34 research outputs found
CONTRIBUTION AU DESIGN, STABILITÉ, PERFORMANCE ET OPTIMISATION D’UN UAV
Ce travail porte sur la simulation numérique, l’étude de performance, la stabilité et l’optimisation d’un modèle de drone (PIPER CUB J3).Dans ce but plusieurs logiciels de conception et de dessin assisté par ordinateur ont été utilisés : le modèle de l’UAV est conçu sous le logiciel « SolidWorks », les étapes de maillage et résolution des équations de Navier-Stokes décrivant l’écoulement sous « Ansys 16.0 », l’étude de stabilité et performance de vol par « Advanced Anlysis Aircraft 2.5 ».Pour des fins d’optimisation et d’amélioration en termes de finesse et d’endurance, trois types d’ailette ont été étudié
Organic pollutants in sea-surface microlayer and aerosol in thecoastal environment of Leghorn—(Tyrrhenian Sea)
The levels of dissolved and particle-associated n-alkanes, alkylbenzenes, phthalates, PAHs, anionic surfactants and
surfactant fluorescent organic matter ŽSFOM. were measured in sea-surface microlayer ŽSML. and sub-surface water ŽSSL.
samples collected in the Leghorn marine environment in September and October 1999.
Nine stations, located in the Leghorn harbour and at increasing distances from the Port, were sampled three times on the
same day. At all the stations, SML concentrations of the selected organic compounds were significantly higher than SSL
values and the enrichment factors ŽEFsSML concentrationrSSL concentration. were greater in the particulate phase than
in the dissolved phase.
SML concentrations varied greatly among the sampling sites, the highest levels Žn-alkanes 3674 mgrl, phthalates 177
mgrl, total PAHs 226 mgrl. being found in the particulate phase in the Leghorn harbour.
To improve the knowledge on pollutant exchanges between sea-surface waters and atmosphere, the validity of spray drop
adsorption model ŽSDAM. was verified for SFOM, surface-active agents, such as phthalates, and compounds which can
interact with SFOM, such as n-alkanes and PAHs. q2001 Elsevier Science B.V. All rights reserved