Abstract We evaluate the allowed $$\beta^-$$-decay properties of nuclei with $Z = 8$$–$$15$ systematically under the framework of the nuclear shell model using the valence space Hamiltonians derived from modern ab initio methods, such as in-medium similarity renormalization group and coupled-cluster theory. For comparison we also show results obtained with fitted interaction derived from chiral effective field theory and phenomenological universal $sd$-shell Hamiltonian version B interaction. We have performed calculations for O $$\rightarrow$$ F, F $$\rightarrow$$ Ne, Ne $$\rightarrow$$ Na, Na $$\rightarrow$$ Mg, Mg $$\rightarrow$$ Al, Al $$\rightarrow$$ Si, Si $$\rightarrow$$ P, and P $$\rightarrow$$ S transitions. Theoretical results for $B(GT)$, $$\log ft$$ values, and half-lives are discussed and compared with the available experimental data.
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The Per-Tau Shell: A Giant Star-forming Spherical Shell Revealed by 3D Dust Observations
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The pursuit of materials with enhanced functionality has led to the emergence of metamaterials—artificially engineered materials whose properties are determined by their structure rather than composition. Traditionally, the building blocks of metamaterials are arranged in fixed positions within a lattice structure. However, recent research has revealed the potential of mixing disconnected building blocks in a fluidic medium. Inspired by these recent advances, here we show that by mixing highly deformable spherical capsules into an incompressible fluid, we can realize a ‘metafluid’ with programmable compressibility, optical behaviour and viscosity. First, we experimentally and numerically demonstrate that the buckling of the shells endows the fluid with a highly nonlinear behaviour. Subsequently, we harness this behaviour to develop smart robotic systems, highly tunable logic gates and optical elements with switchable characteristics. Finally, we demonstrate that the collapse of the shells upon buckling leads to a large increase in the suspension viscosity in the laminar regime. As such, the proposed metafluid provides a promising platform for enhancing the functionality of existing fluidic devices by expanding the capabilities of the fluid itself.more » « less