кінетика

The dissolution process of potassium chloride particles in the apparatus with two-blade mechanical stirrer was investigated and the mass transfer coefficient was determined. The experimental results were generalized by criterion dependence. The independence of the mass transfer coefficient from the solid particles diameter was confirmed. A countercurrent process of potassium salt dissolution in two apparatuses with a mechanical stirring was considered. A mathematical model for countercurrent dissolution was developed and the efficiency of this process was determined.

The process of paraffin formation has been considered, including the peculiarities of the paraffin structure as a result of phase transitions with a decreasing temperature. Mathematical models for thermodynamic and kinetic calculations of the "solid-liquid" system phase equilibrium have been developed. To shift the "fuel oil-paraffin" balance towards the liquid, it is necessary to reduce the activity ratio of solid and liquid phases by introducing into the system a substance with a lower solubility parameter.

This study investigates the capability of Thuja occidentalis leaves carbon powder (TOLC) as a viable adsorbent for the expulsion of chromium(VI) from aqueous solutions. By batch mode, the removal percentage of Cr(VI) is observed to be pH perceptive and furthermore relies upon the time of equilibration, amount of the TOLC adsorbent and Cr(VI) concentration. TOLC adsorbent before and after adsorption of Cr(VI) was characterized with FTIR, SEM and EDX. Adsorption isotherm results divulge that the Langmuir model was a better fit.

The results of experimental studies of the peculiarities of metallization of granular polyethylene are presented. The influence of concentration factors on the metallization process of zinc-activated polyethylene granules of brand Liten PL-10 was investigated. It is established that by changing the concentration of copper sulfate and sodium hydroxide, as well as the degree of loading of polymeric raw materials, it is possible to effectively regulate the amount of recovered copper on granules of polyethylene, and therefore the thickness of the metal layer formed on them.

The kinetics of polymerization of 2-hydroxyethyl methacrylate with polyvinylpyrrolidone in a thin layer were studied. The dependences of the conversion for polymerization HEMA with PVP in mass and in solvent were determined. (Co)polymerization exotherms for the reaction in mass were calculated. The reaction order by initiator, monomer and polymer was determined and the mathematical dependence of the total rate of grafted copolymerization of HEMA to PVP was calculated.

The experimental investigation of the solubility of the prolonged-action nitroamophos obtained with the use of modified polyethylene terephthalate (PET) waste is presented. The kinetic coefficients of the diffusion process of the substances inside the shell are determined. The possibility of applying a theoretical model to predict the agro-ecological properties of encapsulated ammonium nitrate phosphate is demonstrated.

The influence of microwave radiation on the rate of СО2 uptake by chlorophyll-producing microalgae of the Chlorella Vulgaris has been established. Experimental dependencies of greenhouse gases absorption by microalgae depending on the impact of microwave electromagnetic (MEM) field have been obtained. The mathematical model of the dynamics of biomass growth of Chlorella Vulgaris microalgae depending on the time of electromagnetic radiation has been constructed.

The present paper deals with the kinetic and mechanistic investigation of Os(VIII) catalyzed oxidation of 2-pyrrolidinecarboxylic acid by sodium periodate (NaIO4) in alkaline medium in the temperature range of 303‒318 K. The experimental result shows a first order kinetics with respect to Os(VIII) and periodate while positive effect with respect to substrate i.e., 2-pyrrolidinecarboxylic acid was observed. The reaction showed negative effect for [OH-]. Negligible effect of Hg(OAc)2 and ionic strength of the medium was observed.

The catalytic effect of ruthenium chloride on the outer sphere electron transfer of hexacyanoferrate(II) by periodate ion in aqueous alkaline medium has been effectively employed to determine ruthenium(III) at micro level. The optimum reaction condition has been established and fixed time procedure is adopted. A linear relationship between changes in absorbance and added Ru(III) concentration has been utilized for the trace level determination of Ru(III).