Results 161 to 170 of about 1,698,158 (202)

Topological definition of ring currents

Physical Chemistry Chemical Physics, 2016
A definition of ring currents in a velocity vector field is proposed according to topological criteria: ring currents are axial vortices confined in, or rotating beyond, a separatrix, i.e., the boundary which marks the limits of the vortex.
openaire   +2 more sources

Current status of contraceptive vaginal rings

Contraception, 2013
Contraceptive vaginal rings (CVR) offer a new, effective contraceptive option, expanding the available choices of hormonal contraception. Various ring prototypes have been evaluated: progestin-only rings and combined progestin-estrogen rings, as well as different combination of progestins and estrogens.
Vivian, Brache, Luis José, Payán, Aníbal, Faundes   +2 more
openaire   +2 more sources

Current inducting techniques for superconducting rings

Journal of Superconductivity, 2005
A procedure has been developed to generate a persistent current in superconducting rings. The basis of the method is a magnetic circuit made of a permanent neodymium-iron-boron magnet and an iron core; the current induced in the superconductor comes only from the energy of the permanent magnet avoiding the power supply.
H. González-Jorge, E. Carballo, J. Peleteiro, G. Domarco   +3 more
openaire   +1 more source

Mesoscopic persistent current in small rings

Physical Review B, 1993
Small normal-metal rings threaded by a constant magnetic flux have been shown to carry a mesoscopic persistent current at low temperatures. The current is a few-electron effect and its sign and amplitude depend on the microscopic configuration of disorder. Assuming a Gaussian current distribution, we characterize the effect by three quantities, the rms
, Riedel, , von Oppen F
openaire   +2 more sources

Photoinduced Charge Currents in Mesoscopic Rings

Physical Review Letters, 2005
The temporal and spatial controllability of charge distribution in submicron structures opens new avenues for potential applications and for the understanding of nonequilibrium processes. Here we suggest a novel way to trigger and control within picoseconds charge currents and magnetic moments in nanoscopic and mesoscopic ring structures by applying ...
A, Matos-Abiague, J, Berakdar
openaire   +2 more sources

Linearized ring current models for the retrieval of π ring current strength in monocycles

Chemical Physics Letters, 2013
Abstract Three different ring current models (RCMs) have been used to study the relationship between the π contribution to parallel NICS scans and the ring current strength for monocycles. The models have been linearized and they have been applied to retrieve the ab initio ring current strengths in a set of 28 organic and inorganic monocycles ...
MONACO, Guglielmo, ZANASI, Riccardo
openaire   +1 more source

Ring Currents in Large [4n + 2]‐Annulenes

ChemInform, 2004
AbstractFor Abstract see ChemInform Abstract in Full Text.
Soncini A., Fowler P. W., Jenneskens L. W.   +2 more
openaire   +3 more sources

The terrestrial ring current

Journal of Geophysical Research, 1964
Several people have computed numerically the magnetic field caused by an axially symmetric body of plasma imbedded in a dipole magnetic field. In the present paper we derive an approximate formula for this magnetic field, without first choosing a particular functional form for the plasma density.
openaire   +1 more source

Dynamic persistent currents in mesoscopic rings

Physical Review Letters, 1991
A dynamic current I w in a mesoscopic ring subjected to a time-dependent external magnetic field H~(t)=H 0 +H w cos(ωt) is calculated in the limit of small Hω using linear-response theory and the supersymmetry method. It is shown that the current Iω remains finite in the limit ω→0 and exceeds currents obtained from thermodynamic considerations. It can
openaire   +2 more sources

Aromaticity and Ring Currents

Chemical Reviews, 2001
J A, Gomes, R B, Mallion
openaire   +2 more sources