Search results for "Missions"
showing 10 items of 380 documents
The Tropical Forest Ecosystem: Reviewing the Effects of Deforestation on Climate and Environment
1991
The rapid decline of tropical rain forests in the 1980s, particularly caused by man-made forest clearance for farmland and timber exploitation, is accompanied by adverse climatic and environmental effects. In particular, rainfall and temperature conditions are adversely changed, with lower rainfall and high-er temperatures. Through deforestation, the atmospheric emissions of CO2 are increased and thus the global greenhouse effect is being strengthened. Tropical deforestation also increases soil erosion, depending upon the type of ecosystem. It also can be seen that floods more often occur in cases of deforestation. An international “action programme” for the protection and preservation of t…
The Constraints of Vehicle Range and Congestion for the Use of Electric Vehicles for Urban Freight in France
2015
The 9th International Conference on City Logistics, Tenerife, Espagne, 17-/06/2015 - 19/06/2015; Electric vehicle is a solution to reduce pollutant emissions from road urban freight. This paper assesses the potential CO2 reduction by transferring urban freight from diesel to electric vehicles while simultaneously looking at the two main technical constraints: electric vehicle range and the impact on congestion linked to change diesel heavy duty vehicles (with a load up to 25 tons) to much smaller electric vehicles. The data used has been computed from a survey (ECHO) that describes in details a very large sample of French shipments. Two scenarios were set up, which differ mainly by the type…
Smart vs conventional motorways: environmental impact assessment under realistic traffic conditions
2020
Abstract This research aims at assessing the environmental impacts exerted by a smart motorway compared to those of a traditional motorway. The study has global policy implications: it takes into account the impacts due to the construction and maintenance of the infrastructure and the environmental effects produced by the traffic emissions, taking into account smart technologies and truck platooning regulation. Through a classical LCA approach, 1 km-long smart motorway with 2 m-high embankment was assumed as the functional unit for the analysis. A realistic traffic condition has been considered. A comparison between environmental effects produced by the use of virgin material and by Reclaim…
From COVID-19 to future electrification: Assessing traffic impacts on air quality by a machine-learning model
2021
The large fluctuations in traffic during the COVID-19 pandemic provide an unparalleled opportunity to assess vehicle emission control efficacy. Here we develop a random-forest regression model, based on the large volume of real-time observational data during COVID-19, to predict surface-level NO(2), O(3), and fine particle concentration in the Los Angeles megacity. Our model exhibits high fidelity in reproducing pollutant concentrations in the Los Angeles Basin and identifies major factors controlling each species. During the strictest lockdown period, traffic reduction led to decreases in NO(2) and particulate matter with aerodynamic diameters <2.5 μm by –30.1% and –17.5%, respectively, bu…
Expérimentation d'un outil d'aide à la décision : estimation de l’impact du télétravail sur les déplacements et les niveaux d’émission des gaz à effe…
2014
Dynamics of outgassing and plume transport revealed by proximal Unmanned Aerial System (UAS) measurements at Volcán Villarrica, Chile
2019
Volcanic gas emissions are intimately linked to the dynamics of magma ascent and outgassing, and, on geological timescales, constitute an important source of volatiles to the Earth's atmosphere. Measurements of gas composition and flux are therefore critical to both volcano monitoring and to determining the contribution of volcanoes to global geochemical cycles. However, significant gaps remain in our global inventories of volcanic emissions, (particularly for CO2, which requires proximal sampling of a concentrated plume) for those volcanoes where the near‐vent region is hazardous or inaccessible. Unmanned Aerial Systems (UAS) provide a robust and effective solution to proximal sampling of …
Nestandartu interneta vārdnīcu struktūra
2015
Spēja noteikt strukturālos elementus, kuri ir nepieciešami vārdnīca ssastādīšanai, ir būtiska leksikogrāfa prasme. Maģistra darba mērķis ir izanalizēt nestandarta vārdnīcas autoru un atbalstītāju strukturālās izvēles, kuras ir izmantotas individuālo projektu vārdnīcu saradīšanai. Mērķa sasniegšanai izmantotās metodes ir literatūras apraksts, lai formulētu teorētisko bāzi, un manuāla datu vākšana un aprakstoša analīze. Analīzes rezultāti atļāva identificēt defektus izvēlētajos struktūras elementos un apsvērt defektu ietekmi uz vispārējo vārdnīcas kvalitāti. Tomēr rezultāti arī liecināja, ka, neskatoties uz kļūdām, vārdnīcu autoriem ir dažas atkārtojošās izvēles struktūru organizācijā, lai ga…
The impact of foreign trade on the Netherlands' real CO2 emissions
2019
Aim: CO2 emissions and the related climate change are a global problem, where the direct impact of actions of individual countries depends on their total share in CO2 emissions. In order to assess the potential for policy measures, the openness of an economy, and the related import and export and their impacts on emissions should be considered. The aim of this paper is the attempt to show the real CO2 emissions of the Netherlands as well as the impact of its trade on CO2 emissions in other countries in the world and in the EU in 2015.Design / Research methods: This study was conducted on the group of countries that are the major emitters of CO2 in the world including most of the EU members.…
EDGE: explorer of diffuse emission and gamma-ray burst explosions
2009
How structures on various scales formed and evolved from the early Universe up to present time is a fundamental question of astrophysical cosmology. EDGE will trace the cosmic history of the baryons from the early generations of massive star by Gamma-Ray Burst (GRB) explosions, through the period of cluster formation, down to very low redshifts, when between a third and one half of the baryons are expected to reside in cosmic filaments undergoing gravitational collapse by dark matter (Warm Hot Intragalactic Medium: WHIM). In addition EDGE, with its unprecedented observational capabilities, will provide key results on several other topics. The science is feasible with a medium class mission …