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Algiers, Algeria

The purpose of this study is to determine the period of preventive repairs for a gas turbines, to prevent the forced stops and to restore the initial technical state of components. Has this effect we use the renewal theory and the Markov process based on the theory of reliability depending on the results of observation and processing of statistical data of exploitation. Manage the operation of a system designed to achieve a given work is to guarantee the possibility of having the system in operation for a specified period before the preventive repair with high reliability. The quantity of spare parts for this repair, available at the level of the maintenance service, is also to reduce the time of the repairs of the machines. The planning of the period of maintenance work depends on the technical condition of the machines, which the variation in time is a function of the type and of the speed of wear. The maintenance of the machine plays an important role on its reliability i.e. on the state of the machine. To solve the problem of optimization of the frequency of preventive repairs it is necessary to take into account all the factors; deteriorating state (aging, wear, deformation) and the improving (control and testing; prevention and repair.) We suppose that after each maintenance repair, the machine is restored to its original state; t.e. after each repair the frequency between 2 preventive repairs will be again planned on the basis of the deterioration of the state of the machine. Source

Menouar B.,University of Boumerdes
2010 International Conference on Machine and Web Intelligence, ICMWI 2010 - Proceedings

This paper presents an insight on genetic algorithm (GA) encoding representations applied to graph partitioning problems. Redundancy and blindness, two important features that have a direct impact on the performance of the method, are theoretically investigated and some conclusions are drawn. © 2010 IEEE. Source

Abbas M.,University of Boumerdes | Trari M.,University of Science and Technology Houari Boumediene
Process Safety and Environmental Protection

The preparation of activated carbon from apricot stone (ASAC) activated with H3PO4 and its ability to remove the basic dye Congo red (CR) used in the textile industry in aqueous solution are reported in this study. The FTIR spectroscopy is used to get information on the interactions between the ASAC adsorbent and CR. A series of contact time experiments were undertaken in stirred batch to assess the effect of the system variables. The results showed that ASAC can be successfully used the wastewater treatment. A comparison of two models on the overall adsorption rate showed that the kinetic of adsorption was better described by the pseudo-second order model. The adsorption data of CR onto ASAC are determined and correlated with common isotherms equations. The small values of the Root Mean Square Error (RMSE) obtained for the Langmuir and Dubinin-Radushkevich models indicate the best fitting of the curves. The monolayer adsorption capacity of CR is found to be 32.85 mg g-1 at 25 °C and 23.42 mg g-1 at 65 °C at pH ∼ 13. The thermodynamic parameters indicate a spontaneous and endothermic nature of the adsorption process. The positive entropy (ΔS°) shows that the randomness increases at the solid-solution interface during the CR adsorption, indicating that some structural exchange occurs among the active sites of the adsorbent and CR molecules. © 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. Source

Berrazouane S.,University of Boumerdes | Mohammedi K.,University of Boumerdes
Energy Conversion and Management

This paper presents the development of an optimized fuzzy logic controller (FLC) for operating a standalone hybrid power system based on cuckoo search algorithm. The FLC inputs are batteries state of charge (SOC) and net power flow, FLC outputs are the power rate of batteries, photovoltaic and diesel generator. Data for weekly solar irradiation, ambient temperature and load profile are used to tune the proposed controller by using cuckoo search algorithm. The optimized FLC is able to minimize loss of power supply probability (LPSP), excess energy (EE) and levelized energy cost (LEC). Moreover, the results of CS optimization are better than of particle swarm optimization PSO for fuzzy system controller. © 2013 Elsevier Ltd. All rights reserved. Source

Abbas M.,University of Boumerdes | Kaddour S.,University of Science and Technology Houari Boumediene | Trari M.,University of Science and Technology Houari Boumediene
Journal of Industrial and Engineering Chemistry

The activated carbon from apricot stone with H3PO4 and its ability to remove Co2+ are reported. The FTIR spectroscopy brings insights on interactions between the functional groups of the carbon and Co2+. Adsorption studies are carried in batch mode by varying the initial Co2+ concentration and pH. A comparison of two kinetic models on the overall adsorption rate shows that the system is described by the pseudo-second-order kinetic model. The Freundlich model fits the data with a monolayer adsorption capacity of 111.11mg/g at pH 9. The enthalpy and free energy indicate an endothermic and not spontaneous process. © 2013 The Korean Society of Industrial and Engineering Chemistry. Source

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