Helicopter-borne frequency-domain electromagnetic (HEM) surveys are used extensively for mineral and groundwater exploration and a number of environmental investigations. To have a meaningful interpretation of the measured multi- frequency HEM data, in addition to the resistivity maps which are provided in each frequency or for some particular depth levels, it is a necessity ...

in this paper, we studied effect of different parameters including density, viscosity, interfacial tension and solute transfer concentration on phase inversion hold-up. the results showed that change in phase density ratio had no effect on phase inversion hold-up. it also disclosed that the phase viscosity ratio was the most effective parameter affecting phase inversion hold-up and each phase h...

helicopter-borne frequency-domain electromagnetic (hem) surveys are used extensively for mineral and groundwater exploration and a number of environmental investigations. to have a meaningful interpretation of the measured multi- frequency hem data, in addition to the resistivity maps which are provided in each frequency or for some particular depth levels, it is a necessity to have a suit...

Two robust nonlinear controllers along with a nonlinear observer have been developed in this study to control a 1D nonlinear flexible spacecraft. The first controller is based on dynamic inversion, while the second one is composed of dynamic inversion and µ-synthesis controllers. The extension of dynamic inversion approach to flexible spacecraft is impeded by the non-minimum phase characteristi...

reflection and refraction of em signals at both horizontal and vertical interfaces separate media of different electrical parameters, geoelectromagnetic methods have been developed and employed to recognize the geological features and particularly fault zones in many regions. to achieve higher lateral resolution and also greater depth penetration, the mt method is one of the most effective elec...

Quasi-one-dimensional (1D) nanostructures, such as nanowires, nanobelts and nanorods, are the forefront materials for nanotechnology. To date, such nanostructures have been synthesized for a wide range of semiconductors and oxides, and they are potential building blocks for fabricating numerous nano-scale devices. 1D ZnO nanostructures, due to its unique semiconducting, piezoelectric, and bio-s...

Airborne electromagnetic (AEM) surveys carried out around the globe produce thousands of km of data every year. Because of the enormous computational costs involved in a full 3D inversion, these data are usually inverted using a 1D forward model. The 1D model assumption is legitimate in quasi layered sedimentary areas. In some cases the output models are simply stitched together (Auken et al., ...

We show that it is practical to invert entire airborne electromagnetic (AEM) surveys to 3D conductivity models with hundreds of thousands of cells within a day on a workstation. We have exploited the fact that the area of the footprint of an AEM system is significantly smaller than the area of an AEM survey to develop a robust 3D inversion method which uses a moving footprint. Our implementatio...