Navegando por Autor "PINTO, Gabriel Silva"

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Acesso aberto (Open Access)
Análise evolutiva da morfologia e ecologia em espécies continentais de lagartos do gênero Anolis daudin 1804 (Squamata : Polychrotidae)
(Universidade Federal do Pará, 2007-10-02) PINTO, Gabriel Silva; ÁVILA-PIRES, Teresa Cristina Sauer de; http://lattes.cnpq.br/1339618330655263
Acesso aberto (Open Access)
Análise morfométrica em cinco espécies do gênero Mabuya Fitzinger, 1826 (Squamata : Scincidae)
(Universidade Federal do Pará, 2002) PINTO, Gabriel Silva; ÁVILA-PIRES, Teresa Cristina Sauer de; http://lattes.cnpq.br/1339618330655263
The present study has as its main objective to analyse the ontogenetic variation of body shape in the South American skinks Mabuya agi/is Boulenger, 1887; M. bistriata (Spix, 1825); M. guaporicola Dunn, 1936; M. rnacrorhyncha Hoge, 1946 and M. nigropunctata (Spix, 1825). Interspecific differences of body proportions as a possible result of allometric growth in these species are also examined. PCA analysis was used for estimate the both ontogenetic trends and allometric growth. Ontogenetic trend lines were significantly different between M. guaporicola and the others species, and between M. bistriata and M. nigropunctata. Ali of the other pairs showed significantly different Y intercept between each other. Analysis of the allometric coefficients indicates that relative reduction of limbs associated with body elongation in Mabuya guaporicola are due to the reduction of its hands, feet and specially digits; M. rnacrorhyncha presents a high and stout pectoral girdle and its hands show an accentuated reduction; in M. bistriata, its arms are relatively short and its thigh and tibia elongate. M. nigropunctata is the species which the least modified body shape during ontogeny. The association of these results with data on habitats utilized by each species (obtained from the literature) indicates that some morphological specializations found in each species could be explained as functional adaptations to their habitats.
Acesso aberto (Open Access)
Controle do diagrama de radiação de dipolo de grafeno pelo potencial químico
(Universidade Federal do Pará, 2018-12-13) PINTO, Gabriel Silva; COSTA, Karlo Queiroz da; http://lattes.cnpq.br/7932708321834647
This work presents a method of controlling the radiation diagram of a graphene dipole by the chemical potential. The dipole analyzed has rectangular geometry with power supply by voltage source in the center, where each arm of the dipole is maintained to a different chemical potential. The geometry is analyzed by the two-dimensional moments method (MoM-2D) in MATLABr software, with an equivalent surface impedance. Calculations of the main radiative properties of the antenna are presented as a function of the chemical potential. The results show that the greater the difference between the chemical potentials, the greater the displacement of the main lobe of the radiation diagram.