Dissertations / Theses on the topic 'Laser Diagnostics'
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Stewart, Neil Andrew. "Novel multifunctional laser diagnostics." Thesis, University of Dundee, 2013. https://discovery.dundee.ac.uk/en/studentTheses/ddee58ac-0fda-41ca-9485-c74920cf3852.
Full textDelserieys, A. "Optical diagnostics of laser plasmas." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492152.
Full textJing, Cao. "Spray diagnostics by laser diffraction." Thesis, University of Sheffield, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321852.
Full textBuckley, Alastair. "Laser diagnostics of discharge lamps." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322979.
Full textHuang, Ping. "Diagnostics in VUV laser spectroscopy." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/2244.
Full textA tunable vacuum ultra-violet (VUV) laser source was recently developed for VUV spectroscopy using state selective excitation and total fluorescence detection. The VUV laser source makes use of a four-wave mixing process to provide tunable VUV radiation for the electronic excitation of the molecules. The theory of four-wave mixing, with the emphasis on parameters that are important for our experimental setup to generate efficient tunable VUV radiation is discussed. The experimental setup, and in particular the metal vapor heat-pipe, which provides Mg vapor as the nonlinear medium, is described. New diagnostic equipment described in this work was added to the experimental setup. This equipment was characterized and utilized together with the existing setup. The additional diagnostic equipment introduced enabled us to measure the tunable VUV output of the source (using a VUV monochromator), making it possible to significantly improve the efficiency of the existing tunable VUV laser source.
Williams, Benjamin Ashley Oliver. "Quantitative laser diagnostics for combustion." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:37ea0034-03ac-4021-80e3-5d72200fbd0e.
Full textAndersson-Engels, Stefan. "Laser-induced fluorescence for medical diagnostics." [Lund : KF-Sigma], 1990. http://catalog.hathitrust.org/api/volumes/oclc/39070261.html.
Full textStevens, Robert Edward. "Laser-induced grating techniques for combustion diagnostics." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413212.
Full textGrant, Andrew J. "Laser diagnostics of spark-ignited combustion systems." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343481.
Full textCharalampous, Georgios. "Laser induced fluorescence diagnostics in multiphase flows." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508321.
Full textSuaidi, Mohamad Kadim bin. "High-speed optical diagnostics of laser-interactions." Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/25627.
Full textBush, Roger. "Novel nonlinear laser imaging techniques for combustion and flow." Thesis, Cranfield University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309665.
Full textHanna, Sherif Fayez. "Electronic resonance enhanced coherent anti-Stokes Raman scattering technique for detection of combustion species and biological molecules." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4379.
Full textSasoh, Akihiro, Koichi Mori, Kohei Anju, Koji Suzuki, Masaya Shimono, and Keisuke Sawada. "Diagnostics and Impulse Performance of Laser-Ablative Propulsion." American Institite of Physics, 2008. http://hdl.handle.net/2237/12005.
Full textWalton, Barney Richard. "Optical diagnostics of laser plasma particle acceleration experiments." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418083.
Full textAhmad, Zahrah. "Optical and particle diagnostics in laser produced plasma." Thesis, University of Essex, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316211.
Full textHumphries, Gordon S. "Novel diode laser absorption techniques for combustion diagnostics." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28843.
Full textBajlekov, Svetoslav. "Towards a free-electron laser driven by electrons from a laser-wakefield accelerator : simulations and bunch diagnostics." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:99f9f13a-d0c2-4dd8-a9a4-13926621c352.
Full textLi, Xuesong. "Multi-dimensional Flow and Combustion Diagnostics." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/48894.
Full textPh. D.
Lloyd, Geraint M. "Four wave mixing techniques and applications in combustion diagnostics." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363830.
Full textWillman, Christopher. "Laser diagnostics for spatially resolved thermometry in combustion and flows." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:fc0cbf95-302f-4de7-9212-6afa2632c93a.
Full textKaminski, C. F. "Novel laser techniques for diagnostics of plasmas and flames." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294362.
Full textArokiam, Ivan Christy. "Rapid laser cutting : beam diagnostics, monitoring and performance evaluation." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400196.
Full textWills, Jonathan B. "Laser diagnostics of chemical vapour deposition of diamond films." Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251103.
Full textXu, Wenjiang. "Three Dimensional Laser Diagnostics for Turbulent Flows and Flames." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/79912.
Full textPh. D.
Hofmann, Arnulf Maximilian. "Laser-induced incandescence for soot diagnostics at high pressure." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:16-opus-70340.
Full textMann, Berenice Ann. "Novel coherent laser spectroscopic techniques for minor species combustion diagnostics." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304258.
Full textAnselmo, Filho Pedro. "Experimental investigations of turbulent stratified V-flames using laser diagnostics." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611162.
Full textMeor, Zulkifli Meor Mohd Faisal. "Characterisation of oxy-fuel flames using laser based diagnostics techniques." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/45360.
Full textYan, Xiaoling. "Ultra-fast photon and electron beam diagnostics for free electron lasers." Thesis, Abertay University, 2003. https://rke.abertay.ac.uk/en/studentTheses/4a05ee9c-2ddb-434f-b2a1-0ad483394db8.
Full textBai, Xueshi. "Laser-induced plasma as a function of the laser parameters and the ambient gas." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10333/document.
Full textLaser-induced breakdown spectroscopy (LIBS) has been invented for more than 50 years, which analyzes the spectrum of the laser-induced plasma to determine the elemental composition of the ablated sample. Recently, LIBS technique has been well developed and applied in different domains, for example oceanic exploration, pollution monitoring in the environment. LIBS uses the ablation plasma as a light source that contains the elemental composition information of the sample. However, the laser-induced plasma exhibits a transient behavior. Although time-resolved and gated detection can greatly improve the performance of the LIBS technique especially that of calibration-free LIBS (CF-LIBS) with a better determination of plasma temperature, the temporal evolution of the plasma is correlated to its morphology and its spatial inhomogeneity. The determination of the morphology as well as the internal structure of the plasma together with their evolution during plasma expansion into the ambient gas is therefore crucial for the optimization of the use of ablation plasma as a spectroscopic emission source. Evolutions of the morphology and the internal structure of the ablation plasma are considered as the consequence of its hydrodynamic expansion into the ambient gas. Following the thesis of Qianli Ma which has studied the effect of laser wavelength on the behavior of the plasma induced in an ambient gas of argon, the present thesis has used the same diagnostic techniques (time- and space-resolved emission spectroscopy and fast spectroscopic images) together with 1064 nm ns laser pulse ablation of a target of aluminum to investigate the effects of other parameters, such as the fluence and the duration of laser pulse, the effect of different ambient gases (argon and air), on the morphology and internal structure of the plasma. Furthermore, in order to understand the effects of these parameters on the properties of the plasma, the microscopic mechanisms during post ablation and the propagation of the plasma are also studied. While the plasma cools down in air, molecules are formed, AlO for instance. So the thesis also studied the condition for the formation of the molecules in the plasma. Beyond the practical interest of this study for LIBS, it provides also insights to the kinetics of the AlO molecule formation in laserinduced plasma
Hendron, Jacqueline Mary. "Ion probe and optical spectroscopy studies of low temperature laser produced-plasmas." Thesis, Queen's University Belfast, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337038.
Full textLade, Robert James. "Pulsed ultraviolet laser ablation of carbon containing targets." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302156.
Full textRoussillo, Mathieu. "Development of optical diagnostics for soot particles measurements and application to confined swirling premixed sooting flames under rich conditions." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLC060/document.
Full textThe control of soot particles production represents today a major industrial issue because of their harmful impact on both the climate and the human health and their strong contribution to the radiative transfers. To better understand and control the production of these polluting emissions, it is essential to improve our knowledge on this subject in a turbulent burner. The objective of this Ph.D. is to set up optical diagnostics for the study of turbulent flames and to experimentally characterize soot production in a new academic turbulent premixed combustion configuration while approaching industrial configurations, generally confined and swirled flows. For this, a laminar experimental configuration is first considered to validate the implementation of the Laser Induced Incandescence (LII) technique to measure the soot volume fraction fv. This burner designed at Yale University allows the stabilization of a laminar ethylene/air diffusion flame. This burner has been widely studied in the literature, so that it is possible to compare the quality of our measurements with the results of different international teams. Through collaborations with the UPMC, we calibrated the LII signal with the MAE (Modulated Absorption Emission) technique, making it possible to quantitatively measure fv and to compare the MAE and LII techniques. Finally, the burner was equipped with a loudspeaker to modulate the flow and to study the effects of a controlled perturbation on the soot production, thus approaching the unsteady phenomena characteristics of turbulent flows. Finally, the effects of the enlargement of the laser sheet on LII results were also investigated in order to be able to apply this diagnostic technique in an innovative large turbulent configuration. This experimental configuration, called EM2Soot, was developed to measure the production of soot in a turbulent swirled rich confined premixed ethylene/air flame. This burner makes it possible to independently quantify the effects of the equivalence ratio, the total flame power and the thermal environment on the total soot production. A representative operating point was then characterized, in parallel with LII measurements, Particle Image Velocimetry (PIV) and Laser Induced Phosphorescence (LIP) techniques have been employed in order to characterize the effect of the turbulence on soot production and to establish a database for the validation of future numerical simulations. Finally, the geometry of the burner has been modified allowing a different stabilization of the flame (V flame shape). A new operating point is then studied in order to highlight the role of the injector geometry on the stabilization of the flame and, consequently, on the total soot production
De, Groot Wim A. (Wim Adrianus). "Laser Doppler diagnostics of the flow behind a backward facing step." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/15801.
Full textNew, M. J. "Laser development and novel applications of polarization spectroscopy for combustion diagnostics." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339088.
Full textCowpe, John Stephen. "Optical emission and mass spectrometric diagnostics of laser-induced silicon plasmas." Thesis, University of Salford, 2008. http://usir.salford.ac.uk/2571/.
Full textWinters, Caroline. "Laser Diagnostics of Reacting Molecular Plasmas for Plasma Assisted Combustion Applications." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503306596261748.
Full textWerquin, Olivier. "Diagnostics de scalaires par plan laser dans des jets diphasiques denses." Rouen, 2001. http://www.theses.fr/2001ROUES038.
Full textKhodakovskiy, Nikita [Verfasser]. "Methods of ultra-fast laser contrast diagnostics and optimization / Nikita Khodakovskiy." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/120492693X/34.
Full textSerafini, Stefano. "Quality control agent: self-adaptive laser vibrometry for on line diagnostics." Doctoral thesis, Università Politecnica delle Marche, 2013. http://hdl.handle.net/11566/242695.
Full textVibration testing is a well established procedure for assessing the conformity to specifications of a variety of products, which contain moving parts. Typically at the end of an assembly line, a vibration test provides useful information for 100% quality control of products before packaging. In the appliance manufacturing sector vibration testing for online quality control is increasingly important. Laser Doppler Vibrometry (LDV) has been already used to perform such tests on-line and it has become an established measurement technique. In modern manufacturing industry flexibility and adaptability are key factors for the improvement of efficiency of production processes; both process control and product quality control depend on the availability of reliable information, and therefore on the quality of the data measured. For its non-contact nature and for its metrologic performance, laser vibrometry plays a more and more important and crucial role. This technique allows to realize flexible measurement systems that can implement adaptive and modular algorithms, comprising a large number of ready to use tools. In this thesis we will describe how it is possible to improve the performance of such systems by implementing self-adaptation and reconfigurability behaviors of the laser vibrometer aimed to reduce measurement uncertainty. Such behaviors are achieved by adding scanning mirrors and a dedicated camera, thus realizing a scanning LDV, which can displace the measurement beam at different locations. Self-adaptation (local adaptation) consists in the following behaviors: the system aims at the desired target point over the washing machine (WM) by displacing the laser beam so to compensate effects of WM mis-positioning due to production line inaccuracies. After this preliminary phase, the automatic search for sufficiently large Doppler signal starts. The system searches for an optimal optical signal by slightly displacing the laser beam in the surrounding of the desired target point thus optimizing measurement uncertainty. The system can support also reconfigurability (global adaptation), which consists in the possibility to plug-in/plug-out different post-processing algorithms for a deeper analysis of vibrations. For different production scenarios different diagnostic algorithms are chosen. This modular approach allows to consider the scenario of the production line and the quality of the operations carried out on the production line before the end product is made. In order to successfully use the self adaptation behavior to increase measurement accuracy, for this thesis a deep research of the causes correlated to uncertainty in industrial diagnostic has been made. It this work it is shown how the RMS amplitude of the Doppler signal (signal quality - SQ) is strictly correlated to measurement uncertainty, when SQ decreases then uncertainty affects the vibration velocity signal. Experimental data allow to say that SQ value is correlated to the morphology of the target surface and for a short period of time (10-15 s), so during the vibration the SQ value depends only on X-Y position of the laser beam on the target surface. These facts allow to use the SQ function as a cost function and the decrease the measurement uncertainty is a problem correlated to the optimization of the SQ value during the vibration measurements. The optimization strategy for the measurement enhancement achieved by the down-hill algorithm (Nelder-Mead algorithm) and its effect on signal quality (SQ) improvement are discussed. ii With these features, this system is designed as a Quality Control Agent (QCA) and it is part of a Multi Agent System (MAS) that supervises all the production line. This thesis also shows the data exchange between the measurement system and other agents in order to realize a decentralized manufacturing system. In fact, in a distributed system, the estimation of the confidence level of the information provided by other agents plays an important role. The QCA associated to the measurement system has to be able to understand the confidence level of the diagnostic results provided. To understand the confidence level of the diagnostic information extracted from a feature, an uncertainty estimate model applied to a vibration signal acquired from a washing machine has been conceived and implemented. In this way, the QCA can provide the overall diagnosis for the WM and estimate the uncertainty level with which the diagnosis has been performed. These information are used by the independent meta agent (IMA) to perform a trend analysis and elaborate suggestions and warnings to improve the process and product execution.
Boëdec, Thomas. "Caractérisation d'un spray dense et à grande vitesse par diagnostics optiques." Ecully, Ecole centrale de Lyon, 1999. http://bibli.ec-lyon.fr/exl-doc/TH_T1822_tboedec.pdf.
Full textThe present work is a contribution to the experimental characterisation of a dense and high speed spray, by means of optical diagnostics : one-point measurements - Phase Doppler Anemometry (PDA) - and planar visualisation measurements - Particle Image Velocimetry (PIV) and Digital Image Processing (DIP) -. A steady state spray is produced by discharge of pressurised water at 10 MPa through a 0. 2 mm diameter hole. The spray discharges into quiescent air, at atmospheric pressure and ambient temperature. With PDA measurements, five criteria defining the transition from a dense flow to a fully developped flow (similar to an airjet laden with droplets) have been established, based on : (i) the asymptote reached by the mean velocity on the axis ; (ii) the linear evolution of the air entrainment ; (iii) the equilibrium reached by the fluctuating velocity ; (iv) the linear evolution of the mean-squared displacement ; (v) the linear evolution of the integral thickness. The adaptation of PIV to the study of this dense spray necessitates numerous preliminary experiments concerning the illumination of the droplets (two opposite coplanar laser sheets), the choice of time interval between two images, the interrogation spot size for the cross-correlation process. . . DIP gives droplets size results which are in good agreement with the ones issued from the PDA measurements. An original investigation combining PIV and DIP allows to study the droplets velocity (10 to 100 m/s) conditioned by their size (a few um). Finally, with the fluoresced and diffused light simultaneously recorded on two CCD cameras, the previous analysis by PIV and digital image treatment gives encouraging results on the continuous phase dynamic : differences in longitudinal velocity of about 30 m/s between the two phases were measured on the axis. Future prospects are the quantitative analyses of the gas velocity conditioned by droplets velocity or droplets geometry
Jiang, Naibo. "Development of high repetition rate no planar laser induced fluorescence imaging." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1150140816.
Full textPhaneuf, Christopher. "Infrared laser-mediated polymerase chain reaction in a polymer microfluidic device." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53068.
Full textAgarwal, Tapish. "Development of diagnostics for the experimental studies of ignition in sprays." Phd thesis, Ecole Centrale Paris, 2013. http://tel.archives-ouvertes.fr/tel-00969174.
Full textFigueiredo, Augusto César Ribeiro. "Fluorescência no diagnóstico da cárie." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-20112014-111624/.
Full textThe introduction of new tools in medicine has promoted an important interdisciplinar activity. In Dentistry, the improvement induced by this new technology is mainly observed at caries detection. Until now, the fluorescence procedure for caries detection is based on the investigation of only a specific region of the fluorescencespectrum. From this analysis the presence of caries or healthy tissues is inferred. However, all the fluorescence spectrum must be evaluated and not only a small part of it. The collected information will be important to the caries diagnosis. In this work we propose two ways to process the fluorescence spectrum in order to obtain a more accurate diagnosis. In this way, we study the fluorescence behavior of health enamel and healthy and decayed dentin. The fist way to process the fluorescence here proposed is obtained by the ratio of inelastic peak and elastic peak and the second one, the ratio of the inelastic and elastic areas. It were investigated human teeth with healthy enamel, decayed and healthy dentin surfaces at the same sample. The fluorescence was induced by three lasers excitation: 442nm, 532nm and 632nm. Ali the used wavelengths showed to be efficient for caries detection, however 442nm and 632nm presented better contrasts. A second study was performed, when the fluorescence of healthy enamel was investigated using a commercial device (Diagnodent®) previously and after Er: YAG irradiation. It was demonstrated that this device can present divergent results showing a caries diagnosis for a healthy irradiated enamel surface. This result identifies a problem when a single wavelength is evaluated from all the fluorescence spectrum
Patton, Randy Alexander. "Characterization and Improvements of Filtered Rayleigh Scattering Diagnostics." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1373465741.
Full textHall, Ross Douglas. "Influence of Obstacle Location and Frequency on the Propagation of Premixed Flames." University of Sydney, 2008. http://hdl.handle.net/2123/2795.
Full textTurbulent propagating premixed flames are encountered in spark ignition engines, gas turbines, industrial burners, as well as in vented gas explosions. In all these applications, the flame fronts interact with complex solid boundaries which not only distort the flame structure but directly affect the propagation rate in ways that are not yet fully understood. This thesis aims to provide both a quantitative and qualitative understanding of the link between overpressure, flame front wrinkling and turbulence levels generated in the propagating medium. This is an issue of importance for the provision of improved sub-models for the burning rates of premixed flames. An experimental chamber was constructed where controlled premixed flames were ignited from rest to propagate past solid obstacles and/or baffle plates strategically positioned in the chamber. Laser Doppler Anemometry was used to measure the velocity field and turbulence fields while pressure transducers were used to obtain pressure-time traces. In addition to this Laser-Induced Fluorescence of the Hydroxyl radical is was to image the flame front as it consumes the unburnt fuel captured in the re-circulation zone behind the main obstruction. The thesis reports on the effects of various parameters such as the inclusion of grids and obstructions, blockage ratio, and repeated obstacles to explore possible correlations between the pressure and the flow-fields. Pressure, velocity and LIF images were correlated and analysed to prove the significance of grid location and number on overall turbulence intensity. Corresponding flow field parameters such as flame front wrinkling, peak overpressure and RMS all combine to conclusively demonstrate their interaction and influence to turbulence intensity. By progressively positioning more grids further downstream, consequent rises in the flow field parameters and the establishment of positive trends indicates the overall significance of kernel development and flow disturbances in relation to turbulence generation.
Smith, James Anthony. "Laser diagnostics of a diamond depositing chemical vapour deposition gas-phase environment." Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247541.
Full textAudebert, Patrick. "Diagnostics spectroscopiques d'un plasma créé par laser : utilisation des raies satellites diélectroniques." Paris 11, 1985. http://www.theses.fr/1985PA112176.
Full textThis thesis is a theoritical and experimental study of dielectronic satellites of the hydrogen-like lyman-α line in laser created plasmas. The use of performing experimental methods enabled the measurement of the localized X ray emission in the plasma conduction zone. We deduced the electronic density and temperature of the plasma along the laser axis from experimental spectra. The characteristics of the plasma being determined, we verified the validity of the predicted satellite line intensities by comparison to experimental results. The good agreement obtained confirmed the various theoretical models used and showed the importance of taking into account reabsorption effects