Thèses sur le sujet « Laser - fil »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 50 meilleures thèses pour votre recherche sur le sujet « Laser - fil ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les thèses sur diverses disciplines et organisez correctement votre bibliographie.
Ushakov, Ilia. « Établissement des structures et propriétés mécaniques de l’alliage d’Inconel 625 dans les procédés d’élaboration additive à grande vitesse : arc fil, laser fil, laser poudre et hybride ». Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0147.
Texte intégralThis work focuses on the establishment of microstructures and the characterization of the mechanical properties of Inconel 625 alloy produced as part of the PAM-PROD project aimed at producing large parts using high deposition rate additive manufacturing. Three deposition techniques are being studied: Arc/Wire, Laser/Wire and Laser/Powder, as well as a combination of Laser/Wire and Laser/Powder to produce a hybrid wall. Macrostructures and microstructures are characterized for each process. The Arc/Wire and Laser/Powder processes used lead to a mixed columnar - equiaxed macrostructure. The Laser/Wire process leads to predominantly columnar structures. Mechanisms for the formation of columnar/equiaxed structures and transitions are proposed. These mechanisms are then taken up and completed to interpret the formation of the transition zone in the case of a hybrid Laser Wire/Powder wall. The response to solution heat treatment and ageing is then presented by detailing and comparing the kinetics and mechanisms specific to each process. The tensile mechanical properties along 3 directions are then characterized and related to the structures. For all the processes, a high degree of reproducibility is obtained and none of the processes has a brittle character. The best properties were obtained with the Laser/Powder process, and the hybrid junction test showed that the transition zone was not a weak point in the structure
WALLEE, OLIVIER. « Contribution a l'etude du soudage d'alliages d'aluminium par faisceau laser avec fil d'apport ». Université Louis Pasteur (Strasbourg) (1971-2008), 2000. http://www.theses.fr/2000STR13087.
Texte intégralLeclère, Franck. « Microanastomoses vasculaires assistées par laser diode 1950 nm en chirurgie plastique réparatrice : étude expérimentale et clinique ». Thesis, Lille 2, 2011. http://www.theses.fr/2011LIL2S047.
Texte intégralIn the field of plastic surgery, the most important factor for successful free flap transfer and replantations is a well executed vascular microanastomosis. The aim of these studies is to complement the scientific basis of the 1950 nm diode laser assisted microanastomosis (LAMA) by standardising the technique and studying the postoperative blood flow in animal series. This work introduces the first clinical series. In the first animal series (S1), 30 end-to-end microanastomoses of the carotidis and 30 end-to-end microanastomoses of the external jugular were performed with a 1950 nm diode LAMA technique in Wistar rats. The following laser parameters were used: spot size=400µm, spot duration=1s, Power varying between 100 to 150 mW for arterial microanastomoses and between 90 to 140 mW for venous microanastomoses. They were compared at D0 and at 1, 4 and 12 weeks with 30 conventional arterial microanastomoses and 30 conventional venous microanastomoses.Two other animal series (S2 and S3) were performed using the standardised parameters of the initial studies. In the S2 series, LAMA was performed on a group of 10 carotidis on Wistar rats. Two 10/0 stay sutures and a standard laser tissue welding technique (P=120mW, spot size=400 μm, t=1s, 5 spots for each wall, fluence=95 J/cm²) were used (LAMA group). They were compared with a group of 10 conventional arterial anastomosis (CSMA group). A MRI-positioning sequence (Magnetic Resonance Imaging), an anatomical sequence, an angiographic sequence and a flow sequence were performed 1 day after operation and then after 1, 4 and 8 weeks. Similarly, the series S3 included 20 microanastomoses of the external jugular performed with LAMA (n=10, P=110mW, spot size=400 μm, spot duration= 1s, 4 spots for each wall, fluence 90 J/cm²) or the conventional technique (n=10). For the two groups, contralateral non-operated external jugular were used as control.In total, 40 clinical procedures, including 38 free flaps and 2 finger replantations have been performed with the LAMA technique. End-to-end arterial microanastomoses were performed in 36 cases and end-to-side in 4 cases. All venous microanastomoses were performed end-to-end. LAMA was performed with a 1950 nm diode laser after placement of 2-5 stitches. The following laser parameters were used: spot size=400 μm, spot duration=0.7-2s, 4-8 spots for each wall, power=125 mW, fluence=70-200 J/cm². The animal series S1 demonstrates excellent bloodless patency at fluences ranging from 90 to 100 J/cm² (Power between 110-130mW) for arterial LAMA, and between 80 and 95 J/cm² (Power between 100-120mW) for venous LAMA. The flow-MRI further demonstrates that 1950 nm diode laser-assisted microanastomoses performed with our standardised parameters is a consistent, reliable and reproducible technique. The success rate of the clinical series appears promising. Technical innovation will most likely lead to greater ease of use of the laser handpiece in the operating room
Maquet, Jean. « Contribution à l'étude de la surstabilité d'une surface libre chauffée par un laser ou un fil chaud ». Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37607681j.
Texte intégralRzaigui, Habeb. « Systèmes hybrides opto/sans fil pour les réseaux multi-gigabits aux fréquences millimétriques ». Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT014/document.
Texte intégralThis thesis focuses on the radio-over-fiber (RoF) communication systems at millimeter frequencies in the frequency range 57-66 GHz and optical generation of a signal at millimeter-wave frequency band. The technique used is based on mode-locked laser diodes. The diodes employed in this work are in quantum dots (or quantum dashes) technology. In this thesis, several studies were conducted: the first relates the ability of integration these types of lasers in the RoF communication systems under direct or external modulation. The second study was devoted to propagation effects. An original technique was implemented to reduce the sensitivity to chromatic dispersion in an optical fiber. A study of the reduction of phase noise mode-locked lasers based on the observation of the reaction effect and against the external optical injection was presented
Cazic, Ivan. « Coaxial laser wire additive manufacturing of Inconel 718 ». Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0113.
Texte intégralThe use of Inconel 718 alloy in additive manufacturing has been the subject of numerous studies in recent years. It has appeared early that the control of the morphology and size of the grains forming during solidification is a formidable challenge. Our work aims to address this challenge in the case of coaxial laser wire technology by providing a better understanding of the formation of microstructures, including the conditions for the appearance of fine equiaxed grains observed at the bottom of the melt pools.First, the stability of the process as well as the thermal aspects have been investigated, in connection with solidification. Thanks to fast imaging and thermal imaging, we have been able to estimate the solidification conditions at the bottom of the bath.In a second step, we have analyzed by EBSD the equiaxed zones and we have observed that they are very often clustered with twin relations compliant with some icosahedral symmetry. It is proposed that this particular organization is the signature of an "Icosahedral Short Range Order mediated nucleation" (ISRO) mechanism, which would be favored by the high cooling rates imposed by the process on the one hand, and by local enrichments of the liquid at the bottom of the melt pool during the melting of the previous layer on the other hand.We have therefore characterized the equiaxed zones by SEM and TEM. We have identified TiC carbides in the grain clusters and we have highlighted a strong local enrichment in Nb around the carbides by EDS. We have been able to identify Nb2Ni at the surface of a TiC carbide which requires a high local Nb composition to appear.From these observations we propose a possible scenario for the appearance of fine equiaxed grains in Inconel 718 deposited by the coaxial laser wire technology. TiC would play an important role by capturing minority elements during remelting, and by promoting the local appearance of icosahedral clusters in the liquid that would favor the nucleation of grains whose relative orientations would reflect this icosahedral order
Maquet, Jean. « Contribution à l'étude des mécanismes de surstabilité d'une surface libre chauffée par un laser ou un fil chaud ». Rouen, 1987. http://www.theses.fr/1987ROUES047.
Texte intégralMerigaud, Eric. « Structure de la couche limite turbulente en présence d'aspiration pariétale localisée ». Aix-Marseille 2, 1995. http://www.theses.fr/1995AIX22015.
Texte intégralLassoued, Abdessalem. « Caractérisation de catalyseurs solides par fluorescence induite par laser ». Paris 6, 2001. http://www.theses.fr/2001PA066447.
Texte intégralMouqallid, Mhamed. « Etude de l'interaction de deux jets opposés turbulents ». Rouen, 1991. http://www.theses.fr/1991ROUES007.
Texte intégralLe, Masson Stéphane. « Contrôle de l'instabilité de Benard-Von Karman en aval d'un obstacle chauffé à faible nombre de Reynolds ». Rouen, 1991. http://www.theses.fr/1991ROUES048.
Texte intégralBahmed, Youcef. « Contribution à l'étude de l'organisation d'un jet légèrement pulsé ». Nancy 1, 1997. http://www.theses.fr/1997NAN10036.
Texte intégralThe present study is concerned with the experimental analysis of an axisymmetric water jet (Re ≈10 [to the power] 4), free or slightly excited. The velocity measurements are realised with laser anemometer and/or hot film anemometer. In a first approaches, the study of the fields of average and fluctuation velocities allows the observation of a behaviour already met in literature. Our contribution is concerned with the supply of additional information regarding the formation and development of periodic structure by means of an exhaustive spectral and space-time analysis. Through spectral analysis of the fluctuations of longitudinal and radial velocities, it cornes forward sorne preferential radial distances which are distinct for each component. However, it seems that just at the outlet of the nozzle there is generation of two periodic structures, with characteristics related to the boundary layer thickness for the first, and to the jet diameter for the second. We note that pairing phenomena regards only the lastly designed structure. A slight pulsation of the jet, does not alter significantly the global behaviour of its development. However, in this case we observe only the generation of structures related to the pulsation frequency and to their successive pairing. Since this last phenomenon has the same characteristics as the one recorded for a free jet, the space-time analysis allows the tracking of the development of the structures and the proposition of a mechanism describing their origin development
Gosse, Kevin. « Etude expérimentale de la dispersion d'un scalaire passif dans le proche sillage d'un corps d'Ahmed ». Phd thesis, Université de Rouen, 2005. http://tel.archives-ouvertes.fr/tel-00012128.
Texte intégralLes caractéristiques des champs de vitesse mesurées pour les trois angles d'inclinaison a ont montré que le champ dynamique dans le sillage proche dépend très fortement de cet angle lorsque le nombre de Reynolds augmente. Ces mesures ont mis en évidence pour a=25° l'existence d'une transition 2D-3D à un nombre de Reynolds ReLc=2,7.104. L'étude des champs thermiques a mis en évidence une complexité importante liée à la fois au caractère complexe du champ dynamique et à l'injection décentrée. Nous avons décrit les différents scénarios de transport et de mélange du scalaire en fonction de l'angle a de la lunette arrière. Le problème du mélange a été abordé en étudiant successivement les variations de l'écart de la température moyenne maximale, de l'intensité maximale des fluctuations de température et du taux de dissipation de ces fluctuations. Les résultats obtenus dans cette étude ont permis de déterminer le temps de mélange et d'estimer les ordres de grandeur des concentrations de polluants émises reçues par des récepteurs particuliers (piéton au bord d'une route lors du passage d'un véhicule automobile ou automobiliste dans le sillage d'une voiture).
Gosse, Kévin. « Etude expérimentale de la dispersion d'un scalaire passif dans le proche sillage d'un corps d'Ahmed ». Rouen, 2005. http://www.theses.fr/2005ROUES044.
Texte intégralThis experimental work concerns the diffusion of heat downstream of a point source located at the Ahmed body base for slant angles " of 5°, 25° or 40°. This study has been carried out in air and in water at different Reynolds numbers. Laser Doppler velocimetry (LDV), hot wire anemometry and cold wire thermometry have been used to measure velocity and temperature in the near wake ( ). Characteristics of the velocity fields have been found to be strongly dependent on " when the Reynolds number increase. For "=25°, temperature and velocity measurements show in evidence the existence of a transition 2D-3D at a Reynolds number ReLc=2,7. 104. Thermal fields revealed a high degree of complexity linked both to the complex nature of the dynamic field and the off axis location of injection. Scalar transport and mixing are analysed as a function of the rear slant angle ". The mixing problem has been studied by considering successively variations of maximum values of temperature excess, maximum intensity of the temperature variance and dissipation rate of temperature variance. These results allowed to determine the mixing time and to estimate the pollutant concentrations received by particular receptors (pedestrian close to a road or car driver)
Faure, Thierry. « Méthodes expérimentales instationnaires et leurs applications en mécanique des fluides ». Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2009. http://tel.archives-ouvertes.fr/tel-00911074.
Texte intégralRobert, Julien. « Optimisation des transferts de chaleur et structures d'un écoulement fluide entre deux parois ondulées à géométrie variable : application aux échangeurs compacts ». Poitiers, 2006. http://www.theses.fr/2006POIT2252.
Texte intégralThis experimental approach concerns the study of the flows of air within wavy channels representing fin surfaces of aeronautics compact heat exchangers. The objective of this study is to understand and to analyse the dynamic and thermal mechanisms which develop within these complex geometries. A very particular attention was turned on the characterization of the phenomena of transfers in walls. Results show the influence of geometric no dimensional parameters on the organization of internal flow: factor of distance, factor of wave and phase. Flow is the seat of the development of boundary layers characterized by successive points of detachment and reattachment. These phenomena are at the origin of strong gradients of wall stress in good correlation with the also important variations of local heat exchanges. Empirical laws are offered for high Reynolds numbers. The fine analysis of results allows offering an optimum geometry. These works show that the mean and fluctuating flow is established beyond the 4th period of wave. The development of turbulent structures and the level of turbulence is independent of the initial rate of turbulence, but depend closely on geometric dimensions of the wavy channel and the regime of internal flow
Ouayahya, Nadir. « Analyse expérimentale de l'entrée en décrochage tournant d'un compresseur axial ». Paris 6, 2009. http://www.theses.fr/2009PA066290.
Texte intégralLalizel, Gildas. « Carctérisation expérimentale de l’aérodynamique d’un jet annulaire à très grand rapport de diamètres ». Rouen, 2004. http://www.theses.fr/2004ROUES053.
Texte intégralAnnular jet flows are mainly used in industrial processes (bluff body flows, glass fibber processes, …) but paradoxically represent a negligible part of fundamental jet flow studies. So, we are interested in an experimental study of the aerodynamic of an annular jet with a diameter ratio equal to 0. 91 (Do=53,88 mm et Di=48,75 mm). Velocities have been measured by Laser Doppler Velocimetry (L. D. V. ), Particle Image Velocimetry (P. I. V. ) and hot wire anemometry in the near field and in the far field until 10 Do diameters. A spatio-temporal study of the instabilities, which develop in the internal and external mixing layers in the recirculation zone, has been realized. The joint use of non time correlated P. I. V. Measurements, of Proper Orthogonal Decomposition (P. O. D. ) and of a local time resolved L. D. V. Measurement allow to determine a scenario of the temporal evolution of the wake. The fully developed merging zone has also been studied from L. D. V. And hot wire anemometry measurements. The variation of integral quantities (momentum, flow rates, velocities, half widths of the jet, turbulent Reynolds numbers), turbulent scales (Kolmogorov, Taylor and integral scales) and mean dissipation rates have been measured on the axis of the flow. A comparison of the variation of these quantities allows to include the round jet as an asymptotic case of the annular jets
Sorg, Brian Stuart. « Laser-assisted tissue closure with a unique solder-film patch / ». Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3008450.
Texte intégralRobert, Kévin. « Débitmétrie d'air dans la ligne d'admission d'un moteur diesel suralimenté : Caractérisation des phénomènes aérauliques au niveau du débitmètre ». Rouen, 2005. http://www.theses.fr/2005ROUES052.
Texte intégralFor Diesel engine, air flow metering is a key point to meet the future European pollutant regulations. In cooperation with the research laboratory CNRS CORIA UMR 6614 and the CERTAM, RENAULT led an experimental study whose objectives are to analyse and to understand the air flow velocity field inside the hot-film air mass sensors (HFM). Tests have been carried out on a flow bench and on an engine test bench to characterize the influence of HFM upstream shape devices (vehicle air filters, straight pipe, homogeneous grid) and the exhaust gas recirculation valve opening) on air flow phenomena. Velocities have been measured inside the air intake system by laser Doppler anemometry (LDA) and hot wire anemometry (HWA). Data synchronization between LDA and HWA velocity measurements and a reference of the air intake engine cycle was applied to reveal local and flowrate phase velocity and to quantify the local velocity stability by standard deviation analysis. As a result, the knowledge of air intake flow characteristics helped the design of low pressure devices in order to improve mass air flow measurements by the HFM sensor. Besides, associated improvements of mass air flow signal processing in the engine control unit resulted in an enhancement of engine devices behaviour
Larass, Nikos. « Caractérisation expérimentale des champs thermiques et dynamiques de la combustion dans une chaudière domestique modèle ». Rouen, 2000. http://www.theses.fr/2000ROUES004.
Texte intégralDonazzan, Alberto. « Heterodyne laser interferometers for the dimensional control of large ring-lasers ». Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3423163.
Texte intégralIl presente lavoro riporta il progetto, l’implementazione e la caratterizzazione di un interferometro laser a eterodina per applicazioni metrologiche sub-nanometriche. Le analisi e l’attività sperimentale legate a questa tesi fanno parte di uno studio più ampio, indirizzato alla realizzazione di un sistema di metrologia esterna per l’impiego su estese strutture opto-meccaniche. L’obiettivo è il controllo della geometria tridimensionale di un insieme di grandi giroscopi laser, destinato a futuri esperimenti nell’ambito della Relatività Generale. Il massimo livello di incertezza dimensionale tollerabile corrisponde a 10^-11 m, che va raggiunto su distanze operative di 7m e mantenuto per periodi di diversi giorni. La soluzione proposta consiste in una configurazione MachZehnder non polarizzante, che include un circuito ottico di annullamento e un peculiare specchio forato. Lo schema permette l’interrogazione della distanza di interesse tramite il posizionamento dello strumento fra i due punti fiduciari che la definiscono. Si descrivono qui il principio di funzionamento alla base del sistema, il metodo di estrapolazione della fase e tutta la strumentazione utilizzata per l’esperimento. Le diverse sorgenti di errore sono trattate analiticamente e, ove possibile, identificate sperimentalmente. Lo strumento di misura realizzato è stato testato con sessioni di acquisizione lunghe fino a 300min, mostrando prestazioni a livello del nanometro per frequenze decrescenti fino a 100mHz. Variazioni nell’indice di rifrazione dell’aria e instabilità meccaniche sono ad ora i principali fattori che limitano le prestazioni del sistema alle basse frequenze. L’esperimento ha messo in luce diverse problematiche tecniche, che costituiranno un prezioso bagaglio di esperienze, utile per il futuro avanzamento dell’attività di ricerca.
Albugues, Laurent. « Analyse expérimentale et numérique d'un jet débouchant dans un écoulement transverse ». Toulouse, ENSAE, 2005. http://www.theses.fr/2005ESAE0001.
Texte intégralDelhuille, Rémi. « Interférométrie atomique avec l'atome de lithium : Réalisation d'un interféromètre présentant un contraste et un flux élevés en vue de mesures de précision ». Phd thesis, Université Paul Sabatier - Toulouse III, 2002. http://tel.archives-ouvertes.fr/tel-00002371.
Texte intégralGodard, Gilles. « Etude expérimentale de la structure du champ d'un scalaire passif dans une allée de Benard-Von Karman ». Rouen, 2001. http://www.theses.fr/2001ROUES011.
Texte intégralBoreland, Matt School of Electrical Engineering UNSW. « Laser Crystallisation of Silicon for Photovoltaic Applications using Copper Vapour Lasers ». Awarded by:University of New South Wales. School of Electrical Engineering, 1999. http://handle.unsw.edu.au/1959.4/17190.
Texte intégralWu, Jianfeng. « Thulium Doped Microsphere Laser and Fiber Laser ». Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1369%5F1%5Fm.pdf&type=application/pdf.
Texte intégralBarre, Cyril. « Jet en écoulement transversal : observations expérimentales et numériques ». Nancy 1, 1998. http://www.theses.fr/1998NAN10277.
Texte intégralDanlos, Amélie. « Dynamique des jets contrôlés : Application à l’étude du mélange dans des écoulements de jets annulaires à très grand rapport de diamètres ». Phd thesis, Rouen, 2009. http://www.theses.fr/2009ROUES055.
Texte intégralBoutouili, Mohieddine. « Etude statistique expérimentale d'une combustion turbulente en couche limite ». Poitiers, 1988. http://www.theses.fr/1988POIT2336.
Texte intégralAraujo, Viana Carlos. « Développement technologique et intégration système de VCSEL et HPT SiGe pour des applications radio-sur-fibre 60 GHz bas coût ». Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1003/document.
Texte intégralWireless communication technologies have become one of the most popular and indispensable part of people's lives in the recent years, offering mobility and services never before available from mobile communication until local network communication. This work is based on the frame of the French ORIGIN project and intended to explore the Home Area Network using the most recent Wi-Fi standard at 60 GHz with the goal to present a solution for the upcoming days where MultiGbit/s wireless communication will be required. The ORIGIN solution is characterized by the complementary action of two technologies: 60 GHz Wireless communication and Radio-over-Fiber (RoF) infrastructure. The project pretends to propose a real prototype based on RoF transducers and a Multipoint-to-Multipoint architecture to cover the entire house. This thesis covers from the single optoelectronic chip devices until the system implementation and the final demonstrator. The light source and the photodetector choice were very important since it dictated the RoF transducer architecture. Our choice was on 850 nm multimode devices (GaAs VCSEL and SiGe HPT) which allow relaxed constraints on the optical packaging and, therefore, low cost solutions. In terms of performances those devices are limited in a few tens of Gigahertz of bandwidth which was the reason for the intermediate frequency (IF) architecture. This thesis work addressed the electrical and optical interconnection of the optoelectronic chip devices. It explored the integration of hybrid amplification stages and passive networks within optoelectronic receivers and emitters. The optical packaging issues were addressed through a conventional coupling technique using a ball lens first. The die device performances were evaluated and compared with a packaged module in terms of frequency response, noise and nonlinearities. Since performances are usually measured as link performances we proposed a definition of the Opto-microwave figures of merit, such as Opto-microwave gain, noise, nonlinearities and EVM. They are presented and integrated into behavioral models, allowing both the individual performances extraction and system design. The integration of the RoF module in the system is the final part of this thesis. The performances were measured and simulated at each integration step. The final demonstrator based on the multipoint-to-multipoint architecture was implemented using an optoelectronic central node for the signal repartition and the Green Box for signal controlling. Real-time bidirectional transmission between two commercial WirelessHD devices at ~3 Gbit/s was validated. In a final section directions to improve VCSEL and SiGe HPT are explored. 25 GHz analogue VCSELs are explored with a focus on their dimensions, improved access and the potential of a suited matching approach. A novel collective and passive optical coupling technology is also proposed for both VCSEL and top illuminated detectors that couple smaller and faster devices
Ailinger, Kevin Gerard. « Measurements of surface shear stresses under a three-dimensional turbulent boundary layer using oil-film laser interferometry ». Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-11012008-063040/.
Texte intégralSalhi, Mohammed Adnan. « Confocal THz laser microscope ». Göttingen Sierke, 2009. http://d-nb.info/999104071/04.
Texte intégralGatti, Nicola. « Laser diagnostics of non-equilibrium plasmas ». Doctoral thesis, Università degli studi di Trento, 2018. https://hdl.handle.net/11572/367593.
Texte intégralLalizel, Gildas. « Caractérisation expérimentale de l'aérodynamique d'un jet annulaire à très grand rapport de diamètres ». Phd thesis, Université de Rouen, 2004. http://tel.archives-ouvertes.fr/tel-00012179.
Texte intégralLes instabilités se développant dans les couches de mélange externe et interne de la zone de recirculation ont été résolues spatialement et temporellement. L'utilisation conjointe de mesures P.I.V. décorrélées en temps de la zone de recirculation, de la P.O.D. et d'une mesure temporelle locale par A.D.L. a permis d'établir un scénario de l'évolution temporelle du sillage.
La zone de jet pleinement développé a également été étudiée à partir de mesures d'A.D.L. et de fil chaud. Les évolutions des grandeurs intégrales (quantité de mouvement, débit, vitesses, demi largeur du jet, nombre de Reynolds turbulent), des différentes échelles (échelles de Kolmogorov, de Taylor et intégrale) et du taux de dissipation moyen ont été mesurées sur l'axe du jet. Une comparaison des variations de ces différentes grandeurs a permis d'inclure le jet rond comme un cas asymptotique des jets annulaires.
Gatti, Nicola. « Laser diagnostics of non-equilibrium plasmas ». Doctoral thesis, University of Trento, 2018. http://eprints-phd.biblio.unitn.it/2797/1/PhD_thesis_Gatti.pdf.
Texte intégralGarza, Ezra. « Pulsed Laser Deposition of Thin Film Heterostructures ». ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/459.
Texte intégralDiop, Moussa. « Transition à la turbulence en écoulements compressibles décollés ». Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0473/document.
Texte intégralResearch dedicated to the study of the unsteadiness of turbulent Shock Wave Boundary Layer Interaction (SWBLI) has allowed a detailed description of this kind of interaction both experimentally and numerically. Several scenario were proposed to explain the low frequency unsteadiness observed in separated SWBLI. Nevertheless, the literature on this kind of flow involving either upstream laminar or transitional conditions is quite reduce. Within the framework of the European TFAST program, an important effort was made to develop experimental devices, in conjunction with numerical simulations, allowing a detailed study of these laminar or transitional configurations. In particular, within the framework of this thesis, a shock wave reflection configuration on a laminar boundary layer was set-up, with a nominal free stream Mach number of 1.68. Using classical metrology (Laser Doppler Anemometry, Hot WireAnemometry) that have been adapted to these particular experimental conditions, we have been able to describe the spatio-temporal properties of the interaction. The mean field has been characterized and compared with the classical theories and the results obtained in other configurations.A model describing the transition mechanisms to turbulence within the interaction has been developed. Its sensitivity to upstream conditions was studied by placing perturbations upstream of the interaction. In all cases, convective (high frequency) and stationary (low frequency) unsteadiness were observed and compared with those existing for upstream turbulent configurations. An intermediate range of convective unsteadiness (medium frequency) has been demonstrated and characterized
Camano, Schettini Edith Beatriz. « Étude expérimentale des jets coaxiaux avec différences de densité ». Grenoble INPG, 1996. http://www.theses.fr/1996INPG0066.
Texte intégralCheymol, Benjamin. « Développement des instruments de mesures des profiles transversaux et d'emittance pour l'accélérateur linéaire LINAC4 au CERN ». Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00877031.
Texte intégralRebegea, Simina Aurelia. « Nanosecond laser ablation of thin film material libraries ». Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8555/.
Texte intégralMacLeod, Allan M. « Measurements of FEL dynamics ». Thesis, Abertay University, 1999. https://rke.abertay.ac.uk/en/studentTheses/6a8f24a4-0ee4-4701-80a9-ce92492f69fa.
Texte intégralGharba, Ahmed. « OFDM et allocation des ressources dans les nouvelles générations des réseaux d'accès optiques pour des systèmes mono et multi-utilisateurs ». Rennes, INSA, 2012. http://www.theses.fr/2012ISAR0008.
Texte intégralOptical access networks are essential to meet overgrowing demands of bandwidth and to facilitate the future telecom services. Lt presents an interesting solution for broadband access networks compared to DSL technology which has a limited data rate as weil as a short geographical reach eligibility. Actual optical access networks solutions are based on classical and simple NRZ (Non Return to Zero) modulation technique of the signal in the optical domain. Recently, Orthogonal Frequency Division Multiplexing (OFDM) modulation has been proposed to better exploit the capacity of the optical channel. Coupled with resources allocation techniques, OFDM transmission takes into consideration the channel quality in order to maximize the overall data rate. This thesis experimentally implements OFDM coupled with bit and power allocation algorithms in a downstream Next Generation PON (NG-PON) architectures. First, OFDM coupled with Levin-Campello algorithm so called Adaptively Modulated Optical OFDM (AMOOFDM) is presented for single user OFDM-based systems. Then, another technique Optimal Spectrum Balancing (OSB) is used for resource allocation in multi-user OFDM-based systems. Lmplementing OSB, Multi-Band OFDM (MB-OFDM) has been experimentally demonstrated, then a comparison is made between MB-OFDM and Orthogonal Frequency Division Multiple Access (OFDMA) both using OSB algorithm. The impact of the laser chirp and optical fibre chromatic dispersion on transmission performance is studied as weil as a comparison is made between APD and PIN photodiodes both using AMOOFDM signal
Bie, Robert Adriaan de. « Efficacy of 904 NM laser therapy in acute lateral ankle sprains ». Maastricht : Maastricht : Universiteit Maastricht ; University Library, Maastricht University [Host], 1998. http://arno.unimaas.nl/show.cgi?fid=6059.
Texte intégralLu, Kuan. « Optimization Of Sublimation Conditions for Surface Layer Matrix-assisted Laser Desorption Ionization Time of Flight Mass Spectrometry Imaging (SL-MALDI- Tof MSI) of Polymer Surfaces ». University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1524846943404769.
Texte intégralAnderson, Eric J. « Total ship integration of a Free Electron Laser (FEL) ». Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA322386.
Texte intégralThesis advisor(s): Charles N. Calvano, W.B. Colson. "September 1996." Includes bibliographical references (p. 49-51). Also available online.
Farrar, Simon Richard. « Excimer laser ablation characterisation for superconducting thin film applications ». Thesis, University of Hull, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282366.
Texte intégralBas, Derek. « Laser Beam Steering with Thin Film GaAs on Plastic ». Bowling Green State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1277119321.
Texte intégralLee, Wen-Chieh. « Thin film adhesion measurement using excimer laser ablation test / ». Online version of thesis, 1991. http://hdl.handle.net/1850/11034.
Texte intégralLombini, Matteo <1977>. « Laser guide stars wavefront sensors for the EELT ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3706/1/Lombini_Matteo_tesi.pdf.
Texte intégral