Central composite design methodology has been employed to model the sludge yield data obtained during liquid-liquid extractive rerefining of spent lubricants using an alcohol (1-butanol) and a ketone (methyl ethyl ketone) as prospective solvents. The study has resulted in two reasonably accurate multivariate process models that relate the sludge yield (R (2) = 0.9065 and 0.9072 for alcohol and ...

1. Hydrogen cyanide inhibited acetoacetate decarboxylase only when incubated with the enzyme in the presence of car-bony1 compounds. This resulted in an inhibitory synergism between hydrogen cyanide and carbonyl compounds. This synergism was used to investigate the comparative abilities of various carbonyl compounds to form Schiff’s bases at the active site of the enzyme. The order of effective...

In this research, new composite materials were improved by reinforcing the environment-polluting waste polyurethane (WPU) to unsaturated polyester (UP). Polyester composites produced with WPU, UP, methyl ethyl ketone peroxide (MEKP), and cobalt octoate (Co. Oc.). The effect of WPU on changes in density, Shore D hardness, thermal conductivity coefficient, stability, porosity obtained investigate...

Abstract Two solvent mixtures for high-performance thin-layer chromatographic (HPTLC) separation of some compounds showing estrogenic activity in the yeast estrogen screen (YES) assay are presented. The new method, planar (pYES) combines YES and a on silica gel HPTLC plates with performance assay. For separation, analytes were applied bandwise to (10 × 20 cm) fluorescent dye (Merck, Germany). d...

introduction soil herbicides residue in agroecosystems is one of the important problems due to herbicides application. however herbicides residue in soil extend the period of weed control. nevertheless, it may persist longer than desired and injure subsequent crops in rotation. herbicides vary in their potential to persist in the soil. some herbicides such as sulfonylurea herbicides are very pe...