Tesis sobre el tema "Avancée de la banquise"
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Angora, Ette Alain. "Système d'alerte avancée des crises bancaires : une approche fondée sur les modèles multinomiaux". Limoges, 2009. http://aurore.unilim.fr/theses/nxfile/default/91e1401e-5970-495f-b8c5-933f2f7484ce/blobholder:0/2009LIMO1003.pdf.
Texto completoThis thesis is an extension of Early Warning Systems of banking crises based on an econometric multinomial logit approach. The aim of the thesis is twofold : in the first part we analyse the concept , determinants and the theorical foundations of the banking crises in a general context. Therefor, we define an analytical frame work,for the implementation of a policy of crisis prevention. In the second part, building on this framework we provide a technical contribution to the prediction of banking crises. The originality of the thesis lies in use of the multinomial logit models as a tool for predicting banking crises. Starting from two empirical studies, we highlight three major results : first, we show that taking into account the specificities of banks in terms of accounting ratios improves the prediction of banking crises. Secondly, we detect the presence of a bias in the identification of crises. This bias is revealed when one takes into account the periods before or after a period of crisis. Thirdly, we propose a frame work of monitoring the banking system which consists in assigning scores to the level of fragility. We show that the most severe banking crises that havce occured in Brazil and Mexico in1994 , and in South asia in 1997, follow periods of very high fragility
El, Sayad Ismail. "Une représentation visuelle avancée pour l'apprentissage sémantique dans les bases d'images". Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2011. http://tel.archives-ouvertes.fr/tel-00666531.
Texto completoHimmich, Kenza. "Antarctic sea ice : a seasonal perspective". Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS105.
Texto completoAntarctic sea ice has undergone an abrupt reduction in 2016, following more than four decades of a slow increase. This could have wide-ranging consequences given the importance of Antarctic sea ice for climate, ocean, and local ecosystem. Yet, climate models fail to capture this observed evolution, leaving considerable uncertainty regarding its origin, impacts and future evolution. Models failure relates, but not only, to a poor understanding of fundamental Antarctic sea ice processes. In this thesis, we contribute to progress understanding of Antarctic sea ice, adopting a seasonal perspective. We investigate the drivers of seasonal sea ice edge advance and retreat, analyzing the roles of thermodynamic preconditioning, air-ice-sea heat fluxes and sea ice dynamics. We show that, in the mean state, timings of ice edge advance and retreat are largely controlled by thermodynamics, via preconditioning from mixed layer heat content and sea ice thickness, respectively. Variations in air-ice-sea heat fluxes and sea ice dynamics have a significant but secondary importance. This conclusion is supported by a simple thermodynamic model, observational analyses and the NEMO ice-ocean model. We also show that recent changes in sea ice seasonality are mainly driven by thermodynamics, similar to the mean state. The reduction in Antarctic sea ice following 2016 coincides with nearly circumpolar earlier retreat and later advance of the ice edge. Our analysis links these changes to thinner ice in winter, faster melt in spring and warmer upper ocean in summer, in line with ice-albedo feedback processes. Based on the circumpolar footprint of these changes, we argue that they likely have an oceanic origin
Machrouh, Fouad. "Vers un système d' alerte avancée des crises bancaires : le cas des pays émergents d'Asie et d'Amérique latine". Limoges, 2008. http://www.theses.fr/2008LIMO1011.
Texto completoThe objective of this thesis is to present an early warning system to the banking crisis. The empirical application covers the Latin America and the Asian regions. Such a contribution is more crucial that these crisis occured more frequently and that the prices for resolving theme are higher. This thesis is organised in three chapters. In the first chapter, we examined the various ways to tackle the banking crisis. We highlighted the inefficiency of management crisis measures, then, we underlined the limits of the prevention measures, finally, we noticed the absence of an early warning system for crisis in emerging countries and we stressed the modalities of possible applications. In chapter 2 and 3, we tried to develop an early warning system based in the use of unvaried and multivaried methods. Three principal results came out. First, Asian and Latin America banking crisis are best predicted when banking, macroeconomic and institutional variables are considering together. Second, one year lagged variables predict the banking crisis better than two or three years lagged variables. Finally, certain variables show a regular significant for both methods : unvaried analysis and multivaried analysis ones such as the growth rate of real GDP, the Gross private capital flows to GDP, the reverses on nonperforming loans reported on the total asset and the return on asset
Boutin, Guillaume. "Interactions vagues-banquise en zones polaires". Thesis, Brest, 2018. http://www.theses.fr/2018BRES0050/document.
Texto completoSea ice, which covers most of the ocean near the poles, is a key component of the climate system. Global warming is driving its massive melting, especially in the Arctic. Where sea ice cover decreases, fetch increases leading to more energetic sea states. This means potentially enhanced wavesice interactions effects in the future. The quick evolution of sea ice extent and volume combined with the intensification of human activities in polar regions urge us to improve our understanding of waves-ice interactions.Sea ice attenuates waves. They can however propagate through it and break it far into the ice cover. Attenuation depends on ice properties such as floe size, thickness, etc. Once broken, resulting floes are more likely to drift and melt. In addition, wave attenuation yields a force which pushes the floes in the direction of wave propagation.A simplified representation of sea ice, including a floe size distribution, has been incorporated in a wave model.It allows us to show the important contribution of dissipative mechanisms in the wave attenuation, especially those induced by the bending of the ice plates. After validation, the modified wave model is coupled to an ice model. The floe size distribution is exchanged in the coupled framework and used in ice lateral melt computation. The force exerted by the waves on the ice floes is sent from the wave model and is shown to compact sea ice in summer. This reduces the melting and significantly increases the temperature and salinity in the surface ocean close to the ice edge
Garric, Gilles. "Simulation couplée globale : atmosphère, banquise et océan superficiel". Toulouse 3, 1996. http://www.theses.fr/1996TOU30241.
Texto completoLebrun, Marion. "De l'interaction entre banquise, lumière et phytoplancton arctique". Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS524.
Texto completoLarge weaknesses remain considering our understanding of the drivers of phytoplankton growth in Arctic sea ice zone, especially due to large uncertainties in the interactions between sea ice, light and phytoplankton.The aim of this PhD thesis is to better understand these interactions and to highlight the main uncertainties considering these interactions in Earth System Models. I first show that the ice-free period is mainly led by the solar irradiance cycle and by the ocean-atmosphere thermodynamic exchanges during summer. It is consequently projected to extend into fall in the future. Then, I evaluate the radiative transfer scheme in the ocean model NEMO, in arctic sea ice zone. I show that NEMO largely underestimates the transmitted shortwave radiation in ice-covered waters, especially due to the overestimation of the snow and the first level of the ocean attenuation. I finally define a diagnostic to describe available light seasonality in the sea ice zone and I study the impact of this diagnostic on simulated phytoplankton in the bio-geochemistry model PISCES. However, large uncertainties remain in the study of the relation between this diagnostic and the phytoplankton growth. This is especially due to the non-linearity between available light and phytoplankton growth and also due to the lake of knowledge about the phytoplankton physiology
Djim, Ngangbaye Minaingar. "Les banques nationales de développement des pays les moins avancés du Sahel : essai d'analyse de leur contribution au développement". Nice, 1989. http://www.theses.fr/1989NICE0005.
Texto completoGirard, Lucas. "Vers un nouveau cadre de modélisation rhéologique de la banquise". Phd thesis, Grenoble, 2010. http://www.theses.fr/2010GRENU021.
Texto completoIn this thesis, new approaches are used to model the mechanical behavior of sea ice and to evaluate sea ice models in terms of ice drift and deformation. It is first shown how the statistical and scaling properties of sea ice drift and deformation can be used as an evaluation metric for sea ice models. These properties are known to play an important role regarding ice growth estimates and should therefore be captured in sea ice models. The evaluation metric is applied to simulations performed with a coupled ocean/sea ice model, where the mechanical behavior of sea ice is represented using the Viscous-Plastic (VP) rheology, as in most current global ocean and climate models. The VP model is shown to be unable to capture the statistical and scaling properties of sea ice deformation. As these properties are a signature of the ice mechanical behavior, it suggests that the VP rheology is inappropriate for sea ice modeling. The new mechanical model developped during this thesis is based on the hyopthesis that sea ice deformation is mainly accommodated by fracturing and frictional sliding (brittle behavior) over a wide range of scales (stresses can be transmitted on long distances). The main characteristics of this new model, named the Elasto-Brittle (EB) rheology, are progressive damage to represent the brittle behavior, and an elastic constitutive law to allow long-range elastic interactions to take place. The EB rheology is first used to carry out a fundamental study of fracture in heterogeneous media. Simulations show that fracture is preceded by a divergence of the correlation length, measured from a correlation analysis of discrete events and from a scaling analysis of the continuous strain-rate field. The scaling properties of deformation that emerge in the vicinity of failure ressemble those observed for the brittle deformation of geophysical objects such as sea ice or the earth's crust. These results, that argue for a critical point interpretation of fracture, are discussed in the context of fracture at geophysical scales. Secondly, short term simulations of the winter Arctic sea ice cover are carried out using the EB rheology. The results show that the EB rheology captures well the statistical and scaling properties of sea ice deformation, motivating the implementation of the EB rheology in global sea ice models. On longer time scales, sea ice can recover its mechanical properties through refreezing of fractures. A healing law accounting for this process is presented along with preliminary results from simulations accounting for the effect of healing. Finally, a methodology for the implementation of the EB rheology within a global sea ice model is presented and discussed
Derien, Anthony. "Solvabilité 2 : une réelle avancée ?" Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00733700.
Texto completoGaudette, Étienne. "Indices macroéconomiques avancés basés sur l'Enquête sur les perspectives des entreprises de la Banque du Canada". Mémoire, Université de Sherbrooke, 2007. http://savoirs.usherbrooke.ca/handle/11143/307.
Texto completoVerin, Gauthier. "Propriétés physiques et optiques du manteau neigeux sur la banquise arctique". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAU010/document.
Texto completoThe Arctic ocean shows a very strong seasonality trough the permanent presence of sea ice whose extent varies from 6 to 15 millions km2. As an interface, sea ice limits ocean - atmosphere interactions and impacts the global energy budget by reflecting most of the short-wave incoming radiations. The snow cover, at the surface, is a key element contributing to the optical properties of sea ice. Snow enhances further the surface albedo and thus delays the onset of the ice melt. In addition, snow is the main responsible for the vertical light extinction in sea ice. However, after the polar night, this low light transmitted to the water column is a limiting factor for primary production at the base of the oceanic food web. The snow cover, through the temporal evolution of its physical properties, plays a key role controlling the magnitude and the timing of the phytoplanktonic bloom. In the actual global warming context, sea ice undergoes radical changes including summer extent reduction, thinning and shifts in snow thickness, all of which already alter Arctic primary production on a regional and global scale.This PhD thesis aims to better constrain the snow cover contributions to the radiative transfer of sea ice and its impact on Arctic primary production. It is based on a dataset collected during two sampling campaigns on landfast sea ice. Physical properties of snow such as snow specific surface area (SSA) and density allow a precise modeling of the radiative transfer which is then validated by optical measurements including albedo, transmittance through sea ice and vertical profiles of irradiance in the snow.During the melt season, marine snow which shows strong spatial heterogeneity evolves fol- lowing four distinctive phases. The melting, which first appears at the surface and gradually propagates to the entire snowpack, is characterized by a decrease in SSA from 25-60 m2kg-1 to less than 3 m2kg-1 resulting in a decrease in albedo and an increase in sea ice transmittance. This is a chaotic period, where optical properties show a very strong temporal variability induced by alternative episodes of surface melting and snowfalls. The physical properties of snow are used in a radiative transfer model in order to calculate albedo, transmittance through sea ice and vertical profiles of irradiance at all depths. The comparison between these simulations and measured vertical profiles of irradiance in snow highlights the presence of snow absorbing impurities which were subsequently qualitatively and quantitatively studied. In average, impurities were composed of 660 ngg-1 of mineral dust and 10 ngg-1 of black carbon. They were responsible for a two-fold reduction in light transmitted through sea ice. The light extinction, calculated at all depths in sea ice, and represented by isolums, was compared to the temporal evolution of ice algae biomass. The results show that every significant growth in ice algae population is related to an increase of light in the ice. These growths were observed even at very low light intensities of 0.4 uEm-2s-2. Light variations in the ice were linked by snow metamorphism and snow melting at the surface
Komatitsch, Dimitri. "Modélisation numérique avancée pour la géophysique". Habilitation à diriger des recherches, Université de Pau et des Pays de l'Adour, 2003. http://tel.archives-ouvertes.fr/tel-00006964.
Texto completoZhang, Xiao Hui. "Simulation avancée des circuits micro-ondes". Paris 12, 1989. http://www.theses.fr/1989PA120040.
Texto completoRochart, Guillaume. "Explications et programmation par contraintes avancée". Nantes, 2005. http://www.theses.fr/2005NANT2151.
Texto completoSoriot, Clément. "Caractérisation de la banquise Arctique à partir d'observations micro-ondes multi-satellites". Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS451.
Texto completoSea ice plays a major role in ocean circulation as well as in the climate and weather system. In the context of global warming, the extent of the Arctic sea ice has been decreasing steadily over the last 40 years and monitoring of the Arctic is essential. Microwave instruments on board satellites allow the study of this region of the Earth under all weather conditions, and regardless of the day/night cycle. Particularly suited over polar regions with high cloud cover and a six-month polar night, microwave satellite provide key observations for estimating geophysical parameters of the sea ice. Nevertheless, the understanding of the physics underlying the observed microwave signatures is still partial. This thesis aims at improving our understanding of the microwave signals of the sea ice and is part of the preparation of two upcoming Earth observation missions led by the European Space Agency: the Copernicus Imager Microwave Radiometer (CIMR) and the Copernicus Polar Ice and Snow Topography ALtimeter (CRISTAL). In a first part, the covariabilities of passive microwave signals, highlighted by an unsupervised classification technique, will be analyzed and interpreted jointly with active microwave signals, using a microwave radiative transfer model. The results showed that it is possible to identify specific behaviors of sea ice concentration and thickness, and snow structure. The importance of metamorphism within the snowpack for the interpretation of passive microwave signals was highlighted. In a second part, an algorithm for estimating sea ice thickness from passive microwave observations was developed using an artificial intelligence technique. The results were compared to in situ sea ice thickness measurements and also showed good performance compared to other satellite-based sea ice thickness products. By applying the algorithm to a long collection of intercalibrated satellite data, a time series of Arctic sea ice thickness was constructed between 1992 and 2020, making it the longest to date. A final section deals with microwave altimetry techniques for measuring geophysical parameters of the sea ice. The sensitivity of microwave altimetry waveforms to the thickness of the snow cover of the Arctic sea ice is analyzed
Gani, Sarah. "Analyse des processus physiques régissant les évolutions récentes de la banquise Arctique". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS377.
Texto completoIn the Arctic, the consequences of global warming are stronger than anywhere else on the planet : the increase in air temperature over the last two decades is more than twice the average increase, according to the latest IPCC report. The evolution of the ice pack is a prime example of these changes. We observe a significant decrease in sea ice cover, associated with a loss of volume in all seasons. The sea ice becomes younger, more breakable, and more mobile. These changes in sea ice have brought the Arctic into a new state where air/snow/ice/ocean interactions are altered and difficult to apprehend. More observations and efficient numerical models are required to better understand and predict these changes and to correctly simulate the interactions between sea ice and the other components that control the Arctic climate. In this climate change context, the objective of this thesis is to analyze observations mainly collected in winter by IAOOS -Ice Atmosphere Arctic Ocean Observing System- drifting buoys (equipped with SIMBAs -SAMS Ice Mass Balance for the Arctic-), to understand which processes determine the recent Arctic sea ice evolution. We confront these analyses with numerical simulations made from the one-dimensional ice and snow model LIM1D (Louvain-la-Neuve sea Ice Model)
Ben, cheikh Sondes. "Optimisation avancée au service du covoiturage dynamique". Thesis, Ecole centrale de Lille, 2016. http://www.theses.fr/2016ECLI0002/document.
Texto completoCarpooling is presented as an alternative transport solution that comes treat environmental image, economic and societal personal car. The dynamic carpooling problem is to develop real-time optimized touring vehicles to better respond to the instantaneous transport demands.Our work belongs within this context, where optimization and real time are the key words. Given the exponential complexity of the dynamic ridematching problem, we opt for the approximate methods to solve it. We present our first contribution by proposing a metaheuristic based on the multi-criteria tabu search. The proposed algorithm employs an explicit memory system and several searching strategies developed to avoid the entrapment by local solutions. Afterward, we introduce our second contribution which is in the form of an evolutionary approach supported by a dynamic coding and based on controlled genetic operators. However, the exponential complexity of the problem leads us to consider that a simple metaheuristics is not sufficient to solve effectively the problem of dynamic ridematching. It is with this in mind that we are unveiling our third solving methodology by developing an original evolutionary approach in which chromosomes are defined as autonomous and intelligent agents. Thanks to an accurate protocol negotiation, the Chromosomes Agents can control the genetic operators and guide search for finding optimal solutions within a reasonable period of time. With the prospect of a better combination between carpooling and other modes of transport, we design a system called DyCOS, integrating our approaches and applications dedicated to solving the problem of dynamic ridesharing
Borde, Yannick. "Gestion de la contamination en microélectronique avancée". Grenoble INPG, 2008. http://www.theses.fr/2008INPG0150.
Texto completoThe performance, the growth and the efficiency of a production line are related to its capacity to in the face of new contaminants. The contamination protocol must allow the introduction of potentially disturbing technologies while keeping the associated running costs as low as possible. Ln this thesis we provide a better understanding of contamination by taking the whole cycle into account and by investigating specific subjects with an innovative scientific approach which is applied to a to state of the art of micro and nano-electronics production line: seriousness study of metallic elements towards silicon and silicon oxide, transfer of contaminants via contact by solid objects or via gaseous phase. . . From the results contained in this thesis, the implementation of working rules have been established which are dedicated to the control of the contamination. These rules are consistent and founded from a sound scientific basis
Mathurin, Jérémie. "Nanospectroscopie infrarouge avancée : développements instrumentaux et applications". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS188/document.
Texto completoFor 10 years, near-field technologies applied to infrared spectroscopy have reached milestones and now are able to make analysis at nanoscale. In my PhD thesis, I will focus on one of these techniques: the so-called AFM-IR technique which combined an atomic force microscope (AFM) with a pulse laser tunable in the infrared spectral range.The main goal of my PhD thesis will be to present the last developments which appears for this technique such as resonance enhanced AFM-IR, tapping mode AFM-IR or the first measurements of AFM-IR with broadband sources. These developments are major in the field of the technique and have led to high increase of the numbers of users. However, AFM-IR remains a recent and complicated technique where user has to master in the same time atomic force microscopy and infrared spectroscopy.The last technological developments allow measurements at the nanoscale. This has multiple consequences, especially it opens new applications fields. It also generates new problematic and new experimental challenges. As a consequence, it is necessary to understand new technological limitations created by these new developments in order to stay critical of the results obtained with an AFM-IR measurement and avoid analysis and interpretation errors which can have bad consequences on the different fields of study
Castelbajac, Côme de. "Surveillance avancée et amélioration du procédé d’UGV". Nantes, 2012. http://www.theses.fr/2012NANT2109.
Texto completoMachining monitoring is essential to secure the process and optimise quality and productivity of the production. Most of monitoring solutions are designed only to detect problems. They do not allow describing or diagnosing harmful phenomena. The goal of the thesis is to answer this industrial issue by proposing an advanced monitoring solution, which can learn from process faults in order to improve the process. First monitoring of HSM spindles bearing is studied. Their low and very random service life is the main cause of spindles failures. A preliminary analysis of their behaviour during machining is realised in order to create appropriate spindle monitoring protocol. An end-of-life criterion is also designed. The whole allow to describe the state of spindle bearings and to maintain them. Secondly the causes of bearing damages are investigated. An innovative monitoring system is created, which realises a continuous acquisition of machining data. It is set up on several industrial machining centres working in industry. A method is created in order to identify critical machining operations. This method is applied in association to spindle state criteria to the monitored spindles. Thanks to it, all causes of bearing damages are found. Finally, our new approach of machining monitoring is generalised with the SMMS concept (Smart Machining Method and System). It is based on the acquisition of machining data and it operates using the Data Mining process. It is set up for different issues: a tool breakage anticipation criterion and a quality defect criterion are created. A machining data analysis method is also developed in order to help the continuous improvement of the machining process
Gimbert, Florent. "Mécanique de la banquise Arctique et des matériaux granulaires : deux milieux, deux approches". Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00846380.
Texto completoDansereau, Véronique. "Un modèle Maxwell-élasto-fragile pour la déformation et dérive de la banquise". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAU003/document.
Texto completoIn recent years, analyses of available ice buoy and satellite data have revealed the strong heterogeneity and intermittency of the deformation of sea ice and have demonstrated that the viscous-plastic rheology widely used in current climate models and operational modelling platforms does not simulate adequately the drift, deformation and mechanical stresses within the ice pack.A new alternative rheological framework named ''Maxwell-Elasto-Brittle” (Maxwell-EB) is therefore developed in the view of reproducing more accurately the drift and deformation of the ice cover in continuum sea ice models at regional to global scales. The model builds on an elasto-brittle framework used for ice and rocks. A viscous-like relaxation term is added to a linear-elastic constitutive relationship together with an effective viscosity that evolves with the local level of damage of the material, like its elastic modulus. This framework allows for part of the internal stress to dissipate in large, permanent deformations along the faults/leads once the material is highly damaged while retaining the memory of small, elastic deformations over undamaged areas. A healing mechanism is also introduced, counterbalancing the effects of damaging over large time scales.The numerical scheme for the Maxwell-EB model is based on finite elements and variational methods. The equations of motion are cast in the Eulerian frame and discontinuous Galerkin methods are implemented to handle advective processes.Idealized simulations without advection are first presented. These demonstrate that the Maxwell-EB rheological framework reproduces the main characteristics of sea ice mechanics and deformation : the strain localization, the anisotropy and intermittency of deformation and the associated scaling laws. The successful representation of these properties translates into very large gradients within all simulated fields. Idealized numerical experiments are conducted to evaluate the amount of numerical diffusion associated with the advection of these extreme gradients in the model and investigate other limitations of the numerical scheme. First large-deformation simulations are carried in the context of a Couette flow experiment, which allow a comparison with the result of a similar laboratory experiment performed on fresh-water ice. The model reproduces part of the mechanical behaviour observed in the laboratory. Comparison of the numerical and experimental results allow identifying some numerical and physical limitations of the model in the context of large-deformation and laboratory-scale simulations. Finally, the Maxwell-EB framework is implemented in the context of modelling the drift and deformation of sea ice on geophysical scales. Idealized simulations of the flow of sea ice through a narrow channel are presented. The model simulates the propagation of damage along arch-like features and successfully reproduces the formation of stable ice bridges
Haddouche, Kamel. "Apports d'automatique avancée dans la conduite d'un usinage". Bordeaux 1, 1995. http://www.theses.fr/1995BOR10545.
Texto completoTerrer, Elodie. "Microscopie avancée et diagnostic de la lésion carieuse". Thesis, Montpellier, 2016. http://www.theses.fr/2016MONT2201.
Texto completoMultiphoton microscopy and nonlinear spectroscopy is used to investigate caries process in dentin. Though a major calcified tissue of the teeth, the organic dentin phase comprises type I collagen fibers. Caries drive both dentin demineralization and collagen denaturation. Multiphoton microscopy is a powerful imaging technique because the biological materials are transparent to infrared frequencies and can be excited to penetration depths inaccessible to one photon confocal microscopy. The laser excitation greatly reduces photodamage to the sole focal region, and the signal to noise ratio is improved significantly. The method has been used to follow pathological processes involving collagen fibrosis or collagen destruction based on their 2-photon excited fluorescence (2PEF) emission and second harmonic generation (SHG). Combining multiphoton imaging with nonlinear spectroscopy we demonstrate that both 2PEF and SHG intensity of human dentin are strongly modified during tooth caries process and we discover that the ratio between SHG and 2PEF signals is a reliable parameter to follow dental caries. The ratio of the SHG/2PEF signals measured by nonlinear optical spectroscopy provides valuable information on caries process, specifically on the degradation of the organic matrix of dentin. The goal would be to bring these nonlinear optical signals to clinical application for caries diagnosis
Rabréau, Clément. "Modélisation avancée des performances dynamiques des broches UGV". Thesis, Nantes, 2018. http://www.theses.fr/2018NANT4082.
Texto completoHigh Speed Machining spindles are very efficient systems with a complex and sensitive dynamic behavior. Stability issues during machining can lead to bad quality of machined parts and also can reduce spindle lifetime. During this thesis, a numerical model has been developed to predict such instabilities. It also aims to improve the understanding of the spindle behavior and its variations with operating conditions (spindle speed, temperature, wear …). A phenomenological approach has been chosen for the model. At first, the axial behavior of the preloaded bearing system is considered. The axial equilibrium is resolved iteratively. The bearing stiffness are obtained from an analytical model that considers dynamic effects on bearing balls. The model updating performed on this axial model with a specific experiment lead to the complete bearing stiffness matrices and to preload parameters values. A radial model of the dynamic behavior of the spindle is then developed. An electromagnetic excitation device is used to measure the dynamic behavior of the spindle while rotating. The model parameters are identified from this experiment and some enrichment are proposed to improve the simulations results. Simulations are finally performed to study the influence of the operating conditions on the dynamic behavior of the spindle and also on its stability
Rocher, Laurence. "Imagerie Avancée du testicule : Echographie et IRM multiparamétriques". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS458.
Texto completoThe testicular imaging we developped in our department focused on two main subjects: infertility and tumoral characterization. It is based on multiparametric ultrasound and MRI. We defined diagnostic criteria of several pathologies, which may change the patient’s management, and we evaluated new modalities.We characterized Klinefelter patient’s testis.We determined the Color-Doppler features of Leydig cell tumors which are currently incidentally discovered and can benefit from monitoring or tumorectomy.We defined multiparametric US and MRI diagnostic’s criteria of burned out tumors in patients referred for US infertility screening.We demonstrated the ability of multiparametric MRI to improve the tumoral characterization using qualitative and quantitative enhancement parameters and apparent diffusion coefficient values.CEUS showed significant differences between the burned out tumors and other lesions.. Shear Wave Elastography (SWE) showed significant differences in testicular stiffness between normal, obstructive azoospermia on one side and non-obstructive azoospermic patients, but overlapped values seemed to minimize the potential clinical impact. Benign Leydig cell were softer compared to malignant tumors and burned out tumors. Association of B mode, color Doppler, and elastography allowed an optimal characterization.Ultrasensitive Doppler allowed a qualitative evaluation of the tumoral vascular architecture, a testicular vascularization assessment in case of acute scrotum, and a testicular perfusion quantification. We demonstrated a decreased testicular vascularization during the Valsalva maneuver confirming the hypoxic physiopathological explanation of the infertility process
Bais, Pierre. "Investigation cristallochimique avancée des composés photovoltaïques dérivés de Cu2ZnSnS4". Thesis, Nantes, 2017. http://www.theses.fr/2017NANT4046/document.
Texto completoCu2ZnSnS4-derived compounds (CZTS) show an increasing interest in the field of low-cost thin film solar cells. The best solar energy conversion efficiencies of CZTS-based devices, up to 12.6%, are obtained for both copper-poor and mixed S/Se compounds. Several studies suggest that Cu/Zn antisite defects can occur, leading to the modification of the kësterite structure (space group I4) to the so-called disordered kesterite which is of higher symmetry (space group I42m). In the mixed S/Se compounds, the question of the cationic and anionic disorder is of high importance for solar cells efficiency and as not been already addressed through a crystal structure point of view. This study is dealing with a thorough chemical crystallographic investigation of Cu2ZnSn(S,Se)4 compounds. The studied compounds have been synthesized via a ceramic route and have been characterized by the use of different techniques available in the laboratory and also with the use of the high resolution powder diffraction as well as the anomalous single crystal diffraction at the Synchrotron SOLEIL. Thanks to the combination of X-ray diffraction, energy dispersive X-ray spectroscopy and NMR spectroscopy, transmission electronic microscopy, precise information about the structure and the microstructure as a function of S/(S+Se) ratio or the actual deviation from the 2:1:1:4 stoichiometry is provided. The existence of a full solid solution between CZTSe and CZTS with the full disordered kesterite structure is definitely demonstrated. However, at the local scale, there is a difference of order between compounds according to the cooling or to the stoichiometric deviation
Giraud, Loïc. "Modélisation dynamique et gestion avancée de réseaux de chaleur". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT111.
Texto completoDistrict Heating (DH) are currently fast-growing in France. This situation is explained by their ability to exploit and disseminate massively, at a reasonable price, energy sources with low CO2 contents in the sectors of space heating and domestic hot water production, nowadays strongly emitters of greenhouse gases. Improving the control of these complex energy systems is a key issue for increasing their competitiveness and promote their development.This thesis focuses on the optimal control of DH systems. For this application, we have developed and tested an algorithm that optimizes, given a load prediction, the use of the production means, the supply temperature and the differential pressure. Compared to existing methods, the original features of the developed solution are to fully exploit the thermal storage capacity of the network and to determine the best compromise between costs for pumping and heat losses.This thesis begins with a work on dynamic modeling carried out at the component scale. Based on an experimental validation approach, we systematically sought the best compromise between accuracy and computational efficiency (Chapter 1). The case study, described in Chapter 2, is a virtual DH at the district scale, representing the Grenoble case. For the development of the advanced control system, we then present a linearized version of the distribution network model that we integrate into an optimizer relying on Mixed Linear Programming. The proposed control algorithm is described in Chapter 3. It combines a nonlinear dynamic model and the aforementioned optimizer. The topic of the fourth chapter is the evaluation of the performance of our algorithm by simulation and comparison with existing methods of control. A final chapter examines the robustness of the algorithm in real control conditions considering various sources of uncertainty
Xing, Dongmei. "Génération de trajectoires avec évitement d'obstacles en robotique avancée". Paris 11, 1987. http://www.theses.fr/1987PA112193.
Texto completoGross motions programming is an obligatory step for task planning in Robotics. This thesis comprises the conception and the implementation of a path planning module with obstacle avoidance, applicable to an assembly robot of an open mechanical chain, susceptible to be integrated in a robot programming language. The obstacles present in the work space of the robot are transformed into prohibited volumes in the N-dimensional joint space where the configuration of the robot is represented by a point. A recursive algorithm performing this transformation is presented. According to the number of the robot joints and to the state of encumbrance of the robot's environment, the choice between the simplified solution and the general solution is proposed, the simplified one allowing reduction of the computational burden for path planning. In case of a six-jointed robot working in a relatively clear environment, the simplified solution which approximates the last three joints of the robot by a sphere is analysed. The path generated for the simplified robot is collision-free for the whole six-joint robot. When the robot works in a cumbersome environment where it is impossible to find a collision-free path for the simplified robot or in the case of a redundant robot, the general solution which decomposes the joint space in a set of three-dimensional sub-spaces is analysed. One obtains thus, in a systematic manner, a collision-free path for the whole robot
Rademaker, Guido. "Métrologie avancée pour la lithographie par multi-faisceaux d’électrons". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT122.
Texto completoTo overcome throughput limitations of electron beam lithography, Mapper Lithography designed a machine that can expose with up to 649,740 parallel Gaussian electron beams. In the exposure process, the substrate is divided into 2.2-µm-narrow stripes with a 200 nm overlap. Several parameters need to be controlled: the critical dimensions of the features in the individual stripes; the stitching between the stripes; and the overlay with respect to a previous layer. In this thesis, different optical metrology techniques are explored. Six novel targets for an image based overlay have been developed to measure in-stripe overlay and stripe-to-stripe stitching and are evaluated by total measurement uncertainty (TMU) and measurement time. Scatterometry by spectroscopic reflectometry allows for measurement of non-uniform gratings using an effective critical dimension concept, resulting in a total measurement uncertainty metric down to 0.41 nm (3σ). Stitching can be measured by cross-resonant bow-tie antennae, consisting of four triangles straddling the stitching boundary. Simulations for three different stacks show that the DX and DY stitching errors can be reconstructed independently
Zghondi, Jad. "Modélisation avancée des excavations multi-supportées en site urbain". Lyon, INSA, 2010. http://theses.insa-lyon.fr/publication/2010ISAL0092/these.pdf.
Texto completoThe increasing complexity of deep excavation projects in urban areas and the limitation of the impact of these works on surrounding structures require the assessment of the behavior of these structures. This assessment should consider the calculation methods taking into account a limited knowledge (especially in pre-project phase) of the various parameters of the problem, especially the mechanical parameters of soils mobilized by the excavation process. The objective of this thesis is to assess the appropriateness of different approaches for the calculation of the multi-supported flexible retaining structures. It is based on the comparison of calculation results with those of a series of tests on small scale model and of several instrumented excavations representing a wide range of soil types, number and arrangement of supports and prestressing. The evaluation of the adequacy of computational approaches has necessitated the development of an accurate and thorough method of back analysis based on a number of indicators of errors (relative to the deformation of the wall, efforts in the supports and on the observed ground surface movements). The main objective of this method of back analysis is to determine, for each design approach, the most representative values of soil parameters that can best explain the behavior of the structure. The results show that the constitutive law used in numerical model of the excavation should present at least the level of complexity of the Hardening Soil Model (implemented in the FEM software Plaxis) in order to properly simulate the behavior of the excavation and that the process of back analysis is not relevant if one only considers only the deformation of the wall, but requires information on the loads in the supports
Faure, Adrien. "Simulation avancée pour la gestion de ressources des superordinateurs". Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALM056.
Texto completoHigh-Performance Computing (HPC) provides the computational power dedicated to solving complex problems of our society.HPC computers are large scale and distributed infrastructures composed of several thousands of computing cores.The management of theses systems is left to unique software: the Resources and Jobs Management System (RJMS).The objective of the RJMS is multiple: Managing the physical infrastructure, and handling the user requests to access to the computing power.The scheduling algorithm is the cornerstone of the RJMS, it decides where and when the user's jobs will be executed.Scheduling is a difficult problem; to manage large scale platforms RJMS needs to dispose of efficient yet scalable scheduling heuristicsEvaluating and testing new scheduling algorithms is crucial before releasing it in production.Any failure can have a dramatic impact on the HPC platform leading to wasted time, energy, and resources.The lack of a platform dedicated experiments and tests compels RJMS designers and HPC center's administrators to use different tools and methodologies to evaluate new algorithms.In the first part of this dissertation, we present and evaluate a new scheduling heuristics with job redirection.The evaluation is done using a large simulation campaign, it results that by redirecting jobs can improve the efficiency of the scheduling.In the second part, we focus on and extend the tools and methodologies available to experiment with RJMS.This part is twofold: Firstly, we propose to extend scheduling simulations with job models to simulate network contention between jobs.Secondly, we propose new tools that enable experiment with production RJMS without the need for an HPC platform.This dissertation aims to broaden the experimental landscape of tools and methodologies to experiment with RJMS and therefore help the release in the production of new scheduling algorithms
Chaves, Frota Joao Miguel. "Prévision du bruit d'une hélice avancée subsonique en incidence". Ecully, Ecole centrale de Lyon, 1998. http://www.theses.fr/1998ECDL0031.
Texto completoLegault, Mélissa y Mélissa Legault. "Effet des produits de glycation avancée sur la fonction endothéliale". Master's thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/25298.
Texto completoDes études récentes ont montré que les produits de glycation avancée (AGE) pouvaient jouer un rôle dans la pathogénèse des troubles vasculaires en insuffisance rénale. Nous avons alors émis l’hypothèse que l’augmentation de la concentration des AGE observé dans le cas d’insuffisance rénale joue un rôle important dans la pathogenèse de l’hypertension artérielle, entre autres, en aggravant la dysfonction endothéliale et les dommages vasculaires. De plus, nous croyions que les effets des AGE sur la dysfonction endothéliale sont causés par l’activation des récepteurs RAGE sur les cellules vasculaires. Pour vérifier ces hypothèses nous avons étudié dans un premier temps l’effet du S100b, un agoniste des récepteurs des AGE (RAGE), sur la réponse vasodilatatrice dépendante de l’endothélium au carbachol et la réponse vasoconstrictrice à la phényléphrine et l’ET-1 sur des segments d’aorte de rats in vitro montés dans des bains à organe, et, dans un deuxième temps, l’effet du S100b sur la fonction endothéliale, notamment l’expression de la NO synthase endothéliale (eNOS) et la production des radicaux libres de l’oxygène (ROS). Les résultats obtenus indiquent que le S100b induit une diminution de la réponse vasorelaxante dépendante du NO au carbachol. Par contre, le S100b entraine une augmentation de la réponse vasoconstrictrice à la phényléphrine. Ce dernier effet n’est pas modifié dans les vaisseaux dénudés de l’endothélium, ni l’inhibition de la production de NO dans les vaisseaux intacts. L’effet du S100b est néanmoins atténué en présence d’indométacine, un inhibiteur de la cyclo-oxygénase, suggérant que l’activation des RAGE module la production de certaines eicosanoides. Enfin, le S100b induit une diminution de la réponse vasoconstrictrice à l’ET-1 qui est bloquée en présence de L-NAME, un inhibiteur de la production de NO. Ces derniers résultats indiquent que l’effet du S100b sur la réponse vasoconstrictrice à l’ET-1 dépend de la relâche de NO. Par ailleurs les résultats obtenus sur des segments d’aorte de rats et des cellules endothéliales en culture indiquent que le S100b n’affecte pas la production de ROS dans les segments d’aorte, bien qu’il stimule leur production dans les cellules endothéliales isolées. Par contre, le S100b tend à augmenter l’expression de la eNOS dans l’endothélium des vaisseaux en culture. En conclusion, la stimulation des RAGE avec le S100b affecte la réponse aux agents vasoconstricteurs et vasodilatateurs sur des segments d’aorte de rats normaux de façon dépendante et, possiblement, indépendante de l’endothélium. Ces effets seraient causés, en partie, par la modulation de la relâche de NO et de l’expression de la eNOS, ainsi que par la production d’eicosanoides et de ROS et, possiblement, l’activation du système endothélinergique. Ainsi, les AGE peuvent affecter le tonus vasculaire en modifiant la fonction endothéliale.
Recent studies suggest that advanced glycation end products (AGEs) could play an important role in vascular pathogenesis in kidney disease. We hypothesized that increased AGEs concentrations in kidney disease play an important role in the pathogenesis of arterial hypertension, by increasing endothelial dysfunction and vascular damages. Furthermore, we believe that the effects of AGEs on endothelial dysfunction are caused by the activation of AGEs receptors (RAGE) on vascular cells. To test this hypothesis, we studied first the effect of S100b, an AGEs receptor agonist, on the endothelium dependent vasodilatation response to carbachol and the vasoconstriction response to phenylephrine and ET-1 on rats thoracic aorta segments in vitro placed in organ bath, and, secondly, the effect of S100b on the endothelial function, especially the expression of endothelial NO synthase (eNOS) and the production of reactive oxygen species (ROS). Our results indicate that S100b induces a decrease in the NO dependent vasodilatation response to carbachol, but an increase in the vasoconstriction response to phenylephrine. This effect of S100b on phenylephrine response is not modified in vessels without endothelium, nor following the inhibition of the NO production in intact vessels. The effect of S100b is however decreased with indometacine, a cyclooxygenase inhibitor, suggesting that RAGE activation modulates the production of eicosanoids. Finally, S100b induces a decrease in the vasoconstriction response to ET-1 that is blocked in presence of L-NAME, a NO production inhibitor. These results indicate that the effect of S100b on the vasoconstriction response to ET-1 is dependent on NO release. In addition, results obtained on cultured rat aorta segments and endothelial cells indicate that S100b does not affect the production of ROS althouch it stimulates their production in isolated endothelial cells. Otherwise, S100b tend to increase the expression of eNOS in the endothelium of cultured vessels. In conclusion, the stimulation of RAGE by S100b affects the response to vasoconstrictors and vasodilators agents on intact rat thoracic aorta segments in an endothelium dependant and, possibly, independent manner. These effects may be related, in part, to the modulation of NO release and eNOS expression, the production of eicosanoids and ROS, and, possibly, the activation of the endothelinergic system. Thus, AGEs could affect vascular tone through the modulation of the endothelial function.
Recent studies suggest that advanced glycation end products (AGEs) could play an important role in vascular pathogenesis in kidney disease. We hypothesized that increased AGEs concentrations in kidney disease play an important role in the pathogenesis of arterial hypertension, by increasing endothelial dysfunction and vascular damages. Furthermore, we believe that the effects of AGEs on endothelial dysfunction are caused by the activation of AGEs receptors (RAGE) on vascular cells. To test this hypothesis, we studied first the effect of S100b, an AGEs receptor agonist, on the endothelium dependent vasodilatation response to carbachol and the vasoconstriction response to phenylephrine and ET-1 on rats thoracic aorta segments in vitro placed in organ bath, and, secondly, the effect of S100b on the endothelial function, especially the expression of endothelial NO synthase (eNOS) and the production of reactive oxygen species (ROS). Our results indicate that S100b induces a decrease in the NO dependent vasodilatation response to carbachol, but an increase in the vasoconstriction response to phenylephrine. This effect of S100b on phenylephrine response is not modified in vessels without endothelium, nor following the inhibition of the NO production in intact vessels. The effect of S100b is however decreased with indometacine, a cyclooxygenase inhibitor, suggesting that RAGE activation modulates the production of eicosanoids. Finally, S100b induces a decrease in the vasoconstriction response to ET-1 that is blocked in presence of L-NAME, a NO production inhibitor. These results indicate that the effect of S100b on the vasoconstriction response to ET-1 is dependent on NO release. In addition, results obtained on cultured rat aorta segments and endothelial cells indicate that S100b does not affect the production of ROS althouch it stimulates their production in isolated endothelial cells. Otherwise, S100b tend to increase the expression of eNOS in the endothelium of cultured vessels. In conclusion, the stimulation of RAGE by S100b affects the response to vasoconstrictors and vasodilators agents on intact rat thoracic aorta segments in an endothelium dependant and, possibly, independent manner. These effects may be related, in part, to the modulation of NO release and eNOS expression, the production of eicosanoids and ROS, and, possibly, the activation of the endothelinergic system. Thus, AGEs could affect vascular tone through the modulation of the endothelial function.
Galindo, Catherine. "Dégradation de colorants par la méthode d'oxydation avancée UV / H2O2". Mulhouse, 1998. http://www.theses.fr/1998MULH0520.
Texto completoTourre-Malen, Catherine. "La féminisation des sports et des loisirs équestres : une avancée ?" Aix-Marseille 1, 2004. http://www.theses.fr/2004AIX10061.
Texto completoAbi-Farraj, Firas. "Contributions aux architectures de contrôle partagé pour la télémanipulation avancée". Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S120/document.
Texto completoWhile full autonomy in unknown environments is still in far reach, shared-control architectures where the human and an autonomous controller work together to achieve a common objective may be a pragmatic "middle-ground". In this thesis, we have tackled the different issues of shared-control architectures for grasping and sorting applications. In particular, the work is framed in the H2020 RoMaNS project whose goal is to automatize the sort and segregation of nuclear waste by developing shared control architectures allowing a human operator to easily manipulate the objects of interest. The thesis proposes several shared-control architectures for dual-arm manipulation with different operator/autonomy balance depending on the task at hand. While most of the approaches provide an instantaneous interface, we also propose architectures which automatically account for the pre-grasp and post-grasp trajectories allowing the operator to focus only on the task at hand (ex., grasping). The thesis also proposes a shared control architecture for controlling a force-controlled humanoid robot in which the user is informed about the stability of the humanoid through haptic feedback. A new balancing algorithm allowing for the optimal control of the humanoid under high interaction forces is also proposed
Rampal, Pierre. "Etude de la dérive et de la déformation de la banquise Arctique par l'analyse de trajectoires Lagrangiennes". Phd thesis, Université Joseph Fourier (Grenoble), 2008. http://tel.archives-ouvertes.fr/tel-00352799.
Texto completoOn observe une disparition significative et progressive de la banquise depuis environ un demi siècle, disparition qui s'est accélérée au cours des dernières années, a tel point qu'elle dépasse les prévisions les plus alarmistes des modèles les plus sophistiqués.
Nous montrons dans cette thèse que cette sous-estimation pourrait être le résultat de l'utilisation d'un cadre de modélisation inadéquat : en considérant la banquise comme un milieu continu fluide, les modèles actuels ne parviennent pas a reproduire, entre autres, les propriétés d'intermittence et d'hétérogénéité de son champs de déformation que nous mettons en évidence. De ce fait, la fracturation de la banquise, bien que largement observable sur le terrain et/ou par satellite, n'est pas correctement reproduite. Or, elle apparait comme essentielle au regard de son contrôle sur le caractère isolant décrit plus haut.
Dans ce travail, nous suggérons également d'adopter un nouveau schéma de modélisation, considérant la banquise comme une plaque rigide ayant un comportement mécanique elasto-fragile.
Rampal, Pierre. "Étude de la dérive et de la déformation de la banquise Arctique par l'analyse de trajectoires Lagrangiennes". Grenoble 1, 2008. http://www.theses.fr/2008GRE10239.
Texto completoThe arctic sea ice is a solid plate that floats on the ocean over several millions of squared kilometers. Temporal and spatial variations of the sea ice thickness control the mechanical and thermal exchanges between the arctic atmosphere and the Arctic Ocean. This later plays a fundamental role on the thermohaline circulation, and consequently, on the earth climate. Thus, as it isolates the ocean from the atmosphere, the sea ice cover can be viewed as a key parameter of the global climate. Since approximately five decades, we can observe a significant sea ice shrinking, which accelerated during the last years. All the most sophisticated global climate models under-estimate this acceleration. In this work, we show that this under-estimation can be due to the modeling framework used in these models: indeed, the sea ice cover is modeled as a viscous plastic material and, as an example, do not exhibit some fundamental properties of its dynamics, i. E. The intermittency and the heterogeneity of its deformation field. Then, the induced fracturing of the sea ice cover is not reproduced, and its consequences in terms of energy exchanges between the atmosphere and the ocean are neglected. We suggest that the arctic sea ice has to be considered as a deforming solid plate, and modeled with an alesto-brittle rheology
Ponomareva, Svetlana. "Développement et caractérisation avancée de matériaux magnétiques durs de haute performance". Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY035/document.
Texto completoNowadays in medicine and biotechnology a wide range of applications involves magnetic micro/nano-object manipulation including remote control of magnetic beads, trapping of drug vectors, magnetic separation of labelled cells and so on. Handling and positioning magnetic particles and elements functionalized with these particles has greatly benefited from advances in microfabrication. Indeed reduction in size of the magnet while maintaining its field strength increases the field gradient. In this context, arrays made of permanent micromagnets are good candidates for magnetic handling devices. They are autonomous, suitable for integration into complex systems and their magnetic action is restricted to the region of interest.In this thesis we have elaborated an original approach based on AFM and MFM for quantitative study of the magnetic force and associated force gradients induced by TMP micromagnet array on an individual magnetic micro/nano-object. For this purpose, we have fabricated smart MFM probes where a single magnetic (sub)micronic sphere was fixed at the tip apex of a non-magnetic probe thanks to a dual beam FIB/SEM machine equipped with a micromanipulator.Scanning Force Microscopy conducted with such probes, the so-called Magnetic Particle Scanning Force Microscopy (MPSFM) was employed for 3D mapping of TMP micromagnets. This procedure involves two main aspects: (i) the quantification of magnetic interaction between micromagnet array and attached microsphere according to the distance between them and (ii) the complementary information about micromagnet array structure. The main advantage of MPSFM is the use of a probe with known magnetization and magnetic volume that in combination with modelling allows interpreting the results ably.We conducted MPSFM on TMP sample with two types of microparticle probes: with superparamagnetic and NdFeB microspheres. The measurements carried out with superparamagnetic microsphere probes reveal attractive forces (up to few tens of nN) while MFM maps obtained with NdFeB microsphere probes reveal attractive and repulsive forces (up to one hundred of nN) for which the nature of interaction is defined by superposition of microsphere and micromagnet array magnetizations. The derived force and its gradient from MFM measurements are in agreement with experiments on microparticle trapping confirming that the strongest magnetic interaction is observed above the TMP sample interfaces, between the areas with opposite magnetization. Thanks to 3D MFM maps, we demonstrated that intensity of magnetic signal decays fast with the distance and depends on micromagnet array and microsphere properties.Besides the magnetic interaction quantification, we obtained new information relevant to TMP sample structure: we observed and quantified the local magnetic roughness and associated fluctuations, in particular in zones of reversed magnetization. The variation of detected signal can reach the same order of magnitude as the signal above the micromagnet interfaces. These results complete the experiments on particle trapping explaining why magnetic microparticles are captured not only above the interfaces, but also inside the zones of reversed magnetization.Quantitative measurements of the force acting on a single (sub)microsphere associated to the modelling approach improve the understanding of processes involved in handling of magnetic objects in microfluidic devices. This could be employed to optimize the parameters of sorting devices and to define the quantity of magnetic nanoparticles required for labelling of biological cells according to their size. More generally these experimental and modelling approaches of magnetic interaction can meet a high interest in all sorts of applications where a well-known and controlled non-contact interaction is required at micro and nano-scale
Naaim, Alexandre. "Modélisation cinématique et dynamique avancée du membre supérieur pour l’analyse clinique". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1014/document.
Texto completoSoft Tissue Artefact (STA) is one of the most important limitations when measuring upper limb kinematics through marker-based motion capture techniques, especially for the scapula. Multi Body Optimisation (MBO) has already been proposed to correct STA when measuring lower limb kinematics and can be easily adapted for upper limb. For this purpose, the joint kinematic constraints should be as anatomical as possible. The aim of this thesis was thus to define and validate an anatomical upper limb kinematic model that could be used both to correct STA through the use of MBO and for future musculoskeletal models developments. For this purpose, a model integrating closed loop models of the forearm and of the scapula belt have been developed, including a new anatomical-based model of the scapulothoracic joint. This model constrained the scapula plane to be tangent to an ellipsoid modelling the thorax. All these models were confronted to typical models extracted from the literature through cadaveric and in vivo intracortical pins studies. All models generated similar error when evaluating their ability to mimic the bones kinematics and to correct STA. However, the new forearm and scapulothoracic models were more interesting when considering further musculoskeletal developments: The forearm model allows considering both the ulna and the radius and the scapulothoracic model better represents the constraint existing between the thorax and the scapula. This thesis allowed developing a complete anatomical upper limb kinematic chain. Although the STA correction obtained was not as good as expected, the use of this approach for a future musculoskeletal models has been validated
Zazou, Hicham. "Dégradation de pesticides dans l’eau par les procédés d’oxydation avancée (POA)". Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1071/document.
Texto completoThe intensive use of pesticides in agriculture generates, nowadays, an unprecedented contamination of surface water and groundwater. Conventional treatments applied to waste water containing organic pollutants are based on biological treatments méthods or physical mass transfer methods (decantation, filtration, adsorption of the pollutants on activated carbon), chemical oxidation with ozone, chlorine, etc. However, these methods remain ineffective for the treatment of water polluted by persistent organic pollutants (POPs). Advanced oxidation processes are implemented to degrade and mineralize these pollutants. This PhD thesis work aims to establish an experimental protocol to degrade and mineralize pesticides, chemicals widely used in agriculture in Morocco, such as monochlorobenzene, 1,2-dichlorobenzene, 2,4,5-trichlorophenoxy-acetic acid , and imazalil using the electro-Fenton and anodic oxidation processes with DD Pt or DSA anodes. Thus, the rate of mineralization was 92%, 95%, 92% and 97% for the monochloro-benzene, the 1,2-dichlorobenzene, the 2,4,5-trichlorophenoxyacetic acid , and the imazalil, respectively, after 4 h treatment by electro-Fenton process. These results confirm the effectiveness of electrochemical advanced oxidation processes for treating water polluted by pesticides
Martignac, Marion. "Dégradation de médicaments dans l’eau par un procédé d’oxydation avancée photochimique". Toulouse 3, 2013. http://www.theses.fr/2013TOU30321.
Texto completoSeveral pharmaceutical compounds have been found in surface waters (sea, rivers…), ground waters and drinking water at low concentrations (ng L-1). These compounds are from human and veterinary origin, as the consumption of the administrated drugs results in their excretion, into both urine and faeces, either unaltered as the parent compounds or as metabolites. Contamination may also originate from manufacturing wastes. The Sewage Treatment Plant (STP) is currently not designed for the removal of these compounds at trace level. Oxidation processes could be a solution for the degradation and removal of these pollutants. Advanced oxidation processes (AOPs) using catalytic and photochemical methods have led to an improvement in oxidative degradation procedures for organic compounds. AOPs comprise a range of strategies for water treatment to achieve complete mineralization of organic pollutants. Oxidation of organic pollutants by the combination of UV radiation and oxidants (ozone, H2O2…) implies in most cases generation of hydroxyl radicals. These radicals are one of the most reactive and non selective oxidizing species. Besides the generation of hydroxyl radicals, organic free radicals are produced and their trapping by molecular oxygen initiates the chain of oxidative degradation. We investigated the removal of different pharmaceuticals (paracetamol, carbamazepine, penicillin, bortezomib and 5-fluorouracil) by a photochemical advanced oxidation process. We used several analytic methods like liquid chromatography coupled with mass spectrometry in order to follow the kinetic and the mechanism of degradation. Experiments were performed in annular photochemical reactor lab version of a reactor at pilot scale Loïlyse®, the obtained results validated the application domain
Tona, Paolino. "Conception de systèmes de commande avancée par calculateur : méthodologie et applications". Grenoble INPG, 2000. http://www.theses.fr/2000INPG0018.
Texto completoTarabbia, Marc. "Caractérisation physico-chimique, simulation et modélisation d'une technologie analogique avancée BICMOS". Lyon, INSA, 1993. http://www.theses.fr/1993ISAL0003.
Texto completoThe goal of this study is to understand the physico-chemical phenomenon induced by the manufacturing of bipolar analogue integrated circuits. This study helps us to introduce new structures on the process flow. The electrical characteristics of new cells supply more freedom to designers and simplify the layout of circuits. The process modelization (SUPREM and SUPRA) and device simulation (SEDAN and PISCES) were done by improving default parameters and checking links between each of them. New steps introduce with in to process flow to make MOS structures were monitored by simulation. It checks the conservative basic bipolar cells performances. SIMS profiles and electrical measurements verify the simulation results. The feasibility of the integration of NMOS and PMOS on the bipolar process flow is done. We have introduce an isolated vertical PNP to simplify integrated circuit design and to get full complementary bipolar structures. Some process options remain to be defined
Oblin, Nicolas. "Réification du corps et du "connaître" dans la société industrielle avancée". Montpellier 3, 2004. http://www.theses.fr/2004MON30060.
Texto completoThe main subject of this thesis is based on the body's and the culture's reification. The concept, as the Hungarian philosopher György Lukács (1885-1971) defined it, means that anything, which is and occurs, is turned into the abstraction of value, which one is represented by goods. So, this work, in a multidisciplinary and multireferential way, focuses on the close links between the body and “the fact of knowing” when we look at the concrete totality in the course of the capitalism modernity. The development sets out to analyse with a critical eye the “exemplary cases”, these “analysers” that constitute the Nazi's Regime, the body's industrialization, the sport's body as well as the higher education in its contemporary link to knowledge
Trabelsi, Amine. "Contribution à l'analyse et à la commande avancée des systèmes multivariables". Toulon, 2006. http://www.theses.fr/2006TOUL0012.
Texto completoThis thesis treats the modeling and the adaptive optimal control of complex systems using the concepts of the fuzzy logic and the neural networks. The accent is put on the class of the dynamic, nonlinear, stochastic and multivariables systems. In this context, we proposed a modeling method of these systems based on the fuzzy clusterine technique. In fact, from an available data base of the system to study, a global fuzzy control model, formed by the weighted set of fuzzy local linear models of Takagi-Sugeno type, is established. The fuzzy model parameters are then adapted by the recursive (east squares algorithm with forgetting factor. The proposed control method is of optimal type by quadratic criteria. It Is based on a neuronal simulation model and a fuzzy Taftagi-Sugeno control moxtel. The resulting error between the outputs of these two models will serve to adapt the fuzzy model's parameters, and therefore the controller's parameters. This method has been applied with success for the control of the air temperature and the humidity inside of an agricultural greenhouse
Coque, Yves. "Proposition d'outils d'optimisation de procédé d'oxydation avancée (POA) par UV/H2O2". Pau, 2002. http://www.theses.fr/2002PAUU3012.
Texto completoSillet, Arnauld-Amaury. "Traitement de la DCO dure par photooxydation avancée, couplage UV/H2O2". Lyon, INSA, 2001. http://www.theses.fr/2001ISAL0087.
Texto completoThe purpose of this work was to study the application of UV /H20 2 Advanced Oxidation Process (AOP) to industrial wastewaters containing non-biodegradable organic matter. Advanced oxidation bas been applied prior to release of pretreated effluents into a municipal sewage system to treat toxic effluents and landfill leachates and as post-treatment before releasing into a natural ecosystem. It has also been used to remove residual color from previously bio-treated dyeing wastewater. Several key factors have been studied : pH, hydroxyl radical scavengers, initial hydrogen peroxide concentration, irradiation time, flow rate, UV irradiation source, quality of the protecting quartz and thickness of the irradiated layer. The advanced oxidation UV/HzOz process appears to be a promising technique. Furthermore, organic pollution is not transferred but instead oxidized to carbon dioxide