181 citations · 324 across the 21 of their papers we have counts for
21 papers
Viscous friction acting on a solid disk falling in confined fluid: lessons for the scaling analysis
Nana Tanaka, Ko Okumura
We fill a viscous liquid in a vertically stood cell of millimeter thickness, called the Hele-Shaw cell, and insert a disk in the liquid whose thickness is smaller than the cell thi…
Rising obstacle in a one-layer granular bed induced by continuous vibrations: two dynamical regimes governed by vibration velocity
Hui Zee Then, Teruyo Sekiguchi, Ko Okumura
Rising motion of an obstacle in a vibrated granular medium is a classic problem of granular segregation, and called the Brazil nut (BN) effect. The controlling vibration parameters…
Liquid-liquid capillary replacement in a horizontal geometry: universal dynamics and replacement time
Julie André, Ko Okumura
Capillary invasion of a liquid into an empty tube, which is called capillary rise when the tube axis is in the vertical direction, is one of the fundamental phenomena representing…
Continuity and discontinuity of kirigami's high-extensibility transition: a statistical-physics viewpoint
Midori Isobe, Ko Okumura
Recently, kirigami's high extensibility has been understood as a transition in the force-elongation curve. In this paper, we consider a model, which modifies our previous model, to…
Crack propagation under static and dynamic boundary conditions
Yuko Aoyanagi, Ko Okumura
Velocity jumps observed for crack propagation under a static boundary condition have been used as a controlling factor in developing tough rubbers. However, the static test require…
Toughening in a nacre-like soft-hard layered structure due to weak nonlinearity in the soft layer
Yuko Aoyanagi, Ko Okumura
Recently, it has been found experimentally that hydrated nacre exhibits a nonlinear mechanical response. While mechanical nonlinearity has been shown to be important in other biolo…