A Note on Currents on a Quadratic Surface

Although no explicit general solution is known for the vector integral equation satisfied by the current density vector on a conducting surface, it is shown in the following report that the vector equation can be "scalarized" in the case of a quadratic conducting surface

Transients on a Linear Antenna

[no abstract

A conference on liquidity in frictional markets

This Policy Discussion Paper summarizes the papers that were presented at the Liquidity in Frictional Markets conference in November 2008. The papers, which looked at markets for assets as diverse as houses, bank loans, and electronic funds transfer, all explored that amorphous concept called “liquidity” and how its presence—or absence—affects the economy.Liquidity (Economics) ; Monetary policy ; Payment systems

Propagation of Electromagnetic Waves Along Corrugated Lines

The propagation of electromagnetic waves along an infinite "corrugated surface" is investigated by means of integral equations and Fourier transform techniques. Results are obtained which take into account the finite distance between the corrugations. In the E case, we obtain in quite a natural way results similar to those previously obtained by R. Hurd

Diffraction of a Trapped Wave by a Semi-Infinite Metallic Sheet

[Figure 1; see abstract in PDF for details]. It is a well-known fact that dielectric coated infinite metallic structures such as planes and wires can propagate "surface modes". We are here chiefly concerned with a two-dimensional case. There is no theoretical difficulty in extending our solution to three-dimensional structures. We are dealing here with a grounded dielectric slab of permittivity ε and thickness a. (The case in which the electric wall is replaced by a magnetic one involves only slight modifications.) The half-space over the slab is a dielectric of permittivity 1. E modes and H modes can propagate in the slab. They are the so- called "trapped waves". The number of modes is connected with ε and a. As an example of the treatment of the general case, we shall suppose that a is small enough to propagate only one E mode. Extension to the H case or to the multimode case is obvious. We then suppose (see Fig. 1) that only one mode is propagating, coming from z = +∞. This trapped wave will be diffracted by a semi infinite metallic sheet of zero thickness, which lies on x = d , z < 0. We are mainly interested in reflection and transmission coefficients for the trapped modes, the radiated power, and the far-field pattern

Propagation of Electromagnetic Waves Along Corrugated Lines

The propagation of electromagnetic waves along an infinite "corrugated surface" is investigated by means of integral equations and Fourier transform techniques. Results are obtained which take into account the finite distance between the corrugations. In the E case, we obtain in quite a natural way results similar to those previously obtained by R. Hurd

Diffraction of a Trapped Wave by a Semi-Infinite Metallic Sheet

[Figure 1; see abstract in PDF for details]. It is a well-known fact that dielectric coated infinite metallic structures such as planes and wires can propagate "surface modes". We are here chiefly concerned with a two-dimensional case. There is no theoretical difficulty in extending our solution to three-dimensional structures. We are dealing here with a grounded dielectric slab of permittivity ε and thickness a. (The case in which the electric wall is replaced by a magnetic one involves only slight modifications.) The half-space over the slab is a dielectric of permittivity 1. E modes and H modes can propagate in the slab. They are the so- called "trapped waves". The number of modes is connected with ε and a. As an example of the treatment of the general case, we shall suppose that a is small enough to propagate only one E mode. Extension to the H case or to the multimode case is obvious. We then suppose (see Fig. 1) that only one mode is propagating, coming from z = +∞. This trapped wave will be diffracted by a semi infinite metallic sheet of zero thickness, which lies on x = d , z < 0. We are mainly interested in reflection and transmission coefficients for the trapped modes, the radiated power, and the far-field pattern

Lombalgie chronique, COTOREP et reclassement professionnel en Moselle

Objectifs : Décrire les caractéristiques, la prise en charge, les résultats et le coût d\u27un reclassement professionnel concernant les assurés mosellans lombalgiques chroniques bénéficiant d’un accord de la Commission technique d\u27orientation et de reclassement professionnel (COTOREP). Méthodes : Etude descriptive menée entre août 2000 et mars 2001 dans le cadre d\u27un partenariat avec la COTOREP de Moselle intégrant 48 lombalgiques chroniques pour lesquels la COTOREP a donné en 1995 un accord de pré-orientation ou de reclassement professionnels. Résultats : Le lombalgique pris en charge était un homme jeune, de faible niveau scolaire et professionnel, en rupture avec le milieu du travail et souffrant d\u27une pathologie lombaire invalidante. Sur 32 formations suivies, 24 candidats ont réussi leur examen mais seuls dix diplômés ont trouvé un emploi. Huit diplômés ont trouvé un emploi conforme à la formation apprise. Le taux de reprise du travail était semblable pour les diplômés (10/24) et pour les autres lombalgiques (11/24). Le coût global pour l\u27assurance maladie variait de 25 000 en externat à 39 000 en internat. Conclusion : Devant la faible valeur ajoutée du reclassement professionnel que nous avons constatée, il paraît souhaitable de maintenir le lombalgique chronique dans son emploi en restaurant son rachis, en aménageant son poste de travail et, surtout, en gérant ses peurs et croyances liées au couple lombalgietravail

On Satellite Type Antennas

Using some previous study of the radiation of an antenna over a perfectly conducting sphere, various structures of antennas for space vehicles are discussed theoretically. The currents induced on the sphere are taken into account for the computation of radiation patterns

Electromagnetic Waves on Corrugated Lines: Propagation Constant Measurements

In a previous report [G. Weill, Propagation of Electromagnetic Waves along Corrugated Lines, ASTIA Document AD 115 049] an approximate formula for the constant of propagation has been derived from an exact integral equation. It is the purpose of this report to check experimentally the accuracy of our formula