https://repositorio.ufu.br/handle/123456789/18792 Tue, 11 Aug 2026 14:25:25 GMT 2026-08-11T14:25:25Z https://repositorio.ufu.br/handle/123456789/49121 Title: Eletrodos de grafeno quimicamente modificados com corantes biocompatíveis e sua aplicação em biossensores de diagnóstico Thu, 29 Jan 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49121 2026-01-29T00:00:00Z https://repositorio.ufu.br/handle/123456789/49022 Title: Otimização da qualidade da imagem de SPECT utilizando o Lutécio-177 utilizando simulações Monte Carlo Abstract: This undergraduate thesis aimed to evaluate the influence of collimator selection and energy window choice on the quality of SPECT images obtained with the radionuclide ( 𝐿𝑢 177 ), using Monte Carlo simulations and iterative reconstruction. Three collimators (LEGP, LEHR, and MEGP) and three energy window configurations were compared: 𝐽1 (±10% around 113 keV), 𝐽2 (±10% around 208 keV), and 𝐽3 (integration of both). Contrast, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were analyzed for each configuration. The results showed that the J_2 window provided superior performance in terms of contrast, contour definition, and CNR, while the LEHR collimator stood out as the most effective, combining high spatial resolution with low noise levels. These findings reinforce the importance of carefully selecting acquisition parameters to optimize SPECT image quality with ( 𝐿𝑢 177 ). Nevertheless, further studies incorporating scatter and attenuation correction techniques, as well as experimental validation, are required to advance quantitative imaging and improve therapeutic planning in nuclear medicine. Tue, 16 Sep 2025 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/49022 2025-09-16T00:00:00Z https://repositorio.ufu.br/handle/123456789/48888 Title: Análise da presença de radiações ionizantes em materiais diários utilizando câmara de nuvens Abstract: The cloud chamber is a particle detector that enables the direct visualization, with the naked eye, of the tracks left by ionizing radiation. The objective of this work was the optimization of a thermoelectric cloud chamber prototype already described in the literature, aiming to improve its robustness, safety, and thermal efficiency, for its subsequent application in the qualitative analysis of radioactivity in everyday materials. A visual analysis was carried out on several sources, such as a 232Th electrode, an old alarm clock hand containing 226Ra, uranium glass, and 222Rn. The chamber demonstrated a high capacity to distinguish the visual signatures of α particles (short and dense tracks) and β particles (long and erratic tracks), in addition to background radiation. The analysis allowed the visual demonstration of complex physical concepts, such as secular equilibrium and radioactive decay. Its optimization proved effective for teaching and research in the field of nuclear physics Fri, 06 Feb 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48888 2026-02-06T00:00:00Z https://repositorio.ufu.br/handle/123456789/48290 Title: O uso de contraste na Tomografia Computadorizada Wed, 17 Dec 2025 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48290 2025-12-17T00:00:00Z