Sunlight Controls Fate of Permafrost’s Released Carbon
Just how much Arctic permafrost will thaw in the future and how fast heat-trapping carbon dioxide will be released from those warming soils is a topic of lively debate among climate scientists.
To answer those questions, scientists need to understand the mechanisms that control the conversion of organic soil carbon into carbon dioxide gas. Until now, researchers believed that bacteria were largely responsible.
A new study from Lund Univ. has, for the first time, reconstructed solar activity during the last ice age. The study shows that the regional climate is influenced by the sun and offers opportunities to better predict future climate conditions in certain regions.
For the first time, a research team has been able to reconstruct the solar activity at the end of the last ice age, around 20,000–10,000 years ago, by analyzing trace elements in ice cores in Greenland and cave formations from China. During the last glacial maximum, Sweden was covered in a thick ice sheet that stretched all the way down to northern Germany and sea levels were more than 100 meters lower than they are today, because the water was frozen in the extensive ice caps. The new study shows that the sun’s variation influences the climate in a similar way regardless of whether the climate is extreme, as during the Ice Age, or as it is today.
Workers at a state-of-the-art solar plant in the Mojave Desert have a name for birds that fly through the plant’s concentrated sun rays — “streamers,” for the smoke plume that comes from birds that ignite in midair.
Federal wildlife investigators who visited the BrightSource Energy plant last year and watched as birds burned and fell, reporting an average of one “streamer” every two minutes, are urging California officials to halt the operator’s application to build a still-bigger version.
Printable robots — those that can be assembled from parts produced by 3-D printers — have long been a topic of research in the lab of Daniela Rus, a professor of electrical engineering and computer science at MIT.
At this year’s IEEE International Conference on Robotics and Automation, Rus’ group and its collaborators introduce a new wrinkle on the idea: bakable robots. In two new papers, the researchers demonstrate the promise of printable robotic components that, when heated, automatically fold into prescribed three-dimensional configurations.
Vast amounts of excess heat are generated by industrial processes and by electric power plants; researchers around the world have spent decades seeking ways to harness some of this wasted energy. Most such efforts have focused on thermoelectric devices, solid-state materials that can produce electricity from a temperature gradient, but the efficiency of such devices is limited by the availability of materials.
Now, researchers at MIT and Stanford Univ. have found a new alternative for low-temperature waste-heat conversion into electricity — that is, in cases where temperature differences are less than 100 C.
The devastating wildfires scorching Southern California offer a glimpse of a warmer and fierier future, according to scientists and federal and international reports.
In the past three months, at least three different studies and reports have warned that wildfires are getting bigger, that man-made climate change is to blame, and it’s only going to get worse with more fires starting earlier in the year. While scientists are reluctant to blame global warming for any specific fire, they have been warning for years about how it will lead to more fires and earlier fire seasons.
Lightweight Materials Can Be Produced in Harsh Environments
The earth’s crust works like a pressure cooker. Minerals typically do not form under standard conditions, but at high temperatures and pressures. However, an environment of extreme heat and pressure has been considered to be absolutely unsuitable for organic molecules. Scientists at Vienna Univ. of Technology found out that under such seemingly hostile conditions, organic materials with remarkable material properties can be synthesized – for instance Kevlar, an extremely versatile high-performance material.
Materials that can be used for thermoelectric devices — those that turn a temperature difference into an electric voltage — have been known for decades. But until now there has been no good explanation for why just a few materials work well for these applications, while most others do not. Now, researchers at MIT and elsewhere say they have finally found a theoretical explanation for the differences, which could lead to the discovery of new, improved thermoelectric materials.
The findings — by MIT graduate student Sangyeop Lee and Gang Chen, the Carl Richard Soderberg Professor of Power Engineering; and four others — are reported this week in the journal Nature Communications.
Pasteurizing Raw Eggs Kills Salmonella, Doesn’t Harm Eggs
Classic Caesar salad, old-fashioned eggnog, some homemade ice cream — and many other popular foods — may contain raw eggs. Now, U.S. Department of Agriculture (USDA)-led research has produced a faster way to pasteurize raw, in-shell eggs without ruining their taste, texture, color or other important qualities.
The pasteurization procedure targets Salmonella. That’s because an estimated one out of every 20,000 chicken eggs produced in the U.S. has a high risk of being contaminated with Salmonella, notably S. enteritidis. That pathogen has been associated with eating raw or undercooked eggs, and can cause diarrhea, stomach cramps, fever and — in some instances — death.
Titanium alloy golf clubs can cause dangerous wildfires, UC Irvine scientists say. When a club coated with the lightweight metal is swung and strikes a rock, it creates sparks that can heat to more than 3,000 F for long enough to ignite dry foliage, according to findings published recently in the peer-reviewed journal Fire and Materials.
Orange County, Calif., fire investigators asked UC Irvine to determine whether such clubs could have caused blazes at Shady Canyon Golf Course in Irvine and Arroyo Trabuco Golf Club in Mission Viejo a few years ago.
Federal forecasters predict a warming of the central Pacific Ocean this year that will change weather worldwide. And that’s good news for a weather-weary U.S.
The warming, called an El Nino, is expected to lead to fewer Atlantic hurricanes and more rain next winter for drought-stricken California and southern states, and even a milder winter for the nation’s frigid northern tier next year, meteorologists say.
Nanoscale Pillars May Aid Conversion of Heat to Electricity
Univ. of Colorado Boulder scientists have found a creative way to radically improve thermoelectric materials, a finding that could one day lead to the development of improved solar panels, more energy-efficient cooling equipment and even the creation of new devices that could turn the vast amounts of heat wasted at power plants into more electricity.
The technique — building an array of tiny pillars on top of a sheet of thermoelectric material — represents an entirely new way of attacking a century-old problem, says Mahmoud Hussein, an assistant professor of aerospace engineering sciences who pioneered the discovery.
An international group of astrophysicists has found evidence strongly supporting a solution to a long-standing puzzle about the birth of some of the most massive stars in the universe. Young massive stars, which have more than 10 times the mass of the Sun, shine brightly in the ultraviolet, heating the gas around them, and it has long been a mystery why the hot gas doesn’t explode outwards. Now, observations made by a team of researchers using the Jansky Very Large Array (VLA), a radio astronomy observatory in New Mexico, have confirmed predications that as the gas cloud collapses, it forms dense filamentary structures that absorb the star’s ultraviolet radiation when it passes through them. As a result, the surrounding heated nebula flickers like a candle.
Researchers are proposing a new technology that might control the flow of heat the way electronic devices control electrical current, an advance that could have applications in a diverse range of fields from electronics to textiles.
The concept uses tiny triangular structures to control “phonons,” quantum-mechanical phenomena that describe how vibrations travel through a material’s crystal structure.