TY - CONF A1 - Döring, Joachim A1 - Bovtun, V. A1 - Bartusch, Jürgen A1 - Beck, Uwe A1 - Yakymenko, Y. T1 - Cellular polypropylene ferroelectret Piezoelectrics for the air-coupled Ultrasonics T2 - Euromat 2007 T2 - Euromat 2007 CY - Nuremberg, Germany DA - 2007-09-10 PY - 2007 AN - OPUS4-15757 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -