@article{60050,
  abstract     = {{Reputation systems to rate companies’ performances remain largely unexplored inresearch and are scarcely used in business-to-business (B2B) practice. Such systemsare essential for businesses seeking trustworthy partners, as they help reduce infor-mation asymmetry, lower buyers’ transaction risks, and allow high-quality serviceproviders to justify premium pricing. Unlike traditional review-based systems in thebusiness-to-consumer (B2C) context, we propose a B2B reputation mechanism inwhich buyers commit to a rating payment before a transaction. Once the buyer final-izes the rating, this payment is executed and recorded on a blockchain as an immu-table, secure ledger. Our system mimics natural trust-building mechanisms with rat-ings that are (1) monetary-based, (2) stake-based, (3) non-aggregated, (4) involvecounter-ratings, (5) selectively sellable, (6) individually comparable, (7) stored ona blockchain, (8) and monitored by a third instance. This system provides a novelapproach to fostering trust in B2B transactions by reducing information asymme-try and transaction risk. We illustrate the mechanism’s application in the consultingsector. Our analysis has identified 23 institutional trust and distrust dimensions thatpromote establishing institutional trust through the proposed mechanism. Qualita-tive interviews suggest that, while complex and challenging to apply, this mecha-nism can foster trust in B2B transactions. Given the low maturity in the applicationdomain—rating professional business services with business reputation systems—and solution domain—using monetary stakes for ratings, this system stands as apotential invention.}},
  author       = {{Hemmrich, Simon and Nissen, Volker and Beverungen, Daniel and Pauls, Josias Daniel Miño}},
  journal      = {{Information Systems and e-Business Management}},
  keywords     = {{Information asymmetry, Trust, Reputation system, Monetary rating, Blockchain, Consulting}},
  number       = {{1}},
  publisher    = {{Springer}},
  title        = {{{Blockchain‑based reputation systemsfor business‑to‑business services: designing a reputation mechanism to reduce information asymmetry in professional consulting}}},
  doi          = {{https://doi.org/10.1007/s10257-025-00702-9}},
  volume       = {{23}},
  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}},
}

@phdthesis{50530,
  abstract     = {{Die Extrusion stellt das mengenmäßig dominante Verarbeitungsverfahren für thermoplastische Kunststoffe dar. Daher gibt es starke Bestrebungen in diesem Bereich hin zu einer höheren Wirtschaftlichkeit, welche beispielsweise durch höheren Massedurchsatz bei gleichbleibender Maschinengröße erreicht werden kann, oder aber auch im Hinblick auf eine Kreislaufwirtschaft die Bestrebung hin zu einer materialschonenden Verarbeitung. Beide Bestrebungen erfordern spezielle Schneckenkonzepte. Hierunter fallenWave- Schnecken, welche in beiden Bereichen ein vorteilhaftes Prozessverhalten aufzeigen sollen. Die Auslegung von Wave-Schnecken erfordert jedoch ein stärkeres Verständnis über das geometrieabhängige Prozessverhalten in der Extrusion. 
Im Rahmen der Dissertation werden zwei Themengebiete angegangen. Das erste Thema ist die Herleitung einer Methode zur Charakterisierung des Abbauverhaltens von Thermoplasten sowie die Nutzung der Charakterisierung als Vorhersagemodell. Das zweite Thema behandelt die Auslegung von Wave-Schnecken basierend auf numerischen Simulationen samt Validierung anhand von sieben Energy-Transfer-Schnecken im Vergleich zu drei konventionellen Schnecken. Hierbei werden unter anderem der Materialabbau, die thermische und die stoffliche Homogenität betrachtet, um ein umfassendes Bild über das Prozessverhalten der Schnecken zu schaffen. Die vorgestellten Untersuchungen dienen schlussendlich zu einer Bestätigung des vorteilhaften Prozessverhaltens von Wave-Schnecken.}},
  author       = {{Schall, Christoph Wilhelm Theodor}},
  isbn         = {{978-3-8440-9334-6}},
  pages        = {{224}},
  publisher    = {{Shaker Verlag}},
  title        = {{{Materialschonende Verarbeitung von Thermoplasten auf Wave-Schnecken}}},
  volume       = {{Band 2/2024}},
  year         = {{2024}},
}

@article{50841,
  author       = {{Moretto, Giordano  and Schnell, Nicolas  and Frey, Jonathan  and Karakaya, Yasin and Amstutz, Alois and Diehl, Moritz and Kasper, Tina and Onder, Christopher}},
  journal      = {{Control Engineering Practice}},
  pages        = {{105848}},
  title        = {{{Fast model-based calibration of multiple injections for a CI engine using nonlinear optimal control}}},
  doi          = {{10.1016/j.conengprac.2024.105848}},
  volume       = {{145}},
  year         = {{2024}},
}

@inbook{49813,
  author       = {{Taschl-Erber, Andrea and Woppowa, Jan}},
  booktitle    = {{Elementare Bibeltexte }},
  editor       = {{Rothgangel, Martin  and Simojoki, Henrik and Gerber, Christine and Michel, Andreas}},
  pages        = {{459–472}},
  title        = {{{Gottes Treue zu Israel (Röm 9–11)}}},
  volume       = {{2}},
  year         = {{2024}},
}

@misc{51133,
  abstract     = {{In order to standardize spray flame synthesis (SFS) studies, intensive work has been done in recent years on the design of burner types. Thus, in 2019, the so-called SpraySyn1 burner was introduced (SS1), which was subsequently characterized in numerical and experimental studies. Based on this research, a modification of the nozzle design was proposed, which has now been considered in the successor model, SpraySyn2 (SS2). As little is known about the effect of the nozzle adaptation on the particle formation, we operated both burners under identical operating conditions to produce maghemite. The final powder comparison showed that SS2 yielded considerable higher specific surface areas (associated with smaller primary particle sizes), lower polydispersity, and higher phase purity. To obtain further information on the size distributions of aggregates and agglomerates generated by SS2, aerosol samples were extracted by hole in a tube (HIAT) sampling and characterized by scanning mobility particle sizing (SMPS). Samples were extracted along the centerline at different heights above the burner (HAB) above the visible flame tip (>7 cm), and quenching experiments were performed to extract the aerosol samples at different dilution rates. Thereby, it was demonstrated that performing detailed quenching experiments is crucial for obtaining representative HIAT-SMPS data. In particular, agglomerates/aggregate sizes were overestimated by up to ~70 % if samples were not sufficiently diluted. If sufficient dilution was applied, distribution widths and mean particle mobility diameters were determined with high accuracy (sample standard derivation <5 %). Our data suggested the evolution of primary particle sizes was mostly completed <7 cm HAB and it was shown aggregates/agglomerates present above the visible flame were compact in structure (non- fractal). The mean diameter of the particle ensemble grew along the centerline from 6.9 nm (7 cm) to 11.4 nm (15 cm), while distribution widths grew from 1.42 to 1.52.}},
  booktitle    = {{Applications in Energy and Combustion Science}},
  editor       = {{Tischendorf, Ricardo and Massopo, Orlando and Schmid, Hans-Joachim and Pyrmak, Olek and Dupont, Sophie and Fröde, Fabian and Pitsch, Heinz and Kneer, Reinhold}},
  keywords     = {{Flame Spray Pyrolysis, SpraySyn2, Spray flame synthesis, Maghemite nanoparticles, Gas to particle-conversion, Hole in a tube sampling}},
  publisher    = {{Elsevier}},
  title        = {{{Maghemite nanoparticles synthesis via spray flame synthesis and particle characterization by hole in a tube sampling and scanning mobility particle sizing (HIAT-SMPS)}}},
  doi          = {{https://doi.org/10.1016/j.jaecs.2023.100235}},
  year         = {{2024}},
}

@misc{50816,
  author       = {{Hücker, Lars}},
  title        = {{{Stickstoff basierte Flammschutzmittel für das Lasersintern: Optimierung und Analyse der Recyclingfähigkeit (Studienarbeit)}}},
  year         = {{2024}},
}

@misc{50815,
  author       = {{Schulz, Maurice}},
  title        = {{{Phosphorhaltige Lasersinter-Materialien mit Flammschutzwirkung: Optimierung und Analyse der Recyclingfähigkeit (Studienarbeit)}}},
  year         = {{2024}},
}

@misc{51724,
  author       = {{Bablitzka, Nico Janosch and Beimdiek, Janis}},
  title        = {{{Einfluss von Temperatur und Strömungsführung auf die NH3-SCO sowie die NH3-SCR mit Partikeln aus einer Sprayflammensynthese}}},
  year         = {{2024}},
}

@phdthesis{51732,
  author       = {{Richters, Maximilian}},
  title        = {{{Herstellung und Charakterisierung von Wood-Plastic-Composites (WPC) mit einer Matrix aus thermoplastischen Polyurethanen zur Erzeugung einer Holz-WPC-Verbundstruktur }}},
  year         = {{2024}},
}

@article{51737,
  author       = {{Kullmer, Gunter and Weiß, Deborah and Schramm, Britta}},
  issn         = {{0013-7944}},
  journal      = {{Engineering Fracture Mechanics}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
  publisher    = {{Elsevier BV}},
  title        = {{{An alternative and robust formulation of the fatigue crack growth rate curve for long cracks}}},
  doi          = {{10.1016/j.engfracmech.2023.109826}},
  volume       = {{296}},
  year         = {{2024}},
}

@article{52201,
  author       = {{Han, Daxin and Kappe, Fabian and Vorderbrüggen, Julian and Jendrny, Jörg and Gorr, Eugen and Meschut, Gerson}},
  issn         = {{1526-6125}},
  journal      = {{Journal of Manufacturing Processes}},
  keywords     = {{Industrial and Manufacturing Engineering, Management Science and Operations Research, Strategy and Management}},
  pages        = {{92--108}},
  publisher    = {{Elsevier BV}},
  title        = {{{Single-step self-punching lockbolt process for aluminum sheets without pre-hole}}},
  doi          = {{10.1016/j.jmapro.2024.02.043}},
  volume       = {{116}},
  year         = {{2024}},
}

@article{52217,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Polycarbonate (PC) is an amorphous polymer that is an extremely robust material with a high tenacity, and thus suitable for a lightweight construction with glass‐like transparency. Due to these advantageous properties, PC is often used in industry for example in medical devices, automotive headlamps, sporting equipment, electronics, and a variety of other products. PC is often subjected to uniaxial and biaxial loading conditions. Therefore, reliable material models have to take into account the various resulting experimental effects. For those reasons, we investigate PC specimens under uniaxial and biaxial loading by using different stretch rates and loading scenarios. In addition to that, we propose methods for optical measurement of local stretches to obtain the approximated local true stress. In future work, the displacement fields and the resulting reaction forces will be used for parameter identification of constitutive equations.</jats:p>}},
  author       = {{Hamdoun, Ayoub and Mahnken, Rolf}},
  issn         = {{1617-7061}},
  journal      = {{PAMM}},
  keywords     = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics}},
  publisher    = {{Wiley}},
  title        = {{{Experimental investigations of uniaxial and biaxial cold stretching within PC‐films and bars using optical measurements}}},
  doi          = {{10.1002/pamm.202300114}},
  year         = {{2024}},
}

@article{52218,
  author       = {{Lenz, Peter and Mahnken, Rolf}},
  issn         = {{0020-7683}},
  journal      = {{International Journal of Solids and Structures}},
  keywords     = {{Applied Mathematics, Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science, Modeling and Simulation}},
  publisher    = {{Elsevier BV}},
  title        = {{{Multiscale simulation of polymer curing of composites combined mean-field homogenisation methods at large strains}}},
  doi          = {{10.1016/j.ijsolstr.2023.112642}},
  volume       = {{290}},
  year         = {{2024}},
}

@inproceedings{52215,
  author       = {{Carillo Beber, Vinicius and Fernandes, Pedro and Nagel, Christof and Köster, Christian and Matzenmiller, Anton and Hecht, Mathias and Baumgartner, Jörg and Melz, Tobias and Tews, Karina and Çavdar, Serkan and Meschut, Gerson}},
  booktitle    = {{24. Kolloquium: Gemeinsame Forschung in der Klebtechnik}},
  location     = {{Köln}},
  title        = {{{Lebensdauerprognose für Stahlklebverbindungen bei multiaxialer Belastung mit Phasenverschiebung, veränderlicher Mittelspannung und variablen Amplituden}}},
  year         = {{2024}},
}

@inproceedings{52212,
  author       = {{Tews, Karina and Teutenberg, Dominik and Meschut, Gerson and Buczek, Moritz and Duffe, Tobias and Kullmer, Gunter}},
  booktitle    = {{24. Kolloquium: Gemeinsame Forschung in der Klebtechnik}},
  location     = {{Köln}},
  title        = {{{Bruchmechanisches Schnittebenenkonzept zur lebensdauergerechten Auslegung von hyperelastischen Klebverbindungen bei multiaxialen und variablen Belastungsamplituden}}},
  year         = {{2024}},
}

@article{52357,
  author       = {{Beimdiek, Janis and Schmid, Hans-Joachim}},
  issn         = {{2073-4433}},
  journal      = {{Atmosphere}},
  keywords     = {{surrogate aerosols, indoor air cleaners, ultra-fine particles, COVID-19, test method, field experiments: clean air delivery rate}},
  number       = {{3}},
  publisher    = {{Multidisciplinary Digital Publishing Institute (MDPI)}},
  title        = {{{Evaluation of Surrogate Aerosol Experiments to Predict Spreading and Removal of Virus-Laden Aerosols}}},
  doi          = {{ 10.3390/atmos15030305}},
  volume       = {{15}},
  year         = {{2024}},
}

@inproceedings{52359,
  author       = {{Chudalla, Nick and Schmolke, Tobias and Meschut, Gerson and Spohr, Sebastian and Eckstein, Lutz and Brunner-Schwer, Christian and Rethmeier, Michael and Nothelfer-Richter, Rolf and Hilt, MIchael}},
  booktitle    = {{24. Kolloquium: Gemeinsame Forschung in der Klebtechnik}},
  location     = {{Köln}},
  title        = {{{Konzeptentwicklung für ein Stahlbatteriegehäuse unter besonderer Berücksichtigung der Fügetechnik und des Korrosionsschutzes}}},
  year         = {{2024}},
}

@article{52097,
  author       = {{Hami Dindar, Iman and Mirzaei, Mona and Baumhögger, Elmar and Lutters, Nicole and Kenig, Eugeny Y.}},
  issn         = {{0021-9568}},
  journal      = {{Journal of Chemical & Engineering Data}},
  keywords     = {{General Chemical Engineering, General Chemistry}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Experimental and Theoretical Investigation of CO2 Absorption in Aqueous Solution of Glucosamine: Material Property and Equilibrium Data}}},
  doi          = {{10.1021/acs.jced.3c00554}},
  year         = {{2024}},
}