@inproceedings{OPUS4-6272, title = {B-AMC — broadband aeronautical multi-carrier communications}, series = {Integrated Communications, Navigation and Surveillance Conference : [ICNS 2008] ; Bethesda, Md., 5 - 7 May 2008}, booktitle = {Integrated Communications, Navigation and Surveillance Conference : [ICNS 2008] ; Bethesda, Md., 5 - 7 May 2008}, organization = {Institute of Electrical and Electronics Engineers}, isbn = {978-1-4244-2303-3 ; 978-1-4244-2304-0}, pages = {1 -- 12}, year = {2008}, language = {en} } @article{AbbasBalcBremenetal.2022, author = {Abbas, Karim and Balc, Nicolae and Bremen, Sebastian and Skupin, Marco}, title = {Crystallization and aging behavior of polyetheretherketone PEEK within rapid tooling and rubber molding}, series = {Journal of Manufacturing and Materials Processing}, volume = {6}, journal = {Journal of Manufacturing and Materials Processing}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2504-4494}, doi = {10.3390/jmmp6050093}, pages = {1 -- 12}, year = {2022}, abstract = {In times of short product life cycles, additive manufacturing and rapid tooling are important methods to make tool development and manufacturing more efficient. High-performance polymers are the key to mold production for prototypes and small series. However, the high temperatures during vulcanization injection molding cause thermal aging and can impair service life. The extent to which the thermal stress over the entire process chain stresses the material and whether it leads to irreversible material aging is evaluated. To this end, a mold made of PEEK is fabricated using fused filament fabrication and examined for its potential application. The mold is heated to 200 ◦C, filled with rubber, and cured. A differential scanning calorimetry analysis of each process step illustrates the crystallization behavior and first indicates the material resistance. It shows distinct cold crystallization regions at a build chamber temperature of 90 ◦C. At an ambient temperature above Tg, crystallization of 30\% is achieved, and cold crystallization no longer occurs. Additional tensile tests show a decrease in tensile strength after ten days of thermal aging. The steady decrease in recrystallization temperature indicates degradation of the additives. However, the tensile tests reveal steady embrittlement of the material due to increasing crosslinking.}, language = {en} } @article{AbbasHedwigBalcetal.2023, author = {Abbas, Karim and Hedwig, Lukas and Balc, Nicolae and Bremen, Sebastian}, title = {Advanced FFF of PEEK: Infill strategies and material characteristics for rapid tooling}, series = {Polymers}, volume = {2023}, journal = {Polymers}, number = {15}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/polym15214293}, pages = {Artikel 4293}, year = {2023}, abstract = {Traditional vulcanization mold manufacturing is complex, costly, and under pressure due to shorter product lifecycles and diverse variations. Additive manufacturing using Fused Filament Fabrication and high-performance polymers like PEEK offer a promising future in this industry. This study assesses the compressive strength of various infill structures (honeycomb, grid, triangle, cubic, and gyroid) when considering two distinct build directions (Z, XY) to enhance PEEK's economic and resource efficiency in rapid tooling. A comparison with PETG samples shows the behavior of the infill strategies. Additionally, a proof of concept illustrates the application of a PEEK mold in vulcanization. A peak compressive strength of 135.6 MPa was attained in specimens that were 100\% solid and subjected to thermal post-treatment. This corresponds to a 20\% strength improvement in the Z direction. In terms of time and mechanical properties, the anisotropic grid and isotropic cubic infill have emerged for use in rapid tooling. Furthermore, the study highlights that reducing the layer thickness from 0.15 mm to 0.1 mm can result in a 15\% strength increase. The study unveils the successful utilization of a room-temperature FFF-printed PEEK mold in vulcanization injection molding. The parameters and infill strategies identified in this research enable the resource-efficient FFF printing of PEEK without compromising its strength properties. Using PEEK in rapid tooling allows a cost reduction of up to 70\% in tool production.}, language = {en} } @inproceedings{AbbasThurnKessleretal.2019, author = {Abbas, Karim and Thurn, Laura and Kessler, Julia and Eichler, Fabian}, title = {Basic research of the consideration of additive manufactured lattice structures under thermoand fluid dynamic loads}, series = {Modern technologies in manufacturing (MTeM 2019)}, volume = {299}, booktitle = {Modern technologies in manufacturing (MTeM 2019)}, number = {Article 01009}, doi = {10.1051/matecconf/201929901009}, pages = {8 Seiten}, year = {2019}, language = {en} } @article{AbdelLatifPeekenBenner1985, author = {Abdel-Latif, Lotfie Ahmed and Peeken, Heinz and Benner, Joachim}, title = {Thermohydrodynamic analysis of thrust-bearing with circular pads running on bubbly oil (BTHD-theory)}, series = {Journal of tribology}, volume = {107}, journal = {Journal of tribology}, number = {4}, isbn = {0742-4787}, issn = {1528-8897}, pages = {527 -- 537}, year = {1985}, language = {en} } @misc{AbdelghaniMenaaObareetal.2013, author = {Abdelghani, Adnane and Menaa, Bouzid and Obare, Sherine O. and Sch{\"o}ning, Michael Josef}, title = {Special issue on nanoscale science and technology / guest eds.: Adnane Abdelghani, Bouzid Menaa, Sherine O. Obare, Michael J. Sch{\"o}ning}, series = {International journal of nanotechnology}, volume = {Vol. 10}, journal = {International journal of nanotechnology}, number = {No. 5-7}, issn = {1741-8151 (E-Journal), 1475-7435 (Print)}, pages = {373 -- 619}, year = {2013}, language = {en} } @article{AbelKahmannMellonetal.2020, author = {Abel, Alexander and Kahmann, Stephanie Lucina and Mellon, Stephen and Staat, Manfred and Jung, Alexander}, title = {An open-source tool for the validation of finite element models using three-dimensional full-field measurements}, series = {Medical Engineering \& Physics}, volume = {77}, journal = {Medical Engineering \& Physics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1350-4533}, doi = {10.1016/j.medengphy.2019.10.015}, pages = {125 -- 129}, year = {2020}, abstract = {Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed.}, language = {en} } @inproceedings{AbelPerezVianaCiritsisetal.2017, author = {Abel, Alexander and P{\´e}rez-Viana, Daniel and Ciritsis, Bernard and Staat, Manfred}, title = {Prevention of femur neck fractures through femoroplasty}, series = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West}, booktitle = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West}, editor = {Erni, Daniel and Fischerauer, Alice and Himmel, J{\"o}rg and Seeger, Thomas and Thelen, Klaus}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-9814801-9-1}, doi = {10.17185/duepublico/43984}, pages = {114 -- 115}, year = {2017}, language = {en} } @inproceedings{AbelBoninAlbrachtetal.2010, author = {Abel, Thomas and Bonin, Dominik and Albracht, Kirsten and Zeller, Sebastian and Br{\"u}ggemann, Gert-Peter and Burkett, Brendan and Str{\"u}der, Heiko K.}, title = {Kinematic profile of the elite handcyclist}, series = {28th International Conference on Biomechanics in Sports, Marquette, Michigan, USA, July 19 - 23, 2010}, booktitle = {28th International Conference on Biomechanics in Sports, Marquette, Michigan, USA, July 19 - 23, 2010}, issn = {1999-4168}, pages = {140 -- 141}, year = {2010}, language = {en} } @article{AboulnagaZouSelmeretal.2018, author = {Aboulnaga, E. A. and Zou, H. and Selmer, Thorsten and Xian, M.}, title = {Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16}, series = {Journal of Biotechnology}, volume = {274}, journal = {Journal of Biotechnology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-1656}, doi = {10.1016/j.jbiotec.2018.03.007}, pages = {15 -- 27}, year = {2018}, abstract = {Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate.}, language = {en} }