Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Zhang, J.*; Kuang, L.*; Mou, Z.*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko; Li, Y.*; Tang, X.*; Wang, Y.-P.*; Pe
uelas, J.*; et al.
Plant and Soil, 481(1-2), p.349 - 365, 2022/12
Times Cited Count：3 Percentile：22.98(Agronomy)Nagano, Hirohiko; Nakayama, Masataka*; Katata, Genki*; Fukushima, Keitaro*; Yamaguchi, Takashi*; Watanabe, Makoto*; Kondo, Toshiaki*; Atarashi-Andoh, Mariko; Kubota, Tomohiro*; Tateno, Ryunosuke*; et al.
Soil Science and Plant Nutrition, 67(5), p.606 - 616, 2021/10
Times Cited Count：2 Percentile：19.73(Plant Sciences)We analyzed the relationships between nitrogen deposition (deposition of nitrate and ammonium ions) and soil microbial properties in a cool temperate forest surrounded by normally fertilized pasture grasslands in northern Japan. The aim of the present study was to gain the primary information on soil microbial response to moderately elevated nitrogen deposition (
10 kg N ha
y). We established three experimental plots in the forest edge adjacent to grasslands and other three plots in the forest interior at least 700 m away from the grasslands. During May to November 2018, nitrogen deposition in each plot was measured. In August 2018, litter and soil (0-5 cm depth) samples were collected from all plots to measure net nitrogen mineralization and nitrification rates as indicators of microbial activity, and microbial biomass carbon and nitrogen and various gene abundances (i.e. bacterial 16S rRNA, fungal ITS, bacterial amoA, and archaeal amoA genes) as indicators of microbial abundance and structure. Nitrogen deposition in the forest edge was 1.4-fold greater than that in the forest interior, even while the maximum deposition was 3.7 kg N ha. Nitrogen deposition was significantly correlated to the net nitrogen mineralization and nitrification rates and the 16S rRNA and bacterial amoA gene abundances. Microbial community structures were different between litter and soil samples but were similar between the forest edge and interior. Significant correlations of nitrogen deposition to the soil carbon to nitrogen ratio, and the nitrate and ammonium contents were also observed. Thus, our results show that moderately elevated nitrogen deposition in nitrogen-limited forest edges can stimulate microbial activities and abundances in soils.
Ishitsuka, Etsuo; Matsunaka, Kazuaki*; Ishida, Hiroki*; Ho, H. Q.; Ishii, Toshiaki; Hamamoto, Shimpei; Takamatsu, Kuniyoshi; Kenzhina, I.*; Chikhray, Y.*; Kondo, Atsushi*; et al.
JAEA-Technology 2019-008, 12 Pages, 2019/07
JAEA-Technology-2019-008.pdf:2.37MB
As a summer holiday practical training 2018, the feasibility study for nuclear design of a nuclear battery using HTTR core was carried out. As a result, it is become clear that the continuous operations for about 30 years at 2 MW, about 25 years at 3 MW, about 18 years at 4 MW, about 15 years at 5 MW are possible. As an image of thermal design, the image of the nuclear battery consisting a cooling system with natural convection and a power generation system with no moving equipment is proposed. Further feasibility study to confirm the feasibility of nuclear battery will be carried out in training of next fiscal year.
Takeuchi, Hiroshi; Sugimoto, Masayoshi; Nakamura, Hiroo; Yutani, Toshiaki*; Ida, Mizuho*; Jitsukawa, Shiro; Kondo, Tatsuo; Matsuda, Shinzaburo; Matsui, Hideki*; Shannon, T. E.*; et al.
Fusion Energy 2000 (CD-ROM), 5 Pages, 2001/00
no abstracts in English
Hoshino, Katsumichi; Yamamoto, Takumi; Kawashima, Hisato; Suzuki, Norio; Uesugi, Yoshihiko; Mori, Masahiro; ; Kasai, Satoshi; Kawakami, Tomohide; Matsuda, Toshiaki; et al.
Physical Review Letters, 63(7), p.770 - 773, 1989/08
Times Cited Count：24 Percentile：80.15(Physics, Multidisciplinary)no abstracts in English
Hoshino, Katsumichi; Yamamoto, Takumi; Kawashima, Hisato; Suzuki, Norio; Uesugi, Yoshihiko; ; Kasai, Satoshi; Kawakami, Tomohide; Matsuda, Toshiaki; Miura, Yukitoshi; et al.
JAERI-M 89-038, 7 Pages, 1989/03
no abstracts in English
Sengoku, Seio; ; Hoshino, Katsumichi; Kasai, Satoshi; Kawakami, Tomohide; Kawashima, Hisato; Kondo, Takashi*; Maeda, Hikosuke; Matsuda, Toshiaki; Matsumoto, Hiroshi; et al.
Journal of Nuclear Materials, 162-164, p.667 - 673, 1989/00
Times Cited Count：4 Percentile：49.15(Materials Science, Multidisciplinary)no abstracts in English
Oyama, Koichi; Katsurai, Kiyomichi; Kondo, Yoshikazu; Washiya, Tadahiro; Myochin, Munetaka; Nagata, Masanobu*; Horiuchi, Nobutake*; Chikazawa, Takahiro*; Kikuchi, Toshiaki*
no journal, ,
no abstracts in English
Okuda, Eiji; Fujinaka, Hideaki; Suzuki, Toshiaki; Shimizu, Hisashi*; Kondo, Katsumi*
no journal, ,
no abstracts in English
Nagaishi, Yoshihide*; Fukuda, Toshiaki*; Kondo, Akira*; Sumita, Junya; Sakaba, Nariaki
no journal, ,
Fine-Grained isotropic graphite shows higher strength making it a promising material for the graphite component of High Temperature Gas-cooled Reactor (HTGR) and Very High Temperature Reactor (VHTR). There are two kinds of considerations about lifetime of graphite components under neutron irradiation condition. One consideration is determined based on dimensional changes due to neutron irradiation. In this consideration, small dimensional change with much amount of neutron irradiation is preferable. The other consideration is determined based on a margin between the specified minimum ultimate strengths and the residual stresses induced by neutron irradiation. In this consideration, strength of graphite components is important property to decide lifetime. It is expected that development of new fine-grained isotropic nuclear grade graphite possessing higher strength will contribute toward added design margins and an extension of the lifetime of graphite components, which likely improve the reactor economy very significantly. Furthermore, from the viewpoint of graphite waste, it is also expected to decrease the exchange frequency of core components. Tokai Carbon Co., Ltd. has developed new nuclear grade graphite with higher strength and characterization of them is being carried out. This presentation shows the R&D plan and the initial results of mechanical and thermal properties of un-irradiated nuclear grade graphite.
Fujitsuka, Kunihiro*; Kondo, Akira*; Sumita, Junya; Sakaba, Nariaki; Fukuda, Toshiaki*
no journal, ,
High Temperature Gas-cooled Reactor (HTGR) including High Temperature engineering Test Reactor (HTTR) constructed by Japan Atomic Energy Agency (JAEA) and Very High Temperature Reactor (VHTR) are able to supply high temperature helium gas at the reactor outlet, and possess inherent safety. Fine-Grained isotropic graphite with high strength is used for the in-components of HTGR. In the case of severe accident, for example air ingress accident, it is desirable that oxidation-resistant graphite is used for the in-component of HTGR. One of the effective methods for oxidation-resistant property on graphite is to coat the surface with ceramics, such as SiC, which forms SiO
layer when it oxidizes. This method is one of the general industrial methods called chemical vapor deposition (CVD). Tokai Carbon Co., Ltd. (Tokai carbon) and JAEA launched R&Ds to develop the oxidation-resistant graphite. Tokai Carbon manufactured the oxidation-resistant graphite coated with SiC by CVD etc., and oxidation test and observation of surface condition before and after oxidation were carried out. Moreover, irradiation test using WWR-K research reactor in Institute of Nuclear Physics of the Republic of Kazakhstan (INP) was carried out and post-irradiation examination will begin soon. This presentation shows the oxidation behaviour of the oxidation-resistant graphite according to weight change of specimens, and the surface condition of the specimen according to surface and cross section observation of specimens before and after oxidation.
Liang, N.*; Chiang, P.-N.*; Wang, Y.*; Teramoto, Munemasa*; Takagi, Kentaro*; Kondo, Toshiaki*; Koarashi, Jun; Zhang, Y.*; Li, S.*; Fang, J.*; et al.
no journal, ,
Takagi, Kentaro*; Liang, N.*; Aguilos, M.*; Teramoto, Munemasa*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko
no journal, ,
Kondo, Toshiaki*; Teramoto, Munemasa*; Nakane, Kaneyuki*; Takagi, Kentaro*; Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*
no journal, ,
Teramoto, Munemasa*; Kondo, Toshiaki*; Liang, N.*; Zeng, J.*; Nakane, Kaneyuki*; Koarashi, Jun; Atarashi-Andoh, Mariko
no journal, ,
Teramoto, Munemasa*; Kondo, Toshiaki*; Liang, N.*; Zeng, J.*; Nakane, Kaneyuki*; Koarashi, Jun; Atarashi-Andoh, Mariko
no journal, ,
Nagano, Hirohiko; Atarashi-Andoh, Mariko; Fukushima, Keitaro*; Nakayama, Masataka*; Katata, Genki*; Yamaguchi, Takashi*; Watanabe, Makoto*; Kondo, Toshiaki*; Tateno, Ryunosuke*; Koarashi, Jun
no journal, ,
no abstracts in English
Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Kentaro*; Kondo, Toshiaki*; Teramoto, Munemasa*; Nagano, Hirohiko; Kokubu, Yoko; Takagi, Masahiro*; Ishida, Sachinobu*; Hiradate, Shuntaro*; et al.
no journal, ,
no abstracts in English
Takagi, Kentaro*; Liang, N.*; Aguilos, M.*; Kira, R.*; Teramoto, Munemasa*; Kobayashi, Makoto*; Sun, L.*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko
no journal, ,
no abstracts in English
Kondo, Toshiaki*; Teramoto, Munemasa*; Takagi, Kentaro*; Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*
no journal, ,
no abstracts in English
