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Kaneko, Fumitoshi*; Kawaguchi, Tatsuya*; Radulescu, A.*; Iwase, Hiroki*; Morikawa, Toshiaki*; Takata, Shinichi; Nishiura, Masayoshi*; Hou, Z.*
Review of Scientific Instruments, 90(9), p.093906_1 - 093906_6, 2019/09
Times Cited Count:3 Percentile:17.23(Instruments & Instrumentation)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
Times Cited Count:182 Percentile:99.31(Multidisciplinary Sciences)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.
Sugita, Yutaka; Kawaguchi, Tatsuya; Hatanaka, Koichiro; Shimbo, Hiroshi*; Yamamura, Masato*; Kobayashi, Yuichi*; Fujisawa, Yasuo*; Kobayashi, Ichiro*; Yabuki, Nobuyoshi*
Proceedings of 16th International Conference on Computing in Civil and Building Engineering (ICCCBE 2016) (Internet), p.1173 - 1182, 2016/07
This paper presents status of development of the iSRE (integrated system for repository engineering) as a design supporting system that enables rational designing of a geological disposal repository. The complimentary technique of construction information modeling/management (CIM) has been employed for the development of iSRE. CIM uses a shared three dimensional (3D) model of associated data through common data models. The contents of this paper are the goal of the development, design requirements and required functions, the basic structure of iSRE. The main databases of the iSRE could then be designed with an interface to coordinate with external systems and other databases. Some of the databases and the interfaces were trialed and a data model was then built. A scenario of iSRE operation was also created and the applicability of iSRE using a data model was also examined. Thanks to the use of the existing software, the development process could be conducted while solving problems for realistic test cases. The prospect of the development of the iSRE for geological disposal projects was realized and the iSRE was confirmed as being a useful tool for designing a repository.
Nakanishi, Tatsuro; Kawaguchi, Masanao; Tsuda, Hidenori; Uyama, Masao*; Tanaka, Tatsuya*
Doboku Gakkai Heisei-23-Nendo Zenkoku Taikai Dai-66-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.71 - 72, 2011/09
no abstracts in English
Kira, Erika*; Tateno, Kumiko*; Miura, Kinichiro*; Haga, Tatsuya*; Hayashi, Masaki*; Harada, Kyuya*; Sato, Shusei*; Tabata, Satoshi*; Shikazono, Naoya; Tanaka, Atsushi; et al.
Plant Journal, 44(3), p.505 - 515, 2005/11
Times Cited Count:90 Percentile:86.56(Plant Sciences)no abstracts in English
Imai, Suguru*; Taguchi, Kenji*; Kashiwa, Tatsuya*; Kawaguchi, Koichi; Segawa, Tomoomi
no journal, ,
In the nuclear cycle system, reprocessing solutions (plutonium and uranium mixed nitrate solution) produced from spent nuclear fuel is converted to Mixed Oxide (MOX) by a microwave heating (MH) method in Japan. The electric constant of the reprocessing solution is varied by its phase state on heating and denitration reaction and affects the microwave heating property. It is important to understand the property of the microwave heating for improving the efficiency. Therefore the temperature distribution of the solid state of the reprocessing solution is investigated by the electromagnetic analysis and thermal analysis using FDTD method and thermal analysis method. As a result, the absorbed power of the solid-state Pu-U mixed nitrate are concentrated at upper surface and periphery, and generated heat flows to below.
Kawaguchi, Tatsuya*; Saegusa, Hiromitsu; Niwa, Masakazu; Shimada, Koji; Yasue, Kenichi; Kurosawa, Hideki; Kamataki, Takanobu*; Tosaka, Hiroyuki*
no journal, ,
no abstracts in English
Sugita, Yutaka; Chijiwa, Tatsunori; Honda, Akira; Shibata, Masahiro; Kawaguchi, Tatsuya; Maekawa, Keisuke; Hatanaka, Koichiro; Ebashi, Takeshi; Semba, Takeshi; Makino, Hitoshi
no journal, ,
This paper reports on the development of ISRE (the Integrated System for Repository Engineering), as a knowledge management tool on repository design and engineering technology, which manages and inherits the information and knowledge of each phase of the disposal project of radioactive waste lasting around 100 years, and which also enables reasonable design of the repository by using accumulated and integrated information. The content of this paper is the conceptual design of the ISRE utilizing CIM (Computer Information Modeling) technology.
Kobayashi, Yuichi*; Fujisawa, Yasuo*; Yoshino, Hiroyuki*; Sugita, Yutaka; Kawaguchi, Tatsuya; Hatanaka, Koichiro; Shibata, Masahiro; Yamamura, Masato*; Kamisakoda, Kazuto*; Shimbo, Hiroshi*; et al.
no journal, ,
This paper reports on the development of ISRE (the Integrated System for Repository Engineering), as a knowledge management tool on repository design and engineering technology, which manages and inherits the information and knowledge of each phase of the disposal project of radioactive waste lasting around 100 years, and which also enables reasonable design of the repository by using accumulated and integrated information. The content of this paper is a formulation of the integrated model for the ISRE and management method of the attribute information associated with the data model.
Shimbo, Hiroshi*; Yamamura, Masato*; Kamisakoda, Kazuto*; Sugita, Yutaka; Kawaguchi, Tatsuya; Hatanaka, Koichiro; Shibata, Masahiro; Fujisawa, Yasuo*; Yoshino, Hiroyuki*; Kobayashi, Yuichi*; et al.
no journal, ,
This paper reports on the development of ISRE (the Integrated System for Repository Engineering), as a knowledge management tool on repository design and engineering technology, which manages and inherits the information and knowledge of each phase of the disposal project of radioactive waste lasting around 100 years, and which also enables reasonable design of the repository by using accumulated and integrated information. The content of this paper is the utilization of the ISRE in the disposal project.
Segawa, Tomoomi; Tanigawa, Masafumi; Kato, Yoshiyuki; Kawaguchi, Koichi; Ishii, Katsunori; Suzuki, Masahiro; Kitazawa, Toshihide*; Taguchi, Kenji*; Kashiwa, Tatsuya*
no journal, ,
For the purpose of improving the microwave heating denitration technology, the denitration characteristics of cobalt nitrate aqueous solutions as a simulated materials were analyzed and evaluated by using the microwave heating equipment whichi was controlled to circular polarized wave. Numerical simulation confirmed that the circular polarized wave controlled microwave irradiation uniformed the absorbed power distribution in the circumferential direction. Moreover, it was confirmed that the denitration proceeded uniformly even in the radial direction by the microwave heating denitration experiments of cobalt nitrate aqueous solutions. From these results, it was revealed that favorable heating and denitration characteristics can be obtained by the circularly polarized wave controlled microwave heating equipment.
Nohara, Tsuyoshi; Kusano, Tomohiro; Kawaguchi, Tatsuya*; Kamataki, Takanobu*
no journal, ,
Coseismic remarkable decreases of water level are observed repeatedly in the same point with the distant earthquakes. Coseismic water level changes in the focal regions with some large earthquakes tend to increase in discharge area and decrease in recharge area. These features of coseismic changes indicate that the effect of coseismic increases of permeability have a large role in the change of the regional groundwater flow system.
Segawa, Tomoomi; Tanigawa, Masafumi; Kato, Yoshiyuki; Kawaguchi, Koichi; Ishii, Katsunori; Suzuki, Masahiro; Kitazawa, Toshihide*; Kashiwa, Tatsuya*
no journal, ,
To improve the handling and sinterability of raw powder of a uranium and plutonium mixed oxide produced in the reprocessing process of spent fuels, the microwave heating equipment has been developed considering the microwave property of linear polarization and circularly polarization that contribute to the uniformization of the microwave heating denitration by JAEA. The electromagnetic field simulation analysis was carried out by the Finite-Difference Time-Domain method, and the experimental results were evaluated. An analysis model was developed based on the obtained physical property data which were measured by the cylindrical cavity resonator method. The liquid phase state, microwave was concentrated on the upper surface and bottom surface due to the high loss of the cobalt nitrate aqueous solution, while in the solid phase state, microwave energy was absorbed inside. The absorption electric power distribution became uniform in the circumferential direction.
Kawaguchi, Tatsuya*; Kusano, Tomohiro; Nohara, Tsuyoshi; Yasue, Kenichi; Kamataki, Takanobu*
no journal, ,
In this study, the ground water analysis that assumes presence of salt water and/or high conductivity fault zone has been taken place in northern Awaji Island using numerical simulation. The author has accumulated data from the case with boundary condition and without it. The result shows that in the case of considering presence of salt water, both hydraulic total head and flux of surface flow has increased. A part of the point where large amount of discharge is shown by the analysis is corresponding to the point where spring water is confirmed by the field investigation. A part of the analytical result with continuous high conductivity zone is assumed discord with the result of the field investigation.