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Lee, Christopher Francis. "Use of wind profilers to quantify atmospheric turbulence". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/use-of-wind-profilers-to-quantify-atmospheric-turbulence(d6a12ed2-533a-4dae-9f0d-747bc0b4c725).html.
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Doppler radar wind profilers are already widely used to measure atmospheric winds throughout the free troposphere and stratosphere. Several methods have been developed to quantify atmospheric turbulence with such radars, but to date they have remained largely un-tested; this thesis presents the first comprehensive validation of one such method. Conventional in-situ measurements of turbulence have been concentrated in the surface layer, with some aircraft and balloon platforms measuring at higher altitudes on a case study basis. Radars offer the opportunity to measure turbulence near continuously, and at a range of altitudes, to provide the first long term observations of atmospheric turbulence above the surface layer. Two radars were used in this study, a Mesosphere-Stratosphere-Troposphere (MST) radar, at Capel Dewi, West Wales, and the Facility for Ground Based Atmospheric Measurements (FGAM) mobile boundary layer profiler. In-situ measurements were made using aircraft and tethered-balloon borne turbulence probes. The spectral width method was chosen for detailed testing, which uses the width of a radar's Doppler spectrum as a measure of atmospheric velocity variance. Broader Doppler spectra indicate stronger turbulence. To obtain Gaussian Doppler spectra (a requirement of the spectral width method), combination of between five and seven consecutive spectra was required. Individual MST spectra were particularly non-Gaussian, because of the sparse nature of turbulence at its observation altitudes. The width of Gaussian fits to the Doppler spectrum were compared to those from the `raw' spectrum, to ensure that non-atmospheric signals were not measured. Corrections for non-turbulent broadening, such as beam broadening, and signal processing, were investigated. Shear broadening was found to be small, and the errors in its calculation large, so no corrections for wind shear were applied. Beam broadening was found to be the dominant broadening contribution, and also contributed the largest uncertainty to spectral widths. Corrected spectral widths were found to correlate with aircraft measurements for both radars. Observing spectral widths over time periods of 40 and 60 minutes for the boundary layer profiler and MST radar respectively, gave the best measure of turbulence intensity and variability. Median spectral widths gave the best average over that period, with two-sigma limits (where sigma is the standard deviation of spectral widths) giving the best representation of the variability in turbulence. Turbulent kinetic energies were derived from spectral widths; typical boundary layer values were 0.13 m 2.s (-2) with a two-sigma range of 0.04-0.25 m 2.s (-2), and peaked at 0.21 m 2.s (-2) with a two-sigma range of 0.08-0.61 m 2.s (-2). Turbulent kinetic energy dissipation rates were also calculated from spectral widths, requiring radiosonde measurements of atmospheric stability. Dissipation rates compared well width aircraft measurements, reaching peaks of 1x10 (-3) m 2.s (-3) within 200 m of the ground, and decreasing to 1-2x10 (-5) m 2.s (-3) near the boundary layer capping inversion. Typical boundary layer values were between 1-3x10 (-4) m 2.s (-3). Those values are in close agreement with dissipation rates from previous studies.
2
Adachi, Ahoro. "An observational study of mesoscale phenomena with UHF wind profilers". 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/136957.
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Renggono, Findy. "Study on precipitating clouds over Kototabang, west Sumatra observed by wind profilers". 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/144127.
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Leblanc, Sylvain G. "Studies of turbulence with a wind profiler". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22755.
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In Doppler radar analysis of the atmosphere the spectrum width is rarely used but it contains information about turbulence. Turbulence is not the only effect that contributes to the broadening of the spectrum. Another effect is the cross-beam wind, which can be dominant in broad-beam radars such as wind profilers. Once this effect is removed, the so-called residual width then serves as an indication of turbulence. A large snowstorm is used in this study for the computation of the residual width. Strong wind and wind shear were observed during the storm. The time-height pattern of residual width bears a close resemblance to that of wind shear. This supports the interpretation of the residual width as being an indication of turbulence induced by wind shear. Energy dissipation rates are also estimated for the snowstorm. In some regions values as large as 800 cm$ rm sp2 s sp{-3}$ are observed. These are large, but within the range of what has been reported by others. The same techniques were applied to the study of clear-air turbulence to relate radar reflectivity with turbulence.
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Domps, Baptiste. "Identification et détection de phénomènes transitoires contenus dans des mesures radar à faible rapport signal à bruit : Applications conjointes aux problématiques océanographique et atmosphérique". Electronic Thesis or Diss., Toulon, 2021. http://www.theses.fr/2021TOUL0001.
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L'observation de la dynamique de l'atmosphère et de la surface de l'océan peut être réalisée par télédétection radar. L'approche habituelle consiste, dans les deux cas, à calculer numériquement le spectre Doppler des échos temporels reçus à l'aide d'une transformée de Fourier discrète. Bien que satisfaisante pour la plupart des applications, cette méthode ne convient pas pour l'observation de phénomènes transitoires, plus courts que le temps d'intégration nécessaire à l'observation radar. Nous utilisons une technique alternative, basée sur une représentation autorégressive des séries temporelles radar et associée à la méthode dite à entropie maximale. Cette approche est appliquée à la mesure de courants de surface par radar côtier dans la bande des hautes fréquences, puis à celle de vent dans la basse atmosphère par radar en bande L. Dans les deux situations, nous montrons à l'aide de simulations numériques, de comparaisons avec d'autres instruments et d'études de cas que l'approche proposée conduit à des estimations fiables des grandeurs géophysiques (courants marins et vitesses de vent) pour des temps d'intégration brefs, là où la méthode conventionnelle échoueObservations of atmospheric and ocean surface dynamics can be performed via radar remote sensing. The usual approach consists, in both cases, in numerically calculating the Doppler spectrum of the received temporal echoes using a discrete Fourier transform. Although satisfactory for most applications, this method is not suitable for observations of transient phenomena due to being shorter than the integration time required for radar observations. We use an alternative technique based on an autoregressive representation of the radar time series combined with the maximum entropy method. This approach is applied to coastal radar measurements of surface currents in the high frequency band as well as to L-band radar measurements of wind in the lower atmosphere. For both cases, through numerical simulations and case studies, we compare our approach with others that use different instruments. We show that for short integration times, where conventional methods fail, our proposed approach leads to reliable estimates of geophysical quantities (ocean currents and wind speeds)
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Soler-Bientz, Rolando. "Evaluation of the wind patterns over the Yucatán Peninsula in México". Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/5988.
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Wind power is seen as one of the most effective means available to combat the twin crises of global climate change and energy security. The annual market growth has established wind power as the leading renewable energy technology. Due to the availability of sparsely populated and flat open terrain, the Yucatán Peninsula located in eastern México is a promising region from the perspective of wind energy development but no comprehensive assessment of wind resource has been previously published. A basic requirement when developing wind power projects is to study the main characteristic parameters of wind in relation to its geographical and temporal distribution. The analysis of diurnal and seasonal wind patterns are an important stage in the move towards commercial exploitation of wind power. The research developed during the PhD has comprehensively assessed the wind behaviour over the Yucatán Peninsula region covering long term patterns at three sites, a spatial study using short term data for nine sites, a vertical profile study on one inland site and an offshore study made on a pier at 6.65km from the North shore. Monthly trends, directional behaviours and frequency distributions were identified and discussed. The characteristics of the wind speed variation reflected their proximity to the coast and whether they were influenced by wind coming predominantly from over the land or predominantly from over the sea. The atmospheric stability over the eastern seas was also analysed to assess thermal effects for different wind directions. Diurnal wind speed variations are shown to be affected in particular by the differing wind conditions associated with fetches over two distinct offshore regions. Seasonal behaviour suggests some departure from the oscillations expected from temperature variation. The offshore wind is thermally driven suggesting largely unstable conditions and the potential development of a shallow Stable Internal Boundary Layer.
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Ritlop, Robert. "Toward the aerodynamic shape optimization of wind turbine profiles". Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66672.
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This research presents automatic aerodynamic shape optimization results for the NREL S809 wind turbine profile. The objective of this re-design was to improve the total lift to drag ratio for steady low-Mach number flows. This research sets the groundwork for the development of a multidisciplinary optimization framework for complete wind turbine rotors. To develop the aerodynamic design framework for the wind turbine applications, low-Mach preconditioning and Menter's k-omega SST turbulence model have been implemented into the flow solver. A preconditioned discrete viscous adjoint-based automatic aerodynamic optimization method has been developed and validated. Various design case studies of the NREL Phase VI blade, at different free-stream Mach numbers, have been conducted.Ce projet de recherche présente les résultats d'une méthode d'optimisation automatique de formes aérodynamiques, appliquée aux profils de l'éolienne NREL S809. L'objectif de cette reconception est d'améliorer le rapport portance sur traîné e dans le cas d'écoulements stationnaires à faible nombre de Mach. Ce projet de recherche définit les bases de travail pour le développement de méthodes et d'outils d'optimisation multidisciplinaire de rotors d'éolienne. Dans ce cadre de conception aérodynamique appliquée aux éoliennes, un préconditionneur pour faible nombre de Mach ainsi que le modèle de turbulence k-omega SST de Menter ont été implémentés dans le modèle numérique de simulation de mécanique des fluides. Une méthode adjointe discrète préconditionnée automatique d'optimisation aérodynamique pour les fluides visqueux a été développée et validée. Plusieurs études de cas de conception de la pale NREL Phase VI ont été effectuées pour différents Mach infini-amonts.
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Ignace, Richard, R. Bessey e C. Price. "Modeling Forbidden Line Emission Profiles from Colliding Wind Binaries". Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etsu-works/6266.
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This paper presents calculations for forbidden emission-line profile shapes arising from colliding wind binaries. The main application is for systems involving a Wolf–Rayet (WR) star and an OB star companion. The WR wind is assumed to dominate the forbidden line emission. The colliding wind interaction is treated as an Archimedean spiral with an inner boundary. Under the assumptions of the model, the major findings are as follows. (i) The redistribution of the WR wind as a result of the wind collision is not flux conservative but typically produces an excess of line emission; however, this excess is modest at around the 10 per cent level. (ii) Deviations from a flat-toped profile shape for a spherical wind are greatest for viewing inclinations that are more nearly face-on to the orbital plane. At intermediate viewing inclinations, profiles display only mild deviations from a flat-toped shape. (iii) The profile shape can be used to constrain the colliding wind bow shock opening angle. (iv) Structure in the line profile tends to be suppressed in binaries of shorter periods. (v) Obtaining data for multiple forbidden lines is important since different lines probe different characteristic radial scales. Our models are discussed in relation to Infrared Space Observatory data for WR 147 and γ Vel (WR 11). The lines for WR 147 are probably not accurate enough to draw firm conclusions. For γ Vel, individual line morphologies are broadly reproducible but not simultaneously so for the claimed wind and orbital parameters. Overall, the effort demonstrates how lines that are sensitive to the large-scale wind can help to deduce binary system properties and provide new tests of numerical simulations.
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Stec, Jeffrey D. "Wind profiler study of the central California sea/land breeze /\". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA317994.
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Thesis (M.S. in Meteorology and Physical Oceanography) Naval Postgraduate School, September. 1996.Thesis advisor(s): Carlyle H. Wash. "September 1996." Includes bibliographical references (p. 97-100). Also available online.
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Low, David J. "Studies of the lower atmosphere with a VHF wind profiler /". Title page, abstract and contents only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phl9121.pdf.
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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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Singh, Jaskirat. "Wind Speed Profiles and Pressure Coefficients Obtained in the Wind Induced Damage Simulator for Silsoe Cube Model". Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41094.
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Hazardous winds, such as tornadoes and hurricanes, have a great impact on civil engineering structures and cause significant social and economic disturbances. The wind speed and pressure tested in the conventional wind tunnel experiments are much smaller than the actual wind speed and pressure measured in the field. Therefore, the Wind-induced Damage Simulator (WDS) was constructed at the University of Ottawa to overcome the wind speed limitations of wind tunnels and to simulate different types of wind speed profiles. WDS is an isolated cubic box with dimensions 3.65m x3.65 m and 3.0 m height, with multiple inlets on the side faces of the testing chamber and an outlet on the top side. This unique equipment creates a controlled environment for studying wind speed profiles in a confined space, by regulating the air flow with the aid of an attached industrial blower. To measure the simulated wind velocities inside the WDS and to obtain the wind speed profile in the testing chamber, Aeroprobe (12- Hole Probe) sensor was used for different combinations of opened inlets and at four different locations. The data collected from the Aeroprobe was processed by the use of the Aeroflow 2.7.5.7346 software, to get the velocity of wind in three different directions (u, v and w) and the mean velocity at a single point. After determining the mean velocity at different heights and RPM values at all four positions, Matlab software was used to determine the wind profile and the spectra of the turbulence intensities and these were compared for different heights at the four investigated locations and for various rotations per minute (RPM) values (400 to 800 RPM) for controlling the blower. Once the flow characterization was completed, the wind-induced pressure for three models of the Silsoe Cube were measured as a part of the second phase of the test. The current experiment employed 3 different scales of Silsoe cube: 1:40, 1:30 and 1:20, while the pressure coefficients were determined at 16 different points along a vertical line crossing the faces of the cube. A pressure taps system with 16 channels and a Scanivale pressure scanner were used to measure the pressure at 16 different positions on the cube. Matlab software was used to determine the pressure coefficients from the data measured by pressure taps. The pressure coefficienst for the Silsoe Cube were plotted and compared for the three different scales. Also, for determining the best scale to be used in future experiments. The pressure coefficients of the 3 different scaled model of Silsoe Cubes was compared with full-scale data reported in the literature for the same structure. Based on the results obtained from the experiments, recommendations for the best location in the testing chamber for the future experiments employing the WDS were formulated.
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Konow, Heike [Verfasser], e Felix [Akademischer Betreuer] Ament. "Tall wind profiles in heterogeneous terrain / Heike Konow. Betreuer: Felix Ament". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2015. http://d-nb.info/1068316713/34.
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Sundberg, Johanna, Martina Lundberg, Julia Solhed e Aikaterini Manousidou. "Two-dimensional Study of Blade Profiles for a Savonius Wind Turbine". Thesis, Uppsala universitet, Elektricitetslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-412795.
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A Savonius wind turbine is a self-starting vertical axis rotor. It can be designed to be compact in size and also produces less noise which makes it suitable to integrate into urban spaces such as rooftops and sign-poles. These characteristics make it interesting from a sustainability point of view, especially when aiming to increase the decentralization of electricity production. This thesis aimed to investigate the aerodynamic performance of different two-bladed Savonius profiles by varying the blade arc angle and the overlap ratio. For evaluation, the dimensionless power coefficient and torque coefficient were investigated over different tip speed ratios. The study was conducted numerically with 2D simulations in Ansys Fluent. The partial differential equations describing the characteristics of the flow, including the flow turbulence effects, were solved with the Reynolds-average Navier Stokes in combination with the k-omega SST model. A validation was performed by comparing data from simulated and experimental tests of a semi-circular profile and a Benesh profile. The investigation of the blade arc angle and overlap ratio was performed on a Modified Bach profile. The profile with a blade arc angle of 130 degrees and an overlap ratio of 0.56 generated a maximal power coefficient of 0.267 at a tip speed ratio of 0.9. This blade configuration generated the best performance of all conducted simulations in this project. However, this project contained uncertainties since simulations can never be an exact description of reality. The project was also limited by the computational power available. Nevertheless, according to the conducted simulations, it was observed that a higher blade arc angle and a larger overlap ratio seem to generate higher efficiency.En Savonius vindturbin är en självstartande vertikalaxlad rotor som kan utformas i en kompakt design samtidigt som den producerar mindre oljud än horisontalaxlade vindkraftverk. Dagens hållbarhetssträvan i kombination med Savonius turbinens karakteristiska egenskaper gör den till ett potentiellt starkt vertyg för vindenergi. Då den kan placeras på exempelvis hustak eller skyltstolpar, utan att störa närliggande omgivning, finns det många möjliga sätt att implementera och integrera den i samhällets infrastruktur. Målet med detta projekt var att undersöka den aerodynamiska prestationen för Savoniusturbiner med två blad genom att variera bladvinkeln och överlappningsförhållandet. För att jämföra de olika profilerna användes den dimensionslösa effektkoefficienten och momentkoefficienten. Dessa koefficienter beräknades i förhållande till löptalet. Studien utfördes numeriskt med 2D-simuleringar i Ansys Fluent. De partiella differentialekvationerna som beskriver flödets egenskaper, inkluderat turbulenseffekterna, löstes med Reynolds-average Navier Stokes i kombination med k-ω SST modellen. En validering utfördes genom att jämföra data med simulerade och experimentella värden av en Semi-circular profil och en Benesh profil. Studien av bladvinkel och överlappningsförhållandet utgick från en Modified Bach profil. Den mest effektiva profilen hade en bladvinkel av 130 grader och ett överlappsförhållande på 0,56. Den genererade en maximal effektkoefficient av 0,267 vid löptal 0,9. Projektet innehöll en del osäkerheter då simuleringar aldrig kan beskriva verkligheten till fullo. Den tillgängliga beräkningskapaciteten begränsade även projektet ytterligare. Trots vissa begränsningar, visar ändå utförda simuleringar att ökad bladvinkel och ökat överlappningsförhållande genererar högre effekt.
This project was conducted within Stand up for wind and Stand up for energy.
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Scott, Tyler David. "Analysis of the neutral wind profiles from the HEX II experiment". Connect to this title online, 2009. http://etd.lib.clemson.edu/documents/1252937860/.
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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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Thornhill, Kenneth L. II. "An investigation of the environment surrounding supercell thunderstorms using wind profiler data". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/26958.
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Ahmed, Irfan [Verfasser]. "Development of Form-Adaptive Airfoil Profiles for Wind Turbine Application / Irfan Ahmed". Kassel : Kassel University Press, 2017. http://d-nb.info/1143155335/34.
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Umemoto, Yasuko. "Studies on orographic rainbands based on combined wind profiler-weather radar observations". 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/136773.
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Bocanegra, Salas Erick Brayam. "Implementation of routines for the estimation of winds and precipitation of a wind profiler radar with spaced antenna design that operates in UHF band". Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/656999.
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El Instituto Geofísico del Perú ha desarrollado un proyecto, financiado por INNOVATE Perú, llamado “Diseño e implementación de un radar perfilador de vientos que opera en UHF para estudios de turbulencias y precipitación en el territorio peruano”, este proyecto es la propuesta de solución a una limitación presentada por la comunidad científica del Perú y otras entidades para hacer estudios climáticos de vientos y precipitación. Parte del desarrollo de este radar, es el procesamiento de los datos recibidos. En esta tesis se ha hecho un análisis del diseño, frecuencia y tipo de radar que fue diseñado para luego seleccionar los algoritmos de procesamiento necesarios. Los algoritmos que se desarrollaron para el procesamiento del radar UHF permiten estimar vientos troposféricos y turbulencia con la técnica de análisis espectral total. Además de medir la intensidad de precipitación y el factor de reflectividad obtenido de las lluvias con la relación del diámetro de gotas y el factor de reflectividad. Los resultados de estas estimaciones, posteriormente son comparados con otros instrumentos para su validación y su posterior aplicación.The Geophysical Institute of Peru (IGP) has developed a project called "Design and implementation of a radar profiler that operates in UHF for studies of turbulence and precipitation in the Peruvian territory", this project is the proposed solution to a limitation presented by the scientific community of Peru and other entities to conduct climate studies of winds and precipitation. Part of the development of this radar is the processing of received data. In this thesis an analysis of the design, frequency and type of the designed radar was done to then select the appropriate processing algorithms. The algorithms that were developed for the UHF radar processing allows the estimation of tropospheric winds and turbulence with the full spectral analysis technique. In addition to measuring the intensity of precipitation and the reflectivity factor obtained from rainfall related to the diameter of drops and the reflectivity factor. The results of these estimates are then compared with other instruments for validation and subsequent application.
Tesis
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Dobos, Paul H. "Evaluations of 404 MHz radar wind profiler observations at Okinawa during TCM-90". Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23664.
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Ignace, R., W. Waldron, J. Cassinelli e A. Burke. "X-ray Emission Line Profiles from Wind Clump Bow Shocks in Massive Stars". Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/6249.
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The consequences of structured flows continue to be a pressing topic in relating spectral data to physical processes occurring in massive star winds. In a preceding paper, our group reported on hydrodynamic simulations of hypersonic flow past a rigid spherical clump to explore the structure of bow shocks that can form around wind clumps. Here we report on profiles of emission lines that arise from such bow shock morphologies. To compute emission line profiles, we adopt a two-component flow structure of wind and clumps using two “beta” velocity laws. While individual bow shocks tend to generate double-horned emission line profiles, a group of bow shocks can lead to line profiles with a range of shapes with blueshifted peak emission that depends on the degree of X-ray photoabsorption by the interclump wind medium, the number of clump structures in the flow, and the radial distribution of the clumps. Using the two beta law prescription, the theoretical emission measure and temperature distribution throughout the wind can be derived. The emission measure tends to be power law, and the temperature distribution is broad in terms of wind velocity. Although restricted to the case of adiabatic cooling, our models highlight the influence of bow shock effects for hot plasma temperature and emission measure distributions in stellar winds and their impact on X-ray line profile shapes. Previous models have focused on geometrical considerations of the clumps and their distribution in the wind. Our results represent the first time that the temperature distribution of wind clump structures are explicitly and self-consistently accounted for in modeling X-ray line profile shapes for massive stars.
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Friman, Sonja I. [Verfasser], e Bernd [Akademischer Betreuer] Jähne. "Laboratory investigations of concentration and wind profiles close to the wind-driven wavy water surface / Sonja Isabella Friman ; Betreuer: Bernd Jähne". Heidelberg : Universitätsbibliothek Heidelberg, 2020. http://nbn-resolving.de/urn:nbn:de:bsz:16-heidok-283105.
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Friman, Sonja Isabella [Verfasser], e Bernd [Akademischer Betreuer] Jähne. "Laboratory investigations of concentration and wind profiles close to the wind-driven wavy water surface / Sonja Isabella Friman ; Betreuer: Bernd Jähne". Heidelberg : Universitätsbibliothek Heidelberg, 2020. http://d-nb.info/1210490013/34.
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Berg, Allison M. "The feasibility of sodar wind profile measurements from an oceanographic buoy". Thesis, (37 MB), 2006. http://handle.dtic.mil/100.2/ADA471871.
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Thesis (M.S.)--Massachusetts Institute of Technology at Woods Hole Oceanographic Institution, 2006."September 2006." Description based on title screen as viewed on June 8, 2010. DTIC Descriptor(s): Doppler Radar, Wind Velocity, Sound Ranging, Doppler Sonar, Buoys, Measurement, Motion, Oceanographic Equipment, Theses DTIC Identifier(s): Doppler Sodar, Sodar (Sound Detection and Ranging), ASIS Includes bibliographical references (leaf 75). Also available in print.
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Berg, Allison M. (Allison May). "The feasibility of sodar wind profile measurements from an oceanographic buoy". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/38510.
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Thesis (S.M.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (leaf 75).
This thesis explores the feasibility of making wind speed profile measurements from an oceanographic buoy using a Doppler sodar. In the fall of 2005, we deployed a Scintec SFAS sodar on an ASIS buoy. Roughly one week of buoy motion data and one day of sodar observations were collected. Data from both this deployment, and the Martha's Vineyard Coastal Observatory, were used in conjunction with models to predict sodar performance. Results are compared for an ASIS and a 3-meter discus buoy. We also predict the yearly average probability of sodar data availability in the presence of buoy motion. We show that buoy tilting in response to wave forcing is the main factor affecting sodar performance. Our results strongly suggest that ASIS is a suitable platform for sodar measurements at sea.
by Allison M. Berg.
S.M.
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Streed, Daniel H. "High-frequency meteorological phenomena observed with the Naval Postgraduate School's UHF Doppler Wind Profiler". Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA243762.
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Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, December 1990.Thesis Advisor(s): Nuss, Wendell A. Second Reader: Wash, C. H. "December 1990." Description based on title screen as viewed on March 30, 2010. DTIC Descriptor(s): Marine Meteorology, Meteorological Radar, Wind, Specifications, Comparison, Doppler Radar, Accuracy, Theses, Meteorological Data, Time, Short Range(Time), Reliability, Profiles, Scale, Data Acquisition, California, Inversion, Statistical Analysis, Meteorological Phenomena, Radiosondes, Schools, Ultrahigh Frequency, High Frequency, Contracts. DTIC Identifier(s): Wind Profilers. Author(s) subject terms: Doppler Wind Profiler, Wind Profiler, Doppler Radar. Includes bibliographical references (p. 115-117). Also available in print.
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Caeiro, Olaio Valente Maria Antonia. "Effects of directional wind shear on orographic gravity wave drag". Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325212.
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Ignace, Richard, e A. Brimeyer. "Models of Forbidden Line Emission Profiles from Axisymmetric Stellar Winds". Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etsu-works/6268.
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A number of strong infrared forbidden lines have been observed in several evolved Wolf–Rayet (WR) star winds, and these are important for deriving metal abundances and testing stellar evolution models. In addition, because these optically thin lines form at large radius in the wind, their resolved profiles carry an imprint of the asymptotic structure of the wind flow. This work presents model forbidden line profile shapes formed in axisymmetric winds. It is well known that an optically thin emission line formed in a spherical wind expanding at constant velocity yields a flat-topped emission profile shape. Simulated forbidden lines are produced for a model stellar wind with an axisymmetric density distribution that treats the latitudinal ionization self-consistently and examines the influence of the ion stage on the profile shape. The resulting line profiles are symmetric about line centre. Within a given atomic species, profile shapes can vary between centrally peaked, doubly peaked, and approximately flat-topped in appearance depending on the ion stage (relative to the dominant ion) and viewing inclination. Although application to WR star winds is emphasized, the concepts are also relevant to other classes of hot stars such as luminous blue variables and Be/B[e] stars.
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Odeh, Yousre. "Wind Power Potential in Palestine/Israel : An investigation study for the potential of wind power in Palestine/Israel, with emphasis on the political obstacles". Thesis, Högskolan på Gotland, Institutionen för kultur, energi och miljö, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-217094.
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Wind resource assessment studies have been conducted in the Israeli side and the Palestinian side before; however, the previous studies were restricted with the political border either Palestinian or Israeli except one of them that was based on measurements dated to 1940-1983 (R. Shabbaneh & A. Hasan, 1997). Moreover, the studies were performed years ago, with simple techniques and based on old data (R. Shabbaneh & A. Hasan, 1997). Hence, the needs for a new study that is based on updated data, and using updated model is highly demanded. This study is intended to perform wind resource assessment in Palestine/Israel; the study has used two stages of assessment, primary one based on reference station data on both sides, Israeli and Palestinian. The second stage of wind resource assessment is based on WindPRO software. The wind resource assessment ends up with identifying sites with higher potential that are situated in four selected sites, North of Palestine/Israel, North of West-bank, Jerusalem, and Eilat, the higher potential was in Eilat area bearing mean wind speed of 9.88m/s at 100 m hub height.Moreover, the study recognized the importance of political situation assessment due to the Israeli-Palestinian conflict. Based on conducted survey, the political situation assessment concluded that international non-governmental organizations seem to be most capable of starting up wind power project in Palestine/Israel. Furthermore, the study concluded that supportive policies from both the Israeli and Palestinian governments are crucial to promote wind power projects in the region.
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Datta, Seema. "Computer-aided technique for blending wine : application of simplex optimization to headspace gas chromatographic profiles of wine". Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/28972.
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An objective method to blend wines for standardizing flavor quality was developed. Aroma volatiles of varietal and white stock wines were analyzed at 6°C and 37°C by headspace gas chromatography with cryofocussing. Pattern similarity constants of the chromatographic profiles were entered into the simplex optimization program which determined the best blending ratios of wines to simulate the target wine. Thirteen and 23 vertices were required to give the optimum response for trials 1 and 2, respectively. For both trials the computer optimized blends could not be differentiated from the target wines by a sensory taste panel consisting of both untrained and expert judges.Land and Food Systems, Faculty of
Graduate
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Charreron, Damien, e David Moreno. "Case study wind turbine at Läkerol Arena". Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-7296.
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Masiulis, Paulius. "Bepiločio skraidančio sparno aerodinaminių charakteristikų tyrimas". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140625_094638-60072.
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Šiame darbe nagrinėjamos bepiločio skraidančio sparno aerodinaminės charakteristikos. Pasirinktas sparno profilis EPPLER 328. Pirmiausia išanalizuojami skaitiniai aerodinaminių charakteristikų tyrimo metodai. Atlikus skaičiavimus pagal pasirinktus aspektus, naudojant programą XFLR5 gauti duomenys apibendrinami bei išanalizuojami. Ištirtos keliamosios jėgos koeficientų, pasipriešinimo jėgos koeficientų, aerodinaminės kokybės reikšmės esant atitinkamiems atakos kampams. Naudojantis tyrimo rezultatais padarytas bepilotis skraidančio sparno orlaivis ir atlikti skrydžiai. Visa informacija apibendrinama ir pateikiamos gautų rezultatų išvados. Darbo apimtis – 66 p. teksto be priedų, 39 paveikslai, 6 lentelės, 24 bibliografiniai šaltiniai.The investigation analyzes unmanned flying wing aerodynamic characteristics. Choosen airfoil EPPLER 328. Firstly, analyzing theoretical calculation methods. All relative data compared and analyzed after calculation with program XFLR5. Analyzed lift force coefficient, drag force coefficient, aerodynamic coefficient under realative angles of attack. Unmanned flying wing was built using the results of compared and analyzed aerodynamic data and test flights were made. All information summarized and produced conclusion. Thesis consists of: 66 p. text without appendixes, 39 pictures, 6 tables, 24 bibliographical entries.
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Hedlund, Erik. "High-fidelity 3D acoustic simulations of wind turbines with irregular terrain and different atmospheric profiles". Thesis, Uppsala universitet, Avdelningen för beräkningsvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-298754.
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We study noise from wind turbines while taking irregular terrain and non-constant atmosphere into consideration. We will show that simulating the distribution of 3D acoustic waves can be done by using only low frequencies, thus reducing the computational complexity significantly.
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Shinozuka, Yohei. "Sea-Salt Optical Properties Over the Remote Oceans: Their Vertical Profiles and Variations with Wind Speed". Thesis, University of Hawaii at Manoa, 2002. http://hdl.handle.net/10125/6961.
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The size distribution and scattering coefficient of the marine aerosol was measured over the Southern Ocean during the First Aerosol Characterization Experiment (ACE 1) and over the tropical Pacific Ocean during the Second Pacific Exploratory Mission in the Tropics (PEMT-B). Thermal analysis of particles at near ambient temperature (40 °C), 150 °C, and 300 °C enabled us to estimate size distributions of the volatile (mostly sulfate and organic) and refractory (mostly sea-salt) modes as well as their contributions to optical depth and cloud condensation nuclei. When averaged spatially and temporally, sea-salt concentrations show dependence upon wind speed over the Southern Ocean up to an altitude of 1200 m. Their median contribution to column optical depth is 0.057, 0.033, and 0.021 at wind speed >10 m/s, 5 -10 m/s, and ≤ 5 m/s, respectively, and the median over all wind speed categories is 0.041. However, on a case-by-case basis, the physical and optical properties show a large variance due to other meteorological conditions. The scales of this variability are also discussed along with examples of processes that contribute to them such as cloud processing and vertical wind speed gradient.ix, 95 leaves
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Bezerra, Josà heldenir Pinheiro. "Profile aerodynamic modeling of blades constructed of fibre vegetable for small wind turbine". Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14890.
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Universidade Federal do CearÃPower generation wind-power in cities of Cearà donât represent a significant percentage of the power generation in the state. Although Cearà has favorable winds to use a small commercial windâs turbines, this isnât a practice that belongs to these cities. Possible causes of the low rate might be: few researches for development of compatible equipment with low winds and low cost, the fact that Brazilian companies doesnât offer wind generators appropriate for the area, most of the equipment used in the country is imported and often apllied for type of winds and climate conditions different of the CearÃâs - which puts the equipments in its low perform- , repair difficulties and problems with the security operations (guide). For development of this work was used machines, tools and software such as SolidEdge version ST6, Computer-aided design (CAD) NX4 in the design and communication with vertical machining center, general tools, equipment for painting and application of resins, vacuum pump, measuring instruments volume (beaker, measuring cylinder etc.), analytical balance and pipettes. The technique used for the manufacture of the blades was vacuum infusion, relatively simple procedure and has the advantage to reduce volatile emissions with the use of closed molds. The selection of the profile e-61 was obtained by data from the software FoilSimIII and JavaFoil, which indicates the good chosen for lift aerodynamic coefficient. The carnauba fiber was used as reinforcement in composite to produce the blades with different resins, which makes it possible the use of manpower and local level raw materials to the construction of wind blades, being reinforced with vegetable carnauba fibers and polyester resins
A geraÃÃo de energia eÃlica-elÃtrica no interior do Cearà nÃo representa um percentual significativo na geraÃÃo de energia do Estado. Apesar de possuir ventos favorÃveis durante o ano inteiro, a utilizaÃÃo de aerogeradores comerciais de pequeno porte nÃo à uma prÃtica local. As possÃveis causas do baixo Ãndice sÃo: as poucas pesquisas voltadas para desenvolvimento de equipamentos compatÃvel com baixos ventos e de baixo custo, a ausÃncia de empresas brasileiras que ofereÃam geradores eÃlicos, o uso de equipamentos importados e com aplicaÃÃes para ventos e condiÃÃes climÃticas diferenciadas do interior cearense â acarretando baixo rendimento -, os problemas de manutenÃÃo, os erros nas operaÃÃes de seguranÃa e as dificuldades de reparo. Para desenvolver esse trabalho foram utilizados mÃquinas, ferramentas e softwares como SolidEdge versÃo ST6, Computer-aided design (CAD) NX4 no desenho e comunicaÃÃo com centro de usinagem vertical, ferramentas em geral, equipamentos para pinturas e aplicaÃÃo de resinas, bomba de vÃcuo, instrumentos de mediÃÃo de volume (bÃquer, proveta etc.), balanÃa de precisÃo e pipetas. A tÃcnica utilizada na fabricaÃÃo das pÃs foi à infusÃo a vÃcuo, processo relativamente simples e com a vantagem de reduzir a emissÃo volÃtil com uso de moldes fechados. A escolha do perfil e-61 para modelar foi obtido por meio de dados do software JavaFoil e FoilSimIII, indicando o perfil escolhido com um bom coeficiente de sustentaÃÃo aerodinÃmico. A fibra de carnaÃba foi utilizada como reforÃo no compÃsito para produÃÃo das pÃs com diferentes resinas, o que possibilita o uso de mÃo de obra e matÃria prima local na construÃÃo de pÃs eÃlicas reforÃada com fibras vegetais de carnaÃba e resinas poliÃster
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Grice, Robert Lewis. "Personality profiles of experienced U.S. Army rotary-wing aviators across mission platforms /". Lynchburg, Va. : Liberty University, 2006. http://digitalcommons.liberty.edu.
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Igance, Richard. "Modeling X-ray Emission Line Profiles from Massive Star Winds - A Review". Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/2686.
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The Chandra and XMM-Newton X-ray telescopes have led to numerous advances in the study and understanding of astrophysical X-ray sources. Particularly important has been the much increased spectral resolution of modern X-ray instrumentation. Wind-broadened emission lines have been spectroscopically resolved for many massive stars. This contribution reviews approaches to the modeling of X-ray emission line profile shapes from single stars, including smooth winds, winds with clumping, optically thin versus thick lines, and the effect of a radius-dependent photoabsorption coefficient.
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Oliveira, Mariana Schmidt de. "Análise de pás para aerogeradores de eixo horizontal aplicados à geração de microenergia". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/163768.
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A geração de energia elétrica por meio de aerogeradores de microporte vem ganhando espaço em várias partes do mundo; porém, estudos que descrevem e analisam este artefato, ainda são restritos se comparados a aerogeradores de médio e grande porte. Países como China e Estados Unidos, por exemplo, buscam cada vez mais estudar a microgeração de energia eólica, servindo como motivação para que exista maior número de estudos neste campo, também aqui no país. Neste sentido, a presente pesquisa apresenta análise de perfis NACA com diferentes ângulos de passo visando a microgeração de energia eólica. Para tanto realizou-se levantamento das velocidades de vento na parte superior de um prédio localizado no centro de Porto Alegre durante 5 dias e os perfis aerodinâmicos foram testados no programa computacional Q-Blade. Selecionou-se 3 perfis NACA (0012, 6409, 1412), 3 ângulos de passo (15º, 30° e 45º) e 5 velocidades de vento (de 1m/s à 5 m/s). Os modelos analisados foram obtidos através de impressão 3D. Foram então realizados ensaios aerodinâmicos utilizando o túnel de vento nos quais foram medidos o número de rotação por minuto (RPM), a velocidade de vento da partida da hélice, a tensão, corrente e a potência elétrica, geradas para diferentes configurações de ensaio. O trabalho contribui no sentido de auxiliar projetos que envolvam design e tecnologia que visem à melhoria da funcionalidade prática de microgeradores eólicos de eixo horizontal para as diversas aplicações possíveis. Os resultados apontam que o ângulo de passo de 45º apresenta os maiores índices de rotação, tensão, corrente e potência elétrica para todos os perfis NACA analisados, sendo o perfil NACA 0012 o de maior destaque em relação a esses mesmos parâmetros.Electric power generation by small scale wind turbines has been gaining space in several parts of the world, however, studies that describe and analyze this artefact, are still more restrict in comparison to medium and large scale wind turbines. Countries such as China and the United States, for example, are increasingly seek to study wind power microgeneration, working as a motivator in order to increase the number of studies in the field, even here in the country. In this matter, the present research presents an analysis of NACA profiles with different pitch angles seeking wind energy microgeneration. In order to do so, it was gathered the wind speed of the top portion of a building located in central Porto Alegre during 5 days and the aerodynamic profiles were tested in the computer program Q-Blade. 3 NACA profiles (0012, 6409, 1412), 3 pitch angles (15º, 30° e 45º) and 5 wind velocities (1m/s to 5 m/s) were selected. The analyzed models were obtained through 3D printing. Aerodynamical tests were performed using the Wind tunnel and were observed the number of rotation per minute (RPM), the wind speed start of the propeller, electric tension, current and power generated for different test configurations. The work contributes to assisting projects that involves design and technology aimed at improving the practical functionality of horizontal axis wind generators for the various possible applications. The results indicate that the 45º pitch angle presents the highest rates of rotation, electric tension, current and power for all the NACA profiles analyzed, with the NACA 0012 profile being the most prominent in relation to these same parameters.
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Logan, Gerard Anthony. "The impact of vineyard and cellar factors on the color and anthocyanin profile of Pinot noir grapes and table wines". Diss., Connect to online resource - MSU authorized users, 2006.
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Hendry, M., Richard Ignace e H. Bryce. "Microlensing of Circumstellar Envelopes III. Line Profiles from Stellar Winds in Homologous Expansion". Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etsu-works/6270.
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This paper examines line profile evolution due to the linear expansion of circumstellar material obsverved during a microlensing event. This work extends our previous papers on emission line profile evolution from radial and azimuthal flow during point mass lens events and fold caustic crossings. Both “flavours” of microlensing were shown to provide effective diagnostics of bulk motion in circumstellar envelopes. In this work a different genre of flow is studied, namely linear homologous expansion, for both point mass lenses and fold caustic crossings. Linear expansion is of particular relevance to the effects of microlensing on supernovae at cosmological distances. We derive line profiles and equivalent widths for the illustrative cases of pure resonance and pure recombination lines, modelled under the Sobolev approximation. The efficacy of microlensing as a diagnostic probe of the stellar environs is demonstrated and discussed
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Von, Mollendorff Anke. "The impact of wine yeast strains on the aromatic profiles of Sauvignon blanc wines derived from characterized viticultural treatments". Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80181.
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Thesis (MScAgric)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Grape must is a complex medium, and during wine production numerous biochemical pathways and metabolic reactions are taking place simultaneously to produce a specific taste and aroma. Microorganisms, specifically yeast, play a key role in the formation of metabolites formed during alcoholic fermentation. Sauvignon blanc, a well studied grape cultivar, is known to have a versatile range of aroma profiles ranging from “green” to “tropical”. It has been broadly stated that a “green” Sauvignon blanc can be created in the vineyard and a “tropical” Sauvignon blanc can be created by selecting a specific yeast strain, and that the balance between “green” and “tropical” characters is essential for the final aroma profile. Except for grape-derived varietal aromatic compounds such as methoxypyrazines (green), volatile thiols (tropical) and monoterpenes (floral), yeast derived volatile compounds including esters, higher alcohols, fatty acids and carbonyl compounds will also contribute to the final wine aroma. The main aim of this study was to assess how viticultural treatment-derived differences in grape must, can impact on aroma production when this grape must is fermented with different commercial wine yeast strains. The viticulture treatment focused on light intensity modulated through canopy treatment. Volatile aroma differences were compared for canopy and yeast treatments, specifically focusing on the fermentation derived bouquet (esters, higher alcohols, volatile fatty acids, carbonyl compounds and monoterpenes). Results showed significant differences between initial must compositions, including titratable acidity, malic acid and yeast assimilable nitrogen. The volatile aroma compounds were also significantly impacted although no noticeable effect on the overall fermentation kinetics was observed. Depending on the yeast strain differences in volatile compounds varied. A clear vintage effect is noticeable between volatile compounds affected by the treatments. Data generated in 2012 shows clear differences between ethyl- and acetate esters and could clearly be grouped according to yeast strain through multivariate analysis. Sensory evaluation results could clearly be distinguished according to canopy treatment and to a lesser degree according to yeast strain used. This indicates that although yeast has a more prominent impact on the fermentative bouquet that develops during alcoholic fermentation the overriding aroma is primarily derived from grape-derived metabolites which can be manipulated by canopy treatments. None the less the difference in fermentation bouquet does add to the complexity of the wine especially in the case of fermentation derived “tropical” aromas including guava and passion fruit. In some cases where shaded grapes had higher ester concentrations, the resultant wine also had higher aroma quality. This study has contributed to a better understanding of the complex relationships between canopy manipulation and yeast selection on aroma formation. The analysis of volatile aroma alone however is not enough to understand the final perception of wine taste and further indepth studies of the viticultural and oenological factors is needed. In particular, this project has focused on a single vineyard over only two vintages. The general validity of the conclusions derived from this study therefore will require additional data sets.
AFRIKAANSE OPSOMMING: Druiwemos is ‘n komplekse medium en tydens wynbereiding is daar verskeie biochemiese weë en metaboliese reaksies wat gelyktydig plaasvind om ‘n spesifieke smaak en aroma te produseer. Mikro-organismes, veral gis, speel ‘n sleutelrol in die vorming van metaboliete tydens alkoholiese gisting. Sauvignon blanc, ‘n goed bestudeerde druifkultivar, besit ‘n veelsydige reeks aromaprofiele wat wissel van “groen” tot “tropies”. Oor die algemeen word dit voorgehou dat ‘n “groen” Sauvignon blanc in die wingerd geskep word, terwyl ‘n “tropiese” Sauvignon blanc geskep kan word deur ‘n spesifieke gisras te selekteer, en die balans tussen “groen” en “tropiese” karakters is noodsaaklik vir die finale aromaprofiel. Behalwe vir druifafgeleide kultivarafhanklike aromatiese verbindings soos metoksipirasiene (groen), vlugtige tiole (tropies) en monoterpene (blomagtig), sal gisafgeleide vlugtige komponente, waaronder esters, hoër alkohole, vetsure en karbonielverbindings, ook tot die finale wynaroma bydra. Die hoofdoelwit van hierdie studie was om te bepaal hoe verskille in druiwemos wat afkomstig is van wynkundige behandeling ‘n impak op aromaproduksie kan hê wanneer hierdie druiwemos met verskillende kommersiële wyngisrasse gegis word. Die wynkundige behandeling het gefokus op ligintensiteit wat deur lowerbehandeling gereguleer is. Vlugtige aromaverskille is op grond van lower- en gisbehandelings vergelyk, met ‘n spesifieke fokus op die gistingsafgeleide boeket (esters, hoër alkohole, vlugtige vetsure, karbonielverbindings en monoterpene). Die resultate het beduidende verskille getoon tussen aanvanklike mossamestellings, waaronder titreerbare suurheid, appelsuur en gis-assimileerbare stikstof. Daar was ook ‘n noemenswaardige impak op die vlugtige aromaverbindings, hoewel geen merkbare effek op die algehele gistingskinetika waargeneem kon word nie. Die verskille in vlugtige verbindings het gewissel op grond van die gisras. ‘n Duidelike oesjaareffek was merkbaar tussen vlugtige verbindings wat deur die behandelings geaffekteer is. Data wat in 2012 gegenereer is, toon duidelike verskille tussen etiel- en asetaatesters en kon duidelik m.b.v. meervariantanalise volgens gisras gegroepeer word. Die resultate van die sensoriese evaluering kon duidelik volgens lowerbehandeling onderskei word, en tot ‘n mindere mate volgens die gisras wat gebruik is. Dít dui daarop dat hoewel gis ‘n meer prominente impak het op die gistingsboeket wat tydens alkoholiese gisting ontwikkel, is die oorheersende aroma hoofsaaklik afgelei van druifafgeleide metaboliete wat deur lowerbehandelings gemanipuleer kan word. Nietemin dra die verskil in gistingsboeket by tot die kompleksiteit van die wyn, veral in die geval van gistingsafgeleide “tropiese” aromas, insluitend koejawel en grenadella. In sommige gevalle waar beskadude druiwe hoër esterkonsentrasies gehad het, het die gevolglike wyn ook ‘n hoër aromakwaliteit gehad. Hierdie studie dra by tot ‘n beter begrip van die effek van die komplekse verhoudings tussen lowermanipulasie en gisseleksie op aromavorming. ‘n Analise van vlugtige aroma alleen is egter nie voldoende om die finale persepsie van wynsmaak te begryp nie en bykomende diepgaande studies van die wingerdkundige en wynkundige faktore word benodig. Hierdie projek het in die besonder gefokus op ‘n enkele wingerd oor slegs twee oesjare. Die algemene geldigheid van die afleidings wat van hierdie studie gemaak word, sal dus bykomende datastelle vereis.
The National Research Foundation and Postgraduate Merit Bursary for financial support
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Olsson, Niklas, e Christian Selberg. "Numerical simulation and experimental validation of a manufactured wing profile". Thesis, Högskolan Väst, Avdelningen för Industriell ekonomi, Elektro- och Maskinteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-14287.
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The background for this thesis originates from a study of the flow characteristics for an airfoil of the type NACA0018. The aim for this thesis was to evaluate how the characteristics of the flow over the NACA0018 profile depend on surface roughness. Airfoils were manufactured in Aluminum by Computer Numerical Control-milling and in polylactide polymer using a 3D-printer, where some of the profile surfaces were postprocessed with sandpaper in various grain sizes. The surface roughness of the profiles was evaluated in a 3D optical profilometer using white light interferometry from Filmetrics. By that technique 3D surface plots were created. The manufactured airfoils were tested in a wind tunnel where the achieved data was made dimensionless for comparative purposes. The computational fluid dynamics simulations were performed in Ansys Fluent and compared against the wind tunnel data as well as with the data from a previously made study at htw saar. The results from the wind tunnel tests show that the surface roughness has an effect on the flow characteristic of the airfoil, where different angles of stall were observed in the comparison. The difference for the dimensionless numbers coefficient of lift and drag show that the manufactured aluminum airfoil performs better compared to the 3D-Printed airfoil in this study. It has a higher performance mean value for both of these coefficients in a span of angles between 0 and 30 degrees. When compared, the results from the simulations and wind tunnel experiments do match in some cases, where the dimensionless coefficients and stall angle coheres. Further studies based on this report are recommended, where small geometric changes to the profile could be tested and validated.
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Jiang, Mengdi. "Quaternion-valued adaptive signal processing and its applications to adaptive beamforming and wind profile prediction". Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/16318/.
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Quaternion-valued signal processing has received more and more attentions in the past ten years due to the increasing need to process three or four-dimensional signals, such as colour images, vector-sensor arrays, three-phase power systems, dual-polarisation based wireless communica- tion systems, and wind profile prediction. One key operation involved in the derivation of all kinds of adaptive signal processing algorithms is the gradient operator. Although there are some derivations of this operator in literature with different level of details in the quaternion domain, it is still not fully clear how this operator can be derived in the most general case and how it can be applied to various signal processing problems. In this study, we will give a detailed derivation of the quaternion-valued gradient operator with associated properties and then apply it to different areas. In particular, it will be employed to derive the quaternion-valued LMS (QLMS) algorithm and its sparse versions for adaptive beamforming for vector sensor arrays, and another one is its application to wind profile prediction in combination with the classic computational fluid dynamics (CFD) approach. For the adaptive beamforming problem for vector sensor arrays, we consider the crossed- dipole array and the problem of how to reduce the number of sensors involved in the adap- tive beamforming process, so that reduced system complexity and energy consumption can be achieved, whereas an acceptable performance can still be maintained, which is particularly use- ful for large array systems. The quaternion-valued steering vector model for crossed-dipole arrays will be employed, and a reweighted zero attracting (RZA) QLMS algorithm is then pro- posed by introducing a RZA term to the cost function of the original QLMS algorithm. The RZA term aims to have a closer approximation to the l0 norm so that the number of non-zero valued coefficients can be reduced more effectively in the adaptive beamforming process. For wind profile prediction, it can be considered as a signal processing problem and we can solve it using traditional linear and non-linear prediction techniques, such as the proposed QLMS algorithm and its enhanced frequency-domain multi-channel version. On the other hand,it using traditional linear and non-linear prediction techniques, such as the proposed QLMS algorithm and its enhanced frequency-domain multi-channel version. On the other hand,wind flow analysis is also a classical problem in the CFD field, which employs various simulation methods and models to calculate the speed of wind flow at different time. It is accurate but time-consuming with high computational cost. To tackle the problem, a combined approach based on synergies between the statistical signal processing approach and the CFD approach is proposed. There are different ways of combining the signal processing approach and the CFD approach to obtain a more effective and efficient method for wind profile prediction. In the combined method, the signal processing part employs the QLMS algorithm, while for the CFD part, large eddy simulation (LES) based on the Smagorinsky subgrid-scale (SGS) model will be employed so that more efficient wind profile prediction can be achieved.
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Schulze, Karl Werner. "An investigation into the contamination of WSR-88D VAD wind profile output by migrating birds". Texas A&M University, 2003. http://hdl.handle.net/1969/276.
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Fujita, Shiho. "Reproductive Biology in Wild Female Primates : Variability in Hormonal Profiles, Behavior and Reproductive Parameters". 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/149150.
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Reichheld, Dean. "An investigation of the use of VAD analysis and UHF profiler data to obtain a 2-D wind field". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ37158.pdf.
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Garcia, Jason S. "Design, Construction, and Characterization of the University of South Florida Wind Tunnel". Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7294.
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Much of the aerosol research completed at the University of South Florida has revolved around evaluating industrial hygiene equipment and instrumentation in environmental chambers. Data collected during these studies has provided valuable baseline data on equipment and instrument performance under calm air conditions. A newly constructed wind tunnel now allows researchers to evaluate industrial hygiene instruments under moving air conditions. Because the wind tunnel is capable of producing wind velocities that a worker could encounter in the occupational setting, researchers may gain insight into instrument performance under simulated field conditions. Because aerosols can be introduced into the new wind tunnel testing section, researchers can also challenge industrial hygiene equipment and instrumentation with aerosols in sizes ranges that are of interest in public health.
The purpose of this dissertation research was to develop a new wind tunnel to be used for aerosol research at the University of South Florida. Three specific aims had to be met for this study to be successful. They included: (1) designing a wind tunnel based on best practice information outlined in scientific literature, (2) constructing an operable wind tunnel to be used for aerosol research, and (3) characterizing wind tunnel performance by examining the wind tunnel velocity profile, turbulence intensity, and aerosol introduction/collection. The actual wind tunnel was constructed to a length of approximately 20 feet, a height of approximately 2 feet at its tallest point, and includes an entrance filter housing, a settling chamber, a contraction, a testing section, a diffuser, an exit filter housing, a fan, and exhaust duct. All components were designed and constructed using guidelines and best practices reported in the scientific literature.
Velocity profile measurements were the first way that this wind tunnel was characterized. In order to successfully obtain measurements, the wind tunnel cross section was divided into 16 equal quadrants. Five measurements were taken for each quadrant at each wind velocity. Target wind velocities for this research were 0.5 m/s, 1.0 m/s, and 2.0 m/s. Actual average wind velocities of 0.48 m/s, 1.00 m/s, and 2.04 m/s. All were within established limits reported in the scientific literature.
Turbulence intensity measurements were the second way that this wind tunnel was characterized. In order to successfully obtain measurements, the wind tunnel cross section was divided into 16 equal quadrants. Five measurements were taken for each quadrant at each wind velocity. Wind tunnels are typically designed to have the lowest turbulence intensity possible, generally below 10%. The overall average turbulence intensities for this wind tunnel at wind velocities of 0.5 m/s, 1.0 m/s, and 2.0 m/s were 9%, 10%, and 8% respectively. Overall turbulence intensity measurements were at or below 10%.
Isokinetic sampling was the final method used to characterize this wind tunnel by collecting and detecting aerosols traveling through the wind tunnel testing section. The wind tunnel was operated at wind velocities of 0.5 m/s, 1.0 m/s, and 2.0 m/s with isokinetic sampling flow rates of 15.4 L/min, 30.9 L/min, and 61.7 L/min respectively. Monodisperse fluorescent polystyrene latex spheres were used as the test aerosol because they are uniform in size and shape and can be detected by fluorometry. The Blaustein Multi-Jet Atomizer (BLAM) was used to generate monodisperse fluorescent polystyrene latex aerosol 0.5 µm and 2.0 µm particles from liquid suspensions. The Vilnius Aerosol Generator (VAG) was used to generate monodisperse fluorescent polystyrene latex aerosol of 6.0 µm and 12.0 µm particles from dry powders. Nitrogen gas was used for delivering test aerosols into the wind tunnel. Five experimental runs were completed for each particle size and wind velocity for a total of 60 experimental runs. Fluorescence was detected in all 60 samples with average mass concentrations ranging from 0.000050 ng/ml to 0.002703 ng/ml.
Based on velocity profile measurements, turbulence intensity measurements, and isokinetic sampling, the performance of University of South Florida wind tunnel was found to be excellent, indicating that it was designed and constructed appropriately. The wind tunnel can now successfully be used by researchers interested in evaluating industrial hygiene sampling equipment with aerosols ranging from 0.5 µm to 12.0 µm in moving air with velocities ranging from 0.5 m/s to 2.0 m/s.
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Jaafar, Amine. "Traitement de la mission et des variables environnementales et intégration au processus de conception systémique". Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0070/document.
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Ce travail présente une démarche méthodologique visant le «traitement de profils» de «mission» et plus généralement de «variables environnementales» (mission, gisement, conditions aux limites), démarche constituant la phase amont essentielle d’un processus de conception systémique. La «classification» et la «synthèse» des profils relatifs aux variables d’environnement du système constituent en effet une première étape inévitable permettant de garantir, dans une large mesure, la qualité du dispositif conçu et ce à condition de se baser sur des «indicateurs» pertinents au sens des critères et contraintes de conception. Cette approche s’inscrit donc comme un outil d’aide à la décision dans un contexte de conception systémique. Nous mettons en particulier l’accent dans cette thèse sur l’apport de notre approche dans le contexte de la conception par optimisation qui, nécessitant un grand nombre d’itérations (évaluation de solutions de conception), exige l’utilisation de «profils compacts» au niveau informationnel (temps, fréquence,…). Nous proposons dans une première phase d’étude, une démarche de «classification» et de «segmentation» des profils basée sur des critères de partitionnement. Cette étape permet de guider le concepteur vers le choix du nombre de dispositifs à concevoir pour sectionner les produits créés dans une gamme. Dans une deuxième phase d’étude, nous proposons un processus de «synthèse de profil compact», représentatif des données relatives aux variables environnementales étudiées et dont les indicateurs de caractérisation correspondent aux caractéristiques de référence des données réelles. Ce signal de durée réduite est obtenu par la résolution d’un problème inverse à l’aide d’un algorithme évolutionnaire en agrégeant des motifs élémentaires paramétrés (sinusoïde, segments, sinus cardinaux). Ce processus de «synthèse compacte» est appliqué ensuite sur des exemples de profils de missions ferroviaires puis sur des gisements éoliens (vitesse du vent) associés à la conception de chaînes éoliennes. Nous prouvons enfin que la démarche de synthèse de profil représentatif et compact accroît notablement l’efficacité de l’optimisation en minimisant le coût de calcul facilitant dès lors une approche de conception par optimisationThis work presents a methodological approach aiming at analyzing and processing mission profiles and more generally environmental variables (e.g. solar or wind energy potential, temperature, boundary conditions) in the context of system design. This process constitutes a key issue in order to ensure system effectiveness with regards to design constraints and objectives. In this thesis, we pay a particular attention on the use of compact profiles for environmental variables in the frame of system level integrated optimal design, which requires a wide number of system simulations. In a first part, we propose a clustering approach based on partition criteria with the aim of analyzing mission profiles. This phase can help designers to identify different system configurations in compliance with the corresponding clusters: it may guide suppliers towards “market segmentation” not only fulfilling economic constraints but also technical design objectives. The second stage of the study proposes a synthesis process of a compact profile which represents the corresponding data of the studied environmental variable. This compact profile is generated by combining parameters and number of elementary patterns (segment, sine or cardinal sine) with regards to design indicators. These latter are established with respect to the main objectives and constraints associated to the designed system. All pattern parameters are obtained by solving the corresponding inverse problem with evolutionary algorithms. Finally, this synthesis process is applied to two different case studies. The first consists in the simplification of wind data issued from measurements in two geographic sites of Guadeloupe and Tunisia. The second case deals with the reduction of a set of railway mission profiles relative to a hybrid locomotive devoted to shunting and switching missions. It is shown from those examples that our approach leads to a wide reduction of the profiles associated with environmental variables which allows a significant decrease of the computational time in the context of an integrated optimal design process
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Robbins, Lisa R. "The Effects of Hyperoxidation and Storage Temperatures on the Flavor Profile and Sensory Quality of Riesling Wine". The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1511893070533362.
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