Ingenieurwissenschaften
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- ItemNanomaterial-decorated micromotors for enhanced photoacoustic imaging(Berlin ; Heidelberg : Springer, 2023) Aziz, Azaam; Nauber, Richard; Sánchez Iglesias, Ana; Tang, Min; Ma, Libo; Liz-Marzán, Luis M.; Schmidt, Oliver G.; Medina-Sánchez, MarianaMicro-and nanorobots have the potential to perform non-invasive drug delivery, sensing, and surgery in living organisms, with the aid of diverse medical imaging techniques. To perform such actions, microrobots require high spatiotemporal resolution tracking with real-time closed-loop feedback. To that end, photoacoustic imaging has appeared as a promising technique for imaging microrobots in deep tissue with higher molecular specificity and contrast. Here, we present different strategies to track magnetically-driven micromotors with improved contrast and specificity using dedicated contrast agents (Au nanorods and nanostars). Furthermore, we discuss the possibility of improving the light absorption properties of the employed nanomaterials considering possible light scattering and coupling to the underlying metal-oxide layers on the micromotor’s surface. For that, 2D COMSOL simulation and experimental results were correlated, confirming that an increased spacing between the Au-nanostructures and the increase of thickness of the underlying oxide layer lead to enhanced light absorption and preservation of the characteristic absorption peak. These characteristics are important when visualizing the micromotors in a complex in vivo environment, to distinguish them from the light absorption properties of the surrounding natural chromophores.
- ItemProzessstabilisierung bei hohem Sekundärbrennstoffeinsatz durch Sauerstoffeindüsung bei Drehofenanlagen der Zementindustrie(Düsseldorf : VDZ gGmbH, 2015) Hoenig, Volker; Bodendiek, NilsHauptziel dieses Forschungsvorhabens war es, die Auswirkungen der Sauerstoffanreicherung von Drehofenflammen in Zementklinkerproduktionsanlagen auf das Produkt Klinker, den Ofenbetrieb und den Alternativbrennstoffeinsatz sowie auf die Abgaszusammensetzung zu evaluieren.
- ItemDimensionsanalyse für Ingenieure : Dimensionstheoretische Grundlagen und Anwendungsbeispiele(Hannover : Technische Informationsbibliothek, 2023) Kleinschmidt, WalterDer vorliegende Text stellt eine Überarbeitung und Erweiterung der Vorlesungsunterlagen dar, die der Verfasser während seiner früheren Lehrtätigkeit im Fachbereich Maschinentechnik der Universität Siegen erstellt hat. Dabei liegt der Schwerpunkt auf den für Ingenieure interessanten vielfältigen und teilweise umfänglichen Anwendungsbeispielen zur Dimensionsanalyse. Diese zweite Version v2 des Textes enthält einige Präzisierungen und weitere Anwendungsbeispiele.
- ItemA transportable Paul-trap for levitation and accurate positioning of micron-scale particles in vacuum for laser-plasma experiments(Melville, NY : American Institute of Physics, 2018) Ostermayr, T.M.; Gebhard, J.; Haffa, D.; Kiefer, D.; Kreuzer, C.; Allinger, K.; Bömer, C.; Braenzel, J.; Schnürer, M.; Cermak, I.; Schreiber, J.; Hilz, P.We report on a Paul-trap system with large access angles that allows positioning of fully isolated micrometer-scale particles with micrometer precision as targets in high-intensity laser-plasma interactions. This paper summarizes theoretical and experimental concepts of the apparatus as well as supporting measurements that were performed for the trapping process of single particles.
- ItemGenerating circularly polarized radiation in the extreme ultraviolet spectral range at the free-electron laser FLASH(Melville, NY : American Institute of Physics, 2017) von Korff Schmising, Clemens; Weder, David; Noll, Tino; Pfau, Bastian; Hennecke, Martin; Strüber, Christian; Radu, Ilie; Schneider, Michael; Staeck, Steffen; Günther, Christian M.; Lüning, Jan; Merhe, Alaa el dine; Buck, Jens; Hartmann, Gregor; Viefhaus, Jens; Treusch, Rolf; Eisebitt, StefanA new device for polarization control at the free electron laser facility FLASH1 at DESY has been commissioned for user operation. The polarizer is based on phase retardation upon reflection off metallic mirrors. Its performance is characterized in three independent measurements and confirms the theoretical predictions of efficient and broadband generation of circularly polarized radiation in the extreme ultraviolet spectral range from 35 eV to 90 eV. The degree of circular polarization reaches up to 90% while maintaining high total transmission values exceeding 30%. The simple design of the device allows straightforward alignment for user operation and rapid switching between left and right circularly polarized radiation.