Engineering Commons^™

Performance Comparison Of Receivers Designed To Combat Intersymbol Interference Due To Specular Multipath, George H. Smith

Masters Theses

"Bit error probabilities for biphase transmission have been computed for a known two-component multipath channel with a variety of suboptimum receivers. Performance curves are presented for each receiver, and the relative performance is summarized. Degradation due to imperfect channel knowledge is calculated, and the feasibility of countering this interference with these specially designed receivers is discussed"--Abstract, page ii.

Analysis And Measurement Of A Zener Diode Voltage-Reference, Armond C. Maxeiner

Masters Theses

"Output voltage sensitivity equations are derived for a zener voltage-reference circuit. The circuit consists of a DC-DC converter, a voltage-resistor current generator, and a zener diode. The performance of the voltage-reference is calculated using the sensitivity equations and compared to measurement data taken from a laboratory model of the circuit. The results are in reasonable agreement.

It was concluded that with careful selection of components, two of three major sources of error can be predicted and controlled; these are changes due to input voltage and changes due to temperature. The third, changes due to time, requires calibration against a voltage …

Design Of A Digital Control Unit For A Seismic Digital Tape System, Cao-Van Chung

Masters Theses

"This paper describes the interface between the NOVA digital computer and the Texas Instrument tape unit which handles field data recorded simultaneously from a maximum of 31 channels. The interface is the means through which the NOVA computer can control the tape unit and recover data. To provide necessary background information a review of the characteristics of the tape unit and the input-output operation of the NOVA computer are given. As the first part of the design, the general interface design is presented and the functions of its units are described. After discussion of functional assignment of each unit, coordination …

A Study And Design Of A Cardiac Interbeat Interval Timer System, Richard William Mooney

Masters Theses

"This thesis reports the design of a system which can measure and record the cardiac interbeat times of human subjects in a continuous beat to beat manner, using the bioelectrical signal associated with the heart as an input. The design is in response to the needs of clinical researchers.

The means of obtaining the bioelectrical signal and previous designs of electrocardiographic equipment, especially electrocardiotachometers, are reviewed. A design is proposed which consists of a preamplifier to amplify the bioelectrical signal, a 60 Hz rejection filter, and a beat detector which uses a differentiation technique to obtain a reliable single output …

An Experimental Study Of Power Systems, Nguyen Quang Duoc

Masters Theses

"For three phase AC power systems consisting of synchronous machines interconnected by transmission lines and other electrical transmission equipment, the power transmitted and the stability of the system depend upon the constants of synchronous machine and the characteristics of the transmission lines. The purpose of this work is to design and set up a model of a power system in the laboratory, measure the constants of synchronous machines, the power angles and power flows of the system. An investigation of the effects of the saturated machines is based upon the laboratory data.

This work is intended primarily as a tool …

A Study Of Plane Wave Filter Analysis With Flow, Thomas Valle Huber

Masters Theses

"The purpose of this investigation is to determine the effect of slow steady flow on the reflection and transmission characteristics of acoustic filters.

A standing wave tube and transmission tube apparatus, designed and built by a previous investigator, was modified to accept slow steady flow. Reflection characteristics were determined from measurements made on the inlet side of the filters investigated. These data along with measurements taken with the transmission tube apparatus were used to determine transmission characteristics. The calculations were simplified by terminating the filters anechoically. The filters used in this investigation were an expansion chamber, an automobile type muffler …

A Sensitive Temperature Measuring System, Larry Dean Morris

Masters Theses

"A sensitive temperature measuring system, providing an analog output proportional to sensor temperature, has been designed for use in the wall temperature control system of a cloud simulation chamber. A platinum resistance element is the sensor, and a precision wirewound resistor is the reference in a bridge circuit which uses four low cost operational amplifiers arranged to provide two precision 1000 Hz current sources. Problems with an initial bridge amplifier design were corrected in the final design by the use of a low Q bandpass amplifier for the bridge signal followed by a phase detector and an output low pass …

High Speed Magnetically Supported Vehicles For Reducing Transportation's Degradations Of The Environment, Pravinchandra Shukla

Masters Theses

"The development of new techniques for higher speed transportation is desirable to satisfy the environmental, conservation, and economic requirements of society. Some of the important factors are presented for developing magnetically supported vehicles. A new method for improving the ratio of lift force to drag force is suggested and discussed. An application of the new technique to vehicles that would ride on a carpet of magnetism and would operate with less waste of energy is suggested "--Abstract, page ii.

Digital Registration Of Stereo Images Using The Fast Fourier Transform, Victor Francis Wilreker Jr.

Masters Theses

"The exact alignment of multispectral imagery is a requirement of any image classification system. This investigation develops a system of programs which result in a technique that corrects for the translational and rotational misalignment of two images. Rotational and translational components are determined by using the fast Fourier transform to find the points of maximum correlation between the two images. The registration of two equal but misaligned boxes is given as an example of how the transform technique is used in correlating the images. The results of registering two digitized images that were obtained by scanning a pair of color …

The Morphology Of The Cellular Precipitation Reaction In A Pb-3.0 Wt% Sn Alloy, Federico Sequeda Osorio

Masters Theses

"The complete development of the cellular precipitation structure at selected grain boundaries in a Pb-3.0 wt% Sn alloy during aging at 34°C and 23°C was investigated by light microscopy. The cellular structure in this alloy consists of lamellae of solute depleted lead solid solution and lamellae of ß tin precipitate. The cellular precipitation reaction begins by local migration of a grain boundary with concomitant grain boundary precipitation of ß tin. The grain boundary bows around the ß tin grain boundary precipitates which then begin to lengthen in the direction of boundary migration thus forming the precipitate lamellae of the cell. …

Computer-Aided Circuit Optimization Including The Adjoint Method Of Calculating Network Sensitivities, John Walter Olson

Masters Theses

"A complete discuss ion of the optimization of a circuit, including modeling and programming difficulties encountered, is presented. A three transistor bandpass filter is used in order to study various methods of optimization. The adjoint method of calculating the network error gradient vector is compared to the perturbation method. The adjoint method proves to have decided advantages over the other method. A generalized computer program is presented to carry out the Fletcher-Powell optimization algorithm with specialized subroutines which include a network equation solver and both methods of finding the gradient vector. The program proved very effective in realizing a desired …

Polynary Silicon Tellurium Glasses, Henry Edward Anthonis

Masters Theses

"The introduction of Ag into Si-As-Te glasses permits the incorporation of Se, otherwise volatile and/or degradable as a constituent in Si-containing chalcogenide glasses. Si-As-Ag-Te-Se glasses exhibit much higher softening ranges and glass transition temperatures than encountered in known chalcogenide systems. A glass Si₃₅As₁₅Ag₁₀Te₂₀Se₂₀ had the viscosity log η =13 at about 500°C, as compared to 370°C for the base glass Si₃₅As₂₅Te₄₀, the viscosity of log η = 9.8 at about 560°C, as compared to 442°C for the base glass Si₃₅As₂₅Te_{40 …}

Design And Construction Of A Drop Generator For Use In A Vertical Wind Tunnel, Danny Ray Conner

Masters Theses

"A drop generator, based on the principle of a vibrating capillary, was designed and built for use in the UMR vertical atmosphere wind tunnel. The drop generator worked very well on a test stand where it was firmly supported, but was not consistent when tested in the wind tunnel. Vibration of the wind tunnel walls and a slight turbulence near the forward edge of the generator caused an oscillation in the position of the stream of drops. The oscillation resulted in some of the drops hitting the edge of the collector cup, where the drops would accumulate until a large …

Computer Simulation Of The Primary Recoil Spectra And Damage Cross Section Of Fe₃Al Using Endf/B Ii Data, Daniel Willard Smith

Masters Theses

"A computer program, using Evaluated Nuclear Data File (ENDF/B II) information, was used to develop energy-exchange kernels which delineate the energy transfer probabilities between neutrons and Fe₃Al lattice atoms. The kernels combine all available information on elastic and inelastic scattering contained in the ENDF/B II data.

The computer program used to generate the primary recoil spectra is SAKI, a modified version of RICE (1). SAKI is designed to calculate energy-exchange probabilities in any binary alloy as well as damage cross sections and optimum cutoff energies for use in comparing displacement effects in different reactor spectra."--Abstract, page ii.

Laboratory Studies Using Diffused Oxygen And Air For Hypolimnion Reaeration, Chin-Ming Pai

Masters Theses

"The purposes of this research were to study the oxygen transfer rates and the oxygen transfer efficiencies of different types of aerators using different sources of oxygen in different types of water bodies, and to evaluate the number of diffusers required to be installed in a selected lake for hypolimnion aeration.

The experiments were conducted using a specially designed column. Four types of aerators, including a cylindrical stone diffuser, a spherical stone diffuser, and 2 ceramic diffusers (types A and B) which differed in pore size, were utilized as the aerators. The water bodies selected for the studies were Rolla …

A Study Of The Effect Of Drilled Holes On The Concentration Of Elastic Stresses Around A Notch, Glenn Michael Kmecz

Masters Theses

"Hole drilling as a method for improving the toughness of notch weakened tensile specimens is investigated by means of a photoelastic technique. Tests were performed on 20%, 40%, 60%, and 80% notch depth specimens machined from PSM-1 photoelastic material. The basic criteria for success was no increase in the elastic stress concentration factor. The photoelastic results were verified by a finite element stress analysis of the 60% notch depth specimens. Comparison of the experimental and numerical results provide conclusive proof that no increase in the elastic stress concentration factor occurs when proper positioning of the drilled holes is accomplished"--Abstract, page …

Fitting Discrete Probabilistic Frequency Distributions To Disturbed Traffic Flow At An Unsignalized Urban Intersection, Horst Walter Kaminsky

Masters Theses

"Traffic variables, such as volume, speed, gaps and lags, and headways can be described by probability distributions. In this study vehicle arrivals from three directions have been recorded at a four-leg, right-angled, at-grade intersection in Rolla, Missouri, and statistically analyzed. Two distinct probabilistic statistical concepts were used, the continuous (gap) and discrete (counting) distribution. The negative exponential distribution is discussed briefly, whereas the applicability of discrete statistical models for the traffic situation selected is elaborated in detail.

The purpose of this research was to investigate the impairment and distortion that various interferences such as upstream traffic lights, bottlenecks or other …

Drag Reduction On Non-Ionic Surfactants In Aqueous Systems, Jen-Lin Chang

Masters Theses

"The use of polyoxyethylene alcohol non-ionic surfactants as drag reducing additives in aqueous systems was investigated. Significant drag reduction was obtained with suitable combinations of one percent Alfonic 1214 and salts at 30°C such that the surfactant was near or above its upper critical solubility temperature. Maximum drag reduction was observed at the cloud point. Relative viscosity values also peaked at this point. No upper critical shear stress was attained up to wall shear stresses of 2,000 dynes/cm² with one percent Alfonic 1214 solutions at their cloud points.

At a fixed temperature, the salt concentration required to reach the …

Effect Of Glass Aggregates Upon Abrasiveness Of Asphaltic Mixtures, Dwarka Prasad Gupta

Masters Theses

"The utilization of glass as an aggregate in asphaltic concrete pavements has been suggested as a means for reusing the increasing amounts of waste glass generated each year in the United States. Recent studies have shown that asphaltic mixtures containing glass aggregates can be designed to meet Marshall requirements for stability, flow and void content but the abrasiveness of mixtures containing glass aggregates had not been investigated. The objectives of this study were to develop a laboratory wear testing apparatus and compare the abrasiveness of asphaltic concrete mixtures using glass aggregates with the abrasiveness of mixtures using several different conventional …

A Study Of Fmfb Demodulator Operation In The Presence Of Radio Frequency Interference And Gaussian Noise, Terry D. Wormington

Masters Theses

"A digital computer model of an FMFB demodulator has been used to study the effects of radio frequency interference on the detection of a sinusoidally modulated carrier. The effectiveness of selecting the feedback factor to suppress the interference for three values of modulation index is investigated. Also, the required IF bandwidth for the minimization of the mean-square error of the loop output between a signal corrupted by interference and the same signal without interference was investigated. More work is required before the effects of Gaussian noise plus interference on loop operation can be ascertained"--Abstract, page ii.

A Study Of Right Turn On Red At Signalized Intersections, Ronald Duane Rains

Masters Theses

"Traffic engineers have discussed the controversial subject of allowing drivers to make a right-turn-on-red (R.T.O.R.) for many years. There have been many strong points given for and against allowing this movement.

Within this paper R.T.O.R. is discussed and conclusions are drawn for a research of literature and questionnaire survey.

Questionnaires were sent to ninety-three cities and all fifty states. Many valuable unwritten facts and opinions were received from the seventy city and thirty-six state traffic engineers that completed and returned the questionnaires.

It was determined that 63.8% of the states replying and 64.3% of the cities are presently utilizing R.T.O.R. …

Data Compression Design Considerations For Airborne Test Vehicles, Kenneth Carlyle Pittman

Masters Theses

"The design goals for a data compression system are developed using previous studies as a cornerstone. Sampling theory is touched on with qualitative coverage of its effects. Consideration is given to various methods of data compression with the advantages and disadvantages of each noted. The requirement for buffering is discussed along with various methods that may be employed to achieve specific buffering goals. The impact of data reconstruction and how it may affect the choice of compression techniques is briefly covered. Selected compression algorithms and ways of increasing system effectiveness through alterations to their basic structures are described in detail. …

Sensitivity Analysis In Active Rc Bandpass Circuits, Robert Bentzinger

Masters Theses

"This thesis is concerned with the analysis and cataloguing of sensitivity functions of some selected active RC bandpass networks. The sensitivity functions of primary interest are the sensitivities of the quantities ω_o and Q with respect to changes in the element values of each circuit.

An introduction is provided to give background information on how each circuit is realized. Each circuit is then analyzed and the pertinent sensitivity functions catalogued. Some comments are made as to the approximations which are involved in several of the realizations and the validity of any sensitivity analysis made on these approximate realizations. The …

Shear Properties Of An Organic Soil And The Same Soil With The Organic Matter Removed, David Eugene Daniels

Masters Theses

"The effect of strain rate on the shearing properties of an organic A̲ horizon Bryce clay and the same soil treated with hydrogen peroxide to remove the organic matter was studied. For both soils, the pore pressures were found to be independent of strain rate, and dependent only on the increment of strain during shear. The effect of the hydrogen peroxide treatment on the shear properties of an inorganic Bryce B̲ horizon clay was also studied. It was concluded that the hydrogen peroxide does not affect the mineral properties of the Bryce clay and serves only to selectively remove organic …

Laminar Heat Transfer For Small Prandtl Number Fluids Including Step Change In Wall Temperature, Shiny Ting

Masters Theses

"The object of this investigation is to provide a simple means of determining the heat transfer from a flat plate which has an unheated leading length x₀. The case of steady, two-dimensional, laminar flow of an incompressible fluid with a Prandtl number of less than one is considered. Since there exists an unheated length and the Prandtl number of the fluid is less than one, the thermal boundary layer intersects the flow boundary layer. Thus, the solution of the problem divides into two regions. In this study, the problem is solved analytically by employing the energy integral equation. The temperature …

Free Vibrations Of Circular Cylindrical Shells, Sushil Kumar Sharma

Masters Theses

"In this report bending theory of shells is used to determine the natural frequencies and mode shapes of circular cylindrical shells. The governing eighth-order system of differential equations has been put in a form which is especially suitable for numerical integration and application of different sets of homogeneous boundary conditions. The Holzer method is used to solve the eigenvalue problem. During numerical integration of the differential equations, the exponentially growing solutions are suppressed whenever they become larger than previously selected values. Numerical results are obtained for various shell geometry parameters and for three different sets of homogeneous boundary conditions. These …

Contractor Quality Control: A Method Of Construction Inspection, John Scott Treadwell

Masters Theses

"It has become apparent in recent years that the United States Government's construction contract supervision and administration procedures are causing an increase in contractor claims and disputes and that the system itself is becoming prohibitively expensive. To deal with some of these problems, the Department of Defense is attempting to implement a new approach to construction inspection--Contractor Quality control. Under the Contractor Quality Control System the majority of the standard contract inspection and testing responsibilities are placed on the contractor, and the Government relinquishes its traditional step-by-step inspection and testing procedures and withdraws to a position of contract surveillance. The …

The Effect Of Cathodic Protection On The Stress Corrosion Characteristics Of 300m Low Alloy Steel, John Pechonick

Masters Theses

"The objective of this investigation was to determine if stress corrosion failure of 300M steel is accelerated by the application of cathodic protection. Testing was conducted on notch tensile specimens that were coated with vacuum cadmium, electroplated cadmium, and vacuum aluminum. All specimens were stressed and placed in an aqueous sodium chloride environment. The failure times for the specimens were monitored and graphs were drawn which characterized the stress corrosion resistance of 300M steel and the cathodic protection systems. Fractography techniques were used to study the failure surfaces to determine the type of failure mechanism. The results of this thesis …

Shop Level Maintenance Of Inertial Platforms Without A Surveyed Site, Max E. Bott

Masters Theses

"The initial installation of a rotary tilt table for an aircraft inertial navigation system test facility includes accurately aligning the rotary tilt table to local level and true north coordinates. The survey techniques presently employed are an encumbrance during installation and complicate remote deployment. The objective of this thesis is to determine if an inertial platform or platforms can practically be used to replace the role of the survey techniques in the rotary tilt table alignment. The construction, capability and operation of a rotary tilt table are reviewed. The tests necessary to test and calibrate an inertial platform are outlined, …

Interactions Between Selected Pigment Producing Bacteria Isolated From Sewage, Leslie Alexander Lakie

Masters Theses

"Pigmented bacteria have been of interest to the microbiologist for several years. The pigmented organisms in sewage have been known to gain predominance, but no investigations have been made to determine whether the pigment assists the organism in gaining predominance. During this study a number of bacteria which produced a water soluble pigment were isolated from sewage. These bacteria were grown in shaken flasks using tryptone Glucose extract broth as a medium. Growth studies of the bacteria in pure and mixed culture were performed to determine if the pigment could affect another bacteria's growth. Studies were also performed using the …