Room-temperature superconductivity?

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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DeltaV
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Re: Room-temperature superconductivity?

Postby DeltaV » Tue Apr 22, 2014 5:19 pm

Periodic steps in the resistance vs. temperature characteristics of doped graphite and graphene: evidence of superconductivity?
http://arxiv.org/abs/1307.0581

Betruger
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Re: Room-temperature superconductivity?

Postby Betruger » Mon May 12, 2014 11:57 pm

http://nextbigfuture.com/2014/05/one-of ... s-has.html
Researchers confirmed that charge density waves are a ubiquitous phenomenon in cuprates and that they strenuously oppose superconductivity, prevailing as the temperature rises.

By applying Sachdev’s algorithm to a new round of data, Davis and his group mapped out the structure of the charge density waves, showing that the d-wave distribution of electrons was, indeed, their source.

“The paper establishes that the two patterns are the same,” Sachdev said. “It just works beautifully.”


http://arxiv.org/abs/1404.0362 - Intra-unit-cell Nematic Density Wave: Unified Broken-Symmetry of the Cuprate Pseudogap State
The identity of the fundamental broken symmetry (if any) in the cuprate pseudogap state is unresolved. In fact, two apparently distinct forms of electronic symmetry breaking, one of intra-unit-cell rotational symmetry (Q=0 nematic) and the other of lattice translational symmetry (Q≠0 density wave), are reported extensively. However, indications of linkage between these two phenomena suggest the prospect of a unified fundamental description, with one intriguing possibility being an intra-unit-cell nematic density wave. Here we carry out site-specific measurements within each CuO2 unit-cell, segregating the results into three separate electronic structure images containing only the Cu sites (Cu(r)) and only the x/y-axis O sites (Ox(r) and Oy(r)). Phase resolved Fourier analysis reveals directly that the incommensurate modulations in the Ox(r) and Oy(r) sublattice images consistently exhibit a relative phase of π. We confirm this discovery on two highly distinct cuprate compounds, ruling out tunnel matrix-element and materials specific systematics. These observations demonstrate by direct sublattice phase-resolved visualization that the cuprate density wave consists essentially of spatial modulations of the intra-unit-cell nematicity; this state can equally well be described as an intra-unit-cell density wave with a d-symmetry form factor.

K. Fujita, M. H. Hamidian, S. D. Edkins, Chung Koo Kim, Y. Kohsaka, M. Azuma, M. Takano, H. Takagi, H. Eisaki, S. Uchida, A. Allais, M. J. Lawler, E. -A. Kim, Subir Sachdev, J. C. Séamus Davis
You can do anything you want with laws except make Americans obey them. | What I want to do is to look up S. . . . I call him the Schadenfreudean Man.

ohiovr
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Re: Room-temperature superconductivity?

Postby ohiovr » Thu May 15, 2014 2:16 pm

I didn't read all 124 pages so far (I'm on page 10) could this mean that a 0 ev work function surface has been discovered? If so I know of an immediate application...

EDIT
Never mind, a material with a 0 ev work function must already be a gas. Dumb idea again. Also ordinary superconductors do not necessarily have low work functions as conductivity and work function do not appear to be related. Otherwise platinum would be a very low work function material, yet it has the highest work function of any metal.

GIThruster
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Re: Room-temperature superconductivity?

Postby GIThruster » Fri May 16, 2014 6:40 pm

Correct. Work function has to do with the electron affinity of a material.

http://en.wikipedia.org/wiki/Electron_affinity

It's especially interesting in relation to the Schottkey Barrier in capacitors with high work function electrodes such as platinum.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

ohiovr
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Re: Room-temperature superconductivity?

Postby ohiovr » Fri May 16, 2014 7:01 pm

GIThruster wrote:Correct. Work function has to do with the electron affinity of a material.

http://en.wikipedia.org/wiki/Electron_affinity

It's especially interesting in relation to the Schottkey Barrier in capacitors with high work function electrodes such as platinum.


Thank you, this is good stuff

303
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Re: Room-temperature superconductivity?

Postby 303 » Mon Jun 30, 2014 4:47 pm

new world record

http://arxiv.org/abs/1406.0686 - A Trapped Field of 17.6 T in Melt-Processed, Bulk Gd-Ba-Cu-O Reinforced with Shrink-Fit Steel

Asterix
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Re: Room-temperature superconductivity?

Postby Asterix » Tue Jul 01, 2014 2:23 am

Astounding field strength, but 77K is hardly room temperature.

paperburn1
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Re: Room-temperature superconductivity?

Postby paperburn1 » Tue Jul 01, 2014 8:58 pm

Still needs to work at a few degrees warmer so that liquid nitrogen can be used on an industrial scale . Since it is boiling, most of the liquid nitrogen used in laboratories and in cryogenics shows is at a temperature of 77.2 K.
I am not a nuclear physicist, but play one on the internet.


DeltaV
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Re: Room-temperature superconductivity?

Postby DeltaV » Sun Nov 09, 2014 7:19 pm

http://www.ingentaconnect.com/search/article?option2=author&value2=Prins%2c+Johan+F&sortDescending=true&sortField=prism_publicationDate&pageSize=50&index=1
Directional emissions from a moving light-source: Coincidence and simultaneity
Prins, Johan F.
Physics Essays, Volume 27, Number 1, March 2014, pp. 38-54(17)
Abstract:
Directional emissions of light-pulses from a point-source (which is stationary at the origin of a moving inertial reference-frame) towards detectors which are all stationary at a constant radial-distance from the light-source (within the latter's inertial reference-frame) are transformed into another time-synchronized inertial reference-frame relative to which the source is moving with a speed v. Both the Galilean-transformation and the Lorentz-transformation are used. Light-pulses along different directions are compared to the equivalent situation when a spherical wavefront is emitted from the same source. The Galilean-transformation gives transformed coordinates of points on this wavefront that remain coincident on this wavefront; which, in turn, remains centered at the origin of the moving inertial reference-frame. In contrast, the Lorentz-transformation mandates that the same spherical wavefront must be observed as twin wavefronts, each of which remains centered at one of the origins of the moving and the stationary reference-frames, respectively. Here it is found that the Lorentz-transformation of simultaneous-instantaneous position-coordinates, of points on the wavefront within the moving inertial reference-frame, does not result in points which are simultaneously situated on its twin wavefront within the stationary inertial reference-frame. This is a compelling proof that an event which occurs at nonzero position-coordinates and at a nonzero time within the moving inertial reference-frame is not observed coincidently from the origin of another time-synchronized inertial reference-frame relative to which the reference-frame of the source is moving.

http://www.ingentaconnect.com/search/article?option2=author&value2=Prins%2c+Johan+F&sortDescending=true&sortField=prism_publicationDate&pageSize=50&index=2
The length of a longitudinally moving rod
Prins, Johan F.
Physics Essays, Volume 26, Number 4, December 2013, pp. 599-603(5)
Abstract:
Einstein used the Lorentz-equations to transform the instantaneous position-coordinates at the moving-tail and moving-nose of a rod (within an inertial reference-frame (IRF) relative to which the rod is moving with a speed v) into the inertial reference-frame within which the rod is permanently stationary. He concluded from this transformation that such a rod contracts when it is moving past at a speed v. But, according to Galileo's principle of inertia, the natural state of a matter-entity, when it experiences no forces, is to remain stationary within its own inertial reference-frame. Motion of such an entity with mass is caused by a relativistic coordinate transformation of its position-coordinates from the inertial reference-frame within which this entity is permanently stationary into the inertial reference-frame within which the entity is observed to be moving with the speed v. When judged in terms of Galileo's concept of inertia, Einstein's transformation of moving coordinates into permanently stationary coordinates has no physics-meaning. Here, the change in length of a rod (passing at speed v) is derived by Lorentz-transforming the permanently stationary position-coordinates at the beginning and end of the rod, from the inertial reference-frame within which the rod is permanently stationary into the inertial reference-frame relative to which the rod is moving with speed v. In contrast to Einstein's derivation, an increase in the length of the moving rod is obtained: It is found that this length-increase bestows on any matter-entity a de Broglie wavelength.

GIThruster
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Re: Room-temperature superconductivity?

Postby GIThruster » Tue Nov 11, 2014 12:19 am

Good for Johan to finally get published in a peer review journal other than materials science. Will be good to get feedback from this.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

DeltaV
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Re: Room-temperature superconductivity?

Postby DeltaV » Sun Jun 21, 2015 8:01 pm

Johan, if you are still around, this paper I found while browsing the EMdrive thread over at http://forum.nasaspaceflight.com/index.php?topic=37642.2060 might be of interest:

Photons inside a waveguide as massive particles
http://arxiv.org/abs/0708.3519
In the paper, we show that there exists a close analogy between the behavior of de Broglie matter waves and that of electromagnetic waves inside a hollow waveguide, such that the guided photons can be treated as free massive particles subject to a relativistic quantum-mechanical equation. Inspired by the effective rest mass of guided photons and the zitterbewegung phenomenon of the Dirac electron, at variance with the well-known Higgs mechanism we present some different heuristic ideas on the origin of mass.

DeltaV
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Re: Room-temperature superconductivity?

Postby DeltaV » Sun Dec 06, 2015 3:37 am

Researchers find new phase of carbon, make diamond at room temperature
http://phys.org/news/2015-11-phase-carbon-diamond-room-temperature.html

Giorgio
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Re: Room-temperature superconductivity?

Postby Giorgio » Sun Dec 06, 2015 5:37 am

DeltaV wrote:Researchers find new phase of carbon, make diamond at room temperature
http://phys.org/news/2015-11-phase-carbon-diamond-room-temperature.html


I placed a copy of the research paper on a file sharing service for everyone that wants to give a look at it.
Here. It will be available for 90 days.

Properly engineered this technology has the potential to be quite a game changer in almost all areas of actual human technology.
I am very keen to see how this will develop in the next years.
Look, stars!

DeltaV
Posts: 2245
Joined: Mon Oct 12, 2009 5:05 am

Re: Room-temperature superconductivity?

Postby DeltaV » Mon Dec 07, 2015 11:31 pm

Giorgio wrote:I placed a copy of the research paper on a file sharing service for everyone that wants to give a look at it.
Here. It will be available for 90 days.

Why? The PDF is open-access. Can you not get it in China?


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