Dissertations / Theses on the topic 'Couche diffuse'
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Peverini, Luca. "Etude des procédés de croissance de couche et de décapage ionique par mesures de diffusion spéculaire et diffuse de rayons." Phd thesis, Université Joseph Fourier (Grenoble), 2005. http://www.theses.fr/2005GRE10022.
Full textA novel X-ray scattering technique and a dedicated apparatus have been conceived and realized at the optics beamline BM5 at the ESRF. The apparatus permits to study the surface roughness in-situ and in-real time via grazing incidence X-ray scattering. The interaction of X-rays with the surface was analyzed in the framework of the first order scalar perturbation theory expressing the surface's attributes through the power spectral density function. Information on the rms roughness, the correlation length, the roughness conformi and the scaling exponents characterizing the synthesis process could be extracted. The potential of the method was demonstrated for two particular cases : thin film deposition by magnetron sputtering and surface etching by ion beam bombardment. Finally, the obtained experimental results were discussed in the light of the present models of film growth an ion interaction with solids
De, Vroey Laurent. "Modélisation des couches minces électriques dans les bio-microsystèmes." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2008. http://tel.archives-ouvertes.fr/tel-00762196.
Full textGaombalet, Jérôme. "Le Gonflement des argiles et ses effets sur les ouvrages souterrains de stockage." Palaiseau, Ecole polytechnique, 2004. http://www.theses.fr/2004EPXX0009.
Full textVoarino, Philippe. "Lumière diffuse et microsphères multicouches : calculs et réalisations." Phd thesis, Aix-Marseille 3, 2004. http://tel.archives-ouvertes.fr/tel-00083581.
Full textLa deuxième partie de notre travail a consisté en la réalisation des micro-composants. Pour cela nous avons entièrement mis au point une technologie de pulvérisation par faisceau d'ions (IBS), pour fabriquer des couches minces optiques métalliques ou diélectriques. Pour revêtir les microsphères, nous les animons d'un mouvement aléatoire conféré par une membrane vibrante. Les résultats montrent que notre procédé fonctionne très correctement pour une fabrication en série, ouvrant ainsi la porte à des poudres optiques interférentielles. Ensuite le problème de la caractérisation est traité à l'aide d'un diffusomètre laser et d'un spectro-diffusomètre, pour tenter de mesurer une sphère isolée ou des collections de microsphères.
De façon générale, ce travail trouve des applications dans la couleur et cosmétique, la visualisation, la furtivité et les télécom, le biomédical...
Petitdidier, Nils. "Système d'imagerie pour la caractérisation en couches de la peau par réflectance diffuse." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAD048/document.
Full textThis work presents the development of a low-cost, wearable instrument for quantitative monitoring of skin physiological parameters toward non-invasive diagnostics in vivo. The instrument is based on the spatially resolved Diffuse Reflectance Spectroscopy (srDRS) technique, which provides absolute quantification of absorption and scattering endogenous properties of the probed tissue volume with a potential to discriminate between properties of individual skin layers. In the developed instrument, this potential is maximized by the use of a multi-pixel image sensor to perform contact, high resolution imaging of the diffuse reflectance. This study comprises the specification and validation of a novel srDRS system architecture based on the proposed approach, the implementation of this architecture into a low-cost, wearable device and the evaluation of the device performance both on tissue-simulating phantoms and in vivo. Results validate the potential of the instrument for the non-invasive, quantitative monitoring of tissue properties. The described approach is promising for addressing the analysis of layered tissue suchas skin and paves the way for the development of low-cost, wearable devices for continuous, passive monitoring of tissue optical properties
Gilbert, Olivier. "Ellipsométrie sur champ sépculaire et diffus : théorie et expérience." Aix-Marseille 3, 2004. http://www.theses.fr/2004AIX30056.
Full textAn ellipsometer based on an elasto optic modulation of polarization has been developped. Compare to a rotating polarizer setup, the performances, in term of accuracy and speed, have been significantly improved. Specular measurements make it possible to detect the presence of contamination on a component, without preliminary knowledge of its index of refraction. The measurement of polarimetric phase has been extended to the scattered field. In the case of components slightly heterogeneous, it is possible to discriminate the source of scattering (surface or bulk). We highlighted the effects of interferences between surfaces and bulks, and the sensitivity to cross-correlation effects in the multilayers. At last, in the case of very heterogeneous components, which require to take cross-polarization into account, the measurement of the polarimetric phase of the speckle reveals a specific signature of all components
Andrianantoandro, Alain. "Etude par anémométrie laser d'une couche limite turbulente de diffuseur soumise à un champ acoustique intense." Aix-Marseille 2, 1992. http://www.theses.fr/1992AIX22071.
Full textMarsan, Aurélien. "Analyse et contrôle des écoulements en compresseur centrifuge avec diffuseur aspiré." Phd thesis, Ecole Centrale de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00965080.
Full textLatour, Gaël. "Les couches picturales stratifiées : analyse et modélisation de l'aspect visuel." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2007. http://tel.archives-ouvertes.fr/tel-00239196.
Full textTrujillo, Tovar Maria Sonia. "Synthèse et caractérisation de matériaux ferroélectriques relaxeurs à base de Na1/2Bi1/2TiO3 (NBT)." Grenoble INPG, 2006. http://www.theses.fr/2006INPG0066.
Full textThis work lies within the broader scope of research related to so-called relaxor ferroelectrics with currently attract considerable attention from both a fundemental and an application point of view. The first part of this work is related to the synthesis of thin films. Our results highlight the difficulty in synthesizing thin films of Na1/2Bi1/2TiO3 by chemical processes. This difficulty is directly related to a complex chemistry during the deposition of bysmuth and sodium. The second part of our work concerns the fundamental understanding of pure Na1/2Bi1/2TiO3 and NBT doped with Baryum (NBT-BT). Two techniques of characterization have been used in our work: Raman spectroscopy and X-tays scattering, in particular diffuse scattering. We have carried out the first high-pressure study of NBT-BT by Raman scattering. The spectral analysis shows that NBT-BT evolves under pressure in two regimes: a first, where the pressure forces NBT-BT towards the structure of NBT (pc=1,8 GPa) and a second where NBT-BT evolves like NBT with a new phase transition around 12 GPa. The study by X-ray scattering enable us to follow the structural evolution with the chemical composition. With regard to the local structure, we present evidence that the diffuse X-ray scattering evolves significantly with Barium substitution. It is particularly interesting to note that diffuse scattering does not only change in intensity but that its distribution in the reciprocal space does also change notably
Cherdieu, Patrick. "Contrôle du décollement dans un diffuseur aubé de turbomachine centrifuge." Thesis, Ecole centrale de Lille, 2013. http://www.theses.fr/2013ECLI0020/document.
Full textThe performance improvement of turbomachinery operating at off-design conditions can be achieved by the understanding of unsteady phenomena which are occuring in its components. The present study is focussing on the interaction between a centrifugal impeller fan and its vaned diffuser. It aims at analysing precisely these unsteady phenomena (and especially the fluctuating separated region identified on the vanes wall) and their consequences on the diffuser performance by three holes probe and unsteady pressure measurements. In a second step, devices for a passive control of the separation are introduced. Several configurations are tested and their results are compared
Robin, Olivier. "Reproduction de champs de pression acoustique aléatoires sur des surfaces planes." Thèse, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6140.
Full textPriem, Thierry. "Étude de l'ordre à courte distance dans les carbures et nitrures non stoechiométriques de métaux de transition par diffusion diffuse de neutrons." Paris 11, 1988. http://www.theses.fr/1988PA112408.
Full textPriem, Thierry. "Etude de l'ordre à courte distance dans les carbures et nitrures non-stoechiométriques de métaux de transition par diffusion diffuse de neutrons." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37617731g.
Full textLe, Bourlot Jacques. "Calcul de probabilites de transition d'intercombinaison entre les etats x **(1)sigma ::(g)**(+) et a **(3)pi ::(v) de c::(2) carbone moleculaire : application a l'equilibre de c::(2) dans les nuages interstellaires diffus." Paris 7, 1987. http://www.theses.fr/1987PA077128.
Full textDeumié-Raviol, Carole. "Ellipsométrie sur champ diffus et analyse multi-échelle de la microstructure des multicouches optiques : diffusion lumineuse, microscopie à force atomique, microscopie à effet tunnel optique." Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30087.
Full textButtard, Denis. "Étude structurale du silicium poreux de type p par diffraction haute résolution des rayons X." Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10141.
Full textAlaili, Kamal. "Transport de chaleur dans les nano-couches minces excitées par une source laser d'intensité modulée." Thesis, Poitiers, 2019. http://www.theses.fr/2019POIT2314.
Full textThis work, separated into two main parts, deals with the study of heat transport in nano-layers excited by a laser beam with modulated intensity. In the first part, we exploit the analytical solution of the phonon Boltzmann transport equation to describe the variations of temperature and heat flux in thin dielectric films excited by a laser beam of modulated intensity. This last solution allows us to model the behavior of the interface thermal resistance (ITR) between two dielectric layers according to the nature of the phonon transport regime and the modulation frequency. In the steady state regime, we show that this interface resistance has a non-intrinsic and asymmetric character with regard to the two layers properties. In addition, it becomes very important when the phonon transport regime is ballistic. Our results are in good agreement with the DMM in the ballistic regime, while they differ by about 16% in the diffusive regime. However, in the dynamical regime, we mainly show that in the diffusive regime, the ITR reaches a maximum at a characteristic modulation frequency. The expression of this characteristic frequency can thus be used to determine the dominant phonons mean free path and relaxation time through the comparison of the theoretical model and the experimental data. In the second part, we propose three different ways to extract simultaneously the thermal diffusivity and conductivity of a finite layer based on the Fourier heat equation. The idea is to use the exact expression of the temperature profile at the front surface of the thin layer when the latter is excited by a periodic heat flux, while the rear surface can be maintained at one of three different types of boundary conditions: modulated periodic heat flux, modulated temperature, or constant temperature. We determine the expressions of the modulation frequencies at which the front surface temperature reaches its first maximum and first minimum. The combination of these characteristic frequencies with the ratio between the first maximum and the first minimum of the temperature, thus leads to the determination of the diffusivity and thermal conductivity
Descamps, Isabelle. "Érosion éolienne d'un lit de particules à large spectre granulométrique." Valenciennes, 2004. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/44494702-5d08-4012-8430-5783e7c50c30.
Full textThis research deals with diffuse dust emissions on steelwork sites. It aims to estimate more accurately dust emissions due to wind erosion of exposed aggregate storage piles. Previous studies have shown the importance of the surface material's characteristics on aerodynamic entrainment. Only few recent experimental investigations focused on multiple grain-sized bed. They show that coarser particles at the bed's surface induces a temporal decrease in the emitted mass flux. In the present study, a stochastic wind erosion model, which takes into account a wide size distribution of materials, has been developed. It is based on the interaction between particles take-off and turbulent coherent structures. It allows to predict a temporal decrease in emitted mass flux from a multiple grain-size bed exposed to a turbulent flow. The rate of this decrease depends on the flow velocity and the characteristics of the particles. Numerical results were compared to experimental datas for adjustments
He, Huan. "Nitruration ionique assistée plasma de l'inconel 690 : étude comparative des couches diffusées et des films minces obtenus par pulvérisation magnetron réactive." Vandoeuvre-les-Nancy, INPL, 2004. http://www.theses.fr/2004INPL019N.
Full textL'inconel 690 est un alliage à base Nickel avec un potentiel d'application industriel important. En dépit de son excellente résistance à la corrosion et de ses bonnes performances à haute température, ce matériau n'offre pas une bonne résistance à l'usure. Ce travail présente une investigation sur la nitruration assistée par plasma (NAP) à basse température de ce matériau. Une revue des progrès récents en NAP est présentée dans le premier chapitre. Le dispositif expérimental et les techniques de caractérisation de surface utilisées sont présentés dans le deuxième chapitre. La NAP de l'Inconel 690 est présentée dans les chapitres suivants (3-5). La diffraction des rayons X, la microscopie électronique à balayage et à transmission, ainsi que la spectrométrie de masse des neutres pulvérisés ont été utilisées pour caractériser les échantillons nitrurés. Il est montré que l'épaisseur des couches nitrurées dépend de l'orientation des grains. La diffraction des électrons rétro diffusés (EBSD) a été utilisée pour établir une relation linéaire entre l'épaisseur locale de la couche nitrurée est l'angle minimum entre les directions cristallines <100> et la direction de diffusion. Le chapitre 4 présente un modèle basé sur une diffusion anisotrope induite par les contraintes résiduelles. La résistance à la corrosion des couches nitrurées est présentée dans le chapitre 5. Le chapitre 6 présente une comparaison entre les solutions solides c. F. C. Sursaturées métastables γN obtenues par NAP et par pulvérisation réactive magnétron de l'Inconel 690 dans des mélanges Ar-N2
Acremont, Quentin d'. "Étude des propriétés thermiques de librairies d’alliages ternaires en couches minces et mise en évidence du transport non-diffusif par spectroscopie thermique pompe-sonde femtoseconde." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0665/document.
Full textIn this work, we studied ultrafast thermal transport at nanoscale in thin films by femtosecond pump-probe thermal spectroscopy. We first developed a high-throughput heterodyne thermoreflectance setup that allows the extraction of thermal properties of a large number of sample in a minimum time, aiming at creating a database of these properties for a large numberof thin film ternary alloys with thermoelectric potential. In the second part of this work, wefocused on the study of thermal transport in three materials : Ge, GaAs and InGaAs. A high resolution phonon spectroscopy setup, along with a spectral reconstruction method allowed usto measure the response of these materials up to several tens of GHz in Fourier domain, which highlighted the presence of non-diffusive thermal transport in InGaAs. Non-diffusive theory,based on Lévy dynamics, allowed us to model this superdiffusion phenomenon and to extract coherent, frequency-independant thermal properties of these materials. Also, high frequency(>GHz) measurements of these spectral responses have shown interesting effects related to the ultrafast thermalisation in transducer-like very thin films. Finally, high-frequency thermal spectroscopy is inherently limited by the intrinsic timing jitter of laser cavities. Thus, the last partof this work was dedicated to developing a timing jitter measurement and active laser synchronisation system in order to increase the signal-to-noise ratio and access higher frequencies in pump-probe thermal spectroscopy experiments
Guibourdenche, Julien. "Préoccupations et agencements dans les contextes d'activité domestique : Contribution à la conception de situations informatiques diffuses, appropriables et énergétiquement efficaces." Phd thesis, Université Lumière - Lyon II, 2013. http://tel.archives-ouvertes.fr/tel-01068697.
Full textZhang, Peipei. "Diffuse response surface model based on advancing latin hypercube patterns for reliability-based design optimization of ultrahigh strength steel NC milling parameters." Compiègne, 2011. http://www.theses.fr/2011COMP1949.
Full textSince variances in the input parameters of engineering systems cause subsequent variations in the product performance, and deterministic optimum designs that are obtained without taking uncertainties into consideration could lead to unreliable designs. Reliability-Based Design Optimization (RBDO) is getting a lot of attention recently. However, RBDO is computationally expensive. Therefore, the Response Surface Methodology (RSM) is often used to improve the computational efficiency in the solution of problems in RBDO. In this work, we focus on a Response Surface Methodology (RSM) adapted to the Reliability-Based Design Optimization (RBDO). The Diffuse Approximation (DA), a variant of the well-known Moving Least Squares (MLS) approximation based on a progressive sampling pattern is used within a variant of the First Order Reliability Method (FORM). The proposed method simultaneously uses points in the standard normal space (U-space) as well as the physical space (X-space). The two grids form a “virtual design of experiments” defined by two sets of points in the two design spaces, that are evaluated only when needed in order to minimize the number of ‘exact’ thus computationally expensive function evaluations. In each new iteration, the pattern of points is updated with points appropriately selected from the “virtual design of experiments”, in order to perform the approximation. As an original contribution, we introduce the concept of « advancing Latin Hypercube Sampling (LHS) » which extends the idea of Latin Hypercube Sampling (LHS) to maximally reuse previously computed points while adding a minimal number of new neighboring points at each step, necessary for the approximation in the vicinity of the current design. We propose panning, expanding and shrinking Latin hypercube patterns of sampling points and we analyze the influence of this specific kind of patterns on the quality of the approximation. Next we calculate the minimal number of data points required in order to get a well-conditioned approximation system. In the application part of this work, we investigate the optimization of the process parameters for Numerical Control (NC) milling of ultrahigh strength steel. The success of the machining operation depends on the selection of machining parameters such as the feed rate, cutting speed, and the axial and radial depths of cut. A variant of the First Order Reliability Method (FORM) is chosen to calculate the reliability index. The optimization constraints are expressed as functions of the computed reliability indices
Marty, Alain. "Étude expérimentale et modélisation thermodynamique de l'ordre à petite et à longue distance dans des alliages ternaires base nickel." Paris 6, 1990. http://www.theses.fr/1990PA066230.
Full textWeis, Frédéric. "Exploitation d'approches système dans les réseaux sans fil." Habilitation à diriger des recherches, Université Rennes 1, 2012. http://tel.archives-ouvertes.fr/tel-00790484.
Full textBessenay, Gilles. "Mesures d'intensité diffuse sur monocristal en rayonnement synchrotron : mise en place de l'appareillage et tests, aspects structuraux et cinétiques de l'ordre local dans les alliages Au-Cu." Paris 6, 1986. http://www.theses.fr/1986PA066019.
Full textZebiri, Boubakr. "Étude numérique des interactions onde de choc / couche limite dans les tuyères propulsives Shock-induced flow separation in an overexpanded supersonic planar nozzle A parallel high-order compressible flows solver with domain decomposition method in the generalized curvilinear coordinates system Analysis of shock-wave unsteadiness in conical supersonic nozzles." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMIR06.
Full textThe need for a better understanding of the driving mechanism for the observed low-frequency unsteadiness in an over-expanded nozzle flows was discussed. The unsteady character of the shock wave/boundary layer remains an important practical challenge for the nozzle flow problems. Additionally, for a given incoming turbulent boundary layer, this kind of flow usually exhibits higher low-frequency shock motions which are less coupled from the timescales of the incoming turbulence. This may be good from an experimenter’s point of view, because of the difficulties in measuring higher frequencies, but it is more challenging from a computational point of view due to the need to obtain long time series to resolve low-frequency movements. In excellent agreement with the experimental findings, a very-long LES simulation run was carried out to demonstrate the existence of energetic broadband low-frequency motions near the separation point. Particular efforts were done in order to avoid any upstream low-frequency forcing, and it was explicitly demonstrated that the observed low-frequency shock oscillations were not connected with the inflow turbulence generation, ruling out the possibility of a numerical artefact. Different methods of spectral analysis and dynamic mode decomposition have been used to show that the timescales involved in such a mechanism are about two orders of magnitude larger than the time scales involved in the turbulence of the boundary layer, which is consistent with the observed low-frequency motions. Furthermore, those timescales were shown to be strongly modulated by the amount of reversed flow inside the separation bubble. This scenario can, in principle, explain both the low-frequency unsteadiness and its broadband nature
Chassagne, Francis. "Etude de l'ordre à courte distance dans la solution solide gamma Ni-Al." Paris 6, 1986. http://www.theses.fr/1986PA066098.
Full textRobach, Odile. "Étude in situ de la croissance de Ag sur MgO(001) et de Ni/Ag(001), et étude de la nitruration du GaAs par diffusion de rayons X en incidence rasante." Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10226.
Full textKulyk, Olena. "Light-tissue interactions for developing portable and wearable optoelectronic devices for sensing of tissue condition, diagnostics and treatment in photodynamic therapy (PDT)." Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/13199.
Full textAltmeyer, Guillaume. "Modélisation théorique et numérique des critères d'instabilité plastique : application à la prédiction des phénomènes de striction et de localisation lors d'opérations d'emboutissage." Phd thesis, Paris, ENSAM, 2011. http://pastel.archives-ouvertes.fr/pastel-00695660.
Full textRigaut, Olivier. "Nouveaux concepts pour les matrices de bolomètres destinées à l’exploration de l’Univers dans le domaine millimétrique." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112076/document.
Full textSince its discovery in 1964, the study of the Cosmic Microwave Background (CMB) in the field as of millimetre-length wavelengths became a major stake of experimental research in the field of cosmology. In particular, its anisotropies in temperature, measured for the first time by satellite COBE then more finely by the experiment WMAP and the PLANCK satellite. The predicted existence of anisotropies of polarization of the Cosmic Microwave Background is currently been part of the privileged field of experimentation of the study of the CMB. Indeed, the proof of exists modes B of polarization, single signature of the paramount gravitational waves, currently is the object of an intensive experimental research by the means in particular of the instrument BICEP2 which would have detected its signature in 2014 in values of the tensor report on scalar R = 0.2. Project QUBIC makes party of these experiments intended to reveal the modes B of polarization thanks to its instrument based on the technique of the interferometers and the development of bolometers array, asking for a thorough field of investigation including, amongst other things, the solid state physics, the physics of the low temperatures and cosmology. The thesis presented here is within this framework, with for objective making of a bolometers array whose performance and optimization should make it possible to acquire the necessary sensitivity to the observation of the B-mode polarization. The various experimental techniques acquired with the CSNSM of Orsay indeed make it possible to consider the optimization of the key elements of the bolometers array while being pressed in particular on amorphous alloy of NbxSi1-x for making of an optimized thermal sensor, and on an innovative material, titanium-vanadium alloy, for the clarification of an effective superconducting absorber of radiation, whose low specific heat must make it possible to reach a response time of the detector about ten millisecond, value of the response time necessary to an effective reading of the signal of the Cosmic Microwave Background. The manuscript of thesis here present has as an ambition to develop the physical principles necessary to the field of investigation of work to be achieved. Thus, this study proposes to work out the various elements of a bolometer, joining together a thermal sensor optimized as well as an absorber of radiation of low specific heat, making it possible to consider the clarification of a bolometers array optimized within the framework of the project QUBIC whose observation campaign is envisaged during 2015 with the dome C of the south pole
Guen, Eloise. "Microscopie thermique à sonde locale : Etalonnages, protocoles de mesure et applications quantitatives sur des matériaux nanostructurés." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI003.
Full textScanning thermal microscopy (SThM) is a technique that allows characterizing the thermal properties of nanomaterials and helps understanding heat transfer at submicron scales. To interpret the measurements, parameters influencing heat transfer between the probe and the sample are studied. Firstly, three resistive SThM probes, differing in particular by their micro and nanometric radii of curvature, are analyzed and a systematic methodology for the measurements is proposed. It is put forward that the sensitive zone to thermal conductivity of bulk planar materials is limited to few W.m-1.K-1 for the three probes. For the more conductive materials, SThM measurements are dominated by interfacial thermal resistance. Heat transfer at the solid-solid nanocontact between the probe and the sample can be both ballistic and diffusive. It is further demonstrated that surface roughness strongly impacts SThM measurements, decreasing heat transfer at the contact by more than 50 % in some cases. This work is used for characterizations of nanomaterials. The determination of the thermal conductivity of SiO2 thin film on silicon substrate indicates that thicknesses of a few nanometers up to 1 µm are detected by certain probes. Phase transition temperature measurement by SThM is also studied, using a calibration with bulk polymers. The application of this calibration for the characterization of polymer thin films demonstrates the influence of the substrate and the thin film thickness on the temperature determined by SThM. These results demonstrate that scanning thermal microscopy allows obtaining quantitative measurements
Pic, Axel. "Numerical and experimental investigations of self-heating phenomena in 3D Hybrid Bonding imaging technologies." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI054.
Full textIn this PhD thesis, self-heating phenomena are studied for guiding the design of next-generation 3D Integrated Circuits (ICs). By means of experimental and numerical investigations, associated heat dissipation in 3D Hybrid Bonding imagers is analyzed and the impact of the resulting temperature rise is evaluated. First, in order to develop accurate models, the thermal properties of materials used in ICs are to be determined. Different dielectric thin films involving oxides, nitrides, and low-k compounds are investigated. To do so, Scanning Thermal Microscopy (SThM) and the 3ω electrothermal method, sensitive to low and large effective thermal conductivity, are implemented. In a second step, finiteelement models of 3D ICs are developed. A numerical method involving homogenization and a multiscale approach is proposed to overcome the large aspect ratios inherent in microelectronics. The numerical procedure is validated by comparing calculations and experimental measurements performed with SThM, resistive thermometry and infrared microscopy on a simplified Hybrid Bonding test chip. It is shown that heat dissipation is mainly limited by the heat sink conductance and the losses through air. Finally, numerical and experimental studies are performed on fully-functional 3D Hybrid Bonding imagers. The temperature field is measured with SThM and compared with finite-element computations at the die surface. The numerical results show that the temperature of the pixel surface is equal to that of the imager Front-End-Of-Line. The influence of the temperature rise on the optical performance of the imager is deduced from the analysis. The study also allows assessing the various numerical and experimental methods for characterizing heat dissipation in microelectronics
Gourde, Karine. "Le droit à un environnement de qualité au Québec : une réponse aux problèmes de pollution diffuse?" Thèse, 2010. http://hdl.handle.net/1866/4794.
Full textThe quality of the environment has become a growing concern in the recent years for Quebec citizens. Phenomena such as climate change, persistent organic pollutants and the depletion of the ozone layer are caused by several sources, the effects of which cannot be distinguished one from the other and/or linked to a specific event. Furthermore, these phenomena have yet to create damage to Quebec residents in order to create the necessary standing for the introduction of legal proceedings. Also, the scientific uncertainty related to the source of potential damage and to the proof of said damage makes it impossible to legally attack the emitters of the pollutant contributing to this type of environmental phenomena under 1457 C.C.Q. or 976 C.C.Q. We have identified the 3 potential sources of a right to a clean environment which could entitle Quebec citizens to go before the courts in environmental matters, even in the absence of specific damages to their person or property. We have analysed the Canadian Charter of Rights and Freedoms, the Charter of Human Rights and Freedoms and the Environmental Quality Act and looked at the potential right to a clean environment possibly contained therein and the legal actions that could be taken to ensure their respect. Considering the weakness of what our legal system had to propose, we have developed solutions that could be put forward in order to allow the war against climate change and other environmental phenomena of the same nature to become legally actionable.
Gilbert, Olivier. "Ellipsométrie sur champ spéculaire et diffus : théorie et expérience." Phd thesis, 2004. http://tel.archives-ouvertes.fr/tel-00083577.
Full textLes mesures sur champ spéculaire ont tout dabord largement validé le banc et nous avons mis en oeuvre une méthode pour détecter la présence de contamination sur un composant, sans avoir besoin de la connaissance préalable son indice de réfraction.
Dans une deuxième étape, nous avons étendu les mesures à la détermination angulaire du déphasage polarimétrique sur champ diffus. Dans le cas de composants faiblement perturbés, pour lesquels une théorie électromagnétique au premier ordre est utilisée, cette mesure permet de discriminer sans ambiguïté lorigine, surfacique ou volumique, de la diffusion. Nous avons également mis en évidence les effets dinterférences entre ondes diffusées par les surfaces et volumes, grâce à la présence doscillations autour de la valeur moyenne du déphasage, et la sensibilité aux effets de décorrélation verticale dans les multicouches.
Létude des composants très hétérogènes est également abordée dans le détail, en tenant compte des effets de dépolarisation. Nous montrons comment les techniques
précédentes permettent encore de discriminer les effets de surface et de volume. En particulier le déphasage polarimétrique mesuré dans le speckle résolu du champ diffus, constitue une véritable signature des composants. A laide dune approche phénoménologique, on montre que lamplitude des oscillations du déphasage permet dextraire le taux de dépolarisation angulaire. De façon plus générale, la méthode dellipsométrie sur champ diffus permet une scrutation approfondie, tout en ouvrant la porte aux problèmes inverses et de reconstruction en champ lointain.
Liu, Shichao active 21st century. "The effects of indoor jets on air distribution and human exposure to particles." Thesis, 2014. http://hdl.handle.net/2152/28349.
Full texttext
Tien, Wang Min, and 王敏田. "The Effect of Contaminant Control for the Patients Breath and Cough under Different Diffuser Design and Ventilation Rate." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/89250870333544446883.
Full text國立勤益科技大學
冷凍空調系
97
In hospital wards, the air conditioning and ventilation system provides an indoor comfortable environment, also must supply enough fresh air to eliminate contaminants, particularly the viruses diffusion in the air of the patient’s breath and cough. It’s very important how to design an optimal HVAC systems, it can remove contaminants effectively and maintain a suitable thermal comfort under lower energy consumption. Two kinds of common vent arrangements, and constant air volume and variable air volume of the ventilation rate adopted in this research to analyzes the effect of contaminant concentration and thermal comfort when cough period and cough to enlarge air change rate. Both the numerical simulation and full-scale experimental validation adopted in this study. Coding the subprogram of Fluent software by myself to simulate the model of variable inlet air and breathe and cough. The results of this study show that show that increasing air change rate can reduce contaminant concentration, but its effect is less evident by improving air flow pattern, and we found that the variable air volume technique adopted has better contaminant removal efficiency than constant air volume. It is found that adopting variable air volume can raise inlet air temperature to reduce the HVAC system energy consumption under appropriate thermal comfort level.