Engineering Commons^™

A Transistor Delay Model Based On Charge Conservation, Bharatsingh K. Bisen

Theses

Delay information of a circuit is often used in the areas of timing verification, timing analysis, race detection and circuit optimization. Given a circuit its delay can be estimated by various simulation techniques. SPICE is one of the simulation techniques, but it is seen that with the increase in the complexity of the circuit the SPICE circuit simulation technique to obtain delay information become cumbersome and computationally too expensive. So as to overcome the above disadvantages of the circuit simulation technique to obtain delay information various timing delay models were developed. However general survey of most of these timing delay …

Biodegradation Of Hexachlorocyclohexane In Sand And Wastewater Using Immobilized Phanerochaete Chrysosporum, Ajaykumar C. Gami

Theses

The present study was carried out in order to assess the ability of Phanerochaete chysosporium to degrade lindane (hexachlorocyclohexane) in sand as well as in water. It was found that the fungus is immobilized on saw dust, it is able to degrade lindane in a packed-bed reactor configuration, with a first-order rate constant of 0.00066min^-1. The fungus is also able to degrade lindane in sand. As with the packed-bed reactor, a supplemental carbon source (glucose) is required. In this study it was found that a glucose concentration of 20 gm/kg of sand, and 40% w/w moisture content, give …

Preparation And Testing Of Novel Blocked Isocyanate Dental Adhesives Based Upon Hydroxyhexylmethacrylate, Yunwen Ye

Theses

A new kind of dental adhesive, O-Chlorophenol-TDI-HEMA-Pentaerythritol (TDI), was studied under long term conditions. The test was done in human third molar teeth which had been extracted 7 days to 6 months. Both citric acid and non citric acid pre-treatments were used on dentin surfaces. Based on Causton's[9] mineralizing solution pre-treatment method, we have used 3 kinds of mineralizing solutions, ITS, 0.5% CaCl2, NaF, as pre-treatment solutions. There were no significant differences between the citric acid and non citric acid pre-treatment. The ITS mineralizing solution pre-treatment caused a large increase in bond strength. The average bond strength of 1791 psi …

Estimating 3-D Motion And Structure Parameters Of A Rigid Planar Object By Establishing Landmark Correspondences, Herman Agustiawan

Theses

The application of a landmark based approach in recognizing 3-D rigid planar objects[3] along with two different motion and structure estimation algorithm [21][23] have been studied to perform motion and structure estimation tasks of moving objects. The recognition algorithm is based on a sphericity value derived from affine transformation that maps feature points in the object under observation from first to second view in the 2-D image space. The motion and structure estimation algorithm is based on a unique mapping given four or more feature point correspondences.

More than ten experiments have been done including small and large rigid motions. …

A Pc Based Computer Model With A Postprocessor For The Movement Of Groundwater, Joseph Byra

Theses

Currently available computer programs that model groundwater flow are inherently limited in their capabilities, in one way or another. Additionally, many of these computer programs are relatively inaccessible to the general user because they operate off of mainframe computers and sophisticated plotters. As a result, a simple to use computer program called 2DFLOW has been modified so it can be run on a personal IBM compatible computer. It models steady-state fluid flow through saturated porous media. In addition, a postprocessor called 2DPLOT has been developed. The postprocessor generates the equipotential contours and the flux vectors that describe the physics of …

Digital Correlators For Spread Spectrum Communications, Raymond B. Chadwick

Theses

The design and application, in spread spectrum communications, of a digital correlator implemented in a Xilinx Field Programmable Gate Array is presented. Spread spectrum communications, correlators and Xilinx Field Programmable Gate Arrays are first introduced. A digital correlator is designed and implemented in a Xilinx Field Programmable Gate Array. Cascading correlators to increase the correlation dimensions is next explored. The maximum operating frequency of the digital correlator is calculated and simulated to be 40 Mhz; a significant speed improvement over commercially available correlators such as those from TRW.

Recovering Surface Structure Using Direct Method, Zhu Ying

Theses

A new approach to recovering surface structure from a pair of stereo images is proposed in this thesis. The approach is based on an extension of the concept of optical flow to a spatial sequence of images. z.e., the unified optical field (DOFF). A direct method in spatial domain is developed which is able to recover surface structure that can be characterized by an Nth order polynomial equation. The order N of the surface can be one. a planar surface. or two, a cylindrical or spherical surface. for example. or any number higher than two. This is a big improvement …

Manufacturing Automation Protocol Implementation Guide, Richard H. Infantino

Theses

The purpose of this thesis is to provide a starting point for individuals seeking information on the Manufacturing Automation Protocol (MAP) Specification. This thesis is designed to be as comprehensive as possible, yet, still basic enough to be understood by an individual who may not be familiar with computers and networks, and how they function. The intent is to progress gradually from basic networking concepts and characteristics, to defining network requirements, and finally to network design and installation. At the conclusion of the paper is an Organized Method Approach to MAP network design and installation that could serve as a …

Slotted Aloha Protocol For Packet Transmission Via Satellite Link : Throughput Performance Of Continuous Transmission Packet, Solon Karashialis

Theses

The throughput performance of multi-access schemes for data traffic through a satellite channel is analyzed in this paper. Three general schemes are described: channel reservation schemes, random access schemes, and padket reservation schemes. This thesis considers only the random access schemes. Analysis and comparison between ALOHA and Slotted ALOHA are made, but the main emphasis is on satellite channel throughput. A continuous transmission protocol for Slotted ALOHA is suggested in which each ground earth station repeats the transmission of each packet in a number of random repetition slots. The channel is idle when no ground station (GS) is transmitting on …

The Dewaterability Of Anaerobically-Digested Sludges, Hui-Ching Lee

Theses

Vacuum filtration is the most common method used for sludge dewatering. Filtering or dewatering was operated to reduce the moisture content of the sludge after anaerobic digestion treatment.

The main purpose of this study is to determine the effect of the operating conditions of anaerobic digestion system on specific resistance in sludge filtration. The anaerobic sludges used for the present study were produced from the conventional single stage system and the multiple-stage system. From the experimental results, presently obtained that it is possible to compare the advantage and disadvantage of the two different digestion systems.

In addition, the effectiveness of …

Temperature Scale-Up On Rotating Biological Contactor Nitrification System, Kuanchun Lee

Theses

The relationship between RBC scale-up factor (SUF) and wastewater temperature is successfully developed by using Dr. Wu's mathematical model as a basis and 114 sets of data from the operation of 8 full-scale and 5 pilot-scale RBC plants served for NH3-N removal. The SUF obtained from this study is put into practice to present the scale-up of hydraulic loading for basic full-scale RBC plant design when the pilot study results are known and the design efficiency is fixed. An additional study is made to investigate two different RBC products manufactured by Autotrol Inc. and Lyco Inc. in terms of the …

Evaluation Of Rates Constants In An Isothermal Turbular Reactor, Yu-Hsin Lin

Theses

To view upon an incompressible laminar-flow fluid in fully developed in a plug reactor, in which a layer of catalyst coated on the inside surface of this reactor. Two kinds of reaction will occur : one is bulk ( homogeneous ) reaction, i.e., the reaction of reactants themselves; another is a first-order irreversible catalyst ( heterogeneous ) reaction, i.e., the reaction of reactants and catalysis.It is apparent that two reactipn rate constants, Κ_b for the homogeneous reaction and Κ_ω for the heterogeneous reaction, will be caused because of these two reactions

One partial differential equation after working of …

Study And Characterization Of Ingaas Photodiode And Photodiode Arrays, Krishna R. Linga

Theses

This thesis describes the InGaAs p-i-n photodiodes, photodiode arrays and their characterization. A work station was also built for the opto-electrical characterization. The main feature of the In,_zGa_iAs photodiodes with x > 0.53 is its response to higher wavelengths than the standard lattice-matched photodiodes. An In_xGa_1-xAs photodiode with x = 0.88 respond to 2.6 μm wavelength. The application of these photodiodes is forlIber optic communications, spectroscopy and instrumentation. A complete characterization and analysis of the In_0.88Ga_0.12As photodiodes is presented. Dark current analysis, which is a critical parameter in photodiodes, …

Optimization On Isdn In Multihop Radio Networks Through Genetic Algorithm, Prashant H. Pahade

Theses

Integrated service of voice and data on a single network has received considerable attention recently. Various techniques have been proposed and analysed for multiplexing voice and data over a large bandwidth channel. Efficient channel allocation for voice and data on multihop radio network is what we are most concerned about. In this paper, we address the problem of determining optimal access policies for a tandem ISDN network by using Genetic Algorithm. Computer Simulation shows that this leads to the decision which is beneficial to the services of both voice and data in the network.

Holographic Photo-Induced Electrochemical Etching Of Diffraction Grating In N-Inp, Pei-Chen Pien

Theses

Maskless laser-induced etching and plating is a novel technology for etching a three dimensional profile on semiconductor wafers. Using this technique, we may avoid the contaminating mask stage and achieve in-situ monitoring of the on-going process. In this thesis, we have presented findings on light diffraction from an etched pattern in a thin-film cell configuration. We suggest that the etched pattern develops mostly linearly in time with this arrangement, although indirect monitoring of the reaction process such as by light diffraction, should be carefully interpreted. In-situ light diffraction monitoring appear as if light was scattered from an etched pattern developed …

A Petri Net Simulation Tool, Ashish H. Shukla

Theses

A user friendly and highly interactive graphical tool for drawing, editing and simulating translated Petri Net models is developed. This SunView based tool allows simulation to be carried out in the 'step' and 'run' modes. In the 'run' mode it produces a log file of the simulation run which consists of: a) total number of tokens in the net; b) names of the transitions that fired; and c) the system state reached after each step's execution. The tool offers a new solution to the problem of modeling concurrent and interlocked systems, such as computer systems, modular software, flexible manufacturing systems …

Electrical Measurements Of Mos Structures Fabricated On Etched Silicon Surfaces, Venkata Ramana Vankayalapati

Theses

This thesis details the electrical characterization of thermally grown thin SiO₂ films on virgin and plasma etched silicon surfaces. The electrical characterization techniques employed for the present study are high frequency Capacitance Voltage(C-V) and Current-Voltage(I-V) measurements. The structures used in this study are Al/Polysilicon/SiO₂/Si/A1 capacitors fabricated on n-Si and p-Si substrates. These capacitors with areas in the range of 0.001-0.05 cm₂, were made using various plasma process conditions and etch reactors.

Based on the experimental results of the C-V anlaysis, in comparison of the controls samples with the plasma treated samples, we could not see …

Experimental Study On Filterability Of Leukocytes, Qi Wang

Theses

The filterability of leukocytes treated with A23187, Cytochalasin B, PAF and FMLP and pumped through 5 µm polycarbonate filters at a constant flow rate was examined. The concentration of the four agents was systematically varied. The filtration pressure was continuously recorded for data analysis. The pressure-time curves generally showed multiphasic components, following a small jump step at the beginning of the filtration process. The pressure rise was initially fast (initial faster increased phase, IP) and then rose more slowly (later slower increased phase, LP). The leukocytes treated with A23187 showed increased IP and higher LP values; those which were treated …

Electron Field Emission Through A Very Thin Oxide Layer, Guang Yang

Theses

Field Emission of an emitter covered with a very thin oxide layer is modeled and calculated numerically. The additional barrier due to the oxide layer is included in the tunnelling problem by using the standard WKB method and tunnelling transmission matrix method. The following physical parameters are considered: the oxide barrier height, the oxide conduction band edge electron effective mass, and the oxide dielectric constant. Compared with the Fowler-Nordheim equation, which was derived for a clean metallic emitter, the calculation of this work shows a reduction of the emission current density from an emitter covered with an oxide layer a …

Characterization Of Material Removal In The Course Of Abrasive Waterjet (Awj) Machining, Yu Yang

Theses

The objective of this study is to develop a practical procedure for prediction of the results of abrasive waterjet (AWJ) machining. The first stage of the study involves the development of the technique for prediction of the rate of material removal in the course of abrasive waterjet (AWJ) machining. A new parameter, Exergy Distribution Density (EDD), is introduced and used in order to characterize the cutting conditions. EDD, determined as the kinetic energy of particles delivered to a unit length of the generated surface, is the function of diameters of the sapphire nozzle (Dn) and the focusing tube (Dc), the …

Simulation Based Modeling And Scheduling Of A Generalized Flow- Line, Srinivas Anne

Theses

Simulation is a state of art technique, widely used to analyze the behavior of complex and dynamic real time systems. This study consists of two parts. The first part involves in the development of a simulation model of a real time flow line, used to assemble Printed Circuit Boards. The desired performance measures of the system, like, utilization, starving, blocking, failure and maintenance are recorded. The model developed can be used as a test pad to analyze scheduling rules and heuristics. This is illustrated in the second part of the study which consists of studying the behavior of the Apparent …

Design And Development Of Ccd Camera For Document Scanner Using Optical Fiber Bundle, Aniruddha P. Joshi

Theses

A CCD camera for the gray scale document line scanner has been designed and developed at Photon Imaging Corp. The scanner consists of a revolutionary optical fiber bundle, CCD camera, and control electronics. The key concept resides in the fiber-optic bundle. At one end it has a linear array of equally spaced light guides. These terminate at the opposite end in a square array with a polished surface for viewing by a camera. The fan-out from linear to square end is not done with attention to ordering, so the bundle may be relatively inexpensive. Reordering is done electronically using an …

Finite Element Analysis Of Torsional Concentric Composite Shaft Using Isoparametric Circular Element, Yee-Haur Wong

Theses

Finite Element Method is used to analyze the concentric composite material shaft subjected to torsion. Isoparametric circular ring element has been formulated to solve the one-dimensional problem. An intermaterial element at the interface has been developed to accomodate the changing modulus of rigidity.

Solutions of Prandtl's stress functions are used to compute shear stresses and torque in the composite shaft. Results of torque of the composite shaft are established using convergence tests of homogeneous solid and hollow shafts. Good agreement with classical solutions are obtained for homogeneous solid and hollow shafts.

A Torsional Concentric Composite Chart has been developed showing …

Wideband Microstrip Antenna Optimization, Amer Muhammad Alsawadi

Theses

An annular ring patch microstrip antenna was investigated numerically from the bandwidth aspect for a satellite link application. The desired portable antenna should occupy the physical volume of a typical briefcase and operate in the 400-500 MHz band. Numerical optimization is carried out using a commercially available computer package (EM, by Sonnet Software Inc.). The parameters optimized include the substrate thickness, feed location along the annular patch antenna and its relative dimensions. The software package was numerically validated for the rectangular patch geometries reported in the open literature. Experimental verification of this work is left to be carried out in …

A 512 X 512 Random Addressable Variable Resolution Image Sensor, Chakravarthy Yarlagadda

Theses

This thesis presents the design and layout of a 512 x 512-element with 20μm x 20μm pixels image sensor that emulates the properties of the human eye and is useful in high speed processing of visual data for machine vision applications. The imager will be able to operate with random-address selection in variable resolution or with multiple regions of interest to reduce the number of pixels readout. The selection of the pixels is done by x-y addressing the MOS switches which connect the photodiode pixel to the output through the sense lines. The design of column decoder and row decoder …

Photo-Induced Electrochemical Etching Of Inp Semiconductor In A Thin Film Cell, Bungsu Iskandar

Theses

The Photo-Induced Electrochemical Etching of n-InP wafer in aqueous solution is investigated for both reservoir and capillary systems. A sinusoidal spatial variation of light intensity pattern is directly illuminated and promoting etching on an InP semiconductor wafer. The etching process is time-efficient, and produces highly isotropical and a promising high resolution pattern. It gives a good reproducibility and has less contaminating features. Its features may be explained by a non-linear relationship between the electrolyte concentration and the photo-generated holes density at the interaction surface. An optimal reaction rate is determined by the ratio of the reactivity to ionic diffusion, either …

The Dynamics Of Bicycling : An Analytical And Experimental Investigation To Determine The Principles Of Design, Sylvester Yen

Theses

Bicycles have existed in working order for a century. They are mechanical products whose dynamic characteristics are highly nonlinear. This has to some extent prevented detailed analysis and for the most part design has been made from practical experience. The advent of computers has markedly changed the techniques and procedures used to calculate the performance of a bicycle. Bicycling began long ago, and since the first bicycle was demonstrated, bicyclists, scientists and engineers have designed thousands of different bicycles considering safety, comfort to ride and ease of control. Nonetheless, nobody claims to fully understand bicycling. If the fundamental principles exist, …

Rotary Micromotor Design With Ic-Compatible Processing, Hong Yu

Theses

Several microelectromechanical rotary motors have been designed and simulated with varying rotor and stator configurations. All of these micromotors operate with an electrostatic power source and have rotor diameters varying from 0.2 to 0.4 mm. These micromotors develop torques in the range 8 to 50 picoNewtons with rotors of polysilicon with 2 micron film thickness based on the detailed simulations of this thesis using a 3-phase voltage power source. The geometries modelled in this work are side-drive and vertical-drive configurations. These micromotors obtain drive torque from the fringe-field differential at the periphery of the rotor poles.

Unlevitated micromotors (with bearings) …

Modeling A Fuel Rich Premixed Laminar Methane Flame Oh, Ch, Nh, Cn Profiles, Including Prompt No, Md. Hasan Ul Karim

Theses

A detailed reaction mechanism based upon fundamental thermochemical kinetic principles has been developed to describe the concentration profiles of OH, CH, NH, CN, and NO including prompt NO radicals in laminar flow, fuel rich methane flames as well as flames doped with 700 ppm ammonia. A one dimensional laminar flat flame code which incorporated diffusion, and the detailed reaction mechanism was used to predict the radical concentration profiles from the model. These calculated values are compared to experimental data of Dean (1984).

The model consist of two reaction subsets, hydrocarbon oxidation set and an ammonia oxidation set. The reactions most …

Design Of A Cmos Temperature Sensor With Eeprom Error Correction Scheme, Jin-Ku Kang

Theses

This thesis describes the design and operation of a CMOS temperature sensor operating at very low power with an EEPROM error correction scheme including the physical layout. This device is designed for applications requiring very low power including biomedical and optically powered device applications. The sensor output is an analog voltage. The temperature sensing cell is implemented with two BJTs having different emitter areas. An op amp dissipating about 300 micro-watts power is designed and is used to amplify the sensor output voltage with a gain of 85dB. A novel EEPROM is used to correct nonlinearity error of the temperature …