TY - JOUR A1 - Edel, Karl-Otto T1 - Der Bologna Prozess : Anmerkung zur rechtlichen Gestaltung und Umsetzung JF - Die neue Hochschule N2 - Die Bologna-Deklaration ist eine politische Willensbekundung der Unterzeichner, die durch die informelle Versammlung der europäischen Wissenschaftsminister vorangetrieben wird. Wegen des fehlenden Rechtscharakters der Deklaration gibt es keine rechtliche Verpflichtung, die vereinbarten Ziele umzusetzen, keine Rechtsansprüche oder Verpflichtungen zwischen den Teilnehmerländern untereinander, insbesondere auch keinen Anspruch auf Anerkennung der Studien und Abschlüsse im Ausland. Die platte Übernahme der US-amerikanischen Abschlußbezeichnungen des gestuften Studiums stellt einen Bruch mit den Traditionen der deutschen Hochschulen dar und steht im offenen Widerspruch zu der im Bologna-Abkommen feierlich unterzeichneten Achtung vor der eigenen Kultur, Sprache und Tradition. Während die durch das gestufte Studiensystem charakterisierten angelsächsischen Länder von ihrem traditionellen System Abschied nehmen und – teilweise expressis verbis – auf das einhundertjährige bewährte deutsche Diplomstudium zugehen, verordnen Politiker unseren Hochschulen eine Roßkur mit höchst fatalen Folgen für die Zukunft. Diesen Bestrebungen sollte Einhalt geboten werden, damit in Ruhe und mit Überlegung eine inhaltliche Reform begonnen werden kann, die die Stärken unseres Bildungssystems wieder innerhalb Deutschlands und weltweit zur Geltung bringt, anstatt es auf das niedrigste bekannte Niveau des Bachelors zu reduzieren. KW - Bologna-Prozess Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus-347 VL - 45 IS - 6 SP - 26 EP - 29 ER - TY - JOUR A1 - Edel, Karl-Otto T1 - Die Auswirkungen des Bologna-Prozesses und seiner Instrumentalisierung auf das akademische Qualifikationsniveau N2 - Aus einer Gegenüberstellung der Absolventenzahlen der jeweiligen Abschlüsse in Deutschland und den USA ergibt sich der Schluß, daß durch die Einführung der Bologna-Abschlüsse zusammen mit den konkreten politischen Zielvorgaben das akademische Bildungsniveau in Deutschland in einem für ein Industrieland gefährlichem Maße gesenkt werden wird. KW - Bologna-Prozess ; Auswirkung Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus-356 VL - 46 IS - 2/3 SP - 16 EP - 18 ER - TY - JOUR A1 - Edel, Karl-Otto T1 - Ausländische Erfahrungen mit der Studienstrukturreform JF - Die neue Hochschule N2 - Trotz seiner dringenden Reformbedürftigkeit ist auch heute noch das deutsche Diplomstudium grundsätzlich erfolgreich und erneuerungsfähig. In Kenntnis der neueren internationalen Entwicklungen in Dänemark, Finnland, Griechenland, Großbritannien, den USA und Indien ist es vorschnell und nicht zu akzeptieren, das seit mehr als einem Jahrhundert existierende deutsche Hochschuldiplom zum Auslaufmodell zu erklären und die akademische Bildung ausschließlich auf das angeblich international – von wem auch immer – anerkannte Bachelor-Master-System umzustrukturieren. KW - Studienreform KW - Bachelorstudium KW - Masterstudium Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus-368 VL - 46 IS - 4 SP - 22 EP - 27 ER - TY - JOUR A1 - Mukhin, Nikolay A1 - Konoplev, Georgii A1 - Oseev, Aleksandr A1 - Schmidt, Marc-Peter A1 - Stepanova, Oksana A1 - Kozyrev, Andrey A1 - Dmitriev, Alexander A1 - Hirsch, Soeren T1 - Label-Free Protein Detection by Micro-Acoustic Biosensor Coupled with Electrical Field Sorting. Theoretical Study in Urine Models JF - Sensors KW - acoustic liquid sensor KW - shear bulk acoustic resonator KW - biosensor KW - structured sensor interface KW - electrical field manipulation KW - urine proteins characterisation Y1 - 2021 U6 - https://doi.org/10.3390/s21072555 VL - 21 IS - 7 SP - 2555 PB - MDPI ER - TY - JOUR A1 - Vollmer, Michael T1 - Below the horizon-the physics of extreme visual ranges JF - Applied Optics Y1 - 2020 U6 - https://doi.org/10.1364/AO.390654 VL - 59 IS - 21 SP - F11 EP - F19 PB - Optica Publishing Group ER - TY - JOUR A1 - Tumarkin, Andrey A1 - Tyurnina, Natalya A1 - Tyurnina, Zoya A1 - Mukhin, Nikolay A1 - Sinelshchikova, Olga A1 - Gagarin, Alexander A1 - Sviridov, Sergey A1 - Drozdovsky, Andrey A1 - Sapego, Eugeny A1 - Mylnikov, Ivan T1 - Barium-Strontium Titanate/Porous Glass Structures for Microwave Applications JF - Materials KW - glass-ceramic structures KW - filling of porous material KW - microwave KW - barium-strontium titanate Y1 - 2020 U6 - https://doi.org/10.3390/ma13245639 VL - 13 IS - 24 PB - MDPI ER - TY - JOUR A1 - Rudenko, Maryia A1 - Gaponenko, Nikolai A1 - Litvinov, Vladimir A1 - Ermachikhin, Alexander A1 - Chubenko, Eugene A1 - Borisenko, Victor A1 - Mukhin, Nikolay A1 - Radyush, Yuriy A1 - Tumarkin, Andrey A1 - Gagarin, Alexander T1 - Structural Dependent Eu3+ Luminescence, Photoelectric and Hysteresis Effects in Porous Strontium Titanate JF - Materials KW - europium luminescence KW - poporous film KW - strontium titanate KW - resistive switching hysteresis KW - photocurrent Y1 - 2020 U6 - https://doi.org/10.3390/ma13245767 VL - 13 IS - 24 PB - MDPI ER - TY - JOUR A1 - Regehly, Martin A1 - Hecht, Stefan T1 - Auf dem Weg zum Replikator BT - volumetrischer 3D-Druck JF - Physik in unserer Zeit KW - Xolographie KW - 3D-Druck KW - Additive Fertigung KW - volumetrisch KW - Photoschalter KW - Lichtschnitt Y1 - 2022 U6 - https://doi.org/10.1002/piuz.202201637 SN - 1521-3943 SN - 1521-3943 (eISSN) VL - 53 IS - 3 SP - 125 EP - 131 PB - Wiley-VCH GmbH ER - TY - JOUR A1 - Hirsch, Sören A1 - Schmidt, Marc-Peter A1 - Oseev, Aleksandr A1 - Engel, Christian A1 - Brose, Andreas A1 - Schmidt, Bertram T1 - Flexible free-standing SU-8 microfluidic impedancespectroscopy sensor for 3-D molded interconnectdevices application JF - Journal of Sensors and Sensor Systems Y1 - 2016 U6 - https://doi.org/10.5194/jsss-5-55-2016 VL - 5 IS - 1 SP - 55 EP - 61 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - Unsichtbares sichtbar gemacht: Infrarotkameras für Smartphones JF - Physik in unserer Zeit KW - Infrarotkamera KW - Smartphone KW - Temperaturmessung KW - räumliche Auflösung KW - qualitative Analyse KW - quantitative Analyse Y1 - 2020 U6 - https://doi.org/https://doi.org/10.1002/piuz.201901551 VL - 51 IS - 1 SP - 29 EP - 35 PB - Wiley-VCH ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - Wenn Licht die Biege macht JF - Physik in unserer Zeit Y1 - 2020 U6 - https://doi.org/https://doi.org/10.1002/piuz.202001569 VL - 51 IS - 1 SP - 46 EP - 47 PB - Wiley-VCH ER - TY - JOUR A1 - Fachet, Melanie A1 - Witte, Carina A1 - Flassig, Robert J. A1 - Rihko-Struckmann, Liisa K. A1 - McKie-Krisberg, Zaid A1 - Polle, Jürgen E. W. A1 - Sundmacher, Kai T1 - Reconstruction and analysis of a carbon-core metabolic network for Dunaliella salina JF - BMC Bioinformatics KW - Metabolic network reconstruction KW - Central carbon metabolism KW - Flux balance analysis KW - Dunaliella salina Y1 - 2020 U6 - https://doi.org/10.1186/s12859-019-3325-0 VL - 21 IS - 1 PB - BioMed Central ER - TY - JOUR A1 - Giesler, Jasper A1 - Pesch, Georg R. A1 - Weirauch, Laura A1 - Schmidt, Marc-Peter A1 - Thöming, Jorg A1 - Baune, Michae T1 - Polarizability-Dependent Sorting of Microparticles Using Continuous-Flow Dielectrophoretic Chromatography with a Frequency Modulation Method JF - Micromachines Y1 - 2020 U6 - https://doi.org/10.3390/mi11010038 VL - 11 IS - 1 SP - 38 PB - MDPI ER - TY - JOUR A1 - Vollmer, Michael T1 - Gefrierende Gewässer JF - Physik in unserer Zeit KW - Gefrieren von Seen KW - Eiswachstumsmodell KW - Konvektion KW - Strahlung KW - Stefan-Boltzmann-Gesetz KW - Wärmeleitfähigkeit KW - optische Eisdickenmessung Y1 - 2021 U6 - https://doi.org/10.1002/piuz.202001589 VL - 52 IS - 1 SP - 19 EP - 25 PB - Wiley-Blackwell ER - TY - JOUR A1 - Agafonova, D. S. A1 - Kozyrev, A. B. A1 - Mukhin, N. V. A1 - Red'ka, D. N. A1 - Elanskaya, G. K. A1 - Rudenko, M. V. A1 - Oseev, A. A1 - Hirsch, Sören T1 - Impurity Phases in Polycrystalline Films of Ferroelectric Oxides of the Perovskite-Type on the Basis of Bi2SrTa2O9 and Pb(Zr,Ti)O3 JF - Glass Physics and Chemistry KW - complex oxides KW - perovskites KW - heterophase films KW - nonstoichiometry Y1 - 2018 U6 - https://doi.org/10.1134/S1087659618010029 VL - 44 IS - 1 SP - 15 EP - 20 ER - TY - JOUR A1 - Ptashnik, Sergey V. A1 - Mikhailov, Anatoliy K. A1 - Yastrebov, Alexander V. A1 - Petrov, Peter K. A1 - Liu, Wei A1 - McN Alford, Neil A1 - Hirsch, Soeren A1 - Kozyrev, Andrey B. T1 - Ferroelectric thin film acoustic devices with electrical multiband switching ability JF - Scientific Reports KW - Electrical and electronic engineering KW - Electronic and spintronic devices Y1 - 2017 U6 - https://doi.org/10.1038/s41598-017-14895-8 VL - 7 IS - 15289 ER - TY - JOUR A1 - Oseev, Aleksandr A1 - Lucklum, Ralf A1 - Zubtsov, Mikhail A1 - Schmidt, Marc-Peter A1 - Mukhin, Nikolay V. A1 - Hirsch, Soeren T1 - SAW-Based Phononic Crystal Microfluidic Sensor—Microscale Realization of Velocimetry Approaches for Integrated Analytical Platform Applications JF - Sensors KW - phononic crystal KW - liquid sensor KW - ultrasonic velocimetry KW - μTAS Y1 - 2017 U6 - https://doi.org/10.3390/s17102187 VL - 17 IS - 10 SP - 2187 ER - TY - JOUR A1 - Kutia, Mykhailo A1 - Mukhin, Nikolay A1 - Petrova, Hanna A1 - Oseev, Aleksandr A1 - Bakhchova, Liubov A1 - Schmidt, Marc-Peter A1 - Aman, Alexander A1 - Palis, Stefan A1 - Tarasov, Sergey A1 - Hirsch, Soeren T1 - Sensor for the evaluation of dielectric properties of sulfur-containing heteroatomic hydrocarbon compounds in petroleum based liquids at a microfluidic scale JF - AIP Advances KW - Microfluidics KW - Chemical compounds KW - Petroleum KW - Dielectric spectroscopy KW - Microfluidic devices KW - Gasoline KW - Dielectric properties Y1 - 2020 U6 - https://doi.org/10.1063/1.5141482 VL - 10 IS - 2 SP - 025006 PB - American Institute of Physics ER - TY - JOUR A1 - Kurachkina, Margarita A1 - Konshina, Elena A1 - Oseev, Aleksandr A1 - Hirsch, Sören T1 - Hybrid structures based on gold nanoparticles and semiconductor quantum dots for biosensor applications JF - Nanotechnology Science and Applications Y1 - 2018 U6 - https://doi.org/10.2147/nsa.s155045 VL - 11 SP - 15 EP - 21 ER - TY - JOUR A1 - Mukhin, N.V. A1 - Redka, D. N. A1 - Tarasov, S. A. A1 - Oseev, A. Yu. A1 - Hirsch, Sören T1 - Two-Dimensional Periodic Composite Structure for Acoustic Sensor of Volumetric Properties of Liquids T1 - Dvumernaja periodičeskaja kompozitnaja struktura dlja akustičeskogo datčika ob"emnych svojstv židkosti JF - Journal of the Russian Universities. Radioelectronics JF - Izvestija vysšich učebnych zavedenij Rossii : radioėlektronika Y1 - 2018 U6 - https://doi.org/10.32603/1993-8985-2018-21-1-56-63 IS - 1 SP - 56 EP - 63 ER - TY - JOUR A1 - Widjaja, Agnes S. N. A1 - Löwe, Katharina A1 - Costa, Felipe Salerno T1 - Design and simulation of a concentrated solar thermal system with an integrated concrete storage for continuous heat supply JF - Energy Procedia KW - Concentrated solar thermal system KW - process heat supply KW - Concrete storage KW - Economic feasibility Study Y1 - 2018 U6 - https://doi.org/10.1016/j.egypro.2018.11.062 VL - 155 SP - 121 EP - 135 ER - TY - JOUR A1 - Kraska, Martin T1 - Meclib: Dynamic and Interactive Figures in STACK Questions Made Easy JF - International Journal of Emerging Technologies in Learning (iJET) N2 - Making and interpretation of drawings and schematics is an important skill to be developed in engineering education. The question type STACK in the Moodle learning management system combined with the interactive graphics library JSXGraph has a great potential for implementation of e-learning resources addressing these skills in formative and summative settings. The authoring process of such materials is complex due to multiple markup and programming languages like HTML, LaTeX, Maxima and JavaScript (JS) being involved. The Meclib concept mitigates this complexity and allows for efficient bulk production of material with consistent appearance and user experience. The core of Meclib is a set of pre-defined JSXGraph-based objects with an interface to Maxima, such that no problem specific JS code is required at all. The present paper outlines the basic ideas of the implementation and demonstrates the approach for some typical examples of different complexity. The focus is on applications in engineering mechanics, starting from static illustrations up to an editor for free body diagrams, with rich adaptive formative feedback. Y1 - 2022 UR - https://online-journals.org/index.php/i-jet/article/view/36501 U6 - https://doi.org/10.3991/ijet.v17i23.36501 SN - 1863-0383 VL - 17 IS - 23 SP - 15 EP - 27 PB - International Association of Online Engineering ER - TY - JOUR A1 - Tumarkin, Andrey A1 - Tyurnina, Natalya A1 - Mukhin, Nikolay A1 - Tyurnina, Zoya A1 - Sinelshchikova, Olga A1 - Gagarin, Alexander A1 - Sapego, Eugeny A1 - Kretser, Yriy T1 - Glass-ceramic ferroelectric composite material BaTiO3/KFeSi for microwave applications JF - Composite Structures N2 - Glass-ceramic composites consisting of potassium-iron-silicate glass and barium titanate mixed in various proportions were successfully synthesized by low-temperature sintering. The crystal structure of the obtained composite samples, the porosity and the microhardness were studied by the X-ray diffraction, the electron microscopy, the weight method, and the Vickers method. Electrical characteristics (dielectric permittivity, tunability and losses) of as-prepared and annealed in oxygen medium samples were investigated at microwaves. According to structural analysis, the synthesized samples are a mixture of KFeSi glass, ferroelectric BaTiO3, and dielectric barium polytitanates; the ratio of the latter determines the electrical properties of the composites. Depending on the content of barium titanate, the studied composite samples show a permittivity from 50 to 270 with a dielectric loss level of 0,1–0,02 in frequency range from 3 to 10 GHz. Annealing of composite samples in an oxygen-containing environment leads to an increase in their dielectric permittivity and tunability by 10–25% and a twofold decrease in dielectric loss. Y1 - 2022 UR - https://linkinghub.elsevier.com/retrieve/pii/S0263822321014161 SN - 0263-8223 VL - 281 SP - 1 EP - 10 PB - Elsevier ER - TY - JOUR A1 - Kombe, Emmanuel Yeri A1 - Lang'at, Nickson A1 - Njogu, Paul A1 - Malessa, Reiner A1 - Weber, Christian-Toralf A1 - Njoka, Francis A1 - Krause, Ulrich T1 - Process modeling and evaluation of optimal operating conditions for production of hydrogen-rich syngas from air gasification of rice husks using aspen plus and response surface methodology JF - Bioresource Technology N2 - Biomass gasification is recognized as a viable avenue to accelerate the sustainable production of hydrogen. In this work, a numerical simulation model of air gasification of rice husks is developed using the Aspen Plus to investigate the feasibility of producing hydrogen-rich syngas. The model is experimentally validated with rice husk gasification results and other published studies. The influence of temperature and equivalence ratio on the syngas composition, H2 yield, LHVSyngas, H2/CO ratio, CGE, and PCG was studied. Furthermore, the synchronized effects of temperature and ER are studied using RSM to determine the operational point of maximizing H2 yield and PCG. The RSM analysis results show optimum performance at temperatures between 820 °C and 1090 °C and ER in the range of 0.06–0.10. The findings show that optimal operating conditions of the gasification system can be achieved at a more refined precision through simulations coupled with advanced optimization techniques. Y1 - 2022 UR - https://linkinghub.elsevier.com/retrieve/pii/S096085242201063X SN - 0960-8524 VL - 361 SP - 1 EP - 11 PB - Elsevier ER - TY - JOUR A1 - Ruzankina, Iuliia A1 - Mukhin, Nikolay A1 - Mermoul, Ali A1 - Parfenov, Vadim A1 - Fron, Eduard A1 - Ferrini, Gabriele T1 - Surface optical sensitivity enhanced by a single dielectric microsphere JF - Optics Express N2 - Single dielectric microspheres can manipulate light focusing and collection to enhance optical interaction with surfaces. To demonstrate this principle, we experimentally investigate the enhancement of the Raman signal collected by a single dielectric microsphere, with a radius much larger than the exciting laser spot size, residing on the sample surface. The absolute microsphere-assisted Raman signal from a single graphene layer measured in air is more than a factor of two higher than that obtained with a high numerical aperture objective. Results from Mie’s theory are used to benchmark numerical simulations and an analytical model to describe the isolated microsphere focusing properties. The analytical model and the numerical simulations justify the Raman signal enhancement measured in the microsphere-assisted Raman spectroscopy experiments. Y1 - 2022 UR - https://doi.org/10.1364/OE.472720 VL - 30 IS - 24 SP - 43021 EP - 43036 PB - Optica ER - TY - JOUR A1 - Uhl, Roland T1 - Charakterisierung des Erwartungswertes am Graphen der Verteilungsfunktion N2 - Der Erwartungswert einer Zufallsgröße kann generell am Graphen ihrer Verteilungsfunktion durch eine naheliegende Gleichheit zweier Flächeninhalte festgelegt werden. Äquivalent dazu lässt er sich mit zwei uneigentlichen Riemann-Integralen darstellen. Davon ausgehend werden die Tschebyschow-Ungleichung und ihre Modifikation mit strikten Ungleichheitszeichen hergeleitet. KW - Erwartungswert KW - Verteilungsfunktion KW - Čebyšev-Ungleichung KW - Wahrscheinlichkeitsrechnung KW - Tschebyschow-Ungleichung KW - Zufallsgröße Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus4-29862 PB - Technische Hochschule Brandenburg CY - Brandenburg an der Havel ER - TY - JOUR A1 - Wang, Jing A1 - Harth, Kirsten A1 - Puzyrev, Dmitry A1 - Stannarius, Ralf T1 - The effect of obstacles near a silo outlet on the discharge of soft spheres JF - New Journal of Physics KW - fluid dynamics Y1 - 2022 U6 - https://doi.org/10.1088/1367-2630/ac8bea VL - 24 PB - IOP ER - TY - JOUR A1 - Kuznetsov, Artur A1 - Frorip, Aleksandr A1 - Sünter, Alar A1 - Korsakov, Vadim A1 - Konoplev, Georgii A1 - Stepanova, Oksana A1 - Roschina, Natalia A1 - Ovsyannikov, Nikolay A1 - Lialin, Daniil A1 - Gerasimchuk, Roman A1 - Dmitriev, Alexander A1 - Mukhin, Nikolay A1 - Hirsch, Sören T1 - Optical Chemical Sensor Based on Fast-Protein Liquid Chromatography for Regular Peritoneal Protein Loss Assessment in End-Stage Renal Disease Patients on Continuous Ambulatory Peritoneal Dialysis JF - Chemosensors KW - optical chemical sensor KW - fast-protein liquid chromatography KW - UV LED KW - end-stage renal disease KW - peritoneal dialysis KW - peritoneal protein loss KW - albumin KW - point-of-care diagnostic devices Y1 - 2022 U6 - https://doi.org/10.3390/chemosensors10060232 VL - 10 IS - 6 PB - MDPI ER - TY - JOUR A1 - Konoplev, Georgii A1 - Agafonova, Darina A1 - Bakhchova, Liubov A1 - Mukhin, Nikolay A1 - Kurachkina, Marharyta A1 - Schmidt, Marc-Peter A1 - Verlov, Nikolay A1 - Sidorov, Alexander A1 - Oseev, Aleksandr A1 - Stepanova, Oksana A1 - Kozyrev, Andrey A1 - Dmitriev, Alexander A1 - Hirsch, Sören T1 - Label-Free Physical Techniques and Methodologies for Proteins Detection in Microfluidic Biosensor Structures JF - Biomedicines KW - label-free biosensor KW - microfluidics KW - proteins detection KW - optical biosensors KW - impedance spectroscopy KW - plasmon resonance KW - point-of-care KW - diagnostic devices Y1 - 2022 U6 - https://doi.org/10.3390/biomedicines10020207 SN - 2227-9059 VL - 10 IS - 2 SP - 207 PB - MDPI ER - TY - JOUR A1 - Vogel, Sven A1 - Wölfer, Christian A1 - Ramirez-Diaz, Diego A1 - Flassig, Robert A1 - Sundmacher, Kai A1 - Schwille, Petra T1 - Symmetry Breaking and Emergence of Directional Flows in Minimal Actomyosin Cortices JF - Cells N2 - Cortical actomyosin flows, among other mechanisms, scale up spontaneous symmetry breaking and thus play pivotal roles in cell differentiation, division, and motility. According to many model systems, myosin motor-induced local contractions of initially isotropic actomyosin cortices are nucleation points for generating cortical flows. However, the positive feedback mechanisms by which spontaneous contractions can be amplified towards large-scale directed flows remain mostly speculative. To investigate such a process on spherical surfaces, we reconstituted and confined initially isotropic minimal actomyosin cortices to the interfaces of emulsion droplets. The presence of ATP leads to myosin-induced local contractions that self-organize and amplify into directed large-scale actomyosin flows. By combining our experiments with theory, we found that the feedback mechanism leading to a coordinated directional motion of actomyosin clusters can be described as asymmetric cluster vibrations, caused by intrinsic non-isotropic ATP consumption with spatial confinement. We identified fingerprints of vibrational states as the basis of directed motions by tracking individual actomyosin clusters. These vibrations may represent a generic key driver of directed actomyosin flows under spatial confinement in vitro and in living systems. Y1 - 2020 UR - https://www.mdpi.com/2073-4409/9/6/1432 U6 - https://doi.org/10.3390/cells9061432 SP - 1 EP - 10 PB - MDPI ER - TY - JOUR A1 - Goschin, Tobias A1 - Vogel, Mathias A1 - Flassig, Robert T1 - Energy Technologies For Decarbonizing The Steel Processing Industry – A Numerical Study JF - IFAC-PapersOnLine N2 - This study analyzes approaches to decarbonize the energy supply of the secondary steel processing industry. Therefore, real data from a secondary steel production company is used in combination with state-of-the art low carbon energy supply technologies. Also, the use of waste heat from a pusher furnace for process integration is considered. The developed temporal process model allows holistic optimizing and expanding the steel making process system regarding techno-economic criteria. As we show, implementing the annual heat demand of a municipality shows that a nearly 100 % self-sufficient heat supply is possible. Y1 - 2022 UR - https://linkinghub.elsevier.com/retrieve/pii/S240589632200386X U6 - https://doi.org/https://doi.org/10.1016/j.ifacol.2022.07.001 VL - 55 IS - 9 SP - 1 EP - 5 PB - Elsevier ER - TY - JOUR A1 - Trittel, Torsten A1 - Klopp, Christoph A1 - Harth, Kirsten A1 - Stannarius, Ralf T1 - Stability and Rupture of Liquid Crystal Bridges under Microgravity JF - Crystals KW - smectic liquid-crystals KW - Rayleigh-Plateau instability KW - TEXUS suborbital rocket KW - microgravity Y1 - 2022 U6 - https://doi.org/https://doi.org/10.3390/cryst12081092 VL - 12 IS - 8 PB - MDPI ER - TY - JOUR A1 - Kolláth, Zoltán A1 - Hajdu, Tamás A1 - Degen, Tobias A1 - Jechow, Andreas A1 - Sztakovics, János T1 - Conversion between measurement units used for night sky quality assessment with multispectral (RGB) cameras JF - Journal of Quantitative Spectroscopy and Radiative Transfer N2 - In recent years, many studies have shown that light pollution adversely affects wildlife, ecosystems, and human well-being. To assess and mitigate these impacts, it is crucial that measurements of night sky quality are reliable and comparable across sites and instruments. However, the lack of standardised night sky brightness metrology and the use of a wide variety of measurement instruments with varying spectral responsivity and field-specific measurement units hinder meaningful comparison. We collected night sky spectra from 44 nights at dark locations (existing and proposed dark sky parks). Based on this observational dataset, we created a larger random set of spectra. These data served to fit conversion parameters for a wide variety of units. We demonstrate that RGB cameras, when used as multichannel measuring devices, enable the retrieval of measurements that facilitate conversions between different units. Furthermore, even airglow can be quantified from a given measurement, enabling the determination of oxygen and sodium emission line contributions. Since this contribution is not negligible, quantitative measurements of its magnitude are crucial for accurately assessing light pollution at dark-sky sites. Using our spectral measurement database, we constructed the most probable transformation from the cameras’ R, G, and B channel 𝑑𝑠𝑢 values to other units, such as the astronomical Bessel V band magnitudes. The unit conversion formulas provided in this paper are valid for mildly polluted sites (existing and proposed dark sky places), in the 21-22 magV∕arcsec2 range. Y1 - 2025 U6 - https://doi.org/10.1016/j.jqsrt.2025.109636 VL - 347 SP - 1 EP - 10 PB - Elsevier ER - TY - JOUR A1 - Schumann, Sophia A1 - Stoilova, Velizara A1 - Bortoletto, Enrico A1 - Piva, Elisabetta A1 - Pacchini, Sara A1 - Mozzi, Gloria A1 - Jechow, Andreas A1 - Marion, Andrea A1 - Bertotto, Daniela A1 - Erlandson, Ann A1 - Hölker, Franz A1 - Greenberg, Larry A1 - Santovito, Gianfranco T1 - Impact of artificial light at night (ALAN) on cardiac function and acute oxidative stress physiology in migratory brown trout smolts JF - Environmental Pollution N2 - Light pollution poses significant ecological challenges for nocturnal animals reliant on natural light for migration, orientation, and circadian rhythms. The physiological effects of abrupt exposure to artificial light at night (ALAN) on migratory fish, such as the light experienced passing near illuminated infrastructures, remain poorly understood. This study investigates the physiological responses of brown trout (Salmo trutta) smolts to low-intensity (0.02 lx) and short-term (30 s) ALAN, simulating nocturnal migration light conditions near illuminated bridges. To evaluate the influence of social dynamics, trout were tested individually (solitary) or in groups of six. Using continuous cardiac monitoring with data storage tags, alongside analyses of oxidative stress markers and adenylate kinase (AK) activity in the heart, we identified distinct patterns of physiological responses. Solitary fish exhibited significant heart rate variability (HRV) increases following repeated ALAN exposure, suggesting impaired physiological regulation under repeated ALAN exposure. In contrast, trout in groups displayed consistently lower HRV over the entire 90-min experiment, implying that social dynamics likely influenced a sustained oxidative stress response, corroborated by increased AK activity. Oxidative stress markers further reflected social effects, with significant upregulation of key antioxidant enzymes (sod1, sod2, gpx1, gpx4) and elevated lipid peroxidation, identifying lipids as primary oxidative targets. The observed divergence between superoxide dismutase (SOD) activity and sod gene expression suggests adaptive post-transcriptional regulation to maintain redox balance under combined environmental and social stress. These findings reveal that social dynamics under ALAN can amplify physiological stress, potentially affecting migratory outcomes. Y1 - 2025 U6 - https://doi.org/10.1016/j.envpol.2025.126593 IS - 381 SP - 1 EP - 9 PB - Elsevier ER - TY - JOUR A1 - Kalinkat, Gregor A1 - Jechow, Andreas A1 - Schroer, Sibylle A1 - Hölker, Franz T1 - Nocturnal pandas: conservation umbrellas protecting nocturnal biodiversity JF - Trends in Ecology & Evolution N2 - 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. Y1 - 2025 U6 - https://doi.org/10.1016/j.tree.2025.05.006 VL - 40 IS - 8 SP - 736 EP - 739 PB - Elsevier ER - TY - JOUR A1 - Vollmer, Michael A1 - Eberhardt, Wolfgang T1 - Ein einfaches Modell für die Vorhersage von CO2 Konzentrationen in der Atmosphäre in Abhängigkeit von globalen CO2 Emissionen JF - PhyDid B, Didaktik der Physik, Beiträge zur DPG-Frühjahrstagung N2 - Es wird das vielleicht einfachst mögliche Modell vorgestellt, mit dem zeitabhängige CO2 Konzent-rationen c(t) in der Atmosphäre ausgehend von verschiedenen globalen Emissionsszenarien für CO2berechnet werden. Dazu wird eine einzelne inhomogene lineare Differenzialgleichung 1. Ordnung hergeleitet, deren Parameter sich aus den quantitativen Daten des global carbon project sowie Mauna Loa Daten für CO2 Konzentrationen errechnen. Das Modell wird erstens getestet am Zeitraum 1960 bis 2020 mit vergleichsweise guter quantitativer Übereinstimmung zu Messdaten. Zweitens wird für zwei typische IPCC Emissions-Szenarien ein Vergleich der Modellvorhersagen mit denen der kom-plexen IPCC Earth-System-Klimamodelle diskutiert mit qualitativer Übereinstimmung des zeitli-chen Verlaufs. Drittens werden Ergebnisse einiger ausgewählter neuer Emissionsszenarien präsen-tiert. Ungeachtet einiger Abweichungen zu komplexeren Klimamodellen zeichnet sich unser Mo-dell durch zwei wichtige Vorteile für die Lehre aus. Zum einen ist es sehr einfach für Studierende und begabte Schüler nutzbar, da die erforderliche Lösung der Differentialgleichung bereits mit han-delsüblicher Tabellenkalkulationssoftware wie z.B. Excel programmiert werden kann. Dadurch ge-stattet es zum anderen auch sehr einfach, den zeitlichen Verlauf von Emissionsszenarien zu verän-dern und innerhalb weniger Sekunden Veränderungen aufgrund geänderter Eingaben zu berechnen. Insofern eignet sich das Modell sehr gut als Einstieg in das Thema Klimamodellierung in einführen-den Hochschulvorlesungen zum Themenbereich Kohlenstoffkreislauf und Klimawandel. In der Schule kann es gegen Ende der Sekundarstufe 2 beispielsweise im Projektunterricht zum Themen-komplex Nachhaltigkeit in Physik und/oder Mathematik eingesetzt werden Y1 - 2024 UR - https://ojs.dpg-physik.de/index.php/phydid-b/article/view/1411 SN - 2191-379X VL - 1 IS - 1 SP - 379 EP - 388 PB - FU Berlin ER - TY - JOUR A1 - Klopp, Christoph A1 - Trittel, Torsten A1 - Stannarius, Ralf T1 - Coarsening of quasi two-dimensional emulsions formed by islands in free-standing smectic films JF - ChemPhysChem N2 - We study the coarsening behavior of assemblies of islands on smectic A freely suspended films in ISS microgravity experiments. The islands can be regarded as liquid inclusions in a two-dimensional fluid in analogy to liquid droplets of the discontinuous phase of an emulsion. The coarsening is effectuated by two processes, predominantly by island coalescence, but to some extend also by Ostwald ripening, whereby large islands grow at the expense of surrounding smaller ones. A peculiarity of this system is that the continuous and the discontinuous phases consist of the same material. We determine the dynamics, analyze the self-similar aging of the island size distribution and discuss characteristic exponents of the mean island growth. Y1 - 2024 U6 - https://doi.org/10.1002/cphc.202400166 VL - 25 IS - 12 SP - 1 EP - 12 PB - Wiley ER - TY - JOUR A1 - Vollmer, Michael T1 - Limitations of the eye and how to overcome them JF - Journal of Physics: Conference Series N2 - Human eyes have spatial, temporal, and spectral limitations which impose constraints on our perception. With appropriate optical devices and cameras, the limitations can be easily overcome. As a consequence, a huge variety of physical phenomena can be made accessible for teaching. Y1 - 2024 U6 - https://doi.org/10.1088/1742-6596/2750/1/012001 VL - 2750 IS - 1 SP - 1 EP - 10 ER - TY - JOUR A1 - Puzyrev, Dmitry A1 - Torsten, Torsten A1 - Harth, Kirsten A1 - Stannarius, Ralf T1 - Cooling of a granular gas mixture in microgravity JF - npj microgravity N2 - Granular gases are fascinating non-equilibrium systems with interesting features such as spontaneous clustering and non-Gaussian velocity distributions. Mixtures of different components represent a much more natural composition than monodisperse ensembles but attracted comparably little attention so far. We present the observation and characterization of a mixture of rod-like particles with different sizes and masses in a drop tower experiment. Kinetic energy decay rates during granular cooling and collision rates were determined and Haff’s law for homogeneous granular cooling was confirmed. Thereby, energy equipartition between the mixture components and between individual degrees of freedom is violated. Heavier particles keep a slightly higher average kinetic energy than lighter ones. Experimental results are supported by numerical simulations. Y1 - 2024 U6 - https://doi.org/10.1038/s41526-024-00369-5 VL - 10 IS - 1 SP - 1 EP - 9 PB - Springer CY - Brandenburg an der Havel ER - TY - JOUR A1 - Trittel, Torsten A1 - Puzyrev, Dmitry A1 - Harth, Kirsten A1 - Stannarius, Ralf T1 - Rotational and translational motions in a homogeneously cooling granular gas JF - npj microgravity N2 - A granular gas composed of monodisperse spherical particles was studied in microgravity experiments in a drop tower. Translations and rotations of the particles were extracted from optical video data. Equipartition is violated, the rotational degrees of freedom were excited only to roughly 2/3 of the translational ones. After stopping the mechanical excitation, we observed granular cooling of the ensemble for a period of three times the Haff time, where the kinetic energy dropped to about 5% of its initial value. The cooling rates of all observable degrees of freedom were comparable, and the ratio of rotational and translational kinetic energies fluctuated around a constant value. The distributions of translational and rotational velocity components showed slight but systematic deviations from Gaussians at the start of cooling. Y1 - 2024 U6 - https://doi.org/10.1038/s41526-024-00420-5 VL - 10 IS - 1 SP - 1 EP - 6 PB - Springer ER - TY - JOUR A1 - Jechow, Andreas A1 - Bumberger, Jan A1 - Palm, Bert A1 - Remmler, Paul A1 - Schreck, Günter A1 - Ogashawara, Igor A1 - Kiel, Christine A1 - Kohnert, Katrin A1 - Grossart, Hans-Peter A1 - Singer, Gabirel A. A1 - Nejstgaard, Jens C. A1 - Wollrab, Sabine A1 - Berger, Stella A. A1 - Hölker, Franz T1 - Characterizing and Implementing the Hamamatsu C12880MA Mini-Spectrometer for Near-Surface Reflectance Measurements of Inland Waters JF - Sensors N2 - In recent decades, inland water remote sensing has seen growing interest and very strong development. This includes improved spatial resolution, increased revisiting times, advanced multispectral sensors and recently even hyperspectral sensors. However, inland waters are more challenging than oceanic waters due to their higher complexity of optically active constituents and stronger adjacency effects due to their small size and nearby vegetation and built structures. Thus, bio-optical modeling of inland waters requires higher ground-truthing efforts. Large-scale ground-based sensor networks that are robust, self-sufficient, non-maintenance-intensive and low-cost could assist this otherwise labor-intensive task. Furthermore, most existing sensor systems are rather expensive, precluding their employability. Recently, low-cost mini-spectrometers have become widely available, which could potentially solve this issue. In this study, we analyze the characteristics of such a mini-spectrometer, the Hamamatsu C12880MA, and test it regarding its application in measuring water-leaving radiance near the surface. Overall, the measurements performed in the laboratory and in the field show that the system is very suitable for the targeted application. Y1 - 2024 U6 - https://doi.org/10.3390/s24196445 VL - 24 IS - 19 SP - 1 EP - 14 PB - MDPI ER - TY - JOUR A1 - Daupayev, Nursultan A1 - Engel, Christian A1 - Hirsch, Sören T1 - Two-to-One Trigger Mechanism for Event-Based Environmental Sensing JF - Sensors N2 - Environmental monitoring systems often operate continuously, measuring various parameters, including carbon dioxide levels (CO2), relative humidity (RH), temperature (T), and other factors that affect environmental conditions. Such systems are often referred to as smart systems because they can autonomously monitor and respond to environmental conditions and can be integrated both indoors and outdoors to detect, for example, structural anomalies. However, these systems typically have high energy consumption, data overload, and large equipment sizes, which makes them difficult to install in constrained spaces. Therefore, three challenges remain unresolved: efficient energy use, accurate data measurement, and compact installation. To address these limitations, this study proposes a two-to-one threshold sampling approach, where the CO2 measurement is activated when the specified T and RH change thresholds are exceeded. This event-driven method avoids redundant data collection, minimizes power consumption, and is suitable for resource-constrained embedded systems. The proposed approach was implemented on a low-power, small-form and self-made multivariate sensor based on the PIC16LF19156 microcontroller. In contrast, a commercial monitoring system and sensor modules based on the Arduino Uno were used for comparison. As a result, by activating only key points in the T and RH signals, the number of CO2 measurements was significantly reduced without loss of essential signal characteristics. Signal reconstruction from the reduced points demonstrated high accuracy, with a mean absolute error (MAE) of 0.0089 and root mean squared error (RMSE) of 0.0117. Despite reducing the number of CO2 measurements by approximately 41.9%, the essential characteristics of the signal were saved, highlighting the efficiency of the proposed approach. Despite its effectiveness in controlled conditions (in buildings, indoors), environmental factors such as the presence of people, ventilation systems, and room layout can significantly alter the dynamics of CO2 concentrations, which may limit the implementation of this approach. Future studies will focus on the study of adaptive threshold mechanisms and context-dependent models that can adjust to changing conditions. This approach will expand the scope of application of the proposed two-to-one sampling technique in various practical situations. Y1 - 2025 UR - https://www.mdpi.com/1424-8220/25/13/4107 U6 - https://doi.org/10.3390/s25134107 VL - 25 IS - 13 SP - 1 EP - 18 PB - MDPI ER - TY - JOUR A1 - Vollmer, Michael T1 - Nachtsicht ins All mit dem bloßen Auge: Sag mir, wie weit die Sterne steh'n JF - Physik in unserer Zeit Y1 - 2025 U6 - https://doi.org/10.1002/piuz.202501751 VL - 2025 SP - 2 EP - 10 PB - Wiley ER - TY - JOUR A1 - Mushunuri, Ashwini A1 - Adesoji, Oluyomi A1 - Krause, Roland A1 - May, Patrick A1 - Lerche, Holger A1 - Becker, Albert A1 - Grimm, Daniela A1 - Nothnagel, Michael A1 - Schulz, Herbert T1 - Genetic risk factor identification for common epilepsies guided by integrative omics data analysis JF - Epilepsia N2 - Objective Genetic generalized epilepsies (GGEs) comprise the most common genetically determined epilepsy syndromes, following a complex mode of inheritance. Although many important common and rare genetic factors causing or contributing to these epilepsies have been identified in the past decades, many features of the genetic architecture are still insufficiently understood. This study integrates genome-wide association study (GWAS) data from the International League Against Epilepsy Consortium on Complex Epilepsies with transcriptome-wide association studies to identify genes whose genetically regulated expression levels are associated with epilepsy. Methods To achieve this, we used multiple computational approaches, including MAGMA, a tool for gene analysis of GWAS data, and its derivatives E-MAGMA and H-MAGMA, to improve gene mapping accuracy by utilizing tissue-specific expression and chromatin interaction data. Furthermore, we developed ME-MAGMA to incorporate methylation quantitative trait loci data, providing insights into epigenetic factors. Results We identified a total of 897 false discovery rate-corrected (<.05) candidates. These include voltage-gated calcium channels, voltage-gated potassium channels, and other genes such as NPRL2, CACNB2, and KCNT1 associated with epilepsy pathogenesis that act as key players in neuronal communication and signaling in the brain. Significance In this study, we propose new candidate genes to expand the dataset of potential epilepsy-causing genes. Further research on these genes may enhance our understanding of the complex regulatory mechanisms underlying GGE and other types of epilepsy, potentially revealing targets for therapeutic intervention. Y1 - 2025 U6 - https://doi.org/10.1111/epi.70021 PB - Wiley ER - TY - JOUR A1 - Sata, Sai Preetham A1 - Stannarius, Ralf A1 - Puzyrev, Dmitry T1 - Criteria for dynamical clustering in permanently excited granular gases: comparison and estimation with machine learning approaches JF - Granular Matter N2 - When granular gases in microgravity are continuously excited mechanically, spatial inhomogeneities of the particle distribution can emerge. At a sufficiently large overall packing fraction, a significant share of particles tend to concentrate in strongly overpopulated regions, so-called clusters, far from the excitation sources. This dynamical clustering is caused by a complex balance between energy influx and dissipation. The mean number density of particles, the geometry of the container, and the excitation strength influence cluster formation. A quantification of clustering thresholds is not trivial. We generate ‘synthetic’ data sets by Discrete Element Method simulations of frictional spheres in a cuboid container and apply established criteria to classify the local packing fraction profiles. Machine learning approaches that predict dynamic clustering from known system parameters on the basis of classical test criteria areoposed and tested. It avoids the necessity of complex numerical simulations. Y1 - 2025 U6 - https://doi.org/10.1007/s10035-025-01560-5 VL - 27 IS - 4 PB - Springer ER - TY - JOUR A1 - Harth, Kirsten A1 - Trittel, Torsten A1 - Mohammadi, Mahdieh A1 - Puzyrev, Dmitry A1 - Enezz, Mohammad A1 - Cruz Hidalgo, Raul A1 - Stannarius, Ralf ED - Alam, M. ED - Das, S.L. ED - Bose, M. ED - Murthy, T.G. ED - Chikkadi, V. ED - Singh, A. ED - Luding, S. T1 - Granular gases of rough spheres: Velocity, rotation and collision statistics from in-situ measurements, optical data and simulations JF - EPJ Web of Conferences N2 - Granular gases are not only of interest in fundamental physics, but they can also serve as a test ensembles for the validity of collision models employed in (loose) granular matter. The theoretical literature mainly addresses spheres under ideal conditions and simulations allow full access to all particle parameters, but experiments cannot fulfill these idealizations. We investigate granular gases of soft, rough spheres by combining microgravity experiments and adjusted simulations. We introduce Smart Particles with embedded autarkic micro-sensors for in-situ measurements of rotation rates and accelerations. Additionally, we extract 3D positions, translations and orientations of the particles from stereoscopic video data using Machine-Learning based algorithms. We address the partition of kinetic energy between the degrees of freedom, the angular and translational velocity as well as collision statistics. A simulation is adjusted to experiment parameters, showing good agreement of translational motion, but qualitative differences in the decay of rotational kinetic energy. Y1 - 2025 U6 - https://doi.org/10.1051/epjconf/202534003012 VL - 340 PB - EDP Sciences ER - TY - JOUR A1 - Stannarius, Ralf A1 - Wang, Jing A1 - Pongó, Tivadar A1 - Fan, Bo A1 - Börzsönyi, Tamás A1 - Hidalgo, Raúl Cruz ED - Alam, M. ED - Das, S.L. ED - Bose, M. ED - Murthy, T.G. ED - Chikkadi, V. ED - Singh, A. ED - Luding, S. T1 - Forces on a sphere suspended in flowing granulate JF - EPJ Web of Conferences N2 - We investigate the forces of flowing granular material on an obstacle. A sphere suspended in a discharging silo experiences both weight of the overlaying layers and drag of the surrounding moving grains. In experiments with frictional hard glass beads, the force on the obstacle was found to be practically flow-rate independent. In contrast, flow of nearly frictionless soft hydrogel spheres added drag forces which increased with the flow rate until reaching saturation at high flow speeds. The total force grew quadratically with the obstacle diameter in the soft, low friction material, while it grew much weaker, nearly linearly with the obstacle diameter, in the bed of hard, frictional glass spheres. In addition to the drag, obstacles embedded in the flowing hydrogel spheres experience a weight force from the top as if immersed in a hydrostatic pressure profile, but negligible counter-forces from below. In contrast, the frictional hard particles create a strong pressure gradient near the upper surface of the obstacle. Numerical simulations provide additional information that is difficult to access experimentally. They reproduce the experimental results and give hints for the origin of the different force contributions. The results have considerable practical importance for the discharge of storage containers with large objects suspended in flowing granular material. Y1 - 2025 U6 - https://doi.org/10.1051/epjconf/202534002019 VL - 340 PB - EDP Sciences ER - TY - JOUR A1 - Preetham Sata, Sai A1 - Stannarius, Ralf A1 - Puzyrev, Dmitry ED - Alam, M. ED - Das, S.L. ED - Bose, M. ED - Murthy, T.G. ED - Chikkadi, V. ED - Singh, A. ED - Luding, S. T1 - Machine learning for prediction of dynamical clustering in granular gases JF - EPJ Web of Conferences N2 - Continuously excited dense granular gases in microgravity can develop spatial inhomogeneities of the particle distribution. Dynamical clustering is a phenomenon where a significant share of particles concentrate in strongly overpopulated regions. It is caused by a complex interplay between the energy influx and dissipation in collisions. The overall packing fraction, container geometry, and excitation parameters influence the gas-cluster transition. We perform Discrete Element Method (DEM) simulations for frictional spheres in a cuboid container and apply statistical criteria to the packing fraction profiles. Machine learning (ML) methods are used to study the dependence of the gas-cluster transition on system parameters. It is a promising alternative to predict the state of the system without the need for the time-consuming DEM simulations. We identify the best models for predicting the dynamical clustering of frictional spheres in a specific experimental geometry. Y1 - 2025 U6 - https://doi.org/10.1051/epjconf/202534012012 VL - 340 PB - EDP Sciences ER - TY - JOUR A1 - Vollmer, Michael T1 - Naked eye celestial objects and phenomena: how far can we see at night? JF - European Journal of Physics N2 - 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. Y1 - 2025 U6 - https://doi.org/10.1088/1361-6404/adbf74 VL - 46 IS - 3 PB - IOP Science ER - TY - JOUR A1 - Vollmer, Michael T1 - How far can we see at day? JF - European Journal of Physics N2 - We discuss the farthest objects on Earth observable for the unaided, healthy naked eye during the daytime, i.e., the maximum visual range for observers on Earth. Visual range depends first on the properties of the material between observer and object and its interaction processes with radiation, but second also on our visual perception system. After a rough comparison of ranges in water, glass, and the atmosphere, we focus on the physical basis of visual range for the latter. As a contrast phenomenon, visual range refers to allowed light paths within the atmosphere. It results from the interplay of geometry, refraction, and light scattering. We present a concise overview of this field by qualitative descriptions and quantitative estimates as well as classroom demonstration experiments. The starting point is the common geometrical visual ranges, followed by extensions due to refraction and limitations due to contrast, which depend on scattering and absorption processes within the atmosphere. The quantitative discussion of scattering is very helpful to easily understand the huge ranges in nature from meters in dense fog to hundreds of kilometers in clear atmospheres. Extreme visual ranges from about 300 km to above 500 km require optimal atmospheric conditions, cleverly chosen locations and times, and a sophisticated topography analysis. Even longer visual ranges are possible when looking through the vertical atmosphere. From the ISS, daytime ranges well above 1000 km are possible. Y1 - 2025 U6 - https://doi.org/10.1088/1361-6404/adc4a0 VL - 46 IS - 3 PB - IOP Science ER -