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 …

Electrorheological Fluids And Their Application In Automotive Clutches: Design Procedures And Recommendations, Ihab Fahmy

Archived Theses and Dissertations

No abstract provided.

Behavior Of Concrete Masonry Prisms Under Axial Compression, Tarek Ghoneim Mohamed Ghoneim

Archived Theses and Dissertations

No abstract provided.

A Nonlinear Three-Dimensional Micromechanics Model For Fiber-Reinforced Laminated Composites, David D. Robertson

Theses and Dissertations

In this study, a three-dimensional micromechanics model is developed. The present capabilities of the model include both unidirectional and laminated composite layups with various types of nonlinear analysis such as a thermoelastic-plastic analysis employing the Prandtl-Reuss flow relations, a thermoviscoplastic analysis using Bodner-Partom unified constitutive theory, and an interfacial damage progression scheme based on a statistical interfacial failure criteria. Such nonlinearities are critical factors during thermomechanical fatigue TMF loading of high temperature composites. Solutions were obtained and extensive comparisons performed with existing micromechanics models, finite element analysis, and experiment with excellent results. In addition, the analysis was developed to require …

Crew Scheduling Of Space Operations Squadrons (Sops), Marianne Idzi

Theses and Dissertations

The mission of Space Operations Squadrons is continuous support of military satellite systems. The scheduling problem associated with conducting continuous operations is threefold. The first problem is finding cyclical crew shift schedules that meet daily manning requirements, adhere to current regulations, contain a minimum number of workshift changes during consecutive duty days, and maximize the non-duty time allowed between duty shifts. The second problem is to establish a sea of criteria to evaluate alternative shift schedules. Finally, the third problem is to minimize the number of personnel required to meet the scheduling requirements stated in the first problem. This study …

The Application Of Simulated Annealing To Stochastic Systems, Charles B. Warrender

Theses and Dissertations

Simulated Annealing was used to optimize three constrained simulation models. For each of these models, seven different acceptance functions were evaluated and compared against the performance of Local Search. These comparisons demonstrated the affect that different acceptance functions have on the performance of the algorithm. The performance was measured by the average solution quality and average efficiency obtained from several runs. The first model facilitated the implementation of Simulated Annealing using the SLAM simulation language. The configuration space was small, described by only two decision variables. It demonstrated the viability of using Simulated Annealing to optimize the variable settings in …

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 …

A High-Temperature Pressure Sensor Utilizing Linear Voltage Differential Transformer (Lvdt) And Silicon Wafer-To-Wafer Fusion Bonding Technologies, Robert Sylvester Okojie

Theses

A novel high-temperature pressure sensor was designed based on the principle of magnetic induction. The device is meant to correct the problems inherent in conventional Solid-State pressure transducers such as piezoresistive and capacitive at temperatures above 300°C. Prominent among these problems are increased leakage current, reduced absolute sensitivity, redistributed impurity concentration profile, and thermal mismatch.

This thesis combined the Biot Savart magnetostatic principle and the theory of deflecting clamped circular plates to obtain the microelectromechanical relationship. The problem of thermal mismatch was resolved by the symmetrical layering of a Si₃N₄/TaSi₂/Si₃N₄ sandwich, …

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. …

Evaluation Of Collision Properties Of Spheres Using High-Speed Video Analysis, Jian Yu

Theses

Experimental evaluation of the collision properties of spheres is performed using video image analysis techniques. A high-speed Kodak EktaPro1000 video camera is utilized to record a collision sequence between two spheres at 1000 frames/sec, and then the images are analyzed to calculate three dimensional translation and rotation before and after the collision. These quantities are used to compute the collision properties for a pair of one inch nylon spheres, i.e. the coefficient of friction, and the coefficients of normal and tangential restitution. The focus of the thesis is on image analysis techniques that provide high accuracy results even though the …

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 …

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 …

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 …

A Parallel Processing Architecture For Dqdb Protocol Implementation, Nilesh Vinubhai Gandhi

Theses

The high bandwidth transmission links, which have been provided by the advances of Fiber Optics Technology, reduce drastically the packet transmission times and place new demands on the nodal protocol processing. Segmentation and reassembly of packets, computation of checksums, introduction of source and destination addresses, etc., must be performed extremely fast in order to prevent node processing from becoming the bottleneck of the transmission. Parallel processing enables the execution of the previous tasks on multiple packets simultaneously and therefore has the potential of addressing the issue of fast node processing successfully. In this thesis we focus on the Medium Access …

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 …

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 …

Modeling Of Rapid Thermal Processing System By Finite Element Method, Helen Martynov

Theses

A finite element model for the Rapid Thermal Processing (RTP) system at NJIT was developed based on the software package MSC/NASTRAN. Based on this model, a thermal analysis of the 9" chamber, 3 zones (37 lamps) RTP system was conducted for various modes of system operation with the 6" silicon wafer temperature varying from 300°K to 1100°K. An open-loop control algorithm was developed in order to study the dependence of wafer temperature on time, position, and applied radiant heat distribution. It was shown that the non-uniformity in the radial temperature profile can be less than 3°C during wafer heating at …

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 …