The Experts below are selected from a list of 4344 Experts worldwide ranked by ideXlab platform

Hideki Yuya - One of the best experts on this subject based on the ideXlab platform.

  • investigation of electroMagnetic nondestructive evaluation of residual strain in low carbon steels using the eddy current Magnetic Signature ec ms method
    Journal of Magnetism and Magnetic Materials, 2019
    Co-Authors: Takanori Matsumoto, Tetsuya Uchimoto, Toshiyuki Takagi, Gerd Dobmann, Benjamin Ducharne, Shinji Oozono, Hideki Yuya
    Abstract:

    Abstract A novel Magnetic nondestructive testing method, that is named eddy current Magnetic Signature (EC-MS) method, is proposed to evaluate the residual strain in low carbon steels. This method relies on characterization of eddy current signals in the impedance plane if low frequency major magnetization is superimposed. To investigate the mechanism of the proposed method, the eddy current Magnetic Signatures of a set of tensile test specimens are measured, and their relationship to the residual strain is surveyed. The trajectories of the eddy current signals show significant dependences on the residual strain; the EC-MS changes depending on the three residual strain stages, the region just after elastic limit before yield point, the Luders-strain region, and the region after start of work hardening. The EC-MS under elastic strain/stress is measured to investigate the influence of stress on the EC-MS. Numerical calculation is performed considering micro-eddy current field associated with moving domain walls and compared with experimental results to interpret the EC-MS phenomena.

Takanori Matsumoto - One of the best experts on this subject based on the ideXlab platform.

  • investigation of electroMagnetic nondestructive evaluation of residual strain in low carbon steels using the eddy current Magnetic Signature ec ms method
    Journal of Magnetism and Magnetic Materials, 2019
    Co-Authors: Takanori Matsumoto, Tetsuya Uchimoto, Toshiyuki Takagi, Gerd Dobmann, Benjamin Ducharne, Shinji Oozono, Hideki Yuya
    Abstract:

    Abstract A novel Magnetic nondestructive testing method, that is named eddy current Magnetic Signature (EC-MS) method, is proposed to evaluate the residual strain in low carbon steels. This method relies on characterization of eddy current signals in the impedance plane if low frequency major magnetization is superimposed. To investigate the mechanism of the proposed method, the eddy current Magnetic Signatures of a set of tensile test specimens are measured, and their relationship to the residual strain is surveyed. The trajectories of the eddy current signals show significant dependences on the residual strain; the EC-MS changes depending on the three residual strain stages, the region just after elastic limit before yield point, the Luders-strain region, and the region after start of work hardening. The EC-MS under elastic strain/stress is measured to investigate the influence of stress on the EC-MS. Numerical calculation is performed considering micro-eddy current field associated with moving domain walls and compared with experimental results to interpret the EC-MS phenomena.

  • Numerical model of the eddy current Magnetic Signature (EC-MS) non-destructive micro-Magnetic technique
    AIP Advances, 2019
    Co-Authors: Takanori Matsumoto, B. Ducharne, Tetsuya Uchimoto
    Abstract:

    Micro-Magnetic nondestructive evaluation and testing techniques are particularly efficient for the evaluation of plastic strain in steel components. A new method derived from the Magnetic incremental permeability experimental setup and called Eddy Current Magnetic Signature (EC-MS) seems to be the particularly adapted for such evaluation. Numerical simulation of EC-MS has never been done before. In this article, the EC-MS method is described first, then a lump scalar phenomenological model based on a modified Jiles-Atherton model and extended to dynamic behavior is proposed for its simulation. All the simulation details are exposed and justified with physical observations.Micro-Magnetic nondestructive evaluation and testing techniques are particularly efficient for the evaluation of plastic strain in steel components. A new method derived from the Magnetic incremental permeability experimental setup and called Eddy Current Magnetic Signature (EC-MS) seems to be the particularly adapted for such evaluation. Numerical simulation of EC-MS has never been done before. In this article, the EC-MS method is described first, then a lump scalar phenomenological model based on a modified Jiles-Atherton model and extended to dynamic behavior is proposed for its simulation. All the simulation details are exposed and justified with physical observations.

Florent Szitkar - One of the best experts on this subject based on the ideXlab platform.

  • High-resolution Magnetic Signature of active hydrothermal systems in the back-arc spreading region of the southern Mariana Trough
    Journal of Geophysical Research: Solid Earth, 2015
    Co-Authors: Masakazu Fujii, Nobutatsu Mochizuki, Florent Szitkar, Jérôme Dyment, Chie Honsho, Kyoko Okino, Miho Asada
    Abstract:

    High-resolution vector Magnetic measurements were performed on five hydrothermal vent fields of the back-arc spreading region of the southern Mariana Trough using Shinkai 6500, a deep-sea manned submersible. A new 3-D forward scheme was applied that exploits the surrounding bathymetry and varying altitudes of the submersible to estimate absolute crustal magnetization. The results revealed that Magnetic-anomaly-derived absolute magnetizations show a reasonable correlation with natural remanent magnetizations of rock samples collected from the seafloor of the same region. The distribution of Magnetic-anomaly-derived absolute magnetization suggests that all five andesite-hosted hydrothermal fields are associated with a lack of magnetization, as is generally observed at basalt-hosted hydrothermal sites. Furthermore, both the Pika and Urashima sites were found to have their own distinct low-magnetization zones, which could not be distinguished in Magnetic anomaly data collected at higher altitudes by autonomous underwater vehicle due to their limited extension. The spatial extent of the resulting low magnetization is approximately 10 times wider at off-axis sites than at on-axis sites, possibly reflecting larger accumulations of nonMagnetic sulfides, stockwork zones, and/or alteration zones at the off-axis sites.

  • the Magnetic Signature of ultramafic hosted hydrothermal sites
    Geology, 2014
    Co-Authors: Florent Szitkar, Jérôme Dyment, Chie Honsho, Yves Fouquet, Helene Horen
    Abstract:

    Unlike basalt-hosted hydrothermal sites, characterized by a lack of magnetization, the Magnetic Signature of ultramafic-hosted hydrothermal sites remains poorly known, despite their wide occurrence at slow-spreading ridges and their strong mineral potential. The first high-resolution Magnetic surveys of such ultramafic-hosted sites, achieved by deep-sea submersible on four sites of the Mid-Atlantic Ridge, reveal positive Magnetic anomalies, and therefore a strong magnetization at the largest sites. This observation reflects the presence of a wide mineralized zone beneath these sites, the stockwork, where several chemical processes concur to create and preserve strongly magnetized magnetite. Beyond pointing out the importance of subsurface chemical processes in hydrothermal activity, the aging of oceanic lithosphere, and the ocean chemical budget, our results have immediate application for detecting and characterizing economically valuable deep-sea mineral deposits.

  • What causes low magnetization at basalt-hosted hydrothermal sites? Insights from inactive site Krasnov (MAR 16°38′N)
    Geochemistry Geophysics Geosystems, 2014
    Co-Authors: Florent Szitkar, Jérôme Dyment, Yujin Choi, Yves Fouquet
    Abstract:

    High-resolution Magnetic surveys acquired near the seafloor show that active basalt-hosted hydrothermal sites are associated with zones of lower magnetization. This observation may reflect the thermal demagnetization of a hot hydrothermal zone, the alteration of basalt affected by hydrothermal circulation, and/or the presence of thick, nonMagnetic hydrothermal deposits. In order to discriminate among these inferences, we acquired vector Magnetic data 50 m above inactive hydrothermal site Krasnov using the Remotely Operated Vehicle (ROV) Victor. This deep hydrothermal site, located 7 km east of the Mid-Atlantic Ridge (MAR) axis at 16°38′N, is dissected by major normal faults and shows no evidence of recent hydrothermal activity. It is therefore a perfect target for investigating the Magnetic Signature of an inactive basalt-hosted hydrothermal site. Krasnov exhibits a strong negative Magnetic anomaly, which implies that the lower magnetization observed at basalt-hosted hydrothermal sites is not a transient effect associated with hydrothermal activity, but remains after activity ceases. Thermal demagnetization plays only a secondary role, if any, in the observed Magnetic low. Forward models suggest that both the nonMagnetic hydrothermal deposits and an altered zone of demagnetized basalt are required to account for the observed Magnetic low. The permanence of this Magnetic Signature makes it a useful tool to explore midocean ridges and detect inactive hydrothermal sites.

Tetsuya Uchimoto - One of the best experts on this subject based on the ideXlab platform.

  • investigation of electroMagnetic nondestructive evaluation of residual strain in low carbon steels using the eddy current Magnetic Signature ec ms method
    Journal of Magnetism and Magnetic Materials, 2019
    Co-Authors: Takanori Matsumoto, Tetsuya Uchimoto, Toshiyuki Takagi, Gerd Dobmann, Benjamin Ducharne, Shinji Oozono, Hideki Yuya
    Abstract:

    Abstract A novel Magnetic nondestructive testing method, that is named eddy current Magnetic Signature (EC-MS) method, is proposed to evaluate the residual strain in low carbon steels. This method relies on characterization of eddy current signals in the impedance plane if low frequency major magnetization is superimposed. To investigate the mechanism of the proposed method, the eddy current Magnetic Signatures of a set of tensile test specimens are measured, and their relationship to the residual strain is surveyed. The trajectories of the eddy current signals show significant dependences on the residual strain; the EC-MS changes depending on the three residual strain stages, the region just after elastic limit before yield point, the Luders-strain region, and the region after start of work hardening. The EC-MS under elastic strain/stress is measured to investigate the influence of stress on the EC-MS. Numerical calculation is performed considering micro-eddy current field associated with moving domain walls and compared with experimental results to interpret the EC-MS phenomena.

  • Numerical model of the eddy current Magnetic Signature (EC-MS) non-destructive micro-Magnetic technique
    AIP Advances, 2019
    Co-Authors: Takanori Matsumoto, B. Ducharne, Tetsuya Uchimoto
    Abstract:

    Micro-Magnetic nondestructive evaluation and testing techniques are particularly efficient for the evaluation of plastic strain in steel components. A new method derived from the Magnetic incremental permeability experimental setup and called Eddy Current Magnetic Signature (EC-MS) seems to be the particularly adapted for such evaluation. Numerical simulation of EC-MS has never been done before. In this article, the EC-MS method is described first, then a lump scalar phenomenological model based on a modified Jiles-Atherton model and extended to dynamic behavior is proposed for its simulation. All the simulation details are exposed and justified with physical observations.Micro-Magnetic nondestructive evaluation and testing techniques are particularly efficient for the evaluation of plastic strain in steel components. A new method derived from the Magnetic incremental permeability experimental setup and called Eddy Current Magnetic Signature (EC-MS) seems to be the particularly adapted for such evaluation. Numerical simulation of EC-MS has never been done before. In this article, the EC-MS method is described first, then a lump scalar phenomenological model based on a modified Jiles-Atherton model and extended to dynamic behavior is proposed for its simulation. All the simulation details are exposed and justified with physical observations.

Yves Fouquet - One of the best experts on this subject based on the ideXlab platform.

  • the Magnetic Signature of ultramafic hosted hydrothermal sites
    Geology, 2014
    Co-Authors: Florent Szitkar, Jérôme Dyment, Chie Honsho, Yves Fouquet, Helene Horen
    Abstract:

    Unlike basalt-hosted hydrothermal sites, characterized by a lack of magnetization, the Magnetic Signature of ultramafic-hosted hydrothermal sites remains poorly known, despite their wide occurrence at slow-spreading ridges and their strong mineral potential. The first high-resolution Magnetic surveys of such ultramafic-hosted sites, achieved by deep-sea submersible on four sites of the Mid-Atlantic Ridge, reveal positive Magnetic anomalies, and therefore a strong magnetization at the largest sites. This observation reflects the presence of a wide mineralized zone beneath these sites, the stockwork, where several chemical processes concur to create and preserve strongly magnetized magnetite. Beyond pointing out the importance of subsurface chemical processes in hydrothermal activity, the aging of oceanic lithosphere, and the ocean chemical budget, our results have immediate application for detecting and characterizing economically valuable deep-sea mineral deposits.

  • What causes low magnetization at basalt-hosted hydrothermal sites? Insights from inactive site Krasnov (MAR 16°38′N)
    Geochemistry Geophysics Geosystems, 2014
    Co-Authors: Florent Szitkar, Jérôme Dyment, Yujin Choi, Yves Fouquet
    Abstract:

    High-resolution Magnetic surveys acquired near the seafloor show that active basalt-hosted hydrothermal sites are associated with zones of lower magnetization. This observation may reflect the thermal demagnetization of a hot hydrothermal zone, the alteration of basalt affected by hydrothermal circulation, and/or the presence of thick, nonMagnetic hydrothermal deposits. In order to discriminate among these inferences, we acquired vector Magnetic data 50 m above inactive hydrothermal site Krasnov using the Remotely Operated Vehicle (ROV) Victor. This deep hydrothermal site, located 7 km east of the Mid-Atlantic Ridge (MAR) axis at 16°38′N, is dissected by major normal faults and shows no evidence of recent hydrothermal activity. It is therefore a perfect target for investigating the Magnetic Signature of an inactive basalt-hosted hydrothermal site. Krasnov exhibits a strong negative Magnetic anomaly, which implies that the lower magnetization observed at basalt-hosted hydrothermal sites is not a transient effect associated with hydrothermal activity, but remains after activity ceases. Thermal demagnetization plays only a secondary role, if any, in the observed Magnetic low. Forward models suggest that both the nonMagnetic hydrothermal deposits and an altered zone of demagnetized basalt are required to account for the observed Magnetic low. The permanence of this Magnetic Signature makes it a useful tool to explore midocean ridges and detect inactive hydrothermal sites.