oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 829 )

2018 ( 1243 )

2017 ( 1193 )

2016 ( 1644 )

Custom range...

Search Results: 1 - 10 of 688196 matches for " Geber B. de A. Moura "
All listed articles are free for downloading (OA Articles)
Page 1 /688196
Display every page Item
Simula o do saldo de radia o na Serra da Mantiqueira Simulation of net radiation in the Mantiqueira mountain
Pabricio M. O. Lopes,Dalton M. Valeriano,Bernardo B. da Silva,Geber B. de A. Moura
Revista Brasileira de Engenharia Agrícola e Ambiental , 2013,
Abstract: A influência do desmatamento da Mata Atlantica sobre o microclima da Serra da Mantiqueira ainda n o é totalmente compreendida. Para conhecer as consequências do desmatamento sobre o clima serrano é necessário realizar estudos sobre o balan o de radia o na superfície. A falta de dados possibilita conjugar imagens de satélite com dados meteorológicos em um Sistema de Informa o Geográfica na determina o do balan o de radia o. O presente estudo teve por objetivo avaliar o modelo MTCLIM em dias de céu claro ou nublado para simular o balan o de radia o na Serra da Mantiqueira, divisa entre os estados de S o Paulo, Minas Gerais e Rio de Janeiro, Brasil. Imagens diárias, semanais e dezesseis dias do sensor MODIS disponíveis em 2003 foram utilizadas em rotinas específicas do MTCLIM. Alvos específicos foram selecionados para avaliar o comportamento do balan o de radia o. Observou-se que o balan o de radia o acompanhou a topografia local e é influenciado pelo tipo de uso da terra. Conclui-se que a temperatura da superfície contribui para aumentar a temperatura do ar implicando em diminui o do balan o de radia o sobre pastagem. O modelo MTCLIM demonstrou boa correla o para a temperatura do ar (R2 = 0,82) e para a radia o solar global (R2 = 0,71). The influence of deforestation of the Atlantic Forest on the microclimate of the mountain Mantiqueira is not yet fully understood. To understand the consequences of deforestation on the highland climate research is needed about the surface radiation balance. The lack of data allows combining satellite images with meteorological data in a Geographic Information System in determining the radiation balance. The study aimed to evaluate the MTCLIM model in cloudless days or cloudy sky and simulate the radiation balance in the Mantiqueira mountain, between S o Paulo, Minas Gerais and Rio de Janeiro, Brazil. Daily images, weekly and sixteen days MODIS available in 2003 were used in specific routines from MTCLIM. Specific targets were selected to evaluate the behavior of the radiation balance. It was observed that the radiation balance followed the local topography and is influenced by the type of land use. It follows that the surface temperature contributes to elevate the air temperature, resulting in lesser radiation balance on pasture. The MTCLIM model showed good correlation for air temperature (R2 = 0.82) and solar radiation (R2 = 0.71).
Zoneamento agroclimático para a cultura do pinh o-manso no estado de Pernambuco Agroclimatic zoning for physic mut crop in the state of Pernambuco
José M. C. Possas,Marcus M. Correa,Geber B. de A. Moura,Pabrício M. O. Lopes
Revista Brasileira de Engenharia Agrícola e Ambiental , 2012, DOI: 10.1590/s1415-43662012000900010
Abstract: Prop e-se, com o presente trabalho, realizar o zoneamento agroclimático da cultura do pinh o-manso (Jathopra curcas L.) no estado de Pernambuco, motivo pelo qual foram utilizados dados climáticos de temperatura do ar média e precipita o pluviométrica de 146 postos meteorológicos, dos quais 73 com série histórica de dados acima de 30 anos e outros 73 com série abaixo de 30 anos porém maior que 20 anos de observa es. A escolha do pinh o-manso foi motivada pelo potencial desta cultura como fonte de energia renovável em substitui o aos combustíveis fósseis, tanto quanto pela sua rusticidade, tornando-se uma nova op o para regi es de clima semiárido, como ocorre em grande parte da regi o Nordeste. A sele o da regi o de estudo está relacionada à variabilidade climática apresentada por esse estado e ao potencial que a referida cultura tem em se desenvolver em regi es nas quais a chuva é escassa. De acordo com o estudo, o Estado de Pernambuco apresenta 14,92% de áreas aptas ao cultivo do pinh o-manso, 44,26% de áreas restritas por deficiência hídrica e 40,82% de áreas inaptas. This study aimed to realize the agroclimatic zoning of Jathopra curcas L. crop in the State of Pernambuco. For this, climatic data of air temperature and mean rainfall of 146 meteorological stations and 73 series with historical data over 30 years and another 73 with less than 30 years but more than 20 years of observations were used. The choice of Jatropha has been motivated by the potential of this crop as a source of renewable energy to replace fossil fuels as well as for its rusticity and a new option for regions of semi-arid climate, as it occurs in the Northeast region. The selection of the study area is related to climate variability in the State and the potential that this crop has in regions where there is low precipitation. According to the study, the State of Pernambuco has 14.92% of areas suitable for production of Jatropha, 44.26% of the restricted areas by water deficit, and 40.82% of unsuitable areas.
Albedo à superfície a partir de imagens Landsat 5 em áreas de cana-de-a?úcar e cerrado
Giongo, Pedro R.;Moura, Geber B. de A.;Silva, Bernardo B.;Rocha, Humberto R. da;Medeiros, Sérgio R. R. de;Nazareno, Aérica C.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2010, DOI: 10.1590/S1415-43662010000300007
Abstract: this study aimed to estimate albedo data from the land surface sensor using the images of thematic mapper (tm) satellite landsat 5 and to compare it with data from two agrometeorological stations located in the region of cerrado, and another in sugar cane cultivation. the study area is located in the municipality of santa rita do passa quatro - sp, brazil. to carry out the study six orbital images were obtained from the satellite landsat 5 tm sensors in the orbit 220 and in the section 75, for the dates of 22/02, 11/04, 29/05, 01/08, 17/08 and 21/11 (all in the year of 2005) which correspond to the days 53, 101, 149, 213, 229 and 325, respectively. the geometric correction for images was performed and the letters of albedo were generated. the algorithm sebal estimated, satisfactorily, the values of albedo on the surface areas of cerrado and sugar cane in the region of santa rita do passa quatro - sp, consistent with observations made of the surface albedo.
Rela??o entre a precipita??o do leste do Nordeste do Brasil e a temperatura dos oceanos
Moura, Geber B. de A.;Arag?o, José O. R. de;Melo, José S. P. de;Silva, Ana P. N. da;Giongo, Pedro R.;Lacerda, Francinete F.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2009, DOI: 10.1590/S1415-43662009000400014
Abstract: the objective of this work was to correlate the northeast of brazil (neb) rainfall grouped in one homogeneous cluster with the global sea surface temperature (sst) anomalies. the data covered the period from 1945 to 1985 and the analyses shows that there are influences from the atlantic and pacific ocean over the eastern neb's rainfall, with a higher correlation for the atlantic, especially in the dipole area (correlation values greater than 0.6, and p < 0.05). the 1995 servain and arnault meridional (atlantic dipole) and equatorial modes were detected during several lag analyses. in the eastern tropical pacific ocean in the region of el ni?o-3 negative correlations were found, indicating the presence of the descendant branches of the walker cell in the sector east of the neb.
Potencial agroclimático para a Alpinia purpurata, no Estado de Pernambuco
Medeiros, Sérgio R. R.;Moura, Geber B. A.;Giongo, Pedro R.;Silva, Ana P. N.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2009, DOI: 10.1590/S1415-43662009000200009
Abstract: this study aimed at accomplishing the agroclimatic zoning of pernambuco state, in order to provide subsidies for the selection of areas for implantation of alpinia purpurata tropical flower. the climatic data of 123 localities (69 with a period above 30 years and 54 below 30 years) were used, thus getting a better representation of the data in the state. from climatic data of the average temperatures of air and rainfall, the climatologic water balance has been calculated. the cities of igarassú, primavera, goiana and s?o louren?o da mata were chosen to be climatic representatives as they are the producers of the species in pernambuco. by having the data of the water balance and the minimum and maximum air temperatures, the indexes of thermal and water limit in relation to the requirements of the species in the representative cities has been estimated, and only after this the indexes were extrapolated for the whole state. in accordance with this study, pernambuco presented 6 localities with full suitability, 16 with regular suitability and 101 unsuitable for the cultivation of species.
Rela??o entre a precipita??o no setor leste do nordeste do Brasil e a temperatura da superfície nos oceanos Atlantico e Pacífico
Moura, Geber Barbosa de A.;Arag?o, José Oribe Rocha de;Lacerda, Francinete Francis;Passavante, José Zanon de O.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2000, DOI: 10.1590/S1415-43662000000200019
Abstract: the main purpose of this study was to relate the rainfall in eastern northeast brazil (neb) with the sea surface temperature (sst) in the atlantic (dipole area) and pacific oceans during the 1945-1985 period. this analysis shows how anomalous sst events influence precipitation in the eastern part of neb, from the states of rio grande do norte through to bahia. the main significant results were: in years with a negative temperature gradient in the atlantic, the rainfall was below the long term mean in rio grande do norte (84%) and paraíba (74%); in years with neutral gradient, the rainfall was normal or above normal in paraíba (73%); in years with positive temperature gradient (south minus north), hereby called favorable gradient, the rainfall was above the long term mean, in alagoas (73%), sergipe (73%) and bahia (73%).
Coherent electron dynamics in a two-dimensional random system with mobility edges
F. A. B. F. de Moura,M. L. Lyra,F. Dominguez-Adame,V. A. Malyshev
Physics , 2007, DOI: 10.1088/0953-8984/19/5/056204
Abstract: We study numerically the dynamics of a one-electron wave packet in a two-dimensional random lattice with long-range correlated diagonal disorder in the presence of a uniform electric field. The time-dependent Schr\"{o}dinger equation is used for this purpose. We find that the wave packet displays Bloch-like oscillations associated with the appearance of a phase of delocalized states in the strong correlation regime. The amplitude of oscillations directly reflects the bandwidth of the phase and allows to measure it. The oscillations reveal two main frequencies whose values are determined by the structure of the underlying potential in the vicinity of the wave packet maximum.
Bloch oscillations in an aperiodic one-dimensional potential
F. A. B. F. de Moura,M. L. Lyra,F. Dominguez-Adame,V. A. Malyshev
Physics , 2004, DOI: 10.1103/PhysRevB.71.104303
Abstract: We study the dynamics of an electron subjected to a static uniform electric field within a one-dimensional tight-binding model with a slowly varying aperiodic potential. The unbiased model is known to support phases of localized and extended one-electron states separated by two mobility edges. We show that the electric field promotes sustained Bloch oscillations of an initial Gaussian wave packet whose amplitude reflects the band width of extended states. The frequency of these oscillations exhibit unique features, such as a sensitivity to the initial wave packet position and a multimode structure for weak fields, originating from the characteristics of the underlying aperiodic potential.
Critical wave-packet dynamics in the power-law bond disordered Anderson Model
R. P. A. Lima,F. A. B. F. de Moura,M. L. Lyra,H. N. Nazareno
Physics , 2005, DOI: 10.1103/PhysRevB.71.235112
Abstract: We investigate the wave-packet dynamics of the power-law bond disordered one-dimensional Anderson model with hopping amplitudes decreasing as $H_{nm}\propto |n-m|^{-\alpha}$. We consider the critical case ($\alpha=1$). Using an exact diagonalization scheme on finite chains, we compute the participation moments of all stationary energy eigenstates as well as the spreading of an initially localized wave-packet. The eigenstates multifractality is characterized by the set of fractal dimensions of the participation moments. The wave-packet shows a diffusive-like spread developing a power-law tail and achieves a stationary non-uniform profile after reflecting at the chain boundaries. As a consequence, the time-dependent participation moments exhibit two distinct scaling regimes. We formulate a finite-size scaling hypothesis for the participation moments relating their scaling exponents to the ones governing the return probability and wave-function power-law decays.
Estrutura de comunidades necrófagas: efeito da partilha de recursos na diversidade
Moura, Mauricio O.;Carvalho, Claudio J. B. de;Monteiro-Filho, Emygdio L. A.;
Revista Brasileira de Zoologia , 2005, DOI: 10.1590/S0101-81752005000400046
Abstract: even though an extensive framework has been develop on community structuring process, there have been few tests of mechanisms promoting coexistence in local communities.we report field experiments designed to assess the role of resource partitioning as a mechanism promoting coexistence and enhancing diversity using necrophagous communities as a model system. in order to achieve this objective we let in field to be colonize, 36 carcasses with weight ranging from 17 to 440 g, performing three repetitions. the community was composed by twenty one species of necrophagous flies. initial analysis suggest some level of resource partitioning but there were more overlap than could be accounted by chance and the level of specialization on carcass size were very low. based on this findings resource partitioning could not be promoting coexistence and another mechanism should be invoked to account for such effect.
Page 1 /688196
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.