5 research outputs found

    The impact of randomness on high speed wireless campus network in IEEE802.11e

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    The enhancement of channel access mechanism assures to provide Quality of Service (QoS) using the service differentiation mechanism over WLAN in IEEE802.11e. The service differentiation scheme is used in the Enhanced Distributed Channel Access (EDCA) MAC layer protocol and this protocol is used the random back-off window algorithm to provide QoS for the real time multimedia applications. However, the back-off window mechanism ensures QoS to satisfy multimedia traffic but it only the probabilistic QoS due to the random nature of the algorithm. As like as the randomness of the mobility models that can be reduced the network performance. In this paper, we analyze the proposed network performance based on the variation of randomness using different seed values and evaluate the network performance using various performance metrics in IEEE802.11e

    Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

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    In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric) sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV–Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell’s (DSSC) photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric. Keywords: DSSC, Natural dye, TiO2 photoanode, Dye extracting solvent, Dye-adsorption tim
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