Exhaust Flue Gas Concentration of Engines Running on Ethanol, Gasoline and Bio-oil - a Theoretical Estimate

The creation of new technologies over the last 100 years has improved the quality of human life, but the necessary chemical and industrial transformations have caused significant changes in the environment. The production of new inputs depends on the chemical processes employed and, as a consequence, must be in line with water and air treatments that are undoubtedly undermined by world technological development. Thus, the principles of physics and chemistry apply to the prediction and understanding of the release of gaseous pollutants into the environment, which come from the burning of fuels in automobiles. It also discusses the influence of aspects related to the air content fed to the engine, as well as the effect of temperature and pressure on the concentration of these pollutants

Estimativa de densidade de álcoois biocombustíveis pelo segundo coeficiente da equação virial

Se estimaron los volúmenes molares o las densidades de seis alcoholes puros pertenecientes a la industria de biocombustibles para diferentes valores de temperatura dentro del rango de 280 K a 333 K utilizando un modelo desarrollado a partir de la ecuación de equilibrio de vapor líquido o la ecuación de Clausius-Clapeyron. El segundo coeficiente virial (B) se calculó a partir de los datos predictivos aplicados al modelo. Como es ampliamente conocido, las variaciones en el valor B se reflejarían en los volúmenes molares de los compuestos con resultados similares. En este trabajo, se observó que las desviaciones fueron positivas para todas las especies estudiadas y aumentaron entre los alcoholes de cadena larga de carbono. Cuando estuvo disponible, se realizó una comparación entre el volumen molar experimentaly el volumen molar predicho.Os volumes molares ou densidades de seis álcoois puros pertencentes à indústria de biocombustíveis foram estimados para diferentes valores de temperaturas dentro da faixa entre 280 K e 333 K, utilizando um modelo desenvolvido a partir da equação de equilíbrio líquido-vapor ou Equação de Clausius- Clapeyron. O segundo coeficiente virial (B) foi calculado a partir de dados preditivos aplicados ao modelo. Como  amplamente conhecido, variações no valor de B refletiriam nos volumes molares dos compostos com resultado semelhante. Neste trabalho, observou-se que os desvios foram positivos para todas as espécies estudadas e aumentaram entre os álcoois de longa cadeia de carbono. Quando disponível, foi feita uma comparação entre o volume molar experimental e o predito.The molar volumes or densities of six pure alcohols belonged to biofuel industry have been estimated for different values of temperatures within the range between 280 K and 333 K, using a model developed from vapour-liquid equilibrium equation or Clausius-Clapeyron Equation. The second virial coefficient (B) has been calculated from predictive data applied to the model. As widely known, variations in the B value would reflect in the compounds molar volumes with similar result. In this work, it was observed that the deviations were positive for all studied species, and they increased among long carbon chain alcohols. When avalaible, a comparison between experimental and predicted molar volume was done

Comparison of temporal and spatial variation of periphytic algal community in two urban lakes in Umuarama-PR (Brazil)

Water resources are very important for all living organisms, and as being of vital importance need to be preserved. Thus, many water bodies are monitored as an essential strategy for identification of possible alterations over space and time. The analyses were performed in two different hydrological conditions, and water sample and rocks were collected in two different points at each lake. The results showed higher values of Ammoniacal Nitrogen in Aratimbó Lake, mainly during dry period (Ammoniacal Nitrogen = 4.2 mgL-1) at P1. However, P2 at Tucuruvi Lake presented higher concentration of Orthophosphate (2.24 mgL-1). Total Periphyton density also demonstrated variation among the different hydrological scenarios and lakes. The Highest density was of 385.30 10³ ind.cm-2at Aratimbó Lake and 180.43 10³ ind.cm-2at Tucuruvi Lake in rainy condition. Comparing the predominance of species, In Aratimbó Lake, Chlorophyceae class was predominant at P1, while Cyanophyceae class was predominant at P2. In dry period, Bacillarophyceae class was seen as the predominant class for both of lakes and for all sampling points. Differently from Aratimbó Lake, in Tucuruvi Lake Bacillarophyceae class was predominant in both of hydrological scenarios

Characteristics of health professionals affected by Covid-19 : an integrative literature review

O objetivo do estudo consistiu em identificar as características de profissionais de saúde acometidos por Covid-19. Trata-se de uma revisão integrativa da literatura guiada por seis etapas e que pesquisou cinco fontes de dados. Após o estabelecimento do fluxo de seleção do material levantado (N=5.522), determinou-se a amostra de artigos analisada (n=30). Desta, foram sintetizadas informações a respeito das características dos trabalhadores e relativas ao acometimento por Covid-19. Entre os estudos selecionados, foram compilados dados de 10.760 trabalhadores de saúde, predominantemente da equipe de enfermagem (27,3%) e médicos (13,2%). A maior parte (n=20; 66,6%) dos estudos atestou que os profissionais de saúde foram contaminados no ambiente de trabalho, principalmente hospitalar. A testagem por RT-PCR foi o principal método diagnóstico. Alguns estudos (n=16; 53,3%) relataram comorbidades prévias entre os trabalhadores. Os principais sintomas da Covid-19 nos profissionais de saúde acometidos foram: febre, tosse, fadiga e mialgia. Constataram-se características que remontam em perfil concentrado de enfermeiras e médicos contaminados no hospital. Essa realidade foi focalizada entre pesquisas transversais chinesas, italianas e estadunidenses.The objective of the study was to identify the characteristics of health professionals affected by Covid-19. It is an integrative literature review guided by six steps and which researched five data sources. After establishing the selected material flow (N=5,522), the analyzed sample of articles was determined (n=30). From this, information was summarized regarding the characteristics of the workers and related to getting sick by Covid-19. Among the selected studies, data from 10,760 health workers were compiled, predominantly nursing team (27.3%) and physicians (13.2%). Most (n=20; 66.6%) of the studies attested that health professionals were contaminated in the work environment, mainly in hospitals. RT-PCR testing was the main diagnostic method. Some studies (n=16; 53.3%) reported previous comorbidities among workers. The main symptoms of Covid-19 in affected health professionals were: fever, coughing, fatigue, and myalgia. Characteristics that go back to a concentrated profile of nurses and doctors contaminated in the hospital were found. This reality was focused on Chinese, Italian and North American cross-sectional research

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

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe