The impeller made out of cast material in many cases may be called rotor, also. It is cheaper to cast the radial impeller right in the support it is fitted on, which is put in motion by the gearbox from an electric motor, combustion engine or by steam driven turbine.
Earth remains the only known planet to host life, due to a unique combination of factors. However, continued monitoring of alien worlds might one day change that, by finding other planets that share these attributes or by discovering other ways that life has found to blossom in the universe.
6 people found this useful. 1  Layers of the Atmosphere Earth is the only planet in the solar system with an atmosphere that can sustain life. 2  Layers of the Earth's Atmosphere Layers of gases surrounding Earth make up the composition of the atmosphere and almost all layers directly affect climate change. 3  The Periodic Table of Elements Life is ...