About: http://webisa.webdatacommons.org/72589600

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	They contain a gas such as nitrogen and carbon dioxide sealed therein, so that they have a low dielectric constant, low loss tangent, and low specific gravity.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com