Editorial: Powders & Grains 2021 9th International Conference on Micromechanics of Granular Media

Abstract

Granular matter, particulate matter and granular materials are generic terms to refer to systems composed of many macroscopic bodies (grains or particles) where the contact interaction (which is non-conservative) plays a crucial role in the behavior of the system. This contrasts with other systems (e.g., atomic or molecular systems) where the constituent bodies (e.g., atoms or molecules) interact via conservative forces. The non-conservative contact interactions come from inelastic collisions (due to plastic deformation, sound or heat production) and also from friction. This makes the study of granular matter a major challenge to scientists and the handling/storage/processing of granular materials a major challenge to engineers. Particulate matter covers a very broad range of systems, from those formed by fine particles (powders) to those formed by large rocks (derbis), from soft bodies (cotton balls) to hard grains (glass beads), from those we eat (muesli) to those we play with (beach sand), from those used to build our houses (cement) to those used to grow our crops (soil). Needless to say, any new knowledge in this area has a tremendous potential to impact our lives and our economy. Powders & Grains is a conference held every four years to bring together researchers working both in fundamental aspects of granular matter and in technological applications. This volume collects the 195 papers presented during the 2021 edition of P&G, which provide an excellent overview of the current state-of-the-art in granular matter and new trends with contributions form six continents.