Temperature effect on carbon biomass in soils from tropical and temperate regions.

Quatro solos de varias origens, (clima tropical e temperado), receberam glucose marcada com "C, na proporcao de 1mgde C.g4 de solos e foram incubados a 15oC e a 35oC com o objetivo de determinar o efeito da temperatura sobre a reciclagem do carbono organico e da biomassa microbiana do solo. O efeito da temperatura na biomassa e na taxa de mineralizacao foi mais evidente a 35oC de incubacao. A 35oC, os solos Woburn e Pegwell, da regiao temperada, apresentaram uma taxa de mineralizacao maior do que a dos solos de Janauba e Capinopolis, de regiao tropical. A taxa de respiracao especifica da biomassa formada pela adicao da glucose e da biomassa antiga demonstrou comportamento diferencial entre solos. A 15oC a reciclagem do carbono foi de 207, 225, 115 e 141 dias para Janauba, Capinopolis, Woburn e Pegwell, respectivamente. A 35oC, foi de 92, 69, 69 e 33 dias para os mesmos solos. O 14C residual foi maior a 35oC. A quantidade de biomassa final a 15oC e a 35oC foi correlacionada com o teor de carbono inicial do solo. Houve uma media de 31 e 8 mg de biomassa C.g4 de carbono organico, respectivamente a 15oC e a 35oC. O teor de carbono inicial foi um fator importante para explicar a taxa de mineralizacao a 35oC

Effects of strong magnetic fields on the population of hyperon stars

In this contribution we study the effects of strong magnetic fields on the particle population of neutron stars with hyperon degrees of freedom in their composition. The star matter is described by a multi-component model with parameterized baryon-meson interaction couplings. We study the magnetic effects on the equation of state (EoS) due to the Landau quantization, assuming a density dependent static magnetic field that reaches about $10^{19}\,G$ in the center of the star. The Tolman-Oppenheimer-Volkoff equations are solved in order to understand the dependence of the mass-radius relation and hyperon population on the magnetic field intensity assuming different interaction coupling schemes.Comment: Prepared for conference STARS2013 - 2nd Caibbean Symposium on Cosmology, Gravitaion, Nuclear and Astroparticle Physics / SMFNS2013 - 3rd International Symposium on Strong Electromagnetic Fields and Neutron Star

Meson decay in the Fock-Tani Formalism

The Fock-Tani formalism is a first principle method to obtain effective interactions from microscopic Hamiltonians. Usually this formalism was applied to scattering, here we introduced it to calculate partial decay widths for mesons.Comment: Presented at HADRON05 XI. "International Conference on Hadron Spectroscopy" Rio de Janeiro, Brazil, August 21 to 26, 200

Glueball-glueball scattering in a constituent gluon model

In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock-Tani formalism. In the present work we consider two possibilities for $0^{++}$: (i) as a pure $s\bar{s}$ and calculate, in the context of a quark interchange picture, the cross-section; (ii) as a glueball where a new calculation for this cross-section is made, in the context of the constituent gluon model, with gluon interchange.Comment: Proceedings of the International Workshop IX Hadron Physics and VII Relativistic Aspects of Nuclear Physics (HADRON-RANP 2004