Engineering Commons^™

Photoelastic Investigation Of Load Transfer In Eccentrically Loaded Single Lap Joints, Stephen Antrim Hann

Mechanical & Aerospace Engineering Theses & Dissertations

Photoelastic models of three eccentrically loaded single lap joints were analyzed. The adherends of each joint were identical and the bondlines differed in thickness and material properties. The adherends were analyzed for both cylindrical plate behavior and geometrical nonlinearity and the load transfer efficiency was examined. For all three models it was found that over 98% of the shank behaves as a cylindrical plate and that a geometrically nonlinear analysis yields bending stresses substantially lower than a linear analysis and that a relatively thick, low modulus bondline can increase load transfer efficiency.

Analysis Of Oscillations In Nonlinear Systems Using Multiple Input Describing Functions, Frederic Lee Swern

Dissertations

Sufficient conditions for oscillation as well as absence of oscillations are presented for a class of systems containing one lumped linear element and a differentiable nonlinearity. The results are obtained by estimating the error inherent in using a describing function analysis. Contraction type arguments are used to show common topological properties of the describing function solution and the balance of first harmonic terms of the system.

After discussing the describing function method, two theorems are presented regarding existence or nonexistence of oscillations from homotopic considerations. A graphical method for examining systems with power law nonlinearities is given using a parameter …

Deposition Of Particles In Vertical Conduits Due To Electrostatic Charge, Diffusion, And Gravity, Melvin Wilbur Gelber

Dissertations

This investigation was made to determine the effect on the deposition of fine particles in a vertical channel and in a vertical tube due to the influences of electrostatic charge, diffusion, and gravity acting in the direction of flow. The flow considered was laminar, incompressible and steady.

The governing equations for the fluid phase were derived from the Navier-Stokes equation and the continuity equation while the equations for the particle phase were derived from Poisson's potential equation and the continuity equation. Since the governing equations are non-linear partial differential equations the solutions were developed using numerical methods.

The flow patterns …

Mathematical Modeling And Analytical Solutions Of Dissolved Oxygen And Biochemical Oxygen Demand Profiles Under Three-Dimensional, Unsteady-State Conditions, Uing Woong Kim

Dissertations

Mathematical models describing the temporal and spatial distribution of Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD) for both pervious and impervious channel conditions in 3-dimensions have been constructed, and their analytical solutions were obtained. The solutions were implemented through the application of a digital computer, and their results are presented.

It has been found that there are significant differences in terms of DO and BOD distribution with respect to time and space in relatively deep and wide channels, thus necessitating the use of a 3-D, unsteady-state model.

Investigations Of Gate Turn-Off Structures, Hans Werner Becke

Dissertations

Research and Development was done on gate turn-off devices. The aim was i) to improve turn-off capability without compromise of turn-on, on-state, and useful temperature range, ii) to implement "safe" turn-off.

A) The dependence of the electrical device characteristics on cathode width for an optimized vertical structure was determined. Fall times of 100 to 200 nsec and risetimes of <400 nsec were simultaneously obtained for average current densities of 53 A/cm² @ T_j = 125°C. From spreading resistance analysis the fast t_r and t_f response is shown to be a consequence of proper Au-distribution in the active device volume.

From transient analysis it is concluded that for safe …

Statistical Averaging In Position Determination By Holography Under Turbulence Conditions, Paul Aloysius Mcgovern

Dissertations

An investigation of several, disparate phenomena is conducted with the aim of developing a novel surveying system capable of overcoming the limitations imposed by turbulence in modern surveying. This method incorporates standard holographic techniques and time domain statistical averaging of survey data.

Some pertinent characteristics of atmospheric turbulence are reviewed, and the restrictions imposed on standard surveying practices by such turbulence are identified. A model for the turbulent medium is proposed on the basis of previous work and several theoretical results are summarized and extended.

On this basis the technical characteristics of the proposed technique are developed and each step …

Correlation And Prediction Of Vapor-Liquid Equilibrium In Electrolytic Solutions, Anil Krishna Rastogi

Dissertations

Two expressions for the excess Gibbs free energy are presented which correlate and predict vapor-liquid equilibrium and the mean molal activity coefficient of an electrolyte in a ternary mixture containing water and either MeOH or EtOH. The proposed equations take into account coulombic forces between ions and the physical interaction forces between ion-solvent and solvent-solvent molecules in a solution.

Model #1 is a combination of an extended Debye and Huckel equation and the local composition of non-random two liquid (NRTL) model. A ternary mixture requires six adjustable binary parameters to predict activity coefficients. These six parameters are evaluated from three …

Separation Of Proteins Via Continuous Ph Parametric Pumping, Steve Wu

Dissertations

This dissertation covers the separation of proteins via recuperative mode pH parametric pumping. Continuous pH parametric pumping separations using the model system haemoglobin and albumin on a CM-Sepharose cation exchanger have been experimentally and theoretically investigated.

The pH parametric pumping system has a feed containing the protein mixture to be separated, introduced alternately to the top and bottom of the column. The top and bottom products are withdrawn from the apparatus during the bottom and top feed, respectively. Both equilibrium and nonequilibrium cases were considered, and theoretical results agreed with the experimental data.

Buffer concentration, flow rate, reservoir displacement, and …

Parametric Pumping With Ph And Ionic Strength : Enzyme Purification, Zikri Mostafa Ahmed

Dissertations

The work on separation and purification of proteins by parametric pumping has been restricted so far to pH parametric pumping where the difference between the iso-electric points of the components to be separated is apparent. The present work establishes the foundations for the continuous separation and purification of proteins (including enzyms) that have similar or very close iso-electric points by using the ionic strength as a driving force for the separation process. This technique has commercial advantages over batch processes.

It was found that the most promising technique for separating alkaline phosphatase consists of the following three major steps: (I) …

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 …

United States V. Western Europe : A Comparative Study Of Safeguarding Practice Against Hazards At The Point Of Operation In Metal Forming Systems, Jeffrey Joseph Schwalje

Theses

The problem of assuring safety for the worker at the point of operation of a metal stamping system is complex by virtue of the multiplicity of combinations possible between all conceivable dies and a press of suitable capacity.

The means of providing safeguarding prescriptions is further compounded by maintaining a viable means to enforce the safety regulations as demanded by law.

A comparative study of the approach to this problem was made between the practices in the United States with that of Great Britain, France and West Germany.

This was accomplished through the study of the available standards, codes and …

Mathematical Modeling Of Jet Bubbling Reactor, Fred Jyh-Woei Cheng

Theses

A jet bubbling reactor for flue gas desulfurization is described by a mathematical model with the concept of two-stages mass transfer with chemical reactions. The Model consists of two coupling differential equations which are solved simultaneously. The result from the theoretical model is agreeable SO₂ removal data obtained from a pilot plant reactor.

Control Of Construction Costs During Construction, David H. Foo

Theses

The construction of a major project requires a vast amount of time, money, material and human resources. Proper coordination of these elements into an array of activities is crutial to the success of the project if it is to be built on time and within budget. As technology advances, the complexity of the project increases the resources to build them remain finite, and therefore, the project manager must seek methods to improve control on the construction project.

This thesis provides an overall view of the relatively new and rapidly expanding field of cost engineering. Cost engineering may be defined as …

Direct Simple Shear Tests On Overconsolidated Anderten Clay, Maral Bedian

Theses

Determining the shear strength behaviour of a very stiff calcareous clay in the Direct-Simple Shear tests is the purpose of this thesis. The clay tested is the MLK Arderten Clay from West Germany.

For the Direct-Simple Shear tests, a trimming device was prepared to get the required size of the samples. Porous stones with nails were used to prevent the slippage of the samples.

The results of the Consolidated K_o Undrained Direct-Simple Shear tests showed that the shear strength of the clay depended largely on the condition of the samples tested. Relatively homogeneous and intact samples had shear strength …

The Heterogeneous Catalytic Decomposition Of Isopropyl Alcohol Over 0.5% Platinum On 4-8 Mesh Charcoal Catalyst Support, Thomas Michael Kudenchak

Theses

The heterogeneous catalytic decomposition of isopropyl alcohol vapor over 0.5% platinum on (4-8 mesh) charcoal support catalyst was studied at bench-top in a fixed-bed tubular micro-reactor of about 1 cm ID, six inches long containing one or two grams of catalyst. Reactor feed and exit gas analysis was obtained by gas chromatography.

Experimental runs aimed at determining the Arrhenius parameters and the reaction order (assuming the applicability of a simple power law model) were performed with 1 and 2 grams of catalyst at various residence times ranging from 0.24 to 2.3 seconds and temperatures of 150°, 175°, 200°, 225°, and …

A Purely Chemical Nitrogen Dioxide Laser, Conrado Mendoza Malalis

Theses

Purely chemical lasers promise to provide future high-power lasers for remote installations, airplanes, ships and in space without the necessity of external electric power, sources.

This study is about the design and construction of a new, gas phase purely chemical NO₂ laser, based on the reaction of NO + O₃ + NO≠₂ + O₂. The vibrationally excited NO≠₂ species at 1-40 mm Hg total pressure is the source of energy (photons) for the laser. A series of computer program calculations on the reaction kinetics and relaxational processes involved have also been made, …

Synthesis And Evaluation Od Ashless Polymeric Lube Oil Addtives Containing Phosphorus, Sulphur And Nitrogen, Salwa Salah Nasr

Archived Theses and Dissertations

No abstract provided.

Mining The Deep Seabed Implications For International Law And American Foreign Policy, Steven H. Fitzgerald

Graduate Program in International Studies Theses & Dissertations

Whether or not the United States may someday face a mineral shortage, the need for a coherent, unified minerals policy is critical to national objectives and national security. Deep-sea mining may be the answer to American (and world) mineral needs in the twenty-first century. However, there are numerous problems which must be dealt with and resolved in the near future, in order to enable the U.S. (and the world community) to take advantage of vast undersea resources. Deep-sea mining requires the development of technology, tremendous capital investments, and years of labor before production can begin. U.S. policy makers must decide …

Simulated Use Of The Exponential Polynomial/Maximum Likelihood Technique In Developing Suitability Of Use Functions For Fish Habitat, Kenneth A. Voos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this paper is to present a new methodology for producing fish habitat suitability at use functions. The suitability functions are relative measures of the voluntary or involuntary preference for combinations of the values of environmental attributes by a fish species and age class. This suitability function is used to determine the relative usability of a physical stream environment as fish habitat.

A generalized function form, exponential polynomials, was selected for the development of these suitability of use functions. The maximum likelihood technique was used for function parameter solution. Derivation of the suitability functions was simulated for several …

Analysis Of A Solar Collector In An Absorption Cycle Including A Pump Operated By Thermoelectric Cells, Stuart Jee-Fong Chen

Retrospective Theses and Dissertations

A mathematical computer model has been developed for the prediction of the thermal performance of a flat-plate solar collector used as the generator for an absorption cycle cooling system. The system employs thermoelectric cells to power its pump. The exponential relationship between the auxiliary energy and the collector area is used to optimize the system. It is predicted that the system will become feasible when the fuel price is raised to four times the current value.

Ground Access To The Orlando International Airport: Design And Evaluation Of Various Mass Transportation Alternatives, George S. Fan

Retrospective Theses and Dissertations

This research presents designs and evaluations of various mass transportation alternatives for reducing the problem of the ground access congestion in the Orlando International Airport. The alternatives considered in this research are conventional bus service, minibus service, express bus service, light rail transit service, rail rapid transit service, and monorail service. Details of the origin-destination studies for the present traffic are given. A discussion of the various mass transportation alternatives is provided, with provisions for future systems expansion. Three economic evaluation methods were used in this research for evaluation of various alternatives. According to the results of the economic analysis, …

Project Network Scheduling With Limited Resources Using Heuristic Solution Techniques, Enrique J. Daboin Rojas

Retrospective Theses and Dissertations

Traditional critical path methods imply the assumption of unlimited availability of resources. Mathematical models and heuristic techniques are two alternatives that consider resource limitation to sequence the activities of a project. This research explores the consideration of project scheduling under resource constraints for the specific case of single resource, single project scheduling. A computer model called GENRES-II search model is developed using a modification of Brooks' algorithm to develop project schedules. The criteria used are various weighted combinations of ACTIM, ACTRES and ACTFOL. An improvement of GENRES-II solutions is obtained when the best set of GEN-II values is input to …

Testing The Radio Shack Random Number Generator To Produce Uniform And Non-Uniform Random Numbers, Enrique Menendez

Retrospective Theses and Dissertations

Random numbers are a basic part in a Simulation Model, and they are also used in random sampling. These techniques are employed by quality engineers in the successful execution of their jobs. The every-day use of random numbers, however, often leads to a sense of complacency in he mind of engineers toward the exacting requirements that should be satisfied by the random number process to generate a genuine random number. Microcomputers have become a common and powerful tool that helps managers and engineers in their simulation experiments by providing sequences of random numbers. This research presents a sequence of eight …

Economics Of Residential Heat Recovery Units, Muhammad N. Redhwi

Retrospective Theses and Dissertations

Determining residential airconditioning waste heat recovery system costs and savings is achieved using a computer program. A worksheet is designed to accept consumer data as an input to the program. The program features load and waste heat recovery calculations on a monthly basis. Economic criteria, including rate of return, present worth, and payback period are computed. Sensitivity of these criteria to fuel escalation and consumer discount rate is demonstrated. the program provides the user with both thermal analysis and economic analysis summary reports.

An Experimental Comparison Of Cross Correlator Performances Based Upon Signal-To-Noise Ratios, Sunder G. Gopani

Retrospective Theses and Dissertations

Three commonly employed types of cross correlators were designed using standardized components which closely simulate idealized elements in an effort to experimentally verify the theoretical analysis. These cross correlators are (1) the standard analog cross correlator which consists of bandpass filters, a multiplier and a postmultiplier lowpass filter, (2) the polarity coincidence correlator (PCC) which utilizes a hard clipper in each input channel, and (3) a modified type of PCC which features a hard clipper in only one of the input channels. Two different types of filters viz. (1) the seventh-order Butterworth lowpass filter, and (2) the five-pole Chebyshev lowpass …

Digital Acoustic Tracking Analysis Program, George H. Ford

Retrospective Theses and Dissertations

The purpose of this report is to investigate the processing of tracking data for acoustic targets. The programs developed for two- and three- dimensional space calculate the target's position via "hyperbolic-fix" navigation (geometric) considerations using the Newton-Raphson algorithm. The computer programs and the tracking solution approach contained herein is based on knowledge of only the sensors' locations and the relative time-difference at which a target's referenced, singular, acoustic pressure wavefronts are received at the sensors. Omnidirectional sensors are found to be sufficient for the two-dimensional space tracking problem. However, it is found that the three-space problem required usage of directional …

A Model For Assessing The Economic And Energy Savings Implications Of Cogeneration With Steam Turbines In Citrus Processing Plants, Harold L. Carpenter

Retrospective Theses and Dissertations

A cogeneration system using a noncondensing steam turbine to simultaneously provide electricity and process steam to a citrus plant was modeled in order to assess the source energy savings and the economic implications with the employment of this type system under conditions of time varying plant energy demand. Average monthly energy demand data from on citrus plant was analyzed. It was determined that the important parameter, in addition to a minimum demand level, for assessing economic acceptability is the demand thermal to electric ratio. One set of steam conditions will not necessarily provide the maximum source energy savings and at …

Comparative Study Of Inflation Techniques Currently Used In Engineering Economy Studies, Thinh P. Dong

Retrospective Theses and Dissertations

Recent increases in inflation rates make it essential that inflation be considered and properly treated in engineering economic studies. This research report presents a survey to determine how practitioners of engineering economics are accounting for inflation in their studies. After looking at inflation in general, and defining it, this report identifies the major existing techniques of handling inflation. It then discusses each in terms of advantages and disadvantage in evaluating investment projects. Finally, the report recommends an appropriate technique, and presents a computer program which calculates the present worth based on this technique which permits the user to analyze the …

Low Speed Handling Characteristics Of A Supersonic Transport By Eigenstructure Assignment, Michael Peter Lazar

Mechanical & Aerospace Engineering Theses & Dissertations

A synthesis procedure, based upon optimal regulator theory and eigenvalue/eigenvector assignment technique, was used in the design of a low-speed lateral control system for the SCAT-15F supersonic transport. Emphasis was placed on reducing the lateral acceleration at the pilot's station. Control laws were designed to make the aircraft handling characteristics acceptable with the exception of the lateral acceleration. It was found that a compromise between the roll performance requirements and the peak lateral acceleration requirement is needed for a successful SCAT-15F design.

Goertler Instability In Compressible Boundary Layers Along Curved Surfaces With Suction And Cooling, Alok K. Verma

Mechanical & Aerospace Engineering Theses & Dissertations

The Goertler instability of the laminar compressible boundary layer flows along concave surfaces is investigated. The linearized disturbance equations for the three-dimensional, counter-rotating streamwise vortices in two dimensional boundary layers are presented in an orthogonal curvilinear coordinates. The basic approximation of the disturbance equations, that includes the effect of the growth of the boundary layer, is considered and solved numerically. The effect of compressibility on critical stability limits, growth rates, and amplitude ratios of the vortices is evaluated for a range of Mach numbers for Oto 5. The effect of wall cooling and suction of the boundary layer on the …