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Mathematical Modeling of the Movement of the Solid Phase using Software LIGGGHTS
Jirounková, K. ; Havlica, Jaromír ; Kohout, M.
The main aim of this work was using the open-source software LIGGGHTS for desribing the solid phase behaviour. This software package is based on the discrete element method (DEM), where every particle consists of an asseblies of spheric particles. Each of these particles is linked to the others and their move is characterised by their ceter of gravity. There were described the basic examples by using softwarepackage LIGGGHTS; such as creating the granular layer and its mixing by using different types of the stirrer.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22014022814090 - PDF
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Novel Catalysts with Hierarchical Pore Structure: Preparation and Evaluation of the Transport Characteristics
Soukup, Karel ; Louis, B. ; Losch, P. ; Boltz, M. ; Yun, H.S. ; Song, I.-H.
It was found that the final morphology of the zeolite crystals depends on the preparation conditions (using template, the final synthesis time, pH of the solution, molar ratios of the components). While the synthesis of MFI / SiC required the presence of an additional Si-containing source, in contrast, ANA / SiC composites have been obtained through the self-recrystallization of the silicon contained in the alfa-SiC substrate.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013110613401 - PDF
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Preparation and Characterization of Nanofibrous Catalysts for Environmental Applications
Soukup, Karel ; Topka, Pavel ; Hejtmánek, Vladimír ; Petráš, D. ; Šolcová, Olga
The aim of the study was focused on detailed description of the influence of the preparation of palladium and platinum catalysts supported on polymeric nanofibers based on poly(2,6-dimethyl-1,4-phenylene) oxide on their catalytic performance. The catalytic activity of the prepared electrospun catalysts was investigated by means of model reaction based on total oxidation of methanol. Nanofibrous catalyst supports were prepared by electrospinning technique, which represents currently the most using method to produce polymeric nanofibrous mats. This technique is based on the polymeric fiber elongation under the influence of the electrostatic field between two opposite charged electrodes (capillary electrode and the grounded plate).
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013110613400 - PDF
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Application of the Electrodiffusion Method for Near-Wall Flow Diagnostics
Tihon, Jaroslav
The electrodiffusion method is presented as a measuring technique suitable for the flow measurement done in close proximity of the wall, thus in the region difficultly accessible by standard anemometric techniques (e.g. PIV, LDA). The experimental results obtained in different flow configurations (backward-facing step flow, wavy film flow, turbulent channel flow, rising Taylor bubbles) document application capabilities of this technique, e.g. for mapping of wall shear stresses, delimitation of stable flow-recirculation zones, detection of short-time reversal of the near-wall flow, investigation of the near-wall turbulence, or detection of moving fluid particles. A new technology of sensor fabrication based on photolithography is introduced and possible applications of microsensors in microfluidic devices discussed.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013110513500 - PDF
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Extraction of beta-Sitosterol from the Stinging Nettle Root with Supercritical CO2
Sajfrtová, Marie ; Bártlová, Milena ; Sovová, Helena
The stinging nettle root contains both polar and non-polar biologically active substances. beta-Sitosterol (BS), the most important component of its neutral lipids, is active in the root extracts used for various alternative medicine treatments, including the reduction of enlarged prostate. Dry roots contaning 0.28 g/kg BS were extracted with CO2 at pressure 12-60 MPa and temperature 40-80 C. Though the maximum yield of BS was only 89 %, its concentration in extract was increased by 13 % compared to the extraction with hexane. Changing vials where the CO2 extract was collected, fractions with double and higher BS concentration could be obtained. The fractionation was simulated using a mathematical kinetic model of multicomponent extraction.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013110513041 - PDF
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Influence of Physicochemical Factors on Gushing Mechanism
Poštulková, Michaela ; Novák, Pavel ; Vitoušová, K. ; Brányik, T. ; Růžička, Marek
Gushing is a negative phenomenon when a foam spontaneously gush out when a bottle or can is opened. Despite a long-term research the gushing still has not been fully explained. The problem of gushing is its seasonal variability, depending on the raw materials and processing technology. In addition, gushing intensity may change over the years. Furthermore, gushing also related to the fact that there is no simple and inexpensive method for measuring. The aim of this work was to find a suitable gushing matrix which could be helpful to study gushing in a new experimental pressure equipment. Simple and inexpensive apparatus was built for the study of overfoaming beer. The valve system (placed on the pressure equipment) control outlet/inlet gas and liquid phase. The pressure and temperature sensors can be also connected to the equipment. It is also possible to regulate the rate of decrease gas pressure above the liquid - the sudden reduction ideally simulates the classic opening beer bottles. A model solution of gushing liquid was created and the influence of the temperature, pressure and pH on the intensity of gushing was measured.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013110513040 - PDF
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Upgrading of Biogas by Supported Liquid Membranes
Kárászová, Magda ; Vejražka, Jiří ; Veselý, Václav ; Izák, Pavel
The contribution investigate the basic characteristics of the supported ionic liquid membrane consisting of an ionic liquid [Emim] [Tf2N] and the porous support of polyvinylidenflouride. The membrane was performed during permeation into the carrier gas. The permeability of pure gases and mixtures of different composition were investigated. The obtained data were compared with the literature.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013102515210 - PDF
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