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 20 of 85 for “"radial velocity"”.
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A New Mass Measurement for Galaxy Clusters Using Position and Radial Velocity
… paper written by Popesso that contained publishedvelocity dispersions for each cluster (Popesso, 2006). The profiles we acquire through thetiming argument have a useful astronomical application because they rely only oninfalling galaxies in the cluster, forgoing the virial theorem. We estimate a …
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Design, construction, and testing of ultrasonic transducers with modified radial velocity profiles
… with a Gaussian profile. A transducer with a velocity profile which is Gaussian as a function of radius and independent of angle is described. The transducer has been constructed by depositing a circularly symmetric metallic multiple electrode array on a 12. 7 mm diameter x-cut quartz disk. …
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Theoretical detection limits and error reduction for radial velocity observations of an Earth-like exoplanet
… determine the relationship between the number of radial velocity observations of an Earth-twin exoplanet and the error in the mass calculated from the detected signal. If the planet's period is known through prior transit observations, the mass may be measured by radial velocity more accurately; …
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A study of the beta Cephei stars
… by Frost at Yerkes in 1902 while conducting radial velocity observations. The problems associated with interpreting the short period of 4.5 hours in the radial velocity variations in terms of a binary hypothesis were immediately apparent . These problems were compounded by Guthnick's …
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A study of the beta Cephei stars
… by Frost at Yerkes in 1902 while conducting radial velocity observations. The problems associated with interpreting the short period of 4.5 hours in the radial velocity variations in terms of a binary hypothesis were immediately apparent . These problems were compounded by Guthnick's …
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The properties of transiting exoplanets
… final pieces of work of the thesis focus more on radial velocities, rather than transit events. From a transit search of K2 M-dwarfs, I compiled a list of so-called “monster” planet candidates – Jupiter-sized planets orbiting M-dwarfs. I plan obtain high-resolution spectra of these targets in …
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Experimental determination of the flow field velocity and strain rate in a laminar opposed flow H₂/air diffusion flame, via laser doppler anemometry
… was to experimentally determine the flow field velocity and corresponding strain rate under different operating flow conditions. An axisymmetric opposed jet burner was employed in this experiment where air was supplied to one circular tube, while fuel and diluent were supplied to the opposing …
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Experimental determination of strain rates in stretched laminar diffusion flames
… anemometer was used to measure the axial and radial velocity components of hydrogen-air counterflow diffusion flames (CFDF). An axisymmetric opposed jet burner (OJB) used seeded air in one cylindrical tube, and a hydrogen-nitrogen mixture in the opposing cylindrical tube. Velocity measurements …
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Effect of radial transport on compressor tip clearance flow structures and enhancement of stable flow range
… as diagnostics to assess the hypothesis that the radial transport of momentum out of the tip region, and the consequent decrease in streamwise momentum in this region, is a key aspect of the flow. The radial velocity responsible for this transport is a result of the flow field set up by the tip …
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Exoplanetary system WASP-3 : measurement of the projected spin-orbit angle and evidence for stellar activity
… on UT June 19, 2008 reveal an increase in radial velocity to a peak magnitude of 75 m s-1 larger than the expected orbital velocity. Such an anomaly was not observed during a subsequent transit. I find that a good fit to the radial velocity measurements requires omitting the anomalous data …
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Exploring methods to extract vertical motions in winter storms
… Storms (PLOWS) project. First, the profiler radial velocity measurements from two storms are compared statistically to radial velocity measurements of the Wyoming Cloud Radar (WCR) aboard the NSF/NCAR C-130 using Contoured Frequency by Altitude Diagrams (CFADs). The WCR analysis shows a …
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Exploring the Environment of Young Stars: Disks, Companions and Clusters
… filaments are analysed. 5. The first multi-epoch radial velocity survey of very young, embedded massive stars is presented. Two massive close binary stars are identified. The radial velocity measurements show large differences explainable only if substantial fraction of the young massive stars are …
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Time Series Analysis of the A0 Supergiant HR 1040
… and compared, including line equivalent width, radial velocities and Stromgren photometric indices.</p><p>Typical of late B- and early A-type supergiants, HR 1040 has a highly variable stellar wind including High Velocity Absorption (HVA) events. The star was found to have an active phase with …
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The Formation of Brown Dwarfs
… out of the twelve objects with UVES at the VLT, radial and rotational velocities have been measured with high accuracy. A kinematic study of the sample showed that their radial velocity dispersion is relatively small (2.2 kms). It is significantly smaller than the radial velocity dispersion of …
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Statistical analyses of exoplanetary systems and individual studies of the atmospheres of two sub-Neptune-sized planets
… from transit surveys and from the California radial velocity survey can be completely explained by their stellar metallicity difference, using the relation between occurrence rates and stellar properties.
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Feasibility-study for space-based transit photometry using mid-sized nanosatellites
… studies to determine the expected results of a radial velocity followup mission and transit survey mission. Optical systems on larger mid-sized nanosatellites (such as ESPA satellites) have greater potential than smaller mid-sized nanosatellites (such as CubeSats) to detect smaller planets, …
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Maps and masses of transiting exoplanets : towards new insights into atmospheric and interior properties of planets
… analyses including transits, phase curves, and radial velocity measurements. I use this method to create the first two-dimensional map and the first cloud map of an exoplanet for the hot-Jupiters HD 189733b and Kepler-7b, respectively. The second method, MassSpec, aims to determine transiting …
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Designing a Multichannel Sense-and-Avoid Radar for Small UASs
… a 40% Yak-54 model aircraft by providing range, radial velocity and angle-of-arrival (AoA) information for nearby targets. A target's range and Doppler is determined by employing a two-dimensional (2-D) Fast Fourier Transform (FFT) on the received signal which maps the target to a specific …
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Spectroscopic and photometric observations and analysis of compact binaries
… emission lines parameters and to determine the radial velocities of the systems. For 2SXPS J062339.9− 265751, spectroscopy was undertaken using the SAAO 1.9 metre telescope. In addition, time series high speed photometry, over many epochs, was also obtained and analyzed for 2SXPS …
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High Contrast Imaging: Exoplanet and Low Stellar Mass Populations
… also report the results of a FEROS radial velocity survey of low-mass binaries, the majority of which are high probability young moving group (YMG) members. YMGs are prime targets for exoplanet imaging due to their youth (∼ 10 − 100 Myr), as any potential orbiting planet will be …
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