Ústav struktury a mechaniky hornin

Nejnovější přírůstky:
2018-03-09
13:20
Field measurement of natural electromagnetic emissions near the active tectonic and mass-movement fractures in caves
Trčka, T. ; Macků, R. ; Koktavý, P. ; Škarvada, P. ; Baroň, I. ; Stemberk, Josef
Laboratory tests on a wide range of solid materials shoved that the electromagnetic emission (EME) signals are generated during the samples mechanical stress. EME anomalies have been observed also under natural conditions in association to fracture processes, tectonic loading, stress redistribution and crack propagation prior to earthquake or in relation to deep-seated gravitational mass movements. This paper describes a first prototype of the Emission data logger, which was specially developed for the continual EME monitoring in field conditions. Our equipment has been installed and tested in Obir Caves (Austria) at an active tectonic fault. The pilot long-term EME measurement results from this location are also presented in this paper.

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2018-03-09
13:20
Valley evolution of the Biala Lądecka drainage network during late Cenozoic, Lower Silesia, Poland
Stemberk, Jakub ; Štěpančíková, Petra ; Tábořík, Petr ; Coubal, Miroslav
Biala Lądecka (Biala Kłodzka) river is located in Lower Silesia (Poland) and its valley separates Góry Złote Mts.\n(Rychlebské hory Mts.) on the NE from Góry Bialskie Mts. on the SW. We conducted geomorphic investigations on the Biala\nLądecka river basin, in order to determine if Quarternary tectonic activity at the Bělský fault (or near Marginal Sudetic fault) is\ncontributing to the river’s asymmetry. Our research was focused on analysis of selected landforms, DEM parameters,\nmorphometric indexes and their spatial distribution which could potentially indicate recent tectonic activity in the area. At\nselected places geophysical measures were used to discover proper location and structure of Bělský fault or presence of\nsuggested morpholineaments. Preliminary results suggest a Quaternary tectonic activity for the Bělský fault. Moreover we tried\nto clarify nowadays stress regime in study area based striae measurement on fault planes and precise monitoring of selected\nfaults using TM-71 device.

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2018-03-09
13:20
Late Quaternary activity of slow-slip intraplate Mariánské Lázně fault as revealed by trenching and shallow geophysical survey; Bohemian Massif (Czech Republic, central Europe)
Štěpančíková, Petra ; Fischer, T. ; Hartvich, Filip ; Tábořík, Petr ; Rockwell, T. ; Stemberk, Jakub ; Široký, J. ; Sana, Hamid
The NNW-SSE trending Mariánské Lázně Fault (MLF) zone is situated in the western part of the Bohemian Massif (Czech\nRepublic, central Europe) where it intersects NE-trending Cenozoic Eger rift. The northern segment of the MLF controls the\nmorphologically pronounced mountain front of Krušné hory Mts. and eastern limit of Cenozoic Cheb basin, which is famous for\nearthquake swarms (max. ML=4.6) and CO2 emanation. We performed 2D and 3D geophysical survey (electric resistivity\ntomography, ground penetration radar) and 3D trenching to look for large surface-rupturing prehistoric earthquake responsible\nfor pronounced moutain range front. Seven excavated and six hand-dug trenches revealed a complex geology and deformation\nat the study site probably as a result of right-lateral transpression during Late Quaternary. Two Holocene earthquakes 1150-590\nBC and 780-1000 AD were inferred from 14C dating of faulted Holocene colluvium with corresponding magnitudes Mw=6.7-7.0.\nThe latter one is the youngest documented surface-rupturing event in central Europe.\n

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2018-03-07
15:28
Optimizing and Evaluating the Biocompatibility of Fiber Composites with CaP Additives
Suchý, Tomáš ; Sucharda, Zbyněk ; Balík, Karel ; Sochor, M. ; Bačáková, Lucie
Composite materials based on a polyamide fabric (aramid) and a polydymethyl-siloxane (PDMS) matrix were designed for application in bone surgery. In order to increase the bioactivity, 2, 5, 10, 15, 20 and 25 vol. % of nano/micro hydroxyapatite (HA) and tricalcium phosphate (TCP) were added. The effect of the additives on the biocompatibility was studied. It appears that nano additives have a more favorable effect than micro particles on mechanical properties. For final application of the composites as substitutes for bone tissues, 15 vol. % of nano hydroxyapatite additives is an optimum amount: in this case both the mechanical properties and the biological properties are optimized without distinct changes in the inner structure of the composite.

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2017-12-07
15:36
Hydrogen charging of fuel cladding methodology
Krejčí, J. ; Kabátová, J. ; Kočí, J. ; Weishauptová, Zuzana ; Vrtílková, V.
Hydrogen content is a very important parameter for mechanical properties of fuel cladding. The methodology of developed hydrogen charging is described.

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2017-12-07
15:36
Předhydridace vzorků slitiny Zr1Nb
Weishauptová, Zuzana ; Jandečková, Alena
Zpráva uvádí výsledky hydridace vzorků slitiny Zr1Nb.

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2017-07-03
17:28
Rehabilitace strusky
Hanzlíček, T. ; Perná, Ivana ; Šupová, Monika
Příspěvek mapuje historické souvislosti vzniku haldy vysokopecní strusky na Kladně. Dále charakterizuje chemické a mineralogické složení a nabízí vysvětlení odlišného složení spodních aktivních a vrchních neaktivních vrstev. Bylo zjištěno, že pokud struska obsahuje aktivní složky ve formě neuspořádaných gehlenitických podílů, bude možné ji snadno přepracovat pomocí alkalické aktivace v hodnotnou, stabilní a ve vodě nerozpustnou hmotu.

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2016-02-08
14:39
A brief introduction to the geology of the Moldanubian batholith
Verner, K. ; René, Miloš ; Žák, J. ; Janoušek, V.
Emplacement processes and tectonic setting of the Moldanubian batholith. The batholith consists of multiple intrusive units (plutons, stocks and dykes), predominantly composed of granitic to granodioritic rocks with either S- or transitional I/S-type.

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2016-01-11
14:39
Texturní vlastnosti Zr-slitin
Weishauptová, Zuzana ; Jandečková, Alena
Provedená studie je zaměřena na identifikaci vlivu předoxidace na texturní charakter korozních vrstev vzorků Zr slitinv E110EDU po expozici na teplotu 1100 oC v časové závislosti na expoziční době.

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2015-10-05
15:52
Origin of “rock cities”, pillars and cleft-conduits in kaolinite-bonded sandstone: New insight from study in sandstone quarry where landforms recently evolve
Bruthans, J. ; Soukup, J. ; Schweigstillová, Jana ; Vaculíková, J. ; Smutek, D. ; Mayo, A. L. ; Falteisek, L.
Based on measurements of relative erodibility, ambient and water-saturated tensile strength at natural and quarry exposures three distinct kinds of surfaces were distinguished (erodible sandstone, sub-vertical fracture surfaces and case hardened surfaces). Erosion proceeded along highly fractured zones.

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