The U.S. Geological Survey, in cooperation with San Antonio Water System, conducted a geophysical and geological study of the Cibolo Canyon development area, northeast Bexar County, Texas, to characterize hydrostratigraphic features and to map surface and subsurface hydrogeologic features of the Edwards aquifer. Capacitively-coupled (CC) resistivity and frequency-domain electromagnetic (FDEM) p...

Abstract Estimation of water saturation, S w , in shaly sandstone is an intricate process. The surface conduction clay minerals adds up to the electrolyte pore spaces, thus generating high formation conductivity that overshadows hydrocarbon effect. In each resistivity-based saturation model, key parameter factor, F which typically derived from Archie’s Law. Referring a log–log plot between fact...

In this paper, we present resistivity-logging-measurement simulation with the use of two types of borehole logging devices: those which operate with zero frequency (direct current, DC) and those with higher frequencies (alternate current, AC). We perform simulations of 3D resistivity measurements in deviated wells, with a sharp angle between the borehole and formation layers. We introduce a hie...

The effects of contact architecture, graphene defect density and metal-semiconductor work function difference on the resistivity of metal-graphene contacts have been investigated. An architecture with metal on the bottom of graphene is found to yield resistivities that are lower, by a factor of four, and most consistent as compared to metal on top of graphene. Growth defects in graphene film we...

X-ray absorption fine structure ~XAFS! measurements as a function of temperature have been carried out at the Mn K edge for La0.7Ca0.3Mn12xTixO3 and La0.7Ca0.3Mn12yGayO3 (x and y50.01 to 0.10! and correlated with transport and magnetization measurements. Most samples exhibit colossal magnetoresistance ~CMR! at low temperature. The magnetization data show a concentration dependence: the ferromag...

Abstract In this article, an algorithm is proposed and used to study the influence of harmonics on behavior medium‐voltage underground cables in flat formation. The a thermal model based heat equilibrium circuit nodes cable system. impact temperature rise elements capacity evaluated article. Also, derating factors for different soil types presented. Finally, measurement temperatures cores carri...

The total electric resistance R is theoretically linearly increasing function of the conductive wire length L because the electric conductivity K or electric resistivity r is independent on L. It was found out that dependence of electric resistance R on L is highly nonlinear for yarns containing the conductive metal fibers. The main aim of this paper is creation of the simple mechanistic model ...

We present electrical conductivity measurements (at a fixed frequency of 1kHz) performed on three directions on limestone samples from the quarry of Meriel, during uniaxial tests of deformation up to failure. Samples were saturated from 100% to 80% by drainage. The samples showed brittle fracture with Young’s modulus in the range 10-13 MPa. Formation factor (sample resistivity divided by water ...

We developed a three-dimensional finite-difference codes which can simulate the fully triaxial induction tool in a stratified, cross-bedded anisotropic formation. The sensitivity of the fully triaxial induction measurements in cross-bedded anisotropic formation is studied for the first time. The results show that the tensor measurements are sensitive to the formation resistivity anisotropy, for...

Nickel silicide (NiSi) nanowires with different linewidth (from 1000 to 32 nm) are formed in pre-patterned SiO2 trenches on a silicon substrate. SiO2 trenches are milled by focused ion beam (FIB) etching, and an electrical endpoint detection technique is used to control the FIB milling depth to just reveal the silicon surface. The formation is based on Ni thin film deposition and the subsequent...