No (399)
Yes (48)
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Black Chromia Plating for the Solar Radiation Absorbers
Brožek, Vlastimil; Březina, Václav; Brom, Petr; Kubatík, Tomáš František; Vilémová, Monika; Mastný, L.; Novák, M.
2016 - English
Black chromia layers were produced on copper, zirconium and aluminium substrates. These layers are aimed to serve as solar collectors. Efficiency of the layers during UV-VIS, UV radiation and WSP® plasma torch radiation is described. The chromia layers were prepared by a new procedure, i.e. deposition of ammonium dichromate solution using plasma torch or so called Liquid Precursor Plasma Spraying (LPPS). Solution of ammonium dichromate is fed into plasma stream, where dissociation takes place under temperatures of 4000 K – 25000 K. Up to nanometric oxide particles can be produced; the resulting size is dependent on solution concentration and feeding nozzle diameter. The particles impact on substrate and form coating. Using 2 wt.% to 5 wt.% solution of ammonium dichromate and feeding nozzle of 0.2 mm in diameter is the size of produced chromia particles about 6 µm which results in formation of 2 µm to 3 µm thick coating, i.e. according to the theory an optimal thickness 2.5 um for absorption layers, necessary condition for formation energy traps for IR radiation emitters up to 100°C. Moreover, black chromia coating is a suitable corrosion barrier of metallic substrates. \n\n
Keywords:
Solar collector; black chromia; plasma spraying; ceramic coatings
Available at various institutes of the ASCR
Black Chromia Plating for the Solar Radiation Absorbers
Black chromia layers were produced on copper, zirconium and aluminium substrates. These layers are aimed to serve as solar collectors. Efficiency of the layers during UV-VIS, UV radiation and WSP® ...
Black Chromia Coatings on Metal Tubes for the Solar Collectors
Brožek, V.; Mastný, L.; Novák, M.; Vilémová, Monika; Kubatík, Tomáš František
2016 - English
This paper describes the results of the first phase of the study preparation, structure and properties of coatings modification of black chromium oxide on copper, aluminium, iron and zirconium tubes for solar collectors. The coatings are prepared by plasma spraying of liquid chromate method which is known as liquid precursor plasma spraying. Coatings have the function of an energy trap for thermal radiation wavelengths of 1 μm – 3 μm i.e. in the IR region. At the same time, the coating increases the corrosion resistance of metal substrates. The nanometric structure and thickness of the coating depend of the feeding distance and the concentration of chromate precursors. For the deposition of nanometric splats of melt chromiumIII oxide, a new type of feeder that injects precursors into the water stabilized thermal plasma produced by the WSP® generator has been\ndeveloped.\n
Keywords:
Solar collector; black chromia; plasma spraying; suspension spraying
Available at various institutes of the ASCR
Black Chromia Coatings on Metal Tubes for the Solar Collectors
This paper describes the results of the first phase of the study preparation, structure and properties of coatings modification of black chromium oxide on copper, aluminium, iron and zirconium tubes ...
Spectroscopic Study of Underwater Electrical Discharge Generated by Nanosecond Pulses.
Pongrác, Branislav; Šimek, Milan; Babický, Václav; Člupek, Martin; Lukeš, Petr
2016 - English
Underwater electrical discharge generated by high voltage pulses with nanosecond duration (~110 kV amplitude on the needle, ~5 ns duration (FWHM), 1 Hz repetition rate) has been investigated. Time–resolved optical emission spectroscopy showed different emission spectra profile of the ns–pulsed discharge compared to the μs–pulsed discharges investigated previously. Some characteristic peaks typical for water discharges (Hα, OI) were clearly visible in the spectra. In addition, the integral light emission of the discharge was recorded by photomultiplier tube.
Keywords:
nanosecond discharge; water discharge; time-resolved emission spectroscopy
Available at various institutes of the ASCR
Spectroscopic Study of Underwater Electrical Discharge Generated by Nanosecond Pulses.
Underwater electrical discharge generated by high voltage pulses with nanosecond duration (~110 kV amplitude on the needle, ~5 ns duration (FWHM), 1 Hz repetition rate) has been investigated. ...
PROBA3 Coronograph System Progress Report
Horodyská, Petra; Melich, Radek
2016 - English
The scope of this document is to provide to CSL and ESTEC a progress report of ongoing activities as described in Project Management Plan v1_1. TOPTEC main activities cover realization of coronagraph optical elements, housing for this elements, HDD and the Lyot stop realization. In year 2016, the DM model was finished and delivered and the STM model was competely realized and delivered. Toptec started to prepare the documents for Critical Design Review (CDR).
Keywords:
coronagraph optical elements; housing; HDD; Lyot stop; DM; STM
Available on request at various institutes of the ASCR
PROBA3 Coronograph System Progress Report
The scope of this document is to provide to CSL and ESTEC a progress report of ongoing activities as described in Project Management Plan v1_1. TOPTEC main activities cover realization of coronagraph ...
METIST mirror M1 FS
Lédl, Vít; Melich, Radek; Vít, Tomáš
2016 - English
Scope of the document is to provide required test results with respect to the structure and optical performance of individual optical surfaces of M1 mirror, FS version. The mirror has a unique numbering M1-C20-23.
Keywords:
METIS mirror M1 FS
Available on request at various institutes of the ASCR
METIST mirror M1 FS
Scope of the document is to provide required test results with respect to the structure and optical performance of individual optical surfaces of M1 mirror, FS version. The mirror has a unique ...
Corrosion behavior of plasma coatings CuAl10 and CuAl50 on magnesium alloy AZ 91
Kubatík, Tomáš František; Stoulil, J.; Stehlíková, K.; Slepička, P.; Janata, Marek
2016 - English
The most common magnesium alloy AZ 91 is widely used as a structural material, but its use is limited at higher temperatures and high humidity. Plasma spraying is a technology that allows to prepare protective metallic and non-metallic coatings on a wide variety of substrates including magnesium and its alloys. In this study, CuAl10 and CuAl50 were plasma sprayed on magnesium alloy AZ 91 with the aim to study corrosion resistance of the plasma sprayed coatings. The corrosion resistance of layers was evaluated by the method of electrochemical potentiodynamic measurement as well as long-term corrosion tests in a condensation chamber with 0.5 mol\nNaCl at the temperature of 35 °C for 1344 hours. Layers with 1, 2, 5 passes and passes of CuAl10 with the thickness ranging from 75 to 716 mm and CuAl50 with the thickness ranging from 64 to 566 mm were prepared. The increased corrosion velocity was observed in the case of thin layers of 2 and 5 passes due to the development of a galvanic corrosion couple. The CuAl10 layer prepared with ten passes has an outstanding corrosion resistance.
Keywords:
magnesium alloy AZ 91; plasma spraying; corrosion resistance
Available at various institutes of the ASCR
Corrosion behavior of plasma coatings CuAl10 and CuAl50 on magnesium alloy AZ 91
The most common magnesium alloy AZ 91 is widely used as a structural material, but its use is limited at higher temperatures and high humidity. Plasma spraying is a technology that allows to prepare ...
Deposition of Titania from Solution by Hybrid Water-Stabilized Plasma Torch
Mušálek, Radek; Medřický, Jan; Tesař, Tomáš; Kotlan, Jiří; Lukáč, František
2016 - English
Thermal spraying with liquid feedstock presents a novel route for deposition of functional coatings. In this study, possibility of preparation of titania coatings from solution by hybrid water stabilized plasma torch is presented. Coatings were prepared from solution of titanium isopropoxide Ti[OCH(CH3)2]4 in anhydrous ethanol. Fragmentation of feedstock stream in the plasma jet was monitored by shadowgraphy. Deposition was carried out on steel samples mounted to the cooled rotating carousel. Cross-sectional images from SEM microscope showed successful formation of the deposit with dual morphology consisting of fine feather-like features combined with bigger droplets. X-ray diffraction revealed formation of nanometric rutile crystallites.
Keywords:
Thermal spraying; plasma spraying; titania; solution; liquid feedstock
Available at various institutes of the ASCR
Deposition of Titania from Solution by Hybrid Water-Stabilized Plasma Torch
Thermal spraying with liquid feedstock presents a novel route for deposition of functional coatings. In this study, possibility of preparation of titania coatings from solution by hybrid water ...
Formation of RONS in cold air plasma activazed water and their effects on cell membranes of Escherichia coli
Tarabová, B.; Machala, Z.; Doležalová, Eva; Lukeš, Petr
2016 - English
In this work, we focused on the detection of secondary reactive oxygen and nitrogen species (RONS) formed by cold plasma induced gas-liquid chemistry in air discharge activated water and liquids. Plasma induced chemical changes in plasma activated water (PAW) were correlated with the antibacterial effect, sublethal injury of bacterial cells and peroxidation of membrane lipids. The contribution of the electric field induced by the plasma treatment was evaluated by the detection of membrane permeabilization. The bactericidal effects of direct (plasma and PAW) and indirect (only PAW) treatments were compared with long-term preservation of the PAW with its antibacterial properties
Keywords:
cold air plasma; plasma activated water; sublethal injury; lipoperoxidation
Available at various institutes of the ASCR
Formation of RONS in cold air plasma activazed water and their effects on cell membranes of Escherichia coli
In this work, we focused on the detection of secondary reactive oxygen and nitrogen species (RONS) formed by cold plasma induced gas-liquid chemistry in air discharge activated water and liquids. ...
DYNAMICS OF ACCELERATING STREAMER IN BARRIER DISCHARGE IN AIR.
Hoder, T.; Bonaventura, Z.; Prukner, Václav; Šimek, Milan
2016 - English
An accelerating streamer in barrier discharge is generated in 10 torr pressure air. Using the complex voltage waveform, the stable and reproducible discharge is triggered. From the ratio of two spectral bands of molecular nitrogen the electric field is determined in 2D. These results are well resolved in time and space thus suitable as a benchmark for computation of the streamer initiated plasma-chemistry in air.
Keywords:
streamer; air; electric field
Available at various institutes of the ASCR
DYNAMICS OF ACCELERATING STREAMER IN BARRIER DISCHARGE IN AIR.
An accelerating streamer in barrier discharge is generated in 10 torr pressure air. Using the complex voltage waveform, the stable and reproducible discharge is triggered. From the ratio of two ...
METIS mirror M2 FS
Lédl, Vít; Melich, Radek; Vít, Tomáš
2016 - English
Scope of the document is to provide required test results with respect to the structure and optical performance of individual optical surfaces of M2 mirror FS version. The mirror has a unique numbering M2-C21-24.
Keywords:
METIS mirror M2 FS
Available on request at various institutes of the ASCR
METIS mirror M2 FS
Scope of the document is to provide required test results with respect to the structure and optical performance of individual optical surfaces of M2 mirror FS version. The mirror has a unique ...
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