@inproceedings{HorikawaOkadaYamaguchietal.2021,
  author    = {Horikawa, Atsushi and Okada, Kunio and Yamaguchi, Masato and Aoki, Shigeki and Wirsum, Manfred and Funke, Harald and Kusterer, Karsten},
  title     = {Combustor development and engine demonstration of micro-mix hydrogen combustion applied to M1A-17 gas turbine},
  series = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3B: Combustion, Fuels, and Emissions},
  booktitle = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3B: Combustion, Fuels, and Emissions},
  doi       = {10.1115/GT2021-59666},
  pages     = {13 Seiten},
  year      = {2021},
  abstract  = {Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for a future hydrogen society. These projects comprise the complete hydrogen cycle, including the production of hydrogen gas, the refinement and liquefaction for transportation and storage, and finally the utilization in a gas turbine for electricity and heat supply. Within the development of the hydrogen gas turbine, the key technology is stable and low NOx hydrogen combustion, namely the Dry Low NOx (DLN) hydrogen combustion. KHI, Aachen University of Applied Science, and B\&B-AGEMA have investigated the possibility of low NOx micro-mix hydrogen combustion and its application to an industrial gas turbine combustor. From 2014 to 2018, KHI developed a DLN hydrogen combustor for a 2MW class industrial gas turbine with the micro-mix technology. Thereby, the ignition performance, the flame stability for equivalent rotational speed, and higher load conditions were investigated. NOx emission values were kept about half of the Air Pollution Control Law in Japan: 84ppm (O2-15\%). Hereby, the elementary combustor development was completed. From May 2020, KHI started the engine demonstration operation by using an M1A-17 gas turbine with a co-generation system located in the hydrogen-fueled power generation plant in Kobe City, Japan. During the first engine demonstration tests, adjustments of engine starting and load control with fuel staging were investigated. On 21st May, the electrical power output reached 1,635 kW, which corresponds to 100\% load (ambient temperature 20 °C), and thereby NOx emissions of 65 ppm (O2-15, 60 RH\%) were verified. Here, for the first time, a DLN hydrogen-fueled gas turbine successfully generated power and heat.},
  language  = {en}
}
@inproceedings{KronigerHorikawaFunkeetal.2021,
  author    = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska and Kishimoto, Tsuyoshi and Okada, Koichi},
  title     = {Experimental and numerical investigation on the effect of pressure on micromix hydrogen combustion},
  series = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3A: Combustion, Fuels, and Emissions},
  booktitle = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3A: Combustion, Fuels, and Emissions},
  publisher = {ASME},
  address   = {New York, NY},
  doi       = {10.1115/GT2021-58926},
  pages     = {11 Seiten},
  year      = {2021},
  abstract  = {The micromix (MMX) combustion concept is a DLN gas turbine combustion technology designed for high hydrogen content fuels. Multiple non-premixed miniaturized flames based on jet in cross-flow (JICF) are inherently safe against flashback and ensure a stable operation in various operative conditions. The objective of this paper is to investigate the influence of pressure on the micromix flame with focus on the flame initiation point and the NOx emissions. A numerical model based on a steady RANS approach and the Complex Chemistry model with relevant reactions of the GRI 3.0 mechanism is used to predict the reactive flow and NOx emissions at various pressure conditions. Regarding the turbulence-chemical interaction, the Laminar Flame Concept (LFC) and the Eddy Dissipation Concept (EDC) are compared. The numerical results are validated against experimental results that have been acquired at a high pressure test facility for industrial can-type gas turbine combustors with regard to flame initiation and NOx emissions. The numerical approach is adequate to predict the flame initiation point and NOx emission trends. Interestingly, the flame shifts its initiation point during the pressure increase in upstream direction, whereby the flame attachment shifts from anchoring behind a downstream located bluff body towards anchoring directly at the hydrogen jet. The LFC predicts this change and the NOx emissions more accurately than the EDC. The resulting NOx correlation regarding the pressure is similar to a non-premixed type combustion configuration.},
  language  = {en}
}
@article{HeiligersSchoutetensDachwald2021,
  author    = {Heiligers, Jeannette and Schoutetens, Frederic and Dachwald, Bernd},
  title     = {Photon-sail equilibria in the alpha centauri system},
  series = {Journal of Guidance, Control, and Dynamics},
  volume    = {44},
  journal   = {Journal of Guidance, Control, and Dynamics},
  number    = {5},
  issn      = {1533-3884},
  doi       = {10.2514/1.G005446},
  pages     = {1053 -- 1061},
  year      = {2021},
  language  = {en}
}
@article{GermanMikuckiWelchetal.2021,
  author    = {German, Laura and Mikucki, Jill A. and Welch, Susan A. and Welch, Kathleen A. and Lutton, Anthony and Dachwald, Bernd and Kowalski, Julia and Heinen, Dirk and Feldmann, Marco and Francke, Gero and Espe, Clemens and Lyons, W. Berry},
  title     = {Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry},
  series = {International Journal of Environmental Analytical Chemistry},
  volume    = {101},
  journal   = {International Journal of Environmental Analytical Chemistry},
  number    = {15},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {0306-7319},
  doi       = {10.1080/03067319.2019.1704750},
  pages     = {2654 -- 2667},
  year      = {2021},
  abstract  = {Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe's sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2-+NO3- from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica.},
  language  = {en}
}
@article{SpietzSproewitzSeefeldtetal.2021,
  author    = {Spietz, Peter and Spr{\"o}witz, Tom and Seefeldt, Patric and Grundmann, Jan Thimo and Jahnke, Rico and Mikschl, Tobias and Mikulz, Eugen and Montenegro, Sergio and Reershemius, Siebo and Renger, Thomas and Ruffer, Michael and Sasaki, Kaname and Sznajder, Maciej and T{\´o}th, Norbert and Ceriotti, Matteo and Dachwald, Bernd and Macdonald, Malcolm and McInnes, Colin and Seboldt, Wolfgang and Quantius, Dominik and Bauer, Waldemar and Wiedemann, Carsten and Grimm, Christian D. and Hercik, David and Ho, Tra-Mi and Lange, Caroline and Schmitz, Nicole},
  title     = {Paths not taken - The Gossamer roadmap's other options},
  series = {Advances in Space Research},
  volume    = {67},
  journal   = {Advances in Space Research},
  number    = {9},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  doi       = {10.1016/j.asr.2021.01.044},
  pages     = {2912 -- 2956},
  year      = {2021},
  language  = {en}
}
@article{KezerashviliDachwald2021,
  author    = {Kezerashvili, Roman Ya and Dachwald, Bernd},
  title     = {Preface: Solar sailing: Concepts, technology, and missions II},
  series = {Advances in Space Research},
  volume    = {67},
  journal   = {Advances in Space Research},
  number    = {9},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  doi       = {10.1016/j.asr.2021.01.037},
  pages     = {2559 -- 2560},
  year      = {2021},
  language  = {en}
}
@article{Maurischat2021,
  author    = {Maurischat, Andreas},
  title     = {Algebraic independence of the Carlitz period and its hyperderivatives},
  pages     = {1 -- 12},
  year      = {2021},
  language  = {en}
}
@article{BohndickBosseJaenschetal.2021,
  author    = {Bohndick, Carla and Bosse, Elke and J{\"a}nsch, Vanessa K. and Barnat, Miriam},
  title     = {How different diversity factors affect the perception of first-year requirements in higher education},
  series = {Frontline Learning Research},
  volume    = {9},
  journal   = {Frontline Learning Research},
  number    = {2},
  publisher = {EARLI},
  issn      = {2295-3159},
  doi       = {10.14786/flr.v9i2.667},
  pages     = {78 -- 95},
  year      = {2021},
  abstract  = {In the light of growing university entry rates, higher education institutions not only serve larger numbers of students, but also seek to meet first-year students' ever more diverse needs. Yet to inform universities how to support the transition to higher education, research only offers limited insights. Current studies tend to either focus on the individual factors that affect student success or they highlight students' social background and their educational biography in order to examine the achievement of selected, non-traditional groups of students. Both lines of research appear to lack integration and often fail to take organisational diversity into account, such as different types of higher education institutions or degree programmes. For a more comprehensive understanding of student diversity, the present study includes individual, social and organisational factors. To gain insights into their role for the transition to higher education, we examine how the different factors affect the students' perception of the formal and informal requirements of the first year as more or less difficult to cope with. As the perceived requirements result from both the characteristics of the students and the institutional context, they allow to investigate transition at the interface of the micro and the meso level of higher education. Latent profile analyses revealed that there are no profiles with complex patterns of perception of the first-year requirements, but the identified groups rather differ in the overall level of perceived challenges. Moreover, SEM indicates that the differences in the perception largely depend on the individual factors self-efficacy and volition.},
  language  = {en}
}
@article{GoettenHavermannBraunetal.2021,
  author    = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees},
  title     = {Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach},
  series = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021},
  journal   = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021},
  publisher = {AIAA},
  address   = {Reston, Va.},
  doi       = {10.2514/6.2021-1535},
  pages     = {1 -- 12},
  year      = {2021},
  language  = {en}
}
@inproceedings{FunkeBeckmannKeinzetal.2021,
  author    = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Horikawa, Atsushi},
  title     = {30 years of dry low NOx micromix combustor research for hydrogen-rich fuels: an overview of past and present activities},
  series = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 4B: Combustion, Fuels, and Emissions},
  booktitle = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 4B: Combustion, Fuels, and Emissions},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {978-0-7918-8413-3},
  doi       = {10.1115/GT2020-16328},
  pages     = {14 Seiten},
  year      = {2021},
  abstract  = {The paper presents an overview of the past and present of low-emission combustor research with hydrogen-rich fuels at Aachen University of Applied Sciences. In 1990, AcUAS started developing the Dry-Low-NOx Micromix combustion technology. Micromix reduces NOx emissions using jet-in-crossflow mixing of multiple miniaturized fuel jets and combustor air with an inherent safety against flashback. At first, pure hydrogen as fuel was investigated with lab-scale applications. Later, Micromix prototypes were developed for the use in an industrial gas turbine Honeywell/Garrett GTCP-36-300, proving low NOx characteristics during real gas turbine operation, accompanied by the successful definition of safety laws and control system modifications. Further, the Micromix was optimized for the use in annular and can combustors as well as for fuel-flexibility with hydrogen-methane-mixtures and hydrogen-rich syngas qualities by means of extensive experimental and numerical simulations. In 2020, the latest Micromix application will be demonstrated in a commercial 2 MW-class gas turbine can-combustor with full-scale engine operation. The paper discusses the advances in Micromix research over the last three decades.},
  language  = {en}
}