Refine your search:     
Report No.
 - 
Search Results: Records 1-19 displayed on this page of 19
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Approach to elucidate corrosion mechanism on metal surface using first-principles calculations

Igarashi, Takahiro; Otani, Kyohei; Komatsu, Atsushi; Kato, Chiaki; Sakairi, Masatoshi*

Bosei Kanri, 66(4), p.141 - 145, 2022/04

Metal corrosion is a material deterioration phenomenon based on electrochemical reactions on an atomic scale. In this paper, various methods for acquiring physical properties on metal surfaces using first-principles calculations were described. As examples of applying first-principles calculation to metal corrosion, the effect of hydrogen adsorption on the metal surface on the potential change and the effect of cation atoms in the aqueous solution on the corrosion resistance of the metal were reported.

Journal Articles

Bayesian sparse modeling of extended X-ray absorption fine structure to determine interstitial oxygen positions in yttrium oxyhydride epitaxial thin film

Kumazoe, Hiroyuki*; Igarashi, Yasuhiko*; Iesari, F.*; Shimizu, Ryota*; Komatsu, Yuya*; Hitosugi, Taro*; Matsumura, Daiju; Saito, Hiroyuki*; Iwamitsu, Kazunori*; Okajima, Toshihiko*; et al.

AIP Advances (Internet), 11(12), p.125013_1 - 125013_5, 2021/12

 Times Cited Count:1 Percentile:8.23(Nanoscience & Nanotechnology)

Journal Articles

Modeling and simulation of atmospheric corrosion of carbon steel considering environmental factor

Igarashi, Takahiro; Komatsu, Atsushi; Kato, Chiaki; Sakairi, Masatoshi*

Tetsu To Hagane, 107(12), p.998 - 1003, 2021/12

AA2020-0549.pdf:1.53MB

 Times Cited Count:0 Percentile:0(Metallurgy & Metallurgical Engineering)

In order to clarify the effect of environmental factors on the amount of atmospheric corrosion of steel, novel model for predicting the reduction of atmospheric corrosion considering relative humidity and rain falls was developed. We conducted a one-year calculation simulation of atmospheric corrosion in Miyakojima City, Choshi City, and Tsukuba City using the developed model. Corrosion weight loss by the simulation could reproduce the measured value well. Corrosion weight loss at each point was greatly affected by the amount of flying sea salt, relative humidity, and rain falls.

Journal Articles

Development of atmospheric corrosion model considering meteorological data and airborne sea salt

Igarashi, Takahiro; Komatsu, Atsushi; Kato, Chiaki; Sakairi, Masatoshi*

Bosei Kanri, 65(10), p.365 - 370, 2021/10

We have developed a new atmospheric simulation model considering important environmental factors such as airborne sea salt, temperature, relative humidity, and rainfall. The developed model was verified by comparing predicted values by the simulation and measured data for the weight loss by atmospheric corrosion. In addition, atmospheric corrosion simulations under open and sheltered exposure condition were conducted, and it was confirmed that the air corrosion weight loss was strongly suppressed by the surface cleaning effect due to rainfall.

Journal Articles

Hydrogen absorption mechanism into iron in aqueous solution including metal cations by laser ablation tests and first-principles calculations

Igarashi, Takahiro; Otani, Kyohei; Kato, Chiaki; Sakairi, Masatoshi*; Togashi, Yusuke*; Baba, Kazuhiko*; Takagi, Shusaku*

ISIJ International, 61(4), p.1085 - 1090, 2021/04

 Times Cited Count:0 Percentile:8.46(Metallurgy & Metallurgical Engineering)

In order to clarify the effect of metal cations (Zn$$^{2+}$$, Mg$$^{2+}$$, Na$$^{+}$$) in aqueous solution on hydrogen permeation into iron, the amount of hydrogen permeation from iron surface was measured by electrochemical tests with a laser ablation. Moreover, in order to obtain the basic mechanism of hydrogen permeation with metal cation, first-principles calculations were used to acquire the adsorption potential of the metal cation and the electronic state around iron surface. By Zn$$^{2+}$$ in solution, anodic reaction on ablated surface by laser irradiation was suppressed. Also, by quantum analysis Zn atoms were chemically bonded stronger than Na and Mg atoms to iron surface. It was suggested that the dissolution reaction of iron was suppressed by the formation of the Zn layer, and that lead suppression of hydrogen permeation into iron.

Journal Articles

Validation of analysis models on relocation behavior of molten core materials in sodium-cooled fast reactors based on the melt discharge experiment

Igarashi, Kai*; Onuki, Ryoji*; Sakai, Takaaki*; Kato, Shinya; Matsuba, Kenichi; Kamiyama, Kenji

Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 6 Pages, 2020/08

Journal Articles

Analysis of two forms of radioactive particles emitted during the early stages of the Fukushima Dai-ichi Nuclear Power Station accident

Satou, Yukihiko; Sueki, Keisuke*; Sasa, Kimikazu*; Yoshikawa, Hideki; Nakama, Shigeo; Minowa, Haruka*; Abe, Yoshinari*; Nakai, Izumi*; Ono, Takahiro*; Adachi, Koji*; et al.

Geochemical Journal, 52(2), p.137 - 143, 2018/00

 Times Cited Count:65 Percentile:97.21(Geochemistry & Geophysics)

Journal Articles

Investigation of the chemical characteristics of individual radioactive microparticles emitted from reactor 1 by the Fukushima Daiichi Nuclear Power Plant accident by using multiple synchrotron radiation X-ray analyses

Ono, Takahiro*; Iizawa, Yushin*; Abe, Yoshinari*; Nakai, Izumi*; Terada, Yasuko*; Satou, Yukihiko; Sueki, Keisuke*; Adachi, Koji*; Igarashi, Yasuhito*

Bunseki Kagaku, 66(4), p.251 - 261, 2017/04

 Times Cited Count:32 Percentile:79.36(Chemistry, Analytical)

no abstracts in English

Journal Articles

On-site background measurements for the J-PARC E56 experiment; A Search for the sterile neutrino at J-PARC MLF

Ajimura, Shuhei*; Bezerra, T. J. C.*; Chauveau, E.*; Enomoto, T.*; Furuta, Hisataka*; Harada, Masahide; Hasegawa, Shoichi; Hiraiwa, T.*; Igarashi, Yoichi*; Iwai, Eito*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2015(6), p.063C01_1 - 063C01_19, 2015/06

 Times Cited Count:6 Percentile:45.45(Physics, Multidisciplinary)

The J-PARC E56 experiment aims to search for sterile neutrinos at the J-PARC Materials and Life Science Experimental Facility (MLF). In order to examine the feasibility of the experiment, we measured the background rates of different detector candidate sites, which are located at the third floor of the MLF, using a detector consisting of plastic scintillators with a fiducial mass of 500 kg. The gammas and neutrons induced by the beam as well as the backgrounds from the cosmic rays were measured, and the results are described in this article.

Journal Articles

Highly efficient homogeneous liquid-liquid extraction of lanthanoid ions in a strong acidic solution

Fuchimukai, Junichi*; Yamaguchi, Hitoshi*; Meguro, Yoshihiro; Kubota, Toshio*; Igarashi, Shukuro*

Solvent Extraction Research and Development, Japan, 13, p.139 - 146, 2006/00

no abstracts in English

Oral presentation

Determination of plutonium in insoluble residue at reprocessing facility

Igarashi, Kazuto*; Nemoto, Hirokazu*; Okano, Masanori; Yamada, Keiji; Sakai, Toshio

no journal, , 

no abstracts in English

Oral presentation

Determination of impurity in dissolved solution of spent nuclear fuel by ICP-AES

Okano, Masanori; Igarashi, Kazuto*; Nemoto, Hirokazu*; Yamada, Keiji; Sakai, Toshio

no journal, , 

no abstracts in English

Oral presentation

Summary and lesson learned on nuclear disaster robots of JAEA in the accident at Fukushima Daiichi Nuclear Power Station

Okada, Takashi; Kawatsuma, Shinji; Fukushima, Mineo; Igarashi, Miyuki; Nakai, Koji; Mimura, Ryuji; Kanayama, Fumihiko

no journal, , 

Due to Tohoku Pacific Ocean earthquake and tsunami in 11 March in 2011, Tokyo Electric Power Co. Fukushima Daiichi Nuclear Power Station lost all power and has occurred accidents for failure of core cooling function. In Japan Atomic Energy Agency it was remodeled the nuclear disaster robot, was developed $$gamma$$-ray visualization equipment and has been supporting the accident recovery. This paper is described the lessons learned from the supporting with the nuclear disaster robots and the $$gamma$$-ray visualization equipment.

Oral presentation

Remote operation technology applied for the Fukushima Daiichi Nuclear Power Plant accident

Okada, Takashi; Nakai, Koji; Igarashi, Miyuki; Kawatsuma, Shinji

no journal, , 

Japan Atomic Energy Agency developed a robotic control vehicle for supporting the accident recovery in the Fukushima Daiichi Nuclear Power Station. The developed robotic control vehicle can measure radiation using a $$gamma$$ cam and a robot with a radiation sensor. A heavily shielded operation box was built for reducing the exposure of radiation.

Oral presentation

Studies on relocation behavior of molten core materials in the core disruptive accident of sodium-cooled fast reactors, 7; Validation of analysis models for the melt discharge experiments into a shallow water pool

Igarashi, Kai*; Sakai, Takaaki*; Kato, Shinya; Matsuba, Kenichi; Kamiyama, Kenji

no journal, , 

In order to clarify the accumulation behavior on the core disruptive accident in sodium cooled fast reactors, an analysis for the experiment in which the low-melting point alloy drop into a shallow water pool was conducted by using SIMMER code. In this presentation, the validation result for the analysis geometry model conducted by the comparison of the calculation result and experimental value is presented.

Oral presentation

Studies on relocation behavior of molten core materials in the core disruptive accident of sodium-cooled fast reactors, 9; Validation of analysis models for the fragmentation and cooling behavior of melt impinging onto a horizontal structure in sodium

Igarashi, Kai*; Sakai, Takaaki*; Kato, Shinya; Matsuba, Kenichi; Kamiyama, Kenji

no journal, , 

Simulation using SIMMER-III code was performed for an EAGLE-3 out-of-pile experiment whose objective was to clarify the fragmentation and cooling behavior of molten core material impinging onto a horizontal plate in sodium during core disruptive accidents of sodium-cooled fast reactors. Validation of the analytical model was confirmed by comparing analytical and experimental results.

Oral presentation

Simulation of atmospheric corrosion using mathematical model

Igarashi, Takahiro; Komatsu, Atsushi; Kato, Chiaki; Sakairi, Masatoshi*

no journal, , 

From the viewpoint of environmental and energy problems, research on atmospheric corrosion of steel materials is one of the important themes. In this study, we focused on the liquid film thickness, which is one of the environmental factors greatly related to the amount of corrosion, and constructed and simulated a corrosion prediction model using the amount of adsorbed salt and relative humidity as parameters. The developed model made it possible to express changes in corrosion rate due to changes in relative humidity day and night. In addition, there were times when the corrosion rate changed drastically during the day. Analysis of the simulation data suggested that this might be a change in the liquid film thickness due to the deliquescent of the contained salt.

Oral presentation

Analysis of cooling behavior of core materials colliding with horizontal structures of sodium-cooled fast reactors

Matsushita, Hatsuki*; Igarashi, Kai*; Isozaki, Kazuma*; Sakai, Takaaki*; Kato, Shinya; Matsuba, Kenichi; Kamiyama, Kenji

no journal, , 

no abstracts in English

Oral presentation

Modelling of atmospheric corrosion considering environment factors

Igarashi, Takahiro; Komatsu, Atsushi; Kato, Chiaki; Sakairi, Masatoshi*

no journal, , 

Large structures such as bridges and nuclear facilities in the sea shore area are exposed to a severe corrosive environment by airborne sea salt. From the viewpoint of ensuring facility safety and environmental and energy issues, it is one of the important themes to elucidate the mechanism of atmospheric corrosion of steel materials, which are the main materials of large structures. In the study, we modified existing model in which precipitation and humidity were considered as influential factors for atmospheric corrosion, and developed a novel model for predicting atmospheric corrosion loss with additional consideration of temperature. The developed model corrected the excessive prediction of corrosion amount by the existing model, and enabled more precise prediction of atmospheric corrosion weight loss.

19 (Records 1-19 displayed on this page)
  • 1