Flow filtration/adsorption and simultaneous monitoring technologies of radiocesium Cs in river water

Enomoto, Kazuyuki*; Hoshina, Hiroyuki*; Kasai, Noboru*; Kurita, Keisuke; Ueki, Yuji*; Nagao, Yuto*; Yin, Y.-G.*; Suzui, Nobuo*; Kawachi, Naoki*; Seko, Noriaki*

Chemical Engineering Journal, 460, p.141696_1 - 141696_9, 2023/03

https://doi.org/10.1016/j.cej.2023.141696

This study develops a method that combines a radiation-grafting fibrous Cs-adsorbent filter of ammonium molybdophosphate (AMP) and a Ce:GdAlGaO scintillator based -ray detector for in situ measurements of the activity concentrations of Cs in a continuous water flow.

"Live-autoradiography" technique reveals genetic variation in the rate of Fe uptake by barley cultivars

Higuchi, Kyoko*; Kurita, Keisuke; Sakai, Takuro; Suzui, Nobuo*; Sasaki, Minori*; Katori, Maya*; Wakabayashi, Yuna*; Majima, Yuta*; Saito, Akihiro*; Oyama, Takuji*; et al.

Plants (Internet), 11(6), p.817_1 - 817_11, 2022/03

https://doi.org/10.3390/plants11060817

Genetic diversity in the rate of Fe uptake by plants has not been broadly surveyed among plant species or genotypes, although plants have developed various Fe acquisition mechanisms. We adopted the "Live-autoradiography" technique with radioactive Fe to directly evaluate the uptake rate of Fe by barley cultivars from a nutrient solution containing a very low concentration of Fe. Our observations revealed that the ability to acquire Fe from the low Fe solution was not always the sole determinant of tolerance to Fe deficiency among the barley genotypes.

Noninvasive imaging of hollow structures and gas movement revealed the gas partial-pressure-gradient-driven long-distance gas movement in the aerenchyma along the leaf blade to submerged organs in rice

Yin, Y.-G.*; Mori, Yoshinao*; Suzui, Nobuo*; Kurita, Keisuke; Yamaguchi, Mitsutaka*; Miyoshi, Yuta*; Nagao, Yuto*; Ashikari, Motoyuki*; Nagai, Keisuke*; Kawachi, Naoki*

New Phytologist, 232(5), p.1974 - 1984, 2021/12

https://doi.org/10.1111/nph.17726

Rice () plants have porous or hollow organs consisting of aerenchyma, which is presumed to function as a low-resistance diffusion pathway for air to travel from the foliage above the water to submerged organs. However, gas movement in rice plants has yet to be visualized in real time. In this study involving partially submerged rice plants, the leaves emerging from the water were fed nitrogen-13-labeled nitrogen ([N]N) tracer gas, and the gas movement downward along the leaf blade, leaf sheath, and internode over time was monitored.

Non-invasive C-imaging revealed the spatiotemporal variability in the translocation of photosynthates into strawberry fruits in response to increasing daylight integrals at leaf surface

Miyoshi, Yuta*; Hidaka, Kota*; Yin, Y.-G.*; Suzui, Nobuo*; Kurita, Keisuke; Kawachi, Naoki*

Frontiers in Plant Science (Internet), 12, p.688887_1 - 688887_14, 2021/07

https://doi.org/10.3389/fpls.2021.688887

In this study, C-photosynthate translocation into strawberry fruits in individual plants was visualized non-invasively and repeatedly using a positron emission tracer imaging system (PETIS) to assess the spatiotemporal variability in the translocation dynamics in response to increasing daylight integrals. This is the first study to use C-radioisotopes to clarify the spatiotemporal variability in photosynthate translocation from source leaves to individual sink fruits in vivo in response to increasing daylight integrals at a high spatiotemporal resolution.

Neutron Radiography Facility; TNRF and CNRF

Kurita, Keisuke; Iikura, Hiroshi

Hamon, 31(1), p.11 - 13, 2021/02

https://doi.org/10.5611/hamon.31.1_11

no abstracts in English

A Sensitive method for Sr-90 analysis by accelerator mass spectrometry

Sasa, Kimikazu*; Honda, Maki; Hosoya, Seiji*; Takahashi, Tsutomu*; Takano, Kenta*; Ochiai, Yuta*; Sakaguchi, Aya*; Kurita, Saori*; Satou, Yukihiko; Sueki, Keisuke*

Journal of Nuclear Science and Technology, 58(1), p.72 - 79, 2021/01

https://doi.org/10.1080/00223131.2020.1801530

Visualising spatio-temporal distributions of assimilated carbon translocation and release in root systems of leguminous plants

Yin, Y.-G.*; Suzui, Nobuo*; Kurita, Keisuke; Miyoshi, Yuta*; Unno, Yusuke*; Fujimaki, Shu*; Nakamura, Takuji*; Shinano, Takuro*; Kawachi, Naoki*

Scientific Reports (Internet), 10, p.8446_1 - 8446_11, 2020/06

https://doi.org/10.1038/s41598-020-65668-9

The release of rhizodeposits differs depending on the root position and is closely related to the assimilated carbon (C) supply. Therefore, quantifying the C partitioning over a short period may provide crucial information for clarifying root-soil carbon metabolism. A non-invasive method for visualising the translocation of recently assimilated C into the root system inside the rhizobox was established using CO labelling and the positron-emitting tracer imaging system. The spatial distribution of recent C-photoassimilates translocated and released in the root system and soil were visualised for white lupin () and soybean (). Our method enabled the quantification of the spatial C allocations in roots and soil, which may help to elucidate the relationship between C metabolism and nutrient cycling at specific locations of the root-soil system in response to environmental conditions over relatively short periods.

Transient ionization of the mesosphere during auroral breakup; Arase satellite and ground-based conjugate observations at Syowa Station

Kataoka, Ryuho*; Nishiyama, Takanori*; Tanaka, Yoshimasa*; Kadokura, Akira*; Uchida, Herbert Akihito*; Ebihara, Yusuke*; Ejiri, Mitsumu*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Sato, Kaoru*; et al.

Earth, Planets and Space (Internet), 71, p.9_1 - 9_10, 2019/01

https://doi.org/10.1186/s40623-019-0989-7

Transient ionization of the mesosphere was detected at around 65 km altitude during the isolated auroral expansion occurred at 2221-2226 UT on June 30, 2017. A general-purpose Monte Carlo particle transport code PHITS suggested that significant ionization is possible in the middle atmosphere due to auroral X-rays from the auroral electrons of 10 keV.

Critical beta analyses of low aspect ratio tokamak

Kurita, Genichi; Aiba, Nobuyuki; Tobita, Kenji; Nishio, Satoshi; Nagashima, Keisuke

no journal, , 

We obtain the critical beta for the up-down symmetric double-null equilibria against the position of conformal conducting wall in two cases; one is fixed plasma current profile case and another is varied plasma current profile case taking a bootstrap current into account. To obtain normalized beta value, bN=4.3, assumed in Slim-CS tokamak, we must put the conducting wall at r=1.2a and r=1.34a, where a is the plasma minor radius, for former and latter cases, respectively. The advantage of latter case comes from the higher minimum safety factor value due to larger plasma bootstrap current derived by the increased plasma pressure. If we consider the effect of edge pedestal plasma pressure, the critical beta can be increased. In this study, only the n=1 mode, which is considered to be most dangerous one, is investigated.

Systematic evaluation of cultivation using plant radiotracer imaging techniques; For establishment of "Nuclear Agriculture"

Fujimaki, Shu; Kawachi, Naoki; Suzui, Nobuo; Ishii, Satomi; Yin, Y.-G.; Kurita, Keisuke

no journal, , 

no abstracts in English