@inproceedings{22144, author = {{Risse, L. and Woodcock, S.C. and Kullmer, G. and Schramm, B. and Richard, H.A.}}, booktitle = {{Lecture Notes in Computational Vision and Biomechanics }}, pages = {{230--238}}, title = {{{Reconstruction of a defective finger joint surface and development of an adapted external fixator}}}, year = {{2019}}, } @inproceedings{22198, abstract = {{Zuverlässige, wiederholbare Bauteileigenschaften sind unabdingbar um das Herstellungsverfahren Polymer Lasersintern im industriellen Prozess-Portfolio vieler Firmen aufnehmen zu können. Einige Unternehmen und Institute haben sich daher in jüngster Zeit mit dem Thema der reproduzierbaren Bauteileigenschaften beschäftigt. Mit der hier vorgestellten und angewandten Methodik wird nicht nur der Prozessablauf vom Bauteil bis zu Nachbearbeitung betrachtet, sondern auch die Maschinenperformance in einem Ringversuch und über einen längeren Zeitraum geprüft. Rückgrat dieser Untersuchung bildet hierbei der aus der Six Sigma Lehre stammende DMAIC (Define - Measure - Analyse - Improve - Control) Verbesserungszyklus. Hierfür wird ein Standard-Prozess definiert. Diesem folgend werden die für die Industrie oder den Anwender interessanten Messungen aufgenommen und analysiert. Anschließend wird der Prozess sowie die Messmethodik optimiert und auch Kontrollmethoden definiert. Für die Anwendung der entwickelten Methodik wird exemplarisch der Maschinentyp EOS P396 mit PA2200 untersucht. Daten für die Bestimmung der Mechanik, der Optik und der Haptik sowie für die Dimensionen und die Bauteildichte werden als Qualitätskriterium aufgenommen und über einen längeren Zeitraum analysiert. Weiteres Ziel ist es, den Messaufwand zu reduzieren und die Qualitätssicherung im Serienbtrieb zu gewährleisten.}}, author = {{Klippstein, Sven Helge and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 16th Rapid.Tech Conference}}, title = {{{Methodik zur Qualifizierung des Lasersinter Prozesses für die Serienfertigung}}}, doi = {{10.3139/9783446462441.025}}, year = {{2019}}, } @inproceedings{22442, abstract = {{Laser Beam Melting (LBM) is an Additive Manufacturing (AM) process on the threshold of serial production. Therefore, LBM has to overcome different problems such as a low productivity and minor economic efficiency. Support structures are essential for LBM; however, these structures contribute to the mentioned topics, because their removal is time consuming and cost intensive. To enable design engineers and operators to increase the efficiency of LBM, design guidelinesfor support structures suitable for post-processing are developed. For this purpose, the effect of different design parameters on various evaluation criteria is considered. Suitability for post-processing can be evaluated in terms of cost, quality and time. Therefore, test specimens are built and parameter impacts on material consumption as well as the post-processing time is examined. Furthermore, the roughness of the parts is analyzed and used as an indicator for the removability of the support structure. In addition, warpage is measured and the impact of the parameters on this criterion is examined. Based on the results, suitable design guidelines and hints for support structures are developed in order to reduce time and costs during manufacturing and post-processing. }}, author = {{Künneke, Thomas and Lieneke, Tobias and Lammers, Stefan and Zimmer, Detmar}}, booktitle = {{Proceedings of the Special Interest Group meeting on Advancing Precision in Additive Manufacturing}}, pages = {{137--140}}, title = {{{Design guidelines for post-processing of laser beam melting in context of support structures}}}, doi = {{https://www.euspen.eu/knowledge-base/AM19127.pdf}}, year = {{2019}}, } @inproceedings{22443, abstract = {{Additive Manufacturing (AM) processes generate plastic or metal parts layer-by-layer without using formative tools. The resulting advantages highlight the capability of AM to become an inherent part within the product development. However, process specific challenges such as a high surface roughness, the stair-stepping effect or geometrical deviations inhibit the industrial establishment. Thus, additively manufactured parts often need to be post-processed using established manufacturing processes. Many process parameters and geometrical factors influence the manufacturing accuracy in AM which can lead to large deviations and high scatterings. Published results concerning these deviations are also difficult to compare, because they are based on several geometries that are manufactured using different processes, materials and machine settings. It is emphasized that reliable tolerances for AM are difficult to define in standards. Within this investigation, a uniform method was developed regarding relevant test specimens to examine geometrical deviations for Laser Beam Melting (LBM), Fused Deposition Modeling (FDM) and Selective Laser Sintering (SLS) in order to derive geometrical tolerance values. The manufactured test specimens were measured using tactile and optical systems to examine the occurring geometrical deviations. The results show possible geometrical tolerance values that were classified according to the international standard DIN EN ISO 286-1.}}, author = {{Lieneke, Tobias and Künneke, Thomas and Schlenker, Fabian and Denzer, Vera and Zimmer, Detmar}}, booktitle = {{Special Interest Group Meeting: Advancing Precision in Additive Manufacturing}}, title = {{{Manufacturing Accuracy In Additive Manufacturing: A Method To Determine Geometrical Tolerances}}}, doi = {{https://www.euspen.eu/knowledge-base/AM19129.pdf}}, year = {{2019}}, } @article{22444, author = {{Künneke, Thomas and Zimmer, Detmar}}, isbn = {{0937-4167}}, journal = {{konstruktionspraxis}}, pages = {{24--26}}, publisher = {{Vogel Communications Groupe GmbH & Co. KG}}, title = {{{Schall mittels Pulver dämpfen}}}, volume = {{6}}, year = {{2019}}, } @phdthesis{22500, author = {{Kriegel, Nils-Peter}}, isbn = {{978-3-8440-7058-3}}, publisher = {{Shaker Verlag GmbH }}, title = {{{Konzeption eines energieeffizienten Betätigungs- und Haltesystems für eine Federkraftbremse}}}, year = {{2019}}, } @article{2256, abstract = {{Social psychology studies the "common enemy effect", the phenomenon that members of a group work together when they face an opponent, although they otherwise have little in common. An interesting scenario is the formation of an information network where group members individually sponsor costly links. Suppose that ceteris paribus, an outsider appears who aims to disrupt the information flow within the network by deleting some of the links. The question is how the group responds to this common enemy. We address this question for the homogeneous connections model of strategic network formation, with two-way flow of information and without information decay. For sufficiently low linkage costs, the external threat can lead to a more connected network, a positive common enemy effect. For very high but not prohibitively high linkage costs, the equilibrium network can be minimally connected and efficient in the absence of the external threat whereas it is always empty and ineffi cient in the presence of the external threat, a negative common enemy effect. For intermediate linkage costs, both connected networks and the empty network are Nash for certain cost ranges.}}, author = {{Hoyer, Britta and Haller, Hans}}, journal = {{Journal of Economic Behavior & Organization}}, pages = {{146--163}}, title = {{{The Common Enemy Effect under Strategic Network Formation and Disruption}}}, doi = {{10.1016/j.jebo.2019.03.011}}, volume = {{162}}, year = {{2019}}, } @article{22652, author = {{Hämisch, Benjamin and Büngeler, Anne and Kielar, Charlotte and Keller, Adrian and Strube, Oliver and Huber, Klaus}}, issn = {{0743-7463}}, journal = {{Langmuir}}, pages = {{12113--12122}}, title = {{{Self-Assembly of Fibrinogen in Aqueous, Thrombin-Free Solutions of Variable Ionic Strengths}}}, doi = {{10.1021/acs.langmuir.9b01515}}, volume = {{35}}, year = {{2019}}, } @article{22653, abstract = {{

Merging of bridging staples with adjacent oligonucleotide sequences leads to a moderate increase of DNA origami stability, while enzymatic ligation after assembly yields a reinforced nanostructure with superior stability at up to 37 °C and in the presence of 6 M urea.

}}, author = {{Ramakrishnan, Saminathan and Schärfen, Leonard and Hunold, Kristin and Fricke, Sebastian and Grundmeier, Guido and Schlierf, Michael and Keller, Adrian and Krainer, Georg}}, issn = {{2040-3364}}, journal = {{Nanoscale}}, pages = {{16270--16276}}, title = {{{Enhancing the stability of DNA origami nanostructures: staple strand redesign versus enzymatic ligation}}}, doi = {{10.1039/c9nr04460d}}, volume = {{11}}, year = {{2019}}, } @article{22654, abstract = {{DNA origami nanostructures are widely employed in various areas of fundamental and applied research. Due to the tremendous success of the DNA origami technique in the academic field, considerable efforts currently aim at the translation of this technology from a laboratory setting to real-world applications, such as nanoelectronics, drug delivery, and biosensing. While many of these real-world applications rely on an intact DNA origami shape, they often also subject the DNA origami nanostructures to rather harsh and potentially damaging environmental and processing conditions. Furthermore, in the context of DNA origami mass production, the long-term storage of DNA origami nanostructures or their pre-assembled components also becomes an issue of high relevance, especially regarding the possible negative effects on DNA origami structural integrity. Thus, we investigated the effect of staple age on the self-assembly and stability of DNA origami nanostructures using atomic force microscopy. Different harsh processing conditions were simulated by applying different sample preparation protocols. Our results show that staple solutions may be stored at −20 °C for several years without impeding DNA origami self-assembly. Depending on DNA origami shape and superstructure, however, staple age may have negative effects on DNA origami stability under harsh treatment conditions. Mass spectrometry analysis of the aged staple mixtures revealed no signs of staple fragmentation. We, therefore, attribute the increased DNA origami sensitivity toward environmental conditions to an accumulation of damaged nucleobases, which undergo weaker base-pairing interactions and thus lead to reduced duplex stability.}}, author = {{Kielar, Charlotte and Xin, Yang and Xu, Xiaodan and Zhu, Siqi and Gorin, Nelli and Grundmeier, Guido and Möser, Christin and Smith, David M. and Keller, Adrian}}, issn = {{1420-3049}}, journal = {{Molecules}}, pages = {{2577}}, title = {{{Effect of Staple Age on DNA Origami Nanostructure Assembly and Stability}}}, doi = {{10.3390/molecules24142577}}, volume = {{24}}, year = {{2019}}, }