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Theses/Dissertations

1995

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Articles 31 - 60 of 333

Full-Text Articles in Engineering

Linearly Tapered Slot Antenna, Luis Alberto Tumialan Dec 1995

Linearly Tapered Slot Antenna, Luis Alberto Tumialan

Theses

Design procedure for Linearly Tapered Slot Antennas (LTSA) has been developed and implemented using High Frequency Structure Simulator (HFSS) code based on a finite-element analysis.

A CAD study of two variations of a LISA based on either a stripline or a microstrip feed has been carried out. Circular and radial stubs have been considered in these designs for an antenna operating at 10 Ghz. LTSA on a Duroid substrate fed by a stripline has been designed to operate with better than 12 dB return loss. Fabricated antenna was characterized and had even a wider response than the CAD design. Radiation ...


Minimization Of Sum-Of-Conditional-Decoders Structures With Applications In Finite Machine Epld Design And Machine Learning, Sanof Mohamedsadakathulla Dec 1995

Minimization Of Sum-Of-Conditional-Decoders Structures With Applications In Finite Machine Epld Design And Machine Learning, Sanof Mohamedsadakathulla

Dissertations and Theses

In order to achieve superior speed in sequencer designs over competing PLD devices, Cypress brought to market an innovative architecture, CY7C361. This architecture introduced a new kind of universal logic gate, the CONDITION DECODER (CDEC). Because there are only 32 macrocells in the chip, saving only one CDEC gate can be quite important (the well-known "fit/no-fit problem"). A problem that is related to the fitting problem of the Cypress CY7C361 chip is the SOC Minimization. Due to the limited low number of macrocells in CY7C361, a high quality logic minimization to reduce the number of macrocells is very important ...


An Examination Of Railroad Capacity And Its Implications For Rail-Highway Intermodal Transportation, David Bruce Clarke Dec 1995

An Examination Of Railroad Capacity And Its Implications For Rail-Highway Intermodal Transportation, David Bruce Clarke

Doctoral Dissertations

After many years of decline in market share, railroads are now experiencing an increasing demand for their services. Service intensive intermodal transportation seems to be an especially promising market area. Since the historic decline in traffic has been accompanied by a reduction in network infrastructure, however, the railroads' ability to handle sizable traffic increases, at least in the short term, is in question. Since rail transportation is critical to the domestic economy of the nation, and is increasingly important in international logistics channels, shortfalls in railroad capacity are not desirable.

The published literature on railroad capacity is relatively sparse, especially ...


Monitoring And Prognosis Of Plant Components, Jeffrey Banks Dec 1995

Monitoring And Prognosis Of Plant Components, Jeffrey Banks

Masters Theses

Many predictive maintenance approaches focus primarily on fault monitoring and diagnosis of rotating machinery. Today's industrial "reliability-based" maintenance programs implement vibrational analysis techniques as a sound foundation in minimizing unnecessary machine downtime. These approaches, based upon on-line data acquisitions and analysis may be used to increase component availability and ultimately forecast remaining life. Depending upon the specific type of machinery under consideration, measurements such as temperature, voltage, current, rotational speed, power, and torque may be analyzed to enhance machinery diagnostics capability.

The purpose of the proposed research is to formulate and implement a methodology to estimate the remaining useful ...


An Investigation Of Turbulent Taylor-Couette Flow Using Laser Doppler Velocimetry In A Refractive Index Matched Facility, Joseph C. Parker Dec 1995

An Investigation Of Turbulent Taylor-Couette Flow Using Laser Doppler Velocimetry In A Refractive Index Matched Facility, Joseph C. Parker

Master's Theses

Turbulent Taylor-Couette flow between an annulus formed by two concentric cylinders with dead end walls is comprised of complex patterns of vortices. An experimental apparatus was designed to provide refractive index matching between the annulus and working fluid. Optical access was maintained through three sides of the annulus and one end wall. An aqueous solution of sodium iodide was formulated to match the refractive index of the Plexiglas annulus. Laser Doppler Velocimetry was used to measure the three components of velocity and turbulence intensity throughout a planar section in the annulus. The annulus dimensions were: ƞ= 0.672, d = 15 ...


The Effect Of Rotor Wake/Exit Guide Vane Interaction On The Total Pressure Losses In An Airfoil Cascade, Aaron Mosebach Dec 1995

The Effect Of Rotor Wake/Exit Guide Vane Interaction On The Total Pressure Losses In An Airfoil Cascade, Aaron Mosebach

Master's Theses

Computational simulations have been performed to study the effects of unsteady rotor wakes on the total pressure losses and the boundary layer characteristics in a compressor cascade. In the numerical simulations, transitional and turbulent flow conditions were modeled at design and off-design inlet flow angles, and for varying rotor wake widths and wake velocity deficits.

First, simulations were performed in the absence of rotor wakes at the inlet of the EGV (Exit Guide Vane) cascade. Second, simulations were performed for different wake width and wake velocity deficit values at the inlet of the EGV cascade. The majority of the numerical ...


Application Of Pulse Calorimetry To Metal Systems, Debasis Basak Dec 1995

Application Of Pulse Calorimetry To Metal Systems, Debasis Basak

Doctoral Dissertations

The pulse calorimeter developed as a part of the author's masters thesis was used extensively in the doctoral research to determine the electrical resistivity and specific heat of Ni, Ni4Mo, Fe-A1 alloys and Ni-A1. The temperature range of measurements varied with different specimens but in general were between 375 K to 1300 K.

The pulse calorimeter essentially consists of a specimen in series with a standard resistor and a programmable power supply. The specimen is inside a vacuum chamber. The programmable power supply can be triggered from the computer to send a specific current to the specimen ...


Activation Of Precipitated Iron Fischer-Tropsch Catalysts, Mehul D. Shroff Dec 1995

Activation Of Precipitated Iron Fischer-Tropsch Catalysts, Mehul D. Shroff

Chemical and Biological Engineering ETDs

The Fischer-Tropsch Synthesis (FTS) is an important step in the manufacture of synthetic fuels from coal. The use of iron catalysts for FTS, though desirable from the standpoint of process economy, is hampered by problems relating to catalyst attrition and carbon buildup. In addition, from a research perspective, there has been a long-standing controversy in the literature with regard to the nature of the active phase.

The effect of activation and reaction treatments on the resulting phase transformations in a commercial, precipitated and spray-dried, Fe2O3 - CuO - K2O Fischer-Tropsch catalyst have been studied. Different catalyst batches ...


Personality As It Relates To Performance Among Primary Flight Students At Embry-Riddle Aeronautical University, Caroline F. Farmer Dec 1995

Personality As It Relates To Performance Among Primary Flight Students At Embry-Riddle Aeronautical University, Caroline F. Farmer

Theses - Daytona Beach

The purpose of this study was to evaluate the relationship of primary flight students' performance as it relates to personality. Previous research has provided the basis for the relationship between what an individual accomplishes and personality traits. The individual performance of 30 students were evaluated by two different techniques during an observer flight. One was an evaluation form developed by the researcher and the other, the flight instructor's (P.I.C.) evaluation. The performance data gathered by the researcher was collected in order to provide a secondary set of performance data in case there was no discriminability amongst the ...


Compressible Flow Analysis Of Thrust Augmenting Ejectors, Mohamed Moujahid Dec 1995

Compressible Flow Analysis Of Thrust Augmenting Ejectors, Mohamed Moujahid

Theses - Daytona Beach

The present work was initiated due to the need for a method to understand and predict the thrust augmenting characteristics of jet ejectors. The mixing process in ejectors can be analyzed using either the control volume approach, or detailed models based on the Navier -Stokes Equations and the theory of turbulent jets. The control volume approach uses integrated forms of the conservation equations of mass, momentum and energy. It is chosen in the first part of the study since it affords the best vehicle for the parametric studies required to understand the potential of ejectors for a given application. Compressibility ...


Cumulative Average Pricing Method For Estimating Average Service Life, Mahendra Babu Hosangadi Dec 1995

Cumulative Average Pricing Method For Estimating Average Service Life, Mahendra Babu Hosangadi

Master's Theses

The study determined if accuracy of estimation of retirement price of industrial equipment was affected by using a cumulative average pricing (CAP) method at varying conditions of inflation rate, service life, and life characteristics. The study also determined the accuracy of estimating the average life of unaged data by simulated plant record (SPR) method. Thirty-six experiments were conducted at varying conditions of inflation rate, curve type and average life. The study was conducted for two left modal curves, two symmetrical modal curves and two right modal curves at 20 and 40 years average life using three different inflation rates: 3 ...


A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare Dec 1995

A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare

Master's Theses

Over a two year period, Western Michigan University ran a number of pump tests in the Asylum Lake Area in Kalamazoo, Michigan. The transmissivities and storativities calculated from these tests differed significantly from well to well in any particular test, and from pump test to pump test. Utilizing the computer programs AQTESOLV 3.0 and Aquifer Parameter Estimator, a number of T and S values were calculated. After analysis of the results, the following conclusion was drawn. The main reason for the deviations in the T and S values arose from the mixing of the results of numerous methods (some ...


Dynamic Pulse Buckling Of Columns With Viscous Damping, Murli Kadandale Dec 1995

Dynamic Pulse Buckling Of Columns With Viscous Damping, Murli Kadandale

Master's Theses

This is a study of dynamic pulse buckling of columns with viscous damping. The differential equations of motion were obtained using the Bemoulli-Navier hypothesis. The effects of axial and rotary inertia were included in the analysis. The Voigt-Kelvin model for a viscoelastic material is used. The Finite Difference Method was employed to solve the differential equations of motion. First columns without geometrical imperfections were studied, and a correlation between the damping modulus and the more familiar damping ratio was obtained. Then beams with initial geometrical imperfection were studied. A suitable dynamic buckling criterion was defined. It was observed that viscous ...


Equivalent Relationship Of Function-Level Representation And Implementation Of Unified Indexing Of Fft Algorithms, Nee-Hua Cho Nov 1995

Equivalent Relationship Of Function-Level Representation And Implementation Of Unified Indexing Of Fft Algorithms, Nee-Hua Cho

Dissertations and Theses

With the advance of the VLSI technology, the FFT algorithm has been pushed further in solving the multidimensional array signal processing in real time. Many DSP chip users have tried to find ways to improve addressing huge data in multidimension systems with minimum cost and maximum performance. However, there is no efficient method to address data for 1-D to M-D FFTs. A methodology has been defined to conquer the addressing problem ofM-D FFT. It is well known that the twiddle factor matrix of Discrete Fourier Transform (DFT) can be recursively factored into basic butterfly stage matrices. The matrix can be ...


Malt Drying Model Verification For Efficiency Improvement, John David Kribs Nov 1995

Malt Drying Model Verification For Efficiency Improvement, John David Kribs

Dissertations and Theses

The aim of this work has been to minimize the thermal energy required to dry malt in deep beds while maintaining malt quality, and without increasing the drying time more than one hour. Malt drying usually takes place in deep bed (. 7-1 m) driers by forcing hot air through the bed. Measurements of inlet and outlet relative humidity, temperature, and airflow at a drier at Great Western Malting Company's Vancouver, Washington facility were made to find average moisture content versus time. The measurements were used to develop a wetted surface model of a malt bed. However, the model was ...


A Feasibility Study On The Automation Of Domestic Airline Passenger Customer Service Check-In Procedures For Far Part 121 Carriers, Don Michael Trevor Bennett Nov 1995

A Feasibility Study On The Automation Of Domestic Airline Passenger Customer Service Check-In Procedures For Far Part 121 Carriers, Don Michael Trevor Bennett

Theses - Daytona Beach

This study was conducted in an attempt to determine whether airlines can benefit from a fully automated customer service system which will be used by major, Part 121, operators for domestic travel purposes only. The proposed system will be designed to alleviate airport terminals check-in counter congestion and improve customer service personnel effectiveness and efficiency.

Domestic traffic is expected to increase by 50 percent by the year 2004. An Automatic Ticketing and Baggage (ATB) system will allow passengers to process all flight related transactions only once. A self checking-in system allows a passenger to obtain boarding passes and destination bag ...


Computer-Aided Process Design For Waste Minimization, Konstadinos Abeliotis Oct 1995

Computer-Aided Process Design For Waste Minimization, Konstadinos Abeliotis

Dissertations

Problems related to process design with environmental considerations have been studied in this dissertation. A new heuristic design methodology has been formulated with the objective of minimizing the adverse environmental impact of chemical processes.

This hierarchical methodology starts with the definition and analysis of a process flowsheet followed by quantification of the process environmental loads. The quantification of environmental loads is an essential aspect of this methodology, because it serves as the comparative measure for environmental performance.

If the calculated environmental loads do not satisfy the environmental constraints (e.g., regulatory limits), waste minimization is investigated in the following order ...


Removal Of Vocs From Air By Absorption And Stripping In Hollow Fiber Devices, Tarun K. Poddar Oct 1995

Removal Of Vocs From Air By Absorption And Stripping In Hollow Fiber Devices, Tarun K. Poddar

Dissertations

Large volumes of exhaust air streams contaminated with volatile organic compounds (VOCs) such as toluene, xylene, acetone etc. are discharged into the atmosphere by various industrial facilities. Common technologies for VOC emission abatement e.g., activated carbon adsorption, absorption in a liquid, incineration and catalytic oxidation, have many strengths as well as considerable limitations. In this study, a regenerative absorption-based removal of VOCs from N2 in an inert, nonvolatile, organic liquid flowing in compact hollow fiber devices has been developed. The process eliminates flooding, loading and entrainment encountered in conventional absorption devices.

Contaminated air/N2 stream was fed ...


Vibration As An Aid In Robotic Peg-In-Hole Assembly, Hsin-Te Liao Oct 1995

Vibration As An Aid In Robotic Peg-In-Hole Assembly, Hsin-Te Liao

Dissertations

This dissertation presents an analytical and experimental investigation of vibration assisted engagement for parts mating. A dynamic model of assembly is established by using Lagrange's equation for impact to derive impact equations for a robotic manipulator in peg-in-hole assembly. The model can be used to analyze part motion and contact force in the mating of parts by robots. The impact equations of a SCARA robot are derived using this model and utilized to investigate how robot configuration, insertion speed, chamfer angle, coefficient of restitution and other system parameters affect impulsive force and departure angle in the assembly of a ...


Particle Deposition On Surfaces In A Divergent Channal Flow, Ding Sun Oct 1995

Particle Deposition On Surfaces In A Divergent Channal Flow, Ding Sun

Dissertations

Particle trajectory and deposition of two phase gas-solid flows in a convergent or divergent two-dimensional channel are investigated numerically in a wide range of parameters. For the fluid phase, a two dimensional, incompressible laminar fluid flow is considered in the analysis. The particle phase is a diluted suspension. The effects of inertia, gravity, viscous force and electrostatic image force are included in the computational model.

Both convergent and divergent channel flow are solved by the finite element method based on the software FIDAP. The flow separations will appear in a divergent channel and their separation positions are obtained in the ...


Synthesis Of Boron Nitride/Vycor Composite Membrane Structures By An Optimized Lpcvd Process, Chenna Ravindranath Oct 1995

Synthesis Of Boron Nitride/Vycor Composite Membrane Structures By An Optimized Lpcvd Process, Chenna Ravindranath

Theses

Since the advent of the idea of ultrafiltration, microporous membranes have come through a long way in establishing a niche as an efficient technology for gas separation applications. More and more research is aimed at reducing pore size towards nanolevels, when separation factor is the criterion rather than the permeability. This work is focused at synthesizing and characterizing microporous inorganic membranes for gas separations by molecular sieving. BN was deposited on mesoporous vycor tubes using triethylamine borane complex (TEAB) and ammonia as precursors. Effect of temperature and deposition geometry on permeability of various gases has been studied. Very high selectivities ...


Congestion Management Systems Development And Implementation : Four Case Studies, Arlene Rose-Marie Willis Oct 1995

Congestion Management Systems Development And Implementation : Four Case Studies, Arlene Rose-Marie Willis

Theses

To address concerns of poor air quality, congested highways and the need to manage and plan for transportation within budgetary constraints, the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) mandated the development and implementation of a Congestion Management System (CMS). Primarily, a CMS will fuel transportation decision making with information on system performance and alternate strategies to alleviate congestion and enhance mobility. Efforts through ISTEA are expected to produce a more efficient American transportation system -- this thesis takes a look at the preparatory activities.

It is based on a federally funded project with metropolitan planning organizations (MPOs) in Albany ...


Low Pressure Chemical Vapor Deposition Of Tungsten As An Absorber For X-Ray Masks, Hongyu Chen Oct 1995

Low Pressure Chemical Vapor Deposition Of Tungsten As An Absorber For X-Ray Masks, Hongyu Chen

Theses

Tungsten film is one of promising materials for X-ray absorber in X-ray Lithography technology because of its high X-ray absorption and refractory properties. This study focus on CVD method to make tungsten film for X-ray absorber.

In this work, a cold wall, single wafer, Spectrum 211 CVD reactor was used for the deposition of tungsten from H, and WF6. The growth kinetics were determined as a function of temperature, pressure and flow ratio. The deposition rate of as deposited tungsten films was found to follow an Arrehnius behavior in the range of 300-500°C with an activation energy of 55 ...


Intermodal Commuter Network Planning, Maria P. Boile Oct 1995

Intermodal Commuter Network Planning, Maria P. Boile

Dissertations

An intermodal commuter network is an integration of passenger transportation systems, or modes, to a single comprehensive system that provides connections among the various modes, and improved travel choices to users. In the system examined in this dissertation, commuters access their final destination via auto, rail, and intermodal auto-to-rail modes. There are numerous highway paths by which a commuter can reach the final destination. Once on the highway, the commuter can switch to rail at stations along the rail route. The commuter may also choose to walk to the rail station closest to the trip's origin.

The main focus ...


A Theoretical Analysis Of Volatile Contaminant Removal By The Pneumatic Fracturing Process, Yuan Ding Oct 1995

A Theoretical Analysis Of Volatile Contaminant Removal By The Pneumatic Fracturing Process, Yuan Ding

Dissertations

A mathematical model that simulates the process of contaminant removal from a pneumatically induced fracture within a porous medium is presented. It includes: (1) model development; (2) parameter evaluation; (3) statistical sensitivity analysis; and (4) model validation.


The Effect Of Chlorine, Sulfur And Phosphorus Compounds On Deactivation Of Palladium Catalysts, Tai-Chiang Yu Oct 1995

The Effect Of Chlorine, Sulfur And Phosphorus Compounds On Deactivation Of Palladium Catalysts, Tai-Chiang Yu

Dissertations

The effects of HCl, H2S, tributyl phosphate (TBP), P2O5, and zinc dialkyldithophosphate (ZDP) as catalyst poisons for methane oxidation over palladium catalysts supported on γ-alumina were investigated in this study. The overall reaction rate of methane oxidation over palladium catalysts can be simplified into a pseudo first order reaction under excess oxidation conditions.

The deactivation of the catalyst poisoned by HCl is attributed to the loss of active sites due to volatilization of PdCl2. H2 treatment at 200 °C can reactivate the catalyst poisoned by HCl at temperatures of up to 300 °C ...


A Study Of Settlement In Landfills Due To Biodegradation, Michael Guasconi Oct 1995

A Study Of Settlement In Landfills Due To Biodegradation, Michael Guasconi

Theses

Finding new space for landfills is difficult due to land availability, stringent environmental regulations, and public sentiment. So other means of waste disposal, such as hauling it to a distant landfill, or incinerating it, will have to be resorted to. These methods may be unpopular with the public involved. By studying settlement due to biodegradation, ways to increase settlement can be found, allowing for additional waste disposal capacity in operating, and closed landfills.

Existing theoretical models are based on rheological concepts, not on biodegradation. So, they do not realistically model settlement. In this study, a model to determine the rate ...


Optimizing Rail-Truck Intermodal Drayage Operations, Wen Zhang Oct 1995

Optimizing Rail-Truck Intermodal Drayage Operations, Wen Zhang

Theses

This thesis presents a case study of the trucking (or drayage) portion of rail-truck intermodal freight transportation. The approach used was to examine in detail the current costs and potential for improvement at one New Jersey intermodal terminal. The analysis is conducted using a mathematical programming model to find an optimal scheduling plan for the drayage operation. To solve the model more efficiently, a modification is made to explore the special structure of the original problem which has a sparse constraint matrix. The model is solved first with an objective function that minimizes the total cost of the operation, and ...


Reverse Osmosis As A Pretreatment Of Ion Exchange Equipment At Pse & G'S Hudson Generation Station, Steven Leon Oct 1995

Reverse Osmosis As A Pretreatment Of Ion Exchange Equipment At Pse & G'S Hudson Generation Station, Steven Leon

Theses

Public Service Electric and Gas Company's Hudson Generating Station has historically had problems providing sufficient high quality water for its two once through, supercritical design boilers. The station requires over 60 million gallons annually to compensate for system losses.


Chute Flow Experiments, Yahong Zhang Oct 1995

Chute Flow Experiments, Yahong Zhang

Theses

The objective of this thesis is to study the behavior of granular materials flowing down an inclined chute using three diagnostic techniques under different chute inclination angles and chute floor conditions. The three methods are: (1) tracking the motion of single particle within the mass in a noninvasive manner using a transmitting sphere and antenna receiving system, (2) scale mass flow rate measurement, and (3) high speed camera system to obtain flow velocity measurements.

For these purposes, an experimental setup has been completed and a set experiments has been performed.