Devil's staircase transition of the electronic structures in CeSb

Kuroda, Kenta*; Arai, Yosuke*; Rezaei, N.*; Kunisada, So*; Sakuragi, Shunsuke*; Alaei, M.*; Kinoshita, Yuto*; Bareille, C.*; Noguchi, Ryo*; Nakayama, Mitsuhiro*; et al.

Nature Communications (Internet), 11, p.2888_1 - 2888_9, 2020/06

https://doi.org/10.1038/s41467-020-16707-6

Colossal barocaloric effects in plastic crystals

Li, B.*; Kawakita, Yukinobu; Kawamura, Seiko; Sugahara, Takeshi*; Wang, H.*; Wang, J.*; Chen, Y.*; Kawaguchi, Saori*; Kawaguchi, Shogo*; Ohara, Koji*; et al.

Nature, 567(7749), p.506 - 510, 2019/03

https://doi.org/10.1038/s41586-019-1042-5

Refrigeration is of vital importance for modern society for example, for food storage and air conditioning- and 25 to 30% of the world's electricity is consumed for refrigeration. Current refrigeration technology mostly involves the conventional vapour compression cycle, but the materials used in this technology are of growing environmental concern because of their large global warming potential. As a promising alternative, refrigeration technologies based on solid-state caloric effects have been attracting attention in recent decades. However, their application is restricted by the limited performance of current caloric materials, owing to small isothermal entropy changes and large driving magnetic fields. Here we report colossal barocaloric effects (CBCEs) (barocaloric effects are cooling effects of pressure-induced phase transitions) in a class of disordered solids called plastic crystals. The obtained entropy changes in a representative plastic crystal, neopentylglycol, are about 389 joules per kilogram per kelvin near room temperature. Pressure-dependent neutron scattering measurements reveal that CBCEs in plastic crystals can be attributed to the combination of extensive molecular orientational disorder, giant compressibility and highly anharmonic lattice dynamics of these materials. Our study establishes the microscopic mechanism of CBCEs in plastic crystals and paves the way to next-generation solid-state refrigeration technologies.

Development of optical fiber detector for measurement of fast neutron

Yagi, Takahiro*; Misawa, Tsuyoshi*; Pyeon, C. H.*; Unesaki, Hironobu*; Shiroya, Seiji*; Kawaguchi, Shinichi*; Okajima, Shigeaki; Tani, Kazuhiro*

Proceedings of International Conference on the Physics of Reactors, Nuclear Power; A Sustainable Resource (PHYSOR 2008) (CD-ROM), 8 Pages, 2008/09

In order to insert a neutron detector in a narrow space such as a gap of between fuel plates and measure the fast neutrons in real time, a neutron detector with an optical fiber has been developed. This detector consists of an optical fiber whose tip is covered with mixture of neutron converter material and scintillator such as ZnS(Ag). The detector for fast neutrons uses ThO as converter material because Th makes fission reaction with fast neutrons. The place where Th can be uses is limited by regulations because Th is nuclear fuel material. The purpose of this research is to develop a new optical fiber detector to measure fast neutrons without Th and to investigate the characteristic of the detector. These detectors were used to measure a D-T neutron generator and fast neutron flux distribution at Fast Critical Assembly. The results showed that the fast neutron flux distribution of the new optical fiber detector with ZnS(Ag) was the same as it of the activation method, and the detector are effective for measurement of fast neutrons.

The Microbe capture experiment in space; Fluorescence microscopic detection of microbes captured by aerogel

Sugino, Tomohiro*; Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Hasegawa, Sunao*; Hashimoto, Hirofumi*; Imai, Eiichi*; Okudaira, Kyoko*; Kawai, Hideyuki*; Tabata, Makoto*; et al.

no journal, , 

Capture and space exposure experiments of microorganisms on the ISS orbit proposed in "TANPOPO" mission

Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Sugino, Tomohiro*; Takahashi, Yuta*; Narumi, Issei; Nakagawa, Kazumichi*; Tabata, Makoto*; Kobayashi, Kensei*; Marumo, Katsumi*; et al.

no journal, , 

Tanpopo Working Group report; Space exposure of microbes and organic materials

Yokobori, Shinichi*; Kobayashi, Kensei*; Mita, Hajime*; Yabuta, Hikaru*; Nakagawa, Kazumichi*; Narumi, Issei; Hayashi, Nobuhiro*; Tomita, Kaori*; Kawaguchi, Yuko*; Shimizu, Yasuyuki*; et al.

no journal, , 

no abstracts in English

Current status and issues of low dose and low dose rate radiation risk estimation method; Current status and issues of dose assessment

Sakai, Kazuo*; Yamada, Yu*; Yoshida, Kazuo*; Yoshinaga, Shinji*; Sato, Kaoru; Ogata, Hiromitsu*; Iwasaki, Toshiharu*; Kudo, Shinichi*; Asada, Kyosei*; Kawaguchi, Isao*; et al.

no journal, , 

Task Group of Low dose and Low Dose Rate Radiation Risk Estimation Method in the Japan Health Physics Society presented the task group activity from April, 2016 to March, 2018. The presenter introduce the current status and issues of dose assessment (e.g. effects of anatomical characteristics of subjects, monitoring data, distribution of dose and dose rate in body on uncertainty of dose assessment).

Investigations and test plan for neptunium recovery in Tokai reprocessing plant

Nagaoka, Shinichi; Kawaguchi, Yoshihito

no journal, , 

In Tokai Reprocessing Plant (TRP), 5060% of Np is transferred to waste. To co-recover Pu-U-Np, the large ratio of Np transition to waste is problem. So we are investigating Np behavior with extraction cycles in TRP to obtain control technology for Pu-U-Np co-recovery. Now we present Np behavior in TRP and plan of research co-recovery of Pu-U-Np.

Microbe space exposure experiment at International Space Station (ISS) proposed in "Tanpopo" mission

Yokobori, Shinichi*; Yang, Y.*; Sugino, Tomohiro*; Kawaguchi, Yuko*; Fushimi, Hidehiko*; Narumi, Issei; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; Kawai, Hideyuki*; Kobayashi, Kensei*; et al.

no journal, , 

Microbe space exposure experiments at International Space Station (ISS) in the mission Tanpopo

Kawaguchi, Yuko*; Yang, Y.*; Kawashiri, Narutoshi*; Shiraishi, Keisuke*; Sugino, Tomohiro*; Takahashi, Yuta*; Tanigawa, Yoshiaki*; Narumi, Issei; Sato, Katsuya; Hashimoto, Hirofumi*; et al.

no journal, , 

http://www2.jpgu.org/meeting/2012/html5/PDF/B-AO01/BAO01-P09.pdf