Digital Commons Network^™

An Investigation Of Electrical And Optical Properties Of Reactively Sputtered Silicon Nitride And Amorphous Hydrogenated Silicon Thin Films, Tae Hoon Kim

Theses

Thin films of silicon nitride and amorphous hydrogenated silicon were prepared by radio frequency reactive sputter deposition and their properties optimized for their use as low temperature passivation coatings for optoelectronic devices. The effect of various sputter deposition parameters on the conduction and optical properties were studied. Infrared spectrophotometry and ellipsometry were used to determined the optical properties of the films whereas the electrical properties were determined from current-voltage measurements of MIS capacitors.

Typical parameters of a sputter deposition run for the best Si₃N₄ films were: base pressure, 1-2x10^-6 torr; sputtering pressure, 5 mtorr; nitrogen partial …

A Model For The Determination Of Market Based Pricing Of Telecommunication Products, Katherine J. Sullivan

Theses

The deregulation of AT&T, has impacted telecommunication product pricing in the U.S. market. Previously, pricing had been based on cost plus mark-up, as stipulated by regulatory commissions. Now, pricing decisions require consideration of the competitive impact, consumer demand for the product, corporate pricing objectives and marketing strategies. This paper proposes a pricing process that is relevant for this new environment which enables the product manager to price properly.

The method proposed utilizes microeconomic theory and takes into account the product test price, unit cost, opportunity cost, nonprice factor cost and consumer demand. Incorporating a number of different pricing strategies, it …

Agitation Requirements For Complete Dispersion Of Emulsions, Dun-Huang Tsai

Theses

An investigation on the minimum agitation speed required to achieve complete dispersion in liquid-liquid systems has been carried out. A model based on the momentum balance for a droplet and on Kolmogoroff's theory of isotropic turbulence was used for the prediction of the role of the most important variables on the minimum agitation speed. The equation so derived can be expressed in terms of a number of non- dimensional groups (such as Re, Ar, and Su). For geometrically similar systems the equation contains only one adjustable parameter ( to be determined experimentally) in the form of the proportionality constant correlating …

Biosynthesis Of Amine Oxides Using Calcium-Alginate Immobilized Hog Liver Microsomes : An Evaluation Of Process And Reactor Design, Ioannis I. Valvis

Theses

An evaluation of the biocatalytic ability and the potential utilization of Calcium-alginate immobilized hepatic microsomes (beads) for the biosynthesis of amine oxides has been performed, To accomplish this task, the following three areas Were investigated: immobilization, catalytic biooxidation ability, and reactor configurations.

Immobilization was found to result in higher yields over free microsomes at the expense of higher cofactor requirements. Refrigerated drying of immobilized micro-somes appears to be a better storage technique than wet storage in buffer. Smaller beads resulted in higher rates than larger beads, but size did not affect the overall yield.

Chlorpromazine (CPZ), diphenylamine (DPA) and 4-hydroxy-2,2,6,6-tetramethylpiperidine …

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 …

Use Of Recirculation Reactor To Study Biodegradation Of Aroclor 1242, A Polychlorinated Biphenyl, Babu S. Sanji

Theses

The performance of immobilized microorganisms in the detoxification of hazardous waste was investigated using a recirculation flow reactor, run in a batch mode. A mixed microbial population from a wastewater treatment plant was immobilized in calcium alginate gel. The bio-oxidation ability of these microbes towards a model toxin Aroclor 1242 (R) (PCB 1242) was studied.

A non-ionic surfactant (Triton X-405 (R)) was used as a medium in the enhancement of the solubility of Aroclor 1242 in aqueous phase.

Dissolved oxygen concentration was monitored using a flow Clark-type dissolved oxygen probe. Oxygen consumption was compared to the biodegradation of Aroclor 1242. …

Design Of A Fiber Optic Oxygen Sensor Based On Immobilized Hemoglobin, Mendu Govind Raj

Theses

The fiber optic Oxygen sensor consists of a thin layer of immobilized deoxyhemoglobin at the common end of a bifurcated fiber. Immobilization is done using the alginate gel procedure. The immobilized reagent is separated from the standard oxygen sample by the gel with or without semi-permeable membrane, and the entire configuration is enclosed in an oxygen free sample cell. Light from a tungsten-halogen lamp, filtered through a 405nm filter is passed through one arm of a bifurcated fiber to the sample cell. The reflected intensity (a highly polished aluminum foil or a plate is placed at the bottom of the …

Investigation Of Forces In The Course Of The Water Jet--Work Piece Interaction, Hung-Yuan Li

Theses

This study is concerned with the dynamic of the interaction between the water jet and the work-piece. The piezoelectric transducer was used to construct an experimental setup. The simultaneous use of the constructed setup and strain gage enables us to validate the experimental procedure. The forces in the impingment zone were measured at different operational conditions. Totally about 400 different combinations of these conditions were tested. It was found that the force is mainly determined by the diameter of the sapphire. The effects of the abrasive size , abrasive flow rate, the diameter of the carbide tube, and the stand-off …

Rf Characterization Of A Directly Modulated Ingaasp Buried Heterostructure Laser Diode, Charlotte Alvarez

Theses

The use of fiber optics for the transmission of microwave signals had its beginnings in 1984. Applications were limited to the lower microwave frequency regions. Technology in this field is advancing rapidly due to the high demand driven by the telecommunications community for high speed digital applications. Extensive research and development efforts are underway by both the component manufacturers and the subsystem end user. Most of the near term applications of microwaves in fiber optics are in weapon systems and communication systems for military and other government agencies.

The high frequency modulation characteristics of Lytel's InGaAsP 1300 nm buried heterostructure …

Design Of Bridge Inter-Connecting Token Ring & Token Bus Local Area Networks, Kasinath Anupindi

Theses

A Bridge interconnecting two Local Area Networks has been modelled. The two interconnected networks are the Token Ring and the Token Bus LANs. Concepts of Queueing theory have been employed in the design. Initially it is assumed that the buffer size at the Bridge is infinite. Further it is assumed that the arrival rate of the messages is Markovian and the service rate is General, Le it is an M/G/1 system. Expressions for the average waiting time at the Bridge and the size of the buffers is computed. Graphs for various parameters have been plotted. Based on these graphs the …

Comparison Of Various Techniques For The Detection Of Lines In 2-Dimensional Images, Somayajulu Bhamidipati

Theses

The detection of straight lines in 2-dimensional images leading to polygonal approximation to the boundaries of the objects is one of the important stages in scene analysis as it leads to the description of the images. The comparison of three diverse approaches for this problem in terms of the efficiency and accuracy is made, and their performance for different types of data and different sets of parameters is studied in this thesis.

The data points are generated using either an edge detection algorithm using chain encoding on real images or a synthetic data generator, which can create a variety of …

Data Flow Dependency Generator, Chin-Piao Chan

Theses

Data flow is a new approach to parallel computing. The concept is to enable the execution of an instruction whenever its operands become available. The only constraints in a data flow machine are the data flow dependencies between instructions.

In this thesis, a simulation package called the Data Flow Dependency Generator is developed. This package is designed to express the idea of data flow computations, the data flow dependencies and the use of multiprocessors.

Given a number of processors, a number of time units for each operation and a program, the Data Flow Dependency Generator finds the data dependencies between …

Utilization Of The Theory Of Constraints Approach For Improving A Manufacturing Enterprise Profitability : A Case Study, Yaron Chaut

Theses

The past two decades have been a difficult period for the U.S. as it lost its dominant position in one manufacturing industry after another to Japan. The American worker was initially blamed for this phenomenon - he was too expensive, was less productive, and produced lower quality products then the Japanese worker. The opening of factories in the U.S. managed by Japanese with American workers proved this claim to be wrong, as their products were competitive and often even better then the original Japanese products. It also indicated that the Japanese production planning and control methods are the primary reason …

A 3-D Tactile Sensor With Digital Output, Sin-Shou Cho

Theses

This thesis details the design of a new tactile sensor for general-purpose robot manipulators. Such manipulators, designed to be functionally equivalent to the human hand, will require sensor arrays that fulfill several requirements : (1) many sensor elements to minimize tactile imaging time, (2) close spacing of small sensing elements for fine spatial discrimination, (3) ability to be molded to a convex fingertip surface for taction on concave surfaces, (4) tolerance to over-scale forces without damage. In addition to the above, which are considered requirements, several other characteristics are desirable. Foremost is the ability to sense shear forces, which provide …

Estimation Of Modified Proctor Densities Based On Visual Identification, Ramesh Damodaram

Theses

Often in construction jobs requiring controlled compaction, there is a delay involved in testing the soil sample to be used as a structural fill. Here a rational approach has been adopted to get these values from 600 test data available. Using these data, appropriate relationships between grain sizes, maximum dry densities and optimum moisture content were developed. From these, two tables were derived to estimate the maximum dry density and optimum moisture content based on grain size distribution.

In a fill control job, if the borrow pit happens to change, the field personnel could obtain soil samples and send them …

A Model For Estimating The Cost Of Developing An Expert System, Louis Vincent De Troia

Theses

This paper describes a model that can be used to assist engineers and managers in estimating the cost of developing an expert system. Numerous models are available for estimating the cost of developing conventional software systems [1] [2] [3]. However, relatively little work has been done in the area of expert systems cost estimation [3] [4].

Estimating the cost of any software development project is a difficult task, yet software developers are required to provide reliable estimates of the cost of development early in the development life cycle, quite often before many of the system requirements have been defined. While …

Messaging, The Effects Of The Use Of Voice Mail On The Use Of Electronic Mail, Terese M. De Troia

Theses

A number of office automation products have evolved over the years to address the messaging needs of organizations. The 1800's brought us telegraph systems which led the way for teletype and Telex systems, followed by facsimilie, computer-based message systems, document based electronic mail and, most recently, voice store and forward (or voice messaging) systems (Advances in Office Automation, 1985). Voice messaging systems, a newly emerging method of communications, are having a significant impact on communications. The concept of messaging services is rapidly gaining acceptance in business communities (Girishankar 1986, Hirschheim 1985). With costs rising and time becoming more valuable, organizations …

Two Domain Heat Transfer Studies Using A Coupled Finite-Difference And Boundary Element Programs, Serap Dikmenli

Theses

An iterative coupling of a finite-difference boundary layer code "STAN5"' and a boundary element code "BEASY"2 have been used to study two dimensional convective-conductive problems. The coupling method essentially leaves undisturbed the codes of these programs and uses their custom features in their applicable domains. The boundary layer program is used-in the convective domain, while "BEASY" is used in the solid domain. Compatability conditions are established between these domain solutions and an iterative scheme is used until these conditions are mutually satisfied.

The indirect communication of compatability (boundary) criteria between these programs was achieved by two editor/data-transferor like programs. Combined …

Expert Systems Approach For Means Of Egress Analysis, Dimitrios N. Dontas

Theses

The use of Expert Systems has grown dramatically during the 1980's. Developed as a branch of Artificial intelligence, knowledge based Expert Systems were at first of academic interest only. With successful application of knowledge based Expert Systems to medical and other diagnostic problems, industrial and commercial use of this technique is also increasing significantly. As of 1986, fifty percent of the Fortune 500 companies are embarked in their own Expert Systems research.

A variety of knowledge based Expert Systems has been developed for the Civil Engineering design and construction industries. The applications cover a wide range of subjects, including among …

Effective Techniques For Selection Of Information Systems Personnel, Robert Reginald Downs

Theses

Although major developments in information systems have occurred within the last two decades, staffing to manage these systems has received limited attention. Staffing information systems personnel is investigated in this study to develop effective techniques that can be used in the selection process.

Recent literature on selection and staffing has been reviewed to establish methods that can be used to identify qualified candidates. Technological developments and the resulting effects upon organizational operations are examined, revealing the transition in the information systems management function as well as the effects upon the role of these personnel. The qualifications that are associated with …

A Methodology For Evaluating Prospective Investments In Flexible Automation, Werner A. Eikenbusch

Theses

The flexible automation of production systems (FA) provides the technology necessary for competitive success. However, the use of traditional budgeting methods has proved unsatisfactory when evaluating this type of investment, primarily because of the inadequate consideration being given to the resultant strategic benefits.

A methodology considered suitable for evaluating FA investments is proposed together with an illustrative application. To determine its industrial usefulness, manufacturing managers of North American and West German companies were surveyed both via interviews and via questionnaires. Their response confirms the merit of the procedure, despite the differences in competitive foci found between the American and the …

Stepping Motor Control And Position Monitoring, Pei-Kuan Feng

Theses

Stepping motors provide precise digital control of speed, without speed detector feedback. A stepping motor can produce a large torque for a relatively small displacement, without a shaft-position sensor or special compensation. This provides accurate control of motor position. This thesis describes the development of stepping motor torque characteristics and the different approaches stepping motor phase current waveform detection. It is shown that one of the most useful indicators of rotor position is the initial rate of current rise. The Hybrid, Permanent-magnet and Variable-reluctance step motors have been applied in the drive circuits. The open-loop control circuits are implemented to …

An Investigation Of Interrupt Handling Schemes In Pipeline Processors, Shailesh Ratilal Gami

Theses

In order to acheive higher performance in a pipeline processor, proper interrupt handling is essential. In a pipeline processor, interrupt handling is difficult because many instructions are in the processor at the same time. This study describes and evaluates the different solutions to interrupt handling. Several pipelined 32-bit microprocessors have also been studied and their architectural and programming features are compared.

The Tapered Dielectric Rod-Conical Antenna, Nicholas I. Georghiades

Theses

The problem of the linearly tapered dielectric rod/conical antenna, excited by the HEI1 hybrid mode in a metallic circular waveguide , is rigorously studied. A theoretical model, and numerical investigation for the radiation characteristics of such an antenna are presented. The model is based on the combination of classical analysis of the Electromagnetic Fields within the dielectric rod, Local Mode Theory, and the Equivalence Principle for the determination of equivalent current distributions.

The far-zone radiation field is considered to be the summation of the fields produced by two radiative components in the dielectric rod/conical structure: The "aperture" of the uniform …

Micro Cad/Cam System Selection And Implementation, Christian Georg Haas

Theses

The rapid growth of the computer market in the last four decades causes difficulties in evaluating the various systems and configurations of this complex market.

This thesis focuses on graphics capable microcomputers in the computer aided design (CAD) and computer aided manufacturing (CAM) field. The thesis emphasizes the technical possibilities such a system offers in terms of hardware, software and applications. Each hardware and software component is detailed to give a new-comer the opportunity to update him or herself in this high technology field. Technical information, as well as installation and implementation are described. Also, provided are lists of several …

Microcomputer-Controlled Respiratory Rate Monitor, David John Hartmann

Theses

In order to measure the metabolic change in an animal due to the administration of anti-obesity drugs, an instrument was constructed which will allow the continuous sampling of twelve individual animals residing in enclosed chambers. The instrument is based on the principle of Indirect Calorimetry, which measures metabolic rate by sampling the inlet and outlet concentrations of respiratory gases (oxygen and carbon dioxide) of the chamber. The system is controlled by an IBM PC which will control six chambers or twelve chambers simultaneously.

The system assesses the metabolic rate of the animal by calculating the Respiratory Quotient (RQ) and the …

Performance Of Single Dwell Serial Synchronization System, Chan-Yee Hsiung

Theses

By using the sampling theorem, the problem of the detection of a signal in white Gaussian noise, reduces to the consideration of the sum of the squares of statistically independent Gaussian variates. If the transmitter and and receiver are not synchronous, then no data transmission is possible and the decision statistic has a central chi-square distribution. Otherwise, the decision statistic has a non-central chi-square distribution. Also, this. paper presents a method to calculate the mean and variance of the acquisition time which are the most important parameters to evaluate the performance of a PN spread synchronization system. In addition, the …

Role Of Contact Stresses In Surface Fatigue And Wear, Chih-Chi Huang

Theses

This thesis is devoted to the role and analysis of stress distribution at the area of load and slide contact in the surface fatigue. The orthogonal shear stresses are critical stresses for surface fatigue in pure rolling contact. On sliding combination with rolling, the maximum shear stresses become to be the prime cause for surface fatigue because they move from subsurface toward the surface. The compressive residual stress induced during manufacturing could increase the resistance to surface fatigue. Sliding speed rarely affects the stress distribution and surface fatigue. From investigation of the stick-slip region in the contact area, sliding wear …

The Application Of Zero-Sum Games To Low Sensitivity Optimal Control, Jun Huang

Theses

This thesis deals with the synthesis of low sensitivity optimal control systems. Zero-Sum games are applied to the first order linear differential equation system. The goal is to obtain an optimal control of the system performance, and at the same time, reduce the sensitivity of the performance index and sensitivity trajectory.

In this thesis, the quadratic index of performance is selected in the argumented system which is combined/ the system equation with the sensitivity equation. Two control variables U & V are selected to maximize and minimize the system, in order to obtain the optimal value of the system.

Two …

Reliability Of Packaging In Microcircuits, Zia Iqbal

Theses

The semiconductor industry is faced with the problems of how to increase the level of reliability of semiconductor parts being used in the electronic systems which have had their lifetimes extended through new and better system design.

This paper deals with the reliability of packaging constructions commonly used in large scale integration / integrated circuits and will present the failure mechanisms and failure modes which can arise when proper processing is used. In addition, the materials used in each construction and how they affect reliabilty will be analyzed.

It is not the intention of this paper to present any new, …