| 1. |
- Abbafati, Cristiana, et al.
(författare)
-
- 2020
-
Tidskriftsartikel (refereegranskat)
|
|
| 2. |
- Lozano, Rafael, et al.
(författare)
-
Measuring progress from 1990 to 2017 and projecting attainment to 2030 of the health-related Sustainable Development Goals for 195 countries and territories: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
-
Ingår i: The Lancet. - : Elsevier. - 1474-547X .- 0140-6736. ; 392:10159, s. 2091-2138
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Efforts to establish the 2015 baseline and monitor early implementation of the UN Sustainable Development Goals (SDGs) highlight both great potential for and threats to improving health by 2030. To fully deliver on the SDG aim of “leaving no one behind”, it is increasingly important to examine the health-related SDGs beyond national-level estimates. As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), we measured progress on 41 of 52 health-related SDG indicators and estimated the health-related SDG index for 195 countries and territories for the period 1990–2017, projected indicators to 2030, and analysed global attainment. Methods: We measured progress on 41 health-related SDG indicators from 1990 to 2017, an increase of four indicators since GBD 2016 (new indicators were health worker density, sexual violence by non-intimate partners, population census status, and prevalence of physical and sexual violence [reported separately]). We also improved the measurement of several previously reported indicators. We constructed national-level estimates and, for a subset of health-related SDGs, examined indicator-level differences by sex and Socio-demographic Index (SDI) quintile. We also did subnational assessments of performance for selected countries. To construct the health-related SDG index, we transformed the value for each indicator on a scale of 0–100, with 0 as the 2·5th percentile and 100 as the 97·5th percentile of 1000 draws calculated from 1990 to 2030, and took the geometric mean of the scaled indicators by target. To generate projections through 2030, we used a forecasting framework that drew estimates from the broader GBD study and used weighted averages of indicator-specific and country-specific annualised rates of change from 1990 to 2017 to inform future estimates. We assessed attainment of indicators with defined targets in two ways: first, using mean values projected for 2030, and then using the probability of attainment in 2030 calculated from 1000 draws. We also did a global attainment analysis of the feasibility of attaining SDG targets on the basis of past trends. Using 2015 global averages of indicators with defined SDG targets, we calculated the global annualised rates of change required from 2015 to 2030 to meet these targets, and then identified in what percentiles the required global annualised rates of change fell in the distribution of country-level rates of change from 1990 to 2015. We took the mean of these global percentile values across indicators and applied the past rate of change at this mean global percentile to all health-related SDG indicators, irrespective of target definition, to estimate the equivalent 2030 global average value and percentage change from 2015 to 2030 for each indicator. Findings: The global median health-related SDG index in 2017 was 59·4 (IQR 35·4–67·3), ranging from a low of 11·6 (95% uncertainty interval 9·6–14·0) to a high of 84·9 (83·1–86·7). SDG index values in countries assessed at the subnational level varied substantially, particularly in China and India, although scores in Japan and the UK were more homogeneous. Indicators also varied by SDI quintile and sex, with males having worse outcomes than females for non-communicable disease (NCD) mortality, alcohol use, and smoking, among others. Most countries were projected to have a higher health-related SDG index in 2030 than in 2017, while country-level probabilities of attainment by 2030 varied widely by indicator. Under-5 mortality, neonatal mortality, maternal mortality ratio, and malaria indicators had the most countries with at least 95% probability of target attainment. Other indicators, including NCD mortality and suicide mortality, had no countries projected to meet corresponding SDG targets on the basis of projected mean values for 2030 but showed some probability of attainment by 2030. For some indicators, including child malnutrition, several infectious diseases, and most violence measures, the annualised rates of change required to meet SDG targets far exceeded the pace of progress achieved by any country in the recent past. We found that applying the mean global annualised rate of change to indicators without defined targets would equate to about 19% and 22% reductions in global smoking and alcohol consumption, respectively; a 47% decline in adolescent birth rates; and a more than 85% increase in health worker density per 1000 population by 2030. Interpretation: The GBD study offers a unique, robust platform for monitoring the health-related SDGs across demographic and geographic dimensions. Our findings underscore the importance of increased collection and analysis of disaggregated data and highlight where more deliberate design or targeting of interventions could accelerate progress in attaining the SDGs. Current projections show that many health-related SDG indicators, NCDs, NCD-related risks, and violence-related indicators will require a concerted shift away from what might have driven past gains—curative interventions in the case of NCDs—towards multisectoral, prevention-oriented policy action and investments to achieve SDG aims. Notably, several targets, if they are to be met by 2030, demand a pace of progress that no country has achieved in the recent past. The future is fundamentally uncertain, and no model can fully predict what breakthroughs or events might alter the course of the SDGs. What is clear is that our actions—or inaction—today will ultimately dictate how close the world, collectively, can get to leaving no one behind by 2030.
|
|
| 3. |
- Murray, Christopher J. L., et al.
(författare)
-
Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
-
Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1995-2051
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation.
|
|
| 4. |
- Stanaway, Jeffrey D., et al.
(författare)
-
Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017
- 2018
-
Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1923-1994
-
Tidskriftsartikel (refereegranskat)abstract
- Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk- outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
|
|
| 5. |
- Feigin, Valery L., et al.
(författare)
-
Global, regional, and national burden of neurological disorders, 1990–2016 : a systematic analysis for the Global Burden of Disease Study 2016
- 2019
-
Ingår i: Lancet Neurology. - : Elsevier. - 1474-4422 .- 1474-4465. ; 18:5, s. 459-480
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Neurological disorders are increasingly recognised as major causes of death and disability worldwide. The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 is to provide the most comprehensive and up-to-date estimates of the global, regional, and national burden from neurological disorders.Methods: We estimated prevalence, incidence, deaths, and disability-adjusted life-years (DALYs; the sum of years of life lost [YLLs] and years lived with disability [YLDs]) by age and sex for 15 neurological disorder categories (tetanus, meningitis, encephalitis, stroke, brain and other CNS cancers, traumatic brain injury, spinal cord injury, Alzheimer's disease and other dementias, Parkinson's disease, multiple sclerosis, motor neuron diseases, idiopathic epilepsy, migraine, tension-type headache, and a residual category for other less common neurological disorders) in 195 countries from 1990 to 2016. DisMod-MR 2.1, a Bayesian meta-regression tool, was the main method of estimation of prevalence and incidence, and the Cause of Death Ensemble model (CODEm) was used for mortality estimation. We quantified the contribution of 84 risks and combinations of risk to the disease estimates for the 15 neurological disorder categories using the GBD comparative risk assessment approach.Findings: Globally, in 2016, neurological disorders were the leading cause of DALYs (276 million [95% UI 247–308]) and second leading cause of deaths (9·0 million [8·8–9·4]). The absolute number of deaths and DALYs from all neurological disorders combined increased (deaths by 39% [34–44] and DALYs by 15% [9–21]) whereas their age-standardised rates decreased (deaths by 28% [26–30] and DALYs by 27% [24–31]) between 1990 and 2016. The only neurological disorders that had a decrease in rates and absolute numbers of deaths and DALYs were tetanus, meningitis, and encephalitis. The four largest contributors of neurological DALYs were stroke (42·2% [38·6–46·1]), migraine (16·3% [11·7–20·8]), Alzheimer's and other dementias (10·4% [9·0–12·1]), and meningitis (7·9% [6·6–10·4]). For the combined neurological disorders, age-standardised DALY rates were significantly higher in males than in females (male-to-female ratio 1·12 [1·05–1·20]), but migraine, multiple sclerosis, and tension-type headache were more common and caused more burden in females, with male-to-female ratios of less than 0·7. The 84 risks quantified in GBD explain less than 10% of neurological disorder DALY burdens, except stroke, for which 88·8% (86·5–90·9) of DALYs are attributable to risk factors, and to a lesser extent Alzheimer's disease and other dementias (22·3% [11·8–35·1] of DALYs are risk attributable) and idiopathic epilepsy (14·1% [10·8–17·5] of DALYs are risk attributable).Interpretation: Globally, the burden of neurological disorders, as measured by the absolute number of DALYs, continues to increase. As populations are growing and ageing, and the prevalence of major disabling neurological disorders steeply increases with age, governments will face increasing demand for treatment, rehabilitation, and support services for neurological disorders. The scarcity of established modifiable risks for most of the neurological burden demonstrates that new knowledge is required to develop effective prevention and treatment strategies.Funding: Bill & Melinda Gates Foundation.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- James, SL, et al.
(författare)
-
Global injury morbidity and mortality from 1990 to 2017: results from the Global Burden of Disease Study 2017
- 2020
-
Ingår i: Injury prevention : journal of the International Society for Child and Adolescent Injury Prevention. - : BMJ. - 1475-5785. ; 26:SUPP_1Supp 1, s. 96-114
-
Tidskriftsartikel (refereegranskat)abstract
- Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries.MethodsWe reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs).FindingsIn 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505).InterpretationInjuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.
|
|
| 9. |
|
|
| 10. |
- Kinyoki, DK, et al.
(författare)
-
Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017
- 2020
-
Ingår i: Nature medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 26:5, s. 750-759
-
Tidskriftsartikel (refereegranskat)abstract
- A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic.
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
- Burstein, R., et al.
(författare)
-
Mapping 123 million neonatal, infant and child deaths between 2000 and 2017
- 2019
-
Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 574:7778, s. 353-358
-
Tidskriftsartikel (refereegranskat)abstract
- Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations. © 2019, The Author(s).
|
|
| 15. |
|
|
| 16. |
- Frank, TD, et al.
(författare)
-
Global, regional, and national incidence, prevalence, and mortality of HIV, 1980-2017, and forecasts to 2030, for 195 countries and territories: a systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017
- 2019
-
Ingår i: The lancet. HIV. - 2352-3018. ; 6:12, s. E831-E859
-
Tidskriftsartikel (refereegranskat)
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Nichols, Emma, et al.
(författare)
-
Global, regional, and national burden of Alzheimer's disease and other dementias, 1990-2016 : a systematic analysis for the Global Burden of Disease Study 2016
- 2019
-
Ingår i: Lancet Neurology. - : Elsevier. - 1474-4422 .- 1474-4465. ; 18:1, s. 88-106
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The number of individuals living with dementia is increasing, negatively affecting families, communities, and health-care systems around the world. A successful response to these challenges requires an accurate understanding of the dementia disease burden. We aimed to present the first detailed analysis of the global prevalence, mortality, and overall burden of dementia as captured by the Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study 2016, and highlight the most important messages for clinicians and neurologists.Methods: GBD 2016 obtained data on dementia from vital registration systems, published scientific literature and surveys, and data from health-service encounters on deaths, excess mortality, prevalence, and incidence from 195 countries and territories from 1990 to 2016, through systematic review and additional data-seeking efforts. To correct for differences in cause of death coding across time and locations, we modelled mortality due to dementia using prevalence data and estimates of excess mortality derived from countries that were most likely to code deaths to dementia relative to prevalence. Data were analysed by standardised methods to estimate deaths, prevalence, years of life lost (YLLs), years of life lived with disability (YLDs), and disability-adjusted life-years (DALYs; computed as the sum of YLLs and YLDs), and the fractions of these metrics that were attributable to four risk factors that met GBD criteria for assessment (high body-mass index [BMI], high fasting plasma glucose, smoking, and a diet high in sugarsweetened beverages).Findings: In 2016, the global number of individuals who lived with dementia was 43.8 million (95% uncertainty interval [UI] 3 7. 8-51.0), increased from 20.2 million (17. 4-23 5) in 1990. This increase of 117% (95% UI 114-121) contrasted with a minor increase in age-standardised prevalence of 1.7% (1.0-2.4), from 701 cases (95% UI 602-815) per 100 000 population in 1990 to 712 cases (614-828) per 100 000 population in 2016. More women than men had dementia in 2016 (27.0 million, 95% UI 23 .3-31. 4, vs 16.8 million, 14.4-19.6), and dementia was the fifth leading cause of death globally, accounting for 2.4 million (95% UI 2.1-2.8) deaths. Overall, 28.8 million (95% UI 24. 5-34. 0) DALYs were attributed to dementia; 6.4 million (95% UI 3 .4-10. 5) of these could be attributed to the modifiable GBD risk factors of high BMI, high fasting plasma glucose, smoking, and a high intake of sugar-sweetened beverages.Interpretation: The global number of people living with dementia more than doubled from 1990 to 2016, mainly due to increases in population ageing and growth. Although differences in coding for causes of death and the heterogeneity in case-ascertainment methods constitute major challenges to the estimation of the burden of dementia, future analyses should improve on the methods for the correction of these biases. Until breakthroughs are made in prevention or curative treatment, dementia will constitute an increasing challenge to health-care systems worldwide.
|
|
| 21. |
|
|
| 22. |
- Sepanlou, Sadaf G., et al.
(författare)
-
The global, regional, and national burden of cirrhosis by cause in 195 countries and territories, 1990-2017 : a systematic analysis for the Global Burden of Disease Study 2017
- 2020
-
Ingår i: The Lancet Gastroenterology & Hepatology. - 2468-1253. ; 5:3, s. 245-266
-
Tidskriftsartikel (refereegranskat)abstract
- Background Cirrhosis and other chronic liver diseases (collectively referred to as cirrhosis in this paper) are a major cause of morbidity and mortality globally, although the burden and underlying causes differ across locations and demographic groups. We report on results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 on the burden of cirrhosis and its trends since 1990, by cause, sex, and age, for 195 countries and territories. Methods We used data from vital registrations, vital registration samples, and verbal autopsies to estimate mortality. We modelled prevalence of total, compensated, and decompensated cirrhosis on the basis of hospital and claims data. Disability-adjusted life-years (DALYs) were calculated as the sum of years of life lost due to premature death and years lived with disability. Estimates are presented as numbers and age-standardised or age-specific rates per 100 000 population, with 95% uncertainty intervals (UIs). All estimates are presented for five causes of cirrhosis: hepatitis B, hepatitis C, alcohol-related liver disease, non-alcoholic steatohepatitis (NASH), and other causes. We compared mortality, prevalence, and DALY estimates with those expected according to the Socio-demographic Index (SDI) as a proxy for the development status of regions and countries. Findings In 2017, cirrhosis caused more than 1.32 million (95% UI 1.27-1.45) deaths (440000 [416 000-518 000; 33.3%] in females and 883 000 [838 000-967 000; 66.7%] in males) globally, compared with less than 899 000 (829 000-948 000) deaths in 1990. Deaths due to cirrhosis constituted 2.4% (2.3-2.6) of total deaths globally in 2017 compared with 1.9% (1.8-2.0) in 1990. Despite an increase in the number of deaths, the age-standardised death rate decreased from 21.0 (19.2-22.3) per 100 000 population in 1990 to 16.5 (15.8-18-1) per 100 000 population in 2017. Sub-Saharan Africa had the highest age-standardised death rate among GBD super-regions for all years of the study period (32.2 [25.8-38.6] deaths per 100 000 population in 2017), and the high-income super-region had the lowest (10.1 [9.8-10-5] deaths per 100 000 population in 2017). The age-standardised death rate decreased or remained constant from 1990 to 2017 in all GBD regions except eastern Europe and central Asia, where the age-standardised death rate increased, primarily due to increases in alcohol-related liver disease prevalence. At the national level, the age-standardised death rate of cirrhosis was lowest in Singapore in 2017 (3.7 [3.3-4.0] per 100 000 in 2017) and highest in Egypt in all years since 1990 (103.3 [64.4-133.4] per 100 000 in 2017). There were 10.6 million (10.3-10.9) prevalent cases of decompensated cirrhosis and 112 million (107-119) prevalent cases of compensated cirrhosis globally in 2017. There was a significant increase in age-standardised prevalence rate of decompensated cirrhosis between 1990 and 2017. Cirrhosis caused by NASH had a steady age-standardised death rate throughout the study period, whereas the other four causes showed declines in age-standardised death rate. The age-standardised prevalence of compensated and decompensated cirrhosis due to NASH increased more than for any other cause of cirrhosis (by 33.2% for compensated cirrhosis and 54.8% for decompensated cirrhosis) over the study period. From 1990 to 2017, the number of prevalent cases snore than doubled for compensated cirrhosis due to NASH and more than tripled for decompensated cirrhosis due to NASH. In 2017, age-standardised death and DALY rates were lower among countries and territories with higher SDI. Interpretation Cirrhosis imposes a substantial health burden on many countries and this burden has increased at the global level since 1990, partly due to population growth and ageing. Although the age-standardised death and DALY rates of cirrhosis decreased from 1990 to 2017, numbers of deaths and DALYs and the proportion of all global deaths due to cirrhosis increased. Despite the availability of effective interventions for the prevention and treatment of hepatitis B and C, they were still the main causes of cirrhosis burden worldwide, particularly in low-income countries. The impact of hepatitis B and C is expected to be attenuated and overtaken by that of NASH in the near future. Cost-effective interventions are required to continue the prevention and treatment of viral hepatitis, and to achieve early diagnosis and prevention of cirrhosis due to alcohol-related liver disease and NASH.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
- Danandeh Mehr, Ali, et al.
(författare)
-
VMD-GP : A New Evolutionary Explicit Model for Meteorological Drought Prediction at Ungauged Catchments
- 2023
-
Ingår i: Water (Switzerland). - 2073-4441. ; 15:15
-
Tidskriftsartikel (refereegranskat)abstract
- Meteorological drought is a common hydrological hazard that affects human life. It is one of the significant factors leading to water and food scarcity. Early detection of drought events is necessary for sustainable agricultural and water resources management. For the catchments with scarce meteorological observatory stations, the lack of observed data is the main leading cause of unfeasible sustainable watershed management plans. However, various earth science and environmental databases are available that can be used for hydrological studies, even at a catchment scale. In this study, the Global Drought Monitoring (GDM) data repository that provides real-time monthly Standardized Precipitation and Evapotranspiration Index (SPEI) across the globe was used to develop a new explicit evolutionary model for SPEI prediction at ungauged catchments. The proposed model, called VMD-GP, uses an inverse distance weighting technique to transfer the GDM data to the desired area. Then, the variational mode decomposition (VMD), in conjunction with state-of-the-art genetic programming, is implemented to map the intrinsic mode functions of the GMD series to the subsequent SPEI values in the study area. The suggested model was applied for the month-ahead prediction of the SPEI series at Erbil, Iraq. The results showed a significant improvement in the prediction accuracy over the classic GP and gene expression programming models developed as the benchmarks.
|
|
| 27. |
- Farhang, P., et al.
(författare)
-
Combined design of VSC-HVDC and PSS controllers for LFO damping enhancement
- 2014
-
Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE Publications. - 1477-0369 .- 0142-3312. ; 36:4, s. 529-540
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper is to present a novel combined design of the voltage source converter–high voltage direct current (VSC-HVDC) and the power system stabilizer (PSS) controllers to obtain a better dynamical response. The proposed technique is applied to enhance the damping of the power system low-frequency oscillations (LFOs) and results are compared with traditional design. A fuzzy logic controller is designed for PSS (FPSS). Then, a chaotic optimization algorithm, which has a strong ability for finding the most optimistic results, is employed, in presence of FPSS, to search for optimal VSC-HVDC output feedback controller parameters. Moreover, a singular value decomposition method is utilized to select the most effective damping control signal of the VSC-HVDC output feedback controllers. The novel proposed controllers are evaluated on an AC/DC power system. The simulation results demonstrate that the combined controllers have an excellent capability for damping power system LFOs and greatly enhance the dynamic stability of the power system. Also, the system performance analysis under different operating conditions and some performance indices show the effectiveness of the proposed controllers. The benefit of the suggested procedure is greatly improving the dynamic response of the system. In addition, the overshoots, undershoots and the settling times are dramatically reduced by applying the proposed method.
|
|
| 28. |
|
|
| 29. |
- Graetz, N, et al.
(författare)
-
Mapping disparities in education across low- and middle-income countries
- 2020
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 577:77907789, s. 235-238
-
Tidskriftsartikel (refereegranskat)abstract
- Educational attainment is an important social determinant of maternal, newborn, and child health1–3. As a tool for promoting gender equity, it has gained increasing traction in popular media, international aid strategies, and global agenda-setting4–6. The global health agenda is increasingly focused on evidence of precision public health, which illustrates the subnational distribution of disease and illness7,8; however, an agenda focused on future equity must integrate comparable evidence on the distribution of social determinants of health9–11. Here we expand on the available precision SDG evidence by estimating the subnational distribution of educational attainment, including the proportions of individuals who have completed key levels of schooling, across all low- and middle-income countries from 2000 to 2017. Previous analyses have focused on geographical disparities in average attainment across Africa or for specific countries, but—to our knowledge—no analysis has examined the subnational proportions of individuals who completed specific levels of education across all low- and middle-income countries12–14. By geolocating subnational data for more than 184 million person-years across 528 data sources, we precisely identify inequalities across geography as well as within populations.
|
|
| 30. |
|
|
| 31. |
- Mancuso, Vincenzo, et al.
(författare)
-
Results from running an experiment as a service platform for mobile broadband networks in Europe
- 2019
-
Ingår i: Computer Communications. - : Elsevier. - 0140-3664 .- 1873-703X. ; 33, s. 89-101
-
Tidskriftsartikel (refereegranskat)abstract
- In this article we present a selection from a vast range of experiments run with MONROE, our open experiment as a service (EaaS) platform for measurements and experimentation in Mobile Broadband Networks. We show that the platform can be used to benchmark network performance in a repeatable and controlled manner thanks to the collection of a rich set of geotagged metadata and the execution of discretionary user experiments. Indeed, with the sheer amount of data collected from 12 commercial mobile operators across Europe, MONROE offers an unprecedented opportunity to monitor, analyze and ultimately improve the status of current and future mobile broadband networks. Besides, we show how flexibly the platform allows combining metadata and experimental data series during the experiments or by means of post-processing, and show results produced by our own experiments as well as comment on results obtained by external research groups and developers that have been granted access to our platform.
|
|
| 32. |
- Naeimi, Behrouz, et al.
(författare)
-
Screening Candida auris through a multiplex stepwise PCR algorithm directly from clinical samples of patients suspected of otomycosis in south of Iran; Detection of five cases
- 2024
-
Ingår i: MYCOSES. - 0933-7407 .- 1439-0507. ; 67:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Otomycosis is an infection of the external auditory canal caused by molds and yeasts with descending frequency. Laboratory diagnosis is usually confirmed by microscopy and culture. However, they are not specific enough to reliably differentiate the causative agents, especially for rare pathogens such as Candida auris. The purpose of the current study was to the molecular screening of C. auris species from direct clinical samples of patients with suspected otomycosis in Southern of Iran.Materials and Methods: A total of 221 ear aspirates collected from 221 patients with suspected otomycosis over a four-year period. All the ear aspirations were examined with pan-fungal primers, then those with a positive result was included in two separate reaction mixtures simultaneously to identify the most clinically relevant Aspergillus and Candida species. The validity of positive samples for C. auris was assessed by sequencing.Results: Of the 189 pan-fungal positive PCRs, 78 and 39 specimens contained Aspergillus spp. and Candida spp., respectively. Furthermore, 65 specimens showed simultaneous positive bands in both Candida and Aspergillus species-specific multiplex PCR including five samples/patients with positive result for C. auris (5/189; 2.6%). Four out of five cases with C. auris species-specific PCR were reconfirmed by sequencing, while none were positive for C. auris in culture.Conclusion: Unfortunately, due to high treatment failure rates of antifungal classes against C. auris species, rapid and accurate identification of patients colonised with C. auris is critical to overcome the challenge of preventing transmission. This PCR assay can be successfully applied for rapid and accurate detection of C. auris directly in patient samples and is able to differentiate C. auris from closely related Candida species.
|
|
| 33. |
|
|
| 34. |
- Rajiullah, Mohammad, 1981-, et al.
(författare)
-
Mobile Network Performance during the COVID-19 Outbreak from a Testbed Perspective
- 2020
-
Konferensbidrag (refereegranskat)abstract
- COVID-19 has changed our lives and continues to have a drastic impact. It forces us to impose restrictive social distancing measures and leads us to rely more on the Internet. Mobile networks become one of the major means to access the Internet for most of us. We investigate the performance of 9 mobile networks in Europe around the time when restrictions were imposed, considering web QoE, throughput, RTT, and signal coverage. Our results show countries’ mobile networks are impacted by COVID-19 (as high as 46 % increase in page load time) at different times based on the outbreak timelines in these countries. Moreover, we find that operators responded properly and the network performance is back to the pre-COVID-19 times.
|
|
| 35. |
- Rajiullah, Mohammad, 1981-, et al.
(författare)
-
Web Experience in Mobile Networks : Lessons from Two Million Page Visits
- 2019
-
Konferensbidrag (refereegranskat)abstract
- Measuring and characterizing web page performance is a challeng- ing task. When it comes to the mobile world, the highly varying technology characteristics coupled with the opaque network con- figuration make it even more difficult. Aiming at reproducibility, we present a large scale empirical study of web page performance collected in eleven commercial mobile networks spanning four countries. By digging into measurement from nearly two million web browsing sessions, we shed light on the impact of different web protocols, browsers, and mobile technologies on the web per- formance. We found that the impact of mobile broadband access is sizeable. For example, the median page load time using mobile broadband increases by a third compared to wired access. Mobility clearly stresses the system, with handover causing the most evi- dent performance penalties. Contrariwise, our measurements show that the adoption of HTTP/2 and QUIC has practically negligible impact. To understand the intertwining of all parameters, we adopt state-of-the-art statistical methods to identify the significance of different factors on the web performance. Our analysis confirms the importance of access technology and mobility context as well as webpage composition and browser. Our work highlights the importance of large-scale measurements. Even with our controlled setup, the complexity of the mobile web ecosystem is challenging to untangle. For this, we are releasing the dataset as open data for validation and further research.
|
|
| 36. |
|
|
| 37. |
- Safari, Aswo, et al.
(författare)
-
A search and deliberation framework for understanding consumers’ foreign online purchasing
- 2016
-
Ingår i: Extending the Business Network Approach. - London : Palgrave Macmillan. - 9781137537652 - 9781137537638 ; , s. 211-226
-
Bokkapitel (refereegranskat)abstract
- Information technology (IT) as an international marketing tool has been acknowledged in several studies (Beccera et al. 2013; Chang and Chen 2008; Jarvenpaa et al. 2000; Mukherjee and Nath 2007; Safari et al. 2013), and the Internet as an alternative path for firm internationalisation has been explored recently (Kim 2003; Lim et al. 2004; Pezderka and Sinkovics 2011; Sinkovics et al. 2013; Yamin and Sinkovics 2006). Similarly, consumers’ domestic online purchasing behaviour has been investigated extensively in the last two decades (e.g., Beldad et al. 2010; Jarvenpaa et al. 2000; Mukherjee and Nath; 2007; Sabiote et al. 2012). These studies have been aimed at understanding the relationship between consumers and retailers on the Internet, usually where both parties are physically located within the same country. International business and marketing scholars have also extensively studied the phenomenon of firm online internationalisation, that is, ‘the conduct of business transactions across national boundaries, where the “crossing” of national boundaries takes place in the virtual rather than the real or spatial domain’ (Yamin and Sinkovics 2006: 340). The literature on online or Internet internationalisation has usually assumed that the ‘active’ party is the firm as seller or vendor. The possibility of consumers actively using the Internet to find and transact with vendors located in foreign markets has not been extensively studied except in a few cases (e.g., Hadjikhani et al. 2011; Safari 2012). However this is an interesting and important phenomenon that merits careful study. It is interesting because it is a phenomenon that could not exist prior to the establishment and routine access to the Internet as a search and transaction medium, and it is important because this phenomenon has the potential to change the development of the global economy. Through its website, a retailer potentially has access to the whole world as prospective customers. This notion means that small firms have the potential to transform into large multinational firms. However, most customers still make their online purchases from domestic online retailers based on the notion that foreign online purchasing is risky and complicated. This raises important issues that need to be explored in order to understand consumer risk perception in this context. New theoretical tools are needed for this purpose.
|
|
| 38. |
|
|
| 39. |
- Safari, Abdolreza, et al.
(författare)
-
Determining the Gravitational Gradient Tensor Using Satellite Altimetry Observations over the Persian Gulf
- 2014
-
Ingår i: Marine Geodesy. - : Informa UK Limited. - 0149-0419 .- 1521-060X. ; 37:4, s. 404-418
-
Tidskriftsartikel (refereegranskat)abstract
- With the advent of satellite altimetry in 1973, new scientific applications became available in oceanography, climatology, and marine geosciences. Moreover, satellite altimetry provides a significant source of information facilitated in the geoid determination with a high accuracy and spatial resolution. The information from this approach is a sufficient alternate for marine gravity data in the high-frequency modeling of the marine gravity field quantities. The gravity gradient tensor, consisting of the second-order partial derivatives of the gravity potential, provides more localized information than gravity measurements. Marine gravity observations always carry a high noise level due to environmental effects. Moreover, it is not possible to model the high frequencies of the Earth's gravity field in a global scale using these observations. In this article, we introduce a novel approach for a determination of the gravity gradient tensor at sea level using satellite altimetry. Two numerical techniques are applied and compared for this purpose. In particular, we facilitate the radial basis functions (RBFs) and the harmonic splines. As a case study, the gravitational gradient tensor is determined and results presented in the Persian Gulf. Validation of results reveals that the solution of the harmonic spline approach has a better agreement with a theoretical zero-value of the trace of the Marussi gravitational gradient tensor. However, the data-adaptive technique in the RBF approach allows more efficient selection of the parameters and 3-D configuration of RBFs compared to a fixed parameterization by the harmonic splines.
|
|
| 40. |
|
|
| 41. |
- Safari Tirtashi, Mohammad Reza
(författare)
-
Control of Voltage and Damping in Bulk Power Systems
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modern power system is a complex dynamical system and one of the largest man-made systems. With recent driving forces like environmental concerns over air emissions, the modern power system is evolving towards an even more complex system. So it is necessary to handle the current challenges in power systems with simple approaches and avoid adding further complexity as much as possible. Also the implementation issues should be taken into account to meet the Transmission System Operators’ (TSOs’) interests. The considered problems in this thesis are related to voltage control and damping control which are two important issues challenging secure power system operation. The first voltage control problem addressed in the thesis occurred during the restoration of the Swedish power system after the blackout in 2003 and is called reactor hunting. Large scale voltage fluctuations are the consequence of the reactor hunting. The common practice used by the Swedish TSO to handle the reactor hunting is to turn off voltage control automatics during the restoration period. That leaves the shunt reactors in manual operation which leads to a longer restoration process. To prevent reactor hunting, an adaptive tolerance band strategy is proposed in the thesis together with two ways to implement it. One is model based and uses short circuit capacity of buses which are going to be energized during the restoration. The short circuit capacity associated to each bus is normally available in the Energy Management System (EMS) in the TSO control center. The second implementation can be completely local and independent of a model. By implementing this strategy, the automatic operation of the reactive shunts will continue during the restoration time, and reactor hunting is eliminated. This should shorten the restoration process. The second voltage control issue addressed in the thesis is related to control of shunt capacitors. Shunt capacitors are commonly controlled using a local scheme, which switches in the capacitor when the voltage at the locally monitored bus is outside a tolerance band. In some cases a shunt capacitor remains unused in a region lacking reactive power just because the local voltage is within the tolerance band. An alternative control strategy proposed in the thesis is called the neighboring scheme. It uses both the local voltage and the voltage at neighboring buses. The neighboring bus voltage is estimated from measurements at the local bus, so this strategy can be implemented locally and communication free which is important for TSOs. In a situation near voltage collapse, this strategy has better performance in the sense of improving the voltage control by connecting more shunt capacitors or connecting them earlier compared to the local scheme. For some scenarios, the voltage collapse that occurs using the local scheme is avoided when using the neighboring scheme. The second actuator used in the thesis for voltage control improvement is VSC-HVDC converters which have the capability to control active and reactive power independently. For emergency voltage control this thesis suggests adjusting active and reactive power set-points to change the AC system power flow. Based on the considered strategy, the active and reactive power set-points are adjusted depending on the disturbance. This control strategy improves the AC system long-term voltage stability and could prevent voltage collapse in some severe scenarios. When designing voltage control systems, the lack of a simple text book size version of NORDIC32 test system for long-term voltage stability study is another issue addressed in the thesis. The NORDIC32 test system is a reduced order model of the Swedish power system but in some cases still a complex test system. In this thesis, we propose the N3area test system which is a text book size version of NORDIC32 with minimum model complexity for our purposes. Applying complex control algorithms to the N3area system and analyzing them is much easier than to the NORDIC32 system. Still it retains a dynamic behaviour quite close to NORDIC32 and reality. The last problem addressed in the thesis is related to inter-area oscillations damping in power systems. These oscillations are becoming a big concern for TSOs since the power systems are getting more and more interconnected. Inter-area oscillations are often limiting the transfer capacity of transmission lines and may even lead to system break up as in the 1996 western North America blackout. Active power modulation is an effective solution to damp out such oscillations. This can be implemented by active power modulation at two points in the network, using for example VSC-HVDC links. Also single-point active power modulation using actuators like Energy Storage (ES) works well. Single-point reactive power modulation using actuators like SVC indirectly controls the active power and is also efficient. Proportional control of active power with local frequency as input is used in reality today for HVDC links. This type of damping controller can be applied for the ES and can also be translated for SVC damping controller. Implementing such proportional damping controllers is simple as they use local feedback signals. However, the damping of the inter-area mode is limited due to nearby zeros, which is evident in the associated root locus plot. It is therefore important to use the optimum gain to achieve the maximum possible damping. Gain selection is normally done using visual inspection of the root locus or through optimization. In this thesis, we propose the impedance matching based gain selection for the VSC-HVDC, ES and SVC damping controllers. It gives a physically based criterion for the optimum gain selection to reach the maximum possible damping of the mode with the greatest mode observability and controllability which depends on the actuator location while not affecting negatively the other modes in the system. The proposed approach may be used as basis for a controller that is self-tuning which is an important feature since the power system operating points are changing a lot. Also it is simpler for implementation in reality compared to the root locus inspection or application of advanced optimization methods for gain selection.
|
|
| 42. |
- Safari Tirtashi, Mohammad Reza, et al.
(författare)
-
Control strategies for reactive shunts to improve long-term voltage stability
- 2013
-
Ingår i: Power Engineering Conference (UPEC), 2013 48th International Universities.
-
Konferensbidrag (refereegranskat)abstract
- Voltage collapse was one of the main causes for many recent blackouts. The direct link between voltage stability and reactive power balance in the system leads to more attention toward reactive power resources in the power systems. Shunt reactors and capacitors are used to balance reactive power in the power systems. The strategy to control them in both normal and emergency conditions is an important issue. This paper deals with two different strategies for automatic switching of shunt reactors and capacitors in the power systems. The first control strategy, called the local scheme, switches the shunt when the voltage at the local bus is outside the tolerance band. In the second control strategy, called neighboring scheme, local voltage as well as voltage at neighboring buses are used. Dynamic simulations of the NORDIC 32 test system show that the neighboring scheme improves voltage compared to the local one. In the simulated scenario a blackout is avoided by using the neighboring scheme. This is explained using PV curves for a new test system reflecting the key behavior of NORDIC 32.
|
|
| 43. |
- Safari Tirtashi, Mohammad Reza, et al.
(författare)
-
Impedance Matching for VSC-HVDC and Energy Storage Damping Controllers
- 2018
-
Ingår i: IEEE Transactions on Power Delivery. - 0885-8977. ; 33:2, s. 1016-1017
-
Tidskriftsartikel (refereegranskat)abstract
- The small-disturbance electro-mechanical dynamics of a power system can be translated to an equivalent circuit model with inductances and capacitances. Damping control of active power in proportion to local frequency as with a VSC-HVDC link or an energy storage then corresponds to introducing a resistor in the circuit model. This letter shows that impedance matching can be used to select resistor value, and equivalently damping controller gain, that gives maximum damping ratio. It is also shown how the concept is employed without a circuit model.
|
|
| 44. |
- Safari Tirtashi, Mohammad Reza, et al.
(författare)
-
Long-Term Voltage Collapse Analysis on a Reduced Order Nordic System Model
- 2014
-
Ingår i: 2014 49th International Universities Power Engineering Conference (UPEC). - 9781479965564 ; , s. 1-6
-
Konferensbidrag (refereegranskat)abstract
- This paper analyzes and explains the mechanism behind long-term voltage collapse in the NORDIC32 test system. For this purpose a simplified test system called N5area, reflecting the key voltage collapse characteristics of NORDIC32 is proposed. Applying control algorithms is much easier in N5area than in NORDIC32. Load recovery and generator excitation current limiter actions which are two important factors contributing to long-term voltage collapse are considered. Dynamic simulation results for a specified long-term voltage instability scenario are explained and discussed. The effect of generator current limiters is analyzed using PV curves. Furthermore, two different control strategies for controlling the shunt capacitors are applied as countermeasures to save the system. The two strategies are explained and compared and it is shown that control using the voltage at neighboring buses gives better performance.
|
|
| 45. |
- Safaric, Luka, 1988-, et al.
(författare)
-
A Comparative Study of Biogas Reactor Fluid Rheology : Implications for Mixing Profile and Power Demand
- 2019
-
Ingår i: Processes. - Basel, Switzerland : MDPI. - 2227-9717. ; 7:10
-
Tidskriftsartikel (refereegranskat)abstract
- Anaerobic digestion (AD) is an established process for integrating waste management with renewable energy and nutrient recovery. Much of the research in this field focuses on the utilisation of new substrates, yet their effects on operational aspects such as fluid behaviour and power requirement for mixing are commonly overlooked, despite their importance for process optimisation. This study analysed rheological characteristics of samples from 21 laboratory-scale continuous stirred-tank biogas reactors (CSTBRs) digesting a range of substrates, in order to evaluate substrate effect on mixing efficiency and power demand through computational fluid dynamics (CFD). The results show that substrate and process parameters, such as solids content and organic loading, all have a significant effect on CSTBR fluid rheology. The correlation levels between rheological and process parameters were different across substrates, while no specific fluid behaviour patterns could be associated with substrate choice. Substrate should thus be considered an equally important rheology effector as process parameters. Additional substrate-related parameters should be identified to explain the differences in correlations between rheological and process parameters across substrate groups. The CFD modelling revealed that the rheology differences among the AD processes have significant implications for mixing efficiency and power demand of the CSTBRs, highlighting the importance of considering the substrate-induced effects on CSTBR rheology before including a new substrate.
|
|
| 46. |
|
|
| 47. |
- Bravo, L, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
| 48. |
- Tabiri, S, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
