Search results for " TRACE"
showing 10 items of 221 documents
Major and trace elements characterization of atmospheric deposition in volcanic, urban, and industrial areas of Sicily (Italy): preliminary results
2022
The source of chemical elements dissolved in rainwater can be both natural and anthropogenic. A group of trace elements has been recently brought to attention for their possible environmental impacts, the Technology-critical elements (TCEs). The current knowledge about the geochemical cycle of TCEs is still scarce, nevertheless recent studies [e.g. Brugnone et al., 2020] evidenced a contribution from the volcanic activity for some of them (Te, Tl, and REE). Our research aims to produce a geochemical database on major and trace element depositions in different areas of Sicily: a volcanic area (Etna), two urban areas (Palermo, Catania), two industrial areas (Milazzo, Priolo), and a rural moni…
Geochemical and eco-toxicological evaluations in box-core sediments from the Sicilian coast, central Mediterranean
2007
Analytical model for the long- distance tracer-transport in plants
2011
International audience; Recent investigations of long-distance transport in plants using non-invasive tracer techniques such as C radiolabeling monitored by positron emission tomography (PET) combined with magnetic resonance imaging (MRI) revealed the need of dedicated methods to allow a quantitative data analysis and comparison of such experiments. A mechanistic compartmental tracer transport model is presented, defined by a linear system of partial differential equations (PDEs). This model simplifies the complexity of axial transport and lateral exchanges in the transport pathways of plants (e.g. the phloem) by simulating transport and reversible exchange within three compartments using j…
Active biomonitoring (moss-bags) of volcanic emissions on Mt. Etna
2011
Biomonitoring may be defined as the use of organisms and biomaterials (biomonitors) to obtain information on certain characteristics of a particular medium (atmosphere, hydrosphere etc.). In particular, mosses accumulate large amounts of trace metals, making them good bioaccumulators to estimate atmospheric pollution. The moss-bags technique, introduced in the early 1970’, has become very popular. Such active biomonitoring technique is particularly useful in highly polluted areas and has been extensively used in industrial and/or urban areas to examine deposition patterns and to recognize point sources of pollution. The main objective of this study, which represents the first application of…
New results and review of major and trace element output from worldwide passive degassing volcanoes
2013
Microsoft Dynamics Ax 2012 ātrdarbības uzlabošana
2015
Microsoft Dynamics Ax 2012 ir jaunākais produkts no Microsoft Dynamics Ax produktu saimes. Lai jaunie un esoši klienti būtu apmierināti sistēmas, ir jānodrošina ātra un stabila tās darbība. Bakalaura darba mērķis ir Microsoft Dynamics Ax 2012 ātrdarbības analīze un uzlabošana. Darba teorētiskajā daļā tiek apskatīta Microsoft Dynamics Ax 2012 sistēmas uzbūve un ātrdarbības testēšanas rīki. Darba praktiskajā daļā tiek veikti sistēmas ātrdarbības testi, un veiktas izmaiņas sistēmas konfigurācijā un programmas kodā. Darba rezultātā tika panākts sistēmas ātrdarbības uzlabojums.
Chemical and isotopic characterization of rainwater in volcanic, urban and industrial areas of Sicily (Italy)
2021
The chemical composition of rainwater depends on (i) the dissolution of gases and particulate matter emitted by different sources, (ii) the chemical and physical reactions occurring during local and regional scale transport, and (iii) removal processes. The source of major and trace elements dissolved in rainwater can be both natural (e.g. sea salts, volcanic emissions, geogenic dust, biogenic material) and anthropogenic (e.g. industrial plants, vehicular traffic, domestic heating, vessel traffic). A group of trace elements has been recently brought to attention, especially for their possible environmental impacts, the Technology-critical elements (TCEs): Ga, Ge, In, Te, Nb, Ta, Tl, the Pla…
THE IMPACT OF VOLCANIC EMISSIONS ON ETNA’S SNOW COVER
2011
Aristóteles entre doxografía y biografía: sobre Diógenes Laercio V 31
2019
Se pretende llamar la atención sobre un par de frases que aparecen justo hacia la mitad de la controvertida doxografía de Aristóteles que se puede leer en las Vidas y doctrinas de los filósofos más ilustres de Diógenes Laercio V 31, y que desde luego no corresponden a ningún sistema doxográfico conocido. Como sucede no pocas veces en la obra laerciana, la misma apreciación sobre si el filósofo debe o no enamorarse y contraer matrimonio se repite idéntica en otras doxografías completamente distintas: la cirenaica (DL II 91), la estoica (DL VII 129) y la epicúrea (DL X 118). Cabe plantearse, pues, el origen de este interés, en varias doxografías, por la vida sentimental, podríamos decir, de l…
Fish introductions and light modulate food web fluxes in tropical streams : a whole-ecosystem experimental approach
2016
Decades of ecological study have demonstrated the importance of top-down and bottom-up controls on food webs, yet few studies within this context have quantified the magnitude of energy and material fluxes at the whole-ecosystem scale. We examined top-down and bottom-up effects on food web fluxes using a field experiment that manipulated the presence of a consumer, the Trinidadian guppy Poecilia reticulata, and the production of basal resources by thinning the riparian forest canopy to increase incident light. To gauge the effects of these reach-scale manipulations on food web fluxes, we used a nitrogen (15N) stable isotope tracer to compare basal resource treatments (thinned canopy vs. con…