HAL - La Rochelle Université, Archives Ouvertes
Not a member yet
19516 research outputs found
Sort by
A methodology to bridge urban shade guidelines with climate metrics
No full textInternational audienceUrban overheating poses significant challenges to public comfort and health, particularly in pedestrian areas. While urban climate studies offer detailed maps of thermal discomfort and heat stress, urban planning often relies on simplified guidelines, creating a gap between research and practice. This study introduces a methodology to bridge this gap by developing a spatially aggregated dissatisfaction indicator, PPD*^, based on the Universal Thermal Climate Index (UTCI) and incorporating a minimum spatial requirement for shade derived from existing cities' shading policies. The novel indicator separately accounts for thermal discomfort in both shaded and sunlit pedestrian areas. A simulated case study in a neighborhood in La Rochelle, France, evaluates six tree planting scenarios, with canopy cover ranging from 0% to 80%. Results indicate that a 20% canopy cover is a practical threshold for mitigating discomfort in moderate and warm climates. This methodology can also be extended to assess additional cooling strategies, such as evaporative systems, and provides valuable insights for optimizing cost-effective and sustainable urban adaptation measures
Évaluer le rapport des humains à la nature dans un cadre de jeu: Proposition et application d'un nouveau cadre conceptuel et de la méthode d'évaluation associée
No full textInternational audienceThe dualistic paradigm of human-nature relationship prevailing in Western societies, here referred to as classic modern Western (CMW) relationship to nature, has become a conceptual prison when faced with ecological crises. Simulation games can be useful artifacts for transforming a player's apprehension of such subject. Therefore, the research presented here is part of a thesis seeking to help one deconstruct its CMW relationship to nature by playing a simulation game. To achieve this, it is essential to be able to observe the presence and patterns of expression of the dimensions composing the CMW relationship within the game. However, to our knowledge, there is no such conceptual framework specific to games. Therefore, this paper aims to present for the first time a conceptual framework of the main dimensions of the CMW relationship, within a game frame, and to experience its evaluation method on players. The presented exploratory research crosses borders of scientific disciplines, spanning both human geography and design sciences, and drawing insights from other humanities. Starting with a multidisciplinary literature overview, this article describes the process and result of synthesizing the dimensions of the CMW relationship to nature. The conceptual framework obtained leads to a methodological approach, grounded in the case study My Spot of Sea, to observe these dimensions among players, considering design effects. Finally, results from applying this method to game sessions with middle school students are presented and discussed.Le rapport dualiste entre l’humain et la nature, dominant dans les sociétés occidentales — désigné ici comme le rapport occidental moderne classique à la nature (OMC, ou CMW en anglais) — constitue aujourd’hui une véritable prison conceptuelle face aux crises écologiques. Les jeux sérieux peuvent être des outils pertinents pour transformer la manière dont les joueurs perçoivent cette relation. La recherche présentée dans cet article s’inscrit dans le cadre d’une thèse qui vise à accompagner les individus dans la déconstruction de leur rapport OMC à la nature, à travers l’expérience d’un jeu sérieux.Pour ce faire, il est essentiel de pouvoir observer à l’intérieur même du jeu la présence et les modes d’expression des dimensions constitutives de ce rapport OMC. Or, à notre connaissance, il n’existe pas encore de cadre conceptuel spécifiquement conçu pour cette analyse dans le contexte ludique. Cet article propose donc, pour la première fois, un cadre conceptuel des principales caractéristiques du rapport OMC à la nature, adapté à une approche par le jeu, ainsi qu’une méthode d’évaluation expérimentée auprès de joueurs.Cette recherche exploratoire adopte une posture interdisciplinaire, à la croisée de la géographie humaine et des sciences du design, tout en s’appuyant sur des apports issus d’autres champs des sciences humaines. À partir d’une revue de littérature pluridisciplinaire, l’article retrace le processus de synthèse ayant permis de dégager les grandes caractéristiques du rapport OMC à la nature. Le cadre conceptuel ainsi élaboré donne lieu à une approche méthodologique appliquée au cas du jeu Mon lopin de mer. Cette approche permet d’observer les manifestations de ce rapport chez les joueurs, en prenant en compte les effets de design du jeu. Enfin, les résultats issus de l’expérimentation menée auprès d’élèves de collège sont présentés et discutés
Considérer pleinement les sols dans les processus de planification et d'aménagement: exemples réplicables de Nantes Métropole (France)
No full textInternational audienceSoils are often considered from a risk perspective (pollution, geotechnics) in the urban environment. This is particularly the case in redevelopment projects. Being part of the ecosystem, soils represent also a vital resource. They are indeed a major source of biodiversity (in and above). They also sink carbon, store and infiltrate water, transform organic matter and nutriments. In this frame, in addition to supporting human activities, soils contribute to eg. regulate the climate and the water cycle, support the production of biomass. Planning and (re)development processes must consider soils as resource and as risk, whatever the scale of approach. Several R&D projects on soils used Nantes Metropolis territory as a case study. The objective is to present some results corresponding to knowledge, methods and tools that can serve landscape architects.Excavated soils are a resource. They can be reused, from one site to another or through a valorisation platform. The TERRASS numerical tool helps to put producers and receivers (users) in contacts and to fulfil the traceability obligations. In case of low to moderate contamination, which is frequent in the urban environment, the local geochemical background serves to establish threshold values to facilitate the reuse of excavated materials at district to territorial scale . Soil refunctionalisation or construction can also be operated, using eg. excavated soils and organic waste. This can compensate for the scarcity of topsoil.Soil multifunctionality helps taking the soil resource into account in planning and development. The MUSE method considers four estimated indicators of soil ecological functions (carbon storage, biodiversity storage, infiltration capacity, agronomic value) at territorial scale, and their combination. The maps can be used to preserve some good or patrimonial soils or anticipate soil restoration needs. Methodological adaptations at project (eg Ris-Orangis ) to territorial scale (eg. Rennes Metropolis ) aim to gain precision. Larger sets of indicators and more detailed soil maps allow adapting their use according to their quality, including multifunctionality as well as contamination.Soil pollution risks are linked to different sources. Urban historical inventories map the former industrial and service activities potentially source of soil pollution, and can guide on associated potential pollutants. Anthropogenic deposits may also be a source of pollutants, according to the nature of materials they contain . Further research efforts are in progress within the GSEU and PERMEPOLIS projects. Agriculture, like market gardening, and green spaces maintenance may also have generated diffuse soil contamination with pesticides . That is why, soil contamination risk needs to be checked before any project. In this frame, the high demand for urban gardening appears as a real challenge needing a careful check of soil quality(16).Soils (including resource and risk) are fully considered in the DésiVille17 method to map their potential for desealing, additional development being in progress within the PERMEPOLIS15 project. Other inspiring examples exist at national to EU scale. The webtool in progress (SPADES18) aims to help the users (including landscape architects) to find the right soil concept/methods/tool to answer their needs in the planning, developments and/or design process.</p
Historicity in Organization Studies: Describing Events and Actuality at Borders of our Present
No full textInternational audienceAs soon as we go beyond the borders of our present and begin to explore remote pasts and futures, management and organization scholars are exposed to two dangers. The first is the exaggeration of continuities and anachronism about the past. The second is the projection of present ordinariness into the future. So how can we describe long-term processes of entrepreneurship, accounting, marketing, finance, information systems or innovation? This edited volume gathers a team of leading interdisciplinary team of scholars inspired by process philosophy, phenomenologies, and critical schools. After presenting issues, debates, and perspectives likely to inspire and guide historical description, the book moves to the concrete translation of this endeavor. Several examples of historical work in entrepreneurship, accounting, and organization studies are then used to show situations in which researchers have had to tackle this resonance between ontology and methodology in their historiography. It will be of great interest to scholars and students of management and organization studies. This books follows the 13th OAP workshop hosted by ESADE on June 2023
Introduction / Opening comments colloque international "Le Japon sonore : modernité, constructions sociales, rapports de force / Japan and sound: modernity, social constructs and power relations"
No full textVidéo colloque "Le Japon sonore : modernité, constructions sociales, rapports de force / Japan and sound: modernity, social constructs and power relations""Le Japon sonore : modernité, constructions sociales, rapports de force / Japan and sound: modernity, social constructs and power relations"14-16 novembre 2024Colloque international organisé par Jeremy Corral (UMRU 24140 D2IA, Université Bordeaux Montaigne) et par Chiharu Chûjô (EA 4186-IETT, Université Jean Moulin Lyon 3).Des recherches ethnographiques et historiques récentes sur le son ont montré que les pratiques de production et d’écoute sonores et musicales sont liées aux constructions sociales, notamment à la question de l’identité et aux rapports de force ; elles suggèrent de la sorte que la relation entre le son et la vie quotidienne doit être comprise à l’intérieur de contextes culturels spécifiques. Ainsi la dissémination globale des technologies et l’uniformisation des techniques de production et de médiation du son depuis l’époque moderne sont des phénomènes qui s’accompagnent d’actes de réappropriation et de réinterprétation de ce son. Interroger comment est fait, médiatisé et reçu le son, c’est dès lors mettre au jour une tension politique fondamentale entre ce qui peut être ramené au couple entendre et se faire entendre ; se renseigner sur des processus d’exploration du rapport à l’autre et d’affirmation psychique et sociale d’un soi et d’un espace individuel ou communautaire ; repenser les structures du pouvoir à travers les empreintes, et l’écologie desquelles elles dépendent, d’une forme transitoire.En suivant le questionnement ci-dessus, le colloque « Le Japon sonore : modernité, constructions sociales, rapports de force » a pour intention d’identifier des zones de frictions sociales qui potentiellement invisibles ou peu renseignées sont cependant proprement non muettes ; de scruter les dispositifs médiatiques et techniques de construction et d’expression par le son d’identités déterminées ; d’examiner de quelle manière le son se constitue comme un instrument de contrôle ou de résistance, de cohésion ou de dispersion des forces, d’unification ou de segmentation d’espaces, au sein des multiples trajectoires, internationales, nationales ou locales, qui accompagnent les changements relatifs à la société japonaise moderne et contemporaine
Des parcours scientifiques au féminin en Nouvelle-Aquitaine
No full textEquality between men and women is a recent issue in the French Republic. The principle was enshrined for the first time in 1946 in the preamble to theConstitution of the 4th French Republic. Since then, several texts have been adopted, including the Rixain law, which imposes a 40% quota for women among senior managers in large companies by 2030.Higher education is playing its part in this fight against inequality between men and women by by enacting a series of reforms from 2012 onwards, including the Fioraso law aimed at professional equality. Despite these advances and the apparent fairness of entrance examinations in the academic field, perceived as more neutral, inequalities persist in 2025, particularly in the scientific disciplines. Back in the early 2000s, Catherine Marry and Irène Jonas pointed out that ‘the academic world cannot escape the glass ceiling or the leaden sky’ (1). Twenty years on, what can we say about the situation in New Aquitaine?The aim of this document is to highlight the careers of the network's women researchers in the light of inequalities between men and women in higher education, particularly in the New Aquitaine region. Firstly, it will provide an overview of the situation of female based on data from the HR2S network, but also from the region's universities. It then transcribes ten interviews with women researchers from different disciplines academic status. Finally, a conclusion summarises the main findings of this study and the context in which these researchers are working today.La question de l’égalité entre les hommes et les femmes est une question récente dans la République française. Ce principe est inscrit et apparait pour la première fois en 1946 dans le préambule de la Constitution de la 4e République française. Depuis, plusieurs textes ont été adoptés, dont la loi Rixain, qui impose un quota de 40 % de femmes parmi les cadres dirigeantes des grandes entreprises d'ici 2030.L’enseignement supérieur prend sa part dans cette lutte contre les inégalités entre hommes et femmes en promulguant, à partir de 2012, une série de réformes, dont la loi Fioraso visant à renforcer l’égalité professionnelle. Malgré ces avancées et l’apparente équité des concours d’entrée dans le domaine académique, perçues comme plus neutres, les inégalités persistent en 2025, notamment dans les disciplines scientifiques. Dès le début des années 2000, Catherine Marry et Irène Jonas soulignaient déjà que « le monde académique n’échappe pas au plafond de verre ou au ciel de plomb » (1). Vingt ans plus tard, quel constat pouvons-nous faire en Nouvelle-Aquitaine ?Ce document a pour objectif de mettre en lumière le parcours des chercheuses du réseau à l’aune de ces inégalités entre femmes et hommes dans l’enseignement supérieur et particulièrement sur le territoire Néo-Aquitain. Dans un premier temps, il propose de dresser un panorama de la situation des chercheuses à partir des données du réseau HR2S, mais également issues des universités de la région. Ensuite sont retranscrits dix entretiens avec des chercheuses issues de différentes disciplines et statuts académiques. Enfin, une conclusion résume les principaux enseignements de cette étudeet le contexte dans lequel ces chercheuses exercent aujourd’hui
1619. L'autre naissance des États-Unis.
No full textInternational audienceEn 1619, deux navires corsaires vendent des captifs africains sur les rivages de la toute récente colonie anglaise de Virginie, en Amérique du Nord. Quatre siècles plus tard, en 2019, l’événement est commémoré aux États-Unis comme récit africain-américain des origines de la nation, un an avant les pèlerins du Mayflower, 157 ans avant la Déclaration d’indépendance.Ce moment ne peut être compris sans être inclus dans les circulations atlantiques des premières décennies du XVIIe siècle, dans un monde où les rapports de force entre puissances impériales sont reconfigurés, façonnant les connexions entre humains, marchandises, idées et capitaux.En ce début de XXIe siècle, alors que les luttes mémorielles se mondialisent, la construction et la promotion de cette date charnière constituent un bon observatoire des débats politiques et sociaux qui animent les États-Unis
Thermal stability and degradation of a low refractive index photo-crosslinkable adhesive
No full textInternational audienceIn some laser assemblies, optical components are glued on their metal mount using a photocrosslinkable adhesive. All these components are submitted to medium to high temperatures for several hours upon laser's operation time. The subsequent thermal stresses endured by the adhesive could lead to its degradation, alter thus the functioning of the assembly and impact the alignment of the laser, key issues in laser applications. This work focuses on the investigation and the modeling of the lifespan, the degradation in the face of thermal stresses, particularly those generated by a laser, and of the ageing of a photocrosslinkable adhesive, PC373HA. The thermal characterization is performed using ThermoGravimetric Analysis and allows for the development, the validation and the comparison of three models based on Arrhenius' law to estimate the lifetime of adhesives as a function of temperature. A temperature of 150°C is identified as a threshold to ensure limited degradation over the 15 hours requested for laser operation endurances. The Ozawa-Flynn-Wall model and the Kissinger-Akahira-Sunose model correctly reproduce PC373HA's thermal behavior submitted to different thermal scenarii (temperatures, heating rates…). Both show that the higher the temperature, the faster the degradation process, approximately 10 minutes at 220°C and 100 minutes at 180°C, much less than the required 15 hours. Besides, in the event of an incident with the laser, if the temperature exceeds 200°C for more than 10 minutes or 180°C for more than 100 minutes, corrective action should be taken, and the adhesive should be replaced. These models therefore provide fundamental information for laser applications and will allow the implementation of preventive solutions during use but also in case of incident
Functional traits of plant roots and Collembola determine their tri‐trophic interactions with soil microbes
No full textInternational audienceTraditionally, leaf litter has been recognized as the main driver of the soil food web, but more recently roots have been shown to play an important role in fuelling soil organisms. Root functional traits were shown to have direct effects on microbes and Nematoda, but many knowledge gaps remain such as the effects of root traits on Collembola. Here, in a microcosm experiment, we studied the tri‐trophic interactions between roots, microbes and Collembola in relation to 10 plant species individually. Eleven root traits were measured to test whether they have an influence on Collembola and microbe community structure and Collembola functional structure based on six traits. The interactions between microbes and Collembola were also tested. Our results show that plant species identity significantly influences the structure of Collembola communities, and this variation is primarily explained by root traits and microbial communities. Collembola feeding traits based on mandibular morphology were useful to identify top‐down control on microbial communities. Our study also suggests that root traits such as fine root length and root diameter modify Collembola–microbe interactions, hypothetically by modifying soil porosity. Overall, we obtained better results by looking at the whole system, rather than looking at bi‐trophic interactions. This illustrates the importance of a holistic approach when studying biotic interactions in soil ecosystems. Read the free Plain Language Summary for this article on the Journal blog.Traditionnellement, la litière de feuilles est vue comme une des principales sources de nutriments pour les réseaux du sol, mais des études récentes ont démontré que les racines contribuaient de façon importante à l'alimentation des organismes du sol. Il a été démontré que les traits fonctionnels racinaires ont un effet direct sur les microbes et les nématodes, mais plusieurs zones obscures demeurent, entre autres sur l'impact des racines sur les collemboles. Nous avons effectué une expérimentation en mésocosmes pour étudier les interactions tri‐trophiques entre les racines, les microbes et les collemboles en contact avec dix espèces de plantes individuellement. Onze traits racinaires ont été mesuré pour déterminer leur impact sur la structure des communautés de collemboles et de microbes, ainsi que sur la structure fonctionnelle des collemboles en ce basant sur six traits. Les interactions entre les collemboles et les microbes ont également été testées. Nos résultats montrent une influence de l'identité des plantes sur la structure des communautés de collemboles et que la variation entre les communautés peut s'expliquer par une combinaison des traits racinaires et des communautés de microbes. Les traits d'alimentation des collemboles, définis selon la morphologie de leurs mandibules, permettent d'identifier un contrôle trophique des communautés de microbes. Nos résultats suggèrent également que les traits comme la longueur des racines fines et le diamètre racinaire modifient les interactions collemboles‐microbes, probablement par leur impact sur la porosité du sol. Les résultats obtenus sont plus probants quand l'ensemble du système est regardé simultanément, plutôt qu'en décomposant ces composantes en interaction bi‐trophiques, démontrant l'importance d'une approche holistique pour étudier les réseaux trophiques du sol
Role of tidal range and coastline morphology on the evolution of two macrotidal sand spits
No full text(IF 1.9; Q1)International audienceThe present study examines the stratigraphy of two sandspits that both appeared and developed since the middle of the 17th century during the Little Ice Age. The Arçay spit is located along the macrotidal Atlantic coast in South‐West France with a maximum tidal range of 6.5 m. The Pointe du Banc in the English Channel, North‐West France, is located in a hypertidal coastal setting with a tidal range of up to 14 m. The evolution of the two spit systems has been compared using historical maps, ground penetrating radar data and facies analysis and geochronological data from sediment cores. The Pointe du Banc spit developed between 1650 and 1750 CE, in a dominant seaward direction while the main mode of construction of the Arçay spit was in a longshore direction. It is proposed that this difference relates to sediment supply and coastline morphology. At the Pointe du Banc spit, the large tidal range causes a long wind fetch and sustained aeolian sediment supply. Moreover, the spit is located at the apex of a large‐scale embayment where sediment transport from north and south converges. Combined, these factors result in a positive sediment budget and seaward shoreline progradation. At the Arçay spit, high wave obliquity results in a large littoral drift and sustained longshore spit construction. At both locations, low gradient shorefaces may have favoured a net landward‐directed sediment flux that supply sand to the foreshore