Development of nickel phosphorus coatings containing micro particles of talc phyllosilicates

The present work aims to characterized nickel phosphorus coatings co-deposited with talc particles on steel. The NiP-talc composite deposits were developed to serve as hard coatings with a lubricating effect at 600 C. This process, which is free of hexavalent chromium, could provide a reliable substitute for the electrodeposition of hard chromium coating used in industrial applications. Local responses to static and dynamic mechanical loading have been obtained by nano- and microhardness, microtensile and nanoscratch testing. The hardness and stiffness values slightly decrease when the amount of talc increases for untreated coatings. In contrast, a 420 C heat treatment leads to high hardness and Young’s modulus values due to crystallization. Moreover, a 600 C heat treatment lowers these values through overageing. A 420 C heat treatment greatly improves the adherence and the cohesion of the coatings containing talc

Structure, morphology and mechanical properties of electrodeposited composite coatings Ni–P/SiC

Physical properties of the NiP/SiC deposits are discussed according to the electroplating parameters and heat treatments. The insertion of silicon carbide in the coatings does not modify their rigidity (E = 230 GPa), increases their hardness slightly (50 Vickers) and decreases the residual stresses in the coatings. The phosphorus content has a major effect on the structure and the physical properties. Indeed, the insertion of phosphorus into the deposits generates a grain size reduction or even an amorphisation which results in morphological modifications observed by AFM. In parallel a very important hardening is associated with incorporation of phosphorus: hardness is multiplied by 3 to reach 600 HV0.1. The deposits tend to become crystalline following the heat treatments. With 420 °C, the precipitation of a Ni3P phase which distorts the crystal lattice is observed, increasing the hardness of the deposits

Understanding emergence in business model development: how companies interact with stakeholders to deal with environmental ambiguity

Cette recherche explore le caractère émergent du développement d’un business model en adoptant une perspective sensemaking. Une majeure partie des approches du business model adopte une vision rationnelle, considérant de manière prépondérante les choix délibérés au détriment de phénomènes émergents. Par conséquent, nous interrogeons ici les mécanismes d’émergence intervenant dans le processus de développement du business model.À partir d’une étude de cas longitudinale, nous examinons le développement d’un business model sur une période de 22 mois. Nous identifions des mécanismes de sensemaking émergents et délibérés qui forment trois ‘patterns’. Ces derniers peuvent être ‘enactés’ par les acteurs pour le développement du business model et l’affinement des tactiques

White Organic Light-Emitting Diodes with fine chromaticity tuning via ultrathin layer position shifting

Non-doped white organic light-emitting diodes using an ultrathin yellow-emitting layer of rubrene (5,6,11,12-tetraphenylnaphtacene) inserted on either side of the interface between a hole-transporting NPB (4,4'-bis[N-(1-naphtyl)-N-phenylamino]biphenyl) layer and a blue-emitting DPVBi (4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl) layer are described. Both the thickness and the position of the rubrene layer allow fine chromaticity tuning from deep-blue to pure-yellow via bright-white with CIE coordinates (x= 0.33, y= 0.32), a external quantum efficiency of 1.9%, and a color rendering index of 70. Such a structure also provides an accurate sensing tool to measure the exciton diffusion length in both DPVBi and NPB (8.7 and 4.9 nm respectively)

Clusters of male and female Alzheimer's disease patients in the Alzheimer's Disease Neuroimaging Initiative (ADNI) database

This paper presents homogeneous clusters of patients, identified in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) data population of 317 females and 342 males, described by a total of 243 biological and clinical descriptors. Clustering was performed with a novel methodology, which supports identification of patient subpopulations that are homogeneous regarding both clinical and biological descriptors. Properties of the constructed clusters clearly demonstrate the differences between female and male Alzheimer’s disease patient groups. The major difference is the existence of two male subpopulations with unexpected values of intracerebral and whole brain volumes

Conception de systèmes par applications de modèles paramétrés

National audienceNous présentons nos travaux sur les composants de modèle et leur opérateur associé "apply" qui permet la conception de systèmes par assemblage de composants de modèles (rangés dans des bibliothèques). Nous illustrons ces travaux à l'aide d'un outil démonstrateur "CocoaModeler". Cet atelier UML 2 étendu aux composants de modèles supporte des chaînes de production flexibles selon différentes stratégies de ciblage et différentes plates-formes technologiques

Flow cytometry for the evaluation of anti-plasmodial activity of drugs on Plasmodium falciparum gametocytes

<p>Abstract</p> <p>Background</p> <p>The activity of promising anti-malarial drugs against <it>Plasmodium </it>gametocytes is hard to evaluate even in vitro. This is because visual examination of stained smears, which is commonly used, is not totally convenient. In the current study, flow cytometry has been used to study the effect of established anti-malarial drugs against sexual stages obtained from W2 strain of <it>Plasmodium falciparum</it>. Gametocytes were treated for 48 h with different drug concentrations and the gametocytaemia was then determined by flow cytometry and compared with visual estimation by microscopy.</p> <p>Results and conclusions</p> <p>Initially gametocytaemia was evaluated either using light microscopy or flow cytometry. A direct correlation (r²= 0.9986) was obtained. Two distinct peaks were observed on cytometry histograms and were attributed to gametocyte populations. The activities of established anti-malarial compounds were then measured by flow cytometry and the results were equivalent to those obtained using light microscopy. Primaquine and artemisinin had IC₅₀of 17.6 μM and 1.0 μM, respectively.</p> <p>Gametocyte sex was apparently distinguishable by flow cytometry as evaluated after induction of exflagellation by xanthurenic acid. These data form the basis of further studies for developing new methods in drug discovery to decrease malaria transmission.</p

Effective Interconnect Networks Design in CMOS 45 nm Circuits to Joint Reductions of XT and Delay for Transmission of Very High Speed Signals

International audienceN/