Search results for "Atténuation"
showing 6 items of 6 documents
Contribution à l'étude des liaisons optiques atmosphériques : propagation, disponibilité et fiabilité.
2005
In this work we study the fog attenuation in the visible and infrared spectral band related to Free Space Optics (FSO). Based on the Mie scattering theory, fog extinction coefficients for different particle size distributions as a function of wavelength were derived. A simple analytical model allowing the prediction of atmospheric transmission for the 0.69 - 1.55 µm spectral band was developed. This model is valid for advection and convection fog and for visibility range between 50 to 1000 m. This model, implemented into software developed at FT R&D, allows the prediction of the Quality of Service of FSO links. Finally, we performed an experimental study to compare the fog effect on two FSO…
Legume inoculants to reduce soil emissions of nitrous oxide
2012
Nitrous oxide (N2O) is a potent greenhouse gas involved in depletion of the ozone layer and mainly arising from the soil and from agricultural activities. Within this framework, INRA teams inoculated soybean plants with natural strains of Rhizobia bacteria. Convincing results regarding the consumption of N2O greenhouse gases were obtained.
Atténuation des émissions par les sols du gaz à effet de serre N2O, grâce à l’utilisation d’additifs ou de microorganismes, tous d’origine naturelle
2021
National audience; Les sols agricoles sont la principale source du gaz à effet de serre (GES) N2O (protoxyded’azote). D’un point de vue environnemental ce gaz est impliqué à la fois dans l’effet de serreadditionnel et la destruction de la couche d’ozone stratosphérique. Le pouvoir de réchauffementglobal (PRG) du N2O sur une durée de 100 ans est 265 fois supérieur à celui du dioxyde decarbone (CO2). La durée de vie du protoxyde d’azote dans l’atmosphère est d’environ 120 ans.Ainsi, il apparait comme le 3ème gaz participant au réchauffement climatique d’origineanthropique, après le CO2 et le CH4. Les sols peuvent fonctionner comme source mais aussicomme puits de N2O, par l’intermédiaire de mé…
Climate change: where are we right now?
2019
15ème Rencontres Bourgogne-Franche-Comté Nature : Changement climatique, humanité et biodiversité; International audience; Greenhouse gases (GHGs), naturally part of the atmosphere, have protected us from severe glaciations in thepast. Today, human activities increase GHG concentrations and cause rapid and unprecedented Earth warming.Climate change is not resumed only to warming, water cycle is also changed. All the researches confi rm: the climateis changing fast, too fast for ecosystems and societies to adapt. Despite the alerts of the international scientifi ccommunity, States gathered into Conferences of the Parties (COP) ratify agreements but do not comply with all theircommitments. Pu…
Principaux processus impliqués dans l'atténuation naturelle des pesticides par les sols
2018
Prod 2018-253e EA BIOmE INRA; National audience
Le changement climatique : où en sommes-nous ?
2018
Greenhouse gases (GHGs), naturally part of the atmosphere, have protected us from severe glaciations in the past. Today, human activities increase GHG concentrations and cause rapid and unprecedented Earth warming. Climate change is not resume only to warming, water cycle is also changed. All the research confirms: the climate is changing fast, too fast for ecosystems and societies to adapt. Despite the alerts of the international scientific community, States gathered into Conferences of the Parties (COP) ratify agreements but do not comply with all their commitments. Public opinion polls indicate that climate change is perceived as a risk, but jobs and taxes override environmental concerns…