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Metodika navrhování řasových fotobioreaktorů: matematické modelování hydrodynamického míchání a předpověď parametrů světelného režimu
Papáček, Š. ; Rálek, P. ; Kopecký, Jiří ; Masojídek, Jiří ; Štys, Dalibor ; Petera, K.
Computational fluid dynamics (CFD) and process simulation are important tools for the design and optimisation of biochemical processes. In this contribution, the photobioreactor design methodology based on CFD is proposed. A widely used CFD package (Fluent 6.1, by Fluent Inc.) performs a numerical approximation of microalgae trajectory (pathline) inside tubular photobioreactor. Consequently, prediction of the level of hydrodynamic mixing and corresponding light regime inside the photobioreactor with effective use of strong light by high-density algal culture is possible. In the first approach, the algal suspension is considered as a single-phase incompressible viscous Newtonian fluid, which fills the whole section of the photobioreactor photic zone. Coupling the cell trajectories with the corresponding light conditions, the light histories of single cells are obtained. These records contain complete information about light regime in photobioreactor. Computer simulations for various photobioreactor design parameters and operating conditions allow to establish the quantitative relation between variables representing design and operating parameters and light regime parameters. Thus the problem of optimal PBR design could be resolved.
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Jan Patočka about the Appaerence as such: Phenomenology or metaphysics?
Novotný, Karel
The thematisation of the appearence as such in the work of Jan Patočka could by characterised by a tension between the intention to study nothing but the phenomenality and the need of an ontological reflexion upon the roots of phenomenality. This later intention leads Patočka to the limitss of phenomenology and into the neighbourhood of metaphysics.
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Lasery s tenkými InAs vrstvami v GaAs - absorpce a elektroluminiscence
Mačkal, Adam
Contribution presents the electroluminescence, photoabsorption and polarization properties of semiconductor lasers with thin strained InAs layers in GaAs at elevated temperature (above 25.sup.o./sup.C). The lasers exhibit high optical recombination efficiency, low threshold current density and wide temperature operation range
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Zařízení pro měření tepelné emisivity při nízkých teplotách
Králík, Tomáš ; Hanzelka, Pavel ; Musilová, Věra ; Srnka, Aleš
In the described device, the thermal emissivity or absorptivity of the sample is measured by substitution of the radiative heat flow between two parallel surfaces by thermal output of a heater. Fast measurements of the mutual emissivity for the range of the temperature of the radiating surface 25 K - 150 K are possible. The absorbing surface has a temperature between 5 K and 10 K when LHe is used as cryoliquid. The desired measurement sensitivity is 1 mK for temperature and 0.1 mikroW for heat power, respectively. The diameter of the whole device is 50 mm and so it is possible to use a commercial Dewar can for the cooling. The form of the sample is a circular plate 40 mm in diameter and 1 mm in thickness with one tested side. The emissivity and its temperature dependence for various surface treatments can be checked immediately before application in a cryogenic system
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