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Theses/Dissertations

1992

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Articles 1 - 30 of 211

Full-Text Articles in Engineering

Turbomachine Stability And Forced Response Prediction, Leland Bert Clark Dec 1992

Turbomachine Stability And Forced Response Prediction, Leland Bert Clark

Open Access Theses

A mathematical model is developed and utilized to analyze turbomachine cascade flutter and forced response. The flutter boundary, defined as the largest value of reduced frequency at which flutter occurs for a given cascade, was evaluated for single degree of freedom torsional oscillation as well as coupled bending and torsional oscillations. The maximum amplitude of forced response in bending and torsion was also considered. The unsteady aerodynamic lift and moment coefficients were determined from unsteady aerodynamic flow models for subsonic flow, supersonic flow with a subsonic axial component and supersonic axial flow. The effect of changing the Mach number, stagger ...


Utilizing Instructional Design Constructs To Enhance Computer-Based Instruction In Air Traffic Controller Training, Theodore Scott Rhoads Dec 1992

Utilizing Instructional Design Constructs To Enhance Computer-Based Instruction In Air Traffic Controller Training, Theodore Scott Rhoads

Master's Theses - Daytona Beach

This study demonstrates that a computer-based instructional design format is appropriate for novice air traffic control (ATC) training. The computer presents the student with small amounts of information in tutorial and drill and practice sequences that necessitate student interactivity. The student is then periodically audit tested to ascertain mastery of the subject matter. The result of these mid-lesson evaluations serve as a self-check so that the student can assess his/her progress in the learning cycle. The systematic design of instruction and interactive approach to learning, enhances student motivation, improves learning and retention, while placing the responsibility of achieving specific ...


Semiconductor P-N Junction Space Charge Region Capacitance, Mohammad Humayun Habib Dec 1992

Semiconductor P-N Junction Space Charge Region Capacitance, Mohammad Humayun Habib

Dissertations and Theses

The classical capacitance voltage characteristics based on the depletion approximation, is adequate at reverse bias, but introduces errors at high forward bias. Because of its inherent simplicity and compactness this classical depletion model is well studied and widely used in circuit simulators. In this work, a new model for the semiconductor space charge region (SCR) capacitance, based on physical justification, will be derived. This new model takes three input parameters, C0 , Vbi and m, thus eliminating the fitting parameter FC currently used in SPICE. This new model is applicable for any applied voltage and will be compared with the SCR ...


Development And Analysis Of Non-Delay-Line Constant-Fraction Discriminator Timing Circuits, Including A Fully-Monolithic Cmos Implementation, David Martin Binkley Dec 1992

Development And Analysis Of Non-Delay-Line Constant-Fraction Discriminator Timing Circuits, Including A Fully-Monolithic Cmos Implementation, David Martin Binkley

Doctoral Dissertations

A constant-fraction discriminator (CFD) is a time pick-off circuit providing time derivation that is insensitive to input-signal amplitude and, in some cases, input-signal rise time. CFD time pick-off circuits are useful in Positron Emission Tomography (PET) systems where Bismuth Germanate (BGO)/photomultiplier scintillation detectors detect coincident, 511-keV annihilation gamma rays.

Time walk and noise-induced timing jitter in time pick-off circuits are discussed along with optimal and sub-optimal timing filters designed to minimize timing jitter. Additionally, the effects of scintillation-detector statistics on timing performance are discussed, and Monte Carlo analysis is developed to provide estimated timing and energy spectra for selected ...


Thermally Induced Vibration Of A Cross-Ply Laminated Plate With Hygrothermal Effects (Exact Solution), Stephen Jerry Maerz Dec 1992

Thermally Induced Vibration Of A Cross-Ply Laminated Plate With Hygrothermal Effects (Exact Solution), Stephen Jerry Maerz

Master's Theses - Daytona Beach

Of increasing importance in structural design is the use of fiber-reinforced polymeric composite material, notably in advanced aircraft and projectiles. These applications expose the materials to varied environmental conditions, therefore the material performance under these conditions is of great interest. One aspect of this is the solution of the dynamic response of a composite structure under elevated temperature and moisture conditions. An exact solution is formulated which describes the hygrothermal effects due to heating and moisture diffusion on one surface of a symmetric cross-ply plate made of AS/3501 graphite epoxy with simply-supported boundary conditions.


Isolating Failure Mechanisms In A Fiberglass/Epoxy Tensile Test Specimen Using Acoustic Emission Signal Parameters, Michael Kouvarakos Dec 1992

Isolating Failure Mechanisms In A Fiberglass/Epoxy Tensile Test Specimen Using Acoustic Emission Signal Parameters, Michael Kouvarakos

Master's Theses - Daytona Beach

This study used acoustic emission (AE) signal parameters to isolate the failure mechanisms in a 0° unidirectional, fiberglass/epoxy tensile test specimen. Since several failure mechanisms were known to be present, the lack of any distinctly identifiable bands in the original amplitude distribution indicated that there was considerable overlap between the AE signals of the various failure mechanisms. In order to separate the amplitude bands associated with each mechanism, it was necessary to sort on the duration of the AE signal. Two additional plots, counts versus amplitude and hits versus counts, were used to verify that the amplitude distributions were ...


Conceptual Design Of The Modular Transuranic Shipping Cask Mts-54, Vojislav Banjac Dec 1992

Conceptual Design Of The Modular Transuranic Shipping Cask Mts-54, Vojislav Banjac

Nuclear Engineering ETDs

The storage, transportation, and disposal of radioactive waste has become a problem of immense proportions in the United States. This Thesis focuses on the transportation of defense transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) repository near Carlsbad, New Mexico. The objective of the cask conceptual design was based on the following:

  • Taking into account the latest available data on TRU waste drum mass, investigate the possibility of increased drum capacity per shipment over the current design;
  • Present a new TRU cask design with increased drum capacity and the potential for transporting both Contact-handled (CH and Remote-handled (RH ...


An Integrated Simulation Model Development Environment For Slam Ii Using Object-Oriented Paradigm, Erol Dec 1992

An Integrated Simulation Model Development Environment For Slam Ii Using Object-Oriented Paradigm, Erol

Master's Theses

An integrated simulation model development environment was implemented to assist the modeler by automating certain activities of simulation modeling. The system included interactive model definition, experimental design, automatic simulation program generation in SLAM II. Object-oriented paradigm at software development stage was extensively used to conceptualize the structure, and rules of the SLAM II language in order to generate efficient, and modular program code. The present system targeted modeling of various probabilistic inventory control system problems. The remarkable advantages of the system were rapid model development time, and achieving reliable program code without requiring any knowledge in SLAM II. Object-oriented programming ...


Laser Doppler Velocimetry Research Of The Blowby Gas Characteristics In An Internal Combustion Engine, Coffill Dec 1992

Laser Doppler Velocimetry Research Of The Blowby Gas Characteristics In An Internal Combustion Engine, Coffill

Master's Theses

The project was designed to measure a reciprocating engine fluid flow (blowby gases past the piston rings) using a laser doppler velocimeter (LDV). Blowby gases were obtained by introducing compressed air into an engine cylinder (piston held at TDC) to simulate engine combustion pressures. Beginning the proposed research included starting an LDV/reciprocating engine laboratory at Western Michigan University and determining the limits of the measurement devices (LDV system in particular).

The limitations which were found in the LDV system only allowed for limited results of in cylinder optical measurements. The results obtained were for cylinder pressures below 0.6 ...


A Study Of The Effects Of Pigment Size And Shape On Binder Migration, Yang Dec 1992

A Study Of The Effects Of Pigment Size And Shape On Binder Migration, Yang

Master's Theses

The effects of pigment size and shape on coating structure and binder migration has been investigated. Clays and ground calcium carbonates of different particle size distributions were used in coatings with 15 pph SB latex.

Coatings were applied to Mylar and a special Tyvek using a wire wound rod. The coatings were dried slowly under ambient conditions, and using hot air immediately or after having been allowed to reach immobilization through penetration into the Tyvek. The dried coatings were evaluated for water holding, relative pore size and migration using the UV technique to measure the increase in SB latex at ...


A Study Of The Effects Of Polyacrylates On Water Retention And Binder Migration Tendencies Of Coatings, Charoenkitsupat Dec 1992

A Study Of The Effects Of Polyacrylates On Water Retention And Binder Migration Tendencies Of Coatings, Charoenkitsupat

Master's Theses

Five commercial polyacrylate samples were used to study their effects on viscosity, water holding, and binder migration under non-pressure conditions. The polyacrylates used were different in acid level, degree of crosslinking, and type of polymer (copolymer and terpolymer). A series of coatings was prepared using a number two clay and three styrene-butadiene latexes of similar particle size and T⋁g but different degrees of carboxylation, then the polyacrylates were added at several levels. The coatings were evaluated for rheological properties, water loss rate and binder migration. The results show that with increasing amounts of polyacrylates, the viscosity increased and the ...


A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Yiu Dec 1992

A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Yiu

Master's Theses

A probabilistic model was utilized to simulate the brown stock washing system's error due to process variability and measurement noise. Mass balances of the washing system were performed using distribution sampling. This model relies on a nonlinear relationship between displacement and dilution, which permitted the generation of displacement ratio based upon wash liquor ratio. Experimental trials were performed on a pilotscale rotary vacuum single-stage washer. Nonlinear first-order relationship appears to characterize a pilotscale washer adequately. Differences were observed between the means and standard deviations of the measured results compared to the simulation output. Future work is needed to identify ...


A Photometric Analysis Of Weapon Separation Characteristics, Douglas Paul Yurovich Dec 1992

A Photometric Analysis Of Weapon Separation Characteristics, Douglas Paul Yurovich

Masters Theses

This project attempted to implement a unique multi-camera photometric technology into the discipline of weapons separation testing from tactical jet aircraft.

This project was a U.S. Governmental, Department of Defense tasked affair, that utilized assets of the Naval Air Warfare Center Aircraft Division, Naval Air Station, Patuxent River, Maryland.

The methodology employed consisted of a standard lens calibration procedure; an airspace calibration procedure, that defined the zone for the activity of motion, and targeting of the aircraft and specific store.

With filmed flight test data in hand, the data was digitized through a motion sensor and stored as computer ...


Design For Productivity Using Gd&T, Srihari G. Acharya Oct 1992

Design For Productivity Using Gd&T, Srihari G. Acharya

Theses

No abstract provided.


A Study On Radical Scavenging And Magnetic Resonance Imaging Characteristics Of Stable Radical Nitroxides, Shiey-Shiun Horng Oct 1992

A Study On Radical Scavenging And Magnetic Resonance Imaging Characteristics Of Stable Radical Nitroxides, Shiey-Shiun Horng

Dissertations

Several nitroxides have been prepared for study of their image enhancement capability. These nitroxides contain different nitroxyl moieties within one molecule. On MRI examination for the nitroxides prepared, TEMPO and HPTPO are better due to their better water solubility, even though some of the others have more nitroxyl centers available. The intensity response is linear with respect to concentration in the range studied in most of the cases except for HPTPO, whose intensity finally reaches maximum when its concentration is higher than 10 mM.

Three sources of biomass, namely, liver microsomes, whole-cell yeast and a bacterial activated sludge consortium, have ...


Errors In Constant-Velocity Shaft Couplings, Philip M. Remington Oct 1992

Errors In Constant-Velocity Shaft Couplings, Philip M. Remington

Theses

A Multiloop spatial system of rotations is used to represent a shaft coupling, allowing a transmission plane which may deviate from the plane of symmetry to be specified. The plane of transmission, for intersecting input and output shaft axes, is the locus of intersections of screw axes that compose the system. By prescribing the transmission plane outside of the plane of symmetry (commonly called the "homokinetic plane" or "bisecting plane") to pecified orientations, a phase shift between the input and output shaft rotational displacements will he quantified. The rotational phase shift between the input and output shafts can be evaluated ...


Expert System For The Injection Molding Of Engineering Thermoplastics, Tzy-Cherng Jan Oct 1992

Expert System For The Injection Molding Of Engineering Thermoplastics, Tzy-Cherng Jan

Dissertations

Injection molding of engineering thermoplastics is the most widely used manufacturing method in industry. It is a priority to maintain a deviation-free operating environment to ensure high quality, low cost manufacture. An expert system for the injection molding of engineering thermoplastics has been investigated. The system can be used to attenuate the deviations experienced during the injection molding of engineering thermoplastics. The system is coded in C programming language.

The resolution procedures of this system include two stages such as the definition of declarative knowledge and the procedure of corrective actions. In the definition of declarative knowledge, all of the ...


Mathematical Model And Simulation Of The Progression Of Cutaneous T-Cell Lymphoma, Maria L. Agostinho Oct 1992

Mathematical Model And Simulation Of The Progression Of Cutaneous T-Cell Lymphoma, Maria L. Agostinho

Theses

A simple mathematical model and simulation of the progression of cancer with particular emphasis on Cutaneous T Cell Lymphoma was investigated. The mathematical model consists of a set of differential equations that first satisfies the homeostasis levels of the different components present and second predicts the dynamics during a diseased or unhealthy condition. The simulation was done using a FORTRAN program for integrating the differential equations.

Simulation of the immune system is important in evaluating the usefulness of particular sorts of biologically targeted therapies and in selecting the most promising treatment strategies for clinical trials. In particular, the effects of ...


Fabrication And Characterization Of Gated Silicon Field Emission Micro Triodes, Nanchou Liu Oct 1992

Fabrication And Characterization Of Gated Silicon Field Emission Micro Triodes, Nanchou Liu

Dissertations

This dissertation describes the fabrication technology and characterization of a gated silicon field emission micro triode that is a novel electron tunneling device for generating electron emission into a vacuum. Conic (point) and wedge field emitter structures with nm-scale radii were fabricated in silicon and GaAs by etching, MOCVD and dry oxidation. A new self-aligned process was developed for fabrication of vertical field emission triodes. This process allows control of gate opening to less than 0.5 μm diameter without the need of electron-beam writing. It also provides a planar gate electrode and a thick dielectric layer for reduction of ...


The Influence Of Pore Fluids On Shear Strength And Stress-Strain Behavior Of Granular Soils, Prasanna Ratnaweera Oct 1992

The Influence Of Pore Fluids On Shear Strength And Stress-Strain Behavior Of Granular Soils, Prasanna Ratnaweera

Dissertations

When a dry granular soil is subjected to an external load, the stresses are transferred through mineral to mineral contacts. The shear strength of such a soil is governed by its contact properties. Presence of a thin layer of fluid between mineral to mineral contacts in a saturated soil will alter its contact properties. Therefore any change in the physical properties of pore fluid can logically be reasoned to influence the deformation characteristics of granular soils.

To investigate the influence of pore fluid viscosity on shear strength and stress-strain behavior of a soil, a series of consolidated drained triaxial tests ...


Behavior Of High Strength Concrete And Slender Reinforced Concrete Columns With And Without Steel Fibers, Lin Showmay Hsu Oct 1992

Behavior Of High Strength Concrete And Slender Reinforced Concrete Columns With And Without Steel Fibers, Lin Showmay Hsu

Dissertations

A series of compression tests are conducted on 3 in. by 6 in. cylindrical specimens using a modified testing method that give the complete stress-strain behavior for both plain and fibrous high strength concretes with or without tie confinements. The volume fractions of fiber in the concrete are 0%, 0.5%, 0.75%, and 1.0%, respectively. Empirical equations are proposed herein to represent the complete stress-strain relationships of high strength and high strength fibrous concretes with compressive strength exceeding 10,000 psi. Various parameters are studied and their relationships are experimentally determined. The comparison between the experimental and analytical ...


Quantitative Assessment Of Myocardial Oxygen Supply And Demand Using A Dynamic Model Of The Cardiovascular System, Badrinath R. Puranic Oct 1992

Quantitative Assessment Of Myocardial Oxygen Supply And Demand Using A Dynamic Model Of The Cardiovascular System, Badrinath R. Puranic

Theses

A quantitative understanding of the changes in coronary, pulmonary and systemic hemodynamic variables and their effect on myocardial supply and demand is important to the better management of anesthetic care of patients with impaired cardiac function. Animal studies have identified those hemodynamic factors that play an important role in determining the balance between oxygen supply and demand for the myocardium. These include myocardial contractility, left ventricular end-diastolic volume, systemic arterial pressure, systemic vascular resistance, and heart rate. The interactions of these factors are complex and their combined effects on myocardial oxygen supply and demand are difficult to predict a priori ...


A Study Of Annular Slurry Jet For Abrasive Waterjet Cutting, Thomas Kuriakose Oct 1992

A Study Of Annular Slurry Jet For Abrasive Waterjet Cutting, Thomas Kuriakose

Theses

The objective of this project is to study the performance of an annualr slurry jet nozzle for abrasive waterjet cutting. This nozzle has been invented by Avraham. Harnoy, Department of Mechanical Engineering, NJIT and presented to the patent committee of NJIT in May 1990. This study includes design and development of prototyes and testing of their performance. Moreover, it includes initial theoretical study of the flow behavior. The idea is based on the merging of a high velocity pure waterjet with an annular jet of a slurry of water and abrasives at low velocity. The two jets merge outside the ...


The Use Of Laboratory Testing To Understand The Behavior Of Collapsible Soil Upon Wetting, Martha H. Denham Oct 1992

The Use Of Laboratory Testing To Understand The Behavior Of Collapsible Soil Upon Wetting, Martha H. Denham

Dissertations and Theses

In developing a constitutive model that could predict the settlement due to the collapse, several goals needed to be met. These were to gain an understanding of the collapse phenomenon, knowing the soil properties at the natural water content and how they change after collapse, and develop and test the new model. It was felt that laboratory testing could be of use. The types of test conducted included use of the Oedometer, Pressuremeter, and Triaxial tests. The material that was used for the testing was a "generic" soil manufactured out of diatomite. In all of the tests the soil was ...


The Effects Of Automation On Crew Coordination In The Corporate Cockpit, Yves P. Koning Sep 1992

The Effects Of Automation On Crew Coordination In The Corporate Cockpit, Yves P. Koning

Master's Theses - Daytona Beach

The implementation of automated systems in the cockpit has somewhat changed pilots' working environment. The present study, which focus is on corporate aviation, looks at the influence automation has on crew coordination.

A questionnaire including both Likert scale and open-ended questions was sent to 880 qualified pilots. A descriptive as well as an inferential analysis of the data provided by the Likert scale questions was conducted. Out of the five variables tested, the only one to generate any significant differences (p

Overall, pilots pointed out the importance of verbal communication and cockpit resource management training, emphasizing the strong need for ...


Minimization Of Exclusive Sum Of Products Expressions For Multiple-Valued Input Incompletely Specified Functions, Ning Song Aug 1992

Minimization Of Exclusive Sum Of Products Expressions For Multiple-Valued Input Incompletely Specified Functions, Ning Song

Dissertations and Theses

In recent years, there is an increased interest in the design of logic circuits which use EXOR gates. Particular interest is in the minimization of arbitrary Exclusive Sums Of Products (ESOPs). Functions realized by such circuits can have fewer gates, fewer connections, and take up less area in VLSI and especially, FPGA realizations. They are also easily testable. So far, the ESOPs are not as popular as their Sum of Products (SOP) counterparts. One of the main reasons it that the problem of the minimization of ESOP circuits was traditionally an extremely difficult one. Since exact solutions can be practically ...


Thermal Post-Buckling And Vibration Analysis Of Thermally Buckled Antisymmetrically Laminated Beams Using A 20 Dof Finite Element, Misao Mizuno Aug 1992

Thermal Post-Buckling And Vibration Analysis Of Thermally Buckled Antisymmetrically Laminated Beams Using A 20 Dof Finite Element, Misao Mizuno

Master's Theses - Daytona Beach

The purpose of this study is to use the finite element method to analyze thermal buckling, post-buckling, and vibrations of thermally buckled composite beams including shear deformation. The beam element used has ten degrees of freedom at each node: axial displacement, transverse displacement due to bending and shear, twisting angle, inplane shear rotation and their derivatives with respect to x. Hermitian polynomials and Lagrange's equation were used to derive the equations of motion. The equations of motion were divided into static and dynamic parts. For buckling analysis, the eigenvalue problem was solved for the critical temperature. The scaled first ...


Non-Linear Dynamics Of A Once-Through Steam Generator, Lamartine Nogueira Frutuoso Guimaraes Aug 1992

Non-Linear Dynamics Of A Once-Through Steam Generator, Lamartine Nogueira Frutuoso Guimaraes

Doctoral Dissertations

This dissertation presents a new analytical model for the Once-Through Steam Generator (OTSG) which is a component responsible for the primary coolant heat removal and the generation and supply of superheated steam to the turbine of the Pressurized Water Reactor (PWR) manufactured by Babcock & Wilcox (B&W) Co. This new analytical model provides the explanation of the oscillatory phenomenon observed in all PWRs manufactured by B&W that uses the OTSG as part of the steam supply system. It was found that the oscillatory behavior is related to the friction pressure drop caused by the reduction in flow area due ...


Design Of Nozzle Contours For The Pwt 16-Ft Transonic Wind Tunnel, William Everett Milam Aug 1992

Design Of Nozzle Contours For The Pwt 16-Ft Transonic Wind Tunnel, William Everett Milam

Masters Theses

The nozzle contours of the Tunnel 16T nozzle were designed in the early 1950's and, for the most part, were calculated by hand. In addition, corrections have been made to the contours through the use of an influence coefficient correction technique in an attempt to remove small flow irregularities. This correction technique is not based on aerodynamic theory, and, as a result the corrected contours are not necessarily aerodynamically correct. A second problem stems from the fact that the application of the nozzle corrections results in nozzle contours that do not change in a monotonic manner. There are some ...


Analysis Of A Hypothetical Criticality Accident Involving Damp Low-Enriched Uo2 Powder, Benan Basoglu Aug 1992

Analysis Of A Hypothetical Criticality Accident Involving Damp Low-Enriched Uo2 Powder, Benan Basoglu

Masters Theses

In this work, we report on the development of a computer model for predicting the excursion characteristics of a postulated criticality accident involving a homogeneous mixture of low-enriched UO2 powder and water contained in a cylindrical blender. The model uses point neutronics coupled with simple lumped-parameter thermal feedback. The reactivity feedback coefficients, reactivity driving force function, and the mean generation time are computed a priori using Criticality Safety Analysis Sequences No.1(CSASlX) and No.2(CSAS25) in the SCALE-IV system. The temperature of the system is calculated using a simple time-dependent energy balance where two extreme conditions for ...