The mixing behavior of the gas-liquid phase in three loop bioreactors was investigated. A gas-induced External Airlift Loop Bioreactor (EALB), a forced-liquid Vertical Tubular Loop Bioreactor (VTLB) and a forced-liquid Horizontal Tubular Loop Bioreactor (HTLB) were used for mixing studies as well as biomass production from natural gas. The effect of design parameters, riser to downcomer cro...

—The toxicity of an acid mixing zone produced at the confluence of a stream that was contaminated by acid mine drainage (AMD) and a pH-neutral stream was investigated in toxicity tests with juvenile bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides. Fish mortalities in instream cages located in the mixing zone, below the mixing zone, and upstream in both tributaries were co...

Statistical properties of the temperature field in turbulent convection are studied experimentally. We show that the skewness of the plus and minus temperature increments can be used to quantitatively characterize the mixing zone in the convective flow and the result reveals how the mixing zone evolves with the Rayleigh number. We also present evidence for the saturation of the temperature stru...

We examine the generation of gravity waves by the surface convection zone of low-mass main sequence stars with solar metallicity. It is found that the total momentum luminosity in waves rises with stellar mass, up to the quasi-disappearance of the convection zone around 6500 K (corresponding to a mass of ∼1.4 M⊙ for solar metallicity) where the luminosity drastically drops. We calculate the net...

Previous research on self-similar mixing caused by Rayleigh-Taylor (RT) instability is summarized and a recent series of high resolution large eddy simulations is described. Mesh sizes of approximately 2000 ×1000 × 1000 are used to investigate the properties of high Reynolds number self-similar RT mixing at a range of density ratios from 1.5 : 1 to 20 : 1. In some cases, mixing evolves from 'sm...

We analyze the combined effects of aquifer heterogeneity and pumping operations on seawater intrusion (SWI) in coastal aquifers, a phenomenon which is threatening Mediterranean and worldwide regions. We conceptualize the aquifer as a three-dimensional randomly heterogeneous porous medium, where the spatial distribution of permeability is uncertain. The geological setting of our study is pattern...

Abstraet -A profile of aqueous S species concentrations and stable isotope compositions is presented for the mixing zone of Cousteau's Blue Hole, North Andros, Bahamas, together with similar, but less detailed results from two other blue holes. These data show that S o and S 2are produced by bacterially mediated sulphate reduction near the base of the mixing zone and that these species are reox...

In this paper, we explore properties of shock wave solutions of the Gray-Thornton model for particle size segregation in granular avalanches. The model equation is a nonlinear scalar conservation law expressing conservation of mass under shear for the concentration of small particles in a bidisperse mixture. Shock waves are weak solutions of the partial differential equation across which the co...