Metal halide perovskites for energy applications

Exploring prospective materials for energy production and storage is one of the biggest challenges of this century. Solar energy is one of the most important renewable energy resources, due to its wide availability and low environmental impact. Metal halide perovskites have emerged as a class of semiconductor materials with unique properties, including tunable bandgap, high absorption coefficient, broad absorption spectrum, high charge carrier mobility and long charge diffusion lengths, which enable a broad range of photovoltaic and optoelectronic applications. Since the first embodiment of perovskite solar cells showing a power conversion efficiency of 3.8%, the device performance has been boosted up to a certified 22.1% within a few years. In this Perspective, we discuss differing forms of perovskite materials produced via various deposition procedures. We focus on their energy-related applications and discuss current challenges and possible solutions, with the aim of stimulating potential new applications

Raman micro-spectroscopy can be used to investigate the developmental stage of the mouse oocyte

In recent years, the uptake of assisted reproductive techniques such as in vitro fertilisation has risen exponentially. However, there is much that is still not fully understood about the biochemical modifications that take place during the development and maturation of the oocyte. As such, it is essential to further the understanding of how oocyte manipulation during these procedures ultimately affects its developmental potential; yet, there are few methods currently available which are capable of providing a quantitative measure of oocyte quality. Raman spectroscopy enables investigation of the global biochemical profile of intact cells without the need for labelling. Here, Raman spectra were acquired from the ooplasm of mouse oocytes at various stages of development, from late pre-antral follicles, collected after in vitro maturation within their ovarian follicles and from unstimulated and stimulated ovulatory cycles. Using a combination of univariate and multivariate statistical methods, it was found that ooplasm lipid content could be used to discriminate between different stages of oocyte development. Furthermore, the spectral profiles of mature oocytes revealed that oocytes which have developed in vitro are protein-deficient when compared to in vivo grown oocytes. Finally, the ratio of two Raman peak intensities, namely 1605:1447 cm21, used as a proxy for the protein-to-lipid ratio of the ooplasm, was shown to be indicative of the oocyte’s quality. Together, results indicate that Raman spectroscopy may present an alternative analytical tool fo

CHRONIQUES D'UN VETERINAIRE RURAL AU COURS DU XXEME SIECLE DANS LE CANTAL

Le XXième siècle a été un siècle de grandes mutations ; les vétérinaires ruraux ne pouvaient y échapper. Au sein du département du Cantal, cher à notre coeur, nous avons choisi de décrire l'histoire de ces hommes mais aussi ce qui a fait leurs joies et leurs labeurs quotidiens. Pour cela, nous avons contacté, à partir des annuaires Roy de ces vingt dernières années, les vétérinaires retraités et actifs du département. Puis nous sommes allés à leur rencontre au cours d'entretiens personnels. Nous avons ainsi pu décrire leur cadre de vie et ses contraintes, les évolutions sociales et techniques ressenties au cours du siècle pour enfin ébaucher l'avenir de la rurale.MAISONS-ALFORT-Ecole Vétérin (940462302) / SudocSudocFranceF

Système de codage de canal hièrarchique pour la télévision numérique

Les avantages de l'approche hiérarchique en matière de diffusion numérique de télévision poussent à étudier des systèmes de codage de canal offrant au moins deux niveaux de protection vis-à-vis du bruit. Cet article présente une méthode de codage de canal hiérarchique; bien qu'inspirée des constellations multirésolution, cette méthode utilise les propriétés du décodage sur décisions douces pour obtenir un bien meilleur compromis entre la robustesse de l'information haute priorité et l'inévitable fragilité de l'information basse priorité qui en découle

Etude par coupes a basse temperature de l'espace cranio-pharyngo-mandibulaire. [A study of the cranio-pharyngo-mandibular space by sections at low temperature]

After acrylic injections into the vessels and mandibular block anaesthesia the pterygo-mandibular space is studied in 38 anatomical pieces. 538 colour slides have been obtained from anatomical cuts at low temperature with the scannigraph system. The results point out that a cranio-pharyngo-mandibular space is clearly distinguished laterally, from a medial maxillo-pharyngeal space. There is no transversal communication between them. On the contrary, the cranio-pharyngo-mandibular space communicates, forward and upward, with the temporal space; forward and downward, with the sub-mandibular space. The cranio-pharyngo-mandibular space contains an interpterygoid space communicating with the oval foramen by a "chimney" largely filled by the emissary pterygoid veins. A pericondilar plexus of veins is also observed. The cranio-pharyngo-mandibular space is characterised by the cellulo-adipose tissue by which it is filled and which guides the diffusion of injected solutions to the oval foramen

Phase Diagrams for Systems with Low Free Energy Variation: A Coupled Theory/Experiments Method Applied to Li-Graphite

The paper presents a fast and efficient method to compute phase diagrams using first-principles methods and statistical physics coupled with experimental techniques. The method is applied to lithium intercalated graphite for which evidence of experimental anomalies have recently questioned the currently accepted stage II/stage I two-phase transformation in the 0.5 ≤ x ≤ 1.0 composition range. Our coupled experimental and theoretical analysis has led to a full determination of the Li_xC_6 phase diagram in this range of composition, revealing previously unknown phase transitions and the characterization of at least two new phases

A tridimensional study using cuts at a low temperature of the infratemporal region

Although the infratemporal region is well defined anatomically, its complex topography has been the subject of numerous, and sometimes, opposite works. That is the reason why it appeared necessary for the authors to re-evaluate this topic using the original method of Combelles and Boyer, allowing to define three referential planes, and thereby, a tridimensional shape and the volume of this region. This study allows to conclude that the infratemporal region is a triangular prism with an horizontal main axis 47 mm long. Its anterior base has a mean area of 733 mm2. The posterior top consists of the Juvara slot and has a mean area of 490 mm2. This infratemporal prism contains another one, the pterygomandibular space, prismatic too. It widens out from coronoid plane (93 mm2) to mandibular foramen plane (169 mm2) before ending as a narrow groove between the neck of the mandibular condyle and the interpterygoid fascia. The volume of the pterygomandibular space is quite superior to the value usually reported in the dental literature. It is of 4.8 ml to 5.8 ml according to denture. These results point out the opportunity to accomodate more important volumes of anesthesic solutions, than the 1.8 ml usually performed, without any leak out of the infratemporal region