40 research outputs found
Analysis of Organic Markers for Identification of Sources of Atmospheric Aerosols
Předkládaná disertační práce se zabývá organickými sloučeninami (markery), které slouží pro identifikaci zdrojů aerosolů. Teoretická část podává podrobný přehled organických markerů emitovaných z nejvýznamnějších zdrojů atmosférických aerosolů (spalování biomasy, spalování fosilních paliv a doprava), o odběru vzorků aerosolů a o analýze organických markerů pomocí analytických technik. Byly sledovány především anhydridy monosacharidů (emise ze spalování biomasy) a polyaromatické uhlovodíky (emise z dopravy a z nedokonalého spalování). Další skupinou sledovaných organických markerů byly hopany a sterany (doprava, spalování uhlí) a mastné kyseliny (úprava masných výrobků). Markery byly sledovány ve velikostní frakci PM1, protože z hlediska zdravotního působení aerosolu na člověka je tato frakce nejškodlivější. Aerosoly byly odebírány ve dvou městech během zimy a léta 2009. Vysoké koncentrace aerosolu a organických sloučenin byly nalezeny v zimě vzhledem k vyššímu spalování biomasy, uhlí a jiného organického materiálu, v létě byla nejvýznamnějším zdrojem aerosolů doprava.In this work the organic markers that serve for identification of sources of aerosols are monitored. Theoretic part deals with detailed survey of organic markers emitted from the most significant sources of atmospheric aerosols (biomass combustion, combustion of fossil fuels and traffic) as well as with sampling of aerosols and analysis of organic markers by analytical techniques. Monosaccharide anhydrides (emissions from biomass combustion) and polyaromatic hydrocarbons (emissions from traffic and incomplete combustion) were observed especially. Hopanes and steranes (traffic, coal combustion) and fatty acids (cooking) were next groups of monitored organic markers. Markers were studied mainly in size fraction PM1 because this fraction of aerosols is the most harmful to human health. Aerosols were sampled in two seasons (winter and summer) in two towns in 2009. Higher concentrations of aerosols and organic compounds were found in winter season, which resulted from increased combustion of biomass, coal and other organic material while traffic was the most significant source of aerosols in summer.
Thermal effects on steels at flame cutting
The submitted article describes the effects of a thermal separation of material on the properties of the surface layers. The separation of material is an integral part of a preparation of all final products. During cutting the surface layer of the separated material is effected, which then has an influence on the sequence of the following operations. The method of thermal separation of material was selected for the experiment described in the article a method of flame cutting. The material selected for the method was a common steel ČSN 411373, which is industrially produced and processed. The effect on the material was shown by measuring micro-hardness using the micro-hardness tester DM 2D
Inhalation of ZnO nanoparticles: Splice junction expression and alternative splicing in mice
Despite the wide application of nanomaterials, toxicity studies of nanoparticles (NP) are often limited to in vitro cell models, and the biological impact of NP exposure in mammals has not been thoroughly investigated. Zinc oxide (ZnO) NPs are commonly used in various consumer products. To evaluate the effects of the inhalation of ZnO NP in mice, we studied splice junction expression in the lungs as a proxy to gene expression changes analysis. Female ICR mice were treated with 6.46 x 10(4) and 1.93 x 10(6) NP/cm(3) for 3 days and 3 months, respectively. An analysis of differential expression and alternative splicing events in 298 targets (splice junctions) of 68 genes involved in the processes relevant to the biological effects of ZnO NP was conducted using next-generation sequencing. Three days of exposure resulted in the upregulation of IL-6 and downregulation of BID, GSR, NF-kB2, PTGS2, SLC11A2, and TXNRD1 splice junction expression; 3 months of exposure increased the expression of splice junctions in ALDH3A1, APAF1, BID, CASP3, DHCR7, GCLC, GCLM, GSR, GSS, EHHADH, FAS, HMOX-1, IFN, NF-kB1, NQO-1, PTGS1, PTGS2, RAD51, RIPK2, SRXN1, TRAF6, and TXNRD1. Alternative splicing of TRAF6 and TXNRD1 was induced after 3 days of exposure to 1.93 x 10(6) NP/cm(3). In summary, we observed changes of splice junction expression in genes involved in oxidative stress, apoptosis, immune response, inflammation, and DNA repair, as well as the induction of alternative splicing in genes associated with oxidative stress and inflammation. Our data indicate the potential negative biological effects of ZnO NP inhalation.Web of Science168120019
Polyaromatic hydrocarbons, hopanes and steranes in PM1 in Brno and Šlapanice
Contribution deals with comparison of concentrations of polyaromatic hydrocarbons, hopanes and steranes in Brno and Šlapanice at two seasons (winter and summer) and identification of emission sources of aerosols in these locations
Organic compounds in PM1 aerosol in Kladno-Svermov in winter 2017
The work deals with the measurement of organic compounds and organic markers used for the identification of main aerosol sources in PM1 aerosol in a small town (Kladno-Švermov) near Prague. Monosaccharide anhydrides and resin acids (emissions from biomass combustion) were found especially. Polycyclic aromatic hydrocarbons (emissions from traffic and incomplete combustion), hopanes (traffic, coal combustion), steranes (traffic), saccharides and alkanes were other groups of analysed organic compounds
Seasonal variations of concentrations of saccharides in PM2.5 aerosol in urban area
The concentrations of saccharides (monosaccharides, disaccharides and sugar alcohols) in PM2.5 aerosol in Brno at four seasons (spring, summer, autumn and winter 2010 and winter 2011) were observed
Organic compounds and markers from coal combustion in different types of boilers used for household heating
Organic compounds (polycyclic aromatic hydrocarbons) and organic markers (hopanes) used for the identification of aerosol emission sources were measured in emissions from the combustion of hard and brown coal. Coal was combusted in different\nboilers used for residential heating in the Czech Republic, i.e., overfire boiler, boiler with down-draft combustion and automatic boiler
Determination of organic compounds in PM1 in Brno and Šlapanice
Monosaccharide anhydrides, polyaromatic hydrocarbons, hopanes, steranes and monocarboxylic acids were analysed in PM1. Contribution deals with extractions of these compounds from filters, preparations of samples, analyses by GC/MS and discussions of results of analysis
Organic compounds in PM1 in Mlada Boleslav 2013 and Ostrava 2014 in winter season
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
Chemical composition of aerosol particles in emissions from coal combustion in different boilers used for residential heating
Organic compounds (polycyclic aromatic hydrocarbons, alkanes) and organic markers (hopanes) used for the identification of aerosol emission sources were measured in emissions from the combustion of hard and brown coal. Coal was combusted in different boilers (overfire boiler, boiler with down-draft combustion and automatic boiler) used for residential heating in the Czech Republic