Can stochastic resonance explain recurrence of Grand Minima?

The amplitude of the 11 yr solar cycle is well known to be subject to long-term modulation, including sustained periods of very low activity known as Grand Minima. Stable long-period cycles found in proxies of solar activity have given new momentum to the debate about a possible influence of the tiny planetary tidal forcing. Here, we study the solar cycle by means of a simple zero-dimensional dynamo model, which includes a delay caused by meridional circulation as well as a quenching of the α-effect at toroidal magnetic fields exceeding an upper threshold. Fitting this model to the sunspot record, we find a set of parameters close to the bifurcation point at which two stable oscillatory modes emerge. One mode is a limit cycle resembling normal solar activity including a characteristic kink in the decaying limb of the cycle. The other mode is a weak sub-threshold cycle that could be interpreted as Grand Minimum activity. Adding noise to the model, we show that it exhibits Stochastic Resonance, which means that a weak external modulation can toss the dynamo back and forth between these two modes, whereby the periodicities of the modulation get strongly amplified

Economical exploitation of polymer coated steel sheet in large-scale production of new can types by the European can industry

This report presents review of the state of the art of numerical modelling of polymers and polymer coated metal laminates and gives details of selected numerical models including those that will be used in the work in the project POLYCOAT. The first sections of the report contain characteristics of polymers which are important for the application studied in the project. Basic mechanical and thermal properties of the polymers are reviewed. Then constitutive models developed for polymers are reviewed based on literature and own work. Details of selected models are given. Deformation behavior of polymer coated metal laminates is considered with special attention to the phenomena at the polymer-metal interface. The numerical models for the interface are presented finally. &nbsp