Metodologia de avaliação do processo de retrolavagem em filtros de areia pressurizados

The objective of this study was to apply a methodology based on sampling sand from contaminated filter beds, to evaluate the performance of the backwash process in pressurized sand filters used in irrigation. Backwash trials were conducted in an experimental module with three new sand filters of the same commercial model. The evaluations were conducted after filtration processes performed using four filtration rates and three separate sand particle sizes (fine - 0.55 mm; medium - 0.77 mm, and coarse sand - 1.04 mm diameter), repeated in three subsequent cycles. After reaching a fixed expansion of 25% of the filter bed height, the backwash processes were performed for 15 min. Backwash cleaning efficiency was evaluated in all trials based on the mass of removed solids for different filter bed layers and throughout the entire filter bed. The backwash assessment methodology is effective and has potential to be a practical tool for farmers in the evaluation of the performance of pressurized sand filters used in irrigation.Propôs-se, neste trabalho, aplicar uma metodologia baseada em amostragens de areia de leitos filtrantes contaminados para avaliar o desempenho do processo de retrolavagem em filtros de areia pressurizados utilizados na irrigação. Os ensaios de retrolavagem foram conduzidos em um módulo experimental constituído de três filtros novos de areia e de um mesmo modelo comercial. As avaliações foram conduzidas após processos de filtração realizados com o emprego de quatro taxas de filtração em três granulometrias de areia, separadamente (areia fina, 0,55 mm; média, 0,77 mm e grossa, 1,04 mm de diâmetro) repetidos em três ciclos de filtração subsequentes; após atingir uma expansão fixa de 25% da altura leito filtrante, as retrolavagens foram processadas por 15 min; a eficiência de limpeza da retrolavagem foi avaliada em todos os ensaios a partir da massa de sólidos removidos para as diferentes camadas do leito filtrante e para a camada, por inteiro. A metodologia de avaliação do processo de retrolavagem é eficaz e possui potencial para ser uma ferramenta prática para o agricultor na avaliação do desempenho de filtros de areia pressurizados utilizados na irrigação.The objective of this study was to apply a methodology based on sampling sand from contaminated filter beds, to evaluate the performance of the backwash process in pressurized sand filters used in irrigation. Backwash trials were conducted in an experimen207600605FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOsem informaçãoPropôs-se, neste trabalho, aplicar uma metodologia baseada em amostragens de areia de leitos filtrantes contaminados para avaliar o desempenho do processo de retrolavagem em filtros de areia pressurizados utilizados na irrigação. Os ensaios de retrolavag

Comparative assessment of mortality risk factors between admission and follow-up models among patients hospitalized with COVID-19

Objectives: This study aimed to compare differences in mortality risk factors between admission andfollow-up incorporated models.Methods: A retrospective cohort study of 524 patients with confirmed COVID-19 infection admitted to atertiary medical center in São Paulo, Brazil from 13 March to 30 April 2020. Data were collected onadmission, and the third, eighth and fourteenth days of hospitalization. The hazard ratio (HR) wascalculated and 28-day in-hospital mortality risk factors were compared between admission and follow-up models using a time-dependent Cox regression model.Results: Of 524 patients, 50.4% needed mechanical ventilation. The 28-day mortality rate was 32.8%.Compared with follow-up, admission models under-estimated the mortality HR for peripheral oxygensaturation 100 bpm (1.19 versus 2.04), respiratory rate >24/min (1.01versus 1.82) and mechanical ventilation (1.92 versus 12.93). Low oxygen saturation, higher oxygensupport and more biomarkers–including lactate dehydrogenase, C-reactive protein, neutrophil-lymphocyte ratio, and urea remained associated with mortality after adjustment for clinical factorsat follow-up compared with only urea and oxygen support at admission.Conclusions: The inclusion of follow-up measurements changed mortality hazards of clinical signs andbiomarkers. Low oxygen saturation, higher oxygen support, lactate dehydrogenase, C-reactive protein,neutrophil-lymphocyte ratio, and urea could help with prognosis of patients during follow-up

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

Assessment methodology of backwash in pressurized sand filters

A B S T R A C T The objective of this study was to apply a methodology based on sampling sand from contaminated filter beds, to evaluate the performance of the backwash process in pressurized sand filters used in irrigation. Backwash trials were conducted in an experimental module with three new sand filters of the same commercial model. The evaluations were conducted after filtration processes performed using four filtration rates and three separate sand particle sizes (fine -0.55 mm; medium -0.77 mm, and coarse sand -1.04 mm diameter), repeated in three subsequent cycles. After reaching a fixed expansion of 25% of the filter bed height, the backwash processes were performed for 15 min. Backwash cleaning efficiency was evaluated in all trials based on the mass of removed solids for different filter bed layers and throughout the entire filter bed. The backwash assessment methodology is effective and has potential to be a practical tool for farmers in the evaluation of the performance of pressurized sand filters used in irrigation. Metodologia de avaliação do processo de retrolavagem em filtros de areia pressurizados R E S U M O Propôs-se, neste trabalho, aplicar uma metodologia baseada em amostragens de areia de leitos filtrantes contaminados para avaliar o desempenho do processo de retrolavagem em filtros de areia pressurizados utilizados na irrigação. Os ensaios de retrolavagem foram conduzidos em um módulo experimental constituído de três filtros novos de areia e de um mesmo modelo comercial. As avaliações foram conduzidas após processos de filtração realizados com o emprego de quatro taxas de filtração em três granulometrias de areia, separadamente (areia fina, 0,55 mm; média, 0,77 mm e grossa, 1,04 mm de diâmetro) repetidos em três ciclos de filtração subsequentes; após atingir uma expansão fixa de 25% da altura leito filtrante, as retrolavagens foram processadas por 15 min; a eficiência de limpeza da retrolavagem foi avaliada em todos os ensaios a partir da massa de sólidos removidos para as diferentes camadas do leito filtrante e para a camada, por inteiro. A metodologia de avaliação do processo de retrolavagem é eficaz e possui potencial para ser uma ferramenta prática para o agricultor na avaliação do desempenho de filtros de areia pressurizados utilizados na irrigação

Assessment methodology of backwash in pressurized sand filters

ABSTRACT The objective of this study was to apply a methodology based on sampling sand from contaminated filter beds, to evaluate the performance of the backwash process in pressurized sand filters used in irrigation. Backwash trials were conducted in an experimental module with three new sand filters of the same commercial model. The evaluations were conducted after filtration processes performed using four filtration rates and three separate sand particle sizes (fine - 0.55 mm; medium - 0.77 mm, and coarse sand - 1.04 mm diameter), repeated in three subsequent cycles. After reaching a fixed expansion of 25% of the filter bed height, the backwash processes were performed for 15 min. Backwash cleaning efficiency was evaluated in all trials based on the mass of removed solids for different filter bed layers and throughout the entire filter bed. The backwash assessment methodology is effective and has potential to be a practical tool for farmers in the evaluation of the performance of pressurized sand filters used in irrigation