The transport of colloid in unsaturated porous media affects the migration contaminants and thus is closely related to groundwater resources protection. To figure out combined effects grain size, concentration injection flow rate on montmorillonite characteristics quartz sand, a total 27 sets column experiments were conducted with three kinds sand (20, 40, 60 mesh), rates (1.98, 3.96, 5.94 cm 3...

The objective of this research was to evaluate the effect of low concentrations of a rhamnolipid biosurfactant on the in situ biodegradation of hydrocarbon entrapped in a porous matrix. Experiments were performed with sand-packed columns under saturated flow conditions with hexadecane as a model hydrocarbon. Application of biosurfactant concentrations greater than the CMC (the concentration at ...

Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a se...

The determination of soil-water characteristic curve (SWCC) is of major concern in unsaturated soil mechanics. For decades experimental and theoretical studies are performed to investigate the constitutive relationship between soil suction and volumetric water content. The major objective of our study is to generate an extensive experimental database for sand with a relevant suction range of ju...

Climatic changes and neotectonic movements in the north-western plains of India have led to the migration and abandonment of drainage systems to form a large number of palaeochannels. Palaeochannels present in the study area were extracted from final geomorphological map. These were delineated from satellite image by considering combination of various factors. These channels show a discontinuou...

Abstract A sets of sand column experiments were conducted to investigate the transport and deposition of colloids in water-saturated porous media, and the mechanism of the permeability reduced by transport and deposition of colloids are discussed. The research results show that the breakthrough curves of colloid transport in water-bearing media presented as three stages: “not-yet-breakthrough”,...

A new sandpile model is studied in which bonds of the system are inhibited for activity after a certain number of transmission of grains. This condition impels an unstable sand column to distribute grains only to those neighbours which have toppled less than m times. In this non-Abelian model grains effectively move faster than the ordinary diffusion (super-diffusion). A novel system size depen...

Surface water–groundwater exchange affects the material and energy transfer of rivers adjacent riparian zones. As an intuitive carrier energy, temperature can effectively reflect spatial temporal variation surface process. In this paper, influence water head sand sample uniformity on its field seepage is studied through a one-dimensional column laboratory test. To verify accuracy vertical heat ...