Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"optical diagnostic techniques"”.
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Fuel Droplet Optical Diagnostic Techniques for Lean Premixed Prevaporized Aeroengine Combustors
… conditions. This work employs a combination of optical diagnostics to enhance the understanding of fuel spray dynamics. Here, Mie scattering is utilized to visualize and measure the penetration depth of fuel sprays inside the combustor at reacting conditions. Both Jet-A and synthetic aviation …
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A review of optical diagnostic techniques used to identify uranium spectral signatures
… proliferation. Through non-invasive measurement techniques it is possible to remotely monitor an area and confirm or deny the use of nuclear materials in explosives. Given that all elements have a unique atomic and molecular emission signature, explosive compositions can be determined by making …
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An experimental investigation of organized structure and mixing in compressible turbulent free shear layers
… on the nature of the mixing layer. Nonintrusive optical diagnostic techniques were employed to image the large structures. Both Mie scattering from condensed ethanol droplets and laser-induced fluorescence from seeded nitric oxide were used. The LIF experiments were utilized to avoid potential …
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Visualising convective heat transfer in a propagating wildland fire
… burner, a custom-built wind tunnel, and advanced optical diagnostic techniques, including Retroreflective Shadowgraphy (RS) and Background Oriented Schlieren (BOS), to visualise and quantify heat transfer dynamics. Thermocouples, Pitot tubes, and heat flux sensors were used to capture physical …
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Spatially-resolved reflectance spectroscopy with variable fiber geometry
Optical techniques based on spectroscopic analysis have the potential for in vivo detection of early malignancies in tissue. Many optical modalities, including reflectance spectroscopy, use fiber optics as the means of light delivery and detection. However, the influence of fiber geometry on …
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Flame stabilization and mixing characteristics in a stagnation point reverse flow combustor
… pressure SPRF combustor with the help of various optical diagnostic techniques: OH PLIF, chemiluminescence imaging, PIV and Spontaneous Raman Scattering. Results indicate that the combustor is primarily stabilized in a region downstream of the injector that is characterized by low average …
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Novel Low Coherence Interferometric Tools for Early Detection of Cancer
… risk from more advanced disease. Developments in optical diagnostic techniques have shown promise in early detection of colorectal and cervical cancer, potentially able to improve upon existing preventative screening techniques in terms of accuracy and detection time.</p><p>This dissertation is …
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Development Of A Two-Color Optical Diagnostic For The Determination Of Engine In-Cylinder Soot Temperature And Volume Fraction Evolution With A Flame-Calibrated Emissivity Model
… to quantify this parameter in-cylinder. Optical diagnostic techniques such as -- Rayleigh scattering, filtered Raman scattering (Doppler), Raman scattering, coherent anti-stokes Raman spectroscopy (CARS), vibrational thermally-assisted fluorescence, two-line atomic fluorescence, two-line …
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Laser Diagnostics Applied to Lean Premixed Swirling Flames - Simultaneous Flow Field and Scalar Measurements
… premixed swirling flames. Various laser-based optical diagnostic techniques were used to collect information under different operational conditions. Combined flow- and scalar field measurements were performed at high repetition rates for detailed studies of the turbulent flames. A large part of …
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A pair of immiscible ternary liquids with matchable refractive indexes over a wide range of density and viscosity ratios
… fluorescence, and a number of other modern optical diagnostic techniques in two-phase flows is severely limited by the difference in refractive index across a fluid/fluid interface, which leads to optical distortion and significantly complicates data interpretation. This problem can be …
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Swirl-stabilized lean-premixed flame combustion dynamics: An experimental investigation of flame stabilization, flame dynamics and combustion instability control strategies
… of combustion radicals has been a cornerstone diagnostic for the field of combustion for the past two decades which allows for visualization of flame structure and behavior. However, resolving both temporal and spatial structures from image-based experimental data can be very challenging. Thus, …
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Multi-Dimensional Quantitative Laser-based Diagnostics - Development and Practial Applications
Laser based optical diagnostic methods are routinely used in combustion research. Many of the more common approaches are based on illuminating a cross-section of the sample with a thin laser sheet. For example, by targeting an electronic transition in a molecule, its concentration within the plane …
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Modeling of no radiative emission in non-equilibrium hypersonic flow
… flows have to be measured using non-invasive optical diagnostic techniques. The creation of Nitric Oxide in hypersonic shocks can be measured both by radiative emission and absorption measurements. NO is an ideal optical diagnostic tool because it has a significant absorption cross section, …
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The effects of micro-vortex generators on normal shock wave/boundary layer interactions
… shock wave/boundary-layer interaction. These diagnostics measured the time-averaged and instantaneous flow organization in the vicinity of the microramps and SWBLI. The results reveal that a microramp produces a complex vortex structure in its wake with two primary counter-rotating vortices …