1. Department of Structural EngineeringFaculty of Civil EngineeringSilesian University of Technology Akademicka 5 44‐100 Gliwice Poland
2. Université de StrasbourgCNRS, ISIS 8 alleé Gaspard Monge 67000 Strasbourg France
3. Faculty of ChemistryAdam Mickiewicz University Umultowska 89b 61‐614 Poznań Poland
4. Centre for Advanced TechnologiesAdam Mickiewicz University Umultowska 89c 61‐614 Poznań Poland