Deep-core photoionization of krypton atoms below and above the 1s ionization threshold

AbstractElectronic relaxation of atomic Kr below and above the 1s ionization threshold is investigated experimentally using hard x-ray photoelectron spectroscopy. The experimental results are interpreted with the aid of relativistic Dirac-Fock calculations. The 1s orbital core-hole lifetime is extracted and the satellite’s structures accompanying the photoelectron main line are assigned. Auger spectra recorded below and above the K edge are also investigated. In particular, the Auger cascade originating from vacancies of different origin in the L shell is analyzed in great detail. Competition between radiative KL versus nonradiative KLL Auger emission is emphasized.Abstract Electronic relaxation of atomic Kr below and above the 1s ionization threshold is investigated experimentally using hard x-ray photoelectron spectroscopy. The experimental results are interpreted with the aid of relativistic Dirac-Fock calculations. The 1s orbital core-hole lifetime is extracted and the satellite’s structures accompanying the photoelectron main line are assigned. Auger spectra recorded below and above the K edge are also investigated. In particular, the Auger cascade originating from vacancies of different origin in the L shell is analyzed in great detail. Competition between radiative KL versus nonradiative KLL Auger emission is emphasized

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Not AvailableThe study deals with the first comprehensive spatial distribution and area estimate of seagrass patches of India with a standardized methodology. Seagrass patches are mainly located in Palk Bay – Gulf of Mannar (Tamil Nadu), Gulf of Kachchh (Gujarat), Chilika Lake (Odisha) and Islands of Andaman & Nicobar and Lakshadweep. Medium resolution satellite images of Landsat 8 OLI were subjected to radiometric, atmospheric and water column correction prior to digital classification and contextual editing. Total estimated seagrass area amounts to 516.59 km2 of which Palk Bay and Gulf of Mannar of Tamil Nadu together contribute to 398.81 km2. Overall classification accuracy for the six sites studied, ranged between 64% (Lakshadweep Islands) and 83.5% (Palk Bay). This suggests that for surveillance studies of homogeneous seagrass meadows with low interspersion of other benthic units such as corals, seaweeds etc., digital mapping using medium resolution data sets with mandatory attenuation correction procedures is suitable. The results of this study and the related area statistics were accepted as a baseline at national level for the delineation of Ecologically Sensitive Areas (ESA) and in the formulation of its conservation strategies. For a cursory appraisal of the status of major seagrass regions, a matrix representation of its locational occurrence and habitat characteristics is provided.Not Availabl

Thermal, calorimetric and crystallisation behaviour of polypropylene/jute yarn bio-composites fabricated by commingling technique

Commingled biocomposites based on polypropylene/jute yarns were prepared using commingling technique. The thermal and calorimetric behaviour of these commingled composites were studied with respect to fibre content and various chemical treatments. The thermal stability of the composites was found to be in between that of jute fibre and neat polypropylene (PP). Different chemical treatments increased the thermal stability of the composites due to increased interfacial adhesion between the matrix and reinforcement. Jute yarn acts as nucleating agents and favours the process of crystallisation thereby increasing the crystallisation temperature. Chemical treatments further increased the crystallisation temperature as a result of better interfacial adhesion between jute yarn and PP matrix. The close proximity of jute yarns weakens the mechanical bonds between PP molecules resulting in marginal lowering of melting temperatures. Polarized optical microscopic studies revealed the formation of transcrystalline layer around the jute fibre after 6 h.</p