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Making monster waves
Posted by wideant in General Physics on March 2, 2010
Rogue waves — giant waves that spring up suddenly and tower over the seas around them—have inspired physicists to look for an analogue in light. These high-intensity pulses can cross large distances without losing information. Now a team of physicists have identified one set of conditions that produces optical rogue waves. Their findings are reported in Physical Review A and highlighted with in the October 19 issue of Physics.
Rogue waves were thought to be a sailor’s tall tale until an 85-foot wave broke over an oil platform in the North Sea in 1995. Since then, scientists have tried to understand how such outsized waves arise from the erratic interactions of smaller waves on a choppy sea, with an eye toward creating them on purpose in the form of light traveling in an optical fiber. Read the rest of this entry »
Sharing Scarce Flu Vaccine May Be Best: Game Theory Model Shows Hoarding Supplies Isn’t Healthiest Choice
As manufacturers race to test and deliver an H1N1 influenza vaccine by October, public health officials are working equally feverishly to determine how scarce doses should be allocated.
Because supplies are expected to be short, governments may be tempted to buy large quantities of vaccine and antiviral treatments to protect their citizens. Yet research from Duke University’s Fuqua school of Business and the European School of Management and Technology (ESMT) indicates that in the case of some epidemics, countries would be best served by giving their drug supplies to another country.
Duke Professor Peng Sun, Duke PhD student Liu Yang, and Professor Francis deVericourt of ESMT created a model based on game theory to test how countries with adequate drug supplies should react to an epidemic affecting a neighboring country with little or no supply of vaccine or treatments. Read the rest of this entry »
Growing geodesic carbon nanodomes
Posted by wideant in Nanophysics on March 1, 2010
Researchers analyzing the assembly of graphene (sheets of carbon only one atom thick) on a surface of iridium have found that the sheets grow by first forming tiny carbon domes. The discovery offers new insight into the growth of graphene layers and points the way to possible methods for assembling components of graphene-based computer circuits.
Paolo Lacovig, Monica Pozzo, Dario Alf?, Paolo Vilmercati, Alessandro Baraldi, and Silvano Lizzit at institutions in Italy, the UK and USA report their discovery in a paper appearing October 12 in the journal Physical Review Letters.
The researchers’ spectroscopic study suggests that graphene grows in the form of tiny islands built of concentric rings of carbon atoms. The islands are strongly bonded to the iridium surface at their perimeters, but are not bonded to the iridium at their centers, which causes them to bulge upward in the middle to form minuscule geodesic domes. Read the rest of this entry »