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Methods to test the safety of wood material for hygienically sensitive places are indirect, destructive and limited to incomplete microbial recovery via swabbing, brushing and elution-based techniques. Therefore, we chose mCherry Staphylococcus aureus as a model bacterium for solid and porous surface contamination. Confocal spectral laser microscope (CSLM) was employed to characterize and use the autofluorescence of Sessile oak (Quercus petraea), Douglas fir (Pseudotsuga menziesii) and poplar (Populus euramericana alba L.) wood discs cut into transversal (RT) and tangential (LT) planes. The red fluorescent area occupied by bacteria was differentiated from that of wood, which represented the bacterial quantification, survival and bio-distribution on surfaces from one hour to one week after inoculation. More bacteria were present near the surface on LT face wood as compared to RT and they persisted throughout the study period. Furthermore, this innovative methodology identified that S. aureus formed a dense biofilm on melamine but not on oak wood in similar inoculation and growth conditions. Conclusively, the endogenous fluorescence of materials and the model bacterium permitted direct quantification of surface contamination by using CSLM and it is a promising tool for hygienic safety evaluation.

Healthcare-associated infections (HAI) remain a burden in healthcare facilities, environmental surfaces being a potential reservoir for healthcare-associated pathogens. In this context, exploration of materials with potential antimicrobial activities represents a way forward for the future. Here, we explored the survival of four bacterial species commonly involved in HAI (Acinetobacter baumannii, Enterococcus faecalis, Klebsiella pneumoniae, Staphylococcus aureus), on oak versus three other materials (aluminum, polycarbonate, stainless steel). Twenty microliters of each bacterial suspension (approximatively 107 bacteria) were deposited on each material. Bacterial counts were measured by grinding and culturing on day 0, 1, 2, 6, 7 and 15. Analyses were performed in triplicate for each material and each time evaluated. It appeared that the bacteria viable count decreased rapidly on transversal and tangential oak compared with the other materials for all bacterial species. Furthermore, no difference was noticed between transversal and tangential oak. These results underline the potential for use of oak materials in healthcare facilities, a consideration that should be supported by further investigations.

International audience; Aim: To assess the activity of Quercus petraea (oak) on five bacterial species/genus frequently involved in hospital-acquired infections for evaluating the interest of going further in exploring the possibilities of using untreated wood as a material in the hospital setting. Materials & methods: We studied the activity of Q. petraea by the disk diffusion method. Results: Q. petraea was active on Staphylococcus aureus and Acinetobacter coalcoaceticus-baumannii complex, two bacterial species particularly resistant in the hospital environment, independently from their resistance to antibiotics, and was slightly active on Pseudomonas aeruginosa. Concurrently, Q. petraea was not active on Enterococci and Escherichia coli. Conclusion: Overall, untreated wood material presented antimicrobial properties that could have an impact on the cross-transmission of certain bacterial species in healthcare settings.

Spent coffee grounds (SCGs) represent a huge amount of global waste whose post-use disposal triggers environmental issues. In this study, SCGs were successfully treated and modified to improve the mechanical properties of biobased composites with epoxy matrix. A two-step treatment was proposed, pretreating by a NaOH solution and modifying by maleic anhydride (MA). MA acts as a coupling agent to create the internal network in composite through the interaction between functional groups. Accordingly, MA improves the interface between phases in composite, ensures a better physical property compared to the composite without modification. Consistently, the two-step treatment depicts improved mechanical properties: flexural modulus and flexural strength increased to 3053 MPa and 45 MPa, respectively, compared to 2429 MPa and 33 MPa for composite with pure SCGs.

Birds ingest ethanol when farmers feed it to treat mild respiratory infections and to improve the feed conversion ratio (FCR) or when birds are exposed to ethanol as avian models in alcohol-related...

International audience; Wood materials are being adopted as nature-based architectural themes inside the healthcare buildings. Concern is raised that the organic and porous character of wood might support microbial survival. Therefore, this review discusses the hygienic properties of wood including the antimicrobial potential and its cleanability in comparison to smooth surface materials. In general, wood has antimicrobial properties owing to its chemical composition and physical structure. However, the hygienic potential of wood is influenced by the type of wood, age of wood, the cleaning method, surface treatment, and its moisture content. This information is intended to guide decision-makers regarding the use of wood in hygienically sensitive places and researchers to help them identify the variables for better utilizing the hygienic potential of this material.

The weathering of wood, and especially modified wood, through abiotic factors has been extensively studied. Much less research has been conducted on the influence of biotic factors on untreated wood in exterior use that is not in ground contact, i.e. use class 3. There is especially a lack of research concerning the influence of the presence of bacterial and fungal communities on the weathering process of wood. The hypothesis is set that interacting mechanisms between fungi and bacteria as well as between microorganisms and abiotic factors have an impact on the pace of the weathering of wood. The aim of the project is to identify synergistic effects between biotic factors such as bacteria (Eubacteria) and fungi (Basidiomycota and Ascomycota) and abiotic factors such as light, temperature and moisture on the weathering of oak (Quercus petraea), Douglas fir wood (Pseudotsuga menziesii) and partially chest nut (Castanea sativa) in use class 3. In order to measure the influence of weather ing, different visual, chemical, mechanical and microbiological methods were used. Multiple weathering methods were applied to degrade wood samples in natural and artificial conditions. Artificial weathering provided the opportunity of eliminating certain degrading factors and therefore observe the influence of specific factors on the degradation process of wood.; Le vieillissement du bois par des facteurs abiotiques, a fait l’objet de nombreuses études, portant surtout sur du bois traité ou modifié chimiquement. Peu d´entre elles ont été menées sur l’influence des facteurs biotiques sur du bois non traité utilisé à l’extérieur mais sans contact avec le sol, c’est-à-dire en classe d’emploi 3. L’influence de la présence de communautés bactériennes et fongiques pendant le vieillissement du bois est ainsi très peu documentée. L´hypothèse que les mécanismes d'interaction entre les champignons et les bactéries, ainsi qu'entre les microorganismes et les facteurs abiotiques, ont un impact sur la vitesse du vieillissement du bois reste donc posée. L’objectif du projet est d’identifier les effets de synergies entre les facteurs biotiques, tels que les bactéries (Eubactéries), les champignons (Basidiomycota et Ascomycota) et les facteurs abiotiques, tels que la lumière, la température et l’humidité pendant le vieillissement de bois de chêne (Quercus petraea), de Douglas (Pseudotsuga menziesii) et partiellement de châtaigner (Castanea sativa) pour une utilisation en classe d’emploi 3. Afin de mesurer le changement de l´état des surfaces en bois, différentes méthodes visuelles, chimiques, mécaniques et microbiologiques ont été utilisées. Plusieurs méthodes de vieillissement ont été appliquées pour faire vieillir les échantillons de bois dans des conditions naturelles, ainsi que pour simuler le vieillissement tout en éliminant certains facteurs de dégradation et donc observer l'influence de facteurs spécifiques sur le processus de dégradation du bois.

The wood material provides a nature-based theme to construction because of its natural appearance, ecofriendly nature and biophilic effects on humans. However, its organic and porous nature is questioned when using it in hygienically important places such as hospitals. Studies have shown that wood has antimicrobial properties against some pathogens; work is still needed, however, to demonstrate this antimicrobial action and its relation to wood and microbiological variables. This research gathers and generates information to guide stakeholders of hospital hygiene on the hygienic safety of wood materials. First, a simple and direct method was developed to study the antibacterial and antifungal activity of solid wood, which also identified the role of wood and microbial variables on antimicrobial behavior. Further, an elution based bacterial recovery method was investigated which showed that the most common nosocomial bacteria did not survive as well on wood as compared to smooth surfaces such as aluminum, steel and polycarbonate. Meanwhile, an innovative tool was developed, involving the use of fluorescent probes to study the bacterial distribution on and inside wood using confocal spectral laser microscopy. These experiments produced the information that will help the decision makers regarding the choice of wood material in the healthcare buildings. It not only enhances our understanding of hygienic safety of wood in healthcare buildings but also provides the basis for future research on the prevalence of pathogens in the wooden healthcare institutes and the perception of the occupants those buildings.; Le matériau bois est un composant bien connu des thèmes de construction basés sur la nature en raison de son aspect naturel, de sa nature écologique et de ses effets biophiles chez l'homme. L'utilisation de ce matériau dans des endroits sensibles sur le plan de l'hygiène est toutefois remise en question en raison de sa nature organique et poreuse. Des études antérieures ont montré que le bois possède des propriétés antimicrobiennes contre de nombreux microorganismes importants du point de vue de l'hygiène. Les travaux sont encore nécessaires pour démontrer cette action antimicrobienne et sa relation avec le bois et les variables microbiologiques. Cette recherche visait à rassembler et à générer des informations pour guider les acteurs de l'hygiène hospitalière en ce qui concerne la sécurité hygiénique du matériau bois. Les méthodes ont été développées pour étudier l'action antimicrobienne du bois et identifier les variables qui influencent ce comportement. La première méthode développée dans ce contexte a été une méthode de diffusion directe sur gélose (appelée antiboisgram) qui a donné de bons résultats en ce qui concerne le - - dépistage de plusieurs espèces de bois pour leur action antibactérienne et antifongique. Elle a également permis d'identifier le rôle du bois et des variables microbiennes dans la détermination des propriétés antimicrobiennes du matériau en bois. En outre, une méthode de récupération bactérienne basée sur l'élution a été étudiée, qui a montré que la plupart des bactéries nosocomiales courantes survivent moins bien sur le bois que sur les surfaces lisses. Parallèlement, un outil innovant a été mis au point, impliquant l'utilisation de sondes fluorescentes pour étudier la distribution des bactéries sur et à l'intérieur des matériaux en bois à l'aide de la microscopie laser spectrale confocale. Ces expériences ont permis d'obtenir des informations fructueuses qui pourraient améliorer la compréhension du rôle du bois dans la sécurité hygiénique des bâtiments de soins de santé. En outre, les futures recherches et les directives d'application ont été fournies concernant la prévalence des pathogènes dans les bâtiments de soins de santé en bois et la perception des occupants des hôpitaux vis-à-vis de l'environnement intérieur en bois.

Ostrich farming serves as a source for meat, feathers, skin, eggs, and oil. In general, ostriches are hardy birds that can resist a wide range of climatic harshness and some diseases. However, musculoskeletal and digestive complications, including the gastric impaction, remain the major cause of mortality. The gastrointestinal impaction alone is responsible for 30 – 46% of spontaneous deaths in growing ostriches. The literature review of 21 publications on this subject has shown that 90% of these incidents happen during first six months of life. The aetiology of this problem is mostly stress and behaviour-related gorging of feed and picking on non-feeding materials such as stone, sand, wood pieces, plastic, glass, and metallic objects. Conservative therapy or surgical approaches show good results with almost 70 to 100% recovery depending upon the clinical presentation and timely diagnosis. Overall, this literature review describes impaction in farmed ostriches, along with diagnosis, treatment, and control and preventive measures. This information will help stakeholders understand the gastrointestinal impaction in ratites to better manage this issue, reduce economic losses, and improve welfare of the birds.

The present investigation aimed to utilize a direct wood disc diffusion method to study the influence of plane of cutting, cutting method, sterilization method, and origin of tree on the antimicrobial activity of wood material. Six oak wood trees (Quercus petraea) were collected from 3 different locations in France. They were cut into 4 mm thick slices with either transverse (RT), tangential (LT) or radial (LR) faces. Round discs (diameter 9.95 &plusmn, 0.1 mm) were cut from the slices via a laser machine or a manual punch machine, and were sterilized with gamma irradiation (25 kGy) or autoclaving (121 &deg, C). The antimicrobial activity of wood was tested using a direct diffusion method against Staphylococcus aureus and Acinetobacter baumannii isolates. The zone of inhibition around the wooden disc was recorded following the recommendations used for antibiotics tests. The results showed that S. aureus was more susceptible than A. baumannii, to the chemicals that diffused from the wood. The transverse face discs exhibited higher antimicrobial activity. Samples that had been sterilized by autoclaving showed significantly (p &lt, 0.05) lower antimicrobial activity, whereas the cutting method and origin of tree did not influence the antimicrobial activity of wood material. Therefore, the choice of sterilization method and cutting planes must be taken into account while studying and interpreting the antibacterial properties of wood material.

This article investigates the feasibility of replacing metal robot links by wooden bodies for eco-sustainable design’s purpose. Wood is a material with low environmental impact and a good mass-to-stiffness ratio. However, it has significant dimensional and mechanical variabilities. This is an issue for industrial robots that must be accurate and stiff. To guarantee stiffness and accuracy performance of a wooden robot, we propose an integrated design process combining (i) proper wood selection, (ii) adequate sensor-based control strategies to ensure robot accuracy, and (iii) a robust design approach dealing with wood uncertainties. Based on the use of this integrated design process, a prototype of a wooden five-bar mechanism is designed and manufactured. Experimental results show that it is realistic to design a wooden robot with performance compatible with industry requirements in terms of stiffness (deformations lower than 400 μm for 20 N loads) and accuracy (repeatability lower than 60 μm), guaranteed in a workspace of 800 mm × 200 mm. This study provides a first step toward the eco-sustainable mechanical design of robots.

International audience; Ionization radiations are used to ensure food safety and quality. This irradiation process uses ions of beta or gamma rays to inactivate or destroy the food spoilage pests, microorganisms and their toxins without significantly increasing the temperature of the treated product. Meanwhile, various intrinsic and extrinsic factors are involved in determining the efficacy of ionization irradiation against these organisms. Therefore, the dose of radiations is recommended according to the type of irradiation, substrate and microorganisms. However, controversies are surrounding the use of irradiations in the food industry due to a negative perception of irradiations. This manuscript described the use of ionization radiations to control the foodborne biological hazards and increase shelf life. Firstly, the characteristics and mode of action of irradiations were discussed. Secondly, the role of extrinsic and intrinsic factors influencing the radioresistance of biological hazards were elaborated. This literature review also detailed the differential effects of irradiations on different microorganisms and pests having a role in food safety and deterioration. Finally, the regulatory status and the consumer values along with the controversies surrounding the use of ionization irradiations in the food sector were explained.

The forestry-wood sector is increasingly integrating the issues of circularity (resources, economy, environment), and the European hierarchy of waste treatment methods requires that complementary recovery routes for post-consumer waste are investigated. This work evaluates the technical, economic and environmental feasibility of closed-loop recycling of solid wood waste. The characterization of Class B wood waste (not pressure-treated) obtained from recycling centres indicates the potential of manufacturing glued laminated joinery planks. An industrial process for homogenizing the properties has been developed and tested, which includes: purging of metals, decontamination and cutting to lamellae, purging of defects, finger-jointing and laminating the slats to make laminated products. It is demonstrated that removing 2 mm from the surface permits the production of lamellae that have contamination levels lower than the limits used by the particleboard sector. The material yield of lamellae was optimized using a numerical model, then validated and completed by experimentation on the whole process at the pilot scale (a 30 % yield is obtained for products matching class J30 made of 20 mm × 60 mm lamellae). Mechanical tests showed properties similar to the reference values for classes C30 or GL24h and no influence of aging was observed. A life-cycle analysis has shown that this process is environmentally favourable with respect to landfilling, panel recycling, and medium-term energy recovery, and that it can be as economically favourable as energy generation.; La filière forêt-bois intègre de plus en plus les enjeux de circularité (ressources, économie, environnement), et la hiérarchie européenne des modes de traitement des déchets impose d’investiguer des voies de valorisation complémentaires pour les déchets post-consommateurs. Ces travaux évaluent la faisabilité technico-économique et environnementale du recyclage en boucle fermée des déchets en bois massif. La caractérisation des déchets faiblement adjuvantés sur plateformes de tri-broyage a conduit à cibler la fabrication de carrelets lamellés-collés de menuiserie. Un procédé industriel d’homogénéisation-conformation des propriétés a été développé et éprouvé, comprenant purge des métaux, décontamination et délignage en lamelles, purge des défauts, aboutage et contre-collage des lamelles en carrelets.Un surfaçage sur 2 mm s’est révélé efficace pour obtenir des contaminations inférieures aux seuils appliqués par le secteur des panneaux de particules. Le rendement matière du délignage a été optimisé à l’aide d’un modèle numérique d’usinage puis validé et complété par expérimentation à l’échelle pilote de l’ensemble du procédé (30 % pour des carrelets de classe d’aspect J30 issus de lamelles 20 mm x 60 mm). Des essais mécaniques ont montré des propriétés similaires aux valeurs de référence (aucune influence du vieillissement n’a pu être dégagée), et équivalentes pour les carrelets aux classes mécaniques C30 ou GL24h. Une analyse du cycle de vie a montré que ce procédé est environnementalement favorable vis-à-vis de l’enfouissement du recyclage en panneaux, et à moyen terme de la valorisation énergie et qu’il peut être aussi rentable économiquement qu’une valorisation énergie.

International audience

International audience; Bedding material is an important constituent of the animal production system. It is a key factor not only in the wellness and comfort but also for biosecurity measures applied for disease control and prevention programs. Animal production industry uses many types of bedding materials including, wood shavings, grass straws, paper, corn cobs, and rice husk, depending on the availability, price, hygroscopicity, animal comfort and environmental concerns. This review discusses the opportunities of using wood by-products like wood shavings, sawdust and chips in animal production, and their effect on health and welfare of animals and also on environment. Additionally, the microbial perspective of wood based beddings has been highlighted because generally it is considered as unhygienic material, however recent researches has shown the antimicrobial effects of this material, which can be utilized in production systems to counter the disease and lower the biological risk to health of animals, workers and environment.

Imagerie non destructive en microscopie confocale spectrale et microscopie multiphotonique :détection de contaminants du bois et analyse structurale d’un produit céréalier de cuisson. 7. Congrès biotech « Gen2Bio »

The nondestructive microscopic imaging of hygienically important microbes and contaminants on wood. Folle journée de l'imagerie nantaise

The forestry-wood sector is increasingly integrating the issues of circularity (resources, economy, environment), and the European hierarchy of waste treatment methods requires that complementary recovery routes for post-consumer waste are investigated. This work evaluates the technical, economic and environmental feasibility of closed-loop recycling of solid wood waste. The characterization of Class B wood waste (not pressure-treated) obtained from recycling centres indicates the potential of manufacturing glued laminated joinery planks. An industrial process for homogenizing the properties has been developed and tested, which includes: purging of metals, decontamination and cutting to lamellae, purging of defects, finger-jointing and laminating the slats to make laminated products. It is demonstrated that removing 2 mm from the surface permits the production of lamellae that have contamination levels lower than the limits used by the particleboard sector. The material yield of lamellae was optimized using a numerical model, then validated and completed by experimentation on the whole process at the pilot scale (a 30 % yield is obtained for products matching class J30 made of 20 mm × 60 mm lamellae). Mechanical tests showed properties similar to the reference values for classes C30 or GL24h and no influence of aging was observed. A life-cycle analysis has shown that this process is environmentally favourable with respect to landfilling, panel recycling, and medium-term energy recovery, and that it can be as economically favourable as energy generation., La filière forêt-bois intègre de plus en plus les enjeux de circularité (ressources, économie, environnement), et la hiérarchie européenne des modes de traitement des déchets impose d’investiguer des voies de valorisation complémentaires pour les déchets post-consommateurs. Ces travaux évaluent la faisabilité technico-économique et environnementale du recyclage en boucle fermée des déchets en bois massif. La caractérisation des déchets faiblement adjuvantés sur plateformes de tri-broyage a conduit à cibler la fabrication de carrelets lamellés-collés de menuiserie. Un procédé industriel d’homogénéisation-conformation des propriétés a été développé et éprouvé, comprenant purge des métaux, décontamination et délignage en lamelles, purge des défauts, aboutage et contre-collage des lamelles en carrelets.Un surfaçage sur 2 mm s’est révélé efficace pour obtenir des contaminations inférieures aux seuils appliqués par le secteur des panneaux de particules. Le rendement matière du délignage a été optimisé à l’aide d’un modèle numérique d’usinage puis validé et complété par expérimentation à l’échelle pilote de l’ensemble du procédé (30 % pour des carrelets de classe d’aspect J30 issus de lamelles 20 mm x 60 mm). Des essais mécaniques ont montré des propriétés similaires aux valeurs de référence (aucune influence du vieillissement n’a pu être dégagée), et équivalentes pour les carrelets aux classes mécaniques C30 ou GL24h. Une analyse du cycle de vie a montré que ce procédé est environnementalement favorable vis-à-vis de l’enfouissement du recyclage en panneaux, et à moyen terme de la valorisation énergie et qu’il peut être aussi rentable économiquement qu’une valorisation énergie.

International audience; The objective of the present study was to develop a simple and direct screening method to assess antimicrobial activities of wood material. Wood samples consisted of sawdust and wood discs cut in transversal (RT) and tangential (LT) direction, from four different wood species which were tested against four important bacteria in hospital hygiene. Area of inhibition was observed around sawdust embedded wells and wooden discs placed on agar. This study showed that wood disc diffusion can be used to easily and rapidly screen antimicrobial properties of untreated wood, while sawdust diffusion needs further work to do this.

International audience; Wood recycling is common practice in most countries. Currently, recovered wood is used for relatively low value uses including energy generation, particleboard manufacture, animal beddings and landscape uses. This paper gives an overview of two research projects that aim to generate high-value products from recovered wood and thereby encourage even higher rates of wood recycling. One project is concerned with the extraction of nano-crystalline cellulose from waste MDF and the other produces laminated beams from recovered wood.

Eco-design of robots has almost never be en explored in the past. This work investigates the potential of using bio-sourced materials, which have almost no environmental impact, instead of metals for robot design. Also, wood is one of the best candidates because of its interesting mechanical properties. However, wood performance / dimensions vary with the atmospheric conditions / external solicitations. Thus, it is challenging to design a stiff and accurate wooden industrial robot. Therefore, the objective of this paper is to describe a new design methodology leading to the design a wooden five-bar mechanism reliable in terms of accuracy and stiffness. The design optimization problem is solved in cascade. The first optimization process proposes to use a control-based design approach in order to compute the optimal primary geometric parameters of the robot (lengths of the links). This approach takes into account the sensor-based controller performance during the design phase. The second optimization process deals with the issue of the variability of the wood mechanical performance. It is based on a reliable topology optimization approach and allows for finding the shape of the robot links for which the impact of this variability in terms of deformation is minimized. Theoretical developments are described, solved and the obtained results allowed the prototyping of an industrial wooden five-bar mechanism.

International audience; Eco-design of robots is a field of research which has been rarely explored in the past. In order to considerably decrease the environmental impact of robot during the design phase, metal or carbon composite parts can be replaced by bio-sourced materials, such as wood. Indeed, wood has interesting mechanical properties, but its performance / dimensions will vary with the atmospheric conditions / external solicitations and with the conditions in which trees have grown. This paper deals with the design of a stiff and accurate wooden five-bar mechanism. First, a control-based design problem is formulated. This problem aims at finding the optimal parameters of the robot, taking into account the nature of the desired control (sensor-based control). Then, reliable topology optimization methodology is proposed, taking into account the variability of the wood performance and that will allow the definition of robot architectures (shape of the links) for which the impact of this variability in terms of deformation is minimal. Finally , the optimal design variables are given and are used for the realisation of industrial prototype of a wooden five-bar mechanism.

International audience; The design of wood-fiber based thermal insulating material with optimized properties and characteristics requires a good scientific knowledge of the latter. Currently, the technical, economic and ecological characteristics of a wood-fiber based composite mat are not well known. This article presents a methodology for the acquisition of expert knowledge so that the properties and characteristics can be modeled. The knowledge domain is multidisciplinary and it was delimited and decomposed into disciplines and domains of expertise. A panel of seven experts was constituted to cover the various disciplines and domains of expertise of the knowledge domain. Knowledge acquisition sessions, guided by the estimated importance and the availability of knowledge, were conducted using semi-structured interviews and the mapping of the existing causal relations between variables. A causal map was established to represent the causal knowledge of each of the experts and then, the established causal maps were assembled into a unique global causal map, which was subsequently validated by the experts. It contains the information necessary for formulating the properties and characteristics to be optimized, which were: thermal conductivity; thickness recovery of the material; the manufacturing cost and the product's environmental impact. Properties and characteristics are function of raw material type, their morphological properties and the manufacturing process variables. This methodology makes it possible to establish which objectives to optimize and which variables influence each objective. Consequently, the objective functions of the optimization problem can be clarified, specified and modeled.

International audience; This idea comes from the actual contest of climate change. The Climate Change Mitigation (CCM) has become a priority in Europe. To deal with this huge challenge, the European Council adopted new environmental targets for EU in 2008, the so-called « 20-20-20» targets, in which the first two targets are : o To reduce emissions of Greenhouse Gases y 20% by 2020, and o To increase energy efficiency to save 20% energy consumption by 2020 (40% and 27% by 2030) Fig. 1 Environmental impact of a Kuka KR 270 robot during is total life cycle (manufacturing + use during 12 years)/ Energy consumed during the use phase data form [1] • Design and control of 2 degrees-of-freedom wooden parallel robot (Five-bar Mechanism) • Repeatability < 0.5 mm • Deformation (under a load of 1 kg) < 0.5 mm • Workspace dimensions: 800 mm x 200 mm

National audience; La prédiction du comportement en service et de la durée de vie de matériaux composites renforcés de fibres naturelles est un challenge dès lors qu’ils sont soumis à des sollicitations multi-physiques complexes, tels que des chargements mécaniques et hydriques concomitants. La compréhension de la réponse du matériau à l’échelle locale peut nécessiter une description précise de leur microstructure.Ces travaux proposent une approche originale permettant de générer des microstructures virtuelles réalistes dans l’objectif de prédire numériquement le comportement hygroscopique de composites renforcés de fibres naturelles.

National audience; Le Groupement de Recherche en Sciences du bois (GDR3544 Sciences du Bois) a été créé en 2012 par le CNRS et renouvelé en 2016 pour 5 ans. La mission de ce groupement est : (1) de structurer la recherche sur le bois en France pour lui donner une visibilité nationale, (2) de contribuer au développement de la formation en sciences du bois et (3) de servir de relai aux réseaux internationaux de sciences du bois. Les 6èmes journées annuelles du GDR Bois ont été organisées à Nantes, à l’Ecole Supérieure du Bois (ESB) du 21 au 23 novembre 2017. Cette rencontre annuelle a rassemblé les membres de 40 organismes français et de 7 instituts / laboratoires étrangers. Elle a permis, au travers des exposés des conférenciers invités, d’évoquer les enjeux actuels de la filière forêt-bois autant que d’illustrer les diverses manières d’aborder l’étude du bois. Les participants ont pu échanger sur leurs travaux grâce aux présentations "flash" appuyées par des posters dont certains ont été primés par le biais d’un vote en ligne. Les actes de ces journées rassemblent les résumés des conférenciers invités (exposés) et ceux des contributions volontaires (posters). Les contributions des participants étrangers sont précisées, notamment celles issues des pays africains francophones. Les actes sont diffusés sur la plateforme HAL, sous forme de collection « Sciences du bois » qui est destinée à diffuser les travaux des membres du GDR Bois.

International audience; Abstract Thermochemical processes offer a feasible option for wood waste management and the recovery of a variety of useful chemicals. In this paper, hydroliquefaction with the use of catalysts was optimized to provide bio-oil from CCB-treated wood by reducing gaseous emissions of copper, chromium and boron (hazardous materials). In addition, the influence of \CCB\ salts, catalysts (Al2O3, Na2CO3, MgO and CaCO3) and residence time on the hydroliquefaction process was investigated. For this, hydroliquefaction of charcoal obtained by slow pyrolysis of CCB-treated wood was conducted under hydrogen pressure in presence of tetralin. The results showed that \CCB\ salts and catalysts increase the yield of bio-oil compared to hydroliquefaction of charcoal from untreated wood. It was also observed, that the use of catalysts improves the residence time during the process. Among the catalysts employed, Al2O3 appears to be the most effective. Furthermore Na2CO3 promotes the formation of gaseous species particularly CH4. Analyses of hazardous materials in charcoal residue (coke) illustrate their transfer to the bio-oil with the increase of bio-oil yield and residence time except when Al2O3 was using. The bio-oil obtained contains aromatic compounds.

International audience

International audience; Contexte Fig. 1. Impact environnemental d'un robot Kuka KR 270 sur toute sa durée de vie (fabrication + 12 ans de service) / Consommation énergétique durant une phase d'utilisation de 12 ans. Objectifs L'industrie européenne est engagée dans un processus de robotisation afin de rester compétitive. Cependant, il est méconnu que l'utilisation des robots (sans même considérer le procédé industriel pour lequel ils seront utilisés) impacte considérablement l'environnement (Fig. 1). On estime l'impact de la fabrication (seulement) du stock mondial de robots industriels, à 11 millions de tonnes en équivalent CO 2 rejetées dans l'atmosphère (équivalent à 36 millions de camions parcourant la distance Nantes-Paris). Ceci est grandement dû aux matériaux métalliques, voire composites de carbone, dont la manufacture est extrêmement polluante (même s'ils sont recyclés). Montrer qu'il est possible de réduire considérablement l'impact environnemental des robots industriels (2 ddl, Fig. 2) en remplaçant la grande majorité des matériaux métalliques/composites de carbone par des matériaux bio-sourcés à faible impact écologique, tout en garantissant la fiabilité du robot en termes de durée de vie et de performances mécaniques (critères : répétabilité < 0,5 mm et déformation sous charge de 1 kg inférieure à 0,5 mm) même si les propriétés / dimensions du bois varient. Premiers résultats Fig. 2. Robot plan à 2 ddl qui sert de base à l'étude Méthode Seule la partie matériau est abordée ici (une partie du projet concerne des aspects spécifiques à la robotique (capteurs extéroceptifs, algorithme de conception robuste, commande). Ici la méthode consiste à : • Développer un modèle mécanique numérique du robot, fiable, précis et rapide, qui sera utilisé par les algorithmes d'optimisation de la conception du robot. • Caractériser précisément les caractéristiques mécaniques du bois retenu (on commence par étudier le bois acétylé, pour sa stabilité dimensionnelle). • Réaliser un prototype pour valider le modèle numérique. Rigidité Deux méthodes d'essais, l'une destructive (Fig. 3), l'autre non (Fig. 4). Les dimensions des éprouvettes sont de l'ordre de grandeur de celles des bras du robot : 30 x 30 x 350 mm. Essais préliminaires sur Douglas, résultats très éloignés entre les 2 méthodes • Flexion 4 points (15 éprouvettes) : E m = 13850 MPa CV = 28 % • Porte-à-faux (5 éprouvettes) : E m = 9440 MPa CV = 6 % Fig. 3. Flexion 4 points (EN 408) Fig. 4. Flexion porte-à-faux

Background. Enteric diseases are an important concern to the poultry industry and coccidiosis is imposing a significant economic burden worldwide.Objectives. The main goal of the present study was to investigate the prevalence of coccidiosis in free-range chicken in Sidi Thabet, northeast Tunisia.Methods. Six hundred and thirty free-range chickens along with fecal samples were collected from 15 flocks in this region and two hundred chickens were found positive for oocysts ofEimeriaspp. Intestines were dissected and examined for macroscopic lesions. The mucosa of small intestine and the caeca were examined for the presence and identification of parasitic forms using parasitology methods. The mean lesion scores were usually low (2+) were attributed mainly to the caeca.Results. The overall rate of coccidiosis was 31.8%:E.tenella(61.5%),E.maxima(12%), andE.acervulina(1.5%). MixedEimeriaspecies infection was observed with overall prevalence 26.5%. There was a statistically significant difference (P<0.05) among infection rates, age groups, season, diarrhea, and type of chicken.Conclusion. This is the first report of coccidiosis rate in free-range chicken in this region. Further additional studies are needed to develop better preventive measures against coccidiosis in the country.

International audience

For ten years, numerous studies have been carried out in France on the properties of poplar wood, both by research institutes, technical centers, and in close collaboration with industry. Thus, the wood of 23 cultivars, representing the most cultivated poplars in France, has been characterized from a large and structured sample of mature trees (multi-sites and multi-trees per site). Characterization focused on the general properties of logs and wood, as well as major industrial uses of wood. The mechanical characteristics of the sawings and their drying behavior, suitability for peeling and characterization of the plywood, pulping and the shape of the fibers have been described. The results are presented in two publications widely available*, either with a “cultivar” entry describing all the characteristics measured on a cultivar or with an entry “characteristics of wood” where performances of the different cultivars are compared between them. Furthermore the GIS Peuplier (French scientific consortium) studied the properties of 55 clones of poplar (P. deltoides and P. x canadensis) from samples of juvenile wood (2 and 4 years) and mature wood (21-27 years). Correlations between variables were investigated for different ages of wood. The best correlations with adult performances concerned basic density and fiber width, and to a lesser extent, shrinkage of the wood samples measured at 4-yrs. These results should enable breeders to include these wood properties predictors in the first steps of their breeding program.

Une méthodologie a été développée ici pour l’acquisition, la représentation et le transfert (transmission, assimilation et utilisation) de connaissances scientifiques vers les industriels. L’acquisition intègre la collecte, la modélisation et la structuration des connaissances selon un format scientifique. La représentation est basée sur une carte conceptuelle canonique et un format de graphe d'influences. Les connaissances acquises et représentées sont implémentées dans un livre de connaissances électronique. Deux livres sur le biscuit satiété et les produits récupérés à base de bois ont été implémentés et testés suivant trois critères : la désorientation, la charge cognitive et la compréhension des connaissances de l'utilisateur au cours de l’utilisation.

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Since several decades, quite a lot of structures have been monitored to analyze their displacement during the works or during the service-life. This paper presents a methodology for identifying soil characteristics from data structural health monitoring, applying for to a wharf with instrumented tierods. Loading and soil parameters are modelled as random variables. The modelling is performed though a meta-model fitted on a numerical database obtained from direct simulations on a complex finite element model under PLAXIS software: a quadratic Response Surface Model (QRS) is considered.

This paper proposes an extension of random field theory for modeling spatial variability of deteriorationprocesses, herein, the expansion Karhunen-Loève is used. The studied structure is discretized intoseveral elements and system reliability is used to evaluate the probability of failure. Some considerations foroptimal discretization will be also discussed in the paper. The series system methodology will be applied tothe reliability analysis of a RC bridge girder placed in a chloride-contaminated environment. The results ofthis study illustrate the importance of including spatial variability in the problem.

The use of scientific knowledge on waste wood management is the main factor that facilitates the responsible use of recovered wood respecting the environment. Nowadays, numerous scientific results are generated and published by universities and research institutions; but small quantities are exploited by nonscientific people. This problem is due to the difficulty of transfer and assimilation of this knowledge in its current representation. In this paper, we propose a new structure and representation of both type of scientific knowledge (declarative and procedural) to facilitate its transfer to non-scientific people through a hypertext electronic knowledge-book. The declarative scientific knowledge has been represented by concept maps and hierarchically structured through semantic relationships and the procedural scientific knowledge has been represented by technical sheets.

Différents secteurs industriels tels la plasturgie, la métallurgie se sont souciés de réduire l’impact environnemental de leurs matériaux en développant de véritables filières de recyclage. L’industrie du bois possède un matériau qui n’épuise pas les ressources fossiles mais ne dispose pas d'une filière de recyclage du niveau de matériau comme l'aluminium ou les plastiques. Pourtant depuis plusieurs années, la prise en compte des enjeux environnementaux n’a de cesse de croître et conduit à considérer davantage le cycle de vie des produits plutôt que le produit seul. Ce type d’analyse implique d’avoir des solutions responsables pour les produits à base de bois en fin de vie si l’on veut pouvoir conserver les avantages du matériau bois. Notre objectif est donc d’établir une stratégie pour déterminer des choix éclairés de recyclage des produits composites à base de bois. Il est d'ailleurs davantage question de valorisation quelle soit matière ou énergétique de ces produits en fin de vie qu'uniquement de recyclage. Le développement d'un outil informatique de type système expert doit nous permettre, sur la base de critères responsables (réglementaires, environnementaux) et pertinents (techniques, économiques), d'aboutir à des solutions de valorisation pour les différents produits en fin de vie.

La conception par optimisation multi-objectifs implique l'optimisation de plusieurs objectifs contradictoires simultanément. Cette contradiction traduit le fait qu'il n'existe pas de solution optimale au regard des objectifs, mais des compromis optimaux. C'est la prise en compte de cette contradiction via la volonté de minimiser chacune des fonctions objectifs qui introduit la notion de compromis et de contraintes. Les contraintes, des spécifications du problème, limitent les espaces des paramètres et ceux des fonctions objectif. Un compromis sera dit optimal si toute amélioration d'un objectif induit la dégradation d'un autre objectif. Les compromis optimaux se situent sur un front dit de Pareto. La présence d'un front de Pareto, un ensemble de solutions optimales non équivalentes, permet de choisir une solution optimale par rapport à des critères économiques ou fonctionnels, qui sont externes au problème d'optimisation. L'optimisation par essaim particulaire (OEP), est une technique évolutionnaire permettant de parcourir efficacement l'espace de solutions d'une fonction objectif et de trouver son minimum, et cela pour une grande diversité de fonctions objectifs : équations continues ou discrètes, règles de connaissances qualitatives et algorithmes. Ici nous utilisons l'OEP pour l'optimisation multi-objectifs d’un platelage en bois polymère. L’optimisation porte sur le fluage et la résistance à l’eau du platelage et sur un indicateur d'épuisement des ressources abiotiques. Les variables de conception sont principalement des variables de production des matières premières, d’incorporation d’un biopolymère, de contrôle de la granulométrie du bois ou de sa modification chimique ou thermique. Les fonctions objectifs sont des équations et un algorithme intégrant des données discrètes. Des produits, issus des solutions Pareto-optimales inédites par remplacement du plastique de synthèse par un dérivé de l'amidon de maïs, ont été fabriqués par le partenaire industriel. Les tests mécaniques sont en cours.

International audience; The design by multi-objectives optimization implies the optimization of several contradictory objectives simultaneously. In fact there is no optimal solution for one particular objective if the other objectives are considered, but the aim is to simultaneously minimize all the objectives in order to reach an optimal compromise. Optimum is reached if any improvement of one objective induces the degradation of one other. Such an optimum is located on a front called Pareto front. The Pareto front, a set of optimal solutions that are not equivalent, allows us to choose an optimal solution with criteria external to optimization process (economic or functional). In this study, a multi-objective particle swarm optimization (a metaheuristic) algorithm has been used to optimize a wood plastic composite for decking application. This metaheuristic, based on evolutionary techniques, applies to a great diversity of functions objectives: continuous or discrete equations, qualitative knowledge rules and algorithms. The design variables are mainly variables of raw materials production, and the incorporation of a biopolymer, the control of timber particle sizes and chemical or thermal timber changes. The objective functions are equations and an algorithm integrating discrete data in the modelling of creep behavior, water resistance and fossil resources depletion.

National audience

National audience; The analysis of the moisture content variations along Douglas fir increment cores, fresh cut logs and peeled veneers allowed to confirm the low level of moisture content inside Douglas fir heartwood. Whatever the tree and the inside ring location may be, the heartwood moisture content is about 30% vs. 80 to 150% for sapwood. Several hygrothermic treatments (conventional boiling, hot/cold baths, vacuum/pressure cycles) have been applied to 12 cm long bolts in view to measure the moisture content increasing. Only the treatments involving vacuum and pressure appeared efficient. The heartwood moisture content after such treatments ranged from 50% to 150%. The higher M.C. were obtained inside earlywood.; L'analyse de la répartition de l'humidité sur des carottes de sondage, des planches fraîchement sciées et des placages déroulés de Douglas ont permis de confirmer la faible teneur en eau du duramen de cette essence. Quels que soient l'arbre et la position radiale dans le cerne, l'humidité est de l'ordre de 30 % dans le duramen alors qu'elle atteint 80 à 150 % dans l'aubier. La reprise d'humidité a ensuite été analysée sur des billons de 12 cm de long soumis à différents traitements hygrothermiques (bouillottage conventionnel, bain chaud/froid, cycles vide/pression). Seuls les traitements à base de vide et pression s'avèrent efficaces. L'humidité du duramen varie après traitement entre 50 % et 150 %, les plus fortes valeurs étant obtenues dans le bois initial.

L'analyse de la répartition de l'humidité sur des carottes de sondage, des planches fraîchement sciées et des placages déroulés de Douglas ont permis de confirmer la faible teneur en eau du duramen de cette essence. Quels que soient l'arbre et la position radiale dans le cerne, l'humidité est de l'ordre de 30 % dans le duramen alors qu'elle atteint 80 à 150 % dans l'aubier. La reprise d'humidité a ensuite été analysée sur des billons de 12 cm de long soumis à différents traitements hygrothermiques (bouillottage conventionnel, bain chaud/froid, cycles vide/pression). Seuls les traitements à base de vide et pression s'avèrent efficaces. L'humidité du duramen varie après traitement entre 50 % et 150 %, les plus fortes valeurs étant obtenues dans le bois initial., The analysis of the moisture content variations along Douglas fir increment cores, fresh cut logs and peeled veneers allowed to confirm the low level of moisture content inside Douglas fir heartwood. Whatever the tree and the inside ring location may be, the heartwood moisture content is about 30% vs. 80 to 150% for sapwood. Several hygrothermic treatments (conventional boiling, hot/cold baths, vacuum/pressure cycles) have been applied to 12 cm long bolts in view to measure the moisture content increasing. Only the treatments involving vacuum and pressure appeared efficient. The heartwood moisture content after such treatments ranged from 50% to 150%. The higher M.C. were obtained inside earlywood.

*INRA, centre de Nancy Diffusion du document : INRA, centre de Nancy

International audience; To ensure optimal performance of parallel robots, a rigorous design process has to be implemented. However, this may not be enough due to the presence of complex phenomena such as vibration, clearance, deformation, hard to model and thus to control, but considerably impacting the robot performance. An efficient approach to improve performance via bypassing the modeling issues is the use of exteroceptive sensors to estimate the end-effector pose. Any external observation, however, impacts the robot performance. It is thus necessary to optimize the robot design with respect to (usual) mechanical performance criteria, but also with respect to performance indices coming from the definition of the sensor-based controller. Thus it is necessary to achieve control-based design. In this work, a five-bar mechanism is optimized using a classical design methodology. The robot is then compared with other designs which are the result of a new methodology, taking into account the nature of the desired control scheme through the incorporation of control-based performance indices into the optimization process. Though the latter designs may have a bigger footprint, they will prove to exhibit better accuracy performance when controlled using exteroceptive sensors.

International audience; Eco-design of industrial robots is a field of research which has been rarely explored in the past. In order to considerably decrease the environmental impact of robot during the design phase, metal or carbon composite parts can be replaced by bio-sourced materials, such as wood. Indeed, wood has interesting mechanical properties, but its performance / dimensions will vary with the atmospheric conditions / external solicitations and with the conditions in which trees have grown. In order to be able to design a stiff industrial robot, robust design approaches must be used. These approaches must be fed with elastostatic models that are able to predict the variability in the robot deformations due to the variability of the wood mechanical properties. In this paper, we develop an elastostatic model for a wooden parallel robot which is able to cope with the variations of the wood mechanical properties. The prediction of this model in terms of deformations are compared with experimental measurements made on a wooden parallel robot mockup. Results show that there is a good correlation between the measurement displacements and the computed ones.