Relationships between Fluid Intelligence and Executive Functions

In our recent study we investigated the relationship between fluid reasoning ability and prefrontal neocortex functions (spatial working memory and spatial planning). Fluid intelligence was assessed by using КАВС‑II test. Prefrontal neocortex functions were assessed by CANTAB computer test. Sixty normotypical Russian children (32 boys and 28 girls) participated in this study. Our results demonstrate, that two subtests which constitute the Fluid intelligence scale have different correlations with prefrontal functions. Main contribution to the relation between fluid reasoning and working memory was made by Story Completion subtest. Also, we found that there were no relations between fluid reasoning and spatial planning.The study was supported by the Russian Foundation for Basic Research, project № 18-013-01179

Temperature sensitive polymers as efficient and selective flotation collectors

Poly (N-isopropylacrylamide) (PNIPAM) is a temperature responsive polymer that undergoes changes from water soluble hydrophilic molecules to water insoluble hydrophobic colloids at temperatures below and above its lower critical solution temperature (LCST) of 32°C. It has been comprehensively demonstrated that PNIPAM is an effective flocculant, causing the formation of particle aggregates by means of hydrophobic attraction. It has also been demonstrated that PNIPAM has potential to act as a collector in a flotation system. As such, it is potentially suitable for the use in ultrafine flotation systems, which require selective formation of hydrophobic particle aggregates. This study investigates both the efficacy and selectivity of PNIPAM as a flotation collector. This is achieved by investigating the effect of charged PNIPAM polymers on the probability of particle/ bubble attachment of quartz and alumina particles respectively, where the probability of attachment is estimated using induction time measurements. The study also examines the effect of charged PNIPAM polymers on the selective floatability of quartz and alumina particles in a microflotaiton system. The results of this study showed that charged poly(N-isopropylacrylamide) polymers selectively increased both the probability particle/bubble attachment as well as the floatability of mineral particles. These results provide a basis for considering PNIPAM as both an effective and selective collector in a flotation system. Coupled with previous studies that demonstrate the efficacy of PNIPAM as a flocculant in mineral suspensions, these results clearly demonstrate the potential use of PNIPAM as a dual function reagent which acts as both selective flotation collector and flocculant in the flotation of ultrafine particles

Precipitation of dodecyl amine in KCl-NaCl saturated brine and attachment of amine particles to KCl and NaCl surfaces

Long-chain amines, used in potash ore flotation as collectors, are insoluble in NaCl-KCl saturated brine. In commercial applications. these amines are melted at 70-90 degrees C, dispersed in acidic solution of hydrochloric or acetic acids, and such emulsions are then introduced to the flotation pulp.To model the commercial potash ore flotation process, dodecyl amine, used in this study, was melted at 70 degrees C, dispersed in hydrochloric acid aqueous solution and was added to a KCl-NaCl saturated brine at room temperature. This results in the precipitation of the amine. The present study summarizes the influence of the conditions on the particle size and morphology of the precipitating amine particles. Methyl isobutyl carbinol (MIBC), common frother in flotation processes, was shown to affect amine dispersion when added into a hot amine emulsion prior to mixing with a saturated brine. This study demonstrates that the precipitating amine particles are selectively abstracted by KCl particles, but not by NaCl particles. (C) 2009 Elsevier B.V. All rights reserved

Presence of negative charge on the basal planes of New York talc

Potentiometric titration measurements as well as rheological measurements of talc aqueous suspensions indicate that the behavior of the New York talc particles is consistent with the presence of a negative charge on their basal planes. The possibility of the presence of a negative electrical charge on the basal planes of talc particles is analyzed in this paper. Samples of New York talc were studied using electron microprobe analysis and dehydration techniques and the exact chemical formula of New York talc was determined. It was found that there exists a deficiency of protons in the tetrahedral layers of talc, resulting from substitution of Si4+ ions with Al3+ and Ti3+ ions. The comparison of the level of substitution of Si4+ ions with ions of a lower valency was found to be of a similar order of magnitude as that found in other talc deposits. This strongly points to the presence of a negative charge on the talc basal plane