Engineering Commons^™

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.

Adaptive Stack Filtering By Lms And Perceptron Learning, Yu-Chou Huang

Theses

Stack filters are a class of sliding?window nonlinear digital filters that possess the weak superposition property(threshold decomposition) and the ordering property known as the stacking property. They have been demonstrated to be robust in suppressing noise. Two methods are introduced in this thesis to adaptively configure a stack filter. One is by employing the Least Mean Square(LMS) algorithm and the other is based on Perceptron learning.

Experimental results are presented to demonstrate the effectiveness of our methods to noise suppression.

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 …

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 …

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 …

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 …

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 …

Monolithic Induction-Sourced Ac-To-Dc Power Supply Design, Jianhua Chen

Theses

This thesis describes techniques with design nomographs for supplying power to CMOS and microelectromechanical implanted devices. These applications require voltages in the range of 5 to 50 volts. Different kinds of voltage multiplier circuits were used to achieve high voltage output. The AC-to-DC and DC-to-DC capacitive bootstrap voltage multipliers are designed and analyzed. The AC-to-DC and DC-to-DC inductive bootstrap voltage multiplier circuits are presented and the SPICE simulations are done with those circuits. Four different options of inductive link high voltage power supply are presented, analyzed and compared. The link parameters of two VLSI-compatible square-shaped coils are calculated in both …

Implementation Of Parallel Sorting Algorithms On A Transputer Network, Venkatraman U. Calidas

Theses

Many sorting algorithms, such as the bubble sort and the binary tree selection sort, are n-squared algorithms and take O (n2) time to sort n values. These can be easily parallelized; the resulting sorts are called the odd-even transposition sort and the parallel tree selection sort, respectively. These have O(nlogn) time complexity. The quicksort is an O(nlogn) algorithm and it can parallelized to make it an O(logn) algorithm.

A transputer is a microprocessor which has serial links to transmit and receive data from other transputers. The above algorithms are implemented on a network of transputers and the link connections for …

Recycling: Separation Of Major Thermoplastics From Postconsumer Plastics Stream, Rafael A. Rodriguez

Theses

The complete process for separating Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), Polyvinyl Chloride (PVC), Polypropylene (PP), Polystyrene (PS), Polyurethane (PU), and Polyethylene Terephthalate (PET) from a mixture of postconsumer plastics materials was presented. The driving forces considered to achieve separation were different densities and selective solubility of plastics in specific solvents.

The proposed process separates Polyurethane and Polystyrene by using aqueous solutions of different densities. On the other hand, the other five plastics are separated using solvents.

Diagrams showing streams and plastics separation in each unit were discussed. Individual material balances for each step were performed for a …

Point Pattern Matching By A Genetic Algroithm, Minghwang Chen

Theses

The problem we consider is to find a subset of points in a pattern that best match to a subset of points in another pattern through a transformation in a least squares sense. Exhaustive search to find the best assignment mapping one set of points to another set is, if the number of points that are to be matched is large, computationally expensive. We develop a genetic algorithm which searches for the best ("almost the best") assignment efficiently. To map the point pattern matching into the framework of a genetic algorithm, we use a fitness function which inversely proportional to …

Comparative Analysis Of Single And Double Dwell Acquisition Schemes, Gurinder Singh Ahluwalia

Theses

Single and double dwell pseudonoise (PN) acquisition systems are described, explained and analyzed. These systems are designed to synchronize a locally generated PN signal with a received PN signal of unknown phase in the presence of noise. The mean, variance and an approximate probability distribution function (PDF) of the acquisition time for the single and double dwell PN acquisition schemes is developed. Intuitively, the double dwell acquisition system should be superior to the single dwell system because of the ability to quickly dismiss incorrect cells and further verify probable hits. It is shown analytically that this is in fact true …

Design Of A Microengineered Pressure Sensor, Ranjeet Alexis

Theses

A new family of microengineered vacuum ionization gauges of an approximate volume of 200µ³ has been designed. These devices can he fabricated using existing semiconductor processing capabilities. The focus of this thesis is to scale down the current state-of-the-art for ionization sensors to micron dimensions. These gauges can be manufactured economically and potentially will be integrated with more complex structures and circuitry. In these devices an active ionization volume of micron dimensions is used for launching ions in a trajectory towards a collection electrode. Ionization of gas species is accomplished by an electron flux of sufficient energy. Analysis of …

Improving The Throughput Of Plasticating Extruders : Measurement Of The Interparticulate Friction Coefficient For Polymeric Particulates With Circular And Profiled Cross Sections, Aiping Chen

Theses

This thesis deals with the coefficient of friction between individual polymeric pellets, the interparticulate friction coefficient (IPFC). It has been measured using a shear cell for a wide variety of circular and profiled cross?section pellets for a variery of polymeric materials. First, the thesis explains the reasons why it is desirable to enhance the IPFC based on the melting mechanisms in a single screw plasticating extruder. By making pellets with profiled cross?section pellets, the IPFC is greater than for pellets of circular cross?section. Second, it describes the test apparatus for measuring the IPFC and the method for calculating the IPFC. …

Improving Solids Conveying In Plasticating Extruders : An Investigation Into Manufacturing Processes And Manufacturing Systems For Profiled Thermoplastic Pellets, Oommen Cherian

Theses

The objective of the thesis is the manufacture of thermoplastic bilobal and trilobal profiled pellets for the determination of the interparticulate co-efficient of friction exhibited by solid beds of such pellets. The enhancement of the interparticulate coefficient of friction is expected to lead to ameliorated solids conveying rates in plasticating extruders.

Predicting the product shape from a profile die is very difficult due to the elastic memory of plastics and the complex boundary conditions. Consequently the cost involved in experimenting with different profile dies is high. Therefore a standard die with several die inserts of varying cross-sections were used to …

Damage Effects To Si-Sio2 Structures Due To Reactive Ion Etching, Moshe D. Bunyan

Theses

This thesis presents the damage effects to the Si ? SiO₂ structures due to Reactive Ion Etching (RIE). The research was carried out on Si ? SiO₂ MOS capacitors which were fabricated using RIE and wet etch (Hydrofluoric acid etch (HFE)) Process. The experiment was carried out using CV technique and Ellipsometry. Various electrical parameters were measured from CV *curves of these MOS capacitors. It was observed that the CV curve obtained for the RIE etched sample showed considerable deviation from that of the control sample. This indicates the presence of excess of interface trap charge density which …

Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan

Theses

Silicon nitride thin films of varying composition and thickness were deposited on silicon substrates by reactive rf diode sputtering of a silicon target using an argon/nitrogen gas mixture. Film stoichiometry could be controlled by varying the partial pressure of nitrogen, the total sputtering gas pressure and the target rf power. Films with refractive index of 2.01, the value for stoichiometric silicon nitride, could be obtained. Film stress was measured by wafer curvature; refractive index and thickness of deposited films were obtained by ellipsometry and interferometry measurements. The etch rate in buffered HF for films with refractive index 2.05 was 29A/min; …

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 …

Configuring Maps For A Satellite Communication Network By Self- Organization, Yizhong Chen

Theses

There are several management tasks in a telecommunication network. Among which traffic management is one of the most important and difficult tasks. It is concerned with maximizing network efficiency when the network is under stress either due to overload or failure. New attempts to automate this task such as expert system based approach are yet to be perfected. In this thesis, we advocate a new concept of traffic management. Our scheme consists of two levels. At the first level, we introduce a Self-organization model to dynamically configure a map for a satellite communication network. The second level is a routing …

An Artificial Neural Network For Redundant Robot Inverse Kinematics Computation, Wibawa Utama

Theses

A redundant manipulator can be defined as a manipulator that has more degrees of freedom than necessary to determine the position and orientation of the end effector. Such a manipulator has dexterity, flexibility, and the ability to maneuver in presence of obstacles. One important and necessary step in utilizing a redundant robot is to relate the joint coordinates of the manipulator with the position and orientation of the end-effector. This specification is termed as the direct kinematics problem and can be written as x = f(q)
where x is a vector representing the position and orientation of the end-effector, q …

An Investigation Of The Dynamics Of Abrasive Waterjet Formation, Md. Ekramul Hasan Khan

Theses

The aim of this research was to investigate the jet formation and the jet behavior, as characterized by the velocity field, the force exerted by the jet on a work-piece and the jet geometry. The velocity and force distributions were measured using a laser transit anemometer (LTA) and a piezoelectric force transducer (PFT) respectively for constant water pressure (334.6 MPa) supply. The jet structure and its instantaneous behavior were visualized by the used of high speed filming. LTA and PFT measuring techniques were established and verified. The measurements were performed under different operating conditions. It was found that at a …

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 …

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 …

Multichannel Input Moniter, Geng Lin Chen

Theses

In order to communicate ,with each other, people must use the same kind of language. MIDI, the Musical Instrument Digital Interface, was established as a hardware and software specification which makes the communication between musical instruments become possible.

What this thesis does is interfacing a musical instrument with other devices using MIDI protocol. The hardware is a multichannel priority interrupt system which has already been done and was included in the discussion of this thesis. The focus of this thesis is concentrated on the software development of multichannel input monitor.

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 …

Design And Analysis Of Movable Boundary Allocation Protocol, Karun Sekhri

Theses

The increasing digital communications traffic will require very high speed networks. The use of high communication speed increases the ratio between end to end propagation delay and the packet transmission time. This increase causes rapid performance deterioration and restricts the utilization of the high system bandwidth in broadcast channel based systems. Using several parallel channels in place of a single channel improves this ratio. For a given system bandwidth the total system capacity is increased by bandwidth division and parallel communication. FTDMA protocols have been suggested for the parallel channel network and these protocols are suitable for different loads. In …

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 …