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.

Microbial fuel cell: a green approach for the utilization of waste for the generation of bioelectricity

Abstract: Today we are witnessing a global energy crisis due to huge energy demands and limited resources. Non-renewable energy sources are depleting and renewable energy sources are not properly utilized. There is an immediate need for search of alternate routes for energy generation. Microbial fuel cell (MFC) technology, which uses microorganisms to transform chemical energy of organic compounds into electricity is considered a promising alternative. Extensive studies have corroborated new insights into MFC, which show that a wide array of carbon sources including wastes can be employed using a variety of microbes. Consequently, microbial transformation of wastes using novel bioremediation strategies such as MFC for energy generation is considered as an efficient and environmentally benign approach. This paper deals with critical review of different classes of xenobiotics and wastes that can be employed for bioenergy generation, microorganisms involved, power output, major benefits, challenges and pit holes of MFC technology.

Characterisation of carbonaceous materials using Raman spectroscopy: a comparison of carbon nanotube filters, single- and multi-walled nanotubes, graphitised porous carbon and graphite

Abstract: Multi-walled carbon nanotube (MWCNT) filters have been recently synthesised which have specific molecular filtering capabilities and good mechanical strength. Optical and scanning electron microscopy (SEM) reveals the formation of highly aligned arrays of bundles of carbon nanotubes having lengths up to 500 µm. The Raman spectra of this material along with four other carbonaceous materials, commercially available single-walled carbon nanotubes (SWCNTs) and MWCNTs, graphitised porous carbon (Carbotrap) and graphite have been recorded using two-excitation wavelengths, 532 and 785 nm, and analysed for band positions and shape with special emphasis paid to the D-, G- and G′-bands. A major difference between the different MWCNT varieties analysed is that G-bands in the MWCNT filters exhibit almost no dispersion, whereas the other MWCNTs show a noticeable dispersive behaviour with a change in the excitation wavelength. Spectral features similar to those of the MWCNT filter varieties were observed for the Carbotrap material. From the line shape analysis, the intensity ratio, ID/IG, of the more ordered MWCNT filter material using the integral G-band turns out to be two times lower than that of the less ordered MWCNT filter product at both excitation wavelengths. This parameter can, therefore, be used as a measure of the degree of MWCNT alignment in filter varieties, which is well supported also by our SEM study. Copyright © 2008 John Wiley & Sons, Ltd.

Emerging paradigms of tree phenology in dry tropics

Abstract: The tropical dry forests constitute a mosaic composed of several phenological functional types adapted to seasonal drought in different ways Various functional types differ with respect to phenological timing and triggering factors, water relations, extent of deciduousness (∼ leaflessness), etc Duration of deciduousness in tropical trees (reflecting integrated effect of seasonal drought, tree characteristics and soil moisture conditions) is related to leafing patterns and resource use rates Vegetative and flowering phenology of trees in dry tropics is primarily affected by the periodicity of rainfall and soil water availability Occurrence of leaf-flushing as well as flowering during summer in majority of Indian tropical trees, when drought is severe, seems to be a unique adaptation to survive under strongly seasonal climate having a short growth promoting wet period and a long growth constraining dry period The key phenological themes that need research focus in the dry tropics are: duration of deciduousness, timing of vegetative bud break, leaf strategy, water relations, seasonal flowering types and asynchrony Analysis of functional types based on the duration of deciduousness and timing of bud break may enable better assessment of future climate change impact There is a need for long-term quantitative documentation of tree phenological patterns in India through a phenological station network in diverse climatic/vegetational zones