|
| |
|
|
Ultrafine Particle Concentrations: Importance of Local Sources and New Particle Formation in Two Central European Cities
Wonaschuetz, A. ; Wagner, R. ; Aschauer, I. ; Haindl, R. ; Ludwig, W. ; Zecha, G. ; Ondráček, Jakub ; Vodička, Petr ; Zíková, Naděžda ; Ždímal, Vladimír ; Schwarz, Jaroslav ; Hitzenberger, R.
In this study, the importance of local primary sources and new particle formation as sources of fine and ultrafine particles is investigated for winter and summer in two central European cities. Particular attention is given to the impact of local meteorological characteristics: air mass origins play a large role in the characteristics of the background aerosol and the concentrations of trace gases associated with new particle formation and growth, and precipitation and thus the condensational sink.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22013091713550 - PDF
|
|
|
A 19m Deep Well – a Downward Thermal Diffusion Cloud Chamber?
Holub, R.F. ; Hopke, P.K. ; Hovorka, J. ; Otahal, P. ; Ždímal, Vladimír
An unusual phenomenon, first observed on a clear summer day after several rainy days, were droplets constantly hitting the water surface in a 19 m deep and 2.4 m diameter water well. This droplet formation was occurring during the night as well. Since the droplet formation was near continuous, we called it “the eternal rain”. The water well is about 230 years old and located in the Benedictine monastery in Broumov, Czech Republic.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013091713150 - PDF
|
|
|
Comparability of Methods to Measure Black and Elemental Carbon in Two European Urban Areas - Site and Seasonal Similarities and Differences
Hitzenberger, R. ; Schwarz, Jaroslav ; Aschauer, I. ; Haindl, R. ; Ludwig, W. ; Wagner, R. ; Wonaschuetz, A. ; Zecha, G. ; Ševčíková, Irena ; Vodička, Petr ; Zíková, Naděžda ; Ždímal, Vladimír
The goal of the current study is to investigate whether similar conversion factors are applicable at the sites and whether the conversion factors obtained earlier (i.e. ca. 10 years ago) for Vienna are still valid or whether changing source conditions have resulted in shifts of the carbonaceous fractions of the aerosol that would require a new set of conversion factors.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013091712210 - PDF
|
|
|
Number Concentration and Modal Structure of Indoor/Outdoor Fine Particles in Four European Cities
Lazaridis, M. ; Eleftheriadis, K. ; Ždímal, Vladimír ; Schwarz, Jaroslav ; Wagner, Zdeněk ; Ondráček, Jakub ; Drossinos, Y. ; Glytsos, T. ; Vratolis, S. ; Torseth, K. ; Smolík, Jiří
Indoor/outdoor measurements campaigns were performed in naturally ventilated houses and offices in four European cities to investigate the relationship between indoor and outdoor particle number concentrations and aerosol modal structures. The measurements sites were located in Oslo (Norway), Prague (Czech Republic), Milan (Italy) and Athens (Greece). A number of ordinary indoor activities (cooking, smoking, candle burning, etc.) were performed during the measurements to quantify the contribution of particles emitted from indoor sources and the contribution of outdoor particles to the change of the indoor aerosol size spectra.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013091712000 - PDF
|
|
|
Air Mass Back Trajectories and Dry Atmospheric Aerosol Mass Size Distributions in Prague
Schwarz, Jaroslav ; Štefancová, Lucia ; Maenhaut, W. ; Smolík, Jiří ; Ždímal, Vladimír
Ambient aerosol size distribution is an important factor influencing aerosol behavior and properties including particle deposition in lungs and aerosol influence on clouds. Both influences are also driven by aerosol hygroscopicity. Cascade impactors used for size resolved determination of chemical composition suffer from changes of ambient RH during sampling. Due to this factor the same particle might be deposited at different impactor stage when it is sampled at noon at 40% RH or in the early morning at 99% RH. Therefore, we used a diffusional aerosol dryer and a 7-stage modified Berner low pressure impactor with a back-up filter during the heating campaigns in 2008. The samples were analyzed for water-soluble ions (Cl-, SO42-, NO3-, Na+, NH4+, K+, Mg2+, Ca2+) and water-soluble organic carbon as a main species that influence aerosol hygroscopicity. Due to the drying, the aerosol size distributions were not influenced by the daily variability of ambient relative humidity.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013091814570 - PDF
|
|
|
Comparison of Mass Size Distribution of PM and Ions in Prague and Vienna in Winter and Summer
Schwarz, Jaroslav ; Zíková, Naděžda ; Vodička, Petr ; Ševčíková, Irena ; Kugler, Josef ; Wonaschuetz, A. ; Aschauer, I. ; Ludwig, W. ; Haindl, R. ; Zecha, G. ; Hitzenberger, R. ; Ždímal, Vladimír
The results we obtained on mass size distributions of mass and water soluble ions exhibit common basic features of ambient aerosols in Central Europe. E.g., mass size distributions in winter were dominated by a fine mode. Sulfates and ammonium were almost exclusively present in the fine mode, fine nitrates were mostly low in summer due to high summer temperatures, but they had always a distinct coarse mode. Normal size distributions of ammonium and sulfates were often almost identical in summer due to low nitrates.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013091714380 - PDF
|
|
|
Possible way to prepare nanoparticles from aerosols released at plasma deposition
Brožek, Vlastimil ; Mastný, L. ; Moravec, Pavel ; Ždímal, Vladimír
During plasma deposition of powdered metals or inorganic compounds using WSP® generator, they interact with the plasma having temperature between 25000 and 30000 K. As a result, they melt, evaporate, thermally decompose, get ionized and/or react chemically both with plasma-forming medium and with the surrounding atmosphere or carrier gas. An experimental apparatus was constructed enabling us to capture aerosol particles emitted from the surface of the free flying particles (FFP) heated in a stream of plasma. In this work we studied content, composition and size distribution of nanosized particles of Ag and oxides of Al, Ti, Cr and W, released during plasma deposition process. These particles were analyzed by dynamic light scattering - photon correlation spectroscopy using instrument MALVERN, and with aerosol spectrometers SMPS 3936 and APS 3321.Concentration of aerosols containing nanoparticles of silver or metal oxides with diameters below 100 nm was found to be in the range 85 to
|
|
|
Diffusion Battery – The Renewed Aerosol Spectrometer for Nanoparticles
Holubová Šmejkalová, A. ; Ondráček, Jakub ; Zíková, Naděžda ; Ždímal, Vladimír
The aim of the experiments was to develop new control software for the diffusion battery model DB 3040, in order to optimize measurements with this device. The software allows for larger variability of key control parameters of the diffusion battery and re-opens its application beyond determination of activity size distributions. In comparison with the most widely used method of aerosol spectrometry based on electrical mobility of particles, the method of diffusion battery can be advantageous in situations where we need to measure aerosols of relatively low concentrations with size distributions peaking bellow 20 nanometers.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013010916340 - PDF
|
|
|
Penetration of Commercial Filter Materials in Detailed Study
Ondráček, Jakub ; Zíková, Naděžda ; Ždímal, Vladimír
Testing of various filter materials proved the functionality, good precision and reproducibility of a home-made filter tester. The measurements of penetration for standard commercial filter materials might be useful for many scientists and other users working with these materials. The comparison of penetration for different types of filtration materials showed wide variety of penetration curves, MPPS and the maximum penetration. This study also confirmed our initial doubts about the standard filter efficiency testing method, regarding the used testing material, setting of MPPS and measuring only the total penetration of a polydisperse aerosol. Therefore, such a study could serve also as a basis for improvements in the filter efficiency standard method, which seems to give insufficient and in some perspectives limited or even misleading information.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22012102615351 - PDF
|
guest ::
RSS feed.