A fully polarimetric borehole radar system with four combinations of dipole and cylindrical slot antennas, as shown in Fig. 1, was developed to acquire fully polarimetric data sets in drilled boreholes [1]. The system in conjunction with a methodology of radar polarimetry analysis, proposed in previous (a) Measurement configuration (b) Antenna arrangements for polarimetric data collection Fig. ...

Method: In this paper, the shallow formation around the borehole is divided into plastic zone and elastic zone considering it under nonuniform in-situ stress. The collapse pressure formula of shallow formation is derived by taking the shrinkage rate of the borehole as the instability criterion. The fracturing pressure calculation model of shallow sediment under non-uniform in-situ stress is der...

Original scientific paper Traditional dc electrical exploration method will face great challenge when detecting deep, complex geologic target. With the purpose, forward modelling and inverse modelling method of borehole resistivity has been developed. According to the characters of geology, the geological model has been set up. The numerical simulation shows that borehole resistivity method is ...

In this paper, we will introduce a cocentered orthogonal loop and dipole antenna (COLD) to a borehole radar system. With the cocentered orthogonal loop and dipole antenna, we could obtain additional information on polarization state of arrival waves in the borehole radar using * optical modulators. We set the proposed antenna in a borehole actually, and made electromagnetic waves with known pol...

The AARC African American HIV/AIDS Research Forum is the first step in developing a community participatory research agenda to address HIV/AIDS among African Americans in Alameda County. This compendium compiles research happening in Alameda County in order to strengthen networks and collaborations as well as identify the gaps and opportunities for researchers and community partners to more eff...

Groundwater sampling from open boreholes in fractured-rock aquifers is particularly challenging because of mixing and dilution of fluid within the borehole from multiple fractures. This note presents an alternative to traditional sampling in open boreholes with packer assemblies. The alternative system called ZONFLO (zonal flow) is based on hydraulic control of borehole flow conditions. Fluid f...

New-generation electromagnetic (EM) and sonic logging tools are capable of measuring multi-frequency multi-component data at multiple depths of investigation. This allows us to image the formation around the borehole by using an inversion method. A method is developed for directly obtaining porosity and fluid saturation distributions by simultaneously inverting borehole EM and sonic measurement...

Seismic interferometry has become a technology of growing interest for imaging from borehole seismic data. We demonstrate that interferometry of internal multiples can be used to image targets above a borehole receiver array. We use an interferometry technique that targets the reconstruction of specific primary reflections from multiply reflected waves. In this target-oriented interferometry ap...