Earth resistivity estimates from frequency domain airborne electromagnetic data can vary over more than two orders of magnitude depending on the half-space estimation method used. Lookup tables are fast methods for estimating half-space resistivities, and can be based on in-phase and quadrature measurements for a specified frequency, or on quadrature and sensor height. Inverse methods are slowe...

Measurements of surface resistivity as a function of coverage for oxygen adsorbed on sulfur-predosed Cu(100) films reveal two types of interactions between sulfur and oxygen: S-O repulsion and short-range suppression of the surface resistivity change induced by oxygen adsorption. The repulsive interaction causes oxygen atoms to first occupy adsorption sites far from the sulfur atoms, beyond sec...

electrical resistivity survey is used to explore subsurface layers in hydrology, geology, mining, geotechnical and environmental investigations. the resistivity measurements are normally made by injecting current into the ground through two current electrodes, and measuring the resulting voltage difference at two potential electrodes. electrical resistivity is a function of injection current, m...

Fluctuations of resistivity have been monitored with an array measuring natural electric currents (telluric currents) in Parkfield. This array is designed to detect short-term relative changes of resistivity of 1% over days to weeks and long-term variations of 0.1% over months to years. Fractional daily variations of the telluric coefficients are computed and then compared to the earthquake rec...

This paper presents the fabrication, modeling, characterization and analysis of silicon-embedded, aircore, three-dimensional toroidal inductors for power converter applications. The inductors are fabricated within deep silicon recesses by means of a 3-D silicon shadow mask coupled with electroplating techniques. The losses in the inductor and the surrounding silicon are analytically modeled usi...

[1] Direct estimation of groundwater solute concentrations from geophysical tomograms has been only moderately successful because (1) reconstructed tomograms are often highly uncertain and subject to inversion artifacts, (2) the range of subsurface conditions represented in data sets is incomplete because of the paucity of colocated well or core data and aquifer heterogeneity, and (3) geophysic...

The rapid printing of 3D parts with desired electrical properties enables numerous applications. Fused deposition modeling (FDM) using conductive thermoplastic composites has been a valuable approach for such fabrication. The parts produced by FDM possess various controllable structural features, but the effects of the structural features on the electrical properties remain to be determined. Th...

Bioimpedance spectroscopy (BIS) is a technique of interest in the study of human pregnancy because it can assess extracellular (ECW), intracellular (ICW), and total body water (TBW) as ECW plus ICW. The technique requires appropriate resistivity coefficients and has not been sufficiently evaluated during the reproductive cycle. Therefore, in a methodological study, we estimated ECW, ICW, and TB...

There is growing interest in marine direct current (DC) resistivity methods for sub-seafloor exploration of a broad range of geophysical and geological targets. To address this, we have developed a new marine DC method with a vertical electrode configuration (VEC). Compared to conventional marine DC methods that use a horizontal electrode configuration, the shape and position of our VEC cable c...

Conceptual models of aquifer systems can be refined and complemented with geophysical data, and they can assist in understanding hydrogeological properties such as groundwater storage capacity. This research attempts to use geoelectrical methods, Electrical Resistivity Tomography and Induced Polarization parameters, for mapping the subsurface in alluvial fans and to demonstrate its applicabilit...