152,478 research outputs found
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
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
Are Domain Names Property? The sex.com Controversy
Do domain names constitute tangible property? Since domain names may be purchased or transferred, the answer at first glance would appear to be yes . Congress has also dictated that domain names corresponding closely to existing trademarks may be considered tangible property under certain circumstances. However, a recent case involving the lurid and lucrative domain name sex.com has determined otherwise. This iBrief examines the impact of characterizing domain names as tangible or intangible property on the causes of action available for domain name litigation
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