Engineering Commons^™

Dynamic Behavior Of Boiling Water Reactors, Jose March-Leuba

Doctoral Dissertations

A study of the basic processes involved in boiling water nuclear reactor dynamics is presented. The main emphasis of this research has been placed on the physical interpretation of these processes. It is shown that this type of reactors have two regimes of operation: linear, during normal operation, and nonlinear, if they become unstable due to the thermohydraulic feedback. Both of these regimes are studied using low-order physical models.

The main result obtained from the linear study is the pole-zero configuration of the reactivity-to-power transfer function. It is determined that three zeros and four poles are needed to properly represent …

Application Of Combined Jointed Media And Discrete Slip Plane Characteristics To Subsidence Predictions, David W. Basinger

Theses and Dissertations

This thesis presents an application of a numerical formulation incorporating the effects of joints, cracks, and fractures to a soil subsidence predictions problem, and the extension of that formulation to combined discrete slip planes and jointed media continua formulations. The results obtained are compared to each other and to a physical centrifuge simulation performed previously on the same problem.

Solution To Eigenvalue Problems Of Antisymmetric Cross-Ply And Antisymmetric Angle-Ply Laminated Plates Using Affine Transformations, Zaffir A. Chaudry

Theses and Dissertations

Using affine transformations and suitably recasting the buckling vibration differential equations, the eigenvalue problem of anti-symmetric cross-ply and antisymmetric angle-ply laminated rectangular plates has been reduced to a function of two strong material constants, the generalized rigidity ratio, whose range is in the closed interval from 0 to 1, and the ratio of principal lamina stiffness. With the reduction in number of constants an exhaustive parameter study of buckling and vibration solution trends, is possible. The buckling coefficients decrease with decreasing value of generalized rigidity ratio for both antisymmetric cross-ply and antisymmetric angle-ply laminates. For a given aspect ratio, and …

Study Of Longitudinal Landing Flying Qualities Evaluation Using Pilot Model Theory, Eric D. Didomenico

Theses and Dissertations

Control Anticipation Parameter (CAP), used in MIL-SPEC-8785C as a longitudinal handling qualities criterion does not adequately distinguish between different flight phases. Recent flight test data from the Landing Approach Higher Order Systems (LAHOS) study further indicate the inadequacy of the second order approximations for higher order longitudinal landing flying qualities. Nine Aircraft that fall within the Level 1 boundary reveal pilot ratings ranging from 1.5 to 10 (Cooper/Harper). These nine aircraft are studied by combining their longitudinal dynamics with pilot modelling to examine a better method of landing flying quality prediction and evaluation. Pilot model theory (cross-over pilot model) is …

Mathematical Simulation Of Proteins Separation In A Packed Bed, Jing James Huang

Dissertations

The generalized adsorption models are developed to simulate the unsteady state mass transfer behavior in a packed column. Based on the nature of adsorbent particles, the adsorption models may be classified into two categories: (1) the surface adsorption model, (2) the pore diffusion model. In the first model, it is assumed that the internal diffusion is negligible, and the adsorption rate is determined by external diffusion and surface adsorption. In the second model, the effect of internal diffusion is considered as significant as that of external diffusion. For both models, the effect of axial dispersion in fluid phase is emphasized. …

Mathematical Modeling Of Carrier Mediated Mass Transfer Through Liquid Membrane Systems, Keng Chao Wang

Dissertations

Dispersed liquid membrane systems are double emulsion drops. Two immiscible phases are separated by a third phase which is immiscible with the other two phases. The liquid membrane systems were classified into three types: (1) carrier mediated mass transfer, (2) mass transfer with reaction in the receiving phase, (3) mass transfer without any reaction involved. Copper extraction, phenol removal and solvent extraction were used as typical examples for each type of the membrane systems in the derivation of their mathematical models. Models with or without the consideration of film resistances were developed and compared. The models developed in this study …

The Biodegradation Of Phenol And O-Chlorophenol Using Activated Sludge Bacteria, Jeffery Colish

Theses

The biological degradation of phenol up to 500 ppm and 0-chlorophenol up to 40 ppm was studied in an aerated 4.0 liter hatch reactor using activated sludge bacteria from the Livingston, N.J. wastewater treatment plant. From the concentration versus time data, kinetic rate constants were determined for phenol (@ 100 ppm) and o-chlorophenol (@ 20 ppm and 40 ppm). Air stripping was determined to be an insignificant removal mechanism for the compounds studied.

It was noted that the acclimation times decreased with repeated exposure to a particular concentration of phenol or o-chlorophenol, and that the activated sludge bacteria first had …

An Experimental Investigation Of The Kinetics And Thermal Properties Of Poly(Ethylene) Terephthalate And Its Related Di-Acid Modified Copolymers, Satish Baliga

Theses

Poly(ethylene) Terephthalate , PET, is synthesized from purified Bis-hydroxyethyl Terephthalate,(BHET), in the presence of antimony oxide catalyst. Rate constant for the polycondensation reaction, based on a second order kinetic model is found to be 152.4/mol/hr.

A new modified polyester Polyethylene Adipic Terephthalate (PEAT) is synthesized from BHET and adipic acid. The effect of adipic acid content in the copolymer,on the rate of polycondensation is studied. Adipic acid is shown to improve the activity of the polymer chain ends thereby increasing the apparent reaction rate constants.

The modified polyesters are observed to melt at a lower temperature than PET. Moreover, the …

Stability Of Bicomponet Polymeric Liquids In Poiseuille Flow, Chin-Chang Jeng

Theses

Polymer processing, involving two or more components, has become more popular recently in industrial plants. However, product Quality is affected very much by the fluid stability. Some theoretical and experimental results concerning Newtonian and non-Newtonian flow in rectangular coordinates, have been published, and the fluid-fluid interfaces were observed to be unstable by some researchers.

In this paper, the linear stability of bicomponent non-Newtonian fluids flowing in a cylindrical tube was investigated by using the Ellis model. Only the very long wave and the axisymmetric disturbances were considered. The Ellis zero-shear-rate viscosity ratio, m( = η02 / η01 )destabilizing. The half-zero-shear-rate-viscosity …

A Comparison Of The Biodegradation Of Nitrobenzene, 1-Butanol, And 2,4-Dichlorphenoxyacetic Acid Using A Municipal Mixed Liquor And Three Commercial Bacterial Preparations, Salvatore P. Salerno

Theses

The biological degradation of nitrobenzene, 1-butanol, and 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in aerated 6 liter batch reactors using activated sludge from the Livingston, NJ wastewater treatment plant-- by itself and in a 10:1 by volume mixture with each of three commercial bacterial preparations: Hydrobac, BI-CHEM DC-1006/7, and Liquid Live Microorganisms (LLMO). Air stripping and adsorption were determined to be insignificant removal mechanisms for the three compounds studied. None of the bacterial mixtures were able to degrade 10 ppm nitrobenzene to any significant extent. A small but noticeable improvement in degradation rates occurred when the Livingston sludge was mixed with …

X-Ray Fluorescence Spectroscopic Analysis Of Coal Ash, George Patrick Watson

Theses

Several coal ashes and prepared mixtures were analyzed by x-ray fluorescence spectroscopy. Various techniques were studied to determine the most reliable procedure for quantitatively estimating, from fluorescent peak intensities, the concentrations of seven major oxides typically present in the ash. These ashes were analyzed with only minimal sample preparation. In order to determine the self-consistency of the procedure, several mixtures of known composition were prepared containing the major elements present in an ash.

Because of inter-element absorption and enhancement effects, several computational techniques were used to calculate composition from spectrum peak intensities. The method that yielded the most accurate estimates …

Synthesis Of Trimethylpropane-Tolylene-2,4-Diisocyanate Adduct And Its Blocked Monomers, Farhad Forohar

Theses

A trimethylolpropane adduct of tolylene-2,4-diisocyanate (TMP-TDI) was prepared by reaction in a heterogeneous solvent system. The isocyanate functional groups of the TMP-TDI adduct were blocked with the following blocking agents: p-cresol, eugenol, o-chlorophenol, and one to one mole ratio of mixtures of 2-hydroxyethyl methacrylate (HEMA) and each of the three preceding blocking agents. A sample of TMP-TDI adduct blocked with only HEMA was also prepared. The products were characterized by melting point, infrared spectroscopy, and elemental analysis. Monomers of TMP-TDI blocked with 50% HEMA and 50% blocking agents may be very useful as dental restorative materials.

Microbial Characteristics Of An Activated Sludge And Three Commercial Preparations After Exposure To Phenolics, Laurie Gneiding

Theses

The biological characteristics of four microbial mixtures were examined after successive exposure to phenol and 2-chlorophenol at room temperature. One of the microbial mixtures was an activated sludge from the Livingston, NJ municipal wastewater treatment plant. The other three mixtures were commercial preparations sold by Polybac Corp.(Hydrobac), Sybron Corp. (BI-CHEM DC 1006/1007), and General Environmental Sciences(LLMO).

The characteristics examined were relative counts and species of gram negative/gram positive bacteria, yeast and fungi, protozoa, and higher organisms. For the gram negative bacteria and yeasts, culturing techniques and diagnostic tubes were used to determine the predominant species. Biochemical tests were done on …

Homogenous Reaction Kinetics Of Reduction Of Sulfur Dioxide, Satyanarayana Manthani

Theses

Homogeneous reduction of sulfur dioxide by carbon monoxide was investigated in the temperature range between 700 and 1000°C, initial sulfur dioxide concentration of about 3000 ppm, typical of a flue gas from coal fired power plants, and excess carbon monoxide concentration, in a 12 mm O.D. quartz tubular reactor. Over ninty percent reduction of sulfur dioxide was obtained at temperatures above 900°C and space times of the order of about 3.5 seconds. Substantial carbonyl sulfide was also produced.

Measurement Of Air Force Fire Department Productivity: An Evaluation Of Efficiency/Effectiveness, Timothy A. Byers, Susanne M. Waylette

Theses and Dissertations

This research was sponsored to develop a method of evaluating the productivity of Air Force Fire Departments. Using the tasks developed by the Fire Department Workshop, input and output measures were defined and used in a new model of efficiency called Constrained Facet Analysis (CFA). The advantage of this methodology over others considered was that it can simultaneously evaluate multiple inputs and multiple outputs using empirical data with no a priori weighting. The results of the analysis provided an efficiency rating for each fire department and information about marginal rates of substitution and marginal rates of productivity for inefficient units …

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, …

Modeling Of A Combined Cycle Mhd/Steam Power Plant, Edward H. Kiessling Iii

Masters Theses

The objective of this effort was to develop an improved process model of a prototype MHD/steam central station power plant. This model was designed to perform a first law thermodynamic analysis for steady state plant operation. An existing MHD topping cycle model was modified to provide predictions of mass flows and energy requirements associated with topping cycle equipment for coal processing and oxidant preparation. This topping cycle is characterized by full slag carryover to the heat and seed recovery system. PRESTO II, a program for analyzing the performance of regenerative, superheated steam-turbine cycles, was added to the existing model structure …

Analysis Of A Ground-Coupled Heat Pump During A Heating Season, Francis Conlin

Masters Theses

A ground-coupled heat pump, installed in an 170 square meter residential building in Knox County Tennessee, has been examined both experimentally and analytically. The ground coupling was realized with a 210 meter coil buried 1.2 meters beneath the soil, through which circulated a secondary heat transfer fluid. The house, the ground and the power consuming devices were instrumented, and hourly readings of temperatures, heat flows, power consumption, and weather data were recorded.

The experiment was carried out during the 1982-1983 heating season beginning in November and lasting 26 weeks. The overall heating seasonal performance factor was 2.57. No backup heat …

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.

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

Archived Theses and Dissertations

No abstract provided.

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 …

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 …

The Weldability Of Cr-Mo Steels For Fossil Energy Applications, Mark W. Richey

Masters Theses

This research program was undertaken to provide fundamental and basic metallurgical information on the behavior of the heat-affect zone (HAZ) in Cr-Mo steel welds, as well as practical information on their relative weldability. The principal work was the evaluation of the stress-relief cracking (SRC) and hydrogen-assisted cracking (HAC) susceptibility of Cr-Mo steels ranging in Cr content from 2 1/4%-12%. Differences in observed cracking behavior were contrasted with differences in composition, on-cooling transformation behavior and weld microstructure.

The test methods were varied to investigate the effect of preheat, post-weld heat treatment (PWHT) , metallurgical structure and restraint (externally applied) on the …

Performance Of A Ground-Coupled Heat Pump During A Cooling Season, Steven D. Wix

Masters Theses

A ground-coupled heat pump system was installed in TECH House I at the Tennessee Energy Conservation in Housing site located on the University of Tennessee campus. The performance of the heat pump system was evaluated for the cooling season of 1983. Data on system energy flows, power consumption, house temperatures, soil temperatures and weather conditions were gathered on an hourly basis for the entire cooling season. Weekly coefficients of performance, soil thermal conductivitys, and a seasonal performance factor were calculated from experimental data.

The performance was found to be poor when compared to a conventional air-to-air heat pump system. The …

A Wear Minimization Design Investigation Of Feedline Splitters, Turning Sections, And Feed Nozzles Of A Pneumatic Conveyed Solids System, Warren R. Gilbert Jr.

Masters Theses

The adverse effects of wear has continually plagued the operation of the TVA 20 MW Atmospheric Fluidized Bed Combustion Pilot Plant. Wear has caused serious problems in all aspects of the pneumatically fed below-bed coal feed system. This has given rise to the development of high wear resistant designs of feedline splitters, turning sections, and feed nozzles.

Wear testing of PVC feedline system components was conducted at The University of Tennessee to determine the wear characteristics of different designs. PVC was chosen for the feedline system component material to accelerate the wear testing results. A series of similar tests were …

The Role Of Molecular Weight In Controlling The Structure And Properties Of High-Speed Melt Spun Nylon-6 Filaments, Jogendra Suryadevara

Masters Theses

A comprehensive study of the structure development during high speed melt spinning of nylon-6 was performed. The major emphasis of the research was on the effect of molecular weight in the structure development of high speed melt spun nylon-6 filaments. The various measurements done on the filaments to determine their morphology included diameter, tensions in spin-line, density as well as x-ray diffraction and birefringence measurements. The effects of mass throughputs were also studied. Tensile properties of conditioned fibers were measured and related to the spinning variables and molecular weight.

The spin-line stresses measured increased rapidly with take-up velocity and molecular …

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. …