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We report on the growth of bulk samples (composite fibers) of the nominal composition La 0.7 Ce 0.3 MnO 3 (LCMO) manganites (with Curie temperature T C,max ¼ 300 K) by using the laser heated pedestal growth (LHPG) technique. Samples composition was verified through scanning electron microscopy with energy dispersive X-ray (EDX) analysis. The magnetic

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Polycrystalline samples of the Pr doped Yb 1−x PrxBa 2 Cu 3 O 7−δ (i.e. Yb(Pr)-123) system for 0 ≤ x ≤ 1 have been investigated for resistivity ρ and magnetization M as a function of temperature in normal and superconducting states. The gradual decrease in superconducting critical temperature Tc(x) is found to be correlated with the xdependent ratio of resistivity slope (dρ/dT )cc (corresponding to the linear ρ(T ) region) and residual resistivity ρ 0 . In particular, the observed difference of critical Pr concentration where superconductivity is destroyed (xc) in Yb(Pr)-123 (xc ≈ 0.65) and Y(Pr)-123 (xc ≈ 0.55) matches with the difference in the value of Pr concentration where the ratio (dρ/dT )cc /ρ 0 tends to go to zero in them. The M (T ) data of the Yb(Pr)-123 samples show magnetic ordering for x > xc at characteristic temperatures, Tn, that increase with x. Interestingly, the Yb(Pr)-123 sample with Pr content (x = 0.6) near xc reveals several anomalous features like transition from metallic to semiconducting-like ρ(T ), an excessive broadening of the diamagnetic transition and weakening of the M (T ) signal related to antiferromagnetic ordering of Pr ions. These observations can be consistently interpreted by assuming the presence of dynamically fluctuating striped phase in these systems. PACS Number(s): 74.62.Dh, 74.72.Bk

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Resumo: O presente artigo analisa a consolidação da carreira de Engenharia Física no Brasil ao longo das duas primeiras décadas contabilizadas a partir do ano de criação do curso . Foram revisados os antecedentes e as motivações que fomentaram a sua concepção e o direcionamento para uma

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O termo «colonial» desenterra fantasmas relacionados com leituras conexas a memórias, sentimentos de culpa e mágoas ainda incómodas. As narrativas coloniais são sobretudo um louvor à «missão» e à ação colonizadoras, assim como às gentes da metrópole e do território colonial, numa perspetiva de uma «natural» superioridade branca. Este artigo pretende cartografar preconceitos culturais do passado colonial através da análise de narrativas ficcionais sobre Angola e Moçambique, datadas entre os anos 20-60, que permitem um entendimento mais circunstanciado do pensamento e da representação do mundo colonial português do século XX.