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This paper aims to review various techniques used in computational electromagnetism such as the treatment of open problems, helicoidal geometries and the design of arbitrarily shaped invisibility cloaks. This seemingly heterogeneous list is unified by the concept of geometrical transformation that leads to equivalent materials. The practical set‐up is conveniently effected via the finite element method.

The change of coordinates is completely encapsulated in the material properties.

The most significant examples are the simple 2D treatment of helicoidal geometries and the design of arbitrarily shaped invisibility cloaks.

The paper provides a unifying point of view, bridging several techniques in electromagnetism.

This paper investigates new technological devices to be utilised in future optical communications, by means of variational method (FEM) and multipole scattering approach (Rayleigh method). This last one provides interesting asymptotic results in the long‐wavelength limit. The so‐called photonic crystal fibres (PCF) possess radically different guiding properties due to photonic band gap guidance: removing a hole within a macro‐cell leads to a defect state within the gap. In the case of multi‐core PCF, the localised modes start talking to each other which possibly leads to a new generation of multiplexer/demultiplexers.

The purpose of this paper is to present a complete analysis of leaky modes within a microstructured optical fibre (MOF). Some new numerical results illustrating the versatility and accuracy of our approach are to be given.

A method involving both finite elements and perfectly matched layer (PML) is proposed.

A rigorous definition of the leaky modes is proposed that leads to a proof of the validity of the PML approach together with a rule for the choice of the PML parameters.

The choice of parameters associated with the PML are discussed in great detail. The accuracy of the constant of propagation (and especially the imaginary part) are highlighted.

This paper is devoted to the presentation of a new finite element formulation for spectral problems arising in the determination of propagating modes in dielectric waveguides and particularly in optical fibers. As an example, we compute the coupling between two parallel optical wave guides. The originality of the paper lies in the fact that we take into account both the vector character of the problem (no weak coupling assumption) and the unboundness of the domain.

This paper concerns the study of non‐linear effects in optical fibres with a core made of a Kerr type medium. The aim is to propose an algorithm to find spatial solitons, i.e. solutions with a harmonic behaviour in time and along the fibre but with a field distribution in the cross‐section corresponding to a self‐trapped propagation of the electromagnetic field.

The field is supposed to be harmonic in time and along the direction of invariance of the fibre but inhomogeneous in the cross‐section. This modifies the refractive index profile of the fibre (a step‐index one in this study). A scalar model of the fibre, together with the finite element method (that is well suited to deal with inhomogeneous media), is used and a new iterative algorithm is proposed to obtain the non‐linear solutions. An adaptive meshing is necessary to guarantee the accuracy of the model.

The new algorithm converges to self‐coherent solutions that are different from those obtained via a fixed power algorithm. The equivalents both of a fundamental mode and of a second order mode are studied.

The approach acknowledges the findings of the previously known spatial solitons (with a slight modification of the algorithm) together with a new family of solutions. It opens a new field of investigation to understand this whole family of non‐linear solutions as it shows that only a small part of them was known up to now.

Presents the implicit Runge‐Kutta methods as an interesting alternative to Crank‐Nicolson and backward Euler methods to solve differential algebraic systems arising in nonlinear transient magnetodynamic problems. An algorithm for diagonally implicit Runge‐Kutta methods is proposed that requires minor modifications of existing codes.

In this paper, we study a new class of optical fibers to be utilized in future optics and optoelectronics. These so‐called photonic band gap (PBG) waveguides can be classified into a fundamentally different way to all optical waveguides and possess radically different guiding properties due to PBG guidance, as opposed to guidance by total internal reflection.

Relying upon personal interviews with 70 companies, this article offers some conclusions on the nature and scope of international marketing research activities. Specifically, the analysis provides a general characterization of such activities and gives specific examples of how companies approach international marketing research. Various indicators of market potential used by companies are also discussed. A categorization of research themes is offered based upon level of company internationalization. Use of various sources of information is discussed. Finally, specific approaches to foreign market opportunity analysis are highlighted and illustrated with company experiences.

The aim of this work was to study the effect of La(NO

)

on the corrosion behavior of sol-gel coating prepared by hydrolysis of 3-glycidoxypropyl)methyldiethoxysilane and 3-aminopropyltriethoxysilane. Generally, galvanized steel is subjected to a hexavalent chromium passivation treatment. Hexavalent chromium passivation is not an environment friendly product and researchers are looking for a suitable alternative for chromium passivation treatment. Some of the potential alternatives are silicate conversion coating or the use of silane-based coatings. In this context, sol-gel coating was investigated as a potential replacement for hazardous hexavalent chromium passivation treatment.

The sol-gel film was deposited on galvanized steel sheet by the dip coating method. The molecular vibration and chemical properties of sol-gel solution and coated films were obtained by infrared spectroscopy. Images from a scanning electron microscope were obtained to characterize the morphology of the film. The corrosion resistance of the coated samples was evaluated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves and salt spray tests.

The results indicated that La(NO

)

-doped coatings were more resistance to corrosion than undoped coating. The coating doped with 0.5 per cent La(NO

)

offered improved corrosion protection due to the inhibitive action of the La3+ ion.

This result can provide a reference for the development of chromium-free passivation for galvanized sheeting.