Surface protection of components in nuclear and conventional power plants

Technologie žárového nástřiku zajišťují ochranu povrchu součástí proti působení okolního prostředí i umožňují renovovat povrchy již opotřebené. jejich využití v oblasti jaderných a klasických elektráren, a to v rámci řešení projektu Národní centrum pro energetiku. Výzkum byl zaměřen na vývoj a testování funkčních vlastností vhodných materiálů povlaků a technologií nástřiku pro konkrétní aplikace. Pozornost byla zaměřena zejména na vývoj ochrany a renovaci povrchu kotlových těles a na preventivní nástřik kořenové oblasti heterogenních svarů. Pro nástřik nedemontovatelných částí kotlových těles byla zvolena mobilní technologie nástřiku elektrickým obloukem, pro nástřik vnitřního průměru kořene heterogenního svaru moderní technologie nástřiku za studena. Vyvinutý a optimalizovaný postup žárového nástřiku a různé materiálové kombinace byly ověřeny nástřikem reálných komponent.Prezentované výsledky byly získány v průběhu řešení projektu TA ČR TN01000007 Národní centrum pro energetiku.hermal spraying technologies make it possible to protect the surface of components against environmental influences and to renovate already worn surfaces. The potential of their use in the field of nuclear and conventional power plants was mapped within the solution of the National Centre for Energy project. The research was focused on the development and testing of functional properties of suitable coating materials and spraying technologies for specific applications. Attention was focused mainly on the development of protection and renovation of the surface of boiler bodies and on the preventive spraying of the root area of heterogeneous welds. The mobile technology of electric arc spraying was chosen for the spraying of non-dismantled parts of boiler bodies, while the modern technology of cold spraying was identified as suitable for the spraying of the inner diameter of the root of the heterogeneous welds. The developed spraying processes and material combinations were verified by spraying real components

COMPARISON OF Mo COATING DEPOSITED BY TWAS AND APS SinplexPro THERMAL SPRAY TECHNIQUES

The wear resistant Mo coatings were deposited using SmartArc Electric Arc Wire Spray System and advanced SinplexPro high throughput atmospheric plasma spray gun. The coatings were analyzed in terms of microstructure, mechanical properties and tribological characteristics, including wear rate and wear mechanism. It was shown that despite of the differences in deposition process principles, the properties of the coatings don’t differ with respect to their functional properties. Both coatings reached comparable hardness, microhardness, wear resistance and coefficient of friction. The economic aspects remain the main argument for the recommendation of the most suitable thermal spray deposition technique for the application of molybdenum coatings

LOCAL MECHANICAL PROPERTIES OF ATMOSPHERIC SPRAYED MOLYBDENUM COATINGS DEPOSITED WITH CASCADED PLASMA TORCH

Increasing interest for industrial use of thermally sprayed coatings leads to development in most thermal spraying technologies, including atmospheric plasma spraying (APS). The latest cascaded torch SinplexPro from Oerlikon Metco incorporates the efficiency advantages of cascaded arc technology into a single-cathode spray gun. It leads to more stable plasma arc across a wide range of gas flows, mixtures and pressures and also highly increases powder throughput. Thermal sprayed molybdenum coatings are widely used for improving wear resistance and sliding properties in many mechanical applications. Results of pure molybdenum coatings sprayed with cascaded plasma torch are not yet fully investigated. In this paper, mechanical properties of atmospheric plasma sprayed molybdenum coatings on steel (S235) substrate are evaluated. Optimization of spraying parameters for spherical Mo powder sprayed by cascaded plasma torch SinplexPro is carried out and the influence on final microstructure, mechanical and tribological properties of molybdenum coatings is analysed

Study of CeO2-PrO2-Y2O3 ceramic pigments

The synthesis of new colourants based on CeO2 hasa benn investigated, the focus of which was the preparation of pigments for colouring ceramic glazes. The synthesis of these colourants involved high-temperature calcination of starting oxides, and the optimum conditions for their synthesis were determined. The pigments were evaluated from the standpoint of their structure, hue and ability to colour seramic glazes

Consequences of EU directive "Television without frontiers" on Czech terrestrial television programmes

The dissertation Consequences of EU Directive "Television without Frontiers" on Czech terrestrial television programmes deals with the implementation into Czech audiovisual law of EU Directive "Television without frontiers" in 2001. Specifically this study deals with one controversial aspect its implementation, namely the obligation imposed by the Directive on domestic television stations to grant the majority of their broadcasting time to programmes produced in the European Union. This study focuses on whether there have been significant changes in the program structure of Czech television - changes in where programmes originate from, changes in terms of the percentage of European and non-European programmes and the types of programmes broadcast

Transformation of Second Homes in The Kokořínsko Protected Landscape Area

The main content of this Thesis is the second home as a part of tourism and recreation - very popular form for leisure time. The aim of the Diploma Thesis is to monitor changes in the second home in a protected landscape area Kokořínsko. The comparison of the second home in Sudetenland and in the Protectorate of Bohemia and Moravia is emphasised. Although this district did not belong to the important areas of the second home from the very beginning, after the Second World War Kokořínsko became more developed, mainly in the terms of cottage building. The Thesis is divided into several parts. Individual parts are important for understanding the second home in this district. The Thesis deals with a brief history of the second home in Kokořínsko and characterises the Sudetenland with the whole area from the point of view of development and localization. Concerning research methods, the Thesis uses mainly a field research method, a questionnaire survey and a statistic data research. Key words: a second home, protected landscape area Kokořínsko, folk architecture, Sudetenlan

Consequences of EU directive "Television without frontiers" on Czech terrestrial television programmes

The dissertation Consequences of EU Directive "Television without Frontiers" on Czech terrestrial television programmes deals with the implementation into Czech audiovisual law of EU Directive "Television without frontiers" in 2001. Specifically this study deals with one controversial aspect its implementation, namely the obligation imposed by the Directive on domestic television stations to grant the majority of their broadcasting time to programmes produced in the European Union. This study focuses on whether there have been significant changes in the program structure of Czech television - changes in where programmes originate from, changes in terms of the percentage of European and non-European programmes and the types of programmes broadcast

Colourful World of Pigments

Výzkum anorganických pigmentů v současné době prochází intenzivním rozvojem na všech světových výzkumných pracovištích. Stále častěji se tak objevují sloučeniny, které ještě před deseti lety byly označovány jako neperspektivní a ekonomicky neakceptovatelné, ovšem hygienicko-ekologický tlak zužující stávající sortiment pigmentů dokázal nasměrovat výzkum pigmentů ke sloučeninám se zajímavým složením, ve kterém se stále častěji objevují právě prvky vzácných zemín. Dosud získané informace dokazují, že tato cesta je nadějná, neboť nově připravené sloučeniny jsou svým složením ekologicky přijatelné, mají odpovídající pigmentové vlastnosti a jsou barevně zajímavé.Research on organic pigments currently undergoing intensive development at all world research institutions. Increasingly, compounds that ten years ago were established as unpromising and economically unacceptable, but hygienic and ecological pressure narrowing the existing range of pigments able to direct research pigments in compounds with interesting composition, which are increasingly containing rare earth elements. So far, the received information show that this way is promising because the newly prepared compounds are environmentally acceptable in its composition, has a corresponding pigment properties and are color interesting