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Kato, Masaru*; Nakahoshiba, Ryota*; Ogura, Kazuya*; Tokuda, Shoichi*; Yasuda, Satoshi; Higashi, Kotaro*; Uruga, Tomoya*; Uemura, Yohei*; Yagi, Ichizo*
ACS Applied Energy Materials (Internet), 3(7), p.6768 - 6774, 2020/07
Times Cited Count：15 Percentile：62.59(Chemistry, Physical)To understand electronic effects of nitrogen-doped and polymer-coated carbon supports on the catalytic activity of Pt-based nanostructured catalysts, we prepared Pt
Ni nanoframes (NFs) supported on polybenzimidazole (PBI)-coated and uncoated carbon nanotubes for the oxygen reduction reaction (ORR), and then compared their catalytic activities and electronic properties with those of NFs immobilized on nitrogen-doped and undoped carbon supports. Although both PBI-coating and nitrogen-doping approaches improved the catalytic activity of NFs, 
X-ray photoelectron spectroscopy and 
X-ray absorption spectroscopy revealed that nitrogen doping showed electronic effects on NFs, whereas PBI-coating showed almost no impact on the electronic state of NFs but stabilized Pt(OH)
species under electrochemical conditions. Our studies demonstrate that difference in microscopic environments of nitrogen atoms at the catalyst/support interface is highly sensitive to the electronic effects of supports on Pt-based electrocatalysts.
Sakamoto, Tetsuo*; Morita, Masato*; Kanenari, Keita*; Tomita, Hideki*; Sonnenschein, V.*; Saito, Kosuke*; Ohashi, Masaya*; Kato, Kotaro*; Iguchi, Tetsuo*; Kawai, Toshihide*; et al.
Analytical Sciences, 34(11), p.1265 - 1270, 2018/11
Times Cited Count：8 Percentile：31.98(Chemistry, Analytical)
C collected by precipitation and gas-strip methods for dating groundwaterNakata, Kotaro*; Hasegawa, Takuma*; Iwatsuki, Teruki; Kato, Toshihiro
Radiocarbon, 58(3), p.491 - 503, 2016/09
Times Cited Count：5 Percentile：21.51(Geochemistry & Geophysics)Dissolved inorganic carbon (DIC) for C analysis of groundwater is usually extracted by a gas-strip or precipitation method. In this study, the certainty of the two methods for C dating were confirmed. DIC and C concentrations obtained by the gas-strip method were close to the theoretically predicted C value. Conversely, the C value obtained by the precipitation method always showed higher values than the predicted values. The difference in C value between gas-strip and precipitation methods was assumed to arise owing to contamination of modern carbon used in the precipitation method. The applicability of the precipitation method for groundwater should be considered carefully according to the DIC, C concentration of groundwater and purpose of the study being conducted.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Sn conductor and central solenoid model coils for ITERTakahashi, Yoshikazu; Ando, Toshinari; Hiyama, Tadao; Nakajima, Hideo; Kato, Takashi; Sugimoto, Makoto; Isono, Takaaki; Oshikiri, Masayuki*; Kawano, Katsumi; Koizumi, Norikiyo; et al.
Fusion Engineering and Design, 41(1-4), p.271 - 275, 1998/09
Times Cited Count：4 Percentile：38.68(Nuclear Science & Technology)no abstracts in English
Torii, Yosuke; Yamasoto, Kotaro; Kato, Takuya; Yoshitomi, Hiroshi
no journal, ,
no abstracts in English
Kato, Takuya; Torii, Yosuke; Futagawa, Kazuo; Yamasoto, Kotaro
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no abstracts in English
Nakata, Kotaro*; Hasegawa, Takuma*; Iwatsuki, Teruki; Kato, Toshihiro
no journal, ,
C concentration in dissolved inorganic carbon is available index to infer groundwater residence time. We confirmed precision and accuracy during DIC collection methods such as degassing and precipitation by using NaHCO solution and natural groundwater.
Kato, Toshihiro; Iwatsuki, Teruki; Munemoto, Takashi; Kubota, Mitsuru; Hayashida, Kazuki; Nakata, Kotaro*; Hasegawa, Takuma*
no journal, ,
no abstracts in English
Kato, Toshihiro; Iwatsuki, Teruki; Nakata, Kotaro*; Hasegawa, Takuma*
no journal, ,
no abstracts in English
Iwatsuki, Teruki; Kato, Toshihiro; Nakata, Kotaro*; Hasegawa, Takuma*
no journal, ,
Water chemistry, isotopes and chlorofluorocarbons in groundwater down to a depth of 500 m were monitored in the Mizunami Underground Research Laboratory (MIU), Japan. The monitoring of water chemistry for more than 10 years shows the increase of shallow water infiltration in UHFD at depths between 200 - 400 m. Based on 3H and CFCs concentrations the mixing proportion of shallow groundwater was estimated up to about 50 %. On the other hand groundwater in LSFD at the depth of 500 m was identified relatively isolated condition from the hydraulic disturbance by the facility construction. The residence time of the isolated groundwater was estimated 18 - 25 ka by C.
Hasegawa, Takuma*; Nakata, Kotaro*; Tomioka, Yuichi*; Ota, Tomoko*; Hama, Katsuhiro; Iwatsuki, Teruki; Kato, Toshihiro*; Hayashida, Kazuki
no journal, ,
Groundwater dating using C, 
He, noble gas method was conducted in Mizunami Underground Research laboratory. The availability of degassing method for , flux estimation method for He were examined. It was identified that the groundwater have been derived in glacial age. The integration of distinct dating method is available to estimate precise age of groundwater.
Hasegawa, Takuma*; Nakata, Kotaro*; Tomioka, Yuichi*; Ota, Tomoko*; Hama, Katsuhiro; Iwatsuki, Teruki; Kato, Toshihiro*; Hayashida, Kazuki
no journal, ,
no abstracts in English
Tomita, Hideki*; Saito, Kosuke*; Ohashi, Masaya*; Sonnenschein, V.*; Kato, Kotaro*; Suzuki, So*; Iguchi, Tetsuo*; Morita, Masato*; Sakamoto, Tetsuo*; Kanenari, Keita*; et al.
no journal, ,
no abstracts in English
Hasegawa, Takuma*; Nakata, Kotaro*; Tomioka, Yuichi*; Ota, Tomoko*; Hama, Katsuhiro; Iwatsuki, Teruki; Kato, Toshihiro*; Hayashida, Kazuki
no journal, ,
Groundwater dating was conducted to Mizunami Underground Research Laboratory (MIU). C age and He age were estimated about 20,000 years around MIU. The estimation of noble gas temperature is also conducted. The estimated recharge temperature is around 6
C. This temperature is about 9C cooler than present annual average temperature, which agree with estimation of modern analog method conducted near MIU.
Kato, Saori; Kasugai, Yoshimi; Saito, Fumihiro; Ito, Takashi; Tanaka, Takeshi*; Sugawara, Masakatsu*; Numajiri, Masaharu*; Bessho, Kotaro*; Nakane, Yoshihiro; Miyamoto, Yukihiro
no journal, ,
Three kinds of video materials on the radioactive material leak accident which happened in J-PARC on May 23, 2013 have been produced. These have been screened on the "J-PARC Safety Day" to encourage the J-PARC staff members to keep the memory, to pass on the lessons learned to the next generation, and to use them for future safety.
