Multi-Parameters Study on Landfill Pole-Dipole Leak Detection
The theoretical model of pole- dipole landfill leak detection and the parameters that influence the location results are studied in this paper. Parametric curves for a single leak show that the greater the thickness of the media above the liner, and the greater the distance from dipole and HDPE, the lower of the detection sensitivity; in a certain range, expand the dipole spacing, leaks can be detected effectively. To identify and resolve multiple leaks, the potential measurements must be made close to the liner and the detector dipole spacing must smaller than the separation of the leak.
Leak current model in leakage detection of HDPE liner using high voltage DC method
A new leak current model of high voltage DC leak detection is developed. For single-liner landfill, the waste material layer, the geomembrane liner, and the soil under the liner are simulated by infinite horizontal layers. And the leak current is regarded as two parts, which one is negative current resource at the entrance, and the other one is positive current resource with the same size at the exit. To identify the validity of the model and locate the leaks in the geomembrane liner, pole-dipole experiments above the liner and fixed electrodes experiments under the liner were carried out at a medium scale geomembrane lined facility. The agreement is satisfactory between the experimental data and the calculated model value, which validates that it is helpful to predict leaks in geomembrane liner with the model.
Mississippian Barnett Shale: Lithofacies and depositional setting of a deep-water shale-gas succession in the Fort Worth Basin, Texas
The Mississippian Barnett Formation of the Fort Worth Basin is a classic shale-gas system in which the rock is the source, reservoir, and seal. Barnett strata were deposited in a deeper water foreland basin that had poor circulation with the open ocean. For most of the basin's history, bottom waters were euxinic, preserving organic matter and, thus, creating a rich source rock, along with abundant framboidal pyrite. The Barnett interval comprises a variety of facies but is dominated by fine-grained (clay- to silt-size) particles. Three general lithofacies are recognized on the basis of mineralogy, fabric, biota, and texture: (1) laminated siliceous mudstone; (2) laminated argillaceous lime mudstone (marl); and (3) skeletal, argillaceous lime packstone. Each facies contains abundant pyrite and phosphate (apatite), which are especially common at hardgrounds. Carbonate concretions, a product of early diagenesis, are also common. The entire Barnett biota is composed of debris transported to the basin from the shelf or upper oxygenated slope by hemipelagic mud plumes, dilute turbidites, and debris flows. Biogenic sediment was also sourced from the shallower, better oxygenated water column. Barnett deposition is estimated to have occurred over a 25-m.y. period, and despite the variations in sublithofacies, sedimentation style remained remarkably similar throughout this span of time.