HAL Université de Savoie
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Current tectonic deformation of the Sulaiman Range (Pakistan) with InSAR
No full textInternational audienceSUMMARY In Pakistan, the relative displacement between the Indian and Eurasian plates is accommodated by a left-lateral transpression zone comprising the Chaman and Ghazaband faults and the Sulaiman Range. The current tectonic deformation of the Sulaiman Range is known only from some focal mechanisms and a few neotectonic studies. In this study, we propose an Interferometric Synthetic-Aperture Radar (InSAR) quantification of current tectonic deformation using the Sentinel 1 satellite. Velocity maps for the ascending and descending tracks enabled us to locate active faults affected by creep: the Harnaï and Kingri strike-slip faults, and the Gwal–Bagh thrust. We propose a numerical simulation that considers these faults as well as the level of detachment fold-and-thrust belt. Our results suggest the existence of out-of-sequence deformation along the Gwal–Bagh thrust, creep along the Harnaï and Kingri strike-slip faults, and slip along the décollement of the Sulaiman Range. The eastern part of the Sulaiman Range is characterized by a partitioning of the deformation with a left-lateral strike-slip along the N170° Kingri fault and an eastward thrust. In contrast, the western part is characterized by north–south compressive deformation associated with right lateral strike-slip on the Harnaï N120° fault. Modelling of the coseismic deformation of the 2021 October 21 earthquake shows that this earthquake occurred on a fault with a ramp geometry, but affected by a strike-slip motion
Numerical and experimental study of an underground thermal energy storage system coupled with asphalt solar collector and heat pump
No full textInternational audienceAbsorption chillers are attractive because they use natural refrigerants and can be powered by low-grade heat sources. Among the commercially available working fluids, the most common one, H2O-LiBr, has a critical drawback associated with the crystallization of the solution at low temperatures and high absorbent concentrations. This limitation restricts the operating range of these systems, especially when they are air-cooled or used as heat pumps. Additives can be used in H2O-LiBr to reduce the crystallization temperature by improving the solubility of LiBr in the solution. However, they often present disadvantages such as the requirement of a rectifier, and a negative impact on heat and mass transfer. Ionic Liquids (ILs) used as additives represent an alternative to overcome these drawbacks. In the present study, 6 % of [DMIM][Cl] by mass in absorbent (LiBr + [DMIM][Cl]) is added as an anti-crystallization additive to study its effect on the experimental behavior and crystallization limit of a H2O-LiBr single-effect bi-adiabatic absorption chiller prototype. Results of H2O-LiBr and H2O–(LiBr + [DMIM][Cl]) were compared for the individual heat transfer elements and the global system COP. The results show a decrease in the crystallization temperature using H2O–(LiBr + [DMIM][Cl]), which extended the operating range of the prototype. A decrease of 15 °C in crystallization temperature was found for H2O–(LiBr + [DMIM][Cl]) compared to H2O-LiBr at an absorbent mass of 65 %. Crystallization impeded the operation for H2O-LiBr at the highest driving temperature (100 °C) and lowest cold source inlet temperature (9 °C), whereas no crystallization was observed at same operating conditions for the (LiBr + [DMIM][Cl]) solution. Under the tested conditions, the addition of the IL as additive increased the chiller operating range without the requirement of a rectifier and with a negligible impact on the cooling capacity and thermal COP
Sustainable wafer-scale integration of epitaxial ZnO on silicon for piezoelectric devices
No full textInternational audienceTo sustainably support the ongoing energetic transition, we need functional metal oxides capable of converting energy, and produce storage, and sensing devices. However, these materials suffer from a high economic cost of manufacturing, and their production in a sustainable way is, to date, a milestone. Additionally, the technical challenges, such as scalability and integration of silicon for industrial processing using microelectronic technologies, impose strict conditions for the entire materials process. In this work, we engineer α-quartz virtual substrates up to 4 inches facilitating the large-scale and sustainable integration of multifunctional epitaxial ZnO metal oxide microwire films on silicon. These materials are exclusively manufactured on silicon using solution chemistry, providing single-chip solutions that can meet strict economic constraints for developing sustainable devices at a lower cost. Through this integrative technology, we demonstrate the microfabrication of epitaxial (110)ZnO/(100)α-quartz/(100)silicon piezoelectric membrane resonators at the wafer-scale with potential applications in energy conversion and sensing. We combined four dimensional (4D)-STEM diffraction technology and Piezoelectric Force Microscopy (PFM) to establish a correlation between out of plane crystalline strain and piezoelectric response in epitaxial (110) ZnO at the microscale. Finally, we proved the fabrication of 800 nm thick (110) ZnO suspended membranes that can be transferred to flexible substrates, making them suitable for flexible devices
A new parameter in the era of robotic total knee arthroplasty: Coronal alignment at 90° of flexion impacts clinical outcomes
No full textInternational audienceAbstract Purpose Alignment strategies in total knee arthroplasty (TKA) have predominantly emphasized coronal alignment in extension, with minimal focus on dynamic alignment during flexion. This study aims to identify the predictors of the intraoperative robotic hip–knee–ankle angle at 90° of flexion (rHKA‐90F) and assess its clinical significance in postoperative outcomes, proposing that rHKA‐90F may be a critical factor in enhancing functional results in TKA. Methods A retrospective analysis was conducted on 180 patients with varus deformity undergoing robotic‐assisted TKA under the functional alignment principles. Clinical outcomes were assessed using the Knee Society Score (KSS), Forgotten Joint Score (FJS‐12) and Kujala Anterior Knee Pain Scale (AKPS) score. Predictors for final rHKA‐90F and its intraoperative changes were identified using multiple linear regression models. Initial and intraoperative robotic measurements were also analyzed. Results Significant predictors of the final rHKA‐90F included femoral rotation, tibial varus/valgus alignment, initial rHKA‐90F and the final robotic axis in extensions. Patients with a final rHKA‐90F ≥ 5° of varus demonstrated superior KSS function and KSS knee compared to those with a final rHKA‐90F between 0° and 4° of varus. Furthermore, patients with intraoperative changes of rHKA‐90F > 2.5° neutralization (varus reduction or with a valgus value) achieved better FJS and AKPS score. Conclusions This study highlights the clinical relevance of rHKA‐90F as an intraoperative tool in robotic knee arthroplasty, emphasizing the need to balance the correction of varus deformity with the maintenance of slight varus alignment in flexion. Personalized alignment strategies tailored to patient‐specific anatomy and kinematics are crucial to optimizing outcomes. There is still a need for future research on the long‐term effects of dynamic alignment. Level of Evidence Level III
Use of DFOS to monitor crack opening evolution in FRCM-strengthened reinforced concrete structures
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CULTURAL TOURISM IN THE ERONGO MOUNTAINS (NAMIBIA): WHAT ROLE FOR LOCAL COMMUNITIES IN ROCK ART TOURISM?
No full textInternational audienceSituated 160 kilometers northwest of Windhoek, the Erongo Massif is a granitic formation, with its highest point, Mount Erongo, reaching an altitude of 2,350 meters. The massif is distinguished by its rich geological history (linked to the geological evolution of Gondwana) as well as its biological diversity, including several endemic species. It also hosts several thousand rock art sites, attributed to the San hunter-gatherer populations who inhabited the area long before the onset of German colonization. Among the numerous rock art sites in these mountains, only a few are allowed for visitor access: several sites on Omandumba West and East farms, Phillips Cave on Ameib, Paula Cave on Okapekaha, and several sites on communal lands around Tubusis. Unlike Twyfelfontein or the Brandberg mountains with the famous “White Lady” site, the rock art sites of the Erongo Massif are not managed by the state, and the guides are not affiliated with the National Heritage Council. The promotion of these sites as tourist attractions is influenced not only by land tenure but also by the way in which private owners and local communities work together. Analyzing these different cases allows for an exploration of the roles and contributions of various stakeholders.The aim of this paper is to investigate the issues surrounding the tourism development of rock art sites in the Erongo Mountains (Namibia) from the perspective of stakeholder dynamics and local community involvement. By focusing on the main rock art sites developed for tourism, we will examine the existing forms of tourism and types of visits, as well as the actors involved and the benefits for local communities. This analysis will lead to an examination of the modes of collaboration between Namibian landowners of German descent and local Namibian communities of various origins. Finally, we will conclude with recommendations aimed at improving relations between these two main categories of stakeholders, with a view toward sustainable and equitable tourism development. This study is based on several field campaigns carried out in 2022, 2023 and 2024. These field campaigns a combined observation phases with semi-structured interviews involving various stakeholders engaged in these tourism dynamics. "This research was funded in whole or in part by the Agence Nationale de la Recherche (ANR) under the project COSMO-ART, ANR-21-CE27-0011. In the interest of open-access publication, the author/rights holder applies a CC-BY open-access license to any article/manuscript accepted for publication (AAM) resulting from this submission. Also, this work is supported by the French National Research Agency in the framework of the " France 2030 " program (ANR-15-IDEX-0002) through the LabEx ITEM, research project GeoExTour.
Investigating the velocity of magmatic intrusions and its relation with rock fracture toughness : insights from laboratory experiments and numerical models
No full textInternational audienceA key question for those who study magmatic and volcanic processes is: ‘How fast can a magmatic intrusion travel?’ Observations and models indicate ranges between 10−2 and 1 m s−1 depending on several parameters, including magma buoyancy (or driving pressure), viscosity and rock fracture toughness (Kc). However, Kc values are difficult to constrain, as effective values inferred from large magmatic intrusions may be 2–3 orders of magnitude larger than measured values from small laboratory samples. This can be attributed to non-elastic processes that dissipate energy at different rates, depending on factors such as the fracture dimension and fracture propagation velocity. Here, we aim to investigate this aspect and provide a scheme for estimating effective fracture toughness values (Keff) by considering fluid-filled fracture processes across different ranges of propagation velocities. To do so, we combine (i) analogue laboratory experiments involving the propagation of oil- and air-filled cracks within a solidified gelatin block, with (ii) numerical simulations, reproducing the crack shape and velocity and providing an estimate of the energy dissipated by the fluid flow between the crack walls. We show that even at the scale of our experiments, Keff values exhibit significant variations spanning over an order of magnitude. Over the velocity ranges relative to our two sets of experiments, we identify two empirical relations for an effective, velocity-dependent fracture energy (∆Ef (v)), showing that when such an empirical relation is implemented into the numerical model, it improves the prediction of velocities and velocity variations. Following a similar procedure and building empirical relations for ∆Ef (v) or Keff(v) at the scale of magmatic intrusions would improve predictions on dyke propagation velocities in the crust. In order to do so, a considerable amount of observations on the geometry and propagation velocity of magmatic dykes should be gathered
Observation of a new charmed baryon decaying to
No full textInternational audienceThe spectrum is investigated using proton-proton collisions at a center-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.4fb, collected by the LHCb experiment during 2016--2018. Four states are observed with high significance, and their masses and widths are measured to be \begin{align*}m[\Xi_c(2815)^{+}] &= 2816.65 \pm 0.03 \pm 0.03 \pm 0.23 ~\text{MeV},\\\Gamma[\Xi_c(2815)^{+}] &= 2.07 \pm 0.08 \pm 0.12~\text{MeV},\\[5pt] m[\Xi_c(2923)^{+}] &= 2922.8 \pm 0.3 \pm 0.5 \pm 0.2~\text{MeV},\\\Gamma[\Xi_c(2923)^{+}] &= 5.3 \pm 0.9 \pm 1.4~\text{MeV},\\[5pt] m[\Xi_c(2970)^{+}] &= 2968.6 \pm 0.5 \pm 0.5 \pm 0.2~\text{MeV},\\\Gamma[\Xi_c(2970)^{+}] &= 31.7 \pm 1.7 \pm 1.9~\text{MeV},\\[5pt] m[\Xi_c(3080)^{+}] &= 3076.8 \pm 0.7 \pm 1.3 \pm 0.2~\text{MeV},\\\Gamma[\Xi_c(3080)^{+}] &= 6.8 \pm 2.3 \pm 0.9~\text{MeV}.\end{align*} where the uncertainties are statistical, systematic, and due to the limited precision on the mass, respectively. The baryon is observed for the first time, and is consistent with being the isospin partner of the previously observed state. Most of the measured parameters are more precise than existing world averages
A comprehensive building-wise rooftop photovoltaic system detection in heterogeneous urban and rural areas: application to French territories
No full textInternational audienceWith the rapid expansion of Rooftop Photovoltaic (RPV) systems, accurately identifying the location of these installations has become essential for urban planning, grid management, and socio-economic analysis. However, existing European datasets of RPV systems are often limited in both spatial coverage and precision, especially in regions with diverse architectural styles. This study presents a novel methodology for identifying RPV systems by employing a convolutional neural network (CNN) trained on high-resolution aerial imagery and building registry data. Alternatively to traditional tile-based methods, we propose a building-by-building approach, ensuring that each building is individually assessed. The model was trained and validated on five French departments representing a variety of roofing materials and urban typologies. It demonstrates a high correlation between predicted and registered RPV systems, though detection performance varies with roofing materials—achieving better accuracy on tiled roofs than slate roofs. When applied to the entire metropolitan French territory, the model processed images of more than 40 million buildings, identifying approximately 600,000 RPV systems. The results’ accuracy is evaluated, taking into account factors such as data quality and local urban characteristics. All data and the model are publicly available for further research and applications
Accompagnement du changement au sein de la ville de Paris : étude de l’influence d’innovations managériales sur la performance des managers et des agents et leur Qualité de Vie au Travail
No full textNational audienceAccompagnement du changement au sein de la ville de Paris : étude de l’influence d’innovations managériales sur la performance des managers et des agents et leur Qualité de Vie au TravailLa demande sociétale et le rapport au travail évoluent. Les travailleurs souhaitent davantage participer et expriment de plus en plus leurs besoins de confiance, de sens, de reconnaissance et de considération (Achte et al., 2010 ; Caillé et al., 2020 ; Verrier & Bourgeois, 2016). Ces mutations impliquent les organisations publiques à repenser leurs modes managériaux pour répondre à la fois aux enjeux économiques et fonctionnels et à la fois à ces enjeux sociaux (Autissier et al., 2016). Bien plus que des gestionnaires, face à ces transformations managériales les managers d’aujourd’hui voient alors leurs pratiques évoluer et se transformer afin de s’adapter et de répondre aux besoins émergents des travailleurs (Caillé & Jeoffrion, 2020 ; Verrier & Bourgeois, 2016). Ces managers sont confrontés à des problématiques et à des enjeux importants, ils représentent une clé de voûte essentielle pour l’organisation fonctionnelle des équipes, la traduction des décisions stratégiques en objectifs opérationnels et l’atteinte des résultats. Leur accompagnement devient alors primordial (Desmarais, 2008).Le projet de recherche est rattaché à la Mission Management de la DRH qui a pour mission de promouvoir la culture managériale de la collectivité et de développer des dispositifs afin d’accompagner et de former les 6000 managers parisiens aux enjeux de transformations. Face aux enjeux sociaux et aux problématiques que vit la Ville de Paris, l'objectif pour la DRH est de co-construire un nouveau modèle managérial afin de s’orienter vers des modes de fonctionnements plus sobres et d’ancrer des pratiques d’accompagnement, ayant pour but de protéger et préserver les ressources, dans le mode de fonctionnement de la Ville de ParisCette thèse CIFRE en psychologie du travail et des organisations est une recherche-action ayant mis en place une méthode de recherche mixte, systémique et participative. Plusieurs méthodes de recueil de données ont déjà été réalisées : analyses lexicométriques, entretiens individuels, questionnaire quantitatif avec échelles de mesure scientifiquement validées, questionnaire qualitatif. Deux axes structurent la thèse. D'un côté, le premier a pour but d'identifier les effets des nouvelles pratiques managériales sur la qualité de vie au travail et la qualité de service public. D'un autre côté, les dispositifs d'accompagnement de la Mission Management offrent pour les managers des ressources bénéfiques à l'exercice de leur fonction et permettent de véhiculer ces nouvelles intentions managériales (Hobfoll, 2001, 2004). Etant en manque de données objectives sur le sujet, le deuxième objectif a alors pour but d'identifier les apports et les effets des dispositifs d'accompagnement pour les managers et leurs équipes. Le lien entre ces deux axes repose sur une boucle vertueuse fondée sur l'acquisition et la redistribution des ressources, qui facilite le changement où l’amélioration des compétences managériales se répercute sur la qualité de vie au travail des agents et la qualité du service rendu. La synergie entre ces deux objectifs est donc essentielle pour garantir la durabilité du modèle managérial