We give a simple demonstration of the formula relating the glass transition temperature, Tg, to the molar concentration x of a modifier in two types of glasses: binary glasses, whose composition can be denoted by XnYm+xMpYq, with X an element of III-rd or IV -th group (e.g. B, or Si, Ge), while MpYq is an alkali oxide or chalcogenide; next, the network glasses of the type Ax B1−x, e.g. Gex Se1−...

Background: A pot experiment was conducted to determine the toxic effects of some heavy metals on the plant growth and seed yield of maize (Zea mays L.). Materials and Metheds: Heavy metals Mn, Pb, Cd, Cr and Co individually and in combinations were added as chloride salts in solutions to the pots before sowing. The test plants for were harvested after 80 days of germination and evaluated f...

Denitrification is one of the most important soil microbial processes leading to the production of nitrous oxide (N2O). The potential changes with metal pollution in soil microbial community for N2O production and reduction are not well addressed. In this study, topsoil samples were collected both from polluted and non-polluted rice paddy fields and denitrifier communities were characterized wi...

Densification of oxide glasses at the glass transition offers a novel route to develop bulk glasses with tailored properties for emerging applications. Such densification can be achieved in the technologically relevant pressure regime of up to ~1 GPa. However, the present understanding of the composition–structure–property relationships governing these glasses is limited, with key questions, e....

The aim of this study was to determine the possibility of using feathers of blue tit nestlings to assess the level of endogenous accumulation of lead. For this purpose we conducted an experiment with lead application to randomly chosen nestlings from eight randomly drawn broods. Five days after the exposure, feathers of lead-treated nestlings had significantly higher lead concentrations than co...

algae have been proven efficient biological vectors for heavy metal uptake. in order to further study their biosorption potential, two strains spirogyra sp. and spirulina sp. have been studied under different initial metal concentrations. in recent years, the biosorption processes have been studied extensively using microbial biomass as biosorbent for heavy metal ions removal. in these studies,...

This study is one of very few dealing with the distribution and the origin of heavy metals in French soils from a priori non-polluted forest areas. The abundance of heavy metals measured in these soils decreases as follows: Cr>Zn>Pb>Ni>Cu>Co>>Cd. Total concentrations of Pb, Cr and Ni in some soils exceed the European thresholds for non-polluted soils and even the French association of normaliza...

Establishing the composition–structure–property relationships for amorphous materials is critical many important natural and engineering processes, including dissolution of highly complex volcanic glasses. In this investigation, we performed force field molecular dynamics (MD) simulations to generate detailed structural representations 10 CaO–MgO–Al2O3–SiO2–TiO2–FeO–Fe2O3–Na2O–K2O glasses with ...