WorldCat Identities

LERMAB - Laboratoire d'Études et de Recherche sur le MAtériau Bois - EA 4370

Overview
Works: 75 works in 77 publications in 2 languages and 77 library holdings
Roles: Other, Degree grantor
Publication Timeline
.
Most widely held works by LERMAB - Laboratoire d'Études et de Recherche sur le MAtériau Bois - EA 4370
Étude de l'association d'une colonne d'absorption à un séchoir convectif à basse température : influence de l'absorbeur sur la cinétique et la qualité du chauffage by Laurent Chrusciel( Book )

2 editions published in 1998 in French and held by 2 WorldCat member libraries worldwide

Ce mémoire rend compte de travaux de recherches conduits sur une installation constituée d'un séchoir convectif à bois basse température associé à une colonne d'absorption dont la fonction est de déshumidifier l'air de séchage sur une boucle de recirculation du séchoir. L'absorbeur est de type venturi et l'absorbant est un liquide organique, le triéthylène glycol (teg). L'objectif de l'étude est d'évaluer les performances de l'installation à travers les deux paramètres que sont la cinétique de séchage et la qualité du bois sèche. Un modèle macroscopique simple, représentant les échanges de matière entre le bois et l'air pendant le séchage, a ainsi été développé. Il est caracterisé par un coefficient global de transfert de matière dont les variations en fonction des principaux paramètres opératoires ont été précisées. Ce coefficient est l'outil de mesure de la cinétique moyenne de séchage d'un lot de bois au cours d'un cycle complet. Il permet ainsi d'évaluer l'influence du débit de TEG, du débit d'air traversant l'absorbeur et de la température de l'air sur le fonctionnement de l'installation. Dans le domaine de fonctionnement considéré, l'utilisation de l'absorbeur améliore la cinétique de séchage d'environ 65% : cette performance est peu influencée par les trois paramètres étudiés. La qualité du bois sèche est estimée par la mesure des défauts de séchage à savoir le nombre et la dimension des fissures ainsi que les déformations (flêches de face et de front). Des cycles de séchage ont été conduits sur du hêtre et du sapin. Les résultats montrent que l'utilisation de l'absorbeur est pénalisante sur la qualité du bois sèche. Toutefois, l'accélération de la cinétique de séchage ne se traduit pas par une augmentation du même ordre de grandeur des défauts. En particulier lors du séchage du sapin, la qualité du bois est peu affectée par l'utilisation de l'absorbeur. Enfin, la quantité totale de produits organiques présente dans l'air de séchage est évaluée à l'aide d'un détecteur à ionisation de flamme. Les essais réalisés montrent que la concentration en composés organiques de l'air de séchage est en moyenne divisée par un facteur 7 lorsque l'absorbeur fonctionne. La synthèse de l'ensemble des résultats conduit à penser que l'installation étudiée semble mieux adaptée au séchage des essences résineuses
Développement de matériaux composites fibreux hautes perfomances à matrice bio-sourcée by Alix Sauget( Book )

2 editions published in 2014 in French and held by 2 WorldCat member libraries worldwide

La mutation de nos activités industrielles vers le développement durable est l'un des plus gros enjeux humains du 21ème siècle. L'utilisation de la biomasse dans divers domaines tels que l'énergie, la construction et les matériaux est une réponse face à la raréfaction des ressources fossiles et face aux risques écologiques. Les objectifs de cette thèse sont de créer de nouveaux matériaux les plus bio-sourcés possibles et d'optimiser les propriétés de ces matériaux en vue d'une éventuelle utilisation industrielle. Les travaux présentés ici traitent de la fabrication de matériaux composites à renforts de fibres naturelles, ayant pour matrice des résines bio-sourcées. Les ressources végétales principalement étudiées ici sont les tannins, utilisés pour la réalisation de : - Composites à matrice tannin - hexamine - Composites à matrice tannin - résorcine - aldéhyde Les tannins végétaux ont également été étudiés pour la conception de bio-plastiques tannin - alcool furfurylique pouvant être appliqués à la fabrication de composites. Les panneaux composites ont été réalisés en laboratoire et analysés mécaniquement en se basant sur des méthodes normatives européennes. Les résines ont également été caractérisées à l'aide de diverses techniques telles que l'analyse thermomécanique (TMA) ou la spectroscopie de masse MALDI-ToF. Au final, ces travaux ont permis de réaliser des matériaux composites hautement bio-sourcés, aux propriétés homogènes et reproductibles satisfaisant en outre les exigences d'emploi de plusieurs normes européennes
Condensed tannins extraction from grape pomace : characterization and utilization as wood adhesives for wood particleboard by Ping Lan( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

The extraction of condensed tannins from grape pomace was examined using water medium in the presence of different bases as catalyst (NaOH, Na2CO3, NaHCO3 and Na2SO3). Two different extraction processes and the influence of 4 parameters (i.e., temperature, reaction time, chemical reagents and concentration of the chemical reagents) on the tannin extracts yields and properties were studied. The tannin fractions were characterized by Fourier transform-infrared spectroscopy, thermogravimetric analysis, carbon nuclear magnetic resonance spectroscopy and matrix assisted laser desorption ionization time of flight mass spectrometry ( MALDI-TOF ). It was demonstrated that it is possible to extract reactive tannins from grape pomace in basic medium. The tannin extracts obtained by precipitation in acidic conditions display a high phenolic content (Stiasny number higher 95%) but low water solubility and low reactivity toward formaldehyde because of the formation of catechinic acid phlobatannins during the acidification step. The tannins extracts obtained by lyophilization of the liquid, despite of their lower phenolic contents, displayed promising properties for adhesive applications. The optimum temperature of the extraction process was 100 °C, reaction time was 120 min; the best concentration of reagent was 10% (w/w). It was also shown that addition of sulphite ions during the extraction step improved the process :y the introduction of a sulfonic group through sulfitation increased both tannin solubility and reactivity as a result from the opening of the heterocyclic ring during extraction The structure of grape pomace sulfited tannin extracts did not present noticeable discrepancy exception of the ratio of the opening pyran ring which was different as a function of the catalyst used. The opening of pyran ring during the tannins extraction seem to be more important by using Na2CO3 and NaHCO3 than when using NaOH. The FT-IR bands assigned to aromatic ring vibration and carbonyl groups were stronger and no bands attributed to sulfited groups were tested detected in acidified tannins compared to lyophilized tannins. The TG2 results showed that the weight lost of these tannin extracts mainly composed of two steps. The first step starts from room temperature to 200 °C. It is attributed to the mass lost of water and some easy-degraded small low molecules. The secondly steps which is the mainly degradation step of tannin extract samples from 200 to 400 °C. The results from 13C-NMR showed that condensed tannin extracts from grape pomace were consistent with dominant procyanidin units with a minor amount of prodelphinidin units that are linked together by a C4-C8 bond. Relatively low carbonhydrate and high catechinc acid content was observed in acidified tannins compared to lyophilized tannins. It was shown by MADI-TOF experiments that grape pomace tannin extracts are mainly composed of flavoinoid oligomers up to 6 repeating units in lyophilized tannins and 10 repeating units in acidified tannins respectively, with dominant procyanidin units. A small proportion of substitution with glucose and gallic acid was detected in procyanidin units of polyflavonoid oligomers. The degree of polymerization of acidified tannins is higher than lyophilized tannins. Two different formulations (nonfortified tannin adhesive and fortified with addition of 20% of polymeric 4, 4'-diphenyl methane diisocyanate (p-MDI)) were used to press one layer wood particle board. It was shown that the nature of the extraction reagent (NaOH, Na2CO3 or NaHCO3) greatly impacts the properties of the resins and the mechanical properties of the panel internal bonding strengths. The particleboards bonded by the tannins extracted using Na2CO3 as catalyst give the best performance and were good enough to pass relevant international standard specifications for interior grade panels. Formaldehyde emission of these panels was below the European Norm requirements (<= 6.5 mg/ 100g panel)
Biocomposites : composites de hautes technologies en renfort de fibres naturelles et matrice de résines naturelles by Raphaël Kueny( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

This thesis was carried out within the LERMAB and the CETELOR and about the development of more than 98% biobased composites materials. Bast fibre type flax, hemp, kenaf and jute were selected, characterized chemically and physically. Nonwovens reinforcements are defined here as a superposition of cohesive webs products by pneumatic carding and consolidation by needling. The process we have chosen during this work allowed us to understand and to highlight the importance of the quality of the fibers on the mechanical and structural properties of the materials developed. Reinforcements made initially in a weight range from 200 to 800 g/m² in single, double or triple thicknesses have then been optimized to preserve the mechanical properties of the fibers and allow good accessibility of the impregnating resin. To limit the factors of complications, the process parameters have been limited for all fibers and composites. Fibers have been used singly or in mixtures, and impregnated by a matrix of natural tannin from mimosa and hexamine (as a hardener) or by synthetic resin of epoxy. Biocomposites with a rate of fibre mass over 50%, and density between 0.9 and 1.2 were obtained. Elasticity Modulus reach 6 GPa flexural and tensile. For strenght, averages reach 42 MPa and 75MPa respectively in tensile and bending
Caractérisation et modélisation numérique des poutres en Bois Massif Reconstitué (BMR) réalisées avec une essence locale feuillue by Van Dang Tran( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Nowadays, adhesively reconstituted products made of beech timber appear to be of increasing interest for structural purposes due to its high strength/stiffness properties as compared to the most soft-wood species. Furthermore, beech timber is not recognized by most standards for structural uses and restricted to service class 1 and only the furniture, interior joinery and do-it-yourself sectors are still the major users. The French market shows great increasing imports of adhesively reconstituted structural products from Germany and Austria. Moreover, the use of local species, like beech, for the production of reconstituted structural elements could be better for the carbon balance, since it reduces import transportation. However, despite the high mechanical performance of beech timber, adhesively reconstituted products need to meet some requirements, such as the performance of finger-joints. This thesis presents experimental and numerical approaches to deal with the mechanical behaviour of adhesively reconstituted beech beams, for structural purposes. Two-layer and three-layer beams with or without finger-joints have been considered and successfully studied. In addition, a parametrical study has been undertaken to study the influence of several parameters on the mechanical resistance of finger-joints. We, finally, proposed an optimization of the finger-jointing geometry in order to increase the resistance of finger-joints
Développement de stratifiés de papiers imprégnés à base de résine de tannin de mimosa et d'alcool furfurylique by Ummi Hani Binti Abdullah( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Resin impregnated papers have been widely used in manufacturing laminates for wood panels. Generally, paper impregnation involves melamine formaldehyde, melamine urea formaldehyde and urea formaldehyde resin. However, these materials are expensive when used in high quantity and derived from non renewable resources. Therefore, in this work we prepared tannin furanic resin impregnated paper to replace melamine formaldehyde and urea formaldehyde in the paper impregnation. Tannin furanic resin composed of two main natural materials: a) mimosa tannins which is non-toxic, environmentally friendly and relatively inexpensive to substitute the synthetic resin and b) furfuryl alcohol obtained by catalytic reduction of furfural, a natural compound obtained by the hydrolysis of sugars derived from agricultural waste. Tannins are naturally occurring phenolic compounds extracted from the bark trees that have been used industrially for many years as wood panel adhesives but no distance work have been done to study their potential in paper laminates. In this work, we studied: 1) The gel time between mimosa and pine tannin with furfuryl alcohol without the addition of formaldehyde from pH 1 to pH 11 2) The MALDI-TOF and NMR of mimosa tannin with furfuryl alcohol 3) The surface quality of the plywood overlaid with mimosa tannin- furfuryl alcohol resin 4) 10-ply high pressure laminates (HPL) were prepared with mimosa tannin- furfuryl alcohol resin. The surface quality of the HPL and the mechanical properties of plywood overlaid with this HPL were examined. 5) 10-ply high pressure laminates were prepared with mimosa tannin- furfuryl alcohol resin in the acid condition. The surface quality of the prepared HPL were compared with PF
Développement de matériaux composites écologiques à base de résines de tannins et de renforts de fibres végétales by Arnaud Nicollin( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Tannins are plant chemicals that show a good reactivity and so they can replace similar products from oil chemistry. This is the case for condensed tannins that have reactivity mechanism similar to that of the phenol. They have been used for several years in wood glues, but no in depth study have been carried out on their potential in composite manufacturing. The work presented here can be split into three projects aiming at the development of composite materials of high performances using both tannin based resins and natural fibers reinforcement. 1. The first project aims to develop a thermosetting composite based on the same tannin/hexamine resin already as glue for particleboards. A previous study shown that it was feasible but numerous problems needed to be solved in order to obtain a reliable and competitive manufacturing process. 2. The goal of the second project is the study and the development of composites which matrix is based on a copolymer of tannin and furfuryl alcohol. Furanic resins show good properties and their capability to react with phenolic compounds makes them potential candidates for the manufacturing of high performances composites. 3. The last project's objective is the production of acetylated tannins by using similar methods than that used for lignin, to check if they present the same thermoplastic behavior and if yes, to test them in composite manufacturing
Étude des voies de valorisation des déchets ménagers au Bénin : cas de la ville d'Abomey-Calavi by Melhyas Kple( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Generaly in West Africa, the waste management is a priority problem mainly for the cities which welcome a growing population. It is the case of the city of Abomey-Calavi, that has no organized system of waste management. To allow an optimized management of waste, an overall policy based on tangible and demonstrated elements must be implemented. It is so essential to analyze the problem and its characteristics, to test various envisaged solutions, and to optimize the viable systems. The objective of this study is to provied solutions for the waste treatment of Abomey-Calavi. It is so a question of studying the problem, since the characterization of waste until the proposal of appropriate solutions and the conditions of their implementation. The methods tested in this study are based on thermochemical ways (Pyrolysis, Combustion and Gasification). The heterogeneous nature of waste does not allow their study in laboratory (more expensive and not representative). Thus, a model waste (MW: wood 88 %, Cardboard 7 %; Plastic 5 %) was established and based on the typological characterization of the waste of the city and the chemical assumptions. The study of the pyrolysis was realized in two parts. Slow pyrolysis in TGA and fast pyrolysis. TGA shows that the fast pyrolysis of the model waste can be made only at temperatures above 500°C. In the continuity of the results obtained in pyrolysis, a study of air gasification was made on the wood and the model waste at temperature of 800°C in a fluidized bed reactor. The tests allowed to observe that the results on these two types of fuels are very close. A simple model for the production of gas, condensable and of char during the gasification in fluidized bed was developed.The study of the combustion of MW in the boiler of LERMAB shows that the combustion is better when it is made in a reactor of high power. Compared with the results obtained on the wood, the combustion of the combustible mixture (MW) in the boiler does not present negative effects. These results seem very interesting for the choice of a better way of thermochemical treatment of the waste of the city of Abomey-Calavi. Finally, a waste management chain of HSW of the city of Abomey-Calavi is proposed in three parts and based on a mixed biological - thermochemical process preceded by the sorting
Développement de trois différents types de matériaux innovants à base de tannins by Marion Thébault( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Tannins are chemical extracts which represent a natural alternative to chemicals as phenol or resorcinol which are from oil resources. They are already used industrially for the synthesis of adhesives used for the manufacture of wood-based products such as particleboards and plywood, but generally always used with formaldehyde as a hardener to improve their mechanical strengths. The first products developed in this thesis are adhesive resins for the manufacture of particleboards, synthesized from Radiata Pine tannins and less hazardous aldehydes obtained by reacting sunflower oil with ozone then with a reducing agent. The study has focus first on the conditions of the ozonolysis, whose parameters are numerous, and the analysis of the oils obtained, then on the synthesis of resins with solutions of tannins. Some of these resins have been used to manufacture particleboards that have been tested in dry internal bond strength. Then the subject has been oriented toward the development of rigid tannin/furanic-based foams as part of an industrial multi-material project. Several formulations have been tested to achieve the objectives of a specification, whose first purpose is to obtain foam panels homogeneous, low in density and with good mechanical properties. The innovation has been to make these foams in a particleboard press. Finally, a new route to manufacture tannin-based polyurethane polymers has been tested by using less hazardous chemicals in replacement of isocyanates, conventionally used in the industry. The synthesis is made by a first carbonatation step of tannins hydroxyl groups and then by a reaction with hexamethylenediamine. Spectrometric analyzes have shown that the products obtained do have urethane linkages. The study led to the exploration of the use of tannins reacted with ammonia to replace hexamethylenediamine to obtain new "non isocynates" polyurethanes with more bio-based and environment-friendly chemicals
Compréhension des mécanismes de déstabilisation des substances dissoutes et colloïdales contenues dans les mélanges de pâtes à papier recyclée et mécanique : proposition de solutions pour limiter le nombre de casses stickies by Cédric Cael( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

Lors de la fabrication de pâtes à papier, désencrée et mécanique, des substances dissoutes et colloïdales sont libérées dans les eaux du procédé. Celles-ci peuvent dans certaines conditions se déstabiliser et former des agglomérats collants, appelés « stickies ». La présence de ces agglomérats engendre des perturbations lors de la formation de la feuille sur la machine à papier, notamment des casses. Les travaux présentés dans cette thèse montrent l'impact du taux d'extractibles, obtenue de manière automatisée grâce à la mise en place d'un capteur, sur l'apparition des casses d'origine stickies. D'autre part, le vieillissement de la pâte désencrée a été identifié comme une des causes des modifications physico-chimiques de la pâte, conduisant à la déstabilisation des substances dissoutes et colloïdales des pâtes mécanique et désencrée lors la phase de mélange. Enfin, des solutions ont été proposées afin de limiter le phénomène d'agglomérations des substances dissoutes et colloïdales et par conséquent de diminuer le nombre de casses sur la machine
Valorization of beech wood through development of innovative and environmentally friendly chemical modification treatments by Mahdi Mubarok( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

In this study, improvement of physical and biological durability properties of European beech (Fagus sylvatica) has been performed through different bulking impregnation treatments. The first modification was based on the impregnation of vinylic derivatives of glycerol or polyglycerol as additive followed with different thermal modification conditions in the opened system (OHT) or in the closed system (HPS). The second modification was based on the in-situ polyesterification of sorbitol and citric acid at different concentrations and curing temperatures in the opened system. Various physical, chemical, mechanical, and biological durability properties of the modified woods were evaluated, including certain properties during modification. The results have disclosed that certain treatments can improve significantly physical and biological durability properties of wood against decay (white rot, brown rot, and soft rot fungi) and termites attacks in comparison to untreated wood or thermally modified woods
Effet de la variabilité intra et interspécifique du bois sur les procédés de traitement thermique by Joël Hamada( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

In the context of sustainable development which has seen the introduction of the biocides directive BPD 98/8/CE in the EU, innovative wood preservation practices such as Heat Treatment (HT) become relevant. Wood HT, also termed wood thermal modification, is a physical modification technology by which wood is heated at around 200 °C in an inert atmosphere. The main purpose of the treatment is to improve the biological durability and dimensional stability of wood. Current studies on thermally modified wood (TMW) quality are focusing on treated material, on treatment conditions or on species effect on the end-product characteristics. Relatively little is known about the effect of intrinsic wood properties on its thermal modification. As wood properties vary especially under the influence of human activities through sylviculture, this thesis studied the effect of European oak and silver fir wood density and chemical composition on their thermal modification kinetic. An X rays computed tomography (CT) and densitometer were used to characterize wood samples. Boards were heat-treated by conduction under vacuum using a pilot furnace, whereas sawdust samples underwent thermo-gravimetric analysis under nitrogen. The analysis allowed finding intra- and interspecific variations, especially within growth rings and along radial direction (from pith to bark). Forest management impacted heat modification kinetic of the studied samples, especially in silver fir where fast grown wood was more sensitive to treatment. The finding will be used as additional information to the wood industry which will account for homogeneity of loadings destined to heat treatment
Contribution à la modélisation et à l'optimisation de systèmes énergétiques multi-sources et multi-charges by Mohamed Mladjao Mouhammad Al Anfaf( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

La demande énergétique mondiale continue d'augmenter. Les prix des énergies fossiles sont instables et incertains. La libéralisation du marché électrique et une conscience environnementale des acteurs mondiaux sont des leviers au développement des énergies renouvelables. Ces dernières se développent à un rythme rapide dans le monde. Elles ont atteint une maturité technique qui leur permet de devenir un segment important de l'industrie de l'énergie. Leur insertion dans le mix énergétique pose de nouveaux défis par rapport aux sources d'énergie traditionnelles. Avec un potentiel abondant encore sous-exploité, le photovoltaïque et l'énergie éolienne sont avantageux sur le plan économique et environnemental. Cependant, leur caractère intermittent diminue leur efficacité énergétique lorsqu'elles sont exploitées individuellement. L'utilisation de systèmes hybrides (multi-sources) combinant ces sources d'énergie renouvelables, le réseau de distribution national (réseau électrique historique) et les systèmes de stockage classiques, est généralement considérée par tous comme solution d'avenir, à la fois efficiente et fiable. Il est alors nécessaire de repenser la structure des réseaux électriques et des marchés de l'énergie, ainsi que des changements dans les méthodes de gestion de réseau. Dans ce contexte, l'apport envisagé avec ce travail de thèse est de contribuer à la modélisation et l'optimisation de systèmes multi-sources multi-charges pour alimenter aussi bien des sites isolés « énergie de proximité » (campus, village) que des sites étendus tels que des régions françaises à travers leur interconnexion « pooling ». Différents scenarii de gestion et différentes configurations des systèmes sont modélisés, testés et comparés pour analyser l'efficacité et la robustesse de chaque cas de figure. Une analyse technico-économique complète est réalisée, dans le but d'étudier la faisabilité de chaque système. Pour démontrer la validation de ces modèles, des études ont été réalisées sur un campus Universitaire Français, un micro-réseau au Mali et trois régions Françaises. Ces dernières ont fait l'objet d'application à un modèle original d'interconnexion basé sur les réseaux de Pétri pour l'aide à la décision en termes de configurations du réseau et le contrôle des flux d'énergie échangés entre des territoires producteurs-consommateurs interconnectés sans système de stockage
Classement mécanique des bois de structure. Prise en compte des singularités dans la modélisation du comportement mécanique by Joffrey Viguier( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

The methods described in Eurocode 5 must be applied to the calculation of timber structures. The application of these methods requires prescribers to use wood whose mechanical properties are guaranteed. To assign a board to a class, three properties must be guaranteed: the density, the modulus of elasticity (MOE) and bending strength (MOR). The determination of the density and MOE is already mastered; the remaining technological obstacle concerns the prediction of MOR. The possibility to improve the prediction by measuring singularities (knot or slope of grain) or keeping the traceability of forest data has been investigated. Strength grading is governed by standards and the predictions quality of mechanical properties is not sufficient to evaluate the grading efficiency. Therefore the efficiency between different technologies has been compared on species with high harvest potential in France (Douglas fir, spruce and oak). The problems encountered when glulam beams are split have been analyzed. Particularly, the strength loss caused by the splitting process has been detailed and compared to the normative recommendations
Valorisation des marcs de raisins épuisés : vers un procédé d'extraction de tannins condensés à grande échelle pour la production d'adhesifs pour panneaux de particules by François Gambier( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Wastes from the French wine industry are traditionally treated and upgraded in distilleries. This work deals with the study of an industrial-scale valorization of a final waste from distilleries: the spent grape pomace. Pomace from different French production areas were chemically characterized, in terms of condensed tannins and polysaccharides. An extraction process of condensed tannins has been optimized in laboratory and was then transferred to an industrial scale. Several extractions were carried out in three partner distilleries and chemical analysis (in terms of polyphenols, condensed tannins, sugars and inorganics) of the different isolated fractions were performed. Industrial extracts were used for the elaboration of the first particleboard whose adhesive constituted by 80% of grape pomace tannins and strengthened with a synthetic resin to satisfy the European standard for internal bond. These industrial extracts were also used to partially substitute a phenol-formaldehyde resin for the production of particleboards. Different post-treatments were performed on the pomace extracts in order to increase their chemical reactivity toward cross linking agents. Filtration with a cut-off of 1 µm led to a slight improvement in adhesive performances, whereas acid hydrolysis of the extract have degraded it. An ultrafiltration process of the extracts at 5 kDa or at 1 kDa enabled to get much more reactive extracts and opened up prospects for the production of bio-based adhesives for wood
Valorisation chimique de la biomasse oléagineuse d'origine béninoise : Lophira lanceolata et Carapa procera by Guévara Nonviho( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

The chemical composition of wild oilseeds, such as Lophira lanceolata (Ll) and Carapa procera (Cp) of Benin is mostly unknown. Yet they undergo crafted transformations for food, cosmetic and therapeutic purposes. This study aims to characterize their seeds, hulls and woods. From these crops, different oils have been extracted. One of them has been produced in rural area according to aqueous ancestral method. On the whole, oils of Ll have presented an interesting nutritional profile. They are rich in polyunsaturated fatty acids (> 50% m/m: mass for mass), especially that extracted by artisanal process. Beyond its good chemical properties, it provides essential fatty acids, phytosterols such as lupeol and more tocols compounds. Roasting and the use of enzymes have also assessed the impact of these methods on the chemical composition of LI seeds. Differently, Cp oil's has an abundant presence of MUFA, tocotrienols (85.56% w/w) and the richest composition in lanosterol (28.03%, m/m). The seeds cakes, hulls and wood of both species showed various distributions on chemical components (extractives, hemicellulose, cellulose and lignin). The characterization of hemicelluloses from different parts of plants has shown that they are essentially glucuronoxylans type. Extractives also offered a wide range of compounds mostly appreciated for industrial and pharmaceutical purposes. The chemical composition of the shells of Lophira was rich in organic compounds such as lignin (32.13%, dry weight) so their biosorbent capacity was evaluated. They showed methylene blue good adsorption capacity in aqueous solution, which highlighted their potential use in the purification of wastewater
Valorisation de rebuts de bouteilles en verre et des cendres de bois dans la fabrication de briques en argile cuite by Gbènondé Sèna Gladys Milohin( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

L'argile est une ressource locale, abondante mais peu valorisée au Bénin. Le recyclage des déchets constitue de nos jours, un enjeu majeur au niveau mondial. Les briques d'argile cuite sont des matériaux à fort tonnage de production capables d'absorber différents produits considérés comme des déchets. Cette thèse vise d'une part la valorisation des matériaux de construction localement disponibles au Bénin, notamment l'argile et d'autre part, le recyclage des déchets en construction. Ainsi, nous nous proposons de valoriser des bouteilles en verre non recyclés et des cendres issues de la combustion du charbon de bois lors de la préparation des repas au Bénin, dans la matrice argileuse destinée à l'élaboration de briques cuites. Le but est de ressortir les formulations idéales des produits qui présentent des propriétés physiques et mécaniques suffisantes. Les études ont montré que le dosage de 5% des cendres de bois du Bénin et 20% de verres broyés favorise un gain de résistance à la traction par flexion trois points sans modifier la résistance à la compression des blocs d'argile cuits de Zogbodomey et de Sèmè-Podji. En outre, le dosage en ajout ne modifie pas les propriétés thermiques des blocs cuits. L'utilisation des cendres de charbon de bois et des déchets de verre comme matières premières secondaires dans la fabrication de briques cuites constitue alors un grand atout pour l'amélioration du cadre de vie des béninois
Analyse et conception d'un outil de coupe pour la valorisation des sous produits d'élagage des haies : démarche intégrée d'innovation et de prototypage by Alexandre Rougié( )

1 edition published in 2009 in French and held by 1 WorldCat member library worldwide

NOREMAT is specialized in the manufacturing of equipments for the maintenance of road verges. Its issue is to continuously propose profitable equipments to its customers. The company also wishes to design, thanks to scientific research, a new trimming concept offering more cost-efficient and ecological solutions. After a series of preliminary steps (analysis of French hedges, waste valorization options, design suggestion, analysis of trimming phenomena), a prototype was designed. This new tool fulfills three major functions: it cuts hedges economically and safely, it crushes the wastes into heating chips and collects them. Based upon the study of chips formation and the control of cutting parameters during the branches processing, this new tool offers a better trimming in comparison with the existing devices, while requiring less energy, adding value to waste products and protecting its surrounding area. Regarding scientific contribution, these researches have lead to a better understanding of the chip's building up in the specific case of flexible elements trimming
Development of innovative bio-based treatments for wood modification with bio-polyesters by Charlotte Grosse( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

Wood thermo-chemical modification process consists of permanent enhancement of wood properties in the core of the material. By decreasing wood equilibrium moisture content below the limit of fungi development, one could in addition reduce the dimensional variations due to humidity. A better dimensional stability of wood would be beneficial to durability of assemblies and surface coatings, further improving the performance of the material. Hydroxyl groups from wood polymers are responsible for the material hydrophilicity. The thermochemical modifications considered in this work mainly consist in limiting the access to these groups and / or reducing their number, by impregnation of bio-based monomers / oligomers (oligomers of lactic acid (OLA) or oligomers of butylene succinate (OBS)) followed by their in situ polymerisation by heat treatment. The hygroscopic behaviour of the material, the persistence of oligomers in the wood and the biological resistance of the treated wood are the criteria for the selection of treatments. The selected treatments lead to materials with enhanced dimensional stability and biological resistance. The potential applications of these materials have been evaluated after characterisation of mechanical properties, adhesion of the surface coatings and bonding capacity of the treated wood
Modélisation thermomécanique de la paroi des greniers de stockage de céréales en banco by Clément Labintan( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Le stockage des céréales se fait en milieu rural au nord du Bénin dans des greniers (silo) en terre qui ont une contenance limitée. Les nombreuses tentatives d'introduction de magasins modernes ont essuyé le rejet des populations. Le présent travail a pour but d'étudier la possibilité d'augmenter le volume de stockage du grenier de type Yom sans changer ni sa forme architecturale, ni le composite argile-paille-décoction de néré. La caractérisation expérimentale du comportement mécanique du banco, matériau de construction de ces greniers a permis de définir le meilleur dosage pour des caractéristiques maximales. En faisant varier la proportion de paille et de décoction de néré, l'influence sur la terre crue de la paille et de la décoction est mise en évidence. La simulation de l'action des grains, à la vidange et au remplissage sur la paroi du grenier et l'analyse des déformations induites montrent qu'il y a possibilité de construire des greniers de plus grande taille. Une optimisation paramétrique des dimensions a été faite. L'effet des échauffements successifs sur la paroi du grenier a été pris en compte à travers la modélisation des transferts thermiques. La modélisation des profils de température dans diverses coupes orientées du silo montre que le flux est bien amorti et les conditions d'ambiance dans le grenier garantissent une bonne conservation. Il est donc possible de construire des greniers de grande capacité de stockage qui serviraient de greniers communautaires ou banques de céréales à disposition des coopératives villageoises. Cette solution règlerait le problème de l'insécurité alimentaire au niveau du monde rural
 
moreShow More Titles
fewerShow Fewer Titles
Audience Level
0
Audience Level
1
  Kids General Special  
Audience level: 0.96 (from 0.93 for Étude de ... to 0.96 for Étude de ...)

Alternative Names
Laboratoire d'Études et de Recherche sur le MAtériau Bois (Épinal)

Laboratoire d'Études et de Recherche sur le MAtériau Bois - UMR 1093

Laboratoire d'Études et de Recherche sur le MAtériau Bois (Vandoeuvre-lès-Nancy)

LERMAB

Languages
French (19)

English (3)