Caracterização quantitativa do volume de cavidades em um dispositivo de cavitação hidrodinâmica usando dinâmica de fluidos computacional

Hydrodynamic cavitation has been extensively studied for its potential to remove emerging pollutants. Despite the advance of the experimental studies involving this phenomenon, computational studies that evaluate the influence of the geometry of the cavitation devices on the flow parameters are still necessary. The purpose of this article was to evaluate the influence of the change in the geometry of a Venturi device on the volume of cavities formed in its divergent section using Computational Fluid Dynamics (CFD). The geometric parameters modified in the Venturi were: the diffuser angle and the relation between the height and the width of the throat (h/w). The volume of cavities is an important parameter because it influences the cavitation intensity. A cavitational bench system was constructed in order to obtain input data for simulation. The results showed that the increase in the diffuser angle from 6.5° to 18.5° gradually reduced the volume of cavities from 93 mm3 to 10 mm3. Between the relations h/w = 0.05 and h/w = 0.45 was observed the formation of cavities between 106 mm3 and 77 mm3, however between h/w = 0.45 and h/w = 1.0 there was the formation of 213 mm3. Therefore, Venturi’s with diffuser angle less than 6.5º and relation h/w greater than 0.45 produce greater volume of cavities. The greater volume of cavities will not necessarily produce greater cavitational intensity, since cavitation clouds can be formed and reduce the implosion intensity of the cavitation bubbles.A cavitação hidrodinâmica tem sido amplamente estudada por seu potencial em remover poluentes emergentes. Apesar do avanço dos estudos experimentais envolvendo este fenômeno, ainda são necessários estudos computacionais que avaliem a influência da geometria dos dispositivos de cavitação nos parâmetros de escoamento. O objetivo deste artigo foi avaliar, por meio da Dinâmica de Fluidos Computacional (CFD), a influência da mudança da geometria de um dispositivo de Venturi sobre o volume de cavidades formadas em sua seção divergente. Os parâmetros geométricos modificados no Venturi foram: o ângulo divergente e a relação entre a altura e a largura da garganta (h/w). O volume das cavidades é um parâmetro importante porque influencia a intensidade da cavitação. Um sistema de bancada cavitacional foi construído a fim de obter dados de entrada para simulação. Os resultados mostraram que o aumento do ângulo divergente de 6,5° para 18,5° reduziu gradativamente o volume das cavidades de 93 mm3 para 10 mm3. Entre as relações h/w = 0,05 e h/w = 0,45 observou-se a formação de cavidades entre 106 mm3 e 77 mm3, porém entre h/w = 0,45 e h/w = 1,0 ocorreu a formação de 213 mm3. Portanto, Venturi's com ângulo divergente menor que 6,5º e relação h/w maior que 0,45 produzem maior volume de cavidades. O maior volume de cavidades não necessariamente produzirá maior intensidade cavitacional, uma vez que nuvens de cavitação podem se formar e reduzir a intensidade de implosão das bolhas de cavitação

RESISTANCE TO PENETRATION IN SOIL CULTIVATED WITH SUGARCANE IN DIFFERENT MANAGEMENT SYSTEMS

Sugarcane has its productivity influenced by the availability of water and nutrients. Being the understanding of the influence of the irrigation system over time on soil compaction is important for the improvement of the management adopted in the production of this crop. The objective of this paper was to evaluate the influence of the three irrigation systems: pivot and reel, reainfed, and reel, on the resistance to root penetration of the sugarcane crop, in a period of six years. The work was carried out under field conditions, in the experimental design of a 3 x 6 factorial scheme in 24 replicates, in which the first factor consists of three irrigation systems: conventional (clean water) reel; pivot and reel (fertigation); and rainfed cultivation. And the second factor is related to different periods under irrigation: Cane-plant area, second cut area, third cut area, fourth cut area, fifth cut area, reaching the sixth cut. A penetrometer was used to determine the resistance to root penetration. At the end of this experiment, the results showed that the use of the pivot and reel irrigation system is the one that least affects the resistance to soil penetration, being the most suitable for us

Boosting big data streaming applications in clouds with burstFlow

The rapid growth of stream applications in financial markets, health care, education, social media, and sensor networks represents a remarkable milestone for data processing and analytic in recent years, leading to new challenges to handle Big Data in real-time. Traditionally, a single cloud infrastructure often holds the deployment of Stream Processing applications because it has extensive and adaptative virtual computing resources. Hence, data sources send data from distant and different locations of the cloud infrastructure, increasing the application latency. The cloud infrastructure may be geographically distributed and it requires to run a set of frameworks to handle communication. These frameworks often comprise a Message Queue System and a Stream Processing Framework. The frameworks explore Multi-Cloud deploying each service in a different cloud and communication via high latency network links. This creates challenges to meet real-time application requirements because the data streams have different and unpredictable latencies forcing cloud providers' communication systems to adjust to the environment changes continually. Previous works explore static micro-batch demonstrating its potential to overcome communication issues. This paper introduces BurstFlow, a tool for enhancing communication across data sources located at the edges of the Internet and Big Data Stream Processing applications located in cloud infrastructures. BurstFlow introduces a strategy for adjusting the micro-batch sizes dynamically according to the time required for communication and computation. BurstFlow also presents an adaptive data partition policy for distributing incoming streams across available machines by considering memory and CPU capacities. The experiments use a real-world multi-cloud deployment showing that BurstFlow can reduce the execution time up to 77% when compared to the state-of-the-art solutions, improving CPU efficiency by up to 49%

Serum soluble-Fas is a predictor of red blood cell transfusion in critically ill patients

OBJECTIVE: To investigate the relation between the need for red blood cell transfusion and serum levels of soluble-Fas, erythropoietin and inflammatory cytokines in critically ill patients with and without acute kidney injury. METHODS: We studied critically ill patients with acute kidney injury (n=30) and without acute kidney injury (n=13), end-stage renal disease patients on hemodialysis (n=25) and healthy subjects (n=21). Serum levels of soluble-Fas, erythropoietin, interleukin 6, interleukin 10, iron status, hemoglobin and hematocrit concentration were analyzed in all groups. The association between these variables in critically ill patients was investigated. RESULTS: Critically ill patients (acute kidney injury and non-acute kidney injury patients) had higher serum levels of erythropoietin than the other groups. Hemoglobin concentration was lower in the acute kidney injury patients than in other groups. Serum soluble-Fas levels were higher in acute kidney injury and end-stage renal disease patients. Critically ill patients requiring red blood cell transfusions had higher serum levels of soluble-Fas (5,906±2,047 and 1,920±1,060; p<0.001), interleukin 6 (518±537 and 255+502; p=0.02) and interleukin 10 (35.8±30.7 and 18.5±10.9; p=0.02), better iron status and higher mortality rates in the first 28 days in intensive care unit. Serum soluble-Fas levels were independently associated with the number of red blood cell units transfused (p=0.02). Serum soluble-Fas behaved as an independent predictor of the need for red blood cell transfusion in critically ill patients (p=0.01). CONCLUSIONS: Serum soluble-Fas level is an independent predictor of the need for red blood cell transfusion in critically ill patients with or without acute kidney injury. Further studies are warranted to reconfirm this finding.OBJETIVO: Investigar a relação entre a transfusão de hemácias e os níveis séricos de Fas solúvel, eritropoietina e citocinas inflamatórias em pacientes gravemente enfermos, com e sem insuficiência renal aguda. MÉTODOS: Os seguintes grupos foram estudados: pacientes gravemente enfermos com insuficiência renal aguda (n=30) e sem insuficiência renal aguda (n=13), pacientes portadores de doença renal crônica terminal em hemodiálise (n=25) e indivíduos saudáveis (n=21). Os níveis séricos de Fas solúvel, eritropoietina, interleucina 6, interleucina 10 e ferro, além da concentração de hemoglobina e de hematócrito, foram analisados em todos os grupos. A associação entre tais variáveis foram estudadas nos pacientes gravemente enfermos. RESULTADOS: Os níveis séricos de eritropoietina mostraram-se mais elevados nos pacientes gravemente enfermos do que nos dos demais grupos. Concentrações mais baixas de hemoglobina foram documentadas nos pacientes com insuficiência renal aguda em relação aos demais. Níveis séricos mais elevados de Fas solúvel foram observados nos pacientes com insuficiência renal aguda e doença renal crônica terminal. Pacientes gravemente enfermos transfundidos apresentaram níveis séricos mais elevados de Fas solúvel (5.906±2.047 e 1.920±1.060; p<0,001), interleucina 6 (518±537 e 255±502; p=0,02), interleucina 10 (35,8±30,7 e 18,5±10,9; p=0,02) e ferro, além de maior mortalidade em 28 dias. Os níveis séricos de Fas solúvel mostraram-se independentemente associados ao número de transfusões (p=0,02). O nível sérico de Fas solúvel foi um preditor independente da necessidade de transfusão de hemácias em pacientes gravemente enfermos (p=0,01). CONCLUSÃO: O nível sérico de Fas solúvel é um preditor independente da necessidade de transfusão de hemácias em pacientes gravemente enfermos, com ou sem insuficiência renal aguda. Mais estudos clínicos e laboratoriais são necessários para confirmar tal resultado.Universidade Federal de São Paulo (UNIFESP)Hospital Israelita Albert EinsteinUNIFESPSciEL

The Genome of the Zoonotic Malaria Parasite Plasmodium simium Reveals Adaptions to Host-switching

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The genome of the zoonotic malaria parasite Plasmodium simium reveals adaptations to host switching

BACKGROUND: Plasmodium simium, a malaria parasite of non-human primates (NHP), was recently shown to cause zoonotic infections in humans in Brazil. We sequenced the P. simium genome to investigate its evolutionary history and to identify any genetic adaptions that may underlie the ability of this parasite to switch between host species. RESULTS: Phylogenetic analyses based on whole genome sequences of P. simium from humans and NHPs reveals that P. simium is monophyletic within the broader diversity of South American Plasmodium vivax, suggesting P. simium first infected NHPs as a result of a host switch of P. vivax from humans. The P. simium isolates show the closest relationship to Mexican P. vivax isolates. Analysis of erythrocyte invasion genes reveals differences between P. vivax and P. simium, including large deletions in the Duffy-binding protein 1 (DBP1) and reticulocyte-binding protein 2a genes of P. simium. Analysis of P. simium isolated from NHPs and humans revealed a deletion of 38 amino acids in DBP1 present in all human-derived isolates, whereas NHP isolates were multi-allelic. CONCLUSIONS: Analysis of the P. simium genome confirmed a close phylogenetic relationship between P. simium and P. vivax, and suggests a very recent American origin for P. simium. The presence of the DBP1 deletion in all human-derived isolates tested suggests that this deletion, in combination with other genetic changes in P. simium, may facilitate the invasion of human red blood cells and may explain, at least in part, the basis of the recent zoonotic infections

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off