Experimental visualization of water/ice phase distribution at cold start for practical-sized polymer electrolyte fuel cells

Higuchi, Yuki*; Yoshimune, Wataru*; Kato, Satoru*; Hibi, Shogo*; Setoyama, Daigo*; Isegawa, Kazuhisa*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Harada, Masashi*; et al.

Communications Engineering (Internet), 3, p.33_1 - 33_7, 2024/02

https://doi.org/10.1038/s44172-024-00176-6

3D water management in polymer electrolyte fuel cells toward fuel cell electric vehicles

Yoshimune, Wataru*; Higuchi, Yuki*; Kato, Akihiko*; Hibi, Shogo*; Yamaguchi, Satoshi*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Shinohara, Takenao; Kato, Satoru*

ACS Energy Letters (Internet), 8(8), p.3485 - 3487, 2023/08

https://doi.org/10.1021/acsenergylett.3c01096

Thermally altered subsurface material of asteroid (162173) Ryugu

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.

Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03

https://doi.org/10.1038/s41550-020-01271-2

Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.

Progress report of Japanese simulation research projects using the high-performance computer system Helios in the International Fusion Energy Research Centre

Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.

Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03

http://www.jspf.or.jp/Journal/PDF_JSPF/jspf2016_03/jspf2016_03-157.pdf

The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.

Evaluation on materials performance of Hastelloy alloy XR for HTTR uses, 6; Tensile and creep properties of heat exchanger tube base materials and its welded-joints

Watanabe, Katsutoshi; Shindo, Masami; Nakajima, Hajime; Koikegami, Hajime*; Higuchi, Makoto*; Nakanishi, Tsuneo*; Sahira, Kensho*; Marushichi, Koki*; Takeiri, Toshiki*; Saito, Teiichiro*; et al.

JAERI-Research 97-009, 62 Pages, 1997/02

JAERI-Research-97-009.pdf:4.82MB

no abstracts in English

Development of a filler metal for Hastelloy Alloy XR welded-structures for High Temperature Engineering Test Reactor application

Watanabe, Katsutoshi; Nakajima, Hajime; Sahira, Kensho*; Marushichi, Koki*; Takeiri, Toshiki*; Saito, Teiichiro*; Takatsu, Tamao*; Nakanishi, Tsuneo*; Koikegami, Hajime*; Higuchi, Makoto*

Proc. of the 2nd JAERI Symp. on HTGR Technologies; Oct. 2123,1992,Oarai,Japan (JAERI-M 92-215), p.560 - 574, 1993/01

https://jopss.jaea.go.jp/pdfdata/JAERI-M-92-215.pdf

no abstracts in English

Development of hastelloy alloy XR filler metal lowered weld cracking susceptibility

Watanabe, Katsutoshi; Nakajima, Hajime; Sahira, Kensho*; Marushichi, Koki*; Takeiri, Toshiki*; Saito, Teiichiro*; Takatsu, Tamao*; Nakanishi, Tsuneo*; Koikegami, Hajime*; Higuchi, Makoto*

Tainetsu Kinzoku Zairyo Dai-123-Iinkai Kenkyu Hokoku, 33(2), p.227 - 242, 1992/00

no abstracts in English

Water/ice identification in a model PEFC using energy-selective high-resolution neutron imaging

Song, F.; Higuchi, Yuki*; Hibi, Shogo*; Yoshimune, Wataru*; Kato, Satoru*; Shinohara, Takenao

no journal, , 

Risk reduction methods for preventing corrosion leakage in the novel nuclear field

Hashiguchi, Ayumi*; Nishimura, Akihiko; Minehara, Eisuke*; Shobu, Takahisa; Kurita, Keisuke

no journal, , 

JAEA developed a new maintenance technique for carbon steel containers using a CW fiber laser cleaning. This technique can be upgraded by corrosion prevention, where the laser irradiation removes rust and coating. The coating to improve long-term corrosion resistance by forming micro-crystallization and oxide film on the vessel surface through rapid heating and cooling. In this report, neutron imaging using JRR-3 is presented, where fused silica barely absorbed neutrons, but some absorption was observed in borosilicate glass and plastic. Lead and iron showed similar transmission to plastic and borosilicate glass. Clear images could be obtained even after a short imaging time. Water in the container absorbed most of the neutrons, and could be photographed. The contents of the simulated waste in an iron container were also clearly visible.