Etude par diffraction neutronique des composés Mn23Y6D x

Neutron diffraction experiments have permitted us to locate hydrogen (deuterium) atoms in the compounds Mn23Y6Dx, x = 8.3; 18; 23 whose magnetic behavior is appreciably different from that of the alloy Mn23Y6. No evidence of a Mn-Mn critical distance corresponding to a Pauli-paramagnetic behavior of the hydride (deuteride) has been found.La localisation des atomes d'hydrogène (deutérium) a été déterminée par diffraction neutronique sur les phases de composition Mn23Y 6Dx, x = 8,3; 18; 23, dont le comportement magnétique est sensiblement différent de celui de l'alliage Mn23Y 6. On montre qu'il n'existe pas de distance critique Mn-Mn au-delà de laquelle l'hydrure (deutérure) devient un paramagnétique de Pauli

Multiscale mapping technique for the simultaneous estimation of absorption and partial scattering in optical coatings

The control and the characterization of optical losses are crucial elements in the design of high-quality thin films. Nonuniformity of losses and the existence of local defects have led us to perform simultaneous absorption and scattering mapping in exactly the same experimental conditions. An improved setup and new procedures are capable of providing such paired mappings of absorption and partial scattering at various spatial scales. The diameter of the pump beam, which governs lateral spatial resolution, can be chosen to be 3–100 ?m. The detectivity threshold can be as low as 0.1 part in 106 for absorption and 0.01 part in 106 for mapping partial scattering. Spatial windows can range from micrometer-sized areas for the study of micro defects to centimeter-sized areas on which the uniformity of losses can be checked. We study the spatial distribution of absorption and scattering losses under scale transformation by changing the spatial window while keeping the spatial resolution constant. We present one-dimensional and bidimensional multiscale studies. For example, we show that one can use multiscale mapping of defects to evaluate the qualities of substrate cleaning, which are not identical on micrometric and centimetric scales

Laser-induced damage in composites of scandium, hafnium, aluminum oxides with silicon oxide in the infrared

International audienc

Laser-induced Damage in scandium, hafnium, aluminum oxides composites with silica in the infrared

International audienc

ISPRS Hannover workshop

Urban growth is an ongoing trend and one of its direct consequences is the development of buried utility networks. Locating these networks is becoming a challenging task. While the labeling of large objects in aerial images is extensively studied in Geosciences, the localization of small objects (smaller than a building) is in counter part less studied and very challenging due to the variance of object colors, cluttered neighborhood, non-uniform background, shadows and aspect ratios. In this paper, we put forward a method for the automatic detection and localization of manhole covers in Very High Resolution (VHR) aerial and remotely sensed images using a Convolutional Neural Network (CNN). Compared to other detection/localization methods for small objects, the proposed approach is more comprehensive as the entire image is processed without prior segmentation. The first experiments using the Prades-Le-Lez and Gigean datasets show that our method is indeed effective as more than 49% of the ground truth database is detected with a precision of 75 %. New improvement possibilities are being explored such as using information on the shape of the detected objects and increasing the types of objects to be detected, thus enabling the extraction of more object specific features