Journals of Kasdi Merbah Ouargla University
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STRENGTHENING OF ALUMINIUM-COPPER ALLOYS THIN FILMS
No full textWe have modelled, from characteristics of aluminium and its alloying elements, the microhardness evolution of sputtered on glass slides aluminium-copper alloys deposits. This one regularly increases with the copper concentration from 1300 MPa for sputtered pure aluminium, reaches a maximum of about 8500 MPa corresponding for 49 at.%Cu and then decreases till sputtered pure copper estimated about 2300 MPa. Such films, with a hardness higher than for corresponding conventional alloys, can be used as hard coatings for these alloys This phenomenon of significant mechanical hardening of aluminium by the means of transition elements is attributed essentially to a simultaneous effect of solid solution and grain size refinement due to the difference in the size of the atoms of the solvent and the solute
ETUDE STRUCTURALE D¢UN COMPLEXE TÉTRANUCLÉAIRE TRI-THIO FER CARBONYLE :[FE(CO)3]4[S-C(CH3)=C(CH3)-CS2 PRÉSENTANT DES PONTS FER-FER ET FER-SOUFRE
No full textParmi les composés de coordination des métaux de transition, les métaux carbonyles représentent un groupe de molécules particulièrement étudiées en raison la richesse de leurs propriétés chimiques et la variété de leurs filiations. Ces composés sont actuellement de plus en plus utilisés dans la synthèse de nouveaux édifices moléculaires qui présentent des propriétés électroniques intéressantes en chimie de coordination. L’objet de la présente étude a donc consisté dans un premier temps à rechercher des ligands pouvant être greffés facilement sur des molécules organiques susceptibles de conduire à des complexes avec le fer carbonyle
The impact of the internal mechanisms of governance on the financial performance-an econometric study using a sample of Tunisian commercial banks during the period (2010-2016)
Full text linkThis study aims to determine the impact of internal governance mechanisms on the financial performance of Tunisian commercial banks during the period 2010-2016, for a sample of seven commercial banks operating in Tunisia. While using: the three independent variables namely, board size, the number of independent board members and the ownership concentration, as well as the two dependent variables which are the return on assets '' ROA '' and the return on equity '' ROE ''. Using a panel data model approach. The study found that there is a negative impact of statistical significance between the size of the Board of Directors and the performance of banks, and a statistically significant positive effect between the number of independent board members and ROE