51. A dual-wavelength photothermal aerosol absorption monitor : design, calibration and performanceLuka Drinovec, Uroš Jagodič, Luka Pirker, Miha Škarabot, Mario Kurtjak, Kristijan Vidović, Luca Ferrero, Bradley Visser, Jannis Röhrbein, Ernest Weingartner, Daniel M. Kalbermatter, Konstantina Vasilatou, Griša Močnik, 2022, original scientific article Abstract: There exists a lack of aerosol absorption measurement techniques with low uncertainties and without artefacts. We have developed the two-wavelength Photothermal Aerosol Absorption Monitor (PTAAM-2λ), which measures the aerosol absorption coefficient at 532 and 1064 nm. Here we describe its design, calibration and mode of operation and evaluate its applicability, limits and uncertainties. The 532 nm channel was calibrated with ∼ 1 µmol mol−1 NO2, whereas the 1064 nm channel was calibrated using measured size distribution spectra of nigrosin particles and a Mie calculation. Since the aerosolized nigrosin used for calibration was dry, we determined the imaginary part of the refractive index of nigrosin from the absorbance measurements on solid thin film samples. The obtained refractive index differed considerably from the one determined using aqueous nigrosin solution. PTAAM-2λ has no scattering artefact and features very low uncertainties: 4 % and 6 % for the absorption coefficient at 532 and 1064 nm, respectively, and 9 % for the absorption Ångström exponent. The artefact-free nature of the measurement method allowed us to investigate the artefacts of filter photometers. Both the Aethalometer AE33 and CLAP suffer from cross-sensitivity to scattering – this scattering artefact is most pronounced for particles smaller than 70 nm. We observed a strong dependence of the filter multiple scattering parameter on the particle size in the 100–500 nm range. The results from the winter ambient campaign in Ljubljana showed similar multiple scattering parameter values for ambient aerosols and laboratory experiments. The spectral dependence of this parameter resulted in AE33 reporting the absorption Ångström exponent for different soot samples with values biased 0.23–0.35 higher than the PTAAM-2λ measurement. Photothermal interferometry is a promising method for reference aerosol absorption measurements.
Keywords: aerosol absorption, calibration, black carbon
Published in RUNG: 28.06.2022; Views: 1209; Downloads: 25
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52. The impact of temperature inversions on black carbon and particle mass concentrations in a mountainous areaKristina Glojek, Griša Močnik, Honey Dawn C. Alas, Andrea Cuesta-Mosquera, Luka Drinovec, Asta Gregorič, Matej Ogrin, Kay Weinhold, Irena Ježek, Martin Rigler, Maja Remškar, Miha Markelj, 2022, original scientific article Abstract: Residential wood combustion is a widespread practice in Europe with a serious impact on air quality, especially in mountainous areas. While there is a significant number of studies conducted in deep urbanized valleys and basins, little is known about the air pollution processes in rural shallow hollows, where around 30 % of the people in mountainous areas across Europe live. We aim to determine the influence of ground temperature inversions on wood combustion aerosol pollution in hilly, rural areas. The study uses Retje karst hollow (Loški Potok, Slovenia) as a representative site for mountainous and hilly rural areas in central and south-eastern Europe with residential wood combustion. Sampling with a mobile monitoring platform along the hollow was performed in December 2017 and January 2018. The backpack mobile monitoring platform was used for the determination of equivalent black carbon (eBC) and particulate matter (PM) mass concentrations along the hollow. To ensure high quality of mobile measurement data, intercomparisons of mobile instruments with reference instruments were performed at two air quality stations during every run. Our study showed that aerosol pollution events in the relief depression were associated with high local emission intensities originating almost entirely from residential wood burning and shallow temperature inversions (58 m on average). The eBC and PM mass concentrations showed stronger associations with the potential temperature gradient (R2=0.8) than with any other meteorological parameters taken into account (ambient temperature, relative humidity, wind speed, wind direction, and precipitation). The strong association between the potential temperature gradient and pollutant concentrations suggests that even a small number of emission sources (total 243 households in the studied hollow) in similar hilly and mountainous rural areas with frequent temperature inversions can significantly increase the levels of eBC and PM and deteriorate local air quality. During temperature inversions the measured mean eBC and PM2.5 mass concentrations in the whole hollow were as high as 4.5±2.6 and 48.0 ± 27.7 µg m−3, respectively, which is comparable to larger European urban centres.
Keywords: air pollution, black carbon, sources, temperature inversion, mountainous area
Published in RUNG: 03.05.2022; Views: 1385; Downloads: 0
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55. Experimental dataset - A dual-wavelength photothermal aerosol absorption monitor: design, calibration and performanceLuka Drinovec, Uroš Jagodič, Luka Pirker, Miha Škarabot, Mario Kurtjak, Kristijan Vidović, Luca Ferrero, Bradley Visser, Jannis Röhrbein, Ernest Weingartner, Daniel Kalbermatter, Konstantina Vasilatou, Tobias Bühlmann, Celine Pascale, Thomas Müller, Alfred Wiedensohler, Griša Močnik, complete scientific database of research data Keywords: photothermal interferometer, aerosol light absorption coefficient
Published in RUNG: 14.01.2022; Views: 1808; Downloads: 28
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56. Bioaerosol partitioning between the interstitial and condensed phase in mixed-phase clouds : lecture NOSA Symposium 2021, March 16th 2021, onlineTina Šantl Temkiv, Miha Živec, Mojca Benčina, Samo Stanič, Griša Močnik, 2021, unpublished conference contribution Keywords: bioaerosol, aerosol, mixed-phase clouds, LIDAR
Published in RUNG: 22.11.2021; Views: 1811; Downloads: 45
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57. Elementi monodrame in avtobiografskosti v besedilih Simone Semenič : vidik računalniške stilometrijeIvana Zajc, 2019, original scientific article Abstract: V članku obravnavamo osrednji opus dramatičarke Simone Semenič z metodo računalniške stilometrije. Ugotavljamo, da je heterogen, razvrsti se v tri skupine besedil. Najizraziteje se dela razdelijo glede na to, ali so monološka, ali vsebujejo tradicionalno obliko dialogov, ali pa gre za kombinacijo dialogov z monologi, ki so najočitnejši v daljših didaskalijah. Iz opusa avtorice slogovno izstopa skupina monodramskih besedil Jaz, žrtev , še me dej in drugič , pa tudi delo gostija , ki ga stilometrična analiza uvrsti k tem besedilom. Ukvarjamo se z monodramskimi oziroma avtobiografskimi elementi, po katerih ta besedila izstopajo iz dosedanjega dramskega opusa Simone Semenič. Raziskava besedišča dram potrjuje dosedanje teoretične ugotovitve, da imajo dela še me dej , drugič in gostija v opusu avtorice največ elementov metadrame, ki izhajajo iz pripovedi osrednjega lika. To ne drži za delo Jaz, žrtev , ki v obravnavanem opusu izstopa zaradi nanašanja subjektke na samo sebe.
Keywords: slovenske drame, monodrame, stilometrija, avtobiografskost, literarne študije
Published in RUNG: 05.11.2021; Views: 1440; Downloads: 0
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59. Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagationH. Abdalla, H. Abe, Fabio Acero, A. Acharyya, R. Adam, Christopher Eckner, Samo Stanič, Serguei Vorobiov, Gabrijela Zaharijas, Marko Zavrtanik, Danilo Zavrtanik, Miha Živec, 2021, original scientific article Abstract: The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for γ astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of γ cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of γ absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift z=2 and to constrain or detect γ halos up to intergalactic-magnetic-field strengths of at least 0.3 pG . Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from γ astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of γ cosmology.
Keywords: Cherenkov Telescope Array, active galactic nuclei, gamma-ray experiments, axions, extragalactic magnetic fields
Published in RUNG: 02.03.2021; Views: 2328; Downloads: 71
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60. Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centreA. Acharyya, R. Adam, C. Adams, I. Agudo, A. Aguirre-Santaella, Christopher Eckner, Samo Stanič, Serguei Vorobiov, Gabrijela Zaharijas, Marko Zavrtanik, Danilo Zavrtanik, Miha Živec, 2021, original scientific article Keywords: dark matter, gamma ray, astrophysics
Published in RUNG: 26.02.2021; Views: 2436; Downloads: 141
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