There are more uses of air cooled heat exchangers, much like the upstream production, refineries and petro-chemical facilities. It can also be employed on situations with good temperature, high pressure, corrosive fluids and environments. Moreover, air coolers could be equipped and employed in oil and coal refineries; compressor stations for gas pipelines; subsurface gas storage facilities; plants producing polychlorvinyl, polyethylene, glass fiber, biplastic; caustic soda plants; by-product coke plants and ammonia transportation and handling plants. Plasma can often be called the fourth state of matter, after solid, liquid, and gas. It is also sometimes described as an ionized gas i.e. a gas when the degree of energy is really high how the electrons escape from the atoms. This leads to soups of charged particles that happen to be overall quasi-neutral.