The entity-relationship (ER) model has proved a successful conceptual capture and modelling tool for the relational data model. Much effort has recently been made to extend the relational data model to describe historical information, but as yet little corresponding development in ER modelling has been made. We describe in detail the various temporal behaviours that entities and relationships m...

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 ...

The optimal design of production in fractured geothermal reservoirs requires knowledge of the resource’s connectivity, therefore making fracture characterization highly important. This study aims to develop methodologies to use resistivity measurements to infer fracture properties in geothermal fields. The resistivity distribution in the field can be estimated by measuring potential differences...

Transportation is a large and growing part of the world’s energy consumption. This drives a need for reduced weight of rail vehicles, just as it does for road vehicles. In spite of weight reductions, the vehicle still has to provide the same level of acoustic comfort for the passengers. Porous materials, with more than 90% air, are often included in multi-layer vehicle panels, contributing to a...

Recent numerical simulations of magnetic reconnection in two dimensions have shown that, when the resistivity is strongly localized, the reconnection region develops a Petschek-like structure, with the width of the inner diffusion region being of the order of the resistivity localization scale. In this paper, we combine this fact with a realistic model for locally-enhanced anomalous resistivity...

The reconnection of magnetic field lines is one of the fundamental processes that lead to the eruptive release of stored magnetic energy in plasmas. A large number of observations and experiments, e.g., solar flares, geomagnetic substorms, the sawtooth instability in fusion experiments, and laboratory reconnection experiments, support this hypothesis. Magnetic reconnection is important for the ...

Experimental evidence has made it clear that the size of an object can have an effect on its properties. The electrical resistivity of a thin film will become larger as the thickness of that film decreases in size. Furthermore, the electrical resistivity will also increase as the temperature increases. To help understand these relationships, a model is presented, and equations are obtained to h...

introduction: occurrence of landslides depends on several factors such as the composition and structure of earth materials, rainfall level, temperature, groundwater regime and cover crops. landslides are a main natural hazard in iran, because of its special geological conditions and its mountainous active tectonic regime. linear civil structures, such as roads, highways and railways, face serio...

The generalized effective-medium theory of induced polarization (GEMTIP) is a newly developed relaxation model that incorporates the petro-physical and structural characteristics of polarizable rocks in the grain/porous scale to model their complex resistivity/conductivity spectra. The inversion of the GEMTIP relaxation model parameter from spectral-induced polarization data is a challenging is...