Development of a four phase floating interleaved boost converter for photovoltaic systems

This paper explores the advantages of the Floating Interleaved Boost Converter, particularly with regards to solar photovoltaic power systems. This converter offers improved efficiency and voltage gain, while having lower input current ripple than other DC-DC boost converters. An analog linear feedback controller was developed, and adapted for discrete control. Two Maximum Power Point Tracking methods were explored, and their performances were evaluated in simulation. An experimental prototype was developed and demonstrated. The results show that this is a promising converter topology with many potential benefits for solar power applications

How equal is equality? Discussions about same-sex marriage in Portugal

In Portugal, public and political discussions about same-sex marriage have been going on since the 1990s. In 2010, same-sex marriage was legalized under intense dispute since it excludes same-sex couples from adoption and reproductive rights. During parliamentary debates, political parties and civil organizations linked to the Catholic Church resorted to conflicting ideas of ‘equality’ and ‘difference’ to advance their claims. In this article, we analyse the contents of petitions, bills and parliamentary proceedings concerning the legal recognition of same-sex unions, highlighting the presence of conflicting notions of equality linked to pervasive beliefs about the inadequacy of homo-erotic desire and practices

Multivariate GR&R through factor analysis

Several measurement tasks present multivariate nature. In the cases with quality characteristics highly correlated within groups, but with a relatively small correlation between groups, the available multivariate GR&R methods are not suitable to provide a correct interpretation of the results. The present work presents a new multivariate GR&R approach through factor analysis. Factor analysis is a multivariate statistical method which focuses on the explanation of the covariance structure of the data. Through orthogonal rotation of the factors a suitable structure can be achieved with loadings easy to relate the variables to the factors. The proposed multivariate GR&R method through factor analysis is described and applied in the quality evaluation of holes obtained through helical milling process of AISI H13 hardened steel. The method succeeded in achieving a simple structure, with one factor related to the roughness outcomes and other related to the roundness ones, simplifying the gage capability evaluation.publishe