waveguides with low confinement loss, low chromatic dispersion, and low nonlinear effects are used in optical communication systems. optical fibers can also be employed in such systems. besides optical fibers, photonic crystal fibers are also highly suitable transmission media for optical communication systems. in this paper, we introduce two new designs of index-guiding photonic crystal fiber ...

The longitudinal dispersion coefficient is used to describe the change in characteristics of a solute cloud, as it travels along the longitudinal axis of a pipe. Taylor [1954] proposed a now classical expression to predict the longitudinal dispersion coefficient within turbulent pipe flow. However, experimental work has shown significant deviation from his prediction for Re < 20000. This paper ...

a r t i c l e i n f o The longitudinal dispersion coefficient (D) is an important parameter needed to describe the transport of solutes in rivers and streams. The dispersion coefficient is generally estimated from tracer studies but the method can be expensive and time consuming, especially for large rivers. A number of empirical relations are available to estimate the dispersion coefficient; h...

Let a(x), b(x), p(x) be formal power series in the indeterminate x over C (i.e., elements of the ring C [[x]] of such series) such that ord a(x) = 0, ord p(x) = 1 and p(x) is embeddable into an analytic iteration group (π(s, x))s∈C in C [[x]]. By a covariant embedding of the linear functional equation φ(p(x)) = a(x)φ(x) + b(x), (L) (for the unknown series φ(x) ∈ C [[x]]) with respect to (π(s, x...

We analyze the dispersive properties of inhomogeneous nanostructures (INSs) composed of alternating layers of different materials. Analysis of the interaction between the propagating pulse and the INS provides modified dispersion characteristics. An approximate theoretical model predicting the dispersion properties of the INS is developed and compared with more accurate numeric computation resu...

introduction the movement and fate of solutes in the subsurface in affected by a large number of physical, chemical processes requiring a broad array of mathematical and physical sciences to study and describe solute transport. the dispersion is an important parameter in the advection – dispersion equation, which is used in assessing, and solving the problems related to the contamination and th...

This paper uses an orthotropic shell model to investigate in detail the long axial wavelength circumferential vibration of microtubules (MTs). The deformation patterns in the vibrations were explored and their phonon dispersion relations were presented for MTs with increasing radius. It was shown that with the growth of the axial wavelength, the associated frequency of MTs would finally approac...