RE: [Vo]:Tel Aviv Superconductor- Levitation
Hi Ron, Here is the page from Tel Aviv University: http://www.tau.ac.il/~supercon/ It is likely that the white disc is a composite sandwich of materials which is mostly (90%) merely a thermal insulator - possibly a white cloth or foam of some kind holding a 'supply' of LN for an extended time of operation. You can see a layer of the cloth which has become loosened in the video. Y123 is very dark in color as you know. Since the Group claims to specialize in making high quality 2-3 dia YBCO wafers, which are deposited on top of Sapphire in thin layers we can assume that the 'real' disc is thin and seen at the bottom, and most of the apparent volume which is seen is the white insulator material, giving the appearance of much more mass than is there in actuality. Since the mass is low the angular momentum problems are minimal at low speed. In addition - and most importantly - they claim to deposit the thing films at different crystallographic orientations, and with doping. This could provide the properties that give the unusual departure from normal flux pinning. Quote: Recent work, showed the possibility of making atomically flat a-axis grain of YBCO grown on top c-axis films . this means to me that the Y123 is oriented in perpendicular regions on top of each other to provide the kind of stability which is seen. Jones From: Ron Kita Subject: [Vo]:Tel Aviv Superconductor- Levitation Greetings Vortex, I haven t had a chance look for the superconductor material used in the levitation video, but it seems like this is not the usual flux pinning as experienced by 1-2-3 SC materials: http://en.wikipedia.org/wiki/Flux_pinning Ron Kita, Chiralex Few people realize that when one spins a symmetical magnet as a ring magnet- the flux lines remain stationary in space. This is the principle of the One Piece Farady Homopolar Generator.
Re: [Vo]:Tel Aviv Superconductor- Levitation
Jones Beene jone...@pacbell.net wrote: Here is the page from Tel Aviv University: ** ** http://www.tau.ac.il/~supercon/ ** ** It is likely that the white disc is a composite sandwich of materials which is mostly (90%) merely a thermal insulator - possibly a white cloth or foam of some kind holding a 'supply' of LN for an extended time of operation. I thought it was solid nitrogen. I thought the person asking questions referred to it as liquid nitrogen out of force of habit, but he meant solid. I have seen solids which were referred to as nitrogen, looking like dry ice (solid CO2). Wikipedia sez: Liquid nitrogen can easily be converted to the solid by placing it in a vacuum chamber pumped by a rotary vacuum pump. Liquid nitrogen freezes at 63 K (-210 °C; -346 °F). - Jed
RE: [Vo]:Tel Aviv Superconductor- Levitation
I was only guessing. Jeff Driscoll found the answer in these videos http://www.youtube.com/watch?v=VyOtIsnG71U http://www.youtube.com/watch?v=VyOtIsnG71Ufeature=related feature=related http://www.youtube.com/watch?v=6lmtbLu5nxw http://www.youtube.com/watch?v=6lmtbLu5nxwfeature=related feature=related It looks like they took a thin sapphire disk of the sputtered Y123, added a disk of solid nitrogen on top and wrapped it in a clear film – which then fogs up to make it appear to be cloth. Very clever … but the real science is in the crystal alignment and doping of the thin films. Jones From: Jed Rothwell I thought it was solid nitrogen. I thought the person asking questions referred to it as liquid nitrogen out of force of habit, but he meant solid. I have seen solids which were referred to as nitrogen, looking like dry ice (solid CO2). Wikipedia sez: Liquid nitrogen can easily be converted to the solid by placing it in a vacuum chamber pumped by a rotary vacuum pump. Liquid nitrogen freezes at 63 K (−210 °C; −346 °F). - Jed
Re: [Vo]:Tel Aviv Superconductor- Levitation
I have done experiments with flux pinning and 123 superconductor myself. Pick the green projector on page 3 to view. http://www.angelfire.com/scifi2/zpt/chapter4.html#Pg3 The rf coils release the flux pinning seen below. The 123 material goes through its transition temp withing seconds from being removed from the nitrogen bath. enjoy Frank Z
Re: [Vo]:Tel Aviv Superconductor- Levitation
The amazing thing about flux pinning and flux release is what is learned from a superconductor can be applied to the atomic spectrum and to cold fusion. http://www.sciencedirect.com/science/article/pii/S1875389211006092 Frank Z -Original Message- From: fznidarsic fznidar...@aol.com To: vortex-l vortex-l@eskimo.com Sent: Tue, Oct 18, 2011 8:04 am Subject: Re: [Vo]:Tel Aviv Superconductor- Levitation I have done experiments with flux pinning and 123 superconductor myself. Pick the green projector on page 3 to view. http://www.angelfire.com/scifi2/zpt/chapter4.html#Pg3 The rf coils release the flux pinning seen below. The 123 material goes through its transition temp withing seconds from being removed from the nitrogen bath. enjoy Frank Z
