Literatura académica sobre el tema "Composés biogéniques volatiles"
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Artículos de revistas sobre el tema "Composés biogéniques volatiles"
Kalogridis, Athina-Cerise, Valérie Gros, Bernard Bonsang, Roland Sarda-Esteve, Anne-Cyrielle Genard, Christophe Boissard, Catherine Fernandez et al. "Étude des composés organiques volatils biogéniques émis par une forêt méditerranéenne". La Météorologie 8, n.º 93 (2016): 42. http://dx.doi.org/10.4267/2042/59940.
Texto completoFarhat, Mariana. "Origine anthropique des composés terpénoïdes en atmosphère urbaine". La Météorologie, n.º 125 (2024): 027. http://dx.doi.org/10.37053/lameteorologie-2024-0033.
Texto completoLuchetta, Laurent, Valérie Simon y Liberto Torres. "Émission des principaux composés organiques volatils biogéniques en France". Pollution atmosphérique, N°167 (2000). http://dx.doi.org/10.4267/pollution-atmospherique.3096.
Texto completoTesis sobre el tema "Composés biogéniques volatiles"
Oumami, Safae. "Impact d'un climat à +2°C sur les émissions des composés biogéniques volatils et sur la qualité de l'air". Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSEP013.
Texto completoOnce Volatile Organic Compounds (VOCs) are released into the atmosphere, they play a major role in altering its chemistry and composition, consequently impacting the global climate. VOCs released from natural sources account for 90% of the total emitted VOCs, which makes Biogenic Volatile Organic Compounds (BVOCs) a key contributor to the formation of several air pollutants. The influence of BVOCs goes beyond air quality concerns, as they can impact the climate through the formation of aerosols which have a cooling effect and greenhouse gases which have a warming effect, thus effecting the Earth's net radiative forcing. Conversely, climate can effect the release of biogenic species through global warming, land cover and land use change, drought and increasing atmospheric CO2 concentrations. The present work aims to evaluate how BVOCs emission will evolve in a +2°C climate change conditions and how this change will effect air quality in the future.For this purpose, a consequent work was undertaken to couple the SURFEX (SURface Externalisée in French) and MEGAN (Model of Emission of Gases and Aerosols from Nature) models. The coupled model SURFEX-MEGAN will allow the simulation of future emissions of biogenic species along with other important emission key drivers such as leaf area index, soil moisture, soil temperature, etc.The impact of climate change on isoprene emissions was assessed by conducting two global simulations representing present- and future-climate conditions over 2010-2014 and 2046-2050, respectively. The results of this study indicate a global increase of isoprene emissions by 13% (40Tg). This change account for the effect of temperature, solar radiation and atmospheric CO2 concentrations. Temperature have the highest positive effect. Solar radiation have a negative effect as it decreased under the SSP3-7.0 scenario and CO2 concentrations have both positive and negative effects. The former arises from the CO2 fertilization effect and the latter from the CO2 inhibition effect. The SURFEX-MEGAN results were confronted to other projections from CMIP6 models. Most of the models predicted a positive trend in future isoprene emissions. The disparities in model results are attributed to variations in isoprene schemes, resolution, vegetation distribution, and density, but most importantly, each model’s output of temperature and solar radiation differed, despite employing the same SSP scenario.The study of the impact of climate change on future ozone levels showed that the ozone burden will increase by 5% in 2050 compared to 2013. This change is mainly due to the change in human-induced NOx and VOC emissions. Although ozone's sensitivity to isoprene is high, the inclusion of future changes in isoprene emissions have only a marginal effect on global ozone trends. However, this effect is significant at regional and local scales, where ozone is positively and negatively correlated to isoprene trends in high and low NOx regions, respectively. The impact of isoprene emissions in future air quality is most significant when neglecting the inhibitory effect of CO2 on isoprene emissions. In this case air quality was predicted to improve at a global scale and in tropical regions particularly in the future compared to a future-climate scenario with present-climate isoprene emissions
Chrayteh, Mhamad. "Caractérisation physico-chimique de composés organiques volatils biogéniques et de leurs hydrates". Thesis, Lille, 2018. http://www.theses.fr/2018LIL1R054.
Texto completoOur study deal on the physicochemical properties of molecules of atmospheric interest in the gas phase, in particular the microsolvation process, which could be useful to better understand what leads to the formation of secondary organic aerosols. We studied the mechanism of hydration of several oxidation products of monoterpenes, which include myrtenal and perillaldehyde, which are two unsaturated aldehydes of close structures, with the verbenone and the fenchone, which are two ketones. The structures of many conformers (up to 3 molecules of water bound to molecules) have been optimized by quantum chemistry calculations at MP2 / 6-311++G(d,p) and B3LYP-D3BJ / def2-TZVP levels of theory. The hydrates cohesion is done thanks to hydrogen bonds and Van der Waals interactions. We were able to evidence of the existence of many of them by supersonic jet mircowave spectroscopy in the range of frequencies 2 - 20 GHz and determine their experimental structure. For the myrtenal, we recorded and analyzed the pure rotation spectra, as well as those of isotopologists in natural abundance (13C and 18O ). With the support of quantum chemistry calculations, we have determined its molecular structure in the gas phase. Regarding the hydrates of myrtenal, we analyzed the spectra of 2 mono-, 2 di- and a trihydrate, while for perillaldehyde 4 mono- and 2 dihydrates are characterized. With ketones, we analyzed the spectra of 2 mono-, 2 di- and 1 trihydrate of verbenone, while for the microhydration of fenchone, we characterized2 mono-, 2 di- and 3 trihydrates. In order to confirm the structure of the complexes, we used water enriched with oxygen 18, which allowed us through the constants of rotation of the isotopomers to calculate the structure of the detected hydrates by determining the position of the oxygen atoms by calculating their substitution coordinates, as well an effective structure limited to the arrangement of water molecules around the substrate
Chrayteh, Mhamad. "Caractérisation physico-chimique de composés organiques volatils biogéniques et de leurs hydrates". Electronic Thesis or Diss., Université de Lille (2018-2021), 2018. http://www.theses.fr/2018LILUR054.
Texto completoOur study deal on the physicochemical properties of molecules of atmospheric interest in the gas phase, in particular the microsolvation process, which could be useful to better understand what leads to the formation of secondary organic aerosols. We studied the mechanism of hydration of several oxidation products of monoterpenes, which include myrtenal and perillaldehyde, which are two unsaturated aldehydes of close structures, with the verbenone and the fenchone, which are two ketones. The structures of many conformers (up to 3 molecules of water bound to molecules) have been optimized by quantum chemistry calculations at MP2 / 6-311++G(d,p) and B3LYP-D3BJ / def2-TZVP levels of theory. The hydrates cohesion is done thanks to hydrogen bonds and Van der Waals interactions. We were able to evidence of the existence of many of them by supersonic jet mircowave spectroscopy in the range of frequencies 2 - 20 GHz and determine their experimental structure. For the myrtenal, we recorded and analyzed the pure rotation spectra, as well as those of isotopologists in natural abundance (13C and 18O ). With the support of quantum chemistry calculations, we have determined its molecular structure in the gas phase. Regarding the hydrates of myrtenal, we analyzed the spectra of 2 mono-, 2 di- and a trihydrate, while for perillaldehyde 4 mono- and 2 dihydrates are characterized. With ketones, we analyzed the spectra of 2 mono-, 2 di- and 1 trihydrate of verbenone, while for the microhydration of fenchone, we characterized2 mono-, 2 di- and 3 trihydrates. In order to confirm the structure of the complexes, we used water enriched with oxygen 18, which allowed us through the constants of rotation of the isotopomers to calculate the structure of the detected hydrates by determining the position of the oxygen atoms by calculating their substitution coordinates, as well an effective structure limited to the arrangement of water molecules around the substrate
Renard, Pascal. "Photochimie et oligomérisation des composés organiques biogéniques en phase aqueuse atmosphérique". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4748.
Texto completoAir pollution caused by secondary organic aerosol (SOA) is one of the major challenges of this century. We focus this thesis on SOA , through an innovative approach, i.e. multiphase photochemistry.The photochemical reactor allows to simulate in laboratory, the atmospheric aqueous phase oxidation of biogenic volatile organic compounds (BVOC) and in particular, methyl vinyl ketone (MVK), and thus, to study SOA.We study the reactivity of MVK in the presence of ●OH and its ability to oligomerize under various initial concentrations of oxygen, MVK and ●OH. A wide analytical strategy based on liquid chromatography-mass spectrometry is used to identify the reaction products, and establish a chemical mechanism. We focus on these oligomers systems, formation, yield and aging. Collected data are used as inputs to a multiphase box model to explore the sensitivity of oligomerization to the variations of physical and chemical atmospheric parameters. The photochemistry of pyruvic acid generates radical chemistry and initiates MVK oligomerization. We closely compare this reaction to MVK ●OH oxidation. Then, we measure the surface activity of both systems. The ability of oligomers to partition to the interface could affect the climate. Finally, we used ion mobility - mass spectrometry to observe ●OH co-oligomerization of a mixture of organic compounds most representative of the atmosphere.Atmospheric oligomerization implies (i) a minimal concentration of precursors that could be reached in wet aerosol via the co-oligomerization; (ii) a reactivity in competition with the addition of the dissolved oxygen, whose the atmospheric relevance remains to be explored
Mermet, Kenneth. "Caractérisation physico-chimique et réactivité d'espèces biogéniques sur un site de mesure en forêt des Landes : impacts sur la qualité de l'air". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0363.
Texto completoAt the global scale, forests are the largest emitters of VOCs. Once released into the atmosphere, VOCs will be fastly oxidized to oxygenated compounds. Depending on their volatility and reactivity, these oxidation products may themselves be re-oxidized, remain in the gas phase and/or be transferred to the particulate phase to form secondary organic aerosols (SOAs). This thesis aimed to better characterize biogenic VOC concentrations (BVOCs) and more especially their reactivity with atmospheric oxidants (i.e. the hydroxyl radical (OH), ozone (O3) and the nitrate radical (NO3)), in order to identify the main precursors of SOA formation within a maritime pine forest. The metrological development of a gas chromatographic analyzer has made possible the online and specified measurement of 20 BVOCs including isoprene, α- and β-pinene, 2 and Δ3-carene, α- and γ-terpinene, linalool, camphene, etc. This analyzer and some other instruments for the measurement of trace gases and aerosols were used during the summer of 2017 as part of the LANDEX intensive campaign in one of the largest pine forests in Europe (> 95% Pinus pinaster) located in the southwest of France. A principal component analysis of meteorological data and BVOC measurements showed that BVOC concentrations were mainly dependent on their emissions, the ambient temperature, the solar irradiation and the atmospheric stability. The analysis of the reactivity of the identified VOCs with the main atmospheric oxidants has helped to show the contrast between processes involving OH radical during daytime and ozonolysis at night. Finally, it was determined that the ozonolysis of β-caryophyllene, α-pinene, myrcene, and linalool, and the OH initiated oxidation of isoprene were the main sources of oxidation products, as SOA precursors, within the Landes forest
Baghi, Romain. "Emissions biogéniques de composés organiques volatils en région méditerranéenne - développement instrumental, mesures et modélisation". Phd thesis, Université Paul Sabatier - Toulouse III, 2013. http://tel.archives-ouvertes.fr/tel-00873143.
Texto completoBaghi, Romain. "Émissions biogéniques de composés organiques volatils en région méditerranéenne : développement instrumental, mesures et modélisation". Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2248/.
Texto completoVolatile Organic Compounds (VOC) play an important role in atmospheric chemistry and are involved in the formation of secondary atmospheric pollutants as ozone and organic aerosols. Biogenic emissions of volatile organic compounds are tenfold greater than anthropogenic emissions on a global scale but their characterization remains uncertain regionally. Advances in atmospheric chemistry modeling rely on better emission inventory which needs in situ flux measurement. This work focuses on biogenic VOC emissions from Mediterranean vegetation in the frame of ChArMEx (Chemistry and Aerosol Mediterranean Experiment) that aims to concentrate scientific effort to study atmospheric chemistry and aerosols in the Mediterranean region. The Eddy Covariance (EC) method allows direct measurement of trace gas exchange between the surface and the atmosphere. EC is a reference method for flux measurement but is adapted to only a limited number of trace gas species because it requires simultaneous fast measurement (~ 0. 1 s) of the species concentration and vertical wind speed. In order to broaden the range of applicability of this method, several other methods derived from EC have been proposed. Among these, the Disjunct Eddy Covariance (DEC) method relaxes the constraint on fast concentration measurement while preserving good accuracy on the flux calculation. In the frame of this PhD work, a sampling system dedicated to the DEC method for VOC flux measurement was developed. This device called MEDEE (Mesures par Échantillonnage Disjoint des Échanges d'Espèces en trace) relies on a novel technology that allows the rapid capture of an air parcel and insures its transfer at a constant pressure towards an on-line analyzer. It is composed of two mechanical syringes moved by electric actuators with an alternated functioning to supply continuously the analyzer. Three solenoid valves are installed on each reservoir to drive the sample flow depending on the cycle. A micro controller chip is used to give the rhythm of the whole system with millisecond accuracy. This sampling system has been built in chemically inert materials to avoid sample contamination or destruction; this makes MEDEE fully compatible with reactive species. MEDEE has been tested and validated on ground and aboard an aircraft, during two field campaigns. It was coupled to a fast isoprene sensor for BVOC flux measurements during two field campaigns in summers 2010 and 2011 above a downy oak forest. A Neural Network (NN) approach has been used to derive a biogenic VOC emission algorithm from these canopy level measured fluxes and concurrent environmental parameters. Isoprene emission modeling has been validated for the observed environmental conditions. In the future, such emission parameterization will be implemented in a coupled chemistry-dynamics model to study the impact of biogenic VOC emissions on air quality
Bernard, François. "Etude du devenir atmosphérique de composés organiques volatils biogéniques : réactions avec OH, O3 et NO2". Phd thesis, Université d'Orléans, 2009. http://tel.archives-ouvertes.fr/tel-00517365.
Texto completoGonzaga, Gomez Lais. "Échange de composés volatils biogéniques entre l'atmosphère et les cultures de blé, maïs et colza". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS319.
Texto completoVolatile Organic Compounds (VOC) play a key role in atmospheric chemistry influencing climate and air quality. Vegetation is the main source of VOC, accounting for 90% of biogenic emissions (BVOC). Agricultural crops in Europe are estimated to contribute 27% of total BVOC emissions but remain poorly studied. In this work, we study the exchange of BVOC by wheat, rapeseed and maize, the main agricultural species in France in terms of cultivated area. The fluxes were measured in the field at the plant level with dynamic automated chambers coupled to a PTR-Qi-Tof-MS spectrometer. Fluxes of up to 997 compounds could be measured with this highly sensitive instrument. Chapter 1 presents a review of BVOC emission mechanisms, flux measurement methods, experimental results on BVOC exchanges in agricultural systems, and mathematical models of emissions. Chapter 2 describes the measurement site and the experimental setup. Chapter 3 presents BVOC fluxes measured during one week for each species. Emissions were dominated by methanol (55-85% of total emissions) followed by acetone and acetaldehyde. The 10 most emitted compounds excluding methanol accounted for more than 50% of total emissions and the 100 most emitted compounds accounted for more than 90%. The measured fluxes showed little intra-species variation but large inter-species variations with total net fluxes of 0.11±0.02 µg_BVOC g_DW^(-1) h^(-1) for maize, 1.5±0.7 µg_COVB g_MS^(-1) h^(-1) for wheat, and 9.1±2.4 µg_COVB g_MS^(-1) h^(-1) for rapeseed. Finally, standard emission factors for isoprene and monoterpenes were evaluated for each species, constituting the first known estimates for rapeseed. Chapter 4 examines the influence of developmental stages, and particularly of senescence, on BVOC emissions from wheat. We report a doubling of total emissions during senescence compared to maturation, with, in particular, an increase in the contribution of acetaldehyde (1.6% of total emissions during maturation and 9.7% during senescence) and acetic acid (0.7% during maturation and 2.7% during senescence). In Chapter 5 the main parameters of the MEGAN 2.1 model are estimated for the three species and the fluxes of six main compounds measured for rapeseed at the plant level by the dynamic chambers are compared with measurements by Eddy Covariance at the ecosystem level in order to evaluate the representativeness of chamber measurement. This work shows the heterogeneity of BVOC exchanges by agricultural plants and the data generated should contribute to the improvement of emission models
Dutaur, Laure. "Caractérisation des sources biogéniques des composés organiques volatils contribuant à la pollution photochimique dans le bassin méditerranéen". Toulouse, INPT, 1996. http://www.theses.fr/1996INPT024G.
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