Power switches require snubbing networks for driving single – phase industrial heaters. Designing these networks, for controlling the maximum allowable rate of rise of anode current (di/dt) and excessive anode – cathode voltage rise (dv/dt) of power switching devices as thyristors and Triacs, is usually achieved using conventional methods like Time Constant Method (TCM), resonance Method (RM), and Runge-Kutta Method (RKM). In this paper an alternative design methodology using Fuzzy Logic Method (FLM) is proposed for designing the snubber network to control the voltage and current changes. Results of FLM, with fewer rules requirements, show the close similarity with those of conventional design methods in such a network of a Triac driving 1.2 kW heater of an industrial plastic extruder machine. The similarity, between Fuzzy Logic results and conventional techniques results, is confirming the applicability of the fuzzy logic in designing these snubbing networks.
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In this paper, turbidimetric and reversed-phase ultra-fast liquid chromatography (UFLC) methods were described for the quantitative determination of ephedrine hydrochloride in pharmaceutical injections form. The first method is based on measuring the turbidimetric values for the formed yellowish white precipitate in suspension status in order to determine the ephedrine hydrochloride concentration. The suspended substance is formed as a result of the reaction of ephedrine hydrochloride with phosphomolybdic acid which was used as a reagent. The physical and chemical characteristics of the complex were investigated. The calibration graphs of ephedrine were established by turbidity method. While the second method (UFLC) was conducted using the
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The main objective of this study is to introduce a systematic design procedure for short-span segmental beams following a sophisticated ACI 440.2R-17 design procedure. The general aspects of innovative short-span segmental beams are easy to fabricate, economical and rapidly placed in pre-specified positions. Short-span segmental beams fabricated from individual precast plain-concrete blocks and CFRP plates. Recently, experimental tests performed on short-span segmental beams, by the authors, investigated CFRP plate-bonding, CFRP plate cross-sectional area, the thickness of plate-bonding epoxy resin, surface-to-surface condition of concrete blocks, as well as, interface condition of the bonding surface. The experimental program comprises tes
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In this paper an atmometer apparatus were used in the greenhouses for estimating reference evapotranspiration values. Experimental work was conducted in the agriculture research center in the College of Agriculture-University of Baghdad west of the city of Baghdad. One atmometer was used in eggplant greenhouse and in cucumber greenhouse through the winter growing season 2013-2014. FAO Penman-Monteith equation was applied outside the greenhouse and used only 65% from the value of ETo in the greenhouses for estimating the reference evapotranspiration in the greenhouse. Moreover, Penman-Monteith equation was applied in greenhouses for the evaluating the performance of the atmometer. The results show that the erro
... Show MoreA novel design and implementation of a cognitive methodology for the on-line auto-tuning robust PID controller in a real heating system is presented in this paper. The aim of the proposed work is to construct a cognitive control methodology that gives optimal control signal to the heating system, which achieve the following objectives: fast and precise search efficiency in finding the on- line optimal PID controller parameters in order to find the optimal output temperature response for the heating system. The cognitive methodology (CM) consists of three engines: breeding engine based Routh-Hurwitz criterion stability, search engine based particle
swarm optimization (PSO) and aggregation knowledge engine based cultural algorithm (CA)
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This article aims to establish and evaluate standards for critical equipment and materials in highway projects in Iraq. Delphi technique has been used to analyze, explore, and discover the main criteria and sub-criteria that affect equipment and materials in highway construction projects in Iraq. To determine the correct response to the criteria presented in this study, a program (IBM, SPSS/V25) was used to assess the main criteria and sub-criteria using the mean score (MS) and standard deviation (SD) technique, as well as to check reliability using Cronbach's alpha factor (α). The experts' qualifications and the extent to which the person is ready to commit are both important factors in panel selection. The design of a
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The increasing Global Competitive and the continuous improvement in information technology has led the way to the development of the modern systems and using modern techniques. One of these techniques is benchmarking style and Total Quality Management all of them are used to improve the production process and target rid from the losts on the other side.
The Benchmarking style has become a very important for all the industrial systems and the serving systems as well. And an instrument to improve their performance specially those which are suffering from the highness of the costs or waste in time on the other side.
This study aims to depend on virtual Benchmarking style in the eval
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Background/objectives: To study the motion equation under all perturbations effect for Low Earth Orbit (LEO) satellite. Predicting a satellite’s orbit is an important part of mission exploration. Methodology: Using 4th order Runge–Kutta’s method this equation was integrated numerically. In this study, the accurate perturbed value of orbital elements was calculated by using sub-steps number m during one revolution, also different step numbers nnn during 400 revolutions. The predication algorithm was applied and orbital elements changing were analyzed. The satellite in LEO influences by drag more than other perturbations regardless nnn through semi-major axis and eccentricity reducing. Findings and novelty/improvement: The results demo
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