Modelling of bio-oil yield from fast pyrolysis of sawdust

Bio-oil has received great attention due to the environmental concerns associated with the usage of fossil fuels and the predicted inability of these fuels to cope with future increases in energy demands. In this work an existing kinetic model equation has been modified using polynomial equations in conjunction with experimental data for six different sawdust types using the least squares method. The existing Model was modified with a linear equation (Model B), quadratic equation (Model C), and also by a cubic equation (Model D). The new models for bio-oil yield predictions obtained from the sawdust types show very low average errors of 1.2% - 4.4% compared to the experimental results and high correlation coefficients in the range 0.95 - 0.99 attesting to their reliability. Model C has been found to be the best for the spruce sawdust while Model D is the best for other sawdust types mentioned.Keywords: Modeling, Bio-oil yield, Sawdust, Fast PyrolysisNigerian Journal of Technological Researc

Evidence for the shikimate pathway in apicomplexan parasites

Parasites of the phylum Apicomplexa cause substantial morbidity, mortality and economic losses, and new medicines to treat them are needed urgently. The shikimate pathway is an attractive target for herbicides and antimicrobial agents because it is essential in algae, higher plants, bacteria and fungi, but absent from mammals. Here we present biochemical, genetic and chemotherapeutic evidence for the presence of enzymes of the shikimate pathway in apicomplexan parasites. In vitro growth of Toxoplasma gondii, Plasmodium falciparum (malaria) and Cryptosporidium parvum was inhibited by the herbicide glyphosate, a well-characterized inhibitor of the shikimate pathway enzyme 5-enolpyruvyl shikimate 3-phosphate synthase. This effect on T. gondii and P. falciparum was reversed by treatment with p-aminobenzoate, which suggests that the shikimate pathway supplies folate precursors for their growth. Glyphosate in combination with pyrimethamine limited T. gondii infection in mice. Four shikimate pathway enzymes were detected in extracts of T. gondii and glyphosate inhibited 5-enolpyruvyl shikimate 3-phosphate synthase activity. Genes encoding chorismate synthase, the final shikimate pathway enzyme, were cloned from T. gondii and P. falciparum. This discovery of a functional shikimate pathway in apicomplexan parasites provides several targets for the development of new antiparasite agents