variable exponent spaces Asymptotic analysis 2 Asymptotic behaviors 2 Characteristic functions 2 Functionals 2 Mosco convergence 2 Mosco-convergence 2 Power-law 2 Sand 2 Sand-pile models 2 Variable exponents 2 elliptic equations 2 finite element method 2 power-law functionals 2 sandpile models 2