nocturnal emission reflex emission of semen during sleep. thermionic emission the application of heat, such as to a filament, resulting in the emission of electrons and ions. thermionic emission
Which means if the equipment if design to has a high factor of safety, the cost to fabricate the equipment will increase and same to the weight too. But if the equipment is design with low cost and low weight, the factor of safety will be low too.
Limiting factor. A limiting factor of a system, is an input or variable such that a small change in it from the present value would cause a non-negligible change in an output or other measure of the system.