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Stopping criteria for nonlinear variational problems: iterative approach
No full textInternational audienceIn this paper, we present and study a stopping criteria based on a priori error estimate for nonlinear variational problems. We show that for nonlinear variational problems, the a priori error estimate is divided into two sub errors namely: the discretization error and the linearization error. We then used that representation to devise a stopping criteria that help to reduce the computational time. The methodology is applied to three problems and the numerical results demonstrate the superiority of the new approach
Design of an aerial PV cleaner
No full textInternational audienceThis paper focuses on designing a drone capable of cleaning solar panels. As renewable energy, particularly solar power, becomes increasingly important, the challenge of dust accumulation on solar panels is growing. Dust can significantly reduce the efficiency of solar panels by blocking sunlight. This study evaluates the effectiveness of drone-based cleaning methods through secondary research and develops a proof-of-concept PVcleaning drone. The project demonstrates the feasibility of using drones for this purpose and highlights areas for improvement
Assessment of the efficiency of dental excavation methods using laser speckle imaging
No full textInternational audienceThis paper introduces a novel application of the laser speckle technique in dentistry, focusing on assessing the efficiency of dental excavation methods used to remove decayed tooth structure. The aim is to evaluate the efficiency of two chemo-mechanical agents and the high-speed drill using the laser speckle technique, which offers objective, non-invasive, and real-time evaluation capabilities. Extracted human primary molars with active occlusal carious lesions were sectioned into three parts, with each part allocated to one of three groups: Group 1 (Brix3000®), Group 2 (Papacarie DUO®), and Group 3 (High-speed drill mechanical caries removal). Caries removal was performed using the designated agent or method for each group. After caries excavation, speckle imaging using a 632.8 nm laser was conducted. Additionally, SEM was used to acquire micro-photographs of the surface morphology of the treated samples. The findings reveal insights into the comparative efficiency of the three dental excavation agents and methods using the laser speckle technique. The speckle parameters extracted from speckle patterns generated by treated teeth provide valuable information for evaluating the performance of the excavation methods. The scanning electron microscopy images also offer detailed visual evidence to support the analysis. This paper demonstrates the potential of the laser speckle technique for assessing the efficiency of dental excavation methods. The objective, non-invasive, and real-time evaluation provided offers advantages over subjective visual assessment and manual measurements
Association between childhood maltreatment and obsessive-compulsive disorder comorbid with eating disorders: a cross-sectional study
No full textInternational audienceBackground: Obsessive-compulsive disorder (OCD) and eating disorders (ED) share common features, including the presence of obsessions and compulsions, and they often co-occur. Additionally, there is a significant comorbidity between ED and childhood traumatic experiences (CTE), as well as between CTE and OCD. Various biological and environmental factors have been proposed to explain the connection between ED, OCD, and CTE. This study explores the link between CTE and the comorbidity of ED and OCD, with the hypothesis that specific types of CTE may increase the risk of developing OCD in individuals with ED.Methods: Participants (N = 562) were enrolled at an eating disorder unit in Montpellier, France, between March 2013 and January 2020. The Childhood Trauma Questionnaire (CTQ), Eating Disorder Examination Questionnaire (EDE-Q), and Mini International Neuropsychiatric Interview (MINI) were used to evaluate childhood maltreatment, assess clinical characteristics associated with ED, and categorize participants into two groups: patients with and without OCD.Results: Bivariate analysis revealed that patients with comorbid ED and OCD had higher EDE-Q scores (p < 0.001), more anxiety disorders (p < 0.001), depressive disorders (p = 0.02), post-traumatic stress disorder (PTSD) (p < 0.001), and a higher incidence of sexual abuse (p < 0.001) and physical neglect (p = 0.04) compared to those without OCD. Multivariate analysis showed that the association between CTE and OCD was influenced by the presence of an anxiety disorder (p = 0.01) and a higher EDE-Q total score (p = 0.03), with a significant association with a history of sexual abuse (p = 0.04).Conclusions: This demonstrates that CTE increases the risk of comorbid OCD in ED patients, correlating with more clinically severe ED and a higher likelihood of anxiety disorders
Compte-rendu des journées d’études doctorales : Archives, Créations, Histoire, du 18 au 19 octobre 2023, à l'IMEC et la MRSH (Université de Caen)
No full textLe Carnet de la MRSH. Au cœur des sciences humaines et sociales et de l'interdisciplinarité. Un carnet de recherche proposé par HypothèsesCompte-rendu rédigé par Michael Issa El Helou, doctorant en cotutelle LASLAR (UR 4256) – Université de Caen Normandie et Laboratoire Lettres et Langues – Institut d’études scéniques et audiovisuelles, Université Saint-Joseph de Beyrouth.Ces journées d’études doctorales codirigées par Valérie Vignaux (professeure en études cinématographiques au département Arts du spectacle de l’université de Caen Normandie – LASLAR UR4256) et Ghada Sayegh (professeure associée à l’Institut d’études scéniques et audiovisuelles de l’université Saint-Joseph de Beyrouth – Laboratoire Lettres et Arts) ont rassemblé des chercheurs mais aussi des artistes venues de France et du Liban pour explorer le rôle des créations artistiques dans la compréhension de l’histoire. Ce colloque s’inscrit dans un programme PHC Cèdre 2023-2024.Lire le document https://mrsh.hypotheses.org/8389</a
MRI quantitative muscle characterization in children with X-linked hypophosphatemia
No full textInternational audienceIntroduction: Children with X Linked Hypophosphatemia (XLH) suffer from carential ricket, bone deformities and lameness. No previous study demonstrated a morphological distinction in muscles in these patients. The aim of this prospective study was to characterize, using Magnetic Resonance Imaging (MRI), the muscle morphology of pelvis, thigh and leg in children with XLH and to compare it with typically developed (TD) children.Hypothesis: We hypothesized that lower limbs muscles in children with XLH are different from TD children and could explain limp walking.Material and methods: Three-dimensional reconstructions of the muscles were performed in 11 patients with XLH and 15 TD children. Muscle lengths, sections and volumes were calculated and normalized with height and weight. Mean age was 10.Results: Lengths were all smaller in children with XLH except for the Medius/minimus gluteus muscles (p = 0.64). The difference seemed higher in muscles with a long tendinous part as semitendinosus (0.139 vs 0,164; p < 0.01). All volumes were significantly inferior in children with XLH. This preliminary study showed significant differences in muscle structures between patients with XLH and TD children.Discussion: Medius/minimus gluteus seemed to be particularly developed in children with XLH. Nevertheless it is not possible to conclude if it is related to XLH or a consequence of bone deformities
Optimal placement of multiple sources in a Mesh-type DC microgrid using Dijkstra's Algorithm
No full textInternational audienceThis research paper introduces an optimization methodology for the strategic electric sources’ placement at multiple positions in a DC islanded microgrid characterized by a mesh network, aiming to minimize line losses while considering minimal cable weight. The DC microgrid studied in this paper is composed of PV panels, batteries, a diesel generator, and 20 residential loads. Employing Dijkstra’s algorithm, a graph algorithm used in Google Maps, the study identifies the shortest path (resistance) between potential source nodes and various variable loads within a predefined electric distribution mesh network topology. This study focuses on active power considerations and offers valuable insights into the placement optimization of multiple sources’ positions in DC microgrid mesh networks. A key contribution of this paper lies in the ranking of source node positions based on minimal to maximal line losses, taking into consideration optimal cable weights, while using MATPOWER to validate sources’ ranking based on Dijkstra’s hypothesis. The research further includes a techno-economic study to assess the viability of sources’ placement at multiple positions within the mesh network, comparing it with the optimal placement scenario involving a single position for all sources. This methodology serves as a valuable resource for system designers and operators aiming to minimize line losses and optimize energy distribution in DC microgrids in a mesh topology
Working through multiple crises: the experience of psychotherapists and psychoanalysts in Lebanon
No full textBackground This research explores the impact of the COVID-19 pandemic on psychotherapists' practices and their ability to maintain a framework despite a shared reality with their patients. The specific focus in this article is on the Lebanese context, which is characterized by a series of crises including economic collapse, the COVID-19 pandemic, and the Beirut blast. The objective of this study was to examine how the destabilization of the meta-frame due to crises necessitates adaptations in theoretical knowledge, practice, and setting. Methods We conducted a qualitative study among a population consisting of mental health professionals, which were recruited in multiple countries through associations and societies of psychologists, psychotherapists, and psychoanalysts. Data was collected using semi-structured individual interviews. The interviews were analyzed using interpretative phenomenological analysis (IPA), which allowed for a dynamic exploration of the participants' experiences. A total of 44 participants were interviewed, with 15 interviews specifically focusing on Lebanese psychoanalysts and psychotherapists. Results Our study revealed four superordinate themes: (1) the strained frontiers; (2) the cumulative traumatic reality and its impact; (3) A challenged professional identity; (4) The creativity stemming from collective trauma . Conclusions Our results highlight the insecurity caused by external reality infiltrating the therapeutic setting. Online therapy allowed for continued work, but uncertainty about the online environment's impact on therapeutic relationships was observed. The study underscores the importance of adaptability, containment, and support for therapists navigating crises, particularly in the online setting
Effect of Apical Preparation Size and Preparation Taper on Smear Layer Removal Using Two Different Irrigation Needles: A Scanning Electron Microscopy Study
No full textInternational audienceObjectives: The aim of this study was to determine the effect of apical preparation size and preparation taper on smear layer removal using a metallic needle and a new polymer needle (IrriFlex, Produits Dentaires SA “PD,” Vevey, Switzerland).Materials and Methods: One hundred and eight single-rooted teeth with one canal were randomly divided into four groups according to the preparation and irrigation needle used: G1—30, 0.04 and IrriFlex (n = 25); G2—25, 0.06 and IrriFlex (n = 25); G3–30, 0.04 and metallic needle (n = 25); and G4—25, 0.06 and metallic needle (n = 25). All groups received the same final irrigation protocol and sonic activation. Each tooth was sectioned and observed under a scanning electron microscope (SEM).Statistical Analysis: Data were statistically analyzed by using one-way and two-way analysis of variance on ranks with a significance level at p = 0.05.Results: For all groups, there was significantly higher smear layer in the apical third (p < 0.001) compared with the coronal and middle thirds. The 25, 0.06 preparation demonstrated better cleaning efficiency than the 30, 0.04 preparation throughout the canal when irrigated with a metallic needle; however, there were no significant differences in the middle and apical thirds when IrriFlex was used. There were also no differences of smear layer removal between G1 and G3 and G2 and G4 in the coronal part. In the middle and apical parts, G1 showed better elimination of smear layer compared with G3. There were slight differences in the middle third between G2 and G4, while G2 showed less cleaning efficiency compared with G4 in the apical third (p = 0.022).Conclusion: All groups showed less smear layer in the middle and coronal thirds of the canal compared with the apical third. The 25, 0.06 preparation was more effective in removing smear layer compared with the 30, 0.04 preparation. IrriFlex improved irrigation in the 30, 0.04 preparation, while its efficacy was less evident in the 25, 0.06 preparation
Full discretization of the time dependent Navier–Stokes equations with anisotropic slip boundary condition coupled with the convection–diffusion–reaction equation
No full textInternational audienceIn this article, we consider the time dependent convection-diffusion-reaction equation coupled with the Navier-Stokes system subject partially to anisotropic slip boundary condition. We formulate the weak problem, and construct the weak solutions by using the approximation approach combined with some compactness results. The discrete solution is constructed by using the finite element method in space and the implicit Euler scheme in time. The convergence of the discrete solution is examined thanks to a priori errors estimation, and the rate of convergence is obtained. We propose an iterative scheme and investigate its convergence using the weak convergence approach. Finally, numerical investigations are performed to validate the theoretical results presented