PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • Some of the principles of methane or biogas production oxygen) releases a mixture of gases (biogas) which usually consists of 50- 60% methane, 40-50% carbon dioxide, and about 1% by volume of hydrogen sulfide, ammonia and other trace gases.
http://www.w3.org/ns/prov#wasQuotedFrom
  • osti.gov