13 research outputs found

    Reduction of Typical Diesel NOx Emissions by SCR-NH3 Using Metal-Exchanged Natural Zeolite and SBA-15 Catalysts.

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    In this work, the catalytic performance of clinoptilolite (CLIN) and SBA-15 catalysts, doped with Fe and Cu, was evaluated in the selective catalytic reduction of NO using NH3 as a reducing agent (SCR-NH3). Both Cu-CLIN and Fe-CLIN were obtained by ion-exchange using natural clinoptilolite zeolite originating from the Hrabovec deposit (northeast Slovakia region). Cu- SBA-15 and Fe-SBA-15 were prepared by impregnation into SBA-15 mesoporous synthesized silica. Standard catalytic activity tests were carried out on a bench-scale laboratory apparatus using a reaction mixture of a standard test. GHSV of 48,000 h1 was adopted based on the space velocity of a real NH3-SCR catalyst for diesel vehicles (100–550 C). All Cu-doped samples showed better NO conversion values than Fe-doped samples. Clinoptilolite catalysts were more active than those based on SBA-15. Maximum NO conversions of about 96% were observed for Cu-CLIN and Fe-CLIN at 350–400 C, respectively. Moreover, Fe-CLIN also showed higher stability in the presence of SO2 and water steam at 350 C. These results demonstrate the potential of metal-doped natural clinoptilolite to be used as cost-effective catalysts applied to the abatement of NOx emissions generated in automotive combustion processes.Partial funding for open access charge: Universidad de Málag

    Clinical characteristics and outcomes of patients hospitalized with COVID-19 in Brazil: Results from the Brazilian COVID-19 registry

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    Objectives: To describe the clinical characteristics, laboratory results, imaging findings, and in-hospital outcomes of COVID-19 patients admitted to Brazilian hospitals.Methods: A cohort study of laboratory-confirmed COVID-19 patients who were hospitalized from March 2020 to September 2020 in 25 hospitals. Data were collected from medical records using Research Electronic Data Capture (REDCap) tools. A multivariate Poisson regression model was used to assess the risk factors for in-hospital mortality. Results: For a total of 2,054 patients (52.6% male; median age of 58 years), the in-hospital mortality was 22.0%; this rose to 47.6% for those treated in the intensive care unit (ICU). Hypertension (52.9%), diabetes(29.2%), and obesity (17.2%) were the most prevalent comorbidities. Overall, 32.5% required invasive mechanical ventilation, and 12.1% required kidney replacement therapy. Septic shock was observed in 15.0%, nosocomial infection in 13.1%, thromboembolism in 4.1%, and acute heart failure in 3.6%. Age >= 65 years, chronic kidney disease, hypertension, C-reactive protein 100 mg/dL, platelet count < 100 =109/L, oxygen saturation < 90%, the need for supplemental oxygen, and invasive mechanical ventilation at admission were independently associated with a higher risk of in-hospital mortality. The overall use of antimicrobials was 87.9%. Conclusions: This study reveals the characteristics and in-hospital outcomes of hospitalized patients with confirmed COVID-19 in Brazil. Certain easily assessed parameters at hospital admission were independently associated with a higher risk of death

    POST-HARVEST QUALITY OF PEQUI (Caryocar brasiliense CAMB.) COLLECTED FROM THE PLANT OR AFTER NATURALLY FALLING OFF AND SUBJECTED TO SLOW AND QUICK FREEZING

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    ABSTRACT Soluble solids (SS), titratable acidity (TA), SS/TA ratio, pH, moisture, soluble sugars (SSU), total reducing sugars (RSU), and non-reducing sugars (NRS) were assessed in the pulp of pequi fruits collected at three ripening stages: from the plant, from the ground after naturally falling off, and collected from the ground three days after naturally falling off. The evaluation was performed after six months of freezer storage both for fruits subjected to quick freezing (liquid nitrogen followed by freezer) and slow freezing (straight into the freezer). The variables assessed were not influenced by the freezing method. The SS, TA, and RSU contents increased with the ripening stage, suggesting that the fruits collected from the plant are still immature and have lower quality than those collected after naturally falling off. Although considered mature when they fall off, fruits consumed three days after naturally falling off have better quality

    Hombre chinanteco de frente, 0618

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    Injúria pelo frio na qualidade pós-colheita de mangas cv. Palmer

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    Este trabalho objetivou estabelecer os binômios temperatura x tempo, que podem ocasionar injúria pelo frio em mangas 'Palmer'. Frutos colhidos no estádio "de vez" foram cuidadosamente transportados para laboratório, onde foram selecionados, padronizados quanto à coloração, ao tamanho e à ausência de injúrias, e tratados com fungicida antes de serem armazenados a 2 ºC, 5 ºC e 12 ºC, por até 28 dias. Os frutos foram avaliados semanalmente quanto à ocorrência de podridões, danos pelo frio, atividade respiratória, coloração da casca e da polpa, massa fresca, firmeza da polpa, teores de sólidos solúveis (SS) e de acidez titulável (AT), e relação SS/AT. Os resultados indicaram que os sintomas de injúrias pelo frio foram exteriorizados após 7 dias do armazenamento refrigerado a 2 ºC ou 5 ºC, com os frutos não diferindo quanto à gravidade dos danos. A presença dos danos não impediu o desenvolvimento da coloração característica da polpa, porém levou ao escurecimento da casca e afetou o amadurecimento normal dos frutos. Frutos armazenados a 12 ºC não apresentaram sinais de danos pelo frio ou prejuízos aos seus processos metabólicos normais
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