This volume explores the intersections of four fundamental fields within mathematical physics and continuum mechanics. It aims to bridge the gap between typically independent areas of research, namely partial differential equations, variational methods, fluid mechanics, and thermodynamics, by showcasing their deep historical roots and ongoing relevance. The collection is dedicated to honoring James Serrin, whose work exemplified the frequent interaction between these disciplines.

The collection is presented as a tribute to James Serrin, highlighting the interconnectedness of research in partial differential equations, variational methods, fluid mechanics, and thermodynamics. The stated purpose is to bring together work from fields that, while often pursued independently, share remarkable interrelations. The volume's structure suggests a focus on advanced mathematical and physical concepts, likely appealing to researchers and academics in these specialized areas.