[□=□]
[lemma=□]
Hybrid powertrains are exactly what the name implies : dual powertrains , one for internal combustion and one for electric power , that work together to use and regenerate energy while you drive . A variety of technologies are in place to reduce the amount of pollution being produced by the combustion of coal . However , concentrated amounts of fuel are necessary for efficient combustion ( burning ) which provides energy . A variable camshaft timing system for an internal combustion engine comprising a housing having an outer circumference for accepting drive force , a rotor for connection to a camshaft coaxially located within the housing capable of rotation to shift the relative angular position of the housing and the rotor , a locking pin , and a centrifugal valve . In combustion science , there are three basic types of flames , namely , a jet burner , a pre-mixed flame , and a diffuse flame .