PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • An ion engine functions by taking a gas such as xenon, and ionizing it (removing electrons from the atoms) to make it responsive to electric and magnetic fields.
http://www.w3.org/ns/prov#wasQuotedFrom
  • nasa.gov