Posts Tagged ‘electricity’

Low-current electrical pulses delivered to a specific brain area during learning improved recollection of distinct memories, according to a study published online in eLife.

Researchers at the University of California, Los Angeles (UCLA) believe electrical stimulation offers hope for the treatment of memory disorders, such as Alzheimer’s disease.

The study involved 13 patients with epilepsy who had ultrafine wires implanted in their brains to pinpoint the origin of seizures. During a person-recognition task, researchers monitored the wires to record neuronal activity as memories were formed, and then sent a specific pattern of quick pulses to the entorhinal area of the brain, an area critical to learning and memory.
In 8 of 9 patients who received electrical pulses to the right side of the entorhinal area, the ability to recognize specific faces and disregard similar-looking ones improved significantly. However, the 4 patients who received electrical stimulation on the left side of the brain area showed no improvement in recall.

By using the ultrafine wires, researchers were able to precisely target the stimulation while using a voltage that was one-tenth to one-fifth of the strength used in previous studies.

“These results suggest that microstimulation with physiologic level currents—a radical departure from commonly used deep brain stimulation protocols—is sufficient to modulate human behavior,” researchers wrote.

The findings also point to the importance of stimulating the right entorhinal region to promote improved memory recollection.

—Jolynn Tumolo

References

Titiz AS, Hill MRH, Mankin EA, et al. Theta-burst microstimulation in the human entorhinal area improves memory specificity. eLife. 2017 October 24.

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Scientists have successfully developed a method of producing electricity from seawater, with help from the Sun. Instead of harvesting hydrogen, the new photoelectrochemical cell produces hydrogen peroxide for electricity.

Researchers at Osaka University found a way to turn seawater—one of the most abundant resources on Earth—into hydrogen peroxide (H2O2) using sunlight, which can then be used to generate electricity in fuel cells. This adds to the ever growing number of existing alternative energy options as the world continues to move towards green energy.

“Utilization of solar energy as a primary energy source has been strongly demanded to reduce emissions of harmful and/or greenhouse gases produced by burning fossil fuels. However, large fluctuation of solar energy depending on the length of the daytime is a serious problem. To utilize solar energy in the night time, solar energy should be stored in the form of chemical energy and used as a fuel to produce electricity,” the researchers wrote in their paper.

Previous technologies focused on splitting the molecules of pure water to harvest hydrogen.

As previously mentioned, the new research, instead of harvesting hydrogen from pure water, turns seawater into hydrogen peroxide. Gaseous hydrogen production from pure water has a lower solar energy conversion and is much harder to store, whereas the team notes, “H2O2 can be produced as an aqueous solution from water and O2 in the air.”

It is also much easier and safer to store and transport in higher densities, compared to highly compressed hydrogen gas.

There are other methods of producing H2O2, but they are impractical in that the processes themselves require a lot of energy, essentially defeating the purpose. This is the first time someone developed a photocatalytic method efficient enough to make H2O2 use in fuel cells viable.

The process involves a new photoelectrochemical cell developed to produce H2O2 when sunlight illuminates the photocatalyst, which then absorbs photons and initiates chemical reactions with the energy, resulting in H2O2.

A test conducted for 24 hours shows that the H2O2 concentration in seawater reached about 48mM (millimolar), compared to 2mM in pure water. Researchers found that this was made possible by seawater’s negatively charged chlorine enhancing the photocatalysis.

That said, this method isn’t yet as good as other solar power processes, but it’s a start. Researchers aim to improve efficiency with better materials and lower costs.

“In the future, we plan to work on developing a method for the low-cost, large-scale production of H2O2 from seawater,” Fukuzumi said. “This may replace the current high-cost production of H2O2 from H2 (from mainly natural gas) and O2.”

http://futurism.com/theres-a-new-way-to-generate-power-using-seawater/

A by-product of Beaufort cheese, skimmed whey, is converted into biogas, a mixture of methane and carbon dioxide, at the plant in Albertville, in Savoie in the French Alps.

Bacteria are added to the whey to produce the gas, which is then used to generate electricity that is sold to the energy company EDF.

“Whey is our fuel,” said François Decker of Valbio, the company that designed and built the power station, which opened in October. “It’s quite simply the same as the ingredient in natural yoghurt.”

After full-fat milk is used to make Beaufort cheese, whey and cream are left over. The cream is taken to make ricotta cheese, butter and protein powder, which is used as a food supplement.

The residual skimmed whey is then placed in a tank with bacteria, where natural fermentation produces methane in the same way that the gas is produced in cows’ stomachs.

The gas is then fed through an engine that heats water to 90 degrees C and generates electricity. The plant will produce about 2.8 million kilowatt-hours (kWh) per year, enough electricity to supply a community of 1,500 people, Mr Decker told Le Parisien newspaper.

It is not the first cheese-based power station, but one of the largest. Valbio built its first prototype plant 10 years ago beside an abbey where monks have made cheese since the 12th century.

Since then, about 20 other small-scale plants have been built in France, other European countries and Canada. More units are planned in Australia, Italy, Brazil and Uruguay.

In Somerset, the family-owned cheesemakers, Wyke Farms, generate their own electricity from waste cheese, cow manure and leftover crops. The mixture is poured into biodigester vessels that generate enough electricity to make the cheese producer self-sufficient.

http://www.telegraph.co.uk/news/worldnews/europe/france/12060538/French-power-station-generates-electricity-from-cheese.html

By Traci Watson, National Geographic

Don’t blame the lure of a glowing smartphone for keeping you up too late. Even people without modern technology don’t sleep the night away, new research says.

Members of three hunter-gatherer societies who lack electricity—and thus evenings filled with Facebook, Candy Crush, and 200 TV channels—get an average of only 6.4 hours of shut-eye a night, scientists have found. That’s no more than many humans who lead a harried industrial lifestyle, and less than the seven to nine hours recommended for most adults by the National Sleep Foundation.

People from these groups—two in Africa, one in South America—tend to nod off long after sundown and wake before dawn, contrary to the romantic vision of life without electric lights and electronic gadgets, the researchers report in Thursday’s Current Biology.

“Seeing the same pattern in three groups separated by thousands of miles on two continents (makes) it pretty clear that this is the natural pattern,” says study leader and sleep researcher Jerome Siegel of the University of California, Los Angeles. “Maybe people should be a little bit more relaxed about sleeping. If you sleep seven hours a night, that’s close to what our ancestors were sleeping.”

Previous research has linked lack of sleep to ills ranging from poor judgment to obesity to heart disease. The rise of mesmerizing electronic devices small enough to carry into bed has only heightened worries about a modern-day epidemic of bad sleep. One recent study found that after bedtime sessions with an eBook reader, test subjects took longer to fall asleep and were groggier in the morning than when they’d curled up with an old-fashioned paper book.

Many scientists argue that artificial lighting curtailed our rest, leading to sleep deficits. But Siegel questioned that storyline. He was studying the sleep of wild lions when he got the inspiration to monitor the sleep of pre-industrial people, whose habits might provide insight into the slumber of early humans.

Siegel and his colleagues recruited members of Bolivia’s Tsimane, who hunt and grow crops in the Amazonian basin, and hunter-gatherers from the Hadza society of Tanzania and the San people in Namibia. These are among the few remaining societies without electricity, artificial lighting, and climate control. At night, they build small fires and retire to simple houses built of materials such as grass and branches.

The researchers asked members of each group to wear wristwatch-like devices that record light levels and the smallest twitch and jerk. Many Tsimane thought the request comical, but almost all wanted to participate, says study co-author Gandhi Yetish of the University of New Mexico. People in the study fell asleep an average of just under three and a half hours after sunset, sleep records showed, and mostly awakened an average of an hour before sunrise.

The notable slugabeds are the San, who in the summer get up an hour after sunrise. The researchers noticed that at both the San and Tsimane research sites, summer nights during the study period lasted 11 hours, but mornings were chillier in the San village. That fits with other data showing the three groups tend to nod off when the night grows cold and rouse when temperature bottoms out before dawn.

Our time to wake and our time to sleep, Siegel says, seem to be dictated in part by natural temperature and light levels—and modern humans are divorced from both. He suggests some insomniacs might benefit from re-creating our ancient exposure to warmth and cold.

http://news.nationalgeographic.com/2015/10/20151015-paleo-sleep-time-hadza-san-tsimane-science/

The plant, called the Omniprocessor, was designed and built by Janicki Bioenergy and backed by the Bill & Melinda Gates Foundation. The facility would try to prevent diseases caused by contaminated water supplies.

A test plant is up and working at Janicki’s headquarters north of Seattle, according to a blog post by Gates. The first operational plant is planned for Senegal.

“The next-generation processor, more advanced than the one I saw, will handle waste from 100,000 people, producing up to 86,000 liters of potable water a day and a net 250 kw of electricity,” he wrote. “If we get it right, it will be a good example of how philanthropy can provide seed money that draws bright people to work on big problems, eventually creating a self-supporting industry.”

Included is a video of him drinking a glass of the water produced by the plant, which he describes as “delicious” and “as good as any I’ve had out of the bottle.”

“Having studied the engineering behind it, I would happily drink it every day. It’s that safe,” he writes on the post.

The feces is heated to 1000 degrees Celsius, or 1,832 degrees Fahrenheit to draw off the water, which is then further treated to make sure it is safe. But the dried out feces can then be burned, producing enough heat to generate electricity needed to extract the water. Excess electricity can be sold to outside users, as can the water.

Gates says diseases caused by poor sanitation kill some 700,000 children every year. The Bill & Melinda Gates Foundation is making an effort to improve sanitation in the developing world.

“Today, in many places without modern sewage systems, truckers take the waste from latrines and dump it into the nearest river or the ocean—or at a treatment facility that doesn’t actually treat the sewage,” he wrote. “Either way, it often ends up in the water supply.”

http://money.cnn.com/2015/01/07/technology/innovationnation/gates-poop-water/index.html

A new superthin material can cool buildings without requiring electricity, by beaming heat directly into outer space, researchers say.

In addition to cooling areas that don’t have access to electrical power, the material could help reduce demand for electricity, since air conditioning accounts for nearly 15 percent of the electricity consumed by buildings in the United States.

The heart of the new cooler is a multilayered material measuring just 1.8 microns thick, which is thinner than the thinnest sheet of aluminum foil. In comparison, the average human hair is about 100 microns wide.

This material is made of seven layers of silicon dioxide and hafnium dioxide on top of a thin layer of silver. The way each layer varies in thickness makes the material bend visible and invisible forms of light in ways that grant it cooling properties.

Invisible light in the form of infrared radiation is one key way all objects shed heat. “If you use an infrared camera, you can see we all glow in infrared light,” said study co-author Shanhui Fan, an electrical engineer at Stanford University in California.

One way this material helps keep things cool is by serving as a highly effective mirror. By reflecting 97 percent of sunlight away, it helps keep anything it covers from heating up.

In addition, when this material does absorb heat, its composition and structure ensure that it only emits very specific wavelengths of infrared radiation, ones that air does not absorb, the researchers said. Instead, this infrared radiation is free to leave the atmosphere and head out into space.

“The coldness of the universe is a vast resource that we can benefit from,” Fan told Live Science.

The scientists tested a prototype of their cooler on a clear winter day in Stanford, California, and found it could cool to nearly 9 degrees Fahrenheit (5 degrees Celsius) cooler than the surrounding air, even in the sunlight.

“This is very novel and an extraordinarily simple idea,” Eli Yablonovitch, a photonics crystal expert at the University of California, Berkeley, who did not take part in this research, said in a statement.

The researchers suggested that their material’s cost and performance compare favorably to those of other rooftop air-conditioning systems, such as those driven by electricity derived from solar cells. The new device could also work alongside these other technologies, the researchers said.

However, the scientists cautioned that their prototype measures only about 8 inches (20 centimeters) across, or about the size of a personal pizza. “We are now scaling production up to make larger samples,” Fan said. “To cool buildings, you really need to cover large areas.”

The scientists detailed their findings in the Nov. 26 journal Nature.

http://www.livescience.com/48942-cooling-buildings-without-electricity.html