Etat sanitaire du pin maritime en région méditerranéenne.

La cochenille du pin maritime (Matsucoccus feytaudi), spécifique de cet hôte, constitue le plus important problème de l'essence dans l'aire méditerranéenne. Dans le massif des Maures, elle agit en tant qu'agent d'affaiblissement et favorise la colonisation de la pyrale du tronc qui interdit toute valorisation en bois d' uvre. En Corse, l'évolution épidémique depuis 1994 semble atteindre un pallier dans son intensité tout en poursuivant une progression spatiale centrifuge

Les Probabilités Défaillance comme Indicateurs de Performance des Barrières Techniques de Sécurité - Approche Analytique

International audienceFrench environmental laws require industrialists to include probability criteria in risk assessments, especially to define confidence levels for risk management measures. This paper presents the failure probabilities as efficient indicators for technical safety barrier performances. Generic formulas are proposed to evaluate these probabilities, including failure rate, barrier architecture, full and partial proof tests. In many cases, these results can be directly used to assess safety barrier confidence levels

Politiques de Tests Partiels & Systèmes de Sécurité

International audienceA set of general formulas is proposed for the probability of failure on demand (PFD) assessment of MooN architecture (i.e. k-out-of-n) systems subject to partial and full tests. Partial tests (e.g. visual inspections, imperfect testing) may detect only some failures, whereas owing to a full test, the system is restored to an as good as new condition. Following the proposed approach and according to an example, performance estimations of the system and test policies are presented, by using the feedback from partial and full tests. An optimization of the partial test distribution is also proposed, which allows reducing the average probability of system failure on demand (PFDavg)