What is the future for nuclear fission technology? A technical opinion from the Guest Editors of VSI NFT series and the Editor of the Journal Nuclear Engineering and Design

The Nuclear Fission Technology (NFT) series of Virtual Special Issues (VSIs) for the Journal Nuclear Engineering and Design (J NED) was proposed in 2023, including the request to potential authors of manuscript to address the following questions: o For how long will (water-cooling based) large size nuclear reactor survive? o Will water-technology based SMRs displace large reactors? o Will non-water-cooling technology SMRs and micro-reactors have an industrial deployment? o Will breeding technology, including thorium exploitation, have due relevance? o Will ‘nuclear infrastructure’ (fuel supply, financial framework, competence by regulators for new designs, waste management, etc.) remain or be sufficiently robust? Several dozen Guest Editors (GEs), i.e., the authors of the present document, managed the activity together with the Editor-in-Chief (EiC) of the journal. More than one thousand scientists contributed 470+ manuscripts, not evenly distributed among the geographical regions of the world and not necessarily addressing directly the bullet-questions, but certainly providing a view of current research being done. Key conclusions are as follows: (a) Large size reactors are necessary for a sustainable and safe exploitation of nuclear fission technology; (b) The burning of 233U (from thorium) and 239Pu (from uranium) is unavoidable, as well as recycling residual uranium currently part of waste; (c) Nuclear infrastructures in countries that currently use, or are entering the use of, fission energy for electricity production need a century planning; (d) The adoption of small reactors for commercial naval propulsion, hydrogen production and desalination is highly recommended

Atorvastatin versus placebo in ICU patients with COVID-19: ninety-day results of the INSPIRATION-S trial

Background In the INSPIRATION-S trial, atorvastatin versus placebo was associated with a nonsignificant 16% reduction in 30-day composite of venous/arterial thrombosis or death in intensive care unit (ICU) patients with COVID-19. Thrombo-inflammatory response in coronavirus disease 2019 (COVID-19) may last beyond the first 30 days.Methods This article reports the effects of atorvastatin 20 mg daily versus placebo on 90-day clinical and functional outcomes from INSPIRATION-S, a double-blind multicenter randomized trial of adult ICU patients with COVID-19. The main outcome for this prespecified study was a composite of adjudicated venous/arterial thrombosis, treatment with extracorporeal membrane oxygenation (ECMO), or all-cause mortality. Functional status was assessed with the Post-COVID-19 Functional Scale.Results In the primary analysis, 587 patients were included (age: 57 [Q1–Q3: 45–68] years; 44% women). By 90-day follow-up, the main outcome occurred in 96 (33.1%) patients assigned to atorvastatin and 113 (38.0%) assigned to placebo (hazard ratio [HR]: 0.80, 95% confidence interval [CI]: 0.60–1.05, p = 0.11). Atorvastatin in patients who presented within 7 days of symptom onset was associated with reduced 90-day hazard for the main outcome (HR: 0.60, 95% CI: 0.42–0.86, p interaction = 0.02). Atorvastatin use was associated with improved 90-day functional status, although the upper bound CI crossed 1.0 (ORordinal: 0.64, 95% CI: 0.41–1.01, p = 0.05).Conclusion Atorvastatin 20 mg compared with placebo did not significantly reduce the 90-day composite of death, treatment with ECMO, or venous/arterial thrombosis. However, the point estimates do not exclude a potential clinically meaningful treatment effect, especially among patients who presented within 7 days of symptom onset (NCT04486508).Thrombosis and Hemostasi

cohesion and conflict in transnational merchant families

How do people negotiate the diversity of positionalities within kin groups? Through a diachronic approach, I investigate how Ali and Jalal, two merchants with Azeri and Gilaki ethnic identifications who came to Hamburg in the 1930s, mobilized kin to generate capital along the lines of generation, gender, and age. The reader simultaneously learns about the local history of Iranian immigration. Building on literature about historical merchant networks, the social organization of the Iranian marketplace (bazaar), the anthropology of kinship and transnational families, I question the social cohesion on which Aihwa Ong's study of flexible capital creation relies. The material suggests that the experience of family relations influences agents' positioning in the local Iranian social field

The Influence of Geometry on the Frictional Sliding of ∧ and ∨ Shaped Interlocking Joints in Masonry Assemblages

Applications of interlocking blocks improving the sliding resistance of masonry joints have recently been of significant interest to architects and structural engineers. In this framework, several works have studied the load capacity improvement of different joint shapes using various numerical and experimental analyses. However, applications of simplified and yet accurate analytical methods like limit analysis to interlocking blocks are rather unexplored and limited to a few interlocking joint shapes. To develop such a simplified analytical approach for interlocking assemblages with ∧ and ∨ shaped joints, this paper explores relationships between the shear capacities of flat and interlocking joints, allowing to abstract an assemblage of interlocking blocks to its equivalent assemblage with flat joints. This work specifically studies the interaction among friction, dilation, and inclination angles of the joints. To this aim, first the relationships between a flat and an interlocking joint of two stacked blocks are fully explored and then, the associative solution for an assemblage of two wedge blocks with flat faces is compared with the non-associative solution of the same assemblage with ∧ and ∨ shaped interlocking joints. Discrete element models using 3DEC are implemented to carry out the comparative analyses, in which the blocks are modelled as rigid units and the ultimate lateral load capacity of the assemblages is recorded

Interlocking joint shape optimization for structurally informed design of block assemblages

This paper presents a computer aided design tool that analyses the structural feasibility of interlocking assemblages with orthotropic sliding resistance and automatically adjusts the assemblage shape to remove the infeasibility. First, the static problem of limit analysis is extended to the corrugated interfaces. To model different bond patterns and openings, an assemblage is abstracted to different types of joints representing the dry joints between the blocks, joints inside the blocks, and the excluded joints where the openings are located. This problem is then reformulated to measure the structural infeasibility due to the sliding constraint violation. The so-called sliding infeasibility measure shows how far an infeasible model is to become feasible. This problem is used as the objective function of a shape optimization algorithm that minimizes the sliding infeasibility measure through automated change of the interlocking joints, by which the model becomes structurally feasible. The optimization is validated using the discrete element analysis

Torsion–Shear Behaviour at Interlocking Joints: Calibration of Discrete Element-Deformable Models Using Experimental and Numerical Analyses

An interlocking block is a concave polyhedron with non-planar joints connecting the blocks together. The possibility of the fracture within a masonry interlocking block is a major challenge that has remained rather unexplored yet. Different fracture scenarios can be taken into account through considering the crack planes at which the block can be set apart. The plastic failure inside the block can also be represented through the continuum plastic deformation of the block composed of continuum finite elements. For an interlocking block with a cuboid projection above (lock), this paper intends to analyse the torsion–shear behaviour of the lock experimentally and numerically based on the discrete element method. Two strategies are developed to model a concave block: the lock and main body of an interlocking block are set to be rigid and connected with a cohesive contact in between; the concave interlocking polyhedron is set to be deformable with elasto-plastic behaviour. Given the same material properties, the torsion–shear capacities of the lock obtained by the two numerical models and the experimental test are compared to each other. A parametric analysis is then provided to calibrate the deformable model