Amit Kumar

The optical and electronic properties of thin films of the solution-processible polymer poly-(CH(3))(3)Si-cyclooctatetraene are presented. This conjugated polymer is based on a polyacetylene backbone with (CH(3))(3)Si side groups. Thin transparent films have been cast onto n-doped silicon (n-Si) substrates and doped with iodine to form surfacebarrier solar cells. The devices produce photovoltages that are at the theoretical limit and that are much greater than can be obtained from n-Si contacts with conventional metals. Two methods for forming layered polymeric materials, one involving the spincoating of preformed polymers and the other comprising the sequential polymerization of different monomers, are also described. An organic polymer analog of a metal/insulator/metal capacitor has been constructed with the latter method.

Abstract BACKGROUND: In the presence of light, micro‐algae convert CO 2 and nutrients to biomass that can be used as a biofuel. In closed photo‐bioreactors, however, light and CO 2 availability often limit algae production and can be difficult to control using traditional diffuser systems. In this research, a hollow fiber membrane photo‐bioreactor (HFMPB) was investigated to: (1) increase the interfacial contact area available for gas transfer, (2) treat high nutrient strength (412 mg NO 3 − ‐N L −1 ) wastewater, and (3) produce algal biomass that can be used as a biofuel. RESULTS: A bench scale HFMPB was inoculated with Spirulina platensis and operated with a 2‐15% CO 2 supply. A mass transfer model was developed and found to be a good tool to estimate CO 2 mass transfer coefficients at varying liquid velocities. Overall mass transfer coefficients were 1.8 × 10 −6 , 2.8 × 10 −6 , 5.6 × 10 −6 m s −1 at Reynolds numbers of 38, 63, and 138, respectively. A maximum CO 2 removal efficiency of 85% was observed at an inlet CO 2 concentration of 2% and a gas residence time (membrane‐lumen) of 8.6 s. The corresponding algal biomass concentrations and NO 3 removal efficiencies were 2131 mg L −1 and 68%, respectively. CONCLUSION: The results show that the combination of CO 2 sequestration, wastewater treatment and biofuel production in an HFMPB is a promising alternative for greenhouse gas mitigation. Copyright © 2010 Society of Chemical Industry

ergy products such as bio-ethanol, 1-butanol, bio-methane, bio-hydrogen, organic acids including citric acid, succinic acid and lactic acid, microbial polysaccharides, single cell protein and xylitol. The biotechnological aspect of bio-transformation of lignocelluloses research and its future prospects are also discussed.