Vortices around Janus droplets under externally applied electrical field

The final publication is available at Springer via http://dx.doi.org/10.1007/s10404-016-1741-2.In this study, the Janus droplet is an oil droplet covered with aluminum oxide nanoparticles on one side of the droplet surface under applied DC electrical field. The vortices around Janus droplets fixed on a horizontal surface were studied in this paper. A numerical model was set up to simulate the vortices around the Janus droplet in electric field. The simulation results illustrate that the electric field determines the strength of the vortices around a fixed Janus droplet, and the surface coverage of the positively charged nanoparticles on a Janus droplet affects the size and location of the vortices. The numerically predicted results were further validated experimentally by visualizing the vortices around Janus droplets in an externally applied DC electric field. Furthermore, as the Janus droplets are generated in electric field, the surface coverage by the nanoparticles depends on the strength of the electric field; therefore, the effect of the electric field on the nanoparticle covered surface area of a Janus droplet and the vortices was analyzed

Zoom in to the details of human-centric videos

Presenting high-resolution (HR) human appearance is always critical for the human-centric videos. However, current imagery equipment can hardly capture HR details all the time. Existing super-resolution algorithms barely mitigate the problem by only considering universal and low-level priors of im-age patches. In contrast, our algorithm is under bias towards the human body super-resolution by taking advantage of high-level prior defined by HR human appearance. Firstly, a motion analysis module extracts inherent motion pattern from the HR reference video to refine the pose estimation of the low-resolution (LR) sequence. Furthermore, a human body reconstruction module maps the HR texture in the reference frames onto a 3D mesh model. Consequently, the input LR videos get super-resolved HR human sequences are generated conditioned on the original LR videos as well as few HR reference frames. Experiments on an existing dataset and real-world data captured by hybrid cameras show that our approach generates superior visual quality of human body compared with the traditional method.Comment: 5 pages, 6 figures, accepted for presentation at IEEE ICIP 202

Redistribution of mobile surface charges of an oil droplet in water in applied electric field

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.cis.2016.08.006. © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Most researches on oil droplets immersed in aqueous solutions assume that the surface charges of oil droplets are, similar to that of solid particles, immobile and distributed uniformly under external electric field. However, the surface charges at the liquid–liquid interface are mobile and will redistribute under external electric field. This paper studies the redistribution of surface charges on an oil droplet under the influence of the external electrical field. Analytical expressions of the local zeta potential on the surface of an oil droplet after the charge redistribution in a uniform electrical field were derived. The effects of the initial zeta potential, droplet radius and strength of applied electric field on the surface charge redistribution were studied. In analogy to the mobile surface charges, the redistribution of Al2O3-passivated aluminum nanoparticles on the oil droplet surface was observed under applied electrical field. Experimental results showed that these nanoparticles moved and accumulated towards one side of the oil droplet under electric field. The redistribution of the nanoparticles is in qualitative agreement with the redistribution model of the mobile surface charges developed in this work

Redistribution of charged aluminum nanoparticles on oil droplets in water in response to applied electrical field

The final publication is available at Springer via http://dx.doi.org/ 10.1007/s11051-016-3390-5.Janus droplets with two opposite faces of different physical or chemical properties have great potentials in many fields. This paper reports a new method for making Janus droplets by covering one side of the droplet with charged nanoparticles in an externally applied DC electric field. In this paper, aluminum oxide nanoparticles on micro-sized and macro-sized oil droplets were studied. In order to control the surface area covered by the nanoparticles on the oil droplets, the effects of the concentration of nanoparticle suspension, the droplet size as well as the strength of electric field on the final accumulation area of the nanoparticles are studied

Algorithms to Detect and Rectify Multiplicative and Ordinal Inconsistencies of Fuzzy Preference Relations

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Consistency, multiplicative and ordinal, of fuzzy preference relations (FPRs) is investigated. The geometric consistency index (GCI) approximated thresholds are extended to measure the degree of consistency for an FPR. For inconsistent FPRs, two algorithms are devised (1) to find the multiplicative inconsistent elements, and (2) to detect the ordinal inconsistent elements. An integrated algorithm is proposed to improve simultaneously the ordinal and multiplicative consistencies. Some examples, comparative analysis, and simulation experiments are provided to demonstrate the effectiveness of the proposed methods

Single-spin scanning magnetic microscopy with radial basis function reconstruction algorithm

Exotic magnetic structures, such as magnetic skyrmions and domain walls, are becoming more important in nitrogen-vacancy center scanning magnetometry. However, a systematic imaging approach to mapping stray fields with fluctuation of several milliteslas generated by such structures is not yet available. Here we present a scheme to image a millitesla magnetic field by tracking the magnetic resonance frequency, which can record multiple contour lines for a magnetic field. The radial basis function algorithm is employed to reconstruct the magnetic field from the contour lines. Simulations with shot noise quantitatively confirm the high quality of the reconstruction algorithm. The method was validated by imaging the stray field of a frustrated magnet. Our scheme had a maximum detectable magnetic field gradient of 0.86 mT per pixel, which enables the efficient imaging of millitesla magnetic fields.Comment: 5 pages, 3 figure

Focusing particles by induced charge electrokinetic flow in a microchannel

This is the peer reviewed version of the following article: Song, Y., Wang, C., Li, M., Pan, X. and Li, D. (2016), Focusing particles by induced charge electrokinetic flow in a microchannel. ELECTROPHORESIS, 37: 666–675. doi:10.1002/elps.201500361, which has been published in final form at http://dx.doi.org/10.1002/elps.201500361. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.A novel method of sheathless particle focusing by induced charge electrokinetic flow in a microchannel is presented in this paper. By placing a pair of metal plates on the opposite walls of the channel and applying an electrical field, particle focusing is achieved due to the two pairs of vortex that constrain the flow of the particle solution. As an example, the trajectories of particles under different electrical fields with only one metal plate on one side channel wall were numerically simulated and experimentally validated. Other flow focusing effects, such as the focused width ratio (focused width/channel width) and length ratio (focused length/half-length of metal plate) of the sample solution, were also numerically studied. The results show that the particle firstly passes through the gaps between the upstream vortices and the channel walls. Afterwards, the particle is focused to pass through the gap between the two downstream vortices that determine the focused particle position. Numerical simulations show that the focused particle stream becomes thin with the increases in the applied electrical field and the length of the metal plates. As regards to the focused length ratio of the focused stream, however, it slightly increases with the increase in the applied electrical field and almost keeps constant with the increase in the length of the metal plate. The size of the focused sample solution, therefore, can be easily adjusted by controlling the applied electrical field and the sizes of the metal plates