Search Results

You are looking at 1 - 10 of 14 items for

  • Author or Editor: D. Brandová x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

Thermal analysis combined with mass spectrometry was applied to radiocarbon dating procedures (age determination of carbon-containing samples). Experiments carried out under an oxygen atmosphere were used to determine carbon content and combustion range of soil and wood samples. Composition of the shell sample and its decomposition were investigated. The quantification of CO2 formed by the oxidation of carbon was done by the application of pulse thermal analysis. Experiments carried out under an inert atmosphere determined the combustion range of coal with CuO as an oxygen source. To eliminate a possible source of contamination in the radiocarbon dating procedures the adsorption of CO2 by CuO was investigated.

Restricted access

Abstract  

Thermal analysis combined with mass spectrometry was applied to radiocarbon dating procedures (age determination of carbon containing samples) to determine the optimal temperature range for the reduction of CO2 over metallic cobalt of various particle sizes. Experiments were carried out to show the different catalytic activities of cobalt of particle sizes 1, 1–45 and 44 m. The morphology of the cobalt samples and the deposited carbon were investigated. The quantification of CH4 and CO formed during the reduction of CO2 was done by means of pulse thermal analysis.

Restricted access

Abstract  

In our laboratory, the synthesis of new inorganic pigments is followed by thermal analysis using a Derivatograph apparatus. The first information about the temperature region of the formation of the pigments investigated is provided by thermal analysis. The main attention is directed to the preparation of high-temperature colour pigments, lightfastness colour pigments, anticorrosive pigments, new ecological inorganic pigments and luminescent pigments. All inorganic pigments are useful for colouring of ceramic glazes, enamels, plastics, paints, cements and other building systems. The synthesis of all these pigments is based on temperature calcination of starting materials. Tens of new inorganic pigments have been prepared thanks to methods of thermal analysis. These synthesis are described in more than 100 Czech patents.

Restricted access
Restricted access

The mechanism of the dehydration and condensation reaction taking place during calcination of Co1/2Ca1/2(H2PO4)2.2H2O has been followed by means of thermal analyses at non-isothermal (dynamic) and at quasi-isothermal-isobaric conditions. Isothermal calcination of starting binary dihydrogenphosphate was carried out in electric oven at various temperatures. The reaction intermediates and products obtained were analyzed by instrumental analytical methods and extraction experiments with solutions of inorganic compounds and with organic reagents. Effect of water vapour pressure has been followed on course, rate and yield of the condensation reactions and of the formation of main considered product-binary cyclo-tetraphosphate (tetrametaphosphate)c-CoCaP4O12.

Restricted access