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

Design of a high Temperature ‘Anaerobic Gas-Furnace’ suitable for Pyrolysis

The need for a high temperature anaerobic furnace for pyrolysis is fast becoming indispensable for technological growth in Nigeria. In this project, a high temperature furnace was designed and built using the principle of heat transfer. The furnace was made of casing of low carbon steel sheets in four rectangular shapes. The refractories made of bricks filling the cavities of the furnace. This help to preserve heat loss. The pyrolysis capsule (chamber) was made of high carbon steel tube with flanges which can be opened for loading the products and evacuate. The mechanism to regulate the temperature and the gas input were installed. The furnace was gas-fired due to its high combustibility and providing a solution to the limited supply of electricity in the country. The prototype furnace produced is easy to use and multi-versatile with the innovation of the detachable pyrolysis capsule which can be modified by intent of pyrolysis products and byproducts. The pyrolysis capsule is surrounded by the flame jacket (of the furnace main chamber) created to heat up the capsule at a regulated rate to any desired temperature up to 1,200 oC with the automated control system for the gas supply unit. The designed high temperature anaerobic gas furnace is deployable for a wide range of pyrolysis processes and can be used for different precursors to produce an achievable end-product within the temperature limit

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

Reconnaissance Study of Smectite ores of Lafarge- Ewekoro, Ogun State Nigeria for Industrial Applications

This work aimed to study the aluminosilicate ore contents at Lafarge Ogun State environ as a means of identification of background variation of smectite in the ore-bodied environment. Smectite clay samples (bentonite) were collected from Larfarge Ewekoro environ, while zeolite used as a standard in this work was obtained from Petroleum Department of Covenant University for comparism purpose. The samples were digested with nitric acid, HNO3 and hydrochloric acid, HCl, after which the digested samples were characterized with, ultraviolet visible (UV-VIS), scanning, absorbance; and % transmittances. The results revealed similarity in ultraviolet visible for bentonite and zeolite with predominance of iron in bentonite samples. The colouration of bentonite due to the presence of transition metals in the environment under study could be of industrial uses in the manufacture of coloured wares and tiles, and magnetic ceramic, though further pre-application specific investigations are recommended. Also, the observed properties favour many aspects of industrial applications such as in pharmaceuticals, refractories, adhesives and porcelain wares. These will help in setting up small and medium-sized enterprise in this area resulting in employment creation and revenue generation

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