Origin of the carbon rich sliding interface in alkali containing matrix-SiC Nicalon fibre composites

The interfacial Nicalon SiC/Nasicon matrix reaction and its influence on the micro-and macroscopic mechanical properties have been studied by chemical analysis, EDX, SEM, microindentation, fibre tensile and composite flexural strength. Reaction mechanims and relationships with mechanical properties are discussed. An explanation of the origin of the "C" sliding interphase is proposed

How much can a vibrational diagnostic tool reveal in total hip arthroplasty loosening?

Objective. To investigate how much information a vibrational technique can reveal regarding the loosening of the femoral component of a total hip arthroplasty. Design. Numerical modal analysis using finite element method and computer simulation. Background. Existing work suggested that this technique is capable of revealing total hip arthroplasty loosening. However, the potentials of this technique are not fully studied yet. There is a need to establish the limitation of this technique. Methods. Numerical modal analysis was conducted to obtain the natural frequencies and mode shapes of femoral models under free vibration. An absent interface portion was hypothesized at specified locations the data from modal analysis were then used in a computer simulation to visualize the vibration diagnosis. Results. The effects of interface failure on the femoral component stiffness vary with the locations and sizes of failure. Nominal critical, reliable, and nondetectable levels of interface failure are found. Conclusion. When the size of failure is more than one-third of the stem length, this tool is able to provide a reliable diagnosis. The critical detectable interface failure size is one-fifth of the stem length. It was found that the motion at higher harmonics is the most sensitive to the interface failure. This tool is unlikely to differentiate the slight differences in natural frequencies that occur when the interface failure length is less than one-sixth of the stem length. It is likely to fail in detecting failures located at the stem central portion regardless of their length. Relevance: A numerical study of the vibration tool is important prior to pursuing clinical trials of the tool and may guide the characterizations involved in the trials. © 2003 Elsevier Science Ltd. All rights reserved

Origin of the carbon rich sliding interface in alkali containing matrix-SiC Nicalon fibre composites

To be published in the Journal of Physics IVSIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1993 n.77 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Radio and microwave frequency relaxations and conductivity in superionic Nasicon

8th solid state ionics conference, Lake Louise (Canada), October 20-26, 1991. Journal of solid state ionicsSIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1991 n.207 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Mullite and SiC matrix SiC fibre composites for high temperature application

Tire de : Proceedings of 4th international symposium on ceramic materials and components for engines, Goteborg, June 10-12, 1991SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1991 n.118 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Guidelines of the French Society of Otorhinolaryngology (SFORL). Managing epistaxis under coagulation disorder due to antithrombotic therapy

International audienceOBJECTIVE:The authors present the guidelines of the French Society of Otorhinolaryngology concerning the management of epistaxis during antithrombotic therapy.METHODS:A review of the literature was performed by a multidisciplinary work group. Guidelines were drafted, then re-edited by a reading group independent of the work group to produce the final text. The proposed recommendations were graded A, B, C or expert opinion, on decreasing levels of evidence.RESULTS:Before any decision to modify antithrombotic treatment, it is recommended to screen for overdose and assess the risk of thrombosis. In stented patients, dual antiplatelet therapy must be maintained during the month following stenting and, if possible, for 3 months. In epistaxis with antivitamin K (AVK) overdose controlled by packing, corrective measures are based on the International Normalized Ratio (INR). In uncontrolled epistaxis, it is recommended to stop AVK, administer antidotes and regularly monitor INR. In case of intravascular embolization, it is not recommended to alter anticoagulant treatment