Controle Adaptativo Robusto para Filtros Ativos de Potência Paralelo

Conventional control strategies used in shunt active power filters (SAPF) employs real-time instantaneous harmonic detection schemes which is usually implements with digital filters. This increase the number of current sensors on the filter structure which results in high costs. Furthermore, these detection schemes introduce time delays which can deteriorate the harmonic compensation performance. Differently from the conventional control schemes, this paper proposes a non-standard control strategy which indirectly regulates the phase currents of the power mains. The reference currents of system are generated by the dc-link voltage controller and is based on the active power balance of SAPF system. The reference currents are aligned to the phase angle of the power mains voltage vector which is obtained by using a dq phase locked loop (PLL) system. The current control strategy is implemented by an adaptive pole placement control strategy integrated to a variable structure control scheme (VS-APPC). In the VS-APPC, the internal model principle (IMP) of reference currents is used for achieving the zero steady state tracking error of the power system currents. This forces the phase current of the system mains to be sinusoidal with low harmonics content. Moreover, the current controllers are implemented on the stationary reference frame to avoid transformations to the mains voltage vector reference coordinates. This proposed current control strategy enhance the performance of SAPF with fast transient response and robustness to parametric uncertainties. Experimental results are showing for determining the effectiveness of SAPF proposed control system

Estratégia de controle robusto para filtro ativo paralelo sem detecção de harmônicos de correntes

Conventional control strategies used in shunt active power filters (SAPF) employs real-time instantaneous harmonic detection schemes which is usually implements with digital filters. This increase the number of current sensors on the filter structure which results in high costs. Furthermore, these detection schemes introduce time delays which can deteriorate the harmonic compensation performance. Differently from the conventional control schemes, this paper proposes a non-standard control strategy which indirectly regulates the phase currents of the power mains. The reference currents of system are generated by the dc-link voltage controller and is based on the active power balance of SAPF system. The reference currents are aligned to the phase angle of the power mains voltage vector which is obtained by using a dq phase locked loop (PLL) system. The current control strategy is implemented by an adaptive pole placement control strategy integrated to a variable structure control scheme (VS¡APPC). In the VS¡APPC, the internal model principle (IMP) of reference currents is used for achieving the zero steady state tracking error of the power system currents. This forces the phase current of the system mains to be sinusoidal with low harmonics content. Moreover, the current controllers are implemented on the stationary reference frame to avoid transformations to the mains voltage vector reference coordinates. This proposed current control strategy enhance the performance of SAPF with fast transient response and robustness to parametric uncertainties. Experimental results are showing for determining the effectiveness of SAPF proposed control system

Estratégias de relativização no português brasileiro e implicações para o ensino: o caso das cortadoras

This work consists of a cognitive-functional approach of relativization strategies of Brazilian Portuguese (BP), this is, standard relatives (with preposition or without it) and non-standard relatives (copiadora and the deletion pattern), and it emphasizes the last one. We investigate the use of the relative construction strategies in spoken and written texts produced by speakers from different school levels in a specific situation: a face-to-face interviewing. Our database is the corpora Discurso & Gramática: a língua falada e escrita na cidade do Natal e a língua falada e escrita na cidade do Rio de Janeiro. We contrast the use of the standard relative to the deletion pattern in prepositional context, by considering cognitive, social and interactional motivations for the use of the deletion pattern instead of the standard one. Our research leads us to verify that the deletion pattern is fixing as the preferred relativization strategy in prepositional contexts, and, in this way, it brings out a grammaticalization process in working. For this reason, we propose to take this relative construction as a common way to structure a relative clause, in the same way we take the standard pattern. Finally, we discuss the treatment of questions related to the processes of teaching and learning of Portuguese language and some suggestions are given in terms of class activities. We expect that the development of this research may give both support for the Portuguese teachers and suggestions to improve the teaching and learning process of Portuguese language, contributing in special to the treatment of the syntax of complex clauses.

A intervenção do poder judiciário no acesso a medicamentos no Rio Grande do Norte: uma análise sob a ótica das políticas nacionais de medicamento e de assistência farmacêutica

The present study aimed to evaluate the inclusion of the principles of the National Medicines Policy - PNM and the Pharmaceutical assistance - PNAF in the prosecution of lawsuits involving medicines. To fulfill this necessity , data collection was performed on the website by the Tribunal Rio Grande do Norte - TJ RN ( Rio Grande do Norte Court) , in 2012 . It was obtained 115 judgments, which were analyzed in order to generate Monitoring Indicators from lawsuits and conduct content analysis proposed by Bardin (2006). The results showed that : a) 100 % of the decisions were favorable to the author , b) 76 % of decisions were requests by the trade name of the drug , c) only one drug (eculizumabe) had not granted by ANVISA , d) 36 % of drugs were present in the list of standard medicines in SUS , 16 % of primary care block and 20 % of specialized component , e) 76 % of the decisions presented the request of at least 01 non-standard medicine. With regard to decentralization of PNM and PNAF we observed a commitment to this principle at judicial decisions, to see that municipalities and states are often forced to buy medicines of responsibility from another federal entity or other tertiary units as CACONs and UNACONS. The content analysis revealed that the argument from the judges used when you utter their decisions was that the right to health is recognized by Brazilian law as a fundamental right and should be guaranteed by the State for all its citizens. So, health is more than budgetary constraints of federal entities, which are severally liable for lawsuits , regardless the medication requested belongs or not to a particular block of a pharmaceutical assistance funding. Given these data, it is observed that there are gaps in the judgment when it comes to the insertion of the words and principles of PNM and PNAF, creating then the need for greater dialogue between the executive and judicial, so that they may consider relevant the effectiveness and application of such principles to minimize the negative consequences of the phenomenon of health judicialisation. Keywords: Judicialisation, Medicines, Public Policy, Pharmaceutical Care

Estudos de sorção de um corante aniônico modelo em partículas de quitosana reticulada

Textile activity results in effluents with a variety of dyes. Among the several processes for dye-uptaking from these wastewaters, sorption is one of the most effective methods, chitosan being a very promising alternative for this end. The sorption of Methyl Orange by chitosan crosslinked particles was approached using equilibrium and kinetic analyses at different pH s. Besides the standard pseudo-order analysis normally effectuated (i.e. pseudo-first-order and pseudo-second-order), a novel approach involving a pseudo-nth-order kinetics was used, nbeing determined via non-linear regression, using the Levenberg-Marquardt method. Zeta potential measurements indicated that electrostatic interactions were important for the sorption process. Regarding equilibrium experiments, data were well fitted to a hybrid Langmuir-Freundlich isotherm, and estimated Gibbs free energy of adsorption as a function of mass of dye per area of chitosan showed that the process of adsorption becomes more homogeneous as the pH of the continuous phase decreased. Considering the kinetics of sorption, although a pseudo-nth-order description yielded good fits, a kinetic equation involving diffusion adsorption phenomena was found to be more consistent in terms of a physicochemical description of the sorption process