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Kumar C.S.,Government Holkar Science College
Disaster Advances

Topographical maps are indispensable tools for geologists, geographers, foresters, civil engineers, military personnel etc. The process of finding the sheet numbers for irregular polygons like district boarders, watershed boundaries etc. is bit tedious and cumbersome. With the launching of websites like Google Earth and ISRO Bhuvan, finding the latitudes and longitudes of the points and areas of interest has become very easy. Further geo-referenced data in popular GIS software formats are also available from other sources. Recently Survey of India has brought out Open Series Maps (OSMs) on WGS-84 Datum, which have slightly different numbering system than that of the Topographical maps on Everest Datum. Keeping this in mind, an interactive computer programme has been developed for quick and accurate calculation of number of both Topographical Maps and OSMs published by Survey of India. The data input and output are compatible with popular GIS file formats like shape and KML. Source

Okram G.S.,UGC-DAE Consortium for Scientific Research | Kaurav N.,Government Holkar Science College
Journal of Applied Physics

Nanocrystalline copper (NC-Cu) of average particle size (D) ranging from 29 to 55 nm was prepared using the polyol method. The compacted pellets of these nanoparticles were investigated using electrical resistivity (ρn) and thermopower (Sn) measurements in the temperature range from 5 to 300 K. The observed electrical resistivity and thermopower data for all the samples are typical of a good metal and the ρn(T) data are analyzed in the framework of the Bloch-Grüneisen theory. Our analysis indicates systematic departure from the bulk property for NC-Cu samples, decreasing effective Debye temperature, exponential decay of both the residual resistivity ratio (RRR) and the temperature coefficient of resistivity [α = (1/ρ)dρ/dT] as D decreases, yet the Boltzmann theory of electron transport still holds true (kFl ≫ 1). Further, the validity of the Nordheim-Gorter rule is also discussed. The temperature dependence of S n is found to be quite sensitive as compared to bulk thermopower SBulk behavior, revealing the evolution of Sn and exhibiting a significant enhancement of the phonon drag peak as D decreases. The present findings overall suggest the significant influence of the grain boundaries, surface atoms, and phonon confinement. © 2011 American Institute of Physics. Source

Pressure-induced structural aspects of ZnS-type (B3) to NaCl-type (B1) structure in XC (X = Si, Ge, Sn and Pt) compounds are presented. An effective interionic interaction potential with long-range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction up to second-neighbor ions within the Hafemeister and Flygare approach with modified ionic charge is developed. Particular attention is devoted to evaluate the vdW coefficients following the Slater-Kirkwood variational method, as both the ions are polarizable. Our results on vast volume discontinuity in pressure volume phase diagram identify the structural phase transition from B3 to B1 structure. The estimated value of the phase transition pressure (Pt) and the magnitude of the discontinuity in volume at the transition pressure are consistent as compared to the reported data. The variations of elastic constants with pressure follow a systematic trend identical to that observed in other compounds of ZnS and NaCl-type structure family and the Born relative stability criteria are valid in XC compounds. © 2013 The Royal Swedish Academy of Sciences. Source

Varshney D.,Devi Ahilya University | Mansuri I.,Devi Ahilya University | Kaurav N.,Government Holkar Science College | Lung W.Q.,National Dong Hwa University | Kuo Y.K.,National Dong Hwa University
Journal of Magnetism and Magnetic Materials

The effect of Ce-doping on structural, magnetic, electrical and thermal transport properties in hole-doped manganites La 0.7-xCe xCa 0.3MnO 3 (0.0≤x≤0.7) is investigated. The structure of the compounds was found to be crystallized into orthorhombically distorted perovskite structure. dc Susceptibility versus temperature curves reveal various magnetic transitions. For x≤0.3, ferromagnetic regions (FM) were identified and the magnetic transition temperature (T C) was found to be decreasing systematically with increasing Ce concentration. The electrical resistivity ρ(T) separates the well-define metal-semiconducting transition (T MS) for low Ce doping concentrations (0.0≤x≤0.3) consistent with magnetic transitions. For the samples with 0.4≤x≤0.7, ρ(T) curves display a semiconducting behavior in both the high temperature paramagnetic (PM) phase and low temperature FM or antiferromagnetic phase. The electron-phonon and electron-electron scattering processes govern the low temperature metallic behavior, whereas small polaron hopping model is found to be operative in PM phases for all samples. These results were broadly corroborated by thermal transport measurements for metallic samples (x≤0.3) in entire temperature range we investigated. The complicated temperature dependence of Seebeck coefficient (S) is an indication of electron-magnon scattering in the low temperature magnetically ordered regime. Specific heat measurements depict a broadened hump in the vicinity of T C, indicating the existence of magnetic ordering and magnetic inhomogeneity in the samples. The observation of a significant difference between ρ(T) and S(T) activation energies and a positive slope in thermal conductivity κ(T) implying that the conduction of charge carriers were dominated by small polaron in PM state of these manganites. © 2012 Elsevier B.V. All rights reserved. Source

Kaurav N.,Government Holkar Science College | Lalla N.P.,UGC-DAE Consortium for Scientific Research | Okram G.S.,UGC-DAE Consortium for Scientific Research
Journal of Materials Chemistry C

This is the first report on the critical nature of nanolattice formability of different particle sizes (∼4-10 nm) of monodispersed nickel nanoparticles. They exhibit strikingly hexagonal close-packed (hcp) nanolattices without extra forces whenever trioctylphosphine (TOP) is one of the surfactant(s). This clearly establishes the unique role of nanolattice formability of TOP. The c/a ratios are interestingly identical to those of atomic lattices. An attempt has also been made to explain them based on the balanced attractive and repulsive forces of the surfactant-generated cation-anion pairs on the surface of the nanoparticles. The present findings therefore will provide a far-reaching vista for the fabrication of varieties of natural nanolattices and their understanding on applications in a new paradigm. This journal is © the Partner Organisations 2014. Source

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