Engineering Commons^™

Characterization Of Fatigue Damage In A Metal Matrix Composite (Scs-6/ Ti-15-3) At Elevated Temperature, Brian P. Sanders

Theses and Dissertations

The fatigue characteristics of a unidirectional titanium based metal matrix composite (MMC) were investigated at elevated temperature (427°C). A hybrid strain controlled loading mode was used to subject the 0° and 90° laminas to fatigue. Along with the fatigue tests, microscopy and analytical modeling ware also conducted. This combination of activities led to defining the initiation and progression of damage and deformation in the MMC. Hen loading was parallel to the fiber on, the fatigue behavior was initially dominated by creep deformation of the matrix. Then, depending on the maximum strain, specimen failure was the result either fiber fractures or …

Computer Program For Analysis Of Embankments With Tensile Elements, Mikhail E. Slepak, Tommy C. Hopkins

Kentucky Transportation Center Research Report

A generalized computer program for analyzing stability of earth structures reinforced with geosynthetics (geogrids, geotextiles etc.) was developed in this research study. The newly proposed computer program was built in such a way that a reinforced slope stability problem may be analyzed using a variety of limit equilibrium methods including Hopkins', Morgenstern and Price's, Bishop's methods, Raulin's perturbation method, as well as new perturbation methods proposed by the authors of this study. It was shown in the research study that two versions of the Bishop's method were possible in the case of reinforced analyses: the traditionally used version referred to …

Visual Observations Of Parking And Driving Areas And Drainage Conditions On Colverfield Lane Fort Wright Trace, Fort Wright, Ky., David L. Allen

Kentucky Transportation Center Research Report

On September 30, 1993, the Condominium Council of Co-Owners of Fort Wright Trace in Fort Wright, Kentucky requested of the Director of the Kentucky Transportation Center that a member of his staff meet with them to review and visually inspect the drainage and pavement conditions in their community. The Head of the Pavements Section met with representatives of the Council on October 13, 1993 as a part of the Transportation Center's Technology Exchange Program.

A visual inspection was conducted of Cloverfield Lane and its associated parking areas beginning at the intersection of Cloverfield Lane and Castle Hill Lane and continuing …

A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory

Department of Industrial and Management Systems Engineering: Presentations

One of the more difficult tasks facing a modeler in developing a simulation model of a discrete part manufacturing system is deciding at what level of abstraction to represent the resources of the system. For example, questions about plant capacity can be modeled with a simple model, whereas questions regarding the efficiency of different part scheduling rules can only be answered with a more detailed model. In developing a simulation model, most of the actual features of the system under study must be ignored and an abstraction must be developed. If done correctly, this idealization provides a useful approximation of …

Periodic Pn Sequence Delay Estimation Using Phase Spectrum Data, Kurt Louis Kosbar, Jorge J. Zaninovich

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm for estimating the delay of a periodic pseudonoise (PN) sequence is presented. It is a rapid, block-based estimator that can be used for both linear and nonlinear codes. The algorithm exploits the periodicity of the difference between the phase spectra of the received sequence and a local reference. The estimator takes the Fourier transform of the phase spectrum difference data, and searches for the fundamental frequency. Unlike previously described methods, phase unwrapping is not required. The performance in the presence of additive white Gaussian noise (AWGN) and a continuous wave (CW) jammer is investigated using computer simulation. Comparisons …

Deposition Of Particles In A Convergent Channel, Hsi-Chung Chiou

Dissertations

The deposition of suspensions for uniform flow in convergent channels under the combined influences of inertia, viscous, gravity and electrostatic image forces were studied theoretically. A two dimensional, steady, incompressible, laminar flow with uniform velocity profile was assumed.

It was found that when the ratio of charge parameter to gravity parameter, Q/G, is greater than 5, the deposition is dominated by the electrostatic image force alone and that the gravity effect can be neglected. When the ratio of charge parameter to gravity parameter, Q/G, is less than 0.001, the image force can then be neglected. It was also observed that …

Engineering Design Of An Anaerobic-Aerobic System To Treat Chlorophenols, Chih-Ju Jou

Dissertations

The present work was aimed at determining the effect of the main operating parameters on the performance of an anaerobic-aerobic reactor system to degrade toxic chlorinated compounds. In previous work conducted in the Biological Treatment Lab at NJIT it was shown that this system is capable of achieving the complete degradation of chlorophenols. In that system, reductive dehalogenation took place in the first anaerobic reactor, which was followed by a second aerobic reactor in which the degradation products of the first reactor were mineralized. In the present work the role of a number of parameters that can have a significant …

Pyrolysis And Oxidation Of Chloromethanes Experiment And Modeling, Wenpin Ho

Dissertations

An experimental study on pyrolysis and oxidation of CH₂Cl₂ and CH₃Cl in oxygen/hydrogen or oxygen/methane mixtures and argon bath gas was carried out at 1 atmosphere pressure in tubular flow reactors. Degradation of CH₂Cl₂, or CH₃CI, along with the formation and destruction of intermediate and final products was analyzed systematically over 873 to 1273°K, with average residence times of 0.2 to 2.0 seconds.

Thermochemical parameters: enthalpy, entropy, and heat capacities for many chloro-oxy-carbon products and intermediates are calculated using the techniques of group additivity and the THERM computer code. …

On Generalized Adaptive Neural Filter, Zhiqiang Zhang

Dissertations

Linear filters have historically been used in the past as the most useful tools for suppressing noise in signal processing. It has been shown that the optimal filter which minimizes the mean square error (MSE) between the filter output and the desired output is a linear filter provided that the noise is additive white Gaussian noise (AWGN). However, in most signal processing applications, the noise in the channel through which a signal is transmitted is not AWGN; it is not stationary, and it may have unknown characteristics.

To overcome the shortcomings of linear filters, nonlinear filters ranging from the median …

Agitation Requirements For Complete Liquid Dispersion In Liquid-Liquid-Gas Systems, Emad Ahmad Abu-Hakmeh

Theses

A number of studies have been published in the literature on the determination of the agitation intensity at which two immiscible liquids become completely dispersed in mechanically agitated vessels. However, no information is currently available on the agitation intensity required for the complete dispersion of two liquids in the presence of an additional gas phase. Therefore, the main objective of this study was to experimentally determine the minimum agitation speed for complete liquid-liquid dispersion, N_cd, in liquid-liquid-gas systems as a function of gas flow rate, impeller type, impeller size, and impeller off-bottom clearance. The minimum agitation speed was …

Design, Fabrication And Characterization Of Infrared Filters, Samiul Amin

Theses

In-situ temperature monitoring, mapping, and control have become significant in semiconductor processes. Temperature of these processes can be measured by making use of the thermal emission from substrates in the infrared region. Various methods have been proposed to provide multicolor infrared detection. One such method involves placing segmented infrared filters close to the focal plane. The present study aims at gaining an insight into the design, fabrication and characterization of infrared filters. Filters were designed and fabricated with peak transmission at 1.5, 3.0, and 4.5 m. Extensive spectroscopic studies, using FTIR spectroscopy, have been performed in the infrared region, on …

Traffic Management Of A Satellite Communication Network Using Stochastic Optimization, Ambalavanar Arulambalam

Theses

The performance of nonhierachial circuit switched networks at moderate load conditions is improved when alternate routes are made available. However, alternate routes introduce instability under heavy and overloaded conditions, and under these load conditions network performance is found to deteriorate. To alleviate this problem, a control mechanism is used where, a fraction of the capacity of each link is reserved for direct routed calls.

In this work, a traffic management scheme is developed to enhance the performance of a mesh-connected, circuit-switched satellite communication network. The network load is measured and the network is continually adapted by reconfiguring the map to …

Detection Of Planar Facets In Noisy Range Images, Ajey S. Atre

Theses

Segmentation of the image is one of the major tasks of a machine vision system designed for constructing a three-dimensional representation of the object being imaged. A robust approach for segmenting planar surfaces from range images is presented in this paper. An algorithm based on clustering through fuzzy covariance matrices, which has been proposed by Gustafson and Kessel is considered for planar segmentation. However this algorithm performs poorly if the data is noisy, which is usually the case in real life applications. In order to handle noisy data, a robust modification, based on the "noise clustering" concept, is introduced to …

Attachment Systems For Curtain Wall Construction And Maintenance Requirements, Peter S. Donaghy

Theses

Curtain Wall construction has become a familiar and widely used method for enclosing structures. Since the 1950's this type of enclosure has become increasingly the most popular choice of Designers and Builders. During this period of development, however, acceptable and uniform building standards have not evolved to create adequate quality control.

This thesis investigates some of the design requirements of Curtain Walls, in particular the attachment system, and the maintenance costs that are directly related to the attachment system and the consequences of such failures.

Computer Assisted Molecular Modeling Of Thymidine Nucleoside Analog Inhibitors Of Hiv-1 Reverse Transcriptase, Mark A. Fisher

Theses

An active analog approach to receptor mapping was used to identify the three dimensional structural characteristics associated with a series of thymidine nucleoside analog inhibitors of HIV-1 reverse transcriptase (RT) that may be essential for their activity. Atomic substitutions at the 5 and 3' positions of nucleoside analogs confer global structural and electrostatic changes that result in either increased or diminished inhibitory activity. From a structural perspective, the activity differences can be attributed to the presentation of select atoms in three dimensional motifs that are common to all active compounds and absent or distorted in inactive/poorly active compounds.

The identification …

Laser Ablation Of Silicon Surfaces : The Effects Of A Low Level Background Light, Taposh Kumar Gayen

Theses

The performance of high speed optoelectronic and microelectronic devices largely depends on the uniqueness and development of the fabrication technology. Laser ablation has proven to be an effective three dimensional surface patterning technology. In this thesis, we present findings on the patterning of semiconductor surfaces using laser ablation in air as well as in solutions.

In this thesis, we suggest that the depth of a pattern induced on silicon by firing a pulsed excimer laser in air varies almost linearly with the number of pulses. We report that a He-Ne laser as a background light source has virtually little or …

An Analysis Of A Custom Expanding Total Femoral Prosthesis With A Rotating Hinge Knee, Ramarao Gundlapalli, V. Gundlapalli

Theses

Osteosarcoma is the most common malignant bone tumor in the pediatric age group. This thesis presents the analysis of a total femoral prosthesis implanted in a 9 year old black male. The design includes a bipolar, expanding mid-shaft component, and a rotating hinge knee used in the reconstruction of the patient's right lower limb after surgical resection of the femur. The areas being analyzed are (i) the trochanteric attachment, (ii) the expanding component, and (iii) the rotating hinge knee. The stresses acting on the cables reconnecting the greater and lesser trochanter were determined for bipedal stance, single-legged stance, stance phase …

An Efficient Guaranteed Bandwidth And Balancing Mechanism For High Speed Mans, Venediktos Hadjisavvas

Theses

The Distributed Queue Dual Bus (DQDB) has become the IEEE 802.6 stan-dard for Metropolitan Area Networks (MANs). The main advantage of DQDB is that its throughput performance is not affected by the network parameters such as size, number of connected stations, or channel bandwidth. Its main drawback is that the location of the stations on the bus strongly affects their performance. For this reason a Bandwidth Balancing Mechanism (BBM_DQDB) has been proposed and included in the 802.6 standard that can provide the requested bandwidth by the lightly loaded stations and evenly distribute the remaining bandwidth among the overloaded stations. The …

Model Parameter Identification Of The Oscillatory Potential In The Electroretinogram, Sung Hoon Jang

Theses

A mathematical model of the oscillatory potential which may be a useful clinical tool to diagnose the progression of diabetic retinopathy. The model has been investigated by compressing from oscillatory potential into three parameters which contain most of the information for the oscillatory potential data.

About thirty subjects including both normal and diabetic subjects were investigated in this study. Comparing normal and diabetic subjects, we found amplitude parameter was most important factor to classify subjects by normal and diabetic.

Since modeling of the oscillatory potential and the estimation of the model parameters were our final goal, we haven't proposed to …

Object Oriented Design Of Petri Net Simulator, Himanshu Juneja

Theses

Petri nets are highly useful for modeling discrete event dynamic systems. The objective of this effort is to develop a tool for drawing, editing and simulating Petri nets using object oriented programming on a standard platform. The object oriented approach was chosen because of its code reuse and extendability features which simplify the task of adding features to the tool as the model evolves. The design stresses on modeling of the problem by objects which closely relate the system design with the implementation.

C++ is used for implementing the object oriented design, and the XView toolkit is used for building …

The Development Of A Senior Unit Operations Laboratory On The Supercritical Extraction Of Solid Naphthalene With Supercritical Carbon Dioxide, Ronald G. Gabbard

Theses

A Senior level Undergraduate Unit Operations Laboratory experiment was developed for the extraction of Naphthalene with supercritical Carbon Dioxide. A Supercritical Extraction Screening System purchased from Autoclave Engineers of Erie, Pennsylvania was modified slightly for use as the laboratory equipment. The experiment consists of extracting solid naphthalene from a sand bed in a fixed bed extractor and determining the mass transfer coefficient for the unit.

The lab has been designed to allow the students to develop their own experimental plan without much direct input. The experimental outline provided for the students primarily focuses on information needed for safe and proper …

Simplification Of The Generalized Adaptive Neural Filter And Comparative Studies With Other Nonlinear Filters, Henry Steven Hanek

Theses

Recently, a new class of adaptive filters called Generalized Adaptive Neural Filters (GANFs) has emerged. They share many characteristics in common with stack filters, include all stack filters as a subset. The GANFs allow a very efficient hardware implementation once they are trained. However, there are some problems associated with GANFs. Three of these arc slow training speeds and the difficulty in choosing a filter structure and neural operator.

This thesis begins with a tutorial on filtering and traces the GANF development up through its origin -- the stack filter. After the GANF is covered in reasonable depth, its use …

Processing And Application Of Polyolefin Plastics, Muhammad Khalid

Theses

This thesis describes the manufacturing, processing and application of polyolefin thermoplastics. Polyolefins have become one of the most important kinds of plastics. Polyolefin resin represents about one third of all plastics sold and its application for films and containers dominate the packaging industry. The objective of this thesis is to present the various processing methods and application of polyolefin thermoplastics. Polyolefin is produced by several different processes. Conventional low density polyethylene is made by polymerizing ethylene at high pressure and high temperatures while high density polyethylene is polymerized at relatively low pressure and low temperatures. Generally all polyolefin possess excellent …

Development Of An Intelligent Geometry Measurement Procedure For Coordinate Measuring Machines, Tae-Sung Kim

Theses

A Coordinate Measuring Machines (CMM) is a highly accurate electronic scale for the automatic measurement of 2 and 3 dimensional geometries. In a typical operation the CMM measures a set of user defined points, and then utilizes some internal logic to ascertain whether the inspected part meets the specifications. CMMs have received widespread acceptance among the manufacturing community, and in many instances are required as per supplier contract. Applications of CMMs vary from the measurement of simple 2D parts to complex 3D spatial frames (as for example in their use to measure the integrity of automobile frames). The primary objective …

Vibratory Size Segregation Of Particulate Matter, Anthony La Rosa

Theses

Size segregation imposed by vibration or shaking is an ubiquitous phenomenon whereby a large particle will rise to the top of a bed of smaller spheres upon vibration. Several mechanisms based on computer simulations have been proposed, however a complete theory remains elusive. The objective of this study was to perform experiments to study vibratory segregation of particles for varying size ratios and vibration parameters. More specifically, the rise time of a sphere from the bottom to the top of a vibrated bed was examined. It was found that the rise time decreased with an increase in amplitude for fixed …

Magnetohydrodynamic Behavior Under Current Impulse Excitation, Shi Wu

Theses

The effects of magnetic field on magnetohydrodynamic (MHD) channel flow between two parallel plates of infinite extent are investigated. The applied magnetic field is due to an infinite impulse current-carrying conductor located a small distance below the lower channel wall. Influence of the induced magnetic field, such that the magnetic Reynolds number (R_m) is less than unity but greater than zero, is included. The solution is obtained using the perturbation theory in the expansion of the field components in a double-power series in R_m and I. Calculations for the magneto-fluid components were carried out using personal computer. …

Experimental Investigation Of Submerged, Turbulent, Axisymmetric Air Jet Impinging On A Flat Plate, Lan Xiao

Theses

Experimental investigation was carried out on the flow characteristics of a circular, submerged, turbulent, axisymmetric air jet impinging normally on a smooth, flat, square, Lucite plate and a sand paper covered plate. Jet issuing from a circular nozzle of 0.5 inch diameter while the Reynolds Number varying from 10,000 to 85,000 was investigated. The flow can be considered incompressible since the pressure and the velocity of the jet were not too high, with Mach Number of the order of 0.3.

Various flow parameters were measured to obtain the velocity and pressure distributions at the surface of the flat Lucite plate, …

Synthesis And Characterization Of Silicon Nitride Films Deposited By Plasma Enhanced Chemical Vapor Deposition Using Diethylsilane, Yanyao Yu

Theses

Silicon nitride thin films were deposited on silicon substrates using Diethylsilane (DES) and ammonia by Plasma Enhanced Chemical Vapor Deposition (PECVD) over a temperature range of 100 - 300°C, a pressure range of 0.2 - 0.6 torr, and a ratio of NH₃/DES was varied from 6 - 26. The R.F. power and frequency were kept at 0.15 watts/cm^{2 and 100 KHz respectively. DES flow rate was set at 15 sccm for all experiments in this study. One set of experiments were performed at different values of one parameter while the other parameters were kept constant.}

The deposition …

Local Stress Factors Of Pipe-Nozzle Due To Radial Load, Circumferential And Longitudinal Moments, Junyu Lin

Theses

This thesis presents a series of stress factor data which provide more detailed information for the calculation of local stresses at the nozzle region, as well as the pipe region, of a pipe-nozzle intersection, subjected to an external radial load, circumferential bending moment, and longitudinal bending moment, respectively.

The pipe and nozzle thicknesses are assumed to be identical. Numerical solutions are obtained through the use of the finite element method. In obtaining the numerical solutions via ANSYS, the quadrilateral element is used to simulate the thin shell pipe-nozzle geometries. The local stresses, at eight different points on both the pipe …

Investigation Of The Pl Cebus Performance With And Without Acknowledgment, Menghan Pan

Theses

The power line implementation of the consumer electronic bus (PL CEBUS) is a promising and inexpensive approach for home automation. Since the intro¬duction of the PL CEBUS standards, there has been increasing efforts on evaluating its performance. However, all the works have been performed for unacknowledged networks. This thesis presents the first successful evaluation of the PL CEBUS with acknowledment. Three different cases, namely, 600, 300 and 100 bits packet sizes, have been considered. The evaluation included the simulation of performance parameters such as message and packet delays, message throughput, and channel throughput. Acknowledged network performance has been confirmed to …