@article{HagenkampBlankeDoering2021,
  author    = {Hagenkamp, Markus and Blanke, Tobias and D{\"o}ring, Bernd},
  title     = {Thermoelectric building temperature control: a potential assessment},
  series = {International Journal of Energy and Environmental Engineering},
  volume    = {13},
  journal   = {International Journal of Energy and Environmental Engineering},
  publisher = {Springer},
  address   = {Berlin},
  doi       = {10.1007/s40095-021-00424-x},
  pages     = {241 -- 254},
  year      = {2021},
  abstract  = {This study focuses on thermoelectric elements (TEE) as an alternative for room temperature control. TEE are semi-conductor devices that can provide heating and cooling via a heat pump effect without direct noise emissions and no refrigerant use. An efficiency evaluation of the optimal operating mode is carried out for different numbers of TEE, ambient temperatures, and heating loads. The influence of an additional heat recovery unit on system efficiency and an unevenly distributed heating demand are examined. The results show that TEE can provide heat at a coefficient of performance (COP) greater than one especially for small heating demands and high ambient temperatures. The efficiency increases with the number of elements in the system and is subject to economies of scale. The best COP exceeds six at optimal operating conditions. An additional heat recovery unit proves beneficial for low ambient temperatures and systems with few TEE. It makes COPs above one possible at ambient temperatures below 0 ∘C. The effect increases efficiency by maximal 0.81 (from 1.90 to 2.71) at ambient temperature 5 K below room temperature and heating demand Q˙h=100W but is subject to diseconomies of scale. Thermoelectric technology is a valuable option for electricity-based heat supply and can provide cooling and ventilation functions. A careful system design as well as an additional heat recovery unit significantly benefits the performance. This makes TEE superior to direct current heating systems and competitive to heat pumps for small scale applications with focus on avoiding noise and harmful refrigerants.},
  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{AkimbekovDigelAbdievaetal.2021,
  author    = {Akimbekov, Nuraly S. and Digel, Ilya and Abdieva, Gulzhamal and Ualieva, Perizat and Tastambek, Kuanysh},
  title     = {Lignite biosolubilization and bioconversion by Bacillus sp.: the collation of analytical data},
  series = {Biofuels},
  volume    = {12},
  journal   = {Biofuels},
  number    = {3},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {1759-7277},
  pages     = {247 -- 258},
  year      = {2021},
  abstract  = {The vast metabolic potential of microbes in brown coal (lignite) processing and utilization can greatly contribute to innovative approaches to sustainable production of high-value products from coal. In this study, the multi-faceted and complex coal biosolubilization process by Bacillus sp. RKB 7 isolate from the Kazakhstan coal-mining soil is reported, and the derived products are characterized. Lignite solubilization tests performed for surface and suspension cultures testify to the formation of numerous soluble lignite-derived substances. Almost 24\% of crude lignite (5\% w/v) was solubilized within 14 days under slightly alkaline conditions (pH 8.2). FTIR analysis revealed various functional groups in the obtained biosolubilization products. Analyses of the lignite-derived humic products by UV-Vis and fluorescence spectrometry as well as elemental analysis yielded compatible results indicating the emerging products had a lower molecular weight and degree of aromaticity. Furthermore, XRD and SEM analyses were used to evaluate the biosolubilization processes from mineralogical and microscopic points of view. The findings not only contribute to a deeper understanding of microbe-mineral interactions in coal environments, but also contribute to knowledge of coal biosolubilization and bioconversion with regard to sustainable production of humic substances. The detailed and comprehensive analyses demonstrate the huge biotechnological potential of Bacillus sp. for agricultural productivity and environmental health.},
  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{Bung2021,
  author    = {Bung, Daniel Bernhard},
  title     = {Extreme flooding in Western Germany: some thoughts on hazards, return periods and risk},
  series = {Hydrolink},
  journal   = {Hydrolink},
  number    = {4},
  publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)},
  address   = {Madrid},
  pages     = {108 -- 113},
  year      = {2021},
  abstract  = {The low-pressure system Bernd involved extreme rainfalls in the Western part of Germany in July 2021, resulting in major floods, severe damages and a tremendous number of casualties. Such extreme events are rare and full flood protection can never be ensured with reasonable financial means. But still, this event must be starting point to reconsider current design concepts. This article aims at sharing some thoughts on potential hazards, the selection of return periods and remaining risk with the focus on Germany.},
  language  = {en}
}
@article{BlankeHagenkampDoeringetal.2021,
  author    = {Blanke, Tobias and Hagenkamp, Markus and D{\"o}ring, Bernd and G{\"o}ttsche, Joachim and Reger, Vitali and Kuhnhenne, Markus},
  title     = {Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates},
  series = {Geothermal Energy},
  volume    = {9},
  journal   = {Geothermal Energy},
  number    = {Article number: 19},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {2195-9706},
  doi       = {10.1186/s40517-021-00201-3},
  pages     = {23 Seiten},
  year      = {2021},
  abstract  = {Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellstr{\"o}m's borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54\% of the outer pipe radius for laminar fow and 60\% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth's thermal properties and the fow type. Conclusively, coaxial geothermal probes' design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics.},
  language  = {en}
}
@article{Golland2021,
  author    = {Golland, Alexander},
  title     = {Cookies \& Co. - trotz neuem Gesetz alte Probleme f{\"u}r Website-Betreiber. Anpassung des deutschen Rechts durch das TTDSG an unionsrechtliche Vorgaben zum 1.12.2021},
  series = {NWB Steuer- und Wirtschaftsrecht},
  volume    = {2021},
  journal   = {NWB Steuer- und Wirtschaftsrecht},
  number    = {25},
  publisher = {NWB-Verlag},
  address   = {Herne},
  issn      = {0028-3460},
  pages     = {1818 -- 1825},
  year      = {2021},
  language  = {de}
}
@article{CapitainWagnerHummeletal.2021,
  author    = {Capitain, Charlotte and Wagner, Sebastian and Hummel, Joana and Tippk{\"o}tter, Nils},
  title     = {Investigation of C-N Formation Between Catechols and Chitosan for the Formation of a Strong, Novel Adhesive Mimicking Mussel Adhesion},
  series = {Waste and Biomass Valorization},
  volume    = {12},
  journal   = {Waste and Biomass Valorization},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1877-265X},
  doi       = {10.1007/s12649-020-01110-5},
  pages     = {1761 -- 1779},
  year      = {2021},
  language  = {en}
}
@article{Golland2021,
  author    = {Golland, Alexander},
  title     = {Neuregelungen zum Datenschutz: Ein Update f{\"u}r Website-Betreiber. Reform des Telekommunikations- und Telemedienrechts verabschiedet},
  series = {NWB Rechnungswesen - BBK},
  journal   = {NWB Rechnungswesen - BBK},
  number    = {14},
  isbn      = {0340-9848},
  pages     = {672 -- 674},
  year      = {2021},
  language  = {de}
}
@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}
}