4,706 research outputs found

    Interface superconductivity in La1.48_{1.48}Nd0.4_{0.4}Sr0.12_{0.12}CuO4_{4}/La1.84_{1.84}Sr0.16_{0.16}CuO4_{4} bilayers

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    We identify a distinct superconducting phase at the interface of a La1.48_{1.48}Nd0.4_{0.4}Sr0.12_{0.12}CuO4_4 (LNSCO)/La1.84_{1.84}Sr0.16_{0.16}CuO4_4 (LSCO) epitaxial bilayer system using ac screening measurements. A model based on inter-diffusion of quasiparticles and condensate at the interface yields a thickness of \sim 25 nm for the interfacial layer. Two-dimensional superconductivity of the interface layer appears to be governed by Kosterlitz-Thouless-Berezinskii transition. A parallel magnetic field suppresses the superconducting transition temperature of this layer with a pair breaking parameter α\alpha varying as H2H^2

    Some Superstitious Botanical Folklore of Different Tribes of North Cachar Hills, Assam (Northeast India)

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    The district of North Cachar Hills of Assam, one of the most biodiverse regions of the world is endowed with different tribes each with their own traditions, customs and method of healing. Northeast India has been a paradise for ethnobotanical research but the district of N.C.Hills, with its vast ethnobotanical wealth is virtually unexplored. The present study documents for the first time, the superstitious folkloric uses of plants to treat ailments among the different tribes. 16 species of plants has been identified with details on its method of use, disease, parts used, local name and growth forms. The study was conducted through informal interviews after prior informed consent. The study reflects a rich traditional knowledge base of the tribe on ethnomedicine with immense potential for a more detailed study with emphasis on its pharmacological aspects

    Traditional Tribal Knowledge and Status of Some Rare and Endemic Medicinal Plants of North Cachar Hills District of Assam, Northeast India

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    An ethnobotanical survey carried out in the district of North Cachar hills, Assam, North East India during the period of February 2006 – November 2006, has revealed 34 species of plants to be threatened in several parts of the country, and in the district itself. More than 6 species of plants are included in the red Data Book of Indian Plants, 5 numbers of species have already been included in the Red Data List of the IUCN. 13 species documented in the present paper have not been reported about its threat status earlier, but are now threatened in the district. These plants are used in various ways such as, medicinal, wild edibles, ornamentals, building materials and other miscellaneous uses in their daily life. Because of the declining population of species like, Taxus baccata, Renanthera inschootiana, Swertia chirata etc., the area warrants conservation in order to preserve them from extinction. The present paper documents on the botanical name, parts used, local name, and also compares the threat status relative to other regions of the country as per IUCN Guidelines

    Martian M2 peak behaviour in the dayside near-terminator ionosphere during ICMEs

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    The interplanetary coronal mass ejections (ICMEs) can pose significant impacts on the Martian ionosphere, resulting in plasma depletion, variability, and escape to space. However, the connections between the ICMEs and the associated responses of the dayside near-terminator Martian ionospheric M2 peak are not well understood. The present study primarily investigates the behaviour of the ionospheric peak density (Nm) and height (hm) during the passage of ICMEs using observations from the Radio Occultation Science Experiment (ROSE) aboard MAVEN spacecraft. We have selected 8 such ICMEs (during 2017-2022) at Mars from the existing catalogs and studied the ROSE electron density profiles during quiet and disturbed time (ICMEs) for identical solar zenith angle range. We observed the elevation of the M2 peak (hm ~4-16 km) during disturbed time (ICMEs) with a decrease in Nm (0.41-2.8 * 10^10 m-3) in comparison to the quiet time. The present study, for the first time, addressed the influence of ICMEs on the M2 peak parameters (Nm and hm). We have proposed that the development of large vertical pressure gradient and electron temperature enhancement are plausible causes for ionospheric variability. Therefore, the present study provides new insights to understand the peak plasma behaviour in the dayside near-terminator ionosphere during ICMEs

    Structure-function mapping of a heptameric module in the nuclear pore complex.

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    The nuclear pore complex (NPC) is a multiprotein assembly that serves as the sole mediator of nucleocytoplasmic exchange in eukaryotic cells. In this paper, we use an integrative approach to determine the structure of an essential component of the yeast NPC, the ~600-kD heptameric Nup84 complex, to a precision of ~1.5 nm. The configuration of the subunit structures was determined by satisfaction of spatial restraints derived from a diverse set of negative-stain electron microscopy and protein domain-mapping data. Phenotypic data were mapped onto the complex, allowing us to identify regions that stabilize the NPC's interaction with the nuclear envelope membrane and connect the complex to the rest of the NPC. Our data allow us to suggest how the Nup84 complex is assembled into the NPC and propose a scenario for the evolution of the Nup84 complex through a series of gene duplication and loss events. This work demonstrates that integrative approaches based on low-resolution data of sufficient quality can generate functionally informative structures at intermediate resolution

    Feasibility of Formation of Ge1-x-y Six Sny Layers With High Sn Concentration via Ion Implantation

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    By increasing the Sn concentration in Ge1-ySny and Ge1-x-ySixSny systems, these materials can be tuned from indirect to direct bandgap along with increasing electronic and photonic properties. Efforts have been made to synthesize Sn-Ge and Ge-Si-Sn structures and layers to produce lower energy direct bandgap materials. Due to low solid solubility of Sn in Ge and Si-Ge layers, high concentrations of Sn are not achieved by traditional synthesis processes such as chemical vapor deposition or molecular beam epitaxy. Implantation of Sn into Si-Ge systems, followed by rapid thermal annealing or pulse laser annealing, is shown to be an attractive technique for increasing Sn concentration, which can increase efficiencies in photovoltaic applications. In this paper, dynamic ion-solid simulation results are presented. Simulations were performed to determine optimal beam energy, implantation order, and fluence for a multi-step, ion-implantation based synthesis process

    Structural, electrical and magnetic studies of Co:SnO2 and (Co,Mo):SnO2 films prepared by pulsed laser deposition

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    Here we report on the structural, optical, electrical and magnetic properties of Co-doped and (Co,Mo)-codoped SnO2 thin films deposited on r-cut sapphire substrates by pulsed laser deposition. Substrate temperature during deposition was kept at 500 degrees C. X-ray diffraction analysis showed that the undoped and doped films are crystalline with predominant orientation along the [1 0 1] direction regardless of the doping concentration and doping element. Optical studies revealed that the presence of Mo reverts the blue shift trend observed for the Co-doped films. For the Co and Mo doping concentrations studied, the incorporation of Mo did not contribute to increase the conductivity of the films or to enhance the ferromagnetic order of the Co-doped films. (C) 2012 Elsevier B.V. All rights reserved

    Phase growth control in low temperature PLD Co: TiO2 films by pressure

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    This paper reports on the structural and optical properties of Co-doped TiO2 thin films grown onto (0001)Al2O3 substrates by non-reactive pulsed laser deposition (PLD) using argon as buffer gas. It is shown that by keeping constant the substrate temperature at as low as 310 degrees C and varying only the background gas pressure between 7 Pa and 70 Pa, it is possible to grow either epitaxial rutile or pure anatase thin films, as well as films with a mixture of both polymorphs. The optical band gaps of the films are red shifted in comparison with the values usually reported for undoped TiO2, which is consistent with n-type doping of the TiO2 matrix. Such band gap red shift brings the absorption edge of the Co-doped TiO2 films into the visible region, which might favour their photocatalytic activity. Furthermore, the band gap red shift depends on the films' phase composition, increasing with the increase of the Urbach energy for increasing rutile content. (C) 2012 Elsevier B.V. All rights reserved
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