Flow investigation in an industrial-scale soaker using radiotracer technique.

Flow dynamics of heavy petroleum residue in an industrial-scale soaker operating in a petroleum refinery was investigated. Residence time distributions (RTDs) of the residue were measured using radiotracer technique. Bromine-82 as dibromobiphenyl was used as radiotracer for tracing the petroleum residue. The measured RTDs were treated and mean residence times (MRTs) were determined. The measured RTD data was simulated using a combined model i.e. axial dispersion model in parallel with tanks-in-series with stagnant volume and exchange. The results of the model simulation fitted very well to the experimentally measured data and identified bypassing or existence two parallel flow paths within the soaker.

In vitro propagation of Mussaenda erythrophylla Schum and Thom cv. scarlet through multiple shoot regeneration.

Axillary bud explants were induced to form shoots on Murashige and Skoog's (MS)' basal medium. Best yield (9 shoots per explant) was obtained when the medium was supplemented with adenine sulphate (40 mg/L) and 6-benzylaminopurine (2.25 mg/L). The shoots were rooted on half strength MS basal medium supplemented with indole butyric acid (0.5 mg/L) and having thiamin-HCl (800 mg/L). Regenerated plantlets were successfully acclimatized. This is the first report of micropropagation in the genus Mussaenda without callus intervention.