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Optické a elektrické charakteristiky koplanárního povrchového bariérového výboje v dusíku
Šimek, Milan ; Homola, T.
We inspected basic electrical and optical characteristics of dielectric coplanar surface barrier discharge (DCSBD) driven by AC high voltage at atmospheric pressure in high purity nitrogen. Voltage and current traces together with intensity evolution of most important emissions were registered with high time resolution in the UV-vis-NIR spectral range and for various densities of micro-discharges generated on the DCSBD surface. It comes out that most intense emissions are produced by a) energetic electrons through direct electron impact excitation/ionisation of N2 molecule and b) N2(A) metastable species through N2(A)+ N2(A) energy pooling and N2(A)+NO resonant energy transfer processes.
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Účinnost generace ozónu v koplanárním povrchovém bariérovém výboji v syntetickém vzduchu
Šimek, Milan ; Homola, T.
Efficiency of ozone formation by Dielectric Coplanar Surface Barrier Discharge driven in atmospheric-pressure, dry synthetic air was examined in a wide range of applied energy densities (0.01-1 Wh/l). Applied energy density was controlled by combining appropriately dissipated discharge power with airflow rate (5 – 50 l min-1). The O3 concentration was monitored outside the discharge chamber by means of non-dispersive UV photometric O3 analyzer. From the ozone production concentration measurements, we evaluated ozone production and yield. The ozone concentration, production and yield reached 800ppm, 5 g/h and 40 g/kWh, respectively.
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ST2D - Software for Determination of Total Strains on a Surface
Vavřík, Daniel
The new optical method of the total strains zone shape and size identification on a surface named "Method of Deformed Circles" was developed in ITAM CAS. Method is based on the optical observations of deformations of hexagonal grid on the specimen surface. Related software ST2D on Windows platform can determine field of strains, stress and energy.
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Degradation of protective effect of surface layer on Ni3Al-Cr in hydrogen environment
Čermák, Jiří ; Rothová, Věra
Protective effect of surface layer on Cr-doped (4 and 8 at. % Cr) Ni3Al intermetallic was studied by high-temperature hydrogen permeation tests that were carried out at temperatures in the interval 775-1223 K. Hydrogen with about 1 vol. ppm O2 and 2 vol. ppm of H2O was used for the gas-permeation tests. It was observed that the addition of Cr degrades the - otherwise very good - high-temperature protective ability of oxide-containing surface layer of Ni3Al-Cr at strongly reducing hydrogen environment.
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Modification of transmissivity of hydrogen through the surface of Ni3Al by alloying
Čermák, Jiří ; Rothová, Věra
Hydrogen invasion into Ni3Al-M was studied by gas-permeation method in temperature range 573 - 1 223 K. The dependence of hydrogen permeation flux J(d) through the membrane-like samples on the samples thickness d enabled us to assess the influence of the surface upon the rate of permeation. The surface transmissivity was introduced as a quantitative characteristic describing the rate of the process. Influence of three modifying elements M = Fe, Cr and Zr was studied. It was found that Zr supports and, on the contrary, Cr eliminates the inhibiting effect of the surface. The iron did not alter significantly the hydrogen transmissivity, and it causes enhanced grain boundary brittleness in hydrogen environment.
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Analysis of abrasion of cotyles
Mandát, Dušan ; Nožka, Libor ; Hrabovský, Miroslav
The 3D optical scanning topography is one possible method of an analysis of the cotyle deformation. The object of this experiment is to quantify the decrease of cotyle material. The scanning object is polyethylene coxa cotyle ABG1.The cotyle is a plastic fossette surounded with metal cage, which is connected with a coxa of the patients. Due to use the deformation of the surface arise.
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