Traditional methods for studying tree roots are destructive and labor intensive, but available nondestructive techniques are applicable only to small scale studies or are strongly limited by soil conditions and root size. Soil electrical resistivity measured by geoelectrical methods has the potential to detect belowground plant structures, but quantitative relationships of these measurements wi...

Measurements of the mechanical and electrical properties of Nafion and Nafion/titania composite membranes in constrained environments are reported. The elastic and plastic deformation of Nafion-based materials decreases with both the temperature and water content. Nafion/titania composites have slightly higher elastic moduli. The composite membranes exhibit less strain hardening than Nafion. Co...

There is low resistivity contrast between reservoir zone and host formation in geothermal fields, especially in areas where the technique of water injection is being carried out. Therefore, in low contrast area, permittivity can be one of the important reservoir indicators besides resistivity. In this study, one EM tomography method of reconstructing the resistivity and permittivity from electr...

the need for clean groundwater resources to have sustainable development in a country is undoubted. due to the importance and high quality of karstic waters in supplying water in iran especially in shahrood city, it is attempted in this research work to recognize and explore karstic waters in southwest of tepal area, shahrood. for this purpose, integration of the results obtained from the metho...

protection of water resources from contamination and detection of the contaminants and their treatments are among the essential issues in the management of water resources. in this work, the time-lapse electrical resistivity tomography (ert) surveys were conducted along 7 longitudinal lines in the downstream of the latian dam in jajrood (iran), in order to detect the contamination resulting fro...

It is known that the three important parameters: resistivity, capillary pressure, and relative permeability, are all a function of fluid saturation in a porous medium. This implies that there may be a correlation among the three parameters. There have been many papers on the approach to inferring relative permeability from capillary pressure data. However the literature on the interrelationship...

An integrated surface geophysical pilot study at the Texas A&M University Brazos River Hydrologic Field Research Site (BRHFRS), College Station, Texas, was done to determine the effectiveness of methods for defining the hydrostratigraphic framework and hydrogeologic properties for a ground-water availability model. Time-domain electromagnetic (TDEM) soundings and direct-current (2D–DC) resistiv...

Laboratory measurements of the resistivity of three sandstone samples collected during imbibition (increasing SXJ) and drainage (decreasing Sn,) show pronounced hysteresis in resistivity throughout much of the saturation range. The variation in resistivity can be related to changes in pore-scale fluid distribution caused by changes in saturation history. The form of the hysteresis is such that ...

Defined by international telecommunications union (ITU), the spectrum in the band between 30 and 300 Hz are named as super low frequency (SLF). In this band, the electromagnetic waves are rarely shielded by strata of lower resistivity and can spread strongly. Therefore, it can be used on the earth’s surface to detect goaves underground. The equipment, which use the natural SLF electromagnetic s...

a detailed standard magnetotelluric (mt) study was conducted to recognize brine bearing layers in depths of less than 2000 m in the northeast of iran close to the southeastern shore of the caspian sea. long and medium period natural-field mt methods have proved very useful for subsurface mapping purpose by determining the resistivity of the near surface structure. mt data were analyzed and mode...