The small-amplitude radial oscillations of a gas microbubble encapsulated by a viscoelastic solid shell and surrounded by a slightly compressible viscoelastic liquid are studied theoretically. The Kelvin–Voigt and 4-constant Oldroyd models are used to describe the viscoelastic properties of the shell and liquid, respectively. The equation for radial oscillation is derived using the method of ma...

An active antenna for transmitter application in S frequency band is designed and analyzed using harmonic balance technique which is based on the nonlinear model of active devices. In this active antenna, the amplifier is integrated with the radiator which is a rectangular patch antenna. This patch antenna is analyzed employing full-wave momentum method. By applying nonlinear model of transisto...

The frequency equation of carbon-nanotube-based cantilever sensor with an attached mass is derived analytically using nonlocal elasticity theory. According to the equation, the relationship between the frequency shift of the sensor and the attached mass can be obtained. When the nonlocal effect is not taken into account, the variation of frequency shift with the attached mass on the sensor is c...

Abstract: A new method to solve a Lyapunov equation for a discrete delay system is proposed. Using this method, a Lyapunov equation can be solved from a simple linear equation and N -th power of a constant matrix, where N is the state delay. Combining a Lyapunov equation and frequency domain stability, a new stability condition is proposed for a discrete state delay system whose state delay is ...

Hysteresis current control method is vastly used in PWM inverters because of simplicity in performance, fast control response and good ability in limiting peak current. However, switching frequency in hysteresis current control method with fixed bandwidth has large variation during a cycle and therefore causes non-optimal current ripple generation in output current. One of basic problems in imp...

The characteristics of dielectric backed planar conducting layers of arbitrarily shaped in a rectangular waveguide are calculated by means of coupled integral equation technique (CIET) which accurately takes higher order mode interactions. Equivalent structures for the accurate analysis whole structure are introduced in which magnetic surface currents are identified as the unknowns at the apert...

We investigate the convergence properties of a three-dimensional quantum lattice Boltzmann scheme for the Dirac equation. These schemes were constructed as discretizations of the Dirac equation based on operator splitting to separate the streaming along the three coordinate axes, but their output has previously only been compared against solutions of the Schrödinger equation. The Schrödinger eq...

The linearization approach is used in this contribution to acquire the answers variable frequency oscillator equation as well modified Ivey's equation. Differential forms (DF) and generalized Sundman transformation (GST) are two techniques that considered. It found cannot be linearized using differential forms, while for a can. However, GST, can linearized.

Thermal recovery involves well-known processes such as steam injection (cyclic steam stimulation, steam drive, and steam-assisted gravity drainage), in situ combustion, and a more recent technique that consists of heating the reservoir with electrical energy. When high frequency is used for heating, it is called electromagnetic (EM) heating. The applications of EM heating for heavy-oil reservoi...