156 research outputs found

    Preliminary design of a RESPER probe prototype, configured in a multi dipole-dipole array.

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    The RESPER probe has been assembled, except the metallic points that must ensure the contact, by insulating materials and more specifically in Tufnol, as regards the support plates, and Teflon, as regards the standoffs. A series of holes has been drilled on the surface of support plates in order to allow approaching each other of the two central electrodes to external ones, from a minimum of 4.29 cm to a maximum of 10 cm, as shown in the table of configurations. The dipole-dipole array defined by the integer parameter n = 6 could not be implemented, as the positioning of suitable “spring” poles requires 6 mm holes and an adequate space could not be available to carry out the drilling. The presence of these “spring” poles allows reaching a right prominence of the tip from the base and, at the same time, a certain amount of pressure which ensures the proper adherence to the artifact that must be tested. There is a brass screw within each pole, which edge has been turned to the measurement of 1.4 mm. Four metal spacers are replaced of time in time depending on the configuration that is to be adopted. The achievement of height l(n) from the plates is ensured by the presence of metallic spacers, which dimensions are reported. To complete the description, a copper cable, 1 m long and with a 4.0 mm2 section area, has been welded to the head of each electrode. The two transmitting or reading cables are kept at a fixed distance L(n) between them by means of Teflon rods in which has been applied the same series of holes existing on the Tufnol plates

    Non-inductive components of electromagnetic signals associated with L’Aquila earthquake sequences estimated by means of inter-station impulse response functions

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    On 6 April 2009 at 01:32:39 UT a strong earthquake occurred west of L’Aquila at the very shallow depth of 9 km. The main shock local magnitude was Ml = 5.8 (Mw=6.3). Several powerful aftershocks occurred the following days. The epicentre of the main shock occurred 6 km away from the Geomagnetic Observatory of L’Aquila, on a fault 15 km long having a NW-SE strike, about 140 , and a SW dip of about 42 . For this reason, L’Aquila seismic events offered very favourable conditions to detect possible electromagnetic emissions related to the earthquake. The data used in this work come from the permanent geomagnetic Observatories of L’Aquila and Duronia. Here the results concerning the analysis of the residual magnetic field estimated by means of the inter-station impulse response functions in the frequency band from 0.3 Hz to 3 Hz are shown

    Geomagnetic survey of Italy. Repeat station network and magnetic maps: a short report

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    Starting in 1977, two geomagnetic project were undertaken in the frame of the >of the Consiglio Nazionale delle Ricerche(Project>of the National Research Council);1)a new national network of repeat stations for total field F, horizontal component H, vertical component Z, declination D.2)a 2nd order network of stations for F,Z,H to produce geomagnetic maps of Italy. The two projects were carried out by a > made up of Operating Units from Institutions to which the authors belong. The field work ended in 1981. The Istituto Nazionale di Geofisica coordinated the operations for both projects. This paper is intended to give a short report to the international scientific community on this work which has so far only appeared in the Italian literature.Published365-3681A. Geomagnetismo e PaleomagnetismoN/A or not JC

    Geomagnetic survey of Italy at 1979.0 Repeat station network and magnetic maps

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    attached an anomaly map for FA national network of 106 repeat stations for total field F, horizontal component H, vertical component Z and declination D has been undertaken in the frame of the 'Progetto Finalizzato Geodinamica' of the Consiglio Nazionale delle Ricerche. From the observed magnetic elements the repeat station values were referred to 1979.0 and five normal fields in the form of a 2nd order polynomial in latitude and longitude were computed: GDN for the whole Italian area, GDN-N for the northern Italy, GDN_C for central Italy, GDN-S for the southern Italy and GDN-Sn for Sardinia. From comparisons made on F between GDN and two planetary reference fields it has concluded that for total field the polynomial form can be well considered as representative of the main field in the Italian area. A 2nd order network of 2500 stations for F, Z, H, has been undertaken to produce geomagnetic maps of Italy. An anomaly map for F referred to the GDN normal field has been drawn. The main features of anomalies configuration are described.Published1-171A. Geomagnetismo e PaleomagnetismoN/A or not JC

    Un semplice esperimento sulla propagazione delle onde elettromagnetiche nei mezzi materiali. Proposta d'un'esposizione didattica.

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    Esperimento di propagazione delle onde e.m. in mezzi materiali, riproducibile per la didattica nella scuola secondari

    Metodologie geoelettriche per lo studio del sottosuolo

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    Dopo una breve introduzione sui metodi geoelettrici e la loro utilitĂ  in idrogeologia, ne viene descritta un'applicazione alla caratterizzazione di acquiferi di acqua dolce a valle della linea delle risorgive, nel territorio tra Villotta e S. Vito al Tagliamento (PN, Italia
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