Digital Commons Network^™

Computerized Registration For High Schools, Kenneth Lee Fore

Masters Theses

"The guidance personnel in a high school are often burdened with the duty of hand scheduling the student's courses. Using the computer as a sub-optimizing tool in the registration of students, however, can cut scheduling time dramatically and relieve the guidance department of an onerous chore. The technique described in this investigation uses a conflict matrix that schedules the student's request and keeps the class load level within the course sections. A search of the schedule array for each course request may uncover a conflict. If no conflict occurs the course is scheduled and the remaining courses for this student …

High Pressure Water Jet Cutting Of Rock, Richard Lee Henry

Masters Theses

"Three experiments are described that investigate the impingement of high pressure water jets on rock. The effect of jet pressure, stand-off distance, and time of impact on penetration and specific energy of rock removal are determined on Berea sandstone, Georgia marble, and Missouri granite. Pressures range from 5,000 psi to 25,000 psi, stand-off distances from 2.0 inches to 4.0 inches and time from 0.1 seconds to 5.0 seconds. The nozzle diameter used was 0.023 inches. The effect of nozzle speed and number of passes over the same area on depth of cut and specific energy are investigated on the above …

Preliminary Studies With A Variable Transfer Composite Polymer Membrane., Samuel Walter Dortch

Masters Theses

"A preliminary study was done to determine the feasibility of using a compressed fibrous teflon (PTFE) silicone polymer membrane in extracorporeal oxygenation devices. A series of composite membranes were fabricated, using different concentrations of a dimethyl silicone polymer dissolved in petroleum ether, to give membranes having variable oxygen transfer properties. A gas-gas system was chosen to obtain the necessary transfer data. Data were obtained by transferring pure oxygen through the membranes into a mixture of 47 mole percent oxygen and 53 mole percent carbon dioxide. All analyses were obtained by chromatographic techniques. The results of these experiments show that membranes …

Force Analysis Of Involute Spur Gears, Janakkumar Girjashanker Dave

Masters Theses

"This study is devoted to the fundamental action which occurs between spur gears with involute tooth profiles when power is transmitted at a constant angular velocity ratio. Various aspects of the interaction between two mating teeth are considered. Analytic expressions for the variation of the force transmitted between two teeth are derived. Two cases are considered which include and exclude the effects of sliding friction between the teeth. The parametric equations of the involute curves for two mating teeth are derived in terms of body-fixed coordinates. Analytical expressions for Hertz compressive stresses in the teeth were also obtained. The same …

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 …

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 …

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 …

Mechanism Of Ual₃ To Ual₄ Transformation, Ling Ping Lee

Masters Theses

"The UAl₄ compound which forms during the peritectic reaction, Liquid + UAl₃ - UAl₄ , has a long needle-like shape and a characteristic morphology of fish-tail when cut along the long axis. It has an internal core of another phase when cut perpendicular to the needle axis. Because of the interesting similarity between UAl₃ and UAl₄ crystal structures, the peculiar UAl₄ morphology could be explained. The mechanism of UAl₃ to UAl₄ transformation is identified as shear and diffusion controlled transformation"--Abstract, page ii.

Use Of Isotopes To Reduce Neutron-Induced Radioactivity And Augment Thermal Quality Of The Environment Of An Underground Nuclear Explosion, Nathaniel Fred Colby

Masters Theses

"The use of isotopes to include radioactive waste products to reduce the neutron-induced activity of an underground nuclear explosion and its application in the field of geothermal power stimulation is discussed. A shield composed of selected isotopes surrounding a fusion device will capture excess neutrons producing isotopes with short half-lives. Subsequent rapid decay will prolong the high temperature in the vicinity of the explosion and decrease the activity. Long-lived isotopes created by neutron capture in the host rock would be minimized. The investigation is conducted for strontium-90, cesium-137, cerium-144, technetium-99, rhodium-103 and -105. Of these, the first three appear to …

An Analysis Of Single Wire Earth Return (Swer) System For Rural Electrification, Balwinder Singh Samra

Masters Theses

"The primary objective of this investigation was to determine the general applicability of Single Phase Earth Return(SWER) system for rural electrification where the load density is low, for example electrification of farms and small villages in emerging nations. The limitations of SWER system of distribution are many and it is necessary to make judicious use of such transmission. In this investigation the construction costs of transmission and distribution by SWER system is compared with single phase and three phase systems for loads of 25KVA and 50KVA. Phase converters are required to operate a three phase motor on a single phase …

Design And Test An Operational Amplifier Speed Transducer, Tung-Ming Huang

Masters Theses

"This thesis describes the design of an angular speed transducer. The purpose of this device is to provide a D.C. voltage which is proportional to the angular speed of a rotating shaft at any instant. The speed of the shaft is defined from a magnetic pickup monitoring a gear or similar device attached to the end of the shaft of a piece of rotating equipment. The signal from the magnetic pickup is modified and compared to a frequency generated in the feedback loop of the speed transducer and the error is sent to an integral type controller. The output of …

Analysis Of A Substitute For The Impact Damper To Damp Near-Resonant Mechanical Vibrations, Nguyen Khanh Van

Masters Theses

"This report investigates a substitute for the impact damper which, although highly effective in reducing vibration amplitudes of near-resonant mechanical systems, in operation causes often unacceptable intensive noise. The present damper consists of a piston free to move in a cylinder, at either end of which is a ball valve set to open at a preset pressure, and in the middle along its length an intake port. An approximate analytical study is made to determine the conditions for the existence of "noiseless periodic operation" of the damper, periodic operation without the occurence of impacts. This approach is based on the …

Structural Test And Analysis Of A Vierendeel Steel And Concrete Composite Girder, Melvin Crews Oestreich

Masters Theses

"The results of the structural load testing of a unique type of steel and concrete composite girder are described. The structural system, referred to as a composite Vierendeel girder, is a hybrid type which incorporates features of a castellated beam and a Vierendeel truss. The performance of the composite girder agreed reasonably well with calculated values based on section properties for a prismatic beam. Observations indicated web stiffeners were required on the stub beams to prevent premature failure of the system. Failure of the girder was due to concrete crushing over a stub web beam. Design considerations for a structural …

Development Of A Sampling System And Characterization Of Stormwater Runoff From A Small Urban Area, William Clark Ford

Masters Theses

"Increasing urbanization and the demand for high quality water have directed attention to the problem of combined sewer overflows, while recent research has demonstrated that stormwater alone, without the influence of sanitary sewage, carries a significant pollutional load. The purpose of this investigation was to determine the quality and pollutional contribution of stormwater runoff from a small urban area, with specific emphasis on the development of a suitable sampling and flow recording system, the characterization of runoff and the correlation of runoff quality with local environmental factors and storm characteristics. The system developed consisted of an automatic sampler capable of …

Managerial Appraisals - A Systems View, James Thomas Hatlan

Masters Theses

"In the past decade much has been written concerning the performance appraisal which can be defined as the systematic analysis of the individual with respect to his performance on the job. The appraisal's importance lies in the fact that its impact is felt in the areas of control, promotion, and managerial development all of which are essential for the progressive firm. This study is an attempt to offer something new and something different. The author offers a systematic study of industry in general with specific help from key corporations and utilities. His investigations encompass the three elements of appraising and …

Experimental Study Of Neutron Reflection From A Cylindrical Surface, Dale Lee Holtzscher

Masters Theses

"The reflection patterns for an elliptical neutron beam impinging upon cylindrical and planar surfaces were measured. The flux intensity as a function of distance from the surface of either planar or cylindrical reflectors decreased monotonously with distance. No "focusing" of the neutron beam appeared in the case of the cylindrical reflectors but the flux did not decrease as rapidly as in the planar case. For the elliptical neutron beam the experimentally determined neutron flux distribution agrees with calculation"--Abstract, page ii.

Decimal-Base Binary Logic (Dbbl) Adders And Registers, James Oliver Bondi

Masters Theses

"This paper discusses a new type of base n adder and storage register. This new type of logic is called "n-base binary logic", or NBBL. The NBBL system is compared and contrasted with the Post base n system (a type of n-valued logic), the binary-coded base n system, and the straight binary system. The main purpose of this paper is to show that a decimal, or base 10, system can have some important inherent advantages over a binary system, such as greater daily operational efficiency. Furthermore, it is shown that a "decimal-base binary logic" system, or DBBL system, has inherent …

Parametric Analyses Of Regenerative Steam Power Cycles, Vallabh Vithalbhai Vaghani

Masters Theses

"This study analyzes the effect of inlet pressures, internal turbine efficiencies, pump efficiencies, extraction pressures and number of open feedwater heaters on the thermal efficiency of regenerative steam power cycles. Combinations of inlet and extraction pressures were introduced into digital computer programs in order to find the optimum extraction pressures for maximum thermal efficiency. The scope of study covered regenerative steam cycles with one, two, three, four, and five open feedwater heaters. One of the principle objectives of the study was to determine if there is some turbine extraction pressure or set of pressures which give maximum thermal efficiency for …

The Analysis Of An Axially Symmetric Submerged Membrane Shell, Walter Earl Wehmeyer

Masters Theses

"The general theory of large elastic deformations is applied to the problem of a liquid-filled, axisymmetric membrane which is supported on a rigid horizontal plane and subjected to a variable external pressure. The variable external pressure is caused by submerging the membrane to various depths. The variation of the hydrostatic pressure in the inflating medium as well as in the surrounding environment is considered. By assuming large meridional deformations the stress field and the deformed shapes of a submerged membrane made of a neo-Hookean material are obtained. The effect of the initial shape on the deformed configuration of the membrane …

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 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.

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. …

Concentration By Sorting : Feasibility Determination By Radial Distribution Analysis, Robert M. Doerr

Masters Theses

"A method was developed for determining certain factors for assessing the feasibility of sorting fragments of an inhomogeneous solid to concentrate a species. These factors are the typical size of zones in which the grade exceeds a selected value, and the recovery potentially achievable by sorting fragments of such size"--Abstract, page iii.

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 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 …

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 …

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 …

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 …

The Analog Simulation Of Heat Transfer Devices For The Smoothing Of A Fluctuating Fluid Temperature, Le Thai Son

Masters Theses

"Equations are written to describe a heat exchanger with electrical energy input and also a large tank system which can have electrical energy input. The output temperatures were sampled and fedback to define the energy input to the two systems. These systems were simulated on an analog computer and the ability of the two systems to smooth a fluctuating temperature input was tested. The testing of the systems included trying different types of controllers in the control system as well as different size tanks for the tank system. A satisfactory smoothing of the output temperature was demonstrated after some modifications"--Abstract, …

A Study Of Some Complexometric Titrations In Nonaqueous Solvents, Ngo The Hung

Masters Theses

"Complexometric titrations of calcium, zinc and lead with polyaminocarboxylic acids: ethylenediaminetetraacetic acid (EDTA), 1,2-diaminocyclohexanetetraacetic acid (DCTA), ethyleneglycol-bis(2-aminoethylether)tetraacetic acid (EGTA) and tetraethylenepentamine (tetren) have been investigated and compared in the following organic solvents: methanol, dimethyl formamide, dimethyl sulfoxide and methyl ethyl ketone. Various end point detection methods have been used: direct visual titration with metallochromic indicators and instrumental detection by photometry, potentiometry (mercury electrode and lead ion selective electrode) and amperometry. Calcium, zinc and lead can be determined up to trace levels (ppm) under specific conditions. A concrete application of this thesis is the determination of zinc or calcium in a …