Search

Il presente contributo descrive in modo sintetico il progetto e i risultati conseguiti riferiti allo sviluppo di un’innovativa piattaforma a raggi X per il controllo bagagli e colli in generale, realizzato da Gilardoni Spa, azienda italiana dedita alle attività di ricerca e sviluppo connesse alla progettazione, costruzione validazione e commercializzazione di sistemi di controllo basati sull’utilizzo dei raggi X. Il progetto è stato co-finanziato dal bando Tech Fast, di Regione Lombardia a valere sul POR FESR 2014 –2020, ed eseguito tra il 2021 e il 2022, portando alla realizzazione di un prototipo pienamente funzionante.

International audience; There is a large design variety of power buses, with voltage levels typically ranging from 28 to 100V. This state-of-art is well adapted to past and current needs in term of power conditioning and disctribution for science and telecommunication satellites. NEvertheless, a short-term need is rising for higher operating voltages, especially for the new electric propulsion systems and high-power payloads. The currently available solutions are to add DC/DC converters inisde echa user equipement to generate all its necessary internal supply lines for the satellite primary power bus. For high power/high voltage loads, this DC/DC stage leads to power dissipation and lowers the overall efficiency of the power chain. A major step forward would be to increase the voltage directly at the level of the primary bus in order to remove some voltage conversion stages leading to lower mass, cost, volume and power dissipation. The work performed within the European Union H2020 project "HV-EPSA" was aimed to study benefits and impact of the implementation of a bus voltage from 300V to 600V, including solar array, solar array drive mechnism, power conditioning and distribution, Hall effect thruster with direct drive topology, battery and harnesses. The main problematic to solve were arcing at high voltage/low pressure (Paschen law), interaction between plasma (natural and from plasmic propulsion) and solar arrays, and distribution function using GaN mosfet. Several test campaigns were performed and the results are presented in the paper.; Il existe une grande variété de conception de bus d'alimentation, avec des niveaux de tension allant généralement de 28 à 100 V. Cet état de l'art est bien adapté aux besoins passés et actuels en termes de conditionnement et de distribution de puissance pour les satellites scientifiques et de télécommunications. Néanmoins, le besoin à court terme augmente pour des tensions de fonctionnement plus élevées, en particulier pour les nouveaux systèmes de propulsion électrique et les charges utiles à haute puissance. Les solutions actuellement disponibles consistent à ajouter des convertisseurs DC / DC à l'intérieur de chaque équipement utilisateur afin de générer toutes ses lignes d'alimentation interne nécessaires pour le bus d'alimentation primaire du satellite. Pour les charges haute puissance / haute tension, cet étage DC / DC conduit à une dissipation de puissance et diminue l'efficacité globale de la chaîne de puissance. Un grand pas en avant serait d'augmenter la tension directement au niveau du bus primaire afin de supprimer certains étages de conversion de tension conduisant à une diminution de la masse, du coût, du volume et de la dissipation de puissance. Les travaux réalisés dans le cadre du projet H2020 de l'Union européenne "HV-EPSA" visaient à étudier les avantages et l'impact de la mise en œuvre d'une tension de bus de 300V à 600V, y compris les panneaux solaires, les systèmes d'entraînement de panneaux solaires, le conditionnement et la distribution de l'énergie, le propulseur à effet Hall avec topologie à entraînement direct, batterie et cablâge. Les principaux problèmes à résoudre étaient les arcs à haute tension / basse pression (loi de Paschen), l'interaction entre le plasma (naturel et de propulsion plasmique) et les panneaux solaires, et la fonction de distribution à l'aide du mosfet GaN. Plusieurs campagnes de tests ont été réalisées et les résultats sont présentés dans l'article.

The best timing of orotracheal intubation and invasive ventilation in COVID-19 patients with acute respiratory distress syndrome is unknown. The use of non-invasive ventilation, a life-saving technique in many medical conditions, is debated in patients with ARDS since prolonged NIV and delayed intubation may be harmful. Shortage of intensive care beds and ventilators during a respiratory pandemic can trigger a widespread use of early non-invasive ventilation in many hospitals but which is the best way to ventilate patients with severe bilateral pneumonia and severely increased spontaneous ventilation is controversial. Moreover, viral spreading to health-care workers and other hospitalized patients is an issue for any device used to administer oxygen. Even if protective mechanical ventilation is currently the gold standard for the management of acute respiratory distress syndrome, tracheal intubation is not without risks and is associated with delirium, hemodynamic instability, immobilization and post intensive care syndrome. Both invasive and non-invasive ventilation are associated with advantages and limitations that should be carefully considered when patients with COVID-19-ARDS need our attention. In the absence of strong evidence , in this review we highlight all the pro and con of these two different approaches.