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Domain: photonics.com
Stories and comments across the archive that link to photonics.com.
Stories · 5
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Fiber Optic Spanner (Wrench) Developed
xclr8r writes "A technique to use fiber optics to adjust microscopic particles has been developed. 'Rather than an actual physical device that wraps around a cell or other microscopic particle to apply rotational force, the spanner (the British term for a wrench) is created when two laser beams — emitted by a pair of optical fibers — strike opposite sides of the microscopic object, trapping and holding it in place. By slightly offsetting the fibers, the beams can impart a small twisting force, causing the object to rotate in place. It is possible to create rotation along any axis and in any direction, depending on the positioning of the fibers.' Applications of this technology can be used in a number of ways, including cancer research. This technology could be used to actually manipulate DNA. Associate Professor of Physics Samarendra Mohanty states that macroscale applications are a possibility, including 'direct conversion of solar energy to mechanical energy,' or possibly using it to 'simulate an environment in which photons radiated from the sun could propel the reflective motors in solar sails, a promising future technology for deep-space travel.'" -
"Tabletop" Fusion Researcher Committed Scientific Misconduct
Geoffrey.landis writes "A Purdue University panel investigated allegations against nuclear engineering professor Rusi Taleyarkhan, finding that he had in fact committed scientific misconduct in his work. Taleyarkhan had published papers in which he reported seeing evidence of nuclear fusion in the collapse of tiny bubbles in a liquid subjected to ultrasonic excitation — a finding that would be groundbreaking, if true, but one that apparently could not be replicated by other researchers. The allegations against Taleyarkhan were made in March of 2006. A local Indiana paper gives the full list of allegations against Taleyarkhan, and the resolution of each by the panel. The full report (PDF) is also available. Of the nine specific allegations, only two were found to comprise scientific misconduct. The committee 'could not find any other instances of scientists being able to replicate Taleyarkhan's results without Taleyarkhan having direct involvement with the experiments,' but notes that this comes 'just short of questioning whether Taleyarkhan's results were fraudulent.'" We've discussed this gentleman's work and the scrutiny it has received several times, and members of the scientific community seem to have given him the benefit of the doubt in many cases. -
Bubble Fusion Inquiry Under Wraps
hubie writes "Purdue University launched an investigation last March into the questionable research behavior and actions by Prof. Rusi Taleyarkhan following his controversial claims of achieving bubble fusion. The investigation has completed but the results are being kept secret. The alleged behavior is remeniscent of another tabletop fusion incident from a number of years back. Coincidentally, Purdue University has just secured Federal money to open up a new energy center. A more cynical person than I might suggest that there is a connection between the two." -
First Silicon Laser
An anonymous reader writes "Since the creation of the first working laser, scientists have fashioned them from substances ranging from neon to sapphire. Silicon was not considered a candidate, because its structure wouldn't allow for the proper line-up of electrons needed to get this semiconductor to emit light. That has now changed thanks to three researchers at Brown University who have created the first directly pumped silicon laser by drilling billions of holes in a small bit of silicon using a nanoscale template." -
Yet Another Method Of Achieving Nuclear Fusion
deglr6328 writes "Recent research has seen the use of the pyroelectric effect, the compression of bubbles using ultrasound and gas jet irradiation for producing nuclear fusion on small tabletop-scales. Yet another method can now be added to the list which uses ultraintense laser irradiation striking a borated plastic target to heat a plasma to billion kelvin temperatures and achieves aneutronic (clean) proton-boron fusion. (The PRL paper can be read online.) Though, like the other recently discovered exotic methods of attaining fusion, it does not look like a method which can be scaled up to ignition or even anywhere near break even, it still may have important use in the laboratory for the examination of such incredibly high temperature plasmas."