Marine radiocarbon reservoir effect of coastal waters off Cape Verde archipelago

Quantification of the marine radiocarbon reservoir effect (Delta R) is essential in order to calibrate conventional C-14 dates from marine shell samples with reliability. Delta R also provides information concerning the intensity of coastal upwelling in marine regions influenced by this phenomenon. C-14 ages of closely associated marine samples (mollusk shells) and terrestrial samples (goat bones) from Sao Vicente Island, Cape Verde Archipelago, permitted the first calculation of the marine C-14 reservoir effect in this region. A Delta R weighted mean value of 70 +/- 70 C-14 yr was obtained. This value is in accordance with the previously published oceanographic conditions of the region indicating the existence of a seasonal active upwelling regime

The identification of physical close galaxy pairs

A classification scheme for close pairs of galaxies is proposed. The scheme is motivated by the fact that the majority of apparent close pairs are in fact wide pairs in three-dimensional space. This is demonstrated by means of numerical simulations of random samples of binary galaxies and the scrutiny of the resulting projected and spatial separation distributions. Observational strategies for classifying close pairs according to the scheme are suggested. As a result, physical (i.e., bound and spatially) close pairs are identified.Comment: 16 pages, 5 figures, accepted for publication in The Astronomical Journal, added text corrections on proof

Freelance Articles and Electronic Databases: Who Owns the Copyrights?

There has long been uncertainty as to who owns the rights to digital reproductions of freelance articles. The Supreme Court has recently affirmed that copyrights for the digital reproduction of freelance articles belong to freelance authors, rather than the periodical and electronic media publishers who included the articles in electronic databases. However, in answering this question others, such as the preservation of the historical record and future dealings with freelance writers remain to be answered. The author discusses the recent Supreme Court ruling and offers answers to questions created by it

Physico-mathematical foundations of relativistic cosmology

I briefly present the foundations of relativistic cosmology, which are, General Relativity Theory and the Cosmological Principle. I discuss some relativistic models, namely, "Einstein static universe" and "Friedmann universes". The classical bibliographic references for the relevant tensorial demonstrations are indicated whenever necessary, although the calculations themselves are not shown.Comment: 12 pages, no figure. Portuguese version published by Revista Brasileira de Ensino de Fisica (Brazilian Journal of Physics Teaching) at http://www.sbfisica.org.br/rbef/pdf/353302.pd