Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 86

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

Reducing the effect of noise generated from stepper motor for H0 collimator in J-PARC RCS

Fujiyama, Hiroki*; Takahashi, Hiroki; Okabe, Kota; Ito, Yuichi*; Hatakeyama, Shuichiro; Suzuki, Takahiro*; Otsu, Satoru*; Yamakawa, Ryuto*

Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.529 - 531, 2023/01

Stepper motors are used for mechanical drive in collimators and wire scanner monitors of J-PARC accelerators. Many of these drive unit hardware have been used since the beginning of J-PARC construction, and it is necessary to take measures against aging deterioration. Therefore, we started updating the motor and control system from around 2017. However, when the stepper motor was updated to the current product in the RCS H0 collimator, a malfunction occurred. This is because the drive unit control system cannot correctly recognize the state of the LS (limit switch) due to the noise generated by the motor driver, which hinders the operation. When the noise generated from the old and new stepper motors was measured in a simple test environment for confirmation, it was found that the current product was clearly larger. As a countermeasure, when the wiring of the stepper motor, which was bundled in a single multi-core cable, was separated into separate cables for the power system and LS signal system, the noise level was reduced to about 1/10 and normal operation was restored. I was able to. In this case, we report on noise countermeasures for the RCS H0 collimator drive unit.

Journal Articles

Radiation exposure and oxidative stress status of wild Japanese macaques in the ex-evacuation zone of the Fukushima Daiichi Nuclear Power Plant accident

Ishikawa, Ryoya*; Suzuki, Masatoshi*; Kino, Yasushi*; Endo, Satoru*; Nakajima, Hiroo*; Oka, Toshitaka; Takahashi, Atsushi*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Shinoda, Hisashi*; et al.

KEK Proceedings 2022-2, p.61 - 66, 2022/11

The balance between oxidative stress and antioxidant activity, which is a defense mechanism against oxidative stress, was investigated in the liver and bladder of wild Japanese macaques captured in Fukushima Prefecture. No significant induction of oxidative stress by exposure to environmental radionuclides after the Fukushima nuclear accident was observed, suggesting that the stress defense mechanism of the organism is activated in some organs.

Journal Articles

Tracking method of medaka considering proximity state

Sakakibara, Takanori*; Takahashi, Satoru*; Kawabata, Kuniaki; Oda, Shoji*

2021 IEEE/SICE International Symposium on System Integration (SII 2021), Vol.2, p.517 - 523, 2021/07

 Times Cited Count:0 Percentile:0

In biology, it is expected to understand the mechanism of herd development by analyzing crowd behavior. Currently, medaka (Oryzias latipes) is often used when conducting such research because of its ease of breeding and experimentation. However, when conducting such studies, it is very difficult to manually obtain herd data. In this article, in order to analyze the behavior of medaka, we will introduce a method to automatically extract the swimming trajectory of medaka from time-series images and acquire the data necessary for behavior analysis. In particular, the improvement of extraction accuracy is achieved by processing the overlap state and adjoin state of medaka in the image.

Journal Articles

Thermally altered subsurface material of asteroid (162173) Ryugu

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.

Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03

 Times Cited Count:30 Percentile:96.87(Astronomy & Astrophysics)

Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 $$^{circ}$$C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 $$^{circ}$$C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.

Journal Articles

Calculations for ambient dose equivalent rates in nine forests in eastern Japan from $$^{134}$$Cs and $$^{137}$$Cs radioactivity measurements

Malins, A.; Imamura, Naohiro*; Niizato, Tadafumi; Takahashi, Junko*; Kim, M.; Sakuma, Kazuyuki; Shinomiya, Yoshiki*; Miura, Satoru*; Machida, Masahiko

Journal of Environmental Radioactivity, 226, p.106456_1 - 106456_12, 2021/01

 Times Cited Count:4 Percentile:36.59(Environmental Sciences)

Journal Articles

Corrosion resistance of a cast steel overpack for high-level radioactive waste disposal in Japan

Ogawa, Yusuke*; Suzuki, Satoru*; Taniguchi, Naoki; Kawasaki, Manabu*; Suzuki, Hiroyuki*; Takahashi, Rieko*

Materials and Corrosion, 72(1-2), p.52 - 66, 2021/01

 Times Cited Count:2 Percentile:13.1(Materials Science, Multidisciplinary)

Cast steel is one of the promising alternative to forged steel that is the current reference material for carbon steel overpack. In this study, the full-scale cast steel overpack was produced experimentally and the distribution of casting defects were investigated. The corrosion test regarding corrosion rate and stress corrosion cracking (SCC) susceptibility were also conducted using samples taken from the full-scale cast steel overpack and the corrosion resistance of cast steel was compared with that of forged steel. From above two corrosion tests, it can be said that the corrosion resistance of cast steel is mostly the same as that of forged steel.

Journal Articles

External exposure dose estimation by electron spin resonance technique for wild Japanese macaque captured in Fukushima Prefecture

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.

Radiation Measurements, 134, p.106315_1 - 106315_4, 2020/06

 Times Cited Count:4 Percentile:54.54(Nuclear Science & Technology)

The relationship between the CO$$_{2}$$ radical intensity and the absorbed dose (dose response curve) of tooth enamel of Japanese macaque was observed by electron spin resonance and the detection limit of our system was estimated to be 33.5 mGy, which is comparable to the detection limit for human molar teeth. Using the dose response curve, external exposure dose for seven wild Japanese macaques captured in Fukushima prefecture were examined. The results suggest that the external exposure dose for the wild Japanese macaques were ranged between 45 mGy to 300 mGy.

JAEA Reports

Prototype fast breeder reactor Monju; Its history and achievements (Translated document)

Mitsumoto, Rika; Hazama, Taira; Takahashi, Keita; Kondo, Satoru

JAEA-Technology 2019-020, 167 Pages, 2020/03

JAEA-Technology-2019-020.pdf:21.06MB
JAEA-Technology-2019-020-high-resolution1.pdf:47.3MB
JAEA-Technology-2019-020-high-resolution2.pdf:34.99MB
JAEA-Technology-2019-020-high-resolution3.pdf:48.74MB
JAEA-Technology-2019-020-high-resolution4.pdf:47.83MB
JAEA-Technology-2019-020-high-resolution5.pdf:18.35MB
JAEA-Technology-2019-020-high-resolution6.pdf:49.4MB
JAEA-Technology-2019-020-high-resolution7.pdf:39.78MB

The prototype fast breeder reactor Monju has produced valuable technological achievements through design, construction, operation and maintenance over half a century since 1968. This report compiles the reactor technologies developed for Monju, including the areas: history and major achievements, design and construction, commissioning, safety, reactor physics, fuel, systems and components, sodium technology, materials and structures, operation and maintenance, and accidents and failures.

Journal Articles

Extraction method of swimming trajectory for behavior analysis of medaka (${it Oryzias Latipes}$)

Matsuda, Asahi*; Takahashi, Satoru*; Kawabata, Kuniaki; Oda, Shoji*; Kaneko, Shunichi*

Denki Gakkai Rombunshi, D, 139(4), p.424 - 432, 2019/04

Journal Articles

Generation method of underwater landmarks for ocean observation

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.

Journal Articles

Bithiophene with winding vine-shaped molecular asymmetry; Preparation, structural characterization, and enantioselective synthesis

Toyomori, Yuka*; Tsuji, Satoru*; Mitsuda, Shinobu*; Okayama, Yoichi*; Ashida, Shiomi*; Mori, Atsunori*; Kobayashi, Toru; Miyazaki, Yuji; Yaita, Tsuyoshi; Arae, Sachie*; et al.

Bulletin of the Chemical Society of Japan, 89(12), p.1480 - 1486, 2016/09

 Times Cited Count:8 Percentile:29.66(Chemistry, Multidisciplinary)

Journal Articles

Method of dynamic image measurement for analyzing cricket behavior

Takahashi, Satoru*; Okuda, Yasutake*; Kawabata, Kuniaki; Aonuma, Hitoshi*; Sato, Yutaka*; Iwata, Kenji*

Journal of Signal Processing, 20(2), p.65 - 74, 2016/03

Journal Articles

Spin hydrodynamic generation

Takahashi, Ryo*; Matsuo, Mamoru; Ono, Masao; Harii, Kazuya; Chudo, Hiroyuki; Okayasu, Satoru; Ieda, Junichi; Takahashi, Saburo*; Maekawa, Sadamichi; Saito, Eiji

Nature Physics, 12, p.52 - 56, 2016/01

 Times Cited Count:102 Percentile:96.38(Physics, Multidisciplinary)

Journal Articles

Barnett effect in paramagnetic states

Ono, Masao; Chudo, Hiroyuki; Harii, Kazuya; Okayasu, Satoru; Matsuo, Mamoru; Ieda, Junichi; Takahashi, Ryo*; Maekawa, Sadamichi; Saito, Eiji

Physical Review B, 92(17), p.174424_1 - 174424_4, 2015/11

 Times Cited Count:29 Percentile:74.8(Materials Science, Multidisciplinary)

Journal Articles

Performance of a remotely located muon radiography system to identify the inner structure of a nuclear plant

Fujii, Hirofumi*; Hara, Kazuhiko*; Hashimoto, Shugo*; Ito, Fumiaki*; Kakuno, Hidekazu*; Kim, S.*; Kochiyama, Mami; Nagamine, Kanetada*; Suzuki, Atsuto*; Takada, Yoshihisa*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2013(7), p.073C01_1 - 073C01_20, 2013/07

 Times Cited Count:25 Percentile:76.83(Physics, Multidisciplinary)

Journal Articles

Uniaxial-pressure control of magnetic phase transitions in a frustrated magnet CuFe$$_{1-x}$$Ga$$_{x}$$O$$_{2}$$ (x =0, 0.018)

Nakajima, Taro*; Mitsuda, Setsuo*; Takahashi, Keiichiro*; Yoshitomi, Keisuke*; Masuda, Kazuya*; Kaneko, Chikafumi*; Homma, Yuki*; Kobayashi, Satoru*; Kitazawa, Hideaki*; Kosaka, Masashi*; et al.

Journal of the Physical Society of Japan, 81(9), p.094710_1 - 094710_8, 2012/09

Journal Articles

Uniaxial-pressure control of magnetic phase transitions in a frustrated magnet CuFe$$_{1-x}$$Ga$$_{x}$$O$$_{2}$$ ($$x$$ = 0, 0.018)

Nakajima, Taro*; Mitsuda, Setsuo*; Takahashi, Keiichiro*; Yoshitomi, Keisuke*; Masuda, Kazuya*; Kaneko, Chikafumi*; Homma, Yuki*; Kobayashi, Satoru*; Kitazawa, Hideaki*; Kosaka, Masashi*; et al.

Journal of the Physical Society of Japan, 81(9), p.094710_1 - 094710_8, 2012/09

 Times Cited Count:11 Percentile:63.34(Physics, Multidisciplinary)

JAEA Reports

Research and development for treatment and disposal technologies of TRU waste; JFY 2010 annual report

Kamei, Gento; Honda, Akira; Oda, Chie; Hirano, Fumio; Ichige, Satoru; Kurimoto, Yoshitaka; Hoshino, Seiichi; Akagi, Yosuke; Sato, Nobuyuki; Takahashi, Kuniaki; et al.

JAEA-Research 2012-010, 80 Pages, 2012/06

JAEA-Research-2012-010.pdf:7.45MB

Based on Japanese governmental policy and general scheme, research and development of geological disposal technology for TRU waste has been proceeding to improve reliability of the safety assessment of the co-locational disposal of TRU waste and of HLW, to expand the basement of generic safety assessment, and to develop the alternative technology to cope with the broad geologic environment of Japan. Japan Atomic Energy Agency is dealing with the assignments in the governmental generic scheme. We report here the progress of the studies at the end of H22 (2010) Japanese fiscal year and their products during the last 5 years. These include (1) evaluation of long-term mechanical stability in the near-field including development of a creep mode of rock and analyses of mechanical behavior of TRU waste repository, (2) performance assessment of the disposal system including cementitious material alteration, bentonite and hostrock alteration with alkaline solution and nitrate effect, and (3) alternative technology development including decomposition of nitrate.

Journal Articles

To participate in the disaster reconstruction committee formulated vision Tomioka-machi

Abe, Sadayoshi; Kuwae, Yoshiaki*; Sasaki, Satoru*; Takahashi, Kazutoshi*

Genshiryoku, hoshasen Bukaiho (Internet), (10), p.6 - 8, 2012/03

Between January 30, 2012 August 26, 2011, the support for the correct understanding of nuclear and radiation due to comments and advice to participate in disaster reconstruction committee formulated vision of the Tomioka town, as a professional Engineers, Japan was carried out, As a result, the vision I hope to go back to town Tomioka are taken together to form all townspeople have been developed.

Journal Articles

Repetition Rate Multiplication: RRM, an advanced measuring method planed for the backscattering instrument, ${it DNA}$ at the MLF, J-PARC

Takahashi, Nobuaki; Shibata, Kaoru; Kawakita, Yukinobu; Nakajima, Kenji; Inamura, Yasuhiro; Nakatani, Takeshi; Nakagawa, Hiroshi; Fujiwara, Satoru; Sato, Taku*; Tsukushi, Itaru*; et al.

Journal of the Physical Society of Japan, 80(Suppl.B), p.SB007_1 - SB007_4, 2011/12

 Times Cited Count:6 Percentile:43.5(Physics, Multidisciplinary)

86 (Records 1-20 displayed on this page)