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Hidaka, Akihide
Journal of Radioanalytical and Nuclear Chemistry, 332, p.1607 - 1623, 2023/03
Times Cited Count：0 Percentile：0.01(Chemistry, Analytical)no abstracts in English
Hidaka, Akihide
Nuclear Technology, 208(2), p.318 - 334, 2022/02
Times Cited Count：6 Percentile：69.63(Nuclear Science & Technology)The author previously proposed that the Cs bearing microparticle (Type A) may have been formed by melting and atomization of glass fibers (GF) of the HEPA filter in the SGTS due to flame and blast during the hydrogen explosion in Unit 3. If this hypothesis is correct, the Type A could contain or accompany carbon (C), that ignites spontaneously above 623 K, because of the limited time to be heated up, inclusion of C in the binder applied on the GF surface and closely located charcoal filter. As the previous studies did not focus on C, the present analyses were performed with EPMA whether the Type A contains C. The results showed that the Type A contained C originating from the binder, and non-spherical particles accompanied by the Type A and the film surrounding the Type A contained more C, which is thought to originate from the charcoal filter. These results cannot be explained by the other mechanisms proposed so far, and can be explained consistently by the author proposed hypothesis.
Hidaka, Akihide
Journal of Nuclear Science and Technology, 56(9-10), p.831 - 841, 2019/09
Times Cited Count：12 Percentile：79.16(Nuclear Science & Technology)The insoluble Cs particles (Type A) were firstly observed in Tsukuba-city on the morning of March 15. The particles have been considered to be generated in RPV of Unit 2 by evaporation/condensation based on the measured 
Cs/
Cs ratio and the core temperatures of each unit. However, the Type A particles with smaller diameter than the Type B particles of Unit 1 origin, are covered by almost pure silicate glass and have a trace of the quenching. This indicates that the particles could have been generated due to the melting of the HEPA filter in SGTS by the fire of H
detonation at Unit 3, and atomization followed by quenching of the molten materials by air blast of the explosion. Although the particles were mostly dispersed to the sea because of the wind direction, some of them deposited onto the lower elevation of R/B at Unit 3, could have been subsequently re-suspended and released into the environment, by the steam flow in the R/B caused by restart of the Unit 3 core cooling water injection at 2:30 of March 15.
Takahashi, Satoru*; Nota, Yoshiki*; Matsuda, Asahi*; Kawabata, Kuniaki; Suzuki, Tsuyoshi*; Takemura, Fumiaki*; Ogasawara, Kei*; Kaneko, Shunichi*
Journal of Signal Processing, 21(1), p.15 - 24, 2017/01
In recent years, many researchers try to observe the state of the global environment from marine information for the understanding of the global environment change. First, we introduce the recording system of underwater environment which is made by the authors. By using this system, we want to observe the change of global environment from the coral bleaching. In this paper, especially, we propose the generation method of underwater landmark which is used to measure the position of robot of oceanographic observation based on the dynamic image processing. In here, underwater landmark means the feature point in underwater image.
Taba, Ryo*; Takemura, Fumiaki*; Tansuriyavong, S.*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
Proceedings of 21st International Symposium on Artificial Life and Robotics (AROB 21st 2016) and 1st International Symposium on BioComplexity (ISBC-1) (Internet), p.395 - 399, 2016/01
Kinouchi, Nobuyuki; Oishi, Tetsuya; Noguchi, Hiroshi; Kato, Shohei; Ishizawa, Masato*
Radioisotopes, 50(9), p.403 - 407, 2001/09
no abstracts in English
Ikezawa, Yoshio
Kuki Seijo, 28(3), p.630 - 647, 1990/08
no abstracts in English
; ;
Hoken Butsuri, 19(1), p.25 - 32, 1984/00
no abstracts in English
; ;
Proc.5th Int.Symp.on Contamination Control, p.23 - 26, 1980/00
no abstracts in English
; ; Yabe, Akira
Proc.of 5th Int.Radiation Protection Association Congress, p.217 - 220, 1980/00
no abstracts in English
;
Journal of Applied Physics, 47(4), p.1355 - 1358, 1976/04
Times Cited Count：13no abstracts in English
; ; ; ;
Hoken Butsuri, 8(3), p.145 - 152, 1973/03
no abstracts in English
Onodera, Naoyuki; Idomura, Yasuhiro; Hasegawa, Yuta; Nakayama, Hiromasa; Shimokawabe, Takashi*; Aoki, Takayuki*
no journal, ,
This paper presents a novel data assimilation method in realistic turbulent boundary layer simulations for the realization of a wind digital twin. We have developed a plume dispersion simulation code named CityLBM based on a lattice Boltzmann method. CityLBM enables a real time ensemble simulation for several km square area by applying locally mesh-refinement method on GPU supercomputers. Mesoscale wind boundary conditions produced by a Weather Research and Forecasting Model are given as boundary conditions in CityLBM by using a nudging data assimilation method. In this study, we propose a dynamic nudging data assimilation method, where a particle filter optimizes the nudging coefficient based on the observation data. This approach gave reasonable agreements in vertical profiles of the wind speed, the wind direction, and the turbulent intensity compared to the observation data throughout the day, and enabled all-day simulations, where atmospheric conditions change significantly.
