M. Asai 교수

A stabilized Incompressible Smoothed Particle Hydrodynamics (ISPH) is proposed to simulate free surface flow problems. In the ISPH, pressure is evaluated by solving pressure Poisson equation using a semi‐implicit algorithm based on the projection method. Even if the pressure is evaluated implicitly, the unrealistic pressure fluctuations cannot be eliminated. In order to overcome this problem, there are several improvements. One is small compressibility approach, and the other is introduction of

$\ensuremath{\alpha}\mathrm{\text{\ensuremath{-}}}\ensuremath{\gamma}$ and $\ensuremath{\alpha}$-electron coincidence spectroscopy for a short-lived heavy actinide nucleus $^{257}\mathrm{No}$ (${T}_{1/2}=24.5\text{ }\text{ }\mathrm{s}$) has been performed using a gas-jet transport system and an on-line isotope separator. Spin-parities of excited states in $^{253}\mathrm{Fm}$ fed by the $\ensuremath{\alpha}$ decay of $^{257}\mathrm{No}$ have been identified on the basis of the measured internal c

In this paper, a new particle-based fluid–rigid-body interaction simulator for violent free-surface flow problems is developed. The incompressible Smoothed Particle Hydrodynamics (ISPH) method has been proven to produce a smooth and accurate pressure distribution of free-surface fluid flow with breaking and fragmentation. Computed hydrodynamic forces can be applied onto rigid bodies, which may simultaneously experience contact or impact with the surrounding wall boundaries or another rigid body.

In this paper, we propose a class of decoupled first- and second-derivatives models for the Smoothed Particle Hydrodynamics (SPH) method, which were inspired by the Lagrangian Differencing Dynamics (LDD) (Bašić et al., 2018) and (Bašić et al., 2022) and arranged to the SPH framework. Being extensions of existing gradient and Laplacian SPH models, the proposed decoupled models include the cross-derivatives, which are crucial to ensure 2nd-order accuracy. Under the framework of the proposed class

$\ensuremath{\beta}$-decay half-lives of new neutron-rich isotopes ${}^{167}\mathrm{Tb}$ and ${}^{168}\mathrm{Tb}$ produced in the 20 MeV proton-induced fission of ${}^{238}\mathrm{U}$ have been determined to be 19.4(27) s and 8.2(13) s, respectively, using a gas-jet coupled on-line isotope separator. The present half-lives and those of the recently identified nuclei ${}^{159}\mathrm{Pm},$ ${}^{161}\mathrm{Sm},$ ${}^{165}\mathrm{Gd},$ ${}^{166}\mathrm{Tb}$ were compared with theoretical predicti

Excited states in $^{251}\mathrm{Fm}$ populated via the $\ensuremath{\alpha}$ decay of $^{255}\mathrm{No}$ are studied in detail through $\ensuremath{\alpha}$-$\ensuremath{\gamma}$ coincidence and $\ensuremath{\alpha}$ fine-structure measurements. Five excited states reported previously in $^{251}\mathrm{Fm}$ are firmly established through the $\ensuremath{\alpha}$-$\ensuremath{\gamma}$ coincidence measurement, and rotational bands built on one-quasiparticle states are newly established through