This volume is an account of the lectures delivered at the third Scheve￾ningen Conference on Differential Equations.
The conference was again organized by B.L.J. Braaksma (University of Gro￾ningen), I?. Eckhaus (University of Utrecht), E.M. de Jager (University of
Amsterdam) and H. Lemei (Technical University of Delft), and was made pos￾sible through the financial support of the Minister of Education and
Sciences of the Netherlands.
Like the two preceding conferences (North-Holland Mathematics Studies,
Vols. 13 and 21) the aim of this conference was to gather a number of
mathematicians actively engaged in research in the field of differential
equations and thus obtain an up to date picture of the recent developments.
The lectures presented in this volume cover a large variety of aspects
of differential equations, and range from abstract theory to applications.
Following topics may be mentioned a.0.: non-linear differential equations
of elliptic, parabolic and hyperbolic type, upper and lower bounds of so￾lutions, non-linear integral equations, free boundary problems, singular
perturbations and control theory. Further, applications in fluid mechanics,
diffusion problems, wave mechanics, transport theory and epidemiology.
It is a pleasure to acknowledge the gratitude to all authors for their
contributions.