National Repository of Grey Literature 15 records found  1 - 10next  jump to record: Search took 0.02 seconds. 
Kinetics of formation of crystalline nuclei on active centers
Kožíšek, Zdeněk ; Demo, Pavel ; Sveshnikov, Alexey
Nucleation on active centers is studied. We suggested new model: depletion of active centers is taken into account through boundary condition and thus no additional equation is needed in contrary to standard model. Our model describes corectly not only the total number of nuclei, but also nucleation rate and the size distribution of nuclei.
Seasonal variation in concentrations of metals and ions in urban aerosol in Brno and Šlapanice
Mikuška, Pavel ; Křůmal, Kamil ; Vojtěšek, Martin ; Večeřa, Zbyněk
Urban aerosol particles in the size fraction PM1 were collected in Brno and Šlapanice in winter and summer of 2009 and 2010. Aerosols were analysed for ions and metals. Local traffic in summer and coal and wood combustion during household heating in winter were identified as the main emission sources of aerosols in both towns. Secondary aerosol components formed a significant part of aerosol during the whole year.
Identification of sources of resuspended aerosol particles using statistic methods
Huzlík, J. ; Ličbinský, R. ; Mikuška, Pavel
Parallel collection of aerosol particles in size fractions PM2.5 and PM10 and street dust at the same location was performed in Ostrava and Brno during winter and summer 2009 and 2010. Identification of PM sources including resuspended PM and their contribution to overall PM concentration was done by using receptor modelling methods.
Analysis of saccharides and markers of wood combustion in atmospheric aerosols
Kubátková, Nela ; Křůmal, Kamil ; Mikuška, Pavel ; Večeřa, Zbyněk
Present study deals with the analysis of saccharides (monosaccharides, disaccharides and alditols), monosaccharide anhydrides and markers of biomass and wood combustion in atmospheric aerosol and comparison of their concentrations in term of seasons.
Determination of heavy metals in solid energetic waste
Kořínková, Alena ; Doležalová Weissmannová, H.
Determination of heavy metals (Pb, Cu and Cd) in solid energetic waste (loge ash, ash, scoria) was performed according to Tessier. Extraction proceeded at temperatures of 25°C and 40°C and metals were determined using atomic absorption spectrometer (F AAS and ET AAS).
Comparison of concentrations of organic compounds in PM1 aerosol in Brno and Šlapanice
Křůmal, Kamil ; Mikuška, Pavel ; Večeřa, Zbyněk
In this work the organic compounds and organic markers used for the identification of sources of aerosols were monitored. Monosaccharide anhydrides are emitted from biomass combustion, polyaromatic hydrocarbons from traffic and incomplete combustion, hopanes from traffic and coal combustion, steranes from traffic and fatty acids from cooking.
Generation of Binary COOx/SiO2 Nanoparticles from Organocompound Precursors
Moravec, Pavel ; Smolík, Jiří ; Bakardjieva, Snejana ; Levdansky, V.V.
In recent years cobalt and cobalt oxide nanoparticles have attracted substantial research effort because of their potential applications such as protective materials, catalysts, magnetic data recorders, batteries and gas sensors (Jang et al., 2004). To improve their functionality and biocompatibility nanoparticles are frequently coated with SiO2 (Teleki et al., 2008). In this work, we studied CoOx-SiO2 binary nanoparticles synthesis by metal organics chemical vapor deposition (MOCVD) using organo-compound precursors cobalt acetylacetonate (CoAA) and tetraethyl orthosilicate (TEOS).
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SMPS Spectra during Various Meteorological Conditions
Zíková, Naděžda ; Ždímal, Vladimír
This work describes first results of categorization of aerosol PSD according to the various meteorological conditions connected to atmospheric humidity.
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Influence of Size Effects on Homogeneous Nucleation Inside Nanoparticles
Levdansky, V.V. ; Smolík, Jiří ; Ždímal, Vladimír ; Moravec, Pavel
It is known that many physicochemical processes in aerosol systems with nanoscale particles and in nanoparticles themselves depend on the particle size. The influence of size dependence of the condensation coefficient on gas-phase nucleation was discussed in (Levdansky et al., 2010). Some problems related to nucleation in confined space, in particular the depletion effect of the ambient phase, were considered in (Kožíšek et al., 2011; Schmelzer and Abyzov, 2011). Here we study the size effects in homogeneous nucleation inside nanoparticles related to size dependence of the effective rate constant for the attachment of monomers to the critical cluster.
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Size-Dependent Rate Constant of Chemical Reactions in Nanoscale Particles
Levdansky, V.V. ; Smolík, Jiří ; Ždímal, Vladimír ; Moravec, Pavel
It is known that many processes occurring in heterogeneous systems with nanoscale objects are characterized by some specific features due to size dependence of parameters describing processes in question. This can in particular affect nanoparticle formation. Some problems related to the trapping of impurity molecules by nanoparticles were considered in (Levdansky et al., 2009). Here we study the influence of the size effect on chemical reactions inside nanoparticles.
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