Wednesday 30 September 2015

Mushroom may power your future cellphones

Researchers have created a new type of lithium-ion battery anode using portabella mushrooms, which are inexpensive, environmentally friendly and easy to produce.Nanocarbon architectures derived from biological materials such as mushrooms can be considered a green and sustainable alternative to graphite-based anodes, said Cengiz Ozkan, professor of mechanical engineering and materials science and engineering at University of California, Riverside, US.The current industry standard for rechargeable lithium-ion battery anodes is synthetic graphite, which comes with a high cost of manufacturing because it requires tedious purification and preparation processes that are also harmful to the environment.Using biomass, a biological material from living or recently living organisms, as a replacement for graphite, has drawn recent attention because of its high carbon content, low cost and environmental friendliness.The researchers were drawn to using mushrooms as a form of biomass because past research has established they are highly porous, meaning they have a lot of small spaces for liquid or air to pass through."With battery materials like this, future cell phones may see an increase in run time after many uses, rather than a decrease, due to apparent activation of blind pores within the carbon architectures as the cell charges and discharges over time," Brennan Campbell from University of California, Riverside explained.That porosity is important for batteries because it creates more space for the storage and transfer of energy, a critical component to improving battery performance.In addition, the high potassium salt concentration in mushrooms allows for increased electrolyte-active material over time by activating more pores, gradually increasing its capacity.A conventional anode allows lithium to fully access most of the material during the first few cycles and capacity fades from electrode damage occurs from that point on.The mushroom carbon anode technology could, with optimisation, replace graphite anodes, the researchers said.The study was published in the journal Scientific Reports.


Liquid water exists on Mars, boosting hopes for life there, NASA says....


Potentially life-giving water still flows across the ancient surface of Mars from time to time, NASA scientists said Monday in revealing a potential breakthrough in both the search for life beyond Earth and human hopes to one day travel there.While the discovery doesn't by itself offer evidence of life on Mars, either past or present, it does boost hopes that the harsh landscape still offers some refuge for microbes to cling to existence.
"The existence of liquid water, even if it is super salty briny water, gives the possibility that if there's life on Mars, that we have a way to describe how it might survive," said John Grunsfeld, associate administrator for the Science Mission Directorate at NASA.NASA researchers using an imager aboard the Mars Reconnaissance Orbiter confirmed the watery flows by looking at light waves returned from seasonal dark streaks on the surface, long suspected to be associated with liquid water.
The investigation showed the streaks absorb light at specific wavelengths associated with chemicals known to pull water from the Martian atmosphere in a process known as deliquescence, said Georgia Tech doctoral student Lujendra Ojha, who first discovered the streaks while still an undergraduate student at the University of Arizona in 2011.The chemicals allow the water to remain liquid at lower temperatures but also help keep it from boiling off in the thin atmosphere of Mars, the researchers said.


Researchers have known for many years that Mars has water frozen at its poles, in its thin atmosphere, and, most recently, in tiny puddles that appear to form at night on the surface.
96 photos: Mars rover Curiosity
Nor is it the first potential clue that Mars could have once -- or may still -- host life. The Mars Curiosity rover, for instance, has detected methane on the surface of Mars, as well as other chemical signatures suggesting the possibility of past or present life.It remains to be seen whether the new discovery improves the odds of life on Mars, but researcher Mary Beth Wilhelm said the results suggest "more habitable conditions on the near surface of Mars than previously thought."
How habitable, she said, depends on how salty and how cold the conditions are.
But Alfred McEwen, who heads up NASA's HiRISE high-resolution camera aboard the Mars orbiter, said he's fairly confident life will one day be found on Mars.


NASA: Proof of alien life closer 01:08"It's very likely, I think, that there's life somewhere in the crust of Mars, microbes," he said.Jim Green, director of planetary science at NASA, said the discovery announced Monday puts NASA in a perfect position to look for that life.

"We haven't been able to answer the question, 'Does life exist beyond Earth?' " Green said. "But following the water is a critical element of that. We now have, I think, a great opportunity to be in the right locations on Mars to thoroughly investigate that."