Papers by Kasthuri Kumaran
Journal of Building Physics, 2004
The Boltzmann transformation method is used to determine the liquid water diffusivity from moistu... more The Boltzmann transformation method is used to determine the liquid water diffusivity from moisture content profiles as measured in a capillary water absorption experiment. An inter-laboratory comparison for analyzing the reliability of the determination method showed that the inaccuracy in the liquid water diffusivity is caused by scatter in the transformed data and by uncertainty in the boundary conditions at the intake surface and ahead of the steep moisture front. A methodology is proposed based on (1) the evaluation of the validity of the diffusion approach, (2) a simplified handling of the boundary conditions, (3) smoothing of the scattered data and (4) the evaluation of the quality of the determined liquid water diffusivity. For HAM (Heat-Air-Moisture transport) calculations values of the liquid water diffusivity for moisture contents higher than the capillary moisture content are disregarded. The liquid water diffusivity can be described by an exponential function limited at a lower moisture content bound.
Water, Air, & Soil Pollution, 2012
Staphylococcus cohnii ssp. was found to produce a bioflocculant with high flocculating activity f... more Staphylococcus cohnii ssp. was found to produce a bioflocculant with high flocculating activity for kaolin suspension. Using optimized culture conditions, a flocculating activity of 70.3 % at a bioflocculation concentration of 0.3 mg/L at pH 7 with Ca 2+ as the cation and 88.9 % in 1.2 mg/L of bioflocculant concentration for Al 3+ as the cation was obtained for bacteria that were incubated at temperature of 40°C for 2-day incubation period. It was found to be effective for flocculation of a kaolin suspension over weakly acidic pH (6-8); divalent and trivalent (Ca 2+ and Al 3+ ) enhanced the flocculating activity. This bioflocculant possesses a good flocculating activity, which can be promoted by the addition of trivalent and bivalent cations in kaolin suspension.
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Papers by Kasthuri Kumaran