10 citations · 49 across the 12 of their papers we have counts for
13 papers
Amplified transport variability in granular slope flows near the critical angle
Fumiaki Nakai, Yuto Sasaki
Mechanical disturbances such as seismic shaking can set a granular slope in motion. Understanding the resulting transport before arrest is important for predicting topographic chan…
Granular Rods Fall Faster in Denser Obstacle Fields
Fumiaki Nakai, Hiroaki Katsuragi
How does particle shape affect driven transport through obstacle fields? We simulate a dissipative rod falling under gravity through randomly placed fixed obstacles. For sufficient…
Steady shear rheology of a granular crystal containing a single dislocation
Fumiaki Nakai
Monodisperse granular particles can form crystals whose yielding behavior is strongly affected by dislocations and differs markedly from that of conventional amorphous granular mat…
Anomalous phonon dispersion near yielding in athermal crystals
Fumiaki Nakai, Michio Otsuki, Kuniyasu Saitoh +1
Vibrational properties of ordered athermal solids near yielding remain poorly understood. We show that yielding in a sheared crystal is governed not by a single localized instabili…
Dislocation Glides in Monolayered Granular Media: Effect of Lattice Constant
Fumiaki Nakai, Takashi Uneyama, Yuto Sasaki +2
A recent study demonstrated that granular crystals containing a single dislocation exhibit dislocation glide analogous to that observed in atomic-scale crystals, resulting in plast…
Dislocation Glides in Granular Media
Fumiaki Nakai, Takashi Uneyama, Yuto Sasaki +2
Atomic crystals with dislocations deform plastically at low stresses via dislocation glide. Whether dislocation glide occurs in macroscopic frictional granular media has remained u…
Reducing segregation in vibrated binary-sized granular mixtures by excessive small particle introduction
Fumiaki Nakai, Kiwamu Yoshii
We numerically examine binary-sized granular mixtures confined between two parallel walls subjected to vertical vibration using the discrete element method. For a size ratio of …
Brownian Yet Non-Gaussian Diffusion of a Light Particle in Heavy Gas: Lorentz Gas Based Analysis
Fumiaki Nakai, Takashi Uneyama
Non-Gaussian diffusion was recently observed in gas mixtures with mass and fraction contrast [F. Nakai et al, Phys. Rev. E 107, 014605 (2023)]. The mean square displacement of a mi…
Gas Diffusion in Cement Pastes: An Analysis using a Fluctuating Diffusivity Model
Fumiaki Nakai, Takato Ishida
This work propose an application of the concept of fluctuating diffusivity to the diffusion of gas molecules in cementitious materials, particularly through a two-state fluctuating…
Increase in rod diffusivity emerges even in Markovian nature
Fumiaki Nakai, Martin Kröger, Takato Ishida +3
Rod-shaped particles embedded in certain matrices have been reported to exhibit an increase in their center of mass diffusivity upon increasing the matrix density. This increase ha…
Fluctuating Diffusivity Emerges even in Binary Gas Mixtures
Fumiaki Nakai, Yuichi Masubuchi, Yuya Doi +2
Diffusivity in some soft matter and biological systems changes with time, called the fluctuating diffusivity. In this work, we propose a novel origin for fluctuating diffusivity ba…
Short time dynamics of tracer in ideal gas
Fumiaki Nakai, Yuichi Masubuchi, Takashi Uneyama
A small tagged particle immersed in a fluid exhibits the Brownian motion and diffuses at the long-time scale. Meanwhile, at the short-time scale, the dynamics of the tagged particl…
Effect of Inertia on Linear Viscoelasticity of Harmonic Dumbbell Model
Takashi Uneyama, Fumiaki Nakai, Yuichi Masubuchi
The overdamped (inertialess) dumbbell model is widely utilized to study rheological properties of polymers or other soft matters. In most cases, the effect of inertia is merely neg…