Correlation between thermal properties and aluminum fractions in CrAlN layers deposited by PVD technique

The CrAlN coatings are a good alternative to conventional CrN coatings especially for high temperature oxidation-resistance applications. Different CrAlN coatings were deposited on silicon (100) by PVD (Physical vapor deposition) technique from two targets (chromium and aluminum) in a reactive nitrogen atmosphere at aluminum applied negative voltage ( 300, 500, 700 and 900 V). The composition, structural, mechanical and thermal properties of the as-deposited coatings were systematically characterized by energy dispersive analysis of X-rays, X-ray diffraction, nanoindentation, and the ‘‘Mirage effect’’ experiments. The X-ray diffraction (XRD) data show that in general CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1) and (2 0 0) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing aluminum proportion the coatings became more compact and denser and their increased correspondingly, showing a maximum hardness of about 36 GPa (30 at% of Al) which is higher than that of CrN. Moreover, the results in this work demonstrate that the variation of aluminum fraction alter the resulting columnar grain morphology and porosity of the coatings. However, the thermal properties are greatly affected by these morphological alterations. The correlation between aluminum fraction in CrAlN coatings and its thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by a decrease of the stitch parameter dimension

Experimental investigation of the mechanical micro structural and thermal properties of thin CrAIN layers deposited by PVD technique for various aluminum percentages

The thin film of chromium nitride and their derivatives obtained by the filing process physical vapor deposition attract more and more attention from industry given their high resistance to wear. This quality of these coatings may be linked to their good mechanical and tribological properties. Several experimental investigations have led to the development of CrAlN (Chronium Aluminum Nitride) hard coatings by varying the aluminum target bias voltage, in preference to the traditional CrN coating. The present work is based on the investigation of physical and mechanical properties of CrAlN coating deposited on a silicon substrate and the effect of the aluminum proportion on their variation. The results demonstrate that variation in aluminum proportion alters the resulting columnar morphology, porosity and the thermal properties. The correlation between aluminum proportions in CrAlN coatings and his thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by decrease of the stitch parameter dimension

Being Human in Medicine: Beyond Hierarchy

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Effect of duplex treatments by plasma nitriding and triode sputtering on corrosion behaviour of 32CDV13 low alloy steel

This paper presents corrosion behaviour of duplex treated low alloy steel. Different kinds of samples were tested: non-treated, plasma nitrided, ZrBN-triode sputtered and ZrBN-duplex treated samples. The corrosion behaviour was evaluated by electrochemical techniques (corrosion potential and polarisation resistance evolutions versus immersion time, potentiodynamic curves). The corrosion tests were carried out in neutral aqueous saline solution (NaCl 30 g L−1), naturally aerated. The composition and the structure of layers were determined by EDS and XRD, respectively, while the morphology was observed by SEM. Experimental results showed that the corrosion current density Icorr increased with decreasing white layer thickness in plasma nitrided specimens. The nitrides ε-Fe2 − 3N and γ′-Fe4N present in the white layer are nobler than the substrate but may promote, by galvanic effect, a localised corrosion through open porosity. The duplex treated specimens (nitriding+ZrBN coating) present better corrosion protection and enable to overcome the drawbacks of both techniques, mainly the porosity of the deposited films

Interactions between prostaglandins, leukotrienes and HIV-1: Possible implications for the central nervous system

In HIV-1-infected individuals, there is often discordance between viremia in peripheral blood and viral load found in the central nervous system (CNS). Although the viral burden is often lower in the CNS compartment than in the plasma, neuroinflammation is present in most infected individuals, albeit attenuated by the current combined antiretroviral therapy. The HIV-1-associated neurological complications are thought to result not only from direct viral replication, but also from the subsequent neuroinflammatory processes. The eicosanoids - prostanoids and leukotrienes - are known as potent inflammatory lipid mediators. They are often present in neuroinflammatory diseases, notably HIV-1 infection. Their exact modulatory role in HIV-1 infection is, however, still poorly understood, especially in the CNS compartment. Nonetheless, a handful of studies have provided evidence as to how these lipid mediators can modulate HIV-1 infection. This review summarizes findings indicating how eicosanoids may influence the progression of neuroAIDS

Innovations et stratégies logistiques dans la filière vitivinicole. Le rôle des proximités

L’objectif de cet article est d’identifier comment les entreprises de la filière vitivinicole bourguignonne articulent les différentes formes de proximités pour gérer leur stratégie logistique aval (du départ de la cave au client) et les innovations qu’elles ont mises en place pour résoudre leurs problèmes logistiques. Une analyse réalisée, à partir des informations collectées auprès de 36 entreprises en Bourgogne, nous a permis de classer les entreprises en quatre catégories selon la combinaison de proximités élaborée : proximités géographique et organisée mais aussi proximité circulatoire qui tient compte de la qualité et de la fiabilité des transports.The objective of this paper is to identify how companies of Burgundian wine sector articulate the proximities to manage their downstream logistics strategy (departure from the enterprise to client) and the innovations they have implemented to solve their logistics problems. An analysis, based on information collected from 36 companies in Burgundy, have allowed us to classify firms into four categories according to the articulation of proximities implemented by companies: geographical and organized proximities but also circulatory proximity that takes into account the quality and reliability of transport

SNAT7 is the primary lysosomal glutamine exporter required for extracellular protein-dependent growth of cancer cells

Significance Lysosomes are degradative intracellular organelles essential to cell maintenance and homeostasis. Although their degradative function is well documented, the proteins responsible for the efflux, and reuse, of lysosomal degradation products remain largely unknown. In this study, we identify the transporter responsible for lysosomal efflux of glutamine, an amino acid central to several key metabolic pathways. This central role of glutamine is exploited by several types of cancer cells with increased consumption of glutamine. Interestingly, genetic inactivation of the transporter impairs their growth under conditions of limited glutamine availability when internalized extracellular proteins are used as an alternative source of amino acids, suggesting novel approaches for anticancer therapies.</jats:p

The Hertzsprung-gap giant 31 Comae in 2013: Magnetic field and activity indicators

We have observed the giant star 31 Comae in April and May 2013 with the spectropolarimeter Narval at Pic du Midi Observatory, France. 31 Comae is a single, rapidly rotating giant with rotational period ~6.8 d and vsini ~ 67 km/s. We present measurements and discuss variability of the longitudinal magnetic field (Bl), spectral activity indicators Hα, CaII H&K, Ca II IR triplet and evolutionary status. Our future aim is to perform a Zeeman-Doppler imaging study for the sta