2014, Volume LX, Issue No.2, ISSN 1802-5420
  • Homogeneous Magnetic Field Source for Attenuated Total Reflection

    Michal Lesňák, František Staněk, Jaromír Pištora, Jan Procházka

    The paper is focused on the study of two-dimensional magnetic field distribution used for an analysis of samples containing magnetically active films by means of the Attenuated Total Reflection (ATR) method. The design of a proposed electromagnet and the magnetic field model computation are presented together with the results obtained from magnetic field distribution measurement. The ATR method can provide information about a thin film thickness, refractive index, and attenuation in addition to the perfunctory coupling of an optical wave into and off a waveguide. The prism coupling conditions are determined for magnetic structures with induced anisotropy.
    The prism – a film coupler is located in the central cavity of a magnetic yoke. By current switching in the coils, we can change the amplitude and magnetic field direction in order to modulate the induced anisotropy in a thin film with magnetic ordering. By the in-plane modulation of the magnetization direction in the samples, we can change the rotation and elasticity of outgoing light.

  • Possibilities for Simulating the Smoke Rollback Effect in Underground Mines Using CFD Software

    Vancho Adjiski

    The effect of fire generated smoke rollback in underground mines can be dangerous and a potentially fatal threat to all who are endangered by the fire. Three critical stages in the process of smoke rollback are 3D local phenomena that can be analysed by CFD software simulations. With the help of a 3D-CFD analysis we can observe the critical stages of smoke rollback and their reaction to a ventilation network. The CFD provides the opportunity to expand the range of prediction of smoke spread for a wide spectrum of airflows, fire intensities, mine-section inclinations and layouts. The paper deals with the possibilities for simulating the smoke rollback effect in underground mines using the CFD software. For the purposes of this research paper, the PyroSim software from the company Thunderhead Engineering was used to create three different CFD fire scenarios and then observe the critical stages of smoke rollback effects.

  • The Application of Open-source and Free Photogrammetric Software for the Purposes of Cultural Heritage Documentation

    Karol Bartoš, Katarína Pukanská, Janka Sabová, Gabriel Weiss

    The documentation of cultural heritage is an essential part of appropriate care of historical monuments, representing a part of our history. At present, it represents the current issue, for which considerable funds are being spent, as well as for the documentation of immovable historical monuments in a form of castle ruins, among the others. Non-contact surveying technologies – terrestrial laser scanning and digital photogrammetry belong to the most commonly used technologies, by which suitable documentation can be obtained, however their use may be very costly. In recent years, various types of software products and web services based on the SfM (or MVS) method and developed as open-source software, or as a freely available and free service, relying on the basic principles of photogrammetry and computer vision, have started to get into the spotlight. By using the services and software, acquired digital images of a given object can be processed into a point cloud, serving directly as a final output or as a basis for further processing. The aim of this paper, based on images of various objects of the Slanec castle ruins obtained by the DSLR Pentax K5, is to assess the suitability of different types of open-source and free software and free web services and their reliability in terms of surface reconstruction and photo-texture quality for the purposes of castle ruins documentation.

  • Gamma Radioactivity of the January 2013 Rainfall in Ostrava

    Petr Alexa, Petra Količová, Radim Uhlář

    Gamma radioactivity of an 8 mm thick ice layer formed after a modest rain on 21 January 2013 in the VŠB-Technical University of Ostrava campus was analyzed and gamma-ray emissions from primordial 40K have been found. Cosmogenic 7Be produced mainly in galactic cosmic-ray spallation processes on atmospheric nitrogen and oxygen and 226Ra, 235U and 137Cs have been also observed.

  • The Foggara: A Traditional System of Irrigation in Arid Regions

    Remini Boualem, Achour Bachir, Kechad Rabah

    This article discusses the traditional irrigation system in the oases of Touat, Gourara and Tidikelt. Since centuries, farmers use the system of foggaras for irrigation of palm groves and gardens.
    The results obtained following the inquiries and investigations carried out on the sites of foggaras, showed that since the eighties, drilling works multiplied in the oases of Touat, Gourara and Tidikelt. However, despite the application of these new techniques of water catchment, farmers still irrigate their gardens by traditional methods. For social, economic and environmental problems, foggaras degrade more and more; 50% of the foggaras decayed. Currently, the discharge of foggaras in service greatly diminished. The adoption of modern catchment techniques entails to the lowering of the water table.

2014, Volume LX, Issue No.1, ISSN 1802-5420
  • Influence of schematization detailness on the results of rainfall-runoff modelling in the Lubina river basin

    Martin Adamec, Lukáš Noska, David Vojvodík

    This paper, in a form of a case study, deals with the influence of detailed basin schematization on the results of rainfall-runoff modelling. Three schematizations with dissimilar details were created for the study area and subsequently a rainfall-runoff simulation was carried out by means of the HEC-HMS programme for a precipitation event. Resulting hydrographs were further compared with a real discharge measured in the closing profile of the model basin. The model basin is the Lubina River basin occupying c. 160 km2, characterized by significant altitudinal articulation and variable land use, so the comparison was not limited to one landscape type. The study also includes statistical evaluation of model accuracy by means of the Nash-Sutcliffe method. Finally, the results are discussed as well as probable reasons for the behaviour of the models.

  • Heavy metal contamination of landscape componets in surroundings of closed mercury deposit in Malachov (Slovakia)

    Jana Dadová, Jiří Kupka, Peter Barto, Erika Remešicová, Tomáš Štrba

    The present study investigates mercury contamination of soil, groundwater, surface water, vegetation and food commodities (fruit, vegetable, mushroom, and fish) close to the abandoned Hg deposit in Malachov, Central Slovakia. The soil was classified as cambi-soil (rendzina). Maximum concentrations of Hg (44.24 ppm) were found in the soil from the area nearby old mining activities in the Veľká Studňa locality. In the groundwater, 0.84 μg.L-1, and in the surface water, even 394 μg.L-1 of Hg content was found. Also plant tissues and mushrooms are Hg-contaminated (in the root of Salix fragilis, the Hg content was 22 mg.kg-1). The Hg concentration decreases in general in the following order: root, branch/stem, and leaf/needle. In the food commodities, the Hg content does not exceed the Slovak law limits. The Hg content in trout muscle (from the local Malachovský brook) is 252 μg.kg-1 and in liver 402 μg.kg-1.
    The calculation of an AMD formation potential (neutralisation potential, total acidity production, net neutralisation potential) is discussed as well. The value of the total acidity production potential (sensu Sobek et al., 1978) is low (1.562 – 3.125; with exception of a single sample, in which it increased to 9.375). On the other hand, the abundant presence of dolomite rocks causes a high neutralization potential value (up to 812.84). This result suggests that the assumption of the AMD production is excluded and the environmental risk from this viewpoint might be neglected.

  • The evaluation of selected air pollutants in Košice for the period 2008-2010

    Marcela Gergeľová, Žofia Kuzevičová, Štefan Kuzevič

    In general, air quality is determined from the concentrations of pollutants in ambient air. Air quality criteria (limit and target values, margin of tolerances, upper and lower assessment thresholds) are based on the current legislative framework. In Slovakia, the air quality criteria are imposed by Decree No 360/2010 Coll, on air quality, of the Ministry of Environment. In relation to the implemented measurements, it is necessary to choose effective tools needed for the pre-processing and post-processing of overall air quality assessment. The article aims at applying suitable GIS tools in the assessment process of air quality in the Košice agglomeration for the selected period 2008-2010. In the overall assessment of the area in question, the processing of information on emissions declared as particulate matter (PM) was considered in terms of a conservative approach to the assessment of air quality for PM10. For the assessment, the yearbooks and reports on air quality in Slovakia in 2008-2010 of the Slovak Hydrometeorological Institute (SHMI) and professional publications were used.

  • Possibilities of application of static investment appraisal methods for optimizing purchase under conditions of mine rescue service

    Jana Magnusková, Zdeněk Pavelek, Lucie Krčmarská

    The present article focuses on the importance of making investment decisions and its long-term effect on the economy of companies. It presents a specific investment in the recovery of rescue equipment used for interventions in the irrespirable or deleterious environment on an example of the company HBZS, a.s. The objective is to evaluate the effectiveness of the investment project using static methods in relation to setting an optimal price level for leasing the equipment. The optimization of such setting is examined in terms of the economic lifetime of relevant tangible fixed assets.

  • Analysis of geodetic network established inside the Dobšinská ice cave space

    Juraj Gašinec, Silvia Gašincová, Vladislava Zelizňaková, Jana Palková

    The present article summarizes the progress and results of geodetic works during the construction of a geodetic network inside the Dobšinská Ice Cave underground space to monitor temporal and spatial changes in its ice filling. In order to objectively evaluate the changes, parameter estimations of the first- and second-order of the geodetic network from the set of field geodetic measurements were provided, and a robust analysis of the network was applied in terms of the assessment of impacts of potential outlier measurements on the network geometry.

  • Overview of research and use of indicator gases of coal spontaneous combustion in China

    Xiyang Feng, Alois Adamus

    The beginnings of research and use of results in the area of indicator gas application for early detection of spontaneous combustion of coal in China comes from the sixties of the last century. The significant development occurred in the nineties, when the program “Characteristics of the adsorption of coal oxygen and its application in the prevention of mine fires” had been completed. The paper briefly describes an overview of the historical development, achievements, experimental methods, laboratory equipment, legislation, and the outlook for the use of indicator gases of coal spontaneous combustion in China.