Stratification effects by fine suspended sediment at low, medium, and very high concentrations

Formulating Fine to Medium Sand Erosion for Suspended Sediment Transport Models

The capacity of an advection/diffusion model to predict sand transport under varying wave and current conditions is evaluated. The horizontal sand transport rate is computed by vertical integration of the suspended sediment flux. A correction procedure for the near-bed concentration is proposed so that model results are independent of the vertical resolution. The method can thus be implemented ...

Densimetric Monitoring of Suspended-sediment Concentrations, Northeastern Georgia

Differential pressure transducers can be used to monitor the suspended-sediment concentration in a water column. Suspended sediments with densities greater than water increase the fluid density, which is determined by measuring the fluid pressure change between two depths. Lewis and Rasmussen (1999) used a densimetric technique under controlled conditions to determine suspended-sediment concent...

Monitoring baseline suspended sediment in forested basins: the effects of sampling on suspended sediment rating curves

Rating curves are widely used for directly assessing changes in the suspended sediment delivery process and indirectly for estimating total yields. Four sampling methods were simulated over a 31-day record of suspended sediment from the North Fork of the Mad River near Korbel, California. The position and size of the four groups of plotted slope/intercept pairs indicated differences in bias and...

The Intrusion of Fine Suspended Sediment into a Sandy Sediment Bed a Literature Review

Selection of antibiotic resistance at very low antibiotic concentrations

Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic v...