M. Lindner, W. Sextro, and K. Popp, “Hysteretic Friction of a Sliding Rubber Element,” PAMM, vol. 4, no. 1, pp. 101–102, 2004.

W. Littmann, T. Hemsel, and J. Wallaschek, “Design criteria for piezoelectric transformers,” in Proceedings of the 18th International Congress on Acoustics, 2004, vol. 4, pp. 2889–2892.

M. Mracek, J. Wallaschek, and T. Hemsel, “Self configuration of miniature ultrasonic linear motors,” in Proceedings of the 18th International Congress on Acoustics, 2004, pp. 417–420.

L. Panning, K. Popp, W. Sextro, and F. Götting, “Asymmetrical Underplatform Dampers in Gas Turbine Bladings: Theory and Application,” in Proceedings of ASME TURBO Expo, Power for Land, Sea, and Air, 2004, vol. 6, no. -53316, pp. 269–280.

B. Fu, T. Hemsel, and J. Wallaschek, “Model-based Diagnosis for Sandwiched Ultrasonic Transducers,” in Proceedings of the 18th International Congress on Acoustics, ICA, 2004, pp. 4–9.

F. Götting, W. Sextro, L. Panning, and K. Popp, “Schwingungsverhalten von verstimmten Beschaufelungen mit Reibelementen,” in Schwingungen in rotierenden Maschinen VI SIRM, Referate der Tagung in Darmstadt, 2003, pp. 201–210.

A. Genzo, W. Sextro, and K. Popp, “Erzwungene Schwingungen von elastischen Mehrkörpersystemen mit Reibkontakten,” PAMM, vol. 2, no. 1, pp. 120–121, 2003.

T. Hemsel and J. Wallaschek, “Modelling and Analysis of Piezoelectric Transformers,” in Proceedings of the 5th International Congress of Intelligent Materials (ICIM), 2003.

W. Littmann, T. Hemsel, C. Kauczor, J. Wallaschek, and W. Sinha, “Load-adaptive phase-controller for resonant driven piezoelectric devices,” in Proceedings of World Congress Ultrasonics, 2003, pp. 547–550.

L. Panning, W. Sextro, and K. Popp, “Design of Friction Dampers for Mistuned Bladed Disks,” PAMM, vol. 3, no. 1, pp. 118–119, 2003.

L. Panning, W. Sextro, and K. Popp, “Spatial dynamics of tuned and mistuned bladed disks with cylindrical and wedge-shaped friction dampers,” International Journal of Rotating Machinery, vol. 9, no. 3, pp. 219–228, 2003.

K. Popp, L. Panning, and W. Sextro, “Vibration Damping by Friction Forces -Theory and Applications,” Journal of Vibration and Control, vol. 9, pp. 419–448, 2003.

W. Sextro and K. Popp, “Optimierung des Schwingungsverhaltens elastischer Strukturen mit Reibfugen am Beispiel von Turbomaschinenschaufeln,” in Forschungsvereinigung Verbrennungskraftmaschinen (FW), 2003, no. 753, p. 40.

J. Szwedowicz, W. Sextro, R. Visser, and P. . Masserey, “On forced vibration of shrouded turbine blades,” in ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference, 2003, no. -38808.

T. Hemsel, W. Littmann, and J. Wallaschek, “Piezoelectric transformers - state of the art and development trends,” in Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE, 2002, vol. 1, no. vol.1, pp. 645–648.

T. Hemsel, W. Littmann, and J. Wallaschek, “Piezoelektrische Transformatoren - Bauformen und Modellierung,” in 47. Internationales Wissenschaftliches Kolloquium, 2002.

L. Panning, W. Sextro, and K. Popp, “Optimization of the Contact Geometry between Turbine Blades and Underplatform Dampers with respect to Friction Damping,” in Proceedings of ASME TURBO Expo, Power for Land, Sea, and Air, 2002, no. GT-2002-30429.

L. Panning, W. Sextro, and K. Popp, “Spatial dynamics of tuned and mistuned bladed disks with cylindrical and wedge-shaped friction dampers,” in Proceedings of the 9th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, ISROMAC, 2002.

W. Sextro, L. Panning, and F. Götting, “Fast Calculation of the Statistics of the Forced Response of Mistuned Bladed Disk Assemblies with Friction Contacts,” in Proceedings of ASME TURBO Expo, Power for Land, Sea, and Air, 2002, no. GT-2002-30427.

W. Sextro and K. Popp, “Optimierung des Schwingungsverhaltens elastischer Strukturen mit Reibfugen,” in Forschungsvereinigung Verbrennungskraftmaschinen (FW) - lnformationstagung Turbinen, 2002, no. 518, pp. 157–183.