Impact of sun patch and three-dimensional heat transfer descriptions on the accuracy of a building’s thermal behavior prediction

A thermal transient numerical model (M_3D) which considers the three-dimensional heat transfer through the envelope of a room and the sun patch through a window has been developed and validated in a recent paper. The use of a refined spatial and temporal discretization allows considering more precise interactions between the sun patch projection with the structure and quick time perturbations in the stresses. This is particularly necessary for highly insulated and low energy consumption buildings. In this new paper, M_3D is subsequently transformed to simpler configurations, close to classical modelling thermal building simulation software that neglects the sun patch and the 3D heat transfer, in order to quantify the main contributions of this model. A first configuration is to consider one-dimensional heat conduction for the envelope and the transmitted solar radiation is only projected onto the floor (M_1D). A second configuration considers also one-dimensional heat conduction but the transmitted beam radiation falls on each wall or floor that is impacted (M_1D,sp). Comparison between experimental data and numerical results of these three models shows, as expected, that M_1D and M_1D,sp are less accurate than M_3D. This is particularly true when wanting to evaluate surface temperature distributions or heating power evolution in winter.     

Development on systems configuration in ITER Tokamak Complex and Auxiliary Buildings

The ITER site consists of almost 30 buildings to service the Tokamak machine which is located in the centre of the Tokamak Complex facility with the Tokamak-, Diagnostic- and Tritium building.The design of a large part of the ITER plant systems will be executed by the ITER Domestic Agencies or their industrial suppliers under functional specifications provided by the ITER Organization. At the same time, the detailed design of the building is carried out by the European Domestic Agency ‘Fusion for Energy’ (F4E).In order to allow an efficient identification of the ITER configuration as well as to manage the concurrent engineering activities and to simplify the identification and assessment of changes, the design of each ITER plant systems is described in the so-called Configuration Management Models (CMM). These are light CATIA^® 3D models that define the required space envelope and the physical interfaces in-between the systems and the buildings.The paper describes the procedure adopted for the control of the baseline configuration of the Tokamak Complex facility and Auxiliary Buildings with their associated plant systems and illustrates the current status as well as recent developments in the different systems.     

Influence of the 316 L stainless steel interface on the stability and barrier properties of plasma fluorocarbon films

Coatings are known to be one of the more suited strategies to tailor the interface between medical devices and the surrounding cells and tissues once implanted. The development of coatings and the optimization of their adhesion and stability are of major importance. In this work, the influence of plasma etching of the substrate on a plasma fluorocarbon ultrathin coating has been investigated with the aim of improving the stability and the corrosion properties of coated medical devices. The 316 L stainless steel interface was subjected to two different etching sequences prior to the plasma deposition. These plasma etchings, with H(2) and C(2)F(6) as gas precursors, modified the chemical composition and the thickness of the oxide layer and influenced the subsequent polymerization. The coating properties were evaluated using flat substrates submitted to deformation, aging into aqueous medium and corrosion tests. X-ray photoelectron spectroscopy (XPS), time of flight-secondary ion mass spectrometry (ToF-SIMS), ellipsometry, and atomic force microscopy (AFM) were performed to determine the effects of the deformation and the aging on the chemistry and morphology of the coated samples. Analyses showed that plasma etchings were essential to promote reproducible polymerization and film growth. However, the oxide layer thinning due to the etching lowered the corrosion resistance of the substrate and affected the stability of the interface. Still, the deformed samples did not exhibited adhesion and cohesion failure before and after the aging.     

Cation and anion disorder in HgBa2Can−1CunO2n+2+δ

Cu and C substitution for Hg in Hg-based cuprate superconductors is discussed. The large Hg Debye-Waller factor usually obtained from refinements based on diffraction data should be interpreted as an indication of carbon substitution for the Hg cations. This assumption is corroborated by HREM, powder x-ray anomalous dispersion, and powder neutron diffraction investigations.     

Experimental analysis of damage creation and permanent indentation on highly oriented plates

This paper presents an experimental investigation concerning low-velocity impact and quasi-static indentation tests on highly oriented laminates used in aeronautical and aerospace applications. The damage observed in such laminates is very particular. Post mortem analysis were carried out which helped to define an impact damage scenario. Microscopic observations led to explain the mechanism of permanent indentation formation which is a fundamental point of damage tolerance justification. Equivalence between static and dynamic is also discussed.     

Poisoning of platinum surfaces by hexamethyldisiloxane (HMDS): application to catalytic methane sensors

The evolution of the catalytic activity of platinum ribbons towards methane oxidation has been studied as a function of the exposure to hexamethyldisiloxane (HMDS) at various temperatures. Below 950 K, and at moderate exposure, HMDS acts as an inhibitor, the surface is progressively covered by patches of silica and the number of active sites decreases as the exposure to HMDS is increased. Above 950 K, the interaction of platinum with HMDS produces irreversibly the formation of a silica overlayer, the mechanism of the catalytic oxidation of methane is deeply modified. The consequences on the resistance of catalytic methane sensors are analysed as a function of the working conditions.     

Evolution of crystallographic texture during equal channel angular extrusion of copper: The role of material variables

The evolution of crystallographic texture during equal channel angular extrusion (ECAE) using route A has been investigated experimentally as well as by simulations for three types of materials: pure, commercially pure, and impure (cast) copper. The ECAE texture of copper can be compared with simple shear textures. However, there are deviations in terms of location of the respective components. These differences can be nearly reproduced using a recent flow line approach for ECAE deformation (L.S. Tóth, R. Arruffat-Massion, L. Germain, S.C. Baik, and S. Suwas: Acta Mater., 2004, vol. 52, pp. 1885–98) with the help of the viscoplastic self-consistent polycrystal model. The main texture components common to all three materials are A_1E and B_E/B_E; the latter ones are significantly stronger in the cast material. The effect of further deformation on texture modification depends on material variables, such as purity, initial microstructure, and texture.