Modulus of elasticity of solid materials is determined by an experimental static tensile test on usual terms. The test is insufficient for hoses. Therefore, there is provided a special test for the determination of modulus of elasticity of hoses in reference to pressure and temperature of working liquid and environment temperature. The aim of the paper is to experimentally determinate modulus of elasticity of hoses depending on pressure of working liquid. and Za běžných podmínek se modul pružnosti pevných materiálů stanovuje experimentální statickou tahovou zkouškou. U hadic je tato zkouška nedostačující, proto se provádí speciální zkouška pro stanovení modulu pružnosti hadic s ohledem na tlak a teplotu pracovní kapaliny a teplotu okolního prostředí. Předmětem tohoto příspěvku je experimentální stanovení modulu pružnosti hadic v závislosti na tlaku pracovní kapaliny.
An experimental study on initial water flow through an empty pipe under conditions of free level and steady inflow into the pipe. The study presents results of the analysis of experimental values of wave front velocity and outflow from a pipe and their experimental eqautions. and Experimentální studie pojednává o napouštění prázdného potrubí vodou s volnou hladinou a s konstantním přítokem do potrubí. Studie předkládá výsledky rozboru experimentálních hodnot rychlostí čela vlny a odtoku vlny z potrubí i jejich experimentální rovnice.
This article presents the visualization of the cavitation bubble generated with laser-induced breakdown. The cavitation bubble is generated with 532 nm Nd:YAG laser beam, 10 ns short with two different optical setups. Here, we use direct optical way focusing the laser beam, and reverse way based on the focusing mirror. We are using different laser light power and visualize the laser probe in correlation of bubble characteristics. The visualization is set on long-distance microscopy and shadowgraph lightening method. The main goal of the research is to set the optical setup for the laser- -induced breakdown and to create the calibration relation curve for the bubble size dependence on the input energy of the laser beam. This calibration curve is related to the lifespan of each bubble, or the group of bubbles. and Tento článek pojednává o možnostech generování a vizualizaci jednotlivých kavitačních bublin buzením laserovým paprskem o vlnové délce 532 nm. Laserový svazek o délce záblesku 10 ns Nd:YAG laseru je formován pomocí dvou různých optických sestav, a to přímým zaostřením paprsku nebo zpětným zaostřením paprsku pomocí konvexního zrcadla. Při generování bublin bylo použito různých hodnot výkonů laserového svazku. Cílem bylo nalézt optimální optické nastavení laseru a vytvořit kalibrační křivku pro určení vztahu velikosti bubliny na výkon laserového svazku. Tato kalibrační křivka má také vliv na délku výskytu kavitující bublinky.
This paper is dealing with a detection of ground water flow in a granite massif. The flow was studied between boreholes of a testing polygon situated in a granite quarry. So called cross-hole (C-H) tests were used to detect fracture based connection between the boreholes. The tests were proceeded in steady-state ground water flow conditions. There were TV cameras used to detect a uranine tracer. The cameras were equipped by an orange filter and well defined blue light. A geometrical model of the fracture system in the area of interest was proposed according to C-H tests data. A hydrogeological model was calibrated using the very same data. Results pointed out subhorizontal fracture connection between the boreholes. Main advantages of the TV camera usage are possibil ities of accurate localization onto a structure, an immediate detection of tracer onset time and a continual data record., Karel Sosna, Milan Brož, Michal Vaněček and Michal Polák., and Obsahuje bibliografické odkazy
a1_In the present study, the effect of the medial septal (MS) lesions on exploratory activity in the open field and the spatial and object recognition memory has been investigated. This experiment compares three types of MS lesions: electrolytic lesions that destroy cells and fibers of passage, neurotoxic -ibotenic acid lesions that spare fibers of passage but predominantly affect the septal noncholinergic neurons, and immunotoxin - 192 IgG -saporin infusions that only eliminate cholinergic neurons. The main results are: the MS electrolytic lesioned rats were impaired in habituat ing to the environment in the repeated spatial environment, but rats with immuno - or neurotoxic lesions of the MS did not differ from control ones; the MS electrolytic and ibotenic acid lesioned rats showed an increase in their exploratory activity to the objects and were impaired in habituating to the objects in the repeated spatial environment; rats with immunolesions of the MS did not differ from control rats; electrolytic lesions of the MS disrupt spatial recognition memory; rats with immuno - or neurotoxic lesions of the MS were normal in detecting spatial novelty; all of the MS - lesioned and control rats clearly reacted to the object novelty by exploring the new object more than familiar ones. Results observed across lesion techniques indicate that: (i) the deficits after nonselective damage of MS are limited to a subset of cognitive processes dependent on the hippocampus, (ii) MS is substantial for spatial, but not for object recognition memory - the object recognition memory can be supported outside the septohippocampal system; (iii) the selective loss of septohippocampal cholinergic or noncholinergic projections does not disrupt the function of the hippocampus to a sufficient extent to impair spatial recognition memory;, a2_(iv) there is dissociation between the two major components (cholinergic and noncholinergic) of the septohippocampal pathway in exploratory behavior assessed in the open field - the memory exhibited by decrements in exploration of repeated object presentations is affected by either electr olytic or ibotenic lesions, but not saporin., M. G. Dashniani, M. A. Burjanadze, T. L. Naneishvili, N. C. Chkhikvishvili, G. V. Beselia, L. B. Kruashvili, N. O. Pochkhidze, M. R. Chighladze., and Obsahuje bibliografii