Pigmentos perolizados à partir do recobrimento de muscovita com óxidos de terras-raras

DepositadaA presente Patente de Invenção se refere à síntese de pigmentos perolizados com base em recobrimento de mica do tipo muscovita com óxidos de terras-raras. A muscovita utilizada é brasileira, natural e oriunda da província pegmatítica da região Borborema-Seridó (divisa entre RN e PB). Para síntese dos pigmentos utilizou-se o método de precipitação

Composites Based on Post-Industrial Wood Plastic Waste and Ultrasonic Treated Muscovite

In this work muscovite was ultrasonically treated to obtain composites with post-industrial wood plastic residues. The muscovite was ultrasonicated for 30 or 60 min and mixed with the polymeric matrix at a constant level of 15% (weight percentage). The composites were prepared in a single-screw extruder and formed into flat films for characterization. SEM images of the ultrasonicated muscovite revealed the occurrence of delamination, while the particle size distribution results suggested a decrease in size with longer sonication time. FTIR spectra also indicated the occurrence of delamination of the material. The composites exhibited a slight increase in density and a large increase in impact resistance of the samples with ultrasonicated muscovite. The XRD of the composites suggested the occurrence of alignment of the mineral in the matrix. The results indicate that ultrasonication is an effective method to improve the interaction and dispersion of muscovite with wood plastic waste to obtain composites

Guidance for the integrated use of hydrological, geochemical, and isotopic tools in mining operations

This paper summarizes international state-of-the-art applications and opportunities for employing and deploying hydrological, geochemical, and isotopic tools in an integrated manner for investigations of mining operations. It is intended to aid formulation of more integrated approaches for evaluating the overall sustainability of mining projects. The focus is particularly on mine waters, including: environmental water sources, mine water dynamics, and as a source and vector for pollution in the wider environment. The guidance is generic to mining projects and not just reflective of a particular extraction (e.g. coal, metalliferous, uranium) industry. A mine life cycle perspective has been adopted to highlight the potential for more integrated investigations at each stage of a mining operation. Three types of mines have been considered: new (i.e. those in the planning stage), active (i.e. working mines), and historical mines (i.e. inactive and abandoned mines). The practical usage of geochemical analyses and isotopic studies described here emphasise characterisation, dynamics, and process understanding for water quality considerations in tandem with water resource and environmental impact implications. Both environmental (i.e. ambient) and applied (i.e. injected) tracers are considered. This guide is written for scientists (including isotope specialists) who have limited or no mine water experience, environmental managers, planners, consultants, and regulators with key interests in planned, active, and legacy mining projects.The authors thank the IAEA for inviting us to collate an initial report on guidelines from 2018-06-25–28 in Vienna. We thank Chris Gammons for allowing us to use one of his fgures. We especially thank Umaya Doss Saravana Kumar, Lucia Ortega, and Araguás-Araguás from IAEA for assistance, and Andrea Nick for input during the meeting. Special thanks to our reviewers who substantially helped improve the structure and content of this guidance document

revista de Ciências da Arte

Organizando-se agora no formato de número duplo, de modo a comportar dois números por ano, a revista digital Convocarte – Revista de Ciências da Arte mantém o mesmo propósito de promover o debate e edição de questões artísticas no espaço universitário, mantendo as coordenadas dominantes: convocar um número de especialistas em torno de um tema do mundo das artes, integrar trabalhos relevantes desenvolvidos nas fases curriculares e de projecto em mestrados e doutoramentos, sobretudo da FBAUL, e publicar trabalhos desenvolvidos em linhas de investigação do CIEBA. Assim, embora de funcionamento afecto à área científica de Ciências da Arte e do Património a Convocarte está aberta a outras especialidades interessadas em contribuir para a reflexão sobre as artes em geral, incorporando ensaios de predomínio teórico enraizado nos mais predominantes modos de discurso sobre arte, tais como História da arte, Crítica de Arte, Estética, Teorias da Arte ou Curadoria. (...) O nº2 organizou-se em torno de uma homenagem a uma figura importante das teorias da arte em Portugal, estratégia que Convocarte procurará manter nos próximos números. A intenção será deixar estudos sistematizados, entre o depoimento ou o ensaio, a memória e a reflexão, que estudem figuras marcantes da cultura portuguesa. (...) Neste número essa pasta foi dedicada a Rui Mário Gonçalves. Os textos são o resultado de uma sessão especial alargada a 2 de Maio no âmbito dos 2ºs Encontros com Críticos de Arte, com organização e coordenação de Fernando Rosa Dias, Cristina Tavares e Viviane Soares Silva, e decorridos ao longo das segundas do mês de Maio de 2016 na FBAUL (http://convocarte.belasartes.ulisboa.pt/index.php/2016/04/29/2o-encontros-com-criticos-de-arte/#more-325). A partir destes trabalhos reuniu-se um conjunto de estudos em torno de Rui Mário Gonçalves, com depoimentos e estudos sobre as mais diferentes facetas desta importante figura da cultura portuguesa: crítico de arte, historiador de arte, curador artístico, pedagogo e professor, político e activista, etc. A Convocarte orgulha-se de publicar os textos dessas comunicações, acrescentado de outros estudos, agradecendo a todos os colaboradores deste evento, que consideramos uma pasta que adianta contributos dando continuidade a estudos no catálogo de homenagem e no âmbito de apresentação da colecção do crítico de arte na SNBA, realizada pouco antes na SNBA.info:eu-repo/semantics/publishedVersio

Estudos Artísticos

Há um compromisso entre o artista e a sociedade. Não é possível retirar a arte do seu contexto social. Neste projecto, em que se desafiam os criadores a pesquisar a obra de outros criadores, reúnem-se aqueles artigos que melhor demonstram a responsabilidade e a solidariedade entre os criadores e os seus pares sociais. São obras, artistas, projetos, plataformas de intervenção, projetos que enfatizam as relações sociais como suporte. Sob esta temática geral foram reunidos 25 artigos para este número 6 da Revista Croma, em linhas de exploração variadas e mantendo a elevada internacionalização da revista: mais de noventa por cento das publicações são exógenas à Faculdade de Belas-Artes da Universidade de Lisboa ou do CIEBA, a sua unidade de investigação. Este é um indicador procurado e atingido de modo consistente em todos os exemplares publicados até hoje, e que se espera poder afirmar com continuidade. As diferentes perspetivas apresentadas nos variados artigos expõe a obra de autores que exploram dimensões relacionais ou perante as quais o espectador é convocado a deslocar o seu posicionamento, a desassossegar-se. A implicação surge como resultado da articulação expressiva dos recursos mais variados, em constante mistura, exibindo o modo como as dimensões materiais e ideais são fundadoras das diversas propostas. Nesta revista não há indiferença, há diferenças.info:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Rheology applied to the environmental management of mineral tailings: focus on safer disposal and water reuse

Abstract Mining activities worldwide are subject to serious geotechnical accidents involving tailings dams. Therefore, many studies have focused on tailings dewatering before their deposition. This article studies the rheological properties of flocculated and thickened nickel tailings in order to determine the effect of the initial solid concentration and type of rheology modifying agents (two anionic polymeric flocculants) on their stability for disposal in dams. The sediment was submitted to rheological tests, with the vane technique, and slump tests, to obtain information about static and dynamic yield stress and slump height, respectively. The results showed a strong influence of the initial solid concentration and the polymeric flocculant on the particle aggregation. Both particle cohesion and yield stress of the sediment increased, reaching static yield stress of around 1,400 Pa. Both flocculants were efficient in thickening by batch sedimentation, allowing water recycling in the range of 70-90% with turbidity less than 100 NTU and the production of sediment with static yield stress much higher than specified for mineral paste