Gomri R.,University of Mentouri Constantine
Energy Conversion and Management | Year: 2010
Owing to the serious environmental problems and the price of the traditional energy resources the use of industrial waste heat or the renewable energy, especially the solar energy, as the driving force for vapour absorption cooling systems is continuously increasing. A particular attention was given to single effect cycle. The main objective of higher effect cycle is to increase system performance when high temperature heat source is available. The purpose of the present study was to investigate the potential for the application of single effect double effect and triple effect absorption cooling cycles for production chilled water. For the three systems identical cold output of 300 kW is used. Simulation results were used to study the influence of the various operating parameters on the performance coefficient, exergetic efficiency and the ratio of mass flow rate of refrigerant generated to the heat supplied of the three systems. It is concluded that the COP of double effect system is approximately twice the COP of single effect system and that the COP of triple effect system is slightly less than thrice the COP of single effect system. The exergetic efficiency of double effect system and triple effect system increase slightly compared to the exergetic efficiency of single effect system. It is found that for each condenser and evaporator temperature, there is an optimum generator temperature. At this point the COP and exergetic efficiency of the systems become maximum. Triple effect system generates more vapour refrigerant per unit heat supplied as compared with single effect and double effect systems. © 2010 Elsevier Ltd. All rights reserved.
Bourbia F.,University of Mentouri Constantine |
Boucheriba F.,University of Mentouri Constantine
Renewable Energy | Year: 2010
Urban Planning has an immense impact on local microclimate which in turn affects the comfort and space quality within a city. The urban open spaces play an important role in creating the urban climate. The urban streets vary in geometry as defined by height/width ratio, sky view factor (SVF) and the orientation that is defined by its long axis. This directly influences the absorption and emission of incoming solar and outgoing long wave radiation which has a significant impact on the temperature variations within the street as well as the surrounding environment (Urban Heat Island). The objective of this research is to evaluate and to compare how the microclimate variation of urban street canyon can affect the built environment. Therefore the main aim of this paper is to discuss and assess the impact of the geometry on the street climate, in down town of Constantine-Algeria (semi arid climate). In order to achieve this goal, a series of site measurements, are utilised. The preliminary results strongly indicate an air temperature difference of about 3-6 °C between the urban street and its surrounding rural environment. © 2009 Elsevier Ltd. All rights reserved.
Boukhalfa C.,University of Mentouri Constantine
Desalination | Year: 2010
Sulfate removal from aqueous solutions by hydrous iron oxide freshly prepared in the presence of some heavy metals cations and some anions has been investigated in batch systems by varying the pH and concentrations of various ions. Infrared spectroscopic analyses have been performed to characterize the effect of these ions on the mechanism of sulfate interaction with the surface of the hydrous oxide. The results of macroscopic studies show that in the binary systems, copper and zinc ions inhibit the sulfate removal at pH higher than 5.5. In the presence of oxalate and phosphate ions, significant competitive effects are observed contrary to acetate ions. The IR spectra of the solids obtained show that among the studied ions, only phosphate ions have an effect on the sulfate interaction with the surface of the oxide. In their presence, the formation of outer sphere complex is more probable. © 2009 Elsevier B.V. All rights reserved.
Bouchaboub M.,University of Mentouri Constantine |
Samai M.L.,University of Mentouri Constantine
Engineering Structures | Year: 2013
A numerical technique for the analysis of high-strength reinforced concrete slender columns subjected to end loadings is presented. The finite difference method is applied to calculate the load corresponding to a specified deflection, considering both material and geometric nonlinearities. In this way, the complete load-deflection curve was computed for X columns that were also tested experimentally. The analysis procedure is applicable for columns with hinged extremities, although only isolated columns are evaluated herein. © 2012 Elsevier Ltd.
Bellel N.,University of Mentouri Constantine
Energy Procedia | Year: 2011
The main purpose of this work is the study of types of cylindrical canister with a spherical hub and our have two types of receptor, the first cylindrical closed and the second coil is a cylindrical Inside a receiver, we are particularly attached to the determination of operating characteristics, the temperature of the absorber, the various power and efficiency. The energy balance is used to determine the thermal characteristics of the absorber in order to calculate the temperature concentrated at the surface captor, in the first absorber, the heat equation is solved by implicit finite difference method and the second from the power output determining a temperature difference between the edges of the coil. The comparison of numerical results with those obtained through an experimental study conducted in parallel, showing good reliability of the computer code developed. © 2011 Published by Elsevier Ltd.
Boukelia T.E.,University of Mentouri Constantine |
Mecibah M.-S.,University of Mentouri Constantine
Renewable and Sustainable Energy Reviews | Year: 2013
Against the background of an increasing energy demand and growing environmental problems in Algeria due to the use of fossil fuels, renewable energy resources offer interesting opportunities for Algeria. In 2011, Algeria has developed a national program for the period 2011-2030 to promote concrete actions in the fields of renewable energies and energy efficiency. This paper gives description and working principles of the parabolic trough power plants, besides a review of considerations on the assessments for concentrating solar power potential of Algeria. The analysis shows the competitive viability of CSP plants. Algeria has the key prerequisites to make an economical CSP power generation; including high-quality insolation and appropriate land in addition to water availability and extensive transmission and power grid. In the end, an overview is given on the parabolic trough power plant projects development in Algeria including the first integrated solar combined cycle Hassi R'mel plant, in addition to the three further hybrid power plants that will be completed by 2018. © 2012 Elsevier Ltd.
Layeb A.,University of Mentouri Constantine
International Journal of Bio-Inspired Computation | Year: 2011
This paper presents a new inspired algorithm called quantum inspired cuckoo search algorithm (QICSA). This one is a new framework relying on quantum computing principles and cuckoo search algorithm. The contribution consists in defining an appropriate representation scheme in the cuckoo search algorithm that allows applying successfully on combinatorial optimisation problems some quantum computing principles like qubit representation, superposition of states, measurement, and interference. This hybridisation between quantum inspired computing and bioinspired computing has led to an efficient hybrid framework which achieves better balance between exploration and exploitation capabilities of the search process. Experiments on knapsack problems show the effectiveness of the proposed framework and its ability to achieve good quality solutions. Copyright © 2011 Inderscience Enterprises Ltd.
Gomri R.,University of Mentouri Constantine
Energy Conversion and Management | Year: 2013
Solar radiation is a clean form of energy and solar cooling systems is one of the technologies which allow obtaining an important energy saving. Natural gas is a cheaper fuel than oil. It also burns cleaner than oil. Natural gas and renewable energy are complementary and in the future, the alignment of natural gas and renewable energy may be the most effective way to service the demand for clean energy. This paper presents a numerical study of solar/natural gas single effect lithium bromide absorption chillers. The development of this system is based on hot water chiller. As auxiliary power, fire from the natural gas burners is used to heat the hot water on its way to the generator. The overall performance of the absorption chiller system is analysed and discussed. For an evaporator temperature of 5 °C and when the condenser temperature is varied from 28 °C to 36 °C and generator temperatures is varied from 54 to 83 °C the maximum COP is 0.82 and the maximum exergetic efficiency is about 30%. For a given condenser temperature there is an optimum generator temperature for which the number of flat plate collectors is minimum. This optimum generator temperature corresponds to the generator temperature giving the maximum COP and exergy efficiency of the absorption cooling system. The solar/natural gas single effect lithium bromide absorption chillers, using solar energy as the energy source with only limited amount of gas as auxiliary power, not only reduces greatly the cost for electricity and operates in regions where there are abundant solar energy and cheap natural gas resources, but also compensates the peak-valley load difference and reduce CO2 gas emissions. For a refrigeration capacity of 10 kW, the quantity of natural gas used to provide auxiliary load is very small and consequently the CO2 gas emissions is very small (the maximum mass flow rate of CO2 is less than 3 kg h-1). © 2012 Elsevier Ltd. All rights reserved.
Djerrou Z.,University of Mentouri Constantine
Chinese Journal of Natural Medicines | Year: 2014
Aim: The current study was undertaken to assess anti-hyperlipidemic activity of Pistacia lentiscus fatty oil (PLFO) in rabbits following a hyperlipidemic diet. Method: Twenty healthy female (WNZ) rabbits were divided into four groups of five animals each: (a) normal control (NC group) receiving standard diet, (b) hyperlipidemic control (EY) group receiving standard diet and gavaged daily with egg yolk (10 mL), (c) hyperlipidemic + PLFO (EY + PLFO) group receiving as the EY group and treated daily with PLFO (2 mL/kg BW, (d) hyperlipidemic + simvastatin (EY + SVS) group receiving as the EY group and treated once daily with 2.5 mg/kg BW of simvastatin. At the end of the six-week experimental period, the lipidemic profiles of the different groups were investigated. Results: In the EY group, the egg yolk resulted in a significant increase of total cholesterol (TC), triglycerides (TG), HDL-C, LDL-C, and the LDL-C/HDL-C ratio. Both the EY + PLFO and EY + SVS groups, when compared to the EY group, showed a significant decrease of TC, TG, LDL-C, and the LDL-C/HDL-C ratio. However, with respect to HDL-C the differences were not significant. The TGs were significantly lower (P < 0.001) in the simvastatin-treated group when compared to rabbits treated in the PLFO group. Conclusion: The study concludes that P. lentiscus fatty oil (PLFO) possesses anti-hyperlipidemic properties at least in reducing total cholesterol, LDL-cholesterol and triglycerides. © 2014 China Pharmaceutical University.
Kaikaa M.Y.,University of Mentouri Constantine |
Hadjami M.,University of Mentouri Constantine
IEEE Transactions on Industrial Electronics | Year: 2014
Many papers are available in the literature about detection of faults in induction machines. However, they generally deal only with a single fault. Instead, in practice, the case of mixed faults is quite common: the simultaneous presence of broken rotor bars and an intrinsic eccentricity or a coupling misalignment occurs often in an induction machine. The aim of this paper is to analyze theoretically and experimentally the stator current of an induction machine operating with mixed faults: broken rotor bars and static eccentricity (SE). First, an analytical expression for the mutual inductances under SE is derived using a mixture of modified winding function and Fourier series approach. Then, both theoretical and simulation studies are presented to show how the stator current is influenced by the simultaneous presence of (SE) and broken rotor bars with the consideration of the speed ripple effect. It is demonstrated that, in addition to the well-known characteristic frequencies of broken bars, and the rotor slot harmonic (RSH) used for the detection of (SE), this kind of mixed fault introduces in the stator current a series of additional harmonics, in the form of sidebands centered around the fundamental and RSH. More important, it is shown that some of these harmonics are similar to the frequencies introduced by the mixed eccentricity. Finally, experimental results have been presented to validate the analytical and simulation results. © 2013 IEEE.