Дисертації з теми "Complexe de carbone(0)"
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Gigou, Thomas. "Vers des complexes de carbone(0) à l'aide de la chimie de l'iode hypervalent : Nouveaux ylures d’iodonium nucléophiles stabilisés par une sulfone." Electronic Thesis or Diss., Bordeaux, 2023. http://www.theses.fr/2023BORD0501.
Bis ylides are divalent carbonated s pecies on which a central carbon atom bears two negative charges, both stabilized by two α, positively charged heteroatoms. Selectively transferring the central carbon atom, using both ylides simultaneously is of great interest for synthetic chemists. Such atomic carbon sources are scarce, as most of the bis ylides developed until now were too tightly bind to his ligands. With this in mind, this thesis ambitions to develop bis ylides and other reactive species containing an iodonium ligand, an extremely labile fragment which could allowed an efficient liberation of the central carbon atom. The first chapter is dedicated to the state of the art of “carbon(0)” compounds and their application as atomic carbon sources, as well as the structure and reactivity of hypervalent iodine compounds. The second chapter is about releasing bis ylides by cleaving a covalent bond, either a P C bond from a phosphine oxide stabilized mixt phospho iodonium ylide, or a Si C bond from a silane stabilized mixt phospho iodonium ylide. A third chapter explains our attempts to obtain bis ylides precursor by direct iodination of nucleophilic phosphonium or sulfoxonium ylides. The last chapter is dedicated to our attempt to develop an iodonium yldiide, in which only one of the two negative charges borne by the central carbon is next to a positively charged heteroatom, the other being stabilized by a sulfonyl mesomeric and inductive effects. The results of those attempts allowed us to describe the reactivity of a new nucleophilic, mono stabilized iodonium ylide towards aldehydes
Boussouf, Karim. "Etude systématique des complexes Znq+Imn (où q = 0, 1, 2; n = 1 – 4)." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1094/document.
The main goal of this work is to examine the capabilities of M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3 and M11 functionals with and without inclusion of D3 dispersion correction for the accurate description of medium sized organometallic compounds and therefore their use for the determination of study of the equilibrium structure, the stability, the spectroscopy and the chemical bonding (covalent, charge transfer and van der Waals) of Znq+Im (q = 0,1,2) complexes. This is done through close comparisons of the results obtained by the M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3, M11 functionals with and without inclusion of D3 dispersion correction and those from the standard ((R)MP2 and (R)CCSD(T)) and explicitly correlated ab initio methods (R)CCSD(T)-F12 and (R)MP2-F12. Therefore, we definitely establish that M05-2X+D3 and PBE0+D3 in connection with the 6-311++G(d,p) basis set are the methods of choice for the accurate description of medium sized organometallic compounds. This is illustrated through a systematic study of Zn+qIm of (q=0, 1, 2) complexes which play crucial roles in chemical, biological and industrial domains. Through these comparisons, we show that the results obtained at the M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3, M11 levels are in good agreement with those explicitly correlated (R)MP2-F12 and (R)CCSD(T)-F12 methods. Through these comparisons, our study establishes the ability and reliability of M05-2X(+D3) functional for the accurate description of covalent and noncovalent interactions between Znq+ and Im since it leads to close agreement with the large ab initio techniques. PBE0 and M11 may be used also for that purposes. Then, we used high performance M05-2X and PBE0 functionals with and without inclusion of D3 dispersion correction in connection along with the 6-311++G(d,p) basis set to study the equilibrium structure, the stability, the spectroscopy and the chemical bonding (covalent, charge transfer and van der Waals) of Znq+Imn (q = 0, 1, 2, n = 1−4) complexes. This work, at the microscopic level, is useful for understanding the structural and bonding occurring in naturally zinc-binding sites and to figure out the behavior of much more complex biological systems. This should help for designing new zinc-binding proteins and more generally new metal sites in known proteins or ZIFs. The structural backbone of ZIFs is constructed from tetrahedral units formed by one bivalent metal ion (M2+ = Zn2+/Co2+) and four imidazolate anions. Such compounds present a well-established structural topology with a large structural diversity. They exhibit a high porosity which is potentially used for gas storage and separation techniques.Such quantities at the microscopic level are needed to deduce the macroscopic and thermochemical properties of these compounds with good accuracy after incorporation into dynamical simulations
Levell, Tamzyn J. "Substituted Fischer carbene complexes of molybdenum(0)." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/46250.
Dissertation (MSc)--University of Pretoria, 2014.
tm2015
Chemistry
MSc
Unrestricted
Fraser, Roan. "Fischer and N-heterocyclic carbene complexes of chromium(0)." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/31504.
Dissertation (MSc)--University of Pretoria, 2012.
Chemistry
MSc
Unrestricted
Pretorius, René. "Fischer and N-heterocyclic carbene complexes of tungsten(0)." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/31515.
Dissertation (MSc)--University of Pretoria, 2012.
Chemistry
MSc
Unrestricted
Raude, Amandine. "Modélisation thermomécanique d'un composite carbone/carbone à texture complexe." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0260/document.
C/C composites are used in space and aeronautics for their excellent thermomechanical properties from room temperature to very high temperatures (> 3000°C). These materials have a complex architecture consisting of layers of laminated and needled fibers. Its use in highly stressed areas and at high temperature requires control of thermal and mechanical properties. Currently, the design of the material is done empirically and iteratively. To accelerate it, the development of a multi-scale digital model of the C/C composite is proposed. This material was first morphologically characterized at its different characteristic scales, the thermomechanical properties of its elementary constituents were also identified. At the microscopic scale, the wires are represented homogeneously and thermoelastically from the constituent levels associated with them. At the mesoscopic scale, two morphological aspects seem to predominate: its architecture as well as its porosities and damages. Their effect on the effective behavior of the C/C composite is studied in order to evaluate their relative influence and to arrive at a sufficiently fine description of their morphologies in the modeling carried out. An idealized material model as well as an image based model have been developed. The simulation of macroscopic tests revealed that both aspects had a non-negligible effect on the effective behavior of the C/C composite and allowed the development and validation of a multi-scale predictive model of this material, taking into account the preceding characteristics, and allowing the link between the scale of its elementary constituents and the macroscopic one
Rochon, Alexandra. "Cycloaddition Reactions of Ni(0) Difluorocarbene Complexes: Investigating the Formation of Various Perfluorometallacycles." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39026.
Stortoni, Federica. "Clinique contemporaine des Français d’origine italienne : une posture complexe : "Je suis Français… mais mon père était italien…"." Paris 8, 2007. http://octaviana.fr/document/133380785#?c=0&m=0&s=0&cv=0.
As a result of around forty research interviews with Italians and Italian descendants in Paris, the author has ascertained that this specific group demonstrates a complex position, which in psychology refers to identity theories and can be described as a position based on invisibility and silence. In fact, the descendants of Italian migrants describe themselves through their French “attachments” but simultaneously they discreetly demonstrate their Italian “attachments”, which return in moments of life transition (the birth of a child, the death of a parent) and in difficult life experiences. Various identity theories have proven to be insufficient for explaining this unique position, thus the notion of “attachments” seems more appropriate. The author investigates the particular history of this group, which is intimately connected to migration, in order to understand how these generations have been thought of by their parents, society and through various historical events. The author puts forth two main hypotheses: there is a construction strategy that remains incomplete over many generations. Italy, as part of the puzzle of this group, could be a source for therapeutic instruments and devices as long as the active therapeutic Italian elements are located and are applied in a specific system that is both clinical and dedicated to ethnopsychiatric study. These resources function as technical tools for constructing "becomings" (in the Deleuzian sense). "
Ansell, Melvyn B. "Novel (N-heterocyclic carbene)-palladium(0) complexes as catalysts in element-element bond additions to unsaturated moieties." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/68072/.
Autier, Antoine. "Charles Rist et la question de la dévaluation en France (1919-1937) : un "complexe monétaire" à l'épreuve des faits." Paris 8, 2012. http://octaviana.fr/document/177810785#?c=0&m=0&s=0&cv=0.
The thesis aims at explaining the positions taken by the French economist Charles Rist when, at two different moments in the period 1919-1937, he was confronted to the same question: whether or not devaluating the franc? This thesis, which mixes the History of economic thought and the History of economic facts, is structured in three parts. The first provides an overview of the French economy in the entire period. The second shows how Rist expressed his ideas on monetary stabilization in the 1920s, and more precisely the way he took part to the stabilization of the franc. The third goes on analyzing the monetary ideas of Rist in the environment of the 1930s when the economic crisis was followed by a currency crisis setting in motion the collapse of the gold standard, and specifies the evolution of his position on the devaluation of the franc. In the conclusion we embrace the whole course of Rist and we enlighten it with analytical elements derived from his theoretical work to identify the existence in him of a "monetary complex", but also to determine how much he could overcome it in different historical contexts
Giralt, Anne. "Action de groupe sur un complexe cubique CAT(0) et revêtements ramifiés." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066088/document.
The goal of this thesis is to study of branched covers V' to V of closed hyperbolic manifolds that can be cubulated, i.e. Whose fundamental group pi_1(V) acts properly and cocompactly on a CAT(0) cube complex. We give sufficient conditions for pi_1(V') to be cubic as well.We tackle this question in two different ways. In a first approach we build a negatively curved cubical complex as a ramified cover of a cubical complex obtained by cubulating V. Then the main issue is to check that the fundamental group of this complexe is isomorphic to the fundamental group of V'. We manage to do so when V' is so called “Gromov-Thurston manifold “. Our second approach deals with the more general case where the branched locus of V' to V is contained in a codimension 1 convex submanifold. The preimage of this submanifold on V' and on the universal cover X' of V' provides a natural system of “walls”. Then the main issue is to show that these walls linearly separate X'. This enables us to use classical cubulation theorems
Vidal-Letourneur, Véronique. "Synthèse et caractérisation du complexe bis(siloxy)hydruro-tantale supporté sur silice : application à la métathèse des alcanes." Lyon 1, 1997. http://www.theses.fr/1997LYO10300.
Tahiri, Mohamed. "Phtalocyanines de fer(i) et de fer(0) : synthese, structure et reactivite." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13043.
Dawson, Elizabeth Anne. "A study of the formation, properties and catalytic activity of novel copper-carbon materials prepared by the thermal decomposition of a copper(0) cellulose complex." Thesis, Leeds Beckett University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293345.
Rouillon, Astrid. "Regulation transcriptionnelle par le complexe ubiquitine ligase scf m e t 3 0." Paris 11, 2000. http://www.theses.fr/2000PA112112.
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.
Kuhl, Sébastien. "Activation de liaisons carbone-halogène et carbone-azote par des catalyseurs de nickel(0) ligandés par un carbène N-hétérocyclique." Nancy 1, 2005. http://www.theses.fr/2005NAN10112.
This work describes the preparation of new nickel catalysts liganded with N-heterocyclic carbenes for the reduction of (poly)halogenated arenes and imines and for the N,N'-diarylation of aromatic diamines. In a first part, the Ni(0)/IMes (1/2) catalyst, associated to i-PrONa, was used for the reduction of (poly)chlorinated arenes. Carbon-fluorine bonds of fluoroarenes can also be activated by the Ni(0)/IMes (1/1) catalyst and be reduced in the presence of the secondary alkoxide Et2CHONa. Transfer hydrogenation of imines into amines is also possible with this catalyst. In the second part, the development of a new nickel catalyst, noted Ni(0)/IPr (1/2), for the N,N'-diarylation of aromatic diamines is described. The synthesis of new N,N'-diaryldiamines containing a 4-[10-(4-aminophényl)-9-anthryl]aniline moiety is reported. It has been shown that the diaryldiamines possess fluorescent properties and that they were reversibly oxidized into stable di(radical cation)s
Bousquet, Laura. "Synthèse et réactivité d'espèces divalentes du carbone : bis-ylures et yldiures." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30342/document.
Bis-ylides can be viewed as carbon (0) complexes, also known as " Carbone ". The goal of this thesis is to develop new models of bis-ylides featuring original reactivities. The first chapter presents the state of the art of carbon(0) complexes. A study of their electronic and structural properties is described, as well as, their applications as ligands in organometallic chemistry and their uses as potential carbon atom sources. The second chapter records the different attempts to synthesize a new cyclic P,S bis-ylide. These efforts lead to the unexpected synthesis of new P-chlorinated mixed bis-ylide precursors. Some preliminary results allow us to class them in the family C(0) complexes. The third chapter consists in the synthesis of a new family of bis-ylides, stabilized by sulfoxonium group. These species were fully characterized theoretically, spectroscopically and by X-Ray diffraction. The reactivity studies demonstrate a high potential as ligand for transition metal, several organometallic complexes were prepared and characterized. The last chapter presents the study of anionic bis-ylides, also known as yldiide. The synthesis of a new model is described, as well as its reactivity towards carbonyls. Finally, original irradiation reactions of this yldiide allowed us to access new C(0) complexes
Neculman, Cerda Rodrigo Alexis. "Carbon stabilibation and destabilisation processes operating in top- and subsoil of andisols under temperate rainforest, Southern Chile." Paris 6, 2013. http://www.theses.fr/2013PA066373.
Soil carbon (C) sequestration is a strategy to capture atmospheric CO2 and transfer it into stable soil organic carbon (SOC) forms. There are a number of mechanisms of C stabilisation and destabilisation influencing soil C cycling. Few studies have been carried out to investigate those processes in Andisols despite the fact that the carbon storage potential of Andisols is higher than in any other soil type. Stable carbon occurs in this soil type due to its association with aluminum- and iron-oxides together with amorphous clay minerals like allophane and imogolite type materials. In this thesis I investigated the factors and mechanisms that control the C stabilization in the top- and subsoil horizons of volcanic temperate old growth rainforest soils in Southern Chile. I investigated organic matter quantity, composition and turnover in all three horizons of two soil profiles with contrasting age and texture. I used radiocarbon dating, 13C NMR spectroscopy and wet chemical extraction to characterize the composition of organic and mineral phases. Moreover, I evaluated the susceptibility of C in these profiles to priming after addition of 13C labelled substrate. The results showed contrasting mineral stabilization agents in the two soils of different age: iron and aluminum complexes stabilized carbon in the youngest soils whereas allophane was the most important stabilization in the older soil. Despite the contrasting stabilization agents, the composition of the organic matter stored throughout the two soil profiles was similar. Organic matter in top soil horizons was subject to negative priming whereas positive priming was noted in most sub-soils. This seems to be related to the composition of the mineral phase. I suggest that soil pH and competition between Al-SOM-complex and allophane formation is controlling stabilisation and destabilization of organic matter and Andisols
Lee, Jae Rock. "Étude et modélisation de l'endommagement des stratifiés carbone-époxy (± 45°)2s et (0°/90°)2s." Compiègne, 1985. http://www.theses.fr/1985COMPI207.
Banoukepa, Gilles de Roméo. "Electrodes en nanotubes de carbone pour l’optoélectronique organique." Limoges, 2010. http://aurore.unilim.fr/theses/nxfile/default/a3c331df-e597-4150-8b2c-71d539f4c041/blobholder:0/2010LIMO4073.pdf.
In this work, we have investigated the use of carbon nanotubes (CNTs) as a potential replacement for the ITO (indium tin oxide) electrode in organic optoelectronic devices namely organic light emitting diodes (OLEDs) and solar cells. We used different electrode preparation techniques depending on the type of characterization to be performed. In the first method, the CNT solution was filtered then used to fabricate films which were dried and annealed in a vacuum oven. The resulting films exhibit good optical and electrical characteristics. For morphological studies, we have developed a new characterization method using Raman spectroscopy which allowed us to quantify the metallic CNTs into the transparent film. Our study has shown that CNT-PEDOT:PSS nanocomposite films yield the best optoelectronic performance. Room temperature DC conductivity (σdc) of the single wall nanotube (SWNT)-based composite is 1 to 3 orders of magnitude higher than that of pristine PEDOT:PSS. To assess the performance of our optimized electrodes, with respect to electrical and optical characteristics in optoelectronic devices, we fabricated and characterized OLEDs. We demonstrated that the luminous efficiency is better than that of ITO-based devices and more suitable for flexible devices, which thus far proved to be a challenge with ITO
Maftuleac, Daniela. "Algorithme des complexes CAT (0) planaires et rectangulaires." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4032.
In this thesis, we study algorithmic problems in CAT(0) planar and rectangular complexes with an intrinsic l_2−metric. We present algorithms for some algorithmic problems, such as computing the shortest path and the convex hull of a finite set of points in CAT(0) planar and rectangular complexes. We present an efficient algorithm for answering two-point distance queries in a given CAT(0) rectangular complex K with n vertices. Namely, we show that for a CAT(0) rectangular complex K with n vertices, one can construct a data structure of size O(n^2) so that, given any two points in K, the shortest path can be computed in subliniar time of n. The second problem presented is computing shortest path from a single-source to the query point in a CAT(0) planar complex. We propose an algorithm which computes in O(n) time the shortest path between a given point and the query point in a CAT(0) planar complex with n vertices, using a given shortest path map and data structure of size O(n^2). Finally, we study the problem of computing the convex hull of a set of k points in a CAT(0) planar complex with n vertices. We describe an algorithm which computes the convex hull in O(n^2 + nk log k) time, using a data structure of size O(n^2 + k)
Tahiri, Vanessa-Laure. "Endommagement de stratifiés carbone/époxyde de types (0°/45°) et (+-45°) sous chargements quasi-statique et cyclique." Poitiers, 1995. http://www.theses.fr/1995POIT2314.
Escudié, Yannick. "Synthèse et réactivité d'espèces divalentes neutres du carbone : bis-ylures P,S cycliques et carbènes capto-datifs cycliques." Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2674/.
The present work concerns the development of new carbon(0) complexes. In particular, we aim at a synthetic route towards the first example of a mixed cyclic P,S bis-ylide. These ylides are expected to undergo unique reactivity thanks to the small cyclic structure. In the first chapter is described a bibliographic overview on carbon(0) chemistry. The focus on the electronic structure, applications as ligands in organometallic chemistry, and use as potential carbon atom sources. The second chapter, a synthetic route to access the dicationic precursor is described. This precursor yields after double deprotonation the desired P,S bis-ylide. The third chapter deals with the analysis of the crystallographic and theoretical data of the cyclic P,S bis-ylide and also the study of its reactivity. Reactions with carbonyl species demonstrate an increased reactivity as compared to its linear analogue and present new opportunities for the atomic carbon functionalization. Furthermore, a coordination study of the bis-ylide with various transition metals was performed in order to compare its properties with other C(0) complexes. The last chapter describes the synthesis of new azavinylidenesphosphoranes. There, we study the influence of the substituents on the carbene center with regard to reactivity and stability. These rare examples of cyclic push-pull carbenes possess a small singlet/triplet gap and transient carbenes reactivity. Moreover, their cyclic structure allow them to behave as ligand for transition metals. The corresponding complexes are robust and feature promising reactivity
Calbo, Sébastien. "Role du squelette carbone du peptide antigenique dans l'interaction avec les molecules du complexe majeur d'histocompatibilite et dans la degenerescence de la reconnaissance t : immunologie." Paris 5, 1998. http://www.theses.fr/1998PA05N141.
Monnier, Batto Anne-Françoise. "Relation Métabolisme Central Carboné et réplication de l’ADN : vers l’identification d’un réseau complexe de communication chez la bactérie Bacillus subtilis." Rouen, 2009. http://www.theses.fr/2009ROUES005.
To survive and to grow in optimal fashion, cells have developed systems of regulation which allow to adjust the activity of principal biological functions (replication, transcription and translation) to the richness of the environment (Bremer et Dennis 1987). In this thesis, we are interested about the regulation of replication in the bacteria Bacillus subtilis. The actors and the mechanisms of this regulation are unknown. But, in Bacillus subtilis, we identified some possible signalization pathways: the bottom of glycolysis and certain replication enzymes (Jannière et al. 2007, PLoS ONE. 2 :e447) and we showed that the link between the central carbon metabolism and replication is independent of the ppGpp. In parallel, we have developed a new method for studying the DNA replication. This method, which is based on imaging using a NanoSIMS 50, allows the detection and the precise quantification of combed DNA. This method promises to give new insight into the interactions of the link between CCM and replication
Lagerge, Serge. "Etude thermodynamique du mécanisme d'adsorption du complexe aurocyanure de potassium sur différents supports carbonés." Montpellier 2, 1995. http://www.theses.fr/1995MON20251.
Reynaud, Sébastien. "Modélisation hybride du canal radiomobile en environnement indoor complexe : application aux systèmes sans fil." Limoges, 2006. http://aurore.unilim.fr/theses/nxfile/default/b4f6d9b0-26aa-432b-96fa-753d42ce5000/blobholder:0/2006LIMO0020.pdf.
Nowadays, an increasing interest is devoted to wide-band applications like Wireless Local Area Networks (WLANs), because the present multimedia services require more high bit rate and thus large bandwidth. These needs in bandwidth involve important rise in frequency. At such frequencies and in an indoor propagation context, several objects neglicted in the channel modelisation (objects of wavelength size or with complex shapes), can disturb signal transmission. Recently, ray tracing techniques (RT), associated to the Uniform Theory of Diffraction (UTD), have emerged as the dominant techniques to predict the wide-band channel behaviour. Indeed, these asymptotic methods are fast and not limited in frequency. However, dealing with INDOOR propagation, this classical approach is not sufficient to model object of wavelength size or with complex shapes. For these structures, rigorous methods like the FDTD, consisting in solving Maxwell's equations in discrete time domain, are well-suitable. This subject deals with the elaboration of a hybrid method, combining the advantages of the UTD and the FDTD methods. On the one hand, the RT technique is used to model the wave propagation in rooms and buildings including large objects compared to wavelength. On the other hand, the furniture with small size or complex shape will be modeled by FDTD. The final goal is to determine which accuracy level of description of the environment we have to choose to get a good electromagnetic representation of the studied scene. In global terms, this subject deals with the bringing of a deterministic channel modelisation in systems' simulations
Conan, Françoise. "Contribution à l'élaboration de nouveaux squelettes organiques via l'étude de la réactivité d'un groupe disulfure de carbone coordine au molybdène." Brest, 1988. http://www.theses.fr/1988BRES2017.
Marie, Guillaume. "Modélisation du bilan carboné et hydrique d’une forêt méditerranéenne à structure complexe : de l'année au siècle." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4336.
The carbon balance of forest ecosystems involves many complex processes. At larger scales, ecological processes can not be modelled in a simplified way, but these have not been clearly identified. Furthermore, the development of mixed forest is increasingly promoted and this type of stand has additional degrees of complexity. On the one hand, complex canopy structure is likely to influence carbon fluxes, and other coexisting species may respond differently to climate change. Font-Blanche forest is an original case study that has not been studied in modelling because of its heterogeneity. In add, climate models predict significant reductions in rainfall during the 21st century for the Mediterranean region; But the century time scale maybe very demanding in computation time if ones want to taking into account the canopy structure. Then in this thesis we are modified a 3D mechanistic forest ecosystem model (noTG) to extend its temporal scale from year to century, thanks to meta-modelling technique. The meta-modelling gives good results and we used the meta-modeled version of noTG (notgmeta) to predict carbon and water balance of Font-blanche forest between 2008-2100 according to differents climate change scenario. According to model simplification, we find that photosynthesis, soil respiration and plant respiration are stimulated until 2100 with a decrease of this stimulation at the end of the simulation. We find that spatial representation of canopy and feedback effect of the water balance plays an important role and can not be simplified in the long-term simulation since the dynamics of species represents the largest source of carbon balance variations
Milone, Emmanuel. "Ablation physico-chimique d’un composite «fibres de carbone – résine phénolique» sous impacts de gouttes d’alumine." Limoges, 2009. https://aurore.unilim.fr/theses/nxfile/default/67a1a768-c649-4a3e-bef9-610d6e23bd5f/blobholder:0/2009LIMO4060.pdf.
During solid-fuel booster launching, a high velocity (= 2500 m/s) and temperature (> 3000 K) flow containing alumina droplets strongly stresses the motor's nozzle. The nozzle walls made of ablative composites are damaged by droplets successive impacts resulting from propellant combustion. This work comes within the framework of nozzle design and is focused on the global process study of ablative composite damage which is submit to repeated alumina droplets impacts and the measure of composite recession speed as a function of liquid particles parameters (temperature, velocity. . . ). In conclusion, this study suggest an ablation mechanism for the composite and allows the determination of the main droplet parameters on material ablation speed
Michelet, Lorraine. "Le complexe taeniase/cysticercose : la phylogénie et l’évolution de Taenia solium et la biologie moléculaire appliquée au diagnostic." Limoges, 2010. https://aurore.unilim.fr/theses/nxfile/default/67113046-9bb2-4ac3-8a95-62ac31f34981/blobholder:0/2010LIMO310I.pdf.
Taenia soliumis responsible for two distinct diseases in humans: taeniasis and cysticercosis. The complex Taeniasis/Cysticercosis has long been investigated because of the impact of the parasite on the human and pig populations. We wanted to study this complex from the angle of the parasite-host system (intermediate host, definitive host and parasite). The main objective of this work is to deepen knowledge of this complex to lead to improved diagnosis of neurocysticercosis. We work primarily on the genetic variation of Taenia solium in different countries: Madagascar, Cameroon and Mexico. We have confirmed the existence of two genotypes that reflect the particular biogeography of T. Solium. We have determined the specific nucleotide signatures allowing their distinction. We then have estimated the dates of divergence of these groups to establish the biogeographical origin of the parasite, particularly in Madagascar. The observations from T. Solium were correlated with historical, genetic and archaeological data. We then expanded our study to two other Taenia that infect humans: T. Saginata and T. Asiatica. The origin of these parasites in humans has been studied as well as the events leading to host’s switching. We have issued several hypotheses about the major events of diversification of these parasites. Specifically, we examined their relationship with their hosts and the influence they had on the current status of these three Taenia. The second aspect of this work focuses on the diagnosis of neurocysticercosis. The research was conducted on a Mexican population where cysticercosis is endemic. We compared all biological tests currently available: ELISA for the detection of antibodies, ELISA for the detection of antigen, EITB and PCR. These data were compared with clinical, epidemiologic and imaging information. We determined the intrinsic parameters (specificity and sensitivity) of each method and the correlation between the different tests. We have also studied the effect of CSF inflammation on test results. We propose to incorporate the PCR as a diagnostic tool for neurocysticercosis in combination with others tests
Marzouk, Jaouad. "Développement de couches planaires à base de nanotubes de carbone pour des applications en optoélectronique." Limoges, 2013. http://aurore.unilim.fr/theses/nxfile/default/261c3a25-e1a1-46c5-9cba-eff1038d34e3/blobholder:0/2013LIMO4002.pdf.
This work aims at developing conjugated polymer/carbon nanotubes (CNT) composites and studying their electrical properties. Thanks to their structure and electronic configuration, carbon nanotubes are indeed found to be very promising to improve the charge transport properties of active layers based on organic semi-conductors such as polymers. However, it is necessary to control their structuration within the matrix, in order to demonstrate functional components with improved performance. In this context, we propose a simple fabrication process, realized in ambient conditions and compatible with low cost technologies, to achieve planar inter-digitized architectures based on polymer/CNT composites. By using a specific procedure for the alignment of carbon nanotubes under an electric field, this strategy allows us to control the charge transport properties of the composites by varying the various experimental conditions used during their fabrication (composition of the composite, nature of the solvent used, nature of the electric signal used for the orientation of the CNT). The analysis of the angular distributions of the incorporated nanotubes with regard to the direction of orientation electric field allowed the optimization of the processing conditions, towards optimal electric performance. Then, the electric characterization of the planar devices showed that the incorporation and orientation of CNT within the polymer matrix (P3HT in our case) do not drastically modify the charge transport mechanisms occurring in the polymer. Finally, we illustrate the potentialities of the approach by implementing organic filed effect transistors based on the P3HT/CNT composites. The optimal fabrication conditions were associated with a strong improvement of the associated charge mobility by two orders of magnitude with regard to the pristine polymer matrix. These results demonstrate the strong potentialities associated with polymer/CNT composites in the field of organic optoelectronics, and open various perspectives in related areas such as radiofrequency communications or nonlinear optics
Vergne, Bruno. "Mise en forme de composites nanotubes de carbone/alumine et modélisation de leur conductivité thermique." Limoges, 2007. https://aurore.unilim.fr/theses/nxfile/default/a8757fd1-fa58-4fb7-aa6b-b7e8f1f46286/blobholder:0/2007LIMO4032.pdf.
Due to the very high thermal conductivity and aspect ratio of Carbon NanoTubes (CNT), their introduction in alumina matrices, even in low amounts, is expected to improve the thermal conductivity of the resulting composites. Such composites could then be used to manufacture thermal sinks for high power electronic circuits, provided that the coefficient of thermal expansion keeps a value close to that of alumina in order to get an intimate contact between the substrate and its sink. Researches on the formulation of alumina/CNT suspensions were carried out and led, after shaping and sintering, to quite homogeneous composites. In comparison with pure alumina, although a great improvement of the electrical conductivity of composites was recorded as early as a few vol. % of CNT were added, an opposite trend was observed for the thermal conductivity. We showed that the decrease of the thermal conductivity can not be caused only by the lowering of the relative density of the material. The refinement of simple computing model, taking into account the thermal resistances at the CNT/matrix and CNT/CNT interfaces, allowed to predict almost quantitatively this thermal conductivity loss
Le, Pape Hélène. "Etude des propriétés germicides de fibres de carbone activé : Application à la décontamination de l'air en cabine d'avion." Limoges, 2003. http://aurore.unilim.fr/theses/nxfile/default/e49e0312-5d6a-4b89-9a88-e54f8110c73f/blobholder:0/2003LIMO0065.pdf.
Benslimane, Chouki. "Étude physiologique de Streptomyces ambofaciens producteur de la spiramycine en milieu complexe : effet de la source de carbone sur la consommation des acides aminés et des acylglycérols." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL126N.
Poor, Kalhor Mahboubeh. "Étude DFT du mécanisme de formation du dimethyl carbonate à partir de CO2 et de CH3OH à l'aide de Me2Sn(OMe)2." Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10325.
Carbon dioxide occupies a special place in the amplification of the anthropogenic greenhouse effect. In particular, its use in the synthesis of organic carbonates from alcohols, constitute an alternative to the current application of phosgene or carbon monoxide. The insertion of CO2 into the Sn-OCH3 bond of dialkyldimethoxystannanes is recognized as the first step to dimethyl carbonate (DMC) formation from methanol and carbon dioxide. The identification of the subsequent steps is crucial for activity improvements and is still under debate as the tin species have the propensity for oligomerization. We have used density functional theory calculations to provide insight into the reaction mechanism. The CO2 insertion into the Sn-OCH3 bond is promoted by the concerted Lewis acid-base interaction of CO2 with tin and the oxygen atom of the methoxy ligand. The major reaction pathway to DMC is proposed to occur via an intramolecular rearrangement of the monomeric species, Me2Sn[OC(O)OCH3]2. The process results in the transfer of a methyl group from one methyl carbonate to the other via a 4-membered or 6-membered ring forming the Sn-CO3 moiety. In a second stage, methanol reacts with one intermediate and leads to DMC formation and a trimer compound which may allow the regeneration of the reactant. Also a decanuclear tin complex is produced due to the lateral reaction. Finally a catalytic cycle for DMC production in methanol can be elaborated. DFT calculations are in agreement with the experimental data and allow a comparative analysis of reaction channels
BHUGUN, IQBAL. "Catalyse de la reduction electrochimique du dioxyde de carbone par les porphyrines de fer(0). Effet synergique des acides de bronsted et de lewis." Paris 7, 1995. http://www.theses.fr/1995PA077102.
Lautrette, Sophie. "Utilisation des fibres de carbone activé comme catalyseurs de O- et N-glycosylation : Application à la synthèse d'analogues de saponines et de nucléosides." Limoges, 2004. http://aurore.unilim.fr/theses/nxfile/default/ecae3fa8-c345-4d91-900a-d5b7ff30cfdf/blobholder:0/2004LIMO0038.pdf.
Activated Carbon Fibers (ACF) constitute a new class of activated carbon widely used for air or waste water treatment. Owing to their microporous structure and to their highly acidic characteristic, we were interested in applying them for the first time as acidic promoter in organic synthesis, notably for solvent free O- and Nglycosylation reactions. The goal of this work is to show the ability of ACF to replace harmful classical acidic catalysts (e. G. Lewis acid). On the basis of ACF characterization (determination of surface area by the Brunauer Emmett and Teller (BET) method, microporous volume by the Dubinin-Radushkevich equation, the surface acidity by Boehm methodology…) and studies on O- and N-glycosylation (effect of reactant concentrations, effect of reaction time and temperature, effect of the kind of reactant) hypothetic mechanisms are proposed, notably for the synthesis of saponin and nucleoside analogues
Larcher, Nicolas. "Contribution à la caractérisation des matériaux au comportement viscoélastique par méthode ultrasonore : application aux matériaux bitumineux." Limoges, 2014. https://aurore.unilim.fr/theses/nxfile/default/4c5e3d35-135f-4f27-ba5b-d15f37e910cf/blobholder:0/2014LIMO4006.pdf.
This work deals with a laboratory test applied to the thermo viscoelastic materials in particular the bituminous materials. Today, the mechanical characterization of the bituminous materials is very expensive in time, material and equipment. The aim of this study is to propose an alternative to the mechanical test by a Non Destructive Test (NDT) based on ultrasonic wave measurements. The materials of this study, a binder and two asphalt concretes, have been developed by Eiffage Travaux Publics company. These asphalt concretes are otherwise to improve the mechanical properties by an optimization the granular skeleton of the bituminous materials. This study focuses to the different methods of determination of the acoustic parameters like velocity and attenuation factor. Moreover, their frequency dependence is highlighted. Experimental data, obtained with the standard mechanical modulus test, have been taking into account as the reference and plotted in term of master curves and complex representations as Cole – Cole and Black spaces. A rheological model (2S2P1D) which has a continuum spectrum, is fitted to the mechanical representation. The ultrasonic characterization of the materials is based on two aspects : on one side the determination of phase velocity and attenuation factor of compression and shear waves, on the other side the theory of 2D wave propagation in elastic and viscoelastic medium which allows to determining mechanical properties (G*, E*, v*). A good agreement is showed between the ultrasonic data, the mechanical characterization and the rheological prediction. The complex representations which are based on the expression of real and imaginary parts of the complex modulus and the phase angle, are the major contribution of the hypothesis of wave propagation in a viscoelastic medium for the utilization
Pietri, Nathalie. "Photochimie en matrices de gaz rares : caractérisation et réactivité du complexe C3O2:HCl et de ses précurseurs. Etude par spectroscopie IR-TF et modélisation théorique." Aix-Marseille 1, 1996. http://www.theses.fr/1996AIX11054.
Lapoux, Valérie. "Etude des diffusions elastiques de faisceaux radioactifs de #1#0#,#1#1be et #6he sur des cibles de protons et carbone aux energies du ganil." Paris 11, 1998. http://www.theses.fr/1998PA112336.
Iraqi, Ahmed. "Nouveaux complexes d**(0)-d**(8) zirconium(iv)-rhodium(i) catalyseurs d'hydroformylation des olefines : composes hydrures et composes cationiques." Toulouse 3, 1988. http://www.theses.fr/1988TOU30055.
Lisena, Jérôme. "Nouveaux complexes pince indényle et indolyle de palladium : préparation et réactivité." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2013/.
The aim of this thesis is to develop and study a new family of pincer complexes based on indene and indole skeletons. In recent years, pincer complexes commanded much attention in the field of organometallic chemistry. Many important applications and properties were discovered and this contributes to the dynamic in the development of new pincer structures. The first chapter presents a bibliographic introduction of pincer complexes, the principal way of preparation and some original applications (catalysis, high reactive compound stabilization, mechanistic studies). Then, the development of the indenyl pincer complexes in the LBPB group of the LHFA is introduced. The second chapter contains the synthesis of SCS indenyl and indenylidene palladium (II) complexes. A mechanistic study of the formation of these complexes shows that the Csp3-H bond is activated preferentially compared to the Csp2-H bond. Therefore, a methyl substituted ligand is prepared in order to block the pathway of Csp3-H bond activation. It demonstrates the feasibility of the direct activation of the central Csp2-H with subsequent formation of a methylindenyl palladium complex. In the third chapter, a new ligand structure is developed starting from the indole skeleton. This new pro-ligand completes the serie of indenyl, indolyl and indenylidene complexes, which exhibit a range of different structural and electronic properties. Finally, the non-innocent character of this new complex is studied and proves the inertia of the lone pair of the nitrogen. In the last chapter, the influences of the three platforms are compared from a structural point of view, in all cases with the PPh3 co-ligand. The electronic properties are examined using carbon monoxide as spectroscopic probe. Hydroamination of acrylonitrile and allylation of imine are then carried out to distinguish the systems according to their electronic properties and their mechanism
Goudalle, Sébastien. "Intensification du procédé de vaporeformage à travers la réalisation d’un échangeur-réacteur céramique à architecture 3D complexe fonctionnalisé à l’aide de catalyseurs spécifiquement optimisés." Limoges, 2011. https://aurore.unilim.fr/theses/nxfile/default/49056802-ae37-4fc7-b376-92b1e197bd56/blobholder:0/2011LIMO4062.pdf.
This work aims to elaborate a ceramic plate heat exchanger-reactor designed to intensify the steam methane reforming (SMR) process. A thermodynamic study first shows that 4 oxides (Al₂O₃, Y₃Al₅O₁₂, Al₂TiO₅, MgAl₂O₄) are stable in SMR conditions. Alumina is then chosen for the fabrication of the exchanger-reactor body for technicoeconomical reasons. Due to the complex design of the exchanger-reactor, its fabrication is conducted in two stages: (i) the fabrication of the reactor plates and (ii) the joining of plates to get gas-tight elementary modules. A stereolithography process is optimized for the shaping of reactor plates as large as 350x120x1,6 mm³. Theses plates are then joined following two original routes that rely on the intercalation of an alumina tape casted band in between green or sintered plates. An elementary module made of 5 plates is thus fabricated confirming the feasibility. The SMR process requires the functionalization of the exchanger-reactor with catalysts. In an exchanger-reactor, the contact time of reactant molecules on the catalyst is very short (roughly a hundred of milliseconds), so that it requires specifically designed catalysts. Rh/MgAl2O4 catalysts are synthesized in this aim through a route inspired by the sol-gel one. We show that the ultradivided structure of those catalysts in extremely stable in operating conditions which suggests high potential performances
Watfa, Diana. "Supercurrent and dynamics in carbon nanotube Josephson Junction in the Kondo regime." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP015.
During this thesis, we have studied the competition between two many-body effects: the Kondo effect, which is the screening of a localized magnetic moment by the conduction electrons of a conductor, and proximity induced superconductivity. The competition between these two effects has been already investigated at equilibrium, by monitoring the current phase relation of carbon nanotube-based Josephson junctions. These experiments have revealed phase and gate dependent quantum transitions between the magnetic doublet state and the Kondo screened singlet non-magnetic state of the nanotube. In the present work we show that this transition can be dynamically induced by exploring the AC Josephson emission. The AC Josephson emission can be measured by coupling the carbon nanotube to an on-chip quantum detector via a resonant coupling circuit. Experimental results show that this emission is strikingly reduced in the gate region where the critical current is enhanced due to the interplay of the Kondo effect and superconducting proximity effect. By comparing our data to numerical renormalization group calculations, we showed that the collapse of AC Josephson emission is due to the dynamics of quasiparticle in the quantum dot which induce a transition between a singlet ground state and a doublet excited state.To improve our detection methods at low temperatures, we performed two other experiments. In the first experiment, we have tested new homemade filtering of DC lines in a cryo-free dilution refrigerator, by measuring the electronic temperature of a single electron transistor. In the second experiment, we have designed and measured a new type of superconducting micro-resonator, based on a high kinetic inductance material, namely tungsten nanowiresdeposited using a helium focus ion beam. This kind of resonator can be very useful to improve the resonant coupling for on-chip detection and more generally to engineer a compact non-linear high impedance superconducting element for quantum electronics
Gaudin, Jean-Marc. "Synthèses sélectives à l'aide de complexes du Palladium(0) : élaboration de chaine latérale de stéroïde (glaucastérol), phéromones et alpha-amino esters d'intérêts biologiques." Paris 6, 1986. http://www.theses.fr/1986PA066536.
Alnagi, Omar. "Reaction de la trimethylphosphine sur les sels de cobalt (ii) : synthese des complexes pentacoordonnes cox::(2)(pme::(3))::(3) (x=c1**(-), br**(-), i**(-), ncs**(-), no::(2)**(-)), reactivite vis-a-vis de petites molecules co, no et o::(2)." Toulouse 3, 1987. http://www.theses.fr/1987TOU30048.
Casellas-Français, Magali. "Mise en oeuvre, modélisation, optimisation et contrôle d'un procédé discontinu séquentiel (SBR) : application au traitement du carbone, de l'azote, du phosphore et des matières en suspension d'eaux résiduaires urbaines." Limoges, 2002. https://aurore.unilim.fr/theses/nxfile/default/c7b8b1be-7f59-4700-ba14-86cff384c513/blobholder:0/2002LIMO0035.pdf.
Wastewater treatment optimization requires the installation of reliable processes and a control of operating conditions. In this context, discontinuous processes like SBR, working on the principle of alternating reaction, settling and purge phases is investigated. A development process methodology based on the use of mathematical simulations, lab scale experiments, full scale extrapolation and simple but robust control strategies is reported. The Benchmark of wastewater treatment associates a wastewater treatment model (ASM n°1 ofHENZE et al. , 1986) and a settling conditions model (TACKACS et al. , 1991). Combining both models allows for the simulation of an activated sludge process operation. An exhaustive bibliographic study could highlight different scenarios of SBR operations able to achieve carbon, nitrogen, phosphorus and total suspended solids removal. Different time delays were investigated in order to identify two particular operating conditions : short cycles and long cycles. The use of the Benchmark associated with a critical identification of incoming variables of the model, was extended to the development of strategies for nitrogen removal improvement. This study, combined with an experimental study of phosphorus removal allowed to define a 24 hours cycle, improving denitrification rates but also highlighting problems related to temporal variations of incoming load. In order to solve this problem, a special procedure , based on the use of three sensors : pH, ORP, dissolved oxygen, was investigated and full scale commissioned, in order to control with accuracy operating conditions
Orlianges, Jean-Christophe. "Optimisation du dépôt par ablation laser de films minces d'alumine et de carbone tétraedrique amorphe pur et dopé : propriété des couches et intégration dans la fabrication de composants MEMS RF." Limoges, 2003. http://aurore.unilim.fr/theses/nxfile/default/adf9ac52-17e8-4476-98bb-50098b522ec8/blobholder:0/2003LIMO0032.pdf.
The fist part of this work is devoted to the pulsed laser deposition process. We propose solutions for the two main problems of PLD : the jection of micron-sized particles and the non uniformity of film thickness profile. In the second part, we study the properties of alumina and pure and doped tetrahedral amorphous carbon deposited by laser ablation under high vacuum and at room temperature. In the last part, we present the insertion of these two materials in radio frequency micro electro mechanical system