We analyse the small-scale characteristics, such as enstrophy, total strain and normality/non-normality, in the three-dimensional, separated flow around a NACA 0018 wing using direct numerical simulations. The angle of attack is $10^\circ$ and the Reynolds number (based on the chord length) is $Re_c=5000$. The role of non-normality is investigated by performing Schur decomposition of the velocity gradient tensor. We also apply the Schur decomposition to derive new expressions for the production of enstrophy and total strain arising from the mean flow inhomogeneity. We focus on two sections of the flow, across the recirculating zone and along the transitioning shear layer, and compare our results with homogeneous isotropic turbulence (HIT). Within the recirculating region, the non-normality index is approximately 0 (and close to the HIT value), indicating almost equal normal and non-normal contributions. However, in the separating layer non-normal effects strongly dominate, especially in the region of kinetic energy growth. Only in the decay region do the values of the non-normality index gradually approximate HIT values. The production of enstrophy due to vortex stretching is dominated by the mixed (interaction) term, where normal strain stretches non-normal vorticity. The same component also dominates the strain self-amplification term. The contributions of different QR regions to the production terms are also examined. Production due to mean strain rate is triggered upstream compared with production due to fluctuating strain fields.

The need to urgently shift away from fossil-based systems of energy for the sake of the planet and its people is clear. The green transition comes, however, with negative impacts on human rights and the environment, notably on the rights of Indigenous Peoples in the Global South, where most of the essential minerals and metals needed for the transition are found. In this piece, we discuss recent legal developments in the Netherlands from the perspective of the need for a just energy transition. Against the background of the recently adopted European Union (EU) Corporate Sustainability Due Diligence Directive (CSDDD), we analyze two draft Dutch due diligence laws and their potential in the context of a just energy transition. The focus is on the rights of Indigenous Peoples who are in an extremely vulnerable position in the transition process.

The United Kingdom was the first country to legalize the refusal to provide health care in the name of “conscientious objection”, allowing doctors to refuse to provide abortions based on personal or religious beliefs.

A historical review into the origins and motivation behind the “conscientious objection” clause in the 1967 Abortion Act found that Parliamentarians and the medical profession wanted to preserve doctors’ authority over patients, protect objecting doctors from liability, and appease religious anti-abortion beliefs.

These factors point to an unprincipled basis for the introduction of “conscientious objection” into healthcare, which ultimately came at the expense of patients’ rights and health. The “conscience clause” also represented a negation of basic ethical directives in medical practice including patient autonomy and physicians’ fiduciary duty to patients. The term “conscientious objection”— borrowed from the military but misapplied to healthcare — helped mask the practice as a moral “right” of doctors, even while it disregarded patients’ health and dignity.

Refusing to provide treatment on the basis of “conscience” is harmful and discriminatory, and should be phased out gradually using disincentives and other measures to encourage objectors to choose other fields.

The settling velocity of frozen hydrometeors in the atmospheric surface layer depends on their inertial and drag properties, and on the intensity of ambient turbulence. Thin, solid and perforated circular disks have been investigated through high-speed imaging, under laboratory conditions, to reproduce the settling of snow plates and dendrites in quiescent and turbulent flows. Different perforations made it possible to test the parameterisation of the fall speed in quiescent air, based on the geometric description of the solidity of the disk cross-sectional area. Interestingly, different falling styles, ranging from stable horizontal to fluttering and tumbling, were observed to depend significantly on the perforation geometry, which resulted in the stabilisation of the particle rotation and in a modulation of the drag coefficient. Ambient turbulence is observed to primarily induce cross-flow drag on the disks settling in the nonlinear regime, causing a reduction of the settling velocity in all cases investigated. Turbulence also manifests a secondary effect on the disk rotational dynamics, in particular when tumbling and stable falling styles co-exist, based on the phase space defined by the Reynolds number $Re$ and the inertia ratio $I^*$. The interaction between ambient turbulence, particle anisotropy and permeability and the likelihood of tumbling is inferred to be the main reason for the observed settling velocity variability of snow dendrites in nature.

Norway is, in many aspects, at the forefront of the global energy transition. Nevertheless, a human rights paradox in Norway’s energy transition plan is that while addressing climate-related human rights impacts, it might come at a high cost to the rights of the Indigenous Sámi People. Mining operations and renewable energy developments in the Sámi ancestral lands have already threatened reindeer husbandry, on which certain Sámi communities rely for a living, and which represents an integral component of their cultural identity. Resolving this paradox is crucial to achieving a just transition that leaves no one behind. Against this backdrop, the piece examines how the Norwegian Transparency Act—a mandatory human rights due diligence initiative—can address the impacts on Sámi rights caused by companies involved in renewable energy and extractive developments on Sámi lands.

Achieving precise control over the dynamic manipulation of a drop using an external magnetic field may face challenges due to the intricate relationship between the induced magnetisation and the inherent magnetic properties of the drop. Here, we put forward a fundamental theory that elucidates the morphology and behaviour of a ferrofluid droplet immersed in a different, viscous fluid when subjected to a uniform external magnetic field. Unlike previous studies, we introduce an asymptotic model that investigates the dynamic evolution of the drop by examining the local magnetisation as a function of the magnetic field itself. This leads to an additional contribution to the interfacial energy, resulting in an excess normal traction at the interface. Our analytical findings highlight the significant impact of saturation magnetisation and initial susceptibility of the ferrofluid on the resulting dynamic characteristics, which are further explored through comprehensive numerical simulations to address deformations beyond the scope of the asymptotic theory. Supported by benchmark numerical and experimental results, our study suggests that higher magnetic fields and/or greater saturation magnetisation can enhance drop elongation and accelerate its settling process. We develop a regime map illustrating various dynamic events based on the magnetic properties, which could have fundamental implications for the design and control of micro-encapsulations across a wide range of applications, including thermal processing, chemical synthesis, analysis and medical diagnostics.

The hitherto oldest known mass mortality of clam shrimp is described from the Early Devonian (Emsian) of Luxembourg. This (almost) monospecific clam shrimp association allows for a much more comprehensive assessment and understanding of preservational and ontogenetic variation in a single taxon, Pseudestheria diensti (Gross, 1934). This suggests that other taxa originally described from the “classical” Willwerath locality, the type locality of P. diensti, are variants of the latter, and thus Pseudestheria subcircularis Raymond, 1946 and Palaeolimnadiopsis ? eifelensis Raymond, 1946 are synonymized here with P. diensti. A further clam shrimp taxon, for which we propose a new species, Palaeolimnadia stevenbeckeri n. sp., is found in the same stratum, but not in the mass mortality layer itself. The clam shrimp mass mortality is interpreted to reflect sudden destruction of the original habitat on a delta plain and subsequent transport and burial in a marginal marine low-energy setting.

http://zoobank.org/0cfcb6a1-3fb7-4a1a-a1a4-609f8b1bc536

We consider a new approach in the definition of two-dimensional heavy-tailed distributions. Specifically, we introduce the classes of two-dimensional long-tailed, of two-dimensional dominatedly varying, and of two-dimensional consistently varying distributions. Next, we define the closure property with respect to two-dimensional convolution and to joint max-sum equivalence in order to study whether they are satisfied by these classes. Further, we examine the joint-tail behavior of two random sums, under generalized tail asymptotic independence. Afterward, we study the closure property under scalar product and two-dimensional product convolution, and by these results, we extended our main result in the case of jointly randomly weighted sums. Our results contained some applications where we establish the asymptotic expression of the ruin probability in a two-dimensional discrete-time risk model.

We employ a novel computational modelling framework to perform high-fidelity direct numerical simulations of aero-structural interactions in bat-inspired membrane wings. The wing of a bat consists of an elastic membrane supported by a highly articulated skeleton, enabling localised control over wing movement and deformation during flight. By modelling these complex deformations, along with realistic wing movements and interactions with the surrounding airflow, we expect to gain new insights into the performance of these unique wings. Our model achieves a high degree of realism by incorporating experimental measurements of the skeleton’s joint movements to guide the fluid–structure interaction simulations. The simulations reveal that different segments of the wing undergo distinct aeroelastic deformations, impacting the flow dynamics and aerodynamic loads. Specifically, the simulations show significant variations in the effectiveness of the wing in generating lift, drag and thrust forces across different segments and regions of the wing. We employ a force partitioning method to analyse the causality of pressure loads over the wing, demonstrating that vortex-induced pressure forces are dominant while added-mass contributions to aerodynamic loads are minimal. This approach also elucidates the role of various flow structures in shaping pressure distributions. Finally, we compare the fully articulated, flexible bat wing with equivalent stiff wings derived from the same kinematics, demonstrating the critical impact of wing articulation and deformation on aerodynamic efficiency.

This article explores the emergence of nuclear medicine as a clinical research field in post-war Europe, focusing on the shaping of its disciplinary boundaries in the context of geopolitical divisions. It examines how this speciality was negotiated and established, highlighting the role of international exchanges involving researchers, radioisotopes and technologies. By bringing together physicists, radiologists and internists, nuclear medicine gained momentum in the 1950s, leading to the formation of first dedicated scientific societies, conferences and journals. Physicians working in Austria played an influential role in this identity-building process on the European level. They benefited from the networks of the International Atomic Energy Agency in Vienna, the country’s political neutrality and their early emphasis on thyroid diseases. We argue that nuclear medicine emerged out of scientific-diplomatic practices that unified this diverse field of research while also setting it apart from more established clinical specialities. We will trace how physicians and medical facilities in Austria came into play as partners on both sides of the Iron Curtain and navigated these intertwined diplomatic and disciplinary dynamics, facilitating intra-European cooperation on epistemic, political and social levels.

Governments shape policy outcomes using two distinct mechanisms: rules and discretion. A simple decomposition strategy is proposed for distinguishing between these policymaking mechanisms on income inequality in the American states from 1986 to 2020. This analytical strategy is easily applicable to other policy settings. The statistical evidence, for the most part, that income inequality observed in the American states is generally unaffected by both TELs and partisan control of state governments—the lone exception being unified Republican state governments operating under a TEL. The decomposition evidence, however, shows that this is primarily the result of discretionary policymaking differences among partisan governments. This study underscores the importance of disentangling policy mechanisms that jointly occur when evaluating the consequences of government policymaking authority.

We consider the drawing of a hollow Newtonian fibre with temperature-dependent viscosity. The drawing is affected by surface tension, inertia, hole pressurisation and externally applied cooling. We apply long-wavelength techniques to determine the steady states and examine their stability. In the presence of surface tension but with no cooling or internal hole pressure, we show the counter-intuitive result that the hole radius at the outlet of the device is a non-monotonic function of the hole radius at the inlet. We also show that if the internal hole is pressurised and the hole size at the inlet is sufficiently large, then the exit temperature of the fibre is a non-monotonic function of the applied cooling rate. We have found a number of surprising mechanisms related to how the various physical effects influence the stability of drawing. For the isothermal case, we show that increasing the internal hole pressure has a destabilising effect for non-zero surface tension while the stability is completely independent of the internal hole pressure for zero surface tension. We further show that there is a complicated interplay between internal hole pressure, external cooling and surface tension in determining the stability and that it is possible that increasing the hole size at the inlet can act to destabilise, then stabilise and finally destabilise the flow. We discuss the mechanisms that determine the counter-intuitive steady-state behaviour and stability.

This study seeks a low-rank representation of turbulent flow data obtained from multiple sources. To uncover such a representation, we consider finding a finite-dimensional manifold that captures underlying turbulent flow structures and characteristics. While nonlinear machine-learning techniques can be considered to seek a low-order manifold from flow field data, there exists an infinite number of transformations between data-driven low-order representations, causing difficulty in understanding turbulent flows on a manifold. Finding a manifold that captures turbulence characteristics becomes further challenging when considering multi-source data together due to the presence of inherent noise or uncertainties and the difference in the spatiotemporal length scale resolved in flow snapshots, which depends on approaches in collecting data. With an example of numerical and experimental data sets of transitional turbulent boundary layers, this study considers an observable-augmented nonlinear autoencoder-based compression, enabling data-driven feature extraction with prior knowledge of turbulence. We show that it is possible to find a low-rank subspace that not only captures structural features of flows across the Reynolds number but also distinguishes the data source. Along with machine-learning-based super-resolution, we further argue that the present manifold can be used to validate the outcome of modern data-driven techniques when training and evaluating across data sets collected through different techniques. The current approach could serve as a foundation for a range of analyses including reduced-complexity modelling and state estimation with multi-source turbulent flow data.

Flow dynamics around a stationary flat plate near a free surface is investigated using time-resolved two-dimensional particle image velocimetry. The study examines variations in angle of attack ($\theta =0^\circ {-}35^\circ {}$), Reynolds number ($Re$ $\approx$ $10^3$$-$3 $\times$ $10^4$) and plate proximity to the free surface ($H^*$). Under symmetric boundary conditions ($H^*\geqslant {15}$), increasing $\theta$ intensifies fluid–plate interaction, resulting in the shedding of leading-edge and trailing-edge vortices (LEV and TEV), each characterised by distinct strengths and sizes. In both symmetric ($H^*\geqslant {15}$) and asymmetric ($H^*=5$) boundary conditions at $\theta \lt 5^\circ {}$, fluid flow follows the contour of the plate, unaffected by Reynolds number. However, at $H^*=5$, three flow regimes emerge: the first Coanda effect (CI), regular shedding (RS) and the second Coanda effect (CII), each influenced by $\theta$ and $Re$. The CI regime dominates at lower angles ($5^\circ {}\leqslant \theta \leqslant 25^\circ {}$) and $Re \leqslant 12\,500$, featuring a Coanda-induced jet-like flow pattern. As the Reynolds number increases, the flow transitions into the RS regime, leading to detachment from the upper surface of the plate. This detachment results in the formation of LEV and TEV in the wake, along with surface deformation, secondary vortices and wavy shear layers beneath the free surface. At $22\,360\lt Re \leqslant 32\,200$ and $5^\circ {} \leqslant \theta \leqslant 25^\circ {}$, in the CII regime, significant surface deformation causes the Coanda effect to reattach the flow to the plate, forming a unique jet-like flow.

The present study investigates the gravity-driven settling dynamics of non-Brownian suspensions consisting of spherical and cubic particles within a triply periodic domain. We numerically examine the impact of solid volume fraction on the evolving microstructure of the suspension using the rigid multiblob method under Stokes flow conditions. Our simulations match macroscopic trends observed in experiments, and align well with established semi-empirical correlations across a broad range of volume fractions. At low to moderate solid volume fractions, the settling mechanism is governed primarily by hydrodynamic interactions between the particles and the surrounding fluid. However, frequent collisions between particles in a highly packed space tend to suppress velocity fluctuations at denser regimes. For dilute suspensions, transport properties are shaped predominantly by an anisotropic microstructure, though this anisotropy diminishes as many-body interactions intensify at higher volume fractions. Notably, cubic particles exhibit lower anisotropy in velocity fluctuations compared to spherical particles, owing to more efficient momentum and energy transfer from the gravity-driven direction to transverse directions. Finally, bidisperse suspensions with mixed particle shapes show enhanced velocity fluctuations, driven by shape-induced variations in drag and increased hydrodynamic disturbances. These fluctuations in turn affect the local sedimentation velocity field, leading to the segregation of particles in the mixture.

The aim of the article is to examine the efficiency of Long-Term Care Sector in Poland. Detailed analysis of the level of dependency was carried out, measured by the number, structure and sequence of ADL loss among residents based on data collected between 2021 and 2022 in Polish private rest homes, social residential homes and nursing homes. We have used 3 scenarios based on care and home modernization vouchers to calculate alternative public LTC costs. In the 5 years’ perspective, it seems that solutions based on care vouchers: home care vouchers for 0–2 ADL group without cognitive impairment or mental disorders and inpatient care vouchers for 0–2 ADL group with mentioned impairments, lead to the highest public savings. Better allocation of people with a low level of dependency and without cognitive impairment results in lower public spending on LTC and increased access for people with a higher level of dependency.