Engineering Commons^™

Mixing Effect On Chemical Reaction In Liquid Phase, Ming-Teh Hsu

Dissertations

Mathematical models for the mixing phenomenon are proposed in this study. First model deals Newtonian and non-Newtonian fluid without chemical reaction. The new terminology " degree of mixing " is define in this model for the time-dependency of mixing toward its completeness. The velocity profile and boundary conditions are given, then the degree of mixing can be calculated by the mathematical model. The degree of mixing is influenced by fluid motion and it is function of time.

Second model deals with first-order reaction effected by mixing. A mean fractional conversion is defined to investigate the rate of bhemical reaction. Results …

A Study Of The Effect Of Solids, Viscosity, And Basestock On The Development Of Blade Coated Paper Properties, Steven D. Bennett

Masters Theses

A review of literature relating coating solids to coated paper properties revealed many contradictions. Little was found relating coating viscosity to coated paper property development. A statistically designed study was conducted to evaluate the importance of solids, viscosity, and basestock on the development of blade coated paper properties. Temperature was used to control coating viscosity independently of solids. Clay-latex and calcium carbonate-latex coatings were applied to groundwood containing basestocks using a Flooded Nip blade coater. Multiple linear regression models were generated for each of the coated paper properties. Solids and basestock were most important in the models for gloss, smoothness, …

Simulation Of Particle Size Distribution In Continuous Emulsion Polymerization Through A Modified Population Balance Approach, Ying-Yuh Lu

Theses

A detailed mathematical model for particle size distribution in continuous emulsion polymerization of styrene and vinyl acetate is proposed on the basis of the population balance in the presence of several kinetic and mass transfer processes. This study is limited to the Smith-Ewart case II, which assumes instantaneous free radical termination within polymer particles. Radical desorption mechanism from polymer particles is included in the model and the desorption rate is formulated from the diffusion theory which suggests that the rate coefficient should be inversely proportional to the surface area of polymer particles.

Selection Of Sludge Conditioning Chemicals And Filter Media For Vacuum Filter Dewatering Of Sludge At The Atlantic Wastewater Treatment Plant, Douglas W. Fredericks

Civil & Environmental Engineering Theses & Dissertations

A literature review was conducted to determine the types of vacuum filter systems available for sludge dewatering, the characteristics of wastewater sludge which are important to dewatering, and the methods of sludge conditioning for vacuum filtration which are available. Capillary suction time and Buchner funnel tests were performed to determine the dewatering characteristics of sludge conditioned with ferric chloride and lime, polymer, polymer and lime, and polymer and incinerator ash. Filter leaf tests were performed to determine filter cake release characteristics of various conditioned sludge and the performance characteristics of several filter media. It was determined that ferric chloride and …

Suboptimal Algorithms For Improvement Of Pipeline Through Insertion Of Delays, Sukhamoy Som

Electrical & Computer Engineering Theses & Dissertations

Pipelining is now widely used in the design of high speed processors in order to overcome the intrinsic speed limitations imposed by the technology. For a good performance and avoidance of internal conflicts, the concurrent operations within different subunits of a pipeline architecture should be properly scheduled This scheduling problem is known to be intrinsically difficult" and a member of the "NP complete class of problems. The aim of this thesis is to develop heuristic suboptimal algorithms whose execution time is a polynomial function of the number of items to be scheduled. Insertion of delay is used as a basic …

An Experimental And Analytical Investigation Of Friction Factors For Fully Developed Flow In Internally Finned Triangular Ducts, Hoshang Chegini

Mechanical & Aerospace Engineering Theses & Dissertations

Friction factors for fully-developed flow in triangular ducts with fins of various sizes are investigated for Reynolds numbers ranging from 150 to 90,000. Two triangular ducts having apex angles of 60 and 38.8 degrees are studied. Results are presented in the form of standard plots of friction factor as a function of Reynolds number. Friction factor values for the smooth triangular-duct cases are in good agreement with the existing results. For the finned-duct cases, the fully developed axial-velocity profiles in laminar flow are determined by solving the x-momentum equation iteratively by the Gauss-Seidel finite difference technique. The theoretically determined friction …

A 250-Kv Two-Pulse Modulator For The Gas Flow Switch Test Facility, David Michael Barrett

Electrical & Computer Engineering Theses & Dissertations

High-pressure spark gap switches are often used in pulsed power systems because of their high power capabilities. Unfortunately, these switches cannot be operated at high repetition rates because of the time required for the switch to recover. However, the recovery rate of a spark gap may be improved by flowing a gas through the interelectrode region so as to remove the hot gases and debris.

A test facility has been designed and constructed at Old Dominion University to evaluate the performance of gas-flow spark gap switches operating over a wide range of voltages and flow parameters. The facility consists of …

Block Encoding Of Speech Spectral Principal Components, James R. Holland Jr.

Electrical & Computer Engineering Theses & Dissertations

A Karhunen-Loeve series expansion was used to block encode speech spectral principal components as a function of time. Each of ten principal components was first obtained as a linear combination of 2© speech spectral band energies. Using a fixed block length of 10 frames (0.128 s), the K-L basis vectors were computed separately for various speakers for each principal component. In all cases the resulting basis vectors were essentially a set of discrete cosine basis vectors. Synthesis of speech from the block encoded parameters showed that very little information is lost with up to 70% data reduction. The block encoding …

An Experimental And Analytical Investigation Of The Iosipescu Shear Test For Composite Materials, Barry Stuart Spigel

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanical properties of composite materials under shear loading are difficult to determine. The Iosipescu Shear test, originally proposed for metals, has in recent years been applied to composites. It has the advantages of small specimen size, simple loading and a reasonably uniform shear stress in the test section.

The purpose of this work is to study the validity of the Iosipescu test method for measuring the shear modulus and shear strength of composites. Finite element analyses indicate that optimum specimen geometry and load locations depend upon the degree of orthotropy of the composite. Test results for a quasi-isotropic graphite/epoxy laminate …

Implementation Of Uniform Perturbation Method For Potential Flow Past Axisymmetric And Two-Dimensional Bodies, Tin Chee Wong

Mechanical & Aerospace Engineering Theses & Dissertations

The aerodynamic characteristics of potential flow past an axisymmetric slender body and a thin airfoil are calculated by using a uniform perturbation analysis method. The method is based on the superposition of potentials of point singularities distributed inside the body. The strength distribution satisfies a linear integral equation by enforcing the flow tangency condition on the surface of the body. The complete uniform asymptotic expansion of its solution is obtained with respect to the slenderness ratio by modifying and adapting an existing technique. Results calculated by the perturbation analysis method are compared with the existing surface-singularity-panel method and some available …

X-Ray Diffraction Studies Of Amorphous Silicon, Adel Gabra I Gouda

Archived Theses and Dissertations

No abstract provided.

Combined Forced And Free Convection In The Trombe Wall Channel, Jim Ginchaun Huang

Mechanical & Aerospace Engineering Theses & Dissertations

A vertical channel connected by horizontal exit and entrance segments is simulated and represents a flow passage for a Trombe wall solar collector. The two-dimensional combined forced and free convection mode is investigated for the laminar regime. The vertical walls of the channel are maintained at a constant but different temperature while horizontal walls are insulated. A finite difference method using up-wind differencing for the non-linear convective terms and central differencing for the second order derivatives is employed to solve the governing differential equations for mass, momentum, and energy balances. The solution is obtained for stream function, vorticity, and temperature …

Studies On The Interference Of Wings And Propeller Slipstreams, Ramadas K. Prabhu

Mechanical & Aerospace Engineering Theses & Dissertations

The small disturbance potential flow theory is applied to determine the lift of an airfoil in a nonuniform parallel stream. The given stream is replaced by an equivalent stream with a certain number of velocity discontinuities, and the influence of these discontinuities is obtained by the method of images. Next, this method is extended to the problem of an airfoil in a nonuniform stream of smooth velocity profile. This model allows perturbation velocity potential in a rotational undisturbed stream. A comparison of these results with numerical solutions of Euler equations indicates that, although approximate, the present method provides useful information …

Mathematical Modeling Of Unsteady State Photo-Polymerization, Rong-Fa Liang

Dissertations

Mathematical modeling of unsteady state photopolymerization in an isothermal batch reactor has been investigated. An analytical solution of the distribution of active polymers as a function of reaction time has been determined. It is verified that the quasi-stationary state approximation is valid in the photopolymerization process.

The free radical polymerization of styrene is forced periodically by on-off UV light regulation to the reactor. The effect of operating condition, the ratio of light-off period to light on/off period, on the polydispersity and molecular weight distribution are theoretically and numerically investigated. Significant broadening on molecular weight distribution can be obtained during the …

The Effects Of Pressure On The Kinetics And Mechanisms Of The Bod Reaction, Peter Sereico

Dissertations

The research was concerned with the kinetics and mechanisms of BOD reduction due to pressurization. The initial investigations involved attempts to reproduce and interpret the results of previous investigators. Thereafter, actual wastewater samples were pressurized and changes in the wastewater characteristics were analyzed and recorded. Based on the findings, possible mechanisms for creating the changes noted were proposed.

To test the mechanisms considered, samples of pure compounds were prepared and pressurized. The results of this analysis eliminated all of the mechanisms but the actual one. The mechanism responsible for changes in BOD profile under pressure conditions is the hydrolysis of …

Mathematical Modeling Of Distillation Operation From Non-Equilibrium Approach, Wen-Dow Pan

Dissertations

A new method for mathematical modeling of a distillation operation from non-equilibrium approach has been studied. The primary purpose of the study was to develop a model to simulate the mechanism of mass transfer between a continuous phase and the bubbles of a dispersed phase in a distillation column. The second major purpose of this work was to utilize and test the model of estimating the tray efficiency.

Distillation was considered to be purely a mass transfer process, where the less volatile component is transferred from vapor to liquid phase, and the more volatile component from liquid to vapor phase. …

Use Of An Optical Probe To Measure Bubble Characteristics In Gas Fluidized Beds, Thomas Tai-Pai Chu

Dissertations

A novel optical probe has been developed and used for on-line monitoring of the bubble characteristics in a three-dimensional gas fluidized bed. The probe sensor has a major dimension of 1.8 cm, and contains an LED and a photo-cell separated by a gap of 2.5 mm. Coupled with a non-inverting comparator circuit with hysteresis as a noise filter, the probe has been very effective in characterizing the size distribution, shape and velocity of gas bubbles.

A 96 liter rectangular fluidized bed was used, containing glass beads with a size fraction of 355μ to 250μ. Air was the fluidizing medium, with …

Determination Of Systemic Blood Pressure Via Autospectral Analysis Of Oscillometric Data, Eugene Elie Warner

Dissertations and Theses

The currently accepted methods for measuring systemic blood pressure are either highly accurate but invasive in nature or clinically convenient but prone to observer-related errors. A new oscillometric method uses sensitive signal conditioning and sensing equipment with a non-invasive arm cuff to record arterial pulsations. The goal of this study is to establish more reliable criteria for the identification of systolic and diastolic pressures from oscillometric data.

Successful Management Techniques For Introduction Of Computerized Systems In A Production Facility, Michael James Boyle

Theses

This thesis surveys the potential for introducing significant organizational change into a manufacturing environment which is undergoing large scale capital improvement.

The first portion describes both the organizational and technological barriers present at a specific manufacturing facility. The capabilities of a computer based process control system are detailed along with its ability to fulfill the employer's particular business needs.

The next portion details the work necessary to train both management and production operators, not only on how to use this computer based equipment, but also how they themselves must change their personal modes of thinking in order to carry out …

Performance Modeling And Simulation Of Multiple Microcomputer Systems, Moorthy Narayana Hariharan

Theses

Multiple processor systems are the logical choice for applications demanding high computing power, throughput and reliability. Moderately coupled Multiple Microprocessor systems can be applied to a variety of applications demanding high performance. The structure of Multiple Microprocessor systems is examined. Various interconnection structures are analysed for performance comparisons.

Queueing theory is a powerful tool in modeling and analysing Computer systems. Queueing models are developed for popular Multiple processor interconnection topolog es like the Shared memory, Shared bus, Star and Loop configurations.

The usefulness of Digital computer Simulation techniques in estimating the performance of Multiple processor systems is demonstrated through a …

Computer Analysis Of The Stefan Problem In Cryosurgery, Dong Hyuk Kim

Theses

Numerical solutions for determining the freezing front location vs time relation in cryosurgery are obtained by utilizing the heat transfer computer program TRUMP, which employs the explicit finite difference algorithm. The probe geometries of rectangular, cylindrical, and spherical shape with one dimensional heat flow are selected for study. Internal heat generation is considered in cylindrical and sphe¬rical probe geometries, and the difference between the solutions with and without heat generation is discussed. To verify the correctness of the TRUMP solution, comparisons are made in the freezing distance vs time relation with the Neumann's solution and the implicit enthalpy method for …

Reliability Studies On Solid Tantalum Electrolytic Capacitors, Hamed Nassar

Theses

The primary objective of this thesis is to determine and analyze the failure mechanisms of solid tantalum capacitors, pinpoint the causes, and suggest the precautionary measures that prevent the occurrence of these failures. To achieve this goal, the study went in two directions, theoretical and experimental. The theoretical part-is a comprehensive review of the work -done on tantalum capacitors since 1960 up to date.

The experimental part of the study is a life test (1000 hours) of solid tantalum capacitors under humidity and high temperature. To avoid the misconception that could happen by investigating a particular manufacturer's product, units from …

Calibration Of Flame Ionization Detector For Chlorinated Hydrocarbons, Nahid Jabalameli

Theses

Relative Responses and Calibration Factors were developed for several volatile organic (mostly chlorinated) priority pollutant species in order to use one single stable compound (e.g.Benzene) for daily instrument calibration. This would replace the procedure of using a standard mixture of target compounds (25-35). This is of particular advantage because the standard mixture may not have all species stable or may show loss of some components relative to others due to wall adsorption in the standard (compressed gas) stainless steel cylinder.

The use of a single standard species was made possible by developing "accurate" relative response and calibration factors of all …

A Study Of Worker Motivation, Farid Uddin Ahmad

Theses

This thesis mainly deals with the motivation of the production managers, engineers, technicians and production workers. The purpose is to emphasize the need for providing due motivations to an important work group of the industry who are largely ignored. An attempt has been made to amply demonstrate the various techniques for worker motivation. As the study of standard motivational theories alone cannot solve the complex motivational problems, all possible efforts have been made to relate, integrate and blend the theories with actual applications in the organizations. All the relevant and important issues connected with worker motivation have been highlighted. Points …

Energy And Economic Analysis Of Alternate Total Energy Systems, Swaminathan Balakrishnan

Theses

The purpose of this study is to evaluate the Performance of Diesel engines, gas engines, and gas turbines when used in a Total Energy System. To begin with, the history of cogeneration was studied, current literature and texts reviewed and companies which deal with these engines or turbines were contacted. Electricity and gas tariffs were obtained from the P.S.E.&G. Co. It was decided to consider an apartment complex of approximately 200,000 ft² having peak heating and cooling loads of approximately 4.92 million Btu/hr and 2.93 million Btu/hr respectively for this analysis. The average electrical demand was 520 KW. Next …

Volatile Organic Pollutant Levels In Indoor Environments From The Use Of Kerosene Heaters, Kashinath Banerjee

Theses

The indoor air pollutant levels caused by use of kerosene stoves as sources of heat in residences is of increasing concern as the use of such heaters becomes more widespread. Emission of volatile organic. species (aliphatic hydrocarbons from hexane to dodecane, cyclohexane and aromatic species including benzene, toluene, ethyl benzene, m/p xylenes, o-xylene and styrene) from these devices were measured at different sites. The organic vapor samples have been collected by adsorption on Tenax GC, and quantitatively analyzed by thermal desorption into a high Resolution capillary column gas chromatograph. Mass spectral analysis was also conducted for qualitative identification of sample …

The Application Of The Finite Element Method To Plate Stress Analysis, Yao-Zong Jen

Theses

The finite element formulation of plane elasticity and plate bending is presented and is employed in the development of the formulation of element stiffness equations and structural stiffness equations. The basic relations used to derive the finite element equations for a solid continuum are also presented. The programming organization is summarized.

The computer program cited from TAYLOR has been used to solve the deep beam problem with triangular and rectangular elements and the SAP IV program has been used to solve the plate bending problems with quadrilateral elements. Problems solved are: (1) stress distribution at the midspan of a simply …

Implementing A Preventive Maintenance Program In A Pharmaceutical Manufacturing Plant, Daniel J. Shatynski

Theses

The goal of Preventive Maintenance is to reduce operating costs through greater equipment availability and lower downtime costs. Its intention is also to reduce the frequency and severity of corrective maintenance. A case study of a chemical manufacturing plant in the pharmaceutical industry is reviewer and symptoms are illustrated for purposes of definition. The development and implementation of a Preventive Maintenance program for this chemical manufacturing plant is proposed.

Analysis Of Selected Volatile Organic Substances Associated With Residential Kerosene Heater Use And The Health Implications, Catherine Coombs Bobenhausen

Theses

Volatile organic species (aliphatic hydrocarbons from hexane to dodecane, cyclohexane and aromatic species including benzene, toluene, ethyl benzene, m,p, and o—xylenes, nitrobenzene, styrene and naphthalene) associated with residential kerosene heater emissions were measured at two sites. One was a small room having a total volume of 23.66 cubic meters and an air change rate of 2.71 air changes per hour, and the other, a living/dining room area having a combined volume of 79.30 cubic meters and an estimated air change rate of .7 air changes per hour. The analytical procedure involved collection of a series of air samples in stainless …

Deposition Of Suspension In Inclined Channels Due To The Effects Of Inertia, Gravity And Image Force, I-Hsi Chu

Theses

This investigation was made to determine the effect on the deposition of particle in an inclined parallel-plate channel due to the influences of image charge, viscosity, inertia and gravity. The flow considered was lamina, imcompressible and steady. The flow patterns considered were uniform and fully developed with symmetry about the axis of the channel.

The governing equations derived for a particle were based on Newton's Second Law of motion. Since the resulting governing equations are linear second order differential equations, Runge-Kutta algorithm is used to solve the problem and graphical techniques is used to interpret the results of the numerical …