Дисертації з теми "Matière organique – Origines – Composition chimique"
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Marrocchi, Yves. "Incorporation des gaz rares dans la matière organique primitive du système solaire." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2005. http://tel.archives-ouvertes.fr/tel-00258016.
Piani, Laurette. "Origine des éléments volatils dans le Système Solaire : la matière organique et les argiles des chondrites." Phd thesis, Museum national d'histoire naturelle - MNHN PARIS, 2012. http://tel.archives-ouvertes.fr/tel-00770244.
Thlaijeh, Siveen. "Characterization of organic matter by laser-assisted mass spectrometry : application to paleontology and exobiology." Thesis, Université de Lille (2018-2021), 2021. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2021/2021LILUR066.pdf.
The origin of organic matter on Mars will be investigated with ExoMars’ “Rosalind Franklin” rover using several analytical instruments including the Mars Organic Molecular Analyzer (MOMA). The MOMA instrument combines laser desorption-ionization mass spectrometry (LDI-MS) and gas-chromatography mass spectrometry (GC-MS) to analyze sub-surface samples. The similarity of the LDI-MS of MOMA with our LDI-MS / L2MS (two-step laser mass spectrometry) instrument has encouraged us to characterize organic matter from different types of samples, with the goals of providing new methodology for microscale molecular characterization of early life on Earth and to support future investigations on Mars.First, we developed a new-side injection ion source for our existing hybrid (radiofrequency/time-of-flight) mass spectrometer enabling transmission and reflection microscopy and chemical imaging in L2MS and LDI-MS with a lateral resolution down to 3 µm.Second, characterization of reference molecules was carried with L2MS and LDI-MS to help chemical identification of different types organic matter. These included a tryptophan derivative (biotic/abiotic amino acid), hexylthiophene (proxy for sulfurized hydrocarbons), cholestane (eukaryote biomarker), tocopherol (from photosynthesizers) and a porphyrin (chlorophyll derivative). Thus, we provide insight into the sensitivity of the method for these important classes of molecules, and into their fragmentation patterns.Third, a sedimentary rock from the Jurassic paleolagoon of Orbagnoux was analyzed as a proxy for diagenetically-sulfurized microbial organic matter. This sample was chosen following the recent detection of sulfurized molecules on Mars. Chemical characterizations of different samples of Orbagnoux rock (fresh rock and polished slice) and its corresponding sub-fractions extracted from the sedimentary rock (soluble extracts, maltene and kerogen) were performed using L2MS and LDI. This gives access to organic and inorganic molecular information of various chemical classes of interest such as polycyclic aromatic hydrocarbons, oxygenated, thiophenic, and nitrogenated hydrocarbons, calcium carbonate/iron sulfide clusters, and metals such as Ni+ or VO+ that point to the preservation of geoporphyrins.Fourth, a modern Dammar resin and four fossil resins (ambers) were analyzed in LDI-MS to test the technique capability to provide insights into plant-derived fossil biopolymers, including their maturity grade and/or botanic type. Clear differences in hydrocarbon fragment patterns were observed in mass spectra and analyzed with principal component analysis
Gobé, Valérie. "Matière organique complexe du sol ; structure et rôle dans les processus d'humification du carbone xénobiotique." Poitiers, 1998. http://www.theses.fr/1998POIT2316.
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
Bigot, Marianne. "Biogeochimie de la matiere organique dans l'estuaire du huang he et en mer de bohai." Paris 6, 1988. http://www.theses.fr/1988PA066083.
Kouakoua, Ernest. "La matière organique et la stabilité structurale d'horizons de surface de sols ferrallitiques argileux : effet du mode de gestion des terres." Nancy 1, 1998. http://www.theses.fr/1998NAN10016.
Mortillaro, Jean-Michel. "Caractérisation et dynamique de la matière organique du fleuve et des plaines d'inondation du bassin central amazonien." Paris, Muséum national d'histoire naturelle, 2012. http://www.theses.fr/2012MNHN0003.
River ecosystems have a key role in the processes, which control the storage of atmospheric CO2. However, because of strong spatial and temporal variabilities in the sources of organic matter (OM), their relative contribution to the carbon dynamics of large river ecosystems is not fully understood. The present work aimed to characterize the sources of OM in the central Amazon basin. The fatty acids (FA) and stable carbon and nitrogen isotopic (δ13C, δ15N) compositions of OM were investigated in five floodplains (locally called Várzea), the Amazon River and four of its main tributaries (Solimões, Negro, Madeira and Tapajós). The OM analyzed includes macrophytes (Eichornia sp. , Paspalum repens, Pistia stratiotes and Salvinia auriculata), plankton samples, suspended particulate organic matter (SPOM), sediments and soils from the flooded forest. A seasonal characterization of this OM, according to the annual oscillation in the hydrological cycle, indicates a strong autotrophic production from cyanobacteria in Várzea during the drought season. At this season, a transfer of OM, resulting from cyanobacteria and decomposition of macrophytes, has been evidenced from the Várzea to the rivers. However, these plants, which use different pathways of photosynthesis, do not contribute equally to OM and to the food web. Thus, a degradation experiment showed the decomposition dynamics of these macrophytes and the role of micro-organisms. The characterization of OM sources, their spatial and seasonal variabilities, the processes involved in its degradation as well as its utilization by consumers, indicate that the OM produced in Várzea constitute the major source of respired carbon in rivers from the Amazon basin and results from phytoplanktonic production
Rouibah, Mohamed. "Relations entre la composition chimique des eaux interstitielles et les caractéristiques des dépots récents sur la marge rhodanienne (Golfe du Lion) : mécanismes de digénèse précoce de la matière organique." Perpignan, 1993. http://www.theses.fr/1993PERP0154.
Biron, Katarzyna. "The Molecular structure of the Insoluble Organic Matter (MOI) deposited from organic plasma : Comparison with IOM isolated from carbonaceous meteorites." Thesis, Paris, Muséum national d'histoire naturelle, 2016. http://www.theses.fr/2016MNHN0004/document.
Carbonaceous meteorites are the most primitive objects of the solar system. They contain up to 4% of carbon, mainly occurring as insoluble organic matter (IOM). This IOM contains key information about the organo-synthesis processes taking place in the Solar System, which are so far poorly understood. A statistical model was recently proposed for the IOM molecular structure along with a possible synthesis pathway for its hydrocarbon backbone (Derenne and Robert, 2010).The first aim of this work was to test experimentally this pathway using an organic plasma as a source of CHx radicals. This device allowed the formation of both soluble and insoluble OM. The IOM was analyzed through the same techniques as those previously used for the chondritic IOM, revealing numerous similarities between both materials and thus supporting the proposed pathway. Moreover, NanoSIMS analyses revealed large isotopic variations at a sub-micrometric spatial resolution that are commensurable with those observed in chondritic IOM.Then, the source of heteroatoms (N and O) into the IOM was experimentally investigated through the addition of heteroelement-containing precursors to the hydrocarbonaceous radicals. As for nitrogen, two types of precursors were considered: hexylamine as a source of nitrogen hydrides and N2. Although both precursors led to nitrogen incorporation in the IOM, nitrogen hydrides seem to be more relevant based on the nitrogen speciation. Two types of experiments were performed to investigate the potential source of oxygen in the chondritic IOM. They were designed to address the two main scenarios proposed in the literature to account for the origin of the oxygen in the chondritic IOM: either aqueous alteration on the asteroidal parent body or O incorporation during the organo-synthesis in the primitive solar nebula. When the aqueous alteration is mimicked, the chemical composition of the SOM and IOM makes this pathway a reasonable source of the chondrite oxygen moieties. In contrast, no evidence for direct incorporation of O from OH radicals could be brought
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
Demon, Michel. "Influence des facteurs climatiques et des constituants du sol sur la dynamique de l'atrazine." Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL092N.
Fernandes, Paula. "Effets des modes de gestion des terres en zone sahélienne sur les termes et l'évolution de leur bilan organique et biologique : consequences pour une production céréalière soutenue : cas du Sénégal." Vandoeuvre-les-Nancy, INPL, 1999. http://docnum.univ-lorraine.fr/public/INPL_T_1999_FERNANDES_P.pdf.
In the sahelian zone, sail organic matter (SOM) and microbial biomass (MBc) are two essential components of soil fertility, SOM because of it's role in sail physical properties and stock of nutrients, and MBc as the key of most of the biological processes involved in SOM evolution. Our objective is (1) to evaluate the effects of organic inputs on sail fertility, using chemical and biological variables as well as yield components and (2) to determine the relationships between these variables so as to define types of soil behaviour that could explain the large variability of the response to manure in field conditions. We worked on medium-term and annual experiments as weil as a multilocal experiment in field conditions. Our variables are soil physico-chemical caracteristics, MBc, nitrification determined in situ (Nitn1) and in controlled conditions (Nitpot) as the biological variables, and plant prùductivity as an integrative variable. Our results confirm the fast degradation of SOM the first year of cultivation after 15 years of herbaceous fallow (-40% C the first year). This study also presents new results : (1) it validate, in field conditions, the increase of MBc during the cultivation period observed by other authors in agronomical station and precises the relationships between soil biological component (MBc and Nitm) and chemical ones (CEC, SOM) ; (3) it shows that the variability of the soil and plant reponse to manure is a function of it's composition and of the ecological zone; this variability is used to define types of sail behaviour; (4) it shows that residual effects of manure is still sensible, even after two years, on yield and MBc. This work also led to methodological studies. Controlled conditions are necessary for a better knowledge of biological mecanisms
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
Saenger, Anaïs. "Caractérisation et stabilité de la matière organique du sol en contexte montagnard calcaire : proposition d'indicateurs pour le suivi de la qualité des sols à l'échelle du paysage." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENS010/document.
Mountain soils are major reservoirs of carbon (C), potentially vulnerable to climate and land use changes that affect them significantly. However, the great variability of these soils, their limited accessibility and the lack of appropriate measurement tools restrict our knowledge. Today, our comprehension of the biogeochemistry of mountain soils remains very incomplete regarding stocks, chemistry and reactivity of soil organic carbon (SOC). Yet this information is necessary to understand the evolution of soil carbon in the current context of global change. The objectives of this work were (i) to gain a better understanding of the nature, stability and vulnerability of SOC in a mosaic of ecosystems in a calcareous massif in the Alps (Vercors massif), (ii) to search for fast and reliable characterization tools, suitable for the study and monitoring of COS at the landscape scale, and (iii) to propose indicators for the assessment and monitoring of soil quality in mountain regions. As a first step, we tested the application of Rock-Eval pyrolysis for the study of COS at large-scale on a set of ecosystem units. Then, we compared the Rock-Eval approach to two conventional techniques for soil organic matter (SOM) study: the particle-size fractionation of SOM, and the mid-infrared spectroscopy. These coupled analytical approaches allowed us to quantify C stocks across the study area, and explain the stability and the vulnerability of COS at various angles. Factors responsible for the patterns observed in the different eco-units are discussed. This work also confirmed the relevance of the Rock-Eval tool to achieve our previous objectives. Biological approaches allowed us to assess the significance of microbial pool in these soils. Finally, indices assessing the status of SOM (SOC storage, soil fertility, vulnerability COS) were proposed and constituted interesting management tools for decision-makers
Moretto, Robert. "Étude sédimentologique et géochimique des dépôts de la série salifère paléogène du bassin de Bourg-en-Bresse (France)." Nancy 1, 1986. http://www.theses.fr/1986NAN10393.