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Lead dissolved in water must be removed in order not to cause diseases, especially from high pH aqueous solution. Various oxides having high specific surface area are often applied to remove lead in water media. To improve removal ability for lead species, it is necessary to understand the adsorbed structure of lead species on oxides. At first, the adsorption behavior of lead from high pH solution in the presence of Ca2+ and Na+ was compared. Lead and calcium species were adsorbed up to the monolayer, and the adsorption isotherm was analyzed as Langmuir-type adsorption. In the presence of Ca2+, the amount of removed lead was reduced. To clarify this influence of Ca2+, X-ray absorption spectroscopy was adopted. It was for the first time revealed that lead species at pH > 12 and pH < 10.5 differed, and that lead species adsorbed on various oxides had a similar structure.

The performance of four polymorphs of manganese (Mn) dioxides as the catalyst for the oxygen evolution reaction (OER) in proton exchange membrane (PEM) electrolysers was examined. The comparison of the activity between Mn oxides/carbon (Mn/C), iridium oxide/carbon (Ir/C) and platinum/carbon (Pt/C) under the same condition in PEM electrolysers showed that the γ-MnO 2 /C exhibited a voltage efficiency for water electrolysis comparable to the case with Pt/C, while lower than the case with the benchmark Ir/C OER catalyst. The rapid decrease in the voltage efficiency was observed for a PEM electrolyser with the Mn/C, as indicated by the voltage shift from 1.7 to 1.9 V under the galvanostatic condition. The rapid deactivation was also observed when Pt/C was used, indicating that the instability of PEM electrolysis with Mn/C is probably due to the oxidative decomposition of carbon supports. The OER activity of the four types of Mn oxides was also evaluated at acidic pH in a three-electrode system. It was found that the OER activity trends of the Mn oxides evaluated in an acidic aqueous electrolyte were distinct from those in PEM electrolysers, demonstrating the importance of the evaluation of OER catalysts in a real device condition for future development of noble-metal-free PEM electrolysers.

The study aims to construct barrier free systems for pedestrian ITS. The social experiment of these systems was took place at underground malls of Osaka station area. Needs and necessary condition of non-disabled, wheelchair users, visually disabled and hearing disabled for using pedestrian ITS were surveyed. Finally, development framework of pedestrian ITS was discussed from point of barrier free.

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プロピレンカーボネートなどの高講電率溶媒と 1,2-ジメトキシエタンなどの低粘度エーテルを混合した溶媒に電解質として LiPF6 を溶解した溶液の基礎物性と, その中でのリチウムニ次電池負極の充放電特性を研究した。電解液の粘虜や電気伝導度などの溶媒組成依存性や NMR スペクトルから電解液のイオン構造を誰定し, リチウム負極の充放電効率との関係を調べた。混合溶媒系ではドナー性の高い溶媒が Li+イオンに優先的に配位することが示唆され, その溶媒の電気化学的安定性ならびにリチウムとの反応性が充放電特性に大きな影響を与えることがわかった。すなわち, 高誘電率溶媒として, エーテルよりもドナー性が低いプロピレンカーボネートやスルホランを含む系では, 充放電効率は溶媒組成にはあまり依存しないが, 溶媒のドナー性が高く, リチウムとの反応性も比較的高いジメチルスルホキシドや3-メチル-1,3-オキサゾリジン-2-オンなどを含む系では充放電効率は溶媒組成によってかなり変化した。