ScienceNews: Colliding dust grains charge each other up

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bystander
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ScienceNews: Colliding dust grains charge each other up

Post by bystander » Mon Apr 12, 2010 3:48 pm

Colliding dust grains charge each other up
Science News: Matter & Energy: 2010 April 11
Particles in a cloud can electrify themselves

It’s the ultimate love-at-first-sight story: In the middle of the desert, hundreds of miles from anything else, lonely sand grains meet up in a crowd and decide to electrify each other. Sparks fly.
Image
Ash particles generated lightning storms when Mount Rinjani erupted in Indonesia in 1995.
(Oliver Spalt/Wikimedia Commons)


Swirling dust shocks physicists
Nature News: Physics: 2010 April 11
Swarms of self-charging particles defy gravity — and expectations.

Scientists have explained how lightning can occur even in the driest deserts. A new theory describes how neutral dust can gain an electrical life of its own.
Image
Sparks fly in dust storms. (J. Reed/Science Faction/Corbis)

Why do Particle Clouds Generate Electric Charges?
Grains in desert sandstorms spontaneously generate strong electrical charges; likewise volcanic dust plumes produce spectacular lightning displays. Charged particle clouds also cause devastating explosions in food, drug, and coal processing industries. Despite the wide-ranging importance of granular charging in both nature and industry, even the simplest aspects of its causes remain elusive, for it is difficult to understand how inert grains in contact with little more than other inert grains can generate the large charges observed. In this paper, we present a simple yet predictive explanation for the charging of granular materials in collisional flows. We argue from very basic considerations that charge transfer can be expected in collisions of identical dielectric grains, and we confirm the model's predictions using discrete element simulations and a tabletop granular experiment.

livemind
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Joined: Thu Apr 15, 2010 6:42 pm
AKA: Sputnick

Re: ScienceNews: Colliding dust grains charge each other up

Post by livemind » Thu Apr 15, 2010 7:03 pm

As first explained by Sputnick when explaining the deep dust on Phobos, that dust soon to be Russia's mine of rare earths.