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Journal Articles

Pressure effect on isotope fractionation factor

Sano, Asami; Ito, Shoichi*; Suzumura, Akimasa*; Ueno, Yuichiro*; Yagi, Hikaru*; Inoue, Toru*; Kawazoe, Takaaki*

Koatsuryoku No Kagaku To Gijutsu, 30(2), p.85 - 94, 2020/10

Minerals and rocks exhibit various isotope compositions depending on their origins and histories. In interpreting their isotopic variations, the equilibrium isotope fractionation factor is a key because it depends on the environment parameters such as temperature. Recent studies have shown that the effect of pressure on the isotope fractionation, which was considered negligible compared to temperature, is significant under the conditions of the Earth's interior. In this article we review recent advances in experimental studies to determine the isotope fractionation of iron and hydrogen at high pressure over several GPa, discussing their issues and future perspectives.

Journal Articles

Overview of high-pressure neutron beamline, PLANET, and practical aspects of the experiments

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Funakoshi, Kenichi*; Abe, Jun*; Machida, Shinichi*; Okazaki, Nobuo*; Ouchi, Keiichi*; Inamura, Yasuhiro

Koatsuryoku No Kagaku To Gijutsu, 26(2), p.89 - 98, 2016/06

PLANET is a high-pressure neutron beamline constructed at pulsed-neutron source in Materials and Life Science Facility (MLF) in J-PARC. The six-axis multi-anvil press designed for time of flight (TOF) neutron diffraction experiments enables routine data collection at high pressures and high temperatures up to 10 GPa and 2000 K, respectively. To obtain clean data, the beamline is equipped with the incident slits and receiving collimators that eliminate parasitic scattering from the high-pressure cell. The high performance of the diffractometer for the resolution ($$Delta d/d$$ $$sim$$ 0.6%) and the accessible d-spacing range (0.2 - 8.4 ${AA}$) together with low-parasitic scattering characteristics enables precise structure determination of crystals and liquids under high pressure and temperature conditions.

Journal Articles

Miniature ceramic anvil cell mCAC for magnetic measurements under high pressure

Tateiwa, Naoyuki

Koatsuryoku No Kagaku To Gijutsu, 25(4), p.274 - 282, 2016/01

I will review miniature ceramic anvil cell mCAC for magnetic measurements under high pressure. Recently, the SQUID magnetometer has been used by researchers. Several types of high pressure cell have been developed for the magnetometer. In this paper, I will introduce our miniature ceramic anvil cell mCAC in details. Precise measurements can be possible with the mCAC since the background magnetization is smaller than those of other types of the cell. Finally, experimental data on the rare earth compound YbCu$$_2$$Si$$_2$$ will be shown. We detect pressure-induced ferromagnetic state in the compound above 10 GPa.

Journal Articles

Development of technique for electrical insulation of metallic gasket using anodic oxide coating

Osakabe, Toyotaka; Kato, Yoshihiro*; Honmoto, Satoru*; Kuwahara, Keitaro*

Koatsuryoku No Kagaku To Gijutsu, 25(1), p.57 - 63, 2015/03

In this article, we describe an unique technique for electrical insulation of metallic gasket to perform simultaneous measurements of electrical resistivity and neutron diffraction under high pressure. The anodic oxide coating was adopted as the insulation layer of the aluminum (JIS A2017) gasket used in the hybrid-anvil device for neutron diffraction. In the feasibility tests of the coated gaskets, maximum pressure of about 6 GPa was generated without electrical breakdown of the coating or disconnection of Au leads.

Journal Articles

Probabilistic properties of measurement for thickness of pipe with metal loss

Kaida, Takuyo*; Ishizaki, Yoichi*; Okajima, Satoshi

Atsuryoku Gijutsu, 52(2), p.53 - 63, 2014/04

Probabilistic approach for Fitness-For-Service (FFS) assessment of pressure equipment in petroleum and petrochemical plant helps to quantify the safety margin and rationalize the assessment. As for local metal loss assessment, several studies have been made on reliability analysis of the damaged equipment by use of limit state function, denoted by deterministic FFS model in published standard. Stochastic properties of random variables are needed in the reliability analysis. Remaining thickness of the pressure equipment is one of the important variables in limit state function for metal loss assessment. The thickness readings on a prescribed grid, which characterize the remaining thickness and size of the region of metal loss, might be varied by each inspector. There has been, however, no studies on stochastic properties of thickness readings for the local metal loss assessment. In this study, the stochastic properties of thickness readings were investigated by analyzing of the results of Round-Robin test. The cause of variation of thickness readings was clarified for the purpose of either protection of failure by pressure or that of leakage. The results of investigation indicated that standard deviation of thickness readings in the region of metal loss was more than that of thickness away from metal loss. Finally, the reliability of pressure equipment with local metal loss was analyzed using stochastic properties.

Journal Articles

Investigation of probability characteristic about thinning speed in actual plants and application for reliability analysis

Kurihara, Tomoyuki*; Kaida, Takuyo*; Okajima, Satoshi

Atsuryoku Gijutsu, 52(2), p.64 - 71, 2014/04

In Fitness-For-Service (FFS) assessment of pressure equipment, high reliability is needed in petroleum and petrochemical plant. Future Corrosion Allowance (FCA) is one of the most important factors in the metal loss assessment of FFS because it decides predicted value of the thickness during service periods. For the evaluation of FCA, the accurate corrosion rate from actual thinning data is needed and it is necessary to make a consideration of their variability of the thinning phenomena. In this study, the measured thickness data of the oil piping in the actual plant are collected and statistically analyzed as corrosion rate data which are classified by the operation condition. By the analysis, the probabilistic properties of corrosion rate are clarified in this piping system. Especially it is cleared that the corrosion rate of the air injection part is higher than that of the no air injection part. And the reliabilities of the protection of the failure by pressure and their change are quantitatively evaluated from the probabilistic properties of corrosion rate. From this case study, the procedure of FCA evaluation of FFS assessment was established and it's clear that the statistical analysis by the feature of thinning phenomena is important for accurate evaluation of corrosion data.

Journal Articles

Coherent X-ray scattering study of relaxor ferroelectrics

Owada, Kenji

Koatsuryoku No Kagaku To Gijutsu, 23(3), p.245 - 251, 2013/08

Application of coherent X-ray will be one of the main streams in the next generation synchrotron science. Many kinds of the methodologies have been established by using 3rd-generation synchrotron light sources. In this article, the author focuses on a so-called X-ray photon correlation spectroscopy (XPCS), and shows the recent advances in the application of XPCS to relaxor ferroelectrics.

Journal Articles

Pressure-induced phase separation of rare-earth metal dihydrides

Machida, Akihiko; Watanuki, Tetsu; Aoki, Katsutoshi

Koatsuryoku No Kagaku To Gijutsu, 21(3), p.168 - 175, 2011/10

This article reports the recent studies of the pressure-induced phase separation of rare-earth metal dihydrides. Synchrotron radiation X-ray diffraction patterns of LaH$$_{2.3}$$ shows that additional Bragg reflections appeared just outside of the original ones around 11 GPa, indicating the formation of the small fcc metal lattice. The coexistence state of two fcc metal lattices thus observed is interpreted in terms of phase separation from the dihydride toward lower and higher concentration phases. The formation of insulating LaH$$_{2+delta}$$ ($$delta geq 0.7$$) is confirmed by infrared spectroscopy, which shows decrease in reflection intensity. These results indicate that the interstitial hydrogen atoms transfer form T-sites and the domains of solid solution and higher concentration hydride are formed. Pressure-induced phase separation of metal hydrides would develop a new research field, that is, the dynamics of hydrogen transfer in a metal lattice.

Journal Articles

Raman and UV-visible absorption spectroscopy of rare-earth hydride under high pressure

Kume, Tetsuji*; Machida, Akihiko; Aoki, Katsutoshi; Sasaki, Shigeo*; Shimizu, Hiroyasu*

Koatsuryoku No Kagaku To Gijutsu, 21(3), p.184 - 189, 2011/09

Raman and visible absorption spectra of rare earth trihydrides have been measured at high pressures, in order to investigate the structural and electronic phase transitions. The successive phase transitions of hcp-intermediatefcc phase were confirmed by Raman measurements. From the visible absorption experiments, the band gap energy was estimated. The gap closure was found to occur on the transition from the intermediate to the fcc phase.

Journal Articles

Electrical resistance measurement techniques for metal hydrides under high-pressure H$$_2$$ conditions & electrical transport and structural properties of FeH$$_x$$

Matsuoka, Takehiro*; Hirao, Naohisa*; Oishi, Yasuo*; Shimizu, Katsuya*; Machida, Akihiko; Aoki, Katsutoshi

Koatsuryoku No Kagaku To Gijutsu, 21(3), p.190 - 196, 2011/09

We present the newly developed electrical resistance measurement technique for metal hydrides compressed in high-pressure H$$_2$$ and the first successful ${it in-situ}$ simultaneous measurements of electrical resistance and X-ray diffraction of FeH at high pressures and low temperatures. The electrical resistivity $$rho$$ showed a sharp increase with the formation of iron-hydride FeH$$_x$$ ($$xsim1$$) at 3.5 GPa. The $$epsilon$$'-phase of FeH was found to be metallic up to 25.5 GPa. The $$rho$$ vs. $$T$$ curves up to 16.5 GPa approximately follow Fermi-liquid law below 25 K. However, $$T^5$$ was found to be better fitting at 25.5 GPa. This change can be related to the previously reported ferromagnetism collapse at corresponding pressures.

Journal Articles

High pressure study of AlH$$_{3}$$ for practical hydrogen storage material

Saito, Hiroyuki

Koatsuryoku No Kagaku To Gijutsu, 20(2), p.166 - 174, 2010/05

Aluminum tri-hydride (AlH$$_{3}$$) is promising as a hydrogen storage material. Hydrogenation and dehydrogenation mechanism of aluminum still remain unclear and fundamental study of the Al-H system is required to utilize AlH$$_{3}$$ as a practical hydrogen storage material. Aluminum is hydrogenated under high pressure and high temperature to clarify the reaction mechanism. The hydrogenation and dehydrogenation process is investigated using an energy-dispersive and an angle-dispersive in situ X-ray diffraction system.

Journal Articles

Development of high-pressure technique for single-crystal magnetic neutron diffraction under 10 GPa

Osakabe, Toyotaka; Yamauchi, Hiroki; Okuchi, Takuo*

Koatsuryoku No Kagaku To Gijutsu, 20(1), p.72 - 75, 2010/02

A new hybrid-type anvil technique for high-pressure single-crystal magnetic neutron diffraction under 10 GPa is described. The hybrid anvil is composed of an opposed pair of two kinds of anvils. One is a large sapphire anvil or a supported SiC anvil and the other is a tungsten carbide (WC) anvil which has a hollow in the center of the culet. In a feasibility test of the hybrid anvil, we could generate the pressure up to 10 GPa at the load of 3.8 tons with high stability.

Journal Articles

Evaluation of deformation behavior of In grains and grain boundaries of L-grade austenitic stainless steel 316L

Nagashima, Nobuo*; Hayakawa, Masao*; Tsukada, Takashi; Kaji, Yoshiyuki; Miwa, Yukio*; Ando, Masami*; Nakata, Kiyotomo*

Atsuryoku Gijutsu, 47(4), p.236 - 244, 2009/07

In this study, micro-hardness tests and AFM observations were performed on SUS316L low-carbon austenitic stainless steel pre-strained by cold rolling to investigate its deformation behavior. The following results were obtained. Despite the fact that the same plastic strain was applied, post-tensile test AFM showed narrower slip-band spacing in a reduction in area of 30% cold-rolled specimen than the unrolled specimen. Concentrated slip bands were observed near grain boundaries. Micro-hardness exceeding 300 was found to occur frequently in after tensile test specimens with a reduction in area of 30% or more, particularly at grain boundaries. It is suggested that the nonuniformity of deformation at grain boundaries plays an important role of IGSCC crack propagation mechanism of low-carbon austenitic stainless steel.

Journal Articles

Strategy of high pressure research with neutron at J-PARC

Utsumi, Wataru

Koatsuryoku No Kagaku To Gijutsu, 19(1), p.10 - 14, 2009/03

User operation of J-PARC started in December of 2008. It is expected that high pressure material science and the investigation of the Earth's interior will greatly improve using the high flux pulse neutrons of J-PARC. In this article, I introduce the current status of neutron powder diffraction beamlines and our strategy of high pressure experiments.

Journal Articles

High pressure neutron scattering experiments on hydrogen storage materials

Machida, Akihiko; Otomo, Toshiya*; Hattori, Takanori; Fukazawa, Hiroshi

Koatsuryoku No Kagaku To Gijutsu, 19(1), p.24 - 30, 2009/02

We have investigated the fundamental properties of metal hydrides or hydrogen storage materials. The interest is focused on basic understanding of the hydrogen-metal interactions in metal hydride systems. Neutron scattering technique, which is capable of determining hydrogen positions and bonding states, is a key tool to investigate the interactions, and becomes significantly powerful when combined with high pressure technique, which realizes high hydrogen density states by compression of metal lattices. In this article, we present high-pressure neutron scattering techniques using Paris-Edinburgh cell and hydrogen-gas cell under development at J-PARC and JRR-3.

Journal Articles

The World class neutron source J-PARC to be ready for action

Arai, Masatoshi

Koatsuryoku No Kagaku To Gijutsu, 19(1), p.4 - 9, 2009/02

no abstracts in English

Journal Articles

Evaluation method of thermal deformation for Fast Spectrum Light Water Reactor (FLWR)

Ishijima, Yasuhiro; Ioka, Ikuo; Kiuchi, Kiyoshi; Kaneko, Tetsuji*; Okubo, Tsutomu; Yamamoto, Masahiro

Atsuryoku Gijutsu, 47(1), p.12 - 17, 2009/01

We investigate one of these innovative water reactors; Fast Spectrum Light Water Reactor (FLWR). It has unique construction for the reactor core but the fuel cladding material will be exposed in high internal pressure and axial load and complex temperature distribution. Therefore, we conducted a specially designed fatigue-creep test that were simulated several parameters (thermal distribution, temperature variation, internal pressure variation and binding stress) to evaluate an applicability of fuel cladding material for FLWR. Zircalloy-2, which is common cladding material, was used for the test. Test result was confirmed to compare the deformation value between tested and calculated. The result showed the evaluation method could be controlled several parameters simultaneously and the deformation value after the test coincided to the calculated value. This method is sufficient to evaluate thermal deformation characteristics for FLWR.

Journal Articles

Frontier of high pressure research on metal hydrides

Aoki, Katsutoshi; Machida, Akihiko; Omura, Ayako*; Watanuki, Tetsu

Koatsuryoku No Kagaku To Gijutsu, 18(3), p.273 - 278, 2008/08

The highly compressed state of metal hydride has been investigated to explore structural and electronic transitions characteristic to hydride. The hydrogen atoms play the lead in the transitions, showing displacement in or transfer between the interstitial sites of a metal lattice. One example is the band gap closing observed for a long period lattice of yttrium tri-hydride, appearing at pressures above 12 GPa. Another example is photochromic event observed again for yttrium hydride. The former is likely accompanied by the in-site displacement of hydrogen atoms and the latter by the site-to-site transfer.

Journal Articles

A High pressure experiment of powder neutron diffraction on the HRPD at JRR-3

Komatsu, Kazuki*; Arima, Hiroshi*; Kagi, Hiroyuki*; Okuchi, Takuo*; Sasaki, Shigeo*; Yamauchi, Hiroki; Fukazawa, Hiroshi; Igawa, Naoki; Utsumi, Wataru; Kamiyama, Takashi*

Koatsuryoku No Kagaku To Gijutsu, 18(2), p.170 - 172, 2008/05

In this short communication, we report neutron diffractions under high pressure from lead powder in a Paris-Edinburgh cell at the High Resolution Powder Diffractometer (HRPD) installed at JRR-3, Ibaraki, Japan. This is the kick-off experiment in Japan as a high pressure powder diffraction study using reactor neutron source.

Journal Articles

International Workshop on Crystallography at High Pressures

Hattori, Takanori

Koatsuryoku No Kagaku To Gijutsu, 17(1), p.75 - 76, 2007/02

The international workshop "crystallography at high pressures-2006", which was held at Dubna in Russia from Sept. 28th to Oct 1st., is introduced. The workshop was organized by the Commission on High Pressure of the International Union of Crystallography and the Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research (JINR). About 80 participants attended the workshop and 31 oral presentations and 36 poster presentation have done. The workshop consisted of the following sessions: Simple elements, Molecular Solids, Physical Properties of Magnetic Structures, Material Sciences and high-pressure Synthesis, Mineral Physics and Geophysics, Technical developments, Organics, Liquid and amorphous Materials, Carbon and nano materials. In the conference, many noticeable studies which are unfamiliar to high-pressure scientists, such as neutron scattering or $$gamma$$-ray angular correlation, were presented by the scientists in JINR. The pulse neutron source IBR-2 and the experiments which have done in that facility are also introduced.

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