Processing of Ogbolokuta limestone through calcination technique for quicklime production

Report on processing of Ogbolokuta limestone through calcination technique for quicklime production is presented. The limestone was washed to remove impurities, dried, ground in to powder form and classified with the aid of the automatic vibrating sieves of 80mm, 90mm, 100mm, 300mm and 425mm. X-ray fluorescence spectroscopy was used to determine the chemical compositions of the limestone, while its mineralogical composition was determined by X-ray diffractometer. Scanning electron microscope was used to study the surface morphology of the sample. Sample size area was grossly estimated by Langmuir method, while density functional theory was used to obtain different pore structural morphology of the sample. Analyses of the results showed that CaO (65.7%) is the predominant chemical constituent, and calcite is the main mineral of the limestone. Quicklime was successfully produced from Ogbolokuta limestone through calcination process. Calcination of the limestone enhanced its surface morphology. The quicklime yield was temperature, particle size and time dependent.

Phosphatidylcholine — Mg2+ equilibria in a monolayer at the air/water interface

Abstract The interaction between Mg2+ and a phosphatidylcholine (lecithin, L) monolayer at the air/water interface was investigated. Surface tension measurements (Langmuir method) of phosphatidylcholine monolayers as a function of Mg2+ concentration were carried out at 22°C using a Teflon trough and a Nima 9000 tensiometer. Interactions between phosphatidylcholine and Mg2+ result in significant deviations from additivity. An equilibrium theory was developed to obtain the stability constants and areas occupied by one molecule of LMg+ and L2Mg. The stability constants were K 1 = 9.95×102 m2 mol−1 and K 2 = 3.87×104 m2 mol−1. The area occupied by LMg+ is 77 Å2 molecule−1, while that occupied by L2Mg is 109 Å2 molecule−1. The Gibbs free energies of complexation for LMg+ and L2Mg are −16.91 ± 0.51 and −25.88 ± 0.76 kJ mol−1. Graphical abstract

Influence of Temperature on Phytohormone Interactions with Monolayers Obtained from Phospholipids of Wheat Calli

The effect of temperatures (15 and 5 °C) on adsorption parameters of phytohormones at monolayers prepared from a mixture of phospholipids extracted from non-embryogenic (NE) and embryogenic (E) winter wheat calli initiated from inflorescences (inf) and embryos (emb) was studied. The surface parameter values, i.e. limiting area and collapse pressure, were determined using the Langmuir method. Phytohormones 2,4-dichlorophenoxyacetic acid (2,4-D), indole-3-acetic acid (IAA), kinetin, zeatin and zearalenone were investigated. The phytohormones, at a concentration of 0.2 μg/ml dissolved in water, were injected into the subphase. Phospholipids, at the concentration of 2 mg/ml, were spread at the water surface and the monolayer was compressed. The anomalous temperature effect was observed, especially, in non-embryogenic systems. In monolayers obtained from E phospholipids, the temperature effect was dependent on the kind of tissue from which the callus was initiated. Among all the examined phytohormones, the greatest changes (monolayer expansion) were found for IAA and zearalenone. However, this activity depended strongly on the kind of tissue from which the phospholipid mixture was extracted.