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  • Author or Editor: Gábor Kovács x
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Authors: József Kovács, László Márkus and Gábor Halupka

The fluctuation of underground karstwater levels constitutes an inherently random, very complex time-dependent phenomenon further complicated when human interference disturbs the natural course. However, its structure can be explored by identifying only a few latent effects or factors (usually of significantly simpler dynamic structure), that are the driving forces behind it. The correct statistical tool to determine latent effects from the temporally interdependent observations is dynamic factor analysis (DFA). Analogously to ordinary factor analysis, DFA also determines loadings representing the measure of intensity of the latent effect corresponding to the factor. The obtained factor-intensities provide essential information on the geologic environment, improving the chance of correct decisions when environmental issues are on the agenda. In the given case the factors correspond to the infiltration and water extraction; hence, the intensities appear to be connected to aquifer vulnerability. Intensive water extraction increases the danger of contamination of an aquifer, since overpumping may establish contact with a distant, already polluted storage. High-intensity infiltration also increases vulnerability by helping local entry of any surface contaminant into the aquifer. Hence, the loadings and the measure of intensity can be regarded as important markers of vulnerability of the aquifer.

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Authors: Péter Tanos, József Kovács, Ilona Kovácsné Székely and István Gábor Hatvani

Abstract

The River Tisza is one of Central Europe's most important rivers. In the last one and a half century numerous anthropogenic activities have influenced its watershed. As a result measures need to be taken to protect its water quality, necessitating a comprehensive picture of the spatial and temporal variability of its processes, which this study aims to extend further. In this study five sampling locations were analyzed in the upper section of the Tisza over the time interval 1974–2005, dealing with 24 parameters using multi-variate data analysis methods. Employing time series analysis and taking the river's tributaries into account, the strong influence of the River Szamos was pointed out, while stochastic connections indicated the influence of the Tiszalök Water Barrage System on the spatial variation of the Tisza's processes. Finally, by using principal component analysis (PCA), the different background factors were revealed in space and time (seasonal separation) as well. During summer the processes tended to be nitrogen-related, while during winter inorganic compounds play a greater role. Most importantly, spatial variety was observable in the factors.

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Authors: Edit Borbás, József Kovács, Katalin Fehér, Gábor Vid and István Gábor Hatvani

Abstract

Water was observed in the sediment of Baradla Cave, located in Northeast Hungary. In order to investigate its characteristics wells were drilled. Hydrochemical samples were taken directly from the wells and from the cave stream on several occasions between November 2009 and April 2010. In February 2010 there was an opportunity to observe how the chemical composition of the waters of the creeks and the sediments altered during the snow melt. Several chemical parameters of the samples were analyzed. Based on the results of the hydrochemical analyses cluster analysis was applied to define the relationship between the sampling points. Discriminant analysis was conducted to verify the classification. As a result of the classification, the water of the observation wells in the sediment proved to be distinct from the water of the cave's creek and the springs on the surface.

Research shows that there is no permanent connection between the water in the cave sediment and the water of the cave creek in the cave water system.

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Authors: Péter Bajcsi, Tamás Bozsó, Róbert Bozsó, Gábor Molnár, Viktor Tábor, Imre Czinkota, Tivadar M. Tóth, Balázs Kovács, Félix Schubert, Gábor Bozsó and János Szanyi

Our research team has developed a new well completion and rework technology involving lasers. The system is made up of a high-power laser generator and a custom-designed directional laser drilling head. The laser head is attached to a coiled tubing unit to maximize production and to carry out special downhole tasks. In this phase of the development effort, laser technology is particularly well suited to cost-efficiently drill short laterals from existing wells in a single work phase, drilling through the casing and cement as well as the formation. The technology, which is an extended perforation solution, enables a more intensive interaction with the downhole environment and supports cutting edge subsurface engineering scenarios such as barite removal. Laser-induced heat treatment appears to be a suitable alternative to effectively remove the almost immovable deposits and scales from thermal water-well pipes.

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