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Focardi, S. E.
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Focardi, S. E.
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7 results
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- PublicationRestrictedIntercomparison of IMGC Absolute and GWR SuperConducting Gravimeters(1995)
; ; ; ; ; ; ; ;Baldi, P.; Dipartimento di Fisica - Università di Bologna - Italy ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Focardi, S.; Dipartimento di Fisica - Università di Bologna - Italy ;Palmonari, F.; Dipartimento di Fisica - Università di Bologna - Italy ;Cerutti, G.; Istituto di Metrologia G. Colonnetti - Torino - Italy ;De Maria, P.; Istituto di Metrologia G. Colonnetti - Torino - Italy ;Marson, I.; DINMA - University of Trieste - Italy; ; ; ; ; ; ; ; ; ;Marson, I.; DINMA . University of Trieste - Italy ;Sunkel, H.; DMGG - University of Graz - Graz - Austria; In May 1994 a first comparison campaign between a superconducting and the IMGC absolute gravimeter has been performed in Brasimone, near Bologna in Italy. The superconducting gravimeter was previously calibrated by means of a moving ring, the mass of which has been measured with the highest accuracy allowed by the actual technology. During the three days of observation with the absolute gravity meter, a maximum, a complete semidiurnal curve and a minimum of the tidal effect has been observed. These data have been used to compute the calibration factor of the superconducting gravity meter; it agrees in a rather satisfactory way with the results of the calibration with the moving mass.161 29 - PublicationOpen AccessTidal analysis of data recorded by a superconducting gravimeter(1995-05)
; ; ; ; ;Baldi, P.; Dipartimento di Fisica and INFN, Università di Bologna, Italy ;Casula, G.; Istituto Nazionale di Geofisica, Roma, Italy ;Focardi, S.; Dipartimento di Fisica and INFN, Università di Bologna, Italy ;Palmonari, F.; Dipartimento di Fisica and INFN, Università di Bologna, Italy; ; ; A superconducting gravimeter was used to monitor the tidal signal for a period of five months. The instrument was placed in a site (Brasimone station, Italy) chat-acterized by a low noise level, and was calibrated with a precision of 0.2%. Then tidal analysis on hourly data was performed and the results presented in this paper; amplitudes, gravimetric factors, phase differences for the main tidal waves, M2, S2, N2, 01, Pl, K1, QI, were calculated together with barometric pressure admittance and long term instrumental drift.176 368 - PublicationRestrictedTesting Newton's inverse square law at intermediate scales(2001-08)
; ; ; ; ; ;Baldi, P.; Dipartimento di Fisica - Università di Bologna - Italy ;Campari, G.; Dipartimento di Fisica - Università di Bologna - Italy ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Focardi, S.; Dipartimento di Fisica - Università di Bologna - INFN Sezione di Bologna - Italy ;Palmonari, F.; Dipartimento di Fisica - Università di Bologna - INFN Sezione di Bologna - Italy; ; ; ; abstract - Here we report the results of a new analysis of the data obtained in the framework of an experiment consisting of the measurement of the gravitational signal induced by varying the water mass of a lake. a more precise calibration of the superconducting gravimeter used in the experiment has been performed with the use of an absolute instrument; furthemore, a knowledge of the absolute amplitude of the solid earth tides of the station have been improved. The result of this analysis shows an agreement between data and Newtonian theory to within a 0.17% level.271 20 - PublicationRestrictedTemporal trends and matrix-dependent behaviors of trace elements closed to a geothermal hot-spot source (Aeolian Archipelago, Italy)(2011)
; ; ; ; ; ; ; ; ;Renzi, M.; Research Centre in Lagoon ecology, fishery and aquaculture (Ecolab) Polo Universitario Grossetano, University of Siena, ;Romeo, T.; ISPRA – Higher Institute for Environmental Protection and Research, STS Palermo ;Guerranti, C.; Department of Environmental Science, University of Siena, ;Perra, G.; Department of Environmental Science, University of Siena, ;Italiano, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Focardi, S. E.; Department of Environmental Science, University of Siena, ;Esposito, V.; ISPRA – Higher Institute for Environmental Protection and Research, STS Palermo ;Andaloro, F.; ISPRA – Higher Institute for Environmental Protection and Research, STS Palermo; ; ; ; ; ; ; Degassing activity from marine shallow-water hydrothermal vents represents a natural important source of trace elements of particular ecotoxicological concern, such as Hg, Cd, Pb, and As. In 2002, on November 3rd, a submarine area of the Aeolian Archipelago (Italy) was affected by an exceptional hydrothermal activity, presumably associated to a significant trace element release. This study developed in the highest impacted area, was focused on different environmental matrices (water, sediment, primary producers, and fishes) with the aim to evaluate on a statistical basis temporal dynamics involving trace elements closed to the emission source. Results evidenced that this event produced significant changes in water column, modifying the general assessment of the chemical descriptors selected (Na, K, Mg, Ca, Cl, Br, SO4 2-, HCO3 -). Furthermore, the degassing activity represents a significant input of Hg, Cd, Pb, and As for all of the sampled matrices, being it responsible of the higher levels observed in the study area compared to controls. Concentrations measured in sediments and biota (Cystoseira compressa, Serranus cabrilla) at temporal intervals of ten months distanced, supported the occurrence of different time scale dynamics which are both element and matrix-dependent. In particular, levels of Cd and As measured in liver tissues of S. cabrilla evidenced a significant trend to increase with the time, allowing to exclude a quick recovery of the study area. Measured values in edible fishes tissues are, also, notably higher than risk limits proposed by the 2001/22/CE Directive for human consumption, so, local-based caught have to be accurately regulated to avoid the occurrence of diet over-exposure.401 18 - PublicationOpen AccessA calibration system for superconducting Gravimeters(1994-10)
; ; ; ; ; ; ; ; ;Achilli, V.; Istituto di Topografia - Università di Bologna - Italy ;Baldi, P.; Dipartimento di Fisica - Settore Geofisica - Università di Bologna - Italy ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Errani, M.; INFN - Sezione di Bologna - Italy ;Focardi, S.; Dipartimento di Fisica - Università di Bologna - Italy ;Guerzoni, M.; Dipartimento di Fisica - Settore Geofisica - Università di Bologna - Italy ;Palmonari, F.; Dipartimento di Fisica - Università di Bologna - Italy ;Ragunì, G.; Dipartimento di Fisica - Università di Bologna - Italy; ; ; ; ; ; ; A new method for the calibration of a superconducting gravimeter is described, in wihich a 273 Kg annular mass is placed around the meter and is moved up and down. The geometry of the apparatus is easy to model and the accuracy in the computation of the gravity variation induced by the mass, 6.7 microGal, is limited only by the accuracy in the knowledge of value of the gravitational constant. Measurements done in '91 and '92 for the calibration of the instrument GRW-T015 are described. The calibration factor has been determined with a precision of about 0.3%.308 254 - PublicationRestrictedGravitational constant G measured with a superconducting gravimeter(2005)
; ; ; ; ; ; ;Baldi, P.; Dipartimento di Fisica, Universita’ di Bologna, viale Berti-Pichat 6/2 40127 Bologna Italy ;Campari, E.; Dipartimento di Fisica, Universita’ di Bologna, viale Berti-Pichat 6/2 40127 Bologna Italy ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Focardi, S.; Dipartimento di Fisica, Universita’ di Bologna and INFN sezione di Bologna, viale Berti-Pichat 6/2 40127 Bologna Italy ;Levi, G.; Dipartimento di Fisica, Universita’ di Bologna and INFN sezione di Bologna, viale Berti-Pichat 6/2 40127 Bologna Italy ;Palmonari, F.; Dipartimento di Fisica, Universita’ di Bologna and INFN sezione di Bologna, viale Berti-Pichat 6/2 40127 Bologna Italy; ; ; ; ; We report in this paper the results of a measurement of the gravitational constant G obtained in a laboratory at distances of about 1 m, using a superconducting gravimeter. The instrument measured the gravitational effect due to an annular mass of about 280 kg moving up and down around the gravimeter. The experiment yielded for the gravitational constant the value G 6:675 0:007 10 11Nm2=kg2 which agrees, within its uncertainty, with the last CODATA value.219 36 - PublicationRestrictedA geophysical experiment on Newton's inverse-square law(1997-05)
; ; ; ; ; ; ; ;Achilli, V.; DISTART - University of Bologna - Bologna - Italy ;Baldi, P.; Dipartimento di Fisica - Università di Bologna - Italy ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Errani, M.; INFN - Sezione di Bologna - Italy ;Focardi, S.; Dipartimento di Fisica - Università di Bologna - Italy ;Palmonari, F.; Dipartimento di Fisica - Università di Bologna - Italy ;Pedrielli, F.; Dipartimento di Fisica - Università di Ferrara - Italy; ; ; ; ; ; A geophysical experiment consisting of the measurements of the gravitational effect produced by a large water mass was performed in order to verify the Newton's law. The use of a superconducting gravimeter, the detailed analysis of the local tidal perturbation, the precise topographic and geological surveys lead to a precision of about 0.1% in the final result. The ratio between the measured and the expected gravitational effect differs from 1 by more than 9 standard deviations. This may be explained by adding to the Newtonian potential a Yukawa repulsive term. The experimental result leads to constraints for the relationship between the relative magnitude (alpha)of the new term and the range (lambda) of the interaction. In the region 20 m < lambda > 500m, alpha ranges from 2.6% to 1.3%.227 26