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The effect of particle shape on the properties of granular systems is a matter of great relevance to many diverse fields, yet remains incompletely understood. While the geometry of a particle determines a number of its physical properties, in this study, we isolate the influence of the moment of inertia possessed by a particle on its dynamical behaviour. Through the application of positron emission particle tracking, we experimentally investigate vibrofluidised granulates comprising particles of varying rotational inertia. We demonstrate that beds composed of particles with greater rotational inertia consistently obtain higher translational kinetic energies than those comprising particles with lower angular mass. This observation is shown to be robust over a range of system parameters, and a mechanism explaining the newly observed behaviour is proposed. [ABSTRACT FROM AUTHOR]

For over 20 years the University of Birmingham has been using positron-emitting radioactive tracers to study engineering processes. The imaging technique of positron emission tomography (PET), widely used for medical applications, has been adapted for these studies, and the complementary technique of positron emission particle tracking (PEPT) has been developed. The radioisotopes are produced using the Birmingham MC40 cyclotron, and a variety of techniques are employed to produce suitable tracers in a wide range of forms. Detectors originally designed for medical use have been modified for engineering applications, allowing measurements to be made on real process equipment, at laboratory or pilot plant scale. This paper briefly reviews the capability of the techniques and introduces a few of the many processes to which they have been applied. [ABSTRACT FROM AUTHOR]