Superconducting Mechanism through direct and redox layer doping in Pnictides

The mechanism of superconductivity in pnictides is discussed through direct doping in superconducting FeAs and also in charge reservoir REO layers. The un-doped SmFeAsO is charge neutral SDW (Spin Density Wave) compound with magnetic ordering below 150 K. The Superconducting FeAs layers are doped with Co and Ni at Fe site, whereas REO layers are doped with F at O site. The electron doping in SmFeAsO through Co results in superconductivity with transition temperature (Tc) maximum up to 15 K, whereas F doping results in Tc upto 47 K in SmFeAsO. All these REFe/Co/NiAsO/F compounds are iso-structural to ZrCuSiAs structure. The samples are crystallized in a tetragonal structure with space group P4/nmm. Variation of Tc with different doping routes shows the versatility of the structure and mechanism of occurrence of superconductivity. It seems doping in redox layer is more effective than direct doping in superconducting FeAs layer.Comment: 4 Pages text + Figs: ([email protected]

Multiband Operation of Microstrip Antenna

The effect of proximity and aperture coupling on the resonance behavior of the microstrip antenna is presented. With proximity coupling the antenna resonates with two bands having bandwidths of 16.75% and 35.58%.When the same antenna is fed by aperture coupling, three bands occur with bandwidths of 44.3%, 4.75% and 53.43%. Further when the H-slot is replaced with a dumbbell slot all the three bands merge to give single band of 91.43% with a peak gain of 10.23dB while retaining the broadside radiation characteristics. The design concept is presented and experimental results discussed

Anticoagulant induced spontaneous spinal epidural hematoma, conservative management or surgical intervention—A dilemma?

AbstractSpontaneous spinal epidural hematoma (SSEH) is a rare cause of cord compression. SSEH with neurological deficit is an emergency situation that is commonly considered an indication for emergency surgical decompression. We describe a patient with SSEH who recovered clinically and radiologically with conservative treatment. A 25-year-old hypertensive male presented with acute onset back pain followed by asymmetrical paraparesis. He had sensory level at D9 dermatome with preserved bladder and bowel functions. He was taking anticoagulants for deep venous thrombosis of the left lower limb. Surgery was deferred because of the deranged coagulation profile. He was managed conservatively with correction of coagulopathy. After 3 days, he recovered significantly. Repeat neuroimaging revealed significant resolution of epidural hematoma. The conservative approach can be considered for selected patients who are unsuitable for early surgical intervention, those with stable neurological status [American Spinal Injury Association (ASIA) Scale E], or those in whom early recovery of function has been initiated with ASIA Scale C or D. Neurological status at presentation and suitability for surgical intervention seem to be important determinants of the type of therapeutic intervention

Vegetation condition index pattern (2002-2007) over Indian agro-climate regions, using of GIS and SPOT sensor NDVI data

This study describes the Vegetation Condition Index in the near-real-time with help of SPOT based Normalized Difference Vegetation Index (NDVI) for Agro climatic-region of India and gave the development pattern in last six year (2002-2007) over the study area of India using decadal time data set from SPOT satellite sensor for 2002-2007 time periods. The each Agro-climatic region of study, 1°x1° degree in area, part of India agro-climate regions, has been taken for analysis using remote sensing and Geographical Information System (RS and GIS)methods, SPOT satellite sensor NDVI data, and from processed data set (geo-referenced data set), cut out 1°x1° degree of area by preparing a layers representing Agro-climatic region of India as base mapping units (BMU),The results indicated that NDVI index is only water stress over vegetation while VCI is an appropriate index for vegetation pattern monitoring over study area. As satellite observations provide better spatial and temporal coverage, the VCI based system will provide efficient tools for management of the improvement of agricultural planning. This system will serve as a prototype in the other parts of the world where ground observations are limited or not available

Hydro-chemical Survey and Quantifying Spatial Variations in Groundwater Quality in Coastal Region of Chennai, Tamilnadu, India – a case study

The good quality of groundwater is important for the purpose of future planning and management. The present study has been undertaken to provide an overview on the status of groundwater quality through physicochemical parameters namely pH, alkalinity, total hardness, total dissolved solids, chloride, fluoride, nitrate, phosphate and iron through laboratory analysis. Samples have been collected from seven wells located in Chennai costal region of state Tamilnadu, India. The laboratory-based results shows that the mean value of pH is 7.29, alkalinity (308.57 mg/l), total hardness (285.71 mg/l), chloride (175.71 mg/l), iron (0.71 mg/l), nitrate (13.57 mg/l), phosphorus (2.71 mg/l) and total dissolved solids (924 mg/l), respectively. The geo-database water quality parameters were created in Geographical an Information System. Further, the kriging a geo-statistical method of interpolation is applied to know the health of groundwater in the then-sampled area. This interpolation method has been used to predict spatial distribution physicochemical parameters in the form of contour. Local planners and policy makers may utilize these results for efficient management of groundwater resources in this area

Nanoparticles in the soil environment and their behaviour : An overview

The increasing use of nanoparticles (NPs) in industries, soil and water remediation technologies, potential agricultural uses (e.g. fertilizers) and unintentional releases via air, water and sewage sludge application to the land likely leads to the release of such materials into the environment. The unique properties of NPs, such as high specific surface area, abundant reactive sites on the surface as a consequence of a large fraction of atoms located on the exterior rather than in the interior of NPs, as well as their mobility, could cause environmental hazards orpotentially harm soil health.It could be assumed that NPs may not have a direct influence on plant growth but may be responsible for the influence through indirect mechanisms. Light microscopy of root sections showed that the ZnO particles adsorbed into root tissues and cells and damaged the root tissues. Results from ecotoxicological studies show that certain NPs have effects on organisms under environmental conditions, though mostly at elevated concentrations. Nanominerals and mineral NPs in the environment have been present throughout the evolutionary development of hominids, and our exposure to these through inhalation, ingestion are important foci of nanotoxicology and environmental sciences. The more research on occurrence, characteristics of NPs and their behaviour in environment is needed towards a logical conclusion of the effects of NPs on environment

Effect of DEM data resolution on low relief region sub-watershed boundaries delineating using of SWAT model and DEM derived from CARTOSAT-1 (IRS-P5), SRTM and ASTER

Watersheds are natural integrators of hydrological, biological, and geological processes and as such require an integrated approach to data analysis and modeling, which usually starts delineating accurately a polygon vector layer of watershed boundaries as input. In that way, Garrah sub-watershed in Shahjahanpur district of U.P., India, had been isolated with the objective of evaluate the accuracy of sub-watershed boundaries derived from three different sources: One was delineated by 2.6 m resolution CARTOSAT-1 DEM (IRS-P5) and other two were derived from a 30 m ASTER DEM and a 90 m SRTM DEM, using the Soil and Water Assessment Tool (SWAT) model. In this analysis we found that the accuracy of CARTOSAT-1 DEM is so best for accurate delineation of a sub-watershed in the management of the watershed, and the coarse spatial resolution SRTM DEM (90 m) performed much better and significantly than the high spatial resolution ASTER DEM (30 m) it’s cause of the errors in the ASTER DEM, map algebra was used to define where the “Fill” tool had filled the sinks finding that the errors in the stream network occurred where some especially large fills had occurred. Not only the visual interpretation of the produces figures indicate the SRTM DEM delineated sub-watershed as relatively more accurate from ASTER DEM delineated sub-watershed boundaries, also statistics for the SRTM DEM elevation turned in significantly higher than that of the ASTER DEM. Overall SRTM DEMs offer more precise elevations while, ASTER DEMs offer more details. Therefore, the accuracy of the sub-watershed delineation depends on the first place on the accuracy of the DEM