The compression ratio of a certain diesel engine is 15 to 1. this means that in the compression stroke the air in the cylinder is compressed to 1/15 of its initial volume. if the initial pressure is 10^5 pa and the initial temperature is 300 k, find the final pressure and temperature after compression. air is mostly a mixture of diatomic oxygen and nitrogen, so treat it as an ideal gas with (gamma)=1.4 . take the process to be adiabatic and reversible.

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