Développement d'un système de finition polymérisable aux UV super performant

Les revêtements de couvre-planchers en bois appliqués en surface afin d'améliorer la durabilité du bois sont soumis à de nombreuses sollicitations au cours de leur durée de vie en service. Parmi les différents types d'agressions (chimiques, mécaniques, environnementales) auxquelles un revêtement doit faire face, les agressions mécaniques sont les plus problématiques. Ces dernières peuvent créer des défauts en surface de la finition (rayures, indentations, usure) pouvant considérablement altérer l'aspect de la finition et réduire la durabilité du couvre-plancher. L'apparition de défauts en surface d'un système de finition peut indiquer une performance mécanique trop faible. L'objectif principal de ce projet est d'améliorer les propriétés mécaniques des revêtements polymérisables par rayonnement UV pour les couvre-planchers en bois à travers l'analyse et la compréhension de leurs comportements physico-chimiques. Deux axes de recherche ont été définis. Le premier traite de l'inhibition causée par l'oxygène, lors de la polymérisation radicalaire, impactant la surface des revêtements, et l'utilisation de nouveaux composés permettant de réduire cette action inhibitrice. Le second axe a pour objectif d'améliorer la résistance mécanique de systèmes de finitions multicouches et de mieux comprendre l'influence des propriétés apportées individuellement par les différentes couches. Dans le premier axe, une étude a été menée afin de caractériser les problématiques liées à l'inhibition de l'oxygène. Des analyses en microspectroscopie Raman ont permis d'étudier l'impact de l'inhibition par l'oxygène selon sa profondeur de diffusion. De nouveaux composés n'ayant jamais été utilisés pour la réduction de l'inhibition par l'oxygène ont été incorporés selon leurs fonctions chimiques et leur effet supposé lors de la polymérisation en présence d'oxygène. Leur capacité à réduire l'inhibition a été comparée à celle d'autres composés déjà décrits dans la littérature, mais utilisés selon d'autres conditions opératoires. En plus de comparer l'efficacité de ces composés lors de la polymérisation des formulations, leur impact sur la résistance mécanique de la finition a été considéré. L'action de l'oxygène étant limitée par sa diffusion au sein de la formulation, l'inhibition est généralement plus importante en surface des revêtements. Des essais d'abrasion de surface et de dureté pendule ont permis de compléter cette étude en comparant l'efficacité des composés. Le deuxième axe vise à approfondir la compréhension du comportement de finitions multicouches, lorsque soumis à des indentations ou des rayures. Dans un premier temps, la relation structure-propriété d'une finition a été analysée par la formulation de couples monomère-oligomère. Les propriétés physico-chimiques, telles que la température de transition vitreuse (Tg) et la densité de réticulation, des polymères seuls ont été déterminées par analyse mécanique dynamique (DMA). Dans un second temps, les formulations ont été appliquées en couche de surface. La dureté, la résistance à l'abrasion, la résistance à la rayure et la résistance à la friction de la couche de surface au sein d'un système de finition appliqué sur le bois ont été étudiées. Les résultats obtenus ont permis une meilleure compréhension du comportement de la couche de surface lors de sollicitations mécaniques. Une meilleure perception des paramètres influençant la performance mécanique de la couche de surface au sein d'un système de finition multicouche industriel a ainsi pu être acquise. Afin d'approfondir la compréhension du comportement d'un système de finition multicouche, l'influence des propriétés de la couche de scellant a, elle aussi, été étudiée. A nouveau, les propriétés physico-mécaniques des formulations réticulées individuellement ont été analysées par DMA. Par la suite, l'influence des propriétés du scellant sur la dureté et la résistance à la rayure d'une finition multicouche a pu être évaluée. Le rôle du scellant étant d'absorber et de diffuser une partie des forces subies par les couches de surface, l'influence de l'épaisseur du scellant a également été étudiée. De plus, l'influence des scellants sur le profil des rayures à la surface des systèmes de finition, a été observée par profilométrie de surface. Une corrélation entre l'épaisseur totale de scellant appliquée et la profondeur moyenne des rayures a pu être établie. L'influence des propriétés des différentes formulations appliquées sur la résistance aux rayures a pu aussi être étudiée. À l'épaisseur maximale appliquée, les produits ayant un réseau plus dense résistent mieux aux rayures en présentant une plus petite profondeur de pénétration.Coatings for wood flooring, applied on the wood surface to enhance its durability, undergo numerous mechanical stresses during their lifetime. Among the various damages (chemical, mechanical, environmental) that coatings have to resist to, mechanical damages are the most problematic. Mechanical damages can generate failures at the surface of the finish (scratches, indentations, wear) that can significantly affect the finish aspect and reduce the flooring's durability. The formation of surface failures may indicate insufficient mechanical properties. The main objective of this work is to enhance the mechanical properties of UV-curable coatings for wood flooring and to better understand their physicochemical behavior. Two research axes were defined. The first one concerns the oxygen inhibition of the UV-curable acrylate polymerization that affects the coating surface and the use of several new compounds able to reduce oxygen inhibition. The main objective of the second axis was to improve the mechanical performances of multilayered finishing system and to was used to distinguish the impact of inhibition caused by oxygen according to the depth of oxygen diffusion. Products never used to reduce the oxygen inhibition were added to formulations, according to their chemical nature and their supposed effect on oxygen inhibition. Their efficiency was then compared to the efficiency of several compounds, already described in the literature, but under different experimental conditions. In addition to the comparison of the compounds' efficiency during the formulations polymerization, their effect on the mechanical properties of the coating was considered. As the influence of oxygen is limited by its diffusion in the formulation, the inhibition is generally higher at the coatings surface. Abrasion tests and pendulum hardness helped to complete the study and give a broader discernment of the compounds' efficiency. The main purpose of the second axis was to deepen the comprehension of multilayered finish systems behavior when submitted to mechanical loads. First, the structure-property relationship of finishing systems was analyzed by formulating monomer-oligomer couples applied as topcoats. Physico-chemical properties, such as glass transition temperature (Tg) and crosslinking density (CLD), were measured by dynamic mechanical analysis (DMA). Secondly, topcoat hardness, abrasion, scratch and friction resistances were determined. These results enabled a better understanding of the topcoat behavior when exposed to various mechanical loads. A better perception of the parameters influencing the topcoat mechanical. In order to investigate further the finishing system mechanical behavior, the influence of the basecoat properties was evaluated. Once again, the physico-chemical properties of the formulations were analyzed separately by DMA. Then, the influence of the basecoat properties on hardness and scratch resistance of a multilayered finish was determined. As the role of the basecoat is to absorb and diffuse partly the mechanical loads endured by surface layers, the impact of basecoat thickness was also investigated. Moreover, the effect of the basecoats on the scratch profile was examined by surface profilometry. A correlation between the basecoat thickness and the mean depth of scratches was obtained. The influence of the various formulation properties on the scratch resistance was also demonstrated. At the maximal thickness applied, basecoat having a denser polymeric network withstand better scratches as they showed a lower mean scratch depth

Cancer Du Sein Inflammatoire Chez La Femme Camerounaise

Introduction : Le cancer du sein inflammatoire (CSI), est relativement fréquent chez la jeune femme camerounaise. L’objectif était de présenter les caractéristiques du CSI en milieu camerounais. Patients et méthodes : Il s’est agi d’une étude transversale descriptive, multicentrique à collecte rétrospective allant du 1er Janvier 2010 au 31 Décembre 2014. Ont été inclues toutes les femmes de nationalité camerounaise diagnostiquées pour un CSI histologiquement confirmé. Résultats : Vingt-et-un cas de CSI ont été colligés et représentaient 3% de l’ensemble des mastopathies dans quatre hôpitaux. L’âge moyen des patientes était de 37,7 ans. Quatorze (66,7%) femmes avaient consulté après un intervalle supérieur à six mois. La localisation de la tumeur était unilatérale dans tous les cas. Dix-huit (85,7%) des patientes avaient un statut ganglionnaire cliniquement positif. La taille tumorale médiane était de 5cm. Les patientes étaient classées respectivement PEV3 dans 52,4%, PEV2 dans 28, 6% et PEV1 dans 19%. Huit patientes (38%) étaient métastatiques. Seize (76,2%) femmes avaient une négativité aux récepteurs œstrogènes et progestérones. Le carcinome canalaire infiltrant était le plus fréquent (66,6%). Treize (62%) patientes ont recouru au traitement traditionnel rituel. Une chimiothérapie néoadjuvante et adjuvante était systématiquement instituée. Dix-huit (85,7%) patientes étaient opérables et avaient bénéficié d’une mastectomie. Six cas de récidive ont été notés au cours du suivi. La survie à cinq ans était de 42, 9%. Conclusion : L’utilisation systématique de la chimiothérapie neoadjuvante et adjuvante a amélioré le pronostic du CSI. Introduction: Inflammatory breast cancer (IBC) is relatively common in young Cameroonian women. This paper aims to present the characteristics of the IBC in the Cameroonian environment. Patients and Methods: The paper uses a descriptive, multicentre cross-sectional study with retrospective collection from 1st of January 2010 to 31st of December 2014. All Cameroonian women affected by an IBC diagnosed and histologically confirmed were included in the study. Results: Twenty-one cases of IBC, which represented 3% of all treated mastopathies, was collected in four Church Hospitals. The mean age of the patients was 37.7 years. Fourteen (66.7%) consulted after an interval more than six months. The location of the tumour was unilateral in all of the cases. Eighteen (85.7%) of the patients had clinically positive lymph node status. The median tumour size was 5cm. The patients were classified into PEV3 52.4%, PEV2 28.6% and PEV1 19%, respectively. Eight patients (38%) were metastatic. Sixteen (76.2%) women had negative oestrogen and progesterone receptors. The most common histologic type was invasive ductal carcinoma with 66.6% of cases. Thirteen (62%) patients used traditional ritual treatment. Neo-adjuvant and adjuvant chemotherapy were systematically instituted. Eighteen (85.7%) patients were operable and had undergone mastectomy. Six (33.3%) cases of recurrence were observed during the follow-up. The 5-years survival was 42.9%. Conclusion: Systematic use of neo-adjuvant and adjuvant chemotherapy improved the prognosis of IBC

Plagiarism meets paraphrasing: insights for the next generation in automatic plagiarism detection

[EN] Although paraphrasing is the linguistic mechanism underlying many plagiarism cases, little attention has been paid to its analysis in the framework of automatic plagiarism detection. Therefore, state-of-the-art plagiarism detectors find it difficult to detect cases of paraphrase plagiarism. In this article, we analyze the relationship between paraphrasing and plagiarism, paying special attention to which paraphrase phenomena underlie acts of plagiarism and which of them are detected by plagiarism detection systems. With this aim in mind, we created the P4P corpus, a new resource that uses a paraphrase typology to annotate a subset of the PAN-PC-10 corpus for automatic plagiarism detection. The results of the Second International Competition on Plagiarism Detection were analyzed in the light of this annotation.The presented experiments show that (i) more complex paraphrase phenomena and a high density of paraphrase mechanisms make plagiarism detection more difficult, (ii) lexical substitutions are the paraphrase mechanisms used the most when plagiarizing, and (iii) paraphrase mechanisms tend to shorten the plagiarized text. For the first time, the paraphrase mechanisms behind plagiarism have been analyzed, providing critical insights for the improvement of automatic plagiarism detection systems.We would like to thank the people who participated in the annotation of the P4P corpus, Horacio Rodriguez for his helpful advice as experienced researcher, and the reviewers of this contribution for their valuable comments to improve this article. This research work was partially carried out during the tenure of an ERCIM "Alain Bensoussan" Fellowship Programme. The research leading to these results received funding from the EU FP7 Programme 2007-2013 (grant no. 246016), the MICINN projects TEXT-ENTERPRISE 2.0 and TEXT-KNOWLEDGE 2.0 (TIN2009-13391), the EC WIQ-EI IRSES project (grant no. 269180), and the FP7 Marie Curie People Programme. The research work of A. Barron-Cedeno and M. Vila was financed by the CONACyT-Mexico 192021 grant and the MECD-Spain FPU AP2008-02185 grant, respectively. The research work of A. Barron-Cedeno was partially done in the framework of his Ph.D. at the Universitat Politecnica de Valencia.Barrón Cedeño, LA.; Vila, M.; Martí, MA.; Rosso, P. (2013). Plagiarism meets paraphrasing: insights for the next generation in automatic plagiarism detection. Computational Linguistics. 39(4):917-947. https://doi.org/10.1162/COLI_a_00153S917947394Barzilay, Regina. 2003. Information Fusion for Multidocument Summarization: Paraphrasing and Generation. Ph.D. thesis, Columbia University, New York.Barzilay, R., & Lee, L. (2003). Learning to paraphrase. Proceedings of the 2003 Conference of the North American Chapter of the Association for Computational Linguistics on Human Language Technology - NAACL ’03. doi:10.3115/1073445.1073448Barzilay, Regina and Kathleen R. McKeown. 2001. Extracting paraphrases from a parallel corpus. In Proceedings of the 39th Annual Meeting of the Association for Computational Linguistics (ACL 2001), pages 50–57, Toulouse.Barzilay, R., McKeown, K. R., & Elhadad, M. (1999). Information fusion in the context of multi-document summarization. Proceedings of the 37th annual meeting of the Association for Computational Linguistics on Computational Linguistics -. doi:10.3115/1034678.1034760Bhagat, Rahul. 2009. Learning Paraphrases from Text. Ph.D. thesis, University of Southern California, Los Angeles.Cheung, Mei Ling Lisa. 2009. Merging Corpus Linguistics and Collaborative Knowledge Construction. Ph.D. thesis, University of Birmingham, Birmingham.Cohn, T., Callison-Burch, C., & Lapata, M. (2008). Constructing Corpora for the Development and Evaluation of Paraphrase Systems. Computational Linguistics, 34(4), 597-614. doi:10.1162/coli.08-003-r1-07-044Dras, Mark. 1999. Tree Adjoining Grammar and the Reluctant Paraphrasing of Text. Ph.D. thesis, Macquarie University, Sydney.Faigley, L., & Witte, S. (1981). Analyzing Revision. College Composition and Communication, 32(4), 400. doi:10.2307/356602Fujita, Atsushi. 2005. Automatic Generation of Syntactically Well-formed and Semantically Appropriate Paraphrases. Ph.D. thesis, Nara Institute of Science and Technology, Nara.Grozea, C., & Popescu, M. (2010). Who’s the Thief? Automatic Detection of the Direction of Plagiarism. Lecture Notes in Computer Science, 700-710. doi:10.1007/978-3-642-12116-6_59GÜLICH, E. (2003). Conversational Techniques Used in Transferring Knowledge between Medical Experts and Non-experts. Discourse Studies, 5(2), 235-263. doi:10.1177/1461445603005002005Harris, Z. S. (1957). Co-Occurrence and Transformation in Linguistic Structure. Language, 33(3), 283. doi:10.2307/411155KETCHEN Jr., D. J., & SHOOK, C. L. (1996). THE APPLICATION OF CLUSTER ANALYSIS IN STRATEGIC MANAGEMENT RESEARCH: AN ANALYSIS AND CRITIQUE. Strategic Management Journal, 17(6), 441-458. doi:10.1002/(sici)1097-0266(199606)17:63.0.co;2-gMcCarthy, D., & Navigli, R. (2009). The English lexical substitution task. Language Resources and Evaluation, 43(2), 139-159. doi:10.1007/s10579-009-9084-1Recasens, M., & Vila, M. (2010). On Paraphrase and Coreference. Computational Linguistics, 36(4), 639-647. doi:10.1162/coli_a_00014Shimohata, Mitsuo. 2004. Acquiring Paraphrases from Corpora and Its Application to Machine Translation. Ph.D. thesis, Nara Institute of Science and Technology, Nara.Stein, B., Potthast, M., Rosso, P., Barrón-Cedeño, A., Stamatatos, E., & Koppel, M. (2011). Fourth international workshop on uncovering plagiarism, authorship, and social software misuse. ACM SIGIR Forum, 45(1), 45. doi:10.1145/1988852.198886

Comparative study of the impact of additives against oxygen inhibition on pendulum hardness and abrasion resistance for UV-curable wood finishes

International audienc

Multi-Pivot Translation by System Combination

This paper describes a technique to exploit multiple pivot languages when using machine translation (MT) on language pairs with scarce bilingual resources, or where no translation system for a language pair is available. The principal idea is to generate intermediate translations in several pivot languages, translate them separately into the target language, and generate a consensus translation out of these using MT system combination techniques. Our technique can also be applied when a translation system for a language pair is available, but is limited in its translation accuracy because of scarce resources. Using statistical MT systems for the 11 different languages of Europarl, we show experimentally that a direct translation system can be replaced by this pivot approach without a loss in translation quality if about six pivot languages are available. Furthermore, we can already improve an existing MT system by adding two pivot systems to it. The maximum improvement was found to be 1.4 % abs. in BLEU in our experiments for 8 or more pivot languages. 1

Industrial Byproducts as Adhesive Allies: Unraveling the Role of Proteins and Isocyanates in Polyurethane Wood Bonding

Wooden structures are becoming increasingly popular in the construction world. However, these structures often rely on synthetic adhesives, raising concerns about the environmental risks associated with their chemical composition. In response to these concerns, this study aims to explore sustainable alternatives, particularly focusing on polyurethane adhesives that incorporate proteins from industrial byproducts. The investigation involved three protein sources: soybean meal, shrimp shells, and skim milk, modified under mild alkaline conditions to obtain protein concentrates. These concentrates were then incorporated into the adhesives at varying protein contents: 5%, 10%, and 15%. Additionally, two isocyanate systems were examined, one being petrochemical-based and the other a partially bio-based blend. Chemical, thermal, optical, and mechanical characterizations were conducted to evaluate the adhesive performance. This study demonstrates that the adhesives’ thermal properties remain unaffected by both the protein content and the isocyanate system. However, these factors influence the adhesive penetration into the wood substrate. Ultimately, the results suggest that higher protein content offers superior retention of mechanical strength in adhesives compared to the petrochemical reference when subjected to humid conditions. Overall, this research demonstrates the potential of proteins from industrial byproducts as sustainable adhesive allies, providing valuable insights into their interactions with different isocyanates

Industrial Byproducts as Adhesive Allies: Unraveling the Role of Proteins and Isocyanates in Polyurethane Wood Bonding

Wooden structures are becoming increasingly popular in the construction world. However, these structures often rely on synthetic adhesives, raising concerns about the environmental risks associated with their chemical composition. In response to these concerns, this study aims to explore sustainable alternatives, particularly focusing on polyurethane adhesives that incorporate proteins from industrial byproducts. The investigation involved three protein sources: soybean meal, shrimp shells, and skim milk, modified under mild alkaline conditions to obtain protein concentrates. These concentrates were then incorporated into the adhesives at varying protein contents: 5%, 10%, and 15%. Additionally, two isocyanate systems were examined, one being petrochemical-based and the other a partially bio-based blend. Chemical, thermal, optical, and mechanical characterizations were conducted to evaluate the adhesive performance. This study demonstrates that the adhesives’ thermal properties remain unaffected by both the protein content and the isocyanate system. However, these factors influence the adhesive penetration into the wood substrate. Ultimately, the results suggest that higher protein content offers superior retention of mechanical strength in adhesives compared to the petrochemical reference when subjected to humid conditions. Overall, this research demonstrates the potential of proteins from industrial byproducts as sustainable adhesive allies, providing valuable insights into their interactions with different isocyanates

Understanding indentation, scratch and wear behavior of UV-cured wood finishing products

In the wood furniture and flooring industry, the protection and aesthetic properties of the final product often rely, at least partially, on the coatings applied on the wood surface. For flat surfaces, UV-cured coatings are often preferred due to their multiple advantages, such as high curing speeds, low volatile organic compounds (VOC) content, low energy consumption and high crosslinking densities. To increase the durability of interior wood products, the behavior of the protective coatings, while subjected to wear and deterioration, has to be understand in order to be enhanced. According to the type of solicitation, mar (i.e. shallow defect), scratches or indentations can be formed, which impact the coating’s appearance and can shatter the perception of the whole product. In this work, formulations based on different monomer-oligomer couples were prepared and photo-polymerized to investigate their performances. First, the glass transition temperature and the crosslinking density were determined to understand the contribution of both components in the polymeric network formed upon UV-curing. Then abrasion resistance, hardness, scratch and wear resistance were studied. The results showcased the importance of monomer and oligomer structure, functionality and main physical properties. In scratch experiments, hard and brittle coatings tend to display failures at lower loads than soft and ductile ones, whereas hard coatings are able to better withstand higher forces during indentations experiment. Friction experiments also caused subsurface tearing and fissuring in the soft coatings while generating several fractures in harder ones. Furthermore, the best overall mechanical resistance was obtained for the couples achieving high crosslinking density and a correlation between the crosslinking density of UV-cured coatings and their hardness was found. Interestingly, the investigation of tracks after scratch and wear experiments revealed a significant amount of information toward coatings behavior under various mechanical loads