About: http://webisa.webdatacommons.org/21556879

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	There have heretofore been established techniques for producing a flat porous membrane by using any one of various kinds of materials such as polyacrylonitrile, cellulose acetate, polyvinyl chloride, polysulfone, nylon and polyester.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com