Maastricht Economic and social Research and  training centre on Innovation and Technology

 
Levelling Latin America
Mining innovation can bring more sustainable and inclusive growth, especially across the Americas…
See: https://www.merit.unu.edu/mining-in-latin-america-using-innovation-to-level-the-playing-field/



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All headlines
  • A mystery source is producing banned ozone-destroying chemicals
  • Water filter inspired by Alan Turing passes first test
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  • In an interplanetary first, NASA to fly a helicopter on Mars
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  • 'Water cloak' uses electromagnetic waves to eliminate turbulence
    Fuel-efficient ships that produce no wakes could soon be a reality thanks to computer simulations of 'water cloaks' done by researchers from Duke University in the US.

    They team has shown that ions present in ocean water can be accelerated by electromagnetic waves in such a way that any turbulence created by sea-going vessels is cancelled out. Their work offers new opportunities for creating ships with greater propulsion efficiency - and could also be used to make vessels that are harder to detect.

    The researchers exploit magnetohydrodynamic forces, which involves the motion of charged particles in a conducting fluid when subjected to electromagnetic fields. The field induces an electric current in the fluid, polarising the charged particles. In turn, the polarised particles change the magnetic field, which generates a force on the fluid as a whole.

    Seawater contains an abundance of ions including sodium, potassium and magnesium, and can therefore be subjected to magnetohydrodynamic forces. In the new approach, electromagnetic fields would be used to accelerate water in the direction it would travel under normal turbulence conditions - essentially 'pushing it out of the way' of a moving ship.

    As the vessel passes through the accelerated fluid, any movements due to turbulent and shear forces are cancelled out. The water around the ship appears to remain completely still relative to the surrounding environment, thus eliminating the wake and acting as a functioning water cloak.

    Physics World / Physical Review E.    December 19, 2017