Anomaly of the geomagnetic Sq variation in Japan: effect from 3-D subterranean structure or the ocean effect?

Many years ago Rikitake et al. described the anomalous behaviour of the vertical component Z of the geomagnetic solar quiet (Sq) daily variation field at observatories in central and northern Japan - namely about 2 hr shift of the local noontime peak towards morning hours. They suggested that this anomaly is associated with the anomalous distribution of electrical conductivity in the mantle beneath central Japan. Although a few works have been done to confirm or argue this explanation, no clear answer has been obtained so far. The goal of this work is to understand the nature of this anomaly using our 3-D forward solution. The conductivity model of the Earth includes oceans of laterally variable conductance and conducting mantle either spherically symmetric or 3-D underneath. Data from six Japanese observatories at four seasons for two different years of the solar cycle are analysed. As an inducing ionospheric (Sq) current system, we use those provided by the Comprehensive Model (CM4) of Sabaka et al. Our analysis clearly demonstrates that 3-D induction in the ocean is responsible for the anomalous behaviour of Z daily variations in this region. We also show that the effects from a suite of 3-D mantle models that include mantle wedge and subducting slab are minor compared with the ocean effec

Evolution of the current system during solar wind pressure pulses based on aurora and magnetometer observations

Additional file 2: Figure S2. Same as Additional file 1 but for the July 14, 2012, event

Droplet Breakup in Flow Past an Obstacle: A Capillary Instability Due to Permeability Variations

In multiphase flow in confined geometries an elementary event concerns the interaction of a droplet with an obstacle. As a model of this configuration we study the collision of a droplet with a circular post that spans a significant fraction of the cross-section of a microfluidic channel. We demonstrate that there exist conditions for which a drop moves completely around the obstacle without breaking, while for the same geometry but higher speeds the drop breaks. Therefore, we identify a critical value of the capillary number above which a drop will break. We explain the results with a one-dimensional model characterizing the flow in the narrow gaps on either side of the obstacle, which identifies a surface-tension–driven instability associated with a variation in the permeability in the flow direction. The model captures the major features of the experimental observations.Harvard University (MRSEC (DMR-0820484))Schlumberger-Doll Research Cente

Single cell tracking to analyze biofilm formation

科学研究費助成事業 研究成果報告書：若手研究(B)2017-2018課題番号 : 17K15410research repor

Bilayer networks within a hydrogel shell: A robust chassis for artificial cells and a platform for membrane studies

The ability to make artificial lipid bilayers compatible with a wide range of environments, and with sufficient structural rigidity for manual handling, would open up a wealth of opportunities for their more routine use in realworld applications. Although droplet interface bilayers (DIBs) have been demonstrated in a host of laboratory applications, from chemical logic to biosynthesis reaction vessels, their wider use is hampered by a lack of mechanical stability and the largely manual methods employed in their production. Multiphase microfluidics has enabled us to construct hierarchical triple emulsions with a semipermeable shell, in order to form robust, bilayer-bound, droplet networks capable of communication with their external surroundings. These constructs are stable in air, water, and oil environments and overcome a critical obstacle of achieving structural rigidity without compromising environmental interaction. This paves the way for practical application of artificial membranes or droplet networks in diverse areas such as medical applications, drug testing, biophysical studies and their use as synthetic cells

Fabrication and electrokinetic motion of electrically anisotropic Janus droplets in microchannels

This is the peer reviewed version of the following article: Li, M. and Li, D. (2017), Fabrication and electrokinetic motion of electrically anisotropic Janus droplets in microchannels. ELECTROPHORESIS, 38: 287–295 which has been published in final form at http://dx.doi.org/10.1002/elps.201600310. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.This paper presents experimental investigations of the fabrication and the motion of electrically anisotropic Janus droplets in a microchannel under externally applied direct current (DC) electrical field. The fabrication method of the Janus droplets is presented first. To begin, oil droplets are coated uniformly with positively charged nanoparticles in the aluminum oxide nanoparticle suspension. The electrically anisotropic Janus droplets are formed when the nanoparticles are accumulated to one side of the droplets in response to externally applied DC electric field. The surface coverage of the Janus droplets by nanoparticles can be adjusted by controlling the concentration of the nanoparticle suspension. The flow fields around the Janus droplets moving in a microchannel were observed with tracing particles. Finally, the electrokinetic velocity of the Janus droplets in a microchannel was measured. The effects of the strength of the electrical field, the surface coverage of the Janus droplets by nanoparticles, the size of the droplets as well as the electrolyte concentration on the electrokinetic velocity of the Janus droplets were studied.Natural Sciences and Engineering Research Council of Canad

<i style="">In-Situ</i> Monitoring of Phase Transition and Microstructure Evolution in Ni-Based Superalloys by Electrical Resistivity:Direct Comparison With Differential Scanning Calorimetry and Application to Case Studies

In this study, resistivity measurements are made during continuous heating and cooling on four different Ni-based superalloys of different grain structures and with different phases (i.e., γ′ and carbide). The results are directly compared with differential scanning calorimetry (DSC) profiles to identify the material’s resistivity response. The resistivity measurements have been performed using an electro-thermal mechanical testing (ETMT) system having a capability of heating and cooling a sample at a rate of up to 100 K/s by Joule heating, which is not possible with standard heating methods used in previous in-situ microstructure analysis approaches. By comparing different precipitate variations and thermal histories, γ′ volume fraction and precipitate number density are found to be the most important factors determining the resistivity of the materials. In-situ resistivity measurement was applied to several case studies to show that it can provide microstructural information in complex high temperature experiments.<br/

Overheating of Waspaloy:Effect of cooling rate on flow stress behavior

During service of a gas turbine engine, components may suffer instant overheating which is a concern to safe operations. Effect of short overheating on the tensile properties of a Ni-based superalloy Waspaloy has been studied due to its significant importance for practical applications. The results have shown that a combination of near supersolvus overheating at 1000 °C with very rapid cooling at a rate of 50 K/s is most detrimental case to the tensile properties of the material. This is attributed to the absence of γ' and carbide re-precipitation and growth during cooling period. Microstructure change during overheating and cooling has been deduced using in-situ resistivity measurements. This work provides evidence that multilateral measurements including resistivity can shed light on the failure controlling parameters