Transport properties of mid-infrared colloidal quantum dot films

The transport and thermal properties of HgTe colloidal quantum dot films with cut-off wavelengths in the mid-IR are investigated. The cut-off wavelength of this material can be tuned over the 3-5 \mu m range, which makes it a promising alternative to existing high cost detectors. Post deposition processes such as ligand exchange and atomic layer deposition are investigated as a way to increase the carrier mobility.Comment: 7 pages, 7 figure

Specifications and Development of Interoperability Solution dedicated to Multiple Expertise Collaboration in a Design Framework

This paper describes the specifications of an interoperability platform based on the PPO (Product Process Organization) model developed by the French community IPPOP in the context of collaborative and innovative design. By using PPO model as a reference, this work aims to connect together heterogonous tools used by experts easing data and information exchanges. After underlining the growing needs of collaborative design process, this paper focuses on interoperability concept by describing current solutions and their limits. Then a solution based on the flexibility of the PPO model adapted to the philosophy of interoperability is proposed. To illustrate these concepts, several examples are more particularly described (robustness analysis, CAD and Product Lifecycle Management systems connections)

Enabled virtual and collaborative engineering coupling PLm system to a product data kernel

 Nowadays, the use of digital modelling through multiple CAx systems becomes more and more unquestionable. It allows many benefits (3D, automations, simulations, etc.) in spite of the fact that those different systems are individually used and are relatively isolated (i.e. not interoperable) during the product design process. Then more enhancement of product development might be possible if the whole design expertises (and IT applications), could collaborate dynamically (i.e. interoperate) in a complete virtual and collaborative engineering platform. For instance, product definition could be therefore seen as the synthesis of multidisciplinary information defined and assessed with respect to both collaborative activity and individual domain of expertise. At the same time, PDM/PLM systems are developed in most of cases as product data vault (product data referential of a company with internal PDM or projects collaborative referential with collaborative engineering platform). Nevertheless, current PLM are not able to manage more than only files (and not data breakdown) and then are not yet efficient for CAx systems interoperability. The paper aims at giving some first concepts and software demonstrators in order to tackle the problem of interoperability in virtual engineering design. The proposal is based on the PPO data kernel: a dynamic data structure able to integrate and merge multidisciplinary product data breakdown and to exchange them with other CAx applications. Then the current PDM/PLM systems will be defined as one of the CAx systems which interoperate with the kernel to benefit of both PLM and CAx potential functionalities. A business case will be studied between the PPO product data kernel and the Windchill (from PTC vendor) PLM system. Some recommendations for future work are then discussed to present what could be a generic interoperable software platform.

Synchrotron-based speciation of chromium in an Oxisol from New Caledonia: Importance of secondary Fe-oxyhydroxides

abstract In New Caledonia, the weathering of ultamafic rocks under a tropical climate has led to the residual accumulation of trace elements in lateritic soils widely dominated by Fe-oxyhydroxides. The speciation of trace elements, such as Cr, Ni, and Co, in these Oxisols remains a major subject of interest regarding mining and environmental issues. We have assessed the speciation of chromium in the upper part of an Oxisol, by combining bulk and spatially resolved chemical analyses (EPMA and SEM-EDS) with synchrotron-based spectroscopic data (EXAFS and XANES). EPMA indicates that the main hosts for chromium in the bedrock sample are the silicates forsterite, enstatite, and lizardite. Hosting of chromium in these easily weatherable mineral species could lead to a significant loss of this element upon weathering. However, total analyses of major elements indicate only a slight depletion of Cr, together with an immobility of Fe and Al and drastic losses of Si and Mg, after the weathering of the bedrock. Such a low mobility of chromium is likely related to its significant incorporation in goethite and hematite formed after the weathering of Fe 2+ -bearing primary silicates. This efficiency of secondary Fe-oxyhydroxides at immobilizing chromium is demonstrated by quantitative analysis of EXAFS data that indicates that these mineral species host between 67 and 75 wt% of total Cr (compared to the 18 to 22 wt% of total Cr hosted by chromite). In addition, SEM observation and SEM-EDS analyses performed on the Oxisol samples also show some evidence for chemical weathering of chromite. Chromite could then represent a past and/or present source of chromium upon extended tropical weathering of the studied Oxisol, rather than a stable host. These results emphasize the importance of secondary Fe-oxyhydroxides, compared to Cr-spinels, on chromium hosting in Oxisols developed upon tropical weathering of ultramafic rocks. Although the trapping mechanism of chromium mainly corresponds to incorporation within the structural network of goethite and hematite, sorption reactions at the surface of these mineral species could also be involved in such a process. In addition, considering their potential oxidative reactivity that can generate Cr 6+ or enhance the chemical weathering of chromite, the occurrence of Mn oxides could significantly modify the behavior of chromium upon weathering. These considerations indicate that further studies are needed to assess the actual potential of chromium release from Oxisols developed upon weathering of ultramafic rocks under a tropical climate

Optimisation et robustesse pour la prise de décision dans un contexte de conception intégrée et collaborative

La conception de produits est aujourd’hui une activité à la fois individuelle et collaborative. Une solution de modélisation pour le partage de l’information Produit-Processus-Organisation a été élaborée à travers le projet IPPOP. La solution conceptuelle et logicielle proposée repose sur un noyau de données commun auquel diverses applications expertes peuvent se connecter pour analyser les comportements du produit, du processus ou de l’organisation et de faire la synthèse (intégration) des nouvelles informations. Le papier présente les résultats concernant l’émergence progressive du produit fondée sur l’intégration d’expertise : le choix des composants technologiques. Chacune des expertises fait apparaître une proposition spécifique du produit (et sa géométrie associée) telle que peut la « voir » un expert. Ensuite, certaines techniques d’optimisation et d’analyse de la robustesse permettent d’analyser l’ensemble des variabilités de chacune des propositions de conception afin d’assister les acteurs dans la prise de décision

The Yin-Yang of the Green Fluorescent Protein:Impact on Saccharomyces cerevisiae stress resistance

International audienceAlthough fluorescent proteins are widely used as biomarkers (Yin), no study focuses on their influence on the microbial stress response. Here, the Green Fluorescent Protein (GFP) was fused to two proteins of interest in Saccharomyces cerevisiae. Pab1p and Sur7p, respectively involved in stress granules structure and in Can1 membrane domains. These were chosen since questions remain regarding the understanding of the behavior of S. cerevisiae facing different heat kinetics or oxidative stresses. The main results showed that Pab1p-GFP fluorescent mutant displayed a higher resistance than that of the wild type under a heat shock. Moreover, fluorescent mutants exposed to oxidative stresses displayed changes in the cultivability compared to the wild type strain. In silico approaches showed that the presence of the GFP did not influence the structure and so the functionality of the tagged proteins meaning that changes in yeast resistance were certainly related to GFP ROS-scavenging ability (Yang)

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements