Argamassas com desempenho térmico melhorado

No contexto da investigação de novas tecnologias no domínio da conservação de energia surgem os “Phase Change Materials” (PCM) cuja principal característica é a mudança de fase (fase líquida para fase sólida e vice-versa) próximo à temperatura ambiente. O objecto desta comunicação é a divulgação de uma nova tecnologia, no domínio da técnica de aplicação de argamassas, que poderá ser utilizada na construção dos espaços interiores das construções. Os resultados dos ensaios efectuados mostraram que a incorporação de 25 % de PCM em peso, mantém as propriedades mecânicas das argamassas em níveis aceitáveis e é benéfica do ponto de vista térmico

description of the methodological approach

publishersversionpublishe

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

Anatomia foliar de pedra-hume-caá (Myrcia sphaerocarpa, Myrcia guianensis, Eugenia punicifolia - Myrtaceae)

As folhas de Myrcia multiflora (Lam.) DC, Myrcia guianensis (Aubl.) Urb. e Eugenia punicifolia (H. B. K.) DC. são anatômica c morfologicamentc descritas. As espécies revelaram diversos elementos histológicos universais para a família, bem como peculiares das mesmas e importantes para orientar a diagnose desses vegetais e para o reconhecimento de fraudes, que ocorrem através de substituições intencionais ou não. Entre os elementos histológicos característicos, destacam-se: ornamentações de cutícula foliar, tipos de estômatos, tipos de contornos celulares das células epidérmicas em vista facial, tipo e abundância relativa de inclusões celulares inorgânicas

Wild pejibaye (Bactris dahlgreniana Glassman): ancestor of the pejibaye (B. gasipaes H.B.K.)?

A pupunha brava (Bactris dahlgreniana) pode ser considerada uma possível projenitora da pupunha (B. gasipaes). Amostras de duas populações, uma de Rondônia e outra do Acre, foram caracterizadas com os descritores de pupunha e três amostras de frutos foram analisadas. A variação fenotípica é discutida, bem como a composição centesimal e da qualidade do óleo. Três análises discriminantes comparando a B. dahlgreniana e a pupunha demonstram que as espécies são vegetativamente similares e reprodutivamente distintas, com tendências que sugerem que a primeira é progenitora da segunda