Effects of CO2-H2O dilution on the characteristics of CH4-air-O2 flames

International audience Study of non-premixed turbulent flames stabilized by a swirler Control of pollutant emissions / emissions standards Improve performances of combustion plants Investigations on flame characteristics Effects of oxygen enrichment Effects of steam and CO2 dilution Effects of swirl intensit

Structural properties of GaAsN/GaAs quantum wells studied at the atomic scale by cross-sectional scanning tunnelling microscopy

The nitrogen distribution in GaAsNGaAs quantum wells _QWs_ grown by molecular beam epitaxy is studied on the atomic scale by cross-sectional scanning tunneling microscopy. No nitrogen clustering is observed in the range of N contents studied _between 1.0% and 2.5%, as measured by counting the individual N atoms inside the QW_. Nevertheless, the upper interface roughness increases with the amount of N. A residual N concentration in the GaAs barriers is found, which strongly increases with the amount of N in the QW

Los arenales costeros del litoral catalán (la bahía de Rosas)

[ES] Se distinguen dos fuentes para los minerales pesados que se encuentran en las playas de la bahía de Rosas: los basaltos de Olot, para la augita, olivino e hiperstena y las rocas metamórficas del macizo de los Alberes y Cabo de Creus de donde proceden la andalucita, silimanita y distena. La distribución de los minerales, se explica por el transporte efectuado por las corrientes de deriva, los temporales y el viento. Las anomaiías en la distribucidn de algunas especies se deben a los accicentes del terreno y a las condiciones dinámicas muy activas de la bahía, que afectan a la seleccidn de minerales.[EN] The heavy minerals of Gulf of Rosas coastal sand have two different sources. The more frequent heavy minerals are augite and olivine which come from Olot basalts. The metamorfic association is presented by andalusite, siliimanite and kyanite and they come from the metamorfic rocks of the Pyrenees and Cap of Creus massif. Homblende can have two origins: the metamorfic and the granitic rocks of river Muga basin.Peer reviewe

The evolution with strain of the stored energy in different texture components of cold-rolled if steel revealed by high resolution X-ray diffraction

During the deformation of low carbon steel by cold-rolling, dislocations are created and stored in grains depending on local crystallographic orientation, deformation, and deformation gradient. Orientation dependent dislocation densities have been estimated from the broadening of X-ray diffraction lines measured on a synchrotron beamline. Different cold-rolling levels (from 30% to 95% thickness reduction) have been considered. It is shown that the present measurements are consistent with the hypothesis of the sole consideration of screw dislocations for the analysis of the data. The presented evolutions show that the dislocation density first increases within the α fiber (={hkl}) and then within the γ fiber (={111}). A comparison with EBSD measurements is done and confirms that the storage of dislocations during the deformation process is orientation dependent and that this dependence is correlated to the cold-rolling level. If we assume that this dislocation density acts as a driving force during recrystallization, these observations can explain the fact that the recrystallization mechanisms are generally different after moderate or large strains

La0.7Sr0.3MnO3 thin films on SrTiO3 and CaTiO3 buffered Si substrates: structural, static, and dynamic magnetic properties

International audienceNearly 50-nm thick La0.7Sr0.3MnO3 (LSMO) films were grown on Si substrates using molecular beam epitaxy on (001) Si substrates overlayered by a 20 nm thick SrTiO3 (STO) or by a 20 nm thick CaTiO3 (CTO) film. In addition, a reference LSMO film was directly deposited on a (001) STO substrate by pulsed laser deposition. For all the samples, X-ray diffraction revealed an excellent epitaxy of the LSMO film and small mosaicity around (001), with in-plane [100] and [010] cubic axes. The LSMO/CTO films are in-plane compressed while the LSMO/STO ones are in-plane extended. The temperature dependence of their static magnetic properties was studied using a SQUID, showing a Curie temperature overpassing 315 K for all the samples. Hysteresis loops performed at room temperature (294 K) with the help of a vibrating sample magnetometer (VSM) are also discussed. At 294 K Micro-strip ferromagnetic resonance (MS-FMR) was used to investigate the dynamic magnetic properties. It allows concluding to a strong anisotropy perpendicular to the films and to a weak fourfold in-plane anisotropy with easy axes along the [110] and [1 10] directions. Their values strongly depend on the studied sample and are presumably related to the strains suffered by the films