Engineering Commons^™

Low Frequency Lumped Element Directional Couplers, Constantine Rodolph Jenkins

Masters Theses

"Lumped element directional couplers are desirable at frequencies below the VHF range because they eliminate the large physical size necessary for the distributed element directional couplers. The purpose of this work is to describe the theory and design of such low frequency lumped element directional couplers. A model for the coupler is developed and the equations which describe it are derived. Scattering matrices for one and two section couplers are obtained. Computer solutions for three section couplers are presented. Experimental results for one, two, and three section couplers are presented and comparison with theory are made. Comparisons of theoretical and …

Feed Drive Design For Numerically Controlled Machine Tools, Subash Bhatia

Masters Theses

"The various types of feed drive control systems used in numerical control of machine tools have been broadly classified. Further a step by step design has been presented for the feed drive of a numerical contouring control milling machine. The aim has been to develop a consistent strategy for tackling a variety of such problems. Consequently stress has been laid on principles and not on design figures"--Abstract, page ii.

Frequency Division Using Cascaded Phase-Locked Loops, Curtis B. Abshier

Masters Theses

"In many practical communication systems it is necessary to generate phase coherent subharmonics of an input tone. A useful system for accomplishing this task is a system of phase-locked loops in cascade. It is shown that when the feed-forward function is matched, the phase error of the second loop is zero. Analytical analysis and computer simulation prove that the minimum time to achieve phase-lock is obtained when the feed-forward function is matched. Under this condition, necessary design parameters are determined with ease"--Abstract, page i.

Design Of A Quadrature Envelope And Correlating Receiver, Clinton Harold Moor

Masters Theses

"A receiver design analysis and rationale is presented. The receiver is capable of performing in an instrumentation role for propagation experiments conducted in the field. The data gathered during the field tests will be used to determine the complex impulse response of the ground-to-ground communications channel and to evaluate the performance of a candidate ranging waveform in this channel. The receiver is capable of operation in either the propagation mode or the ranging mode and each mode of operation can be performed on either a UHF band frequency or an L-Band frequency. During the propagation mode the receiver serves as …

An Analysis Of Solar Noise Outbursts And Their Application To Space Communication, Marion Francis Moen

Masters Theses

"A relationship between sunspot activity, solar flare activity and noise outbursts is presented. Five different types of interference radiation in the 10MH_z to 30,000 MH_z frequency band are discussed. Data obtained by solar radio astronomy are analyzed to determine the extent of solar noise outbursts as a function of sunspot activity. An application of the burst data to future space communication is given"--Abstract, page ii.

Variable-Threshold-Mixed-Weight Threshold Element, Cheng-Chung Liu

Masters Theses

"A threshold element (TE) is a mathematical model of a class of logic gates. The desirability of a threshold element in the application of digital systems stems from its richness of logic power and its relative economy. On the other hand, the tighter tolerences required by the threshold logic element as compared to conventional logic gates have prevented them from being utilized extensively. The purpose of this thesis is to propose a versatile threshold element having high noise immunity and loose tolerance requirement. The proposed TE which has variable threshold and mixed weight capability uses current switching to enhance noise …

An Analog Computer Simulation Of The Flapping Of A Helicopter Hinged Main Rotor Blade, Edward Charles Robinson

Masters Theses

"An analog computer simulation was performed on the Systron Donner SD 40/80 electronic differential analyzer consisting of one panel (SD 40) less three modules augmented by three digital logic modules for iterative operation. The flapping equation was solved in continuous iteration for various values of blade mass and the resultant blade flapping magnitudes and harmonic coefficients were compared in computer plots of the blade tip path plane. A flap compensator was added and the result plotted. Various aerodynamic parameters of the flapping equation solution were plotted"--Abstract, page ii.

A Time And Frequency Domain Approach To The Optimization Of Linear Multivariable Regulators, Eugene Charles Machacek

Masters Theses

"Optimal design and analysis of a multivariable regulator may be achieved in either the frequency or time domain. This paper describes the formulation of the matrix Riccati equation in the time domain and the Wiener-Hopf equation and the root-square-locus in the frequency domain. The necessary requirements which must be satisfied in order to achieve an optimal control vector when using a quadratic performance index are presented for both domains. The resultant optimal control vector is shown to be a linear function of the system state vector. The effect of the quadratic performance index weighting matrices on the optimal system closed-loop …

Design Of A Semi-Automatic Transmission, Yogendra Prahladray Buch

Masters Theses

"Design of a semi-automatic four-speed transmission for automotive engines with moderate horsepower is described. The basic configuration consists of main and countershafts and five pairs of constant-mesh gears. Engine torque is transmitted through an input gear pair to the countershaft, and finally to the output shaft through a selected output gear pair. Selection is accomplished by engaging one of five hydraulically operated clutches located on the countershaft. Engagement fixes the desired gear to the countershaft and engine torque is then transmitted to the mating gear, which is fixed to the output shaft. Fourth speed is obtained by coupling the input …

The Effect Of Diameter On The Film Boiling Behavior Of Liquid Nitrogen, William Joseph Wafer

Masters Theses

"A film boiling heat transfer study was conducted for liquid nitrogen at atmospheric pressure. The heat transfer surfaces used were cylinders with outside diameters of 0.450, 0.650, 0.850, and 1.000 inches. The temperature differences covered were from approximately 150ºF to approximately 600ºF. The data indicate that the heat flux will decrease to a minimum then increase slightly as the diameter of the heat transfer element is increased at constant temperature difference. The heat transfer coefficient is expected to approach a flat plate correlation as the diameter approaches infinity"--Abstract, page ii.

A Closed Form Method For Predicting The History Of Circular Orbit Altitude Decay Of A Near-Earth Satellite Including The Effect Of A Dynamic Atmosphere, John Copley Buchholtz

Masters Theses

"A closed form expression for the time to decay between two circular orbit altitudes is developed. The long-term dynamic variation of high altitude atmospheric density is included. The density is approximated as a ratio of two quadratics with the numerator being a function of the time-related exospheric temperature and the denominator being a function of altitude. The 11-year cyclic variation of exospheric temperature is then represented as a piecewise linear function of time. The analytic expression for circular orbit altitude decay rate is developed by describing the energy loss due to atmospheric drag. A point mass representation of the Earth's …

A Laboratory Study Of The Transmission Of Signals Through Solid Material With Possible Application To Seismic Communication, Ronald Willis Carter

Masters Theses

"The problem of transmitting acoustic signals through solid material channels is investigated using piezoelectric transducers for generation and detection of the signals. Laboratory experiments are performed in which a solid material channel is modeled by a block of Berea sandstone. The magnitude of the frequency response for the sandstone and transducer combination is obtained over the frequency range of approximately 0 Hz to 500 kHz. Various electrical waveforms are utilized as driving sources for the transmitting transducer. It is found that the best received waveform is obtained when a gated sinewave whose frequency is approximately equal to the resonant frequency …

An Investigation Of Stress In The Monowall Construction System Subjected To Racking Loads, Louis Alex Kuhlmann

Masters Theses

"Several methods of analysis were employed to investigate the stress conditions of concrete block built in the MONOWALL Construction System, when subjected to racking loads. MONOWALL is a technique of assembling blocks with adhesive rather than conventional portland cement mortar. The analyses used in this study included strain gages on full-scale walls, photoelastic models, and a mathematical solution. Each method of analysis is reported separately in detail and the results compared to each other"--Abstract, page ii.

Perturbation And Sensitivity Analysis Of An Urban Model, Nicola Ann Nelson

Masters Theses

"This work describes a sensitivity analysis of the nine major system variables of the urban model postulated by Dr. Jay W. Forrester in his book Urban Dynamics. This model simulates the growth of a city from a nearly empty land area through a 250 year life cycle. Using small perturbations about the system trajectories, sensitivity matrices were computed at 135 years (growth period) and 240 years (equilibrium). The results show a matrix heavily weighted to give large sensitivity coefficients to the three housing variables, the PH sector being the most sensitive. Each of the housing sectors was analyzed further to …

Phase Equilibrium And Thermodynamic Study Of The Iron-Copper-Carbon System, Krishna Parameswaran

Masters Theses

"Gas carburization experiments were conducted at 950ºC in order to study the phase relations and to determine the activity of carbon in the iron-rich corner of the iron-copper-carbon system. The solubility of graphite in equilibrium with iron-copper alloys was determined at 950º, 1000º, and 1050ºC. The results of gas carburization and graphite solubility experiments at 950ºC were used in constructing an isothermal section of the iron-rich end of the iron-copper-carbon phase diagram, on which are superimposed carbon isoactivity lines. Graphite solubility data at 1000º and 1050ºC were used to construct similar diagrams without the isoactivity lines. The effect of carbon …

A Hybrid Computer Solution Of The Swing Equation, Donald Wayne Shaw

Masters Theses

"Models for the governor and exciter control systems are presented and the development of a hybrid computing system including these models is described. A technique for including the governor and exciter effects into the solution of the power system swing equation is also discussed. A hybrid computing system consisting of an SCC 650 digital computer, hybrid interface, and an EAI-TR-48 analog computer is used to study five test cases. The test cases involve basically the same example system with different values for fault clearing times and machine inertias. The results of each test case are briefly discussed with relevance to …

A Digital Computer Simulation Of A Rural Two-Lane Highway, D. Jay Frankenfield

Masters Theses

"The traffic flow model developed in this study is a digital computer simulation utilizing the technique of periodic scanning to move the vehicles through a series of unit blocks. The model simulates traffic flow on a rural two-lane highway by assuming a straight and level road and incorporating sight distance restrictions and no-passing zones to simulate the effect of limited sight distance. By utilizing various "passing rules" to initiate the passing maneuver, three general topics were investigated. This study investigated the use of 1000 ADT as a criterion for yellow line striping no-passing by using the computer simulation to determine …

The Concept And Design Of A Curvilinear Character Generator For Cathode Ray Tube Display Systems, Lawrence Edward Hanebrink Jr.

Masters Theses

"The character generator is the heart of any cathode ray tube display system. The types of generators in common use are the dot matrix generator, the raster scan generator, and the linear stroke generator. Each of these generators produces symbols whose legibility is somewhat compromised. A curvilinear generator is suggested which provides improved appearance and greater legibility. A prototype unit was constructed and the results are compared with the other generators. The curvilinear generator provides the best character resolution and readability of the generator types discussed"--Abstract, page ii.

Advanced Waste Treatment Of Industrial Waste Waters By Physicochemical Processes, Michael Gay Hardie

Masters Theses

"The primary objective of this investigation was to determine the general applicability of using physicochemical processes for treating different types of industrial wastes. Emphasis was placed on the evaluation of the treatment efficiency and the performance difficulties encountered in the treatment of each waste. Two types of waste were studied, one a high strength acidic industrial chemical waste and the other a petroleum refinery waste. The physicochemical system utilized included chemical coagulation and clarification plus activated carbon adsorption. Parallel operations of fixed-bed and expanded-bed carbon adsorbers were conducted. Treatment efficiencies were evaluated in terms of the removals of chemical oxygen …

A System Study Of A Computerized Grocery Store, Neal Joseph Martini

Masters Theses

"This thesis is a system study of a computer controlled grocery store. Previous work has been done in the area of computerized inventory control, and computerized checkout lines in grocery stores, but the system proposed in this thesis is to control the movement and handling of the products as orders are automatically filled. In the preliminary part of the system study, a comparison between a time shared computer service and a minicomputer is done, which results in the selection of a minicomputer for this control system. Then the general control system is presented, and the system interfacing and control for …

Compressibility Effects On Transient Gas Pipe Flow, Gerald Francis Mouser

Masters Theses

"Abstract (1) Methods of iterative solution for the partial-differential equations that govern the transient flow of gases in pipelines are obtained by using the method of characteristics and linear finite-difference techniques. Solutions are developed for 1) a constant gas compressibility factor throughout transient conditions, and 2) a variable gas compressibility factor at constant temperature dependent upon pressures encountered during transient flow. Theoretical studies are made to compare results using both approaches for pipelines operating at various constant flowing temperatures. Results show greater differences between the two methods at lower values of flowing temperature due to the more rapidly changing compressibility …

Laser Interferometric Holography Investigation Of Free Convection About A Vertical Plate Of Non-Uniform Temperature, Richard Kenneth Thomson

Masters Theses

"An experimental investigation was conducted using a holographic interferometer to detect the temperature variation in a free convection boundary layer about a vertical heated plate. The heated plate was non-isothermal and investigations were conducted for four temperature distributions; the maximum plate temperature ranged from 200F to 493F. Photographs were taken of the fringe patterns and boundary layer thickness measurements, as well as temperature measurements, were made. A theoretical model was constructed by applying the integral method to the energy and momentum equations. The experimental values agree quite well with this model. The advantages of the holographic interferometer over other systems …

An Empirical Method Of Correlating Compressibility Factors Of Nitrogen - Helium - Hydrocarbon Systems, Terry Wayne Buck

Masters Theses

"Compressibility factors have been taken from previous works by Davis and Taneja for twelve different common oil-field hydrocarbon mixtures which contain at least 2 mole % nitrogen. An effort has been made to show that by using the Benedict-Webb-Rubin Equation of State it is possible to predict compressibility factors using a correlation of error in predicted compressibility factor versus reduced pressure, at different mole % of nitrogen with constant reduced temperatures, if the critical points of the mixtures are known or can be calculated. In the mixtures which contain helium, the only effect of helium seems to be the raising …

The Skid Resistance Of Asphaltic Pavements Using Glass Aggregates, Michael Vaughn Korth

Masters Theses

"The disposal of the glass portion of solid waste is an ever-growing problem in the U.S. and recycling has been suggested as a possible solution. In order to find new uses for waste glass, investigations have been conducted to determine if the glass could be used as an aggregate in bituminous concrete mixtures. As part of the overall investigation, this study was concerned with investigating the skid resistance properties of the glass aggregate mixtures, called glasphalt. The objectives were to compare the skid resistance of various bituminous mixtures using aggregate combinations ranging from all glass to all conventional aggregate and …

An Investigation Of A Bistable Oscillator Used In A Phase Modulated Control Circuit, Yu-Fang Yen

Masters Theses

"A primary component in the investigation of phase modulated control systems is bistable oscillator which converts a constant oscillation signal to control the system. The oscillator is feedback type that utilizes a feedback capacitance and resistance in each feedback path to change its frequency. The theoretical behavior of bistable oscillator was investigated and the non-dimensional results were set for convenience in determining the oscillation period. The control circuit which based on the oscillator was also presented a form of suitable circuit for direct application to practical control problems"--Abstract, page ii.

Development Of An Elastic-Plastic Finite Element Program With The Initial Strain Approach, Vernon Dale Allen

Masters Theses

"A finite element method is presented for solution of plane stress and axisymmetric elastic-plastic problems employing the method of successive elastic solutions with the initial strain approach. The problem of nonconvergence of the initial strain approach for perfectly plastic problems was eliminated by expressing the Prandtl-Ruess equations entirely in terms of strain. Two examples are presented to demonstrate the validity of the method"--Abstract, page ii.

Analysis Of Factors Affecting Station Capacitor Bank Switching Transients, M. Davarpanah

Masters Theses

"The problem presented here is a study using a computer program which predicts the transient response when energizing a station capacitor bank of a power system. The computer program gives the wave shape and magnitudes of switching surges obtained while energized capacitor banks at one location and showing the effect of switching a bank while adjacent banks are already energized. The over voltages are given in line-to-ground voltages on the line side of the capacitor banks as well as at lower voltage levels down to the customer 120 volts service voltages. The purposes are to obtain the optimum values of …

High Temperature Compressive Creep In Mullite, Peter C. Smith

Masters Theses

"Compressive creep measurements were made on two groups of mullites at temperatures between 1455ºC and 1520ºC. The first group consisted of commercially manufactured mullites. The second group was made up of 7 different mullite compositions spanning the alumina-silica solid solution range from 3Al₂O₃ • 2SiO₂ to 2Al₂O₃ • SiO₂ . Thermal activation energies and stress exponents were calculated for the mullites in the second group. Steady state strain rates taken at 1460ºC under loads of 100 and 110 psi varied between 1.3x10⁻⁴ in/in/hr and 15.4x10⁻⁴ in/in/hr. Activation energies were between 109 Kcal/mole and 204 Kcal/mole. Stress exponents calculated from data …

The Use Of Semiconductor Memories In Drug Dispensing, James John De Largy

Masters Theses

"This paper presents the problems encountered and the methods used during the design of an electronic system to be an integral part of a medical drug dispensing machine. The system has a memory composed of both random access and read only memories to enable it to operate, along with many such machines , from one data input line. The system accepts information such as patient's name, social security number, and drug location number. It also provides signal drive to an attached printer in order to reproduce this information for use on the drug label. Finally, the system electronics accepts input …

A Software System For Interactive Man-Machine Design And Analysis Of Electronic Circuits, Leo William Midden

Masters Theses

"The development of an interactive computer-aided circuit analysis program is presented. A graphics terminal is used as an I/O device while an SCC 650 mini-computer is used as peripheral processor. The central processor is an IBM 360/50.

Formulation, capabilities and use of the system are discussed in detail. Close attention is given to user control, making the system both useful and versatile. Both hard and soft copies of all plots and tabular data are available. Provisions are made for error corrections and changes at each step of the input. Parameter values can be altered before and after each analysis.

Additionally, …