Thesis (Ph.D.)--University of Western Australia, 2007.

Thesis (Ph. D.)--Duke University, 2007. / Includes bibliographical references.

Habilitationsschrift--Münster. / Bibliography . [82]-101.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1955. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 90-92).

Thesis (M. Eng.)--Carleton University, 1992. / Also available in electronic format on the Internet.

Academisch proefschrift--Amsterdam. / "Summary": p. 232-234. "Stellingen": [4] p. inserted. "Literatuurlijst": p. 235-240.

Thesis--University of California, Berkeley, 1960. / "UC-34 Physics" -t.p. "TID-4500 (16th Ed.)" -t.p. Includes bibliographical references (p. 110-113).

Habilitationsschrift--Münster. / Bibliography . [82]-101.

abstract: The IceCube Neutrino Observatory has provided the first map of the high energy (~0.01 – 1 PeV) sky in neutrinos. Since neutrinos propagate undeflected, their arrival direction is an important identifier for sources of high energy particle acceleration. Reconstructed arrival directions are consistent with an extragalactic origin, with possibly a galactic component, of the neutrino flux. We present a statistical analysis of positional coincidences of the IceCube neutrinos with known astrophysical objects from several catalogs. For the brightest gamma-ray emitting blazars and for Seyfert galaxies, the numbers of coincidences is consistent with the random, or “null”, distribution. Instead, when considering starburst galaxies with the highest flux in gamma-rays and infrared radiation, up to n = 8 coincidences are found, representing an excess over the ~4 predicted for the null distribution. The probability that this excess is realized in the null case, the p-value, is p = 0.042. This value falls to p = 0.003 for a set of gamma-ray detected starburst galaxies and superbubbles in the galactic neighborhood. Therefore, it is possible that these might account for a subset of IceCube neutrinos. The physical plausibility of such correlation is discussed briefly. / Dissertation/Thesis / Masters Thesis Astrophysics 2015

Made available in DSpace on 2014-06-11T19:30:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-31Bitstream added on 2014-06-13T21:00:47Z : No. of bitstreams: 1 vismara_mvg_me_bauru.pdf: 1607998 bytes, checksum: 8efc51b01e3badc0e6233d3ef3f7d4ab (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Este trabalho teve como objetivo a investigação da interação de radiação gama com três polímeros: o polímero Poli(2-metóxi, 5-(2'-etil-hexilóx)-1,4- fenileno vinileno) (MEH-PPV)n e os polímeros solúveis em água Poly {[2,5-bis(2-(N,N-diethylamino)ethoxy) -1,4 -phenylene]-alt-1,4-phenylene} e o Poly [(2,5-bis (2 - (N,N - diethylammonium bromide) ethoxy) - 1,4 -phenylene) - alt - 1,4-phenylene]. O polímero MEH-PPV foi dissolvido nos solventes orgânicos clorofórmio e bromofórmio, já os outros dois polímeros, em água destilada e solução de HCI 1M. As amostras foram preparadas em várias concentrações e irradiadas com doses que variaram desde 0,01 Gy, sendo que cada amostra foi irradiada com apenas uma dose. Os resultados foram avaliados com técnicas espectroscópicas, sendo elas, espectroscopia de absorção óptica UV-visível e espectroscopia de fluorescência. Foi avaliada a alteração na posição do pico principal de absorção óptica com a dose absorvida pelas amostras. Como resultado principal, observou-se que os polímeros solúveis em água não apresentam alteração espectral após serem irradiados. Não sendo interessante para aplicação dosimétrica. Já para as amostras do polímero MEH-PPV diluídas em bromofórmio apresentaram alta sensibilidade para doses inferiores a 1 Gy, e apresentaram certa linearidade com a dose recebida (fator importante para aplicação dosimétrica). Para as amostras em clorofórmio, não foi observado deslocamento significativo do escpectro de absorção para doses inferiores a 1 Gy. No entanto para doses de 1 Gy à 90 Gy, o comportamento observado pode ser descrito por duas regiões lineares: uma com maior inclinação da reta para doses até cerca 30 Gy, e outro com inclinação da reta menor para doses entre 30 Gy e 90 Gy. O comportamento linear, assim como a inclinação da reta, do deslocamento da posição... / The subject of this work is the investigation of gamma radition interaction with tree polymers: the polymer Poli(2-metóxi, 5-(2'-etil-hexilóx)-1,4- fenileno vinileno) (MEH-PPV)n e os polímeros solúveis em água Poly {[2,5-bis(2-(N,N-diethylamino)ethoxy) -1,4 -phenylene]-alt-1,4-phenylene} e o Poly [(2,5-bis (2 - (N,N - diethylammonium bromide) ethoxy) - 1,4 -phenylene) - alt - 1,4-phenylene]. The MEH-PPV polymer was dissolved in organic solvents, choloroform and bromoform, the other two polymers in distilled water and 1 M aqueous HCI solution. The samples were prepared at various concentrations and irradiated with doses ranging from 0.01 Gy to 90 Gy. The results were evaluated by spectroscopic techniques, which were, UV-visible absorption spectroscopy and fluorescence spectroscopy. They were evaluated the changes in the position of main optical absorption peak with the dose absorbed by the samples. As main result, it was observed that water-soluble polymers did not show spectral change after being irradiated. For dosimetric application this results are not interesting. For the MEH-PPV polymer samples diluted in bromoform presented highly sensitive to doses below 1 Gy, and showed some linearity with the dose received. For samples in chloroform, doses below 1 Gy did not showed significant shift in the absorption spectra. However, the samples irradiated with doses from 1 Gy to 90 Gy, the behavior can be described by two linear regions: one with a higher slope for doses up to about 30 Gy, and another with a lower slope for doses between 30 Gy and 90 Gy. A greater slope to doses up to about 30 Gy, and another with lower slope to doses between 30 and 90 Gy. The linear behavior and the slope of the main peak position is a important factor for dosimetric application. At the same time, a study of stability of the samples was performed. It was observed that the MEH-PPV samples in bromoform... (Complete abstract click electronic access below)