No (543)
Yes (60)
Number of found documents:
603
Published from
to
The Technology of Manufacture of a Positive Lens of Achromatic Dublet
Rail, Zdeněk; Melich, Zbyněk; Šrajer, Bohdan; Šípová, Gabriela; Ulrichová, Iva; Franců, Helena; Melich, Radek; Vápenka, David; Tomka, David; Thoř, Tomáš
2020 - Czech
This paper deals with manufacturing of a positive lens of achromatic dublet. Diameter of the dublet is 158 mm and its focal length about 2500 mm. The glass material of the former lens was inhomogeneous and the dublet provided bad images. This is why we decided to manufacture new lens. The process was made by means of former machines of our workshop. The telescope with this dublet is placed at the Observatory of Turnov and serves for public astronomical observation. Tento referát popisuje technologický postup výroby spojky achromatického dubletu o průměru 158 mm a ohniskové vzdálenosti 2500 mm. Sklo, ze kterého byla vyrobena původní spojka, bylo nehomogenní a dublet špatně zobrazoval. Z tohoto důvodu jsme se rozhodli vyrobit novou spojku. Její výroba byla provedena na původních strojích naší dílny. Dublet je umístěn v dalekohledu na turnovské hvězdárně a slouží k veřejnému pozorování oblohy.
Keywords:
achromatic dublet; aplanat; coma; pherochromatic aberration
Available at various institutes of the ASCR
The Technology of Manufacture of a Positive Lens of Achromatic Dublet
This paper deals with manufacturing of a positive lens of achromatic dublet. Diameter of the dublet is 158 mm and its focal length about 2500 mm. The glass material of the former lens was ...
Residual Aberrations of the Gajdušek Objective Lens of Diameter 200 mm and Focal Length 3480 mm of the Observatory in Hradec Králové
Rail, Zdeněk; Melich, Zbyněk; Šrajer, Bohdan; Vápenka, David; Tomka, David; Thoř, Tomáš; Macner, David
2020 - Czech
The achromatic dublet of diameter 200 mm and focal length 3480 mm was manufactured by Professor ing. Vilém Gajdušek in Ostrava in 1954. The telescope with this objective is placed at the Observatory and planetarium in Hradec Králové. The objective was restored in the Institute of Plasma Physics, v.v.i.-Centrum Toptec in Turnov. During the process lens was measured and data were used for evaluation of its residual aberrations. We present the results of the measurement in this paper. Achromatický dublet o průměru 200 mm a ohniskové vzdálenosti 3480 mm byl vyroben profesorem ing. Vilémem Gajduškem v Ostravě v roce 1954. Dalekohled s tímto objektivem je umístěn na Hvězdárně a planetáriu v Hradci Králové. Objektiv byl v roce 2018 restaurován v Ústavu fyziky plazmatu, v.v.i.-Centru Toptec v Turnově. Čočky byly přeměřeny a z naměřených hodnot jsme vyčíslili jeho zbytkové optické vady. Výsledky simulace přinášíme v této práci.
Keywords:
achromatic dublet; aplanat; coma; pherochromatic aberration
Available at various institutes of the ASCR
Residual Aberrations of the Gajdušek Objective Lens of Diameter 200 mm and Focal Length 3480 mm of the Observatory in Hradec Králové
The achromatic dublet of diameter 200 mm and focal length 3480 mm was manufactured by Professor ing. Vilém Gajdušek in Ostrava in 1954. The telescope with this objective is placed at the Observatory ...
The Digitalisation of the Maksutov Camera 350/840 of the Observatory in Úpice
Rail, Zdeněk; Melich, Zbyněk
2019 - Czech
The Maksutov chamber with a diameter of 350 mm and a focal length of 840 mm was manufactured in Turnov in the early 1980s. At the Úpice Observatory it was used to photograph the sky for photographic film. Currently, we have been asked to convert it to a digital device. It was necessary to design and manufacture a correction element for the chamber to straighten its focal surface and to equip it with a suitable digital camera. In this work we present description of modification of this device. Maksutovova komora o průměru 350 mm a ohniskové vzdálenosti 840 mm byla vyrobena v Turnově počátkem 80. let. Na úpické observatoři sloužila k fotografování oblohy na fotografický film. V současné době jsme byli požádáni o jeji přestavbu na digitální přístroj. Pro komoru bylo nutné navrhnout a vyrobit korekční člen pro narovnání její ohniskové plochy a dále ji vybavit vhodným digitálním fotografickým přístrojem. V této práci přinášíme popis úpravy tohoto přístroje.
Keywords:
Maksutov chamber; focal surface
Available at various institutes of the ASCR
The Digitalisation of the Maksutov Camera 350/840 of the Observatory in Úpice
The Maksutov chamber with a diameter of 350 mm and a focal length of 840 mm was manufactured in Turnov in the early 1980s. At the Úpice Observatory it was used to photograph the sky for photographic ...
High temperature corrosion studies of HVOF sprayed coatings in molten sulphate salts environment
Lencová, K.; Česánek, Z.; Houdková, Š.; Lukáč, František; Mušálek, Radek
2019 - English
The generally applied requirements on lowering of emission production in the field of power industry have led, among others, into the application of low-emission combustion process of coal fired power plants. Besides the emissions reduction, this process has led to an increase of boilers parts corrosion degradation due to the reducing atmosphere in low-emission boilers, responsible for sulphide corrosion and molten salt attack. In such environment, the protection of the exposed surfaces gains importance. Among others, the thermal spraying technology can offer a suitable way of surface corrosion protection. In the present work, the high temperature corrosion behaviour of CoCrAlYTaCSi and Cr3C2-25%NiCr High Pressure/High Velocity Oxygen Fuel (HP/HVOF) sprayed coatings is evaluated and compared to the behaviour of bare structural steel (SPT360) substrate. The specimens were exposed to a molten salt environment, i. e., 12% Na2SO4 + 82% Fe2(SO4)3 at 690 °C under cyclic condition, simulating the working environment in low-emission boilers of coal-fired power plants. The thermogravimetric method was used to establish the kinetics of corrosion. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) techniques were used to analyse the corrosion products and determine the corrosion mechanism. The thermogravimetric measurement shows high oxidation rate of SPT360 steel. Cr3C2-25%NiCr coating provides slightly better performance compared to CoCrAlYTaCSi coating. Based on the obtained results, both coatings were found to have higher corrosion resistance than the SPT360 steel substrate, offering a sufficient surface protection in a given environment.
Keywords:
Coal fired boilers; CoCrAlYTaCSi; Cr3C2-25%NiCr; High temperature corrosion; hvof; Low-emission boilers; Thermal spraying
Fulltext is available at external website.
High temperature corrosion studies of HVOF sprayed coatings in molten sulphate salts environment
The generally applied requirements on lowering of emission production in the field of power industry have led, among others, into the application of low-emission combustion process of coal fired power ...
Suggested Changes After Prototype I Testing
Pintr, Pavel
2019 - Czech
Optical design description of rectangular spot of laser head. Our target was TOP HAT intensity distribution of rectangular spot for laser surfacing. Popis designu obdélníkového spotu laserové navařovací hlavice. Cílem bylo navrhnout TOP HAT obdélníkový spot vhodný pro laserové navařování.
Keywords:
laser welding; surfacing; infrared; rectantular spot; TOP HAT distribution
Available at various institutes of the ASCR
Suggested Changes After Prototype I Testing
Optical design description of rectangular spot of laser head. Our target was TOP HAT intensity distribution of rectangular spot for laser surfacing.
Technical solution for modernization of 2m telescope
Pintr, Pavel
2019 - Czech
Description of technical solution for renovation of 2 m telescope in Ondřejov. Popis technického řešení modernizace 2 m dalekohledu v Ondřejově.
Keywords:
2 m telescope; Ondřejov; astronomy; modernization
Available on request at various institutes of the ASCR
Technical solution for modernization of 2m telescope
Description of technical solution for renovation of 2 m telescope in Ondřejov.
Charting the development direction for optical path analysis
Pintr, Pavel
2019 - Czech
The research report includes lens selection for high-resolution stereoscopic imaging, glass defect overview, and viewing window market research. Výzkumná zpráva obsahuje výběr objektivů pro stereoskopické snímání ve vysokém rozlišení, přehled vad skel a průzkum trhu průhledového okénka.
Keywords:
stereoscopic imaging; glass; window
Available at various institutes of the ASCR
Charting the development direction for optical path analysis
The research report includes lens selection for high-resolution stereoscopic imaging, glass defect overview, and viewing window market research.
Several Optical Designs of Off-Axis systems
Rail, Zdeněk; Franců, Helena; Ulrichová, Iva; Šípová, Gabriela; Vápenka, David; Vávra, Emil
2019 - Czech
This paper introduces several types of optimized off-axis mirror systems. Systems without central shading and color defects provide high-contrast imaging. They are suitable for use as astronomical telescopes or as precision laboratory collimators of parallel light beams. Many of these devices have been designed and constructed for various purposes in the Development Optical Workshop of the Academy of Sciences of the Czech Republic. Tento referát seznamuje čtenáře s několika typy optimalizovaných mimoosových zrcadlových soustav. Soustavy bez centrálního stínění a barevné vady poskytují zobrazení\ns vysokým kontrastem obrazu. Jsou vhodné pro využití jako dalekohledy pro astronomická pozorování nebo jako přesné laboratorní kolimátory paralelních svazků světla. Řada těchto přístrojů byla navržena a zkonstruována pro nejrůznější účely ve Vývojové optické dílně AVČR, dnes ÚFP AV ČR v.v.i.- Centru Toptec v Turnově.Tato práce seznamuje čtenáře s několika z nich.
Keywords:
Off-axis optical system; astigmatism; spherochromatic aberration; coma; field curvature
Available at various institutes of the ASCR
Several Optical Designs of Off-Axis systems
This paper introduces several types of optimized off-axis mirror systems. Systems without central shading and color defects provide high-contrast imaging. They are suitable for use as astronomical ...
The Residual Optical Aberrations of the Merz Objective Lens 108/1620 mm
Rail, Zdeněk; Melich, Zbyněk; Vápenka, David; Šrajer, Bohdan
2019 - Czech
During the cleaning and adjustment of the Merz lens with a diameter of 108 mm and a focal length of 1620 mm, we had the opportunity to measure its optical parameters. From the measured values we made a calculation of residual optical defects of this achromatic lens. The results of these mathematical simulations are presented in this paper. The lens was made around 1923. Během čištění a seřizování Merzova objektivu o průměru 108 mm a ohniskové vzdálenosti 1620 mm jsme měli příležitost proměřit jeho optické parametry. Z naměřených hodnot jsme provedli výpočet zbytkových optických vad tohoto achromatického objektivu. Výsledky těchto matematických simulací přinášíme v tomto referátu. Objektiv byl vyroben okolo roku 1923.
Keywords:
Achromatic dublet; aplanat; spherochromatic aberration; coma
Available at various institutes of the ASCR
The Residual Optical Aberrations of the Merz Objective Lens 108/1620 mm
During the cleaning and adjustment of the Merz lens with a diameter of 108 mm and a focal length of 1620 mm, we had the opportunity to measure its optical parameters. From the measured values we made ...
Stability of an optical monitor for deposition of 42-layer interference bandpass filter 520-590 nm
Žídek, Karel
2018 - Czech
We report on stability of a deposition process of a complex system of thin layers. The layers were designed as a 42-layer bandpass interference filter. The layers of TiO2 and SiO2 were monitored both by the means of a crystal and an optical thickness monitor. We discuss the case when the design of the interference filter is continuously adapted according to the real thickness of the already deposited layers. V této zprávě popisujeme stabilitu depozice komplikovaných soustav tenkých vrstev, které byly navrženy jako interferenční filtr s pásmovou propustností. Jde o 42 vrstev TiO2 a SiO2, které jsou monitorovány jednak tzv. krystalovým a optickým monitorem tloušťky. Diskutujeme případ, kdy je návrh IF průběžně upravován podle reálné tloušťky deponovaných vrstev.
Keywords:
thin layer deposition; thickness monitor; interference filter; deposition stability
Available at various institutes of the ASCR
Stability of an optical monitor for deposition of 42-layer interference bandpass filter 520-590 nm
We report on stability of a deposition process of a complex system of thin layers. The layers were designed as a 42-layer bandpass interference filter. The layers of TiO2 and SiO2 were monitored both ...
NRGL provides central access to information on grey literature produced in the Czech Republic in the fields of science, research and education. You can find more information about grey literature and NRGL at service web
Send your suggestions and comments to nusl@techlib.cz
Provider
Other bases