Dissertations / Theses on the topic 'Caractérisation de matériaux complexes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Caractérisation de matériaux complexes.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Bouzzit, Aziz. "Ellipsométrie acoustique pour le suivi et la caractérisation de matériaux complexes." Electronic Thesis or Diss., CY Cergy Paris Université, 2024. http://www.theses.fr/2024CYUN1304.
Full textComplex materials are at the heart of major societal challenges in most major fields such as energy, transport, environment, heritage conservation/restoration, health and safety. Because of the opportunities for innovation offered in terms of features, these materials are giving rise to new problems of multi-physical and multi-scale analysis and understanding. The same applies to the instrumentation needed to characterize them.Acoustic methods, which are widely used in the non-destructive characterization of complex media, make use of the propagation properties of mechanical waves in these materials, which can be heterogeneous and anisotropic.In a multi-scale approach, the advantage of ultrasonic methods is that they are particularly sensitive to mechanical properties such as elasticity, rigidity and viscosity. The heterogeneous and multiphase nature of a complex medium thus leads to the notion of a viscoelastic medium, characterized by generalized complex Lamé coefficients (��∗, ��∗) and their variation as a function of frequency.The objective of this thesis is to develop a method for characterizing these complex viscoelastic materials that simultaneously measures the variation of the two generalized complex Lamé coefficients (��∗, ��∗) versus the frequency. The proposed approach is to follow, in space and in time, the propagation of the Rayleigh wave and to extract its ellipsometric parameters (ellipticity χ and orientation θ) in addition to the propagation parameters (k' and k'') conventionally determined. Based on the wave detection by 3D laser vibrometry at the surface of the complex material, and by means of 2D Gabor analysis in Quaternion space, the estimation of propagation and ellipsometric parameters gives access to the complete characterization of the complex material only by studying the interaction of a Rayleigh wave with the medium.The theoretical developments proposed in this work, together with experimental and simulation results, confirm the value of acoustic ellipsometry for characterizing these complex materials
Walti, Olivier. "Contribution à la caractérisation des matériaux magnétiques soumis à des ondes complexes." Lille 1, 1995. http://www.theses.fr/1995LIL10078.
Full textDelaunay, Wylliam. "Synthèse et caractérisation de nouveaux matériaux organophosphorés pour des applications en optoélectronique." Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00942602.
Full textWang, Yu. "Développement d'un capteur magnéto acoustique on-chip pour la caractérisation des matériaux complexes." Thesis, Cergy-Pontoise, 2014. http://www.theses.fr/2014CERG0717/document.
Full textAcoustic and electromagnetic waves are key probing candidates for characterizing their propagation media with minimum perturbation. Often used with independent sensors based on specialized transducing materials, the approach developed here provides an on-ship multimodal sensor using the same sensing material for probing the acoustic and electromagnetic properties of the material. To meet a wide range of applications, the choice of the active piezoelectric element is carried out on an AT cut quartz. The study focuses on the steps leading in fine to an on-chip magneto-acoustic sensor with a contactless excitation.The theoretical study of a magneto-acoustic sensor inductively excited and loaded by a viscous fluid is first carried out. This sensor consists of three elements: a radio frequency (RF) sensor, a high quality factor RF resonator and a quartz on which two ring electrodes have been deposited. The complex viscosity of the studied material is derived from the electrical impedance of the complete system. The measurements carried on etalon viscoelastic materials show a good agreement with the theoretical results.The integration of the RF resonator on the piezoelectric element being via circular electrodes, a preliminary study is performed for determining the acoustic waves that can be generated in the quartz and their interaction with the electrodes. The laser vibrometry measurements indicate that Lamb waves are generated in a wide frequency range, from 100 kHz to 20 MHz. The analysis of the spatial pulse response of the sensor surface by 3D Gabor transform locates the source of these waves on the edge of the electrodes. Furthermore, the study of the disk at it fundamental frequency points out the high nonlinear mechanical behavior of the quartz.The plane RF multi-turn resonator and its integration on the quartz disk of the magneto-acoustic on-chip sensor are then studied. The experimental results of impedance and laser vibrometry measurements validate the proposed theoretical model. The selected frequency range (between 5 and 20 MHz) allows one to consider micro rheological measurements
Bottois, Paul. "Caractérisation de matériaux composites sur structures à géométries complexes par problème inverse vibratoire local." Thesis, Le Mans, 2019. http://www.theses.fr/2019LEMA1026/document.
Full textComposite materials have high stiffness for a low mass. Common methods to represent the vibratory behavior of these materials are often not appropriate, as they do not characterize the material being shaped. However, the dynamic properties of the material can vary during its manufacture and can be dependent on space. New approaches are therefore needed to better understand these phenomena.The approach proposed in this thesis uses a local inverse method, strongly inspired by the FAT (Force Analysis Technique) for the identification of material properties. This work proposes to extend the scope of this method to composite structures with complex geometry, replacing the analytical operator with a Finite Element operator. Composite materials are then considered homogeneous and their properties are sought. In the case of a complex geometry two pairs of parameters are identified, the homogenized Young's modulus of complex traction and the homogenized Young's modulus of complex bending, resulting from the coupling between the longitudinal and transverse movements. As inverse methods are known to be sensitive to measurement uncertainties, a probabilistic approach is presented to regularize measurement noise. The regularization is then automatic and does not require any parameters to be adjusted.The identification of structural parameters, which can be global or local, is presented on straight beams, curved beams, plates and shells
Ndiaye, Mame Cheikh Anta. "Caractérisation en solution et étude théorique d’un polyoxomolybdate géant à base de 132 atomes de molybdène." Strasbourg, 2010. http://www.theses.fr/2010STRA6093.
Full textUnderstanding the structures formed by water molecules at the nanoscale is a major scientific challenge requiring close cooperation between physicists, chemists and biologists. This work focuses an the chemistry of aqueous polyoxomolybdates to develop negatively charged porous inorganic nanocapsules displaying varied polyhedral shapes. The supramolecular organization of water mole cules confined to the nanometer scale was studied in the solid state using single crystal X-ray diffraction and the PACHA algorithm. In this work we have synthesized and characterized a nanoscale object in solution, the polyoxometalate (POM) Mol32-ACET. By tH NMR and BC spectroscopy, small angles neutron scattering and quasi-elastic neutron scattering (spin echo) to access to the dynamics of the water encapsulated as a nanodroplet of 1 nm radius. Another part of this work was to understand the mechanism of self-assembly of these objects using theoretical tools derived from the theory of density functional theory (DFT) or using the PACHA (Partial Charges Analysis) software developed in the laboratory
Rousseau, Theodulf. "Elaboration et caractérisation de cellules solaires organiques à base de nouvelles classes de matériaux actifs." Angers, 2011. http://tel.archives-ouvertes.fr/tel-00984367.
Full textThis work deals with the preparation and characterization of organic solar cells based on novel classes of soluble molecular donors. The first chapter is devoted to the study of bulk heterojunction organic solar cells based on poly(3-hexylthiophene) and a soluble derivative of fullerene C60. This type of device is used as a model system to analyze the various experimental parameters involved in the fabrication and optimization of organic solar cells. The experimental procedures defined on the basis of these studies have been subsequently applied to the evaluation of two classes of molecular donors namely diketopyrrolopyrrole (DPP) and boron dipyrromethene (BODIPY). The work on DPP-based donors involved the fabrication of various series of bilayer and bulk heterojunction solar cells. The results of these investigations have led to interesting performances and to a better understanding of structure-properties relationships in this family of molecular donors. The last part of this work concerned the study and realization of solar cells based on an original class of molecular donors derived from BODIPY. The characterization of the electronic properties of different families of BODIPYs as well as the preparation and study of several series of solar cells have led to important progress, and power conversion efficiencies among the highest reported so far for molecular BHJ solar cells based on soluble C60 derivative have been obtained. Furthermore, first evidences of cooperative effects in molecular BHJ using multiple donors have also been presented
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.
Full textThis 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
Molina, Émilie. "Matériaux hybrides mésoporeux fonctionnalisés par des polymères : élaboration, caractérisation physico-chimique et applications biomédicales." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2015. http://www.theses.fr/2015ENCM0024.
Full textMesostructured hybrid materials were prepared by using original silica-structuring agents, which are polyion complex (PIC) micelles. A great advantage of PIC micelles is that they can be reversibly assembled in aqueous solution by varying physico-chemical parameters. PIC micelles are formed by electrostatic complexation between a neutral-anionic double-hydrophilic block copolymer (DHBC) and an oppositely charged agent of micellization; here a poly(ethylene oxide)-b-poly(acrylic acid) PEO-b-PAA (synthesized by controlled radical polymerization by atom transfer ATRP) and commercial polyamines (oligochitosan OC or aminoglycoside antibiotics) were respectively used. First, the influence of various parameters (pH, temperature, concentration) on PIC micelle association properties was investigated in aqueous solution. Then, the effect of these parameters on the silica mesostructuring process was studied, it provides a better understanding of the formation mechanisms. It was shown that varying interactions between constituents allows to control the mesostructure (hexagonal, lamellar, wormlike) and the material morphology (nanoparticle, microparticle). Finally, the versatility of the approach has been demonstrated with PEO-b-PAA/aminoglycoside systems. Drug-loaded ordered mesostructured materials were prepared following a one-pot route. Moreover, taking advantage of the high degree of functionality of DHBC polymers and of the reversibility of the micellization, polyacid-functionalized mesoporous materials were directly prepared by selectively extracting the micellization agent. PAA-functionalized silica materials were then used to complex diverse active entities such as drugs, whose delivery could be pH-controlled
Nurit, Marvin. "numérisation et caractérisation de la réflectancelocale des surfaces complexes pour l'inspection visuelle." Electronic Thesis or Diss., Bourgogne Franche-Comté, 2022. http://www.theses.fr/2022UBFCK112.
Full textMastering the visual perception of the surfaces of manufactured products is a central issue for industry. However, in industry, the quality of surfaces is often assessed by human inspectors. Only a few specific cases use an instrumental or photometric approach. Among the photometric approaches, one of them is experiencing significant growth: Reflectance Transformation Imaging (RTI). The RTI makes it possible to obtain a reduced and simplified estimate of the Bidirectional Reflectance Distribution Function (BRDF) and an estimate of the geometry of the surface. However, this technique has limitations in terms of data acquisition and processing. The objective is therefore to correct some of these limits in order to improve the RTI and, consequently, the visual quality control of surface conditions in industry.One of these limitations is the large amount of data, complex to analyze, obtained with an RTI acquisition. We propose a methodology to characterize the appearance of surfaces from RTI measurements. The characterization of surface states is based on the use of appearance, statistical and geometric descriptors. From the descriptors extracted from the RTI acquisitions, we propose a method to estimate the multi-scale and multi-level visual salience in each pixel and thus make it possible to discriminate surface anomalies. A methodology, to segment RTI data using salience, is then applied to an application case. The method makes it possible to determine the most relevant descriptors for segmentation. Distance calculation is extended to RTI acquisitions in order to compare surface states. These methods are based on the Mahalanobis distance using the descriptors.Another limitation of RTI is measurement bias. Some descriptors are invariant to these measurement biases except that of the exposure time for which no descriptor is insensitive. We then propose to use High Dynamic Range (HDR) coupled with RTI (HD-RTI). The coupling is done in such a way as to take into account the specificities of each of the techniques in order to optimize the RTI acquisition time while allowing the full measurement of the Dynamics of the scene in each angular position of the light source. With HD-RTI stereo-photometric data, we can virtually reconstruct the scene by simulating an arbitrary exposure time, but also better characterize and therefore discriminate surface anomalies
Brotons, Valérie. "Elaboration et caractérisation de nouveaux matériaux carbonés : c60 et nanotubes de carbone. Potentiel d'application à la catalyse hétérogène." Montpellier 2, 1997. http://www.theses.fr/1997MON20045.
Full textToumi, Souad. "Caractérisation des matériaux complexes et de leurs endommagements par la technique de la coda ultrasonore alliée à l'acoustique non linéaire." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1024/document.
Full textNonlinear Resonance (NR) and Coda Wave Interferometry (CWI) have proved to be efficient to detect and follow the evolution of micro-cracks within a strongly scattering media (concrete, rocks, etc.). Nevertheless, the localization of the cracks using the same techniques is not straight forward. In order to avoid the conditioning and its subsequent relaxation effect related to NR, CWI is simultaneously applied when concrete samples are vibrating in the linear regime. Based on a comparative study of the coda signals contents (non ballistic part) in the absence and under the weak linear vibration, the localization of the mechanically induced scatterers was possible depending on the scatterers' main direction with respect to the vibration plane. The latter point raises the issue of the generated types of vibration at the scatterers. Therefore, investigations were performed using the Acoustic Emission (AE) technique, which has served to verify that the acoustic activity during the linear vibrations does change depending on the considered experimental configuration. The latter, has also a direct effect on the frequency content of the recorded AE hits showing the potential link existing between the quantitative analysis of AE hits and the generated vibration mechanisms of the existing micro-cracks
Toumi, Souad. "Caractérisation des matériaux complexes et de leurs endommagements par la technique de la coda ultrasonore alliée à l'acoustique non linéaire." Electronic Thesis or Diss., Le Mans, 2017. http://www.theses.fr/2017LEMA1024.
Full textNonlinear Resonance (NR) and Coda Wave Interferometry (CWI) have proved to be efficient to detect and follow the evolution of micro-cracks within a strongly scattering media (concrete, rocks, etc.). Nevertheless, the localization of the cracks using the same techniques is not straight forward. In order to avoid the conditioning and its subsequent relaxation effect related to NR, CWI is simultaneously applied when concrete samples are vibrating in the linear regime. Based on a comparative study of the coda signals contents (non ballistic part) in the absence and under the weak linear vibration, the localization of the mechanically induced scatterers was possible depending on the scatterers' main direction with respect to the vibration plane. The latter point raises the issue of the generated types of vibration at the scatterers. Therefore, investigations were performed using the Acoustic Emission (AE) technique, which has served to verify that the acoustic activity during the linear vibrations does change depending on the considered experimental configuration. The latter, has also a direct effect on the frequency content of the recorded AE hits showing the potential link existing between the quantitative analysis of AE hits and the generated vibration mechanisms of the existing micro-cracks
Girard, Gautier. "Caractérisation et modélisation thermomécaniques de matériaux et de structures circuits imprimés complexes destinés aux applications spatiales radiofréquences et micro-ondes." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0170/document.
Full textIn this thesis, the thermomechanical behavior of Printed Circuit Boards with high frequency space applications is assessed. A printed circuit board is a multi-material assembly, linking dielectric substrates and copper paths. The studied PCBs are multilayers, thus drills are made through these layers with copper electrodeposited on the wall of the hole, allowing the electrical signal to go from one layer to the other. Any satellite carries embedded electronics and the PCB is the link and the support of these electronics. During the life of the PCB in space applications, important temperature changes will drive strains which are inhomogeneous in the different materials and thus will lead to important stresses, root of the observed failures. Indeed, the coefficients of thermal expansion of the dielectric substrates are different than the one of copper. For each thermal cycle, the copper undergoes thus an alternate loading. Depending on the configuration, the copper may endure plastic strain and break after hundreds or a few thousands of cycles (oligo-cyclic fatigue). These failures happen often in the copper barrels linking the different layers.Two phases are distinguishable in the thesis: a first phase in which the thermomechanical behaviors of the materials constituting high frequency printed circuit boards is assessed (composites substrates and copper), and a second phase concerning the simulations of crucial configurations thanks to the identified behaviors of the materials
Girard, Gautier. "Caractérisation et modélisation thermomécaniques de matériaux et de structures circuits imprimés complexes destinés aux applications spatiales radiofréquences et micro-ondes." Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0170.
Full textIn this thesis, the thermomechanical behavior of Printed Circuit Boards with high frequency space applications is assessed. A printed circuit board is a multi-material assembly, linking dielectric substrates and copper paths. The studied PCBs are multilayers, thus drills are made through these layers with copper electrodeposited on the wall of the hole, allowing the electrical signal to go from one layer to the other. Any satellite carries embedded electronics and the PCB is the link and the support of these electronics. During the life of the PCB in space applications, important temperature changes will drive strains which are inhomogeneous in the different materials and thus will lead to important stresses, root of the observed failures. Indeed, the coefficients of thermal expansion of the dielectric substrates are different than the one of copper. For each thermal cycle, the copper undergoes thus an alternate loading. Depending on the configuration, the copper may endure plastic strain and break after hundreds or a few thousands of cycles (oligo-cyclic fatigue). These failures happen often in the copper barrels linking the different layers.Two phases are distinguishable in the thesis: a first phase in which the thermomechanical behaviors of the materials constituting high frequency printed circuit boards is assessed (composites substrates and copper), and a second phase concerning the simulations of crucial configurations thanks to the identified behaviors of the materials
Doeuff, Martine. "Matériaux lamellaires MPS ₃ (M = Mn, Cd, Fe, Ni) et chimie de coordination : caractérisation structurale et propriétés de nouveaux composés obtenus par chimie douce." Paris 11, 1988. http://www.theses.fr/1988PA112037.
Full textMoungache, Amir. "Développement d'un banc ellipsométrique hyperfréquence pour la caractérisation de matériaux non transparents." Phd thesis, Université Jean Monnet - Saint-Etienne, 2011. http://tel.archives-ouvertes.fr/tel-00700486.
Full textMnif, Nizar. "Elaboration et caractérisation de mélanges complexes à base de polypropylène en vue de son écoconception et de son recyclage dans les véhicules hors d'usage." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0127/these.pdf.
Full textThis work deals with the elaboration and the study of the properties of blends based on a commercial formulation used in the manufacturing of automotive bumpers. We first worked on the compatibilization of polymers that can be mixed with polypropylene after sorting. Then, we taled to disperse nano-cac03 in the ma taix. The compatibilization of potential polymer pollutants such as abs, pa, pu, led to the elaboration and characterization of blends containing three polymers and a compatibilizer. For (PP/EPR)/abs blends, the presence of sebs as compatibilizer increased the impact strength and the elongation at break (improvement of the matrix/pollutant interface) and decreased the size of abs particles. The blends reinforced with nano-cac03 could contribute to the ecodesign of pp based formulations by substituting non renewable organic raw materials as well as by simulating the presence of nanoparticles that could be mixed with pp matrices after sorting and also by improving the impact strength properties of the initial formulations. The morphological study and the mechanical properties show that the dispersion of nanoparticles in the matrix differs according to the surface properties of the nanofillers (fatty acids including stearic acid). On the other hand, the nano-cac03 preferentially migrate in the EPR phase (compared to pp phase). The presence of pep compatibilizer improves the mechanical properties but epr-g-mah weakens the materials
Bhowmick, Indrani. "Synthèse et caractérisation de matériaux moléculaires magnétiques incorporant des ions métalliques 3d et 4d/5d connectés par des ponts cyanures." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14567/document.
Full textIn this thesis, we have synthesised new cyanido bridged heterometallic molecule-based magnetic materials with the tool of simple donor-acceptor coordination chemistry. The 3d metal ion (MnII/III,FeII, NiII, CuII) based molecular precursors acted as acceptor building blocks, whereas the 4d (RuIII)and 5d (ReIV) trans-cyanido type molecular precursors were used as donor moieties.Chapter I contains a theoretical approach with examples of low dimensional magnetic materials:Single Molecule and Single Chain Magnets that illustrate the role of the cyanido ligand to design such magnetic materials. Furthermore, we emphasized the 4d/5d metal based cyanido precursors for their higher magnetic anisotropy over the 3d metal ions. The choice of molecular precursors, their synthesis and characterization were extensively described in chapter II. In this research work, we have obtained many heterometallic molecular complexes and also one dimensional systems. Chapter III, IV and V contain the synthesis, X-ray crystallographic and magnetic characterization of all the newly synthesized complexes. The close crystal packing of the molecules lead to an antiferromagnetic ground state for most of the complexes and this often perturbed the magnetic relaxation phenomena. As expected, we have found metamagnetic phase diagrams for most of these systems. Some of the ReIV/MnIII and a ReIV/FeII one dimensional compounds exhibited Single-Chain magnet like properties and thus magnetic bistability
Zakhia, Georges. "Synthèse, caractérisation et propriétés magnétiques de nano-aimants moléculaires." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112071.
Full textIn the first part of this thesis, we studied the magnetic anisotropy of pentacoordinated mononuclear Ni(II) and Co(II) complexes possessing geometries from square pyramid to trigonal bipyramid. We have shown that, for a given geometry, the metal ion nature has an important influence on the magnetic anisotropy.Then, we studied for a given metal ion the effect of geometry on its magnetic anisotropy. In the case of a trigonal bipyramidal geometry (C3v symmetry), we showed that Co(II) has an Ising type anisotropy (easy axis of magnetization) and thus a blocking of magnetization that leads to an opening of a hysteresis cycle at low temperature. This type of complexes can be used for storing data albeit at low temperature.In the second part of the work, we studied the magnetic properties of binuclear complexes. A binuclear Co(II) complex bridged by two Cl- has a weak ferromagnetic coupling and a blocking of its magnetization.Finally, another aspect of this work was to design binuclear complexes, where two anisotropic ions having each one an easy axis of magnetization, are weakly antiferromagnetically coupled. To do this, we have studied compounds with cryptand ligands where the geometry around the Co (II) is trigonal bipyramid. We found that with a Cl- or Br- bridging ligand, the exchange interaction is much more important than the local anisotropy of Co(II) ions leading to a magnetic behavior where the ions lose their local character. This work opens up prospects for synthesizing the same type of complex but with larger bridges to decrease the intensity of the antiferromagnetic coupling
Lopes, Leandro. "Étude et caractérisation de matrices hybrides polyether-siloxane utilisées pour la libération contrôlée de Diclofenac de Sodium et de complexes à base de Platine." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112146/document.
Full textThe capacity of hydrophilic (POE) or hydrophobic (POP) siloxane-polyether hybrid matrixes to incorporate platinum based compounds like platinum (IV) tetrachloride (PtCl₄), cisplatin (CisPt), Zeise salt and sodium diclofenac (SDF) was studied. These compounds present academic interest and are applied in cancer disease treatment (CisPt) or catalysis (Zeise salt).The decrease in melting temperature of the semi-crystalline POE1900 hybrid and the decrease of the Tg values together with the Raman results confirm the interactions between SDF and the POE chains of the hybrid matrix. The coexistence of a crystalline and amorphous hybrid phase was clearly evinced by the bimodal drug release pattern achieved for the POE1900 matrix. Optimum amounts for the preparation of homogeneous matrix with CisPt are 5.4% m/m and with PEO1900 1.8% m/m with PPO2000. The local structure of CisPt inside the matrices is preserved. SAXS measurements show that the intensity of the correlation peak between siloxane crosslinks is affected by the CisPt incorporation in the matrix. The observed decrease in intensity without shift in position is interpreted as resulting from the filling of the space between the SiO2 nodes by CisPt. The release profiles of PEO1900 matrices show that the release is independent of the CisPt concentration and that the swelling of the matrix is the dominant process for explaining the release mechanism.For hybrids incorporating (PtCl₄), it has been shown the existence of two Pt entities, a Pt(II) species and a Pt (IV) ones. The Pt(II) species is identified as(PtCl₄)²⁻ whereas the Pt(IV) species is (PtCl₄) dissolved in the matrix. The ratio of Pt(II) and Pt(IV) species is dependent on the matrix nature: The Pt(II) species is dominant for the PEO-based matrices whereas Pt(II) and Pt(IV) proportions are almost equal for matrices based on PPO. It is proposed that the (PtCl₄)²⁻ species interact with the urea groups located at the ends of the polymeric chain and with the by ether groups of the polymer chains. These interactions are facilitated by the anionic nature of the species Pt(II). The neutral species PtCl₄ interact with the matrix in the same way that the CisPt, ie by filling the empty space between the polymer chains. During release essays, the neutral PtCl₄ species is easily released in aqueous solution, the anionic Pt (II) species remaining embedded inside the matrix. As PtCl₄, the Zeise salt is soluble in matrixes giving rise to homogeneous and transparent samples. Raman spectroscopy and EXAFS show that if the Pt-Cl bonds of the hybrid are identical to those found in the Zeise salt,Pt-C₂H₄ vibrations are only identified in the samples after a ageing period. For PEO1900 hybrid matrix loaded with Zeise salt, the formation of metallic platinum was observed during the release essays.The correlation of the structural results gained on the matrices incorporating different platinum molecules with the results of the release assays evidences that the weak interaction of neutral molecules with the matrix is responsible to the fact that the release of CisPt is mainly controlled by the swelling properties of the matrix. The incorporation of anionic Pt species, as (PtCl₄)²⁻ or Zeise salt, gives rise to samples for which the amount of released Pt species are significantly lower than the one obtained for hybrids loaded with CisPt. The strong interactions between the matrix and the anionic species are responsible for the fact that the anionic species is not easily released in solution
Arnould, Amandine. "Caractérisation de nanoparticules en milieux complexes : Applications à des nanoparticules organiques et métalliques." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI098/document.
Full textThe extensive use of nanomaterials has raised awareness about health issues and their fate in the environment. That is why they are now subject to regulation that has imposed their traceability from their manufacturing to their distribution as the establishment of their characteristics (chemical composition, size, agglomeration state, shape ...). A characterization routine for nanoparticles in suspension was developed. Transmission Electron Microscopy (TEM) fulfills most of the criteria cited before by combining imaging and spectroscopy techniques. Three sample preparation methods were optimized to ensure high quality results : a dry process, rapid freezing to vitrify the sample and the use of an textit{in-situ} liquid TEM holder to prevent any preparation artefact (no phase change). To obtain quantitative analysis, a comparison was made between Dynamic Light Scattering (DLS), Multi-Angle Light Scattering (MALS), with and without a fractionation system (AF4), and TEM. To support this work, two nanomaterials were analyzed. The first one is a nanoemulsion composed of lipid nanoparticles stabilized by surfactants used as nanocarriers for drug delivery. Their stability after protein interaction was investigate and some size variations were observed. The second material is a powder composed of titanium dioxide nanoparticles used as UV filters in sunscreens. These nanoparticles were analyzed before and after interaction with UV radiation in a climatic chamber to confirm their stability. The different protocols developed in this PhD may be used for the analysis of other nanomaterials
Tlemsani, Shanez. "Matériaux hybrides organiques-inorganiques lamellaires à base de phosphate de zirconium et de complexes organiques de terres rares : synthèse, caractérisation et étude des propriétés optiques." Clermont-Ferrand 2, 2003. http://www.theses.fr/2003CLF21434.
Full textO'Toole, Niall. "Synthèses et caractérisations de complexes luminescents préparés à partir du macrocycle thiacalix[4]arène et l’ion Mn2+." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1028/document.
Full textThis thesis is a study of the photophysical and photochemical properties of systems containing the molecule sulfonylcalix[4]arene, a member of the thaicalixarene family. A series of studies in our laboratory revealed that a tetranuclear cluster complex of manganese(II) with the ligand para-tert-butylsulfonylcalix[4]arene (thiaSO2) displayed strong red emission under the action of blue light. This surprising discovery became the basis for this doctoral study.The first chapter is a review of the literature concerning thiacalixarenes and their metal complexes. The syntheses and modifications of these compounds will be described, as well as their fundamental properties.The second part is dedicated to the properties of luminescence. In order to propose a mechanistic explanation, the response of the emission arising from the complex (K)[Mn4(thiaSO2)2F] (2) has been studied under varying conditions of pressure, temperature, O2 partial pressure … The hypothesis that these systems are capable of producing singlet oxygen will be made.The third chapter is concerned with photoreactions of these systems in solution. The photo-oxidation of Mn2+ ions into Mn3+ ions was investigated and the various contributing factors to this process will be discussed. The important role of oxygen and its transformation into reactive species, the effect of the solvent and the pH of the reaction medium, and the importance of the starting material, are all confirmed; we will propose a reaction mechanism based on both these data and the photoreactivity inherent to the organic compound calculated by a theoretical method.The final part will show the preparation and characterisation of organic-inorganic hybrid species by the insertion of [Mn4(thiaSO2)2F]- aggregates into LDH (“Layered Double Hydroxide”) materials. These hybrids were obtained by soft chemistry methods. Preliminary investigations of the structure, the luminescence, and the photoreactivity of these products have been made. Finally, an attempt was carried out to test the capacity of these hybrid materials to act as photocatalysts for the oxidation of simple molecules
Warnant, Jérôme. "Synthèse et caractérisation de nanomatériaux fonctionnels siliciques structurés à l'aide de micelles complexes de copolymères séquencés doublement hydrophiles." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2010. http://www.theses.fr/2010ENCM0005/document.
Full textThis study focused on the design and development of new structuring agents of silica constituted of induced and reversible assemblies of original copolymers, the double hydrophilic block copolymers (DHBC). The first system studied consists of a neutral-anionic DHBC PAPEO-b-PAA ou poly(acrylate methoxy poly (ethylene oxide))-b-poly (acrylic acid). The PAA block is a weak polyacid with a degree of ionization depending on the pH. In aqueous solution and in a right pH range, the association of this copolymer with a weak polybase, an oppositely charged polyamine, such as an oligochitosan, leads to the formation of polyion complex micelles (PIC) with a core/corona structure. These micelles can direct the structure of highly organized inorganic materials with different types of mesostructures. In a second step, by adjusting the conditions of pH, ionic strength, it is possible to "control" the extraction of organic species to get functional porous materials able to trap species of charge opposite to the functionality. Organized materials are obtained because of a favourable balance of the interactions between organic and inorganic species. If a polyamine/silica interaction occurs at the expense of the interaction polyamine/DHBC, the mesostructuring process by the micelles is limited. A neutral-cationic DHBC PEO-b-PDMAEMA poly(ethylene oxide)-b-poly(2-(dimethylamine)ethyl) associated with an anionic PVS poly(vinyl sulfonic acid) polymer can play a dual role in the synthesis of silica materials: firstly managing the growth of silica particles by interacting with the silicates and secondly acting as a structuring agent in association with PVS, confering a mesostructuration to the material. Finally, a very promising approach allowed to encapsulate water-soluble and charged drugs in a material by using as silica complexing agent a complex between the drug and a DHBC
Dhaher, Sameh. "L'étude du stockage solide de l'hydrogène et des complexes sigma-dihydrogène." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30230.
Full textAdopting clean and emission- free energy cycle using hydrogen as an energy carrier could be the solution in order to curb the ill effects of energy crisis and global warming on the planet. Thus, the lack of efficient hydrogen storage devices has stimulated the search of new systems. In this manuscript, the dehydrogenation of the bis-dihydrogen ruthenium complex without additives at the ruthenium center has been reported in Chapter II. The unusual and rare dimeric complex bearing two phosphido bridges was accessed from thermolysis of the bis(dihydrogen) complex RuH2(H2)2(PCyp3)2. The complex was characterized by NMR, IR, UV-Visible, X-ray, neutron structure and DFT calculations. Surprisingly, the complex shows a reversible up take and release of H2 at room temperature in solution as well as in the solid state. This is one major criteria for designing a solid hydrogen storage material. The activation of the H-H bond has been subjected to a detailed study in Chapter III. Several novel ruthenium complexes bearing fac-coordinating ligands, 1,3,5-triaminocyclohexane (tach) and 1,4,7-triazacyclononane (tacn) and different anions have been prepared. DFT investigation has been deployed throughout these studies for a fine-level examination of H-H bond activation. An attractive goal in the context of hydrogen storage is to combine magnesium hydride, MgH2 or MOFs to organometallic complexes. This is the purpose of the fourth chapter. Doping magnesium hydride with ruthenium or nickel precursors shows promising results
Dailly, Julian. "Synthèse et caractérisation de nouveaux matériaux de cathode pour piles à combustible à conduction protonique PCFC (Protonic Ceramic Fuel Cell)." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2008. http://tel.archives-ouvertes.fr/tel-00416109.
Full textDans ce cadre, le but de nos recherche a été de concevoir de nouveaux matériaux de cathode pour pile PCFC présentant de bonnes propriétés de conduction mixte ionique et électronique ainsi qu'une activité catalytique élevée vis-à-vis de la réaction de réduction de l'oxygène, entre 400 et 600°C. Plusieurs matériaux à conduction mixte ont été synthétisés à l'ICMCB, notamment des perovskites et des oxydes de structure de type Ruddlesden-Popper (en particulier les oxydes A2MO4+). Des analyses thermogravimétriques ont été réalisées pour étudier la stabilité de ces phases sous air humide, ainsi qu'une éventuelle insertion d'eau dans la structure. Des demi-cellules symétriques ont été élaborées pour les caractérisations éléctrochimiques par spectroscopie d'impédance complexe et voltampérométrie (mesures de résistances spécifiques de surface, courbes de polarisation cathodique).
Les caractérisations physico-chimiques et électrochimiques ont permit de sélectionner les meilleurs composés et ont conduit à la réalisation de la première monocellule PCFC utilisant le matériau de cathode Pr2NiO4+. Des densités de puissance de 100 mW/cm² ont été mesurées pour une température de fonctionnement de 600°C.
Apedjinou, Anoumou. "Cavité de type klystron pour des dispositifs microondes." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0017/document.
Full textThe electrical properties of the materials are essential data in the design phases of microwave circuits. Thus, many methods have been developed based on "S" parameter measurements, for transmission-reflection systems, or resonance frequencies, for resonant methods. Each of them has characteristics adapted to a type of the samplegeometry, to the frequency band of analysis, to a desired precision of the results... In all the cases, the dimensions of the sample must be at least of the order of the wavelength and therefore the characterizations become impossible at low frequencies for samples of small sizes. Another disadvantage of these methods is that it is mandatory to know perfectly the thickness of the sample to accurately determine the electrical characteristics of the material. The objective of this thesis work was therefore to develop a new method of characterization based on a cavity of particular geometry. This allows low frequency measurements for dimensions much smaller than the wavelength. With an original coupling system, we have also been able to obtain a particular transmission response, characterized by a resonance frequency and an antiresonance frequency. Compared to conventional methods that only work on the resonant frequency, this double information makes it possible to determine both the permittivity of the medium but also the thickness of the sample
Ihamouten, Amine. "Caractérisation physique et hydrique de bétons d'ouvrage par propagation d'ondes électromagnétiques." Nantes, 2011. http://www.theses.fr/2011NANT2095.
Full textThe overall objective of this research is to quantify the physicochemical properties of different healthy and degraded concrete structures using non destructive (ND) electromagnetic (EM) techniques, in order to obtain gradients of these properties as a function of depth. Indeed, for a successful diagnosis of concrete structures, it is essential to associate the durability indicators with ND measurement observables. The materials studied are mortars and concretes covering a wide range of porosity and size of aggregates (heterogeneities), healthy at different water contents (homogeneously distributed or with gradients) or damaged by carbonation and chloride penetration. This thesis has three main parts: the first part contains a set of models and innovative methods of treatment related to the EM wave propagation in dispersive media; the second part is devoted to the concrete characteristics, ranging from the modeling of water transfer to the formulation and the characterization of different mixtures of concrete used in this study ; the third part is focused on the analysis of ND method results whether for laboratory measurements or for measurements on real engineering structure
Guellec, Corentin. "Caractérisation en fatigue à grand nombre de cycles par mesures d’auto-échauffement des aciers d’arbres de transmission pour application navale sous chargements cycliques complexes." Electronic Thesis or Diss., Brest, École nationale supérieure de techniques avancées Bretagne, 2023. http://www.theses.fr/2023ENTA0001.
Full textMarine shaft lines undergo complex cyclic loadings. In order to characterize these structures in fatigue, two complementary objectives are achieved. Firstly, the marine shaft’s loads are characterized in order to identify relevant fatigue cycles. During this step, an original parametric fatigue design method is implemented. This method is based on the definition of an equivalent load considering multiaxiality, variability, non-proportionality and mean stress. This method allows to distinguish two damage modes with a mode associated with the established cyclic regime of rotary bending and a mode associated with the ship’s maneuvers. Secondly, a rapid characterization method is implemented to characterize in fatigue the marine shafts’ steels for a large number of loading configurations. The method is based on a model which enables fatigue identification behaviors from self-heating measurements. The steels of the study are characterized in tension-torsion for various configurations of mean stress and nonproportionality of the loading. In this context, the notion of iso-self-heating surfaces is introduced. It allows, for a specimen, to model the elastoplastic and dissipative behavior of the material in the dedicated stress space. Their use makes it possible to define a multiscale fatigue criterion based on the invariants of the stress tensor. In the study, a modeling of the behavior of the material is proposed for very low amplitude loads (VHCF) exhibiting a strong difference in dissipation compared to the regime of higher amplitudes (i.e. HCF domain)
Carn, Florent. "Intégration entre chimie douce et fluides complexes pour la genèse d'architectures poreuses hiérarchisées : synthèses, caractérisations et application." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2006. http://tel.archives-ouvertes.fr/tel-00267831.
Full textBlazy, Jean-Sébastien. "Comportement mécanique des mousses d'aluminium : caractérisations expérimentales sous sollicitations complexes et simulations numériques dans le cadre de l'élasto-plasticité compressible." Phd thesis, École Nationale Supérieure des Mines de Paris, 2003. http://tel.archives-ouvertes.fr/tel-00005740.
Full texttechniques adaptées, être moussé. Il constitue alors un matériau cellulaire aux propriétés spécifiques très
intéressantes notamment en terme de dissipation dénergie lors dimpacts. En combinaison avec dautres structures, comme des profilés par exemple, la mousse daluminium peut former des composites rigides et légers qui constituent une solution nouvelle pour la conception dabsorbeurs de chocs. Cependant, le coût de revient des mousses daluminium, la difficulté à contrôler son processus de fabrication, les
méthodes dintégration, encore peu définies et validées, ainsi que labsence doutil informatique daide à la conception de structures comprenant ces mousses, sont autant dobstacles à leur utilisation effective dans les véhicules de grandes séries. Ces dernières années, les mousses daluminium ont donc suscité un intérêt considérable à la fois auprès de la communauté scientifique mais également auprès des industriels toujours à la recherche de solutions en rupture. Ainsi elles ont été très souvent étudiées du point de vue de leur microstruture et de leur comportement en compression. Les études sous chargements multi-axiaux sont plus rares. Pourtant la compréhension du comportement sous chargement multiaxial de ce matériau reste indispensable dans le but dobtenir un dimensionnement optimisé de structures comprenant ces
mousses. Afin dêtre fiable, ce dimensionnement doit également tenir compte de la grande variabilité du comportement des mousses due à la présence de fortes hétérogénéités microstructurales, mesostructurales voire, dans certains cas, macrostructurales. Lobjectif de cette thèse est de comprendre ces deux aspects et de proposer des modèles aussi simples que possible afin de réaliser un dimensionnement fiable et optimisé. Ainsi, la compression, la traction, le cisaillement, la torsion et des chargements proportionnels ou non proportionnels de traction - compression / torsion ont été étudiés. Pour chaque type de
chargement la dispersion a été caractérisée. Si une distribution de Weibull permet de décrire la dispersion
en traction, lutilisation dune contrainte équivalente couplée à une statistique de Weibull permet de prédire la dispersion pour dautres types de chargements. Lobservation des essais de compression grâce à lutilisation de méthodes de mesure de champs par correlation dimages ou de tomographie à rayon X indique sans ambiguïté que la déformation de la mousse daluminium seffectue avec une forte localisation sous forme de bandes. La prise en compte de la localisation de la déformation dans la modélisation du comportement est réalisée en utilisant la méthodes des éléments finis dans le cadre de la plasticité des matériaux compressibles. Lerreur commise lorsque ces phénomènes de localisation sont ignorés est quantifiée. Un plus grand réalisme peut être atteint encore en considérant lhétérogénéité initiale de la mousse dans la simulation. Enfin une tentative de prise en compte de la connaissance tri-dimenssionnelle
réelle de la structure de la mousse par tomographie dans la modélisation continue est présentée.
Dominguez, Nicolas. "Modélisation de la propagation ultrasonore en milieu complexe : application au contrôle non destructif et à la caractérisation de la porosité dans les matériaux composites stratifiés." Toulouse 3, 2005. http://www.theses.fr/2006TOU30235.
Full textCadra, Stéphane. "Réalisation et caractérisation d'aérogels organiques à fortes teneurs métalliques obtenus à partir d'un complexe de titane polymérisable." Thesis, Tours, 2010. http://www.theses.fr/2010TOUR4041/document.
Full textInertial Confinement Fusion (ICF) is a technique widely studied by the French atomic commission (CEA). Experiments will be performed within the Laser Megajoule (LMJ). They require innovative materials like organic aerogels that constitute laser targets. Such polymeric material must provide both a high porosity and a significant titanium percentage (1 atom %). Moreover, the monomers developed must be compatible with the synthesis procedure already in use. According to these specifications, a new polymerizable titanium complex was synthesized and fully characterized. This air and moisture-stable monomer provides a high metal percentage. Its free-radical cross-linked copolymerization affords several titanium-containing polymers. These gels were dried under supercritical conditions and organic aerogels were obtained. The chemical compositions of these materials were investigated by NMR, IR and elemental analysis while their structure was characterized by MEB-EDS, MET, N2 adsorption/desorption isotherms measurements and SAXS. The data collected fit the specification requirements. Moreover, the mechanisms responsible of the foam nanostructure formation were discussed
Vennat, Maxence. "Synthèse, caractérisation et réactivité de nouveaux complexes du vanadium (V) avec les motifs {VO2}, {VO(O2)} : application à l'oxydation catalytique des cyclanones par le dioxygène et propositions de mécanismes : nouveaux catalyseurs mésoporeux avec le tungstène (VI) et le rhénium (VII)." Paris 6, 2002. http://www.theses.fr/2002PA066363.
Full textMnasri, Faiza. "Étude du transfert de chaleur et de masse dans les milieux complexes : application aux milieux fibreux et à l’isolation des bâtiments." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0169/document.
Full textInternational energy context requires a new orientation to the building sector as in construction or in renovation. Any new solution must be technically efficient and environmentally acceptable. In this thesis, the object is to achieve a numerical and experimental analysis of a building biobased materials. Some of these materials are included from the study of a transborder project to the Lorraine region (France, Belgium and Luxembourg). Indeed an Ecotransfaire project was included in this work. This project has been oriented to the development of a sustainable eco materials chain. A process of analysis has been established in order to select the materials candidates on the basis of scientific, geographical and environmental criteria. The answers are moving towards the integration of bio-based materials. These materials are subject of several heat and mass transfers phenomena. So understanding these mechanisms within a building material has been achieved firstly. This resulted on a coupled model of heat transfer, air, moisture experienced by the HAM model. This model is applied to a wooden building material whose its structure is assumed homogeneous. Then, this model was implemented and solved by the finite element method. Its numerical solution is validated by analytical results available in the literature. The study of sensitivity of the model coupling, dimensions in space, the boundary conditions and the variability of input parameters is also presented. One of the difficulties of using this model is the case of heterogeneous materials. Thus, in this work, we propose an approach of characterization of a heterogeneous lignocellulosic composite material with a porous structure. In fact, this material is composed of two components: Wood and cement. The wood is presented by a shapes aggregates with irregulars sizes and the cement is considered as the binder in the composition. The object was to predict its equivalent intrinsic properties (thermal conductivity and vapor permeability) by using the micro-tomography techniques.The methodology consists to determine the structure of the sample by taking images at the microscopic scale. Once the structure of the sample is generated, we will conduct from a reconstruction of the two-dimensional representation to a three dimensional structure by using a numerical tool which determines the equivalent properties of the 3D reconstructed domain. The permeability as well as the equivalent thermal conductivity are the two properties evaluated in this configuration. These two properties are strongly depend to the porosity and to pore distribution in the continuous phase (the solid one). Moreover the composition of the material and the volume fractions of each components influence the formation of microstructure and consequently the thermal and hydric transfers
Quéffélec, Patrick. "Conception d'une cellule microruban pour la mesure large bande (45 MHz - 12 GHz) de la permittivité et de la perméabilité complexes des matériaux : application à la caractérisation électromagnétique des couches minces dans le domaine des micro-ondes." Brest, 1994. http://www.theses.fr/1994BRES2009.
Full textFlament, Camille. "Caractérisation et identification du comportement d'un matériau composite complexe sous sollicitations thermiques et mécaniques à l'aide de la stéréo-corrélation d'images : Application à l'embrayage." Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0020.
Full textThe clutch facing is an annular shaped continuous fiber composite which transmits the rotary motion from the engine to the wheels. In use it is submitted to thermal and mechanical loadings which can cause changes in the dimensions. New clutch technologies call for a better control of these changes. For the first time, this thesis was dedicated to the understanding of the dimensional stability of the clutch facing. Tensile tests were carried out under different temperature and for different frequencies on small cut specimens or on the entire annular disc. We were then able to identify the elastic and viscoelastic properties as well as the damage mechanisms until failure. The thermal expansion was measured on the entire disc as well. Thanks to digital image stereo correlation and reverse identification methods we were able to describe the coupling between the material's heterogeneities and its annular shape. Finally, this thesis presents the evolution of the material properties after homogeneous thermal cycling
M'Bengue, Marie-Stella. "Conception et évaluation d'une endoprothèse vasculaire par impression 3D pour le traitement des anévrismes complexes de l'aorte abdominale." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILS057.
Full textEndovascular repair (EVAR) of an abdominal aortic aneurysm (AAA) involves the placement into the aneurysm of a stent graft (SG) by minimally invasive surgery. This procedure prevents rupture of the damaged tissue involved in an AAA, defined as a localized diameter dilation of the aorta. When the upstream portion of the aneurysm includes the peripheral renal and/or visceral arteries, the AAA is qualified as complex. In this case, the deployed SG is said “fenestrated”, in other words, perforated at the site of junctions to the peripheral arteries. Management of a complex AAA becomes more limiting as the fenestrated SG will be custom designed to match the anatomy of the aneurysm and the position of the peripheral arteries of the patient. This implies a manufacturing delay of several weeks, limits the management to stable aneurysms and excludes emergency situations. In this context, 3D printing (3DP) is of considerable interest for the fabrication of custom-made SGs in a very short time frame. Thus, the objective of this thesis work is to design a SG prototype by 3D printing of a medical grade thermoplastic polyurethane (TPU) (thermoplastic elastomer). The present work will validate the manufacturing process and the functionality of our 3DP-SG for its final application as an implantable medical device.First, the impact of the manufacturing process on the chemical, physical and physicochemical properties of TPU was studied at each step, from the pellets to the gamma-ray sterilization of a graft manufactured by fused filament deposition (FDM). In vitro preliminary evaluation of the cytotoxicity and hemocompatibility of TPU was carried out after the 3D printing and sterilization step. Aging of TPU under extreme oxidizing conditions was performed to predict the evolution of its properties in the long term. Subsequently, a design strategy for an endovascular implantable prototype was developed. The properties of said prototype were characterized by different techniques (SEC, TGA, DSC, FTIR, SEM, goniometry, uniaxial traction, ...). Its biological properties were evaluated in vitro by tests of cytocompatibility, hemocompatibility and contact with macrophages for 24 hours (acute inflammation). Moreover, the evolution of its physicochemical and mechanical properties was evaluated by in vitro aging studies.The characterization of the chemical, physical and physicochemical properties of TPU enabled the validation of a FDM printing manufacturing route and gamma ray sterilization of a crimpable SG prototype. The in vitro biological evaluation showed the non-cytotoxicity of the SG prototype by the extraction method. Moreover, the prototype was found to be weakly hemolytic and the platelets adhered on its surface were not activated. The low secretion of cytokines (IL-6 and TNF-α) upon contact with inactivated macrophages showed that the SG prototype does not exhibit a pro-inflammatory characteristic. Finally, aging studies showed an impact on the mechanical and surface properties of our SG prototype without compromising its functionality. Subsequently, the design strategy could evolve towards a functionalization of the SG prototype in order to prevent infections and thrombosis responsible for 2% and 6% of postoperative complications respectively
Treuil, Nadine. "Synthèse et caractérisation des composants d'un accumulateur au lithium : électrolytes polymères à conduction Li+, électrodes d'oxydes de lithium et de manganèse." Phd thesis, Université Sciences et Technologies - Bordeaux I, 1998. http://tel.archives-ouvertes.fr/tel-00145597.
Full textKader, Ammar. "Caractérisation et modélisation électromagnétique de multimatériaux composites : application aux structures automobiles." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0056.
Full textThe main concern of this thesis is the characterization of the impacts of some composite materials on the main electromagnetic compatibility issues in a vehicle. The surface models of the dielectric materials are validated by confronting their simulated and measured permittivity. The surface model of the studied conductive material is validated by confronting it to a wire model and by measuring and simulating the S parameters on a structure constituted by such a material. It appears in both cases of dielectric and conductive composite materials that the surface impedance modeling technique gives a good description of the materials. The analysis of the effects of these materials on the EMC issues within a vehicle is done by use of a demonstrator representing the car body. The different equipment and harnesses embedded in a vehicle are represented in the demonstrator by some wires and monopoles. The evaluation of the impact of the composite materials on the EMC issues is done by measuring and simulating the different couplings within the demonstrator and between the demonstrator and a test antenna. The analysis of the different couplings confirms that the surface impedance material modeling approach describes well the materials under test. Concerning the impact of the composite materials on the EMC issues at a vehicle level, this analysis fulfills two main results. The first one concerns the dielectric materials. Indeed the use of these materials increases the different coupling by a value varying between at least 5 dB to 30 dB. The second conclusion concerns the use of conductive composite materials. It appears that they have no effect on the different couplings in comparison to the full steel structure
Barbusse, Danielle. "Contribution à la caractérisation des matériaux : étude des couches minces, multicouches et superréseaux III-V et II-VI par double diffraction des rayons X (composition, qualité, contraintes) : étude structurale par absorption X au seuil K d'une série de complexes du cobalt et du fer, XANES et EXAFS de laboratoire." Montpellier 2, 1991. http://www.theses.fr/1991MON20189.
Full textPons, Aenor. "Elaboration, caractérisations et modélisation des mécanismes de conduction de matériaux céramiques conducteurs anioniques et protoniques." Thesis, Limoges, 2014. http://www.theses.fr/2014LIMO0035/document.
Full textFouassier, Patrick. "Modélisation électrique des composants magnétiques haute fréquence : prise en compte de la température et caractérisation des ferrites." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0108.
Full textThe increase of working frequencies in static converters used in power electronic applications requires a more realistic modeling of magnetic componems. The lumped équivalent electrical circuit assîgned to a comportent has about twenty éléments, derived by extemal impédance measurements only. This équivalent circuit, designed with a rigorous theoretical and expérimental approach, and quickly worked out using well ada^ted computer tools, enables ail the physical phenomena to be represented from DC to one or two décades beyond its operating frequency. A uniform température study has shown that the prédiction of the electric behavior of a transformer at any température, from its characterization at ambient température only, was possible for windings. On the other hand, suoplier data remain insufficient to correctly quantify the behavior of magnetic core. Moreover, résistances placed on the équivalent circuit to represent losses of the component hâve been validated by calorimetry. Thus, they allow dissipations to be determined with fine accuracy for a given source and load. To better characterize high frequency magnetic materials in the absence of complète and reliable data from ferrite manufacturers, a new origina! method has been developed. With this method requiring some expérimental précautions, simple analytical relations lead to the déduction of both complex permeability and complex permittivity at each frequency and uniform température. It also gives parameters applicable to any geometry of magnetic core and accounts for ail the physical phenomena occurring in the material when the frequency increases, notabiy the capacitive behavior that can be noticed in MnZn ferrites above tens of kHz. This method allows îron losses to be computed up to 10 MHz
De, Rousiers Charles. "Rendu réaliste de matériaux complexes." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00648850.
Full textRousiers, Charles de. "Rendu réaliste de matériaux complexes." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENM055/document.
Full textReproducing efficiently the appearance of complex materials is a crucial problem in the synthesis of realistic images widely involved in the production of video games and movies. Apart from global light transport, the realism of a synthetic image is in large part due to the adequate modeling of local light transport, i.e. the interactions between light and matter. Modeling these interactions gives rise to a large variety of reflectance models. We therefore propose a classification of these models based on the scales of their abstract geometric details. From this classification, we can study particular reflectance models: a transmitting reflectance model for transparent rough surfaces such a frosted glass. The efficiency of our model allows real-time performances, a study and a model of energy propagation in material composed of dense packed discrete particles, an alternative basis for representing and lighting efficiently measured materials having a low frequency reflectance. These models permit the abstraction of local interactions while keeping the realism of fully simulated local light transport models
Martin, Pauline. "Plasticity and damage mechanisms in specific multiphased steels with bainitic matrix under various mechanical loading paths : influence of temperature." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC227.
Full textThis PhD work investigates plasticity and damage mechanisms of complex phase steels. The bainitic microstructures of such steels, which feature retained austenite islands, result in these steels exhibiting good formability properties, which are of interest to automotive companies. However, the complexity of these microstructures, which are characterised by a high amount of grain boundaries and a high density of dislocations, influences plasticity and damage mechanisms. In order to estimate the impact of a steel's microstructure on these properties, the investigation of metallurgical features of complex phase steels provided by the company Faurecia is performed. Plasticity mechanisms are then investigated by tension-compression tests to determine the influence of long- and short-range interactions on the motion dislocation. Thereafter, the evolution of damage within microstructures is analysed at different stress triaxialities in order to obtain the volume area fraction and the number and average diameter of voids as functions of plastic strain. Finally, to examine the thermal stability of these parameters (microstructure, plasticity, and damage), experiments are performed at a range of temperatures between 20°C and 600°C
Privas, Edwige. "Matériaux ligno-cellulosiques : "Élaboration et caractérisation"." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2013. http://pastel.archives-ouvertes.fr/pastel-00933754.
Full textHaj, Khlifa Karim. "Caractérisation électromagnétique des matériaux diélectriques et magnétiques." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENT067.
Full textThe development of wireless applications leads to an increasing demand of electronic broadband components. Inductances and transformers are key components for power management and communication stages. The knowledge of the electric behaviour of the magnetic materials is critical especially when broadband applications are concerned. The objective of this thesis is to develop techniques to characterizing materials deposed by inkjet process
Troalen, Jean-Pierre. "Caractérisation ultrastructurale et comportement des géo matériaux." Vandoeuvre-les-Nancy, INPL, 1992. http://www.theses.fr/1992INPL042N.
Full text