Engineering Commons^™

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 …

Theoretical And Experimental Evaluation Of Cardiac State Utilizing Indicator Dilution Methods For Nonuniform Ventricular Mixing, Stanley Myron Welland

Dissertations

This research is directed toward the development and application of a new approach to the evaluation of cardiac work to diagnose cardiac state. A procedure has been developed for calculating the work performed on the fluid by the left ventricle during the heartbeat. The procedure involves the continuous direct measurement of ventricular fluid mixture temperature during and following the controlled injection, through a catheter, of a known volume of cold saline into the left ventricle. The measured mixture temperatures are used to calculate continuous ventricular volumes during the systolic and diastolic functions of the heartbeat. Plotting measured ventricular pressure versus …

A Kinetic Study Of The Anionic Polymerization Of Neopentylethylene Oxide, Albert Edward Meisinger

Dissertations

Kinetic data for the anionic polymerization of bulk neopentylethylene oxide were determined. The initiator used for this study was potassium t-butoxide. Polymerization runs were made at temperatures of 39.9, 60.0 and 80.3°C using monomer to initiator ratios of 50/1 and 20/1.

The polymerization reaction was found to follow pseudo first order kinetics up to about 60% polymerization and second order after this. The energy of activation for the propagation reaction was found to be 17.4 ± 1.2 K cal/mole and 18.5 ± 1.5 K cal/mole, respectively, for the pseudo first order and second order portions of the polymerization. The value …

On The Classification Of The Solution Space Of Linear Anisotropic Elasticity, Richard Clement Carman

Dissertations

A method is developed within the framework of Synge's function-space interpretation of problems in linear elasticity which allows the consideration of solutions to problems for anisotropic media in terms of the solutions of a corresponding isotropic problem and corresponding simpler anisotropic problems. The isotropic solution and simpler anisotropic solutions establish points in each of the statically and kinematically admissible spaces for the anisotropic problem. The established points are used to define sets of vectors in the statically and kinematically admissible spaces. The linear independence of these vectors can then be determined by a pair of criteria developed in this work. …

Continuous Esterification Of Lactic Acid With N-Butyl Alcohol, Robert Dix

Dissertations

A model is proposed for the reactions occurring when an aqueous 30% lactic acid solution is contacted with a primary alcohol, normal butanol. Kinetic and equilibrium data for the esterification reactions of monomeric lactic acid and dimeric lactic acid were determined in a series of experiments using an ideal overflow back-mix reactor. The variables studied were reaction temperature and catalyst concentration.

It was determined that the significant reactions occurring within this system are the esterification of monomeric lactic acid with n-butanol and the esterification of dimeric lactic acid with n-butanol. Other reactions that may be postulated to occur within the …

A Study Of The Dynamics Of Gas Adsorption In An Air Fluidized Bed, William Charles Zalewski

Dissertations

The dynamics of gas adsorption was studied in an air fluidized bed containing activated alumina particles. The adsorption studies made with a fixed bed and in the transition region between minimum fluidization velocity and 2.0 times minimum fluidization velocity, compliment work done at higher velocities. With adsorption, particle motion controlled the overall dynamics of the fluidized bed. A different approach in applying the two phase fluidization model was necessary to satisfactorily describe unsteady state adsorption in fluidized beds. Experimental and theoretical results were compared in frequency response plots to obtain a rigorous comparison. Good agreement was obtained for flow rates …

Non-Linear Analysis Of Electrocardiogram Tracings In Detection Of Occult Coronary Artery Disease, Joseph Robert Levitt

Dissertations

The general problem of identifying significant characteristics of a system by analyzing the properties of a signal emitted by that system is common to many disciplines, biological as well as physical. In general, achievement of a satisfactory solution depends on the capability of assigning membership of candidate signals to one of a number of mutually exclusive categories:

In this study, a new technique of processing the standard electrocardiograms from human subjects has been developed. This technique employs a set of non-linear transformations which enable the assignment of electrocardiograms into one of two Mutually exclusive categories. The first category is that …

Extension And Application Of The Sedov-Berdichevskii Variational Principle, Francis X. Prendergast

Dissertations

The Sedov-Berdichevskii variational principle is extended, and this extended principle is employed in the construction of a shell theory.

The extension of the principle is accomplished by the use of Lagrangian multipliers, and a redefinition of terms in order to maintain the original generality of the principle. The Euler equations of the extended variational principle provide, in addition to those obtained in the original principle, elastic and plastic kinematic relations, and, elastic and plastic constitutive relations. Also, the Euler equations of the original principle are obtained in a physically more meaningful form. Examples are given which show how this principle …

Reliability Aspects Of Semiconductor Surface Protective Coatings, Robert Edward Mcmillan

Dissertations

This research was directed towards the occurrence and im-portance of surface leakage in reverse biased semiconductor diodes and the relation of this leakage to the reliability of a device under use conditions. As a result of this study, it is possible to predict one important leakage mechanism after such back-biased diode units have been subjected to long periods of temperature and humidity. This theory is consistent with tests of commercially available units, some of which have very slight surface leakage and others very large surface leakage.

Further, the usefulness of various possible passivating coatings is critically analyzed on the basis …

Dynamic Stress Concentrations About An Epilliptical Discontinuity In An Elastic Solid, Kenneth Roy Schroll

Dissertations

The redistribution of dynamic stresses caused by the presence of an elliptical discontinuity in an infinite isotropic homogeneous elastic solid is examined. The solutions are obtained for the special cases of the rigid immovable inclusion and the vacuous cavity inclusion, and numerical results are presented.

The solutions to the wave equations in elliptical coordinates are expressed in series of the elliptical geometry eigenfunctions. Application of the boundary conditions, vanishing displacements for the rigid immovable inclusion and vanishing stresses for the cavity inclusion, yields in each case two infinite sets of linear algebraic equations for the expansion coefficients of the series …

Oscillations In Pulse Frequency Modulated Control Systems, Warren Joseph Guy

Dissertations

This dissertation is concerned with oscillations and their stability which occur in a control system containing two nonlinearities, separated by linear elements. Specifically the nonlinearities are Integral Pulse Frequency Modulators and the linear elements are described by ordinary differential equations which are linear. The IPFM can be modelled by a quantizer with hysteresis and many other PFM laws are related to IPFM, thus the study applies to more than just IPFM alone.

Boundaries on the system parameters are identified within which free oscillation may be possible. These boundaries give sufficient conditions for stability and necessary conditions for instability. Also since …

Simulation Of Periodic Tank Reactors, Noshir Pirojshaw Mistry

Dissertations

Normally it is assumed that the steady state mode of operation is most desirable for the design of the chemical reactor system. However it appears that this assumption may not be correct in many cases.

In the present work disturbances of various types were externally created and forced on a system comprising an isothermal continuous stirred tank reactor. The effects of these purposefully created disturbances were investigated by mathematically modelling the system and simulating it on a digital computer.

The change in reactor performance, as defined by the percentage change in the production rate from the steady state value, can …

Concepts In Lsi Servo-Control-Electronics, Alfons Alfred Tuszynski

Dissertations

This thesis deals with the engineering aspects of control electronics. It examines modern concepts of servo-control theory in the light of recent developments in the technology of monolithic circuits. Applicational considerations are slanted towards Aerospace standards of reliability and power-consumption economy.

Conclusions drawn from the discussion of fabrication constraints and performance requirements lead to a preference for digital implementations. Yield problems on one hand and aging effects on the other greatly reduce the feasibility rating of analog arrays.

Current practice in servo-control electronics revolves around purely analog implementations, sampled-data systems and Primitive on-off arrangements. The motivation behind the status quo …

Boiling Heat Transfer In The Presence Of Electric Fields, Ronald Francis Lovenguth

Dissertations

The effects of a non-uniform, radial D.C. electric field on the natural convection and nucleate boiling regimes in saturated pool boiling and on the peak heat flux phenomenon were determined for trichlorotrifluoroethane, carbon tetrachloride, dichloromonofluoromethane and chloroform using as a heat transfer surface a 0.02 inch diameter platinum wire.

Bubble departure diameters for the nucleate boiling region were measured by photographic means as a function of the electric field intensity at the heat transfer surface.

The application of an electric field was found to have a significant effect on the natural convection mode of heat transfer and also the peak …

Viscosity-Density Correlation Of Newtonian Liquids, Melvin Leonard Druin

Dissertations

The viscosity of monatomic liquids was modeled by an equation derived from the kinetic theory of gases. Viscosities may be calculated from data on density and molecular weight of the liquid. In adapting this relationship to polyatomic liquids, a single correction factor was developed for each of five series of homologues; n-paraffins, n-1 -alkenes, n-alkylcyclohexanes, n-alkylbenzenes and n-alcohols, to account for the deviations of the calculated viscosities from those reported, extending over a one- to three-hundred degree range. The factor is a function of reduced temperature relative to the normal boiling point, T_rB. A single equation for each …

The Mechanism Of Second Breakdown In Transistors, Eugene David Fabricius

Dissertations

The purpose of this dissertation is to examine the behavior of electrons and holes in a semiconductor or diode under conditions of high current density as a function of temperature, and to relate this behavior to the phenomenon of Second Breakdown. The approach used is that of magnetohydrodynamics, the electrons and holes being treated as a plasma "gas" embedded in the dielectric of the semiconductor.

This approach is unique in the following respects:

1. This is the first attempt to explain second breakdown in terms of magnetohydrodynamics.
2. This is the first time an explanation of pinching in a solid at room …

The Generalized Virial Equation Of State, Ghanshyam R. Patel

Dissertations

A generalized three parameter virial equation of state has been developed and tested for seven pure gases having different molecular characteristics. The equation has also been tested for more than thirteen binary gas mixtures using three different mixture rules. The final equation is as follows:

Z = 1 + B(T)/V + C(T)/V² + D(T)/V³ + E(T)/V⁴ + VF(T)/e^aV + VG(T)/e^bV

The expressions for E(T), F(T), and G(T) along the critical isotherm were derived in terms of critical properties and two constants, a and b which appear in the sixth and seventh terms in the above …

Design Of Linear Control Systems With Distributed Parameter Elements By Parameter Plane Techniques, Murray Weinberg

Dissertations

This dissertation extends the application of parameter plane techniques to a number of areas. Specifically, the parameter plane technique can now be used to determine absolute stability, relative stability, and the location of roots of the closed-loop characteristic equation of systems containing both lumped and distributed parameter elements. The advantages of utilizing this technique are that results can be obtained as two system parameters are varied simultaneously and higher order systems can be treated as easily as low order ones.

Investigation of the mapping of real roots resulted in the derivation of a theorem which relates the number of real …

Noise Spectral Density As A Diagnostic Tool For Reliability Of P-N Junctions, Young Duck Kim

Dissertations

The feasibility of choosing noise-voltage spectral density as a prediction parameter for the degradation of p-n junctions has been examined both theoretically and through a series of life-tests.

Experimental facts show that the noise-voltage spectral density, S_v(w), observed in a p-n junction under the breakdown condition tends to be "white" (which contradicts the 1/f-noise theory), and S_v(w) is inversely proportional to the breakdown current (which contradicts the shot-noise theory). Furthermore, some p-n junctions display one or more multiple peaks of S_v(w) at different current levels which can not be explained by any of the …

Relationships Between Some Properties Of Pure Homologous Organic Liquids, Herbert Rudolph Kemme

Dissertations

The vapor pressures of eleven primary straight chain alkyl chlorides and eleven primary straight chain alcohols between C3 and C16 were determined within a range of 5 to 760 mm Hg. These data were obtained by determining the boiling points of the pure materials at various pressures by using differential thermal analysis. The boiling points were determined with a precision of -.1 degree Centigrade at a 95 per cent C.I. The Antoine equation was used to analytically describe the data. The constants for this equation were determined by a multiple linear regression technique for each individual compound. The heats of …

Kinetics Of Hydrogen Reduction By Manganese Dioxide, Herbert Eugen Barner

Dissertations

Samples of synthetic pyrolusite were reduced in hydrogen at various partial pressures in the temperature range of 200° to 500°C. Most reduction experiments were conducted using a Pyrex vertical-tube reactor, in which small beds of porous particles (0.07 to 0.21 mm.) or single porous pellets of the oxide were suspended. The reaction kinetics were followed by recovering and weighing the water product formed during measured time intervals, and the intermediate reduction products were identified by X-ray diffraction analysis.

The data show that reduction proceeds through the sequence MnO₂->Mn₂O₃->OMn₃O₄- …

Linear And Adaptive Delta Modulation, John Edward Abate

Dissertations

New results are presented offering insight into the performance and optimization of linear and adaptive delta modulation, together with a comparison with pulse code modulation. The results are applied to three cases of practical importance: television, speech, and broadband signals.

The results presented can be grouped into the following three categories. First, a performance characterization of linear delta modulation (DM) is given. With the aid of certain empirical observations made from computer simulations, closed form expressions are found for granular noise, overload noise, and minimum quantization noise powers. These results permit the prediction of the optimum performance obtainable from DM …

Effects Of Partial Coherence On Holography, Michael Jay Lurie

Dissertations

The theory of two-beam holography is generalized to include quasi-monochromatic radiation of any degree of spatial coherence. It is shown that a clear, undistorted reconstruction can be obtained provided the reference beam is highly coherent. The effect of the partial coherence of the illumination is only to make the reconstructed image darker. Specifically, the amplitude of the radiation at any point of the image is proportional to the amplitude of the radiation leaving the corresponding point on the object during the exposure, times the magnitude of the coherence between the latter radiation and the reference beam. Holograms made using either …

Energy Transfer And Electron Conduction In The Fluid Transpiration Arc Column, Pin-Seng Tschang

Dissertations

The energy relaxation and electrical conductivity of an electron gas in one atmosphere argon arc discharge has been examined theoretically and observed quantitatively in an experimental arrangement. The plasma column utilized for study is the type generated in a fluid transpiration arc equipment in which the argon working fluid is injected through a porous graphite anode. The rate of forced convection is such as to insure significant electron-heavy particle nonequilibrium in the sample volume of interest. A simple model of a developing arc column with internal heat generation indicates that, with typical rates of argon injection realized in practice, the …

Kinetics Of The Lactic Acid-Butyl Alcohol Esterification Reaction, Joel Howard Kaplan

Dissertations

Kinetic and equilibrium data for the esterification reaction of monomeric lactic acid with normal butanol were determined in a series of experiments utilizing a batch stirred tank reactor. The variables studied were temperature and catalyst concentration. The kinetic data were successfully represented by the integrated equation for a second order reversible reaction.

Rate constants were obtained at three temperature levels and four catalyst levels. The observed rate constants in the catalytic reaction were linearly correlated with catalyst concentration and also satisfied the Arrhenius criterion. The activation energy and frequency factor for the uncatalyzed reaction were determined to be 13,190 calories …

Improving The Reliability Of Electronic Systems By Minimization Of The Variances And Stabilization Of The Mean Values Of The System Performance Criteria, Emil Carl Neu

Dissertations

The parameters of an electronic system are not deterministic variables; but rather because of variations in manufacturing processes, they are randomly distributed variables. In addition, aging mechanisms will cause these parameters to drift with time. As a result of both of these factors, the system performance criteria deviate from their initial design center values. This research studied the effect of component parameter variations upon these electronic system performance criteria and then presented a thesis to minimize the effect of these variations.

The distributions of the performance criteria were obtained as functions of the parameter distributions, by first approximating the performance …

Design Of Feedback Control Systems With Transport Lag By Parameter Plane Techniques, Lawrence Eisenberg

Dissertations

A method is presented for the exact determination of absolute and relative stability of linear feedback control systems containing transport or distributed lag. All results are in terms of two variable system parameters. The method utilizes an extension of modern parameter plane techniques that allows for the inclusion of transcendental functions in the system characteristic equation. The design of controllers in linear systems containing transport lag is then considered. A design technique is proposed that allows for the systematic determination of two variable controller parameters in order to meet frequency or time domain design specifications.

The design technique is formulated …

Hydrotropic Extraction Of Hydrocarbon Mixtures, Michael Jay Ram

Dissertations

The solubilities at 25°C of selected aromatics and straight chain alkanes in hydrotropic solutions of sodium xylene sulfonate and sodium cymene sulfonate were studied. The results of this investigation are shown on distribution diagrams relating the solubilities of alkane and aromatic in each phase.

Two methods were investigated to predict the experimentally determined solubilities. The semi-empirical solubility parameter approach resulted in answers that were extremely low. A purely theoretical approach involves the calculation of dispersion forces between molecules. An equation for predicting solubilities has been derived so that it is applicable to four component systems. This method results in values …