kinetics

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).

The Fe3O4 nanoparticles dissolution in the acid media (pH = 1.8–5.0; 3 h) has been studied. The kinetic curves have been obtained and Fe3О4 solubility has been determined using spectrochemical, gravimetric and atomic absorption methods. Fe3О4 solubility was found to be increased with the increase in inorganic media acidity and the time. By means of SEM, XRD and NMR analyses the effect of acidic media on the physico-chemical properties of Fe3О4 particles surface has been determined.

The statics and kinetics of albumin adsorption on natural zeolite of clinoptilolite structure have been investigated. The basic characteristics of zeolite have been determined. The method of albumin in a solution analysis was given. An isotherm of albumin adsorption was plotted and the Langmuir equation describing this isotherm was given. The presence of an external and pore diffusion adsorption mechanism has been experimentally established during the study of kinetics in a machine with mechanical stirring.

This research presents that the higher temperature results on higher extracted anthocyanin. In addition, it was found that pH 2 was preferable for obtaining greater anthocyanin content. Employing the second-order kinetics model in this research confirmed the good fitting of the model and experimental data.

The study examined the physico-chemical characteristics and combustion kinetics of petroleum coke or petcoke (PCK). The results revealed that PCK contains significantly high carbon, fixed carbon, and calorific value with low sulphur, and ash content. The combustion characteristics of PCK revealed the temperatures of ignition ranged from 764 to 795 K; peak decomposition from 808 to 875 K and burn-out from 857 to 933 K. The combustion performance and reactivity analyses were examined based on the ignition ratio, devolatilization ratio, burnout ratio, and combustion characteristic factor.

The influence of cavitation on a decrease of the number of microorganism colonies has been investigated. Our results have shown that the number of viable microorganisms in water dispersion during first 30 minutes of sonication increased till maximum. Then their quantity sharply decreased. A kinetic model of ultrasonic degradation of yeast cells aggregates was proposed.

The structure of an emulsion formed in wastewater from edible oils production has been investigated. The type of emulsifier has been determined and the method of emulsion destruction has been proposed, providing further quality treatment of wastewater via liquid-extraction method. The resulting equilibrium and operating lines of the process were received. The number of transfer stages has been determined. The mathematical model of liquid-extraction wastewater treatment was built.

Extraction of glucomannan from crude porang flour by acid hydrolysis and ethanol precipitation was studied. Effects of acid concentration, temperatures and time were investigated, kinetics model of the process was developed and the parameters were evaluated based on experimental data. New data on yield and purity of glucomannan under various conditions were obtained.

The series of reactive peroxide macroinitiators (RC) based on acryl amide (AcAm), butyl methacrylate (BMA), maleic anhydride (MA) and peroxidic monomer 5-ter-butylperoxy-5-methyl-1-hexene-3-yne (PM), which can be used for biocompatible polymer cross-linking, were synthesized via radical copolymerization in organic solvent.