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

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

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

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

Re-visiting insecticide resistance status in Anopheles gambiae from Côte d'Ivoire: a nation-wide informative survey.

Insecticide resistance constitutes a major threat that may undermine current gain in malaria control in most endemic countries. National Malaria Control Programmes (NMCPs) need as much information as possible on the resistance status of malaria vectors and underlying mechanisms in order to implement the most relevant and efficient control strategy. Bioassays, biochemical and molecular analysis were performed on An. gambiae collected in six sentinel sites in Côte d'Ivoire. The sites were selected on the basis of their bioclimatic status and agricultural practices. An. gambiae populations across sites showed high levels of resistance to organochloride, pyrethroid and carbamate insecticides. The kdr and ace-1(R) mutations were detected in almost all sentinel sites with mosquitoes on the coastal and cotton growing areas mostly affected by these mutations. At almost all sites, the levels of detoxifying enzymes (mixed-function oxidases (MFOs), non-specific esterases (NSE) and glutathione-S-transferases (GSTs)) in An. gambiae populations were significantly higher than the levels found in the susceptible strain Kisumu. Pre-exposure of mosquitoes to PBO, an inhibitor of MFOs and NSEs, significantly increased mortality rates to pyrethroids and carbamates in mosquitoes but resistance in most cases was not fully synergised by PBO, inferring a residual role of additional mechanisms, including kdr and ace-1 site insensitivity. The large distribution of resistance in Côte d'Ivoire raises an important question of whether to continue to deploy pyrethroid-based long-lasting insecticidal nets (LLINs) and insecticide residual spraying (IRS) towards which resistance continues to rise with no guarantee that the level of resistance would not compromise their efficacy. Innovative strategies that combine insecticide and synergists in LLINs or spatially LLIN and an effective non-pyrethroid insecticide for IRS could be in the short term the best practice for the NMCP to manage insecticide resistance in malaria vectors in Côte d'Ivoire and other endemic countries facing resistance