Association between exposure to electromagnetic fields from high voltage transmission lines and neurobehavioral function in children.

Background: Evidence for a possible causal relationship between exposure to electromagnetic fields (EMF) emitted by high voltage transmission (HVT) lines and neurobehavioral dysfunction in children is insufficient. The present study aims to investigate the association between EMF exposure from HVT lines and neurobehavioral function in children.

Methods: Two primary schools were chosen based on monitoring data of ambient electromagnetic radiation.

A waveguide reflector based on hybrid one-dimensional photonic crystal waveguides with a semi-cylinder defect.

A hybrid one-dimensional photonic crystal waveguide--a slab waveguide surrounded by one-dimensional photonic crystal with omnidirectional reflection bands, is presented; the transmission/reflection characteristics of the hybrid waveguides with a semi-cylinder defect are investigated by numerical simulation. Calculated results indicate that, as long as the semi-cylinder radius is appropriately adjusted, the high reflectance of 96.7%, nearly zero transmittance and low loss of 3% can be observed.

Flexible photonic crystal waveguide branches with arbitrary branching angles.

A fundamental Y branch based on a flexible photonic crystal waveguide is presented. By combining this fundamental Y branch with flexible waveguides, flexible waveguide branches with arbitrary branching angles are constructed. Numerical simulations of these branches indicate that without any structural optimization, near-complete transmission is observed within a wide frequency band.

Study on a compact flexible photonic crystal waveguide and its bends.

The dispersion and transmission characteristics of transverse electric modes of a flexible photonic crystal waveguide are investigated by numerical simulation. Calculated results indicate that for arbitrary-angle bends of this waveguide with very small curved radii no more than two wavelengths, a very high transmission (>98.5%) is observed for a broad enough bandwidth.

On the existence of localized shear horizontal acoustic waves in a piezoelectric plate with two semi-infinite same/different coatings.

In this paper, the existence theorem of localized shear horizontal acoustic waves in a piezoelectric plate with two semi-infinite same/different coatings is established. Some properties of the waves in the waveguide structures are also discussed. The results show that the waveguides have some advantages and provide more choice for the designs of acoustic devices.

Numerical calculation of a converging vector electromagnetic wave diffracted by an aperture using Borgnis potentials. II. Application to the study of focal shift.

Focal shift of the converging spherical wavefront light diffracted by a circular aperture is numerically studied with the method of calculating the vector diffractive field by using Borgnis potentials given in Part I [J. Opt. Soc.

Numerical calculation of a converging vector electromagnetic wave diffracted by an aperture by using Borgnis potentials. I. General theory.

A method is proposed, on the basis of the vector electromagnetic theory, for the numerical calculation of the diffraction of a converging electromagnetic wave by a circular aperture by using Borgnis potentials as auxiliary functions. The diffraction problem of vector electromagnetic fields is simplified greatly by solving the scalar Borgnis potentials. The diffractive field is calculated on the basis of the boundary integral equation, taking into consideration the contribution of the field variables on the diffraction screen surface, which is ignored in the Kirchhoff assumption.

Simulation of topographic images and artifacts in illumination-mode scanning-near-field optical microscopy.

Scanning images in illumination-mode, scanning-near-field optical microscopy (SNOM) are numerically studied by the boundary element method based on rigorous vector electromagnetic theory. Computation results of constant-height and constant-distance images for samples with different topographic features are presented. Effects of the polarization of the input light and the optical parameters of samples on the resolution of SNOM are discussed.

Vector near-field calculation of scanning near-field optical microscopy probes using Borgnis potentials as auxiliary functions.

A new boundary integral equation method for solving the near field in three-dimensional vector form in scanning near-field optical microscopy (SNOM) using Borgnis potentials as auxiliary functions is presented. A boundary integral equation of the electromagnetic fields, expressed by Borgnis potentials, is derived based on Green's theorem. The harmonic expansion in rotationally symmetric SNOM probe--sample systems is studied, and the three-dimensional electromagnetic problem is partly simplified into a two-dimensional one.

Shear-horizontal acoustic wave propagation in piezoelectric bounded plates with metal gratings.

In this paper, shear-horizontal (SH) acoustic wave propagation in metal gratings deposited on piezoelectric bounded plates is investigated. The spectral characteristics of the electromechanical coupling coefficient are studied first, which are very important for acoustic wave device designs. And, an effective mathematic method based on even- and odd base functions is also presented for overcoming the large frequency thickness product problem.

New technique for in-situ measurement of ammonia distribution in industrial combustion systems.

A new technique of a laser gas monitoring system with a linear Charge-Coupled Device (CCD) has been developed to measure in-situ distribution of ammonia concentrations at various temperatures. The concentration is determined by measuring absorption with a tunable 13CO2 waveguide laser that is frequency modulated between two adjacent emission lines. One line coincides with a strong ammonia absorption line, while the other is used as a reference.