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 8023 for “"Ray"”.
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Gamma-Ray Observations of X-ray Binaries
<p>The detection of GeV/TeV emission from X-ray binaries (XRBs) has established a new class of high-energy (HE, >0.1 GeV) and very-high-energy (VHE, >100 GeV) gamma-ray emitters. XRBs are formed by a compact object, either a neutron star or a black hole, and by an optical companion star. Some XRBs …
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Ray tracing large distributed datasets using ray caches
… develop an in-situ visualization technique using ray tracing that employs ray caches to reduce communication overhead. Ray caches attempt to replace a communication operation with a less expensive cache search operation. A prototype implemented on Sharcnet shows ray caching can signi cantly …
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Optical & X-ray Studies of Ultraluminous X-ray Sources
Ultraluminous X-ray Sources (ULXs) are point like X-ray sources situated external to the nucleus of their host galaxy, with inferred X-ray luminosities in excess of 10^{39} erg s^{−1} . Although first observed ∼ 30 years ago, these sources are yet to be fully understood. Some have suggested that …
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Optical and gamma-ray study of gamma-ray binaries
Gamma-ray binary stars are intriguing interacting stellar systems that exhibit emission across the whole electromagnetic spectrum. This thesis is focused on optical and gamma-ray emission of gamma-ray binary stars (GRBis). I have performed radial velocity measurements of 1FGL J1018.6-5856 to derive …
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X-ray spectroscopy of low-mass X-ray binaries
I present high-resolution X-ray grating spectroscopy of neutron stars in low-mass X-ray binaries (LMXBs) using instruments onboard the Chandra X-ray Observatory and the X-ray Multi-Mirror Mission (XMM-Newton). The first part of this thesis concentrates on results from the subset of LMXBs with …
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Fisher Information in X-ray/Gamma-ray Imaging Instrumentation Design
Signal formation in a photon-counting x-ray/gamma-ray imaging detector is a complex process resulting in detector signals governed by multiple random effects. Recovering maximum possible information about event attributes of interest requires a systematic collection of calibration data and analysis …
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Spherical ray-tracing
… fit into spherical coordinates. When tracing rays through naturally spherical domains (for example, for visualization), converting to Cartesian coordinates introduces aberrations. Therefore, we seek an algorithm to natively cast rays through spherical coordinates, and without performing …
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X-ray spectroscopy of neutron star low-mass X-ray binaries
… of topics relating to neutron star lowmass X-ray binaries (LMXBs) and utilize spectral information from X-ray observations to further our understanding of these sources. First, I give an overview of important X- ray astrophysics relevant to the work I present in subsequent chapters, as well as …
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X-Ray Machine Tests and X-Ray Experiments for Undergraduate Physics Laboratories
… University Physics Department acquired an X-ray machine. There was a need to convert this device to an educational tool so it could be used on an undergraduate level. Procedure. First, the machine was tested to find its range limits. Secondly, numerous experiments were designed to use the …
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Designing a nanoscale x-ray source: towards single molecule x-ray scattering
… the design and construction of a femtosecond X-ray source based on high harmonic generation in an argon filled hollow capillary waveguide. The system has demonstrated excellent efficiency at generating harmonics in the range 20-50 eV and is tuneable by exploiting the ionization-induced …
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X-ray and optical properties of X-ray luminous active galactic nuclei
… et al. (1962) discovered a diffuse cosmic X-ray background with rocket experiments when they searched for lunar X-ray emission. Later satellite missions found a spectral peak in the cosmic X-ray background at ~30 keV. Imaging X-ray satellites such as ROSAT (1990-1999) were able to resolve up …
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The Ultraviolet-Ray and X-Ray Response of The Desmid, Micrasterias Decemdentata
Made available in DSpace on 2014-12-11T22:22:17Z (GMT). No. of bitstreams: 1 7212195.pdf: 3930829 bytes, checksum: 1fb1be79012bfcb3ec997575a13147a3 (MD5) Previous issue date: 1971
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Magnetic X-ray Reflectivity
… multilayer systems via magnetic soft and hard x-ray reflectivity. The focus here is on 3d transition metals, which are used mainly for development of numerous noval magnetic devices, that are both technologically and scientifically interesting. Complementary to Neutron diffraction, which is the …
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Coherent X -Ray Diffraction
… derived from the kinematical formulation for x-ray diffraction and from the temporal and spatial coherence of radiation. The antiphase domain structure of Cu 3Au is described, along with the associated reciprocal-space structure which is measured by CXD. CXD measurements place relatively …
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Coherent x-ray diffraction
Submitted by Meng Tao (mengtao2@illinois.edu) on 2012-10-26T22:51:05Z No. of bitstreams: 1 pitney_John.pdf: 12626202 bytes, checksum: 0a4edb5141b145027d659f789e1e8679 (MD5)
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