A 0.2m3 tank containing helium at 15 bar and 22 oC will be used to supply 4.5 moles per minute of helium at atmospheric pressure using a controlled adiabatic throttling valve. (1) If the tank is well insulated, what will be the pressure in the tank and the temperature of the gas stream leaving the throttling valve at any later time t? (2) If the tank is isothermal, what will be the pressure in the tank and the pressure in the tank as a function of time? Assuming helium to be an ideal gas with a constant heat capacity of 22J/(mol K), and that there is no heat transfer between the tank and the gas.

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