Sources of error and limits of applying the energetic-based-regularization method

In this work, the energetic regularization technique based on the Crack Band approach is studied. The main objective is to identify the sources of errors related to the application of such technique under 2D and 3D computational analysis. Mathematical developments and numerical simulations are proposed in order to assess the limits of application of this technique

Chemical analysis of the essential oils of three cistus species growing in North-West of Algeria

The study reports for the first time the chemical composition and the antibacterial activity of the essential oil hydrodistilled from three Cistaceae growing in Algeria: Cistus ladaniferus L., C. albidus L. and C. monspeliensis L. The oils were analyzed by GC-FID and GC-MS analyses. The major components of C. ladaniferus were 5-epi-7-epi-α-eudesmol (13.6%) and borneol (12.5%) whereas for C. albidus the main constituents were epi-α-bisabolol (11.4%) and β-bourbonene (8.7%). Epi-13-manoyl oxide (28.6%), kaur-16-ene (8.1%) and nonanal (5.4%) were the principal ones for C. monspeliensis. In vitro, antimicrobial activity of the oils was investigated against nine microorganisms by disk diffusion and agar dilution assays. The Gram-positive bacteria resulted sensitive to the three oils, especially Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 25923. The volatiles of C. monspeliensis showed the best activity compared with other oils, comparable to or better than Gentamicin, a conventional antibiotic used as positive control in this study. The minimum inhibitory concentration (MIC) value of the oil was 0.25μg/L

Study of Cu/In/Se/Se thin films prepared by the Stacked Elemental Layer (SEL) technique

CuInSe2 thin films have been grown on Corning glass and Si (100) substrates using stacked elemental layers (SEL) processing. The influence of substrate’s nature and substrate’s temperature were studied. X-ray diffraction and SEM measurements have shown that the films exhibit an excellent crystallinity and crystallize in a tetragonal structure. Scanning electron microscopy investigations have shown that the films consist in a structure with large grains in the range 80 – 200 nm. Increasing the deposition temperature from room temperature to 300 °C has lead to a change in the composition and morphology of the films. Characteristic peaks of the chalcopyrite structure such as (101), (211) and (311) were clearly observed for both layers upon annealing at 450°C as evidenced by X-ray diffraction study. The determined lattice parameters were a = 0.57725 (6) nm, b = 1.1621 (2) nm for sample prepared at room temperature and a = 0.57770 (4) nm, b = 1.1602 (1) nm for Ts = 300°C. The crystallographic structure of the CuInSe2 sample was analyzed by Rietveld analysis using X-ray powder diffraction data. UV-Vis-NIR Spectrophotometry was used to investigate the optical characteristics of different Cu/In/Se/Se thin layers in the spectral range between 300 – 2000 nm. The optical band-gap of our materials increases from 0.98 to 1.01 eV