Deformation mechanism of a strong and ductile maraging steel investigated using X-ray synchrotron diffraction

Li, H.*; Liu, Y.*; Zhao, W.*; Liu, B.*; Tominaga, Aki; Shobu, Takahisa; Wei, D.*

International Journal of Plasticity, 165, p.103612_1 - 103612_20, 2023/06

https://doi.org/10.1016/j.ijplas.2023.103612

In order to clarify the strength properties of Co-free maraging steel, tensile experiment using high energy synchrotron X-ray diffraction was performed. Diffraction profiles from the martensitic and austenitic phases were obtained, and their strength and width were observed to vary as loading. Analysis of the diffraction profiles showed that the content of martensite in the as-aged material decreased slowly at low stress levels and decreased rapidly at high stress levels. On the other hand, the austenite phase in the as-solution materials was significantly transformed the martensite phase as the stress increased. It was clarified to be responsible for their respective strength properties.

Odd and even modes of neutron spin resonance in the bilayer iron-based superconductor CaKFeAs

Xie, T.*; Wei, Y.*; Gong, D.*; Fennell, T.*; Stuhr, U.*; Kajimoto, Ryoichi; Ikeuchi, Kazuhiko*; Li, S.*; Hu, J.*; Luo, H.*

Physical Review Letters, 120(26), p.267003_1 - 267003_7, 2018/06

https://doi.org/10.1103/PhysRevLett.120.267003

ITER magnet systems; From qualification to full scale construction

Nakajima, Hideo; Hemmi, Tsutomu; Iguchi, Masahide; Nabara, Yoshihiro; Matsui, Kunihiro; Chida, Yutaka; Kajitani, Hideki; Takano, Katsutoshi; Isono, Takaaki; Koizumi, Norikiyo; et al.

Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 8 Pages, 2013/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2012/papers/578_ITR24.pdf

The ITER organization and 6 Domestic Agencies (DA) have been implementing the construction of ITER superconducting magnet systems. Four DAs have already started full scale construction of Toroidal Field (TF) coil conductors. The qualification of the radial plate manufacture has been completed, and JA and EU are ready for full scale construction. JA has qualified full manufacturing processes of the winding pack with a 1/3 prototype and made 2 full scale mock-ups of the basic segments of TF coil structure to optimize and industrialize the manufacturing process. Preparation and qualification of the full scale construction of the TF coil winding is underway by EU. Procurement of the manufacturing equipment is near completion and qualification of manufacturing processes has already started. The constructions of other components of the ITER magnet systems are also going well towards the main goal of the first plasma in 2020.

Performance of vanadium redox flow battery with a novel amphoteric ion exchange membrane synthesized by two-step grafting method

Qiu, J.*; Zhai, M.*; Chen, J.; Wang, Y.*; Peng, J.*; Xu, L.*; Li, J.*; Wei, G.*

Journal of Membrane Science, 342(1-2), p.215 - 220, 2009/10

https://doi.org/10.1016/j.memsci.2009.06.043

A novel ETFE-based amphoteric ion exchange membrane (AIEM) was prepared through a two-step radiation induced grafting technique. ETFE film was first grafted with styrene (St) (denoted as ETFE--PS), followed with a sulfonation treatment to obtain a cation exchange membrane (ETFE--PSSA). The ETFE--PSSA membrane was subsequently grafted with dimethylaminoethyl methacrylate (DMAEMA) and then protonated, resulting in an AIEM with both anionic and cationic groups. The obtained AIEM exhibited high ion exchange capacity (IEC) and conductivity, as well as significantly reduced permeability of vanadium ions. Vanadium redox flow battery (VRFB) assembled with the AIEM maintained an open circuit voltage (OCV) higher than 1.3V after placed for 300h, and exhibited higher columbic efficiency and energy efficiency than that with Nafion117 membrane.

A Hot test on minor actinides / lanthanides separation from HLLW using an R-BTP extraction resin

Wei, Y.*; Hoshi, Harutaka; Kumagai, Mikio*

Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/10

To separate the long-lived minor actinides (MA=Am, Cm) from high level liquid waste, we have been studying an advanced separation process by extraction chromatography. The process consists of two separation columns packed with CMPO (octyl(phenyl)-N,N-diisobutylcarbamoyl-methyl phosphine oxide) extraction resin for elemental group separation and a soft-donor named R-BTP (2,6-bis-(5,6-dialkyl-1,2,4-triazine-3-yl)pyridine) extraction resin for the isolation of MA from lanthanides (Ln), respectively. In this work, a hot test for the separation of MA from MA containing effluent from the irradiated MOX-fuel treatment process was carried out using a column packed with R-BTP extraction resin. It was found that a complete separation between MA and Ln was achieved. In addition, small amounts of U and Pu remained in the MA-Ln effluent could be effectively recovered together with the MA. The test results indicate that the proposed MA separation process is essentially feasible.

Separation of trivalent actinides from lanthanides by using R-BTP resins and stability of R-BTP resin

Hoshi, Harutaka*; Wei, Y.*; Kumagai, Mikio*; Asakura, Toshihide; Morita, Yasuji

Journal of Alloys and Compounds, 408-412, p.1274 - 1277, 2006/02

https://doi.org/10.1016/j.jallcom.2005.04.128

For the development of advanced aqueous reprocessing system, it is one of the most important subjects to separate minor trivalent actinides (MA = Am and Cm). Recently, extraction selectivity for MA(III) over Ln(III) has been found in some extractants containing soft donor, such as S or N, ligands. Kolarik et al. reported that a new N-donor ligand 2,6-bis(5,6-dialkyl-1,2,4-triazine-3-yl)-pyridine (R-BTP) shows high selectivity for MA (III) over Ln(III). The novel silica-based extraction resins were prepared by impregnating some R-BTP molecules into a macroreticular styrene-divinylbenzene copolymer which is immobilized in porous silica particles with a mean diameter of 50 m. Separation of simulated high level liquid waste solution containing Ln(III) and trace amount of Am(III) was studied. Am(III) was mutually separated from Ln(III) through a packed column with R-BTP impregnating resin, very high decontamination factor ( 10) for Am, and all the elements were recovered quantitatively.

Electrolytic reduction of Tc(VII) in nitric acid solution using glassy carbon electrode

Hoshi, Harutaka*; Wei, Y.*; Kumagai, Mikio*; Asakura, Toshihide; Morita, Yasuji

Journal of Radioanalytical and Nuclear Chemistry, 262(3), p.601 - 605, 2005/01

https://doi.org/10.1007/s10967-005-0482-6

Electroreduction of Tc(VII) in nitric acid solution using grassy carbon electrode was studied. The electroreduction was conducted at a constant potential -300 mV (vs. Ag/AgCl) with a potentiostat. It was found that difference of the Tc concentration in the solutions before and after the electrolysis was negligibly small. This means that there were almost no TcO or Tc deposited on the carbon fiber electrode during the electroreduction. Absorption spectra and distribution coefficients obtained by ion-exchange analysis indicated that Tc(VII) was reduced to Tc(IV).

Study on reduction of neptunium and uranium in nitric acid solution using flow type electrolytic cell, as a basic technique for advanced reprocessing process

Asakura, Toshihide; Uchiyama, Gunzo; Hoshi, Harutaka*; Wei, Y.*; Kumagai, Mikio*

Journal of Nuclear Science and Technology, 39(Suppl.3), p.340 - 342, 2002/11

http://www.tandfonline.com/doi/abs/10.1080/00223131.2002.10875478

no abstracts in English

Preparation of novel silica-based R-BTP extraction-resins and their application to trivalent actinides and lanthanides separation

Wei, Y.*; Hoshi, Harutaka*; Kumagai, Mikio*; Asakura, Toshihide; Uchiyama, Gunzo*

Journal of Nuclear Science and Technology, 39(Suppl.3), p.761 - 764, 2002/11

http://www.tandfonline.com/doi/abs/10.1080/00223131.2002.10875578

To separate long-lived minor actinides and specific fission products such as Zr and Mo from nitrate acidic high-level liquid waste, we studied an advanced partitioning process by extraction chromatography using minimal organic solvent and compact equipment. In this work, we synthesized several new type of nitrogen donor ligands, 2,6-bi-(5,6-dialkyl-1,2,4-triazine-3-yl)-pyridine (R-BTP) with different alkyl groups and prepared novel silica-based extraction-resins by impregnating these ligands into the SiO-P support with a diameter of 50 m. The adsorption performance of Am and Ln (III) from nitrate solution was investigated. It was found that the adsorption behavior depends strongly on the alkyl group in R-BTP. Bu-BTP/SiO-P and Hex-BTP/SiO-P showed high absorbability and selectivity for Am (III) over Ln (III). The separation factor is about 10 for Am/Ce and near 10 for Am/Eu-Gd, respectively. Effective Am (III) separation form Ln (III) by extraction chromatography using R-BTP/SiO-P extraction-resins is expected.

Development of separation system of Cs and Sr by silica-based macrocyclic compound adsorbents, 3; Adsorptive properties of TRU and Tc to Cs adsorbent and Sr adsorbent

Asakura, Toshihide; Morita, Yasuji; Wei, Y.*

no journal, , 

As a research on separation of heat producing FP, extraction chromatographic separation system of Cs and Sr by silica-based macrocyclic compound adsorbents is studied. Batch-wise adsorption experiments on TRU elements and Tc were performed using calix-crown adsorbent(for Cs) or crown ether adsorbent(for Sr). Pu (IV) was adsorbed to the calix-crown adsorbent from 4M nitric acid aqueous solution. Pu (IV) was also adsorbed to the crown-ether adsorbent from nitric acid with concentration of 2 M or higher. On the other hand, Np (V), Am and Tc were hardly adsorbed from 0.1-5 M nitric acid.