Browsing Engineering Journal of Qatar University - [From 1988 TO 2005] by Title
Now showing items 171-190 of 221
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Reduced Snubber Circuit Elements For Pwm Voltage Source Inverter
( Qatar University , 2002 , Article)This paper presents the description and simulation of a new proposed arrangement of RLD/RCD snubber circuit used with pulse width modulated voltage source inverter. The new arrangement allows minimizing the number of active ... -
Refractivity Statistics For Two Countries In The Middle East
( Qatar University , 1989 , Article)This paper presents and compares the results of refractive index studies for Mersa Matrouh, Egypt, and Doha, Qatar. Statistics for surface refractivity and refractivity gradients at different heights from the surface are ... -
Refrigerants Beyond 1995 - An Overview
( Qatar University , 1994 , Article)The count down has started. Less than 400 days, that is all the time left till the complete phase-out of CFC production. No more refrigerants R-l 1, R-12 or R-500 will be produced worldwide. With our extreme dependence - ... -
Repetitive Control Based Pwm Inverter Dead-Time Compensation For Ac Servo Drive
( Qatar University , 2002 , Article)AC servomotor speed or current controller based on PI control and/or optimal control, can not eliminate the cyclical fluctuations of speed or current when subject to periodic disturbances. However, repetitive control ... -
A Review of Fatigue Testing Machines
( Qatar University , 1990 , Article)In this paper fatigue testing facilities are first classified in accordance with a number of features which include purpose, type of loading, method of load application and transmittal as well as control system. Owing to ... -
A Review Of Petroleum Engineering Aspects Of Qatar's Oil And Gas
( Qatar University , 1998 , Article)This paper reviews, from a petroleum engineering point of view, the 60 years of discovery and development of tlie oil and gas resources within the boundaries of the State of Qatar. Up to 1990 there were four major hydrocarbon ... -
Secondary vs. Tertiary oil recovery from a two-dimensional porous media by microemulsion flooding
( Qatar University , 1989 , Article)The objective of this research was to study the application of microemulsion flooding in a visual, two-dimensional sandpack for the purpose of investigating the efficiency of oil displacement during secondary and tertiary ... -
Selection Of Optimized Fuzzy Rules For Process Control Systems: Using Genetic Algorithms
( Qatar University , 1996 , Article)In this paper modeling, selection and optimization of fuzzy rules for multivariable feedback process control and decision making systems are developed and discussed. A general model for multivariable fuzzy rules is derived ... -
A Self-Organizing Multisensor Fusion Classification Algorithm
( Qatar University , 1996 , Article)A self-organizing multisensor fusion algorithm to classify the inputs (data or images) into classes (targets, backgrounds) is presented. The algorithm forms clusters and is trained without supervision. The clustering is ... -
Shear Behavior Of Reinforced High-Strength Concrete Beams Without Shear Reinforcement
( Qatar University , 1994 , Article)Eighteen rectangular singly reinforced high-strength concrete beams without web reinforcement were tested in combined shear and flexure. The main variables were the longitudinal steel reinforcement ratio and the shear-span ... -
Signal Identification Using A Microprocessor Based Phase Locked Loop System
( Qatar University , 1989 , Article)A scheme for waveform comparison and the measurement of periodic signal parameters through processing, controlling and measuring programs is realised. A microcomputer is used with a phase locked loop voltage controlled ... -
The Significance Of Permeability And Wettability Contrasts On Near Wellbore Flow Patterns Creating Formation Damage Effects
( Qatar University , 1999 , Article)The majority of hydrocarbon reservoirs are heterogeneous and any geological model that is unable to represent these heterogeneities will not capture the correct displacement physics. In particular, difficulties are encountered ... -
Simplified Method For Plate Deflection Calculation
( Qatar University , 1997 , Article)This paper presents a simplified method for the calculation of thin-plate deflections. The method, which deals with uniformly loaded plates, uses the stiffness method to obtain plate deflection equations for specified ... -
Simulation of Cross-Current Extraction Processes
( Qatar University , 1988 , Article)Extraction processes dealing with partially miscible solvents are usually calculated by graphical methods to estimate the number of stages required, flow rates and compositions of the streams. Such procedures may be lengthy. ... -
Simulation Of Three-Phase Distillation Column Using Bubble Point And Φ-Φ Approach
( Qatar University , 1995 , Article)Most of organic compounds are partially miscible in water and due to their solubility criteria split into two liquid phases. So design of equipments that separate two liquid phase systems differ from one liquid phase system ... -
Software For On-Line Monitoring Of E10-B Telephone Exchange
( Qatar University , 1991 , Article)The proposed software aims at enhancing the monitoring of the E10-B telephone exchange. It combines functions normally performed by two dedicated hardware devices and facilitates access to detailed maintenance information ... -
Soil Classification Decision Support System Using An Expert System Approach
( Qatar University , 1998 , Article)Soil classification systems are necessary for the identification of soil properties. Expert systems can be a very powerful tool in identifying soils quickly and accurately. In this paper, an interactive and user-friendly ... -
A Solar Pond For Air Conditioning A Small Family House In Qatar
( Qatar University , 1992 , Article)The concept of using a solar pond to provide air conditioning for a typical small family Qatari house is developed. Though the idea seems appealing for a number of reasons, the design study shows it to he technically ... -
Solar Water Pumping — An Analytical Overview
( Qatar University , 1988 , Article)Two basic thermodynamic conversion techniques of solar water pumping are recognized. In the first technique, a high internal energy fluid heated in a solar collector is used to power a conventional heat engine which drives ... -
Solidification Of Steel Billets In Continuous Casting
( Qatar University , 1991 , Article)For practical operation, it is necessary to know how the solidification of liquid steel progresses i.e. when and where a strand has completely solidified. Decisions on, the casting speed, the spray water flow rates and ...