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Saint-Sauveur-en-Rue, France

Kinata S.E.,Ecole des Mines de Nantes | Loubar K.,Ecole des Mines de Nantes | Paraschiv M.,Ecole des Mines de Nantes | Belloncle C.,Ecole Superieure du Bois | Tazerout M.,Ecole des Mines de Nantes
Bioresource Technology | Year: 2012

In this paper, pyrolysis and hydroliquefaction processes were successively used to convert CCB-treated wood into bio-oil with respect to environment. Pyrolysis temperature has been optimized to produce maximum yield of charcoal with a high metal content (Cu, Cr, and B). The results obtained indicate that the pyrolysis at 300. °C and 30. min are the optimal conditions giving high yield of charcoal about 45% which contains up to 94% of Cu, 100% of Cr and 88% of B. After pyrolysis process, the charcoal has been converted into bio-oil using hydroliquefaction process. The optimization approach for the yield of bio-oil using a complete factorial design with three parameters: charcoal/solvent, temperature and hydrogen pressure was discussed. It is observed that the temperature is the most significant parameter and the optimum yield of bio-oil is around 82%. The metal analysis shows that the metals present in the bio-oil is very negligible. © 2012 Elsevier Ltd. Source

Schoefs F.,CNRS Research Institute in Civil Engineering and Mechanics | Le K.T.,CNRS Research Institute in Civil Engineering and Mechanics | Le K.T.,Sudan University of Science and Technology | Lanata F.,Ecole Superieure du Bois
Computers and Geotechnics | Year: 2013

For several decades, many structures have been monitored during maintenance or during their service lives to analyse long-term behaviour. A large number of sensors, properly distributed in the structure, are necessary, especially if the structure is complex and includes significant spatial variability. When probabilistic modelling is applied, because of intrinsic uncertainties in the model as well as uncertain physical parameters, monitoring measurements can be used to identify the parameters of the structural model. This paper presents a monitoring example of a pile-supported wharf in which tie rods are instrumented and the geotechnical characteristics of the soil embankment are identified. The modelling is performed using a meta-model fitted with a numerical database obtained from direct simulations with a finite element model implemented with Plaxis. A full quadratic response surface model (RSM) is the most efficient approximation to fit the original finite element model. The identified soil parameters enable the model to describe the variability of the measured loading in the tie rods. © 2013 Elsevier Ltd. Source

Poaty B.,Laval University | Vardanyan V.,Laval University | Wilczak L.,Laval University | Wilczak L.,Ecole Superieure du Bois | And 2 more authors.
Progress in Organic Coatings | Year: 2014

Cellulose nanocrystal (CNC), an emerging renewable nanomaterial, was subjected to carbon chains grafting in order to improve its dispersion and its ability to transfer its rigidity properties into less polar matrixes, especially acrylic wood coatings. Chemical modifications used to this purpose are required to be simple, not affecting the CNC main structure and compatible or synergistic to oligomer reticulation inside the targeted UV-waterborne formulation. Those modifications were carried out using either alkyl quaternary ammonium bromides or acryloyl chloride. These new chemical functionalities, not inducing deep structural changes in modified CNCs, were highlighted through nuclear magnetic resonance, infrared and nitrogen content analyses. CNC derivatives were better dispersed in aqueous acrylic coating as suggested by atomic force microscopy, with a mean surface roughness falling from 9 to 6 nm on the coatings containing unmodified and treated CNCs, respectively. For mechanical evaluations, the coatings including various CNC derivatives were applied on sugar maple wood, a much appreciated material as indoor timber or wooden furniture which requires an efficient surface protection. The abrasion tests indicated that the modified CNCs confer a higher scratch resistance, with an improvement from 24% to 38% for coatings containing CNC derivatives over those with unmodified CNC. © 2014 Elsevier B.V. Source

Lanata F.,Ecole Superieure du Bois
Advanced Materials Research | Year: 2013

Structural design, regardless of construction material, is based mainly on deterministic codes that partially take into account the real structural response under service and environmental conditions. This approach can lead to overdesigned (and expensive) structures. The differences between the designed and the real behaviors are usually due to service loads not taken into account during the design or simply to the natural degradation of materials properties with time. This is particularly true for wood, which is strongly influenced by service and environmental conditions. Structural Health Monitoring can improve the knowledge of timber structures under service conditions, provide information on material aging and follow the degradation of the overall building performance with time. A long-term monitoring control has been planned on a three-floor structure composed by wooden trusses and composite concrete-wood slabs. The structure is located in Nantes, France, and it is the new extension to the Wood Science and Technology Academy (ESB). The main purpose of the monitoring is to follow the long-term structural response from a mechanical and energetic point of view, particularly during the first few service years. Both static and dynamic behavior is being followed through strain gages and accelerometers. The measurements will be further put into relation with the environmental changes, temperature and humidity in particular, and with the operational charges with the aim to improve the comprehension of long-term performances of wooden structures under service. The goal is to propose new improved and optimized methods to make timber constructions more efficient compared to other construction materials (masonry, concrete, steel). The paper will mainly focus on the criteria used to design the architecture of the monitoring system, the parameters to measure and the sensors to install. The first analyses of the measurements will be presented at the conference to have a feedback on the performance of the installed sensors and to start to define a general protocol for the Structural Health Monitoring of such type of timber structures. © (2013) Trans Tech Publicutions, Switzerland. Source

Monthly samples of the axillary seabream Pagellus acarne (Risso, 1826) were obtained from commercial catches landed from central Algerian coastal areas, by Algiers fleets (90% bottom trawlers and 10% artisanal fleet using both gillnets and handline). A total of 984 specimens were randomly sampled between September 2011 and August 2013. Biometry was performed for total length (TL), total weight (WT), eviscerated body weight (EW) and gonad weight (GW), and the gonadosomatic indexes (GSI) were calculated. Fish sex was recorded and the maturation states of the gonads were determined macroscopically. Classification of sexual stages was based on the gonadal development criteria described by Lamrini et al. (1998), modified into a five-stage scale: (I) immature, (II) developing, (III) mature, (IV) spawning, and (V) recovering spent/post-spawning. Three predictors of fecundity (Y), LT, WT and WG were evaluated and regression equation derived. The size at sexual maturity was estimated 16.45 cm for females and 16.80 cm for males. The proportion of males decreases as length increases, which is consistent with the fact that P. acarne is known as a protandric hermaphroditic species. In the study areas, the reproduction of P. arcane occurred over an extensive spawning period, first from March to June and later in October. The power model between fecundity and total weight was the best predictor model given by the equation F = 1312.4 WT0.85. The individual fecundity ranged from 14,500 to 182,300 oocytes corresponding to females 22.15 ± 0.45 cm TL, 148.03 ± 9.69 g body weight and 5.90 ± 0. g gonad weight. Traditional coastal fisheries should be restricted to preserve the ability of broodstock renewal for this species. © SFI. Source

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