NASA’s all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61$^{+0.09} _{-0.10}$ R$_\oplus$), TOI-771b (1.42$^{+0.11} _{-0.09}$ R$_\oplus$), TOI-871b (1.66$^{+0.11} _{-0.11}$ R$_\oplus$), TOI-1467b (1.83$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-1739b (1.69$^{+0.10} _{-0.08}$ R$_\oplus$), TOI-2068b (1.82$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-4559b (1.42$^{+0.13} _{-0.11}$ R$_\oplus$), and TOI-5799b (1.62$^{+0.19} _{-0.13}$ R$_\oplus$). Among all these planets, six of them fall within the region known as ‘keystone planets’, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.

The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.

Most engineering structural metallic alloys are used in polycrystalline form. The nature of the mechanical response of these systems is complex and hierarchical, spanning a range of scales. Lattice strains, distortions and defects (notably, dislocations) nucleate, interact, pile up at grain boundaries and self-organize at the (sub)micrometre scale. Individual grains experience strong interactions with their neighbours and geometric features (cracks, notches). Groups of grains sharing common orientation find themselves embedded within large ensembles possessing certain statistical properties (size distributions, preferred orientation, etc.). Ultimately, the macroscopic properties of grain aggregates are determined by this hierarchy of interactions. Notably, while collective properties such as stiffness are relatively well represented by averages, strength properties associated with fracture, fatigue crack propagation, creep and damage show a strong dependence on the local microscopic conditions of the ‘weakest link’. Ongoing improvements in the spatial resolution of X-ray imaging and tomography and the availability of micro-focused X-ray beams open up a number of opportunities for the study of the structure and deformation at (sub)micrometre scales. Fundamental questions concerning the scale dependence and strain gradient effects in solids can now be tackled by the combination of synchrotron X-ray methods and suitably refined deformation modelling. In this study, a range of methodologies and experimental configurations are presented that have allowed us to develop improved insight into the physical mechanisms of plastic deformation in ductile metallic alloys. Examples include white-beam energy-dispersive diffraction, micro-beam Laue diffraction, scanning micro-beam diffraction topography, high-resolution reciprocal space mapping and imaging. Connections are established with advanced numerical models of polycrystal deformation using strain gradient plasticity and discrete dislocation dynamics modelling.