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Modular Microsystems for Novel Processes Research
Křišťál, Jiří ; Jiřičný, Vladimír ; Hanika, Jiří
Paper summarises results of ICPF AS CR team in application of micro-devices including microreactors for research of novel chemical processes. Experiences were reached during the international projects IMPULSE and F3 FACTORY solved in the 6th and 7th Framework Program EU. Novel chemical processes development for chemical specialties supports their higher purity. This trend represents great challenge for chemical engineers. The piece of knowledge was applied also during discussions on Strategic Research Agenda and Implementation Action Plan formulations by the Czech Technology Platform for Sustainable Chemistry founded at the Association of Chemical Industry of the Czech Republic.
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A Simplified Calculation of a Continuous Flow Packed Contactor with Help of Characteristic Times
Sovová, Helena
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.
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A New Look on the Nernst Model in Electrochemistry
Wein, Ondřej
The present paper is inspired by the electrodiffusion (ED) flow measurement, utilizing the limiting-diffusion regime (LDR) in two-electrode ED cells. The electrochemical testing and calibrations of the ED cells is based on two standard electrochemical techniques - quasi-steady voltammetry and voltage-step transient. Recently published theory of the voltage-step transient under simultaneous effect of Faradaic and Ohmic resistances is based on a suitably extended Nernst model. An analogous theory of the voltammetric experiment is presented here.
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AWS Viscosimetry of Microdispersions - Detection of Apparent Wall Slip
Pěnkavová, Věra ; Večeř, M. ; Wein, Ondřej
The rheometric data measured using three various sensor geometries (PP60, ZZ40DIN and KK-sensor) are compared in this contribution at the case of water solution of polymer welan. The KK-sensor, constructed at our department, combines advantages of geometry both plate-plate and concentric cylinder geometry. It is shown that KK-sensor is comparable to commercial sensors. It is presented for water kaolin dispersions that apparent wall slip does not disappeared neither for low consistent dispersions. The values of slip coefficients are even higher in the case of less consistent samples.
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