National Repository of Grey Literature 62 records found  beginprevious21 - 30nextend  jump to record: Search took 0.02 seconds. 
Properties of Aerosol, Produced by Laser Ablation of Standard Materials for ICP-MS Analysis.
Holá, M. ; Nováková, H. ; Ondráček, Jakub ; Vojtíšek, M. ; Kanický, V.
Laser ablation (LA), together with inductively coupled plasma mass spectrometry (ICP-MS) as a detection system, has become a routine method for the direct analysis of various solid samples. The product of laser ablation contains a mixture of vapour, droplets and solid particles. All components are finally transported to a plasma by a carrier gas as a dry aerosol including mainly agglomerates of primary nanoparticles. In general, characterisation of aerosols by their particle size distribution (PSD) represents indispensable tool for fundamental studies of the interaction of laser radiation with various materials. The particle size distribution of dry aerosol originating from laser ablation of standard material was monitored by two aerosol spectrometers – Fast Mobility Particle Sizer (EEPS) and Scanning Mobility Particle Sizer (SMPS) simultaneously with laser ablation - ICP-MS analysis.\n
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Plný tet: SKMBT_C22016102412241 - Download fulltextPDF
Generation of NPS for Exposure Experiments from Copper Acetylacetone.
Moravec, Pavel ; Schwarz, Jaroslav ; Vodička, Petr ; Kupčík, Jaroslav ; Švehla, Jaroslav
Particles containing copper are emitted from smelters, iron foundries, power stations, and municipal incinerators (WHO, 1998) and also from brake linings during breaking, Kukutschová et al. (2011). Nanoparticles (NPs) of copper are ingredients in polymers, inks, and bioactive coatings inhibiting the growth of microorganisms, Cioffi at al. (2005), and CuO NPs has been used in antimicrobial textiles, Gabbay and Borkow (2006), therefore they can be easily inhaled. Even though CuO NPs were found highly toxic, Karlsson et al. (2008), in vivo studies of their toxicity are still rather rare. In this work we tested a method of long lasting nanoparticle generation from copper\nacetylacetonate (CuAA) for use in follow up exposure experiments with laboratory animals. The exposure chamber for inhalation experiments was constructed in the\nInstitute of Analytical Chemistry AS CR (Večeřa et al., 2011) and some methods of NPs generation for these experiments were already tested in our laboratory (Moravec et al., 2015, Moravec et al., 2016).
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Plný tet: SKMBT_C22016102412242 - Download fulltextPDF
Organic compounds in PM1 aerosol in Celakovice in winter 2015
Křůmal, Kamil ; Mikuška, Pavel ; Coufalík, Pavel ; Večeřa, Zbyněk
In this work the organic compounds and organic markers used for the identification of sources of aerosols were measured in PM1 in a small town Celakovice.
Long Lasting ZnO Nanoparticle Synthesis for Potential Use in Inhalation Experiments
Moravec, Pavel ; Kupčík, Jaroslav
In this work we tested the long term generation of ZnO-NPs for potential use in exposure experiments with laboratory animals. These experiments require the generation of NPs in the gas phase with appropriate number concentration (Nt>1 107 #/cm3) and geometric mean diameter (GMD<50 nm) in duration of several weeks. Several methods of gas phase ZnO-NPs synthesis using metalorganic precursors, such as zinc acetylacetonate, zinc tetramethylheptane dionate or diethylzinc were reported in the literature. However, NPs prepared from metalorganic precursor are usually more or less contaminated by elemental (EC) or organic (OC) carbon. Therefore we used metallic zinc as a precursor in this study.
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Plný tet: SKMBT_C22015102910283 - Download fulltextPDF
Urban and Suburban Intermodal Fraction of Atmospheric Aerosol in Winter 2014
Kozáková, Jana ; Schwarz, Jaroslav ; Leoni, C. ; Hovorka, J.
The aim of this study is to characterize the intermodal fraction in urban and suburban localities and estimate to what extent fine/coarse aerosol sources contribute to this fraction.
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Plný tet: SKMBT_C22015102910263 - Download fulltextPDF
Seasonal and Diurnal Variability of Aerosol Number Size Distribution, Concentration and Gaseous Pollutants in Prague City Center
Leoni, C. ; Kozáková, Jana ; Hovorka, J.
Atmospheric aerosol is one of the key urban pollutants while much attention has focused to the size fractions of smaller particle diameter - Dp. The most significant sources of primary ultrafine particles (Dp<100 nm) in urban ambient air are outdoor combustion sources: vehicles, industry and power plants. The aim of this study was to investigate the relationship between ultrafine aerosol particles and gaseous pollutants (O3, NOx) and their temporal variation, to analyse the size distribution differences and to assess the major sources of ultrafine particles in Prague city center.
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Plný tet: SKMBT_C22015102910250 - Download fulltextPDF
Organic compounds in PM1 aerosol in the Central Bohemian Region in the Czech Republic
Křůmal, Kamil ; Mikuška, Pavel ; Coufalík, Pavel ; Večeřa, Zbyněk
Contribution summarizes the concentrations of monosaccharide anhydrides, resin acids, methoxyphenols, monosaccharides, disaccharides, sugar alcohols, alkanes, hopanes, steranes and polyaromatic hydrocarbons in PM1 aerosols in small town Celakovice in winter. According to concentrations of organic markers, the identification of emission sources in Celakovice is discussed.
Influence of inhaled manganese oxides nanoparticles on mass of internal organs in mice
Zeman, T. ; Dočekal, Bohumil ; Mikuška, Pavel ; Buchtová, Marcela ; Míšek, Ivan ; Šerý, Omar ; Večeřa, Zbyněk
Results of the statistical analysis of a long-term inhalation experiment on laboratory mice are presented. During 17 weeks of the experiment, the experimental group was exposed to inhaled manganese oxides nanoparticles. Manganese oxides (MnO center dot Mn2O3) nanoparticles (MnONPs) were synthesized continuously via aerosol route in a hot wall tube flow reactor using a thermal decomposition of metal organic precursor manganese(II) acetylacetonate in the flow tube reactor (in vertical position) at temperature 750 degrees C in the presence of 30 vol% of oxygen. The concentration of produced MnONPs at the reactor output was in the range 1-3 x 10(7) particles/cm(3) and the size of generated nanoparticles MnO center dot Mn2O3 was in the range 7-50 nm. Before entering the inhalation chamber, MnONPs in the mixture of N-2, O-2 and air (at total flow rate of 3 L/min) were further diluted using filtrated humidified air (20 L/min) at temperature 21 degrees C resulting in the MnONPs concentration 2 x 10(6) particles/cm(3). At regular time intervals the mass of selected internal organs of mice from both experimental and control group was assessed. It has been proven that inhaled nanoparticles are able to influence the mass of internal organs of mice. Statistically significantly lower mass of kidneys, liver and spleen and higher mass of pancreas have been found in the experimental group compared to the control group.
Organic compounds in PM2.5 aerosol in Ostrava in winter season
Mikuška, Pavel ; Křůmal, Kamil ; Večeřa, Zbyněk
Contribution deals with the study of chemical composition of atmospheric aerosols fraction PM2.5 in Ostrava-Radvanice with focus on analysis selected organic compounds, so-called molecular markers that are used for identification of emission sources of aerosols.
Organic compounds in PM1 in Ostrava and Mlada Boleslav in winter season
Křůmal, Kamil ; Mikuška, Pavel ; Večeřa, Zbyněk
In this work the organic compounds and organic markers used for the identification of sources of aerosols were measured. Monosaccharide anhydrides and resin acids (emissions from biomass combustion) and polyaromatic hydrocarbons (emissions from traffic and incomplete combustion) were observed especially. Hopanes, steranes (traffic, coal combustion) and alkanes were next groups of analysed organic compounds.

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