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Tadeusz Marcinkowski
Institute of Technology and Life Sciences, Żuławy Research Centre in Elblag, ul. Giermków 5, 82-300 Elbląg, Poland, phone +48 55 232 44 08
Waldemar Wardencki
Chemical Faculty, Gdansk University of Technology, ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland