Challenges Facing Distance Education for Children in Virtual Kindergartens

For kindergarten children, distance education was neither an alternative nor a potential option to in-person schooling before the global COVID-19 pandemic-imposed isolation and mandatory social distancing measures. These measures guaranteed the safety of school staff and children and made the adoption of distance education an urgent necessity for children to continue their education safely. The current study was conducted to reveal the most common challenges that faced children’s distance education in virtual kindergartens. The study was conducted from the teachers’ point of view to determine the impact of each of the job title variables and years of experience. The study sample consisted of 32 kindergarten teachers in Jubail Governorate. The research team applied the scale of challenges facing children’s education in virtual kindergarten. The results of the study concluded that the most important challenges facing children’s education in virtual kindergartens were related to communication skills (79.9%), technical skills (79.5%), educational aids (76.4%), and motivation (69.6%). The results of the study also revealed that there were statistically significant differences in the challenges related to motivation and readiness and in the total challenges facing children’s education in the virtual kindergarten from the teachers’ point of view depending on the job title—that is, the assistant teacher where the calculated “U” value reached 28.5 and 37.5. In addition, there was an absence of statistically significant differences due to the variable years of experience, whether in the total number of challenges or in the dimensions of the scale, except for the dimension of communication skills, where the calculated “Ka2” value reached 8.755, which is a statistically significant value at the level of significance (0.05)

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 low–middle-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 ‘single-use’ 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 low–middle-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 high– and low–middle–income countries

Robust nonlinear adaptive control of multiphase synchronous buck power converters

International audienceThe problemofcontrollingmultiphasesynchronousbuckpowerconvertersisconsidered.Theaimsare to regulatetheoutputvoltageoftheconverterandtoensureadequatecurrentsharingbetweenits different channels.Usingthebacksteppingtechnique,anadaptivecontrollerisdesignedbasedona large-signal bilinearmodelofthewholemulti-channelconverter.Aparameterprojectionisusedto ensurethattheobtainedadaptivecontrollerisrobusttoparasiticresistances.Thecontrollerisformally shown tomeettheobjectivesofclosed-loopasymptoticstability,outputreferencetracking,andequal load sharing.Theattractionregiondependsontheuncertainparasiticimpedancesize,withthe attraction regionbeinglargerforsmallerparasiticimpedances.Intheidealcaseofnoparasitic impedances,theclosed-loopasymptoticstabilityisglobal.Thesetheoreticalresultsareconfirmedby simulation

Nonlinear adaptive control for MPPT in photovoltaic systems

International audienceWe are considering the problem of maximum power point tracking (MPPT) in photovoltaic (PV) arrays. The PV power transferred to the battery through a controlled a PWM Boost power converter. As the maximum power point (MPP) of PV generators varies with solar radiation and temperature, an adaptive controller is proposed. The latter is designed using a backstepping technique, based on a nonlinear model describing the dynamics of the boost converter, the PV arrays and the battery. It is formally shown under mild assumptions that the developed adaptive controller actually meets the maximum power point tracking requirement