Antioxidant &antimicrobial efficacy of Ficus religiosa L. & Ficus benghalensis L. PLANT

Medicinal plants are used to cure variety of diseases for long years. The aim of the study was to identify such plants with antimicrobial and antioxidant efficiency for controlling some disease causing pathogens. The locally available plants like Ficus religiosa and Ficus bengalensis have the capability to cure diseases traditionally since long years, due to this reasons these two plants were selected for the study. Various methods are tried to standardize the extraction of antimicrobial activity. It was found that methanol extraction of two plants that is Ficus religiosa and Ficus benghalensis showed high antimicrobial activity than the aqueous extract against Klebsilla pneumonia species and Bacillus subtilis species. The plant extracts was used to study their photochemical compositions i.e. total phenols contents, flavonoids contents, terpenoids content and proteins contents. Most of the biologically active phytochemicals presents in the methanol extract. For invitro antioxidant activities including 1, 1 -Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and reducing power activity was performed. In DPPH activity ,when the decrease in absorbance at 517nm it increases the scavenging activity of the plants sample, then the plants sample colour is decolorized due to presence of antioxidant. For DPPH experiment ascorbic acid taken as the standard solution. The another antioxidant activity is reducing power, the result obtained that is all the sample have increased absorbance of reaction mixture and it was indicated the greater reducing power. The results obtained in this study clearly indicated that leaf and bark of Ficus religiosa and Ficus benghalensis have a significant role to use as a natural antioxidant. It experimentally reported by the various extract concentration from Ficus religiosa leaf have interesting antioxidative properties and symbolize a potential source of medicine for the treatment of inflammatory activity and wound healing properties. The results obtained that the antioxidant activity of these plant samples and could be utilized as potential source of natural antioxidant in the food or in pharmaceutical industries

Effect on TEG performance for waste heat recovery of automobiles using MgO and ZnO nanofluid coolants

Present study deals with the theoretical analysis for the performance comparison of automotive waste heat recovery system with EG-W, ZnO and MgO nanofluidas coolants for TEG system. Effects on performance parameters i.e power output, conversion efficiency and circuit voltage of TEG system with exhaust inlet temperature, total area of TEG, Reynolds number and particle concentration of nanofluids for TEG system have been investigated. Theoretical performance analysis revealed enhancement in output power, conversion efficiency and voltage of the TEG system for MgO nanofluid, followed by ZnO and EG-W coolants. The power output and the conversion efficiency using 1% vol. fraction MgO nanofluid at an inlet exhaust temperature of 500 K, were enhanced by 11.38% and 10.95% respectively, as compared to EG-W coolants. The further increase in nanofluid concentration exhibited a progressive effect on output performance of the TEG system. Further analysis shows that there exists an optimal total area of TEGs for maximum output performance of the system. With MgO nanofluid as a coolant, total area of TEGs can be reduced by up to 33% as compared to EG-W, which would bring significant convenience for the arrangement of TEGs and reduce the cost of TEG system. Keywords: Nanofluid, Reynolds number, Circuit voltage, Thermoelectric generator, Conversion efficiency, Waste heat recover

Performance comparison of various coolants for louvered fin tube automotive radiator

In the present study, screening of various coolants (water, ethylene glycol, propylene glycol, brines, nanofluid, and sugarcane juice) for louvered fin automotive radiator has been done based on different energetic and exergetic performance parameters. Effects on radiator size, weight and cost as well as engine efficiency and fuel consumption are discussed as well. Results show that the sugarcane juice seems to be slightly better in terms of both heat transfer and pumping power than water and nanofluid, whereas significantly better than ethylene glycol and propylene glycol. For same heat transfer capacity, the pumping power requirement is minimum and vice-versa with sugarcane juice, followed by nanofluid, water, EG and PG. Study on brines shows an opportunity to use water+25% PG based nanofluids for improvement of performance as well as operating range. Replacement of water or brines by using sugarcane juice and water or wa-ter+25% PG based nanofluids will reduce the radiator size, weight and pumping power, which may lead to increase in compactness and overall engine efficiency or reduction in radiator cost and engine fuel consumption. In overall, both sugarcane juice and nanofluid seem to be potential substitutes of water. However, both have some challenges such as long term stability for practical use