Article
Materials Science, Multidisciplinary
Alexander V. Savin
Summary: This study demonstrates using molecular dynamics that the motion of carbon nanoparticles on a thermalized graphene sheet lying on a flat substrate can be described as particles moving in a viscous medium with a constant coefficient of friction. The value of this coefficient depends on the temperature and particle size, and there are two types of effective friction: diffusion and ballistic.
Article
Physics, Applied
Norio Inui
Summary: Strong diamagnetic interactions allow carbon materials to levitate in the atmosphere, with factors such as Brownian motion and attractive surface forces affecting stability. The size of the nanomaterial affects stability, with the Casimir interactions potentially disrupting levitation.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Robotics
Grazia Zambella, Robert Schuller, George Mesesan, Antonio Bicchi, Christian Ott, Jinoh Lee
Summary: This article proposes a new robust strategy for humanoids to stand up in challenging scenarios. It utilizes the concept of three-dimensional divergent component of motion and passivity-based whole-body control. The strategy maximizes the push forces applied to the robot's center of mass for agile whole-body recovery motion, and then reduces these forces to stabilize the robot in an upward position. The effectiveness of the proposed method is validated through simulations and experiments on the humanoid TORO.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2023)
Article
Geography, Physical
Mads Domgaard, Kristian K. Kjeldsen, Flora Huiban, Jonathan L. Carrivick, Shfaqat A. Khan, Anders A. Bjork
Summary: Glacial lake outburst floods (GLOFs) from ice-dammed lakes in Greenland have significant impacts on local ice dynamics, geomorphological changes, and flooding hazards. This study reconstructed the volume changes of 14 GLOFs between 2007 and 2021 at Russell Glacier in West Greenland using high-resolution digital elevation models and aerial surveys. The results provide one of the most comprehensive and longest records of ice-dammed lake drainages in Greenland to date. The study also highlights the thinning of the local ice dam and the potential changes in drainage routes and volumes.
Article
Chemistry, Multidisciplinary
Manabu Chikai, Emi Ozawa, Hiroshi Endo, Shuichi Ino
Summary: The study found that older individuals prefer a forward trunk-inclination motion when standing up, and all participants found it easier to stand when the toilet seat angle was 5 degrees or 10 degrees.
APPLIED SCIENCES-BASEL
(2021)
Article
Multidisciplinary Sciences
Shaquitta Dent, Kelley Burger, Skyler Stevens, Benjamin D. Smith, Jefferson W. Streepey, Manabu Sakakibara
Summary: The study aimed to investigate the impact of music on body sway induced by virtual reality, and the results showed that adjusting music volume did not result in more body sway. Researchers may consider manipulating sound to enhance VR-induced body sway, however, findings from this study do not suggest using volume to do so.
Article
Chemistry, Multidisciplinary
Jiahao Lin, Peng Li, Yingjun Liu, Ziqiu Wang, Ya Wang, Xin Ming, Chao Gao, Zhen Xu
Summary: The large size of graphene sheets can lead to negative size effect due to the formation of wrinkles. By using wrinkle engineering strategy, the size predicament can be resolved, leading to ultra-high mechanical strength and superior functionalities of graphene materials. The origin of this size effect highlights the importance of modulating wrinkles in graphene macroscopic materials.
Article
Chemistry, Physical
Shuang Wen, Yiting Liu, Jinbo Shen, Ping Zhao, Xiao Cai, Yidan Luo, Xinyi Li, Yun-Hao Lu, Fei Song, Wei-Dong Dou
Summary: The packing behavior of organic molecules at the interface of organic and graphene is crucial for graphene-based organic electronics. In this study, the epitaxy growth of two-dimensional ultra-thin pentacene film with a standing-up molecular geometry was observed for the first time on graphene with periodic nano-sized buckling structure. The curvature and strain of graphene were found to be collectively responsible for the standing-up geometry of pentacene and its oriented growth on the graphene surface. This study provides a feasible way for controlling molecular epitaxy on 2D materials interfaces towards functional heterostructures.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Haruyuki Matsuyama, Jun Nakamura
Summary: In this study, the influence of the size of N-GNCs on the ORR activity was investigated. The results suggest that a N-GNC with a size of 13.6 angstrom is a superior electrocatalyst for ORRs and outperforms platinum in terms of U-Max.
Article
Geosciences, Multidisciplinary
G. Q. Wang, T. L. Zhang, M. Y. Wu, S. D. Xiao, G. Wang, Y. Q. Chen, J. C. Sun, M. Volwerk
Summary: A strong current contributed by electrons occurs in the tilted current sheet during the flapping motion. Electrons are non-adiabatic at the neutral sheet, and their pitch angle distributions undergo scattering. The field-aligned current is suggested to be generated by the non-adiabatic electron at the neutral sheet during the flapping motion.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Editorial Material
Astronomy & Astrophysics
Luca Teodori, Kfir Blum, Emanuele Castorina, Marko Simonovic, Yotam Soreq
Summary: In this paper, we discuss the issue of modeling degeneracies in strong lensing measurements of the Hubble parameter H-0. We highlight the importance of considering weak lensing effects associated with different segments of the line of sight, and propose the inclusion of external convergence terms to avoid bias in the inferred value of H-0. We also show that the use of imaging data for multiple strongly-lensed sources cannot fully resolve the mass sheet degeneracy.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Review
Chemistry, Multidisciplinary
Jasimuddin Ahmed, Swadhin K. Mandal
Summary: Phenalenyl, with a nonbonding molecular orbital (NBMO), has been found to have three redox states and is widely used in various research fields such as organic synthesis, material science, computation, and device physics.
Article
Biochemical Research Methods
Sebastian Sachs, Christian Cierpka, Joerg Koenig
Summary: This study provides a deep insight into the influence of acoustically induced flow on the fractionation of suspended particles using quantitative three-dimensional velocity measurements. The results show that broadly extended vortices are formed due to large gradients in the acoustic fields, which are essential for a holistic analysis of the flow phenomena.
Article
Engineering, Marine
Koray Deniz Goral, Hasan Gokhan Guler, Cuneyt Baykal, Ahmet Cevdet Yalciner
Summary: This study investigates the motion and collision of spheres on a horizontal surface under solitary wave attack, revealing key findings about damping rates on porous bottoms, the influence of water levels on sphere motion characteristics, and the difference in terminal velocities between breaking and non-breaking solitary wave cases. It also highlights the significant impact of wave type and water level on collision behavior, while noting the lack of contribution from bottom conditions.
Article
Physics, Fluids & Plasmas
J. T. Gudmundsson, Janez Krek, De-Qi Wen, E. Kawamura, M. A. Lieberman
Summary: The study found that most ionization occurs near the plasma-sheath interfaces in a specific argon discharge, and in the absence of excited states, secondary electrons emitted from the electrodes play a significant role in the ionization process. When excited states and secondary electron emission due to neutral and ion impact on the electrodes are considered, the ionization process transitions from alpha-mode to gamma-mode.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Mechanics
Hongyang Cheng, Stefan Luding, Kuniyasu Saitoh, Vanessa Magnanimo
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2020)
Article
Physics, Multidisciplinary
Atsushi Ikeda, Takeshi Kawasaki, Ludovic Berthier, Kuniyasu Saitoh, Takahiro Hatano
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Multidisciplinary
Kuniyasu Saitoh, Takahiro Hatano, Atsushi Ikeda, Brian P. Tighe
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Multidisciplinary
Kuniyasu Saitoh, Takeshi Kawasaki
FRONTIERS IN PHYSICS
(2020)
Article
Materials Science, Multidisciplinary
Hideyuki Mizuno, Kuniyasu Saitoh, Leonardo E. Silbert
PHYSICAL REVIEW MATERIALS
(2020)
Article
Physics, Multidisciplinary
Norihiro Oyama, Takeshi Kawasaki, Kuniyasu Saitoh
Summary: This study uses molecular dynamics simulations to investigate the mechanical responses of dense packings of soft athermal spheres under finite-rate shear, focusing on the fluctuations in shear stress and interparticle contact number. By defining susceptibility as the ratio of global to local fluctuations, ridges reminiscent of Widom lines around the critical point in an equilibrium phase transition are observed on the volume fraction-shear rate plane.
FRONTIERS IN PHYSICS
(2021)
Article
Chemistry, Physical
Kuniyasu Saitoh
Summary: Microscopic friction between frictional particles affects the critical exponent of avalanche size distributions. The presence of finite friction coefficient leads to larger and closer critical exponents to mean-field predictions. Microscopic slips induce numerous small avalanches, which in turn increase the slope and power-law exponent of avalanche size distributions.
EUROPEAN PHYSICAL JOURNAL E
(2021)
Article
Physics, Multidisciplinary
Kuniyasu Saitoh, Takeshi Kawasaki
Summary: We investigated the characteristics of two-dimensional dense granular flows using molecular dynamics simulations. Our results show that the shear-induced diffusion of granular particles exhibits different behaviors at different time scales, and is also influenced by the contact damping model.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
Kuniyasu Saitoh, Kianoosh Taghizadeh, Stefan Luding
Summary: We numerically investigate the sound properties of disordered dense granular packings in two dimensions. By using linear equations of motion and excluding contact changes from our simulations, we study the evolution of sinusoidal standing waves of granular disks. We vary the strength of normal and tangential viscous forces between the disks in contact to examine the dependence of sound characteristics on contact damping.
FRONTIERS IN PHYSICS
(2023)
Article
Chemistry, Physical
Abhinendra Singh, Kuniyasu Saitoh
Summary: Dense suspensions exhibit significant response to external deformation, which is related to the transition from lubrication to frictional state. Numerical simulations in two dimensions show that the viscosity and diffusivity of frictional non-Brownian spheres increase under characteristic shear stress. A one-to-one relationship between viscosity and diffusivity is proposed, using the length scale associated with collective motions of particles. The power laws describing the relationship between viscosity, diffusivity, and shear stress are insensitive to interparticle friction and system size.
Article
Physics, Fluids & Plasmas
Daisuke Ishima, Kuniyasu Saitoh, Michio Otsuki, Hisao Hayakawa
Summary: Using the Jacobian matrix, a theoretical expression for rigidity and density of states of two-dimensional amorphous solids consisting of frictional grains was obtained in linear response to strain. The dynamical friction caused by slip processes was ignored. The theoretical rigidity matched molecular dynamics simulations and showed a smooth connection to the frictionless limit. Two modes in the density of states were observed for small kT/kN, with rotational modes at low frequencies and translational modes at high frequencies. The rotational band shifted to higher frequencies with an increase in kT/kN and became indistinguishable from the translational band for large kT/kN.
Article
Physics, Fluids & Plasmas
Daisuke Ishima, Kuniyasu Saitoh, Michio Otsuki, Hisao Hayakawa
Summary: The stress-strain curve of two-dimensional frictional dispersed grains interacting with a harmonic potential under finite strain is determined using eigenvalue analysis of the Hessian matrix. The obtained stress-strain curve is in good agreement with simulation results, even in the presence of plastic deformations caused by stress avalanches. Contrary to expectation, the eigenvalues in our model do not indicate any precursors to stress-drop events.
Article
Chemistry, Physical
Kuniyasu Saitoh, Hideyuki Mizuno
Summary: Through numerical investigation, we find that the anomalous sound characteristics in disordered systems depend on the strength of inelastic interactions between particles, and the Ioffe-Regel limit frequencies are also influenced by this factor.
Article
Chemistry, Physical
Kuniyasu Saitoh, Norihiro Oyama, Fumiko Ogushi, Stefan Luding
Correction
Chemistry, Physical
Kuniyasu Saitoh, Norihiro Oyama, Fumiko Ogushi, Stefan Luding
