971 resultados para Arc adjacency operator
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Using the pure spinor formalism for the superstring, the vertex operator for the first massive states of the open superstring is constructed in a manifestly super-Poincaré covariant manner. This vertex operator describes a massive spin-two multiplet in terms of ten-dimensional superfields. © SISSA/ISAS 2002.
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Recent field investigations and geochronological studies of Neoproterozoic rocks in the northwestern part of the Borborema Province, Ceará State, NE Brazil provide important clues pertaining to the nature of convergence between the Borborema Province and the West African-São Luis craton during the assembly of West Gondwana. U-Pb zircon data indicate that the earliest evidence of convergent magmatism along the northwest margin of the Borborema Province occurred around 777 Ma, and was followed by the development of a large continental arc batholith (Santa Quitéria batholith) between ca. 665 and 591 Ma within the central part of Ceará State. These findings, along with supporting geophysical data, suggest that convergence between the Borborema Province and the West African-São Luis craton involved closure of an oceanic realm with subduction polarity to the southeast beneath the northwestern part of the province. Consequently, it seems likely that the Pharusian Ocean was continuous from the Hoggar Province in West Africa into South America during the late Neoproterozoic and additional data suggests that it may have even been connected with the Goianides Ocean of the Brasília Belt farther to the southwest.
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Authors - Magno AFF, Martins RP, Vaz LG, Martins LP Objectives - Evaluate the shear bond strength (SBS) and the adhesive remnant index (ARI) of indirect bonded lingual brackets using xenon plasma arc light, light-emitting diode (LED) and conventional quartz-tungsten-halogen light. Material and Methods - Lingual brackets were bonded indirectly to 60 premolars divided to three groups according to the curing light used: Group 1, plasma arc for 6 s; Group 2, LED for 10 s; and Group 3, halogen light for 40 s. After bonding, the specimens were subjected to a shear force until debonding. The debonding pattern was assessed and classified according to the ARI scores. The mean shear bond strengths were accessed by anova followed by the Student-Newman-Keuls test for multiple comparisons. ARI scores were assessed using the chi-square test. Results - The three groups showed significant differences (p < 0.001), with the averages of group 1 < group 2 < group 3. Groups showed no differences regarding ARI scores. Conclusion - Bonding lingual brackets indirectly with plasma arc, during 60% of the time used for the LED, produced lower SBS than obtained with the latter. Using LED during 25% of the time of the halogen light produced lower SBS than obtained with the latter. These differences did not influence the debonding pattern and are clinically acceptable according to the literature. © 2010 John Wiley & Sons A/S.
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The Capacitated Arc Routing Problem (CARP) is a well-known NP-hard combinatorial optimization problem where, given an undirected graph, the objective is to find a minimum cost set of tours servicing a subset of required edges under vehicle capacity constraints. There are numerous applications for the CARP, such as street sweeping, garbage collection, mail delivery, school bus routing, and meter reading. A Greedy Randomized Adaptive Search Procedure (GRASP) with Path-Relinking (PR) is proposed and compared with other successful CARP metaheuristics. Some features of this GRASP with PR are (i) reactive parameter tuning, where the parameter value is stochastically selected biased in favor of those values which historically produced the best solutions in average; (ii) a statistical filter, which discard initial solutions if they are unlikely to improve the incumbent best solution; (iii) infeasible local search, where high-quality solutions, though infeasible, are used to explore the feasible/infeasible boundaries of the solution space; (iv) evolutionary PR, a recent trend where the pool of elite solutions is progressively improved by successive relinking of pairs of elite solutions. Computational tests were conducted using a set of 81 instances, and results reveal that the GRASP is very competitive, achieving the best overall deviation from lower bounds and the highest number of best solutions found. © 2011 Elsevier Ltd. All rights reserved.
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The traditional operational and hazard control paradigm of an electrical installation has several issues pertaining to the diversity of equipment. A large maintenance inventory is a reason for concern for any manager, but the arc flash hazard is a particularly new phenomenon and the effects of equipment diversity on this phenomenon are even newer. The class of arc hazard can be increased, simply by changing the fuse link or circuit breaker manufacturer. Management pressure to operate as well as non-standard practices and installations are also partly responsible. The aim of this study is to take a typical situation in an industrial plant and to statistically simulate, by means of a dedicated software program, the fuse arc flash interruption performance of various manufacturers. The purpose of this study is to obtain a more objective indication of the influence of different fuse link manufacturers on arc flash incident energy. © 2011 IEEE.
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The traditional operational and hazard control paradigm of an electrical installation has several issues pertaining to the diversity of equipment. A large maintenance inventory is a reason for concern for any manager, but the arc-flash hazard is a particularly new phenomenon, and the effects of equipment diversity on this phenomenon are even newer. The class of arc hazard can be simply increased by changing the fuse link or circuit breaker manufacturer. Management pressure to operate as well as nonstandard practices and installations are also partly responsible. The aim of this article is to take a typical situation in an industrial plant and to statistically simulate, by means of a dedicated software program, the fuse arc-flash interruption performance of various manufacturers. The purpose of this article is to obtain a more objective indication of the influence of different fuse link manufacturers on arc-flash incident energy. © 1975-2012 IEEE.
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In the study of the Type II superstring, it is useful to consider the BRST complex associated to the sum of two pure spinors. The cohomology of this complex is an infinite-dimensional vector space. It is also a finite-dimensional algebra over the algebra of functions of a single pure spinor. In this paper we study the multiplicative structure. © 2013 World Scientific Publishing Company.
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Includes bibliography
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O Batólito Cerro Porã é um corpo de aproximadamente 30 por 4 km de extensão, localizado na região de Porto Murtinho, Mato Grosso do Sul. Situa-se nos domínios do Terreno Rio Apa, porção sul do Cráton Amazônico. Constitui-se pela Fácies sienogranítica rosa e Fácies monzogranítica cinza. A primeira é caracterizada por textura equi a, essencialmente, inequigranular xenomórfica e pela presença constante de intercrescimentos gráfico e granofíric; constitui-se por feldspatos alcalinos, quartzo e plagioclásio, tendo biotita como único máfico primário. A Fácies monzogranítica cinza apresenta textura porfirítica, com uma matriz de granulação fina gráfica a granofírica e consiste de quartzo, plagioclásio, feldspatos alcalinos e agregados máficos (biotita e anfibólio). Ambas foram metamorfizadas na fácies xisto verde e a Fácies sienogranítica rosa mostra-se milonitizada quando em zonas de cisalhamento. Foi identificado um evento deformacional dúctil-rúptil originado em regime compressivo, responsável pela geração de xistosidade e lineação de estiramento mineral. A Zona de Cisalhamento Esperança relaciona-se a esta fase e reflete a história cinemática convergente, reversa a de cavalgamento, com transporte de topo para NWW. Quimicamente, esses litotipos classificam-se como granitoides do tipo A2 da série alcalina potássica saturada em sílica. Determinação geocronológica obtida pelo método U-Pb (SHRIMP) em zircão, forneceu idade de 1749 ±45 Ma para sua cristalização. Do ponto vista geotectônico, admite-se que o Granito Cerro Porã corresponda a um magmatismo associado a um arco vulcânico desenvolvido no Estateriano e que sua colocação se deu no estágio tardi a pós-orogênico.
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Neste trabalho apresentam-se os resultados do mapeamento geológico e caracterização petrológica da Formação Serra da Bocaina, pertencente ao Arco Magmático Amoguijá do Terreno Rio Apa, sul do Cráton Amazônico. A Formação Serra da Bocaina, na serra da homônima, consiste de rochas vulcânicas paleoproterozoicas de composição intermediária a predominantemente ácida, classificadas como andesito e riolitos, subdivididas em cinco fácies petrográficas sendo quatro piroclásticas e uma efusiva, que mantêm contato tectônico, a leste, com o Granito Carandá. Nas rochas estudadas estruturas tectônicas são formadas em duas fases deformacionais compressivas de natureza dúctil e dúctil-rúptil, respectivamente. A primeira fase, mais intensa, é observada ao longo de toda a área estudada e é responsável pela Zona de Cisalhamento Santa Rosa enquanto a segunda fase é mais discreta e localizada. O tratamento geoquímico indica que essas rochas foram geradas num ambiente de arco-vulcânico a partir de um magmatismo calcioalcalino de médio a alto-K, peraluminoso. Estas rochas retratam um evento magmático extrusivo, de natureza explosiva, relacionado à evolução do Arco Magmático Amoguijá, conforme resultado Pb-Pb em zircão de 1877,3 ± 3,9 Ma., interpretada como idade de cristalização destas rochas.
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Vertex operators in string theory me in two varieties: integrated and unintegrated. Understanding both types is important for the calculation of the string theory amplitudes. The relation between them is a descent procedure typically involving the b-ghost. In the pure spinor formalism vertex operators can be identified as cohomology classes of an infinite-dimensional Lie superalgebra formed by covariant derivatives. We show that in this language the construction of the integrated vertex from an unintegrated vertex is very straightforward, and amounts to the evaluation of the cocycle on the generalized Lax currents.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)