile impact test incorporated into recently accepted Dade and Broward Counties editions of the South Florida Building Code states a window, door, or external protection device shall resist a prescribed number of impacts from a nine pound 2x4 timber …

The Effect Of Spatial Variation Of The Turbulent Prandtl Number And Calculation Methods For Heat Transfer In High Mach Number Flows, Thomas W. Scott

Opportunities for Undergraduate Research Experience Program (OURE)

The effect of using various spatial distributions of the turbulent Prandtl number on the predicted surface heat transfer in the numerical simulation of Mach 4 flat plate flow is studied. The spatial distribution of the turbulent Prandtl number is shown to have a small effect on surface heat transfer, hence suggesting that the standard assumption of a constant turbulent Prandtl number is acceptable for high Mach number boundary layer type flows. In addition, a wall-cell control volume technique for computing heat transfer shows superior predictive capacity across the Reynolds number range when compared to the conventional calculation of surface heat …

Interactive Multimedia Applications For The Correlations Of Petroleum Fluids Properties, Herman Smith Iii

Opportunities for Undergraduate Research Experience Program (OURE)

Interactive Multimedia Applications for the Correlations of Petroleum Fluids Properties is a truly interactive and multimedia computer application designed to better help students taking the class "The Properties of Petroleum Fluids", Petroleum Engineering 141. This computer program incorporates error and information voice messages, control over three different computer applications (HyperCard 2.2, Mathcad V3.1, and DeskPaint™ V3.2), three-dimensional multi-coloration, pop-up graphics, directional buttons, object/label-oriented programming, and floating palettes. This creates one computer application to calculate petroleum properties versus the use of multiple, often crowded graphs.

Development Of A Bill Of Materials From The Pdxi Data Models, Bryan A. Stanford

Opportunities for Undergraduate Research Experience Program (OURE)

The research on the development of a bill of materials has resulted in the construction of a portion of the working data model, as designed in theory by the Process Data Exchange Institute (PDXI). The theoretical object model can be found in The PDXI Data Models [1]. It was necessary to develop this working data model in order to be able to produce the bill of materials. The bill of materials was created with the help of the software package Paradox for Windows (version 4.0).

Laser Assisted Pd Seeding For Electroless Plating On Siq2, A. G. Schrott, B. Braren, Ravi F. Saraf

Ravi Saraf Publications

Excimer laser pulses with wavelengths of 248 and 308 nm were used to selectively seed Pd on SiO₂ surfaces, making them suitable for electroless plating. This novel seeding process for insulating materials is accomplished with the sample immersed in the seeding solution, and occurs only on the areas of the substrate that are illuminated (through the liquid) by the laser light. The Pd content of the seeded samples increased with the number of pulses, but was rather independent of repetition rate. The deposition rate showed a dependence with wavelength consistent with a defect driven mechanism for electron excitation through …

Retrieval Of Sizes And Total Masses Of Particles In Volcanic Clouds Using Avhrr Bands 4 And 5, Shiming Wen, William I. Rose

Department of Geological and Mining Engineering and Sciences Publications

The advanced very high resolution radiometer (AVHRR) sensor on polar orbiting NOAA satellites can discriminate between volcanic clouds and meteorological clouds using two-band data in the thermal infrared. This paper is aimed at developing a retrieval of the particle sizes, optical depth, and total masses of particles from AVHRR two-band data of volcanic clouds. Radiative transfer calculations are used with a semi-transparent cloud model that is based on assumptions of spherical particle shape, a homogeneous underlying surface, and a simple thin cloud parallel to the surface. The model is applied to observed AVHRR data from a 13-hour old drifting cloud …

Real Life Applications Of Photovoltaic Power To Hurricane Andrew Relief, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

On August 24, 1992, Hurricane Andrew struck the coast of South Florida and devastated Dade County leaving several hundred-thousand people homeless. Over a million residences were without electrical service, functional water and sewage systems and medical services for days and weeks in the aftermath of the storm. Emergency management teams, medical personnel, the military and countless public and private organizations staged a massive relief effort.

The staff at the Florida Solar Energy Center and SANDIA National Laboratory responded to the disaster with photovoltaics (solar electric) powered equipment to assist in the relief effort. Electricity generated by these systems were used …

Acuta Enews March 1994, Vol. 23, No. 3

ACUTA Newsletters

In This Issue

Board reprt

President's message

Baltimore update

Improvements at the University of Chicago

21st Century technology

Resource Library is growing

Technology Transfer: A View From The Trenches, Harvey Drucker

RISK: Health, Safety & Environment (1990-2002)

Dr. Drucker, who has lab-wide responsibility for technology transfer at Argonne National Laboratory, argues that transferring rights in discoveries made through tax supported research to private entities can contribute to public welfare in many ways.

Effects Of Time Of Deoxyribonucleic Acid Microinjection On Gene Detection And In Vitro Development Of Bovine Embryos, A.E T. Sparks, R S. Canseco, C G. Russell, J L. Johnson, H D. Moll, William H. Velander, Francis C. Gwazdauskas

Papers in Biotechnology

In vivo fertilized embryos were surgically collected from superovulated dairy cows to evaluate microinjection on embryo development and utilized the polymerase chain reaction technique for selection of transgenic embryos. Seventy-two percent of the embryos with visible pronuclei or nuclei were microinjected with DNA, and the remaining 28% served as uninjected controls. All embryos were cocultured with bovine oviductal epithelial cells. Mean final development scores of embryos within the same initial cell stage at collection were unaffected by microinjection. After 144 h of culture, 45% of the microinjected embryos developed to the morula or blastocyst stage. The transgene was detected in …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 3, March 1994, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A twelve page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.