JOPSS - Search Results

Journal Articles

Numerical simulation of hydrogen thermal desorption profile under assumption of two kinds of trap sites for tempered martensitic steel

Tsuchida, Yutaka*; Ebihara, Kenichi

Tetsu To Hagane, 103(11), p.653 - 659, 2017/11

https://doi.org/10.2355/tetsutohagane.TETSU-2017-039

Times Cited Count：2 Percentile：11.25(Metallurgy & Metallurgical Engineering)

A single peak in thermal desorption profiles of hydrogen, which are measured in low-temperature thermal desorption spectrometry (L-TDS) for a very thin plate specimen of tempered martensitic steel, was reproduced successfully by the superposition of two Gaussian distributions. Then, the parameters concerning the detrapping rate constants for both peaks, which are trap energy and pre-exponential factor, were calculated using the Choo-Lee plot. We confirmed that Kissinger model incorporating the obtained parameters could simulate the two peaks. In addition, we reproduced the single peak well using the reaction-diffusion equation incorporating the obtained parameters and the appropriate trap site concentration. From the results, we interpreted that the one peak corresponds to dislocation and the other to grain-boundary.

Journal Articles

Novel mechanism of antibiotic resistance originating in vancomycin-intermediate

Cui, L.*; Iwamoto, Akira; Lian, J.-Q.*; Neoh, H.*; Maruyama, Toshiki; Horikawa, Yataro*; Hiramatsu, Keiichi*

Antimicrobial Agents and Chemotherapy, 50(2), p.428 - 438, 2006/02

https://doi.org/10.1128/AAC.50.2.428-438.2006

Times Cited Count：170 Percentile：97.67(Microbiology)

no abstracts in English

Journal Articles

Effect of higher-harmonic flux in exponential experiment for subcriticality measurement

Yamamoto, Toshihiro; Miyoshi, Yoshinori; Tonoike, Kotaro; Okamoto, Hajime*; Ida, Toshikazu*; Aoki, Shigeaki*

Journal of Nuclear Science and Technology, 40(2), p.77 - 83, 2003/02

https://doi.org/10.3327/jnst.40.77

Times Cited Count：8 Percentile：49.8(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

The Acceleration factor and inhibitor of the generation and growth of the cavity at high temperature; Computer simulation on growth of cavity

; Ueno, Fumiyoshi

JNC TN9400 2000-017, 10 Pages, 2000/03

JNC-TN9400-2000-017.pdf:0.58MB

lt is difficult to get hold the behave of growth of cavity which nucleates in grain boudaly in experimental observation. lt is considerd that numerical simulation is effective for the grasp of behave of cavity growth, because it is able to grasp the microscopic behavior of internal material whici is hardly observation. We examine the factor that the diffusive ratio and the stress etc., affected growth of cavity on grain boundary with numerical simulation using diffusive equation. As the result, a following knowledge was obtained. (1)With dominant of grain boundary diffusion, the shape of cavity transitions from quasi-equilibrium to crac-like. ln other hand, with dominant of surface diffusion, cavity grows up with initial shape. (2)With dominate of grain boundary diffusion, it accelerates the growth rate of the cavity near the tip by grain boundaly diffusion induced stressing perpendicular to gain boundary (3)With dominant of surface diffusion, the distribution of chemical potential is uniformity on cavity surface. ln other hand, with dominant of grain boundary diffusion compare to that of surface diffusion, the gradient of chemical potential is increased at the tip of cavity.

Journal Articles

Outline of three-dimensional nodal neutron diffusion calculation code MOSRA-Light

Okumura, Keisuke

RIST News, (29), p.10 - 16, 2000/03

no abstracts in English

JAEA Reports

Study on migration behavior of radionuclides in engineered clay barrier (II)

*; *; *

JNC TJ8400 2000-018, 79 Pages, 2000/02

JNC-TJ8400-2000-018.pdf:2.09MB

As a basic research for geological disposal of high-level radioactive wastes, diffusion behavior of radionuclides and corrosion behavior of overpack materials in clay buffer materials (bentonite) were studied. In the study on the diffusion behavior of radionuclides, basal spacing and water content were determined for water saturated, compacted Na-montmorillonite that is major clay mineral of bentonite. The apparent diffusion coefficients of Na $^{+}$ , Sr $^{2+}$ , Cs $^{+}$ and Cl $^{-}$ ions and their activation energies were also determined at different dry densities of montmorillonite. For all kinds of ions, the activation energies were found to increase as the dry density increased. These findings suggest that the diffusion mechanism of ions in compacted montmorillonite changed with increasing dry density. As a reasonable explanation for the changes in the activation energy, we proposed a multiprocess diffusion model, in which predominant diffusion process is considered to change from pore water diffusion to interlayer diffusion via surface diffusion when the dry density increases. The Na-montmorillonite is expected to alter by the ion exchange with Ca $^{2+}$ ions, which could be introduced from groundwater and/or cementitious materials in a repository. The apparent diffusion coefficients of Na $^{+}$ and Cs $^{+}$ ions and their activation energies were studied for Na/Ca montmorillonite mixtures in order to know the effect of this kind of alteration on the diffusion behavior of ions. It was found that the alteration of montmorillonite affected diffusion coefficients and the activation energies for both kinds of cations. These effects cannot be explained only by the pore water diffusion. The multiprocess diffusion model proposed in this study is suggested as the most reasonable explanation for the effects. The oxidation behavior of pyrite in bentonite during drying process was studied for understanding corrosion behavior of overpack materials in bentonite. There ...

JAEA Reports

None

*; *; *; *

PNC TJ1277 98-002, 74 Pages, 1998/02

PNC-TJ1277-98-002.pdf:3.05MB

None

JAEA Reports

None

*; *; *; *

PNC TJ1277 98-001, 204 Pages, 1998/02

PNC-TJ1277-98-001.pdf:6.59MB

None

JAEA Reports

A Study of iodine diffusion in rare gases(III)

Sagawa, Norihiko*

PNC TJ9613 97-002, 95 Pages, 1997/10

PNC-TJ9613-97-002.pdf:2.22MB

The diffusion coefficient of cesium iodide vapor in rare gases was determined by a modified Stefan's method. The rare gas in a diffusion column was saturated with vapor of the cesium iodide, crystals of which were heated to melt at the bottom of the column. By opening a valve united at a top of the column, the vapor diffusing through the column was transferred with the carrier rare gas to an ionization sensor. The concentration of cesium iodide in the carrier gas was continuously monitored with the sensor. The diffusion coefficient was determined by analyzing the transient response of the concentration. Increasing tendency with temperature is observed in the coefficients obtained in argon, kripton and xenon at temperatures between 631 and 691 $^{circ}$ C and no significant difference among the coefficients in argon, krypton and xenon.