The F2 wind tunnel at Fauga-Mauzac

Details on the French subsonic wind-tunnel F2 that becomes operational on July 1983 are presented. Some of the requirements were: (1) installation of models on any wall of the facility, (2) good observation points due to transparent walls, (3) smooth flow, (4) a laser velocimeter, and (5) easy access and handling. The characteristics include a nonpressurized return circuit, dimensions of 5 x 1.4 x 1.8 m, maximum velocity of 100 m/s and a variable speed fan of 683 kW

Reliability of metal/glass-ceramic junctions made by solid state bonding

The solid state diffusion bonding leads to helium-tight ceramic-metal junctions. However this technique induces residual stresses due to expansion mismatches which may cause ceramic flaws to propagate hence junction delayed failure. This phenomenon is evidenced on glass-ceramic/Al/Invar junctions from which a better reliability is ensured by a reduction of surface flaws

RELIABILITY OF METAL/GLASS-CERAMIC JUNCTIONS MADE BY SOLID STATE BONDING

L'assemblage par diffusion dit par thermo-compression permet de réaliser des liaisons céramique-métal étanches à l'hélium. Ce procédé engendre cependant des contraintes résiduelles d'origine thermique sous l'action desquelles les défauts de la céramique peuvent se propager et conduire à la rupture différée de l'assemblage. Ce phénomène est mis en évidence sur des assemblages vitrocéramique/Al/Invar où une meilleure fiabilité est assurée par une réduction des défauts de surface.The solid state diffusion bonding leads to helium-tight ceramic-metal junctions. However this technique induces residual stresses due to expansion mismatches which may cause ceramic flaws to propagate hence junction delayed failure. This phenomenon is evidenced on glass-ceramic/Al/Invar junctions from which a better reliability is ensured by a reduction of surface flaws

Predicting deep venous thrombosis in pregnancy: externalvalidation of the "left" clinical prediction rule.

International audienceBackground. The assessment of clinical probability represents an important step in the diagnostic strategy of patients with suspected deep vein thrombosis. The recently derived "LEFt" clinical prediction rule for pregnant women combines three variables: symptoms in the left leg ("L"), calf circumference difference ≥ 2 centimeters ("E" for edema) and first trimester presentation ("Ft"), but is lacking an external validation. Design and Methods. The LEFt rule was computed among pregnant women with suspected deep vein thrombosis who were included in a multicentre prospective diagnostic management outcome study. We calculated the proportion of women and the prevalence of deep vein thrombosis in each probability group, along with the diagnostic performances of the LEFt rule. Results. All variables needed to compute the rule could be retrieved in 157 out of the 167 pregnant women with suspected deep vein thrombosis. The prevalence of confirmed deep vein thrombosis was 13/157 (8.3%). The "LEFt" rule was negative in 46 (29%) women. A deep vein thrombosis was diagnosed in 13/111 (11.7%, 95% CI: 8.3 to 20.9%) of women with at least one of the "LEFt" criteria, as compared with 0/46 (0.0%, 95% CI:0.0 to 7.9%) of women with none of the "LEFt" criteria. Conclusions. These results suggest that a negative "LEFt" rule accurately identifies pregnant women in whom the proportion of confirmed deep vein thrombosis appears to be very low. The rule should not be used as stand-alone test for excluding DVT during pregnancy but might rather be implemented in a diagnostic strategy in association with Ddimer measurement and compression ultrasonography

Nouveaux moyens d'essais hypersoniques developpes a l'ONERA Les souffleries R5 et F4

Communication au Symposium AGARD 'Theoretical and experimental methods in hypersonic flows', Turin (Italie), 4-8 mai 1992Available at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1992 n.39 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc