59 research outputs found

    Fuzzy logic response to Young's modulus characterization of a flax-epoxy natural fiber composite

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    Most design approaches use the experimental elastic modulus as input variable to describe the material properties. In most cases the uncertainty and the variability of the modulus are neglected. In the worst case this can lead to bad estimations of the material performance and more iterations to the final solution. The purpose of this work is to reconcile the Young's modulus of three configurations ([0]10, [0]20 and [±45]10) of flax-epoxy composites obtained by different techniques including acoustic impulse, tensile and bending tests, according to ISO and ASTM standards. Results obtained with these techniques all show different levels of variability in Young's modulus values. A fuzzy logic model is used to obtain a simplified view of linguistic variables representing the modulus of elasticity and to reconcile different modules by including the uncertainty inherent to the different measuring techniques. Results have shown a strong potential for fuzzy logic to reconcile the disparity of Young modulus of natural fiber composites. © 2015 Elsevier Ltd

    Inhibition of Ubc13-mediated ubiquitination by GPS2 regulates multiple stages of B cell development

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    Non-proteolytic ubiquitin signaling mediated by Lys63 ubiquitin chains plays a critical role in multiple pathways that are key to the development and activation of immune cells. Our previous work indicates that GPS2 (G-protein Pathway Suppressor 2) is a multifunctional protein regulating TNF signaling and lipid metabolism in the adipose tissue through modulation of Lys63 ubiquitination events. However, the full extent of GPS2-mediated regulation of ubiquitination and the underlying molecular mechanisms are unknown. Here, we report that GPS2 is required for restricting the activation of TLR and BCR signaling pathways and the AKT/FOXO1 pathway in immune cells based on direct inhibition of Ubc13 enzymatic activity. Relevance of this regulatory strategy is confirmed in vivo by B cell-targeted deletion of GPS2, resulting in developmental defects at multiple stages of B cell differentiation. Together, these findings reveal that GPS2 genomic and non-genomic functions are critical for the development and cellular homeostasis of B cells

    On the influence of the exciton-blocking layer on the organic multilayer cells properties

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    The performances of organic photovoltaic cells based on the layer couple electron donor/electron acceptor (ED/EA) are significantly improved when an exciton blocking layer (EBL) is inserted between the organic acceptor and the cathode. A new material, the (Z)-5-(4-chlorobenzylidene)-3-(2-ethoxyphenyl)-2-thioxothiazolidin-4-one, that we called (CBBTZ), has been synthesized, characterized and probed as EBL. The energy levels corresponding to the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the CBBTZ have been determined from the first oxidation and reduction potential respectively, using cyclic voltametric (CV) measurements. From CV curves, CBBTZ in dichloromethane showed a one electron reversible reduction and oxidation waves. The values of its HOMO and LUMO have been estimated to be 6.42 eV and 3.42 eV respectively. Such values show that CBBTZ could be probed as EBL in organic solar cells based on the ED/EA couple copper phthalocyanine(CuPc)/fullerene (C60). The photovoltaic solar cells have been obtained by sequential deposition under vacuum of the different films. The different thin film thicknesses were measured in situ by a quartz monitor. Multilayer solar cells ITO/Au/CuPc/C60/EBL/Al have been probed, where EBL is the aluminium tris(8-hydroxyquinoline) (Alq3), the CBBTZ, the 2-(4-byphenylyl)-5-(4-tert-buthylphenyl)-1,3,4-oxadiazole (butyl PBD) or the bathocuproine (BCP). The optimum film thickness is 8–9 nm whatever the EBL used. When obtained in the same run, the averaged efficiency of the cells using the CBBTZ is of the same order of magnitude than that obtained with BCP and higher than that achieved with Alq3 or butyl PBD. It is shown by XPS study that some aluminium of the cathode is present in the buffer layer. This aluminium could justify the ability of the electrons to cross the insulating exciton blocking layer thick of 9 nm

    Étude théorique et expérimentale du transfert du dioctyl phtalate à partir d'un disque de PVC plastifié plongé dans une huile comestible

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    La mise en contact polymère-liquide se traduit généralement par des échanges de matière entre les 2 milieux considérés, ce qui constitue un inconvénient majeur lorsque le liquide est un aliment ou le sang. Cependant, ces transferts de matière dans les polymères peuvent apparaître comme très intéressants sur le plan industriel, si l'on est capable de les utiliser et de les contrôler. Il est donc nécessaire d'avoir une bonne connaissance de ces processus de transfert qui sont contrôlés par diffusion. Nous avons étudié la migration du dioctyl phtalate (DOP) dans une huile comestible en nous plaçant dans les conditions les plus défavorables : taux de plastification (50 % en poids) et température (30 °C) élevés. L'analyse quantitative du DOP dans un milieu liquide aussi complexe et dans le PVC lui- même a été facilitée par l'utilisation de la technique des traceurs radioactifs. Un modèle mathématique simplifié en négligeant le transport de l'huile dans la masse de PVC a été testé. Ce modèle basé sur la recherche d'une solution aux différence finies explicite permet au seuil de 0,1 % de reproduire pour le DOP, les profils de concentration dans le polymère et les cinétiques de transfert dans l'huile

    A DCT-based algorithm for multi-channel near-lossless EEG compression

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    Acaricidal activity of flavonoids extract of Borago officinalis L. (Boraginaceae) against brown dog tick, Rhipicephalus sanguineus (Latreille, 1806)

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    International audienceBorago officinalis L. (Boraginaceae) is a plant of the Boraginaceae family, used in Algeria for food and medicinal purposes. This study reports the effect of flavonoids extracted from the aerial part of Borago officinalis L. (Boraginaceae) on the larvae and engorged adult females of the brown dog tick Rhipicephalus sanguineus (Latreille, 1806) using adults immersion test (AIT) and larval immersion test (LIT). For this purpose, the larvae and engorged female of Rhipicephalus sanguineus (Latreille, 1806) were exposed to serial dilutions of flavonoids extract (50 mg/ml, 25 mg/ml, 12.5 mg/ml and 6.25 mg/ml) using ``dipping method'' in vitro. The plant extract was obtained by fractionation using appropriate solvents. The extraction yield is 22% with a flavonoids concentration equal to 129.12 mu g equivalent of quercetin/ml of the extract. The chromatographic analysis by high performance thin layer chromatography (HPTLC) reveals the presence of gallic acid, vanillic acid, kaempferol, dihydroxybenzoic and quercetin. The results obtained show that the flavonoids extract of Borago officunalis L. (Boraginaceae) considerably reduces the oviposition and the hatching rate of the eggs of Rhipicephalus sanguineus (Latreille, 1806) and was shown to be toxic against newly hatched larvae of Rhipicephalus sanguineus (Latreille, 1806) (P < 0.05)

    Acaricidal activity of flavonoids extract of Borago officinalis L. (Boraginaceae) against brown dog tick, Rhipicephalus sanguineus (Latreille, 1806)

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    International audienceBorago officinalis L. (Boraginaceae) is a plant of the Boraginaceae family, used in Algeria for food and medicinal purposes. This study reports the effect of flavonoids extracted from the aerial part of Borago officinalis L. (Boraginaceae) on the larvae and engorged adult females of the brown dog tick Rhipicephalus sanguineus (Latreille, 1806) using adults immersion test (AIT) and larval immersion test (LIT). For this purpose, the larvae and engorged female of Rhipicephalus sanguineus (Latreille, 1806) were exposed to serial dilutions of flavonoids extract (50 mg/ml, 25 mg/ml, 12.5 mg/ml and 6.25 mg/ml) using ``dipping method'' in vitro. The plant extract was obtained by fractionation using appropriate solvents. The extraction yield is 22% with a flavonoids concentration equal to 129.12 mu g equivalent of quercetin/ml of the extract. The chromatographic analysis by high performance thin layer chromatography (HPTLC) reveals the presence of gallic acid, vanillic acid, kaempferol, dihydroxybenzoic and quercetin. The results obtained show that the flavonoids extract of Borago officunalis L. (Boraginaceae) considerably reduces the oviposition and the hatching rate of the eggs of Rhipicephalus sanguineus (Latreille, 1806) and was shown to be toxic against newly hatched larvae of Rhipicephalus sanguineus (Latreille, 1806) (P < 0.05)
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