A programme to determine the exact interior of any connected digital picture

Region filling is one of the most important and fundamental operations in computer graphics and image processing. Many filling algorithms and their implementations are based on the Euclidean geometry, which are then translated into computational models moving carelessly from the continuous to the finite discrete space of the computer. The consequences of this approach is that most implementations fail when tested for challenging degenerate and nearly degenerate regions. We present a correct integer-only procedure that works for all connected digital pictures. It finds all possible interior points, which are then displayed and stored in a locating matrix. Namely, we present a filling and locating procedure that can be used in computer graphics and image processing applications

Residual Stresses Induced by Dry and Cryogenic Cooling during Machining of AZ31B Magnesium Alloy

The major challenge of the Mg alloys has been their unsatisfactory corrosion resistance, which can be enhanced by improving the surface integrity. Cryogenic machining, where liquid nitrogen was used during machining, has been reported to improve the surface integrity of machined components, including compressive residual stresses. This paper analyses the influence of several cutting parameters, tool geometry and cryogenic conditions on the surface and subsurface residual stresses distribution

Residual Stresses in Machining of AISI 52100 Steel under Dry and Cryogenic Conditions: A Brief Summary

17th Conference on Material Forming (ESAFORM) - FinlandResidual stress is one of the most important surface integrity parameter that can significantly affect the service performance of a mechanical component, such as: contact fatigue, corrosion resistance and part distortion. For this reason the mechanical state of both the machined surface and subsurface needs to be investigated. Residual stress induced by dry and cryogenic machining of hardened AISI 52100 steel was determined by using the X-ray diffraction technique. The objective was to evaluate the influence of the tool cutting edge geometry, workpiece hardness, cutting speed, microstructural changes and cooling conditions on the distribution of the residual stresses in the machined surface layers. The results are analysed in function of the thermal and mechanical phenomena generated during machining and their consequences on the white layer formation

Resenha do Santana (2015) : Quando me descobri negra

Obra ressenyada: Bianca SANTANA, Quando me descobri negra. São Paulo: SESI-SP., 2015

Nitrogênio e enxofre no capim-Marandu: relação entre suprimento e concentração nos tecidos foliares

In order to better assess the nutritional status of forage grasses there has been an increasing interest in studying the nutrient concentrations present in different parts of plant shoot. The aim of this work was to evaluate the nitrogen and sulphur concentrations in leaf tissues of Brachiaria brizantha cv. Marandu grown in nutrient solutions with combined rates of both nitrogen and sulphur. An experiment was conducted in a greenhouse during the Spring season in Piracicaba-SP, Brazil, using ground quartz as substrate. A fractionated 5² factorial design was used, with 13 combinations of nitrogen and sulphur rates in the solutions, in mg L-1, as follows: 14 and 3.2; 14 and 32; 14 and 80; 126 and 12.8; 126 and 64; 210 and 3.2; 210 and 32; 210 and 80; 336 and 12.8; 336 and 64; 462 and 3.2; 462 and 32, and 462 and 80. The experimental units were set in a randomized block design, with four replications. Plants were harvested twice. Emerging leaves, recently expanded lamina and mature lamina were sampled separately at each harvest time. In these three types of tissues the nitrogen concentration was closely related to the nitrogen supply in the solution, whereas the sulphur concentration, N:S ratio and chlorophyll meter (SPAD) readings depended upon the supply of both nitrogen and sulphur. Mature lamina did not relate well to the changing in sulphur supply. To properly assess the nitrogen and sulphur concentrations, N:S ratio and SPAD readings for the Marandu grass, the two recently expanded lamina were the best tissues to indicate the availability of both nitrogen and sulphur in the nutrient solution.Há clara demanda de conhecimento da concentração de nutrientes nos componentes da parte aérea das plantas para subsidiar a avaliação do estado nutricional das gramíneas forrageiras. Para contribuir nessa área, objetivou-se avaliar as concentrações de nitrogênio e enxofre em tecidos foliares da Brachiaria brizantha cv. Marandu, cultivada em solução nutritiva com doses combinadas de nitrogênio e de enxofre. Foi conduzido um experimento em casa de vegetação no período da primavera, em Piracicaba-SP, empregando sílica como substrato. Utilizou-se um esquema fatorial 5² fracionado, com 13 combinações das doses de nitrogênio e enxofre na solução, em mg L-1: 14 e 3,2; 14 e 32; 14 e 80; 126 e 12,8; 126 e 64; 210 e 3,2; 210 e 32; 210 e 80; 336 e 12,8; 336 e 64; 462 e 3,2; 462 e 32 e 462 e 80. As unidades experimentais foram distribuídas segundo o delineamento de blocos ao acaso, com quatro repetições. Foram realizados dois cortes nas plantas e, em cada um, foram amostradas as folhas emergentes, as lâminas de folhas recém-expandidas e as lâminas de folhas maduras. Nos três tipos de tecidos amostrados, a concentração de nitrogênio foi estritamente relacionada ao suprimento de nitrogênio, enquanto a concentração de enxofre, a relação N:S e o valor SPAD dependeram do fornecimento tanto de nitrogênio como de enxofre. As lâminas de folhas maduras não refletiram a variação no suprimento de enxofre. Na avaliação das concentrações de nitrogênio e de enxofre, da relação N:S e do valor SPAD no capim-Marandu as lâminas de folhas recém-expandidas foram as melhores indicadoras da disponibilidade de nitrogênio e enxofre no meio de crescimento

Educação antirracista no contexto político e acadêmico: tensões e deslocamentos

The purpose of this article is to discuss the actions of social movements, particularly the Brazilian black movement, and Afro-Peruvian social movements in Peru targeting anti-racist education. Attention is drawn to the contemporary discussion about race and anti-racism in the production of knowledge and in the public educational policies in Brazil and in Peru. In addition to an approach to the use of ethnic-racial categories in census contexts in both countries. A comprehensive way of addressing the issue starts with thinking about the dimensions involved in the phenomenon subject to measurement and how they are operationalized by the State and by society. This work is based on the theoretical perspective of contemporary authors covering ethnic-racial relations and educational inequalities. In methodological terms, Teun Van Dijk´s critical analysis of discourse is utilized. The first part presents a discussion about the social construction of race under the standards of domination and power. The second part proposes a discussion about ethnic-racial categories in the census contexts of the Brazilian and the Peruvian societies. It is understood that such categories may be culturally and politically elaborated drawing from complex historical processes. The third part addresses reflections on the emergence of some anti-racist education in the contemporary societies with an emphasis on Brazil and Peru. The article concludes with the idea that it is essential to dialogue with alternatives that have been formulated by the black social movements, especially in the Brazilian and Peruvian societies, which raise questions regarding the production and dissemination of the Eurocentric knowledge, unveiling racism and taking power relations, especially those occurring in the educational realm, into consideration.Este artigo tem como objetivo discutir ações de movimentos sociais, em particular do movimento negro brasileiro, e movimentos sociais afroperuanos no Peru visando uma educação antirracista. Procura-se chamar a atenção sobre a discussão contemporânea que aborda raça e antirracismo na produção de conhecimento e nas políticas públicas educacionais no Brasil e Peru, além de uma aproximação do uso de categorias étnico-raciais em contextos censitários destes países. Um modo abrangente de abordar a questão inicia-se por pensar quais as dimensões implicadas no fenômeno sujeito a mensuração, e como as mesmas seriam operacionalizadas pelo Estado e sociedade. Este trabalho fundamenta-se na perspectiva teórica de autores contemporâneos sobre relações étnico-raciais e desigualdades educacionais. No campo metodológico utiliza-se a proposta da análise crítica do discurso, de Teun Van Dijk. A primeira parte apresenta uma discussão sobre a construção social da raça nos padrões de dominação e poder. Na segunda parte propõe-se uma discussão sobre categorias étnico-raciais nos contextos censitários da sociedade brasileira e peruana. Apreende-se que tais categorias podem ser cultural e politicamente elaboradas a partir de processos históricos complexos. A terceira parte aborda reflexões sobre a emergência de uma educação antirracista nas sociedades contemporâneas com ênfase para o Brasil e Peru. Conclui-se que é fundamental dialogar com alternativas que têm sido formuladas pelos movimentos sociais negros, em particular nas sociedades brasileira e peruana, que questionam a produção e disseminação do conhecimento eurocêntrico, desvelando o racismo, e considerando as relações de poder, em especial no âmbito educacional