Effect of the synthesis route on the phase formation and dielectric property in Ba,(Zr,Ti)O3-(Ba,Ca)TiO3 ceramics

Ceramics of (1−x)Ba(Zr0.2Ti0.8)O3–x(Ba0.7Ca0.3)TiO3 (BZT-BCT) are one of the promising candidates to substitute the lead zirconate titanate (PZT) ceramics. Some authors have named these compositions as Ba1-xCaxTi1-yZryO3 (BCZT) while others as BZT-BCT. That way, this terminology can lead the interpretation that ceramics of BCZT were prepared from precursor powders ``direct route” (carbonates, oxides, etc), while ceramics of BZT-BCT are synthesized by the mixture of BZT and BCT solid solutions in a “composite route.” Therefore, this paper aims to put light into the influence of the processing route on the properties of these compositions. The method used was the preparation of the ceramics by two routes: BCZT, named as a monophasic system, prepared by the direct route and BZT-BCT, designed polyphasic system, prepared by a composite route. The results show that the processing influences the structure, microstructure, dielectric properties, and phase transitions of the ceramics. These findings are particularly relevant for the discussion of the phase development and compositional complexity of these materials

Filtro ativo paralelo com controle digital de baixo custo

Este artigo descreve o desenvolvimento de um filtro ativo paralelo de baixo custo utilizado para a melhoria da qualidade de energia elétrica. O filtro permite a correção dinâmica do fator de potência e a compensação dinâmica dos harmônicos e da componente de sequência zero de corrente. O sistema de controle do filtro ativo é baseado na teoria p-q (teoria da potência instantânea), e foi implementado com um microcontrolador standard de 16 bits. Neste artigo a teoria p-q é apresentada de forma sucinta, o filtro ativo paralelo desenvolvido é descrito e são apresentados alguns resultados experimentais

Desarrollo de redes de período largo en fibras ópticas por métodos mecánicos

Las Redes de Período Largo (LPG - por sus siglas en ingles) grabadas en fibra óptica, poseen variaciones períodicas del índice de refracción del núcleo o de la cubierta de la fibra. Dichos periodos son de decenas o cientos de micrones y longitud total de algunos centímetros. Ellas acoplan modos co-propagantes del núcleo y de la cubierta de la fibra óptica, por esto sus resonancias sólo pueden medirse en el espectro de transmisión. A diferencia de las redes de Bragg, las LPG no reflejan luz, sino que se constituyen en filtros ópticos de atenuación en una región particular del espectro. En este trabajo, se utiliza un sistema mecánico para producir una perturbación periódica del índice de refracción en la fibra por efecto de la foto-elasticidad. Se realizaron pruebas experimentales en las que se lograron obtener redes en la zona de 1500 nm a 1600 nm, generando períodos de 500, 600 y 700 micrones, que resultan muy útiles para trabajos de investigación y para dispositivos de campo en las áreas de interés como comunicaciones y sensores

Shunt active filter for power quality improvement

This paper describes the development of a low cost shunt active power filter with digital control, which allows dynamic power factor correction and both harmonics and zero-sequence current compensation. The active filter controller is based on the instantaneous power theory (p-q theory) and was implemented using a standard 16 bits microcontroller. The p-q theory is introduced followed by the presentation of some active power filters topologies. Then a brief description of the implemented solution is made, including references to software tools used for simulation and system development. Experimental results are also presented, showing the good performance of the developed active filter

PAULO RÓNAI (1907-1992) E O "SUPLEMENTO LITERÁRIO" D' O ESTADO DE S. PAULO

ABSTRACT: This article aims to present partial results of study of texts that Paulo Rónai (1907-1992) published in the "Suplemento Literário" of the periodical O Estado de S. Paulo, which circulated from 1956 until 1974, as well as the analysis of the existing relation between its work as critical and the literary criticism of century XX. For this, the one hundred and twelve published texts, that deal with subjects as brazilian and foreign literature, translation, portuguese language and dictionaries, among others, and can be classified as articles, summaries, stories of trip and poem translation

Entre as Primeiras e as Outras estórias: uma análise da transcriação do sertão rosiano no filme de Pedro Bial

The discussions about the appropriation that cinema makes of literary works are not recent, neither can be considered as a passed or solved case. From this, the present work consists in the analysis of the transposition of some elements of the literary narrative of five short stories from Primeiras estórias (1962), by João Guimarães Rosa, to the film narrative Outras estórias (1999), directed by Pedro Bial. We took into consideration, mainly, the characterization of the characters; the organization, the exploitation and the intersection of the plots; besides the presence of the narrative voices. As a result of such analysis, we intend to demonstrate how the tension of several human dramas was transposed to the essentially cinematographic elements, to which the image, the photography, the plans and the framework, among others, collaborate with the narrative, as well as the resources used by Bial to re-create in cinematographic language Rosa’s universe.Os debates sobre a apropriação que o cinema faz de obras literárias não são recentes, tampouco podem ser considerados como um caso superado ou resolvido. A partir disso, o presente trabalho consiste na análise da transposição de alguns elementos da narrativa literária de cinco contos da obra Primeiras estórias (1962), de João Guimarães Rosa, para a narrativa fílmica Outras estórias (1999), dirigida por Pedro Bial, considerando-se, principalmente, a caracterização dos personagens; a estruturação, o aproveitamento e entrecruzamento dos enredos; além das presenças das vozes narrativas. Como resultado de tal análise, pretende-se demonstrar como a tensão dos diversos dramas humanos foi transposta para os elementos essencialmente cinematográficos, para os quais colaboram a narrativa pela imagem, a fotografia, os planos e o enquadramento, entre outros, bem como os apontamentos dos recursos que Bial utilizou para recriar em linguagem cinematográfica o universo rosiano

Biological activity of phenolic compounds from argentinean herbs infusions

Argentinean herbal infusions were studied for their beneficial biological properties and secondary metabolites content, such as phenolic compounds in order to find new natural products beneficial. The modifications of antihypertensive and antioxidant activities by the addition of commonly used additives (lemon, sugar and sweetener) were studied also. Ilex paraguaiensis infusion showed the highest concentration of phenolic compounds and flavonoid fraction, the supplementation with lemon juice increased the phenolic compound content. All infusion showed high DPPH radical scavenging assays and additives did not modify significantly this activity. The infusion of I. paraguaiensis presents the maximum viability reduction of Escherichia coli and Staphylococcus aureus and the herbs combination Lippia integrifolia-Ilex paraguaiensis was the most effective to reduce S. aureus and E.coli viability. The phenolic compounds concentration as well as the qualitative composition of each infusion plays an important role in the antimicrobial activity. Because the high correlation between the concentration of total phenolic compounds and antioxidant and antihypertensive activities, we can infer that the phenolic compounds are responsible for such activities. The results obtained allow us to propose the herbs studied as potential natural antioxidants and antihypertensive compounds that could be used in pharmaceutical and food industries.Fil: Rodriguez Vaquero, Maria Jose. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vallejo, Claudia Veronica. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aredes Fernández, Pedro Adrián. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

O médico diante da morte no pronto socorro

OBJETIVO: Analisar a forma como médicos, enquanto parte de um grupo sociocultural, lidam com diferentes tipos de morte, em um serviço de pronto socorro metropolitano. MÉTODOS: Trata-se de uma etnografia realizada em um dos maiores serviços de pronto socorro da América Latina. A coleta dos dados deu-se ao longo de nove meses de observação participante e entrevistas com 43 médicos de diferentes especialidades – 25 homens e 18 mulheres, entre 28 e 69 anos. RESULTADOS: À análise, guiada pelo modelo dos Signos, Significados e Ações, nota-se um vasto mosaico de situações e questões que medeiam o cuidado médico em uma unidade de pronto socorro. Os resultados apontaram que os médicos podem considerar uma morte mais difícil se comparada a outras, a depender de critérios: o etário; a identificação ou não com o paciente; as circunstâncias da morte e o questionamento médico quanto a sua responsabilidade no processo de morte. CONCLUSÕES: Para os médicos, nenhuma morte é fácil. Cada morte pode ser mais ou menos difícil, a depender de diferentes critérios que medeiam o cuidado médico em uma unidade de pronto socorro e revelam questões de ordem social, ética e moral das mais diversas.OBJECTIVE: To analyze how physicians, as part of a sociocultural group, handle the different types of death, in a metropolitan emergency service. METHODS: This is an ethnography carried out in one of the largest emergency services in Latin America. We have collected the data for nine months with participant observation and interviews with 43 physicians of different specialties – 25 men and 18 women, aged between 28 and 69 years. RESULTS: The analysis, guided by the model of Signs, Meanings, and Actions, shows a vast mosaic of situations and issues that permeate the medical care in an emergency unit. The results indicate that physicians may consider one death more difficult than another, depending on the criteria: age, identification or not with the patient, circumstances of the death, and medical questioning as to their responsibility in the death process. CONCLUSIONS: For physicians, no death is easy. Each death can be more or less difficult, depending on different criteria that permeate the medical care in an emergency unit, and it reveals different social, ethical, and moral issues

Phenolic compounds from wines as natural preservative of fish meat

The aims of this work were to investigate the antibacterial effect of phenolic compound combinations and total polyphenols of Argentinean red wines varieties against Escherichia coli ATCC 35218 and Listeria monocytogenes using commercial fish meat as model food. Rutin- quercetin combination and the three wine varieties produced cellular death of both bacteria on fish meat at 4 oC. Rutin-quercetin combination was effect even at 20 °C on fish meat. Clarified wines were inactive against both bacteria, indicating that the responsible of observed effect were the polyphenols of wines. The use of wine phenolic compounds as antibacterial agent could be used to prevent contamination and extend the shelf life of fish meat. A big finding of this work is the use of rutin–quercetin combination as preservative during the transport and conservation of fish meat to the fish market, which is an effective antibacterial agent even when there is an Interrupted in the cold chain.Fil: Rodriguez Vaquero, Maria Jose. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Microbiologia; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tucumán. Centro de Referencia Para Lactobacilos (i); Argentina;Fil: Aredes Fernández, Pedro Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tucumán. Centro de Referencia Para Lactobacilos (i); Argentina;Fil: Manca, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tucumán. Centro de Referencia Para Lactobacilos (i); Argentina