ABSTRACT
Melaleuca cajuputi essential oil in aerosol spray was evaluated against the dengue vectors Aedes aegypti andAe. Albopictus at low cost housing flats in Section 10, Setapak, Kuala Lumpur, Malaysia. Essential oil in aerosol viz: 5% and 10% of concentrations were sprayed for 5 seconds each towards hung mosquitoes in 5 cylindrical net cages. Aerosol weights were recorded before and after spraying to determine discharge rates. Knockdown and mortality number were observed and compared to MS standard aerosol which contain 0.07% prallethrin and 0.05% d-phenothrin as positive control and aerosol contain 40% kerosene and 60% LPG was used as negative control. High knockdown and mortality was observed in both species of mosquitoes towards MS standard aerosol. There was a significant difference [P < 0.05] of mortality and knockdown between 5% and 10% of essential oil aerosol and 5% and 10% essential oil between MS standard. For 5% essential oil, mean percentage [%] of knockdown and mortality of Ae. Aegypti displayed slightly higher compared to Ae. albopictus. Spraying with 5% M. cajuputi essential oil aerosol indicated a knockdown of Ae. Aegypti 5.60 +/- 1.18 and mortality of 22.90 +/- 4.22 while Ae. albopictus showed 4.60 +/- 0.89 knockdown and 20.00 +/- 2.85 mortality. The 10% essential oil concentration gave 23.60 +/- 1.68 knockdown and 48.05 +/- 0.37 mortality for Ae. aegypti. Ae. Albopictus gave 23.00 +/- 3.16 knockdown and 44.20 +/- 2.10 mortality respectively. Extracts of essential oils does possessed an adulticidal effects and could be considered and utilized for future dengue vectors control
ABSTRACT
Poly (p-phenylene vinylene) (PPV) was synthesized from p-xylylene bis(tetrahydrothiophenium chloride) using the Wessling route and characterized by Fourier Transform Infra-Red (FTIR) and UV-visible (UV-VIS) spectroscopic techniques. The significance of thermal treatment along with evolution of precursor polymer to polymer PPV was also studied through these spectroscopic techniques. Thermally Stimulated Current (TSC) measurements indicated the presence of crystallization, sulphonium group which occurred through the evolution from precursor polymer to polymer PPV during thermal treatment.