INFLUENCE OF WAITING TIME ON THE LEVITATION FORCE BETWEEN A PERMANENT MAGNET AND A SUPERCONDUCTOR

2008 ◽  
Vol 22 (07) ◽  
pp. 499-506 ◽  
Author(s):  
XING-YI ZHANG ◽  
YOU-HE ZHOU ◽  
JUN ZHOU
Keyword(s):  
Permanent Magnet ◽  
Liquid Nitrogen ◽  
Waiting Time ◽  
Levitation Force ◽  
Liquid Nitrogen Temperature ◽  
Zero Field ◽  
Bulk Superconductors ◽  
Growth Method ◽  
Ndfeb Permanent Magnet ◽  
Ybacuo Bulk

This paper describes the experimental results of the levitation force of single-grained YBaCuO bulk superconductors preparing by the top-seeded melt-growth method with different waiting time tw below an NdFeB permanent magnet. It was found that waiting time has large effects on the zero-field-cooled (ZFC) and field-cooled (FC) levitation force, and the levitation force shows aging characteristics at the liquid nitrogen temperature.

The Effect of the Distance between the Permanent Magnets on the Levitation Force in Hybrid Magnetic Levitation System

2013 ◽  
Vol 721 ◽  
pp. 278-281
Author(s):  
Jun Ma
Keyword(s):  
Permanent Magnet ◽  
Liquid Nitrogen ◽  
Permanent Magnets ◽  
Magnetic Levitation ◽  
Levitation Force ◽  
Liquid Nitrogen Temperature ◽  
Interaction Force ◽  
Bulk Superconductors ◽  
Levitation System ◽  
Magnetic Levitation System

t has been investigated that the interaction force in hybrid magnetic levitation systems with two GdBCO bulk superconductors and two permanent magnets system and a cubic permanent magnet (PM2) and a cubic permanent magnet (PM3) system in their coaxial configuration at liquid nitrogen temperature. The two single-domain GdBCO samples are of φ20mm and 10mm in thickness, the permanent magnet PM1 is of rectangular parallelepiped shape, the permanent magnets PM2 and PM3 are of cubic shape; the system placed on the middle of system and their coaxial configuration; It is found that the maximum levitation force decreases from 40.6N to 17.8N while the distance (Dpp) between the permanent magnets is increased from 0mm to 24mm and the distance (Dsp) between the two GdBCO bulk superconductors and a cubic permanent magnet PM3 is 0mm, The results indicate that the higher levitation force can be obtained by introducing PM-PM levitation system based on scientific and reasonable design of the hybrid magnetic levitation system, which is helpful for designing and constructing superconducting magnetic levitation systems.

Effect of the Moving Speed between Magnet and Superconductor on the Levitation Force of Single-Domain YBCO Bulk

2007 ◽  
Vol 546-549 ◽  
pp. 2107-2110
Author(s):  
S.H. Zhu ◽  
W.M. Yang ◽  
X.L. Wu ◽  
J.Z. Guo ◽  
T.N. Lu ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Liquid Nitrogen ◽  
Levitation Force ◽  
Liquid Nitrogen Temperature ◽  
Single Domain ◽  
Attractive Force ◽  
Distance Curve ◽  
Ybco Bulk ◽  
Moving Speed

The effect of the moving speed between a permanent magnet and a superconductor on the levitation force of single-domain YBCO bulk has been studied at liquid nitrogen temperature. It is found that the levitation force is much different with different moving speed, the maximum levitation force and the stiffness of the force-distance curve are increasing first and then decreasing with the increasing of the moving speed and, there is a reasonable speed to get the maximum levitation force. It is also found that the maximum attractive force is decreasing with the increasing of the moving speed.

Superconducting Properties of YBaCuO Bulk Superconductors

2019 ◽  
Vol 14 (12) ◽  
pp. 1755-1758 ◽  
Author(s):  
Sang Heon Lee
Keyword(s):  
High Temperature ◽  
Large Scale ◽  
High Temperature Superconductor ◽  
High Temperature Superconductivity ◽  
Liquid Nitrogen Temperature ◽  
Industrial Applications ◽  
Power Cables ◽  
Ceramic Superconductors ◽  
Bulk Superconductors ◽  
Ybacuo Bulk

The use of a high-temperature superconductor to manufacture products for commercialization requires a superconductor with a flexible function designed to meet the characteristics of each product. Appropriate mechanical properties need to be maintained to overcome the Lorenz force generated under high magnetic fields. Several studies focused on the improvement of superconductivity and the development of processing technology. However, high temperature superconductivity wires are not intended for large-scale applications at liquid nitrogen temperature (77 K). Recently, ceramic superconductors have been fabricated into bulk and thin films or wire rods for electric power applications; however, ceramics are hard to deform due to increased hardness, which is one of the biggest limitations of a superconductor, and a major obstacle to industrial applications. To overcome these limitations, a synthetic method for superconductivity to reduce the hardness of ceramic superconductor and prevent its degradation was proposed for applications such as superconductivity power cables and wires in energy and electric machines using superconductors.

The Effect of the Horizontal Distance between the Permanent Magnets on the Levitation Force in Hybrid Magnetic Levitation System

2013 ◽  
Vol 750-752 ◽  
pp. 987-990
Author(s):  
Jun Ma
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Magnetic Levitation ◽  
Levitation Force ◽  
Liquid Nitrogen Temperature ◽  
Horizontal Distance ◽  
Bulk Superconductor ◽  
Magnet System ◽  
Levitation System ◽  
Magnetic Levitation System

It has been investigated that the interaction force in hybrid magnetic levitation systems with a GdBCO bulk superconductor and a permanent magnet system and two permanent magnets (PM2) and two cubic permanent magnets (PM3) system in their coaxial configuration at liquid nitrogen temperature. A single-domain GdBCO sample is of 20mm and 10mm in thickness, the permanent magnet PM1 is of rectangular parallelepiped shape, the permanent magnets PM2 and PM3 are of cubic shape; the system placed on the middle of system and their coaxial configuration; It is found that the maximum levitation force decreases from 46.3N to 16.3N while the horizontal distance (Dpp) between the rectangle permanent magnet and two cubic permanent magnets (PM2) is increased from 0mm to 24mm and the horizontal distance (Dsp) between a GdBCO bulk superconductor and two cubic permanent magnets (PM3) is 0mm, The results indicate that the higher levitation force can be obtained by introducing PM-PM levitation system based on scientific and reasonable design of the hybrid magnetic levitation system, which is helpful for designing and constructing superconducting magnetic levitation systems.

Tensile testing method for rare earth based bulk superconductors at liquid nitrogen temperature

2005 ◽  
Vol 426-431 ◽  
pp. 639-643 ◽  
Author(s):  
K. Kasaba ◽  
K. Katagiri ◽  
A. Murakami ◽  
G. Sato ◽  
T. Sato ◽  
...  
Keyword(s):  
Rare Earth ◽  
Liquid Nitrogen ◽  
Tensile Testing ◽  
Liquid Nitrogen Temperature ◽  
Testing Method ◽  
Bulk Superconductors

scholarly journals Attraction and repulsion forces in melt-textured and sintered YBCO-superconductors: a comparative study

2020 ◽  
pp. 44-50
Author(s):  
Diego Andrés Arias-Arana ◽  
Juan Diego Rojas-Zambrano ◽  
Álvaro Mariño-Camargo
Keyword(s):  
Low Cost ◽  
Sintered Sample ◽  
Interaction Force ◽  
Solid State Reaction Method ◽  
Zero Field ◽  
Bulk Superconductors ◽  
Ybco Superconductors ◽  
Growth Method ◽  
Magnetic Flux Pinning ◽  
Field Cooling

In this paper, we measure the attraction (suspension) and repulsion (levitation) forces produced by the interaction between a permanent magnet and different bulk superconductors. The measurements of the interaction force HTS-PM were carried out with a relatively simple technique developed by us, which is reproducible, reliable and low cost. The obtained results were analyzed with the Bean’s critical-state model assuming a uniform magnetic field applied to the superconductor. Two superconducting samples of YBa2Cu3O7-δ (YBCO) prepared by solid-state reaction method and by the melt-textured growth method (MTG) were used. Both samples presented a different hysteresis behaviour in the field cooling (FC) and zero field cooling (ZFC) regimes. Levitation and suspension phenomena were observed in the MTG sample; however, the sintered sample (S) with Oxygen deficiencies (δ > 0.15) displayed a slight levitation force but did not show a suspension force, the latter one attributed to a more efficient magnetic flux pinning. Additionally, the critical current density of both samples was determined from the maximum gap of the force (ΔF) in the FC regime. The obtained values were between 43.00 A/cm2 and 2,758 A/cm2 for the sintered and MTG samples, respectively. These values show a remarkable difference between sintered and MTG samples like that observed from magnetization measurements, which indicate that attraction and repulsion force measurements could provide a rapid and reliable characterization method of polycrystalline superconducting samples.  

scholarly journals LEVITATION AND SUSPENSION FORCES MEASUREMENT SYSTEM FOR HIGH TC SUPERCONDUCTORS

MOMENTO ◽  
2020 ◽  
pp. 55-66 ◽  
Author(s):  
Juan D. Rojas ◽  
Diego A. Arias ◽  
Alvaro Mariño
Keyword(s):  
Levitation Force ◽  
Low Cost ◽  
Hysteresis Loops ◽  
Solid State Reaction Method ◽  
Zero Field ◽  
High Tc Superconductors ◽  
Interaction Forces ◽  
High Tc ◽  
Large Hysteresis ◽  
Growth Method

The interaction forces, attraction (suspension) and repulsion (levitation) between a permanent magnet and diferent bulk Yttrium-based superconductors were carried out with an automatic system developed in our group, which is reproducible, reliable and low cost. Two superconducting samples of YBa2Cu3O7-δ (YBCO) prepared by solid-state reaction method (S) and by the melt-textured growth method (MTG) were used. Both samples were characterized by XRD technique and presented the characteristic peaks and intensity relations of the YBCO-123 superconducting phase. Oxygen deficiencies δ > 0,15 and δ < 0,10 for the S and MTG samples respectively, were observed. Both samples displayed diferent hysteresis behavior in the Force (F) vs. Distance (z) measurements when they were field cooled (FC) and zero field cooled (ZFC). This behavior agrees with hysteresis loops observed in magnetization measurements. Both levitation and suspension phenomena were observed in the MTG sample with large hysteresis loops of the force. On the contrary, the S sample with small hysteresis loops did not show a suspension force, only displayed a slight levitation force.

Electron Probe Microanalysis of Frozen Hydrated Kidneys, Isolated Cells, and Cultured Cells

1982 ◽  
Vol 40 ◽  
pp. 402-403 ◽  
Author(s):  
Claude Lechene
Keyword(s):  
Liquid Nitrogen ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Cultured Cells ◽  
Liquid Nitrogen Temperature ◽  
Elemental Content ◽  
Isolated Cells ◽  
Renal Tubular Cells ◽  
Diamond Saw ◽  
Saw Blade

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.

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