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Relationship between Luminosity, Irradiance and Temperature of star on the orbital parameters of exoplanets
Pintr, Pavel
2012 - English
For 759 exoplanets detected by radial velocities method we found that distances of exoplanets from central star comply in general Schmidt law and these distances depend on the stellar surface temperature. Every stellar spectral class has a little different distribution. The Luminosity and the Irradiance has not effect on the distribution of distances of exoplanets. We have found the new formulas for calculation of effective temperature of exoplanets for spectral classes F, G, and K. These new formulas we can use for future calculation of habitable planets
Keywords:
luminosity; irradiance and temperature of star
Available at various institutes of the ASCR
Relationship between Luminosity, Irradiance and Temperature of star on the orbital parameters of exoplanets
For 759 exoplanets detected by radial velocities method we found that distances of exoplanets from central star comply in general Schmidt law and these distances depend on the stellar surface ...
Using FEM technology for optical surfaces polishing
Procháska, František; Polák, Jaroslav; Tomka, David; Šubert, E.
2012 - English
The aim of this article is optical surfaces polishing on the 6-axis computer-controlled (CCM) machine Optotech MCP 250 CNC using FEM technology, which is suitable for aspheric elements polishing. The main attention is dedicated to the choice and to the precise adjustment of major process parameters. The possibility of usage the multi wave interferometer Luphoscan as a data source for the2D surface correction is solved too.
Keywords:
asphere polishing; CCM polishing; asphere measurement
Available at various institutes of the ASCR
Using FEM technology for optical surfaces polishing
The aim of this article is optical surfaces polishing on the 6-axis computer-controlled (CCM) machine Optotech MCP 250 CNC using FEM technology, which is suitable for aspheric elements polishing. The ...
Digital Holographic Method for Piezoelectric Transformers Vibration Analysis
Psota, Pavel; Kopecký, V.; Lédl, Vít; Doleček, Roman
2012 - English
The paper describes a holographic method for vibration analysis in nanometer range. The method was successfully applied on different types of piezoelectric transformers and the measurement results are introduced. To proof the reliability of the method it was done a comparing simultaneous measurement of a piezoelectric component by the holographic method and the well-established single-point interferometric method. Results showing the minimal deviation of both methods are presented in the final part of the paper.
Keywords:
Digital holography; vibration analysis; piezoelectric transformers
Available at various institutes of the ASCR
Digital Holographic Method for Piezoelectric Transformers Vibration Analysis
The paper describes a holographic method for vibration analysis in nanometer range. The method was successfully applied on different types of piezoelectric transformers and the measurement results are ...
Surface states in photonic crystals
Vojtíšek, Petr; Richter, I.
2012 - English
Among many unusual and interesting physical properties of photonic crystals (PhC), in recent years, the propagation of surface electromagnetic waves along dielectric PhC boundaries have attracted considerable attention, also in connection to their possible applications. Such surfaces states, produced with the help of specialized defects on PhC boundaries, similarly to surfaces plasmons, are localized surfaces waves and, as such, can be used in various sensing applications. In this contribution, we present our recent studies on numerical modelling of surface states (SS) for all three cases of PhC dimensionality. Simulations of these states were carried out by the use of plane wave expansion (PWE) method via the MIT MPB package.
Keywords:
surface staes; PhC; MPB; PWE
Available at various institutes of the ASCR
Surface states in photonic crystals
Among many unusual and interesting physical properties of photonic crystals (PhC), in recent years, the propagation of surface electromagnetic waves along dielectric PhC boundaries have attracted ...
Status of Development of High Temperature Radiation Hardened Hall Sensors for Energy Producing Fusion Devices
Kovařík, Karel; Ďuran, Ivan; Sentkerestiová, J.; Oszwaldowski, M.; Viererbl, L.; Boshakova, I.; Holyaka, R.; Erashok, V.
2012 - English
A principally new diagnostic method has to be developed to allow the magnetic measurements in true steady state regime of operation of future fusion reactors. One of the options is use of diagnostics based on Hall sensors that are well established in experimental physics and industry. There are two main issues associated with the use of Hall sensors in harsh environment of future fusion reactors. They are low survival temperature of available commercial transducers and unreliability of these mostly semiconductor sensors under neutron irradiation. This paper describes status of development of sensors to be operational in conditions mentioned above.
Keywords:
Hall sensor; fusion; tokamak
Available on request at various institutes of the ASCR
Status of Development of High Temperature Radiation Hardened Hall Sensors for Energy Producing Fusion Devices
A principally new diagnostic method has to be developed to allow the magnetic measurements in true steady state regime of operation of future fusion reactors. One of the options is use of ...
Effect of plasma jet treatment on Escherichia coli
Doležalová, Eva; Verzichová, P.; Janda, V.; Člupek, Martin; Lukeš, Petr
2012 - English
A plasma jet treated solution of E. coli was studied in dependence of inactivation mechanism. A comparison of the conventional culture-based technique of counting CFUs and bacterial LIVE/DEAD staining was determined. Furthermore, we monitored a production of MDA.
Keywords:
plasma jet; bacteria; water treatment; sterilization
Available at various institutes of the ASCR
Effect of plasma jet treatment on Escherichia coli
A plasma jet treated solution of E. coli was studied in dependence of inactivation mechanism. A comparison of the conventional culture-based technique of counting CFUs and bacterial LIVE/DEAD staining ...
Optimization of electrode geometry and piezoelectric layer thickness of a deformable mirror
Kruchenko, Alexey; Nováková, Kateřina; Mokrý, Pavel
2012 - English
Deformable mirrors are the most commonly used wavefront correctors in adaptive optics systems. Nowadays, many applications of adaptive optics to astronomical telescopes, high power laser systems, and similar fast response optical devices require large diameter deformable mirrors with a fast response time and high actuator stroke. In order to satisfy such requirements, deformable mirrors based on piezoelectric layer composite structures have become a subject of intense scientific research during last two decades. In this paper, we present an optimization of several geometric parameters of a deformable mirror that consists of a nickel reflective layer deposited on top of a thin lead zirconate titanate (PZT) piezoelectric disk. Honeycomb structure of gold electrodes is deposited on the bottom of the PZT layer. The analysis of the optimal thickness ratio between the PZT and nickel layers is performed to get the maximum actuator stroke using the finite element method. The effect
Keywords:
Adaptive optics; mirrors
Available at various institutes of the ASCR
Optimization of electrode geometry and piezoelectric layer thickness of a deformable mirror
Deformable mirrors are the most commonly used wavefront correctors in adaptive optics systems. Nowadays, many applications of adaptive optics to astronomical telescopes, high power laser systems, and ...
Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application
Vápenka, David; Václavík, Jan
2012 - English
The article presents results of design and realization of dual-band antireflection coating on Gallium phosphide substrate. A layer stack of antireflection coating for bands 0.6-0.8μm and 3-5μm was designed using ZnS a MgF2 materials. Layer stack was deposited using thermal evaporation method. Expected transmittance spectra and the ones obtained on coated Gallium phosphide substrate are compared. Efficiency of anti-reflection coating is estimated and discrepancies are analysed and discussed
Keywords:
gallium phosphide; zinc selenide; zinc sulfide
Available at various institutes of the ASCR
Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application
The article presents results of design and realization of dual-band antireflection coating on Gallium phosphide substrate. A layer stack of antireflection coating for bands 0.6-0.8μm and 3-5μm was ...
U-probe for the COMPASS Tokamak
Kovařík, Karel; Ďuran, Ivan; Stöckel, Jan; Seidl, Jakub; Šesták, David; Brotánková, J.; Spolaore, M.; Martines, E.; Vianello, N.; Hidalgo, C.; Pedrosa, M. A.
2011 - English
A complex electrostatic-magnetic probe diagnostics, baptized as 'U-probe', is being prepared for measurement of properties of the filamentary structures in the edge plasmas of COMPASS tokamak. Probe will be composed of two identical towers. Each tower will house 3 sets of 3D coils, balanced triple probe and six single Langmuir probes each. The design of the probe is based on that of U-probe used on reversed field pinch RFX-mod and our combined electromagnetic probe at TJ-II stellarator. This new COMPASS diagnostic will measure vorticity and longitudial electric current of the plasma filaments. Analysis of the properties and, particularly, the correlation between filament vorticity and its current is expected to shed light into physics of filamentary structures in the tokamak plasma edge. The simulation of the probe surface temperature evolution as a function of expected incident heat loads within the COMPASS edge plasmas is presented.
Keywords:
edge plasma; filaments; tokamak
Available at various institutes of the ASCR
U-probe for the COMPASS Tokamak
A complex electrostatic-magnetic probe diagnostics, baptized as 'U-probe', is being prepared for measurement of properties of the filamentary structures in the edge plasmas of COMPASS tokamak. Probe ...
Dynamics of cavitation induced by focused tandem shock waves in water
Hoffer, Petr; Šunka, Pavel; Lukeš, Petr
2011 - English
Cavitation associated with the generation of shock waves in water was examined. To study these processes, a tandem shock wave generator, which generates two cylindrical pressure waves focused by a metallic parabolic reflector to a common focal region, was developed. The temporal evolution of cavitation generated by shock waves at the focal region was determined experimentally using high-temporal-resolution microphotography for a certain time delay between the first and second shock waves. Observation of the focal area also showed jetting cavitation bubbles with diameters of 100 m without presence of any rigid boundary. A theoretical model that provides analytical expressions for the temporal evolution of the pressure inside the cavitation bubbles and parameters of the pressure waveform of the second shock wave at the focal area was used to improve the same measurement by PVDF sensor gauges. On the basis of this model, the amplitudes of the compression and rarefaction parts
Keywords:
shock wave; cavitation bubble; Rayleigh-Plesset equation
Available at various institutes of the ASCR
Dynamics of cavitation induced by focused tandem shock waves in water
Cavitation associated with the generation of shock waves in water was examined. To study these processes, a tandem shock wave generator, which generates two cylindrical pressure waves focused by a ...
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