resistivity

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re·sis·tiv·i·ty

(rē'zis-tiv'i-tē),
A measure of a material's resistance to the passage of electrical current; the reciprocal of conductivity.
[L. re-sito, to withstand]
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The first zone shows relatively higher resistivity values that correlate with Jurassic strata outcrop and the second zone is characterized by low resistivity values whereas the third zone shows moderate resistivities that correlate with Plio-Quaternary alluvium.
Caption: Figure 10: Apparent resistivities along x- and y-direction for pole- pole array with changing dipping angles.
To construct the resistivity cross sections, the inverted electrical resistivities were sampled with depths.
To investigate the downward movement of irrigation water and to allow a temperature correction of the measured resistivities, soil temperature was measured every 15 min at 150, 300, 450, 850, and 1200 mm depth using a probe comprising five individual HOBO Water Temp Pro v2 sensors (Onset Computer Corporation, Bourne, MA).
This is followed by layers having resistivities of 39.7 ohm-m and 48.3 ohm-m and a thickness 0.93 m and 11.4 m, respectively.
With these long, floppy strings dispersed in a polymer, much lower loadings are needed to provide resistivities low enough to be useful.
[[rho].sub.A] = [[pi]/ln2] * [[f.sub.A]t] * [([V.sub.1] -[V.sub.2] + [V.sub.3] -[V.sub.4]) /(4I)] [[rho].sub.B] = [[pi]/ln2] * [[f.sub.B]t] * [([V.sub.5] - [V.sub.6] + [V.sub.7] - [V.sub.8]) / (4I)] where: [[rho].sub.A] and [[rho].sub.B] are volume resistivities (ohm-cm); t is the sample thickness (cm); [V.sub.1] through [V.sub.8] represent the measured voltages; I is the current through the sample (amperes); [f.sub.A] and [f.sub.B] are geometrical factors based on sample symmetry and related to the two resistance ratios [Q.sub.A] and [Q.sub.B] as shown in the following equations ([f.sub.A] = [f.sub.B] = 1 for perfect symmetry).
The ratio of different layers to their respective resistivities is known as longitudinal conductance.
It was reported that, at the same w/c ratio, the changes of the specimens' resistivities with different sizes ([phi]100 mm x 200 mm and [phi]150 mm x 300 mm) were close to those changes of the compressive strengths.
Let the medium comprise two layers with electric conductivities [[sigma].sub.1] and [[sigma].sub.2] (corresponding to specific resistivities [[rho].sub.1] and [[rho].sub.2], resp.).
Coatings for EMI shielding have surface resistivities less than 10s Q/sq [3], Conductive coatings are usually made by incorporating conductive fdlers in organic polymer film forming materials.
To interpret the sounding data, some decisions about the number of layers and layer resistivities are also taken on the basis of [C.sub.A] pattern revealed for each sounding.