Engineering Commons^™

Separation Via Multi-Column Ph Parametric Pumping, Wei Tai Yang

Dissertations

This thesis presents the study of multi-column pH parametric pumping, a separation technique which applies the principle of parametric pumping and uses pH as control variable. Studies emphasize the mass transfer and the capability of separation by multi-column pH parametric pumping. Many operation modes of multi-column pH parapump are developed for varied objectives of separation. A Two-pH Levels Parapump is capable of enriching the product stream with solute components; a Three-pH Levels Parapump is capable of splitting components into two product streams. The separation capability of multi-column parapump is greatly superior to that of single-column parapump. As compared to cycling …

An Investigation Of The Dynamic Response Of The Activated Sludge Process, Tin-Bai Pan

Dissertations

A new mathematical model, derived from first principles of mass balance, is proposed for describing the mass transfer response of an activated sludge aeration tank in terms of a fluidized bed. The operational data to verify the proposed model were taken from an existing conventional wastewater treatment plant and a bench scale pilot plant.

The mass transfer rate, (K_dA_s), was presented by an empirical dimensionless group function as follows:

((K_dA_s)D_p/D_v) = fA_c (uD_p/ν)a ((ν/D_ν)(MLSS))^b

Or

Sh = f(A_c/A_s ) …

Correlation Of Thixotropic Parameters And Related Tests Of Blood From Human Subjects, Walter Fabisiak

Dissertations

The flow behavior of human blood is an important facet of the circulatory system as it affects all of the organs of the body. The rheological properties of whole blood provide a means of analyzing the flow of red cells and plasma through the microcirculation. A recently observed rheological characteristic of whole human blood is thixotropy, a time-dependent phenomenon. This phenomenon is caused mainly by the redistribution of an aggregated form of erythrocytes, known as rouleaux, and the non-aggregated, single erythrocytes. In order to further define and analyze the thixotropic properties of blood, the Huang model is used to quantitatively …

Thixotropic Properties Of Whole Human Blood, Jen An Su

Dissertations

The rheological property of whole blood from various human subjects was studied with a Weissenberg Rheogonio-meter, modified with a continuously variable speed drive. Experimental data showed a hysteresis loop in the shear stress versus the shear rate plot and a torque-decay in the shear stress versus the shearing time plot which is under a constant shear rate. The rheological equation previously developed by Huang was employed to define the thixotropic parameters of each whole blood sample based upon the recorded rheograms.

The altered thixotropic parameters for the blood from patients with open heart surgery at different clinical stages were quantitatively …

The Minimum Maximal-Cube Covering Approach To Switching Theory, Yu-Tsang Gene Hwang

Dissertations

This dissertation is devoted to the construction of a new algebraic structure for the K-map so that algorithms and theorems can be derived for the minimization of Boolean functions and at the same time provide for the manipulation of Boolean functions as freely as one could on the K-map.

Computer programs have been included to demonstrate the theory and numerous examples of various complexity have been worked out in the appendices.

Development And Verification Of A Laboratory Model For Use In The Study Of A Continuous Flow Pressurized Activated Sludge Process, Wayne Frederick Nolte

Dissertations

Investigations concerning the responses of domestic wastewater treated at elevated pressures have demonstrated an acceleration in the rate of biological assimilation of the waste material. The literature is not extensive, but presents much conflicting data. There has been a lack of a coherent approach to the investigation of pressure in wastewater treatment. This demonstrates the need for standard testing apparatus and procedures.

A bench scale pressurized activated sludge process was designed and constructed. The apparatus was tested over a broad range of conditions and was found to give reproducible results. Kinetic responses of the pressurized process are presented.

Theory And Design Of Cyclotron-Wave Traveling-Wave Amplifiers, Arthur H. Gottfried

Dissertations

A theory and design procedure for traveling-wave tubes using cyclotron-wave interactions is developed. An analysis is presented of the energy exchange mechanism and the axial beam velocity spread induced by the r.f. interactions. The analysis of the energy spread in a realistic model of the beam with nonzero size and nonzero space-charge density shows that higher maximum efficiencies at higher power is attainable (with collector depression) in cyclotron-wave amplifiers than in synchronous-wave amplifiers.

A one-watt, and a ten-watt cyclotron-wave amplifier at 3 GHz, utilizing bifilar helix circuits, scaled from a 2 kW, 5 GHz design, were constructed. A computer was …

Inplane And Out Of Plane Buckling Of Thick Rings Subjected To Hydrostatic Pressure, Thomas Michael Juliano

Dissertations

The problem of inplane and out of plane buckling of a thick circular ring subjected to a hydrostatic pressure is analyzed from first principals. The equations of equilibrium from nonlinear elasticity theory are used to describe two adjacent equilibrium positions, i.e., an initial and final state. The initial position problem is assumed to be governed by linear theory. The resulting incremental value equations obtained by subtracting the two equilibrium states, are also linear in nature. These problems are reduced to a one dimensional ring theory problem by the method of power series expansion of the displacements in the radial and …

Noise Performance Of The Klapper-Kratt Low Delay Fm Detector, Allan Brown Tarbell

Dissertations

In this dissertation the dual differentiator version of the Klapper-Kratt FM detector family is investigated with additive Gaussian noise. Prior analysis of this new detector family has been limited to the noiseless case.

The investigation was conducted both analytically and experimentally. First, the dual differentiator version of the Klapper-Kratt detector was mathematically analyzed, assuming an unmodulated carrier plus additive Gaussian noise. This analysis was verified by assembling the detector and measuring its performance in the laboratory.

It was discovered that the Klapper-Kratt detector without limiter performs identically to the conventional limiter discriminator in the linear improvement region. When compared to …

The Use Of Natural Sorbents For The Treatment Of Industrial Sludge Leachate, Mung Shium Jack Sheih

Dissertations

A sorbent treatment process has been developed which uses natural clay soils and fly ashes as sorbents in the treatment of the hazardous contaminants of potential sludge leachate emanating from industrial landfills. Natural sorbents (i.e., vermiculite, illite, kaolinite, zeolite, acidic and basic fly ashes) were evaluated for the removal of specific cations, anions, and organics from leachates generated from three industrial sludges (i.e., calcium fluoride, metal finishing, and petroleum). The laboratory results indicate that, rather than a single sorbent, a combination of acidic and basic sorbents in a layered system is required to reduce for the measurable contaminants present in …

Signal Processing Techniques For Analysis Of Heart Sounds And Electrocardiograms, Alan D. Bernstein

Dissertations

Audible heart sounds represent less than 5% of the vibrational energy associated with the cardiac cycle. In this study, experiments have been conducted to explore the feasibility of examining cardiac vibration by means of a single display encompassing the entire bandwidth of the oscillations and relating components at different frequencies. Zero-phase-shift digital filtering is shown to be required in producing such displays, which extend from a recognizable phonocardiogram at one frequency extreme to a recognizable apexcardiogram at the other. Certain features in mid-systole and early diastole, observed by means of this technique, appear not to have been previously described.

Frequency …

Synthesis Of Multiarea Grid Power Systems, Bharat C. Patel

Dissertations

This dissertation presents improved development in the formation of a generalized transmission loss (B)-matrix for a multiarea grid power system. In the procedure, the individual tie powers of each area are replaced by the net interchange, sneak and circulating powers. The latter two variables are directly eliminated in the power reference frame using actual impedances, unlike current methods that require the elimination of sneak and circulating currents, the formation of complex tie current model and the complex tie power model. Consequently, manipulation of large complex current, power and impedance matrices is avoided reducing both computer time and memory requirement. Further, …

Interaction Between Structures And Fluids, Rahim Falsafi-Haghighi

Dissertations

A finite element model for the study of solid-fluid interaction, with applications in flow-induced vibration analysis of reactor vessel and heat exchanger internals, is presented. The model is based on the discretization of the solid equation of motion and the fluid continuity and momentum equations and employs the solid displacements together with the fluid pressure and velocity components as the nodal degrees of freedom. This permits a realistic and accurate implementation of boundary conditions, in contrast with methods using solid displacements and fluid pressure as the only field variables. The numerical solution of the resulting matrix equation, involving non-symetric matrices, …

Dynamics Of Submerged Cylindrical Shells With Eccentric Stiffening, Kerry Kier-Ten Chu

Dissertations

A theoretical analysis is presented for treating the free vibrations of submerged, ring stiffened cylindrical shells with simply supported ends. The effects of the eccentric stiffeners are averaged over the thin-walled isotropic cylindrical shell. The energy method is utilized and the frequency equation is derived by Hamilton's Principle. All three degrees of freedom are considered. Numerical results are presented for frequencies and mode separation for several cases of interest. Comparisons with previous theoretical and experimental results indicate good agreement. The cylindrical wave approximation and the plane wave approximation for the field equation were investigated. Their applicability was evaluated and the …

The Continuous Non-Equilibrium Parametric Pump: A Theoretical And Experimental Study, John Lawrence Rak

Dissertations

A continuous parametric pump in which the feed and product streams flow steadily both in upflow and downflow (hot and cold temperatures, respectively) is examined theoretically and experimentally. The model system is Sodium Chloride-Water-Bio Rad AG11A8 Ion Retardation Resin, a physical system characterized by relatively slow interphase mass transfer rates. For short half-cycle times, where interphase equilibrium is not approached, separation of the salt from water is found to be enhanced by longer half-cycle times, smaller reservoir displacements, and longer adsorbant columns. In most cases, separation improves with increasing number of cycles. However, steadily degrading separation is found to exist …

Deposition Of Suspensions In Laminar Flow In The Entrance Region Of Channels With Diffusive, Electrostatic And Gravitational Effects, Thomas Anthony Korjack

Dissertations

This investigation entailed the consideration of the deposition of suspensions in laminar flow in the entrance region of a parallel-plate channel, and both converging and diverging channels, under the combined influences of diffusive, electrostatic and gravitational effects. The fluid phase was assumed to be incompressible, steady and laminar; the particle phase was assumed to be steady, laminar, dilute, and with negligible lift force.

The complete solution of the problem involved solving the boundary layer equations for the completely viscous fluid phase, and the particulate momentum, continuity and potential equations for the particle phase. Since the resulting equations are non-linear partial …

Paper Recycling : Recovery Of Secondary Fibers By Selective Wettability, Gary Keith Welshans

Dissertations

A separation process has been developed which recovers similar paper grades from a mixed stock by selective wettability. This process capitalizes on the various paper additives which are intended to resist water wetting and result in paper flotation. While water can be used to achieve many desirable paper separations, the detention times required are excessive, and therefore, limit any industrial application. Surface-active agents, in low concentrations, can be used advantageously by reducing the detention times for all paper while the structure of the surfactant can be used to selectively recover similar papers over a controlled time period. Detention times have …

Axisymmetric Air Jet Impinging On A Hemispherical Concave Plate, Stefan Jachna

Dissertations

This experimental study was conducted on an axisymmetric air jet impinging normally on a smooth, hemispherical, concave plate. The jet Reynolds numbers, based on bulk nozzle velocity and nozzle exit air properties, were between 14,000 and 75,000.

The impingement plate used in this work was a hemispherical surface with the radius of 94 mm.

Calibrated Pitot tubes and a micromanometer were used for pressure and velocity measurements. The Pitot tubes were mounted on precision positioning mechanisms permitting the accurate traversing of any direction in space. The test air flow rate was measured with calibrated rotometers.

The following results of this …

Reliability And Surface Degradation Aspects Of Synthetic Insulator Materials For Hv Application, Satyapal S. Bhatia

Dissertations

This study is a theoretical and experimental investigation on the state of the art of synthetic insulators for outdoor high voltage transmission systems.

The surface of a polymeric material is known to be degraded by, among other things, environmental stresses such as UV, air pollutants, etc. The reliability of an insulator material is governed by the surface and other characteristics that do not drift much as a function of stresses and time.

The surface characteristics of various synthetic materials, when these materials were exposed to UV radiation in the laboratory were studied. The changes in the surface properties of these …

Reliability Of Mos Devices : Threshold Voltage Instability, Sesha Rajamani Shankar

Dissertations

A very important factor in the reliability of MOS devices is the stability of the threshold voltage. This dissertation examines the effects of positive and negative gate bias stresses at elevated temperatures on the drift in the threshold voltage of MOS field effect transistors.

Over 400 p-channel enhancement mode devices were life tested under different temperature and gate bias conditions for periods of up to 15,000 hours, and the drift in their threshold voltages studied and analyzed. It was found that under both negative and positive bias-temperature tests, the threshold voltage drifted towards more negative values, though in the negative …

A Fast Boundary Tracking Alogorithm For Constrained Nonlinear Mathematical Programming Problems, Jacob Yaghoub Moradi

Dissertations

A fast search algorithm for the solution of nonlinear mathematical programming optimization problems is presented in this thesis. A gradient search procedure is combined with a "Boundary Tracking"(BT) method using the feasible direction finding method of Zoutendijk for generating a feasible starting direction along the feasible-infeasible boundary.

The algorithm is applied to the minimum weight design of submersible, circular, cylindrical shells reinforced by equally spaced "T" type frames. This problem had produced algorithm failure in two earlier studies and was only recently solved by the Direct Search-Feasible Direction Algorithm (DSFD) which was shown by recent comparison studies to be among …

Nonlinear Buckling Of Deep Cylindrical Shell Panels With Imperfections, Madhusudan H. Jhaveri

Dissertations

The work presented in this dissertation is devoted to the analysis of nonlinear buckling of thin cylindrical shells with imperfections. The nonlinearity of the problem treated in this dissertation is that associated with large displacements in the linear elastic range. The method used is not restricted by the magnitude of the displacements provided that the strains do not exceed the limit of proportionality.

Thus, based upon the large deflection theory, cylindrical shell panel is investigated for buckling under the action of uniform external pressure. Certain higher order infinitesimal terms which are usually neglected in the shallow shell theories, have been …

Flow Of Polymer Melt Blends Through Porous Media, James Atwood Parker

Dissertations

The flow of molten polystyrene, poly(methyl methacrylate) and three blends of these polymers has been studied in a rheogoniometer and in packed beds of unconsolidated spherical glass beads. One primary purpose of the study was to determine the behavior of polymer melt blends in porous media flow. The second major purpose of the work was to develop and test a new and powerful model for packed bed flow based upon the Huang generalized rheological constitutive equations.

Rheological characterization of the pure polymers and blends was obtained using a Roberts-Weissenberg rheogoniometer. Shear and normal stresses were measured at shear rates from …

Acoustical Holography By Holographic Interferometry, Amin Mohamed Hanafy

Dissertations

The ability to "see" with sound has long been an intriguing concept. It is apparent that ultrasonic energy can give an image of an object not obtainable with light or even with x-rays.

In this dissertation, a novel "three-step acoustical holographic imaging system" is described and several means for its implementation are analyzed. A novel holographic acoustic image converter, which constitutes a fundamental link in the three step imaging method was also developed. The use of optical holographic techniques to convert an arbitrary acoustic image to a visible image is conducted and resulted in the introduction of the new technique …

Dynamic Analysis Of Structures With Solid-Fluid Interaction, Rennee Ramona Pedrido

Dissertations

Interaction between solid and fluid has been recognized to be an important factor in the areas of aeroelasticity, hydroelasticity, and the study of flow-induced vibration in nuclear reactor components. This study develops a finite element model for interaction between an elastic solid and a fluid medium. Plane triangular finite elements have been used separately for fluid, solid, and solid-fluid continua and the equivalent mass, damping, and stiffness matrices and interaction load arrays for all elements are derived and assembled into global matrices. The global matrix differential equation of motion developed is solved in time to obtain the pressure and velocity …

Thermal Stratification And Circulation Of Water Bodies Subjected To Thermal Discharge, Mohammad A. Borhani

Dissertations

A three-dimensional analytical model for large water bodies is presented. Time histories and spatial distribution of pressure, velocity and temperature in water bodies, subjected to thermal discharge, are determined employing a digital computer. The dynamic response is obtained for a rectangular water body by applying a finite difference method to the mass, momentum and energy balance equations. These partial differential equations are algebraically manipulated to obtain; 1) three parabolic differential equations integrated temporally to find the horizontal velocity components and temperature; 2) one algebraic integral equation to get the vertical velocity component; 3) one elliptic differential equation integrated spatially to …

Application Of Multilevel Control Techniques To Classes Of Distributed Parameter Plants, Frederick Donald Chichester

Dissertations

This study concerns the application of a combination of multilevel hierarchical systems analysis techniques and Pontryagin's minimum principle (multilevel control) to the problem of controlling optimally two classes of dynamic distributed parameter plants representing concentrations balances in streams, rivers and estuaries. The concentrations treated in this study are those deemed the most effective indicators of water quality, dissolved oxygen (DO) and biochemical oxygen demand (BOD).

One class of plants treated in this study consists of linear continuous distributed parameter plants represented mathematically by sets of simultaneous partial differential equations. Optimal control of a plant of this class is initiated by …

Sodium-Initiated Polymerization Of Alpha-Methylstyrene In The Vicinity Of Its Reported Ceiling Temperature, Shuenn-Long Ou

Dissertations

No abstract provided.

The Effects Of Optical Path Perturbations During Recording On A Reconstructed Holographic Image, Stevan Israel Feldman

Dissertations

The effects of optical path perturbations occurring during recording on the reconstructed image of a hologram are investigated. It is shown that such variations of optical path are equivalent to conditions of holographic interferometry which can be classified in three categories: 1) object motion alone, 2) film motion alone, and 3) simultaneous film and object motion; all motions are defined with respect to the stationary reference source during the recording of the hologram.

The theory concerning the effects of object motion alone on the radiance distribution of a reconstructed holographic image has already been developed by previous researchers and is …

Distributed Parameter Sensitivity Theory To Solve Certain Reliability Problems, Moses Nee Buernor Ayiku

Dissertations

It is well known that in actual control systems there are uncontrolled parameter changes caused by aging of elements, temperature, pressure and effects of externalmedium, among others, which may impair the performance ofthe system. Hence, there is the need to develop systems that weakly react to these parameter fluctuations. Sensitivity theory has been developed to study some of these problems. Most of the investigations in this area, however, deal with problems in continuous systems modeled by ordinary differential equations. Even the recent publications on sensitivity problems in distributed parameter control systems are largely concerned with systems modeled by first order …