Solid–liquid interface temperature measurement of evaporating droplet using thermoresponsive polymer aqueous solution

The present study aims to measure the solid–liquid interface temperature of an evaporating droplet on a heated surface using a thermoresponsive polymer. Poly(N-isopropylacrylamide) (pNIPAM) was used owing to its sensitive optical and mechanical properties to the temperature. We also measured the refractive index variation of the pNIPAM solution by using the surface plasmon resonance imaging (SPRi). In particular, the present study proposed a new method to measure the solid–liquid interface temperature using the correlation among reflectance, refractive index, and temperature. It was found that the reflectance of a pNIPAM solution decreased after the droplet deposition. The solid–liquid interface temperature, estimated from the reflectance, showed a lower value at the center of the droplet, and it gradually increased along the radial direction. The lowest temperature at the contact line region is present because of the maximum evaporative cooling. Moreover, the solid–liquid interface temperature deviation increased with the surface temperature, which means solid–liquid interface temperature should be considered at high temperature to predict the evaporation flux of the droplet accurately

Nb-doped TiO2 air-electrode for advanced Li-air batteries

As new substrate materials to replace a conventional carbon substrate, TiO2 and Nb-doped TiO2 air-electrodes for Li-air batteries were investigated. Through a simple two-step process, we successfully synthesized anatase Nb-doped TiO2 nanoparticles and demonstrated the potential applicability of TiO2-based materials for use in Li-air battery electrode. An air-electrode with Nb-doped TiO2 nanoparticles could deliver a higher discharge capacity than a bare TiO2 electrode due to the enhanced conductivity, which implies the importance of facile electron transport during the discharge process. © 2014 The Ceramic Society of Japan and the Korean Ceramic Society.

Fatigue Prediction of the Discharge Pipe in Reciprocating Compressor

In this paper, a fatigue prediction of the line discharge tube for reciprocating compressor being installed in a refrigerator was studied. The tube usually gets plenty of the repeated loads caused by the start and stop motion of a reciprocating compressor. There are two representative methods to predict the fatigue stress. At first the stress-life can be applied to the problem which takes a lot of repeated stress within the elastic strain range. Second is the strain-life method which can be used when it comes to the problem of a small repeated stress in the plastic strain range. This paper presents the stress-life method how the design parameters of a discharge pipe relate to the fatigue prediction and analyzes the co-relation between them