Effects of charge density on water splitting at cation-exchange membrane surface in the over-limiting current region

To determine the correlation between surface properties and concentration polarization (CP) behaviors, cation exchange membranes with varying fixed charge densities were prepared and characterized by using several electrochemical analyses such as chronopotentiometry, zeta potential, and current-voltage measurements. Results showed that CP behavior depended mainly on surface charge density. With higher surface charge density, stronger electroconvection was observed, suggesting that an increase in the surface charge density increased the concentration of the counter ions at the membrane surface. As such, the electric field around the membrane surface was strengthened at a current over the limiting current density. Water splitting was also proportional to the surface charge density. This result was consistent with the classical electric field-enhanced water splitting theory, indicating that water splitting increased due to increases in the electric field and prepolarization of water molecules at the membrane-solution interface of the cation-exchange membrane. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.     

Latent heat of Korean ginseng

The latent heats of Korean ginsengs were analyzed using the data of equilibrium moisture contents. The latent heat of ginseng with pre-processing, or boiling, was larger than that of ginseng without pre-processing. The latent heat of ginseng in desorption showed a higher value than that in adsorption. The models of latent heats for white ginseng and taegeuk ginseng in desorption and taegeuk ginseng in adsorption were developed.     

A New Class of Hybrid Particle Swarm Optimization Algorithm

A new class of hybrid particle swarm optimization （PSO） algorithm is developed for solving the premature convergence caused by some particles in standard PSO fall into stagnation. In this algorithm, the linearly decreasing inertia weight technique （LDIW） and the mutative scale chaos optimization algorithm （MSCOA） are combined with standard PSO, which are used to balance the global and local exploration abilities and enhance the local searching abilities, respectively. In order to evaluate the performance of the new method, three benchmark functions are used. The simulation results confirm the proposed algorithm can greatly enhance the searching ability and effectively improve the premature convergence.     

Evaluation of electrical and optical properties of indium tin oxide thin film using chemical mechanical polishing technique

In this study, the optimum process parameters and the influences of their process parameters were investigated for indium tin oxide-chemical mechanical polishing (ITO-CMP) with the sufficient removal rate and the good planarity. And then, the optical property such as transmittance and absorption efficiency, and the electrical characteristics such as sheet resistance, carrier density and Hall mobility were discussed in order to evaluate the possibility of CMP application for the organic light emitting display (OLED) device using an ITO film. Light transmission efficiency and current-voltage characteristics of ITO thin film were improved after CMP process using optimized process parameters compared to that of as-deposited thin film before CMP process.     

Progress towards fully spray-coated semitransparent inverted organic solar cells with a silver nanowire electrode

We demonstrated a fully spray-coated semitransparent organic solar cell, from the lowermost organic layer to the uppermost top electrode. The fabricated devices based on a poly (3-hexylthiophene):[6,6]-phenyl-C61 butyric acid methyl ester (P3HT:PCBM) are semitransparent (∼70% transparency at long wavelength beyond 650 nm), fully spray-coated from organic layer to top electrode, highly efficient (∼80% of that of a device with a conventional metal electrode).     

Concrete-filled double skin steel tubular (CFDST) columns subjected to long-term sustained loading

This paper carried out a series of tests on concrete-filled double skin steel tubes (CFDST) columns under long-term sustained loading condition. The test process included two stages, i.e. long-term service test and ultimate strength test. Numerical models on analysis of the CFDST column under long-term sustained loading were presented. A comparison of results calculated using these models showed generally good agreement with the test results. Additionally, a detailed analysis was performed to analyse the long-term behaviour of CFDST columns. Finally, simplified formula for calculating the ultimate strength of CFDST columns subjected to long-term sustained loading was proposed.     

Collaborative Interaction for Videos on Mobile Devices Based on Sketch Gestures

With the rapid progress of the network and mobile techniques, mobile devices such as mobile phones and portable devices, have become one of the most important parts in common life.Efficient techniques for watching, navigating and sharing videos on mobile devices collaboratively are appealing in mobile environment.In this paper, we propose a novel approach supporting efficiently collaborative operations on videos with sketch gestures.Furthermore, effective collaborative annotation and navigation operations are given to interact with videos on mobile devices for facilitating users’ communication based on mobile devices’ characteristics.Gesture operation and collaborative interaction architecture are given and improved during the interactive process.Finally, a user study is conducted showing that the effectivity and collaborative accessibility of video exploration is improved.