Abordagem experimental e numérica aplicada na dissolução do calcário no processo de dessulfurização de gases de combustão

Wet FGD technologies account for around 87% of FGD systems worldwide (SOUD, 2000), particularly that which u ses limestone as the absorbent reagent. This technique is widely used in large thermal power stations. The limestone reactivity is one of the parameters that most influence the yield of the FGD process. To evaluate limestone reactivity experiments were conducted in one agitated batch reactor, with pH and temperature control and CO2 sparging. With the aim of improving the design and operation of desulfurization units, many studies have been carried out to investigate the rate of limestone dissolution. This proposed model considers the grain-sized distribution of particles, composition and pH of the liquid phase. This model was validated with experimental results, allowing predicting limestone dissolution kinetics in acid pH, with a maximum error of 18%.A tecnologia de dessulfurização úmida abrange aproximadamente 87% do mercado mundial (SOUD, 2000), especialmente a que utiliza como reagente absorvente, sendo particularmente empregada em grandes centrais termelétricas. A reatividade do calcário é um dos parâmetros que mais influem no rendimento do processo de dessulfurização de gases de combustão. Neste trabalho foram realizados experimentos em um reator de batelada agitado, com controle de pH e temperatura, com borbulhamento de CO2, para avaliação da reatividade do calcário, bem como a elaboração de um modelo para simular a dissolução das partículas de calcário. O modelo proposto leva em consideração a distribuição granulométrica das partículas, sua composição e o pH da matriz líquida onde se realiza a dissolução. Este modelo foi validado utilizando os resultados obtidos experimentalmente, permitindo predizer a cinética de dissolução do calcário em pH ácido, sendo o erro máximo entre os resultados experimentais e os numéricos de 18%

2 nd Brazilian Consensus on Chagas Disease, 2015

Abstract Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Abordagem experimental e numérica aplicada na dissolução do calcário no processo de dessulfurização de gases de combustão

A tecnologia de dessulfurização úmida abrange aproximadamente 87% do mercado mundial (SOUD, 2000), especialmente a que utiliza como reagente absorvente, sendo particularmente empregada em grandes centrais termelétricas. A reatividade do calcário é um dos parâmetros que mais influem no rendimento do processo de dessulfurização de gases de combustão. Neste trabalho foram realizados experimentos em um reator de batelada agitado, com controle de pH e temperatura, com borbulhamento de CO2, para avaliação da reatividade do calcário, bem como a elaboração de um modelo para simular a dissolução das partículas de calcário. O modelo proposto leva em consideração a distribuição granulométrica das partículas, sua composição e o pH da matriz líquida onde se realiza a dissolução. Este modelo foi validado utilizando os resultados obtidos experimentalmente, permitindo predizer a cinética de dissolução do calcário em pH ácido, sendo o erro máximo entre os resultados experimentais e os numéricos de 18%

Social, environmental, and epidemiological aspects of leprosy occurrence in children in a hyperendemic region of Brazil

Introduction This is a case-control study aiming to analyze the predictive factors for the occurrence of leprosy in contacts under 15 years of age, considering aspects related to the socio-environmental and epidemiological conditions in a hyperendemic municipality. Methods Cases (n = 30) consisted of children with leprosy who were household contacts of adults notified with leprosy between 2016 and 2018. The controls (n = 128) comprised neighborhood contacts, without symptoms of leprosy, living within a radius of less than 100 m of the households with cases. Demographic, social, environmental, and epidemiological variables were analyzed. The software SPSS, version 20, was used. Odds Ratio and statistical significance level of p ≤ 0.05 were considered for association analysis. In the logistic regression analysis, the variables with results ≤20% were selected. Results After adjustments, the predictive variables for the occurrence of leprosy were age between 8 and 14 years (OR adjust = 4.5; 95% CI: 1.70; 12.18) and a family history of leprosy (OR adjust = 5.2; 95% CI: 1.95; 14.13). Conclusions The predictive factors studied may favor the occurrence of leprosy in those most vulnerable to this disease in the child population; strategies such as the use of immune chemoprophylaxis are recommended, especially in hyperendemic regions, such as the state of Mato Grosso

Synthesis and characterization of an insoluble polymer based on polyamidoamine : Applications for the decontamination of metals in aqueous systems

We present a novel, insoluble, low-generation polyamidoamine (PAMAM)-based polymer. The monomer and polymer were characterized by fourier transform infrared spectroscopy, electrospray ionization mass spectrometry and thermogravimetric measurement, revealing that GO acryloyl-terminated PAMAM were synthesized and polymerized using ammonium persulfate as an initiator, producing a high-density PAMAM derivative (PAMAM-HD). PAMAM-HD was tested for its ability to remove Na(I), K(I), Ca(II), Mg(II), Cu(II), Mn(II), Cd(II), Pb(II) and Zn(II) ions from acidic, neutral and basic aqueous solutions. PAMAM-HD efficiently removed metals ions from all three solutions. The greatest absorption efficiency at neutral pH was observed against Cu(II), Cd(II) and Pb(II), and the experimental data were supported by the calculated K-d values. Our data could have a significant impact on water purification by providing an inexpensive and efficient polymer for the removal of metal ions

The Application of DNA-Biosensors and Differential Scanning Calorimetry to the Study of the DNA-Binding Agent Berenil

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