Digital Commons Network^™

An Analysis Of A Quadrature Double-Sideband/Frequency Modulated Communication System, Denny Ray Townson

Masters Theses

"A QDSB/FM communication system is analyzed with emphasis placed on the QDSB demodulation process and the AGC action in the FM transmitter. The effect of noise in both the pilot and message signals is investigated. The detection gain and mean square error is calculated for the QDSB baseband demodulation process. The mean square error is also evaluated for the QDSB/FM system. The AGC circuit is simulated on a digital computer. Errors introduced into the AGC system are analyzed with emphasis placed on nonlinear gain functions for the voltage controlled amplifier"--Abstract, page ii.

Simulation Of A Gas Storage Reservoir With Leakage By A Two-Dimensional Layered Mathematical Model, Steven William Ohnimus

Doctoral Dissertations

"A generalized mathematical model was developed for two-dimensional compressible fluid flow accounting for the effects of relative permeability capillary pressure, and gravity drainage in addition to the reservoir properties of rock heterogenity and reservoir geometry. The generalized model developed was applied to an aquifer gas storage reservoir in which vertical leakage occurred from the main reservoir to two adjacent overlaying zones. The experimental results of Thomas, et al. were utilized in applying the model to gas storage injection/withdrawal periods yielding reasonable results for the three layers"--Abstract, page ii.

Iddap -- Interactive Computer Assistance For Creative Digital Design, Richard Franklin Crall

Doctoral Dissertations

"A new computer-aided design program to assist in the initial phases of logical design is described. The program, intended for use via an on-line remote terminal, will allow the designer to study and experiment with design alternatives during the initial creative design phases. An ALGOL-like language is used for specifying the system being designed. In addition to simulating the design, the program allows the user to perform on-line design changes, reorganize data and generate timing diagram information"--Abstract, page ii.

Use Of The Turbulence Kinetic Energy Equation In Prediction Of Nonequilibrium Turbulent Boundary Layers, William Madison Byrne Jr.

Doctoral Dissertations

"A differential method is proposed for the prediction of a broad range of turbulent boundary layers of engineering and scientific interest. A digital computer program is presented which is applicable to boundary layers with positive, negative, and zero pressure gradient in the main-stream direction as well as boundary layers with suction, blowing or zero mass addition at the wall. The turbulence kinetic energy equation is solved simultaneously with the longitudinal momentum and continuity equations to provide an independent means for determining the effective viscosity which makes allowance for "history" effects in the flow. It is shown that the prediction method …

Higher Space Mode Analysis Of A Large Cylindrical Pulsed H₂O System, Harold David Hollis

Doctoral Dissertations

"By utilizing a geometrically centered pulsed source internal to a large (B²_g) ≈ 0.002) cylindrical H₂O system, the neutron flux was measured as a function of position and time. A least square fit of the data yielded the fundamental and five higher decay constants and amplitudes of the thermal neutron flux. Symmetrical and enhanced neutron densities were obtained as a result of the internal source. Long waiting times were unnecessary and data acquisition was accelerated.

The decay constants were found to be independent of position, pulse width, counting time and rates, method of normalization, or waiting time. …

Effect Of Axial Dispersion On Interphase Mass Transfer In Packed Absorption Columns, Virendra Kumar Mathur

Doctoral Dissertations

"A steady state approach was followed in this investigation to determine the effects of liquid and gas flow rates, packing size and packing height on the interphase mass transfer coefficient and gas phase axial mixing Peclet numbers. Experiments were performed on the absorption of carbon dioxide from a mixture of carbon dioxide and nitrogen in a packed column. Absorption was performed using 1/4, 3/8 and l/2 inch Raschig rings, with a packing height of 3 feet and also using 3/8 inch Raschig rings with a packing height of 5 feet. The liquid and gas flow ranges used were 2865 to …

Model-Referenced Adaptive Control Of Plants With Noise And Inaccessible State Vector, Donald James Schooley

Doctoral Dissertations

"The problems of process noise, measurement noise, and inaccessible process state vector in the model-referenced system of Shackcloth-Butchart-Parks (SBP) are investigated. Since the system no longer possesses a static equilibrium point, the concept of asymptotic stability does not apply. However, by using Liapunov-like ideas, the error between the plant (process plus controller) and the model is shown to enter a region about the origin if certain bounds are known. A possible technique for reducing the size of this region is to feedback a function of the error into the plant's input. Several methods of circumventing the inaccessible state vector problem …

The Effects Of Magnetic Fields Upon The Steady State And Short Circuit Performance Of Low Voltage Multi-Link Fuses, John Thomas Schultz

Masters Theses

"The steady state and short circuit performance of multi-link fuses is investigated, as it is affected by the magnetic field of the nearby returning current and the current flowing in the fuse itself. The fuses investigated are low voltage (600 volts or less), multi-link fuses with ratings between 400 and 4000 amperes. The effects of the above mentioned magnetic fields upon the steady state current distribution within the fuse and upon the mechanical forces acting on the individual fuse links are calculated, while the effects of close proximity of the returning current upon short circuit fuse performance are shown by …

The Development And Analysis Of A System To Measure Transient Angular Velocity, David Lawrence Persson

Masters Theses

"A measuring system was built to provide a D. C. voltage which was proportional to the angular speed of a particular rotating shaft under question. The measuring system developed has a time constant of approximately .00365 seconds. The final measuring system was developed after trying various other means which proved unsatisfactory. The final device developed would be quite satisfactory in a wide variety of applications"--Abstract, page ii.

Dynamic Analysis Of Multistory Frames Considering Both Distributed And Lumped Mass, Mark E. Botkin

Masters Theses

"Two types of dynamic analysis of multistory structures are presented in this thesis . First presented is the dynamic stiffness matrix method in which the masses are distributed along the constituent members. This method is composed of statics, stiffness and loading matrices. The statics matrices are established from the structural configurations, the stiffness coefficients are formulated from the elastic properties of the members, and the loading matrices are functions of the time dependent forces or time dependent foundation movements. The applied forces may be uniform, concentrated, triangular or joint forces. Computer programs are given to carry out the laborious calculations …

Anodic Dissolution Of Zinc In Potassium Bromide-Potassium Bromate Solutions, Ying-Cheh Chuang

Masters Theses

"The purpose of this investigation was to study the anodic dissolution of zinc at a temperature of 25°C in Br⁻-BrO₃; solutions. In Br⁻ solutions, it was found that the apparent valences of zinc ions going into solution were approximately the normal value of two. Smaller values were obtained in BrO⁻₃ solutions, with the most pronounced changes occurring in the higher concentrations of BrO⁻₃. An empirical equation was derived relating the apparent valence (z_i) to the current density (amp·cm⁻²) and BrO⁻₃ concentration (gmol/liter): 2- z_i = 3.11 X i⁰̇̇¹³(C_BrO⁻₃)⁰̇⁵⁷ The mechanism for the dissolution of zinc …

A Computer Simulation Of The Internal Ballistics Of Recoilless-Rifle Rocket Launchers, John Edd Mosier

Masters Theses

"A computer program has been developed to simulate the basic mechanics and gas dynamics associated with launching a solid propellant rocket from a recoilless rifle. This program, entitled "KICKIT," may be used to predict the performance and evaluate many of the pertinent design parameters of both conventional recoilless rifles and a recoilless rocket launcher system. This program is a valuable analytical tool which enables the designer either to optimize the system design or predict the behavior of the system under off-design conditions"--Abstract, Page ii.

Digital Simulation Of A Costas Loop Demodulator In Gaussian Noise And Cw Interference, Ajay Mugatlal Mehta

Masters Theses

"A digital computer model of a Costas loop has been employed to study the effects of Gaussian noise and continuous-wave interference on the detection of biphase modulated signals. The dependence of bit-error probability, mean-square error between input and output, phase-error variance and threshold on signal-to-Gaussian-noise power ratio, interference-to-Gaussian-noise power ratio and frequency offset of the interference have been investigated and compared with previously obtained experimental results. The model has been verified for its accuracy in the case of no noise and when Gaussian noise is present at its input"--Abstract, Page ii.

Study Of Neutron Reflection From A Curved Surface Using The Monte Carlo Method, Marion Jay Rackley

Masters Theses

"The reflection patterns for neutrons impinging on both an infinite parabola and an infinite slab were studied using the Monte Carlo method. In the first case neutrons were sent into an infinite parabola (z =x²/2) moving on the XZ plane parallel to the z axis at 5 points, namely: y = 1.5, x = -1.5; y = 1.5, x = -.75; y = 1. 5, x = 0. 0; y = 15, x =.75; y = 1.5, x = 1.5. The results were that there appeared to be a "focusing" of the scattered neutrons. In the second case, neutrons were …

Fault Detection On Sequential Machines, Chung-Tao David Wang

Masters Theses

"This paper presents an algorithm for deriving an optimum test sequence for detecting faults in a synchronous machine. In this study, the flow table is used as a tool to generate the fault detection tests. The fault stuck-at-1 (or stuck-at-0 ) is said to be present when a permanent signal valued 1 (or 0) appears on a component of the machine. Only single faults are treated . The result of the procedure is one or more test sequences guaranteed to detect a set of faults (F_p). First, sequential machines with feedback lines as memory elements are considered . …

The Failure Criteria And Deformational Moduli Of Granular Rock, Kyung Chul Ko

Masters Theses

"Analytical solutions of stress for composite material are obtained by means of mathematical theory of elasticity, assuming spherical inclusions and uniform displacements of boundaries of representative elements. These solutions show that the failure criteria of composite materials are complicated functions of the elastic moduli of matrix, inclusion and composite, and the volume ratio of matrix and inclusion. Combining this theory with Griffith's theory gives a new criteria for brittle failure of granular rook. This theory appears to provide a nearly perfect model for granular rooks, inasmuch as: a) most assumptions used in other criteria are eliminated, b) most phenomena in …

A Model For Predicting The Energizing Transients Of Station Capacitor Banks, Dennis Oliver Wiitanen

Doctoral Dissertations

"A model for predicting the transients associated with energizing ungrounded wye-connected station capacitor banks was developed. The model has the capability of simulating non-simultaneous operation of the breaker poles, pre-insertion resistors, and the presence of previously energized capacitor banks at the same station. To investigate various system representations, a computer solution of the transient response of an arbitrary network and the computer solution of the generalized Thevenin impedance of a complex network are presented. A simple power system is defined and used to investigate the modeling of various system components, using the computer solution methods. Simplification of the model due …

A Simulation And Diagnosis System Incorporating Various Time Delay Models And Functional Elements, David Michael Rouse

Doctoral Dissertations

"The application of digital simulation to all phases of digital network design is considered here as oppossed [sic] to development of simulation for one or two restricted parts of the digital process. For this reason a simulator is presented which can be consistent by varying the level of expression from the simulation of architectural structures to such detailed simulation requirements as race analysis of asynchronous sequential circuits. In order to make system simulation more than just an idea, it must be capable of handling large circuits in reasonable times. It is demonstrated that functional simulation has the potential to increase …

A Study Of The Anodic Oxidation Of 1, 3-Butadiene On Platinum And Gold Electrodes, Arun Kumar Agrawal

Doctoral Dissertations

"The anodic oxidation of 1,3-butadiene on Pt and Au electrodes was studied at 70°C in solutions of H₂SO₄, K₂SO₄, K₂CO₃, and KOH with pH's ranging from 0.35 to 12.5. Reaction rates (current) were measured as a function of potential, pH, temperature, and butadiene partial pressure. A transition region (apparently a shift in the rate determining step) in case of Pt was observed in the Tafel plots. The coulombic efficiencies of oxidation to CO₂ were 85 percent in 1 N H₂SO₄ on Pt, 93 percent in 1 N KOH on Pt, and 72 percent in 1 N KOH on Au"--Abstract, Page …

Development And Application Of Cartesian Tensor Mathematics For Kinematic Analysis Of Spatial Mechanisms, Robert Myrl Crane

Doctoral Dissertations

"The complexity of spatial mechanisms in themselves and the absence of an attractive analytical tool for their study has left this field of engineering analysis largely unexplored. In recent years several analytic methods have emerged. One of the most attractive of these is the tensor method. Literature surveys reveal that the tensor method is largely unexploited in the U.S.A., with regard to spatial mechanisms as well as simpler kinematic problems. The purpose of this work is to develop tensor mathematics for application to the kinematic analysis of spatial mechanisms. Methods are developed for position solutions and the determination of velocities …

Discrimination Of Signal And Noise Events On Seismic Recordings By Linear Threshold Estimation Theory, David Nuse Peacock

Doctoral Dissertations

"The object of this study is the investigation of a linear threshold element technique for identifying surface multiples on a single seismic trace. Traces of seismic events were generated which contained primaries, surface multiples, and various levels of Gaussian random noise. Since it was necessary to separate the events as much as possible, the traces were subjected to pulse-compression deconvolution processing prior to LTE analysis. Mean frequency, peak frequency, amplitude spectrum variance, periodicity, and polarity were employed as pattern parameters. A set of weights was found that would maximize the moment of inertia of the S line distribution of the …

Investigation Of Liquid Carryover In The Girdler-Sulfide Process For Production Of Heavy Water At The Aec Savannah River Plant, Samuel Clark Allen

Doctoral Dissertations

"An investigation of the causes of liquid carryover in the Girdler-Sulfide process for the production of heavy water was carried out using 12 samples of carbon collected over a one-year time period. Organic impurities from the feedwater were concentrated by adsorption on carbon. Studies of methods for the drying of carbon showed that freeze drying resulted in the minimum reproducible moisture retention without gross loss of the adsorbed organic materials. Rotary vacuum evaporation and air drying of beds of carbon were proven to be less efficient. A study was made of the variables which affect extraction efficiency by the Soxhlet …

Numerical Simulation Of Forward Combustion In A Radial System, Tommie C. Wilson

Doctoral Dissertations

"A generalized mathematical model is described for the thermal recovery of oil in a radial system in which there are conductive heat losses to the surrounding formations, three phase fluid flow, conductive-convective heat transfer within the producing formation, combustion, and aqueous-phase changes considered. The mathematical form of the temperature equation requires that numerical solutions be obtained with a digital computer for which the numerical approximations of the partial differential equations are presented and the results discussed. The analysis is applied to field size simulations of a forward combustion project to permit direct field analyses of significant importance for accurate reproductions …

The Smelting Of Lead Drosses, Humberto Adolfo Arzabe

Masters Theses

"The constitution of the matte and bullion obtained by the smelting of lead drosses coming from the cooling of lead blast furnace bullion was investigated by metallographic, chemical, electron-microprobe, and X-ray means. At smelting temperatures (1200°C to 1300°C) two liquid phases are in equilibrium. A liquid lead phase with low concentrations of copper and sulfur, and a lighter liquid matte phase containing a high concentration of copper and sulfur with some dissolved lead. On cooling to room temperature the matte precipitates cuprous sulfide, a eutectic mixture of cuprous sulfide and lead sulfide with a deficiency of sulfur, and metallic lead …

Analysis Of Elastic Thermal Stresses By Station-Function Collocation Methods, Jaw-Kuang Wang

Masters Theses

"An approximate method for the solution of thermal stress problems is presented. The method makes use of polynomial approximations to reduce the partial differential equation to a system of linear algebraic equations or a set of first-order ordinary differential equations. This results in satisfying the differential equation at a finite number of stations. The boundary conditions are satisfied identically. Two examples of the method, presented in detail, indicate that the solutions of the biharmonic equation for the stress function and the Fourier equation for the temperature distribution have good accuracy with a minimum of labor. A generalized method is derived …

Electric Field Strength Dependency Of The Rate Of Radiation Induced Degradation In Silicon Planar Devices, Cyrus Hoshang Irani

Masters Theses

"The investigation of electric field strength dependence of the rate of damage introduction, caused by gamma and neutron irradiations in matched is reported. Groups of devices (with varying biases applied to the emitter-base and collector-base junctions to allow study of the electric field strength dependence) were exposed to ionizing gamma radiation from a Co-60 source. Similar experiments were conducted to study the field strength dependence of the rate of space-charge volume damage introduction, caused by fast neutrons (E> l0keV, fission source). The experimental results indicate that the rate of surface degradation, as reflected by the increase of the normalized surface …

Effect Of Inclination On Film Boiling, Shih-Chang Lin

Masters Theses

"The object of this investigation was to determine the effect of inclination on the heat transfer for film pool boiling. The test plate used as the heater was made of Inconel-600 and heated electrically. Liquid nitrogen at atmospheric pressure was used as the test fluid. The heater was oriented at various angles from the horizontal position with the heater surface facing both upward and downward and the heat transfer coefficient was determined for each angle over temperature differences ranging from 450ºF to 750ºF. As the heater angle was increased from 0º (horizontal) to 90º (vertical), the heat transfer coefficient increased …

Re-Design Of Cloud Chamber Instrumentation, Stanley Forrest Vaninger

Masters Theses

"Instrumentation and a new valving system is designed and built for use with an expansion type cloud chamber. Digital equipment is used for timing to improve reliability, accuracy, and flexibility, and a servo system is built using a lead compensator circuit which improves the servo system typically used with cloud chambers. Special care was taken to eliminate the sources of noise that appear in the amplified signal from the pressure transducer. The equipment needed to measure, record, and calibrate the pressure inside the chamber is built"--Abstract, page ii.

Statistical Estimate Of Positional Error Inherent In Very Low Frequency Radio Navigation (Range-Range), Jimmie D. Mcginnis

Masters Theses

"To determine the effectiveness of Very Low Frequency (VLF) navigation in certain areas of the world, it is necessary that a method be developed to estimate the positional error associated with VLF relative positioning techniques. This paper presents a method which consists of a least-mean-squared procedure to sum up the errors contributed by each station being monitored. Since phase jitter (i.e., phase fluctuation) is a random variable, a statistical approach is employed to produce a one Σ ellipse centered about the true position. In short, this method defines the size and orientation of an area called an error ellipse which …

The Cathodic Reduction Of Bromate Ions On Mercury In Neutral And Basic Solutions, Jaw-Shin Chang

Masters Theses

"The reduction of BrO⁻₃ was studied in neutral and basic solutions on a stationary Hg surface under activation controlled conditions. Coulombic efficiency studies showed that BrO⁻₃; was reduced to Br⁻ with high efficiencies. The polarization measurements lead to a proposed reaction scheme which is consistent with the experimental observations"--Abstract, page 1.