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論文

クリープ破断時間および高温引張強度予測モデルの連合学習

櫻井惇也*; 鳥形啓輔*; 松永学*; 高梨直人*; 日比野真也*; 木津健一*; 森田聡*; 井元雅弘*; 下畠伸朗*; 豊田晃大; et al.

鉄と鋼, 111(5), p.246 - 262, 2025/04

https://doi.org/10.2355/tetsutohagane.TETSU-2024-124

Creep testing is time-consuming and costly, leading institutions to limit the number of tests conducted to the minimum necessary for their specific objectives. By pooling data from each institution, it is anticipated that predictive models can be developed for a wide range of materials, including welded joints and degraded materials exposed to service conditions. However, the data obtained by each institution is often highly confidential, making it challenging to share with others. Federated learning, a type of privacy-preserving computation technology, allows for learning while keeping data confidential. Utilizing this approach, it is possible to develop creep life prediction models by leveraging data from various institutions. In this paper, we constructed global deep neural network models for predicting creep rupture life of heat-resistant ferritic steels in collaboration with eight institutions using the federated learning system we developed for this purpose. Each institution built a local model using only its own data for comparison. While these local models demonstrated good predictive accuracy for their respective datasets, their predictive performance declined when applied to data from other institutions. In contrast, the global model constructed using federated learning showed reasonably good predictive performance across all institutions. The distance between each institution's data was defined in the space of explanatory variables, with the NIMS data, which had the largest dataset, serving as the reference point. The global model maintained high predictive accuracy regardless of the distance from the NIMS data, whereas the predictive accuracy of the NIMS local model significantly decreased as the distance increased.

論文

sparse-ir; Optimal compression and sparse sampling of many-body propagators

Wallerberger, M.*; Badr, S.*; Hoshino, Shintaro*; Huber, S.*; Kakizawa, Fumiya*; 是常隆*; 永井佑紀; Nogaki, Kosuke*; 野本拓也*; 森仁志*; et al.

Software X (Internet), 21, p.101266_1 - 101266_7, 2023/02

https://doi.org/10.1016/j.softx.2022.101266

被引用回数：24 パーセンタイル：91.61(Computer Science, Software Engineering)

有限温度の多体量子系におけるグリーン関数の情報をスパースモデリング技術を用いて効率的に圧縮するsparse-irというパッケージを開発したことを報告する。このパッケージを用いることで、一粒子グリーン関数であれば数十個の情報でグリーン関数の全領域での松原振動数依存性を計算することが可能となる。発表代表者の永井はこのソフトウェアの応用例を示すために、このパッケージを使うことで超伝導状態のシミュレーションが精度よくできることを示した。今後、このパッケージを使うことで、重元素化合物などの強相関電子系の物性を精度よく計算することが可能となる。

論文

Spontaneous activation behavior of Ni $_{3}$ Sn, an intermetallic catalyst, for hydrogen production via methanol decomposition

Fan, M.*; Xu, Y.*; 櫻井惇也*; 出村雅彦*; 平野敏幸*; 寺岡有殿; 吉越章隆

International Journal of Hydrogen Energy, 40(37), p.12663 - 12673, 2015/10

https://doi.org/10.1016/j.ijhydene.2015.05.197

被引用回数：14 パーセンタイル：32.49(Chemistry, Physical)

Ni $_{3}$ Sn単相粉末試料のメタノール分解反応に対する触媒特性を調べた。触媒反応は713K, 793K, 873Kの各温度で等温実験であった。793K以上の温度では触媒活性は時間の増加に伴い高くなることを見出した。また、Ni $_{3}$ SnはH $_{2}$ とCOに高い選択性を示すことが分かった。表面キャラクタリゼーションの結果、触媒反応中触媒表面にNi $_{3}$ Sn微粒子が生成されることが分かった。これらの微粒子は自発活性化の原因と考えられる。

論文

Effect of water vapor and hydrogen treatments on the surface structure of Ni $_{3}$ Al foil

Xu, Y.*; Ma, Y.*; 櫻井惇也*; 寺岡有殿; 吉越章隆; 出村雅彦*; 平野敏幸*

Applied Surface Science, 315, p.475 - 480, 2014/10

https://doi.org/10.1016/j.apsusc.2014.02.144

被引用回数：7 パーセンタイル：30.25(Chemistry, Physical)

The Ni $_{3}$ Al foils were heat treated in water vapor at 873 K for 1 h followed by H $_{2}$ reduction at 873 K for 1 h. The effects of the water vapor treatment and the H $_{2}$ reduction on the surface structure of the Ni $_{3}$ Al foils were investigated by means of scanning electron microscopy and synchrotron radiation X-ray photoemission spectroscopy. Both Ni and Al were oxidized during the water vapor treatment; fine NiO particles were formed on the surface, accompanied by the formation of Al(OH) $_{3}$ and NiAl $_{2}$ O $_{4}$ /Al $_{2}$ O $_{3}$ . The NiO particles were reduced to metallic Ni and the Al(OH) $_{3}$ was decomposed to Al $_{2}$ O $_{3}$ , whereas the NiAl $_{2}$ O $_{4}$ and Al $_{2}$ O $_{3}$ remained unchanged during the H $_{2}$ reduction, forming a Ni-enriched porous structure on the surface layer of NiAl $_{2}$ O $_{4}$ / Al $_{2}$ O $_{3}$ .

論文

Catalytic performance of Ni $_{3}$ Sn and Ni $_{3}$ Sn $_{2}$ for hydrogen production from methanol decomposition

Fan, M.*; Xu, Y.*; 櫻井惇也*; 出村雅彦*; 平野敏幸*; 寺岡有殿; 吉越章隆

Catalysis Letters, 144(5), p.843 - 849, 2014/05

https://doi.org/10.1007/s10562-014-1212-x

被引用回数：15 パーセンタイル：34.44(Chemistry, Physical)

In this study, the catalytic properties of Ni $_{3}$ Sn and Ni $_{3}$ Sn $_{2}$ powders were investigated for producing hydrogen from decomposing methanol in the temperatures from 593 to 953 K. The catalytic activities of Ni $_{3}$ Sn and Ni $_{3}$ Sn $_{2}$ both increased with increasing temperature, but Ni $_{3}$ Sn showed much higher catalytic activity than Ni $_{3}$ Sn $_{2}$ . The results of an isothermal test performed at 873 K revealed that the catalytic activity of Ni $_{3}$ Sn significantly increased with methanol decomposition time, indicating that Ni $_{3}$ Sn was spontaneously activated. Ni $_{3}$ Sn and Ni $_{3}$ Sn $_{2}$ both showed a high degree of selectivity and both suppressed side reactions such as methanation and water-gas shift reaction. Surface analysis revealed that fine Ni-Sn particles were formed together with carbon deposited onto the catalyst surface. These Ni-Sn particles were supposed to serve as active sites for methanol decomposition.

口頭

Catalytic performance of Ni $_{3}$ Sn alloy for hydrogen production from methanol decomposition

Fan, M.*; Xu, Y.*; 櫻井惇也*; 出村雅彦*; 平野敏幸*; 寺岡有殿; 吉越章隆

no journal, ,

We have examined the catalytic performance of Ni $_{3}$ Sn for hydrogen production from methanol decomposition. The single-phase Ni $_{3}$ Sn alloy ingot was prepared using a high-frequency furnace. The ingot was mechanically crushed to powders. The powders were sieved to get the samples less than 75 micrometer in size for reaction test. Methanol decomposition was performed in a conventional fixed-bed flow reactor. The characterization of Ni $_{3}$ Sn was carried out by XRD, SEM, BET, and synchrotron XPS in SPring-8. The methanol conversion increased with time indicating that Ni $_{3}$ Sn spontaneously activated during the reaction. It was also found that Ni $_{3}$ Sn shows a high selectivity. The characterization of the samples before and after reaction shows that Ni $_{3}$ Sn phase remained unchanged, and no obvious oxidation of Ni and Sn occurred during reaction, suggesting that Ni $_{3}$ Sn itself might serve as the active species.

口頭

Post analysis of LOFC test Run2

長住達; 櫻井洋亮; 飯垣和彦; 西原哲夫; 角田淳弥

no journal, ,

OECD/NEA国際共同プロジェクトであるLOFCプロジェクトの第6回技術検討グループ(PRG)にて、2024年3月に実施した炉心流量喪失試験(LOFC-Run2)の事後解析の結果を報告した。

口頭

Catalytic properties of Ni $_{3}$ Al foils for methane steam reforming

Xu, Y.*; Ma, Y.*; 櫻井惇也*; 出村雅彦*; 平野敏幸*; 寺岡有殿; 吉越章隆

no journal, ,

Ni $_{3}$ Al intermetallic compound is known as a promising high-temperature structural material because of its excellent high temperature strength and corrosion/oxidation resistance. The brittleness at room temperature used to be a big problem which restricted its practical application. We have overcome this problem and successfully developed thin Ni $_{3}$ Al foils using directional solidification and cold rolling. We investigated the catalytic activities of the cold-rolled Ni $_{3}$ Al foils for methane steam reforming. The effect of steam pre-treatment on the catalytic activities of the foil was also investigated. It was found that the activity of as-rolled foils increased with temperature above 873 K, while no obvious activity was detected below 873 K. The steam pre-treatment at 873 K significantly enhanced the activity in the temperature range from 873 to 1173 K. The enhanced catalytic activity was attributed to the fine pure Ni particles on the foil formed by the steam pre-treatment.

口頭

Effect of steam treatments on surface morphology of Ni $_{3}$ Al foil catalysts

Xu, Y.*; Ma, Y.*; 櫻井惇也*; 寺岡有殿; 吉越章隆; 出村雅彦*; 平野敏幸*

no journal, ,

We found that Ni $_{3}$ Al shows high catalytic activity for methanol decomposition and methane steam reforming as catalysts of hydrogen production. It is possible to enhance catalytic activity by modifying the Ni $_{3}$ Al foil by a pre-steam treatment followed by a reduction with H $_{2}$ gas flow. We investigated the effect of the steam treatment and H $_{2}$ reduction on the surface morphology of Ni $_{3}$ Al foil using synchrotron radiation X-ray photoemission spectroscopy. Although the metallic Ni2p $_{3/2}$ and 2p $_{1/2}$ peaks were detected before the steam treatment, the metallic Ni was significantly decreased and NiO appeared after the steam treatment, suggesting that most of the metallic Ni was oxidized. After the hydrogen reduction, the metallic Ni increased again, indicating that the NiO was reduced. These fine metallic Ni particles formed on the foil surface contribute to the enhanced catalytic activity.

口頭

Oxidation of Ni $_{3}$ Al(210) surface at room temperature using supersonic oxygen molecular beam; Real-time photoemission spectroscopic study with synchrotron radiation

Syu, Y.*; 櫻井惇也*; 寺岡有殿; 吉越章隆; 出村雅彦*; 平野敏幸*

no journal, ,

Intermetallic compounds (IMCs) usually have ordered crystal structure which differs from that of their constitute metals. Some of them have been reported to show good catalytic properties for some reactions, such as Pt $_{3}$ Ti, Ni $_{3}$ Sn, and Ni $_{3}$ Al, demonstrating that IMCs have potential as catalysts and/or catalyst precursors for chemical reactions. In this work, we investigate the initial oxidation process on a Ni $_{3}$ Al(210) surface at 298 K using a supersonic oxygen molecular beam and a real-time photoemission spectroscopy with synchrotron radiation. The time evolutions of O 1s, Ni 2p, Al 2p, and Ni 3p spectra indicate that both Al and Ni are oxidized, and AlO $_{x}$ and NiO are formed during the irradiation of oxygen molecules. The oxidation rate of Al is much higher than that of Ni at the beginning of oxidation, and then quickly saturates. In contrast, the oxidation of Ni progresses gradually for the whole measured period.

口頭

Initial oxidation behavior of Ni $_{3}$ Al(210) surface induced by supersonic oxygen molecular beam at room temperature

Xu, Y.*; 出村雅彦*; 寺岡有殿; 吉越章隆; 櫻井惇也*; 平野敏幸*

no journal, ,

Ni $_{3}$ Al(210)表面の超音速O $_{2}$ 分子ビーム(2.3eV)による室温酸化を高輝度放射光を利用したリアルタイム光電子分光によって調べた。O 1s, Ni 2p, Al 2p, and Ni 3pスペクトルの分子ビーム照射中の時間発展を調べた。スペクトル分析から、表面のAlとNI原子の両方が酸化され、Alの酸化の方がNiより速いことがわかった。

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クリープ破断時間および高温引張強度予測モデルの連合学習

sparse-ir; Optimal compression and sparse sampling of many-body propagators

Spontaneous activation behavior of Ni $_{3}$ Sn, an intermetallic catalyst, for hydrogen production via methanol decomposition

Effect of water vapor and hydrogen treatments on the surface structure of Ni $_{3}$ Al foil

Catalytic performance of Ni $_{3}$ Sn and Ni $_{3}$ Sn $_{2}$ for hydrogen production from methanol decomposition

Catalytic performance of Ni $_{3}$ Sn alloy for hydrogen production from methanol decomposition

Post analysis of LOFC test Run2

Catalytic properties of Ni $_{3}$ Al foils for methane steam reforming

Effect of steam treatments on surface morphology of Ni $_{3}$ Al foil catalysts

Oxidation of Ni $_{3}$ Al(210) surface at room temperature using supersonic oxygen molecular beam; Real-time photoemission spectroscopic study with synchrotron radiation

Initial oxidation behavior of Ni $_{3}$ Al(210) surface induced by supersonic oxygen molecular beam at room temperature