saltwater intrusion into freshwater in coastal areas has been a serious concern for many countries. providing fresh water in some regions is very crucial. in fact, the areas that  are prone to encountering salt water zones should be checked meticulously. the preferred method for such investigation is a precise 3-d model of distribution of fresh and salt water in order to reach such a model, rel...

We studied resistivity, magnetoresistivity, and Hall resistivity for a few percolating granular NiFe-SiO2 films upon thermal annealing. It was found that both the resistivity and the Hall resistivity decrease by two orders of magnitude upon annealing at 520 °C, accompanied by a crossover from an approximately 2lnT dependence of resistivity to a metallic behavior. On the other hand, transmission...

Discrepancies in body fluid estimates between segmental bioimpedance spectroscopy (SBIS) and gold-standard methods may be due to the use of a uniform value of tissue resistivity to compute extracellular fluid volume (ECV) and intracellular fluid volume (ICV). Discrepancies may also arise from the exclusion of fluid volumes of hands, feet, neck, and head from measurements due to electrode positi...

helicopter-borne frequency-domain electromagnetic (hem) surveys are used extensively for mineral and groundwater exploration and a number of environmental investigations. to have a meaningful interpretation of the measured multi- frequency hem data, in addition to the resistivity maps which are provided in each frequency or for some particular depth levels, it is a necessity to have a suit...

because of urgent needs of groundwater resources in the tochal region of north tehran, an integration of electric and electromagnetic methods was applied to investigate the location and the direction of water bearing fractures. first, the vlf electromagnetic profiling was performed on suitable places and two locations were detected for supplementary resistivity surveys. then, a number of vertic...

In electrical impedance tomography (EIT) images of the object are formed based on passive electrical properties of the interior structures. In EIT an array of electrodes is attached around the object and small alternating currents are injected via these electrodes and the resulting voltages are measured. Using di erent current injections and voltage measurements, an approximation for the spatia...

where d = thickness of the film, ,o = resistivity of the film, = resistivity of the bulk material having the same structure and approximately the same number of defects as the films, l0 = mean free path of the charge carriers. The values of l0 calculated by the two methods were found to agree satisfactorily. Figs. 7 and 8 show the variation of the Hall mobility (/̂ H) with film thickness and sub...

Electrical resistivity describes how much a certain material resists electrical flow. Every material has an associated resistivity, ρ, which is constant. Conductors, such as copper have a low resistivity, while insulators, such as glass, have a high resistivity. Resistivity is an important property of any electrical object because it directly relates to the resistance, which relates to Ohm’s la...