Superconductivity and carbon nanotubes, are Type I, while almost all impure and compound superconductors are Type II. Conversely, a spinning superconductor generates a magnetic field, precisely aligned with the spin axis. The effect, the London moment, was put to good use in Gravity Probe B. This experiment measured the magnetic fields of four superconducting gyroscopes to determine their spin axes. This was critical to the experiment since it is one of the few ways to accurately determine the spin axis of an otherwise featureless sphere. Superconductivity was discovered on April 8, 1911 by Heike Kamerlingh Onnes, who was studying the resistance
Heike Erkers of employers performing salary surveys (lönekartläggning) on a regular basis. Another issue is child poverty. She is also a member of the Executive Committee of the European Federation of Public Service Unions (EPSU) Heike Erkers Heike Erkers is the Chair of the Swedish labour union Akademikerförbundet SSR (in English 'The Union for Professionals'). She is currently off duty from her regular employment as a head of department at the Swedish Public Employment Service (in Swedish 'Arbetsförmedlingen'). Heike Erkers started being in enganged in labour union issues in the 1990s. In 2003 she was elected member of the board of Akademikerförbundet