4 research outputs found
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
Multiferroic oxide-based thin films applied to magnetic refrigeration
LâĂ©nergie est indispensable pour lâhomme dans la vie quotidienne et essentielle Ă la croissance Ă©conomique et au progrĂšs du dĂ©veloppement dans les secteurs industriels. Les sources dâĂ©nergie mondiales proviennent principalement de ressources fossiles (pĂ©trole, charbons, gaz) qui sont la principale source de pollution atmosphĂ©rique locale et lâĂ©metteur des gaz Ă effet de serre comme le dioxyde de carbone (CO2), responsable en grande partie de lâappauvrissement de la couche dâozone. Dans le contexte de la pĂ©nurie actuelle de ces ressources en raison de lâaugmentation continue de la demande dâĂ©nergie et alors que les rĂ©serves fossiles finiront par sâĂ©puiser, la dĂ©couverte et le dĂ©veloppement dâune technologie Ă faible Ă©mission de carbone deviennent critiques avec la nĂ©cessitĂ© de dĂ©carboniser et rĂ©duire notre dĂ©pendance aux combustibles fossiles. Une de ces technologies est la rĂ©frigĂ©ration magnĂ©tique basĂ©e sur lâeffet magnĂ©tocalorique (MCE). Au cours de cette thĂšse, nous avons Ă©tudiĂ© les propriĂ©tĂ©s magnĂ©tiques et magnĂ©tocaloriques des films minces dâoxydes fortement corrĂ©lĂ©s Ă structure pĂ©rovskite dĂ©posĂ©s par ablation laser pour les applications de la rĂ©frigĂ©ration magnĂ©tique. Les rĂ©sultats obtenus montrent que les propriĂ©tĂ©s magnĂ©tiques et magnĂ©tocaloriques de composĂ©s PrVO3 peuvent ĂȘtre facilement modulĂ©es en utilisant lâapproche des couches minces. En particulier, le champ magnĂ©tique coercitif a considĂ©rablement diminuĂ© faisant Ă partir du composĂ© PVO un aimant presque doux dans la rĂ©gion oĂč lâentropie magnĂ©tique est libĂ©rĂ©e ainsi quâune augmentation considĂ©rable de lâaimantation de saturation. En consĂ©quence, un effet magnĂ©tocalorique gĂ©ant est prĂ©sentĂ©e par les films minces de PVO dĂ©posĂ©s sur un substrat de LSAT Ă basse tempĂ©rature montrant lâimpact de lâeffet des contraintes Ă©pitaxiales. Dâautre part, les calculs DFT ont confirmĂ© lâĂ©tat fondamental et la compĂ©tition entre les interactions magnĂ©tiques sous contraintes de compression dans PVO films minces. Notre rĂ©sultat suggĂšre non seulement que les couches minces Ă©pitaxiales de PVO sont potentielles pour la rĂ©frigĂ©ration aux tempĂ©ratures cryogĂ©niques mais peuvent Ă©galement ouvrir la voie Ă crĂ©er de nombreuses nouvelles fonctionnalitĂ©s dans les oxydes perovskite par le contrĂŽle des aspects structurels. Les mĂ©canismes menant Ă lâeffet magnĂ©tocalorique anisotropique gĂ©ant observĂ© dans les monocristaux du HoMn2O5 sont Ă©galement Ă©tudiĂ©s. Les calculs DFT et la simulation de Monte Carlo nous ont permis dâexplorer le rĂŽle des ions dâHolmium en tant que principal contributeur au MCE ainsi que lâimportance des propriĂ©tĂ©s anisotropes intrinsĂšques comme moyen prometteur dâoptimiser lâEMC pour lâapplication de la rĂ©frigĂ©ration magnĂ©tique Ă basse tempĂ©rature ainsi que la mise en Ćuvre de rĂ©frigĂ©rateurs magnĂ©tiques rotatifs compacts et efficaces.Energy is essential for humans in everyday life and critical to economic growth and developement progress in industrial sectors. The global energy sources are mostly from fossil resources (e.g oil, coals, gas) being dominant source of local air pollution and emitter of the most dangerous green house gases such as carbon dioxide (CO2), largely responsible for the ozone layer depletion. In the context of the current shortage of those ressources due to the continuously increase in demands in energy and while fossil reserves will eventually run out, the discovery and development of a low-carbon technologies become critical with the need to decarbonise and reduce our dependency to fossil fuels. One of theses technologies is the magnetic refrigeration based on the magnetocaloric effect (MCE). In this thesis, we have investigated the magnetic and magnetocaloric properties of strongly correlated oxides thin films grown by pulsed laser deposition in view of their portential application in magnetic cooling. The obtained results reveal that the magnetic and magnetocaloric properties of PrVO3 (PVO) compounds can be easy tailored by using the thin films approach. Particularly, the coercive magnetic field was dramatically decreased making from the PVO compound a nearly soft magnet in the region where the magnetic entropy change is released as well as a considerable increase in saturation magnetization. Accordingly, a giant magnetocaloric effect is exhibited by PVO thin films grown on LSAT substrate at low temperatures showing the great impact of strain effects. This finding opens the way for the implementations of PVO thin films in some specific applications such as on-chip magnetic cooling of a nanoelectronic device and sensor technology. On the other hand, the DFT calculations have confirmed the ground state and the competition between magnetic interactions under compressive strains in PVO thin films. Our result not only suggests that epitaxial PVO thin films is potential for refrigeration at cryogenic temperatures but may also pave the way to create many novel functionalities in perovskite-type transition metal oxides by control of structural aspects.The mechanisms leading to the giant anisotropic magnetocaloric effect observed in HoMn2O5 single crystals are also studied. Both DFT calculations and Monte Carlo simulation allowed us to explore the role of Holmium ions as the main contributor to the MCE as well as the of the importance of the intrinsic anisotropic properties as a promising way to optimize the MCE for magnetic refrigeration application at low temperature regime as well as the implementation of compact and efficient rotary magnetic refrigerators
Couches minces Ă base dâoxyde multiferroĂŻque appliquĂ©es Ă la rĂ©frigĂ©ration magnĂ©tique
Energy is essential for humans in everyday life and critical to economic growth and developement progress in industrial sectors. The global energy sources are mostly from fossil resources (e.g oil, coals, gas) being dominant source of local air pollution and emitter of the most dangerous green house gases such as carbon dioxide (CO2), largely responsible for the ozone layer depletion. In the context of the current shortage of those ressources due to the continuously increase in demands in energy and while fossil reserves will eventually run out, the discovery and development of a low-carbon technologies become critical with the need to decarbonise and reduce our dependency to fossil fuels. One of theses technologies is the magnetic refrigeration based on the magnetocaloric effect (MCE). In this thesis, we have investigated the magnetic and magnetocaloric properties of strongly correlated oxides thin films grown by pulsed laser deposition in view of their portential application in magnetic cooling. The obtained results reveal that the magnetic and magnetocaloric properties of PrVO3 (PVO) compounds can be easy tailored by using the thin films approach. Particularly, the coercive magnetic field was dramatically decreased making from the PVO compound a nearly soft magnet in the region where the magnetic entropy change is released as well as a considerable increase in saturation magnetization. Accordingly, a giant magnetocaloric effect is exhibited by PVO thin films grown on LSAT substrate at low temperatures showing the great impact of strain effects. This finding opens the way for the implementations of PVO thin films in some specific applications such as on-chip magnetic cooling of a nanoelectronic device and sensor technology. On the other hand, the DFT calculations have confirmed the ground state and the competition between magnetic interactions under compressive strains in PVO thin films. Our result not only suggests that epitaxial PVO thin films is potential for refrigeration at cryogenic temperatures but may also pave the way to create many novel functionalities in perovskite-type transition metal oxides by control of structural aspects.The mechanisms leading to the giant anisotropic magnetocaloric effect observed in HoMn2O5 single crystals are also studied. Both DFT calculations and Monte Carlo simulation allowed us to explore the role of Holmium ions as the main contributor to the MCE as well as the of the importance of the intrinsic anisotropic properties as a promising way to optimize the MCE for magnetic refrigeration application at low temperature regime as well as the implementation of compact and efficient rotary magnetic refrigerators.LâĂ©nergie est indispensable pour lâhomme dans la vie quotidienne et essentielle Ă la croissance Ă©conomique et au progrĂšs du dĂ©veloppement dans les secteurs industriels. Les sources dâĂ©nergie mondiales proviennent principalement de ressources fossiles (pĂ©trole, charbons, gaz) qui sont la principale source de pollution atmosphĂ©rique locale et lâĂ©metteur des gaz Ă effet de serre comme le dioxyde de carbone (CO2), responsable en grande partie de lâappauvrissement de la couche dâozone. Dans le contexte de la pĂ©nurie actuelle de ces ressources en raison de lâaugmentation continue de la demande dâĂ©nergie et alors que les rĂ©serves fossiles finiront par sâĂ©puiser, la dĂ©couverte et le dĂ©veloppement dâune technologie Ă faible Ă©mission de carbone deviennent critiques avec la nĂ©cessitĂ© de dĂ©carboniser et rĂ©duire notre dĂ©pendance aux combustibles fossiles. Une de ces technologies est la rĂ©frigĂ©ration magnĂ©tique basĂ©e sur lâeffet magnĂ©tocalorique (MCE). Au cours de cette thĂšse, nous avons Ă©tudiĂ© les propriĂ©tĂ©s magnĂ©tiques et magnĂ©tocaloriques des films minces dâoxydes fortement corrĂ©lĂ©s Ă structure pĂ©rovskite dĂ©posĂ©s par ablation laser pour les applications de la rĂ©frigĂ©ration magnĂ©tique. Les rĂ©sultats obtenus montrent que les propriĂ©tĂ©s magnĂ©tiques et magnĂ©tocaloriques de composĂ©s PrVO3 peuvent ĂȘtre facilement modulĂ©es en utilisant lâapproche des couches minces. En particulier, le champ magnĂ©tique coercitif a considĂ©rablement diminuĂ© faisant Ă partir du composĂ© PVO un aimant presque doux dans la rĂ©gion oĂč lâentropie magnĂ©tique est libĂ©rĂ©e ainsi quâune augmentation considĂ©rable de lâaimantation de saturation. En consĂ©quence, un effet magnĂ©tocalorique gĂ©ant est prĂ©sentĂ©e par les films minces de PVO dĂ©posĂ©s sur un substrat de LSAT Ă basse tempĂ©rature montrant lâimpact de lâeffet des contraintes Ă©pitaxiales. Dâautre part, les calculs DFT ont confirmĂ© lâĂ©tat fondamental et la compĂ©tition entre les interactions magnĂ©tiques sous contraintes de compression dans PVO films minces. Notre rĂ©sultat suggĂšre non seulement que les couches minces Ă©pitaxiales de PVO sont potentielles pour la rĂ©frigĂ©ration aux tempĂ©ratures cryogĂ©niques mais peuvent Ă©galement ouvrir la voie Ă crĂ©er de nombreuses nouvelles fonctionnalitĂ©s dans les oxydes perovskite par le contrĂŽle des aspects structurels. Les mĂ©canismes menant Ă lâeffet magnĂ©tocalorique anisotropique gĂ©ant observĂ© dans les monocristaux du HoMn2O5 sont Ă©galement Ă©tudiĂ©s. Les calculs DFT et la simulation de Monte Carlo nous ont permis dâexplorer le rĂŽle des ions dâHolmium en tant que principal contributeur au MCE ainsi que lâimportance des propriĂ©tĂ©s anisotropes intrinsĂšques comme moyen prometteur dâoptimiser lâEMC pour lâapplication de la rĂ©frigĂ©ration magnĂ©tique Ă basse tempĂ©rature ainsi que la mise en Ćuvre de rĂ©frigĂ©rateurs magnĂ©tiques rotatifs compacts et efficaces