Characterization of Lift and Drag on Two Dimensional Airfoils with and without Sinusoidal Leading Edges

An experimental investigation was taken on a 63-021 NACA airfoil, to characterize lift and drag and how the effects of sinusoidal leading edges affect the aerodynamic properties. A theoretical model is also purposed by implementing a perturbation on thin-airfoil theory. Two sets of airfoils were machined and tested inside a low-speed open circuit wind tunnel. Data from a pressure scanner and particle image velocity will give an insight of how the modified leading edges affect the aerodynamic properties. A Fourier series expansion was used to solve for the lifting-line model, by use of thin-airfoil theory and complex number theory

The Effects of Index Storage on Ranked Information Retrieval

Information retrieval is the process of recalling and ordering all relevant documents based on a user\u27s search query. Examples of information retrieval systems are Google, Bing, and Yahoo search. In order to perform an effective search, these systems utilize an inverted index for mapping content, such as words, to the original document. It is widely believed there are two options for implementing an inverted index and these options are in memory or as a file. This investigation looks at implementing an inverted index as a table in a database as compared to the other two options. In addition, this investigation will look at the optimal combination of inverted index implementation to retrieval algorithms such as TD-IDF, Best Match 25, and a unigram model with Jelinek-Mercer smoothing. This is determined by designing and developing a system which will index and search three different collections of various data, size, and complexities. By doing this, it is found that utilizing an inverted index implemented in a database is a viable option for information retrieval. It is also noteworthy that Best Match 25 or a unigram language model consistently outperforms TD-IDF. In conclusion, if the collection cannot be indexed in memory, then utilizing a database implemented index is a sufficient second option

Spin Dependence in Polarized Proton-Proton Elastic Scattering at RHIC

The STAR (Solenoidal Tracker At RHIC - Relativistic Heavy Ion Collider) experiment is equipped with Roman Pots, insertion devices that allow detectors to be moved close to the beam for the measurement of high energy protons scattered at very small angles. This setup, together with the unique capability of RHIC to collide spin-polarized proton beams, allows STAR to study both the dynamics and the spin-dependence of the proton-proton ( pp) elastic scattering process. Silicon strip detectors, installed inside the Roman Pots, measure tracks of protons scattered diffractively at very small angles. In a dedicated run with special beam optics during the 2009 RHIC run, the collaboration collected about 20 million elastic events with transversely polarized proton beams at the center of mass energy √s= 200 GeV and four momentum transfer squared (t) range of 0.003 ≤ |t| ≤ 0.035 (GeV/c)2, where, due to the Coulomb Nuclear Interference (CNI), a measurable single spin asymmetry arises. While the electromagnetic interaction can be determined in QED, the description of the hadronic interaction at small -t scattering requires the use of nonperturbative techniques in QCD, and, phenomenological models, rather than pQCD, are used to describe the exchange mechanism. High energy diffractive scattering at small-t is dominated by the Pomeron exchange, treated in pQCD as a color singlet combination of two gluons carrying quantum numbers of the vacuum (JPC = 0++). In this dissertation, I report on a high precision measurement of the transverse single spin asymmetry AN at √s= 200 GeV in pp elastic scattering at RHIC. The measured AN and its t-dependence are consistent with the absence of a hadronic spin-flip amplitude. The major contribution to the uncertainty in AN comes from the uncertainty in the beam polarization measurement. The presented results provide a precise measurement in the non-perturbative QCD regime, where experimental data are indispensable, and, a significant constraint on the spin-flip component of the Pomeron

DARKNESS: The First Microwave Kinetic Inductance Detector Integral Field Spectrograph for Exoplanet Imaging

High-contrast imaging is a powerful technique for the study of exoplanets. Combining extreme adaptive optics to correct for atmospheric turbulence, a coronagraph to suppress diffraction from the telescope aperture, and an integral field spectrograph to obtain a spectrum at every spatial element in the final image, ground-based high contrast instruments can effectively remove on-axis star light to characterize nearby faint companions and disks. Current state-of-the-art high-contrast imagers operating at near-infrared wavelengths regularly achieve contrast ratios < 10−6 at 0.5” separations. For young systems (<~10 Myr) at 10 pc, this roughly translates to detectability of Jupiter mass planets in 5 AU orbits. Tighter separations may be achieved with larger telescope apertures, but deeper contrasts are limited from the ground by residual atmospheric aberrations. Unsensed and uncorrected wavefront aberrations lead to a pattern of coherent speckles in the final image that evolve on a range of timescales from a few milliseconds to tens of minutes. The most problematic speckle population, referred to as atmospheric speckles, have lifetimes of roughly 1 s causing them to average slowly in long exposures. After subtraction of the long lived quasi-static speckles in post-processing, atmospheric speckle noise sets the ultimate contrast limits.In this thesis we present DARKNESS (the DARK-speckle Near-infrared Energy- resolving Superconducting Spectrophotometer), the first demonstration platform to utilize optical/near-infrared Microwave Kinetic Inductance Detectors (MKIDs) for high-contrast imaging. The photon counting and simultaneous low-resolution spectroscopy provided by MKIDs enable real-time speckle control techniques and post-processing speckle suppression at framerates capable of resolving the atmospheric speckles. We describe the motivation, design, and characterization of DARKNESS, its deployment behind the PALM-3000 extreme adaptive optics system and the Stellar Double Coronagraph at Palomar Observatory, early speckle characterization results at ∼ms timescales, and future prospects for implementing this data in useful speckle removal schemes