Power flow optimization for grid connected inverter using evolutionary algorithm and additional control loop

In this work it is proposed to validate an evolutionary tuning algorithm in plants composed by a grid connected inverter. The optimization aims the tuning of the slopes of P-Ω and Q-V curves so that the system is stable, damped and minimum settling time. Simulation and experimental results are presented to prove the feasibility of the proposed approach. However, experimental results demonstrate a compromising effect of grid frequency oscillations in the active power transferring. In addition, it was proposed an additional loop to compensate this effect ensuring a constant active power flow. © 2011 IEEE.

A new design methodology for multipulse rectifiers with Delta auto-connected transformers and a retrofit application in Adjustable Speed Drives (ASDs)

Multipulse rectifiers can replace a conventional six pulse three-phase rectifier (diode bridge) providing a DC voltage with low ripple, low Total Harmonic Distortion of current (THDi) and a high Power Factor (PF). In this context is presented a multipulse rectifier with generalized Delta-differential autotransformer topology, which can provide any level of DC output voltage for any level of three-phase AC input voltage. This paper presents all the possible configurations for Delta topology in order to choose, through graphics, one configuration that presents reduced weight and volume. The average voltage on the DC bus must be compatible with the DC voltage in the six pulse rectifier used in commercial ASDs. Therefore, it is possible to apply the retrofit technique to replace the conventional bridge rectifier by the proposed multipulse rectifier. Based on mathematic models and simulation results, an 18-pulse rectifier with Delta topology, 220 V of line voltage, 315 V of DC output, and rating 2.5 kW of power was designed, implemented and applied for three different commercial ASDs. Experimental results as voltage and current waveforms and results about PF and THDi will be presented. © 2012 IEEE.

Structure, characterization and near-infrared emission of a novel 6-connected uninodal 3D network of Nd(III) containing 2,5-thiophenedicarboxylate anion

The novel coordination polymer with the formula {[Nd2(2,5-tdc)3(dmf)2(H2O)2].dmf.H2O}n (2,5-tdc2-=2,5-thiophedicarboxylate anion and dmf=dimethylformamide) has been synthesized and characterized by thermal analysis (TG/DTA), vibrational spectroscopy (FTIR) and single crystal X-ray diffraction analysis (XRD). Structure analysis reveals that Nd(III) ions show dicapped trigonal prism coordination geometry. The 2,5-tdc2- ligands connect four Nd(III) centers, adopting (κ1 - κ1) - (κ1 - κ1) - μ4 coordination mode, generating an interesting 6-connected uninodal 3D network. Photophysical properties were studied using diffuse reflectance spectroscopy (DR) and excitation/emission spectra. The photoluminescence data show the near infrared emission (NIR) with the characteristic 4F3/2→4IJ (J=9/2, 11/2 and 13/2) transitions of Nd(III) ion, indicating that 2,5-tdc2- is able to act as a sensitizer for emission in NIR region. © 2013 Elsevier B.V.

A investigação sobre a própria prática de um professor iniciante sob o olhar da teoria da recontextualização

Pós-graduação em Educação para a Ciência - FC

A nação é católica: educação e cidadania nas primeiras décadas republicanas (1890 a 1930)

Pós-graduação em História - FCHS

A censura no Pasquim (1969-1975): as vozes não-silenciadas de uma geração

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Em busca do discurso poético de Aristides Klafke: marginália e contracultura

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ecos da modernidade: uma análise do discurso sobre o cinema ambulante em São Luís-MA

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise de cartas de leitor de revista de divulgação científica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento profissional em um grupo de trabalho: professores de matemática que ensinam por meio de softwares educacionais

Pós-graduação em Educação para a Ciência - FC

Transeuntes sobre ruínas: figurações alegóricas da casa familiar, no limiar de um certo exílio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A formação do leitor do ensino fundamental: as legendas cinematográficas

Given the pedagogical practices in respect of acts of reading in the current context of education institutions in primary education, it is clear that they are connected to decipher and not the search for meaning and understanding. In thinking about the use of new technologies that can contribute to the formation of the reader, it is believed that reading subtitles allows such training since it requires a quick read that does not cling to every word and attribution of meaning to monitor all the course of the film. This makes the children learn to read and make sense using the expertise of its cultural heritage. This research aimed to analyze the contribution of film subtitles to the formation of the reader from elementary school. Thus, students were invited, between the ages of six and ten years, with interest to see subtitled films, and they learn to read subtitles. The film sessions were held fortnightly at the school, in an adapted room. After the sessions, held group discussions to see what the problems in understanding the plot this paper presents data on the session of the film "Coração de Tinta". Children, assisted by the researchers could understand the story and learned to articulate their knowledge in situations of movies. The research is ongoing, but we can see that during the projection there are indications that they are able to read the subtitles, sometimes lose the timing of reading, but gradually evolve in the field of reading this kind of discourse.

Next-generation sequencing reveals large connected networks of intra-host HCV variants

Background: Next-generation sequencing (NGS) allows for sampling numerous viral variants from infected patients. This provides a novel opportunity to represent and study the mutational landscape of Hepatitis C Virus (HCV) within a single host.Results: Intra-host variants of the HCV E1/E2 region were extensively sampled from 58 chronically infected patients. After NGS error correction, the average number of reads and variants obtained from each sample were 3202 and 464, respectively. The distance between each pair of variants was calculated and networks were created for each patient, where each node is a variant and two nodes are connected by a link if the nucleotide distance between them is 1. The work focused on large components having > 5% of all reads, which in average account for 93.7% of all reads found in a patient. The distance between any two variants calculated over the component correlated strongly with nucleotide distances (r = 0.9499; p = 0.0001), a better correlation than the one obtained with Neighbour-Joining trees (r = 0.7624; p = 0.0001). In each patient, components were well separated, with the average distance between (6.53%) being 10 times greater than within each component (0.68%). The ratio of nonsynonymous to synonymous changes was calculated and some patients (6.9%) showed a mixture of networks under strong negative and positive selection. All components were robust to in silico stochastic sampling; even after randomly removing 85% of all reads, the largest connected component in the new subsample still involved 82.4% of remaining nodes. In vitro sampling showed that 93.02% of components present in the original sample were also found in experimental replicas, with 81.6% of reads found in both. When syringe-sharing transmission events were simulated, 91.2% of all simulated transmission events seeded all components present in the source.Conclusions: Most intra-host variants are organized into distinct single-mutation components that are: well separated from each other, represent genetic distances between viral variants, robust to sampling, reproducible and likely seeded during transmission events. Facilitated by NGS, large components offer a novel evolutionary framework for genetic analysis of intra-host viral populations and understanding transmission, immune escape and drug resistance.

The illuminist discourse of the digital divide: a critic to the Post-Fordist Informatic Mundaneum from Knoxville, Tennessee

This article discusses the project of the Information Society and the discourses that undergo it, as part of a political and ideological conception universalized by those countries that created and dominate computer technology, which is in turn is aligned with the Post-Fordist industrial capitalist order and its emphasis on economic accumulation and consumerism. We explain how information technology creates routines and legitimate social orders, taking for analyzes the case of the Clinton-Gore policy in the United States, when the discourse of the computer society was associated with the development and social welfare. This association is revealed in the speech made by Clinton in the city of Knoxville in year 1996. There we see the beginnings of the concern about the Digital Divide as a new form of "social disease" that prevents the passage to a better world, focused on productivity, accumulation and consumption in information-dense societies. This generates a clash between the industrial-graph-centric world and the oral-pre-industrial communities, as a result of attempting to transplant the institutional forms of the developed West. We explain the pillars of the new computerized order, and how they replaced previous epic narratives creating techno-deterministic or techno-phobic discourses in prejudice of more critical approaches. We identify the effects such deterministic discourses that connote the association between the Information Society, welfare and development, questioning the urgency of deploying this system at global level without profound critical discussion, clear goals focused on the benefit of the human beings, and the open participation of the users of the system.