Essential oils from the leaves of six medicinal palnts of Nigeria

The chemistry of Cassia siamea L., C. occidentalis L. (Fabaceae), Cnestis ferruginea Vahl ex DC (Connaraceae), Anthocleista djalonensis A. Chev (Loganiaceae), Solanum torvum Swartz and S. erianthum G. Don (Solanaceae) volatiles grown in Nigeria have been studied. The essential oils were obtained by hydrodistillation and analyzed by GC and GC-MS. The main compounds of C. siamea were (E)-geranyl acetone (5.8%), 1-octen-3-ol (5.8%), linalool (7.8%), iso-italicene (15.4%) and (E)-β-damascenone (11.0%). On the other hand, C. occidentalis consisted mainly of (E)-geranyl acetone (8.0%), hexahydrofarnesylacetone (24.0%) and (E)-phytol acetate (40.7%). The oil of C. ferruginea was comprised mainly of (E)-geranyl acetone (13.7%), (E)-α-ionone (9.5%), phytol (5.8%), pentadecanal (6.1%) and 1-octen-3-ol (5.5%). The main compounds of A. djalonensis were α-humulene (31.9%), β-caryophyllene (17.8%), humulene epoxide II (12.7%) and caryophyllene oxide (5.9%). The main volatiles of S. torvum were (E)-phytol acetate (38.7%), pentadecanal (25.3%) and (E)-geranyl acetone (5.0%). Apart from methyl salicylate (4.5%), tetradecanal (2.2%), 2-pentyl furan (1.8%), hexahydrofarnesylacetone (1.6%) and hexadecanal (1.1%), all other compounds were either present in trace quantity or in amounts less than 1%. On the other hand, α-humulene (46.6%) and β-caryophyllene (20.6%) were the compounds occurring in higher quantities in S. erianthum. The volatile oil contents of Cassia siamea, Cnestis ferruginea, Anthocleista djalonensis and Solanum torvum are being reported for the first tim

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No Abstract. Ghana Library Journal Vol. 20 (1) 2008: pp. 15-3

The effect of A5TB refiner on the fatigue strength of 6063AL alloy

The study focuses on the influence of aluminium titanium boron (A5TB) master alloy on the fatigue behaviour of 6063Al alloy. Cylindrical cast rods of 6063Al alloy containing different proportions of A5TB ranging from 0 - 0.11 wt.% were produced and were machined to conform to a standard fatigue specimen. The test specimens prepared were tested for fatigue strength at various stress levels, and results obtained were compared. The resistance to fatigue failure was observed to decrease as the stress level increased. It was also noted that irrespective of stress level, the optimum fatigue strength was obtained when the A5TB content was about 0.06 wt.%. It was found that 6063Al alloy to which A5TB master alloy have been added was most suitable for the design of components meant to operate under cyclic loading at low stresses below about 3.02 kN/m2.Keywords: Refiner, Fatigue, Aluminium Alloy, Cyclic Loading, Stress levelJournal of Applied Science, Engineering and Technology, Volume 1