844 research outputs found

    Au9+ swift heavy ion irradiation of Zn[CS(NH2)2]3SO4 crystal: Crystalline perfection and optical properties

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    The single crystal of tris(thiourea)zinc sulphate (Zn[CS(NH2)2]3SO4) was irradiated by 150 MeV Au9+ swift heavy ions and analyzed in comparison with pure crystal for crystalline perfection and optical properties. The Fourier transform infrared and x-ray powder diffraction inferred that swift ions lead the disordering and breaking of molecular bonds in lattice without formation of new structural phases. High resolution X-ray diffraction (HRXRD) revealed the abundance of point defects, and formation of mosaics and low angle grain boundaries in the irradiated region of crystal. The swift ion irradiation found to affect the lattice vibrational modes and functional groups significantly. The defects induced by heavy ions act as the color centers and resulted in enhance of photoluminescence emission intensity. The optical transparency and band gap found to be decreased.Comment: 7 page

    Structure of human methaemoglobin: the variation of a theme

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    There has been considerable interest in the variability of the structure of the liganded haemoglobin after characterization of the R2 state in addition to the original relaxed R state. The structures of three crystallographically independent relaxed haemoglobin molecules have been determined through the X-ray structure analysis of the crystals of human methaemoglobin. The three molecules have quaternary structures intermediate between those of the R and R2 structures. The same is true about the disposition of residues in the 'switch' region. Thus it would appear that haemoglobin can access different relaxed states with varying degrees of similarity among them

    Rice area mapping in Palakkad district of Kerala using Sentinel-2 data and Geographic information system technique

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    Proper calculation of rice cultivation area well before harvest is critical for projecting rice yields and developing policies to assure food security. This research looks at how Remote Sensing (RS) and Geographic Information System (GIS) can be used to map rice fields in Palakkad district of Kerala. The area was delineated using three multi-temporal cloud free Sentinel-2 data with 10 m spatial resolution, matching to crop's reproductive stage during mundakan season (September-October to December-January), 2020-21. To make classification easier, the administrative boundary of district was placed over the mosaicked image. The rice acreage estimation and land use classification of the major rice tract of Palakkad district comprising five blocks was done using Iterative Self-Organisation Data Analysis Technique (ISODATA) unsupervised classification provision in ArcGIS 10.1 software, employing False Colour Composite (FCC) including Blue (B2), Green (B3), Red (B4) and Near-infrared (B8) Bands of Sentinel-2 images. The classification accuracy was determined by locating a total of 60 validation points throughout the district, comprising 30 rice and 30 non-rice points. The total estimated area was 24742.76 ha, with an average accuracy of 88.33% and kappa coefficient 0.766 in five blocks of Palakkad district. The information generated will be helpful in assessing the anticipated production as well as the water demand of the rice fields

    Distribution of luminescent Vibrio harveyi and their bacteriophages in a commercial shrimp hatchery in South India

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    Luminescent Vibrio harveyi is a natural microflora of marine and coastal water bodies and is associated with mortality of larval shrimp in penaeid shrimp hatcheries. It is also known that the bacteriophages occur virtually in all places where their hosts exist. In this study, distribution of luminescent V. harveyi and the bacteriophages affecting these hosts was examined in a commercial Penaeus monodon hatchery during three shrimp larval production cycles, including a cycle affected by luminescent bacterial (LB) disease outbreak

    Structures of human oxy- and deoxyhaemoglobin at different levels of humidity: variability in the T state

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    Nature of fireside deposits in a bagasse and groundnut shell fired 20 MW thermal boiler

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    The nature of deposit formation on the fireside surfaces of the boiler tubes in the various parts (water walls, platen superheater, final superheater, economizer, electrostatic precipitator etc.) of a commercial 20 MW stoker-fired boiler being fired with a mixture of 80% bagasse and 20% groundnut shell has been analyzed. The deposits in the various portions of the boiler were characterized by particle size analysis, chemical analysis, X-ray diffraction and scanning electron microscopy. The deposits were found to be mainly quartz, alkali and alkaline earth silicates and sulfates. From the phase constitution and other microscopic characteristics of the deposit, it can be inferred that the silicates in the deposit formed through inertial impaction and the sulfates formed by vapor phase deposition

    Bronchoalveolar lavage study in victims of toxic gas leak at Bhopal

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    Bronchoalveolar lavage using flexible fibreoptic bronchoscope was carried out in 50 patients 1-2½ yr after exposure to the ‘toxic gas’ at Bhopal. Thirty six patients in the analysis were categorised into 3 groups (viz., mild, moderate and severe), depending upon the severity of exposure. There was an increase in cellularity in the lower respiratory tract (alveolitis) of the severely exposed patients (in both smokers and non-smokers), compared to normals (P< 0.05). The increase in cellularity in severely exposed non-smokers was due to abnormal accumulation of macrophages (P<0.01), and in severely exposed smokers, to macrophages (P<0.01) and neutrophils (P<0.05). Mild and moderately exposed patients did not show significant change in cellularity in lower respiratory tract, compared to normal individuals (P>0.2). There was a trend towards increasing cellularity, as the severity increased (P < 0.0001) and higher numbers of total cells were seen in severely exposed smokers, suggesting that smoking is a risk factor. It appears, therefore, that subjects severely exposed to the toxic gas at Bhopal may have a subclinical alveolitis characterised by accumulation and possibly activation of macrophages in the lower respiratory tract. Smokers, who were exposed to the gas had in addition, accumulation of neutrophils

    Combustion and deposit formation behavior on the fireside surfaces of a pulverized fuel boiler fired with a blend of coal and petroleum coke

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    The thermochemistry of the combustion of a blend of coal and 5% petroleum coke was analyzed. Thermodynamic modeling and microscopic techniques were used to study the behavior of the inorganic constituents upon combustion of the blend of coal and petroleum coke. The chemical composition and phase constitution of the combustion products, as well as the deposits at several temperatures corresponding to those at the various parts of the boiler, were deduced by free-energy minimization. These results were compared with actual results obtained from a commercial pulverized fuel boiler fired with coal and petroleum coke blend. The deposits on the fireside surfaces of the boiler tubes in the various parts (water walls, platen superheater, final superheater, economizer, and electrostatic precipitator) of the commercial pulverized fuel boiler fired with coal and 5% petroleum coke were characterized by particle size analysis, chemical analysis, x-ray diffraction, optical microscopy, and scanning electron microscopy. The combustion gas composition was measured using a portable on-line gas analyzer for N 2 , O 2 , CO 2 , H 2 O, CO, NO, and SO 2 . The thermodynamically predicted compositions and phase constitutions for the gas phase as well as the condensed phases are in good agreement with the experimental results

    Evaluation of different media for cell proliferation in mantle tissue culture of the green mussel, Perna viridis (Linnaeus, 1758)

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    The aim of the present study was to establish a suitable culture system for tissue explants from the mantle of the green mussel, Perna viridis. The experiments were conducted using healthy, live green mussels in the size range of 75 to 110 g collected from Pulicat Lake, Tamil Nadu. Three different culture media namely M199, Leibovitz L-15 and sterile seawater were used to assess the most suitable medium for growth, proliferation and viability of mantle epithelial cells. The effect of the addition of two supplements viz., 10% foetal calf serum (FCS) and 0.1% yeast extract to the culture media was also evaluated. After carefully isolating the pallial layer from the mantle tissue, 1-2 mm2 size explants were successfully cultured in 12-well plates at 25°C for up to 14 days. Cultures were monitored under light and phase contrast objectives in an inverted microscope. Cell counts were made and cell size was measured for each treatment. Cells were observed to migrate from the periphery of the explant within 24 h after initiation of cultures. The liberated cells were mostly round and were either granulocytes or hyalinocytes. Fibroblast-like cells were also observed. Our results showed that proliferation of epithelial cells from mantle tissue was maximum in seawater medium (7.4x104 cells ml-1), followed by L-15 medium (2.55x104 cells ml-1). Average cell size in seawater medium was 10.72 μm and that in L-15 and M199 media was 8.56 and 6.39 μm, respectively. Adherent cells were also more prominent and higher in number in seawater medium. Supplementation of culture media with 10% FCS and 0.1% yeast extract improved both cell proliferation and cell size in all the three culture media. Four concentrations of 0.1% yeast extract (@ 50 μl, 75 μl, 100 μl, 150 μl ml-1 medium) were tested in the present study and best results were obtained with 100 μl ml-1, with respect to both cell counts and size

    Structures of orthorhombic lysozyme grown at basic pH and its low-humidity variant

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