About: http://webisa.webdatacommons.org/310677116

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	When an alternating voltage is placed on the piezo-electric plates, they expand and contract in such manner as to drive the narrow ends of the elliptical shell.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es