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Efeito da adição de Ni na microestrutura bainítica de um novo aço para roscas e cilindros de plastificação de polímeros
(Universidade Federal de São Carlos, 2019-09-02) Bacalhau, José Britti; Afonso, Conrado Ramos Moreira; https://lattes.cnpq.br/2176215981291453; https://lattes.cnpq.br/0047058242568049
Nitriding steels, such as DIN 1.8550, are used in the manufacture of screws and barrels for injection molding machines and plastic extruders. The hardening process of DIN 1.8550 occurs via water or oil quenching followed by tempering, and, it is common to experience distortions in bars subjected to severe temperature gradients. Residual stresses arising from cold straightening of steel bars and/or remaining from heat treatment cause, during the machining of components, problems related with geometric variations on screws and/or deviations in deep drilling of barrels. The objective of this work was the technological development of a new steel for screws and barrels, which has high dimensional stability since it allows hardening via still air cooling. It was produced four chemical compositions of low-carbon steels with variation only in the Ni content. Through dilatometry tests, it was verified that Ni delayed the transformation kinetics of ferrite and pearlite, and, favored the formation of bainite and martensite. In the studied bainitic steels, Ni also promoted the formation of lower bainite at the expense of upper bainite. The steel with 1.40% Ni presented a refined microstructure mainly composed of lower bainite, with homogeneous precipitation of alloy carbides in the bainitic ferrite lath. Steels with low Ni contents, 0.03% and 0.70%, exhibited a microstructure mainly composed of upper bainite, with alloy carbides precipitation in the boundaries of the bainitic ferrite packages. The 1.40% Ni steel showed the best combination of results regarding toughness, microstructure and hardenability, and, for that reason it was also produced in industrial scale. The steel hardening process, with in-line quenching via still air cooling, was industrially validated achieving the production of a very homogeneous bainitic steel. The work was completed with the full-scale manufacture of a screw and a barrel from extruder machines, therefore the technological development covered from laboratory phase to field tests.
Neural networks as an optimization tool for regression
(Universidade Federal de São Carlos, 2019-09-02) Coscrato, Victor Azevedo; Izbicki, Rafael; https://lattes.cnpq.br/9991192137633896; https://lattes.cnpq.br/4154241806264076
Neural networks are a tool to solve prediction problems that have gained much prominence recently. In general, neural networks are used as a predictive method, that is, their are used to estimate a regression function. Instead, this work presents the use of neural networks as an optimization tool to combine existing regression estimators in order to obtain more accurate predictions and to fit local linear models more efficiently. Several tests were conducted to show the greater efficiency of these methods when compared to the usual ones.
Representação das mulheres no melodrama contemporâneo: uma análise feminista sobre Grey’s Anatomy
(Universidade Federal de São Carlos, 2019-09-02) Jangrossi, Virgínia; Adamatti, Margarida Maria; https://lattes.cnpq.br/2629005451704968; Costa, Flávia Cesarino; https://lattes.cnpq.br/1653890782950111; https://lattes.cnpq.br/9091506432459911
This thesis aims to analyze the structure of Grey’s Anatomy (Shonda Rhimes, ABC, 2005 –) and examine how the television series portrays themes associated with female subjects, such as the myth of romantic love, sexual freedom, motherhood, abortion, and gender inequalities in the work environment. Drawing from the feminist and the melodramatic theories as well as American television studies, this thesis scrutinizes how a series that targets mass culture incorporates ambiguities while portraying these themes. It also analyzes the impact these narrative fissures might have on female empowerment.
Variação morfológica e molecular da espécie Dendropsophus minutus (Amphibia, Anura, Hylidae) em sua área de ocorrência no Brasil
(Universidade Federal de São Carlos, 2019-09-02) Melo, Suélen Helena Martins; Haddad, Célio Fernando Baptista; https://lattes.cnpq.br/0458077399058762; Garavello, Júlio César; https://lattes.cnpq.br/2778105126670170; https://lattes.cnpq.br/1946304243808936
Dendropsophus minutus is a widely distributed hyilid in the Neotropical Region that have significant morphological variation along its area of occurrence. Recent molecular studies revealed high diversity of clades under the name Dendropsophus minutus. By this reason, we sought to identify patterns of polymorphisms in Dendropsophus minutus along the species distribution through the different Brazilian phytophysiognomies: Amazon, Caatinga, Cerrado, Atlantic Forest and Pampa. We studied the morphological variation in Dendropsophus minutus by analyzing the morphometry and dorsal color pattern of males housed in Brazilian herpetological collections. Additionally, we amplified the 16S mitochondrial gene fragment to allocate morphometrically analyzed specimens into the phylogenetic tree from the literature. Even though there are sympatrics morphotypes in Dendropsophus minutus, we observe the absence of the dorsal pattern “bivittata” form in Northern Brazil, while the “minuta” pattern was not recorded in the South of the country. This study did not distinguish morphometrically the species through its distribution in Brazil; however, significant molecular differentiation in Amazonian specimens currently identified as Dendropsophus minutus was described, that are strongly related to samples of the taxon Dendropsophus goughi.