Koyna region is well-known for its triggered seismic activities since the hazardous earthquake of M = 6.3 occurred around the Koyna reservoir on 10 December 1967. Understanding the shallow distribution of resistivity pattern in such a seismically critical area is vital for mapping faults, fractures and lineaments. However, deducing true resistivity distribution from the apparent resistivity dat...

Intracranial bleeding is one of the most severe medical emergencies in neurosurgery. Early detection or diagnosis would largely reduce the rate of disability and mortality, and improve the prognosis of the patients. Electrical Impedance Tomography (EIT) can non-invasively image the internal resistivity distribution within a human body using a ring of external electrodes, and is thus a promising...

Myocardial electrical impedance is influenced by the mechanical activity of the heart. Therefore, the ischemia-induced mechanical dysfunction may cause specific changes in the systolic-diastolic pattern of myocardial impedance, but this is not known. This study aimed to analyze the phasic changes of myocardial resistivity in normal and ischemic conditions. Myocardial resistivity was measured co...

The electrical resistivity of pure liquid selenium has been measured by many investigators [ 1 — 7 ] ; yet only a few of them describe the way in which their samples were prepared. Abdullaev et al. [3] and later Gobrecht et al. [4] and Koningsberger [5] have found that small amounts of oxygen have an enormous influence on the electrical resistivity of the liquid. Furthermore it was found [3, 5]...

Using the same colour scheme as the flow diagram above, Figure 2 shows how this conceptual framework applies for DC methods. The energy source is a pair of electrodes that inject a well-known current into the ground at known locations (Fig. 2a). The earth affects this energy because variations in the electrical conductivity of subsurface structures will bend the current flow lines (Fig. 2b). Th...

Normal silicon wafer substrate resistivity ranges for CMOS technologies have typically spanned from a low of about 5 mohm-cm on heavily doped epi substrates to a high of around 30 ohm-cm on polished wafers. Although heavily doped substrates have proven useful for protection against latch-up, digital CMOS device design and performance has not been strongly coupled directly to substrate resistivi...

S U M M A R Y We propose a new, simple and efficient method to image electrical resistivity between a set of wells. Our procedure consists of two steps: first, we map the interfaces between various subsurface formations using seismoelectric conversions; second, we derive the formation resistivity using image-guided cross-well electric tomography. In the first step, we focus seismic energy at a ...

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...

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...

This paper proposes a useful technique for generating an earth resistivity map. Earth resistance is one of essential factors in a broad range of power system analysis and design. Information of earth resistivity is helpful for practical power system engineers in order to establish power system grounding. In this paper, a LANSAT7 image of a tested area of 50 km was used by ENVI program in associ...