Fakultät Naturwissenschaften

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Biologie, Ernährungs-wissenschaften und Lebensmittelwissenschaften sind die Schwerpunkte der Fakultät. Die Forschung befasst sich mit Schlüsselthemen der Life Sciences.

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Browsing Fakultät Naturwissenschaften by Sustainable Development Goals "11"

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    Publication
    Analysis of secondary inorganic aerosols over the greater Athens area using the EPISODE–CityChem source dispersion and photochemistry model
    (2024) Myriokefalitakis, Stelios; Karl, Matthias; Weiss, Kim A.; Karagiannis, Dimitris; Athanasopoulou, Eleni; Kakouri, Anastasia; Bougiatioti, Aikaterini; Liakakou, Eleni; Stavroulas, Iasonas; Papangelis, Georgios; Grivas, Georgios; Paraskevopoulou, Despina; Speyer, Orestis; Mihalopoulos, Nikolaos; Gerasopoulos, Evangelos; Myriokefalitakis, Stelios; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Karl, Matthias; Helmholtz-Zentrum Hereon, Geesthacht, Germany; Weiss, Kim A.; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Karagiannis, Dimitris; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Athanasopoulou, Eleni; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Kakouri, Anastasia; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Bougiatioti, Aikaterini; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Liakakou, Eleni; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Stavroulas, Iasonas; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Papangelis, Georgios; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Grivas, Georgios; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Paraskevopoulou, Despina; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Speyer, Orestis; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Mihalopoulos, Nikolaos; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece; Gerasopoulos, Evangelos; Institute for Environmental Research and Sustainable Development (IERSD), National Observatory of Athens, Penteli, Greece
    Secondary inorganic aerosols (SIAs) are major components of fine particulate matter (PM 2.5), having substantial implications for climate and air quality in an urban environment. In this study, a state-of-the-art thermodynamic model has been coupled to the source dispersion and photochemistry city-scale chemistry transport model EPISODE–CityChem, which is able to simulate pollutants at a horizontal resolution of 100m×100m, to determine the equilibrium between the inorganic gas and aerosol phases over the greater Athens area, Greece, for the year 2019. In agreement with in situ observations, sulfate ( SO42-) is calculated to have the highest annual mean surface concentration (2.15  ± 0.88  µgm-3) among SIAs in the model domain, followed by ammonium ( NH4+; 0.58  ± 0.14  µgm-3) and fine nitrate ( NO3-; 0.24  ± 0.22  µgm-3). Simulations denote that NO3-formation strongly depends on the local nitrogen oxide emissions, along with the ambient temperature, the relative humidity, and the photochemical activity. Additionally, we show that anthropogenic combustion sources may have an important impact on the NO3-formation in an urban area. During the cold period, the combined effect of decreased temperature in the presence of non-sea-salt potassium favors the partitioning of HNO3in the aerosol phase in the model, raising the NO3-formation in the area. Overall, this work highlights the significance of atmospheric composition and the local meteorological conditions for the equilibrium distribution of nitrogen-containing semi-volatile compounds and the acidity of inorganic aerosols, especially in urban areas where atmospheric trace elements from natural and anthropogenic sources coexist.
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    Publication
    On the temperature stability requirements of free-running Nd:YAG lasers for atmospheric temperature profiling through the rotational Raman technique
    (2024) Zenteno-Hernández, José Alex; Comerón, Adolfo; Dios, Federico; Rodríguez-Gómez, Alejandro; Muñoz-Porcar, Constantino; Sicard, Michaël; Franco, Noemi; Behrendt, Andreas; Di Girolamo, Paolo; Zenteno-Hernández, José Alex; Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), 72840 Puebla, Mexico; Comerón, Adolfo; CommSensLab, Dept. of Signal Theory and Communications, Universitat Politècnica de Catalunya (UPC), 08034 Barcelona, Spain; Dios, Federico; CommSensLab, Dept. of Signal Theory and Communications, Universitat Politècnica de Catalunya (UPC), 08034 Barcelona, Spain; Rodríguez-Gómez, Alejandro; CommSensLab, Dept. of Signal Theory and Communications, Universitat Politècnica de Catalunya (UPC), 08034 Barcelona, Spain; Muñoz-Porcar, Constantino; CommSensLab, Dept. of Signal Theory and Communications, Universitat Politècnica de Catalunya (UPC), 08034 Barcelona, Spain; Sicard, Michaël; CommSensLab, Dept. of Signal Theory and Communications, Universitat Politècnica de Catalunya (UPC), 08034 Barcelona, Spain; Franco, Noemi; Scuola di Ingegneria, Università della Basilicata, 85100 Potenza, Italy; Behrendt, Andreas; University of Hohenheim, Institute of Physics and Meteorology, 70599 Stuttgart, Germany; Di Girolamo, Paolo; Scuola di Ingegneria, Università della Basilicata, 85100 Potenza, Italy
    We assess the temperature stability requirements of unseeded Nd:YAG lasers in lidar systems for atmospheric temperature profiling through the rotational Raman technique. Taking as a reference a system using a seeded laser assumed to emit pulses of negligible spectral width and free of wavelength drifts, we estimate first the effect of the pulse spectral widening of the unseeded laser on the output of the interference filters, and then we derive the limits of the allowable wavelength drift for a given bias in the temperature measurement that would add to the noise-induced uncertainty. Finally, using spectroscopic data, we relate the allowable wavelength drift to allowable temperature variations in the YAG rod. We find that, in order to keep the bias affecting atmospheric temperature measurements smaller than 1 K, the Nd:YAG rod temperature should also be kept within a variation range of 1 K.