Modeling the transport and deposition of Be produced by the strongest solar proton event during the holocene

Spiegl, T. C.*; Yoden, Shigeo*; Langematz, U.*; Sato, Tatsuhiko; Chhin, R.*; Noda, Satoshi*; Miyake, Fusa*; Kusano, Kanya*; Schaar, K.*; Kunze, M.*

Journal of Geophysical Research; Atmospheres, 127(13), p.e2021JD035658_1 - e2021JD035658_21, 2022/07

https://doi.org/10.1029/2021JD035658

The abundance of cosmogenic isotopes in natural archives carries important information about the complex pathways from their source in the upper atmosphere to their deposition via atmospheric transport processes. Here, we use a new modelling framework to (a) estimate the Be production yield for the 774 CE/775 event, (b) evaluate the performance of our model framework by comparing the model results to four ice core records and (c) investigate the atmospheric pathways with a state-of-the-art climate model in detail. The results give new constraints regarding the seasonal timing of the event, underpin the role of the background conditions in the stratosphere, and highlight regional variations in the cosmogenic surface flux.

Space weather benchmarks on Japanese society

Ishii, Mamoru*; Shiota, Daiko*; Tao, Chihiro*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Ishii, Takako*; Ichimoto, Kiyoshi*; Kataoka, Ryuho*; Koga, Kiyokazu*; Kubo, Yuki*; et al.

Earth, Planets and Space (Internet), 73(1), p.108_1 - 108_20, 2021/12

https://doi.org/10.1186/s40623-021-01420-5

We surveyed the relationship between the scale of space weather events and their occurrence rate in Japan and we discussed the social impact of these phenomena during the Project for Solar-Terrestrial Environment Prediction (PSTEP). The information was compiled for domestic users of space weather forecasts for appropriate preparedness against space weather disasters. This paper gives a comprehensive summary of the survey, focusing on the fields of electricity, satellite operations, communication and broadcasting, satellite positioning usage, aviation, human space activity, and daily life on the Earth's surface, using the cutting-edge knowledge of space weather. Quantitative estimations of the economic impact of space weather events on electricity and aviation are also given.

Dislocation densities and intergranular stresses of plastically deformed austenitic steels

Tomota, Yo*; Ojima, Mayumi*; Harjo, S.; Gong, W.*; Sato, Shigeo*; Ungr, T.*

Materials Science & Engineering A, 743, p.32 - 39, 2019/01

https://doi.org/10.1016/j.msea.2018.09.052

Quantitative evaluation of texture and dislocations during annealing after hot deformation in austenitic steel using neutron diffraction

Tomota, Yo*; Sato, Shigeo*; Uchida, M.*; Xu, P. G.; Harjo, S.; Gong, W.; Kawasaki, Takuro

Materials Science Forum, 905, p.25 - 30, 2017/08

https://doi.org/10.4028/www.scientific.net/MSF.905.25

Rapid measurement scheme for texture in cubic metallic materials using time-of-flight neutron diffraction at iMATERIA

Onuki, Yusuke*; Hoshikawa, Akinori*; Sato, Shigeo*; Xu, P. G.; Ishigaki, Toru*; Saito, Yoichi*; Todoroki, Hidekazu*; Hayashi, Makoto*

Journal of Applied Crystallography, 49(5), p.1579 - 1584, 2016/10

AA2016-0186.pdf:1.13MB

https://doi.org/10.1107/S160057671601164X

Investigation of elastic deformation mechanism in as-cast and annealed eutectic and hypoeutectic Zr-Cu-Al metallic glasses by multiscale strain analysis

Suzuki, Hiroshi; Yamada, Rui*; Tsubaki, Shinki*; Imafuku, Muneyuki*; Sato, Shigeo*; Watanuki, Tetsu; Machida, Akihiko; Saida, Junji*

Metals, 6(1), p.12_1 - 12_11, 2016/01

https://doi.org/10.3390/met6010012

Elastic deformation behaviors of as-cast and annealed eutectic and hypoeutectic Zr-Cu-Al bulk metallic glasses (BMGs) were investigated on a basis of different strain-scales determined by X-ray scattering and the strain gauge. The microscopic strains determined by Direct-space method (DSM) and Q-space method (QSM) were compared with the macroscopic strain measured by the strain gauge, and the difference in the deformation mechanism between eutectic and hypoeutectic Zr-Cu-Al BMGs was investigated by their correlation. The eutectic ZrCuAl BMG obtains more homogeneous microstructure by free-volume annihilation after annealing, improving a resistance to deformation but degrading ductility because of a decrease in the volume fraction of WBRs (Weakly-Bonded Regions) with relatively high mobility. On the other hand, the as-cast hypoeutectic ZrCuAl BMG originally has homogeneous microstructure, but loses its structural and elastic homogeneities because of nanocluster formation after annealing. Such structural changes after annealing might develop unique mechanical properties showing no degradations of ductility and toughness for the structural-relaxed hypoeutectic BMGs.

Evaluation of compressive deformation behavior of ZrAlNiCu bulk metallic glass containing ZrC particles by synchrotron X-ray diffraction

Suzuki, Hiroshi; Saida, Junji*; Shobu, Takahisa; Katsuyama, Jinya; Kato, Hidemi*; Imafuku, Muneyuki*; Sato, Shigeo*

Scripta Materialia, 66(10), p.801 - 804, 2012/05

https://doi.org/10.1016/j.scriptamat.2012.02.016

Compressive deformation mechanism of a ZrAlNiCu bulk metallic glass containing 10vol.%ZrC (ZrC-BMG) was evaluated by measuring the residual strains in the compressive deformed samples using the synchrotron X-ray diffraction and also evaluating the localized deformation behavior around the ZrC particles by the finite element analysis. Phase stress shared by the metallic glass matrix was increased before macroscopic yielding due to local plastic deformation around the ZrC particles. After macroscopic yielding, the phase stress shared by the ZrC phase was drastically increased, and finally the ZrC-BMG was fractured by breaking the ZrC particles reaching its fracture strength.

Increased antitumor effect of chemotherapy, using radiosensitive microcapsules containing anti-RLIP076

Harada, Satoshi*; Ehara, Shigeru*; Ishii, Keizo*; Sato, Takahiro; Yamazaki, Hiromichi*; Matsuyama, Shigeo*; Kamiya, Tomihiro

JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 89, 2012/01

https://doi.org/10.11484/jaea-review-2011-043

The Kinetics of Fe and Ca for the development of radiation-induced apoptosis by micro-PIXE imaging

Harada, Satoshi*; Tamakawa, Yoshiharu*; Ishii, Keizo*; Tanaka, Akira*; Sato, Takahiro; Matsuyama, Shigeo*; Yamazaki, Hiromichi*; Kamiya, Tomihiro; Sakai, Takuro; Arakawa, Kazuo; et al.

Nuclear Instruments and Methods in Physics Research B, 189(1-4), p.437 - 442, 2002/04

https://doi.org/10.1016/S0168-583X(01)01121-1

To study the interactions between the induction of radiation-induced apoptosis and trace elements kinetics, human leukemia cells were irradiated in vitro by Co rays, after which the cells were evaluated for the detection of apoptosis and trace element imaging was carried out. The frequency of apoptosis was obtained by microscopic assay using TUNEL staining. The trace element distribution in the cell was determined by micro-PIXE. In the early phase of apoptosis, the maximum level of Fe accumulation was observed in the cell stroma. In the mid to end phase, Fe accumulation was diminished, and instead, Ca accumulation increased and Zn decreased in the nucleus. There appear to be two steps for the development of apoptosis: (1) the signaling from cell stroma to nucleus by Fe or an Fe-containing enzyme; and (2) the degeneration of the nucleus by Ca-dependent enzyme, and release of Zn from digested nucleus. Those strong accumulations may be new markers for apoptosis.

Evaluation of deformation behavior on metallic glass by neutron diffraction

Suzuki, Hiroshi; Saida, Junji*; Imafuku, Muneyuki*; Sato, Shigeo*

no journal, , 

Residual stress measurements using neutron and X-ray diffractions are applicable to crystalline materials whereas the strain measurement in amorphous materials had been difficult. Recently, Q-space method, which can evaluate the strain from peak shift of 1st halo peak measured by synchrotron X-ray, and Direct space method, which can evaluate the strain from changes in local structures obtained by the radial distribution function, have been reported by Poulsed et al. In this study, the evaluation of tensile deformation in ZrAlNiCu metallic glass using Q-space method was discussed by using neutron diffraction.