Batch sorption experiments were performed for the removal of chromium(III) ions from aqueous solutions using Romanian Sphagnum moss peat (untreated and treated with NaCl solution) as sorbent. In order to establish the best conditions for the sorption of chromium(III), the influence of initial pH, contact time, peat dose and metal ion concentration was investigated. The Freundlich, Langmuir and ...

OBJECTIVE The aim of the study was to compare and evaluate the in vitro biodegradation of nickel and chromium from space maintainers, made of three different companies, i.e (Dantaurum, Rocky mountain and Dtech) in artificial saliva. MATERIALS AND METHODS The study comprised of 30 space maintainers out of which 10 were fabricated using Dantaurum, 10 using Rocky mountain and 10 using Dtech band...

OBJECTIVE To test the null hypothesis that the aging process in self-ligating brackets is not higher than in conventional brackets. METHODS Twenty-five conventional (GN-3M/Unitek; GE-GAC; VE-Aditek) and 25 self-ligating (SCs-3M/Unitek; INs-GAC; ECs-Aditek) metal brackets from three manufacturers (n = 150) were submitted to aging process in 0.9% NaCl solution at a constant temperature of 37 ± ...

crown ethers 12-crown-4 (12c4), benzo-15-crown-5 (b15c5), 18-crown-6 (18c6), nitrobenzo-18-crown-6 (nb18c6) dibenzo-18-crown-6 (db18c6) and dicyclohexyl-18-crown-6 (dc18c6), dissolved in dichloromethane, are able to form oxonium-ion complexes in contact with aqueous sulfuric and hydrochloric acid solutions. this ability allows the transfer of cr(vi) oxanions from the acid media, through an orga...

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,...

The pitch accuracy of a grating formed by laser-focused atomic deposition is evaluated from the point of view of fabricating nanoscale pitch standard artifacts. The average pitch obtained by the process, nominally half the laser wavelength, is simply traceable with small uncertainty to an atomic frequency and hence can be known with very high accuracy. An error budget is presented for a Cr on s...

30% of the chromium ore reserves in world are concentrated Kazakhstan, during processing which large volumes wastewater containing toxic salts, formed. Сhromium is one priority components both terms emission and toxicity (for Cr(VI), maximum permissible concentration 0.05 mg/l). The compounds (III) especially (VI) have a general toxic, allergenic, carcinogenic, mutagenic effect on human body, a...

The aim of this study was to evaluate the behavior of high-noble gold-platinum alloy samples (18 + 8 Rafinerija plemenitih kovina, Zagreb, Hrvatska), in a phosphate buffer pH 6.0. The aim of the study was to determine the type and amount of released metal ions from the alloy, and to evaluate how the time of exposure to the phosphate buffer pH 6.0 influences the release of metal ions from the al...