Portail HAL de l'Université du Littoral Côte d'Opale
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Atomic Structure and Dynamics of Unusual and Wide‐Gap Phase‐Change Chalcogenides: A GeTe 2 Case
No full textInternational audienceBrain‐inspired computing, reconfigurable optical metamaterials, photonic tensor cores, and many other advanced applications require next‐generation phase‐change materials (PCMs) with better energy efficiency and a wider thermal and spectral range for reliable operations. Germanium ditelluride (GeTe 2 ), with higher thermal stability and a larger bandgap compared to current benchmark PCMs, appears promising for THz metasurfaces and the controlled crystallization of atomically thin 2D materials. Using high‐energy X‐Ray diffraction supported by first‐principles simulation, the atomic structure in semiconducting pulsed laser deposition films and metallic high‐temperature liquids is investigated. The results suggest that the structural and chemical metastability of GeTe 2 , leading to disproportionation into GeTe and Te, is related to high internal pressure during a semiconductor–metal transition, presumably occurring in the supercooled melt. Similar phenomena are expected for canonical GeS 2 and GeSe 2 under high temperatures and pressures
Cyclogenesis in the Tropical Atlantic: First Scientific Highlights from the Clouds–Atmospheric Dynamics–Dust Interactions in West Africa (CADDIWA) Field Campaign
No full textInternational audienceDuring the boreal summer, mesoscale convective systems generated over West Africa propagate westward and interact with African easterly waves, and dust plumes transported from the Sahel and Sahara by the African easterly jet. Once off West Africa, the vortices in the wake of these mesoscale convective systems evolve in a complex environment sometimes leading to the development of tropical storms and hurricanes, especially in September when sea surface temperatures are high. Numerical weather predictions of cyclogenesis downstream of West Africa remains a key challenge due to the incomplete understanding of the clouds–atmospheric dynamics–dust interactions that limit predictability. The primary objective of the Clouds–Atmospheric Dynamics–Dust Interactions in West Africa (CADDIWA) project is to improve our understanding of the relative contributions of the direct, semidirect, and indirect radiative effects of dust on the dynamics of tropical waves as well as the intensification of vortices in the wake of offshore mesoscale convective systems and their evolution into tropical storms over the North Atlantic. Airborne observations relevant to the assessment of such interactions (active remote sensing, in situ microphysics probes, among others) were made from 8 to 21 September 2021 in the tropical environment of Sal Island, Cape Verde. The environments of several tropical cyclones, including Tropical Storm Rose, were monitored and probed. The airborne measurements also serve the purpose of regional model evaluation and the validation of spaceborne wind, aerosol and cloud products pertaining to satellite missions of the European Space Agency and EUMETSAT (including the Aeolus, EarthCARE, and IASI missions)
The Basketball Show in The North of France : when The NBA Globalized Culture meets The Local Carnival Culture
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Bedforms and Sedimentary Features Related to Water-Depth Variations in a Sandy Tidal-Flat Environment
No full textInternational audienceThis study highlighted the variability of a wide sandy macrotidal coastal system on short timescales. Changes in water depth and exposure length were the main drivers of this variability. In the study area, the coastal system consists of three units: a lower ridge-and-runnel beach, a 1000-m-wide tidal flat, and a sandy backshore. This research is based on sedimentary features that can record physical forces, especially the bedforms at the beach surface, and their relationship with beach gradient, exposure length, and changing water depth, according to tidal, weather, and marine conditions. It also demonstrated the ability of scanning electron microscope analysis of quartz grain microtextures to indicate the level of marine and eolian energy in the coastal system. The widespread wave and current sand ripples on the tidal flat showed great variability in time and space. A minimum water depth of 0.30 to 0.50 m was required for their development. The role of wind-induced waves and the frequent interference of tidal, wave, and wind forcing mechanisms are emphasized. The development of some complex sand ripples extended over a complete lunar tidal cycle. Wind-generated sand ripples were observed only on the backshore. Their absence on the tidal flat, despite the high level of eolian energy attested by quartz microtextures, and the poor development of dunes on the backshore are explained by factors impeding eolian sand transport at the beach surface such as extreme fetch segmentation and possible shell armoring of the beach surface during dry periods. This study demonstrated the short-term variability of the beach morphology as opposed to the long-term stability of the coastal system as a whole, in which the ultradissipative tidal flat, characterized by limited sand supply, low wave energy, and high but inefficient wind energy, plays a key role
L'influence de la digitalisation des relations juridiques sur le droit international privé : vers un changement de paradigme ?
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Exploring relational norms in exporter-importer product innovation co-development : A qualitative study
No full textInternational audienceThis research investigates the role of relational norms in facilitating importers' engagement in product innovation co-development with exporters. Through a qualitative approach, we conducted interviews with top managers of small and medium-sized enterprises (SMEs) involved in exporting activities in France. Guided by the theoretical framework of Relational Exchange Theory (Macneil, 1980; Dwyer et al., 1987), our study uncovers the significant potential for successful product innovation co-development when importers actively contribute as knowledge sources and co-developers. Additionally, we highlight the importance of cooperation, continuity expectations, and equity norms as external factors that shape the co-development process of new products between exporters and importers. By comprehending and embracing these relational norms, exporters can strengthen their collaborative endeavors with importers and effectively drive the co-development of innovative products
Emerging Technological Advances in Improving the Safety of Muscle Foods: Framing in the Context of the Food Revolution 4.0
No full text1International audienceTo address the issues related to high perishability and limited shelf life of food proteins from muscle origin, different innovative processing, and preservation techniques, as well as analytical methodological approaches have been developed to meet environmental challenges and consumer demand for food of high quality and sustainable production supported by circular economy principles. This development has been enhanced and increased during the ongoing age of the fourth industrial revolution (Industry 4.0), which has been gaining momentum since 2015, coming up with a range of automated and digitized technologies. This review provides an updated overview of the recently developed thermal and nonthermal processing and preservation technologies, along with selected advanced analytical techniques used in the industry of muscle foods. Particular attention has been given to Industry 4.0 technologies and their role in achieving smart production with high automation and digitalization rates. As in other industry sectors, technology breakthroughs are reshaping the food industry, including the muscle food sector. Emerging technologies, such as pulsed electric field, high-pressure processing, ohmic heating, nanotechnology, advanced mass spectrometry and hyperspectral imaging sensors are among the key elements in the current food revolution 4.0. Although Industry 4.0 offers countless possibilities, more studies are still needed to capture its full potential and further harness its technologies to solve current challenges and move forward toward Industry 5.0
Responsabilités et Indemnités: En matière d'absentéisme
No full textInternational audienceDans notre République progressivement gagnée par ‘’le retour à l’autorité’’, les situations d’absentéisme entraîneront bientôt une sévérité certaine. Ainsi, du point de vue pécuniaire, sans doute s’ensuivra-t-il plus souvent un appauvrissement du personnel qui manquerait à son devoir d’assiduité au poste de travail.Concrètement, à son manque à gagner en aides et indemnités publiques (ou sociales), pour maladie et autres, se rajoutera une charge de dommages-intérêts en vue de l’indemnisation des victimes de l’absentéisme déploré. Ces dernières sont notamment l’employeur de l’absentéiste, les clients ou les usagers de celui-là, de même que ses partenaires économiques.Bref, les travailleurs actionnant leur droit d’arrêt-maladie, de retrait, de grève, de démission, ainsi que ceux sans excuse (valable) d’absence, risquent davantage d’en subir des retombées financières ; d’ailleurs, outre la confrontation à d’éventuelles sanctions disciplinaires
Potential of cyclodextrin-based formulations of Rosmarinus officinalis essential oils in the control of the date moth Ectomyelois ceratoniae (Pyralidae)
No full textInternational audienceRecently essential oils (EOs) encapsulation is experiencing growing applications in agricultural and agri-food sector. Encapsulation is reported as safe environmental technology leading to a reduction of conventional insecticides use. This study concerns the assessment of fumigant toxicity and persistence of Rosmarinus officinalis EO encapsulated in two cyclodextrins β-CD and HP-β-CD against larvae of the date moth, Ectomyelois ceratoniae. The retention capacity, encapsulation efficacy, loading capacity and release behavior of the two inclusion complexes were investigated. Results showed that two studied CDs had in important retention capacity. Additionally, the encapsulation within CDs delayed the release of rosemary EO bioactive components; which explains the effectiveness of the encapsulated rosemary EO in CDs against E. ceratoniae fifth instars larvae. Furthermore, the encapsulation in the two CDs improved the persistence of the insecticidal toxicity. This study supports the use of cyclodextrins, mainly HP-β-CD, in the date industry for the control of insect pests
Ocean climate and hydrodynamics drive decadal shifts in Northeast Atlantic dinoflagellates
No full textInternational audienceAbstract The abundance of large marine dinoflagellates has declined in the North Sea since 1958. Although hypotheses have been proposed to explain this diminution (increasing temperature and wind), the mechanisms behind this pattern have thus far remained elusive. In this article, we study the long‐term changes in dinoflagellate biomass and biodiversity in relation to hydro‐climatic conditions and circulation within the North Atlantic. Our results show that the decline in biomass has paralleled an increase in biodiversity caused by a temperature‐induced northward movement of subtropical taxa along the European shelf‐edge, and facilitated by changes in oceanic circulation (subpolar gyre contraction). However, major changes in North Atlantic hydrodynamics in the 2010s (subpolar gyre expansion and low‐salinity anomaly) stopped this movement, which triggered a biodiversity collapse in the North Sea. Further, North Sea dinoflagellate biomass remained low because of warming. Our results, therefore, reveal that regional climate warming and changes in oceanic circulation strongly influenced shifts in dinoflagellate biomass and biodiversity