Estudo da substituição do nylon por compósito de polipropileno com fibra de vidro

Peças fabricadas com polímeros de alto desempenho têm sido substituídas por materiais similares, sendoproduzidas com uma composição de polipropileno (PP), que tem um custo mais baixo. Uma das composiçõesmais comumente utilizadas é a junção do polipropileno com fibras, resultando na formação de um novo material,com características diferentes às dos seus constituintes. Este tipo de junção é denominado compósito.O objetivo deste trabalho é avaliar o comportamento do compósito de polipropileno com fibra de vidro para asubstituição do material da carcaça de um elemento filtrante fabricado atualmente com um compósito denylon e fibra de vidro na proporção de 30% em peso. Foram injetados corpos de prova usando PP puro e comcargas de fibra de vidro nas proporções de 15%, 20% e 30%, a análise de comportamento, através de ensaiode tração, flexão, resistência ao impacto, dureza, índice de fluidez e determinação do índice de contraçãoindicou o compósito PP com 30% de fibra de vidro com melhor comportamento. Posteriormente realizou-se ainjeção da carcaça do elemento filtrante no compósito PP com 30% de fibra de vidro que passou por testespráticos.Palavras-chave: Polipropileno, nylon, fibra de vidro, elemento filtrante

Factors affecting the performance of Pantaneiro horses

This study aimed to assess the physical performance of Pantaneiro horses with and without equine infectious anemia (EIA) under functional conditions of cattle management. The horses were subjected to a performance test and split into two groups according to a completely randomized design: animals were chosen from populations testing positive and negative for EIA. Performance was measured as a function of a data envelopment analysis (DEA) model considering four outputs and one unitary input. The output measures were the distance achieved in the performance test, hematocrit as a weighted average over the test duration, respiratory rate as weighted average over the test duration, and the level of lactic acid at the test termination. Weights for the hematocrit and the respiratory rate output variables were determined by means of factor analysis. The performance score was a weighted average of the output variables with the weights defined by the averages of the optimum individual multipliers in the DEA analysis. Contextual variables of interest were age, horse weight, room temperature, and corporal temperature. Only groups and room temperature were statistically significant effects, as indicated by a bootstrap analysis. The performance of group positive for EIA is significantly lower than that of the group negative for EIA and room temperature has a negative effect.Instituto de Genética Veterinari

Factors affecting the performance of Pantaneiro horses

This study aimed to assess the physical performance of Pantaneiro horses with and without equine infectious anemia (EIA) under functional conditions of cattle management. The horses were subjected to a performance test and split into two groups according to a completely randomized design: animals were chosen from populations testing positive and negative for EIA. Performance was measured as a function of a data envelopment analysis (DEA) model considering four outputs and one unitary input. The output measures were the distance achieved in the performance test, hematocrit as a weighted average over the test duration, respiratory rate as weighted average over the test duration, and the level of lactic acid at the test termination. Weights for the hematocrit and the respiratory rate output variables were determined by means of factor analysis. The performance score was a weighted average of the output variables with the weights defined by the averages of the optimum individual multipliers in the DEA analysis. Contextual variables of interest were age, horse weight, room temperature, and corporal temperature. Only groups and room temperature were statistically significant effects, as indicated by a bootstrap analysis. The performance of group positive for EIA is significantly lower than that of the group negative for EIA and room temperature has a negative effect.Instituto de Genética Veterinari

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