@article{KunkelGebhardtMpofuetal.2018, author = {Kunkel, Maximilian Hugo and Gebhardt, Andreas and Mpofu, Khumbaulani and Kallweit, Stephan}, title = {Statistical assessment of mechanical properties of selective laser melted specimens of stainless steel}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {98}, journal = {The International Journal of Advanced Manufacturing Technology}, number = {5-8}, publisher = {Springer}, address = {London}, issn = {0268-3768}, doi = {10.1007/s00170-018-2040-8}, pages = {1409 -- 1431}, year = {2018}, abstract = {The rail business is challenged by long product life cycles and a broad spectrum of assembly groups and single parts. When spare part obsolescence occurs, quick solutions are needed. A reproduction of obsolete parts is often connected to long waiting times and minimum lot quantities that need to be purchased and stored. Spare part storage is therefore challenged by growing stocks, bound capital and issues of part ageing. A possible solution could be a virtual storage of spare parts which will be 3D printed through additive manufacturing technologies in case of sudden demand. As mechanical properties of additive manufactured parts are neither guaranteed by machine manufacturers nor by service providers, the utilization of this relatively young technology is impeded and research is required to address these issues. This paper presents an examination of mechanical properties of specimens manufactured from stainless steel through the selective laser melting (SLM) process. The specimens were produced in multiple batches. This paper interrogates the question if the test results follow a normal distribution pattern and if mechanical property predictions can be made. The results will be put opposite existing threshold values provided as the industrial standard. Furthermore, probability predictions will be made in order to examine the potential of the SLM process to maintain state-of-the-art mechanical property requirements.}, language = {en} } @article{KosterScheidweilerTieves2016, author = {Koster, Arie and Scheidweiler, Robert and Tieves, Martin}, title = {A flow based pruning scheme for enumerative equitable coloring algorithms}, series = {A flow based pruning scheme for enumerative equitable coloring algorithms}, journal = {A flow based pruning scheme for enumerative equitable coloring algorithms}, doi = {10.48550/arXiv.1607.08754}, pages = {1 -- 30}, year = {2016}, abstract = {An equitable graph coloring is a proper vertex coloring of a graph G where the sizes of the color classes differ by at most one. The equitable chromatic number is the smallest number k such that G admits such equitable k-coloring. We focus on enumerative algorithms for the computation of the equitable coloring number and propose a general scheme to derive pruning rules for them: We show how the extendability of a partial coloring into an equitable coloring can be modeled via network flows. Thus, we obtain pruning rules which can be checked via flow algorithms. Computational experiments show that the search tree of enumerative algorithms can be significantly reduced in size by these rules and, in most instances, such naive approach even yields a faster algorithm. Moreover, the stability, i.e., the number of solved instances within a given time limit, is greatly improved. Since the execution of flow algorithms at each node of a search tree is time consuming, we derive arithmetic pruning rules (generalized Hall-conditions) from the network model. Adding these rules to an enumerative algorithm yields an even larger runtime improvement.}, language = {en} } @inproceedings{KolkmannGriesSchleseretal.2005, author = {Kolkmann, Annette and Gries, Thomas and Schleser, Markus and Dilthey, Ulrich}, title = {Innovative yarn structures and coatings for textile reinforced concrete}, series = {All lectures / Techtextil Symposium : 6. - 9. 6.2005, Frankfurt am Main}, booktitle = {All lectures / Techtextil Symposium : 6. - 9. 6.2005, Frankfurt am Main}, address = {Frankfurt a.M.}, pages = {1 CD-ROM}, year = {2005}, language = {en} } @article{KnoedlerRuehlEmontsetal.2019, author = {Kn{\"o}dler, Matthias and R{\"u}hl, Clemens and Emonts, Jessica and Buyel, Johannes Felix}, title = {Seasonal weather changes affect the yield and quality of recombinant proteins produced in transgenic tobacco plants in a greenhouse setting}, series = {Frontiers in Plant Science}, journal = {Frontiers in Plant Science}, number = {10}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {1664-462X (online-ressource)}, doi = {10.3389/fpls.2019.01245}, pages = {13 Seiten}, year = {2019}, abstract = {Transgenic plants have the potential to produce recombinant proteins on an agricultural scale, with yields of several tons per year. The cost-effectiveness of transgenic plants increases if simple cultivation facilities such as greenhouses can be used for production. In such a setting, we expressed a novel affinity ligand based on the fluorescent protein DsRed, which we used as a carrier for the linear epitope ELDKWA from the HIV-neutralizing antibody 2F5. The DsRed-2F5-epitope (DFE) fusion protein was produced in 12 consecutive batches of transgenic tobacco (Nicotiana tabacum) plants over the course of 2 years and was purified using a combination of blanching and immobilized metal-ion affinity chromatography (IMAC). The average purity after IMAC was 57 ± 26\% (n = 24) in terms of total soluble protein, but the average yield of pure DFE (12 mg kg-1) showed substantial variation (± 97 mg kg-1, n = 24) which correlated with seasonal changes. Specifically, we found that temperature peaks (>28°C) and intense illuminance (>45 klx h-1) were associated with lower DFE yields after purification, reflecting the loss of the epitope-containing C-terminus in up to 90\% of the product. Whereas the weather factors were of limited use to predict product yields of individual harvests conducted for each batch (spaced by 1 week), the average batch yields were well approximated by simple linear regression models using two independent variables for prediction (illuminance and plant age). Interestingly, accumulation levels determined by fluorescence analysis were not affected by weather conditions but positively correlated with plant age, suggesting that the product was still expressed at high levels, but the extreme conditions affected its stability, albeit still preserving the fluorophore function. The efficient production of intact recombinant proteins in plants may therefore require adequate climate control and shading in greenhouses or even cultivation in fully controlled indoor farms.}, language = {en} } @article{Klocke1995, author = {Klocke, Martina}, title = {Study Units in the CIM-Oriented Study Factory}, series = {Qualification for Computer-Integrated Manufacturing. Hrsg.: Felix Rauner}, journal = {Qualification for Computer-Integrated Manufacturing. Hrsg.: Felix Rauner}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {3-540-19971-3}, pages = {38 -- 51}, year = {1995}, language = {en} } @inproceedings{KleineKallweitMichauxetal.2016, author = {Kleine, Harald and Kallweit, Stephan and Michaux, Frank and Havermann, Marc and Olivier, Herbert}, title = {PIV Measurement of Shock Wave Diffraction}, series = {18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon}, booktitle = {18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon}, pages = {1 -- 14}, year = {2016}, language = {en} } @article{KilicRaatschenKoerfgenetal.2017, author = {Kilic, S. A. and Raatschen, Hans-J{\"u}rgen and K{\"o}rfgen, B. and Apaydin, N. M. and Astaneh-Asl, A.}, title = {FE Model of the Fatih Sultan Mehmet Suspension Bridge Using Thin Shell Finite Elements}, series = {Arabian Journal for Science and Engineering}, volume = {42}, journal = {Arabian Journal for Science and Engineering}, number = {3}, publisher = {Springer Nature}, issn = {2191-4281}, doi = {10.1007/s13369-016-2316-y}, pages = {1103 -- 1116}, year = {2017}, abstract = {This paper presents the results of an eigenvalue analysis of the Fatih Sultan Mehmet Bridge. A high-resolution finite element model was created directly from the available design documents. All physical properties of the structural components were included in detail, so no calibration to the measured data was necessary. The deck and towers were modeled with shell elements. A nonlinear static analysis was performed before the eigenvalue calculation. The calculated natural frequencies and corresponding mode shapes showed good agreement with the available measured ambient vibration data. The calculation of the effective modal mass showed that nine modes had single contributions higher than 5 \% of the total mass. They were in a frequency range up to 1.2 Hz. The comparison of the results for the torsional modes especially demonstrated the advantage of using thin shell finite elements over the beam modeling approach.}, language = {en} } @inproceedings{KilicRaatschenAstanehAsletal.2015, author = {Kilic, S. A. and Raatschen, Hans-J{\"u}rgen and Astaneh-Asl, A. and Apaydin, N. M.}, title = {Finite element modeling of the Fatih Sultan Mehmet Suspension Bridge}, series = {Multi-Span Large Bridges - Proceedings of the International Conference on Multi-Span Large Bridges}, booktitle = {Multi-Span Large Bridges - Proceedings of the International Conference on Multi-Span Large Bridges}, publisher = {CRC Press}, address = {Leiden}, isbn = {9781138027572}, pages = {1169 -- 1173}, year = {2015}, language = {en} } @article{KesslerBalcGebhardtetal.2015, author = {Kessler, Julia and Balc, Nicolae and Gebhardt, Andreas and Abbas, Karim}, title = {Basic Research on Lattice Structures Focused on the Tensile Strength}, series = {Applied Mechanics and Materials}, volume = {Vol. 808}, journal = {Applied Mechanics and Materials}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, issn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.808.193}, pages = {193 -- 198}, year = {2015}, language = {en} } @inproceedings{KesslerBalcGebhardtetal.2017, author = {Kessler, Julia and Balc, Nicolae and Gebhardt, Andreas and Abbas, Karim}, title = {Basic research on lattice structures focused on the reliance of the cross sectional area and additional coatings}, series = {The 4th International Conference on Computing and Solutions in Manufacturing Engineering 2016 - CoSME'16}, booktitle = {The 4th International Conference on Computing and Solutions in Manufacturing Engineering 2016 - CoSME'16}, edition = {Vol. 94}, doi = {10.1051/matecconf/20179403008}, pages = {7 S.}, year = {2017}, language = {en} } @inproceedings{KesslerBalcGebhardt2016, author = {Kessler, Julia and Balc, Nicolae and Gebhardt, Andreas}, title = {Basic research on lattice structures focused on the strut shape and welding beads}, series = {Physics Procedia}, volume = {Vol. 83}, booktitle = {Physics Procedia}, issn = {1875-3884}, doi = {10.1016/j.phpro.2016.08.086}, pages = {833 -- 838}, year = {2016}, language = {en} } @inproceedings{KaschSchmidtEichleretal.2020, author = {Kasch, Susanne and Schmidt, Thomas and Eichler, Fabian and Thurn, Laura and Jahn, Simon and Bremen, Sebastian}, title = {Solution approaches and process concepts for powder bed-based melting of glass}, series = {Industrializing Additive Manufacturing. Proceedings of AMPA2020}, booktitle = {Industrializing Additive Manufacturing. Proceedings of AMPA2020}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-54333-4 (Print)}, doi = {10.1007/978-3-030-54334-1_7}, pages = {82 -- 95}, year = {2020}, abstract = {In the study, the process chain of additive manufacturing by means of powder bed fusion will be presented based on the material glass. In order to reliably process components additively, new concepts with different solutions were developed and investigated. Compared to established metallic materials, the properties of glass materials differ significantly. Therefore, the process control was adapted to the material glass in the investigations. With extensive parameter studies based on various glass powders such as borosilicate glass and quartz glass, scientifically proven results on powder bed fusion of glass are presented. Based on the determination of the particle properties with different methods, extensive investigations are made regarding the melting behavior of glass by means of laser beams. Furthermore, the experimental setup was steadily expanded. In addition to the integration of coaxial temperature measurement and regulation, preheating of the building platform is of major importance. This offers the possibility to perform 3D printing at the transformation temperatures of the glass materials. To improve the component's properties, the influence of a subsequent heat treatment was also investigated. The experience gained was incorporated into a new experimental system, which allows a much better exploration of the 3D printing of glass. Currently, studies are being conducted to improve surface texture, building accuracy, and geometrical capabilities using three-dimensional specimen. The contribution shows the development of research in the field of 3D printing of glass, gives an insight into the machine and process engineering as well as an outlook on the possibilities and applications.}, language = {en} } @article{KallweitWillertDuesetal.2008, author = {Kallweit, Stephan and Willert, Chris and Dues, Michael and M{\"u}ller, Ulrich}, title = {PIV for Volume Flow Metering / Kallweit, Stephan ; Willert, Chris ; Dues, Michael ; M{\"u}ller, Ulrich ; Lederer, Thomas}, pages = {6 S.}, year = {2008}, language = {en} } @article{KallweitVanlanduitVanherzeeleetal.2007, author = {Kallweit, Stephan and Vanlanduit, S. and Vanherzeele, J. and Brouns, M.}, title = {Time resolved PIV reconstruction of periodic flows / Vanlanduit, S. ; Vanherzeele, J. ; Kallweit, S. ; Brouns, M. ; Guillaume, P.}, series = {PIV'07, 7th International Symposium on Particle Image Velocimetry, Roma, IT, Sep 11-14, 2007}, journal = {PIV'07, 7th International Symposium on Particle Image Velocimetry, Roma, IT, Sep 11-14, 2007}, pages = {1 -- 14}, year = {2007}, language = {en} } @article{KallweitUchiyamaSiekmann1998, author = {Kallweit, Stephan and Uchiyama, R. and Siekmann, H.}, title = {Fault Diagnostic Method for Pump Running Conditions Based on Process Modeling and Neural Network / Uchiyama, R. ; Kallweit, S. ; Siekmann, H.}, series = {International Journal of Rotating Machinery. 4 (1998), H. 1}, journal = {International Journal of Rotating Machinery. 4 (1998), H. 1}, isbn = {1542-3034}, pages = {49 -- 59}, year = {1998}, language = {en} } @article{KallweitSchimpf2003, author = {Kallweit, Stephan and Schimpf, Axel}, title = {Photogrammetric Particle Image Velocimetry / Schimpf, Axel ; Kallweit, Stephan}, series = {Particle image velocimetry : recent improvements; proceedings of the Europiv 2 Workshop held in Zaragoza, Spain, March 31 - April 1, 2003 / edited by M. Stanislas ...}, journal = {Particle image velocimetry : recent improvements; proceedings of the Europiv 2 Workshop held in Zaragoza, Spain, March 31 - April 1, 2003 / edited by M. Stanislas ...}, publisher = {Springer}, address = {Berlin}, isbn = {3-540-21423-2}, pages = {295}, year = {2003}, language = {en} } @article{KallweitKaminskyRossietal.2008, author = {Kallweit, Stephan and Kaminsky, Radoslav and Rossi, Massimiliano and Morbiducci, Umberto}, title = {PIV Measurements of Flows in Artificial Heart Valves / Kaminsky, Radoslav ; Kallweit, Stephan ; Rossi, Massimiliano ; Morbiducci, Umberto ; Scalise, Lorenzo}, series = {Particle Image Velocimetry - New Developments and Recent Applications}, journal = {Particle Image Velocimetry - New Developments and Recent Applications}, isbn = {978-3-540-73528-1}, pages = {55 -- 72}, year = {2008}, language = {en} } @article{KallweitKaminskyRossietal.2005, author = {Kallweit, Stephan and Kaminsky, R. and Rossi, M. and Scalise, L.}, title = {PIV Measurements with high temporal Resolution behind Artificial Heart Valves / Kaminsky, R. ; Rossi, M. ; Scalise, L. ; Kallweit, S. ; Verdonck, P.}, series = {Proceedings of the 6th International Symposium on Particle Image Velocimetry}, journal = {Proceedings of the 6th International Symposium on Particle Image Velocimetry}, publisher = {Caltech}, address = {Pasadena, CA}, year = {2005}, language = {en} } @article{KallweitKaminskyRossietal.2005, author = {Kallweit, Stephan and Kaminsky, R. and Rossi, M. and Morbiducci, U.}, title = {Time resolved PIV technique for high temporal resolution measurements of prosthetic heart valves fluid dynamics / Kaminsky, R. ; Rossi, M. ; Morbiducci, U. ; Scalise, L. ; Catellini, P. ; Kallweit, S. ; Verdonck, P. ; Grigioni, M.}, series = {The International Journal of Artificial Organs. 28 (2005), H. 9}, journal = {The International Journal of Artificial Organs. 28 (2005), H. 9}, isbn = {1724-6040}, pages = {946}, year = {2005}, language = {en} } @article{KallweitKaminskyRossietal.2005, author = {Kallweit, Stephan and Kaminsky, R. and Rossi, M. and Morbiducci, U.}, title = {2D PIV Study of the flow downstream : Two prototypes of a ney monoleaflet artificial aortic heart valve prosthesis / Kaminsky, R. ; Kramm, K. ; Weber, H. J. ; Simons, A. P. ; Kallweit, S. ; Verdonck, P. R.}, series = {The International Journal of Artificial Organs. 28 (2005), H. 9}, journal = {The International Journal of Artificial Organs. 28 (2005), H. 9}, isbn = {1724-6040}, pages = {921}, year = {2005}, language = {en} }