@inproceedings{AyedStrieganKustereretal.2017, author = {Ayed, Anis Haj and Striegan, Constantin J. D. and Kusterer, Karsten and Funke, Harald and Kazari, M. and Horikawa, Atsushi and Okada, Kunio}, title = {Automated design space exploration of the hydrogen fueled "Micromix" combustor technology}, pages = {1 -- 8}, year = {2017}, abstract = {Combined with the use of renewable energy sources for its production, Hydrogen represents a possible alternative gas turbine fuel for future low emission power generation. Due to its different physical properties compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for Dry Low NOx (DLN) Hydrogen combustion. This makes the development of new combustion technologies an essential and challenging task for the future of hydrogen fueled gas turbines. The newly developed and successfully tested "DLN Micromix" combustion technology offers a great potential to burn hydrogen in gas turbines at very low NOx emissions. Aiming to further develop an existing burner design in terms of increased energy density, a redesign is required in order to stabilise the flames at higher mass flows and to maintain low emission levels. For this purpose, a systematic design exploration has been carried out with the support of CFD and optimisation tools to identify the interactions of geometrical and design parameters on the combustor performance. Aerodynamic effects as well as flame and emission formation are observed and understood time- and cost-efficiently. Correlations between single geometric values, the pressure drop of the burner and NOx production have been identified as a result. This numeric methodology helps to reduce the effort of manufacturing and testing to few designs for single validation campaigns, in order to confirm the flame stability and NOx emissions in a wider operating condition field.}, language = {en} } @article{AyedKustererFunkeetal.2017, author = {Ayed, Anis Haj and Kusterer, Karsten and Funke, Harald and Keinz, Jan and Bohn, D.}, title = {CFD based exploration of the dry-low-NOx hydrogen micromix combustion technology at increased energy densities}, series = {Propulsion and Power Research}, volume = {6}, journal = {Propulsion and Power Research}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {2212-540X}, doi = {10.1016/j.jppr.2017.01.005}, pages = {15 -- 24}, year = {2017}, language = {en} } @article{AyedKustererFunkeetal.2016, author = {Ayed, Anis Haj and Kusterer, Karsten and Funke, Harald and Keinz, Jan}, title = {CFD Based Improvement of the DLN Hydrogen Micromix Combustion Technology at Increased Energy Densities}, series = {American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS)}, volume = {26}, journal = {American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS)}, number = {3}, publisher = {GSSRR}, issn = {2313-4402}, pages = {290 -- 303}, year = {2016}, abstract = {Combined with the use of renewable energy sources for its production, Hydrogen represents a possible alternative gas turbine fuel within future low emission power generation. Due to the large difference in the physical properties of Hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for Dry Low NOx (DLN) Hydrogen combustion. Thus, the development of DLN combustion technologies is an essential and challenging task for the future of Hydrogen fuelled gas turbines. The DLN Micromix combustion principle for hydrogen fuel has been developed to significantly reduce NOx-emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized diffusion-type flames. The major advantages of this combustion principle are the inherent safety against flash-back and the low NOx-emissions due to a very short residence time of reactants in the flame region of the micro-flames. The Micromix Combustion technology has been already proven experimentally and numerically for pure Hydrogen fuel operation at different energy density levels. The aim of the present study is to analyze the influence of different geometry parameter variations on the flame structure and the NOx emission and to identify the most relevant design parameters, aiming to provide a physical understanding of the Micromix flame sensitivity to the burner design and identify further optimization potential of this innovative combustion technology while increasing its energy density and making it mature enough for real gas turbine application. The study reveals great optimization potential of the Micromix Combustion technology with respect to the DLN characteristics and gives insight into the impact of geometry modifications on flame structure and NOx emission. This allows to further increase the energy density of the Micromix burners and to integrate this technology in industrial gas turbines.}, language = {en} } @article{AyalaHarrisKleefeldetal.2023, author = {Ayala, Rafael Ceja and Harris, Isaac and Kleefeld, Andreas and Pallikarakis, Nikolaos}, title = {Analysis of the transmission eigenvalue problem with two conductivity parameters}, series = {Applicable Analysis}, journal = {Applicable Analysis}, publisher = {Taylor \& Francis}, issn = {0003-6811}, doi = {10.1080/00036811.2023.2181167}, pages = {37 Seiten}, year = {2023}, abstract = {In this paper, we provide an analytical study of the transmission eigenvalue problem with two conductivity parameters. We will assume that the underlying physical model is given by the scattering of a plane wave for an isotropic scatterer. In previous studies, this eigenvalue problem was analyzed with one conductive boundary parameter whereas we will consider the case of two parameters. We prove the existence and discreteness of the transmission eigenvalues as well as study the dependence on the physical parameters. We are able to prove monotonicity of the first transmission eigenvalue with respect to the parameters and consider the limiting procedure as the second boundary parameter vanishes. Lastly, we provide extensive numerical experiments to validate the theoretical work.}, language = {en} } @article{AyalaHarrisKleefeld2024, author = {Ayala, Rafael Ceja and Harris, Isaac and Kleefeld, Andreas}, title = {Direct sampling method via Landweber iteration for an absorbing scatterer with a conductive boundary}, series = {Inverse Problems and Imaging}, volume = {18}, journal = {Inverse Problems and Imaging}, number = {3}, publisher = {AIMS}, address = {Springfield}, issn = {1930-8337}, doi = {10.3934/ipi.2023051}, pages = {708 -- 729}, year = {2024}, abstract = {In this paper, we consider the inverse shape problem of recovering isotropic scatterers with a conductive boundary condition. Here, we assume that the measured far-field data is known at a fixed wave number. Motivated by recent work, we study a new direct sampling indicator based on the Landweber iteration and the factorization method. Therefore, we prove the connection between these reconstruction methods. The method studied here falls under the category of qualitative reconstruction methods where an imaging function is used to recover the absorbing scatterer. We prove stability of our new imaging function as well as derive a discrepancy principle for recovering the regularization parameter. The theoretical results are verified with numerical examples to show how the reconstruction performs by the new Landweber direct sampling method.}, language = {en} } @inproceedings{AuthCzarneckiBensberg2019, author = {Auth, Gunnar and Czarnecki, Christian and Bensberg, Frank}, title = {Impact of robotic process automation on enterprise architectures}, series = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, booktitle = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, editor = {Draude, Claude and Lange, Martin and Sick, Bernhard and Gesellschaft f{\"u}r Informatik e.V. (GI),}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885796893}, issn = {1617-5468}, doi = {10.18420/inf2019_ws05}, pages = {59 -- 65}, year = {2019}, abstract = {The initial idea of Robotic Process Automation (RPA) is the automation of business processes through the presentation layer of existing application systems. For this simple emulation of user input and output by software robots, no changes of the systems and architecture is required. However, considering strategic aspects of aligning business and technology on an enterprise level as well as the growing capabilities of RPA driven by artificial intelligence, interrelations between RPA and Enterprise Architecture (EA) become visible and pose new questions. In this paper we discuss the relationship between RPA and EA in terms of perspectives and implications. As workin- progress we focus on identifying new questions and research opportunities related to RPA and EA.}, language = {en} } @inproceedings{AugensteinKuperjansLucas2002, author = {Augenstein, Eckardt and Kuperjans, Isabel and Lucas, K.}, title = {EUSEBIA - Decision-Support-System for Technical, Economical and Ecological Design and Evaluation of Industrial Energy Systems}, series = {ECOS 2002 : proceedings of the 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, Berlin, Germany July 3 - 5, 2002. - Vol. 1}, booktitle = {ECOS 2002 : proceedings of the 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, Berlin, Germany July 3 - 5, 2002. - Vol. 1}, editor = {Tsatsaronis,, Georgios}, publisher = {Techn. Univ., Inst. for Energy Engineering}, address = {Berlin}, isbn = {3-00-009533-0}, pages = {446 -- 453}, year = {2002}, language = {en} } @inproceedings{AugensteinHerbergsKuperjansetal.2005, author = {Augenstein, Eckardt and Herbergs, S. and Kuperjans, Isabel and Lucas, K.}, title = {Simulation of industrial energy supply systems with integrated cost optimization}, series = {Proceedings of ECOS 2005, the 18th International Conference on Efficiency, Cost, Optimization, Simulation, and Environmental Impact of Energy Systems : Trondheim, Norway, June 20 - 22, 2005. - Vol. 2}, booktitle = {Proceedings of ECOS 2005, the 18th International Conference on Efficiency, Cost, Optimization, Simulation, and Environmental Impact of Energy Systems : Trondheim, Norway, June 20 - 22, 2005. - Vol. 2}, editor = {Kjelstrup, Signe}, publisher = {Tapir Academic Press}, address = {Trondheim}, isbn = {82-519-2041-8}, pages = {627 -- 634}, year = {2005}, language = {en} } @article{AuffrayBruyndonckxDevroedeetal.2004, author = {Auffray, E. and Bruyndonckx, P. and Devroede, O. and Fedorov, A. and Ziemons, Karl}, title = {The ClearPET project}, series = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {527}, journal = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, number = {1-2}, isbn = {0168-9002}, pages = {171 -- 174}, year = {2004}, abstract = {The Crystal Clear Collaboration has designed and is building a high-resolution small animal PET scanner. The design is based on the use of the Hamamatsu R7600-M64 multi-anode photomultiplier tube and a LSO/LuYAP phoswich matrix with one to one coupling between the crystals and the photo-detector. The complete system will have 80 PM tubes in four rings with an inner diameter of 137 mm and an axial field of view of 110 mm. The PM pulses are digitized by free-running ADCs and digital data processing determines the gamma energy, the phoswich layer and even the pulse arrival time. Single gamma interactions are recorded and coincidences are found by software. The gantry allows rotation of the detector modules around the field of view. Simulations, and measurements a 2×4 module test set-up predict a spatial resolution of 1.5 mm in the centre of the field of view and a sensitivity of 5.9\% for a point source in the centre of the field of view.}, language = {en} } @article{AttarMerkKotliaretal.2019, author = {Attar, Mandana Hossein Zadeh and Merk, Hans F. and Kotliar, Konstantin and Wurpts, Gerda and R{\"o}seler, Stefani and Moll-Slodowy, Silke and Plange, Johann and Baron, Jens Malte and Balakirski, Galina}, title = {The CD63 basophil activation test as a diagnostic tool for assessing autoimmunity in patients with chronic spontaneous urticaria}, series = {European Journal of Dermatology}, volume = {29}, journal = {European Journal of Dermatology}, number = {6}, doi = {10.1684/ejd.2019.3680}, pages = {614 -- 618}, year = {2019}, language = {en} } @article{AtlasBrealeyDharetal.2012, author = {Atlas, Glen and Brealey, David and Dhar, Sunil and Dikta, Gerhard and Singer, Meryvn}, title = {Additional hemodynamic measurements with an esophageal Doppler monitor: a preliminary report of compliance, force, kinetic energy, and afterload in the clinical setting}, series = {Journal of clinical monitoring and computing}, journal = {Journal of clinical monitoring and computing}, number = {26}, publisher = {Springer Nature}, address = {London}, isbn = {1573-2614}, doi = {10.1007/s10877-012-9386-5}, pages = {473 -- 482}, year = {2012}, abstract = {The esophageal Doppler monitor (EDM) is a minimally-invasive hemodynamic device which evaluates both cardiac output (CO), and fluid status, by estimating stroke volume (SV) and calculating heart rate (HR). The measurement of these parameters is based upon a continuous and accurate approximation of distal thoracic aortic blood flow. Furthermore, the peak velocity (PV) and mean acceleration (MA), of aortic blood flow at this anatomic location, are also determined by the EDM. The purpose of this preliminary report is to examine additional clinical hemodynamic calculations of: compliance (C), kinetic energy (KE), force (F), and afterload (TSVRi). These data were derived using both velocity-based measurements, provided by the EDM, as well as other contemporaneous physiologic parameters. Data were obtained from anesthetized patients undergoing surgery or who were in a critical care unit. A graphical inspection of these measurements is presented and discussed with respect to each patient's clinical situation. When normalized to each of their initial values, F and KE both consistently demonstrated more discriminative power than either PV or MA. The EDM offers additional applications for hemodynamic monitoring. Further research regarding the accuracy, utility, and limitations of these parameters is therefore indicated.}, language = {en} } @article{AsanteAsamaniKleefeldWade2020, author = {Asante-Asamani, E.O. and Kleefeld, Andreas and Wade, B.A.}, title = {A second-order exponential time differencing scheme for non-linear reaction-diffusion systems with dimensional splitting}, series = {Journal of Computational Physics}, volume = {415}, journal = {Journal of Computational Physics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9991}, doi = {10.1016/j.jcp.2020.109490}, year = {2020}, abstract = {A second-order L-stable exponential time-differencing (ETD) method is developed by combining an ETD scheme with approximating the matrix exponentials by rational functions having real distinct poles (RDP), together with a dimensional splitting integrating factor technique. A variety of non-linear reaction-diffusion equations in two and three dimensions with either Dirichlet, Neumann, or periodic boundary conditions are solved with this scheme and shown to outperform a variety of other second-order implicit-explicit schemes. An additional performance boost is gained through further use of basic parallelization techniques.}, language = {en} } @article{ArtmannZhouStacheBuettneretal.2002, author = {Artmann, Gerhard and Zhou-Stache, J. and Buettner, R. and Mittermayer, C. [u.a.]}, title = {Inhibition of TNF-alpha induced cell death in HUVEC and Jurkat cells by protocatechuic acid. Zhou-Stache, J.; Buettner, R.; Artmann, Gerhard Michael; Mittermayer, C.; Bosserhoff, A. K.}, series = {Medical and Biological Engineering and Computing. 40 (2002), H. 6}, journal = {Medical and Biological Engineering and Computing. 40 (2002), H. 6}, isbn = {0140-0118}, pages = {698 -- 703}, year = {2002}, language = {en} } @article{ArtmannZerlinDigeletal.2007, author = {Artmann, Gerhard and Zerlin, Kay and Digel, Ilya and Stadler, Andreas M.}, title = {Physical discontinuities at body temperature in human red blood cells / Artmann, GM ; Zerlin, K ; Digel, I ; Stadler, A ; Zaccai, G ; Temiz, AA}, series = {Tissue Engineering. 13 (2007), H. 7}, journal = {Tissue Engineering. 13 (2007), H. 7}, isbn = {1076-3279}, pages = {1778 -- 1778}, year = {2007}, language = {en} } @article{ArtmannZerlinDigel2008, author = {Artmann, Gerhard and Zerlin, Kay and Digel, Ilya}, title = {Hemoglobin Senses Body Temperature}, series = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, journal = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-75408-4}, pages = {415 -- 447}, year = {2008}, language = {en} } @article{ArtmannZang1990, author = {Artmann, Gerhard and Zang, Werner}, title = {Fully automatic measurement of rheologic parameters of red blood cells = Laborautomat zur Messung mechanischer Eigenschaften roter Blutzellen}, series = {Biomedizinische Technik = Biomedical engineering. 35 (1990), H. Suppl. 3}, journal = {Biomedizinische Technik = Biomedical engineering. 35 (1990), H. Suppl. 3}, isbn = {0013-5585}, pages = {94 -- 96}, year = {1990}, language = {en} } @article{ArtmannTrzewikMallipattuetal.2001, author = {Artmann, Gerhard and Trzewik, J{\"u}rgen and Mallipattu, S. K. and Delano, F. A. [u.a.]}, title = {Evidence for a second valve system in Lymphatics: Endothelial Microvalves. Trzewik, J{\"u}rgen; Mallipattu, S. K.; Artmann, Gerhard Michael; Delano, F. A.; Schmid-Schonbein, G. W}, series = {The FASEB Journal. 15 (2001)}, journal = {The FASEB Journal. 15 (2001)}, isbn = {1530-6860}, pages = {1711 -- 1717}, year = {2001}, language = {en} } @article{ArtmannTrzewikAtes2002, author = {Artmann, Gerhard and Trzewik, J{\"u}rgen and Ates, M.}, title = {A novel method to quantify mechanical tension in cell monolayers. Trzewik, J{\"u}rgen; Ates, M., Artmann, Gerhard Michael}, series = {Biomedizinische Technik. 47 (2002), H. Suppl. 1. Pt. 1}, journal = {Biomedizinische Technik. 47 (2002), H. Suppl. 1. Pt. 1}, isbn = {0013-5585}, pages = {379 -- 381}, year = {2002}, language = {en} } @article{ArtmannTrzewikSchmidSchoenbein2000, author = {Artmann, Gerhard and Trzewik, J. and Schmid-Sch{\"o}nbein, G. W.}, title = {Investigation on lymphatic endothelial microvalves / Trzewik, J. ; Artmann, G. M. ; Schmid-Sch{\"o}nbein, G. W.}, series = {Biomedizinische Technik = Biomedical Engineering. 45 (2000), H. s1}, journal = {Biomedizinische Technik = Biomedical Engineering. 45 (2000), H. s1}, isbn = {1862-278X}, pages = {521 -- 522}, year = {2000}, language = {en} } @book{ArtmannTemizArtmannZhubanovaetal.2018, author = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya}, title = {Biological, physical and technical basics of cell engineering}, editor = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-10-7903-0}, pages = {xxiv, 481 Seiten ; Illustrationen, Diagramme}, year = {2018}, language = {en} }