In the frame of advanced studies of coal structure the temperature conditions of coal origin were investigated through thermal stability of aluminum complexes in coal substance. These compounds were discovered by solid-state nuclear magnetic resonance measurements of 27Al as a part of coal substance closely bonded to organic mass of coal. In obtained spectra, Al-hexaphenoxide and Al-tetrahydroxy-diphenoxide complexes were identified. These complexes were further prepared and their thermal stability tested by thermal analysis method. It was found that a) they can originate under room temperature and atmospheric pressure and b) they are thermally stable only up to approximately 85 or 95 °C. As both Al-hexaphenoxide and Al-tetrahydroxy-diphenoxide complexes are the integrated constituents of coal substance it can be deduced that, in the beginning, coal was formed under very mild thermal conditions. As investigated materials, coals and clays from the Czech basins and gagatite from Poland were measured., Pavel Straka and Jana Náhunková., and Obsahuje bibliografii
This paper focuses on the impact of changes in temperature on one bay of St Vitus’ Cathedral in Prague Castle. The objective of the study is to simulate as correctly as possible the distribution of temperatures in the structure, and then to compute the thermal dilatation movements. Theoretical simulation of dilatation movements involves simulating the temperatures in the structure and then computing the displacements. Insolation and changes in air temperature around the structure are included in the temperature simulation. The computed temperature fields are used as a loading for computing the forces and deformations of one bay of St Vitus’ Cathedral. The theoretical deformation values obtained by means of the 3-D finite element model were compared with the measurements. The computed surface temperatures were also confronted with the surface temperatures measured in the interior and on the exterior of the cathedral. The results obtained from the simulations correspond well with the measured surface temperatures and deformations., Pavel Beran, Jiří Máca and Petr Fajman., and Obsahuje bibliografii
Polyaniline/montmorillonite (PANI/MMT) intercalate pressed into pellets using the pressure 28 MPa has been prepared in order to achieve two-dimensional conductivity which is close to pure PANI, however with improved mechanical and thermal stability (due to the presence of silicate). Structure-conductivity relationship has been investigated using X-ray diffraction analysis and diffraction patterns obtained from two perpendicular planes revealed the strong texture. The structural anisotropy led to the anisotropy in conductivity, which is much stronger for PANI/MMT than for pure PANI pellets. Anyway, the inplane conductivity is of the same order for both PANI/MMT and pure PANI pellets. The anisotropy factor, that means the ratio of in-plane conductivity and conductivity in the direction perpendicular to the pellet plane, was 328 (PANI/MMT pellet) and 6.7 (pure PANI pellet), respectively., Jonáš Tokarský, Kateřina Mamulová-Kutláková, Lucie Neuwirthová, Lenka Kulhánková, Vítězslav Stýskala, Vlastimil Matějka and Pavla Čapková., and Obsahuje bibliografii
The goal of this study is to determine the validity of morpholineaments network that was inferred based on morphostructural analysis of digital elevation model (DEM), by crosschecking with documented faults. The test field has been spread over the exploitation areas in the Zlaté Hory ore district. Various morphometric analyses such as slope, aspect, first directional derivative, gradient operator, combination of altitude and shaded relief, were chosen as particular tools of the morphostructural analysis. The results of each analysis were compared with the results of structural-tectonic mapping. The inferred morpholineaments network was compared with mining maps of the scale 1:500, which provide detailed information about tectonic deformation of rock massif in the area of interest and were used to image fault traces on the surface. The validity of inferred morpholineaments network was determined by authorized software SROV_TEKT, developed by the authors. The morpholineaments network resulting from the morphostructural analysis and tested by this software overlaps at 83 % of the documented main faults in the mines., Jan Jelínek, František Staněk, Jan Thomas, Tomáš Daněk and Jiří Mališ., and Obsahuje bibliografii
The case study of a ground steps creation due to underground mining in Upper Silesia Basin, where for many years was conducted intensive hard coal extraction has been presented in this paper. This type of linear discontinuous deformations is considered as an important threat to the surface building constructions and elements of underground technical infrastructure. This threat is even more important, that presently still we do not have methods for predictions of such phenomena, and protection of building constructions against such damages is difficult, if not impossible. On the basis of the analyzes results shown in the paper, the following factors were pointed, that favor the formation of mining-induced ground steps: the presence of fault outcrops in the vicinity of extraction fields, multiple extraction in several coal seams led to the same border and large values of tensile horizontal strain., Piotr Strzałkowski and Roman Ścigała., and Obsahuje bibliografické odkazy
GNSS meteorology is the remote sensing of the atmosphere (particularly troposphere) using Global Navigation Satellite Systems (GNSS) to deliver information about its state. The two currently available navigation satellite systems are the Global Positioning System (GPS) and the GLObal'naya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) maintained by the United States and Russia, respectively. The Galileo navigation satellite system, which is under supervision of the European Space Agency (ESA), is expected to be completed within the time frame of a few years. Continuous observations from GNSS receivers provide an excellent tool for studying the earth’s atmosphere. The GNSS meteorology has reached a point, where there is a need to improve methods not only to compute Integrated Water Vapor over the GNSS receiver, but also to investigate the water vapor distribution in space and time (4DWVD). Since 2008, the new national permanent GNSS network ASG-EUPOS (98 stations) has been established in Poland. 17 Polish stations equipped with GNSS receivers and uniform meteorological sensors work currently in the frame of the European Permanent Network. This paper presents the concept of the integrated investigations for NRT atmosphere model construction based on the GNSS and meteorological observations from ASG-EUPOS stations., Jarosław Bosy, Witold Rohm and Jan Sierny., and Obsahuje bibliografii
Seismic and rock burst hazards still currently appear to be important in most hard coal mines in Poland. Recently, there has been a significant increase in seismic activity in the Silesian rock mass, in comparison to previous years. In the period 2001-2010, hard coal mines experienced 33 rock bursts. The causes of rock burst occurrences are here presented, based on an analysis of the rock bursts that occurred in Polish hard coal mines. The scale of the rock burst hazard has been characterized with respect to the mining and geological conditions of the existing exploitation. The most essential of the factors influencing the status of rock burst hazard is considered to be the depth of the interval, ranging from 550 m to 1150 m. The basic factors that cause rock burst to occur are as follows: seismogenic strata, edges and remnants, goafs, faults, pillars and excessive panelling. The consequences of rock bursts are damaged and/or destroyed roadways. On this basis, the areas (ranges) of safe zones were selected as being those safe from rock burst hazard in roadways, according to the assessment conducted to establish different degrees of the risk., Renata Patyńska., and Obsahuje bibliografii
In 1965 the PD-1 mapping borehole was drilled in the classical location in Březno u Loun in the Ohře facies region. It was examined by many authors with various results. In 2006 the re vision of these results was pe rformed in archival samples. Carbonate content and insoluble residue minerals were determined. The gathered data were compared with similarly examined boreholes in the Bohemian Cretaceous Basin. The correlation showed that in the western and eastern Poohří region the profiles with different stratigraphy level were compared. After the elimination of this discrepancy the actual stratigraphy of the Poohří region can be easily compared with the other regions of the basin. The Č. Zahálka's statement of the equivalency of the sediment filling of the Ohře facies region and the Jizera formation in the Kokořín region is correct. This fact was validated by the Pd-1 borehole profile, where, due to a tectonic coupling, yet unknown, missing part of the youngest sediments of the Teplice and Březno formations (the real zone Xd) was conserved., Zdeněk Štaffen., and Obsahuje bibliografické odkazy
The NKCA and KVCA small-aperture (~ 90 m) seismic arrays in western Bohemia represent the second deployment of this type in the Czech Republic. The arrays have a regular triangular geometric configuration with high gain three-component seismographs in each corner of the triangle. This allows very weak local earthquakes to be detected with a high degree of precision and, thereby, substantially enhances the results of the pre-existing local seismic network (WEBNET). This paper reports on the pilot measurement period. It summarises the final configuration of the arrays and compares the derived results. The measured data have been analysed using the DP/EP system developed by NORSAR. This incorporates several array techniques such as beamforming, f-k analysis, and the cross-correlation method. It has been shown that during the study period, the levels of seismic activity recorded by the seismic arrays were up to fifteen times greater than the levels recorded by the pre-existing seismic network., Jaroslav Štrunc and Milan Brož., and Obsahuje bibliografii
Combustion of coal with limestone (a) and co-combustion of coal with limestone with wood, sewage sludge, soap and PTP (b) were performed in CFB. Inorganic matter composition and properties of all input materials were characterized. For this, chemical and coal petrography analyses of solid samples as well as their leaching tests, unburned carbon, and other properties were determined. There are not striking differences in composition of bottom and fly ashes from combustion/co-combustion data. In fly ash samples higher concentrations of Hg (about 2 ppm), As (about 800 ppm) and chlorine (about 400 ppm) are present than they are in bottom ash (0.002 ppm Hg, 250 ppm As, and 220 ppm Cl). Also relating concentrations of above elements determined in emissions are very similar for combustion/co-combustion regimes (about 0.010 mg.m-3 Hg, 0.027 mg.m-3 As and 24 mg.m-3 Cl). Content of unburned carbon in BA is below 2 wt.% and in FA below 0.6 wt.% in all combustion/co-combustion data. In FA samples the concentration of Hg, As, Se, etc. increases with increasing unburned carbon content, i.e. with decreasing grain size of FA. No significant differences in composition of emissions, bottom and fly ashes as well as in composition of water leachates were found from the combustion regimes I, II, III and IV., Martin Stach, Zdeněk Klika, Martina Nováčková and Václav Roubíček., and Obsahuje bibliografii