Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200°c and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6x10^-11 m2/s, andthe diffusion flux is found to be 1.2 x10^-7 kg/m^2.s. also, it is known that the concentration of nitrogen in the steel at the high pressure surface is 4 kg/m^3. how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m^3

i would think it's food chain

area of focus

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia