@phdthesis{65309, author = {{Hemmrich, Simon}}, keywords = {{Reputation Systems, Rating systems, monetary ratings, incentive mechanism, systems theory, Market coordination, advanced review system}}, pages = {{347}}, publisher = {{Universität Paderborn}}, title = {{{A Design Theory for Blockchain-Based Reputation Systems : Trust and Coordination in B2B Markets}}}, doi = {{https://doi.org/10.17619/UNIPB/1-2414}}, year = {{2025}}, } @inproceedings{64803, abstract = {{Nowadays ultrasound technology is established in various fields of application like industrial production or medical technology. Besides high power ultrasound applications like ultrasonic cleaning and ultrasonic welding, which are often not strongly restricted regarding their weight, costs, and construction space, there are many applications in the low to medium power range like handheld surgical instruments, medical inhalers, or ultrasonic cutters. For the latter there is often a strong demand for low weight and construction space and low costs to be competitive in mass production. Another challenge that arises from the RoHS-directive [1] is, that new ultrasonic devices should avoid the use of lead-containing PZT-materials. Against this background there is a demand for lead-free, small and lightweight and cost-effective ultrasonic transducers. In many of the above-mentioned applications, pre-stressed Bolted-Langevine-Transducers (BLT) based on lead-containing PZT-materials are established to generate ultrasonic vibrations. These are quite advantageous in many ways and can be built tailored to each application and even for high power of thousands of watts. But due to the required steps during their manufacturing process (machining parts, assembly, pre-stressing, frequency tuning, …), these transducers remain expensive. Furthermore, due to the operation in resonance, the construction space of these transducers is linked to their wavelength and cannot be reduced remarkably. For these reasons, our aim is to present an innovative lead-free ultrasonic transducer for low to medium power applications, that is based on bending vibrations instead of longitudinal vibrations. This design enables to build very small transducers. Furthermore, due to their simple construction, these transducers can be built at low manufacturing costs and are well suited for industrial mass production. The use of lead-free piezoelectric materials makes this transducer design ready for future applications. In our contribution we will present the model-based design of a lead-free 30 kHz bending transducer for applications up to 10 W. Furthermore, the comprehensive experimental analysis of this transducer-prototype in applications like mist generation or ultrasonic drilling will be presented. The results will be compared to a PZT-based bending transducer and a classical BLT to show the potential and limits of these kind of transducers and lead-free materials. }}, author = {{Bornmann, Peter and Littmann, Walter and Scheidemann, Claus and Hemsel, Tobias}}, location = {{Paderborn, Germany}}, title = {{{Innovative lead-free ultrasonic bending transducers for low to medium power applications}}}, year = {{2025}}, } @inproceedings{64802, abstract = {{Power ultrasonic actuators are used in various industrial, automotive and medical applications. Examples are ultrasonic welding of plastics or metal, surgery processes like cutting of tissue or bone, and the excitation of cavitation in liquids for ultrasonic cleaning. From a physical point of view, many of these processes are characterised by non-constant damping conditions for the ultrasonic actuators, since the systems need to be driven in unloaded as well as in high-loaded states. To get high power output, the piezoelectric actuators are usually driven in or near resonance at precisely defined vibration amplitudes. This is a quite complicated task especially if cost or mass optimized PZT transducers are used or if lead-free piezoelectric ceramics are applied to replace lead-containing materials. In particular the sudden change between loading states is very challenging for electronic excitation and control. The present contribution gives insight into typical problems that may arise in context with sudden load-changes during operation, e.g. uncontrolled jumps in voltage and velocity amplitudes. Measurements on ultrasonic power actuators being abruptly immersed into water at high amplitude are discussed for illustration. Observations during spontaneous load-changes are explained, and it is shown that several problems may be defused by driving the actuators in antiresonance or using a particular driving point in-between resonance and antiresonance (“falling edge control”). The different control strategies are investigated always using just one single hardware.}}, author = {{Littmann, Walter and Bornmann, Peter and Hemsel, Tobias and Scheidemann, Claus}}, location = {{Paderborn, Germany}}, title = {{{Power ultrasonic actuators with suddenly changing loads: How to control the amplitudes in resonance, antiresonance, or in-between}}}, year = {{2025}}, } @book{65272, editor = {{Droß-Krüpe, Kerstin}}, title = {{{(mit K. Ruffing) Von Gerste, Göttern, Geld und Gesetzen. Eine Kultur- und Wirtschaftsgeschichte von Bier in der Antike}}}, volume = {{2}}, year = {{2025}}, } @misc{65346, author = {{Droß-Krüpe, Kerstin}}, booktitle = {{The Oxford Classical Dictionary}}, title = {{{Semiramis}}}, year = {{2025}}, } @misc{65345, author = {{Droß-Krüpe, Kerstin}}, booktitle = {{The Oxford Classical Dictionary}}, title = {{{Sardanapalus}}}, year = {{2025}}, } @inbook{65288, author = {{Droß-Krüpe, Kerstin}}, booktitle = {{Das achaimenidisch-persische Imperium}}, editor = {{Degen, J.}}, pages = {{339--347}}, title = {{{Frauenbilder und -rollen}}}, year = {{2025}}, } @inbook{65287, author = {{Droß-Krüpe, Kerstin}}, booktitle = {{Kriegerinnen im Altertum}}, editor = {{Diemke-Horst, J. and Mörtz, T.}}, pages = {{67--81}}, title = {{{Frauen als Gewalttäterinnen? Erste Überlegungen auf Basis von Petitionen aus dem griechisch-römischen Ägypten}}}, volume = {{14}}, year = {{2025}}, } @inbook{65289, author = {{Droß-Krüpe, Kerstin}}, booktitle = {{Das achaimenidisch-persische Imperium}}, editor = {{Degen, J.}}, pages = {{375--381}}, title = {{{Atossa}}}, year = {{2025}}, } @article{60360, author = {{Fuchs, Christian}}, journal = {{St. Anthony’s International Review}}, number = {{1}}, pages = {{26--39}}, title = {{{What is Digital Fascism? }}}, doi = {{10.82556/stair.v20i1.550}}, volume = {{20}}, year = {{2025}}, } @misc{65273, booktitle = {{Arenal. Revista de historia de las mujeres}}, editor = {{Droß-Krüpe, Kerstin and Garcia Ventura, Agnès}}, pages = {{7--124}}, title = {{{Pasados presentes. La construcción de estereotipos de género en la recepción del mundo antiguo}}}, volume = {{32/1}}, year = {{2025}}, } @inbook{60605, author = {{Diederich, Julia and Magdeburg, Lena Maria}}, booktitle = {{Sexuelle Bildung in der Grundschule und der universitären Lehrer*innenausbildung. Perspektiven aus Forschung, Praxis und Lehre}}, editor = {{Struck, Constanze and Warburg, Saskia}}, pages = {{57--66}}, publisher = {{Verlag Barbara Budrich}}, title = {{{Sexuelle Bildung und (außer-)schulische Bildungspartner}}}, year = {{2025}}, } @misc{65221, author = {{Kullmer, Gunter and Weiß, Deborah and Duffe, Tobias and Schramm, Britta and Ostwald, Richard}}, publisher = {{LibreCat University}}, title = {{{BESCHREIBUNG DES R- UND DES TEMPERATUREINFLUSSES SOWIE DES EINLAUFVERHALTENS BEI EXPERIMENTELL BESTIMMTEN RISSFORTSCHRITTSKURVEN MIT DEM EXPONENTIALANSATZ}}}, doi = {{https://doi.org/10.48447/BR-2025-492}}, year = {{2025}}, } @misc{63753, author = {{Diederich, Julia}}, title = {{{Rezension von: Julia Peuke: Was bleibt - die DDR aus der Perspektive von Kindern: eine qualitative Studie zum historisch-politischen Lernen im Sachunterricht}}}, year = {{2025}}, } @inbook{65068, author = {{Büttner, Denise}}, booktitle = {{ Literarische Textualität und ästhetische Medialität in Deutsch als Zweitsprache (DaZ). Spannungsfelder – Potenziale – Perspektiven }}, editor = {{Dobstadt, Michael}}, isbn = {{9783863956677}}, issn = {{2751-5818}}, location = {{TU Dresden}}, publisher = {{Göttingen University Press}}, title = {{{„Und ich hab’ euch jetzt mal ottos mops auf Englisch mitgebracht“ - Gedanken zu sprachlichen Ordnungen im ‚mehrsprachigen Literaturunterricht‘}}}, doi = {{10.17875/gup2025-3002}}, volume = {{112}}, year = {{2025}}, } @article{63100, author = {{Kundisch, Dennis and Wilms, Alexander}}, journal = {{Journal of Small Business and Enterprise Development}}, number = {{1}}, pages = {{49 -- 71}}, title = {{{From mismatch to synergy: how new ventures and family-owned firms navigate cooperation}}}, doi = {{10.1108/JSBED-07-2025-0474}}, volume = {{3}}, year = {{2025}}, } @inbook{45827, author = {{Cao, Chuntian and Steinrück, Hans-Georg}}, booktitle = {{Reference Module in Chemistry, Molecular Sciences and Chemical Engineering}}, isbn = {{9780124095472}}, pages = {{391--416}}, publisher = {{Elsevier}}, title = {{{Molecular-scale synchrotron X-ray investigations of solid-liquid interfaces in lithium-ion batteries}}}, doi = {{10.1016/b978-0-323-85669-0.00105-7}}, year = {{2024}}, } @misc{48363, author = {{Foerster, Anne}}, booktitle = {{Women in Early Medieval England}}, editor = {{Butler, Emily and Dumitrescu, Irina}}, publisher = {{Springer Textbook}}, title = {{{The Swineherd’s Wife who Scolded the King}}}, year = {{2024}}, } @misc{48362, author = {{Foerster, Anne}}, booktitle = {{Women in Early Medieval England}}, editor = {{Butler, Emily and Dumitrescu, Irina}}, publisher = {{Springer Textbook}}, title = {{{Eadburh of Wessex}}}, year = {{2024}}, } @misc{48364, author = {{Foerster, Anne}}, booktitle = {{Women in Early Medieval England}}, editor = {{Butler, Emily and Dumitrescu, Irina}}, publisher = {{Springer Textbook}}, title = {{{Seaxburh}}}, year = {{2024}}, }