Metasurfaces are planar optical elements that hold promise for overcoming the limitations of refractive and conventional diffractive optics. Original dielectric metasurfaces are limited to transparency windows at infrared wavelengths because of significant optical absorption and loss at visible wavelengths. Thus, it is critical that new materials and nanofabrication techniques be developed to e...

the oil-paper insulation is a type of an inexpensive combination insulation system in oil-filled power transformers. in this study the dielectric and strength properties of canola oil and mineral oil impregnated hand-sheet papers were investigated. all hand sheets were made of unbleached bagasse soda pulp with two different freeness levels of 200 ± 25 ml, csf and 400± 25 ml,csf. after drying th...

This work reports the development of atmospheric pressure plasma reactor with dielectric barrier discharge DBD for material treatment. The DBD discharge has been generated in planar geometry reactor powered by ac voltage provided by conventional high voltage transformer. The dielectric barrier consisted of two glass slabs, which cover both reactor electrodes. The air discharge gap between the d...

Photonic crystals are artificial low-loss either two-dimensional (2D) or three-dimensional (3D) dielectric structures with a periodic modulation of the refractive index. Due to Bragg reflection, electromagnetic (optical) waves cannot propagate through such structures in certain directions, at certain frequencies. Hence, photonic crystals can exhibit bandgaps (even omnidirectional bandgaps in ce...

We show that the main guiding mechanisms in dielectric-core photonic crystal optical waveguides are total internal reflection and distributed Bragg reflection. We also show that by placing a slab of semiconductor material between two photonic band gap ~PBG! mirrors, we can obtain waveguide modes at frequencies out of the photonic bandgap. These modes are similar to the modes of a conventional d...

Dielectric-barrier-discharge (DBD) plasma actuators are all-electric devices with no moving parts. They are made of a simple construction, consisting only of a pair of electrodes sandwiching a dielectric sheet. When AC voltage is applied, air surrounding the upper electrode is ionized, which is attracted towards the charged dielectric surface to form a wall jet. Control of flow over land and ai...

We have modeled and simulate asymmetric microstrip folded dipole antenna on substrate materials and study the antenna performances. The conventional wire dipole antenna configurations are converted into corresponding microstrip version. The complementary nature of parallel coplanar strip line and waveguide models have been used to model the dipole antenna. The transmission line parameters namel...

Nosecone radomes of hypersonic flight vehicles show degradation of electromagnetic (EM) performance characteristics due to variations in the dielectric parameters (dielectric constant and electric loss tangent) of the radome wall resulting from heating due to extreme aerodynamic drag. It is indicated that the EM performance predictions based on conventional monolithic half-wave wall based on av...

In this chapter we discuss optical properties of dual-periodic photonic (super-)structures. Conventional photonic crystal structures exhibit a periodic modulation of the dielectric constant in one, two or three spatial dimensions (Joannopoulos, 2008). In a dual-periodic structure, the dielectric constant is varied on two distinct scales a1,2 along the same direction(s). An example of such a var...