The application of the Shpol'skii effect in low temperature luminescence spectrometry

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Nagel scaling and relaxation in the kinetic Ising model on a n-isotopic chain

The kinetic Ising model on a n-isotopic chain is considered in the framework of Glauber dynamics. The chain is composed of N segments with n sites, each one occupied by a different isotope. Due to the isotopic mass difference, the n spins in each segment have different relaxation times in the absence of the interactions, and consequently the dynamics of the system is governed by multiple relaxation mechanisms. The solution is obtained in closed form for arbitrary n, by reducing the problem to a set of n coupled equations, and it is shown rigorously that the critical exponent z is equal to 2. Explicit results are obtained numerically for any temperature and it is also shown that the dynamic susceptibility satisfies the new scaling (Nagel scaling) proposed for glass-forming liquids. This is in agreement with our recent results (L. L. Goncalves, M. Lopez de Haro, J. Taguena-Martinez and R. B. Stinchcombe, Phys. Rev. Lett. 84, 1507 (2000)), which relate this new scaling function to multiple relaxation processes.Comment: 4 pages, 2 figures, presented at Ising Centennial Colloquium, to be published in the Proceedings (Brazilian Journal of Physics.

Conhecimentos, atitudes e praticas de enfermeiros e medicos sobre a transmissao vertical da hepatite B

OBJECTIVE: to identify knowledge, attitudes and practices of physicians and nurses of the Family Health Strategy and a maternity hospital unit about vertical transmission of hepatitis B. METHOD: a cross-sectional study with a self-administered questionnaire applied to professionals. The data were analyzed according to professional category and site of action, whose differences were tested by χ2 and significanceOBJETIVO: identificar los conocimientos, actitudes y prácticas de los médicos y enfermeros de la Estrategia Salud de la Familia de un hospital de maternidad sobre la transmisión vertical de la hepatitis B. MÉTODO: estudio transversal con un cuestionario autoadministrado aplicado a los profesionales. Los datos fueron analizados de acuerdo con la categoría profesional y el sitio de acción, cuyas diferencias fueron analizadas a través de χ2 y significanciaOBJETIVO: identificar conhecimentos, atitudes e práticas de médicos e enfermeiros da Estratégia Saúde da Família e de uma maternidade sobre a transmissão vertical da hepatite B. MÉTODO: estudo transversal, com questionário autopreenchível aplicado aos profissionais. Os dados foram analisados conforme categoria profissional e local de atuação, cujas diferenças foram testadas pelo χ2 e significânci

A classification of special 2-fold coverings

Starting with an O(2)-principal fibration over a closed oriented surface F_g, g>=1, a 2-fold covering of the total space is said to be special when the monodromy sends the fiber SO(2) = S^1 to the nontrivial element of Z_2. Adapting D Jonhson's method [Spin structures and quadratic forms on surfaces, J London Math Soc, 22 (1980) 365-373] we define an action of Sp(Z_2,2g), the group of symplectic isomorphisms of (H_1(F_g;Z_2),.), on the set of special 2-fold coverings which has two orbits, one with 2^{g-1}(2^g+1) elements and one with 2^{g-1}(2^g-1) elements. These two orbits are obtained by considering Arf-invariants and some congruence of the derived matrices coming from Fox Calculus. Sp(Z_2,2g) is described as the union of conjugacy classes of two subgroups, each of them fixing a special 2-fold covering. Generators of these two subgroups are made explicit.Comment: This is the version published by Geometry & Topology Monographs on 29 April 200