A number of applications, for instance ultrasonic imaging and nondestructive testing, involve the transmission of acoustic energy across fluid–solid interfaces into dissipative solids. However, such transmission is generally hindered by the large impedance mismatch at the interface. In order to address this problem, inhomogeneous plane waves were investigated in this work for the purpose of imp...

In this paper, the reflection of ultrasonic guided waves from simple dent in pipes has been investigated using finite element method and the relationship between reflection coefficient of these waves and deformation rate has been determined. Also, the effect of the parameters of wave generation source on the generated wave field has been investigated using normal modes expansion method. At firs...

Modern transmission electron microscopes (TEM) allow utilizing the spherical aberration coefficient as an additional free parameter for optimizing resolution and contrast. By tuning the spherical aberration coefficient of the objective lens, isolated nitrogen atom columns as well as the Si–N dumbbells within the six-membered ring were imaged in b-Si3N4 along [0 0 01] and [0 0 0 1̄] projections w...

The properties of Mo/B4C multilayer X-ray mirrors with periods 3.74 – 3.84 nm are studied in this work. dependences the transmission band, reflection coefficient and magnitude internal stresses on ratio material thicknesses period were investigated. results a study effect thermal annealing structural parameters reflective characteristics also presented paper.

In this paper, the propagation of electromagnetic waves through an infinite slab of uni- or bi- axial chiral medium is analytically formulated for an arbitrary incidence using 4×4 matrix method. In this powerful method, a state vector differential equation is extracted whose solution is given in terms of a transition matrix relating the tangential components of electric and magnetic fields at t...

An algorithm to estimate reflection coefficient properties of materials based on code multipath errors is developed and tested in two urban environments. The algorithm extends an existing model that integrates 3D structure models, electromagnetic ray-tracing algorithms, antenna pattern measurements, and receiver tracking loop models to simulate code multipath errors. Instead of using the Fresne...

Parity-time (PT) symmetry is of great interest. The reciprocal and unidirectional features are intriguing besides the (PT) symmetry phase transition. Recently, the reciprocal transmission, unidirectional reflectionless and invisibility are intensively studied. Here, we show the reciprocal reflection/transmission in (PT)-symmetric system is closely related to the type of (PT) symmetry, that is, ...