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Experimentální metody studia aerosolových nanočástic.
Ždímal, Vladimír; Schwarz, Jaroslav; Ondráčková, Lucie; Ondráček, Jakub
2019 - Czech
V novém miléniu enormně vzrostly experimentální možnosti studia aerosolových částic. Nejen, že je možné určit rozdělení velikosti částic v různých metrikách, nejen, že lze určit velikostně rozlišené chemické složení, ale byly vyvinuty metody, které umožňují, aby všechny tyto úlohy byly řešeny naráz v reálném čase. Tyto metody vycházejí z několika základních fyzikálních principů: molekulární difúze založené na Brownově pohybu, elektrostatické separace definovaně nabitých částic, kondenzačního růstu částic, gravitačního usazování, urychlení částic v tryskách, setrvačné impakce a rozptylu světla na částicích.\nPokud bychom se však specificky zajímali o separaci částic o průměru menším než 100 nanometrů, výběr experimentálních metod by se podstatně snížil. Ve skutečnosti máme pouze čtyři fyzikální principy, které lze použít v tomto rozsahu velikostí s rozumnou mírou nejistoty: Brownův pohyb, elektrostatiku, impakci a kondenzaci. Pro stanovení chemického složení v daném rozmezí velikostí je nejběžněji používaná kombinace fyzikálně-chemické ionizace s hmotnostní spektrometrií, avšak rozsah kvantifikovatelných látek je značně omezen.\nV poslední době je stále důležitější sledovat expozici pracovníků aerosolovým nanočásticím. Úloha je komplikována skutečností, že pro stanovení osobní expozice je nutné odebrat vzorky přímo z respirační zóny pracovníka. Pro tuto úlohu dosud není velký výběr možností a experimentální metody se stále vyvíjejí a testují. Slibnou alternativou je stacionární měření, kde jsou nejmodernější aerosolové spektrometry umístěny v blízkosti pracovního prostoru, a z jejich údajů lze skutečnou expozici pracovníka odhadnout. Pro kvantifikaci expozice je však vhodné kalibrovat on-line přístroje srovnáním se současným osobním odběrem.\n During the last few decades, the experimental possibilities of studying aerosol particles have grown enormously. Not only is it possible to determine the particle size distribution in different metrics, not only can the chemical composition of the size-resolved aerosol be determined, but methods have been developed over the last two decades that allow all of these tasks to be handled in real time. These methods stem from several basic physical principles: molecular diffusion based on Brownian motion, electrostatic separation of particles with predictable charge, condensational growth of particles, gravitational settling, acceleration of particles in nozzles, inertial impaction, and light scattering on particles.\nHowever, if we are specifically interested in separating particles smaller than 100 nanometers in diameter, the choice of experimental methods would be substantially reduced. In fact, we have only four physical principles that can be utilized in this size range with reasonable degree of uncertainty: Brownian motion, electrostatics, impaction and condensation. For the determination of the chemical composition in a given size range, the most commonly used is a combination of physical / chemical ionization with mass detection, however, the range of quantifiable substances is greatly limited.\nRecently, exposure monitoring of workers in the production of engineered nanoparticles has become increasingly important. Here, the task is further complicated by the fact that it is necessary to sample directly from the vicinity of the worker's mouth to determine personal exposure. As far as the collection of nanoparticles in the respiratory zone is concerned, there is not yet a great choice of options, and experimental methods are still being developed and tested. A promising alternative is a stationary measurement, where state-of-the-art aerosol spectrometers are located close to the working space of the personnel, so that the actual exposure of the worker can be estimated. In this case, however, it is necessary to calibrate the on-line instruments by comparison with simultaneous personal collection.\n Keywords: aerosol; experimental methods; nanoparticles Available at various institutes of the ASCR
Experimentální metody studia aerosolových nanočástic.

V novém miléniu enormně vzrostly experimentální možnosti studia aerosolových částic. Nejen, že je možné určit rozdělení velikosti částic v různých metrikách, nejen, že lze určit velikostně rozlišené ...

Ždímal, Vladimír; Schwarz, Jaroslav; Ondráčková, Lucie; Ondráček, Jakub
Ústav chemických procesů, 2019

Origin of Atmospheric Aerosol Based on Data with Different Time Resolution at the National Atmospheric Observatory Košetice.
Pokorná, Petra; Zíková, Naděžda; Lhotka, Radek; Vodička, Petr; Makeš, Otakar; Mbengue, Saliou; Holubová Šmejkalová, Adéla; Schwarz, Jaroslav; Ondráček, Jakub; Ždímal, Vladimír
2019 - English
To improve the air quality the underlying causalities must be well understood,particularly when it comes to aspects such as PM concentration, sources and their origin. The aim of this work was to determine air pollution origin at NAOK based on atmospheric aerosol (AA) data of different time resolution measured during intensive summer campaing. Keywords: PNSD; size resolved chemical composition; source apportionment Available in a digital repository NRGL
Origin of Atmospheric Aerosol Based on Data with Different Time Resolution at the National Atmospheric Observatory Košetice.

To improve the air quality the underlying causalities must be well understood,particularly when it comes to aspects such as PM concentration, sources and their origin. The aim of this work was to ...

Pokorná, Petra; Zíková, Naděžda; Lhotka, Radek; Vodička, Petr; Makeš, Otakar; Mbengue, Saliou; Holubová Šmejkalová, Adéla; Schwarz, Jaroslav; Ondráček, Jakub; Ždímal, Vladimír
Ústav chemických procesů, 2019

Studium mokré depozice atmosférickjého aerosolu s využitím horizontálních hydrometeorů.
Zíková, Naděžda; Pokorná, Petra; Pešice, Petr; Sedlák, Pavel; Ždímal, Vladimír
2019 - Czech
Atmosférický aerosol (AA) ovlivňuje nejen vznik oblačnosti, ale také další vlastnosti oblaků. Interakce mezi AA a oblačností může být zkoumána i u mlh, resp. nízké oblačnosti. Příkladem stanice vhodné k takovému výzkumu je stanice Milešovka, kde se mlha (nebo nízká oblačnost) nachází 55 % času (Fišák, Tesař, & Fottová, 2009). Zde proto bylo provedeno měření za účelem popisu vlivu mlh na početní velikostní distribuce AA a aktivovaných nukleačních jader.\n\n Processes between atmospheric aerosol (AA) and clouds, source of large uncertainty in weather and climate changes estimations, were described on fogs at Milešovka, meteorological observatory of the Institute of Atmospheric Physics. For the description of the AA properties, online measurement of outdoor particle number size distribution (PNSD) in the size range 10 nm – 20 μm was conducted using SMPS and APS spectrometers. The sampling system consisted of a heated whole air inlet, and PM2.5 sampling head, being switched by an automatic valve. From the difference between PNSD sampled by whole air inlet and by PM2.5 inlet, PNSD of activated particles (aPNSD) was calculated. The aPNSDs differ with hydrometeor type and depend on air mass history, with a stronger influence on freezing fog AA. Keywords: atmospheric aerosols; fog; wet deposition Available in a digital repository NRGL
Studium mokré depozice atmosférickjého aerosolu s využitím horizontálních hydrometeorů.

Atmosférický aerosol (AA) ovlivňuje nejen vznik oblačnosti, ale také další vlastnosti oblaků. Interakce mezi AA a oblačností může být zkoumána i u mlh, resp. nízké oblačnosti. Příkladem stanice vhodné ...

Zíková, Naděžda; Pokorná, Petra; Pešice, Petr; Sedlák, Pavel; Ždímal, Vladimír
Ústav chemických procesů, 2019

NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosols.
Horník, Štěpán; Schwarz, Jaroslav; Ždímal, Vladimír; Sýkora, Jan
2019 - English
Water-soluble organic compounds represent up to 80% of all organic compounds present in atmospheric aerosols. Unlike composition of inorganic compounds or volatile organic compounds, which seems to be well explored, the knowledge about WSOC composition is still rather limited. The most frequently used method for WSOC analysis is GC-MS, which is a very sensitive technique. However, the analysis of polar compounds via GC-MS requires derivatization and the quantification is extremely time consuming. The second widely used technique is ion chromatography (IC). Nowadays, IC is routinely used for analysis of specific groups of organic compounds such as carboxylic acids, amines or carbohydrates. On the other hand, there is NMR spectroscopy as a fully quantitative but rather insensitive method. NMR spectroscopy was for the purpose of aerosol chemistry employed only recently as this technique has undergone rapid development and sensitivity gain of late. So far, the use of NMR spectroscopy is mainly restricted to socalled Functional Group Analysis, of which main interest lies elsewhere than in identification of individual compounds. Keywords: NMR; aerosolomics; organic composition Available in a digital repository NRGL
NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosols.

Water-soluble organic compounds represent up to 80% of all organic compounds present in atmospheric aerosols. Unlike composition of inorganic compounds or volatile organic compounds, which seems to be ...

Horník, Štěpán; Schwarz, Jaroslav; Ždímal, Vladimír; Sýkora, Jan
Ústav chemických procesů, 2019

Measurement of Cloud Condensation Nuclei Concentrations at National Atmospheric Observatory Košetice.
Moravec, Pavel; Ondráček, Jakub; Pokorná, Petra; Ždímal, Vladimír
2019 - English
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. Keywords: atmospheric aerosols; cloud condensation nuclei; cloud condensation nuclei counter Available in a digital repository NRGL
Measurement of Cloud Condensation Nuclei Concentrations at National Atmospheric Observatory Košetice.

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 ...

Moravec, Pavel; Ondráček, Jakub; Pokorná, Petra; Ždímal, Vladimír
Ústav chemických procesů, 2019

Thermodynamic Study of Water Activity in Atmospheric Aerosol Particles.
Asadzadeh, Behnaz; Bendová, Magdalena; Ždímal, Vladimír
2019 - English
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 Keywords: atmospheric aerosols; hygroscopicity; thermodynamics Available in a digital repository NRGL
Thermodynamic Study of Water Activity in Atmospheric Aerosol Particles.

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 ...

Asadzadeh, Behnaz; Bendová, Magdalena; Ždímal, Vladimír
Ústav chemických procesů, 2019

Application of Cross-Section Filtration to Detect and Correct Errors Caused by Technical Problems in SMPS.
Wagner, Zdeněk; Kovanic, P.; Zíková, Naděžda; Ondráček, Jakub; Schwarz, Jaroslav; Ždímal, Vladimír
2019 - English
The aim of the work is thus development of a robust algorithm for detection of such errors and their fully automatic correction. The algorithm should be fast so that it could be applied in real time. Keywords: mathematical gnostics; scanning mobility particle sizer; cross-section filtration Available in a digital repository NRGL
Application of Cross-Section Filtration to Detect and Correct Errors Caused by Technical Problems in SMPS.

The aim of the work is thus development of a robust algorithm for detection of such errors and their fully automatic correction. The algorithm should be fast so that it could be applied in real time.

Wagner, Zdeněk; Kovanic, P.; Zíková, Naděžda; Ondráček, Jakub; Schwarz, Jaroslav; Ždímal, Vladimír
Ústav chemických procesů, 2019

Pokročilé techniky čištění knih a rukopisů.
Mašková, Ludmila; Smolík, Jiří; Jandová, Věra; Sokolová, M.; Jadlovská, A.; Vávrová, P.; Součková, M.; Neoralová, J.; Fajgar, Radek
2019 - Czech
Keywords: laser cleaning; pneumatic surface cleaning; historical documents Available in a digital repository NRGL
Pokročilé techniky čištění knih a rukopisů.

Mašková, Ludmila; Smolík, Jiří; Jandová, Věra; Sokolová, M.; Jadlovská, A.; Vávrová, P.; Součková, M.; Neoralová, J.; Fajgar, Radek
Ústav chemických procesů, 2019

Visible Light Promoted Derivatizations of Helicenes.
Jakubec, Martin; Storch, Jan; Ghosh, I.; König, B.
2019 - English
We developed new reductive and oxidative approaches to late-stage derivatization exploiting intrinsic photochemistry of helicenes with emphasis on the use of very simple and readily available bromo- and aminohelicenes. Keywords: helicenes; chirality; photochemistry Available in a digital repository NRGL
Visible Light Promoted Derivatizations of Helicenes.

We developed new reductive and oxidative approaches to late-stage derivatization exploiting intrinsic photochemistry of helicenes with emphasis on the use of very simple and readily available bromo- ...

Jakubec, Martin; Storch, Jan; Ghosh, I.; König, B.
Ústav chemických procesů, 2019

NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosol Samples.
Horník, Štěpán; Schwarz, Jaroslav; Ždímal, Vladimír; Sýkora, Jan
2019 - English
In the recent study, the summer and winter aerosol samples were analyzed using NMR aerosolomics approach. The samples were collected in Prague-Suchdol during summer 2008 and winter 2009 in two different particle size fractions - PM2.5 and PM 10. Around 50 compounds were identified in each aerosol spectrum owing to the comprehensive library. The profile of 86 identified compounds, which were identified in the samples altogether, served as an input data for statistical analysis. Multivariate statistical analysis clearly discriminates the two groups studied. Furthermore, it is possible to determine the most significant compounds. Keywords: atmospheric aerosols; organic compounds; analysis Available in a digital repository NRGL
NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosol Samples.

In the recent study, the summer and winter aerosol samples were analyzed using NMR aerosolomics approach. The samples were collected in Prague-Suchdol during summer 2008 and winter 2009 in two ...

Horník, Štěpán; Schwarz, Jaroslav; Ždímal, Vladimír; Sýkora, Jan
Ústav chemických procesů, 2019

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