Tesis sobre el tema "Microscopie micro-ondes à balayage"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Microscopie micro-ondes à balayage".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Sellami, Leila. "Analyse micromécanique des matériaux par Microscopie Micro-ondes à Balayage (SMM)". Electronic Thesis or Diss., Troyes, 2024. http://www.theses.fr/2024TROY0005.
Texto completoNon-destructive testing constitutes a major challenge in research on metallic materials. Indeed, taking into account the mechanical state of the finished component but also throughout the manufacturing process is necessary to best control the design, optimize the performance and service life of the product without destroying components and wasting materials, all in a context of cost reduction and sustainability.A new non-destructive analysis technique using near-field microwave microscopy, based on the variation of electromagnetic fields interacting with materials, has been developed particularly for measuring local micromechanical changes on very small parts. With a lateral resolution of the order of a nanometer, it is entirely suitable for small-scale measurements (nm to mm). It also offers the possibility of obtaining a depth gradient by skin effect depending on the frequency of the signal.This thesis aims to identify the mechanical origin of the microwave signal obtained by this technique on different metals by experimentation (comparison to other analysis techniques) and modeling.In general, the experimental work made it possible to better understand the impact of the mechanical state and to differentiate the effect of a stress (elastic regime) from the effect of a plastic strain on the measured signal. The modeling work has provided a better understanding of the interactions involved
Haenssler, Olaf Christian. "Multimodal sensing and imaging technology by integrated scanning electron, force, and near-field microwave microscopy and its application to submicrometer studies". Thesis, Lille, 2018. http://www.theses.fr/2018LIL1I006.
Texto completoVarious disciplines of micro- and nanotechnology requires combinatorial tools for the investigation, manipulation and transport of materials in the submicrometer range. The coupling of multiple sensing and imaging techniques allows for obtaining complementary and often unique datasets of samples under test. By means of an integrated microscopy technique with different modalities, it is possible to gain multiple information about nanoscale samples by recording at the same time. The expansion with nanorobotics and an open-source software framework, leads to a technology approach for semiconductor research and material science. This work shows the potential of such a multimodal technology approach by focusing on a demonstrator setup. It operates under high-vacuum conditions inside the chamber of a Scanning Electron Microscope and serves as a technology platform by fusing various microscopy modalities, techniques and processes. An Atomic Force Microscope based on a compact, optical interferometer performs imaging of surface topography, and a Scanning Microwave Microscope records electromagnetic properties in the microwave frequency domain, both operating inside an SEM. A software framework controls the instrument. The setup allows for observing with SEM, while imaging and characterizing with interacting evanescent microwaves and intermolecular forces simultaneously. In addition, a multimodal test standard is introduced and subsequently confirms the functionality of the demonstrator. Within this context, the work also includes an electrical analysis of micro-scale MOS capacitors, including an approximation for use in the calibration
Lucchesi, Marie Elisabeth. "Extraction sans solvant assistée par micro-ondes : conception et application à l'extraction des huiles essentielles". La Réunion, 2005. http://tel.archives-ouvertes.fr/tel-00118895/fr/.
Texto completoSolvent-Free Microwave Extraction (SFME) is a new extraction process developed at thé Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments of Université de La Réunion. SFME is a combination of traditional extraction technique and an innovative technology, microwave heating. When we compared SFME and HD oil extraction on aromatic herbs and spices, we found that, herb extraction times from leaves are greatly reduced (up to seven times less) using SFME, spice yields are higher using HD. However, substantially higher amounts of oxygenated compounds, thé most valuable in terms of fragrance, are présent in thé essential oils extracted by SFME when compared with HD. Scanning Electronic Microscope techniques showed that using microwaves contributes to an almost instantaneous release of essential oils from thé glandular hairs and cells. Différence in essential oil composition between ESSAM and HD could be explained by solubility phenomena
Nguyen, Tran Phong. "Progrès en thermométrie quantitative aux échelles micro et nanométriques par microscopie thermique à balayage (SThM)". Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCD010/document.
Texto completoThermal characterizations at nano-scale remain a challenge since the emergence of nano-structured devices. Having advantages in term of lateral resolution compared to far field techniques, the scanning thermal microscopy has become an essential tool for local materials heat transport characterization. In the frame of the European Quantiheat Project, several laboratories have worked together trying to figure out and to obtain quantitative thermal measurements covering spatial scales from the micrometre to the nanometre.This document contains six chapters with four main parts, in which micro-wire thermocouple based SThM probes have been used to enhance our knowledge in quantitative thermometry at this scale. This kind of probe has been developed and improved for several years. We demonstrate that it is adapted for measuring temperature of active samples as well as thermal conductivity of passive samples.Through the dissertation, the last version of the microscope (hardware, software) and probe design are presented. Attached on a quartz tuning fork, the tip-sample contact force can be quantified. Placed in a vacuum chamber, this system permits a full control of predominant parameters on the measurement such as air pressure and contact force. Thanks to samples provided by Quantiheat partners, measurements in active and passive modes have been performed to demonstrate that quantitative measurements are feasible. By changing ambient conditions from primary vacuum to ambient pressure, the tip-sample heat transfer mechanisms have been analysed in detail to reveal the preponderant role of air and solid-solid contact conductions
Lucchesi, Marie-Elisabeth. "Extraction Sans Solvant Assistée par Micro-ondesConception et Application à l'extraction des huiles essentielles". Phd thesis, Université de la Réunion, 2005. http://tel.archives-ouvertes.fr/tel-00118895.
Texto completoA titre de comparaison, les huiles essentielles de plantes aromatiques fraîches et d'épices sèches ont été extraites par l'ESSAM et par une technique plus traditionnelle l'HD. Concernant les plantes aromatiques fraîches, les rendements sont identiques à ceux obtenus en HD et les temps d'extraction sont divisés par sept. Pour les épices, les rendements sont meilleurs en HD. La fraction en composés oxygénés, réputée pour être la plus valorisable au niveau olfactif, a une teneur toujours supérieure en utilisant l'ESSAM.
L'observation au Microscope Electronique à Balayage (MEB) des végétaux (feuilles ou graines) soumis à l'ESSAM et à l'HD a mis en évidence la spécificité de l'ESSAM au niveau des mécanismes de libération et d'extraction des molécules aromatiques au sein du végétal. L'effet des micro-ondes a pour conséquence une libération plus rapide de l'huile essentielle contenue dans la plante grâce à l'ouverture quasi instantanée des glandes et poils sécréteurs. L'explication de la différence de composition chimique entre les procédés d'extraction par HD et par ESSAM pourrait être basée principalement sur des phénomènes de solubilité.
Romero, Leiro Freddy José. "Poly-articulated microrobotics for correlative AFM-in-SEM microscopy". Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS520.pdf.
Texto completoCorrelative microscopy is the result of the combination of two or more microscopy techniques to provide complementary information on a sample. When using a scanning electron microscope (SEM) and an atomic force microscope (AFM), AFM-in-SEM correlative microscopy not only enables the 3D characterization of samples observed inside a SEM, but also the manipulation of micro- and nanostructures with an extremely high precision. This technique can be applied to various samples in biology, electronics and materials science. Although existing AFM-in-SEM solutions in the current state of the art are powerful, they require expert users; they are not versatile enough to be used for different types of tasks; and they use Cartesian AFM robots that severely limit the dexterity and performance of the imaging system. The aim of this thesis is to study and experiment an original concept of an AFM based on poly- articulated robotics for AFM-in-SEM correlative microscopy. A homemade 6 DoF (3 translations and 3 rotations) robotic AFM system is developed and integrated inside a SEM. The ability to control 3 positions and 3 rotations of a micrometer sized AFM probe while keeping the center of rotation at the close proximity of a micro-structure is very challenging. This is mainly due to the uncertainties inherent to the assembly of micro-robotic systems and clearances in the joints of the robot that are of the same order of magnitude as the required AFM probe positioning accuracy. Robot calibration methods and control theory can however overcome these limitations as demonstrated in the thesis. Control strategies and a user interface are studied to operate the multi DoF correlative imaging system in a versatile and intuitive way for low-level end users while keeping it enough powerful for high-level end users. Several key features that go beyond the state of the art are implemented, including - Vision based control for fast and automated landing of an AFM probe on a micrometer sized sample with robustness with respect to the SEM magnification. The user can select any region of interest (ROI) on a sample by simply performing a mouse click on the SEM screen. Whatever the SEM magnification, the control algorithm ensures a safe landing of the AFM probe on the ROI. The surface of the sample can be as high as several square centimeters and the positioning can be achieved with a micrometric precision. - In-plane and out-of-plane rotation of a sample relatively to the AFM probe while keeping the center of rotation around the tip of the AFM. The center of rotation is defined by the user with a mouse click on the SEM screen. This feature is useful for manipulation and topography tasks, as well as for multi-angle observations of a sample inside a SEM. - Trajectory/speed selection modes. Low speed AFM mode for a detailed topography imaging. Fast AFM mode (4fps) for dynamic observations at the nanoscale. The users also have access to the control parameters. They can be modified to suit their needs. - Mosaic AFM mode to extend the topography scanning area inside a SEM. All these features rely on research works in robotics, mechatronics and control made during the thesis. The latter has the potential to opens the door to a new era of poly-articulated atomic force microscopes used in correlative microscopy
Ktari, Nadia. "Lithographie de surfaces isolantes par microscopie électrochimique pour l'immobilisation d'objets micro et nanométriques". Phd thesis, Université Paris-Diderot - Paris VII, 2011. http://pastel.archives-ouvertes.fr/pastel-00623048.
Texto completoMarturi, Naresh. "Vision et asservissement visuel pour nanomanipulation et nanocaractérisation en utilisant un microscope électronique à balayage". Phd thesis, Université de Franche-Comté, 2013. http://tel.archives-ouvertes.fr/tel-01025318.
Texto completoBouillard, Jean-Sébastien. "Microscopie en champ proche optique à base de micro pointes optiques en polymère : développement et applications". Troyes, 2007. http://www.theses.fr/2007TROY0005.
Texto completoAfter classifying the various probes used in near field optics, we present a new polymer probe for field optics microscopy. We describe its fabrication and its major optical characteristics and then present the improvements that can be made to those probes in order to enhance their resolution. In order to use those new probes, we developed a scanning near field optical microscope (SNOM) using a regulation system based on a quartz tuning fork. We present the experimental apparatus concentrating ourselves on the development of the regulation system. We then expose some chosen results obtained with the polymer probes. We thus present two luminescence studies : a study of a nanostructured luminescent sample which allowed us to determine the resolution of the probe used, and a study on the luminescence of optically nanostructured porous silicon. Next we present results obtained on guided optics and optoelectronics samples : a mode study on a vertical cavity surface emitting laser (VCSEL), and a new method for mapping the refractive index inside a guiding structure, and finally we observe modes propagating through an optical waveguide which allowed us to test yet another aspect of the polymer probes. Lastly, we present a study of the coupling between fluorophores and metal nanoparticles
Bélier, Benoît. "Développement de micro-leviers à fonctions optiques intégrées pour la microscopie à effet tunnel photonique et la microconnexion optique". Montpellier 2, 1999. http://www.theses.fr/1999MON20145.
Texto completoCui, Le. "Robust micro/nano-positioning by visual servoing". Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S005/document.
Texto completoWith the development of nanotechnology, it became possible to design and assemble nano-objects. For robust and reliable automation processes, handling and manipulation tasks at the nanoscale is increasingly required over the last decade. Vision is one of the most indispensable ways to observe the world in micrioscale and nanoscale. Vision-based control is an efficient solution for control problems in robotics. In this thesis, we address the issue of micro- and nano-positioning by visual servoing in a Scanning Electron Microscope (SEM). As the fundamental knowledge, the SEM image formation and SEM vision geometry models are studied at first. A nonlinear optimization process for SEM calibration has been presented considering both perspective and parallel projection model. In this study, it is found that it is difficult to observe the depth information from the variation of the pixel position of the sample in SEM image at high magnification. In order to solve the problem that the motion along the depth direction is not observable in a SEM, the image defocus information is considered as a visual feature to control the motion along the depth direction. A hybrid visual servoing scheme has been proposed for 6-DoF micro-positioning task using both image defocus information and image photometric information. It has been validated using a parallel robot in a SEM. Based on the similar idea, a closed-loop control scheme for SEM autofocusing task has been introduced and validated by experiments. In order to achieve the visual guidance in a SEM, a template-based visual tracking and 3D pose estimation framework has been proposed. This method is robust to the defocus blur caused by the motion along the depth direction since the defocus level is modeled in the visual tracking framework
Kustov, Mikhail. "CARACTERISATION ET CONCEPTION DE MICRO-AIMANTS POUR LA LEVITATION DIAMAGNETIQUE DE MICRO- ET NANO-PARTICULES". Phd thesis, Université de Grenoble, 2010. http://tel.archives-ouvertes.fr/tel-00578044.
Texto completoAbdoune, Fatima-Zohra. "Dispersion de nano- et micro-domaines de cristal liquide dans des matrices polymères". Lille 1, 2006. http://www.theses.fr/2006LIL10163.
Texto completoPellissier, Marie. "Développement d'une pile à combustibles biologiques fonctionnelle en milieu biologique : optimisation des constituants des électrodes et analyse de leurs fonctionnements par micro-électrochimie". Rennes 1, 2008. http://www.theses.fr/2008REN1S109.
Texto completoBiocatalytic fuel cells are devices which rely upon biocatalytic reactions at the electrodes to convert chemical fuels and oxidants into electrical power. The long-term goal is the design of a small, implantable, and long-lived, low power source for biomedical applications. A lot of different strategies are developed in order to improve the devices, particularly their voltage and their power output. However, the main drawback to obtain an implantable device is the very low stability in time of the biofuel cells, which should be about a few years instead of a few days. Moreover, the prototypes generally have not been really characterized: this limits the understanding of the catalytic systems. The fist part of this work relates to the construction of stable catalytic electrodes. Our method uses two methods: the covalent grafting and the formation of enzymes hydrogel. Our modified electrodes have a catalytic activity stable during 6 weeks. The second part of this work relates to the characterization of electrodes modified with enzymes using scanning electrochemical microscopy (SECM). The first study refers to micro-patterned surfaces as the functionalization is the first step of the preparation of biocatalytic surfaces. The second study refers to enzyme-modified conducting surfaces and the last to enzyme-modified insulating surfaces
Bataillon, Jean-Luc. "La métrologie des circuits intégrés par microscopie électronique". Grenoble INPG, 1990. http://www.theses.fr/1990INPG0001.
Texto completoMarchetti, Maxime. "Étude et réalisation de micro-antennes pour l'acquisition du champ électromagnétique rayonné par des circuits intégrés radiofréquences à des distances sub-micrométriques : mise en oeuvre sur une station de caractérisation sous pointes pour l'acquisition du champ sur plaquette de silicium". Montpellier 2, 2005. http://www.theses.fr/2005MON20128.
Texto completoAbrahamians, Khanghah Jean-Ochin. "Quartz probes for embedded micro-robotics and imaging". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066130/document.
Texto completoAs self-sensing and self-exciting tools, quartz probes present many advantages over the heretofore dominant silicon cantilevers for mechanical micro-sensing applications. One of these advantages is that they can be embedded and calibrated without the need for a laser deflection setup. The more compact and self-sufficient tools can therefore be readily integrated and controlled with Scanning Electron Microscopy, which is favoured at the smaller scales of micro-robotic research. More generally, the development and use of quartz probes is bolstered by the fact that they can be fabricated from widely commercialized quartz components and customised through the addition of a microtip. The quartz probes found in the literature are however largely based on components with limited oscillation frequencies, and could benefit from higher operating speeds. In this context, we address the frequency improvement and embedded control of AFM probes with regard to their use in targeted micro-robotics and imaging. The properties of quartz probes are first covered towards the evaluation and use of higher frequency components; we next demonstrate that faster scanning can be achieved with quartz probes made from thickness shear resonators, making them suitable for fast applications which do not require high sensitivity. Lastly, we integrate a tuning fork probe inside a SEM, and establish through it a proof of concept for the non-destructive stiffness mapping of fragile micro-membranes
Grimont, Laure. "Microscope à effet tunnel photonique PSTM utilisant les sondes semi-conductrices à force atomique". Montpellier 2, 1997. http://www.theses.fr/1997MON20197.
Texto completoLahimer, Selim. "Etude de mécanismes d'interactions entre une pointe de microscopie AFM et une surface de semiconducteur". Montpellier 2, 1997. http://www.theses.fr/1997MON20110.
Texto completoTillous, Kessein Éric. "Contribution à l'étude de l'aluminium et ses alliages 2214-T6 et 7050-T74 transformés par oxydation micro-arcs (OMA)". Vandoeuvre-les-Nancy, INPL, 2006. http://docnum.univ-lorraine.fr/public/INPL/2006_TILLOUS_K_E.pdf.
Texto completoThe process of micro-arcs oxidation (OMA), whose principle is based on that of traditional anodization, applies to a group of metals and their alloys (Al, Mg, Ti, Zn, Nb, Ta, Hf, W, Sb, Mo, Bi). The specificity of this process lies in the participation of discharges or micro-arcs (followed by a gaseous emission) in the formation of the coating by conversion of the substrate. The discharges cause the formation of a coating made up of alumina whose properties are considerably different from those of layers obtained by traditional anodization. After a review about traditional anodization and micro-arcs oxidation, this work tackles the characterization of OMA coatings by several techniques: optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) and electron probe microscopy analysis (EPMA) with wave-length dispersive spectrometry (WDS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and microtomography. Each technique of analysis produces complementary results making it possible to look deeper into the understanding of the growth mechanism of the three layers of the coating: porous outer layer, dense inner layer and the so called “barrier layer” at the coating / substrate interface. An assessment of the coating morphology can be suggested from the appearance of the surface treated in silicate bath. The defects of OMA coating are revealed. Correlations are established between the parameters of treatment (density and frequency of the current, ratio of negative to positive charge quantity applied to the electrode (qn / qp) and duration of the treatment), the nature of the substrate and the coating features (proportions of defects, various types of alumina, thickness of the layers) From these results of characterization, a model of the discharges formation and coating growth is proposed in the case of an aluminium alloy
Friedt, Jean-Michel. "Etude et réalisation d'un micro-nano manipulateur avec retour de force : contribution à son intégration dans une plateforme multicapteurs". Phd thesis, Université de Franche-Comté, 2000. http://tel.archives-ouvertes.fr/tel-00509641.
Texto completoBeyer, Matthieu. "Elaborations et caractérisations d'auto-assemblages dipolaires par microscopie à effet tunnel". Thesis, Besançon, 2015. http://www.theses.fr/2015BESA2056/document.
Texto completoThis work is dedicated to the investigation under ultra high vacuum of _-conjugated molecule on a silicon surface by means of scanningtunneling microscopy (STM). The manuscript consists of five chapters.In the first chapter, we present a state-of-the-art of organic assembly on metal and semiconductor.Chapter two describes the experimental setup using during thesis. It also shows Si(111)-B substrate and gives theoretical conceptsassociated with the scanning tunneling microscopy.The third chapter describes in detail the supramolecular network obtained from an aromatic halogenated molecule with C2 symmetry. Theadsorption of 4,4"-dibromo-p-terphenyl leads to the formation of two kinds of compacts structures (a stripe structure and a herringbonestructure). The formed networks are stable at room temperature and commensurable with the surface. These architectures are promotedby hydrogen bond, halogen bond and _-stacking.Chapter four studies influence of benzene ring number on the geometry and the periodicity of self-assemblies on Si(111)-B. To do that,we have synthesis two organics molecules composed of an aromatic central part and two laterals chains (O-(CH2)9-CH3). The centralpart is composed of respectively three or five phenyl ring ended by cyano groups. We are also interested to the terminal groups effecton the network organisation. We show that the cyano groups effect on the "molecule/molecule" interaction and the "molecule/surface"interaction are negligible. Basis of the work conducted on the chapter four, we conclude our manuscript by presenting supramolecularsnetworks of dipolar molecule. These networks form dipole lines. We show that on small scale the molecules promote an alignment of theirdipolar moments
Lee, Alex Yi-Chuang. "Les micro-usures dentaires des fossiles humains du sud-est asiatique : implications en terme d'environnement et de subsistance". Paris, Muséum national d'histoire naturelle, 2006. http://www.theses.fr/2006MNHN0016.
Texto completoDental microwear study has been applied in palaeoanthropology, archaeozoology, primatology etc. For the reconstruction of ancient diet and environmental adaptation for more about 30 years. The classical method uses the SEM to record the teeth surfaces’ images and analyze them in different ways. New 3D technology has been adopted recently to record teeth surface in microroughness parameters. The buccal surfaces of 69 molars of south-eastern Asian hominids have been analyzed in this study. Only a few of them conserved the occlusale surface. Our objectives include: (1) to observe the inter-group variations of the samples; (2) to infer the relation of the dental microwear and the type of subsistence; (3) to standardize the research protocol of the application of 3D microroughness technology. We have applied the classical method and the 3D technology. A new protocol and the S series amplitude parameters of microroughness analysis adopted in current study are firstly applied in dental microwear study. The results show a high accordance between two methods. The grouping according to the environmental difference but not taxonomic difference is significative in the Javanese Homo erectus and Homo sapiens samples. The abrasiveness of the diet between groups is also distinct
Naessens, Martine. "Contribution a l'écotoxicologie analytique par des cellules végétales, applications en microscopie et a la réalisation de biocapteurs". Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 1998. http://tel.archives-ouvertes.fr/tel-00841313.
Texto completoHuvier, Corine. "Consolidation de poudres métalliques par compression isostatique et chocs laser : microstructures et propriétés d'agglomérés obtenus avec des poudres de cuivre allié". Poitiers, 1994. http://www.theses.fr/1994POIT2266.
Texto completoWei, Xin. "Etude micro-macro de la fissuration des argiles soumis à la dessiccation". Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2014. http://www.theses.fr/2014ECAP0013/document.
Texto completoThe objective of this research is to analyze the appearance and propagation of cracks related to desiccation and to provide a better understanding of the relation between the macroscopic and microscopic behavior of five clays, a kaolinite, a montmorillonite and three mixtures of kaolinite and montmorillonite. At the macroscopic scale, the method is based on (1) measurements of water content, void ratio and degree of saturation versus suction during drying, which allows to specify the relationship between shrinkage and desaturation and highlights the characteristic phases of behavior; (2) measurements of water contents and global deformations in free desiccation tests in order to study their homogeneity; (3) the determination of the local deformations and displacements during drying using the softwares VIC-2D and VIC-3D; (4) a classical study of the parameters of cracks; (5) traction tests in order to identify the tensile properties of the clays involved in the formation of cracks. At the microscopic scale, the study is based on a thorough microstructure analysis using in particular scanning electron microscope, coupled to an adapted method for the identification of preferential orientations of particles. This microscopic study is complemented by mercury intrusion porosimetry analysis, a method which allows to quantify the poral space and to characterize the local void ratio. In addition to the research on clay soils, the effects of decompression and suction on the formation of cracks in a clay rock were analyzed too. The relationship between macroscopic changes and the changes in the microstructure and porosity was investigated. During free desiccation tests, two-dimensional strains and displacements maps are obtained with Vic-2D. The zones of the sample where cracks appear are identified as well as the evolution of strains and displacements before the appearance of cracks. At the end of desiccation, the cracks form a kind of network. Bifurcation of cracks can be observed in some cases. Two modes of cracks are detected during the tests: traction mode and tearing mode. When a crack is caused by traction, the propagation direction follows the direction perpendicular to maximum extension. If there are shear strains in the vicinity of the crack, then its direction changes. In the early time of desiccation, the displacements and strains on the boundaries are larger than those in the other parts of the model. In the vicinity of cracks, displacements and strains are relatively larger than those in the other parts. In most parts of the model, the principal strains are mainly longitudinal and transversal. For a given material, tensile strength increases when water content decreases. Plotting the results versus the liquidity index allows highlighting the effect of mineralogy on tensile strength. At the same liquidity index, the maximum tensile stress decreases when the montmorillonite content increases. The effect of suction on tensile strength seems qualitatively similar to what is observed in the case of unconfined compression strength with tensile strength being a linear function of the logarithm of suction. Analysis with SEM of four slurries submitted to several suctions highlights the global isotropy of the microfabric, with a random orientation of the particles, while a finer analysis reveals that the fabric may present locally some anisotropy
Gaudenzi, de faria Marcelo. "Robust control for manipulation inside a scanning electron microscope". Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2068/document.
Texto completoThis work studies the nano-positioning problem inside the scanning electron microscope (SEM). To acquire fast and accurate positional information, a dedicated setup was implemented consisting of a vibrometer placed inside the SEM. This approach differs from methods based on image processing, as it allows to capture real-time data on the dynamic behavior of structures. In a first study, the mechanical disturbances acting inside the microscope’s vacuum chamber were characterized and its sources were identified. This demonstrated how external mechanical vibrations and acoustic noises can largely influence the components inside the SEM through mechanical coupling, limiting the effective positioning precision of manipulators. Next, a commercial micro-gripper was studied, both in air and in vacuum, and the differences between its response were highlighted. This allowed to obtain two dynamic models for this end-effector, one for each environment. Two control laws were proposed (H-infinity control and Extended State Observer based control) for the system, to obtain a real-time, precise positioning in the vacuum environment and to attenuate the effects of the external mechanical disturbances. Results were demonstrated through simulation and experimental validation
Poucques, Ludovic de. "Caractérisation d'une décharge micro-onde pulsée dans le mélange CH4-H2 en vue de son optimisation pour la synthèse de films de diamant". Nancy 1, 2000. http://www.theses.fr/2000NAN10126.
Texto completoOwing to its very good physico-chemical properties, diamond is an excellent candidate for applications in optics and in electronics intended to work in hard conditions (high power, high frequençy and high temperature). These applications need high purity diamond to be synthetize. As a consequence, many research works showed that Microwave Plasma Assisted Chemical Vapour Deposition (MWPACVD) is the most suitable process for diamond films deposition. The original aspect of this work concerns the study of the influence of pulsed microwave dis charge parameters - especially the power pulse duration and repetition rate- on the plasma reactivity and the diamond layer properties. Sample characterization was carried out by means of Scanning Electron Microscopy and Raman Spectroscopy. These analyses allowed us to show that an optimum in diamond film quality is reached, without lowering the film growth rate, when both the microwave pulse duration and the afterglow are fixed at 1 ms. The plasma diagnostic was perfomed by using Time Resolved Optical Emission Spectroscopy (TROES), Laser Induced Fluorescence (LIF) and the "double pulse technique" that allows the ground state of species to be re-excited during the afterglow. The influence of the time parameters of the plasma on the gas phase composition was correlated to the modification in the diamond film properties. The time and space resolved study of the main reactive species shows that a gooq adjustment of the power pulse duration and repetition rate allows the concentration of these species to be controlled. Furthermore, we point out that the main processes which govern such pulsed plasma are thermal effects (heating and cooling of the neutral gas) and diffusion to the walls. These points make necessary the time and space resolved plasma characterization
Daffé, Khadim. "Caractérisation hyperfréquence sous pointes de nano-dispositifs : métrologie et instrumentation". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1I080/document.
Texto completoIn the frame of the spectacular development of nano-objects, innovative on-wafer electrical measurement methods must be addressed at the nanoscale. In particular, two main issues have been identified. On one hand, nano-devices exhibit very high dynamic impedance in contrast with conventional measuring microwave instruments. On the other hand, there is an inherent size discontinuity between nano-objects and conventional measurement systems. Given the scientific challenge and a relatively limited state of the art, several avenues of investigation have been explored. First, as part of a European project bringing together metrology laboratories, and the joint laboratory IEMN-STMicroelectronics®, the traceability of nano-devices high impedance measurements is established. In a second step, the development of an electrical on-wafer measuring platform for nano-devices is described. This includes the development of new generations of GSG (Ground-Signal-Ground) miniaturized probes in MEMS (Microelectromechanical systems) technology with reduced access pads. The probes are mounted on a robotic nano-positioning platform integrated in a scanning electron microscope
Zill-E-Huma, Huma. "Hydrodiffusion assistée par micro-ondes : nouvelle technique d'éco-extraction". Phd thesis, Université d'Avignon, 2010. http://tel.archives-ouvertes.fr/tel-00547428.
Texto completoFriedt, Jean-Michel. "Etude et réalisation d'un micro-nano manipulateur avec retour de force : contribution à son intégration dans une plate-forme multicapteurs". Besançon, 2000. https://tel.archives-ouvertes.fr/tel-00509641.
Texto completoGhomi, Mohammad. "Contribution à l'étude des antennes micro-rubans à ondes de fuite". Toulouse, INPT, 1992. http://www.theses.fr/1992INPT015H.
Texto completoZill-e-Huma, Huma. "Hydrodiffusion assistée par micro-ondes : nouvelle technique d'éco-extraction". Thesis, Avignon, 2010. http://www.theses.fr/2010AVIG0239/document.
Texto completoL'hydrodiffusion générée par micro-ondes est une nouvelle technique d'extraction mise au point au sein de l'Université d'Avignon et des Pays de Vaucluse. Ce procédé est une combinaison entre une technique traditionnelle et une technologie innovante. En effet, le chauffage par micro-ondes a permis d'initier et de générer le transfert de matière et de chaleur de l"intérieur des matrices végétales (oignons) vers l'extérieur et de réduire de façon considérable les temps d'extraction des antioxydants sans aucune intervention de solvant. A titre de comparaison, les polyphénols de différentes variétés d'oignons ont été extraits par l'hydrodiffusion générée par micro-ondes et par la technique conventionnelle, l'extraction par solvant. Les rendements obtenus par micro-ondes sont presque identiques à ceux obtenus à l'aide d’un solvant alors que les temps d'extraction sont réduits. La capacité antioxydante des extraits micro-ondes est supérieure à celle obtenue par technique conventionelle. Ce qui présage des potentialités d'application dans le domaine agroalimentaire en particulier pour la valorisation des co-produits. Une étude cinétique de l'extraction, ainsi qu'une observation au microscope optique(cytologie) des matrices traitées soumises aux micro-ondes et au solvant ont mis en évidence la spécificité de l'extraction sans solvant assistée par micro-ondes au niveau des mécanismes de libération et d'extraction des molécules antioxydantes au sein du végétal. L'effet des micro-ondes a pour conséquence une libération plus rapide des principes actifs contenue dans la plante grâce à l'ouverture quasi instantanée des glandes et l'explosion des cellules. L'explication de la différence de composition chimique entre les procédés d'extraction par solvant et par micro-ondes pourrait être basée principalement sur des phénomènes de solubilité, de polarisation diélectrique ainsi qu'un transfert de matière et de chaleur inversé
Clévy, Cédric. "Contribution à la micromanipulation robotisée : un système de changement d'outils automatique pour le micro-assemblage". Phd thesis, Université de Franche-Comté, 2005. http://tel.archives-ouvertes.fr/tel-00134271.
Texto completopetites dimensions sont parmi les thèmes majeurs en micro-robotique. La
"micromanipulation" s'adresse d'une manière générale à la manipulation d'objets
de dimensions globalement comprises entre 1 micromètre et 1 mm et requiert une
résolution de positionnement en rapport avec ces dimensions. Le
micro-assemblage consiste à réaliser une séquence d'opérations élémentaires
conduisant à l'obtention de micro-composants constitués de différentes pièces.
La manipulation de chacune de ces pièces nécessite d'utiliser des effecteurs
dédiés, adaptés à leurs particularités (géométrie, dimensions, propriétés
mécaniques). Différents types d'outils doivent ainsi être utilisés
séquentiellement pour réaliser un micro-assemblage.
Dans ce but, une station de micromanipulation a été réalisée. Elle est composée
d'une micropince montée sur un manipulateur à trois degrés de liberté. Un
système permettant de changer automatiquement l'extrémité de la micropince
(i.e. les outils) a plus particulièrement été étudié et réalisé. Il permet de
fixer alternativement les outils à l'actionneur de la micropince ou à un
magasin en utilisant une colle thermique. Celle-ci est liquéfiée par chauffage
ou solidifiée par refroidissement.
Ce système de changement d'outils apporte une flexibilité notablement accrue à
la station de micromanipulation et permet de réaliser des opérations de
micro-assemblage dans des espaces restreints comme par exemple la chambre d'un
microscope électronique à balayage. Un plan de travail compliant a également
été réalisé. Il permet de limiter les efforts en jeu pendant les opérations de
micromanipulation et d'améliorer ainsi le taux de réussite des opérations
délicates.
Sahbani, Fehim. "Réalisation et caractérisation de déphaseurs micro-ondes accordables à couche active cristal liquide : applications aux antennes à balayage électronique". Littoral, 2011. http://www.theses.fr/2011DUNK0291.
Texto completoFuture telecommunication systems will have to demonstrate potentials in terms of miniaturization, reconfigurability and reliability for low manufacturing costs. It is within this context that our work focuses on the realization of frequency agile microwave devices, reconfigurable, active layer in liquid crystal. The frequency agility of the devices is obtained by varying permittivity of liquid crystal induced by application of an electric field. Many tunable phase shifters have benne made in the context of this work. The first type phase shifters are microstrip with coplanar access. This structure can confine the electromagnetic field in the active part. The phase variation is 0. 63°/cm/GHz for an electric field control with 0. 24 V/([micro]m. To improve the phase variation and limit the size, phase shifters with a serpentine structure were produced and characterized. These structures can increase the effective length of the phase shifter without changing the geometric length and with equivalent performance. In a second step, we studied coplanar phase shifters. The phase variation is 0. 26°/cm/GHz for an electric field control with 0. 25 V/[micro]m. A phase variation of 0. 53°/cm/GHz was obtained on alumina substrate with a liquid crystal with high birefringence. The second part of the project involved the construction and characterization of a phased array antenna. Such a study leading to the realization of a device is new to the laboratory. A bench of measures in the band 26-40 GHz has been developed for measuring the radiation pattern of antennas. The device produced shows that the application of a voltage command changes the radiation pattern. The direction of the main lobe is reoriented to an angle of 35°, the opening angle is 55° and the maximum gain is 10 dB. These results show the feasibility of a phased array antenna phase shifters from active liquid crystal layer
Gu, Sijia. "Contribution to broadband local characterization of materials by near-field microwave microscopy". Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10175/document.
Texto completoNear-field microwave microscopes are emerging instruments for materials characterization. In this work, a home-made near-field microwave microscope is first described and analyzed in terms of resolution performance and frequency band of operation. Then, it is applied to the characterization of a large variety of materials such as metals, semiconductors, dielectrics, liquids and 2D nanomaterials. The system is based on an interferometric technique to improve the measurement sensitivity in the entire frequency range of operation spanning from 2 to 18 GHz. The sensitivity and the different operating modes available (contact, non-contact, liquid environment) allow addressing a large variety of application fields. The instrument allows a sub-wavelength lateral resolution which is more than two orders of magnitude smaller than the operating wavelength, opening the way to a local characterization. The cavity perturbation and transmission line approaches have been used to extract the electromagnetic properties of materials. In particular dielectric properties of saline aqueous solutions and complex impedance of graphene have been investigated in a broad frequency band. It provides a quantitative analysis of material properties in a non-destructive manner to address numerous applications in many scientific fields. Finally, all the results together show that the interferometer-based near-field microwave microscope has the potential to become an important metrology tool for characterizations in micro- and nano-electronics
Benfedda, Mohamed. "Micro-sondes de champ proche optique pour l'opto-électronique". Montpellier 2, 1999. http://www.theses.fr/1999MON20068.
Texto completoTanguy, Quentin. "Design and fabrication of a MEMS scanner for OCT imaging endo-microscopic probe". Thesis, Bourgogne Franche-Comté, 2018. http://indexation.univ-fcomte.fr/nuxeo/site/esupversions/8d6ab7ed-eac5-4e11-997b-f9e9af4e8808.
Texto completoThe work presented in this manuscript consists in the conception of an electro-thermo-mechanical optical micro-scanner. In a first time, a design and a model are proposed and the micro-device was fabricated, characterized and a draft of integration onto a Mirau micro-interferometer was carried out in order to build an endoscopic probe for the detection of early stage gastrointestinal cancers using an imaging technique called Optical Coherence Tomography (OCT). The very contribution of the thesis is the development and the fabrication of micro actuators driven electrothermally to control the angular position a micro mirror plate conceived in this purpose. Different architectures of micro-scanners are proposed to best comply with the specifications determined by both the optical expectations and the medical standards requirements of the final apparatus emph{in vivo}.This work, part of a project called textquote{DEMO4} was financed by the French LabEx Action funding source in cooperation between the departments AS2M and MN2S of the French research institute Femto-ST as well as the university of Florida in the USA to deliver a first demonstrator of endoscopic OCT probe.Several batches of fabrication were realized my means of techniques of ac{CMOS}-based microfabrication in exchange between Femto-ST and the university of Florida before being assembled (for lack of monolithic integration capability) onto a micro-interferometer using automated processes specifically developed in this purpose.Finally, an experimental setup is proposed to characterize in order to evaluate the performances achieved and initiate the first tests of optical imaging using the micro-system
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
Goldfarb, Fabienne. "Microscopie de photodétachement de Si ̄et OH ̄ : spectroscopie micro-eV par imagerie de fonction d'onde pour un test de validité du modèle de l'électron libre". Paris 11, 2003. https://tel.archives-ouvertes.fr/tel-00004059.
Texto completoThe photodetachment microscope was built in the middle of the nineties at Laboratory Aimé Cotton. It enables one to record interference patterns due to electrons detached from negative ions by a laser into a uniform electric field. In a first approximation, the previously linked electron and neutral species don't interact any more after detachment : we have a free electron source. According to the classical equations of movement, a free electron placed in a uniform electric field with a given kinetic energy has two different trajectories for going to a given point. In a quantum point of view, the electronic matter wave is divided into two parts, which follow both possible ways. As the electronic wave emitted by photodetachment is coherent, these two half-waves interfere. The recorded interference patterns are highly sensitive to the electron kinetic energy, which can thus be measured by comparison between the experimental data and the free electron model predictions. These high resolutlon spectroscopy measurements were used for testing the free electron model validity for the Si ̄and OH ̄anions, looking for possible interaction effects between the detached electron and the neutral species. The Si ̄anion enables us to show the validity of the method for an atom heavier than those previously studied. The OH ̄molecular anion was chosen for examining the dipolar potential effect on the interference images. We didn't see any modification of the images, and the obtained results validated this method for the measurements of diatomic anion detachment energies. These researches provided new values for the electron affinities of Si and OH, with an improved accuracy
Gluchko, Sergei. "Manipulation d’énergie thermique avec des ondes de surface électromagnétique aux échelles micro- et anoscopiques". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLC075/document.
Texto completoSurface phonon-polaritons (SPhPs) are evanescent electromagnetic surface waves generated by the phononphoton coupling and that propagate along the interface of a polar medium (such as SiO2 and SiC) and a dielectric one. In this work, we investigate possible applications of SPhPs for enhancing the thermal performance of micro- and nanoscale devices, focusing of thermal energy with micro-structures, decreasing the diffraction angles of infrared radiation on subwavelength apertures, and demonstrating broadband coherent thermal emission. We also perform infrared spectroscopy microscopy measurements of microscale objects and demonstrate long-range thermally excited surface modes in a broad frequency range. The results presented in this thesis can have possible applications in fields related to heat transfer, infrared optics, near-field thermal radiation, infrared microscopy, and polaritonics
Brunet, Nicolas. "Etude de l'influence du liquide de couplage sur la micro-caractérisation de matériaux par signature acoustique". Montpellier 2, 1998. http://www.theses.fr/1998MON20168.
Texto completoBenzaim, Oussama. "Techniques multi-port pour la conception et la réalisation de systèmes micro-ondes dédiés à l'évaluation non destructive de matériaux". Electronic Thesis or Diss., Lille 1, 2009. http://www.theses.fr/2009LIL10031.
Texto completoNon Destructive microwave Testing (NDT) consists in examining a material so that after testing, its future use is not affected. Such characterization is usually achieved through the measurement of reflection and/or transmission properties of the material under test by a vector network analyzer. However, this type of equipment is oversized in terms of measurements abilities and cost for a use outside the laboratory. In order to overcome this limitation, we have developed, with a view to low cost, systems based on the six-port technique. In particular, a dual four-port reflectometer is developed for the measurement of reflection and transmission parameters of passive devices in the frequency range of 55 - 65 GHz. In addition, we have proposed complete solution which integrates hardware and software resources allowing the development of specialized systems in the field of microwave characterization. The added software solutions, based on artificial neural networks contribute to satisfy the needs of a non-destructive, quantitative evaluation. Finally, in order to perform characterization of defects whose dimensions are smaller than the wavelength, a mm-wave microscope formed by the mm-wave system and associated with an evanescent wave probe has been proposed. This ensemble reveals changes in magnitude and phase reflection coefficients of the material under test, allowing non-contact measurements. ___________________________________________________________________________
Medvedeva, Anna. "Étude expérimentale de la turbulence au bord du plasma du tokamak ASDEX Upgrade par réflectométrie à balayage ultra rapide". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0240/document.
Texto completoPlasma confinement is limited by energy and particle transport, in which turbulence plays an important role. In this work the measurements of the turbulence characteristics carried out on the ASDEX Upgrade tokamak are presented during the transition from the Low (L) to the High (H) confinement mode which goes through an Intermediate (I) phase where turbulence and shear flows strongly interact. One of the most widely accepted theories concerning the L-H transition describes how the turbulence in the plasma edge is stabilized by radial electric field gradients: the E×B flow shear stabilizes turbulence and decreases the radial size of turbulent structures. As a consequence, a transport barrier forms in the edge where the plasma density, the temperature, and their gradients increase. The detailed physical mechanism of the formation of the transport barrier as well as the reason for the residual transport across this barrier are not yet well understood. The density dynamics is measured by an ultra-fast swept reflectometer with a time resolution as high as 1 μs. Studies of the electron density profile dynamics, the density turbulence level, radial wavenumber and frequency spectra during L-H transitions have been performed. The reflectometer measurements show that the density large scale fluctuations decrease after an L-H transition, which confirms the theoretical predictions of the turbulence reduction by sheared flows and supports previous experimental evidences. I-phases for various plasma conditions are documented and the density evolution is compared with the turbulence level. Moreover the results on high frequency coherent modes appearing at the plasma edge are presented
Benzaim, Oussama. "Techniques multi-port pour la conception et la réalisation de systèmes micro-ondes dédiés à l'évaluation non destructive de matériaux". Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10031/document.
Texto completoNon Destructive microwave Testing (NDT) consists in examining a material so that after testing, its future use is not affected. Such characterization is usually achieved through the measurement of reflection and/or transmission properties of the material under test by a vector network analyzer. However, this type of equipment is oversized in terms of measurements abilities and cost for a use outside the laboratory. In order to overcome this limitation, we have developed, with a view to low cost, systems based on the six-port technique. In particular, a dual four-port reflectometer is developed for the measurement of reflection and transmission parameters of passive devices in the frequency range of 55 - 65 GHz. In addition, we have proposed complete solution which integrates hardware and software resources allowing the development of specialized systems in the field of microwave characterization. The added software solutions, based on artificial neural networks contribute to satisfy the needs of a non-destructive, quantitative evaluation. Finally, in order to perform characterization of defects whose dimensions are smaller than the wavelength, a mm-wave microscope formed by the mm-wave system and associated with an evanescent wave probe has been proposed. This ensemble reveals changes in magnitude and phase reflection coefficients of the material under test, allowing non-contact measurements. ___________________________________________________________________________
Dominique, Cyril. "Modélisation dynamique des modules actifs à balayage électronique par séries de Volterra et intégration de ces modèles pour une simulation de type système". Paris 6, 2002. http://www.theses.fr/2002PA066106.
Texto completoMétais, Samuel. "Façonnage des ondes : de la superdirectivité à la superrésolution". Thesis, Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCC008.
Texto completoDuring this PhD, we have taken interest in general wave physics. From d’Alembert’s wave equation, one can find three ways of controlling the waves : tuning the source distribution, for one part, altering the boundary conditions, for another part, and finally, modeling the propagation medium itself. Those three tools have been demonstrated during three different projects. Firstly, we have used an electronically reconfigurable binary métasurface to control the wave field inside a micro-wave cavity. Extending this concept to an open cavity, we have demonstrated that we can actually control the farfield emission of this system. This has allowed us to design a compact reconfigurable directive antenna from an open micro-wave cavity. Secondly, we have used the metamaterial approach to overcome the directivity limit of antenna that has been considered by the community since its prediction in the 40s. Using a wire medium, which is known for its sub-wavelength control of the nearfield, we have extended this to the farfield emission of a singular source inside. Using only four passive resonant scatterers, we have been able to make a single source superdirective. Lastly, we have designed and performed an acoustic experiment to create a new non-linear imaging technique. Ever since the contributions of structured illumination and non-linear fluorescent imaging, breaking the diffraction limit has been shown to be possible. We design here a new method, based on the Doppler effect, to get rid of contrast agents. Using rotating sources and receivers, we have shown that this system performs, in homodyne detection, as well as a structured illumination microscope. However, the spectral richness of the signal allows us to further hence the resolving power of our system, and hence, achieve true super-resolution
Omarouayache, Rachid. "Imagerie et injection électromagnétique en champ proche micro-onde et millimétrique". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS032/document.
Texto completoNear-field microwave microscopy is developped in two frequency bands. The first experiment involves very high frequencies at 60 GHz. Near-field electric probes were designed, made and tested. We have shown a sensitivity to topography and to the local dielectric constant with a very sub-wavelength resolution of lambda/250.The second experiment was conducted in the 1 MHz - 1 GHz band. Specific magnetic ferrite probes were designed and optimized with aim of integrated circuit coupling applications. We have explained the coupling by a mutual inductance which allowed to derive an electrical circuit model. Experimental applications on dedicated circuits validate the approach
Trinkler, Nolwenn. "La guérison coquillière : un mécanisme de défense de la palourde japonaise Ruditapes philippinarum face au Vibrio tapetis dans le cadre de la maladie de l'anneau brun". Phd thesis, Université de Bretagne occidentale - Brest, 2009. http://tel.archives-ouvertes.fr/tel-00543317.
Texto completoCastanet, Uli. "Contribution à l’étude des systèmes nanostructurés CeO2, Au et Au/CeO2". Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0600/document.
Texto completoNanomaterials are more and more used in various situations, such as catalysis,color, optics, etc. To optimize their use, it is necessary to better understand reactions andinteractions taking place at these scales. This PhD thesis aims at exploring the links betweensynthesis conditions, particle morphology and their properties. In particular, we chose a tostudy a model-material: cerium (IV) oxide. CeO2 nanoparticles have been obtained bymicrowave-heating assisted solvothermal synthesis. Morphologies obtained and studied havebeen: cubes, octahedrons and rods. We tried to to give an explanation on how these synthesesallowed the formation of such morphologies. Gold has then be deposed on the surface of theseCeO2 nanoparticles, and studied by a combination of Transmission Electron Microscopystudies, and computer modelizations