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With a view to evaluating the possibility of non invasive sensing of soil compaction by means of the application of a variable electromagnetic field, a theoretical - experimental study of the interaction < electromagnetic field-soil > is made, by using finite element simulation, as well as experimentation in a soil deposit. In a previous paper the influence on the soil response to the action of a variable electromagnetic field is determined in function of the excitement frequency of a field-generator coil and of the distance between the field-generator coil and a receiver coil, measured through the current induced in the receiver coil. Also, validation criteria of the use of finite element analysis during the study of the interaction electromagnetic field - soil, were obtained. In present work, using this analysis method, the possibilities of sensing of soil compaction by means of the application of an electromagnetic variable field is studied. As a result, a high correlation (R²=0,96) among the soil electric conductivity and the density of the induced in a receiver coil current is obtained. Experimentally, increments of electric conductivity of a compacted red ferralític soil were evidenced with increases of soil moisture and compaction, measured through their apparent density. Soil electric conductivity and therefore induced voltage in the receiver coil, correlated with soil compaction, oscillating R² between 95,9 and 98,4% for different soil moisture levels. [ABSTRACT FROM AUTHOR]

A theoretical-experimental study of the electromagnetic field-soil interaction is made using the finite element simulation, as well as the experimentation in a soil container. As a result the influence on the soil response to the action of a variable electromagnetic field is determined in function of the excitement frequency of a field-generator coil and of the distance between the field-generator coil and a receiver coil, measured through the current induced in the last one. Validation criteria of the use of finite element analysis during the study of the interaction among a variable magnetic field with the soil are obtained. Also is obtained that the excitement frequency that causes the maximum induction in the receiver coil lies between 10000 and 15000 Hz, with a tendency to grow when coil distance is increased. It is appreciated that only in this range of frequencies it is possible to discriminate changes in soil electric conductivity by means of the electromagnetic field. It was determined, by finite element simulation, an exponential tendency to decrease the maximum density of the induced current in the receiver coil in function of coil distance, with an asymptote in the axis of the abscissas, that is interpreted like a null induction when the coil distance tends to infinite. The same tendency was obtained through the experimental way on a red feralitic compacted soil. [ABSTRACT FROM AUTHOR]

The present work was carried out in the Institute of Animal Science (ICA), located in San José de las Lajas, Havana county; in the development livestock unit (block), with the objective of determining the energetic, productive, and environmental contribution of the multi shovel windmills as an alternative source of water supply. To determinate the wind speed characteristics, available eolic power, power transmission efficiency and non-emitted contamination magnitude by the use of low speed multi shovel windmill. It was used the Danish Association of Eolic Industry methodologics. It was obtained a safe of 5 882,9 liters/year (4 929 kg/year) of fuel by the substitution of pumping electricity and water transportation by a water tanker, it was avoided the emission of 17,27 t/year of atmosphere pollutants. It was obtained an economic gain of 5882.94 peso/year and the investment will be recovered in 1,7 years. [ABSTRACT FROM AUTHOR]