About: http://webisa.webdatacommons.org/4972406

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	Actual pulse start and stop times depend upon changing variables, such as friction and impedance that make graphical presentation needlessly complex and, therefore, exact timing will not be attempted in these figures.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com