recently a new structure called groove gap waveguide (GGW) is ‎introduced to implement low loss microwave component devices ‎especially for millimeter wave applications. This paper presents a ‎new type of H-plane horn antenna making use of this new technology ‎in which backward radiation is significantly suppressed by ‎introducing a high impedance surface at the antenna aperture. The ‎high impe...

A semi-empirical impedance model based on a single parameter (effective flow resistivity) for the characteristic impedance of fibrous materials has proved remarkably successful for predicting outdoor ground effects. This model allows for the effects associated with the porosity of the ground. Surface roughness with scales much smaller than the incident wavelengths influences reflection from har...

With the rapid progress of computers, wave-based room acoustics simulations like finite element method have come to be applicable onto many practical problems on acoustics. Generally, such methods can calculate sound fields quite accurately provided their boundary modelings are given appropriately. Although the absorption on the boundary can be modeled efficiently by using surface impedance, th...

The electric impedance of cultured myoblasts oriented on the scaffold with micro pattern has been measured between surface electrodes in vitro. Several parallel lines of micro rectangular ridges (0.001 mm height, 0.003 mm width, and 0.003 mm interval) have been made between a pair of the surface titanium electrodes at the surface of the scaffold of glass by the photolithography technique. C2C12...

This paper is concerned with investigation of vertical impedance function of a surface rigid circular foundation resting on a semi-infinite transversely isotropic alluvium. To this end, the equations of motion in cylindrical coordinate system, which because of axissymmetry are two coupled equations, are converted into one partial differential equation using a method of potential function. The g...

We deal with the acoustic inverse scattering problem for detecting an obstacle with mixed boundary conditions from the far field map. We show how the geometric properties and the material parameter distributed on the surface are involved in the obstacle reconstruction numerically. The main advance of this research on our recently work (SIAM J. Applied Math, 67(4), 2007) is the higher-order asym...

The concept of the surface impedance is applicable to the case, when obstacles on the surface of a vacuum chamber are small compared to characteristic dimensions of the problem. We apply this concept to the calculation of a synchronous mode that can propagate in a tube with slightly corrugated walls. We also show that such a mode can propagate in a pipe with a rough surface, or a perforated pip...

Different types of charge storage mechanisms at unmodified graphite vs. glassy carbon electrodes in acid sulphate supporting solution containing potassium hexacyanoferrate (II) redox active electrolyte, have been revealed by electrochemical impedance spectroscopy and supported by cyclic voltammetry experiments. Reversible charge transfer of Fe(CN)6 redox reaction detected by assessment of CVs o...