Farmed fish overtake beef - bad news for the environment

http://www.newscientist.com/article/dn23719-farmed-fish-overtakes-farmed-beef-for-first-time.html

For the first time in modern history, the world has been producing more farmed fish than farmed beef. But instead of being a boon for the environment, many fish farms are damaging it because of the types of fish they breed.

A report by the Earth Policy Institute in Washington DC has found that farmed fish production is rising rapidly, reaching a record 66 million tonnes in 2012. Cattle farm output, by contrast, has levelled off, with just 63 million tonnes of beef produced in the same year.

If current trends continue, humans are set to consume more farmed fish than wild-caught fish by 2015, 

Some farmed fish are good for the environment. Chinese aquaculture, which accounts for 62 per cent of the world's farmed fish, relies heavily on species such as silver carp. These can be grown on rice paddies and feed on grass, plankton and detritus. This relatively sustainable way of farming fish boosts rice yields and produces little pollution.

However, other popular farmed species such as salmon are carnivorous. They must be fed on smaller fish like anchovies, caught from the wild. As a result, salmon can only be farmed by further depleting wild fish stocks. "It would be preferable to shift the balance back in favour of farmed fish raised without feeds based on protein from other animals,"

Holographic video could enable 2D displays with higher resolution and less power consumption

http://www.sciencedaily.com/releases/2013/06/130619132450.htm

Media Labis building a prototype color holographic-video display whose resolution is roughly that of a standard-definition TV and which can update video images 30 times a second, fast enough to produce the illusion of motion. The heart of the display is an optical chip, resembling a microscope slide, that Smalley built, using only MIT facilities, for about $10.

"Until now, if you wanted to make a light modulator for a video projector, or an LCD panel for a TV, or something like that, you had to deal with the red light, the green light and the blue light separately," he says. "If you look closely at an LCD panel, each pixel actually has three little color filters in it. There's a red subpixel, a green subpixel and a blue subpixel."

"First of all," he continues, "that's inefficient, because the filters, even if they were perfect, would throw away two-thirds of the light. But second, it reduces either the resolution or the speed at which the modulator can operate."

According to Smalley, on the other hand, "What's most exciting about [the new chip] is that it's a waveguide-based platform, which is a major departure from every other type of spatial light modulator used for holographic video right now."

The Rise of the three wheeled electric scooters..?

http://www.sciencedaily.com/releases/2013/06/130617092441.htm

"Although electric scooters offer many advantages, a lot of motorists either cannot or do not want to make the switch for trips into town. They simply lack the experience of traveling on two wheels," Thanks to the additional wheel on the rear axle combined with a special chassis, the electric vehicle manages to be both stable and nimble.

Environmentally friendly battery made from wood:

http://www.sciencedaily.com/releases/2013/06/130619122205.htm

scientists have developed a battery made from a sliver of wood coated with tin that shows promise for becoming a tiny, long-lasting, efficient and environmentally friendly energy source which is 1,000  times thinner than a sheet of paper!

Lead author Hongli Zhu and other team members describe lab experiments in which the device performed successfully though 400 charge-discharge cycles, putting it among the longest-lasting of all sodium-ion nanobatteries. Batteries using the new technology would be best suited for large-scale energy storage applications, such as wind farms or solar energy installations, the report indicates.

http://www.sciencedaily.com/releases/2013/06/130619195221.htm

Using sodium instead of lithium, as many rechargeable batteries do, makes the battery environmentally benign. Sodium doesn't store energy as efficiently as lithium, so you won't see this battery in your cell phone -- instead, its low cost and common materials would make it ideal to store huge amounts of energy at once, such as solar energy at a power plant.

"Pushing sodium ions through tin anodes often weaken the tin's connection to its base material," said Li, an associate professor of mechanical engineering. "But the wood fibers are soft enough to serve as a mechanical buffer, and thus can accommodate tin's changes. This is the key to our long-lasting sodium-ion batteries."