Research activity information

• Numerical Simulation of Seawater Flows and Electrolysis in a MHD-based Oil Separator

  NAKAMOTO YUYA, AKAZAWA TERUHIKO, IWAMOTO YUJI, UMEDA TAMIKI

  Oct. 2010, Proceedings of Techno-Ocean 2010 (CD-ROM), English

  International conference proceedings

• Research and development of basic technologies for hydrogen energy maritime transportation -Construction of liquid hydrogen experiment facility with observation system-

  武田 実, 赤澤 輝彦, 岩本 雄二, 前川 政範, 風間 力

  Jul. 2005, Review of the Faculty of Maritime Sciences, Kobe University, 第2号, pp.171-177, Japanese

  Report scientific journal

  Link to Kobe Univ. Repository (Kernel)

• Separation of fish eggs from seawater by using a Lorentz-forece-type separator

  AKAZAWA TERUHIKO, UEMURA NOKI, IWAMOTO YUJI, UMEDA TAMIKI

  第96回 低温工学・超電導学会研究発表会, May 2018, Japanese, タワーホール船堀, Domestic conference

  Oral presentation


• The relation between the seawater flow and cross-section shape of channel of Lorentz-Force-type seawater-oil separator

  AKAZAWA TERUHIKO, IWATAYUKI, NAGATOMO YUKI, IWAMOTO YUJI, UMEDA TAMIKI

  第89回低温工学・超電導学会研究発表会, May 2014, Japanese, タワーホール船堀, Domestic conference

  Oral presentation

• 日本物理学会

• マイクロプラスチック海洋汚染に対応する電磁力を利用した浄化法の確立

  赤澤 輝彦, 岩本 雄二

  日本学術振興会, 科学研究費助成事業, 基盤研究(C), 神戸大学, 01 Apr. 2024 - 31 Mar. 2027


• Development of electromagnetic force-type seawater-purification-unit for ballast water

  赤澤 輝彦, 梅田 民樹, 岩本 雄二, 長松 隆, 青木 誠, 細井 祥子

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Kobe University, 01 Apr. 2019 - 31 Mar. 2023

  これまでは分離器を流れる海水の流れ場について注目をおいた研究が行なわれてきた．一方，分離物の移動距離評価に用いる分離対象物にはたらく海水の反力は，海水にかかるローレンツ体積力の単純な浮力として取り扱われていた．我々は2次元流体を用いて海水から分離対象物にはたらく反力が単純な浮力ではないことを示し，従来から考えられていた分離力メカニズムでは本手法の分離は理解できないことを明らかにした．さらに，3次元流体モデルを用いて，分離対象物と海水の伝導率の違いにより生ずる電場の歪によって，分離対象物まわりに局所的な海水流れが生じる．この局所海水流れの効果によって分離対象物に海水から力が働いていることを示した．分離対象物を球形な絶縁体と仮定した場合，従来考えられていた反力の6割程度の力が局所的な海水流れにより絶縁体球に作用することがわかった．次に，局所流れによる相互作用を考えるため2つの球状絶縁体間にはたらく相互作用を検討したところ，絶縁球の移動方向には引力，磁場および電場方向には斥力がはたらくことがわかった．分離対象物の距離が近ければ分離方向に移動する速さは大きくなることも数値シミュレーションからわかった． 実験面では，電磁場中での複数の不導体球がどのように振る舞うかについて光学観測できる実験装置を新たに作製し光学観測実験を行った．作製した実験装置は磁場方向からしか観測できないためまだ詳細な検討は必要であるが，理論面で示唆された電場方向に斥力が働いているようには見られなかった．電極板表面の電気分解で生じる気泡（マイクロバブル）により上昇流が発生するため数値計算結果とズレが生じたためではないかと考えられる．これまで検討されていなかった分離装置内で発生する気泡の効果も分離性能の向上には考慮する必要があることがわかってきた．


• 海水中のマイクロバブルの電場・磁場による流動制御

  梅田 民樹

  学術研究助成基金助成金／挑戦的萌芽研究, Apr. 2014 - Mar. 2017

  Competitive research funding


• ゼロ熱膨張率物質を用いた極限環境下材料の基礎的研究

  岩本 雄二

  科学研究費補助金／萌芽研究, Apr. 2012 - Mar. 2014, Principal investigator

  Competitive research funding


• ＭＨＤを応用した新しい海水・油分離装置の開発

  赤澤 輝彦

  科学研究費補助金／基盤研究(B), 2009

  Competitive research funding


• NMR Study of Pressure-induced Superconductivity and Pressure-induced Weak Magnetism in f-electron Systems

  KOHARA Takao, IWAMOTO Yuji, UEDA Koh-ichi, KOHORI Yoh, MATSUDA Kazuyuki

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Himeji Institution of Technology, 2000 - 2001

  The main purpose of this subject is for exploring the mechanisms of unconventional superconductivity and a tiny magnetic moment induced by applied high pressure in f-electron compounds. This project consists of two-sample groups; (1) pressure induced superconductors of CeTIn_5 (T= Rh, Co, Ir) and CeRh_2Si_2 and (2) Uru_2Si_2 with tiny magnetic moments. Present ^<115>NQR measurements in the super conducting state were performed on CeCoIn_5, Celrln_5 and CeRhln_5 under high pressure above the critical pressure of 1.7GPa. As for CeTIn_5 in the super conducting state, the nuclear magnetic relaxation rate has T^3 -dependence and the spin susceptibility decreases upon cooling. These results indicate that these systems exhibit d-wave superconductivity. On the other hand, CeCoIn_5 in the normal state is located just at antiferromagnetic instability and CeRhln_5 above the critical pressure and Celrln_5 are in the nearly antiferromagnetic region. Next, we have found new ^<29>Si NMR signals coming from the antiferromagnetic region in Uru_2Si_2 together with previously reported Si NMR signals from the paramagnetic region. These signal-intensities compete with each other depending on temperature and applied pressure. This result gives evidence for spatially inhomogeneous development of antiferromagnetic ordering below characteristic temperature. The ordered magnetic moments of U are expected as about 0.4 μ, B, which is of about one order of magnitude larger than 0.03 μ B measured by many neutron diffraction experiments. This picture of inhomogeneous development of antiferromagnetic region will bring us to the new scenario of understanding of hidden order parameters, which is still unsolved since the discovery of this interesting material in '85.


• MQR Study of Pressure induced Superconductivity in Antiferromagnetic Ce Compound.

  KOHARA Takao, IWAMOTO Yuji, UEDA Koh-ichi, KOHORI Yoh

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Himeji Institute of Technology, 1998 - 1999

  The main purpose of this subject is for the design of high pressure cell used for the NMR/NQR measurement at low temperatures and the NMR/NQR measurement of the constituted nuclei in the pressure-Induced superconductors. In the antiferromagnetic dense-Kondo compound CeInィイD23ィエD2 (TィイD2NィエD2=10 K), a small internal field (6 kOe at 1.6 K), which is parallel to the respective Ce-In planes, appears. The non-vanishing ィイD1115ィエD1In internal field means that Ce magnetic moments orient perpendicular to the (111) plans. With applied pressure, the internal field gradually decreases and disappears above 2.44 Gpa. The nuclear spin-lattice relaxation rate, 1/TィイD21ィエD2, is nearly temperature independent in the paramagnetic state and is strongly suppressed with increasing pressure. On further cooling through TィイD2NィエD2, 1/TィイD21ィエD2 decreases rapidly with no critical slowing down phenomena at TィイD2NィエD2 and varies in proportional to temperature at very low temperatures. Fermi liquid behavior was observed below 10 K at 2.74 Gpa. The NMR/NQR on other interesting pressure-induced superconductors such as CePdィイD22ィエD2SiィイD22ィエD2, CeNiィイD22ィエD2GeィイD22ィエD2 and CeRhInィイD25ィエD2 are also now in progress.