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Gizmorama - December 9, 2015
Good Morning,
Who knew that "green technology" isn't always so eco-friendly? Well, microwaves might help to change that. I know I'm being vague, but read the first story and it'll all make sense. Trust me.
Learn about this and more interesting stories from the scientific community in today's issue.
Until Next Time,
Erin
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*-- Water-clearning photocatalysts work better after being microwaved --*
WOLLONGONG, Australia - Photocatalysts are materials that absorb sunlight and speed up chemical reactions. Some are used to cleanup wastewater. But though they're considered a "green technology," they're not always so eco-friendly.
The process of synthesizing materials like titanium dioxide (TiO2) and bismuth vanadate (BiVO4) -- used to clean water, break down dyes and kill bacteria -- is energy intensive. But a new production process promises to make these materials more efficient and environmentally friendly.
Instead of high temperatures and intense pressure, researchers in Thailand and Australia have found a way cook up BiVO4 using microwaves.
"These materials have a wide range of applications, but there has been little done to improve the way we make them," Jun Chen, a materials scientist at the University of Wollongong, in Australia, said in a press release. "People say photocatalysts are green, but sometimes the way we generate these materials is not really energy efficient."
The new production process happens at temperatures between 60 and 90 degrees Celsius, and takes only 16 minutes. Current methods take six hours.
The new microwave technology also offers scientists greater control over the formation of BiVO4 nanoparticles. Each particle is formed more uniformly. Controlling the precise shape and size of these nanoparticles allows scientists to build a material more efficient at encouraging the kind of chemical reactions necessary for cleaning water.
In tests, the newly produced BiVO4 was just as effective at breaking down a dye called Rhodamine B.
"We were so surprised that not many people are focusing on this area -- only a few studies have been done using microwaves," said Chen. "We hope this work will be of considerable interest to materials scientists who want to employ green technology to simplify the synthesis process for inorganic crystal materials."
The newly discovered microwave technology was detailed this week in the journal Materials Today.
*-- Scientists uncover first detailed record of fast radio burst --*
PITTSBURGH - For the first time, astronomers have found a detailed record of the perplexing phenomenon known as a fast radio burst.
Scientists have been trying without much success to reveal the birthplace of these mysterious blasts of radio waves. New details, published this week in the journal Nature, offer the first clues as the origins of FRBs.
"We now know that the energy from this FRB passed through a dense, magnetized region shortly after it formed. This significantly narrows down the source's environment and type of event that triggered the burst," study author Kiyoshi Masui, an astronomer at the University of British Columbia and the Canadian Institute for Advanced Research, said in a press release.
Scientists believe thousands of FRBs race through the sky every day. But they last only a fraction of a second, making them incredibly difficult events to capture in detail.
Researchers discovered the new FRB record by using specially designed software to scan archival observations collected by the National Science Foundation's Green Bank Telescope.
The frequencies of radio waves become smeared during their trip through space, making them hard to detect among the mess of data captured by observatories. The effect is called a dispersion delay. The software used by in this new study worked by countering the dispersion delay.
When their analysis located a potential signal, the international team of astronomers soon realized they'd captured more FRB information than they ever had before.
"Hidden within an incredibly massive dataset, we found a very peculiar signal, one that matched all the known characteristics of a Fast Radio Burst, but with a tantalizing extra polarization element that we simply have never seen before," researcher Jeffrey Peterson, a cosmologist with Carnegie Mellon University, explained in a press release.
Polarization indicates the orientation of a wave or waves. The new polarization information allowed scientists to estimate the bursts origin. Because the waves' polarization suggested a corkscrew-like twisting, known as Faraday rotation, researchers were able to tell the FRB passed through a strong magnetic field not long after its genesis.
"This tells us something about the magnetic field that the burst traveled through on its way to us, giving a hint about the burst's environment," Masui explained. "It also gives the theorists a bit more to work with when they come up with explanations for these bursts."
Further analysis of its dispersion delay ruled out an origin source within the Milky Way. The analysis also showed the burst traveled through regions of ionized gas early in its journey, suggesting a birth near or in a faraway region of dense plasma.
Taken together, the findings point to a stellar genesis. Masui and his colleagues believe the FRB may have been generated by a starquake, an earthquake-like destabilization of the surface of a young magnetar, a strongly magnetized neutron star.
But their new paper offers details on just a single event. It's possible other FRBs could be caused by a range of other phenomena. To build a more definitive theory on the genesis of these bursts, more of them are going to have to be captured in the act.
"It's only statistics of one object at present," the researchers write. "This needs to be borne out by further discoveries."
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