Tracer responses in gas-liquid, two-phase flow through a fractured layer are discussed. Experiments were carried out using a glass bead bed in a cylinder. In the results, over a wide range of flow conditions of particle size, fluids-flow velocity, and water saturation (Sw), one of three types of liquidand gas-flow pattern was obtained: a single-phase (water) flow with entrapped gases, a bubble ...

An approximate confidence interval is proposed for a robust measure of relative dispersion—the coefficient of quartile variation. The proposed method provides an alternative to interval estimates for other measures of relative dispersion. © 2005 Elsevier B.V. All rights reserved.

We study propagation of dispersion-managed solitons in optical fibers which are modeled by the nonlinear Schrödinger equation with a periodic dispersion coefficient. When the dispersion variations are weak compared to the average dispersion, we develop perturbation series expansions and construct asymptotic solutions at the first and second orders of approximation. Due to a parametric resonance...

Short-range correlated uniform noise in the dispersion coefficient, inherent in many types of optical fibers, broadens and eventually destroys all initially ultra-short pulses. However, under the constraint that the integral of the random component of the dispersion coefficient is set to zero (pinned), periodically or quasi-periodically along the fiber, the dynamics of the pulse propagation cha...

The dispersion equation governing the guided propagation of TE and TM fast wave modes of a circular cylindrical waveguide loaded by metal vanes positioned symmetrically around the wave-guide axis is derived from the exact solution of a homogeneous boundary value problem for Maxwell’s equations. The dispersion equation takes the form of the solvability condition for an infinite system of linear ...

Hydrocarbon contamination of unsaturated soils has been a serious environmental problem for decades. Two of the most common methods of remediating these sites are soil vapour extraction (SVE) and bioventing. Predictive models have been developed for the SVE and bioventing processes in order to estimate mass transfer coefficients for experimental systems and clean up times for field sites. These...