Structure and diffusion of Ga and As ions in simulated liquid GaAs have been studied in a model containing 3000 ions under periodic boundary conditions via molecular dynamics simulation (MD). The microstructure of systems has been analyzed through partial radial distribution functions (PRDFs), coordination number distributions, bond-angle distributions and interatomic distances. We found that calculated data agree well with the experimental ones. Temperature dependence of these distributions was obtained. Caculations show that liquid GaAs model with a real density at 5.3176 g cm-3 has a distorted tetrahedral network structure with the mean coordination number ZAs-Ga ≈ 4. Diffusion constant D in system has been calculated over temperatures ranged from 5000 K down to 1500 K. Calculations show that the temperature dependence of the diffusion constant D shows an Arrhenius law at relatively low temperatures above the melting point and it shows a power law, D ∼ (T - Tc)γ, at higher temperatures.


The generation of white light from CdS nanoparticles (NPs) illuminated by UV-LED is presented. The synthesis of CdS nanoparticles from the reaction of CdCl2 and the sulfur dissolved in oleylamine in 1:2 mole ratio was used in the preparation of CdS nanocrystalline. The PMMA film doped with CdS nanoparticles was prepared. The generation of white light was found from illumination of the CdS/polymer composite film by UV-LED of power 5 mW at λ = 385 nm. The white light generation mechanism was explaining depending on mixing colors from the illuminated CdS nanoparticles. The surface levels formed in the CdS optical energy band due to nanostructure was estimated from Poisson equation designed for this state. The chromaticity coordinates of the generated white light was measured by the help of photoluminescence (PL) spectrum and the correlated color temperature was found to be about 4000 K.


Electric-field-induced magnetization (EIM) resonant characteristics were investigated in bilayered and trilayered composites. The length resonant EIMs were inspired in both symmetrical and asymmetrical composites and the EIM coefficients were relative to the thickness ratio between PZT and Terfenol-D. The bending resonant EIMs were observed in the bilayered and asymmetrical trilayered composites besides the length resonant EIMs. The symmetrical composites only produced weak bending resonant EIMs even though the composites with two PZT layers connected in parallel enjoyed a much strong electromechanical bending resonance. The results are helpful for the future design of magnetoelectric devices.


The nonuniform energy density distribution of laser pulses leads to nonuniform pressure distribution of sound field on photoacoustic effect, and photoacoustic image would be distorted at the edge of the absorbed optical energy deposit area. In this paper, a new method for compensating the sound field pressure and correcting the photoacoustic image is reported and testified. Distribution of the photoacoustic pressure was measured with a phase-controlled focus array transducer, and the theoretic function of the photoacoustic pressure was extracted by fitting the distribution curve. The compensation weight factor of the photoacoustic pressure defined as a reciprocal of the theoretic function. Photoacoustic images of a simulation sample and an in vivo mouse brain were reconstructed by correcting with the pressure compensation weight factor. The experimental results showed that this method can uniform the contrast distribution and correct the edge distortion of the PA image, suggesting the potential application in vascular imaging.


In this article we have shown that it is possible to use transmission, absorption and reflection spectroscopic data of KClxBr1-x single crystals for the TL (Thermo Luminescence) dosimetry purposes in the spectral range of 250-750 nm. The effects of gamma radiation on KClxBr1-x single crystals were investigated by radiating the samples with a 60Co source and studying the reflection and absorption spectra. Six doses of gamma radiation of 145, 300, 450, 600, 750 and 900 Gy were examined. The absorption peak height in the spectral region of 560-580 nm is in a direct relationship with the gamma radiation doses up to about 800 Gy, in which saturation starts to occur. The intensities of the color centers in mixed crystals are different by their combination ratios of the components contents. According to the reflection and transmission data, the absorption spectra can be calculated and a calibration curve sketched.

In this paper, an eddy-current formulation is used to determine the transmission-line parameters of a machine winding. It is shown that this formulation covers a broader frequency range than the commonly used low-frequency magnetostatic and high-frequency magnetodynamic approximations. The eddy-current formulation, however, suffers from large computation times and may lead to severe inaccuracies if the finite-element mesh does not resolve the skin depth, a modelling concern that does not exist for the traditional formulations. The three finite-element models are compared according to the accuracy of the resulting transmission-line model applied to the winding of a permanent-magnet synchronous machine.


An in situ measurement system for oil palm fruit's permittivity and moisture content determination is presented. The instrumentation is includes a six-port reflectometer and an open ended coaxial probe which operates at 2 GHz. The developed system was tested and compared with the data obtained using commercial dielectric measurement probe and mixture model. This system is found to be practical for in situ measurement as well as fast and cost effective for oil palm fruit's properties and quality inspection.


In this article polarizability properties of spheres and ellipsoids are analyzed. For limiting shapes (disks and needles), the polarizability values can theoretically become extremely large. In the limiting process, however, the sequence is crucial in which the geometric parameters and the permittivity magnitude approach infinity. This article determines the levels of the achievable polarizability, which levels dictate the limits of the effective parameters of the composite to be made of such components. Furthermore, the plasmonic details in the negative permittivity domain are connected with the positive-permittivity behavior. Particular geometries carry over the plasmonic response to ENZ (epsilon-near-zero) materials, which brings forth interesting perspectives for material design with extreme parameters. These singularities are carefully analyzed in the present paper for non-magnetic and non-chiral particles.


In this paper we study helical inclusions of a certain shape (called the “optimal shape”), such that the electric, magnetic, and magneto-electric polarizabilities are equal, and discuss unusual reflection properties of artificial materials based on such inclusions. We study helical particles with optimized design parameters, which can make the realization of media with equal dielectric and magnetic susceptibilities possible. Not canonical helix, which consists of a split loop with two straight-wire sections, but the true helix, which is obtained by bending a wire with a constant pitch angle is investigated. The geometry of the helices makes it possible to create a composite material with equal permittivity and permeability.In such material optimal helices are located in pairs and each pair consists of the right-handed and left-handed helix.Thus compensation of chiral properties of a material as a whole is achieved.

Relativistic optics in moving media is an old topic in electromagnetic theory. The study of bianisotropic media – a very important class of metamaterials – stems from the research in that topic. However, a coordinate-free approach to moving media leads to rather cumbersome algebraic manipulations with tensors (or dyadics). In this article we present an alternative framework to deal with moving media: using spacetime algebra, the Clifford (geometric) algebra of Minkowski spacetime, we show that the inherent complexity of this subject can be substantially reduced through a transformation – the vacuum form reduction – that maps our problem into an equivalent spacetime with the same formal spacetime constitutive relation as real vacuum. This is made clear by showing that the two Maxwell equations (in spacetime) are reduced to a single Maxwell equation as in vacuum. We apply this technique to plane wave propagation in moving isotropic media which, from the laboratory perspective (that sees the movement), are actually nonreciprocal bianisotropic media. Our results are in full agreement with the conventional tensor and dyadic analyses.

New microwave nonreciprocal properties are investigated in “ferrite plate – grating of resonant elements” metasandwiches arranged along the axis of a rectangular waveguide in a transverse constant magnetic field. Giant nonreciprocity in the transmission is observed at the ferromagnetic resonance frequencies at certain values of the magnetic field under conditions of a mutual influence between the ferromagnetic and the grating resonances. In addition, nonreciprocal splitting of the resonance in grating elements is observed under small magnetic field, which is much less than the field necessary to the ferromagnetic resonance excitation. The nonreciprocal transmission does not take place in the case of free ferrite in the absence of a grating. Sign reversal of the nonreciprocity is observed, when ferrite transfers to the opposite side of a grating as well as under certain values of the constant magnetic field, when the sign reversal of difference between frequencies of the ferromagnetic resonance and the grating resonance takes place. Nonreciprocal effects are explained by the interaction between precessing spins in ferrite and a magnetic field of the surface wave, formed by a grating, and by coupling between the resonances of grating elements. It has been shown theoretically that microwaves in waveguide with bianisotropic layer, simulating a grating of resonant elements, are elliptically or circularly polarized with frequency and spatially – dependent rotating sense of the microwave magnetic field. The nonreciprocal effects have been observed for different grating elements: for both electric dipoles and chiral elements.

Full wave numerical study of electromagnetic wavereflection from and transmission through an array of thin, perfectconducting, planar strip complex-shaped elements placed on amagnetized ferrite substrate is carried out. Our results show,that the absorption level and the frequency band of the structure,when the ferromagnetic resonance and a metal element resonance areclose in frequency, are larger than the correspondingcharacteristics of the ferrite layer without metal elements. Asignificant enhancement of the Faraday rotation has frequencyshift with respect to the main resonance. Both right-handed andleft-handed circular polarized incident waves interact effectivelywith a metal array placed on ferrite substrate unlike the knownresonant interaction when only one kind (right- or left-handed) ofcircular polarized waves interacts with the ferrite slab withoutmetal elements.

For simple electric (magnetic) anisotropy a single function – one that maps a given direction of space to a specific value of permittivity (permeability) – is able to describe the electromagnetic behavior of the medium. Accordingly, the well-known classification of non-magnetic anisotropic crystals, as either uniaxial or biaxial, depends only on the characteristics of the permittivity function. However, when studying metamaterials, we frequently deal with general anisotropy characterized by two linear constitutive operators: the permittivity and permeability functions. Using the mathematical language of Clifford (geometric) algebra, we show – for general (reciprocal) anisotropy – that the direct interpretation of those two constitutive operators cannot provide an accurate description of the medium anymore. Namely, a new operator – one that depends on both those two constitutive operators – is needed, thereby leading to a new classification scheme. Therefore, although the uniaxial/biaxial characterization is still possible, the corresponding physical meaning is completely restated. Furthermore, a new concept – the pseudo-isotropic medium – emerges as a natural consequence of the new classification scheme.

In this paper the results of linear and nonlinear optical properties investigations of globular photonic crystals, filled by dielectrics or metals, are presented.