Liquid helium of liquid water. Helium was first liquefied on July 10, 1908, by the Dutch physicist Heike Kamerlingh Onnes at the University of Leiden in the Netherlands. At that time, helium-3 was unknown because the mass spectrometer had not yet been invented. In more recent decades, liquid helium has been used as a cryogenic refrigerant, and liquid helium is produced commercially for use in superconducting magnets such as those used in magnetic resonance imaging (MRI), nuclear magnetic resonance (NMR), Magnetoencephalography (MEG), and experiments in physics, such as low temperature Mössbauer spectroscopy. The temperature required to produce liquid helium is low because
Heike Erkers 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 SSR, she became First Vice-Chair in 2006, and on 13 May 2012 she was elected Chair. As Chair of Akademikerförbundet SSR, Heike Erkers has, among other things, argued in favour of the value