In this study, series of non-ionic surfactants from Span and Tween are evaluated for their ability to affect the viscosity profile of cyclopentane hydrate slurry. The surfactants; Span 20, Span 40, Span 80, Tween 20, Tween 40 and Tween 80 were selected and tested to provide different hydrophilic-hydrophobic balance values and allow evaluation their solubility impact on hydrate formation and growth time. The study was performed by using a HAAKE ViscotesterTM 500 at 2 °C and a surfactant concentration ranging from 0.1 wt%-1 wt%. The solubility characteristic of the non-ionic surfactants changed the hydrate slurry in different ways with surfactants type and varying concentration. The rheological measurement suggested that oil-soluble Span surfactants was generally inhibitive to hydrate formation by extending the hydrate induction time. However, an opposite effect was observed for the Tween surfactants. On the other hand, both Span and Tween demonstrated promoting effect to accelerate hydrate growth time of cyclopentane hydrate formation. The average hydrate crystallization growth time of the blank sample was reduced by 86% and 68% by Tween and Span surfactants at 1 wt%, respectively. The findings in this study are useful to understand the rheological behavior of surfactants in hydrate slurry.
Hevea brasiliensis remains the primary crop commercially exploited to obtain latex, which is produced from the articulated secondary laticifer. Here, we described the transcriptional events related to jasmonic acid (JA)- and linolenic acid (LA)-induced secondary laticifer differentiation (SLD) in H. brasiliensis clone RRIM 600 based on RNA-seq approach. Histochemical approach proved that JA- and LA-treated samples resulted in SLD in H. brasiliensis when compared to ethephon and untreated control. RNA-seq data resulted in 86,614 unigenes, of which 2,664 genes were differentially expressed in JA and LA-induced secondary laticifer harvested from H. brasiliensis bark samples. Among these, 450 genes were unique to JA and LA as they were not differentially expressed in ethephon-treated samples compared with the untreated samples. Most transcription factors from the JA- and LA-specific dataset were classified under MYB, APETALA2/ethylene response factor (AP2/ERF), and basic-helix-loop-helix (bHLH) gene families that were involved in tissue developmental pathways, and we proposed that Bel5-GA2 oxidase 1-KNOTTED-like homeobox complex are likely involved in JA- and LA-induced SLD in H. brasiliensis. We also discovered alternative spliced transcripts, putative novel transcripts, and cis-natural antisense transcript pairs related to SLD event. This study has advanced understanding on the transcriptional regulatory network of SLD in H. brasiliensis.