Engineering Commons^™

A Modified Redlich-Kwong Equation For Nonpolar And Slightly Polar Gases, David G. Skamenca

Theses

The PVT prediction capability of the Redlich-Kwong equation is substantially improved through the use of a generalized correlation based on the acentric factor. No experimental data is required to obtain the improved constants. Only the acentric factor and the critical properties of the pure gas are needed. The correlation of improved constants is limited to non-polar and slightly polar pure gases and mixtures in the supercritical temperature range.

The correlation applies to a reduced temperature range 1.00 le; T_R le; 1.60 and a reduced pressure range of 0.030 le; P_R le; 3.00. The correlation reduces deviations by as …

A Computer Program For The Design Of Packed Extraction Columns, George P. Gaccione

Theses

A computer program for the design of packed extraction columns has been developed. This program can operate with a minimum of data of the type that can easily be determined or estimated. The program can be used to investigate design alternates during the preparation of project cost estimates and for the final design of extraction columns.

Viscoelastic Properties Of Polymer Melts, Wu-Shiong Lee

Theses

Thirteen samples of molten polymers were used to test Spriggs and Careau Models. Two empirical equations, one for apparent viscosity and the other which is new, for primary normal stress difference, were checked with these samples also.

In order to test the models, material functions were sought for some specific flow patterns under which the experimental data were collected, and then these functions were compared with data.

Careau Model was found to be better than Spriggs Model in representing molten polymer properties but still yield large deviations. Two empirical equations fitted data quite well and were expected to be useful …

Combined Feedforward-Feedback Control Of A Fluidized-Bed Reactor, Reginald Eugene Mitchell

Theses

Feedforward control, feedback control, and combined feedforward-feedback control were studied on an analog computer to evaluate their effectiveness in controlling a fluidized-bed reactor used for the decomposition of cumene. Proportional, proportional-integral, proportional-derivative, and proportional-integral-derivative modes of control were investigated. Step changes in set-point and load were used as disturbances. The Ziegler-Nichols method and the process reaction curve method of Cohen and Coon were compared in determining values of KC, Ti, and Td which gave optimum control of the fluidized-bed reactor.

Control equation were obtained from the block diagrams of the systems and solved on an EAI TR-20 Analog Computer.

It …

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 …

The Application Of A Non-Newtonian Rheological Equation To Low-Density Polyethylene, Jeffrey N. Goldstein

Theses

A generalized non-Newtonian equation describing the rheology of molten thermoplastics is verified for low-density polyethylenes. The equation is extended to account for both rheological temperature dependency and polyethylene molecular weight dependency. The prediction of the rheology of new polyethylenes without additional experimentation is thus possible.

The Computer Evaluation Of The Natural Frequencies Of Vibrating Circular Plates With Free, Fixed And Simply Supported Edges, Thomas Michael Juliano

Theses

The natural frequencies of the transverse vibration of a thin, isotropic, circular plate with free, clamped, and simply supported edge conditions were studied extensively. The frequency equation for each edge condition was derived from the classical partial differential equation of plate vibration. These equations, which are in terms of Bessel functions, were then solved numerically to find the natural frequencies. Since the accuracy of the Bessel function values is very important in evaluating these frequencies, a comprehensive digital computer program was devised to calculate these values to eleven digit accuracy. In this Bessel function program four different methods were required …

The Oxidation Of Sulfur Dioxide In A Regenerative Reactor, Raymond Henry Edgecomb

Theses

A novel dual-unit sulfuric acid converter is depicted that performs in cyclic operation in unsteady state. A mathematical model and IBM 1130 Computer program were developed to show the temperature and conversion profiles in commercial-sized vanadium oxide catalyst beds. In the catalytic oxidation of sulfur dioxide conversions of 95-97% were attained without benefit of conventional heat exchangers. A single exchanger operating in conjunction with the dual-unit system might attain conversions as high as 99%.

Determination Of The Electronic State Of Aryl Nitrenes In An Intramolecular C-H Insertion Reaction, Ali Mohammad Khonsari

Theses

β,γ-Dideuteriopropylbenzene was obtained in 84% yield from deuteration of allylbenzene. Nitration of this compound resulted in o-nitro (β,γ-dideuteriopropyl)-benzene. Reduction of this compound gave o-(β,γ-aideuterio-propyl)aniline. o-(β,γ-Dideuteriopropyl)phenyl azide was prepared by dizotization of the aniline compound, followed by treatment with sodium azide.

Decomposition of the azide in isooctane solution by photolysis at room temperature gave no trace of deuterio-2-methylindoline (intramolecular insertion product).

Photolysis of the azide at the reflux temperature of the solvent (99?C) resulted in the formation of deuterated-2-methylindoline as the major product (40%) yield. The reaction is presumed to proceed through an aryl nitrene intermediate. Analysis of the nuclear magnetic …

An Economic Evaluation Of A Pressure Sulfuric Acid Manufacturing Plant, Daniel A. Marlin

Theses

The production of Sulfuric Acid at elevated pressures is presented with the economics for operating at one, three, five, seven, nine and thirteen atmospheres. The conventional and pressure plants are compared operating on the same basis.

The basis for a pressure plant design is obtained from an I.B.M. 1130 computer program developed for One Thousand Net Tons per Day of Sulfuric Acid. Recognized operating conditions for a conventional acid plant are incorporated in the pressure plant design program.

Sulfuric Acid manufacture with operating pressures higher than atmospheric, but less than five atmospheres, results in maximum rate of return on investment …

A Computer Program For The Optimization Of Binary Distillation In A Dual-Column System, Richard Vincent O'Lenick

Theses

A computer program is presented for the optimization of a two-column distillation system involving a two-component mixture. The economic reflux ratios in each column are determined using the McCabe-Thiele Method. Activity coefficients are computed by either the Wilson equation, the Margules equation, or both. The program is general and may be used for any binary system where the assumption of constant molal overflow is valid.

Options in the program permit use of either column in separate calculation schemes.

While the optimization effort was prepared in general terms, the initial work was directed toward the acetone-water system. Full data for this …

The Optimization Of A Catalytic Methanol Reactor Using Quench Feed, John Paul Mcburney

Theses

The production of methanol in a catalytic quench feed reactor is studied by means of a computerized model and optimized in terms of total reactor length necessary to achieve a given production rate. The methanol reaction rate can be maximized in a quench reactor through the use of cold stream feeds along the length of reactor.

Since the methanol reaction temperature is restricted to an upper limit of 405°C, the addition of cold stream feed along the adiabatic reactor enables the desired conversion to be reached. For two given levels of conversion, 12% and 15%, an optimum inlet temperature, quench …

Effect Of Column Diameter On Mixing In Water Fluidized Beds, Donald P. Schiesl

Theses

In this investigation, the effect of column diameter and flow rate on the mixing characteristics of fluidized beds were studied.

Tests were made on columns of 4, 6, 8 and 10 inches in diameter using water to fluidize glass beads of 0.0185 inches in diameter. The tests were run both at minimum and three times minimum fluidization. Step, impulse, and sinusoidal forcing signals were fed to the columns, using a sodium chloride solution as a tracer with the inlet and outlet concentrations being monitored continuously by a conductivity recorder.

The result of this study showed increased fluid dispersion with increasing …

Packed Column Simulation, Frederick W. Schmidt

Theses

The most difficult and time consuming aspect of the design of packed columns is the hydraulic part. If the designer wants to try many different conditions, many repetitive calculations will have to be performed. Also, some inaccuracy is incurred when trying to use the U.S. Stoneware curves. The graphs are hard to read and almost impossible to interpolate between the parametric lines. The purpose of the program is to give a more accurate calculation by using equations for the pressure drop lines, interpolating between them and correcting for gas density for each foot of packing. The program also allows changes …

Batch Heat Transfer To Suspensions In An Agitated Vessel, John Philip Horzepa

Theses

Batch heat transfer data was experimentally determined for two phase (solid?liquid) systems in a baffled agitated vessel. Three iron oxide and water and two kaolin and water suspensions were evaluated and were found to be pseudoplastic. A total of 231 heating and cooling data points were examined. Each suspension was evaluated using anchor, paddle, propeller and turbine impellers. Various sizes of the latter three impellers were used.

The experimental heat transfer results for suspensions were compared with the Hagedorn and Salamone correlation for pseudoplastic liquids. Only partial agreement with the more dilute suspensions was obtained. Overall, the data for suspensions …

A Comparative Analysis Of Multicomponent Distillation Minimum Reflux Methods, Joesph H. F. Loozen

Theses

One of the most important factors to know in the design of distillation columns is the minimum reflux ratio. Numerous procedures have been developed for the determination of the value of the minimum reflux ratio for multicomponent mixtures requiring various degrees of computational effort. Shortcut techniques are obviously advantageous with respect to computation time. After reviewing the available methods, those by Underwood, Colburn, Scheibel and Montross, Murdoch and Holland, and Shiras et al. were selected for further evaluation, mainly on the basis of practical potential.

Comparison of these procedures was accomplished by calculating the minimum reflux ratio for a large …

The Effect Of Polymerization Variables On Reaction Rate And Intrinsic Viscosity, David H. Smith

Theses

The free radical solution polymerization of vinyl acetate in benzene was studied under simulated commercial conditions. The effects of monomer, initiator, inhibitor, and chain transfer agent concentration on the reaction rate and intrinsic viscosity were examined. The initial reaction rates with monomer concentrations from 40% to 70% and AIBN concentrations from 0.2% to 0.5% were in agreement with the kinetic equation, - d[M]/dT = K[M]² [I]^1/2. After the initial reaction there was an increase in the reaction rate apparently associated with high viscosities, which is consistent with the Trommsdorff effect. The addition of hundredths of a percent …

Fluid Friction Reduction By Water Soluble Linear High Polymers, Arthur Edward Davis

Theses

The effects of various dilute aqueous linear high polymer solutions on turbulent pipe flow were studied to determine the polymer most suitable for testing as the drag reducing component in the proposed coating. Results of this study are presented for commercial schedule 40 1/4 inch NPS black iron pipe. Tests were conducted at Reynolds numbers of 6.2x10⁴,8.3x10⁴ and 9.8x10⁴.

Attempts were made to prepare a coating containing a friction drag reducing polymer - Polyhall 295 polyacrylamide - utilizing various techniques of polymer incorporation into the paint including several grinding and dispersion methods, adding the polymer …

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 …

Correlation Of 1/F Noise With Threshold Drift In Mosfet's, John Peter Rooney

Theses

A brief review of the fundamentals of MOSFET's is given. A correlation between threshold drift and surface states is made, with a following correlation between surface states and 1/f noise. It therefore follows that MOSFET's with a high 1/f noise level will drift more than those with a low level of 1/f noise. Experiments were carried out to show this effect, but no clear cut conclusions can be drawn from the experimental work.

A Computer Program For Determining Hinshelwood Rate Mechanisims From Nonisothermal Pellet Data, Joseph J. Atkins

Theses

Methods of determining Hinshelwood rate correlations from non isothermal catalyst data was studied. It was determined for any chemical system involving a reacting gas mixture over a porous catalyst a node analysis could be used to determine chemical concentration and temperature variation through the pellet. Calculation performed with a spectra 360/Fortran 4 program defined the Hinshelwood equation from estimated surface rates. Then utilising nods analysis to determine concentration and temperature variance, transport and rate equations were integrated through the pellet to obtain a total pellet rate of reaction. For acceptance of Hinshelwood equations the calculated total rate must equal the …

The Effect Of Organic And Inorganic Salt On The Relative Volatility Of Non-Aqueous Systems, Glenn W. Lindberg

Theses

The effects of dissolved salts on the vapor-liquid equilibrium of two non-aqueous binary systems have been studied. Vapor-liquid equilibrium data were taken for the binary systems ethanol - n-hexane and ethanol - hexene-1. Then potassium acetate was dissolved in each of the binary systems at a level of 1.5 mole per cent and equilibrium data were collected. The effect of the dissolved potassium acetate at this low concentration was found to be minimal.

Greater levels of salt solubility could be achieved only in the binary systems containing high ethanol concentrations. Consequently, the 15 mole per cent n-hexane in ethanol binary …

P-V-T Properties Of Hydrogen And Mixtures Containing Hydrogen (With A Generalized B-W-R Equation Of State), Arnold Brief

Theses

A Generalized B-W-R Equation of State is tested for hydrogen which is a quantum gas and for systems containing hydrogen.

The gases and systems studied are: hydrogen, nitrogen-hydrogen methane-hydrogen and ethane-hydrogen.

The pressure is calculated using observed P-V-T data and the deviation is computed therefrom. For the pure gas, hydrogen, the generalized equation is compared against the original B-Vi-R equation. For mixtures, the Gunn-Chueh-Prausnitz method which is used to calculate the pseudo-critical conditions of the mixture is compared against the Prausnitz-Gunn method.

The ranges studied in this paper are as follows:pure hydrogen 30-773°K and 1 to 1200 atm., n itrogen-hydrogen …

Hypothetical Liquid Fugacity Coefficients, Douglas F. Patterson

Theses

The object of this thesis was to derive values of the hypothetical liquid fugacity coefficient of carbon dioxide for various temperatures and pressures. Most of the temperatures studied were above the critical temperature of carbon dioxide and thus carbon dioxide could not truly exist as a pure liquid. Hence the prefix "hypothetical" was used to acknowledge this apparent discrepancy. Carbon dioxide was purposely chosen for this reason. Also,the necessary data for carbon dioxide were generally more available than for any other normally gaseous solute.

The hypothetical liquid fugacity coefficients were derived from the published binary vapor-liquid equilibrium data of carbon …

The Effect Of Flow Rate And L/D Ratio On The Frequency Response Of Water Fluidized Beds, Arnold Ludke

Theses

In this investigation, the dynamics of a water fluidized bed with varying L/D ratio and flow rate were analyzed both theoretically and experimentally, and the results of the two were compared.

The theoretical analysis was based on the standard method of Laplace transforms and transfer function synthesis.

The experimental investigation was conducted using standard frequency response techniques.

The mathematical model used consisted of a series of non-interacting perfectly mixed cells plus a distance velocity lag.

At low flow rates (3 to 6 times minimum fluidization velocity) the experimental data (in the form of Bode plots) were found to be in …

A New Technique For The Solution Of Free Convection Mass Transfer Boundary Value Problems, James Lewis Putman

Theses

Free convection mass transfer in boundary layer flow due to density difference in an isothermal model was studied. Previous work was examined and a quasilinearization technique was chosen to linearize the system of nonlinear partial differential equations resulting from the boundary layer continuity, momentum, and diffusion equations. This system of linear ordinary differential equations was solved by a computer program utilizing an iterative Gauss Jordan matrix solution technique. Results are presented and the convergence rate of the variables is plotted for each variable as a function of the distance from the boundary layer.