Using aluminum films combined with protective dielectric film is amethod of choice for many reflective applications in the visible (VIS) and the near infrared (NIR) range. An optical defect occurred during the introduction of the deposition aluminum (Al) films protected by a silicon dioxide (SiO2 ) protective film in our laboratory. Both films were deposited using an electron beam evaporator. S iO2 layers were deposited using the ion beam assisted deposition (IBAD). The results were not satisfactory. Produced films were matting and struggled with a significant reflectance decrease. The article presents an experimental approach which has been performed in order to eliminate the matting effect and the reflectance decrease. and Hliníková vrstva v kombinaci s ochrannou dielektrickou vrstvou je jedna z nejčastěji používaných možností pro výrobu reflexních prvků v oblasti viditelného a blízkého infračerveného světla. Při depozici těchto vrstev v naší laboratoři byl pozorován problém s degradací kvality ve formě viditelného zašednutí a výrazné ztráty reflektance. Hliníková i dielektrické vrstvy jsou nanášeny vakuovým odpařováním z elektronového děla. V případě dielektrické vrstvy je pak použita varianta zvaná IBAD (Ion Beam Assisted Deposition). Článek představuje výsledky experimentů, kterými byl nalezen optimální procesní postup eliminující degradaci optické kvality deponovaných vrstev.
This is a follow-up report on the viability of pathogenic Naegleria fowleri, Naegleria australiensis and Acanthamoeba castellanii isolates during 5 to 10 years of cryopreservation at –70°C. The greatest decrease in viability occurred with N. fowleri and the least occurred with N. australiensis. At 10 years of cryostorage, viability was 21% for N. fowleri, 32% for A. castellanii and 51% for N. australiensis.
The influence of water environment on natural frequencies of a Francis pump-turbine runner with the shaft is analyzed. The computations are executed by ANSYS program package based on finite element method. The fluid ‘equivalent mass‘ matrix concept is used. For solution, the Euler approach is used. Obtained natural frequencies and vibration mode shapes of the turbine runner with shaft in vaccum, in air and in water are presented. Computed natural frequencies and vibration mode shapes of the turbine runner with shaft in vacuum are compared to computed natural frequencies and vibration mode shapes of the turbine runner without shaft. and Obsahuje seznam literatury
A detailed analysis of dynamical properties of five-blade-bundle mathematical model was carried out with the aim to investigate how the damping elements made of rubber inserted into slots between blades heads influence the response curves at different distribution of exciting harmonic forces. Viscous-elastic linear Voigt-Kelvin model was used for modeling the rheological properties of damping elements. Constant values of stiffness and damping parameters were supposed at analysis. The orthogonality of excitation forces distribution to the other eigenmodes of blades bundle is applied at insulated selected resonance. and Obsahuje seznam literatury
In the paper there are deduced differential equations of the vibroisolation system of the ambulance couch. The kinematic excitation is realized in three directions: the vertical translation and the rotations around the both horizontal axes of the car. The suspension of the ambulance couch corresponds to this presumption and is made by the parallelogram; on the upper base there is a double level Cardan suspension.
The linearised system of the motion equations is stated and the preliminary analysis of the dependency of all the three natural frequencies on the selected parameters is made. By vertical kinematics excitation numerical simulation of the excited oscillations is made. and Obsahuje seznam literatury
Until now, the Latin Gradual and Hymn book from the beginning of the 16th century (Kutná Hora, České muzeum stříbra, shelf-mark 88/85), failed to raise the interest of musicologists. The main aim of this article is listing the polyphonic compositions not registered by the catalogue RISM B IV, 3–4. Even if the quality of writing of these polyphonic Mss. is low, it is an important source, containing several compositions (and contrafacta) which do not appear in other Bohemian sources of the same period.