National Repository of Grey Literature 35 records found  beginprevious25 - 34next  jump to record: Search took 0.00 seconds. 
Mikrostrukturní vlastnosti cementového kamene s příměsí metalupku Mefisto L15
Ščučka, Jiří
V tomto příspěvku jsou prezentovány výsledky orientačních testů, které byly prováděny na vybraných vzorcích cementového kamene s příměsí metalupku, s cílem posoudit vliv množství příměsi na základní mikrostrukturní parametry a stanovit optimální postup při mikrostrukturních analýzách materiálů podobného typu.
Fluorescenční mikroskopie a analýza obrazu mikroporušení hornin
Ščučka, Jiří ; Kožušníková, Alena ; Obara, B.
The paper presents analytical methods used at the Institute of Geonics ASCR for quantitative analyses of micro-fracturing arising in rocks under various loading conditions in laboratory. Primarily optical fluorescence microscopy and image analysis of sections saturated by fluorescence dye are used to these purposes. The full-automatic image analysis method for determination of intensity and distribution of micro-cracks in rock specimens is presented in the paper as well as the formerly used manually procedure.
Pulsating rotating waterjet during removing of surface layers
Sitek, Libor ; Bodnárová, L. ; Foldyna, Josef ; Hela, R. ; Ščučka, Jiří ; Jekl, Pavel ; Nováková, Daria
Paper deals with removing of concrete surface layers by high speed waterjet technology under laboratory conditions. Circumstances of removing of surface layers of various qualities by pulsating rotating jet were studied on concrete specimens. Results are compared to effect of continuous rotating jet on the identical concrete samples under the same operating conditions.
Repair of Concrete footing of high voltage pylon by polyurethane grouting - analysis of grouting effectiveness
Ščučka, Jiří ; Bódi, J.
The procedure of state estimation of concrete structure of a high voltage pylon footing before and after its repair by polyurethane grouting is presented in the paper. Analysis of the grouting effectiveness was realised on samples taken from inspection core drilling to the structure. The analysis consisted of rough determination of compressive strength of drill core sample, description of deformation behaviour of the specimen under the load, and structural-textural analysis of created geocomposite using method of fluorescence microscopy combined with image analysis.
Measurement of coke porosity by image analysis methods
Ščučka, Jiří ; Kožušníková, Alena
An effective method for visualization and quantitative analysis of coke porosity is presented in the paper. The method is based on image processing and analysis combined with fluorescence microscopy of impregnated coloured preparations and enables the determination of percentage portion of pores in the coke, mean pore-size, mean cell-wall thickness and their distribution.
Confirmation of presence of chemical grouts in grouted rocks - proving methods
Ščučka, Jiří ; Vaculíková, Lenka
The confirmation of a presence of chemical grouts in the pore system of fine-grained soils or in the fine cracks of grouted rocks and engineering constructions is a common requirement in the laboratory analyses of geocomposite material (polyurethane resin+rock/soil, polyurethane resin+building material). The combination of two analytical methods can be used for the reliable detection of the injection medium in the grouted rock environment: optical fluorescence microscopy+digital image processing, - Fourier transform infrared (FTIR) spectroscopy of the powdered rock/soil sample.
Application of image analysis in research into geocomposite materials
Ščučka, Jiří
The paper concerns possibilities of the image analysis application to the qualitative and quantitative evaluation of structure and texture of geocomposite materials - the noncohesive rocks injected with polyurethane resins. Understanding the relation between the structure and texture and physical mechanical properties of the materials represents one of the ways, how to determine indirectly probable properties and behaviour of geocomposites formed in practical applications.
Disintegration of concrete and rocks by modulated water jet: laboratory experiments
Sitek, Libor ; Foldyna, Josef ; Ščučka, Jiří
Problem of preparation of concrete and rock surfaces before repair using modulated water jet is a subject of the paper. Selected results of laboratory tests of disintegration of various types of concrete as well as rocks are presented and compared with results of concrete and rock disintegration by means of continuous water jet under the same operating conditions.
Physical properties of carboniferous and permian rocks: comparison
Konečný, Pavel ; Kožušníková, Alena ; Singh, S. K. ; Ščučka, Jiří
Results of tests of mechanical properties of Carboniferous rocks from Czech republic and Permian rocks from India and their comparison are presented on this paper. Influence of degree of coalification, mineral (maceral) composition and diagenesis on physical properties is visible from these experiments.

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