Thèses : « Laser Profiler »

1

Meece, Adam. « Laser Guided Navigation System for the Automated Floor Profiler – String Walker Edition ». University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491557571704528.

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Ghauri, Farzan Naseer. « Hybrid Photonic Signal Processing ». Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3233.

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This thesis proposes research of novel hybrid photonic signal processing systems in the areas of optical communications, test and measurement, RF signal processing and extreme environment optical sensors. It will be shown that use of innovative hybrid techniques allows design of photonic signal processing systems with superior performance parameters and enhanced capabilities. These applications can be divided into domains of analog-digital hybrid signal processing applications and free-space--fiber-coupled hybrid optical sensors. The analog-digital hybrid signal processing applications include a high-performance analog-digital hybrid MEMS variable optical attenuator that can simultaneously provide high dynamic range as well as high resolution attenuation controls; an analog-digital hybrid MEMS beam profiler that allows high-power watt-level laser beam profiling and also provides both submicron-level high resolution and wide area profiling coverage; and all optical transversal RF filters that operate on the principle of broadband optical spectral control using MEMS and/or Acousto-Optic tunable Filters (AOTF) devices which can provide continuous, digital or hybrid signal time delay and weight selection. The hybrid optical sensors presented in the thesis are extreme environment pressure sensors and dual temperature-pressure sensors. The sensors employ hybrid free-space and fiber-coupled techniques for remotely monitoring a system under simultaneous extremely high temperatures and pressures.
Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD

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Lam, Norris. « Modeling rating curves from close-range remote sensing data : Application of laser and acoustic ranging instruments for capturing stream channel topography ». Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-142135.

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A rating curve provides a functional relationship between water height (i.e. stage) and discharge at a specified cross-section in a river. Used in combination with a time series of stage, rating curves become one of the central components for generating continuous records of streamflow. Since developing and maintaining rating curves can be time consuming, hydraulic models have shown potential to reduce the effort required for developing rating curves. A central challenge with modeling procedures, however, is the acquisition of accurate stream channel and floodplain topography. From this perspective, this thesis focuses on the real-world application of close-range remote sensing techniques such as laser-based ranging technologies (i.e. Light detection and ranging or LiDAR) or acoustic based ranging technologies (i.e. acoustic Doppler current profiler or ADCP) to capture topographic information for hydraulic modeling applications across various spatial scales. First, a review of the current LiDAR literature was carried out to identify potential ways to take full advantage of these novel data and technologies in the future. This was followed by four interconnected studies whereby: (i) a low-cost custom laser scanning system was designed to capture grain size distributions for a small stream; (ii) synthetically thinned airborne laser scanning (ALS) data was applied in a physically-based hydraulic modelling framework to develop rating curves; (iii) low-resolution national-scale ALS was coupled with ADCP bathymetry to be used in conjunction with a hydraulic model to develop rating curves; and (iv) the impact of measurement uncertainties on generating rating curves with a hydraulic model were investigated. This thesis highlights the potential of close-range remote sensing techniques for capturing accurate stream channel topography and derive from these data, the necessary parameters required for hydraulic modeling applications.
En avbördningskurva tillhandahåller ett funktionellt förhållande mellan vattendjup (dvs. vattenstånd) och flöde vid ett specifikt tvärsnitt i ett vattendrag. Avbördningskurvan blir en central komponent för generering av kontinuerliga tidsserier av vattenföring från tidsserier av vattenstånd. Eftersom det är tidskrävande att utveckla och underhålla avbördningskurvor erbjuder hydrauliska modeller attraktiva möjligheter att minska den insats som krävs för att utveckla avbördningskurvorna. En central utmaning för sådana modelleringsförfaranden är emellertid tillgången till noggrann topografidata av strömfåran och de omgivande stränderna. Den här avhandlingen fokuserar på tillämpningen av fjärranalystekniker för avståndsmätning på nära håll, såsom laserbaserade teknik (dvs. Light detection and ranging eller LiDAR) och akustisk baserat teknik (dvs. acoustic Doppler current profiler eller ADCP), för att fånga topografisk information för hydraulisk modellering av vattendrag i olika rumsliga skalor. Först presenteras en litteraturstudie av den nuvarande LiDAR-litteratur för att identifiera potentiella sätt att dra full nytta av dessa nya data och tekniker i framtiden. Detta följs av fyra sammanlänkade studier: (i) tillämpning av ett lågkostnads-laseravsökningssystem för att fånga kornstorleksfördelningar i ett litet vattendrag, (ii) syntetiskt förtunnad flygburen laserskanningsdata (ALS) applicerad i en fysiskt baserad hydraulisk modell för att utveckla avbördningskurvor, (iii) lågupplösta ALS från Svensk nationell höjdmodell kopplade med ADCP-batymetri för att ta fram en avbördningskurva med en hydraulisk modell, och (iv) undersökning av effekterna av osäkerheter på mätdata för att generera avbördningskurvor med en hydraulisk modell. Denna avhandling belyser potentialen för fjärranalystekniker för avståndsmätning på nära håll, för att fånga strömfårans exakta topografi och ifrån dessa data härleda de parametrar som krävs för hydrauliska modelleringstillämpningar.

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Manuscript.

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Hoffman, Bradley R. « Evaluation of the Automated Laser Rut Measurement System Used by the Ohio Department of Transportation ». Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1321627068.

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Polidori, Guillaume. « Etude par visualisation de sillages tridimensionnels : application à un profil d'aile rectangulaire ». Poitiers, 1994. http://www.theses.fr/1994POIT2253.

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Ce travail s'inscrit comme une contribution a une meilleure connaissance des sillages a la fois instationnaires et 3d s'etablissant autour de profils limites en envergure par des plaques laterales. A titre d'exemple, nous etudions, par visualisations experimentales, l'ecoulement a l'aval d'un profil d'aile rectangulaire cale sous differentes incidences (=90, 60, 30), impulsivement mis en mouvement, dans la gamme de nombres de reynolds 650re3000. L'analyse est faite dans des sections regulierement reparties le long de l'envergure du profil. Pour ce faire, afin d'assurer la fiabilite des resultats, un dispositif optique original permettant l'obtention simultanee de plusieurs tomographies laser polychromatiques est mis en place. Par association de donnees quantitatives qui en sont deduites, et de visualisations globales, on montre dans le cas d'une aile a 90 d'incidence, comment s'installe dans le temps un courant transversal en provenance des plaques d'extremite, et comment il influence le processus de detachement tourbillonnaire. Une etude specifique de l'ecoulement parietal de jonction, notamment par reconstitution topologique, permet d'expliquer l'origine de ce courant transversal. L'influence du nombre de reynolds et de l'incidence du profil, sur les phenomenes observes, est analysee

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Zemzemi, Imene. « High-performance computing and numerical simulation for laser wakefield acceleration with realistic laser profiles ». Thesis, Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAX111.

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Le développement des lasers ultra-courts à de hautes intensités a permis l’émergence de nouveaux domaines de recherche en relation avec l’interaction laser-plasma. En particulier, les lasers petawatt femtoseconde ont ouvert la voie vers la possibilité de concevoir une nouvelle génération d’accélérateurs de particules. La modélisation numérique a largement contribué à l’essor de ce domaine d’accélération des électrons par sillage laser. Dans ce contexte, les codes Particle-In-Cell sont les plus répandus dans la communauté. Ils permettent une description fiable de l’interaction laser plasma et surtout de l’accélération par sillage laser.Cependant, une modélisation précise de la physique en jeu nécessite de recourir à des simulations 3D particulièrement coûteuses. Une manière pour accélérer efficacement ce type de simulations est l’utilisation de modèles réduits qui, tout en assurant un gain en temps de calcul très important, garantissent une modélisation fiable du problème. Parmi ces modèles, la décomposition des champs en modes de Fourier dans la direction azimutale est particulièrement adaptée à l’accélération laser plasma.Dans le cadre de ma thèse, j’ai implémenté ce modèle dans le code open-source SMILEI, dans un premier temps, avec un schéma différences finies (FDTD) pour discrétiser les équations de Maxwell. Néanmoins, ce type de solveur peut induire un effet de Cherenkov numérique qui corrompt les résultats de la simulation. Pour mitiger cet artéfact, j’ai également implémenté une version pseudo-spectrale du solveur de Maxwell qui présente de nombreux avantages en termes de précision numérique.Cette méthode est ensuite mise en oeuvre pour étudier l’impact de profils de lasers réalistes sur la qualité du faisceau d’électrons en exploitant des mesures réalisées sur le laser Apollon. Sa capacité à modéliser correctement les processus physiques présents est analysée en déterminant le nombre de modes nécessaires et en comparant les résultats avec ceux issus des simulations 3D en géométrie Cartésienne. Cette étude montre qu’inclure les défauts du laser mène à des différences dans les résultats et que ces derniers dégradent la performance des accélérateurs-laser plasma notamment en termes de quantité de charge injectée. Ces simulations, instructives pour les futures expériences d’accélération d’électrons par le laser Apollon, mettent en avant la nécessité d’inclure les mesures expérimentales dans la simulation et particulièrement celle du front de phase, pour aboutir à des résultats précis
The advent of ultra-short high-intensity lasers has paved the way to new and promising, yet challenging, areas of research in laser-plasma interaction physics. The success of building petawatt femtosecond lasers offers a promising path for designing future particle accelerators and light sources.Achieving this goal intrinsically relies on the combination of experiments and numerical modeling. So far, Particle-In-Cell (PIC) codes have been the ultimate tool to accurately describe the laser-plasma interaction especially in the field of Laser WakeField Acceleration (LWFA). Nevertheless, the numerical modeling of laser-plasma accelerators in 3D can be a very challenging task due to their high computational cost.A useful approach to speed up such simulations consists of employing reduced numerical modes which simplify the problem while retaining a high fidelity.Among these models, Fourier field decomposition in azimuthal modes for the cylindrical geometry is particularly well suited for physical problems with close to cylindrical symmetry, which is the case in LWFA.During my Ph.D., I first implemented this method in the open-source code SMILEI in the Finite Difference Time Domain (FDTD) discretization scheme for the Maxwell solver. However, this kind of solvers may suffer from numerical Cherenkov radiation (NCR). To mitigate this artifact, I also implemented Maxwell’s solver in the Pseudo Spectral Analytical Domain (PSATD) scheme which offers better accuracy of the results.This method is then employed to study the impact of realistic laser profiles from the Apollon facility on the quality of the accelerated electron beam. Its ability to correctly model the involved physical processes is investigated by determining the optimal number of modes and benchmarking its results with full 3D Cartesian simulations. It is shown that the imperfections in the laser pulse lead to differences in the results compared to theoretical profiles. They degrade the performance of laser-plasma accelerators especially in terms of the quantity of injected charge. These simulations, insightful for the future experiments of LWFA that will be held soon with the Apollon laser, put forward the importance of including realistic lasers in the simulation to obtain reliable results

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Gabolde, Pablo. « Measurements of the spatio-temporal profiles of femtosecond laser pulses ». Diss., Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-06272007-101312/.

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Thesis (Ph. D.)--Physics, Georgia Institute of Technology, 2008.
Trebino, Rick, Committee Chair ; Kennedy, Brian, Committee Member ; Kuzmich, Alex, Committee Member ; Curtis, Jennifer, Committee Member ; Buck, John, Committee Member.

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Rønningstad, Oyvind. « Device Profile layer for PDCP ». Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23085.

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The Prosthetic Device Communication Protocol is a CAN-based protocol developed specifically for use within prosthetic devices, for connecting the components of the device, most importantly sensors and actuators. The lower levels of this protocol have already been developed. This thesis focuses on developing a device profile layer, to bring plug-and-play functionality to the protocol.Specifically, this thesis contains a proposed device profile layer, a description of an implementation of the profile layer, and testing of this implementation. Testing results were largely successful, most of the desired functionality was achieved in the implementation.

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Primartomo, A. « Laser surface treatment using customised heat source profiles ». Thesis, Loughborough University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429008.

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Whaley, Chad. « Laser Guided Automated Floor Profiling - FloorWalker ». University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491558782298737.

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Aumeyr, Thomas. « Development of a laser-wire beam profile monitor for PETRA-III and CLIC ». Thesis, Royal Holloway, University of London, 2013. http://repository.royalholloway.ac.uk/items/2b7e6f3c-018c-c906-2534-c5b67f1ad7bf/6/.

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The Compact Linear Collider (CUC) is a proposed electron-positron collider with a centre- of-mass energy of 0.5 to 5 TeV, optimised for a nominal centre-of-mass energy of 3 TeV, at high luminosities exceeding 1034 cm-2s-J. The high beam charges in the CUC beams make classical techniques for measuring the transverse beam size such as optical transition radiation (OTR) screens or wire scanners very difficult, which necessitates the use of non-invasive beam- size monitors. The laser-wire is a system that meets these requirements; it uses inverse Compton scattering to determine transverse beam-sizes by scanning a laser beam across the electron beam. This thesis describes how such a laser-wire system was installed and operated at PETRA-III at DESY, which uses an automated mirror to scan a Q-switched laser pulse across the electron beam and is developed from the system previously operated at PETRA-II. The measurements of key performance parameters are described and used in determining the emittance of the PETRA-III beam. The thesis includes a detailed investigation of the laser .' system as well as the collision measurements. Furthermore, simulations were carried out to design a similar system for the proposed transfer line of the CUC Drive-Beam and the necessary baseline characteristics of such a system are described.

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Smith, Christina Lynn. « Analysis of mixing layer heights inferred from radiosonde, wind profiler, airborne lidar, airborne microwave temperature profiler, and in-situ aircraft data during the Texas 2000 air quality study in Houston, TX ». Texas A&M University, 2003. http://hdl.handle.net/1969.1/2300.

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The mixing layer (ML) heights inferred from radiosondes, wind profilers, airborne lidar, airborne microwave temperature profiler (MTP), and in-situ aircraft data were compared during the Texas 2000 Air Quality Study in the Houston area. The comparisons and resulting good agreement between the separate instruments allowed for the spatial and temporal evolution of the ML height distribution to be determined across the Houston area on September 1, 2000. A benchmark method was created for determining ML heights from radiosonde data. The ML heights determined using this method were compared to ML heights determined using wind profiler data. The airborne lidar and MTP heights were also compared to the wind profiler heights. This was the first time the MTP was used for estimating ML heights. Because of this, the MTP heights were also compared to the ML heights determined by in-situ aircraft data. There was good agreement between the ML estimates when the instruments were co-located. The comparisons between the benchmark method and the wind profilers were independent of the quality of the profiler heights. The statistics for lidar and the wind profilers were better for the inland profiler comparisons. Even so, the results for coastal profilers were similar to the other comparisons. The results between the MTP and the wind profilers were comparable with the results found between the other instruments, and better, in that the statistics were similar for the both the inland and coastal profilers. The results between the MTP and in-situ aircraft data provided additional support for the use of MTP for determining ML heights. The combination of the inland and coastal wind profilers with the airborne instruments provided adequate information for the spatial and temporal evolution of the ML height to be determined across the Houston area on September 1, 2000. By analyzing the ML height distribution, major features were evident. These features included the shallow ML heights associated with the marine air from Galveston Bay and the Gulf of Mexico, and the sharp gradient of increasing ML heights north of Houston associated with the variation in the inversion depth found on this day.

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Wellburn, Daniel. « Circular laser beam intensity profile shaping for uniform surface treatments ». Thesis, University of Liverpool, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533912.

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Francis, R. « Light profile imaging for the evaluation of laser weld quality ». Thesis, Swansea University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637003.

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The weld inspection system developed in this work is based on the principle of optical profiling. Optical profiling is a method for visualising the surface profile of an object while it is being viewed by an imaging source which is perpendicular to its surface. The signal to be viewed by the imaging source is provided by a line of laser light. The laser light is angled relative to the weld surface it is incident upon. The distortion in the laser line gives an indication of weld surface quality. A traditional imaging source for such systems has been the CCD camera. This has been replaced with a novel CMOS camera. The two main benefits a CMOS camera has over standard CCD cameras are (1) Random Pixel Access (2) Logarithmic Response to Light. Taking advantage of the random pixel access capabilities of the CMOS camera procedures were developed to extract the information relevant to weld analysis from minimal sections of the full 2-D image. Using the grey scale signals (logarithmic scale) from just a few single rows or lines within the 2-D image of the projected laser line, it was possible to (a) determine weld edges using wavelet analysis (b) achieve weld surface classification using multivariate analysis. These procedures have been implemented in laboratory set ups, but were also tested successfully online during laser welding.

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Bourne, Carlton M. « Laser reflectance as a function of rough water glitter profile ». Thesis, Monterey, California : U.S. Naval Postgraduate School, 1987. http://hdl.handle.net/10945/22331.

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A new remote sensing technique was developed for predicting the expected mean laser radar return from a rough water surface. This technique involved measuring the standard deviations of the upwind and crosswind profiles of the elliptical glitter patterns occurring for illumination of the water surface with a point source near thelaser radar system. A pencil beam laser radar from a companion project simulataneously measured the reflected signals from the water surface. The glitter pattern images were recorded with a video camera and recorder. The images for each run were later digitized along theri major and minor elliptic asxed and averaged over 256 images to produced smooth intensity curvers from which the standard deviations were measured. The radar returen fluctuated over a large range becasue of the rapid variation of individual water surface facets, and so was recorded and time averaged voer the sam interval as the video images. Data sufficient for empirical preduciton of expected mean laser return signal were obtained. This is necessary to permit evaluation of the performance of a given laser radar design. The data obtained als approximated the predictions of a new model proposed in this work

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Drummond, Fiona Jean. « Spectral interpretation of the melting layer using a wind profiler ». Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55490.

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A boundary-layer wind profiler has been operated continuously in downtown Montreal as a collaborative project of McGill University and the NOAA Aeronomy Laboratory. The records contain hundreds of hours of data on the melting layer of snow, consisting of Doppler spectra in the vertical profiler beam with a typical height resolution of 100 m and a time resolution of about 1 minute. A particular case study day was selected for analysis of precipitation processes associated with the melting of snow to become rain. We have examined the Doppler spectra just above and below the melting layer for evidence of aggregation or breakup during melting. Apart from the complete spectrum, we also show that the product of the mean Doppler velocity and the reflectivity factor in snow should be equal to that in the rain if aggregation and breakup are negligible. Both approaches indicate that there are times when snow merely melts to become rain, each snowflake forming one drop, but other times when aggregation or breakup are evidently important. It appears breakup is associated with regions of higher reflectivity.

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Straka, Michal. « Pájení laserovou diodou ». Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219491.

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This work deals with the laser diode soldering. The theoretical part summarizes general and acquired findings about soldering technology and materials that occur in this process. It also describes factors that affect the reliability of solder joints. It is closely focused to the shaping of the solder joint and structure of intermetallic layer. The practical part of this work is focused on the design of equipment for laser diode soldering and subsequent shaping of the samples. The quality of soldered joint is compared against the quality of joint created using re-flow technology - remelting in in-line smelter. The structure and thickness of the intermetallic layer, the number and shape of the voids in the solder joints are compared.

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Santoso, Edi. « Surface fluxes and vertical profiles in the radix layer ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0028/NQ38975.pdf.

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Xu, Jingping. « Suspended sediment concentration profiles in the bottom boundary layer ». W&M ScholarWorks, 1993. https://scholarworks.wm.edu/etd/1539616914.

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Near-bottom suspended sediment concentrations and velocities were measured on the inner shelf off Duck, N.C. from late October to early November, 1991. This period embraced both fair and storm conditions. Four bottom roughness models are tested using field data together with a wave-current boundary layer model. Bottom roughness plays a significant role in calculations of sediment concentration profiles and current velocity profiles. The importance of each of the three parts in the roughness models (grain roughness, ripple roughness, and sediment motion roughness) vary depending on forcing conditions. A new bottom roughness model is established and tested. The calculated concentration and velocity profiles using the new roughness model compare well to the measured concentration and velocity profiles. The effects of stratification and sediment composition on vertical profiles of current velocity and mean sediment concentration were also investigated. Stratification and sediment composition can have opposing effects. Since natural sediments always consists of multiple grain size components, the equivalent settling velocity is not a constant in the water column. The effects of multiple grain sizes on sediment concentration are more important in fair weather than in storms. Conversely, stratification is most effective during storms. Stratification damps the vertical turbulent transport of mass and momentum (reduces the turbulent eddy viscosity) and causes an increased shear in the current velocity profile. The limit above which stratification must be considered is represented by the stratification stability parameter (z/L = 0.03, where L is the Monin-Obukhov length). The resuspension coefficient &\gamma\sb0& was calculated from these data using a wave-current boundary layer model in association with two roughness models. The relation between &\gamma\sb0& and excess shear stress reported by Drake and Cacchione (1989), Vincent et al (1991) (i.e. resuspension coefficient decreases when excess shear stress increases) was reproduced from using both the Grant and Madsen (1982) and the new roughness models. The decrease of &\gamma\sb0& with increasing excess shear stress in that relation appears to be partially caused by the over-estimate of the sediment motion (movable bed) roughness and under-estimate of the resuspension coefficient when using the Grant and Madsen (1982) roughness model. The neglect of stratification and multiple grain size effects in the calculation of &\gamma\sb0& may also be responsible for the decline in resuspension coefficient with increasing excess shear stress. When the fraction of silt and clay is used in calculating the &\gamma\sb0& values, the &\gamma\sb0& values show no trend of being a function of the shear stress.

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Pottin, Bruno. « Etude d'un profileur optique de faisceaux intenses de protons par absorption laser ». Phd thesis, Université Paris Sud - Paris XI, 2001. http://tel.archives-ouvertes.fr/tel-00001420.

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Prescott, Thomas. « Flux and profile measurements of an atomic beam using laser cooled atoms ». Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/56697.

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The population dynamics of a Magneto-Optical Trap (MOT) make it a potential candidate for flux measurements of an atomic beam. This is achieved by determining the collisional cross section of the trapped atom and the beam particle which would result in ejection of a trapped atom. Due to the properties of a MOT it is possible to make spatial and time-of-flight profiles of the beam using this technique. The work of this thesis explores the collisional cross sections and flux profiles of several gaseous beams with a MOT of ⁸⁵Rb or ⁸⁷Rb. Each of the beams, generated through supersonic expansion, produced a loss cross section on the order of the combined van-der-Waals radii of the two particles. The flux and time-of-flight information of the beam was verified with a Residual Gas Analyser (RGA) and high beam rep rate pressure measurements. The MOT was characterized through a combination of fluorescence detection for population and a catalysis process for the trap's depth. A custom built translation mechanism for the MOT's optics and Helmholtz coils was constructed to perform the profiling measurements.
Science, Faculty of
Physics and Astronomy, Department of
Graduate

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Swales, Christopher. « Advance LDA techniques for measurement of 3D boundary layer velocity profiles on a helicopter rotor ». Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327721.

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Veitel, Hansjörg. « Vertical profiles of NO2 and HONO in the boundary layer ». [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964946211.

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Wang, Hongzhi. « Development of laser system to measure pavement rutting ». [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001371.

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Yip, Wing Lam. « Resonance-enhanced laser-induced breakdown spectroscopy : how the beam profile of the ablation laser and the interception geometry and energy of the reheating laser affect analytical performance ». HKBU Institutional Repository, 2009. http://repository.hkbu.edu.hk/etd_ra/1083.

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Lee, David Alexander. « A Laser-Based Beam Profile Monitor for the RAL Front End Test Stand ». Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520964.

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Deacon, Lawrence. « A micron-scale laser-based beam profile monitor for the international linear collider ». Thesis, Royal Holloway, University of London, 2009. http://repository.royalholloway.ac.uk/items/a6163010-d859-63a9-7a72-189ddc8c3a34/9/.

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A micron-scale laser-wire system was constructed and tested at the Accelerator Test Facility (ATF) extraction line at the High Energy Accelerator Research Organisation (KEK) in Japan. The system was evaluated through collision tests, electron beam tests, laser beam measurements and simulations. Beam halo measurements were carried out in order to compare the beam halo to a theory of its production through gas scattering and towards evaluating it as a source of background for diagnostic instruments at ATF2 and the International Linear Collider (ILC). Simulations were carried out to test the signal extraction of the system at the future ATF2 and of a similar system in the proposed ILC beam delivery system, with implications for sharing the signal extraction region with the polarimeter.

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Kemalli, Onur. « Measurements Of Velocity Profiles By Using Particle Image Velocimeter ». Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611068/index.pdf.

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Particle Image Velocimetry (PIV) is an optical technique used to display and evaluate the motion of fine particles in a flow. In this experimental study, velocity profiles are examined by PIV system and basic analysis methods are compared.

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Brooks, Donald Ray. « Development of Specialized Laser Doppler Velocimeters for High Resolution Flow Profile and Turbulence Spectral Measurements ». Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/78089.

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Fluid dynamicists are always in need of innovative instruments for flow velocity measurements. An ideal instrument would be non-intrusive, have a very fine spatial resolution as well as a very fine temporal resolution, be able to measure three-components of velocity, and be compact. Through recent advancements, laser Doppler velocimetry can now meet all of those requirements making it an important part of aerodynamicist's research toolbox. The first paper presented in this manuscript style thesis explains the development of an advanced three-velocity component, spatially-resolving laser-Doppler velocimetry (LDV) system for highly resolved velocity measurements in situations with limited optical access. The new instrument, a next generation version of the previously developed 'comprehensive' LDV technology, enables measurements of three components of velocity and particle position in the axial direction all through a single transceiving lens. Described here is the design process and the final design for the 'compact, comprehensive' LDV (Comp²LDV). The probe was designed to achieve ± 10 micron root-mean-square uncertainties in axial particle position, which combined with the long measurement volume, allow researchers to obtain a three-velocity-component velocity statistics profiles over a span of approximately 1.5mm without the need for traversing. Results from measurements in a flat plate turbulent boundary layer very near the wall have compared favorably to data from previous studies. The second paper focuses on the motion and evolution of coherent structures in supersonic jet flows and how that relates to the intense noise the flows generate. As a preliminary study to experimentally address these relationships, novel non-intrusive measurements using two-component laser Doppler velocimetry (LDV) have been conducted at exceptionally high data rates to lend insight into the statistical behavior of noise-generating flow structures. A new heated supersonic jet facility has been constructed to provide supersonic flow at total temperatures ratios (T₀/Tₐ) up to 3. In the present work, the instrumentation is validated via comparison of LDV measurements along the centerline of a screeching cold jet with microphone and high-speed shadowgraph results. Reynolds stress spectra are presented for an over-expanded case (nozzle pressure ratio of 3.2) of a design Mach number 1.65 nozzle operated cold (T₀/Tₐ = 1). A preliminary study was then conducted in the near-nozzle shear layer, up to x/d = 4.0, at design nozzle pressure ratio (4.58) and total temperature ratio of 2.0. Results are presented for Reynolds stress time-delay correlations and power spectra at Re_d = 1.1M for this case. The stream-wise Reynolds normal stress spectra are compared with published spectral behavior reported by other researchers, indicating a similar spectral shape in the downstream stations as previously measured with LDV and hot wire anemometry for cold jets, but which differ in shape from density-based techniques.
Master of Science

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Gunal, Murat. « Modification of the Naval Postgraduate School Lidar System ». Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA304245.

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Johansson, Peter. « Water absorption in two-layer masonry systems : properties, profiles and predictions / ». Lund : Lund University, 2005. http://theses.lub.lu.se/scripta-archive/2005/11/15/tec_981/Doctoral_Thesis_TVBM-1024.pdf.

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Arnqvist, Johan. « Mean wind and turbulence conditions over forests ». Licentiate thesis, Uppsala universitet, Institutionen för geovetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-219230.

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Lundberg, Axel. « Temperature profiles and hardness estimation of laser welded heat affected zone in low carbon steel ». Thesis, Malmö högskola, Fakulteten för teknik och samhälle (TS), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-20830.

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Termisk modellring av hårdhet genom beräkning och simulering av den värmepåverkade zonen i en lasersvetsad stålplatta är en omfattande process. Dock är analysen viktig då mikrostrukturella fastransformationer förorsakade av svetsningen kan ge oönskade hårdhetsnivåer av den värmepåverkade zonen jämfört med hårdeheten i basmaterialet. I denna avhandling har analytiska ekvationer implementerats och testats för validitet mot simuleringar gjorda av andra författare och mot experimentella värden.Eftersom termisk modellering av svetsar är ett omfattande område var avhandlingen tvungen att smalnas av för att göra analysen mer fokuserad. Begränsningar gjordes för den matematiska modelleringen genom att endast titta på två-dimensionellt värmeflöde i svetsade plattor där endast den analytiska lösningen är av intresse. Arbetet har också inriktats mot stål då detta material är vida använt över hela världen. Då lasersvetsning är en snabb och kostnadseffektiv process så är hårdhetsanalysen av största vikt. Avhandlingen är uppdelad i tre övergripande delar; den första är att ta fram och förstå arbetet som gjorts inom termisk modellering av svetsar, alltså förstå matematiken bakom problemet. Modelleringen är till för att producera diagram parametrar från en termisk cykel, för att kunna fortgå med korrekt hårdhets analys. För det andra så sätts den matematiska modelleringen på prov i ett antal situationer som var och en simulerar olika förutsättningar. Detta gjordes i ett grafiskt användargränssnitt av ren bekvämlighet. Detta gör att ingenjörer lätt kan implementera olika egenskaper för materialet och få fram diagram och kurvor.Sist, ett liknande grafisk användargränssnitt för att simulera hårdheten i valfri punkt i den värmepåverkade zonen programmerades och därigenom implementerades ekvationerna som denna avhandling handlar om i grund och botten. En teoretisk bakgrund till fasomvandlingen är också inkluderad som förklaring till grundproblemet med oönskad hårdhet i den värmepåverkade zonen i lasersvetsat stål.Huvudslutsatser i avhandlingen:•Matematisk modellering av värmeöverföring i svetsar genomförd av Rosenthal är fortfarande applicerbar på modern lasersvetsningsapparatur. •Den empiriska modellen från Ion et al. (1984) är ej applicerbar med godkänt resultat för hårdhetsuppskattning.•Ekvationerna från Ion (2005) är statistiskt godkända för att simulera hårdhet.•Den analytiska lösningen är överlägsen den numeriska när det gäller snabb och enkel implementering för att simulera termiska cykler och hårdhet, medan den numeriska lösningen kan ta i beaktning mera avancerade egenskaper.•Förvärming av stålet innan svetsning kan vara mycket fördelaktigt för hårdheten i den värme-påverkade zonen, speciellt vid högre kolekvivalent.
Thermal modelling of hardness in the heat-affected zone (HAZ) in a laser welded steel plate is a cumbersome process both in calculation and simulation. The analysis is however important as the microstructural phase transformations induced by welding may cause unwanted hardness levels in the HAZ compared with that of the parent material. In this thesis analytical equations have been implemented and checked for validity against simulations made by other authors and against experimental values.With such a large field as thermal modelling, the thesis had to be narrowed down to make the analysis more subject focused. Limitations made were for mathematical modelling only looking at a two-dimensional heat flow in welded plates; in this thesis only the analytical solution to the heat flow is considered. The work was also directed towards steel; such a material as used largely all over the globe. As laser welding is a fast and cost-effective process, an analysis of hardness is of great importance. Work was divided into three overlapping parts; the first was to derive and understand the work done in the field of thermal modelling of welds, thus understanding the mathematics behind the basic problem. This modelling provides a number of curves and parameters from a thermal cycle, thus enabling one to do the hardness analysis correctly. Secondly, this mathematical modelling was applied to a number of cases, simulating different circumstances. This was done using self-programmed Graphical User Interfaces (GUI) for convenience. This enables engineers to easily plug in the materials and processing properties and thus simulate the required parameters and curves for further analysis.Lastly, a GUI for simulating the hardness of any point in the HAZ was programmed and used, thus implementing and validating the equations. A theoretical introduction of the phases induced in the HAZ is also included, in order of understanding the problems of unwanted hardness in the HAZ of laser-welded steel.Main conclusions of this thesis:•Mathematical modelling of heat transfer in welds by Rosenthal (1946) is still applicable for modern laser welding apparatus.•The empirical model presented by Ion et al. (1984) is not applicable with experimental results of hardness in the HAZ of the steels investigated here.•Equations by Ion (2005) are accurate for simulating the hardness.•The analytical solutions investigated are superior to numerical solutions with regard to quick, simple simulations of thermal cycles and hardness. Numerical solutions allows for more advanced modelling, which can be lengthy.•Preheating the steel prior to welding is favourable in reducing hardness levels, especially with steel of higher carbon equivalent.

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Leimkuehler, Thomas O. « Investigation of low-pressure laser induced fluorescence for measuring temperature profiles in a rarefied gas / ». free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9999301.

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Oh, Seong Yong. « Laser induced breakdown spectroscopy investigation of line profiles, slurries and artifical [sic] neural network prediction / ». Diss., Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-11062007-190817.

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Veitel, Hansjörg. « Vertical Profiles of NO 2 and HONO in the Planetary Boundary Layer ». [S.l. : s.n.], 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10047881.

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Johansson, Niclas, et Magnus Selegran. « Utformande av Sapa Profiler AB:s distributionsstruktur med syfte att uppfylla kundernas krav ». Thesis, Linköping University, Department of Management and Economics, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6183.

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Sapa Profiler AB är ett företag inom den svenska metallindustrin och tillhör koncernen Sapa Group som finns över stora delar av världen. Bolaget är en del av koncernens kärnverksamhet Profiler som specialiserat sig på framställning av strängpressade profiler i aluminium.

Inom det strategiska affärssegmentet Automotive förses transportindustrin med komponenter till olika typer av fordon. Under de senaste åren har kundernas serviceanspråk ökat vilket bland annat yttrar sig i krav på kortare leveranstider och högre frekvens på inleveranserna. I dagsläget avhjälps högre servicekrav genom att ett lager lokaliseras i kundens närhet. Strategin leder i förlängningen till en decentraliserad lagerstruktur som kan vara svår att styra och kontrollera. Sapa Profiler AB behöver därför se över sitt sätt att distribuera varor till de europeiska kunderna. Studien tar sin utgångspunkt i en kartläggning av de 20 viktigaste kundernas krav och har som mål att rekommendera en framtida distributionsstruktur som kan bemöta den nya kravbilden till en låg totalkostnad.

Den rekommenderade lösningen utnyttjar två centrala lagerpunkter placerade i Nässjö och belgiska Ghlin som tillsammans tillgodoser huvuddelen av de nord- och centraleuropeiska kunderna. Dessutom används fem lokala lagerpunkter som är nödvändiga för att täcka in vissa kunders särskilt höga krav. Jämfört med en decentraliserad struktur kan företaget utnyttja stordriftsfördelar som ger betydande besparingar inom lagerhållning, administration, kommunikation och IT. Transportkostnaderna kan samtidigt hållas på en rimlig nivå.

Båda centrallagren är strategiskt placerade och ger företaget goda förutsättningar att knyta andra kunder till distributionsstrukturen. Lösningen är också kompatibel med företagets strategiska mål och kan anpassas till hur kundernas kravbild utvecklas i realiteten. Den ger företaget bättre möjligheter att utveckla serviceerbjudandet till kund för en ökad framtida konkurrensförmåga.

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Raine, Kenneth William. « Advances in the measurement of optical fibre refractive index and axial-stress profiles ». Thesis, King's College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300025.

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Lewandowski, George. « Engineering of Temperature Profiles for Location-Specific Control of Material Micro-Structure in Laser Powder Bed Fusion Additive Manufacturing ». University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1588940683690978.

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Kötter, Hanno. « Ein Beitrag zum Schrägschneiden von Leichtbauprofilen ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-63619.

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Gegenstand der Dissertationsschrift ist eine Darstellung des gegebenen Wissensstandes zum Scherschneiden anhand der Literatur, mit einer Einordnung des Schrägschneidens. Auf dieser Grundlage erfolgt eine Verfahrens- und Prozeßbeschreibung des Schrägschneidens, als Variante des Scherschneidens, insbesondere eine Untersuchung des auftretenden Verschleisses. Es wird die Anwendung des Laser-Pulver-Auftragschweißen an Schneidwerkzeugen zur Verschleißminimierung erprobt und bewertet.

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Sinha, Roy Arijit. « Analysis and control of boundary layer transition on a NACA 0008 wing profile ». Thesis, KTH, Mekanik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-239931.

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The main aim of this thesis was to understand the mechanism behind the classical transition scenario inside the boundary layer over an airfoil and eventually attempting to control this transition utilizing passive devices for transition delay. The initial objective of analyzing the transition phenomenon based on TS wave disturbance growth was conducted at 90 Hz using LDV and CTA measurement techniques at two different angles of attack. This was combined with the studies performed on two other frequencies of 100 and 110 Hz, in order to witness its impact on the neutral stability curve behavior. The challenges faced in the next phase of the thesis while trying to control the transition location, was to understand and encompass the effect of adverse pressure gradient before setting up the passive control devices, which in this case was miniature vortex generators. Consequently, several attempts were made to optimize the parameters of the miniature vortex generators depending upon the streak strength and stability. Finally, for 90 Hz a configuration of miniature vortex generators have been found to successfully stabilize the TS wave disturbances below a certain forcing amplitude, which also led to transition delay.

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Caplinger, James E. « ULTRAVIOLET RAYLEIGH SCATTER IMAGING FOR SPATIAL TEMPERATURE PROFILES IN ATMOSPHERIC MICRODISCHARGES ». Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401750986.

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Winslow, James F. « Investigation of spatial filtering for planar range-resolved pulsed laser ablated plume imaging ». [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000370.

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Thesis (M.S.)--University of South Florida, 2004. Thesis (M.S.E.S.)--University of South Florida, 2004.
Title from PDF of title page. Document formatted into pages; contains 104 pages. Includes bibliographical references.

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Schneider, Matthieu. « Perçage profond par laser : Analyse des processus physiques ». Phd thesis, Université Pierre et Marie Curie - Paris VI, 2006. http://tel.archives-ouvertes.fr/tel-00271589.

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Ce travail de thèse traite le perçage par laser en régime de percussion. Les principaux objectifs étaient de :
• Comprendre les phénomènes physiques intervenant au cours du perçage,
• Déterminer le profil des perçages à partir des paramètres expérimentaux.

La première étape a consisté en l'identification et le contrôle des paramètres opératoires du procédé. A cet égard, ces travaux ont permis de mettre en place des méthodes de caractérisation de la source laser et de son environnement. La limitation de certains diagnostics d'observation a entraîné le développement d'une nouvelle méthode d'analyse de la morphologie des perçages, appelée méthode DODO (Direct Observation of Drilled hOle).
Les études spécifiques concernant la physique du procédé, ont apporté des réponses originales et interprétables sur les mécanismes intervenant au cours du perçage par laser. Ces études traitent de l'absorption et de la transmission du rayonnement au cours du perçage, des divers effets hydrodynamiques engendrés et de l'évolution des profils résultants.
L'absorption au cours du procédé de perçage tend vers une valeur unique (80%) en fonction de la puissance crête incidente quelle que soit la nature du matériau cible. La décroissance de la transmission en fonction de l'épaisseur est due à l'absorption des parois du perçage. La détente de la vapeur métallique consécutive à l'irradiation est supersonique. Deux types de profils existent (U et V) et permettent de remonter sans ambiguïté aux paramètres lasers utilisés lors du perçage. Enfin, l'utilité du gaz d'assistance au cours du perçage est remise en cause. Il est démontré que celui-ci ne peut pénétrer dans le perçage au cours du procédé.
Ces résultats remettent en cause un ensemble de connaissances héritées de la découpe par laser. Ils constituent une solide base de données sur le sujet pour améliorer la maîtrise du procédé et valider de futurs codes de calcul.

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Kohút, Jiří. « Srovnání pulsujícího proudění newtonské a ne-newtonské kapaliny v komplexní geometrii ». Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-416445.

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This master's thesis deals with pulsating flow of Newtonian and non-Newtonian fluid. Theoretical part represents necessary theoretical knowledge for pulsating flow and understanding of non-Newtonian behaviour. Furthermore the thesis focus is directed on numerical simulation of pulsating flow in straight, ideally rigid tube and in patient-specific model of human artery, more precisely in carotid. Two methods are used: numerical solution based on finite volume method (FVM) and also analytical solution using Bessel functions by Womersley. Results are validated against experimental measurements of velocity profiles by particle image velocity method (PIV). The agreement between numerical and experimental data with consideration of PIV inaccuracy was was very good from both point of views - qualitative and quantitative. Numerical solution also compare influence of turbulence and non-Newtonian behaviour towards base (laminar flow, Newtonian fluid). Developed methodology is then applied on patient-specific model of carotid, which was renovated from computed tomography. Measurements in vivo in human arteries is very expensive and often invasive. Because of that measurement outputs are limited, most of the time on pressure and flow. Computational fluid dynamics (CFD) is non-invasive and outputs are through whole domain. Due to these advantages CFD significantly contributes to understanding of hemodynamics influence in cardiovascular diseases.

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Flaud, Pierre-Marie. « Développement et caractérisation d'un spectromètre laser infrarouge par différence de fréquences : application à la spectroscopie infrarouge à très haute résolution ». Paris 11, 2005. http://www.theses.fr/2005PA112285.

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Les méthodes de détection et de caractérisation d'espèces moléculaires d'intérêt atmosphérique dans l'infrarouge se tournent de plus en plus vers l'utilisation de sources laser, monomodes, cw et accordables, complétant des outils tels que les spectromètres à transformée de Fourier (résolution spectrale limitée, source d'erreurs pour la détermination de paramètres moléculaires). Le spectromètre laser infrarouge à différence de fréquence que nous avons développé fonctionne au moyen de deux sources lasers solide (un Nd :YAG, 800 mW à 1064 nm, et une diode-laser à cavité externe, 10-50 mW à 805-885 nm) opérant dans l'infrarouge proche, focalisées au sein d'un cristal non-linéaire de LiNbO3 (PPLN). Il en résulte l'émission d'un faisceau laser à la fréquence égale à la différence des fréquences des faisceaux incidents. Celui-ci possède une largeur spectrale de 3×10-5 cm-1, est accordable de 1800 à 3100 cm-1 sur de petits intervalles spectraux de 0. 5 à 1. 0 cm-1 avec une puissance de quelques 0. 1 microW et un rapport signal/bruit allant jusqu'à quelques milliers, permettant d'enregistrer rapidement (dans une minute environ) les profils et intensités de raies d'absorption avec grande précision. De plus, cet instrument est très compact (0. 7×0. 7 m2). Nous présentons l'instrument et sa caractérisation avec des raies de N2O, la détermination des intensités absolues de NO2 dans l'infrarouge (par intercalibration avec l'UV-visible) montrant des différences systématiques de 5 % par rapport à la base de données HITRAN 2004, ainsi que la première observation d'interférences collisionnelles dans la structure hyperfine de HI (un effet prédit il y a plus de 20 ans)
For laboratory studies and field measurements of atmospheric molecules, single-mode tuneable lasers are more and more used, in order to complete other instruments such as Fourier-transform spectrometers because of their limitations (in particular spectral resolution and signal-to-noise ratio that have an important impact on the accurate determination of molecular line parameters). We report here the development and characterization of a compact tuneable continuous-wave infrared laser, based on difference-frequency generation (DFG) using quasi phase-matching in periodically poled LiNbO3 (PPLN). Several 0. 1 microW of infrared radiation (tuneable in the 1800 à 3100 cm-1 range) are obtained using a diode-pumped Nd:YAG laser (output power about 800 mW at 1064 nm, linewidth 1 kHz) together with a tuneable external-cavity diode laser (output power about 10-50 mW in the 805-885 nm region, linewidth 1 MHz). Using this infrared DFG laser for absorption experiments of gas-phase molecules, both very high resolution (1 MHz) and a high signal-to-noise ratio (up to several 1000) can be achieved in measurement time of only a few minutes, as demonstrated using absorption spectra of N2O in different wavelength regions. Using this laser we have determined absolute intensities of infrared lines of NO2 (using a UV-visible set-up to measure the NO2 amounts) observing a systematic difference of about 5 % with respect to the HITRAN 2004 database. We have used the same laser for the first observation of collisional line-mixing between nuclear hyperfine components of HI lines (a phenomenon predicted over 20 years ago)

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Moses, Lance. « Fluorescence Imaging of Analyte Profiles in an Inductively Coupled Plasma with Laser Ablation as a Sample Introduction Source ». BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/4367.

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Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has risen to among the top tier techniques for the direct analysis of solid samples. However, significant problems remain that must be solved to achieve the full analytical potential of LA-ICP-MS. Inefficient conversion of aerosol to ions within the ICP or transmission through the MS interface may decrease precision, sensitivity, and/or accuracy. Although fundamental mechanisms that govern ion production and transmission have been studied extensively in solution-nebulization (SN) ICP-MS instruments, significant gaps in our understanding remain. Furthermore, it is unclear to what extent differences between the aerosols generated during SN and LA influence either ion production or transmission. In this work, I initially investigated differences in the spatial distributions of Ca, Ba, and Sc ions generated by LA and SN using high-resolution LIF imaging. Ions formed from aerosol generated by LA at low fluence were distributed over much greater axial and narrower radial distances than SN aerosol. Additionally, I investigated the effects of solvent, laser fluence, and ablation atmosphere (He vs Ar) on ion distributions in the ICP. Unlike solvent, changing laser fluence and ablation atmosphere produced considerable changes in the ion signal intensity and spatial distribution during LA. At greater laser fluence, the radial distance over which ions were distributed dramatically increased. Surprisingly, when helium was mixed with argon as carrier gas, ion signals decreased. Many of these effects were assumed to be related to changes in the number and size of particles generated during LA. In a follow-up study, relative contributions to ion densities in the ICP from particles of different sizes were investigated. LIF images were recorded while filtering particles above a threshold size on-line. Micron-sized particles contributed the majority of ions formed in the ICP. For Ba, Ca, and Sc, differences in the axial position where nanometer- and micron-sized particles vaporized were 2, 1, and less than 1 mm, respectively. I also performed experiments to identify changes in the ion signal related to changing ablation conditions vs. changing ICP conditions associated with helium additions to the carrier gas. LIF images were recorded during different combinations of He/Ar added upstream and/or downstream of the ablation cell. Changes in the ion signal during ablation in helium vs argon did not always match expectations based on changes in particle numbers and sizes measured with SEM. The results force re-examination of some of the fundamental assumptions about the effect of carrier gas composition on the performance of LA-ICP-MS. The research described in this dissertation provides valuable insight into fundamental aspects of key ICP processes related to LA generated aerosol.

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Larsson, Sören. « An industrial robot as carrier of a laser profile scanner : motion control, data capturing and path planning / ». Örebro : Örebro universitet, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-1738.

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Heigoldt, Matthias [Verfasser], et Stefan [Akademischer Betreuer] Karsch. « Temporal dynamics of the longitudinal bunch profile in a laser wakefield accelerator / Matthias Heigoldt ; Betreuer : Stefan Karsch ». München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1136270981/34.

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Shirai, Katsuaki [Verfasser]. « Investigation and Application of Laser Doppler Velocity Profile Sensors toward Measurements of Turbulent Shear Flows / Katsuaki Shirai ». Aachen : Shaker, 2010. http://d-nb.info/1122546777/34.

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