QERT - Quadrupole Electrical Resistivity Tomography

<p><span>The quadrupole technique for geoelectrics yields the apparent resistivity in a tensorial form in contrast to the scalar apparent resistivity obtained from classical geoelectrics. The quadrupole method in geoelectrics has been applied in the past only for long offsets between transmitter and receiver. We scaled down the method to profile-style and grid-style short offset applications. Analysis of the invariants of the apparent resistivity tensor and its representation as ellipse can be used to obtain an estimate of the dimensionality of the subsurface conductivity distribution. We present the basic theory of the quadrupole ERT technique along with numerical and field examples highlighting the advantages over classic geoelectrical survey methods.<br></span></p>

Time-Resolved Temperature Map Prediction of Concentration Photovoltaics Systems by Means of Coupled Ray Tracing Flux Analysis and Thermal Quadrupoles Modelling

A transient 3D thermal model based on the thermal quadrupole method, coupled to ray tracing analysis, is presented. This methodology can predict transient temperature maps under any time-fluctuating irradiance flux—either synthetic or experimental—providing a useful tool for the design and parametric optimization of concentration photovoltaics systems. Analytic simulations of a concentration photovoltaics system thermal response and assessment of in-plane thermal gradients induced by fast tracking point perturbations, like those induced by wind, are provided and discussed for the first time. Computation times for time-resolved temperature maps can be as short as 9 s for a full month of system operation, with stimuli inspired by real data. Such information could pave the way for more accurate studies of cell reliability under any set of worldwide irradiance conditions.