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The increasing amount of poly(ethylene terephthalate) (PET) waste is a worldwide problem which has induced requirements for its recycling and reusing. PET fibres have been used as a dispersed micro-reinforcement in a cementitious matrix. The microreinforcement in the fibre reinforced concrete absorbs tensile strain and prevents formation of microcracks originating from concrete shrinkage. The present work has been aimed at studying the effects of aging PET fibres by alkali hydrolysis and temperature cycles on the ...

Fluorine as one of the most abundant trace elements in coals is released into the air by combustion and pyrolysis of coal. The produced fluorine gaseous compounds, particularly hydrogen fluoride, are harmful due to their toxicity to living organisms and as a source of corrosion of metallic and ceramic materials. Reliable determination of generally very low concentrations of fluorine in coal (ten to hundred ppm level) is difficult. Standard analytical methods require tedious procedures for sample decomposition and ...

Continental intraplate magmatism commonly leads to formation of subvolcanic complexes, for which it is important to characterize their mantle sources. It is necessary to distinguish between the effects on the mantle signature of fractional crystallization and the assimilation processes during magma ascent and its residence in the crust before the final emplacement. Elucidation of these processes requires besides information on Sr and Nd isotopic ratios also detailed geochemical data, especially information on conc...

The study has been aimed at development of cheap sorbents of toxic heavy metals and radionuclides based on low rank, low energetic coals in combination with chitosan for use in treatment of both waste and drinking water and construction of active geochemical barriers. Sorbents based on lignite and naturally oxidized lignite (oxihumolite, leonardite) were prepared, both raw and impregnated with chitosan from its solution in oxalic acid. The sorbents were characterized by chemical and structural analyses. Their sorp...