FESEM and EIS Study of Sealed AA2024 T3 Anodized in Sulfuric Acid Electrolytes: Influence of Tartaric Acid

The present study investigates the effect of tartaric acid on anodic film morphology and on corrosion resistance of hydrothermally sealed anodized AA2024. Anodizing treatment was performed in dilute sulfuric acid electrolyte with or without addition of tartaric acid. Hydrothermal sealing was carried out in boiling water for each anodized specimen. The morphology of the sealed anodic films was examined using field-emission scanning electron microscopy (FESEM). Electrochemical impedance spectroscopy (EIS) was performed to assess sealing quality and corrosion resistance of the anodic films. It was shown that the sealing was more efficient in the case of anodic films formed in tartaric acid electrolyte mainly due to their lower porosity. It was also observed that the properties of the barrier layer were higher when sealing was performed on specimens anodized in the presence of tartaric acid. This suggests a specific role of the species on the barrier layer, which contributes to the enhancement of the performance in terms of corrosion resistance of the sealed anodic films. The present study clearly validates the beneficial role of tartaric acid in anodizing baths for the corrosion protection of AA2024

Former les usagers à l\u27utilisation des ressources en ligne de la bibliothèque

Partant du constat que les sites web de bibliothèque ne permettent pas toujours l\u27autonomie des usagers, la fiche pratique présente méthode et conseils pour mettre en place une formation aux fonctionnalités du site web et/ou une formation à la recherche documentaire dans le catalogue de la bibliothèque

Les lieux de culte du protestantisme wallon : une source méconnue pour l'étude d'une identité religieuse complexe

peer reviewedSpringing up from diverse origins, the Belgian Protestant minority is both discrete and highly fragmented. Present in the region without interruption since the 16th century, the movement is difficult to define. There is, for example, no commonly recognised high place, and no tradition, culture or elite capable of leaving its mark on society. Since the second quarter of the 19th century, the phenomenon has been chiefly visible in Wallonia, through its places of worship which bear witness to its roots and growth. By their diversity, their many facets and their evolution, these church buildings reveal the identity of Belgian Protestantism in all its complexity. The present article seeks to highlight this, by drawing on field studies and primary sources, some of which are in danger of extinction

UHB demonstrator interior noise control flight tests and analysis

The measurement and analysis of MD-UHB (McDonnell Douglas Ultra High Bypass) Demonstrator noise and vibration flight test data are described as they relate to passenger cabin noise. The analyses were done to investigate the interior noise characteristics of advanced turboprop aircraft with aft-mounted engines, and to study the effectiveness of selected noise control treatments in reducing passenger cabin noise. The UHB Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB engine. For these tests, the UHB engine was a General Electric Unducted Fan, with either 8x8 or 10x8 counter-rotating propeller configurations. Interior noise level characteristics were studied for several altitudes and speeds, with emphasis on high altitude (35,000 ft), high speed (0.75 Mach) cruise conditions. The effectiveness of several noise control treatments was evaluated based on cabin noise measurements. The important airborne and structureborne transmission paths were identified for both tonal and broadband sources using the results of a sound intensity survey, exterior and interior noise and vibration data, and partial coherence analysis techniques. Estimates of the turbulent boundary layer pressure wavenumber-frequency spectrum were made, based on measured fuselage noise levels

What interest to use caesium magnetometer instead of fluxgate gradiometer?

Magnetic prospecting is increasingly used to map archaeological remains. Indeed, this method has its interest compared to other approaches, such as electrical resistivity method. Independent of the soil water content, it combines speed with high spatial resolution. Moreover, the sensors developed over the last fifteen years are sensitive to minimal changes in the magnetic signal. They rely on instrumental principles that can be very different. Caesium magnetometers and fluxgate gradiometers a..

Towards norms for accreditation of biobanks for human health and medical research:Compilation of existing guidelines into an ISO certification/accreditation norm-compatible format

In recent years, biobanks have evolved into professional infrastructures that acquire, validate, process, store, manage and distribute biological material of human origin to public or private end-users/researchers. This article (a) highlights the importance of quality assurance for both the biobank basic processes and sample annotation in order to ensure reliable results of research based on these samples, (b) suggests that certification according to international standards can contribute to the organization of the biobanking processes while accreditation can contribute to the organization of sample characterization/validation, and (c) provides a compilation of all existing guidelines against an International Organization for Standardization (ISO) format.</p

Interleukin 9–induced In Vivo Expansion of the B-1 Lymphocyte Population

The activity of interleukin (IL)-9 on B cells was analyzed in vivo using transgenic mice that constitutively express this cytokine. These mice show an increase in both baseline and antigen-specific immunoglobulin concentrations for all isotypes tested. Analysis of B cell populations showed a specific expansion of Mac-1+ B-1 cells in the peritoneal and pleuropericardial cavities, and in the blood of IL-9 transgenic mice. In normal mice, the IL-9 receptor was found to be expressed by CD5+ as well as CD5− B-1 cells, and repeated injections of IL-9 resulted in accumulation of B-1 cells in the peritoneal cavity, as observed in transgenic animals. Unlike other mouse models, such as IL-5 transgenic mice, in which expansion of the B-1 population is associated with high levels of autoantibodies, IL-9 did not stimulate the production of autoantibodies in vivo, and most of the expanded cells were found to belong to the B-1b subset (IgM+Mac-1+CD5−). In addition, we found that these IL-9–expanded B-1b cells do not share the well-documented antibromelain-treated red blood cell specificity of CD5+ B-1a cells. The increase of antigen-specific antibody concentration in immunized mice suggests that these B-1 cells are directly or indirectly involved in antibody responses in IL-9 transgenic mice