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 8 of 8 for “"Presolar"”.
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Correlated NanoSIMS, TEM, and XANES Studies of Presolar Grains
… to describe the correlated study of individual presolar grains via Nano-scale Secondary Ion Mass Spectrometry (NanoSIMS), Transmission Electron Microscopy (TEM), and Scanning Transmission X-ray Microscopy (STXM) utilizing X-ray Absorption Near Edge Structure (XANES), with a focus on connecting …
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Multi-element isotopic analyses of presolar graphite grains from the Orgueil meteorite
… and implications of the isotopic analyses of presolar graphite grains from the primitive carbonaceous chondrite, Orgueil. Graphite grains from low- and high-density fractions were analyzed for C, N, O, Si, Al-Mg, K, Ca, and Ti isotopes. These analyses indicate that isotopic properties are …
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Microanalytical Investigations of Presolar SiC Grains as Probes of Condensation Conditions in Astrophysical Environments
This thesis reports the microanalysis of sixteen presolar SiC grains that are thought to have condensed in several different types of astrophysical environments, including asymptotic giant branch: AGB) stars, J stars, born-again AGB stars, and Type II supernovae: SNe). The isotopic compositions and …
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Isotopic and Elemental Compositions of Stardust and Protosolar Dust Grains in Primitive Meteorites
… of the isotopic and elemental analyses of presolar silicate grains from the primitive chondrites, Acfer 094, SAH 97096, and ALHA77307. Oxygen-anomalous, C-anomalous, and N-anomalous grains were identified by O, C, and N isotopic imaging, respectively, using the NanoSIMS 50. Subsequently, …
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Complex molecules, grain chemistry, and the possible detection of interstellar glycine
… interstellar glycine could shed light on the presolar nebular chemistry and its possible role in seeding newly formed planets with the building blocks of living organisms. This thesis presents the results of the most sophisticated search to date for interstellar glycine.
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Electron beam characterization of carbon nanostructures
… carbon cores found in a subset of graphitic presolar stardust. Electron diffraction data from these cores indicates they are comprised primarily of unlayered graphene sheets. Comparison to simulations indicates that these sheets are more triangular than equant, and thus likely the result of …
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Morning light : the secret history of the Tagish Lake Fireball
… any extraterrestrial sample, and an abundance of presolar grains. Rich in extraterrestrial organic compounds and containing distinct hollow organic globules, the primitive meteorite has brought a mini revolution to the field of meteoritics. It may help us understand the beginnings of the solar …
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A study of nitrogen isotopic systematics in lunar soils and breccias
… prior to breccia consolidation. No evidence of presolar grains could be identified in A79035, although there is some evidence for amorphous carbon. This may also be associated with the presence of fine-grained metallic iron as a significant proportion of this in lunar soils is believed to …