12 research outputs found

    Relationship between drying rates and mechanical properties in refractory concretes

    Get PDF
    The effect of drying rates on compressive strength was investigated in two aluminosilicate refractory concretes with different water content, which were cured at room temperature and dried at 3 heating rates (30, 40 and 50°C/h) up to 260ÂșC with different holding times. The results show that the lightweight refractory concrete developed better mechanical resistance with 48% of water content and heating rate of 40ÂșC/h, while for dense refractory concrete the best conditions were 12% of water content with heating rates of 30ÂșC/h, both during 2 hours of holding time. Se investigĂł el efecto de las velocidades de secado sobre la resistencia a la compresiĂłn en dos concretos refractarios silicoaluminosos con diferente contenido de agua, los cuales se curaron a temperatura ambiente y se secaron a 3 velocidades de calentamiento (30, 40 y 50°C/h) hasta 260°C con diferentes tiempos de permanencia. Los resultados muestran que el concreto refractario aislante desarrollĂł mejor resistencia con 48% de agua y velocidad de calentamiento de 40ÂșC/h, mientras que para el concreto refractario denso las mejores condiciones fueron 12% de agua y velocidad de calentamiento de 30ÂșC/h, ambos durante 2 horas de permanencia.&nbsp

    Relationwship between drying rates and mechanical properties in refractory concretes

    Get PDF
    Se investigĂł el efecto de las velocidades de secado sobre la resistencia a la compresiĂłn en dos concretos refractarios silicoaluminosos con diferente contenido de agua, los cuales se curaron a temperatura ambiente y se secaron a 3 velocidades de calentamiento (30, 40 y 50°C/h) hasta 260°C con diferentes tiempos de permanencia. Los resultados muestran que el concreto refractario aislante desarrollĂł mejor resistencia con 48% de agua y velocidad de calentamiento de 40ÂșC/h, mientras que para el concreto refractario denso las mejores condiciones fueron 12% de agua y velocidad de calentamiento de 30ÂșC/h, ambos durante 2 horas de permanencia

    Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

    Get PDF
    From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

    Get PDF
    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Diminishing benefits of urban living for children and adolescents’ growth and development

    Get PDF
    Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified
    corecore