Seismoelectric and seismomagnetic fields generated by acoustic waves in fluid-saturated fractured borehole models are experimentally investigated with an electrode and a Halleffect sensor. In a borehole with a horizontal fracture, the Stoneley and flexural waves induce seismoelectric and seismomagnetic fields on the borehole wall and an electromagnetic wave propagating with light speed at the h...

The seismoelectric logging method is based on measuring the electric field generated by seismic waves in a fluid-filled borehole. Two kinds of electromagnetic (EM) fields can be generated within the formation and at the interface of formations. One is a stationary or local EM wave and the other is a radiating EM wave. In this paper, we make various fractured borehole models with artificial mate...

Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This could result in a biased estimation of formation properties but could provide a means to estimate in situ stress from sonic logging data. In order to properly account for the formation property alteration, we propose an iterative numerical approach to c...

Borehole thermal energy stores used for seasonal heat storage in solar assisted district heating systems are very sensitive to groundwater flow. A heat and mass transport model has been developed by the authors in order to simulate the influence of moving groundwater on borehole thermal energy stores. This was done by combining an advanced numerical strategy, where the borehole heat exchangers ...

Fugro-McClelland Marine Geosciences Inc.’s piezoprobe, a penetrationbased tool used to determine pore pressure and hydrologic properties within a borehole, was deployed for the first time in the Ocean Drilling Program (ODP) on ODP Leg 204 in July 2002. Analysis of the piezoprobe data suggests that in situ pore pressure is 9.5 MPa, which is approximately the hydrostatic pressure (9.53 MPa). The ...

[1] We report on frictional properties of rocks within the 3-D crustal volume surrounding the San Andreas Fault Observatory at Depth (SAFOD). Samples include lithologies adjacent to the San Andreas Fault (SAF) in the subsurface, SAFOD borehole rocks, and synthetic fault gouge composed of talc, serpentinite, and quartz. Granodiorite, arkosic sandstone, and siltstone samples from the SAFOD boreho...

Many aspects of Earth's early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation, remain poorly understood--in part due to complications from postdepositional diagenetic and metamorphic processes. Using a combination of scanning high-resolution magnetic superconducting quantum interference device (SQUID) microscopy and secondary ion mass spe...

The insecticide susceptibility status of one of the Background: Anopheles funestus, main malaria vectors in the Afrotropical regions, remains under-studied due to the difficulty of working with this mosquito species. Collecting their larvae in natural breeding sites, rearing and maintaining them in normal laboratory conditions have been a difficult task. Forced-egg laying technique has been a v...

Background:  The insecticide susceptibility status of Anopheles funestus, one of the main malaria vectors in the Afrotropical regions, remains under-studied due to the difficulty of working with this mosquito species. Collecting their larvae in natural breeding sites, rearing and maintaining them in normal laboratory conditions have been a difficult task. Forced-egg laying technique has been a ...

the massive sulphide deposit at kantienpan cu-zn mine is hosted by volcano sedimentary succession known as the areachap group, in the eastern part of namaqua metamorphic province, south africa. the deposits were affected by a complex deformation and metamorphic history and represent examples of upper amphibolite to granulite grade metamorphosed volcanic-hosted massive sulphide (vhms) depo...