@inproceedings{45407, author = {{Große-Heilmann, Rike Isabel and Burde, Jan-Philipp and Riese, Josef and Schubatzky, Thomas and Weiler, David}}, booktitle = {{PhyDid B-Didaktik der Physik-Beiträge zur DPG-Frühjahrstagung 2021}}, pages = {{171--178}}, title = {{{Erwerb und Messung physikdidaktischer Kompetenzen zum Einsatz digitaler Medien}}}, year = {{2021}}, } @inproceedings{45408, author = {{Weiler, David and Burde, Jan-Philipp and Große-Heilmann, Rike Isabel and Lachner, Andreas and Riese, Josef and Schubatzky, Thomas}}, booktitle = {{PhyDid B-Didaktik der Physik-Beiträge zur DPG-Frühjahrstagung 2021}}, pages = {{209--216}}, title = {{{Entwicklung eines Seminars zur Förderung des Konzeptverständnisses mittels digitaler Medien}}}, year = {{2021}}, } @inbook{45436, author = {{Haghani Fazl, Mohammad}}, booktitle = {{Impeccability and Temptation: Understanding Christ's Divine and Human Will}}, editor = {{Grössl, Johannes and von Stosch, Klaus}}, pages = {{235--252}}, publisher = {{Routledge Verlag}}, title = {{{The Scope of ‘iṣma and Qur’anic Evidence}}}, year = {{2021}}, } @article{41511, author = {{Hein, Maxwell and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0933-5137}}, journal = {{Materialwissenschaft und Werkstofftechnik}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}}, number = {{7}}, pages = {{703--716}}, publisher = {{Wiley}}, title = {{{Additively processed TiAl6Nb7 alloy for biomedical applications}}}, doi = {{10.1002/mawe.202000288}}, volume = {{52}}, year = {{2021}}, } @article{41507, abstract = {{ Purpose The currently existing restrictions regarding the deployment of additively manufactured components because of poor surface roughness, porosity and residual stresses as well as their influence on the low-cycle fatigue (LCF) strength are addressed in this paper. Design/methodology/approach This study aims to evaluating the effect of different pre- and post-treatments on the LCF strength of additively manufactured 316L parts. Therefore, 316L specimens manufactured by laser powder bed fusion were examined in their as-built state as well as after grinding, or coating with regard to the surface roughness, residual stresses and LCF strength. To differentiate between topographical effects and residual stress-related phenomena, stress-relieved 316L specimens served as a reference throughout the investigations. To enable an alumina coating of the 316L components, atmospheric plasma spraying was used, and the near-surface residual stresses and the surface roughness are measured and investigated. Findings The results have shown that the applied pre- and post-treatments such as stress-relief heat treatment, grinding and alumina coating have each led to an increase in LCF strength of the 316L specimens. In contrast, the non-heat-treated specimens predominantly exhibited coating delamination. Originality/value To the best of the authors’ knowledge, this is the first study of the correlation between the LCF behavior of additively manufactured uncoated 316L specimens in comparison with additively manufactured 316L specimens with an alumina coating. }}, author = {{Garthe, Kai-Uwe and Hoyer, Kay-Peter and Hagen, Leif and Tillmann, Wolfgang and Schaper, Mirko}}, issn = {{1355-2546}}, journal = {{Rapid Prototyping Journal}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}}, number = {{5}}, pages = {{833--840}}, publisher = {{Emerald}}, title = {{{Correlation between pre- and post-treatments of additively manufactured 316L parts and the resulting low cycle fatigue behavior}}}, doi = {{10.1108/rpj-01-2021-0017}}, volume = {{28}}, year = {{2021}}, } @article{41506, abstract = {{Processing aluminum alloys employing powder bed fusion of metals (PBF-LB/M) is becoming more attractive for the industry, especially if lightweight applications are needed. Unfortunately, high-strength aluminum alloys such as AA7075 are prone to hot cracking during PBF-LB/M, as well as welding. Both a large solidification range promoted by the alloying elements zinc and copper and a high thermal gradient accompanied with the manufacturing process conditions lead to or favor hot cracking. In the present study, a simple method for modifying the powder surface with titanium carbide nanoparticles (NPs) as a nucleating agent is aimed. The effect on the microstructure with different amounts of the nucleating agent is shown. For the aluminum alloy 7075 with 2.5 ma% titanium carbide nanoparticles, manufactured via PBF-LB/M, crack-free samples with a refined microstructure having no discernible melt pool boundaries and columnar grains are observed. After using a two-step ageing heat treatment, ultimate tensile strengths up to 465 MPa and an 8.9% elongation at break are achieved. Furthermore, it is demonstrated that not all nanoparticles used remain in the melt pool during PBF-LB/M.}}, author = {{Heiland, Steffen and Milkereit, Benjamin and Hoyer, Kay-Peter and Zhuravlev, Evgeny and Kessler, Olaf and Schaper, Mirko}}, issn = {{1996-1944}}, journal = {{Materials}}, keywords = {{General Materials Science}}, number = {{23}}, publisher = {{MDPI AG}}, title = {{{Requirements for Processing High-Strength AlZnMgCu Alloys with PBF-LB/M to Achieve Crack-Free and Dense Parts}}}, doi = {{10.3390/ma14237190}}, volume = {{14}}, year = {{2021}}, } @article{24790, abstract = {{Implants often overtake body function just for a certain time and remain as an unnecessary foreign body or have to be removed. Thus, resorbable implants are highly beneficial to reduce patient burden. Besides established materials, Iron-(Fe)-based alloys are in focus due to superior mechanical properties and good biocompatibility. However, their degradation rate needs to be increased. Phases with high electrochemical potential could promote the dissolution of residual material based on the galvanic coupling. Silver (Ag) is promising due to its high electrochemical potential (+0.8 V vs. SHE), immiscibility with Fe, biocompatibility, and anti-bacterial properties. But to prevent adverse consequences the Ag-particles, remaining after dissolution of the matrix, need to dissolve. Thus, a bioresorbable Ag-alloy is required. Regarding the electrochemical potential and degradation behavior of binary alloys, Cerium (Ce) and Lanthanum (La) are well-suited considering their biocompatibility and antibacterial behavior. Accordingly, this research addresses AgCe and AgCeLa alloys as additives for Fe-based materials with adapted degradation behavior. Furthermore, degradable Ag-alloys combined with inert implant materials could enable the controlled release of antibacterial active Ag-ions.}}, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0167-577X}}, journal = {{Materials Letters}}, title = {{{Bioresorbable AgCe and AgCeLa alloys for adapted Fe-based implants}}}, doi = {{10.1016/j.matlet.2021.130890}}, volume = {{306}}, year = {{2021}}, } @article{41516, author = {{Tillmann, Wolfgang and Lopes Dias, Nelson Filipe and Franke, Carlo and Kokalj, David and Stangier, Dominic and Filor, Viviane and Mateus-Vargas, Rafael Hernán and Oltmanns, Hilke and Kietzmann, Manfred and Meißner, Jessica and Hein, Maxwell and Pramanik, Sudipta and Hoyer, Kay-Peter and Schaper, Mirko and Nienhaus, Alexander and Thomann, Carl Arne and Debus, Jörg}}, issn = {{0257-8972}}, journal = {{Surface and Coatings Technology}}, keywords = {{Materials Chemistry, Surfaces, Coatings and Films, Surfaces and Interfaces, Condensed Matter Physics, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Tribo-mechanical properties and biocompatibility of Ag-containing amorphous carbon films deposited onto Ti6Al4V}}}, doi = {{10.1016/j.surfcoat.2021.127384}}, volume = {{421}}, year = {{2021}}, } @article{41512, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Dula, Dimitri and Hengsbach, Florian and Grydin, Olexandr and Frolov, Yaroslav and Schaper, Mirko}}, issn = {{0921-5093}}, journal = {{Materials Science and Engineering: A}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}}, publisher = {{Elsevier BV}}, title = {{{Laser beam melting of functionally graded materials with application-adapted tailoring of magnetic and mechanical performance}}}, doi = {{10.1016/j.msea.2021.141662}}, volume = {{822}}, year = {{2021}}, } @article{41510, author = {{Pramanik, Sudipta and Andreiev, Anatolii and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0142-1123}}, journal = {{International Journal of Fatigue}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering, Mechanics of Materials, General Materials Science, Modeling and Simulation}}, publisher = {{Elsevier BV}}, title = {{{Quasi in-situ analysis of fracture path during cyclic loading of double-edged U notched additively manufactured FeCo alloy}}}, doi = {{10.1016/j.ijfatigue.2021.106498}}, volume = {{153}}, year = {{2021}}, } @article{41509, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0167-577X}}, journal = {{Materials Letters}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}}, publisher = {{Elsevier BV}}, title = {{{Bioresorbable AgCe and AgCeLa alloys for adapted Fe-based implants}}}, doi = {{10.1016/j.matlet.2021.130890}}, volume = {{306}}, year = {{2021}}, } @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}}, } @article{41517, abstract = {{AbstractWithin this research, the multiscale microstructural evolution before and after the tensile test of a FeCo alloy is addressed. X-ray µ-computer tomography (CT), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM) are employed to determine the microstructure on different length scales. Microstructural evolution is studied by performing EBSD of the same area before and after the tensile test. As a result, $$\langle$$ 001$$\rangle$$ ||TD, $$\langle$$ 011$$\rangle$$ ||TD are hard orientations and $$\langle$$ 111$$\rangle$$ ||TD is soft orientations for deformation accommodation. It is not possible to predict the deformation of a single grain with the Taylor model. However, the Taylor model accurately predicts the orientation of all grains after deformation. {123}$$\langle$$ 111$$\rangle$$ is the most active slip system, and {112}$$\langle$$ 111$$\rangle$$ is the least active slip system. Both EBSD micrographs show grain subdivision after tensile testing. TEM images show the formation of dislocation cells. Correlative HRTEM images show unresolved lattice fringes at dislocation cell boundaries, whereas resolved lattice fringes are observed at dislocation cell interior. Since Schmid’s law is unable to predict the deformation behavior of grains, the boundary slip transmission accurately predicts the grain deformation behavior.}}, author = {{Pramanik, Sudipta and Tasche, Lennart and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{1059-9495}}, journal = {{Journal of Materials Engineering and Performance}}, keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}}, number = {{11}}, pages = {{8048--8056}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Correlation between Taylor Model Prediction and Transmission Electron Microscopy-Based Microstructural Investigations of Quasi-In Situ Tensile Deformation of Additively Manufactured FeCo Alloy}}}, doi = {{10.1007/s11665-021-06065-9}}, volume = {{30}}, year = {{2021}}, } @article{24243, abstract = {{The addition of Ag to amorphous carbon (a-C) films is highly effective in tailoring the tribo-mechanical properties and biocompatibility. For biomedical applications, Ag-containing a-C (a-C:Ag) represents a promising film material for improving the biofunctional surface properties of Ti-based alloys. In a sputtering process, a-C:Ag films, with Ag contents up to 7.5 at.%, were deposited with a chemically graded TixCy interlayer onto Ti6Al4V. The tribo-mechanical and biocompatible properties of a-C:Ag were evaluated. The influence of the Ag content on these properties was analyzed and compared to those of uncoated Ti6Al4V. Raman spectroscopy reveals that the amount of incorporated Ag does not induce significant structural changes in the disordered network, only a reduced number of vacancies and sp3-coordinated C bonds within the sp2-dominant a-C network is assigned to the films with high Ag concentration. With increasing Ag content, stresses, hardness, and elastic modulus decrease from (2.02 ± 0.07) to (1.15 ± 0.03) GPa, from (17.4 ± 1.5) to (13.4 ± 0.9) GPa, and from (171.8 ± 8.1) to (138.5 ± 5.8) GPa, respectively. In tribometer tests, the friction behavior against Al2O3 in lubricated condition with a simulated-body-fluid-based lubricant is not affected by the Ag concentration, but the Al2O3 counterpart wear is reduced for all a-C:Ag films compared to a-C. The friction against ultra-high-molecular-weight polyethylene (UHMWPE) decreases continuously with increasing Ag concentration and the counterpart wear is lower at higher Ag contents. Compared to a-C:Ag, Ti6Al4V demonstrates lower friction against UHMWPE and higher friction against Al2O3. The a-C:Ag films are not exposed to abrasion by Al2O3 or pronounced material transfer of UHMWPE. The hardness difference and chemical affinity between the friction partners are decisive for the tribological behavior of a-C:Ag. Compared to Ti6Al4V, the a-C:Ag films show antibacterial activity against Staphylococcus aureus, while the proliferation of osteoblast-like cells is reduced by Ag.}}, author = {{Tillmann, Wolfgang and Lopes Dias, Nelson Filipe and Franke, Carlo and Kokalj, David and Stangier, Dominic and Filor, Viviane and Mateus-Vargas, Rafael Hernán and Oltmanns, Hilke and Kietzmann, Manfred and Meißner, Jessica and Hein, Maxwell and Pramanik, Sudipta and Hoyer, Kay-Peter and Schaper, Mirko and Nienhaus, Alexander and Thomann, Carl Arne and Debus, Jörg}}, issn = {{0257-8972}}, journal = {{Surface and Coatings Technology}}, title = {{{Tribo-mechanical properties and biocompatibility of Ag-containing amorphous carbon films deposited onto Ti6Al4V}}}, doi = {{10.1016/j.surfcoat.2021.127384}}, year = {{2021}}, } @article{29815, abstract = {{Aluminium steel clad materials have high potential for industrial applications. Their mechanical properties are governed by an intermetallic layer, which forms upon heat treatment at the Al-Fe interface. Transmission electron microscopy was employed to identify the phases present at the interface by selective area electron diffraction and energy dispersive spectroscopy. Three phases were identified: orthorhombic Al5Fe2, monoclinic Al13Fe4 and cubic Al19Fe4MnSi2. An effective interdiffusion coefficient dependent on concentration was determined according to the Boltzmann–Matano method. The highest value of the interdiffusion coefficient was reached at the composition of the intermetallic phases. Afterwards, the process of diffusion considering the evaluated interdiffusion coefficient was simulated using the finite element method. Results of the simulations revealed that growth of the intermetallic phases proceeds preferentially in the direction of aluminium.}}, author = {{Křivská, Barbora and Šlapáková, Michaela and Veselý, Jozef and Kihoulou, Martin and Fekete, Klaudia and Minárik, Peter and Králík, Rostislav and Grydin, Olexandr and Stolbchenko, Mykhailo and Schaper, Mirko}}, issn = {{1996-1944}}, journal = {{Materials}}, keywords = {{General Materials Science}}, number = {{24}}, publisher = {{MDPI AG}}, title = {{{Intermetallic Phases Identification and Diffusion Simulation in Twin-Roll Cast Al-Fe Clad Sheet}}}, doi = {{10.3390/ma14247771}}, volume = {{14}}, year = {{2021}}, } @article{24086, abstract = {{Laser beam melting (LBM) is an advanced manufacturing technology providing special features and the possibility to produce complex and individual parts directly from a CAD model. TiAl6V4 is the most common used titanium alloy particularly in biomedical applications. TiAl6Nb7 shows promising improvements especially regarding biocompatible properties due to the substitution of the hazardous vanadium. This work focuses on the examination of laser beam melted TiAl6Nb7. For microstructural investigation scanning electron microscopy including energydispersive x-ray spectroscopy as well as electron backscatter diffraction are utilized. The laser beam melted related acicular microstructure as well as the corresponding mechanical properties, which are determined by hardness measurements and tensile tests, are investigated. The laser beam melted alloy meets, except of breaking elongation A, the mechanical demands like ultimate tensile strength Rm, yield strength Rp0.2, Vickers hardness HV of international standard ISO 5832-11. Next steps contain comparison between TiAl6Nb7 and TiAl6V4 in different conditions. Further investigations aim at improving mechanical properties of TiAl6Nb7 by heat treatments and assessment of their influence on the microstructure as well as examination regarding the corrosive behavior in human bodylike conditions.}}, author = {{Hein, Maxwell and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0933-5137}}, journal = {{Materialwissenschaft und Werkstofftechnik}}, keywords = {{Laser beam melting, titanium alloy, TiAl6Nb7, biomedical engineering, implants}}, pages = {{703--716}}, title = {{{Additively processed TiAl6Nb7 alloy for biomedical applications}}}, doi = {{10.1002/mawe.202000288}}, volume = {{52}}, year = {{2021}}, } @article{29813, author = {{Cieslar, Miroslav and Králík, Rostislav and Bajtošová, Lucia and Křivská, Barbora and Hájek, Michal and Belejová, Sára and Grydin, Olexandr and Stolbchenko, Mykhailo and Schaper, Mirko}}, issn = {{1431-9276}}, journal = {{Microscopy and Microanalysis}}, keywords = {{Instrumentation}}, number = {{S2}}, pages = {{79--80}}, publisher = {{Cambridge University Press (CUP)}}, title = {{{High Temperature Annealing of Twin-Roll Cast Al-Li-Based Alloy Studied by In-situ SEM and STEM}}}, doi = {{10.1017/s1431927621013398}}, volume = {{27}}, year = {{2021}}, } @article{41514, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Filor, Viviane and Pramanik, Sudipta and Kietzmann, Manfred and Meißner, Jessica and Schaper, Mirko}}, issn = {{0925-8388}}, journal = {{Journal of Alloys and Compounds}}, keywords = {{Materials Chemistry, Metals and Alloys, Mechanical Engineering, Mechanics of Materials}}, publisher = {{Elsevier BV}}, title = {{{Novel AgCa and AgCaLa alloys for Fe-based bioresorbable implants with adapted degradation}}}, doi = {{10.1016/j.jallcom.2021.159544}}, volume = {{871}}, year = {{2021}}, } @article{29814, author = {{Křivská, Barbora and Šlapáková, Michaela and Minárik, Peter and Fekete, Klaudia and Králík, Rostislav and Stolbchenko, Mykhailo and Schaper, Mirko and Grydin, Olexandr}}, issn = {{1431-9276}}, journal = {{Microscopy and Microanalysis}}, keywords = {{Instrumentation}}, number = {{S2}}, pages = {{91--92}}, publisher = {{Cambridge University Press (CUP)}}, title = {{{Intermetallic Phase Growth in Al-steel Clad Strip during In-situ Heating in TEM}}}, doi = {{10.1017/s1431927621013453}}, volume = {{27}}, year = {{2021}}, } @article{41515, author = {{Pramanik, Sudipta and Tasche, Lennart and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{2214-8604}}, journal = {{Additive Manufacturing}}, keywords = {{Industrial and Manufacturing Engineering, Engineering (miscellaneous), General Materials Science, Biomedical Engineering}}, publisher = {{Elsevier BV}}, title = {{{Investigating the microstructure of an additively manufactured FeCo alloy: an electron microscopy study}}}, doi = {{10.1016/j.addma.2021.102087}}, volume = {{46}}, year = {{2021}}, } @article{27700, author = {{Camberg, Alan Adam and Andreiev, Anatolii and Pramanik, Sudipta and Hoyer, Kay-Peter and Tröster, Thomas and Schaper, Mirko}}, issn = {{0921-5093}}, journal = {{Materials Science and Engineering: A}}, publisher = {{Elsevier}}, title = {{{Strength enhancement of AlMg sheet metal parts by rapid heating and subsequent cold die stamping of severely cold-rolled blanks}}}, doi = {{10.1016/j.msea.2021.142312}}, year = {{2021}}, } @article{24090, abstract = {{AbstractWithin this research, the multiscale microstructural evolution before and after the tensile test of a FeCo alloy is addressed. X-ray µ-computer tomography (CT), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM) are employed to determine the microstructure on different length scales. Microstructural evolution is studied by performing EBSD of the same area before and after the tensile test. As a result, $$\langle$$ 001$$\rangle$$ ||TD, $$\langle$$ 011$$\rangle$$ ||TD are hard orientations and $$\langle$$ 111$$\rangle$$ ||TD is soft orientations for deformation accommodation. It is not possible to predict the deformation of a single grain with the Taylor model. However, the Taylor model accurately predicts the orientation of all grains after deformation. {123}$$\langle$$ 111$$\rangle$$ is the most active slip system, and {112}$$\langle$$ 111$$\rangle$$ is the least active slip system. Both EBSD micrographs show grain subdivision after tensile testing. TEM images show the formation of dislocation cells. Correlative HRTEM images show unresolved lattice fringes at dislocation cell boundaries, whereas resolved lattice fringes are observed at dislocation cell interior. Since Schmid’s law is unable to predict the deformation behavior of grains, the boundary slip transmission accurately predicts the grain deformation behavior.}}, author = {{Pramanik, Sudipta and Tasche, Lennart and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{1059-9495}}, journal = {{Journal of Materials Engineering and Performance}}, title = {{{Correlation between Taylor Model Prediction and Transmission Electron Microscopy-Based Microstructural Investigations of Quasi-In Situ Tensile Deformation of Additively Manufactured FeCo Alloy}}}, doi = {{10.1007/s11665-021-06065-9}}, year = {{2021}}, } @article{27509, abstract = {{ Purpose The currently existing restrictions regarding the deployment of additively manufactured components because of poor surface roughness, porosity and residual stresses as well as their influence on the low-cycle fatigue (LCF) strength are addressed in this paper. Design/methodology/approach This study aims to evaluating the effect of different pre- and post-treatments on the LCF strength of additively manufactured 316L parts. Therefore, 316L specimens manufactured by laser powder bed fusion were examined in their as-built state as well as after grinding, or coating with regard to the surface roughness, residual stresses and LCF strength. To differentiate between topographical effects and residual stress-related phenomena, stress-relieved 316L specimens served as a reference throughout the investigations. To enable an alumina coating of the 316L components, atmospheric plasma spraying was used, and the near-surface residual stresses and the surface roughness are measured and investigated. Findings The results have shown that the applied pre- and post-treatments such as stress-relief heat treatment, grinding and alumina coating have each led to an increase in LCF strength of the 316L specimens. In contrast, the non-heat-treated specimens predominantly exhibited coating delamination. Originality/value To the best of the authors’ knowledge, this is the first study of the correlation between the LCF behavior of additively manufactured uncoated 316L specimens in comparison with additively manufactured 316L specimens with an alumina coating. }}, author = {{Garthe, Kai-Uwe and Hoyer, Kay-Peter and Hagen, Leif and Tillmann, Wolfgang and Schaper, Mirko}}, issn = {{1355-2546}}, journal = {{Rapid Prototyping Journal}}, title = {{{Correlation between pre- and post-treatments of additively manufactured 316L parts and the resulting low cycle fatigue behavior}}}, doi = {{10.1108/rpj-01-2021-0017}}, year = {{2021}}, } @article{24087, abstract = {{Resorbable implants are highly beneficial to reduce patient burden since they need not be removed after a defined period. Currently, magnesium (Mg) and polymers are being applied as bioresorbable materials. However, for some applications the insufficient mechanical properties and high degradation rate of Mg cause the need for new materials. Iron (Fe)-based alloys are promising due to their biocompatibility and good mechanical properties, but their degradation rate is too low and needs to be adapted eg. via alloying with manganese (Mn). Besides, phases with high electrochemical potential lead to increased degradation of residual material with lower potential based on the galvanic coupling. Here, silver (Ag) is promising for the formation of such phases due to its high electrochemical potential (+0.8 V vs. SHE), immiscibility with Fe, biocompatibility, and anti-bacterial properties. Since remaining silver particles can lead to adverse consequences as thrombosis, these particles need to dissolve after the matrix material. Thus a silver alloy with high electrochemical potential, biocompatibility, and adjusted degradation behavior is required as an additive for iron-based bioresorbable materials. Several silver alloying systems are possible, but regarding the electrochemical potential and degradation behavior of binary alloys, calcium (Ca) and lanthanum (La) are best-suited considering their biocompatibility. Accordingly, this research addresses AgCa and AgCaLa alloys as additives for iron-based degradable materials with adapted degradation behavior.}}, author = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Filor, Viviane and Pramanik, Sudipta and Kietzmann, Manfred and Meißner, Jessica and Schaper, Mirko}}, issn = {{0925-8388}}, journal = {{Journal of Alloys and Compounds}}, title = {{{Novel AgCa and AgCaLa alloys for Fe-based bioresorbable implants with adapted degradation}}}, doi = {{10.1016/j.jallcom.2021.159544}}, year = {{2021}}, } @article{23913, abstract = {{Implementing the concept of mixed construction in modern automotive engineering requires the joining of sheet metal or extruded profiles with cast components made from different materials. As weight reduction is desired, these cast components are usually made from high-strength aluminium alloys of the Al-Si (Mn, Mg) system, which have limited weldability. The mechanical joinability of the cast components depends on their ductility, which is influenced by the microstructure. High-strength cast aluminium alloys have relatively low ductility, which leads to cracking of the joints. This limits the range of applications for cast aluminium alloys. In this study, an aluminium alloy of the Al-Si system AlSi9 is used to investigate relationships between solidification conditions during the sand casting process, microstructure, mechanical properties, and joinability. The demonstrator is a stepped plate with a minimum thickness of 2.0 mm and a maximum thickness of 4.0 mm, whereas the thickness difference between neighbour steps amounts to 0.5 mm. During casting trials, the solidification rates for different plate steps were measured. The microscopic investigations reveal a correlation between solidification rates and microstructure parameters such as secondary dendrite arm spacing. Furthermore, mechanical properties and the mechanical joinability are investigated.}}, author = {{Neuser, Moritz and Grydin, Olexandr and Andreiev, Anatolii and Schaper, Mirko}}, issn = {{2075-4701}}, journal = {{Metals}}, title = {{{Effect of Solidification Rates at Sand Casting on the Mechanical Joinability of a Cast Aluminium Alloy}}}, doi = {{10.3390/met11081304}}, year = {{2021}}, } @article{24565, abstract = {{AbstractLaser surface treatment of metals is one option to improve their properties for adhesive bonding. In this paper, a pulsed YVO4 Laser source with a wavelength of 1064 nm and a maximum power of 25 W was utilized to increase the surface area of the steel HCT490X in order to improve its bonding properties with a carbon fibre reinforced polymer (CFRP). Investigated was the influence of the scanning speed of the laser source on the bonding properties. For this purpose, the steel surfaces were ablated at a scanning speed between 1500 and 4500 mm/s. Afterwards the components were bonded with the adhesive HexBond™ 677. After lap shear tests were carried out on the specimen, the surfaces were inspected using scanning electron microscopy (SEM). The experiments revealed that the bonding quality can be improved with a high scanning speed, even when the surface is not completely ablated.}}, author = {{Voswinkel, Dietrich and Kloidt, D. and Grydin, Olexandr and Schaper, Mirko}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, number = {{2}}, pages = {{263--270}}, title = {{{Time efficient laser modification of steel surfaces for advanced bonding in hybrid materials}}}, doi = {{10.1007/s11740-020-01006-2}}, volume = {{15}}, year = {{2021}}, } @article{24566, author = {{Engelkemeier, Katja and Sun, Aijia and Voswinkel, Dietrich and Grydin, Olexandr and Schaper, Mirko and Bremser, Wolfgang}}, issn = {{2196-0216}}, journal = {{ChemElectroChem}}, pages = {{2155--2168}}, publisher = {{Wiley}}, title = {{{Zinc Anodizing: Structural Diversity of Anodic Zinc Oxide Controlled by the Type of Electrolyte}}}, doi = {{10.1002/celc.202100216}}, year = {{2021}}, } @article{23897, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Dula, Dimitri and Hengsbach, Florian and Grydin, Olexandr and Frolov, Yaroslav and Schaper, Mirko}}, issn = {{0921-5093}}, journal = {{Materials Science and Engineering: A}}, title = {{{Laser beam melting of functionally graded materials with application-adapted tailoring of magnetic and mechanical performance}}}, doi = {{10.1016/j.msea.2021.141662}}, year = {{2021}}, } @article{23911, author = {{Pramanik, Sudipta and Andreiev, Anatolii and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0142-1123}}, journal = {{International Journal of Fatigue}}, title = {{{Quasi in-situ analysis of fracture path during cyclic loading of double-edged U notched additively manufactured FeCo alloy}}}, doi = {{10.1016/j.ijfatigue.2021.106498}}, year = {{2021}}, } @article{24088, author = {{Pramanik, Sudipta and Tasche, Lennart and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{2214-8604}}, journal = {{Additive Manufacturing}}, title = {{{Investigating the microstructure of an additively manufactured FeCo alloy: an electron microscopy study}}}, doi = {{10.1016/j.addma.2021.102087}}, year = {{2021}}, } @article{23803, author = {{Reitz, Alexander and Grydin, Olexandr and Schaper, Mirko}}, journal = {{Materials Data for Smart Forming Technologies}}, location = {{Freiberg}}, title = {{{Characterization of phase transformations during graded thermo- mechanical treatment of steel 22MnB5 by means of optical methods }}}, year = {{2021}}, } @article{37239, author = {{Wallmeier, Nadine}}, journal = {{Kreis Höxter Jahrbuch}}, pages = {{202--207}}, title = {{{Plattdeutsch im Kreis Höxter. "Der Dialektatlas Mittleres Westdeutschland (DMW)" und die Frage "Wie klingt Plattdeutsch im Kreis Höxter?"}}}, year = {{2021}}, } @book{22515, author = {{Tophinke, Doris and Wallmeier, Nadine and Merten, Marie-Luis}}, publisher = {{Aschendorff Verlag}}, title = {{{Das paderbörnische Platt. Niederdeutsch im Gebiet der Kreise Paderborn und Höxter}}}, year = {{2021}}, } @inproceedings{45449, author = {{Mutschler, Tanja and Buschhüter, David and Schröder, Jan and Riese, Josef and Borowski, Andreas}}, booktitle = {{Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020}}, editor = {{Habig, Sebastian}}, pages = {{258--261}}, title = {{{Theoriekonformität von Unterrichtsplanungen im Fach Physik vor und nach dem Praxissemester}}}, volume = {{41}}, year = {{2021}}, } @inproceedings{45461, author = {{Große-Heilmann, Rike Isabel and Riese, Josef}}, booktitle = {{Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen}}, editor = {{Habig, Sebastian}}, pages = {{441--444}}, title = {{{Erwerb physikdidaktischen Wissens zum Einsatz digitaler Medien im Physikunterricht}}}, volume = {{41}}, year = {{2021}}, } @inproceedings{45460, author = {{Joswig-Käfer, Ann-Kathrin and Riese, Josef}}, booktitle = {{Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen}}, editor = {{Habig, Sebastian}}, pages = {{286--289}}, title = {{{Längsschnitt Physikdidaktischen Wissens: Ursachen für Veränderungen}}}, volume = {{41}}, year = {{2021}}, } @inproceedings{45463, author = {{Ermel, Dorothee and Riese, Josef}}, booktitle = {{Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen}}, editor = {{Habig, Sebastian}}, pages = {{585--588}}, title = {{{Praktische technische Kompetenzen im Techniklehramt}}}, volume = {{41}}, year = {{2021}}, } @inproceedings{45462, author = {{Albert, Gerrit and Riese, Josef}}, booktitle = {{Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen}}, editor = {{Habig, Sebastian}}, pages = {{581--584}}, title = {{{Digitale Kompetenzen im Techniklehramt}}}, volume = {{41}}, year = {{2021}}, } @inproceedings{45450, author = {{Schröder, Jan and Vogelsang, Christoph and Riese, Josef}}, booktitle = {{Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020}}, pages = {{266--269}}, title = {{{Entwicklung der Fähigkeit zur Unterrichtsplanung im Fach Physik}}}, volume = {{41}}, year = {{2021}}, } @article{21545, author = {{Masendorf, Lukas and Wächter, Michael and Esderts, Alfons and Otroshi, Mortaza and Meschut, Gerson}}, issn = {{8756-758X}}, journal = {{Fatigue & Fracture of Engineering Materials & Structures}}, pages = {{15}}, title = {{{Service life estimation of self‐piercing riveted joints by linear damage accumulation}}}, doi = {{10.1111/ffe.13446}}, year = {{2021}}, } @article{43493, abstract = {{We consider a measure given as the continuum limit of a one-dimensional Ising model with long-range translationally invariant interactions. Mathematically, the measure can be described by a self-interacting Poisson driven jump process. We prove a correlation inequality, estimating the magnetic susceptibility of this model, which holds for small norm of the interaction function. The bound on the magnetic susceptibility has applications in quantum field theory and can be used to prove existence of ground states for the spin boson model.}}, author = {{Hasler, David and Hinrichs, Benjamin and Siebert, Oliver}}, issn = {{0304-4149}}, journal = {{Stochastic Processes and their Applications}}, pages = {{60--79}}, publisher = {{Elsevier BV}}, title = {{{Correlation bound for a one-dimensional continuous long-range Ising model}}}, doi = {{10.1016/j.spa.2021.12.010}}, volume = {{146}}, year = {{2021}}, } @inproceedings{26406, author = {{Schubert, Philipp and Hermann, Ben and Bodden, Eric and Leer, Richard}}, booktitle = {{SCAM '21: IEEE International Working Conference on Source Code Analysis and Manipulation (Engineering Track)}}, title = {{{Into the Woods: Experiences from Building a Dataflow Analysis Framework for C/C++}}}, year = {{2021}}, } @inproceedings{26405, author = {{Schubert, Philipp and Sattler, Florian and Schiebel, Fabian and Hermann, Ben and Bodden, Eric}}, booktitle = {{2021 IEEE 21st International Working Conference on Source Code Analysis and Manipulation (SCAM)}}, title = {{{Modeling the Effects of Global Variables in Data-Flow Analysis for C/C++}}}, year = {{2021}}, } @inproceedings{29203, abstract = {{We present a monolithically integrated electronic-photonic Mach-Zehnder modulator with a linear, segmented driver on the same silicon substrate. As metric for the modulation efficiency, the external V$\pi$ is hereby reduced to only 420 mV.}}, author = {{Kress, Christian and Singh, Karanveer and Schwabe, Tobias and Preußler, Stefan and Schneider, Thomas and Scheytt, J. Christoph}}, booktitle = {{OSA Advanced Photonics Congress 2021}}, keywords = {{Analog to digital converters, Extinction ratios, Grating couplers, Modulation, Modulators, Phase shift}}, pages = {{IW1B.1}}, publisher = {{Optical Society of America}}, title = {{{High Modulation Efficiency Segmented Mach-Zehnder Modulator Monolithically Integrated with Linear Driver in 0.25 \textmum BiCMOS Technology}}}, doi = {{10.1364/IPRSN.2021.IW1B.1}}, year = {{2021}}, } @article{29204, abstract = {{An analysis of an optical Nyquist pulse synthesizer using Mach-Zehnder modulators is presented. The analysis allows to predict the upper limit of the effective number of bits of this type of photonic digital-to-analog converter. The analytical solution has been verified by means of electro-optic simulations. With this analysis the limiting factor for certain scenarios: relative intensity noise, distortions by driving the Mach-Zehnder modulator, or the signal generator phase noise can quickly be identified.}}, author = {{Kress, Christian and Bahmanian, Meysam and Schwabe, Tobias and Scheytt, J. Christoph}}, journal = {{Opt. Express}}, keywords = {{Analog to digital converters, Diode lasers, Laser sources, Phase noise, Signal processing, Wavelength division multiplexers}}, number = {{15}}, pages = {{23671–23681}}, publisher = {{OSA}}, title = {{{Analysis of the effects of jitter, relative intensity noise, and nonlinearity on a photonic digital-to-analog converter based on optical Nyquist pulse synthesis}}}, doi = {{10.1364/OE.427424}}, volume = {{29}}, year = {{2021}}, } @phdthesis{45670, author = {{ Fanasch, Patrizia}}, title = {{{Governance and Reputation in the Market for Experience Goods}}}, year = {{2021}}, } @article{34822, abstract = {{The role of domain-specific content knowledge is discussed controversially for the early childhood context. Therefore, this review aims at untangling the research on domain-specific content knowledge for early childhood educators by systematically reviewing the conceptual and operational definition of and results on early childhood educators' content knowledge in different domains. Using the scientific databases ERIC, PsycInfo and Web of Sciences, we identified 36 studies on early childhood educators' domain-specific content knowledge. By comparing these studies, we found that conceptualizations of early childhood educators' content knowledge move on a continuum between a scientific related perspective and a practice related perspective. The scientific related perspective defines content knowledge as the knowledge of key concepts, facts and rules of the domain integrating knowledge taught in primary, secondary or upper secondary school. The practice related perspective includes knowledge of key concepts, facts and rules of the domain limited to the knowledge explicitly relevant for teaching in early childhood education as well as selected domain-specific knowledge of children and teaching. Our review shows that the results and implications drawn by the study authors depend on how these authors conceptualize early childhood educators' content knowledge on this continuum. Further research, therefore, needs to consider carefully how early childhood educators' content knowledge is conceptualized. The paper further discusses gaps in this research field, such as validating methods for measuring early childhood educators' content knowledge or implementing more rigorous experimental designs to examine effects of early childhood educators' content knowledge.}}, author = {{Bruns, Julia and Gasteiger, Hedwig and Strahl, Carolin}}, issn = {{2049-6613}}, journal = {{Review of Education}}, keywords = {{content knowledge, domain-specific learning, early childhood education, teacher knowledge}}, number = {{2}}, pages = {{500--538}}, publisher = {{Wiley}}, title = {{{Conceptualising and measuring domain-specific content knowledge of early childhood educators: A systematic review}}}, doi = {{10.1002/rev3.3255}}, volume = {{9}}, year = {{2021}}, } @article{45687, author = {{Bruns, Julia and Schopferer, T.}}, journal = {{. TPS – Theorie und Praxis der Sozialpädagogik}}, pages = {{28--32}}, title = {{{Eine mustergültige Wissenschaft}}}, volume = {{11}}, year = {{2021}}, } @inproceedings{36527, author = {{Jensen, Solveig and Gasteiger, Hedwig and Bruns, Julia}}, booktitle = {{Proceedings of the 44th Conference of the International Group for the Psychology of Mathematics Education}}, editor = {{Inprasitha, Maitree and Changsri, Narumon and Boonsena, Nisakorn}}, location = {{Khon Kaen, Thailand}}, pages = {{101--109}}, title = {{{Place value and regrouping as seperate constructs of place value understanding}}}, volume = {{3}}, year = {{2021}}, } @article{34823, author = {{Bruns, Julia and Gasteiger, Hedwig and Strahl, Carolin}}, issn = {{2049-6613}}, journal = {{Review of Education}}, number = {{2}}, pages = {{539--540}}, publisher = {{Wiley}}, title = {{{Context and Implications Document for: Conceptualising and measuring domain-specific content knowledge of early childhood educators: A systematic review}}}, doi = {{10.1002/rev3.3256}}, volume = {{9}}, year = {{2021}}, }