Tag Archives: sunlight

Volcanic Aerosols, not Pollutants, Tamped down Recent Earth Warming, Says CU Study

A team led by the University of Colorado Boulder looking for clues about why Earth did not warm as much as scientists expected between 2000 and 2010 now thinks the culprits are hiding in plain sight — dozens of volcanoes spewing sulfur dioxide.

The study results essentially exonerate Asia, including India and China, two countries that are estimated to have increased their industrial sulfur dioxide emissions by about 60 percent from 2000 to 2010 through coal burning, said lead study author Ryan Neely, who led the research as part of his CU-Boulder doctoral thesis. Small amounts of sulfur dioxide emissions from Earth’s surface eventually rise 12 to 20 miles into the stratospheric aerosol layer of the atmosphere, where chemical reactions create sulfuric acid and water particles that reflect sunlight back to space, cooling the planet. (more…)

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A Dual Look at Photosystem II Using the World’s Most Powerful X-Ray Laser

Berkeley Lab and SLAC Researchers Demonstrate Room Temperature Simultaneous Diffraction/Spectroscopy of Metalloenzymes

From providing living cells with energy, to nitrogen fixation, to the splitting of water molecules, the catalytic activities of metalloenzymes – proteins that contain a metal ion – are vital to life on Earth. A better understanding of the chemistry behind these catalytic activities could pave the way for exciting new technologies, most prominently artificial photosynthesis systems that would provide  clean, green and renewable energy. Now, researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the SLAC National Accelerator Laboratory have taken a major step towards achieving this goal.

Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the world’s most powerful X-ray laser, the researchers were able to simultaneously image at room temperature the atomic and electronic structures of photosystem II, a metalloenzyme critical to photosynthesis. (more…)

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Fungi, Fungi Everywhere

New research shows fungi living beneath the seafloor are widespread

Fungi living beneath the seafloor are widespread in ocean environments around the world, according to a new paper by scientists at the University of Delaware and Woods Hole Oceanographic Institution. 

“They’re ubiquitous,” said co-author Jennifer Biddle, assistant professor of marine biosciences at UD’s College of Earth, Ocean, and Environment. “They are everywhere.” (more…)

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New Path to More Efficient Organic Solar Cells Uncovered at Berkeley Lab’s Advanced Light Source

Why are efficient and affordable solar cells so highly coveted? Volume. The amount of solar energy lighting up Earth’s land mass every year is nearly 3,000 times the total amount of annual human energy use. But to compete with energy from fossil fuels, photovoltaic devices must convert sunlight to electricity with a certain measure of efficiency. For polymer-based organic photovoltaic cells, which are far less expensive to manufacture than silicon-based solar cells, scientists have long believed that the key to high efficiencies rests in the purity of the polymer/organic cell’s two domains – acceptor and donor. Now, however, an alternate and possibly easier route forward has been shown.

Working at Berkeley Lab’s Advanced Light Source (ALS), a premier source of X-ray and ultraviolet light beams for research, an international team of scientists found that for highly efficient polymer/organic photovoltaic cells, size matters. (more…)

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Plants Unpack Winter Coats When Days Get Shorter

EAST LANSING, Mich. — Mechanisms that protect plants from freezing are placed in storage during the summer and wisely unpacked when days get shorter.

In the current issue of the Proceedings of the National Academy of Sciences, Michael Thomashow, University Distinguished Professor of molecular genetics, demonstrates how the CBF (C-repeat binding factor) cold response pathway is inactive during warmer months when days are long, and how it’s triggered by waning sunlight to prepare plants for freezing temperatures. (more…)

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Experiment Would Test Cloud Geoengineering as Way to Slow Warming

Even though it sounds like science fiction, researchers are taking a second look at a controversial idea that uses futuristic ships to shoot salt water high into the sky over the oceans, creating clouds that reflect sunlight and thus counter global warming.

University of Washington atmospheric physicist Rob Wood describes a possible way to run an experiment to test the concept on a small scale in a comprehensive paper published this month in the journal Philosophical Transactions of the Royal Society.

The point of the paper — which includes updates on the latest study into what kind of ship would be best to spray the salt water into the sky, how large the water droplets should be and the potential climatological impacts — is to encourage more scientists to consider the idea of marine cloud brightening and even poke holes in it. In the paper, he and a colleague detail an experiment to test the concept. (more…)

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It’s in the Genes: Research Pinpoints How Plants Know When to Flower

Scientists believe they’ve pinpointed the last crucial piece of the 80-year-old puzzle of how plants “know” when to flower.

Determining the proper time to flower, important if a plant is to reproduce successfully, involves a sequence of molecular events, a plant’s circadian clock and sunlight.

Understanding how flowering works in the simple plant used in this study – Arabidopsis – should lead to a better understanding of how the same genes work in more complex plants grown as crops such as rice, wheat and barley, according to Takato Imaizumi, a University of Washington assistant professor of biology and corresponding author of a paper in the May 25 issue of the journal Science. (more…)

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UCLA Engineers Create Tandem Polymer Solar Cells That Set Record For Energy-Conversion

In the effort to convert sunlight into electricity, photovoltaic solar cells that use conductive organic polymers for light absorption and conversion have shown great potential. Organic polymers can be produced in high volumes at low cost, resulting in photovoltaic devices that are cheap, lightweight and flexible.

In the last few years, much work has been done to improve the efficiency with which these devices convert sunlight into power, including the development of new materials, device structures and processing techniques. (more…)

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