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."
Global Economy Has Reduced Its Energy Intensity by One-Third Since 1990
July 25, 2016 01:41 PM -
The global economy is becoming less energy intensive, using fewer fossil fuels to power productivity and economic growth, according to new data from the U.S. Department of Energy. Global energy intensity — a measure of energy consumption per unit of gross domestic product (GDP) — has decreased nearly one-third since 1990, the agency said. The U.S., for example, burned 5,900 British thermal units per dollar of GDP in 2015, compared to 6,600 BTUs in 2010.
Unlocking the secret to cheaper solar power
July 25, 2016 01:23 PM - American Institute of Physics (AIP) via ScienceDaily
As climate change garners more attention around the world, scientists at the University of Virginia and Cornell University have made critical advances in understanding the physical properties of an emerging class of solar cells that have the potential to dramatically lower the cost of solar energy.
Solar cells remain a focal point of scientific investigation because the sun offers the most abundant source of energy on earth. The concern, however, with conventional solar cells made from silicon is their cost. Even with recent improvements, they still require a significant amount of electricity and industrial processing to be manufactured.
In 2009, energy researchers turned their attention to a class of materials called "metal halide perovskites," or MHPs. They are sprayed on like paint onto solid objects, says Joshua Choi, an assistant professor of chemical engineering at the University of Virginia. As the solution dries, the MHPs crystallize into a thin film that can be used to capture energy in a solar cell.
New lithium-oxygen battery greatly improves energy efficiency, longevity
July 25, 2016 12:31 PM - Massachusetts Institute of Technology via EurekAlert!
Lithium-air batteries are considered highly promising technologies for electric cars and portable electronic devices because of their potential for delivering a high energy output in proportion to their weight. But such batteries have some pretty serious drawbacks: They waste much of the injected energy as heat and degrade relatively quickly. They also require expensive extra components to pump oxygen gas in and out, in an open-cell configuration that is very different from conventional sealed batteries.
But a new variation of the battery chemistry, which could be used in a conventional, fully sealed battery, promises similar theoretical performance as lithium-air batteries, while overcoming all of these drawbacks.
The new battery concept, called a nanolithia cathode battery, is described in the journalNature Energy in a paper by Ju Li, the Battelle Energy Alliance Professor of Nuclear Science and Engineering at MIT; postdoc Zhi Zhu; and five others at MIT, Argonne National Laboratory, and Peking University in China.
Can cinnamon turn you into a better learner?
July 25, 2016 07:16 AM - VETERANS AFFAIRS RESEARCH COMMUNICATIONS via EurekAlert!
If Dr. Kalipada Pahan's research pans out, the standard advice for failing students might one day be: Study harder and eat your cinnamon!
Pahan a researcher at Rush University and the Jesse Brown Veterans Affairs Medical Center in Chicago, has found that cinnamon turns poor learners into good ones--among mice, that is. He hopes the same will hold true for people.
Bird ranges vary more than thought
July 24, 2016 01:32 PM - University of Massachusetts at Amherst via Science Daily
A new study of population trends among 46 ecologically diverse bird species in North America overturns a long-held assumption that the climate conditions occupied by a species do not change over time. Instead, birds that have increased in abundance over the last 30 years now occupy a wider range of climate conditions than they did 30 years ago, and declining species occupying a smaller range.
A new study of population trends among 46 ecologically diverse bird species in North America conducted by avian ecologist Joel Ralston and colleagues at the University of Massachusetts Amherst overturns a long-held assumption that the climate conditions occupied by a species do not change over time.
Soon solar will be the cheapest power everywhere
July 22, 2016 10:04 AM - Chris Goodall, The Ecologist
Solar is already the cheapest available power across large swathes of the tropics, writes Chris Goodall - its cost down 99.7% since the early 70s. Soon it will be the cheapest electricity everywhere, providing clean, secure, affordable energy for all.
Towards the end of last year, Shell CEO Ben van Beurden made a little-noticed remark. He said that solar would become the "dominant backbone" of the world's energy system.
He didn't give a date for his prediction, or indeed define what 'dominant' means, but he accepted that the sun will eventually provide the cheapest energy source across almost all of the world.
Why Americans waste so much food
July 22, 2016 06:51 AM - Martha Filipic, Ohio State University
Even though American consumers throw away about 80 billion pounds of food a year, only about half are aware that food waste is a problem. Even more, researchers have identified that most people perceive benefits to throwing food away, some of which have limited basis in fact.
A study published today in PLOS ONE is just the second peer-reviewed large-scale consumer survey about food waste and is the first in the U.S. to identify patterns regarding how Americans form attitudes on food waste.
Mars rover's laser can now target rocks all by itself
July 21, 2016 05:07 PM - DOE/LOS Alamos National Laboratory via EurekAlert!
New software is enabling ChemCam, the laser spectrometer on NASA's Curiosity Mars rover, to select rock targets autonomously -- the first time autonomous target selection is available for an instrument of this kind on any robotic planetary mission. Developed jointly at Los Alamos National Laboratory and the Research Institute in Astrophysics and Planetology in Toulouse, France, the ChemCam (chemistry and camera) instrument aboard Curiosity "zaps" rocks on Mars and analyzes their chemical make-up. While most ChemCam targets are still selected by scientists, the rover itself now chooses multiple targets per week.
"This new capability will give us a chance to analyze even more rock and soil samples on Mars," said Roger Wiens, principal investigator for ChemCam at Los Alamos. "The science team is not always available to pick samples for analysis. Having a smarter rover that can pick its own samples is completely in line with self-driving cars and other smart technologies being implemented on Earth."
Trees' surprising role in the boreal water cycle quantified
July 21, 2016 04:55 PM - University of Alaska Fairbanks via EurekAlert!
Approximately 25 to 50 percent of a living tree is made up of water, depending on the species and time of year. The water stored in trees has previously been considered just a minor part of the water cycle, but a new study by University of Alaska Fairbanks scientists shows otherwise.
Research published this week in Nature Scientific Reports is the first to show that the uptake of snowmelt water by deciduous trees represents a large and previously overlooked aspect of the water balance in boreal watersheds. The study was led by Jessica Young-Robertson, who worked with other scientists from the National Weather Service and UAF's International Arctic Research Center and Geophysical Institute.