Repozitorij Univerze v Novi Gorici

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


21 - 27 / 27
Na začetekNa prejšnjo stran123Na naslednjo stranNa konec
21.
A single-beam photothermal interferometer for in situ measurements of aerosol light absorption
Bradley Visser, Jannis Röhrbein, Peter Steigmeier, Luka Drinovec, Griša Močnik, Ernest Weingartner, 2020, izvirni znanstveni članek

Opis: We have developed a novel single-beam photothermal interferometer and present here its application for the measurement of aerosol light absorption. The use of only a single laser beam allows for a compact optical set-up and significantly easier alignment compared to standard dual-beam photothermal interferometers, making it ideal for field measurements. Due to a unique configuration of the reference interferometer arm, light absorption by aerosols can be determined directly – even in the presence of light-absorbing gases. The instrument can be calibrated directly with light-absorbing gases, such as NO2, and can be used to calibrate other light absorption instruments. The detection limits (1σ) for absorption for 10 and 60 s averaging times were determined to be 14.6 and 7.4 Mm−1, respectively, which for a mass absorption cross section of 10 m2 g−1 leads to equivalent black carbon concentration detection limits of 1460 and 740 ng m−3, respectively. The detection limit could be reduced further by improvements to the isolation of the instrument and the signal detection and processing schemes employed.
Najdeno v: osebi
Ključne besede: aerosol, aerosol absorption, black carbon, photo-thermal interferometer, climate change
Objavljeno: 29.12.2020; Ogledov: 1378; Prenosov: 38
.pdf Polno besedilo (2,44 MB)

22.
Hidden black carbon air pollution in hilly rural areas - a case study of Dinaric depression
Kristina Glojek, Asta Gregorič, Griša Močnik, Andrea Cuesta-Mosquera, A. Wiedensohler, Luka Drinovec, Matej Ogrin, 2020, izvirni znanstveni članek

Opis: Air pollution is not an exclusively urban problem as wood burning is a widespread practice in rural areas. As we lack information on the air quality situation in rural mountainous regions, our aim is to examine equivalent black carbon (eBC) pollution in a typical rural karst area in the settlement of Loški Potok (Slovenia). eBC mass concentrations were measured by Aethalometer (AE-33) at two sites in Retje karst depression. The rural village station was located at the bottom of the karst depression whereas the rural background station was positioned at the top of the hill. We showthe diurnal variation of equivalent black carbon mass concentrations for different seasons. In the populated karst depression, the major source of eBC pollution are households using wood as a heating fuel reaching the highest mass concentrations in winter. Diurnal pattern of eBC from biomass burning and traffic differ due to different source activity and it is influenced by typical formation of a cold air pool from late afternoon until late morning, restricting the dispersion of local emissions. The large difference in mass concentrations between the lowest part of the village (rural station) and the top of the hill (rural background station) indicates that in a vertically stratified and stable atmosphere local sources of black carbon have a major impact onair quality conditions in the area studied. Since in Alpine and Dinaric regions there are many similar inhabited areas, we can expect similar air quality conditions also in other rural hilly areas with limited self-cleaning air capacity.
Najdeno v: osebi
Ključne besede: air pollution, black carbon, hidden geographies, diurnal variation, biomass burning, relief depressions, Loški Potok, Slovenia
Objavljeno: 04.01.2021; Ogledov: 1127; Prenosov: 0
.pdf Polno besedilo (1,15 MB)

23.
Intercomparison and characterization of 23 Aethalometers under laboratory and ambient air conditions:
Björn Briel, Vadimas Dudoitis, Javier Fernández-García, Paul Buckley, Sascha Pfeifer, Maria Cruz Minguillon, Thomas Müller, Luka Drinovec, Andrea Cuesta-Mosquera, Griša Močnik, 2021, izvirni znanstveni članek

Opis: Aerosolized black carbon is monitored worldwide to quantify its impact on air quality and climate. Given its importance, measurements of black carbon mass concentrations must be conducted with instruments operating in quality-checked and ensured conditions to generate data which are reliable and comparable temporally and geographically. In this study, we report the results from the largest characterization and intercomparison of filter-based absorption photometers, the Aethalometer model AE33, belonging to several European monitoring networks. Under controlled laboratory conditions, a total of 23 instruments measured mass concentrations of black carbon from three well-characterized aerosol sources: synthetic soot, nigrosin particles, and ambient air from the urban background of Leipzig, Germany. The objective was to investigate the individual performance of the instruments and their comparability; we analyzed the response of the instruments to the different aerosol sources and the impact caused by the use of obsolete filter materials and the application of maintenance activities. Differences in the instrument-to-instrument variabilities from equivalent black carbon (eBC) concentrations reported at 880 nm were determined before maintenance activities (for soot measurements, average deviation from total least square regression was −2.0 % and the range −16 % to 7 %; for nigrosin measurements, average deviation was 0.4 % and the range −15 % to 17 %), and after they were carried out (for soot measurements, average deviation was −1.0 % and the range −14 % to 8 %; for nigrosin measurements, the average deviation was 0.5 % and the range −12 % to 15 %). The deviations are in most of the cases explained by the type of filter material employed by the instruments, the total particle load on the filter, and the flow calibration. The results of this intercomparison activity show that relatively small unit-to-unit variability of AE33-based particle light absorbing measurements is possible with well-maintained instruments. It is crucial to follow the guidelines for maintenance activities and the use of the proper filter tape in the AE33 to ensure high quality and comparable black carbon (BC) measurements among international observational networks.
Najdeno v: osebi
Ključne besede: black carbon, aerosol, absorption, filter absorption photometer, aethaloemter
Objavljeno: 03.05.2021; Ogledov: 867; Prenosov: 0
.pdf Polno besedilo (5,57 MB)

24.
The determination of source-separated black carbon emission rates using radon as a tracer of atmospheric dynamics
Janja Turšič, Griša Močnik, Irena Ježek, Matic Ivančič, Janja Vaupotič, Luka Drinovec, Asta Gregorič, 2021, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: osebi
Ključne besede: black carbon, emission rate, aethalometer, radon
Objavljeno: 17.11.2021; Ogledov: 531; Prenosov: 15
URL Polno besedilo (0,00 KB)
Gradivo ima več datotek! Več...

25.
Determination of high-time resolution mineral dust concentration in real-time by optical absorption measurements
Matic Ivančič, Irena Ježek, Martin Rigler, Asta Gregorič, Balint Alfoldy, Rok Podlipec, Luka Drinovec, Griša Močnik, 2021, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: osebi
Ključne besede: mineral dust, concentration, aerosols, air quality
Objavljeno: 17.11.2021; Ogledov: 489; Prenosov: 1
.pdf Polno besedilo (49,11 MB)
Gradivo ima več datotek! Več...

26.
Comparing black-carbon- and aerosol-absorption-measuring instruments – a new system using lab-generated soot coated with controlled amounts of secondary organic matter
Antti-Pekka Hyvärinen, Konstantina Vasilatou, Matthias Oscity, Ernest Weingartner, Bradley Visser, Jannis Röhrbein, Luka Drinovec, Daniel M. Kalbermatter, Griša Močnik, 2022, izvirni znanstveni članek

Opis: We report on an inter-comparison of black-carbon- and aerosol-absorption-measuring instruments with laboratory-generated soot particles coated with controlled amounts of secondary organic matter (SOM). The aerosol generation setup consisted of a miniCAST 5201 Type BC burner for the generation of soot particles and a new automated oxidation flow reactor based on the micro smog chamber (MSC) for the generation of SOM from the ozonolysis of α-pinene. A series of test aerosols was generated with elemental to total carbon (EC  TC) mass fraction ranging from about 90 % down to 10 % and single-scattering albedo (SSA at 637 nm) from almost 0 to about 0.7. A dual-spot Aethalometer AE33, a photoacoustic extinctiometer (PAX, 870 nm), a multi-angle absorption photometer (MAAP), a prototype photoacoustic instrument, and two prototype photo-thermal interferometers (PTAAM-2λ and MSPTI) were exposed to the test aerosols in parallel. Significant deviations in the response of the instruments were observed depending on the amount of secondary organic coating. We believe that the setup and methodology described in this study can easily be standardised and provide a straightforward and reproducible procedure for the inter-comparison and characterisation of both filter-based and in situ black-carbon-measuring (BC-measuring) instruments based on realistic test aerosols.
Najdeno v: osebi
Ključne besede: black carbon, aerosol absorption, secondary organic aerosol, coating
Objavljeno: 01.02.2022; Ogledov: 374; Prenosov: 10
.pdf Polno besedilo (752,94 KB)

27.
The impact of temperature inversions on black carbon and particle mass concentrations in a mountainous area
Miha Markelj, Maja Remškar, Martin Rigler, Irena Ježek, Kay Weinhold, Matej Ogrin, Asta Gregorič, Luka Drinovec, Andrea Cuesta-Mosquera, Honey Dawn C. Alas, Kristina Glojek, Griša Močnik, 2022, izvirni znanstveni članek

Opis: 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.
Najdeno v: osebi
Ključne besede: air pollution, black carbon, sources, temperature inversion, mountainous area
Objavljeno: 03.05.2022; Ogledov: 165; Prenosov: 0
.pdf Polno besedilo (7,11 MB)

Iskanje izvedeno v 0 sek.
Na vrh