Unveiling Informational Properties of the Chen-Ouillon-Sornette Seismo-Electrical Model

The seismo-electrical coupling is critical to understand the mechanism of geoelectrical precursors to earthquakes. A novel seismo-electrical model, called Chen–Ouillon–Sornette (COS) model, has been developed by combining the Burridge–Knopoff spring-block system with the mechanisms of stress-activated charge carriers (i.e., electrons and holes) and pressure-stimulated currents. Such a model, thus, can simulate fracture-induced electrical signals at a laboratory scale or earthquake-related geoelectrical signals at a geological scale. In this study, by using information measures of time series analysis, we attempt to understand the influence of diverse electrical conditions on the characteristics of the simulated electrical signals with the COS model. We employ the Fisher–Shannon method to investigate the temporal dynamics of the COS model. The result showed that the electrical parameters of the COS model, particularly for the capacitance and inductance, affect the levels of the order/disorder in the electrical time series. Compared to the field observations, we infer that the underground electrical condition has become larger capacitance or smaller inductance in seismogenic processes. Accordingly, this study may provide a better understanding of the mechanical–electrical coupling of the earth’s crust.

A piezoelectric contact problem with slip dependent friction and damage

The aim of this paper is to study a quasistatic contact problem between an electro-elastic viscoplastic body with damage and an electrically conductive foundation. The contact is modelled with an electrical condition, normal compliance and the associated version of Coulomb’s law of dry friction in which slip dependent friction is included. We derive a variational formulation for the model and, under a smallness assumption, we prove the existence and uniqueness of a weak solution.

An investigation over the effect of piezoelectricity and porosity distribution on natural frequencies of porous smart plates

The eigenvibration characteristics of a smart plate with piezoelectric layers and porous-cellular core are investigated in the present article. The core plate is assumed to be composed of materials that contain pores and the porosities may be distributed according to different mathematical rules. Variational principle is applied in order to derive the continuous system equations on the basis of Mindlin plate theory. A highly efficient analytical modeling for eigenfrequency analysis of the smart plate is presented under the assumption that both Skempton’s pore pressure coefficient and normal elongation through the thickness are negligible. Unlike numerical methods that require huge computational cost, this approach enables us to find the system’s response for rectangular plates with arbitrary dimensions. To examine the validity of the present framework, multiple comparison studies are made between the extracted results and those available in the literature. It is shown that the type of porosity distribution influences strongly on the way that frequency changes. Furthermore, it is found out that it is necessary to consider electrical effects for plates with open circuit condition unlike the other electrical condition.

MAP OF GEOELECTRIC SECTIONS OF THE SOUTH OF RUSSIA AND THE CAUCASUS

Детальное знание электрических свойств, строения и пространственного расположения различных комплексов горных пород необходимо при решении задач излучения и распространения электромагнитных волн в неоднородных средах с границами раздела сложной формы. Первичной основой образно-знаковых моделей электрического состояния верхней части земной коры могут служить разномасштабные карты электрических свойств (проводимости или геоэлектрических разрезов) стран и континентов, составленные в соответствии с определенными классификационными признаками. Неоднородная в электрическом отношении геологическая среда искажает амплитудно-фазовую структуру электромагнитного поля. Существенное повышение точности расчетов электромагнитного поля в широком диапазоне волн (от СДВ и до СВ-КВ) стало возможным с использованием прогнозных карт геоэлектрических разрезов (ГЭР), учитывающих слоистую структуру подстилающей среды. На них отражено площадное распределение различных типов ГЭР с указанием удельного электрического сопротивления, диэлектрической проницаемости и толщины каждого слоя ГЭР. Эти параметры позволяют рассчитать необходимые для прогнозирования условий распространения электромагнитных волн значения поверхностного импеданса, функции ослабления и уровня поля в широком диапазоне частот. Статья содержит результаты геоэлектрического картирования территории юга России и Кавказа. Изложена методология геоэлектрического картирования. Создана карта геоэлектрических разрезов (ГЭР) юга России и Кавказа масштаба 1:2 500 000. Эта карта позволяет в 1,5–3 раза увеличить точность расчетов электромагнитных полей по сравнению с существующей картой Моргана-Максвелла. Detailed knowledge of the electrical properties, structure and spatial arrangement of various rock complexes is necessary in solving problems of radiation and propagation of electromagnetic waves in inhomogeneous media with interfaces of complex shapes. The maps of electrical properties (conductivity or geoelectric sections) of continents and countries constructed on various scales according to certain criteria can serve as initial information for models of the electrical condition of the underlying medium. The electrical inhomogeneous geological medium distorts amplitude-phase structure of an electromagnetic field. Essential increase of accuracy of calculations of an electromagnetic field in a wide frequency band (from VLF and up to MF-SF) became possible with use predictive maps of geoelectric sections (GES), taking into account for the layered structure of the underlying medium. These maps reflect the areal distribution of various GES types, with the electrical resistivity, dielectric permittivity and thickness specified for each layer of GES. These parameters enable the calculation of values of surface impedance, attenuation function and field level in a wide range of frequencies. These values are necessary for prediction of electromagnetic waves propagation conditions. The article contains the results of geoelectric mapping of the territory of the south of Russia and the Caucasus. The methodology of geoelectric mapping is considered. A map of GES of the south of Russia and the Caucasus at a scale of 1:2 500 000 is created. This map makes it possible to increase the accuracy of the calculation of electromagnetic fields by 1,5 to 3 times in comparison with the existing Morgan-Maxwell map.

Electrical Interference Problemson Commercial Fishing Vessels – A Review

Canadian Coast Guard (CCG) provides Marine Communications centre (MCC) with financial assistance surveyed for Electromagnetic Compatibility and Electromagnetic Interference (EMC/EMI) correlated troubles on industrial based fishing vessels less than twenty metres. The electrical condition should be provided for the vessels and it is the goal of the survey. By performing "electrical noise" measurement method the necessary data was obtained. Several autopilot systems are susceptible to High Frequency Single Side Band (HF SSB) transmitters due to the absence of electrical noise suppression scheme. The main objective of the survey is to analyse the better electrical noise suppression method for fishing vessels.