@article{23898, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Dula, Dimitri and Hengsbach, Florian and Haase, Michael and Gierse, Jan and Zimmer, Detmar and Tröster, Thomas and Schaper, Mirko}}, issn = {{0924-0136}}, journal = {{Journal of Materials Processing Technology}}, title = {{{Soft-magnetic behavior of laser beam melted FeSi3 alloy with graded cross-section}}}, doi = {{10.1016/j.jmatprotec.2021.117183}}, year = {{2021}}, } @inproceedings{24159, abstract = {{The online fitting of a microscopic traffic simulation model to reconstruct the current state of a real traffic area can be challenging depending on the provided data. This paper presents a novel method based on limited data from sensors positioned at specific locations and guarantees a general accordance of reality and simulation in terms of multimodal road traffic counts and vehicle speeds. In these considerations, the actual purpose of research is of particular importance. Here, the research aims at improving the traffic flow by controlling the Traffic Light Systems (TLS) of the examined area which is why the current traffic state and the route choices of individual road users are the matter of interest. An integer optimization problem is derived to fit the current simulation to the latest field measurements. The concept can be transferred to any road traffic network and results in an observation of the current multimodal traffic state matching at the given sensor position. First case studies show promosing results in terms of deviations between reality and simulation.}}, author = {{Malena, Kevin and Link, Christopher and Mertin, Sven and Gausemeier, Sandra and Trächtler, Ansgar}}, booktitle = {{VEHITS 2021 Proceedings of the 7th International Conference on Vehicle Technology and Intelligent Transport Systems}}, isbn = {{978-989-758-513-5}}, keywords = {{Microscopic Traffic Simulation, Online State Estimation, Mixed Road Users, Sensor Fusion, Integer Programming, Route Choice, Vehicle2Infrastructure}}, location = {{Online Streaming}}, pages = {{386--395}}, publisher = {{SCITEPRESS}}, title = {{{Online State Estimation for Microscopic Traffic Simulations using Multiple Data Sources*}}}, volume = {{7}}, year = {{2021}}, } @article{34790, author = {{Glöckner, Helge and Willis, George A.}}, issn = {{0075-4102}}, journal = {{Journal für die reine und angewandte Mathematik}}, keywords = {{22D05, 22A05, 20E18}}, pages = {{85–103}}, title = {{{Locally pro-p contraction groups are nilpotent}}}, doi = {{10.1515/crelle-2021-0050}}, volume = {{781}}, year = {{2021}}, } @inbook{22930, abstract = {{Self-piercing riveting is an established technique for joining multi-material structures in car body manufacturing. Rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and their surface condition. To shorten the manufacturing process by omitting the heat treatment and the coating process, the authors have elaborated a concept for the use of stainless steel with high strain hardening as a rivet material. The focus of the present investigation is on the evaluation of the influences of the rivet’s geometry and material on its deformation behaviour. Conventional rivets of types P and HD2, a rivet with an improved geometry made of treatable steel 38B2, and rivets made of the stainless steels 1.3815 and 1.4541 are examined. The analysis is conducted by means of multi-step joining tests for two material combinations comprising high-strength steel HCT70X and aluminium EN AW-5083. The joints are cut to provide a cross-section and the deformation behaviour of the different rivets is analysed on the basis of the measured changes in geometry and hardness. In parallel, an examination of the force-stroke curves provides further insights. It can be demonstrated that, besides the geometry, the material strength, in particular, has a significant influence on the deformation behaviour of the rivet. The strength of steel 1.4541 is seen to be too low for the joining task, while the strength of steel 1.3815 is sufficient, and hence the investigation confirms the capability of rivets made of 1.3815 for joining even challenging material combinations.}}, author = {{Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}}, booktitle = {{Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series.}}, editor = {{Daehn, Glenn and Cao, Jian and Kinsey, Brad and Tekkaya, Erman and Vivek, Anupam and Yoshida, Yoshinori}}, keywords = {{Self-piercing riveting, Lightweight design, Deformation behaviour, Stainless steel, High nitrogen steel}}, pages = {{1495--1506}}, publisher = {{Springer}}, title = {{{Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening}}}, doi = {{10.1007/978-3-030-75381-8_124}}, year = {{2021}}, } @inproceedings{22274, abstract = {{The use of high-strength steel and aluminium is rising due to the intensified efforts being made in lightweight design, and self-piercing riveting is becoming increasingly important. Conventional rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and the coating. To shorten the manufacturing process, the use of stainless steel with high strain hardening as the rivet material represents a promising approach. This allows the coating of the rivets to be omitted due to the corrosion resistance of the material and, since the strength of the stainless steel is achieved by cold forming, heat treatment is no longer required. In addition, it is possible to adjust the local strength within the rivet. Because of that, the authors have elaborated a concept for using high nitrogen steel 1.3815 as the rivet material. The present investigation focusses on the joint strength in order to evaluate the capability of rivets in high nitrogen steel by comparison to conventional rivets made of treatable steel. Due to certain challenges in the forming process of the high nitrogen steel rivets, deviations result from the targeted rivet geometry. Mainly these deviations cause a lower joint strength with these rivets, which is, however, adequate. All in all, the capability of the new rivet is proven by the results of this investigation. }}, author = {{Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}}, keywords = {{Self-piercing Riveting, Joining Technology, Rivet Geometry, Rivet Material, High Nitrogen Steel, Joint Strength}}, location = {{Liège, Belgien}}, title = {{{Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel}}}, doi = {{10.25518/esaform21.1911}}, year = {{2021}}, } @article{22272, abstract = {{The number of multi-material joints is increasing as a result of lightweight design. Self-piercing riveting (SPR) is an important mechanical joining technique for multi-material structures. Rivets for SPR are coated to prevent corrosion, but this coating also influences the friction that prevails during the joining process. The aim of the present investigation is to evaluate this influence. The investigation focuses on the common rivet coatings Almac® and zinc-nickel with topcoat as well as on uncoated rivet surfaces. First of all, the coating thickness and the uniformity of the coating distribution are analysed. Friction tests facilitate the classification of the surface properties. The influence of the friction on the characteristic joint parameters and the force-stroke curves is analysed by means of experimental joining tests. More in-depth knowledge of the effects that occur is achieved through the use of numerical simulation. Overall, it is shown that the surface condition of the rivet has an impact on the friction during the joining process and on the resulting joint. However, the detected deviations between different surface conditions do not restrict the operational capability of SPR and the properties of uncoated rivet surfaces, in particular, are similar to those of Almac®-coated rivets. It can thus be assumed that SPR with respect to the joining process is also possible without rivet coating in principle.}}, author = {{Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}}, journal = {{Key Engineering Materials}}, keywords = {{Coating, Friction, Joining}}, pages = {{11--18}}, title = {{{Influence of the Rivet Coating on the Friction during Self-Piercing Riveting}}}, doi = {{10.4028/www.scientific.net/KEM.883.11}}, volume = {{883}}, year = {{2021}}, } @inbook{35520, abstract = {{Auch in der Lehrkräftebildung in der Domäne Physik ist es Ziel, im Studium vermittelte, theoretische Kenntnisse mit berufspraktischen Anforderungen von angehenden Lehrkräften in Beziehung zu setzen. Charakteristisch für das Fach ist dabei zum einen eine eher anwendungsorientierte theoretische Position zum Zusammenhang von Theorie und Praxis. Zum anderen zeichnet es sich auch durch eine Art experimentelle Orientierung aus, die die Relationierung beider Aspekte als empirisch zu klärende Herausforderung begreift. In diesem Beitrag wird daher zunächst ein kurzer Überblick über Modelle und empirische Forschungen zum Zusammenhang zwischen theoretischem Wissen und praktischem Lehrkräftehandeln gegeben, die das Verständnis der Relationierung von Theorie und Praxis in der Didaktik der Physik prägen. Anschließend werden typische Lehr-Lern-Formate beschrieben und dabei auch jeweils die Ergebnisse begleitender Wirksamkeitsevaluationen kurz dargestellt.}}, author = {{Vogelsang, Christoph and Rehfeldt, Daniel}}, booktitle = {{Edition Fachdidaktiken}}, isbn = {{9783658325671}}, issn = {{2524-8677}}, pages = {{333--348}}, publisher = {{Springer Fachmedien Wiesbaden}}, title = {{{Relationierung von Theorie und Praxis in der Lehrkräftebildung im Fach Physik – eine Übersicht über Forschungen und Formate}}}, doi = {{10.1007/978-3-658-32568-8_19}}, year = {{2021}}, } @article{45177, author = {{Kulgemeyer, Christoph and Kempin, Maren and Weißbach, Anna and Borowski, Andreas and Buschhüter, David and Enkrott, Patrick and Reinhold, Peter and Riese, Josef and Schecker, Horst and Schröder, Jan and Vogelsang, Christoph}}, issn = {{0950-0693}}, journal = {{International Journal of Science Education}}, keywords = {{Education}}, number = {{18}}, pages = {{3035--3057}}, publisher = {{Informa UK Limited}}, title = {{{Exploring the impact of pre-service science teachers’ reflection skills on the development of professional knowledge during a field experience}}}, doi = {{10.1080/09500693.2021.2006820}}, volume = {{43}}, year = {{2021}}, } @article{62773, abstract = {{AbstractA gradient‐enhanced damage model is combined with finite viscoelasticity and implemented in an Abaqus user subroutine, exploiting the heat equation solution capabilities for the damage regularisation, in order to simulate soft polymers. This regularised damage approach provides the advantage of mesh independent results and avoids localisation effects. In this work, a self‐diagnostic poly(dimethylsiloxane) (PDMS) elastomer is chosen as an example. To this end, an efficient two‐step parameter identification framework is developed to calibrate the corresponding model parameters.}}, author = {{Schulte, Robin and Ostwald, Richard and Menzel, Andreas}}, issn = {{1617-7061}}, journal = {{PAMM}}, number = {{1}}, publisher = {{Wiley}}, title = {{{A computational framework for gradient‐enhanced damage – implementation and applications}}}, doi = {{10.1002/pamm.202000215}}, volume = {{20}}, year = {{2021}}, } @article{62772, author = {{Schowtjak, Alexander and Schulte, Robin and Clausmeyer, Till and Ostwald, Richard and Tekkaya, A. Erman and Menzel, Andreas}}, issn = {{0020-7403}}, journal = {{International Journal of Mechanical Sciences}}, publisher = {{Elsevier BV}}, title = {{{ADAPT — A Diversely Applicable Parameter Identification Tool: Overview and full-field application examples}}}, doi = {{10.1016/j.ijmecsci.2021.106840}}, volume = {{213}}, year = {{2021}}, } @article{62803, abstract = {{The aim to produce highly active, selective, and long-lived electrocatalysts by design drives major research efforts toward gaining fundamental understanding of the relationship between material properties and their catalytic performance. Surface characterization tools enable to assess atomic scale information on the complexity of electrocatalyst materials. Advancing electrochemical methodologies to adequately characterize such systems was less of a research focus point. In this Review, we shed light on the ability to gain fundamental insights into electrocatalysis from a complementary perspective and establish corresponding design strategies. These may rely on adopting the perceptions and models of other subareas of electrochemistry, such as corrosion, battery research, or electrodeposition. Concepts on how to account for and improve mass transport, manage gas bubble release, or exploit magnetic fields are highlighted in this respect. Particular attention is paid to deriving design strategies for nanoelectrocatalysts, which is often impeded, as structural and physical material properties are buried in electrochemical data of whole electrodes or even devices. Thus, a second major approach focuses on overcoming this difference in the considered level of complexity by methods of single-entity electrochemistry. The gained understanding of intrinsic catalyst performance may allow to rationally advance design concepts with increased complexity, such as three-dimensional electrode architectures. Many materials undergo structural changes upon formation of the working catalyst. Accordingly, developing “precatalysts” with low hindrance of the electrochemical transformation to the active catalyst is suggested as a final design strategy.}}, author = {{Linnemann, Julia and Kanokkanchana, Kannasoot and Tschulik, Kristina}}, issn = {{2155-5435}}, journal = {{ACS Catalysis}}, keywords = {{electrocatalysis}}, number = {{9}}, pages = {{5318--5346}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Design Strategies for Electrocatalysts from an Electrochemist’s Perspective}}}, doi = {{10.1021/acscatal.0c04118}}, volume = {{11}}, year = {{2021}}, } @article{62806, abstract = {{The electrical double‐layer plays a key role in important interfacial electrochemical processes from catalysis to energy storage and corrosion. Therefore, understanding its structure is crucial for the progress of sustainable technologies. We extract new physico‐chemical information on the capacitance and structure of the electrical double‐layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order‐of‐magnitude than predicted by the traditional mean‐field models of the double‐layer such as the Gouy–Chapman–Stern model. Performing molecular dynamics simulations, we investigate the possible relationship between the measured high capacitance and adsorption strength of the water adlayer formed at the metal surface. These insights may launch the active tuning of solid–solvent and solvent–solvent interactions as an innovative design strategy to transform energy technologies towards superior performance and sustainability.}}, author = {{Azimzadeh Sani, Mahnaz and Pavlopoulos, Nicholas G. and Pezzotti, Simone and Serva, Alessandra and Cignoni, Paolo and Linnemann, Julia and Salanne, Mathieu and Gaigeot, Marie‐Pierre and Tschulik, Kristina}}, issn = {{1433-7851}}, journal = {{Angewandte Chemie International Edition}}, keywords = {{single-entity electrochemistry, electrical double layer, supercapacitor, nanoparticles}}, number = {{5}}, publisher = {{Wiley}}, title = {{{Unexpectedly High Capacitance of the Metal Nanoparticle/Water Interface: Molecular‐Level Insights into the Electrical Double Layer}}}, doi = {{10.1002/anie.202112679}}, volume = {{61}}, year = {{2021}}, } @article{62805, abstract = {{Single-entity electrochemistry allows for assessing electrocatalytic activities of individual material entities such as nanoparticles (NPs). Thus, it becomes possible to consider intrinsic electrochemical properties of nanocatalysts when researching how activity relates to physical and structural material properties. Conversely, conventional electrochemical techniques provide a normalized sum current referring to a huge ensemble of NPs constituting, along with additives (e.g., binders), a complete catalyst-coated electrode. Accordingly, recording electrocatalytic responses of single NPs avoids interferences of ensemble effects and reduces the complexity of electrocatalytic processes, thus enabling detailed description and modelling. Herein, we present insights into the oxygen evolution catalysis at individual cubic Co3O4 NPs impacting microelectrodes of different support materials. Simulating diffusion at supported nanocubes, measured step current signals can be analyzed, providing edge lengths, corresponding size distributions, and interference-free turnover frequencies. The provided nano-impact investigation of (electro-)catalyst-support effects contradicts assumptions on a low number of highly active sites.}}, author = {{Liu, Zhibin and Corva, Manuel and Amin, Hatem M. A. and Blanc, Niclas and Linnemann, Julia and Tschulik, Kristina}}, issn = {{1422-0067}}, journal = {{International Journal of Molecular Sciences}}, keywords = {{electrocatalysis, oxygen evolution reaction, cobalt spinel, single-entity electrochemistry}}, number = {{23}}, publisher = {{MDPI AG}}, title = {{{Single Co3O4 Nanocubes Electrocatalyzing the Oxygen Evolution Reaction: Nano-Impact Insights into Intrinsic Activity and Support Effects}}}, doi = {{10.3390/ijms222313137}}, volume = {{22}}, year = {{2021}}, } @inbook{27071, author = {{Pollmeier, Pascal and Fechner, Sabine}}, booktitle = {{Theorie und Praxis in der Lehrerbildung - Verhältnisbestimmungen aus der Perspektive von Fachdidaktiken}}, editor = {{Caruso, Carina and Harteis, Christian and Gröschner, Alexander}}, issn = {{2524-8677}}, publisher = {{Springer Fachmedien}}, title = {{{Zwischen den Stühlen? – Verknüpfung von Erfahrungen des Praxissemesters mit Theorien im Lehramtsstudium Chemie. Sukzessiven Kompetenzaufbau nach dem Praxissemester gestalten}}}, doi = {{10.1007/978-3-658-32568-8_16}}, year = {{2021}}, } @inbook{24935, author = {{Bauer, Anna and Sacher, Marc and Habig, Sebastian and Fechner, Sabine}}, booktitle = {{Hochschule auf Abstand. Ein multiperspektivischer Zugang zur digitalen Lehre}}, editor = {{Neiske, Iris and Osthushenrich, Judith and Schaper, Niclas and Trier, Ulrike and Vöing, Nerea}}, pages = {{155--168}}, publisher = {{ transcript Verlag}}, title = {{{Laborpraktika auf Distanz. Ansätze in den Naturwissenschaften}}}, doi = {{DOI: 10.14361/9783839456903-011}}, volume = {{3}}, year = {{2021}}, } @article{62851, abstract = {{To reduce high-level radiotoxic waste generated by nuclear power plants, highly selective separation agents for minor actinides are mandatory. The mixed N,O-donor ligand N,N,N′,N′-tetrakis[(6-carboxypyridin-2-yl)methyl]ethylenediamine (H4TPAEN; 1) has shown good performance as a masking agent in Am3+/Eu3+ separation studies. Adjustments on the pyridyl backbone to raise the hydrophilicity led to a decrease in selectivity and a decrease in M3+–Nam interactions. An enhanced basicity of the pyridyl N-donors was given as a cause. In this work, we examine whether a decrease in O-donor basicity can promote the M3+–Nam interactions. Therefore, we replace the deprotonated “charged” carboxylic acid groups of TPAEN4– by neutral amide groups and introduce N,N,N′,N’-tetrakis[(6-N″,N′′-diethylcarbamoylpyridin-2-yl)methyl]ethylenediamine (TPAMEN; 2) as a new ligand. TPAMEN was crystallized with Eu(OTf)3 and Eu(NO3)3·6H2O to form positively charged 1:1 [Eu(TPAMEN)]3+ complexes in the solid state. Alterations in the M–O/N bond distances are compared to [Eu(TPAEN)]− and investigated by DFT calculations to expose the differences in charge/energy density distributions at europium(III) and the donor functionalities of the TPAEN4– and TPAMEN. On the basis of estimations of the bond orders, atomic charges spin populations, and density of states in the Eu and potential Am and Cm complexes, the specific contributions of the donor–metal interaction are analyzed. The prediction of complex formation energy differences for the [M(TPAEN)]− and [M(TPAMEN)]3+ (M3+ = Eu3+, Am3+) complexes provide an outlook on the potential performance of TPAMEN in Am3+/Eu3+ separation.}}, author = {{Schnaars, Kathleen and Kaneko, Masashi and Fujisawa, Kiyoshi}}, issn = {{0020-1669}}, journal = {{Inorganic Chemistry}}, number = {{4}}, pages = {{2477--2491}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Effect of Oxygen-Donor Charge on Adjacent Nitrogen-Donor Interactions in Eu3+ Complexes of Mixed N,O-Donor Ligands Demonstrated on a 10-Fold [Eu(TPAMEN)]3+ Chelate Complex}}}, doi = {{10.1021/acs.inorgchem.0c03405}}, volume = {{60}}, year = {{2021}}, } @article{59168, abstract = {{Entrepreneurial experience alone may not necessarily guarantee venture success. Some entrepreneurs develop into experts through learning from their experiences, whereas others fail to do so. To explain the missing link between experience and expertise, we introduce a social-cognitive model of self-regulated entrepreneurial learning (SREL) to demonstrate how entrepreneurial expertise can be systematically developed to increase the probability of entrepreneurial success. We identify key self-regulatory learning processes essential to entrepreneurial learning by developing propositions and related practice-oriented applications of the SREL model for entrepreneurs.}}, author = {{Winkler, Christoph and Fust, Alexander and Jenert, Tobias}}, issn = {{0047-2778}}, journal = {{Journal of Small Business Management}}, number = {{4}}, pages = {{2071--2096}}, publisher = {{Informa UK Limited}}, title = {{{From entrepreneurial experience to expertise: A self-regulated learning perspective}}}, doi = {{10.1080/00472778.2021.1883041}}, volume = {{61}}, year = {{2021}}, } @article{63176, author = {{Taranto, E and Jablonski, S and Recio, T and Mercat, C and Cunha, E and Lázaro, C and Ludwig, M and Mammana, MF}}, issn = {{2227-7390}}, number = {{22}}, title = {{{Professional Development in Mathematics Education-Evaluation of a MOOC on Outdoor Mathematics}}}, volume = {{9}}, year = {{2021}}, } @article{63173, author = {{Barlovits, S and Jablonski, S and Lázaro, C and Ludwig, M and Recio, T}}, issn = {{2227-7102}}, number = {{8}}, title = {{{Teaching from a Distance-Math Lessons during COVID-19 in Germany and Spain}}}, volume = {{11}}, year = {{2021}}, } @article{63236, abstract = {{The response of the quartz crystal microbalance (QCM, also: QCM-D for “QCM with Dissipation monitoring”) to loading with a diverse set of samples is reviewed in a consistent frame. After a brief introduction to the advanced QCMs, the governing equation (the small-load approximation) is derived. Planar films and adsorbates are modeled based on the acoustic multilayer formalism. In liquid environments, viscoelastic spectroscopy and high-frequency rheology are possible, even on layers with a thickness in the monolayer range. For particulate samples, the contact stiffness can be derived. Because the stress at the contact is large, the force is not always proportional to the displacement. Nonlinear effects are observed, leading to a dependence of the resonance frequency and the resonance bandwidth on the amplitude of oscillation. Partial slip, in particular, can be studied in detail. Advanced topics include structured samples and the extension of the small-load approximation to its tensorial version.}}, author = {{Johannsmann, Diethelm and Langhoff, Arne and Leppin, Christian}}, issn = {{1424-8220}}, journal = {{Sensors}}, number = {{10}}, publisher = {{MDPI AG}}, title = {{{Studying Soft Interfaces with Shear Waves: Principles and Applications of the Quartz Crystal Microbalance (QCM)}}}, doi = {{10.3390/s21103490}}, volume = {{21}}, year = {{2021}}, }