National Repository of Grey Literature 8 records found  Search took 0.01 seconds. 
Utilization of secondary crystallization to increase resistance of cement composites to aggressive environments
Jambor, Vladimír ; Žižková, Nikol (referee) ; Bydžovský, Jiří (advisor)
This thesis is focused on the study of impact secondary crystallization on the mechanical properties of cement composites. The aim of the theoretical part this work is research and a comparison of specialist publications on the issue, the practical part deals with the verification secondary crystallization influence on the degradation of cementitious composites exposed to aggressive environment and assessment of the microstructure of these composites through electron microscopy.
Development of a New Repair Mortar Using Secondary Raw Materials
Figala, Petr
This paper deals with the research of a new repair mortar modified with secondary raw materials. The aim of the work is to develop a material characterized by chemical resistance suitable for the rehabilitation of sewer concrete structures. Resistance to aggressive sulphate solution and to attack by sulfuric acid was chosen as the key parameters for the choose of a final mixture. Chemical resistance was tested by simulating the exposure environment in laboratory conditions, according to the methodology of DIN 19573. The obtained results show that by suitable modification of the reference mortar it is possible to maintain the values of physical-mechanical characteristics and improve the chemical resistance of test samples. The final mixture will be further tested in field conditions.
Use of miniaturized Raman spectrometers under field conditions (sulphates)
Košek, Filip ; Jehlička, Jan (advisor) ; Osterrothová, Kateřina (referee)
Sulphates represent apparently an important component of Martian rocks and regolith. Their detection and identification is an integral part of the planned exploration missions, as they provide valuable information about the geological history of the planet. Also they could play a crucial exobiological role related with the possibility of existence of extinct or extant Martian life. This thesis provides a comprehensive overview of the occurrence and the geological situation of sulphates on the surface of Mars. The basic genetic factors responsible for formation of sulphates are introduced in terrestrial and Martian conditions. Furthermore, their significance is explained as indicators of geological factors and their connection with a possible Martian life. The second part presents method of Raman spectroscopy and its application in exobiology. The advantages and limitations of laboratory and portable instruments for analyzes exobiological samples are described. Identification capabilities of this method for determination of sulphates are shown, as well as its use on real locations considered as exobiological analogues. At the end, the current concept of Raman spectrometer for ExoMars rover is introduced. Keywords: Miniaturized Raman spectrometers, field conditions, sulphates
Utilization of secondary crystallization to increase resistance of cement composites to aggressive environments
Jambor, Vladimír ; Žižková, Nikol (referee) ; Bydžovský, Jiří (advisor)
This thesis is focused on the study of impact secondary crystallization on the mechanical properties of cement composites. The aim of the theoretical part this work is research and a comparison of specialist publications on the issue, the practical part deals with the verification secondary crystallization influence on the degradation of cementitious composites exposed to aggressive environment and assessment of the microstructure of these composites through electron microscopy.
The chemical and physical parameters of precipitation waters in the Stropnicko region.
MORBICEROVÁ, Iveta
This work aimed to evaluate long-term changes of selected chemical and physical parameters of rainwater from their own rain gauge stations Stropnicko. Chemical and physical parameters influence the rate of loss of substance in the landscape through the soil environment. In particular, the amount and concentration of dissolved sulphates and nitrates, affecting the value of the current pH. Samples were taken from their own rain gauge stations Stropnicko. Names of stations from which samples were taken are Horní Stropnice, Nakolice, Paseky and Nové Hrady. Rainfall were measured between the years 2005-2011 and were subjected to chemical analysis.
Causes of sulphate concentration increase in groundwater
Ďurďová, Libuše
Article deals with many genetical sources of sulphates in groundwater. Possibilities of releasing sulphates from natural rocks and from anthropogenic sources are explained. In case of processes caused by involvement of microbiological processes are listed in many representatives from bacteria world and enumerated related chemical reactions.
Isotopic composition of sulphates in groundwater
Ďurďová, Libuše
Isotopic composition of sulphur of sulphates in groundwater is given by geological structure, hydrogeological dynamic and so genetical conditions. Article gives results form research from Morava river watershead with increased mineralization and from mineral water of from spa.

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