Periodic motions galore: How to modify nonlinear evolution equations so that they feature a lot of periodic solutions

A simple trick is illustrated, whereby nonlinear evolution equations can be modified so that they feature a lot - or, in some cases, only -- periodic solutions. Several examples (ODEs and PDEs) are exhibited.Comment: arxiv version is already officia

Algebraically Linearizable Dynamical Systems

The main result of this paper is the evidence of an explicit linearization of dynamical systems of Ruijsenaars-Schneider type and of the perturbations introduced by F. Calogero of these systems with all orbits periodic of same period. Several other systems share the existence of this explicit linearization, among them, the Calogero-Moser system (with and without external potential) and the Calogero-Sutherland system. This explicit linearization is compared with the notion of maximal superintegrability which has been discussed in several articles.Comment: 11 pages, Late

River basin trajectories: societies, environments and development

River basin management / River basin development / Hydrology / Water governance / Water use / History / Water allocation / Water transfer / Water quality / Irrigation management / Groundwater management / Surface irrigation / Water lifting / Pumping / Middle East / Jordan / South Africa / Mexico / Tunisia / Tanzania / Iran / India / China / USA / Australia / Lower Jordan River Basin / Olifants River Basin / Lerma-Chapala River Basin / Mediterranean River Basin / Great Ruaha River / Zayandeh Rud River Basin / Krishna River Basin / Bhavani River Basin / Yellow River Basin / Colorado River Basin / Murray Darling River Basin / Merguellil Basin

Impurity-to-efficiency simulator: Predictive simulation of solar cell efficiencies based on measured metal distribution and cell processing conditions

We present a fast and simple 1D simulation tool to predict solar cell performance as a function of the initial iron content and distribution in the as-grown silicon wafer, the time-temperature profiles applied during the fabrication process, and several parameters related to cell architecture. The applied model consists of three parts that are validated by comparison to experimental results from literature. Assuming a time-temperature profile of a standard solar cell fabrication process, we calculate the redistribution of iron and the evolution of minority carrier lifetime for different as-grown Fe distributions. The solar cell performance as a function of the total iron concentration and the final lifetime distribution is also simulated and compared to experimental results for multicrystalline Si. Keywords: simulation, crystalline silicon solar cell, getterin

Monodromy and the Kowalevskaya top

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