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Hydrogenace thymolu ve zkrápěném reaktoru
Dudas, J. ; Hanika, Jiří ; Lepuru, J. ; Barhuysen, M.
the main objective of the investigation was to collect experimental data for scale up for the hydrogenation of thymol in a trickle bed reactor. Based on bench scale data and process simulation using physico-chemical parameters and measured reaction kinetics, a pilot scale reactor has been designed during this study. One major focus of the work was the determination of the limetife of a commercially available nickel catalyst.
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Kvalitativní analýza a řízení v závislosti na vstupních úodmínkách modelu protiproudé plněné kolony
Akramov, T. A. ; Jiřičný, Vladimír ; Staněk, Vladimír
In recent papers a mathematical model of the transients of the hydrodynamic of counter-current column was formulated. It was used for describing the overshoot phenomenon on the transient profiles of liquid holdup. These overshoots were observed experimentally when the bed was exposed to a sudden increase of either gas or liquid inlet velocity. Another condition for the appearance of the overshoots was that the step change in inlet velocity brings the system in proximity of the flooding point. The formulated model could under some conditions give a good description of the time behavior of the mean liquid holdup. In particular this model is capable of predicting and describing the conditions of the overshoot phenomenon after an imposed change of inlet velocity of liquid or gas. The problem now is to find out the response of the system periodical step changes in inlets velocity of gas or liquid. .
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Asessment of the Relation between the Composition of Aerosols of Solids in Air and Their Sources on Selected Places in Prague
Tydlitát, Vratislav ; Pekárek, Vladimír ; Šyc, Michal ; Vosecký, Martin
Results of the twentyfour hour sampling of aerosols at two posts in Prague: on a street with large traffic and at a post near to cement plant are presented. In aerosols PM10 a PM2,5 adsorbed from 500 to 1000 m3 of air (20 to 40 mg) were determined contents of As,Cd, Cr,Cu, Mn, Ni, Pb, Al, Ca, Fe, K, Mg, Na, Zn by the method of atomic absorption spectrometry. From x-ray fluorescence analyze were assesed contents of Si, S and Cl.. The winter traffic is the source of aerosol wth content of NaCl and SiO2 , Fe, Ca. In the vicinity of cement plant the aerosol contents elements, which are in cement and elements fom combustion: K, Ca, Al and S.
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Modeling of Transformation of Coal-N to Nitrogen Oxides in Fluidized Bed Combustion
Svoboda, Karel ; Pohořelý, Michael
The report contains an overview of transformation phenomena and reactions for coal nitrogen leading to nitrogen oxides emissions. Initial nitrogen in volatile matter from coals is considered in three forms: NH3, HCN and N2. The precursors (NH3 and HCN) are oxidized primarily to NO and N2O and further they react with carbon, CO and NH3. The nitrogen from coal-char is directly oxidized to NO ane N2O,which can be reduced by carbon and CO. An attempt has been made to quantitatively characterize effect of coal properties and combustion conditions on nitrogen oxides emissions.
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Equilibrium Concentrations of Solutes Extracted from Plants with Supercritical CO2
Sovová, Helena
Phase equilibrium is the crucial factor for extraction feasibility and rate. In supercritical fluid extraction from plants it depends not only on extraction pressure, temperature, and solvent composition, but also on solute-matrix interaction and on mutual interactions of solutes. A new method for measurement and quantification of these phenomena is reported, as well as some results obtained in the project.
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Hranové efekty v rotační viskozimetrii. I. Systém válec-válec (Couette), newtonské kapaliny
Wein, Ondřej ; Večeř, Marek
Exact calibration factors for a series of commercially available rotational viscometers are determined by solving the related elliptic boundary-value problem for the rotational flow of Newtonian media under zero Reynolds number (creeping flow approximation). In particular, the edge-effect correction for the Z40 DIN sensor (coaxial cylinders) should be 1.085 instead of incorrect 1.100, given in the related international standard ISO 3219 (Coaxial cylinders for liquids of medium viscosity). The edge-effect correction was determined also for a new KK sensor (coaxial Morse cones) in dependence of the adjustable gap thickness.
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