Digital Commons Network^™

Investigation Of Material Erosion By Abrasive Water Jet Cutting, Fang Hu

Theses

This study is concerned with the investigation of material erosion phenomena occurring in the abrasive waterjet (AWJ) cutting process.

A series of scratches were generated by the abrasive waterjet on the polished surface of aluminum samples. The tests were carried out at different traverse speeds, abrasive flow rates, diameters of sapphire nozzles, diameters of carbide tubes and initial abrasive particle sizes. Material volume loss in the erosion zone was measured directly or calculated by the use of the suggested mathematical models. An analysis of experimental results enabled us to introduce a new process criterion, particle distribution density, which determines the …

Simulation Of Random Packing Of Hard Spheres Using Monte Carlo Method, Sung-Ho Park

Theses

A computer based method of generating a random packing of hard spheres is described. Using a Monte Carlo method as employed in the field of Computational Statistical Physics, packing of hard spheres are generated and analyzed.

The mean packing fractions for the present assemblies of 1000 spheres are 0.555±0.015 after pouring and 0.582±0.018 after 10 cycles of shaking. These values are approximately 5 to 6 per cent lower than the experimental results of G.D. Scott[30], but similar with the result of Visscher & Bolsterli [17].

The mean coordination numbers are 5.97 and 6.33 for the pouring and shaking case, respectively. …

Mathematical Modeling And Computer Simulations Of Biodenitrification In Batch And Sequencing Batch Reactors, Sugata Sanyal

Theses

Mathematical models have been derived for describing biodegradation of ni¬trate and nitrite in an anaerobic environment. Monod model for nitrate and Andrews model for nitrite were used as kinetic models. Experimental data from literature suggest that nitrate is not an inhibitory substance, while nitrite is not only inhibitory but it may also have a toxic effect on the biomass. The models were brought in dimensionless form in order to reduce the number of parame¬ters. Biodegradation was mathematically described for a batch, and a sequencing batch mode of operation. Computer programs were developed for numerically simulating the process. Some of the …

A Stereo Vision Technique Based On The Multi-Positioned Camera Criterion, Jie Bao

Theses

A modified feature based stereo vision [sic] technique is described in this thesis. The technique uses the curve-segments as the feature primitives in the matching process. The local characteristics of the curve-segments are extracted by the, Generalized Hough Transform.

A set of images of a scene, which are taken by a multi-positioned camera satisfying the parallelism criterion, are first filtered by the Laplacian of a Gaussian operator in different widths, i.e. coarse to fine channels. At each channel, the Generalized Hough Transform is applied to the curve-segments in each image. The curve position, the curve-length, the curve centroid, the average …

Token Bus Lan Performance : Modeling And Simulation, Ramesh Kurnool

Theses

A simulation model based on CSIM, a process oriented simulated language, to analyze the performance of the Token Bus protocol is developed. Performance measures such as throughput, average delay and maximum delay per packet are presented. System performance is analyzed for different loads, number of stations, network lengths, different physical and logical distribution of the stations with packet length as a parameter. Previous studies were based on the delay-throughput analysis with no discussion on the effect of variation of the logical and physical distribution of the stations on the performance of the model which is done in the present thesis. …

Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Service In The Token Ring Network, Darshakkumar J. Patel

Theses

In the token ring network different types of services gives different delay characteristics. Results to date have shown that in asymmetric traffic, exhaustive service gives more delay to lightly loaded stations where ordinary service wastes time in circulating the token after each transmission. In general, there is a need for more efficient service, which is compromised between ordinary and exhaustive service.

Ordinary and exhaustive service are analyzed in this thesis, and a new service, adaptive service, is proposed. By using timer and counter, adaptive service dynamically changes token holding time at the station. Different types of delay characteristics are derived …

The Oxidation Of Methylene Chloride Over Manganese Dioxide Catalyst, Jun Du

Theses

This research presents results from a study with the goal of using a transition metal oxidation catalyst, manganese dioxide (MnO₂) I to convert low concentrations of methylene chloride (CH₂Cl₂) in air and in a methane/air stream into CO₂, H₂O and HCl. Our objectives were to determine the oxidative effectiveness of the catalyst and its durability under the corrosive exposure to chlorine, HCl and other likely stack gas contaminants.

Experiments were carried out in a tubular packed bed integral reactor using gas chromatographic (FID and TCD) analysis for chlorocarbons and non-dispersive …

X-Ray Powder Diffraction, Scanning Electron Microscopy And Energy Dispersive Spectroscopy Studies Of Soil Containing Chromium Immobilized By Microwave Treatment, Nagui Ibrahim

Theses

The orientation of soil contaminants such as chromium is altered during microwave heating. The SEM and EDS were utilized in the study. The nature of the orientation is related to the heating time. This results in immobilizing the contaminant in leaching tests. The non-leachibility was related to the reactivity of the chromium salt with the soil hematite phase (Fe2O3) during the microwaving. This was proved By the X-ray diffraction analysis. The spectrums obtained from 30 and 60 minutes microwaved samples were identical in the crystal phases and were significantly different from the contaminated unheated sample.

Multiprocessor System Design Tutor : Expert System Approach, Rakesh Kamdar

Theses

To increase computational bandwidth and system resilience, integration of several microprocessors in a single system becomes necessary. The overall throughput and efficiency of such a system is directly dependent on the hardware and software interconnection supported by the basic microprocessor chip. Sometimes it becomes difficult to put together all the information for design criteria and all the design related formulas.

The approach made here is to continuously update the hardware and software information in the database related to a given microprocessor. This information can be accessed at any time for efficient design solution. Intel 80386 and Motorola 68020 microprocessors are …

Eeg Mapping Using The Personal Computer, Zhuan-Zhang Pei

Theses

An approach for brain electrical activity mapping using a personal computer has been investigated to enhance the visibility of the EECs. An automatic procedure from data acquisition to the final mapping has been developed for on-line or off-line data processing, in which a table-look-up technique has been introduced to eliminate redundant processing. The power spectra in different EEC frequency bands for four electrodes are coded into 15 colors and mapped on a color monitor. The data correspondings to the areas between electrodes are interpolated by the surface spline method. The mapping speed and smoothness has been optimized. An experiment has …

A Study Of The Effects Of Weighting Matrices In Power System State Estimation, Yanshi Wang

Theses

The effects of weighting matrices that may be used in the Weighted Least Squares (WLS) method when applied to the problem of Power System State Estimation (PSSE) are studied. These weighting matrices include the one usually used in the literature and the one used in the utility PSSE programs

The performances of these weighting matrices are compared using the Monte Carlo simulation technique.

To test the performances of the weighting matrices, a PSSE program is developed, different performance indices for state comparison are defined, and many cases are studied.

Results show that the weighting matrix usually used in literature, 1/σ², …

Trends Of Metals (Pb, Zn, Cd, Cr, Mn, Fe, Hg And Ni) Concentration In The New Jersey Air Environment, Shobha R. Boddu

Theses

The atmospheric concentrations and relative trends of ten trace elements (Co, Cd, Fe, Hg, Pb, Ni, Zn, Cu, Cr and Mn) were studied at Elizabeth and Carteret, New Jersey from July 1987 to September 1989. The specific sites are Industrial and Residential Interface areas. The analytical procedure involved collection of the airborne particulates on a quartz microfiber filter using a high volume sampler. The samples were digested and then analyzed using the atomic absorption spectrometer. Elizabeth usually showed lower values for the metals than Carteret. Average concentrations (ng/m3) for the respective metals over the entire project are: Metal: Co Cd …

Mathematical Modeling And Simulation Of The Progression Of Aids, Anju H. Nagpal

Theses

Acquired Immunodeficiency Syndrome (AIDS) caused by Human Immunodeficiency Virus (HIV) is a pernicious disease acknowledged as a world health problem. One of the major issues in the study of AIDS is understanding the manifestation and the progression of the disease following the transmission of HIV. Unfortunately, the present state of biological knowledge does not yet give us a reliable means of evaluating these phenomena. A simulation approach is, therefore, extremely useful in predicting the various phases of the deteriorating physiological status of the patient. In the present study we have focused on the development of a mathematical model of the …

Design Of A Real Time Optical Sensor For Continuous Blood Cell Separation, Girish S. Yerande

Theses

For continuous measurement and display of oxygen saturation and RBC content in blood during cell separation a reflection type optical sensor is designed based on the theoretical model using the photon diffusion theory. The prototype sensor consists of two arrays of light emitting diodes, red and infrared, and photodiodes. The emission wavelength of LEDs are 660 nm and 800 nm. The 800 rim which is in the infrared region is very close to isobestic value for blood. The prototype sensor is mounted on the blood cell separator equipped with an antitwister mechanism. Each LED emits a specific wavelength of light …

Biodegradation Of Polymers And Isolation And Crude Characterization Of Proteins From These Studies, Sunil S. Godbole

Theses

The performance of immobilized and free microorganisms in the biodegradation of polymers was investigated using a recirculation flow reactor and an air-sparged reactor respectively. The bio-oxidation ability of these microbes towards polyamide emulsion was studied.

Extracellular protein cuts isolated were checked for oxidative activity in a microassay reactor. These fractions were compared from various biodegradation studies.

Microassay tests and monitoring of the oxygen consumption in recirculation flow confirmed substrate dependent oxygen consumption, polyamide being provided as the sole carbon source. Increases in extracellular protein buildup were a positive indication of biodegradation.

The protein cut greater than 500,000 daltons was found …

Biodegradation Of Phenol By Two Competing Microbial Species In A Sequencing Batch Reactor, Yoo-Suk Ko

Theses

Biodegradation of a single pollutant by two competing microbial species has been mathematically described for the case where a sequencing batch reactor is used. The model has been solved numerically to predict the behavior of the reactor under different operating conditions and for different kinetic expressions for biodegradation.

Experiments were performed to verify the predictions of the model. Serratia marcescens (ATCC 17991) and Pseudomonas putida (ATCC 31800) were the species used. Experiments were first performed in order to reveal the kinetics of biodegradation for each individual species. The biodegradable substance used was phenol, which was the sole carbon source in …

Impacts Of Treated Municipal Waste-Waters On Development And Growth Of Hudson-Raritan Estuary Fishes, Chien-Min Chen

Theses

The Hudson—Raritan Estuary, known as one of the worst polluted estuaries in the world, receives pollutants from many point sources. Treated municipal wastewater (TMW) counts for 13% of its total freshwater input and more than 98% of the chemicals classified as priority pollutants been infused. Because of the complexity of the input, treatment facilities cannot remove toxicants efficiently. In addition, generation of new compounds by water treatment such as chlorination occurs. Batch-to-batch variability in the chemistry of this effluent was reflected in the early life stage toxicity bioassays using mummichog (Fundulus heteroclitus) and winter flounder (Pseudopleuronectes americanus) embryos.

TMW has …

Thermal Desorption Of Hazardous And Toxic Organic Compounds From Sand Matrices, Jaeil Kwon

Theses

Incineration processes are effective and sometimes efficient technologies for the remediation of contaminated solids which result in permanent destruction of most organic hazardous compounds. A less energy intensive, but more efficient process to remove contaminants from the soil is the application of heat and a flow of inert gas where the entire soil mass is not heated to incineration temperatures. This thermal treatment increases volatilization and often effects complete removal of organic compound depending on soil conditions and species volatility,

The goals of this research are to develop an understanding of the mass transport phenomena and adsorption thermodynamics that control …

A Comparison Of Integrated And Differential Estimates Of Flourescent Intensity Profiles Using Digital Video Image Analysis, Langfang Wu

Theses

The dynamics of macromolecular transport across microvascular walls in the hamster cheek pouch have previously been studied by other investigators using fluorescence intravital microscopy. Fluorescein Isothiocyanate labeled Dextrans (FITC-Dx) of 20,000, and 70,000 molecular weight (FITC-Dx-20 and FITC- Dx-70) were used as macromolecular probes. Values of fluorescent intensity were previously recorded on videotape as a function of distance perpendicular to leaking vessels over a period of about 2.5 hr to allow for tracer equilibration in the interstitial space. In this study, these videotapes were played back frame-by-frame and 215x130-pixel windows around each leaking vessel were selected for further analysis of …

Multiphase Solid-Liquid-Liquid Mixing In Stirred Tanks, George R. Deritter

Theses

A large number of investigations can be found in the literature which examine the effect of mixing parameters in both solid-liquid and liquid-liquid systems. However, very little is currently available for solid-liquid-liquid systems. It is the intent of this study to look at the various parameters affecting the point of complete dispersion for a liquid and the point of complete suspension for a solid phase, in a three phase liquid-liquid-solid system.

Interconnection Of X.25 Networks, Syed Ayaz Qutubuddin Ahmed

Theses

The purpose of this work was to investigate the performance of two interconnected X.25 networks via CCITT internet protocol X.75. Since internet protocol X.75 follow the same flow approach as X.25, we are allowed to model the acknowledgement queue in such a way that this queue provides a feed back path from destination to the source queue. Thus we are able to model our interconnected network as a closed queueing network with limited number of packets in transit within the network. Mean Value Analysis with Blocking (MVA) algorithm was applied to obtain the performance characteristics as the resources available were …

The Accreditation Of Professional-Technician Occupations, Michael William Allgaier

Theses

This study investigates the relevance of different elements of accreditation as applied to professional and technical occupations. The impact of essential elements of typical accreditation programs on the outcome of the credentialing process is studied. The credentialing process is viewed in the context of how it affects the public safety, health and well being of society. The health, legal, engineering, and educational professions are analyzed to form a conventional professional base of comparison with the emerging professional-technical occupations in the nuclear industry, especially nondestructive examiners.

Nurses, attorneys, engineers, and teachers accreditation programs are analyzed for their strengths and areas for …

An Implementation Of Mht Algorithm For Adaptive Transform Coding Of Speech, Peter Battenschlag

Theses

The Modified Hermite Transform (MHT), a suboptimum block transform scheme, is implemented on a TMS320C25 signal processing system with the objective of reducing the redundancy in speech signals and transmit a quantized vector representation at bitrates as less as 0.5 bits per sample.

The generation of the Hermite polynomials with a binomial and several first order IIR filter structures is presented focusing on the fact that no muliplications are required which simplifies the MHT algorithm considerably.

An assembler program performs forward and inverse transformation together with a vector quantization using adaptive bitallocation based on short-time statistics for the transform coefficients. …

Removal Of Nitric Oxide From Flue Gas With Ferrous Cysteine Solutions, Chun-Chiao Chou

Theses

The removal of NO from flue gas with aqueous ferrous cysteine solution as the reducing agent was discovered by S. G. Chang et al. (1988), at University of California, Berkeley. The purpose of this research is to extend the experimental works done by Chang et al., and to find methods to minimize the problems associated with the sensitivity of the medium to oxygen gas and emission of nitrous oxide, a greenhouse gas. The main objective was to determine the feasibility of using ferrous cysteine in the treatment of NOx emissions from incinerators. In the present study, it was found that …

The Role Of Multinational Corporations In Nigeria : A Case Study, Eteng Bassey Eno

Theses

Multinational corporations in Nigeria are as old as Nigeria itself. This section has been recognized as an important area of economic activity which is capable of having both positive as well as negative economic implications regarding employment, technology transfer, international capital investments and other sociocultural issues in Nigeria. In Nigeria multinationals corporations (MNC) have virtually dominated such industries as cement, beer brewing, tobacco products, soap and cosmetics, chemicals, pharmaceutical, machinery, electric equipment and assembly activities ie. motor vehicle and bicycle. However, much as the host country is aware of the inherent danger posed by direct investment by transnational corporations, the …

A Code Verification System For Ink Jet Printing, Daniel Liang Hsu

Theses

This paper describes system integration of a code verification system. The system utilizes a feature matching

Cryogenic Characterization Of Potential High Temperature Superconducter Substrates At Microwave Frequencies, Sukhmani Kaur

Theses

The lack of characterization data for dielectric substrate materials at microwave frequencies and cryogenic temperatures hinders the development of high T_c superconducting circuits. Low loss (tanδ < 10^-4) substrates with dielectric constants in the range of 5-100 at cryogenic temperatures are needed to realize the advantages of superconductor circuits. Measurement techniques previously reported are either time consuming or inaccurate. We report an adaptation of Courtney's method for accurate, simple evaluation of complex dielectric constants (10 < ε_r < 100) at low temperatures. The fixture was calibrated using known properties of polycrystalline ZrSnTiO4. We measured er and tans on three potential substrate materials, Al₂O₃, MgO, and LaAlO₃ at 5-10 GHz in the temperature range 77-300K. No temperature hysteresis in either ε_{r …}

Design Of Spatial Linkages For Dwell Function Generation, Donald F. Kelly

Theses

Certain single-loop spatial linkages containing spherical pairs may be used as dwell function generators. Analysis and design of these linkages, however, may be too complex for the practicing engineer.

In this study a method is presented, where the set of link lengths representing a linkage are determined from a smaller set of design parameters. Graphical relationships are also found between the design parameters and functional requirements for dwell, such as output function amplitude and dwell range. These graphs may be used as design charts, and design becomes the calculation of link lengths from design parameters chosen to satisfy the functional …

Chemical Degradation Of Pcp And Polychlorophenols, Kon-Tsu Kin

Theses

There are generally two ways of removing PCP and polychlorophenols from the environment: biodegradation and photodecomposition. However, no convenient way has yet been available to destroy PCP wastes which exist in a concentrated form which may result from some cases of emergency spills. In this thesis, a chemical oxidation procedure is proposed for the destruction of PCP and polychlorophenols.

In a water medium and in the presence of base and oxidant, the PCP and model polychlorophenols destruction percentage obtained is higher than 99.8%. Sodium hydroxide (NaOH) and calcium hydroxide (Ca(OH)₂) are utilized as the bases, and sodium hypochlorite …

Optimum Power System Planning, Youn Tae Kyong

Theses

This thesis presents analysis method of optimum power system planning. The Gauss-Seidel iteration method is used to calculate load flow data of power system. The real and reactive powers, voltage magnitude and phase angle at each bus were obtained using Gauss-Seidel iteration method for a given IEEE sample power system. The load flow calculations were repeated under 60 percentage, 70 percentage, 80 percentage, 90 percentage, 100 percentage loading condition.

The transformation of reference frames were performed to simplify given IEEE sample power system identification. The transformation of reference frame transforms real and reactive voltage, current and impedance variables(reference frame 1) …