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Salek O.,Charles University | Matolin M.,Charles University | Taborik P.,Charles University | Stepancikova P.,Ustav Struktury A Mechaniky Hornin AV CR
Geoscience Research Reports | Year: 2014

Concentrations of natural radionuclides of K, U and Th along vertical profile of a research trench studying the Sudetic Marginal Fault were established by detailed focused gamma-ray spectrometric measurements. Geological scheme of the profile is shown in the Fig 1. Analyses of K, U, Th were carried out by two gamma-ray spectrometers, i.e. GS-256 and newly introduced GT-40S (Georadis). The GS-256 is a portable gamma-ray spectrometer of standard design, which was calibrated at calibration facility Stráž pod Ralskem, Czech Republic. Focusing of GS-256 detector was achieved by placing the probe in a ring-shaped lead shield (thickness 30 mm, height 130 mm, inner diameter 140 mm, weight 21 kg). Since the lead shielding is changing instrument's response to gamma-rays and its calibration constants, it is necessary to apply shielding correction factors when determining K, U and Th (Table 1). The gamma-ray spectrometer GT-40S is specially designed for focused measurements. The lead shielding (thickness 25 mm, inner diameter 70 mm, weight 9 kg) is built into the probe. The GT-40S was calibrated using Grasty's transportable calibration pads. The results of measurements by GS-256 gamma-ray spectrometer on profiles 1 and 2 are shown in Fig 2. The comparison of results acquired by using the GS-256 and GT-40S instruments is presented in Fig 3. The abnormality of the obtained radiometric data was statistically treated and tested using the range of ±3S (standard deviation) of the mean. The test has shown thorium anomaly to be bound to rocks of the fault zone, while concentrations of potassium and uranium have not indicated any significant change or affinity (Table 2, Fig. 2). Statistical identity of the results obtained by using the GS-256 and GT-40S instruments was tested by Student's t-test for paired samples based on a hypothesis that the results of measurements using two instruments are statistically not different. The test parameters are shown in Table 3. Potassium and uranium analyzed by the two instruments show small deviations close to magnitude of measurements errors. Concentrations of thorium established by the two gamma-ray spectrometers were found to be statistically identical.

Balek J.,Ustav Struktury A Mechaniky Hornin AV CR | Balek J.,Czech Technical University | Marek T.,Ustav Struktury A Mechaniky Hornin AV CR | Marek T.,Charles University | And 2 more authors.
Geoscience Research Reports | Year: 2014

České středohoří Mts. area has long been modeled by landslides. Just around the city Třebenice there are several active slope deformations. Mentioned landslide is exceptional because of its long-term activity disrupts just two linear structures. For this reason, the landslide was several times intensively investigated in the past and is therefore much better mapped than most surrounding areas. The aim of this paper is to summarize the historical and current developments in the landslide regarding its activity, its monitoring and various stabilization measures. In the modern history, the area was several times affected by landslide causing damages on railroad line and asphalt road. In the 70s and 80s line operation had to be stopped (Fig. 1). Therefore two remedy measures were realized. First one in 70s, was focused only on railway crossing area and may have decreased groundwater levels. Despite the implementation stabilization measures further landslide occurred in 1982 on a much greater extent than the previous one. In the response to this event was the construction of new measures aiming on one hand to reduce the groundwater level and on the other hand mechanically stabilize the landslide mass. Currently the railway body is considered stable, but this fact was never been verified by measurements. Trigonometric and extensometric measurements show displacements of some parts of landslide Aup to 30 mm per year (Fig. 3). Deformations are clearly visible on road surface. Moreover, small but permanent position changes in position of some reference points indicate, that some parts of the railway body may not be absolutely stable. It appears, that some parts of the rail stabilized housing show long-term movements in the direction of the slope. New precise leveling measurements were carried in order to check vertical stability of railway body.

Rockfall hazard is assessed using Rockfor.net, which is one dimensional tool for assessing the protective function of forests against rockfall. Three sites where chosen to test the tool with different morphological and forest conditions. For each site, it was evaluated how the boulder size and forest composition affects the probability of the rocks to surpass the forested slope. The Rockfor. net was also used for back calculations of past event, which happened during the floods in July 1997 in the village of Bystřička in the Vsetínské vrchy Hills. In this case, also a partial quantitative risk assessment with suggestions for risk management was performed.

Blahut J.,Ustav struktury a mechaniky hornin AV CR | Klimes J.,Ustav struktury a mechaniky hornin AV CR
Geografie-Sbornik CGS | Year: 2011

This paper presents an international concept of landslide hazards and risk studies. Basic terms are noted along with their English and German equivalents. Significant differences among their definitions are discussed. Other components of landslide risk, namely elements at risk and vulnerability, are presented as are other related terms. Attention is focused on differences in meaning among the basic terms used in social, technical and natural sciences. Attention is focused on differences in meaning of the basic terms in social, technical and natural sciences outlining possibilities of overcoming those differences to facilitate communication among them.

Havelcova M.,Ustav struktury a mechaniky hornin AV CR | Bicakova O.,Ustav struktury a mechaniky hornin AV CR | Sykorova I.,Ustav struktury a mechaniky hornin AV CR | Weishauptova Z.,Ustav struktury a mechaniky hornin AV CR | Melegy A.,National Research Center of Egypt
Fuel Processing Technology | Year: 2016

Sub-bituminous coal and admixtures with polyethylene terephthalate were co-processed. The main objective of the study was to produce coke and to determine how ratios of input raw materials affected its structure. All main product yields (coke, tar, gas) were characterized by petrological and chemical methods. The addition of PET to coal in coking blends had impacts on coke yield, its true density, volume contents of fissures and mean reflectance, volume and surface of pores, and the formation of aromatic structures in the coke. However, the properties of coke and gas did not change significantly until 20% of the coal had been replaced with PET bottles in the coal charge. © 2016 Elsevier B.V.

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