1. Tubacex Innovación SL, 48160 Derio, Spain
2. Physics Department, Faculty of Science and Technology, University of the Basque Country, Barrio Sarriena s/n, 48940 Leioa, Spain
3. Tecnalia Research & Innovation, 20009 San Sebastián, Spain
4. Tubacoat SL, 48160 Derio, Spain