323,092 research outputs found
Omero. Odissea, traduzione e riscrittura di G. Monti, illustrazioni di E. Diliberto, prefazione di S. Nicosia, Nuova Ipsa, Palermo 2010, pp. 7-8.
No full textTemperature of the ground, measured near surface, at Etna volcano (N-E Rift), Italy, hourly recorded in situ from 2009 to 2012
No full textThe dataset consists of temperature measurements of the porous ground (loose volcanic breccia). The temperature data were acquired for 3 years, from 30 September 2009 to 14 September 2012. Name of the station BTL, site location Latitude: 37.780675° Longitude: 15.008787°. BTL station was located at a distance of about 120 m (meters) from the fumarole vents that developed at an altitude of about 2470 m a.s.l. (above sea level) on Mt. Etna's North-East Rift. Approximate location of the fumarole vents: 33S 500740E; 4181593N. The volcanic feature that suggested the label for the monitoring station (BTL) is the neighbor “Bottoniera Line of craters”, on the northern flank of Etna. The temperature data have been recorded on a vertical line of four PT1000 sensors (temperature range of –40 °C to 150 °C, accuracy ±0.2 °C, resolution ±0.1 °C); the distance between each sensor was 0.15 m, thus the total depth of the monitored profile was 0.60 meter. A data-logger (model EBRO EBI 2T-313 four-channel) protected by a watertight case, acquired and stored data every hour, for about three years. The stored data file was downloaded once, at the end of the monitoring period, and none touched the probes in the monitored site during the monitoring period of time. The uploaded file includes all the raw measurements for the temperature profiles showing a linear correlation (R2) higher than 0.990 because these have been used by the author for further evaluations of the heat flux from the ground, possibly related to the volcanic activity (Diliberto et al., 2018 (doi:10.1007/s00445-018-1198-0); Diliberto & Gennaro, 2022(doi:10.3390/app12094471)). The profiles of temperature showing a not ideal linear fitting (R2 lower than 0.990) have been filtered out from the dataset
Convective heat flux from hydrothermal system: First monitoring results at La Fossa of Vulcano
No full textFluids circulating inside hydrothermal systems drive thermal and kinetic energy to balance the acting forces. Convective heat flux variations can be affected either by change in regional tectonic factor and by magma migration, both processes accountable for volcanic risk. The thermal release on quiescent volcano is not negligible if compared to that associated to eruptions, according to balances on hydrothermal activity and eruptive activity (Nuccio & Valenza, 1986, Chiodini et al., 2001). Moreover outlet temperature of La Fossa fumaroles (Vulcano, Aeolian Islands), indicates that thermal energy release is not stationary (Chiodini et al., 1992), showing relationships either with changes in the magmatic components of fluids and with seismic energy release (Badalamenti et al 1987, Nuccio et al 2000, Diliberto et al 2002). However at Vulcano, to estimate the time variation of convective heat flux, mainly steam output has been measured so far (Italiano & Nuccio ,1992; Italiano et al., 1998)…(b).. Indeed some interesting changes of heat flux from soil have been recorded, in 1998 and in 2004-2005, with anew method tested out of fumarole area. The first variation was related to the seismic crisis of November 1998 (Aubert & Alparone, 2000, Diliberto & Alparone, 2004); the second one (November 2004) was probably due to both magmatic fluids migration and little seismic activity. These results indicate that with this method future changes in the heat power (range or distribution) could be monitored to obtain new clues on the evolution of the activity.PublishedIstituto Nazionale di Geofisica e Vulcanologia Palermo1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attiveope
Convective heat flux from hydrothermal system: First monitoring results at La Fossa of Vulcano
No full textFluids circulating inside hydrothermal systems drive thermal and kinetic energy to balance the acting forces. Convective heat flux variations can be affected either by change in regional tectonic factor and by magma migration, both processes accountable for volcanic risk. The thermal release on quiescent volcano is not negligible if compared to that associated to eruptions, according to balances on hydrothermal activity and eruptive activity (Nuccio & Valenza, 1986, Chiodini et al., 2001). Moreover outlet temperature of La Fossa fumaroles (Vulcano, Aeolian Islands), indicates that thermal energy release is not stationary (Chiodini et al., 1992), showing relationships either with changes in the magmatic components of fluids and with seismic energy release (Badalamenti et al 1987, Nuccio et al 2000, Diliberto et al 2002). However at Vulcano, to estimate the time variation of convective heat flux, mainly steam output has been measured so far (Italiano & Nuccio ,1992; Italiano et al., 1998)…(b).. Indeed some interesting changes of heat flux from soil have been recorded, in 1998 and in 2004-2005, with anew method tested out of fumarole area. The first variation was related to the seismic crisis of November 1998 (Aubert & Alparone, 2000, Diliberto & Alparone, 2004); the second one (November 2004) was probably due to both magmatic fluids migration and little seismic activity. These results indicate that with this method future changes in the heat power (range or distribution) could be monitored to obtain new clues on the evolution of the activity.PublishedIstituto Nazionale di Geofisica e Vulcanologia Palermo1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attiveope
Long-term variations of fumarole temperatures on Vulcano Island (Italy)
No full textFumarole temperatures are the ultimate results of many processes that are encountered by deep fluids during their passage to the surface. Here, the time variations of high-temperature fumaroles acquired by continuous monitoring are presented, to show the effects of the forces that act on the system. Data acquired by continuous monitoring of fumaroles and the time relationships with the different parameters related to the activity of the volcanic system are discussed. From 1998 to 2010, the temperature and compositional changes of fumarolic gases were monitored at the same time as variations in the number of volcano-seismic events, which indicate frequent variations of energy release (heat and mass flow, and seismic strain release). Geochemical modeling applied to the volcanic system of Vulcano Island suggests that the overall expansion of magmatic gas through the fractured system is an almost iso-enthalpic process at depth, which shifts to an adiabatic process at shallow depth, where the rock permeability increases. Thus, the time variations of the fumarole temperatures reflect various physical variations of the system that can either occur at depth or close to the surface. The temperature monitoring performed in the fumarolic area of La Fossa Cone showed short-term effects related to rain events, and negligible effects related to other external agents (ambient temperature and atmospheric pressure variations). At the same time, the long-term monitoring highlighted some mean-term and long-term variations. These last are the main characters observed in the time-series, and they both appear to be related to endogenous forces that perturb the equilibrium of this complex geochemical system.<br />
Time series analysis of high temperature fumaroles monitored on the island of Vulcano (Aeolian Archipelago, Italy)
No full textThe continuous monitoring shows short term dynamics and allows multidisciplinary comparisons. Sharp increases and trending variations were recorded in fumarole temperatures. The trends highlighted by punctual monitoring characterized the main fumaroles. A new phase of increasing temperature begun after the year 2001 at the rim fumaroles.The exhalation activity at the La Fossa cone (Vulcano Island, Aeolian Archipelago, Italy) has been ongoing for more than 1 century. Many of the monitored geochemical and geophysical parameters have showed transient
variations of energy release. The time-series analyses of fumarole temperatures presented in this paper enabled
the sequence of observations to be defined and information from different monitoring stations to be integrated. The motion of fluids feeding the fumaroles of the La Fossa cone is driven by the thermal and kinetic energies that balance the seismic and volcanic forces active in the region, and the temperatures of the fumaroles reflect the
local response of the hydrothermal system to these forces. During a 14-year period of observation, from 1998 to 2012, fumarole temperatures showed various trends but also cyclic variations characterized by sharp increases. The repetition of these variations during periods with different trends indicates that no physical variation
occurred from the hydrothermal source to the surface during the analyzed period, and after each periodic geochemical crisis the previous thermal conditions were restored. Although the continuous monitoring of hightemperature fumaroles was limited to only a few sites, the observed trends characterized the most important fumaroles in the area of Vulcano Island. An evaluation of thermal-energy release based on these spatially discrete measurements would be a speculative exercise in thermodynamics, but the analyses of the recorded data represent
a step forward in interpreting the signals from ongoing volcanic activity and in assessing the seismic risk.
© 2013 Elsevier B.V. All rights reserved.INGV-DPC projectPublished150-1631.2. TTC - Sorveglianza geochimica delle aree vulcaniche attiveJCR Journalrestricte
EVALUATION OF THE DNA BARCODING APPROACH IN HYPERICUM SPP. DISCRIMINATION
No full textHypericum, with more than 450 species, is widespread in temperate zones all over the world.
In Italy 30 taxa are known (1), 26 species and 4 subspecies; ten of them are native to Sicily, in addition to H. calycinum which is recoded as naturalized.
Hypericum biochemical compounds (flavanols, flavonoids, cumarins, glicosidys, terpens, tannins, essential oils) are well recognized for many pharmacological activities: antiflogistic, improving blood flow, against traumas, in wounds and burns recovering. The most important activity is ascribed to the hipericyn, a compound especially derived from Hypericum perforatum L., with successfully application in anti-depressive phytotherapy.
The medical relevance and the related commercial interest push for improving the taxonomic identification method to dispose of certain plant material. Methods for fast and accurate identification of plant species are required to support morphological characterization.
In this study the potential of the “DNA Barcoding” molecular method was investigated in discriminating the Italian Hypericum taxa in order to develop an easy authentication assay helpful in solving taxonomic doubts or in commercial trade traceability of whole plants, portions or derived products.
The samples range was mainly recovered from native habitats in Italy, during the flowering period. Some samples were also sourced from certified herbarium collection.
The DNA extraction was carried in three biological replicates, according to CTAB protocol for plant material (2). The DNA bank and also the ex-situ collection are stored at CRA-SFM of Bagheria.
The three plastid regions, rbcL, matK and trnH-psbA, were assessed, according to the CBOL Plant Working Group indications (3). Phylogenetic analysis of each molecular marker were conducted by comparing sequences including those available from international databases (BOLD/NCBI) based on Kimura 2-parameter (4). The preliminary results indicate the effectiveness of this method in discriminating the taxa of Hypericum, suggesting the possibility to build a fast and accurate molecular identification method by barcode
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