Pyridine is a heterocyclic organic compound that is obtained as a byproduct during the gasification of coal. Pyridine has a strong odor and has a chemical structure similar to benzene.

A gas cylinder or a tank is a pressure vessel for storage and regulation of gases at above atmospheric pressure.

An ultrasound device is a medical imaging device, which uses high-frequency waves to visualize the internal organs of the body such as blood vessels, kidney, liver, human foetus, heart, etc.