About: http://webisa.webdatacommons.org/30179806

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	Variables such as temperature, humidity and perhaps other factors seem to come into play, so that the optimum concentration one day might not quite be the optimum concentration on some other day.
http://www.w3.org/ns/prov#wasQuotedFrom	2spi.com