Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 678 )

2018 ( 922 )

2017 ( 877 )

2016 ( 1221 )

Custom range...

Search Results: 1 - 10 of 489608 matches for " Pabricio M. O. Lopes "
All listed articles are free for downloading (OA Articles)
Page 1 /489608
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).
Generic properties for random repeated quantum iterations
Artur O. Lopes,M. Sebastiani
Physics , 2015,
Abstract: We denote by $M^n$ the set of $n$ by $n$ complex matrices. Given a fixed density matrix $\beta:\mathbb{C}^n \to \mathbb{C}^n$ and a fixed unitary operator $U : \mathbb{C}^n \otimes \mathbb{C}^n \to \mathbb{C}^n \otimes \mathbb{C}^n$, the transformation $\Phi: M^n \to M^n$ $$ Q \to \Phi (Q) =\, \text{Tr}_2 (\,U \, ( Q \otimes \beta )\, U^*\,)$$ describes the interaction of $Q$ with the external source $\beta$. The result of this is $\Phi(Q)$. If $Q$ is a density operator then $\Phi(Q)$ is also a density operator. The main interest is to know what happen when we repeat several times the action of $\Phi$ in an initial fixed density operator $Q_0$. This procedure is known as random repeated quantum iterations and is of course related to the existence of one or more fixed points for $\Phi$. In \cite{NP}, among other things, the authors show that for a fixed $\beta$ there exists a set of full probability for the Haar measure such that the unitary operator $U$ satisfies the property that for the associated $\Phi$ there is a unique fixed point $ Q_\Phi$. Moreover, there exists convergence of the iterates $\Phi^n (Q_0) \to Q_\Phi$, when $n \to \infty$, for any given $Q_0$ We show here that there is an open and dense set of unitary operators $U: \mathbb{C}^n \otimes \mathbb{C}^n \to \mathbb{C}^n \otimes \mathbb{C}^n $ such that the associated $\Phi$ has a unique fixed point. We will also consider a detailed analysis of the case when $n=2$. We will be able to show explicit results. We consider the $C^0$ topology on the coefficients of $U$. In this case we will exhibit the explicit expression on the coefficients of $U$ which assures the existence of a unique fixed point for $\Phi$. Moreover, we present the explicit expression of the fixed point $Q_\Phi$
Poncelet pairs and the Twist Map associated to the Poncelet Billiard
Artur O. Lopes,M. Sebastiani
Mathematics , 2007,
Abstract: We show that for a fixed curve $K$ and for a family of variables curves $L$, the number of $n$-Poncelet pairs is $\frac{e (n)}{2}$, where $e(n)$ is the number of natural numbers $m$ smaller than $n$ and which satisfies mcd $ (m,n)=1$. The curvee $K$ do not have to be part of the family. In order to show this result we consider an associated billiard transformation and a twist map which preserves area. We use Aubry-Mather theory and the rotation number of invariant curves to obtain our main result. In the last section we estimate the derivative of the rotation number of a general twist map using some properties of the continued fraction expansion .
LOPES Jorge O .,JOBIM Neicy M.
Revista do Instituto de Medicina Tropical de S?o Paulo , 1998,
Creation of Homoclinic Tangencies in Hamiltonians by the Suspension of Poincaré Sections
Mário Bessa,Jo?o Lopes Dias
Mathematics , 2011,
Abstract: In this note we show that for any Hamiltonian defined on a symplectic 4-manifold M and any point p in M, there exists a C2-close Hamiltonian whose regular energy surface through p is either Anosov or it contains a homoclinic tangency. Our result is based on a general construction of Hamiltonian suspensions for given symplectomorphisms on Poincar\'e sections already known to yield similar properties.
Phase Transitions in One-dimensional Translation Invariant Systems: a Ruelle Operator Approach
Leandro M. Cioletti,Artur O. Lopes
Statistics , 2014, DOI: 10.1007/s10955-015-1202-4
Abstract: We consider a family of potentials f, derived from the Hofbauer potentials, on the symbolic space Omega=\{0,1\}^\mathbb{N} and the shift mapping $\sigma$ acting on it. A Ruelle operator framework is employed to show there is a phase transition when the temperature varies in the following senses: the pressure is not analytic, there are multiple eigenprobabilities for the dual of the Ruelle operator, the DLR-Gibbs measure is not unique and finally the Thermodynamic Limit is not unique. Additionally, we explicitly calculate the critical points for these phase transitions. Some examples which are not of Hofbauer type are also considered. The non-uniqueness of the Thermodynamic Limit is proved by considering a version of a Renewal Equation. We also show that the correlations decay polynomially and that each one of these Hofbauer potentials is a fixed point for a certain renormalization transformation.
Eretmochelys imbricata: Lessons to Learn from a Monitoring Program in the North of Mozambique  [PDF]
Rita Anastácio, Cardoso Lopes, Jorge Ferr?o, Mário Jorge Pereira
Natural Resources (NR) , 2017, DOI: 10.4236/nr.2017.85024
Abstract: Monitoring programs for nesting turtles around the world have been important to build up a matrix of information for better comprehension of their behaviour and dispersion. The Western Indian Ocean has several monitoring programs that are being used to reveal migration routes, phylogenetic interconnections and nesting behaviour patterns. We determined the nesting parameters for 69 records of hawksbill turtles collected during the Vamizi Island monitoring program. We also determined carapace measurements parameters of the turtles caught by fishermen in the area and give some considerations to improve the conservation of this species. Results show that the island receives hawksbill females all year long. Vamizi is a small nesting ground for this species, with an incubation period of 60.9 ± 10.6 days and a high reproductive rate. The turtles’ carapace measurements (SCL 42.0 ± SD 9.0 cm) revealed the existence of young individuals, foraging near the island, and their vulnerability to the fishing practices. This study strongly defends the need to identify more developmental and nesting spots, to be protected near Vamizi, to establish a solid network of marine reserves and corridors in the north of the Mozambique Channel.
Sporothrix schenckii and sporotrichosis
Lopes-Bezerra, Leila M.;Schubach, Armando;Costa, Rosane O.;
Anais da Academia Brasileira de Ciências , 2006, DOI: 10.1590/S0001-37652006000200009
Abstract: for a long time sporotrichosis has been regarded to have a low incidence in brazil; however, recent studies demonstrate that not only the number of reported cases but also the incidence of more severe or atypical clinical forms of the disease are increasing. recent data indicate that these more severe forms occur in about 10% of patients with confirmed diagnosis. the less frequent forms, mainly osteoarticular sporotrichosis, might be associated both with patient immunodepression and zoonotic transmission of the disease. the extracutaneous form and the atypical forms are a challenge to a newly developed serological test, introduced as an auxiliary tool for the diagnosis of unusual clinical forms of sporotrichosis.
A practical method for screening for beta-galactosidase secreting microbial colonies
Barreto, Eriana S.;Silva, Daison O.;Passos, Flavia M. Lopes;
Brazilian Journal of Microbiology , 2000, DOI: 10.1590/S1517-83822000000100009
Abstract: microbial colonies were replicated on ynb? agar plates overlaid with soft agar containing the glucose-oxidase/peroxidase (biotrola) system. the pink color developed around the colonies was the result of the reaction of the glucose generated by the extracellular hydrolysis of lactose by b-galactosidase, indicating secretion of this enzyme. this method proved to be very convenient for testing hundreds of colonies grown on agar plates for b-galactosidase secretion by microbial cells.
Imaturos de Culicidae (Diptera) encontrados em recipientes instalados em mata residual no munícipio de Londrina, Paraná, Brasil
Zequi, Jo?o A. C.;Lopes, José;Medri, ísis M.;
Revista Brasileira de Zoologia , 2005, DOI: 10.1590/S0101-81752005000300021
Abstract: forest fragments in an urban area were found to be a situable site for culicidae breeding. this research aims to inventory the culicidae species that use artificial breeding sites, their coexistence, and the population variation in a fragment forest in the londrina city, paraná state. biweekly collecting efforts were performed from october 1995 to september 1996 using tires and bamboo internodes traps installed at a ground level and bamboo internodes traps at two 2 m height. a total of 12,656 culicid specimens belonging to five genus and 11 species were collected. the most abundant species in those artificial breeding sites were limatus durhami theobald, 1901, culex eduardoi couple & garcia, 1968, aedes terrens (walker, 1856), culex quinquefasciatus say, 1823 and aedes albopictus. (skuse, 1894). the greatest number of individuals was collect in tires and limatus durhami and aedes terrens, showed a preference to the breeding sites. the capture of aedes aegypti (linnaeus, 1762), aedes albopictus and haemagogus leucocelaenus (dyar & shannon, 1924) in different collections efforts indicates that this kind of environment must be taken in account in the vector control actions and constantly monitored.
Page 1 /489608
Display every page Item

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