Dr. Latifa ALIMI

Les composites à matrice polymère sont utilisés en général comme des biomatériaux à cause de leurs constituants. Le matériau analysé est un composite à matrice en polymère renforcé par une fibre de verre utilisé comme prothèse orthopédique d’un tibia. Les résultats obtenus de diffraction des rayons X et spectroscopie Infrarouge à transformée de Fourier(FTIR) montrent la présence de la silice SiO2 et de l’alumine Al2O3 se sont parmi les constituants de la fibre de verre ainsi que la présence des molécules organiques se sont parmi les constituants de la résine polyester.

In orthopedic surgery, the effectiveness of the implants used, such as hip and knee prostheses, depends mainly on their geometries and the type of loading to which they are subjected. In this work a probabilistic approach is chosen to study the reliability of a composite structure used in the manufacture of knee prostheses. The purpose of integrating reliability concepts is to consider uncertainty in several aspects including loading and material properties. The reliability index β is an excellent indication of durability and safety for given operating conditions. β is obtained using failure probability and a mechanical model. The critical stress intensity factor (Kc) is adopted as a criterion to the maximum limit of a numerically calculated KI. The results presented are discussed according to the length of the crack (a), and the limit load used.

In this paper, TiO2 nano-films were deposited by RF magnetron sputtering using a TiO2ceramic target of pureTi of 3" diameter and 0.250" thickness with a purity of 99.99%, onto heated glass substrates in a temperature range of200 to 450°C. This study determines the temperature effect on the structural, optical and morphological properties ofTiO2 nano-films. For this, we used X-ray diffraction for structural characterization and optical transmission spectroscopyUV-Visible for optical characterization and atomic force microscopy (AFM) for morphological characterization of thefilms produced. The (101), (400), (112), (200), (105), (211), (213), (204) peaks of the anatase structure and the (210),(102), (-112) (710) peaks of the monoclinic structure are observed. In addition, the peaks are sharp and intense whichimplies a good crystalline structure. Otherwise, the films optical gap variation is proportional to the temperature variationfrom 3,9eV to 3,92 eV for T=200°C and T=450°C, respectively. The surface roughness of TiO2 nano-films range from1,031nm to 4,665nm.