2,466 research outputs found
Mechanism of Seasonal Arctic Sea Ice Evolution and Arctic Amplification
Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents-Kara seas. Excessive turbulent heat flux through the sea surface exposed to air due to sea ice reduction warms the atmospheric column. Warmer air increases the downward longwave radiation and subsequently surface air temperature, which facilitates sea surface remains to be free of ice. This positive feedback mechanism is not clearly observed in the Laptev, East Siberian, Chukchi, and Beaufort seas, since sea ice refreezes in late fall (November) before excessive turbulent heat flux is available for warming the atmospheric column in winter. A detailed seasonal heat budget is presented in order to understand specific differences between the Barents-Kara seas and Laptev, East Siberian, Chukchi, and Beaufort seas
Quantum Creation of Black Hole by Tunneling in Scalar Field Collapse
Continuously self-similar solution of spherically symmetric gravitational
collapse of a scalar field is studied to investigate quantum mechanical black
hole formation by tunneling in the subcritical case where, classically, the
collapse does not produce a black hole.Comment: t clarification of the quantization method in Sec. IV, version to
appear in PR
Interaction of Na+ Ion With the Solvated Gramicidin A Transmembrane Channel
A 6-12-1 atom-atom pair potential for the interaction of a Na+ion with gramicidin A (GA) has been derived from ab initio SCF calculations on the intermolecular interaction energies between one Na+ion and GA molecular fragments. This potential has been used to obtain iso-energy maps, which in turn provide an energy profile of the Na+ion in the GA channel. We have applied this potential in Monte Carlo simulations in order to obtain i) the number of water molecules which can be placed inside the GA channel and ii) the hydration structures of the GA channel in the presence of one Na+ion
Interaction of Na+ Ion With the Solvated Gramicidin A Transmembrane Channel
A 6-12-1 atom-atom pair potential for the interaction of a Na+ion with gramicidin A (GA) has been derived from ab initio SCF calculations on the intermolecular interaction energies between one Na+ion and GA molecular fragments. This potential has been used to obtain iso-energy maps, which in turn provide an energy profile of the Na+ion in the GA channel. We have applied this potential in Monte Carlo simulations in order to obtain i) the number of water molecules which can be placed inside the GA channel and ii) the hydration structures of the GA channel in the presence of one Na+ion
Renormalized Thermodynamic Entropy of Black Holes in Higher Dimensions
We study the ultraviolet divergent structures of the matter (scalar) field in
a higher D-dimensional Reissner-Nordstr\"{o}m black hole and compute the matter
field contribution to the Bekenstein-Hawking entropy by using the Pauli-Villars
regularization method. We find that the matter field contribution to the black
hole entropy does not, in general, yield the correct renormalization of the
gravitational coupling constants. In particular we show that the matter field
contribution in odd dimensions does not give the term proportional to the area
of the black hole event horizon.Comment: Final Revision Form as to be published in Physical Review D, ReVTeX,
No Figure
Remarks on Renormalization of Black Hole Entropy
We elaborate the renormalization process of entropy of a nonextremal and an
extremal Reissner-Nordstr\"{o}m black hole by using the Pauli-Villars
regularization method, in which the regulator fields obey either the
Bose-Einstein or Fermi-Dirac distribution depending on their spin-statistics.
The black hole entropy involves only two renormalization constants. We also
discuss the entropy and temperature of the extremal black hole.Comment: 14 pages, revtex, no figure
The effect of prior healthcare employment on the wages of registered nurses
© 2016 The Author(s).Background: The proportion of registered nurses (RNs) with employment in health-related positions before their initial RN education has increased in the past two decades. Previous research found that prior health-related employment i
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