No (1139)
Yes (965)
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Measurements of New Particle Formation in the Atmosphere
Špalová, Anna
2024 - English
In this work, the formation of particles and their transformation to larger sizes will be studied by measuring the concentration of molecular clusters. The measurement will take place at a rural background site National Atmospheric Observatory Košetice. At the ground level, a Neutral and Air Ion Spectrometer (NAIS) able to measure both neutral and charged clusters or particles ranging from 0.8 to 40 nm in diameter will be used together with a Particle Size Magnifier (PSM) able to measure neutral clusters as small as 1 nm in diameter up to 12 nm. Larger particles will be measured by a Scanning Mobility Particle Sizer (SMPS). At a height of 230 m above ground level, there will be another SMPS and also a nanoSMPS able to detect particles as small as 1 nm in diameter.
Available in digital repository of the ASCR
Measurements of New Particle Formation in the Atmosphere
In this work, the formation of particles and their transformation to larger sizes will be studied by measuring the concentration of molecular clusters. The measurement will take place at a rural ...
Utilization of electrochemically induced cleavage of various sulfonimides
Salvadori, Karolína
2023 - English
In this work, we describe the unexpected electrochemical cleavage of sulfonimides, providing a direct pathway to corresponding sulfonamides. For this purpose, 16 substances were synthesized and tested, reflecting the influence of different electron effects of -SO2Ph-R substituents, and the impact of the number of nosyl units present in molecules. In the case of octakis-nosylated calixarenes, the electrochemical cleavage via direct potential-controlled electrolysis was compared with conventional organic synthetic procedures. After electrolysis, all prepared sulfonamides were isolated in excellent yields.
Keywords:
sulfonimides; green chemistry procedures; electrochemisty
Available in a digital repository NRGL
Utilization of electrochemically induced cleavage of various sulfonimides
In this work, we describe the unexpected electrochemical cleavage of sulfonimides, providing a direct pathway to corresponding sulfonamides. For this purpose, 16 substances were synthesized and ...
Cultivation of Limnospira maxima and utilization of its fresh biomass in human nutrition
Vásquez, Claudia
2023 - English
This work aims to enhance productivity, efficiency and sustainability of L. maxima cultivation as well as to determine the safe microbiological conditions for the nutritional use of fresh spirulina biomass. Various parameters such as light intensity, light spectral composition, temperature, pH, CO2, and culture media composition can be optimized. A series of experiments were performed to find the most suitable configuration to cultivate L. maxima, defined by cyanobacterium productivity and yield as well as other metabolites production such as phycocyanin (C-PC) and carotenoids.
Keywords:
Limnospira maxima; fresh biomass; human nutrition
Available in a digital repository NRGL
Cultivation of Limnospira maxima and utilization of its fresh biomass in human nutrition
This work aims to enhance productivity, efficiency and sustainability of L. maxima cultivation as well as to determine the safe microbiological conditions for the nutritional use of fresh spirulina ...
Organic fluorine content and change during thermal treatmen
Hušek, Matěj
2023 - English
We have previously described how pyrolysis affected the content of selected PFAS representatives.4,5 However, we could not determine with certainty whether they were merely cleaved or mineralised. Therefore, we focused on the change in organic fluorine content (part of PFAS) and analysed its thermal behaviour in inert (sea sand) and heterogeneous (sewage sludge) material.
Keywords:
organic fluorine; sewage sludge; thermal treatment
Available in a digital repository NRGL
Organic fluorine content and change during thermal treatmen
We have previously described how pyrolysis affected the content of selected PFAS representatives.4,5 However, we could not determine with certainty whether they were merely cleaved or mineralised. ...
Separation of exosomes from polydisperse suspension in microfluidic devices
Paříková, Anna
2023 - English
The work included fine-tuning the experimental methodology, writing an in-house code for exosome tracking based on a one-way\napproach, and performing a parametric study to investigate the separation potential of the microdevice as a function of channel geometry, flow rate, and viscosity. Preliminary results show that viscoelasticmicrofluidics can be used as an alternative to conventional e xosome separation techniques.
Keywords:
separation techniques; exosomes; microfluidic devices
Available in a digital repository NRGL
Separation of exosomes from polydisperse suspension in microfluidic devices
The work included fine-tuning the experimental methodology, writing an in-house code for exosome tracking based on a one-way\napproach, and performing a parametric study to investigate the separation ...
HIGHLY-TIME RESOLVED ELEMENTAL SOURCE APPORTIONMENT OF PM2.5 AT AN URBAN TRAFFIC SITE IN PRAGUE
Windell, Laurence Christian; Pokorná, Petra; Ondráček, Jakub; Schwarz, Jaroslav; Lhotka, Radek; Vodička, Petr; Zíková, Naděžda; Hopke, P.K.; Ždímal, Vladimír
2023 - English
This work aims to quantify metal emissions from traffic at an urban traffic site in Prague, Czech Republic, identify key tracers of emissions, and investigate exhaust and non-exhaust emissions observable in fine particulate matter (PM2.5). This project signifies the first high-time resolution elemental analysis of Prague aerosols.
Keywords:
source apportionment; traffic; online
Available in a digital repository NRGL
HIGHLY-TIME RESOLVED ELEMENTAL SOURCE APPORTIONMENT OF PM2.5 AT AN URBAN TRAFFIC SITE IN PRAGUE
This work aims to quantify metal emissions from traffic at an urban traffic site in Prague, Czech Republic, identify key tracers of emissions, and investigate exhaust and non-exhaust emissions ...
INFLUENCE OF RESPIRATORY TRACT CONDITIONS ON PARTICLE SIZE DISTRIBUTIONS GENERATED BY COMMERCIALLY AVAILABLE INHALERS
Mašková, Ludmila; Ždímal, Vladimír; Ondráček, Jakub
2023 - English
Pressurized metered dose inhalers (MDI) and dry powder inhalers (DPI) are an integral part of the treatment of lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) (Vichrow et al., 2008). An important characteristic of particles dosed by MDI and DPI is particle size distribution (PSD) (Byron, 1990). This may vary depending on the formulation, but also on the temperature and relative humidity (RH) changes during the transport from the inhaler to the human respiratory tract. The aim of this study was to determine the influence of RH and inspiratory flow rates on the PSD\ncharacteristics and predict deposition efficiency of inhalable particles in the lungs.
Keywords:
number size distribution; inhaler; hygroscopicity
Available in a digital repository NRGL
INFLUENCE OF RESPIRATORY TRACT CONDITIONS ON PARTICLE SIZE DISTRIBUTIONS GENERATED BY COMMERCIALLY AVAILABLE INHALERS
Pressurized metered dose inhalers (MDI) and dry powder inhalers (DPI) are an integral part of the treatment of lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) (Vichrow et ...
WATER-SOLUBLE COMPOUNDS PM2.5 AT THREE RURAL BACKGROUND SITES IN CENTRAL EUROPE DURING COLD AND WARM PERIODS
Schwarz, Jaroslav; Vodička, Petr; Lhotka, Radek; Pokorná, Petra; Zíková, Naděžda; Ondráček, Jakub; Aurora, S.; Poulain, L.; Herrmann, H.; Ždímal, Vladimír
2023 - Czech
Ion chromatography (IC) was used to characterize water soluble compounds in PM2.5 during winter and summer campaigns at three rural sites in Central Europe in 12-hour (day/night) time resolution. Concentrations of biomass combustion aerosolsdoubled from Melpitz to Košetice in winter, sea salt exhibited opposite behaviour. Summer exhibited higher sulphates and methane sulphonic acid in Melpitz. Day to night ratios showed higher day concentrations for phosphates and compounds connected to fungal spores and bacteria, while higher night concentrations were connected to wood combustion. Ventilation index was used as an approximate measure to distinguish local and long range transported aerosols. Biomass combustion products were identified as the \nmajority of local aerosols, while sea salt as long range transported one. Iontová chromatografie (IC) byla použita k charakterizaci ve vodě rozpustných sloučenin v PM2,5 během zimní a letní kampaně na třech venkovských lokalitách ve střední Evropě v časovém rozlišení 12 hodin (den/noc). Koncentrace aerosolů ze spalování biomasy se v zimě od Melpitzu po Košetice zdvojnásobily, mořská sůl vykazovala opačné chování. V létě byly v Melpitzu zjištěny vyšší hodnoty síranů a kyseliny metansulfonové. Poměr denních a nočních koncentrací vykazoval vyšší denní koncentrace fosforečnanů a sloučenin spojených se spórami hub a bakterií, zatímco vyšší noční koncentrace byly spojeny se spalováním dřeva. Jako přibližné měřítko pro rozlišení místních a dálkově přenášených aerosolů byl použit ventilační index. Produkty spalování biomasy byly identifikovány jako většina místních aerosolů, zatímco mořská sůl jako dálkově přenášený aerosol.
Keywords:
water-soluble compounds,; 3 sites; 12-h time resolution
Available in a digital repository NRGL
WATER-SOLUBLE COMPOUNDS PM2.5 AT THREE RURAL BACKGROUND SITES IN CENTRAL EUROPE DURING COLD AND WARM PERIODS
Ion chromatography (IC) was used to characterize water soluble compounds in PM2.5 during winter and summer campaigns at three rural sites in Central Europe in 12-hour (day/night) time resolution. ...
ON OUR RECENT WORK IN STUDYING NEW PARTICLE FORMATION (NPF)
Kovářík, Jiří; Špalová, Anna; Roztočil, Petr; Zíková, Naděžda; Schwarz, Jaroslav; Ždímal, Vladimír
2023 - English
New particle formation (NPF) is increasingly gaining attention since it emerged roughly twenty years ago as a field of interest within the aerosol science. It studies the transition process between gas phase molecules, forming clusters and eventually becoming aerosol particles. Thus, this field is a multidisciplinary one, ranging from meteorology, atmospheric chemistry and physics, all the way through physical chemistry towards chemistry and physics of aerosols. \nRecent development of instrumentation techniques allows measuring of sub-5 nm particles and molecule clusters, neutral and also charged ones. Therefore, modern analytical methods based on these measurements are often used for NPF studies.
Keywords:
atmospheric aerosols; new particle formation; NAIS
Available in a digital repository NRGL
ON OUR RECENT WORK IN STUDYING NEW PARTICLE FORMATION (NPF)
New particle formation (NPF) is increasingly gaining attention since it emerged roughly twenty years ago as a field of interest within the aerosol science. It studies the transition process between ...
Methodology for identification of pollution sources using PMF for strategic decision making in air protection - update 2023
Horník, Štěpán; Sýkora, Jan; Pokorná, Petra
2023 - Czech
The presented methodology proposes utilizatíon of the spectroscopy of nuclear magnetic resonance (NMR) as another analytical technique for the identification of compounds in atmospheric aerosols. This technique makes significantly increases the number of deterined substances and thus a number of possible markers, which can be subsequently used together with other methods to identify sources of air pollution using advanced statistical\nanalysis. Among the markers determined by NMR spectroscopy there are several organic and sulfonic acids or carbohydrates, wich are characteristic for relevant sources of air pollution. The updated methodology also shows the identification of a biogenic source that previous methodologies were not able to determine. Předkládaná metodika navrhuje využití spektroskopie nukleární magnetické rezonance (NMR) jako další analytické techniky pro identifikaci sloučenin v atmosférických aerosolech. Tato technika umožňuje výrazně zvýšit počet stanovovaných látek a tfm i případný počet markerů, které lze následně ve spojení s jinými metodami využít pro identifikaci zdrojů znečištění ovzduší pomocí pokročilé statistické analýzy. Mezi markery stanovované pomocí\nNMR spektroskopie náleží různé organické kyseliny, sulfonové kyseliny nebo sacharidy, které jsou charakteristické pro příslušné zdroje znečištění. Aktualizovaná metodika také představuje identifikaci biogenního zdroje, který předcházející metodiky nedokázaly stanovit.
Keywords:
NMR spectroscopy; atmospheric aerosols; markers
Available on request at various institutes of the ASCR
Methodology for identification of pollution sources using PMF for strategic decision making in air protection - update 2023
The presented methodology proposes utilizatíon of the spectroscopy of nuclear magnetic resonance (NMR) as another analytical technique for the identification of compounds in atmospheric aerosols. This ...
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