The aim of this paper is an investigation of damping properties of polyurethane materials that were produced from polyurethane foam granules. There were used polyurethane materials with different thickness and inertial masses. After measurements of damping vibration, the polyurethane samples were compared and recommended in reference to their damping properties. and Tématem tohoto příspěvku je vyšetření tlumících vlastností polyuretanových materiálů vyrobených z polyuretanových pěnových granulí. Byly použity polyuretanové materiály s různými tloušťkami a setrvačnými zátěžemi. Po provedení měření útlumů vibrací polyuretanových vzorků byly jednotlivé vzorky porovnány a doporučeny z hlediska jejich tlumících vlastností.
The dynamical evolution of star clusters is discussed. We investigate especially the possible disruption of globular clusters by massive black holes, which have been proposed as the major constituents of dark galactic coronae. As an example, we discuss here the globular clusters in the elliptical galaxy M87. The proposed massive black holes could be responsible for the observationally indicated depletion of the globular cluster system in the inner parts of M87 with respect to the stellar light distribution of this galaxy.
Two pearl millet [Pennisetum glaucum (L.) R. Br. emend. Stuntz] hybrids GHB-30 and MH-179 were given defoliation treatments prior to anthesis comprising zero leaf to intact control. Keeping or removing even flag leaf only significantly altered the grain yield. With increasing leaf area (leaf numbers) the grain yield also significantly increased. Test mass showed more or less a similar trend. The leaves in the upper portion (nearer to sink) showed a greater contribution to the grain yield than the lower ones (away from sink). However, the highest leaf efficiency in terms of contribution per unit leaf area and the contribution by the whole leaf to the grain yield was recorded by 4th and 3rd leaf, respectively. The stem (covered with petioles) contributed to the extent of around 12 %. The existing leaves compensated to some extent for the defoliated ones. and A. K. Joshi ... [et al.].
This article presents an overview on series of Conferences and Colloquia on Dynamic of Machines organized in the first place by the Institute of Thermomechanics of Academy of Sciences of Czech Republic. This overview includes scientific meetings from the first Conference held in Liblice Castle in 1958 up to the last Colloquium in 2009. It is an extended paper presented in 2007 and accompanied by the exhibition of Proceedings organized in the frame of Colloquium 'Dynamics of Machines' 2007. and Obsahuje seznam literatury
Fluorescence microscopy and physiological examination revealed the presence of an inner cylinder of active photosynthetic cells located below the endodermis-like layer in stems of four of the six taxa of the tribe Salicornieae (Chenopodiaceae). and S. Redondo-Gómez ... [et al.].