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On the geometry and topology of hyperbolic variational symbolsValero, Carlos January 1998 (has links)
No description available.
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Wave propagation and grating formation in photorefractive materialsAu, L. B. January 1988 (has links)
No description available.
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Wave propagation over complex bathymetryRay, Timothy Allen 06 1900 (has links)
Approved for public release; distribution is unlimited. / Swell propagates across thousands of kilometers of ocean in almost unchanged parallel wave fronts. Within the nearshore region however, refraction causes wave fronts to turn toward shallow depths transforming the wave field. The Nearshore Canyon Experiment (NCEX) Pilot, conducted from October 10 to October 17, 2002, observed wave transformation across the Scripps and La Jolla canyon system near San Diego, CA. Four Datawell Directional Waverider Buoys, three Nortek Vector PUV recorders, and two pressure sensors were deployed in depths ranging from 10 to 300 m. Observed energy density spectra and mean propagation directions were examined for three case studies representative of the range of observed swell conditions. Observations were compared to predictions of a back-refraction model provided by Dr. William O'Reilly. Observations indicate that refraction causes the waves to propagate along the deep axes of the Scripps and La Jolla canyons. At the shallow canyon heads, the convergence and divergence of ray trajectories cause extreme (2-3 orders of magnitude!) spatial variations in wave energy. Considering the complexity of the canyon environment, predictions of wave transformation agree surprisingly well with observations. / Ensign, United States Naval Reserve
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On the atmospheres of Saturn and cold gas giant extrasolar planetsDalba, Paul Anthony 27 November 2018 (has links)
Over the past few decades, short-period giant planets have been discovered in extrasolar planetary systems, allowing for new tests of planetary evolution theories. Many of these giant exoplanets have high temperatures (>1000 K) and do not directly resemble Jupiter or Saturn. Only in the past few years have exoplanets akin to the cold (~100 K) gas giants in the solar system been identified.
In this dissertation, I investigated giant gaseous planets through comparative studies of Saturn and exoplanets. Saturn has been the target of numerous high-precision observations, making it the ideal candidate for comparative studies. I simulated transit observations of a Saturn-analog exoplanet and determined that cold exoplanet atmospheres are amenable to characterization via transmission spectroscopy. By casting Saturn as an exoplanet, I demonstrated the potential for exoplanets to place the solar system in a Galactic context.
The transit spectrum of Saturn also highlighted the importance of atmospheric refraction in transit observations. Refraction alters the path of light propagating in an atmosphere. I showed that out-of-transit refracted light provides an opportunity to identify and characterize the atmospheres of cold transiting and non-transiting exoplanets. I searched exoplanet parameter space to locate the maximal effect and derived a criterion that predicts which atmospheres produce detectable refracted light signatures.
My consideration of exoplanetary refraction also included a parallel study of Saturn's atmosphere. I developed a novel method to measure atmospheric refractivity from distorted images of the Sun. I used this method to infer Saturn's atmospheric structure for more than a dozen Saturn solar occultations and to identify seasonal variations in Saturn's stratospheric temperature.
Lastly, I obtained ground-based observations of the long-period transiting exoplanet Kepler-421b to refine its transit ephemeris. Without accurate transit ephemerides, long-period exoplanet characterization with large space-based observatories cannot occur. My unique observations represent the first step toward ensuring that long-period exoplanets are characterized in the near future.
In summary, this dissertation lays the foundation for investigations of cold giant exoplanets, which exist in an almost entirely unexplored regime of exoplanetary science. Using Saturn to provide context and motivation, I began confronting the challenges facing this new discipline of exoplanetary science.
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The influence of optics, peripheral refraction and posture on refractive error developmentHartwig, Andreas January 2012 (has links)
The aim of the present project was to analyse the link between peripheral posture, optics, optics and refractive error progression. Preliminary studies were conducted to ensure that peripheral aberrometry is valid for further analysis. The repeatability of the IRX-3 for peripheral aberrometry was asgood as for central measurements and the recalculation of elliptical pupils did not seem to be necessary for measurements up to 20 degrees eccentricity. Higher order aberration measurements werecomparable to other studies. Eye and head movements as well as working distance did not differ significantly between myopes and non-myopes. However, there was some evidence, that forward bending of the head during reading increases in association with higher refractive error progression rates. The link between central higher order aberrations and refractive error development was analysed by comparing higher order aberrations between isometropes and anisometropes. This analysisdid not show any significant association of higher order aberrations on the development, as no major differences were found between the two groups. For central vision, changes in biometric parameters during accommodation were analysed. It was found that biometric parameters change similarly in myopes and non-myopes. Peripheral accommodation was found to differ between myopes and emmetropes indicating that there might be an influence of peripheral refraction on myopisation. However, associationbetween peripheral refraction or peripheral aberrations and refractive error progression were not significant. The reason for this observation might be the low refractive error progression (0.04± 0.29 D in myopes and -0.12 ± 0.38 D in emmetropes) during one year in the study population.
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Marine seismic studies near Newport, OregonErickson, Barrett H. 08 August 1966 (has links)
In July 1964 three seismic refraction profiles were recorded
over Stonewall Bank (44°32'N, 124°24'W) to determine gross sub-bottom
geological structure to depths of thousands of feet. In August
1964 a continuous seismic reflection profiler was used to document
shallow geological structure within the rocks forming the Bank.
Stonewall Bank is composed of eastward dipping Pliocene siltstones
which emerge westward from beneath unconsolidated Quaternary
sediments. These siltstones form gentle dip slopes on the
Bank's ea-stern flank but rougher topography is found on the top and
western flank where the bedding planes intersect the sea floor at
greater angles. Refraction data from this study indicate the siltstones
thicken southward by 5000 feet over a six mile distance which
accounts for almost all of the thickness change in the measured section.
A deeper layer, 5000 feet thick, which appears to be Miocene
may be exposed west of the Bank beneath the sediments. The base
of this deeper layer has a southerly dip component of about six degrees
and lies 12, 000 feet below the southern end of the Bank.
Although this was the deepest interface encountered, the underlying
material is not believed to be basement. / Graduation date: 1967
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The refractive effects of laser propagation through the ocean and within the oceanXiradakis, Pavlos. January 2009 (has links) (PDF)
Thesis (M.S. in Physics)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Walters, Donald. Second Reader: Borden, Brett. "December 2009." Description based on title screen as viewed on January 27, 2010. Author(s) subject terms: Ocean waves, Laser Scattering, Absorption, Refraction. Includes bibliographical references (p. 55). Also available in print.
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Evaluation of EM propagation models using data from Wallops Island Experiment (2000) /Moys, Andrew J. January 2003 (has links) (PDF)
Thesis (M.S. in Meteorology)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Kenneth L. Davidson, Wendell A. Nuss. Includes bibliographical references (p. 137-139). Also available online.
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Wave propagation over complex bathymetry /Ray, Timothy Allen. January 2003 (has links) (PDF)
Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Thomas H.C. Herbers, Edward B. Thornton. Includes bibliographical references (p. 37). Also available online.
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A system for measuring eye focus time among objects between two and eight feet from the viewerRisseeuw, Dean Philipp 08 1900 (has links)
No description available.
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