Search results for "CCI"
showing 10 items of 6325 documents
Regio- and Stereoselective Synthesis of 3-Pyrazolylidene-2-oxindole Compounds by Nucleophilic Vinylic Substitution of (E)-3-(Nitromethylene)indolin-2…
2019
[EN] A highly regio- and stereoselective synthesis of 3-alkylidene-2-oxindoles has been described through a nucleophilic vinylic substitution (SNV) of (E)-3-(nitromethylene)indolin-2-one using pyrazol-3-ones as nucleophiles and Et3N as a base. The reaction affords selectively the Z-isomer when pyrazol-3-ones without substituents at the 4 position are used. While the reaction is E-selective with 4- substituted pyrazolones. The stereoselectivity (up to >20:1) and the yields (up to 98%) are very high under mild reaction conditions.
Catalytic enantioselective aza-Reformatsky reaction with seven-membered cyclic imines dibenzo[b,f][1,4]oxazepines
2017
A catalytic enantioselective aza-Reformatsky reaction is reported with cyclic dibenzo[b,f][1,4]oxazepines and ethyl iodoacetate leading to the synthesis of chiral ethyl 2-(10,11-dihydrodibenzo[b,f][1,4]oxazepin-11-yl)acetate derivatives with excellent yields and high enantioselectivities (up to 98% yield and 97 : 3 er) using a readily available diaryl prolinol L4 as the chiral ligand and Me2Zn as the zinc source under an air atmosphere. Furthermore, different transformations were carried out with the corresponding chiral β-amino esters, preserving in all cases the optical purity.
An Ecohydrological Cellular Automata Model Investigation of Juniper Tree Encroachment in a Western North American Landscape
2016
Woody plant encroachment over the past 140 years has substantially changed grasslands in western North American. We studied encroachment of western juniper (Juniperus occidentalis var. occidentalis) into a previously mixed shrubâgrassland site in central Oregon (USA) using a modified version of Cellular Automata TreeâGrassâShrub Simulator (CATGraSS) ecohydrological model. We developed simple algorithms to simulate three encroachment factors (grazing, fire frequency reduction, and seed dispersal by herbivores) in CATGraSS. Local ecohydrological dynamics represented by the model were first evaluated using satellite-derived leaf area index and measured evapotranspiration data. Reconstruc…
Vegetation vulnerability to drought in Spain
2014
[EN] Frequency of climatic extremes like long duration droughts has increased in Spain over the last century.The use of remote sensing observations for monitoring and detecting drought is justified on the basis that vegetation vigor is closely related to moisture condition. We derive satellite estimates of bio-physical variables such as fractional vegetation cover (FVC) from MODIS/EOS and SEVIRI/MSG time series. The study evaluates the strength of temporal relationships between precipitation and vegetation condition at time-lag and cumulative rainfall intervals. From this analysis, it was observed that the climatic disturbances affected both the growing season and the total amount of vegeta…
Explosive eruptive history of Pantelleria, Italy: Repeated caldera collapse and ignimbrite emplacement at a peralkaline volcano
2018
A new, pre-Green Tuff (46 ka) volcanic stratigraphy is presented for the peralkaline Pantelleria Volcano, Italy. New 40Ar/39Ar and paleomagnetic data are combined with detailed field studies to develop a comprehensive stratigraphic reconstruction of the island.We find that the pre-46 ka succession is characterised by eight silicarich peralkaline (trachyte to pantellerite) ignimbrites,many ofwhich blanketed the entire island. The ignimbrites are typically welded to rheomorphic, and are commonly associated with lithic breccias and/or pumice deposits. They record sustained radial pyroclastic density currents fed by lowpyroclastic fountains. The onset of ignimbrite emplacement is typically prec…
Fluid storage and migration properties of sheared Neptunian dykes
2019
Abstract Neptunian dykes are widely reported along the Tethyan carbonate platforms and are commonly considered as subsurface baffles or barriers to fluid flow. However, the fluid storage and migration properties of sheared Neptunian dykes are poorly known. For this reason, we investigate the inner structure and fluid flow properties of two Neptunian dykes, which can be characterized by different architectures if involved or not in brittle shearing processes. The dykes strike ca. WNW-ESE and crosscutting the tight Jurassic limestones exposed at Maranfusa Mt., NW Sicily, Italy. The unsheared and sheared Neptunian dykes are almost sub-vertical and at high-angle with respect to the horizontal p…
The (de)politicisation of nuclear power: The Finnish discussion after Fukushima
2017
When the Fukushima accident occurred in March 2011, Finland was at the height of a nuclear renaissance, with the Government’s decision-in-principle in 2010 to allow construction of two new nuclear reactors. This article examines the nuclear power debate in Finland after Fukushima. We deploy the concepts of (de)politicisation and hyperpoliticisation in the analysis of articles in the country’s main newspaper. Our analysis indicates that Finnish nuclear exceptionalism manifested in the safety-related depoliticising and the nation’s prosperity-related hyperpoliticisation arguments of the pro-nuclear camp. The anti-nuclear camp used politicisation strategies, such as economic arguments, to sho…
The Early-Cambrian Boho volcano of the El Graara massif, Morocco: Petrology, geodynamic setting and coeval sedimentation
2006
15 pages; International audience; A major volcanic episode is recorded across the Neoproterozoic-Cambrian transition in the Moroccan Anti-Atlas. Several volcanic cones are still preserved in the El Graara massif, laterally correlatable with volcanic flows dated as Early Cambrian (U/Pb date of 534 ± 10 Ma). Volcanic ashes and flows are interbedded with the uppermost part of the Adoudou dolostones, whereas the best-preserved volcano (the Boho Jbel) is onlapped by the overlying Lie-de-vin strata. Available petro-geochemical data from the Boho volcano suggest an alkaline magmatism probably derived from low-grade melting of a garnet–lherzolite mantle source, followed by fractional crystallizatio…
Modelling forest decline using SMOS soil moisture and vegetation optical depth
2018
Global change is increasing the risk of forest decline worldwide, impacting carbon and water cycles. Hence, there is an urgent need for predicting forest decline occurrence. To that purpose, this study links forest decline events in Catalonia, detected by the DEBOSCAT forest monitoring program, with information from the Soil Moisture and Ocean Salinity (SMOS) satellite. Firstly, this study reviews the role of the SMOS soil moisture in a previous forest decline episode occurred in 2012, where the authors concluded that dry soils increased the probability of observing decline in broadleaved forests. Secondly, the present study detects that forest decline in 2012 and 2016 was linked to very dr…
Biomass and volume modeling in Olea europaea L. cv "Leccino"
2017
Key message: This work demonstrates that the Olive tree, which is managed and pruned as a fruit tree, can be treated as a forest tree using allometric equations, to estimate both biomass production and volumes. Abstract: The Olive tree (Olea europaea L.) is an evergreen tree that can grow and accumulate a relatively high amount of dry matter, even in dry environmental conditions common in the Mediterranean basin and typical of traditional rain-fed agriculture. The objective of this research was to develop a tool to predict woody biomass and tree component volume for the olive tree, to be used for different agricultural and environmental purposes. The study was carried out in six olive grove…