Ano (60)
Počet nalezených dokumentů:
60
Publikováno od
do
Properties of hydroxyapatite surface deposited by plasma spray technologies
Matějková, M.; Čížek, Jan; Mušálek, Radek; Dlouhý, I.
2017 - anglický
The surface properties of hydroxyapatite (HA) deposited on the Ti-6Al-4V substrates by plasma spraying were studied. Two different plasma spray technologies (hybrid plasma spray system (WSP-H) and conventional atmospheric plasma spray technology (APS)) and two various feedstock (suspension for WSP-H and powder for APS) were used for deposition of HA layers potentially suitable for bio-applications. The layers properties (thickness, chemical and phase composition) and coating-substrate interface quality were analyzed. The XRD analysis showed formation of small amount of new phases (TTCP and CaO) in layers deposited by WSP-H. Better coating-substrate interface quality of samples prepared by WSP-H was observed. The results showed the deposition of HA through liquid feedstock via WSP-H as a promising route, complementing the traditional APS powder deposition in the near future.
Klíčová slova:
hydroxyapatite; hybrid water-stabilized plasma spray; atmospheric plasma spray technology
Dokument je dostupný na externích webových stránkách.
Properties of hydroxyapatite surface deposited by plasma spray technologies
The surface properties of hydroxyapatite (HA) deposited on the Ti-6Al-4V substrates by plasma spraying were studied. Two different plasma spray technologies (hybrid plasma spray system (WSP-H) and ...
RE beam generation in MGI disruptions on COMPASS.
Ficker, Ondřej; Mlynář, Jan; Macúšová, Eva; Vlainić, M.; Weinzettl, Vladimír; Urban, Jakub; Čeřovský, Jaroslav; Farník, Michal; Markovič, Tomáš; Papřok, Richard; Vondráček, Petr; Imríšek, Martin; Tomeš, Matěj; Havlíček, Josef; Varju, Jozef; Varavin, Mykyta; Bogár, Ondrej; Havránek, Aleš; Gospodarczyk, M.; Rabinski, M.; Jakubowski, M.; Malinovski, K.; Zebrowski, J.; Plyusnin, V.; Papp, G.; Pánek, Radomír; Hron, Martin
2017 - anglický
In the experiments with the massive gas injection (MGI) triggered disruptions in the COMPASS tokamak, post-disruptive runaway electron (RE) beams are generated occasionally. In this contribution, a relatively large set of discharges from the recent years is analysed in order to improve our understanding of the processes behind the beam generation. It seems that despite the low toroidal field applied in the discharges (typically 1.15 T) the magnetic perturbations may be small enough to allow the acceleration and confinement of the electrons. The influence of the different components and different sections of the frequency spectrum of the magnetic perturbations on the beam generation and RE beam current is examined. Fast visible camera images are also analysed. The relevance of COMPASS runaway electron experiments for large machines is discussed. Moreover, the potential of less common diagnostic tools (Cherenkov detector, vertical ECE, ...) to clarify the role of the pre-disruption fast electron population and the influence of prompt runaway electron losses in the current quench is discussed using the recent test measurements.
Klíčová slova:
RE; massive gas injection (MGI); disruptions; HXR; ECE; fast cameras
Dokument je dostupný na externích webových stránkách.
RE beam generation in MGI disruptions on COMPASS.
In the experiments with the massive gas injection (MGI) triggered disruptions in the COMPASS tokamak, post-disruptive runaway electron (RE) beams are generated occasionally. In this contribution, a ...
Microwave reflectometry for density profile and turbulence measurements on the COMPASS tokamak.
Bogár, Ondrej; Bílková, Petra; Böhm, Petr; Hron, Martin; Pánek, Radomír; Silva, A.; Zajac, Jaromír; Varavin, Mykyta
2017 - anglický
Microwave reflectometry is an established radar technique to acquire various scientific results in plasma fusion research. Fast electron density profile measurements are crucial for the study of fusion plasmas and the operation of fusion devices. Operation capability and first results of the reflectometry on the COMPASS tokamak are presented in this contribution.
Klíčová slova:
plasma; tokamak; COMPASS
Dokument je dostupný na externích webových stránkách.
Microwave reflectometry for density profile and turbulence measurements on the COMPASS tokamak.
Microwave reflectometry is an established radar technique to acquire various scientific results in plasma fusion research. Fast electron density profile measurements are crucial for the study of ...
Konstrukce spektroskopu pro pozorování hvězdných spekter
Rail, Zdeněk; Jareš, Daniel; Pintr, Pavel; Vápenka, David
2015 - český
Tento článek předkládá návod na konstrukci přístroje - spektroskopu pro vizuální pozorování hvězdných spekter. K jeho stavbě je použito běžně prodávaných součástek. Samotné sestavení přístroje lze provést bez pomoci obráběcích strojů ve spartánsky vybavené dílně. This paper presents the construction list of a spectroscope for visual observation of stellar spectra. The device consists of parts easily accessible on market. Assembly of the spectroscope does not require exceptionally equipped workshop and can be made in very spartan conditions.
Klíčová slova:
Spectrograph; Star spectral line; Newton telescope; Barlow lens; Difraction grating; Colimator lens; Toroidal lens; StarAnalyzer grating
Dokument je dostupný na externích webových stránkách.
Konstrukce spektroskopu pro pozorování hvězdných spekter
Tento článek předkládá návod na konstrukci přístroje - spektroskopu pro vizuální pozorování hvězdných spekter. K jeho stavbě je použito běžně prodávaných součástek. Samotné sestavení přístroje lze ...
Synthesis and applications of Intermetallics
Novák, P.; Salvetr, P.; Kříž, J.; Kubatík, Tomáš František
2015 - anglický
Intermetallic compounds, intermetallics, are characterized by interesting properties, such as e.g. excellent high -temperature oxidation resistance, shape memory or ability to store hydrogen reversibly. Their positive, but also negative, properties are a combination of the behaviour of metals and ceramics. Their wider application in industry is limited due to low room-temperature ductility and problematic production, associated with high melting points of many intermetallics, high reactivity of metals at high temperatures and problematic processing. In this paper, the overview of the methods for synthesis of intermetallic compounds is presented, ranging from conventional casting processes to modern powder metallurgy technologies. Selected interesting applications from industry and medicine, where their unique properties are used
Klíčová slova:
Intermetallic compounds; powder metallurgy technologies
Dokument je dostupný na externích webových stránkách.
Synthesis and applications of Intermetallics
Intermetallic compounds, intermetallics, are characterized by interesting properties, such as e.g. excellent high -temperature oxidation resistance, shape memory or ability to store hydrogen ...
Chemical aspects of antiballistic cermets preparation
Brožek, Vlastimil; Kubatík, Tomáš František; Chráska, Tomáš; Mušálek, Radek; Janata, Marek; Mastný, L.
2015 - anglický
The paper aims to demonstrate the possibilities of metal-ceramic material deposition on different types of metal or ceramic substrates using plasma deposition. A number of self-supporting components and the preparation of metal-braced composites are described and the results of plasma depositions of two particular extremely hard ceramic materials, boride and nitride of titanium are presented. The plasma deposition of these material is performed in technological conditions which prevent undesirable high-temperature oxidation. The paper describes deposition conditions that may lead to materials suited to create anti-ballistic protection and complicated shapes or improve parameters of surface layers of present anti-ballistic ceramics.
Klíčová slova:
Anti-ballistic ceramics; armour ceramics; plasma spraying; titanium boride; plasma spraying; titanium nitride
Dokument je dostupný na externích webových stránkách.
Chemical aspects of antiballistic cermets preparation
The paper aims to demonstrate the possibilities of metal-ceramic material deposition on different types of metal or ceramic substrates using plasma deposition. A number of self-supporting components ...
Mechanical and chemical properties of plasma sprayed bronze CuAl10 coating on magnesium and magnesium alloy AZ91
Kubatík, Tomáš František; Vilémová, Monika; Mušálek, Radek; Janata, Marek
2015 - anglický
The most common magnesium alloy AZ91 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 nonmetallic coatings on a wide variety of substrates including magnesium and its alloys. In this study, CuAl10 was plasma sprayed on magnesium and magnesium alloy AZ91 with the aim to study corrosion resistance of the magnesium substrates. The work focuses on optimization of the plasma spraying process, on chemical composition of the coatings, on interface between the coating and substrate, as well as on adhesive strength of the coatings. The coating were deposited after two passes of the spraying torch resulting in thickness of 150 micro m on magnesium substrate and 110 micro m on AZ91 substrate. Chemical microanalysis showed that deposition of CuAl10 alloy on magnesium results in formation of an intermetallic layer at the interface. The layer provides a
Klíčová slova:
Magnesium alloy AZ91; Plasma spraying
Dokument je dostupný na externích webových stránkách.
Mechanical and chemical properties of plasma sprayed bronze CuAl10 coating on magnesium and magnesium alloy AZ91
The most common magnesium alloy AZ91 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 ...
Structural and Mechanical Characterization of Spark Plasma Sintered Tungsten
Čech, J.; Haušild, P.; Kocmanová, Lenka; Matějíček, Jiří
2015 - anglický
The main objective of this paper is to describe the microstructure and mechanical properties of spark plasma sintered tungsten. The indentation tests, which are very advantageous because of their semi-nondestructive character and low requirements on the volume of investigated material, were carried out using Berkovich and spherical indenters. Indentation techniques with spherical indenters are less frequently used than those with sharp indenters but they offer variation of strain with the indentation depth and, therefore, they could be used for determination of stress-strain curves. Local stress-strain behavior obtained by this method showed good correspondence with the results of compression tests. Observation of the microstructure and the fracture surfaces helped to explain some phenomena which occurred during the mechanical testing
Klíčová slova:
tungsten; SPS; instrumented indentation
Dokument je dostupný na externích webových stránkách.
Structural and Mechanical Characterization of Spark Plasma Sintered Tungsten
The main objective of this paper is to describe the microstructure and mechanical properties of spark plasma sintered tungsten. The indentation tests, which are very advantageous because of their ...
Optické parametry objektivu Secrétan Paris 130/1930 Hvězdárny v Úpici.
Rail, Zdeněk; Melich, Zbyněk
2015 - český
Objektiv Secrétan Paris 130/1930 Hvězdárny v Úpici byl na pracovišti ÚFP AV ČR, v.v.i.- TOPTEC vyčištěn a byly proměřeny jeho optické parametry. V referátu uvádíme výsledky matematické simulace zbytkových vad objektivu. The Optical Parameters of Objective Lens Secrétan Paris 130/1930 of Observatory of Úpice Objective lens of Secrétan Paris 130/1930 of Úpice observatory was cleaned a measured its optical parameters in IPP AS CR, v.v.i. - TOPTEC. In this paper we present results of mathematical simulation of residual aberrations of this lens.
Klíčová slova:
Achromatic doublet; Antonín Bečvář; Chromatic aberration; Lens parameters; Residual optical aberrations; B-F type of chromatic correction; Uncorrected coma
Dokument je dostupný na externích webových stránkách.
Optické parametry objektivu Secrétan Paris 130/1930 Hvězdárny v Úpici.
Objektiv Secrétan Paris 130/1930 Hvězdárny v Úpici byl na pracovišti ÚFP AV ČR, v.v.i.- TOPTEC vyčištěn a byly proměřeny jeho optické parametry. V referátu uvádíme výsledky matematické simulace ...
Unfolding of energies of fusion products measured by the activation probe at JET
Ficker, Ondřej; Mlynář, Jan; Bonheure, G.; Murari, A.; Popovichev, S.
2015 - anglický
Providing a detection method for diagnostic of charged fusion products in tokamaks presents a major challenge, while its absolute calibration with a sufficient accuracy and its capability to withstand harsh fusion reactor environment will be required. A novel type of detector that meets most of these requirements, based on an activation probe, was tested in JET and other European facilities. This probe proved to be extremely robust due to its simple construction. It is equipped with samples of well defined isotopic abundance. The amounts of activated nuclei due to the reactions in these materials could be measured via ultra-low-level gamma spectroscopy. The feasibility of the proton spectrum reconstruction from measured activities is examined in this contribution with the help of the algorithm based on the Tikhonov regularisation constrained by minimum Fisher information. The reliability of the method was previously illustrated using synthetic proton data.
Klíčová slova:
fusion products; nuclear activation; protons; spectra
Dokument je dostupný na externích webových stránkách.
Unfolding of energies of fusion products measured by the activation probe at JET
Providing a detection method for diagnostic of charged fusion products in tokamaks presents a major challenge, while its absolute calibration with a sufficient accuracy and its capability to withstand ...
NUŠL poskytuje centrální přístup k informacím o šedé literatuře vznikající v ČR v oblastech vědy, výzkumu a vzdělávání. Více informací o šedé literatuře a NUŠL najdete na webu služby.
Vaše náměty a připomínky posílejte na email nusl@techlib.cz
Provozovatel
Zahraniční báze