[{"publication_identifier":{"unknown":["ISBN 978-3-95977-368-3"]},"citation":{"bibtex":"@book{Scheideler_Meeks_2025, place={SAND 2025, Liverpool, UK, June 9-11, 2025. LIPIcs 330, Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title={4th Symposium on Algorithmic Foundations of Dynamic Networks.}, year={2025} }","short":"C. Scheideler, K. Meeks, eds., 4th Symposium on Algorithmic Foundations of Dynamic Networks., SAND 2025, Liverpool, UK, June 9-11, 2025. LIPIcs 330, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2025.","mla":"Scheideler, Christian, and Kitty Meeks, editors. <i>4th Symposium on Algorithmic Foundations of Dynamic Networks.</i> 2025.","apa":"Scheideler, C., &#38; Meeks, K. (Eds.). (2025). <i>4th Symposium on Algorithmic Foundations of Dynamic Networks.</i>","ama":"Scheideler C, Meeks K, eds. <i>4th Symposium on Algorithmic Foundations of Dynamic Networks.</i>; 2025.","ieee":"C. Scheideler and K. Meeks, Eds., <i>4th Symposium on Algorithmic Foundations of Dynamic Networks.</i> SAND 2025, Liverpool, UK, June 9-11, 2025. LIPIcs 330, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2025.","chicago":"Scheideler, Christian, and Kitty Meeks, eds. <i>4th Symposium on Algorithmic Foundations of Dynamic Networks.</i> SAND 2025, Liverpool, UK, June 9-11, 2025. LIPIcs 330, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2025."},"year":"2025","place":"SAND 2025, Liverpool, UK, June 9-11, 2025. LIPIcs 330, Schloss Dagstuhl - Leibniz-Zentrum für Informatik","date_created":"2026-02-10T09:49:03Z","date_updated":"2026-02-11T09:11:09Z","title":"4th Symposium on Algorithmic Foundations of Dynamic Networks.","type":"book_editor","status":"public","editor":[{"first_name":"Christian","last_name":"Scheideler","id":"20792","full_name":"Scheideler, Christian"},{"last_name":"Meeks","full_name":"Meeks, Kitty","first_name":"Kitty"}],"user_id":"15578","department":[{"_id":"34"},{"_id":"7"},{"_id":"79"}],"_id":"64099","language":[{"iso":"eng"}]},{"issue":"80","publication_identifier":{"issn":["1359-7345"]},"page":"15622–15625","intvolume":"        61","citation":{"ieee":"S. Hutsch, S. Grätz, J. Lins, T. Gutmann, and L. Borchardt, “Solid-state polycyclotrimerization of diynes to porous organic polymers,” <i>Chemical Communications</i>, vol. 61, no. 80, pp. 15622–15625, 2025, doi: <a href=\"https://doi.org/10.1039/D5CC04700E\">10.1039/D5CC04700E</a>.","chicago":"Hutsch, Stefanie, Sven Grätz, Jonas Lins, Torsten Gutmann, and Lars Borchardt. “Solid-State Polycyclotrimerization of Diynes to Porous Organic Polymers.” <i>Chemical Communications</i> 61, no. 80 (2025): 15622–15625. <a href=\"https://doi.org/10.1039/D5CC04700E\">https://doi.org/10.1039/D5CC04700E</a>.","ama":"Hutsch S, Grätz S, Lins J, Gutmann T, Borchardt L. Solid-state polycyclotrimerization of diynes to porous organic polymers. <i>Chemical Communications</i>. 2025;61(80):15622–15625. doi:<a href=\"https://doi.org/10.1039/D5CC04700E\">10.1039/D5CC04700E</a>","bibtex":"@article{Hutsch_Grätz_Lins_Gutmann_Borchardt_2025, title={Solid-state polycyclotrimerization of diynes to porous organic polymers}, volume={61}, DOI={<a href=\"https://doi.org/10.1039/D5CC04700E\">10.1039/D5CC04700E</a>}, number={80}, journal={Chemical Communications}, publisher={The Royal Society of Chemistry}, author={Hutsch, Stefanie and Grätz, Sven and Lins, Jonas and Gutmann, Torsten and Borchardt, Lars}, year={2025}, pages={15622–15625} }","mla":"Hutsch, Stefanie, et al. “Solid-State Polycyclotrimerization of Diynes to Porous Organic Polymers.” <i>Chemical Communications</i>, vol. 61, no. 80, The Royal Society of Chemistry, 2025, pp. 15622–15625, doi:<a href=\"https://doi.org/10.1039/D5CC04700E\">10.1039/D5CC04700E</a>.","short":"S. Hutsch, S. Grätz, J. Lins, T. Gutmann, L. Borchardt, Chemical Communications 61 (2025) 15622–15625.","apa":"Hutsch, S., Grätz, S., Lins, J., Gutmann, T., &#38; Borchardt, L. (2025). Solid-state polycyclotrimerization of diynes to porous organic polymers. <i>Chemical Communications</i>, <i>61</i>(80), 15622–15625. <a href=\"https://doi.org/10.1039/D5CC04700E\">https://doi.org/10.1039/D5CC04700E</a>"},"year":"2025","volume":61,"author":[{"last_name":"Hutsch","full_name":"Hutsch, Stefanie","first_name":"Stefanie"},{"full_name":"Grätz, Sven","last_name":"Grätz","first_name":"Sven"},{"full_name":"Lins, Jonas","last_name":"Lins","first_name":"Jonas"},{"first_name":"Torsten","last_name":"Gutmann","id":"118165","full_name":"Gutmann, Torsten"},{"full_name":"Borchardt, Lars","last_name":"Borchardt","first_name":"Lars"}],"date_created":"2026-02-07T15:47:03Z","date_updated":"2026-02-17T16:16:36Z","publisher":"The Royal Society of Chemistry","doi":"10.1039/D5CC04700E","title":"Solid-state polycyclotrimerization of diynes to porous organic polymers","publication":"Chemical Communications","type":"journal_article","status":"public","abstract":[{"lang":"eng","text":"Herein, we report a solid-state polycyclotrimerization of 1,4-diethynylbenzene using mechanochemical activation in a ball mill, yielding a highly porous and hydrophobic hyperbranched polymer (HBP) with a specific surface area of up to 570 m2 g−1. The reaction, catalyzed by Fe(hmds)2 and conducted under solvent-free conditions, was optimized by varying milling time and frequency. This method enables the efficient synthesis of insoluble, porous organic polymers with high yields (up to 95%) and offers an environmentally friendly alternative to traditional solution-based polymerizations."}],"user_id":"100715","_id":"63990","extern":"1","language":[{"iso":"eng"}]},{"publication":"Journal of Chemical & Engineering Data","type":"journal_article","abstract":[{"text":"The thermal behavior of n-octanol and related ether alcohols has been studied by differential scanning calorimetry (DSC). The melting point, heat of fusion, and isobaric heat capacities of n-octanol obtained from the DSC measurements are in good agreement with literature values. The ether alcohols display kinetic barriers for forming a solid phase during cooldown. These barriers are least for 6-methoxyhexanol that forms a solid upon cooling except for the highest measured temperature change rate of 40 K·min–1, followed by 4-propoxybutanol that forms a solid during cooldown only at low cooling rates. 2-Pentoxyethanol and 5-ethoxypentanol form a solid during the heating cycle that then melts again upon further heating. 3-Butoxypropanol does not display any exo- and endothermic features for all measured temperature change rates. Consequently, new data on melting point and heats of fusion are reported for the ether alcohols except for 3-butoxypropanol. New isobaric heat capacities are presented as well for the liquid phase of these ether alcohols. The thermal behavior of n-octanol and related ether alcohols has been studied by differential scanning calorimetry (DSC). The melting point, heat of fusion, and isobaric heat capacities of n-octanol obtained from the DSC measurements are in good agreement with literature values. The ether alcohols display kinetic barriers for forming a solid phase during cooldown. These barriers are least for 6-methoxyhexanol that forms a solid upon cooling except for the highest measured temperature change rate of 40 K·min–1, followed by 4-propoxybutanol that forms a solid during cooldown only at low cooling rates. 2-Pentoxyethanol and 5-ethoxypentanol form a solid during the heating cycle that then melts again upon further heating. 3-Butoxypropanol does not display any exo- and endothermic features for all measured temperature change rates. Consequently, new data on melting point and heats of fusion are reported for the ether alcohols except for 3-butoxypropanol. New isobaric heat capacities are presented as well for the liquid phase of these ether alcohols.","lang":"eng"}],"status":"public","_id":"63981","user_id":"100715","language":[{"iso":"eng"}],"extern":"1","publication_identifier":{"issn":["0021-9568"]},"issue":"1","year":"2025","page":"600–606","intvolume":"        70","citation":{"apa":"Hoffmann, M. M., Gutmann, T., &#38; Buntkowsky, G. (2025). Thermal Behavior of n-Octanol and Related Ether Alcohols. <i>Journal of Chemical &#38; Engineering Data</i>, <i>70</i>(1), 600–606. <a href=\"https://doi.org/10.1021/acs.jced.4c00525\">https://doi.org/10.1021/acs.jced.4c00525</a>","short":"M.M. Hoffmann, T. Gutmann, G. Buntkowsky, Journal of Chemical &#38; Engineering Data 70 (2025) 600–606.","bibtex":"@article{Hoffmann_Gutmann_Buntkowsky_2025, title={Thermal Behavior of n-Octanol and Related Ether Alcohols}, volume={70}, DOI={<a href=\"https://doi.org/10.1021/acs.jced.4c00525\">10.1021/acs.jced.4c00525</a>}, number={1}, journal={Journal of Chemical &#38; Engineering Data}, publisher={American Chemical Society}, author={Hoffmann, Markus M. and Gutmann, Torsten and Buntkowsky, Gerd}, year={2025}, pages={600–606} }","mla":"Hoffmann, Markus M., et al. “Thermal Behavior of N-Octanol and Related Ether Alcohols.” <i>Journal of Chemical &#38; Engineering Data</i>, vol. 70, no. 1, American Chemical Society, 2025, pp. 600–606, doi:<a href=\"https://doi.org/10.1021/acs.jced.4c00525\">10.1021/acs.jced.4c00525</a>.","chicago":"Hoffmann, Markus M., Torsten Gutmann, and Gerd Buntkowsky. “Thermal Behavior of N-Octanol and Related Ether Alcohols.” <i>Journal of Chemical &#38; Engineering Data</i> 70, no. 1 (2025): 600–606. <a href=\"https://doi.org/10.1021/acs.jced.4c00525\">https://doi.org/10.1021/acs.jced.4c00525</a>.","ieee":"M. M. Hoffmann, T. Gutmann, and G. Buntkowsky, “Thermal Behavior of n-Octanol and Related Ether Alcohols,” <i>Journal of Chemical &#38; Engineering Data</i>, vol. 70, no. 1, pp. 600–606, 2025, doi: <a href=\"https://doi.org/10.1021/acs.jced.4c00525\">10.1021/acs.jced.4c00525</a>.","ama":"Hoffmann MM, Gutmann T, Buntkowsky G. Thermal Behavior of n-Octanol and Related Ether Alcohols. <i>Journal of Chemical &#38; Engineering Data</i>. 2025;70(1):600–606. doi:<a href=\"https://doi.org/10.1021/acs.jced.4c00525\">10.1021/acs.jced.4c00525</a>"},"date_updated":"2026-02-17T16:16:57Z","publisher":"American Chemical Society","volume":70,"author":[{"first_name":"Markus M.","full_name":"Hoffmann, Markus M.","last_name":"Hoffmann"},{"first_name":"Torsten","last_name":"Gutmann","full_name":"Gutmann, Torsten","id":"118165"},{"full_name":"Buntkowsky, Gerd","last_name":"Buntkowsky","first_name":"Gerd"}],"date_created":"2026-02-07T15:44:13Z","title":"Thermal Behavior of n-Octanol and Related Ether Alcohols","doi":"10.1021/acs.jced.4c00525"},{"title":"Blow-up exponents and a semilinear elliptic equation for the fractional Laplacian on hyperbolic spaces","date_created":"2026-02-19T11:42:22Z","author":[{"first_name":"Tommaso","full_name":"Bruno, Tommaso","last_name":"Bruno"},{"full_name":"Papageorgiou, Effie","last_name":"Papageorgiou","first_name":"Effie"}],"date_updated":"2026-02-19T11:43:16Z","citation":{"ama":"Bruno T, Papageorgiou E. Blow-up exponents and a semilinear elliptic equation for the fractional Laplacian on hyperbolic spaces. <i>arXiv:250912349</i>. Published online 2025.","apa":"Bruno, T., &#38; Papageorgiou, E. (2025). Blow-up exponents and a semilinear elliptic equation for the fractional Laplacian on hyperbolic spaces. In <i>arXiv:2509.12349</i>.","bibtex":"@article{Bruno_Papageorgiou_2025, title={Blow-up exponents and a semilinear elliptic equation for the fractional Laplacian on hyperbolic spaces}, journal={arXiv:2509.12349}, author={Bruno, Tommaso and Papageorgiou, Effie}, year={2025} }","short":"T. Bruno, E. Papageorgiou, ArXiv:2509.12349 (2025).","mla":"Bruno, Tommaso, and Effie Papageorgiou. “Blow-up Exponents and a Semilinear Elliptic Equation for the Fractional Laplacian on Hyperbolic Spaces.” <i>ArXiv:2509.12349</i>, 2025.","ieee":"T. Bruno and E. Papageorgiou, “Blow-up exponents and a semilinear elliptic equation for the fractional Laplacian on hyperbolic spaces,” <i>arXiv:2509.12349</i>. 2025.","chicago":"Bruno, Tommaso, and Effie Papageorgiou. “Blow-up Exponents and a Semilinear Elliptic Equation for the Fractional Laplacian on Hyperbolic Spaces.” <i>ArXiv:2509.12349</i>, 2025."},"year":"2025","language":[{"iso":"eng"}],"user_id":"100325","_id":"64267","external_id":{"arxiv":["2509.12349"]},"project":[{"name":"TRR 358: Ganzzahlige Strukturen in Geometrie und Darstellungstheorie","_id":"357"}],"status":"public","abstract":[{"text":"Let $\\mathbb{H}^n$ be the $n$-dimensional real hyperbolic space, $Δ$ its nonnegative Laplace--Beltrami operator whose bottom of the spectrum we denote by $λ_{0}$, and $σ\\in (0,1)$.\r\n  The aim of this paper is twofold. On the one hand, we determine the Fujita exponent for the fractional heat equation \\[\\partial_{t} u + Δ^σu = e^{βt}|u|^{γ-1}u,\\] by proving that nontrivial positive global solutions exist if and only if $γ\\geq 1 + β/ λ_{0}^σ$. On the other hand, we prove the existence of non-negative, bounded and finite energy solutions of the semilinear fractional elliptic equation \\[\r\n  Δ^σ v - λ^σ v - v^γ=0 \\] for $0\\leq λ\\leq λ_{0}$ and $1<γ< \\frac{n+2σ}{n-2σ}$. The two problems are known to be connected and the latter, aside from its independent interest, is actually instrumental to the former.\r\n  \\smallskip\r\n  At the core of our results stands a novel fractional Poincaré-type inequality expressed in terms of a new scale of $L^{2}$ fractional Sobolev spaces, which sharpens those known so far, and which holds more generally on Riemannian symmetric spaces of non-compact type. We also establish an associated Rellich--Kondrachov-like compact embedding theorem for radial functions, along with other related properties.","lang":"eng"}],"publication":"arXiv:2509.12349","type":"preprint"},{"intvolume":"        12","citation":{"apa":"Ledentsov, N. N., Ledentsov, N., Shchukin, V. A., Ledentsov, A. N., Makarov, O. Yu., Titkov, I. E., Lindemann, M., de Adelsburg Ettmayer, T., Gerhardt, N. C., Hofmann, M. R., Chen, X., Hurley, J. E., Dong, H., &#38; Li, M.-J. (2025). VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers. <i>Photonics</i>, <i>12</i>(10), Article 1037. <a href=\"https://doi.org/10.3390/photonics12101037\">https://doi.org/10.3390/photonics12101037</a>","mla":"Ledentsov, Nikolay N., et al. “VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers.” <i>Photonics</i>, vol. 12, no. 10, 1037, MDPI AG, 2025, doi:<a href=\"https://doi.org/10.3390/photonics12101037\">10.3390/photonics12101037</a>.","bibtex":"@article{Ledentsov_Ledentsov_Shchukin_Ledentsov_Makarov_Titkov_Lindemann_de Adelsburg Ettmayer_Gerhardt_Hofmann_et al._2025, title={VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers}, volume={12}, DOI={<a href=\"https://doi.org/10.3390/photonics12101037\">10.3390/photonics12101037</a>}, number={101037}, journal={Photonics}, publisher={MDPI AG}, 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 et al.}, year={2025} }","short":"N.N. Ledentsov, N. Ledentsov, V.A. Shchukin, A.N. Ledentsov, O.Yu. Makarov, I.E. Titkov, M. Lindemann, T. de Adelsburg Ettmayer, N.C. Gerhardt, M.R. Hofmann, X. Chen, J.E. Hurley, H. Dong, M.-J. Li, Photonics 12 (2025).","ama":"Ledentsov NN, Ledentsov N, Shchukin VA, et al. VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers. <i>Photonics</i>. 2025;12(10). doi:<a href=\"https://doi.org/10.3390/photonics12101037\">10.3390/photonics12101037</a>","chicago":"Ledentsov, Nikolay N., Nikolay Ledentsov, Vitaly A. Shchukin, Alexander N. Ledentsov, Oleg Yu. Makarov, Ilya E. Titkov, Markus Lindemann, et al. “VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers.” <i>Photonics</i> 12, no. 10 (2025). <a href=\"https://doi.org/10.3390/photonics12101037\">https://doi.org/10.3390/photonics12101037</a>.","ieee":"N. N. Ledentsov <i>et al.</i>, “VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers,” <i>Photonics</i>, vol. 12, no. 10, Art. no. 1037, 2025, doi: <a href=\"https://doi.org/10.3390/photonics12101037\">10.3390/photonics12101037</a>."},"publication_identifier":{"issn":["2304-6732"]},"publication_status":"published","doi":"10.3390/photonics12101037","volume":12,"author":[{"full_name":"Ledentsov, Nikolay N.","last_name":"Ledentsov","first_name":"Nikolay N."},{"first_name":"Nikolay","full_name":"Ledentsov, Nikolay","last_name":"Ledentsov"},{"first_name":"Vitaly A.","full_name":"Shchukin, Vitaly A.","last_name":"Shchukin"},{"first_name":"Alexander N.","last_name":"Ledentsov","full_name":"Ledentsov, Alexander N."},{"last_name":"Makarov","full_name":"Makarov, Oleg Yu.","first_name":"Oleg Yu."},{"first_name":"Ilya E.","last_name":"Titkov","full_name":"Titkov, Ilya E."},{"first_name":"Markus","last_name":"Lindemann","full_name":"Lindemann, Markus"},{"first_name":"Thomas","full_name":"de Adelsburg Ettmayer, Thomas","last_name":"de Adelsburg Ettmayer"},{"first_name":"Nils Christopher","orcid":"0009-0002-5538-231X","last_name":"Gerhardt","full_name":"Gerhardt, Nils Christopher","id":"115298"},{"last_name":"Hofmann","full_name":"Hofmann, Martin R.","first_name":"Martin R."},{"full_name":"Chen, Xin","last_name":"Chen","first_name":"Xin"},{"last_name":"Hurley","full_name":"Hurley, Jason E.","first_name":"Jason E."},{"first_name":"Hao","last_name":"Dong","full_name":"Dong, Hao"},{"first_name":"Ming-Jun","last_name":"Li","full_name":"Li, Ming-Jun"}],"date_updated":"2026-02-19T12:39:12Z","status":"public","type":"journal_article","article_number":"1037","department":[{"_id":"977"}],"user_id":"15911","_id":"61932","year":"2025","issue":"10","title":"VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers","date_created":"2025-10-23T10:59:59Z","publisher":"MDPI AG","abstract":[{"text":"<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>","lang":"eng"}],"publication":"Photonics","language":[{"iso":"eng"}]},{"file":[{"access_level":"closed","file_name":"MSA_hermitsch_published.pdf","file_id":"64288","file_size":443262,"date_created":"2026-02-19T14:14:39Z","creator":"llangen","date_updated":"2026-02-19T14:14:39Z","relation":"main_file","success":1,"content_type":"application/pdf"}],"abstract":[{"text":"We establish a multiresolution analysis on the space $\\text{Herm}(n)$ of\r\n$n\\times n$ complex Hermitian matrices which is adapted to invariance under\r\nconjugation by the unitary group $U(n).$ The orbits under this action are\r\nparametrized by the possible ordered spectra of Hermitian matrices, which\r\nconstitute a closed Weyl chamber of type $A_{n-1}$ in $\\mathbb R^n.$ The space\r\n$L^2(\\text{Herm}(n))^{U(n)}$ of radial, i.e. $U(n)$-invariant $L^2$-functions\r\non $\\text{Herm}(n)$ is naturally identified with a certain weighted $L^2$-space\r\non this chamber.\r\n  The scale spaces of our multiresolution analysis are obtained by usual dyadic\r\ndilations as well as generalized translations of a scaling function, where the\r\ngeneralized translation is a hypergroup translation which respects the radial\r\ngeometry. We provide a concise criterion to characterize orthonormal wavelet\r\nbases and show that such bases always exist. They provide natural orthonormal\r\nbases of the space $L^2(\\text{Herm}(n))^{U(n)}.$\r\n  Furthermore, we show how to obtain radial scaling functions from classical\r\nscaling functions on $\\mathbb R^{n}$. Finally, generalizations related to the\r\nCartan decompositions for general compact Lie groups are indicated.","lang":"eng"}],"publication":"Indagationes Mathematicae","language":[{"iso":"eng"}],"ddc":["510"],"external_id":{"arxiv":["2410.10364"]},"year":"2025","issue":"6","title":"Multiresolution analysis on spectra of hermitian matrices","date_created":"2024-10-22T09:31:19Z","publisher":"Elsevier","status":"public","type":"journal_article","file_date_updated":"2026-02-19T14:14:39Z","article_type":"original","department":[{"_id":"555"}],"user_id":"73664","_id":"56717","project":[{"name":"TRR 358 - Ganzzahlige Strukturen in Geometrie und Darstellungstheorie","_id":"357"}],"intvolume":"        36","page":"1671-1694","citation":{"ieee":"L. Langen and M. Rösler, “Multiresolution analysis on spectra of hermitian matrices,” <i>Indagationes Mathematicae</i>, vol. 36, no. 6, pp. 1671–1694, 2025.","chicago":"Langen, Lukas, and Margit Rösler. “Multiresolution Analysis on Spectra of Hermitian Matrices.” <i>Indagationes Mathematicae</i> 36, no. 6 (2025): 1671–94.","ama":"Langen L, Rösler M. Multiresolution analysis on spectra of hermitian matrices. <i>Indagationes Mathematicae</i>. 2025;36(6):1671-1694.","apa":"Langen, L., &#38; Rösler, M. (2025). Multiresolution analysis on spectra of hermitian matrices. <i>Indagationes Mathematicae</i>, <i>36</i>(6), 1671–1694.","bibtex":"@article{Langen_Rösler_2025, title={Multiresolution analysis on spectra of hermitian matrices}, volume={36}, number={6}, journal={Indagationes Mathematicae}, publisher={Elsevier}, author={Langen, Lukas and Rösler, Margit}, year={2025}, pages={1671–1694} }","mla":"Langen, Lukas, and Margit Rösler. “Multiresolution Analysis on Spectra of Hermitian Matrices.” <i>Indagationes Mathematicae</i>, vol. 36, no. 6, Elsevier, 2025, pp. 1671–94.","short":"L. Langen, M. Rösler, Indagationes Mathematicae 36 (2025) 1671–1694."},"related_material":{"link":[{"relation":"research_paper","url":"https://arxiv.org/abs/2410.10364"}]},"has_accepted_license":"1","publication_status":"published","main_file_link":[{"url":"https://doi.org/10.1016/j.indag.2025.03.009"}],"volume":36,"author":[{"full_name":"Langen, Lukas","id":"73664","last_name":"Langen","first_name":"Lukas"},{"full_name":"Rösler, Margit","id":"37390","last_name":"Rösler","first_name":"Margit"}],"date_updated":"2026-02-19T14:16:43Z"},{"type":"preprint","publication_status":"submitted","status":"public","citation":{"chicago":"Bernstein, Joseph, Pritam Ganguly, Bernhard Krötz, Job Kuit, and Eitan Sayag. “On Norms on Harish-Chandra Modules,” n.d.","ieee":"J. Bernstein, P. Ganguly, B. Krötz, J. Kuit, and E. Sayag, “On norms on Harish-Chandra modules.” .","ama":"Bernstein J, Ganguly P, Krötz B, Kuit J, Sayag E. On norms on Harish-Chandra modules.","mla":"Bernstein, Joseph, et al. <i>On Norms on Harish-Chandra Modules</i>.","bibtex":"@article{Bernstein_Ganguly_Krötz_Kuit_Sayag, title={On norms on Harish-Chandra modules}, author={Bernstein, Joseph and Ganguly, Pritam and Krötz, Bernhard and Kuit, Job and Sayag, Eitan} }","short":"J. Bernstein, P. Ganguly, B. Krötz, J. Kuit, E. Sayag, (n.d.).","apa":"Bernstein, J., Ganguly, P., Krötz, B., Kuit, J., &#38; Sayag, E. (n.d.). <i>On norms on Harish-Chandra modules</i>."},"abstract":[{"lang":"eng","text":"The Casselman-Wallach theorem is a foundational result in the theory of representations of real reductive groups connecting algebraic representations to topological representations. We provide a quantitative version of this theorem. For that we introduce the notion of {\\it Sobolev gap} for a Harish-Chandra module. This is a new invariant whose finiteness is highly non-trivial. We determine the Sobolev gap for representations in the unitary dual of the group $\\SL(2,\\R)$ and establish uniform finiteness results in general for representations of the discrete series and the minimal principal series. We use these notions to reformulate and extend classical results of Bernstein and Reznikov concerning automorphic functionals with respect to cocompact lattices. In particular, we prove an abstract convexity bound which applies to automorphic functionals with respect to general lattices in $\\SL(2,\\R)$ and is independent of the type of unitarizable irreducible Harish-Chandra module. Finally, we offer an extensive list of open problems."}],"year":"2025","date_created":"2026-02-19T13:48:26Z","author":[{"first_name":"Joseph","last_name":"Bernstein","full_name":"Bernstein, Joseph"},{"full_name":"Ganguly, Pritam","last_name":"Ganguly","first_name":"Pritam"},{"first_name":"Bernhard","last_name":"Krötz","full_name":"Krötz, Bernhard"},{"first_name":"Job","last_name":"Kuit","full_name":"Kuit, Job"},{"full_name":"Sayag, Eitan","last_name":"Sayag","first_name":"Eitan"}],"user_id":"52730","_id":"64287","date_updated":"2026-02-19T13:49:37Z","language":[{"iso":"eng"}],"title":"On norms on Harish-Chandra modules"},{"year":"2025","citation":{"short":"B. Janssens, M. Niestijl, Communications in Mathematical Physics 406 (2025).","mla":"Janssens, Bas, and Milan Niestijl. “Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms.” <i>Communications in Mathematical Physics</i>, vol. 406, no. 2, 45, Springer Science and Business Media LLC, 2025, doi:<a href=\"https://doi.org/10.1007/s00220-024-05226-w\">10.1007/s00220-024-05226-w</a>.","bibtex":"@article{Janssens_Niestijl_2025, title={Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms}, volume={406}, DOI={<a href=\"https://doi.org/10.1007/s00220-024-05226-w\">10.1007/s00220-024-05226-w</a>}, number={245}, journal={Communications in Mathematical Physics}, publisher={Springer Science and Business Media LLC}, author={Janssens, Bas and Niestijl, Milan}, year={2025} }","apa":"Janssens, B., &#38; Niestijl, M. (2025). Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms. <i>Communications in Mathematical Physics</i>, <i>406</i>(2), Article 45. <a href=\"https://doi.org/10.1007/s00220-024-05226-w\">https://doi.org/10.1007/s00220-024-05226-w</a>","ama":"Janssens B, Niestijl M. Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms. <i>Communications in Mathematical Physics</i>. 2025;406(2). doi:<a href=\"https://doi.org/10.1007/s00220-024-05226-w\">10.1007/s00220-024-05226-w</a>","chicago":"Janssens, Bas, and Milan Niestijl. “Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms.” <i>Communications in Mathematical Physics</i> 406, no. 2 (2025). <a href=\"https://doi.org/10.1007/s00220-024-05226-w\">https://doi.org/10.1007/s00220-024-05226-w</a>.","ieee":"B. Janssens and M. Niestijl, “Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms,” <i>Communications in Mathematical Physics</i>, vol. 406, no. 2, Art. no. 45, 2025, doi: <a href=\"https://doi.org/10.1007/s00220-024-05226-w\">10.1007/s00220-024-05226-w</a>."},"intvolume":"       406","publication_status":"published","publication_identifier":{"issn":["0010-3616","1432-0916"]},"issue":"2","title":"Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms","doi":"10.1007/s00220-024-05226-w","publisher":"Springer Science and Business Media LLC","date_updated":"2026-02-20T09:41:41Z","author":[{"full_name":"Janssens, Bas","last_name":"Janssens","first_name":"Bas"},{"first_name":"Milan","last_name":"Niestijl","full_name":"Niestijl, Milan"}],"date_created":"2026-02-20T09:33:11Z","volume":406,"abstract":[{"text":"<jats:title>Abstract</jats:title>\r\n          <jats:p>Motivated by asymptotic symmetry groups in general relativity, we consider projective unitary representations <jats:inline-formula>\r\n              <jats:alternatives>\r\n                <jats:tex-math>$$\\overline{\\rho }$$</jats:tex-math>\r\n                <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n                  <mml:mover>\r\n                    <mml:mi>ρ</mml:mi>\r\n                    <mml:mo>¯</mml:mo>\r\n                  </mml:mover>\r\n                </mml:math>\r\n              </jats:alternatives>\r\n            </jats:inline-formula> of the Lie group <jats:inline-formula>\r\n              <jats:alternatives>\r\n                <jats:tex-math>$${{\\,\\textrm{Diff}\\,}}_c(M)$$</jats:tex-math>\r\n                <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n                  <mml:mrow>\r\n                    <mml:msub>\r\n                      <mml:mrow>\r\n                        <mml:mspace/>\r\n                        <mml:mtext>Diff</mml:mtext>\r\n                        <mml:mspace/>\r\n                      </mml:mrow>\r\n                      <mml:mi>c</mml:mi>\r\n                    </mml:msub>\r\n                    <mml:mrow>\r\n                      <mml:mo>(</mml:mo>\r\n                      <mml:mi>M</mml:mi>\r\n                      <mml:mo>)</mml:mo>\r\n                    </mml:mrow>\r\n                  </mml:mrow>\r\n                </mml:math>\r\n              </jats:alternatives>\r\n            </jats:inline-formula> of compactly supported diffeomorphisms of a smooth manifold <jats:italic>M</jats:italic> that satisfy a so-called generalized positive energy condition. In particular, this captures representations that are in a suitable sense compatible with a KMS state on the von Neumann algebra generated by <jats:inline-formula>\r\n              <jats:alternatives>\r\n                <jats:tex-math>$$\\overline{\\rho }$$</jats:tex-math>\r\n                <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n                  <mml:mover>\r\n                    <mml:mi>ρ</mml:mi>\r\n                    <mml:mo>¯</mml:mo>\r\n                  </mml:mover>\r\n                </mml:math>\r\n              </jats:alternatives>\r\n            </jats:inline-formula>. We show that if <jats:italic>M</jats:italic> is connected and <jats:inline-formula>\r\n              <jats:alternatives>\r\n                <jats:tex-math>$$\\dim (M) &gt; 1$$</jats:tex-math>\r\n                <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n                  <mml:mrow>\r\n                    <mml:mo>dim</mml:mo>\r\n                    <mml:mo>(</mml:mo>\r\n                    <mml:mi>M</mml:mi>\r\n                    <mml:mo>)</mml:mo>\r\n                    <mml:mo>&gt;</mml:mo>\r\n                    <mml:mn>1</mml:mn>\r\n                  </mml:mrow>\r\n                </mml:math>\r\n              </jats:alternatives>\r\n            </jats:inline-formula>, then any such representation is necessarily trivial on the identity component <jats:inline-formula>\r\n              <jats:alternatives>\r\n                <jats:tex-math>$${{\\,\\textrm{Diff}\\,}}_c(M)_0$$</jats:tex-math>\r\n                <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n                  <mml:mrow>\r\n                    <mml:msub>\r\n                      <mml:mrow>\r\n                        <mml:mspace/>\r\n                        <mml:mtext>Diff</mml:mtext>\r\n                        <mml:mspace/>\r\n                      </mml:mrow>\r\n                      <mml:mi>c</mml:mi>\r\n                    </mml:msub>\r\n                    <mml:msub>\r\n                      <mml:mrow>\r\n                        <mml:mo>(</mml:mo>\r\n                        <mml:mi>M</mml:mi>\r\n                        <mml:mo>)</mml:mo>\r\n                      </mml:mrow>\r\n                      <mml:mn>0</mml:mn>\r\n                    </mml:msub>\r\n                  </mml:mrow>\r\n                </mml:math>\r\n              </jats:alternatives>\r\n            </jats:inline-formula>. As an intermediate step towards this result, we determine the continuous second Lie algebra cohomology <jats:inline-formula>\r\n              <jats:alternatives>\r\n                <jats:tex-math>$$H^2_\\textrm{ct}(\\mathcal {X}_c(M), \\mathbb {R})$$</jats:tex-math>\r\n                <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n                  <mml:mrow>\r\n                    <mml:msubsup>\r\n                      <mml:mi>H</mml:mi>\r\n                      <mml:mtext>ct</mml:mtext>\r\n                      <mml:mn>2</mml:mn>\r\n                    </mml:msubsup>\r\n                    <mml:mrow>\r\n                      <mml:mo>(</mml:mo>\r\n                      <mml:msub>\r\n                        <mml:mi>X</mml:mi>\r\n                        <mml:mi>c</mml:mi>\r\n                      </mml:msub>\r\n                      <mml:mrow>\r\n                        <mml:mo>(</mml:mo>\r\n                        <mml:mi>M</mml:mi>\r\n                        <mml:mo>)</mml:mo>\r\n                      </mml:mrow>\r\n                      <mml:mo>,</mml:mo>\r\n                      <mml:mi>R</mml:mi>\r\n                      <mml:mo>)</mml:mo>\r\n                    </mml:mrow>\r\n                  </mml:mrow>\r\n                </mml:math>\r\n              </jats:alternatives>\r\n            </jats:inline-formula> of the Lie algebra of compactly supported vector fields. This is subtly different from Gelfand–Fuks cohomology in view of the compact support condition.</jats:p>","lang":"eng"}],"status":"public","type":"journal_article","publication":"Communications in Mathematical Physics","article_number":"45","language":[{"iso":"eng"}],"_id":"64289","user_id":"104095","department":[{"_id":"93"}]},{"title":"<i>χ</i>-colorable graph states: closed-form expressions and quantum orthogonal arrays","publisher":"IOP Publishing","date_created":"2026-02-23T13:32:33Z","year":"2025","issue":"35","ddc":["000"],"language":[{"iso":"eng"}],"abstract":[{"lang":"eng","text":"<jats:title>Abstract</jats:title>\r\n               <jats:p>Graph states are a fundamental class of multipartite entangled quantum states with wide-ranging applications in quantum information and computation. In this work, we develop a systematic approach for constructing and analyzing <jats:italic>χ</jats:italic>-colorable graph states, deriving explicit closed-form expressions for arbitrary <jats:italic>χ</jats:italic>. For a broad family of two- and three-colorable graph states, the representations obtained using only local operations require a minimal number of terms in the <jats:italic>Z</jats:italic>-eigenbasis. We prove that every two-colorable graph state is local Clifford (LC) equivalent to a state expressible as a summation of rows of an orthogonal array (OA). For graph states with <jats:italic>χ</jats:italic> &gt; 2, we show that they are LC-equivalent to quantum OAs, establishing a direct combinatorial connection between multipartite entanglement and structured quantum states. Furthermore, the upper and lower bounds of the Schmidt measure for graph states with arbitrary <jats:italic>χ</jats:italic> colorability are discussed, extending the results for an arbitrary local dimension. Our results offer an efficient and practical method for systematically constructing graph states, optimizing their representation in quantum circuits, and identifying structured forms of multipartite entanglement. This approach also connects graph states to <jats:italic>k</jats:italic>-uniform and absolutely maximally entangled states, motivating further exploration of the structure of entangled states and their applications in quantum networks, quantum error correction, and measurement based quantum computing.</jats:p>"}],"file":[{"date_updated":"2026-02-23T13:33:12Z","date_created":"2026-02-23T13:33:12Z","creator":"zraissi","file_size":749401,"file_id":"64592","file_name":"Revis_2025_J._Phys._A%3A_Math._Theor._58_355301.pdf","access_level":"closed","content_type":"application/pdf","success":1,"relation":"main_file"}],"publication":"Journal of Physics A: Mathematical and Theoretical","doi":"10.1088/1751-8121/adfe45","date_updated":"2026-02-23T13:33:28Z","author":[{"first_name":"Konstantinos-Rafail","last_name":"Revis","full_name":"Revis, Konstantinos-Rafail"},{"full_name":"Zakaryan, Hrachya","last_name":"Zakaryan","first_name":"Hrachya"},{"last_name":"Raissi","full_name":"Raissi, Zahra","first_name":"Zahra"}],"volume":58,"citation":{"short":"K.-R. Revis, H. Zakaryan, Z. Raissi, Journal of Physics A: Mathematical and Theoretical 58 (2025).","bibtex":"@article{Revis_Zakaryan_Raissi_2025, title={<i>χ</i>-colorable graph states: closed-form expressions and quantum orthogonal arrays}, volume={58}, DOI={<a href=\"https://doi.org/10.1088/1751-8121/adfe45\">10.1088/1751-8121/adfe45</a>}, number={35355301}, journal={Journal of Physics A: Mathematical and Theoretical}, publisher={IOP Publishing}, author={Revis, Konstantinos-Rafail and Zakaryan, Hrachya and Raissi, Zahra}, year={2025} }","mla":"Revis, Konstantinos-Rafail, et al. “<i>χ</i>-Colorable Graph States: Closed-Form Expressions and Quantum Orthogonal Arrays.” <i>Journal of Physics A: Mathematical and Theoretical</i>, vol. 58, no. 35, 355301, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.1088/1751-8121/adfe45\">10.1088/1751-8121/adfe45</a>.","apa":"Revis, K.-R., Zakaryan, H., &#38; Raissi, Z. (2025). <i>χ</i>-colorable graph states: closed-form expressions and quantum orthogonal arrays. <i>Journal of Physics A: Mathematical and Theoretical</i>, <i>58</i>(35), Article 355301. <a href=\"https://doi.org/10.1088/1751-8121/adfe45\">https://doi.org/10.1088/1751-8121/adfe45</a>","ieee":"K.-R. Revis, H. Zakaryan, and Z. Raissi, “<i>χ</i>-colorable graph states: closed-form expressions and quantum orthogonal arrays,” <i>Journal of Physics A: Mathematical and Theoretical</i>, vol. 58, no. 35, Art. no. 355301, 2025, doi: <a href=\"https://doi.org/10.1088/1751-8121/adfe45\">10.1088/1751-8121/adfe45</a>.","chicago":"Revis, Konstantinos-Rafail, Hrachya Zakaryan, and Zahra Raissi. “<i>χ</i>-Colorable Graph States: Closed-Form Expressions and Quantum Orthogonal Arrays.” <i>Journal of Physics A: Mathematical and Theoretical</i> 58, no. 35 (2025). <a href=\"https://doi.org/10.1088/1751-8121/adfe45\">https://doi.org/10.1088/1751-8121/adfe45</a>.","ama":"Revis K-R, Zakaryan H, Raissi Z. <i>χ</i>-colorable graph states: closed-form expressions and quantum orthogonal arrays. <i>Journal of Physics A: Mathematical and Theoretical</i>. 2025;58(35). doi:<a href=\"https://doi.org/10.1088/1751-8121/adfe45\">10.1088/1751-8121/adfe45</a>"},"intvolume":"        58","publication_status":"published","has_accepted_license":"1","publication_identifier":{"issn":["1751-8113","1751-8121"]},"article_number":"355301","file_date_updated":"2026-02-23T13:33:12Z","_id":"64591","user_id":"98836","status":"public","type":"journal_article"},{"status":"public","abstract":[{"lang":"eng","text":"The versatile self-pierce riveting (V-SPR) is a further development of semi-tubular self-pierce riveting. V-SPR enables adaptation to changing boundary conditions, such as a change in the material thickness combination, without varying the rivet die combination due to increased punch actuation and the use of multi-range capable rivets [1]. The inner punch first sets the rivet. The outer punch then forms the rivet head to the respective sheet thickness. For this, the rivet requires a hard shank and a ductile rivet head, which is achieved by an inductive local hardening process [2]. Until now, the joint formation of rivets with graded hardness profile has been challenging to estimate in the FEM simulation due to the inhomogeneous material conditions in the rivet. In this study, a method capable of reproducing the experimentally determined hardness levels of rivets in detail is shown. This FE model enables the realistic modelling of the mechanical properties of the rivet on the basis of the hardness profile in order to predict the correct deformation processes and stresses during the riveting process. First, the detailed experimental hardness mapping of the locally heat-treated rivets is transferred into the FE model. The FEM material model can predict the local strength of the rivet based on hardness by scaling the flow curves. To estimate the predictive capability of the FEM model, the joint formation of rivets with different graded hardness profiles is compared experimentally and simulative. Based on the validated model, the influence of different rivet hardness profiles on the joint formation is analysed numerically. By adapting the material model, a high level of correlation between the experiment's joint formation and the simulation can be achieved."}],"publication":"Materials Research Proceedings","type":"conference","language":[{"iso":"eng"}],"department":[{"_id":"43"},{"_id":"157"}],"user_id":"7850","_id":"60440","project":[{"_id":"130","name":"TRR 285: TRR 285:  Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen Prozessketten"},{"name":"TRR 285 - C: TRR 285 - Project Area C","_id":"133"},{"name":"TRR 285 – C02: TRR 285 - Subproject C02","_id":"146"},{"_id":"131","name":"TRR 285 - A: TRR 285 - Project Area A"},{"name":"TRR 285 – A01: TRR 285 - Subproject A01","_id":"135"}],"intvolume":"        54","citation":{"ama":"Holtkamp PK, Bielak CR, Bobbert M, Meschut G. Simulation of the joining process of graded hardened multi-range capable rivets. In: <i>Materials Research Proceedings</i>. Vol 54. Materials Research Forum LLC; 2025. doi:<a href=\"https://doi.org/10.21741/9781644903599-153\">10.21741/9781644903599-153</a>","chicago":"Holtkamp, Pia Katharina, Christian Roman Bielak, Mathias Bobbert, and Gerson Meschut. “Simulation of the Joining Process of Graded Hardened Multi-Range Capable Rivets.” In <i>Materials Research Proceedings</i>, Vol. 54. Materials Research Forum LLC, 2025. <a href=\"https://doi.org/10.21741/9781644903599-153\">https://doi.org/10.21741/9781644903599-153</a>.","ieee":"P. K. Holtkamp, C. R. Bielak, M. Bobbert, and G. Meschut, “Simulation of the joining process of graded hardened multi-range capable rivets,” in <i>Materials Research Proceedings</i>, 2025, vol. 54, doi: <a href=\"https://doi.org/10.21741/9781644903599-153\">10.21741/9781644903599-153</a>.","mla":"Holtkamp, Pia Katharina, et al. “Simulation of the Joining Process of Graded Hardened Multi-Range Capable Rivets.” <i>Materials Research Proceedings</i>, vol. 54, Materials Research Forum LLC, 2025, doi:<a href=\"https://doi.org/10.21741/9781644903599-153\">10.21741/9781644903599-153</a>.","short":"P.K. Holtkamp, C.R. Bielak, M. Bobbert, G. Meschut, in: Materials Research Proceedings, Materials Research Forum LLC, 2025.","bibtex":"@inproceedings{Holtkamp_Bielak_Bobbert_Meschut_2025, title={Simulation of the joining process of graded hardened multi-range capable rivets}, volume={54}, DOI={<a href=\"https://doi.org/10.21741/9781644903599-153\">10.21741/9781644903599-153</a>}, booktitle={Materials Research Proceedings}, publisher={Materials Research Forum LLC}, author={Holtkamp, Pia Katharina and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}, year={2025} }","apa":"Holtkamp, P. K., Bielak, C. R., Bobbert, M., &#38; Meschut, G. (2025). Simulation of the joining process of graded hardened multi-range capable rivets. <i>Materials Research Proceedings</i>, <i>54</i>. <a href=\"https://doi.org/10.21741/9781644903599-153\">https://doi.org/10.21741/9781644903599-153</a>"},"year":"2025","publication_identifier":{"issn":["2474-395X"]},"quality_controlled":"1","publication_status":"published","doi":"10.21741/9781644903599-153","title":"Simulation of the joining process of graded hardened multi-range capable rivets","volume":54,"author":[{"full_name":"Holtkamp, Pia Katharina","id":"44935","last_name":"Holtkamp","first_name":"Pia Katharina"},{"first_name":"Christian Roman","id":"34782","full_name":"Bielak, Christian Roman","last_name":"Bielak"},{"full_name":"Bobbert, Mathias","id":"7850","last_name":"Bobbert","first_name":"Mathias"},{"first_name":"Gerson","orcid":"0000-0002-2763-1246","last_name":"Meschut","id":"32056","full_name":"Meschut, Gerson"}],"date_created":"2025-06-27T08:23:00Z","date_updated":"2026-02-24T14:12:10Z","publisher":"Materials Research Forum LLC"},{"citation":{"bibtex":"@article{Harzheim_Chen_Hollmer_Hofmann_Zimmermann_Wallmersperger_2025, title={Numerical investigation of pitting corrosion in clinched joints}, DOI={<a href=\"https://doi.org/10.1007/s00707-025-04248-2\">10.1007/s00707-025-04248-2</a>}, journal={Acta Mechanica}, publisher={Springer Science and Business Media LLC}, author={Harzheim, Sven and Chen, Chin and Hollmer, Katharina and Hofmann, Martin and Zimmermann, Martina and Wallmersperger, Thomas}, year={2025} }","short":"S. Harzheim, C. Chen, K. Hollmer, M. Hofmann, M. Zimmermann, T. Wallmersperger, Acta Mechanica (2025).","mla":"Harzheim, Sven, et al. “Numerical Investigation of Pitting Corrosion in Clinched Joints.” <i>Acta Mechanica</i>, Springer Science and Business Media LLC, 2025, doi:<a href=\"https://doi.org/10.1007/s00707-025-04248-2\">10.1007/s00707-025-04248-2</a>.","apa":"Harzheim, S., Chen, C., Hollmer, K., Hofmann, M., Zimmermann, M., &#38; Wallmersperger, T. (2025). Numerical investigation of pitting corrosion in clinched joints. <i>Acta Mechanica</i>. <a href=\"https://doi.org/10.1007/s00707-025-04248-2\">https://doi.org/10.1007/s00707-025-04248-2</a>","ama":"Harzheim S, Chen C, Hollmer K, Hofmann M, Zimmermann M, Wallmersperger T. Numerical investigation of pitting corrosion in clinched joints. <i>Acta Mechanica</i>. Published online 2025. doi:<a href=\"https://doi.org/10.1007/s00707-025-04248-2\">10.1007/s00707-025-04248-2</a>","ieee":"S. Harzheim, C. Chen, K. Hollmer, M. Hofmann, M. Zimmermann, and T. Wallmersperger, “Numerical investigation of pitting corrosion in clinched joints,” <i>Acta Mechanica</i>, 2025, doi: <a href=\"https://doi.org/10.1007/s00707-025-04248-2\">10.1007/s00707-025-04248-2</a>.","chicago":"Harzheim, Sven, Chin Chen, Katharina Hollmer, Martin Hofmann, Martina Zimmermann, and Thomas Wallmersperger. “Numerical Investigation of Pitting Corrosion in Clinched Joints.” <i>Acta Mechanica</i>, 2025. <a href=\"https://doi.org/10.1007/s00707-025-04248-2\">https://doi.org/10.1007/s00707-025-04248-2</a>."},"year":"2025","publication_status":"published","publication_identifier":{"issn":["0001-5970","1619-6937"]},"doi":"10.1007/s00707-025-04248-2","title":"Numerical investigation of pitting corrosion in clinched joints","author":[{"full_name":"Harzheim, Sven","last_name":"Harzheim","first_name":"Sven"},{"first_name":"Chin","last_name":"Chen","full_name":"Chen, Chin","id":"114741"},{"first_name":"Katharina","full_name":"Hollmer, Katharina","last_name":"Hollmer"},{"first_name":"Martin","last_name":"Hofmann","full_name":"Hofmann, Martin"},{"first_name":"Martina","full_name":"Zimmermann, Martina","last_name":"Zimmermann"},{"first_name":"Thomas","full_name":"Wallmersperger, Thomas","last_name":"Wallmersperger"}],"date_created":"2025-09-23T11:58:18Z","publisher":"Springer Science and Business Media LLC","date_updated":"2026-02-24T15:12:17Z","status":"public","abstract":[{"lang":"eng","text":"<jats:title>Abstract</jats:title>\r\n          <jats:p>The effect of corrosion on mechanically joined components is not well understood. While recent research shows that a brief exposure of clinched specimens to a salt spray environment improves the specimens’ fatigue life, other research shows a decrease in load bearing capabilities with increasing corrosion times. These studies primarily focus on galvanic corrosion. It is not entirely clear how other corrosion phenomena, such as pitting corrosion, affect the fatigue life of clinched joints. In this work, a numerical model is used, which is able to simulate corrosion pit growth in EN AW-6014. The experimental polarization data of EN AW-6014 are used directly in the calculation of the interface kinetics parameter of the model.</jats:p>"}],"type":"journal_article","publication":"Acta Mechanica","language":[{"iso":"eng"}],"user_id":"114741","project":[{"_id":"132","name":"TRR 285 - Project Area B"},{"_id":"142","name":"TRR 285 - Subproject B03"},{"_id":"130","name":"TRR 285:  Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen Prozessketten"}],"_id":"61411"},{"status":"public","abstract":[{"lang":"eng","text":"A finite classical polar space of rank $n$ consists of the totally isotropic\r\nsubspaces of a finite vector space over $\\mathbb{F}_q$ equipped with a\r\nnondegenerate form such that $n$ is the maximal dimension of such a subspace. A\r\n$t$-$(n,k,\\lambda)$ design in a finite classical polar space of rank $n$ is a\r\ncollection $Y$ of totally isotropic $k$-spaces such that each totally isotropic\r\n$t$-space is contained in exactly $\\lambda$ members of $Y$. Nontrivial examples\r\nare currently only known for $t\\leq 2$. We show that $t$-$(n,k,\\lambda)$\r\ndesigns in polar spaces exist for all $t$ and $q$ provided that\r\n$k>\\frac{21}{2}t$ and $n$ is sufficiently large enough. The proof is based on a\r\nprobabilistic method by Kuperberg, Lovett, and Peled, and it is thus\r\nnonconstructive."}],"publication":"Des. Codes Cryptogr.","type":"journal_article","language":[{"iso":"eng"}],"department":[{"_id":"100"}],"user_id":"70420","_id":"50299","intvolume":"        93","page":"971 - 981","citation":{"ama":"Weiß C. Nontrivial $t$-designs in polar spaces exist for all $t$. <i>Des Codes Cryptogr</i>. 2025;93:971-981. doi:<a href=\"https://doi.org/10.1007/s10623-024-01471-1\">10.1007/s10623-024-01471-1</a>","ieee":"C. Weiß, “Nontrivial $t$-designs in polar spaces exist for all $t$,” <i>Des. Codes Cryptogr.</i>, vol. 93, pp. 971–981, 2025, doi: <a href=\"https://doi.org/10.1007/s10623-024-01471-1\">10.1007/s10623-024-01471-1</a>.","chicago":"Weiß, Charlene. “Nontrivial $t$-Designs in Polar Spaces Exist for All $t$.” <i>Des. Codes Cryptogr.</i> 93 (2025): 971–81. <a href=\"https://doi.org/10.1007/s10623-024-01471-1\">https://doi.org/10.1007/s10623-024-01471-1</a>.","apa":"Weiß, C. (2025). Nontrivial $t$-designs in polar spaces exist for all $t$. <i>Des. Codes Cryptogr.</i>, <i>93</i>, 971–981. <a href=\"https://doi.org/10.1007/s10623-024-01471-1\">https://doi.org/10.1007/s10623-024-01471-1</a>","mla":"Weiß, Charlene. “Nontrivial $t$-Designs in Polar Spaces Exist for All $t$.” <i>Des. Codes Cryptogr.</i>, vol. 93, 2025, pp. 971–81, doi:<a href=\"https://doi.org/10.1007/s10623-024-01471-1\">10.1007/s10623-024-01471-1</a>.","bibtex":"@article{Weiß_2025, title={Nontrivial $t$-designs in polar spaces exist for all $t$}, volume={93}, DOI={<a href=\"https://doi.org/10.1007/s10623-024-01471-1\">10.1007/s10623-024-01471-1</a>}, journal={Des. Codes Cryptogr.}, author={Weiß, Charlene}, year={2025}, pages={971–981} }","short":"C. Weiß, Des. Codes Cryptogr. 93 (2025) 971–981."},"year":"2025","publication_status":"published","doi":"10.1007/s10623-024-01471-1","title":"Nontrivial $t$-designs in polar spaces exist for all $t$","volume":93,"date_created":"2024-01-08T14:39:54Z","author":[{"id":"70420","full_name":"Weiß, Charlene","last_name":"Weiß","first_name":"Charlene"}],"date_updated":"2026-02-25T13:51:50Z"},{"volume":33,"author":[{"first_name":"Marius","last_name":"Brinkmann","full_name":"Brinkmann, Marius"},{"first_name":"Falco","full_name":"Meier, Falco","last_name":"Meier"},{"full_name":"Spedt, Vladimir","last_name":"Spedt","first_name":"Vladimir"},{"first_name":"Cedrik","orcid":"https://orcid.org/0000-0002-3787-3572","last_name":"Meier","full_name":"Meier, Cedrik","id":"20798"}],"date_updated":"2026-02-26T09:44:49Z","doi":"10.1364/oe.572063","publication_identifier":{"issn":["1094-4087"]},"publication_status":"published","intvolume":"        33","citation":{"bibtex":"@article{Brinkmann_Meier_Spedt_Meier_2025, title={Boosting third-order nonlinearities in rutile TiO<sub>2</sub> by chromium doping}, volume={33}, DOI={<a href=\"https://doi.org/10.1364/oe.572063\">10.1364/oe.572063</a>}, number={2654320}, journal={Optics Express}, publisher={Optica Publishing Group}, author={Brinkmann, Marius and Meier, Falco and Spedt, Vladimir and Meier, Cedrik}, year={2025} }","short":"M. Brinkmann, F. Meier, V. Spedt, C. Meier, Optics Express 33 (2025).","mla":"Brinkmann, Marius, et al. “Boosting Third-Order Nonlinearities in Rutile TiO<sub>2</sub> by Chromium Doping.” <i>Optics Express</i>, vol. 33, no. 26, 54320, Optica Publishing Group, 2025, doi:<a href=\"https://doi.org/10.1364/oe.572063\">10.1364/oe.572063</a>.","apa":"Brinkmann, M., Meier, F., Spedt, V., &#38; Meier, C. (2025). Boosting third-order nonlinearities in rutile TiO<sub>2</sub> by chromium doping. <i>Optics Express</i>, <i>33</i>(26), Article 54320. <a href=\"https://doi.org/10.1364/oe.572063\">https://doi.org/10.1364/oe.572063</a>","chicago":"Brinkmann, Marius, Falco Meier, Vladimir Spedt, and Cedrik Meier. “Boosting Third-Order Nonlinearities in Rutile TiO<sub>2</sub> by Chromium Doping.” <i>Optics Express</i> 33, no. 26 (2025). <a href=\"https://doi.org/10.1364/oe.572063\">https://doi.org/10.1364/oe.572063</a>.","ieee":"M. Brinkmann, F. Meier, V. Spedt, and C. Meier, “Boosting third-order nonlinearities in rutile TiO<sub>2</sub> by chromium doping,” <i>Optics Express</i>, vol. 33, no. 26, Art. no. 54320, 2025, doi: <a href=\"https://doi.org/10.1364/oe.572063\">10.1364/oe.572063</a>.","ama":"Brinkmann M, Meier F, Spedt V, Meier C. Boosting third-order nonlinearities in rutile TiO<sub>2</sub> by chromium doping. <i>Optics Express</i>. 2025;33(26). doi:<a href=\"https://doi.org/10.1364/oe.572063\">10.1364/oe.572063</a>"},"department":[{"_id":"15"}],"user_id":"20798","_id":"64662","article_number":"54320","type":"journal_article","status":"public","date_created":"2026-02-26T09:43:53Z","publisher":"Optica Publishing Group","title":"Boosting third-order nonlinearities in rutile TiO<sub>2</sub> by chromium doping","issue":"26","year":"2025","language":[{"iso":"eng"}],"publication":"Optics Express","abstract":[{"lang":"eng","text":"<jats:p>\r\n                    In this study, we investigate the impact of chromium-induced point defects on the nonlinear optical properties and electric-field-induced second harmonic generation (EFISH) in rutile titanium dioxide (TiO\r\n                    <jats:sub>2</jats:sub>\r\n                    ). Chromium thin films were deposited by electron beam evaporation on (001)-oriented bulk TiO\r\n                    <jats:sub>2</jats:sub>\r\n                    substrates and subsequently diffused into the lattice in a tube furnace under a nitrogen atmosphere at 900 °C. The introduction of chromium significantly enhanced the third harmonic generation (THG) of a 1560 nm laser, with an amplification factor of up to 8.3, indicative of an enhanced third-order nonlinear susceptibility,\r\n                    <jats:italic>χ</jats:italic>\r\n                    <jats:sup>(3)</jats:sup>\r\n                    . Moreover, the application of an external voltage induced a pronounced EFISH signal in the chromium-doped samples, further confirming the enhanced nonlinear response. These results demonstrate that defect engineering via chromium doping in rutile TiO\r\n                    <jats:sub>2</jats:sub>\r\n                    offers a promising pathway for the development of high-performance nonlinear optical devices.\r\n                  </jats:p>"}]},{"oa":"1","date_updated":"2026-03-02T11:04:56Z","author":[{"full_name":"Scheidemann, Claus","id":"38259","last_name":"Scheidemann","first_name":"Claus"},{"first_name":"Peter","last_name":"Bornmann","full_name":"Bornmann, Peter"},{"full_name":"Littmann, Walter","last_name":"Littmann","first_name":"Walter"},{"id":"210","full_name":"Hemsel, Tobias","last_name":"Hemsel","first_name":"Tobias"}],"date_created":"2026-03-02T10:39:40Z","title":"Bolted Langevin transducers with leadfree piezoelectric ceramics","conference":{"name":"International Workshop on Piezoelectric Materials and Applications in Actuators (IWPMA)","start_date":"2025-07-01","end_date":"2025-07-03","location":"Vilnius, Lithuania"},"has_accepted_license":"1","year":"2025","citation":{"chicago":"Scheidemann, Claus, Peter Bornmann, Walter Littmann, and Tobias Hemsel. “Bolted Langevin Transducers with Leadfree Piezoelectric Ceramics,” 2025.","ieee":"C. Scheidemann, P. Bornmann, W. Littmann, and T. Hemsel, “Bolted Langevin transducers with leadfree piezoelectric ceramics,” presented at the International Workshop on Piezoelectric Materials and Applications in Actuators (IWPMA), Vilnius, Lithuania, 2025.","ama":"Scheidemann C, Bornmann P, Littmann W, Hemsel T. Bolted Langevin transducers with leadfree piezoelectric ceramics. In: ; 2025.","apa":"Scheidemann, C., Bornmann, P., Littmann, W., &#38; Hemsel, T. (2025). <i>Bolted Langevin transducers with leadfree piezoelectric ceramics</i>. International Workshop on Piezoelectric Materials and Applications in Actuators (IWPMA), Vilnius, Lithuania.","bibtex":"@inproceedings{Scheidemann_Bornmann_Littmann_Hemsel_2025, title={Bolted Langevin transducers with leadfree piezoelectric ceramics}, author={Scheidemann, Claus and Bornmann, Peter and Littmann, Walter and Hemsel, Tobias}, year={2025} }","mla":"Scheidemann, Claus, et al. <i>Bolted Langevin Transducers with Leadfree Piezoelectric Ceramics</i>. 2025.","short":"C. Scheidemann, P. Bornmann, W. Littmann, T. Hemsel, in: 2025."},"_id":"64798","user_id":"210","department":[{"_id":"151"}],"ddc":["620"],"keyword":["lead free piezoelectric ceramics","bolted Langevin transducer","medium power ultrasound."],"language":[{"iso":"eng"}],"file_date_updated":"2026-03-02T11:00:37Z","type":"conference","abstract":[{"text":"Lead-containing piezoelectric ceramics are still the base for today’s ultrasonic transducers used in broad applications. This is partly due to missing powerful lead-free piezoelectric ceramic parts in the commercial market. There has been much research on lead-free materials but developing them into marketable parts seems to be an ongoing process. The actual exemption of ROHS has expired, but as the new exemption has already been requested, ceramic suppliers keep on selling lead containing products. Nevertheless, these should be replaced by lead-free alternatives for environmental and health issues. \r\nThis contribution focuses on exploring the technological readiness level of lead-free hard piezoceramics for prestressed ultrasonic transducers. A small series of bolted Langevin transducers was set up with standard PZT material and three commercial lead-free variants. Results of the building process from individual ring ceramic characteristics to transducer load tests are presented. The main finding of this study is that the lead-free materials technically can compete with the standard PZT for medium-power applications. Some adaptations in the ultrasonic system must be done: the geometry must be altered to fit resonance frequency, and higher voltages or thinner ceramics are needed to achieve the same vibration level at low load. For reaching same power, the volume of lead-free ceramics must be 1.5 to 3 times larger. As already promoted in literature, mechanical losses at high vibration levels are smaller for the lead-free materials. This might help to argument lead-free piezoelectric materials in some applications.\r\n\r\nReferences\r\n1.\tDirective 2011/65/EU of the European Parliament and of the Council of 8 June 2011 on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment. EUR-Lex Document 02011L0065-20240801. Available online: http://data.europa.eu/eli/dir/2011/65/2024-08-01 (accessed on 24 January 2025).\r\n2.\tLangevin, P. (1918) Method and Apparatus for Transmitting and Receiving Submarine Elastic Waves Using the Piezoelectric Properties of Quartz. French Patent Office; Patent No. FR505703.\r\n3.\tHemsel, T.; Twiefel, J. (2023) Piezoelectric Ultrasonic Power Transducers. In Encyclopedia of Materials: Electronics; Academic Press: Oxford, UK; pp. 276–285. https://doi.org/10.1016/b978-0-12-819728-8.00047-4.\r\n4.\tATHENA Technologie Beratung GmbH (2025) Description of Ultrasound Generator. Available online: http://shop.myathena.de/epages/12074748.sf/de_DE/?ObjectPath=/Shops/12074748/Products/AM200 (accessed on 13 January 2025).\r\n5.\tLittmann, W.; Hemsel, T.; Kauczor, C.; Wallaschek, J.; Sinha, W. (2003) Load-adaptive phase-controller for resonant driven piezoelectric devices. Proc. World Congr. Ultrason. 2003, 48, 547–550.\r\n6.\tScheidemann, C., Bornmann, P., Littmann, W., & Hemsel, T. (2025). Lead-Free Ceramics in Prestressed Ultrasonic Transducers. Actuators, 14(2), 55. https://doi.org/10.3390/act14020055\r\n","lang":"eng"}],"file":[{"date_updated":"2026-03-02T11:00:37Z","date_created":"2026-03-02T10:37:46Z","creator":"hemsel","file_size":1812289,"file_id":"64799","file_name":"IWPMA_2025_Hemsel.pdf","access_level":"open_access","content_type":"application/pdf","relation":"main_file"}],"status":"public"},{"conference":{"start_date":"2025-09-21","name":"International Congress on Ultrasonics (ICU)","location":"Paderborn, Germany","end_date":"2025-09-25"},"title":"Intensive ultrasonic cleaning of surfaces by means of lead-free ultrasonic transducer with focussing sonotrode","date_created":"2026-03-02T10:47:48Z","author":[{"id":"210","full_name":"Hemsel, Tobias","last_name":"Hemsel","first_name":"Tobias"},{"last_name":"Scheidemann","id":"38259","full_name":"Scheidemann, Claus","first_name":"Claus"},{"first_name":"Peter","full_name":"Bornmann, Peter","last_name":"Bornmann"},{"full_name":"Littmann, Walter","last_name":"Littmann","first_name":"Walter"},{"last_name":"Sextro","full_name":"Sextro, Walter","id":"21220","first_name":"Walter"}],"oa":"1","date_updated":"2026-03-02T10:58:37Z","citation":{"apa":"Hemsel, T., Scheidemann, C., Bornmann, P., Littmann, W., &#38; Sextro, W. (2025). <i>Intensive ultrasonic cleaning of surfaces by means of lead-free ultrasonic transducer with focussing sonotrode</i>. International Congress on Ultrasonics (ICU), Paderborn, Germany.","ama":"Hemsel T, Scheidemann C, Bornmann P, Littmann W, Sextro W. Intensive ultrasonic cleaning of surfaces by means of lead-free ultrasonic transducer with focussing sonotrode. In: ; 2025.","short":"T. Hemsel, C. Scheidemann, P. Bornmann, W. Littmann, W. Sextro, in: 2025.","bibtex":"@inproceedings{Hemsel_Scheidemann_Bornmann_Littmann_Sextro_2025, title={Intensive ultrasonic cleaning of surfaces by means of lead-free ultrasonic transducer with focussing sonotrode}, author={Hemsel, Tobias and Scheidemann, Claus and Bornmann, Peter and Littmann, Walter and Sextro, Walter}, year={2025} }","mla":"Hemsel, Tobias, et al. <i>Intensive Ultrasonic Cleaning of Surfaces by Means of Lead-Free Ultrasonic Transducer with Focussing Sonotrode</i>. 2025.","chicago":"Hemsel, Tobias, Claus Scheidemann, Peter Bornmann, Walter Littmann, and Walter Sextro. “Intensive Ultrasonic Cleaning of Surfaces by Means of Lead-Free Ultrasonic Transducer with Focussing Sonotrode,” 2025.","ieee":"T. Hemsel, C. Scheidemann, P. Bornmann, W. Littmann, and W. Sextro, “Intensive ultrasonic cleaning of surfaces by means of lead-free ultrasonic transducer with focussing sonotrode,” presented at the International Congress on Ultrasonics (ICU), Paderborn, Germany, 2025."},"year":"2025","has_accepted_license":"1","language":[{"iso":"eng"}],"file_date_updated":"2026-03-02T10:58:37Z","ddc":["620"],"user_id":"210","department":[{"_id":"151"}],"_id":"64800","file":[{"relation":"main_file","content_type":"application/pdf","file_size":1946202,"file_id":"64801","file_name":"ICU_2025_Hemsel.pdf","access_level":"open_access","date_updated":"2026-03-02T10:58:37Z","creator":"hemsel","date_created":"2026-03-02T10:46:43Z"}],"status":"public","abstract":[{"text":"Intensive ultrasonic cleaning of surfaces by means of a lead-free ultrasonic transducer with focusing sonotrode\r\nUltrasonic cleaning baths are probably a coincidental development: After underwater sonars had already been successfully used to detect submarines before 1920, it was probably observed in this environment that the ultrasonic oscillators not only showed a self-cleaning effect but also cavitation damage. At the beginning of the 1950s, the first ultrasonic cleaning devices finally came onto the market. Today, the range of applications ranges from household appliances for jewellery and eyewear cleaning to classic cleaning baths for metal parts and systems for cleaning highly sensitive electronic components. There is a certain gap in handheld, mobile cleaning equipment. Although devices for spot cleaning of textiles are known, the cleaning effect is usually low. \r\nDue to the directive 2011/65/EU on the restriction of the use of hazardous substances in electrical and electronic equipment (RoHS) [1] lead should no longer be used in technical devices. As today’s standard ceramics for medium and high-power ultrasonic transducers typically contain lead, there is a need to explore the use of lead-free ceramics in this field. Honda [2] already offers a cleaning transducer based on lead-free piezoelectric ceramics, but it is designed to be used in cleaning baths.\r\nThis article presents the model-based development of a highly innovative ultrasonic cleaner. On the one hand, lead-free piezoelectric ceramics are used, and on the other hand, a special sonotrode has been developed that concentrates the sound in such a way that a strong cavitation and thus cleaning effect is achieved with comparatively low power in a short time. Coupled field finite element method was used to find an appropriate geometry for the focussing sonotrode. The comparison of simulation and measurement results shows that the lead-free piezoceramics used do their job well and can keep up with standard ceramics, but more ceramic volume is needed to achieve same power. An advanced control concept was elaborated to ensure continuous hard cavitation at varying distances between the sonotrode and the part to be cleaned. Cleaning results for different surfaces and contaminations are presented. The concept of the focusing sonotrode shows that a convincing cleaning result can be achieved even with low power and in short time, provided that the oscillation system and control electronics are suitably coordinated.\r\n\r\nReferences\r\n[1] http://data.europa.eu/eli/dir/2011/65/2024-08-01 \r\n[2] https://en.honda-el.co.jp/product/ceramics/lineup/lead_off/lead-off \r\n","lang":"eng"}],"type":"conference"},{"year":"2025","issue":"7","title":"Overcoming Digital Inequalities—Identification and Characterisation of Digitally Resilient Schools in Different Countries Using ICILS 2023 Data","date_created":"2026-03-04T09:38:17Z","publisher":"MDPI AG","abstract":[{"lang":"eng","text":"<jats:p>(1) Background: As digitalisation transforms society, digital competences are increasingly essential. Yet students’ digital competences often vary significantly, largely influenced by socio-economic background. Some schools—termed “resilient schools”—effectively counter these disadvantages and foster high digital competence. This study investigates the prevalence of such schools and examines how they differ from others. (2) Methods: Drawing on representative ICILS 2023 data, quantitative secondary analyses—including descriptive statistics, t-tests, and multiple regression—were conducted. Following the identification of resilient schools, in-depth analyses focus on those countries with substantial proportions of resilient schools above 10 percent (Austria, Italy, and Portugal), as these countries seem to have effective strategies to foster school resilience. (3) Results: The findings highlight considerable cross-national variation, indicating that school resilience is context-dependent. Resilient schools consistently emphasise student learning-related factors—such as ICT-related attitudes and educational aspirations—while the influence of home environments is less pronounced than in other schools. (4) Conclusions: Strengthening student learning-related factors appears to be crucial for building digital resilience. These insights can inform policy and practice aimed at fostering educational equity and closing the digital divide, particularly in socio-economically disadvantaged contexts.</jats:p>"}],"publication":"Education Sciences","language":[{"iso":"eng"}],"intvolume":"        15","citation":{"ieee":"J. Niemann, B. Eickelmann, and K. Drossel, “Overcoming Digital Inequalities—Identification and Characterisation of Digitally Resilient Schools in Different Countries Using ICILS 2023 Data,” <i>Education Sciences</i>, vol. 15, no. 7, Art. no. 898, 2025, doi: <a href=\"https://doi.org/10.3390/educsci15070898\">10.3390/educsci15070898</a>.","chicago":"Niemann, Jan, Birgit Eickelmann, and Kerstin Drossel. “Overcoming Digital Inequalities—Identification and Characterisation of Digitally Resilient Schools in Different Countries Using ICILS 2023 Data.” <i>Education Sciences</i> 15, no. 7 (2025). <a href=\"https://doi.org/10.3390/educsci15070898\">https://doi.org/10.3390/educsci15070898</a>.","ama":"Niemann J, Eickelmann B, Drossel K. Overcoming Digital Inequalities—Identification and Characterisation of Digitally Resilient Schools in Different Countries Using ICILS 2023 Data. <i>Education Sciences</i>. 2025;15(7). doi:<a href=\"https://doi.org/10.3390/educsci15070898\">10.3390/educsci15070898</a>","apa":"Niemann, J., Eickelmann, B., &#38; Drossel, K. (2025). Overcoming Digital Inequalities—Identification and Characterisation of Digitally Resilient Schools in Different Countries Using ICILS 2023 Data. <i>Education Sciences</i>, <i>15</i>(7), Article 898. <a href=\"https://doi.org/10.3390/educsci15070898\">https://doi.org/10.3390/educsci15070898</a>","bibtex":"@article{Niemann_Eickelmann_Drossel_2025, title={Overcoming Digital Inequalities—Identification and Characterisation of Digitally Resilient Schools in Different Countries Using ICILS 2023 Data}, volume={15}, DOI={<a href=\"https://doi.org/10.3390/educsci15070898\">10.3390/educsci15070898</a>}, number={7898}, journal={Education Sciences}, publisher={MDPI AG}, author={Niemann, Jan and Eickelmann, Birgit and Drossel, Kerstin}, year={2025} }","mla":"Niemann, Jan, et al. “Overcoming Digital Inequalities—Identification and Characterisation of Digitally Resilient Schools in Different Countries Using ICILS 2023 Data.” <i>Education Sciences</i>, vol. 15, no. 7, 898, MDPI AG, 2025, doi:<a href=\"https://doi.org/10.3390/educsci15070898\">10.3390/educsci15070898</a>.","short":"J. Niemann, B. Eickelmann, K. Drossel, Education Sciences 15 (2025)."},"publication_identifier":{"issn":["2227-7102"]},"publication_status":"published","doi":"10.3390/educsci15070898","volume":15,"author":[{"first_name":"Jan","last_name":"Niemann","full_name":"Niemann, Jan"},{"last_name":"Eickelmann","full_name":"Eickelmann, Birgit","first_name":"Birgit"},{"last_name":"Drossel","full_name":"Drossel, Kerstin","first_name":"Kerstin"}],"date_updated":"2026-03-04T09:41:33Z","status":"public","type":"journal_article","article_number":"898","department":[{"_id":"462"}],"user_id":"40387","_id":"64824"},{"year":"2025","citation":{"apa":"Hilgert, J. (2025). Quantum-Classical Correspondences for Locally Symmetric Spaces. In <i>Symmetry in Geometry and Analysis, Volume 2</i>. <a href=\"https://doi.org/10.1007/978-981-97-7662-7\">https://doi.org/10.1007/978-981-97-7662-7</a>","mla":"Hilgert, Joachim. “Quantum-Classical Correspondences for Locally Symmetric Spaces.” <i>Symmetry in Geometry and Analysis, Volume 2</i>, 2025, doi:<a href=\"https://doi.org/10.1007/978-981-97-7662-7\">https://doi.org/10.1007/978-981-97-7662-7</a>.","short":"J. Hilgert, in: Symmetry in Geometry and Analysis, Volume 2, 2025.","bibtex":"@inbook{Hilgert_2025, title={Quantum-Classical Correspondences for Locally Symmetric Spaces}, DOI={<a href=\"https://doi.org/10.1007/978-981-97-7662-7\">https://doi.org/10.1007/978-981-97-7662-7</a>}, booktitle={Symmetry in Geometry and Analysis, Volume 2}, author={Hilgert, Joachim}, year={2025} }","ieee":"J. Hilgert, “Quantum-Classical Correspondences for Locally Symmetric Spaces,” in <i>Symmetry in Geometry and Analysis, Volume 2</i>, 2025.","chicago":"Hilgert, Joachim. “Quantum-Classical Correspondences for Locally Symmetric Spaces.” In <i>Symmetry in Geometry and Analysis, Volume 2</i>, 2025. <a href=\"https://doi.org/10.1007/978-981-97-7662-7\">https://doi.org/10.1007/978-981-97-7662-7</a>.","ama":"Hilgert J. Quantum-Classical Correspondences for Locally Symmetric Spaces. In: <i>Symmetry in Geometry and Analysis, Volume 2</i>. ; 2025. doi:<a href=\"https://doi.org/10.1007/978-981-97-7662-7\">https://doi.org/10.1007/978-981-97-7662-7</a>"},"date_updated":"2025-02-11T18:10:35Z","date_created":"2025-02-11T17:59:07Z","author":[{"first_name":"Joachim","last_name":"Hilgert","id":"220","full_name":"Hilgert, Joachim"}],"title":"Quantum-Classical Correspondences for Locally Symmetric Spaces","doi":"https://doi.org/10.1007/978-981-97-7662-7","main_file_link":[{"url":"https://link.springer.com/chapter/10.1007/978-981-97-7662-7_7"}],"publication":"Symmetry in Geometry and Analysis, Volume 2","type":"book_chapter","status":"public","_id":"58587","user_id":"220","language":[{"iso":"eng"}]},{"publication_status":"published","publication_identifier":{"issn":["0938-8974","1432-1467"]},"issue":"2","year":"2025","citation":{"apa":"Hariz Belgacem, K., Jiménez, F., &#38; Ober-Blöbaum, S. (2025). Fractional Variational Integrators Based on Convolution Quadrature. <i>Journal of Nonlinear Science</i>, <i>35</i>(2), Article 38. <a href=\"https://doi.org/10.1007/s00332-025-10131-0\">https://doi.org/10.1007/s00332-025-10131-0</a>","short":"K. Hariz Belgacem, F. Jiménez, S. Ober-Blöbaum, Journal of Nonlinear Science 35 (2025).","mla":"Hariz Belgacem, Khaled, et al. “Fractional Variational Integrators Based on Convolution Quadrature.” <i>Journal of Nonlinear Science</i>, vol. 35, no. 2, 38, Springer Science and Business Media LLC, 2025, doi:<a href=\"https://doi.org/10.1007/s00332-025-10131-0\">10.1007/s00332-025-10131-0</a>.","bibtex":"@article{Hariz Belgacem_Jiménez_Ober-Blöbaum_2025, title={Fractional Variational Integrators Based on Convolution Quadrature}, volume={35}, DOI={<a href=\"https://doi.org/10.1007/s00332-025-10131-0\">10.1007/s00332-025-10131-0</a>}, number={238}, journal={Journal of Nonlinear Science}, publisher={Springer Science and Business Media LLC}, author={Hariz Belgacem, Khaled and Jiménez, Fernando and Ober-Blöbaum, Sina}, year={2025} }","ieee":"K. Hariz Belgacem, F. Jiménez, and S. Ober-Blöbaum, “Fractional Variational Integrators Based on Convolution Quadrature,” <i>Journal of Nonlinear Science</i>, vol. 35, no. 2, Art. no. 38, 2025, doi: <a href=\"https://doi.org/10.1007/s00332-025-10131-0\">10.1007/s00332-025-10131-0</a>.","chicago":"Hariz Belgacem, Khaled, Fernando Jiménez, and Sina Ober-Blöbaum. “Fractional Variational Integrators Based on Convolution Quadrature.” <i>Journal of Nonlinear Science</i> 35, no. 2 (2025). <a href=\"https://doi.org/10.1007/s00332-025-10131-0\">https://doi.org/10.1007/s00332-025-10131-0</a>.","ama":"Hariz Belgacem K, Jiménez F, Ober-Blöbaum S. Fractional Variational Integrators Based on Convolution Quadrature. <i>Journal of Nonlinear Science</i>. 2025;35(2). doi:<a href=\"https://doi.org/10.1007/s00332-025-10131-0\">10.1007/s00332-025-10131-0</a>"},"intvolume":"        35","date_updated":"2025-02-24T11:55:58Z","publisher":"Springer Science and Business Media LLC","date_created":"2025-02-24T11:52:16Z","author":[{"full_name":"Hariz Belgacem, Khaled","last_name":"Hariz Belgacem","first_name":"Khaled"},{"first_name":"Fernando","last_name":"Jiménez","full_name":"Jiménez, Fernando"},{"first_name":"Sina","full_name":"Ober-Blöbaum, Sina","last_name":"Ober-Blöbaum"}],"volume":35,"title":"Fractional Variational Integrators Based on Convolution Quadrature","doi":"10.1007/s00332-025-10131-0","type":"journal_article","publication":"Journal of Nonlinear Science","abstract":[{"text":"<jats:title>Abstract</jats:title>\n          <jats:p>Fractional dissipation is a powerful tool to study nonlocal physical phenomena such as damping models. The design of geometric, in particular, variational integrators for the numerical simulation of such systems relies on a variational formulation of the model. In Jiménez and Ober-Blöbaum (J Nonlinear Sci 31:46, 2021), a new approach is proposed to deal with dissipative systems including fractionally damped systems in a variational way for both, the continuous and discrete setting. It is based on the doubling of variables and their fractional derivatives. The aim of this work is to derive higher-order fractional variational integrators by means of convolution quadrature (CQ) based on backward difference formulas. We then provide numerical methods that are of order 2 improving a previous result in Jiménez and Ober-Blöbaum (J Nonlinear Sci 31:46, 2021). The convergence properties of the fractional variational integrators and saturation effects due to the approximation of the fractional derivatives by CQ are studied numerically.</jats:p>","lang":"eng"}],"status":"public","_id":"58811","user_id":"98857","article_number":"38","language":[{"iso":"eng"}]},{"keyword":["elucidation","facts","Frege","language","metaphysics","G. E. Moore","Russell","Stebbing","John Wisdom","Wittgenstein"],"language":[{"iso":"eng"}],"_id":"58822","user_id":"357","department":[{"_id":"14"}],"editor":[{"first_name":"Ali Hossein ","full_name":"Khani , Ali Hossein ","last_name":"Khani "},{"full_name":"Kemp , Gary ","last_name":"Kemp ","first_name":"Gary "}],"abstract":[{"lang":"eng","text":"In 1921, John Wisdom (1904–1993) became a member of Fitzwilliam House, Cambridge, where he read philosophy and attended lectures by G. E. Moore, C. D. Broad, and J. E. McTaggart. He received his BA in 1924, after which he worked for five years at the National Institute of Industrial Psychology. From 1929 to 1934, Wisdom was a Lecturer in the department of logic and metaphysics at the University of St Andrews and a colleague of G. F. Stout. After the publication of his book Interpretation and Analysis (1931) and five articles on “Logical Constructions” in Mind (1931–3), Wisdom became a Lecturer in Moral Sciences in Cambridge and a Fellow of Trinity College. This gave him the opportunity to gain first-hand knowledge of Wittgenstein’s philosophy. Since nothing by Wittgenstein but Tractatus appeared in print for decades, Wisdom’s publications of these years were—mistakenly—read as portents of the new ideas of Wittgenstein himself. The publication of Wittgenstein’s Philosophical Investigations in 1953 brought with it, among other things, the fall of Wisdom’s popularity. "}],"status":"public","type":"book_chapter","publication":"Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 vol., Volume II","title":"Wisdom's Wittgenstein","date_updated":"2025-02-24T18:38:38Z","publisher":"Routledge","author":[{"first_name":"Nikolay","id":"357","full_name":"Milkov, Nikolay","last_name":"Milkov"}],"date_created":"2025-02-24T18:33:50Z","year":"2025","place":"London","citation":{"mla":"Milkov, Nikolay. “Wisdom’s Wittgenstein.” <i>Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 Vol., Volume II</i>, edited by Ali Hossein  Khani  and Gary  Kemp , 1st ed., Routledge.","bibtex":"@inbook{Milkov, place={London}, edition={1}, title={Wisdom’s Wittgenstein}, booktitle={Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 vol., Volume II}, publisher={Routledge}, author={Milkov, Nikolay}, editor={Khani , Ali Hossein  and Kemp , Gary } }","short":"N. Milkov, in: A.H. Khani , G. Kemp  (Eds.), Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 Vol., Volume II, 1st ed., Routledge, London, n.d.","apa":"Milkov, N. (n.d.). Wisdom’s Wittgenstein. In A. H. Khani  &#38; G. Kemp  (Eds.), <i>Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 vol., Volume II</i> (1st ed.). Routledge.","ama":"Milkov N. Wisdom’s Wittgenstein. In: Khani  AH, Kemp  G, eds. <i>Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 Vol., Volume II</i>. 1st ed. Routledge.","chicago":"Milkov, Nikolay. “Wisdom’s Wittgenstein.” In <i>Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 Vol., Volume II</i>, edited by Ali Hossein  Khani  and Gary  Kemp , 1st ed. London: Routledge, n.d.","ieee":"N. Milkov, “Wisdom’s Wittgenstein,” in <i>Wittgenstein and Other Philosophers: His Influence on Historical and Contemporary Analytic Philosophers, 2 vol., Volume II</i>, 1st ed., A. H. Khani  and G. Kemp , Eds. London: Routledge."},"publication_status":"inpress","quality_controlled":"1","edition":"1"},{"doi":"10.1007/s00216-025-05803-5","title":"Monitoring phage infection and lysis of surface-immobilized bacteria by QCM-D","author":[{"full_name":"Pothineni, Bhanu K.","last_name":"Pothineni","first_name":"Bhanu K."},{"last_name":"Probst","full_name":"Probst, René","first_name":"René"},{"last_name":"Kiefer","full_name":"Kiefer, Dorothee","first_name":"Dorothee"},{"first_name":"Verena","last_name":"Dobretzberger","full_name":"Dobretzberger, Verena"},{"first_name":"Ivan","full_name":"Barišić, Ivan","last_name":"Barišić"},{"first_name":"Guido","last_name":"Grundmeier","full_name":"Grundmeier, Guido","id":"194"},{"id":"48864","full_name":"Keller, Adrian","orcid":"0000-0001-7139-3110","last_name":"Keller","first_name":"Adrian"}],"date_created":"2025-02-26T09:23:19Z","publisher":"Springer Science and Business Media LLC","date_updated":"2025-02-26T09:23:43Z","citation":{"apa":"Pothineni, B. K., Probst, R., Kiefer, D., Dobretzberger, V., Barišić, I., Grundmeier, G., &#38; Keller, A. (2025). Monitoring phage infection and lysis of surface-immobilized bacteria by QCM-D. <i>Analytical and Bioanalytical Chemistry</i>. <a href=\"https://doi.org/10.1007/s00216-025-05803-5\">https://doi.org/10.1007/s00216-025-05803-5</a>","mla":"Pothineni, Bhanu K., et al. “Monitoring Phage Infection and Lysis of Surface-Immobilized Bacteria by QCM-D.” <i>Analytical and Bioanalytical Chemistry</i>, Springer Science and Business Media LLC, 2025, doi:<a href=\"https://doi.org/10.1007/s00216-025-05803-5\">10.1007/s00216-025-05803-5</a>.","bibtex":"@article{Pothineni_Probst_Kiefer_Dobretzberger_Barišić_Grundmeier_Keller_2025, title={Monitoring phage infection and lysis of surface-immobilized bacteria by QCM-D}, DOI={<a href=\"https://doi.org/10.1007/s00216-025-05803-5\">10.1007/s00216-025-05803-5</a>}, journal={Analytical and Bioanalytical Chemistry}, publisher={Springer Science and Business Media LLC}, author={Pothineni, Bhanu K. and Probst, René and Kiefer, Dorothee and Dobretzberger, Verena and Barišić, Ivan and Grundmeier, Guido and Keller, Adrian}, year={2025} }","short":"B.K. Pothineni, R. Probst, D. Kiefer, V. Dobretzberger, I. Barišić, G. Grundmeier, A. Keller, Analytical and Bioanalytical Chemistry (2025).","ama":"Pothineni BK, Probst R, Kiefer D, et al. Monitoring phage infection and lysis of surface-immobilized bacteria by QCM-D. <i>Analytical and Bioanalytical Chemistry</i>. Published online 2025. doi:<a href=\"https://doi.org/10.1007/s00216-025-05803-5\">10.1007/s00216-025-05803-5</a>","ieee":"B. K. Pothineni <i>et al.</i>, “Monitoring phage infection and lysis of surface-immobilized bacteria by QCM-D,” <i>Analytical and Bioanalytical Chemistry</i>, 2025, doi: <a href=\"https://doi.org/10.1007/s00216-025-05803-5\">10.1007/s00216-025-05803-5</a>.","chicago":"Pothineni, Bhanu K., René Probst, Dorothee Kiefer, Verena Dobretzberger, Ivan Barišić, Guido Grundmeier, and Adrian Keller. “Monitoring Phage Infection and Lysis of Surface-Immobilized Bacteria by QCM-D.” <i>Analytical and Bioanalytical Chemistry</i>, 2025. <a href=\"https://doi.org/10.1007/s00216-025-05803-5\">https://doi.org/10.1007/s00216-025-05803-5</a>."},"year":"2025","publication_identifier":{"issn":["1618-2642","1618-2650"]},"publication_status":"published","language":[{"iso":"eng"}],"department":[{"_id":"302"}],"user_id":"48864","_id":"58853","status":"public","abstract":[{"lang":"eng","text":"<jats:title>Abstract</jats:title>\r\n          <jats:p>While being a promising approach for the treatment of infections caused by drug-resistant, pathogenic bacteria, the clinical implementation of phage therapy still faces several challenges. One of these challenges lies in the high strain-specificity of most bacteriophages, which makes it necessary to screen large phage collections against the target pathogens in order to identify suitable candidates for the formulations of personalized therapeutic phage cocktails. In this work, we evaluate the potential of quartz crystal microbalance with dissipation monitoring (QCM-D) to identify and detect phage infection and subsequent lysis of bacteria immobilized on the surfaces of the QCM-D sensors. Using lytic <jats:italic>Escherichia coli</jats:italic> phage T7 as a model, we show that phage infection of <jats:italic>E. coli</jats:italic> cells results in various unique alterations in the behaviors of the frequency (Δ<jats:italic>f</jats:italic>) and dissipation (Δ<jats:italic>D</jats:italic>) signals, which are not observed during exposure of the <jats:italic>E. coli</jats:italic> strain to non-infectious <jats:italic>Bacillus subtilis</jats:italic> phage phi29 at similar concentration. To aid future phage screening campaigns, we furthermore identify a single measurement parameter, i.e., the spread between the different overtones of Δ<jats:italic>D</jats:italic>, that can be used to detect phage-induced lysis. For T7 infection of <jats:italic>E. coli</jats:italic>, this is achieved within 4 h after inoculation, including immobilization and growth of the bacteria on the sensor surface, as well as the completed phage propagation cycle. Given the commercial availability of highly automated multichannel systems and the fact that this approach does not require any sensor modifications, QCM-D has the potential to become a valuable tool for screening medium-sized phage collections against target pathogens.</jats:p>\r\n          <jats:p>\r\n            <jats:bold>Graphical Abstract</jats:bold>\r\n          </jats:p>"}],"publication":"Analytical and Bioanalytical Chemistry","type":"journal_article"}]