Engineering Commons^™

Electronic Technique For Resolving Ambiguities Of Sinusoidal Function Transducers., James W. Campbell

Electrical and Computer Engineering ETDs

A circular function transducer is a device whose output is a circular trigonometric (sinusoidal) function of the input to the device. The sinusoidal nature of this class of transducer's output results in identical responses for many admissible inputs. Consequently, an ambiguity exists as to which of the many possible input values produce any particular output value. Even a history of the output from an initial reference input becomes ambiguous once the output completes one cycle of the sinusoid. To be a generally useful instrumentation component, the ambiguity of circular function transducers must be resolved.

Circular function transducers are currently used …

An Analysis Of The Impedance Of Two Types Of Electric Antennas Designed For Undersea Applications., Vincent R. Chavez

Electrical and Computer Engineering ETDs

The problem of radio wave propagation using antennas submerged in sea water has received much attention in recent years. As early as 1940 Norgorden [1] prepared a paper on the problem of propagation of radio waves from a transmitting antenna in air to a receiving loop antenna in sea water. Further work on the loop antenna was performed in 1946 by Quinn and Norgorden [2]. An analysis of a Hertzian dipole in an infinite, conducting medium was done by Tai [3] in 1947. He showed that a meaningful expression for the radiation resistance of the Hertzian dipole in a conducting …

An Analysis Of The Signal Processing In A Radio Altimeter Utilizing Random Angle Modulation, Donald F. Post

Electrical and Computer Engineering ETDs

Excerpt from the introduction:

This paper presents an analysis of the signal processing in a continuous wave, fixed-range, radio altimeter which utilizes random angle modulation, i.e., the modulating function is a sample function from a random process. The mathematical model of the altimeter is shown in block diagram form in Figure 1, and the physical situation in which the altimeter operates is illustrated in Figure 2. As shown in Figure 2, the altimeter is assumed to be on the vehicle "V" which has a relative velocity v with respect to the reflecting plane P. The velocity vector might have any …

On Stable Fractures In A Uniaxial Stress Field, Barry P. Shafer

Mechanical Engineering ETDs

The general interests of engineers in fracture mechanics are oriented through their interest in the structural strength. The studies branched into two major areas in fracture theory, namely the initiation problem and the stability problem. Although some of the initiation problems could be approached through the existing failure theories, other aspects are still active research subjects, such as the statistical theory of fracture. In the stability problem, we are faced with a situation in which the adverse condition already exists because cracks are present. Whether the presence of the crack under the loading condition is insignificant or critical is the …

Transient Radiation Effect On Semiconductor Controlled Rectifiers, Wilford D. Raburn

Electrical and Computer Engineering ETDs

Excerpt from the Introduction:

The three terminal PNPN switch which we will refer to as the semiconductor controlled rectifier or SCR has electrical characteristics quite similar to the gas thyratron [7]. In the SCR, current is carried by electrons and holes whereas, in the thyratron, it is carried by electrons and ions. Both have high impedance in the "off" state and low impedance in the "on" state. Both devices will remain in the conducting mode once they have been triggered, even if the gate signal is removed.

The operation of the SCR depends upon the internal feedback mechanism [ 22]. …

Solution Of Poisson's Equation In Two-, And Axisymmetric Three-Dimensional Geometry By Means Of A Capacitively-Coupled Conductive Paper Analog, Donald L. Hanson

Mechanical Engineering ETDs

Poisson’s equation is encountered in many branches of engineering analysis. For example, the velocity distribution of a fluid in steady laminar flow through a duct is described by Poisson’s equation. The stress distribution within cylindrical (including non-circular) torsion bars is described by the same equation. The temperature distribution within a body having distributed internal heat sources is still another physical quantity which requires the solution of Poisson’s equation for its determination. The internal heat sources of this last example may be of electrical, chemical, or nuclear origin.

Measurement Of Pressure And Velocity In A Heat Generated Acoustic Wave, Hernan Hirsch

Mechanical Engineering ETDs

The purpose of this study is (1) to investigate experimentally the magnitude and the phase angle between acoustic pressure ad velocity of the Sondhauss oscillation; (2) to investigate experimentally the pressure times velocity diagram; (3) to investigate experimentally the pressure versus volume diagram and its analogy to the Stirling heat engine, (4) to list observations of the behavior of the gas inside the tube, and the possible influence of these observations on the sound pressure level or velocity of the flow.

An Experimental Investigation Of The Continuous Penetration Of A Blunt Body Into A Simulated Cohesionless Soil., John Lewis Colp

Civil Engineering ETDs

The penetration of one object into a larger mass may well have been one of the earliest interests of man. History shows that early man was well aware of the occurrence of the penetration event by his use of spears and other projectiles in his search for food. Interest in penetration events has been continuous through man's development. Today this interest has even outstripped man's natural environment to include the serious study of penetration into extra-terrestrial bodies such as the lunar surface.

The Problem:

The penetration of many materials is currently being studied by many investigators. Some of the materials …

Electronic Computer Program For The Solution Of Slope Stability By The Wedge Method Of Analysis., James O. Boardman

Civil Engineering ETDs

Earth embankments and the foundation upon which they rest are subject to abear stresses induced by their own weight. It the embankment serves as a water retention structure, additional shear stresses are developed by seepage forces originating from pore pressure, from the reservoir pool and from rainfall. In certain regions, earthquake forces must also be added to these gravity and water forces.

Prior to the turn or the century and tor thirty some years after, earth dam side slopes were selected on the basis of past experience in lieu of a theoretical analysis. Justin, a noted authority on earth dam …

An Analysis Of Neutron Resonance Detectors In Critical Uranyl-Fluoride Heavy Water Systems., William H. Roach

Nuclear Engineering ETDs

The measurement of neutron flux spectra in reactors is a problem which can be approached in several ways, depending on the information desired. For high energy measurements, threshold detectors are often used; if spatial information of the flux is required, some type of fission detector may be employed. For flux magnitude measurements in the epithermal energy range, foils of elements which have strong neutron absorption resonances are commonly utilized. If the resonance is sufficiently isolated from other resonances and the contribution from the resonance to the total resonance absorption integral of the element is large, then it is a fairly …