12 research outputs found

    Syngas Production, Storage, Compression and Use in Gas Turbines

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    This chapter analyses syngas production through pyrolysis and gasification, its compression and its use in gas turbines. Syngas compression can be performed during or after thermal treatment processes. Important points are discussed related to syngas ignition, syngas explosion limit at high temperatures and high pressures and syngas combustion kinetics. Kinetic aspects influence ignition and final emissions which are obtained at the completion of the combustion process. The chapter is organized into four subsections, dealing with (1) innovative syngas production plants, (2) syngas compressors and compression process, (3) syngas ignition in both heterogeneous and homogeneous systems and (4) syngas combustion kinetics and experimental methods. Particular attention is given to ignition regions that affect the kinetics, namely systems that operate at temperatures higher than 1000 K can have strong ignition, whereas those operating at lower temperatures have weak ignition. Keywords: Pyrogas Pyrolysis Ignition Syngas Compression GasificationacceptedVersio

    Recommendations for folate intake in women: implications for public health strategies Recomendações para ingestão de folato por mulheres: implicações para as estratégias de saúde pública

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    Folate deficiency has been associated with anemia and other adverse outcomes in pregnancy such as neural tube defects. The current recommendations for prevention of such outcomes are difficult to achieve through diet only, and folic acid supplementation and food fortification are feasible public health strategies. However, it is necessary to determine the usual diet and supplement use among women of reproductive age, including an accurate assessment of other dietary micronutrients. In addition to the beneficial effects observed in randomized clinical trials, health risks to the population have also been widely evaluated and discussed in the scientific community: for a minority to benefit from fortification programs, many are exposed to high folic acid intake levels.<br>A deficiência de ácido fólico tem sido associada ao risco de anemia e outros desfechos adversos na gravidez, como os defeitos no tubo neural. As recomendações atuais para prevenção de tais agravos são consideradas difíceis de se alcançar apenas por meio da dieta, e a suplementação com ácido fólico e a adição dessa vitamina a alimentos sob a forma de fortificação representam esforços centrais no controle da sua deficiência. É necessário, porém, conhecer as características da dieta habitual e o uso de suplementos entre mulheres em idade reprodutiva, com avaliação adequada de outros nutrientes da dieta. Ao lado dos efeitos benéficos observados em ensaios clínicos aleatórios controlados, riscos à saúde da população têm sido avaliados e largamente discutidos no meio científico: para que uma fração seja beneficiada pela fortificação, centenas de pessoas são expostas a quantidades de ácido fólico talvez elevadas e provavelmente incomuns, em quantidade e apresentação química, ao organismo humano

    Environmental signals rather than layered ontogeny imprint the function of type 2 conventional dendritic cells in young and adult mice

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    Oxygen in metabolic dysfunction and its therapeutic relevance

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    Significance: In recent years, a number of studies have shown altered oxygen partial pressure at a tissue level in metabolic disorders, and some researchers have considered oxygen to be a (macro) nutrient. Oxygen availability may be compromised in obesity and several other metabolism-related pathological conditions, including sleep apnea-hypopnea syndrome, the metabolic syndrome (which is a set of conditions), type 2 diabetes, cardiovascular disease and cancer. Recent Advances: Strategies designed to reduce adiposity and its accompanying disorders have been mainly centered on nutritional interventions and physical activity programs. However, novel therapies are needed since these approaches have not been sufficient to counteract the worldwide increasing rates of metabolic disorders. In this regard, intermittent hypoxia training and hyperoxia could be potential treatments through oxygen-related adaptations. Moreover, living at high altitude may have a protective effect against the development of abnormal metabolic conditions. In addition, oxygen delivery systems may be of therapeutic value for supplying the tissue-specific oxygen requirements. Critical Issues: Precise in vivo methods to measure oxygenation are vital to disentangle some of the controversies related to this research area. Furthermore, it is evident that there is a growing need for novel in vitro models to study the potential pathways involved in metabolic dysfunction in order to find appropriate therapeutic targets. Future directions: Based on the existing evidence, it is suggested that oxygen availability has a key role in obesity and related comorbidities. Oxygen should be considered in relation to potential therapeutic strategies in the treatment and prevention of metabolic disorders
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