Engineering Commons^™

Removal Of Nutrients By Sorption On Activated Alumina, Checkman Michael Yue

Doctoral Dissertations

"The nutrient enrichment of surface, primarily impounded, water and the associated problems of accelerated eutrophication and prolific algal growth have become a nationwide concern. Phosphorus and nitrogen are considered to be the key elements in abating eutrophication and are contributed from many sources, natural and manmade; prominent among these is the discharge of domestic and industrial wastes.

The purpose of this study was to evaluate the removal of nutrients, primarily phosphorus and nitrogen, with activated alumina using a continuous-flow pilot plant system. Specific objectives were the: development and construction of appropriate bench and field-scale pilot plant units utilizing the rapid …

Structural Behavior Of Cold-Formed Steel Members Made Of Thick Sheets And Plates, Ai-Shen Liu

Doctoral Dissertations

"It is well-known that the current AlSI Specification for the design of cold-formed steel structural members has been developed mainly for thin steel sections. In order to extend the applicability of the specification for the design of cold-formed steel members thicker than 1/4 in., both analytical and experimental investigations have recently been conducted with special emphases on the effects of cold work on the mechanical properties of corners and the strength of bolted connections.

For the effects of cold work, previous investigations have shown that the phenomena of strain hardening and strain aging are main factors which affect the mechanical …

Direct And Inverse Heat Conduction In Rock Materials Using The Finite Element Method, Vernon Dale Allen

Doctoral Dissertations

"A finite element method is presented for solution of direct and inverse heat conduction problems in rock materials. Finite element programs for direct and inverse heat conduction problems were developed and demonstrated. Flow charts are given for the finite element programs.

The direct finite element heat conduction program changes material properties with temperature to approximate the temperature dependent properties of rock materials. An example problem was solved by the finite element method and also using Kirchoff's transformation. The finite element solution compared quite well with the Kirchoff transformation solution.

The inverse method utilizes the direct finite element heat conduction program …

Dropwise Condensation As Affected By Vapor Diffusion And Molecular Sticking, Salil K. Banerjee

Doctoral Dissertations

"Experimental values of heat flux in dropwise condensation on a gold plated vertical copper surface were determined in presence and absence of (or minute traces of) noncondensable gas. The noncondensable gas concentration varied from 0.0045% to 7.5% over a range of subcooling from 2.155 to 17.13°F and system pressure of 4.124 to 16.67 psia. The calculated heat transfer coefficient ranged from 1,545 to 11,135 Btu/hr-ft²-°F. In the part of the experiment where precautions were taken to avoid the presence of noncondensable gas in the water vapor, much higher values of heat flux were observed. Values of heat transfer coefficient ranging …

Evaluation Of Methods For The Recovery, Chemical And Toxicological Characterization Of Trace Organics, James Robert Matthews

Doctoral Dissertations

"Organic contaminants are generated in substantial quantities by the activities of man and through natural processes, and are present in natural runoff, industrial wastes, and agricultural discharges; synthetic organic chemicals, many of which are refractory and reach surface and subsurface water, are of particular significance. Earlier studies have generally emphasized the organoleptic and esthetic problems caused by trace organics, although their acute and long-term toxic potential has also been recognized.

The overall objective of this investigation was the analytical and toxicological characterization of trace organics recovered concomitantly from Missouri waters of varied character by large-scale solvent extraction (SEM) and carbon …

Mathematical Simulation Of Gas And Water Coning In Petroleum Reservoirs By The Dynamic Material Balance Technique, Visheshwar Nath Simlote

Doctoral Dissertations

"The prediction of coning behavior at a producing oil well is one of the most difficult numerical simulation problems. Because of the convergent flow patterns and small sizes of the inner grid blocks, the radial coordinate models used to study the problem have a tendency to become unstable. Since several hundred pore volumes may flow through the inner grid blocks during a rather small time interval, instabilities are likely to occur in the saturation calculations for these grid blocks. The dynamic approach to saturation calculations is a method which first computes the correct material balance and then calculates the saturation …

Measurements Of Condensation Coefficient Exhibited By Water Drops Grown On Rural Cloud Nuclei, Abbas M. Sinnarwalla

Doctoral Dissertations

"Values of condensation coefficient, ß, were experimentally determined for water drops grown on cloud nuclei in atmospheric air samples. The measured quantities were supersaturation, final drop size (6 to 7.5 µm radius), and time to grow from near dry radius to final radius. The drops were grown in a vertical-flow thermal diffusion chamber, at supersaturations near 0.5 and 1.0%. The final drop sizes were large enough so that ß did not depend upon the size of the nucleus producing a given drop. The average value of ß was 0.025 with a standard deviation of about 0.01"--Abstract, page 2.

Process Optimization By Flow Sheet Simulation, Larry Dale Gaines

Doctoral Dissertations

"PROPS, (Process Optimization System), has been used to simulate and optimize the Universal Oil Products solid phosphoric acid catalyst process for producing gasoline. PROPS, a modified version of CHESS (Chemical Engineering Simulation System), performs a complete design and economic evaluation of the process for each set of independent variables. The computational time during optimization was reduced by the use of a regression equation to determine K-values as a function of temperature and pressure. K-value data used for the regression was generated from the Chao-Seader correlation using mixtures of the gasoline components to be encountered during optimization. The regression equation produces …

Nucleate Boiling Of N-Pentane, N-Hexane And Several Mixtures Of The Two From Various Tube Arrays, Kenneth Wayne Wall

Doctoral Dissertations

"An investigation of nucleate boiling heat transfer in saturated pools of Normal Pentane, Normal Hexane and several mixtures of the two was conducted. The fluids were boiled from gold-plated, copper, cylindrical heat transfer surfaces, 4.96 inches long, and 1.048 inch in diameter. The heat transfer elements were boiled in varying vertical tube arrays at a pressure of 14.70 psia.

It was found that the mixtures boiled with a lower heat transfer coefficient than that for either pure component when boiled alone. When boiling in any of the tube bundle arrangements, the heat transfer coefficients for the upper tubes in the …

Rc-Gyrator Ladder And Rlc Symmetrical Lattice Network Synthesis - A State-Space Approach, Tien Hua

Doctoral Dissertations

"This dissertation presents two network realization procedures using the state-space approach. The first procedure is the realization of a transfer function. A state model (A,B,C,D) is obtained from the given transfer function by inspection, where A is a companion matrix. Through a similarity transformation T, another state model (F,G,H,J) is obtained, where F is a tridiagonal matrix and can be realized by a RC-gyrator ladder network. The input source is inserted in the proper position of the ladder network, and the output is obtained through a summing circuit. It is a unified procedure and uses simple algebraic computation. A general …

Hydrodynamic Mixing Model Applied To A Continuous Stirred-Tank Reactor With And Without Second-Order Reaction, Leon L. Otte

Doctoral Dissertations

Paper 1: "A hydrodynamic mixing (HDM) model, used to calculate the steady-state spatial distribution of conversion for a second-order reaction in a continuous stirred-tank reactor (CSTR) for non-premixed reactants was developed and contrasted with other methods. The HDM model is based on a segmental description of the reactor and includes turbulent mixing effects in each segment. As a test of the model, the experimental results obtained from a tubular reactor were found to be very well represented for a range of reactant ratios. Spatial distributions of concentration and segregation intensity (degree of mixing) within the CSTR were determined for a …

Solid-Fluid Drag Reduction, Ian Radin

Doctoral Dissertations

"Pressure drop measurements were made on a variety of solid-liquid suspension systems in order to study the effects of particle shape and size, concentration, fluid viscosity and tube diameter on drag reduction. Measurements were made over a wide range of Reynolds numbers in two tubes: 1/4 inch and 1 inch in diameter.

Drag reduction could always be obtained with fibrous additives of length-to-diameter ratio greater than 25-35 if the concentration was sufficiently high. The drag reduction behavior of these suspensions is different from that of high polymer and soap solutions. Laminar flow behavior is stabilized giving lower than normal friction …

Detection Of Impurities In Zinc Sulfate Electrolytes By Cyclic Voltammetry Techniques., Bruce Alan Lamping

Masters Theses

"A cyclic voltammetric technique has been developed for quantitatively detecting the presence of active chemical species present in zinc sulfate electrolytes. The experimental apparatus consisted of a pyrex "H" cell, an Al cathode encased in a Teflon holder, a carbon anode and a mercurous sulfate reference electrode. Voltammograms were obtained from industrial, purified neutral leach solution (Cominco Ltd., Trail, B.C.) acidified to give a final concentration of 0.77 M Zn⁺⁺, 1 M H₂SO₄. The polarization curves were then evaluated and used as a reference standard to compare with results obtained when various organic and …

On Finding A Minimal Multiple Fault Test Set In Combinational Networks., Dang Quang Tam

Masters Theses

"A simple and systematic approach which generates exactly a minimal multiple fault test set T mm in irredundant combinational networks is presented. It is shown that the Equivalent Sum of Product of a given network contains all the information necessary to determine this minimal test set. The failures which may occur are limited to permanent stuck at O (or 1) faults"-- Abstract, p. ii

A Study Of Some Heuristic Models For Predicting The Reflection From Spherical Surfaces., Bruce Wayne Rau

Masters Theses

"Four heuristic models' available for predicting the behavior or radiation Non regularly reflected from spherical surfaces have been studied. The four models include: the classical Lambert, the s-factor as deduced by Look, the Lommel-Seeliger, and the Euler's approach. Because each of these analyses was deduced for flat plate geometry, it was first necessary to integrate these flat plate expressions over the surface of a sphere to develop appropriate expressions for the power rejected from the surface of a sphere based upon e ach of the above theories. As an integral part of this investigation, various basic quantities were listed (i. …

The Control Of Noise In Urban Areas., Edwin Eugene Frye Jr.

Masters Theses

"Noise has recently been labeled the 'fourth pollutant' and defined by some as the 'unwanted sound' that pervades our work environments and the privacy of our homes. This concern for noise and its effects has resulted from our nation's increasing population density, the increasing use of mechanized conveniences, the influx and growing use of mass transportation systems, and the public's awareness that noise not only 'annoys' and can increase everyday tensions and anxieties, but at certain levels can cause permanent hearing loss.

In order to curb the 'noise problem' legislators and municipal representatives began applying legal controls to noisy activities …

Minorities Are Not Prepared For Accepting Jobs In The Petroleum And Petrochemical Industries., Freddie Lorace Thompson

Masters Theses

"A survey has been made from nine petroleum and petrochemical companies in the Houston area to get recommendations on the training required for minorities to secure jobs and advance in these industries. Information gathered through this survey consist of the following; (1) recommendations on careers minorities should concentrate their training to secure jobs in these industries; (2) the demand for qualified technical minority graduates far exceeds the supply; (3) a vehicle whereby minorities can be trained and inducted into the petroleum and petrochemical industries; and (4) the companies surveyed are putting forth an honest effort to increase their job mix …

Propane-Carbon Dioxide And Propylene-Carbon Dioxide Mixture Adsorption In 5a Molecular Sieves., Bui Van Hong

Masters Theses

"Measurements of the adsorption on SA molecular sieves have established that at 1 atmosphere and 24.0°c, both systems, propane-carbon dioxide and propylene-carbon dioxide, form ideal solution adsorbed phases. Total mass adsorbed ranges from 112 to 207 milligrams/gram sorbent for propane-carbon dioxide and from 130 to 207 milligrams/gram sorbent for propylene-carbon dioxide"-- Abstract, p. ii

Esca Characterization Of Flotation Products From A Lead-Zinc-Copper Concentrator On The New Lead Belt Of Southeast Missouri., Kevin Leroy Purdy

Masters Theses

"Electron spectroscopy for chemical analysis (ESCA) was used to determine the surface characteristics of products from an operating Pb-Zn-Cu concentrator on the New Lead Belt of southeast Missouri and pure galena and sphalerite samples treated with flotation reagents in concentrations similar to those used in the mills. The emphasis was on the action of surface modifiers such as Na₂Cr₂O7, starch, SO₂, CuSO₄ and NaCN in sphalerite flotation and in the galena-chalcopyrite separation. The objective of the investigation was to monitor the relative oxidation states of the mineral and reagent constituents and correlate these …

Feed-Forward Control Circuit For A Computer Controlled Dc Motor - Ac Generator Set., Richard Allan Smith

Masters Theses

"The current trend of development of generation in electric utility systems is toward complete on-line computer control of real and reactive power generation. In keeping with this trend this work is to design, construct and operate a laboratory model of a computer-controlled power system generator. The equipment design is guided by a desire to allow real time computer control and program assignment of generation levels.

This work is intended as a first step in the development of a complete on-line computer-controlled laboratory model of a power system. It will make possible the study of state-of-the-art methods of operation of power …

Two-Dimensional Radiative Transfer In Semi-Infinite Isotropically Scattering Medium., Thomas Lee Linsenbardt

Masters Theses

"Two-dimensional radiative transfer in a semi-infinite medium has been investigated. The medium was considered to be homogeneous, absorbing, non-emitting, and isotopically scattering. Cosine, step, and finite strip variations of collimated and diffuse incident radiation were considered. Collimated incident radiation was restricted to lie in planes perpendicular to the direction of its spatial variation.

Expressions for source functions, fluxes, and intensities at the boundary and inside the medium were obtained by assuming cos foe varying incident radiation. This assumption allowed the two-dimensional problem to be reduced to a one-dimensional integral equation for the source function. This integral equation vias transformed into …

Amine Flotation Of Feldspar From Magnetite Concentrate., Gary William Hudiburgh Jr.

Masters Theses

"The gangue in some magnetite ore bodies contains feldspar; the alkali content of the feldspar reduces the usefulness of these iron ores. One method of decreasing the feldspar content in magnetite concentrate is froth flotation.

The amine flotation of feldspar from magnetite concentrate was investigated using zeta potential measurements, Hallimond tube flotation tests and laboratory-scale flotation tests. The zeta potential of various feldspars (microcline, albite, anorthite, oligoclase and anorthoclase) were determined as a function of pH; the point of zero charge ranged from pH 1.4 to 2.5. Hallimond tube flotation tests using two amine reagents were conducted on the feldspars. …

Two Dimensional Radiant Interchange Between Two Isothermal Semi-Infinite Parallel Strips., Stanley Earl Mckinney

Masters Theses

"Four straight forward solution methods were used to determine the two-dimensional variation of the radiosity on two identical constant temperature, gray, semi-infinite parallel strips. Physical convergence parameters were developed for the one-dimensional case and extended to two dimensions. A study using these parameters was undertaken to identify the preferable method. The solutions obtained with this "best method" agree well with the one-dimensional solutions. The error is estimated to be less than one percent" -- Abstract, p. ii

Effect Of Nodule Count And Cooling Rate On The Matrix Of Nodular Iron., Subrata Sen Gupta

Masters Theses

"The objective of this investigation was to establish the relationship between the nodule count, the matrix structure, and the cooling rate through the eutectoid in nodular iron. The chemical composition of the nodular iron was held constant while various inoculation methods, inoculants, and mold designs, including chills, were used to vary the solidification time and cooling rate through the eutectoid range. This produced variations in both the matrix structure and the nodule count.

The nodule count has a power relationship with the percent pearlite in the matrix at fixed cooling rates: Percent pearlite = K (Nodule count)^-n where the …

Noise Power Estimation Based On Data Of Finite Sample Size., John Michael Koly

Masters Theses

"The method of z-transforms is used to derive the error performance of an average noise power estimator that utilizes data of finite sample size. Rectangular and trapezoidal integrators are employed by the estimator. Theoretical performance of each integrator is derived as a function of the number of samples utilized to form the estimate"-- Abstract, p. ii

Two-Dimensional Radiant Interchange In A Non-Isothermal Cavity Formed By Two Semi-Infinite Parallel Plates., Robert David Allen

Masters Theses

"Two-dimensional radiant interchange between non-isothermal, gray diffuse surfaces with non-uniform radiosity have been investigated for a cavity formed by two semi-infinite parallel plates. The problem is solved for two specific emissive power distribution models. Both emissive power distributions decay exponentially with depth into the cavity. The first emissive power distribution varies in a cosine manner across the front of the plates and the second has a step variation across the front of the plates.

For the cosine varying model, separation of variables and Ambarzumian's method are applied to obtain an integro-differential equation for the radiosity inside the cavity, an integral …

High Density Serial Encoded Tape Systems., Billy J. Romine

Masters Theses

"A digital approach to phase lock loop design is presented. Two separate circuits are developed and analyzed. The circuits developed have certain characteristics which can be applied to serial data encoded tape systems. One of the circuits can be expanded into a multiple track configuration with a minimum amount of hardware. The second circuit features a fast initial synchronization method over a wide input frequency range.

The application 0£ the phase lock loops to the retrieval 0£ serial encoded data is investigated. Three representative data encoding methods are considered. The approximate bit density obtainable with each encoding method is calculated …

Design Of An Auxiliary Indicator For A Fighter Aircraft., Jack L. Kubicek

Masters Theses

"The auxiliary indicator discussed in this thesis is the unit which processes signal information for a radar display indicator. The indicator provides system information to a fighter pilot in an easy to read and uncluttered manner.

The indicator displays symbols, target and advisory information for the pilot. The symbols and target information are displayed on a direct view storage tube (DVST), while pilot advisory information is displayed by means of indicator lights located around the perimeter of the display.

This thesis describes the original steps of development, starting with the original consideration of the problem and possible methods for solving …

Liquid Metal Heat Transfer In Longitudinal Flow Along A Cylinder And Flat Plate., Marvin Eugene Lohmann

Masters Theses

"In this investigation an analytical study is performed to determine the effect of axial heat conduction on laminar forced convection for longitudinal flow of liquid metals along a horizontal cylinder and a flat plate. ii

The flow and thermal boundary layers for the problems under consideration do not admit similarity solutions, the non-similarity arising from the transverse curvature; ε = (4/R) (vx/u _∞) ^½ of the cylindrical surface and from co the effect of the axial heat conduction expressible as Ω = 1/Pe_x , where Pe_x is the local Peclet number. The governing conservation equations along with …

Application Of An Inverse Heat Conduction Technique To A Simulated Injection Mold., Noel Joy Rytter

Masters Theses

"An analytical model was constructed to investigate the heat transfer in an injection mold for which the temperature was controlled by a special mold heating-cooling process. Several techniques were used to test the validity and accuracy of the analytical model of the mold and to explain some singularities that occurred. It was determined that the thickness of the plastic part being molded is the primary factor affecting the minimum cycle time for the molding operation. Also, abrupt changes in temperature on the molding surfaces are very difficult to obtain because this requires drastic temperature changes for the working fluid that …