@article{Vollmer2025, author = {Vollmer, Michael}, title = {Nachtsicht ins All mit dem bloßen Auge: Sag mir, wie weit die Sterne steh'n}, series = {Physik in unserer Zeit}, volume = {2025}, journal = {Physik in unserer Zeit}, publisher = {Wiley}, doi = {10.1002/piuz.202501751}, pages = {2 -- 10}, year = {2025}, language = {de} } @article{Vollmer2025, author = {Vollmer, Michael}, title = {Naked eye celestial objects and phenomena: how far can we see at night?}, series = {European Journal of Physics}, volume = {46}, journal = {European Journal of Physics}, number = {3}, publisher = {IOP Science}, doi = {10.1088/1361-6404/adbf74}, pages = {18}, year = {2025}, abstract = {How far can we see with the naked eye at night? Many celestial objects like stars and galaxies as well as transient phenomena such as comets and supernovae can be observed in the night sky. We discuss the furthest distances of such objects and phenomena observable with the naked eye during the night-time for Earth-bound observers. The physics of night-time visual ranges differs from that of daytime observations because human vision shifts from cones to rods. In addition, mostly point sources are observed due to the large distances involved. Whether celestial objects and phenomena can be detected depends on the contrast of their radiation and the background sky luminance. We present a concise overview of how far we can see at night by first discussing the effects of the Earth's atmosphere. This includes attenuation of transmitted radiation as well as its role as a source of background radiation. Disregarding the attenuation of light due to interstellar and intergalactic dust, simple maximum night-time visual range estimates are based on the inverse square law, which can be easily verified by laboratory and demonstration experiments. From the respective calculations, we find that individual stars within the Milky Way galaxy of up to 15 000 light years are observable. Even further away are observable galaxies with several billion stars. The Andromeda galaxy can be observed with the naked eye at a distance of around 2.5 million light years. Similarly, the observability of supernovae also allows a visual range beyond the Milky Way galaxy. Finally, gamma ray bursts as the most energetic events in the universe are discussed concerning naked eye observations.}, language = {en} } @article{RedkaMukhinGrishkanichetal.2019, author = {Redka, D. and Mukhin, N. and Grishkanich, A. and Terukov, E. and Hirsch, S{\"o}ren and Ignateva, L.}, title = {NdYAG surface modification of ZnO for solar cells}, series = {Journal of Physics: Conference Series}, volume = {1410}, journal = {Journal of Physics: Conference Series}, publisher = {IOP Science}, doi = {10.1088/1742-6596/1410/1/012106}, pages = {012106}, year = {2019}, language = {en} } @inproceedings{VollmerShaw2019, author = {Vollmer, Michael and Shaw, Joseph A.}, title = {Near infrared photography of atmospheric optical phenomena}, series = {Fifteenth Conference on Education and Training in Optics and Photonics: ETOP 2019}, booktitle = {Fifteenth Conference on Education and Training in Optics and Photonics: ETOP 2019}, address = {Quebec City, Quebec, Canada}, doi = {10.1117/12.2523165}, pages = {111431P-1 -- 111431P-6}, year = {2019}, language = {en} } @article{WehlandCorydonGonzalezTorresetal.2025, author = {Wehland, Markus and Corydon, Thomas J. and Gonz{\´a}lez-Torres, Luis Fernando and Abdelfattah, Fatima and Sahana, Jayashree and Schulz, Herbert and Mushunuri, Ashwini and Burenkova, Hanna and Wuest, Simon L. and Kr{\"u}ger, Marcus and Kraus, Armin and Grimm, Daniela}, title = {New Knowledge About Tissue Engineering Under Microgravity Conditions in Space and on Earth}, series = {International Journal of Molecular Sciences}, volume = {27}, journal = {International Journal of Molecular Sciences}, number = {1}, publisher = {MDPI}, doi = {10.3390/ijms27010341}, year = {2025}, abstract = {Microgravity (µg)-generated three-dimensional (3D) multicellular aggregates can serve as models of tissue and disease development. They are relevant in the fields of cancer and in vitro metastasis or regenerative medicine (tissue engineering). Driven by the 3R concept—replacement, reduction, and refinement of animal testing—µg-exposure of human cells represents a new alternative method that avoids animal experiments entirely. New Approach Methodologies (NAMs) are used in biomedical research, pharmacology, toxicology, cancer research, radiotherapy, and translational regenerative medicine. Various types of human cells grow as 3D spheroids or organoids when exposed to µg-conditions provided by µg simulating instruments on Earth. Examples for such µg-simulators are the Rotating Wall Vessel, the Random Positioning Machine, and the 2D or 3D clinostat. This review summarizes the most recent literature focusing on µg-engineered tissues. We are discussing all reports examining different tumor cell types from breast, lung, thyroid, prostate, and gastrointestinal cancers. Moreover, we are focusing on µg-generated spheroids and organoids derived from healthy cells like chondrocytes, stem cells, bone cells, endothelial cells, and cardiovascular cells. The obtained data from NAMs and µg-experiments clearly imply that they can support translational medicine on Earth.}, language = {en} } @article{SchwarzSchwarzCreutzburg2020, author = {Schwarz, Franziska and Schwarz, Klaus and Creutzburg, Reiner}, title = {New Methodology and Checklist of Wi-Fi Connected and App-Controlled IoT-Based Consumer Market Smart Home Devices}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2020.3.MOBMU-276}, pages = {276-1 -- 276-15}, year = {2020}, language = {en} } @techreport{KybaArroyoDegenetal.2024, author = {Kyba, Christopher C.M. and Arroyo, Hector Linares and Degen, Tobias and Abascal, Angela and Simoneau, Alexandre and Kuffer, Monika and H{\"o}lker, Franz and Aub{\´e}, Martin and Walczak, Ken and Espey, Brian R. and de Miguel, Alejandro S{\´a}nchez and Jechow, Andreas and Gyuk, Geza}, title = {Night Watch Mission Description Document}, publisher = {GFZ German Research Centre for Geosciences}, address = {Potsdam}, doi = {10.48440/gfz.b103-24052}, pages = {1 -- 156}, year = {2024}, abstract = {This is the Mission Description Document (MDD) for a future Earth observation satellite mission addressing visible band observations of nighttime lights. The mission driving science applications are for the remote sensing of electricity, energy, and ecological impacts via the observation of artificial light. The MDD covers the mission requirements justification from the high-level scientific objectives and societal benefits to measurement requirements at product level 1b, i.e. radiances at the top of the atmosphere. In providing justification for the individual requirements and their traceability to scientific objectives and societal challenges, we address Scientific Readiness Levels 1 to 3. The MDD is the outcome of the European Space Agency New Earth Observation Mission Ideas project "Night Watch". The Task Reports (TR) from the project are appended to the MDD, and are authored by the same group as the MDD itself.}, language = {en} } @article{KalinkatJechowSchroeretal.2025, author = {Kalinkat, Gregor and Jechow, Andreas and Schroer, Sibylle and H{\"o}lker, Franz}, title = {Nocturnal pandas: conservation umbrellas protecting nocturnal biodiversity}, series = {Trends in Ecology \& Evolution}, volume = {40}, journal = {Trends in Ecology \& Evolution}, number = {8}, publisher = {Elsevier}, doi = {10.1016/j.tree.2025.05.006}, pages = {736 -- 739}, year = {2025}, abstract = {Light pollution is an emerging ecological threat. To mitigate its negative consequences, creative inter- and transdisciplinary solutions and societal interactions are needed. To this end, we introduce nocturnal umbrella species representative of light-sensitive biodiversity whose protection will safeguard vital ecosystem services and a wide range of co-occurring species.}, language = {en} } @misc{BoudnitskiEdel1998, author = {Boudnitski, Grigori and Edel, Karl-Otto}, title = {Oberfl{\"a}chendefekte im Scheibenbereich: Abschlußbericht zum DFG-Projekt}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:522-opus-193}, year = {1998}, abstract = {Im Rahmen des DFG-Schwerpunktprogramms „Systemdynamik und Langzeitverhalten von Fahrwerk, Gleis und Untergrund" wurde das Thema „Analyse und Bewertung des Verhaltens rißartiger Oberfl{\"a}chendefekte im Scheibenbereich von Eisenbahnvollr{\"a}dern mit den Metho-den der probabilistischen Bruchmechanik" behandelt. Der Abschlußbericht zu dem Projekt, das im Zeitraum von 1995 bis 1997 von der Deutschen Forschungsgemeinschaft gef{\"o}rdert wurde, ist an der Fachhochschule in Brandenburg an der Havel im April 1998 fertiggestellt worden. Wiederverwendbare Eisenbahnvollr{\"a}der von G{\"u}terwagen, die aus dem Vollradstahl BV1 her-gestellt wurden, zeigen in einigen F{\"a}llen das Vorhandensein von Oberfl{\"a}chenfehlern in Form von {\"U}berwalzungen im Bereich der Radscheibe. Analysiert und bewertet wurde im Interesse der Betriebssicherheit das Dauerfestigkeitsverhalten sowie das Rißwachstumsverhalten von Erm{\"u}dungsrissen, die von solchen {\"U}berwalzungen ausgehen. Um den Einfluß der Streubreite der wesentlichen Parameter der Beanspruchung und der Beanspruchbarkeit auf die Dauerfes-tigkeit und die zyklische Rißausbreitung erfassen und die f{\"u}r die Betriebssicherheit erforderli-chen zul{\"a}ssigen Riß- bzw. Defektgr{\"o}ßen festlegen zu k{\"o}nnen, sind die bruchmechanischen Analysen als Monte-Carlo-Simulation gestaltet worden. Ziel der Analysen war es, zul{\"a}ssige Defektgr{\"o}ßen f{\"u}r die zerst{\"o}rungsfreie Bauteilpr{\"u}fung bei Gew{\"a}hrleistung der Dauerfestigkeit der mit {\"U}berwalzungen behafteten Vollr{\"a}der auf wissenschaftlich fundierter Basis abzuleiten, da praktische Erfahrungen mit derartigen Defekten nicht vorlagen.}, subject = {Eisenbahn ; Fahrwerk ; Werkstoffkunde ; Besch{\"a}digung ; Bruchmechanik}, language = {de} } @unpublished{Frosch2019, author = {Frosch, Katharina}, title = {Open Design of HRM Instruments: new perspectives on people management in SMEs}, pages = {1 -- 35}, year = {2019}, abstract = {When it comes to human resource management (HRM), small and medium-sized enterprises (SMEs) primarily rely on informal approaches. Thereby, HR practitioners often listen to their guts feeling instead of using more systematic HR practices that are, as research evidence shows, more effective for attracting, motivating and retaining talented staff. This paper elaborates on the question how SMEs may profit from the design and implementation of evidence-based, systematic HRM instruments. The analysis focuses on the antecedents of the so called science-practitioner gap in HRM and why it is even more pronounced in SMEs as compared to larger companies. As a conclusion, we find that SMEs need to design HRM instruments that are systematic and evidence-based in their approach, but can be used by HR practitioners on an intuitive basis without ex ante training or cumbersome formal procedures. However, designing HRM instruments based on a so-called "walk-up-and-use" approach means beating new paths. Given the scarce resources for people management in SMEs, such innovative HRM instruments cannot be developed by a single SME alone. Therefore, the paradigm of open cooperation as it has been successfully applied in open source software (OSS) development is evaluated , in particular whether it can be transferred on the design of HRM instruments that take into account the specific needs of SMEs. First of all, we conceptualize a general framework how HR practitioners from SMEs and HR experts from business and academia can jointly develop Open HRM instruments. Then we discuss the social side of Open HRM, in particular why someone should contribute to Open HRM without receiving immediate profits, how to ensure the quality of openly developed HRM instruments and other gov-ernance issues. As a conclusion, we find that-despite a number of technical and social challenges that have to be overcome-Open HRM has a great potential in order to open up evidence-based HRM for SMEs.}, language = {de} }