@article{59532,
  author       = {{Knorr, Lukas and Buchenau, N. and Schlosser, Florian and Divkovic, Denis and Prina, M.G. and Meschede, Henning}},
  issn         = {{1364-0321}},
  journal      = {{Renewable and Sustainable Energy Reviews}},
  publisher    = {{Elsevier BV}},
  title        = {{{Electrification and flexibility of process heat in energy system modelling: A review}}},
  doi          = {{10.1016/j.rser.2025.115698}},
  volume       = {{216}},
  year         = {{2025}},
}

@inproceedings{59683,
  abstract     = {{Woven fibre-reinforced polymers are used in a variety of application, especially where a low mass to stiffness ratio is required. Of paramount importance for the tailored mechanical properties these composite materials exhibit is the type and geometry of the fibre weave. Especially continuous fibre-reinforced thermoplastic composites are fabricated as laminates and subsequently exposed to forming processes which alter the geometry of the fibres unit cell and thus the local mechanical properties of the material. An approach utilising broadband ultrasonic waves is proposed to non-destructively determine the geometry of the unit cell of the weave.

The dispersive behaviour of woven fibre-reinforced sheets is described in accordance with the Flouquet-Bloch theorem as a phononic crystal. In order to develop a model for a description of these periodically structured waveguides, the smallest repeating unit of the wave is modelled with periodic boundary conditions. The resulting dispersion diagram exhibits similarities to that of a homogeneous plate, but additionally displays a periodicity in the wavenumber regime, which correspond with the size of the unit cell. Experimental studies of the dispersive behaviour of acoustic waves in woven fibre-reinforced samples also show a periodicity in the wavenumber regime, enabling a measurement procedure of the unit cell geometry.}},
  author       = {{Wippermann, Mareen and Claes, Leander and Brandes, Philipp and Moritzer, Elmar and Henning, Bernd}},
  location     = {{Copenhagen}},
  title        = {{{Determination of the unit cell geometry in fibre-reinforced polymer sheets using guided acoustic waves}}},
  doi          = {{10.71568/DASDAGA2025.116}},
  year         = {{2025}},
}

@inproceedings{59688,
  author       = {{Claes, Leander and Zeipert, Henning and Brandes, Philipp and Moritzer, Elmar and Henning, Bernd}},
  location     = {{Copenhagen}},
  title        = {{{Assessment of Fibre-Matrix Adhesion in Reinforced Polymers by Modal Damping of Guided Acoustic Waves}}},
  doi          = {{10.71568/DASDAGA2025.052}},
  year         = {{2025}},
}

@article{59805,
  abstract     = {{The LLC converter achieves the highest efficiency in resonant operation. Conventionally, the input DC-link voltage is controlled to operate the LLC converter at resonance for the given operating point. However, the DC-link capacitor voltage shows a low-frequency voltage ripple (typically the second harmonic of grid frequency) in cascaded converters so that the LLC has to adapt its switching frequency within the grid period. Conventionally, the LLC converter operates 50% of the time above the resonant frequency of 40 kHz and 50% below resonance. Both operating conditions cause additional losses. However, experimental measurements indicate that the below-resonance operation causes significantly higher losses than above-resonance operation due to much higher primary and secondary transformer currents. It is better to increase the DC-link voltage by 30% of the peak-to-peak low-frequency voltage ripple to mostly avoid below-resonance operation (i.e., from 650 V to 680 V in this case). With the proposed control, the LLC converter operates about 75% of time over resonance and only 25% of time below resonance. The overall efficiency increases from 97.66% to 97.7% for the average operating point with an 80% load current. This corresponds to a 2% total loss reduction. Finally, the peak resonance capacitor voltage decreases from 910 V to 790 V (−13%).}},
  author       = {{Unruh, Roland and Böcker, Joachim and Schafmeister, Frank}},
  issn         = {{2079-9292}},
  journal      = {{Electronics}},
  keywords     = {{adaptive DC-link voltage, cascaded H-bridge, resonant operation, Full-Bridge Converter, loss minimization, LLC Resonant Converter, peak capacitor voltage reduction}},
  number       = {{8}},
  publisher    = {{MDPI AG}},
  title        = {{{Adaptive DC-Link Voltage Control for 22 kW, 40 kHz LLC Resonant Converter Considering Low-Frequency Voltage Ripple}}},
  doi          = {{10.3390/electronics14081517}},
  volume       = {{14}},
  year         = {{2025}},
}

@inproceedings{59999,
  author       = {{Rautenberg, Frederik and Kuhlmann, Michael and Seebauer, Fritz and Wiechmann, Jana and Wagner, Petra and Haeb-Umbach, Reinhold}},
  booktitle    = {{ICASSP 2025 - 2025 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)}},
  location     = {{Hyderabad, India }},
  publisher    = {{IEEE}},
  title        = {{{Speech Synthesis along Perceptual Voice Quality Dimensions}}},
  doi          = {{10.1109/icassp49660.2025.10888012}},
  year         = {{2025}},
}

@article{59531,
  author       = {{Ahmadi, Mehdi and Knorr, Lukas and Meschede, Henning}},
  issn         = {{0960-1481}},
  journal      = {{Renewable Energy}},
  publisher    = {{Elsevier BV}},
  title        = {{{Improvement of Wind Power Utilization Through Flexible Operation of Data Center in Wind Parks}}},
  doi          = {{10.1016/j.renene.2025.123073}},
  year         = {{2025}},
}

@article{59995,
  abstract     = {{<jats:title>Abstract</jats:title>
               <jats:p>Ultrasonic transmission measurements can be used for material characterization, as the propagation time of sound waves and thus their velocity depends on the elastic material parameters. Measurement results for the elastic material parameters are acquired non-destructively using ultrasonic transmission measurements of hollow cylindrical polymer specimens. To determine the material parameters, an inverse approach is used comparing measurements with simulated data. Previous studies show that the procedure exhibits low sensitivity with respect to the shear parameters of the material. In order to increase the sensitivity, we propose to apply a spatially annular excitation on the base of the specimen. As a measure to analyse the sensitivities with respect to all parameters and their linear independence, we observe the volume of the parallelotope of the sensitivity vectors. Here, a scaled boundary finite element formulation of wave propagation in the specimen is expanded to yield derivative information directly, and a sensitivity analysis can be carried out efficiently. Finally, the results of this sensitivity analysis with regard to the annular excitation are also applied to the measurement setup.</jats:p>}},
  author       = {{Dreiling, Dmitrij and Itner, Dominik and Gravenkamp, Hauke and Claes, Leander and Birk, Carolin and Henning, Bernd}},
  issn         = {{0957-0233}},
  journal      = {{Measurement Science and Technology}},
  keywords     = {{Sensitivity analysis, Ultrasonic transducer, Guided waves, Polymers, Gram determinant}},
  publisher    = {{IOP Publishing}},
  title        = {{{Increasing the sensitivity of ultrasonic transmission measurements for elastic material parameter estimation}}},
  doi          = {{10.1088/1361-6501/add9b6}},
  volume       = {{36}},
  year         = {{2025}},
}

@article{60081,
  author       = {{Naumann, Marius and Ostermann, Moritz and Buchenau, Nadja and Oetzel, Jannik and Schlosser, Florian and Meschede, Henning and Tröster, Thomas}},
  issn         = {{0196-8904}},
  journal      = {{Energy Conversion and Management}},
  publisher    = {{Elsevier BV}},
  title        = {{{Energy efficiency improvement for decarbonization in manufacturing industry: A review}}},
  doi          = {{10.1016/j.enconman.2025.119763}},
  volume       = {{338}},
  year         = {{2025}},
}

@inproceedings{62300,
  author       = {{Claes, Leander and Hölscher, Jonas and Friesen, Olga and Scheidemann, Claus and Hemsel, Tobias and Henning, Bernd}},
  booktitle    = {{2025 International Congress on Ultrasonics}},
  pages        = {{142–145}},
  publisher    = {{AMA Service GmbH}},
  title        = {{{Estimation of third order elastic constants of piezoceramics using DC biased impedance measurements}}},
  doi          = {{10.5162/ultrasonic2025/a18-a6}},
  year         = {{2025}},
}

@inproceedings{62296,
  author       = {{Spieker, Carsten and Förstner, Jens and Hölscher, Jonas and Claes, Leander and Henning, Bernd}},
  booktitle    = {{2025 International Congress on Ultrasonics}},
  pages        = {{126–129}},
  publisher    = {{AMA Service GmbH}},
  title        = {{{Modeling and simulation of the behavior of piezoceramics with the discontinuous Galerkin method}}},
  doi          = {{10.5162/ultrasonic2025/a18-a1}},
  year         = {{2025}},
}

@inproceedings{62297,
  author       = {{Hölscher, Jonas and Friesen, Olga and Claes, Leander and Spieker, Carsten and Förstner, Jens and Henning, Bernd}},
  booktitle    = {{2025 International Congress on Ultrasonics}},
  pages        = {{130–133}},
  publisher    = {{AMA Service GmbH}},
  title        = {{{Multiscale thermo-piezoelectric simulations using the finite element method}}},
  doi          = {{10.5162/ultrasonic2025/a18-a2}},
  year         = {{2025}},
}

@article{63440,
  author       = {{Moritzer, Elmar and Brandes, Philipp and Westphal, Max Siegfried and Claes, Leander and Wippermann, Mareen and Düchting, Julia and Henning, Bernd}},
  journal      = {{WAK Jahresmagazin}},
  keywords     = {{Faser-Kunststoff-Verbunde (FKV), Faserverstärkte Kunststoffe (FVK), Organobleche, Ultraschall}},
  pages        = {{26–29}},
  title        = {{{ZERSTÖRUNGSFREIE ULTRASCHALLPRÜFUNG VON ORGANOBLECHEN}}},
  volume       = {{2025}},
  year         = {{2025}},
}

@inproceedings{62295,
  author       = {{Wippermann, Mareen and Claes, Leander}},
  booktitle    = {{2025 International Congress on Ultrasonics}},
  location     = {{Paderborn}},
  pages        = {{24----27}},
  publisher    = {{AMA Service GmbH}},
  title        = {{{Phononic crystallography of fibre-reinforced polymers using broadband acoustic waves}}},
  doi          = {{10.5162/ultrasonic2025/a1-b2}},
  year         = {{2025}},
}

@inproceedings{62042,
  author       = {{Reckmann, Eileen and Blomberg, Tobias and Temmen, Katrin}},
  booktitle    = {{Entdecken, lehren und forschen im Schülerlabor}},
  editor       = {{van Vorst, Helena}},
  location     = {{Bochum}},
  title        = {{{Neue Wege für das Schülerlabor – Rahmenbedingungen eines mobilen Schülerlabors}}},
  volume       = {{45}},
  year         = {{2025}},
}

@inproceedings{64145,
  author       = {{Newberry, Melissa and Jonas-Ahrend, Gabriela and Rizvi, Meher and van der Want, Anna}},
  location     = {{Glasgow}},
  title        = {{{The Dynamics of Geographic Space when working with International Teacher Educators in Collaborative Research}}},
  year         = {{2025}},
}

@inproceedings{64143,
  author       = {{Guberman, Ainat and Jonas-Ahrend, Gabriela and Arvif-Elyashiv, Rinat and Ben-Yehduah, Gal and Cyprus, Dominik}},
  location     = {{Belgrad}},
  title        = {{{Career Changing STEM Teachers` Motivation over Time: Lessons from Israel and Germany}}},
  year         = {{2025}},
}

@inproceedings{64142,
  author       = {{Ratnam, Tara and Jonas-Ahrend, Gabriela and Newberry, Melissa}},
  location     = {{Denver/CO, USA}},
  title        = {{{The presence of an Invisible College in the knowledge network of ISATT}}},
  year         = {{2025}},
}

@inbook{62188,
  author       = {{Vernholz, Mats and Jonas-Ahrend, Gabriela and Temmen, Katrin}},
  booktitle    = {{Zukünfte technischer Bildung}},
  editor       = {{Wiemer, Tobias and Binder, Martin and Penning, Isabelle}},
  location     = {{Halle/Saale}},
  title        = {{{„Und ich sag mal, Theorie und Praxis ist zweierlei“. Wie können Praxisphasen Lehramtsstudierende auf zukünftige Anforderungen vorbereiten? }}},
  doi          = {{https://doi.org/10.25932/publishup-67926}},
  volume       = {{26}},
  year         = {{2025}},
}

@article{61932,
  abstract     = {{<jats:p>Substantial improvements in the performance of optical interconnects based on multi-mode fibers are required to support emerging single-channel data transmission rates of 200 Gb/s and 400 Gb/s. Future optical components must combine very high modulation bandwidths—supporting signaling at 100 Gbaud and 200 Gbaud—with reduced spectral width to mitigate chromatic-dispersion-induced pulse broadening and increased brightness to further restrict flux-confining area in multi-mode fibers and thereby increase the effective modal bandwidth (EMB). A particularly promising route to improved performance within standard oxide-confined VCSEL technology is the introduction of multiple isolated or optically coupled oxide-confined apertures, which we refer to collectively as multi-aperture (MA) VCSEL arrays. We show that properly designed MA VCSELs exhibit narrow emission spectra, narrow far-field profiles and extended intrinsic modulation bandwidths, enabling longer-reach data transmission over both multi-mode (MMF) and single-mode fibers (SMF). One approach uses optically isolated apertures with lateral dimensions of approximately 2–3 µm arranged with a pitch of 10–12 µm or less. Such devices demonstrate relaxation oscillation frequencies of around 30 GHz in continuous-wave operation and intrinsic modulation bandwidths approaching 50 GHz. Compared with a conventional single-aperture VCSELs of equivalent oxide-confined area, MA designs can reduce the spectral width (root mean square values &lt; 0.15 nm), lower series resistance (≈50 Ω) and limit junction overheating through more efficient multi-spot heat dissipation at the same total current. As each aperture lases in a single transverse mode, these devices exhibit narrow far-field patterns. In combination with well-defined spacing between emitting spots, they permit tailored restricted launch conditions in MMFs, enhancing effective modal bandwidth. In another MA approach, the apertures are optically coupled such that self-injection locking (SIL) leads to lasing in a single supermode. One may regard one of the supermodes as acting as a master mode controlling the other one. Streak-camera studies reveal post-pulse oscillations in the SIL regime at frequencies up to 100 GHz. MA VCSELs enable a favorable combination of wavelength chirp and chromatic dispersion, extending transmission distances over MMFs beyond those expected for zero-chirp sources and supporting transfer bandwidths up to 60 GHz over kilometer-length SMF links.</jats:p>}},
  author       = {{Ledentsov, Nikolay N. and Ledentsov, Nikolay and Shchukin, Vitaly A. and Ledentsov, Alexander N. and Makarov, Oleg Yu. and Titkov, Ilya E. and Lindemann, Markus and de Adelsburg Ettmayer, Thomas and Gerhardt, Nils Christopher and Hofmann, Martin R. and Chen, Xin and Hurley, Jason E. and Dong, Hao and Li, Ming-Jun}},
  issn         = {{2304-6732}},
  journal      = {{Photonics}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers}}},
  doi          = {{10.3390/photonics12101037}},
  volume       = {{12}},
  year         = {{2025}},
}

@article{61931,
  abstract     = {{<jats:p>Recent research revealed that single-mode vertical-cavity surface-emitting lasers under spin injection (spin-VCSELs) have the potential to revolutionize laser technology for short-haul optical communications. While previous studies have focused solely on single-mode operation, this study introduces multimode spin-VCSELs. We experimentally demonstrate the existence of multi-resonant polarization dynamics when spin is injected, a phenomenon previously unobserved. The development opens the door to significantly faster and more efficient optical communication systems by harnessing the collective behavior of multiple laser modes. Furthermore, we lay the groundwork for understanding multimode operation through the extension of the single-mode spin–flip model, which forms the basis for present and future analyses of multimode spin-laser operation. This work is an important step toward realizing the full potential of spin-VCSELs and, thus, enables significantly improved performance of spin-VCSEL-based optical networks in the future.</jats:p>}},
  author       = {{Diiankova, Uliana and Drong, Mariusz and Pusch, Tobias and Michalzik, Rainer and Lindemann, Markus and Gerhardt, Nils Christopher and Hofmann, Martin R.}},
  issn         = {{2378-0967}},
  journal      = {{APL Photonics}},
  number       = {{10}},
  publisher    = {{AIP Publishing}},
  title        = {{{Multimode vertical-cavity surface-emitting lasers under spin injection}}},
  doi          = {{10.1063/5.0286998}},
  volume       = {{10}},
  year         = {{2025}},
}