SLAC, Stanford gadget grabs more solar energy to disinfect water faster
August 15, 2016 11:39 AM - DOE/SLAC National Accelerator Laboratory via EurekAlert!
In many parts of the world, the only way to make germy water safe is by boiling, which consumes precious fuel, or by putting it out in the sun in a plastic bottle so ultraviolet rays will kill the microbes. But because UV rays carry only 4 percent of the sun's total energy, the UV method takes six to 48 hours, limiting the amount of water people can disinfect this way.
Now researchers at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University have created a nanostructured device, about half the size of a postage stamp, that disinfects water much faster than the UV method by also making use of the visible part of the solar spectrum, which contains 50 percent of the sun's energy.
The Colony-Killing Mistake Backyard Beekeepers Are Making
August 12, 2016 03:31 PM - Dan Gunderson via National Public Radio
Jonathan Garaas has learned a few things in three seasons of backyard beekeeping: Bees are fascinating. They're complicated. And keeping them alive is not easy.
Every two weeks, the Fargo attorney opens the hives to check the bees and search for varroa mites, pests that suck the bees' blood and can transmit disease. If he sees too many of the pinhead-sized parasites, he applies a chemical treatment.
NASA's Fermi mission expands its search for dark matter
August 12, 2016 03:19 PM - Nasa/Goddard Space Flight Center via EurekAlert!
Dark matter, the mysterious substance that constitutes most of the material universe, remains as elusive as ever. Although experiments on the ground and in space have yet to find a trace of dark matter, the results are helping scientists rule out some of the many theoretical possibilities. Three studies published earlier this year, using six or more years of data from NASA's Fermi Gamma-ray Space Telescope, have broadened the mission's dark matter hunt using some novel approaches.
NASA measures winds of Tropical Storm Conson
August 11, 2016 04:43 PM - NASA/Goddard Space Flight Center via EurekAlert!
NASA's RapidScat instrument provided measurements of sustained wind speeds as Tropical Storm Conson continued tracking north through the northwestern Pacific Ocean.
When RapidScat passed over Conson on Aug. 10, it was near peak intensity. RapidScat measured maximum sustained winds around the center of circulation as fast as 49 mph (22 meters per second/79 kph) on Aug. 10. The RapidScat instrument that flies aboard the International Space Station measures Earth's ocean surface wind speed and direction over open waters.
Discovery of sunlight-driven organic chemistry on water surfaces
August 11, 2016 03:41 PM - American Association for The Advancement of Science via EurekAlert!
Fatty acids found on the surface of water droplets react with sunlight to form organic molecules, a new study reports, essentially uncovering a previously unknown form of photolysis.
The results could affect models that account for aerosol particles, including models related to climate. Conventional wisdom holds that carboxylic acids and saturated fatty acids, which are abundant throughout the environment, only react with hydroxyl radicals and are not affected by sunlight.
Self-shading windows switch from clear to opaque
August 11, 2016 01:30 PM - Massachusetts Institute of Technology via EurekAlert!
A team of researchers at MIT has developed a new way of making windows that can switch from transparent to opaque, potentially saving energy by blocking sunlight on hot days and thus reducing air-conditioning costs. While other systems for causing glass to darken do exist, the new method offers significant advantages by combining rapid response times and low power needs.
Once the glass is switched from clear to dark, or vice versa, the new system requires little to no power to maintain its new state; unlike other materials, it only needs electricity when it's time to switch back again.
California Freeways to Go Greener by Generating Electricity
August 10, 2016 10:32 AM - Laura Goldman, Care2
Energy conservation is probably not the first thing that comes to mind when you think about freeways jammed with idling vehicles.
But in California, which has some of the most congested freeways in the country, that’s about to change. The California Energy Commission (CEC) has approved a pilot program in which piezoelectric crystals will be installed on several freeways.
Making a solar energy conversion breakthrough with help from a ferroelectrics pioneer
August 8, 2016 01:32 PM - Drexel University via EurekAlert!
Designers of solar cells may soon be setting their sights higher, as a discovery by a team of researchers has revealed a class of materials that could be better at converting sunlight into energy than those currently being used in solar arrays. Their research shows how a material can be used to extract power from a small portion of the sunlight spectrum with a conversion efficiency that is above its theoretical maximum -- a value called the Shockley-Queisser limit. This finding, which could lead to more power-efficient solar cells, was seeded in a near-half-century old discovery by Russian physicist Vladimir M. Fridkin, a visiting professor of physics at Drexel, who is also known as one of the innovators behind the photocopier.
NASA Satellite Reveals How Much Saharan Dust Feeds Amazon's Plants
August 5, 2016 04:40 PM - Goddard Space Flight Center
What connects Earth's largest, hottest desert to its largest tropical rain forest?
The Sahara Desert is a near-uninterrupted brown band of sand and scrub across the northern third of Africa. The Amazon rain forest is a dense green mass of humid jungle that covers northeast South America. But after strong winds sweep across the Sahara, a tan cloud rises in the air, stretches between the continents, and ties together the desert and the jungle. It’s dust. And lots of it.
For the first time, a NASA satellite has quantified in three dimensions how much dust makes this trans-Atlantic journey. Scientists have not only measured the volume of dust, they have also calculated how much phosphorus – remnant in Saharan sands from part of the desert’s past as a lake bed – gets carried across the ocean from one of the planet’s most desolate places to one of its most fertile.
Hot 'new' material found to exist in nature
August 5, 2016 04:23 PM - McGill University via EurekAlert!
One of the hottest new materials is a class of porous solids known as metal-organic frameworks, or MOFs. These man-made materials were introduced in the 1990s, and researchers around the world are working on ways to use them as molecular sponges for applications such as hydrogen storage, carbon sequestration, or photovoltaics.
Now, a surprising discovery by scientists in Canada and Russia reveals that MOFs also exist in nature -- albeit in the form of rare minerals found so far only in Siberian coal mines.
The finding, published in the journal Science Advances, "completely changes the normal view of these highly popular materials as solely artificial, 'designer' solids," says senior author Tomislav Friščić, an associate professor of chemistry at McGill University in Montreal. "This raises the possibility that there might be other, more abundant, MOF minerals out there."