@inproceedings{FleischhakerGebsBudnickietal.2013, author = {Fleischhaker, Robert and Gebs, Raphael and Budnicki, Aleksander and Wolf, M. and Kleinbauer, Jochen and Sutter, Dirk H.}, title = {Compact gigawatt-class sub-picosecond Yb:YAG thin-disk regenerative chirped-pulse amplifier with high average power at up to 800 kHz}, series = {Lasers and electro-optics europe (CLEO EUROPE/IQEC) : International quantum electronics conference : 12 - 16 May 2013, Munich, GE.}, booktitle = {Lasers and electro-optics europe (CLEO EUROPE/IQEC) : International quantum electronics conference : 12 - 16 May 2013, Munich, GE.}, publisher = {IEEE Computer Society}, isbn = {978-1-4799-0593-5}, doi = {10.1109/CLEOE-IQEC.2013.6801054}, pages = {1}, year = {2013}, language = {en} } @article{FingerBraunBil2020, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft}, series = {Journal of Aircraft}, volume = {57}, journal = {Journal of Aircraft}, number = {5}, publisher = {AIAA}, address = {Reston, Va.}, issn = {1533-3868}, doi = {10.2514/1.C035897}, year = {2020}, abstract = {Until electric energy storage systems are ready to allow fully electric aircraft, the combination of combustion engine and electric motor as a hybrid-electric propulsion system seems to be a promising intermediate solution. Consequently, the design space for future aircraft is expanded considerably, as serial hybrid-electric, parallel hybrid-electric, fully electric, and conventional propulsion systems must all be considered. While the best propulsion system depends on a multitude of requirements and considerations, trends can be observed for certain types of aircraft and certain types of missions. This Paper provides insight into some factors that drive a new design toward either conventional or hybrid propulsion systems. General aviation aircraft, regional transport aircraft vertical takeoff and landing air taxis, and unmanned aerial vehicles are chosen as case studies. Typical missions for each class are considered, and the aircraft are analyzed regarding their takeoff mass and primary energy consumption. For these case studies, a high-level approach is chosen, using an initial sizing methodology. Only parallel-hybrid-electric powertrains are taken into account. Aeropropulsive interaction effects are neglected. Results indicate that hybrid-electric propulsion systems should be considered if the propulsion system is sized by short-duration power constraints. However, if the propulsion system is sized by a continuous power requirement, hybrid-electric systems offer hardly any benefit.}, language = {en} } @inproceedings{FingerBraunBil2020, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft}, series = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando}, booktitle = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando}, doi = {10.2514/6.2020-1502}, pages = {15 Seiten}, year = {2020}, language = {en} } @article{HoffschmidtFendJorgensenetal.2003, author = {Hoffschmidt, Bernhard and Fend, Thomas and Jorgensen, Gary and K{\"u}ster, Harald}, title = {Comparative assessment of solar concentrator materials / Fend, Thomas ; Hoffschmidt, Bernhard ; Jorgensen, Gary ; K{\"u}ster, Harald ; Kr{\"u}ger, Dirk ; Pitz-Paal, Robert ; Riebrock, Peter ; Riffelmann, Klaus-J{\"u}rgen}, series = {Solar energy. 74 (2003), H. 2}, journal = {Solar energy. 74 (2003), H. 2}, isbn = {0038-092X}, pages = {149 -- 155}, year = {2003}, language = {en} } @article{HoffschmidtFendJorgensen2002, author = {Hoffschmidt, Bernhard and Fend, Thomas and Jorgensen, Gary}, title = {Comparative assessment of solar concentrator materials / Thomas Fend ; Bernhard Hoffschmidt ; Gary Jorgensen ...}, series = {Renewable energy for local communities of Europe : (toward Rio+10) ; proceedings / EuroSun 2002, the 4th ISES Europe Solar Congress ; Bologna (Italy), 23 - 26 June 2002 / ISES Italia}, journal = {Renewable energy for local communities of Europe : (toward Rio+10) ; proceedings / EuroSun 2002, the 4th ISES Europe Solar Congress ; Bologna (Italy), 23 - 26 June 2002 / ISES Italia}, address = {Bologna}, isbn = {88-900893-0-X}, pages = {paper_125.pdf}, year = {2002}, language = {en} } @article{FoersterHardtdegenUngermanns1995, author = {F{\"o}rster, Arnold and Hardtdegen, Hilde and Ungermanns, C.}, title = {Comparative investigation of electrical and optical characteristics of AlxGa1-xAs/GaAs structures deposited by LP-MOVPE and MBE / H. Hardtdegen ; M. Hollfelder ; C. Ungermanns ... A. F{\"o}rster ...}, series = {Compound semiconductors, 1994 : proceedings of the twenty-first International Symposium on Compound Semiconductors held in San Diego, California, 18 - 22 September, 1994 / ed. by Herb Goronkin ... - (Conference series / Institute of Physics ; 141)}, journal = {Compound semiconductors, 1994 : proceedings of the twenty-first International Symposium on Compound Semiconductors held in San Diego, California, 18 - 22 September, 1994 / ed. by Herb Goronkin ... - (Conference series / Institute of Physics ; 141)}, publisher = {Institute of Physics}, address = {Bristol [u.a.]}, isbn = {0-7503-0226-7}, pages = {81 -- ff.}, year = {1995}, language = {en} } @article{RuppSchulzeKuperjans2018, author = {Rupp, Matthias and Schulze, Sven and Kuperjans, Isabel}, title = {Comparative life cycle analysis of conventional and hybrid heavy-duty trucks}, series = {World electric vehicle journal}, volume = {9}, journal = {World electric vehicle journal}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2032-6653}, doi = {10.3390/wevj9020033}, pages = {Article No. 33}, year = {2018}, abstract = {Heavy-duty trucks are one of the main contributors to greenhouse gas emissions in German traffic. Drivetrain electrification is an option to reduce tailpipe emissions by increasing energy conversion efficiency. To evaluate the vehicle's environmental impacts, it is necessary to consider the entire life cycle. In addition to the daily use, it is also necessary to include the impact of production and disposal. This study presents the comparative life cycle analysis of a parallel hybrid and a conventional heavy-duty truck in long-haul operation. Assuming a uniform vehicle glider, only the differing parts of both drivetrains are taken into account to calculate the environmental burdens of the production. The use phase is modeled by a backward simulation in MATLAB/Simulink considering a characteristic driving cycle. A break-even analysis is conducted to show at what mileage the larger CO2eq emissions due to the production of the electric drivetrain are compensated. The effect of parameter variation on the break-even mileage is investigated by a sensitivity analysis. The results of this analysis show the difference in CO2eq/t km is negative, indicating that the hybrid vehicle releases 4.34 g CO2eq/t km over a lifetime fewer emissions compared to the diesel truck. The break-even analysis also emphasizes the advantages of the electrified drivetrain, compensating the larger emissions generated during production after already a distance of 15,800 km (approx. 1.5 months of operation time). The intersection coordinates, distance, and CO2eq, strongly depend on fuel, emissions for battery production and the driving profile, which lead to nearly all parameter variations showing an increase in break-even distance.}, language = {en} } @article{EngelmannShalabyShashaetal.2021, author = {Engelmann, Ulrich M. and Shalaby, Ahmed and Shasha, Carolyn and Krishnan, Kannan M. and Krause, Hans-Joachim}, title = {Comparative modeling of frequency mixing measurements of magnetic nanoparticles using micromagnetic simulations and Langevin theory}, series = {Nanomaterials}, volume = {11}, journal = {Nanomaterials}, number = {5}, publisher = {MDPI}, address = {Basel}, isbn = {2079-4991}, doi = {10.3390/nano11051257}, pages = {1 -- 16}, year = {2021}, abstract = {Dual frequency magnetic excitation of magnetic nanoparticles (MNP) enables enhanced biosensing applications. This was studied from an experimental and theoretical perspective: nonlinear sum-frequency components of MNP exposed to dual-frequency magnetic excitation were measured as a function of static magnetic offset field. The Langevin model in thermodynamic equilibrium was fitted to the experimental data to derive parameters of the lognormal core size distribution. These parameters were subsequently used as inputs for micromagnetic Monte-Carlo (MC)-simulations. From the hysteresis loops obtained from MC-simulations, sum-frequency components were numerically demodulated and compared with both experiment and Langevin model predictions. From the latter, we derived that approximately 90\% of the frequency mixing magnetic response signal is generated by the largest 10\% of MNP. We therefore suggest that small particles do not contribute to the frequency mixing signal, which is supported by MC-simulation results. Both theoretical approaches describe the experimental signal shapes well, but with notable differences between experiment and micromagnetic simulations. These deviations could result from Brownian relaxations which are, albeit experimentally inhibited, included in MC-simulation, or (yet unconsidered) cluster-effects of MNP, or inaccurately derived input for MC-simulations, because the largest particles dominate the experimental signal but concurrently do not fulfill the precondition of thermodynamic equilibrium required by Langevin theory.}, language = {en} } @inproceedings{Finger2016, author = {Finger, Felix}, title = {Comparative Performance and Benefit Assessment of VTOL and CTOL UAVs}, series = {Deutscher Luft- und Raumfahrtkongress (DLRK) 2016, 13.-15.9.2016}, booktitle = {Deutscher Luft- und Raumfahrtkongress (DLRK) 2016, 13.-15.9.2016}, pages = {10 Seiten}, year = {2016}, language = {en} } @article{SchubertScholl2011, author = {Schubert, Nicole and Scholl, Ingrid}, title = {Comparing GPU-based multi-volume ray casting techniques}, series = {Computer Science - Research and Development}, volume = {26}, journal = {Computer Science - Research and Development}, number = {12}, publisher = {Springer}, address = {Berlin}, isbn = {1865-2042}, pages = {39 -- 50}, year = {2011}, language = {en} }