About: http://webisa.webdatacommons.org/118026194

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The cavity may be filled with a gas, for example, air or an inert gas such as nitrogen, argon or helium.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com