In this work classes of symmetries for partial differential equations which can be written in a conserved form are found. These nonclassical potential symmetries are realized as nonclassical symmetries of the associated potential system and are neither cl

The multilayer Mead–Markus plate consists of m+1m+1 Kirchhoff plate layers bound together by mm shear-deformable layers. We consider the case in which the Poisson ratios are the same in each Kirchhoff plate layer and linear viscous shear damping is included in the shear deformable layers. We show, via a contradiction argument, that the associated semigroup is analytic.