About: http://webisa.webdatacommons.org/225376207

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 improvement of claim 1 wherein said concave surface is an outer surface of a piezoelectric transducer.
http://www.w3.org/ns/prov#wasQuotedFrom	google.fr