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81.
The use of glass fibre reinforced polyester composites raises many health and safety and environmental questions. One alternative is the development of high performance bio-based bio-composites with low environmental impact. Improved understanding of interfacial properties is essential to optimise the mechanical properties and durability of these materials, but so far few data are available. The present work describes the interfacial characterization of Flax fibre/Poly(lactic) acid (PLLA) system at the micro-scale using the microbond test. Different thermal treatments have been carried out (cooling rate and annealing) in order to evaluate the influence of matrix and interfacial morphologies as well as residual stress on interfacial properties. Micromechanical models have been used to determine the interfacial shear strength. When cooling rate is slow, improved interfacial properties are observed. 相似文献
82.
Christophe Chlique David Lambertin Pascal Antonucci Fabien Frizon Philippe Deniard 《Journal of the American Ceramic Society》2015,98(4):1308-1313
The purpose of this work was to study the role of cesium in sodium‐based geopolymer and its thermal stability for nuclear waste management. A series of mixed sodium and cesium geopolymer samples (Na1?x Cs x )2O·Al2O3·SiO2·12H2O (referred to as (Na1? x Cs x )‐GP, where x = 0, 0.08, 0.15, 0.42, 1) have been prepared. All geopolymer samples were heated at 1100°C for 24 h. Pollucite (CsAlSi2O6) and feldspathoid (CsAlSiO4) were crystallized from Cs‐GP. Nepheline (NaAlSiO4) and a small amount of crystallized silica were obtained from Na‐GP. The other geopolymers (Na1? x Cs x )‐GP (x = 0.08, 0.15, 0.42) led to pollucite and nepheline main phases. Amorphous silica phase was observed in all the geopolymer samples with various amounts. Phase quantification and scanning electron microscope revealed that higher Cs concentrations in Na‐GP tend to decrease the amorphous phase while improving pollucite and nepheline phase quantification. The amorphous geopolymers have also been studied by pair distribution function analysis. Tetrahedral chains formed by T–O bonding (with T = Si, Al) were shown to be more tighten around Cs+ than around Na+. It led to shorter Cs–T bond than Na–T bond matching the higher solvation property of Na+. Furthermore, thermal study analysis pointed out the fact that geopolymer samples (Na1? x Cs x )‐GP, can be considered as solid solutions. 相似文献
83.
Localized Neuron Stimulation with Organic Electrochemical Transistors on Delaminating Depth Probes 下载免费PDF全文
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Lukas C. Buelens Vladimir V. Galvita Hilde Poelman Christophe Detavernier Guy B. Marin 《化学,工程师,技术》2016,88(11):1684-1692
The kinetics of redox reactions of iron oxide in oxygen carrier 50Fe2O3/MgAl2O4 are examined using different time‐resolved techniques. Reduction kinetics are studied by H2 temperature‐programmed reduction (H2‐TPR) monitored by time‐resolved in situ XRD. In contrast to conventional TPR, in situ XRD distinguishes the three‐stage reduction of Fe2O3 → Fe3O4 → FeO → Fe. It also shows that the oxidation of Fe → Fe3O4 by CO2 has no intermediate crystalline phases, explaining why its kinetics can easily be investigated by conventional CO2 temperature‐programmed oxidation (CO2‐TPO). A shrinking core model which takes into account solid state diffusion allows describing the experimental data. 相似文献
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An overview of recent developments in volatile compounds analysis from edible oils: Technique‐oriented perspectives 下载免费PDF全文
89.
Analysis of target volatile compounds related to fishy off‐flavor in heated rapeseed oil: A comparative study of different headspace techniques 下载免费PDF全文
90.
Rami Khazaka Etienne Moulin Mathieu Boccard Loïc Garcia Simon Hnni Franz‐Josef Haug Fanny Meillaud Christophe Ballif 《Progress in Photovoltaics: Research and Applications》2015,23(9):1182-1189
We compare the performance of two back reflector designs on the optoelectrical properties of microcrystalline silicon solar cells. The first one consists of a 5‐µm‐thick low‐pressure chemical vapor deposition (LPCVD)‐ZnO electrode combined with a white sheet; the second one incorporates an Ag reflector deposited on a thin LPCVD‐ZnO layer (with thickness below 200 nm). For this latter design, the optical loss in the nano‐rough Ag reflector can be strongly reduced by smoothing the surface of the thin underlying ZnO layer, by means of an Ar‐plasma treatment. Because of its superior lateral conductivity, the thin‐ZnO/Ag back reflector design provides a higher fill factor than the dielectric back reflector design. When decreasing the roughness of the front electrode with respect to our standard front LPCVD‐ZnO layer, the electrical cell performance is improved; in addition, the implementation of the thin‐ZnO/Ag back reflector leads to a significant relative gain in light trapping. Applying this newly optimized combination of front and back electrodes, the conversion efficiency is improved from 8.9% up to 9.4%, for cells with an active‐layer thickness of only 1.1 µm. We thereby highlight the necessity to optimize simultaneously the front and back electrodes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献