Lab Talk: Graphene goes ballistic, Marine reserves to the rescue
Two researchers discuss recent papers that excited their interest.
Graphene goes ballistic
Imagine if you could generate clean hydro-electricity in the Snowy Mountains and pass that electricity, without any loss, to Perth. It is impossible with today’s copper cables – electrical resistance makes long-distance transmission inefficient.
Graphene looks much more promising. This paper shows that graphene sheets can achieve “ballistic” conduction at room temperature. The electrons fly across the sheets with no scattering resistance.
Ballistic conduction is a step below superconductivity for effort-free electron flow – but superconductors require temperatures at least as low as -135°C to operate.
As the graphene sheets are only 40 nanometres long, they are as yet too small to be much use in an electricity grid. But researchers have focused on a much nearer-term, nanoscale application – more efficient transistors for consumer electronics.
Paper: Exceptional ballistic transport in epitaxial graphene nanoribbons.
Nature 2014, vol 506, p349–354
Marine reserves a buffer to climate change
Marine reserves are spectacular places to dive. In many places, they are the only place you are likely to bump into sharks, large groupers and other big fish, which grow large there because they can’t be fished. But a great amount of controversy surrounds the creation of marine protected areas, as fishers fight to keep access open.
This paper shows protection from fishing doesn’t only protect the large species directly vulnerable to being caught. The researchers studied the waters off Tasmania, a global warming hotspot, and found that in areas protected from fishing, the entire marine community was healthier and more resilient to change. Reserves suffered less colonisation by subtropical species moving from warmer waters.
This study shows that marine reserves are a conservation tool that can greatly enhance the health of our oceans.
Paper: Resilience and signatures of tropicalization in protected reef fish communities
Nature Climate Change, vol 4, p62-67