Navegando por Palavras-chave "energy transfer"

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    Study of color centers produced in thulium doped YLF crystals irradiated by electron beam and femtosecond laser pulses
    (Elsevier B.V., 2007-02-15) Courrol, Lilia C.; Ranieri, Izilda M.; Baldochi, Sonia Licia; Samad, Ricardo E.; Freitas, Anderson Z. de; Gomes, Laercio; Vieira, Nilson D.; Universidade Federal de São Paulo (UNIFESP); IPEN
    In this work, we report the influence of the presence of photochromic and color centers in the photobleaching of thulium ions blue emission in YLF (YLiF4) crystals doped with 1 mol% Tm (3+). the samples were irradiated at room temperature both with electron beam and high intensity ultrashort pulses from a Ti:Sapphire CPA laser system. in both irradiations the production of photochromic and color centers was observed via the absorption bands in the UV and visible ranges. Pure LiF and pure and oxygen doped YLF crystals were used to identify the color centers produced and their optical properties. From a phenomenological model it was possible to study the interaction between color centers and thulium ions, and their effect in photobleaching and photodarkening behaviors. Finally, the blue up laser level population was computed using a rate equation analysis. (c) 2006 Elsevier B.V. All rights reserved.
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    Urea hydrogen peroxide determination in whole blood using europium tetracycline probe
    (Elsevier B.V., 2006-08-01) Courrol, Lilia C.; Bellini, Maria H.; Tarelho, Luiz V. G.; Silva, Flavia R. O.; Mansano, Ronaldo D.; Gomes, Laercio; Vieira, Nilson D.; Shor, Nestor; FATEC SP; IPEN; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    We introduce the use of a lanthanide complex, tetracycline-europium, for the clinical diagnosis of urea hydrogen peroxide in human whole blood. the values obtained agree with the urea concentration variation verified in 49 patients, including 12 predialysis, 12 peritoneal, and 15 dialysis subjects, and 10 controls. This method is noninvasive and can help in the identification of renal and cardiac diseases. (c) 2006 Elsevier Inc. All rights reserved.