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Slope stability is one of the crucial factors to consider in every civil engineering project. One widely used method to stabilize slope is the use of polymeric products called geosynthetics. Natural fiber geosynthetics used for geotechnical applications have attracted attention because of their environmental and economic benefits. Coir fibers made into nonwoven geotextiles are utilized in this study as an alternative material for slope stabilization. One drawback of coir fiber geotextiles is their low tensile strength and limited life span due to their susceptibility to environmental factors. This study was conducted to evaluate the effect of mercerization and bleaching treatment on the strength performance of nonwoven coir geotextiles after exposure to conditions simulating biological and chemical degradation. Microscopic images of treated coir geotextiles show the removal of surface impurities that altered the physical components in the fiber. The grab tensile strength results prove that the mercerized coir geotextiles are suitable for field conditions and groundwater exposure. The untreated coir geotextiles showed superior puncture resistance relative to the chemically treated geotextiles. The chemical treatments improved the tensile strength; however, they weakened the puncture resistance of the coir geotextile due to the decrease in thickness. A slope stability simulation conducted using Rocscience Slide2 version 9.017 software proved that coir geotextiles can effectively reinforce slopes, with strength performance almost comparable to that of synthetic geotextiles.

Food packaging has seen a growth in the use of materials derived from renewable resources such as poly(lactic acid) (PLA). However, the initial costs to produce bioplastics are typically high. Tropical fruit waste as naturally sourced fibres, such as jackfruit skin, can be used as a cost-reducing filler for PLA. The main objective in this study is to fabricate a low-cost natural fibre-reinforced polymer that potentially applies in packaging with the aid of bleaching treatment. The treatment shows a rougher surface fibre in Scanning electron microscopy (SEM) micrographs and it is expected to have better mechanical locking with the matrix, and this is found similar with a Fourier-transform infrared spectroscopy (FTIR) analysis. Unfortunately, fibre insertion does find low tensile performances, yet bleached-fibre composites improved its performance significantly. A similar situation was found in the thermal characterization where a low-thermal stability natural fibre composite has lower thermal behaviour and this increased with bleaching treatment. Besides, bleached-fibre composites have a longer service period. Besides, a 15 wt% thymol insertion inhibits the growth of Gram-positive bacteria in the composites and the non-treated fibre composite has better thymol effects. The 30 wt% of the bleached-fibre insertion composite has a high potential to reduce the cost of bioplastic products with minimum alterations of overall performances.

In this work, biodegradable composites from poly(lactic acid) (PLA) and oil palm empty fruit bunch (OPEFB) fiber were prepared by melt blending method. Prior to mixing, the fiber was modified through bleaching treatment using hydrogen peroxide. Bleached fiber composite showed an improvement in mechanical properties as compared to untreated fiber composite due to the enhanced fiber/matrix interfacial adhesion. Interestingly, fiber bleaching treatment also improved the physical appearance of the composite. The study was extended by blending the composites with commercially available masterbatch colorant.

8 pages; International audience; In a recent editorial (Proc. Natl. Acad. Sci., 2013 110, E2144-E2146) and elsewhere, questions have been raised regarding the experimental practices in relation to the proteomic analysis of organic matrices associated to the biomineralized CaCO3 skeletons of metazoans such as molluscan shells and coral skeletons. Indeed, although the use of new high sensitivity MS technology potentially allows to identify a greater number of proteins, it is also equally (or even more) sensitive to contamination of residual proteins from soft tissues, which are in close contact with the biomineral. Based on our own past and present experimental know-how-observations that are reproducible and coherent with the current understanding of extracellular biomineralization processes-we are convinced that a careful and appropriate cleaning of biominerals prior to any analysis is crucial for accurate proteomic investigations and subsequent pertinent interpretation of the results. Our goal is to alert the scientific community about the associated bias that definitely should be avoided, and to provide critical recommendations on sample preparation and experimental design, in order to better take advantage of the aptness of proteomic approaches aiming at improving our understanding of the molecular mechanisms in biomineralization.

Les auteurs étudient les caractères chimiques et physiques de trois charbons végétaux ainsi que quelques paramètres pouvant influer sur leur efficacité (teneur en colloïdes, température de traitement, etc.). Ils montrent que le traitement de décoloration d'un moût de raisins Pinot noir ne modifie que très légèrement les composés aromatiques du vin obtenu. Ils observent que le traitement par le charbon des vins blancs madérisés entraîne une modification de leurs teneurs en composés aromatiques qui dépend, en premier lieu, du type de charbon utilisé. L'instabilité à l'oxydation des vins traités semble liée à la structure chimique du charbon.+++Chemical and physical properties of three vegetal charcoals and their efficiency according to some parameters (colloid level, temperature of treatment) were studied. It was shown that bleaching treatment of a red Pinot noir must changed very slightly the aromatic compounds of the corresponding wine. For oxidised white wines, changes in the level of aromatic compounds occured, firstly according to the tye of charcoal used. The instability of treated wines toward oxidation appared in connection with the chemical structure of the charcoal.