Exploiting the Earth’s Spherical Geometry to Geolocate Images

Author(s):  
Mike Izbicki ◽  
Evangelos E. Papalexakis ◽  
Vassilis J. Tsotras
Keyword(s):  
2003 ◽  
Vol 02 (06) ◽  
pp. 461-468
Author(s):  
D. G. W. PARFITT ◽  
M. E. PORTNOI

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.


Holzforschung ◽  
2019 ◽  
Vol 73 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Olga Brovko ◽  
Irina Palamarchuk ◽  
Konstantin Bogolitsyn ◽  
Nikolay Bogdanovich ◽  
Artem Ivakhnov ◽  
...  

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.


2006 ◽  
Vol 2 (S239) ◽  
pp. 77-79 ◽  
Author(s):  
Ian W Roxburgh ◽  
Friedrich Kupka

AbstractWe investigate the properties of non-local Reynolds stress models of turbulent convection in a spherical geometry. Regularity at the centre r=0 places constraints on the behaviour of 3rd order moments. Some of the down-gradient and algebraic closure models have inconsistent behaviour at r=0. A combination of down-gradient and algebraic closures gives a consistent prescription that can be used to model convection in stellar cores.


2004 ◽  
Vol 9 (4) ◽  
pp. 399-410
Author(s):  
V. A. Kucher ◽  
X. Markenscoff ◽  
M. V. Paukshto
Keyword(s):  

1963 ◽  
Vol 41 (4) ◽  
pp. 651-663
Author(s):  
N. R. Steenberg

The absorption of radiation in a spherical obstacle composed of rigid spheres has been studied. The result is the absorption cross section of such an obstacle as a function of the free cross section and the number A of the individual spheres and of packing density. It is found that the usual rare-gas formula represents the cross section adequately. The analysis is applied to nuclear data for the absorption of 25-Bev/c protons by nuclei. It is found that for a nuclear radius R = r0A1/3 + δ, where δ is the radius of the nucleon, r0 = 1.17 fermi, δ = 1.05 fermi, and an average nucleon transparency a2 = 0.30 is consistent with the data.


Sign in / Sign up

Export Citation Format

Share Document