Nonlinear boundary conditions 100 Boundary conditions 24 p-Laplacian 18 Blow-up 14 Nonlinear equations 12 Blow up 10 Numerical approximations 10 Problem solving 10 Sobolev trace embedding 10 Variational problems 10 Asymptotic behaviour 8 Elliptic systems 8 Mathematical models 8 Boundary value problems 6 Eigenvalue problems 6 Eigenvalues and eigenfunctions 6 Elliptic equations 6 Heat equation 6 Numerical blow-up 6 Porous medium equation 6 Resonance 6 Sobolev trace constants 6 Theorem proving 6 Topological methods 6 nonlinear boundary conditions 6 Avalanche 4 Bessel functions 4 Critical exponents 4 Differential equations 4 Fast diffusion equation 4