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Niwa, Hideharu*; Saito, Makoto*; Kobayashi, Masaki*; Harada, Yoshihisa*; Oshima, Masaharu*; Moriya, Shogo*; Matsubayashi, Katsuyuki*; Nabae, Yuta*; Kuroki, Shigeki*; Ikeda, Takashi; et al.
Journal of Power Sources, 223, p.30 - 35, 2013/02
Times Cited Count：18 Percentile：47.91(Chemistry, Physical)To design non-platinum, inexpensive, but high performance carbon-based cathode catalysts for polymer electrolyte fuel cells, it is important to elucidate the active site for oxygen reduction reaction (ORR). However, it is difficult to directly identify the active site by applying conventional structural or electronic probes to such complex systems. Here, we used C 1
X-ray absorption spectroscopy (XAS) to observe electronic structure of carbon in iron phthalocyanine-based catalysts, and found a signature of edge exposure below the 
edge, whose intensity is well correlated with the ORR activity. These results demonstrate that C 1 XAS can be used to characterize the ORR activity of carbon-based cathode catalysts in terms of the edge exposure.
Kiuchi, Hisao*; Niwa, Hideharu*; Kobayashi, Masaki*; Harada, Yoshihisa*; Oshima, Masaharu*; Chokai, Masayuki*; Nabae, Yuta*; Kuroki, Shigeki*; Kakimoto, Masaaki*; Ikeda, Takashi; et al.
Electrochimica Acta, 82(1), p.291 - 295, 2012/10
Times Cited Count：14 Percentile：32.10(Electrochemistry)We study the characteristics of oxygen adsorption on metal-free carbon-based cathode catalysts derived from nitrogen-containing polyamide (PA) and nitrogen-free phenolic resin (PhRs). Electrochemical analysis and Raman spectroscopy showed higher 2-electron oxygen reduction reaction (ORR) activity and more defect sites in PA than PhRs. The increase in the amount of adsorbed oxygen in PA was also identified by oxygen adsorption isotherms. 
X-ray photoelectron spectroscopy reveals that graphite-like nitrogen contributes to oxygen adsorption and C=O components are dominant in PA. These experimental results indicate that the adsorbed C=O components near the graphite-like nitrogen can be assigned as active sites for 2-electron ORR.
Sugiura, Hirokazu*; Kondo, Hiroo*; Kanemura, Takuji*; Niwa, Yuta*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; et al.
Fusion Engineering and Design, 84(7-11), p.1803 - 1807, 2009/06
Times Cited Count：3 Percentile：23.38(Nuclear Science & Technology)To develop a diagnostics system in view of its application on International Fusion Materials Irradiation Facility (IFMIF) liquid lithium (Li) target, velocity measurements on a liquid Li flow were performed in a Li circulation loop at Osaka University with a test section having a contraction nozzle 1/2.5 scale of IFMIF and producing a flat plane jet of 70 mm width and 10 mm thickness. Based on the Particle Image Velocimetry (PIV) technique, a local Li flow velocity distribution was measured by tracking brightness intensity patterns of surface waves generated on the flow. Measured surface velocity showed good agreement with a surface velocity obtained in previous water experiments, and had an insignificant effect at an area corresponding to a deuteron beam irradiation area on the IFMIF target.
Mukai, Kazuo; Niwa, Hajime; Sagayama, Yutaka; Ono, Katsumi*
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no abstracts in English
Kanemura, Takuji*; Kondo, Hiroo*; Ko, Kazuhira*; Yoshida, Yusuke*; Niwa, Yuta*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; et al.
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no abstracts in English
Sugiura, Hirokazu*; Kondo, Hiroo*; Kanemura, Takuji*; Niwa, Yuta*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Horiike, Hiroshi*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; et al.
no journal, ,
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Hase, Yoshihiro; Sakaniwa, Hideyasu; Ono, Yutaka
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Wakai, Eiichi; Kondo, Hiroo; Kanemura, Takuji; Hirakawa, Yasushi; Furukawa, Tomohiro; Kikuchi, Takayuki; Ito, Yuzuru*; Hoashi, Eiji*; Yoshihashi, Sachiko*; Horiike, Hiroshi*; et al.
no journal, ,
no abstracts in English
Hase, Yoshihiro; Sakaniwa, Hideyasu; Ono, Yutaka
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no abstracts in English
Ishihara, Takanori; Hosoya, Takashi*; Matsumoto, Nayuta*; Nakase, Chiharu*; Shimada, Koji; Niwa, Masakazu
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As a general method for describing cracks in bedrock outcrops, researchers set a survey line on the outcrops and directly measure cracks on the survey line. However, this method requires longer observation time and/or much more researchers for larger outcrop size. Additionally, physical damage to researchers could be considerable in cold climates. Difficulties in access to the outcrops, such as river depth, river width, and vegetation, could also be concerned. In recent years, unmanned aerial vehicles (UAVs) have been used to shorten on-site work time and replace work in difficult-to-reach places. UAVs are used in a wide variety of fields, including aerial photography, air transportation, agriculture, and surveying. In the field of surveying, the Geospatial Information Authority of Japan has prepared a surveying manual. A case study on the topographic interpretation using a UAV (Sugawara et al., 2021). In this study, we tried description of cracks in bedrock outcrops using a UAV. The observations from up above or oblique above can enable to obtain three-dimensional information including direction and length of cracks. On the other hand, it is necessary to understand the accuracy of crack data specifically when crack size is small. We created three-dimensional point cloud data by SfM (Structure from Motion) technology from aerial images taken using a UAV, and measured strike and dip from the point cloud data using free software. In this presentation, we will introduce the method to read strike and dip from the point cloud data and show the result of comparison between the values from the aerial images and those measured in the field. This study was funded by the Ministry of Economy, Trade and Industry, Japan as part of its R&D supporting programs "Establishment of Technology for Comprehensive Evaluation of the Long-term Geosphere Stability on Geological Disposal Project of Radioactive Waste (Fiscal Years 2023) (Grant number: JPJ007597)".
