Une analyse constructive des attitudes, des politiques et des programmes en ce qui concerne la radicalisation

CONRA

CONDUCTIVITY MEASUREMENTS ON UHV DEPOSITED AMORPHOUS SILICON

Conductivity has been investigated on UHV deposited a-Si thick films as a function of spin concentration. Results are analysed using Mott's VRH theory and can be described by laws of the form σ = σ0 exp -(T0/T)1/4 The variations of T0 and σ0 with spin concentration are presented. Relations between ESR signal linewidth, longitudinal relaxation time T1, and conductivity are investigated. In addition to a spin-lattice relaxation rate process of the form T-11 α T we evidence another contribution which is proportional to dc conductivity

De pedagogische kracht van een trektocht in de bergen

status: Published onlin

Tournemire argillite/carbon steel evolution under bacterial influence after 10 years of in situ interaction

International audienceThe purpose of the present study was to characterise the physicochemical evolution of argillite/carbon steel coupons after 10 years of interaction inside the Tournemire Underground Research Laboratory (France). Carbon steel coupons were introduced in boreholes drilled in the geological formation in contact with the argillite, and were overcored 10 years later to study the interfaces. The iron release by steel corrosion induced mineralogical dissolutions (Ca phases) and precipitations (iron oxides and hydroxides), leading to a partial clogging of the argillite porosity. A sulphur enrichment was observed in the corrosion area, linked to a potential microbial activity. The biodiversities differed depending on the steel type, indicating the influence of iron-clay interactions. This analysis has shown the presence of bacteria known for their involvement in corrosion processes and isolates able to develop at elevated temperatures. © 2014 Institute of Materials, Minerals and Mining