56 research outputs found

    Sources of unburned carbon in the fly ash produced from low-NOx pulverized coal combustion

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    Journal ArticleThe unburned carbon in the fly ash produced from low-NOx pulverized coal combustion is shown to consist of a mixture of soot and coal char. The soot was identified by the presence of chains or aggregates of 10-50-nm-diameter primary particles in electron microscope images of both laboratory samples and a sample of fly ash from a power plant operating low-NOx burners. Laboratory samples showed increasing carbon content with decreasing nitrogen oxide (NOx) concentration. The experiments included a high-NOx base case and four low-NOx cases consisting of (1) staged combustion with short (0.5 s) residence time, (2) staged combustion with long (1.5 s) residence time, (3) a low-NOx burner with slow mixing, and (4) reburning using coal as the reburning fuel. Comparison of the base case that used premixed coal and air with the long-residence-time staged combustion case shows a decrease in the NOx from over 900 ppm to below 200 ppm and an increase in the carbon in the ash from 4% to over 30%. The fly ash from staged combustion was a mixture of large soot aggregates, porous char, and spherical particles of mineral ash, whereas the ash from reburning lacked the large aggregates. For all laboratory conditions, the carbon content in the particle fraction with an aerodynamic diameter over 10 lm was higher than in the 1-2.5- lm-diameter fraction. Both soot aggregates and char contributed to the high carbon in the large particle fraction. The difference in carbon burnout between the two staging conditions was consistent with published soot oxidation rates. Both char burnout and soot formation need to be considered in studies of the carbon content of pulverized coal fly ash

    So That the People May Live (Hecel Lena Oyate Ki Nipi Kte): Lakota and Dakota Elder Women as Reservoirs of Life and Keepers of Knowledge about Health Protection and Diabetes Prevention

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    Around the world, Type 2 diabetes is on the rise, affecting adults and youth from societies in the throes of industrialization. Over time, uncontrolled diabetes can leave in its wake people facing renal failure, blindness, and heart disease, and communities daunted by new, chaotic phenomena. Westernized lifestyles are a recognized explanation for the escalating prevalence. The web of causation, however, may be broader and thicker, woven by complex interactions with environmental, sociological, and historical roots. The purpose of this participatory ethnographic study was to document, understand, and support Lakota and Dakota elder women’s beliefs and knowledge about health protection and diabetes prevention. In-depth interviews were conducted with nine elder women to learn: (1) about the factors attributable to diabetes, (2) about related narratives addressing health protection and diabetes prevention, and (3) how knowledge about health protection is shared. The elders saw diabetes as an outside, unnatural disorder, the contributing influences of which are external as well as internal. They offered narratives about chaos, restitution, testimony, and quests for cures and meaning. The elders connected health to traditional values and ways, the land, and memory. Reservoirs of wisdom reside in the knowledge systems of tribal elders who remember when diabetes was unknown. Health leaders at local and national levels would be wise to respect and draw upon this knowledge for guidance in program planning and policy development

    Giant Enhancement of Magnetic Anisotropy in Ultrathin Manganite Films via Nanoscale 1D Periodic Depth Modulation

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    The relatively low magnetocrystalline anisotropy (MCA) in strongly correlated manganites (La,Sr)MnO3 has been a major hurdle for implementing them in spintronic applications. Here we report an unusual, giant enhancement of in-plane MCA in 6 nm La0.67Sr0.33MnO3 (LSMO) films grown on (001) SrTiO3 substrates when the top 2 nm is patterned into periodic stripes of 100 or 200 nm width. Planar Hall effect measurements reveal an emergent uniaxial anisotropy superimposed on one of the original biaxial easy axes for unpatterned LSMO along (110) directions, with a 50-fold enhanced anisotropy energy density of 5.6 × 106 erg/cm3 within the nanostripes, comparable to the value for cobalt. The magnitude and direction of the uniaxial anisotropy exclude shape anisotropy and the step edge effect as its origin. High resolution transmission electron microscopy studies reveal a nonequilibrium strain distribution and drastic suppression in the c-axis lattice constant within the nanostructures, which is the driving mechanism for the enhanced uniaxial MCA, as suggested by first-principles density functional calculations

    Long Beach Earthquake and Protection Against Future Earthquakes -- Summary of Report by Joint Technical Committee on Earthquake Protection, Dr. Robert A. Millikan, Chairman

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    To the Public of the Pacific Southwest: In response to official requests from many representative technical and civic organizations, the Joint Technical Committee on Earthquake Protection was organized after the earthquake of March 10, 1933 to consider ways and means of minimizing loss of life and property damage in the event of another earthquake of equal or greater intensity. We now present to you, in the form of this summarized report, our belief as to the seismic hazard in this region and our opinion as to the proper balance between the degree of protection to be afforded life and property and the cost of providing such protection. We sincerely hope that the lessons of the Long Beach earthquake will not be forgotten as were the lessons which should have been fixed indelibly in the minds of all by the earthquakes of the past. Joint Technical Committee on Earthquake Protection. Robert A. Millikan, Chairman. June 7-1933

    Four consecutive yearly point-prevalence studies in Wales indicate lack of improvement in sepsis care on the wards

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    The ‘Sepsis Six’ bundle was promoted as a deliverable tool outside of the critical care settings, but there is very little data available on the progress and change of sepsis care outside the critical care environment in the UK. Our aim was to compare the yearly prevalence, outcome and the Sepsis Six bundle compliance in patients at risk of mortality from sepsis in non-intensive care environments. Patients with a National Early Warning Score (NEWS) of 3 or above and suspected or proven infection were enrolled into four yearly 24-h point prevalence studies, carried out in fourteen hospitals across Wales from 2016 to 2019. We followed up patients to 30 days between 2016–2019 and to 90 days between 2017 and 2019. Out of the 26,947 patients screened 1651 fulfilled inclusion criteria and were recruited. The full ‘Sepsis Six’ care bundle was completed on 223 (14.0%) occasions, with no significant difference between the years. On 190 (11.5%) occasions none of the bundle elements were completed. There was no significant correlation between bundle element compliance, NEWS or year of study. One hundred and seventy (10.7%) patients were seen by critical care outreach; the ‘Sepsis Six’ bundle was completed significantly more often in this group (54/170, 32.0%) than for patients who were not reviewed by critical care outreach (168/1385, 11.6%; p < 0.0001). Overall survival to 30 days was 81.7% (1349/1651), with a mean survival time of 26.5 days (95% CI 26.1–26.9) with no difference between each year of study. 90-day survival for years 2017–2019 was 74.7% (949/1271), with no difference between the years. In multivariate regression we identified older age, heart failure, recent chemotherapy, higher frailty score and do not attempt cardiopulmonary resuscitation orders as significantly associated with increased 30-day mortality. Our data suggests that despite efforts to increase sepsis awareness within the NHS, there is poor compliance with the sepsis care bundles and no change in the high mortality over the study period. Further research is needed to determine which time-sensitive ward-based interventions can reduce mortality in patients with sepsis and how can these results be embedded to routine clinical practice

    Case report: maternal mosaicism resulting in inheritance of a novel GATA6 mutation causing pancreatic agenesis and neonatal diabetes mellitus.

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    Haploinsufficiency of the GATA6 transcription factor gene was recently found to be the most common cause of pancreatic agenesis, a rare cause of neonatal diabetes mellitus. Although most cases are de novo, we describe three siblings with inherited GATA6 haploinsufficiency and the rare finding of parental mosaicism.This article is freely available via Open Access. Click on the Additional Link above to access the full-text via the publisher's site

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Five insights from the Global Burden of Disease Study 2019

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    The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a rules-based synthesis of the available evidence on levels and trends in health outcomes, a diverse set of risk factors, and health system responses. GBD 2019 covered 204 countries and territories, as well as first administrative level disaggregations for 22 countries, from 1990 to 2019. Because GBD is highly standardised and comprehensive, spanning both fatal and non-fatal outcomes, and uses a mutually exclusive and collectively exhaustive list of hierarchical disease and injury causes, the study provides a powerful basis for detailed and broad insights on global health trends and emerging challenges. GBD 2019 incorporates data from 281 586 sources and provides more than 3.5 billion estimates of health outcome and health system measures of interest for global, national, and subnational policy dialogue. All GBD estimates are publicly available and adhere to the Guidelines on Accurate and Transparent Health Estimate Reporting. From this vast amount of information, five key insights that are important for health, social, and economic development strategies have been distilled. These insights are subject to the many limitations outlined in each of the component GBD capstone papers.Peer reviewe

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
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