Number of found documents: 476
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Dalekohledy typu Dall-Kirkham
Rail, Zdeněk; Ulrichová, Iva; Kuryshev, V.; Vápenka, David
2018 - Czech
Referát se zabývá optickými vadami dvojzrcadlových dalekohledů s elipsoidálními primárními a sférickými sekundárními zrcadly. Systém byl objeven na konci dvacátých let minulého století Horacem Dallem a Alanem Kirkhamem. Jeho optické prvky jsou snadno vyrobitelné a měřitelné. Tyto dalekohledy lze vybavit korektory a vytvořit z nich víceúčelové přístroje jak pro planetární pozorování, tak pro fotografování širokých zorných polí. Několik takových přístrojů bylo vyrobeno i v dílně Centra Toptec v Turnově. The paper deals with the optical aberrations of the two-mirror telescopes composed of the ellipsoidal primary and the spherical secondary mirrors. The system was discovered by Horace Dall and Alan Kirkham at the end of the Twenties of the 20th Century. Its optical elements are easy to manufacture and measure. These telescopes can be equipped by lens correctors and turned into multipurpose devices both for planetary observation and wide field photography. Several telescopes were manufactured in workshop of the Toptec Center in Turnov. Keywords: Two-mirror telescope; field corrector; optical aberrations; spherochromatic aberration; koma; astigmatism Available at various institutes of the ASCR
Dalekohledy typu Dall-Kirkham

Referát se zabývá optickými vadami dvojzrcadlových dalekohledů s elipsoidálními primárními a sférickými sekundárními zrcadly. Systém byl objeven na konci dvacátých let minulého století Horacem Dallem ...

Rail, Zdeněk; Ulrichová, Iva; Kuryshev, V.; Vápenka, David
Ústav fyziky plazmatu, 2018

The role of microstructure on wettability of plasma sprayed yttria stabilized zirconia coatings
Komarov, P.; Čelko, L.; Remešová, M.; Skorokhod, K.; Jech, D.; Klakurková, L.; Slámečka, K.; Mušálek, Radek
2018 - English
Atmospheric plasma spraying utilizing initial powder materials in micrometric size has been successfully used for various applications in different fields of the industry over the past several decades. Nowadays, the new trend in plasma spraying is to use sub-micron or nano-sized powder feedstocks in the form of colloidal suspension. This relatively new technology enables to obtain specific types of dense vertically cracked, fully dense or columnar microstructure. The aim of this work is to investigate the influence of coatings microstructure and topography on its water wetting properties. Two different microstructures, i.e. lamellar and columnar, were sprayed from chemically the same yttria-stabillized zirconia (YSZ) ceramics powders by the means of conventional atmospheric plasma spray and suspension hybrid water stabilized plasma spray techniques, respectively. Microstructural and phase composition of the initial powders and as-sprayed coatings were investigated using optical microscopy, scanning electron microscopy and X-ray diffraction techniques. Topography of coatings surface was measured by means of non-contact optical profilometry. The YSZ coatings wettability was evaluated based on water droplet contact angle using Sessile droplet method. The coatings microstructure reveals the important role in the change of droplet contact angle, where lamellar microstructure was found close to hydrophilic-hydrophobic transition and columnar microstructure was found superhydrophobic Keywords: Contact angle; Plasma spraying; Sessile drop method; Water; Yttria stabilized zirconia Available at various institutes of the ASCR
The role of microstructure on wettability of plasma sprayed yttria stabilized zirconia coatings

Atmospheric plasma spraying utilizing initial powder materials in micrometric size has been successfully used for various applications in different fields of the industry over the past several ...

Komarov, P.; Čelko, L.; Remešová, M.; Skorokhod, K.; Jech, D.; Klakurková, L.; Slámečka, K.; Mušálek, Radek
Ústav fyziky plazmatu, 2018

Combined coatings against mechanical wear and corrosion low carbon steel
Brožek, Vlastimil; Pokorný, P.; Kolísko, J.; Vokáč, M.; Mastný, L.; Stoulil, J.
2018 - English
In this study, special ceramic coatings were prepared on low carbon steel (1.0060 - EN 10027-2) via the plasma spraying technique using a WSP®-H plasma generator with output of up to 40 kg/h of aluminum oxide. Corundum coatings were deposited directly on the surface of steel plungers equipped with an anti-corrosion interlayer of zinc phosphate. Coating adhesion properties were tested using pin-off tests (modified ISO 4624) and reached a maximum value of 26 MPa. Corrosion resistance was evaluated by measurements of impedance spectra in the 100 kHz - 10 mHz range in a water solution of sodium sulfate. The capacity of electric double-layer varied depending on the porosity and thickness of the coating. Low-porosity coatings of >1.5 mm thickness had RCT 1.29·105 Ω·m2. The abrasive resistance of coatings was measured by rotary/machining test with SiC cutting knives, using a downforce of 50 kg·cm-2. Abrasion losses decreased with the quality of finish - starting at 0.00266 g cm-2 min-1 down to virtually zero losses after polishing the surface below Ra = 0.55 micro m. Keywords: Abrasion; Ceramic coatings; Corrosion resistance; Plasma spraying; Steel phosphating Available at various institutes of the ASCR
Combined coatings against mechanical wear and corrosion low carbon steel

In this study, special ceramic coatings were prepared on low carbon steel (1.0060 - EN 10027-2) via the plasma spraying technique using a WSP®-H plasma generator with output of up to 40 kg/h of ...

Brožek, Vlastimil; Pokorný, P.; Kolísko, J.; Vokáč, M.; Mastný, L.; Stoulil, J.
Ústav fyziky plazmatu, 2018

Suspension plasma spraying of sub-stoichiometric titania by hybrid water/argon stabilized plasma torch
Mušálek, Radek; Ctibor, Pavel; Medřický, Jan; Tesař, Tomáš; Kotlan, Jiří; Lukáč, František
2018 - English
In this study, suspension plasma spraying of sub-stoichiometric titania was attempted using hybrid water/argon stabilized plasma torch (WSP-H). Porous coatings with fine cauliflower-like columnar microstructure were successfully deposited in two separate experiments with different power levels of the plasma torch. In both cases, high solid-load content (40 wt. %) of the water-based suspension resulted in considerable coating thickness increase per deposition cycle. Coating annealing and partial remelting of the surface asperities were also achieved by additional pass of plasma torch in front of the coating surface. According to X-ray diffraction, all coatings consisted dominantly of rutile phase. Detailed microscopic observation of the as-sprayed and annealed deposits showed that the local coloration of the coating (ranging from dark blue to beige) was driven by the local overheating of the rough coating surface which could also promote the oxygen intake. Moreover, sample annealing was also observed to increase the sample reflectivity as observed by UV-VIS-NIR scanning spectrophotometry Keywords: Liquid feedstock; Plasma spraying; Suspension; Thermal spraying; Titania; WSP-H Available at various institutes of the ASCR
Suspension plasma spraying of sub-stoichiometric titania by hybrid water/argon stabilized plasma torch

In this study, suspension plasma spraying of sub-stoichiometric titania was attempted using hybrid water/argon stabilized plasma torch (WSP-H). Porous coatings with fine cauliflower-like columnar ...

Mušálek, Radek; Ctibor, Pavel; Medřický, Jan; Tesař, Tomáš; Kotlan, Jiří; Lukáč, František
Ústav fyziky plazmatu, 2018

Alternative Methods of Permeation Barriers Preparation
Veverka, Jakub; Matějíček, Jiří
2018 - English
Permeation barriers represent one of the crucial fields in materials development for thermonuclear fusion. Primary objective of the barriers is to suppress the permeation of hydrogen isotopes (mainly tritium) from future thermonuclear fusion facilities. Secondary objective is to reduce their retention in structural materials. Expected reactor conditions put high demands on the material, as well as on the final barrier quality. Key properties are tritium permeation reduction, absence of defects (especially cracks), high-temperature stability and corrossion resistance, and compatibility with structural materials (mostly ferritic-martensitic steels). Thin nitride layers, identified as promising permeation barriers, were prepared by diffusion-based nitridation and physical vapour deposition (PVD), and characterized. Keywords: Permeation barriers; Nitride layers; PVD coating; Permeation measurement Available at various institutes of the ASCR
Alternative Methods of Permeation Barriers Preparation

Permeation barriers represent one of the crucial fields in materials development for thermonuclear fusion. Primary objective of the barriers is to suppress the permeation of hydrogen isotopes (mainly ...

Veverka, Jakub; Matějíček, Jiří
Ústav fyziky plazmatu, 2018

Oprava objektivu 160/2500 turnovské hvězdárny
Rail, Zdeněk; Melich, Zbyněk; Šrajer, Bohdan; Šípová, Gabriela; Kaucká, Iva; Franců, Helena; Melich, Radek
2018 - Czech
Tento referát přináší informace o opravě achromatického objektivu o průměru 160 mm a ohniskové vzdálenosti 2500 mm, vyrobeného v 70. letech ve Vývojové optické dílně ČSAV v Turnově. Refraktor s tímto dubletem se stal hlavním přístrojem místní hvězdárny. Spojka tohoto objektivu obsahovala šlíry a bylo ji nutné vyrobit novou This paper brings the information about repair of the achromatic objective lens of diameter 160mm and focal length 2500mm produced by the Development Optical Workshop of the ČSAV in Turnov. The refractor with this dublet has become the main telescope of a local astronomical observatory. The positive lens contained impurities – schlieren and it was necessary to produce a new lens and change it. Keywords: Achromatic dublet; aplanat; grinding; polishing; autocollimation test; optical aberrations Available at various institutes of the ASCR
Oprava objektivu 160/2500 turnovské hvězdárny

Tento referát přináší informace o opravě achromatického objektivu o průměru 160 mm a ohniskové vzdálenosti 2500 mm, vyrobeného v 70. letech ve Vývojové optické dílně ČSAV v Turnově. Refraktor s tímto ...

Rail, Zdeněk; Melich, Zbyněk; Šrajer, Bohdan; Šípová, Gabriela; Kaucká, Iva; Franců, Helena; Melich, Radek
Ústav fyziky plazmatu, 2018

Tmelený objektiv Steinheilova typu
Rail, Zdeněk; Franců, Helena; Ulrichová, Iva; Šípová, Gabriela; Jareš, Daniel; Kuryshev, V.; Vápenka, David
2018 - Czech
Tento referát se zabývá achromatickými dublety se vstupním členem z flintového skla. Optické řešení těchto objektivů navrhl německý fyzik Carl August Steinheil v polovině 19. století. V nedávné minulosti bylo několik těchto dubletů vyrobeno pro astronomické účely v naší dílně. V referátu popisujeme výpočet a technologický postup výroby tmeleného Steinheilova objektivu s rovinnou výstupní plochou. This paper analyses the achromatic dublets with an entrance lens of the flint glass. The objective lens of this construction were devised by German physician Carl August Steinheil in the half of the 19 th century. Several pieces of these dublets were manufactured for astronomical purposes in our workshop in the past. We discuse the mathematical evaluation and the method of manufacture of the glued Steinheil objective with plane exit surface. Keywords: Achromatic objective; apochromatic objective; spherochromatic aberration; coma Available at various institutes of the ASCR
Tmelený objektiv Steinheilova typu

Tento referát se zabývá achromatickými dublety se vstupním členem z flintového skla. Optické řešení těchto objektivů navrhl německý fyzik Carl August Steinheil v polovině 19. století. V nedávné ...

Rail, Zdeněk; Franců, Helena; Ulrichová, Iva; Šípová, Gabriela; Jareš, Daniel; Kuryshev, V.; Vápenka, David
Ústav fyziky plazmatu, 2018

Mechanical properties of plasma sprayed layers of NiAl10 and NiAl40 on AZ91 alloy
Kubatík, Tomáš František; Brodil, R.; Ctibor, Pavel; Průša, F.; Brožek, Vlastimil
2018 - English
In this work, plasma coatings of NiAl10 and NiAl40 on magnesium alloy AZ91 substrate were prepared by the hybrid plasma spraying system WSP®-H 500. The both plasma sprayed coatings of NiAl10 and NiAl40 have metallurgical bond. The thicknesses of microstructures in the cross-section of NiAl10 and NiAl40 plasma sprayed coatings prepared by 9 passes were 374 and 440 μm respectively. Adhesion test of plasma sprayed layers was performed using a modified ASTM C 633 standard. The tensile adhesion strength values are 24.7 MPa for NiAl10 coatings and 12.3 MPa for NiAl40 coatings. Abrasion resistance according to Slurry Abrasion Response (SAR) test of NiAl40 layers had similar values (0.12 g/cm2)in a comparison with the uncoated AZ91 (0.126 g/cm2). Layers NiAl10 had greater weight losses (0.175 g/cm2) than uncoated AZ91. Microhardness of plasma coating of NiAl40 is several times greater than microhardnesses of plasma coating of NiAl10 and uncoated substrate AZ91 Keywords: Adhesion strength; Nickel alloys; Plasma spraying; Wear resistance Available at various institutes of the ASCR
Mechanical properties of plasma sprayed layers of NiAl10 and NiAl40 on AZ91 alloy

In this work, plasma coatings of NiAl10 and NiAl40 on magnesium alloy AZ91 substrate were prepared by the hybrid plasma spraying system WSP®-H 500. The both plasma sprayed coatings of NiAl10 and ...

Kubatík, Tomáš František; Brodil, R.; Ctibor, Pavel; Průša, F.; Brožek, Vlastimil
Ústav fyziky plazmatu, 2018

Application of Electric Probes for Study of Structure of Thermal Plasma Jet.
Hurba, Oleksiy; Hrabovský, Milan
2017 - English
Thermal plasma at atmospheric pressure was investigated. Electric probes and doable probe used as relatively simple and efficient tool for diagnostic of structure of flow field in thermal plasma jet. Were defined plasma potential and boundaries of the conducting region and their changing for the diferent operating modes of plasma torch. Keywords: Electric probes; double probe; thermal; plasma jet Available at various institutes of the ASCR
Application of Electric Probes for Study of Structure of Thermal Plasma Jet.

Thermal plasma at atmospheric pressure was investigated. Electric probes and doable probe used as relatively simple and efficient tool for diagnostic of structure of flow field in thermal plasma jet. ...

Hurba, Oleksiy; Hrabovský, Milan
Ústav fyziky plazmatu, 2017

Simulace zbytkových optických vad objektivu Merz 124/1477
Rail, Zdeněk; Melich, Zbyněk; Šrajer, Bohdan
2017 - Czech
Tento objektiv byl na Ústavu fyziky plazmatu,v.v.i., Centru Toptec v Turnově restaurován. Během tohoto procesu jsme získali možnost objektiv na optické lavici přeměřit a vyčíslit jeho zbytkové optické vady. Objektiv byl vyroben kolem roku 1860-1870. This objective lens was renoved in the Institute of Plasma Physics, v.v.i. Center Toptec in Turnov. During the process we got a possibility to measure the objective lens on the optical bench and to evaluate its residual optical aberrations. The objective lens was manufactured in 1860-1870 years Keywords: Achromatic dublet; spherochromatic aberration; coma; dispersion curve of glass; B-F chromatic correction Available at various institutes of the ASCR
Simulace zbytkových optických vad objektivu Merz 124/1477

Tento objektiv byl na Ústavu fyziky plazmatu,v.v.i., Centru Toptec v Turnově restaurován. Během tohoto procesu jsme získali možnost objektiv na optické lavici přeměřit a vyčíslit jeho zbytkové optické ...

Rail, Zdeněk; Melich, Zbyněk; Šrajer, Bohdan
Ústav fyziky plazmatu, 2017

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