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Otosaka, Shigeyoshi; Tanaka, Takayuki; Togawa, Orihiko; Amano, Hikaru
JAEA-Conf 2008-003, p.67 - 70, 2008/04
An apparent age of particulate organic matter (POM) in seawater that is estimated from isotopic ratio of radiocarbon is convenient indicator for verifying transport processes of POM in the ocean. However, it is suggested that isotopic ratio of radiocarbon also reflects mixing of old POM from the surrounding regions and seafloor as well as an age of the POM. In this study, we discuss the cause of the variation in apparent age of POM from radiocarbon measurements of various particulate materials obtained at the northeastern Japan Sea and the northwestern North Pacific.
C measurement in seawaterOtosaka, Shigeyoshi; Tanaka, Takayuki; Togawa, Orihiko; Amano, Hikaru; Aramaki, Takafumi*
JAEA-Conf 2008-003, p.63 - 66, 2008/04
Research Group for Environmental Science, JAEA has been carried out oceanographic observations in the Japan Sea. More than 3000 seawater samples for measurement of radiocarbon were collected during the observations. Radiocarbon in seawater samples was measured at AMS facility in JAEA Mutsu. In this presentation, circulation of water mass in the northern Japan Sea inferred from the radiocarbon measurement is discussed.
Otosaka, Shigeyoshi; Amano, Hikaru; Kabuto, Shoji; Kinoshita, Naoki; Tanaka, Takayuki
JAEA-Conf 2008-003, p.21 - 23, 2008/04
no abstracts in English
I concentration in soil by AMSKokubun, Yuji; Nakano, Masanao; Takeishi, Minoru
JAEA-Conf 2008-003, p.32 - 35, 2008/04
no abstracts in English
Tanaka, Takayuki; Otosaka, Shigeyoshi; Amano, Hikaru; Togawa, Orihiko
JAEA-Conf 2008-003, p.71 - 74, 2008/04
no abstracts in English
I by JAEA AMS MUTSU and application to study of iodine migrationSuzuki, Takashi; Kabuto, Shoji; Kinoshita, Naoki; Amano, Hikaru; Togawa, Orihiko
JAEA-Conf 2008-003, p.24 - 27, 2008/04
no abstracts in English
Kabuto, Shoji; Kinoshita, Naoki; Watanabe, Yukiya*; Baba, Masami*; Amano, Hikaru
JAEA-Conf 2008-003, p.13 - 16, 2008/04
no abstracts in English
Atarashi-Andoh, Mariko; Koarashi, Jun; Ishizuka, Shigehiro*; Saito, Takeshi*; Hirai, Keizo*
JAEA-Conf 2008-003, p.75 - 78, 2008/04
C-14 is an effective tracer in investigating the carbon dynamics in the environment. In this study, the measurements of C-14 in soil organic matter (SOM) in a deciduous forest were used to determine the turnover time and CO
production rate from SOM. In addition, monthly measurements of carbon isotopic ratios in soil-respired CO and atmospheric CO were conducted to characterize the seasonal variation of the contribution of each CO source, such as SOM decomposition and root respiration.
Amano, Hikaru; Kabuto, Shoji; Kinoshita, Naoki
JAEA-Conf 2008-003, p.9 - 12, 2008/04
no abstracts in English
Amano, Hikaru; Yamamichi, Miwako*; Baba, Masami*; Momoshima, Noriyuki*; Sugihara, Shinji*; Ueda, Yusuke*; Nakamura, Yasuhiro*
JAEA-Conf 2008-003, p.84 - 87, 2008/04
no abstracts in English
and its carbon isotope analyses in the semi-natural woods on the campus of Hokkaido UniversityFujiyoshi, Ryoko*; Haraki, Yukihide*; Sumiyoshi, Takashi*; Amano, Hikaru
JAEA-Conf 2008-003, p.79 - 83, 2008/04
Carbon dioxide in soil air has been monitored in the holes at 30 and 100 cm in depth under a cool-temperate deciduous stand on the campus of Hokkaido University since June in 2007. Air samples were collected periodically from the holes, and also from the atmosphere in the woods (2 m in height from the soil surface). Carbon isotopic analyses of the CO samples were performed by AMS at the Mutsu Facility of the Japan Atomic Energy Agency (JAEA-AMS-MUTSU). Preliminary results show that CO in the woods including the air at 2 m in height may result from mixing of atmospheric air and soil components of various sources, such as CO from contemporary soil organic matter and old carbon of deep source to a varying degree depending on meteorological and biological conditions.
Yamada, Yoshimune*; Yasuike, Kaeko*; Amano, Hikaru
JAEA-Conf 2008-003, p.59 - 62, 2008/04
Concentrations of organically-bound C in the tree-ring cellulose samples were analyzed by the accelerator mass spectrometric measurement (hereafter the AMS measurement) and compared with those of the same samples by the liquid scintillation counting measurement (hereafter the LSC measurement). This was done to determine the reliability of LSC measurement. An important result is that the 
C values analyzed by the AMS measurement demonstrated lower levels of approximately 15permil than those by the LSC measurement. These deviations are considered to be caused by indeterminate errors in the counting of the specific activity of the standard reference of C used for the LSC measurement. The synthesized benzene prepared from NIST oxalic acid (SRM4990C) was used as the standard reference of C in the LSC measurement.
Shima, Shigeki*; Gasa, Shinichi*; Amano, Hikaru; Nagao, Seiya*; Yamamoto, Masayoshi*; Momoshima, Noriyuki*; Furukawa, Masahide*; Kimura, Hideki*; Kawamura, Hisao*
JAEA-Conf 2008-003, p.28 - 31, 2008/04
Concentrations of I in surface seawater around Japan were approximately 2
10
atoms/L in literatures. However, the atomic ratio of iodine to cesium was ten times as high as that of the global fallout. The origin of I in the water columns seems to be difficult to be explained by only the global fallout. Discharge from European plants was one of the possible origins of iodine from the standpoint of air mass trajectory analysis. Concentration of I in rain water was 10 times higher than that in surface seawater. Anthropogenic inorganic iodine in surface seawater predominantly dissolves as an iodide ion (I
).
Kubota, Takumi*; Nakano, Tomoko*; Amano, Hikaru; Suzuki, Takashi; Mahara, Yasunori*
JAEA-Conf 2008-003, p.36 - 39, 2008/04
In analysis of environmental iodine, samples containing low I-129 and low iodine amount are subject to contamination from reagents and apparatus. We measured the isotopic ratio of I-129/I-127 in brine that was collected at Mobara in Chiba prefecture and was characterized as having a high iodine concentration and a low isotopic ratio. The results, however, showed high isotopic ratios. We suspected that the contamination was caused by using halogen containing reagents because the samples treated with Cl-form anion exchange resin in iodine extraction process were strongly contaminated. In this study, we have conducted halogen-free extraction processes such as ion exchange and solvent extraction whose recovery has been investigated with 
spectrometry of I-126 produced through photonuclear reaction with the KURRI LINAC. The total iodine recovery through ion exchange with NO
-form anion exchange resin and solvent extraction with dodecane was more than 80%.
