Engineering Commons^™

The Collapse Of The Cypress Viaduct During The Loma Prieta Earthquake Of October 17, 1989, Mohamed M. Eid

Theses

The Loma Prieta earthquake of October 17, 1989 in California was one of the most disastrous earthquakes in U.S history. It caused damage to commercial, residential, and industrial structures, transportation and utilities.

This study includes investigations about the Cypress Viaduct collapse re?ported by:

1. California Governor's Board of Inquiry [4].
2. National Institute of Standards and Technology (NEL) W.
3. 3The Author.

Investigators in the first report concluded that the collapse was due to horizontal ground motion. In the second one, it was due to the vertical ground motion.

In the author's investigation, a detailed static and dynamic analyses are performed to determine …

Shop Floor Planning And Control In Integrated Manufacturing Systems, Tahir Mahmood

Theses

The implementation of a shop floor planning and control system is a prerequisite in establishing an effective computer integrated manufacturing system. A shop floor control system integrates management production goals with the capabilities and limitations of the manufacturing plant. Shop floor planning begins with a long term rough cut capacity plan and evolves into near term, capacity requirements and input/output plans. Shop floor control provides a status of in-process operations and a measure of the plants success in executing the plan. Effective use of technology on shop floor increases the efficiency of the manufacturing plant. Simulation is an important tools …

An Information Theoretic Approach To Dsn Evaluation, Vivek Mehrotra

Theses

Evaluation of Distributed Sensor Networks (DSN's) for optimal detection using Bayesian cost formulation methods has been the objective of several studies. There have been a few studies on DSN evaluation using an information theoretic approach, wherein an assymetric channel models a detector. We look at the multi-sensor system at the receiver as a black-box and model it as an assymetric channel whose cross over probabilities depend on the probabilties of detection and of false alarm. These probabilities in turn depend on the thresholds of the local detectors and on the fusion rule used. We consider the case wherein the receiver …

The Design And Manufacture Of Institutional Trays Using Simultaneous Engineering, Antonio Schmidt

Theses

This study evaluates thermoformed trays as used in the food service industry. The resin used in fabricating trays is a blend of Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate (PC). The life of the trays is presently between 1 to 3 years. The trays are used in correctional facilities and hospitals. The handling of the tray is not abusive. The trays are pulled out of service once they exhibit stress cracking.

To further understand the unpredictable life of the thermoformed trays an understanding of the behavior of the plastics is required and the method of comparing one resin from another, as …

Three-Dimensional Beam-Columns, Mohammad Hassan Shams

Theses

This thesis explores several special cases of three-dimensional beam-columns and suggests that the method of finite differences can be used when a solution of general case is required. The thesis begins with a review of the three-dimensional beam-column equations and then shows how these equations can be used to generate the member stiffness matrix for the nonlinear analysis of three-dimensional frames. Examples are included which discuss the differences between the analytical and numerical solutions.

Application Of Desktop Manufacturing System (Sla) For The Manufacturing Of A Centrifugal Pump Impeller Using Cad (I-Deas), Wasimuddin Azam Muhammad Syed

Theses

Desktop Manufacturing (DTM) systems which combine personal computer, laser and other technologies are being used to sculpt objects from computer generated models created on computer aided design (CAD) workstations. As a member of DTM systems, StereoLithography Apparatus (SLA) transforms 3-dimensional designs into a 3-D output. This can substantially reduce the time required to produce a prototype through the process of photopolymerization. The process involves the transfer of a liquid plastic monomer into a solid polymer by exposing it to ultraviolet light.

Although the process looks productive, inefficiencies can occur, if incorrect parameters are selected before its application for a particular …

Catalytic Ozone/Ultraviolet Light Oxidation Of Organics In Water : Integrated Charcoal/Ozonation/Uv Radiation, Dawei Wang

Theses

A novel heterogeneous catalytic-oxidation technology where activated carbon is used as a catalyst-adsorbent, ozone serves as the oxidant and UV light as activation agent, is developed in a lab scale study. We demonstrate this process for destruction of recalcitrant organics in water i.e: combined oxidation by ozone, UV light plus activated carbon. The investigation includes evalution of various operating conditions: ozone levels, activated carbon levels; time for complete destruction of the individual target pollutants, plus evalution of activity of the continuously recativated carbon surface in-situ. All experiments were performed at room temperature in a semi-batch reactor. Seven representative chemicals was …

Bragg Reflection Grating Waveguide, Wei Zhong

Theses

Bragg reflection waveguides (BRW) are non-conventional optical guides in which optical confinement is achieved via periodic set of grooves or stratified media along the guiding path. BRW may also serve as optical filters, because of spectral discrimination of the guiding process. A novel UV laser ablation technique was used in this thesis to fabricate periodic metal-clad polymeric waveguides. Spin-on technique was applied to fabricate the waveguide core on glass substrates, evaporation of metal film and selective ablation process defined the optical guides. Various periodicities have been fabricated and the near field patterns have been measured to compare the different guiding …

The Durability Of Hot Mix Asphalt With Petroleum Contaminated Soils, Bonnie H. Dubose

Theses

Petroleum contaminated soils are considered solid waste They must be taken to solid waste facilities such as landfills or some other method must be found to deal with them. Landfills are becoming limited and is looked upon by the government as the least attractive option. One method that looks promising is to use petroleum contaminated soils in Hot Mix Asphalt Concrete.

In the research program the following are examined: 1) Investigation of material properties of the petroleum contaminated soil and aggregates 2) The proper procedure to produce a design blend of asphalt concrete. 3) Establishing the test procedure protocol to …

Automatic Surface Mount Solder Joints Inspection, Zhu Liu

Theses

This thesis reports the research results on automatic inspection of solder joints on printed circuit boards. The previous work on this subject has been advanced significantly in the following three aspects. With the support of AT&T Bell Lab, the most updated surface mount solder joints are inspected in this work instead of larger simulation solder joints or traditional through hole solder joints in the previous work. A small set of features is extracted for surface mount solder joints in both infrared and visual light inspection. A new image processing software named Khoros has been applied to improve the quality of …

Posterior Stabilized Knee Design Biomechanical Considerations, Donald E. Mcnulty

Theses

Numerous posterior stabilized knee systems are available for primary and revision total knee arthroplasty. Design of these systems requires an understanding of the articulating geometries and kinematic/kinetic biomechanical considerations of the normal knee. The findings for the normal knee are integrated into the design of a prosthetic system.

The natural femoral, tibial and patella articulating geometries are defined to enable subsequent kinematic and kinetic analyses. The articulating geometries are characterized from review of anthropometric studies of the tibiofemoral and patellofemoral joint.

The kinematic analysis of the natural knee defines knee motion in terms of rotation, adduction/abduction, range of motion and …

Computation Of Collision Parameters Of Spheres By Computer Vision, Sumit Sen

Theses

Collision parameter evaluation of rigid spherical particles requires estimation of pre- and post-impact position, velocity and angular velocity vectors of colliding particles. A three dimensional experimental technique is devised where the instantaneous position and orientation of the particles are determined by analyzing frames obtained through high speed video imaging system. Since the image obtained is two dimensional, a mirror setting is designed to capture two orthogonal views of collision in order to estimate motion in depth. The translational velocity vector is determined from the position information extracted through application of available image analysis techniques over two time frames of digitized …

Modeling, Evaluation, And Control Of A Flexible Manufacturing Cell Using Petri Nets, Glenn Arthur Thorniley

Theses

This thesis describes the usefulness of Petri nets in modeling, evaluating, and controlling a Flexible Manufacturing Cell (FMC). The basics of Petri net theory are explained and a specific FMC is examined. First, the FMC is modeled. The purpose of modeling is to facilitate the evaluation and provide a framework on which the control methodologies can be applied. The objective of the evaluation is to determine how the FMC would benefit most by replacing or adding equipment. Several ideas on control are combined to form a useful framework for the designing of the control net. With this framework the control …

Modification, Reimplementation And Studies Using The Meisner Model Of The Heart, Ari Zvi Zivotofsky

Theses

The study of left ventricular filling in both the normal and the pathological heart is of great importance. A computer model simulation of the heart with emphasis on mitral flow was designed by Meisner in 1986 and implemented in QuickBASIC. This paper discusses how the original program was altered to be able to perform "Parameter vs. Parameter" runs in which it can be observed how varying an input parameter affects output parameters. The output data is then formatted in such a way that it can be used by QUATTRO PRO, a standard spreadsheet package, to yield graphical outputs.

In addition, …

Investigation Of Waterjet-Workpiece Interaction, Hung-Yuan Li

Dissertations

The objective of this research is to develop new knowledge related to the fundamental physical phenomena of waterjet machining of ductile materials, and to use this knowledge to construct a numerical analysis model. The resulting knowledge will enable enhancement of waterjet cutting efficiency.

Experimental study of fundamental mechanisms and the acquisition of the data detailing micro and macro scale phenomena which occur during the machining process is carried out. It is shown that the material damage mechanism associated with waterjet machining is erosion cavitation which initiates ultrasonic stress wave propagation in the workpiece. Fatigue, an important element in producing material …

Development Of Prediction Technique For The Geometry Of The Abrasive Waterjet Generated Kerf, Yichung Chung

Dissertations

This study is concerned with the development of a practical and accurate technique for off-line determination of the variables characterizing the macro-geometry of the kerf generated in the course of abrasive waterjet (AWJ) machining of ductile materials. The study involved generation and processing of a database relating operational conditions with kerf dimensions. The total number of generated samples exceeded 1500.

A physical model relating the process results with operational conditions was constructed and used for the selection of a statistical technique for analysis of the acquired experimental information. The semiempirical model developed here is based on a simple theoretical model …

Kinetic Studies Of Photo-Initiated Oxidation Of Toxic Organic Pollutants Including The Formation And The Destruction Of Intermediates, Yuan-Shen Li

Dissertations

The photo-initiated oxidation process, using hydrogen peroxide or ozone under ultraviolet radiation, has been proven to be an effective treatment method for toxic organic pollutants in wastewater. Most of the recent kinetic studies of the process were concentrated on the breakdown mechanisms of the pollutant itself. The formation and the destruction of intermediates were seldom investigated. Also the mechanisms and their reaction rate constants of free radical formation and destruction in the O₃/UV or H₂O₂/UV reactor were seldom studied.

The objective of this research is to study the kinetics of photo-initiated oxidation of toxic …

Performance Evaluation Of Spread Spectrum System With Cochannel Interference Through A Nonlinear Channel, Yong H. Kim

Dissertations

This thesis deals with the problem of more than one subscriber transmitting data signals through a common satellite repeater using code division multiplexing to separate the signals. We are concerned with the problem of amplifying two DS spread spectrum signals, both QPSK or BPSK modulated, in a common device in which limiting occurs. One signal is considered the signal we desire to receive, and the other, having the same nominal carrier frequency with a small random offset, is considered to be a cochannel interferer. The case of a cochannel interferer on the uplink and downlink in QPSK signalling and BPSK …

Particle Dynamics Modeling Of Boundary Effects In Granular Couette Flow, Hyeong-Jin Kim

Dissertations

This study provides insights in understanding boundary effects on the flow of dry granular materials composed of identical, smooth, inelastic spheres between parallel, bumpy walls in the absence of gravity. The results of this study are useful in providing a basis upon which developing theories can be modified as well as substantiating previous and current experiments. This in turn has a major importance in many industries which are concerned with handling of particulates, such as coal, mineral processing, powder metallurgy, and agriculture.

The particle dynamics or discrete element method is used to model this flow, thereby providing a means of …

Structural Reliability Using Finite Element Method, Che-Chen Liou

Dissertations

During the last decade, structural reliability theory has been treated in a large number of research papers; therefore, from being a subject only well known by a relatively small number of researchers, it has become an important engineering discipline. From the application point of view, many practical applications have been made successfully.

In this dissertation some important fundamental concepts in statistics and in reliability theory are presented. The concept of failure mode can be defined as: A set of failed elements turn a structure into a mechanism. Usually, a structure has many possible failure modes; therefore, it will be necessary …

A Modified Approach To Flood Prediction In Urban Watersheds, Joseph Ofungwu

Dissertations

The purpose of this dissertation was to develop a better method for dealing with the problems of flood prediction in Urban Watersheds. It has long been realized that urbanization activity such as increased imperviousness, drainage improvements, etc. increases runoff volumes. Therefore, traditional flood prediction methods using the Log Pearson III distribution underestimate flood frequencies when applied to urban watersheds without modification.

In attempt to compensate for the effects of urbanization on streamflow, previous workers usually employed regional analysis techniques involving a number of different watersheds at various degrees of urbanization. Results obtained by this approach leave room for improvement primarily …

Process Technology And Characterization For Field Emission Devices, Jong Min Kim

Dissertations

Vacuum microelectronics is a new research field which applies semiconductor process technology to the fabrication of micron-dimensioned electron devices. Vacuum microelectronics is made possible by advances in microstructures and nanofabrication technology. Vacuum microelectronic devices are further characterized by a wide operating temperature range, nuclear radiation immunity, higher emission current density potential, and lower power consumption than that of thermionic emitters. The low mass of the electron provides a higher carrier mobility than GaAs or any solid state device. These features offer the potentials for wide variety of applications.

In this dissertation. electron field emission structures applicable to a variety of …

Investigation Of Epitaxial Lift-Off Gaas And Langmuir-Blodgett Films For Optoelectronic Device Applications, Divyang M. Shah

Dissertations

Epitaxial lift-off (ELO), a technique of removing an epitaxially grown GaAs layer from its growth substrate by selective etching of an AlAs sacrificial layer, is described for field-effect transistor fabrication independent of the GaAs growth substrate. Metal Semiconductor Field-Effect Transistors (MESFETs) and High Electron Mobility Transistors (HEMTs) fabricated on silicon and sapphire substrates using ELO are investigated. A 0.1 μm gate length depletion mode MESFET made on silicon exhibited a unity current gain frequency f_t = 34 GHz. Excellent device isolation with subpicoampere leakage currents is obtained. A high input impedance amplifier has been implemented on silicon substrate using …

Thermal Desorption And Decomposition Of Hazardous Organic Compound I: Mass Transfer Of Benzene And Chlorobenzene In Soil Matrices Ii: Oxidation And Pyrolysis Of 1,1,1-Trichloroethane In Methane/Oxygen/Argon, Yo-Ping Wu

Dissertations

I: Mass Transfer of Benzene and Chlorobenzene in Soil Matrices

Experimental measurements on several apparatus were used in conjunction with chromatographic theory to study the thermal adsorption and desorption of organic vapors on soil with different particle sizes for analysis mass transfer parameters and heat of adsorption. Benzene (C₆H₆) and chlorobenzene (C₆H₅Cl) were tested on soil with 0.55, 0.46, 0.36, and 0.225 mm average particle sizes. Sample injection volumes for organic compounds were studied to ensure linearity of gas chromatography. Equilibrium constants were strongly dependent on temperature but not on particle size. …

Pure Strong Competition For Two Microbial Populations In A Chemostat, Efthimios Ioannis Banias

Theses

The dynamics of pure, strong, double competition between two microbial populations in an ideal chemostat have been investigated by using mathematical and numerical analysis. The two nutrients competed for have been assumed to be complementary for both competitors. Inter active models have been used for the specific growth rates. Two cases have been considered; one in which neither of the two substrates exerts inhibitory effects on the growth of either one of the competing populations, and one in which the growth of one population is inhibited by only one of the two substrates. The primary focus of this investigation was …

The Study Of Activated Sludge Settleability Using The Solids-Flux Analysis, Churng-Cherng Lin

Theses

The activated sludge was cultivated in two pilot-scale activated sludge systems under three ratios of BOD to N, equal to 20:1, 70:1 and 300:1 in the influent wastewater. The aeration tank of the activated sludge system was constructed in two different configurations: one without compartments in the tank, the other consisting of six compartments. The activated sludge withdrawn from the last compartment of each system was tested in a one-liter graduate cylinder to measure its zone settling velocity. The solids-flux method was employed to analyze the sludge settling characteristic as a function of solids concentration. The results show that the …

Design For Quality Manufacture : Formulation Of The Macro Architecture For A Dfqm Methodology, Shrad Prasad

Theses

The focus of the available techniques in concurrent engineering for the development and improvement of the design of a product, has been in the areas of product assemblability and manufacturability. These techniques are concerned with the reduction of the cost associated with the manufacture and handling of the product.

The Design For Quality Manufacturability focuses on the quality manufacturability issue of the product design. A macro architecture is developed for the introduction of a new methodology to evaluate designs based on the quality manufacturability of these designs. A set of defects occurring at the assembly stage of the manufacture of …

Optimization Of A 3-Micron Bccd Process For High Density Ccd Registers, Mark Ratner

Theses

In July 1991, Dr. Walter F. Kosonocky proposed a High-Frame-Rate-CCD Imager. The design of the imager is such that the CCD channel width be 3-microns and capable of handling at least 3000 - 5000 electrons per square micron. Using process (SUPREM III) and device (PISCES IIB) simulations, charge handling capacities as a function of implant energy and junction depth were studied. Arsenic implants ranging from 100 to 200keV were driven-in to obtain junction depths between 0.40µm and 0.80µm. As a result of this work it was determined that charge handling capacities as high as 9400 electrons/µm² were achievable with …

Comparing Techniques Of Mapping Pyramid Algorithms Onto The Hypercube : A Case Study For The Connection Machine, Muhammad Ali Siddiqui

Theses

The pyramid structure is most widely used for low-level and intermediate-level image processing and computer vision because of its efficient support of both local and global operations. However, the cost of pyramid computers (PC) may be very high. They also do not support the efficient implementation of the majority of the scientific algorithms. In contrast, the hypercube network has widely been used in the field of parallel processing because it offers a high degree of fault tolerance, a small diameter and rich interconnection structure that permits fast communication at a reasonable cost. Thus, several algorithms have been developed for the …

Ultrasonic Ranging System For Gait Analysis, Mu Wu

Theses

A new method of measuring range for gait analysis is described. The method is based on a coherent measurement of the phase shift of an ultrasonic signal as a function of range.

A prototype of the ranging system was breadboarded, tested, and found to have a relative accuracy of better than 0.5 mm over a range of 3 meters. The maximum range the system is at least 20 meters. The method used here is new and has not been found in the literature. Tt is demonstrated by experiments with a prototype system that can measure distance with a higher accuracy …