Proposal of a hybrid rectifier structure with HPF and low THD suitable for front-end trolleybuses systems supplied by AC distribution networks

This paper presents the development and the experimental analysis of a new single-phase hybrid rectifier structure with high power factor (PF) and low harmonic distortion of current (THDI), suitable for application in traction systems of electrical vehicles pulled by electrical motors (trolleybus), which are powered by urban distribution network. This front-end rectifier structure is capable of providing significant improvements in trolleybuses systems and in the urban distribution network costs, and efficiency. The proposed structure is composed by an ordinary single-phase diode rectifier with parallel connection of a switched converter. It is outlined that the switched converter is capable of composing the input line current waveform assuring high power factor (HPF) and low THDI, as well as ordinary front-end converter. However, the power rating of the switched converter is about 34% of the total output power, assuring robustness and reliability. Therefore, the proposed structure was named single-phase HPF hybrid rectifier. A prototype rated at 15kW was developed and analyzed in laboratory. It was found that the input line current harmonic spectrum is in accordance with the harmonic limits imposed by IEC61000-3-4. The principle of operation, the mathematical analysis, the PWM control strategy, and experimental results are also presented in this paper. © 2009 IEEE.

The functional biogeography of species: Biogeographical species roles of birds in Wallacea and the West Indies

Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship between species traits and large-scale species distribution patterns in archipelagos, we use a network approach to classify birds as one of four biogeographical species roles: peripherals, connectors, module hubs, and network hubs. These roles are based upon the position of species within the modular network of islands and species in Wallacea and the West Indies. We test whether species traits - including habitat requirements, altitudinal range-span, feeding guild, trophic level, and body length - correlate with species roles. In both archipelagos, habitat requirements, altitudinal range-span and body length show strong relations to species roles. In particular, species that occupy coastal- and open habitats, as well as habitat generalists, show higher proportions of connectors and network hubs and thus tend to span several biogeographical modules (i.e. subregions). Likewise, large body size and a wide altitudinal range-span are related to a wide distribution on many islands and across several biogeographical modules. On the other hand, species restricted to interior forest are mainly characterized as peripherals and, thus, have narrow and localized distributions within biogeographical modules rather than across the archipelago-wide network. These results suggest that the ecological amplitude of a species is highly related to its geographical distribution within and across bio geographical subregions and furthermore supports the idea that large-scale species distributions relate to distributions at the local community level. We finally discuss how our biogeographical species roles may correspond to the stages of the taxon cycle and other prominent theories of species assembly. © 2013 The Authors.

Uma abordagem do funcionamento discursivo das construções adversativas sob a ótica da gramaticalização

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

Gramaticalização de juntivos adversativos na história do português

Pós-graduação em Estudos Linguísticos - IBILCE

Ação do vento em cobertura de madeira roliça para galpões de fertilizantes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo das ligações por conectores de chapas com dentes estampados em peças estruturais de madeira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do uso dos conectores discursivos nas produções escritas em Espanhol por aprendentes brasileiros

Pós-graduação em Letras - FCLAS

Influência do tipo de conector na união dente e implantes de hexágono interno e externo: estudo pelo método da fotoelasticidade

Pós-graduação em Odontologia - FOA

Resistência à fratura de próteses parciais fixas de zircônia: efeito da aplicação da cerâmica de cobertura e do jateamento na região gengival dos conectores e pônticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividade epilinguística em sala de aula: as interpretações naturais feitas pelos alunos

Pós-graduação em Linguística e Língua Portuguesa - FCLAR

Ensaio de ligações de estruturas de madeira por chapas com dentes estampados em quatro espécies da família leguminosas

In the last years, the use of industrialized systems of lattice structures of wood as an alternative in the construction processes, is becoming more popular in Brazil, mainly for their commitment to the environment.The industrialized system of wooden lattice structures consists in a production of lattice structures, composed of pieces of wood where their mechanical connections are made with the sheet multi-toothed connectors (CDE).Among the many challenges to make this system competitive, the whole system of the connections between the pieces of wood not only must show functionality, but also speed, strength, versatility and economy. Referenced at Brazilian Standard for Wood Structures (NBR 7190/1997 - Project of timber structures) the sheet multi-toothed connectors, are analyzed using three test methods: tensile strength parallel to grain, tensile strength normal to the fibers and shear strength, all of them in two positions, αCH0=0o e αCH0=90o to four types of wood: Angelim (Vatairea heteroptera Ducke); Red-Angico (Parapiptadenia rigida (Benth) Brenae); Garapa (Apuleia leiocarpa (Vog.) Macbr) and Jatoba (Hymenaea stilbocarpa Hayne), belonging to the Leguminosae family and founded in several regions of Brazil.The purpose of this manuscript consists to analyze the mechanical connections with the sheet multi-toothed connectors through tests from NBR7190/1997

Proposta de conector para ensaios de ligações CDE submetidas à tração perpendicular as fibras em madeira de pinus

The growth of urban population associated with the shortage of supply of public infrastructure such as hospitals, kindergartens, schools, among others, has reinforced the need to develop alternative methods that simplify the construction processes and allows for a reduction in these costs works. The conventional processes have increasingly been shown ineffective to solve the problem of demand for different types of urban and rural buildings. Given this fact, industrial construction processes can gain space and have proven to be highly interesting to solve the above problems, in particular, considering the cost-effective and time. Therefore, this study aimed to determine the influence of moisture on the strength of metal plate connections connectors (printed plate with teeth). For the sizing of the links between structural lumber using metal connectors with teeth prints; controlled process variables (drying of the wood and the different moisture contents), and finally found results and compare them with different literatures order to obtain a qualitative efficiency of the process. Some specimens had very low expectations, can be explained by the presence of bone marrow, and pre-existing cracks. Thus, the results were discarded for further analysis and more accurate results

Marcadores discursivos: uma proposta lexicográfica

Spanish is a language that in recent years has been growing in importance both politically and socially and economically, since some of the major international markets such as Chile, Spain, Mexico and Argentina, among many, have this language as the official language. This fact motivated us to conduct research that could, in some way, contribute to the teaching of this language in Brazil. Thus under the aegis of the theories and practices of bilingual lexicography, we seek to describe and analyze the treatment that some Spanish - Portuguese bilingual dictionaries present in our market give to the sentence connectors. From a textual corpus selected the markers and observe how the dictionaries analyzed work with this type of unit. We found that the information contained in these lexicographical works is not sufficient to meet the needs of Brazilian learners. Then, we proposed a macrostructure of a passive bilingual dictionary of sentence connectors in the language pair Spanish - Portuguese. Our research aims to contribute to bilingual lexicography both in regard to theoretical and methodological reflections on the application of these theories. Our contribution aims to fabricate materials for the teaching of Spanish in Brazil

Língua wauja (arawak): uma descrição fonológica e morfossintática

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

Verificação da eficiência do modelo de Mohler na resposta do comportamento de vigas mistas de madeira e concreto

The aim of this research study was to evaluate the structural behaviour of the wood and concrete composite system for bridge decks with emphasis on the metal shear connectors. Experimental tests were performed on composite specimens and wood and concrete beams with a metallic connector system in an X position, using CS100900-type screws. All specimens and beams were submitted to static loads until failure in order to obtain the strength and stiffness of the connection system. The experimental results for the stiffness of the beams were compared with the analytical results obtained through the Mohler model, presenting good equivalence for service loads. The experimental results obtained demonstrate that the most significant damage in composite systems occurred in the connectors' areas.