About: http://webisa.webdatacommons.org/179337389

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 spheres are then applied to the surface of the back-electrode, by brushing or other means, to a density of 20 to 50 microspheres per square mm.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com