O uso da força no Direito Internacional = Use of force in Public International Law

Versão online da Revista Brasileira de Estudos Políticos, Belo Horizonte, nº 107, pp. 149-200, jul./dez.2013

Experimental study of proton induced nuclear reactions in 6,7 Li

This work presents the results of the experimental study of proton induced nuclear reactions in lithium, namely the 7Li(p,α) 4He, 6Li(p,α) 3He and 7Li(p,p)7Li reactions. The amount of 7Li and 6Li identified as primordial and observed in very old stars of the Milky Way galactic halo strongly deviates from the predictions of primordial nucleosynthesis and stellar evolution models which depend, among other factors, on the cross sections of reactions like 7Li(p,α) 4He and 6Li(p,α) 3He. These discrepancies have triggered a large amount of research in the fields of stellar evolution, cosmology, pre-galactic evolution and low energy nuclear reactions. Focusing on nuclear reactions, this work has measured the 7Li(p,α) 4He and 6Li(p,α) 3He reactions cross sections (expressed in terms of the astrophysical S -factor) with higher accuracy, and the electron screening effects in these reactions for different environments (insulators and metallic targets). The 7Li(p,α) 4He angular distributions were also measured. These measurementstook place in two laboratory facilities, in the framework of the LUNA (Laboratory for Undergroud Nuclear Astrophysics) international collaboration, namely the Laboratorio ´ de Feixe de Ioes ˜ in ITN (Instituto Tecnologico ´ e Nuclear) Sacavem, ´ Portugal, and the Dynamitron-TandemLaboratorium in Ruhr-Universitat¨ Bochum, Germany. The ITN target chamber was modified to measure these nuclear reactions, with the design and construction of new components, the addition of one turbomolecular pump and a cold finger. The 7Li(p,α) 4He and 6Li(p,α) 3He reactions were measured concurrently with seven and four targets, respectively. These targets were produced in order to obtain adequate and stable lithium depth profiles. In metallic environments, the measured electron screening potential energies are much higher than the predictions of atomic-physics models. The Debye screening model applied to the metallic conduction electrons is able to explain these high values. It is a simple model, but also very robust. Concerning primordial nucleosynthesis and stellar evolution models, these results are very important as they show that laboratory measurements are well controlled, and the model inputs from these cross sections are therefore correct. In this work the 7Li(p,p)7Li differential cross section was also measured, which is useful to describe the 7Li(p,α) 4He entrance channel.

Derecho administrativo comunitario

The globalization and the need for countries to unite under regional organizations fostered the emergency of a Communitary law. This isa law made bysupranational institutions capable of submitting States toa single legal order. Thistransforms administrative law on international administrative law that overflows the national legal system. This phenomenon was felt on Colombia given the current development of the Andean Integration System

Surrogacy in Portugal

Surrogacy is the arrangement made by at least three people, in order for a surrogate or gestational mother to carry a pregnancy for the two intended parents, with the objective of the former party relinquishing all rights to the child, once the child is born. As it has only been in recent years that that same reproductive method has begun to be commonly accepted due to certain modern scientific developments that thus diminished ethical and moral negative stances, there is still an unsettling legal void (both at a national and international level) in regards to such subsidiary form of reproduction. As such, some countries have not only left their citizens with no choice but to travel abroad in order to enter a surrogacy arrangement (leading to private international law issues on establishing parenthood and nationality of the born child) or to resort to surrogacy within black market conditions. Unfortunately, one of those countries is Portugal as it has been considered, both by its political parties and experts in the area, and by its citizens as not dealing adequately with such theme and thus being poorly equipped to deal with surrogacy, at both a legal and social level. The present paper attempts to analyse Portugal’s current legal perspective by looking at the present efforts being made to contradict the current situation, and thus outline altruistic gestational surrogacy’s tangible future within such nation. In order to also become aware of possible improvements specifically regarding to the full protection of human rights and human dignity as a whole, the United Kingdom’s legal standpoint in relation to surrogacy was also studied. Via direct comparison of both social and legal perspectives, a new approach to altruistic surrogacy is thus proposed with view to suggest a harmonious solution for countries that have at least recognized that the present issue deserves to be duly noticed and that altruistic gestational surrogacy may exist in order to grant protection of human dignity and not to place it in check.