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Aerosol Nanoparticles Formed during Plasma Deposition
Ždímal, Vladimír ; Moravec, Pavel ; Doležal, B. ; Brožek, Vlastimil ; Neufuss, Karel
Results of pilot-plant experiments on a plasmatron WSPR constructed at the Institute of IPP AS CR are shown in this paper, dealing with plasma deposition of the ultrafine and fine aerosol fractions of some metallic materials. In this work we concentrated on its side-product investigating the ultrafine particles released during the process into the aerosol phase. The aerosol particle size distribution was studied in a near real time using the state-of-the-art aerosol spectrometers operated by the ICPF AS CR. It was verified that these instruments are able to take aerosol samples in the close vicinity of a high-temperature plasma and still provide sensible results. In the present work we discussed the possibility to produce aerosol nanoparticles of a defined composition and properties by the plasmatron technique.
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Application of Nanofibres in Filtration Processes
Kimmer, D. ; Vincent, I. ; Petras, D. ; Fenyk, J. ; Zatloukal, M. ; Sambaer, W. ; Slobodian, P. ; Salmela, H. ; Lehtimaki, M. ; Ždímal, Vladimír
The metod making possible to achieve the requireed of the nanofibres is demonstrated on the influence of telative humidity and solvent type on the fibre- forming process taking place in an electrostatic field. the effect of homogenity of the nanofibre deposition on the collection substrate is assessed empoying images from scanning electron microscopy (SEM) and tests of filtering abilities oh the nanofibre layers. Also, some measurements obtained when nanofibres were used in filtation of air, liquids and dispersions of carbon nanotubes in a liquid are presented.
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Nonequilibrium condensation processes in steam turbines in the light of new measurements of heterogeneous particles
Hrubý, Jan ; Kolovratník, M. ; Ždímal, Vladimír ; Bartoš, Ondřej ; Moravec, Pavel ; Jiříček, I.
In a steam turbine, droplets are formed either homogeneously or via heterogeneous nucleation on pre-existing heterogeneous particles. In a pioneering work, the present team developed a system to measure the number and size of heterogeneous particles down to diameter of 3 nm. This work reports on measurements at Power Plant Prunéřov II. For the first time, the data is at higher parameters (0.27 MPa, 250°C), and the diffusion battery was used to determine the size distribuition of the particles, showing count-mean diameter of about 13 nm.
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