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Natural Pigments as Sensitizers for Dye Sensitized Solar Cells
Ezeoke Jonathan,
Muhammad Yusuf Onimisi,
Eli Danladi
Issue:
Volume 5, Issue 5, October 2016
Pages:
31-34
Received:
25 July 2016
Accepted:
5 August 2016
Published:
29 August 2016
Abstract: The performance of dye sensitized solar cells (DSSCs), sensitized with natural pigments extracted from mango (mangifera indica), carica papaya, moringa oleifera leaves and bougainvillea flower was demonstrated. The photoactive electrodes of the various DSSCs were sensitized with aqueous extract of the natural pigments. The resulting photoelectrodes were successfully incorporated into the DSSCs. The photoelectrochemical perfomance of the DSSCs were evaluated under 100 mAcm-2 light intensity with open circuit voltage (VOC) ranging from 0.36 to 0.49 V and short circuit current density (JSC) ranging from 0.0134 to 0.1314 mAcm-2. From the photovoltaic performance of the extracts, the Mangifera Indica extract sensitized solar cell gave the best performance with Jsc of 0.1314 mAcm-2, Voc of 0.49 V, a fill factor (FF) of 0.59, and an overall solar energy conversion efficiency (η) of 0.038%. The sensitization performance related to the interaction between the dye and TiO2 surface is discussed.
Abstract: The performance of dye sensitized solar cells (DSSCs), sensitized with natural pigments extracted from mango (mangifera indica), carica papaya, moringa oleifera leaves and bougainvillea flower was demonstrated. The photoactive electrodes of the various DSSCs were sensitized with aqueous extract of the natural pigments. The resulting photoelectrodes...
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Effect of Finishing Machine Parameters on Dimensional Stability of Single Lacoste Cotton Knitted Fabric
Md. Shaheen Iqbal,
Md. Abdullah Al Mamun,
Md. Abu Bakar Siddiquee,
A. K. M. Ayatullah Hosne Asif
Issue:
Volume 5, Issue 5, October 2016
Pages:
35-43
Received:
21 June 2016
Accepted:
1 September 2016
Published:
11 October 2016
Abstract: The effect of finishing machine parameters on dimensional stability of single lacoste cotton knitted fabric was studied in this research. The dimensional properties of the single lacoste cotton knitted fabric such as shrinkage and spirality were investigated. All tests were carried out according to the ISO standards. In this research effect of dryer machine, stenter machine and compactor machine parameters on dimensional stability of single lacoste cotton knitted fabric were evaluated. The surface analysis of single lacoste cotton knitted fabrics were examined by scanning electron microscopy (SEM) on the samples of after drying, stentering and compacting respectively. The surface analysis of single lacoste cotton knitted fabric was also investigated by SEM on the softener treated and softener untreated samples after compacting process. From the result it was observed that fabrics show lowest shrinkage in both length and width wise and spirality for drying process than the stentering process. It was also observed that length wise and width wise shrinkage and spirality of the fabrics become gradually better by increasing the overfeed % of both dryer and compactor machine. On the other hand length wise shrinkage of the fabrics become successively lower and width wise shrinkage of the fabrics become gradually higher by increasing the diameter of both dryer and compactor machine. But stretching of both dryer and compactor machine diameter has no significant influence on spirality. It was also noticed that width wise shrinkage of the fabric becomes gradually better and spirality becomes gradually higher by increasing the felt tension of the compactor machine.
Abstract: The effect of finishing machine parameters on dimensional stability of single lacoste cotton knitted fabric was studied in this research. The dimensional properties of the single lacoste cotton knitted fabric such as shrinkage and spirality were investigated. All tests were carried out according to the ISO standards. In this research effect of drye...
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Validations of a Model to Estimate Thermal Conductivities of Ceramics
Issue:
Volume 5, Issue 5, October 2016
Pages:
44-50
Received:
6 September 2016
Accepted:
18 September 2016
Published:
11 October 2016
Abstract: The Effective Medium Theory Model (EMTM) used in this work is based on the assumption that every phase of the matrix is embedded in a homogeneous medium with conductivity keff to be determined self-consistently. It is based on dilute spherical inclusions of one phase embedded in a matrix of a second phase. Several Samples of composite ceramics that are mechanically strong, relatively non-porous and anisotropic have been investigated. A comparison between the measured data and the results predicted by EMTM were made to validate the model for these ceramic samples. In particular, we investigate the effect of mineralogy (constituents) in ceramics and their spatial distribution profile to validate the homogeneity conditions of the model. Preliminary indicators of validation were used to check the bulk and surface homogeneities. This can be done either by roughly estimating Wiener bounds or by examining microscopically the surfaces of the samples. It turns out that the EMTM is a suitable one to estimate keff provided that the homogeneity conditions are satisfied.
Abstract: The Effective Medium Theory Model (EMTM) used in this work is based on the assumption that every phase of the matrix is embedded in a homogeneous medium with conductivity keff to be determined self-consistently. It is based on dilute spherical inclusions of one phase embedded in a matrix of a second phase. Several Samples of composite ceramics that...
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Effect of Sulfur on the Structure and Physical Properties of Vanadium-Iron-Lithium-Silicate Glass and Glass-Ceramics Nano Composite
M. Y. Hassaan,
H. H. El-Bahnasawy,
S. M. Salem,
T. Z. Amer,
M. G. Moustafa,
A. G. Mostafa
Issue:
Volume 5, Issue 5, October 2016
Pages:
51-56
Received:
7 September 2016
Accepted:
21 September 2016
Published:
11 October 2016
Abstract: Glass sample with the composition 1 Li2O • 0.25 Fe2O3• 0.25 V2O5• 1.5 SiO2 has been studied for the usage as a cathode material in solid batteries. Another sample with the previous composition in addition to 5wt. % sulfur as reduced agent to yelled multi-valance Fe and V ions was also studied. Both sulfur-free and sulfur-doped glass samples were subjected to heat treatment for one hour at 550°C to obtain two glass–ceramic samples. Structural studies were made using X-ray diffraction (XRD), Mössbauer effect (ME) and Fourier-transform infrared spectroscopy (FT-IR). The precipitation of various phases in heat treated glass samples with particle size in the nano-range was observed in X-ray pattern. Mössbauer spectra indicated that iron exist as a ferric ions occupy two non-equivalent tetrahedral sites in the sulfur-free samples, while ferrous ions in octahedral site in addition to the previous two ferric phases was appeared in sulfur-doped samples. Differential thermal analysis (DTA) was also carried out to monitor the crystallization temperature and the thermal stability of the obtained glasses. DC electrical conductivity measurements exhibit an enhancement of the conductivity of sulfur-doped glass sample compared with sulfur-free which make it more suitable to use as cathode in the solid batteries.
Abstract: Glass sample with the composition 1 Li2O • 0.25 Fe2O3• 0.25 V2O5• 1.5 SiO2 has been studied for the usage as a cathode material in solid batteries. Another sample with the previous composition in addition to 5wt. % sulfur as reduced agent to yelled multi-valance Fe and V ions was also studied. Both sulfur-free and sulfur-doped glass samples were su...
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