1,480 research outputs found

    Role of pairing interaction in neutron rich odd and even Zr nuclei

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    Neutron rich Zr nuclei with number of neutrons between NN= 50 and 82 are investigated in the relativistic mean field approach in co-ordinate space. The resonant levels in the positive energy continuum have been explicitly included in the calculation. Odd nuclei have been treated in the blocking approximation. Our calculation indicates that the dripline for odd mass isotopes is far away from that for the even mass ones. Pairing interaction plays a significant role in stabilizing the even isotopes, thus extending the dripline for them

    Geotechnical Problems of Dam Sites and Their Solution with Reference to the Projects of Eastern India

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    Geotechnical problems of dam construction are associated with adverse geological conditions of the dam site like soft rock, fault, shear zone, joints, weathering, permeable bouldery deposit, soluble rocks, ancient slide etc. In many of the dam sites of eastern India where one or more of such adverse conditions exist, the dam could be safely constructed by treatment of foundation defects. In some cases, however, a new site with less geologic problem was chosen with consequent modification in the project scheme

    Geotechnical Problems of Dam Sites and Their Solution with Reference to the Projects of Eastern India

    Get PDF
    Geotechnical problems of dam construction are associated with adverse geological conditions of the dam site like soft rock, fault, shear zone, joints, weathering, permeable bouldery deposit, soluble rocks, ancient slide etc. In many of the dam sites of eastern India where one or more of such adverse conditions exist, the dam could be safely constructed by treatment of foundation defects. In some cases, however, a new site with less geologic problem was chosen with consequent modification in the project scheme

    Polyfluorene as a model system for space-charge-limited conduction

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    Ethyl-hexyl substituted polyfluorene (PF) with its high level of molecular disorder can be described very well by one-carrier space-charge-limited conduction for a discrete set of trap levels with energy \sim 0.5 eV above the valence band edge. Sweeping the bias above the trap-filling limit in the as-is polymer generates a new set of exponential traps, which is clearly seen in the density of states calculations. The trapped charges in the new set of traps have very long lifetimes and can be detrapped by photoexcitation. Thermal cycling the PF film to a crystalline phase prevents creation of additional traps at higher voltages.Comment: 13 pages, 4 figures. Physical Review B (accepted, 2007

    Neutron Dripline in Odd and Even Mass Calcium and Nickel Nuclei

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    Neutron rich Ca and Ni nuclei have been studied in spherical Relativistic Mean Field formalism in co-ordinate space. A delta interaction has been has been adopted to treat the pairing correlations for the neutrons. Odd nuclei have been treated in the blocking approximation. The effect of the positive energy continuum and the role of pairing in the stability of nuclei have been investigated using the resonant-BCS (rBCS) approach. In Ca isotopes, N=50 is no longer a magic number while in Ni nuclei, a new magic number emerges at N=70. There is a remarkable difference in the relative positions of the drip lines for odd and even isotopes. In Ca isotopes, the last bound even and odd nuclei are found to be 72^{72}Ca and 59^{59}Ca, respectively. In Ni isotopes, the corresponding nuclei are 98^{98}Ni and 97^{97}Ni, respectively. The origin of this difference in relative positions of the dripline in even and odd isotopes in the two chain is traced to the difference in the single particle level structures and consequent modification in the magic numbers in the two elements. Pairing interaction is seen to play a major role. The effect of the width of the resonance states on pairing has also been investigated.Comment: To appear in Physical Review

    Spacetime Dependent Lagrangians and Weak-Strong Duality : Sine Gordon and Massive Thirring Models

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    The formalism of spacetime dependent lagrangians developed in Ref.1 is applied to the Sine Gordon and massive Thirring models.It is shown that the well-known equivalence of these models (in the context of weak-strong duality) can be understood in this approach from the same considerations as described in [1] for electromagnetic duality. A further new result is that all these can be naturally linked to the fact that the holographic principle has analogues at length scales much larger than quantum gravity. There is also the possibility of {\it noncommuting coodinates} residing on the boundaries. PACS: 11.15.-q: 11.10/EfComment: Latex, 16 pages, article shortened, references added, minor typos correcte
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