We present an open source 3-D, MATLAB based, resistivity inversion package. The package uses a finite volume discretization to solve the forward partial differential equation. We include a highly efficient approach to reducing boundary effects and source electrode singularities. Solving of the forward problem is achieved by using a preconditioned bi-conjugate stabilized gradient method. For the...

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...

the purpose of this study is to correct the static shift of magnetotelluric (mt) data in one of the oil fields located in southwest of iran using time domain electromagnetic (tem or tdem) data. acquisition of the mt data has been made in the same area as the tem data was acquired at the frequency range of 0.0005-320 hertz. . a major problem in the mt method that occurs due to distribution of su...

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...

Spin-disorder resistivity of ferromagnetic metals from first principles: The disordered-local-moment approach" (2012). Kirill Belashchenko Publications. Paper 21. The paramagnetic spin-disorder resistivity (SDR) of transition-metal ferromagnets Fe, Co, Ni, ordered transition metal alloys Ni 3 Mn and Fe 3 Si as well as Ni 2 MnX (X = In,Sn,Sb) Heusler alloys is determined from first principles. S...

Electrical Impedance Tomography (EIT) has been the subject of intensive research since its development in the early 1980s by Barber and Brown at the Department of Medical Physics and Clinical Engineering, Hallamshire Hospital in Sheffield (UK). In particular, pulmonary measurement has been the focus of most EIT related research. One of the relatively recent advances in EIT is the development of...

Initialization of model parameters is crucial in the conventional 1D inversion of DC electrical data, since a poor guess may result in undesired parameter estimations. In the present work, we investigate the performance of neural networks in the direct inversion of DC sounding data, without the need of a priori information. We introduce a two-step network approach where the first network identi...

As a new cement-matrix composite material, fiber-reinforced concrete performs excellently in freeze–thaw resistance, tensile and seepage resistance. Since resistivity can be used to evaluate the performance of concrete, basalt–polypropylene (BPFRC) was investigated this study. Various parameters such as fiber type, content, water–binder ratio were also analyzed. The BPFRC tested by an improved ...

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...