Volume 3 Issue 3
Authors: J. A. Nwaoga
Abstract: Mimosa pudica is now found to be a raw material for making photovoltaic cells capable of transforming solar radiation (energy) into electrical energy. Mimosa pudica is a medicinal plant of African origin. A local weed grows and thrives in the tropics. This plant belongs to the family: Fabacae, Genus: mimosa, Species: pudica, common name: mimosa, sensitive plant. It has physical features characterized by its ability to close the leaves when touched, the leaves open at sunrise, and then fold at sunset. The obvious control by the sun and photovoltaic response by the live Mimosa stimulated the interest to embark on the research. The Mimosa pudica solar cell electricity generation booster has been isolated using a profiled component leaf extract. This was done by using electrolytic process to separate the black silicon identified in the phytochemical analysis of the mimosa leaf extract. The isolates identified as black silicon, the thiosulfate and chloroplast as a composite is placed on a thin film PVC substrate. This produced a profound synergistic action in solar electricity generation. The addition of the crystalline black silicon to the composite slightly increased the transformation efficiency of the solar energy conversion. The microwave oven assisted the acid digestion of Mimosa pudica leaves with the resultant extraction of silica deposits. When the black silicon was added to the thiosulfate and chloroplast moieties, result showed graded shift in the transformation from 2-5%, thus raising the transformation efficiency from the usual current output of 250milliamps to 500milliamps, 6V DC output. The renewal time in the thin film coating was remarkable due to Nano particles of the black silicon providing increased surface area and the leaching effect of the thiosulfate which lead to expanded absorption spectra for solar activity. The finding is an improvement on the earlier demonstrated chlorophyll, thio-sulfate oxidation-reduction action resulting in electricity generation by Mimosa pudica solar cell accumulators.
Keywords: Solar Energy; Electricity; Black Silicon; Photovoltaic Cell; Mimosa Pudica; Transformation; Efficiency
Authors: Felix Rosas; Alexis Maldonado; Jehilys V. Salazar; Humberto Soscun; Marcos Loro?o; José R. Mora; Tania Cordova; Gabriel Chuchani
Abstract: The mechanism of the thermal decomposition of oxetan-2-one (β-propiolactone) and 4-methyl-oxetan-2-one (β-butyrolactone) in the gas-phase has been revisited through the electronic structure calculations using B3LYP, B3PW91, MPW1PW91, PBEPBE, PBE1PBE, CAMB3LYP, and MP2, with basis sets 6-31G(d), 6-31G(d,p), 6-31++G(d,p), 6-311G(d,p), 6-311++G(d,p). The authors found better agreement between experimental and calculated parameters when using MWP1PW91 functional. The B3LYP functional gave lower energies of activation with errors over15 kJ/mol for oxetan-2-one and 4-methyl-oxetan-2-one. The reactions are unimolecular and proceed through a concerted–polar four-centered transition states. The presence of a methyl group in 4-methyl-oxetan-2-one lowers significantly the energy of activation, facilitating the thermal decomposition by stabilizing the transition state. The polarization of the RHC+—O - (R= H or CH3) was rate determining for these reactions. The predominant advance of the RHC+—O - bond breaking in the transition state, confers intimate ion pair character. The reactions are described as unimolecular concerted non-synchronous process.
Keywords: Ab Initio and DFT Calculations; Thermal Decomposition; Oxetan-2-one; 4-Methyl-oxetan-2-one; Mechanism