Search results for "Vulcan"

Effects of functionalized carbon nanotubes in peroxide crosslinking of diene elastomers

2009

Abstract The crosslinking reaction of ethylene–propylene–diene terpolymer (EPDM) peroxide vulcanization filled with pristine and functionalized carbon nanotubes (CNTs and S/CNTs) was evaluated by rheometric tests. The functionalization of CNTs was carried out by diazonium salt methodology in acid medium. S/CNTs were characterised by means of TGA, EDX, Raman and elemental analysis. Pristine CNTs were found to gradually increase the delta torque as a function of loading fraction. Nevertheless, the vulcanization time, scorch and optimum cure time hardly varied on addition of CNTs. However, S/CNTs noticeably affected the cure process, reducing the vulcanization time and delta torque. This effec…

Time series of PM2.5, PM2.5–10, PM10 and their interrelationships in the airborne particulate matter from Palermo.

2009

Astronomic forcing on the planktonic foraminifera assemblage in the Piacenzian Punta Piccola section (Southern Italy).

2006

Trace elements in Mirror of Venus lake waters (Pantelleria Island, Italy)

2016

Mirror of Venus lake (MV) is a small (1.5 km2) endorheic alkaline lake located in a calderic depression on the northern side of Pantelleria Island (South Italy), a quiescent Pleistocenic stratovolcano located in the NW-SE trending continental rift developed between North Africa and Sicily. The lake, sub-squared in shape (around ca 450 m long and ca 350 m wide and 13 m depth) water input contribution is essentially from the thermal springs situated on its shores (Q = 0.1 l.s-1) and from meteoric waters. A total volume of 580.000 m3 has been estimated in June 2014. CO2 flux measurements made with a floating accumulation chamber in 2014 on the MV surface (both diffusive and bubbling CO2) highl…

Clay minerals, oxyhydroxide formation, element leaching and humus development in volcanic soils

2008

Aweathering sequence with soils developing on volcanic, trachy-basaltic parent materials with ages ranging from 100–115,000 years in the Etna region served as the basis to analyse and calculate the accumulation and stabilisation mechanisms of soil organic matter (SOM), the transformation of pedogenic Fe and Al, the formation and transformation of clay minerals, the weathering indices and, by means of mass-balance calculations, net losses of the main elements. Although the soils were influenced by ash depositions during their development and the soil on the oldest lava flow developed to a great extent under a different climate, leaching of elements and mineral formation and transformation co…

Distribution of rare earth elements in marine sediments from the Strait of Sicily (western Mediterranean Sea): Evidence of phosphogypsum waste contam…

2010

Concentrations of rare earth elements (REE), Y, Th and Sc were recently determined in marine sediments collected using a box corer along two onshore–offshore transects located in the Strait of Sicily (Mediterranean Sea). The REE + Y were enriched in offshore fine-grained sediments where clay minerals are abundant, whereas the REE + Y contents were lower in onshore coarse-grained sediments with high carbonate fractions. Considering this distribution trend, the onshore sediments in front of the southwestern Sicilian coast represent an anomaly with high REE + Y concentrations (mean value 163.4 lg g 1) associated to high Th concentrations (mean value 7.9 lg g 1). Plot of shale-normalized REE + …

Contribution of isotopic geochemistry to the origin of lead in the atmosphere of Sicily.

2001

Air quality can be assessed using mineral and biological indicators: airborne particulate matter, mosses, lichens, and pine needles. However, the origin of the pollutant is usually difficult to determine on the sole basis of concentrations, particularly when many sources are involved. In this study, we report some examples of application of lead isotopic geochemistry on airborne particulate matter, lichens and pine needles as a mean to decipher sources of lead pollution in Sicily. Furthermore, we evaluate the use of Pb/Sc and Pb/Br ratios to enhance the discriminating power of the isotopic method. Besides the methodological aspect, this work aims to provide, at least for lead, a summary of …

First measurements of magmatic gas composition and fluxes during an eruption (October 2010) of Piton de la Fournaise hot spot volcano, La reunion isl…

2011

Piton de la Fournaise (PdF), in the western Indian Ocean, is a very active hot spot basaltic volcano, with 1-2 fissure eruptions per year on average. Its magmas have been widely studied and its eruptions are well anticipated by the local seismic-geodetic monitoring network. However, no datum was yet available for its magmatic gas emissions (restricted to only eruptive phases and hardly accessible). Here we report on the first measurements of the chemical composition and mass flux of magmatic gases emitted during a PdF eruption in October 2010. Hot gases arising from different eruptive vents were remotely measured with OP-FTIR spectroscopy, using molten lava fragments as IR radiation source,…

New insight into halogen release from experimental studies on BrO/Br ratios in volcanic plumes

2014

Recognition of Trace Element Contamination Using Ficus macrophylla Leaves in Urban Environment

2020

Urban areas are characterized by numerous pollutants emitted by anthropic sources both in the form of solid and gaseous particulates. Biomonitoring is an easy, economical, and accessible approach for the determination of atmospheric pollutants. In this study, we used the leaves of Ficus macrophylla Desf. ex Pers., collected in the city of Palermo (Italy), to determine major and trace elements. Geogenic elements exhibited the highest concentrations, making up 99% of the weight of the analyzed elements (Ca, K, Mg, P, S, Na, Fe, and Al)