HAL Portal UBS (Université Bretagne Sud)
Not a member yet
14201 research outputs found
Sort by
Quantification et impact des défauts sur la structure et les performances de fibres de lin textile en environnements contrastés
No full textFlax, cultivated since ancient times for its fibres, yarns and fabrics, is now emerging as an essential ecological alternative for the textile and composite industries of the future. With its mechanical properties, versatility, traceability and energy efficiency, it represents a material full of potential for innovation and sustainability. However, a number of challenges still limit its optimal exploitation. In six chapters, this thesis explores the impact of flax defects on the structure and performance of its fibres. One of the main challenges in flax scutching is the separation of fibres and co-products, known as shives. Throughout this thesis, new analytical approaches were developed and validated on industrial samples to facilitate the quantification of these shives. At a finer scale, the research focuses on defects in individual fibres, the kink-bands. A multi-scale analysis is carried out to assess the impact of these zones on the mechanical properties of the fibres, taking into account the effects of scutching and hackling conditions. This is followed by a detailed analysis of the local mechanical and biochemical properties of areas with and without kink-bands. In addition, samples of archaeological flax were examined using synchrotron microtomography to study the degradation of flax fibres over time. Finally, hygroscopic tests are performed to observe the behaviour of kink-bands under varying humidity conditions. The results of this latest work open up new perspectives on the potential impact of kink-bands on the wrinkling of flax fabrics.Le lin, cultivé depuis l'Antiquité pour ses fibres, fils et tissus, s'affirme aujourd'hui comme une alternative écologique incontournable pour les industries textile et composite de demain. Grâce à ses caractéristiques mécaniques, sa polyvalence, sa traçabilité et sa sobriété énergétique, il représente un matériau porteur d'innovation et de durabilité. Cependant, plusieurs défis limitent encore son exploitation optimale. Cette thèse explore, à travers six chapitres, l'impact des défauts du lin sur la structure et les performances de ses fibres. L'un des principaux défis du teillage du lin réside dans la séparation des fibres et des coproduits, appelés anas. Au cours de cette thèse, de nouvelles approches analytiques ont été développées et validées sur des échantillons industriels afin de faciliter la quantification de ces anas. À une échelle plus fine, les travaux se concentrent ensuite sur les défauts des fibres unitaires, les kink-bands. Une analyse multi- échelle est menée pour évaluer l'impact de ces zones sur les propriétés mécaniques des fibres, en prenant en compte les effets des conditions de teillage et de peignage. Ce chapitre est suivi d'une analyse approfondie des propriétés mécaniques et biochimiques locales des zones présentant ou non des kink-bands. Par ailleurs, des échantillons archéologiques de lin ont été examinés par micro- tomographie synchrotron afin d'étudier la dégradation des fibres de lin au fil du temps. Enfin, des tests hygroscopiques sont réalisés pour observer le comportement des kink-bands sous différentes conditions d’humidité. Les résultats de ces derniers travaux ouvrent de nouvelles perspectives sur l'impact potentiel des kink-bands sur le froissage des tissus en lin
Le lobby du sucre français entre dans les écoles. L'exemple des publications pédagogiques du Cédus (années 1950-années 1990)
No full textInternational audienc
Fathers and Mothers through Children's Eyes: A Child-Centered Approach Using NLP and Qualitative Analysis
No full textInternational audienceParental roles are fundamental in shaping children's understanding of the world and their interactions with others. While much research has explored adult perspectives on these roles, less attention has been given to how children perceive and articulate them. Traditional studies often rely on retrospective adult accounts or structured questionnaires which may not be accessible for young children. These methods often impose adult-centric biases, failing to capture the unique ways in which children express their thoughts and navigate social dynamics. By focusing on children's narratives, we aim to provide a more direct and authentic understanding of their perceptions.Our research seeks to understand the stereotypes children associate with parental roles, exploring their prevalence, significance, and stability across age and gender at two key stages of schooling. Conducted as part of a French research project, this study analyzes interviews with 184 schoolchildren aged 6 to 11. The children answered two open-ended questions about what words come to mind when they think of 'father' and 'mother' and what these concepts represent. Their spontaneous responses were transcribed, forming a corpus of 46,600 words.We address the following research questions: 1) How do children perceive the roles of mothers and fathers? 2) How do these perceptions vary across age groups and genders?Our study combines Natural Language Processing (NLP) with qualitative analysis to explore these perceptions. Contextual dictionaries for each concept were developed, identifying significant lemmas—frequent and meaningful terms—in the children's discourse. These were used to construct knowledge graphs, capturing both lexical patterns in the corpus and deeper semantic relationships.The themes identified, as shown in Table 1, highlight shared responsibilities and notable distinctions between the roles of mothers and fathers. The father lexicon contains 20 salient lemmas, while the mother lexicon includes 30. Notably, all significant lemmas related to fathers also appear in the mother lexicon, except for 'game', suggesting that children view mothers as capable of fulfilling both maternal and paternal roles, though with different emphases.We observe a largely shared view of parental roles, with key differences. Mothers are linked to childbirth and broader familial connections, while fathers are more associated with the immediate family structure. The exclusive association of 'game' with fathers may reflect a stereotypical view of them being more involved in play, particularly physical or technology-based activities. Figure 1 highlights an inversion, with fathers more associated with 'Instructive and Playful' roles, and mothers with 'Executive and Household Management' functions.Statistical analyses revealed stronger associations of managerial roles with mothers, emotional roles with girls, and gender and age differences in instructive and playful roles for fathers.While our findings support some traditional views of parental roles, they also challenge the conventional gendered division of labor, showing more overlap between roles. However, the lack of comprehensive sociodemographic data limits further exploration of how variables such as family structure or socioeconomic status might influence children's perceptions. Future research should incorporate these factors to offer a more nuanced understanding of children's social cognition within diverse family contexts
Entretien avec Joséphine Boivineau, « une nymphe en basket ». De l’école du Centre national de danse contemporaine d’Angers à la Compagnie Sortie de secours, une trajectoire vers l’émergence
No full textInternational audienceThis interview looks behind the scenes at the creation of a young choreographic artist wishing to develop her own projects after completing her training at the Centre national de danse contemporaine in Angers, a benchmark school for contemporary dance in France since 1978. The challenge is therefore twofold: firstly, to understand the conditions that make it possible for the emergence and work of a young artist who chooses to set up her own company, while at the same time resorting to bricology, bringing into play the networks resulting from her training and opportune encounters. The choices made by young artists falling into the vague category of emergence are currently the subject of much debate in the context of a tightening cultural economy: peer teaching, pooling, etc. At what point does an artist become a professional? How do they gain access to institutional support and enter the process of responding to calls for projects and applying for grants? What kind of artistic project, both aesthetic and political, do they defend? There are many points of passage, both real and symbolic (intermittence...) to be crossed. It is important, therefore, to approach the first steps of structuring by example, not with the aim of making an exemplary figure but of contributing to a mapping of the emergence of as yet unknown artists. In this case, Joséphine Boivineau, a dancer who graduated from the Cndc in 2019-2021. Keen to develop her own projects, she set up her own company, Sortie de secours, in 2021, with which she explores the complex links between the body, sound and music in their relationship to space.Cet entretien se propose de découvrir les coulisses de la création d’une jeune artiste chorégra-phique souhaitant développer ses propres projets au sortir de sa formation au Centre national de danse contemporaine à Angers, école de référence pour la danse contemporaine en France depuis 1978. L’enjeu est en premier lieu de comprendre les conditions de possibilité de l’émergence et du travail d’une jeune artiste faisant le choix de monter sa propre compagnie tout en faisant appel à la bricologie, aux réseaux issus de sa formation et aux rencontres opportunes. En effet, les choix ef-fectués par les jeunes artistes relevant de la catégorie floue de l’émergence sont actuellement en plein débat au regard d’une économie de la culture qui se resserre : enseignement par les pairs, mutualisation… A partir de quand l’artiste devient-il professionnel ? Comment accède-t-il au sou-tien institutionnel et entre-t-il dans la dynamique de réponse à des appels à projets et de montage de dossiers de subventions ? Quel projet artistique, tout à la fois esthétique et politique défend-il ? Nombreux sont les lieux de passages, réels et symboliques (intermittence…) à franchir. Il importe donc d’approcher les premiers pas de la structuration par l’exemple, non pas dans le projet d’en faire une figure exemplaire mais de contribuer à une cartographie de l’émergence d’artistes encore inconnu.e.s. Celle-ci ne saurait trouver tout son sens sans présenter le projet artistique porté par l’artiste, en l’occurrence celui de Joséphine Boivineau, danseuse issue de la formation 2019-2021 du Cndc. Désireuse de porter ses propres projets, elle monte sa compagnie Sortie de secours en 2021 avec laquelle elle interroge les liens complexes unissant le corps, le son et la musique dans leur relation à l’espace
Overview of composites at IRDL/Lorient and Specific numerical methods for buckling analysis
No full textInternational audienceThis talk is thought has an invitation for scientific collaboration on composites research or any specific numerical methods.First, our lab has a local context of "Sailing and Composite valley" and a CNRS mission to work on marine engineering. For example, high performance racing sailing boats, using hydrofoils and solid-sails, are designed and built in south Brittany, including Lorient.After that context description, a non exhaustive overview will be given regarding our expertise in bio-based composites, fiber characterization, material science, bio-mimicry, additive manufacturing, for naming a few.Moreover, as we also have a long expertise on numerical methods for non linear problems as instabilities, damping properties of hybrid composite vibration and reduced order modeling, a focus will be made on their application for composite structures.Finally, application of the asymptotic numerical method for continuation, singularities detection and branch switching, will be depicted in a general context with some applications to 3D fluid flows and buckling of elastic structures
La fleur, le cochon, le flacon et le cadavre : écofacts et artefacts en scénographie funéraire: Actes du 1er Rendez-vous du Gaaf (Lorient, Aix-en-Provence, La Rochelle ; 2016-2018)
No full textInternational audienceA flower, a pig, a bottle - this is a Prévert-style inventory that seems more poetic than realistic, because what do plants, animals and objects have in common? And how can they coexist in the same reality? The answer lies in the reference to the corpse. It is the corpse that explains the statement, it is its presence that defines the context and motivates the investigation, which is not judicial but archaeological. Priority must be given to the corpse, whatever its form and whatever remains of it. The corpse is the human being, and without the human being the flower, the pig, the bottle would not exist. A grave is just one part of a complex chain of funerary operations that began with the death of an individual and only ends when his or her memory has faded.Through twelve contributions, initially presented orally as part of the first Gaaf Rendez-vous, and presented according to the sources used (written and then archaeological) and in chronological order, this book demonstrates the diversity of possible scientific approaches when studying funerary rituals and the value of bringing researchers together in multidisciplinary approaches.Une fleur, un cochon, un flacon, voici un inventaire à la Prévert qui paraît plus poétique que réaliste, car quel point commun peut-il exister entre un végétal, un animal et un objet ? Et comment peuvent-ils coexister dans une même réalité ? La réponse est fournie par la référence au cadavre. C’est le cadavre qui explique l’énoncé, c’est sa présence qui définit le contexte et motive l’enquête qui n’est pas judiciaire mais archéologique. La priorité doit en effet être donnée au cadavre, quelle que soit sa forme et ce qu’il en reste. Le cadavre c’est l’humain, et sans l’humain la fleur, le cochon, le flacon n’existeraient pas. Une tombe n’est qu’une partie d’une chaîne opératoire funéraire complexe qui a commencé avec le trépas d’un individu et qui ne s’achève que quand son souvenir s’est éteint.À travers douze contributions initialement présentées oralement dans le cadre des premiers Rendez-vous du Gaaf et présentées selon les sources utilisées (écrites puis archéologiques) et par ordre chronologique, cet ouvrage rend compte de la diversité des approches scientifiques possibles lorsqu’on étudie les rituels funéraires et de l’intérêt de faire dialoguer les chercheurs dans des approches pluridisciplinaires
Le Venezuela d’une élection à l’autre : autoritarisme, participation et migrations
No full textInternational audienc
Functional Mobility Assessment after Unilateral Knee Arthroplasty: A Comparative Study of Two Prosthesis Types
No full textInternational audienceAims: To evaluate and compare the functional mobility of patients undergoing unilateral knee arthroplasty using two prostheses: fixed tibial plateau and rotating platform. This study addresses a gap in the existing literature by providing detailed insights into functional mobility patterns and prosthesis-specific outcomes. Study Design: A prospective, observational, and comparative study with assessments conducted at two-time points: 12 to 24 months after surgery. Place and Duration of Study: Conducted at a tertiary hospital for rehabilitation and readaptation, in partnership with a private university from March 2022 to December 2024. Methodology: Thirty-six patients who had previously undergone unilateral knee arthroplasty were included, equally divided between fixed and rotating platform prostheses. The Timed Up and Go (TUG) test, performed with the G-WALK inertial sensor, captured 15 functional mobility variables across two time points. Statistical analyses included variance tests and correlations to identify changes between time points and groups. Results: The mean TUG time increased from 14.47 ± 3.03 seconds to 15.24 ± 3.85 seconds without statistical significance (P=.301). However, the Sit-to-Stand phase significantly reduced duration (P=.036). The turning phase demonstrated significant improvements in both duration (P<.001) and speed (P<.001). No statistically significant differences were observed between prosthesis types in most variables. The comparison between fixed and rotating platform prostheses is clinically important as it provides insights for tailoring postoperative rehabilitation strategies. Conclusion: Fixed and rotating platform prostheses demonstrated comparable functional performance, with specific improvements noted over time. The findings emphasize the value of inertial sensors in conducting detailed clinical assessments and suggest opportunities for further research to enhance prosthesis selection and rehabilitation protocols. This study contributes to clinical practice by offering evidence that supports personalized rehabilitation strategies
New coastal records in northern Brittany (Plouescat, NW France): Sedimentological, palynological and paleogenomic data over the last 7.3 ka BP
No full textInternational audienceThe multidisciplinary approach conducted on the coastal cores ANE-C3 and PADMé (48°38'54.5114\"N; 4°10'21.3848\"W; Kerallé watershed, NW Brittany, NW France) revealed paleoenvironmental trajectories under both relative sea level rise and anthropogenic dynamics during Middle to Late Holocene, in the research paper: \"From a coastal plain to an anthropized fluvial valley (NW Brittany, France): 7.3 kyr of paleoenvironmental evolution from sedimentological, palynological and paleogenomic perspectives\" [1]. This additional article presents all the ANE-C3 and PADMé cores dataset discussed in [1] including sedimentological (XRF, grain size), palynological (pollen assemblages) and paleogenomic (plant and mammal sedimentary ancient DNA or sedaDNA) data. For the sedimentological data, the documents included here comprise high-resolution photographs and normalization of XRF-counts. A special emphasis was placed on characterising the modern pollinic signal in different sub-environments (i.e., salt marsh, coastal meadow, field) of the studied area. This was done to identify anthropogenic pollen indicators specific to this coastal zone, and, ultimately to detect more precisely the pollinic signature of human disturbances in the fossil record. Finally, this paper provides additional information on the methodologies developed, with a particular emphasis on sedaDNA analysis