Search results for "Trace"

The contribution of volcanoes to the atmospheric trace metals budget in the Mediterranean basin

2009

Volcanic emissions represent one of the major natural source for several trace metals (Cd, Cu, As, Pb, Hg and Zn) into the atmosphere both as gaseous and aerosol forms. The Mediterranean Sea can be considered a large geochemical sink for these elements whose source are the huge amounts of aerosols of different origin. The industrialised areas located in the northern part of the basin represent a nearly constant source of the anthropogenic-dominated aerosol. By contrast, the arid and desert regions located at the southern and eastern parts of the Mediterranean, are the sources of frequent dust “pulses” perturbing the “steady-state” conditions of the local atmosphere through the input of seve…

Sedimentary record of anthropogenic chemical and organic pollution in a Mediterranean coastal area (Gulf of Palermo, Italy).

2009

The relatively high influx of unregulated industrial and domestic effluents has progressively degraded the Palermo coastal environment in NW Sicily. To evaluate the poorly known effects of these inputs on the Palermo Gulf, three sediment box-cores were collected along a transect perpendicular to the coast, in front of the Oreto river mouth, in water depths of 20—750 m. The samples, dated by 210Pb and 137Cs, were analysed for concentration of major/trace elements, total polycyclic aromatic hydrocarbon (PAH), total organic carbon (TOC) and for organic carbon and nitrogen isotopic compositions. Total organic carbon concentrations show relatively high values (0.4—2.9%), with a decreasing seawar…

Geochemical comparison of natural and anthropogenic metal fluxes in extreme environments: Mt. Etna volcano (Italy) and Šalek Valley (Slovenia)

2009

Geochemical comparison between some metals (As, Cd, Cu, Pb, Se, V, Zn) emissions from an active volcano (Mt. Etna) and a highly industrialized area (Šalek Valley) showed some interesting similarities: in general, most of the elements emitted into the atmosphere do not return to the Earth’s surface and are therefore dispersed into the environment. Exceptions for Šalek Valley are Cd, which probably derives in large part from rock leaching, and in part As and Pb, which fall mostly as ash. Also, Etna’s emissions are richer in Cd and Cu, whereas industrial emissions at Šalek Valley are richer in V and Zn. All other metals have similar fluxes in the two types of emissions.

Volcanic soil-rainwater interaction at Mount Etna, Sicily. Preliminary Results

2008

Local maximal operators on fractional Sobolev spaces

2016

In this note we establish the boundedness properties of local maximal operators MG on the fractional Sobolev spaces Ws;p(G) whenever G is an open set in Rn, 0 < s < 1 and 1 < p < 1. As an application, we characterize the fractional (s;p)-Hardy inequality on a bounded open set by a Maz'ya-type testing condition localized to Whitney cubes. pq(G) whenever G is an open set in R n , 0 < s < 1 and 1 < p;q <1. Our main focus lies in the mapping properties of MG on a fractional Sobolev space W s;p (G) with 0 < s < 1 and 1 < p < 1, see Section 2 for the denition or (3) for a survey of this space. The intrinsically dened function space W s;p (G) on a given domain G coincides with the trace space F s …

A Models-to-Program Information Systems Engineering Method

2021

The Model-Driven Development paradigm aims to represent all the information system features through models. Conceptual-Model Programming offers a similar approach, but with a focus on automatic code generation. Both approaches consider modeling and traceability of different abstraction levels, where each level can be tackled with different modeling methods. This heterogeneity introduces a challenge for the quality of the traceability and transformations among models, especially when aiming for automatic code generation. In this paper, we introduce a holistic conceptual-model programming method to generate code from different abstraction levels (from the problem space to the solution space),…

An integrated approach of analytical chemistry

1999

The tremendous development of physical methods of analysis offers an impressive number of tools to simultaneously determine a large number of elements and compounds at very low concentration levels. Todays Analytical Chemistry provides appropriate media to solve technical problems and to obtain correct information about chemical systems in order to take the most appropriate decisions for problem solving. In recent years the development of new strategies for sampling, sample treatment and data exploitation through the research on field sampling, microwaveassisted procedures and chemometrics, additionally the revolution of the analytical methodology provided by the development of flow analysi…

The International Measurement Evaluation Programme (IMEP) IMEP-6: "Trace elements in water"

1998

The sixth round of the International Measurement Evaluation Programme (IMEP) is presented. The programme offers reference values, established by primary methods of measurement, against which participating laboratories can evaluate their performance. The degree of comparability is thus established against the most objective references available at present. In IMEP-6, reference values for total concentrations of 14 trace elements in a synthetic and a natural water were established mainly by isotope dilution mass spectrometry (IDMS). For the majority of the measurands, results traceable to the international system of units (SI) and having expanded uncertainties, U (k=2), of 2% could be establi…

G-Sica 10.1

2013

SOMMAIRE :-*- Introduction / Marc Veyrat ; -1- ©box : InterMade pour un dispositif de médiation ? / Marc Veyrat ; mise en forme graphique Floriane Roussel, Delphine Lorenzetti ; -2- U-RSS en point de fuite. Symposium Texte & Image : une mise en voyage, Université de Malte, 2012 / Franck Soudan, Marc Veyrat ; mise en forme graphique Clara Blanchet, Lise Haudebourg ; -3- Kiss & Fly [ est une oeuvre interactive qui interroge la notion de paysage comme une rencontre de tous les paramètres identitaires d'un lieu ] / Carole Brandon et Arnaud Burgniard ; mise en forme graphique Marie-Albéric Martin, Arnaud Burgniard ; -4- eMotion. Pour une mobilité multi-sensorielle / Ghislaine Chabert, Marc Veyra…

From attachment to damage: defined genes of Candida albicans mediate adhesion, invasion and damage during interaction with oral epithelial cells.

2010

Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by penetrating through epithelial barriers. C. albicans is an unusual pathogen because it can invade epithelial cells via two distinct mechanisms: induced endocytosis, analogous to facultative intracellular enteropathogenic bacteria, and active penetration, similar to plant pathogenic fungi. Here we investigated the molecular basis of C. albicans epithelial interactions. By systematically assessing the contributions of defined fungal pathways and factors to different stages of epithelial interactions, we provide an expansive portrait of the processes an…