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In this work the scattering from a dielectric-coated orthorhombic dielectric–magnetic sphere is investigated. The fields inside the core are expanded in terms of recently derived closed-form vector spherical wavefunctions which incorporate anisotropy enabling solution of electromagnetic propagation in orthorhombic dielectric–magnetic material. The problem is solved by means of determination of transition matrix for coated composite scatterer. Numerical results for dielectric-coated biaxial as well as uniaxial orthorhombic dielectric–magnetic sphere are presented. The effect of coating of dielectric of various values on scattering cross-section efficiencies is discussed. It is shown that certain choices of dielectric properties increase the scattering cross-sections and the resonance of the curves are somewhat shifted at larger scattering angles.

Interaction of light with a certain kind of core-shell nanoparticle, with the shell being a hyperbolic metamaterial (HMM) made of alternating layers of silicon dioxide and indium-tin-oxide (ITO), was analytically investigated. The nanoparticle size was considered to be very small as compared to the operating wavelength, which allows the use of quasi-static approximation for treatment. Within the context, the effects of parametric features, such as the fill-factor (of ITO) and core-shell radii, on the constitutive properties, polarizability, and the scattering and absorption cross-sections were touched upon in detail. The results revealed the dielectric and HMM kinds of constitutive features of the shell, which could be altered depending on the ITO fill-factor and/or the operating wavelength. The obtained analytical results were verified considering simulations in respect of the illustrative case of scattering cross-section; the results were found to be in close agreement.

Characteristics of Radar Cross Sections (RCS) in the presence of ferrite coating layer on perfect electromagnetic conductor sphere have been studied theoretically and analytically. Spherical wave vector functions were used to expand the incident, scattered and transmitted electromagnetic field components. Co and Cross polarized scattered field components have been evaluated by applying PEMC boundary conditions at both interfaces, i.e., free space- ferrite layer and at ferrite layer-PEMC sphere core. By using obtained values of the Co and Cross polarized scattering coefficients, the forward and backscattered Radar Cross Section were calculated and compared with already published literature. The effects of applied dc bias magnetic field, saturation magnetization, incident frequency, sphere radius and relative permittivity on forward and backscattered radar cross section were analyzed in graphical form.

Two dimensional Green's function for grounded dielectric half space geometry in non-integer dimensional space has been derived. It has been assumed that both half spaces are of non-integer dimension. Radiated fields are written in terms of unknown plane wave spectrum. Unknown spectrum functions are determined using the boundary conditions. Special cases have also been addressed considering one or both the spaces are of integer dimensional space. The solution for both the spaces are of integer dimension is used to make a comparison with previously reported results. Results are reported for different values of physical and geometrical parameters.

The article presents analysis of scattering from a topological insulator sphere placed in an unbounded homogeneous, isotropic and lossless chiral metamaterial under the quasi-static perspective. Due to coupling of electric and magnetic fields in the constitutive relations for mediums describing regions inside and outside the sphere, cross component in fields appears for both regions of the geometry. Study of behavior of polarizabilities against different parameters of the geometry is presented. Special cases of the host medium are also treated. Results are compared with published results and found in good agreement.

Terahertz (THz) wave interaction from graphene coated metamaterial cylinder has been investigated analytically and numerically. The analytical formulation of electromagnetic fields is being modeled in the frame work of Mie theory while the modeling of the graphene is done by random phase approximation method. The causality principle based Kramer-Kroing relations are used to simulate the DNG metamaterial, while the DPS metamaterial is modeled by the Drude relations of SiO2. The analytical formulation is developed for both parallel and perpendicular polarized waves. The impedance boundary conditions (IBC) approach is used to model the infinitely thin graphene coating on metamaterial cylinder. Further the IBC at the interface of graphene layer and metamaterial cylinder are applied to compute the unknown scattering coefficients. The efficiency factors i.e., scattering efficiency (Qsca), extinction efficiency (Qexc) & absorption efficiency (Qabs) and bistatic radar cross section (RCS) have been computed analytically as well as numerically for both micro and nano cores. The influence of graphene parameters i.e., chemical potential (μc) & scattering rate (τ1) and size of metamaterial cylinder (R) on the scattering efficiency (Qsca) and extinction efficiency (Qexc) has been analyzed for DPS and DNG cores. It is observed that the in the nano regime, for perpendicularly polarized wave, graphene coated metamaterial cylinder supports the localized surface plasmon resonance (LSPR) modes and LSPR is found sensitive to the change in the graphene parameters and core size. However, it is reported that the parallel polarized wave has same response towards the DPS and DNG cores in the nano regime. It is concluded that under suitable parameters the graphene coating may provide extraordinary degree of freedom to actively control the THz interactions i.e., scattering efficiency, extinction efficiency and bistatic RCS. The present work may have potential applications in designing and manufacturing of Electromagnetic invisibility, cloaking and target protection devices for THz region. Keywords: Scattering, Absorption, Metamaterials, Graphene, Cylinder, Eco width, Radar Cross Section (RCS), Efficiency Factors, Surface Plasmon Resonance

The gain properties of an axially slotted cylinder clad with an inhomogeneous dielectric placed in non-magnetic lossless/lossy plasma material have been investigated. The effects of variation of different parameters like coating thickness, inhomogeneity parameter, and lossless/lossy plasma background on gain characteristics of an axial slot have been discussed. It is observed that gain becomes more directive by increasing coating thickness of inhomogeneous coating layer in lossless plasma material and maximum gain is observed in forward direction. And same has not been observed in the lossy material. In lossy material, a mixed behavior of gain pattern in the front and rear side of the slot has been observed. The effects of inhomogeneity parameters on gain characteristics of an axial slot have also been discussed. By increasing inhomogeneity, gain characteristics in the forward direction of the slot have been observed in the lossless plasma material. In the lossy plasma material, by varying inhomog...

Electromagnetic wave scattering from cylinders of different materials immersed in complex conjugate medium (CCM) is studied. CCM is a non-dissipative medium through which electromagnetic wave can travel without attenuation. Lengths of cylinders are infinite and CCM is also taken as infinite. Chiral, perfect electromagnetic conductor (PEMC), nihility and dielectric cylinders have been considered for the analysis. TM polarization is considered for the normally incident plane wave on the cylinder. Scattered fields are then formulated in terms of unknown coefficients. It is a boundary value problem. Boundary conditions are used according to the material of the cylinder to find the unknown coefficients. Once the scattered fields are known, far fields approximations are used to find the scattering widths for the co and cross polarized components. Numerical results are shown to give a comparison between the cylinders of different materials immersed in the same material. Comparison of work found in good agreement with already published work.

An analytical solution is derived for the scattering of an electromagnetic plane wave from parallel multiple perfect electric conducting (PEC) circular cylinders coated with chiral material. The PEC cylinders and the coating layer are infinite along the axes of cylinders. Parallel polarization has been considered for the analysis. Comparison is carried out between the results for PEC cylinders coated with chiral material and coated with ordinary dielectric material. The numerical results are compared with the published literature and are in good agreement. It has been observed that forward and backward scattered fields of parallel chiral coated PEC cylinders depend on the thickness of chiral coating material, and can be controlled with suitable selection of parameters.

The Laplace's equation in a fractional dimensional space describes the electrostatic potential inside fractal media in the framework of fractal continuum models. An exact solution of the Laplace's equation for cylindrical coordinate system in a space having fractional (non-integer) dimensions is derived and discussed. The discussion is divided into different cases. These cases are based on the values of parameters describing the order of fractional dimensional space and the parameter used to describe azimuthal and/or radial dependency of the potential. A coaxial cable with constant potential and filled with a fractional dimensional space is also solved as an example.

TiO2 in the form of macroscopic beads was prepared by resin templating. Anion-exchange macroporous resin beads were treated with a synthesis gel containing titanium isopropoxide, iso-propanol and diluted (0–5 wt.%) tetrapropylammonium hydroxide (TPAOH) aqueous solutions. The Ti-resin composite obtained was calcined at 600 °C to remove the resin. The presence of TPAOH in the precursor solution was essential for producing intact TiO2 beads. The use of 1–1.5 wt.% TPAOH resulted in anatase beads, whereas further increase in the TPAOH content promoted the anatase to rutile phase transformations. Decreasing the heating rate used during calcination also resulted in changes in the TiO2 composition from pure anatase (16 °C min−1 heating rate) to anatase with rutile impurities (0.5 °C min−1 heating rate). The photocatalytic activity of the TiO2 beads was evaluated for the degradation of acetone under ultraviolet irradiation. A high activity was displayed by the TiO2 samples composed of anatase with rutile impurities, whereas the activity was lower for pure anatase samples or samples containing mainly rutile. The TiO2 beads showed higher rates of charge carrier generation and slower charge trapping/recombination rates compared to a reference Cristal ACTiV™ PC500. In addition, the TiO2 beads could be used in at least five consecutive catalytic cycles without any in-between cycle treatment, without significant changes in their activity. The TiO2 beads prepared in this work are beneficial for photocatalytic applications in the gas-phase compared to powders due to easy handling, reduced pressure drop and attrition resistance.

Quasi-static analysis of scattering by an electrically small perfect electromagnetic conductor (PEMC) sphere embedded in chiral metamaterial is addressed. The PEMC is considered as a generalization of the perfect electric and perfect magnetic conductors. The problem is treated in terms of wave fields which are certain combinations of electric and magnetic fields. The effects on polarizabilities corresponding to scattered fields are analyzed with respect to different parameters. Free space as a special case for host medium is also taken into account.

Plants of Oxalis corymbosa displaying typical viral symptoms were observed during spring 2010 in plant nurseries in central India. The virus was mechanically transmissible to indicator plants and induced symptoms similar to those incited by Cucumber mosaic virus (CMV). Electron microscopic examinations of symptomatic leaf samples revealed the presence of isometric virus-like particles about 28–30 nm in diameter. Molecular detection methods allowed the identification of the pathogen as a CMV. The results were confirmed by reverse transcription polymerase chain reaction with specific CMV primers, and digestion with a restriction enzyme. The coat protein gene was 95 and 99% identical at the nucleotide and amino acid levels, respectively, to the published sequences of CMV, high amino acid sequence homology in multiple alignment analysis and closest phylogenetic relationship with Lucknow isolate (JX570732) of CMV. This represents the first record for CMV-infecting O. corymbosa in Aligarh India.

The electric and magnetic field expressions of guided waves in three-layer planar waveguide containing strong chiral material have been investigated theoretically. All three layers are parallel to the walls of the waveguide. Middle layer of the waveguide is filled with the air however the other two layers are filled with strong chiral material. The behavior of field intensity in different regions of the waveguide is discussed. It is shown that the location of maximum field intensity is shifted by changing the source frequency and modes of waveguide.

High-frequency fields refracted by a geometry that contains an inhomogeneous slab placed at a certain distance from a plane uniaxial interface are derived by using Maslov's method. The geometrical optics approximation that is generally valid for high-frequency fields fails in the vicinity of a caustic. Maslov's method is a systematic procedure for predicting the field in the caustic region combining the simplicity of rays and the generality of the transform method. Numerical computations are carried out for the field pattern around the caustic or focal point by using Maslov's method. The results are found to be in good agreement with those obtained using Kirchhoff's approximation.