Original Conductive Nano-Co3O4 Investigated as Electrode Material for Hybrid Supercapacitors

Cobalt oxides have been extensively used as conductive additives for Ni-MH batteries. We report in this paper the performances of an original nanometric cobalt oxide, close to Co3O4, as electrode material for hybrid supercapacitors. This spinel type phase contains hydrogen, lithium, cobalt vacancies, and especially Co4þ ions within the structure, leading to a high electronic conductivity. Cyclic voltammetry and impedance spectroscopy measurements show interesting capacitance (320 F/g in 8M-KOH), as well as good electrochemical cycling with a small amount of carbon black (5%)

Sodium electrochemical deintercalation and intercalation in O3-NaRhO2 and P2-NaxRhO2 layered oxides

International audienceSodium transition metal layered oxides are a class of materials which exhibits fascinating properties, such as high thermoelectric power. Whereas most of the work conducted so far focused on 3d transition metals, mainly cobalt, compounds with 4d metals could be excellent materials to obtain new strongly correlated electron systems. This work is focused on NaxRhO2 compounds, with O3- and P2-type structures. The P2-type structure was obtained by ion exchange from the potassium phase P2-K0.62RhO2. This type of synthesis was conducted here for the first time on layered oxides with 4d transition metals. The phase diagram of both structures was explored by sodium electrochemical deintercalation/intercalation in a battery. The existence of single phases was shown with presumably different physical properties. As an example, the O′3-Na1/2RhO2 compound electrochemically obtained for the first time exhibits a metallic behavior, whereas the O3-NaRhO2 phase is a semiconductor. The synthesis of each single phase existing in both the O3- and P2-type systems should lead to new insights into the structure-properties relationships of this class of materials

Autour du « manque » en anglais

Cette étude tente de rendre compte du fonctionnement de deux verbes anglais « lack » et « want ». Plus précisément, elle se fixe deux buts. Tout d’abord, proposer pour chacun des verbes une valeur prototypique, à partir de laquelle d’autres valeurs sont dérivées, ensuite, montrer comment le sémantisme de ces verbes implique des arguments et comment ces derniers s’organisent sur le linéaire.This is an attempt to explain how the two verbs “lack” and “want” are used in English. Our first goal is to propose a prototypical meaning, from which various semantic values or sense effects can be derived. Our second goal is to show in what way the relation between the semantic content of these verbs and the context can facilitate the understanding of the different syntactic positions assigned to various arguments in the predicative relation

Autour du « manque » en anglais

Cette étude tente de rendre compte du fonctionnement de deux verbes anglais « lack » et « want ». Plus précisément, elle se fixe deux buts. Tout d’abord, proposer pour chacun des verbes une valeur prototypique, à partir de laquelle d’autres valeurs sont dérivées, ensuite, montrer comment le sémantisme de ces verbes implique des arguments et comment ces derniers s’organisent sur le linéaire.This is an attempt to explain how the two verbs “lack” and “want” are used in English. Our first goal is to propose a prototypical meaning, from which various semantic values or sense effects can be derived. Our second goal is to show in what way the relation between the semantic content of these verbs and the context can facilitate the understanding of the different syntactic positions assigned to various arguments in the predicative relation

Antibrouillage radar en contexte de rotation d'antenne

- Nous nous intéressons dans cet article à l'algorithme Opposition dans les Lobes Secondaires (OLS) utilisé en traitement d'antenne RADAR dans un but d'antibrouillage en contexte de rotation d'antenne. Nous montrons que l'utilisation de la méthode Extended Sample Matrix Inversion (ESMI) [2] conduit alors à des performances supérieures à la méthode standard

High power density aqueous hybrid supercapacitor combining activated carbon and highly conductive spinel cobalt oxide

The remarkable electrochemical behavior of complete activated carbon/cobalt oxide cells is reported in the present work. Among the various weight ratios between the positive and negative electrodes evaluated, the best features are obtained with an overcapacitive cobalt oxide electrode. The energy densities obtained by this system (20 Wh kg−1 for a power density of 209 W kg−1) are twice higher than those measured for a activated carbon/activated carbon symmetric cell, in the same operating conditions. With discharge capacities around 62 F g−1, this system is among the best ones reported in the literature for this category

Pkd2l1 is required for mechanoception in cerebrospinal fluid-contacting neurons and maintenance of spine curvature

Defects in cerebrospinal fluid (CSF) flow may contribute to idiopathic scoliosis. However, the mechanisms underlying detection of CSF flow in the central canal of the spinal cord are unknown. Here we demonstrate that CSF flows bidirectionally along the antero-posterior axis in the central canal of zebrafish embryos. In the cfap298tm304 mutant, reduction of cilia motility slows transport posteriorly down the central canal and abolishes spontaneous activity of CSF-contacting neurons (CSF-cNs). Loss of the sensory Pkd2l1 channel nearly abolishes CSF-cN calcium activity and single channel opening. Recording from isolated CSFcNs in vitro, we show that CSF-cNs are mechanosensory and require Pkd2l1 to respond to pressure. Additionally, adult pkd2l1 mutant zebrafish develop an exaggerated spine curvature, reminiscent of kyphosis in humans. These results indicate that CSF-cNs are mechanosensory cells whose Pkd2l1-driven spontaneous activity reflects CSF flow in vivo. Furthermore, Pkd2l1 in CSF-cNs contributes to maintenance of natural curvature of the spine

A comparison of national approaches to setting ecological status boundaries in phytobenthos assessment for the European Water Framework Directive: results of an intercalibration exercise

The European Union (EU)'s Water Framework Directive (WFD) requires that all Member States participate in intercalibration exercises in order to ensure that ecological status concepts and assessment levels are consistent across the EU. This paper describes one such exercise, performed by the countries in the Central/Baltic Geographical Intercalibration Group stretching from Ireland in the west to Estonia in the east and from the southern parts of Scandinavia to the northern regions of Spain and Italy (but excluding alpine regions, which were intercalibrated separately). In this exercise, methods used to measure ecological status of rivers using benthic diatoms were compared. Ecological status is estimated as the ratio between the observed value of a biological element and the value expected in the absence of significant human impact. Approaches to defining the 'reference sites', from which these 'expected' values were derived, varied from country to country. Minimum criteria were established as part of the exercise but there was still considerable variation between national reference values, reflecting typological differences that could not be resolved during the exercise. A simple multimetric index was developed to compare boundary values using two widely used diatom metrics. Boundary values for high/good status and good/moderate status set by each participant were converted to their equivalent values of this intercalibration metric using linear regression. Variation of ±0.05 EQR units around the median value was considered to be acceptable and the exercise provided a means for those Member States who fell significantly above or below this line to review their approaches and, if necessary, adjust their boundaries

The SLOOP project: Simulations, Parallel Object-Oriented Languages, Interconnection Networks

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