Search results for "Conti"
showing 10 items of 3486 documents
The oldest rocks of Greece: first evidence for a Precambrian terrane within the Pelagonian Zone
2005
The Pelagonian Zone in Greece represents the westernmost belt of the Hellenide hinterland (Internal Hellenides). Previous geochronological studies of basement rocks from the Pelagonian Zone have systematically yielded Permo-Carboniferous ages. In this study we demonstrate, for the first time, the existence of a Precambrian crustal unit within the crystalline basement of the Pelagonian Zone. The U–Pb single-zircon and SHRIMP ages of these orthogneisses vary from 699 ± 7 Ma to 713 ± 18 Ma, which identify them as the oldest rocks in Greece. These Late Proterozoic rocks, which today occupy an area of c. 20 × 100 km, are significantly different from the neighbouring rocks of the Pelagonian Zone.…
Pan-African granulite formation in the Kabye Massif of northern Togo (West Africa): Pb−Pb zircon ages
2000
Metamorphic zircons from seven granulite facies orthogneisses of tonalitic composition (ender- bites), collected from four different nappes of the Kabye Massif in the Dahomeyide belt of northern Togo, were dated by the Pb-Pb evaporation method. They yielded consistent Neoproterozoic ages with a mean of 612.5 0.8 Ma, interpreted to reflect the peak of regional granulite facies metamorphism following Pan-African continental collision between the West African and Benin-Nigerian plates. These results sup- port previous ages obtained by various chronometers on high-grade rocks from the same suture zone and from surrounding units in Togo, Benin and Ghana. They are also similar to zircon ages fr…
Avaluació continua con Goodle-GMS a més de 800 alumnes en Enginyeria Química.
2014
L'objectiu d'aquesta experiència ha estat la d'establir un sistema d'avaluació contínua en assignatures amb gran quantitat d'alumnes de manera que no suposin un excessiu treball per al docent, que permeti generar una retroalimentació als alumnes ràpida, de manera que estimuli el treball dels estudiants. L'experiència ha estat realitzada simultàniament a 859 alumnes matriculats de l'assignatura "Química", corresponent a 1r dels Graus d'Enginyeria de l'Energia (85), Enginyeria Aeroespacial (137), Enginyeria de les Tecnologies Industrials (459) i Enginyeria Química (141), durant el segon quadrimestre a l'Escola Tècnica Superior d'Enginyeria de la Universitat de Sevilla. S'han plantejat 5 probl…
Unified thermodynamic framework for nonlocal/gradient continuum theories
2003
Abstract A thermodynamic framework, equipped with the concept of nonlocality (energy) residual, is utilized to address nonlocal/gradient internal variable material models. A unified procedure is provided for either nonlocal and gradient materials, which makes it possible to determine the thermodynamic restrictions upon the constitutive equations, and in particular the pertinent state equations, the consistent form of the dissipation power and the constitutive expression of the nonlocality residual. Additionally, for gradient models, the associated nonstandard boundary conditions are derived, pointing out their basically constitutive nature and their substantial differences from the standard…
Functionnalized magnetite nanoparticles for bimodal imaging MRI/PET
2015
Functionalized magnetite nanoparticles for bimodal MRI/PET imagingSuperParamagnetic Iron Oxide Nanoparticles (SPIONs) have been widely studied in the biomedical field due to their promising application as nanodrugs and MRI (Magnetic Resonance Imaging) contrast agents (T2). In this study, magnetite (Fe3O4) nanoparticles have been developed for use as contrast agents for MRI/PET (Positron emission tomography) double imaging. First, functionalized stable superparamagnetic SPIONs have been synthesized in a continuous hydrothermal reactor. During the synthesis, hydrophilic agents (citric acid, LDOPA, DHCA and PHA) have been grafted on the surface of the nanoparticles. The functionalization of th…
Tutta la Russia è il nostro giardino
2018
Anton Chekhov lived in a tumultuous period that strongly influenced the future of Russia: he was a conscious and careful observer of this changing political landscape. Parallel examination of Chekhov’s drama and short stories yield the most complete understanding of his realism. The contents of his short stories are explicitly connected with the subject matter of his later plays. Gorky disagreed with the critics who, after the first productions of Chekhov’s plays, had characterized Chekhov’s as a ‘simbolic realism’. He saw in the playwright’s approach a unique ability for capturing and communicating universal meaning.
Un poeta maledetto ad Atene: Napoleon Lapathiotis
2015
Napoleone Lapathiotis (1888-1944), amante delle letterature e delle arti, è un singolare esempio di esteta nel panorama letterario greco all'inizio del XX secolo. Ispirato da Oscar Wilde, ha cercato di vivere la sua vita come un'opera d'arte, ma la fine è stata tragica a causa dei suoi problemi personali e del complesso contesto storico. La sua opera letteraria (poesie, racconti, poesie in prosa), sebbene convenzionale per quanto riguarda la forma, rispecchia le contraddizioni della sua vita e personalità. Napoleon Lapathiotis (1888-1944), lover of literatures and arts, is a peculiar example of an aesthete in the Greek literary landscape at the beginning of 20th century. Inspired by Oscar W…
An E-Factor Minimized Protocol for a Sustainable and Efficient Heck Reaction in Flow
2014
A highly sustainable and waste-minimized protocol for Heck coupling has been defined. Optimal conditions have been defined by exploiting a heterogeneous catalyst based on supported ionic liquid-like phases featuring high Pd loading (10 wt %) and by optimizing its efficiency in a recoverable green reaction medium (acetonitrile/water azeotrope). Pure products 4a–l and 6a–h have been isolated chromatography-free in high yields (74–99%) and with extremely low environmental factor (E-factor) values (2.3–5.0). With the application of flow technology, the selected heterogeneous base and Pd catalyst have been fully recovered and reused, and minimum palladium leaching allowed for isolation of the fi…
Quantifying the contribution of nitrification and denitrification to the nitrous oxide flux using 15N tracers.
2006
8 pages; International audience; Microbial transformations of nitrification and denitrification are the main sources of nitrous oxide (N2O) from soils. Relative contributions of both processes to N2O emissions were estimated on an agricultural soil using 15N isotope tracers (15NH4+ or 15NO3-), for a 10-day batch experiment. Under unsaturated and saturated conditions, both processes were significantly involved in N2O production. Under unsaturated conditions, 60% of N-N2O came from nitrification, while denitrification contributed around 85-90% under saturated conditions. Estimated nitrification rates were not significantly different whatever the soil moisture content, whereas the proportion o…
Geoacoustic Inversion with Drifting Buoys: Enverse 1997–98 Experiments (Marettimo Is.)
2000
Acoustic buoys were developed to allow the rapid determination of range-dependent bottom properties in a shallow water environment from the inversion of propagation measurements. The main features of the buoys are the large dynamic range, digital signal conditioning unit, global positioning system receiver and reliable radio data link. The buoys drift away from a broadband source receiving its pings at known positions. Single hydrophone, matched waveform, inversion techniques are applied to the received signals to invert for geoacoustic parameters. Eight prototypes were tested over the southern continental shelf off the island of Marettimo (Sicily) during the EnVerse 97 sea trials. Calibrat…