Foundational approaches for realizing practical, non-intrusive measurements using filtered Rayleigh scattering (FRS) are presented and analyzed for the multi-property quantification of internal flow fields. Validation is challenging in applying computational fluid dynamics (CFD) solutions to real-world scenarios, necessitating benchmark measurements with well-defined uncertainties. The ideal instrument for achieving the required measurements should be non-intrusive and require no particulate or gas seeding. One approach that satisfies these requirements is filtered Rayleigh scattering. FRS is a laser-based optical diagnostic technique that allows for the simultaneous, non-intrusive measurement of three-component velocity, static temperature, and static density everywhere within a two-dimensional plane illuminated by laser light without using any form of flow seeding. The major disadvantage of FRS is that it is very susceptible to signal contamination from particles and surfaces illuminated by the probing laser source. The effects of these contamination sources of the FRS signal are quantified as a function of their intensity relative to the Rayleigh scattered light. As the most significant contributor to Rayleigh scattering contamination, methods for reducing geometric or background contributions were investigated. Structured illumination was applied in cross-correlation Doppler global velocimetry to reduce geometric scattering contributions in image acquisition, demonstrating the removal of background scattering biases in an FRS-similar technique. For multi-property measurements, it is shown that with only an order of magnitude estimate of Mie and geometric scattering, a range of wavenumbers termed the rejection region can be pre-defined such that molecular iodine absorbs the contamination. At the same time, Rayleigh scattered light can pass through. Mie and geometric scattering contributions are reduced to negligible levels within the rejection region, allowing for unbiased temperature and density measurement. Additionally, a method for determining only Doppler shift, desirable due to its increased processing speed and spatial resolution, was developed and shown to be robust to at least one order of magnitude greater Mie and geometric scattering than other methods. The biases associated with sampling a statistical average of the flow using time-averaged FRS were also investigated. The result is that measuring flow properties with the "constant in time" assumption is valid up to a turbulent intensity of 20%, resulting in biases in velocity and temperature greater than 10% of the measurement uncertainties predicted without these contributions. These advancements allow researchers to optimize measurement parameters and predict uncertainties before integrating them into a facility. These methods were implemented in a turbulent, highly distorted internal flow environment with Mie and background scattering present. Measurement uncertainties for vector velocity components, static temperature, and static density are predetermined using a 95% confidence interval on the Monte Carlo simulation results. Derived measurement uncertainties are calculated by propagating the results of the Monte-Carlo simulation. Measurements are compared to reference five-hole probe and particle image velocimetry measurements to assess the validity of the predicted uncertainty bounds. The results from this study show good agreement in the measurement of axial velocity and derived circumferential and radial flow angles when compared to reference measurements. These comparisons typically yield measurements that measure the same value as the five-hole probe data within the pre-defined uncertainty bounds of 9 m/s, 1.0°, and 3.8°, with significant deviations occurring at radii greater than 71% for tangential flow angle and radii greater than 55% for radial flow angle. Compared to facility average measurements, static density and static pressure data collected over the entire plane show RMSD values comparable to predicted measurement uncertainties of 0.043 kg/m^3 and 4.0 kPa, respectively. For the same comparison, temperature measurements show a greater RMSD than the predicted uncertainty of 8.4 K. While additional work remains to identify sources of bias error in some measurements, this work lays the foundation for FRS-based diagnostics to be used as a replacement or supplemental measurement technique in quantifying the state of fluid flow fields. / Doctor of Philosophy / Rayleigh scattering is a process that results from the interaction of light with microscopic particles that, whether we know it or not, we experience every day. When sunlight interacts with air molecules, the light scattered to our eyes is blue. The fact that the sky appears blue indicates a key property of Rayleigh scattering in that it is most efficient for the shortest wavelengths. What isn't apparent is that a whole host of other properties can be extracted from observed scattering by imaging it with a camera and a specialized filter when illuminated by a narrow wavelength laser. The problem is that a few dust particles, small enough to pass through a household air filter, can scatter more light than all the air molecules in a shot glass, with laser light scattering off large surfaces even more intense. The primary focus of this dissertation is to define Foundational approaches for realizing practical, non-intrusive filtered Rayleigh scattering techniques and methods necessary so that the light scattered from air molecules can be measured while avoiding the scattering from particles and surfaces. These approaches enable the measurement of the three-component velocity, temperature, and density of the gas being illuminated without the measurement affecting the flow itself. Because all these properties can be measured simultaneously, Rayleigh scattering provides one of the most comprehensive experimental measurement techniques available to researchers, making it highly desirable in quantifying gaseous flows and validating computational fluid dynamics calculations. Measurements collected with the techniques outlined in this work are validated experimentally using reference measurements in a large-scale internal flow facility, providing the groundwork for future applications of Rayleigh scattering-based diagnostics.

Lo scopo generale della presente tesi è quello di arricchire la letteratura sul benessere finanziario dei giovani adulti adottando metodologie di ricerca e tecniche statistiche mai applicate in questo filone di ricerca. Nello specifico, nel primo capitolo è stata utilizzata la scoping methodology, ovvero una metodologia di sintesi della letteratura, con l’obiettivo di identificare la definizione, le componenti, i predittori e gli outcome del benessere finanziario dei giovani. Nel secondo capitolo è stata applicata la Latent Transition Analysis, con l’obiettivo di identificare sottogruppi omogenei di giovani rispetto ai marcatori dell’adultità che essi hanno già raggiunto e di verificare la relazione di tali sottogruppi con il benessere finanziario dei giovani che ad essi appartengono. Il terzo capitolo propone una metodologia per sviluppare e validare nuovi strumenti di misurazione, sulla base della visione contemporanea della validità. Tale metodologia, composta da tre diversi step, è stata utilizzata per la creazione di uno strumento adatto a misurare, su un campione di giovani italiani, il benessere finanziario soggettivo. Infine, il quarto capitolo riguarda la multiple informant methodology, che è stata utilizzata per raccogliere informazioni da madre, padre e figlio sul processo di socializzazione finanziaria familiare ed il suo impatto sul benessere finanziario del figlio. / The general aim of this research work is to enrich the literature on emerging adults’ financial well-being with research methodologies and statistical techniques never previously applied in this research field. Specifically, the first chapter of this thesis concerns the scoping methodology, a knowledge synthesis methodology that I adopted to identify the emerging adults’ financial well-being definition, components, predictors and outcomes. The second chapter consists in the application of a new statistical technique, Latent Transition Analysis, that I used to identify subgroups of emerging adults homogeneous in their configuration of adult social markers already reached and to investigate the relation between these emerging adults’ subgroups and their financial well-being. The third chapter describes a three-step methodology to develop and validate new measurement instruments, based on the contemporary view of validity proposed in the last fifty years. This three-step procedure was here applied to develop and validate a new instrument measuring subjective financial well-being for an emerging adult target population. Finally, the fourth chapter concerns the multiple informant methodology that I applied to collect information about family financial socialization and its impact on the child’s financial well-being from mother, father and the emerging adult child.

Die verteilte faseroptische Sensorik (VFOS) auf Basis von Rayleighstreuung stellt ein besonderes und vielversprechendes Verfahren zur Dehnungsmessung im Betonbau und im Structural Health Monitoring (SHM) dar. Neben einer hohen Ortsauflösung und Messempfindlichkeit kann sie geringste Dehnungsänderungen an jedem Punkt der Messfaser erfassen. Für einen zuverlässigen Einsatz fehlen aktuell Material- und Handlungsempfehlungen; in der Literatur finden sich widersprüchliche Aussagen zu den Dehnungsübertragungsverlusten zwischen Substrat und Messfaser. Diesbezüglich beschäftigt sich die vorliegende Arbeit mit der Validierung des Messverfahrens für Szenarien im Betonbau. Neben der Applikation auf Stahl- und Betonoberflächen wurde die Integration in der Matrix untersucht. Im Zuge dessen sollten die Dehnungsübertragungsverluste verschiedener Fasercoatings bzw. Fasercoating-Klebstoff-Kombinationen überprüft werden. Darüber hinaus wurde ein Auswerteverfahren mithilfe der Programmiersprache Python entwickelt, das eine automatisierte Datenaufbereitung und Substituierung der Messabweichungen der enormen Datenmengen ermöglicht. Im Zuge der Validierung auf der Stahloberfläche wurden die Dehnungswerte der verschiedenen Coating-Klebstoff-Kombinationen an Präzisionsflachstählen im 4-Punkt-Biegeversuch mit einer photogrammetrischen Dehnungsmessung verglichen. Im Rahmen der Validierung auf der Betonoberfläche kamen Betondruckzylinder zum Einsatz, an denen zusätzlich zu den Coating-Klebstoff-Kombinationen der Einfluss einer Grundierung untersucht wurde. Induktive Wegaufnehmer dienten im Verlauf der Druckversuche als Vergleichsmesstechnik. Die Validierung verschiedener Coatingmaterialien in der Matrix fand anhand von Schwindversuchen an Betonprismen statt; als Vergleichsmessmethode dienten digitale Messuhren. Zur Bewertung der aus den Validierungsversuchen abgeleiteten Material- und Handlungsempfehlungen wurden Bauteilversuche an Betonbalken durchgeführt. Die Auswertung der Validierungsversuche zeigte, dass vor allem mit einem Ormocer-Coating gute Ergebnisse hinsichtlich der Dehnungsübertragung erzielt werden konnten. Im Falle einer Applikation empfiehlt sich die Verwendung eines Cyanacrylatklebstoffs -- besonders der M-Bond 200 überzeugte durch geringe Dehnungsverluste. Betonoberflächen sollten vorher geschliffen und mit Epoxidharz grundiert werden. Im Falle einer Integration in die Betonmatrix zeigten auch die Ormocer-Fasern minimale Unterschiede zur Vergleichsmessung. Die Ergebnisse der Bauteilversuche verifizieren die Handlungs- und Materialempfehlungen: Die Dehnungswerte der Fasern decken sich mit denen der analytischen Bemessung der Betonbalken. Lediglich an den Lasteinleitungsstellen konnten Oszillationen des Dehnungsverlaufs durch Gefügestörungen festgestellt werden. Forschungsbedarf besteht v.a. hinsichtlich der Validierung weiterer Komponenten (Klebstoff, Coating, Grundierungsmittel) und deren Langzeitstabilität, insbesondere bei chemischen und dynamischen Beanspruchungen. Im Rahmen dieser Arbeit konnte ein Überblick über verschiedene Materialien geschaffen werden, jedoch ist das Repertoire an verfügbaren Komponenten immens, gerade bei den Klebstoffen. Bei der Validierung auf der Betonoberfläche und in der Matrix kam eine Feinkornbetonmischung zum Einsatz. Diesbezüglich sollten in weiteren Forschungen unterschiedliche Matrices und Korngrößen Untersuchungsgegenstand sein. / Distributed fiber optic sensor (DFOS) technology based on Rayleigh scattering is a unique and promising method for strain measurement in concrete structures as well as structural health monitoring (SHM). It can detect the smallest strain changes at any point in the measuring fiber with a high spatial resolution and sensitivity. Currently, there exist no material and handling recommendations for a reliable application, and the literature contains contradictory statements on strain transfer losses between substrate and fiber. The present study deals with the validation of this measuring method for scenarios in concrete structures. Besides applications on steel and concrete surfaces, the integration in a concrete matrix was investigated. The validation yields results for strain transfer losses for different fiber coatings or fiber coating/adhesive combinations. Furthermore, the development of an evaluation method using the computer language Python provides automated data preparation and measurement error substitution of the enormous data volumes. For the validation on steel surfaces, the strain values of different coating-adhesive combinations on precision flat steels were compared in a 4-point bending test with a photogrammetric strain measurement. For the validation on concrete surfaces, concrete pressure cylinders were used to investigate the influence of a primer and different coating-adhesive combinations. Inductive displacement transducers served as a comparative measuring technique during the compression tests. Shrinkage tests allowed the validation of different coating materials in a matrix on concrete prisms. Digital dial gauges were used as a comparative measuring method. For evaluation purposes, the material and handling recommendations derived from the validation were tested on concrete beams. The results of the validation tests indicate good results regarding strain transfer with an Ormocer coating. For application as tested , the use of a cyanoacrylate adhesive is recommended -- especially M-Bond 200 was convincing due to its low strain losses. Concrete surfaces should be sanded and primed with epoxy resin. If integrated into a concrete matrix, the Ormocer fibers also showed minor differences from the comparative measurement. The results of the evaluation tests verify the handling and material recommendations: the strain values of the fibers correspond to the values obtained in concrete-beam analysis. Oscillations of the strain profile due to microstructural disturbances could only be detected at the load application points. Further research regarding the validation of additional components (adhesives, coating, primer) and their long-term stability, especially chemical and dynamic loads, is necessary. This study provides an overview of different coating and adhesives. However, the repertoire of available components is immense - especially for adhesives. During the validation on concrete surfaces and in matrix, a fine-grained concrete mixture was used. In this respect, different matrices and grain sizes should be the subject of further research.