![Chapter S24](http://s1.studyres.com/store/data/008769694_1-0e0fa2e24dc83dcea9381cc907e64436-300x300.png)
Electric charge
... fields are dominant. Smaller extent of universal medium, between electric fields at close range, is unable to produce large inertial efforts due to changes in distortion-density. At the same time, distortion-fields at the sides are strong enough to produce required differences in distortion-density ...
... fields are dominant. Smaller extent of universal medium, between electric fields at close range, is unable to produce large inertial efforts due to changes in distortion-density. At the same time, distortion-fields at the sides are strong enough to produce required differences in distortion-density ...
Controlling Vortex Pinning and Dynamics of Solution Deposition
... him the refrigeration technique required to reach temperatures of a few degrees Kelvin. He measured the mercury resistivity at low temperatures and observed that at 4.15K, the resistivity dropped to zero since the material became superconductor, avoiding the electrical resistance (perfect conductivi ...
... him the refrigeration technique required to reach temperatures of a few degrees Kelvin. He measured the mercury resistivity at low temperatures and observed that at 4.15K, the resistivity dropped to zero since the material became superconductor, avoiding the electrical resistance (perfect conductivi ...
15_rev_final
... temperature distribution evolves inside the YBCO coil when it quenches and how rapidly the current can be decreased to zero with an external dump resistor circuit. Due to the small energy stored in the insert, we considered only the external dump resistor circuits for the protection. We did not inc ...
... temperature distribution evolves inside the YBCO coil when it quenches and how rapidly the current can be decreased to zero with an external dump resistor circuit. Due to the small energy stored in the insert, we considered only the external dump resistor circuits for the protection. We did not inc ...
Germain ROUSSEAUX
... It is true that Ampère’s formula is no more admissible today, because it is based on the Newtonian idea of instantaneous action at a distance and it leads notably to the strange consequence that two consecutive elements of the same current should repel each other. Ampère presumed to have demonstrate ...
... It is true that Ampère’s formula is no more admissible today, because it is based on the Newtonian idea of instantaneous action at a distance and it leads notably to the strange consequence that two consecutive elements of the same current should repel each other. Ampère presumed to have demonstrate ...
Superconductivity
![](https://commons.wikimedia.org/wiki/Special:FilePath/Meissner_effect_p1390048.jpg?width=300)
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature. It was discovered by Dutch physicist Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of perfect conductivity in classical physics.The electrical resistivity of a metallic conductor decreases gradually as temperature is lowered. In ordinary conductors, such as copper or silver, this decrease is limited by impurities and other defects. Even near absolute zero, a real sample of a normal conductor shows some resistance. In a superconductor, the resistance drops abruptly to zero when the material is cooled below its critical temperature. An electric current flowing through a loop of superconducting wire can persist indefinitely with no power source.In 1986, it was discovered that some cuprate-perovskite ceramic materials have a critical temperature above 90 K (−183 °C). Such a high transition temperature is theoretically impossible for a conventional superconductor, leading the materials to be termed high-temperature superconductors. Liquid nitrogen boils at 77 K, and superconduction at higher temperatures than this facilitates many experiments and applications that are less practical at lower temperatures.