Ethanoic Extractions of Lagerstroemia Speciosa Flowers for Dye Sensitized Solar Cell

Dye-sensitized solar cells (DSSCs) have attracted great interest as potential candidates of “low cost solar cells” in the solution of global energy demand. To accelerate the progress of DSSCs, it is important to evaluate device performance with reliable measurements that will enable more effective comparison and application of new findings in materials and technologies by different research groups. In this perspective, Lagerstroemia Speciosa Flowers dye was extracted using two methods of soxhlet and cold ethanol extraction. Our findings show that the open-circuit voltage is low which might be due to reduction in electron conduction .The Conversion efficiency of cold ethanol dye extract is higher than that of the soxhlet ethanol dye extract, which indicate that the dye pigment is more degraded in the latter method. However with further investigation, the constructed DSSC’s be made to serve as a power source for driving self-powered devices.Key word: - lagerstroemia speciosa flowers, Ethanol, Dye Sensitized Solar Cell

Estimation of Optimal Insulation Thickness for a Cylindrical Ceramic Crucible

High temperature thermal energy storage (TES) systems have the capacity to achieve high thermal efficiencies due to their high operating temperatures. However, they tend to experience higher thermal losses which adversely affect their thermal cycles. This paper focuses on heat loss estimation from a TES system operating at 800 ℃, insulated in a cylindrical ceramic crucible, and the determination of the optimal insulation thickness of the crucible. Parameters affecting heat loss such as thermal conductivity of the ceramic material and convective heat transfer coefficient were simulated. It was observed that the thermal conductivity of the crucible had a greater effect on the rate of heat loss than the convective heat transfer coefficient. Furthermore, an increase in the length of the crucible increased the thermal mass of the crucible causing it to lose heat at higher rate. The deduced optimal radial thickness for the operating temperature range was 0.075 m. In conclusion, addition of more refractories beyond the optimal radius will not significantly reduce the rate of heat loss and will make the insulating crucible bulkier

Mathematical Analysis and Thermal Modelling ofa Pilot-Scale Pyrolysis Gas Furnace

Anumerical model for the thermal operations directly related to all significant heat and mass transfer within a designed furnace chamber was developed, taking into consideration the surface area of the internal structures and surrounding furnace walls of the furnace. Some specific sets of theories on the internal and external flow of heat energy in furnaces as well as boilers were adopted and modified to exhibit a steady-state condition model for the designed gas-fired pyrolytic furnace. Existing thermal models were selected and adjusted to arrive at a unique mathematical model that was used to analyse and verify the heat distribution at different regions of the built pyrolytic furnace with the aid of the basic principles of heat and mass transfer and the associated assumptions. The distinctive numerical model formed the basis for the MATLAB Simulink program used to validate the experimental data gotten from runs of heating and cooling of the pyrolytic furnace during operation. The result of the simulated behaviour of the furnaceachieved afit to the estimation of the data of87.16%in correlation with the real experimental data. This established a thermal function that can be used asa model for potential optimisation of the pyrolysis process of the pilot furnace

Analysis of van der waal equation near the critical point

We report detailed thermodynamic properties of Na in molten Na-Cs alloys obtained by using the simple theoretical model of Heterocordination. This model has been utilized to determine the free energy of mixing, concentration fluctuations in the long wavelength limit Scc (0), the Warren Crowley short-range order parameter, heat of mixing, entropy of mixing and diffusion coefficient. From these thermodynamic quantities we find that Na-Cs exhibits strong deviation from ideality at all the composition, therefore, it is truly a demixing liquid alloy. This conclusion was justified by the plot of Scc (0), which showed that its values are far greater than the ideal values. Qualitative agreement between the calculated and the experimental quantities for most of the thermodynamics properties was also obtained for the liquid alloys. These liquid alloys further exhibit a high asymmetry in their thermodynamics properties such as the Gibbs free energy and its diffusion

Ethanoic Extractions of Lagerstroemia Speciosa Flowers for Dye Sensitized Solar Cell

Dye-sensitized solar cells (DSSCs) have attracted great interest as potential candidates of “low cost solar cells†in the solution of global energy demand. To accelerate the progress of DSSCs, it is important to evaluate device performance with reliable measurements that will enable more effective comparison and application of new findings in materials and technologies by different research groups. In this perspective, Lagerstroemia Speciosa Flowers dye was extracted using two methods of soxhlet and cold ethanol extraction. Our findings show that the open-circuit voltage is low which might be due to reduction in electron conduction .The Conversion efficiency of cold ethanol dye extract is higher than that of the soxhlet ethanol dye extract, which indicate that the dye pigment is more degraded in the latter method. However with further investigation, the constructed DSSC’s be made to serve as a power source for driving self-powered devices.Key word: - lagerstroemia speciosa flowers, Ethanol, Dye Sensitized Solar Cell

Photo Degradation in Dye-Sensitized Solar Cells

International audienceMesoporous TiO2 of 20nm diameter is prepared in-tandem with organic dyes and based on Fluorine – doped SnO2 (FTO), conducting base is produced by hydrothermal process. The prepared mesoporous Cola Acuminata (C.acuminata), Lupinus Arboreus (L.arboreus) and Bougainvillea Spectabilis (B.spectabilis) films (0.16 cm 2) are applied; individually and in combination as interfacial layer in-between nanocrystalline TiO2 (NC-TiO2) and the FTO anode in the dye-sensitized solar cell (DSSC). Absorbance index (A.I) of all three dyes was studied within wavelength range 200-900 nm for a period of 11 months, equivalent to 352 sun exposure. C.acuminata had A.I value 4.00 that decreased to 2.32 under exposure to AM1.5 global conditions. B.spectabilis A.I was 1.19 but decreased to 0.520 within same period of study. Combination of C.acuminata and B.spectabilis gave A.I value 1.40, dye cocktails of C.acuminata, B.spectabilis and L.arboreus gave 2.00 A.I value for same wavelength range. A UV/Vis photo spectrometer was used to determine the prominent peaks and absorbance at such wavelengths. This exponential relationship is subject of our explorative stud