<http://webisa.webdatacommons.org/283072076>	<http://www.w3.org/ns/prov#value>	"Thus, nitrogen is used instead of a gas, such as compressed air, that contains higher levels of impurities." .
<http://webisa.webdatacommons.org/283072076>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/prov/281379519>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/283072076> .
<http://webisa.webdatacommons.org/283072076>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<freshpatents.com> .