National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Corrosion products phase identification using micro-Raman and FTIR
Majtás, Dušan ; Mácová, Petra
Phase identification of corroded metal objects might be problematic because corrosion products are usually a complex mixture of different phases. Furthermore, some of present phases may be either semi-crystalline or amorphous. The most suitable procedure is to use X-ray diffraction (XRD), for identification of crystalline phases in bulk, in combination with micro-Raman spectroscopy to obtain information on smaller scale and given location. Micro-Raman spectroscopy identifies crystalline and semi-crystalline phases. The literature also reports of the application of Mössbauer spectroscopy to identify amorphous phases. In this work, the combined use of Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy is evaluated. The methods may be interchangeable to some point. But is it safe to assume that all phases present can be detected?
Iron alloys outdoor corrosion and laboratory simulation - comparison
Majtás, Dušan ; Mácová, Petra ; Kreislová, Kateřina ; Příhoda, J.
Simulation of iron alloy corrosion is widespread used to predict corrosion resistance. The simulation using corrosion chambers or climatic chambers provides reasonable information on corrosion resistance, the corrosion rate however must be compared to real exposition as the corrosion in simulated environment is accelerated compared to real situation. However the composition of corrosion products and its structure is different question. The corrosion products composition is dependent on corrosion process. The phases present are most likely the same, most voluminous hydrated oxides and oxy-hydroxides on the outside where the less voluminous oxides are present in the lower layers. However this macroscopic phase structure may not fully describe the layered structure of corrosion products, thickness of corrosion products or mechanical properties. In the vicinity of crack in corrosion products the structure is more likely to be similar to the structure near the surface.
The formation of calcium carbonate polymorphs from concentrated salt solutions
Ševčík, Radek ; Mácová, Petra ; Viani, Alberto
This contribution is demonstrated the preliminary results of the study of the gel phase forming during the synthesis of calcium carbonate's polymorphs. Several samples were collected during the reaction and they were subsequently investigated with instrumental techniques e.g. scanning electron microscopy.
Cross-section analysis and mapping using Raman spectroscopy
Majtás, Dušan ; Mácová, Petra ; Kreislová, Kateřina
When dealing with corroded objects, it is necessary to identify the corrosion products to develop a proper treatment for this particular object. Using X-ray diffraction is still suitable to do the phase composition analysis of the material; however it does the analysis of the material in bulk. It is also possible to use SEM to analyze the structure of the corrosion layers on a cross-section by EBSD method; however this method is time consuming. It is more suitable to use Raman spectroscopy when studying the structure of corrosion layers. Using proper equipment, such as Raman microscope it is possible to do not only analysis of precisely given point, but it is also possible to do mapping (both 1D and 2D) of the cross-section. Taking map of surface also does need time, but is definitely less time consuming compared to EBSD method.
Qualitative and quantitative analysis of clay soils
Šašek, Petr ; Viani, Alberto ; Mácová, Petra
Smectite-to-illite conversion is an important mineralogical reaction that occurs during the diagenesis ofargillaceous sediment. Illite–smectite clay minerals are ubiquitous in sedimentary basins and they have been linked to the maturation, migration and trapping of hydrocarbons, rock cementation, evolution of porewater chemistry during diagenesis and the development of pore pressure. But, despite the importance of these clays, their structures are controversial. By combining layers of octahedra and tetrahedra several types of layered structures may be produced, which can form various types of clay minerals in nature. Clay minerals are divided into three main groups: kaolinite, smectite and illite. The aim of the study was to qualitatively and quantitatively analyse the clay minerals in soil samples and identification of unknown mineral found by exploration works. For this purpose XRD, Raman spectroscopy and SEM were employed.
Chemical and mineralogical analyses of stone sampled from Troja Castle, baroque staircase, Prague 7
Slížková, Zuzana ; Mácová, Petra ; Viani, Alberto ; Šašek, Petr ; Wolf, Benjamin
Chemical and mineralogical analyses of stone sampled from Troja Castle, baroque staircase, Prague 7.
Analysis of soils
Šašek, Petr ; Viani, Alberto ; Ševčík, Radek ; Mácová, Petra ; Machová, Dita
High concentrations of solid particles in the air may cause health problems. Sources of such particles can be natural processes, as well as human activity (e.g. coal mining, etc). Another source of contamination is the so-called secondary dustiness, which arises from vortex of already settled solids and dispersion into the atmosphere. Secondary dustiness formation is mainly affected by the surface moisture. The increase of humidity leads to agglomeration of the particles, resulting to their falling on ground, thus inhibiting their distribution in the atmosphere. The aim of the study was to analyse the soil dust particles collected on the filters of impactor, with respect to particle size and composition.
Comparison of the spectra of Vaseline samples using Fourier transform infrared spectroscopy
Mácová, Petra
The aim of the report was the comparison of 6 spectra of Vaseline samples. The spectra were collected using Fourier transform infrared spectroscopy (FTIR) in the attenuated total reflection (ATR) mode.
Profit and loss in the insurance sector in the Czech Republic
Mácová, Petra ; Bokšová, Jiřina (advisor) ; Randáková, Monika (referee)
The graduation thesis aims to specify and define, with respect to the Czech legislation, the profit and loss statement of the insurance companies and those items of revenues and expenses that are specific for the insurance companies. The thesis deals with the principal characteristics of the revenues and the expenses of the insurance companies as well as with the matter whether insurance companies can in any means influence their management result. It also focuses on the field of the insurance security -- what is the insurance security in the Czech Republic in relation to the European Union, and on the quantity limits of the profit and loss statement, in the Czech insurance sector. It also assesses the efficiency of the local insurance companies in relation to this, what is the share of the earned premium when taking in account the insurance claims, the operating costs and the management result. The graduation thesis came to the conclusion that an insurance company can quite easily influence its accounting management result and therefore it is necessary for the company to respect the relevant accounting measures. Furthermore, the Czech Republic in comparison to the other EU countries indicates relatively low level of insurance security. With respect to the efficiency it is possible to conclude (in relation to the year 2012 and the local insurance companies) that the earned premium comprises of more that 60% of the claimed damages, 30% of the operating costs and 10% of the earned premium represents the net profit.
Material analysis of renders of the St. Andrews´ church in Havlickuv Brod
Slížková, Zuzana ; Frankeová, Dita ; Petráňová, Veronika ; Mácová, Petra ; Zeman, Antonín ; Krejčí, Jan
Three samples of mortars with surface coatings were delivered by restorer. The aim of analysis was the determination of the binder quality and description of the layers´ system (thickness, chemical composition). To determine these characteristics optical and electron microscopy complemented by thermal analysis were performed.

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1 MÁCOVÁ, Pavlína
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