Tumbling motion of a single chain in shear flow: a crossover from Brownian to non-Brownian behavior

We present numerical results for the dynamics of a single chain in steady shear flow. The chain is represented by a bead-spring model, and the smoothed profile method is used to accurately account for the effects of thermal fluctuations and hydrodynamic interactions acting on beads due to host fluids. It is observed that the chain undergoes tumbling motions and that its dimensionless frequency F depends only on the Peclet number Pe with a power law. The exponent of Pe clearly changes from 2/3 to 1 around the critical Peclet number, indicating that the crossover reflects the competition of thermal fluctuation and shear flow. The presented numerical results agree well with our theoretical analysis based on Jeffery's work

Implementation of Lees-Edwards periodic boundary conditions for direct numerical simulations of particle dispersions under shear flow

A general methodology is presented to perform direct numerical simulations of particle dispersions in a shear flow with Lees-Edwards periodic boundary conditions. The Navier-Stokes equation is solved in oblique coordinates to resolve the incompatibility of the fluid motions with the sheared geometry, and the force coupling between colloidal particles and the host fluid is imposed by using a smoothed profile method. The validity of the method is carefully examined by comparing the present numerical results with experimental viscosity data for particle dispersions in a wide range of volume fractions and shear rates including nonlinear shear-thinning regimes

A Framework of Stock-based System Design and Management toward a Steady-state Society

To ensure environmental sustainability, the flow of natural resource extraction must be reduced and stabilized at a suitable level. However, environmental sustainability and an infinitely growing economy are incompatible. To resolve this contradiction, a manufacturing system based on the idea of a sustainable steady-state society is proposed. In such a society, the value of stocks will be more important than that of flows. The purpose of this paper is to propose a framework of an approach for stock-based system design and management suitable for a steadystate society. The approach is supported by new life cycle simulation (LCS) technologies for dynamic handling of in-use stock, such as industrial products and systems. One is an LCS for system of systems that considers interactions among multiple models of the product life cycle. The other is a data assimilation LCS to modify internal data or LCS models based on real data acquired from the field. Concepts and preliminary studies of these LCS technologies show what can be expected for the proposed framework.Hideki Kobayashi. “A Framework of Stock-based System Design and Management toward a Steady-state Society”. 2016 Electronics Goes Green 2016+ (EGG 2016). Berlin, September 7-9, 2016, Fraunhofer IZM. 2016

Estimation of Exit Behaviors--Panel Data Analysis of an Experiment with Intergroup Mobility

We estimate exit behavior in a repeated social dilemma situation with intergroup mobility, using experimental data. Estimated results show that absolute levels of cooperation of others in one’s own group is a significant determinant. Also, the difference between the absolute levels of cooperation and the cooperation index based on a subject’s actual choices for cooperation, from the first some periods, is significant. Information about other groups is not important. Based on these results, we draw the following conclusions: (1) subjects care about the information concerning their own group. (2) the higher the cooperation index for a subject, the higher is the probability that he/she will move, given the same level of cooperation of others.

Significance of the Ikenotaira Interstadial Indicated by Moraines on Mt. Kumazawa of the Kiso Mountain Range, Central Japan

From tephra cover on the outermost moraine in the Ikenotaira cirque on Mt. Kumazawa of the Kiso mountain range, a small amount of air-borne scoria from Ontake volcano was collected. The scoria is identified with that of the scoria-fall deposit Sc-I which within the section of the air-laid Younger tephra unit of the so-called Shinshu Loam Formation lies in the basal part. The radiometric age of the Kisogawa volcanic mudflow associated with the Sc-I approximates 27,0001t C years ago, indicating that the outermost moraine be assigned to the pre-Paudorf glacial stade, whereas the upper two moraines should postdate the Paudorf interstadial. The interval indicated between the lower two moraines is emphasized to establish the Late Quaternary chronology. The date of the Ikenotaira interstadial also supports that simultaneous uprise of sea level may have taken place.Article信州大学理学部紀要 1(2): 97-113(1967)departmental bulletin pape

Reentrant transition in the shear viscosity of dilute rigid rod dispersions

The intrinsic viscosity of a dilute dispersion of rigid rods is studied using a recently developed direct numerical simulation (DNS) method for particle dispersions. A reentrant transition from shear-thinning to the 2nd Newtonian regime is successfully reproduced in the present DNS results around a Peclet number ${\rm Pe}=150$, which is in good agreement with our theoretical prediction of ${\rm Pe}=143$, at which the dynamical crossover from Brownian to non-Brownian behavior takes place in the rotational motion of the rotating rod. The viscosity undershoot is observed in our simulations before reaching the 2nd Newtonian regime. The physical mechanisms behind these behaviors are analyzed in detail