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Articles 181891 - 181920 of 197169

Full-Text Articles in Engineering

Wastewater Treatment : Phenol Extraction By Liquid Membrane, Jan-Ming Hou May 1988

Wastewater Treatment : Phenol Extraction By Liquid Membrane, Jan-Ming Hou

Theses

Two models for the extraction of phenol by means of liquid surfactant membranes is presented in which external mass transfer around w/o emulsion drop, phase and chemical equilibria are taken into account.

The nonlinear coupled P.D.E.'s is solved under assumptions to get a close-formed analytical approximate solution. The experimental results on the batch extraction of phenol are found to be satisfactory simulated by one of the proposed models provided that phenol concentration is higher than 0.01N. The model requires no adjustable parameter thus it can predict the extraction behavior without doing experiments.


Investigation Of Different Cmos Dram Sense Amplifier Configurations In Vlsi, Bihju Chiu May 1988

Investigation Of Different Cmos Dram Sense Amplifier Configurations In Vlsi, Bihju Chiu

Theses

Sense amplifiers are particularly difficult circuits to design. In this work, only CMOS sense amplifiers are considered. There are typically two configurations of CMOS sense amplifiers: the cross-connected flip flop configuration and the current-mirror configuration. They are widely used nowadays with various modifications. These improved configurations are simulated and optimized with SPICE package, and their relative performances are also compared in this thesis.


Synergistic Fillers In Polymer Concrete : New Composites, Syed Hassan Javed May 1988

Synergistic Fillers In Polymer Concrete : New Composites, Syed Hassan Javed

Theses

The objective of this study was to examine the effects of synergistic fillers on underwater construction, burning and mechanical properties of polymer portland cement concrete(PPCC).

Fine grains of hydrous calcium sulfate, Trihydrated alumina, Calcium carbonate and fibrous unhydrous calcium sulfate were examined in PPCC. It has been observed that these synergistic filler improves the mechanical property (stress) and reduce the average time of burning of PPCC. With fixed quantity of polymer, the deterioration of PPCC in water increases by replacing the sand with above stated fillers.


Rf Characterization Of A Directly Modulated Ingaasp Buried Heterostructure Laser Diode, Charlotte Alvarez May 1988

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

Theses

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

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


Estimation Of Modified Proctor Densities Based On Visual Identification, Ramesh Damodaram May 1988

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

Theses

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

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


Implementation Of The Voice Processing System, Yang-Young Dan May 1988

Implementation Of The Voice Processing System, Yang-Young Dan

Theses

The Voice Processing System is implemented by using XILINX Advanced Computer Aided Design Technology. It is also used as an interface to the 8052 AH-BASIC single hoard computer system.

The Voice Processing System ( VPS ) comprises three major parts:

1. Voice Detection Circuit

2. System Clock Generation & Synchronization

3. Signal Processing and Storing Circuit

The analog voice sip!gnals are the inputs to the first part of VPS. The digitalized voice is the output of this system.

In order to get precise output, the first part plays the roles of noise cancellation, zero crossing processing, and recognition.

For the …


Two Domain Heat Transfer Studies Using A Coupled Finite-Difference And Boundary Element Programs, Serap Dikmenli May 1988

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

Theses

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

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


Reliability Of Packaging In Microcircuits, Zia Iqbal May 1988

Reliability Of Packaging In Microcircuits, Zia Iqbal

Theses

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

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

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


Determination Of Project Duration For Resource Constrained Projects Without Using Resource Scheduling Procedure, Rabindra Nath Karmakar May 1988

Determination Of Project Duration For Resource Constrained Projects Without Using Resource Scheduling Procedure, Rabindra Nath Karmakar

Theses

The problem addressed in this thesis is that of determining the practicability of equating measures of network and resource characteristics to the early finish date of a project which is constrained by resources. The output of standard critical path calculations along with information on resource profiles that are easy to calculate can be of use in estimating resource constrained project duration.

Twenty two different equations ( developed by Hall) were used to find the estimated project finish dates. These results were compared to the schedule resulting from the application of the heuristic rule of minimum activity float. It is shown …


Fetal Phonocardiography, Jeng-Kwan Lin May 1988

Fetal Phonocardiography, Jeng-Kwan Lin

Theses

A reliable non-invasive tracking of the fetal heart rate from the maternal abdominal surface could be of significant diagnostic importance in the monitoring of pregnancies, not only for fetal heart rate assessment, but also for the observation of congenital cardiac malformations and transient difficulties during labor. Further, the fetal heart rate recording may be used to assess fetal heart rate variability in the antepartum period of gestation when it is not possible to obtain a fetal scalp lead electrocardiogram.

There are several methods being used to detect the fetal heart rate. Phonocardiography, abdominal electrocardiography and ultrasound cardiography are the three …


Independent Equations Method For Power System State-Estimation, Shun-Gee Lin May 1988

Independent Equations Method For Power System State-Estimation, Shun-Gee Lin

Theses

The problem of power system state estimation (PSSE) is to convert the available. redundant and noise contaminated measurements, and other information into a best estimate of the state of the system.

Methods to solve the PSSE, including the sub-problems of bad data presence detection, identification and reconstruction, are reviewed. The Independent Equations Method (IEM) was selected for in-depth study and analysis.

The tree method for bad data identification is tested and failed due to the suspected ill-conditioning of the sensitivity matrix. For bad-data reconstruction, the IEM fails as described. Modifications that saves computing time and ensures reconstruction success are presented …


Interface To 8052ah-Basic Microcontroller For A Multichannel Priority Interrupt System, Chen-Tung Mo May 1988

Interface To 8052ah-Basic Microcontroller For A Multichannel Priority Interrupt System, Chen-Tung Mo

Theses

This thesis presents the design and development of a system with the capability to detect up to forty channels of signals generated from different analog sources and to process them under the control of a microcomputer.

The present work offers the design and implementation of a hardware interface unit in a multichannel real-time data acquisition system as well as the application software program to operate it. This kind of system can be widely used in process control, musical instrument interfacing, and machine automation.

This interface unit follows the general instrumentation architecture in both signal processing and logic control. The software …


High Frequency Gaussian Beams Solution Of A Plane Wave Coupling Into Cylindrical Cavity, Christine Issa Mourad May 1988

High Frequency Gaussian Beams Solution Of A Plane Wave Coupling Into Cylindrical Cavity, Christine Issa Mourad

Theses

Propagation of high frequency fields as a superposition of Gaussian beams instead of geometrical ray fields has potential advantages in complicated environments because the beams do not fail in ray optic transition regions. While the Gaussian beam method can be made rigorous through self consistent stacking of displaced and tilted beams on a Gabor phase space lattice, with retention of full beam spectra, computation is facilitated when the propagation domain is covered with paraxially approximated nontilted beams. The spectral deficiencies introduced by this simplified propagation model depend on the propagation environment. They are examined here for a plane wave coupling …


Image Enhancement And Edge Detection Using Fuzzy Algorithm, Samir Patel May 1988

Image Enhancement And Edge Detection Using Fuzzy Algorithm, Samir Patel

Theses

A method of image enhancement and edge detection by computer using the fuzzy set is illustrated. The algorithm involves extraction of fuzzy properties corresponding to pixels and then succesive application of fuzzy operator 'contrast intensification' along with smoothing in the fuzzy property plane before detecting its edges. The property plane is extracted from the spatial domain using S, π, and (1- π) functions and the fuzzifiers. Edge detection is achieved using KIRSH operator. A computer routine is developed and the effectiveness of the algorithm with different value of the system parameter is demonstrated on different images. The digital computer HP …


Study Of Dynamic Cmos Families And Development Of Certain Guidelines For Logic Synthesis, Vinay Santurkar May 1988

Study Of Dynamic Cmos Families And Development Of Certain Guidelines For Logic Synthesis, Vinay Santurkar

Theses

This work studies in detail two dynamic logic families, namely Zipper and Nora. It compares their performance using SPICE, a popular circuit simulator. Results show that a novel clocking scheme and a different latch circuit for the Nora pipelined structure can push its maximum clock rate of CMOS Dynamic circuits higher. It also ascertains whether the increased complexity of NORA is justified compared to the simpler Zipper circuit. It is shown that for very long logic chains, Nora works faster than Zipper. The work also presents some guidelines for synthesis of logic functions using CMOS Dynamic Cells. It shows that …


Integration Of Cad/Cam System Into A Waterjet Cutting Cell, Sanjay C. Shah May 1988

Integration Of Cad/Cam System Into A Waterjet Cutting Cell, Sanjay C. Shah

Theses

The work is intended to bridge the gap between CAD and CAM fora waterjet cutting cell. The output of CAD is used by CAM directly through the software interface developed. To achieve this, a postprocessor is designed for a two-dimensional system for the series 8200 Allen Bradley's 5-axes Robot Controller. Calma's DDM & DIMENSION III interactive graphics system implemented on VAX was used for the part design. The postprocessor is a computer program, written in the structured FORTRAN, that is unique for a given machine-tool/controller combination. The conversion of the coding and recording format of the APT file to the …


The Design, Manufacture And Mechanical Analysis Of An L4-5 Spinal Disc Prosthesis, Bohdan A. Siryi May 1988

The Design, Manufacture And Mechanical Analysis Of An L4-5 Spinal Disc Prosthesis, Bohdan A. Siryi

Theses

The purpose of this research was to develop an intervertebral disc prosthesis which can provide the biomechanical properties of the natural disc. The prosthesis will be used to replace the symptomatic degenerated disc and thereby limit backpain and subsequent spinal disease.

Four cadaveric L4-5 motion segments were mechanically tested under axial compression and combined compression/torsion, generating compressive moduli and torsional stiffness values. Following, prosthetic discs were fabricated and mechanically tested, with the fabrication technique directed towards the optimization of mechanical properties in compression, torsion and bending.

Thirty silicon rubber and forty five polyurethane disc prostheses were fabricated. Silicon rubber, dacron …


Analysis And Simulation Of Chirp Radar System, Tina Tsung Tsai May 1988

Analysis And Simulation Of Chirp Radar System, Tina Tsung Tsai

Theses

This paper consists of a technique to design a Chirp radar system and proposes a solution to optimize the design of the linear time delay network required in such systems. A Chirp radar system has a wide bandwidth for high range resolution, and long pulse duration for high velocity resolution and high transmitted energy. The technique of a pulse compression system offers a means of increasing the average power available to illuminate radar targets without any loss of the resolution at the receiver needed for the tactical requirements of the system. This is accomplished by transmitting a wide pulse in …


Cmos Sram Design For Initializing Programmable Logic Devices, Ravi K. Vaidyanathan May 1988

Cmos Sram Design For Initializing Programmable Logic Devices, Ravi K. Vaidyanathan

Theses

This thesis presents the design of CMOS Static Random Access Memory (SRAM) which is imbedded within a high performance Programmable Logic Device (PLD). The SRAM and its control circuitry are used to initialize (or personalize) the NJIT PLD chip. The design is defined in 3-levels of functional hierarchy consistent with the physical and electronic design automation utilized for this design. The imbedded SRAM supports the PLD application circuit which includes 8 small Array and one large Control Programmable Logic Arrays.

The SRAM is structured as 64 X 138 bit array with serial read and write inputs. It is designed emphasizing …


Automatic Generation Of Robot Paths For Waterjet Cutting From Autocad Drawings, Samir Vij May 1988

Automatic Generation Of Robot Paths For Waterjet Cutting From Autocad Drawings, Samir Vij

Theses

The automatic generation of robot paths for a commercial water-jet cutting system by establishing a link with a commercial CAD system, in an attempt to achieve paper-less manufacturing and to minimize human interface is the objective of this thesis.

Water-jet cutting is an emerging technology with unlimited potential for a wide variety of manufacturing applications. Water-jet cutting systems integrated with robotic work cells allow the user to cut a variety of parts through part programs generated for robot controllers. The system employed is an Ingersoll-Rand water-jet cutting system, the movement of which is controlled by an Allen-Bradley 8200R programmable robot …


Research, Development, And Evaluation Of A Solid State Transformer, Robert Michael Joseph Wozniak May 1988

Research, Development, And Evaluation Of A Solid State Transformer, Robert Michael Joseph Wozniak

Theses

The analysis and design of a solid state step down transformer is presented as part of a research study which reviews novel approaches to the development of high frequency power magnetic apparatuses and applies available theory to produce a solid state counter part. The resulting circuit exhibits the potential for efficiency as high as 85%, low output ripple, regulation that is comparable with other modes of power conversion and the ability to provide localized on-board power.


Comparative Energy Analysis Of An Office Building Using A Microcomputeromparative Energy Analysis Of An Office Building Using A Microcomputer, Dale Krasnoff Bromberg May 1988

Comparative Energy Analysis Of An Office Building Using A Microcomputeromparative Energy Analysis Of An Office Building Using A Microcomputer, Dale Krasnoff Bromberg

Theses

An energy analysis was performed on an office building using two different software packages - ASEAM and Trakload. The structure studied was the P.S.E. & G. headquarters in Newark, N.J.. The results of various parametric runs were compared. Then results from one of the programs were compared with results of a study carried out by Tishman Research Corporation and Jaros, Baum & Bolles, consulting engineers.

Although the two software products had variations in input requirements, overall the results of the two programs were similar. The overall deviation for total energy consumption between the two programs was between 3% and 15%. …


Study Of The Structure And Capacity Of Construction Industry In Pakistan, Tayyab A. Ansari May 1988

Study Of The Structure And Capacity Of Construction Industry In Pakistan, Tayyab A. Ansari

Theses

The construction industry is the second largest sector in Pakistan's economy after agriculture. It is a fragmented industry which includes very small and very large contracting groups. It includes professional groups such as architects, engineers, management personnel etc. Major part of this industry is dominated by material's suppliers, vendors etc.

In the light of the developments which have taken place particularly over the last ten years, the study has covered the capacity of the construction industry in terms of estimated output, availability of manpower, demand and production of building materials , financial problems, credit, quality of work, the role of …


Agitation Requirements For Complete Dispersion Of Emulsions, Dun-Huang Tsai May 1988

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

Theses

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


Bead Design For Biodegradation Of 2-Chlorophenol Using Microorganisms Entrapped In Alginate Gel, Fayaz Lakhwala May 1988

Bead Design For Biodegradation Of 2-Chlorophenol Using Microorganisms Entrapped In Alginate Gel, Fayaz Lakhwala

Theses

The performance of immobilized cell reactors varies with a number of parameters, one of which is proper bead design. A mixed microbial population from a waste water treatment plant was immobilized in calcium alginate gel. The viability of these organisms was studied in a microassay reactor by varying parameters such as concentration of calcium chloride, concentration of sodium alginate, temperature of operation, biomass concentration within the beads and concentration of a model compound (2-chlorophenol). The effect of storage on viability over a period of three months was also investigated. It was found possible to have access to active biomass by …


Design Of A Fiber Optic Oxygen Sensor Based On Immobilized Hemoglobin, Mendu Govind Raj May 1988

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

Theses

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


A 100-Khz - 22 Ghz Instrumentation Photoreceiver, Dennis J. Derickson, C. M. Miller, R. L. Van Tuyl May 1988

A 100-Khz - 22 Ghz Instrumentation Photoreceiver, Dennis J. Derickson, C. M. Miller, R. L. Van Tuyl

Electrical Engineering

A photoreceiver consisting of a high-speed p-i-n photodetector and a 100-kHz to 22-GHz distributed amplifier is described. Photoreceiver calibration is accomplished by optical heterodyne techniques. The photoreceiver is used with a microwave spectrum analyzer to produce a fully amplitude-calibrated 22-GHz-bandwidth lightwave signal analyzer system for displaying intensity-modulated light with -65-dB (optical) sensitivity at 1300-nm and 1550-nm wavelengths.


Implementing Ray Tracing Algorithm In Parallel Environment, Tjah Jadi May 1988

Implementing Ray Tracing Algorithm In Parallel Environment, Tjah Jadi

Dissertations and Theses

Ray tracing is a very popular rendering algorithm in the field of computer graphics because it can generate highly-realistic images from three-dimensional models. Unfortunately, the computational cost is very expensive. To speed up the rendering process we present both static and dynamic scheduling (balancing) strategies for a multiprocessor system. Hence, the load balancing among the processors is the most important problem in parallel processing. The implementation of the algorithm is based on a modified octree structure.


A Field Perspective On Groundwater Contamination, John A. Cherry May 1988

A Field Perspective On Groundwater Contamination, John A. Cherry

Maine Collection

A Field Perspective on Groundwater Contamination

Geological Society of Maine Distinguished Lecturer John Cherry, University of Waterloo, Ontario, sponsored by the Department of Geosciences, University of Southern Maine, 19th May 1988.

Contents: Lecture 1 : Contaminant Migration Processes Illustrated by Field Experiments / Lecture 2 : Behavior of Dense Non-Aqueous Phase Liquids, Illustrated by Lab Experiments and Conceptual Examples / Lecture 3 : Field Case Histories on Groundwater Contamination / Lecture 4 : Hydrogeological Concepts and Criteria for Waste Disposal / Waterloo Center for Groundwater Research Publications List


Dc-Excited Cw Co₂ Metal Waveguide Laser, Fahad Saleh Al-Mashaabi May 1988

Dc-Excited Cw Co₂ Metal Waveguide Laser, Fahad Saleh Al-Mashaabi

Dissertations and Theses

A novel design for a DC excited cw CO2 metal waveguide laser has been developed in which a slotted hollow-cathode in a transverse discharge also doubles as a metal waveguide. This design has been implemented in a compact design that produces up to 1 watt of cw, 10.6 μm radiation. The discharge characteristics, laser gain and laser output has been studied as functions of various discharge parameters. The advantages of the new transverse discharge of the slotted hollow cathode geometry include low voltage, positive impedence and high optical gain. Overall efficiency is comparable with those of conventional longitudinal CO …