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Tong, Z.*; Xia, C.*; Li, W.*; Ding, W.*; Guo, B.*; Min, N.*; Gong, W.; Harjo, S.; Tsuji, Nobuhiro*
Journal of Materials Science & Technology, 266, p.127 - 140, 2026/09
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)
underwater radiation monitoring detectorJi, W.*; Lee, E.*; Ji, Y.-Y.*; Ochi, Kotaro; Yoshimura, Kazuya; Funaki, Hironori; Sanada, Yukihisa
Nuclear Engineering and Technology, 58(2), p.103933_1 - 103933_6, 2026/02
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)We aimed to validate the performance of an in situ underwater radiation detector, MARK-U1 (Monitoring of Ambient Radiation of KAERI - Underwater), was used to estimate 
Cs activity concentration in river and reservoir sediment at predicted sites of contamination. Additionally, underwater core samples were collected to measure the radioactivity using a high-purity germanium (HPGe) detector. To estimate radioactivity, a conversion factor was derived by comparing the measured spectrum and Cs activity in the sample. A Monte Carlo N-Particle (MCNP) simulation was conducted to determine the effective source geometry for in situ measurement. The simulation results correlated well with the on-site MARK-U1 monitoring results, with a deviation of 31.62%. These findings validate the performance of the in situ detector. This device can therefore be used to estimate Cs activity concentration in the underwater sediment via on-site monitoring, without requiring sample collection.
Ji, Y.-Y.*; Ji, W.*; Kim, K.*; Kim, M. J.*; Ochi, Kotaro; Morishita, Yuki; Sanada, Yukihisa
Radiation Physics and Chemistry, 244, p.113781_1 - 113781_12, 2026/02
Times Cited Count：0 Percentile：0.00(Chemistry, Physical)UAV-based airborne gamma-ray spectrometry enables rapid radiation mapping, but accurate estimation of ground-level ambient dose rates is difficult because of altitude attenuation, detector field-of-view effects, heterogeneous contamination, and terrain variability. We developed a practical method combining hovering-flight calibration and ground-based validation near the Fukushima Daiichi Nuclear Power Plant. Altitude correction factors were derived using a dual-exponential model and compared with tripod and backpack measurements. Results showed that heterogeneous contamination and terrain introduce systematic biases if correction factors are derived under non-uniform conditions, while calibration at uniform sites improves agreement. The proposed approach demonstrates that UAV airborne surveys can reliably estimate spatial dose-rate distributions when site-dependent corrections are applied.
Ji, Y.-Y.*; Joung, S.*; Ji, W.*; Ochi, Kotaro; Sasaki, Miyuki; Sanada, Yukihisa
Journal of Radiological Protection, 45(4), p.042501_1 - 042501_11, 2025/12
Times Cited Count：3 Percentile：98.65(Environmental Sciences)This study reports the development and field validation of KAERI's UAV-based gamma-ray spectrometry system equipped with LaBr
(Ce) detectors. Joint surveys with JAEA near Fukushima Daiichi Nuclear Power Plant (FDNPP) showed reliable dose rate estimation after applying altitude based attenuation correction, through discrepancies occurred in sloped terrain. Incorporating terrain data is recommended to enhance accuracy for emergency response applications.
-nonyl N,N-dimethylammonio)-propyl sulfate, present in isotropic solutions above its upper critical solution temperatureTanji, Tamao*; Kusunoki, Yuto*; Nakagawa, Taichi; Takase, Tsugiko*; Ueda, Yuki; Motokawa, Ryuhei; Hinze, W. L.*; Takagai, Yoshitaka*
Langmuir, 41(21), p.13184 - 13191, 2025/06
Times Cited Count：0 Percentile：0.00(Chemistry, Multidisciplinary)Joung, S.*; Ji, Y.-Y.*; Choi, Y.*; Lee, E.*; Ji, W.*; Sasaki, Miyuki; Ochi, Kotaro; Sanada, Yukihisa
Journal of Instrumentation (Internet), 20(4), p.P04027_1 - P04027_10, 2025/04
Times Cited Count：1 Percentile：34.03(Instruments & Instrumentation)Go, J.*; Park, M.-H.*; Gao, S.*; Matsumiya, Hisashi*; Gong, W.; Tsuji, Nobuhiro*
Journal of Alloys and Compounds, 1014, p.178749_1 - 178749_10, 2025/02
Times Cited Count：15 Percentile：96.30(Chemistry, Physical)Mao, W.*; Gao, S.*; Gong, W.; Kawasaki, Takuro; Ito, Tatsuya; Harjo, S.; Tsuji, Nobuhiro*
Acta Materialia, 278, p.120233_1 - 120233_13, 2024/10
Times Cited Count：63 Percentile：99.09(Materials Science, Multidisciplinary)Sn wires with and without Cu-Nb reinforcementNakamoto, Mio*; Sugano, Michinaka*; Ogitsu, Toru*; Sugimoto, Masahiro*; Taniguchi, Ryo*; Hirose, Kiyoshige*; Kawasaki, Takuro; Gong, W.; Harjo, S.; Awaji, Satoshi*; et al.
IEEE Transactions on Applied Superconductivity, 34(5), p.8400806_1 - 8400806_6, 2024/08
Times Cited Count：1 Percentile：10.70(Engineering, Electrical & Electronic)Guo, B.*; Chen, H.*; Chong, Y.*; Mao, W.; Harjo, S.; Gong, W.; Zhang, Z.*; Jonas, J. J.*; Tsuji, Nobuhiro*
Acta Materialia, 268, p.119780_1 - 119780_11, 2024/04
Times Cited Count：30 Percentile：95.93(Materials Science, Multidisciplinary)
complex exhibiting intermolecular proton shifting coupled spin transitionJi, T.*; Su, S.*; Wu, S.*; Hori, Yuta*; Shigeta, Yasuteru*; Huang, Y.*; Zheng, W.*; Xu, W.*; Zhang, X.*; Kiyanagi, Ryoji; et al.
Angewandte Chemie; International Edition, 63(25), p.e202404843_1 - e202404843_6, 2024/04
Times Cited Count：4 Percentile：35.29(Chemistry, Multidisciplinary)
neutron diffraction revealing the achievement of excellent combination of strength and ductility in metastable austenitic steel by grain refinementMao, W.; Gong, W.; Harjo, S.; Morooka, Satoshi; Gao, S.*; Kawasaki, Takuro; Tsuji, Nobuhiro*
Journal of Materials Science & Technology, 176, p.69 - 82, 2024/03
Times Cited Count：28 Percentile：89.13(Materials Science, Multidisciplinary)The yield stress of Fe-24Ni-0.3C (wt.%) metastable austenitic steel increased 3.5 times (158 
551 MPa) when the average grain size decreased from 35 
m (coarse-grained [CG]) to 0.5 m (ultrafine-grained [UFG]), whereas the tensile elongation was kept large (0.87 0.82). neutron diffraction measurements of the CG and UFG Fe-24Ni-0.3C steels were performed during tensile deformation at room temperature to quantitatively elucidate the influence of grain size on the mechanical properties and deformation mechanisms. The initial stages of plastic deformation in the CG and UFG samples were dominated by dislocation slip, with deformation-induced martensitic transformation (DIMT) also occurring in the later stage of deformation. Results show that grain refinement increases the initiation stress of DIMT largely and suppresses the rate of DIMT concerning the strain, which is attributed to the following effects. (i) Grain refinement increased the stabilization of austenite and considerably delayed the initiation of DIMT in the 
111
//LD (LD: loading direction) austenite grains, which were the most stable grains for DIMT. As a result, most of the 111//LD austenite grains in the UFG specimens failed to transform into martensite. (ii) Grain refinement also suppressed the autocatalytic effect of the martensitic transformation. Nevertheless, the DIMT with the low transformation rate in the UFG specimen was more efficient in increasing the flow stress and more appropriate to maintain uniform deformation than that in the CG specimen during deformation. The above phenomena mutually contributed to the excellent combination of strength and ductility of the UFG metastable austenitic steel.
Tsuchida, Noriyuki*; Kuramoto, Shota*; Ueji, Rintaro*; Gong, W.; Harjo, S.; Hiroi, Kosuke; Kawamura, Yukihiko*
ISIJ International, 64(2), p.354 - 360, 2024/01
Times Cited Count：0 Percentile：0.00(Metallurgy & Metallurgical Engineering)Ueji, Rintaro*; Gong, W.; Harjo, S.; Kawasaki, Takuro; Shibata, Akinobu*; Kimura, Yuji*; Inoue, Tadanobu*; Tsuchida, Noriyuki*
ISIJ International, 64(2), p.459 - 465, 2024/01
Times Cited Count：4 Percentile：38.96(Metallurgy & Metallurgical Engineering)Soler, J. M.*; Kek
linen, P.*; Pulkkanen, V.-M.*; Moreno, L.*; Iraola, A.*; Trinchero, P.*; Hokr, M.*; 
ha, J.*; Havlov
, V.*; Trpko
ov, D.*; et al.
Nuclear Technology, 209(11), p.1765 - 1784, 2023/11
Times Cited Count：6 Percentile：66.64(Nuclear Science & Technology)
ders band deformation in an ultrafine grain stainless steel by combining neutron diffraction and digital image correlation analysisMao, W.; Gao, S.*; Gong, W.; Harjo, S.; Kawasaki, Takuro; Tsuji, Nobuhiro*
Scripta Materialia, 235, p.115642_1 - 115642_6, 2023/10
Times Cited Count：27 Percentile：88.32(Nanoscience & Nanotechnology)In the present study, a hybrid neutron diffraction and digital image correlation measurement was performed on tensile deformation of an ultrafine grain (UFG) stainless steel exhibiting a huge Lders band deformation to evaluate the individual contribution of the austenite matrix and the deformation-induced martensite to the strain hardening during the propagation of the band. Quantitative analysis revealed that the strain hardening of the austenite matrix was insufficient to maintain a uniform deformation when the flow stress was greatly enhanced by the UFG structure. The strain hardening required for the Lders band to propagate was mostly provided by the formation of martensite and the high internal stress within it.
Mao, W.; Gao, S.*; Gong, W.; Bai, Y.*; Harjo, S.; Park, M.-H.*; Shibata, Akinobu*; Tsuji, Nobuhiro*
Acta Materialia, 256, p.119139_1 - 119139_16, 2023/09
Times Cited Count：77 Percentile：99.11(Materials Science, Multidisciplinary)Transformation-induced plasticity (TRIP)-assisted steels exhibit an excellent combination of strength and ductility due to enhanced strain hardening rate associated with deformation-induced martensitic transformation (DIMT). Quantitative evaluation on the role of DIMT in strain hardening behavior of TRIP-assisted steels and alloys can provide guidance for designing advanced materials with strength and ductility synergy, which is, however, difficult since the phase composition keeps changing and both stress and plastic strain are dynamically partitioned among constituent phases during deformation. In the present study, tensile deformation with neutron diffraction measurement was performed on an Fe-24Ni-0.3C (wt.%) TRIP-assisted austenitic steel. The analysis method based on stress partitioning and phase fractions measured by neutron diffraction was proposed, by which the tensile flow stress and the strain hardening rate of the specimen were resolved into factors associated with each phase, i.e., the austenite matrix, deformation-induced martensite, and the transformation rate of DIMT after differentiation, and then the role of each factor in the global strain hardening behavior was discussed. In addition, the plastic strain partitioning between austenite and martensite was indirectly estimated using the dislocation density measured by diffraction profile analysis, which constructed the full picture of stress and strain partitioning between austenite and martensite in the material. The results suggested that both the transformation rate and the phase stress borne by the deformation-induced martensite played important roles in the global tensile properties of the material. The proposed decomposition analysis method could be widely applied to investigating mechanical behavior of multi-phase alloys exhibiting the TRIP phenomenon.
Tamii, Atsushi*; Pellegri, L.*; S
derstrm, P.-A.*; Allard, D.*; Goriely, S.*; Inakura, Tsunenori*; Khan, E.*; Kido, Eiji*; Kimura, Masaaki*; Litvinova, E.*; et al.
European Physical Journal A, 59(9), p.208_1 - 208_21, 2023/09
Times Cited Count：22 Percentile：93.22(Physics, Nuclear)no abstracts in English
neutron diffractionGong, W.; Harjo, S.; Tomota, Yo*; Morooka, Satoshi; Kawasaki, Takuro; Shibata, Akinobu*; Tsuji, Nobuhiro*
Acta Materialia, 250, p.118860_1 - 118860_16, 2023/05
Times Cited Count：40 Percentile：94.78(Materials Science, Multidisciplinary) neutron diffraction studyGong, W.; Kawasaki, Takuro; Zheng, R.*; Mayama, Tsuyoshi*; Sun, B.*; Aizawa, Kazuya; Harjo, S.; Tsuji, Nobuhiro*
Scripta Materialia, 225, p.115161_1 - 115161_5, 2023/03
Times Cited Count：13 Percentile：57.83(Nanoscience & Nanotechnology)