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Aziz A.,Gonzaga University | Bouaziz M.N.,Dr. Yahia Fares University Center of Medea
Energy Conversion and Management | Year: 2011

Approximate but highly accurate solutions for the temperature distribution, fin efficiency, and optimum fin parameter for a constant area longitudinal fin with temperature dependent internal heat generation and thermal conductivity are derived analytically. The method of least squares recently used by the authors is applied to treat the two nonlinearities, one associated with the temperature dependent internal heat generation and the other due to temperature dependent thermal conductivity. The solution is built from the classical solution for a fin with uniform internal heat generation and constant thermal conductivity. The results are presented graphically and compared with the direct numerical solutions. The analytical solutions retain their accuracy (within 1% of the numerical solution) even when there is a 60% increase in thermal conductivity and internal heat generation at the base temperature from their corresponding values at the sink temperature. The present solution is simple (involves hyperbolic functions only) compared with the fairly complex approximate solutions based on the homotopy perturbation method, variational iteration method, and the double series regular perturbation method and offers high accuracy. The simple analytical expressions for the temperature distribution, the fin efficiency and the optimum fin parameter are convenient for use by engineers dealing with the design and analysis of heat generating fins operating with a large temperature difference between the base and the environment. © 2011 Elsevier Ltd. All rights reserved. Source


Chebbah M.,Dr. Yahia Fares University Center of Medea
Arabian Journal of Geosciences | Year: 2016

Depositional sequences and paleogeographic evolution of the Miocene deposits have been studied in the Zibane zone (Saharan Atlas, Algeria) located at the north of the African platform. During the Miocene, this region corresponded to a fault-bounded collapse area and filled by diversified deposits, showing important lateral facies and thicknesses variations. The studied deposits are divided into five depositional sequences separated by major unconformities. These depositional sequences are well developed in the whole basin and testify a paleogeographic differentiation from E–W, induced by a set of NW-SE-trending old faults inherited from the Atlasic orogeny. The organization and the development of those sequences make it possible to correlate them better to the basin scale, which is integrated in a model of restricted platform intersected by NW-SE faults where the tectonic-sedimentation duality is predominant. These new data point to a paleogeographic evolution different from the one usually admitted environment for this region during Miocene time and plead in favour of a reconsideration of the depositional environments of the post-Burdigalian formations in the Zibane zone of the Algerian Atlasic domain. © 2016, Saudi Society for Geosciences. Source


Bouaziz M.N.,Dr. Yahia Fares University Center of Medea | Aziz A.,Gonzaga University
Energy Conversion and Management | Year: 2010

A novel concept of double optimal linearization is introduced and used to obtain a simple and accurate solution for the temperature distribution in a straight rectangular convective-radiative fin with temperature dependent thermal conductivity. The solution is built from the classical solution for a pure convection fin of constant thermal conductivity which appears in terms of hyperbolic functions. When compared with the direct numerical solution, the double optimally linearized solution is found to be accurate within 4% for a range of radiation-conduction and thermal conductivity parameters that are likely to be encountered in practice. The present solution is simple and offers superior accuracy compared with the fairly complex approximate solutions based on the homotopy perturbation method, variational iteration method, and the double series regular perturbation method. The fin efficiency expression resembles the classical result for the constant thermal conductivity convecting fin. The present results are easily usable by the practicing engineers in their thermal design and analysis work involving fins. © 2010 Elsevier Ltd. All rights reserved. Source


Yssaad B.,Dr. Yahia Fares University Center of Medea | Khiat M.,Polytechnic School of Algiers | Chaker A.,Polytechnic School of Algiers
International Journal of Electrical Power and Energy Systems | Year: 2014

Today's electricity distribution systems operate in a liberalized market. These systems should therefore be able to provide electricity to customers with a high degree of reliability and be cost-effective for suppliers. RCM (Reliability Centred Maintenance) was invented by the aircraft industry in the 1960s, to organize the increasing need for maintenance for reducing costs without reducing b safety. Today RCM-methods invented by ALADON [1] are seen as very complex and are not fully accepted by the Algerian power industry. The extensive need of human and capital resources in the introduction phase is also a negative factor that could be one of the reasons of why RCM methods are not used in our branch. This article provides a discussion of the two primary objectives of RCM: to ensure safety through preventive maintenance actions, and, when safety is not a concern, preserve functionality in the most economical manner. For the power distribution systems facilities, the mission should be considered at the same level as safety. © 2013 Elsevier Ltd. All rights reserved. Source


Bouzidi A.,Nuclear Research Center of Birine | Souahi F.,Polytechnic School of Algiers | Hanini S.,Dr. Yahia Fares University Center of Medea
Journal of Hazardous Materials | Year: 2010

In the present study, the sorption behavior of cesium was investigated in Ain Oussera soil around the Es-Salam reactor facility. This study was conducted using batch method under different physicochemical conditions including contact time, ionic strength, pH, solid/liquid ratio and temperature. The results showed that sorption followed pseudo-second-order kinetics with a good regression coefficients (R2=0.999). The activation energies were 11.26 and 15.21kJmol-1 which correspond to ion-exchange-type sorption mechanism. The adsorption was favored at low temperature and it was exothermic (ΔH0<0, with average value of -1.97kJmol-1) and spontaneous (ΔG0<0, with average value of -11.97kJmol-1 at 23°C and -13.2kJmol-1 at 60°C). The presence of competing cations such as K+ and Ca2+ ions in groundwater can significantly reduce the Cs adsorption onto soil. Desorption reaction was also investigated using three reagents with different ionic strengths (deionized water, groundwater and 0.1M KCl solution). The results showed that Cs ions were preferentially distributed onto high affinity sorption sites. © 2010 Elsevier B.V. Source

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