TY - JOUR A1 - Kelm, Jürgen A1 - Stark, Wolfgang A1 - Bovtun, V. A1 - Borisov, V. A1 - Yakimenko, Y. T1 - Investigation of Crosslinking Process in Thermosets and Elastomers by Microwave Methods - Basic Study for the Monitoring Method Development KW - Dielectric parameters KW - Microwave methods KW - Crosslinking KW - Cure KW - Vulcanisation KW - Thermosets KW - Elastomers KW - Monitoring PY - 2000 SN - 0025-5300 PB - Carl Hanser Verlag CY - München AN - OPUS4-1053 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bovtun, V. A1 - Stark, Wolfgang A1 - Pashkov, V. A1 - Kelm, Jürgen A1 - Yakimenko, Y. T1 - Microwave On-Line Monitoring of Thermoset Curing PY - 2002 SN - 0025-5300 VL - 44 IS - 7-8 SP - 300 EP - 306 PB - Carl Hanser Verlag CY - München AN - OPUS4-1563 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bovtun, V. A1 - Stark, Wolfgang A1 - Kelm, Jürgen A1 - Porokhonskyy, V. A1 - Yakimenko, Y. T1 - Microwave Dielectric Properties of Rubber Compounds Undergoing Vulcanisation - Part 2. Influence of Carbon Black N2 - The application of microwave measurements to the characterisation of rubber compounds vulcanisation is considered. The behaviour of mechanical and microwave (20 GHz) dielectric parameters during vulcanisation was investigated for rubber compounds with different concentrations of active and non-active carbon black. An increase of concentration or activity of carbon black results in the increase of both dielectric permittivity ε?(T) and loss ε?(T) and in the increase of torsion modulus as well. The start of the vulcanisation reaction is indicated by an increase of dielectric permittivity and torsion modulus in all investigated unvulcanised compounds with carbon black. While for compounds with non-active carbon black the vulcanisation can be better indicated by the ε?(T) anomaly, for compounds with active carbon black it is more clearly seen by the change of ε?(T) behaviour. PY - 2002 UR - http://www.plastverarbeiter.de/ai/resources/d5af83c1e48.pdf SN - 0948-3276 SN - 0022-9520 VL - 55 IS - 1-2 SP - 16 EP - 22 PB - Hüthig CY - Heidelberg AN - OPUS4-1564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bovtun, V. A1 - Sturm, Heinz A1 - Pashkov, V.M. ED - Baptista, J. T1 - Investigation of local electrical properties and topography of homo- and heterogeneous TiO2-containing ceramics by scanning force microscopy (SFM) T2 - 5th International Conference on Electronic Ceramics & Applications CY - Aveiro, Portugal DA - 1996-09-02 KW - Ceramics KW - Scanning force microscopy KW - SFM KW - Electrical properties KW - Heterogeneity PY - 1996 SN - 972-828317-2 VL - 2 SP - 117 EP - 120 PB - Fundação João Jacinto de Magalhães CY - Aveiro AN - OPUS4-6850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Bovtun, V. A1 - Stark, Wolfgang A1 - Kreutzbruck, Marc ED - Kollmeier, B. T1 - Bestimmung der elastischen Eigenschaften des Polypropylen-Ferroelektrets N2 - Ferroelektrete sind zelluläre polarisierte Polymere, die ferroelektrische und dadurch auch piezoelektrische Eigenschaften aufweisen. Unter anderem werden sie für den Bau von Mikrofonen und Ultraschallwandlern für Materialprüfung eingesetzt. Dabei erweist sich ihre besonders niedrige akustische Impedanz als Vorteil. Ursache dafür ist vor allem ihr außergewöhnlich niedriger Elastizitätsmodul in Dickenrichtung. In diesem Beitrag werden zwei Methoden für die Ermittlung des Elastizitätsmoduls des geladenen zellulären Polypropylens (zPP) dargestellt. Die erste ist eine neuartige modellgestützte Methode mittels Laservibrometrie an dem eigenentwickelten Polypropylen-Wandler, wobei die Resonanzschwingung des Wandlers bei 250 kHz gemessen wird. Die zweite Methode ist dynamisch-mechanische Analyse (DMA) durchgeführt mit Frequenzen von 0,3 bis 50 Hz, erstmalig für das zPP angewendet. T2 - DAGA 2014 - 40. Jahrestagung für Akustik CY - Oldenburg, Germany DA - 10.03.2014 PY - 2014 SN - 978-3-939296-06-5 SP - 1 EP - 2 AN - OPUS4-31368 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bovtun, Viktor Petrovic A1 - Döring, Joachim A1 - Wegener, M. A1 - Bartusch, Jürgen A1 - Beck, Uwe A1 - Erhard, Anton A1 - Borisov, V. T1 - Air-coupled ultrasonic applications of ferroelectrets KW - Air-coupled ultrasonics KW - Non-contact transducers KW - Ferroelectrets KW - Electromechanical properties PY - 2008 DO - https://doi.org/10.1080/00150190802380243 SN - 0015-0193 SN - 1563-5112 VL - 370 IS - 1 SP - 11 EP - 17 PB - Taylor & Francis CY - New York, NY AN - OPUS4-20924 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Döring, Joachim A1 - Bovtun, V. A1 - Bartusch, Jürgen A1 - Beck, Uwe A1 - Kreutzbruck, Marc T1 - Cellular polypropylene ferroelectret film: piezoelectric material for non-contact ultrasonic transducers T2 - 17th World Conference on Non-Destructive Testing CY - Shanghai, China DA - 2008-10-25 KW - Air-coupled ultrasound KW - Ultrasonic transducers KW - Electromechanical properties KW - Piezoelectric materials KW - Impedance spectroscopy PY - 2008 IS - Paper 123 SP - 1 EP - 6 PB - International Committee for Non-Destructive Testing CY - Shanghai AN - OPUS4-18435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bovtun, V. T1 - EMFIT Ferroelectret film transducers for non-contact ultrasonic testing T2 - ECNDT 2006, European Conference on Non-Destructive Testing CY - Berlin, Germany DA - 2006-09-25 PY - 2006 AN - OPUS4-12429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bovtun, V. T1 - Air-coupled ultrasonic transducers based on cellular polypropylene ferroelectret films T2 - 8th European Conference on Applications of Polar Dielectrics CY - Metz, France DA - 2006-09-05 PY - 2006 AN - OPUS4-12729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bovtun, V. A1 - Döring, Joachim A1 - Bartusch, Jürgen A1 - Beck, Uwe A1 - Erhard, Anton A1 - Yakymenko, Y. T1 - Air-coupled ultrasonic transducers based on cellular polypropylene ferroelectret films N2 - Analysis of the dielectric and electromechanical properties of the cellular polypropylene ferroelectret films (EMFIT) evidences their high potential for the application in the air-coupled ultrasonic transducers. Simple prototype transducers, based on the EMFIT films, were developed and their high sensitivity was proved in the air-coupled ultrasonic experiment. Amplitude and delay time scanned images of the polyethylene step wedge with holes, obtained in both pulse-echo and transmission modes, demonstrate that non-contact ultrasonic imaging with EMFIT transducers is possible. KW - Air-coupled ultrasonics KW - Non-contact transducers KW - Ferroelectrets KW - Electromechanical properties PY - 2007 SN - 0015-0193 SN - 1563-5112 VL - 353 IS - 1 SP - 186 EP - 192 PB - Taylor & Francis CY - New York, NY AN - OPUS4-14977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -