Sonoluminescence

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Teonikije
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Придружен: 28 Мар 2009, 15:37

Sonoluminescence

Порука од Teonikije » 08 Јан 2010, 12:19



Sonoluminescence can occur when a sound wave of sufficient intensity induces a gaseous cavity within a liquid to collapse quickly. This cavity may take the form of a pre-existing bubble, or may be generated through a process known as cavitation. Sonoluminescence in the laboratory can be made to be stable, so that a single bubble will expand and collapse over and over again in a periodic fashion, emitting a burst of light each time it collapses. For this to occur, a standing acoustic wave is set up within a liquid, and the bubble will sit at a pressure anti-node of the standing wave. The frequencies of resonance depend on the shape and size of the container in which the bubble is contained.

Evo zanimljivog i kontroverznog dela price:

Nuclear reactions

Some have argued that the Rayleigh-Plesset equation described above is unreliable for predicting bubble temperatures and that actual temperatures in sonoluminescing systems can be far higher than 20,000 Kelvin. Some research claims to have measured temperatures as high as 100,000 Kelvin, and speculates temperatures can reach into the millions of Kelvin.[9] Temperatures this high could cause thermonuclear fusion. This possibility is sometimes referred to as bubble fusion.
On January 27, 2006, researchers at Rensselaer Polytechnic Institute claimed to have produced fusion in sonoluminescence experiments.[10][11] To date, these results have not been reproduced by other members of the scientific community.
Recent experiments (2002, 2005) of R. P. Taleyarkhan, et al., using deuterated acetone show measurements of tritium and neutron output consistent with fusion, but these measurements have not been reproduced outside of the Taleyarkhan lab and remain controversial. Brian Naranjo of the University of California, Los Angeles, has recently completed an analysis of the Taleyarkhan results, claiming that Taleyarkhan had most likely misinterpreted the radioactive decay of standard lab materials for the byproducts of nuclear fusion. In 2008, The Purdue University (where these experiments were performed) stripped R. P. Taleyarkhan of his professorship after accusing him of research misconduct, due to his controversial works on bubble fusion.

Evo dokumentarca kolega s BBC-ija bas o ovome:
A BBC Horizon documentary on a US government scientist’s claim that he had made nuclear fusion out of sound waves in his laboratory.
http://video.google.co.uk/videoplay?doc ... 947&hl=en#

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