Effect of starch retrogradation on molecular dynamics of cooked rice by quasi-elastic neutron scattering

Hirata, Yoshinobu*; Nakagawa, Hiroshi; Yamauchi, Hiroki; Kaneko, Koji; Hagihara, Masato; Yamaguchi, Hideyuki*; Omoto, Chie*; Katsuno, Nakako*; Imaizumi, Teppei*; Nishizu, Takahisa*

Food Hydrocolloids, 141, p.108728_1 - 108728_7, 2023/08

https://doi.org/10.1016/j.foodhyd.2023.108728

Crystallinity is reflected in the mechanical properties of foods and materials. Crystallinity should be related to the structural dynamics of starch. In this study, we used quasi-elastic neutron scattering (QENS) to investigate changes in the molecular dynamics of cooked rice starch during retrogradation. The width of the measured QENS narrowed with retrogradation. The elastic incoherent structure factor (EISF) increased, which indicated that the molecular dynamics are spatially suppressed upon retrogradation. Analysis of EISF with a bimodal continuous diffusion model, where low and high mobilities are assumed to correspond to crystalline and amorphous phases, respectively, showed that the fraction of the low-mobility component increases with retrogradation.

Numerical study on influence of Ohnesorge number and Reynolds number on the jet breakup behavior using the lattice Boltzmann method

Iwasawa, Yuzuru*; Abe, Yutaka*; Kaneko, Akiko*; Kanagawa, Tetsuya*; Saito, Shimpei*; Matsuo, Eiji*; Ebihara, Kenichi; Sakaba, Hiroshi*; Koyama, Kazuya*; Nariai, Hideki*

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 7 Pages, 2015/05

For the safety design in which heat is properly removed from the molten fuel after the core disruptive accident in a sodium-cooled fast reactor, the estimation of the breakup behavior of molten fuel discharged into the coolant like a jet is desired. In order to investigate the influence of viscocity on the jet behavior, we simulated a jet discharged into a coolant using the three-dimensional lattice Boltzmann model for two-phase fluid, and examined the influence of Ohnesorge number and Reynolds number on the jet behavior. As a result, we made clear that it is necessary to consider viscosity of the coolant as well as that of the jet for the estimation of jet behavior.

Evaluation of jet breakup behavior by the lattice Boltzmann HCZ model, 1; Evaluation of jet breakup length

Matsuo, Eiji*; Abe, Yutaka*; Iwasawa, Yuzuru*; Ebihara, Kenichi; Kaneko, Akiko*; Sakaba, Hiroshi*; Koyama, Kazuya*

Dai-18-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.75 - 76, 2013/06

When supposing a core distractive accident (CDA) in a sodium-cooled fast reactor (SFR), it is necessary to understand the breakup behavior of the molten core material jet into coolant. Thus, the jet breakup was simulated by the lattice Boltzmann (LB) HCZ model. First, the applicability to jet breakup of the LBHCZ model was verified by comparing the simulation result to our experimental data. Next, from sensitive analyses by the simulation, it was found that the jet breakup length is in good agreement with Epstein's correlation when hydrodynamic fragmentation is a dominant phenomenon of the jet breakup.

Influence of fragmentation on jet breakup behaviour

Iwasawa, Yuzuru*; Abe, Yutaka*; Kaneko, Akiko*; Kuroda, Taihei*; Matsuo, Eiji*; Ebihara, Kenichi; Sakaba, Hiroshi*; Koyama, Kazuya*; Ito, Kazuhiro*; Nariai, Hideki*

Proceedings of 15th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-15) (USB Flash Drive), 12 Pages, 2013/05

In the safety design of a Fast Breeder Reactor(FBR), when it is supposed that a Core Disruptive Accident(CDA) occurs, it is strongly required that molten core materials are completely solidified and are cooled down by sodium coolant in a reactor vessel. In this study, we injected molten alloy and transparent fluid, which are a simulant of the molten core material, into water, which is a simulant of the coolant. In this study, we injected molten alloy and transparent fluid, which simulate the molten core material, into water, which simulates the coolant. In the experiment, we observed the jet breakup behavior of them using a high speed video camera, and compared the observe images with the previous theories. In addition, we simulated numerically the qualitative behavior of the liquid jet using a two-phase fluid model of the lattice Boltzmann method.

Application of clear polymethylmethacrylate dosimeter Radix W to a few MeV electron in radiation processing

Seito, Hajime; Ichikawa, Tatsuya*; Hanaya, Hiroaki; Sato, Yoshishige*; Kaneko, Hirohisa; Haruyama, Yasuyuki; Watanabe, Hiroshi*; Kojima, Takuji

Radiation Physics and Chemistry, 78(11), p.961 - 965, 2009/11

https://doi.org/10.1016/j.radphyschem.2009.07.018

no abstracts in English

Measurements of double-differential neutron-production cross-sections for the Be(p,xn) and Be(d,xn) reactions at 10 MeV

Iwamoto, Yosuke; Sakamoto, Yukio; Matsuda, Norihiro; Nakane, Yoshihiro; Ochiai, Kentaro; Kaneko, Hirohisa; Niita, Koji*; Shibata, Tokushi; Nakashima, Hiroshi

Nuclear Instruments and Methods in Physics Research A, 598(3), p.687 - 695, 2009/01

https://doi.org/10.1016/j.nima.2008.10.019

Double-differential neutron-production cross-sections of a thin beryllium target bombarded with 10 MeV protons and deuterons were measured. Neutron energy spectra in the range above 1.8 MeV were obtained by a time-of-flight method at angles of 15, 30, 45, 60, 75, 90 and 120 degrees. Monte Carlo calculations with the PHITS code were performed using the evaluated nuclear data files ENDF/B-VII, the Bertini/GEM model and the JQMD/GEM model, and compared with the experimental results. It was found that the calculated results using ENDF/B-VII and Bertini/GEM for the Be(p,xn) reaction and JQMD/GEM for the Be(d,xn) reaction roughly agreed with the experimental results.

Measurement of internal strain in materials using high energy white X-ray at SPring-8

Shibano, Junichi*; Shobu, Takahisa; Suzuki, Kenji*; Kiriyama, Koji; Kajiwara, Kentaro*; Kaneko, Hiroshi; Kobayashi, Michiaki*

Materials Science Forum, 571-572, p.267 - 270, 2008/00

Ratio of aerosol and gases of radioactive chlorine and particle size distribution of aerosol formed by high-energy proton irradiation

Yokoyama, Sumi; Sato, Kaoru; Manabe, Kentaro; Noguchi, Hiroshi; Kaneko, Hirohisa; Oki, Yuichi*; Iida, Takao*; Tanaka, Susumu*

Radiation Protection Dosimetry, 127(1-4), p.392 - 397, 2007/11

https://doi.org/10.1093/rpd/ncm475

To estimate internal doses due to the inhalation of radionuclides produced by the nuclear spallation of the air nuclei in high-energy proton accelerator facilities, the physicochemical properties of radionuclides are very important. However, there is not enough information of the properties for airborne radioactive chlorine formed from argon gas in the air of a high-energy proton irradiation field. Thus we have measured the ratio of aerosol and gases of radioactive chlorine which are formed by irradiating argon gas-added air with a 48 MeV proton beam. In addition, the particle size distribution and chemical form of non-radioactive aerosol were examined. It was found that Cl-38 and Cl-39 exist as aerosol, acidic and non-acidic gases. The percentages of Cl-38 and Cl-39 aerosols are more than 70%. In total radioactive chlorine gas, about 30% and 70% are acidic and non-acidic gases, respectively. The concentration of non-radioactive aerosol had a peak at an aerodynamic diameter of 20-30 nm in the early irradiation period. The particle size of non-radioactive aerosol shifted to larger with time. After 10 min, the aerosols grew very slowly and many of the non-radioactive aerosols were distributed widely under 200 nm. This suggests that the diameter of the radioactive chlorine aerosol formed by the attachment of the radioactive chlorine to the non-radioactive aerosol around a beam line of the accelerator is much smaller than the default value adopted in ICRP Publication 66.

Measurement of internal strain in materials using high energy synchrotron radiation white X-rays

Shibano, Junichi*; Shobu, Takahisa; Suzuki, Kenji*; Hirata, Tomoyuki*; Kaneko, Hiroshi; Kobayashi, Michiaki*

Zairyo, 56(10), p.985 - 992, 2007/10

https://doi.org/10.2472/jsms.56.985

This paper presents a basic research on a measurement of strain in the bulk of materials by using high energy white X-rays from a synchrotron radiation source of SPring-8. WEL-TEN780E (JIS G3128 SHY685) whose grain size was 0.013 mm was used as a specimen. The specimen was loaded with four point bending. The white X-ray beam, which has a height of 0.05 mm and width of 0.03 mm, was incident in it. Bending strain at the surface of specimen was measured by a strain gauge. The internal strain of SHY685 of 5 mm thickness could be evaluated using white X-rays which range of energy from 60 keV to 150 keV. Furthermore, the measurement error of strain could be decreased by using the diffracted X-rays with high energy, high peak count and the profile which is close to Gaussian curve. The results showed that the high energy white X-ray is effective for internal strain measurements.

Development of a single-crystal X-ray diffraction system for hydrostatic-pressure and low-temperature structural measurement and its application to the phase study of quasicrystals

Watanuki, Tetsu; Machida, Akihiko; Ikeda, Tomohiro*; Omura, Ayako*; Kaneko, Hiroshi; Aoki, Katsutoshi; Sato, Taku*; Tsai, A. P.*

Philosophical Magazine, 87(18-21), p.2905 - 2911, 2007/06

https://doi.org/10.1080/14786430701358707

We have constructed a single-crystal synchrotron X-ray diffraction system to precisely study the structure under hydrostatic pressure conditions at low temperatures and applied it to a study on the phase transition phenomena of a Cd-Yb periodic approximant and a Cd-Yb quasicrystal. Four phases were newly observed for the 1/1 approximant crystal in a span up to 5.2 GPa and down to 10 K. The innermost part of the atomic clusters of Cd tetrahedra exhibited various orientational ordering sensitively depending on pressure and temperature. High pressure diffraction measurements using a highly parallel synchrotron X-ray beam and a hydrostatically compressed single crystal enabled us to detect the weak diffractions due to the subtle structural changes.