66 research outputs found

    Damage localization in laminated composite plates using mode shapes measured by pulsed TV holography

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    Three methods for the damage localization of impact damage in laminated composite plates, based on their vibrational characteristics, are presented in this paper. These methods use double pulse TV holography with acoustic excitation for mode shapes acquisition and the differences in translations, rotations and curvatures. The rotations and curvatures are obtained by numerical differentiation of mode shapes translations using a differentiation/smoothing technique. The methods are applied to a carbon fiber reinforced epoxy rectangular plate, free in space, subjected to two cases of impact damage. It is shown that the method based on curvatures allows the localization of both cases of damage, which can be undetected by visual, X-ray or C-scan inspections. The best localizations are achieved by selecting and applying the method to the most changed mode.Three methods for the damage localization of impact damage in laminated composite plates, based on their vibrational characteristics, are presented in this paper. These methods use double pulse TV holography with acoustic excitation for mode shapes acquisition and the differences in translations, rotations and curvatures. The rotations and curvatures are obtained by numerical differentiation of mode shapes translations using a differentiation/smoothing technique. The methods are applied to a carbon fiber reinforced epoxy rectangular plate, free in space, subjected to two cases of impact damage. It is shown that the method based on curvatures allows the localization of both cases of damage, which can be undetected by visual, X-ray or C-scan inspections. The best localizations are achieved by selecting and applying the method to the most changed mode

    Damage localization in laminated composite plates using double pulse-electronic holographic interferometry

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    One method for the damage localization of impact damage in laminated composite plates, based on their vibrational characteristics, is presented in this paper. This method uses double pulse-electronic holographic interferometry for mode shapes acquisition and the differences in curvatures. The rotations and curvatures are numerically obtained. The method is applied to a carbon fibre reinforced epoxy rectangular plate, free in space, subjected to two cases of impact damage. It is shown that the method based on curvatures allows for the localization of both cases of damage, which can be undetected by visual, X-ray or C-Scan inspections. The best localizations are achieved by selecting and applying the method to the most changed mode

    Transphobia and gender identity: Social representations of trans women from brazil and colombia [Transfobia e identidade de gĂȘnero: RepresentaçÔes sociais de mulheres trans do brasil e colĂŽmbia]

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    The present research aimed to identify and discuss the social representations of trans women related to gender identity and transphobia in Brazil and Colombia. In this study participated 43 Trans women, 22 from Brazil, aged between 18 and 55 years (M=29.09, SD=8.53) and 21 from Colombia, aged between 21 and 41 years (M=28.19, SD=7.63). This study adopted a qualitative approach in which semi-structured interviews were used. The data were analyzed by the Iramuteq software, which identified the social representations in classes. The results showed what the participants understood about transphobia and how they regarded their experiences with this gender identity. The participants presented negative social representations, aiming at their personal experiences related to their social context. Themes related to violence, discrimination, prejudice, denial of rights and family support emerged from both the Brazilian and Colombian sample. Implications for TranŽs quality of life are discussed. © 2021, Associacao Brasileira de Pos - Graduacao em Saude Coletiva. All rights reserved

    Diversity and Genetic Relationship of Free-Range Chickens from the Northeast Region of Brazil

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    In this study, we aimed to evaluate the genetic diversity within and among chicken breeds from the northeast region of Brazil (states of Bahia and PiauĂ­) using microsatellite markers. In addition, we assessed the identity and genetic relationships of chickens from Europe, Africa, and South America, as well as their influence on the formation of the Brazilian breeds. A total of 25 microsatellite markers and a panel containing 886 samples from 20 breeds (including the Brazilian chickens) were used in this study. Different statistical parameters were used to estimate the genetic diversity and relationship among the genetic groups studied. Our study indicates that the Brazilian Creole chickens have high genetic variability. The results show that chickens reared in the states of Bahia and PiauĂ­ could have originated from different ancestors. The Brazilian breeds studied have an evolutionary relationship with chickens from Portugal, Nigeria, Chile, and Spain. Our results will contribute directly to the conservation and recognition of Brazilian Creole chicken breeds and provide a solid basis for the demonstration of their genetic identity and genetic conservation of American Creole chicken populations
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