estuaries are considered as highly dynamic ecosystem that include the mixing or transition zone between river freshwater and saline water from oceans and seas. estuaries are very important aquatic systems by preserving the coastal biota. flocculation of metals during mixing of freshwater with saline water can be considered as the most important estuarine processes. due to flocculation process, ...

light is never being distributed homogeneously and it forms a gradient over biomass. the unidirectional nature of light gives rise to a vertical gradient of light intensity as a function of depth. the maximum depth of the light zone suitable for phytoplankton photosynthesis is designated as the euphotic depth. this study was designed to test the hypothesis of mixing depth of phytoplankton and i...

We combine a discrete-element-method simulation with a stochastic process to model the movement of spherical particles in a turbulent channel flow. With this model we investigate the mixing properties of two species of particles flowing through the channel. We find a linear increase of the mixing zone with the length of the pipe. Flows at different Reynolds number are studied. Below a critical ...

oxygen minimum zone dynamic coastal and shelf fronts thermocline tidal mixing runoff high energy turbidity daily–seasonal fluctuations in temperature & salinity ± high productivity halocline shelf break

To investigate processes that might affect chlorofluorocarbon (CFC) mixing ratios at the water table, a time series was obtained of unsaturated zone soil gas CFCs to depths of ca. 4 m at a site near New York City (NYC). Observed CFC 11, 12, and 113 mixing ratios were lower in winter than expected from either a local, high-resolution time series or remote atmospheric mixing ratios. A diffusion m...

Context. Protostellar accretion discs have cool, dense midplanes where externally originating ionisation sources such as X–rays or cosmic rays are unable to penetrate. This suggests that for a wide range of radii, MHD turbulence can only be sustained in the surface layers where the ionisation fraction is sufficiently high. A dead zone is expected to exist near the midplane, such that active acc...

The effect of short pulsing mixing interruptions on the Aspergillus niger R3 morphology and fermentation performance was studied in 5 l agitated fermenters with double Rushton turbine impellers. A stable increase in the mycelia concentration and higher biomass concentrations at the end of the process were achieved in two continuous mixing fermentations, while in two fermentations with mixing in...

1. Riparian zones function as important ecotones that reduce nitrate concentration in groundwater and inputs into streams. In the boreal forest of interior Alaska, permafrost confines subsurface flow through the riparian zone to shallow organic horizons, where plant uptake of nitrate and denitrification are typically high. 2. In this study, riparian zone nitrogen retention was examined in a hig...

Abstract We construct mixing solutions to the incompressible porous media equation starting from Muskat type data in partially unstable regime. In particular, we consider bubble and turned interfaces with Sobolev regularity. As a by-product, prove continuation of evolution IPM after Rayleigh–Taylor smoothness breakdown exhibited (Castro et al. Arch Ration Mech Anal 208(3):805–909, 2013, Castro ...