About: http://webisa.webdatacommons.org/100150718

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	Gas removal presents the greatest challenge because NARA requires the filtering of gases such as sulfur dioxide, nitrogen dioxide, ozone and aldehydes to levels ranging from 1.0 to 12.5 parts per billion.
http://www.w3.org/ns/prov#wasQuotedFrom	science.gov