University of Burdwan

About: University of Burdwan is a education organization based out in Barddhamān, West Bengal, India. It is known for research contribution in the topics: Population & Nanocrystalline material. The organization has 2492 authors who have published 5389 publications receiving 74865 citations. The organization is also known as: BU & Burdwan University.

An efficient GA–PSO approach for solving mixed-integer nonlinear programming problem in reliability optimization

Abstract: This paper deals with the development of an efficient hybrid approach based on genetic algorithm and particle swarm optimization for solving mixed integer nonlinear reliability optimization problems in series, series–parallel and bridge systems. This approach maximizes the overall system reliability subject to the nonlinear resource constraints arising on system cost, volume and weight. To meet these purposes, a novel hybrid algorithm with the features of advanced genetic algorithm and particle swarm optimization has been developed for determining the best found solutions. To test the capability and effectiveness of the proposed algorithm, three numerical examples have been solved and the computational results have been compared with the existing ones. From comparison, it is observed that the values of the system reliability are better than the existing results in all three examples. Moreover, the values of average computational time and standard deviation are better than the same of similar studies available in the existing literature. The proposed approach would be very helpful for reliability engineers/practitioners for better understanding about the system reliability and also to reach a better configuration.

Facile synthesis of SnO2–PbS nanocomposites with controlled structure for applications in photocatalysis

Abstract: Recent studies have shown that SnO2-based nanocomposites offer excellent electrical, optical, and electrochemical properties. In this article, we present the facile and cost-effective fabrication, characterization and testing of a new SnO2-PbS nanocomposite photocatalyst designed to overcome low photocatalytic efficiency brought about by electron-hole recombination and narrow photoresponse range. The structure is fully elucidated by X-ray diffraction (XRD)/Reitveld refinement, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area analysis, and transmission electron microscopy (TEM). Energy-dispersive X-ray spectroscopy (EDX) spectrum imaging analysis demonstrates the intermixing of SnO2 and PbS to form nanocomposites. A charge separation mechanism is presented that explains how the two semiconductors in junction function synergistically. The efficacy of this new nanocomposite material in the photocatalytic degradation of the toxic dye Rhodamine B under simulated solar irradiation is demonstrated. An apparent quantum yield of 0.217 mol min(-1) W(-1) is calculated with data revealing good catalyst recyclability and that charge separation in SnO2-PbS leads to significantly enhanced photocatalytic activity in comparison to either SnO2 or PbS.

On equivalency of various geometric structures

Abstract: In the literature we see that after introducing a geometric structure by imposing some restrictions on Riemann–Christoffel curvature tensor, the same type structures given by imposing same restriction on other curvature tensors being studied. The main object of the present paper is to study the equivalency of various geometric structures obtained by same restriction imposing on different curvature tensors. In this purpose we present a tensor by combining Riemann–Christoffel curvature tensor, Ricci tensor, the metric tensor and scalar curvature which describe various curvature tensors as its particular cases. Then with the help of this generalized tensor and using algebraic classification we prove the equivalency of different geometric structures (see Theorems 6.3, 6.4, 6.5, 6.6 and 6.7; Tables 1 and 2).

Smoke repellency and mosquito larvicidal potentiality of Mesua ferra L. leaf extract against filarial vector Culex quinquefasciatus Say

Abstract: Objective Present study was made to evaluate the smoke repellent potentiality and mosquito larvicidal activity of Mesua ferra (M. ferra) leaves against filarial vector Culex quinquefasciatus (Cx. quinquefasciatus) . Methods Crude, petroleum-ether, chloroform: methanol (1:1 v/v) and ethyl acetate extracts of mature plant leaves were investigated to establish its biocontrol potentiality under laboratory condition against larvae of Cx. quinquefasciatus at different concentrations i.e. 25 ppm, 50 ppm and 75 ppm. Mosquito coil prepared from M. ferra leaves powder were tested for smoke toxicity effect against Cx. quinquefasciatus adult mosquitoes. Results The mortality rates of crude extract at 0.5% concentration were higher than all other concentrations tested against the first, second, third and fourth instars larvae at 24 h, 48 h and 72 h of exposure. Larval mortality rate in chloroform: methanol (1:1 v/v) extract was significantly higher ( P 50 value of petroleum ether, chloroform: methanol (1:1 v/v) and ethyl acetate extracts were 195.33 ppm, 27.28 ppm and 74.19 ppm respectively, after 48 h of exposure. Smoke exposed gravid females oviposited fewer eggs when compared to non exposed female mosquitoes. Conclusions In conclusion M. ferra crude and chloroform: methanol (1:1) extract can be used effectively against mosquito control programmes. Smoke from M. ferra can play an important role in the interruption of transmission of those diseases where mosquitoes act as vector at the individual level.