Encontrados 21 documentos, a visualizar página 1 de 3
Influence of seismic activity on the atmospheric electric field in Lisbon (Port...
Silva, H.G.; Oliveira, M.M.; Serrano, C.; Bezzeghoud, M.; Reis, A.H.; Rosa, R.N.; Biagi, F.In the present study, we considered the influence of seismic activity on the atmospheric electric field recorded at Portela meteorological station (Lisbon, Portugal) for the period from 1955 to 1991. To this end, an exploratory method was developed, which involved the selection of events for which the distance from the atmospheric electrical field sensor to the earthquake epicenter is smaller than the preparati...
Climate trends and behaviour of drought indices based on precipitation and evap...
Paulo, A.A.; Rosa, R.D.; Pereira, L.S.Distinction between drought and aridity is crucial to understand water scarcity processes. Drought indices are used for drought identification and drought severity characterisation. The Standardised Precipitation Index (SPI) and the Palmer Drought Severity Index (PDSI) are the most known drought indices. In this study, they are compared with the modified PDSI for Mediterranean conditions (MedPDSI) and the Stand...
Physics of Seismo-electromagnetic Phenomena
Silva, Hugo Gonçalves; Bezzeghoud, Mourad; Borges, J.F.; Bento, C.; Moita, P.; Serrano, C.; Reis, A.H.; Rosa, R.N.; Tlemçani, M.; Biagi, P.F.The seismo-electromagnetic phenomena (SEMG) are integrated in a relatively recent research field that studies diverse phenomena such as: unusual seismo-electrical signals [1], abnormal ultra-low-frequency (ULF) seismo-electromagnetic emissions [2], very-low-frequency (VLF) and low-frequency (LF) radiobroadcast anomalies associated with ionosphere perturbations [3], variation of total electron content of the ion...
Electric transport in different granitic rocks
Silva, Hugo Gonçalves; Graça, M.P.F.; Monteiro, J.S.; Bezzeghoud, Mourad; Rosa, R.N.; Mendiratta, S.K.; Tlemçani, M.; Moita, P.Many studies are being done to understand acoustic to electromagnetic conversion in rocks, [1], mainly because of the so-called seismo-electromagnetic phenomena (SEMG). Nevertheless, to our knowledge, most of them disregard a preliminary analysis of the electrical transport occurring in these rocks. These are, in fact, crucial to understand any electromagnetic process occurring in the materials since they clari...
Atmospheric electrical field suppression in the time of the M =4.1 Sousel earth...
Silva, Hugo Gonçalves; Serrano, C.; Reis, A.H.; Bezzeghoud, Mourad; Rosa, R.N.; Borges, J.F.; Caldeira, B.; Tlemçani, M.In recent years different phenomena associated with seismic events have been referred in the literature. These include: unusual ultra-low-frequency electromagnetic emissions [1]; anomalies in very-low and low-frequencies radio transmissions [2]; variation of the ionosphere total electron content [3]; and anomalous levels of different geochemical elements (in particular radon) in the earthquake preparation zone ...
Electromagnetic and acoustic coupling during mechanical action in porous media ...
Silva, Hugo Gonçalves; Graça, M.P.F.; Monteiro, J.H.; Bezzeghoud, Mourad; Rosa, R.N.; Mendiratta, S.K.; Tlemçani, MouhaydineElectromagnetic and acoustic coupling (EAC) during mechanical action, was theoretically predicted to occur in porous media [1] and was recently validated experimentally [2]. In fact, the exchange of acoustic waves to electromagnetic emissions is commonly referred in the literature as seismo-electromagnetic phenomena and is engaging a large number of geophysical groups on its study [3]. The reason for this inte...
Necessidades de água e produtividade económica da rega de milho em condições de...
Rodrigues, G.C.; Paredes, P.; Rosa, R.D.; Silva, F.G.; Pereira, L.S.A identificação das necessidades de rega do milho, uma das principais culturas regadas em Portugal Continental, constitui uma medida de preparação para enfrentar as secas e a escassez de água. Definiram-se várias estratégias de rega com o objectivo de redução da procura de água de rega com impactos aceitáveis na produção. O modelo de balanço hídrico e de simulação de calendários de rega SIMDualKc, anteriormente...
Estimación de las necessidades hídricas de la papaya utilizando la aproximación...
Chaterlán, Y.; Paredes, P.; Rosa, R.; Herández, G.; López, T.; Pereira, L.S.The use of irrigation in the cultivation of papaya is increasing in recent years. Thus, there is the need for improved knowledge of the most appropriate irrigation scheduling practices to be adopted as well as the more adequate estimation of crop water requirements. With this objective, the simulation model SIMDualKc was adopted and calibrated. The model performs the calculation of crop evapotranspiration (ETc)...
SEISMO-ELECTROMAGNETIC PHENOMENA IN TECTONICALLY ACTIVE REGIONS
Silva, H.G.; Bezzeghoud, M.; Biagi, P.F.; Tlemçani, M.; Rosa, R.; Reis, A.H.; Salgueira, M.A.; Caldeira, B.; Borges, J.F.; Manso, M.This work presents a research plan that aims to monitor seismo-electromagnetic signals in seismic active regions. Two effects will be considered: electromagnetic field emissions and radio broadcastings. Our study will be focused in the analysis of low magnitude earthquakes almost completely disregarded in literature. We aim to collect novel seismo-electromagnetic emission data emerging from seismic activity. We...
Electric properties of granitic rocks
Silva, H.G.; Tlemçani, M.; Albino, A.; Bezzeghoud, M.; Rosa, R.; Caldeira, B.; Borges, J.F.The objective of this work is to clarify the role of water content on the charge trans- port mechanisms of different granitic rocks. The mineralogical content of the rocks will also be taken into account. From the electrical point of view these materials are rather insulating porous media where charge injection creates different phenomena like build-up charges, space charge limited currents, surface effects and...
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