Atomic scale characterization of the nucleation and growth of SnO2 particles in oxidized CuSn alloys

The internal oxidation of Sn was investigated to understand the oxidation kinetics of monophase CuSn alloys. SnO2 particles were characterized by analytical transmission electron microscopy. The orientation relationship between SnO2 and Cu was determined with a special emphasis on the atomic scale structure of Cu/SnO2 interfaces (misfit dislocations and chemical structure). Habit planes with a pure oxygen plane terminating the SnO2 phase are greatly favored and large misfits promote the growth of plate shaped precipitates

Influence des polluants atmosphériques SO2 et NO2 sur la formation des patines de cuivre

International audienc

Influence des polluants atmosphériques SO2 et NO2 sur la formation des patines de cuivre

International audienc

The Verifiability Approach: A Meta-Analysis of Published Studies and a Test of a Decline Effect

Liars are caught in a paradox: they want to provide details to be credible but not so many they could be discovered being untruthful. The verifiability approach assumes that liars include fewer verifiable details, more unverifiable details (or a similar amount), and a lower proportion of verifiable details than truth-tellers. This meta-analysis included 17 published studies, resulting in an overall medium veracity effect for the number (gu = 0.64, gu = 0.55 without outlier) and the proportion of verifiable details (gu = 0.66). No veracity effect was found for the unverifiable details. The type of lie, the use of an information protocol, and the type of statement moderated the veracity effect on the verifiability approach. No effect was found for motivation. A decline effect only appeared for the number of verifiable details. Recommendations for future studies and field applications are discussed

Non-equilibrium radiation during SiC-CO2 plasma interaction

WOS:000373622900014International audienceThe radiation of a pure CO2 inductive plasma was recorded between 190 and 920 nm during its interaction with a SiC sample under a pressure equal to 6 kPa and an estimated global specific enthalpy close to 12 MJ kg(-1). The plasma electronic excitation was found to be out of equilibrium. The main radiators were found to be O, C, C-2 and, mainly, CO. The radiation is especially significant where the plasma chemically interacts with the material revealing a stronger electronic excitation close to the surface. Excitation temperatures were also found to increase in the chemical boundary layer, which is four times smaller than the thermal boundary layer. This raises questions about the energy exchange processes of the excited states and about chemical behaviour independent of their respective ground states. The surface is found to be covered by an inhomogeneous silica layer revealing a passive oxidation, but also by bubble structures, indicative of the transition towards active oxidation. The surface temperature is estimated to be 1800-1900 K. Raman spectroscopy measurements on the surface and optical spectroscopy measurements in the boundary layer provide proof of carbon production coming from the SiC

Simultaneous copper runoff and copper surface analysis in an outdoor area

International audienc

Non-equilibrium radiation during SiC-CO2 plasma interaction

WOS:000373622900014International audienceThe radiation of a pure CO2 inductive plasma was recorded between 190 and 920 nm during its interaction with a SiC sample under a pressure equal to 6 kPa and an estimated global specific enthalpy close to 12 MJ kg(-1). The plasma electronic excitation was found to be out of equilibrium. The main radiators were found to be O, C, C-2 and, mainly, CO. The radiation is especially significant where the plasma chemically interacts with the material revealing a stronger electronic excitation close to the surface. Excitation temperatures were also found to increase in the chemical boundary layer, which is four times smaller than the thermal boundary layer. This raises questions about the energy exchange processes of the excited states and about chemical behaviour independent of their respective ground states. The surface is found to be covered by an inhomogeneous silica layer revealing a passive oxidation, but also by bubble structures, indicative of the transition towards active oxidation. The surface temperature is estimated to be 1800-1900 K. Raman spectroscopy measurements on the surface and optical spectroscopy measurements in the boundary layer provide proof of carbon production coming from the SiC

Influence of crystalline defects on nitrogen implantation in copper for surface hardening

International audienceThe design of electrical contacts that combine a high electrical conductivity and excellent wear resistance requires the optimization of surface processing. Surface hardening of copper was achieved by nitrogen implantation and the underlying mechanisms were investigated by electron microscopy. Pure copper and a CuSn alloy were implanted with nitrogen in the recrystallized state and after severe plastic deformation. The larger lattice parameter of CuS

Atmospheric corrosion of nickel in various outdoor environments

International audienc