About: http://webisa.webdatacommons.org/16529614

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	Typical impurities are atmospheric gases, such as water, carbon dioxide, oxygen, argon and nitrogen, any of which may be objectionable at some concentration level to a user because of some detriment occurring in the use of the helium.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com