Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 129

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Evaluation of the effect of composition and firing temperature on pore size distribution of ceramics by SANS measurement

Sugita, Tsuyoshi; Yoshida, Hirokazu*; Kodama, Hiroto*; Ishigaki, Toru*; Oba, Yojiro*

Journal of the Ceramic Society of Japan, 132(9), p.548 - 554, 2024/09

 Times Cited Count:1 Percentile:0.00(Materials Science, Ceramics)

Porosity plays an essential role in the performance of ceramics. In this study, the effects of clay composition and firing temperature on the pore size distribution of ceramics were evaluated by small-angle neutron scattering (SANS) measurements. Compared with quartz-rich pure Kasama clay, a mullite-rich Kasama clay blend had smaller pores after heat treatment. SANS measurements of D$$_{2}$$O-absorbed samples revealed that open pores with sizes ranging from tens of nanometers to about a micrometer contributed to the absorption of water. The closed and open pores coarsened and the total porosity decreased with increasing firing temperature.

Journal Articles

Nanocellulose hydrogels formed via crystalline transformation from cellulose I to II and subsequent freeze cross-linking reaction

Sekine, Yurina; Nankawa, Takuya; Hiroi, Kosuke; Oba, Yojiro*; Nagakawa, Yoshiyasu*; Sugita, Tsuyoshi; Shibayama, Yuki; Ikeda-Fukazawa, Tomoko*

Carbohydrate Polymers, 327, p.121538_1 - 121538_11, 2024/03

 Times Cited Count:2 Percentile:49.33(Chemistry, Applied)

We describe non-toxic, tough nanocellulose (NC) hydrogels formed from chemically unmodified NC by cellulose crystalline transformation and subsequent freeze cross-linking reaction. Using low-concentration NaOH and freezing together induced the crystalline transformation of NC from cellulose I to II via freeze concentration. After the crystalline transformation, cross-linking between the NC and CA in the freeze concentration layer (FCL) provided a strong NC network structure, forming NC hydrogels with high mechanical strength. The freeze-cross-linked NC hydrogel easily retained powder adsorbents in its inner space by mixing the NC-NaOH sol and the powder, and the hydrogel showed high removal efficiency for heavy metals. The results highlight the versatility of chemically unmodified celluloses in developing functional materials, suggest possible practical applications.

Journal Articles

New standard for low temperature sample environment at JAEA/JRR-3

Kaneko, Koji; Tabata, Chihiro; Hagihara, Masato; Yamauchi, Hiroki; Oba, Yojiro; Kumada, Takayuki; Kubota, Masato; Kojima, Yuki*; Nabatame, Nozomi; Sasaki, Miki; et al.

JPS Conference Proceedings (Internet), 41, p.011015_1 - 011015_6, 2024/03

Journal Articles

Upgrade of the small-angle neutron scattering diffractometer SANS-J at JRR-3

Kumada, Takayuki; Motokawa, Ryuhei; Oba, Yojiro; Nakagawa, Hiroshi; Sekine, Yurina; Micheau, C.; Ueda, Yuki; Sugita, Tsuyoshi; Birumachi, Atsushi; Sasaki, Miki; et al.

Journal of Applied Crystallography, 56(6), p.1776 - 1783, 2023/12

 Times Cited Count:10 Percentile:97.31(Chemistry, Multidisciplinary)

The combination of the existing position-sensitive photomultiplier and the $$^{3}$$He main detector with focusing devices, and the newly installed front detectors in SANS-J at JRR-3 covers small-angle neutron scattering signals in the range of the magnitude of the scattering vector Q from 0.002 to 6 nm-1 gaplessly with three standard device layouts. The installation of the front detector and a graphical user interface system largely improved the usability of SANS-J.

Journal Articles

Fingerprint of vortexlike flux closure in an isotropic Nd-Fe-B bulk magnet

Bersweiler, M.*; Oba, Yojiro; Sinaga, E. P.*; Peral, I.*; Titov, I.*; Adams, M. P.*; Rai, V.*; Metlov, K. L.*; Michels, A.*

Physical Review B, 108(9), p.094434_1 - 094434_7, 2023/09

 Times Cited Count:4 Percentile:68.65(Materials Science, Multidisciplinary)

Journal Articles

Neutron imaging technology and diverse applications; Observation of microstructures in Cu using Bragg edge imaging

Oba, Yojiro; Sasaki, Hirokazu*

Nihon Genshiryoku Gakkai-Shi ATOMO$$Sigma$$, 65(8), p.499 - 502, 2023/08

no abstracts in English

Journal Articles

Effect of annealing on the magnetic microstructure of high-pressure torsion iron; The Relevance of higher-order contributions to the magnetic small-angle neutron scattering cross section

Bersweiler, M.*; Sato, Hirokazu*; Adachi, Nozomu*; Todaka, Yoshikazu*; Peral, I.*; Kohlbrecher, J.*; Zaporozhets, V. D.*; Metlov, K. L.*; Michels, A.*; Oba, Yojiro

IUCrJ, 10(4), p.411 - 419, 2023/07

 Times Cited Count:2 Percentile:60.51(Chemistry, Multidisciplinary)

Journal Articles

Neutron resonance absorption imaging of simulated high-level radioactive waste in borosilicate glass

Oba, Yojiro; Motokawa, Ryuhei; Kaneko, Koji; Nagai, Takayuki; Tsuchikawa, Yusuke; Shinohara, Takenao; Parker, J. D.*; Okamoto, Yoshihiro

Scientific Reports (Internet), 13, p.10071_1 - 10071_8, 2023/06

 Times Cited Count:2 Percentile:65.72(Multidisciplinary Sciences)

Journal Articles

Magnetic structural analysis of nanocrystalline soft magnets by small-angle neutron scattering

Mamiya, Hiroaki*; Oba, Yojiro; Hiroi, Kosuke; Miyatake, Takayuki*; Gautam, R.*; Sepehri-Amin, H.*; Okubo, Tadakatsu*

IEEE Magnetics Letters, 14, p.7100105_1 - 7100105_5, 2023/02

 Times Cited Count:2 Percentile:49.60(Engineering, Electrical & Electronic)

Journal Articles

Microscopic structural changes during the freeze cross-linking reaction in carboxymethyl cellulose nanofiber hydrogels

Miura, Daisuke*; Sekine, Yurina; Nankawa, Takuya; Sugita, Tsuyoshi; Oba, Yojiro; Hiroi, Kosuke; Ozawa, Tatsuhiko

Carbohydrate Polymer Technologies and Applications (Internet), 4, p.100251_1 - 100251_9, 2022/12

The reaction mechanism of carboxymethyl cellulose nanofiber (CMCF) hydrogel formed by freeze-crosslinking was investigated. We succeeded in observing the hierarchical structural changes during the freeze-crosslinking reaction. Freeze-crosslinked CMCF hydrogels exhibited a characteristic hierarchical alignment structure from the angstrom to micrometer scale that differed from normal cross-linked CMCF hydrogels produced by a conventional method without freezing. It was shown that the characteristic hierarchical structure contributes the excellent mechanical properties of freeze-crosslinked CMCF hydrogels.

Journal Articles

Characterization of precipitated phase in Cu-Ni-Si alloy by small-angle X-ray scattering, small angle neutron scattering and atom probe tomography

Sasaki, Hirokazu*; Akiya, Shunta*; Oba, Yojiro; Onuma, Masato*; Giddings, A. D.*; Okubo, Tadakatsu*

Materials Transactions, 63(10), p.1384 - 1389, 2022/10

 Times Cited Count:0 Percentile:0.00(Materials Science, Multidisciplinary)

Journal Articles

Small-angle neutron scattering by spatially inhomogeneous ferromagnets with a nonzero average uniaxial anisotropy

Zaporozhets, V. D.*; Oba, Yojiro; Michels, A.*; Metlov, K. L.*

Journal of Applied Crystallography, 55(3), p.592 - 600, 2022/06

 Times Cited Count:8 Percentile:86.12(Chemistry, Multidisciplinary)

Journal Articles

Nanoscopic structure of borosilicate glass with additives for nuclear waste vitrification

Motokawa, Ryuhei; Kaneko, Koji; Oba, Yojiro; Nagai, Takayuki; Okamoto, Yoshihiro; Kobayashi, Taishi*; Kumada, Takayuki; Heller, W. T.*

Journal of Non-Crystalline Solids, 578, p.121352_1 - 121352_7, 2022/02

 Times Cited Count:4 Percentile:23.81(Materials Science, Ceramics)

Journal Articles

Characterization of deformation by cold rolling in ferritic steel containing Cu particles using neutron transmission analysis

Oba, Yojiro; Morooka, Satoshi; Oishi, Kazuki*; Suzuki, Junichi*; Tsuchiyama, Toshihiro*

ISIJ International, 62(1), p.173 - 178, 2022/01

 Times Cited Count:3 Percentile:31.34(Metallurgy & Metallurgical Engineering)

Journal Articles

Age-hardening mechanisms of heterogeneous-nanostructured SUS316LN stainless steel fabricated by heavy cold rolling

Miura, Hiromi*; Watanabe, Chihiro*; Aoyagi, Yoshiteru*; Oba, Yojiro; Kobayashi, Masakazu*; Yoshinaga, Naoki*

Materials Science & Engineering A, 833, p.142531_1 - 142531_12, 2022/01

 Times Cited Count:5 Percentile:48.28(Nanoscience & Nanotechnology)

Journal Articles

Nano-scale precipitates in Corson alloy during aging process characterized by in-situ small-angle X-ray scattering

Yamazaki, Satoshi*; Hirose, Kiyoshige*; Sasaki, Hirokazu*; Oba, Yojiro; Miyazawa, Tomotaka*; Onuma, Masato*

Do To Dogokin, 60(1), p.315 - 319, 2021/08

no abstracts in English

Journal Articles

Characterization of precipitated phase in Cu-Ni-Si alloy by small angle X-ray scattering, small angle neutron scattering and atom probe tomography

Sasaki, Hirokazu*; Akiya, Shunta*; Oba, Yojiro; Onuma, Masato*; Giddings, A. D.*; Okubo, Tadakatsu*

Do To Dogokin, 60(1), p.309 - 314, 2021/08

no abstracts in English

Journal Articles

Role of higher-order effects in spin-misalignment small-angle neutron scattering of high-pressure torsion nickel

Oba, Yojiro; Bersweiler, M.*; Titov, I.*; Adachi, Nozomu*; Todaka, Yoshikazu*; Gilbert, E. P.*; Steinke, N.-J.*; Metlov, K. L.*; Michels, A.*

Physical Review Materials (Internet), 5(8), p.084410_1 - 084410_9, 2021/08

 Times Cited Count:3 Percentile:16.67(Materials Science, Multidisciplinary)

Journal Articles

Development of spin-contrast-variation neutron powder diffractometry for extracting the structure factor of hydrogen atoms

Miura, Daisuke*; Kumada, Takayuki; Sekine, Yurina; Motokawa, Ryuhei; Nakagawa, Hiroshi; Oba, Yojiro; Ohara, Takashi; Takata, Shinichi; Hiroi, Kosuke; Morikawa, Toshiaki*; et al.

Journal of Applied Crystallography, 54(2), p.454 - 460, 2021/04

AA2020-0724.pdf:2.05MB

 Times Cited Count:1 Percentile:14.61(Chemistry, Multidisciplinary)

We developed a spin-contrast-variation neutron powder diffractometry technique that extracts the structure factor of hydrogen atoms, namely, the contribution of hydrogen atoms to a crystal structure factor. Crystals of L-glutamic acid were dispersed in a dpolystyrene matrix containing 4-methacryloyloxy-2,2,6,6,-tetramethyl-1-piperidinyloxy (TEMPO methacrylate) to polarize their proton spins dynamically. The intensities of the diffraction peaks of the sample changed according to the proton polarization, and the structure factor of the hydrogen atoms was extracted from the proton-polarization dependent intensities. This technique is expected to enable analyses of the structures of hydrogen-containing materials that are difficult to determine with conventional powder diffractometry.

Journal Articles

Revealing defect-induced spin disorder in nanocrystalline Ni

Bersweiler, M.*; Sinaga, E. P.*; Peral, I.*; Adachi, Nozomu*; Bender, P.*; Steinke, N.-J.*; Gilbert, E. P.*; Todaka, Yoshikazu*; Michels, A.*; Oba, Yojiro

Physical Review Materials (Internet), 5(4), p.044409_1 - 044409_7, 2021/04

 Times Cited Count:8 Percentile:44.63(Materials Science, Multidisciplinary)

129 (Records 1-20 displayed on this page)