@article{35707, abstract = {{The proton conductivity of two coordination networks, [Mg(H2O)2(H3L)]·H2O and [Pb2(HL)]·H2O (H5L = (H2O3PCH2)2-NCH2-C6H4-SO3H), is investigated by AC impedance spectroscopy. Both materials contain the same phosphonato-sulfonate linker molecule, but have clearly different crystal structures, which has a strong effect on proton conductivity. In the Mg-based coordination network, dangling sulfonate groups are part of an extended hydrogen bonding network, facilitating a “proton hopping” with low activation energy; the material shows a moderate proton conductivity. In the Pb-based metal-organic framework, in contrast, no extended hydrogen bonding occurs, as the sulfonate groups coordinate to Pb2+, without forming hydrogen bonds; the proton conductivity is much lower in this material.}}, author = {{Javed, Ali and Steinke, Felix and Wöhlbrandt, Stephan and Bunzen, Hana and Stock, Norbert and Tiemann, Michael}}, issn = {{2190-4286}}, journal = {{Beilstein Journal of Nanotechnology}}, keywords = {{Electrical and Electronic Engineering, General Physics and Astronomy, General Materials Science}}, pages = {{437--443}}, publisher = {{Beilstein Institut}}, title = {{{The role of sulfonate groups and hydrogen bonding in the proton conductivity of two coordination networks}}}, doi = {{10.3762/bjnano.13.36}}, volume = {{13}}, year = {{2022}}, } @article{33691, abstract = {{Near ambient pressure XPS in nitrogen atmosphere was utilized to investigate gas-solid interactions within porous SiO2 films ranging from 30 to 75 nm thickness. The films were differentiated in terms of porosity and roughness. The XPS N1s core levels of the N2 gas in presence of the SiO2 samples showed variations in width, binding energy and line shape. The width correlated with the surface charge induced in the dielectric films upon X-ray irradiation. The observed different binding energies observed for the N1s peak can only partly be associated with intrinsic work function differences between the samples, opening the possibility that the effect of physisorption at room temperature could be detected by a shift in the measured binding energy. However, the signals also show an increasing asymmetry with rising surface charge. This might be associated with the formation of vertical electrical gradients within the dielectric porous thin films, which complicates the assignment of binding energy positions to specific surface-related effects. With the support of Monte Carlo and first principles density functional theory calculations, the observed shifts were discussed in terms of the possible formation of transitory dipoles upon N2 physisorption within the porous SiO2 films.}}, author = {{de los Arcos, Teresa and Weinberger, Christian and Zysk, Frederik and Raj Damerla, Varun and Kollmann, Sabrina and Vieth, Pascal and Tiemann, Michael and Kühne, Thomas and Grundmeier, Guido}}, issn = {{0169-4332}}, journal = {{Applied Surface Science}}, keywords = {{Surfaces, Coatings and Films, Condensed Matter Physics, Surfaces and Interfaces, General Physics and Astronomy, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Challenges in the interpretation of gas core levels for the determination of gas-solid interactions within dielectric porous films by ambient pressure XPS}}}, doi = {{10.1016/j.apsusc.2022.154525}}, volume = {{604}}, year = {{2022}}, } @article{33685, abstract = {{In the spatial confinement of cylindrical mesopores with diameters of a few nanometers, water molecules experience restrictions in hydrogen bonding. This leads to a different behavior regarding the molecular orientational freedom (‘structure of water') compared to the bulk liquid state. In addition to the pore size, the behavior is also strongly affected by the strength of the pore wall-to-water interactions, that is, the pore wall polarity. In this work, this is studied both experimentally and theoretically. The surface polarity of mesoporous silica (SiO2) is modified by functionalization with trimethylsilyl moieties, resulting in a change from a hydrophilic (pristine) to a hydrophobic pore wall. The mesopore surface is characterized by N2 and H2O sorption experiments. Those results are combined with IR spectroscopy to investigate pore wall-to-water interactions leading to different structures of water in the mesopore. Furthermore, the water's structure is studied theoretically to gain deeper insight into the interfacial interactions. For this purpose, the structure of water is analyzed by pairing densities, coordination, and angular distributions with a novel adaptation of surface-specific sum-frequency generation calculation for pore environments.}}, author = {{Weinberger, Christian and Zysk, Frederik and Hartmann, Marc and Kaliannan, Naveen and Keil, Waldemar and Kühne, Thomas and Tiemann, Michael}}, issn = {{2196-7350}}, journal = {{Advanced Materials Interfaces}}, keywords = {{Mechanical Engineering, Mechanics of Materials}}, number = {{20}}, publisher = {{Wiley}}, title = {{{The Structure of Water in Silica Mesopores – Influence of the Pore Wall Polarity}}}, doi = {{10.1002/admi.202200245}}, volume = {{9}}, year = {{2022}}, } @article{34839, abstract = {{We describe the relations among the ℓ-torsion conjecture, a conjecture of Malle giving an upper bound for the number of extensions, and the discriminant multiplicity conjecture. We prove that the latter two conjectures are equivalent in some sense. Altogether, the three conjectures are equivalent for the class of solvable groups. We then prove the ℓ-torsion conjecture for ℓ-groups and the other two conjectures for nilpotent groups.}}, author = {{Klüners, Jürgen and Wang, Jiuya}}, issn = {{0002-9939}}, journal = {{Proceedings of the American Mathematical Society}}, keywords = {{Applied Mathematics, General Mathematics}}, number = {{7}}, pages = {{2793--2805}}, publisher = {{American Mathematical Society (AMS)}}, title = {{{ℓ-torsion bounds for the class group of number fields with an ℓ-group as Galois group}}}, doi = {{10.1090/proc/15882}}, volume = {{150}}, year = {{2022}}, } @article{34835, abstract = {{We prove an upper bound for the asymptotics of counting functions of number fields with nilpotent Galois groups. }}, author = {{Klüners, Jürgen}}, issn = {{0065-1036}}, journal = {{Acta Arithmetica}}, keywords = {{Algebra and Number Theory}}, number = {{2}}, pages = {{165--184}}, publisher = {{Institute of Mathematics, Polish Academy of Sciences}}, title = {{{The asymptotics of nilpotent Galois groups}}}, doi = {{10.4064/aa211207-16-5}}, volume = {{204}}, year = {{2022}}, } @phdthesis{42762, author = {{Meyer, Sebastian}}, isbn = {{978-3-8440-8415-3}}, title = {{{Umformtechnisches Fügen von Stanzmuttern während des Formhärtens von 22MnB5}}}, year = {{2022}}, } @article{29376, abstract = {{The electrochemical properties of carbonaceous materials produced by hydrothermal carbonization, referred to as hydrochar, can be substantially improved by post-carbonization via pyrolysis. Although these materials have been widely studied for a variety of applications, the mechanisms underlying the pyrolysis are yet poorly understood. This study provides a comprehensive temperature-resolved characterization of the chemical composition, morphology and crystallinity of sucrose-derived hydrochar during pyrolysis. Thermogravimetric analysis, differential scanning calorimetry, and elemental analysis have shown that the dry hydrochar loses about 41% of its dry mass due to the exothermic disintegration of oxygen-containing groups until the carbonization is completed at about 850 °C with a total carbon yield of 93%. The carbonization and aromatization of the initially furanic and keto-aliphatic structure were analyzed by 13C solid-state nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The transition from an amorphous to a nanocrystalline graphitic structure was analyzed using X-ray diffraction and Raman spectroscopy. The pore formation mechanism was examined by helium ion microscopy, transmission electron microscopy, and nitrogen adsorption measurements. The results indicate the formation of oxygen-rich nanoclusters up to 700 °C, which decompose up to 750 °C leaving behind equally sized pores, resulting in a surface area of up to 480 m2/g.}}, author = {{Wortmann, Martin and Keil, Waldemar and Brockhagen, Bennet and Biedinger, Jan and Westphal, Michael and Weinberger, Christian and Diestelhorst, Elise and Hachmann, Wiebke and Zhao, Yanjing and Tiemann, Michael and Reiss, Günter and Hüsgen, Bruno and Schmidt, Claudia and Sattler, Klaus and Frese, Natalie}}, issn = {{0165-2370}}, journal = {{Journal of Analytical and Applied Pyrolysis}}, keywords = {{Analytical Chemistry, Fuel Technology}}, publisher = {{Elsevier BV}}, title = {{{Pyrolysis of sucrose-derived hydrochar}}}, doi = {{10.1016/j.jaap.2021.105404}}, volume = {{161}}, year = {{2022}}, } @article{28254, abstract = {{With the rapid advances of functional dielectric metasurfaces and their integration on on-chip nanophotonic devices, the necessity of metasurfaces working in different environments, especially in biological applications, arose. However, the metasurfaces’ performance is tied to the unit cell’s efficiency and ultimately the surrounding environment it was designed for, thus reducing its applicability if exposed to altering refractive index media. Here, we report a method to increase a metasurface’s versatility by covering the high-index metasurface with a low index porous SiO2 film, protecting the metasurface from environmental changes while keeping the working efficiency unchanged. We show, that a covered metasurface retains its functionality even when exposed to fluidic environments.}}, author = {{Geromel, René and Weinberger, Christian and Brormann, Katja and Tiemann, Michael and Zentgraf, Thomas}}, issn = {{2159-3930}}, journal = {{Optical Materials Express}}, number = {{1}}, pages = {{13--21}}, publisher = {{Optica}}, title = {{{Porous SiO2 coated dielectric metasurface with consistent performance independent of environmental conditions}}}, doi = {{10.1364/ome.444264}}, volume = {{12}}, year = {{2022}}, } @inproceedings{42871, author = {{Grosser, Christine and Bloh, Bea}}, editor = {{Grosser, Christine and Bloh, Bea}}, location = {{Paderborn}}, title = {{{Die Wahrnehmung lernförderlicher Faktoren digitaler Lernbegleitung während der Pandemie}}}, year = {{2022}}, } @article{34065, author = {{Kirchgässner, Wilhelm and Wallscheid, Oliver and Böcker, Joachim}}, issn = {{0952-1976}}, journal = {{Engineering Applications of Artificial Intelligence}}, publisher = {{Elsevier BV}}, title = {{{Thermal neural networks: Lumped-parameter thermal modeling with state-space machine learning}}}, doi = {{10.1016/j.engappai.2022.105537}}, volume = {{117}}, year = {{2022}}, } @inproceedings{32859, author = {{Kirchgässner, Wilhelm and Wallscheid, Oliver and Böcker, Joachim}}, booktitle = {{2022 International Power Electronics Conference (IPEC-Himeji 2022- ECCE Asia)}}, publisher = {{IEEE}}, title = {{{Learning Thermal Properties and Temperature Models of Electric Motors with Neural Ordinary Differential Equations}}}, doi = {{10.23919/ipec-himeji2022-ecce53331.2022.9807209}}, year = {{2022}}, } @misc{42948, author = {{Kuzuoglu, Muhammed Numan}}, title = {{{Der Marktplatz von Amazon - Eine wettbewerbspolitische Analyse}}}, year = {{2022}}, } @article{33453, author = {{Fuchs, Christian and Unterberger, Klaus}}, journal = {{Public Value Texte }}, number = {{25}}, pages = {{54--63}}, title = {{{Transform the Internet: Why we Need a Public Service Internet}}}, year = {{2022}}, } @article{31112, abstract = {{AbstractCoordinative challenging exercises in changing environments referred to as open-skill exercises seem to be beneficial on cognitive function. Although electroencephalographic research allows to investigate changes in cortical processing during movement, information about cortical dynamics during open-skill exercise is lacking. Therefore, the present study examines frontal brain activation during table tennis as an open-skill exercise compared to cycling exercise and a cognitive task. 21 healthy young adults conducted three blocks of table tennis, cycling and n-back task. Throughout the experiment, cortical activity was measured using 64-channel EEG system connected to a wireless amplifier. Cortical activity was analyzed calculating theta power (4–7.5 Hz) in frontocentral clusters revealed from independent component analysis. Repeated measures ANOVA was used to identify within subject differences between conditions (table tennis, cycling, n-back; p < .05). ANOVA revealed main-effects of condition on theta power in frontal (p < .01, ηp2 = 0.35) and frontocentral (p < .01, ηp2 = 0.39) brain areas. Post-hoc tests revealed increased theta power in table tennis compared to cycling in frontal brain areas (p < .05, d = 1.42). In frontocentral brain areas, theta power was significant higher in table tennis compared to cycling (p < .01, d = 1.03) and table tennis compared to the cognitive task (p < .01, d = 1.06). Increases in theta power during continuous table tennis may reflect the increased demands in perception and processing of environmental stimuli during open-skill exercise. This study provides important insights that support the beneficial effect of open-skill exercise on brain function and suggest that using open-skill exercise may serve as an intervention to induce activation of the frontal cortex.}}, author = {{Visser, Anton and Büchel, Daniel and Lehmann, Tim and Baumeister, Jochen}}, issn = {{0014-4819}}, journal = {{Experimental Brain Research}}, keywords = {{General Neuroscience}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Continuous table tennis is associated with processing in frontal brain areas: an EEG approach}}}, doi = {{10.1007/s00221-022-06366-y}}, year = {{2022}}, } @article{35624, author = {{Lehmann, Tim and Visser, Anton and Havers, Tim and Büchel, Daniel and Baumeister, Jochen}}, issn = {{1530-0315}}, journal = {{Medicine & Science in Sports & Exercise}}, keywords = {{Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine}}, number = {{9S}}, pages = {{565--565}}, publisher = {{Ovid Technologies (Wolters Kluwer Health)}}, title = {{{Surface Instability Modulates Cortical Information Processing In Multi-Joint Compound Movements}}}, doi = {{10.1249/01.mss.0000882152.12078.64}}, volume = {{54}}, year = {{2022}}, } @inproceedings{36936, author = {{Lehmann, Tim and Visser, Anton and Havers, Tim and Büchel, Daniel and Baumeister, Jochen}}, location = {{La Jolla}}, title = {{{Effects of surface instability on cortical information processing during multi- joint compound movements: an exploratory EEG study}}}, year = {{2022}}, } @inproceedings{38060, author = {{Müller, Helen Martha and Skjæret-Maroni, Nina and Vereijken, Beatrix and Baumeister, Jochen}}, location = {{Montreal}}, title = {{{Performance and Brain Activity in Older Adults while Playing Leaning and Stepping Exergames}}}, year = {{2022}}, } @inproceedings{37424, author = {{Beimdiek, Janis and Schmid, Hans-Joachim}}, keywords = {{clean air, harmful gas removal, denitrification, SCR, catalytic filtration, nanoparticles, flame-synthesis}}, location = {{Bochum}}, title = {{{A combined flue gas cleaning system with a novel entrained flow SCR using an online synthesized catalyst (Poster)}}}, year = {{2022}}, } @article{35729, author = {{Rüther, Moritz Johannes and Klippstein, Sven Helge and Ponusamy, SathishKumar and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, journal = {{Werkstoffe}}, pages = {{18 -- 19}}, publisher = {{HW-Verlag}}, title = {{{Innovative Werkstoffherstellung für das Polymer Laser Sintern – Teil 2}}}, volume = {{6}}, year = {{2022}}, } @article{35724, author = {{Rüther, Moritz Johannes and Klippstein, Sven Helge and Ponusamy, SathishKumar and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, journal = {{Werkstoffe}}, pages = {{28--29}}, publisher = {{HW-Verlag}}, title = {{{Innovative Werkstoffherstellung für das Polymer Laser Sintern – Teil 1}}}, volume = {{5}}, year = {{2022}}, }