Yazar "Yanmaz, E." seçeneğine göre listele

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    Comparative study of the magnetic stiffness, levitation and guidance force properties of single and multi seeded YBCOs for different HTS-PMG arrangements
    (Elsevier Science Sa, 2015) Ozturk, K.; Sahin, E.; Abdioglu, M.; Kabaer, M.; Celik, S.; Yanmaz, E.; Kucukomeroglu, T.
    It is crucial to improve the magnetic levitation, guidance and stiffness performances of the HTS Maglev systems for real-scale applications. In this study, the magnetic levitation force, guidance force and magnetic stiffness values were determined for single and multi-seeded YBCOs on different PMGs in ZFC regime and different cooling heights (CHs) after the magnetic flux distributions simulation of the using PMGs. Implemented study showed that the additional downward PMs make an enhancing contribution on the magnetic levitation force, guidance force and magnetic stiffness of both single and multi-seeded YBCOs. It was also determined that both the force and stiffness ratios of multi-seeded YBCO to single-seeded YBCO increase with increasing CH, indicating that the multi-seeded YBCO has much more interaction domain than single-seeded at higher gaps. It is considered that the results obtained in this study are very useful in technological applications of Maglev and bearing systems, because there is no detailed study on the magnetic stiffness, levitation and guidance force comparison to clarify electromagnetic behavior of single and multi-seeded YBCOs for different HTS-PMG arrangements. (C) 2015 Elsevier B.V. All rights reserved.
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    Effect of Adding on the Critical Current Density and Lateral Levitation Force of Bulk
    (Springer/Plenum Publishers, 2015) Savaskan, B.; Koparan, E. Taylan; Guner, S. B.; Celik, S.; Ozturk, K.; Yanmaz, E.
    We fabricated malic acid -added bulks by wet mixing and Two-step solid state reaction method. The effects of adding malic acid on , behaviour and lateral levitation force features of bulk have been investigated. A systematic decrease in the critical temperature with increasing adding level confirms the substitution of C at the B site of . While the 4 wt% sample showed the best of at 4 T and 5 K, 15 wt% sample showed uncompetitive lower critical current density , which ascribes the poor connectivity due to the excessive unsubstituted C distribution at grain boundaries and the presence of high MgO amount. At 24 and 28 K, the 4 and 6 wt% malic-acid-added samples exhibit a higher lateral force than pure sample. Based on the observed values of M-H, (H) and lateral levitation force , it can be concluded that the 4 wt% malic-acid-added sample is the best of the studied samples.
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    Öğe
    The size effect on the magnetic levitation force of MgB2 bulk superconductors
    (Elsevier Sci Ltd, 2016) Savaskan, B.; Koparan, E. T.; Guner, S. B.; Celik, S.; Yanmaz, E.
    In this study, the size effect on the magnetic levitation performance of disk-shaped MgB2 bulk superconductors and permanent magnets was investigated. MgB2 samples with varying diameters of 13 mm, 15 mm and 18 mm, each of which were 2 g in mass, were prepared by two-step solid state reaction method. Vertical levitation force measurements under both zero-field-cooled (ZFC) and field-cooled (FC) regimes were carried out at different temperatures of 20, 24 and 28 K. It was determined that the levitation force of the MgB2 strongly depends on both the diameters of the sample and the permanent magnet. In ZFC regime, the maximum levitation force value for the permanent magnet and the sample 18 mm in diameters reached to the 8.41 N at 20 K. In addition, in FC regime, attractive and repulsive force increased with increasing diameters of the sample and the permanent magnet. In that, the sample with 18 mm in diameter showed the highest attractive force value -3.46 N at 20 K and FC regime. The results obtained in this study are very useful in magnetic levitation devices as there is no detailed study on the size of superconductors and permanent magnets. (C) 2016 Elsevier Ltd. All rights reserved.