MRS-J NEWS　Vol.20 No.4  November 2008

■Hello members!!

Materials Science Holds Human Life

Prof.Dr.HidetoshiSAITOH,NagaokaUniversityofTechnology

　Five people, including children, have been killed by a flash flood that struck an urban area in Kobe city in this summer. A camera recorder recorded everything happening that victims who played in the river side park suddenly disappeared into the flash flood. This accident is a kind of the urban flood disaster at the city surrounded by concrete buildings. Many presses said that urban development that increases quality of life killed five people. However, we have to know that two children survived from the flash flood with aid of development of materials science and/or industry on the other side of the disaster. They made the best use of buoyancy of a knapsack to prevent submersion in the flood. They took lessons in survival floating technique or tyakuiei in Japanese that uses buoyancy of manufactured goods at elementary school.

Fig.1 Lessons in survival floating technique, tyakuiei in Japanese

■Laboratory introduction

The Industrial Research Institute of Niigata Prefecture

Koji SHICHIKU, The Industrial Research Institute of Niigata Prefecture

　There are about 15,000 industries in Niigata Prefecture, but about 99% of them are small and medium sized enterprises (the number of employees being less than 300).
　Many of these small and medium sized enterprises do not have the financial, man-power, or technical resources to research&develop new commercial products and new industrial technologies.
　The Industrial Research Institute of Niigata Prefecture was established to help small and medium sized industries expand into new advanced fields.

図-1　県内の本研究所各機関位置 研究背景

図-2　高耐久性人工股関節の超精密加工技術に関する共同研究 開発目標

図-3　航空機用難削材の加工技術に関する共同研究 開発目標

図-4　画像処理を利用した鋳鉄品の外観検査自動化に関する共同研究

図-5　マグネシウム合金の次世代製品に関する受託研究（表面)

図-6　マグネシウム合金の次世代製品開発に関する受託研究（形状付与)

■Topics

Real Time XAFS Analysis of Automotive Exhaust Catalyst

Kazuhiko DOHMAE, Toyota Central R&D Labs.

　Chemical reactions of rhodium for reduction treatment were investigated with in situ time-resolved X-ray absorption fine structure (XAFS). Two types of XAFS techniques were applied for the experiments: energy-dispersive XAFS and usual step-scanning XAFS. The reduction rates of the rhodium supported on alumina after oxidization were measured with dispersive XAFS. The reducing condition was with 3% H2 in He at various temperatures from 100℃ to 250℃. The reduction rate of the rhodium was on a line in an Arrhenius plot. Reduction of the rhodium on the alumina in 3% H2 in He at 900℃ after high temperature oxidization at 900℃ and 1000℃ were measured with step-scan XAFS. Some portion of rhodium was hardly reduced at 900℃. The hardly reducible rhodium was considered to be reacted with the alumina support and lost catalytic activities.

図-1　Dispersive-XAFS測定法の構成

図-2　250℃で20%酸素から3%水素ガス切り替え後のRh-K吸収端XANESスペクトル変化。
各スペクトルは23,260eVにてノーマライズしてある。矢印は還元処理による変化の方向を示す

図-3　ガス切り替え後のRh-K吸収端エネルギー変化。
実線は(1)式での近似曲線、破線は酸化ロジウム、
金属ロジウムの吸収端エネルギーをそれぞれ示す

図-4　3%水素でのロジウム還元速度のアレニウス・プロット。破線は近似直線

図-5　3%水素雰囲気中900℃での還元処理後のRh-K吸収端エネルギー変化

図-6　酸化処理温度および時間と不活性化したロジウムの割合の関係

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