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In the present work, two organic phase change materials (PCMs) are used to develop a new eutectic PCM for sharp melting point with high latent heat of fusion. Optimized eutectic can be suitable for a passive water heating system (PWHS). The binary eutectic PCMs consisting of different compositions of acetanilide and benzoic acid are prepared and optimized at a composition of 30:70 by weight percentage. Optimized samples are characterized by using differential scanning calorimetry (DSC), Fourier transform infrared spectrophotometry and field-emission scanning electron microscopy. The results of DSC showed that melting temperature and latent heat of the optimized eutectic PCM is found to be 75.56 • C and 193.56 J g −1. A negligible change in melting temperature and latent heat of fusion of the optimized eutectic based PCM after 100 accelerated heating and cooling cycles is observed. The prepared eutectic PCM is employed as a thermal energy storage (TES) system for PWHS. The experimental results of a eutectic PCM based TES system for the PWHS show that the use of eutectic helps in enhancing the maximum utility of solar energy during off-shine hours.

A digital computer program was written to refine and extend currently available fh/U: g tables for thermal process evaluation. Some characteristics of the resulting parameters are discussed and an error‐analysis is presented.

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Abstract:Cheap and efficient dye sensitized solar cells (DSSCs) can be prepared using natural dyes responding in visible region of solar spectrum. Localized surface Plasmon resonance (LSPR) plays a very important role for the improvement in the efficiency of DSSCs by using Plasmonic nanoparticles (PNPs) for exploiting the visible portion of the solar radiation by transferring the energy from dye to PNP. This energy transfer from dye to low cost semiconductor TiO 2 through PNP increases the overall photo catalytic activity. In the present study, natural and synthetic dyes are prepared and the optical transmittance and absorbance of the dyes are measured in the wavelength range of 250nm to 850nm using UV-Vis spectroscopy and they are used in DSSC. Natural dyes extracted from fruits and synthetic dye based on Ru metal complex is used as sensitizers. Photo Conversion Efficiency (PCE) of the solar cells utilizing different dyes are compared. Out of the various natural dyes, beetroot and strawberry extracts based dyes show good absorbance in the visible range of electromagnetic spectrum. On the other hand synthetic dye based on Ru complex shows strong absorbance over a wide range of visible spectrum. The absorbance increases with increase in concentration of Ru in ethanol. The extracts of beetroot, strawberry and mixed fruits show a peak in absorbance spectra at 501nm, 416nm and 332nm respectively, indicating the absorption over wide range of visible spectrum. Maximum efficiency of solar cell obtained with synthetic and natural dyes are 5% and 1.5% respectively.