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Framework for a retrospective analysis of operating room schedule execution
No full textInternational audienceThe execution of an operating room schedule is constantly disrupted, which can decrease the initially targeted performance. Online operational management (OnOM), which oversees daily activity, can reduce the deviations caused by disruptions between the initial schedule and the performed schedule. To support this process and encourage continuous improvement, we suggest a framework for analysing schedule execution in retrospect. The objectives are twofold: 1) to identify deviations and determine their root causes; and 2) to assess the relevance of the decisions made to reduce these deviations. This approach relies on a logbook to gather qualitative data on disruptions, and a dashboard to objectify the situation with computed indicators. We present an example of a schedule execution analysis in an anonymised French General Hospital
Ultrasonic welding of CF/PEEK composites: Influence of welding parameters on interfacial temperature profiles and mechanical properties
No full textInternational audienceThis work focuses on ultrasonic (US) welding of CF/PEEK composite containing a PEI layer at the interface. Welding time, load and amplitude are defined as the welding parameters. The influence of each parameter is assessed by temperature measurement and mechanical tests on US welding specimens. 80-μm diameter thermocouples are integrated into the interfacial polymer layer for in-situ monitoring of the maximum temperature profile during the welding phase. Only welding time and welding load have an influence on both temperatures and lap shear strengths (LSS). The highest LSS are close to 50 MPa, and the temperature achieved in those cases is around 580◦C. Interfacial fractures occur in both PEI and PEEK. PEI-based fracture is mostly brittle whereas PEEK-based fracture is a competition between brittle and ductile fracture. Finally, a fracture within the PEI/PEEK blend can occur. Raman spectroscopy is effectively used to quantify the thickness of this blend zone, it is about 0.075 mm
Anti-windup-like Compensator Synthesis for Discrete-Time Quantized Control Systems
No full textInternational audienceThis paper addresses the problem of designing an anti-windup like compensator for discrete-time linear control systems with quantized input. The proposed compensator provides a correction signal proportional to the quantization error that is fed to the controller. The compensator is designed to ensure that solutions to the closed-loop systems converge in finite time into a compact set containing the origin that can be tuned by the designer. A numerically tractable algorithm with feasibility guarantees is provided for the design of the compensator. The proposed results are illustrated on an academic example and an open-loop unstable aircraft syste
Hydrogen-Rich and Clean Fuel Gas Production from Co-pyrolysis of Biomass and Plastic Blends with CaO Additive
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Correlation between microstructure heterogeneity and multi-scale mechanical behavior of hybrid LPBF-DED Inconel 625
No full textInternational audienceThe two additive manufacturing processes Powder Bed Fusion (LPBF) and Directed Energy Deposition (DED) have different geometrical resolutions and production flexibilities, making their hybridization attractive. LPBF microstructure displays fine grains, with weak preferential crystal orientation. DED generates a highly textured and inhomogeneous microstructure with equivalent grains diameters ranging from a few micrometers to over a millimeter. The microstructure of the hybrid LPBF-DED sample is the addition of these two microstructures with an interface free from cracks or particular pores. The effect of this strong heterogeneity of the hybrid microstructure on mechanical behavior is analyzed by tensile tests instrumented with local strain gauges, others using digital image correlation method and finally on samples tested inside a scanning electron microscope. This multi-scale characterization showed that the difference in the elastic properties causes the localization of the strain field and generates a plastic incompatibility at the interface. An optimized heat treatment leads to isotropic and homogeneous hybrid microstructure, with a larger DED grain size. It leads to identical plasticity mechanisms during tensile tests and lowers the strain gradient around the interface
Proposition d’un outil d’aide à la décision pour la régulation desblocs opératoires
No full textNational audienceLa performance d’un hôpital est fortement liée à la performance de son bloc opératoire. La communauté scientifique s’intéresse particulièrement à la construction du programme opératoire (PO). L’étape d’exécution du programme est cependant moins étudiée. Durant cette étape, la qualité du PO peut être dégradée par des perturbations aléatoires (ex : arrivée d’urgences). Notre question de recherche est la suivante : « Comment gérer les perturbations aléatoires durant le déroulement du programme opératoire afin de maintenir le niveau de performance visé ? ». Pour y répondre, nous proposons de construire un jumeau numérique asynchrone du bloc opératoire et de l’utiliser comme outil d’aide à la décision pour la régulation. Cet outil permettra d’étudier a posteriori les dysfonctionnements d’une journée opératoire, de tester l’impact de modifications du PO en cours d’exécution sur la performance du BO, et d’étudier la robustesse d’un PO prévisionnel. Nous proposons une démarche générique pour construire un modèle de simulation permettant de simuler l’exécution d’un programme opératoire prévisionnel ou réalisé dans un environnement déterministe ou stochastique. Nous avons appliqué cette démarche dans le bloc opératoire de l’Hôpital Privé de La Baie (Avranches, Normandie) du groupe Vivalto Santé
Simulation de l'entraide entre deux SAMU pour la prise en charge des appels d'urgence
No full textNational audienceL'accès sans délai à un SAMU constitue un enjeu central pour les patients et particulièrement ceux dans les situations les plus graves. Répondre à cet objectif stratégique appelle non seulement à mettre en adéquation la planification des professionnels avec la charge d'appels et aussi à optimiser les organisations. Confrontés à une augmentation du nombre d'appels qui leur sont destinés, les SAMU cherchent à faire évoluer leurs organisations internes. L'objectif de cet article est d'évaluer, à l'aide de la simulation, l'impact d'une nouvelle organisation sous la forme d'une virtualisation de la distribution des appels permettant une entraide entre différents SAMU de la région Pays de la Loire. Cet article présente les premiers résultats obtenus avec deux SAMU dans le cadre du projet CallSAMU financé par la DGOS et porté par le CHU de Nantes
Une estimation exacte du forçage radiatif par la méthode de Monte-Carlo
No full textNational audienceNous souhaitons estimer le flux radiatif quittant la Terre intégré sur l'infrarouge thermique, sur toute la surface du globe et sur une période climatique de longue durée. Ce calcul est réputé très difficile à réaliser si on ne fait pas de simplifications de la description fréquentielle, spatiale ou temporelle (e.g. passer d'un modèle raie-par-raie à un modèle de bande, utiliser une discrétisation temporelle plus grossière, etc). Nous montrons que la méthode de Monte Carlo permet d'éviter ces simplifications si on associe les deux idées suivantes : introduire des collisionneurs fictifs pour permettre le suivi de rayon sans connaissance du champ de coefficient d'extinction et échantillonner statistiquement les raies spectrales. Nous montrons qu'il n'est pas plus coûteux de réaliser cette intégration sur un jour ou un mois, sur une colonne atmosphérique ou sur toute la Terre, ou finalement sur une bande étroite fréquentielle ou sur tout le spectre infrarouge
Synthesis and Characterization of Hydroxyapatite and Hydroxyapatite-Based Catalysts
No full textInternational audienceA solid catalyst should exhibit high activity, high selectivity, and good stability. Hydroxyapatite (HA), which is a calcium phosphate with a Ca/P molar ratio of 1.67, and the derived materials constitute a new promising family of catalytic materials. In fact, HA can be used as a catalyst or catalyst support in several applications, which can be attributed to its specific structure and properties such as the modular molar ratio of Ca/P, the high thermal stability, and the exceptional capacity of ion exchange. The chemical composition, the morphology, and the textural and physicochemical properties of HA and HA-based catalysts strongly depend on the preparation methods that include coprecipitation, sol–gel, emulsion, hydrolysis, mechanosynthesis, etc. This chapter aims to provide a comprehensive summary on the synthesis methods of HA and HA-based catalysts for various chemical applications. The basic characteristics of these materials are also presented. The discussion begins with an introduction, followed by an overview of HA synthesis methods and its properties. Finally, prospects on challenges and opportunities for the development of HA-based catalysts are highlighted
Impact of Industrial Cyber-Physical Systems on the Health System
No full textInternational audienceAs in the industrial field, though arguably far less mature, health cyber-physical systems (HCPS) are a key element in the evolution and modernization of the health system. This chapter provides an overview of the main applications of CPS in the health domain, and more specifically in the production of healthcare. Recently, a digital transformation of the healthcare production system has made it possible to encourage and promote the evolution of medical devices, medical practices and engineering in the organization of flows. HCPS combine the use of smart biosensors and various connected objects, with access to data from patient health records, to facilitate decision support, whether medical or organizational. The concept of a digital twin can be considered as one of the key elements of a cyber-physical system, provided that one of its basic principles is respected, namely a real-time interaction between the virtual and the physical world