Tesi sul tema "Matière organique particulaire – Combustion"
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Pietraccini, Matteo. "Mechanisms involved in the fast combustion of organic powders : application to dust explosions". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0290.
The industry's risk associated with dust explosions is commonly accepted as high by the scientific community, and it must be reduced to a minimum to improve working conditions. However, the lack of knowledge of the phenomena involved, combined with a scarce general awareness of numerous industrial realities, transforms the dust explosions into profoundly dangerous accidental scenarios. Powder manipulation is a fundamental brick of contemporary industrial reality, and no shortcut can be chosen to bypass it. For this reason, dust explosions are merged with a large variety of processes and need to be studied and well understood. In the second half of the XX century, an energetic transition destabilised the fossil energy sector, painting it greener and greener. As a result, lignocellulosic biomass was and still is one of the most popular worldwide bioenergy sources. Moreover, its enormous versatility and significant technological progress made it possible to start the competition with fossil fuels. The development of the bioenergy sector and the dust explosion are the two actors of this work. Therefore, organic dust explosions were chosen as a study subject, comprehended and characterised to contribute to the scientific knowledge of these phenomena. They can be treated as transient, turbulent, particle-laden systems, which makes them complex and far from being straightforward to understand. Several physicochemical phenomena are involved in the global one. First, a dispersion step is unavoidable in a dust explosion. In this phase, the powder's features may change and strongly impact its behaviour. Second, particle-to-particle interactions are responsible for agglomeration and deagglomeration in the dust cloud thus formed. Again, it can modify the system's characteristics, influencing its thermal comportment. Cohesive forces may lead to strong aggregation of the particles, which has notably a mark on the particle heating time scale. A large selection of organic powders was tested, and their tendency to agglomerate in a dust cloud was quantified. Third, a fundamental brick of organic powder explosions is the pyrolysis step, which can be seen as a devolatilisation responsible for creating a flammable atmosphere within the dust cloud. It is often the rate-limiting step of the global process, and it needs thus to be well analysed. Then, the potential synergy between the gaseous and solid phases can lead to a reactive system different from the sum of the two. Some new phenomena might be generated from this. For instance, radiative heat transfers are major players in the flame propagation phase, strongly dependent on the dust concentration and its optical properties. To conclude, willing to develop an original method to determine the laminar flame speed of organic powders, three apparatuses were selected and compared. The benefits and drawbacks of each were listed and used as choosing criteria
Savoye, Nicolas. "Origine et transfert de la matière organique particulaire dans les écosystèmes littoraux macrotidaux". Brest, 2001. http://www.theses.fr/2001BRES2034.
Dubois, Anne-Sophie. "Composition et transfert trophique de la matière organique particulaire dans le Bassin d’Arcachon". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14515/document.
Abstract
Zhang, Qijie. "Simulation de la matière particulaire dans la région parisienne, en particulier de l'aérosol organique". Paris 7, 2012. http://www.theses.fr/2012PA077206.
Human activities in large agglomerations ("megacities") cause large pollutant emissions, with negative effects on air quality and human health at a local and regional level. Fine particulate matter (PM) is one of the greatest concerns for health. Organic aerosol makes up a large part of fine PM, but there are still large gaps in the knowledge on its formation pathways and there is considerable uncertainty in its 3D modeling. In this thesis, PM₂. ₅ simulations with the regional chemistry-transport model CHIMERE were first evaluated with measurement date collected in Paris in springtime, 2007. The model results show good performance of simulating occurrence of peaks, especially for inorganic aerosols which mainly originate from long range transport from Northeastern and Central Europe. Modeled primary organic aerosol (POA) is overestimated when considered as non-volatile by a factor of two, while secondary organic aerosol (SOA) is underestimated by a factor of more than two. In order to improve the model performance of organic aerosol simulation, the volatility basis set approach which formalizes new knowledge on POA volatility and on SOA chemical aging is implemented into CHIMERE. Model simulations are evaluated with ground based and airborne observations obtained during two intensive field campaigns performed in the Paris agglomeration in summer 2009 and winter 2009/2010 in the frame of the European MEGAPOLI project. The simulation for organic aerosol is improved when taking into account POA volatility and multistep oxidation of semivolatile VOC during the summer campaign. Advection of continental air masses to the Paris agglomeration with enhanced SOA levels either from anthropogenic or biogenic origin, is well restituted by the model. SOA build-up in the plume is overestimated by a factor of two when normalized to photochemical ozone production, but this factor is within the uncertainty of the VBS approach. During the winter campaign, SOA formation is still underestimated. These results clearly represent progress in the modeling of organic aerosol in and around a large urban agglomeration. The model was used to estimate sources contributing for summer 2009 to organic aerosol in the agglomeration and in the plume. Within the agglomeration, advection of biogenic, anthropogenic and background SOA from outside was dominant, while locally emitted POA accounts to about a quarter of total OA. In the plume, anthropogenic SOA formation, and to some extent also SOA formation from aged POA becomes dominant. These results are in broad agreement with source apportionment studies from observations
Cotrim, Da Cunha Leticia. "Caractérisation de la matière organique particulaire et dissoute dans un fleuve méditerranéen, le Tech". Perpignan, 2000. http://www.theses.fr/2000PERP0376.
Characterisation of organic matter in small rivers and streams is important to qualify the impact of human activity and identify the main biogeochemical processes in the drainage basin. Small drainage basin areas enable a better approach to characterise and qualify the riverine organic matter
Panagiotopoulos, Christos. "Distribution moléculaire et état de dégradation des sucres combinés dans la matière organique particulaire". Aix-Marseille 2, 2002. http://www.theses.fr/2002AIX22079.
Nouara, Amel. "Développement d'outils analytiques pour la quantification et l'étude isotopique des composés organiques issus des feux de biomasse dans l'environnement". Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0329.
Biomass burning (BB) pollution is a major concern for public health and climate change. In order to improve our understanding on the origin and fate of compounds related to BB in the environment, we have developed new analytical methods (isotopic and chromatographic methods) allowing the detection of anhydrosugars as well as a broader panel of sugars in natural ecosystems. The first developed method allowed to perform for the first time compound specific isotopic measurements of individual sugars by EA-IRMS (δ13C) and/or EA-AixMICADAS (∆14C) after purification by HPLC-RI. Our results showed the presence of anhydrosugars in the marine particulate organic matter (POM) sample with a terrestrial isotopic signature (δ13C <26.2‰), indicating an external terrestrial input to marine environment. In addition, the radiocarbon signature of levoglucosan (∆14C = 33‰) from total suspended atmospheric particles (TSP) sample indicates a modern age, suggesting its recent synthesis in the environment. The HPAEC-PAD chromatography is the second method developed in the frame of this study and provided a full analysis of 17-simple sugars. This method allowed for the first time the quantification of anhydrosucres in the marine POM and high molecular weight dissolved organic matter (HMWDOM), that represent 2% and 3% of total sugars detected, respectively. In a complementary study, the emissions from BB have been also studied in aerosols from the Mediterranean Sea by monitoring the annual variations of anhydrosugars. The results of this study highlight the important contribution of BB emissions (up to 13%) to organic carbon pool in the PM10 particles arriving in the Mediterranean basin
Galeron, Marie-Aimée. "Degradation of terrestrial particulate organic matter discharged by rivers in the Mediterranean Sea : processes, interactions and global impacts". Electronic Thesis or Diss., Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4120.
The degradation of terrestrial organic matter has puzzled scientists for decades. Once thought to be refractory to further degradation once at sea, it was finally shown that very little trace of a terrestrial signature was found in coastal sediments.In order to fully apprehend these degradation processes, it is crucial that we look at their global occurrence, and try to determine if the same pattern is observed in temperate areas.Using a set of lipid tracers especially designed to help us trace both the origin of the particulate organic matter and the degradative processes it had undergone, all samples collected in the Rhône river were analyzed and compared with Arctic and Tropical samples. The roles of photo- and autoxidation during riverine transport were clearly evidenced: photo-oxidation was the main degradation driver in the Mackenzie River, while autoxidation had a clearly more important role in the Amazon River. In the Rhône River, both processes had a moderate impact on riverine suspended particulate matter (SPM), but yet, an intense autoxidation was evidence in the Rhône plume, just as it was evidenced in the Mackenzie plume.Further analyses on the collected samples allowed us to formulate – and confirm – a new hypothesis. A lipoxygenase enzymatic activity was observed and quantified in all the samples studied, at various degrees depending of local conditions. This activity was shown to be induced by the variable amounts of autoxidation- or photo-oxidation deriving hydroperoxides present in the suspended particulate matter, highest at high and low latitudes
Liénart, Camilla. "La matière organique particulaire dans les systèmes côtiers : composition, dynamique et forçages à l'échelle multi-systémique". Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0255/document.
Pelagic coastal systems are characterized by multiple inputs of particulate organic matter (POM) from autochthonous (phytoplankton) and allochthonous (continental, benthic) origin whose spatial and temporal variability can be high. The aims of my PhD were to 1) quantify POM composition in pelagic coastal systems, 2) determine the forcings to its spatio-temporal dynamics and 3) investigate the link between bacteria and POM composition. This study was conducted on twelve systems (estuary, lagoon, bays, rias, littoral) distributed over the three maritime facades of France by combining the use of elemental and isotopic ratios (composition), fatty acids (POM-bacteria link) and multivariate analysis (forcings).At multi-systems and/or intra-system scale, two main gradients are observed:- an inshore (higher continental and benthic contribution) - offshore gradient (phytoplanktonic POM) mainly related to hydrodynamics and sedimentary hydrodynamics (river flow, resuspension of benthic material) and to the proximity to allochthonous sources- a South (POM related to diazotrophy) – North (absence of this POM) gradient, associated to the trophic status (oligo vs meso/eutrophy) of the studied systems.The seasonality of spatio-temporal dynamics of POM composition is highly variable depending on the station. It is in general higher near the coast and lower offshore and upstream in the studied estuary. This dynamic is also strongly associated to sedimentary hydrodynamics.Finally, this study highlight that bacterial biomass is mainly associated to continental and benthic POM
Navel, Simon. "Rôle des échanges à l’interface eau-sédiment et de l’activité des invertébrés sur la dégradation de la matière organique particulaire dans le milieu hyporhéique". Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10291.
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Galeron, Marie-Aimée. "Degradation of terrestrial particulate organic matter discharged by rivers in the Mediterranean Sea : processes, interactions and global impacts". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4120/document.
The degradation of terrestrial organic matter has puzzled scientists for decades. Once thought to be refractory to further degradation once at sea, it was finally shown that very little trace of a terrestrial signature was found in coastal sediments.In order to fully apprehend these degradation processes, it is crucial that we look at their global occurrence, and try to determine if the same pattern is observed in temperate areas.Using a set of lipid tracers especially designed to help us trace both the origin of the particulate organic matter and the degradative processes it had undergone, all samples collected in the Rhône river were analyzed and compared with Arctic and Tropical samples. The roles of photo- and autoxidation during riverine transport were clearly evidenced: photo-oxidation was the main degradation driver in the Mackenzie River, while autoxidation had a clearly more important role in the Amazon River. In the Rhône River, both processes had a moderate impact on riverine suspended particulate matter (SPM), but yet, an intense autoxidation was evidence in the Rhône plume, just as it was evidenced in the Mackenzie plume.Further analyses on the collected samples allowed us to formulate – and confirm – a new hypothesis. A lipoxygenase enzymatic activity was observed and quantified in all the samples studied, at various degrees depending of local conditions. This activity was shown to be induced by the variable amounts of autoxidation- or photo-oxidation deriving hydroperoxides present in the suspended particulate matter, highest at high and low latitudes
Corti, Roland. "Assèchement des cours d'eau : effets sur les communautés d'invertébrés et la dynamique de la matière organique particulaire". Phd thesis, Université Claude Bernard - Lyon I, 2013. http://tel.archives-ouvertes.fr/tel-00828092.
Companio, Anne-Marie. "Etude de l'origine de la matière organique particulaire : chromatographie HPLC des oses constitutifs de la fraction glucidique". Aix-Marseille 2, 1990. http://www.theses.fr/1990AIX22026.
Corti, Roland. "Assèchement des cours d'eaux : effets sur les communautés d'invertébrés et la dynamique de la matière organique particulaire". Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10048/document.
Aquatic-terrestrial transitions play a major role in the functioning of ecosystems. In rivers that periodically cease to flow, these transitions move laterally in riparian zones and longitudinally along dry riverbeds. The objective of this thesis was to determine in drying rivers the effects of aquatic-terrestrial transitions on terrestrial invertebrate communities and on particulate organic matter dynamic, a key ecological process for ecosystem functioning. The results show that riparian communities are poorly dependent on aquatic resources from the rivers but are essential to invertebrate diversity in dry riverbeds. Organic matter has a pulsed dynamic in drying rivers with transport and processing stages limited to aquatic conditions, potentially influencing nutrient availability in river networks
Euzenat, Charly. "Contributions à la simulation de l’enlèvement de matière par abrasion". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST059.
The production of mechanical parts with high added value involves significant machining times and sometimes requires the functional surfaces to be finished by abrasion in order to achieve the required specifications. The correct definition of the parameters of the manufacturing process plays an important role in obtaining the final surface finish on the parts produced. In this context, the control of involved parameters is still carried out empirically.The thesis focuses on the polishing of functional surfaces and in particular on the prediction and realistic simulation of the effects of abrasion processes on surface topography. The proposed work contributes to the study of new simulation methods for abrasion. More specifically, the scientific challenge of this work is to create a breakthrough with conventional simulations, using meshless methods, and to evaluate their performance in this context. The simulation results obtained in indentation and scratching tests have been compared to experimental results and are in agreement. However, the simulation times are too long to envisage a complete abrasion simulation involving the passage of hundreds of abrasive grains.To overcome these difficulties, the development of an abrasion model based on the implicit representation of surfaces was carried out. The abrasion process is modelled using this surface representation formalism. A complete manufacturing process from machining to abrasion is successfully simulated and experimentally validated. The models studied could be a possible foundation for the development of an industrial simulation framework. The contribution of simulations to the automation of abrasion operations and the optimization of manufacturing processes could help to increase the productivity and quality of mechanical parts
Kerherve, Philippe. "Les monosaccharides marqueurs de l'origine et de l'état de dégradation de la matière organique particulaire en milieu marin". Perpignan, 1996. http://www.theses.fr/1996PERP0247.
Personeni, Emmanuelle. "Dynamique du carbone et de l'azote lors de la décomposition in situ de litières racinaires de graminées prairiales". Paris 6, 2004. http://www.theses.fr/2004PA066263.
Thibault, Alexandre. "Dynamique de la matière organique dans la Seine : approche globale et moléculaire". Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS284.
Estuaries are important ecosystems from environmental and economical point of views and are the place of numerous transformations of organic matter (OM). The dynamics of OM in estuarine systems is complex and was only rarely investigated at the structural or molecular level. The aim of this study was to constrain the sources and fate of the OM in the Seine Estuary. The spatiotemporal dynamics of the OM along the estuary was investigated by comparing the bulk (elemental and isotopic composition), structural (solid state 13C nuclear magnetic resonance) and molecular (lipids and thermochemolysis) features of the different pools of OM – dissolved OM (DOM), particulate OM (POM) and sediment OM collected during five sampling campaigns. All analyses show that each compartment has different chemical properties: DOM is enriched in degraded aquatic OM, while POM and sediment OM are enriched in terrigenous OM. The maximum turbidity zone has an impact on OM quality with a high bacterial activity leading to the degradation of terrigenous OM and a higher proportion of aquatic OM. This study shows that sediment OM does not reflect the composition of the POM in the water column and is enriched in terrigenous OM. Moreover, when the sediment is aging, the proportion of terrigenous OM is increasing
Kania, Manon. "Caractérisation des dépôts de surface des filtres plantés de roseaux à écoulement vertical. Rôle et évolution de la matière organique particulaire". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI045/document.
The percolation of unsettled wastewater in French Vertical Flow Constructed Wetlands (VFCWs) causes the formation of a sludge layer at the surface of the first stage filter due to the retention of sludge deposits. Although the growth of this layer over the years of operation is a potential source of clogging risks, it also largely contributes in the performance of the system, depending on its properties. In order to better understand these phenomena, surface sludge deposits samples taken from 14 VFCW sewage treatment plants were collected and analyzed. Results showed that the structure and composition of the sludge deposits from treatment plants with more than three years of operation time were remarkably similar, characterized by the presence of stable and complex organic compounds and a low reactivity and biodegradability of the particulate organic matter. Deposits from treatment plants with less than one year of operation time were composed of more reactive and less mature organic matter. The particulate organic matter of the inflow wastewater was also shown to undergo modifications within the treatment chain of the vertical flow constructed wetland. The implementation of a biological trickling filter as an additional treatment prior to the filter stages was found to induce the transformation of soluble and particulate organic matter through mineralization and hydrolysis, and to contribute to humification probably by the detachment of biofilm fragments. The injection of ferric chloride used to precipitate phosphates was found to promote aggregation within the sludge deposits. Finally, the role of the sludge layer in the retention of a selection of organic and metallic pollutants in VFCW systems has been evaluated by analyzing sludge deposits samples. Detergents were found at higher concentrations than PCPP. The potential release of the sorbed contaminants was studied using leaching tests as a function of pH. Results showed that the release of some trace metals (mostly copper) was governed by the leaching behavior of organic matter
Houri-Davignon, Cécile. "Contribution à l'étude des relations entre les apports de matière organique particulaire à l'interface eau-sédimemt et l'activité minéralisatrice du micro-méiobenthos". Bordeaux 1, 1990. http://www.theses.fr/1990BOR10578.
Lin, Rong Gen. "Etude du potentiel de dégradation de la matière organique particulaire au passage eau douce-eau salée : cas de l'estuaire de la Gironde". Bordeaux 1, 1988. http://www.theses.fr/1988BOR10561.
Fumenia, Alain. "Dynamique spatiale et temporelle de la biomasse organique particulaire synthétisée dans une région océanique fortement influencée par la fixation de diazote atmosphérique (campagne océanographique OUTPACE dans le Pacifique tropical sud-ouest)". Electronic Thesis or Diss., Aix-Marseille, 2020. http://www.theses.fr/2020AIXM0173.
In the Western Tropical South Pacific (WTSP), the dynamics of the particulate organic matter (POM) derives from two distinct planktonic systems in this oligotrophic region.In the mixed layer, the POM presents an excess of nitrogen with respect to the Redfield stoichiometry, with a N:P ratio of 19 ± 2. In this study, the high rates of biological dinitrogen fixation (N2) measured in this region has been pointed as the main source of new nitrogen, supporting the N-enriched POM production.Statistically significant relationships between bbp and PON (and POP) concentrations were established (R² = 0.87 and 0.91, respectively), allowing to define, for the first time, optical proxies (PONopt and POPopt) of particulate organic biomass. During the stratified periods of the studied period (3 years), significant increases in PONopt are observed only in the Melanesian Archipelago. These recurrent increases of PON concentrations in this area can only be supported by nitrogen input via the N2 fixation process.In the vicinity of the euphotic depth (Z01), a Subsurface Maximum of Chlorophyll-a (Chla) Layer (SCML) is permanently associated with a maximum of particulate organic biomass. By using O2 data collected by the float FA on a seasonal time scale, the calculated Net Community Production (0.08 ± 0.01 mmol m-3 d-1 on average) exhibited a low but positive value within the SCML, in the dimly lit layers between Z01 and the depth in which the measured PAR is reduced to 0.1% of its surface value (Z001)
Njomgang, Rosaline. "Modélisation des interactions de la matière organique des sols avec les métaux : Etude des systèmes Fer (III) - acides Dihydroxybenzoïques et Fer (III) - Polycondensats". Reims, 1987. http://www.theses.fr/1987REIMS007.
Bee-Debras, Agnès. "Etude des systèmes cuivre (II) - acides dihydroxybenzoïques et cuivre (II) - polycondensats : modélisation des interactions de la matière organique des sols avec les métaux oligo-éléments". Reims, 1987. http://www.theses.fr/1987REIMS004.
Darnaude, Audrey. "Apports fluviaux en zone côtière et réseaux trophiques marins benthiques : Transfert de matière organique particulaire terrigène jusqu'aux poissons plats au large du Rh^one". Aix-Marseille 2, 2003. http://www.theses.fr/2003AIX22025.
Villeneuve, Jean-Pierre. "Géochimie des composés organochlores dans l'environnement marin". Paris 6, 1986. http://www.theses.fr/1986PA066153.
Pineault, Simon. "Signature isotopique du carbone et de l'azote dans la matière organique particulaire de la glace de mer en Arctique : facteurs de contrôle et applications écologiques". Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28049/28049.pdf.
Grimm, Christian. "Charge particulaire fluviale : effet sur productivité primaire et implications sur le cycle global du carbone organique". Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30322/document.
The supply of riverine particulate material (RPM) to natural waters plays a vital role in the global cycle of the elements and is considered to influence the organic carbon cycle in two ways. First, RPM comprise a vast source of nutrients which can increase primary production in the oceans. For example, the global RPM flux of nutrients such as Si, P and Fe exceeds its corresponding dissolved flux by factors of 50, 100 and 350. Second, the supply of RPM to the oceans is a major control of organic matter (Corg) burial, an essential process in the long term CO2 drawdown via the organic pathway. To explore the link between RPM supply and primary production in natural waters, a series of microcosm growth experiments was performed with two common primary producing microbes, the freshwater cyanobacteria Synechococcus sp. and the marine diatom Thalassiosira weissflogii. Experiments were performed in the presence and absence of different RPM at different initial nutrient levels. Results demonstrate that RPM significantly increase bacterial biomass growth as a function of RPM concentration. Notably, in experiments conducted with the freshwater cyanobacteria Synechococcus sp., the presence of RPM 1) triggered bacterial growth in otherwise unfavorable conditions, 2) increased total biomass concentration, and 3) induced steady bacterial growth even after consumption of the initial nutrients. The positive effect of RPM on the growth of the marine diatom Thalassiosira weissflogii was most obvious in nutrient free experiments where cultures grew linearly with time in the presence of RPM, whereas these cultures died in RPM free controls. Furthermore, SEM investigations showed direct physical contact between microbes or microbially excreted organic substances and the particulates. In accord with reports in the literature, we suggest that microbes may acquire nutrients directly from the rock, which would again enhance the potential of RPM as source of limiting nutrients. The direct physical contact also suggests an increase in the burial efficiency of Corg through either 1) increasing Corg content absorbed on mineral surfaces, 2) increasing agglomeration and marine snow formation of organic and inorganic particles or 3) increasing organic matter settling velocities through mineral ballasting. The direct attachment of microbes on mineral surfaces was also observed in natural samples obtained from a field study at the Icelandic South coast. The positive effect of RPM on microbial growth and its effect on Corg burial are complimentary. Agglomeration is a function of suspended particle concentration, organic or inorganic. An elevated biomass concentration induced by the presence of RPM results in a high total suspended matter concentration, thus increasing the particle agglomeration rate. Taken together, this study provides experimental evidence for the importance of RPM in the organic C-cycle through its positive impact on primary production. Furthermore, it compiles evidence that particulates may facilitate organic matter burial through direct attachment of microbes on sediment surfaces or the formation of fast settling mineral/microbe agglomerations. Complimentary studies were performed to assess the quality of carbon isotope compositions to preserve estimates of Corg burial rates over geological time. Variations in the degree of primary production and Corg burial during Earths' history are recorded in the C-isotopic signature of marine carbonates. The use of carbon isotopic signatures in carbonates to reconstruct past environmental conditions, however, requires that these signatures are preserved over vast timescales. Experimental results demonstrate, that the carbon isotopic composition of calcite continuously evolves towards mineral-fluid isotopic equilibrium. This observation suggests that calcite C-isotopic compositions might change noticeably if the calcite were continuously in isotopic disequilibria with its co-existing fluid
Brugeaille, Michèle. "Qualification et quantification des biomasses dans la matière organique particulaire au sein de différents écosystèmes planctoniques et benthiques par mesure de l'activité des systèmes transporteurs d'électrons". Bordeaux 1, 1988. http://www.theses.fr/1988BOR10609.
El, Azzi Désirée. "Transfert de polluants organiques et inorganiques dans les hydrosystèmes en période de crue : interactions avec les matières en suspension et la matière organique". Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1885/.
The mechanisms involved in the transfer of organic and inorganic pollutants to streams in agricultural watersheds are largely studied. However, few studies concern storm events responsible for the transportation of large quantities of pollutants to the outlet and they rarely take into account a multi-pollution dynamic. A heavy monitoring was therefore conducted during the storm event of May 2010 at the outlet of the Save river (1110 Km2) in the south west of France. The majority of pollutants and their controlling factors (dissolved and particulate organic carbon (DOC and POC) and suspended particulate matter (SPM)) are more concentrated during storm flow than base flow and their concentration increases with stream water discharge. Pollutants are also more concentrated during these events. Hydrograph separations showed that pollutants are primarily transported in the surface runoff adsorbed onto SPM when they have a low solubility (hydrophobic) and in the subsurface runoff linked to DOC when they are soluble. Different kinds of chemical bonds can exist between pollutants and the different SPM fractions (organic matter, clay and oxides). In order to investigate these bonds, we studied in particular Cu dynamic in the small wine growing catchment of Baillaury (18. 2 Km2), close to Banyuls sur Mer (Eastern Pyrénées), within the framework of the CRUMED project (EC2CO-INSU/CNRS). This Mediterranean type-flow regime stream is mostly cultivated with vineyards and has been treated with Bordeaux mixture for centuries. Moderate to significant enrichments of soils at different depth, river bottom sediments and suspended matters were revealed. Anthropogenic contribution to this enrichment is estimated between 50 and 85 % in all samples showing that the Cu present in the river is mainly due to agricultural practices. Sequential chemical extractions SCE) allow us to determine Cu distribution in the different residual and non-residual fractions (exchangeable, acido-soluble, Mn and Fe oxides, organic matter), showing that anthropogenic Cu is mainly adsorbed onto iron oxides. The isotopic Cu composition measured in each fraction shows that Cu transported in solution and adsorbed onto organic matter seems to be associated without any fractioning. Gross samples have signatures similar to the bedrock and so studying the detailed SCE fractions is essential. Combining SCE and isotopic signatures is a powerful tool to understand Cu distribution and transfer in the environment. However, in the environment, a pollutant is rarely alone and other pollutants can influence its fate. Therefore, in order to investigate the influence of the presence of other pollutants on a pollutant's adsorption, organic (two pesticides: alachlore and aclonifen) and inorganic (two heavy metals: Cu and Cd) pollutants adsorption on natural SPM (collected in the Save river during the flood) were studied. Most studied pollutants were influenced by the presence of one or more other pollutants in the water, trace metals to a lesser extent than pesticides. The order of presence in the water also influences the adsorption rate of the pollutant onto SPM. The mutual influence can be due to competition for the same adsorption sites or to the creation of complexes between pollutants. These complexes can modify the adsorption capacities of each pollutant. These original results obtained in this work open up new perspectives and requests
Veyssy, Eric. "Transferts de matières organiques des bassins versants aux estuaires de la Gironde et de l'Adour (Sud-Ouest de la France)". Bordeaux 1, 1998. http://www.theses.fr/1998BOR10529.
Mirivel, Giovanni. "Développement de méthodes d'analyse de composés organiques dans les particules fines et étude de leur vieillissement en milieu contrôlé". Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10103/document.
This thesis – dealing with the chemical characterization of organic matter in fine atmospheric particles – consisted of the two following objectives: (i) the development of analytical methods to identify and quantify some organic compounds: long-chain mono- and dialkanoic acids, polycyclic aromatic hydrocarbons (PAHs) and their nitrated and oxygenated derivatives;(ii) the study of possible sampling artefacts while collecting particulate PAHs on filters under controlled conditions.The analyses were carried out by liquid chromatography coupled to a UV detector and a fluorimeter for PAHs, and a time-of-flight mass spectrometer for the other species. Pressurized liquid extraction methods were optimized using experimental design. The proposed methods were validated on complex matrices (standard reference materials and/or real samples). Concentration levels could be monitored for particles collected in an urban background site in Douai and seasonal trends consistent with literature data have been observed.Sampling artefacts linked to desorption and reactivity towards atmospheric pollutants (O3, NO2) for particulate PAHs present in real samples have been investigated using an experimental device to simulate filter sampling. The magnitude and the variability of these artefacts have been measured as a function of environmental conditions (temperature, relative humidity) and pollutant concentrations
Zhang, Zhe-Xuan. "Dynamics of dissolved and particulate organic matter along the land-sea continuum of the Seine Estuary (France)". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS268.
Estuaries are critical zones from ecological, economical, and biogeochemical points of view and play an important role in regulating Dissolved Organic Matter (DOM) and Particulate Organic Matter (POM). To date, estuarine DOM and POM were mostly studied separately, hampering our understanding of their overall dynamics and associated estuarine biogeochemical functioning. The aim of this PhD thesis was to determine the sources, transformations and fate of estuarine POM and DOM in the Seine Estuary (North Western France). To this aim, the spatiotemporal variations of POM and DOM characteristics were determined using water samples (n=383) collected along the land-sea continuum of this estuary during 24 sampling campaigns from June 2019 to November 2022. First, the POM dynamics was investigated at the bulk and molecular scales, through elemental and isotopic analyses as well as lipid biomarkers. A novel molecular proxy (Riverine IndeX, RIX) based on bacterial membrane lipids was developed to trace the riverine POM inputs into estuaries. POM is a mixture of molecules from different sources (terrestrial, algal/microbial, anthropogenic), which showed distinct dynamics along the Seine estuary, highlighting that the complex transformations to which POM is subjected is closely dependent on its composition. Furthermore, DOM properties were investigated by optical techniques (UV–Visible absorbance and Excitation-Emission Matrix fluorescence spectroscopy) coupled with unsupervised and supervised machine learning. This led to the development of a model disentangling the complexity of DOM and capturing specific characteristics of the latter in different zones of the Seine Estuary, with varying levels of molecular weight, aromaticity, and autochthonous material. Such DOM signatures are not effectively identified using traditional approaches. Finally, this PhD work shows that DOM and POM dynamics are decoupled along the Seine land-sea continuum and that the estuary controls the transport and transformation of various constituents of organic matter, which are linked, in particular, to hydroclimatic conditions and land use
Modéran, Julien. "Estuaire de la Charente : structure de communauté et écologie trophique du zooplancton, approche écosystémique de la contamination métallique". Phd thesis, Université de La Rochelle, 2010. http://tel.archives-ouvertes.fr/tel-00541019.
Wolters, Cédric. "Caractérisation moléculaire d’échantillons organiques complexes par spectrométrie de masse et chromatographie en phase liquide". Thesis, Université Grenoble Alpes, 2021. http://www.theses.fr/2021GRALU009.
How to analyse a complex organic sample? This general question seems simple at first glance but requires a closer look at the notion of complexity to be able to understand and justify the means used to characterise it. In planetology, and more widely in astrophysics, all the observations and observables indicate that the matter that makes up extraterrestrial objects is composed of a mixture of various molecules, and this mixture is more or less diverse and dense depending on the object. Observations and models are routinely done to try to understand these objects and to constrain their evolutionary processes, or to try to investigate their origin.Characterising the molecular complexity of such objects requires state-of-the-art instruments, which are difficult to adapt to space industry constraints in order to be placed on a probe, and this requires that the object under study can be sampled. However, most objects of interest cannot be reached in a reasonable time. Therefore, another way to study these objects is needed: laboratory astrophysics. Many experiments attempt to simulate the objects and environments in which they evolve and analyse the evolution of matter subjected to these constraints. Part of the challenges of these experiments lies in the chemical characterisation of the samples, and more particularly in their molecular characterisation.As part of this thesis, we proposed to use high-resolution mass spectrometry (HRMS) and high-performance liquid chromatography (HPLC) to characterise complex organic samples. To do so, the entire analytical chain was studied, from the data acquisition to its use. Thus, we proposed an optimisation of the data acquisition in Orbitrap, as well as the systematic processing of the data resulting from the analysis done by ESI-HRMS as well as for the analysis done by LDI-ICR. Chromatography coupled with mass spectrometry is a powerful tool for accessing the molecular structure of samples and requires developing methods that are suited to the samples analysed. Therefore we offered two HPLC methods for sample analysis, which have been developed and validated for the analysis of complex samples. However, no currently available commercial software allowed for the unsupervised analysis of such samples. Software to allow the processing of this data has now been developed and allows the molecular diversity of samples to be revealed without supervision. The identification of the detected molecules is not an easy process since it then requires having all the possible isomers for each molecule detected as standards for reference. To reduce the number of possibilities, a tool for predicting retention times was proposed. This was based on knowledge of the physico-chemical properties of known compounds to predict their theoretical retention time on the methods used.Lastly, this work presents the application of all the developments carried out during these three years on a set of samples of synthetic atmospheric aerosol analogues modelling exoplanets of the super-Earth and mini-Neptunes type. From the analysis of their soluble matter to the comparison between soluble, insoluble, and total phase, analysis by mass spectrometry indicates a great diversity and important differences between samples. This indicates processes of formation and evolution related to the composition of the reactive mixture. Finally, chromatographic analysis of one of these samples indicates multiple isomers, some of which may be labelled as biological molecules, potentially involved in the process of the origin of life
Mablouké, Cécile. "Étude des ratios isotopiques du carbone et de l'azote de la matière organique particulaire et des muscles de poissons d'intérêt commercial d'écosystèmes côtiers tropicaux du sud-ouest de l'océan Indien : contribution à l'étude de leur fonctionnement". Thesis, La Réunion, 2013. http://www.theses.fr/2013LARE0017/document.
The aim of this thesis was to study the feeding habits of coastal fish species of commercial interest andto use stable isotopes of carbon (δ13C) and nitrogen (δ15N) to investigate the trophic niches of fish and their use of coastal habitats in the south-west Indian Ocean. In the Bay of La Possession, the species among the most abundant around the artificial reefs immersed in 2003 (Luljanus kasmira, Priacanthus hamrur and Selar crumenophthalmus) feed essentially on pelagic prey and partition their trophic niche to limit interspecific competition. There was also a positive correlation between fish size and muscle δ15N values due to fish larvae contributing more to the diet of fish with age. The stable isotopie composition of the particulate organic matter (POM) was measured at the microscale (< 10 km) in the Bay of La Possession, the mesoscale (10's of km) around Reunion Island and, for the fish muscles, at the macroscale 100’s of km) along the Mascarene plateau and the Mozambique channel. At microscale, POM δ15N values do not show any spatial variability; at mesoscale, POM is 15N-enriched in the south-west of Reunion Island; at macroscale, fish muscles are gradually 15N-enriched towards the north. At microscale, POM shows a 13C-enrichment on the shallowest station; at mesoscale, stations on the east coast of the island are 13C-enriched compared to the west; at macroscale, POMδ13C values are not significantly correlated with latitude. Thus, the stable isotopes of carbon do not seem to be appropriate for the study of fish coastal habitat use at the meso- and macroscale, and the stable isotopes of nitrogen represent a better indicator of fish habitat use at the macroscale
Marchand, Nicolas. "Etude de la composante organique de l'aérosol atmosphérique : cas de deux vallées alpines (Chamonix et Maurienne) et développement analytique". Phd thesis, Chambéry, 2003. http://tel.archives-ouvertes.fr/tel-00003533.
Dans le cadre du programme PO.V.A. (POllution des Vallées Alpines), articulé autour de la réouverture du tunnel sous le Mont Blanc et dont les principaux objectifs sont de mieux appréhender les phénomènes de pollution atmosphérique et les mécanismes dispersifs propres aux systèmes montagneux, des aérosols ont été collectés dans les vallées de Chamonix et de Maurienne au cours de deux campagnes intensives de mesures. Elles se sont déroulées au cours de l'été 2000 et de l'hiver 2001.
Après la présentation des problématiques (chapitre I) et des méthodes utilisées (chapitre II), les résultats de deux types d'analyse sont présentés (chapitre III). Le premier type se focalise sur une classe de composés : Les Hydrocarbures Aromatiques Polycycliques (HAP). L'intérêt de l'étude des HAP est double. D'une part ils sont, pour la plupart, considérés comme cancérogènes et mutagènes. D'autre part, ils sont émis quasi exclusivement par les combustions (dérivés du pétrole et biomasse) et leur étude permet de mieux appréhender les influences relatives des différentes sources anthropiques. Le second type d'analyses, plus exploratoire, consiste à réaliser une spéciation quantitative, la plus exhaustive possible, de la fraction organique et d'établir des relations entre la composition chimique, les sources, les saisons et les paramètres météorologiques. Des composés comme le guaiacol, la vanillin, le syringol (...) (émis par les feux de bois) ou comme la nopinone (composé secondaire) ont ainsi pu être quantifiés.
Les résultats obtenus ont permis de mettre en évidence :
- un apport anthropique important dans les deux vallées, pour les deux saisons et plus particulièrement en hiver où des concentrations en HAP très élevées et représentatives de grands centres urbains ont été observées (maximum 150 ng.m-3) ;
- des niveaux de concentrations en composés anthropiques primaires systématiquement plus importants dans la vallée de Chamonix, malgré l'absence du trafic des poids lourds;
- l'influence des conditions météorologiques et de la géomorphologie des vallées dans la dispersion des polluants ;
- une contribution très marquée des combustions de bois (chauffage domestique) dans la vallée de Chamonix l'hiver.
La spéciation quantitative de la MOP (chapitre III) a permis de déterminer globalement entre 10 et 74% du carbone organique. La fraction identifiée dépend de la saison considérée et est plus élevée l'hiver (34-74%) lorsque l'apport des sources primaires anthropiques est prépondérant. Cette variabilité saisonnière a mis en évidence les lacunes du protocole analytique utilisé, qui ne permet pas de quantifier la plupart des composés oxygénés polyfonctionnels et donc les composés constitutifs l'aérosol organique secondaire. Une méthode alternative de prélèvement et d'analyse de ces composés a été développée (Chapitre IV).
Lopes, Galasso Helena. "Bioremédiation des rejets de poissons par un polychète détritivore en vue d’un système aquacole intégré multi-trophique". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG013.
Integrated Multi-Trophic Aquaculture (IMTA) systems are based on the concept of limiting aquaculture discharges associating species of different trophic levels to reuse wastes. Deposit-feeders are one trophic group that has gained attention for the extraction of particulate organic matter. Hediste (Nereis) diversicolor is a polychaete species that has gained increasing interest for its bioremediation capacity through bioturbation activity in sediments, and high commercial value as fish bait and animal food sources. The main objective of this thesis was to evaluate the fish waste bioremediation capacity of polychaete H. diversicolor in IMTA context. More specifically, i) to predict organic compounds (nitrogen, carbon, phosphorus, lipids) in marine fish waste, ii) to evaluate the metabolic responses - respiration - of H. diversicolor fed with solid waste of seabass Dicentrarchus labrax at different temperatures and body size, and iii) to use a bioenergetic model (DEB) to simulate growth, oxygen consumption and excretion in different IMTA scenarios.To provide fast characterization of organic compounds we used an innovative method based on near infrared reflectance spectroscopy (NIRS). Chemical content of the waste measured by NIRS models after calibration, ranged from 44-77% organic matter, 2-5% total organic nitrogen, 11-51% total organic carbon, 9-26 carbon/nitrogen ratio, 1-3% total phosphorus and 2-12% lipids (% of dry matter).Fish waste fed H. diversicolor metabolic rates were evaluated through oxygen consumption at different temperatures (11, 17, 22 and 27°C). The effect of temperature and worm body size was significant on oxygen consumptions, however these respiration measures (12.3 µmol g-1 of dry weight h-1 at 20°C) may represent basal metabolic rate due to experimental conditions (starvation, darkness).DEB model of H. diversicolor was compared to experimental data on growth, respiration and excretion rates, which corroborated DEB model predictions. DEB was then applied to test different scenarios predicting metabolic responses, growth, maturity and reproduction of H. diversicolor at different temperatures (5 to 25°C) and food levels (f varying from 0 to 1, corresponding to fish waste loading). DEB revealed to be a useful tool in IMTA context, predicting physiological responses in different environmental conditions
Chen, Cheng. "Retrieving global sources of aerosol emissions from satellite observations". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R001/document.
Understanding of the role that atmospheric aerosol play in the Earth-atmosphere system is limited by uncertainties in aerosol distribution, composition and sources. Thus, accurate chemical transport model simulation systems are crucial needed to analyse and predict atmospheric aerosols and their impacts on climate change and environment. Satellite observations have ability to provide an extensive spatial coverage and accurate aerosol products, however, are constrained by clear-sky condition, global coverage orbit cycle and information content. One of the most promising approaches is to reduce model uncertainty by improving the aerosol emission fields (i.e., model input) by means of inverse modeling relying on satellite observations as a constrain. In this study, we designed a method of simultaneous retrievals of desert dust, black carbon and organic carbon aerosol emission sources using aerosol data obtained from GRASP algorithm applied to POLDER/PARASOL satellite observations, and relying on the GEOS-Chem inverse modeling framework. Then, a satellite-based global aerosol emission database (2006-2011) has been developed. This aerosol emission database has been further evaluated by utilization in GEOS-Chem and GEOS-5/GOCART models. The model posterior simulation of aerosol properties employing the retrieved emissions shows a better agreement than the model prior simulation; it is true for not only fitted PARASOL products, but also for completely independent measurements from ground-based AERONET and satellites aerosol products (e.g., MODIS, MISR, OMI). The results suggest that the satellite-based aerosol emission database improves overall global aerosol modeling
Rivellini, Laura-Hélèna. "Propriétés physico-chimiques, optiques et identification des sources des aérosols en Afrique de l’Ouest". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10177/document.
The aim of this thesis consists in studying the chemical nature, the origins as well as the optical properties of aerosols in West Africa. We focused on establishing the links between the chemical composition of fine particles at surface and aerosols optical properties. Our study is based on measurements acquired during the SHADOW field campaign, implemented on the M’Bour (Senegal) site during two intensive observation periods: March to June 2015 (IOP-1) and November 2015 to January 2016 (IOP-2). For this purpose, an instrumentation allowing online chemical characterization of surface PM1 (ACSM, TEOM-FDMS, aethalometer), at high time resolution, was implemented in parallel with instruments measuring aerosols optical properties at surface (aethalometer, nephelometer) and along the atmospheric column by remote sensing (Lidar, photometer). The coupling of meteorological data with statistical tools allowed determining the local and/or regional contribution of the different species, and identifying the source areas responsible for the high concentrations observed on site. The source receptor model (PM) allowed to further investigate the submicronic organic fraction, highlighting a fast photochemistry and the influence of specific anthropogenic activities (waste burning, fish smoking). We were also able to characterize, per season, the type of aerosols contributing to the fine particle extinction measured at surface, as well as to show links/differences between remote sensing and surface chemical/optical properties of fines particles during the two IOP
Beauvais, Sophie. "Etude des Particules Exopolymériques Transparentes (TEP) en milieu marin. Dynamique et rôle dans le cycle du carbone". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00003711.
Roig, Rodelas Roger. "Chemical characterization, sources and origins of secondary inorganic aerosols measured at a suburban site in Northern France". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R017/document.
Tropospheric fine particles with aerodynamic diameters less than 2.5 µm (PM2.5) may impact health, climate and ecosystems. Secondary inorganic (SIA) and organic aerosols (OA) contribute largely to PM2.5. To understand their formation and origin, a 1-year campaign (August 2015 to July 2016) of inorganic precursor gases and PM2.5 water-soluble ions was performed at an hourly resolution at a suburban site in northern France using a MARGA 1S, complemented by mass concentrations of PM2.5, Black Carbon, nitrogen oxides and trace elements. The highest levels of ammonium nitrate (AN) and sulfate were observed at night in spring and during daytime in summer, respectively. A source apportionment study performed by positive matrix factorization (PMF) determined 8 source factors, 3 having a regional origin (sulfate-rich, nitrate-rich, marine) contributing to PM2.5 mass for 73-78%; and 5 a local one (road traffic, biomass combustion, metal industry background, local industry and dust) (22-27%). In addition, a HR-ToF-AMS (aerosol mass spectrometer) and a SMPS (particle sizer) were deployed during an intensive winter campaign, to gain further insight on OA composition and new particle formation, respectively. The application of PMF to the AMS OA mass spectra allowed identifying 5 source factors: hydrocarbon-like (15%), cooking-like (11%), oxidized biomass burning (25%), less- and more-oxidized oxygenated factors (16% and 33%, respectively). Combining the SMPS size distribution with the chemical speciation of the aerosols and precursor gases allowed the identification of nocturnal new particle formation (NPF) events associated to the formation of SIA, in particular AN
Garel, Marc. "Méthodes, procédures et techniques hyperbares pour l'étude des microorganismes du milieu profond en condition in situ". Electronic Thesis or Diss., Aix-Marseille, 2021. http://www.theses.fr/2021AIXM0378.
The ocean is deep, with the majority of its volume (>80%) at depths greater than 1000 m, and is poorly sampled (<0.01%). It is characterized by high hydrostatic pressure, low temperature, high inorganic nutrients and low organic carbon concentrations. Substrate input is primarily from primary production in the form of particulate and dissolved organic matter. The particulate and dissolved labile fractions are mainly consumed in surface waters by prokaryotes, leaving only a so-called refractory fraction as the only carbon source for prokaryotes in the bathypelagic zone. Most measurements of metabolic activity and diversity of bathypelagic prokaryotes are generally underestimated due to sample decompression. To study prokaryotes under in situ conditions, we have a hyperbaric technology that can be used as a ready-to-use pressurized sampler capable of collecting and maintaining samples under in situ conditions, but also to simulate the increase of hydrostatic pressure. The results highlight that by maintaining the pressure conditions, it is possible to sample piezophilic microorganisms. These results confirm our experimentation on the degradation of high molecular weight dissolved organic matter by a community adapted to the deep environment. Finally, we have also shown the importance of environmental conditions to study the fate of organic matter in the water column
Siepka, Damian. "Development of multidimensional spectral data processing procedures for analysis of composition and mixing state of aerosol particles by Raman and FTIR spectroscopy". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10188/document.
Sufficiently adjusted, multivariate data processing methods and procedures can significantly improve the process for obtaining knowledge of a sample composition. Spectroscopic techniques have capabilities for fast analysis of various samples and were developed for research and industrial purposes. It creates a great possibility for advanced molecular analysis of complex samples, such as atmospheric aerosols. Airborne particles affect air quality, human health, ecosystem condition and play an important role in the Earth’s climate system. The purpose of this thesis is twofold. On an analytical level, the functional algorithm for evaluation of quantitative composition of atmospheric particles from measurements of individual particles by Raman microspectrocopy (RMS) was established. On a constructive level, the readily accessible analytical system for Raman and FTIR data processing was developed. A potential of a single particle analysis by RMS has been exploited by an application of the designed analytical algorithm based on a combination between a multicurve resolution and a multivariate data treatment for an efficient description of chemical mixing of aerosol particles. The algorithm was applied to the particles collected in a copper mine in Bolivia and provides a new way of a sample description. The new user-friendly software, which includes pre-treatment algorithms and several easy-to access, common multivariate data treatments, is equipped with a graphical interface. The created software was applied to some challenging aspects of a pattern recognition in the scope of Raman and FTIR spectroscopy for coal mine particles, biogenic particles and organic pigments
Chevrier, Florie. "Chauffage au bois et qualité de l’air en Vallée de l’Arve : définition d’un système de surveillance et impact d’une politique de rénovation du parc des appareils anciens". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAU020/document.
Biomass burning is one of the major sources of atmospheric particles during wintertime in Alpine valleys, and more especially in the Arve valley where exceedances of the European regulated limit value are regularly observed. This situation led to the establishment of an important program of replacement of old wood stoves with new ones as part of an action of an Atmospheric Protection Plan (APP), the “Fonds Air Bois”. The research program DECOMBIO (“DÉconvolution de la contribution de la COMbustion de la BIOmasse aux PM10 dans la vallée de l’Arve”) has been set up in October 2013 to estimate the impact of this wood stoves renewal policy on air quality. This thesis works be incorporated within this program and have for main objective to validate methodologies used in routine to enable a fast deconvolution of the biomass burning source and to compare any observed changes with progress of wood stove changeout.To complete this work, three sites, representing the different situations of the Arve valley, were instrumented (Marnaz, Passy and Chamonix) to monitor the continuing evolution of atmospheric concentrations of Black Carbon (BC) and molecular markers enabling to distinguish between the biomass burning contribution and that of other types of combustion. A large dataset was acquired between November 2013 and October 2014 thanks to regular filter samples enabling a vast chemical characterization of PM10. The use of statistical analysis “Positive Matrix Factorization” (PMF) has led to an enhanced appreciation of particle emission sources within this valley with a focus on biomass burning emissions. The development of this methodology of identification and source apportionment based on the use of specific organic markers, specific constraints and data from carbonaceous matter deconvolution is an important progress in definition of factors from this model.The developed methodologies during this work, enabling an improvement of knowledges and source apportionment, are tools directly usable by French Accredited Associations for Air Quality Monitoring, especially for the quantitative assessment of actions introduced to improve air quality as part of Atmospheric Protection Plans, for example the one in the Arve valley
Sioud, Khaled. "Transfert de métaux entre eau et suspensions dans les estuaires". Phd thesis, Marne-la-vallée, ENPC, 1994. http://pastel.archives-ouvertes.fr/pastel-00574027.
Lovrić, Josip. "Molecular modeling of aerosols". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10080/document.
In this thesis numerical methods are used to study the properties, described at the molecular level, of organic aerosols, especially marine aerosols, and their interaction with species in the atmosphere. The organisation of the organic matter in these aerosols plays a key role for their optical, chemical properties, and their ability to act as a cloud condensation nuclei.The first part reviews atmospheric context and the methods (classical molecular dynamics and hybrid quantum/classical approaches) used in this thesis. Then applications to three cases are detailed.Firstly, the organization, more particularly the orientation, of palmitic acid molecules adsorbed on a salt (NaCl) surface as a function of the fatty acid coverage and temperature has been studied using classical molecular dynamics (Gromacs package). The impact of the humidity on the structuration of this organic coating has been described in details, showing the existence of structured fatty acid island-like monolayers on NaCl surface.In a second study, the reactivity of NO2 with these heterogeneous marine aerosols has been investigated by a hybrid quantum/classical method (CP2K package), with taking into account the effect of the humidity.The last study is a classical molecular dynamics of n-butanol crystal, water accommodation at these surfaces and simulation of water jet collision with n-butanol surface. These simulations, complementary to experiments, were performed to better understand the fundamental role of the water-organic matter interaction on the properties of the aerosols and clouds
Badran, Ghidaa. "Pollution atmosphérique particulaire : caractérisation physico-chimique et comparaison des effets toxiques des fractions extractible et non-extractible des PM₂.₅ In-vitro evaluation of organic extractable matter from ambient PM₂.₅ using human bronchial epithelial BEAS-2B cells : Cytotoxicity, oxidative stress, pro-inflammatory response, genotoxicity, and cell cycle deregulation. Toxicity of fine and quasi-ultrafine particles : focus on the effects of organic extractable and non-extractable matter fractions. Toxicological appraisal of the chemical fractions of ambient fine (PM₂.₅-₀.₃) and quasi-ultrafine (PM₀.₃) particles in human bronchial epithelial BEAS-2B cells". Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0547.
Air pollution and particulate matter (PM₂.₅) were classified as carcinigens (group 1) by the International Agency for Research on Cancer in 2013. This particulate fraction represents a complex mixture with a highly variable composition influencing the toxicity. However, few studies have determined the respective involvement of the different chemical fractions of PM in their toxic effects. In this work, fine particles (PM₂.₅₋₀.₃) and quasi-ultrafine particles (PM₀.₃) were sampled in an urban site located in Beirut (Lebanon). After performing the physicochemical characterization of these two types of particles, their toxic effects (global cytotoxicity, metabolic activation, genotoxicity, inflammation, oxidative stress, autophagy and apoptosis) were investigated on a human bronchial epithelial cell line (BEAS-2B). The analysis of the organic content revealed differences between the concentrations of polycyclic aromatic hydrocarbons (PAHs), as welle as oxygenated (O-PAH) and nitrated (N-PAH) congeners, respectively 43, 17 and 4 times higher in PM₀.₃ than in PM₂.₅₋₀.₃.The toxicological study was based on the comparison of the toxicity of the fine particles considered in their entirety (PM₂.₅₋₀.₃), the extracted organic fraction (OEM₂.₅₋₀.₃) and the fraction not extracted by the dichloromethane (NEM₂.₅₋₀.₃). In addition, the specific effects of the organic fraction extrated from the quasi-ultrafine particles (OEM₀.₃) were compared with those of the organic fraction extracted from the fine particles (OEM₂.₅₋₀.₃). Our results showed that all the studied fractions were able to induce at least one of the studied mechanisms. PM₂.₅₋₀.₃ was able to induce toxic effects greater than those induced by OEM₂.₅₋₀.₃ and NEM₂.₅₋₀.₃. The organic fraction extracted from the quasi-ultrafine particles (OEM₀.₃), richer in organic compounds and in particular in PAHs and other congeners, appeared to be responsible for deleterious effects globally greater than that extracted from the fine particles (OEM₂.₅₋₀.₃). The results of this work have brought new elements on the relative toxicity of the different fractions of the fine particles and underline the crucial role played by ultrafine particles, still too little studied
Leobold, Matthieu. "Démonstration fonctionnelle de la nature virale des particules sans ADN de la guêpe parasitoïde venturia canescens". Thesis, Tours, 2018. http://www.theses.fr/2018TOUR4017.
Viral particles devoid of DNA called VLPs (for Virus-Like Particles) are specifically produced in the ovaries of the parasitoid wasp Venturia canescens and line the chorion of the wasp’s eggs injected into the host caterpillar. VLPs are immunosuppressive and allow parasitoid eggs survival. These VLPs result from the integration of a nudivirus into the wasp ancestor genome, nudivirus which was then domesticated to form viral liposomes capable of carrying, into the host, virulence proteins of cellular origin. The aim of the study carried out during this thesis was, first, to analyze the viral domestication mechanisms that led to the current endogenous symbiotic virus called VcENV (for V. canescens endogenous nudivirus) and secondly to provide some answers on VLPs morphogenesis process and parasitic mode of action