Sci/tech

Butterflies use differences in leaf shape to distinguish between plants
July 28, 2016 04:46 PM - Frontiers in Ecology and Evolution via EurekAlert!

The preference of Heliconius butterflies for certain leaf shapes is innate, but can be reversed through learning. These results support a decades-old theory for explaining the evolution of the exceptional diversity of leaf shapes in passionflowers.

The tropical butterfly Heliconius eratodistinguishes between shapes, and uses them as a cue for choosing the plants on which to feed and lay eggs, shows new research by scientists from the University of Cambridge and the Smithsonian Tropical Research Institute. The butterfly has an innate preference for passionflowers with particular leaf shapes, but can learn to overcome this preference in favor of other shapes, especially those that are the most abundant in the local flora. These preferences can promote the evolution of plant biodiversity.

First whale detected by newly deployed acoustic buoy in New York Bight
July 28, 2016 04:15 PM - Wildlife Conservation Society via EurekAlert!

A new acoustic buoy recently deployed by scientists from the Woods Hole Oceanographic Institution (WHOI) and WCS's (Wildlife Conservation Society) New York Aquarium to listen for some of the world's biggest animals in the New York Bight has detected its first whale species, and it's a really big one.

Fixed in position some 22 miles south of Fire Island and fitted with a digital acoustic monitoring instrument, the hi-tech buoy is now operational and has detected the vocalizations of fin whales, enormous marine mammals second in size only to the blue whale, the largest animal species on earth. The first whale detection was made on Monday, July 4th, only 12 days after the buoy was placed in its current position on June 23rd.

Since that time, the buoy has made several fin whale detections; the most recent vocalizations were detected yesterday (July 27th) and today.

Videos reveal birds, bats and bugs near Ivanpah solar project power towers
July 27, 2016 04:15 PM - Us Geological Survey via EurekAlert!

Video surveillance is the most effective method for detecting animals flying around solar power towers, according to a study of various techniques by the U.S. Geological Survey and its partners at the Ivanpah Solar Electric Generating System facility in southeastern California.

This study is the first to examine a variety of remote sensing and sampling techniques to determine which technology might be most effective for monitoring how solar power facilities impact flying animals. The information will be used to further study the effects of solar power infrastructure on flying animals -- a subject about which little is known -- and to develop ways to lessen harmful effects.

At Ivanpah, evidence of flying animals impacted by intense heat near the solar towers had been observed. The new study showed that although birds and bats were occasionally seen near the towers at Ivanpah, most observations involved insects.

Silicon-air battery achieves running time of over 1,000 hours for the first time
July 26, 2016 03:48 PM - Forschungszentrum Juelich via ScienceDaily

Silicon-air batteries are viewed as a promising and cost-effective alternative to current energy storage technology. However, they have thus far only achieved relatively short running times. Jülich researchers have now discovered why.

In theory, silicon-air batteries have a much higher energy density and are also smaller and lighter than current lithium-ion batteries. They are also environmentally friendly and insensitive to external influences. Their most important advantage, however, is their material. Silicon is the second most abundant element in the Earth's crust after oxygen: it is cheap and its reserves are practically inexhaustible.

Biological wizardry ferments carbon monoxide into biofuel
July 26, 2016 02:27 PM - Cornell University via EurekAlert!

Cornell University biological engineers have deciphered the cellular strategy to make the biofuel ethanol, using an anaerobic microbe feeding on carbon monoxide - a common industrial waste gas.

"Instead of having the waste go to waste, you make it into something you want," said Ludmilla Aristilde, assistant professor in biological and environmental engineering. "In order to make the microbes do our work, we had to figure out how they work, their metabolism."

Aristilde collaborated with her colleague Lars Angenent, professor of biological and environmental engineering, on the project. She explained, "The Angenent group had taken a waste product and turned it into a useful product."

To make biofuel from inorganic, gaseous industrial rubbish, the researchers learned that the bacterium Clostridium ljungdahlii responds thermodynamically - rather than genetically - in the process of tuning favorable enzymatic reactions.

Lonely atoms, happily reunited
July 26, 2016 11:28 AM - Vienna University of Technology via EurekAlert!

At first glance, magnetite appears to be a rather inconspicuous grey mineral. But on an atomic scale, it has remarkable properties: on magnetite, single metal atoms are held in place, or they can be made to move across the surface. Sometimes several metal atoms on magnetite form small clusters. Such phenomena can dramatically change the chemical activity of the material. Atomic processes on the magnetite surface determine how well certain metal atoms can serve as catalysts for chemical reactions.

Scientists at TU Wien (Vienna), together with colleagues from Utrecht University, can now watch single platinum atoms form tiny clusters. Carbon monoxide plays a dual role in this process: It allows single platinum atoms to move and form pairs, and then it holds these pairs together for a long time. Only by increasing the temperature can the pair-bonds between platinum atoms can be broken.

Researchers printed energy producing photographs
July 26, 2016 10:52 AM - Aalto University via EurekAlert!

Solar cells have been manufactured already for a long from inexpensive materials with different printing techniques. Especially organic solar cells and dye-sensitized solar cells are suitable for printing.

-We wanted to take the idea of printed solar cells even further, and see if their materials could be inkjet-printed as pictures and text like traditional printing inks, tells University Lecturer Janne Halme.

When light is absorbed in an ordinary ink, it generates heat. A photovoltaic ink, however, coverts part of that energy to electricity. The darker the color, the more electricity is produced, because the human eye is most sensitive to that part of the solar radiation spectrum which has highest energy density. The most efficient solar cell is therefore pitch-black.

Solar Impulse Just Completed Its Momentous Flight Around the World
July 26, 2016 10:28 AM - Aarian Marshall via Wired.com

Solar Impulse 2 touched down in Abu Dhabi today, becoming the first fuel-free plane to successfully circumnavigate the globe. OK, so the 22,000-mile trip took a minute: The solar-powered bird lifted off from the same city in March 2015. But despite a few setbacks, the plane and Swiss pilot Bertrand Piccard (who took shifts with fellow flyer André Borschberg) touched down without incident.

Solar Impulse 2 is a seriously nifty machine. Its 236-foot wingspan makes it wider than a Boeing 747, but the thing is just 5,000 pounds. 17,000 rigid, photovoltaic panels charge four uber-efficient batteries, which make up nearly a third of the weight. Its four 17.4-horsepower motors definitely aren’t the fastest: The plane tops out around 90 mph, and traveled at an average of 38 mph across the Pacific. (Yeah, we’d honk at it on the highway, too.)

Spiders spin unique phononic material
July 25, 2016 01:50 PM - Rice University via EurekAlert!

New discoveries about spider silk could inspire novel materials to manipulate sound and heat in the same way semiconducting circuits manipulate electrons, according to scientists at Rice University, in Europe and in Singapore.

A paper in Nature Materials today looks at the microscopic structure of spider silk and reveals unique characteristics in the way it transmits phonons, quasiparticles of sound.

The research shows for the first time that spider silk has a phonon band gap. That means it can block phonon waves in certain frequencies in the same way an electronic band gap - the basic property of semiconducting materials - allows some electrons to pass and stops others.

The researchers wrote that their observation is the first discovery of a "hypersonic phononic band gap in a biological material."

Spiders spin unique phononic material
July 25, 2016 01:50 PM - Rice University via EurekAlert!

New discoveries about spider silk could inspire novel materials to manipulate sound and heat in the same way semiconducting circuits manipulate electrons, according to scientists at Rice University, in Europe and in Singapore.

A paper in Nature Materials today looks at the microscopic structure of spider silk and reveals unique characteristics in the way it transmits phonons, quasiparticles of sound.

The research shows for the first time that spider silk has a phonon band gap. That means it can block phonon waves in certain frequencies in the same way an electronic band gap - the basic property of semiconducting materials - allows some electrons to pass and stops others.

The researchers wrote that their observation is the first discovery of a "hypersonic phononic band gap in a biological material."

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