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Aerosol Particles in the Indoor Environment of the National Museum
Mašková, Ludmila; Smolík, Jiří; Ondráček, Jakub; Ohlídalová, M.
2011 - Czech
The aim of this study was to investigate concentrations and sources of airborne PM in the indoorenvironment on the National Museum in the centre of Prague and in a small town Terezín, and to establish the relationship between the indoor and outdoor environment. Cílem této práce bylo zjistit jaké jsoou koncentrace ástic ve dvou různých typech vnitřního prostředí Národního muzea (NM), a to v historické budově v Praze a depozitáři v Terezíně. Dále pak definovat vztah mezi vnitřním a vnějším ovzduším a na základě těchto údajů stanovit možné zdroje částic ve vnitřním prostředí.
Keywords:
indoor environment; numerical size distribution; museum
Available at various institutes of the ASCR
Aerosol Particles in the Indoor Environment of the National Museum
The aim of this study was to investigate concentrations and sources of airborne PM in the indoorenvironment on the National Museum in the centre of Prague and in a small town Terezín, and to establish ...
Size-Dependent Rate Constant of Chemical Reactions in Nanoscale Particles
Levdansky, V.V.; Smolík, Jiří; Ždímal, Vladimír; Moravec, Pavel
2011 - English
It is known that many processes occurring in heterogeneous systems with nanoscale objects are characterized by some specific features due to size dependence of parameters describing processes in question. This can in particular affect nanoparticle formation. Some problems related to the trapping of impurity molecules by nanoparticles were considered in (Levdansky et al., 2009). Here we study the influence of the size effect on chemical reactions inside nanoparticles.
Keywords:
size effect; nanoparticles; chemical reactions
Available at various institutes of the ASCR
Size-Dependent Rate Constant of Chemical Reactions in Nanoscale Particles
It is known that many processes occurring in heterogeneous systems with nanoscale objects are characterized by some specific features due to size dependence of parameters describing processes in ...
Influence of Size Effects on Homogeneous Nucleation Inside Nanoparticles
Levdansky, V.V.; Smolík, Jiří; Ždímal, Vladimír; Moravec, Pavel
2011 - English
It is known that many physicochemical processes in aerosol systems with nanoscale particles and in nanoparticles themselves depend on the particle size. The influence of size dependence of the condensation coefficient on gas-phase nucleation was discussed in (Levdansky et al., 2010). Some problems related to nucleation in confined space, in particular the depletion effect of the ambient phase, were considered in (Kožíšek et al., 2011; Schmelzer and Abyzov, 2011). Here we study the size effects in homogeneous nucleation inside nanoparticles related to size dependence of the effective rate constant for the attachment of monomers to the critical cluster.
Keywords:
size effect; nanoparticles; chemical reactions
Available at various institutes of the ASCR
Influence of Size Effects on Homogeneous Nucleation Inside Nanoparticles
It is known that many physicochemical processes in aerosol systems with nanoscale particles and in nanoparticles themselves depend on the particle size. The influence of size dependence of the ...
AWS Viscometry – Principles and Applications
Wein, Ondřej
2011 - English
Quantitative identification of Apparent wall slip (AWS) effect, accompanying the flow of colloidal dispersions in confined geometries, requires a specific modification of common viscometric methods. Essential distinction between common and AWS viscometry is outlined – including theoretical background, calibration, data acquisition, and downstream data treatment – and demonstrated for a class of rotational viscometers.
Keywords:
AWS viscometry; adgr effects; inertia effects
Available at various institutes of the ASCR
AWS Viscometry – Principles and Applications
Quantitative identification of Apparent wall slip (AWS) effect, accompanying the flow of colloidal dispersions in confined geometries, requires a specific modification of common viscometric methods. ...
Vapor–Liquid Equilibrium in Diluted Polymer + Toluene Systems
Bogdanić, Grozdana; Wichterle, Ivan
2011 - English
Vapor–liquid equilibrium data were determined for five polymer plus toluene systems at isothermal conditions between 60 and 100 oC. Polymers comprise copolymers and terpolymers of octadecyl acrylate, acrylic acid, styrene, and 1-vinyl-2-pyrrolidone because of their practical importance as flow improvers for crude oil and/or derivatives. All-glass micro-ebulliometer with circulation of liquid phase was used for measurement of total pressure over polymer + toluene mixtures. Two predictive group contribution models (the Entropic–Free Volume and the Group Contribution–Flory) were applied to estimate phase behavior of two polymer solutions; good agreement with experimental data was achieved.
Keywords:
polymer and toluene systems; experimental data; vapor–liquid equilibrium data
Available at various institutes of the ASCR
Vapor–Liquid Equilibrium in Diluted Polymer + Toluene Systems
Vapor–liquid equilibrium data were determined for five polymer plus toluene systems at isothermal conditions between 60 and 100 oC. Polymers comprise copolymers and terpolymers of octadecyl acrylate, ...
Oscillations of a Bubble Attached to a Capillary Tip
Vejražka, Jiří; Vobecká, Lucie
2011 - Czech
The contribution provides a procedure for computing the eigenmode frequencies, shapes and dampings for the case of oscillations of a bubble or drop attached to a capillary tip. The procedure is based on the analysis of Bostwick and Steen, but its results are recast to a more convenient and more compact form. Analytical results are in a good agreement with experiments, if the bubble size is sufficiently smaller than the size at detachment due to Archimedes forces. Práce uvádí výpočetní postup pro stanovení vlastních frekvencí, tvarů a příslušných útlumů pro tvarové kmitání bubliny nebo kapky přichycené na jehle. Výpočetní postup je založen na analýze Bostwicka a Steena, jehož výsledek je algebraicky upraven do kompaktního tvaru. Výsledky výpočtu vykazují dobrou shodu s experimentem, pokud je velikost bubliny dostatečně menší než velikost při odtrhu vlivem Archimedových nebo gravitačních sil.
Keywords:
eigenmode frequencies; oscilations of a bubble; bubble size
Available at various institutes of the ASCR
Oscillations of a Bubble Attached to a Capillary Tip
The contribution provides a procedure for computing the eigenmode frequencies, shapes and dampings for the case of oscillations of a bubble or drop attached to a capillary tip. The procedure is based ...
Experimental Study of Bubble Oscillations in Solutions of Different Surfactants
Vobecká, Lucie; Vejražka, Jiří; Tihon, Jaroslav
2011 - Czech
The contribution deals with experimental study of oscillations of bubbles attached to the capillary. Příspěvek se zabývá experimentálním studiem oscilací bublin přichycených na kapiláře.
Keywords:
bubble oscillations; surfactants; energy dissipation
Available at various institutes of the ASCR
Experimental Study of Bubble Oscillations in Solutions of Different Surfactants
The contribution deals with experimental study of oscillations of bubbles attached to the capillary.
A Simplified Calculation of a Continuous Flow Packed Contactor with Help of Characteristic Times
Sovová, Helena
2011 - Czech
The proposed approach is illustrated on several examples of supercritical fluid extraction kinetics. Simple expressions for the calculation of characteristic times of both extraction and individual extraction steps are derived from mass balance equations and applied on experimental data from typical extractions from plants with supercritical CO2, as the extraction of oils from seeds or the extraction of essential oils from aromatic plants. V příspěvku je ukázáno použití tohoto přístupu na několika příkladech průběhu superkritické extrakce z rostlin. Z bilančních rovnic jsou odvozeny jednoduché vzorce pro výpočet charakteristických časů jednotlivých kroků i pro celkový charakteristický čas extrakce. Ty jsou aplikovány na experimentální data změřená při typických extrakcích rostlin superkritickým oxidem uhličitým, jako je extrakce olejů ze semen a extrakce silic z aromatických rostlin.
Keywords:
kupercritical fluid extraction; kinetics; model
Available at various institutes of the ASCR
A Simplified Calculation of a Continuous Flow Packed Contactor with Help of Characteristic Times
The proposed approach is illustrated on several examples of supercritical fluid extraction kinetics. Simple expressions for the calculation of characteristic times of both extraction and individual ...
Modeling of Partial Oxidation of Biomass Oil Suspension
Tukač, V.; Hanika, Jiří; Veselý, Václav; Kovač, D.; Lederer, J.
2011 - Czech
Mathematical modeling of complex chemical equilibrium during biowaste oil suspension gasification in pilot plant reactor was aimed in the study. Simulation results were compared with pilot plant experiments using rape meal suspension in high boiling hydrocarbons. Application for reactor design and process scale up could be realistic. Cílem práce bylo matematické modelování variant složité chemické rovnováhy při zplyňování olejové suspenze bioodpadu v poloprovozním reaktoru. Výsledky simulací byly porovnány s poloprovozními experimenty zplyňování suspenze řepkového šrotu ve výševroucí frakci uhlovodíků tak, aby byly použitelné pro návrh a zvětšování měřítka reaktoru pro takový proces.
Keywords:
gasification; pilot plant; simulation
Available at various institutes of the ASCR
Modeling of Partial Oxidation of Biomass Oil Suspension
Mathematical modeling of complex chemical equilibrium during biowaste oil suspension gasification in pilot plant reactor was aimed in the study. Simulation results were compared with pilot plant ...
29Si NMR Phenylsilane Polymer Analysis
Pinkas, Jiří; Blechta, Vratislav; Karban, Jindřich; Sýkora, Jan
2011 - English
Here we focus on the analysis od dehydrocoupling polymerization reactions of phenylsilane. the molar mass distribution depends on the catalytic system and can be easily monitored by on-flow LC-NMR experiment.
Keywords:
polymer analysis; 29Si NMR; hydrogen
Available at various institutes of the ASCR
29Si NMR Phenylsilane Polymer Analysis
Here we focus on the analysis od dehydrocoupling polymerization reactions of phenylsilane. the molar mass distribution depends on the catalytic system and can be easily monitored by on-flow LC-NMR ...
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