TY - GEN A1 - Şen, Gökçen Devlet A1 - Machado, Juan E. A1 - Schiffer, Johannes T1 - A cost-optimal predictive operation scheme for sector-coupled energy plants with start-up delays and start-up costs T2 - IFAC-PapersOnLine N2 - In this work we present a cost-optimal energy management scheme for sector-coupled energy plants, focusing on systems that enable gas-to-electricity, gas-to-heat, and power-to-heat conversions. To capture realistic operational challenges, the considered system model incorporates dynamic constraints, including start-up delays and off-time-dependent start-up costs. By accounting for the impact of these factors, we demonstrate on a case study that they can significantly reduce overall operational costs. The energy management problem is cast as a mixed-integer nonlinear programming (MINLP) problem, which is then solved within a model predictive control (MPC) framework. The proposed approach provides a structured methodology for real-time energy management, enhancing energy efficiency while minimizing costs. KW - Sector-coupling KW - Energy management KW - Mixed integer nonlinear programming KW - Model predictive control Y1 - 2025 U6 - https://doi.org/10.1016/j.ifacol.2025.08.143 SN - 2405-8963 VL - 59 IS - 9 SP - 241 EP - 246 PB - Elsevier BV CY - Amsterdam ER - TY - CHAP A1 - Łobaza, Justyna A1 - Kot, Małgorzata A1 - Schmeißer, Dieter T1 - Analysis of surface oxidation of TiON ALD films T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - Titanium oxynitride (TiON) films are interesting due to their remarkable optical and electronic properties which strongly depend on the O/N ratio. However, it is known that films containing Ti are prone to oxidation in contact with the air [1]. In this work, we study the thickness of a surface oxidation layer which is inherently formed on the atomic layer deposition (ALD) grown TiON/TiN films on Si substrate. We use an Ar+ ion bombardment source and X-ray photoelectron spectroscopy (XPS) for this analysis. We calibrate the sputter rate by using substrate signal intensity decay (here Si 2p) in the XPS spectra of the 5 nm thick TiON sample accordingly. This rate is assumed to be constant when films with a larger thickness are analyzed. We find that the surface oxidation layer is about 1 nm thick, independent on the detailed ALD parameters of the films. The TiN films found underneath are close to the stoichiometric values and have a residual O content below 5%. Finally, we compare these data to our previous results collected with synchrotron-based radiation source [2,3]. References: [1] Sowinska et al., Applied Physics Letters 100, 233509 (2012). [2] M. Sowinska et al., Applied Surface Science 381, 42-47 (2016). [3] M. Sowińska et al., Journal of Vacuum Science and Tech- nology A, 01A12734 (2016). KW - titanium oxynitride KW - X-Rax photoelectron spectroscopy KW - depth profiling KW - sputtering Y1 - 2017 UR - http://www.dpg-verhandlungen.de/year/2017/conference/dresden/part/ds/session/21/contribution/7 SN - 0420-0195 SP - S. 202 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - GEN A1 - Ünsal, Ismail A1 - Hirtler, Markus A1 - Sviridov, Alexander A1 - Bambach, Markus A1 - Hama-Saleh, Rebar A1 - Weisheit, Andreas A1 - Schleifenbaum, Johannes Henrich A1 - Kamaliev, Mike A1 - Tekkaya, A. Erman T1 - Investigation of martensite-transformation and forming properties of additively reinforced 22MnB5 sheet metals T2 - AIP Conference Proceedings Y1 - 2019 SN - 978-0-7354-1847-9 U6 - https://doi.org/10.1063/1.5112735 VL - 2113 IS - 1 ER - TY - GEN A1 - Ünsal, Ismail A1 - Hirtler, Markus A1 - Sviridov, Alexander A1 - Bambach, Markus ED - Bambach, Markus T1 - Material Properties of Features Produced from EN AW 6016 by Wire-Arc Additive Manufacturing T2 - Procedia Manufacturing; Part of Special issue: 23rd International Conference on Material Forming Y1 - 2020 U6 - https://doi.org/10.1016/j.promfg.2020.04.131 SN - 2351-9789 VL - 47 SP - 1129 EP - 1133 ER - TY - GEN A1 - Ünsal, Ismail A1 - Hama-Saleh, Rebar A1 - Sviridov, Alexander A1 - Bambach, Markus A1 - Weisheit, Andreas A1 - Schleifenbaum, Johannes Henrich T1 - Mechanical properties of sheet metal components with local reinforcement produced by additive manufacturing T2 - Proceedings of the 21st International ESAFORM Conference on Material Forming, ESAFORM 2018, Palermo, Italy, 23-25 April 2018 Y1 - 2018 SN - 978-0-7354-1663-5 U6 - https://doi.org/10.1063/1.5035054 PB - AIP Publishing CY - Melville, New York ER - TY - THES A1 - Öztürk, Arzu T1 - Architektur der scaenae frons des Theaters von Perge KW - scaenae frons KW - Theater KW - Perge KW - Römische Architektur Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-000000726 ER - TY - GEN A1 - Öztürk, Alisan A1 - Bonfert-Taylor, Petra A1 - Fügenschuh, Armin ED - Krömker, Detlef ED - Schroeder, Ulrik T1 - Using Data to Improve Programming Instruction T2 - DeLFI 2018 : die 16. E-Learning Fachtagung Informatik der Gesellschaft für Informatik e. V. : 10.-12. September 2018 Frankfurt am Main, Deutschland Y1 - 2018 UR - https://dl.gi.de/handle/20.500.12116/21049 SN - 978-3-88579-678-7 SP - 23 EP - 32 PB - Gesellschaft für Informatik e.V. CY - Bonn ER - TY - GEN A1 - Özgünoğlu, Mehmet A1 - Mouokue, Gerard A1 - Oevermann, Michael A1 - Bensow, Rickard E. T1 - Numerical investigation of cavitation erosion in high-pressure fuel injector in the presence of surface deviations T2 - Fuel N2 - This study investigates cavitation-induced erosion in high-pressure fuel injectors using numerical simulations, focusing on the effects of surface deviations, turbulence modeling, and a refined approach for the erosion assessment. The proposed erosion model combines advanced erosion indicators to enhance predictive accuracy while addressing limitations in existing methodologies. Cavitation dynamics are simulated with the modified Zwart–Gerber–Belamri model, employing Reynolds-averaged Navier–Stokes (RANS) and Large Eddy Simulation (LES) approaches. Numerical results for a high-lift needle position are validated against experimental data, providing insights into erosion behavior in industrial heavy-duty injectors. Both Computer-Aided Design (CAD) and Tomography Scan (TS) models are used to evaluate the impact of surface deviations on erosion patterns. Results reveal that incorporating surface deviations reduces the vapor volume and alters the erosion patterns. LES simulations exhibit enhanced sensitivity to the surface deviations, capturing finer turbulence structures and local pressure fluctuations, whereas RANS provides reasonable accuracy with lower computational cost. KW - Fuel injector KW - CFD KW - Cavitation erosion KW - Surface deviations Y1 - 2025 U6 - https://doi.org/10.1016/j.fuel.2024.134174 SN - 0016-2361 VL - 386 SP - 1 EP - 21 PB - Elsevier BV ER - TY - GEN A1 - Özgen-Xian, Ilhan A1 - Molins, Sergi A1 - Kesserwani, Georges A1 - Caviedes-Voullieme, Daniel A1 - Steefel, Carl I. T1 - Meshing workflows for multiscale hydrological simulations: Wavelet-based approach improves model accuracy. T2 - AGU 100 : Fall Meeting 2019, San Francisco, CA, 9-13 December2019 N2 - The high computational cost of large-scale, process-based hydrological simulations can be approached using variable resolution meshes, where only the region around significant topographic features is refined. However, generating quality variable resolution meshes from digital elevation data is non-trivial. In literature, usually a slope or curvature-based criterion is defined to detect regions of refinement. These techniques often involve a number of free parameters that control the finest and coarsest resolutions, and the transition between fine resolution to coarse resolution. The influence of these parameters on the resulting mesh is usually not well-understood. In order to overcome the large number of free parameters involved, we propose to carry out the Mallat decomposition of the digital elevation data using the Haar wavelet. This gives a nested multilevel representation of the elevation data, split into average coefficients and detail coefficients. Applying hard-thresholding to these detail coefficients assigns a required level of refinement to each data point. This reduces the number of free parameters to exactly one: the acceptable error threshold. In this presentation, we focus on identifying which geomorphometric parameter(s) should be used to steer mesh refinement. We compare zero-inertia model simulation runs on meshes generated by decomposing elevation and slope. We hypothesize that because of the form of the Haar wavelet, the first mesh refinement essentially is using the gradient information, while the latter is using the curvature as refinement criterion. Our results suggest that in high-elevation catchments the curvature of the topography is a far better indicator for refinement than the slope. Using the Mallat decomposition on the tensor of the first derivative of the bed elevation (i.e., bed slope) for mesh refinement yields better agreement in the hydrograph compared to the decomposition of the bed elevation. We present surface runoff results for the Lower Triangle catchment, CO, USA, to illustrate the performance of the wavelet-based local mesh refinement. Y1 - 2019 UR - https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/503978 CY - San Francisco, California ER - TY - GEN A1 - Özgen-Xian, Ilhan A1 - Kesserwani, Georges A1 - Caviedes-Voullième, Daniel A1 - Molins, Sergi A1 - Xu, Zexuan A1 - Dwivedi, Dipankar A1 - Moulton, J. David A1 - Steefel, Carl I. T1 - Wavelet-based local mesh refinement for rainfall–runoff simulations T2 - Journal of Hydroinformatics N2 - A wavelet-based local mesh refinement (wLMR) strategy is designed to generate multiresolution and unstructured triangular meshes from real digital elevation model (DEM) data for efficient hydrological simulations at the catchment scale. The wLMR strategy is studied considering slope- and curvature-based refinement criteria to analyze DEM inputs: the slope-based criterion uses bed elevation data as input to the wLMR strategy, whereas the curvature-based criterion feeds the bed slope data into it. The performance of the wLMR meshes generated by these two criteria is compared for hydrological simulations; first, using three analytical tests with the systematic variation in topography types and then by reproducing laboratory- and real-scale case studies. The bed elevation on the wLMR meshes and their simulation results are compared relative to those achieved on the finest uniform mesh. Analytical tests show that the slope- and curvature-based criteria are equally effective with the wLMR strategy, and that it is easier to decide which criterion to take in relation to the (regular) shape of the topography. For the realistic case studies: (i) slope analysis provides a better metric to assess the correlation of a wLMR mesh to the fine uniform mesh and (ii) both criteria predict outlet hydrographs with a close predictive accuracy to that on the uniform mesh, but the curvature-based criterion is found to slightly better capture the channeling patterns of real DEM data. KW - diffusion-wave hydrological modeling KW - multiresolution triangular mesh generation KW - overland flow at catchment scale KW - slope- vs. curvature-based topographic inputs KW - wavelet-based local mesh refinement Y1 - 2020 U6 - https://doi.org/10.2166/hydro.2020.198 SN - 1464-7141 SN - 1465-1734 VL - 22 IS - 5 SP - 1059 EP - 1077 ER - TY - CHAP A1 - Ötsch, Walter A1 - Priddat, Birger A1 - Groß, Steffen ED - Ötsch, Walter ED - Priddat, Birger ED - Groß, Steffen T1 - Imaginaton und Ökonomie: zum Vorwort T2 - Das Imaginative der Politischen Ökonomie Y1 - 2024 SN - 978-3-7316-1536-1 SP - 7 EP - 28 PB - Metropolis CY - Marburg ET - 1. Auflage ER - TY - CHAP A1 - Öngüner, Emir A1 - Zanoun, El-Sayed A1 - König, Franziska A1 - Egbers, Christoph T1 - Structure Investigation in Pipe Flow at High Reynolds Numbers Y1 - 2016 SN - 978-3-319-29130-7 SP - 217 EP - 220 PB - Springer CY - Berlin ER - TY - CHAP A1 - Öngüner, Emir A1 - Zanoun, El-Sayed A1 - Fiorini, Tommaso A1 - Bellani, Gabriele A1 - Shahirpour, Amir A1 - Egbers, Christoph A1 - Talamelli, Alessandro ED - Örlü, Ramis ED - Talamelli, Alessandro ED - Peinke, Joachim ED - Oberlack, Martin T1 - Wavenumber Dependence of Very Large-Scale Motions in CICLoPE at 4800 ≤ Reτ ≤ 37.000 T2 - Progress in Turbulence VII, Proceedings of the iTi Conference in Turbulence 2016 Y1 - 2017 UR - https://link.springer.com/chapter/10.1007/978-3-319-57934-4_15 SN - 978-3-319-57933-7 SP - 101 EP - 106 PB - Springer CY - Cham ER - TY - CHAP A1 - Öngüner, Emir A1 - Zanoun, El-Sayed A1 - Egbers, Christoph T1 - Turbulent Pipe Flow Structure Analysis in CoLa-Pipe T2 - Book of abstracts, 85th Annual Meeting of the International Association of Applied Mathematics and Mechanics, March 10 - 14, 2014, Erlangen Y1 - 2014 SP - S. 493 PB - Gesellschaft für Angewandte Mathematik und Mechanik ER - TY - CHAP A1 - Öngüner, Emir A1 - Zanoun, El-Sayed A1 - Egbers, Christoph ED - Örlü, Ramis ED - Talamelli, Alessandro ED - Peinke, Joachim ED - Oberlack, Martin T1 - Streamwise Auto-Correlation Analysis in Turbulent Pipe Flow Using Particle Image Velocimetry at High Reynolds Numbers T2 - Progress in Turbulence VII, Proceedings of the iTi Conference in Turbulence 2016 Y1 - 2017 UR - https://link.springer.com/chapter/10.1007/978-3-319-57934-4_16 SN - 978-3-319-57933-7 SP - 107 EP - 112 PB - Springer CY - Cham ER - TY - CHAP A1 - Öngüner, Emir A1 - König, Franziska A1 - Zanoun, El-Sayed A1 - Egbers, Christoph T1 - Experimentelle Untersuchung der turbulenten Rohrstrukturen bei hohen Reynolds Zahlen T2 - GALA - Fachtagung Lasermethoden in der Strömungsmesstechnik, 22. Fachtagung, 9. - 11. September 2014, Karlsruhe Y1 - 2014 SN - 978-3-9816764-0-2 SP - S. 24 PB - GALA CY - Karlsruhe ER - TY - RPRT A1 - Öngüner, Emir A1 - Egbers, Christoph T1 - Experimental Investigation of Turbulent Pipe Flow Structures in High Reynolds Numbers Y1 - 2013 SP - 17 EP - 18 PB - Lehrstuhl Aerodynamik und Strömungslehre CY - Cottbus ER - TY - GEN A1 - Öngüner, Emir A1 - Dittmar, Mirko A1 - Meyer, Peter A1 - Merbold, Sebastian A1 - Egbers, Christoph ED - Egbers, Christoph T1 - Cross-sectional PIV analysis in turbulent pipe flow at high Reynolds number T2 - Experimentelle Strömungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus Y1 - 2016 SN - 978-3-9816764-2-6 SP - S. 31 PB - German Association for Laser Anemometry GALA e.V. CY - Karlsruhe ER - TY - CHAP A1 - Öngüner, Emir A1 - Dittmar, Mirko A1 - Meyer, P. A1 - Zanoun, El-Sayed A1 - Egbers, Christoph T1 - Wall-bounded turbulent Structures in pipe flow based on streamwise and cross-sectional PIV at Re=10^4-10^5 T2 - 11th European Fluid Mechanics Conference, Sept. 12-16, 2016, Sevilla, Spain Y1 - 2016 UR - http://www.efmc11.org/download/com/com_0703_KFARSY.pdf ER - TY - THES A1 - Öngüner, Emir T1 - Experiments in Pipe Flows at Transitional and Very High Reynolds Numbers Y1 - 2018 SN - 978-3-73699-783-7 PB - Göttingen CY - Cuvillier Verlag ER -