647 research outputs found
Feeling political across borders: International solidarity movements, 1820s-1980s
International audienceAbstract As the long history of international solidarity movements throughout the nineteenth and twentieth centuries demonstrates, emotions fostered a sense of common belonging in the name of so-called universal brotherhood, solidarity of peoples, or defence of human rights. Investigating exemplary political mobilizations in Europe that transcended national borders, such as the Philhellenism of the 1820s, the solidarity movements during the Spanish Civil War (1936–1939), and against the Chilean dictatorship in the 1970s and 1980s, helps to illustrate the strengths but also the limits of these feelings. These movements, which shaped and were shaped by individual and collective emotions such as compassion, fear, and anger, but also enthusiasm and hope, developed a complex relationship with patriotism and universalism, as well as with the state and other political institutions
Inundation mapping based on reach-scale effective geometry
The production of spatially accurate representations of potential inundation
is often limited by the lack of available data as well as model complexity.
We present in this paper a new approach for rapid inundation mapping, MHYST,
which is well adapted for data-scarce areas; it combines hydraulic geometry
concepts for channels and DEM data for floodplains. Its originality lies in
the fact that it does not work at the cross section scale but computes
effective geometrical properties to describe the reach scale. Combining
reach-scale geometrical properties with 1-D steady-state flow equations,
MHYST computes a topographically coherent relation between the height above
nearest drainage and streamflow. This relation can then be used on a past
or future event to produce inundation maps. The MHYST approach is tested here
on an extreme flood event that occurred in France in May–June 2016. The
results indicate that it has a tendency to slightly underestimate inundation
extents, although efficiency criteria values are clearly encouraging. The
spatial distribution of model performance is discussed and it shows that the
model can perform very well on most reaches, but has difficulties modelling
the more complex, urbanised reaches. MHYST should not be seen as a rival to
detailed inundation studies, but as a first approximation able to rapidly
provide inundation maps in data-scarce areas.</p
Petrology, mineralogy, and geochemistry of the olivine diogenite NWA 4255: new insights into the magmatic evolution of asteroid 4 Vesta
Northwest Africa (NWA) 4255 is a meteorite found in the region of Tindouf (southwestern Algeria), classified as brecciated olivine diogenite. Based on textural observations and orthopyroxene compositions, two different lithologies were determined: harzburgitic and orthopyroxenitic. The orthopyroxenitic lithology contains orthopyroxene (Mg no. 73.99–75.68) and spinel (Cr no. 83.09–85.11, Mg no. 15.57–22.45). On the other hand, the harzburgitic lithology contains orthopyroxene (Mg no. 74.54–77.14) and olivine (Mg no. 70.94–72.57). The iron metal and the sulfides (Troilites) of this sample are present in both lithologies and are low in Ni (Ni < 0.1 wt%). The Fe/Mn ratio of orthopyroxenes ranges from 22.28 to 32.64 and show a large overlap between both lithologies. Lowest ratios are unusual; they are below the defined field for diogenites and olivine diogenites. ∆17O values are − 0.234 ± 0.003 (1σ) and confirm that the NWA 4255 originated from 4Vesta. The results of this study show that there is a genetic linkage between the two lithologies of NWA 4255 and correspond to in situ crystallization processes. This olivine diogenite reflects transition between two major magmatic processes in 4Vesta. The magma ocean of 4Vesta crystallized at equilibrium, allowing the formation of a dunitic and harzburgitic mantle. This late lithology is linked to the peritectic reaction between the olivines formed and the evolved liquid. Our sample then reflects this crucial step of separating this mantle from the residual liquid. This melt evolving on the peritectic allowed the formation of the observed harzburgitic assemblage and then evolves out from the peritectic reaction to proceed to a fractional crystallization process involving the formation of orthopyroxenite
Comment passer d'un modèle hydrologique à un système de prévision des crues? Ecueils liés à la structure des modèles et aux échelles d'espace et de temps
Les modèles hydrologiques Pluie Débit sont des outils très utiles pour la prévision des crues. À l'heure actuelle, il n'est pas possible d'utiliser directement les modèles de simulation pour effectuer une bonne prévision. Nous explorons ici les différences entre modèles de simulation et modèles de prévision. Puis nous examinons l'importance relative des informations apportées au modèle : dans le passé, les forçages climatiques et les dernières observations de débit ; dans le futur, les prévisions de précipitations. La question des échelles spatiales est ensuite abordée et les limites d'une approche globale sont discutées dans une perspective opérationnelle. / Rainfall Runoff models are very useful tools for flood forecasting. As of today, the direct use of simulation models is not possible to get accurate predictions especially when it concerns short-term forecasting. In this paper, we explore the main differences between simulation and forecasting models. Then we assess the relative importance of every information provided to the model: the past climatic forcing and the last observed discharges; the future precipitation scenarios. Spatial scales are also examined and the limits of a global forecasting approach for operational purposes are discussed
Location of the Energy Levels of the Rare-Earth Ion in BaF2 and CdF2
The location of the energy levels of rare-earth (RE) elements in the energy
band diagram of BaF2 and CdF2 crystals is determined. The role of RE3+ and RE2+
ions in the capture of charge carriers, luminescence, and the formation of
radiation defects is evaluated. It is shown that the substantial difference in
the luminescence properties of BaF2:RE and CdF2:RE is associated with the
location of the excited energy levels in the band diagram of the crystals
The molecular priming of defense responses is differently regulated in grapevine genotypes following elicitor application against powdery mildew
Community‐specific impacts of exotic earthworm invasions on soil carbon dynamics in a sandy temperate forest
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116978/1/ecy201394122827.pd
Non in terra ne in acqua. La laguna nord attraverso l'archeologia di un'isola. San Lorenzo d'Ammiana. Catalogo della mostra, Inaugurazione 19 Maggio 2010, Isola di San Lazzaro degli Armeni, Venezia
Thulium and ytterbium-doped titania thin films deposited by MOCVD
In this study we synthesized thin films of titanium oxide doped with thulium
and/or ytterbium to modify the incident spectrum on the solar cells. This could
be achieved either by photoluminescence up-converting devices, or
down-converting devices. As down-converter thin films our work deals with
thulium and ytterbium-doped titanium dioxide. Thulium and ytterbium will act as
sensitizer and emitter, respectively. The rare-earth doped thin films are
deposited by aerosol-assisted MOCVD using organo-metallic precursors such as
titanium dioxide acetylacetonate, thulium and ytterbium
tetramethylheptanedionate solved in different solvents. These films have been
deposited on silicon substrates under different deposition conditions
(temperature and dopant concentrations for example). Adherent films have been
obtained for deposition temperatures ranging from 300{\deg}C to 600{\deg}C. The
deposition rate varies from 0.1 to 1 \mu m/h. The anatase phase is obtained at
substrate temperature above 400{\deg}C. Further annealing is required to
exhibit luminescence and eliminate organic remnants of the precursors. The
physicochemical and luminescent properties of the deposited films were analyzed
versus the different deposition parameters and annealing conditions. We showed
that absorbed light in the near-UV blue range is re-emitted by the ytterbium at
980 nm and by a thulium band around 800 nm.Comment: 4 pages, 6 figures, proceedin
Development and exploitation of a controlled vocabulary in support of climate modelling
There are three key components for developing a metadata system: a container structure laying out the key semantic issues of interest and their relationships; an extensible controlled vocabulary providing possible content; and tools to create and manipulate that content. While metadata systems must allow users to enter their own information, the use of a controlled vocabulary both imposes consistency of definition and ensures comparability of the objects described. Here we describe the controlled vocabulary (CV) and metadata creation tool built by the METAFOR project for use in the context of describing the climate models, simulations and experiments of the fifth Coupled Model Intercomparison Project (CMIP5). The CV and resulting tool chain introduced here is designed for extensibility and reuse and should find applicability in many more projects
- …