Kawaguchi, Munemichi; Uno, Masayoshi*
Journal of Crystal Growth, 585, p.126590_1 - 126590_7, 2022/05
Phase-field mobility, , and crystal growth rates in crystallization of 11 oxides or mixed oxides in undercooled silicates, SiO and GeO liquids were calculated with a simple phase-field model (PFM), and material dependence of the was discussed. Ratios between experimental crystal growth rates and the PFM simulation with were confirmed to be proportional to a power of on the solid/liquid interface process during the crystal growth in a log-log plot. We determined that parameters, and , of the were to mJs and to , which were unique for the materials. It was confirmed that our PFM simulation with the determined reproduced quantitively the experimental crystal growth rates. The has a proportional relationship with the diffusion coefficient of a cation molar mass average per unit an oxygen molar mass at in a log-log graph. The depends on the sum of the cation molar mass per the oxygen molar mass, , in a compound. In , the decreases with the cation molar mass increasing. The assumed cause is that the B represents the degree of the temperature dependence of the . Since the cation molar mass is proportional to an inertial resistance of the cation transfer, the decreases with inverse of the cation molar mass. In crystallization of the silicates of heavy cation in , the saturates at approximately 0.67, which leads to .
Yuguchi, Takashi*; Yamazaki, Hayato*; Ishibashi, Kozue*; Sakata, Shuhei*; Yokoyama, Tatsunori; Suzuki, Satoshi*; Ogita, Yasuhiro; Sando, Kazusa*; Imura, Takumi*; Ono, Takeshi*
Journal of Asian Earth Sciences, 226, p.105075_1 - 105075_9, 2022/04
Simultaneous determination of the U-Pb age of zircon and concentration of titanium in a single analysis spot, using inductively coupled plasma mass spectrometry with laser ablation sample introduction, produces paired age and temperature data of zircon crystallisation, potentially revealing time-temperature () histories for evolved magma. The Kurobegawa granite, central Japan, contains abundant mafic magmatic enclaves (MMEs). We applied this method to evaluate MMEs and their host (enclosing) granites. Cooling behaviour common to both MMEs and host rocks was found between 1.5 and 0.5 Ma. Rapid cooling from the zircon crystallisation temperature to the closure temperature of biotite K-Ar system was within 1 million year. Combining the obtained paths of MMEs and host rocks with petrological information can provide insights into magma chamber processes. This suggests that MME flotation, migration, and spread through the magma chamber ceased at 1.5-0.5 Ma, indicating the emplacement age of the Kurobegawa granitic pluton, as no large-scale reheating episodes have occurred since then.
Haga, Yoshinori; Opletal, P.; Tokiwa, Yoshifumi; Yamamoto, Etsuji; Tokunaga, Yo; Kambe, Shinsaku; Sakai, Hironori
Journal of Physics; Condensed Matter, 34(17), p.175601_1 - 175601_7, 2022/04
Tachi, Yukio; Ito, Tsuyoshi*; Gylling, B.*
Water Resources Research, 57(11), 20 Pages, 2021/11
This paper focuses on the scaling approach for sorption and diffusion parameters from laboratory to in-situ conditions using the dataset of LTDE-SD experiment performed at the sp HRL. The near-surface heterogeneities at both fracture surface and rock matrix could be evaluated by conceptual model with high porosity and diffusivity, and sorption capacity, and their gradual change at the near-surface zones. The modelling results for non-sorbing Cl-36 and weak-sorbing Na-22 could validate the model concept and the parameter estimation of porosity and diffusivity, by considering the disturbed zone of 5 mm thickness with gradual parameter changes. The De values of these cationic and anionic tracers showed typical cation excess and anion exclusion effects. The modelling results for high sorbing tracers (Cs-137, Ra-226, Ni-63 and Np-237) with different sorption mechanism could confirm the validity of the scaling approaches of Kd values as a function of particle size and their relation to the near-surface disturbances.
Mri, A.*; Mazurek, M.*; Ota, Kunio; Siitari-Kauppi, M.*; Eichinger, F.*; Leuenberger, M.*
Minerals (Internet), 11(10), p.1072_1 - 1072_17, 2021/10
Fichter, S.*; Radoske, T.*; Ikeda, Atsushi
Acta Crystallographica Section E; Crystallographic Communications (Internet), 77(8), p.847 - 852, 2021/08
Liss, K.-D.*; Harjo, S.; Kawasaki, Takuro; Aizawa, Kazuya; Xu, P. G.
Journal of Alloys and Compounds, 869, p.159232_1 - 159232_9, 2021/07
Sakurai, Yosuke*; Sato, Hirotaka*; Adachi, Nozomu*; Morooka, Satoshi; Todaka, Yoshikazu*; Kamiyama, Takashi*
Applied Sciences (Internet), 11(11), p.5219_1 - 5219_17, 2021/06
Sato, Yoshiki*; Honda, Fuminori*; Maurya, A.*; Shimizu, Yusei*; Nakamura, Ai*; Homma, Yoshiya*; Li, D.*; Haga, Yoshinori; Aoki, Dai*
Physical Review Materials (Internet), 5(3), p.034411_1 - 034411_9, 2021/03
Tsuda, Shuichi; Tanigaki, Minoru*; Yoshida, Tadayoshi; Okumura, Ryo*; Saito, Kimiaki
Radiation Protection Dosimetry, 193(3-4), p.228 - 236, 2021/03
Environmental dose rate monitoring has been performed with various scintillation detectors since the Fukushima Dai-ichi Nuclear Power Plant accident. Gamma-rays from caesium isotopes deposited in soil enter radiation detectors in any direction, but directional dependence of the detectors used for dose rate measurements are not always uniform and the dose rates vary even if measurement takes place at the same place. To investigate the influence of crystal configurations on dose rate, dose rate measurements using several scintillation detectors with different crystal configurations were conducted. By measuring pulse height spectra and multiplying them with spectrum - dose conversion operators (G(E) function), dose rates were deduced and compared. It was found that the dose rates varied within approximately 25% among six detectors. To reduce the differences, the dose rate using G(E) functions determined in rotational geometry were obtained and applied instead. The revised dose rates agreed with one another within uncertainties, but this was not the case of scintillation detector with flat crystal shape, and it means this method could not compensate its strong directional dependence. These experimental results reveal that detectors with superior directional characteristics should be used for environmental dose rate measurement since the compensation of directional dependence using a G(E) function determined in rotational geometry is not always available.
Kawaguchi, Munemichi; Uno, Masayoshi*
Journal of the Ceramic Society of Japan, 128(10), p.832 - 838, 2020/10
This study developed phase-field method (PFM) technique in oxide melt system by using a new mobility coefficient (). The crystal growth rates () obtained by the PFM calculation with the constant were comparable to the thermodynamic driving force in normal growth model. The temperature dependence of the was determined from the experimental crystal growth rates and the . Using the determined , the crystal growth rates () in alkali disilicate glasses, LiO-2SiO, NaO-2SiO and KO-2SiO were simulated. The temperature dependence of the was qualitatively and quantitatively so similar that the PFM calculation results demonstrated the validity of the . Especially, the obtained by the PFM calculation appeared the rapid increase just below the thermodynamic melting point () and the steep peak at around -100 K. Additionally, as the temperature decreased, the apparently approached zero ms, which is limited by the representing the interface jump process. Furthermore, we implemented the PFM calculation for the variation of the parameter in the . As the increased from zero to two, the peak of the became steeper and the peak temperature of the shifted to the high temperature side. The parameters and in the increased exponentially and decreased linearly as the atomic number of the alkali metal increased due to the ionic potential, respectively. This calculation revealed that the and in the were close and reasonable for each other.
Miradji, F.; Suzuki, Chikashi; Nakajima, Kunihisa; Osaka, Masahiko
Journal of Physics and Chemistry of Solids, 136, p.109168_1 - 109168_9, 2020/01
Ichikawa, Yasuaki*; Kimoto, Kazushi*; Matsui, Hiroya
JAEA-Research 2019-005, 32 Pages, 2019/10
It is important to evaluate the mechanical stability around the geological repository for high-level radioactive waste, during not only the design, construction and operation phases, but also the post-closure period over several millennia. The rock mass around the tunnels could be deformed in response to time dependent behaviors such as creep and stress relaxation. Therefore, this study has started as a joint research with Okayama University from 2016. This report summarize the results of the joint research performed in fiscal year 2017 and 2018. Based on the research results obtained in fiscal year 2016, automatic measurement system was developed, which can collect very large data on surface elastic wave propagation in a short time, also the applicability of various kinds of parameters derived from measured elastic wave data was examined.
Toguri, Satohito*; Yahagi, Ryoji*; Okihara, Mitsunobu*; Takeuchi, Nobumitsu*; Kurosaki, Hiromi*; Matsui, Hiroya
JAEA-Technology 2018-017, 161 Pages, 2019/03
The Japan Atomic Energy Agency has been conducting research on three critical issues for development of: engineering techniques for underground construction, modelling techniques of mass transfer and tunnel backfilling methods at the Mizunami Underground Research Laboratory on the basis of Medium to Long-Term Plan of Japan Atomic Energy Agency. This report describes the overall plan of in-situ test to backfill a part of Mizunami Underground Research Laboratory, which is planned for "development of tunnel backfilling method".
Yano, Naomine*; Yamada, Taro*; Hosoya, Takaaki*; Ohara, Takashi; Tanaka, Ichiro*; Niimura, Nobuo*; Kusaka, Katsuhiro*
Acta Crystallographica Section D; Structural Biology (Internet), 74(11), p.1041 - 1052, 2018/11
Motoyama, Gaku*; Haga, Yoshinori; Yamaguchi, Akira*; Kawasaki, Ikuto*; Sumiyama, Akihiko*; Yamamura, Tomoo*
Progress in Nuclear Science and Technology (Internet), 5, p.157 - 160, 2018/11
Hamon, 28(1), p.26 - 28, 2018/02
We briefly introduce the pedigree of the backscattering neutron spectrometer and the specification of DNA; a time-of-flight (TOF) type near-backscattering spectrometer (n-BSS), with Si crystal analyzers which was constructed at the Materials and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC).
Matsumoto, Yuji*; Haga, Yoshinori; Tateiwa, Naoyuki; Yamamoto, Etsuji; Fisk, Z.*
Journal of the Physical Society of Japan, 87(2), p.024706_1 - 024706_4, 2018/02
Fukui, Katsunori*; Hashiba, Kimihiro*; Matsui, Hiroya
JAEA-Research 2017-010, 61 Pages, 2017/11
JAEA has started this study as a collaboration study with Tokyo University from 2016. In the fiscal year of 2016, creep testing on Tage tuff was continuously conducted. Existing theory of rate process and stochastic process was modified to be applied to evaluate effects of water, and then the modified theory was validated based on the results of strength and creep tests performed under dry and wet conditions. Furthermore, effects of water contents on stress-strain curves were examined by uniaxial compression testing under various water content conditions.
Kimoto, Kazushi*; Ichikawa, Yasuaki*; Matsui, Hiroya
JAEA-Research 2017-009, 18 Pages, 2017/11
JAEA has started this study as joint research with Okayama University from 2016. In fiscal year 2016, several kinds of elastic wave velocity were measured using ultra sonic sensors and laser Doppler vibrometer to evaluate the anisotropy of different elastic wave in granite. The velocity measurements were carried out focused on transmitted wave and surface wave. The results showed that strong anisotropy was observed in transmitted P- wave velocity while weak anisotropy was observed in transmitted S-wave and group velocity estimated by surface velocity measurement. In addition, data obtained from surface velocity measurement was partitioned into transmitted and reflected waves and analyzed them in detail. It resulted that elastic wave due to mineral particles consist of granite was dispersed; however, significant dispersion was only observed at specific location.