A non-ideal portal frame energy harvester controlled using a pendulumI. Iliuk, J.M. Balthazar, A.M. Tusset, J.R.C. Piqueira, B. Rodrigues de Pontes, J.L.P. Felix and Á.M. BuenoEur. Phys. J. Special Topics, 222 7 (2013) 1575-1586DOI: https://doi.org/10.1140/epjst/e2013-01946-4