Osaka Prefecture University College of Technology

It is expected that a popularization of Polymer Electrolyte Fuel Cell (PEFC) as clean energy contributes to the global warming prevention. However, its manufacturing cost is so high that the reduction in the production cost is an exigence for further spread. Because the cost of platinum catalyst in the catalyst layer of the membrane electrode assembly (MEA) accounts about 46% of the total manufacturing cost, the reduction of the usage of platinum is a shortcut of the cost reduction. Generally, because a catalyst layer (CL) of MEA is manufactured by a doctor blade method, this method has some problems such as a bad dispersibility of Pt catalyst in CL and a difficult thickness control. Therefore, our laboratory has proposed applying an inkjet coating printing to the CL manufacturing process to solve these problems. Because the CL applied by an inkjet coating printing is extremely thin, a multilayer applying is necessary to obtain enough thickness of CL. However, the previous study confirmed that the cell performance of CL composed of a multilayer was lower than that of single layer. In order to investigate the cause of the performance deterioration, we aimed to elucidate the influences of the ionomer additive rate and the CL structure on the cell performance, the correlation between ionomer and Pt catalyst. As a result, the reason for the performance deterioration originated to the obstruction of the electron transport because ionomer and platinum separated in the catalyst ink droplet in the drying process of the catalyst ink, and the ionomer becomes excessive in the supernatant. Because an electron and a proton does not reach to the reaction field that is the three phase interface by this separation, the cell performance was deteriorated by the increase of the resistance and activation polarizations. However, because these polarizations are minimized when the I/C ratio is 2/3, this I/C ratio is an optimum value for the ionomer and platinum to disperse uniformly. Therefore, the gradation CL was formed by increasing I/C ratio from the GDL side to the membrane side at each applying using this separation phenomenon. As a result, the performance of the cell with the gradation CL was enhanced compared with the conventional three layer as shown in Fig.1 because the proton moves smoothly by gradually decreasing ionomer from the membrane side to the GDL side, and oxygen also diffuses to the reaction field smoothly by not being obstructed to water in the catalyst layer.The effectiveness of the inkjet printing method was able to be confirmed because various structure of the CL such as the gradation type was able to be manufactured. However, because a platinum and an ionomer separates if I/C ratio increases, it is necessary to adjust I/C ratio to 2/3 if an appropriate three-phase field side is formed. Oppositely, it is possible to make the platinum percentage vary to the thickness direction of the CL using the separation phenomenon of ionomer and platinum. Figure 1

A catalytic oxidation reaction for Acid Blue 7 dye synthesis was evaluated in water. Without lead oxide or manganese oxide derivatives as oxidants, polyoxometalate catalysts were investigated to reduce the usage of harmful heavy metal. A catalyst was prepared by mixing silicotungstic acid with copper oxide, and aqueous hydrogen peroxide (30%) was used as an oxidizing agent. This reaction proceeded to produce Acid Blue 7 from the corresponding leuco acid after 45 min at 95 °C and was viable for a 10 g-scale synthesis.

A general expression for the waveguide dispersion of a propagation mode is derived from the wave equation. Furthermore, a simple expression for the waveguide dispersion of high-order modes is derived as a function of the mode field radius by substituting an approximated function of the electrical field distribution of the mode into the general expression. The chromatic dispersions of the LP01, LP11, LP02, and LP21 modes in a four-mode fiber are estimated using the proposed expression, and their accuracies are evaluated through simulations.

Plant germ cells, such as pollen grains, can be affected by exposure to metal nanoparticles (NPs) that have diffused into the environment. The germination and tube elongation of pollen grain (Lilium longiflorum) exposed to low-solubility NPs was observed. The germination rate of pollen grain exposed to 100 mg L−1 ZnO NP dispersion decreased significantly from controls and exposure of the other NPs. On the other hand, when pollens were exposed to ionic solutions in which particles were removed from the 100 mg L−1 ZnO NP dispersion, the germination rates were equivalent to those in the control pollens. On the contrary, decrease of the germination rate compared to controls was small in the exposure to ZnCl2 solution, which contained a larger amount of water-soluble Zn2+ than ZnO NP dispersion. From these results, it was concluded that fine ZnO NP may adhere to pollens, due to the cohesive property of nanoparticles, and Zn2+ dissolved at the interface may be continuously absorbed by pollens. When pollen was exposed to ZnO NP, a spot with a high Ca2+ local concentration was observed at the tip of the pollen tube. On the contrary, simultaneous exposure to antagonistic ZnO NP and CaCl2 resulted in no decrease in the germination rate. From the above, it is considered that upon exposure to ZnO NP, cells absorb Zn2+ depending on the specific solubility of ZnO NP. Despite the low solubility of zinc oxide nanoparticle, pollen cell-attached particles inhibited germination and elongation of pollen tube by continuous Zn2+ dissolution from particles and Zn2+ absorption by the cell.

We have been developing High Functional Direct Carbon Fuel Cell (HF-DCFC) composed of molten salts gasification system and tubular molten carbonate fuel cell (T-MCFC). This paper aims to evaluate the fundamental characteristics of HF-DCFC using wood pellet and the optimum electrolyte loading ratio. As a result, we were able to confirm that the cell performance of T-MCFC depended on electrolyte loading ratio. We were able to confirm that HF-DCFC is effective enough as the distributed power source and the waste disposal equipment if wood pellet was supplied to HF-DCFC continuously, because the electric power of HF-DCFC was enhanced even if fuel gas utilization ratio increased.

There are many opportunities for visual and tactile interactions with fabrics in daily life, and there have been many studies on visual and tactile evaluation of fabrics. However, there are few studies of how the visual and tactile stimuli influence the recognition of fabrics based on short-term memory. This study examines how the memory of fabric texture is retained and is transferred between visual and haptic perceptions by intra- and inter-modal recognition experiments. Fabric was recognized under both haptic and visual single-modal conditions. Visual recognition was superior to haptic recognition under single-modal conditions, consisting of visual learning followed by a visual test and haptic learning followed by haptic test. The inter-modal experiment showed that the cross-modal recognition of fabric was possible, regardless of the order of encoding and recalling fabrics by touch or visually. Therefore, single common cross-modal representation is used when fabrics are recognized.

Vortex lattice melting in a dirty mesoscopic square superconducting plate is studied using the molecular dynamics (MD) method. We include an impurity potential in the MD method and investigate vortex number and impurity number dependences of the melting transition temperature. We find strong vortex number dependence and weak pinning potential dependence of the melting temperature.

This paper reports a new manufacturing method of a membrane electrode assembly (MEA) for polymer electrolyte fuel cell using an inkjet printer. This method enabled manufacturing a thin catalyst layer of 5μm or less, and a reduction of the amount of Pt catalyst of 36wt% from a conventional MEA made by a doctor blade method. Moreover, the performance of the cell with a MEA made by an inkjet printer was better than that of a conventional MEA regardless of the presence of humidifying the supply gas. The introduction of an inkjet printer into a catalyst layer manufacturing suggested being able to reduce a production cost of PEFC greatly.