National Repository of Grey Literature 25 records found  previous11 - 20next  jump to record: Search took 0.01 seconds. 
Source apportionment of equivalent black carbon (ebc) at a regional blackground site in central europe
Mbengue, Saliou ; Šerfözö, Norbert ; Schwarz, Jaroslav ; Zíková, Naděžda ; Holubová, Adéla ; Holoubek, I.
This study focuses on a 5-year measurement of equivalent Black carbon (EBC) at a regional background site in Central Europe. The aim is to identify the potential sources of EBC, especially fossil fuel (ff) and biomass burning (bb). Measurements of EBC in PM10 were performed from September 2012 to December 2017 at NAOK (National Atmospheric Observatory Košetice, 49°35ʹ N, 15°05ʹ E), central Czech Republic, with a 7-wavelength aethalometer (AE31, Magee Scientific). The aethalometer model, based on the wavelength dependence of light absorption (Angstrom coefficient), has been used to estimate EBCbb (EBC from biomass burning) and EBCff (EBC from traffic). The influence of local and distant sources has been investigated using the Conditional Probability Function (CPF) and Backward Trajectories Cluster Analysis (BTCA).\nClear seasonal, diurnal and weekly variations of EBC were observed at the NAOK that could be related to the sources fluctuations and transport characteristic. The higher concentrations of EBC were measured during winter (1.00 ±0.87 μg m-3) in comparison with summer (0.44 ±0.29 μg m-3).\n
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Plný tet: SKMBT_C22020011314380 - Download fulltextPDF
A 5 year´s source apportionment study of black carbon from biomass burning and fossil fuel combustion at a rural background site
Mbengue, Saliou ; Šerfözö, Norbert ; Schwarz, Jaroslav ; Zíková, Naděžda ; Holubová, Adéla ; Holoubek, Ivan
The impacts of Black Carbon (BC) on adverse public health and Earth’s climate system have been recognized and evidenced in recent decades. Most of the studies on BC were conducted in urban/traffic areas. There are relatively few studies using real-time measurements of BC at rural background areas, especially in Central Europe. This study is a 5-year characterization of BC from biomass burning (BCbb) and fossil fuel combustion (BCff) at the National Atmospheric Observatory Košetice (49°35ʹ N, 15°05ʹ E), in central Czech Republic. The measurements of BC in PM10 were performed at 4 m above the ground with a multiple wavelength aethalometer (AE31, Magee Scientific). Paralell measurement of trace gases (NO2, NOx and SO2), biomass burning tracers (levoglucosan and mannosan) and meteorological parameters (temperature, wind speed and direction) were also performed at the station.
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Plný tet: SKMBT_C22019110512331 - Download fulltextPDF
The origin of air pollution on the basis of one year measurements of PM2.5 and PM10 at two urban background stations in Prague
Schwarz, Jaroslav ; Pokorná, Petra ; Rychlík, Š. ; Škáchová, H. ; Smolík, Jiří ; Ždímal, Vladimír ; Vlček, O. ; Hůnová, I.
The particulate matter (PM) mass concentration in cities corresponds to the sum of the concentrations measured at the background stations and the difference between the city and background stations. For this reason, at high background concentrations of PM, the result of emission reduction measures is low. Most of the reported episodes of increased PM concentrations in winter in central European cities are caused by sources of local or regional origin from the combustion of coal and / or biomass for heating purposes. Improvement of air quality in cities is possible provided that causality is understood, especially when it comes to atmospheric aerosol and its concentration, sources and origin.\nThe aim of the work was to determine the origin of air pollution in Prague on the basis of one year parallel measurements of atmospheric aerosol at two urban background stations.\n\n
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Plný tet: SKMBT_C22020011314370 - Download fulltextPDF
Comparison of chemical composition and sources at rural background station between 1993/1994/1995 and 2009/2010: Effect of legislative measures and economic transformation on air quality.
Pokorná, Petra ; Schwarz, Jaroslav ; Krejčí, R. ; Swietlicki, E. ; Havránek, Vladimír ; Ždímal, Vladimír
Presented data of the chemical composition of PM2.5 from the first half of the 1990s are the basis for evaluation of legislative measures and economic development on air quality in the Czech Republic during the last two decades. The aim of this work is to compare the chemical composition and sources of PM2.5 at the rural background station, determined in 2009/2010, with the situation in 1993/1994/1995.
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Plný tet: SKMBT_C22020011314362 - Download fulltextPDF
Thermodynamic Study of Water Activity in Atmospheric Aerosol Particles.
Asadzadeh, Behnaz ; Bendová, Magdalena ; Ždímal, Vladimír
Atmospheric aerosols are complex mixtures of various inorganic−organic compounds and play significant roles in atmospheric chemistry, earth’s climate, and global radiation budget as well as in human health. Hygroscopicity is the ability of the particle to uptake water from surrounding environment. Hygroscopicity can directly control the size distribution, chemical reactivity, and phase state of aerosol particles and thus contribute to radiative forcing on the climate system, including both the direct forcing by absorbing or scattering light and indirect forcing through activation of cloud condensation nuclei (CCN). Interactions between inorganic−organic may have a crucial impact on the hygroscopic behaviour of aerosol droplets and lead to discrepancies from ideal thermodynamic behavior. The non-ideality of mixtures in aerosol particles influences the gas-particle partitioning and affects the physical state of the condensed phase, potentially leading to liquid-liquid phase separation. Thermodynamic models are key tools to gain insight into the non-ideal behavior of organic-inorganic mixtures. By means of activity coefficients, non-ideal behaviour can be taken into account. In this study we developed a thermodynamic segment-based local composition model named NRTL (Non Random Two Liquid) to describe the aktivity coefficients of organic and inorganic aerosol particles.\n
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Plný tet: SKMBT_C22019110512053 - Download fulltextPDF
Measurement of Cloud Condensation Nuclei Concentrations at National Atmospheric Observatory Košetice.
Moravec, Pavel ; Ondráček, Jakub ; Pokorná, Petra ; Ždímal, Vladimír
In this presentation, we report first experience and results of CCN measurements using Dual Column Cloud Condensation Nuclei Counter at the National Atmospheric Observatory Košetice (NAOK), a rural background site in the Czech Republic.
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Comparison of Winter Biomass Burning Source Contribution at National Atmospheric Observatory Košetice Based on AMS and Aethalometer Data.
Schwarz, Jaroslav ; Vodička, Petr ; Zíková, Naděžda ; Mbengue, Saliou ; Šerfözö, Norbert ; Pokorná, Petra ; Makeš, Otakar ; Ždímal, Vladimír
Although atmospheric aerosol concentrations exhibit decreasing trend in last decades, the contribution of aerosol emitted by biomass combustion is opposite due to increasing wood combustion used for residential heating. Previous works determined that the share of aerosol of biomass burning origin was up to 50 % in winter. In this work, the data from aerosol mass spectrometer (AMS) and Positive Matrix Factorization (PMF) are used to elucidate biomass combustion aerosol impact at National Atmospheric Observatory Košetice (NAOK) and the results are compared with simple aethalometer model approach.
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Plný tet: SKMBT_C22019110512051 - Download fulltextPDF
On-line Measurements of Very Low Concentrations of EC/OC Aerosols at a Finish Sub-Arctic Backround Station.
Vodička, Petr ; Schwarz, Jaroslav ; Brus, David ; Ždímal, Vladimír
In this work, we tested the possibilities of an on-line Sunset Lab. EC/OC analyser during measurements when aerosol concentrations were close to detection limits declared by the manufacturer.
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Identification of Sources of Polycyclic Aromatic Hydrocarbons in Central Europe.
Lhotka, Radek ; Pokorná, Petra ; Zíková, Naděžda
This study evaluates the trends and sources of polycyclic aromatic hydrocarbons (PAH) monitored at National atmospheric observatory Košetice (NAOK), a rural background site. In total, 14 PAH concentrations in particulate matter (PM10) between 2006 and 2016 were evaluated. The highest concentrations of all PAH were measured at the beginning of the study period, in 2006. The positive matrix factorization (EPA PMF 5.0) was used to determine the sources of PAH at NAOK, with three factors resolved. The probable origin areas of PMF factors were identified by Conditional Bivariate Probability Function method (CBPF) and Potential Source Contribution Function method (PSCF) methods. NAOK is affected by local sources of PAH, as well as by regional and long-range transport.
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Plný tet: SKMBT_C22019110511050 - Download fulltextPDF
Comparison of Atmospheric Aerosol Sources at Suburban and Rural Stations
Makeš, Otakar ; Schwarz, Jaroslav ; Vodička, Petr ; Ždímal, Vladimír
This article discusses source apportionment analysis of fine aerosol fraction measured by C-ToF AMS at two different sites. The result of the analysis is a comparison of the aerosol sources between suburban and background sites during summer and winter season.
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Plný tet: SKMBT_C22018110212462 - Download fulltextPDF

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