195 research outputs found
Heteroquelia em Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidae) na Ărea de Proteção Ambiental (APA) do Delta do Parnaiba.
ConsideraçÔes a respeito do tamanho da maturação em Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidae) na Ărea de Proteçao Ambiental (APA) do Delta do ParnaĂba.
Heteroquelia em Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidae) na Ărea de Proteção Ambiental (APA) do Delta do Parnaiba.
Coeficiente de transmissão de radiação solar em Manaus em junho ()
Global and diffuse solar radiation measurements, obtained by means of an Eppley pyrheliometer, were made two days in June 1975, one was clear day, (June, 11), and the other an overcast day (June, 19). The mean transmission coefficient for global and direct radiation were determined to be 0,81 and 0,70 respectively. The data on daily global solar radiation indicated that the values measured with the actinograph under estimate the real solar radiation values reaching the ground.Medidas de radiação global e difusa foram realizadas com um pirelhiometro Eppley em dois dias caracterĂsticos, um limpo e outro nublado em junho de 1975. Os valores mĂ©dios para os coeficientes de transmissĂŁo para mĂ©dias global e direta foram 0,81 e 0,70 respectivamente no dia 11/06/75. Os dados de radiação global diĂĄria indicam que os resultados obtidos com actinĂłgrafos instalados na ĂĄrea subestimam o total de energia realmente disponĂvel ao nĂvel do solo
Structure of Be probed via secondary beam reactions
The low-lying level structure of the unbound neutron-rich nucleus Be
has been investigated via breakup on a carbon target of secondary beams of
B at 35 MeV/nucleon. The coincident detection of the beam velocity
Be fragments and neutrons permitted the invariant mass of the
Be+ and Be++ systems to be reconstructed. In the case of
the breakup of B, a very narrow structure at threshold was observed in
the Be+ channel. Contrary to earlier stable beam fragmentation
studies which identified this as a strongly interacting -wave virtual state
in Be, analysis here of the Be++ events demonstrated that
this was an artifact resulting from the sequential-decay of the
Be(2) state. Single-proton removal from B was found to
populate a broad low-lying structure some 0.70 MeV above the neutron-decay
threshold in addition to a less prominent feature at around 2.4 MeV. Based on
the selectivity of the reaction and a comparison with (0-3)
shell-model calculations, the low-lying structure is concluded to most probably
arise from closely spaced J=1/2 and 5/2 resonances
(E=0.400.03 and 0.85 MeV), whilst the broad
higher-lying feature is a second 5/2 level (E=2.350.14 MeV). Taken
in conjunction with earlier studies, it would appear that the lowest 1/2
and 1/2 levels lie relatively close together below 1 MeV.Comment: 14 pages, 13 figures, 2 tables. Accepted for publication in Physical
Review
Modelo digital para a Restinga e Paleoilha da Marambaia, Rio de Janeiro.
Foi criado para a Marambaia um modelo digital de seu ambiente, com a finalidade de avaliar as diversas situaçÔes ambientais presentes na regiĂŁo. Acha-se representado por um conjunto de sete mapas digitais temĂĄticos constituintes da Base de Dados Georreferenciadas, e por dois mapas digitais classificatĂłrios, correspondentes Ă s avaliaçÔes das ĂĄreas com potencial para testes militares e para investigação cientĂfica. Estes produtos foram desenvolvidos pelo LaboratĂłrio de Geoprocessamento Aplicado da UFRRJ, atravĂ©s do uso da tĂ©cnica de geoprocessamento e mĂ©todos associados do programa SAGA/UFRJ - Sistema de AnĂĄlise Geo Ambiental
The detection of neutron clusters
A new approach to the production and detection of bound neutron clusters is
presented. The technique is based on the breakup of beams of very neutron-rich
nuclei and the subsequent detection of the recoiling proton in a liquid
scintillator. The method has been tested in the breakup of 11Li, 14Be and 15B
beams by a C target. Some 6 events were observed that exhibit the
characteristics of a multineutron cluster liberated in the breakup of 14Be,
most probably in the channel 10Be+4n. The various backgrounds that may mimic
such a signal are discussed in detail.Comment: 11 pages, 12 figures, LPCC 01-1
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