We present a robust and accuracy enhanced method for analyzing the propagation behavior of EM waves in z-periodic structures in (r, ö, z)-cylindrical co-ordinates. A cylindrical disk, characterized by the radius a and the periodicity length Lz, defines the fundamental cell in our problem. The permittivity of the dielectric inside this cell is characterized by an arbitrary, single-valued functio...

In this paper, we introduce the concept of generalized quasi-contractions in the setting of cone $b$-metric spaces over Banach algebras. By omitting the  assumption of normality we establish common fixed point theorems for the generalized quasi-contractions  with the spectral radius $r(lambda)$ of the quasi-contractive constant vector $lambda$ satisfying $r(lambda)in [0,frac{1}{s})$  in the set...

we consider   bivariate  mean-value interpolationproblem, where the integrals over circles are interpolation data. in this case the problem  is described  over   circles of the same radius and with  centers are on astraight line and it is shown that in this case the interpolation is not correct.

in this paper, the deformation of a thick-walled circular cylindrical shell of incompressible isotropic elastic material is considered. the shell, which is made of three-term strain energy function is subjected to the combined external and axial loading pressure. in order to obtain the relevant eigenvalues, which is the main objective of the work, the incremental equilibrium equations are so...

A‎s we know, developing mathematical models and numerical procedures that would appropriately treat and solve systems of linear equations where some of the system's parameters are proposed as fuzzy numbers is very important in fuzzy set theory. For this reason, many researchers have used various numerical methods to solve fuzzy linear systems. In this paper, we define the concepts of midpoint a...

We consider a static spherically symmetric charged anisotropic fluid source of finite physical radius (∼ 10−16 cm) by introducing a scalar variable Λ dependent on the radial coordinate r under general relativity. From the solution sets a possible role of the cosmological constant is investigated which indicates the dependency of energy density of electron on the variable Λ. PACS number: 04.20.-...

1. INTRODUCTION. Two incongruent solids with remarkable properties are shown in Figure 1. One is a slice of a solid hemispherical shell with inner radius r and outer radius R cut by a plane parallel to the equator and at distance h < r from the equator. The other is a cylindrical shell with the same radii and altitude h. The surface of each solid consists of four components: an upper circular r...

We consider a two-parameter family of cylindrical force-free equilibria, modeled to match numerical simulations of relativistic force-free jets. We study the linear stability of these equilibria, assuming a rigid impenetrable wall at the outer cylindrical radius R j. We find that equilibria in which the Lorentz factor γ(R) increases monotonically with increasing radius R are stable. On the othe...