45 resultados para Antenna monopole

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Using a collective potential derived previously on the basis of the generator coordinate method with Skyrme interactions, we obtain values for the compression modulus of Ca-40 which are in good agreement with a recently obtained experimental value. Calculated values for the compression modulus for O-16 are also given. The procedure involved in the derivation of the collective potential is briefly reviewed and discussed.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Photosynthetic induction in leaves of four-month-old Eucalyptus urograndis seedlings and of cuttings obtained from adult trees that were previously dark-adapted was studied by the in vivo and in situ Open Photoacoustic Cell Technique, Results for the gas exchange component of the photoacoustic (PA) signal were interpreted considering that the gas uptake component would have a phase angle nearly opposite to that of the oxygen evolution component. By subtracting the thermal component from the total PA signal, we studied the competition between gas uptake and oxygen evolution during the photosynthetic induction. Seedlings presented a net oxygen evolution prior to cuttings, but cuttings reached a higher steady-state photosynthetic activity. The chlorophyll (Chl) a/b ratio and the Chl fluorescence induction characteristic F-v/F-m were significantly higher for cuttings, while there was no difference between samples in stomata density and leaf thickness. Thus the differences in PA signals of seedlings and cuttings are associated to differences between the photosystem 2 antenna systems of these samples.

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Neste trabalho, as ninfas de Quesada gigas (Olivier) são descritas e ilustradas. Uma chave para o reconhecimento dos cinco ínstares ninfais é também apresentada. Foram analisados exemplares coletados em cafezais dos municípios de São Sebastião do Paraíso, Monte Santo de Minas e Patrimônio (Minas Gerais), Franca e Casa Branca (São Paulo). As amostras encontram-se preservadas em álcool a 80% e depositadas na Coleção Entomológica do Departamento de Fitossanidade da FCAV-UNESP, Câmpus de Jaboticabal. Os caracteres analisados foram: antenas, tecas alares, perna anterior, ápice da tíbia meso e metatorácicas e ápice abdominal do macho/fêmea. Foi adotada uma fórmula para indicar a configuração que é apresentada pelas estruturas presentes no fêmur anterior. Ninfas de Q. gigas de primeiro ínstar apresentam fórmula femoral 2-1-0, de segundo ínstar 2-1-3, de terceiro ínstar 2-1-5, de quarto ínstar 2-1-6 e as de quinto ínstar 2-2-8. O primeiro número refere-se à somatória dos dentes posteriores e dentes acessórios, o segundo ao número de dentes intermediários e o terceiro aos dentes do pente femoral. As estruturas apresentadas pelo fêmur protorácico constituem caracteres morfológicos adequados para a identificação dos ínstares ninfais de cigarras.

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Dirac-like monopoles are studied in three-dimensional Abelian Maxwell and Maxwell-Chern-Simons models. Their scalar nature is highlighted and discussed through a dimensional reduction of four-dimensional electrodynamics with electric and magnetic sources. Some general properties and similarities whether considered in Minkowski or Euclidean space are mentioned. However, by virtue of the structure of the space-time in which they are studied, a number of differences among them occur. Furthermore, we pay attention to some consequences of these objects when they act upon the usual particles. Among other subjects, special attention is given to the study of a Lorentz-violating nonminimal coupling between neutral fermions and the field generated by a monopole alone. In addition, an analogue of the Aharonov-Casher effect is discussed in this framework.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The main target here is to determine the orbit of an artificial satellite, using signals of the GPS constellation and least squares algorithms implemented through sequential Givens rotations as a method of estimation, with the aim of improving the performance of the orbit estimation process and, at the same time, minimizing the computational procedure cost. Geopotential perturbations up to high order and direct solar radiation pressure were taken into account. It was also considered the position of the GPS antenna on the satellite body that, lately, consists of the influence of the satellite attitude motion in the orbit determination process. An application has been done, using real data from the Topex/Poseidon satellite, whose ephemeris is available at Internet. The best accuracy obtained in position was smaller than 5 meters for short period (2 hours) and smaller than 28 meters for long period (24 hours) orbit determination. In both cases, the perturbations mentioned before were taken into consideration and the analysis occurred without selective availability on the signals measurements.

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Apiomithrax violaceus (A. Milne Edwards, 1868 ) is a pisid majoid crab occurring in tropical and subtropical coastal waters of the eastern and western South Atlantic. Larval development consists of two zoeal stages and a megalopa. Beginning with the first zoea, the duration of each larval stage at 24degreesC was 3-8 (5+/-1), 3-5 (4+/-0.5) and 9-15 (11+/-2) days, the megalopa and first crab instar appearing 9-11 (10+/-1) and 20-27 (23+/-2) days after hatching, respectively. Larval characters agree with those proposed for the Majoidea, in having nine or more setae on the scaphognathite in the first zoea and well-developed pleopods in the second zoea. However, larvae of A . violaceus do not fit larval pisid features. Zoeal stages differ from most other Pisidae in having lateral spines, a long rostral spine extending beyond the antenna, two spines per telson fork and a dorsolateral process on the third abdominal somite. The megalopa differs in having a spine dorsally on the carapace and on the basial segment of the second pereiopod. Two characters that are potentially unique to Apiomithrax include a zoeal antenna with an exopod that is much longer than the protopod, and a rostral spine that is longer than the dorsal spine. These characters should facilitate the identification of this taxon and could also be useful for phylogenetic studies. A review of larvae of 28 species among 14 genera indicated that there is no apparent single larval character that differentiates the Pisidae, with more limited phylogenetic analyses suggesting that this is a paraphyletic group. Apiomithrax , Eurynolambrus , Pisoides , Rochinia and Scyra have the most divergent morphological characters within the family. The analysis and inclusion of additional taxa is likely to shed more light on the sister-group relationships of the Pisidae. However, based on the extent of morphological interspecific variability of known larvae it is likely that the group, as presently defined by adult morphology, is not monophyletic.

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The juvenile development of Callinectes ornatus was studied from megalopae collected in the neuston off Ubatuba, São Paulo State, Brazil. The animals were raised in the laboratory under constant temperature (25 +/- 1 degrees C), filtered sea water (35 parts per thousand) from the sampling location, and the natural photoperiod. Eleven stages of the juvenile phase were obtained. The main features of the first juvenile stage diagnostic of the species are: the number of segments in the antenna; number of setae on the exopod, endopod, basal endite and coxal endite of the maxilla, on the exopod, endopod, basal endite, coxal endite and epipod of the 1(st) maxilliped, and on the exopod, endopod and epipod of the 2(nd) maxilliped. Sexual dimorphism becomes apparent from the fourth juvenile stage onwards.

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We argue that the hypothesis of magnetic monopoles as being the highest energy cosmic ray events is unlikely. For reasonable values of the monopole mass both the observed spectrum and the arrival direction disagree with observation. Our conclusions could be evaded if (i) monopoles are accelerated in the extragalactic magnetic fields to energies much above the observed energies and (ii) the amount of energy that the monopole yields to the shower is small. (C) 1999 Elsevier B.V. B.V.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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We analyse the properties of the Sp(1, R) model states using a basis obtained from the deformed harmonic oscillator wavefunctions. We make an Sp(1, R) calculation for C-12 and consider bases obtained from oblate, triaxial and prolate intrinsic states. The model states are given by angular momentum projection of vibrational phonons, which are associated with giant monopole and quadrupole resonances.

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In insects the antennal lobes (AL) constitute the brain deutocerebrum. In bees they consist of two neuropil regions, each associated with one antenna, delimited by a layer of glial cells and somata of neurons. The neuropil is organized in distinct globular structures of dense synaptic axons coming from the olfactory organs of the antennae, known as glomeruli. In Apis mellifera, as in other eusocial species of bees, queens, workers, and drones perform different functions in the colony and consequently the organs associated with these functions undergo a differential development. In this paper we analyzed the structure and size of the differentiating AL of queens, workers, and drones during metamorphosis using light microscopy. During metamorphosis the neuropil enlarge and differentiates into concentric structures known as glomeruli. The results showed size, structural and temporal differences in the glomeruli development among the classes of individuals of the colony. The neuropil differentiation starts early and is faster in drones and newly emerged worker is the colony individual class with greater neuropil area in AL. These results are discussed taking in account the functions of the individuals in the colony. (C) Koninklijke Brill NV, Leiden, 2011.

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The numbers of sensilla coeloconica and sensilla ampullacea of segment 10 of the antennae of Caucasian and Africanized worker bees and of their hybrids were counted with the aid of a scanning electron microscope. Africanized bees have fewer sensilla than Caucasian bees and the continuous distribution obtained from the F1 values suggests polygenic inheritance for the control of this trait. There are also indications that the hybrid Brazilian Apis mellifera studied here are close to typical African bees (Apis mellifera scutellata) in terms of number of sensilla.