Investigation of Kelvin probe force microscopy efficiency for the detection of hydrogen ingress by cathodic charging in an aluminium alloy

Detecting and locating absorbed hydrogen in aluminium alloys is necessary for evaluating the contribution of hydrogen embrittlement to the degradation of the mechanical properties for corroded or cathodically hydrogen-charged samples. The capability of Kelvin probe force microscopy (KFM) to overcome this issue was demonstrated. Aluminium alloy samples were hydrogenated by cathodic polarisation in molten salts (KHSO4/NaHSO4.H2O). The presence of absorbed hydrogen was revealed; the affected zone depth was measured by secondary ion mass spectroscopy (SIMS) analyses and KFM measurements

Combined Kelvin probe force microscopy and secondary ion mass spectrometry for hydrogen detection in corroded 2024 aluminium alloy

The capability of Kelvin probe force microscopy (KFM) to detect and locate hydrogen in corroded 2024 aluminium alloy was demonstrated. Hydrogen was introduced inside the 2024 alloy following a cyclic corrosion test consisting of cycles of immersion in 1 M NaCl solution followed by exposure to air at -20 °C. The combination of scanning electron microscopy, secondary ion mass spectrometry and KFM demonstrated that the grain and subgrain boundaries were preferential pathways for the short-circuit diffusion of hydrogen but also acted as a source of hydrogen diffusion in the lattice over distances of up to ten microns with non-negligible desorption when exposed to air at room temperature for 24 h

RAPPORT FINAL OPENRJ

Le Projet OpeNRJ a développé une plateforme de données ouvertes autour del’énergétique des bâtiments. Elle engage une communauté d'organisations tertiaires àmettre à disposition de façon libre et ouverte les consommations énergétiques de leursbâtiments. Ces données sont facilement téléchargeables et sont gratuites, accessibles surwww.openrj.eu.Ce document constitue le rapport final du projet : il précise le contexte (Chapitre 2) qui aconduit à la genèse du projet, rappelle ses objectifs (Chapitre 3), puis présente demanière synthétique les principaux résultats (Chapitre 4). Ce rapport proposeégalement un résumé des autres livrables (Chapitre 5) produits dans le cadre du projetpour les lecteurs intéressés par des conclusions plus détaillées, un rapport dedissémination (Chapitre 6), ainsi qu’un bilan global (Chapitre 7), qui présente égalementles perspectives après la clôture du pro

The XENON100 exclusion limit without considering Leff as a nuisance parameter

In 2011, the XENON100 experiment has set unprecedented constraints on dark matter-nucleon interactions, excluding dark matter candidates with masses down to 6 GeV if the corresponding cross section is larger than 10^{-39} cm^2. The dependence of the exclusion limit in terms of the scintillation efficiency (Leff) has been debated at length. To overcome possible criticisms XENON100 performed an analysis in which Leff was considered as a nuisance parameter and its uncertainties were profiled out by using a Gaussian likelihood in which the mean value corresponds to the best fit Leff value smoothly extrapolated to zero below 3 keVnr. Although such a method seems fairly robust, it does not account for more extreme types of extrapolation nor does it enable to anticipate on how much the exclusion limit would vary if new data were to support a flat behaviour for Leff below 3 keVnr, for example. Yet, such a question is crucial for light dark matter models which are close to the published XENON100 limit. To answer this issue, we use a maximum Likelihood ratio analysis, as done by the XENON100 collaboration, but do not consider Leff as a nuisance parameter. Instead, Leff is obtained directly from the fits to the data. This enables us to define frequentist confidence intervals by marginalising over Leff.Comment: 10 pages;, 9 figures; references adde

Narrativités 2.0 : fragmentation-organisation d’un métadiscours

Fans’ analysis of their creative practices and of writing generally, academics’ capture of this narrative and discursive material represent a heterogeneous collection of meta-discourses. How is this circulation of « meta » narratives and discourses expressing a reflexive thinking about writing? We focus on a discursive spread as a fragmentation-organization process, which does not bring into conflict fans and academics’ metanarratives and metadiscourses, but apprehends a binding dichotomy or a co-extensive principle (Masoni Lacroix & Cailler, 2016), which expose this multiplicity. We stress on an emancipating-(re)normalizing movement of writing, named met@ttachment, as a constitutive principle of fannish narrativities, having an effect on scientific writing.Le retour des fans sur leurs propres pratiques créatives et sur l’écriture en général, la manière dont les universitaires se saisissent de ce matériel narratif et discursif représentent une collection de métadiscours hétérogènes. En quel sens cette circulation de métarécits et de métadiscours exprime-t-elle une pensée réflexive sur l’écriture ? Nous avançons une distribution argumentative en tant que processus de fragmentation-organisation, qui n’oppose plus les métarécits et les métadiscours fans et académiques, mais saisit une dichotomie liante, un principe de co-extensivité (Masoni Lacroix & Cailler, 2016), qui rend visible cette multiplicité. Nous soulignons alors un mouvement d’émancipation-(re)normalisation de l’écriture, nommé mét@ttachement, comme principe constitutif des narrativités faniques, ayant un effet sur l’écriture scientifique

La surdétermination du politique, un projet de légima(c)tion théorique des cultural studies

Dans « Cultural Studies and its Theoretical Legacies », Stuart Hall (1992) prend position par rapport au grand récit des cultural studies, afin d’interroger leur projet ainsi que le problème en tension du travail théorique, qu’il développe en pratique politique. Il convie à une pratique dialogique et conflictuelle de lecture, qui a toujours guidé son approche et sa lutte envers les textes, ainsi que son combat contre le marxisme et sa mésinterprétation. Nous engagerons une lecture dialogique de la contribution d’Éric Maigret (2013) en interrogeant ce qu’il qualifie de systématisation théorique de Stuart Hall, pour nous attacher à déceler le décentrement métaphorique de ces méta-objets de discours que sont la justification scientifique du positionnement disciplinaire et la surdétermination structurelle du politique.In “Cultural Studies and its theoretical legacies”, a text written with an autobiographic voice, Stuart Hall (1992) takes a stand in relation to the grand narrative of Cultural Studies, so as to question its project and, in so doing, to question the problem and the tension of a theoretical work, that has to develop into a political practice. Stuart Hall invites us to engage in a dialogical reading process through which we can read and struggle with texts. He struggles with marxism and its misreadings. In this article, we intend to undertake a dialogical reading of Éric Maigret’s text. Can we talk about a theoretical systematization in Stuart Hall’s thinking or should we better find a narrative way of using metaphors, decentring discursive objects such as the scientific legitimacy of disciplinarity or the structural overdetermination of politics

Principes coextensifs de la fiction sérielle, de la distribution diffusée à une pratique interprétative dialogique : une nouvelle donne socio-narrative ?

Ce texte explore les déclinaisons télévisuelles et web de l’écriture sérielle. Nous y dépassons le clivage entre instance de production et instance de réception, afin d’envisager le croisement de logiques industrielles et narratives, vers la dimension dialogique de la co-construction de récits, d’identités et de sens. Notre analyse croise une approche socioéconomique des industries culturelles à une approche socio-narrative de la production de fictions et de contenus narratifs vers et par des publics. Les pratiques médiatisées de lecture et d’écriture mettent en tension les principes de production et de (re)création sérielle et donnent du sens aux usages de l’interactivité. La transmédialité nous semble le lieu où peuvent être saisies la concurrence et la complémentarité du procédé de l’itération ou de la formule sérielle et de la transformation narrative.This text aims at exploring television and web forms of serial writing. The dichotomy between production and reception will be overtaken in the crossing of industrial and narrative logics to the dialogical dimension underlying the co-construction of stories, identities and meaning. Our analysis is built upon a socioeconomic approach of cultural industries and a socio-narrative approach of fiction stories and narrative contents production made for and by the audience. On-line reading and writing practices question production and serial (re)creation principles and bring a sense to interactivity uses. Transmediality appears to be the place where concurrency and complementarity of iteration process or serial formula and narrative transformation can be understood

Unique probe of dark matter in the core of M87 with the Event Horizon Telescope

We demonstrate the unprecedented capabilities of the Event Horizon Telescope (EHT) to image the innermost dark matter profile in the vicinity of the supermassive black hole at the center of the M87 radio galaxy. We present the first model of the synchrotron emission induced by dark matter annihilations from a spiky profile in the close vicinity of a supermassive black hole, accounting for strong gravitational lensing effects. Our results show that the EHT should readily resolve dark matter spikes if present. Moreover, the photon ring surrounding the silhouette of the black hole is clearly visible in the spike emission, which introduces observable small-scale structure into the signal. We find that the dark matter-induced emission provides an adequate fit to the existing EHT data, implying that in addition to the jet, a dark matter spike may account for a sizable portion of the millimeter emission from the innermost (subparsec) region of M87. Regardless, our results show that the EHT can probe very weakly annihilating dark matter. Current EHT observations already constrain very small cross sections, typically down to a few 10−31 cm3 s−1 for a 10 GeV candidate, close to characteristic values for p-wave-suppressed annihilation. Future EHT observations will further improve constraints on the DM scenario

Par2 Inactivation Inhibits Early Production of TSLP, but Not Cutaneous Inflammation, in Netherton Syndrome Adult Mouse Model

Netherton syndrome (NS) is a severe genodermatosis characterized by abnormal scaling and constant atopic manifestations. NS is caused by mutations in SPINK5 (Serine Protease INhibitor Kazal-type 5), which encodes LEKTI (LymphoEpithelial Kazal Type-related Inhibitor). Lack of LEKTI causes stratum corneum detachment secondary to epidermal proteases hyperactivity. Whereas a skin barrier defect is generally regarded as a major cause for atopy, we previously identified a cell-autonomous signaling cascade that triggers pro-Th2 cytokine thymic stromal lymphopoietin (TSLP) production in LEKTI-deficient epidermis. This signaling is initiated by unrestricted kallikrein 5 (KLK5) activity, which directly activates proteinase-activated receptor 2 (PAR2)-mediated expression of TSLP and favors a cutaneous proallergic microenvironment independently of the environment and of the adaptive immune system. To further confirm these results in vivo, we generated Spink5/Par2 double knockout (DKO) mice. At embryonic day 19.5, these mice display a dramatic decrease in TSLP expression, although stratum corneum detachment persists, confirming the role of the KLK5–PAR2 cascade in TSLP-mediated early proallergic signaling. However, deletion of Par2 in adult DKO-grafted skin does not rescue the inflammatory phenotype probably resulting from stratum corneum detachment. We conclude that several mechanisms trigger and maintain the inflammatory phenotype in NS. These include skin barrier impairment, mechanical stress secondary to stratum corneum detachment, as well as protease-induced proinflammatory and proallergic pathways, including PAR2-mediated overexpression of TSLP