Effects of residual stress on hydrogen embrittlement of a stretch-formed tempered martensitic steel sheet

Nishimura, Hayato*; Hojo, Tomohiko*; Ajita, Saya*; Shibayama, Yuki*; Koyama, Motomichi*; Saito, Hiroyuki*; Shiro, Ayumi*; Yasuda, Ryo*; Shobu, Takahisa; Akiyama, Eiji*

ISIJ International, 61(4), p.1170 - 1178, 2021/04

https://doi.org/10.2355/isijinternational.ISIJINT-2020-492

Aquaculture of uranium in seawater by a fabric-adsorbent submerged system

Seko, Noriaki; Katakai, Akio; Hasegawa, Shin; Tamada, Masao; Kasai, Noboru; Takeda, Hayato*; Sugo, Takanobu; Saito, Kyoichi*

Nuclear Technology, 144(2), p.274 - 278, 2003/11

https://doi.org/10.13182/NT03-2

The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg-U/m in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific non-woven fabric was used as the adsorbent packed in an adsorption cage. We submerged adsorption cages, 16 m in cross-sectional area and 16 cm in height, in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The cage consisted of stacks of 52,000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the non-woven fabric was more than one kg in terms of yellow cake during a total submersion time of 240 days in the ocean.

Study on Na immobilization and leaching behavior of iron-phosphate type glass

Arai, Tsuyoshi*; Sato, Hayato*; Saito, Akihito*; Iwata, Masayuki*; Horiguchi, Kenichi; Sugaya, Atsushi

no journal, , 

no abstracts in English

Compact Raman lidar measurement of liquid and vapor phase water under the influence of ionizing radiation

Shiina, Tatsuo*; Chigira, Tomoyuki*; Saito, Hayato*; Manago, Naohiro*; Kuze, Hiroaki*; Hanyu, Toshinori; Kanayama, Fumihiko; Fukushima, Mineo

no journal, , 

Revealing the origin and ion-binding properties of dissolved organic matters in deep sedimentary groundwater

Saito, Takumi*; Nishi, Shusaku*; Sato, Hayato*; Miyakawa, Kazuya

no journal, , 

Dissolved organic matters (DOMs) play an important role for the fate of pollutants in surface and subsurface environments. For migration of radionuclides, the binding to DOMs modulates their aqueous speciation, reduce the adsorption on rock surface, and even enhance their transport, compared with non-sorbing tracers. The origin of DOMs in surface environments have been studied for decades and mechanistic models are proposed, which can describe ion-binding to major fractions DOMs (i.e. humic and fulvic fractions) over a wide range of environmental conditions. Nevertheless, our understanding on deep groundwater DOMs remains limited, and it is still disputable if model parameters calibrated for surface DOMs can be applied for their counterparts in deep subsurface environments. This study aims to reveal the origin of different DOM components in deep sedimentary groundwater and their ion-binding properties by fluorescence spectroscopy and high-resolution mass spectrometry. The results of both techniques are processed and correlated by multivariate analysis to find different DOM components and pursue their molecular characteristics. In the conference, we will present various molecular metrices describing the EEM components with the help of an advanced multivariate technique, which allows us to simultaneously process both the entire data sets of EEM and FT-ICR-MS data, consisting of the different data dimensions.

Molecular characterization of reactive deep underground dissolved organic matters for metal ion using high-resolution mass spectrometry

Sato, Hayato*; Toda, Kanako*; Beppu, Hikari*; Amano, Yuki; Miyakawa, Kazuya; Saito, Takumi*

no journal, , 

no abstracts in English