scholarly journals Meridional flow of grounded abyssal currents on a sloping bottom in spherical geometry

2012 ◽  
Author(s):  
G. E. Swaters
Keyword(s):  
Spherical Geometry ◽  
Meridional Flow ◽  
Abyssal Currents ◽  
Sloping Bottom

The Meridional Flow of Source-Driven Abyssal Currents in a Stratified Basin with Topography. Part I: Model Development and Dynamical Properties

2006 ◽  
Vol 36 (3) ◽  
pp. 335-355 ◽  
Author(s):  
Gordon E. Swaters
Keyword(s):  
Baroclinic Instability ◽  
Model Development ◽  
Finite Amplitude ◽  
Meridional Flow ◽  
Gravity Models ◽  
Western Boundary ◽  
Reduced Gravity ◽  
The Stability ◽  
Abyssal Currents ◽  
Variable Topography

Abstract The equatorward flow of source-driven grounded deep western boundary currents within a stratified basin with variable topography is examined. The model is the two-layer quasigeostrophic (QG) equations, describing the overlying ocean, coupled to the finite-amplitude planetary geostrophic (PG) equations, describing the abyssal layer, on a midlatitude β plane. The model retains subapproximations such as classical Stommel–Arons theory, the Nof abyssal dynamical balance, the so-called planetary shock wave balance (describing the finite-amplitude β-induced westward propagation of abyssal anomalies), and baroclinic instability. The abyssal height field can possess groundings. In the reduced gravity limit, a new nonlinear steady-state balance is identified that connects source-driven equatorward abyssal flow (as predicted by Stommel–Arons theory) and the inertial topographically steered deep flow described by Nof dynamics. This model is solved explicitly, and the meridional structure of the predicted grounded abyssal flow is described. In the fully baroclinic limit, a variational principle is established and is exploited to obtain general stability conditions for meridional abyssal flow over variable topography on a β plane. The baroclinic coupling of the PG abyssal layer with the QG overlying ocean eliminates the ultraviolet catastrophe known to occur in inviscid PG reduced gravity models. The baroclinic instability problem for a constant-velocity meridional abyssal current flowing over sloping topography with β present is solved and the stability characteristics are described.

FEW-PARTICLE ANYON EXCITON: EXACT SOLUTIONS

2003 ◽  
Vol 02 (06) ◽  
pp. 461-468
Author(s):  
D. G. W. PARFITT ◽  
M. E. PORTNOI
Keyword(s):  
Exact Solutions ◽  
Finite Size ◽  
Spherical Geometry ◽  
Planar Geometry ◽  
Quantum Liquid ◽  
Dimensional Electron ◽  
Adequate Description ◽  
Exciton Model ◽  
Finite Size Effects ◽  
Dimensional Electron Gas

The anyon exciton model, which describes an exciton against the background of an incompressible quantum liquid, is generalized to the case of an arbitrary number of anyons. Some mathematical aspects of this quantum-mechanical few-particle problem are considered and several exact solutions are obtained. The four-particle case is also considered in the classical limit in both planar and spherical geometries. Such a classical approach gives an adequate description of an anyon exciton at large separation between the valence hole and the two-dimensional electron gas. It is shown that in this limit in a planar geometry the anyon exciton is always energetically more favorable than a charged anyon ion. This indicates that the appearance of fractionally-charged anyon ions reported in recent numerical calculations is an artefact apparently caused by finite-size effects in a spherical geometry.

Viscous dissipation of Rankine vortex profile in zero meridional flow

2005 ◽  
Vol 21 (6) ◽  
pp. 550-556 ◽  
Author(s):  
Yasser Aboelkassem ◽  
Georgios H. Vatistas ◽  
Nabil Esmail
Keyword(s):  
Viscous Dissipation ◽  
Meridional Flow ◽  
Rankine Vortex

Carbon nanomaterials based on interpolyelectrolyte complex lignosulfonate-chitosan

Holzforschung ◽  
2019 ◽  
Vol 73 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Olga Brovko ◽  
Irina Palamarchuk ◽  
Konstantin Bogolitsyn ◽  
Nikolay Bogdanovich ◽  
Artem Ivakhnov ◽  
...  
Keyword(s):  
Specific Surface ◽  
Nitrogen Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Nanomaterials ◽  
Electron Pair ◽  
Spherical Geometry ◽  
Processing Conditions ◽  
Interpolyelectrolyte Complex ◽  
New Approach

AbstractA new approach to the formation of “fullerene-like” carbon-nitrogen carbogels based on the interpolyelectrolyte complex lignosulfonate-chitosan (IPEC LSNa-CT) was developed. It was established that carbogel maintained the morphology of the precursor complex, i.e. the spherical geometry and the particle size of its main fractions (40–55 nm) were stored in the carbonizate. The influence of pyrolysis (Py) temperature was studied in the range of 500–1000°C on the structure of carbonizate. Carbogels obtained under different processing conditions have a well-developed microporous structure. The specific surface area of carbogels reduced with increasing Py temperature according to their nitrogen content. The maximum specific surface area (438.3 m2g−1) corresponds to the carbogel obtained at 600°C, while the maximum nitrogen content of this sample is 4.4%. The internal porosity of the material and the volume of supermicropores are reduced with increasing Py temperature due to the accumulation of double and triple carbon bonds in the carbogel. Apparently, the structure-forming N-atoms participate in the formation of condensed nitrogen-containing and cyclic structures as a donor of the electron pair and as such they accelerate the carbonization process.

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