993 resultados para 108-661A


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Stable isotopic data from benthic foraminifera indicate the occurrence of at least three deepwater masses in the late Maastrichtian ocean. Given mean oceanic d18Ow of -1.0 per mil, the temperature of the coolest intermediate-depth waters was 5°-7°C, that of the deepest waters was 10°C, and that of the warmest intermediate waters was 13°-15°C. The cool intermediate-depth water mass probably originated in the high-latitude Southern Ocean. The deepest waters originated at least partly in the northern Atlantic. The source region for the warmest intermediate-depth water mass is unknown. Although much of the late Maastrichtian deep water was probably preconditioned for winter sinking by low- or middle-latitude evaporation, no more than ~11% of late Maastrichtian deep water could have been directly actuated by low-latitude sea surface evaporation. At least in the southern Atlantic and Indian Oceans, heat transport by upwelling of deep water was not the primary cause of mild sea surface and coastal temperatures.

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During the present study the Ivory Coast microtektite layer was found in cores from five equatorial Atlantic sites, bringing the total number of Ivory Coast microtektite-bearing cores to eleven. The strewn field appears to be restricted to between 9°N and 12°S latitude. There is a general increase in the concentration of microtektites towards the Bosumtwi crater, which is generally thought to be the source of the Ivory Coast tektites. The relationship between the onset of the Jaramillo subchron and the Ivory Coast microtektite layer has been investigated in six cores. A plot of the difference in depth between the base of the Jaramillo subchron and the microtektite layer versus sediment accumulation rate was used to determine the average post-depositional remanent magnetization (PDRM) acquisition depth and the age difference between the onset of the Jaramillo subchron and the deposition of the microtektites. Assuming that the PDRM acquisition depth does not vary with sediment accumulation rate, we find that the average PDRM acquisition depth is 7 cm and that the microtektites were deposited approximately 8 ky after the onset of the Jaramillo subchron. This indicates that the impact responsible for the Ivory Coast tektites and microtektites could not be causally related to the geomagnetic reversal at the base of the Jaramillo subchron.

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Strontium isotopic compositions of acetic acid (HOAc) leachate fractions of eight manganese oxide deposits from the modern seafloor, and of twenty-one buried manganese nodules from Cretaceous to Recent sediments in DSDP/ODP cores were measured. ratios of HOAc leachates in all modern seafloor manganese oxides of various origins are identical with present seawater. The ratios of the HOAc leachates of buried nodules from DSDP/ODP cores are significantly lower than those of nodules from the modern seafloor and are mostly identical with coeval seawater values estimated from the age of associated sediments. It is suggested that the buried nodules in DSDP/ODP cores are not artifacts transported from the present seafloor during the drilling process, but are in situ fossil deposits from the past deep-sea floor during Cretaceous to Quaternary periods. The formation of deep-sea fossil nodules prior to the formation of Antarctic Bottom Water (AABW) indicates that the circulation of oxygenated deep seawaters have activately deposited manganese oxides since the Eocene Epoch, or earlier.

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Contenido: Un hombre y un mundo sin sentido / Ocostavio N. Derisi – Existencia y cultura / Alberto Caturelli – La cuestión “De aeternitate mundi” : posiciones doctrinales / Omar Argerami – Educación y trascendencia / J. E. Bolzán – Notas y comentarios -- Bibliografía

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Os Constituintes consideram que é dever do Estado proteger as crianças. João de Deus Antunes (PDT-RS) diz que o menor vai ser um dos mais privilegiados na nova carta constitucional. Pontos fundamentais dos direitos da criança: direito à vida, à saúde, à alimentação e à educação; diireito à assistência social, mesmo que os pais não contribuam para a previdência; proteção aos menores carentes e infratores; legislação especial sobre o trabalho do menor. Wilma Maia (PDS-RN) afirma que a nova Constituição tem de fazer cumprir os princípios de proteção dos menores, a começar pela educação, baseada um uma nova concepção, que ensine as crianças seus direitos e seus deveres. Robson Marinho (PMDB-SP) considera que no texto da nova Constituição estão assegurados os direitos básicos da criança. Mário Covas (PMDB-SP) acompanha as reuniões da Comissão de Sistematização e acredita na compatibilização dos diferentes textos feitos pelas distintas correntes políticas na Assembleia Nacional Constituinte (ANC). Artur da Távola (PMDB-RJ) aprova a permanência dos pontos mantidos no substitutivo da Comissão de Comunicação, especialmente as quatro finalidades da comunicação: cultural, educativa, regionalização da produção cultural e divulgação da cultura nacional. Bernardo Cabral (PMDB-AM), Relator da Comissão de Sistematização, faz balanço dos trabalhos e dos prazos. Na sessão O Povo Pergunta, cidadão quer saber o que está sendo decidido quanto a doação de órgãos. Uldurico Pinto (PMDB-BA) responde que todo cidadão é um doador em potencial, salvo aqueles que a família não permitir. Bernardo Cabral; João de Deus Antunes; Wilma Maia; Robson Marinho; Mário Covas; Fernando Henrique Cardoso; Arthur da Távola; Ulsorico Pinto;

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In September 2002, side scan sonar was used to image a portion of the sea floor in the northern OCNMS and was mosaiced at 1-meter pixel resolution using 100 kHz data collected at 300-meter range scale. Video from a remotely-operated vehicle (ROV), bathymetry data, sedimentary samples, and sonar mapping have been integrated to describe geological and biological aspects of habitat and polygon features have been created and attributed with a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999). The data can be used with geographic information system (GIS) software for display, query, and analysis. Textural analysis of the sonar images provided a relatively automated method for delineating substrate into three broad classes representing soft, mixed sediment, and hard bottom. Microhabitat and presence of certain biologic attributes were also populated into the polygon features, but strictly limited to areas where video groundtruthing occurred. Further groundtruthing work in specific areas would improve confidence in the classified habitat map. (PDF contains 22 pages.)

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Votação do projeto de Constituição Federal. Mobilização de empresários brasileiros junto à Assembleia Nacional Constituinte. Denúncia da existência de lobby de empresas multinacionais junto a constituintes. Negociação de Líderes em torno da inclusão na pauta de itens considerados polêmicos.

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Within the framework of the dinuclear system (DNS) model, production cross sections of new superheavy nuclei with charged numbers Z=108-114 are analyzed systematically. Possible combinations based on the actinide nuclides U-238, Pu-244, and Cm-248,Cm-250 with the optimal excitation energies and evaporation channels are pointed out to synthesize new isotopes that lie between the nuclides produced in the cold fusion reactions and the Ca-48-induced fusion reactions experimentally, which are feasible to be constructed experimentally. It is found that the production cross sections of superheavy nuclei decrease drastically with the charged numbers of compound nuclei. Larger mass asymmetries of the entrance channels enhance the cross sections in 2n-5n channels.