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Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
Kogaku Kyoiku, 69(3), p.3 - 10, 2021/05
The purpose of engineering ethics education is to understand the effects and impacts of technology on society and nature and the responsibilities that engineers have to fulfill for society. There are many cases used in the educational method so that the students can understand the problems surrounding the engineers. However, most of the cases correspond to event scenarios where engineers have failed to maintain safety. Resilience engineering was born from the criticism of safety measures for the purpose of preventing recurrence by seeking human error and organizational culture as the cause of accidents in the field of ergonomics. Its features are that people are considered as beings that realize safety in dangerous systems, and that they focus on good practices. This paper describes the improvement of engineering ethics education by utilizing resilience engineering concept.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 18(2), p.55 - 68, 2019/06
This study aims to improve the potential of an emergency response by analyzing the workload management during the accident at the Emergency Response Center (ERC) of TEPCO's Fukushima Daiichi Nuclear Power Plant. Specifically, the research focused on the response of the ERC during the time between the discontinuation of Unit 3 core water injection and its recovery. It identified the different types of workload at the ERC had and how they had been managed based on the record of a TV conference. It also deduced the casual factors of the responses, supplementing the interview record of the director of ERC at the time by applying workload management analysis. On the basis of these findings, lessons to enhance the potential of the on-site emergency response have been obtained for ERC and outside organizations.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Ningen Kogaku, 54(3), p.124 - 134, 2018/06
Fukushima Daiichi Nuclear Power Plant caused a severe accident which released a large amount of radioactivity triggered by the Great East Japan Earthquake. The existing investigation reports of the accident prepared by several institutions pay attention only to the process which caused the accident but not much to the accident mitigation or the recovery process. This study focused on Unit 3 of Fukushima Daiichi Nuclear Power Plant, including its recovery process from the accident. Based on the public data, the time sequences for the recovery process between the accident occurrence and the state of cold shutdown were classified. Then, the groups of actions were sorted out in terms of ergonomics viewpoint. The important responses in the recovery process were identified and analyzed referring to the m-SHEL model. As a result, new lessons were learned from the accident case regarding the actions required for recovering from the accident.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Ningen Kogaku, 54(1), p.1 - 13, 2018/02
The two approaches as the concepts to ensure safety of the complicated socio-technical systems have been proposed by Hollnagel. They are the safety concepts called "Safety-I" to reduce risks and "Safety-II" to expand successes. The resilience engineering is suggested as the methodology to achieve Safety-II. The study analyzes the recovery of the water injection of Unit 3 based on the resilience engineering, focusing on the fact that preventing further progress of the accident case in Fukushima Daiichi Nuclear Power Plant which has been evaluated for extracting risk factors. Based on those results, the study has clarified the method of learning to enhance safety which has a different view from existing accident investigation.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Nihon Kikai Gakkai Rombunshu (Internet), 83(856), p.17-00263_1 - 17-00263_17, 2017/12
-tetrafluoroethylene) films using different mediaNuryanthi, N.*; Yamaki, Tetsuya; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; et al.
Transactions of the Materials Research Society of Japan, 40(4), p.359 - 362, 2015/12
The ion-track grafting of a vinylbenzyl chloride (VBC) into a poly(ethylene-co-tetrafluoroethylene) (ETFE) film is necessary for preparing nanostructured hydroxide-ion-conductive electrolyte membranes. A key for success here is to obtain as high graft levels as possible (for higher conductivity) in a smaller number of tracks (for improving the other membrane properties). To this end, therefore, the effect of the medium for the VBC grafting was investigated as part of our continuing effort to optimize the experimental conditions. A 25 
m-thick ETFE film was irradiated in a vacuum chamber with 560 MeV 
Xe at different fluences, and then the grafting was performed by immersing the irradiated films in a 20vol% VBC monomer at 60
C. A medium was a mixture of water (H
O) and isopropyl alcohol (iPrOH) at different volume ratios. The degree of grafting increased as the HO content became higher, and reached a maximum in pure HO. These results can be explained by considering the well-known Trommsdorff effect, in which poor solubility of the grafted polymer in polar media leads to an increased polymerization rate probably due to a lower termination rate.
Shinohara, Yoshikuni; Kitamura, Masaharu*
JAERI-M 5664, 34 Pages, 1974/04
no abstracts in English
Shono, Akira; *; *; *; Kitamura, Masaharu*
Nihon Genshiryoku Gakkai-Shi, 27(08), 94 Pages,
None
Nuryanthi, N.*; Yamaki, Tetsuya; Koshikawa, Hiroshi; Asano, Masaharu; Sawada, Shinichi; Hasegawa, Shin; Kitamura, Akane; Maekawa, Yasunari; Katsumura, Yosuke*
no journal, ,
We prepared ion-track membranes of poly(vinylidene fluoride) by chemical etching in a conductometric cell and then investigated how the applied AC voltage affected etching characteristics using scanning electron microscopy. The high voltage application had some effect on the final pore diameter, which seems inconsistent with the findings of our previous conductometric analysis, while shortening the breakthrough time greatly.
Matsuda, Yasuhiro*; Okuyama, Katsushi*; Komatsu, Hisanori*; Oki, Saiko*; Hashimoto, Naoki*; Sano, Hidehiko*; Yamamoto, Hiroko*; Iwami, Yukiteru*; Hayashi, Mikako*; Nomachi, Masaharu*; et al.
no journal, ,
no abstracts in English
-ray-induced graftingNuryanthi, N.*; Yamaki, Tetsuya; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; et al.
no journal, ,
The ion-track grafting of a vinylbenzyl chloride (VBC) into a poly(ethylene-co-tetrafluoroethylene) (ETFE) film is necessary for preparing nanostructured hydroxide-ion conductive electrolyte membranes. A key for success here is to obtain as high graft levels as possible (for higher conductivity) in a smaller number of tracks (for improving the other membrane properties). To this end, therefore, the effect of the medium for the VBC grafting was investigated as part of our continuing effort to optimize the experimental conditions. A 25 m-thick ETFE film was irradiated in a vacuum chamber with 560 MeV Xe at different fluences, and then the grafting was performed by immersing the irradiated films in a 20vol% VBC monomer at 60C. A medium was a mixture of water (HO) and isopropyl alcohol (iPrOH) at different volume ratios. The degree of grafting increased as the HO content became higher, and reached a maximum in pure HO.
Yamaki, Tetsuya; Nuryanthi, N.*; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; Terai, Takayuki*
no journal, ,
Heavy ions at kinetic energies typically from several hundreds of MeV to a few GeV passing through a polymer substrate induce a continuous trail of excitations and ionizations called latent tracks. We used a direct ion-track grafting method for preparation of anion exchange membranes for fuel cells. The functional anion exchange groups were introduced inside the latent tracks, thereby achieving OH
-conductive channels through the thickness. These straight channels increased conductivities, while the isolated cylindrical structure of tracks restricted the water uptake.
Yamaki, Tetsuya; Nuryanthi, N.*; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Asano, Masaharu*; Maekawa, Yasunari; Suzuki, Akihiro*; Terai, Takayuki*
no journal, ,
We investigated the ion-track grafting of vinylbenzyl chloride (VBC) into a poly(ethylene-
-tetrafluoroethylene) (ETFE) film using different grafting media for applications as anion exchange membranes for fuel cells. In an attempt to increase the grafting yield, we applied a poor solvent system as the grafting medium, 
, a mixture of water and isopropyl alcohol (HO-
PrOH mixture). The optimum HO-PrOH composition was identified by the kinetic parameters including the initial polymerization rate (r
), the radical recombination rate () and the grafting efficiency (r/). These parameters changed depending on the VBC-grafting/chain-transfer reaction competition for the radicals on ETFE and the Trommsdorff effect; the swelling of the grafting substrate gave an additional effect.
Nuryanthi, N.*; Yamaki, Tetsuya; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Asano, Masaharu*; Maekawa, Yasunari; Suzuki, Akihiro*; Terai, Takayuki*
no journal, ,
We have used the ion-track grafting technique for developing an anion exchange membrane for fuel cell applications. In order to obtain the membrane, a vinyl benzyl chloride (VBC) was grafted into an ion-irradiated poly(ethylene--tetrafluoroethylene) film. This study deals with investigation of the radicals remaining in each track and the VBC grafting with a variety of ion beams from the TIARA cyclotron. The accelerated ions with different masses and energies enabled us to clarify the effect of the LET and radial dose distribution in the track on the VBC grafting. Such extensive research will bring us interesting knowledge relating the track structures to the resulting membrane properties.
Yamaki, Tetsuya; Nuryanthi, N.*; Koshikawa, Hiroshi; Asano, Masaharu*; Sawada, Shinichi; Kitamura, Akane; Maekawa, Yasunari; Kay-Obbe, V.*; Severin, D.*; Seidl, T.*; et al.
no journal, ,
Practically, polyvinylidene fluoride (PVDF) has been said to be the only fluoropolymer in which ion tracks can be developed by chemical etching. We thus investigated the possibility of varying the beam parameters and applying the effect of a pre-etching treatment for PVDF ion-track membranes with the goal of achieving enhanced track etching for effective control of the pore size and shape. Our activities also cover all types of fluoropolymers including PVDF. Compared to PVDF, poly(ethylene--tetrafluoroethylene) and a series of perfluoropolymers are known to be very stable in highly-concentrated acid or alkaline solutions or at higher temperatures. Although this property might make their ion-track etching very challenging, the ongoing research is expected to allow one to accumulate know-how on methods of chemical etching, which can be generalized for the chemical structures. These will give feedback to a guiding principle for effective ion-track etching in fluoropolymers.
Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
no journal, ,
no abstracts in English
Yoshizawa, Atsufumi*; Matsumoto, Atsushi*; Oba, Kyoko; Kitamura, Masaharu*
no journal, ,
no abstracts in English
Kitamura, Masaharu*; Oba, Kyoko; Yoshizawa, Atsufumi*
no journal, ,
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
no journal, ,
Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
no journal, ,
no abstracts in English
