1,008 research outputs found
A new European plant-specific emission inventory of biogenic volatile organic compounds for use in atmospheric transport models
We present a new European plant-specific emission inventory for isoprene, monoterpenes, sesquiterpenes and oxygenated VOC (OVOC), on a spatial resolution of 0.089×0.089 degrees, for implementation in atmospheric transport models. The inventory incorporates more accurate data on foliar biomass densities from several litterfall databases that became available in the last years for the main tree species in Europe. A bioclimatic correction factor was introduced to correct the foliar biomass densities of trees and crops for the different plant growth conditions that can be found in Pan-Europe. Long-term seasonal variability of agriculture and forest emissions was taken into account by implementing a new growing season concept. The 2004–2005 averaged annual total biogenic volatile organic compound (BVOC) emissions for the Pan-European domain are estimated to be about 12 Tg with a large contribution from the OVOC class of about 4.5 Tg and from monoterpenes of about 4 Tg. Annual isoprene emissions are found to be about 3.5 Tg, insensitive to the chosen emission algorithm. Emissions of OVOC were found to originate to a large extent from agriculture. Further experiments on crop emissions should be carried out to check the validity of the applied standard emission factors. The new inventory aims at a fully transparent and verifiable aggregation of detailed land use information and at the inclusion of plant-specific emission data. Though plant-specific land use data is available with relatively high accuracy, a lack of experimental biomass densities and emission data on terpenes, sesquiterpenes and oxygenated VOC, in particular for agricultural plants, currently limits the setup of a highly accurate plant-specific emission inventory
Land Grabbing and Human Rights: The Involvement of European Corporate and Financial Entities in Land Grabbing outside the European Union
Emission of monoterpenes from European beech (<i>Fagus</i><i> sylvatica</i> L.) as a function of light and temperature
International audienceUsing a dynamic branch enclosure technique European beech (Fagus sylvatica L.) was characterised as a strong emitter of monoterpenes, with sabinene being the predominant compound released. Since monoterpene emission was demonstrated to be a function of light and temperature, application of light and temperature dependent algorithms resulted in reasonable agreement with the measured data. Furthermore, during high temperature periods the depression of net CO2 exchange during midday (midday depression) was accompanied by a depression of monoterpene emission on one occasion. The species dependent standard emission factor and the light and temperature regulated release of monoterpenes is of crucial importance for European VOC emissions. All measurements were performed within the framework of the ECHO project (Emission and CHemical transformation of biogenic volatile Organic compounds) during two intensive field campaigns in the summers of 2002 and 2003
A Fast Reactor Lattice Experiment for Investigation of k(infinite) and Reaction Rate Ratios in SNEAK, Assembly 5
Picosecond Nonlinear Relaxation of Photoinjected Carriers in a Single GaAs/AlGaAs Quantum Dot
Photoemission from a single self-organized GaAs/AlGaAs quantum dot (QD) is
temporally resolved with picosecond time resolution. The emission spectra
consisting of the multiexciton structures are observed to depend on the delay
time and the excitation intensity. Quantitative agreement is found between the
experimental data and the calculation based on a model which characterizes the
successive relaxation of multiexcitons. Through the analysis we can determine
the carrier relaxation time as a function of population of photoinjected
carriers. Enhancement of the intra-dot carrier relaxation is demonstrated to be
due to the carrier-carrier scattering inside a single QD.Comment: 4 pages, 4 figures, to be published in Phys. Rev. B, Rapid
Accaparement de terres et droits de l'homme: rôle des sociétés et des entités financières européennes dans l'accaparement de terres en dehors de l'Union européenne
Dans les travaux de recherche antérieurs sur l'accaparement de terres, les auteurs se sont
initialement intéressés aux sociétés étrangères investissant dans d'autres pays et ont mis
notamment l'accent sur les sociétés implantées dans des pays tels que la Chine, les États du
Golfe, la Corée du Sud et l'Inde. Ces dernières années, il est devenu évident que la palette des
pays d'origine des investisseurs fonciers est bien plus large et comprend des acteurs
implantés en Atlantique Nord et dans l'Union européenne. Dans la présente étude, nous
fournissons des données qualitatives et quantitatives pour illustrer le rôle des entités
financières et des sociétés établies dans l'Union européenne dans les transactions foncières
opérées en dehors de l'Union. Cette étude analyse également le phénomène international de
"ruée vers la terre" avec les droits de l'homme en arrière-plan, en examinant les répercussions
de certaines transactions foncières auxquelles des investisseurs basés dans l'Union
européenne participent, ainsi que leurs effets sur les populations qui vivent dans les secteurs
visés par les investissements. Ces recherches s'appuient en partie sur l'étude réalisée en 2014
par Cotula sur les facteurs favorisant l'accaparement de terres et les répercussions de ce
phénomène sur les droits de l'homme, mais s'en écartent également par la façon dont
l'accent est mis expressément sur certains cas d'abus et de violations, potentielles ou
effectives des droits de l'homme dans le cadre d'activités dans lesquelles des sociétés et des
entités financières européennes sont impliquées. Dans nos conclusions, nous proposons une
série de recommandations sur la façon dont l'Union européenne peut s'attaquer de façon
efficace à ces problèmes
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