About: http://webisa.webdatacommons.org/219299457

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 selected position is preferably less than ??/4 from the end or approximately n??/2 from the end, where ?? is the wavelength of the carrier frequency in the tubing string, and n is a positive integer.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com