Vol 04, N 02
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Item Investigation Of Ingan/si Double Junction Tandem Solar Cells(University of Eloued جامعة الوادي, 2012-07-01) Bouzid, F.; Hamlaoui, L.In this work, the solar power conversion efficiency of InGaN/Si double junction tandem solar cells was investigated under 1-sun AM1.5 illumination, using realistic material parameters. With this intention, the current-voltage curves are calculated for different front recombination velocities and the influence of the bottom cell thickness on efficiency has been studied. The results show that a front recombination velocity value of 1e3cm/s is most advantageous and the use of relatively thick bottom cell is necessary to obtain conversion efficiency greater than 27%, at 300°k cell temperature. This efficiency will decrease as the operating temperature increase.Item Structural Stability And Electronic Structure Of Ycu Ductile Intermetallic Compound By First-principal Calculation(University of Eloued جامعة الوادي, 2012-07-01) Sekkal, A.; Benzair, A.We investigate the structural, elastic and electronic properties of cubic YCu intermetallic compound. Which crystallize in the CsCl- B2 type structure, the investigated using the first principle full potential linearized augmented plane wave method (FP-LAPW) within density functional Theory (DFT). We used generalized gradient approximation (GGA) and local density theory (LDA), which is based on exchange correlation energy optimization, are used to determinate the total energies and the electronic band structures. The latter provide us with the ground states properties such as lattice parameter, bulk modulus and its pressure derivative, elastic constants and the structural phase stability with respect to the B1, B3, and L10structures of this compound. Our results are in good agreement with numerous experimental and theoretical data where available.Item Effect For A Single Roughnessε = 9,11mm Of Experimental To Study Hydraulic Jump Profile In A Channel In U A Rough Bottom(University of Eloued جامعة الوادي, 2012-07-01) Ghomri, A.; Riguet, F.; Debabeche, M.This study aims to study the hydraulic jump controlled by threshold, moving in a channel profile 'U' bottomed rough for a single roughness ε = 9,11mm. Functional relations in dimensionless terms, linking the different characteristics of the projection, showing the effect of roughness of the bottom of the channel are obtained.Item Phytochemical Analysis, Antioxidant And Antimicrobial Activities Of Leaves Extract Of Date Palm Grown In Algeria(University of Eloued جامعة الوادي, 2012-07-01) Laouini, S. E.; Segni, L.; Ouahrani, M. R.; Gherraf, N.; Mokni, S.In this study, we have determined the phenolic compounds, antioxidant and antimicrobial activity of methanolic extracts from three varieties of leaves tree. According to the results the leaves extracts have very important values for polyphenols (215.24 to 156.46 mg GAE / g DW) and high antioxidant activity (324. 45 to 206.21 mg GAE / g DW), DPPH (IC50 = 2.98 to 4.83 μg / ml) and β-bleaching test (IC50 = 133. 93 to 194. 12 μg / ml); also the three extracts reveal a considerable antimicrobial potency and antifungal considerable activity , the diameter of inhibition is 14.4 ± 0.6 mm for Hamraya, 19.8 ± 0.5 mm for Ghars and 17.4 ± 0.8 mm for Deglet Nour (concentration 50 mg / ml) from Staphylococcus aureus ATCC.Item Chemical Composition And Antioxidant Activity Of Apis Mellifera Bee Pollen From Northwest Algeria(University of Eloued جامعة الوادي, 2012-07-01) Rebiai, A.; Lanez, T.The aim of this study was to assess the nutritional compositionand antioxidant activity of bee pollen produced in the North western region of Algeria.The content of total phenolic compounds,flavonoids, and antioxidant activity using the molybdate ion reductionmethod were determined. The meancontents of phenolic compounds and total flavonoids were 30.46 ± 8.22 mgof GAE.g–1 pollen and 8.92 ± 5.5 mg of RE.g–1 pollen, respectively. Highantioxidant activities were found for the molybdate ion reductionmethod, with values that ranged from 71.95 to 101.5μg of GAE.g–1 pollen. The bee pollen ofBoufarikshowed high antioxidant activity probably due to the high contentof phenolic compounds present in pollen.Item Study Of Antioxidant Capacity Of Different Parts Of Two South Algerian Eggplant Cultivars(University of Eloued جامعة الوادي, 2012-07-01) Boubekri, C.; Rebiai, A.; Lanez, T.In this study the antioxidant capacity of ethanolic EE and water WE extracts fromdifferent parts (calyx, peel, and pulp) of eggplant (Solanum melongena L) were evaluated using cyclic voltammetry.The antioxidant capacity of different parts of eggplant was measured using ascorbic acid equivalent antioxidant capacity assays. The peel extracts of both dark purple and white samples showed the highest antioxidant capacity (66.78and 75.62 mg/g) followed by pulp (16.54 and 30.56 mg/g), and calyx (14.82 and 21.27 mg/g). These results indicate that antioxidant capacity of eggplant varied by parts and solvents.Item Study Of Reaction Sequences For Formation Of Solid Solution: 0,48 Pbzro3-0,47 Pbtio3-0,05 Pb (cr1/5, Zn1/5, Sb3/5) O3(University of Eloued جامعة الوادي, 2012-07-01) Abdessalem, N.; Necira, Z.; Abbaand, M.; Boutarfaia, A.To study the reaction sequences of formation of solid solution zirconate-lead titanate (PZT) in this work, we took into account the effect of adding oxide dopants on the progress of the reaction, so we added oxides ZnO, Cr2O3,Sb2O3 to our material composition in small quantities so that the solid solution must verify the conditions of the perovskite structure. The results of the X-ray diffraction and thermal analysis allowed us to suggest a reaction mechanism. It is important to note that the substitution of a low concentration of ions forming the perovskite structure PZT (Pb2+, Zr4+ et Ti4+) by other ions (Zn2+, Cr3+ et Sb+5 in our study) alters the reaction sequences training of the solid solution PZT and especially the formation of intermediate phase.Item Corrosion Inhibition Of Carbon Steel Xc70 In H2so4 Solution By Ferrocenederivative3- (ferrocenylmethylamine) benzonitrile(University of Eloued جامعة الوادي, 2012-07-01) Zaiz, T.; Lanez, T.In this work, we studied the efficiency of corrosion inhibition of carbon steel XC70 in H2SO4 0.5 M aqueous solution using ferrocenyl derivativessynthesized in our laboratory, this compound is: 3-(ferrocenylmethylamine)benzonitrile. The inhibitory potential of this compound was determined by electrochemical techniques based on Tafel segments. The results show that the studied compound has an efficiency of inhibition which depends on its concentration.The adsorption of these compounds on the surface of the metal is a chemical adsorption. The inhibition of corrosion reached 84 % at a concentration of 50 ppm.Item Method Of Particle Characterisation; Morphology By Image Analysis(University of Eloued جامعة الوادي, 2012-07-01) Belaroui, K.; Pons, M. N.The aim of our work is to establish a morphological characterization of particles. The particle size analysis determines the size distribution of a population of particles using a laser granulometer device. The evolution of particle size distributions is complemented by a study on the particle shape. Thus, morphological analysis consists to acquire images of the particles by using a scanning electron microscopy which will be then processed using an algorithm. The treatment is a set of operations that are thresholding, erosion, expansion and reconstruction of the image. Data processing is performed based on a set of dimensional parameters.Item Rheology And Scaling Behavior Of Swelling Clay Dispersions(University of Eloued جامعة الوادي, 2012-07-01) Chaoui, S.; Mehamha, A.; Belkham, N. H.; Benachour, D.The microstructure and scaling of rheological properties of colloidal gels of bentonite investigated as a function of volume fraction and strength of interparticle interaction over a range of volume fractions, elastic modulus is well described with a scaling law functions of volume fractions, while the role of interparticle attractions can be accounted for by expressing these rheological properties as (/g-1)n, where g captures the strength of particle interaction and n the microstructure. The scaling variable (p/pc-1), suggested in percolation theory to describe rheological behavior near percolation transition, acts to collapse G’ data suggesting that along lines of constant (/g-1) these gels are rheologically identical.Item Characterizations Energy And Environmental Of The Biomethanation Pilot Applied On The Animal Droppings(University of Eloued جامعة الوادي, 2012-07-01) M’sadak, Y.; Zoghlami, R.; Baraket, S.This study interested in monitoring energy (quantitative and qualitative) and environmental performances at various pilot digesters of animal biomass. Main results are: The combined effect of the diet and the substrate on quantitative experimental productivity of gas is in favor of poultry digesters continuously fed. The biogas produced has better potential especially in industry. The environmental evaluation virtually shows a certain interest on the depollution for industrial digester.