A process of comminution of corn stover having a grain direction to produce a mixture of corn stover, by feeding the corn stover in a direction of travel substantially randomly to the grain direction one or more times through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of corn stover travel. Other apparatus and a method of manufacturing a tag device are also provided. The invention further relates to polymer mixtures which are suitable for producing films which are resistant to tear propagation. The Ru or RuO2 film is exposed at the bottom of the contact hole.