About: http://webisa.webdatacommons.org/216368510

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	The grating consists of a solid or semisolid material 40 and is preferably a transparent material, such as plastic, and with one surface containing a periodic structure of closely spaced grooves 42 of spacing d as shown in FIG. 4a.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com