An adaptive finite element procedure for fully-coupled point contact elastohydrodynamic lubrication problems

This paper presents an automatic locally adaptive finite element solver for the fully-coupled EHL point contact problems. The proposed algorithm uses a posteriori error estimation in the stress in order to control adaptivity in both the elasticity and lubrication domains. The implementation is based on the fact that the solution of the linear elasticity equation exhibits large variations close to the fluid domain on which the Reynolds equation is solved. Thus the local refinement in such region not only improves the accuracy of the elastic deformation solution significantly but also yield an improved accuracy in the pressure profile due to increase in the spatial resolution of fluid domain. Thus, the improved traction boundary conditions lead to even better approximation of the elastic deformation. Hence, a simple and an effective way to develop an adaptive procedure for the fully-coupled EHL problem is to apply the local refinement to the linear elasticity mesh. The proposed algorithm also seeks to improve the quality of refined meshes to ensure the best overall accuracy. It is shown that the adaptive procedure effectively refines the elements in the region(s) showing the largest local error in their solution, and reduces the overall error with optimal computational cost for a variety of EHL cases. Specifically, the computational cost of proposed adaptive algorithm is shown to be linear with respect to problem size as the number of refinement levels grows

English headteacher perspectives on school responses to protect student and staff mental wellbeing in the later stages of the COVID-19 pandemic

Objective: The COVID-19 pandemic has had a significant impact on pupils and staff in English schools. This study aimed to provide an in-depth understanding of the challenges schools faced and the processes they implemented to protect the mental wellbeing of students and staff in the later stages of the pandemic, focusing on January–June 2022. Design: Qualitative study. Setting: Primary and secondary schools in England from April to September 2022. Method: Ten semi-structured interviews were conducted using Zoom with six primary and four secondary school headteachers (or other members of the senior leadership team) in England. Results: Mental wellbeing programming for students and staff was scaled up in both primary and secondary schools amid concerns that the COVID-19 pandemic would impact on mental health. Headteachers perceived changes in the behaviour of students, including increased dysregulation, and staff struggling with fatigue and a sense of being devalued as professionals. Schools scaled up the supports they offered to students and staff, but challenges remain in maintaining such increased support due to the perceived additional needs of staff and students within the context of funding constraints. Despite initial concerns that there would be tension between promoting mental wellbeing and academic catch-up among students, headteachers identified work addressing these two priorities as synergistic. Conclusion: Mental wellbeing impacts of the pandemic on pupils and staff required increased provision of support programmes. Ongoing efforts to monitor the wellbeing needs of students and staff is required. Formal and informal methods to enhance the mental health for pupils and staff should continue into the recovery period

Two mini-Neptunes Transiting the Adolescent K-star HIP 113103 Confirmed with TESS and CHEOPS

We report the discovery of two mini-Neptunes in near 2:1 resonance orbits ($P=7.610303$ d for HIP 113103 b and $P=14.245651$ d for HIP 113103 c) around the adolescent K-star HIP 113103 (TIC 121490076). The planet system was first identified from the TESS mission, and was confirmed via additional photometric and spectroscopic observations, including a $\sim$17.5 hour observation for the transits of both planets using ESA CHEOPS. We place $\leq4.5$ min and $\leq2.5$ min limits on the absence of transit timing variations over the three year photometric baseline, allowing further constraints on the orbital eccentricities of the system beyond that available from the photometric transit duration alone. With a planetary radius of $R_{p}=1.829^{+0.096}_{-0.067}\,R_{\oplus}$, HIP 113103 b resides within the radius gap, and this might provide invaluable information on the formation disparities between super-Earths and mini-Neptunes. Given the larger radius $R_{p}=2.40^{+0.10}_{-0.08}\,R_{\oplus}$ for HIP 113103 c, and close proximity of both planets to HIP 113103, it is likely that HIP 113103 b might have lost (or is still losing) its primordial atmosphere. We therefore present simulated atmospheric transmission spectra of both planets using JWST, HST, and Twinkle. It demonstrates a potential metallicity difference (due to differences in their evolution) would be a challenge to detect if the atmospheres are in chemical equilibrium. As one of the brightest multi sub-Neptune planet systems suitable for atmosphere follow up, HIP 113103 b and HIP 113103 c could provide insight on planetary evolution for the sub-Neptune K-star population.Comment: 18 pages, 12 figures, accepted for publication in the Monthly Notices of the Royal Astronomical Societ

A mini-Neptune from TESS and CHEOPS around the 120 Myr Old AB Dor Member HIP 94235

The Transiting Exoplanet Survey Satellite (TESS) mission has enabled discoveries of the brightest transiting planet systems around young stars. These systems are the benchmarks for testing theories of planetary evolution. We report the discovery of a mini-Neptune transiting a bright star in the AB Doradus moving group. HIP 94235 (TOI-4399, TIC 464646604) is a Vmag = 8.31 G-dwarf hosting a ${3.00}_{-0.28}^{+0.32}\,{R}_{\oplus }$ mini-Neptune in a 7.7 day period orbit. HIP 94235 is part of the AB Doradus moving group, one of the youngest and closest associations. Due to its youth, the host star exhibits significant photometric spot modulation, lithium absorption, and X-ray emission. Three 0.06% transits were observed during Sector 27 of the TESS Extended Mission, though these transit signals are dwarfed by the 2% peak-to-peak photometric variability exhibited by the host star. Follow-up observations with the Characterising Exoplanet Satellite confirmed the transit signal and prevented the erosion of the transit ephemeris. HIP 94235 is part of a 50 au G-M binary system. We make use of diffraction limited observations spanning 11 yr, and astrometric accelerations from Hipparcos and Gaia, to constrain the orbit of HIP 94235 B. HIP 94235 is one of the tightest stellar binaries to host an inner planet. As part of a growing sample of bright, young planet systems, HIP 94235 b is ideal for follow-up transit observations, such as those that investigate the evaporative processes driven by high-energy radiation that may sculpt the valleys and deserts in the Neptune population