Crossed conductance in FSF double junctions: role of out-of-equilibrium populations

We discuss a model of Ferromagnet / Superconductor / Ferromagnet (FSF) double junction in which the quasiparticles are not in equilibrium with the condensate in a region of the superconductor containing the two FS contacts. The role of geometry is discussed, as well as the role of a small residual density of states within the superconducting gap, that allows a sequential tunneling crossed current. With elastic quasiparticle transport and the geometry with lateral contacts, the crossed conductances in the sequential tunneling channel are almost equal in the normal and superconducting phases, if the distance between the FS interfaces is sufficiently small. The sequential tunneling and spatially separated processes (the so-called crossed Andreev reflection and elastic cotunneling processes) lead to different signs of the crossed current in the antiparallel alignment for tunnel interfaces.Comment: 8 pages, 4 figure

The effects of restraint on uptake of radioactive sulfate in the salivary and gastric secretions of rats with pyloric ligation

The effects of restraint on the amount of nondialysable radioactive sulfate in the gastric wall and the gastric juice and saliva were investigated. It was found that restraint provokes a significant decrease in salivary radioactive sulfate. This, in turn, is responsible for the decrease of sulfate in the gastric contents observed under these conditions in rats with pyloric ligation. Esophageal ligation associated with this prevents passage of saliva and lowers the amount of radioactive sulfate in the gastric juice. Restraint causes then an increase in the amount of sulfate in the gastric juice, the value observed being very much lower than that of rats with a free esophagus. At the level of the gastric wall, the change observed during restraint does not reach a significant threshold

Why some fields might be rectangular: an exploration of agricultural landscapes between pre-capitalist and capitalist modes of production

This article is a preliminary investigation of possible spatial form which starts by rejecting the idea that spatial theory can be built from assumptions of isomorphism. It examines spatial form in high potential ridge valley areas which are densely populated, and identifies the transition in land configuration for pre-capitalist to capitalist modes of production. In building the argument simple geometric patterns that differentiate from the model are postulated. The basic drivers of the differing spatial systems are essentially the superstructural legal conditions which are postulated as a moving from communal, customary law to individual statutory property rights

Pacific Solitaire

page 14

Numerical Simulation of Baroclinic Jovian Vortices

We examine the evolution of baroclinic vortices in a time-dependent, nonlinear numerical model of a Jovian atmosphere. The model uses a normal-mode expansion in the vertical, using the barotropic and first two baroclinic modes. Results for the stability of baroclinic vortices on an f plane in the absence of a mean zonal flow are similar to results of Earth vortex models, although the presence of a fluid interior on the Jovian planets shifts the stability boundaries to smaller length scales. The presence of a barotropic mean zonal flow in the interior stabilizes vortices against instability and significantly modifies the finite amplitude form of baroclinic instabilities. The effect of a zonal flow on a form of barotropic instability produces periodic oscillations in the latitude and longitude of the vortex as observed at the level of the cloud tops. This instability may explain some, but not all, observations of longitudinal oscillations of vortices on the outer planets. Oscillations in aspect ratio and orientation of stable vortices in a zonal shear flow are observed in this baroclinic model, as in simpler twodimensional models. Such oscillations are also observed in the atmospheres of Jupiter and Neptune. The meridional propagation and decay of vortices on a β plane is inhibited by the presence of a mean zonal flow. The direction of propagation of a vortex relative to the mean zonal flow depends upon the sign of the meridional potential vorticity gradient; combined with observations of vortex drift rates, this may provide a constraint on model assumption for the flow in the deep interior of the Jovian planets