Number of found documents: 23694
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Correlative probe electron microscopy analysis of plasma-treated gallium-doped zinc oxide nanorods
Rutherford, D.; Remeš, Zdeněk; Mičová, J.; Ukraintsev, E.; Rezek, B.
2024 - English
Correlative Probe Electron Microscopy (CPEM) was used to investigate the topographical and electronic emission properties of gallium-doped zinc oxide nanorods (ZnO:Ga) after low pressure hydrogen or oxygen plasma treatment. Simultaneous secondary electron (SE) and back-scattered electron (BSE) emission information from the same nanorods enabled true correlation with the topographical information obtained by atomic force microscopy (AFM). All nanorods were analyzed in-situ on the same substrate using the same experimental parameters which allowed for accurate comparison. ZnO:Ga nanorods displayed the largest SE emission intensity as well as the greatest BSE emission intensity. Hydrogen plasma treatment reduced both SE and BSE emission intensity, whereas oxygen plasma treatment only reduced SE emission. These effects may help elucidate various optical as well as biological interactions of ZnO:Ga nanorods. Keywords: correlative microscopy; SEM; AFM; ZnO nanorods; plasma treatment Available at various institutes of the ASCR
Correlative probe electron microscopy analysis of plasma-treated gallium-doped zinc oxide nanorods

Correlative Probe Electron Microscopy (CPEM) was used to investigate the topographical and electronic emission properties of gallium-doped zinc oxide nanorods (ZnO:Ga) after low pressure hydrogen or ...

Rutherford, D.; Remeš, Zdeněk; Mičová, J.; Ukraintsev, E.; Rezek, B.
Fyzikální ústav, 2024

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 ...

Salvadori, Karolína
Ústav chemických procesů, 2023

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 ...

Vásquez, Claudia
Ústav chemických procesů, 2023

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. ...

Hušek, Matěj
Ústav chemických procesů, 2023

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 ...

Paříková, Anna
Ústav chemických procesů, 2023

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 ...

Windell, Laurence Christian; Pokorná, Petra; Ondráček, Jakub; Schwarz, Jaroslav; Lhotka, Radek; Vodička, Petr; Zíková, Naděžda; Hopke, P.K.; Ždímal, Vladimír
Ústav chemických procesů, 2023

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 ...

Mašková, Ludmila; Ždímal, Vladimír; Ondráček, Jakub
Ústav chemických procesů, 2023

VE VODĚ ROZPUSTNÉ SLOUČENINY PM2.5 NA TŘECH VENKOVSKÝCH POZAĎOVÝCH LOKALITÁCH VE STŘEDNÍ EVROPĚ V CHLADNÝCH A TEPLÝCH OBDOBÍCH
Schwarz, Jaroslav; Vodička, Petr; Lhotka, Radek; Pokorná, Petra; Zíková, Naděžda; Ondráček, Jakub; Aurora, S.; Poulain, L.; Herrmann, H.; Ždímal, Vladimír
2023 - Czech
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. 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. Keywords: water-soluble compounds,; 3 sites; 12-h time resolution Available in a digital repository NRGL
VE VODĚ ROZPUSTNÉ SLOUČENINY PM2.5 NA TŘECH VENKOVSKÝCH POZAĎOVÝCH LOKALITÁCH VE STŘEDNÍ EVROPĚ V CHLADNÝCH A TEPLÝCH OBDOBÍCH

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 ...

Schwarz, Jaroslav; Vodička, Petr; Lhotka, Radek; Pokorná, Petra; Zíková, Naděžda; Ondráček, Jakub; Aurora, S.; Poulain, L.; Herrmann, H.; Ždímal, Vladimír
Ústav chemických procesů, 2023

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 ...

Kovářík, Jiří; Špalová, Anna; Roztočil, Petr; Zíková, Naděžda; Schwarz, Jaroslav; Ždímal, Vladimír
Ústav chemických procesů, 2023

Application of In situ TR Spectroelectrochemical Techniques in Determination of Redox Mechanism of Bioactive Compounds
Sokolová, Romana; Jiroušková, Eliška; Degano, I.; Wantulok, J.; Nycz, J.
2023 - English
The electron transfer reactions play an important role in many natural processes. Reactions such as \ndissociation, protonation, and reactions with water and other small molecules often occur in \nbiotransformation. The reaction schemes involving these chemical reactions coupled to the \nelectron transfer can be determined by cyclic voltammetry. Additionally, in \nsitu spectroelectrochemistry can efficiently contribute to the determination of oxidation or \nreduction mechanism. This technique provides information about the electroactive chromophore during \nthe redox process allowing to identification the first reaction intermediates. The final reaction \nproducts were identified by chromatographic techniques. This study represents a key role of TR \nspectroelectrochemistry in the determination of reaction intermediates in the case of \n1,10- phenanthroline derivative substituted by bioactive phenothiazine unit and \ndrug 3- fluorophenmetrazine (2-(3-fluorophenyl)-3-methylmorpholine, 3-FPM). Co pound 3-FPM\nhave recently appeared as the new psychoactive substance in the drug market.\n Keywords: IR spectroelectrochemistry; psychoactive substances; oxidation mechanism Available on request at various institutes of the ASCR
Application of In situ TR Spectroelectrochemical Techniques in Determination of Redox Mechanism of Bioactive Compounds

The electron transfer reactions play an important role in many natural processes. Reactions such as \ndissociation, protonation, and reactions with water and other small molecules often occur in ...

Sokolová, Romana; Jiroušková, Eliška; Degano, I.; Wantulok, J.; Nycz, J.
Ústav fyzikální chemie J. Heyrovského, 2023

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