noun, Biology. 1. an orientation of an organism to an external stimulus, as light, especially by growth rather than by movement. Origin of tropism. 1895-1900. First recorded in 1895-1900; independent use of -tropism. Related forms. tropismatic.
Friction on as-grown graphene (Fig. 1c) is ultra-low and rather uniform with its magnitude close to the previous reports4. In contrast, friction on graphene after ï¬uorination becomes
Researchers have found yet another use for the wonder material graphene. A composite material made from reduced graphene oxide and magnetite could effectively remove arsenic from drinking water, according to new work done in South Korea. Graphene is a sheet of carbon just one atom thick that also exists as an oxide. Reduced graphene oxide (RGO) is a chemical state of the material that has gained electrons. The purification process works by dispersing a magnetite-RGO composite in water, where it soaks up arsenic. The composite is then quickly and efficiently removed from the water using a permanent magnet.