Demulsification of water-in-bitumen emulsion was studied using 52 nonionic surfactants of different chemical families. Relative solubility number (RSN) and molecular weight were determined for these demulsifiers. Their dewatering performance was evaluated by determining the rate of water separation during gravitational settling and centrifugation. The results indicated that there is no overall correlation between demulsification performance and RSN value. However, within a given surfactant family, such as polymerized polyols, oxyalkylated alkylphenol formadehyde resins, and oxyalkylated alkyl resins, the degree of demulsification was found to correlate with the RSN value. A maximum of dewatering performance was observed in a specific RSN range for two surfactant families. Molecular weight also showed a significant effect on demulsification performance. Surfactants with low molecular weight (<4000) did not break the emulsion in dosages of 300−400 ppm regardless of RSN value. For the water-in-bitumen emulsion studied in this work, the most effective demulsifiers are those with RSN values between 7.5 and 12.5 and molecular weights between 7500 and 15000.

(E)-6,10-dimethyl-5,9-undecadien-2-ol (geranyl acetol), termed here fuscol, was identified as a male-produced pheromone emitted by Tetropium fuscum (F.) and Tetropium cinnamopterum Kirby. In field experiments, traps baited with synthetic fuscol alone were not significantly attractive, but the combination of fuscol plus host volatiles (a synthetic blend of monoterpenes plus ethanol) attracted significantly more male and female T. fuscum and female T. cinnamopterum than did host volatiles alone. This is the first homoterpenoid alcohol to be described in the Cerambycidae, and the first pheromone reported from the sub-family Spondylidinae.

Analyses of the elytral hydrocarbons from male and female emerald ash borer, Agrilus planipennis Fairmaire, that were freshly emerged vs. sexually mature (>10 days old) revealed a female-specific compound, 9-methyl-pentacosane (9-Me-C(25)), only present in sexually mature females. This material was synthesized by the Wittig reaction of 2-decanone with (n-hexadecyl)-triphenylphosphonium bromide followed by catalytic reduction to yield racemic 9-Me C(25), which matched the natural compound by gas chromatography/mass spectrometry (retention time and EI mass spectrum). In field bioassays with freeze-killed sexually mature A. planipennis females, feral males spent significantly more time in contact and attempting copulation with unwashed females than with females that had been washed in n-hexane to remove the cuticular lipids. Hexane-washed females to which 9-Me-C(25) had been reapplied elicited similar contact time and percentage of time attempting copulation as unwashed females, indicating that 9-methyl-pentacosane is a contact sex pheromone component of A. planipennis. This is the first contact sex pheromone identified in the Buprestidae.