Combined effect of viscous dissipation and joule heating on the coupling of conduction and free convection along a vertical flat plate

An analysis is presented to investigate the influences of viscous dissipation and Joule heating in the entire thermo-fluid dynamic field resulting from the coupling of bouncy forced flow with conduction along one side of a heated flat plate of thickness ‘b’. The governing equations are transformed into dimensionless non-similar equations by using set of suitable transformations and solved numerically by the finite difference method along with Newton's linearization approximation. Numerical results for the velocity profiles, temperature profiles, skin friction coefficient and the surface temperature distributions are shown both on graphs and in tabular form for different values of the parameters.     

Solid State Bioconversion of Oil Palm Empty Fruit Bunches for Production of Citric Acid by Wild Strains of Aspergillus Niger

This study investigated the potential of Aspergillus niger strains for the production of citric acid from oil palm empty fruit bunches (EFB) through solid state bioconversion (SSB). Twenty six wild strains of Aspergillus niger isolated from lemon, orange, and sewage treatment plant sludge were evaluated. Factors considered in the study were citric acid production, sugar consumption, and protein content as growth indicator. Two strains of Aspergillus niger (IBO-103MNB) and (IBO-114MNB) were found to have good potential with citric acid production of 128.43 ± 6.3 and 140.50 ± 1 g kg^-1 of dry EFB with bioconversion time of 4 and 8 d, respectively. The productivity of citric acid by these strains was found to be 32 and 17.5 g kg^–1d^–1, respectively.