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
This research work involved the use of factorial design technique to investigate the adsorption of silver ions from water onto montmorillonite. There is a growing interest in using low-cost and commercially available materials for the adsorption of heavy metals. Clay particles are strongly anisotropic and exhibit faces and edges, which are very different in surface area and in chemical behavior. It has been reported that the abundance of clay minerals and their low cost has posed them a strong candidate as adsorbent for removal of heavy metal from wastewater. In this study, a factorial experimental design technique was used to investigate the adsorption of silver ions from water onto montmorillonite. The experimental factors and their respective levels that were selected include a pH of 3 - 8, an adsorbent dosage of 0.5-2.0 g/L and an initial silver ions concentration of 20-200 mg/L. The results were analyzed statistically using the Student’s t-test, analysis of variance, F-test and lack of fit to define most important process variables affecting the percentage silver ions adsorption., Feza Geyikçi and Hanife Büyükgüngör., and Obsahuje bibliografii
The paper presents the foundations of MAFA method, as well as its application to the pro cessing of new GPS and Galileo signals. The presented numerical tests have been carried out on the basis of data obtained from a hardware GNSS signal simulator as there are currently too few Galileo satellites on orbit. In the proposed methodology, first linear combinations have been formed using new GNSS signals. These linear combinations constitute a data set for a cascade adjustmen talgorithm employing extended MAFA method. Feasibility of a single-epoch precise positioning has been tested. The single-epoch positioning is particularly important for reliable real-time landslide and deformation monitoring. The obtained test results show a high success rate of the extended MAFA method. The number of the correct single-epoch solutions varied from 85 % to over 99 % depending on the baseline length and accuracy of an a priori position. Thus, the MAFA method may be successfully used with new GPS and Galileo signals, even for the processing of single-epoch data., Sławomir Cellmer, Jacek Paziewski and Paweł Wielgosz., and Obsahuje bibliografické odkazy
Most of natural materials contain traces of chlorine and it enters also to the combustion process. Chlorine products of combustions are usually inorganic hydrogen chloride vapors and chloride salts, nevertheless smaller amount of organic chlorine compounds are formed. Simpler of these organic compounds can act as greenhouse and ozone depleting gases; more complex compounds are directly dangerous for their mutagenity or extreme toxity like so called dioxines. Non-fossil natural materials and fuels derived of them can contain more chlorine than common coal. From the published research studies is evident that the formation of organochlorine compounds is limited to the temperature range 300-800 °C. At the higher temperatures, these compounds are destroyed. In the stage of flue gas cooling some chlorine may be by a "de novo" synthesis introduced to the organic form. Well-controlled combustion of alternative fuels need not contribute to the increase of amount of emissions of dangerous chlorine compounds. In our research were moreover studied the fuels with lower chlorine content. The experimental tests of the emissions from large-scale industrial fluid bed boiler indicated that substitution of large percentage of coal by alternative fuels had no significant effect., Kamil Wichterle, Jan Cieslar, Antonín Klečka, Zdeněk Klika and Václav Roubíček., and Obsahuje bibliografii
An identification of the responsible faults for the destructive earthquakes of 1894 in the Atalanti region was carried out by employing a novel application of 3D finite-difference wavefield modeling. Several faults proposed in the literature were tested in detailed 3D simulations, by also utilizing a detailed local 3D velocity model, as well as the local topography. The assessment of the most probable sources for these events was based on the correlation of reported damages with the distribution of the simulated peak ground acceleration. Furthermore, the distribution of the spectral amplitudes at higher frequencies that are related to the resonant frequencies of the local buildings on that time period was also used as an indicator. The general effect of the local 3D subsurface structure on the propagation of the wavefield and the spatial distribution of the ground motion was also investigated. The Malessina fault was identified as a probable source for the main event of 20/4/1894 based on the results of the 3D modeling, whereas the 3D effect was found to be a highly contributing factor to the distribution of the simulated ground motion., Mouzakiotis Evangelos, Karastathis Vassilios, Voulgaris Nikolaos,Papadimitriou Panagiotis, Sboras Sotirios and Gerolymatos Ilias., and Obsahuje bibliografii
The paper presents the results of monitoring study undertaken during the period 2008 - 2010. The study recorded the displacement of tectonic structures in the Strašín Cave (SW Bohemian Massif). The derived results were compared, among others, with data recorded over the same time period across the Bohemian Massif in the EUTecNet (tectonic displacement monitoring net - see www.tecnet.cz), which is managed by IRSM ASCR. The rate of recorded displacement is mostly in order of hundredths mm/year with maximal value recorded in vertical component at site Strašín 2, about 0,16 mm/2,5 years. Whilst recorded displacement can indicate blocks subsidence into the cave empty space, the periods when displacement occurred correspond to periods of increased movement activity recorded for example at the opposite side of the Bohemian Massif, along the Sudetic Marginal Fault. Moreover, both periods are simultaneous with extraordinary earthquakes that affected western and southern part of the Bohemian Massif in 2008 and 2009., Josef Stemberk and Filip Hartvich., and Obsahuje bibliografii
Two seismic sources were tested on different surfaces during acquisition of a 5.5-km long high resolution seismic reflection (HRS) profile on the Ljubljana Moor in central Slovenia. Maximum target depth range of the survey was 200 - 300 m. Nine different combinations of source-surface conditions were analysed. Seismic sources included a seismic shotgun and an accelerated weight dropper system. The HRS profile crossed different surfaces including: paved roads, gravel roads, ploughed fields, grasslands and marshlands. Seismic source performance on different surfaces was evaluated through frequency and S/N ratio analyses of seismic data, and analysis of source-generated coherent noise appearance on seismograms. Results show that both seismic sources are suitable for some of the surfaces found in the surveyed area. The accelerated weight dropper produced the best results on gravel road surface, but poor results were found on grassland and ploughed fields. The seismic shotgun produced the best results in water-saturated soil on marshlands. It performed less favourably in unsaturated soil, generating more coherent noise. Water-saturated marshland surface and gravel road surfaces were found to be the most favourable for acquisition of high-resolution seismic reflection data on the Ljubljana Moor., Jure Atanackov and Andrej Gosar., and Obsahuje bibliografii
Parameters of finite seismic source model were determined for a set of 36 selected events of the West Bohemia 2000 earthquakes swarm (Ml from 1.7 to 3.0) using stopping phases method. Two stopping phases are generated along the source border where the rupture process terminates and these phases form Hilbert transform pair, which is also the criterion for their identification. Circular and e liptical source models were considered and corresponding source parameters were calculated by inverting interpreted stopping phases delays. As generalization of circular to elliptical model was found to be statistically insignificant, only results related to the circular source including error estimates are presented. Our results are in a good agreement with previously published theoretical formula concerning source radius and magnitude and also fairly well confirm general theoretical assumption about constant stress drop. The determined stress drop ranges between 1 - 10 MPa with the typical value of 2.4 MPa., Petr Kolář and Bohuslav Růžek., and Obsahuje bibliografické odkazy
The oldest mine cavities of the Jeroným Mine were already mined out more than 400 years ago. That is why it is necessary to determine the stability of individual parts of underground spaces. The assessment of stability of mine cavities is based on the long-term monitoring of chosen parameters. A distributed measurement network has been operated here using several different types of sensors. A laser distance meter that is used for measuring the height of a large chamber is one of these sensors. The results obtained from this monitoring are presented. Even if no apparent correlation seems to be visible between Earth’s tides and LDM variations, some features of recorded data, like dynamical frequency crossover in the power spectrum, could be due to the tidal cycles of the Earth., Zdeněk Kaláb, Markéta Lednická, Jaromír Knejzlík and Luciano Telesca., and Obsahuje bibliografii
Using of shaped conical borehole bottom to determination of the stress tensor changes induced by changing of geomechanical situation is described in this paper. The measured strain changes on gauge probe are caused not only by the stress changes evocateg by progress of long wall. The some deformation started imediatelly after instalation when the long wal didn't move. In paper are discussed the eventu alities of this phenomenon too., Lubomír Staš, Kamil Souček and Jaromír Knejzlík., and Obsahuje bibliografické odkazy