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Unique exposure system for the whole body inhalation experiments with small animals
Večeřa, Zbyněk ; Mikuška, Pavel ; Moravec, Pavel ; Smolík, Jiří
The especially inhalation chamber is constructed for chronic exposure studies of small animals to nanoparticles under strictly controlled conditions in frame of project „Study of transport of inhalated nano-sized particles (Pb, Cd) and their allocation in organs“. The inhalation chamber builds from a glass and stainless steel and makes possible long-term inhalation procedures (up to 60 days, 24 hours/day) with up to four discrete groups of mice population (up to 60 individuals each) or of rats population (up to 20 individuals each) under controlled illumination, temperature, relative humidity, doses (0.5 x 106 - 5 x 106 particles/cm3) and size (10-60 nm) of nano-sized particles which are synthesized via aerosol route in a hot wall tube flow reactor using metal organic precursors.
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Possible way to prepare nanoparticles from aerosols released at plasma deposition
Brožek, Vlastimil ; Mastný, L. ; Moravec, Pavel ; Ždímal, Vladimír
During plasma deposition of powdered metals or inorganic compounds using WSP® generator, they interact with the plasma having temperature between 25000 and 30000 K. As a result, they melt, evaporate, thermally decompose, get ionized and/or react chemically both with plasma-forming medium and with the surrounding atmosphere or carrier gas. An experimental apparatus was constructed enabling us to capture aerosol particles emitted from the surface of the free flying particles (FFP) heated in a stream of plasma. In this work we studied content, composition and size distribution of nanosized particles of Ag and oxides of Al, Ti, Cr and W, released during plasma deposition process. These particles were analyzed by dynamic light scattering - photon correlation spectroscopy using instrument MALVERN, and with aerosol spectrometers SMPS 3936 and APS 3321.Concentration of aerosols containing nanoparticles of silver or metal oxides with diameters below 100 nm was found to be in the range 85 to
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Size Dependence of Reactive Uptake Coefficient in Chemical Reactions on Aerosol Nanoparticles
Levdansky, Valerij Vladimirovič ; Smolík, Jiří ; Ždímal, Vladimír ; Moravec, Pavel
Chemical reactions in aerosol systems play a significant role in formation of new aerosol particles and their growth in the atmosphere and in various areas of nanotechnology. In the case of nanoscale aerosol particle the size effects can sufficiently affect the rate of chemical reactions both inside the particle and on its surface. The size dependence of a chemical reaction occurring on the nanoparticle surface can be related to the size dependence of the intrinsic activation energy for a chemical reaction and the adsorption kinetics of reactant molecules. Here we consider some aspects of the possible influence of the mentioned effects on the reactive uptake coefficient in the Eley-Rideal mechanism of a chemical reaction.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22012102615344 - PDF
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Mass Accomodation Coefficient for Nanoscale Aerosol Particles
Levdansky, Valerij Vladimirovič ; Smolík, Jiří ; Ždímal, Vladimír ; Moravec, Pavel
The influence of size effects on physicochemical transformations and transfer processes in the heterogeneous systems with nanoobjects attracts increasing attention of researchers. These problems are of interest for nanotechnology and atmospheric physics. Size effects can influence the cohesive energy as well as the activation energies of vacancy formation and diffusion of atoms in the nanoscale particles (Vanithakumari and Nanda, 2008). Phase transitions (including nucleation) in aerosol systems with nanoscale particles (clusters) also depend on the nanoparticle size (Levdansky et al., 2010). Hear we discuss the size dependence of the mass accommodation coefficient gama in the gas–nanoparticle system.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22012102615343 - PDF
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Nanoparticle Formation by Thermal Decomposition and Oxidation of Manganese(II) Acetylacetonate
Moravec, Pavel ; Smolík, Jiří ; Bakardjieva, Snejana ; Levdansky, V.V.
Over the last decade, Mn and MnOx nanoparticles has been extensively investigated due to their great importance in catalysis, electrochemistry, ion exchange materials, batteries and other areas (Si et al., 2005; Han et al., 2006). This work describes preliminary experiments producing manganese nanoparticles by metal organic chemical vapor deposition (MOCVD) using manganese(II) acetylacetonate (MnAA) as a precursor.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22012102615333 - PDF
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Implementation of CRM information system in a service oriented small and middle enterprise company
Němec, Vojtěch ; Švecová, Lenka (advisor) ; Moravec, Pavel (referee)
Diploma thesis reviews a topic of Customer Relationship Management information system implementation from a managerial point of view. Theoretical part describes strategies for a Customer Relationship Management in a field of a small and middle enterprise business. It contains a description of technological options and a market situation in information systems business. Author describes a topic of information systems and their value added and is focused on a process of implementing the Customer Relationship Management information system. In a practical part there is a specific implementation project being analyzed. The analysis is based on the feedback of customers of a company and users of a new system. This part describes a specific implementation project, highlights possible failures and finds possible options to avoid them.
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Processes of Nanoparticle Formation in Low Temperature Plasma
Brožek, V. ; Mastný, L. ; Moravec, Pavel ; Neufuss, Karel ; Ondráček, Jakub ; Ždímal, Vladimír
This work describes the synthesis of nanoparticles during interaction of several different metals (Ag) or their respective oxides (TiO2, Cr2O3) with oxygen-hydrogen plasma having temperatures above 25000 K. Resulting nanoparticles and/or their aggregates in the size range of 25-300 nm were deposited on metallic targets and/or trapped in the water filters and separated using ultra-centrifugal apparatus. The aerosol spectrometer SMPS 3936 (scanning mobility particle sizer) was used to study the particle size distribution of generated nanoparticles in the size range 14 – 700 nm. In order to extend the measured particle size range towards larger sizes, the APS 3321 spectrometer (aerodynamic particle sizer) with the size range 500-20000 nm was used simultaneously. Both spectrometers were set-up to sample with three minute time resolution. Process conditions and production of inorganic nanoparticles of defined composition are discussed in this work.
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Generation of Binary COOx/SiO2 Nanoparticles from Organocompound Precursors
Moravec, Pavel ; Smolík, Jiří ; Bakardjieva, Snejana ; Levdansky, V.V.
In recent years cobalt and cobalt oxide nanoparticles have attracted substantial research effort because of their potential applications such as protective materials, catalysts, magnetic data recorders, batteries and gas sensors (Jang et al., 2004). To improve their functionality and biocompatibility nanoparticles are frequently coated with SiO2 (Teleki et al., 2008). In this work, we studied CoOx-SiO2 binary nanoparticles synthesis by metal organics chemical vapor deposition (MOCVD) using organo-compound precursors cobalt acetylacetonate (CoAA) and tetraethyl orthosilicate (TEOS).
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