Engineering Commons^™

Adsorption Of Organic Compounds By Microbial Biomass, Ariamalar Selvakumar

Dissertations

The adsorption of hazardous organic compounds such as phenol, 2-chlorophenol, 2-nitrophenol, chlorobenzene, and ethylbenzene onto two types of inactive microbial biomass (activated sludge and nitrifying bacteria) was studied. The adsorption isotherms could be expressed by the Freundlich adsorption isotherm and were found to be nearly linear over the range of concentrations (50 - 200 mg/1) studied. Desorption studies showed that the adsorption process was partially reversible. Heat of sorption was estimated and indicate that the biosorption process involves a physical rather than a chemical mechanism. The adsorptive capacity of biomass is about two to three orders of magnitude less than …

Implementing Ray Tracing Algorithm In Parallel Environment, Tjah Jadi

Dissertations and Theses

Ray tracing is a very popular rendering algorithm in the field of computer graphics because it can generate highly-realistic images from three-dimensional models. Unfortunately, the computational cost is very expensive. To speed up the rendering process we present both static and dynamic scheduling (balancing) strategies for a multiprocessor system. Hence, the load balancing among the processors is the most important problem in parallel processing. The implementation of the algorithm is based on a modified octree structure.

A Dynamic Model Of Fill-And-Draw Reactor Utilizing An Inhibitory Substrate, Yun-Fei Ko

Theses

A dynamic model of a fill-and-draw reactor has been developed, which includes a number of operational parameters, the fraction of total cycle time devoted to fill, reaction and draw, and the concentration of the toxic substance in the feed to the reactor.

Operating diagrams have been generated, from which one can choose suitable operating parameters.

The model has been solved numerically for Andrews kinetics ( substrate inhibition ), and tested experimentally, using a 5-liter fill-and-draw reactor with phenol as sole carbon source and a pure culture of Pseudomonas putida. Results compared very well to the model predictions.

A Cmos Circuit Generator Using Differential Pass Transistors For Implementing Boolean Functions, Rabe'eh Mahooti

Dissertations and Theses

This study uses differential pass transistor methodology for implementing and evaluating Boolean functions. The main goal is investigation of CMOS and nMOS approaches in pass transistor logic design. Pass-transistor logic is most effective in the implementation of Boolean functions when the vectors are in the same format. It has been demonstrated that nMOS pass transistor logic driven by a control signal voltage above the V_dd level offers a significant improvement in speed. nMOS pass transistorsalso offer less area consumption in comparison to the CMOS approach.

The philosophy developed here has been used in the design of a program for …

On A Taylor Weak Statement For Finite Element Computations In Gas Dynamics, Jin Whan Kim

Doctoral Dissertations

The Taylor Weak Statement has been developed as a potential unified approach for approximate computation of fluid flows. It is verified to contain a variety of numerical dissipative methods developed for advection problems by specific identification of its expansion parameters. Generalized Fourier modal analysis has been completed in one space dimension for both semi-and fully-discrete approximations, from which the flux limiter method is herein developed and evaluated for finite element computations. Its application to 1- and 2-dimensional scalar models is investigated for continuous and discontinuous initial value problems, and its use for the Euler equation system of gas dynamics in …

Limitation Of Sulfur Dioxide Removal In A Fgd Spray Dryer Using Once Through Slaked Lime, Sambamurty Raju Dantuluri

Doctoral Dissertations

The present study discusses the importance of slaking operation and its effect on the removal efficiency in a spray dryer operated FGD system using slaked lime slurry. Laboratory scale slaking experiments were run to look into various characteristics of resulting slurry. Pilot plant tests were made to quantify the effects of different parameters on spray removal efficiency. A vertical tower mill was used to grind calcium hydroxide slurry to attain smaller particle size. X-ray diffraction and SEM techniques were used to visualize the crystallinity and surface aspects of calcium hydroxide slurry. Sorbent particle size and surface area measurements were made …

A Volume Integral Formulation For Electromagnetic Scattering From Homogeneous Dielectric Bodies, Mark Joseph Povinelli

Electrical Engineering and Computer Science – Theses

In recent years, printed circuit antennas have become very useful in conformal and planar phased array antenna systems. Of particular interest is the radiation and scattering performance of stripline and microstrip printed circuit antenna array-elements used in these systems. These ele­ments are generally made up of a complex three-dimensional distribution of dielectrics and con­ductors, which can include microstrip or stripline feed circuitry on a dielectric substrate. Figure 1 shows the geometry of a typical multilayer printed circuit stripline-fed flared slot antenna, used as an array-element in a multioctave planar phased array antenna. This antenna element design also incorporates a stripline …

Energy Considerations In Stock Preparation Refining Modified By Recycling, Rajendra D. Deshpande

Masters Theses

Experiments were conducted to study the effect of refining on virgin fibers as well as on recycled fibers. Interaction effects of recycling and type of treatment of virgin fibers on characteristics of secondary fiber were studied. A significant reduction in drainage properties of the furnish for both hardwood and softwood pulps were observed. This reduction in properties was found proportional to the amount of refining. It is necessary to achieve required strength properties at higher freeness values, if fibers are to be recycled. This can be done by improvement in uniformity or homogeneity of refining and by gentler and less …

Effects Of Coefficient Errors On The Performance Predictions Of A Typical Fighter At Medium Altitude, John D. Cloyd

Masters Theses

Performance prediction is one of the primary uses of wind tunnel data. Uncertainties in the tunnel data are therefore directly related to errors in performance predictions. The objective of this study was to examine the effects of aerodynamic coefficient errors on the point performance predictions for a typical fighter at medium altitude and subsonic velocity. The point performance parameters were formulated as functions of the aerodynamic coefficients. A computer program was written to calculate the selected performance parameters for 121 cases, each case representing a different combination of coefficient errors. The result was the correlation of the percentage error in …

Gas-Phase Reactions Of Methylene Chloride And Methylene Chloride-Trichloroethylene Mixture With Methane In Tubular Flow Reactor And Atmospheric Pressure, Javad Tavakoli-Attar

Dissertations

Reactions of methylene chloride diluted in methane and Argon and a mixture of methylene chloride + trichloroethylene diluted in methane and argon are studied in three flow reactors of different surface to volume ratios 4, 10.5, and 16 mm ID , atmospheric pressure and over a temperature range of 750-1000 °C. Experiments were conducted isothermally, ±5 °C over central 80% of oven length using a three zone oven. Argon was added as a diluent in order to limit carbon (s) formation. The concentration ratios of methylene chloride/methane/argon and methylene chloride/trichloroethylene/methane/argon was held constant at 1:4:10 and 1:1:40:40 respectively, throughout the …

Determination Of Aromatic Amines By Diazonium Salt, Hong-Hue Hsu

Theses

There are many analytical methods used in the identification of aniline by the production of various colors upon treatment with certain reagents. In this work a new inexpensive, easy and sensitive methods to quantitate aniline is developed. The change of absorbance is large enough to measure with a difference of only 1 ppm in the aniline concentration.

In this method, the reagent (2,4-dinitrodiazonium sulphate) which reacts with aniline produces a yellow color. Formation of this color (which absorbs at 486 nm) indicates the presence of aniline. The amount of aniline can be determined by measuring the absorbance at 486 nm. …

High-Energy, Curable Polycyclopentadiene Binder For Solid Rocket Propellants, Jian Guo Ning

Theses

Diels Alder polymerization of cyclopentadiene ( CPD ) has been carried out at 170°C under inert atmosphere. The resulted polymer has a low bulk viscosity, 7.4 cps, and a number average molecular weight M_n up to 3000. This liquid Prepolymer is curable with maleic anhydride. With ammonium perchlorate, aluminum, and maleic anhydride, a high energy solid propellant has been formulated with this polymer. Via bomb calorimeter, Instron, and density measurement, it was found that this propellant has a better heat of combustion, tensile strength, and solid loading than that of the commercial rocket propellant based on hydroxyl terminated polybutadiene.

Formation Of Light Hydrocarbons And Soot In The Pyrolysis Reactions Of Chloro, Dichlorobenzene, Acetylene And Benzene In An Atmosphere Of Hydrogen, Larry Jiyuan Zhu

Theses

The kinetics of thermal decomposition of chlorobenzene and dichlorobenzene in a hydrogen and helium atmosphere were further studied to investigate formation of soot and light hydrocarbons. The experiments were performed at atmosphere pressure with residence times rangeing from 0.2 to 1.2 seconds, and the temperature ranges of 850°C to 925°C for chlorobenzene and 870°C to 910°C for dichlorobenzene. Flame ionization detectors, which were connected to GC columns, were utilized for the qualitative and quantitative analysis of the reaction products. A methyl silicone capillary column was used analyzing of heavy aromatics and a Carbosive G was used to analyze light hydrocarbons. …

A Study On The Poly(Ethylene Terephthalate)/Flouropolymer Blends, Chyan-Nin Chiu

Theses

The rate of crystallization of Polyethylene terephthalate) (PET) can be improved by blending it with polyethylene co chlorotrifluoroethylene) (ECTFE; tradename Halar) so that it can be suitable for injection molding. The special advantage of this method is that molecular weight of the blend will not decrease so much as by adding nucleating agents. That is to say, the mechanical strength of the blend will not decrease very much compared with that of virgin PET.

The Effects Of Low Doses (1 To 500 Kilograys) Of 100-Kev Electrons On Four Polymers, Cynthia Anne Bradbury

Physics Theses & Dissertations

Commercial films of polyetherimide (PEI), polyetheretherimide (PEEI), polyethylene terephthalate (PET), and polycarbonate (PC) were exposed in vacuum to l 00-keV electron radiation to total absorbed doses of l, l 0, l 00, 300, and 500 kilograys. The concentration of radiation-generated radicals, as measured by electron paramagnetic resonance (EPR), increased by over an order of magnitude in all four polymers. Correspondingly, the intensity of the infrared absorption peaks increased uniformly for all doses. Solubility tests resulted in decreased solubility in all polymers. IR, EPR, and solubility suggest dehydrogenation of the aliphatic C-H and phenyl C-H sites. The data indicated that cross …

Reactions Of Diketones With Phosphorous Ylides, Amal Mohamed Lakany

Archived Theses and Dissertations

No abstract provided.

Viscous Shock Layer Analysis Of Hypersonic Flows Over Long Slender Vehicles, Kam-Pui Lee

Mechanical & Aerospace Engineering Theses & Dissertations

A method for solving the viscous shock-layer equations for hypersonic flows over long slender bodies is presented. The governing equations are solved by employing a spatial-marching implicit finite-difference technique. The two first-order equations, continuity and normal momentum, are solved simultaneously as a coupled set. This method yields a simple and computationally efficient technique.

Flows past hyperboloids and sphere cones with body half angles of five to 35 degrees are considered. The flow conditions included are from high Reynolds numbers at low altitudes to low Reynolds numbers at high altitudes. Detailed comparisons have been made with other predictions and experimental data …

Application Of Advanced Grid Generation Techniques For Flow Field Computations About Complex Configurations, Monchai Kathong

Mechanical & Aerospace Engineering Theses & Dissertations

In the computation of flow fields about complex configurations, it is very difficult to construct a boundary-fitted coordinate system. An alternative approach is to use several grids at once, each of which is generated independently. This procedure is called the "multiple grids" or "zonal grids" approach, and its applications are investigated in this study. The method is a conservative approach and provides conservation of fluxes at grid interfaces. The Euler equations are solved numerically on such grids for various configurations. The numerical scheme used is the finite-volume technique with a three-stage Runge-Kutta time integration. The code is vectorized and programmed …

A Finite Element Formulation For The Large Deflection Random Response Of Thermally Buckled Structures, James Eugene Locke

Mechanical & Aerospace Engineering Theses & Dissertations

The effects of temperature and acoustic loading are included in a theoretical finite element large deflection formulation for thin, isotropic plate and beam type structures. Thermal loads are applied as steady-state temperature distributions, and acoustic loads are taken to be stationary and Gaussian with zero mean and uniform magnitude and phase over the surface of the structure. Material properties are considered to be independent of temperature. Also, inplane and rotary inertia terms are assumed to be neglegible, and all inplane edge conditions are taken to be immovable. For the random vibration analysis, cross correlation terms are included.

The nature of …

Numerical Simulation Of Turbulent Flows Past Three-Dimensional Cavities, Shivakumar Srinivasan

Mechanical & Aerospace Engineering Theses & Dissertations

Computations have been performed to simulate turbulent supersonic, transonic, and subsonic flows past three-dimensional deep, transitional, and shallow cavities. Simulation of these self sustained oscillatory flows has been generated through time accurate solutions of Reynolds averaged full Navier-Stokes equations using the explicit MacCormack scheme. The Reynolds stresses have been modeled, using the Baldwin-Lomax algebraic turbulence model with certain modifications. The computational results include instantaneous and time averaged flow properties everywhere in the computational domain. Time series analyses have been performed for the instantaneous pressure values on the cavity floor. Comparison with experimental data is made in terms of the mean …

The Relationship Of Pore Volume And Pore Size Distribution To The Development Of Gloss And Scattering Coefficient, John A. Cook

Masters Theses

This study describes in a quantitative manner the relationships between coating structure and optical properties. Gloss, scattering coefficient and void volume were measured after applying different blends of polystyrene spheres to mylar film. Each coating was modeled using large spherical particles of the same size ratios to measure pore size distribution. The coating structure followed well with theoretical packing characteristics of spheres. Optical properties were related to changes in coating structure. Scattering coefficient and gloss correlated better with pore size distribution than particle size. Gloss increased when total void volume was reduced, while the scattering coefficient decreased.

Reactor Design For Hazardous Waste Treatment Using A White Rot Fungus, Daewon Pak

Dissertations

Various nutrient media and reactor configurations have been explored in order to grow the white rot fungus Phanerochaete chrysosporium, induce its active enzyme, develop kinetic data for the degradation of 2-chlorophenol, and use chemical engineering analysis to design an efficient reactor.

Preliminary experiments indicated that the biodegradation rate was improved by two to three orders of magnitude when the fungus was immobilized. As a result, emphasis shifted to two types of reactor design: a packed-bed reactor employing a silica-based porous support, and a fluidized-bed reactor employing alginate beads. Both were very effective in degrading 2 chlorophenol at inlet concentrations up …

Assessment Of Autonomic Regulation Of Heart Rate Variability, Shaw-Jyh Shin

Dissertations

Complex demodulation, accompanied by the techniques of interpolation, detrending and zero-phase-shift lowpass filtering were used to examine the effect of both divisions of the autonomic nervous system (sympathetic and parasympathetic) on heart rate by analyzing the heart rate variability signal from dogs under two different classical conditionings: CS+ and CS-, which cause different dynamic pattern changes in the autonomic nervous system to regulate the heart rate.

Unlike power spectral analysis, complex demodulation gives results in the time domain and shows the variation of amplitude and phase over time at a given frequency. The variation of phase indicates the frequency deviation …

Multiyear Drought Simulation With Periodic-Stochastic Hydrologic Processes, Lankeswara Hemal Wijayaratne

Dissertations

Previous studies on multiyear droughts are often limited to the analysis of historic annual flow series. A major problem in these studies is the unavailability of long historic flow records, on which to perform the analysis. To overcome this difficulty, the present study has used synthetically generated mean annual flow series to suppliment the historic flows. For the purpose of generating flows, a general methodology was developed to propose a mathematical model based on the harmonic and stochastic analyses of the historic flow series. The main objective was to derive a large population of multiyear drought events from the generated …

Sorption And Desorption Of Organic Compounds By Flyash, Kashinath Banerjee

Dissertations

A sorbent treatment process has been developed which uses flyash as sorbent in the treatment of highly toxic and hazardous chemicals; these include: Alcohols, Aldehydes, Ketones and Aromatics. Batch, as well as dynamic, studies were performed, in different phases, during the investigation. Single and multiple solute systems were examined separately. The samples were analyzed using a Flame Ionization Detector Gas Chromatograph.

The result of this study demonstrates that isolation/ immobilization of the organic pollutants is technologically feasible by adsorbing the contaminants onto flyash. The residual carbon content of the flyash plays a very significant role during the treatment process. The …

Use Of Recirculation Reactor To Study Biodegradation Of 2-Chlorophenol, Kai-Chung Yang

Theses

The performance of immobilized cells in the treatment of hazardous waste was investigated using a recirculation flow reactor run in a batch mode. A mixed microbial population from a municipal wastewater treatment plant was immobilized in calcium alginate gel. The bio-oxidation ability of these microbes towards a model toxin (2-chlorophenol) was studied. The process parameters studied were as follows:

1. Flow rate of the recycle stream;
2. Biomass loading;
3. Spiking concentration of 2-chlorophenol;
4. Use of buffered vs. non-buffered defined medium.

Dissolved oxygen concentration was monitored using a flow Clark-type dissolved oxygen probe. Oxygen consumption was correlated with the biodegradation of 2-chlorophenol. Physical …

A Silicon Photodiode Array For Soft X-Ray Sensing, Chih-Te Hu

Theses

An array of 30 x 30 sensing cells including logic within each cell and a self-scan address circuit are described. A unique scintillation technique is used to increase the threshold sensitivity 60dB for X-ray photon sensing beyond that obtainable with conventional photodiode sensors. Simulations for the sensing cell and some additional logic elements are based on SPICE version 2G5 and HILO 3. Worst case analysis includes variations in threshold voltage V_TP and V_TN for the CMOS circuit components. The final CMOS chip dimension using MOSIS 1.2 micron rules is 10mm x 10mm base on the 80 …

Softening Response Of Concrete In Direct Tension, Teresa Cintora

Theses

Due to the increased attention in nonlinear fracture mechanics and numerical methods of cementitious material, it has become necessary to have a reliable investigation of the post-peak softening response of concrete under direct uniaxial loading. But due to the brittleness of the material previous researchers have encountered great difficulty in obtaining complete data regarding the load-deformation behavior. This study uses a strain-controlled testing method and therefore the post-peak curve can be more easily obtained. Based on these results a unique formula for the normalized load vs. deformation curve has been proposed to be applied in fracture analysis applications.

On Conventional And Harmonic Load Flow Analysis, Ranjit B. Pradhan

Theses

In conventional power flow analysis, simultaneous linear equations numbering in thousands must be solved repeatedly and in many instances on-line. Luckily the matrix of coefficients of these equations is sparse with a few elements in each row. Therefore for a faster solution and to save computer memory, sparsity must be exploited and an optimal ordering of the equations must be sought. When considering harmonics, the number of the simultaneous equations to be solved is multiplied and therefore, considering sparsity and optimal ordering is doubly important.

In this thesis a software package for optimizing computation time and memory requirements through exploitation …

System Performance Criteria In Cdma Networks Using Gold Codes, Yong H. Kim

Theses

First, we have presented the autocorrelation and crosscorrelation properties for periodic and aperiodic binary sequences. The generation of binary sequences using shift registers with feedback was reviewed. We have also included correlation properties for the Gold codes.

Next, we discussed Gold code generation for the balanced and unbalanced Gold codes.

Thirdly, we investigated the number of simultaneous users in a CDMA system using Gold codes for the worst case and the average case of mutual interference.

Finally, we simulated the probability of interference exceeding a threshold value, and the average crosscorrelation value caused by interference in a CDMA network which …