Les politiques de formation professionnelle continue dans l'entreprise

Available at INIST (FR), Document Supply Service, under shelf-number : RP 13493 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Contribution a l'etude des lois d'interaction sol-pieu pour l'analyse des essais de battage de pieux

SIGLECNRS-CDST / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Measuring and modeling the (limited) consistency of free choice attitude questions

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : DO 7683 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Assessing the bioavailability of black carbon-derived dissolved organic matter for marine heterotrophic prokaryotes

Here we investigated the bioavailability of black carbon (BC)-derived dissolved organic matter (DOM) for a natural mixed community of marine heterotrophic prokaryotes. We ran an in vitro biodegradation experiment that took place over 3 months and exposed a community of organisms collected in the northwestern Mediterranean Sea (Bay of Marseille, France) to three different soluble fractions of BC prepared in the laboratory from various fossil fuel combustion particulates: standard diesel (DREF), oxidized diesel (DREF-OX), and natural samples of ship soot (DSHIP). Over the course of the three months, we observed significant decreases in the concentrations of dissolved organic carbon (DOC; from 9 to 21 %), dissolved BC (DBC; from 22 to 38 %) and dissolved polycyclic aromatic hydrocarbons (d-PAH; from 24 to 64 %) along with variability in the growth dynamics and activity of the heterotrophic prokaryotic community. The heterotrophic prokaryotic community exposed to DREF-OX treatment showed the highest values of respiration and production and the highest cell abundance, associated with the highest decrease in DOC (21 %) and d-PAH (64 %) concentrations. In the DREF and DSHIP treatments, prokaryotic activity was oriented towards anabolism. DREF treatment led to the highest decrease in DBC concentration (38 %). DSHIP treatment, which presented a substantially different d-PAH and dissolved metals content to the other two treatments, showed the lowest decreases in DOC, DBC and d-PAH concentrations, as well as the lowest prokaryotic activity and biomasses. Our results indicate that BC-derived DOM, including the most condensed fraction of this material, is partly bioavailable and therefore likely to be assimilated by marine prokaryotes. The origin of BC/soot deposited at the ocean surface turns out to be a key parameter that dictates the efficiency of biodegradation of its dissolved fraction by heterotrophic prokaryotes

Characterisation of electron beam welded aluminium alloys

Electron beam (EB) welding was performed on three different aluminium alloys, namely alloys 2024, 5005, and 6061 (plate thickness 5 mm except alloy 5005 which was 3 mm in thickness), to establish the local microstructure-property relationships that would satisfy the service requirements for an electron beam welded aluminium alloy component with weld zone strength undermatching. Microstructural characterisation of the weld metals was carried out by optical and scanning electron microscopy. A very low level of porosity was observed in all EB welds owing to surface cleaning before welding and the vacuum environment of the EB welding process. Extensive microhardness measurements were also conducted in the weld regions of the joints. Global tensile properties and fracture toughness properties (in terms of crack tip opening displacement, CTOD) of the EB joints were determined at room temperature. The effects of strength mismatch and local microstructure on fracture toughness of the EB joints are discussed. The purpose of the present paper is to report the partial results of the European Brite-Euram project ASPOW (assessment of quality of power beam weld joints; BRPR-CT95-0021), which has been undertaken predominantly by industrial companies to establish a European framework for destructive and non-destructive testing and assessment criteria for laser and electron beam welds of over 20 metallic materials. (orig.)Also published in: Science and Technology of Welding and Joining, v. 4(1990), no. 5, p. 317-323Available from TIB Hannover: RA 3251(2001/1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman