The implementation of VGR-stress imaging technique, as a free surface boundary condition, in a (2, 4) staggered grid P-SV wave finite difference (FD) algorithm with a variable size of a grid cell is presented in this paper. VGR is acronym for 'vertical grid-size reduction'. The qualitative and quantitative results confirmed that the effective thickness (ETH) of the first soil layer become less ...

This paper describes a σ -coordinate scalar transport model coupled with a Boussinesq-type hydrodynamic model. The Boussinesq model has the ability to calculate both three-dimensional velocity distributions and the water surface motion. To capture ‘dispersion’ processes in open channel flow, horizontal vorticity effects induced by a bottom shear stress are included in the Boussinesq model. Thus...

Oxygen minimum zones (OMZs) are natural physical features of the world's oceans. They create steep physiochemical gradients in the water column, which most notably include a dramatic draw down in oxygen concentrations over small vertical distances (<100 m). Microbial communities within OMZs play central roles in ocean and global biogeochemical cycles, yet we still lack a fundamental understandi...

We are interested in the modeling of wave-current interactions around surf zones at beaches. Any model that aims to predict the onset of wave breaking at the breaker line needs to capture both the nonlinearity of the wave and its dispersion. We have therefore formulated the Hamilto5 nian dynamics of a new water wave model, incorporating both the shallow water and pure potential flow water wave ...

In a sample of local active galactic nuclei studied at a spatial resolution on the order of ten parsecs we show that the interstellar medium traced by the molecular hydrogen ν=1-0 S(1) line at 2.1 μm forms a geometrically thick, clumpy disk. The kinematics of the molecular gas reveals general rotation, although an additional significant component of random bulk motion is required by the high lo...

An alternative being considered for the Next Linear Collider (NLC) is not to tunnel in a straight line but to bend the Main Linac into an arc so as to follow an equipotential. We begin here an examination of the effects that this would have on vertical dispersion, with its attendant consequences on synchrotron radiation and emittance growth by looking at two scenarios: a gentle continuous bendi...

We report on experimental demonstration of a digital coherent detection link fully based on vertical cavity surface emitting lasers (VCSELs) for the transmitter as well as for the local oscillator light source at the receiver side. We demonstrate operation at 5 Gbps at a 1550 nm wavelength with record receiver sensitivity of -36 dBm after transmission over 40 km standard single mode fiber. Digi...

A new perturbation analysis is presented which provides a first approximation to the wave-current interaction. The model is shown to provide a good description of laboratory data provided by Swan, Cummins & James (2000) and of results from a numerical formulation. These comparisons confirm that the near-surface vorticity leads to an important modification of the dispersion relation. The results...

We present here the experimental determination of the dispersion relation of surface waves of a ferro uid submitted to a steady vertical magnetic eld. The results are compared to a linear theory where all the magnetic characteristics of the uid have been taken into account. The knowledge of the dispersion equation is then used to analyse the capillary-wave resistance, that is the drag force ass...

In a sample of local active galactic nuclei (AGNs) studied at a spatial resolution on the order of 10 pc, we show that the interstellar medium traced by the molecular hydrogen ν=1-0 S(1) line at 2.1 μm forms a geometrically thick, clumpy disk. The kinematics of the molecular gas reveals general rotation, although an additional significant component of random bulk motion is required by the high ...