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Tamura, Koji; Nakanishi, Ryuzo; Oba, Hironori; Karino, Takahiro; Shibata, Takuya; Taira, Takunori*; Wakaida, Ikuo
Journal of Nuclear Science and Technology, 8 Pages, 2024/00
Morishita, Yuki; Takasaki, Koji; Kitayama, Yoshiharu; Tagawa, Akihiro; Shibata, Takuya; Hoshi, Katsuya; Kaneko, Junichi*; Higuchi, Mikio*; Oura, Masatoshi*
Radiation Measurements, 160, p.106896_1 - 106896_10, 2023/01
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)This study proposes a newly developed phoswich alpha/beta detector that can discriminate alpha and beta particles emitted from the alpha and beta contaminations in the FDNPS site. The phoswich alpha/beta detector is made up of two layers of scintillators that detect alpha and beta particles. The pulse shape discrimination (PSD) method was used to detect alpha particles in high beta particle and high gamma-ray (comparable to gamma-ray dose rate near the FDNPS reactor building) environments. Due to a 23.3% full width at half maximum (FWHM) energy resolution for alpha particles, the detector can be used to distinguish between nuclear fuel materials such as plutonium and its radon progeny (Po-214). Moreover, the detector could distinguish alpha particles from Cs gamma rays with a dose rate background up to 9.0 mSv/h. It is the first to demonstrate that the developed phoswich detector can be used to discriminate and measure alpha and beta particles of the actual contaminated FDNPS samples.
Yamada, Tomonori; Daido, Hiroyuki*; Shibata, Takuya
Journal of Nuclear Science and Technology, 59(5), p.614 - 628, 2022/05
Times Cited Count:1 Percentile:16.97(Nuclear Science & Technology)Daido, Hiroyuki*; Yamada, Tomonori; Furukawa, Hiroyuki*; Ito, Chikara; Miyabe, Masabumi; Shibata, Takuya; Hasegawa, Shuichi*
Journal of Laser Applications, 33(1), p.012001_1 - 012001_16, 2021/02
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Suzui, Nobuo*; Shibata, Takuya; Yin, Y.-G.*; Funaki, Yoshihito*; Kurita, Keisuke; Hoshina, Hiroyuki*; Yamaguchi, Mitsutaka*; Fujimaki, Shu*; Seko, Noriaki*; Watabe, Hiroshi*; et al.
Scientific Reports (Internet), 10, p.16155_1 - 16155_9, 2020/10
Times Cited Count:2 Percentile:24.76(Multidisciplinary Sciences)Yamada, Tomonori; Takebe, Toshihiko*; Ishizuka, Ippei*; Daido, Hiroyuki*; Hanari, Toshihide; Shibata, Takuya; Omori, Shinya*; Kurosawa, Koichi*; Sasaki, Go*; Nakada, Masahiro*; et al.
Journal of Nuclear Science and Technology, 56(12), p.1171 - 1179, 2019/12
Times Cited Count:1 Percentile:11.41(Nuclear Science & Technology)We describe a new chipping technique combined with a water-jet technique as one of the candidate techniques for the retrieval of fuel debris and support structures as part of the decommissioning of the Fukushima Daiichi Nuclear Power Station. We performed proof-of-principle experiments to demonstrate the removal capability of metal parts, where we focused on the observation of removal processes from a metallic sample using a 5.5-kW continuous wave fiber laser combined with continuous and pulsed water jets.
Seko, Noriaki*; Hoshina, Hiroyuki*; Kasai, Noboru*; Shibata, Takuya; Saiki, Seiichi*; Ueki, Yuji*
Radiation Physics and Chemistry, 143, p.33 - 37, 2018/02
Times Cited Count:15 Percentile:85.51(Chemistry, Physical)Shibata, Takuya; Seko, Noriaki; Amada, Haruyo; Kasai, Noboru; Saiki, Seiichi; Hoshina, Hiroyuki; Ueki, Yuji
Radiation Physics and Chemistry, 119, p.247 - 252, 2016/02
Times Cited Count:11 Percentile:75.11(Chemistry, Physical)Seko, Noriaki; Shibata, Takuya; Kasai, Noboru; Ueki, Yuji; Saiki, Seiichi; Hoshina, Hiroyuki
Hoshasen To Sangyo, (138), p.9 - 12, 2015/06
no abstracts in English
Shibata, Takuya; Seko, Noriaki; Kasai, Noboru; Hoshina, Hiroyuki; Ueki, Yuji
International Journal of Organic Chemistry, 5(2), p.100 - 107, 2015/06
Shibata, Takuya; Seko, Noriaki; Amada, Haruyo; Kasai, Noboru; Saiki, Seiichi; Hoshina, Hiroyuki; Ueki, Yuji
Nihon Ion Kokan Gakkai-Shi, 26(1), p.9 - 14, 2015/01
Saiki, Seiichi; Shibata, Takuya; Hoshina, Hiroyuki; Ueki, Yuji; Kasai, Noboru; Seko, Noriaki
Nihon Ion Kokan Gakkai-Shi, 25(4), p.170 - 175, 2014/11
Ueki, Yuji; Saiki, Seiichi; Shibata, Takuya; Hoshina, Hiroyuki; Kasai, Noboru; Seko, Noriaki
International Journal of Organic Chemistry, 4(2), p.91 - 105, 2014/06
Grafted fibrous polymer with quaternary amine groups could function as a highly-efficient catalyst for biodiesel fuel (BDF) production. In this study, the optimization of grafted fibrous polymer (catalyst) and transesterification conditions for the effective BDF production was attempted through a batch-wise transesterification of triglyceride (TG) with ethanol (EtOH) in the presence of a cosolvent. Trimethylamine was the optimal quaternary amine group for the grafted fibrous catalyst. The optimal degree of grafting of the grafted fibrous catalyst was 170%. The optimal transesterification conditions were as follows: The molar quantity of quaternary amine groups, transesterification temperature, molar ratio of TG and EtOH, and primary alkyl alcohol were 0.8 mmol, 80C, 1:200, and 1-pentanol, respectively. The grafted fibrous catalyst could be applied to BDF production using natural oils. Furthermore, the grafted fibrous catalyst could be used repeatedly after regeneration involving three sequential processes, i.e., organic acid, alkali, and alcohol treatments, without any significant loss of catalytic activity.
Mikami, Takashi*; Nakano, Masanori*; Shibata, Takuya; Seko, Noriaki
Setsubi To Kanri, 47(4), p.95 - 99, 2013/04
no abstracts in English
Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya*; Aketagawa, Yasushi*; Takahashi, Makikatsu*; Yoshii, Akihiro*; Tsunoda, Yasuhiko*; Seko, Noriaki
Radiation Physics and Chemistry, 81(8), p.1033 - 1035, 2012/08
Times Cited Count:4 Percentile:32.06(Chemistry, Physical)Kasai, Noboru; Hoshina, Hiroyuki; Seko, Noriaki; Shibata, Takuya*; Takahashi, Makikatsu*
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 46, 2012/01
no abstracts in English
Takigami, Machiko*; Nagasawa, Naotsugu; Hiroki, Akihiro; Kasai, Noboru; Yoshii, Fumio; Tamada, Masao; Takigami, Shoji*; Shibata, Takuya*; Aketagawa, Yasushi*; Ozaki, Masuo*
Transactions of the Materials Research Society of Japan, 35(3), p.647 - 650, 2010/09
There are many livestock farmers in Gunma Prefecture. Many of the farms are located under Mt. Akagi and Haruna, which attract tourists. Furthermore, rivers around the mountains are source of water supply to metropolitan area. Therefore, the waste treatments are very important. Regulations of smell and COD (chemical oxygen demand) are severe in Gunma Prefecture. Although there is no regulation for color of drain water, color in secondary treated water from livestock urine waste has been one of the major concerns for livestock farmers. The color is a metabolite of microorganisms and not easy to be removed. People have tried to remove the color by ozone treatment, absorption using activated carbon or soils. An absorbent was prepared by radiation grafting; fibers were irradiated with Co -rays and some kinds of monomers were grafted onto the fibers. The absorbent thus prepared were used to decolorize the secondary treated water. The color and COD were removed by the absorbent, however, COD removal was more difficult than decolorization. Degree of grafting (weight increase expressed in % by grafting reaction to initial weight of the fiber), treated water/absorbent ratio, flow rate of treated water, and direction of flow affected color and COD removal. The used absorbent could be used repeatedly after washing.
Kasai, Noboru; Hoshina, Hiroyuki; Seko, Noriaki; Shibata, Takuya*; Takahashi, Makikatsu*
no journal, ,
no abstracts in English
Kasai, Noboru; Hoshina, Hiroyuki; Seko, Noriaki; Shibata, Takuya*; Takahashi, Makikatsu*
no journal, ,
no abstracts in English
Seko, Noriaki; Kasai, Noboru; Hoshina, Hiroyuki; Shibata, Takuya*; Takahashi, Makikatsu*
no journal, ,
The majority of metal adsorbents are composed of spherical resins that are prepared by the co-polymerization of styrene and divinylbenzene. In general, synthetic polymers such as polyethylene and polypropylene have been used as trunk polymer fibers due to their reactivity in the grafting process and high mechanical strength. In the case of fibrous adsorbents, these superior characteristics depend on the high diffusion rate of metal ions in the fibrous adsorbent, in which the fiber diameters of 10-20 m are ten times smaller than those of the spherical resin adsorbents. In this study, a fibrous adsorbent for metal ions was synthesized by radiation-induced emulsion graft polymerization of 2-hydroxyethyl methacrylate phosphoric acid monomer (PA) which composed of phosphoric acid mono (50%) and di (50%) ethyl methacrylate ester onto nonwoven cotton fabric. The resulting PA-type adsorbents were achieved around 150% of degree of grafting.