Conservatoire national des arts et métiers

About: Conservatoire national des arts et métiers is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Context (language use). The organization has 3573 authors who have published 7127 publications receiving 141430 citations. The organization is also known as: CNAM & Conservatoire des arts et métiers.

Prevalence and factors associated with hidradenitis suppurativa: Results from two case-control studies

Abstract: Background Conflicting opinions have been reported regarding the epidemiology of hidradenitis suppurativa. Objective We sought to evaluate the prevalence of hidradenitis suppurativa and to identify associated factors. Methodology Prevalence was evaluated using a representative sample of the French population (n = 10,000). Associated risk factors were assessed using two case-control studies, one population-based with 67 self-reported patients and 200 control subjects, and the other clinic-based with 302 medically assessed patients and 906 control subjects. Results The prevalence was 1% of the French population. Multivariate analyses showed a strong association with current smoking in self-reported (odds ratio=4.16, 95% confidence interval [2.99-8.69]) and in medically assessed (odds ratio=12.55 [8.58-18.38]) populations. Association with body mass index was significant in medically assessed patients (odds ratio=1.12 [1.08-1.15]) for each increase of 1 U of BMI. Limitations A causal relationship could not be established with such a cross-sectional study. Conclusion Hidradenitis suppurativa is a common disease, frequently associated with smoking and being overweight.

There is no infinite fatigue life in metallic materials

Abstract: Generally, the shape of the S-N curve beyond 10 7 cycles is unknown except in some statistical approaches, and this is also true for the fatigue limit. In the case of a statistical approach, the standard deviation applied to the average fatigue limit is certainly not the best way to reduce the risk of rupture in fatigue. Only the exploration of the life range between 10 6 and 10 10 cycles will create a safer basis for modelling. Today, some piezoelectric fatigue machines are very reliable, capable of producing 10 10 cycles in less than 1 week. We based our research on accelerated fatigue tests which were performed at 20 kHz in the gigacyclic fatigue regime in order to study several typical alloys from the aeronautical and space industries.

New determination of the fine structure constant and test of the quantum electrodynamics.

Abstract: We report a new measurement of the ratio $h/m_{\mathrm{Rb}}$ between the Planck constant and the mass of $^{87}\mathrm{Rb}$ atom. A new value of the fine structure constant is deduced, $\alpha^{-1}=137.035\,999\,037\,(91)$ with a relative uncertainty of $6.6\times 10^{-10}$. Using this determination, we obtain a theoretical value of the electron anomaly $a_\mathrm{e}=0.001~159~652~181~13(84)$ which is in agreement with the experimental measurement of Gabrielse ($a_\mathrm{e}=0.001~159~652~180~73(28)$). The comparison of these values provides the most stringent test of the QED. Moreover, the precision is large enough to verify for the first time the muonic and hadronic contributions to this anomaly.

Gigacycle fatigue in mechanical practice

Abstract: Written by pioneers in the study and analysis of very high cycle fatigue, Gigacycle Fatigue in Mechancal Practice compiles the most recent findings on gigacycle fatigue phenomena, focusing on improving the reliability and performance of key engine and machine components. This reference reflects the explosion of new concepts, testing methods, and data on very high cycle fatigue and collects the latest analytical methods and results from renowned authorities on the subject. The authors showcase recently developed technologies for improving performance and preventing fatigue in long-life cars, aircraft engines, high-speed trains, commercial power generators, and ships.