Engineering Commons^™

The Effect Of Variable Properties On The Laminar Flow Of Gases, Norman Shilling

Dissertations

The problem of heat transfer in laminar flow of a gas through a constant diameter cylindrical tube is treated. The gas is cooled by the tube walls held at constant temperature. Two tube inlet conditions are considered: (1) fully developed velocity and uniform temperature profiles (Graetz boundary condition) and (2) uniform velocity and temperature (UTV) profiles. Results of the theoretical and experimental phases of the work are presented.

The theoretical solution is based on the compressible boundary layer equations with varying transport and thermodynamic property terms retained. For the Graetz condition, an existing finite difference solution scheme is modified for …

The Oxidation Of Carbon Monoxide By Magnesium Aluminate, James A. Whelan

Dissertations

In this research the catalytic oxidation of carbon monoxide was investigated on magnesium aluminate catalysts, MgO:xAl₂O₃, with five different compositions, x, ranging from 1.0 to 3.0. The reaction was run at temperatures ranging from 500 to 600 °C. with radioactive carbon monoxide as the tracer. An experimental technique has been devised for the analysis of unreacted CO which takes into account a correction for the solubility of CO in CO₂.

Four mathematical models were postulated to explain the mechanism of reaction. The models were examined against experimental data by means of non-linear least squares …

Centering In Parallel Channel Systems, Allen Katz

Dissertations

Several types of signal processing systems in which the signal flows along parallel channels in a fashion similar to the auditory system have been investigated. The effect of excitation with signals containing both single and multiple spectral peaks (formants) was considered. In particular, the effect of nonlinear interaction between channels, referred to as centering, in the presence of noise was studied.

These systems were investigated for their value, both as information processing networks and as models of the auditory system.

The analysis indicates that parallel channel systems, in general, exhibit excellent performance in the presence of noise, and that a …

Sidelobe Suppression In Chirp Radar Systems, Stephen N. Honickman

Dissertations

Pulse radars extend target range detection by increasing the transmitted pulse width. On the other hand, target resolution is enhanced by reducing the system pulse width. These dichotomous requirements led to the invention of chirp radar systems which achieve greater target resolution for a given detectable range by frequency modulating the carrier frequency of the transmitted pulse. Along with the advent of chirp radars came the extremely simple and reliable technique of chirp signal generation known as "passive generation". However, one of the undesirable features of "passive generation" lies in the infinite time required for transmission of the resultant pulse, …

Local Mole Fraction Equations For The Excess Free Energy Of Mixing, Jose Mario Marina

Dissertations

An extensive study of local mole fraction equations aimed at obtaining a two parameter expression for the Excess Free Energy of miscible and immiscible systems has been undertaken.

Initially our approach was to modify existing equations by substituting those parameters reflecting interaction between like molecules by the pure component energies of vaporization. This resulted in a one parameter modification of the three parameter Wilson equation, which correlates data poorly and a two parameter modification of the NRTL equation which correlates binary miscible data with fair accuracy. A modification of the Scatchard-Hildebrand equation, where mole fractions are substituted by local mole …

Transverse Vibration Of A Class Of Orthotropic Plates, Nicholas J. De Capua

Dissertations

This study determines the eigenvalues, eigenvectors, and nodal patterns of a class of orthotropic plates whose geometry is governed by the equation

(x/a)^α + (y/b)^β = 1,

where the parameters a, b, a, and a permit the plate geometry to vary over a range which includes the rhombus, circle, ellipse, square, and rectangle.

Variable thickness, inplane forces, and mixed or discontinuous boundary conditions are also considered. The following assumptions have been employed:

i). plate is thin with respect to other dimensions,

ii). deflections are small,

iii). rotary inertia and shear are neglected.

The method of analysis employed is …

A Theoretical And Experimental Study Of The Mechanism Of Axoplasmic Convection In Nerve Fibers Driven By Peristaltic Surface Waves, Robert John Biondi

Dissertations

In the study of cell biology, investigators have found that substances which are produced within the cell nucleus are sometimes found throughout the cell at points distant from the site of production. In the case of nerve cells (neurons), this is particularly dramatic because of the unusual elongated geometry of these cells.

A neuron possesses a cylindrical tubular extension called an "axon" or "axis cylinder" which is characterized by a large length-to-diameter ratio (10³-10⁶). The existence of a continuous proximo-distal flow of axoplasm within these cylindrical axons has now been demonstrated by numerous investigators. In …