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 …

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 …

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 …

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 …

Reflection And Transmission Through Achiral-Chiral Interface, Jia-Feng Wang

Theses

Electromagnetic wave propagation through an achiral-chiral interface is analyzed via Maxwell's equations using the appropriate boundary conditions. Experimental data for reflected power from achiral-chiral interface was found to be in qualitative agreement with the analytical results. In addition, coupled mode equations for chiral cladding waveguides were derived and solved for weak coupling. The experimental results of chiral cladding waveguides show that an average of about 0.2° per cm in polarization rotation occurred. These waveguides were fabricated by using spin-coating deposition. The sense of the rotation was found to be independent of the handness of the cladding chirality, which was predicted …

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 …

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 …

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 …

An Optically Powered Cmos On-Chip Power Supply, Jaeyong Jeong

Theses

This thesis presents an optically powered CMOS on-chip power supply for CMOS IC applications. There exists a need for specialized chips that are located remotely and are powered by light supplied through fiber-optic cabling. An optically powered CMOS on-chip power supply circuit described in this thesis is composed of three subcircuits; light to voltage converter circuit, clock pulse generator circuit, and voltage multiplier circuit. Each subcircuit has been analyzed and designed, and simmulated using SPICE 2G.5/6 with 3pm CMOS SPICE parameters from the MOSIS. The circuits layout has been done using MAGIC according to the MOSIS scalable CMOS design rules. …

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 …

A Transputer Based Distributed Graphics Display, Ramana V. Kattula

Theses

The design of a transputer based graphics display is discussed. The problems associated with the single processor graphics systems are described. A solution based on multiple transputers is proposed. The transputer based graphics display described is a general purpose graphics system which can achieve any required compute performance and drawing performance without using special hardware. The display resolution and color depth can be enhanced as per the user requirements with little or no change in hardware.

A Quantization Noise Feedback Technique In Pyramid Image Coding, Zhili Lin

Theses

In communication, we frequently encounter the problem about the trans-mission rate and quantization noise. That is, small quantization noise or high fidelity definitely increases transmission rate, or large quantization noise or low fidelity might require low transmission rate. In our research, we developed a quantization noise feedback technique, with which quantization noise can be reduced greatly at a given transmission rate. We applied this technique in pyramid image coding environment. An error analysis in frequency domain was carried out. Error estimation for pyramid image coding with and without quantization noise feedback was made. Finally, plenty of computer simulation confirms our …

Landmark-Based Partial Shape Recognition By A Two-Stage Bam Neural Network, Xianjun Liu

Theses

In this thesis, we develop a Bitfirectional Associative Memory (BAM) based neural network to achieve partial shape recognition. To recognize objects which are partially occluded, we represent each object by a set of landmarks. The landmarks of an object are points of interest relative to the object that have important shape attributes. To achieve recognition, feature values (landmark values) of each model object are trained and stored in the network. Each memory cell is trained to store landmark values of a model object for all possible positions. Given a scene which may consist of several objects, landmarks in the scene …

Characteristic Shape Recognition With Fuzzy Dustering, Kalpesh J. Patel

Theses

The problem of shape detection has been treated as one of clustering. A fuzzy-shell clustering(FSC) has been formulated as non linear least squares with fuzzy memberships as weights. An improved FSC algorithm has been proposed based on this formulation to partition the input feature vectors into hyper-spheres. To illustrate the usefulness of improved FSC we have provided numerous examples in 2-D space. The idea has been extended to fuzzy ellipsoidal-shell clustering (rESC). A FESC algorithm has been proposed to partition the input feature vectors into ellipsoidal patterns. To substantiate our claims regarding usefulness of this algorithm we have provided many …

Simulation And Analysis Of Priority Classes In Extended Token Based Local Area Networks, Bhavinkumar R. Pathak

Theses

Recently, Local Area Networks carrying multiple priority classes of messages have received considerable attention. The IEEE 802.5 token ring standard defines an optional priority scheme to handle different priority classes of messages. A simulation model of symmetric priority based networks, consisting of token ring networks interconnected by a bridge is considered. Messages are divided into two priority classes, namely, high priority traffic and low priority traffic. High priority traffic is guaranteed access on the channel, whereas low priority messages are served when the system determines that no high priority messages are currently waiting. The simulation results are used to evaluate …

Microcomputer-Based Visual Controller And Data Logger System, Xiao-Fang Qi

Theses

This thesis paper describes the firmware design, instead of the hardware logic design, makes the machine vision hardware system economical, intelligent and expandable. It shows the construction and testing of a novel remote low speed machine vision control system, which also has functions as data logger and is capable of auto control. The system has 9 analog input channels available, and more. It also has 4 digital output channels for controlling external devices. This work also implemented a way to transfer the grabbed image to a PC/XT. In the 256 graphics mode of the VGA, 64 B&W gray levels can …

A Self Testing Strategy For The Wafer Scale Hierarchical Memory Architecture, Maremanda V. R. Rao

Theses

Since the early 1960's, semiconductor chips have matured from single transistor devices to one million transistors per chip. The integration has been achieved by reducing transistor dimensions, and by increasing chip sizes. However, physical limits are being reached as submicrometre dimensions are approached. Fault tolerance has to be used to maintain the increase in the chip complexity. Yield improvement is only one of the many possible gains of fault tolerance. The dense integration of logic on a single chip also creates a huge test problem. in recent years a great deal of effort has gone into the development of yield …

The Interconnection Network Analysis Package, Nadeem Sabbar

Theses

This thesis focuses on the development of the Interconnection Network Analysis Package (INAP), and the use of INAP to analyze minimal permutation networks. The INAP code is written in C language using Turbo C compiler. Although the INAP has been used to analyze the subject networks it is not a dedicated system. It gives the user the freedom to create the permutation network from scratch (1-8 inputs and 1-7 stages), and then to process it for any number of stages.

The INAP made the analysis of five input networks easy and efficient. The networks have been analyzed stage by stage. …

Microengineered Thermal Conductivity Vacuum Pressure Sensor, Sanjay Talreja

Theses

This thesis details the first designs for microengineered vacuum pressure gauges based on silicon microelectronic technology. A monolithic polysilicon air-bridge structure (supported at both ends), within a Wheatstone bridge circuit, is used as a pressure sensor. The device utilizes the change of the thermal conductivity of a gas with ambient gas pressure. The doubly supported beam functions as a temperature sensitive resistor with a negative temperature coefficient of resistivity. Thermal change of resistance monitored as a measure of ambient pressure constitutes the basis of operation for this sensor. The sensor operates over the pressure ranging from 1 Torr to 10 …

Simulation And Analysis Of Integrated Lans For Hospital Environment, Naveen K. Verma

Theses

Hospitals generate a large number of data sets of different types and formats and it is required to integrate these data sets for their rapid and simultaneous communication in order for a better treatment of patients and to cut the escalating costs. A better approach to meet this requirement is to have a distributed system linked all together with a high capacity LAN using an efficient integration method.

This thesis begins by studying the characteristic feature and suitability of Queued Packet & Synchronous Exchange (QPSX) network architecture. The network models are simulated for QPSX, Ethernet and Token Bus networks for …

Measurement Of Cluster Size By Retarding Potential And Time-Of- Flight Methods In An Ionized Cluster Beam Deposition System, Yung-Kuan Wang

Theses

The goal of this research was to study the mass distribution of ions generated in the Ionized Cluster Beam (ICB) deposition system. The ICB deposition method has been used to form high quality films of metals and other materials. It was postulated that the clusters consisting of hundreds and thousands of atoms produced by vapor expansion in the ICB source are responsible for the superior film properties. However, consistent experimental evidence concerning the cluster mass distribution, or even the existence of such clusters in the ICB apparatus, was lacking.

Two methods of cluster ion mass spectroscopy were used in this …

Modeling And Analysis Of Electrical Properties Of Polycrystalline Silicon Films, Yunsheng Wang

Theses

In recent years, investigations on polysilicon grain structures have shown that all polysilicon films by LPCVD which are most used in today's integrated circuits are columnar in structure. In this work, a square columnar grain structure has been considered to model electrical properties of polycrystalline silicon films instead of all previous one-dimensional grain structure models. By solving Poisson's equation with certain boundary conditions, we find that the barrier height at the corners of the grain is lower than that in the one-dimensional case. Assuming the trapping state energy level as constant, we also find that this level has a value …

Microengineered Silicon Beam Switch For Fiber Optics, Hsu-Nien Yang

Theses

A novel microelectromechanical actuator has been designed for moving an optical input fiber into alignment with one of three stationary output fibers. This switching device thus can connect an input optical port to one of 3 selected optical ports. The actuation force is created by a vertical-drive armature measuring 0.5x2.7 mm² mechanically tethered to the input optical fiber. A force of 2.33 mN is obtained from the linear acturator when the vertical stator armature gap is one micron and the applied three phase voltage is 140 Volts. The required force is a function of the input fiber length, e.g. …

Max/Min : A Novel Rank Order Based Filter Family, Raafat E. Kamel

Theses

In the early development of signal and image processing, linear filters were the primary tools. Their mathematical simplicity made them easy to design and implement. They also offered satisfactory performance in many applications. However, they show poor performance in other cases, such as image processing.

Nonlinear filtering offered a solution to these problems. Nonlinear filtering has undergone a lot development for a long time. Among the first known nonlinear filters was the median filter, which was proposed by Tukey. Median filter preserves signal or image details better compared to a linear filter. Later other nonlinear filters were developed, including median …

Edge Matching Of Aerial Scenery Using Fourier Descriptors, Ananth Kittappa

Theses

In this report an integrated method of classifying aerial images as related to photo stereo grammetry is discussed. In this method, an investigation of Fourier descriptors as features for the edge matching approach is carried out. The efficient calculation of the Fourier Descriptors is made possible by applying the polygonal approximation method to the original edges. In order for the features to be invariant to rotation, scaling and starting point shift, a normalization technique is adopted. Initially the Fourier Descriptors are tested for synthesized test datasets and it was proved that the variances of the Normalized Fourier Descriptors was a …

Decomposing Non-Product Form Queuing Lattices Through Simulated Annealing, Jr-Chin Lin

Theses

A random, heuristic search called Simulated Annealing is adapted to decompose the state transition lattice of Non-Product Form Queuing Models. Simulated Annealing Algorithm has been successfully applied to a number of optimization problem such as The Traveling Salesman Problem, Graph Partionning, Physical Computer Design, VLSI Chip Design, Image Processing,... etc. It has the advantage over other gradient descent techniques to solve the combinatorial problems. The solution can escape from local minimum by adding Boltzmann Distribution Factor to the algorithm. Most lattice of non-product form queuing models can be decomposed into Solvable Subsets through this algorithm, and solvable subset is the …

Investigation Of Micromechanical Properties Of Tungsten Silicide Thin Films, Bharat Pathak

Theses

Micromechanics is a field which is maturing. Recent research interest in micromechanical structures has focussed on the fabrication of microactuators and microsensors. These microsensors and actuators can sense very small changes in the environment without disturbing the equilibrium of the environment. The refractory silicides are some of the compatible materials used to integrate the micromechanical structures and the interfacing electronic circuits on the same chip. As a result of this, the thermodynamic, electrical and mechanical properties of transition metal silicides should be given a closer look for micromechanical applications.

This thesis details the design and fabrication of tungsten silicide moveable …

Design And Simulation Of Submicron Microelectronic Vacuum Triodes, Hou-Jun Wang

Theses

This thesis presents the first design and detailed Simulation of submicron vacuum microelectronic triodes static characteristics. In this thesis a new 5-electrode active device is emphasized.

These devices have potentially important advantages over semiconductor devices. They can be used in extreme environments. The picosecond transit time for internal electron ballistics provide optimism for very fast devices applications. It appears reasonable to fabricate these devices using standard VLSI processing equipment. Further, the micron dimension makes " vacuum microelectronic chips" a reasonable goal.

Devices are characterized for static parameters including electron trajectories, electric field contours, and voltage potential contours. The field emission …