Identification of transmission line parameters from temporal measurements of currents and voltages in their terminals: Influence oh the length line

The objective of this paper is to show a methodology to estimate transmission line parameters. The method is applied in a single-phase transmission line using the method of least squares. In this method the longitudinal and transversal parameters of the line are obtained as a function of a set of measurements of currents and voltages (as well as their derivatives with respect to time) at the terminals of the line during the occurrence of a short-circuit phase-ground near the load. The method is based on the assumption that a transmission line can be represented by a single circuit π. The results show that the precision of the method depends on the length of the line, where it has a better performance for short lines and medium length. © 2012 IEEE.

Growth mechanism and photocatalytic properties of SrWO4 microcrystals synthesized by injection of ions into a hot aqueous solution

This paper reports our initial research to obtain SrWO4 microcrystals by the injection of ions into a hot aqueous solution and their photocatalytic (PC) properties. These microcrystals were structurally characterized by X-ray diffraction (XRD), Rietveld refinements and Fourier transform (FT)-Raman spectroscopy. The shape and average size of these SrWO 4 microcrystals were observed by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). In addition, we have investigated the PC activity of microcrystals for the degradation of rhodamine B (RhB) and rhodamine 6G (Rh6G) dyes. XRD patterns, Rietveld refinement data and FT-Raman spectroscopy confirmed that SrWO4 microcrystals have a scheelite-type tetragonal structure without deleterious phases. FT-Raman spectra exhibited 12 Raman-active modes in a range from 50 to 1000 cm-1. FE-SEM and TEM images suggested that the SrWO4 microcrystals (rice-like - 95%; star-, flower-, and urchin-like - 5%) were formed by means of primary/secondary nucleation events and self-assembly processes. Based on these FE-SEM/TEM images, a crystal growth mechanism was proposed and discussed in details in this work. Finally, a good PC activity was first discovered of the SrWO4 microcrystals for the degradation of RhB after 80 min and Rh6G after 50 min dyes under ultraviolet-light, respectively. © 2012 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder.

Use of grape polyphenols against carcinogenesis: Putative molecular mechanisms of action using in vitro and in vivo test systems

Polyphenols are present in foods and beverages and are related to sensorial qualities such as color, bitterness, and astringency, which are relevant in wine, tea, grape juice, and other products. These compounds occur naturally in forms varying from simple phenolic acids to complex polymerized tannins. Thus, it is reasonable to expect that grape-derived products elaborated in the presence of skins and seeds, such as wine and grape juice, are natural sources of flavonoids in the diet. Carcinogenesis is a multistep process that is characterized by genetic, epigenetic, and phenotypic changes. With increasing knowledge of these mechanisms, and the conclusion that most cases of cancer are preventable, efforts have focused on identifying the agents with potential anticancer properties. The use of grape polyphenols against the carcinogenesis process seems to be a suitable alternative for either prevention and/or therapeutic purposes. The aim of this article is to show the molecular data generated from the use of grape polyphenols against carcinogenesis using in vivo and in vitro test systems. © Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition.

Investing better in order to invest more. Finance and management of education in Latin America and the Caribbean

Includes bibliography

O romance-projeto: um estudo de Lucinde (1799), de Friedrich Schlegel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A escrita como arma: uma análise do pensamento social na literatura marginal

Pós-graduação em Ciências Sociais - FFC

Review of the implementation of the Cairo Programme of Action in the Caribbean (1994-2004): achievements and constraints

Includes bibliography

Conto de escola: uma metáfora da sociedade

Pós-graduação em Educação - IBRC

Educação e cidadania: um estudo sobre os fundamentos filosóficos que orientam a formação para a cidadania nos Parâmetros Curriculares Nacionais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Criteria for the efficient coordination of the activities for data collection and the design of instruments for mapping and data collection applicable to countries of the Caribbean

Includes bibliography

Frankenstein: uma releitura do mito de criação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Arte e ética em The Bell de Iris Murdoch

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Da feminilidade oitocentista

Pós-graduação em História - FCHS

O Paraguai de Roa Bastos: história e crítica social

Pós-graduação em História - FCLAS

Nacionalismo, cosmopolitismo e afrancesamento em Mon coeur balance e Leur âme, de Oswald de Andrade e Guilherme de Almeida

Pós-graduação em História - FCLAS