Search results for " light"
showing 10 items of 1141 documents
Interfacial Modification for High-Efficiency Vapor-Phase-Deposited Perovskite Solar Cells Based on a Metal Oxide Buffer Layer.
2018
Vacuum deposition is one of the most technologically relevant techniques for the fabrication of perovskite solar cells. The most efficient vacuum-based devices rely on doped organic contacts, compromising the long-term stability of the system. Here, we introduce an inorganic electron-transporting material to obtain power conversion efficiencies matching the best performing vacuum-deposited devices, with open-circuit potential close to the thermodynamic limit. We analyze the leakage current reduction and the interfacial recombination improvement upon use of a thin (<10 nm) interlayer of C60, as well as a more favorable band alignment after a bias/ultraviolet light activation process. This wo…
Early stages of beta2-microglobulin aggregation and the inhibiting action of alphaB-crystallin
2008
The interest of nucleation of protein crystals and aggregates (including oligomerization) spans from basic physics theory all the way to biophysics, nanophysics, clinical sciences, biotechnologies, food technologies and polymer-solvent interactions. Understanding nucleation within a theoretical framework capable of providing quantitative predictions and control of nucleation rates, or even the very occurrence of crystallization, is a long-sought goal of remarkable relevance to each of the above fields. A large amount of work has been aimed at such goal, but success has been so far rather limited. Work at our laboratory has more recently highlighted a direct link between nucleation rates and…
Flash synthesis of zirconia nanoparticles by microwave forced hydrolysis
2001
Forced hydrolysis preparation of zirconia sols and powders by microwave heating of zirconium tetrachloride solutions at temperatures equal to 180 °C leads in a few minutes to monodispersed nanoscale zirconia particles. Synthesis was performed in a microwave reactor called the RAMO system. This microwave reactor was designed by the authors. This flash-synthesis process combines the advantages of forced hydrolysis (homogeneous precipitation) and microwave heating (very fast heating rates). The sols and powders were characterized by x-ray diffraction,photon correlation spectroscopy (PCS), small-angle x-ray scattering, and transmission electron microscopy. Sols are colloidally stable, which mea…
Approche coopérative pour l'acquisition et l'observation de formes tridimensionnelles
2009
Technologic progres can reduce the barrier between real image and virtual image so far it is really difficult to recognize them. When virtual reality is well done, augmented reality, from virtual world to real world, is still developped. We want to project a virtual texture onto a 3D real object. By using cameras and projector, we estimate its real pose in the virtual reference by projecting a coded pattern to find points of correspondence between cameras and projector onto the textureless object, where common detector of points of correspondence are useless. We combine the calibration of the system and these points to estimate the 3D position of the object, and then register with a fine mo…
Multiple Structured Light-Based Depth Sensors for Human Motion Analysis: A Review
2012
Human motion analysis is an increasingly important active research domain with various applications in surveillance, human-machine interaction and human posture analysis. The recent developments in depth sensor technology, especially with the release of the Kinect device, have attracted significant attention to the question of how to take advantage of this technology in order to achieve accurate motion tracking and action detection in marker-less approaches. In this paper, we review the benefits and limitations deriving from the adoption of structured light-based depth sensors in human motion analysis applications. Surveying the relevant literature, we have identified in calibration, interf…
Measurement of the Depth of Maximum of Extensive Air Showers above 10(18) eV
2010
We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10¹⁸ eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106⁺³⁵₋₂₁) g/cm²/decade below 1018.24 ± 0.05 eV and (24 ± 3) g/cm²/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm². The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.
Translucent medium
2013
8 pages; article in McGraw-Hill Science & Technology Encyclopedia; International audience; A medium allowing light to pass through partially or diffusely. An object cannot be seen clearly through translucent matter. In the most accepted meaning, translucency is used to describe a medium transmitting most of the light but scattering it more or less so that objects seen through it are blurry with soft contours and without details. The closer the object is to the medium the sharper its image through it. There are many examples of such media among natural or manufactured artifacts, including wax paper, milky water, colloidal and hydrogel materials, aerogels, smoke, fog, clouds, optical ceramics…
Projet CHIROLUM. Comment limiter les impacts écologiques de l’éclairage artificiel nocturne le long des ILTe ? Caractérisation de l’influence des par…
2021
Ce rapport expose les résultats du projet Chirolum ayant pour objectif d'identifier des pistes de réduction des impacts écologiques de l'éclairage artificiel le long des infrastructures de transport. En prenant l'exemple de sites d'études le long de lisières forestières aux Pays-Bas et le long du Canal du Midi à Toulouse, les résultats montrent que la lumière perturbe fortement l'usage de ces continuités écologiques et infrastructures de transport par les chauves-souris, engendrant des modifications dans le comportement de vol et potentiellement des coûts énergétiques supplémentaires, ainsi qu'une diminution de la connectivité fonctionnelle pour ces espèces potentiellement préjudiciables à …
Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector
2010
The ANTARES high energy neutrino telescope is a three-dimensional array of about 900 photomultipliers distributed over 12 mooring lines installed in the Mediterranean Sea. Between February and November 2007 it acquired data in a 5-line configuration. The zenith angular distribution of the atmospheric muon flux and the associated depth-intensity relation are measured and compared with previous measurements and Monte Carlo expectations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is presented.
Programme-cadre FENOIR (Figurations de l’environnement nocturne des territoires réunionnais). Rapport d’étape pour le Parc national de La Réunion
2022
Soumise à une importante poussée démographique, l’île de La Réunion a vu sa population urbaine fortement augmenter – passant de 44 % de la population totale en 1975 à 95 % en 2015. Directement corrélée aux formes et dynamiques spatiales de l’urbanisation, l’empreinte lumineuse sur l’île a connu une mutation radicale ces dernières années : son emprise et sa pression ont considérablement augmenté sur l’ensemble du territoire, depuis la côte jusqu’à l’intérieur même du Parc national de La Réunion qui recouvre plus de 76 % du territoire insulaire (42 % pour la zone cœur). Acteur incontournable des enjeux environnementaux sur l’île, le Parc national a mené très tôt des actions autour des effets …