Xanthene derivatives of the 14-aryl-14H dibenzo[a.j] xanthene type were exploited in our study because of their interesting biological profile as well as their innumerable applications described in previous studies. They were synthesized by one-pot condensation of β�-naphthol with arylaldehydes and catalyzed by zinc trifluoromethanesulfate Zn(OTf)2 under conventional heating without solvent. Their characterization was carried out by Ultraviolet–Visible spectrophotometry (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). First, spectral analysis in the UV–Vis range showed that all xanthene derivatives had similar absorption spectra at an absorption maximum (λmax)(�max) in the region of 310–340nm. Similarly, the infrared spectra suggested the presence of characteristic bands for each product in the range of 500–3500cm−1−1. In addition, the analysis of their crystalline structures was carried out by the XRD technique and reported in our study. Finally, their sizes and morphologies were highlighted by SEM. The obtained results revealed the presence of microcrystals in the form of micro-cubes having an average length of 10μ�m for the compound C2727H1818O and micro-shuttles of average size of 20μ�m for the compound C2727H1717BrO. It was therefore concluded that the xanthene derivatives synthesized have characteristic functional groups and structures which will provide them with various therapeutic properties and can therefore be exploited as bioactive molecules in several fields.

A nanometric buried layer of iron disilicide was synthesized by ion implantation in Si(1 1 1) p-type at different temperatures using 195 keV Fe ions with a dose of \(2\).\(10^{17}\)\(Fe^{+}/cm^{2}\). The investigation of the phase composition is carried out by
Rutherford backscattering spectrometry (RBS), whereas the structural characterization is obtained by X-ray diffraction (XRD) pole figure. The process of the silicidation has been investigated at a function of the ion implantation temperatures ranging from 200 to 440 °C. The precipitates favor epitaxial growth with respect to Si(1 1 1) planes with epitaxial relationships \( \beta\)-FeSi\(_{2}\)(2 2 0) //Si(1 1 1) and/or \(\beta\)-FeSi\(_{2}\) (2 0 2) // Si(1 1 1).
 

Nanometric YSi_2 − x yttrium silicides layers have been formed onto a Si(111) single-crystal substrate by implantation at room temperature (RT) of Y ions using an energy of 195 keV and a dose of 2 × 10¹⁷ Y⁺/cm² followed by a thermal annealing in a nitrogen atmosphere. The process of the silicidation has been investigated at a function of the annealing temperatures ranging from 600 to 1000 °C for duration of one hour. The characterization of the samples has been performed using X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), and scanning electron microscopy combined with energy dispersive X-ray spectrometer (SEM-EDS) techniques. Studies have shown that the YSi_2 − x layer is epitaxially grown on the Si (111) surface, and after thermal annealing at a temperature of 600–1000 °C, no change in the properties of the formed phase is found.

Cet ouvrage destiné aux étudiants en:

- 1ière, 2ème & 3ème Année Sciences Médicales (Médecine, Pharmacie et Chirurgie Dentaire)

- Paramédical (Radiologie, hygiène, PPH)

- Vétérinaire

- Biologie 

-SM (1ière+2ème+3ème Année)

-ST (1ière Année)

 

International Atomic Energy Agency (IAEA)

 

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