The Accuracy of a Monofiber Optical Probe
Vejražka, Jiří; Orvalho, Sandra; Večeř, M.; Sechet, P.; Cartellier, A.
2010 - anglický
In this contribution, the accuracy of optical probe in a bubbly flow is deduced from high-speed imaging of bubble probe interaction. A dimensionless criterion useful for the estimation of the error of indicated void fraction is developed. It is also observed that the probe deformability may significantly decrease the probe accuracy.
Klíčová slova:
opticle probe; bubble-fiber interaction; measurement accuracy
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
The Accuracy of a Monofiber Optical Probe
In this contribution, the accuracy of optical probe in a bubbly flow is deduced from high-speed imaging of bubble probe interaction. A dimensionless criterion useful for the estimation of the error of ...
Photo-Electrochemical Properties of Hierarchical Nanocomposite Structure: Carbon Nanofibers/TiO2/ZnO Thin Films
Hubička, Zdeněk; Kment, Štěpán; Gregora, Ivan; Čada, Martin; Olejníček, Jiří; Klusoň, Petr; Petras, D.; Krýsa, J.; Jastrabík, Lubomír; Dytrych, Pavel
2010 - anglický
In this contribution we report on photoelectrochemical functionality of the multilayers system consisting of CNF's/photoactive anatase TiO2/ conductive ZnO thin films. Recently the thin phthalocyanines films has been prepared and studied individually.
Klíčová slova:
phthalocyanines films; multi-layers systems; photovoltaics
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Photo-Electrochemical Properties of Hierarchical Nanocomposite Structure: Carbon Nanofibers/TiO2/ZnO Thin Films
In this contribution we report on photoelectrochemical functionality of the multilayers system consisting of CNF's/photoactive anatase TiO2/ conductive ZnO thin films. Recently the thin ...
Formation Of Sn-Ag-C and Sn-Au-C Nanoalloys Through Ir Laser Ablation OF Ag and Au Target and Simultaneous Decomposition of TMT in the Gas Phase
Křenek, Tomáš; Murafa, Nataliya; Bezdička, Petr; Šubrt, Jan; Pola, Josef
2010 - anglický
IR laser ablation of Ag or Au in dielectric breakdown of tetramethyltin leads to nanostructured films composed of nanograins of Sn and amorphous Au-C or Ag-C phases.
Klíčová slova:
tetramethyltin; ir laser; ablation
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Formation Of Sn-Ag-C and Sn-Au-C Nanoalloys Through Ir Laser Ablation OF Ag and Au Target and Simultaneous Decomposition of TMT in the Gas Phase
IR laser ablation of Ag or Au in dielectric breakdown of tetramethyltin leads to nanostructured films composed of nanograins of Sn and amorphous Au-C or Ag-C phases.
Calcined Transition Metal Layered Double Hydroxides, Their Characterization and Activity in Total Oxidation of Ethanol
Jirátová, Květa; Kovanda, F.; Ludvíková, Jana; Klempa, Jan
2010 - anglický
Klíčová slova:
catalytic activity; ethanol; chemical analysis
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Calcined Transition Metal Layered Double Hydroxides, Their Characterization and Activity in Total Oxidation of Ethanol
Correlations for the Prediction of NTU and Mass Transfer Coefficient for a VPE
Rathilal, S.; Čárský, M.; Heyberger, Aleš; Rousková, Milena
2010 - anglický
Liquid-liquid extraction is the separation of the constituents of a liquid solution by contact with another insoluble liquid and belongs to the class of countercurrent diffusional separation processes, where it ranks second in importance to distillation. There are many different types of columns that are available for liquid-liquid extraction and the reciprocating column and vibrating plate column are two types of mechanically aided columns. This paper aims at developing appropriate correlations for the prediction of NTU/HETS and the mass transfer coefficient, kox for the VPE based on the agitation level of the plates (af – the product of frequency and amplitude of the plate motion), the plate spacing and the flow rates which will allow for the simplification in the design of this type of column.
Klíčová slova:
mass transfer coefficient; liquid-liquid extraction; acetone-toluene-water system
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Correlations for the Prediction of NTU and Mass Transfer Coefficient for a VPE
Liquid-liquid extraction is the separation of the constituents of a liquid solution by contact with another insoluble liquid and belongs to the class of countercurrent diffusional separation ...
Reconstructed 3D Microstructure and Effective Diffusivity of a Zeolite-Polyimide Mixed Matrix Membrane
Čapek, P.; Hejtmánek, Vladimír; Fryčová, M.; Sysel, P.; Kočiřík, Milan; Brabec, Libor; Zikánová, Arlette; Bernauer, B.; Fíla, V.
2010 - anglický
In our work we focused on a two-phase system consisting of the polyimide matrix synthesized from the monomers 4,4’-(hexafluoroisopropylidene)diphtalic anhydride (6FDA) and 4,4’-oxydianiline (ODA), and silicalite-1 [3, 4]. Its microstructure on the scale capturing the morphology of silicalite particles was reproduced by means of stochastic reconstruction. Then, effective diffusivity of an arbitrary fluid in the reconstructed composite material was determined by exploiting random walk simulation. Resulting values were compared with the corresponding values obtained using two traditional correlations for conductivity of composite materials. Image processing and analysis as the first step of stochastic reconstruction was a bit inexact in terms of an estimation of the volume fractions of both phases.
Klíčová slova:
simulation; effective diffusivity; membrane
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Reconstructed 3D Microstructure and Effective Diffusivity of a Zeolite-Polyimide Mixed Matrix Membrane
In our work we focused on a two-phase system consisting of the polyimide matrix synthesized from the monomers 4,4’-(hexafluoroisopropylidene)diphtalic anhydride (6FDA) and 4,4’-oxydianiline (ODA), ...
Experimental Study of Bubble Interactions with the Solid Surface
Zedníková, Mária; Vobecká, Lucie; Vejražka, Jiří; Růžička, Marek
2010 - anglický
The experiments were carried out in a rectangular vessel equipped with a device generating the bubbles of defined size ranging from 0.4 to 2.0 mm (Vejrazka et al., 2008). Cleaned glass was used as a hydrophilic surface and polypropylene, polyethylene and Teflon were used as hydrophobic surfaces. Deionised water with addition of sodium dodecyl sulphate was used as liquid. The collision and attachment process was observed by means of high speed camera. The following quantities were evaluated from the image sequences: impact and rebound velocities of a bubble, maximal bubble deformation during the contact with the surface and the time required for three-phase contact line formation. The experimental results were compared with our previous investigations (Fujasova-Zednikova et al., 2009).
Klíčová slova:
bubble attachment; surfactants; floation
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Experimental Study of Bubble Interactions with the Solid Surface
The experiments were carried out in a rectangular vessel equipped with a device generating the bubbles of defined size ranging from 0.4 to 2.0 mm (Vejrazka et al., 2008). Cleaned glass was used as a ...
Volumetric Mass Transfer Coefficient and Gas Holdup in Solution of Electrolyte in Different Flow Regimes in Bubble Column
Fialová, Marie; Orvalho, Sandra; Zedníková, Mária; Drahoš, Jiří; Růžička, Marek
2010 - anglický
Volumetric mass transfer coefficient, kLaL and gas holdup, εG were measured in distilled water and in solutions of Na2SO4 (both coalescent solutions and solutions with suppressed coalescence), under homogeneous and heterogeneous bubbling conditions in bubble column. Dynamic pressure step method was used for kLaL measurement. The gas holdup, εG was measured by the bed expansion method.
Klíčová slova:
gas holdup; volumetric mass transfer; bubble column
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Volumetric Mass Transfer Coefficient and Gas Holdup in Solution of Electrolyte in Different Flow Regimes in Bubble Column
Volumetric mass transfer coefficient, kLaL and gas holdup, εG were measured in distilled water and in solutions of Na2SO4 (both coalescent solutions and solutions with suppressed coalescence), under ...
Effect of Velocity on the Coalescence of Bubbles
Orvalho, Sandra; Cachaza, E.M.; Abadie, T.; Drahoš, Jiří; Růžička, Marek
2010 - anglický
The present work is focused only on the effect of the velocity of approach between the interfaces of two identical bubbles, that are brought into contact in liquids known to be either coalescent (pure water) or non-coalescent (surfactant solutions).
Klíčová slova:
effect of velocity; coalescence of bubbles
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Effect of Velocity on the Coalescence of Bubbles
The present work is focused only on the effect of the velocity of approach between the interfaces of two identical bubbles, that are brought into contact in liquids known to be either coalescent (pure ...
Parameters Affecting Process of Particles Sedimentation: III
Kulaviak, Lukáš; Růžička, Marek; Drahoš, Jiří; Hladil, Jindřich
2010 - anglický
The aim of our contribution is to study the effect of the particles properties on their settling behaviour in solid-liquid suspensions. Generally, the particles interact mutually in a complex way. They are also coupled with the motion of the liquid whose flow they generate. The resulting behaviour depends on many mechanical particle properties (roughness, shape, size, abrasive hardness, texture, fine particle presence) and electrochemical properties of the interface between the particles and water (surface tension, zeta-potential, electrostatic potential, etc.).
Klíčová slova:
contact mode; zeta-potential; adhesion
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Parameters Affecting Process of Particles Sedimentation: III
The aim of our contribution is to study the effect of the particles properties on their settling behaviour in solid-liquid suspensions. Generally, the particles interact mutually in a complex way. ...
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