Observations of TeV gamma-rays from Mrk 421 during Dec. 2005 to Apr. 2006 with the TACTIC telescope

The TACTIC $\gamma$-ray telescope has observed Mrk 421 on 66 clear nights from Dec. 07, 2005 to Apr. 30, 2006, totalling $\sim$ 202 hours of on-source observations. Here, we report the detection of flaring activity from the source at $\geq$ 1 TeV energy and the time-averaged differential $\gamma$-ray spectrum in the energy range 1-11 TeV for the data taken between Dec. 27, 2005 to Feb. 07, 2006 when the source was in a relatively higher state as compared to the rest of the observation period. Analysis of this data spell, comprising about $\sim$97h reveals the presence of a $\sim 12.0 \sigma$ $\gamma$-ray signal with daily flux of $>$ 1 Crab unit on several days. A pure power law spectrum with exponent $-3.11\pm0.11$ as well as a power law spectrum with an exponential cutoff $(\Gamma = -2.51\pm0.26$ and $E_0=(4.7\pm2.1) TeV)$ are found to provide reasonable fits to the inferred differential spectrum within statistical uncertainties. We believe that the TeV light curve presented here, for nearly 5 months of extensive coverage, as well as the spectral information at $\gamma$-ray energies of $>$ 5 TeV provide a useful input for other groups working in the field of $\gamma$-ray astronomy.Comment: 13pages,4figures; Accepted for publication in Astroparticle Physic

Environmental Pollution from Coal Mining Activities in Damodar River Basin, India

Damodar river basin is a repository of 46% of Indian coal reserve. Exploitation of coal and related industries in this area have exerted a great impact on the environment of the basin. Hydrogeochemical analyses of mine water were carried out for all the major coalfields. The analysis revealed that total dissolved solids, sulphate, hardness and iron content are high. Acid mine drainage problem is not observed in all the coalfields of the basin except in one or two mines. Biological contamination are also observed in terms of MPN in the mine water. As a consequence of underground mining, huge volume of polluted water, flooded in the mines, are channeled into the stream or river which in turn gets chemically polluted. Activities other than mining like coal beneficiation and preparation plant also generate huge amount of water effluent which affects the aquatic ecosystem and reduces biodiversity

Effect of coal mining and coal based industrial activities on water quality of the river Damodar with specific reference to heavy metals

A study of water quality of the river Damodar in a stretch of 50 km in Jharia Coalfield region was carried out with specific reference to heavy metals. Sediments of the river bed was characterized for heavy metals, fe, Mn, Cd, Cr, Ni and Pb to determine total carry over of heavy metals in the river body. Industrial effluents have been characterised to see the level of pollution the river receiving. DO and BOD profile study.showed that the most vulnerable zone of the river was a stretch of 15 km in Jharia Coalfield. Organic pollution level of the river was found to be high during lean period resulting high values of BOD and COD. Heavy metal concentrations in the river sediments were found higher in comparison to the river water. Variation in concentration of metals in sediment and water was observed in different stretches of the river. The deposition of Cr in sediment was higher in downstream in comparison to other stretches. The study also reflected that Fe and Mn were irreversibly retained in the sediment and this effect was observed for other metals also in decreasing order of Pb, Cr, Ni and Cd

Rich can get poor: Conversion of hub to non-hub proteins

10.1007/s11693-009-9024-9Systems and Synthetic Biology23-475-8

Not Available

Not AvailableInoculation of phosphate solubilizing bacteria (PSB) and phosphorus mobilizing arbuscular mycorrhiza (AM) with low quality rock phosphate (RP) can be an alternative source to one of the costliest phosphatic fertilizers in India, i.e. single superphosphate, by enhancing phosphorus influx and modification of root properties. Co-inoculation of PSB and AM may play a pivotal role to reduce phosphorus application through RP. Root properties and grain yield of irrigated soybean-wheat cropping system were evaluated with two levels of RP (100 and 50% recommended P (1.0 RP and 0.5 RP)) and different combinations ofPSB and AM with0.5 RP (0.5 RP + PSB, 0.5 RP + AM and 0.5 RP + PSB + AM) versus 100% recommended P application through soluble single superphosphate (1.0 SP) in the Indo-Gangetic plains. The P influx under 0.5 RP + PSB + AM and 1.0 SP were statistically at par with each other and the former treatment provided 0.6 and 3.2% higher value than the later in soybean and wheat, respectively. The root surface area density (RSAD) of soybean and wheat under 0.5 RP + PSB + AM (13.71 and 6.16m2 m−3, respectively) and 1.0 SP (13.70 and 6.37 m2 m−3, respectively) were non-significant and almost equal with each other. The values of root cation exchange capacity and other root properties under 0.5 RP + PSB + AM and 1.0 SP were also non-significant. The improved root properties under 0.5 RP + PSB + AM provided statistically at par grain yield with 1.0 SP for both soybean and wheat crops. The yield under 0.5 RP + PSB + AM of soybean crop was 3.4% higher than 1.0 SP. The net returns US$−1 invested was significantly higher under 0.5 RP + PSB + AM compared to 1.0 SP for both soybean and wheat crops. Coinoculation of PSB and AM with 50% of recommended P through RP could be recommended for better root properties and profitable grain yield of soybean-wheat cropping system in the Indo-Gangetic alluvial plains.Not Availabl

Temperature dependent shape transformation of Ge nanostructures by the vapor-liquid-solid method

A vapor-liquid-solid method has been used to study the temperature dependent growth mechanism of Ge nanostructures on Au-coated Si (100) substrates. The formation of Ge nanodots, nanorods, and nanowires has been observed at different growth temperatures. The diameter of grown nanowires is found to be varying from 40 to 80 nm and that of nanorods from 70 to 90 nm, respectively. A comparative study has been done on three types of samples using x-ray diffraction and Raman spectroscopy. Photoluminescence spectra of grown nanostructures exhibit a broad emission band around 2.6 eV due to oxide related defect states