Research Facilities

The Auburn University Soil Physics and Subsurface Flow and Transport Laboratories are extremely well equipped to determine pertinent transport parameters for almost any kind of porous medium flow system. The highlights are the two fully automated, 2-dimensional, dual-energy gamma radiation systems, which can be used to simultaneously determine (i) the bulk density of a porous medium and its volumetric liquid content, (ii) the volumetric liquid contents of 2 immiscible liquids in a rigid porous medium, or (iii) the volumetric liquid content and the concentration of a dissolved chemical, such as NaI (for miscible liquids) or solubilized nonaqueous phase liquids. The provision of 2-dimensional movement of the gamma radiation sources and the detector allow measurements to be taken at any location in a 2-dimensional flow system.

 

In addition to determining the liquid contents in a porous medium with one of the 2-dimensional gamma systems, measurements of the liquid pressures, during both saturated and unsaturated conditions and for both water and nonaqueous phase liquids, can be made with tensiometers connected to pressure transducers.

Equipment, such as pumps, flow columns, and fraction collectors, to determine breakthrough curves as needed for the determination of diffusion- dispersion coefficients is also available. Several large flow containers are available for intermediate scale laboratory experiments. The latest computer equipment, consisting of PCs, SUN workstations, and a super computer, is available in the laboratories for use by the students.

A Gas Chromatograph (GC) is available for chemical analysis of Non-Aqueous Phase Liquids or tracers:
 

 
 

The Soil Physics group is also interested in the determination of surface tension, a parameter of great importance for estimating capillary pressure versus saturation curves. We recently acquired a DeNouy tensiometer, which permits quick and accurate determination of surface tension at the interface between liquids and air.
 

 
 
To maintain the electrical and electronic equipment in the laboratories, our group has the support of an Electronics Shop (C. Meadows) and a Digital Repair Shop. 
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