Banaras Hindu University

About: Banaras Hindu University is a education organization based out in Varanasi, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 11858 authors who have published 23917 publications receiving 464677 citations. The organization is also known as: Kashi Hindu Vishvavidyalay & Benares Hindu University.

Luminescence study on Eu(3+) doped Y(2)O(3) nanoparticles: particle size, concentration and core-shell formation effects.

Abstract: Nanoparticles of Eu3+ doped Y2O3 (core) and Eu3+ doped Y2O3 covered with Y2O3 shell (core?shell) are prepared by urea hydrolysis for 3?h in ethylene glycol medium at a relatively low temperature of 140??C, followed by heating at 500 and 900??C. Particle sizes determined from x-ray diffraction and transmission electron microscopic studies are 11 and 18?nm for 500 and 900??C heated samples respectively. Based on the luminescence studies of 500 and 900??C heated samples, it is confirmed that there is no particle size effect on the peak positions of Eu3+ emission, and optimum luminescence intensity is observed from the nanoparticles with a Eu3+ concentration of 4?5?at.%. A luminescence study establishes that the Eu3+ environment in amorphous Y (OH)3 is different from that in crystalline Y2O3. For a fixed concentration of Eu3+ doping, there is a reduction in Eu3+ emission intensity for core?shell nanoparticles compared to that of core nanoparticles, and this has been attributed to the concentration dilution effect. Energy transfer from the host to Eu3+ increases with increase of crystallinity.

Pre-monsoon aerosol characteristics over the Indo-Gangetic Basin: implications to climatic impact

Abstract: . Sun/sky radiometer observations over the Indo-Gangetic Basin (IGB) region during pre-monsoon (from April–June 2009) have been processed to analyze various aerosol characteristics in the central and eastern IGB region, represented by Kanpur and Gandhi College, respectively, and their impacts on climate in terms of radiative forcing. Monthly mean aerosol optical depth (AOD at 500 nm) and corresponding Angstrom Exponent (AE at 440–870 nm, given within the brackets) was observed to be about 0.50 (0.49) and 0.51 (0.65) in April, 0.65 (0.74) and 0.67 (0.91) in May and 0.69 (0.45) and 0.77 (0.71) in June at Kanpur and Gandhi College, respectively. Results show a positive gradient in AOD and AE from central to eastern IGB region with the advancement of the pre-monsoon, which may be caused due to diverse geographical location of the stations having different meteorological conditions and emission sources. Relatively lower SSA was observed at the eastern IGB (0.89) than the central IGB (0.92) region during the period, which suggests relative dominance of absorbing aerosols at the eastern IGB as compared to central IGB region. The absorbing aerosol optical properties over the station suggest that the atmospheric absorption over central IGB region is mainly due to dominance of coarse-mode dust particles; however, absorption over eastern IGB region is mainly due to dominance of fine-particle pollution. The derived properties from sun/sky radiometer during pre-monsoon period are used in a radiative-transfer model to estimate aerosol radiative forcing at the top-of-the atmosphere (TOA) and at the surface over the IGB region. Relatively large TOA and surface cooling was observed at the eastern IGB as compared to the central IGB region. This translates into large heating of the atmosphere ranging from 0.45 to 0.55 K day−1 at Kanpur and from 0.45 to 0.59 K day−1 at Gandhi College.

Exploring marginal and degraded lands for biomass and bioenergy production: An Indian scenario

Abstract: Globally, the share of renewable energy is limited to 19% of the total energy consumption. Out of which, 9.3% is shared by traditional biomass. In India, the installed capacity of energy production from biomass is estimated as 12.8% of the total renewables. Although this scenario is at par with the global level, even this share of bioenergy production is not sufficient to meet the present and future energy demands of India. Therefore, there is an immediate need to maximize the bioenergy production in India. Apart from the reduced emission rate than the fossil fuels, bioenergy has also immense potential to mitigate various environmental issues and therefore the biofuel cultivation has been considered as an additional opportunity for land restoration. However, the land availability for bioenergy production is very limited since there is a growing demand to produce more food to feed the rapidly growing population. Therefore, the arable lands cannot be considered for bioenrgy production. Hence we propose that the sustainable intensification of bioenergy production from degraded land is a viable option because the wise and judicious utilization of marginal and degraded lands can play a vital role in solving the conflict between food and fuel production and offer a sustainable solution to meet out the energy requirement of the society. In this backdrop, the present article is aimed to explore the prospects and promises of bioenergy production from the marginal and degraded lands of India. Since India has around 39.24 million hectares of wastelands, sustainable utilization of such land would provide multipurpose benefits such as biomass and bioenergy production, soil carbon sequestration and regaining ecosystem services.