Milan Otáhal (1928-2017) was a leading historian studying the contemporary history of Czechoslovakia. In the 1960s, he was the head of the Department of Modern History of the Historical Institute of the Czechoslovak Academy of Sciences; in the early 1970s, he lost his job at the institute and was expelled from the Communist Party of Czechoslovakia. He was one of the fi rst signatories of Charter 77 and was active in the historical samizdat as an independent historian. Since the 1990s, his scientifi c activity was connected with the newly established Institute for Contemporary History. His main focus was the history of the anti-regime opposition and of the society between 1969 and 1989, and the role of students and intelligentsia in the change of the political situation in the end of the 1980s. He wrote a number of factographically rich and interpretationally distinctive publications on these topics. The author of the obituary mentions principal contributions of Milan Otáhal to the knowledge and understanding of Czechoslovakiaʼs most recent history, emphasizing that he was a historian who was not only intellectually refl ecting the period he was living in, but who was also intensively experiencing and co-creating it. and Přeložil: Jiří Mareš
The harmonic oscillations of water level changes with several hundred nanometers amplitudes and 10-3 [Hz] frequencies are irregularly observed with the water-tube tiltmeter. The effects are observed only by one of four gauges - the one closest to the entrance to underground. The other three gauges of water-tube tiltmeters are situated at the ends of the corridors and are significantly more distant from the entrance to the underground. The atmospheric pressure signals affect level of water in the instrument by inverse barometric effect. The water-tube tiltmeters can register water level variations associated with inverse barometric effects, which were produced by air pressure signals until 10-5 [Pa] magnitude. The amplitude of harmonic oscillations of water level is significantly large and amounts to 1/10 of tidal amplitude, that is 300 to 500 nanometers, which corresponds to 5 x 10-3 [Pa] of air pressure variations. Harmonic oscillations appear irregularly and their time of duration changes from few days until several weeks. The length of atmospheric wave of 10-3 [Hz] frequencies is of 1000 [km] and cannot be explained by any phenomenon from the outside surroundings or the inside of the underground. Resonance frequencies of air column in the hundred meters long underground corridors are of the order of single Hz. Absence of similar signals in measurements from the other three gauges suggests that the harmonic signals are not propagated through the Earth’s solid body but through the atmospheric medium. The observed micro-vibrations of air pressure are very low infrasounds which can be produced in large dimension space of thousand kilometers size. The open question is what is the origin of micro-vibrations registered by the water-tube tiltmeter., Marek Kaczorowski., and Obsahuje bibliografii
Instances are proffered where it seems Buddhists have been stimulated by Judeo-Christian material. Openness to wisdom emanating from a non-Indian Buddha is documented already in the Mahāyāna, but the majority of these present instances are taken from Theravāda literature. It seems material emanating from Jews was assimilated before the suttas were finalized. If so, "openness" established before being rationalized and lauded in the Mahāyāna.
The induced unsteady flow due to a stretching porous surface in a rotating fluid, where the unsteadiness is caused by the suddenly stretched surface is studied in this paper. After a similarity tranformation, the unsteady Navier-Stokes equations have been solved numerically using the Adams Predictor Corrector Method. It is found that there is a smooth transition from the small time solution to the large time or steady state solution. and Obsahuje seznam literatury a názvosloví
The unsteady Hartmann flow of a conducting incompressible non-Newtonian viscoelastic fluid between two parallel horizontal insulating porous plates is studied with heat transfer. A uniform pressure gradient which decays exponentially is imposed in the axial direction. An external uniform magnetic field and uniform suction and injection through the surface of the plates are applied in the vertical direction. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are considered in the energy equation. Numerical solutions for the governing momentum and energy equations are obtained using finite differences. The effect of the magnetic field, the parameter describing the non-Newtonian behavior, and the velocity of suction and injection on both the velocity and temperature distributions is investigated. and Obsahuje seznam literatury
In modern society, many people keep working hours different from the standard (9 hours, 5 days a week during conventional time of the day), a regimen leading to sleep deprivation and/or circadian desynchronization, and, consequently, to sleepiness, fatigue, impaired efficiency and ultimately to psychic and somatic complaints. Fortunately, sleepiness-related health and occupational hazards can be kept under control using scientifically tested precautions designed to help maintain wakefulness. Suitable work and rest scheduling and observance of the principles of sleep hygiene are of major importance there. In situations which interfere with sleep, it is possible to use hypnotics or behavioral techniques and melatonin for circadian regimen optimization. In situations when sleep loss is temporarily inevitable, options to be taken into account include work shift shortening, breaks for rest, naps of short duration or administration of vigilance enhancing drugs. In the future, risks associated with sleepiness could be mitigated by means of currently developed technologies for real-time detection of sleepiness.