Influência da lubrirrefrigeração na qualidade superficial de metais retificados

Na fabricação de componentes mecânicos precisos, que necessitam de alta resistência mecânica e ao desgaste, utiliza-se o processo de retificação, para conferir o acabamento final desejado e, também, para eliminar as deformações ocorridas durante a têmpera do aço. No entanto, as condições de retificação devem ser adequadas, para que não sejam introduzidas falhas na peça. Novos conceitos de lubrificação e refrigeração, para o processo de retificação, estão sendo pesquisados, de forma a diminuir os custos e os danos ambientais causados pelos fluidos de corte. Nesse trabalho, é analisada a influência das técnicas de mínima quantidade de lubrificante (MQL), refrigeração otimizada e refrigeração convencional, com diferentes vazões e velocidade de aplicação do fluido de corte, na qualidade das peças produzidas com aço ABNT 4340 endurecido, no processo de retificação cilíndrica externa de mergulho com a utilização de rebolos de CBN. O Aço ABNT 4340 apresenta várias aplicações industriais, sendo considerado de uso aeronáutico devido, sua alta resistência mecânica sem aumentar o peso dos componentes que o utilizam. A análise da qualidade das peças foi realizada com a verficação das rugosidades e com a análise de microscopias eletrônicas de varredura. Verificou-se, ainda, a força tangencial de corte. em relação às diferentes formas de aplicação do fluido de corte, notou-se o melhor desempenho da aplicação otimizada, para maiores velocidades, mostrando a eficiência do bocal utilizado. O processo otimizado e o processo MQL foram capazes de manter a integridade superficial das peças produzidas. Exceção somente para a condição MQL com vazão de fluido de corte de 40ml/h, que produziu trincas e queima superficial. Rebolos com baixa concentração de CBN, conseqüentemente mais baratos, proporcionaram bons resultados, quando associados com técnicas mais eficientes de aplicação de fluido de corte apresentando desgaste reduzido.

Adult attachment style and cortisol responses in women in late pregnancy

Suporte financeiro e não financeiro da Maternidade Alfredo da Costa, Lisboa, Portugal

Population structure and growth of the hermit crab Pagurus brevidacylus (Anomura : Paguridae) from the northern coast of São Paulo, Brazil

The hermit crab Paguras brevidactylus (Crustacea: Anomura: Paguridea) from the infralittoral area of Anchieta Island, Ubatuba, was characterized by population Structure (size, sex ratio, reproduction and recruitment) and growth. Animals were collected monthly during 1999 by SCUBA diving. A total of 1525 individuals was collected (633 males and 892 females), 695 of them were ovigerous females. Overall sex ratio was 0.7:1 in favour of females. The crabs showed a unimodal distribution with males significantly larger than females. Ovigerous females were collected during all months and in high percentages from 1.0 mm of shield length, demonstrating intense and Continuous reproduction. The longevity was approximately 24 months for males and 18 for females, which showed larger growth rate and reached sexual maturity earlier (two months) than males. The low number of males in this Population may be due to the longer life span. Moreover, the sexual dimorphism favours males during the intra- and interspecific fights by shell, food, reproduction and territory. Females demonstrated a short life cycle and intense reproduction.

Biodiversidade marinha da costa sul de Sagres. Identificação e caracterização de biótopos

A necessidade de obter informação georreferenciada de habitats marinhos da costa portuguesa foi o principal motivador para a realização deste estudo. Sagres é reconhecido como sítio de importância comunitária, o que lhe confere redobrado interesse do ponto de vista da conservação da biodiversidade. Este estudo pretende colmatar parte do desconhecimento da biodiversidade e da distribuição dos habitats da zona subtidal de Sagres. A área de estudo situa-se na extremidade Sul entre a ponta de Sagres e a praia da Ingrina, entre a zona costeira e a batimétrica dos 86 metros. Os objectivos propostos foram alcançados pela realização de censos visuais através de mergulho subaquático com escafandro autónomo nos recifes rochosos costeiros, arrastos de vara na caracterização da epifauna e através da utilização de draga Van Veen na caracterização da infauna do substrato móvel. A área foi genericamente caracterizada por apresentar reduzida cobertura recifal e de baixa complexidade estrutural. O recife encontra-se sobretudo numa área entre a costa e a batimétrica dos 25 metros e outra para além da batimétrica dos 60 metros e por isso de difícil avaliação por métodos convencionais. No recife rochoso costeiro foi possível identificar três habitats de características particulares, nomeadamente áreas junto às falésias, constituídas por blocos de grandes dimensões, áreas de recife com pouco relevo no meio de áreas com alguma gravilha ou pedras roladas, e ainda, grutas e cavernas de grandes dimensões. O substrato móvel existente foi, por sua vez, caracterizado pela sua composição homogénea em toda a sua extensão.

Supressão do ruído de rolamento superficial utilizando a transformada Curvelet

Among the many types of noise observed in seismic land acquisition there is one produced by surface waves called Ground Roll that is a particular type of Rayleigh wave which characteristics are high amplitude, low frequency and low velocity (generating a cone with high dip). Ground roll contaminates the relevant signals and can mask the relevant information, carried by waves scattered in deeper regions of the geological layers. In this thesis, we will present a method that attenuates the ground roll. The technique consists in to decompose the seismogram in a basis of curvelet functions that are localized in time, in frequency, and also, incorporate an angular orientation. These characteristics allow to construct a curvelet filter that takes in consideration the localization of denoise in scales, times and angles in the seismogram. The method was tested with real data and the results were very good

Descrição do ciclo gametogênico do ouriço-branco, Tripneustes ventricosus (Lamarck, 1816), no Arquipélago de Fernando de Noronha PE, Brasil

Sea urchins are common benthic organisms on coastal ecosystems of tropical and temperate shallow waters. The impact of sea urchins populations in shore communities is density-dependent, and therefore, knowledge of the life history of these animals is important to understand these interactions. Between 2000 and 2005 a population boom of Tripneustes ventricosus was observed in the Fernando de Noronha Archipelago. In 2004 a research program was started to monitor the population dynamics of T. ventricosus in the archipelago, when it noted a lack of basic information on the biology and reproduction of this species, despite its broad geographic distribution and economic importance in parts of its occurrence. In this context, this work focuses on the reproductive biology of T. ventricosus with emphasis on the description of the gametogenic stages. Between December 2006 and July 2007, ten urchins were collected by snorkeling in two sites of the archipelago, totaling 120 individuals. Gametogenic stages were described for both sexes through microscopic analysis, and were defined as: Recovery, Growing, Premature, Mature and Spawning. Results showed increasing in Gonad index throughout of months of sampling and suggest that the reproductive cycle of the species in the archipelago is annual

Distribuição e abundância da malacofauna epibentônica no Parracho de Maracajaú, RN, Brasil

The mollusks present a great taxon variety and life habits in coral reefs being good environmental indicators. It is important to know the distribution pattern of the mollusks and the processes that influence it, so that disturbances in sea ecosystems could be monitored. The present study aims to accomplish the inventory and distribution of epibenthic mollusks in the Parracho of Maracajaú. 23 sites in different habitats of the Parracho were settled: 11 in the reef habitat, 3 in the sandy bottom and 9 in the seagrass bed. Qualitative and quantitative samplings have been done through snorkeling and scuba diving. Three band transects (10m²) were sampled in each site and the data were obtained to each m² of the transect, where the species were counted and the environmental variables (rugosity and recovery of the substratum) were valued. The data were submitted to multivariate analyses in order to find possible distribution patterns that could be associated to the substratum variables. The diversity indexes were calculated for each reef sites and compared with each other. A number of 46 species were registered. The reef habit at should to be the richnest area while the sandy bottom was poorest one. In the reef habitat, the mollusks were associated to rugosity and recovering of frondose algae and zoanthids, while for the seagrass bed, the animals exhibited a richness variation associated to the muddy and sandy sediment. There were found 3 species economically explored, what requires an appropriate management for the maintenance and conservation of the area resources in a sustainable way

Diversidade de macroalgas marinhas bentônicas dos recifes de Maracajaú, área de preservação ambiental dos recifes de corais, Rio Grande do Norte, Brasil

Despite the importance of coral reefs to humanity, these environments have been threatened throughout the world. Several factors contribute to the degradation of these ecosystems. The Maracajaú Reef Complex, in Rio Grande do Norte state is part of the Coral Reefs Environment Preservation Area in northeastern Brazil. This area has been receiving an increasing influx of tourism and the integrity of the local reefs is a matter of concern. In this study, the reef macroalgae communities were studied and compared within two areas distinguished by the presence or absence of tourism activities. Two sample sites were chosen: the first one, where diving activities are intense; and the other, where these practices do not occur. Samples were collected at both sites within a quadrate of 625 cm2 of area randomly thrown 5 times along a 10 meters transect line. Richness, Shannon-Hill diversity and Simpson dominance indices were determined based on biomass data. Similarity between sites was analyzed with Bray-Curtis similarity and distance index. Fifty-eight macroalgae species were observed, including 7 Chlorophyta, 13 Phaeophyta and 38 Rhodophyta. In the non-disturbed site, 49 species were found, while at the disturbed site, there were 42 species. Dictyotaceae and Corallinaceae were the most representative families at the non-disturbed site, and Rhodomelaceae and Dictyotaceae at the disturbed site. The non-disturbed site presented a higher biomass and the greatest richness and diversity indices. In the disturbed site the dominance index was greater and Caulerpa racemosa was the dominant species. The dendogram based on similarity index showed two major clusters, and an isolated element at the center that corresponds to a sample from the disturbed site. In the first cluster, samples from the non-impacted site were predominant and fleshy brown algae were more conspicuous. The second cluster was composed primarily of samples from the impacted site, where C. racemosa and red filamentous and erect calcareous algae associations (turf forming) were observed covering large extensions. These associations are represented by groups of algae adapted to environments where disturbances are frequent. They can grow rapidly on substrate where benthic community was removed and do not allow the establishment of other species. The results of the present study show that tourism activity is an impacting factor that has been causing shifts in macroalgae communities in the Maracajaú Reef Complex

Acknowledging long-term ecological change: the problem of shifting baselines

Shifting baselines describes the phenomenon where long-term changes to an environment go unrecognized because what is perceived as natural shifts with succeeding generations of scientists and other observers. This is a particular problem for the oceans because we are rarely able to directly observe the consequences of human activities. In the absence of data to track these consequences, a common assumption has been that the communities we observe today using SCUBA or other technology, are similar to the communities that existed 10, 100, or even 1000 years ago. Research is increasingly demonstrating this is not the case. Instead, marine ecosystems may have been vastly different in the past, and we have succumbed to the shifting baselines syndrome. This has significant implications for scientific study, management, and for human communities more broadly. We discuss these implications, and how we might address the shifting baseline syndrome in the oceans to confront its repercussions. In a world where environmental degradation is accelerating, doing so is critical to avoid further ratcheting down of our expectations of ecosystem health and productivity, and to ensure that we have the information necessary to implement appropriate recovery and management goals.

Toward adaptive management of coastal MPAs: The influence of different conservation targets and costs on the design of no-take areas

There is still much discussion on the most appropriate location, size and shape of marine protected areas (MPAs). These three factors were analyzed for a small coastal MPA, the Luiz Saldanha Marine Park (LSMP), for which a very limited amount of local ecological information was available when implemented in 1998. Marxan was used to provide a number of near-optimal solutions considering different levels of protection for the various conservation features and different costs. These solutions were compared with the existing no-take area of the LSMP. Information on 11 habitat types and distribution models for 3 of the most important species for the local artisanal fisheries was considered. The human activities with the highest economic and ecological impact in the study area (commercial and recreational fishing and scuba diving) were used as costs. The results show that the existing no-take area is actually located in the best area. However, the no-take area offers limited protection to vagile fish and covers a very small proportion of some of the available habitats. An increase in the conservation targets led to an increase in the number of no-take areas. The comparative framework used in this study can be applied elsewhere, providing relevant information to local stakeholders and managers in order to proceed with adaptive management. (C) 2015 Elsevier B.V. All rights reserved.

First record of Calcinus tubularis on the southern coast of Portugal (Crustacea: Decapoda: Anomura: Diogenidae)

Twenty-five specimens of the hermit crab Calcinus tubularis were observed during SCUBA dives for fauna and flora assessment in the shallow rocky reefs of the southern coast of Portugal between 2003 and 2008. Of the specimens observed, only one specimen used a tube gallery, while the others occupied unidentified gastropod shells with strong bio-cover. Calcinus tubularis is here recorded from the mainland Portuguese coast for the first time. This is the first record of the species in European coastal waters outside the Mediterranean Sea (excluding the Atlantic Islands) and extends the known geographical distribution of the species further north in the north-eastern Atlantic.

UMA LEITURA DA PAISAGEM SOCIOAMBIENTAL DA AGRICULTURA FAMILIAR NO RURAL DA REGIÃO METROPOLITANA DE CURITIBA, BRASIL

Objeto de reflexão: A dimensão da dinâmica natural, seus limites e potencialidades, e sua interação com a reprodução dos sistemas agrícolas da agricultura familiar.Situação empírica: A proposta desta pesquisa foi de investigar, por meio da análise integrada da paisagem, a dimensão da dinâmica natural, seus limites e suas potencialidades, na reprodução dos sistemas agrícolas da agricultura familiar em três comunidades rurais da região metropolitana de Curitiba (RMC-PR), a despeito das demais lógicas de desenvolvimento. Este estudo foi desenvolvido em três comunidades rurais de agricultores familiares: Mergulhão, em São José dos Pinhais, Santo Amaro, em Mandirituba, e Postinho, em Tijucas do Sul; todos municípios da região metropolitana de Curitiba (RMC - PR), no período de 2002-2006. O trabalho de campo aconteceu de outubro de 2003 a outubro de 2004 nas três comunidades selecionadas, para o levantamento de dados empíricos e averiguação dos dados secundários utilizados. Para analisar a complexidade dessas interações e lógicas na pesquisa interdisciplinar, elegeu-se uma abordagem teórico-metodológica que contemplou a integração das variáveis “naturais” e “sociais. Os resultados foram espacializados em cartas e no quadro analítico das práticas agrícolas avaliando-se o “grau de coerência” dos sistemas agrícolas, a “matrização” da base natural, as relações com o potencial ecológico e as formas de gestão dos solos para cada comunidade (Sautter e Pélissier, 1960). Concluiu-se que a dinâmica natural, suas fragilidades - potencial e emergente, é, ainda assim, expressiva na reprodução dos sistemas agrícolas familiares, para além das dimensões sócio-culturais e econômicas, certamente presentes na paisagem.