Spontaneous topological Hall effect induced by non-coplanar antiferromagnetic order in intercalated van der Waals materials

Takagi, Hirotaka*; Takagi, Rina*; Minami, Susumu*; Nomoto, Takuya*; Oishi, Kazuki*; Suzuki, Michito*; Yanagi, Yuki*; Hirayama, Motoaki*; Khanh, N.*; Karube, Kosuke*; et al.

Nature Physics, 19(7), p.961 - 968, 2023/07

https://doi.org/10.1038/s41567-023-02017-3

U-RANS simulation of triple elbow flow with a 1/7 scale experimental loop simulating cold-leg piping of an advanced loop-type sodium-cooled fast reactor

Yamano, Hidemasa; Tanaka, Masaaki; Ebara, Shinji*; Hashizume, Hidetoshi*

Proceedings of 27th International Symposium on Transport Phenomena (ISTP-27) (USB Flash Drive), 8 Pages, 2016/09

In this study, Unsteady Reynolds Averaged Navier-Stokes equation (U-RANS) approach with the Reynolds Stress Model using commercial CFD code has been applied to the flow through triple short-elbows under a high Re (1.010). This numerical simulation has utilized a 1/7 scaled water experiment of the advanced SFR cold-leg piping in order to investigate the flow structure in a three-dimensionally connected triple elbows. As a result, applicability of the U-RANS numerical simulation method was confirmed by comparison between the numerical and experimental results under Re = 1.010 condition. The simulation has also shown that flow fields in the 1st elbow was different from that in the 2nd elbow and pressure fluctuation in the 2nd elbow was slightly larger than that in the 1st elbow because of the presence of their large vortex flow structure. This large vortex was generated due to a short distance between two elbows. On the other hand, the flow structure in the 3rd elbow was similar to that in the 1st elbow because the swirling flow formed in the 2nd elbow was alleviated in the 3rd elbow inlet which was located long way away from the 2nd elbow.

Development of electromagnetic non-destructive testing method for the inspection of heat exchanger tubes of Japan Sodium-cooled Fast Reactor, 2; Detection of flaws on the inner surface using electromagnetic waves

Sasaki, Kota*; Yusa, Noritaka*; Wakai, Takashi; Hashizume, Hidetoshi*

Electromagnetic Nondestructive Evaluation (XVIII), p.244 - 251, 2015/06

https://doi.org/10.3233/978-1-61499-509-8-244

U-RANS simulation of elbow flow with a 1/7 scale experimental loop simulating JSFR cold-leg piping

Yamano, Hidemasa; Kaneko, Tetsuya*; Aizawa, Kosuke; Tanaka, Masaaki; Ebara, Shinji*; Hashizume, Hidetoshi*

Proceedings of 9th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-9) (CD-ROM), 10 Pages, 2014/11

In this study, Unsteady Reynolds Averaged Navier-Stokes equations (U-RANS) approach with the Reynolds Stress Model using a commercial computational fluid dynamics code has been applied to the flow through single and double short-elbows under a high Reynolds number condition (1.010). This numerical simulation has utilized a 1/7 scaled water experiment simulating the JSFR cold-leg piping in order to investigate the flow pattern in a three-dimensionally connected double elbow. As a result, validity and applicability of the U-RANS numerical simulation method were confirmed by comparison between the numerical and experimental results. The simulation has also shown that unsteady flow fields including vortex structures in the 1st elbow were very different from that in the 2nd elbow. This is because horseshoe vortexes generated in the 1st elbow downstream enter sideways the 2nd elbow. In addition, the simulation has indicated that the influence of distance between two elbows in the double elbow flow addressed in this paper was small.

Evaluation of the applicability of a new quantitative rock mass classification method at the Mizunami Underground Research Laboratory

Kuji, Masayoshi*; Asai, Hideaki*; Hashizume, Shigeru; Horiuchi, Yasuharu; Sato, Toshinori; Matsui, Hiroya

JAEA-Technology 2013-022, 72 Pages, 2013/10

JAEA-Technology-2013-022.pdf:5.3MB

Rock mass classifications are used for design and construction of underground structures. However, the classification methods commonly used in Japan are qualitative and inadequate for estimating the actual mechanical properties of a rock mass based on site specific geological features. Considering the design, construction and safe operation of large underground facilities, an important requirement is to utilize a rock mass classification method that can estimate site specific rock mechanical properties based on surface-based investigations and geological observations during excavation. For this study, a new quantitative rock mass classification method based on JGS standard was proposed and applied to the sedimentary formations and the granite at MIU. The results were compared with the rock mass classification system developed by CRIEPI and commonly used in JAPAN. Then the applicability of the new rock mass classification could be evaluated.

Enhancement of microwave nondestructive testing method for the inspection of pipes by optimizing the microwave probe profile

Sasaki, Kota*; Yusa, Noritaka*; Wakai, Takashi; Hashizume, Hidetoshi*

Hozengaku, 12(1), p.81 - 86, 2013/04

This study reports the development of a new microwave probe for the nondestructive testing of a pipe. Three-dimensional finite element simulations are carried out to optimize the profile of a microwave probe, whose results show that a probe with elliptic profile enables smaller reflection at the probes as well as much better single-mode propagation inside the pipe than conventional ones. Experimental validations are carried out using a straight brass pipe with an inner diameter of 39 mm and a total length of 2 m. The results of the experiments clearly demonstrate that the new microwave probe provides clearer signals due to simulated rectangular wall thinning.

Effects of separation vortices on pressure fluctuation of complex turbulent flow in a dual elbow with small curvature radius in a three-dimensional layout

Ebara, Shinji*; Konno, Hiroaki*; Hashizume, Hidetoshi*; Kaneko, Tetsuya; Yamano, Hidemasa

Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 8 Pages, 2012/12

In this study, the characteristics of pressure fluctuation in a dual elbow piping simulating the cold-leg piping of the JSFR was elucidated by conducting a pressure measurement test using a scale model. As a result of the experiment, it was clarified that the pressure fluctuation characteristics of the dual elbow flow was very similar to that of the single elbow flow in and near the first elbow.

Emergent phenomena in perovskite-type manganites

Taguchi, Yasujiro*; Sakai, Hideaki*; Okuyama, Daisuke*; Ishiwata, Shintaro*; Fujioka, Jun*; Fukuda, Tatsuo; Hashizume, Daisuke*; Kagawa, Fumitaka*; Takahashi, Yoichiro*; Shimano, Ryo*; et al.

Physica B; Condensed Matter, 407(11), p.1685 - 1688, 2012/06

https://doi.org/10.1016/j.physb.2012.01.006

PIV measurements of a complex turbulent flow in a short elbow piping under a high Reynolds number condition

Takamura, Hiroyuki*; Konno, Hiroaki*; Ebara, Shinji*; Hashizume, Hidetoshi*; Aizawa, Kosuke; Yamano, Hidemasa

Proceedings of 9th International Symposium on Particle Image Velocimetry (PIV '11) (USB Flash Drive), 6 Pages, 2011/07

Systematic study for the shell effect in the fission fragment mass distribution reptured from neutron rich nuclei

Ota, Masahisa*; Tatsuda, Sayuki*; Yamamoto, Kazuyuki*; Asano, Tomomasa*; Wada, Takahiro*; Hashizume, Kazuaki*; Sumiyoshi, Kosuke*; Otsuki, Kaori*; Kajino, Toshitaka*; Koura, Hiroyuki; et al.

Nuclear Physics A, 805(2), p.558 - 560, 2008/02

The data base for the fission fragment mass distribution used in the r-process network calculation is constructed. The differences appeared in the final element abundance calculated with and without fission process are demonstrated and the mass region modified by the fission products is presented.